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Steel shots are suitable for abrasive waterjet rock cutting and recycling because of the high hardness and magnetic properties of steel. This study evaluated the rock-cutting performance and recycling characteristics of steel shot waterjet. The rock-cutting responses of steel shot and garnet were compared at the same waterjet conditions. The used steel shot was collected and the particle-size changes were evaluated before reuse, and its cutting performance was re-evaluated. Overall, the steel shot waterjet yielded improvements in performance in the range of 30–50% compared with the garnet waterjet. Moreover, the recycled steel shot yielded a 50% reduction in cutting performance. Rust was observed on the surface of the used steel shot, the used steel shots were partially destroyed, and the debris on the abrasive surface needed to be removed by drying. The reusable steel shot left on the 80th sieve converged to 60% in each recycling run. The results of this study can be used to reduce the cost of abrasive waterjet and industrial waste.

Netflix’s supernatural crime series Tidelands (2019) was the subscription video service’s first commissioned original series to be produced in Australia. Shot in tropical Queensland with a diverse ...

Zero shot learning (ZSL) is aim to identify objects whose label is unavailable during training. This learning paradigm makes classifier has the ability to distinguish unseen class. The traditional ZSL method only focuses on the image recognition problems that the objects only appear in the central part of images. But real-world applications are far from ideal, which images can contain various objects. Zero shot detection (ZSD) is proposed to simultaneously localizing and recognizing unseen objects belongs to novel categories. We propose a detailed survey about zero shot detection in this paper. First, we summarize the background of zero shot detection and give the definition of zero shot detection. Second, based on the combination of traditional detection framework and zero shot learning methods, we categorize existing zero shot detection methods into two different classes, and the representative methods under each category are introduced. Third, we discuss some possible application scenario of zero shot detection and we propose some future research directions of zero-shot detection.

The aim of the paper is to investigate the influence of compressive residual stresses on the fatigue initiation life (S-Nini) curve of AISI 1141 steel. The analysis has been performed by means of a micro-structurally-based fatigue crack initiation modelling approach. The focus is set on the local (surface) residual stresses typically imposed by a surface treatment technique known as shot -peening. By superimposing such stresses on stresses resulting from outer cyclic loading, it could be shown that an impact on the fatigue curve in the S-Nini diagram can be achieved.

A promising method for diagnosing defects in the channels of firearms barrels, in particular, their erasure, providing for the use of measurement information about the ballistic elements of the shot, is considered. The application of this method should be based on the use of a data Bank on the ballistic elements of the shot, corresponding to the serviceable state of the barrel channel and different degrees of manifestation of its erasure. The purpose of the article is to obtain a mathematical description of the bore profile in the presence of areas of abrasion and to develop a mathematical model of the shot taking into account this defect. A mathematical description of the trunk channel profile in the presence of its partial removal based on trigonometric and polynomial functions is proposed. A mathematical model of the shot is developed, which takes into account the loss of part of the energy of the powder gases due to their break between the walls of the barrel and the projectile in the presence of areas of erasure of the barrel. An improved mathematical model of the shot was tested by simulating the shot process taking into account attrition using a numerical method. Based on the results of modeling, curves for the ballistic elements of the shot for different firearms samples were obtained in the presence of erasure of the barrel channel in various parts of it, and their analysis was carried out. It is shown that the location of the erasure area of the barrel bore and the degree of manifestation of this defect can be identified by the nature of the curves for the ballistic elements of the shot.

Recently, the strength of the hull structure including fatigue strength has seen significant improvement because of application of IACS CSR (Common Structure rule), developed by IACS. Various methods which can increase the fatigue strength at welded joints are suggested, since the damage morphology on the recently welded structures was observed to be primarily fatigue failure. In Shipbuilding industry, smoothening of the welding bead toe by grinding is the method that is customarily adopted in order to increase fatigue strength. And recently, peening treatment at the welding bead has also been adopted. The peening treatment can reduce stress concentration by smoothening of the welding bead toe, and a compressive residual stress field generated by the impact of peening. In case of generating compressive residual stress by impact, the same effect could be expected by shot blasting, which is the steel surface treatment before painting. In this study, the condition of the residual stress generated at welding toe by shot blasting was investigated, and then from results of the fatigue test, the increase in fatigue strength due to residual stress is verified.

