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Journal articles on the topic 'Spiked body'

Author: Grafiati

Published: 6 September 2023

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1

Kalimuthu, R., R. C. Mehta, and E. Rathakrishnan. "Investigation of aerodynamic coefficients at Mach 6 over conical, hemispherical and flat-face spiked body." Aeronautical Journal 121, no. 1245 (October 2, 2017): 1711–32. http://dx.doi.org/10.1017/aer.2017.100.

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ABSTRACTA forward spike attached to a blunt body significantly alters its flow field characteristics and influences aerodynamic characteristics at hypersonic flow due to formation of separated flow and re-circulation region around the spiked body. An experimental investigation was performed to measure aerodynamic forces for spikes blunt bodies with a conical, hemispherical and flat-face spike at Mach 6 and at an angle-of-attack range from 0° to 8° and length-to-diameterL/Dratio of spike varies from 0.5 to 2.0, whereLis the length of the spike andDis diameter of blunt body. The shape of the leading edge of the spiked blunt body reveals different types of flow field features in the formation of a shock wave, shear layer, flow separation, re-circulation region and re-attachment shock. They are analysed with the help of schlieren pictures. The shock distance ahead of the hemisphere and the flat-face spike is compared with the analytical solution and is showing satisfactory agreement with the schlieren pictures. The influence of geometrical parameters of the spike, the shape of the spike tip and angle-of-attack on the aerodynamic coefficients are investigated by measuring aerodynamic forces in a hypersonic wind tunnel. It is found that a maximum reduction of drag of about 77% was found for hemisphere spike ofL/D= 2.0 at zero angle-of-attack. Consideration for compensation of increased pitching moment is required to stabilise the aerodynamic forces.

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2

Khurana, Shashank, Kojiro Suzuki, and Ethirajan Rathakrishnan. "Flow field behavior with Reynolds number variance around a spiked body." Modern Physics Letters B 30, no. 30 (November 7, 2016): 1650362. http://dx.doi.org/10.1142/s0217984916503620.

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An experimental visualization study was performed to investigate the dependence of the pressure hill height and the influence zone expanse, for flow past a spiked body with different nose configurations, over a Reynolds number range from 2278 to 4405 to establish the vortex shedding process, and applicability in low speed flow regime for effective pressure reduction. It is found that the spike reduces the radius of curvature of the approaching streamline, leading to the deflection of the streamlines towards the shoulder of the basic body, resulting in a narrow zone of the positive pressure hill at the body nose. It is also observed that the pressure hill length and the influence zone expanse decrease with the introduction of spike over the present range of Reynolds numbers. For Reynolds numbers less than 2700, spike with conical nose is found to be more efficient than the spikes with other nose shapes of the present study in reducing the positive pressure at the nose of the blunt body. For higher Reynolds numbers, greater than 2700, the size of the vortex at the junction of the spike and basic body is the largest for the spike with hemispherical nose, and emerges as a potential candidate for application in possible wind-design resistant structures.

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3

d’Humières, G., and J. L. Stollery. "Drag reduction on a spiked body at hypersonic speed." Aeronautical Journal 114, no. 1152 (February 2010): 113–19. http://dx.doi.org/10.1017/s0001924000003584.

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AbstractFitting a spike on a blunt body provides a drag reduction at supersonic and hypersonic speeds. In this study, the laminar flow over a spiked, conical body terminated by a spherical cap, inspired by the Apollo re-entry capsule design, was investigated using a hypersonic wind tunnel. Schlieren pictures revealed the absence of flow unsteadiness for the range of spike lengths tested, and force measurements showed a maximum reduction of 77% of the unspiked body drag.A simple theoretical model based on the pressure drag generated by a solid cone showed good agreement with the experimental data. The measured shock stand-off distance agreed well with predictions.

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4

Han, Guilai, and Zonglin Jiang. "Hypersonic Flow Field Reconfiguration and Drag Reduction of Blunt Body with Spikes and Sideward Jets." International Journal of Aerospace Engineering 2018 (2018): 1–16. http://dx.doi.org/10.1155/2018/7432961.

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Flow field reconfiguration and drag reduction have been investigated by numerically solving Navier-Stokes equations, with the 2nd order dispersion controlled dissipative scheme adopted for the convective term discretion and the 2nd order central difference scheme for viscous term. Spikes and sideward jets nearby the spike noses were set up in the front of the blunt body to reconfigure the flow field and reduce drag during hypersonic flight. The spikes and the sideward jets led to the formation of the conical shock, the reattached shock, and the circumfluence, instead of a bow shock. According to the quantitative analysis, the reconfiguration of the flow field played a dominant role in drag reduction. Basing on the locations of the reattached shock and its interaction with the conical shock, a combined parameter was proposed for a primary criterion to design the spiked bodies with sideward jets for the purpose of drag reduction.

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5

Feszty, D., K. J. Badcock, and B. E. Richards. "Utilising CFD in the investigation of high-speed unsteady spiked body flows." Aeronautical Journal 106, no. 1058 (April 2002): 161–74. http://dx.doi.org/10.1017/s0001924000012963.

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AbstractUnsteady spiked body flows were simulated by a second order time-accurate CFD method. Laminar, axisymmetric flow was considered at Mach 2.21 and Mach 6 freestreams and Reynolds’ numbers based on the blunt body diameter of 0.12 million and 0.13 million, respectively. A spiked forward facing cylinder with spike lengths between LID = 1.00 and LID = 2.40 was used as the model geometry. Following the numerical method’s verification, the individual flow modes of oscillation and pulsation were examined. The frequency of the events was found in good agreement with the experiment, while the pressure amplitudes were overpredicted in the Mach 6 cases. Analysis of the numerical results showed that the oscillation flow mode was driven by a viscous mechanism, whereas the pulsation by an inviscid one. The hysteresis phenomenon in the transition between the two flow modes was predicted qualitatively.

