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In soft lithography roof collapse is frequently observed on the stamp surface consisting of rectangular micro-grooves which yields unwanted contact between the sagged surface and the substrate. Deep understanding of the adhesive contact behavior is a key to design of high-performance collapse-resistant stamp. Both theoretical and numerical studies are presented for a single rectangular micro-groove in the middle of the stamp surface under applied pressure. The JKR-type adhesion solution is established by the principle of superposition and equivalent energy release rate, with a series of closed-form expressions derived which are consistent with previous studies. Finite element analysis (FEA) is performed based on virtual crack closure technique (VCCT) to investigate the roof collapse mechanism with interfacial adhesion and applied pressure considered. Comparison of theoretical, numerical, and experimental results demonstrates that both size effect and constitutive nonlinearity of the stamp on the self-collapse contact width are not obvious for shallow grooves but become prominent for deep grooves, so that the obtained analytical solution is limited to shallow grooves due to its assumptions of half-plane and linear elasticity adopted for the stamp. For deep grooves, the present FEA method shows potential to capture more accurate results. [ABSTRACT FROM AUTHOR]

This study investigates the impact of incorporating an Inner Ring Groove (IRG) on the leakage characteristics of dry gas seals, commonly used in turbomachinery such as gas turbines and compressors. The primary objective is to enhance sealing performance and reduce gas leakage, which is critical for improving the efficiency of these machines. The research focuses on various groove shapes, including spiral grooves for single-direction rotation and T-grooves and tree grooves for bi-directional rotation. The experimental setup involved measuring air leakage rates across different seal configurations, both with and without the IRG. The results indicated that while the IRG increased leakage in spiral groove seals, it significantly reduced leakage in T-groove and tree groove seals. Specifically, the IRG reduced leakage by approximately 26% in T-groove seals and 15.8% in tree groove seals, compared to their standard configurations. Additionally, the study employed Particle Image Velocimetry (PIV) to visualize gas flow within the seal gaps. The visualization revealed that the IRG altered the flow dynamics, particularly in T-groove seals, where it redirected the gas flow from a radial to a circumferential direction, thereby reducing leakage. In contrast, the IRG in spiral groove seals promoted radial flow, leading to increased leakage. These findings suggest that the application of IRGs can be particularly effective in bi-directional rotation seals, offering a potential design modification to enhance sealing performance. The study concludes that while IRGs may not be suitable for all groove types, their strategic application can lead to significant improvements in leakage reduction and overall efficiency of dry gas seals. [ABSTRACT FROM AUTHOR]

This study searches for an effective cross-sectional shape of grooves by evaluating their trapping effect using numerical methods. Grooves are widely employed to enhance lubrication performance across various systems, including in bearings and valves, where they serve multiple functions, such as improving load-carrying capacity, addressing pressure imbalances, storing lubricant, and minimizing leakage. Beyond these roles, grooves are crucial in preventing three-body abrasive wear by capturing solid particles, such as wear debris, within the system. This study specifically focuses on the trapping effect of grooves, examining how variations in their cross-sectional shape and the Reynolds number of the lubricant used influence this effect. To evaluate the groove's trapping capability, the study analyzed particle trajectories and streamlines within the groove, as well as the number of particles effectively trapped. The results indicate that grooves with certain cross-sectional shapes, particularly those generating multiple vortices and small eddy currents, demonstrate superior trapping effectiveness. These findings contribute to the design of more efficient grooves in lubrication systems, providing insights into how groove geometry can be optimized to enhance the performance and longevity of mechanical components by mitigating wear through effective particle entrapment. This research has potential applications in the design and improvement of lubrication systems where managing wear and enhancing efficiency are critical concerns. [ABSTRACT FROM AUTHOR]

Creative movement, in the form of music- and dance-based exercise and rehabilitation, can serve as a model for learning and memory, visuospatial orientation, mental imagery, and multimodal sensory-motor integration. This review summarizes the advancement in cognitive neuroscience aimed at determining cognitive processes and brain structural and functional correlates involved in dance or creative movement, as well as the cognitive processes which accompany such activities. We synthesize the evidence for the use of cognitive, motor, and cognitive-motor function in dance as well as dance's potential application in neurological therapy and neurorehabilitation. Finally, we discuss how partnered interaction and sensorimotor integration in dance, and "dancing robots" could shed light on future application of dance as rehabilitation, of dance used in technology and potential mechanisms of benefit from dance-based activities. [ABSTRACT FROM AUTHOR]

This study investigates the impact of incorporating an Inner Ring Groove (IRG) on the leakage characteristics of dry gas seals, commonly used in turbomachinery such as gas turbines and compressors. The primary objective is to enhance sealing performance and reduce gas leakage, which is critical for improving the efficiency of these machines. The research focuses on various groove shapes, including spiral grooves for single-direction rotation and T-grooves and tree grooves for bi-directional rotation. The experimental setup involved measuring air leakage rates across different seal configurations, both with and without the IRG. The results indicated that while the IRG increased leakage in spiral groove seals, it significantly reduced leakage in T-groove and tree groove seals. Specifically, the IRG reduced leakage by approximately 26% in T-groove seals and 15.8% in tree groove seals, compared to their standard configurations. Additionally, the study employed Particle Image Velocimetry (PIV) to visualize gas flow within the seal gaps. The visualization revealed that the IRG altered the flow dynamics, particularly in T-groove seals, where it redirected the gas flow from a radial to a circumferential direction, thereby reducing leakage. In contrast, the IRG in spiral groove seals promoted radial flow, leading to increased leakage. These findings suggest that the application of IRGs can be particularly effective in bi-directional rotation seals, offering a potential design modification to enhance sealing performance. The study concludes that while IRGs may not be suitable for all groove types, their strategic application can lead to significant improvements in leakage reduction and overall efficiency of dry gas seals.

Performance behaviours of oil-lubricated sector shape pad thrust bearings incorporating the variable depth’s pockets/textures have been presented. The variable depth texture comprises of combination of grooves and pockets. Fixed depth pocket, variable depth pocket (depth of the pocket reducing towards the exit) and combination of fixed and variable depth pocket with the fixed and variable depth grooves have been considered in the present investigation. With the aim to improve the performance parameters of fixed pad thrust bearing, the effect of texture parameters such as pocket/groove depth, the circumferential extent of texture and different combinations of variable depth’s pocket and grooves have been investigated. Substantial improvement in the performance parameters (minimum film thickness and coefficient of friction) has been achieved in the presence of proposed textures having variable depths of micro-geometries.

