Journal articles: 'Physical principles during collision'

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Saayman, R. "Die fisika van motorbotsings en padverkeersveiligheid." Suid-Afrikaanse Tydskrif vir Natuurwetenskap en Tegnologie 10, no. 3 (July 8, 1991): 112–36. http://dx.doi.org/10.4102/satnt.v10i3.500.

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A survey is given of the interdependent physical variables and principles relevant to the motion of a road vehicle in a traffic situation and its application to analyse and prevent actual collisions. As introduction recent RSA collision statistics and research results on contributing factors and types of collisions which occur, are presented. Then speed as cause is investigated with a discussion of the relative velocity between vehicles; stopping ability and safe following distances; the decision to stop or not at a changing traffic light; as well as estimations of the speed before collisions from wheel skidding marks and projectile flips and vaults. Thirdly vehicle stability is discussed with applications of weight displacement during sudden accelerations; explanations for skidding out of and turning over on a road bend; as well as load displacement.

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Borkowski, Piotr, Zbigniew Pietrzykowski, and Janusz Magaj. "The Algorithm of Determining an Anti-Collision Manoeuvre Trajectory Based on the Interpolation of Ship’s State Vector." Sensors 21, no. 16 (August 6, 2021): 5332. http://dx.doi.org/10.3390/s21165332.

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The determination of a ship’s safe trajectory in collision situations at sea is one of the basic functions in autonomous navigation of ships. While planning a collision avoiding manoeuvre in open waters, the navigator has to take into account the ships manoeuvrability and hydrometeorological conditions. To this end, the ship’s state vector is predicted—position coordinates, speed, heading, and other movement parameters—at fixed time intervals for different steering scenarios. One possible way to solve this problem is a method using the interpolation of the ship’s state vector based on the data from measurements conducted during the sea trials of the ship. This article presents the interpolating function within any convex quadrilateral with the nodes being its vertices. The proposed function interpolates the parameters of the ship’s state vector for the specified point of a plane, where the values in the interpolation nodes are data obtained from measurements performed during a series of turning circle tests, conducted for different starting conditions and various rudder settings. The proposed method of interpolation was used in the process of determining the anti-collision manoeuvre trajectory. The mechanism is based on the principles of a modified Dijkstra algorithm, in which the graph takes the form of a regular network of points. The transition between the graph vertices depends on the safe passing level of other objects and the degree of departure from the planned route. The determined shortest path between the starting vertex and the target vertex is the optimal solution for the discrete space of solutions. The algorithm for determining the trajectory of the anti-collision manoeuvre was implemented in autonomous sea-going vessel technology. This article presents the results of laboratory tests and tests conducted under quasi-real conditions using physical ship models. The experiments confirmed the effective operation of the developed algorithm of the determination of the anti-collision manoeuvre trajectory in the technological framework of autonomous ship navigation.

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Zhong, Xiang Qiang, Li Dong Liang, and Yan Hong Yang. "Research on Ship Part Nesting System Based on Energy Principle and Intelligent Optimization." Advanced Materials Research 694-697 (May 2013): 2771–74. http://dx.doi.org/10.4028/www.scientific.net/amr.694-697.2771.

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A nesting system based on minimum potential energy principle and intelligent optimization for ship part nesting problem was proposed. Discussing polygon judgment and separation, intersection test and collision problems of ship parts, a kind of polygon overlap detection method was put forward, and contacting process was analyzed by use of envelope rectangle intersection test algorithm; During analyzing ship part nesting process based on minimum potential energy principle and genetic algorithm fusion, basic physical meaning of nesting problem was explained from mechanics. Throng intelligent ship part nesting system verification, the algorithm is feasible, physical meaning is clear; it can realize ship part nesting.

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SMITH, RUSSELL. "Optical reflection and mechanical rebound: the shift from analogy to axiomatization in the seventeenth century. Part 1." British Journal for the History of Science 41, no. 1 (September 27, 2007): 1–18. http://dx.doi.org/10.1017/s0007087407000362.

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AbstractThis paper aims to show that the seventeenth-century conception of mechanics as the science of particles in motion founded on universal laws of motion owes much to the employment of a new conceptual resource – the physics of motion developed within optics. The optical analysis of reflection was dynamically interpreted through the mechanical analogy of rebound. The kinematical and dynamical principles so employed became directly applicable to natural phenomena after the eventual transformation of light's ontological status from that of an Aristotelian ‘quality’ to a corpuscular phenomenon, engendered by the rise of atomism during the first half of the seventeenth century. The mechanization of light led to a conceptual shift from the analogical employment of dynamical principles in the physical interpretation of reflection to the mechanical generalization of optical principles – the direct application of kinematical and dynamical principles of reflection to mechanical collisions. This first part of the paper traces out the first conceptual shift from Aristotle's original analogy of reflection as rebound to its full concretization. A second part will trace out the second conceptual shift, from the full concretization of this analogy to the axiomatization of already generalized kinematical and dynamical principles of reflection into laws of nature and of motion.

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Wang, Fei, Zhanqing Li, Qi Jiang, Gaili Wang, Shuo Jia, Jing Duan, and Yuquan Zhou. "Evaluation of hygroscopic cloud seeding in liquid-water clouds: a feasibility study." Atmospheric Chemistry and Physics 19, no. 23 (December 11, 2019): 14967–77. http://dx.doi.org/10.5194/acp-19-14967-2019.

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Abstract. An airborne cloud seeding experiment was conducted over the eastern coast of Zhejiang, China, on 4 September 2016 during a major international event held in Hangzhou. In an attempt to reduce the likelihood of rainfall onset, a major airborne experiment for weather modification took place by seeding hygroscopic agents to warm clouds to reduce cloud droplet size. The effectiveness of seeding is examined, mainly for stratiform clouds with patchy small convective cells. A radar-domain-index (RDI) algorithm was proposed to analyze the seeding effect. The threshold strategy and the tracking radar echo by correlation (TREC) technique was applied in the domain selection. Factors analyzed include echo reflectivity parameters such as the mean and maximum echo intensity, the anomaly percentage of the grid number of effective echoes, the fractional contribution to the total reflectivities, and the vertically integrated liquid (VIL) water content during and after the seeding process. About 12 min after seeding ended, the composite reflectivity of seeded clouds decreased to a minimum (< 10 dBz) and the VIL of seeded clouds was ∼0.2 kg m−3. The echo top height dropped to ∼3.5 km, and the surface echoes were also weakened. By contrast, there was no significant variation in these echo parameters for the surrounding non-seeded clouds. The seeded cell appeared to have the shortest life cycle, as revealed by applying the cloud-cluster tracking method. The airborne Cloud Droplet Probe (CDP) measured cloud number concentration, effective diameter, and liquid water content, which gradually increased after the start of cloud seeding. This is probably caused by the hygroscopic growth of agent particles and collision–coalescence of small cloud droplets. However, these parameters sampled at ∼40 min after seeding decreased significantly, which is probably due to the excessive seeding agents generating a competition for cloud water and thus suppressing cloud development and precipitation. Overall, the physical phenomenon was captured in this study, but a more quantitative in-depth analysis of the underlying principle is needed.

