Journal articles: 'Bulk field measurement'

1

Tomita, Masaru, Yusuke Fukumoto, Kenji Suzuki, and Yukikazu Iwasa. "Measurement of the magnetic field of resin-impregnated bulk superconductor annuli." Physica C: Superconductivity and its Applications 470 (December 2010): S33—S34. http://dx.doi.org/10.1016/j.physc.2010.01.020.

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Shibata, M., R. Kinjo, Y. W. Choi, M. Omer, H. Negm, T. Konstantin, K. Yoshida, et al. "Development of a field measurement system for the Bulk HTSC SAU." Journal of Physics: Conference Series 425, no. 3 (March 22, 2013): 032021. http://dx.doi.org/10.1088/1742-6596/425/3/032021.

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Baxter, E. F. "Field measurement of high temperature bulk reaction rates I: Theory and technique." American Journal of Science 302, no. 5 (May 1, 2002): 442–64. http://dx.doi.org/10.2475/ajs.302.5.442.

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GRMELA, L., R. MACKU, and P. TOMANEK. "Near-field measurement of ZnS:Mn nanocrystal and bulk thin-film electroluminescent devices." Journal of Microscopy 229, no. 2 (February 2008): 275–80. http://dx.doi.org/10.1111/j.1365-2818.2008.01900.x.

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Czarnetzki, U., D. Luggenhölscher, V. A. Kadetov, and H. F. Döbele. "Plasma diagnostics by laser spectroscopic electric field measurement." Pure and Applied Chemistry 77, no. 2 (January 1, 2005): 345–58. http://dx.doi.org/10.1351/pac200577020345.

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Laser spectroscopic electric field measurements have the potential to become a versatile tool for the diagnostics of low-temperature plasmas. From the spatially and temporally resolved field distribution in the sheath close to electrodes or surfaces in general, a broad range of important plasma parameters can be inferred directly: electron temperature; ion density distribution; displacement-, ion-, electron-diffusion current density; and the sheath potential. Indirectly, the electron and ion energy distribution functions and information on the ion dynamics in the sheath can also be obtained. Finally, measurements in the quasi-neutral bulk can also reveal even the plasma density distribution with high spatial and temporal resolution. The basic concepts for analysis of the field data are introduced and demonstrated by examples in hydrogen discharges.

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KACHANOSKI, R. G., I. J. VAN WESENBEECK, and E. De JONG. "FIELD SCALE PATTERNS OF SOIL WATER STORAGE FROM NON-CONTACTING MEASUREMENTS OF BULK ELECTRICAL CONDUCTIVITY." Canadian Journal of Soil Science 70, no. 3 (August 1, 1990): 537–42. http://dx.doi.org/10.4141/cjss90-056.

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Soil water storage (0–1.7 m) was measured every 10 m in a 660-m-long transect using a neutron probe and compared to bulk electrical conductivity, ECA, measurements obtained using noncontacting electomagnetic induction meters. Coherency analysis indicated a lack of correlation at scales less than 40 m. At scales greater than 40 m, ECA explained more than 80% of the variation of soil water storage. Measurement of ECA should be a simple and fast method of determining general field patterns of soil water storage. Key words: Spatial variability, soil water, coherency, electromagnetic induction

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Tokuyama, M., Y. Yanagi, and H. Ikuta. "Local measurement of the pulsed field magnetization process of melt-processed bulk superconductor." Physica C: Superconductivity and its Applications 463-465 (October 2007): 405–9. http://dx.doi.org/10.1016/j.physc.2007.03.444.

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8

Ting Liu, 刘婷, 陈险峰 Xianfeng Chen, 狄子昀 Ziyun Di, 张军锋 Junfeng Zhang, 李新碗 Xinwan Li, and 陈建平 Jianping Chen. "Measurement of the magnetic field-dependent refractive index of magnetic fluids in bulk." Chinese Optics Letters 6, no. 3 (2008): 195–97. http://dx.doi.org/10.3788/col20080603.0195.

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9

Pop, V. "The Influence of Heat Treatment on Electric Properties of Bulk (Bi,Pb):2223 Superconductor." International Journal of Modern Physics B 17, no. 21 (August 20, 2003): 3807–11. http://dx.doi.org/10.1142/s0217979203021824.

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The (Bi,Pb)(Sr,Ba) :2223 samples were prepared using different sintering temperatures. The electrical properties were investigated by electrical resistance and V–I characteristics measurements. The increase of sintering temperature induces the decrease of transition width and the increase of intergranular critical current density Jcj and phase purity. The critical current density from electrical measurement agrees with the results obtained from complex magnetic susceptibility measurements function of temperature and AC field amplitude.

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Nicolaou, Georgios, Robert Wicks, George Livadiotis, Daniel Verscharen, Christopher Owen, and Dhiren Kataria. "Determining the Bulk Parameters of Plasma Electrons from Pitch-Angle Distribution Measurements." Entropy 22, no. 1 (January 16, 2020): 103. http://dx.doi.org/10.3390/e22010103.

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Electrostatic analysers measure the flux of plasma particles in velocity space and determine their velocity distribution function. There are occasions when science objectives require high time-resolution measurements, and the instrument operates in short measurement cycles, sampling only a portion of the velocity distribution function. One such high-resolution measurement strategy consists of sampling the two-dimensional pitch-angle distributions of the plasma particles, which describes the velocities of the particles with respect to the local magnetic field direction. Here, we investigate the accuracy of plasma bulk parameters from such high-resolution measurements. We simulate electron observations from the Solar Wind Analyser’s (SWA) Electron Analyser System (EAS) on board Solar Orbiter. We show that fitting analysis of the synthetic datasets determines the plasma temperature and kappa index of the distribution within 10% of their actual values, even at large heliocentric distances where the expected solar wind flux is very low. Interestingly, we show that although measurement points with zero counts are not statistically significant, they provide information about the particle distribution function which becomes important when the particle flux is low. We also examine the convergence of the fitting algorithm for expected plasma conditions and discuss the sources of statistical and systematic uncertainties.

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Zeng, Li Yun, and Yu Hong Mao. "Synchronous Flow Field Measurement during Coagulation Processes by PIV." Advanced Materials Research 864-867 (December 2013): 2069–72. http://dx.doi.org/10.4028/www.scientific.net/amr.864-867.2069.

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Particle image velocimetry (PIV) was applied to measurement and characterization the velocity field during the coagulation process under the conditions that used kaolin flocs as the seed particles without any other special seed particle. The results indicated that there were similar special wave structure of the vortexes generated on meridianal plane, the forms and the size of the adjacent vortexes changed periodically, and the bulk fluid motion was observed between vortices when the rotating speed was between 20~60 rpm, this could be very helpful in flocs combination with each other and growing into larger flocs, which could bring about the higher flocculation efficiency. At the same time, it was demonstrated that the kaolin flocs can be used as seed particle to characterization and measurement the flow field structure with good performance in the coagulation process by PIV. It was also considered that PIV can be exploited as a useful tool in the synchronous measurement the velocity field during flocculation processes.

