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Cancer metastasis is still a major social issue with limited knowledge of the formation of tumors and their growth. In addition the formation of metastases is very difficult to understand, since it involves very complex physical mechanisms such as cellular interactions and cell rheology, which are flow-dependent. Previous studies investigated transendothelial migration using sophisticated techniques such as microfluidics, traction force microscopy (TFM) or Atomic Force Microscopy (AFM), combined with physical modeling. Here we summarize recent results and suggest new ways to investigate the precise mechanisms used by cancer cells to undergo transendothelial migration. [ABSTRACT FROM AUTHOR]

The use of biodegradable or green composites has been increasing exponentially due to the growing environmental concern. Though these composites are fabricated to near-neat shape but milling is an unavoidable machining operation that is required for removing undesired material to meet the design necessities. In this study, the milling behavior of green composites (polylactic acid/bamboo) fabricated using compression molding has been extensively studied by investigating the induced forces, temperature, and surface roughness. The process parameters of milling operation such as spindle speed (500, 710, 1400, and 2000 RPM), feed rate (80, 112, 160, and 224 mm/min), depth of cut (0.5, 1, 1.5, and 2 mm), and milling cutters (slot and end mill cutters) have been optimized through Taguchi analysis for obtaining minimum milling-induced forces, temperature, and surface roughness. The relative significance of each process parameter has also been found through the analysis of variance. Milling cutter and depth of cut are the two parameters found to have significant contributions in determining the quality of the milling surface. Lower milling-induced force, temperature, and surface roughness can be obtained by selecting a lower depth of cut and end mill cutter during the milling of green composites. [ABSTRACT FROM AUTHOR]

The study of machine parts movements required by inertial forces is actually a dynamic problem. The machine parts in motion are under dynamic stress due to the inertial forces that appear and overlap the directly applied forces and also connection forces. In the paper, the movements that are studied from a dynamic point of view are those that involve acceleration. [ABSTRACT FROM AUTHOR]

Industries have been pursuing a competent machining strategy that fulfills the necessity of sustainability without deteriorating tool wear or final product quality of components made from difficult-to-cut material Titanium 64. This article attempts a combination ultrasonic vibration with vegetable oil-based cutting fluid (VCF), to increases the tool life and machinability of Titanium 64. In-house developed Ultrasonic-assisted turning (UAT) setup for vibration, and emulsion of 10% Canola oil for cooling, are used. The machinability in respect of cutting and feed force, tool-chip contact length, and flank and crater wear, are examined. As a result, the UAT under VCF offers a reduction in tool-chip contact length by 12–45%, cutting force by 10–25%, and feed force by 20–40%. Moreover, ultrasonic-assisted turning using vegetable oil-based cutting fluid also decreases the adhesion and abrasion wear from the rake face, which is obvious in the conventional turning process of Titanium 64. [ABSTRACT FROM AUTHOR]

Nowadays, there is a high demand for rapid prototyping parts and for products manufactured through plastic cold deformation. Incremental forming process is one of many which presents numerous advantages for fast production of complex shape parts. The purpose of this study is to develop a numerical model through finite element analysis to simulate the incremental forming process. For this analysis a variable wall angle part (VWA) which ranges from a 45° wall angle at the higher base of frustrum cone to a 70° wall angle at the base of the shape was proposed. The numerical model showed where the maximum strains are localized, how big the forces are during the process and how much the material thinned. Although the model does not indicate a possible failure of the material, the integrity of the structural stiffness was altered due to a minimum thickness reached of just 0.26mm. [ABSTRACT FROM AUTHOR]

Introduction. Bodybuilding is a sport that requires all muscle groups to be similarly developed, bringing an aesthetic physique to the observers. The development of the triceps surae may be a difficult goal to achieve for some athletes. Considering this, we chose to focus on a new training method that induces less stress in muscle groups: the time under tension. Objective. The purpose of the study was to compare exercises used for calf hypertrophy using the time under tension method and to identify the optimal situations in which this method could be used. Methods. Ten subjects, 6 male and 4 female, age of 25.7±4.9 years old, height 174.7±9.5 centimeters, body weight 82±17.8 kg and with varied levels of fitness, participated in the study. The plantar flexions were done with body weight only on one and both feet. The exercises we tested were done on a 3 second cycle: 3 seconds on the upwards movement and 3 seconds for the downwards one. The subjects performed a total of 10 repetitions for each exercise. Results. A significant statistical difference was found between the types of plantar flexion measured. This indicates that the analysis of time under tension plantar flexion should take into account the actual type of movement done. Conclusions. Time under tension method for calf muscle hypertrophy should take into consideration the movement characteristics for the focused muscle group. Our results showed that postural balance and body position can influence the force and power output of plantar flexion. [ABSTRACT FROM AUTHOR]