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Leng, Yu-Quan, Zheng-Cang Chen, Xu He, Yang Zhang, and Wei Zhang. "Collision Sensing Using Force/Torque Sensor." Journal of Sensors 2016 (2016): 1–10. http://dx.doi.org/10.1155/2016/6291216.

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Collision sensing including collision position, collision direction, and force size could make robots smoothly interact with environment, so that the robots can strongly adapt to the outside world. Skin sensor imitates principles of human skin using special material and physical structure to obtain collision information, but this method has some disadvantages, such as complex design, low sampling rate, and poor generality. In this paper, a new method using force/torque sensor to calculate collision position, collision direction, and force size is proposed. Detailed algorithm is elaborated based on physical principle and unified modeling method for basic geometric surface. Gravity compensation and dynamic compensation are also introduced for working manipulators/robots in gravity and dynamic environment. In addition, considering algorithm solvability and uniqueness, four constraints are proposed, which are force constraint, geometric constraint, normal vector constraint, and current mutation constraint. In order to solve conflict solution of algorithm in redundant constraints, compatibility solution analysis is proposed. Finally, a simulation experiment shows that the proposed method can achieve collision information efficiently and accurately.

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Peng, Gao Liang, Hong Liang, and Xin Li. "Meso-Scale Oriented Physical Simulation Model for Complex Product Maintenance in Virtual Environment." Advanced Materials Research 706-708 (June 2013): 1954–57. http://dx.doi.org/10.4028/www.scientific.net/amr.706-708.1954.

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Large component disassembly is complex tasks, the collision during the operation process often cause component damage and deform, even bring safe accident and result in significant loss. This paper proposes to use Meso-dimential oriented physical simulation strategy to research the collision effect simulation and damage surface visualization of large component during disassembly operation. Meso-collide behavior of multi-particles is adapted to simulate the macro-collision of large component. The method has important significance for expanding the mechanical simulation theory and solving the complex practical engineering problem.

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Popova, Anna M., Viacheslav V. Komarov, Hartmut Jungclas, Lothar Schmidt, and Alexander Zulauf. "Energy Exchange During Grazing Collision of Two Chain Molecules." Zeitschrift für Naturforschung A 65, no. 6-7 (July 1, 2010): 568–72. http://dx.doi.org/10.1515/zna-2010-6-713.

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A theoretical model is presented, which describes the collision of two polyatomic organic molecules grazing each other at relative velocities below Bohr velocity. If the interacting molecules contain chains of diatomic dipoles, each of these chains can acquire and accumulate IR energy quanta by transition into collective excited vibrational states (excimols) during the contact period (~10−12 s). The excimol energy transport from one of the chains to close trap-bonds (energy acceptors) of the molecule as well as the energy exchange processes between the two molecules can lead to their fragmentation or electronic excitation. The probability functions of all mentioned processes were derived and presented in analytical form.

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Cummins, Cloe, and Rhonda Orr. "Analysis of Physical Collisions in Elite National Rugby League Match Play." International Journal of Sports Physiology and Performance 10, no. 6 (September 2015): 732–39. http://dx.doi.org/10.1123/ijspp.2014-0541.

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Objective: To investigate the impact forces of collision events during both attack and defense in elite rugby league match play and to compare the collision profiles between playing positions. Participants: 26 elite rugby league players. Methods: Player collisions were recorded using an integrated accelerometer in global positioning system units (SPI-Pro X, GPSports). Impact forces of collisions in attack (hit-ups) and defense (tackles) were analyzed from 359 files from outside backs (n = 78), adjustables (n = 97), wide-running forwards (n = 136), and hit-up forwards (n = 48) over 1 National Rugby League season. Results: Hit-up forwards were involved in 0.8 collisions/min, significantly more than all other positional groups (wide-running forwards P = .050, adjustables P = .042, and outside backs P = .000). Outside backs experienced 25% fewer collisions per minute than hit-up forwards. Hit-up forwards experienced a collision within the 2 highest classifications of force (≥10 g) every 2.5 min of match play compared with 1 every 5 and 9 min for adjustables and outside backs, respectively. Hit-up forwards performed 0.5 tackles per minute of match play, 5 times that of outside backs (ES = 1.90; 95% CI [0.26,3.16]), and 0.2 hit-ups per minute of match play, twice as many as adjustables. Conclusions: During a rugby league match, players are exposed to a significant number of collision events. Positional differences exist, with hit-up and wide-running forwards experiencing greater collision events than adjustables and outside backs. Although these results may be unique to the individual team’s defensive- and attacking-play strategies, they are indicative of the significant collision profiles in professional rugby league.

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Макаров, Aleksey Makarov, Владимиров, Aleksandr Vladimirov, Сергиев, Arkadiy Sergiev, Швачкин, and Evgeniy Shvachkin. "PHYSICAL PRINCIPLES OF VIBRATION CUTTING IN TURNING." Bulletin of Belgorod State Technological University named after. V. G. Shukhov 2, no. 3 (April 4, 2017): 94–102. http://dx.doi.org/10.12737/24626.

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The vibrating cutting is one of the effective methods of processing workpieces of hard materials for the manufacture of parts of mining and metallurgical equipment. With proper selection of the vibration modes of cutting improves durability of the cutting tool and to ensure reliable chip control. When machining materials using a cutting tool vibration in the cutting area there are processes other than the processes occurring in the normal turning. A brief literature review of studies describing the processes occurring in the cutting zone. Particular attention is paid to the process and built-up edge is a schematic diagram of its occurrence and the removal from the surface of the cutting tool. The mechanism of the cutting edge wear, impact durability during the built-up edge on the tool and the machined surface roughness. A hypothesis to explain the physical processes of cutting vibration during turning. A scheme of the process of cutting vibration and formulated conditions for the formation of build-up and its subsequent removal from the tool tip.

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Myer, Gregory D. "A Promising New Protection Against Brain Injury During Collision Sport." Medicine & Science in Sports & Exercise 48 (May 2016): 628. http://dx.doi.org/10.1249/01.mss.0000486884.69736.d7.