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6

Fan, Bing, and Jie Huang. "Coupled Fluid-Thermal Investigation on Drag and Heat Reduction of a Hypersonic Spiked Blunt Body with an Aerodisk." Aerospace 9, no. 1 (December 30, 2021): 19. http://dx.doi.org/10.3390/aerospace9010019.

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In the traditional investigations on the drag and heat reduction of hypersonic spiked models, only the aerodynamic calculation is performed, and the structural temperature cannot be obtained. This paper adopted the loosely coupled method to study its efficiency of drag and heat reduction, in which the feedback effect of wall temperature rise on aeroheating is considered. The aeroheating and structural temperature were obtained by the CFD and ABAQUS software respectively. The coupling analysis of the hypersonic circular tube was carried out to verify the accuracy of the fluid field, the structural temperature, and the coupled method. Compared with experimental results, the calculated results showed that the relative errors of stagnation heat flux and stagnation temperature were 1.34% and 4.95% respectively, and thus the effectiveness of the coupled method was verified. Installing a spike reduced the total drag of the forebody. The spiked model with an aerodisk reduced the aeroheating of the forebody, while the model without an aerodisk intensified the aeroheating. The spiked model with a planar aerodisk had the best performance on drag and heat reduction among all the models. In addition, increasing the length of the spike reduced the drag and temperature of the forebody. With the increase of the length, the change rates of drag, pressure, heat flux, and temperature decreased gradually. Increasing the diameter of the aerodisk also reduced the temperature of the forebody, while the efficiency of forebody drag reduction first increased and then decreased. In conclusion, the heat and drag reduction must be considered comprehensively for the optimal design of the spike.

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7

Wüstenberg, Daniel G., Milena Boytcheva, Bernd Grünewald, John H. Byrne, Randolf Menzel, and Douglas A. Baxter. "Current- and Voltage-Clamp Recordings and Computer Simulations of Kenyon Cells in the Honeybee." Journal of Neurophysiology 92, no. 4 (October 2004): 2589–603. http://dx.doi.org/10.1152/jn.01259.2003.

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The mushroom body of the insect brain is an important locus for olfactory information processing and associative learning. The present study investigated the biophysical properties of Kenyon cells, which form the mushroom body. Current- and voltage-clamp analyses were performed on cultured Kenyon cells from honeybees. Current-clamp analyses indicated that Kenyon cells did not spike spontaneously in vitro. However, spikes could be elicited by current injection in approximately 85% of the cells. Of the cells that produced spikes during a 1-s depolarizing current pulse, approximately 60% exhibited repetitive spiking, whereas the remaining approximately 40% fired a single spike. Cells that spiked repetitively showed little frequency adaptation. However, spikes consistently became broader and smaller during repetitive activity. Voltage-clamp analyses characterized a fast transient Na+ current ( INa), a delayed rectifier K+ current ( IK,V), and a fast transient K+ current ( IK,A). Using the neurosimulator SNNAP, a Hodgkin–Huxley-type model was developed and used to investigate the roles of the different currents during spiking. The model led to the prediction of a slow transient outward current ( IK,ST) that was subsequently identified by reevaluating the voltage-clamp data. Simulations indicated that the primary currents that underlie spiking are INa and IK,V, whereas IK,A and IK,ST primarily determined the responsiveness of the model to stimuli such as constant or oscillatory injections of current.

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8

Kalimuthu, R., R. C. Mehta, and E. Rathakrishnan. "Experimental investigation on spiked body in hypersonic flow." Aeronautical Journal 112, no. 1136 (October 2008): 593–98. http://dx.doi.org/10.1017/s0001924000002554.

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Abstract A spike attached to a hemispherical body drastically changes its flowfield and influences aerodynamic drag in a hypersonic flow. It is, therefore, a potential candidate for drag reduction of a future high-speed vehicle. The effect of the spike length, shape, spike nose configuration and angle-of-attack on the reduction of the drag is experimentally studied with use of hypersonic wind-tunnel at Mach 6. The effects of geometrical parameters of the spike and angle-of-attack on the aerodynamic coefficient are analysed using schlieren picture and measuring aerodynamic forces. These experiments show that the aerodisk is superior to the aerospike. The aerodisk of appropriate length, diameter and nose configuration may have the capability for the drag reduction. The inclusion of an aero disk at the leading edge of the spike has an advantage for the drag reduction mechanism if it is at an angle-of-attack, however consideration to be given for increased moment resulting from the spike is required.

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9

Mansour, Kamyar, and Mahdi Khorsandi. "The drag reduction in spherical spiked blunt body." Acta Astronautica 99 (June 2014): 92–98. http://dx.doi.org/10.1016/j.actaastro.2014.02.009.

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10

Ahmed, M. Y. M., and N. Qin. "Numerical investigation of aeroheating characteristics of spiked blunt bodies at Mach six flight conditions." Aeronautical Journal 115, no. 1168 (June 2011): 377–86. http://dx.doi.org/10.1017/s0001924000005893.

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AbstractAdding a small aerodisk at the tip of the spike was proved to improve the spike’s performance in reducing the drag. If designed properly, the aerodisk spike can offer better performance in drag reduction in comparison with the pointed sharp-nosed spike. However, the impact of the aerodisk on the aeroheating reduction capabilities of the spike was not investigated in detail before. In the present work, a numerical investigation of the aerothermodynamic characteristics of spiked blunt bodies at Mach 6 flight conditions is conducted. It was found that, adding an aerodisk degrades the performance of the spike in reducing the aeroheating level. Nonetheless, the latter remains below that of the unspiked body.

