Direct Density Measurements Research Articles

Investigation of the transferability of calibration between alternative fluids for liquid and dense phase carbon dioxide flow measurement

Carbon Capture Utilisation and Storage (CCUS) technology is pivotal for achieving global emissions reduction goals. The rise in CCUS facilities, with a near doubling of global capture capacity, indicates industry momentum. Robust flow measurement across the CCUS transport and storage networks are essential for commercial contracts, financial incentives, and regulatory compliance since these are underpinned by accurate quantification of the CO2 quantity transferred across the CCUS chain. However, a critical gap exists in verification and quality assurance of flow meters as currently there are no traceable calibration facilities that operates with liquid and/or dense phase CO2. However, globally there are many accredited traceable water and oil calibration facilities in operation, which can meet the required flow rates and meter sizes. An experimental study was then conducted at TÜV SÜD National Engineering Laboratory, UK, and at the Institute for Energy Technologies, NO, to explore the transferability of calibration between water, oil, and CO2 using five flow meter technologies with the aim of providing a preliminary assessment of whether meters calibrated in alternative fluids can accurately measure liquid and supercritical CO2. The results suggest that this approach could work for Coriolis meters. The results also suggest caution in relying solely on using Equations of State to calculate density values and a recommendation is presented to currently employing direct density measurements until a more comprehensive understanding is achieved on Equations of State performance for CO2-rich mixtures. To the best of the author's knowledge this is the first time that such experimental investigation is conducted, and the results shared publicly.

Effect of <i>Meloidogyne incognita</i> infection on the accumulation of phenolic compounds in plants of the genus Mint (Mentha L.)

The purpose of the research is to compare the accumulation of phenolic compounds of different species and varieties of mint, zoned in Central Russia against the background of plant infection by Meloidogyne incognita.Materials and methods. Plants were grown from cuttings in a growing experiment in open ground. Mentha × piperita L. (varieties: Tik-Tak, Orange, Minneola, Mojito, Mitchum, Chocolate), M. spicata L. (varieties Morocco, Crispa) and M. longifolia L. (Longifolia) were taken for the study. A month later, the rooted plants were infected at the rate of 1000 sp. infective larvae of M. incognita per plant. After 8 weeks leaves were fixed in ethanol. The total content of phenolic compounds (PC), phenylpropanoids, flavonoids and catechins was studied using a spectrophotometer. The determination of the total content of PС was carried out using the Folin-Cecolte reagent with measurement at 725 nm, phenylpropanoids – by direct measurement of optical density at 330 nm, flavonoids – by reaction with aluminum chloride at 415 nm, the total content of flavans (catechins - flavan-3-ols), their oligomeric forms – proanthocyanidins, as well as leukoanthocyanidins were assessed by reaction with vanillin at 500 nm.Results and discussion. It has been shown that the accumulation of phenols is related to the species of plants. The varieties Mentha × piperita L. in most cases contained more phenols than M. spicata L. and M. longifolia L. A significant number of PC was noted in the violet-colored varieties Mitchum, Chocolate and Orange. The total content of PC almost completely correlates with the content of their precursors – phenylpropanoids. In terms of the content of flavonoids, the Mitchum variety stands out noticeably, and in terms of the content of catechins, the Orange variety stands out. Nematode infection in most varieties causes a noticeable increase in the total accumulation of soluble PC, phenylpropanoids and flavans, but leads to a decrease in the content of flavonoids.

Electrical Responses of Modified Mineral Surfaces as Observed With Spectral Induced Polarization and Atomic Force Microscopy

AbstractAtomic force microscopy (AFM) and spectral induced polarization (SIP) are widely used to investigate the electrical properties of mineral surfaces at vastly different scales of measurement. We compare AFM and SIP measurements made on two different materials (glass beads and silica gel) subjected to etching, deposition of iron oxide particles, and inclusion of calcite grains. We found that the treatments produced qualitatively consistent behaviors in the AFM and SIP data. Direct AFM measurements of surface charge density for silica and calcite surfaces were quantitatively compared to values estimated from the SIP results using a grain polarization model. No statistically significant difference (at a 95% confidence level) was found between the surface charge density of silica estimated by AFM (2.3 ± 6.6 mC/m2 for glass beads and 1.6 ± 0.1 mC/m2 for silica gel) versus SIP (5.4 ± 4.4 mC/m2 for glass beads and 1.6 ± 0.5 mC/m2 for silica gel). The surface charge density for calcite determined by AFM (43.5 ± 12.9 mC/m2) was approximately 19 times higher than that found for silica. While the charge density of calcite surfaces determined by SIP was also generally higher than that found for silica, different treatments produced significantly different values between 4.7 and 258 mC/m2 (with a maximum 95% CI of ±8.7 mC/m2). Several possible explanations exist for the range of the observed SIP measurements, including aging of the calcite surfaces. Overall, this study suggests the potential for the complementary use of AFM and SIP measurements to constrain future investigations of polarization mechanisms in porous media.

