scholarly journals A Hydrodynamic Model for Measuring Fluid Density and Viscosity by Using Quartz Tuning Forks

Sensors ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 198 ◽  
Author(s):  
Mi Zhang ◽  
Dehua Chen ◽  
Xiao He ◽  
Xiuming Wang
Keyword(s):  
Resonance Frequency ◽  
Quality Factor ◽  
Hydrodynamic Model ◽  
Beam Theory ◽  
Cost Effective ◽  
Fluid Density ◽  
Index Method ◽  
Tuning Forks ◽  
Order Of Magnitude ◽  
Quartz Tuning Forks

A hydrodynamic model of using quartz tuning forks (QTFs) for density and viscosity sensing, by measuring the resonance frequency and quality factor, has been established based on the cantilever beam theory applied to the atomic force microscope (AFM). Two examples are presented to verify the usability of this model. Then, the Sobol index method is chosen for explaining quantitatively how the resonance frequency and quality factor of the QTFs are affected by the fluid density and viscosity, respectively. The results show that the relative mean square error in viscosity of the eight solutions evaluated by the hydrodynamic model is reduced by an order of magnitude comparing with Butterworth–Van Dyke equivalent circuit method. When the measured resonance frequency and quality factor of the QTFs vary from 25,800–26,100 Hz and 28–41, the sensitivities of the quality factor affected by the fluid density increase. This model provides an idea for improving the accuracy of fluid component recognition in real time, and lays a foundation for the application of miniaturized and cost-effective downhole fluid density and viscosity sensors.

scholarly journals Influence of Tuning Fork Resonance Properties on Quartz-Enhanced Photoacoustic Spectroscopy Performance

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3825 ◽  
Author(s):  
Huadan Zheng ◽  
Haoyang Lin ◽  
Lei Dong ◽  
Yihua Liu ◽  
Pietro Patimisco ◽  
...  
Keyword(s):  
Resonance Frequency ◽  
Quality Factor ◽  
Photoacoustic Spectroscopy ◽  
Electrical Resistance ◽  
Tuning Fork ◽  
Resonance Frequencies ◽  
Resonance Properties ◽  
Tuning Forks ◽  
Quartz Tuning Forks ◽  
Fundamental Resonance Frequency

A detailed investigation of the influence of quartz tuning forks (QTFs) resonance properties on the performance of quartz-enhanced photoacoustic spectroscopy (QEPAS) exploiting QTFs as acousto-electric transducers is reported. The performance of two commercial QTFs with the same resonance frequency (32.7 KHz) but different geometries and two custom QTFs with lower resonance frequencies (2.9 KHz and 7.2 KHz) were compared and discussed. The results demonstrated that the fundamental resonance frequency as well as the quality factor and the electrical resistance were strongly inter-dependent on the QTF prongs geometry. Even if the resonance frequency was reduced, the quality factor must be kept as high as possible and the electrical resistance as low as possible in order to guarantee high QEPAS performance.

scholarly journals Quartz tuning forks resonance frequency matching for laser spectroscopy sensing

2022 ◽  
pp. 100329
Author(s):  
Yufei Ma ◽  
Yinqiu Hu ◽  
Shunda Qiao ◽  
Ziting Lang ◽  
Xiaonan Liu ◽  
...  
Keyword(s):  
Resonance Frequency ◽  
Laser Spectroscopy ◽  
Frequency Matching ◽  
Tuning Forks ◽  
Quartz Tuning Forks

Pound Wise and Penny Foolish? Weight Loss and The Dynamics of Health Care Spending

2011 ◽  
Vol 14 (2) ◽  
Author(s):  
Thomas G Koch
Keyword(s):  
Weight Loss ◽  
Cost Savings ◽  
Cost Effective ◽  
Economic Consequences ◽  
Health Care Spending ◽  
Order Of Magnitude ◽  
Dynamic Measures ◽  
The Cost ◽  
The Impact ◽  
The Relationship

Current estimates of obesity costs ignore the impact of future weight loss and gain, and may either over or underestimate economic consequences of weight loss. In light of this, I construct static and dynamic measures of medical costs associated with body mass index (BMI), to be balanced against the cost of one-time interventions. This study finds that ignoring the implications of weight loss and gain over time overstates the medical-cost savings of such interventions by an order of magnitude. When the relationship between spending and age is allowed to vary, weight-loss attempts appear to be cost-effective starting and ending with middle age. Some interventions recently proven to decrease weight may also be cost-effective.