Cutting using an abrasive water jet is a complex process involving several physical phenomena. This research studies some of them, mostly the influence of selected variables on the measured forces and vibrations. The traverse speed represents one of the key parameters when cutting using the AWJ. In the presented research, a set of experiments was performed on twelve different metal samples, while the force sensor measured the exerted forces and accelerometers measured the vibrations. Ten different types of steel samples of the same dimensions were cut applying five different traverse speeds. The data obtained during these measurements show that an increase in the traverse speed leads to an increase in the measured forces and vibrations. An analogous experiment performed on bronze and duralumin samples of the same dimensions, having applied higher speeds to compensate for the difference in the material structure and properties, completes the presented data. The most important results of the research are that exerted forces in the z-axis are higher than those in the x-axis, whereas measured vibrations are higher in the x-axis. According to our research, the elemental structure, especially the carbide formation, affects the measured forces and vibrations substantially. [ABSTRACT FROM AUTHOR]

The present article studies the resistance opposed to the pulling force in injection pultrusion processes and its dependence on polymerization of the resin. A methodology to evaluate and analyze the local resistance to the advancement of the composite is proposed. Injection pultrusion processes were conducted adopting four different advancing speeds, equal to 100, 140, 180, and 220 mm/min. The interaction of the traveling material with the die has been analyzed and discussed referring to the temperature distribution and resin transitions evaluated by a finite element model. Numerical and experimental outcomes highlighted that the kinetic and rheological aspects in pultrusion are strictly dependent on the advancing velocity. Higher speeds determine an increase of the resistant force and reduction in the final degree of cure of the resin system. Detrimental effects on the quality of profiles pultruded at higher speed are demonstrated as well. [ABSTRACT FROM AUTHOR]

Magnesium alloys generate harmful emissions while using coolants during the machining process and it affects both the operator and the environment. Ultrasonic vibration assisted turning (UVAT) is an eco-friendly and advanced machining process to machine various materials than conventional turning (CT). In this study, experimental analysis is carried out to investigate the machinability of the magnesium AZ31B alloy during CT and UVAT processes. The effect of cutting speed during the processing of magnesium AZ31B alloy is analyzed and compared with CT in terms of machining forces, machining temperature, tool wear, chip morphology, surface roughness, microstructure, and microhardness. Results showed that compared with CT, machining forces and surface roughness is reduced significantly in UVAT. However, higher machining temperature is obtained during UVAT than CT. Flank wear is observed during CT although negligible tool wear is observed for UVAT. Chip segmentation is obtained for both CT and UVAT whereas higher chip thickness is observed for UVAT than CT process. Finer grains and higher microhardness are obtained in UVAT than the coarse grains and lower microhardness in CT. The results showed that the processing of magnesium AZ31B alloy during the UVAT process leads to enhanced machining performance compared to the CT process. [ABSTRACT FROM AUTHOR]

Muscle tendon unit fibre mechanics of hamstring and adductor strain injuries are not well studied, with factors such as fatigue promoted as risk factors in the absence of mechanistic evidence. In this study, musculoskeletal modelling was used to estimate fibre mechanics of four hamstring (biceps femoris long head, biceps femoris short head, semimembranosus and semitendinosus) and four adductor (adductor brevis, adductor longus, adductor magnus and gracilis) muscles during an anticipated cut task. The cut task was performed by 10 healthy elite male U20 basketball players both before and immediately after they played in one (of four) competitive basketball game. Biceps femoris long head produced significantly lower (p = 0.032) submaximal force post-game in the latter part of swing (30.7% to 35.0% of stride), though its peak force occurred later (37%) and remained unchanged. Semimembranosus produced significantly lower (p = 0.006) force post-game (32.9% to 44.9% of stride), which encompassed the instance of peak force (39%). Neither fibre velocity nor fibre length of the investigated muscles were significantly affected by game-play. These finding suggest that if fatigue is a factor in hamstring and adductor muscle strain injuries and is brought about by game-play, it is unlikely through the fibre mechanisms investigated in this study. [ABSTRACT FROM AUTHOR]