Slide electrification of drops at low velocities.

Slide electrification of drops is mostly investigated on tilted plate setups. Hence, the drop charging at low sliding velocity remains unclear. We overcome the limitations by developing an electro drop friction force instrument (eDoFFI). Using eDoFFI, we investigate slide electrification at the onset of drop sliding and at low sliding velocities ≤ 1 cm s-1. The novelty of eDoFFI is the simultaneous measurements of the drop discharging current and the friction force acting on the drop. The eDoFFI tool facilitates control on drop length and width using differently shaped rings. Hereby, slide electrification experiments with the defined drop length-to-width ratios >1 and <1 are realized. We find that width of the drop is the main geometrical parameter which determines drop discharging current and charge separation. We combine Kawasaki-Furmidge friction force equation with our finding on drop discharging current. This combination facilitates the direct measurement of surface charge density (σ) deposited behind the drop. We calculate σ ≈ 45 μC m-2 on Trichloro(1H,1H,2H,2H-perfluorooctyl)silane (PFOTS) and ≈20 μC m-2 on Trichloro(octyl)silane (OTS) coated glass surfaces. We find that the charge separation by moving drops is independent of sliding velocity ≤ 1 cm s-1. The reverse sliding of drop along the same scanline facilitates calculation of the surface neutralization time constant. The eDoFFI links two scientific communities: one which focuses on the friction forces and one which focuses on the slide electrification of drops.

Inverse identification of in-situ curing shrinkage using a method combining 3D digital image correlation and finite-element simulation

Curing shrinkage of adhesives in the bonding process usually leads to deformation and residual stresses. The measurement of curing shrinkage is valuable in providing fundamental information for better understanding, controlling, and optimizing the curing process. This paper developed an efficient hybrid inverse identification method for in-situ measurement of the volume shrinkage. This method associates the artificial fish swarm algorithm (AFSA) with a finite element method (FEM) and 3D digital image correlation (3D-DIC) technology. A homemade apparatus for experimental characterization of curing shrinkage is prepared and tested. The evolution of the volume shrinkage is inversely identified by matching the 3D-DIC and the FEM results using the AFSA algorithm. The results are further validated by a direct-density measurement and the standard physical property of the adhesive. Those experimental results demonstrated that the proposed method is a viable non-contact, non-destructive, and in-situ technique that can be applied to measure the in-situ curing shrinkage.

Linking lidar multiple scattering profiles to snow depth and snow density: an analytical radiative transfer analysis and the implications for remote sensing of snow

Lidar multiple scattering measurements provide the probability distribution of the distance laser light travels inside snow. Based on an analytic two-stream radiative transfer solution, the present study demonstrates why/how these lidar measurements can be used to derive snow depth and snow density. In particular, for a laser wavelength with little snow absorption, an analytical radiative transfer solution is leveraged to prove that the physical snow depth is half of the average distance photons travel inside snow and that the relationship linking lidar measurements and the extinction coefficient of the snow is valid. Theoretical formulas that link lidar measurements to the extinction coefficient and the effective grain size of snow are provided. Snow density can also be derived from the multi-wavelength lidar measurements of the snow extinction coefficient and snow effective grain size. Alternatively, lidars can provide the most direct snow density measurements and the effective discrimination between snow and trees by adding vibrational Raman scattering channels.

Direct Measurement of the Local Density of Optical States in the Time Domain.

One of the most fundamental and relevant properties of a photonic system is the local density of optical states (LDOS) as it defines the rate at which an excited emitter dissipates energy by coupling to its surrounding. However, the direct determination of the LDOS is challenging as it requires measurements of the complex electric field of a point dipole at its own position. We introduce here a near-field setup which can measure the terahertz electric field amplitude at the position of a point source in the time domain. From the measured amplitude, the frequency-dependent imaginary component of the electric field can be determined and the LDOS can be retrieved. As a proof of concept, this setup has been used to measure the partial LDOS (the LDOS for a defined dipole orientation) as a function of the distance to planar interfaces made of gold, InSb, and quartz. Furthermore, the spatially dependent partial LDOS of a resonant gold rod has been measured as well. These results have been compared with analytical results and simulations. The excellent agreement between measurements and theory demonstrates the applicability of this setup for the quantitative determination of the LDOS in complex photonic systems.