The demand for miniature precision products is growing rapidly in many industries, which stimulates the need for efficient manufacturing technologies. Micro-milling is the most versatile process for micromachining metals and alloys. Micro-milling is characterized by difficult chip formation conditions and high specific cutting forces. When machining such difficult-to-machine materials as nitinols, these negative effects are significantly amplified due to their special physical and mechanical properties. Therefore, the study of nitinol micro-milling processes to ensure high machining efficiency is a very important issue for the current level of machining technologies. This work is devoted to the development of a finite-element model of machining a groove on the flat surface of a nitinol workpiece (Ni56,5Ti43,5 by weight) with a two-tooth carbide micro-mill in the Deform-3D program. The methodology of model development is described step by step. The features of preparing CAD models of the workpiece and the cutting tool, setting the tool properties, determining the model of the behaviour of the machined material, generating a finite element mesh, and setting the contact conditions are considered. As a result of the finite element modelling of the process of dry micro-milling of nitinol with a 1 mm diameter tool, the cutting forces for the following machining conditions were determined: cutting speed 20 m/min, cutting depth 0.2 mm, feed per tooth 0.003 mm. The adequacy of the developed model was confirmed by comparison with the results of the experimental measurements of cutting forces for the same machining conditions. The developed finite-element model of micro-milling will be used to further optimize the technological parameters of nitinol cutting in order to increase the efficiency of the micromachining process of this material.

The work is devoted to the study of the formation of stress concentrators on the inner surfaces of "tube"-type parts, the main function of which is to ensure the minimum consumption of fracture energy under the influence of tensile loads. The work shows the effectiveness of the application of deforming broaching (stitching) and technological lubricant specially developed for forming stress concentrators under the action of high contact loads, which are accompanied by deformation. The patterns of deformation hardening of the material during the formation of longitudinal grooves on the inner surfaces of parts such as bushings by deforming broaching are studied. At the qualitative level, the influence of technological parameters of the process on the distribution of microhardness along the depth of the wall of the processed part and along the cross-section profile of the tool was established. The identified regularities can be used in the design of technological operations of forming grooves by methods of cold plastic deformation and correction of technological regimes based on the requirements for mechanical characteristics that ensure the efficiency of product use. The studied regularities are valid for forming grooves in tubular products made of structural steels with a hardness in the range of HB 110-200.

Stall, a complex flow phenomenon in centrifugal pump, plays a crucial role in pump safety and stability under part-load conditions. In this paper, a verified numerical simulation method is employed to analyze the three-dimensional flow field under the stall inception conditions. The results reveal the initial stall vortex occurs near the Q=0.7Qd condition in the prototype impeller. Based on stall formation mechanism, the high-velocity fluid near the blade pressure side is sucked into suction side of next impeller channel by setting a groove near the blade leading edge. This jet flow can prevent the narrow vortices near the impeller shroud from moving towards the blade suction side, thereby suppressing the formation of stall vortex. By comparing the effects of different groove locations, directions, and sizes on stall vortex control, the optimal groove width is determined to be approximately 1mm. Compared with the prototype impeller, the grooved impeller can completely eliminate the stall vortex and significantly reduce pressure pulsation under part-load conditions. Moreover, the head of grooved impeller is increased by nearly 15% under Q=0.6Qd condition, and the potential suppression mechanism is also explained. Based on the stall formation mechanism, this paper puts forward an effective stall control method, which delays the stall inception significantly. [ABSTRACT FROM AUTHOR]

In this paper, a numerical optimization study of single-groove casing treatment was conducted on a high-speed axial compressor. One of the aims is to find the optimal structure of a single groove that can improve compressor stability with minimal loss in efficiency. Another aim is to explore suitable parameters for rapidly evaluating the compressor stall margin. A design optimization platform has been constructed in this paper, which utilizes NSGA-II and a Radial Basis Function (RBF) neural net model to carry out the optimization. The stall margin of the compressor with A single groove was accurately determined by calculating its entire overall performance line. A Pareto front is obtained through optimization, and the optimal design can be selected from the Pareto front. By considering both stall margin and efficiency loss, one of the optimal designs was found to achieve a 7.49% improvement in stall margin with a 0.24% improvement in peak efficiency. Based on the database, the effect of design parameters of a single groove on compressor stability and performance is analyzed. A series of evaluation parameters of stall margin were compared to their degree of correlation with the real stall margin calculated by the entire overall performance line. As a result, tip blockage and momentum ratio can be used as efficient parameters for quickly evaluating the compressor stall margin without the need to calculate the entire performance curve of the compressor. [ABSTRACT FROM AUTHOR]

Frictionally induced vibrations in rubber are readily triggered due to their lower stiffness and higher elasticity. This study developed a numerical model to investigate the frictional vibration of a rubber block with a groove on its side surface against an aluminum disc. The results indicate that a backside groove (GB) on the block significantly enhances vibration attenuation, with a decay time 0.6 s faster than a non-grooved (NG) block, despite a potentially higher initial vibrational amplitude. In contrast, a frontside groove (GF) results in persistent frictional oscillations, with the steady-state time being similar for both GB and GF configurations. The underlying mechanism is attributed to the GB's effectiveness in reducing the maximum energy imparted to the block initially, dissipating vibrational energy more swiftly, and distributing the contact stress more uniformly. The discrepancies in frictional forces between the conducted experiment and the simulation for the NG, GB and GF cases were 11.3%, 9.3% and 12.1%, respectively, quantitatively indicating the moderate precision of the results from the simulation. The insights gained from this study hold promise for enriching methods of mitigating vibrations arising from rubber friction. [ABSTRACT FROM AUTHOR]

Stall, a complex flow phenomenon in centrifugal pump, plays a crucial role in pump safety and stability under part-load conditions. In this paper, a verified numerical simulation method is employed to analyze the three-dimensional flow field under the stall inception conditions. The results reveal the initial stall vortex occurs near the Q=0.7Qd condition in the prototype impeller. Based on stall formation mechanism, the high-velocity fluid near the blade pressure side is sucked into suction side of next impeller channel by setting a groove near the blade leading edge. This jet flow can prevent the narrow vortices near the impeller shroud from moving towards the blade suction side, thereby suppressing the formation of stall vortex. By comparing the effects of different groove locations, directions, and sizes on stall vortex control, the optimal groove width is determined to be approximately 1mm. Compared with the prototype impeller, the grooved impeller can completely eliminate the stall vortex and significantly reduce pressure pulsation under part-load conditions. Moreover, the head of grooved impeller is increased by nearly 15% under Q=0.6Qd condition, and the potential suppression mechanism is also explained. Based on the stall formation mechanism, this paper puts forward an effective stall control method, which delays the stall inception significantly.

