Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Volume measurement”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 541 records · Page 30
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

RhizoVision Explorer: open-source software for root image analysis and measurement standardization

Abstract Roots are central to the function of natural and agricultural ecosystems by driving plant acquisition of soil resources and influencing the carbon cycle. Root characteristics like length, diameter and volume are critical to measure to understand plant and soil functions. RhizoVision Explorer is an open-source software designed to enable researchers interested in roots by providing an easy-to-use interface, fast image processing and reliable measurements. The default broken roots mode is intended for roots sampled from pots and soil cores, washed and typically scanned on a flatbed scanner, and provides measurements like length, diameter and volume. The optional whole root mode for complete root systems or root crowns provides additional measurements such as angles, root depth and convex hull. Both modes support providing measurements grouped by defined diameter ranges, the inclusion of multiple regions of interest and batch analysis. RhizoVision Explorer was successfully validated against ground truth data using a new copper wire image set. In comparison, the current reference software, the commercial WinRhizo™, drastically underestimated volume when wires of different diameters were in the same image. Additionally, measurements were compared with WinRhizo™ and IJ_Rhizo using a simulated root image set, showing general agreement in software measurements, except for root volume. Finally, scanned root image sets acquired in different labs for the crop, herbaceous and tree species were used to compare results from RhizoVision Explorer with WinRhizo™. The two software showed general agreement, except that WinRhizo™ substantially underestimated root volume relative to RhizoVision Explorer. In the current context of rapidly growing interest in root science, RhizoVision Explorer intends to become a reference software, improve the overall accuracy and replicability of root trait measurements and provide a foundation for collaborative improvement and reliable access to all.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2025

Precise magnetic field mapping of the EMPHATIC Phase 1 magnet with COMSOL

A compact Halbach array magnet is used to measure the momentum of the secondary particles in EMPHATIC(Experiment to Measure the Production ofHadrons At a Test beam InChicagoland). Hall probe data was taken for the central cylindrical bore of the magnet and a field map was constructed. COMSOL Multiphysics® Software is used for modeling the magnet and constructing the corresponding magnetic field map. Here, we present a fitting approach where the hall probe data is used to determine a 1mm-spacing map of the entire volume of the magnet using COMSOL. The new map will allow for linear interpolation within the volume, and expand the map to outside the measurement volume, thus increasing the acceptance and precision of EMPHATIC's tracking system.

47 OTHER INSTRUMENTATION↗
NASA NTRS1989

A potential nuclear magnetic resonance imaging approach for noncontact temperature measurement

It is proposed that in a nuclear magnetic resonance (NMR) imaging experiment that it should be possible to measure temperature through an extended volume. The basis for such a measurement would depend upon sensing a temperature dependent on NMR parameter in an inert, volatile molecule (or fluid) filling the volume of interest. Exploratory work suggest that one suitable candidate for such a purpose might be CH3Cl. Possible parameters, other inert gases and feasible measurement schemes that might provide such temperature measurement are discussed.

Manatt, Stanley L.↗
NASA NTRS1984

Free Volume Considerations in Thermoplastic and Thermosetting Resins

The direct measurement of physical aging and of the volume changes which go on during the course of this aging is discussed. Data on PMMA showing its physical aging as measured by its stress relaxation response and the accompanying volume changes are presented. An indication of how one can measure the free volume both directly from the volume change itself and relatively directly via a new technique is given. The application of this new technique (electron spin resonance spectroscopy) to other polymer systems is demonstrated.

