Physical Constants Research Articles

Dissociation extraction: Theoretical foundations and applications

Dissociation extraction (DE) is a separation method that has been known for many decades but is not yet widely used in industry. However, there are a number of applications for which DE may be applied, for example, for new biorefinery separations. To facilitate future applications, we derived a new shortcut method for DE processes and demonstrated its application in the conceptual design of a separation process for acidic and basic organic mixtures. The new method allows for the calculation of the minimum energy requirement and a fast comparison of dissociation extraction with other separation methods. The shortcut method was validated using experimental data from the literature and is easy to implement because it is based only on the physical distribution coefficients and dissociation constants of the acids or bases to be separated.In the second part of this paper, we identify several areas that require effective separation techniques, where dissociation extraction can have an impact. These include biorefinery separation, polymer recycling, and fatty acid fractionation.In conclusion, we hope to promote DE as a known but less-used separation method for difficult separation problems in both fossil-based and bio-based sustainable chemical products.

Hamilton cycles in pseudorandom graphs

Finding general conditions which ensure that a graph is Hamiltonian is a central topic in graph theory. An old and well-known conjecture in the area states that any d-regular n-vertex graph G whose second largest eigenvalue in absolute value λ(G) is at most d/C, for some universal constant C>0, has a Hamilton cycle. In this paper, we obtain two main results which make substantial progress towards this problem. Firstly, we settle this conjecture in full when the degree d is at least a small power of n. Secondly, in the general case we show that λ(G)≤d/C(log⁡n)1/3 implies the existence of a Hamilton cycle, improving the 20-year old bound of d/log1−o(1)⁡n of Krivelevich and Sudakov. We use in a novel way a variety of methods, such as a robust Pósa rotation-extension technique, the Friedman-Pippenger tree embedding with rollbacks and the absorbing method, combined with additional tools and ideas.Our results have several interesting applications. In particular, they imply the currently best-known bounds on the number of generators which guarantee the Hamiltonicity of random Cayley graphs, which is an important partial case of the well known Hamiltonicity conjecture of Lovász. They can also be used to improve a result of Alon and Bourgain on additive patterns in multiplicative subgroups.

An analytical method for increasing the accuracy of the value of the Newtonian constant of gravitation

Despite hundreds of measurements of the Newtonian constant of gravitation, its accuracy remains very low. Over the past 55 years, it has improved by only one order of magnitude - from four to five digits after the decimal point. In this study, a new analytical method for improving the accuracy of estimating the value of the Newtonian constant of gravitation is proposed. Using the proposed method, its accuracy is increased by 7 orders of magnitude relative to the CODATA 2022 data. The method is based on the analytical estimate of the Planck mass, length, and time, with an accuracy of values ​​that is 5 orders of magnitude higher than their accuracy according to CODATA 2022. Such a significant increase in the accuracy of the Planck mass, length, and time values ​​was made possible by the integrated use of: 1) precision formulas for the Planck momentum; 2) representation of the speed of light in a vacuum through the Planck length and time; 3) the De Broglie principle: the moments of the Planck mass, leptons, and baryons are equal to each other; 4) high-precision characteristics of the proton. The method of analytical evaluation of Planck mass, length, and time allowed us to connect the main characteristics of the hypothetical virtual Planck particle with the main characteristics of the proton. Increasing the accuracy of the proton characteristics will entail increasing the accuracy of Planck mass, length, and time. Accordingly, the accuracy of the value of the Newtonian gravitational constant and all physical constants that can be represented through Planck mass, length, and time will be increased, which is especially important in light of the decisions of the 26th General Conference on Weights and Measures.

Establishment of an absolute measurement of the reference air kerma rate for HDR 192Ir brachytherapy sources

Before this study, no institution in China had undertaken the calculation and official establishment of reference values for the reference air kerma rate associated with high-dose rate 192Ir sources used in brachytherapy. This research, carried out at the National Institute of Metrology (NIM) in China, has successfully established an 192Ir reference radiation facility. Consequently, it has achieved the absolute measurement of the reference air kerma rate for high-dose rate brachytherapy using 192Ir sources. For this study, a medical afterloader machine was acquired. The radiation source employed was a high-dose rate 192Ir source for brachytherapy, produced by HTA Co., Ltd. A reference graphite cavity ionization chamber with a volume of 100 cm3 was designed to serve as the ionization chamber for absolute measurements. The determination of various correction factors and physical constants was achieved through a method that combines Monte Carlo simulations with experimental techniques. The study successfully accomplished the absolute measurement of the reference air kerma rate for the high-dose rate brachytherapy 192Ir radiation source. The expanded uncertainty of the measurement results was 0.72% (k = 2). The relative standard deviation for the RAKR of the same 192Ir radiation source was 0.073%. This study marks a significant advancement in the field of radiation therapy in China, particularly in the accurate dosimetry for brachytherapy using high-dose rate 192Ir sources. The study will contribute to the BIPM.RI(I)-K8 international comparison, organized by the Bureau International des Poids et Mesures (BIPM), thus facilitating the international recognition of the measurement values.

