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Статті в журналах з теми "Firing distance"
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Reed, Jamie L., Hui-Xin Qi, Pierre Pouget, Mark J. Burish, A. B. Bonds, and Jon H. Kaas. "Modular Processing in the Hand Representation of Primate Primary Somatosensory Cortex Coexists With Widespread Activation." Journal of Neurophysiology 104, no. 6 (December 2010): 3136–45. http://dx.doi.org/10.1152/jn.00566.2010.
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Neurons in the hand representation of primary somatosensory cortex (area 3b) are known to have discretely localized receptive fields; and these neurons form modules that can be visualized histologically as distinct digit and palm representations. Despite these indicators of the importance of local processing in area 3b, widespread interactions between stimuli presented to locations across the hand have been reported. We investigated the relationship of neuron firing rate with distance from the site of maximum activation in cortex by recording from a 100-electrode array with electrodes spaced 400 μm apart, implanted into the area 3b hand representation in anesthetized owl monkeys. For each stimulated location on the hand, the electrode site where neurons had the highest peak firing rate was defined as the peak activation site. The lesser firing rates of neurons at all other electrode sites in the grid were compared with the firing rates of neurons at the peak activation site. On average, peak firing rates of neurons decreased rapidly with distance away from the peak activation site. The effect of distance on the variance of firing rates was highly significant ( P < 0.0001). However, individual neurons retained high firing rates for distances over 3 mm. The clear decline in firing rate with distance from the most activated location indicates that local processing is emphasized in area 3b, while the distance of neurons with reduced but maintained firing rates ≤3–4 mm from the site of best activation demonstrated widespread activation in primary somatosensory cortex.
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Xu, Zhaopeng, Zhidong Wu, Shunjie Wang, and Yan Zhang. "Research on the simulation of factors influencing maximum firing distance of acoustic homing torpedo." ITM Web of Conferences 45 (2022): 01022. http://dx.doi.org/10.1051/itmconf/20224501022.
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In the torpedo attack, the appropriate firing distance is the key to ensure the torpedo hit the target, it’s necessary to ensure the firing distance used is within the maximum firing distance. Therefore, under the premise of known firing conditions, it’s necessary to determine the maximum firing distance and be familiar with the factors that affect the value and the influencing rules of each factor. Based on the firing model of the acoustic homing torpedo, the expression of the maximum firing distance is established, and the main factors affecting the value are obtained. Through the simulation, the influence factors are analyzed quantitatively, and the rule of their influence on the maximum firing distance is founded out. This research can provide the necessary reference for the commanding officer in battle, in order to make full use of the research results and improve the hit probability of the acoustic homing torpedo.
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Zeichner, Arie, and Baruch Glattstein. "Improved reagents for firing distance determination." Journal of Energetic Materials 4, no. 1-4 (January 1986): 187–97. http://dx.doi.org/10.1080/07370658608011341.
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Zhou, Shi Hai, Zhen Hui Xu, Zhen Jun Yang, and Jian Hui Lu. "Design of Artillery Recoil Distance Automatic Recording and Limit Distance Alarm Device." Advanced Materials Research 977 (June 2014): 409–12. http://dx.doi.org/10.4028/www.scientific.net/amr.977.409.
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Recoil distance is an important evaluation index to reflect the performance of gun recoil mechanism. It can not allow to fire of artillery if recoil distance exceeding the prescribed distance. So it played an important role to ensure the normal firing of artillery. Previous artillery recoil distance is read by artificial indicator through the recoil, which affects the firing efficiency and has no conducive to the implementation of fast attack. This paper designed the gun recoil distance memory and alarm device by using the sensor technology and SCM programming. The device not only can record the recoil distance of each firing projectile and the total number of it but also can alarm if the recoil distance exceeds the specified maximum. The device effectively solves the problem that the recoil indicator artificial read and record. It has practical significance to improve the efficiency of the shooting.
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Gong, Jiuxin, Yuechang Shi, and Mingwei Xu. "Simulated Curved Firing Electromagnetic Gun." Modern Electronic Technology 4, no. 1 (May 27, 2020): 6. http://dx.doi.org/10.26549/met.v4i1.3242.
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The device uses a self-made electromagnetic cannon and a control charging and discharging circuit to constitute the launching device of the electromagnetic cannon. The two-degree-of-freedom control PTZ controls the angle and direction of the electromagnetic cannon. It uses dual power supplies to power the main control board and electromagnetic cannon device. The microprocessor STM32F407 is used as the control core of the electromagnetic cannon, and the TCA8418 IIC matrix keyboard is used to adjust the distance and angle. The OpenMV4 automatically searches for the guide mark and captures the image shape and color blocks in real time to control the electromagnetic cannon to hit the round bullseye. . In addition, it also uses Lidar to measure the distance between the calibration point and the ring target, and uses OpenMV4 to realize the automatic search and launch of the electromagnetic cannon.