Characterization of the collisional frequency shift in an atomic fountain clock using absorption imaging

The collisional frequency shift is a dominant contribution to the uncertainty of many caesium fountain clocks. Minimizing the effect can be difficult, as lowering the atomic density comes at the cost of a reduced signal-to-noise ratio. Also, it is typically not atomic density, but total atom number that is measured in the experiment, which can lead to a potential measurement bias. In this paper, we describe a direct measurement of the atomic density using absorption imaging of the atomic cloud. For the caesium fountain clock, NRC-FCs2, at the National Research Council Canada, these measurements have led to a reduction in the uncertainty due to the collisional shift by a factor of 10.

Direct Measurement of Acoustic Spectral Density and Fractional Topological Charge

LDOS is a fundamental spectral property that plays a central role in various physical phenomena, such as wave-matter interactions and spontaneous emissions. The role of LDOS in acoustics was uncovered only in recent years and the measurement of acoustic LDOS has not yet been achieved. Here, we report on the direct measurement of the LDOS in acoustic systems. The acoustic LDOS is quantified here through the measurement of the volume flow rate and the acoustic pressure with a local excitation-probe configuration. Based on this method, we detect the LDOS in the one-dimensional acoustic Su-Schrieffer-Heeger model and observe the fractional topological charge of the system. Our work unveils the role of the LDOS in acoustic phenomena and paves the way toward characterizing and tailoring the LDOS in acoustic systems, which holds promise for applications in acoustic emission control, energy localization, and wave-matter interaction.

Constraining the physics of star formation from CIB-cosmic shear cross-correlations

ABSTRACT Understanding the physics of star formation is one of the key problems facing modern astrophysics. The cosmic infrared background (CIB), sourced by the emission from all dusty star-forming galaxies since the epoch of reionization, is a complementary probe to study the star formation history, as well as an important extragalactic foreground for studies of the cosmic microwave background. In this paper, we make high signal-to-noise measurements of the cross-correlation between maps of the CIB from the Planck experiment, and cosmic shear measurements from the Dark Energy Survey and Kilo-Degree Survey. Cosmic shear is a direct tracer of the matter distribution and thus we can use its cross-correlation with the CIB to directly test our understanding of the link between the star formation rate (SFR) density and the matter density. We use our measurements to place constraints on a halo-based model of the SFR that parametrizes the efficiency with which gas is transformed into stars as a function of halo mass and redshift. These constraints are enhanced by using model-independent measurements of the bias-weighted SFR density extracted from the tomographic cross-correlation of galaxies and the CIB. We are able to place constraints on the peak efficiency at low redshifts, $\eta =0.445^{+0.055}_{-0.11}$, and on the halo mass at which this peak efficiency is achieved today log10(M1/M⊙) = 12.17 ± 0.25. Our constraints are in excellent agreement with direct measurements of the SFR density, as well as other CIB-based studies.

X‐ray computed tomography of deep‐sea clay as tools to detect rare earth elements and yttrium enrichment

AbstractPelagic clay that contains rare‐earth elements and yttrium (REY) at over 2000 ppm (termed “highly REY‐rich mud”) has been reported from a few areas in the western North Pacific Ocean through focused geochemical analyses. Those REY are carried by biogenic calcium phosphate, suggesting that the formation of highly REY‐rich mud involves enhanced biological productivity. However, detecting REY enrichment in sediment is time‐consuming, and the global significance of the formation of REY‐rich mud is still under debate. Here we perform x‐ray computed tomography (CT) analyses on cores recovered around Minamitorishima Island and demonstrate the positive correlation with highly REY‐rich mud and high CT numbers of the sediment. The variation of the CT number matches the wet bulk density. Further quantitative analyses using direct measurements of density and geochemistry suggest that a grain density increase and a porosity decrease due to the REY‐carrying biogenic apatite are essential to explain the high CT numbers in the REY‐enriched layer. While the chemical composition itself is of minor importance to elevate the CT numbers, our results suggest that x‐ray CT can be a proxy for highly REY‐rich mud.