PURPOSE To present a case of retinal detachment caused by a Nerf-gun shot in a pediatric patient. METHODS Single case report. RESULTS A 16-year-old white man presented with a nasal visual field deficit and floaters in his left eye for 1 month after being shot with a foam-ball Nerf gun by a friend. Fundus examination revealed a midperipheral retinal dialysis extending from 1 to 4:30 clock hours with a macula-on retinal detachment and superficial proliferative vitreoretinopathy. He underwent successful 25-gauge pars plana vitrectomy with membrane peel, retinectomy, injection of perfluoron, endolaser, and use of 1,000 centistoke silicone oil for tamponade. CONCLUSION This is the first reported case of traumatic retinal detachment secondary to a Nerf-gun shot.

Few‐shot action recognition aims to recognise unseen actions given a few examples. Thus, this letter proposes a model named meta relation network (Meta RN) to address such problem. This model contains two parts: a MetaNet and a relation network. Relation network is utilised to extract video features and classify actions. A second‐order pooling followed by power normalization is used for feature enhancement, and target videos are finally classified by exploring nonlinear distance relations. The MetaNet module is designed to model different task distributions and generate task‐adaptive parameters for the embedding layer of the relation network in different tasks. Experimental results on two public action recognition datasets demonstrate that the network achieves higher accuracies than several state‐of‐the‐art approaches.

One of the most iconic images of World War II – and one of the greatest wartime photographs ever taken – is Evgenii Khaldei’s shot of a silhouetted Red Army soldier standing on the roof of the Reic...

Tennis is a sport in which various variables related to performance influence the final result of a match. The speed and precision of the shots are among the most decisive of them. The objective of this study was to develop a test to assess the performance in terms of the speed and the precision of the forehand, backhand and serve of tennis players. The sample consisted of 4 amateur players. The analysis of the data obtained in the test provides the coach with information about the level of performance of the players and their progression.

This historical analysis will take you on a journey in time that will give you a glimpse into vibrant attractions of entertainment advertisements that will gradually come to life through the lens and scope of this amplified application of historical examination. “History is about the preservation, recording, systematic analysis, correlation, and the interpretation of events of the past.” (Godfrey, 2011, p.5) The Palmer House held events of entertainment that tell us our story of how pillars of entertainment were put in place and set in motion for us to enjoy the present day. We need a getaway and entertainment can give us just that. “The escapism ideology is related to the idea that people have a part of their lives which they do not enjoy, and, when possible, they should escape from it.” (Heiligmann, 2003, p.166) The purpose of this study is to project the story this ad tells, as the ad symbolized how the Palmer House represented a space where people can escape their daily lives and find access to a Chicago scene that began to custom design cultural standards.

The article analyzes the design features of existing flamethrowers of former Soviet Union, Russian and foreign manufacture. It is determined that the infantry rocket flamethrower can perform only a single action. A flamethrower consists of a disposable container - launcher with an aiming device in which a thermobaric warhead and a jet engine are mounted, which are separated during the shot. The shot is carried out using a launching machine attached to the disposable container - launcher. The selection of an analogue product that meets the requirements for an advanced domestic flamethrower in terms of tactical and technical characteristics was made. Analysis of the design of existing systems showed that the closest to the conditions of the technical - development requirements in terms of technical and weight-and-dimensional characteristics is RPO-A "Shmel", thus it was chosen as a prototype during the development of a domestic infantry flamethrower. The main features of the damage effects are analyzed. The main adverse factors of thermobaric warheads are determined. They are: maximum pressure, shock-wave velocity, action time of excess pressure. In the process of designing a new rocket flamethrower in order to increase the adverse factors indicators, the following decisions were made: to use nitrate ester with a lower oxygen balance, incapable of detonation transformation - isoamyl nitrite; to use an explosive of bursting charge with a higher detonation rate - okfol. Experimental studies have confirmed that the developed infantry rocket flamethrower does not rank below the world analogues, and in terms of particular characteristics (damage effects) even exceeds those analogues.

All photos by Jordan Root of specimens in his collection, except as notedFluorescent minerals are both uniquely beautiful and, in my opinion, vastly underappreciated. One factor hindering the appre...

