Important Quantities Research Articles

The impact of contact-network structure on important epidemiological quantities of infectious disease transmission and the identification of the extremes.

We developed an individual-based stochastic model to simulate the spread of an infectious disease on all possible contact-networks of size between six and nine nodes. We assessed systematically the impact of the change in the population contact structure on four important epidemiological quantities: i) the epidemic duration, ii) the maximum number of infected individuals at a time point during the epidemic, iii) the time at which the maximum number of infected individuals is reached, and iv) the total number of individuals that have been infected during the epidemic. We identified the networks that maximise and minimise each of these quantities in the case of an epidemic outbreak. Chain-like networks minimise the peak and final epidemic size, but the disease spread is slow on such contact structures which leads to the maximisation of the epidemic duration. Star-like networks maximise the time to the peak whereas highly connected networks lead to faster disease transmission, and higher peak and final epidemic size. While the pairwise relationship of most of the quantities becomes almost linear, or inverse linear, as the network connectivity increases and approaches the complete network, where every individual is connected to each other, the relationships are non-linear towards networks of low connectivity. In particular, the pairwise relationship between the final epidemic size and other quantities is changed in a 'bow-shaped' manner. There is a strong inverse linear relationship between epidemic duration and peak epidemic size with increasing network connectivity. The (inverse) linear relationships between quantities are more pronounced in cases of high disease transmissibility. All the values of the quantities change in a non-linear way with the increase of network connectivity and are characterised by high variability between networks of the same degree. The variability decreases as network connectivity increases.

Magnetohydrodynamics of couple stress Casson fluid flow in a channel with stretching wall in the presence of dissipative and radiative heat transfer

AbstractThis paper investigates the unsteady magnetohydrodynamic flow of a couple stress Casson fluid between two parallel sheets where the heat transfer mechanism is incorporated with the influences of heat radiation, viscous dissipation, and Joule heating. The fluid flow is induced due to bi‐directional stretching of the lower sheet of the channel. The mathematical model of the physical problem is governed by highly nonlinear coupled partial differential equations with boundary conditions that are then transformed into highly nonlinear ordinary differential equations with boundary conditions using well‐defined similarity variables. The authors have used the well‐known computational technique called the spectral successive linearization method (SLM) to solve the obtained ordinary differential equations subject to the boundary conditions. Graphs and tables show the effects of non‐dimensional parameters on the important physical quantities such as the velocity and temperature profiles, and coefficients of skin‐frictions and heat transfer. The quadratic regression method is used to perform statistical analysis of Nusselt number and skin friction coefficients. The present investigation has significant applications in different problems of biomedical engineering, clinical sciences, industrial manufacturing processes, and so forth.

HIV transactivation: Stochastic modeling for studying the effects of BET inhibitors on the modulation of P-TEFb levels

Latency is the major obstacle in eradicating HIV from infected patients. Recent studies have shown that BET protein inhibitors can successfully reverse this latency by inhibiting the binding of BET proteins with positive cellular cofactor P-TEFb. Thus, availability of P-TEFbs plays an important role in HIV transactivation. However, in cells of our immune system which are primarily infected by the virus, number of P-TEFb is very low and is considered as one of the factors in inducing viral latency. At such small numbers of P-TEFb, the internal fluctuations can have a decisive role in the cell fate decision and fluctuations in the P-TEFb levels can switch the HIV to either a state of active replication or to a state of latency. Aimed at quantitative understanding of how BET inhibitors affect the statistics of P-TEFb level, we develop a coarse-grained stochastic model. However, the interaction between P-TEFb and BET proteins makes the problem analytically challenging. To address the nonlinearity arising due to such interactions, we use Langevin equation based approach to study the statistics of steady-state P-TEFb levels and explore the variations of some of the important quantities such as noise and fano factor associated with P-TEFb as well as correlations between BET and P-TEFb levels with model parameters. The analytic results derived exhibit that these quantities, in general, show non-monotonic response with respect to the parameters of the model. The results derived will be helpful in estimating the model parameters as well in identifying the pathways that can be intervened for effective HIV transactivation.