Landel, R. F.↗
NASA NTRS2009

First Measurements of the HCFC-142b Trend from Atmospheric Chemistry Experiment (ACE) Solar Occultation Spectra

The first measurement of the HCFC-142b (CH3CClF2) trend near the tropopause has been derived from volume mixing ratio (VMR) measurements at northern and southern hemisphere mid-latitudes for the 2004-2008 time period from spaceborne solar occultation observations recorded at 0.02/cm resolution with the ACE (atmospheric chemistry experiment) Fourier transform spectrometer. The HCFC-142b molecule is currently the third most abundant HCFC (hydrochlorofluorocarbon) in the atmosphere and ACE measurements over this time span show a continuous rise in its volume mixing ratio. Monthly average measurements at northern and southern hemisphere midlatitudes have similar increase rates that are consistent with surface trend measurements for a similar time span. A mean northern hemisphere profile for the time span shows a near constant VMR at 8-20km altitude range, consistent on average for the same time span with in situ results. The nearly constant vertical VMR profile also agrees with model predictions of a long lifetime in the lower atmosphere.

Rinsland, Curtis P.↗
NASA NTRS1977

Observations in energy balance in man during spaceflight

An investigation was undertaken of the changes in metabolic energy balance which occur in weightlessness. Daily energy intake was determined each day throughout the 28-, 59-, and 84-day flights for each of the nine Skylab astronauts. The energy content of the urine and feces was also measured. Changes in body composition were inferred from measurements of weight, volume, water, and total exchangeable potassium before and after flight. During flight, changes were followed by a daily measurement of body mass and by metabolic balance. Examination of the data reveal losses in body weight during the 1st and 2nd months of flight, a loss in body water and protein during the 1st month and a loss of fat during the 1st, 2nd, and 3rd months of flight. The energy input was about 41.7 kcal/kg per day on the ground, and 43.7 kcal/kg per day after 3 months in space. The increase in net energy input of about 1.6% per month is significant (P less than 0.05). When the net energy input is expressed on the basis of total body potassium, the increase in the resulting normalized net energy input of about 3.7% per month is also significant (P less than 0.05).

Rambaut, P. C.↗
NASA NTRS2014

Relationship between LIBS Ablation and Pit Volume for Geologic Samples: Applications for in situ Absolute Geochronology

In planetary sciences, in situ absolute geochronology is a scientific and engineering challenge. Currently, the age of the Martian surface can only be determined by crater density counting. However this method has significant uncertainties and needs to be calibrated with absolute ages. We are developing an instrument to acquire in situ absolute geochronology based on the K‐Ar method. The protocol is based on the laser ablation of a rock by hundreds of laser pulses. Laser Induced Breakdown Spectroscopy (LIBS) gives the potassium content of the ablated material and a mass spectrometer (quadrupole or ion trap) measures the quantity of 40Ar released. In order to accurately measure the quantity of released 40Ar in cases where Ar is an atmospheric constituent (e.g., Mars), the sample is first put into a chamber under high vacuum. The 40Arquantity, the concentration of K and the estimation of the ablated mass are the parameters needed to give the age of the rocks. The main uncertainties with this method are directly linked to the measures of the mass (typically some μg) and of the concentration of K by LIBS (up to 10%). Because the ablated mass is small compared to the mass of the sample, and because material is redeposited onto the sample after ablation, it is not possible to directly measure the ablated mass. Our current protocol measures the ablated volume and estimates the sample density to calculate ablated mass. The precision and accuracy of this method may be improved by using knowledge of the sample's geologic properties to predict its response to laser ablation, i.e., understanding whether natural samples have a predictable relationship between laser energy deposited and resultant ablation volume. In contrast to most previous studies of laser ablation, theoretical equations are not highly applicable. The reasons are numerous, but the most important are: a) geologic rocks are complex, polymineralic materials; b) the conditions of ablation are unusual (for example, variable vacuum pressure), and c) the ablation is made with hundreds of successive laser pulses. In this work, we aim to understand the effects that occur on LIBS spectra when a homogeneous rock or a mineral is ablated under high vacuum. Understanding these effects is important to define best practices for LIBS measurements and may lead to improved measurement (or possibly prediction) of the ablated volume. We will describe our laboratory approach and first results, and discuss its utility for situ absolute geochronology campaigns.