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12

Boyle, J. P. "Field Results from a Second-Generation Ocean/Lake Surface Contact Heat Flux, Solar Irradiance, and Temperature Measurement Instrument—The Multisensor Float." Journal of Atmospheric and Oceanic Technology 24, no. 5 (May 1, 2007): 856–76. http://dx.doi.org/10.1175/jtech1898.1.

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Abstract This paper describes results from two field programs that support development of a wave-following surface contact multisensor float (MSF) designed to simultaneously measure net surface heat flux, net solar irradiance, and water temperature. The results reported herein compare measurements from a second-generation design (circa 1998) against directly measured radiative fluxes as well as turbulent fluxes derived using both eddy correlation and bulk aerodynamic methods. The reference flux data are collected using instrumented towers, buoys, and research vessels. Comparisons show that MSF net surface fluxes and net solar irradiance are in generally good agreement with values that are measured or derived using standard instruments and methods, having root-mean-square differences less than approximately 15%. MSF near-surface bulk water temperature measurement shows good agreement with similar measurements from a drifting buoy. MSF measurement of water surface temperature is not definitively determined, although results suggest it may be a good measure of skin temperature at night. MSF flux measurement occurs from within the aqueous conductive sublayer and so does not use turbulence models or parameterizations. At this time, results are most reliable in low wind conditions (2 m s−1 ≤ U10 ≤ 7 m s−1) and relatively calm seas. In higher winds and more active seas, the imperfect surface drifting and wave-following characteristics of the second-generation system limit its performance. More fundamentally, perturbation to the aqueous conductive sublayer and modification of near-surface turbulence structure by the MSF may also limit flux measurement accuracy under certain conditions.

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13

Gordillo, Leonardo, and Nicolás Mujica. "Measurement of the velocity field in parametrically excited solitary waves." Journal of Fluid Mechanics 754 (August 14, 2014): 590–604. http://dx.doi.org/10.1017/jfm.2014.416.

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AbstractParametrically excited solitary waves emerge as localized structures in high-aspect-ratio free surfaces subject to vertical vibrations. Herein, we provide the first experimental characterization of the hydrodynamics of these waves using particle image velocimetry. We show that the underlying velocity field of parametrically excited solitary waves is primarily composed of a subharmonic oscillatory component. Our results confirm the accuracy of Hamiltonian models with added dissipation in describing this field. Remarkably, our measurements also uncover the onset of a streaming velocity field which we show to be as important as other crucial nonlinear terms in the current theory. Using vorticity equations, we show that the streaming pattern arises from the coupling of the potential bulk flow with the oscillating boundary layers on the vertical walls. Numerical simulations provide good agreement between this model and experiments.

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Pepin, Steeve, André P. Plamondon, and Jean Stein. "Peat water content measurement using time domain reflectometry." Canadian Journal of Forest Research 22, no. 4 (April 1, 1992): 534–40. http://dx.doi.org/10.1139/x92-070.

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The calibration of time domain reflectometry, previously established for an organic soil of 0.422 Mg•m−3 bulk density, was established for peat blocks with bulk densities ranging from 0.06 to 0.25 Mg•m−3. An empirical relationship between the volumetric water content and the measured apparent dielectric constant was established in the laboratory. This relationship can be used to estimate volumetric water content between 0.21 and 0.95 cm3•cm−3 with a standard deviation of 0.03 cm3•cm−3. The large variations observed during the calibration were mainly attributed to the size and heterogeneousness of peat samples. When water tables in the field were high, standard deviation decreased to 0.02 cm3•cm−3, which agrees very well with other time domain reflectometry experiments.

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15

Ding, Kai, Yang Bai, Xi Han, Wen Jie Zhang, and Li Jie Qiao. "Estimate of Thermodynamic Indirect Measurement on the Electrocaloric Effect." Key Engineering Materials 492 (September 2011): 164–67. http://dx.doi.org/10.4028/www.scientific.net/kem.492.164.

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The thermodynamics indirect measurement based on Maxwell relation is one of the most popular methods for the studies on electrocaloric effect of ferroelectric material, including bulk ceramics, single crystals and thin films.However,recent reports indicated that the results obtained through this method did not agree with those from the direct measurements in many cases, such as nearTcor under high electric field. This paper discussed the applicability of thermodynamics indirect measurement and analyzed the reason why its calculated result may be different from the true value of electrocaloric effect. Because the thermodynamics indirect characterization depends on the measurement of polarization at different temperatures, the testing frequency ofP-Eloops, leakage current of sample and temperature resolution of measurement play the important roles in the accuracy measurement of electrocaloric effect.

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Raghukumar, Kaustubha, Grace Chang, Frank Spada, Craig Jones, Tim Janssen, and Andrew Gans. "Performance Characteristics of “Spotter,” a Newly Developed Real-Time Wave Measurement Buoy." Journal of Atmospheric and Oceanic Technology 36, no. 6 (June 2019): 1127–41. http://dx.doi.org/10.1175/jtech-d-18-0151.1.

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AbstractThe Spotter is a low-cost, real-time, solar-powered wave measurement buoy that was recently developed by Spoondrift Technologies, Inc. (Spoondrift). To evaluate the data quality of the Spotter device, we performed a series of validation experiments that included comparisons between Spotter-derived motions and prescribed wave motions (monochromatic and random waves) on a custom-built, motion-controlled validation stand and simultaneous in-water measurements using a conventional wave measurement buoy, the Datawell DWR-G4 (Datawell). Spotter evaluations included time-domain validation (i.e., wave by wave) and comparisons of wave spectra, directional moments, and bulk statistical parameters such as significant wave height, peak period, mean wave direction, and directional spread. Spotter wave measurements show excellent fidelity and lend a high degree of confidence in data quality. Overall, Spotter-derived bulk statistical parameters were within 10% of respective Datawell-derived quantities. The Spotter’s low cost and compact form factor enabled unique field deployments of multiple wave measurement buoys for direct measurements of wave characteristics such as ocean wave decorrelation length scales, wave speed, and directional spread. Wave decorrelation lengths were found to be inversely proportional to the width of the spectrum, and wave speeds compared well against linear wave theory.

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17

Abd El Fattah, Ahmed, Ibrahim Al-Duais, Kyle Riding, Michael Thomas, Salah Al-Dulaijan, and Mesfer Al-Zahrani. "Field Validation of Concrete Transport Property Measurement Methods." Materials 13, no. 5 (March 5, 2020): 1166. http://dx.doi.org/10.3390/ma13051166.