This study searches for an effective cross-sectional shape of grooves by evaluating their trapping effect using numerical methods. Grooves are widely employed to enhance lubrication performance across various systems, including in bearings and valves, where they serve multiple functions, such as improving load-carrying capacity, addressing pressure imbalances, storing lubricant, and minimizing leakage. Beyond these roles, grooves are crucial in preventing three-body abrasive wear by capturing solid particles, such as wear debris, within the system. This study specifically focuses on the trapping effect of grooves, examining how variations in their cross-sectional shape and the Reynolds number of the lubricant used influence this effect. To evaluate the groove’s trapping capability, the study analyzed particle trajectories and streamlines within the groove, as well as the number of particles effectively trapped. The results indicate that grooves with certain cross-sectional shapes, particularly those generating multiple vortices and small eddy currents, demonstrate superior trapping effectiveness. These findings contribute to the design of more efficient grooves in lubrication systems, providing insights into how groove geometry can be optimized to enhance the performance and longevity of mechanical components by mitigating wear through effective particle entrapment. This research has potential applications in the design and improvement of lubrication systems where managing wear and enhancing efficiency are critical concerns.

Performance behaviours of oil-lubricated sector shape pad thrust bearings incorporating the variable depth's pockets/textures have been presented. The variable depth texture comprises of combination of grooves and pockets. Fixed depth pocket, variable depth pocket (depth of the pocket reducing towards the exit) and combination of fixed and variable depth pocket with the fixed and variable depth grooves have been considered in the present investigation. With the aim to improve the performance parameters of fixed pad thrust bearing, the effect of texture parameters such as pocket/groove depth, the circumferential extent of texture and different combinations of variable depth's pocket and grooves have been investigated. Substantial improvement in the performance parameters (minimum film thickness and coefficient of friction) has been achieved in the presence of proposed textures having variable depths of microgeometries. [ABSTRACT FROM AUTHOR]

This paper reports on an experiment that investigated how guitarists signal the intended timing of a rhythmic event in a groove-based context via three different features related to sound-producing motions of impulsive chord strokes (striking velocity, movement duration and fretboard position). 21 expert electric guitarists were instructed to perform a simple rhythmic pattern in three different timing styles—"laidback," "on-the-beat," and "pushed"—in tandem with a metronome. Results revealed systematic differences across participants in the striking velocity and movement duration of chords in the different timing styles. In general, laid-back strokes were played with lower striking velocity and longer movement duration relative to on-the-beat and pushed strokes. No differences in the fretboard striking position were found (either closer to the "bridge" [bottom] or to the "neck" [head]). Correlations with previously-reported audio features of the guitar strokes were also investigated, where lower velocity and longer movement duration generally corresponded with longer acoustic attack duration (signal onset to offset).

First described by Schachter & Singer (1962), the phenomenon of misattributed arousal (arousal perceived as coming from a wrongly presumed source and irrelevantly influencing evaluations of it) has been widely documented, with two recent studies, Marin, Schober, Gingras, & Leder (2017) and Chang et al. (2021), providing suggestive evidence of music as a source of misattributed arousal with an enhancing effect on sexual attraction. The aim of the present study was to provide more unambiguous evidence of such a musical arousal effect. In an online experiment simulating a face-to-face dating event, participants (41 females and 43 males) rated the attractiveness of opposite-sex faces in a series of slideshows presented twice, once accompanied by a high-groove drum track and the other time by a low-groove drum track. They then rated the drum tracks for groove. While whole-sample analyses yielded no significant findings, subsample analyses showed that the groove ratings of the male participants, though not the female participants, positively predicted their attractiveness ratings, in partial support of the arousal hypothesis. We discuss possible reasons for the pattern of findings, including sex differences in groove response and more generally in the evaluation of cues of physiological arousal.

Motivation for bodily movement, physical activity and exercise varies from moment to moment. These motivation states may be "affectively-charged," ranging from instances of lower tension (e.g., desires, wants) to higher tension (e.g., cravings and urges). Currently, it is not known how often these states have been investigated in clinical populations (e.g., eating disorders, exercise dependence/addiction, Restless Legs Syndrome, diabetes, obesity) vs. healthy populations (e.g., in studies of motor control; groove in music psychology). The objective of this scoping review protocol is to quantify the literature on motivation states, to determine what topical areas are represented in investigations of clinical and healthy populations, and to discover pertinent details, such as instrumentation, terminology, theories, and conceptual models, correlates and mechanisms of action. Iterative searches of scholarly databases will take place to determine which combination of search terms (e.g., "motivation states" and "physical activity"; "desire to be physically active," etc.) captures the greatest number of relevant results. Studies will be included if motivation states for movement (e.g., desires, urges) are specifically measured or addressed. Studies will be excluded if referring to motivation as a trait. A charting data form was developed to scan all relevant documents for later data extraction. The primary outcome is simply the extent of the literature on the topic. Results will be stratified by population/condition. This scoping review will unify a diverse literature, which may result in the creation of unique models or paradigms that can be utilized to better understand motivation for bodily movement and exercise.

The article is devoted to the development and analysis of a model of the motion of a micropolar lubricant in the working gap of a radial plain bearing with a fluoroplastic-containing antifriction composite polymer coating and with a groove on the supporting surface. New models are obtained on the basis of classical equations in the «thin layer» approximation and the continuity equation, which describes the turbulent mode of motion of a lubricant with micropolar rheological properties. The results of the numerical analysis of the obtained models of existing operational characteristics made it possible to obtain a quantitative assessment of the effectiveness of the support profile with a fluoroplastic-containing antifriction composite polymer coating with an axial groove. To complete the complex of studies and verify theoretical developments, experimental studies are carried out. The novelty of the work lies in the concretization of the technique of engineering calculations for the design of an effective radial bearing with an antifriction polymer coating with an axial groove on the bearing surface of the bearing bush, taking into account the dependence of the rheological properties of a micropolar lubricant on pressure and temperature in a turbulent mode, which makes it possible to estimate the value of the main operational characteristics: hydrodynamic pressure, load ability and coefficient of friction, as well as to expand the scope of practical application of models for engineering calculations. Thus, the design of a radial bearing with a polymer-coated support profile, a groove 3 mm wide, ensured a stable ascent of the shaft on a hydrodynamic wedge, which experimentally confirmed the correctness of the results of theoretical studies of a radial bearing with a diameter of 40 mm at a sliding speed of 0,32–3 m/s, load 4,9–24,5 MPa.

