Performing Fourier Transform on a Velocity Profile From Atmospheric Turbulence Studies

2021 ◽  
Author(s):  
Richard Adansi ◽  
Jose Terrazas ◽  
Arturo Rodriguez ◽  
V. M. Krushnarao Kotteda ◽  
Vinod Kumar ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Velocity Profile ◽  
Size Distribution ◽  
Atmospheric Turbulence ◽  
Situational Awareness ◽  
Control Volume ◽  
The United States ◽  
Vertical Distance ◽  
Large Eddy ◽  
Computational Fluid Dynamics Cfd

Abstract Atmospheric Turbulence poses a challenge to land-based observatories operated by the United States Air Force (USAF) tasked with space situational awareness. By developing new methods for quantifying Turbulence, we intend to provide increased USAF capability in this domain. Current models for quantifying atmospheric Turbulence include Kolmogorov and Non-Kolmogorov methods. Through the nature of Fourier Transform, sinusoidal function, it is possible to determine the frequency at which velocities occur in a specified vertical distance and eventually determine eddy size in a control volume. First, an ANSYS Computational Fluid Dynamics (CFD) model will be created to simulate atmospheric Turbulence in a defined control volume. The simulation will include a one-dimensional flow over a flat plate. The data we acquired from the simulation were used to derive an equation relating the velocity to the vertical distance (velocity profile). We will perform a regression analysis to fit data from Large-Eddy Simulations (LES) and apply Fourier transformation from a time domain to a frequency domain. The objective is to use Fourier transform analysis to determine eddy size distribution and turbulent cascade dissipation in a control volume by analyzing the frequency of velocities. By calculating such eddy size distribution, we may quantify Turbulence in said control volume and compare results with the traditional Kolmogorov method.

Parameter Sensitivity and Statistical Correlation Found in Atmospheric Turbulence Studies

2020 ◽  
Author(s):  
Luis F. Rodriguez ◽  
Vinod Kumar ◽  
Arturo Rodriguez ◽  
V. M. Krushnarao Kotteda ◽  
V. S. Rao Gudimetla ◽  
...  
Keyword(s):  
Turbulent Flow ◽  
Atmospheric Turbulence ◽  
Control Volume ◽  
Large Eddy Simulations ◽  
Index Structure ◽  
Cfd Modeling ◽  
Optical Parameters ◽  
Cfd Modelling ◽  
Area Of Interest ◽  
Large Eddy

Abstract We have simulated atmospheric turbulence at several instances of possible laser propagation paths and turbulent flow regime regions within the area of interest. At a control volume that is in between two Hawaii mountains. We have applied statistical correlations between Large-Eddy Simulations results using CFD modeling and parametrizing optical variables of interest, such as refractive index structure function. By comparing our Large-Eddy Simulations with specified parameters against other Large-Eddy Simulations with almost all same parameters except for one allows us to perform a sensitivity study. To study the changes on how a parameter can affect other scenarios of Large-Eddy Simulations parametric studies. With the end goal of validating the capacity of a sensitivity analysis study using Large-Eddy Simulations versus other Large-Eddy Simulations by a way of simulating and parametrizing turbulent flow studies found in the field of CFD modeling. Allowing us to achieve our stochastic analysis by applying sensitivity studies to see how our distributions change as a function of different parameters, but one at a time. After a comparison between CFD modelling simulations we have found that after a complete parametric study, a correlation was formed between turbulent flow parameters and optical parameters of interest.

scholarly journals Fourier Transform Infrared Spectroscopy in Oral Cancer Diagnosis

2021 ◽  
Vol 22 (3) ◽  
pp. 1206
Author(s):  
Rong Wang ◽  
Yong Wang
Keyword(s):  
Cancer Research ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Oral Cancer ◽  
Fourier Transform Infrared Spectroscopy ◽  
Diagnostic Tool ◽  
Unmet Need ◽  
Fourier Transform Infrared ◽  
The United States ◽  
Easy Access

Oral cancer is one of the most common cancers worldwide. Despite easy access to the oral cavity and significant advances in treatment, the morbidity and mortality rates for oral cancer patients are still very high, mainly due to late-stage diagnosis when treatment is less successful. Oral cancer has also been found to be the most expensive cancer to treat in the United States. Early diagnosis of oral cancer can significantly improve patient survival rate and reduce medical costs. There is an urgent unmet need for an accurate and sensitive molecular-based diagnostic tool for early oral cancer detection. Fourier transform infrared spectroscopy has gained increasing attention in cancer research due to its ability to elucidate qualitative and quantitative information of biochemical content and molecular-level structural changes in complex biological systems. The diagnosis of a disease is based on biochemical changes underlying the disease pathology rather than morphological changes of the tissue. It is a versatile method that can work with tissues, cells, or body fluids. In this review article, we aim to summarize the studies of infrared spectroscopy in oral cancer research and detection. It provides early evidence to support the potential application of infrared spectroscopy as a diagnostic tool for oral potentially malignant and malignant lesions. The challenges and opportunities in clinical translation are also discussed.