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Reinforcing steel corrosion, caused by chloride ingress into concrete, is the leading cause of reinforced concrete deterioration. One of the main findings in the literature for reducing chloride ingress is the improvement of the durability characteristics of concrete by the addition of supplementary cementitious materials (SCMs) and/or chemical agents to concrete mixtures. In this study, standard ASTM tests—such as rapid chloride permeability (RCPT), bulk diffusion and sorptivity tests—were used to measure concrete properties such as porosity, sorptivity, salt diffusion, and permeability. Eight different mixtures, prepared with different SCMs and corrosion inhibitors, were tested. Apparent and effective chloride diffusion coefficients were calculated using bound chloride isotherms and time-dependent decrease in diffusion. Diffusion coefficients decreased with time, especially with the addition of SCMs and corrosion inhibitors. The apparent diffusion coefficient calculated using the error function was slightly lower than the effective diffusion coefficient; however, there was a linear trend between the two. The formation factor was found to correlate with the effective diffusion coefficient. The results of the laboratory tests were compared and benchmarked to their counterparts in the marine exposure site in the Arabian Gulf in order to identify laboratory key tests to predict concrete durability. The overall performance of concrete containing SCMs, especially fly ash, were the best among the other mixtures in the laboratory and the field.

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18

Otabe, Edmund S., Mohammed N. Hasan, and Teruo Matsushita. "A standard method of measurement of the irreversibility field for bulk RE-123 superconductors." Superconductor Science and Technology 18, no. 12 (November 4, 2005): S219—S222. http://dx.doi.org/10.1088/0953-2048/18/12/001.

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19

Takayanagi, Isao, Kazuya Matsumoto, and Jun‐ichi Nakamura. "Measurement of electron impact ionization coefficient in bulk silicon under a low‐electric field." Journal of Applied Physics 72, no. 5 (September 1992): 1989–92. http://dx.doi.org/10.1063/1.351625.

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Boehringer, Matthias, and Ralf Augke. "Field Passivation of the Silicon Wafer Rear Surface for Reliable Bulk Recombination Lifetime Measurement." Journal of The Electrochemical Society 155, no. 7 (2008): H474. http://dx.doi.org/10.1149/1.2907404.

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21

Lousberg, Gregory P., Jean-François Fagnard, Jacques G. Noudem, Marcel Ausloos, Benoit Vanderheyden, and Philippe Vanderbemden. "Measurement of the magnetic field inside the holes of a drilled bulk high-Tcsuperconductor." Superconductor Science and Technology 22, no. 4 (March 4, 2009): 045009. http://dx.doi.org/10.1088/0953-2048/22/4/045009.

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22

Wang, Hu, Wensheng Wu, Tianzhi Tang, Ruigang Wang, Aizhong Yue, Shusheng Wang, Chao Yang, and Xinyue Fu. "A new method for calculating bulk density in pulsed neutron-gamma density logging." GEOPHYSICS 85, no. 6 (November 1, 2020): D219—D232. http://dx.doi.org/10.1190/geo2018-0821.1.

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Formation density is one of the most important parameters in formation evaluation. Radioisotope chemical sources are used widely in conventional gamma-gamma density (GGD) logging. Considering security and environmental risks, there has been growing interest in pulsed neutron generators in place of the radioactive-chemical source in using bulk-density measurements. However, there still is the requirement of high accuracy of the neutron-gamma density (NGD) calculation. Pair production is one of the factors influencing the accuracy of the results, which should be considered. We have adopted a method, based on the difference between the inelastic gamma-ray response of high- and low-energy windows, to reduce the impact of pair production upon calculating the bulk density. A new density estimation algorithm is derived based on the coupled-field theory and gamma-ray attenuation law in NGD logging. We analyze the NGD measurement accuracy with different mineral types, porosity, and pore fluid and determine the influence of the borehole environment on NGD logging. The Monte Carlo simulation results indicate that the improved processing algorithm limits the influence of the mineral type, porosity, or pore fluid. The NGD measurement accuracy is ±0.025 g/cm3 in shale-free formations, which is close to the GGD measurement (±0.015 g/cm3). Our results also show that the borehole environment has a significant impact on NGD measurement. Therefore, it is necessary to take the influence of the borehole parameters into account in NGD measurements. Combined with Monte Carlo simulation cases, we evaluate the application results of the new density estimation algorithm in various model wells.

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Abel, S. J., R. J. Cotton, P. A. Barrett, and A. K. Vance. "A comparison of ice water content measurement techniques on the FAAM BAe-146 aircraft." Atmospheric Measurement Techniques 7, no. 9 (September 17, 2014): 3007–22. http://dx.doi.org/10.5194/amt-7-3007-2014.

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Abstract. This paper presents a comparison of ice water content (qi) data from a variety of measurement techniques on the Facility for Airborne Atmospheric Measurements (FAAM) BAe-146 research aircraft. Data are presented from a range of cloud types measured during the PIKNMIX field experiment that include mixed-phase stratocumulus, cumulus congestus and cirrus clouds. These measurements cover a broad range of conditions in which atmospheric ice particles are found in nature, such as the low-ice-water-content environments typically found in midlatitude cirrus and the environments with much higher ice water content often observed in cold convective clouds. The techniques include bulk measurements from (i) a Nevzorov hot-wire probe, (ii) the difference between the measured total water content (condensed plus vapour) and the water vapour content of the atmosphere and (iii) a counterflow virtual impactor (CVI) (only for cirrus measurements). We also estimate the qi from integration of the measured particle size distribution (PSD) with assumptions on how the density of ice particles varies as a function of size. The results show that the only bulk ice water content technique capable of measuring high qi values (several g m−3) was the method of total water content minus water vapour. For low ice water contents we develop a new parametrisation of the Nevzorov baseline drift that enables the probe to be sensitive to qi ± 0.002 g m−3. In cirrus clouds the agreement between the Nevzorov and other bulk measurements was typically better than a factor of 2 for the CVI (qi > 0.008 g m−3) and the method of total water content minus water vapour (qi > 0.02 g m−3). Good agreement with the bulk measurements for all cases could be obtained with the estimate from the PSD provided that appropriate a priori assumptions on the mass–dimension relationship were made. This is problematic in the convective clouds sampled because pristine ice particles, heavily rimed particles and supercooled liquid drops were all present. In a cirrus case, we show that using a temperature-dependent mass–dimension relation was required to match the bulk measurement of qi.

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Abel, S. J., R. J. Cotton, P. A. Barrett, and A. K. Vance. "A comparison of ice water content measurement techniques on the FAAM BAe-146 aircraft." Atmospheric Measurement Techniques Discussions 7, no. 5 (May 14, 2014): 4815–57. http://dx.doi.org/10.5194/amtd-7-4815-2014.