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Shrivastava, Shamit, Kevin H. Kang, and Matthias F. Schneider. "Collision and annihilation of nonlinear sound waves and action potentials in interfaces." Journal of The Royal Society Interface 15, no. 143 (June 2018): 20170803. http://dx.doi.org/10.1098/rsif.2017.0803.

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Nerve impulses, previously proposed as manifestations of nonlinear acoustic pulses localized at the plasma membrane, can annihilate upon collision. However, whether annihilation of acoustic waves at interfaces takes place is unclear. We previously showed the propagation of nonlinear sound waves that propagate as solitary waves above a threshold (super-threshold) excitation in a lipid monolayer near a phase transition. Here we investigate the interaction of these waves. Sound waves were excited mechanically via a piezo cantilever in a lipid monolayer at the air–water interface and their amplitude is reported before and after a collision. The compression amplitude was observed via Förster resonance energy transfer between donor and acceptor dyes, measured at fixed points along the propagation path in the lipid monolayer. We provide direct experimental evidence for the annihilation of two super-threshold interfacial pulses upon head-on collision in a lipid monolayer and conclude that sound waves propagating in a lipid interface can interact linearly, nonlinearly, or annihilate upon collision depending on the state of the system. Thus we show that the main characteristics of nerve impulses, i.e. solitary character, velocity, couplings, all-or-none behaviour, threshold and even annihilation are also demonstrated by nonlinear sound waves in a lipid monolayer, where they follow directly from the thermodynamic principles applied to an interface. As these principles are equally unavoidable in a nerve membrane, our observations strongly suggest that the underlying physical basis of action potentials and the observed nonlinear-pules is identical.

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Arif Pratiwindyo. "The T.R.E.E Principles." Ideguru: Jurnal Karya Ilmiah Guru 4, no. 1 (October 1, 2019): 22–34. http://dx.doi.org/10.51169/ideguru.v4i1.79.

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Health and Physical Education (HPE) is one of the lesson which become part of the integral in total education in order to develop physical fitness, social mental,also emotional as well in order to create Indonesian people completely through physical activity’s vehicle as a shape from interaction’s process among learners with sphere through physical activitis that arranged systematically. So that HPE has it’s roles such as: life long education utility, life long health utility, life long skill utility. To solve various obstacles during learning HPE such as diversity in learner’s conditions, diversity of facilities and infrastructures, and also the condition of school’s environment we could apply The T.R.E.E. Principles that stand for Teaching Styles, Rules and Regulations, Environments, and Equipments.

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Mishina, I. E., A. M. Sarana, T. V. Mikhailovskaia, and G. E. Ivanova. "Principles for the appointment of aerobic physical training during outpatient cardiac rehabilitation." Bulletin of Restorative Medicine 97, no. 3 (June 28, 2020): 83–95. http://dx.doi.org/10.38025/2078-1962-2020-97-3-83-95.

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Cardiorehabilitation is a fundamental component of the secondary prevention of cardiovascular disease in patients with acute cardiovascular disease. The article considers the main goals, components, rules of selection and control of intensity and safety of physical training programs during ambulatory cardiorehabilitation.

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Howell, David R., Scott Laker, Michael W. Kirkwood, and Julie Wilson. "CONTACT AND COLLISION SPORTS PARTICIPATION DURING ADOLESCENCE IS ASSOCIATED WITH REDUCED ANXIETY AND DEPRESSIVE SYMPTOMS." Orthopaedic Journal of Sports Medicine 8, no. 4_suppl3 (April 1, 2020): 2325967120S0016. http://dx.doi.org/10.1177/2325967120s00169.

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Background: Recently, participation in contact and/or collision youth sports has received attention due to concern over exposure to repetitive head impacts. However, few studies have examined the relative risks and benefits of participation in contact and/or collision sports among young athletes currently engaged in these sports. Purposes and Hypotheses: We sought to examine whether participation in contact and/or collision sports during adolescence would be associated with quality of life (QOL) among a sample of healthy adolescent athletes undergoing a pre-participation examination. We hypothesized QOL domains scores would be similar between contact/collision and no/limited contact sport athletes. Methods: We conducted a cross-sectional study of adolescent athletes undergoing a pre-participation physical examination. During the assessment, participants completed a sport participation questionnaire and the Patient-Reported Outcomes Measurement Information System (PROMIS) Pediatric-25 Profile, a measure of health-related quality of life. We grouped patients based on reported organized contact/collision or limited/non-contact sports participation in the past year, as delineated by Rice (2008). We compared PROMIS domain scores between groups using Mann-Whitney U tests, and used multivariable linear regression to identify the association between PROMIS domains scores and contact/collision sport participation while adjusting for covariates (sex, age, height, history of bone, muscle, ligament, or tendon injury, history of acute fracture or dislocation) in separate models. Results: A total of 281 adolescents participated: 143 (51%) reported contact or collision sport participation in the year prior to the study. There was a significantly greater proportion of females in the no/limited contact sport group compared to the contact/collision sport group (Table 1). There was a significantly greater proportion of contact/collision sport athletes who reported past bone, muscle, ligament, or tendon injuries and acute fracture or dislocation injuries compared to no/limited contact sport athletes (Table 1). Upon univariable comparison, those in the contact/collision sport group reported significantly lower anxiety and depressive symptom domain scores than the no/limited contact sport group (Table 2). After covariate adjustment, contact/collision sport participation was significantly associated with lower anxiety and depressive symptom domain scores (Table 3). Conclusion: Adolescents participating in organized contact/collision sports reported lower anxiety and depressive symptoms than adolescents participating in no/limited contact sports. These results reinforce the need to re-examine assumptions that youth contact/collision sports are necessarily associated with negative quality of life. Future prospective studies will be required to better understand any causal relationship between contact sports and psychological well-being in young athletes, both in the short- and long-term. [Table: see text][Table: see text][Table: see text]

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Wang, Li-I., Chin-Yi Gu, I.-Lin Wang, Sheng-Wun Siao, and Szu-Ting Chen. "The collision forces and lower-extremity inter-joint coordination during running." Sports Biomechanics 17, no. 2 (February 28, 2017): 143–56. http://dx.doi.org/10.1080/14763141.2016.1249938.

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Kolesnikova, G. P. "Material point physical model rationale while studying kinematic characteristics of a motor vehicle in case of oblique collision with side cable barriers." Advanced Engineering Research 21, no. 1 (April 4, 2021): 32–42. http://dx.doi.org/10.23947/2687-1653-2021-21-1-32-42.