Relevance. The paper considers shot blasting, which is a widely used method for improving the surface properties of parts (such as fatigue strength, hardness, and elongation) due to cold plastic deformation, which results in nanostructuring of the surface of the processed material, accompanied by a reduction in the grain size of its crystal structure. The conditions for the formation of a nanostructured surface layer when processing parts with a shot stream are studied. The aim of the work is to determine the conditions of nanostructuring during shot blasting due to plastic deformation, determined by the impact of the shot, which collides with the treated surface at high speed. Methods. To solve the stated problems, we used the solution of the contact problem of the theory of elasticity on the action of a concentrated force on the elastic half-space, the role of which is played by the workpiece. The conditions of the onset of plastic deformation in the surface layers of the workpiece are determined. Cold plastic deformation provides nanostructuring of the surface layer of the workpiece, increasing strength, fatigue life, atomic diffusion and improving tribotechnical characteristics. Results. Based on the contact problem of the theory of elasticity, the problem of the formation of a nanostructured layer on the surface of the workpiece during shot blasting has been solved. An analytical dependence has been obtained, which allows predicting the transition of the material to a plastic state and nanostructuring the surface of the workpiece during shot blasting.

Legal and ethical concerns have been raised since the inception of the commercial mug shot website industry in the United States. These issues include the violation of the presumption of innocence,...

Backspatter is biological material that is ejected from the entry wound against the line of fire. This phenomenon was also observed in wound ballistic simulations using so called "reference cubes" (12 cm edge length, 10% gelatin, 4 °C, paint pad beneath the cover). High-speed video records from 102 experimental shots to these target models using full metal jacketed bullets in the calibers .32 auto, .38 special, 9 mm Luger and .357 Magnum were analyzed for chronology, morphological appearance and velocity of fluid ejection. Generally, a short tail splashing of surface material occurred when the bullet was penetrating the target. In 51 shots from distance (≥ 5 cm), regardless of caliber and shot range, a linear jet of fluid started in connection with the first collapse of the temporary cavity. The initial velocity of the jet was measured between 6 and 45 m/s. The jet was streaming on for about 60 to 100 ms with a stochastic deviation of ± 13° to the horizontal. Close range and contact shots showed earlier and faster (up to 330 m/s) backspatter depending on the cartridge and the gap between muzzle and target. Gaseous aerosol-like spray and cone-like spatter indicated an increasing influence of muzzle gases with decreasing shot range. Even under standardized experimental conditions, variations of backspatter were observed in near/contact shots. Electronic supplementary material The online version of this article (10.1007/s12024-020-00326-0) contains supplementary material, which is available to authorized users.

The National Basketball Association (NBA) is the main basketball league around the globe with estimated revenue of approximately US$ 49.5 billion. A key change in NBA rules was the implementation of the three-point (3PT) line in the 1979–1980 season. Recently a popular conception claims that NBA is passing through a 3PT revolution; however, few works have discussed the evolution of shot patterns in the NBA. Thus, in this article NBA shot data per 100 possessions for each player from all seasons since implementation of the 3PT line were gathered to compare 2PT and 3PT shot statistics, aiming to understand how the shot pattern evolved throughout the NBA history. The results show that the main differences in shot patterns happened due to modifications in the 3PT line distance. The only exception was the statistically significant increase of 3PT attempts (3PTA) in the 1986–1987 season, a likely result of the success of the first 3PT contest in the previous season, which probably led most players to attempt this kind of shot. Also, the results did not show any season-by-season statistically significant change in shot patterns after the 3PT line distance was returned to its original distance in the 1997–1998 season. Thus, the actual popularity and numbers of 3PTA gradually increased throughout the seasons. Electronic supplementary material The online version of this article (10.1007/s12662-020-00690-7) contains supplementary material, which is available to authorized users.

The effects of cold work produced by peening processes in residual stress relaxation under elevated temperatures were investigated. Two types of peening processes namely shot peening and laser peening were used to generate different amount of cold work and residual stresses in the study. Characterisation of residual stress induced by cold working were carried out using X-ray diffraction coupled with electrochemical polishing method to measure the variation of residual stress with depth. Residual stresses in shot peened samples were observed to relax more rapidly than that of laser peened ones when subjected to thermal exposure. The data collected from the experimental investigation was then used to build a correlation function to model the effects of cold work on residual stress relaxation. A parameter describing cold work’s contribution to stress relaxation is introduced into the well-known Zener-Wert-Avrami (ZWA) model. The model was validated against experimental measurements and showed good agreement in both shot peened and laser peened samples.