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Abstract. This paper presents a comparison of ice water content (qi) data from a variety of measurement techniques on the Facility for Airborne Atmospheric Measurements (FAAM) BAe-146 research aircraft. Data are presented from a range of cloud types measured during the PIKNMIX field experiment that include mixed phase stratocumulus, cumulus congestus and cirrus clouds. These measurements cover a broad range of conditions in which atmospheric ice particles are found in nature, such as the low ice water content environments typically found in mid-latitude cirrus and the much higher ice water content environments often observed in cold convective clouds. The techniques include bulk measurements from (i) a Nevzorov hot-wire probe (ii) the difference between the measured total water content (condensed plus vapour) and the water vapour content of the atmosphere and (iii) a Counterflow Virtual Impactor (CVI) (only for cirrus measurements). We also estimate the qi from integration of the measured particle size distribution (PSD) with assumptions on how the density of ice particles varies as a function of size. The results show that the only bulk ice water content technique capable of measuring high qi values (several g kg−1) was the total water content minus water vapour method. For low ice water contents we develop a new parametrization of the Nevzorov base-line drift that enables the probe to be sensitive to qi ± 0.002 g m−3. In cirrus clouds the agreement between the Nevzorov and other bulk measurements was typically better than a factor of two for the CVI (qi 0.01 g kg−1) and the total water content minus water vapour method (qi > 0.03 g kg−1). Good agreement with the bulk measurements for all cases could be obtained with the estimate from the PSD provided that appropriate a-priori assumptions on the mass–dimension relationship were made. This is problematic in the convective clouds sampled because pristine ice particles, heavily rimed particles and supercooled liquid drops were all present. In a cirrus case we show that using a temperature dependent mass–dimension relation was required to match the bulk measurement of qi.

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25

KISHNÉ, A. SZ, C. L. S. MORGAN, H. C. CHANG, and L. B. KISH. "VIBRATION-INDUCED CONDUCTIVITY FLUCTUATION MEASUREMENT FOR SOIL BULK DENSITY ANALYSIS." Fluctuation and Noise Letters 07, no. 04 (December 2007): L473—L481. http://dx.doi.org/10.1142/s0219477507004112.

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Soil bulk density is a physical property of soils that affects water storage, water and nutrient movement, and plant root activity in the soil profile. The ability to quantify soil bulk density using vibration-induced conductivity fluctuation was investigated with possible field applications in the future. The AC electrical conductance of soil was measured using a pair of blade-like electrodes while exposing to periodic vibration. The blades were positioned longitudinally and transversally to the direction of the induced vibration to enable the calculation of a normalized index. This normalized index was expected to provide data independent from the vibration strength, and to reduce the effect of soil salinity and water content. Simulations on a simplified resistor lattice indicate that the ratio of transversal and longitudinal fluctuation decreases as soil bulk density increases. The experiment was conducted on natural and salinized fine sand at two moisture conditions and four compaction levels. The blade-shaped electrodes improved electrode-soil contact compared to cylindrical electrodes, and thereby, reduced measurement noise. Dry sand measurements showed an inverse correlation between the normalized conductivity fluctuation and soil bulk density for both longitudinal and transversal fluctuation. The wet natural and salinized soils performed very similarly as hypothesized, but their normalized VICOF response was not associated with bulk density changes. This lack of sensitivity might be attributed to the heavy electrodes and/or the specific vibration method used. The effects of electrode material, vibration method and soil properties on the experiment need further study.

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Waddington, D. C., and R. J. Orlowski. "Determination of Acoustical Impedance of Absorbing Surfaces by Two-Microphone Transfer Function Techniques: Effect of Absorption Mechanism." Building Acoustics 4, no. 2 (June 1997): 99–115. http://dx.doi.org/10.1177/1351010x9700400203.

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In the third of a series of papers on the measurement of acoustical impedance of absorbing surfaces using the two-microphone transfer function technique, the influence of surface absorption mechanism upon the measured impedance is described. The results from measurements of the impedance of bulk reactors are compared with values obtained from theoretical models. Materials investigated are an inhomogeneous polyurethane foam, a distributed resonance absorber, and a twin layer foam. This paper also investigates how the measurement technique behaves with samples which are bulk reacting and have surface roughness. A rough surfaced polyurethane foam sample is used. The results indicate that at frequencies for which the surface irregularities are small in comparison to the wavelength, the material can be accurately characterised by the acoustical impedance acting at an effective plane. For higher frequencies it is thought that the measuring technique becomes inaccurate due to scattering of sound by the surface roughness, and the consequent breakdown of the sound field prediction methods.

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Zettl, Julie D., Mingbin Huang, S. Lee Barbour, and Bing C. Si. "Density-dependent calibration of multisensor capacitance probes in coarse soil." Canadian Journal of Soil Science 95, no. 4 (November 2015): 331–36. http://dx.doi.org/10.4141/cjss-2015-021.

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Zettl, J. D., Huang, M., Barbour, S. L. and Si, B. C. 2015. Density-dependent calibration of multisensor capacitance probes in coarse soil. Can. J. Soil Sci. 95: 331–336. Coarse-textured reconstructed soils are utilized extensively in the reclamation of mining waste. Accurate and continuous sensing of soil water content is required to understand soil water dynamics and evaluate the hydraulic characteristics of these soils. The EnviroSCAN (Sentek Pty. Ltd, Australia) is a semi-permanent multisensor capacitance probe (MCP) capable of continuous measurement of volumetric water content (θv) and has been used to monitor reclamation soil cover performance. Calibration of these probes is required to improve the accuracy of field measurements. In this study, field and laboratory measurements were undertaken over a range of water contents and bulk densities to refine the relationship between θvand scaled frequency (SF) measured by the MCP. The manufacturer's calibration equation tended to underestimate θvunder wet conditions (θv>0.35 cm3cm–3). Our experimental data showed that bulk density (ρb) did affect the MCP calibration and consequently a new calibration equation that includes the effect of ρbis developed using laboratory measurements and validated using field measurements. This equation provided the highest degree of correlation and the smallest standard deviation of prediction to measured values of θvfor laboratory and field measurements, respectively. This calibration improves the application of the EnviroSCAN for coarse-textured soils such as those utilized in this study.

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Granados, X., S. Iliescu, B. Bozzo, E. Bartolome, Teresa Puig, X. Obradors, J. Amorós, and M. Carrera. "Magnetic Mapping - A Way to Test and Understand Current Flows in Thin and Bulk Superconductors." Advances in Science and Technology 47 (October 2006): 1–6. http://dx.doi.org/10.4028/www.scientific.net/ast.47.1.