Study of the effect of CdCl2 introduction on the high temperature activation treatment of CdTe:As polycrystalline thin films

V-doped CdTe polycrystalline films can achieve both doping activation and defect passivation by high-temperature CdCl2 heat treatment, but this requires simultaneous modulation of the amount of CdCl2 introduced to obtain high-quality films. It is found that increasing the CdCl2 introduction does not change the physical phase structure and lattice constant of CdTe:As thin films, but promotes grain recrystallisation, and can promote the formation of A-center, and inhibit the formation of Cd vacancy (VCd) defects, as well as the formation of deep energy level defects. The results provide guidance for the improvement of high-temperature CdCl2 heat treatment of V-doped CdTe polycrystalline thin films.

A Fundamental Problem in Physics: (Mass vs Electric Charge)

In modern physics there exist opposite concepts regarding the constancy and the variability of two major properties of the electron: its mass and its electric charge. Section 1: Mainstream physicists consider the mass of the electron as varying with its velocity while its electric charge as a fundamental constant of physics. Section 2: On the other hand, many other physicists maintain the opposite concept: the mass of the electron is invariant in all physical conditions while its electric charge is variable. Section 3: In the case when the mass is invariant, a mathematical expression for the variability of the electric charge of the electron in external fields will be deduced. Section 4: A thought experiment to demonstrate the variability of the electric charge of the electron in a changing magnetic field. Section 5: Discussions: (1) Why is the electric charge changed in external field? 2) Renormalizing the mass is problematic 3) Renormalizing the electric charge is innovative 4) The mystery of the mass of the muon. 5) The controversial concept of time dilation.

Toward Absolute Quantification of Soluble Proteins via Proton Nuclear Magnetic Resonance Spectroscopy: Total Protein Concentration in Blood Plasma.

For absolute protein quantification using nuclear magnetic resonance (NMR) spectroscopy, we considered proteins as homopolymers and effective amino acid (AA) residues (AAREff) as monomer units. For diverse classes of proteins, we determined the AAREff molecular weight as 111.5 ± 3.2 Da and the number of hydrogens per AA as 7.8 ± 0.2. Their ratio of 14.3 ± 0.3 (g/LP)/(mol/LH) remains constant across various protein classes and is equivalent to Kjeldahl's nitrogen-to-protein conversion constant of 5.78 ± 0.29 gN/gP. By analogy to the Kjeldahl method, we suggest that the total integral of a 1H NMR solution protein spectrum could be used for total protein quantification. We synthesized low-resolution protein spectra from the weighted sums of individual AA spectra and compared them with experimental spectra. In the methyl region, the ratio of the protein mass to the total number of protons in the synthetic spectra (corrected for the chemical shift mismatch) was ∼1 (mg/mL)/mM, which agrees with an earlier reported experimental ratio for urine (1.05 ± 0.06 (mg/mL)/mM). For human blood plasma, in the methyl region, we found empirical ratios of 1.115 ± 0.006 (mg/mL)/mM (using 96 patient samples) and 1.121 ± 0.011 (mg/mL)/mM for the NIST plasma standard. This numerical agreement points to universal conversion constants, i.e., protein mixtures with unknown compositions could be quantified without the need for calibration standards by measuring the millimolar proton concentration within the methyl region of the NMR spectrum using the same conversion constant.

Maximum acceleration and quantum clock: on the existence of a new universal constant

In the pseudo-Euclidean Minkowski space, the four-dimensional volume element is invariant under Lorentz transformations. By hypothesising that in this space there is a minimum volume, it is possible to demonstrate the existence of a maximum acceleration. The volume element cannot be derived from the theory and must be obtained through direct measurement, thus it assumes the role of a bona fide universal constant. Two different estimates of the elementary volume are given, which differ by several orders of magnitude: the first is obtained in a pseudo-Euclidean space for particles with mass, and the second represents an absolute minimum volume, independent of the mass.