Lorentz-violating Yukawa theory at finite temperature

This paper addresses Yukawa theory, focusing on the scattering between two identical fermions mediated by an intermediate scalar boson, considering the effects of thermal contributions and Lorentz symmetry breaking. Temperature is introduced into the theory through the thermofield dynamics formalism, while Lorentz violation arises from a background tensor coupled to the kinetic part of the Klein-Gordon Lagrangian. Two important quantities are calculated: the cross section for the scattering process and the modified Yukawa potential. The main results obtained in this work demonstrate that considering Lorentz symmetry breaking has several implications for changes in symmetries and physical states, while the presence of temperature is strongly related to the strength of the interaction. This interplay between symmetry breaking and temperature effects provides deeper insights into the behavior of the Yukawa theory under different conditions. Published by the American Physical Society 2024

The risk of increasing energy demand while pursuing decarbonisation: the case of the e-fuels for the EU aviation sector

The European Union target of a net-zero economy by mid-century requires an unprecedented effort in the reduction of carbon emissions. Aviation is among the most difficult sectors to decarbonize, and since direct electrification is unlikely to become a viable option in the short-term, other alternatives are considered, including biofuels and e-fuels. The blending mandates recently approved in the ReFuelEU Aviation package (35% of e-fuels at 2050) will require devoting an important amount of renewable electricity to produce e-fuels, increasing the relative weight of aviation with respect other sectors in terms of energy consumption. Aviation accounts today for 13% of the EU27 (2019) energy consumption for transport, while in 2050 this is expected to reach the 22%. This “magnifying effect” for the energy required by the sector, due to the low overall conversion efficiency of e-fuel production, will likely foster a competition for the access to renewable energy. This shift toward the aviation sector may occur to detriment of other applications potentially most effective in decreasing carbon emissions per unit of electricity. This apparent dichotomy between GHG reduction and energy efficiency could reduce the actual effectiveness of existing policies and the possibility of fostering similar initiatives in other countries.

Characterization of Bioactive Phenolic Compounds Extracted from Hydro-Distillation By-Products of Spanish Lamiaceae Plants.

Plants of the Lamiaceae family are widely used for the extraction of essential oils, and this industry generates a large number of solid residues as by-products, which contain non-volatile valuable compounds. The aim of this work was to identify and quantify the phenolic compounds present in these solid residues from different important Spanish species of Lamiaceae to characterize and valorize them. Forty-seven phenolic compounds were identified by HPLC-DAD-MS and quantified by HPLC-DAD. Different concentrations and types of phenolic compounds were found between the solid residues. The Rosmarinus officinalis extracts showed the highest total phenolic content due to their high phenolic terpene concentrations. The Thymus mastichina extracts were characterized by kaempferol and flavanones, and some flavones were derived from luteolin and apigenin. Finally, the sample Lavandula and Salvia lavandulifolia extracts presented the lowest content of most phenolic compounds, with the exception of some phenolic acids, such as danshensu, salvianolic acid A, and glucosides of hydroxycinnamic acids. Therefore, this work provides information on the quantification of a large number of phenolic compounds using a simple, sensitive, reproducible, and accurate methodology. In addition, the results indicate that these solid residues still contain important amounts of different polyphenols, which are antioxidants and can be used in different industries.

Improving CNN Fish Detection and Classification with Tracking

The regular and consistent monitoring of marine ecosystems and fish communities is becoming more and more crucial due to increasing human pressures. To this end, underwater camera technology has become a major tool to collect an important amount of marine data. As the size of the data collected outgrew the ability to process it, new means of automatic processing have been explored. Convolutional neural networks (CNNs) have been the most popular method for automatic underwater video analysis for the last few years. However, such algorithms are rather image-based and do not exploit the potential of video data. In this paper, we propose a method of coupling video tracking and CNN image analysis to perform a robust and accurate fish classification on deep sea videos and improve automatic classification accuracy. Our method fused CNNs and tracking methods, allowing us to detect 12% more individuals compared to CNN alone.

