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This paper is concerned with the existence of solutions of a class of Cauchy problems for hyperbolic partial fractional differential inclusions (HPFD) involving the Caputo fractional derivative with an impulse whose right hand side is convex and non-convex valued. Our results are achieved within the framework of the nonlinear alternative of Leray-Schauder type and contraction multivalued maps. A detailed example was provided to support the theorem.

This paper is concerned with the existence of solutions for a nonlinear multi-term impulsive fractional $ q $-integro-difference equation with nonlocal boundary conditions. The appropriated fixed point theorems are applied to accomplish the existence and uniqueness results for the given problem. We demonstrate the application of the obtained results with the aid of examples.

The purpose of this study was to determine the usefulness of calculating jump take-off momentum in rugby league (RL) by exploring its relationship with sprint momentum, due to the latter being an important attribute of this sport. Twenty-five male RL players performed 3 maximal-effort countermovement jumps on a force platform and 3 maximal effort 20-m sprints (with split times recorded). Jump take-off momentum and sprint momentum (between 0 and 5, 5 and 10, and 10 and 20 m) were calculated (mass multiplied by velocity) and their relationship determined. There was a very large positive relationship between both jump take-off and 0- to 5-m sprint momentum (r =.781, P <.001) and jump take-off and 5- to 10-m sprint momentum (r =.878, P <.001). There was a nearly perfect positive relationship between jump take-off and 10- to 20-m sprint momentum (r =.920, P <.001). Jump take-off and sprint momentum demonstrated good–excellent reliability and very large–nearly perfect associations (61%–85% common variance) in an RL cohort, enabling prediction equations to be created. Thus, it may be practically useful to calculate jump take-off momentum as part of routine countermovement jump testing of RL players and other collision-sport athletes to enable the indirect monitoring of sprint momentum. [ABSTRACT FROM AUTHOR]

Purpose: To examine correlations between peak force and impulse measures attained during the isometric midthigh pull (IMTP) and basketball-specific sprint and jump tests. Methods: Male, adolescent basketball players (N = 24) completed a battery of basketball-specific performance tests. Testing consisted of the IMTP (absolute and normalized peak force and impulse at 100 and 250 ms); 20-m sprint (time across 5, 10, and 20 m); countermovement jump (CMJ; absolute and normalized peak force and jump height); standing long jump (distance); and repeated lateral bound (distance). Correlation and regression analyses were conducted between IMTP measures and other attributes. Results: An almost perfect correlation was evident between absolute peak force attained during the IMTP and CMJ (r =.94, R2 = 56%, P <.05). Moderate to very large correlations (P <.05) were observed between IMTP normalized peak force and 5-m sprint time (r = −.44, R2 = 19%), 10-m sprint time (r = −.45, R2 = 20%), absolute (r =.57, R2 = 33%), normalized (r =.86, R2 = 73%) CMJ peak force, and standing long-jump distance (r =.51, R2 = 26%). Moderate to very large correlations were evident between impulse measures during the IMTP and 5-m sprint time (100 ms, r = −.40, R2 = 16%, P >.05) and CMJ absolute peak force (100 ms, r =.73, R2 = 54%; 250 ms, r =.68, R2 = 47%; P <.05). Conclusions: The IMTP may be used to assess maximal and rapid force expression important across a range of basketball-specific movements. [ABSTRACT FROM AUTHOR]

With force plates being widely implemented for neuromuscular performance assessment in sport-specific settings and various force-time metrics being able to differentiate athletes based on their performance capabilities, the purpose of the present study was to examine the differences in countermovement vertical jump (CVJ) characteristics between starting and non-starting professional male basketball players (e.g., ABA League). Twenty-three athletes (height = 199.2 ± 7.7 kg, body mass = 94.2 ± 8.2 kg, age = 23.8 ± 4.9 years) volunteered to participate in the present investigation. Upon completion of a standardized warm-up protocol, each athlete performed three maximal-effort CVJs without an arm swing while standing on a uni-axial force plate system sampling at 1,000 Hz. Independent t-tests were used to examine statistically significant differences (p