ЗОРЯНЕ ВИПРОМІНЮВАННЯ У ГАЛАКТИЧНОМУ ЦИКЛІ

The existence of the Universe presupposes the circulation of energy emitted by stars between galaxies and the cosmic environment. The third galactic process presented in the article "Life of Galaxies in the Observable Universe" contains a fragment associated with the release of energy by stellar photons propagating through space. In this report, it is suggested that the release of energy by quanta is carried out through two channels. The first is the transfer of energy to hypothetical particles of the subtle component of dark matter formed from the paired unification of microwave quanta. The second channel is the release of the bulk of the photons' energy to the vacuum structures. The distribution of the returned energy over the two channels is determined by its participation in processes at two different levels. The first level is electromagnetic processes occurring in the plasma of stellar atmospheres. The second is the participation of the returned energy in the processing of stellar waste in galactic centers, when the latter are in the quasar phase and destroy the nuclei of atoms of old stars into the original particles. The participation of vacuum in the reception of energy and its transfer to galaxies means that the vacuum near large masses will be distinguished by an increased density of its energy. The latter should be reflected in the physical constants whose values depend on the state of the vacuum. Such constants include, for example, the electric and magnetic constants. Therefore, one should expect a shift in the spectral lines of radiation of atoms near the nuclei of quasars relative to the spectral lines of radiation emanating from points of the same galaxies, but remote from their centers. The latter means that the indicated difference in redshifts within galaxies can introduce additional errors in determining the distances to them. Classical electrodynamics and the above assumption indicate the dependence of the speed of light on the point of its determination. It is concluded that some physical constants depending on the local density of vacuum energy will be constant only conditionally.

Quantum geometric approach: Nature and characteristics of emerged quantum-conditioned spacetime curvatures on three-sphere

General relativity (GR) in its current classical formulation is fundamentally different from quantum mechanics (QM). We argue that the everlasting battle for exploring and understanding the Universe and then privileging a consistent perception of reality is therefore awaiting a consolidator rather than a conqueror. This should be capable of either unifying these two different benchmarks or at least bringing one closer to another! The latter conservatively describes the consolidating quantum geometric approach, which combines generalization of QM to relativistic energies and gravitational fields and continuous Riemann to discretized Finsler geometry. We found that this type of quantum geometric approach seems to unveil additional quantum-conditioned spacetime curvatures (QCC), sources of gravitation), which obviously could not be disclosed in Einstein’s GR, especially at large scales. This study introduces analytical and numerical analyses of QCC. We conclude that (i) nature and characteristics of QCC are fundamentally distinguishable from the classical GR’s spacetime curvatures, (ii) the QCC are intrinsic, real and essential, i.e. not artifacts that would be removed in a certain coordinate transformation and (iii) the magnitude of QCC are nonnegligible to be underestimated. We also conclude that the spacetime at quantum scales seems to be no longer smooth or continuous so that the proposed quantum geometric approach would be regarded as a novel mathematical framework for the emergence of quantum gravity. Last but not least, a maximal proper force is predicted as a new physical constant, which is responsible for the maximal and gravitational acceleration of a quantum particle that would live in the emerged spacetime curvatures. Thereby, the quantum geometric nature of QCC can be accessed and assessed.

Birge ratio method for modeling dark uncertainty in multivariate meta-analyses and inter-laboratory studies

In the paper, we introduce a new approach for combining multivariate measurements obtained in individual studies. The procedure extends the Birge ratio method, a commonly used approach in physics in the univariate case, such as for the determination of physical constants, to multivariate observations. Statistical inference procedures are derived for the parameters of the multivariate location-scale model, which is related to the multivariate Birge ratio method. The new approach provides an alternative to the methods based on the application of the multivariate random effects model, which is commonly used for multivariate meta-analyses and inter-laboratory comparisons. In two empirical illustrations, we show that the introduced multivariate Birge ratio approach yields confidence intervals for the elements of the overall mean vector that are considerably narrower than those obtained by the methods derived under the multivariate random effects model.