External load variables such as peak tibial acceleration (PTA), peak vertical ground reaction forces (GRF) and its instantaneous vertical loading rate (IVLR) may contribute to running injuries although evidence is conflicting given the influence of training load and tissue health on injuries. These variables are influenced by footwear, speed, surface and foot strike pattern during running. The purpose of this study was to assess the influence of four surfaces and two running speeds on external load variables in rearfoot strike (RFS) runners. Twelve RFS runners (confirmed with sagittal foot contact angle) completed a 2-min running bout on a treadmill and 50-m running bouts over the three surfaces (pavement, rubber track and grass) in standardised shoes at their preferred speed and 20% faster. PTA and vertical GRFs were collected using inertial measurement units and in-shoe force insoles. No interaction or surface effects were observed (p > 0.017). The faster speed produced greater axial PTA (+19.2%; p < 0.001), resultant PTA (+20.7%; p < 0.001), peak vertical GRF (+6.6%; p = 0.002) and IVLR (+16.5%; p < 0.001). These findings suggest that surface type does not influence PTA, peak vertical GRF and IVLR but that running faster increases the magnitude of these external loads regardless of surface type in RFS runners. [ABSTRACT FROM AUTHOR]

Non-ergonomic execution of repetitive physical tasks represents a major cause of work-related musculoskeletal disorders (WMSD). This study was focused on the pushing and pulling (P&P) of an industrial handcart (which is a generic physical task present across many industries), with the aim to investigate the dependence of P&P execution on the operators' psychological status and the presence of pain syndromes of the upper limbs and spine. The developed acquisition system integrated two three-axis force sensors (placed on the left and right arm) and six electromyography (EMG) electrodes (placed on the chest, back, and hand flexor muscles). The conducted experiment involved two groups of participants (with and without increased psychological scores and pain syndromes). Ten force parameters (for both left and right side), one EMG parameter (for three different muscles, both left and right side), and two time-domain parameters were extracted from the acquired signals. Data analysis showed intergroup differences in the examined parameters, especially in force integral values and EMG mean absolute values. To the best of our knowledge, this is the first study that evaluated the composite effects of pain syndromes, spine mobility, and psychological status of the participants on the execution of P&P tasks—concluding that they have a significant impact on the P&P task execution and potentially on the risk of WMSD. The future work will be directed towards the development of a personalized risk assessment system by considering more muscle groups, supplementary data derived from operators' poses (extracted with computer vision algorithms), and cognitive parameters (extracted with EEG sensors). [ABSTRACT FROM AUTHOR]

The use of filtering facepiece respirators (FFRs) of various types increased dramatically by both workers and the public during the ongoing COVID-19 pandemic. This increased use has, likewise, instigated a proliferation of research on the qualities of FFRs. An aspect of FFR development and optimization involves the use of mathematical models that predict filter efficiency based on various filter characteristics while also considering a number of particle capture forces. An evaluation of current literature failed to identify a publication that provides a comprehensive assessment of the models developed to predict filter efficiency. The purpose of this review was, therefore, to describe models developed to include the forces associated with diffusion, interception, impaction, and electrostatic attraction as they contribute to the efficiency of an entire filter. The literature review was augmented with figures created with the use of many of the models discussed to compare different models of the same force as well as to illustrate the influence of electrostatic forces on overall filter efficiency. [ABSTRACT FROM AUTHOR]

This study aims to determine optimal forming parameters for Incremental Sheet Forming process Commercially Pure titanium Grade 2 sheets in terms of formability improvement, force reduction, and efficiency of forming. Based on the central composite design, data were collected during 20 runs and then variation analysis was performed. The experiments were performed on a 3 axis CNC milling machine equipped with a Kistler dynamometer plate. Subsequently, regression models have been developed to describe process responses by input factors. As crucial parameters, the relative velocity and step size of the tool that affect the forming force and the height of the fracture have been determined. Finally, the application of optimization algorithm has emerged optimal input factors in terms of selected multi-criteria goal. The results of this study suggest that there is a process window that allows the formation of 45° wall angle drawpieces of commercially pure titanium Grade 2. [ABSTRACT FROM AUTHOR]

Background. The link between frequency domain analysis of ground reaction forces and hearing loss and blindness during walking is not well understood. Therefore, the purpose of this study was to investigate the frequency domain analysis of ground reaction forces in deaf and blind people during walking. Methods. This study was quasi-experimental. The volunteer participants in the current study consisted of thirty males who were divided into three equal groups: blind, deaf, and healthy (control) groups. Frequency domain analysis of ground reaction forces in three groups was recorded by a foot scan system (sample rate: 300 Hz). The multivariate ANOVA test was used to compare between groups. The significance level was set at P