In modern heavy-loaded friction units, various types of antifriction coatings are used on the surface of the bearing profile of the bearing sleeve to ensure high load-bearing capacity and increase the duration of the hydrodynamic regime, and consequently, the economic effect of sliding bearings. In the study, the creation and development of mathematical models of a radial sliding bearing with an antifriction polymer coating of the support surface containing a groove is carried out. The key role here is played by the method of analytical forecasting, which determines the mechanism of friction and the conditions for its transition from boundary to liquid. The aim of the study is to develop a mathematical model of a radial sliding bearing with a polymer coating of the bearing sleeve bearing surface containing an axial groove to predict the economic effect. The objective of the study is to develop new mathematical models and analyze the movement of lubricant in the working gap of a radial sliding bearing, taking into account design features to predict the economic effect. The difference from the existing models of tribosystems with antifriction coatings is the presence of a groove, which ensures stable ascent of the shaft on the hydrodynamic wedge and reduces wear during start-up and run-outs, hence increasing the service life of tribosystems. Using the lubricant motion equation and the continuity equation, new mathematical models are obtained that take into account the design features of the bearing sleeve surface – polymer coating, groove width, rheological properties of the lubricant used. Based on the results of an experimental study on the AI 5018 friction machine, the economic efficiency of net discounted income was calculated on samples in the form of partial inserts. As a result of the research, new mathematical models for engineering calculations have been developed that allow predicting the efficiency, reliability and duration of the hydrodynamic lubrication regime, as well as determining the main tribotechnical parameters. Net discounted income based on the results of theoretical and experimental research is estimated at 0.36 million rubles per year.

This study applied femtosecond laser processing technology to prepare microgrooves on the surface of SiC/SiC ceramic matrix composites (CMCs). The corresponding parameter ranges for response surface optimization were determined through single-factor experiments. Additionally, four quadratic regression models were established to predict surface roughness, groove width, groove depth, and volume material removal rate. The Analysis of Variance (ANOVA) revealed that the developed model was reliable. Additionally, the study investigated the effects of laser parameters such as power, scanning speed, and defocusing amount, as well as their interactions, on various outcome measures, including the roughness average (Ra), groove width, groove depth, and volume material removal rate (VRR). To optimize the process parameters, the response surface method was employed to achieve maximum VRR and minimum Ra. After conducting the analysis, the optimal processing parameters were determined to be a laser power of 36 W, a scanning speed of 24 mm/s, and a defocusing amount of −1.17 mm. The developed model accurately predicts groove depth, width, volume material removal rate, and surface roughness in SiC/SiC-CMCs processing. The relative deviations between the actual and expected values fall within the acceptable range, affirming model's reliability. This indicates that the model improves precision in predicting these parameters for SiC/SiC-CMCs processing. The findings of this study have significant implications for improving the processing quality and efficiency of SiC/SiC-CMCs and establishing a relationship between processing parameters and responses. These insights can inform future research efforts to optimize these complex materials' manufacturing processes. • A Multiple regression equation prediction model between laser processing parameters and output response is developed. • The effect of laser processing parameters on response under multiple factors is explored. • The optimal parameters within the selected parameter range are set based on response surface methodology. • Micro-grooves are fabricated by femtosecond laser on SiC/SiC composites. [ABSTRACT FROM AUTHOR]

This paper sought to demonstrate how the idea of groove produces specific musical performances of the double bass in samba and to understand the conceptual field through which double bassists construct this phenomenon within the musical culture. The methodology identified interpretative resources from data collected in an experiment involving 19 instrumentalists. The subjects were instructed to construct improvised bass lines over a harmonic structure presented a priori. The musical events present in each instrumentalist's recordings were annotated, classified, and analyzed with computational data visualization resources. The results show an interpretation map where the idea of groove is expressed in the samba rhythm with the use of interpretative resources and specific techniques such as ghost notes and slaps. Strategies of temporal and sequential structuring of technical resources were also presented, enriching the understanding of the groove phenomenon in the specific practice of bassists in samba. [ABSTRACT FROM AUTHOR]

Internal combustion engines, during their operation, subject the piston to high-temperature and high-pressure conditions, requiring it to endure intense, continuous reciprocating motion. This strenuous process leads to significant wear and tear. Among the engine's crucial components, the piston ring plays a pivotal role but is particularly susceptible to wear. Therefore, extensive research has been devoted to investigating the wear of piston rings, a critical sealing component within internal combustion engines. To address the high cost of existing coating methods, which hinders widespread application, we propose a bionic design approach inspired by groove structures observed on earthworm bodies, aimed at enhancing the wear resistance of piston rings. Bionic piston rings featuring optimally designed groove structures inspired by the earthworm's anatomy were designed. These rings exhibited varying groove depths (1 mm, 2 mm, and 3 mm), groove widths (0.1 mm, 0.3 mm, and 0.5 mm), and groove spacings (0.1 mm, 0.2 mm, and 0.3 mm). We conducted thermal–structural coupling analyses on both standard piston rings and these bionic counterparts. The results revealed that the maximum stress was concentrated at the first piston ring, precisely at the opposing region of the end gap. Thus, the initial piston ring endured the primary frictional losses. Moreover, a comparison of stress levels between bionic rings and the standard ring revealed that the bionic groove structure substantially reduced stress and minimized stress concentration, thus enhancing wear resistance. Groove width had the most notable influence on wear performance, followed by groove depth and groove spacing. Optimal wear resistance was achieved when the groove depth was 3 mm, groove width was 0.1 mm, and groove spacing was 0.1 mm. Subsequently, we constructed a piston ring friction test bench to validate the wear resistance of the most effective piston ring. The results indicated that the wear resistance of the bionic piston ring exceeded that of the standard piston ring by up to 19.627%. Therefore, incorporating a bionic groove structure within the piston ring can effectively reduce surface friction and enhance wear resistance. This, in turn, can enhance the operational lifespan of internal combustion engines under favorable working conditions. [ABSTRACT FROM AUTHOR]

In this paper, a numerical optimization study of single-groove casing treatment was conducted on a high-speed axial compressor. One of the aims is to find the optimal structure of a single groove that can improve compressor stability with minimal loss in efficiency. Another aim is to explore suitable parameters for rapidly evaluating the compressor stall margin. A design optimization platform has been constructed in this paper, which utilizes NSGA-II and a Radial Basis Function (RBF) neural net model to carry out the optimization. The stall margin of the compressor with A single groove was accurately determined by calculating its entire overall performance line. A Pareto front is obtained through optimization, and the optimal design can be selected from the Pareto front. By considering both stall margin and efficiency loss, one of the optimal designs was found to achieve a 7.49% improvement in stall margin with a 0.24% improvement in peak efficiency. Based on the database, the effect of design parameters of a single groove on compressor stability and performance is analyzed. A series of evaluation parameters of stall margin were compared to their degree of correlation with the real stall margin calculated by the entire overall performance line. As a result, tip blockage and momentum ratio can be used as efficient parameters for quickly evaluating the compressor stall margin without the need to calculate the entire performance curve of the compressor.

