Condition Monitoring to Enable Predictive Maintenance on a Six-Die Nut Manufacturing Machine through Force Data Analysis

Nut fasteners are produced by machines working around the clock. Companies generally operate with a run-to-failure or planned maintenance approach. Even with a planned maintenance schedule, however, undetected damage to the dies and non-die parts occurring between maintenance periods can cause considerable downtime and pervasive damage to the machine. To address this shortcoming, force data from the fourth and sixth dies of a six-die nut manufacturing machine were analysed using correlation to the best health condition on the force profile and on the force shock response spectrum profile. Fault features such as quality adjustments and damage to both die and non-die parts were detectable prior to required maintenance or machine failure. This detection was facilitated by the determination of health thresholds, whereby the force SRS profile generated a longer warning period prior to failure. The analytical approach could benefit the industry by identifying damage that would normally go undetected by operators, thereby reducing downtime, extending die life, enabling “as needed” maintenance, and optimising machine operation.

Deceleration Training in Team Sports: Another Potential ‘Vaccine’ for Sports-Related Injury?

High-intensity horizontal decelerations occur frequently in team sports and are typically performed to facilitate a reduction in momentum preceding a change of direction manoeuvre or following a sprinting action. The mechanical underpinnings of horizontal deceleration are unique compared to other high-intensity locomotive patterns (e.g., acceleration, maximal sprinting speed), and are characterised by a ground reaction force profile of high impact peaks and loading rates. The high mechanical loading conditions observed when performing rapid horizontal decelerations can lead to tissue damage and neuromuscular fatigue, which may diminish co-ordinative proficiency and an individual’s ability to skilfully dissipate braking loads. Furthermore, repetitive long-term deceleration loading cycles if not managed appropriately may propagate damage accumulation and offer an explanation for chronic aetiological consequences of the ‘mechanical fatigue failure’ phenomenon. Training strategies should look to enhance an athlete’s ability to skilfully dissipate braking loads, develop mechanically robust musculoskeletal structures, and ensure frequent high-intensity horizontal deceleration exposure in order to accustom individuals to the potentially damaging effects of intense decelerations that athletes will frequently perform in competition. Given the apparent importance of horizontal decelerations, in this Current Opinion article we provide considerations for sport science and medicine practitioners around the assessment, training and monitoring of horizontal deceleration. We feel these considerations could lead to new developments in injury-mitigation and physical development strategies in team sports.

Change in force profile of the hardstyle kettlebell swing in older adults is small following 16 weeks of training and may not be required to improve physical function: findings from the BELL trial

Background. Hardstyle kettlebell training is characterised by the ballistic two-handed kettlebell swing with outcomes believed to be strongly influenced by swing proficiency. This study examines the effect of four months hardstyle kettlebell training on the force profile of the two-handed kettlebell swing, and peak ground reaction force during a kettlebell deadlift in older adults. These data will help inform healthcare providers and coaches about the use and prescription of kettlebell exercises with older adults. Methods. Five males and five females <70 years of age who participated in the BELL trial were recruited. Two-handed hardstyle swings were performed with 8-16 kg, and deadlifts with 8-32 kg. Ground reaction force (GRF) was obtained from a floor-mounted force platform. Force-time curves (FTCs), peak force, forward force relative to vertical force, rate of force development (RFD), and swing cadence were investigated. Results were compared with the same data variables collected from the participants in an exploratory pre-intervention study, conducted approximately seven months before the present study. Participants completed approximately 90 kettlebell training sessions during a four-month training intervention. Results. Participants used kettlebells to perform 3779 ± 802 swings, 923 ± 251 cleans, 825 ± 309 snatches and 744 ± 178 deadlifts during group-training sessions. Peak ground reaction force during kettlebell swings did not significantly change with any kettlebell weight. There was a significant 3% increase in the magnitude of forward force during 8 kg swings, and a significant 3% decrease in forward force during 16 kg swings. There were large significant improvements in swing cadence with a mean increase of three swings per minute and a small non-significant increase in RFD. Change in kettlebell swing force-time curve profiles were small. Change in peak ground reaction force during deadlifts were moderate to large. All participants increased in grip strength following training, with the magnitude of change greater than the minimum clinically important difference for seven participants. All participants had significant increases in multiple secondary outcomes. Conclusion. Group-based and online kettlebell training is likely to be ineffective for improving the force profile of the hardstyle kettlebell swing in older adults. Insufficiently active older adults engaged in high-volume kettlebell training performed 3-5 times weekly, can however expect to see clinically meaningful improvements in health-related physical fitness irrespective of swing proficiency, and have increased confidence with heavy lifting tasks. Results of this study suggest that beyond safe and competent performance, striving to optimise hardstyle swing technique may provide no additional benefit to clinical outcomes in older adults.

Electromotive force in the solar wind

The concept of electromotive force appears in various electromagnetic applications in geophysical and astrophysical fluids. A review of the electromotive force and its applications to the solar wind are discussed such as the electromotive force profile during the shock crossings and the observational tests for the mean-field model against the solar wind data. The electromotive force is being recognized as serving as a useful tool to construct a more complete picture of space plasma turbulence when combined with the energy spectra and helicity profiles.