Devismes, D.↗
NASA NTRS2002

Pulmonary venous flow determinants of left atrial pressure under different loading conditions in a chronic animal model with mitral regurgitation

BACKGROUND: The aim of our study was to quantitatively compare the changes and correlations between pulmonary venous flow variables and mean left atrial pressure (mLAP) under different loading conditions in animals with chronic mitral regurgitation (MR) and without MR. METHODS: A total of 85 hemodynamic conditions were studied in 22 sheep, 12 without MR as control (NO-MR group) and 10 with MR (MR group). We obtained pulmonary venous flow systolic velocity (Sv) and diastolic velocity (Dv), Sv and Dv time integrals, their ratios (Sv/Dv and Sv/Dv time integral), mLAP, left ventricular end-diastolic pressure, and MR stroke volume. We also measured left atrial a, x, v, and y pressures and calculated the difference between v and y pressures. RESULTS: Average MR stroke volume was 10.6 +/- 4.3 mL/beat. There were good correlations between Sv (r = -0.64 and r = -0.59, P <.01), Sv/Dv (r = -0.62 and r = -0.74, P <.01), and mLAP in the MR and NO-MR groups, respectively. Correlations were also observed between Dv time integral (r = 0.61 and r = 0.57, P <.01) and left ventricular end-diastolic pressure in the MR and NO-MR groups. In velocity variables, Sv (r = -0.79, P <.001) was the best predictor of mLAP in both groups. The sensitivity and specificity of Sv = 0 in predicting mLAP 15 mm Hg or greater were 86% and 85%, respectively. CONCLUSION: Pulmonary venous flow variables correlated well with mLAP under altered loading conditions in the MR and NO-MR groups. They may be applied clinically as substitutes for invasively acquired indexes of mLAP to assess left atrial and left ventricular functional status.

Pulmonary Veins/physiopathology↗
DOE OSTI2025

Analysis of soot formation from aviation fuels in laminar counterflow flames

Combustion emissions from aviation contribute to the formation of condensation trail (contrail) that can lead to the formation of anthropogenic cirrus clouds. Ice particles that form contrails are observed to have a linear correlation with soot particle number density. Synthetic aviation fuels (SAFs) offer a promising route to mitigate the production of soot particles while also increasing energy security. Although studies have focused on combustion and spray behavior, the detailed investigation of soot formation processes for different jet fuels and their impact on models for computational fluid dynamics (CFD) applications is not well understood. Moreover, experimental measurements of soot for canonical flames using Synthetic aviation fuels (SAF) for model validation remain scarce. To address this, we use employed the Lawrence Livermore National Laboratory (LLNL) detailed soot model based on the discrete sectional method. Additionally, we develop two reduced chemical mechanisms for Jet-A and Alcohol-to-Jet (C1) that are suitable for turbulent flame simulations and couple them with the Hybrid Method of Moments (HMOM). The detailed and reduced model frameworks are validated against experimental measurements of soot volume fraction (ƒ ν ) from a counterflow burner experiment previously reported in the literature. Given the good agreement between modeling results and experimental measurements for the (1) spatial distribution of ƒ ν and (2) the non-linear variation of peak ƒ ν with strain rate, we further investigate the modeled sub-processes (nucleation, condensation, surface growth, and oxidation) using the LLNL model to analyze the assumptions in the reduced model framework. Furthermore, the results indicate a significant contribution from resonant radicals to the surface growth of soot particles, which are not accounted for in the current implementation of HMOM and could help reconcile soot predictions by the reduced model with observations.

Counterflow↗
NASA NTRS1991

Electric fields in the solar atmosphere - A review

A review is presented of remote sensing techniques which measure the electric field component transverse to the line of sight and achieve a sensitivity range of 5-10 V/cm. Three models are shown to predict quasistatic, macroscopic values of E(parallel), the electric field component parallel to the magnetic vector, beyond the sensitivity range considered. These processes are: the discharge model of flares; the models of return currents related to flare particle beams; and the models of neutral sheets related to two-ribbon flares and postflare loops. Time dependent electric fields related to MHD and plasma waves, and to plasma disturbance, may allow the detection of both E components (parallel and perpendicular). The uncertainty relating to the emission measures, time scales, volumes, and plasma conditions of these flares and electrified plasma volumes is emphasized. It is pointed out, however, that important information can be obtained by observing electric fields at existing sensitivity levels. By measuring these E-fields, the understanding of flares and related dynamic events can be improved.

