Search

BackgroundProper helmet fit is an important consideration for preventing head injuries, including concussions, in helmeted sports like youth ice hockey and ringette. Helmet fit assessments are typically completed in-person;however, this was not possible given COVID-19 restrictions. Thus, alternative considerations for virtual assessments were required.ObjectiveTo examine the feasibility and inter-rater reliability of virtual ice hockey and ringette helmet fit assessments.DesignCross-sectional.SettingCalgary, Canada.ParticipantsElite/upper division youth (ages 13–18) ice hockey (n=31 males) and ringette (n=30 females) players.Assessment of Risk FactorsStandardized ice hockey/ringette helmet fit criteria were developed and reliable for in-person assessments. Criteria were adapted for virtual delivery to participants over ZOOM video platform individually by two trained assessors per sport.Main Outcome MeasurementsTwelve helmet fit criteria scored as yes/proper fit or no/poor fit were used to assess helmet shell fit (e.g., helmet fits snug, doesn’t cover eyes), positioning (e.g., helmet is 1–2 finger widths above eyebrows, covers base of skull), facemask fit (e.g., chin piece fits, facemask does not move left/right), and others. Percent agreement (PA) between raters was used to describe inter-rater reliability, and each rater documented barriers for completing the assessments virtually.ResultsAcceptable PA (>80%) was demonstrated for 8/12 criterion for ice hockey and 9/12 for ringette. Below acceptable agreement was found for all four criterion assessing the helmet facemask fit (PA range: 48%-74%) in ice hockey players and criteria for the chin straps fit (PA=66%), helmet positioning (PA=73%), and facemask fit (PA=63%) in ringette players. Common barriers were related to technology (e.g., audio/video quality) and environment (e.g., noisy, lighting).ConclusionsVirtual helmet fit assessments are feasible and reliable for most criteria, with more training required for criteria below acceptable agreement. Virtual assessments provides another option for assessing helmet fit for concussion prevention in helmeted sports.

Low-cost aluminum (Al) metallization process on p+ side of n-type silicon (Si) substrate with low recombination current density (J0met) is presented. Narrow-line Al screen-printed fingers on symmetrically passivated p+ -n-p+ Si precursors with local contact opening (LCO) are investigated. The Si content of the Al pastes, LCO patterns and Al finger widths are varied to evaluate the formation quality of the Al-doped p+ region. By increasing the pitch distance of the dot-shaped LCOs, the inverted pyramid cavities are found after removing the Al-Si eutectic part by HCl. The tendency of the reaction during the sintering process is controlled by fritting the Al paste with Si, which allows a faster Si saturation in the paste matrix and facilitates faster return of Si to the LCO region. With a combination of narrow-line fingers of 90 μm and a dot-shaped LCO pitch of 140 μm, J0met value of 420 fA/cm2 is realized.

In this work various capacitive transduction schemes have been evaluated by performing numerical solution using COMSOL Multiphysics. Seven different schemes were evaluated by keeping the printed sensor finger widths up to 200µm and the same interspacing between these electrodes. The geometrical structure of transduction electrodes of the sensor directly relates to the sensitivity of the sensor and its performance. Our findings suggest that customized triangular arrow electrode configuration provides high transduction signals and is suitable for many aassensina applications and environmental sensors.

We numerically evaluate permeable heterogeneity effects on gravity-driven miscible porous media flows relevant to underground CO${}_{2}$ storage. For typical finger widths below correlation length we find largest variation measures among random realizations, and lowest mean due to the resonant effect.

This article gives a summary of the 8th Metallization and Interconnection workshop and attempts to place each contribution in the appropriate context. The field of metallization and interconnection continues to progress at a very fast pace. Several printing techniques can now achieve linewidths below 20 µm. Screen printing is more than ever the dominating metallization technology in the industry, with finger widths of 45 µm in routine mass production and values below 20 µm in the lab. Plating technology is also being improved, particularly through the development of lower cost patterning techniques. Interconnection technology is changing fast, with introduction in mass production of multiwire and shingled cells technologies. New models and characterization techniques are being introduced to study and understand in detail these new interconnection technologies.

The metallization grid pattern is one of the most important design elements for high-efficiency solar cells. This paper presents a model based on the unit cell approach to accurately quantify the power losses of a specialized interdigitated metallization scheme for polycrystalline silicon thin-film solar cells on glass superstrates. The sum of the power losses can be minimized to produce an optimized grid-pattern design for a cell with specific parameters. The model is simulated with the standard parameters of a polycrystalline silicon solar cell, and areas for efficiency improvements are identified, namely, a reduction in emitter finger widths and a shift toward series-interconnected, high-voltage modules with very small cell sizes. Using the model to optimize future grid-pattern designs, higher cell and module efficiencies of such devices can be achieved.