This paper generalizes Razumikhin-type theorem and Krasovskii stability theorem of impulsive stochastic delay systems. By proposing uniformly stable function (USF) in the form of impulse as a new tool, some properties about USF and some novel pth moment decay theorems are derived. Based on these new theorems, the stability theorems of impulsive stochastic linear delay system are acquired via the Razumikhin method and the Krasovskii method. The obtained results enhance the elasticity of the impulsive gain by comparing the previous results. Finally, numerical examples are given to demonstrate the effectiveness of theoretical results. [ABSTRACT FROM AUTHOR]

Under certain conditions, impulses, delays, and nonlocal conditions are known to be negligible in comparison with the duration of the process. From the practical (engineering) point of view, delays and nonlocal conditions are intrinsic phenomena of a system that do not violate certain properties of it, such as the controllability. In other words, as a rule, the controllability is robust under the influence of impulses, delays and nonlocal conditions. In this paper, we apply Rothe's fixed-point theorem to prove the interior approximate controllability of the semilinear heat equation with impulses, delays and nonlocal conditions. Also we obtain conditions under which the system considered is approximately controllable. [ABSTRACT FROM AUTHOR]

BACKGROUND: Neural stem cells are a group of cells that can self-proliferate and have multidirectional differentiation potential. In utero electroporation, which is the most direct and reliable method to study the development of cerebral cortex in vivo, can transduce RNA or plasmids into neural stem cells of mice to interfere with or overexpress target genes. OBJECTIVE: To optimize the conditions of in utero electroporation by targeting neural stem cells in the subependymal region of embryonic mice and using enhanced green fluorescent protein as the reporter gene, so as to provide an effective method for studying the development of cerebral cortex. METHODS: Adult ICR mice were mated at the ratio of one male to three female mice. The mice were caged at 8 p.m., and female mice with vaginal embolus were tested at 8 a.m. the next morning. The female mice with vaginal embolus were counted as 0.5-day pregnancy. On embryonic day 14 (E14), the pregnant mice were intraperitoneally anesthetized with ketamin (120 mg/kg) and xylazine (10 mg/kg). After shaving off the hair of the pregnant mouse’s abdomen and opening the abdominal cavity without cutting the pregnant mouse’s uterus, pEx-4-eGFP plasmid was transfected into neural stem cells of the subependymal region of fetal mice at different voltages using ECM803 electroporation transfection instrument and BTX electrode. After 3 days of transfection, the transfected mouse brain tissue was removed and frozen sections were performed to observe the expression of enhanced green fluorescent protein fluorescence on the cerebral cortex. The number of enhanced green fluorescent protein-positive cells was counted to evaluate the transfection efficiency. RESULTS AND CONCLUSION: (1) The survival and transfection effect of mice were different at 38, 40, 42, and 45 V. The mortality of fetal mice was less at 38 V, but the transfection efficiency was lower. Mice treated at 42 V survived and the fluorescence intensity of enhanced green fluorescent protein was higher in the brain tissue treated at 42 V than in the brain treated at 40 V. However, 45 V was more lethal to mice. Therefore, 42 V was a better transformation condition. (2) Under the condition of 42 V, enhanced green fluorescent protein positive cells were more and the fluorescence was brighter after the pulse was changed from 5 to 8. (3) The improved conditions had no effect on the growth of transfected cortical cells. [ABSTRACT FROM AUTHOR]

In this paper, we introduce and investigate a new class of nonlinear multi-term impulsive anti-periodic boundary value problems involving Caputo type fractional q -derivative operators of different orders and the Riemann–Liouville fractional q -integral operator. The uniqueness of solutions to the given problem is proved with the aid of Banach's fixed point theorem. Applying a Shaefer-like fixed point theorem, we also obtain an existence result for the problem at hand. Examples are constructed for illustrating the obtained results. The paper concludes with certain interesting observations concerning the reduction of the results proven in the paper to some new results under an appropriate choice of the parameters involved in the governing equation. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Central China Normal University is the property of Huazhong Normal University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper concerns a class of fractional impulsive neutral functional differential equations with an infinite delay driven by the Rosenblatt process. A set of sufficient conditions are established for the existence of new mild solutions using fixed point theory. Finally, an illustrative example is provided to demonstrate the applicability of the theoretical result. [ABSTRACT FROM AUTHOR]