Foukal, P.↗
NASA NTRS1995

Capacitive Sensing Of Gaseous Fraction In Two-Phase Flow

Instrument makes nonintrusive, real-time capacitive measurements to determine volume fraction of vapor or other gas in flowing, electrically nonconductive liquid/gas mixture. Works even with liquids having relatively low permittivities. Useful for measuring proportions of vapor in boiling, condensing, and flowing heat-transfer fluids and in cryogenic fluids.

Crowley, Christopher J.↗
DOE OSTI2025

Confocal Raman Microscopy as an In Situ Probe of Volume Change in Hydration-Sensitive Polymer Membranes

An approach is described for measuring hydration-induced volume change within ion conductive polymer membranes and thin films by adapting the technique of confocal Raman microscopy. With careful consideration of factors that affect excitation and scattering within the confocal probe volume region, material swelling and deswelling were estimated from the intensities of polymer matrix spectral features. A high numerical aperture oil-immersion objective was used to achieve tight focusing within samples and the efficient collection of Raman scattered light. The approach is demonstrated for a fluorinated cation-exchange ionomer (Nafion) and the hydrocarbon anion-exchange ionomer Sustainion. Samples were monitored while under a nitrogen atmosphere that was cycled between dry and humid (∼50% relative humidity, RH) states. The volume changes estimated from the Raman spectra were in close agreement with those derived from conventional measurements. The reported work advances understanding needed to adapt confocal Raman microscopy for quantitative in situ and operando studies of ionomers within electrochemical devices, such as polymer electrolyte membrane fuel cells and electrolyzers, and lays a foundation for broader applications in the study of hydration-induced polymer swelling and the associated molecular level water and polymer framework structural changes.

Absorption↗
DOE OSTI2024

Integrated top-down process and voxel-based microstructure modeling for Ti-6Al-4V in laser wire direct energy deposition process

Laser-wire metal additive manufacturing (AM) is one of the ideal direct energy deposition (DED) processes for creating large-scale parts with a medium level of complexity. However, the DED process involves complex thermal signatures and wide length scales making the fabrication of realistic AM components and part qualification often reliant on experimental trial-and-error optimization. While experimental measurements over the full volume of a part are valuable and necessary, measuring the entire area of a part is significantly laborious and practically infeasible, particularly for large parts in terms of cost and rapid qualification. Therefore, in this work, we developed an effective thermal and microstructure modeling framework based on the Johnson–Mehl-Avrami-Kolmogorov (JMAK) and Koistinen & Marburger (KM) models through a top-down approach that considers plate distortion-affected thermal profiles. A voxel-by-voxel simulation method is used to predict individual phase fractions of Ti-6Al-4 V. The predicted results were validated through detailed metallurgical measurements. A combined voxel-by-voxel approach with a sparse data reconstruction technique produced a near-perfect reconstruction of the original data. This approach anticipates a significant reduction in data points and computation time and resources. Lastly, we conclude with potential extensions of this work to other modeling efforts.