Shot peening induces residual compressive stresses on metallic substrates, often used to decrease fatigue crack growth. The relationship between surface roughness and the magnitude of the stress can be affected by peening media size or the extent of peening. Generally, an ideal condition from shot peening would be a high compressive residual stress and a low surface roughness, but these tend to be inversely related. This study proposes a method for decreasing roughness and increasing residual stress concurrently using a distribution of shot sizes in a single shot peening passage based on finite element modeling that has been calibrated using by experimental results. Numerical models predict mixed shot sizes will create a smoother surface than using monodispersed shot at 100 % coverage. The residual stress profile for mixed shot sizes showed a broad range of compressive residual stresses in comparison with the largest impact ball size. This newly proposed method can improve the surface quality and the extent of the compressive residual stresses in a single-shot peening passage.

Losses caused by unreliable machines in a production line will affect the total cost losses from a manufacturing company's production process. Based on historical data of damage that has been obtained from the maintenance department of XYZ companies, the MACH MWJ 9/10 Shot Blast Machine is the machine that has the highest-level frequency of damage. This machine is useful for cleaning sand or residual production dirt that sticks to workpieces that have been cast in the casting process, especially for E-Clips components. The research's purpose is to determine the value of cost losses due to machine unreliability using the Cost of Unreliability (COUR) method, with Business Consequence analysis (BC) analysis. The cost effects of these costs include Corrective COUR and Downtime COUR. The final calculation of COUR shows that the total cost of COUR Downtime caused by the unreliability of the machine is greater than the total Corrective COUR. After calculating the COUR, an analysis of the business consequences resulting from the machine's unreliability is carried out using a risk matrix. The analysis results show that the shot blast machine's critical components are in the red or high-risk category and have a very high Probability of Failure (PoF). The results of COUR analysis with business consequence analysis will be an input for the company to make a machine maintenance system policy, especially for the MACH MWJ 9/10 Shot Blast machine's critical components. In general, this research's novelty is to combine the application of the Cost of Unreliability method with an analysis of the effects of the Business Consequence caused by the machine's selected critical components.

Active shooter events have captured the public’s attention since the Columbine High School shooting in 1999. Although there has been research on various aspects of these events, only a single study has attempted to identify factors that are related to the number of people injured or killed in these events. This study was limited in that it only considered the presence or absence of a semi-automatic rifle. This paper expands on the existing research by examining several other factors that may impact the total number of people shot or killed during active shooter events.

The ruling party in Turkey, the AKP, made an ex post mistake by changing the electoral law before the parliamentary elections in 2018. The new apparentement provision allowed parties to make electo...

Introduction: This study investigated the relationship between physical fitness, anthropometric characteristics, visual acuity of athletes with visual impairments, and their right shot performance. Method: The participants of the study involved 34 male athletes with different visual acuities who participated in the 2015 Visually Impaired Schools Goalball Championship in Alanya, Turkey. The means of the participants’ age, body weight, height, and sport age were 14.95 ± 1.28 years, 52.06 ± 8.89 kilograms, 163.58 ± 10.39 centimeters, 02.39 ± 1.50 years, respectively. The participants’ physical fitness, body fat percentage, handgrip (right–left), and spine flexibility were measured. Upper and lower extremity lengths were obtained through anthropometric measurements, and the athletes’ right shot performance was calculated. To analyze the data, the Shapiro–Wilk test was used, and one-way analysis of variance and independent sample t-test were performed, because the data showed a normal distribution ( p = .106). In addition, multivariate regression model analysis was utilized to investigate the relationship between all parameters and the athletes’ right shot performance. Results: A significant difference was found among the groups’ right shot performance ( p = .03), specifically on behalf of the athletes with low vision. When the participants’ anthropometric features, physical fitness values, and their right shot performance were examined, a positive relationship was observed between their dominant (right) handgrip strength and right shot performance (stepwise method; p = .03, R2 = 0.14). However, no significant difference emerged between their anthropometric characteristics and right shot performance. Discussion: It is considered that visual acuity and upper extremity muscle strength are of vital importance in goalball. Implications for practitioners: Whereas the International Blind Sports Federation applies rules according to visual acuity to offer equal conditions for some areas of sport, in goalball such a rule does not exist. It is important to make a change in the regulations for competition groupings according to visual acuities in goalball like in other sports for individuals with visual impairments. More frequent workout oriented to upper extremity muscle strength during right shot performance is suggested in the training sessions.