Thyromental distance (TMD) measurement is commonly used to predict difficult intubation. We surveyed anaesthetists to determine how this test was being performed. Comparative accuracy of ruler measurement and other forms of measurement were also assessed in a meta-analysis of published literature. Of respondents, 72% used fingers for TMD measurement and also considered three finger widths the minimum acceptable TMD. In terms of distance, the minimum acceptable TMD was felt to be 6.5 cm by 55% of respondents. However, the actual width of three fingers was (range) 4.6-7.0 cm (mean 5.9 cm), with significant differences between genders and between proximal and distal interphalangeal joints. The meta-analysis showed ruler measurement increased test sensitivity (48% (95% CI 43-53) vs 16% (95% CI 14-19) without a ruler), when predicting difficult intubation.

A pMOS transistor can be used as an electrostatic discharge (ESD) protection device; however, due to its higher turn-on resistance, it has a poor ESD robustness than that of nMOS transistors. Nevertheless, for a high-voltage (HV) p-channel laterally-diffused MOS (pLDMOS), which has a low impact-ionization rate, almost a non-snapback phenomenon (high V h value) and then with a high latch-up (LU) immunity. What is happening if a pLDMOS embedded with an HV silicon-controlled rectifier (ESCR)? In this paper, a novel HV pLDMOS-ESCR is proposed by implanted an extra N+ diffusion region in the drain-side among a pLDMOS. Meanwhile, the location of the N+ diffusion region is changed in order to investigate the impact on ESD capability. And, in this work, three different unit finger widths will be evaluated. Eventually, the I t2 value of “pnp”-type among HV pMOS-ESCR will be four times higher than that of “npn”-type at least, in the same time, the V h value of “pnp”-type HVpMOS-ESCR higher than that of “npn”-type, too. Therefore, the “pnp”-type HV pLDMOS-ESCR structure is an excellent structure in the HV technology due to its high ESD and latch-up immunities.

To date, physiotherapists have relied upon the use of finger widths for measurement of rectus abdominis diastasis (RAD). This method has been proven unreliable, due to variations in finger widths. The intra-rater reliability of dial calipers for measurement of RAD was investigated by this study, using a repeated measures design. Measurements were taken at rest and during contraction on three occasions in 30 postpartum subjects. High reliability was demonstrated for resting and active RAD measurements, (ICC = 0.93 and 0.95 respectively). In conclusion, dial calipers are a reliable measuring device when used by a single clinician. Further testing is required to determine inter-rater reliability.

An increased inter-rectus distance (IRD) is a common condition in late pregnancy and in the postnatal period. The condition is difficult to assess. Palpation is the most commonly used method to assess IRD. To date there is scant knowledge of intra and inter-tester reliability of palpation to measure IRD and how palpation compares with ultrasound measurements. The aims of this study were: 1) evaluate intra and inter-rater reliability of abdominal palpation; 2) validate abdominal palpation of IRD measurements using ultrasound imaging as a reference. Two physiotherapists (PTs) conducted the palpation study in random order, blinded to each other's assessments. IRD was measured as finger widths between the two rectus abdominis (RA) muscles. Ultrasound images were recorded at the same locations as the palpation test. A blinded investigator measured the IRD offline. Palpation showed good intra-rater reliability between days expressed by a weighted Kappa (wK) higher than 0.7 for both physiotherapists, and moderate inter-rater reliability (wK = 0.534). Ultrasound was found to be more responsive for differences in IRD compared with values obtained by palpation. The intra-rater reliability was higher than the inter-rater reliability. Besides the difference in experience with palpation testing between the PTs, this result may be due to differences in finger width and/or the subjective interpretation of abdominal soft-tissues pressure. Ultrasound measures are highly sensitive to changes of IRD, which is not possible to replicate by palpation assessment using a finger width scale. Palpation has sufficient reliability to be used in clinical practice. However, ultrasound is a more accurate and valid method and is recommended in future research of IRD.

An efficient algorithm, suitable for simulating both dispersive and non-dispersive interdigital transducer delay-lines in the time domain, has been proposed. Several characteristics of the transducers have been incorporated into the algorithm, including: metallic finger widths, overlapping finger lengths, the ▿(υ)/υ effect, inter-electrode reflections, and reflections from the ends of the delay-lines. Several simulated examples showing the usefulness of the algorithm are also given.

The COM parameters of EWC and Quadrature (Quad) SPUDT cells have been calculated for various h/λ and finger widths. A peak in reflectivity occurring at narrow finger width has been found on cuts of LiNbO3 (LN). An Enhanced EWC type SPUDT cell has been created by optimizing the position and width of the individual fingers resulting in a substantial increase in reflectivity while maintaining high piezoelectric coupling. The Enhanced cells have been employed in the design of sev- eral tapered SPUDT filters. Results are presented showing a typical reduction in triple transit of 8 to 10 dB due to an increase in SPUDT reflectivity of nearly 50%. The results confirm the practicality of the Enhanced cells.

SAW dispersive delay line with a novel IDT of variable finger widths and spacings has been manufactured and measured. It was found that it achieve very close agreement with the required parameters.