Revealing the topological phase diagram of ZrTe5 using the complex strain fields of microbubbles

Topological materials host robust properties, unaffected by microscopic perturbations, owing to the global topological properties of the bulk electron system. Materials in which the topological invariant can be changed by easily tuning external parameters are especially sought after. Zirconium pentatelluride (ZrTe5) is one of a few experimentally available materials that reside close to the boundary of a topological phase transition, allowing the switching of its invariant by mechanical strain. Here, we unambiguously identify a topological insulator–metal transition as a function of strain, by a combination of ab initio calculations and direct measurements of the local charge density. Our model quantitatively describes the response to complex strain patterns found in bubbles of few layer ZrTe5 without fitting parameters, reproducing the mechanical deformation-dependent closing of the band gap observed using scanning tunneling microscopy. We calculate the topological phase diagram of ZrTe5 and identify the phase at equilibrium, enabling the design of device architectures, which exploit the topological switching characteristics of the system.

The Potential for a Networked Ionospheric Sounding Constellation

AbstractA novel networked sounding constellation mission concept is proposed. Radio sounding is the original sensing method that proved the existence of the ionosphere. Satellite‐borne sounders provided the first global observations of the terrestrial ionosphere and plasmasphere, as well as the Martian ionosphere. Networked sounding, where signals are transmitted and received across multiple instruments, has been used on the ground since the first days of ionospheric observation. This paper proposes networked sounding from space, to produce measurements of the F‐layer peak, enhanced E‐layers, regions of turbulent structuring, the topside scale height (or transition height) and potentially the plasmapause. The principal advantage of sounding over other methods is direct measurement of the peak density, where a networked implementation greatly increases spatial data coverage because it provides multiple unique signal paths through the ionosphere at different frequencies. Major advances in satellite software‐defined radio, deployable antennas, signal processing and data analysis have been made in recent years, such that a networked sounding constellation could be built at realistic cost—either as a hosted payload on commercial buses or on dedicated CubeSats.

GPR method for continuous monitoring of compaction during the construction of railways subgrade

Design solutions used in the construction of roadbeds require homogeneity of the properties of the structure over long sections. At the same time, the verification of quality of the construction of railways and highways roadbeds is based on local determination of density and other mechanical characteristics of structural layers. In this work, to overcome this drawback, a method is proposed for continuous determination of the properties of structural layers under construction. It is based on the GPR method calibrated by direct measurements of the construction material density. The algorithms of the developed method are implemented in the form of a computer code adapted for use in the construction of roadbeds of railways. The effectiveness of the developed method and computer code were tested on the section of a roadbed under construction. Field measurements were carried out using the series “OKO” GPR and the antenna unit operating at a frequency of 1700 MHz to estimate the density of the subgrade soil in various depth sections. A good agreement is shown between the GPR data and the direct measurements. The obtained radargrams were used to estimate the density of the subgrade soil at depths up to 0.6 m. A good matching between the results obtained by processing the GPR data with the developed computer code and the ones obtained by direct measurements is demonstrated.

Exploring extreme magnetization phenomena in directly driven imploding cylindrical targets

This paper uses extended-magnetohydrodynamics (MHD) simulations to explore an extreme magnetized plasma regime realizable by cylindrical implosions on the OMEGA laser facility. This regime is characterized by highly compressed magnetic fields (greater than 10 kT across the fuel), which contain a significant proportion of the implosion energy and induce large electrical currents in the plasma. Parameters governing the different magnetization processes such as Ohmic dissipation and suppression of instabilities by magnetic tension are presented, allowing for optimization of experiments to study specific phenomena. For instance, a dopant added to the target gas-fill can enhance magnetic flux compression while enabling spectroscopic diagnosis of the imploding core. In particular, the use of Ar K-shell spectroscopy is investigated by performing detailed non-LTE atomic kinetics and radiative transfer calculations on the MHD data. Direct measurement of the core electron density and temperature would be possible, allowing for both the impact of magnetization on the final temperature and thermal pressure to be obtained. By assuming the magnetic field is frozen into the plasma motion, which is shown to be a good approximation for highly magnetized implosions, spectroscopic diagnosis could be used to estimate which magnetization processes are ruling the implosion dynamics; for example, a relation is given for inferring whether thermally driven or current-driven transport is dominating.