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Introduction. A review of the application of theoretical mechanics methods for the development of algorithms of approximate analytical simulation of a motor vehicle (MV) movement in case of oblique collision with side cable barriers is performed. The representation of the MV as a material point in this type of collision is validated. The study objective is to demonstrate the application of a physical model of a material point to describe the motor vehicle dynamics in the event of its oblique collision with side cable barrier.Materials and Methods. A new physical model that describes the opposition to the motor vehicle movement from the side of a cable barrier in an oblique collision is proposed. New methods of approximate analytical construction of the MV movements during an oblique collision with the side cable barriers are presented. The analytical calculation results are verified by the data of the finite element (FE) simulation of the collision according to the data of field tests. The FE simulation was carried out using a multi-purpose finite element complex LS-Dyna.Results. New analytical algorithms have been developed for the MV movement in case of an oblique collision with side cable barriers, as well as a new physical model describing the opposition to the MV movement from the side of cable barriers. The application of a physical model of a material point to study the motor vehicle dynamics during an oblique collision with side cable barriers is established scientifically, including the comparative analysis of the kinematic results of the virtual test with kinematic calculations obtained on the basis of algorithms for analytical construction of the MV movements.Discussion and Conclusions. The analysis of the kinematic results of the virtual test in comparison with the analytical kinematic calculations has shown that the representation of a motor vehicle as a material point in case of an oblique collision with side cable barriers is reasonable since the MV movement is close to translational motion. The results obtained can be used in the development and analysis of the correctness of the FE modeling of a side collision of a motor vehicle with cable barriers.

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Wilson, Perry B. "Electron Linacs for High Energy Physics." Reviews of Accelerator Science and Technology 01, no. 01 (January 2008): 7–41. http://dx.doi.org/10.1142/s1793626808000034.

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The purpose of this article is to introduce some of the basic physical principles underlying the operation of electron linear accelerators (electron linacs). Electron linacs have applications ranging from linacs with an energy of a few MeV, such that the electrons are approximately relativistic, to future electron–positron linear colliders having a collision energy in the several-TeV energy range. For the most part, only the main accelerating linac is treated in this article.

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Leggett, Graham J., David Briggs, and John C. Vickerman. "Collision target-gas effects during the tandem secondary-ion mass-spectrometric analysis of polymers." Journal of the Chemical Society, Faraday Transactions 86, no. 10 (1990): 1863. http://dx.doi.org/10.1039/ft9908601863.

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McArthur, Amanda. "Pain and the collision of expertise in primary care physical exams." Discourse Studies 21, no. 5 (May 19, 2019): 522–39. http://dx.doi.org/10.1177/1461445619846707.

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Using conversation analysis and a collection of naturally occurring US primary care consultations, this article explores the search for pain during primary care physical exams. Inhabiting this activity is a ‘collision’ of expertise between physicians’ clinical knowledge about bodies and patients’ knowledge about their bodies. I show how patients responding to questions like does that hurt? tacitly guide physicians to their pain using pain displays, glottal cutoffs and response delays to observably react to the physician’s touch, delineating painful from non- or less-painful areas. Physicians respond to these practices by altering the trajectory of their touch in coordination with the patient’s embodied behavior. In this local context, physicians’ touch not only constrains patients to (dis)affirm pain in a particular location, but it is also a unique affordance for patients to guide physicians while nonetheless preserving the physician’s authority over where to test for pain, thereby maintaining the physical examination activity framework.

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Prabowo, Aditya Rio, Jung Min Sohn, Dong Myung Bae, and Joung Hyung Cho. "Performance assessment on a variety of double side structure during collision interaction with other ship." Curved and Layered Structures 4, no. 1 (September 26, 2017): 255–71. http://dx.doi.org/10.1515/cls-2017-0017.

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Abstract The main goal of the present paper was to study the physical response of a double side skin (DSS) structure under impact load in a collision event between two ships. Collision energy and damage extent (size and location) during the collision process were observed together with damage patterns on side structure. The ships were modeled after a Ro-Ro passenger ship and cargo reefer which were involved in a ship collision on the Sunda Strait while the analyseswere performed using non-linear simulations FEMto produce virtual simulation data. Several caseswere proposed to be investigated in this work with involvement of parameters i.e. penetration location and ship materials which were embedded on the structure model. A series of material experiments and testing was conducted to obtain detailed material properties which were to be deployed in simulation. It was shown that, after penetration at the transition location, the striking ship was successfully deforming and forming tears to the inner skin. On the other hand, with identical structure and identical mass of construction, the use of high-strength low-alloy (HSLA) steel as the repair material offered considerably better capacity in absorbing the impact load than plain-carbon steel.

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XU, TIAN, JIZHUANG FAN, QIANQIAN FANG, JIE ZHAO, and YANHE ZHU. "ROBOTIC ARM COLLISION REACTION STRATEGIES FOR SAFE HUMAN–ROBOT INTERACTION WITHOUT TORQUE SENSORS." Journal of Mechanics in Medicine and Biology 19, no. 07 (November 2019): 1940034. http://dx.doi.org/10.1142/s0219519419400347.

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Three kinds of collision reaction strategies for increasing safety during human and robot interactions without relying on torque sensors are proposed in this paper. In the proposed algorithms, motor torque is estimated by driver current. The generalized momentum observer is used for collision detection, which does not need joints acceleration information and calculates the inverse of the inertia matrix. Three different collision reaction strategies, going away, dragging by hands and mechanical impedance developed in this paper, aim to enhance safety to humans during physical interaction with robots. For verifying the efficiency of the proposed algorithms, experiments are tested between a 1-DOF manipulator system and a human being. At last, the experiments’ results show that the proposed collision reaction algorithms are effective.

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Perozo, Eduardo, Anna Kloda, D. Marien Cortes, and Boris Martinac. "Physical principles underlying the transduction of bilayer deformation forces during mechanosensitive channel gating." Nature Structural Biology 9, no. 9 (August 12, 2002): 696–703. http://dx.doi.org/10.1038/nsb827.

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MÜLLER, BERNDT, and ANDREAS SCHÄFER. "ENTROPY CREATION IN RELATIVISTIC HEAVY ION COLLISIONS." International Journal of Modern Physics E 20, no. 11 (November 2011): 2235–67. http://dx.doi.org/10.1142/s0218301311020459.

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We review current ideas on entropy production during the different stages of a relativistic nuclear collision. This includes recent results on decoherence entropy and the entropy produced during the hydrodynamic phase by viscous effects. We start by a discussion of decoherence caused by gluon bremsstrahlung in the very first interactions of gluons from the colliding nuclei. We then present a general framework, based on the Husimi distribution function, for the calculation of entropy growth in quantum field theories, which is applicable to the early ("glasma") phase of the collision during which most of the entropy is generated. The entropy calculated from the Husimi distribution exhibits linear growth when the quantum field contains unstable modes and the growth rate is asymptotically equal to the Kolmogorov–Sinaï entropy. We outline how the approach can be used to investigate the problem of entropy production in a relativistic heavy ion reaction from first principles. We show that the same result can be obtained in the framework of a completely different approach called eigenstate thermalization hypothesis. Finally we discuss some recent results on entropy production in the strong coupling limit, as obtained from AdS/CFT duality.