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Fu, Q. G., J. I. Suarez, and T. J. Ebner. "Neuronal specification of direction and distance during reaching movements in the superior precentral premotor area and primary motor cortex of monkeys." Journal of Neurophysiology 70, no. 5 (November 1, 1993): 2097–116. http://dx.doi.org/10.1152/jn.1993.70.5.2097.
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1. Single-unit neuronal activity was recorded in the primary motor and superior precentral premotor areas of two rhesus monkeys during an arm reaching task. The task involved moving a cursor displayed on a video terminal using a draftsman's arm-type manipulandum. From a centrally located start box the animal was required to move to 1 of 48 target boxes at eight different directions (0-360 degrees in 45 degrees intervals) and six distances (1.4-5.4 cm in 0.8-cm increments). Both direction and distance for the upcoming movement were unpredictable. 2. The activity of 197 arm movement-related cells was recorded and evaluated for each of the 48 targets. Histological examination showed the cells to be primarily in the primary motor cortex or in the premotor area around the superior precentral sulcus. Each cell's discharge was aligned on movement onset and averaged over five trials for each target. Movement kinematics including hand path velocity were also determined. The task time was divided into three epochs, a premovement period (PT), a movement period (MT), and total time (TT = PT+MT). For each epoch the average firing was correlated with the direction and distance of the movement using various regression procedures. 3. An analysis of variance (ANOVA) showed that the majority of neurons were modulated significantly by movement direction in each of the three time periods, PT (73.7%), MT (68.3%), and TT (78.5%). The relationship of the firing to direction was fit to a cosine tuning function for each significantly modulated cell. In 86.3% of the cells the firing was correlated significantly with a cosine function of movement direction in TT. A cell's preferred direction varied little for different movement distances. The mean difference in preferred direction for the smallest possible change in distance (0.8 cm) was 12.8 +/- 11.4 degrees (SD) and 17.1 +/- 14.7 degrees for the largest change in distance (4.0 cm). 4. Correlation analysis revealed that the activity of the majority of cells was modulated significantly by distance along at least one direction in each of the three time periods, PT (46.8%), MT (68.8%), and TT (67.7%). Subsequently, a univariate linear regression model was used to quantify a cell's discharge as a function of distance. For the regressions of firing with distance with a statistically significant correlation (r > 0.8), the mean slope was 3.59 +/- 0.17 spikes.s-1.cm-1 for the total time. The existence of a significant distance modulation was not invariably correlated with a cell's preferred movement direction.(ABSTRACT TRUNCATED AT 400 WORDS)
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Jeewajee, A., C. Barry, V. Douchamps, D. Manson, C. Lever, and N. Burgess. "Theta phase precession of grid and place cell firing in open environments." Philosophical Transactions of the Royal Society B: Biological Sciences 369, no. 1635 (February 5, 2014): 20120532. http://dx.doi.org/10.1098/rstb.2012.0532.
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Place and grid cells in the rodent hippocampal formation tend to fire spikes at successively earlier phases relative to the local field potential theta rhythm as the animal runs through the cell's firing field on a linear track. However, this ‘phase precession’ effect is less well characterized during foraging in two-dimensional open field environments. Here, we mapped runs through the firing fields onto a unit circle to pool data from multiple runs. We asked which of seven behavioural and physiological variables show the best circular–linear correlation with the theta phase of spikes from place cells in hippocampal area CA1 and from grid cells from superficial layers of medial entorhinal cortex. The best correlate was the distance to the firing field peak projected onto the animal's current running direction. This was significantly stronger than other correlates, such as instantaneous firing rate and time-in-field, but similar in strength to correlates with other measures of distance travelled through the firing field. Phase precession was stronger in place cells than grid cells overall, and robust phase precession was seen in traversals through firing field peripheries (although somewhat less than in traversals through the centre), consistent with phase coding of displacement along the current direction. This type of phase coding, of place field distance ahead of or behind the animal, may be useful for allowing calculation of goal directions during navigation.
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Even, Haviva, Pinchas Bergman, Eliot Springer, and Asne Klein. "The Effects of Water-Soaking on Firing Distance Estimations." Journal of Forensic Sciences 33, no. 2 (March 1, 1988): 11945J. http://dx.doi.org/10.1520/jfs11945j.
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Marty, W., T. Sigrist, and D. Wyler. "Determination of firing distance using the rhodizonate staining technique." International Journal of Legal Medicine 116, no. 1 (February 1, 2002): 1–4. http://dx.doi.org/10.1007/s004140100220.
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Bartha, Attila, and D. Dumitrescu. "Perturbation in Population of Pulse-Coupled Oscillators Leads to Emergence of Structure." International Journal of Computers Communications & Control 6, no. 2 (January 6, 2011): 222. http://dx.doi.org/10.15837/ijccc.2011.2.2169.