scholarly journals Description and Derived Climatologies of Automated In Situ Eddy-Dissipation-Rate Reports of Atmospheric Turbulence

2014 ◽  
Vol 53 (6) ◽  
pp. 1416-1432 ◽  
Author(s):  
R. D. Sharman ◽  
L. B. Cornman ◽  
G. Meymaris ◽  
J. Pearson ◽  
T. Farrar
Keyword(s):  
Atmospheric Turbulence ◽  
Dissipation Rate ◽  
Route Planning ◽  
Federal Aviation Administration ◽  
The United States ◽  
Commercial Aircraft ◽  
Upper Troposphere ◽  
Obvious Benefit ◽  
Turbulence Data

AbstractThe statistical properties of turbulence at upper levels in the atmosphere [upper troposphere and lower stratosphere (UTLS)] are still not well known, partly because of the lack of adequate routine observations. This is despite the obvious benefit that such observations would have for alerting aircraft of potentially hazardous conditions, either in real time or for route planning. To address this deficiency, a research project sponsored by the Federal Aviation Administration has developed a software package that automatically estimates and reports atmospheric turbulence intensity levels (as EDR ≡ ε1/3, where ε is the energy or eddy dissipation rate). The package has been tested and evaluated on commercial aircraft. The amount of turbulence data gathered from these in situ reports is unprecedented. As of January 2014, there are ~200 aircraft outfitted with this system, contributing to over 137 million archived records of EDR values through 2013, most of which were taken at cruise levels of commercial aircraft, that is, in the UTLS. In this paper, techniques used for estimating EDR are outlined and comparisons with pilot reports from the same or nearby aircraft are presented. These reports allow calibration of EDR in terms of traditionally reported intensity categories (“light,” “moderate,” or “severe”). The results of some statistical analyses of EDR values are also presented. These analyses are restricted to the United States for now, but, as this program is expanded to international carriers, such data will begin to become available over other areas of the globe.

Large-Eddy Simulations of realistic atmospheric turbulence with the DLR-TAU-code initialized by in situ airborne measurements

2012 ◽  
Vol 66 ◽  
pp. 121-129 ◽  
Author(s):  
Torsten Auerswald ◽  
Jens Bange ◽  
Tobias Knopp ◽  
Keith Weinman ◽  
Rolf Radespiel
Keyword(s):  
Atmospheric Turbulence ◽  
Large Eddy Simulations ◽  
Airborne Measurements ◽  
Large Eddy

scholarly journals Safety huddles to proactively identify and address electronic health record safety

2016 ◽  
Vol 24 (2) ◽  
pp. 261-267 ◽  
Author(s):  
Shailaja Menon ◽  
Hardeep Singh ◽  
Traber D Giardina ◽  
William L Rayburn ◽  
Brenda P Davis ◽  
...  
Keyword(s):  
Situational Awareness ◽  
Tertiary Care ◽  
The United States ◽  
Care Hospital ◽  
Design Data ◽  
Software Application ◽  
Safety Concerns ◽  
Hardware System ◽  
Error Taxonomy ◽  
Electronic Health

Objective: Methods to identify and study safety risks of electronic health records (EHRs) are underdeveloped and largely depend on limited end-user reports. “Safety huddles” have been found useful in creating a sense of collective situational awareness that increases an organization’s capacity to respond to safety concerns. We explored the use of safety huddles for identifying and learning about EHR-related safety concerns. Design: Data were obtained from daily safety huddle briefing notes recorded at a single midsized tertiary-care hospital in the United States over 1 year. Huddles were attended by key administrative, clinical, and information technology staff. We conducted a content analysis of huddle notes to identify what EHR-related safety concerns were discussed. We expanded a previously developed EHR-related error taxonomy to categorize types of EHR-related safety concerns recorded in the notes. Results: On review of daily huddle notes spanning 249 days, we identified 245 EHR-related safety concerns. For our analysis, we defined EHR technology to include a specific EHR functionality, an entire clinical software application, or the hardware system. Most concerns (41.6%) involved “EHR technology working incorrectly,” followed by 25.7% involving “EHR technology not working at all.” Concerns related to “EHR technology missing or absent” accounted for 16.7%, whereas 15.9% were linked to “user errors.” Conclusions: Safety huddles promoted discussion of several technology-related issues at the organization level and can serve as a promising technique to identify and address EHR-related safety concerns. Based on our findings, we recommend that health care organizations consider huddles as a strategy to promote understanding and improvement of EHR safety.