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11

PANARAS, ARGYRIS G., and DIMITRIS DRIKAKIS. "High-speed unsteady flows around spiked-blunt bodies." Journal of Fluid Mechanics 632 (July 27, 2009): 69–96. http://dx.doi.org/10.1017/s0022112009006235.

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This paper presents a detailed investigation of unsteady supersonic and hypersonic flows around spiked-blunt bodies, including the investigation of the effects of the flow field initialization on the flow results. Past experimental research has shown that if the geometry of a spiked-blunt body is such that a shock formation consisting of an oblique foreshock and a bow aftershock appears, then the flow may be unsteady. The unsteady flow is characterized by periodic radial inflation and collapse of the conical separation bubble formed around the spike (pulsation). Beyond a certain spike length the flow is ‘stable’, i.e. steady or mildly oscillating in the radial direction. Both unsteady and ‘stable’ conditions have been reported when increasing or decreasing the spike length during an experimental test and, additionally, hysteresis effects have been observed. The present study reveals that for certain geometries the numerically simulated flow depends strongly on the assumed initial flow field, including the occurrence of bifurcations due to inherent hysteresis effects and the appearance of unsteady flow modes. Computations using several different configurations reveal that the transient (initial) flow development corresponds to a nearly inviscid flow field characterized by a foreshock–aftershock interaction. When the flow is pulsating, the further flow development is not sensitive to initial conditions, whereas for an oscillating or almost ‘steady’ flow, the flow development depends strongly on the assumed initial flow field.

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12

Tembhurnikar, Payal, Akash Jadhav, and Devabrata Sahoo. "Effect of intermediate aerodisk mounted sharp tip spike on the drag reduction over a hemispherical body at Mach 2.0." FME Transactions 48, no. 4 (2020): 779–86. http://dx.doi.org/10.5937/fme2004779t.

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Reduction of forebody drag in high speed flying vehicles such as rockets and missiles are of high research interest in the present time. In the present research, drag reduction obtained by using an intermediate aerodisk mounted sharp tip spike has been investigated using computational studies at Mach number of 2.0. The flowfield over a hemispherical blunt body with an intermediate aerodisk mounted sharp tip spike is investigated at zero degree angle of attack and the amount of drag reduction obtained is then compared with that of a conventional sharp tip spike mounted hemisphere. The presence of an intermediate aerodisk changes the flow physics and shock system over the blunt body. The change in the system of shock waves by mounting an intermediate aerodisk results in a higher percentage (20% higher) of drag reduction generated by the blunt spiked body moving at a supersonic speed of Mach 2.0. Use of intermediate aerodisk proves to be beneficial in terms of drag reduction for spike lengths ranging beyond the critical length.

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13

Latha, V., and P. Basha. "Extent of Heavy Metal Accumulation in Sewage Irrigated Soils and Their Impact on Distribution of Earthworm Communities: Linking Chromium and Zinc Toxicity on Growth and Reproduction in Selected Earthworm Species." Current World Environment 11, no. 1 (April 25, 2016): 279–90. http://dx.doi.org/10.12944/cwe.11.1.34.

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Soil ecosystem polluted by metals affect the structure of soil invertebrate population(s) and dynamics leading to altered distribution of species. This study focuses on earthworm distribution in sewage irrigated agricultural lands around Bangalore. The occurrence of reported species from the sampled areas is Eudrilus eugeniae, Lampito maurutii, Pontoscolex corethrurus, Polypheretima elongata, Perioynx excavates and Eisenia fetida. Laboratory studies conducted to evaluate feed ingestion rate and body mass changes in earthworms exposed to metal spiked soils revealed species specific pattern. Eudrilus eugeniae and Lampito maurutii showed a steep increase in body weight, while Pontoscolex corethrurus exhibited decreased trend upon Zn exposure. Contrarily a significant (p<0.05) decline in body weight was evident in all the three species upon exposure to Cr spiked soils. The observed alterations in feeding and body mass index concomitantly influenced the reproductive parameters. Rate of hatchability and reproductive function found to be decreased in Cr spiked soils in all the three species studied. Contrarily, increased hatchability was observed in E.eugeniea and L.maurutii followed by a decrease rate in P.corethrurus upon exposure of Zn spiked soils. However, reproductive rate found to be increased in E.eugeniea and P.corethrurus with decreased trend in L.maurutii. Thus, use of sewage polluted water for irrigation purpose has led to increased soil metal concentration impacting earthworm physiology and distribution.

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14

Borgmann, U., and W. P. Norwood. "Toxicity and accumulation of zinc and copper in Hyalella azteca exposed to metal-spiked sediments." Canadian Journal of Fisheries and Aquatic Sciences 54, no. 5 (May 1, 1997): 1046–54. http://dx.doi.org/10.1139/f97-020.

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The relationship between zinc and copper toxicity in Hyalella azteca and accumulation from metal-spiked sediments was determined for future use in identifying sites where these metals contribute to sediment toxicity. Both zinc and copper accumulation increased rapidly with increasing sediment concentrations, showing no evidence of saturation as seen in waterborne exposures. Zinc accumulation from zinc spiked sediments was substantial, even at concentrations below those causing chronic toxicity, and body concentrations can readily be used to infer chronic toxicity. Chronic toxicity in spiked sediment exposures occurred at excess (above background) body concentrations twice as high as in waterborne exposures, possibly as a result of zinc in gut contents. In contrast, chronic copper toxicity occurred at body concentrations lower than those observed in waterborne exposures. Furthermore, body copper at low sediment exposures was independent of copper in sediment. Body copper concentrations can be used to infer short-term (1-week) toxicity but not chronic toxicity. Copper, but not zinc, caused a reduction in growth, even at concentrations below the 4-week LC25. Reduced growth can, therefore, be used to differentiate between chronic copper and zinc toxicity in sediments.