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Lee, David V., John E. A. Bertram, Jennifer T. Anttonen, Ivo G. Ros, Sarah L. Harris, and Andrew A. Biewener. "A collisional perspective on quadrupedal gait dynamics." Journal of The Royal Society Interface 8, no. 63 (April 6, 2011): 1480–86. http://dx.doi.org/10.1098/rsif.2011.0019.

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The analysis of terrestrial locomotion over the past half century has focused largely on strategies of mechanical energy recovery used during walking and running. In contrast, we describe the underlying mechanics of legged locomotion as a collision-like interaction that redirects the centre of mass (CoM). We introduce the collision angle, determined by the angle between the CoM force and velocity vectors, and show by computing the collision fraction, a ratio of actual to potential collision, that the quadrupedal walk and gallop employ collision-reduction strategies while the trot permits greater collisions. We provide the first experimental evidence that a collision-based approach can differentiate quadrupedal gaits and quantify interspecific differences. Furthermore, we show that this approach explains the physical basis of a commonly used locomotion metric, the mechanical cost of transport. Collision angle and collision fraction provide a unifying analysis of legged locomotion which can be applied broadly across animal size, leg number and gait.

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McLellan, Christopher P., and Dale I. Lovell. "Neuromuscular Responses to Impact and Collision During Elite Rugby League Match Play." Journal of Strength and Conditioning Research 26, no. 5 (May 2012): 1431–40. http://dx.doi.org/10.1519/jsc.0b013e318231a627.

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MacLeod, Simon J., Chris Hagan, Mikel Egaña, Jonny Davis, and David Drake. "The Use of Microtechnology to Monitor Collision Performance in Professional Rugby Union." International Journal of Sports Physiology and Performance 13, no. 8 (September 1, 2018): 1075–82. http://dx.doi.org/10.1123/ijspp.2017-0124.

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Purpose: To determine if microtechnology-derived collision loads discriminate between collision performance and compare the physical and analytical components of collision performance between positional groups. Methods: Thirty-seven professional male rugby union players participated in this study. Collision events from 11 competitive matches were coded using specific tackle and carry classifications based on the ball-carrier’s collision outcome. Collisions were automatically detected using 10 Hz microtechnology units. Collision events were identified, coded (as tackle or carry), and timestamped at the collision contact point using game analysis software. Attacking and defensive performances of 1609 collision events were analyzed. Results: Collision loads were significantly greater during dominant compared with neutral and passive collisions (P < .001; effect size [ES] = 0.53 and 0.80, respectively), tackles (P < .0001; ES = 0.60 and 0.56, respectively), and carries (P < .001; ES = 0.48 and 0.79, respectively). Overall, forwards reported a greater number and frequency of collisions but lower loads per collision and velocities at collision point than did backs. Microtechnology devices can also accurately, sensitively, and specifically identify collision events (93.3%, 93.8%, and 92.8%, respectively). Conclusion: Microtechnology is a valid means of discriminating between tackle and carry performance. Thus, microtechnology-derived collision load data can be utilized to track and monitor collision events in training and games.

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Shakeel, Atif, Riaz Hussain, Adeel Iqbal, Irfan Latif Khan, Qadeer Ul Hasan, and Shahzad Ali Malik. "Spectrum Handoff based on Imperfect Channel State Prediction Probabilities with Collision Reduction in Cognitive Radio Ad Hoc Networks." Sensors 19, no. 21 (October 31, 2019): 4741. http://dx.doi.org/10.3390/s19214741.

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The spectrum handoff is highly critical as well as challenging in a cognitive radio ad hoc network (CRAHN) due to lack of coordination among secondary users (SUs), which leads to collisions among the SUs and consequently affects the performance of the network in terms of spectrum utilization and throughput. The target channel selection mechanism as part of handoff process can play an enormously significant role in minimizing the collisions among the SUs and improving the performance of a cognitive radio network (CRN). In this paper, an enhanced target channel selection scheme based on imperfect channel state prediction is proposed for the spectrum handoff among the SUs in a CRAHN. The proposed scheme includes an improved frame structure that increases coordination among the SUs in the ad hoc environment and helps in organizing the SUs according to the shortest job first principle during channel access. Unlike the existing prediction-based spectrum handoff techniques, the proposed scheme takes into account the accuracy of channel state prediction; the SUs affected due to false prediction are compensated by allowing them to contend for channel access within the same transmission cycle and thus enabling them to achieve higher throughput. The proposed scheme has been compared with the contemporary spectrum handoff schemes and the results have demonstrated substantial improvement in throughput and extended data delivery time by virtue of the reduced number of collisions.

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Shin, Kim, Seo, and Rhim. "A Virtual Pressure and Force Sensor for Safety Evaluation in Collaboration Robot Application." Sensors 19, no. 19 (October 7, 2019): 4328. http://dx.doi.org/10.3390/s19194328.

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Recent developments in robotics have resulted in implementations that have drastically increased collaborative interactions between robots and humans. As robots have the potential to collide intentionally and/or unexpectedly with a human during the collaboration, effective measures to ensure human safety must be devised. In order to estimate the collision safety of a robot, this study proposes a virtual sensor based on an analytical contact model that accurately estimates the peak collision force and pressure as the robot moves along a pre-defined path, even before the occurrence of a collision event, with a short computation time. The estimated physical interaction values that would be caused by the (hypothetical) collision were compared to the collision safety thresholds provided within ISO/TS 15066 to evaluate the safety of the operation. In this virtual collision sensor model, the nonlinear physical characteristics and the effect of the contact surface shape were included to assure the reliability of the prediction. To verify the effectiveness of the virtual sensor model, the force and pressure estimated by the model were compared with various experimental results and the numerical results obtained from a finite element simulation.

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Shen, Haijun, and Miles A. Townsend. "Collisions of Constrained Rigid Body Systems with Friction." Shock and Vibration 5, no. 3 (1998): 141–51. http://dx.doi.org/10.1155/1998/602768.