36 MATERIALS SCIENCE↗
NASA NTRS1994

Lung volumes during sustained microgravity on Spacelab SLS-1

Gravity is known to influence the topographical gradients of pulmonary ventilation, perfusion, and pleural pressures. The effect of sustained microgravity on lung volumes has not previously been investigated. Pulmonary function tests were performed by four subjects before, during, and after 9 days of microgravity exposure. Ground measurements were made in standing and supine postures. Tests were performed using a bag-in-box and flowmeter system and a respiratory mass spectrometer. Measurements of tidal volume (V(sub T)), expiratory reserve volume (ERV), inspiratory and expiratory vital capacities (IVC, EVC), functional residual capacity (FRC), and residual volume (RV) were made. During microgravity, V(sub T) decreased by 15%. IVC and EVC were slightly reduced during the first 24 hrs of microgravity and returned to 1 g standing values within 72 hrs after the onset of microgravity. FRC was reduced by 15% and ERV decreased by 10-20%. RV was significantly reduced by 18%. The reductions in FRC, ERV, and V(sub T) during microgravity are probably due to the cranial shift of the diaphragm and an increase in intrathoracic blood volume.

Elliott, Ann R.↗
NASA NTRS1994

Leg muscle volume during 30-day 6-degree head-down bed rest with isotonic and isokinetic exercise training

Magnetic resonance imaging (MRI) was used to compare the effect of two modes of lower-extremity exercise training on the mass (volume) of posterior leg group (PLG) muscles (soleus, flexor hallucis longus, tibialis posterior, lateral and medial gastrocnemius, and flexor digitorum longus) on 19 men (ages 32-42 years) subjected to intense dynamic-isotonic (ITE, cycle ergometer, number of subjects (N) = 7), isokinetic (IKE, torque egrometer, N = 7), and no exercise (NOE, N = 5) training for 60 min/day during head-down bed rest (HDBR). Total volume of the PLG muscles decreased (p less than 0.05) similarly: ITE = 4.3 +/- SE 1.6%, IKE = 7.7 +/- 1.6%, and NOE = 6.3 +/- 0.8%; combined volume (N = 19) loss was 6.1 +/- 0.9%. Ranges of volume changes were 2.6% to -9.0% (ITE), -2.1% to -14.9% (IKE), and -3.4% to -8/1% (NOE). Correlation coefficients (r) of muscle volume versus thickness measured with ultrasonography were: ITE r + 0.79 (p less than 0.05), IKE r = 0.27 (not significant (NS)), and NOE r = 0.63 (NS). Leg-muscle volume and thickness were highly correlated (r = 0.79) when plasma volume was maintained during HDBR with ITE. Thus, neither intensive lower extremity ITE nor IKE training influence the normal non-exercised posterior leg muscle atrophy during HDBR. The relationship of muscle volume and thickness may depend on the mode of exercise training associated with the maintenance of plasma volume.

Greenleaf, J. E.↗
NASA NTRS2012

Rugged, Portable, Real-Time Optical Gaseous Analyzer for Hydrogen Fluoride

Hydrogen fluoride (HF) is a primary evolved combustion product of fluorinated and perfluorinated hydrocarbons. HF is produced during combustion by the presence of impurities and hydrogen- containing polymers including polyimides. This effect is especially dangerous in closed occupied volumes like spacecraft and submarines. In these systems, combinations of perfluorinated hydrocarbons and polyimides are used for insulating wiring. HF is both highly toxic and short-lived in closed environments due to its reactivity. The high reactivity also makes HF sampling problematic. An infrared optical sensor can detect promptly evolving HF with minimal sampling requirements, while providing both high sensitivity and high specificity. A rugged optical path length enhancement architecture enables both high HF sensitivity and rapid environmental sampling with minimal gaseous contact with the low-reactivity sensor surfaces. The inert optical sample cell, combined with infrared semiconductor lasers, is joined with an analog and digital electronic control architecture that allows for ruggedness and compactness. The combination provides both portability and battery operation on a simple camcorder battery for up to eight hours. Optical detection of gaseous HF is confounded by the need for rapid sampling with minimal contact between the sensor and the environmental sample. A sensor is required that must simultaneously provide the required sub-parts-permillion detection limits, but with the high specificity and selectivity expected of optical absorption techniques. It should also be rugged and compact for compatibility with operation onboard spacecraft and submarines. A new optical cell has been developed for which environmental sampling is accomplished by simply traversing the few mm-thick cell walls into an open volume where the measurement is made. A small, low-power fan or vacuum pump may be used to push or pull the gaseous sample into the sample volume for a response time of a few seconds. The optical cell simultaneously provides for an enhanced optical interaction path length between the environmental sample and the infrared laser. Further, the optical cell itself is comprised of inert materials that render it immune to attack by HF. In some cases, the sensor may be configured so that the optoelectronic devices themselves are protected and isolated from HF by the optical cell. The optical sample cell is combined with custom-developed analog and digital control electronics that provide rugged, compact operation on a platform that can run on a camcorder battery. The sensor is inert with respect to acidic gases like HF, while providing the required sensitivity, selectivity, and response time. Certain types of combustion events evolve copious amounts of HF, very little of other gases typically associated with combustion (e.g., carbon monoxide), and very low levels of aerosols and particulates (which confound traditional smoke detectors). The new sensor platform could warn occupants early enough to take the necessary countermeasures.