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A new synchronization model based on pulse-coupled oscillators is proposed. A population of coupled oscillators is represented as a cellular automaton. Each cell periodically enters a firing state. Firing of a cell is sensed by other cells in a neighborhood of radius R. As a result the sensing cell may change its firing rate. The interaction strength between a firing and a sensing cell decreases with the squared distance between the two cells. For most starting conditions waves of synchronized firing cells emerge. Simulations indicate that for certain parameter values the emergence of synchronization waves occurs only if there is dispersion in the intrinsic firing frequencies of the cells. Emergence of synchronization waves is an important feature of the model.
Дисертації з теми "Firing distance"
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Duarte, Mafalda de Prata Neves. "Firing distance estimation through the quantification of gunshot residues in blowfly larvae (calliphoridae family) using inductively coupled plasma-mass spectrometry." Master's thesis, 2015. https://repositorio-aberto.up.pt/handle/10216/80812.
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Duarte, Mafalda de Prata Neves. "Firing distance estimation through the quantification of gunshot residues in blowfly larvae (calliphoridae family) using inductively coupled plasma-mass spectrometry." Dissertação, 2015. https://repositorio-aberto.up.pt/handle/10216/80812.
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CECCHETTO, Giovanni. "Radiological detection of gunshot redisue in firearm wounds." Doctoral thesis, 2012. http://hdl.handle.net/11562/392923.
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Introduzione
La valutazione della distanza di sparo assume frequente e rilevante importanza. Ad oggi, le procedure impiegate nella determinazione del firing range sono basate sull’analisi della distribuzione dei residui di sparo (gunshot residue – GSR). Fenomeni fisici e chimici agenti nel post-mortem possono alterare le caratteristiche delle ferite d’arma da fuoco, complicando la ricostruzione della dinamica delittuosa.
Scopo dello studio
Il presente studio si propone di identificare, quantificare e comparare il GSR su diverse tipologie di ferite d’arma da fuoco, mediante analisi radiologiche di ultima generazione (micro-TC).
Materiali e metodi
Il campione casistico è costituito da 110 segmenti di gambe umane amputate chirurgicamente e sottoposte a prove di sparo da differenti distanze (5, 15, 23, 30 e 40 cm). Come controlli sono state usate 30 ferite da punta prodotte su gambe umane. Sessanta campioni (10 per ogni distanza testata e 10 ferite da punta) sono stati immediatamente fissati in formalina. Quaranta campioni (10 ferite prodotte da 5 cm, da 15 cm e da 30 cm e 10 ferite da punta) sono stati lasciati esposti all’aria aperta per 15 giorni prima di essere fissati in formalina. Quaranta campioni (10 ferite prodotte da 5 cm, da 15 cm e da 30 cm e 10 ferite da punta) sono stati posti all’interno di una stufa a legna ed esposti alle fiamme per 4 minuti a 400°C prima di essere fissati in formalina.
Ciascun segmento è stato quindi analizzato con micro-TC.
Risultati
L’analisi con micro-TC ha rilevato GSR su tutte le ferite d’entrata d’arma da fuoco. Nei campioni freschi, i residui inorganici di sparo erano concentrati sulla cute attorno al foro e negli strati sottocutanei attorno al tramite. Nei campioni putrefatti il GSR era localizzato prevalentemente nel sottocute. Nei campioni carbonizzati i residui erano in parte costituiti da aggregati di particelle metalliche fuse tra loro. Nei fori di uscita e nelle ferite da punta non sono state rilevate particelle metalliche. L’analisi statistica ha rilevato un decremento non lineare tra la quantità di GSR e la distanza di sparo.
Conclusioni
Il presente studio rappresenta la prima applicazione della micro-TC in ambito di balistica forense. Nei campioni freschi, la metodica utilizzata, rapida e oggettiva, permette di discriminare chiaramente i colpi sparati alle diverse distanze testate. Nei campioni putrefatti e carbonizzati, l’analisi con micro-TC fornisce utili informazioni per discriminare ferite d’entrata d’arma da fuoco da ferite con caratteristiche morfometriche simili (fori d’uscita e/o ferite da punta).