This article proposes a model that unites a broad range of performances of Mande drumming music within a single cohesive and fluid sub-beat metric framework. The framework categorizes musical performance in terms of two metric modes, each of which includes a set of metric cycles featuring non-isochronous pulsations. A novel feature of the proposed model that distinguishes it from previous research is that it frames metric non-isochrony in terms of the ranges for pulsation positions within a pulsation cycle. This approach is shown to be especially useful for analyzing and describing mechanisms of metrical change and transformation and for connecting seemingly distinct phenomena and repertoire. [ABSTRACT FROM AUTHOR]

In a previous paper, we solved the partial differential equation of Mullins' problem in the case of the evaporation–condensation in electronic devices and gave an exact solution relative to the geometric profile of the grain boundary grooving when materials are submitted to thermal and mechanical solicitation and fatigue effect. In this new research, new modelling of the grain groove profile was proposed and new analytical expressions of the groove profile, the derivative and the groove depth were obtained in the case of diffusion in thin polycrystalline films by the resolution of the fourth differential equation formulated by Mullins that supposed y ′ 2 ≪ 1 . The obtained analytical solution gave more accurate information on the geometric characteristics of the groove that were necessary to study the depth and the width of the groove. These new findings will open a new way to study with more accuracy the problem of the evaporation–condensation combined to the diffusion phenomenon on the material surfaces with the help of the analytical solutions. [ABSTRACT FROM AUTHOR]

Interconnects have become a major obstacle in chip scaling. Spoof surface plasmon polariton (SSPP) modes have gained attention for their ability to manipulate light beyond diffraction limits at a given frequency, leading to SSPP interconnects. This article investigates the transmission characteristics of SSPP interconnect pairs placed side by side in the terahertz frequency range with comprehensive performance analysis. The proposed SSPP waveguide pair exhibits a maximum transmission coefficient of around −0.05 dB in the −3 dB band in the terahertz frequency range. Due to field confinement near the metal–dielectric interface, energy remains confined for the designed SSPP interconnect pair system. The proposed SSPP structure shows several bands in the terahertz frequency range, whereas conventional interconnects shows almost zero transmission at such frequencies. Additionally, the effect of geometric parameters on transmission coefficients (S 21 ) and coupling coefficients (S 41 ) has been investigated. Moreover, it has been shown that the bandwidth, as well as the upper cutoff frequency, can be tuned by varying the geometric parameters such as groove height, groove width and groove density. Since global interconnects undergo bending in actual circuits during distant data transmission on chips, geometric mismatches may occur between adjacent pairs of SSPP interconnects. Hence, it has also been examined how bending and mismatches affect transmission and coupling coefficients. Several SSPP schemes have been simulated, among which the best performance is obtained with 2 μ m mismatch in groove height. For this optimized design, two corrugated metal interconnects are considered with groove heights of 20 μ m and 22 μ m, respectively, a groove width of 3 μ m, a period of 20 μ m, and the number of grooves at 50. For this particular configuration, an ultra-wide passband is found having a bandwidth of almost 400 GHz, with a signal reflection of below −12 dB and little insertion loss of ∼−1.43 dB. [ABSTRACT FROM AUTHOR]

Perforeli çimentolu levhalar özellikle iç mekân gürültü kontrolünde bir ses emici malzeme olarak kullanılmaktadır. Bu çalışmada, plakaların bir yüzeyinden ortalama 4 mm genişliğinde ve 6 mm derinliğinde oluklar (yarıklar) açılarak bir yüzü oluklu ve derzli form kazandırılmıştır. Çalışma kapsamında akustik performans irdelemesi için üç ayrı perforasyon oranı tasarlanmış olup sırasıyla %5.5, %8.0 ve %12.6 oranları elde edilecek şekilde levha örneklerinin diğer yüzeyinde ortalama 10 mm derinliğinde delikler açılarak perforeli test örnekleri hazırlanmıştır. Bu forma dönüştürülen levhaların ses yutma özellikleri irdelenmiştir. Delikli perforeli test örnekleri için uygulanabilirlik kesitine bağlı olarak 3 ayrı grup numune hazırlanmıştır. Bunlar; tek bileşenli yalın formda derzli perforeli çimento bağlayıcılı akustik levha (Yalın-I levhası), geotekstil katmanlı iki bileşenli derzli perforeli çimento bağlayıcılı kompozit akustik levha (Geo-II levhası) ve polietilen esaslı kauçuk katmanlı iki bileşenli derzli perforeli çimento bağlayıcılı kompozit akustik levha (PE-II levhası). Her üç grubun ses yutma özelliği referans örneği olarak test edilen düz-dolu yüzey formunda herhangi bir derz ve perfore işlemi yapılmamış elyaf takviyeli çimentolu yalın levha örneği (kontrol levhası) ile karşılaştırılmıştır. Çalışma sonuçlarına göre, derzli perforeli form kazandırılmış levha örneklerinin perforesiz düz levha formu performansları ile karşılaştırıldığında görüldüğü üzere düz levhanın absorpsiyon özelliği yüksek frekans band değişiminde artış gösterirken, derzli perforeli levhaların absorpsiyon özelliğinin ise düşük frekans bölgelerinde daha etkin absorpsiyon özelliği göstermektedir. Ayrıca, polietilen esaslı kauçuk malzemenin yalıtım katmanı olarak kullanımı, derzli ve perforeli kompozit formda çimento bağlayıcılı akustik levhaların ses azaltma karakteristiğine perforasyon oranına bağlı olarak yüksek emici ve/veya mükemmel emici birer nitelik kazandırmaktadır.

Introduction. In modern heavy-loaded friction units, metallopolymer coated bearings operating in the boundary friction mode are widely used. Their successful application is provided by the viscoelastic deformation of these coatings under load. To pass from boundary friction to liquid friction, it is required to create a bearing hydrodynamic wedge. Currently, the use of journal bearings with polymer-coated grooved support ring is hindered by the lack of a methodology for their calculation. This work analyzes a model of movement of a micropolar lubricant in the operating clearance of a journalbearing with a nonstandard support profile having a PTFE composite coating with a groove on the bearing surface. The study aims at establishing the dependence of the stable hydrodynamic regime on the width of the groove on the surface of the bearing profile. Materials and Methods. Tribological tests of journal bearings with a nonstandard bearing profile having a polymer coating with a groove on the surface were carried out on samples in the form of partial bushes (blocks). Using the equation of movement of a lubricant with micropolar rheological properties, as well as the continuity equation, new mathematical models were obtained that took into account the width of the groove, polymer coating, and nonstandard bearing profile. Results. A significant expansion of the applicability of design models of journal bearings with structural changes has been achieved. Polymer-coated bearings with a groove provided a hydrodynamic lubrication mode. The results obtained allowed us to evaluate the operational characteristics of the bearing: hydrodynamic pressure value, load capacity, and coefficient of friction. Discussion and Conclusions. The design of polymer coated journal bearing and a groove 3 mm wide on the surface of the liner provided a stable ascent of the shaft on the hydrodynamic wedge, which was validated experimentally. The experiments were carried out for journal bearings with a diameter of 40 mm with a groove 1–8 mm wide, at a sliding speed of 0.3–3 m/s and a load of 4.8–24 MPa.