Depuis son élection en 2019, le président ukrainien Volodymyr Zelensky travaille pour l’intégration de l’Ukraine à l’Union Européenne ainsi que son adhésion à l’OTAN. Ceci impliquerait l’intervention des pays membres de l’OTAN en faveur de l’Ukraine en cas d’agression militaire. Cependant, la Russie s’oppose à cette perspective étant donné l’impact géopolitique d’une telle décision. Elle craint donc une éventuelle adhésion ukrainienne à l’OTAN, qu’elle voit comme une organisation concurrente menaçant sa sécurité, ainsi que le rapprochement des anciennes républiques soviétiques d’Europe avec l’Union Européenne. Ainsi, pour faire face à la persistance de l’Ukraine, la Russie a depuis le 24 février dernier, lancé une série d’opérations militaires de grande envergure sur le territoire ukrainien. Aux yeux de l’Union Européenne qui a une politique étrangère et de la sécurité commune instituée par le Traité de Maastricht de 1992, l’intervention militaire russe en Ukraine déstabilise profondément l’ordre de sécurité international et européen. En réaction, le Conseil Européen a pris une multitude des sanctions à l’endroit de la Russie, en dépit desquelles la crise s’intensifie provoquant beaucoup de dégâts matériels et des lourdes pertes en vies humaines. C’est pourquoi l’objectif de notre recherche est d’analyser les forces et faiblesses de l’ONU dans le conflit russo-ukrainien.

Depuis son élection en 2019, le président ukrainien Volodymyr Zelensky travaille pour l’intégration de l’Ukraine à l’Union Européenne ainsi que son adhésion à l’OTAN. Ceci impliquerait l’intervention des pays membres de l’OTAN en faveur de l’Ukraine en cas d’agression militaire. Cependant, la Russie s’oppose à cette perspective étant donné l’impact géopolitique d’une telle décision. Elle craint donc une éventuelle adhésion ukrainienne à l’OTAN, qu’elle voit comme une organisation concurrente menaçant sa sécurité, ainsi que le rapprochement des anciennes républiques soviétiques d’Europe avec l’Union Européenne. Ainsi, pour faire face à la persistance de l’Ukraine, la Russie a depuis le 24 février dernier, lancé une série d’opérations militaires de grande envergure sur le territoire ukrainien. Aux yeux de l’Union Européenne qui a une politique étrangère et de la sécurité commune instituée par le Traité de Maastricht de 1992, l’intervention militaire russe en Ukraine déstabilise profondément l’ordre de sécurité international et européen. En réaction, le Conseil Européen a pris une multitude des sanctions à l’endroit de la Russie, en dépit desquelles la crise s’intensifie provoquant beaucoup de dégâts matériels et des lourdes pertes en vies humaines. C’est pourquoi l’objectif de notre recherche est d’analyser les forces et faiblesses de l’ONU dans le conflit russo-ukrainien.

In the current study, the wear behavior of bronze-bonded grinding tools when grinding the titanium alloy Ti-6Al-4V was explored. In this process, oxidation plays a key role since both the bronze bond and the titanium workpiece chemically react with oxygen. The oxidation effect is intensified further due to increased temperatures during grinding and can cause tribo-oxidation. This wear effect can be reduced or even eliminated by grinding in an extreme high-vacuum (XHV) adequate atmosphere. This atmosphere is nearly oxygen-free and is generated using a silane-doped argon gas that chemically reacts with oxygen. This reaction is able to decrease the oxygen partial pressure (pO2 ≤ 10−12 mbar) down to an XHV-adequate atmosphere. The aim of this paper is to investigate the influence of oxygen in the atmosphere on the application and wear behavior during grinding and to demonstrate the potential of this novel approach. The results presented show that during grinding with cBN, the process forces are significantly influenced by the atmosphere. Depending on the process parameters, a reduction of up to 93% is thus possible. This force reduction correlates with radial tool wear. When grinding under oxygen-free conditions, it can be reduced by up to 64%.