Radar technology has the potential for providing new insights into maximal horizontal deceleration ability. This study aimed to investigate the intra- and inter-day reliability and sensitivity of kinematic and kinetic variables obtained from a novel, maximal horizontal deceleration test, using radar technology. Thirty-eight university sport athletes completed testing for intra-day analysis. Twelve of these participants also completed the deceleration test on a second day for inter-day analysis. The maximal horizontal deceleration test required participants to decelerate maximally following 20 m maximal horizontal sprint acceleration. Reliability was assessed using the intraclass correlation coefficient (ICC) and coefficient of variation (CV%). Sensitivity was evaluated by comparing typical error (TE) to the smallest worthwhile change (SWC). A number of kinematic and kinetic variables had good (ICC > 0.75, CV < 10%) overall intra-day reliability, and were sensitive to detect small-to-moderate changes in deceleration performance after a single familiarisation session. Only kinetic variables had good overall inter-day reliability and were sensitive to detect moderate changes in deceleration performance. The utilisation of this test protocol to assess maximal horizontal deceleration can provide new insights into individual maximal horizontal deceleration capabilities. Future work using this or similar approaches may provide insights into the neuromuscular performance qualities needed to decelerate maximally. [ABSTRACT FROM AUTHOR]

Epilepsy, a chronic neurological illness, takes a heavy emotional toll on patients and their families. It is one of most neglected neurological illnesses in Africa. Studies have shown that epileptic seizures may be managed pharmacologically, behaviorally, and nutritionally. This study aims to investigate the therapeutic potential of combination of curcumin and aerobic exercise in treatment of epileptic seizure in rats. Four groups of Wistar strain albino rats; control, pilocarpine, pilocarpine + curcumin, and pilocarpine + curcumin + exercise was investigated to determine the effects of oral administration of curcumin and treadmill exercise on seizure frequency, activities of monoamine oxidase (MAO) and acetylcholinesterase (AChE), redox markers and Brain-Derived Neurotrophic Factor (BDNF) mRNA expression level in brain cortex and hippocampus of pilocarpine-induced epileptic rats. The results showed a significant reduction in the seizure frequency of rats treated with curcumin and curcumin + exercise groups, when compared with the pilocarpine-induced group. In addition, the significantly elevated MAO and AChE activities were ameliorated, coupled with a significant reduction in reactive oxygen species and thiol contents of the brain tissues of the pilocarpine-induced rats treated with curcumin plus exercise. Furthermore, the downregulated BDNF mRNA expression levels were significantly ameliorated in the induced groups treated with curcumin plus exercise. This study therefore, suggests that treadmill exercise could improve the therapeutic effects of curcumin in the management of epileptic seizure. [ABSTRACT FROM AUTHOR]

This paper is concerned with the existence of solutions of a class of Cauchy problems for hyperbolic partial fractional differential inclusions (HPFD) involving the Caputo fractional derivative with an impulse whose right hand side is convex and non-convex valued. Our results are achieved within the framework of the nonlinear alternative of Leray-Schauder type and contraction multivalued maps. A detailed example was provided to support the theorem. [ABSTRACT FROM AUTHOR]