Direct Measurement of Black Carbon's Effective Density by Using a Dma-Cpma-Sp2 System and Implications for Black Carbon's Shape Variations

Direct Measurement of Black Carbon's Effective Density by Using a Dma-Cpma-Sp2 System and Implications for Black Carbon's Shape Variations

The resonant acoustic signatures of lithic debitage

Acoustic methods to search for submerged archaeological sites have shown that concentrations of knapped flint produce a visible acoustic response in chirp sonar profiles in a variety of geographical settings. Field tests and simulations have suggested that the submerged lithic signal is due to acoustic resonances of the flaked stone. We model and measure the resonant acoustic signatures of chert, obsidian, metavolcanic, and granitic lithic debitage. Struck lithics produce multiple resonant peaks under 30 kHz, with high quality factors that decrease with material coarseness. We use a combination of the finite element and boundary element methods to model the natural vibrations of lithic debitage in both air and water. Direct measurement of lithic material density and adjustment of the Young’s modulus and Poisson’s ratio provide excellent correspondence between measured and modeled resonances. Using a coupled finite element and boundary integral method, we model the acoustic scattering return of individual lithics in water as a function of frequency and incidence angle. We find the strongest resonant signal between 8 and 16 kHz for a collection of lithic debitage. Results indicate that the lithic resonance signal is highly directional, with target strength up to −20 dB when excited at optimal angles. For a flat-laying lithic, target strength at normal incidence is, on average, 10 dB lower than the strongest signal, typically found 55°±18° from normal incidence. We suggest that the best way to detect submerged lithics may not be through standard mono-static sub-bottom profiling with a direct downward pulse, but with a chirp pulse sent and received at an angle with respect to the sea bottom.

Cratering Records in the Chang'e‐5 Mare Unit: Filling the “Age Gap” of the Lunar Crater Chronology and Preparation for Its Recalibration

AbstractThe Moon is the cornerstone for dating planetary surfaces as it is the only planetary body that has been sampled multiple times from multiple places. The major deficiencies of the lunar crater chronology function are the somewhat limited number of calibration points and data gaps, especially in the ∼1–3 Ga segment. China's Chang'e‐5 mission recently returned samples from a young nearside mare, whose age is estimated to be in that age gap, providing a long‐awaited opportunity for recalibrating the lunar chronology. Here, we report a direct density measurement of impact craters ≥1 km in diameter of Chang'e‐5 mare unit, as (1.696 ± 0.221) × 10−3 km−2. The Chang'e‐5 mare deposits are estimated as ∼1.3–2.7 Ga old in various lunar chronologies, younger than all collected Apollo/Luna basalts. Accurate radio‐isotopic ages of Chang'e‐5 samples can be combined with our crater density measurement for a recalibration of lunar chronology.

Experimental investigation and gyrokinetic simulations of multi-scale electron heat transport in JET, AUG, TCV

Tokamaks dominated by electron heating like ITER could possibly suffer from the consequences of electron temperature gradient (ETG) mode destabilisation, which could develop a turbulent electron heat flux capable of setting an upper limit to the achievable electron temperature peaking, resulting in a degradation of the fusion performance. An effort is carried out in this paper to collect and compare the results of dedicated plasma discharges performed during the last few years at three of the major European tokamaks, TCV, AUG and JET, by analysing the electron heat transport for cases presumably compatible with ETGs relevance, given the actual theoretical understanding of these instabilities. The response of the electron temperature profiles to electron heat flux changes is experimentally investigated by performing both steady state heat flux scans and perturbative analysis by radio frequency heating modulation. The experimental results are confronted with numerical simulations, ranging from simple linear gyrokinetic (GK) or quasi-linear runs, to very computationally expensive nonlinear multi-scale GK simulations, resolving ion and electron scales at the same time. The results collected so far tend to confirm the previously emerging picture, indicating that cases with a proper balance of electron and ion heating, with similar electron and ion temperatures and sufficiently large ETG, could be compatible with a non negligible impact of ETGs on the electron heat transport. The ion heating destabilises ETGs not only by increasing the ion temperature but also thanks to the stabilisation of ion-scale turbulence by a synergy of fast ions and E × B shearing, which are in some cases associated with it. The stabilising effect of plasma impurities on ETGs is still under investigation by means of multi-scale GK simulations, and also direct experimental measurements of density and temperature fluctuations at electron scales would be needed to ultimately assess the impact of ETGs.

Getting to the root of the problem: improving measurements of mangrove belowground production and carbon sequestration.

This article is a Commentary on Arnaud et al. (2021), 232: 1591–1602.