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Nondestructive testing of superconducting blocks and thin films is a worth point in their development and their industrial production. The most intrinsic characteristic to be tested is the critical current, so is the maximum current can be carried in the superconducting state. The measurement of the current flowing through the samples could be done by direct transport experiments but this means using specific samples, and only the mean current may be found. Distribution of current density in the sample is more relevant because it yields the map of inhomogeneity of the samples, and its effect in the current density distribution. Magnetic measurements have been developed by Hall scanning and magneto-optical effect, allowing the mapping of the component of the magnetic field perpendicular to a surface of the sample created by the current distribution. By solving the inverse Biot-Savart problem a map of current densities can be obtained. We will present the status of the magnetic measurements obtained by exploring superconducting bulks and tapes magnetized by an external field and the magnetic map generated by the current carried through superconducting wires.

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Tang, M. X., J. W. Huang, J. C. E, Y. Y. Zhang, and S. N. Luo. "Full strain tensor measurements with X-ray diffraction and strain field mapping: a simulation study." Journal of Synchrotron Radiation 27, no. 3 (April 15, 2020): 646–52. http://dx.doi.org/10.1107/s1600577520003926.

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Strain tensor measurements are important for understanding elastic and plastic deformation, but full bulk strain tensor measurement techniques are still lacking, in particular for dynamic loading. Here, such a methodology is reported, combining imaging-based strain field mapping and simultaneous X-ray diffraction for four typical loading modes: one-dimensional strain/stress compression/tension. Strain field mapping resolves two in-plane principal strains, and X-ray diffraction analysis yields volumetric strain, and thus the out-of-plane principal strain. This methodology is validated against direct molecular dynamics simulations on nanocrystalline tantalum. This methodology can be implemented with simultaneous X-ray diffraction and digital image correlation in synchrotron radiation or free-electron laser experiments.

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Baxter, E. F. "Field measurement of high temperature bulk reaction rates II: Interpretation of results from a field site near Simplon Pass, Switzerland." American Journal of Science 302, no. 6 (June 1, 2002): 465–516. http://dx.doi.org/10.2475/ajs.302.6.465.

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31

Nolan, T. P., R. Sinclair, T. Yamashita, and R. Ranjan. "Correlation of microstructural and magnetic properties of longitudinal recording media using TEM." Proceedings, annual meeting, Electron Microscopy Society of America 51 (August 1, 1993): 1016–17. http://dx.doi.org/10.1017/s0424820100150915.

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Cobalt alloy on chromium thin film media are used in industry because of their large values of coercivity (Hc), remanent magnetization (Mr), squareness (S*), and relatively low noise. The magnetic properties depend strongly on processing conditions and, as will be shown, the resulting microstructure.A complete structure-processing-properties analysis requires effective measurement of both magnetic and microstructural properties. Direct micromagnetic-microstructural comparison is not yet readily available, but bulk hysteresis loop parameters are reproducible and highly correlated with both desired recording characteristics and microstructures, and so provide a valuable, albeit indirect comparison. Signal to noise (S/N) measurements are also used as a more direct measure of usefulness in a high density disk drive. The nanoscale microstructural features which dramatically affect these bulk magnetic properties are difficult to observe. However, careful combination of TEM techniques, including bright-field, dark-field, high-resolution, selected area diffraction and elongated-probe microdiffraction can determine the subtle microstructural differences.

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Tioh, Jin-Wei, Sasha Oster, Mani Mina, and Robert J. Weber. "Optimization of Magnetooptic Device by Low Switching Field Domains." ISRN Optics 2012 (February 6, 2012): 1–5. http://dx.doi.org/10.5402/2012/865794.

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This paper expounds on the optimization of magnetooptic devices using preferential domains that switch at low field strengths. In particular, an all-optical switch for transparent networks based on the Mach-Zehnder interferometer configuration is examined in detail. The switch utilizes bismuth-substituted iron garnets with a specific composition of (Bi1.1Tb1.9)(Fe4.25Ga0.75)O12 as Faraday rotators. It is proposed that switch figures of merit can be improved by preferentially choosing domains which align with applied fields at field strengths much lower than required by the bulk material. Measurement of magnetic domain orientation in the material and Faraday rotation within domains is reported. The domain behavior in low magnetic fields is also investigated to achieve a switch with lower switching times and higher extinction ratios.

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Ohrt, Christoph, Wito Hartmann, Johannes Weickmann, Markus Kästner, Albert Weckenmann, Tino Hausotte, and Eduard Reithmeier. "Holistic Measurement in the Sheet-Bulk Metal Forming Process with Fringe Projection." Key Engineering Materials 504-506 (February 2012): 1005–10. http://dx.doi.org/10.4028/www.scientific.net/kem.504-506.1005.

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Sheet bulk metal forming is a new forming technology, currently developed by several companies and research institutes. It creates high demands on the inspection of parts and tools, especially in the field of in-situ abrasion detection of the forming tool and its impacts on the work piece. This manuscript introduces two optical testing methods for fulfilling these inspection tasks: On the one hand the endoscopic fringe projection as a flexible small scale optical measurement principal with high depth of focus and accuracy for the acquisition of filigree form elements for a continuous abrasion determination and one the other hand the multi-scaled fringe projection for a holistic one shot measurement of the work piece for an adapted, multiscale deviation analysis. The development and advantages of both systems for the sheet bulk metal forming process are shown as well as potentials of the combination of the both systems close to the proposed application next to the production line.

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Hong, Z., P. Vanderbemden, R. Pei, Y. Jiang, A. M. Campbell, and T. A. Coombs. "The Numerical Modeling and Measurement of Demagnetization Effect in Bulk YBCO Superconductors Subjected to Transverse Field." IEEE Transactions on Applied Superconductivity 18, no. 2 (June 2008): 1561–64. http://dx.doi.org/10.1109/tasc.2008.920594.

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Ichimura, Masaya, Atsushi Tada, Eisuke Arai, Hiroyuki Takamatsu, and Shingo Sumie. "Bulk carrier lifetime measurement by the microwave reflectance photoconductivity decay method with external surface electric field." Applied Physics Letters 80, no. 23 (June 10, 2002): 4390–92. http://dx.doi.org/10.1063/1.1483114.

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Klimov, E., M. Fuelleborn, and H. W. Siesler. "Electric-Field-Induced Reorientation of Liquid Crystalline p-Cyanophenyl-p-n-Alkylbenzoates: A Time-Resolved Study by Fourier Transform Infrared Transmission and Attenuated Total Reflection Spectroscopy." Applied Spectroscopy 57, no. 5 (May 2003): 499–505. http://dx.doi.org/10.1366/000370203321666498.

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Time-resolved polarization Fourier transform infrared (FT-IR) transmission and attenuated total reflection (ATR) spectroscopy were applied to investigate the reorientation phenomena of the three members of the homologous series of nematic liquid crystalline p-cyanophenyl-p-n-alkylbenzoates 6CPB, 7CPB, and 10CPB under the external perturbation of an electric field. In conjunction with a newly constructed measurement cell, this method allowed us to differentiate the response of the LC system in the surface layer and in the bulk of the cell at different temperatures and voltages. The relaxation time of the LC molecules close to the wall of the cell was found to be shorter than in the bulk. However, at a field strength of 7 V, the initial orientation in the bulk preceeds the analogous process in the surface region.