BACKGROUND: Orthopedic tractions can be employed in the rehabilitation of patients suffering from problems affecting the spine, as well as the upper and lower extremities but the high costs of using tractions due to prolonged hospital stays is a major disadvantage particularly in low-income economies. OBJECTIVE: The objective of this study was to design and develop a two-way adjustable traction system that accommodates both cervical and lower limb rehabilitation and improves limb and neck positioning. METHOD: The production process involved the use of computer-aided design (CAD) as well as other manufacturing procedures like material selection, welding, and drilling. The system was tested for stability to be sure it does not fail under large loads. RESULT: A functional and easy-to-install two-way orthopedic traction system for both hospital and home use was developed, installed and tested. The dimensions and adjustability would ensure that it can be used for children and adults. CONCLUSION: This study describes a device that can be used in hospitals. When used at homes, it can reduce the cost of medical bills, and provide patients with the emotional/psychological benefits of being cared for in a familiar environment. [ABSTRACT FROM AUTHOR]

Since inline monitoring method has the advantages of no sampling, being real-time, no human intervention, and low error, this paper innovatively proposes to study the inline monitoring of wear particles in an oil pipeline, from the perspective of the different motion characteristics of the particles. In this paper, an inline optical sensor was designed and developed by studying the velocity characteristics of different particles through theoretical calculations, numerical simulations, and experimental analysis. First, an equation for particle motion was statistically established, based on the forces acting on wear particles in an oil-filled vertical tube. Then a finite element model of particle motion in a full-flow oil pipeline was created, to simulate particle motion with various diameters, densities, locations, and shapes. Finally, the results of the theoretical study were effectively applied to design an inline optical monitoring sensor, and the experimental validation results demonstrated that the inline sensor has excellent suitability for monitoring wear particles. This study has significance for the safe operation of large rotating machinery. [ABSTRACT FROM AUTHOR]

Aluminum alloys of various series are used extensively in the auto and aviation sectors because of their low weight to strength ratio. In the current article, one of the hard-to-form aluminum alloys, i.e., AA2014-T6 investigated for its formability and microstructural changes in incremental forming at room and elevated temperature of 250OC. The mechanical properties and formability of the material are evaluated using uniaxial tensile test and Varying Wall Angle Cone Frustums (VWACF), respectively. A novel experimental setup is designed with an induction coil to heat the sheet at elevated temperatures for incremental forming. As-received sheets formed at room and elevated temperature of 250OC, showed less improvement in material formability due to less number of slip planes. Thus, the samples are solutionized at 480OC for 3 hours followed by aging at 180OC for 8 hours. However, much improvement was not observed in room temperature formability, even though the ductility was improved significantly. But, forming at an elevated temperature of 250OC, the formability was enhanced by 956% compared to the as-received material. The formability of the material is correlated with the microstructural modification after solution treatment at room and elevated temperatures. [ABSTRACT FROM AUTHOR]

Cellular and tissue biosystems emerge from the assembly of their constituent molecules and obtain a set of specific material properties. To measure these properties and understand how they influence cellular function is a central goal of mechanobiology. Froma bottoms-up, physics or engineering point-of-view, such systems are a composition of basic mechanical elements. However, the sheer number and dynamic complexity of them, including active molecular machines and their emergent properties, makes it currently intractable to calculate how biosystems respond to forces. Because many diseases result from an aberrant mechanotransduction, it is thus essential to measure this response. Recent advances in the technology of optical tweezers have broadened their scope from single-molecule applications to measurements inside complex cellular environments, even within tissues and animals. Here, we summarize the basic optical trapping principles, implementations and calibration procedures that enable force measurements using optical tweezers directly inside cells of living animals, in combination with complementary techniques. We review their versatility to manipulate subcellular organelles and measure cellular frequency-dependent mechanics in the piconewton force range from microseconds to hours. As an outlook, we address future challenges to fully unlock the potential of optical tweezers for mechanobiology. [ABSTRACT FROM AUTHOR]

Copyright of Apotheke is the property of Universidade do Estado de Santa Catarina 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.)

To better understand the rock breakage mechanism and optimize tool performance during rock machining by multidiameter combination saw, the rock processing experiment using a multidiameter combination saw was carried out on the bridge saw to investigate the variation of load with diameter in the combination saw. Furthermore, in this study, the sawing forces, tools wear, and rock breakage in the processing rock were qualitatively analyzed and compared. The experimental investigations demonstrated that the maximum undeformed chip thickness, the load per diamond, and the load in the sawing arc zone all decrease with increasing diameters of the single saw in the combination saw. The sum of the vertical forces of the single saw is generally less than that of the combination saw under the same parameters because of the existence of the coupling effect between the single saws. Different failure mechanisms of particles in the worn segment of the tool with different diameters also operate in rock processing using a multidiameter combination saw. With increasing diameter of saw blade, the proportion of the whole and blunt diamond particles increases, and that of the macro-fractured and pulled-out crystals decreases. Moreover, the differences in the surface integrity are attributed to the variation in the maximum undeformed chip thickness on the saw blade with different diameters in the combination saw and the gully depth on the surface, and the surface roughness of rock decreases with increasing diameter of the single saw. Highlights: The experiments for rock processing by a multidiameter combination saw are designed to investigate the sawing performance of multidiameter combination circular saw with different diameters. Different failure mechanisms of particles in the worn segment of the tool with different diameters operate in rock processing using a multidiameter combination saw. The differences in the surface integrity are attributed to the variation in the maximum undeformed chip thickness on the saw blade with different diameters in the combination saw. Coupling effect between the single saws affects decomposition and generation of forces in the multidiameter saw. [ABSTRACT FROM AUTHOR]

