A smartphone inertial balance

2017 ◽  
Vol 55 (4) ◽  
pp. 248-249
Author(s):  
Azael Barrera-Garrido
Keyword(s):  
Inertial Balance

A direct-reading inertial balance (teaching)

1978 ◽  
Vol 13 (4) ◽  
pp. 239-240 ◽  
Author(s):  
L Bruzzi
Keyword(s):  
Direct Reading ◽  
Inertial Balance

Performance Evaluation of Inertial Balance for Measuring Mass in Microgravity

2014 ◽  
Vol 38 (12) ◽  
pp. 1395-1401
Author(s):  
Hyun-Jin Jang ◽  
Joo-Hee Lee ◽  
Jae-Hyuk Choi ◽  
Seul-Hyun Park
Keyword(s):  
Performance Evaluation ◽  
Inertial Balance

scholarly journals Resonance Micro-Weighing of Sub-Picogram Mass with the Use of Adaptive Interferometer

2014 ◽  
Vol 14 (3) ◽  
pp. 160-163 ◽  
Author(s):  
Roman Romashko ◽  
Timofey Efimov ◽  
Yuri Kulchin
Keyword(s):  
Mass Measurement ◽  
Mass Detection ◽  
Micromechanical Resonators ◽  
Microscopic Object ◽  
Macroscopic Object ◽  
Adaptive Interferometer ◽  
Alternative Approach ◽  
Dynamic Hologram ◽  
Adsorbed Mass ◽  
Inertial Balance

Abstract Mass of macroscopic object is easily measured by a suitable balance. However, this approach becomes inapplicable if mass of microscopic object is to be determined. Alternative approach for mass measurement is based on using the micromechanical resonator as an inertial balance where oscillation frequency is shifted by small quantities of adsorbed mass. In this work we present experimental results of applying an adaptive interferometry technique based on dynamic hologram recorded in photorefractive CdTe crystal for measuring picogram mass adsorbed on micromechanical resonators with dimensions 215×40×15 μm3. It is also shown that the resonance micro-weighing system based on adaptive interferometer has potential for reducing the threshold of mass detection down to 10-17 g in the case of using a resonator with sub-micron dimensions

scholarly journals Acute Sport-Related Concussion Screening for Collegiate Athletes Using an Instrumented Balance Assessment

2018 ◽  
Vol 53 (6) ◽  
pp. 597-605 ◽  
Author(s):  
Joshua Baracks ◽  
Douglas J. Casa ◽  
Tracey Covassin ◽  
Ryan Sacko ◽  
Samantha E. Scarneo ◽  
...  
Keyword(s):  
Root Mean Square ◽  
Collegiate Athletes ◽  
The United States ◽  
Group Differences ◽  
Control Group ◽  
Mean Square ◽  
Area Measure ◽  
Cutoff Value ◽  
Standard Deviations ◽  
Inertial Balance

Context:  Without a true criterion standard assessment, the sport-related concussion (SRC) diagnosis remains subjective. Inertial balance sensors have been proposed to improve acute SRC assessment, but few researchers have studied their clinical utility. Objective:  To determine if group differences exist when using objective measures of balance in a sample of collegiate athletes with recent SRCs and participants serving as the control group and to calculate sensitivity and specificity to determine the diagnostic utility of the inertial balance sensor for acute SRC injuries. Design:  Cross-sectional cohort study. Setting:  Multicenter clinical trial. Patients or Other Participants:  We enrolled 48 participants with SRC (age = 20.62 ± 1.52 years, height = 179.76 ± 10.00 cm, mass = 83.92 ± 23.22 kg) and 45 control participants (age = 20.85 ± 1.42 years, height = 177.02 ± 9.59 cm, mass = 74.61 ± 14.92 kg) at 7 clinical sites in the United States. All were varsity or club collegiate athletes, and all participants with SRC were tested within 72 hours of SRC. Main Outcome Measure(s):  Balance performance was assessed using an inertial balance sensor. Two measures (root mean square sway and 95% ellipse sway area) were analyzed to represent a range of general balance measures. Balance assessments were conducted in double-legged, single-legged, and tandem stances. Results:  A main effect for group was associated with the root mean square sway measure (F1,91 = 11.75, P = .001), with the SRC group demonstrating balance deficits compared with the control group. We observed group differences in the 95% ellipse sway area measure for the double-legged (F1,91 = 11.59, P = .001), single-legged (F1,91 = 6.91, P = .01), and tandem (F1,91 = 7.54, P = .007) stances. Sensitivity was greatest using a cutoff value of 0.5 standard deviations (54% [specificity = 71%]), whereas specificity was greatest using a cutoff value of 2 standard deviations (98% [sensitivity = 33%]). Conclusions:  Inertial balance sensors may be useful tools for objectively measuring balance during acute SRC evaluation. However, low sensitivity suggests that they may be best used in conjunction with other assessments to form a comprehensive screening that may improve sensitivity.

Transient natural convection flows around a thin fin on the sidewall of a differentially heated cavity

2009 ◽  
Vol 639 ◽  
pp. 261-290 ◽  
Author(s):  
FENG XU ◽  
JOHN C. PATTERSON ◽  
CHENGWANG LEI
Keyword(s):  
Natural Convection ◽  
Numerical Simulations ◽  
Flow Regime ◽  
Direct Numerical Simulations ◽  
Scaling Relations ◽  
Scaling Analysis ◽  
Transient Natural Convection ◽  
Inertial Flow ◽  
Inertial Balance ◽  
Energy Balances

Transient natural convection flows around a thin fin on the sidewall of a differentially heated cavity, which includes a lower intrusion under the fin, a starting plume bypassing the fin and a thermal flow entrained into the vertical thermal boundary layer downstream of the fin in a typical case, are investigated using a scaling analysis and direct numerical simulations. The obtained scaling relations show that the thickness and velocity of the transient natural convection flows around the fin are determined by different dynamic and energy balances, which can be either a buoyancy-viscous balance or a buoyancy-inertial balance, depending on the Rayleigh number, the Prandtl number and the fin length. A time scale of the transition from a buoyancy-viscous flow regime to a buoyancy-inertial flow regime is obtained. The major scaling relations quantifying the transient natural convection flows are also validated by direct numerical simulations. In general, there is a good agreement between the scaling predictions and the corresponding numerical results.

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