La stima della sensibilità e specificità del metodo testato sarà verificata mediante analisi di ferite derivanti da casi forensi e dalla verifica dei risultati ottenuti con tecniche “gold standard”, quali la microscopia elettronica a scansione ambientale accoppiata ad un rilevatore a dispersione di energia, che confermino la reale composizione chimica dei residui rilevati sul bersaglio.Introduction Estimation of the firing range is often critical for reconstructing gunshot fatalities, where the main measurable evidence is the gunshot residue (GSR). After-death events, such as putrefaction, autolysis, incineration or extensive burning of the body, can alter the typical macroscopic and microscopic characteristics of firearm wounds, hampering or at least complicating the reconstruction of gunshot fatalities. Aim of the research project The present study aimed at evaluating and comparing the amount and differential distribution of GSR on fresh, decomposed, and charred gunshot wounds, utilizing a micro-computed tomography (micro-CT) analysis. Materials and methods A total of 110 experimental shootings at different firing distances (5, 15, 23, 30, and 40 cm) were performed on human calves surgically amputated for medical reasons. As controls we used 30 stab wounds, produced with an ice pick on calf sections. Sixty specimens (10 for each tested distance and 10 stab wounds) were immediately formalin-fixed. Forty specimens (10 gunshot wounds from 5, 15, and 30 cm, and 10 stab wounds) were enclosed in a cowshed for 15 days, before formalin-fixation. Forty specimens (10 gunshot wounds from 5, 15, and 30 cm, and 10 stab wounds) were placed inside a wood-burning stove for 4 minutes at a temperature of 400°C. All the samples were analysed by a micro-CT coupled to an imaging analysis software. Results Micro-CT analysis with three-dimensional image reconstruction detected GSR particles in all the investigated entrance wounds. In fresh specimens, GSR was concentrated on the skin surface around the entrance hole, and in the epidermis and dermis layers around the cavity. In decomposed specimens the high-density particles were detected only in the dermis layer. Regarding the charred wounds, the GSR deposits of the firearm lesions inflicted at very close distance (5 cm) were mainly constituted of huge particles with an irregular shape and well-delineated edges; at greater distances, agglomerates of tiny radiopaque particles scattered in the epidermis and dermis layers were evident. No GSR was detected in exit holes and stab wounds. Statistical analysis showed a nonlinear relationship between the amount of GSR deposits and the firing range. Conclusions Our study, which is the first application of micro-CT analysis in the field of forensic ballistics, demonstrates that micro-CT could be an objective and rapid tool for the analysis of gunshot wounds in firearm fatalities. On fresh samples, this method may be of practical use for estimating the firing range given a known percentage of the GSR deposit, while in bodies in advanced decomposition or extremely damaged by fire, it might furnish precious information on the nature and means of productions of an injury, playing an important role for reconstructing the shooting incident. For estimating the sensitivity and specificity of the proposed method, it will be necessary to test the micro-CT, analysing specimens of forensic caseworks and confirming the positive results with a “gold-standard” method.
Книги з теми "Firing distance"
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Thackeray, Thomas James. Soldier's Manual of Rifle Firing at Various Distances. Creative Media Partners, LLC, 2018.
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Thackeray, Thomas James. Soldier's Manual of Rifle Firing, at Various Distances. Creative Media Partners, LLC, 2018.
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Thackeray, Thomas James. Three Lectures ... on the Practice of Rifle Firing at Various Distances. HardPress, 2020.
Знайти повний текст джерелаЧастини книг з теми "Firing distance"
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"Terminal/Wound Ballistics and Distance Firing." In Firearms, the Law, and Forensic Ballistics, Third Edition, 183–232. CRC Press, 2011. http://dx.doi.org/10.1201/b11451-8.
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"Terminal/Wound Ballistics and Distance of Firing." In Firearms, the Law, and Forensic Ballistics, 168–211. CRC Press, 2004. http://dx.doi.org/10.1201/9780203568224-16.
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"Terminal/Wound Ballistics and Distance of Firing." In Firearms, the Law, and Forensic Ballistics, Second Edition. CRC Press, 2004. http://dx.doi.org/10.1201/9780203568224.ch7.
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Ravreby, Mark. "Determination of Firing Distance by Total Nitrite." In Anti-Terrorism; Forensic Science; Psychology in Police Investigations, 320–27. Routledge, 2019. http://dx.doi.org/10.4324/9780429036590-39.
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Csizmadia, György, and Robert U. Muller. "Storage of the Distance between Place Cell Firing Fields in the Strength of Plastic Synapses with a Novel Learning Rule." In Hippocampal Place Fields, 343–50. Oxford University Press, 2008. http://dx.doi.org/10.1093/acprof:oso/9780195323245.003.0025.
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Eimeleus, K. B. E. E. "Instruction of Ski Detachments with Marching and Company Battle Formation, Referencing “Infantry Drill Regulations”1." In Skis in the Art of War, translated by William D. Frank and E. John B. Allen, 94–97. Cornell University Press, 2019. http://dx.doi.org/10.7591/cornell/9781501747403.003.0025.
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This chapter contains instructions for ski detachments in platoons and companies. It first provides the parade formations for a platoon, with directions for forming up, turning, and movement. The chapter then turns to company formations. In all forming up of the platoon and company, the intervals and distances between individuals are the same as those indicated for the platoon parade line. Finally, the chapter turns to company battle-arrays. It provides instructions for when the ski detachments are caught under live fire during actual battle, in which case particular importance accrues to prolonged, rapid running. Furthermore, on the firing line, a rifleman can either be on skis or have skis removed and then drag them behind, according to his preference.