War in Afghanistan in new millennium is referred to America’s counter-terrorism operation in Afghanistan. It had threefold objective to dismantle Al- Qaeda’s safe heavens in Afghanistan, oust Taliban from power and combat terrorism in Afghanistan. Author has applied the International Alert Conflict Assessment Framework for the completion of this paper. Taliban defied their words to provide protection to women, girls, allow media to function, amnesty to former government employees and interpreters. After Taliban’s violent take over on August 15, 2021 targeted campaign was launched to kill civil society members, former government workers, prevent girls’ school education. Afghanistan today is the second country where girl’s secondary education is banned. The regime stopped women from working. Eighty five percent of women working in media have quit jobs. Former government employees e.g. police officials, judges, army officials are primary target of the repressive regime. Women workers, journalists, human rights defenders, ordinary and notable Afghans daring to raise voice against Taliban are under threat in Afghanistan. Coercive policies are creating psychological problems in the suppressed community particularly female. [ABSTRACT FROM AUTHOR]

Copyright of Logos: Anales del Seminario de Metafísica (1575-6866) is the property of Universidad Complutense de Madrid 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.)

Relevance of the research is determined by the need to understand modern achievements in modeling the processes of sludge transport in real conditions of drilling operations that increase drilling speed and the efficiency of well cleaning; to establish the advantages/disadvantages of existing approaches, modern models and complex methods for describing the dynamics of systems with particles in order to effectively choose the rheological properties of drilling fluids and eliminate the reasons of equipment loss. The aim of this work is to understand the modern experience of modeling the processes of cleaning wells with complex geometries, mainly lying in the horizontal plane; to study the features of the flow of mixtures in the annular space with a circular core; providing recommendations for the practice of modeling and calculating hydrodynamic processes that increase hole cleaning efficiency. Methodology. Theoretical and practical research methods from related fields of hydrodynamics and heat and mass transfer in rheologically and physically complex systems; methods for numerical modeling of laminar and turbulent flows under conditions of direct-flow and swirling flows created by a co-axially or orbitally rotating wall, which affect the formation of a layer of cuttings and the dynamics of particles of a dispersed mixture. Results. The paper introduces the results of modern numerical studies of cleaning wells with horizontal sections and the information on aspects of detailed hydrodynamic and diffusion modeling of complex flows in inclined wells. The applied models and methods used to study the characteristics of flow and heat and mass transfer in homogeneous and heterogeneous media in internal systems are formulated. Aspects of modeling the processes of cuttings transport in the framework of Euler/Lagrangian approaches are discussed, taking into account the features introduced by the effects of interfacial interaction/rotation. The paper introduces the changes in cuttings concentration based on rheological properties (power-law or Herschel–Bulkley), different shapes/sizes of particles, flow regimes and inertial forces. The problems of improving the accuracy of cuttings transport modeling, the possibilities of new technologies, original turbulence models and their two-parameter dynamic bases used for increasing the intensification and efficiency of cleaning processes are analyzed. The authors have given the recommendations for their solution in the considered hydrodynamic and geometric configurations. The results and problems that are of fundamental and applied significance and constitute an independent subject of prospective research are indicated.