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15

Kumar, Shailendra, and Vinayak Kulkarni. "Drag of a Spiked Body in Chemically Reacting Hypersonic Flow." Journal of Spacecraft and Rockets 57, no. 5 (September 2020): 1092–97. http://dx.doi.org/10.2514/1.a34764.

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16

Yamauchi, Masafumi, Kozo Fujii, and Fumio Higashino. "Numerical investigation of supersonic flows around a spiked blunt body." Journal of Spacecraft and Rockets 32, no. 1 (January 1995): 32–42. http://dx.doi.org/10.2514/3.26571.

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17

Kobayashi, Hiroaki, Katsuyoshi Fukiba, Motoyuki Hongoh, Tetsuya Sato, and Kazuhide Mizobata. "Experimental Study on Aerodynamic Characteristics Control of a Spiked Body." JOURNAL OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES 55, no. 644 (2007): 418–25. http://dx.doi.org/10.2322/jjsass.55.418.

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18

Nazarov, S. A. "The spectrum of the elasticity problem for a spiked body." Siberian Mathematical Journal 49, no. 5 (September 2008): 874–93. http://dx.doi.org/10.1007/s11202-008-0087-8.

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19

Yadav, R., A. Bodavula, and S. Joshi. "Numerical investigation of the effect of disk position on the aerodynamic heating and drag of a spiked blunt body in hypersonic flow." Aeronautical Journal 122, no. 1258 (September 18, 2018): 1916–42. http://dx.doi.org/10.1017/aer.2018.109.

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ABSTRACTDetailed numerical simulations have been carried out on a spiked blunt body with multiple hemispherical disks using a commercial CFD code in order to investigate their effectiveness in reducing the aerodynamic drag and heating. The base configuration is a hemispherical cylinder whose diameter is 40 mm with an overall length of 70 mm. The lengths of the aerospikes investigated are 1, 1.5, 2 and 2.5 times the base diameter of the cylinder and the radii of the aerodisks are varied between 0.05, 0.1, 0.15 and 0.2 times the diameter of the cylinder. Besides these, the position of the aerodisks is varied with the rearmost aerodisk placed at 25%, 50% and 75% along the length of the aerospike and the intermediate aerodisk for three-disk cases, positioned at 25%, 50% and 75% of the distance between the front and the rearmost disk. All the investigations have carried out at a freestream Mach number of 6.2 and Reynolds number of 2.64 × 107/m. It has been observed that the multidisk spikes are advantageous for the purpose of reduction of both aerodynamic drag and heating at hypersonic speed. The two aerodisk spiked configurations show better results in terms of aerodynamic heating and drag in comparison to the single-disk aerospikes while the three-disk spikes yield only a marginal reduction in aerodynamic drag over the two-disk configurations. For reduction of heat fluxes and heat transfer rates though, the three-disk configurations are extremely advantageous and give much larger reductions are compared to the two-disk configurations.

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20

Ma, Yu, Xiaowei Liu, and Ping Ou. "Numerical Investigation of Hypersonic Unsteady Flow Around a Spiked Blunt-body." Procedia Engineering 126 (2015): 163–68. http://dx.doi.org/10.1016/j.proeng.2015.11.204.

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21

Qin, Qihao, Jinglei Xu, and Shuai Guo. "Fluid-thermal analysis of aerodynamic heating over spiked blunt body configurations." Acta Astronautica 132 (March 2017): 230–42. http://dx.doi.org/10.1016/j.actaastro.2016.12.037.

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22

Huang, Jie, and Weixing Yao. "Multi-Objective Design Optimization of Hypersonic Spiked Blunt Body with Opposing Jet." Journal of Spacecraft and Rockets 56, no. 5 (September 2019): 1553–63. http://dx.doi.org/10.2514/1.a34459.

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23

Sahoo, Devabrata, S. K. Karthick, Sudip Das, and Jacob Cohen. "Parametric Experimental Studies on Supersonic Flow Unsteadiness over a Hemispherical Spiked Body." AIAA Journal 58, no. 8 (August 2020): 3446–63. http://dx.doi.org/10.2514/1.j059369.

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24

Mehta, R. C. "Heat transfer study of high speed flow over a spiked blunt body." International Journal of Numerical Methods for Heat & Fluid Flow 10, no. 7 (November 2000): 750–69. http://dx.doi.org/10.1108/09615530010347204.

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25

Mehta, R. C. "Peak heating for reattachment of separated flow on a spiked blunt-body." Heat and Mass Transfer 36, no. 4 (July 27, 2000): 277–83. http://dx.doi.org/10.1007/s002310000091.

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26

Uklejewski, Ryszard, Mariusz Winiecki, Piotr Krawczyk, and Renata Tokłowicz. "Native Osseous CaP Biomineral Coating on a Biomimetic Multi-Spiked Connecting Scaffold Prototype for Cementless Resurfacing Arthroplasty Achieved by Combined Electrochemical Deposition." Materials 12, no. 23 (December 2, 2019): 3994. http://dx.doi.org/10.3390/ma12233994.