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Grossberg, Stephen. "Learning Maps to Navigate Space." In Conscious Mind, Resonant Brain, 572–617. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780190070557.003.0016.
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This chapter explains how humans and other animals learn to learn to navigate in space. Both reaching and route-based navigation use difference vector computations. Route navigation learns a labeled graph of angles and distances moved. Spatial navigation requires neurons to learn navigable spaces that can be many meters in size. This is again accomplished by a spectrum of cells. Such spectral spacing supports learning of medial entorhinal grid cells and hippocampal place cells. The model responds to realistic rat navigational trajectories by learning grid cells with hexagonal grid firing fields of multiple spatial scales, and place cells with one or more firing fields, that match neurophysiological data about their development in juvenile rats. Both grid and place cells develop in a hierarchy of self-organizing maps by detecting, learning and remembering the most frequent and energetic co-occurrences of their inputs. Model parsimonious properties include: similar ring attractor mechanisms process linear and angular path integration inputs that drive map learning; the same self-organizing map mechanisms can learn both grid cell and place cell receptive fields; and the learning of the dorsoventral organization of multiple grid cell modules through medial entorhinal cortex to hippocampus uses a gradient of rates that is homologous to a rate gradient that drives adaptively timed learning at multiple rates through lateral entorhinal cortex to hippocampus (‘neural relativity’). The model clarifies how top-down hippocampal-to-entorhinal ART attentional mechanisms stabilize map learning, simulates how hippocampal, septal, or acetylcholine inactivation disrupts grid cells, and explains data about theta, beta and gamma oscillations.
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Klein, Christopher J. "Autoimmune Peripheral Nervous System Hyperexcitability." In Mayo Clinic Cases in Neuroimmunology, edited by Andrew McKeon, B. Mark Keegan, and W. Oliver Tobin, 138–39. Oxford University Press, 2021. http://dx.doi.org/10.1093/med/9780197583425.003.0044.
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A 25-year-old man was seen for assessment of progressive pain. He had a distant history of Guillain-Barré syndrome at age 8 years, at which time he had symmetrical proximal and distal weakness of the upper and lower extremities with loss of ambulation. No facial weakness, dysarthria, dysphagia, ptosis, diplopia, or respiratory weakness occurred. At his initial evaluation there was touch hypersensitivity of the muscles and skin. He had no weakness or cognitive involvement, although the pain made it difficult for him to concentrate. His creatine kinase value improved with hydration, but pain and muscle twitching persisted. On examination, he had diffuse extremity and truncal fasciculations and myokymia and reported pain in not only the areas of twitching but also other areas of his extremities and trunk. On neurophysiologic testing, fibular and tibial motor compound muscle action potentials were decreased in amplitude, with normal ulnar and median motor responses. Needle electromyography of muscles proximally and distally showed diffuse spontaneous firing of muscles ranging in frequency with waxing and waning characteristics. These findings were thought to be consistent with a primary hyperexcitable disorder of muscles with a superimposed old polyradiculoneuropathy and possibly a myopathy. Expanded autoimmune neuroimmunologic testing of serum identified immunoglobulin G-directed cerebellar molecular staining consistent with voltage-gated potassium channel autoantibodies. Radioimmunoprecipitation assay identified voltage-gated potassium channel-immunoglobulin Gs and led to reflex testing for contactin-associated protein 2-immunoglobulin G; autoantibodies were positive. Computed tomography of the chest with contrast was performed, and lymphadenopathy was identified. The patient was clinically diagnosed with contactin-associated protein 2 - immunoglobulin G–positive Isaacs syndrome. A trial of high-dose gabapentin was attempted, with only mild benefits. Next, intravenous immunoglobulin was initiated. Diabetes developed, and he was hospitalized requiring initiation of insulin. His condition is now managed variably with intravenous immunoglobulin and scheduled daily gabapentin. The immune system has long been recognized to help regulate pain via non- immunoglobulin G–mediated mechanisms. Specifically, cytokines decrease the nociceptive nerve fiber thresholds and are released after diverse tissue insults. This allows for speeded healing by increased blood flow and protection of the region by pain guarding mechanisms. It is now recognized that, in rare cases, immunoglobulin G-mediated autoimmunity can lead to otherwise idiopathic pain disorders.
Тези доповідей конференцій з теми "Firing distance"
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Held, Manfred. "Optical test method to measure the corner turning and the retonation distance in one firing." In Twenty-Third International Congress on High-Speed Photography and Photonics, edited by Valentina P. Degtyareva, Mikhail A. Monastyrski, Mikhail Y. Schelev, and Alexander V. Smirnov. SPIE, 1999. http://dx.doi.org/10.1117/12.350499.