Simulation of blast waves with tailored explosive charges

1985 ◽  
Vol 158 ◽  
pp. 137-152
Author(s):  
M. Sanai ◽  
H. E. Lindberg ◽  
J. D. Colton
Keyword(s):  
Shock Tube ◽  
Charge Density ◽  
Cost Effective ◽  
Development Programme ◽  
Blast Waves ◽  
Charge Density Distribution ◽  
Test Conditions ◽  
Order Of Magnitude ◽  
Explosive Charges ◽  
Simulation Time

We have developed a compact and cost-effective shock tube to simulate the static and dynamic pressures of blast waves. The shock tube is open at both ends and is driven by high explosives distributed over a finite length of the tube near one end. The overall charge length is determined by the simulation time of interest, and the charge-density distribution is tailored to produce the pressure-waveform shape desired. For the shock tube to simulate a typical blast wave, the charge density must be highest at the charge front (closest to the test section) and gradually reduced towards the back. The resulting shock tube is an order of magnitude shorter than a conventional dynamic airblast simulator (DABS) in which concentrated explosives are used to drive the shock.Tailored charges designed using this method were built and tested in a simulation development programme sponsored by the U.S. Defense Nuclear Agency (DNA). The pressures measured for several charge distributions agreed very well with SRI's PUFF hydrocode computations and demonstrated the feasibility of the compact simulator under realistic test conditions.

scholarly journals Mutual interactions of oscillating quartz tuning forks in superfluid 4He

2013 ◽  
Vol 39 (10) ◽  
pp. 823-827 ◽  
Author(s):  
G. Sheshin ◽  
I. Gritsenko ◽  
D. Schmoranzer ◽  
L. Skrbek
Keyword(s):  
Superfluid 4He ◽  
Tuning Forks ◽  
Quartz Tuning Forks

Measuring the Prong Velocity of Quartz Tuning Forks Used to Probe Quantum Fluids

2010 ◽  
Vol 161 (5-6) ◽  
pp. 536-547 ◽  
Author(s):  
D. I. Bradley ◽  
P. Crookston ◽  
M. J. Fear ◽  
S. N. Fisher ◽  
G. Foulds ◽  
...  
Keyword(s):  
Quantum Fluids ◽  
Tuning Forks ◽  
Quartz Tuning Forks

scholarly journals Comparative evaluation of cost effective extraction free molecular technique for detection of SARS-CoV-2 with reference to standard VTM based RT-qPCR method

2021 ◽  
Author(s):  
Megh Singh Dhakad ◽  
Sanjib Gogoi ◽  
Ansu Kumari ◽  
Aashish Kumar Singh ◽  
Manoj B. Jais ◽  
...  
Keyword(s):  
Detection Method ◽  
Cost Effective ◽  
Molecular Technique ◽  
Rt Pcr ◽  
Index Method ◽  
Resource Limited ◽  
Qpcr Method ◽  
Kappa Value ◽  
The Cost ◽  
Higher Sensitivity

Background and Objectives: The entire globe is undergoing an unprecedented challenge of COVID-19. Considering the need of rapid and accurate diagnostic tests for SARS-CoV-2, this study was planned to evaluate the cost effective extraction free RT-PCR technique in comparison to the standard VTM based RT-qPCR method. Materials and Methods: Paired swabs from nasopharynx and oropharynx were collected for SARS-CoV-2 testing, from 211 adult patients (≥18 years) in VTM and plain sterile tubes (dry swabs). These samples were processed and RT-qPCR was carried out as per standard protocols. Results: 54.5% of the patients were females and 45.5% were males with sex ratio 1:1.19 (M: F). 38.86% were symptomatic, of which fever (86.59%), cough (79.23%) and breathlessness (46.34%) were the most common symptoms. The positivity by VTM based method and index method was 31.27% and 13.27% respectively. Of the 27 inconclusive results from index method, 37.04% were positive, 48.15% were negative by VTM based method. However, in 40 inconclusive results by VTM based method, 90% were negative and rest remained inconclusive by index method. The sensitivity and specificity of the index method were 39.39% and 85.71% respectively. The overall agreement between VTM based method and index method was 49.59% with estimated Kappa value of 0.19. Conclusion: VTM based method showed higher sensitivity compared to the index method. The higher positivity by VTM based method, suggests that VTM based method could plausibly be a better detection method of SARS-CoV-2. Still, the index method might add value in a resource limited setups for detection of SARS-CoV-2.  

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