When present, surface-consistent (shot and/or receiver) phase instability will generate surface-consistent time shifts that are at least partially removed from seismic data when surface-consistent residual statics corrections are applied. The phase instability will not be fully corrected and lingers undetected in the data throughout the remainder of the processing workflow. After processing finishes, seismic interpreters often need to apply laterally varying phase rotations to tie their onshore 3D seismic data to synthetic seismograms, before starting detailed stratigraphic interpretation projects. We have developed and tested a new surface-consistent seismic processing workflow that can be applied to increase the phase stability of our seismic data. It is run after the final pass of conventional surface-consistent residual shot and receiver statics corrections have been applied to optimally align the seismic traces. The phase stability corrections are estimated from an additional pass of surface-consistent residual shot and receiver statics corrections that are calculated on the phase-independent seismic trace envelopes. We demonstrate the application of the workflow using synthetic and real seismic data. We gained confidence that the workflow was performing as expected after we intentionally phase rotated a small subset of the shots and receivers in our seismic test data sets and observed that the workflow corrected these intentionally phase-rotated traces with a high level of accuracy.

Reverse time migration (RTM) is a powerful seismic imaging tool that suffers from high computational complexity when dealing with massive data. The simultaneous-shot method can effectively reduce the amount of migration by assembling several sources, although it adds crosstalk noise, which seriously affects the quality of the RTM results. To avoid this problem, we have adopted a time-domain scheme that combines time-delay encoding and amplitude encoding to reduce crosstalk artifacts in simultaneous-source imaging results. This scheme modulates the wavefields of multiple sources to fit the wavefield of a suspended super-virtual shot (SVS), which can eliminate crosstalk artifacts because they are absent in single SVS migration. Numerical examples on a steeply dipping model and the 2D SEG/EAGE salt model show the feasibility of the proposed method. SVS encoding can generate a qualified imaging result and takes less time than plane-wave encoding in the migration process.

Periodontal diseases are immune inflammatory responses induced by dental plaque in which microorganisms harboured within a susceptible periodontium contributes to tissue destruction, bone loss and eventually tooth loss. The etiopathogenesis of periodontal disease is multifactorial which includes host associated factors, genetic factors, immune system dysfunction and environmental factors. Existing treatment modalities have resulted only in arresting the disease progression but have not cured the disease completely, nor do they avert the recurrence. Hence there is a need for therapeutic modalities which may include vaccines targeting periodontal pathogens. Vaccination is induction of immunity by injecting a dead or attenuated form of pathogen. Till date, no pre-emptive modality exists for periodontal disease, the availability of periodontal vaccine would prevent the progression of periodontal diseases. The aim of this review article is to confer the various approaches associated with periodontal vaccine.

Current knowledge of forensic medicine on gunshot wounds is quite limited, as every year new models of weapons and ammunition for it enter the market, which accordingly requires experimental research in this area. We should also note the rapid development of non-lethal weapon, work on research which is few in the world scientific literature.Aim of the work. To determine peculiarities of the formation of a temporary pulsating cavity caused by shots from «Fort-12RM» pistol at contact distance into a human torso imitator dressed in cotton knitwear clothing. Materials and methods. To achieve this goal, 12 human torso simulators were made and dressed in cotton T-shirts. Later, a series of shots was done using a nickel-plated Fort-12RM pistol equipped with .45 Rubber cartridges. To determine the volume of the traumatic effect of the projectile, a transverse (relative to the wound channel) incision of the injury was carried out, with the formation of blocks 1 cm thick, after which they were photographed and generally accepted calculation methods were used. Results. It was found that the smallest depth of penetration of the bullet was 4 cm, while the greatest depth of penetration of the bullet was 6 cm. On the studied models, the largest size of the temporary cavity was at the depth of cut from 3 cm to 5 cm. The peak of traumatic force falls to a depth of about 4 cm. Conclusions. The data obtained can be further applied not only to replenish theoretical knowledge on wound ballistics and an idea of the processes that occur when a bullet passes through the human body, but also for practical purposes, such as identifying firearms, ammunition, determining the distance of a shot, and the like. It is important to conduct further research using other types of weapons, clothing, imitators of other body parts and different firing distances.