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Stalder, Jean-Pierre, and Phil Roberts. "Firing Low Viscosity Liquid Fuels in Heavy Duty Gas Turbines." In ASME Turbo Expo 2003, collocated with the 2003 International Joint Power Generation Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/gt2003-38691.
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Sustained economic growth has created a strong demand for electrical energy worldwide. Security of fuel supply and cost are therefore very often critical issues for thermal capacity additions. Also the distance from fuel sources and available fuel transport infrastructure is an important factor in the cost of generation. Many plant locations have only limited supplies of conventional gas turbine fuels, namely natural gas and distillate fuels, thus a drive to diversify the fuels involved. For other electricity producers, the optimal use of existing or potential fuel resources is a must for economical reasons. Therefore, the possibility of using alternative gas turbine liquid fuels, such as volatile and/or low viscosity fuels like naphtha, gas condensates, kerosene, methanol, ethanol, or low lubricity distillate fuels; refinery by-products such as BTX fuels (benzene-toluene-xylene mixtures), LCO-light cycle oil, or in the future synthetic fuels (GTL) are particularly interesting for their ability to be fired in heavy duty gas turbines. However, the practical use of these fuels creates specific issues such as low lubricity properties which can affect sensitive key components like fuel pumps and flow dividers. This paper addresses the many practical aspects of using fuel lubricity additives for reduced component wear in gas turbine fuel systems, and for reliability and successful plant operation on these alternative gas turbine liquid fuels. Also an overview of acquired experience is given.
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Norvell, Kyle, Michael McClelland, Ethan Ratajczak, and Janet Dong. "Design and Build a T-Shirt Cannon Firing Mechanism." In ASME 2020 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/imece2020-24112.
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Abstract The work in this paper is a part of the T-shirt cannon automation project. The objective of the project is to develop an autonomous robot carrying cannons to automatically shoot T-shirts during the sports events at the University of Cincinnati (UC). More specifically, the T-shirt cannon will be used and driven by the UC cheerleading team and be able to automatically shoot T-shirts at the audience in the Nippert Stadium and the 5/3 Arena for football and basketball games, respectively. The design and automation of the T-shirt cannon require a significant effort and a multi-disciplinary team to complete. This paper will focus on the process of designing, building, and testing the firing mechanism for the cannon, including the determination of cannon’s firing method, barrel design and assembly, base design and barrel mounting method, pneumatic analysis, and automation and control of the firing of T-shirts. The goal of the firing mechanism is that the cannon would fire off as many T-shirts as possible with the window of a single timeout at the game. The project starts with the preliminary research and the initial testing. During the preliminary research, the relevant safety standards/codes and previous T-shirt cannon designs were reviewed and studied. Especially the possible working with pressurized air, the material used in the design must be rated above the target firing pressure to ensure the cannon itself not explode and the air supply tank and fittings must be in good condition. During the initial testing, the site visits were conducted, the cheerleaders were interviewed, the dimensions of the stadium and the 5/3 arena were measured, and therefore the shooting distance and shooting angles were estimated. After the initial testing and preliminary research, a set of engineering characteristics were established, following by the concept design, in which the barrel assembly, the pneumatics, the firing mechanism, and the mounting method were discussed, analyzed, and determined. The barrels had two major designs, one is using a railing support system with an external tank of air to power and fire the cannon, and another one is using a chamber of air to power and fire the cannon with the barrels surrounding the air chamber itself. Two methods are analyzed and compared. The optimum one, therefore, was determined and developed. For the firing mechanism, two main designs are a spring-loaded firing mechanism that could increase the sealing capabilities of the barrels, and a tight tolerance fit that has less weight. Two designs were tested and analyzed, the optimum one was determined and built, followed by the firing mechanism testing. This paper will describe the process of design, building, and testing the firing mechanisms of this T-shirt cannon at UC. The paper will also discuss the testing results on shooting performance.
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Ahmed, Nadeem, R. D. Brown, and J. G. Hetherington. "Modeling of Dynamic Interaction Between Gun System Components During the Recoil Motion of the Gun." In ASME 2009 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2009. http://dx.doi.org/10.1115/detc2009-87292.
Повний текст джерелаАнотація:
The accuracy and consistency of a large caliber gun is largely dependent on its dynamic response during the firing cycle. A number of factors affecting the dynamic response of the gun include, the offset masses attached to the barrel, offset forces acting at a distance from the barrel axis and the dynamic interaction between the gun system components, including the shot-barrel interaction. Computer based modelling techniques can be used to model and simulate the motion of the gun during the firing cycle. These techniques are helpful in predicting the dynamic response of the gun system as well as the accuracy and consistency of the gun. A finite element computer modelling program ‘ANSYS’ was used to model a 120mm direct fire tank gun and simulate the dynamic response during the recoil motion. The contact algorithm in ‘ANSYS’ was used to simulate physical interaction between the gun system components. Simulations were also carried out in the Gun Dynamics program ‘SIMBAD’ by using the same gun system profile and the results obtained from both programs were compared. A case study is also presented to investigate the effect of gun design parameters on the dynamic response of the gun.