The paper covers the development and analysis of a model of the true viscous lubricant movement in the working gap of a radial sliding bearing with a non-standard support profile having a fluoroplastic composite polymer coating with a groove on the shaft surface. The authors obtained new models based on the classical equation in the approximation for the “thin layer” and the continuity equation describing the laminar pattern of movement of a lubricant with the viscous rheological properties. The results of the numerical analysis of the developed models allowed obtaining a quantitative assessment of the efficiency of the bearing bush support profile and the polymer-coated shaft with an axial groove. To complete the set of studies and verify theoretical insights, the authors carried out the experimental research. The novelty of the work lies in the development of an engineering calculation technique that allows determining the magnitude of the main tribotechnical parameters of a radial sliding bearing (hydrodynamic pressure, load capacity, and friction ratio) and expanding the area of practical application of the developed engineering calculations. The design of the radial bearing with a fluoroplastic antifriction composite polymer coating, a 3 mm wide groove, and a special support profile ensured the stable shaft ascent on the hydrodynamic wedge, which experimentally confirmed the correctness of the results of theoretical studies of sliding bearings with a diameter of 40 mm at a sliding speed of 0.3–3 m/s and a load of 13–65 MPa.

The article is devoted to one of the important problems of increasing the wear resistance of tribosystems by applying an antifriction polymer composite coating containing a groove that operates in a hydrodynamic mode to the tribocontact surface. Based on the equation of the flow of truly viscous liquid for a «thin layer» and the continuity equation, a self-similar solution is found taking into account the groove and without taking into account the groove, as a result, the velocity and pressure fields in the groove and on the surface of the polymer antifriction composite coating are determined, as well as the load capacity and friction force allowing to determine the increase in wear resistance; an increase in duration of the hydrodynamic regime. The results of numerical analysis of the obtained theoretical calculation models and experimental evaluation of the proposed design are also presented in order to verify and confirm the effectiveness of the obtained theoretical models.

The paper describes the critical Reynolds number of soccer balls as a function of the total groove volume on the ball surface. In this study, the aerodynamic drag and separation point of 6 soccer balls with different panel orientations were measured in a wind tunnel. Moreover, the total volume of grooves on the ball’s surface was measured by One shot 3D measuring machine. It was found that the drag coefficient in the supercritical region and the critical Reynolds number depend on the design of the ball surface (shape, number of panels, surface roughness). A negative correlation exists between the total groove volume on the surface and the critical Reynolds number. When the total groove volume is large, the drag in the supercritical region increases. The position of the separation point does not change in the subcritical and supercritical regions even if the orientation of the panel is changed. However, when the groove width is wider, the panel orientation dependence becomes significant in the supercritical region. In the transition region, the position of the separation point differs depending on the panel's orientation.

Capacitive pressure sensors based on porous structures have been widely researched and applied to a variety of practical applications. To date, it remains a big challenge to develop a capacitive pressure sensor with a high sensitivity and good linearity over a wide pressure range. In this paper, a sensitive, flexible, porous capacitive pressure sensor was designed and manufactured by means of the "salt template method" and man-made grooves. To this aim, the size of the salt particles used for forming pores/air voids, time taken for thorough dissolution of salt particles, and the depth of the man-made groove by a pin were taken into consideration to achieve a better effect. With pores and the groove, the sensor is more liable be compressed, which will result in a dramatic decrease in distance between the two electrodes and a conspicuous increase of the effective dielectric constant. The optimize-designed sensor represents a sensitivity 6–8 times more than the sensor without the groove in the pressure range of 0–10 kPa, not to mention the sensor without pores or the groove, and it can keep good linearity within the measurement range (0–50 kPa). Besides, the sensor shows a low detection limit of 3.5 Pa and a fast response speed (≈50 ms), which makes it possible to detect a tiny applied pressure immediately. The fabricated sensor can be applied to wearable devices to monitor finger and wrist bending, and it can be used in the object identification of mechanical claws and object cutting of mechanical arms, and so on. [ABSTRACT FROM AUTHOR]

In actual use, a steel wire rope is often stretched and twisted around a groove, increasing the risks of contact fatigue, friction and wear at the rope-groove interface under a long-term service condition. With the consideration of influence factors such as the nonlinear contact and wear between the rope and groove, the tribological performance at the rope-groove interface during a twisting process is analyzed in this study. A winding rope-groove model is first established in order to obtain the contact and sliding solutions at the interface between the rope and groove, which are then used as the load conditions of a simplified local model that is built for wear solution using a modified Archard's wear theory. Based on the finite element simulation software ABAQUS, the ALE adaptive mesh technology and UMESHMOTION subroutine secondary development are adopted to analyze the evolutions of wear topography and contact behavior between the rope and the groove. The results show that the twisting movement of the steel wire rope around the groove causes an interfacial wear between them. The wear scars occur on the outside wire of the steel wire rope and the bottom area of the groove, and the wear scar on the groove is smaller but deeper. A ring-shaped region of stress concentration happens near the edge of wear region. As the wear process proceeds, the depths and dimensions of the wear scars increase, while the contact pressure decreases. The contact performance and wear change dramatically at the beginning of wear process and tend to be stable subsequently. An increment of lay angle of the outside wire aggravates the wear and contact between the steel wire rope and the groove. • A numerical method for cyclic wear between twisting rope and groove is proposed. • The wear scar on the groove is smaller but deeper than that on the steel wire rope. • A ring-shaped region of stress concentration occurs near the edge of wear region. • The wear deteriorates while the contact alleviates with the wear process. • An increase in the lay angle aggravates the wear and contact behavior. [ABSTRACT FROM AUTHOR]