Pilgrim, Jeffrey↗
NASA NTRS2007

An Experimental Investigation of the Laminar Flamelet Concept for Soot Properties

The soot properties of round, nonbuoyant, laminar jet diffusion flames are described, based on experiments at microgravity carried out on orbit during three flights of the Space Shuttle Columbia, (Flights STS-83, 94 and 107). Experimental conditions included ethylene- and propane-fueled flames burning in still air at an ambient temperature of 300 K and ambient pressures of 35-100 kPa. Measurements included soot volume fraction distributions using deconvoluted laser extinction imaging, and soot temperature distributions using deconvoluted multiline emission imaging. Flowfield modeling based on the work of Spalding is presented. The present work explores whether soot properties of these flames are universal functions of mixture fraction, i.e., whether they satisfy soot state relationships. Measurements are presented, including radiative emissions and distributions of soot temperature and soot volume fraction. It is shown that most of the volume of these flames is bounded by the dividing streamline and thus should follow residence time state relationships. Most streamlines from the fuel supply to the surroundings are found to exhibit nearly the same maximum soot volume fraction and temperature. The radiation intensity along internal streamlines also is found to have relatively uniform values. Finally, soot state relationships were observed, i.e., soot volume fraction was found to correlate with estimated mixture fraction for each fuel/pressure selection. These results support the existence of soot property state relationships for steady nonbuoyant laminar diffusion flames, and thus in a large class of practical turbulent diffusion flames through the application of the laminar flamelet concept.

Diez, F. J.↗
NASA NTRS2024

Application of Long-Path Gas Cell Assisted Infrared Spectroscopy for Detection of Lunar Volatiles and Advanced Curation Efforts

The motivation behind analyzing gaseous samples from the Permanently Shadowed Regions (PSRs) on the lunar surface is built upon the volatiles observed during the LCROSS mission. Advanced curation techniques under cold conditions are essential to the critical scientific analysis of these returned samples. The detection of various volatiles in returned samples by gas-phase infrared (IR) spectroscopy is known to be a powerful tool to understand the resources present in planetary bodies and Astro-materials. The identification and quantification of volatile compounds in returned planetary samples and regolith simulants by advanced and custom-built analytical devices are areas of primary research interest in our group and the Planetary Exploration & Astromaterials Research Laboratory (PEARL) facility. In this context, we discuss recent advancements and experimental results for quick analysis of the major volatiles detected by the LCROSS (water, CO 2 , CH 3 OH, and NH 3 ) by a long-path gas cell/FTIR (Fourier Transform Infrared) spectrometer system. The applicability of this system is demonstrated by qualitative analysis of a series of volatiles measured individually. In addition, the linear dependence of absorption intensity on headspace sample volumes was checked by measuring gas-phase IR absorption spectra of increasing volumes of pure CO 2 gas aliquots. Finally, the instrument performance was evaluated by measuring the relative concentration of NH 3 (g) in methanol solution.

Curation↗