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The multi-spiked connecting scaffold (MSC-Scaffold) prototype with spikes mimicking the interdigitations of articular subchondral bone is an essential innovation in surgically initiated fixation of resurfacing arthroplasty (RA) endoprosthesis components. This paper aimed to present a determination of the suitable range of conditions for the calcium phosphate (CaP) potentiostatic electrochemical deposition (ECDV=const) on the MSC-Scaffold prototype spikes to achieve a biomineral coating with a native Ca/P ratio. The CaP ECDV=const process on the MSC-Scaffold Ti4Al6V pre-prototypes was investigated for potential VECDfrom −9 to −3 V, and followed by 48 h immersion in a simulated body fluid. An acid–alkaline pretreatment (AAT) was applied for a portion of the pre-prototypes. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) studies of deposited coatings together with coatings weight measurements were performed. Themost suitable VECD range, from −5.25 to −4.75 V, was determined as the native biomineral Ca/P ratio of coatings was achieved. AAT increases the weight of deposited coatings (44% for VECD = −5.25 V, 9% for VECD = −5.00 V and 15% for VECD = −4.75 V) and the coverage degree of the lateral spike surfaces (40% for VECD = −5.25 V, 14% for VECD = −5.00 V and 100% for VECD = −4.75 V). XRD confirmed that the multiphasic CaP coating containing crystalline octacalcium phosphate is produced on the lateral surface of the spikes of the MSC-Scaffold. ECDV=const preceded by AAT prevents micro-cracks on the bone-contacting surfaces of the MSC-Scaffold prototype, increases its spikes’ lateral surface coverage, and results in the best modification effect at VECD = −5.00 V. To conclude, the biomimetic MSC-Scaffold prototype with desired biomineral coating of native Ca/P ratio was obtained for cementless RA endoprostheses.

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27

Wang, Hongyu, Yanguang Yang, Langquan Li, Gang Wang, and Qinghu Zhang. "Effects of Heat Addition on Wave Drag Reduction of a Spiked Blunt Body." International Journal of Aerospace Engineering 2021 (January 16, 2021): 1–10. http://dx.doi.org/10.1155/2021/8872812.

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Drag reduction technology plays a significant role in extending the flight range for a high-speed vehicle. A wave drag reduction strategy via heat addition to a blunt body with a spike was proposed and numerically validated. The heat addition is simulated with continuous heating in a confined area upstream of the blunt body. The effects of heat addition on drag reduction in three flow conditions ( M = 3.98 , 5 , 6 ) were compared, and the influence of power density q h ( q 1 = 2.0 × 10 8 W / m 3 , q 2 = 5.0 × 10 8 W / m 3 , and q 3 = 1.0 × 10 9 W / m 3 ) of heating was evaluated. Results show that the heat addition has a positive way to reduce the drag of the body with a spike alone, and more satisfactory drag reduction effectiveness can be achieved at a higher Mach number. The drag reduction coefficient increases with q h in the same flow condition, with a maximum of 38.9% ( M = 6 ) as q 3 = 1.0 × 10 9 W / m 3 . The wave drag reduction principle was discussed by a transient calculation, which indicates that the separation region has entrainment of the heated air and expanded with its sonic line away from the blunt cone, which results in an alleviation of the pressure load caused by shock/shock interaction.

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28

Feszty, Daniel, Ken J. Badcock, and Bryan E. Richards. "Driving Mechanisms of High-Speed Unsteady Spiked Body Flows, Part I: Pulsation Mode." AIAA Journal 42, no. 1 (January 2004): 95–106. http://dx.doi.org/10.2514/1.9034.

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29

Feszty, Daniel, Ken J. Badcock, and Bryan E. Richards. "Driving Mechanism of High-Speed Unsteady Spiked Body Flows, Part 2: Oscillation Mode." AIAA Journal 42, no. 1 (January 2004): 107–13. http://dx.doi.org/10.2514/1.9035.

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30

HIRAKI, Koju, Harald KLEINE, Hirotaka MARUYAMA, Kazuya KITAMURA, Tetsuya HAYASHIDA, and Jun YONAI. "S1904-2-4 Visualization of Unsteady Flow around Spiked Body in Supersonic Flow." Proceedings of the JSME annual meeting 2009.5 (2009): 301–2. http://dx.doi.org/10.1299/jsmemecjo.2009.5.0_301.

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31

Mehta, R. C. "Numerical heat transfer study around a spiked blunt-nose body at Mach 6." Heat and Mass Transfer 49, no. 4 (December 12, 2012): 485–96. http://dx.doi.org/10.1007/s00231-012-1095-6.

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32

Park, Eun-Kee, Won Jung, and Hu-Jang Lee. "Application of a solid-phase fluorescence immunoassay to determine amoxicillin residues in fish tissue." Acta Veterinaria Hungarica 58, no. 1 (March 1, 2010): 83–89. http://dx.doi.org/10.1556/avet.58.2010.1.9.

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The present study demonstrates an application of Parallux™ (a solid-phase fluorescence immunoassay) for amoxicillin analysis in fish tissue. Amoxicillin at the recommended therapeutic dose (400 mg/kg body weight) was orally administered to three groups of 25 olive flounder (Paralichthys olivaceus), 25 rockfish (Sebastes schlegeli) and 25 red sea bream (Pagrus major) for 7 consecutive days. Amoxicillin was detected in the muscle of fish treated by the 3rd day of the withdrawal period. The recovery rates of all spiked muscle samples were > 86% of the spiked values. The present study showed that solid-phase fluorescence immunoassay can be easily adopted in predicting amoxicillin residues in the muscle tissue of farmed fish.

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33

Howland, Julia, Alexa Alexander, Danielle Milani, Kerry Peru, and Joseph Culp. "Risks of Mixtures of Oil Sands Contaminants to a Sensitive Mayfly Sentinel, Hexagenia." Diversity 11, no. 8 (July 24, 2019): 118. http://dx.doi.org/10.3390/d11080118.