Internal combustion engines, during their operation, subject the piston to high-temperature and high-pressure conditions, requiring it to endure intense, continuous reciprocating motion. This strenuous process leads to significant wear and tear. Among the engine’s crucial components, the piston ring plays a pivotal role but is particularly susceptible to wear. Therefore, extensive research has been devoted to investigating the wear of piston rings, a critical sealing component within internal combustion engines. To address the high cost of existing coating methods, which hinders widespread application, we propose a bionic design approach inspired by groove structures observed on earthworm bodies, aimed at enhancing the wear resistance of piston rings. Bionic piston rings featuring optimally designed groove structures inspired by the earthworm’s anatomy were designed. These rings exhibited varying groove depths (1 mm, 2 mm, and 3 mm), groove widths (0.1 mm, 0.3 mm, and 0.5 mm), and groove spacings (0.1 mm, 0.2 mm, and 0.3 mm). We conducted thermal–structural coupling analyses on both standard piston rings and these bionic counterparts. The results revealed that the maximum stress was concentrated at the first piston ring, precisely at the opposing region of the end gap. Thus, the initial piston ring endured the primary frictional losses. Moreover, a comparison of stress levels between bionic rings and the standard ring revealed that the bionic groove structure substantially reduced stress and minimized stress concentration, thus enhancing wear resistance. Groove width had the most notable influence on wear performance, followed by groove depth and groove spacing. Optimal wear resistance was achieved when the groove depth was 3 mm, groove width was 0.1 mm, and groove spacing was 0.1 mm. Subsequently, we constructed a piston ring friction test bench to validate the wear resistance of the most effective piston ring. The results indicated that the wear resistance of the bionic piston ring exceeded that of the standard piston ring by up to 19.627%. Therefore, incorporating a bionic groove structure within the piston ring can effectively reduce surface friction and enhance wear resistance. This, in turn, can enhance the operational lifespan of internal combustion engines under favorable working conditions.

Interacting with music is a uniquely pleasurable activity that is ubiquitous across human cultures. Current theories suggest that a prominent driver of musical pleasure responses is the violation and confirmation of temporal predictions. For example, the pleasurable urge to move to music (PLUMM), which is associated with the broader concept of groove, is higher for moderately complex rhythms compared to simple and complex rhythms. This inverted U-shaped relation between PLUMM and rhythmic complexity is thought to result from a balance between predictability and uncertainty. That is, moderately complex rhythms lead to strongly weighted prediction errors which elicit an urge to move to reinforce the predictive model (i.e., the meter). However, the details of these processes and how they bring about positive affective responses are currently underspecified. We propose that the intrinsic motivation for learning progress drives PLUMM and informs the music humans choose to listen to, dance to, and create. Here, learning progress reflects the rate of prediction error minimization over time. Accordingly, reducible prediction errors signal the potential for learning progress, producing a pleasurable, curious state characterized by the mobilization of attentional and memory resources. We discuss this hypothesis in the context of current psychological and neuroscientific research on musical pleasure and PLUMM. We propose a theoretical neuroscientific model focusing on the roles of dopamine and norepinephrine within a feedback loop linking prediction-based learning, curiosity, and memory. This perspective provides testable predictions that will motivate future research to further illuminate the fundamental relation between predictions, movement, and reward. [ABSTRACT FROM AUTHOR]

The optimal groove design of a MEMS piezoresistive pressure sensor for ultra-low pressure measurement is proposed in this work. Two designs of the local groove and one design of the annular groove are investigated. The sensitivity and linearity of the sensor are investigated due to the variations of two dimensionless geometric parameters of these grooves. The finite element method is used to determine the stress and deflection of the diaphragm in order to find the sensor performances. The sensor performances can be enhanced by creating the annular or local groove on the diaphragm with the optimal dimensionless groove depth and length. In contrast, the performances are diminished when the local groove is created on the beam at the piezoresistor. The sensitivity can be increased by increasing the dimensionless groove length and depth. However, to maintain low nonlinearity error, the annular and local grooves should be created on the top of the diaphragm. With the optimal designs of annular and local grooves, the net volume of the annular groove is four times greater than that of the local groove. Finally, the functional forms of the stress and deflection of the diaphragm are constructed for both annular and local groove cases. [ABSTRACT FROM AUTHOR]

Listening to groovy music is an enjoyable experience and a common human behavior in some cultures. Specifically, many listeners agree that songs they find to be more familiar and pleasurable are more likely to induce the experience of musical groove. While the pleasurable and dance-inducing effects of musical groove are omnipresent, we know less about how subjective feelings toward music, individual musical or dance experiences, or more objective musical perception abilities are correlated with the way we experience groove. Therefore, the present study aimed to evaluate how musical and dance sophistication relates to musical groove perception. Onehundred 24 participants completed an online study during which they rated 20 songs, considered high- or low-groove, and completed the Goldsmiths Musical Sophistication Index, the Goldsmiths Dance Sophistication Index, the Beat and Meter Sensitivity Task, and a modified short version of the Profile for Music Perception Skills. Our results reveal that measures of perceptual abilities, musical training, and social dancing predicted the difference in groove rating between high- and low-groove music. Overall, these findings support the notion that listeners' individual experiences and predispositions may shape their perception of musical groove, although other causal directions are also possible. This research helps elucidate the correlates and possible causes of musical groove perception in a wide range of listeners. [ABSTRACT FROM AUTHOR]

During the present study, a double groove texture was designed on the surface of a piston ring to improve the sealing performance between the piston ring and cylinder liner. The experimental design method was used to fabricate the test plan according to the groove width, depth, and spacing. By using the thermal–structural coupling analysis method, the finite element analysis of the standard piston ring and the textured piston ring was carried out to simulate the deformation state of the cylinder liner system of the piston ring group during the working stroke. The piston rings with different parameters designed by the test scheme were manufactured by wire electrical discharge machining, and the self-made experiment device carried out the sealing test. The results showed that the groove texture could improve the sealing performance of the piston ring, and the analyzed results demonstrated that the groove texture had little effect on the maximum deformation of the piston ring. Still, it could significantly reduce the minimum deformation of the piston ring group. A piston ring with groove texture would improve the sealing performance and reduce the deformation during the work stroke. During the test, the average deformation of the No.7 piston ring group, with a groove depth of 1 mm, a groove width of 0.5 mm, and a groove spacing of 0.1 mm, was the smallest, about 29.6% lower than that of the standard piston ring group. The sealing performance of the No.7 piston ring group was the best, and the reduction rate of the top gas leakage rate was 52.18%. During the present study, the sealing performance of the piston ring was improved by designing the grooved structure on the piston ring surface, thereby improving the fuel economy and power performance of the engine. The present study could provide a reference for the engineering field to design a piston ring with high sealing performance. [ABSTRACT FROM AUTHOR]

Listening to groovy music is an enjoyable experience and a common human behavior in some cultures. Specifically, many listeners agree that songs they find to be more familiar and pleasurable are more likely to induce the experience of musical groove. While the pleasurable and dance-inducing effects of musical groove are omnipresent, we know less about how subjective feelings toward music, individual musical or dance experiences, or more objective musical perception abilities are correlated with the way we experience groove. Therefore, the present study aimed to evaluate how musical and dance sophistication relates to musical groove perception. One-hundred 24 participants completed an online study during which they rated 20 songs, considered high- or low-groove, and completed the Goldsmiths Musical Sophistication Index, the Goldsmiths Dance Sophistication Index, the Beat and Meter Sensitivity Task, and a modified short version of the Profile for Music Perception Skills. Our results reveal that measures of perceptual abilities, musical training, and social dancing predicted the difference in groove rating between high- and low-groove music. Overall, these findings support the notion that listeners’ individual experiences and predispositions may shape their perception of musical groove, although other causal directions are also possible. This research helps elucidate the correlates and possible causes of musical groove perception in a wide range of listeners.