Copyright of Electronic Processing of Materials / Elektronnaya Obrabotka Materialov is the property of Institute of Applied Physics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of this study was to identify the relationship between dry-land and in-water strength with performance and kinematic variables in short-distance, middle-distance, and repeated sprint swimming. Fifteen competitive swimmers applied a bench press exercise to measure maximum strength (MS), maximum power (P), strength corresponding to P (F@P), maximum velocity (MV), and velocity corresponding to P (V@P) using F–V and P–V relationships. On a following day, swimmers performed a 10 s tethered swimming sprint (TF), and impulse was measured (IMP). On three separate days, swimmers performed (i) 50 and 100 m, (ii) 200 and 400 m, and (iii) 4 × 50 m front crawl sprint tests. Performance time (T), arm stroke rate (SR), arm stroke length (SL), and arm stroke index (SI) were calculated in all tests. Performance in short- and middle-distance tests and in 4 × 50 m training sets were related to dry-land MS, P, TF, and IMP (r = 0.51–0.83; p < 0.05). MS, P, and TF were related to SR in 50 m and SI in 50 and 100 m (r = 0.55–0.71; p < 0.05). A combination of dry-land P and in-water TF variables explains 80% of the 50 m performance time variation. Bench press power and tethered swimming force correlate with performance in short- and middle-distance tests and repeated sprint swimming. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Ballistics / Dandao Xuebao is the property of Journal of Ballistics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Objectives Artistic gymnastics is a sport where most athletes start at an early age and training volumes are high. Hence, overuse and acute injuries are frequent due to the load endured during landing tasks. During landing, the ground reaction force (GRF) is up to 15.8 times the body weight and therefore reliable GRF measurements are crucial. The gold standard for GRF measurements are force plates. As force plates are mostly used in a constrained laboratory environment, it is difficult to measure the GRF in representative training settings. Textile insoles (novel GmbH, Munich, Germany) exist, which can be used to measure dynamic GRF. Hence, the motivation of this study is to test the validity and reliability of these insoles during landing tasks. GRF was measured during four different exercises, in two test subjects and compared to concurrent force plate data. Results Twelve out of 16 statistical parametric mapping plots showed no significant difference between the measured force curves of insoles and force plates. Across conditions, the root mean square error of the maximal vertical GRF was 21 N/kg and an impulse 0.4 Ns/kg. The intraclass correlation coefficient (ICC 2,1) ranged from 0.02 to 0.76 for maximal vertical GRF and from − 0.34 to 0.76 for impulse. The insoles are a valid measurement tool for GRF curve progression and impulse during landing but underestimate the maximal vertical GRF.

In order to extend the basic theory of boundary value problems, the existence of solutions for a class of Hilfer fractional impulsive differential equations with finite impulsive points was studied. Firstly, the integral equation equivalent to the differential equation was obtained; Secondly, appropriate Banach spaces and norms were defined, and appropriate operators were constructed. When the nonlinear term satisfies different conditions, sufficient conditions for the existence of solutions of such boundary value problems were obtained by using Krasnoselskii fixed point theorem; Finally, two examples were used to illustrate the universality of the research results. It is shown that the solution of the boundary value problem of impulsive differential equations with Hilfer fractional derivative exists. By using the Krasnoselskii fixed-point theorem, the existence of solutions for impulsive differential equation boundary value problems with Hilfer fractional order can be effectively solved, which provides some reference for solving other types of impulsive fractional differential equation boundary value problems.

The discoveries he makes in his journey around the world, the admiration for the way Grotowski thinks and for Brecht’s theories, but also the history of the years 1960-1978 stir up Eugenio Barba, causing him to look for new meanings related to this art. After going through a period of disorientation and hearing around him from many people the question: what is the meaning of doing theater today?, he finds the answer: “theatre is an empty and ineffective ritual that we fill with our own why, with our personal necessity”. Barba praises the modesty and strength of the actor who considers himself the servant of the stage and not the “navel of the crowd” that surrounds him. The concepts of yoga lead him to write about the “body-spirit” and how essential it is for a performer to exercise his spirit.

Buried charges pose a serious threat to both civilians and military personnel. It is well established that soil properties have a large influence on the magnitude and variability of loading from explosive blasts in buried conditions. In this study, work has been undertaken to improve techniques for processing pressure data from discrete measurement apparatus; this is performed through the testing of truncation methodologies and the area integration of impulses, accounting for the particle size distribution (PSD) of the soils used in testing. Two experimental techniques have been investigated to allow for a comparison between a global impulse capture method and an area-integration procedure from a Hopkinson Pressure Bar array. This paper explores an area-limiting approach, based on particle size distribution, as a possible approach to derive a better representation of the loading on the plate, thus demonstrating that the spatial distribution of loading over a target can be related to the PSD of the confining material.