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Park, Hyunjae, Anthony Bowman, Tod Stansfield, Brian Huibregtse, Steve Wilkinson, and Willie Ayala. "Prediction of Water Circulation Characteristics in a 4-Pass Firetube Boiler With the Non-Symmetric Arrangement of Tube Passes 3 and 4." In ASME 2001 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2001. http://dx.doi.org/10.1115/imece2001/aes-23603.
Повний текст джерелаАнотація:
Abstract Water circulation characteristics, for a newly designed 4-pass 300 BHP (Boiler Horse Power) firetube boiler with a non-symmetric arrangement of tube passes 3 and 4, are investigated in this paper by means of measured furnace wall temperatures for different boiler firing conditions. Vapor production rate and intensity, at each of the 28 temperature measurement nodes, is approximated using the nodal temperature in conjunction with a nucleate boiling heat transfer mode on the water side of the furnace. Defining an attraction force that is proportional to the relative difference of the evaporation intensity between two nodes and inversely proportional to the distance between, the two-dimensional components of the attraction force can be calculated. Integrating all attraction force vectors between a node and the surrounding nodes produces a representative attraction force vector at the node. Similar calculation of the attraction force vectors at all of the temperature nodes on the furnace wall will characterize the water circulation near the boiler furnace. Investigations of the analysis results reveal various complicated non-symmetric water circulation patterns for different boiler firing conditions. Consequently, the analysis methods employed in this paper can be used to predict and improve the water circulation in a firetube boiler, particularly with regard to the placement of the boiler feed-water inlet location.
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SHARMA, SANGEETA, A. ANANDARAJ, and SANJAY KUMAR. "EFFECT OF BOURRELET LENGTH ON MAGNUS MOMENTS AND FLIGHT STABILITY OF THE PROJECTILE." In 32ND INTERNATIONAL SYMPOSIUM ON BALLISTICS. Destech Publications, Inc., 2022. http://dx.doi.org/10.12783/ballistics22/36131.
Повний текст джерелаАнотація:
Aerodynamic design of an artillery shell often presents a challenging situation for the designer. Design parameters which enhance in-bore performance of shell in terms of reduced balloting & acceptable yaw rates at the muzzle end, in-turn disturbs the in-flight stability in certain flight regime. Similarly, design parameters which enhances in-flight static & dynamic stability, adversely affect the motion of shell inside barrel. Hence, an optimal selection of values of each design parameter is mandatory to attain desired performance of the ammunition both outside and inside the barrel. One of such design parameters is the Bourrelet distance or wheelbase, which is considered for this study. Parametric studies to evaluate comparative aerodynamic performance of artillery shell with varying bourrelet distance in terms of four major performance parameters such as Muzzle Jump Factor (MJF), Drag characteristics, Gyroscopic Stability & Dynamic Stability are carried out using commercially available software, PRODAS Version 3.2. Out of these four parameters, only MJF & Dynamic stability parameters are analysed in detail in the present work. Comparative values of MJF are used to evaluate inbore stability in terms of initial yaw rate at muzzle exit. Dynamic stability is evaluated in terms of Magnus moment generated by spinning shell. Effect of Magnus moment in terms of total angle of attack damping response during flight is studied by simulating trajectory of the shell for all firing zones. To study the effect of bourrelet distance on performance parameters, bourrelet distance is varied from 0.6 Cal to 1.4 Cal, where Cal is the maximum
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KUMAR, DINESH, BALKISHAN PAL, BALWINDER KUMAR, and VIKAS BHARDWAJ. "A REVIEW OF FUTURE TRENDS IN 3-D PRINTING OF ARMAMENT AND EXPLOSIVE DEVICES." In 32ND INTERNATIONAL SYMPOSIUM ON BALLISTICS. Destech Publications, Inc., 2022. http://dx.doi.org/10.12783/ballistics22/36044.