scholarly journals Use of Emergency Department Data to Monitor and Respond to an Increase in Opioid Overdoses in New Hampshire, 2011-2015

2017 ◽  
Vol 132 (1_suppl) ◽  
pp. 73S-79S ◽  
Author(s):  
Elizabeth R. Daly ◽  
Kenneth Dufault ◽  
David J. Swenson ◽  
Paul Lakevicius ◽  
Erin Metcalf ◽  
...  
Keyword(s):  
Public Health ◽  
Emergency Department ◽  
New Hampshire ◽  
Syndromic Surveillance ◽  
Situational Awareness ◽  
The United States ◽  
Chief Complaint ◽  
Public Health Response ◽  
Syndromic Surveillance System ◽  
Icd Codes

Objectives: Opioid-related overdoses and deaths in New Hampshire have increased substantially in recent years, similar to increases observed across the United States. We queried emergency department (ED) data in New Hampshire to monitor opioid-related ED encounters as part of the public health response to this health problem. Methods: We obtained data on opioid-related ED encounters for the period January 1, 2011, through December 31, 2015, from New Hampshire’s syndromic surveillance ED data system by querying for (1) chief complaint text related to the words “fentanyl,” “heroin,” “opiate,” and “opioid” and (2) opioid-related International Classification of Diseases ( ICD) codes. We then analyzed the data to calculate frequencies of opioid-related ED encounters by age, sex, residence, chief complaint text values, and ICD codes. Results: Opioid-related ED encounters increased by 70% during the study period, from 3300 in 2011 to 5603 in 2015; the largest increases occurred in adults aged 18-29 and in males. Of 20 994 total opioid-related ED visits, we identified 18 554 (88%) using ICD code alone, 690 (3%) using chief complaint text alone, and 1750 (8%) using both chief complaint text and ICD code. For those encounters identified by ICD code only, the corresponding chief complaint text included varied and nonspecific words, with the most common being “pain” (n = 3335, 18%), “overdose” (n = 1555, 8%), “suicidal” (n = 816, 4%), “drug” (n = 803, 4%), and “detox” (n = 750, 4%). Heroin-specific encounters increased by 827%, from 4% of opioid-related encounters in 2011 to 24% of encounters in 2015. Conclusions: Opioid-related ED encounters in New Hampshire increased substantially from 2011 to 2015. Data from New Hampshire’s ED syndromic surveillance system provided timely situational awareness to public health partners to support the overall response to the opioid epidemic.

scholarly journals Liquid Films Falling Down a Vertical Fiber: Modeling, Simulations and Experiments

Fluids ◽  
2021 ◽  
Vol 6 (8) ◽  
pp. 281
Author(s):  
Yadong Ruan ◽  
Ali Nadim ◽  
Lekha Duvvoori ◽  
Marina Chugunova
Keyword(s):  
Velocity Profile ◽  
Liquid Film ◽  
Control Volume ◽  
Plug Flow ◽  
Traveling Wave Solutions ◽  
Liquid Films ◽  
Physical Experiments ◽  
Theoretical Predictions ◽  
Viscous Liquid Film ◽  
Linear Drag

We provide a new framework for analyzing the flow of an axisymmetric liquid film flowing down a vertical fiber, applicable to fiber coating flows and those in similar geometries in heat exchangers, water treatment, and desalination processes. The problem considered is that of a viscous liquid film falling under the influence of gravity and surface tension on a solid cylindrical fiber. Our approach is different from existing ones in that we derive our mathematical model by using a control-volume approach to express the conservation of mass and axial momentum in simple and intuitively appealing forms, resulting in a pair of equations that are reminiscent of the Saint-Venant shallow-water equations. Two versions of the model are obtained, one assuming a plug-flow velocity profile with a linear drag force expression, and the other using the fully-developed laminar velocity profile for a locally uniform film to approximate the drag. These can, respectively, model high- and low-Reynolds number regimes of flow. Linear stability analyses and fully nonlinear numerical simulations are presented that show the emergence of traveling wave solutions representing chains of identical droplets falling down the fiber. Physical experiments with safflower oil on a fishing line are also undertaken and match the theoretical predictions from the laminar flow model well when machine learning methods are used to estimate the parameters.

scholarly journals Nebulizer – In vitro Bioequivalence testing requirements: A review

1970 ◽  
Vol 8 (1) ◽  
pp. 78-81
Author(s):  
Shubham Prajapati ◽  
Sanjay Saha ◽  
B Shambulingappa ◽  
Dilip Kumar Ch. ◽  
Bikash Sahoo
Keyword(s):  
United States ◽  
Size Distribution ◽  
United States Of America ◽  
Droplet Size Distribution ◽  
The United States ◽  
Drug Substance ◽  
Regulatory Agencies ◽  
Metered Dose ◽  
Radiological Health