The Influence of Mechanical Deformations on Surface Force Measurements

Surface Force Balance (SFB) experiments have been performed in a dry atmosphere and across an ionic liquid, combining the analysis of surface interactions and deformations, and illustrate that the mechanical deformations of the surfaces have important consequences for the force measurements. First, we find that the variation of the contact radius with the force across the ionic liquid is well described only by the Derjaguin–Muller–Toporov (DMT) model, in contrast with the usual consideration that SFB experiments are always in the Johnson–Kendall–Roberts (JKR) regime. Secondly, we observe that mica does not only bend but can also experience a compression, of order 1nm with 7μm mica. We present a modified procedure to calibrate the mica thickness in a dry atmosphere, and we show that the structural forces measured across the ionic liquid cannot be described by the usual exponentially decaying harmonic oscillation, but should be considered as a convolution of the surface forces across the liquid and the mechanical response of the confining solids. The measured structural force profile is fitted with a heuristic formulation supposing that mica compression is dominant over liquid compression, and a scaling criterion is proposed to distinguish situations where the solid deformation is negligible or dominant.

Collapsible fluid-filled fabric shock absorber with constant force

Energy absorption is an important challenge shared by multiple different industries including manufacturing, transportation, and protective equipment. This paper presents a novel shock absorption system based on woven fabrics designed to fully collapse and absorb energy at a near-minimum force level. The proposed system exerts an approximately constant force across different impact velocities. This system utilizes a fixed-orifice hydraulic shock absorber with variable contact area over its displacement to provide a nearly-constant force which scales with impact energy. Using analytical fluid dynamics, the contact area needed to produce a constant minimum force is derived. A finite element model of this shock absorber is created to validate the concept. Different impact conditions are simulated. The results confirm that the proposed fabric shock absorber is capable of producing a nearly-constant force across different impact energies. In simulation, the fabric shock absorber follows the ideal constant force profile with an averaged efficiency of 77.8% ± 3.4% which is far above standard foams which have efficiency of only approximately 20%–40%. The proposed system is compared with a cylindrical damper to show performance improvements gained through variable area geometry. Potential applications of this technology include soft devices for space-constrained applications such as contact sport helmets.

Strategy For Cellulase Immobilization And Its Partial Purification And Characterization

Conversion of cellulose to glucose units by cellulases, called hydrolysis, is a very complex step in ethanol production. It requires the mixing of aqueous suspensions of cellulose/cellulases so that cellulases (majority composed of the active site domain and the binding site domain) can attach to cellulose chains, cut or hydrolyze ß(1-4) glycosidic bonds between glucose units, de-attach and move to another location. Mixing extent (insufficient or excessive agitation) might influence the attachment of cellulases and possibly lead to lower glucose yields. A long-term goal of this research is to determine the strength of mixing required to be applied during the cellulose-cellulase mixing cycle. For that purpose, one of the objectives was to purify CBH I exocellulase from the commercial cellulase mixture. A partial purification of the CBH I that was performed on a much smaller scale with uncontrolled flow rate was successful. Another objective was to propose a scheme that would covalently immobilize CBH I exoceullase via its active site domain (ASD) on an atomic force microscopy-compatible support, a silicon support. A theoretically-developed hypothetical scheme was constructed (with the provided detailed procedure). The approach of immobilizing the inhibitor specific to the ASD of CBH I enzyme led to the possibility that no purification of CBH I could be required. Skipping CBH I purification step would save time and hassle associated with purification step. Once the ASD of CBH I is immobilized on a silicon support, the AFM force profile between the free-floating CDB and substrate cellulose could be established.

Strategy For Cellulase Immobilization And Its Partial Purification And Characterization

Conversion of cellulose to glucose units by cellulases, called hydrolysis, is a very complex step in ethanol production. It requires the mixing of aqueous suspensions of cellulose/cellulases so that cellulases (majority composed of the active site domain and the binding site domain) can attach to cellulose chains, cut or hydrolyze ß(1-4) glycosidic bonds between glucose units, de-attach and move to another location. Mixing extent (insufficient or excessive agitation) might influence the attachment of cellulases and possibly lead to lower glucose yields. A long-term goal of this research is to determine the strength of mixing required to be applied during the cellulose-cellulase mixing cycle. For that purpose, one of the objectives was to purify CBH I exocellulase from the commercial cellulase mixture. A partial purification of the CBH I that was performed on a much smaller scale with uncontrolled flow rate was successful. Another objective was to propose a scheme that would covalently immobilize CBH I exoceullase via its active site domain (ASD) on an atomic force microscopy-compatible support, a silicon support. A theoretically-developed hypothetical scheme was constructed (with the provided detailed procedure). The approach of immobilizing the inhibitor specific to the ASD of CBH I enzyme led to the possibility that no purification of CBH I could be required. Skipping CBH I purification step would save time and hassle associated with purification step. Once the ASD of CBH I is immobilized on a silicon support, the AFM force profile between the free-floating CDB and substrate cellulose could be established.

Review: Electromotive force in the solar wind

The concept of electromotive force appears in various electromagnetic applications in geophysical and astrophysical fluids. An overview of the electromotive force and its applications to the solar wind are discussed such as the electromotive force profile during the shock crossings and the observational tests for the mean-field model against the solar wind data. The electromotive force is being recognized as serving as a useful tool to construct a more complete picture of space plasma turbulence when combined with the energy spectra and helicity profiles.