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Huang, Q., O. O. Akinremi, R. Sri Rajan, and P. Bullock. "Laboratory and field evaluation of five soil water sensors." Canadian Journal of Soil Science 84, no. 4 (November 1, 2004): 431–38. http://dx.doi.org/10.4141/s03-097.

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Accurate in situ determination of soil water content is important in many fields of agricultural, environmental, hydrological, and engineering sciences. As numerous soil water content sensors are available on the market today, the knowledge of their performance will aid users in the selection of appropriate sensors. The objectives of this study were to evaluate five soil water sensors in the laboratory and to determine if laboratory calibration is appropriate for the field. In this study, the performances of five sensors, including the Profile Probe™ (PP), ThetaProbe™ , Watermark™, Aqua-Tel™, and Aquaterr™ were compared in the laboratory. The PP and ThetaProbe™ were more accurate than the other soil water sensors, reproducing soil water content using factory recommended parameters. However, when PP was installed on a loamy sand in the field, the same soil that was used for the laboratory evaluation, it overestimated field soil water, especially at depth. Another laboratory experiment showed that soil water content readings from the PP were strongly influenced by soil bulk density. The higher the soil bulk density, the greater was the overestimation of soil water content. Two regression parameters, a0 and a1, which are used to convert the apparent dielectric constant to volumetric water content, were found to increase linearly with the soil bulk density in the range of 1.2 to 1.6 Mg m-3. Finally, the PP was calibrated in the field and a good calibration function was obtained with an r2 of 0.87 and RMSE of 2.7%. The values of a0 and a1 obtained in the field were different from factory recommended parameters (a0 = 2.4 versus 1.6 while a1 = 12.5 versus 8.4) and were independent of soil depth, bulk density, and texture. As such, individual field calibration will be necessary to obtain precise and accurate measurement of soil water content with this instrument. Key words: Soil water content, Profile Probe, calibration, soil water content sensor

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XIAOWEN, CAO, HAN GUCHANG, and ZHANG TINGYU. "A NEW LOWER CRITICAL FIELD AND ANOMALY OF MAGNETIZATION CURVE IN HIGH TcY1Ba2Cu3O7−δ BULK SUPERCONDUCTORS." Modern Physics Letters B 01, no. 09n10 (January 1988): 383–88. http://dx.doi.org/10.1142/s0217984988001430.

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The magnetization behaviors of single phase Y1Ba2Cu3O7−δ bulk superconductors have been studied by measurement of the DC susceptibility. It is found that there are two lower critical field. One which is near 10 Oe at 77K is defined as a weak lower critical field and denoted by HclJ. dHc1J/dT is about 0.2 Oe/K near Tc. Another is still called as usual lower critical field, Hcl. It is 60 Oe at 77K and dHc1/dT is about 4.6 Oe/K. The detailed measurement of DC magnetization shows also that an anomaly of the magnetization curve appears between HclJ and Hc1. The amplitudes of anomalous peak and valley have some difference depending on how samples are prepared. The mechanism of Hc1J appearance and the anomaly of the magnetization has been discussed in “Soft Sponge Model” which will be published in Chin. J. Low Temperature Physics.

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Safriani, Lusi, Risdiana, Fitrilawati, Ayi Bahtiar, Annisa Aprilia, Rustam E. Siregar, Maykel Manawan, Dita Puspitasari Sari, Julia Angel, and Isao Watanabe. "μSR Study with Light Irradiation of P3HT:ZnO Nanoparticles as Active Material of Hybrid Solar Cells." Materials Science Forum 966 (August 2019): 404–8. http://dx.doi.org/10.4028/www.scientific.net/msf.966.404.

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Recently, hybrid solar cell that consists of a combination of organic and inorganic materials offers promise in increasing efficiency. Combination of conjugated polymer of Poly (3-hexyl thiophene)/P3HT which has the highest hole mobility with inorganic materials which has high electron mobility, good physical and chemical stability of inorganic nanocrystals, shows a better performance of hybrid solar cells. We have conducted a measurement to investigate the charge carrier transport in active material of hybrid solar cells by using muon spin relaxation (μSR) with light irradiation. A bulk sample used in this study is hybrid organic-inorganic material consisting of regio-regular P3HT and ZnO nanoparticles. Longitudinal-field μSR measurements were performed in magnetic field ranging from 0 to 395 mT at temperature of 10 K, 15 K and 25 K. Based on μSR measurement with light irradiation, we found that for those temperatures, longitudinal field dependence of λ1 was proportional with C-H0.5 curve indicating three-dimensional inter-chain diffusion. We assume that light irradiation initiates the production of exciton that increases the number of charge carrier in the sample and transports not only along the chain of polymer (one-dimensional) but also perpendicular to other chain of polymer (three-dimensional). With light irradiation, the crossover temperature from one-dimensional to three-dimensional of regio-regular P3HT and ZnO nanoparticles bulk sample was obtained at lower temperature of 10 K compared to previous result at 25 K without light irradiation.

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Labelle, Eric R., and Dirk Jaeger. "Influence of Saturated Organic Matter on the Accuracy of In-Situ Measurements Recorded with a Nuclear Moisture and Density Gauge." Croatian journal of forest engineering 42, no. 2 (January 14, 2021): 357–67. http://dx.doi.org/10.5552/crojfe.2021.762.

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The impact of machines on forest soils is regularly assessed and quantified using absolute bulk density, which is most frequently obtained by soil cores. However, to allow for repeated measurements at the exact same locations, non-destructive devices are increasingly being used to determine soil bulk density and moisture content in field studies. An example of such a device is a nuclear moisture and density gauge (NMDG), originally designed as a control measurement for soil bulk density and moisture content in geotechnical applications. Unlike road construction or foundation projects that use mineral soil or gravel, forest soils have complex structures and the presence of organic matter, which can skew moisture and density readings from a NMDG. To gain further knowledge in this respect, we performed controlled tests in a sandbox to quantify the influence of varying amounts of saturated organic matter (3, 5, 10, and 15%) mixed with mineral soil in different layers (0–5, 0–10, 0–20 and 0–40 cm) on the accuracy of soil moisture content obtained by a NMDG and soil theta probe at varying depths. Main results illustrated that the presence of saturated organic matter per se was not problematic but moisture content overestimations and related underestimation of dry bulk density occurred when the tested measurement depth was below the created organic layer. Since forest soils often exhibit higher organic matter contents in the upper horizon, correction factors are suggested to minimize the moisture content variations between NMDG and reference method. With the use of correction factors, NMDG can present a non-destructive, fast, and accurate method of measuring soil moisture and bulk density in forestry applications.