The purpose of this study is to investigate the influence of Personality, shopping enjoyment tendency, materialism, impulse buying tendency, and cultural dimension namely collectivism and individualism on impulse buying behavior. This study employed a quantitative approach that involved a convenience sampling technique to collect data from customers (n=320) using a structured survey. Structured Equation Modeling was applied to analyze data by using AMOS 24. According to the study's findings, shopping enjoyment tendency and materialism strongly affect impulse buying. Further, buyers with a high tendency to impulsiveness, buy more spontaneously. More importantly, the findings revealed that personality traits; neuroticism and extraversion, have also a strongly positive impact on consumers’ IBB. This study provides important information regarding the buying behavior of consumers from the retail sector of a developing nation and checks the effect of the above-mentioned important factors on consumers’ impulse buying. The outcomes of this study will help retailers and marketers to develop effective strategies in accordance with consumer buying behavior.

Rimless wheel robots are ground robots with high mobility on a variety of uneven terrains. Rimless wheels have no rims or tires but only spokes, and rimless wheel robots move along with collisions of spokes with the ground. Their equations of collision have been derived from a conservation law of angular momentum only for the simplest type of rimless wheel robots. It is uncertain when the conservation law is satisfied or violated, and what happens in the violated case. Complete equations of collision are unknown even for the simplest type of rimless wheel robots. This paper considers three types of rimless wheel robots including the simplest type and provides complete equations of collision for each type of rimless wheel robots. In addition, this paper describes properties of the dynamics during collision. Some of them reveal relationships between the dynamics of the three types of rimless wheel robots. Another shows a relationship between the dynamics of rimless wheels and circular wheels. They also clarify when the conservation law of angular momentum is satisfied or violated, and what happens in each case.

This research delves into the field of fractional differential equations with both non-instantaneous impulses and delay within the framework of Banach spaces. Our objective is to establish adequate conditions that ensure the existence, uniqueness, and Ulam–Hyers–Rassias stability results for our problems. The studied problems encompass abstract impulsive fractional differential problems with finite delay, infinite delay, state-dependent finite delay, and state-dependent infinite delay. To provide clarity and depth, we augment our theoretical results with illustrative examples, illustrating the practical implications of our work. [ABSTRACT FROM AUTHOR]

Purpose: A key determinant of long jump performance is the ability to increase the vertical velocity of the center of mass (COM) while minimizing the loss in forward velocity (running speed) during the take-off phase, but exactly how this occurs is not fully understood. We combined a three-dimensional musculoskeletal model of the body with dynamic optimization theory to simulate the biomechanics of the long jump take-off and determine the contributions of the individual leg muscles to jump performance. Methods: The body was modeled as a 29-degree-of-freedom skeleton actuated by a combination of muscles and net joint torques. A dynamic optimization problem was solved to reproduce full-body motion and ground-force data recorded from experienced subelite jumpers. The optimization solution then was analyzed to determine each muscle's contribution to the ground-force impulse and hence the change in velocity of the COM during the take-off phase. Results: The hip, knee, and ankle extensors dominated the change in velocity of the COM during take-off. Vasti (VAS) generated the highest support impulse and contributed one-third (33%) of the increase in vertical COM velocity generated by all the muscles. Soleus (SOL) and gluteus maximus (GMAX) also developed substantial support impulses and contributed 24% and 16% of the increase in vertical COM velocity, respectively. VAS also generated the highest braking impulse and contributed approximately one-half (55%) of the loss in forward COM velocity generated by all the muscles, whereas SOL and GMAX made much smaller contributions (12% and 7%, respectively). Conclusions: VAS, SOL, and GMAX contributed nearly three-quarters (73%) of the increase in vertical COM velocity at take-off, suggesting that these muscles ought to be prioritized in strength training programs aimed at improving long jump performance. [ABSTRACT FROM AUTHOR]

This study sought to elucidate kinetic and kinematic differences between unloaded and band-assisted countermovement jumps (CMJs). In a randomized order, 20 healthy subjects (mass 84.5 ± 18.6 kg) completed 3 repetitions of CMJs across 3 conditions: unloaded (at body mass), low, and moderate band (8.4 ± 1.9 and 13.3 ± 3.3 kg body mass reduction, respectively). For all repetitions, a force platform and linear position transducer were used to record and calculate kinetic and kinematic data. Body mass was significantly different between the unloaded, low, and moderate band conditions (p < 0.05). Peak velocity, absolute peak, and mean force and movement duration displayed a trend that was mostly related to the condition (i.e., unloaded > low > moderate) (p < 0.05). The opposing trend (i.e., moderate > low > unloaded) was generally observed for relative peak and mean force, reactive strength index modified, and flight time (p < 0.05). No differences were observed for mean velocity, movement duration, and absolute and relative landing forces (p > 0.05). The use of band assistance during CMJs can alter force, time, and velocity variables. Practitioners should be aware of the potential positive and negative effects of band assistance during CMJs. [ABSTRACT FROM AUTHOR]