The epithelium covers, protects, and actively regulates various formations and cavities of the human body. During embryonic development the assembly of the epithelium is crucial to the organoid formation, and the invasion of the epithelium is an essential step in cancer metastasis. Live cell mechanical properties and associated forces presumably play an important role in these biological processes. However, the direct measurement of cellular forces in a precise and high-throughput manner is still challenging. We studied the cellular adhesion maturation of epithelial Vero monolayers by measuring single-cell force-spectra with high-throughput fluidic force microscopy (robotic FluidFM). Vero cells were grown on gelatin-covered plates in different seeding concentrations, and cell detachment forces were recorded from the single-cell state, through clustered island formation, to their complete assembly into a sparse and then into a tight monolayer. A methodology was proposed to separate cell-substratum and cell-cell adhesion force and energy (work of adhesion) contributions based on the recorded force-distance curves. For comparison, cancerous HeLa cells were also measured in the same settings. During Vero monolayer formation, a significantly strengthening adhesive tendency was found, showing the development of cell-cell contacts. Interestingly, this type of step-by-step maturation was absent in HeLa cells. The attachment of cancerous HeLa cells to the assembled epithelial monolayers was also measured, proposing a new high-throughput method to investigate the biomechanics of cancer cell invasion. We found that HeLa cells adhere significantly stronger to the tight Vero monolayer than cells of the same origin. Moreover, the mechanical characteristics of Vero monolayers upon cancerous HeLa cell influence were recorded and analyzed. All these results provide insight into the qualitative assessment of cell-substratum and cell-cell mechanical contacts in mono- and multilayered assemblies and demonstrate the robustness and speed of the robotic FluidFM technology to reveal biomechanical properties of live cell assemblies with statistical significances.

The Lagrange formalism is developed for Bateman oscillators, which includes both damped and amplified systems, and a novel method to derive the Caldirola-Kanai and null Lagrangians is presented. For the null Lagrangians, the corresponding gauge functions are obtained. It is shown that the gauge functions can be used to convert the undriven Bateman oscillators into the driven ones. Applications of the obtained results to quantizatation of the Bateman oscillators are briefly discussed.

The forces that orient the spindle in human cells remain poorly understood due to a lack of direct mechanical measurements in mammalian systems. We use magnetic tweezers to measure the force on human mitotic spindles. Combining the spindle's measured resistance to rotation, the speed at which it rotates after laser ablating astral microtubules, and estimates of the number of ablated microtubules reveals that each microtubule contacting the cell cortex is subject to ∼5 pN of pulling force, suggesting that each is pulled on by an individual dynein motor. We find that the concentration of dynein at the cell cortex and extent of dynein clustering are key determinants of the spindle's resistance to rotation, with little contribution from cytoplasmic viscosity, which we explain using a biophysically based mathematical model. This work reveals how pulling forces on astral microtubules determine the mechanics of spindle orientation and demonstrates the central role of cortical dynein clustering. [Display omitted] • Cytoplasmic viscosity does not determine the spindle's resistance to rotation • Each astral microtubule contacting the cell cortex is pulled on by one dynein motor • Pulling forces on astral microtubules determine spindle orientation mechanics • Dynein motor clustering at the cell cortex controls spindle orientation mechanics The orientation of the mitotic spindle within the cell sets the division axis, which is a crucial aspect of tissue development. Anjur-Dietrich et al. show that the mechanics of spindle orientation is determined by clustering of dynein motors at the cell cortex, which exert pulling forces on astral microtubules. [ABSTRACT FROM AUTHOR]

Exoskeletons and exosuits have witnessed unprecedented growth in recent years, especially in the medical and industrial sectors. In order to be successfully integrated into the current society, these devices must comply with several commercialization rules and safety standards. Due to their intrinsic coupling with human limbs, one of the main challenges is to test and prove the quality of physical interaction with humans. However, the study of physical human–exoskeleton interactions (pHEI) has been poorly addressed in the literature. Understanding and identifying the technological ways to assess pHEI is necessary for the future acceptance and large-scale use of these devices. The harmonization of these evaluation processes represents a key factor in building a still missing accepted framework to inform human–device contact safety. In this review, we identify, analyze, and discuss the metrics, testing procedures, and measurement devices used to assess pHEI in the last ten years. Furthermore, we discuss the role of pHEI in safety contact evaluation. We found a very heterogeneous panorama in terms of sensors and testing methods, which are still far from considering realistic conditions and use-cases. We identified the main gaps and drawbacks of current approaches, pointing towards a number of promising research directions. This review aspires to help the wearable robotics community find agreements on interaction quality and safety assessment testing procedures. [ABSTRACT FROM AUTHOR]

This Account covers the recent progress made on heterocyclic mechanophores in the field of polymer mechanochemistry. In particular, the types of such mechanophores as well as the mechanisms and applications of their force-induced structural transformations are discussed and related perspectives and future challenges proposed. 1 Introduction 2 Types of Mechanophores 3 Methods to Incorporate Heterocycle Mechanophores into Polymer Systems 4 Mechanochemical Reactions of Heterocyclic Mechanophores 4.1 Three-Membered-Ring Mechanophores 4.2 Four-Membered-Ring Mechanophores 4.3 Six-Membered-Ring Mechanophores 4.4 Bicyclic Mechanophores 5 Applications 5.1 Cross-Linking of Polymer 5.2 Degradable Polymer 5.3 Mechanochromic Polymer 6 Concluding Remarks and Outlook [ABSTRACT FROM AUTHOR]