Background:: In the internet era, there is a prime need to access and manage the huge volume of multimedia data in an effective manner. Shot is a sequence of frames captured by a single camera in an uninterrupted space and time. Shot detection is suitable for various applications such that video browsing, video indexing, content based video retrieval and video summarization. Objective:: To detect the shot transitions in the video within a short duration. It compares the visual features of frames like correlation, histogram and texture features only in the candidate region frames instead of comparing the full frames in the video file. Methods: This paper analyses candidate frames by searching the values of frame features which matches with the abrupt detector followed by the correct cut transition frame with in the datacube recursively until it detects the correct transition frame. If they are matched with the gradual detector, then it will give the gradual transition ranges, otherwise the algorithm will compare the frames within the next datacube to detect shot transition. Results:: The total average detection rates of all transitions computed in the proposed Data-cube Search Based Shot Boundary Detection technique are 92.06 for precision, 96.92 for recall and 93.94 for f1 measure and the maximum accurate detection rate. Conclusion:: Proposed method for shot transitions uses correlation value for searching procedure with less computation time than the existing methods which compares every single frame and uses multi features such as color, edge, motion and texture features in wavelet domain.

This paper aims to determine the relationship between the measures of shooting performance handgrip strength and weapon kinematics during different phases of the shot. The research included 35 part...

In this research, there was considered a challenge of constructing a system of scientific knowledge of the shot conditions in judicial ballistics. It was observed that there are underlying factors that are intended to ensureits [scientific knowledge] consistency: identification of the list of shot conditions, which require consideration when solving expert-level research tasks on weapons, cartridges and traces of their action; determination of the communication systems in the course of objects’ interaction, which present the result of exposure to the conditions of the shot; classification of the shot conditions based on the grounds significant for solving scientific and practical problems. The article contains the characteristics of a constructive, functional factor (condition) of weapons and cartridges influence, environmental and fire factors, the structure of the target and its physical properties, situational and spatial factors, and projectile energy characteristics. Highlighted are the forms of connections formed in the course of objects’ interaction, proposed are the author’s classifications of forensically significant shooting conditions with them being divided on the basis of the following criteria: production from the object of interaction, production from a natural phenomenon, production method, results weapon operation and utilization, duration of exposure, type of structural connections between interaction objects, number of conditions that apply when firing and the forming traces.

Fine particle shot peening has the advantages of producing compressive residual stress, microscale work hardening near the surface, and minimal surface roughness. Therefore, fine particle shot peening has been applied to numerous parts to improve fatigue strength. In this study, the shot velocity of fine zircon and stainless steel shots at four values of air pressures were precisely measured using particle image velocimetry. The shots were accelerated to a standoff distance of approximately 80 mm from the nozzle outlet. The shot velocity of the zircon shots is faster than that of the stainless steel shots. The measured shot velocity for both shots is almost proportional to the 0.5th power of the air pressure. To investigate the effect of the measured shot velocity on the residual stress distribution in an aluminum alloy (A5052) plate, a finite element model was developed for fine particle shot peening. The analyzed residual stress distributions using the accurately measured shot velocity agreed well with those measured in four test pieces using the zircon and stainless steel shots at two air pressures. The shot velocity measurement method and numerical analysis model for residual stress were both validated.

Article number 106536 Additive manufacturing (AM) of metallic parts is a relatively new manufacturing procedure. Many industry sectors, such as the aerospace or automotive sectors, have started to apply this technology to produce some elements, thus reducing costs and weight. Several metallic alloys have been employed for AM. Due to the high strength-to-density ratio, Ti6Al4V alloy is probably the alloy most used for AM in the aerospace industry. This alloy usually shows good static strength properties. However, the presence of internal defects and the surface roughness result in a fatigue strength that is clearly lower than that of materials produced by traditional pro cesses. Moreover, the scatter of the fatigue results is generally higher than in the case of wrought pieces. Different treatments have been proposed to improve the fatigue behavior by reducing internal defects and roughness or generating a favorable residual stress field. In this work, selected surface treatments were considered to improve the fatigue strength of AM parts, including shot and laser peening as well as a combination of shot peening plus chemical assisted surface enhancement (CASE®). Three groups of specimens, each with one of the surface treatments, were fatigue tested to compare the results produced by these treatments. The residual stresses, roughness and hardness produced by the treatments were analyzed. After testing, the fracture surfaces were also analyzed to better understand the fatigue process of the different groups of specimens. The results indicate that laser peening produced the best results, followed by shot peening plus CASE and shot peening. In all three cases, the fatigue strength was much higher than that of the reference group without surface treatment. It was also observed that all failures initiated from an interior defect in the shot peening plus CASE group, four out of six failures in the laser peened group, but only one failure in the case of shot peened group and none in the reference group. Failures of specimens with initiation from internal defects started from defects located deeper than the compressive residual stress layer produced by the treatments.