Grating pitch comparator traceable to the Cr atom transition frequency

Calibration of the grating pitch typically requires metrological instruments or diffraction techniques. The traceability and stability demands for laser wavelength in these techniques present substantial challenges for on-site grating calibration. This paper introduces a novel traceability approach to grating pitch calibration using a grating pitch comparator that utilizes the transition frequency of the chromium. The chromium transition frequency is converted into a chromium grating through atom lithography, establishing a self-traceable length standard dCr = 212.7787 ± 0.0049 nm. Calibration of the test grating’s pitch is achieved by comparing the phase shift caused by the simultaneous movement of the chromium grating and the test grating. By using the dCr, this approach combines the high-accuracy of fundamental physical constants with the environmental stability of grating interferometers, eliminating the need for measuring laser wavelength, air refraction, diffraction angles. It significantly enhances the precision and makes more straightforward and portable, crucial for facilitating traceable on-site grating measurements.

Study of different theories of thermoelasticity under the propagation of Rayleigh waves in thermoelastic medium

The present research is on the propagation of Rayleigh waves in a homogenous thermoelastic solid half-space by considering the compact form of six different theories of thermoelasticity. The medium is subjected to an insulated boundary surface that is free from normal stress, tangential stress, and a temperature gradient normal to the surface. After developing a mathematical model, a dispersion equation is obtained with irrational terms. To apply the algebraic method, this equation must be converted into a rational polynomial equation. From this, only those roots are filtered out, which has satisfied both of the above equations for the propagation of waves decaying with depth. With the help of these roots, different characteristics are computed numerically, like phase velocity, attenuation coefficient, and path of particles. Various particular cases are compared graphically by using phase velocity and attenuation coefficient. The elliptic path of surface particles in Rayleigh wave propagation is also presented for the different theories using physical constants of copper material for different depths and thermal conductivity.

A Dynamic Smagorinsky Model for Horizontal Turbulence Parameterization in Tropical Cyclone Simulation

AbstractThe horizontal turbulence parameterization is vital for the intensity and structure forecasting of tropical cyclone (TC) in numerical weather prediction (NWP) models. The default two‐dimensional (2D) standard Smagorinsky model with a single universal constant in Weather and Research Forecasting (WRF) model has been proven to be over dissipative for TC, leading to underprediction of TC intensity. This study provides the first attempt to implement the physically based 2D dynamic Smagorinsky model (DSM) for horizontal turbulence parameterization in WRF model for TC forecasts. The DSM dynamically computes the Smagorinsky coefficient as a function of the resolved flow during the simulation, avoiding the need to prescribe the coefficient a prior. The test results of the DSM in a TC NWP model show that the DSM can significantly improve the wind intensity forecasts compared to the standard Smagorinsky model.

Optical parameters and gamma shielding quality of sodium-borate glasses: The relative contribution of Bi2O3, SrO, and Li2O

The optical quality and compositional flexibility of borate glasses make them attractive materials for optical applications, nuclear waste containment, transparent radiation shields and many other applications in the nuclear and allied industries. This study presents the physical, optical, and gamma transmission data of the sodium borate glass structure: 75B2O3 – 15Na2O – 9.5x – 0.5Nd2O3; for x = Bi2O3 (BiNd), SrO (SrNd), and Li2O (LiNd). The glasses were prepared using the traditional melt-and-quench technique. The influence of Bi2O3, SrO, and Li2O on the physical attributes, optical constants, and gamma radiation interaction coefficients was probed using standard laboratory procedures and software. The density of BiNd, SrNd, and LiNd was 3.32, 2.43, and 2.24 g/cm3, respectively. The molar volume of the glasses followed the trend: BiNd > SrNd > LiNd. The optical constants of the glasses, such as refractive index, metallization criterion, molar refractivity, molar polarizability, reflectance loss, and optical transmission, showed a wide fluctuation with respect to glass composition. The values of the gamma mass attenuation coefficients for 15 keV–15 MeV photons were in the range 0.0316–45.0225 cm2/g for BiNd, 0.0206–5.4940 cm2/g for SrNd, and 0.0184–3.4603 cm2/g for LiNd. Generally, density has a positive correlation with the gamma absorption prowess of the investigated xNd glasses. A correlation between the optical and shielding parameters was highlighted in this study. The xNd glasses, especially SrNd and BiNd, are preferred as transparent radiation protection barriers, in contrast to some conventional Pb-based glasses, from environmental and public health perspectives. This glass composition is therefore unique and its properties are essentially useful in optical and radiation technologies.