The present reflection aims to combine the theoretical references of sociology and psychoanalysis around the human action theme. Taking as a reference some case studies presented, it was inquired about the work ethics and the admission of certain subjects to this lifestyle. It resumed the contributions of sociology as a science of culture in the understanding of the action; in particular, it discussed Max Weber's theoretical distillations on the Protestant Reformation and the building of a new social morality in which work takes a central position in the lives of subjects. The debate was concluded by presenting the limits of sociological explanation and the advances that psychoanalysis can present to the debate; in particular, the reflections on impulse, motivation, and enjoyment are resumed. [ABSTRACT FROM AUTHOR]

This paper is concerned with the existence of solutions for a nonlinear multi-term impulsive fractional q -integro-difference equation with nonlocal boundary conditions. The appropriated fixed point theorems are applied to accomplish the existence and uniqueness results for the given problem. We demonstrate the application of the obtained results with the aid of examples. [ABSTRACT FROM AUTHOR]

In flash flood events, predicting the impact loads of rushing water is helpful to detect the possible and direct damage to the downstream structures. The present study conducted three-dimensional numerical simulations for three typical laboratory experiments with emphasis on the hydrodynamic impact. Two RANS-based k-ε models and the LES model were chosen for the turbulence closure. The VOF method was applied to track the free surface. The numerical model provided satisfactory results of the temporal variations of both water depth and hydrodynamic load, which are in great agreement with the experimental data. Further quantitative comparisons also show that the deviations between simulations and experiments are small. The values of performance indicators mean-absolute deviation (MAD), root-mean-squared deviation (RMSD) and mean-absolute percentage deviation (MAPD) are respectively lower than 0.05 (0.03 m), 0.08 (0.048 m) and 19% for depth prediction, lower than 0.05 (0.03 kPa), 0.11 (0.06 kPa) and 11% for pressure prediction, and lower than 0.7 N, 1N and 15% for net force prediction. The absolute values of relative percent deviation (RPD) are less than 27% and 25% for the prediction of peak pressure and peak net force, respectively. The values of Nash–Sutcliffe efficiency (NSE) for depth and pressure are higher than 0.8. Moreover, the impulse of pressure or net force exhibits better predictability than its instantaneous values. Additional investigation shows that the time-varying behaviour of the impact force are significantly affected by the upstream initial depth, and the maximum impact force has a quadratic relationship with the initial depth. [ABSTRACT FROM AUTHOR]

To study the influences of an explosion-proof wall on shock wave parameters, an air explosion protection experiment was performed, the time history of shock wave pressure at different positions before and after the explosion-proof wall was established, and the characteristics of shock wave impulse and dynamic pressure were analyzed. The explosion-proof working conditions of five different diffraction angles were simulated and analyzed using Autodyn software(2019R3). Results indicated the following findings. The explosion-proof wall exerted an evident attenuation effect on the explosion shock wave, but considerable pressure still existed at the top of the explosion-proof wall. Overpressure behind the wall initially increased and then decreased. The larger the diffraction angle, the faster the attenuation speed of the diffraction overpressure of the shock wave in the air behind the wall. The history curve of shock wave pressure exhibited an evident bimodal structure. The shock wave diffraction of the wall made the shock wave bimodal structure behind the wall more prominent. The characteristics of the bimodal structure behind the wall (the interval time of overpressure peak Δt was less than the normal phase time of the diffracted shock wave T+) caused the shock wave impulse to stack rapidly, significantly improving its damage capability. The peak value of dynamic pressure on the oncoming surface was approximately two times the peak value of overpressure, and the inertia of air molecules resulted in a longer positive duration of dynamic pressure than overpressure. The maximum overpressure on the ground behind the explosion-proof wall appeared at approximately two times the height of the explosion-proof wall, while the maximum overpressure in the air behind the explosion-proof wall appeared at approximately one times the height of the explosion-proof wall. The relatively safe areas on the ground and in the air behind the wall were approximately 4–4.5 times and 3.5–4 times the height of the explosion-proof wall, respectively. [ABSTRACT FROM AUTHOR]