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Tailings ponds in northeastern Alberta, Canada contain massive amounts of oil sands process water (OSPW) that cannot currently be released due to the toxicity of some components. Limited space and the need for reclamation of oil sands operation sites will necessitate the release of OSPW in the near future. Knowledge of the composition and toxicity of OSPW is lacking yet is crucial for both risk assessment and management planning. This study examines chronic toxicity of a mixture of OSPW components sodium naphthenate and naphthenic acid (NA) to nymphs of the mayfly Hexagenia spp. in control and polycyclic aromatic hydrocarbons (PAH)-spiked sediment treatments. The objective of this study was to determine whether the addition of the PAH-spiked sediment significantly contributed to or masked responses of these sensitive mayflies to mixtures of NA. Mean survival in nymphs exposed to NA and PAH-spiked sediment treatments was reduced by 48% compared to those exposed to the NA mixture alone. Lethal responses were observed in all of the PAH-spiked sediment treatments. However, within PAH-spiked and control sediment treatments, there was no significant difference in nymph survival due to NA concentration, indicating that changes in survivorship were predominantly a reflection of increased mortality associated with sediment PAHs and not to the NA mixture treatment. Sublethal effects on body segment ratios suggest that mayflies exposed to NA and PAH-spiked sediment, as well as those exposed to the highest NA concentration tested (1 mg/L) and control sediment, made developmental trade-offs in order to emerge faster and escape a stressful environment. These results reveal that the release of OSPW to the surrounding environment could cause a reduction in mayfly populations. Mayflies provide ecosystem services and are an important food source for higher trophic levels in both the aquatic and terrestrial communities.

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Schelling, S. H., A. S. Tidwell, and R. J. Boudrieau. "Clinical, Radiographic and Histological Evaluation of the Plastic Spiked Washer in the Dog." Veterinary and Comparative Orthopaedics and Traumatology 11, no. 03 (1998): 125–30. http://dx.doi.org/10.1055/s-0038-1632533.

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SummaryPlastic spiked washers and metal washers were implanted in the periarticular soft tissues of six joints in three experimental dogs. These dogs were followed clinically and radiographically over a 16 week time frame, at which time they were euthanatized and histological evaluation was obtained. Differences were not observed clinically nor radiographically between joints, nor between locations, with the different implant devices throughout the time frame investigated in the experimental dogs. Histological evaluation revealed a very minimal to mild, fundamentally identical inflammatory response to all of the implants in all of the specimens; however, in three specimens (plastic spiked washers), very infrequent lesions of a few randomly scattered microgranulomas, surrounded by a fibrous connective tissue envelope, were observed. The histological response of a limited inflammatory reaction was comparable to the positive controls using metal washers in the experimental dogs, despite the few microgranulomas observed. A clinical retrospective evaluation of 31 joints in 29 dogs from 1992 to 1996, in which a plastic spiked washer was implanted, also was performed. Long term follow up (mean 2.6 years) of 21 dogs in the clinical case series revealed no complications related to infection or a foreign-body reaction. Both the experimental and clinical studies supported the authors’ impression that the plastic spiked washer is well tolerated over the long term.A 16 week experimental study was performed in three dogs (six joints) in order to evaluate if any clinical, radiographic or histological differences could be found in the periarticular soft tissues with implantation of either a plastic spiked washer or a metal washer. No differences were observed clinically or radiographically between joints, or between locations, with the different implants. Histological evaluation revealed a very minimal to mild inflammatory response to all of the implants; however, a few very infrequent and randomly scattered microgranulomas were observed in response to the plastic spiked washers.

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Sebastian, Jiss J., Sandeep Eldho James, and Abhilash Suryan. "Computational Study of Hypersonic Flow Past Spiked Blunt Body Using RANS and DSMC Method." Procedia Technology 25 (2016): 892–99. http://dx.doi.org/10.1016/j.protcy.2016.08.174.

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Mehta, R. C. "Numerical simulation of the flow field over conical, disc and flat spiked body at Mach 6." Aeronautical Journal 114, no. 1154 (April 2010): 225–36. http://dx.doi.org/10.1017/s0001924000003675.

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Abstract A forward facing spike attached to a hemispherical body significantly changes its flow field and influences aerodynamic drag and wall heat flux in a high speed flow. The dynamic pressure in the recirculation area is highly reduced and this leads to the decrease in the aerodynamic drag and heat load on the surface. Consequently, the geometry, that is, the length and shape of the spike, has to be simulated in order to obtain a large conical recirculation region in front of the blunt body to get beneficial drag reduction. It is, therefore, a potential candidate for aerodynamic drag reduction for a future high speed vehicle. Axisymmetric compressible laminar Navier-Stokes equations are solved using a finite volume discretisation in conjunction with a multistage Runge-Kutta time stepping scheme. The effect of the spike length and shape, and the spike nose configuration on the reduction of drag is numerically evaluated at Mach 6 at a zero angle-of-attack. The computed density contours agree well with the schlieren images. Additional modification to the tip of the spike to get different types of flow field such as the formation of a shock wave, separation area and reattachment point are examined. The spike geometries include the conical spike, the flat-disk spike and the hemispherical disk spike of different length to diameter ratios attached to the blunt body.

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Perera, Isabel M. "Mental health and politics since the eurozone crisis: The role of mental health professionals." European Psychiatry 62 (October 2019): 28–29. http://dx.doi.org/10.1016/j.eurpsy.2019.08.014.

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Abstract Some of the most immediate health effects of the 2008 economic crisis concerned the mind, not the body. Rates of generalized anxiety, chronic depression, and even suicide spiked in many European societies. This viewpoint highlights the role of mental health professionals in responding to this emergency, and argues that their sustained mobilization is necessary to its long-term resolution.

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Hamza, Muhammad, Saima Bukhat Khan, and Adnan Maqsood. "Geometric Optimization of Blunt Bodies with Aerodisk and Opposing Jet for Wave Drag and Heat Reduction." Aerospace 9, no. 12 (December 6, 2022): 800. http://dx.doi.org/10.3390/aerospace9120800.