In a previous paper, we solved the partial differential equation of Mullins’ problem in the case of the evaporation–condensation in electronic devices and gave an exact solution relative to the geometric profile of the grain boundary grooving when materials are submitted to thermal and mechanical solicitation and fatigue effect. In this new research, new modelling of the grain groove profile was proposed and new analytical expressions of the groove profile, the derivative and the groove depth were obtained in the case of diffusion in thin polycrystalline films by the resolution of the fourth differential equation formulated by Mullins that supposed y′2≪1. The obtained analytical solution gave more accurate information on the geometric characteristics of the groove that were necessary to study the depth and the width of the groove. These new findings will open a new way to study with more accuracy the problem of the evaporation–condensation combined to the diffusion phenomenon on the material surfaces with the help of the analytical solutions.

Copyright of Turkish Journal of Trauma & Emergency Surgery / Ulusal Travma ve Acil Cerrahi Dergisi is the property of KARE Publishing 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 contribution examines groove dynamics across various spatial contexts such as the dance club and the artistic performance space. As groove dynamics do not occur in a spatial vacuum but are embedded in affective environments, they need to be approached from an interdisciplinary perspective that ties together findings from experimental field studies, performance studies, musicology, cognitive hermeneutics etc. and places them in the physical, anatomic and acoustic contexts of concrete dance situations. In that way, the dance floor can be understood as a space of entanglements where acoustic, movement and kinaesthetic grooves mark and create a fluid territory of improvisational interaction and communication.

Mechanical seals in centrifugal pumps used in various industrial equipment are critical components in preventing leakage of process fluid. Heat is generated at the working interface of the stationary and rotating rings due to friction. This study presents a numerical investigation to evaluate the thermal characteristics of the stationary and rotating seals during running conditions due to friction heat generation at the seal interface. The developed three-dimensional numerical model of the mechanical seal is compared with results published in the literature. An improved seal design is proposed for the stationary ring to increase the thermal efficiency and operational life of the seal. The seal interface temperature is reduced for the redesigned grooved stationary seal ring, thereby enhancing thermal performance. A comparison of the performance of the redesigned stationary ring is conducted with the conventional seal design to evaluate the effect of rotational speeds of the rotating ring and spring pressures. The thermal efficiency of the grooved stationary ring is higher by 16% than the original design. The improved seal design lowers the ring surface temperature by 10.5 °C compared to the conventional design. The proposed design is expected to improve the seal reliability of the seal with a longer operational life by reducing seal failure. [ABSTRACT FROM AUTHOR]

Motivation for bodily movement, physical activity and exercise varies from moment to moment. These motivation states may be "affectively-charged," ranging from instances of lower tension (e.g., desires, wants) to higher tension (e.g., cravings and urges). Currently, it is not known how often these states have been investigated in clinical populations (e.g., eating disorders, exercise dependence/addiction, Restless Legs Syndrome, diabetes, obesity) vs. healthy populations (e.g., in studies of motor control; groove in music psychology). The objective of this scoping review protocol is to quantify the literature on motivation states, to determine what topical areas are represented in investigations of clinical and healthy populations, and to discover pertinent details, such as instrumentation, terminology, theories, and conceptual models, correlates and mechanisms of action. Iterative searches of scholarly databases will take place to determine which combination of search terms (e.g., "motivation states" and "physical activity"; "desire to be physically active," etc.) captures the greatest number of relevant results. Studies will be included if motivation states for movement (e.g., desires, urges) are specifically measured or addressed. Studies will be excluded if referring to motivation as a trait. A charting data form was developed to scan all relevant documents for later data extraction. The primary outcome is simply the extent of the literature on the topic. Results will be stratified by population/condition. This scoping review will unify a diverse literature, which may result in the creation of unique models or paradigms that can be utilized to better understand motivation for bodily movement and exercise. [ABSTRACT FROM AUTHOR]

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING 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.)

Listening to samba percussion often elicits feelings of pleasure and the desire to move with the beat—an experience sometimes referred to as "feeling the groove"- as well as social connectedness. Here we investigated the effects of performance timing in a Brazilian samba percussion ensemble on listeners' experienced pleasantness and the desire to move/dance in a behavioral experiment, as well as on neural processing as assessed via functional magnetic resonance imaging (fMRI). Participants listened to different excerpts of samba percussion produced by multiple instruments that either were "in sync", with no additional asynchrony between instrumental parts other than what is usual in naturalistic recordings, or were presented "out of sync" by delaying the snare drums (by 28, 55, or 83 ms). Results of the behavioral experiment showed increasing pleasantness and desire to move/dance with increasing synchrony between instruments. Analysis of hemodynamic responses revealed stronger bilateral brain activity in the supplementary motor area, the left premotor area, and the left middle frontal gyrus with increasing synchrony between instruments. Listening to "in sync" percussion thus strengthens audio-motor interactions by recruiting motor-related brain areas involved in rhythm processing and beat perception to a higher degree. Such motor related activity may form the basis for "feeling the groove" and the associated desire to move to music. Furthermore, in an exploratory analysis we found that participants who reported stronger emotional responses to samba percussion in everyday life showed higher activity in the subgenual cingulate cortex, an area involved in prosocial emotions, social group identification and social bonding. [ABSTRACT FROM AUTHOR]

This research was conducted to observe the effect of adding grooves in the two-phase flow of water-air in the same direction through a vertical pipe to changes in pressure and fluid flow patterns. Test section in the form of pipes with grooves made of acrylic material with a length of 100 cm and an internal diameter of 2.54 cm. The geometric shape of the acrylic pipe is modified by giving a groove in the direction of the pipe along the test section. Grooves used amounted to 4 and 16 and pipes without grooves used as a comparison. Tests are carried out by flowing water and air that has been mixed through the inlet side upward. The ratio of air velocity to water velocity (VG / VL ) is 0.24-1.13. The method used in this study is experimental. Retrieval of pressure drops data is done by using a differential pressure transmitter. Visual observations are also made using a DSLR camera equipped with a flash and video observations using a smartphone with slow-motion mode. The results showed changes in flow patterns and pressure drop values. Slugs in pipes with grooves disappear faster and pressure drops are lower than pipes without grooves.