Повний текст джерелаАнотація:
Advances in Computer aided design (CAD), modeling and Three-dimensional (3D) printing has led to paradigm shift in development of innovative and miniaturized explosive devices for armament applications. In conventional techniques, explosives are either pressed or casted and machined to required geometry. These conventional processes are mostly manual and monotonous; require high-cost tooling and the lead-time from concept to product is high. 3D printing is an automated additive manufacturing process in which the material is deposited layer-by-layer to build physical part with any intricate geometry and profile, from the CAD model of the part. 3D printing of explosive devices offers advantages of computer aided design techniques, automation, direct physical part fabrication, low lead-time, low cost and any geometrical shape can be printed. It also offers advantage of printing explosive parts in the battlefields. In this paper, along with the detailed review of future trends in 3D printing of armament and explosive devices, a case study of 3D printing of plastic bullets in Acrylonitrile Butadiene Styrene (ABS) material is presented. The plastic bullets are used in low intensity conflicts and riot control. The experimental firing trials were conducted using standard AK- 47 gun firing on Gelatin target blocks placed at 30 m distance from the muzzle of the gun. The trials showed performance of ABS bullets in terms of lethality and velocity drop comparable to existing plastic bullets made of Nylon-66 manufactured by injection molding process. 3D printed ABS bullets have advantage of batch-to-batch repeatability, high accuracy. 3D printing is revolutionizing the way armament and explosive devices are manufactured, performance improvement and miniaturization.
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Chewning-Kulick, Travis G., Marvin E. Lewis, Michael J. Benson, Joshua M. Keena, and Matthew A. Posner. "Risk Assessment of Air Cannons at Sporting Events." In ASME 2016 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/imece2016-67213.
Повний текст джерелаАнотація:
This study looked to determine the safety of air cannons used at public events based on experimentally collected ballistic data. Specifically, the probable injuries to bystanders resulting from being hit by various projectiles launched from air cannons were investigated. Due to the rapid deceleration of projectiles fired from air cannons as they travel through the air, this study focuses on the worst case scenario: point blank impacts. Based on data collected using a chronograph and force plate, this study asserts that it is likely an air cannon operating under the conditions of this experiment can cause significant ocular, maxillofacial, laryngeal, and extremity injuries. To mitigate the risks posed by using air cannons, this study recommends the use of safety glasses for operators, mandatory operator training, automatic trigger locking mechanisms, frequent inspections of the cannon, regulations on the projectiles that can be fired, and the establishment of a minimum firing distance between the operator and bystanders.
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Baskurt, U. J., Peter M. Bradshaw, and James D. Hart. "Slackline Testing of the TransAlaska Pipeline System at Thompson Pass." In 1998 2nd International Pipeline Conference. American Society of Mechanical Engineers, 1998. http://dx.doi.org/10.1115/ipc1998-2096.
Повний текст джерелаАнотація:
During the summer of 1996, the TransAlaska Pipeline System (TAPS) experienced a vibration problem near Thompson Pass which is 25 miles north of Valdez and is part of the Chugach Mountain Range, the most southerly of the three mountain ranges which the pipeline crosses on its route from Prudhoe Bay to the Port of Valdez. The vibrations could, on occasion, be detected by residents living near the pipeline at the bottom of the pass. Close to the source of the phenomena, small bushes could be seen moving in response to the seismic shocks and a noise similar to “mortars firing in the distance” could be heard. Alyeska Pipeline Service Company initiated an extensive investigation and quickly determined that the seismic shocks were a result of pressure pulses originating near the slackline-packline interface. This only occurred when the slackline-packline interface was positioned near a terraced portion of the pipeline topography on the downstream side of the pass. This knowledge allowed Alyeska Pipeline to control the pulsations by backpressuring the pipeline and moving the slackline-packline interface well above the terrace location.
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Srinivasa Rao, D., D. Sen, K. R. C. Somaraju, S. Ravi Kumar, N. Ravi, and G. Sundararajan. "The Influence of Powder Particle Velocity and Temperature on the Properties of Cr3C2-25NiCr Coating Obtained by Detonation-Gun." In ITSC 1998, edited by Christian Coddet. ASM International, 1998. http://dx.doi.org/10.31399/asm.cp.itsc1998p0385.
Повний текст джерелаАнотація:
Abstract The detonation gun (D-Gun) coating technology which results in coatings with outstanding properties has found extensive applications especially in the aerospace and engineering industry. Though the D-Gun process has been in use for the last 30 years or so, the basic mechanisms which lead to such an outstanding combinations of properties is not yet fully understood. This has been primarily due to the fact that the coating property ultimately depends on the combination of powder particle temperature and velocity at the time of its impact on the substrate to be coated and so far measurement of these parameters has not been possible. As a result, indirect correlations between D-Gun variables like fuel gas to oxygen ratio, powder feed rate, firing frequency and working distance and coating properties have been developed but without the knowledge base of how these D-Gun variables affect the powder particle temperature and velocity. An in-flight particle diagnostic sensing system has been recently installed in our laboratory and this system allows for the simultaneous measurement of particle velocity and temperature. In view of the above, a major programme has been launched to study the effect of particle velocity and temperature on the coating properties (like coating hardness, porosity, bond strength, XRD etc.) for a wide range of coatings. The preliminary results from the above investigation, pertaining to Cr3C2-25NiCr coatings obtained using D-Gun, will be presented and discussed in this paper.