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A new approach is developed for the general collision problem of two rigid body systems with constraints (e.g., articulated systems, such as massy linkages) in which the relative tangential velocity at the point of contact and the associated friction force can change direction during the collision. This is beyond the framework of conventional methods, which can give significant and very obvious errors for this problem, and both extends and consolidates recent work. A new parameterization and theory characterize if, when and how the relative tangential velocity changes direction during contact. Elastic and dissipative phenomena and different values for static and kinetic friction coefficients are included. The method is based on the explicitly physical analysis of events at the point of contact. Using this method, Example 1 resolves (and corrects) a paradox (in the literature) of the collision of a double pendulum with the ground. The method fundamentally subsumes other recent models and the collision of rigid bodies; it yields the same results as conventional methods when they would apply (Example 2). The new method reformulates and extends recent approaches in a completely physical context.

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Baldwin, Carryl L. "Verbal collision avoidance messages during simulated driving: perceived urgency, alerting effectiveness and annoyance." Ergonomics 54, no. 4 (April 2011): 328–37. http://dx.doi.org/10.1080/00140139.2011.558634.

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Wundersitz, Daniel W. T., Paul B. Gastin, Samuel J. Robertson, and Kevin J. Netto. "Validity of a Trunk-Mounted Accelerometer to Measure Physical Collisions in Contact Sports." International Journal of Sports Physiology and Performance 10, no. 6 (September 2015): 681–86. http://dx.doi.org/10.1123/ijspp.2014-0381.

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Context: Accelerometer peak impact accelerations are being used to measure player physical demands in contact sports. However, their accuracy to do so has not been ascertained. Purpose: To compare peak-impact-acceleration data from an accelerometer contained in a wearable tracking device with a 3-dimensional motion-analysis (MA) system during tackling and bumping. Methods: Twenty-five semielite rugby athletes wore a tracking device containing a 100-Hz triaxial accelerometer (MinimaxX S4, Catapult Innovations, Australia). A single retroreflective marker was attached to the device, with its position recorded by a 12-camera MA system during 3 physical-collision tasks (tackle bag, bump pad, and tackle drill; N = 625). The accuracy, effect size, agreement, precision, and relative errors for each comparison were obtained as measures of accelerometer validity. Results: Physical-collision peak impact accelerations recorded by the accelerometer overestimated (mean bias 0.60 g) those recorded by the MA system (P < .01). Filtering the raw data at a 20-Hz cutoff improved the accelerometer’s relationship with MA data (mean bias 0.01 g; P > .05). When considering the data in 9 magnitude bands, the strongest relationship with the MA system was found in the 3.0-g or less band, and the precision of the accelerometer tended to reduce as the magnitude of impact acceleration increased. Of the 3 movements performed, the tackle-bag task displayed the greatest validity with MA. Conclusions: The findings indicate that the MinimaxX S4 accelerometer can accurately measure physical-collision peak impact accelerations when data are filtered at a 20-Hz cutoff frequency. As a result, accelerometers may be useful to measure physical collisions in contact sports.

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Yap, Li-Wei, and Robert G. Endres. "A model of cell-wall dynamics during sporulation inBacillus subtilis." Soft Matter 13, no. 44 (2017): 8089–95. http://dx.doi.org/10.1039/c7sm00818j.

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Schmidt, David P., and Christopher J. Rutland. "Reducing Grid Dependency in Droplet Collision Modeling." Journal of Engineering for Gas Turbines and Power 126, no. 2 (April 1, 2004): 227–33. http://dx.doi.org/10.1115/1.1564066.

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Droplet collision models have been criticized for creating large mesh dependency in spray calculations. These numerical errors are very troublesome; they behave erratically and interfere with the predictive ability of physical models. The collision method used in KIVA can cause mesh dependent changes in average drop size of over 40 microns. In order to reduce mesh dependency, a new method has been developed for calculating the incidence of collision. The solution is to create a special collision mesh that is optimized for accuracy. The mesh is created automatically during the spray calculation. Additionally, a different stochastic collision sampling technique is also used. The new method, called the NTC algorithm, was incorporated into KIVA and found to be much faster than older algorithms. Calculations with 60,000 parcels required only a few CPU minutes. With the new NTC method and collision mesh, the mesh dependence of the drop size is only nine microns. This remaining mesh dependency is found to be due to the drag calculations and is not the fault of the collision algorithm.

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Song, Lifei, Houjing Chen, Wenhao Xiong, Zaopeng Dong, Puxiu Mao, Zuquan Xiang, and Kai Hu. "Method of Emergency Collision Avoidance for Unmanned Surface Vehicle (USV) Based on Motion Ability Database." Polish Maritime Research 26, no. 2 (June 1, 2019): 55–67. http://dx.doi.org/10.2478/pomr-2019-0025.

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Abstract The unmanned surface vehicles (USV) are required to perform a dynamic obstacle avoidance during fulfilling a task. This is essential for USV safety in case of an emergency and such action has been proved to be difficult. However, little research has been done in this area. This study proposes an emergency collision avoidance algorithm for unmanned surface vehicles (USVs) based on a motion ability database. The algorithm is aimed to address the inconsistency of the existing algorithm. It is proposed to avoid collision in emergency situations by sharp turning and treating the collision avoidance process as a part of the turning movement of USV. In addition, the rolling safety and effect of speed reduction during the collision avoidance process are considered. First, a USV motion ability database is established by numerical simulation. The database includes maximum rolling angle, velocity vector, position scalar, and steering time data during the turning process. In emergency collision avoidance planning, the expected steering angle is obtained based on the International Regulations for Preventing Collisions at Sea (COLREGs), and the solution space, with initial velocity and rudder angle taken as independent variables, is determined by combining the steering time and rolling angle data. On the basis of this solution space, the objective function is solved by the particle swarm optimization (PSO) algorithm, and the optimal initial velocity and rudder angle are obtained. The position data corresponding to this solution is the emergency collision avoidance trajectory. Then, the collision avoidance parameters were calculated based on the afore mentioned model of motion. With the use of MATLAB and Unity software, a semi-physical simulation platform was established to perform the avoidance simulation experiment under emergency situation. Results show the validity of the algorithm. Hence results of this research can be useful for performing intelligent collision avoidance operations of USV and other autonomous ships

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Howell, David R., Michael W. Kirkwood, Scott Laker, and Julie C. Wilson. "Collision and Contact Sport Participation and Quality of Life Among Adolescent Athletes." Journal of Athletic Training 55, no. 11 (October 29, 2020): 1174–80. http://dx.doi.org/10.4085/1062-6050-0536.19.