In this paper, an impulsive Cohen-Grossberg bidirectional associative neural network with both time-varying and distributed delays is examined. Novel sufficient conditions for deriving stability with a desired rate, including the exponential one, are obtained. We consider a large class of admissible kernels encompassing the existing ones. Our findings cover the existing stability results in the literature. Finally, a numerical example is given for the validation of the theoretical outcomes. [ABSTRACT FROM AUTHOR]

Aim and background: This study aimed to compare the effects of the Arch-Support insole on the values of Impulse, Vertical Loading Rate, and Free-Moment among handball players with the pronated foot during the jump and landing three-step shot technique. Material and Methods: This study was quasi-experimental and laboratory based. 10 pronated foot and 10 healthy (control group) handball male players were selected as convenience sampling. The test was performed as a pre-test and post-test in two conditions with and without the use of Arch-Support insoles during the jump and landing. Two-way ANOVA test was used for statistical analysis at the significant level (P<0/05). Results: The inter-group results showed that the vertical loading rate (P=0.032), impulse (P<0.001), and maximum free moment (P=0.013) in two groups, control, and pronated foot during jumping; Also, the vertical loading rate (P=0.001), impulse (P<0.001), and maximum free-moment (P=0.049) in two groups, control, and pronated foot during landing have significant differences. The results of the intra-group test showed that the vertical loading rate (P < 0.001), impulse (P = 0.002), and maximum free-moment (P = 0.027) during jumping; Also, the vertical loading rate (P<0.001), impulse (P=0.001), and maximum free-moment (P=0.043) during landing in the pronated foot group had a significant decrease in the post-test compared to the pre-test group. Conclusion:The use of Arch-Support insoles can prevent possible injuries to the lower limbs by reducing the values of Impulse, Vertical Loading Rate, and Free-Moment. [ABSTRACT FROM AUTHOR]

In this work, we present sufficient conditions for the oscillation of a class of forced second order neutral impulsive difference equations with deviating arguments and fixed moment of impulse effect. Furthermore, we prove the existence of a nonoscillatory solution to the aforementioned problem using Krasnosel'skii's fixed point theorem. To demonstrate our findings, we provide some illustrative examples. We point out that the results are new even for the neutral difference equations without impulse. [ABSTRACT FROM AUTHOR]

Based on the analysis of existing collective shockwave protection methods worldwide, this paper addresses the mitigation of shock waves by means of passive methods, namely the use of perforated plates. Employing specialized software for numerical analysis, such as ANSYS-AUTODYN 2022R1®, the interaction of shock waves with a protection structure has been studied. By using this cost-free approach, several configurations with different opening ratios were investigated, pointing out the peculiarities of the real phenomenon. The FEM-based numerical model was calibrated by employing live explosive tests. The experimental assessments were performed for two configurations, with and without a perforated plate. The numerical results were expressed in terms of force acting on an armor plate placed behind a perforated plate at a relevant distance for ballistic protection in engineering applications. By investigating the force/impulse acting on a witness plate instead of the pressure measured at a single point, a realistic scenario can be considered. For the total impulse attenuation factor, the numerical results suggest a power law dependence, with the opening ratio as a variable. [ABSTRACT FROM AUTHOR]