A Two-Dimensional Amplitude Study of True-Amplitude Time Migration and Time Remigration – 2.5-D Synthetic Examples

In this synthetic study, we present semi-automatically picked true-amplitude comparisons after time migration and time remigration (Tygel et al.,1996; and Oliveira et al.,2023). Since the examples considered are synthetic, emphasis is put on the generally disregarded dimensional aspects of the amplitudes that are modeled to simulate compressional-only seismic data when using a Kirchhoff a p proximation. By bearing in mind in this work that theoretical amplitudes work as “densities”, we show that when comparisons of true-amplitude weighted diffraction-stack time migration and weighted isochrone-stack time remigration are performed, in order to “correct” the dimensions involved certain multiplicative physical constants must come into play and that must be effectively dealt with, for plotting reasons.

Constraints on the variation of physical constants, equivalence principle violation, and a fifth force from atomic experiments

The aim of this paper is to derive limits on various forms of “new physics” using atomic experimental data. Interactions with dark energy and dark matter fields can lead to space-time variations of fundamental constants, which can be detected through atomic spectroscopy. In this study, we examine the effects of a varying nuclear mass mN and nuclear radius rN on two transition ratios: the comparison of the two-photon transition in atomic hydrogen with the hyperfine transition in Cs133 based clocks, and the ratio of optical clock frequencies in Al+ and Hg+. The sensitivity of these frequency ratios to changes in mN and rN enables us to derive new limits on the variations of the proton mass, quark mass, and the QCD parameter θ. Additionally, we consider the scalar field generated by the Yukawa-type interaction of feebly interacting hypothetical scalar particles with Standard Model particles in the presence of massive bodies such as the Sun and Moon. Using the data from the Al+/Hg+, Yb+/Cs, and Yb+(E2)/Yb+(E3) transition frequency ratios, we place constraints on the interaction of the scalar field with photons, nucleons, and electrons for a range of scalar particle masses. We also investigate limits on the Einstein equivalence principle (EEP) violating term (c00) in the Standard Model extension (SME) Lagrangian and the dependence of fundamental constants on gravity. Published by the American Physical Society 2024

Improved frequency shift compensation technique and pulse sequence for multi-loop atom interference experiments

With the rapid development of atom interference technology, multi-loop atom interferometers are widely used in the high-precision measurement of various physical constants and testing of various gravity-related effects. However, in ground-based multi-loop atom interference experiments, the systematic error contribution by classical effects is an important factor that affects the experimental measurement accuracy and gravitational effect detection. Based on this, we used the atomic wave-function evolution-phase accumulation method to provide a high-order interference phase of multi-loop atom interferometers in an inhomogeneous gravitational field containing Earth’s rotation. Furthermore, we propose a new scheme that combines optimised frequency-shift compensation technology with an improved pulse sequence to eliminate systematic errors due to the gravity gradient, Earth’s rotation, and their coupling effect with the pulse duration, as well as the coupling effect of laser detuning with the pulse duration. This study lays a theoretical foundation for experiments on multi-loop atom interferometers with higher precision.

Probing proton-to-electron mass ratio variability with QSO 0347–383 spectra

We introduce a new approach for detecting potential cosmological changes in the proton-to-electron mass ratio (µ) by studying the absorption lines of molecular hydrogen (H2) in the high-redshift quasar QSO 0347–383. By comparing these observations with high-precision laboratory data, we determine a variation of ∆µ/µ = (0.120 ± 0.144) × 10−8 at zabs = 3.025. This highly precise result offers valuable insights into the constancy of fundamental physical constants over extended cosmic periods.

Ultraviolet astronomical spectrograph calibration with laser frequency combs from nanophotonic lithium niobate waveguides

Astronomical precision spectroscopy underpins searches for life beyond Earth, direct observation of the expanding Universe and constraining the potential variability of physical constants on cosmological scales. Laser frequency combs can provide the required accurate and precise calibration to the astronomical spectrographs. For cosmological studies, extending the calibration with such astrocombs to the ultraviolet spectral range is desirable, however, strong material dispersion and large spectral separation from the established infrared laser oscillators have made this challenging. Here, we demonstrate astronomical spectrograph calibration with an astrocomb in the ultraviolet spectral range below 400 nm. This is accomplished via chip-integrated highly nonlinear photonics in periodically-poled, nano-fabricated lithium niobate waveguides in conjunction with a robust infrared electro-optic comb generator, as well as a chip-integrated microresonator comb. These results demonstrate a viable route towards astronomical precision spectroscopy in the ultraviolet and could contribute to unlock the full potential of next-generation ground-based and future space-based instruments.