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The use of passive, active, or hybrid flow control techniques is often investigated to reduce the acoustic signature, wave drag, and aerodynamic heating associated with the supersonic flow regime. This research explores passive and hybrid flow control techniques to achieve an optimal reduction in wave drag and aerodynamic heating on a blunt body using an aerodisk. While passive techniques use one or two aerospikes, hybrid techniques employ opposing jets and aerospikes. Numerical analysis is performed using Reynolds-Averaged Navier–Stokes (RANS) equations to analyze the bodies’ flow field. The statistical technique, Design of Experiments (DOE), is combined with Response Surface Method (RSM) to find the optimal configuration for four cases by generating design space. Two cases were considered for the optimization: single aerospike with and without opposing jet and double aerospike with and without opposing jet. Variables used for the design of the aerodisks were spike length and diameter, while the response variables were wave drag and normalized heat flux. The current study has established an optimum relationship between spike length and aerospike diameter located in front of the main blunt body for both single and double aerospikes. The study’s results suggest that a double aerodisk configuration is more beneficial for reducing drag and heat flux at supersonic speed than a single aerodisk. By incorporating an opposing jet at a pressure ratio of 0.8 from the frontal aerodisk to the spiked blunt body, it can reduce drag and heat flux by 86% and 95%, respectively. Finally, numerical verification is performed for statistically optimized designs.

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Narayana, Gopalakrishna, and Saravanan Selvaraj. "Attenuation of pulsation and oscillation using a disk at mid-section of spiked blunt body." Physics of Fluids 32, no. 11 (November 1, 2020): 116106. http://dx.doi.org/10.1063/5.0024649.

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Borgmann, Uwe, and Warren P. Norwood. "Assessing the toxicity of lead in sediments to Hyalella azteca: the significance of bioaccumulation and dissolved metal." Canadian Journal of Fisheries and Aquatic Sciences 56, no. 8 (August 1, 1999): 1494–503. http://dx.doi.org/10.1139/f99-073.

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The relationship between bioaccumulation and toxicity of Pb to Hyalella was the same for animals exposed to Pb in water alone and for those exposed to Pb-spiked sediments, provided that the animals were gut cleared before Pb analysis. The same critical body concentration (about 126 nmol·g dry mass-1) can be used to predict Pb toxicity in both water-only and sediment exposures. Furthermore, Pb bioavailability in Pb-spiked sediments was due primarily to dissolved metal: animals caged above the sediments accumulated the same amount of Pb and had the same mortality as animals exposed directly to sediment. Increasing the water to sediment ratio from 4:1 to 67:1 resulted in a lower dissolved organic C and lower total dissolved Pb concentration in the water but no change in bioavailable Pb (i.e., bioavailable Pb was not proportional to total dissolved Pb). The overlying water concentration may be a useful indicator of bioavailable Pb in sediment tests, provided a large water to sediment ratio is used to reduce the effect of sediment on overlying water quality (i.e., Pb-complexing capacity). Although less reliable than body concentration measurements, this could provide a useful screening tool for possible Pb-induced toxicity because it can be measured without test animals present.

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WANG, MUH-RONG, and YANG-SHENG HUANG. "DYNAMICS OF MIXING PROCESSES IN THE MICRO-MIXER WITH CURVED BLUFF-BODY STRUCTURE UNDER EXTERNAL EXCITATION." Modern Physics Letters B 23, no. 03 (January 30, 2009): 401–4. http://dx.doi.org/10.1142/s0217984909018503.

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This paper investigates the effects of external excitation on the mixing performance of the micromixer with curved bluff-body structure. The micromixer was fabricated by the MEMS process of polydimethylsiloxane (PDMS). The mixing process and mixing efficiency were evaluated with a high speed camera. Results showed that the finger-spiked type flow patterns were generated in the mixing chamber under an excitation frequency of 5Hz. It turns out that the mixing efficiency as high as 85.6% is achieved at Re =0.25 with a single bluff-body structure. It demonstrates that the new design can be used to achieve complete mixing within ultra short length at mciroscale.

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R. Lotufo, J. D. Farrar, B. M. Duke, G. "DDT Toxicity and Critical Body Residue in the Amphipod Leptocheirus plumulosus in Exposures to Spiked Sediment." Archives of Environmental Contamination and Toxicology 41, no. 2 (September 6, 2001): 142–50. http://dx.doi.org/10.1007/s002440010231.

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43

Huang, Jie, Wei-Xing Yao, and Ning Qin. "Heat reduction mechanism of hypersonic spiked blunt body with installation angle at large angle of attack." Acta Astronautica 164 (November 2019): 268–76. http://dx.doi.org/10.1016/j.actaastro.2019.07.003.

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Wang, Xingmin, Mengting Zhang, Huiyi Cao, Mudasir Irfan Dar, and Shaukat Ali. "Transfer of Copper (Cu) in the Soil–Plant–Mealybug–Ladybird Beetle Food Chain." Insects 13, no. 9 (August 24, 2022): 761. http://dx.doi.org/10.3390/insects13090761.

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Copper, an essential trace element, is vital for living organisms’ survival; however, despite its importance, an excessive amount of this micro-nutrient can cause harmful effects to plants and animals. The present study investigates Cu bio-transfer across multi-trophic food chain comprising soil (spiked with various concentrations of Cu), eggplant (Solanum melongena), mealybug (Ferrisia virgata), and ladybird (Nephus ryuguus). Soils were spiked with Cu at rates of 0, 100, 200, 400, and 800 mg/kg (w/w). A dose-dependent increase in the levels of Cu in plant, mealybug, and ladybird was observed in response to Cu contents of soil. Different Cu amendment caused a significant reduction in the average root and shoot dry weights per plant as well as the average body weights of F. virgata and N. ryuguus. Our findings affirmed the importance of additional research to explain the processes involved in the bio-transfer of copper across the food chain.

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Péry, Alexandre R. R., Anne Béthune, Josiane Gahou, Raphaël Mons, and Jeanne Garric. "Body residues: a key variable to analyze toxicity tests with Chironomus riparius exposed to copper-spiked sediments." Ecotoxicology and Environmental Safety 61, no. 2 (June 2005): 160–67. http://dx.doi.org/10.1016/j.ecoenv.2004.11.001.