Objectives: To develop a rapid and accurate 4D deformable image registration (DIR) approach for online adaptive radiotherapy. Methods: We propose a deep learning (DL)-based few-shot registration network (FR-Net) to generate deformation vector fields from each respiratory phase to an implicit reference image, thereby mitigating the bias introduced by the selection of reference images. The proposed FR-Net is pretrained with limited unlabeled 4D data and further optimized by maximizing the intensity similarity of one specific four-dimensional computed tomography (4DCT) scan. Because of the learning ability of DL models, the few-shot learning strategy facilitates the generalization of the model to other 4D data sets and the acceleration of the optimization process. Results: The proposed FR-Net is evaluated for 4D groupwise and 3D pairwise registration on thoracic 4DCT data sets DIR-Lab and POPI. FR-Net displays an averaged target registration error of 1.48 mm and 1.16 mm between the maximum inhalation and exhalation phases in the 4DCT of DIR-Lab and POPI, respectively, with approximately 2 min required to optimize one 4DCT. Overall, FR-Net outperforms state-of-the-art methods in terms of registration accuracy and exhibits a low computational time. Conclusion: We develop a few-shot groupwise DIR algorithm for 4DCT images. The promising registration performance and computational efficiency demonstrate the prospective applications of this approach in registration tasks for online adaptive radiotherapy. Advances in knowledge: This work exploits DL models to solve the optimization problem in registering 4DCT scans while combining groupwise registration and few-shot learning strategy to solve the problem of consuming computational time and inferior registration accuracy.

In this study, the effect of kinetic energy of the shot peening process on microstructure, mechanical properties, residual stress, fatigue behavior and residual stress relaxation under fatigue loading of AISI 316L stainless steel were investigated to figure out the mechanisms of fatigue crack initiation and failure. Varieties of experiments were applied to obtain the results including microstructural observations, measurements of hardness, roughness, induced residual stress and residual stress relaxation as well as axial fatigue test. Then deep learning approach through neural networks was used for modelling of mechanical properties and fatigue behavior of shot peened material. Comprehensive parametric analyses were performed to survey the effects of different key parameters. Afterward, according to the results of neural network analysis, further experiments were performed to optimize and experimentally validate the desirable parameters. Based on the obtained results the favorable range of shot peening coverage regarding improved mechanical properties and fatigue behavior was identified as no more than 1750% considering Almen intensity of 21 A (0.001 inch). Graphic abstract

If we are to talk about the “effect” of a bullet, we have to start by defining our terms. Here, when we talk about the effect of a shot, we mean the reactions that the shot provokes in the human body. Consequently, an effect is always linked to a unique event.

Roxanna Curto examines how Echenoz’s turn to sport as a narrative subject corresponds to a rethinking of his notions of the relationship between fiction and reality, differences between elite and popular culture, and questions of style and efficacy. She also considers how running, much like the other sports discussed in this volume, functions as a shifting signifier whose meaning changes according to the immediate cultural and political context, including Cold War history and contemporary politics. As Curto argues, first, the work plays with its own novelistic form, using a literary, at times journalistic style of writing to present a protagonist that at the beginning appears to be a purely fictional character, but the reader later realizes is based on a real-life figure. Second, the narrative, through its discussions of Zatopek, constructs a figurative discourse for the style of the novel itself. Zatopek’s style is described as simple and inelegant yet ‘it worked,’ much like the author’s means of telling the story could be said to be direct and functional. Finally, Courir, which was published in 2008, the year of the Beijing Olympics, uses sport as a means of producing a political commentary about Communist regimes from the 1960s and today.