Generic Nebulized aerosol is often perceived as inferior to their branded counterparts; however, they are safe and effective if they can meet the regulatory requirements. International regulatory agencies have developed recommendations and guidance for bioequivalence approaches of orally inhaled drug products (OIDPs) for local action. The objective of this article is to discuss the approaches can be used for to show bioequivalence requirement for Food and Drug Administration (FDA) in the United States of America (USA) with reference product. This review endorsed that inhalation solutions and suspensions undertaken to determine the drug substance delivery rate, total drug substance delivered and Aerodynamic assessment of nebulized aerosols [aerodynamic particle size distribution (APSD)/droplet size distribution (DSD)].These are the most important parameters in characterization, evaluation and bioequivalence studies of nebulizers. These devices operate continuously; once loaded and require little or no co-ordination on the part of user they proved that these devices suitable for weak, pediatric or geriatric patients. The regulatory agencies declared that; there is no specific requirements testing in case of nebulizers like Metered dose inhalers (MDI) and Dry powder inhalers (DPIs). In United States of America (USA) regulation falls under the auspices of centre for devices and radiological health (CDRH), and new devices require 510(k) premarket notification. This review outlines all the bioequivalence test parameter.  

Enhancing the Performance of a Model to Predict Driving Distraction with the Random Forest Classifier

2021 ◽  
pp. 036119812110186
Author(s):  
Samira Ahangari ◽  
Mansoureh Jeihani ◽  
Anam Ardeshiri ◽  
Md Mahmudur Rahman ◽  
Abdollah Dehzangi
Keyword(s):  
Random Forest ◽  
Driving Simulator ◽  
Situational Awareness ◽  
True Positive Rate ◽  
The United States ◽  
Driving Performance ◽  
Lane Changing ◽  
Wide Range ◽  
Positive Rate ◽  
Better Than

Distracted driving is known to be one of the main causes of crashes in the United States, accounting for about 40% of all crashes. Drivers’ situational awareness, decision-making, and driving performance are impaired as a result of temporarily diverting their attention from the primary task of driving to other unrelated tasks. Detecting driver distraction would help in adapting the most effective countermeasures. To tackle this problem, we employed a random forest (RF) classifier, one of the best classifiers that has attained promising results for a wide range of problems. Here, we trained RF using the data collected from a driving simulator, in which 92 participants drove under six different distraction scenarios of handheld calling, hands-free calling, texting, voice command, clothing, and eating/drinking on four different road classes (rural collector, freeway, urban arterial, and local road in a school zone). Various driving performance measures such as speed, acceleration, throttle, lane changing, brake, collision, and offset from the lane center were investigated. Using the RF method, we achieved 76.5% prediction accuracy on the independent test set, which is over 8.2% better than results reported in previous studies. We also obtained a 76.6% true positive rate, which is 14% better than those reported in previous studies. Such results demonstrate the preference of RF over other machine learning methods to identify driving distractions.

Estimating the Risk of Extreme Wind Gusts in Tropical Cyclones Using Idealized Large-Eddy Simulations and a Statistical-Dynamical Model

2021 ◽  
Author(s):  
Daniel P. Stern ◽  
George H. Bryan ◽  
Chia-Ying Lee ◽  
James D. Doyle
Keyword(s):  
Tropical Cyclones ◽  
The United States ◽  
Large Eddy Simulations ◽  
Dynamical Model ◽  
Near Surface ◽  
Southeastern Us ◽  
Wind Gusts ◽  
Extreme Wind ◽  
Large Eddy

AbstractRecent studies have shown that extreme wind gusts are ubiquitous within the eyewall of intense tropical cyclones (TCs). These gusts pose a substantial hazard to human life and property, but both the short-term (i.e., during the passage of a single TC) and long-term (over many years) risk of encountering such a gust at a given location is poorly understood. Here, simulated tower data from large-eddy simulations of idealized TCs in a quiescent (i.e., no mean flow or vertical wind shear) environment are used to estimate these risks for the offshore region of the United States. For both a category 5 and category 3 TC, there is a radial region where nearly all simulated towers experience near-surface (the lowest 200 m) 3-s gusts exceeding 70 m s−1 within a 10-minute period; on average, these towers respectively sample peak 3-s gusts of 110 and 80 m s−1. Analysis of an observational dropsonde database supports the idealized simulations, and indicates that offshore structures (such as wind turbines) in the eyewall of a major hurricane are likely to encounter damaging wind speeds. This result is then incorporated into an estimate of the long-term risk, using analyses of the return period for major hurricanes from both a best-track database and a statistical-dynamical model forced by reanalysis. For much of the nearshore region of the Gulf of Mexico and southeastern US coasts, this analysis yields an estimate of a 30-60% probability of any given point experiencing at least one 70 m s−1 gust within a 30-year period.

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