Computational fluid dynamics (CFD) technology was employed to investigate the detonation characteristics of a green high-energy metal–organic framework (HE-MOF) material. Experimental work on this relatively new class of materials is limited. Therefore, high-fidelity large-eddy Simulation (LES) is performed to investigate the impact of the explosive on the shockwave propagation and the latter interaction with obstacles. First, we validate the numerical framework against the laboratory measurements carried out for trinitrotoluene (TNT). Among the HE-MOF materials, [Cu(Htztr)2(H2O)2]n is selected due to its appropriate explosive specifications owing to its special chemical structure. The real gas equation of state of Beker–Kistiakowsky–Wilson (BKW) is employed to account for large density change of air during the explosion. For LES, an extended solver is developed within the open-source OpenFOAM package. Supersonic flow visualization clearly shows positive reflected and incident pressure. Comparisons between the TNT and HE-MOF demonstrate higher blast wave intensity and larger affected area for HE-MOF at identical times. The results of the current study suggest that the HE-MOF produces an impulse 2.5 and 2.28 times greater than TNT in the non-obstructed and obstructed sides of the explosion, respectively. [ABSTRACT FROM AUTHOR]

This paper deals with the practical exponential stability of two-dimensional (2-D) nonlinear switched positive systems with impulse, disturbance and all modes unstable. Under the mode-dependent interval dwell time switching, new criteria such that 2-D nonlinear switched positive systems achieve practical exponential stability are derived. Furthermore, the explicit upper bound and convergence rate of the system state are estimated explicitly. Numerical examples indicate the correctness and effectiveness of the obtained results. [ABSTRACT FROM AUTHOR]

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Previous research addressed the spatiotemporal variables of the drop jump (DJ) versus the horizontal drop jump (HDJ). This study compared the kinetic variables of the DJ versus the HDJ in elite jumpers and sprinters. In a single session, sixteen elite jumpers and sprinters performed two DJ attempts with three different fall heights (0.30 m, 0.40 m, and 0.50 m), and after 2 h, performed two HDJ attempts from the same fall heights (0.30 m, 0.40 m, and 0.50 m). Kinetic variables: eccentric ground reaction forces (GRFE) and concentric ground reaction forces; eccentric impulse (PE) and concentric impulse (PC); peak power in the concentric phase; and rate of force decrease (RFDe) were measured using a research-grade force plate. The Wilcoxon test was used to compare the vertical and anteroposterior axes. GRFE was significantly higher (p ≤ 0.05) in the DJ vs the HDJ with large effect sizes. The PE (p ≤ 0.006) and PC (p = 0.002) were significantly lower in the DJ than in the HDJ. The RFDe was also significantly lower in the DJ at 0.30 m vs. the HDJ at 0.30 m (p = 0.002). In summary, elite jumpers and sprinters may benefit from incorporating both the DJ and the HDJ into their training regimens, with the DJ being particularly advantageous for enhancing power metrics and RFDe.

BackgroundFemoroacetabular acetabular impingement syndrome consists of abnormal hip joint morphology resulting in painful hip joint impingement. Hip arthroscopy corrects the abnormal morphology and reduces clinical symptoms associated with femoroacetabular impingement syndrome yet the effects of hip arthroscopy on gait mechanics and cartilage health are not well understood.MethodsTen femoroacetabular impingement syndrome patients and 10 matched asymptomatic controls underwent gait analysis consisting of three-dimensional hip joint kinematics and kinetics. Femoroacetabular impingement syndrome patients underwent gait analysis and quantitative magnetic resonance imaging of the surgical hip joint before and seven months post-surgery. Patient reported outcomes were obtained from all study participants and were used to quantify hip joint pain, function and quality of life.FindingsPrior to surgery, femoroacetabular impingement syndrome patients demonstrated hip joint kinematics or kinetics as the control group. After surgery, femoroacetabular impingement syndrome patients exhibited improved patient reported outcomes, similar hip joint kinematic patterns, increased hip flexion and decreased hip extension moment impulses within the surgical limb. The femoroacetabular impingement syndrome patients that ambulated with increased HFMI post-surgery demonstrated a decrease in femoral cartilage T1ρ and T2 values.InterpretationFemoroacetabular impingement syndrome patients exhibited improved clinical symptoms yet ambulated with altered sagittal plane hip joint loading after hip arthroscopy. Increased hip flexion moment impulse post-surgery was associated with improved cartilage health within the surgical limb. These study findings suggest that sagittal plane hip joint loading at short-term follow-up after hip arthroscopy is associated with cartilage health and may be an important biomechanical parameter in post-operative rehabilitation programs.