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Context Researchers investigating collision and contact sport participation during high school have found mixed results. Understanding the association between current contact and collision sport participation and quality-of-life outcomes can enhance our knowledge about the risks and benefits of sport participation. Objective To examine quality-of-life outcomes among high school athletes who reported participation in collision and contact sports in the year preceding assessment compared with no- or limited-contact sport athletes. Design Cross-sectional study. Setting Preparticipation physical examination. Patients or Other Participants High school athletes 13 to 18 years of age. Main Outcome Measure(s) We obtained sport participation and Patient-Reported Outcomes Measurement Information System (PROMIS) Pediatric-25 outcomes, which assess self-reported, quality-of-life domains in the preceding 7 days (ie, state assessment). Our grouping variable was collision and contact versus no- or limited-contact sport participation during the year preceding assessment. We used multivariable linear regression models to identify the associations between PROMIS scores and collision and contact sport participation and adjusted for sex; age; history of bone, muscle, ligament, or tendon injury; history of acute fracture or dislocation; and history of concussion. Results A total of 143 (51%) athletes reported collision and contact sport participation (24% female, mean age = 15.1 ± 1.7 years) and 138 (49%) reported no- or limited-contact sport participation (66% female, mean age = 15.4 ± 1.2 years). A higher proportion of collision and contact sport athletes reported a history of time loss for bone, muscle, ligament, and tendon injuries (51% versus 29%, P < .001) and for acute fracture or dislocation (46% versus 26%, P < .001) than did no- or limited-contact athletes. After adjusting for covariates, we found that collision and contact sport participation was significantly associated with lower state anxiety (β = −1.072, 95% confidence interval = −1.834, −0.310, P = .006) and depressive (β = −0.807, 95% confidence interval = −1.484, −0.130, P = .020) symptom scores. Conclusions Collision and contact sport athletes reported fewer anxiety and depressive symptoms in the week preceding evaluation than did no- or limited-contact sport athletes, but they had more extensive orthopaedic injury histories. Potential benefits and risks are associated with collision and contact sport participation. These data reinforce the need to examine the assumption that youth collision and contact sports are associated with negative quality of life.

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Terbeck, Sylvia, Jaysan Charlesford, Heather Clemans, Emily Pope, Aimee Lee, Joshua Turner, Michaela Gummerum, and Bettina Bussmann. "Physical Presence during Moral Action in Immersive Virtual Reality." International Journal of Environmental Research and Public Health 18, no. 15 (July 29, 2021): 8039. http://dx.doi.org/10.3390/ijerph18158039.

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Research on morality has focused on differences in moral judgment and action. In this study, we investigated self-reported moral reasoning after a hypothetical moral dilemma was presented on paper, and moral reasoning after that very same dilemma was experienced in immersive virtual reality (IVR). We asked open-ended questions and used content analysis to determine moral reasoning in a sample of 107 participants. We found that participants referred significantly more often to abstract principles and consequences for themselves (i.e., it is against the law) after the paper-based moral dilemma compared to the IVR dilemma. In IVR participants significantly more often referred to the consequences for the people involved in the dilemma (i.e., not wanting to hurt that particular person). This supports the separate process theory, suggesting that decision and action might be different moral concepts with different foci regarding moral reasoning. Using simulated moral scenarios thus seems essential as it illustrates possible mechanisms of empathy and altruism being more relevant for moral actions especially given the physical presence of virtual humans in IVR.

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Li, Zhijing, Jinhua Ye, and Haibin Wu. "A Virtual Sensor for Collision Detection and Distinction with Conventional Industrial Robots." Sensors 19, no. 10 (May 23, 2019): 2368. http://dx.doi.org/10.3390/s19102368.

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Physical contact inevitably occurs during robot interaction with outside environments. A robot should have the ability to detect and distinguish whether a physical interaction between a human and the robot is contact or collision, so as to ensure human safety and improve interaction performance. In this paper, a virtual sensor that can detect and distinguish contact and collision between humans and industrial robots is proposed. Based on the generalized momentum of the robot, two observers with low-pass and band-pass filter characteristics were designed in this virtual sensor to realize the robot collision detection. Using the different frequency distribution ranges of the lighter contact force signal and the heavier collision force signal, the filter parameters in the two observers were appropriately selected to distinguish between collisions and contacts in close interaction between humans and robots. The virtual sensor does not require acceleration information or inverse dynamics calculations. It only needs to sample the motor driving current and position information of the robot joint, and can easily be applied to conventional industrial robots. The experimental results show that the low-pass and band-pass torque observers can detect different force signals in real-time, and the proposed virtual sensor can be used for collision detection and distinction in human–robot interactions.

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McLellan, Christopher P., Dale I. Lovell, and Gregory C. Gass. "Biochemical and Endocrine Responses to Impact and Collision During Elite Rugby League Match Play." Journal of Strength and Conditioning Research 25, no. 6 (June 2011): 1553–62. http://dx.doi.org/10.1519/jsc.0b013e3181db9bdd.

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Van Stipdonk, Michael J., Winnie Chien, Victor Anbalagan, Garold L. Gresham, and Gary S. Groenewold. "Oxidation of 2-propanol ligands during collision-induced dissociation of a gas-phase uranyl complex." International Journal of Mass Spectrometry 237, no. 2-3 (October 2004): 175–83. http://dx.doi.org/10.1016/j.ijms.2004.07.007.

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Kimura, Akira. "Effect of Electric-Stimulation Alert Device for Object Collision Avoidance During Walking of People With Blindness." Archives of Physical Medicine and Rehabilitation 99, no. 10 (October 2018): e48-e49. http://dx.doi.org/10.1016/j.apmr.2018.07.170.

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Miles, Melvin H., Benjamin F. Bush, and David E. Stilwell. "Calorimetric Principles and Problems in Measurements of Excess Power during Pd-D2O Electrolysis." Journal of Physical Chemistry 98, no. 7 (February 1994): 1948–52. http://dx.doi.org/10.1021/j100058a038.

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Wang, Yu, and Matthew T. Mason. "Two-Dimensional Rigid-Body Collisions With Friction." Journal of Applied Mechanics 59, no. 3 (September 1, 1992): 635–42. http://dx.doi.org/10.1115/1.2893771.

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This paper presents an analysis of a two-dimensional rigid-body collision with dry friction. We use Routh’s graphical method to describe an impact process and to determine the frictional impulse. We classify the possible modes of impact, and derive analytical expressions for impulse, using both Poisson’s and Newton’s models of restitution. We also address a new class of impacts, tangential impact, with zero initial approach velocity. Some methods for rigid-body impact violate energy conservation principles, yielding solutions that increase system energy during an impact. To avoid such anomalies, we show that Poisson’s hypothesis should be used, rather than Newton’s law of restitution. In addition, correct identification of the contact mode of impact is essential.