Bordelon, NM, Jones, DH, Sweeney, KM, Davis, DJ, Critchley, ML, Rochelle, LE, George, AC, and Dai, B. Optimal load magnitude and placement for peak power production in a vertical jump: A segmental contribution analysis. J Strength Cond Res 36(4): 911-919, 2022-Weighted jumps are widely used in power training, however, there are discrepancies regarding which loading optimizes peak jump power. The purpose was to quantify the effects of load magnitudes and placements on the force, velocity, and power production in a countermovement vertical jump. Sixteen male and 15 female subjects performed vertical jumps in 7 conditions: no external load, 10 and 20% dumbbell loads, 10 and 20% vest loads, and 10 and 20% barbell loads with load percentages relative to body weight. Arm swing was encouraged for all, but the barbell load conditions. Kinematics were collected to quantify the whole-body (the person and external loads) forces, velocities, and power as well as segments' contributions to the whole-body forces and velocities. Repeated-measure analyses of variance were performed followed by paired comparisons. Jump heights were the greatest for the no external load and 10% dumbbell conditions. The 10 and 20% dumbbell conditions demonstrated the greatest peak whole-body power, while the 2 barbell conditions showed the lowest peak whole-body power. At the time of peak whole-body power, the 2 dumbbell and 2 vest conditions resulted in greater whole-body forces. Whole-body velocities were the greatest for the no external load and 10% dumbbell conditions. Holding the dumbbells in the hands magnified the effects of external loads in producing forces and velocities. The constraint of arm movements in the barbell conditions limited power production. These findings highlight the importance of load placement and arm swing in identifying the optimal configuration for power production in weighted jumps. [ABSTRACT FROM AUTHOR]

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The regulation of mitotic spindle position and orientation, and consequent division plane specification, is critical for early embryo development, tissue architecture and stem cells. Accordingly, defects in spindle positioning have been associated with the emergence of tissue disorders and mis-specification of cell fates, causing the formation of tumors, for instance, in stem cell populations. In such context, methods to physically manipulate mitotic spindle position or orientation in living cells bear the promise of dissecting the causal impact of spindle mis-positioning on cell or tissue behavior. Here, we describe a method to directly modulate mitotic spindle position and orientation with in vivo magnetic tweezers in developing sea urchin embryos. This method allows for monitoring the impact of spindle orientation on embryo development and quantifying forces and torques needed to move or rotate spindles. It may be transposable to many other cell, embryo or tissue types., (© 2025. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

This paper examines the meaning potential of directed forces or vectors in cinema. The first part draws on the pioneering work of Rudolf Arnheim to highlight the prominent role of vectors in the visual structuring of meaning in paintings. In the second part, we move on to explore the semantic significance of motion vectors in cinema. To this aim we first define and diagram the filmic space in which vectors may articulate themselves visually. Having firmly grounded this spatial framework in film theory, we adopt the terminology of Herbert Zettl to further distinguish between three types of motion vectors: primary motion vectors (elicited by motion of visual objects), secondary motion vectors (elicited by camera movement) and tertiary motion vectors (elicited by editing). We conclude this paper by applying the proposed conceptual tools of this paper to three filmic case-studies in which the relation between narrative meaning and motion vectors is further discussed and illustrated.

For developing new areas of research in physics, chemistry, environment and mathematics, it is incumbent to study forces driving the amalgamation of nanoparticles and particles in solution. In solution, observing the live dynamics of colloidal entities is not an intriguing approach to study the forces driving their amalgamations. Different microscopic images of nanoparticles and particles can enable one to study the driven forces in amalgamation. In amalgamation of colloidal entities, forces of minimum two references are required. On development, a nanoparticle or particle not only conceives the force exerted due to the medium dynamics, but it also monitors the force originated due to its own features. The net force driving the amalgamation of a particle is resulted from at least two forces. During amalgamation, the net force exerted to the particle successively remains in mute, alert and functioning modes. The energy behavior successively remains in functioning, alert and mute modes. In amalgamation of geometric shapes, exerting force at the electron level remains in an even manner, which is not the case in amalgamation of distorted particles. On amalgamation of particles, agglomerates are formed, where force of mainly one reference influences. When amalgamating in the solution, nanoparticles and particles are the best candidates to trace the nature of forces, so they can also interpret the associated energy behaviors.