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Gavalda-Diaz, Oriol, Jack Lyons, Siyang Wang, Max Emmanuel, Katharina Marquardt, Eduardo Saiz, and Finn Giuliani. "Basal Plane Delamination Energy Measurement in a Ti3SiC2 MAX Phase." JOM 73, no. 6 (April 26, 2021): 1582–88. http://dx.doi.org/10.1007/s11837-021-04635-9.

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AbstractThe {0001} basal plane delamination dominating the crack-wake bridging in MAX phases at a bulk scale has been investigated by studying the small-scale fracture of a Ti3SiC2. In situ micro-double cantilever beam (DCB) tests in a scanning electron microscope were used to grow a stable crack along the basal plane, measure the fracture energy, and study the crack propagation mechanism at the nanoscale. The results show that the fracture energy (10–50 J/m2) depends on small misorientations angles (e.g., 5°) of the basal plane to the stress field. This induces permanent deformation which can be observed once the DCB has been unloaded. The nanoscale study of the crack shows that the plasticity at the crack tip is small, but a number of pairs of dislocations are forming at each side of the crack. Hence, this study helps to explain the enhanced fracture energy values and possible sources of energy dissipation in basal plane delamination, which is the one of the main toughening mechanisms in the bulk fracture of MAX phases.

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Keane, Robert E., Elizabeth D. Reinhardt, Joe Scott, Kathy Gray, and James Reardon. "Estimating forest canopy bulk density using six indirect methods." Canadian Journal of Forest Research 35, no. 3 (March 1, 2005): 724–39. http://dx.doi.org/10.1139/x04-213.

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Canopy bulk density (CBD) is an important crown characteristic needed to predict crown fire spread, yet it is difficult to measure in the field. Presented here is a comprehensive research effort to evaluate six indirect sampling techniques for estimating CBD. As reference data, detailed crown fuel biomass measurements were taken on each tree within fixed-area plots located in five important conifers types in the western United States, using destructive sampling following a series of four sampling stages to measure the vertical and horizontal distribution of canopy biomass. The six ground-based indirect measurement techniques used these instruments: LI-COR LAI-2000, AccuPAR ceptometer, CID digital plant canopy imager, hemispherical photography, spherical densiometer, and point sampling. These techniques were compared with four aggregations of crown biomass to compute CBD: foliage only, foliage and small branchwood, foliage and all branchwood (no stems), and all canopy biomass components. Most techniques had the best performance when all canopy biomass components except stems were used. Performance dropped only slightly when the foliage and small branchwood canopy biomass aggregation (best approximates fuels available for crown fires) was employed. The LAI-2000, hemispherical photography, and CID plant canopy imager performed best. Regression equations that predict CBD from gap fraction are presented for all six techniques.

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Jessup, A. T., and R. Branch. "Integrated Ocean Skin and Bulk Temperature Measurements Using the Calibrated Infrared In Situ Measurement System (CIRIMS) and Through-Hull Ports." Journal of Atmospheric and Oceanic Technology 25, no. 4 (April 1, 2008): 579–97. http://dx.doi.org/10.1175/2007jtecho479.1.

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Abstract The design and performance of a shipboard-integrated system for underway skin and bulk temperature is presented. The system consists of the Calibrated Infrared In situ Measurement System (CIRIMS) and through-hull temperature sensors. The CIRIMS is an autonomous shipboard radiometer system that measures the sea surface skin temperature Tskin for validation of satellite-derived sea surface temperature products. General design considerations for shipboard radiometer systems are discussed and the philosophy behind the CIRIMS design is presented. Unique features of the design include a constant temperature housing to stabilize instrument drift, a two-point dynamic calibration procedure, separate sky- and sea-viewing radiometers for simultaneous measurements, and the ability to use an infrared transparent window for environmental protection. Laboratory testing and field deployments are used to establish an estimated error budget, which includes instrumentation and environmental uncertainties. The combination of this testing and field comparison to the Marine-Atmosphere Emitted Radiance Interferometer (M-AERI) and Infrared SST Autonomous Radiometer (ISAR) instruments indicates that the CIRIMS meets the design goal of ±0.10°C accuracy. Temperature and pressure sensors were installed in custom-designed through-hull ports on the NOAA research vessel (R/V) Ronald H. Brown and the University of Washington R/V Thomas G. Thompson to complement the CIRIMS measurements. The ports allow sensors to be installed while the ship is in water and can accommodate a variety of sensors. The combined system provides the ability to measure near-surface temperature profiles from the skin to a depth of 5 m while underway.

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Ünal, İlker, Önder Kabaş, and Salih Sözer. "Real-Time Electrical Resistivity Measurement and Mapping Platform of the Soils with an Autonomous Robot for Precision Farming Applications." Sensors 20, no. 1 (January 1, 2020): 251. http://dx.doi.org/10.3390/s20010251.

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Soil electrical resistivity (ER) is an important indicator to indirectly determine soil physical and chemical properties such as moisture, salinity, porosity, organic matter level, bulk density, and soil texture. In this study, real-time ER measurement system has been developed with the help of an autonomous robot. The aim of this study is to provide rapid measurement of the ER in large areas using the Wenner four-probe measurement method for precision farming applications. The ER measurement platform consists of the Wenner probes, a y-axis shifter driven by a DC motor through a gear reducer, all installed on a steel-frame that mount to an autonomous robot. An embedded industrial computer and differential global positioning system (DGPS) were used to assist in real-time measuring, recording, mapping, and displaying the ER and the robot position during the field operation. The data acquisition software was codded in Microsoft Visual Basic.NET. Field experiments were carried out in a 1.2 ha farmland soil. ER and DGPS values were stored in Microsoft SQL Server 2005 database, an ordinary Kriging interpolation technique by ArcGIS was used and the average ER values were mapped for the soil depth between 0 and 50 cm. As a result, ER values were observed to be between 30.757 and 70.732 ohm-m. In conclusion, the experimental results showed that the designed system works quite well in the field and the ER measurement platform is a practical tool for providing real-time soil ER measurements.

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Koinkar, Pankaj, Makoto Kanazawa, Yu Ohsumi, Akihiro Furube, and Mahendra A. More. "Formation of WS2 nanosheets and its field emission studies." International Journal of Modern Physics B 32, no. 19 (July 18, 2018): 1840078. http://dx.doi.org/10.1142/s0217979218400787.