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Uchida, Thomas K., Michael A. Sherman, and Scott L. Delp. "Making a meaningful impact: modelling simultaneous frictional collisions in spatial multibody systems." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 471, no. 2177 (May 2015): 20140859. http://dx.doi.org/10.1098/rspa.2014.0859.

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Impacts are instantaneous, computationally efficient approximations of collisions. Current impact models sacrifice important physical principles to achieve that efficiency, yielding qualitative and quantitative errors when applied to simultaneous impacts in spatial multibody systems. We present a new impact model that produces behaviour similar to that of a detailed compliant contact model, while retaining the efficiency of an instantaneous method. In our model, time and configuration are fixed, but the impact is resolved into distinct compression and expansion phases, themselves comprising sliding and rolling intervals. A constrained optimization problem is solved for each interval to compute incremental impulses while respecting physical laws and principles of contact mechanics. We present the mathematical model, algorithms for its practical implementation, and examples that demonstrate its effectiveness. In collisions involving materials of various stiffnesses, our model can be more than 20 times faster than integrating through the collision using a compliant contact model. This work extends the use of instantaneous impact models to scientific and engineering applications with strict accuracy requirements, where compliant contact models would otherwise be required. An open-source implementation is available in Simbody, a C++ multibody dynamics library widely used in biomechanical and robotic applications.

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Korolyova, N. "ORGANIZATIONAL AND METHODOLOGICAL PRINCIPLES OF USING MOBILE GAMES DURING STUDENTS’ STUDIES IN THE DISCIPLINE “PHYSICAL EDUCATION”." Pedagogy of the formation of a creative person in higher and secondary schools 2, no. 70 (2020): 170–73. http://dx.doi.org/10.32840/1992-5786.2020.70-2.32.

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Zhang, Yonggang. "Refection on the development of online physical education during the epidemic." Lifelong Education 9, no. 6 (September 28, 2020): 219. http://dx.doi.org/10.18282/le.v9i6.1346.

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In the past few months, the sudden outbreak of new coronary pneumonia disrupted our normal study and life. However, in order not to affect the progress of students’ learning, various schools have carried out online education and carried out non-stop teaching. Online teaching has become the norm in recent months. This teaching method has caught teachers, students, and parents a little bit off guard. However, as time goes by, everyone is becoming more and more familiar with this method. There are still some problems in teaching. This article analyzes the teaching characteristics of online physical education during the prevention and control of the new coronavirus epidemic, as well as the teaching principles of online physical education and the current status of online physical education. The online teaching strategy puts forward several aspects and directions for online physical education to be improved in the future.

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Lazarevic, Zorica, Gregor Krizan, Janez Krizan, Aleksandra Milutinovic, Martina Gilic, Izabela Kuryliszyn-Kudelska, and Nebojsa Romcevic. "Spectroscopic characterization of LiFePO4 as cathode material for Li-ion battery prepared in the pulse thermo-acoustic reactor." Science of Sintering 51, no. 3 (2019): 309–18. http://dx.doi.org/10.2298/sos1903309l.

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Lithium iron phosphate (LiFePO4) is a cathode material for the rechargeable-lithium batteries. In this paper is presented a novel method of fabrication carbon-coated LiFePO4 in a pilot reactor built according to the principles of the thermo-acoustic burner of Helmholtz-type. Crystalline powder with a high percentage of LiFePO4 was synthesized by incomplete combustion, i.e. in the reductive atmosphere, and calcined at 700?C for 6 h. The obtained samples were characterized by X-ray diffraction, IR and Raman spectroscopy. The aim of this study was to demonstrate the production of the high-quality lithium-ion cathode material by the incomplete combustion. The synthesis of LiFePO4 is completed during calcination and an ordered structure is attained. Fast synthesis in the reactor (less than 2 s) is achieved due to the reduction in the size of reactant's particles and a huge number of collisions owing to their strong turbulent flow associated with explosive combustion.

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Neunzert, Helmut, and Jens Struckmeier. "Particle Methods for the Boltzmann Equation." Acta Numerica 4 (January 1995): 417–57. http://dx.doi.org/10.1017/s0962492900002579.

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In the following chapters we will discuss particle methods for the numerical simulation of rarefied gas flows.We will mainly treat a billiard game, that is, our particles will be hard spheres. But we will also touch upon cases where particles have internal energies due to rotation or vibration, which they exchange in a collision, and we will talk about chemical reactions happening during a collision.Due to the limited size of this paper, we are only able to mention the principles of these real-gas effects. On the other hand, the general concepts of particle methods to be presented may be used for other kinds of kinetic equations, such as the semiconductor device simulation. We leave this part of the research to subsequent papers.

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Ščerba, Filip. "The Concept of Plea Bargaining Under the Czech Criminal Law and the Criminal Law of Other Countries Within the Region of Central Europe." International and Comparative Law Review 13, no. 1 (June 1, 2013): 7–22. http://dx.doi.org/10.1515/iclr-2016-0055.

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Abstract The article deals with the specific instrument used in criminal proceedings called as plea bargaining, or agreement upon the guilt and punishment (in the Czech legal regulation). This instrument is considered as one of the main measures used for acceleration of criminal proceedings and for criminal justice rationalization. Plea bargaining originally belongs to the system of criminal law in the countries belonging to the Anglo-Saxon legal order, but it has been implemented also into the legal orders of countries in Middle Europe region during last decade. Such implementation in connected with some important problems related to the different characteristics of criminal proceedings. The article solves some of these problems, primarily the collision with the basic principles of continental system of criminal law.

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Jiang, Hongyan, Marvin Kammler, Feizhi Ding, Yvonne Dorenkamp, Frederick R. Manby, Alec M. Wodtke, Thomas F. Miller, Alexander Kandratsenka, and Oliver Bünermann. "Imaging covalent bond formation by H atom scattering from graphene." Science 364, no. 6438 (April 25, 2019): 379–82. http://dx.doi.org/10.1126/science.aaw6378.

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Viewing the atomic-scale motion and energy dissipation pathways involved in forming a covalent bond is a longstanding challenge for chemistry. We performed scattering experiments of H atoms from graphene and observed a bimodal translational energy loss distribution. Using accurate first-principles dynamics simulations, we show that the quasi-elastic channel involves scattering through the physisorption well where collision sites are near the centers of the six-membered C-rings. The second channel results from transient C–H bond formation, where H atoms lose 1 to 2 electron volts of energy within a 10-femtosecond interaction time. This remarkably rapid form of intramolecular vibrational relaxation results from the C atom’s rehybridization during bond formation and is responsible for an unexpectedly high sticking probability of H on graphene.

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Journal articles on the topic 'Physical principles during collision'

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