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Guan, Ruiqing, Qihao Qin, Yifan Wang, and Jinglei Xu. "Experimental investigation of the pulsing flow field around four types of spiked-blunt body at Mach 2.2." Aerospace Science and Technology 133 (February 2023): 108129. http://dx.doi.org/10.1016/j.ast.2023.108129.

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47

Gulas-Wroblewski, Bonnie E., Rebecca B. Kairis, Rodion Gorchakov, Anna Wheless, and Kristy O. Murray. "Optimization of DNA Extraction from Field-Collected Mammalian Whole Blood on Filter Paper for Trypanosoma cruzi (Chagas Disease) Detection." Pathogens 10, no. 8 (August 17, 2021): 1040. http://dx.doi.org/10.3390/pathogens10081040.

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Blood filter paper strips are cost-effective materials used to store body fluid specimens under challenging field conditions, extending the reach of zoonotic pathogen surveillance and research. We describe an optimized procedure for the extraction of parasite DNA from whole blood (WB) stored on Type I Advantec Nobuto strips from both experimentally spiked and field-collected specimens from canine and skunks, respectively. When comparing two commercial kits for extraction, Qiagen’s DNeasy Blood & Tissue Kit performed best for the detection of parasite DNA by PCR from Trypanosoma cruzi-spiked canine WB samples on Nobuto strips. To further optimize recovery of β-actin from field-collected skunk WB archived on Nobuto strips, we modified the extraction procedures for the Qiagen kit with a 90 °C incubation step and extended incubation post-addition of proteinase K, a method subsequently employed to identify a T. cruzi infection in one of the skunks. Using this optimized extraction method can efficaciously increase the accuracy and precision of future molecular epidemiologic investigations targeting neglected tropical diseases in field-collected WB specimens on filter strips.

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Andronic, Octavian, Alin Dragomir, and Daniel Ion. "Foreign body at the level of rectal tumor formation." Medical Image Database 2, no. 1 (January 25, 2019): 1–2. http://dx.doi.org/10.33695/mid.v2i1.15.

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We present the case of a 75-year-old patient presenting with nausea, faecal emesis and intense abdominal meteorism, symptoms that began three before presentatiton and accentuated within the last 12 hours. Clinical examination revealed an incresead volume of the abdomen, painfully diffused on palpation. Abdominal radiography highlights multiple hydroaeric levels. Computerized tomography: Parietal, circumferential thickening with spiked contours of the middle sigmoid, associating the important distension of the overlying sigmoid, and, at the level of the stenosis, endoluminal, a linear image of 3mm thick and 24mm in length, spontaneous hyperdensity (180UH), important densification of neighboring fat. A rectosigmoidectomy with left flank colostomy – Hartmann’s operation, is performed. The opening of the lumen of the resected colonic portion reveals a foreign body (wooden fragment) impacted at this level. Histopathological diagnosis is colonic adenocarcinoma with a high degree of cellular differentiation (G1) invasively up to serum pT3N0. The particularity of the case consists in the difficulty of the pre- and intraoperative differential diagnosis between a neoplasia requiring an oncological visa management and an inflammatory pseudotumoral formation with a more limited surgical management. In emergency, the intraoperative macroscopic examination of the resection piece is essential. Differentiation between tumor and inflammatory aspects is difficult, which is why the presumptive diagnosis and the surgical decision must be inclined to the lesion with the most severe evolutionary potential.

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HUANG, Jie, Weixing YAO, and Xianyang SHAN. "Coupled fluid-thermal investigation on non-ablative thermal protection system with spiked body and opposing jet combined configuration." Chinese Journal of Aeronautics 32, no. 6 (June 2019): 1390–402. http://dx.doi.org/10.1016/j.cja.2019.03.015.

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Selvarajan, Reena Sri, Ruslinda A. Rahim, Burhanuddin Yeop Majlis, Subash C. B. Gopinath, and Azrul Azlan Hamzah. "Ultrasensitive and Highly Selective Graphene-Based Field-Effect Transistor Biosensor for Anti-Diuretic Hormone Detection." Sensors 20, no. 9 (May 6, 2020): 2642. http://dx.doi.org/10.3390/s20092642.

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Nephrogenic diabetes insipidus (NDI), which can be congenital or acquired, results from the failure of the kidney to respond to the anti-diuretic hormone (ADH). This will lead to excessive water loss from the body in the form of urine. The kidney, therefore, has a crucial role in maintaining water balance and it is vital to restore this function in an artificial kidney. Herein, an ultrasensitive and highly selective aptameric graphene-based field-effect transistor (GFET) sensor for ADH detection was developed by directly immobilizing ADH-specific aptamer on a surface-modified suspended graphene channel. This direct immobilization of aptamer on the graphene surface is an attempt to mimic the functionality of collecting tube V 2 receptors in the ADH biosensor. This aptamer was then used as a probe to capture ADH peptide at the sensing area which leads to changes in the concentration of charge carriers in the graphene channel. The biosensor shows a significant increment in the relative change of current ratio from 5.76 to 22.60 with the increase of ADH concentration ranging from 10 ag/mL to 1 pg/mL. The ADH biosensor thus exhibits a sensitivity of 50.00 µA· ( g / mL ) − 1 with a limit of detection as low as 3.55 ag/mL. In specificity analysis, the ADH biosensor demonstrated a higher current value which is 338.64 µA for ADH-spiked in phosphate-buffered saline (PBS) and 557.89 µA for ADH-spiked in human serum in comparison with other biomolecules tested. This experimental evidence shows that the ADH biosensor is ultrasensitive and highly selective towards ADH in PBS buffer and ADH-spiked in human serum.

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