Two- and three-dimensional laboratory experiments were conducted in a large 1 by 1 m 2 Hele–Shaw cell and a 10-cm cylinder column to study the stability of the redistribution process in a uniformly packed porous medium of coarse sand. Our results demonstrate that fingers form and propagate rapidly as soon as infiltration stops when the soil is initially dry, but form more slowly and are larger when the soil is wet. Finger widths ranged from about 4.5 cm when the soil was dry to 17 cm when the soil was very wet, and the fraction of the cross-sectional area occupied by fingers also increased (from 36 to 66%). Finger velocities declined with time in all studies, with averages ranging from 3.6 to 9.6 cm min −1 . We demonstrated that ponded infiltration was stable and uniform in our system, so that the fingering we observed was not due to soil heterogeneity. The porous medium retained a memory of the fingers formed in the first experiment, so fingers formed in subsequent redistribution cycles followed the old finger paths, even after 28 d had elapsed. Fingers provide channels for rapid drainage of previously infiltrated water, especially when the soil ahead of the front is dry. Our findings clearly contradict predictions made by the Richards equation, which calculates stable flow during redistribution in homogeneous soil.

The effect that connate water has on fingers of water penetrating into an oil-wet porous medium is examined. In this context, the connate water appears to have no influence on the width of fingers, but instead causes the fingers to be more irregular than fingers in similar experiments without connate water. The surface wettability, in contrast, does have a marked effect on finger widths.

Using a sand-tank model and the salt-sugar system, double-diffusive fingers formed in a saturated porous medium. In contrast to the quasi-steady fingering typically observed in a viscous fluid, the fingering here was quite unsteady. The fingers’ structure was observed, and measurements of the sugar flux indicate that double-diffusive groundwater fingers can transport solutes at rates as much as two orders of magnitude larger than those associated with molecular diffusion in motionless groundwater. The buoyancy-flux ratio, r = αFT/βFS, increased from r = 0.65 ± 0.02 (at Rρ = 1.02) to r = 0.81 ± 0.06 (at Rρ = 1.50), where Rρ is the density-anomaly ratio. (Using the salt-sugar system in a viscous fluid, r was previously shown to decrease with increasing Rρ.) The buoyancy flux due to sugar varied approximately as R−5.6ρ, which is almost identical with the variation found for salt-sugar fingers in a viscous fluid. The model of Green (1984) was applied to the experiments and predicted buoyancy-flux ratios and finger widths that were in fairly good agreement with the measured values, although the predicted buoyancy fluxes due to sugar were significantly larger than the measured fluxes.

In this paper we present an approach to achieve both 100 mg paste deposit on a c-Si solar cell and efficiency gains with no impact on peel strength at extremely narrow finger widths. Using the double print process with suitable pastes and screens we demonstrate an 0.18% absolute efficiency gain and 20% paste saving over the standard process. This benefit is correlated to the finger width reduction from 63 μm to 47 μm, leading to an increase in Isc and Voc, due to the reduced recombination area under the metal contacts. The peel strength is also shown to increase from 1.5 N to 3 N for the same busbar thickness, when different paste compositions for the DP process are used. We also show screen lifetimes above 30k prints in production, with a stable process in terms of efficiency gain and paste saving.

Experimental results are presented on the magnetostatic-surface wave (MSSW) scattering properties of a grating of metal fingers placed at a variable height above the YIG film and compared with theory. The agreement with theory is excellent if one takes into account energy storage at the metal-finger edges and if the width of the metal fingers is larger than the YIG-film thickness. It is concluded that, for smaller finger widths, the interaction between the edges of a metal finger must additionally be incorporated into the theory. The present results are significantly different from those for the scattering of magnetostatic forward volume waves (MSFVW's) by a grating of metal fingers. In the latter case, the scattered modes are propagating MSFVW's so that the problem of interaction between the edges of metal fingers is not present, i.e., the theory is valid for all widths of the metal fingers.

We present complete results for the selected width of Saffman-Taylor fingers at large velocities with and without anisotropy in the surface tension. We solve a nonlinear eigenvalue problem to obtain the scaling laws and constants relating finger width, surface tension, and anisotropy. Excellent agreement with McLean's numerical solution of the full isotropic problem is obtained. The effect of anisotropy is to allow all finger widths. We discuss the relevance of these results to recent experimental findings.

To the Editor: I have a comment concerning the article “Interrater Reliability of Diastasis Recti Abdominis Measurement,” in the July issue of Physical Therapy (67:1077–1079, 1987). The author stated that the modified postpartum exercise for separation of recti muscles of three or more finger widths is a partial sit-up with the scapulae clearing the floor. It is my understanding that the modified exercise consists of a head raise only while in a supine position with knees bent, crossing the hands over the abdominal area so as to pull the muscles toward the midline. Raising only your head and not your shoulders and trunk activates just the superficial abdominal muscles that have separated. If the shoulders are raised off the floor, the deeper abdominal muscles will contract, causing an increase in the separation. This information can be found in Noble's Essential Exercises for the Childbearing Year , page 62. [ ARTICLE][1] [1]: /lookup/volpage/67/1077?iss=7