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The present study describes the results on the formation of WS2 nanosheets using the nanosecond laser ablation in a liquid environment. The laser ablation in liquid is a well-known method and is widely used for the generation of nanostructure. The nanosecond laser ablation is used to irradiate WS2 in a isopropyl alcohol to generate WS2 nanosheets. The laser ablation time was 120 min. The field emission measurement of irradiated WS2 nanostructures was performed. The Bulk and WS2 were used to characterize the Transmission Electron Microscopy (TEM) and Raman spectroscopy to reveal their surface and structural morphology. It is found that the laser ablation time is an important parameter to transform the bulk WS2 into WS2 nanosheets. The generation of WS2 nanosheets is revealed by the Raman spectra. Moreover, the TEM images indicate that the size of WS2 microsheet has been reduced to 400 nm after the laser ablation treatment. It is also found that the field emission current density of WS2 is increased after the laser ablation. The improvement in the field emission characteristics of WS2 is due to the formation of WS2 as well as the separation of layered WS2 structure into few layers of WS2. The formation of WS2 nanosheets can be used for future optoelectronic devices.

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Plancher, E., V. Favier, C. Maurice, E. Bosso, N. Rupin, J. Stodolna, D. Loisnard, et al. "Direct measurement of local constitutive relations, at the micrometre scale, in bulk metallic alloys." Journal of Applied Crystallography 50, no. 3 (June 1, 2017): 940–48. http://dx.doi.org/10.1107/s1600576717006185.

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Multiscale models involving crystal plasticity are essential to predict the elastoplastic behavior of structural materials with respect to their microstructure. However, those models are often limited by a poor knowledge of the local constitutive behavior. This article reports a method to measure the mechanical behavior directly, at the micrometre scale, in bulk crystalline materials. Local strain and stress states were evaluated at the surface of a bent stainless steel crystal by combining total strain measurements – performed with the digital image correlation technique on optical images – with elastic strain measurements obtained by Laue microdiffraction. A local constitutive relation was measured, in an efficient nondestructive way, without the need for full-field simulations. The method was validated by a comparison between the measured local behavior and the macroscopic behavior of the single crystal.

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Bentley, J., N. D. Evans, and E. A. Kenik. "Measurement of Scanning Electron Microscope resolution." Proceedings, annual meeting, Electron Microscopy Society of America 52 (1994): 1044–45. http://dx.doi.org/10.1017/s0424820100172954.

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The resolution performance of a scanning electron microscope (SEM) is a primary specification of the instrument. For a high-resolution SEM (HRSEM) equipped with a field emission gun (FEG), image resolutions of less than 2 nm are commonly claimed. Generally, both manufacturers and customers identify image resolution as the single most important performance criterion. It is traditionally determined with specimens such as gold islands on bulk carbon supports, where the minimum apparent separation of two islands is claimed as the resolution. This procedure is highly subjective since the spacings are not known independently. Dodson and Joy have pointed out the paradox implicit in this approach-that “the resolution of a given instrument can be verified only after a better instrument is available to characterize the structure spacing.” By analogy to the now standard approach for high-resolution transmission electron microscopes (TEMs), Dodson and Joy investigated the use of Fourier Transforms (FT) of high-resolution SEM images for measuring resolution.

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Zheng, Zhang, Liang Li, Yin Fei Yang, Ning He, and Wei Zhao. "Prediction and Measurement of Machining Distortion in Aluminium Alloy 7085." Advanced Materials Research 996 (August 2014): 640–45. http://dx.doi.org/10.4028/www.scientific.net/amr.996.640.

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It is essential to accurately predict or model the residual stresses in a material resulting from various manufacturing operations. Numerical methods were used in this study to predict the residual stresses after quenching and cold compression of an Al 7085 forged block. Experimental verification was provided by comparing the measured distortions due to a relaxation of the residual stresses with the predictions obtained by using a simulated stress field. The validation was carried out on a simplified structural part. The measured and simulated distortions were found to be in good agreement with each other. The results indicated that part distortion is attributable to the relaxation of bulk residual stresses.

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Zhang, Zheng, Yinfei Yang, Liang Li, and Jinxing Kong. "Experimental and computational modeling of bulk residual stress for aeronautical components with distinct geometries." Advances in Mechanical Engineering 13, no. 2 (February 2021): 168781402199440. http://dx.doi.org/10.1177/1687814021994402.

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To predict and minimize machining distortion in the manufacturing process, bulk residual stresses in aeronautical components with distinct geometries were investigated via experimental mechanics and numerical simulation. The residual stress state was appropriately simplified according to geometric/processing feathers and deformation patterns of the investigated parts. In each case study, an optimal experimental method was selected to reconstruct the concerned stress tensor. Thereafter, qualitative comparison and validation were performed using cross-method verification and/or numerical simulation. Additionally, the spatial resolution and distribution characteristics of the residual stress were analyzed and discussed in detail. The results revealed that thermal and mechanical nonuniformity caused by material processing is the main source of bulk residual stress in the investigated components. Furthermore, the effectiveness of the contour method on the measurement of different geometric components was verified by numerical simulation. Combining the accurate measurement of the characteristic plane and the appropriate numerical simulation of the global stress field, an engineering-oriented approach for full-field stress evaluation was proposed. This research can provide valuable engineering guidance and suggestions for stress evaluation and distortion analysis prior to manufacturing of integral structures.

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Cho, Yongjin, Kenneth A. Sudduth, and Scott T. Drummond. "Profile Soil Property Estimation Using a VIS-NIR-EC-Force Probe." Transactions of the ASABE 60, no. 3 (2017): 683–92. http://dx.doi.org/10.13031/trans.12049.

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Abstract. Combining data collected in-field from multiple soil sensors has the potential to improve the efficiency and accuracy of soil property estimates. Optical diffuse reflectance spectroscopy (DRS) has been used to estimate many important soil properties, such as soil carbon, water content, and texture. Other common soil sensors include penetrometers that measure soil strength and apparent electrical conductivity (ECa) sensors. Previous field research has related these sensor measurements to soil properties such as bulk density, water content, and texture. A commercial instrument that can simultaneously collect reflectance spectra, ECa, and soil strength data is now available. The objective of this research was to relate laboratory-measured soil properties, including bulk density (BD), total organic carbon (TOC), water content (WC), and texture fractions to sensor data from this instrument. At four field sites in mid-Missouri, profile sensor measurements were obtained to 0.9 m depth, followed by collection of soil cores at each site for laboratory measurements. Using only DRS data, BD, TOC, and WC were not well-estimated (R2 = 0.32, 0.67, and 0.40, respectively). Adding ECa and soil strength data provided only a slight improvement in WC estimation (R2 = 0.47) and little to no improvement in BD and TOC estimation. When data were analyzed separately by major land resource area (MLRA), fusion of data from all sensors improved soil texture fraction estimates. The largest improvement compared to reflectance alone was for MLRA 115B, where estimation errors for the various soil properties were reduced by approximately 14% to 26%. This study showed promise for in-field sensor measurement of some soil properties. Additional field data collection and model development are needed for those soil properties for which a combination of data from multiple sensors is required. Keywords: NIR spectroscopy, Precision agriculture, Reflectance spectra, Soil properties, Soil sensing.

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Journal articles on the topic 'Bulk field measurement'

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