On delivering polar solvation free energy of proteins from energy minimized structures using a regularized super-Gaussian Poisson-Boltzmann model.

The biomolecules interact with their partners in an aqueous media; thus, their solvation energy is an important thermodynamics quantity. In previous works (J. Chem. Theory Comput. 14(2): 1020-1032), we demonstrated that the Poisson-Boltzmann (PB) approach reproduces solvation energy calculated via thermodynamic integration (TI) protocol if the structures of proteins are kept rigid. However, proteins are not rigid bodies and computing their solvation energy must account for their flexibility. Typically, in the framework of PB calculations, this is done by collecting snapshots from molecular dynamics (MD) simulations, computing their solvation energies, and averaging to obtain the ensemble-averaged solvation energy, which is computationally demanding. To reduce the computational cost, we have proposed Gaussian/super-Gaussian-based methods for the dielectric function that use the atomic packing to deliver smooth dielectric function for the entire computational space, the protein and water phase, which allows the ensemble-averaged solvation energy to be computed from a single structure. One of the technical difficulties associated with the smooth dielectric function presentation with respect to polar solvation energy is the absence of a dielectric border between the protein and water where induced charges should be positioned. This motivated the present work, where we report a super-Gaussian regularized Poisson-Boltzmann method and use it for computing the polar solvation energy from single energy minimized structures and assess its ability to reproduce the ensemble-averaged polar solvation on a dataset of 74 high-resolution monomeric proteins.

The Factors Influencing Import of Raw Crystal Sugar From Thailand to Indonesia

This research aims to determine what factors influence the import of raw crystal sugar from Thailand to Indonesia. The method for determining regions is purposively used, namely, in Indonesia. The data collection method used in this research is secondary data. The data analysis method used is a multiple linear regression test with the Ordinary Least Square or OLS method. The results of this research are as follows: (1) The regression model used passed the classical assumption test, namely Multicollinearity, Heteroscedasticity, Autocorrelation, and Normality. (2). Factors that have a significant positive effect on the quantity of imported raw crystal sugar (raw sugar) from Thailand to Indonesia are GDP (gross domestic product) per capita. In contrast, one factor that significantly affects the number of imports of raw crystal sugar (raw sugar) from Thailand to Indonesia is the price of imported sugar. (3). Factors that do not significantly influence the quantity of raw crystal sugar imports from Thailand to Indonesia are sugar import tariffs and consumption rates

Atomistic first-principles modeling of single donor spin-qubit

Using an impurity atom in crystal silicon as a spin-1/2 qubit has been made experimentally possible recently where the impurity atom acts as a quantum dot (QD). Quantum transport in and out of such a donor QD occurs in the sequential tunneling regime where a physical quantity of importance is the charging (addition) energy, which measures the energy necessary for adding an electron into the donor QD. In this work, we present a first-principles method to quantitatively predict the addition energy of the donor QD. Using density functional theory (DFT), we determine the impurity states that serve as the basis set for subsequent exact diagonalization calculation of the many-body states and energies of the donor QD. Due to the large effective Bohr radius of the conduction electrons in Si, very large supercells containing more than 10 000 atoms must be used to obtain accurate results. For the donor QD of a phosphorus impurity in bulk Si, the combined DFT and exact diagonalization predicts the first addition energy to be 53 meV, in good agreement with the corresponding experimental value. For the donor QD of an arsenic impurity in Si, the first addition energy is predicted to be 44.2 meV. The calculated many-body wave functions provide a vivid electronic picture of the donor QD.

Enhancing heat and mass transfer in MHD tetra hybrid nanofluid on solar collector plate through fractal operator analysis

Improved solar heat transfer methods are needed for the widespread use of solar energy. Due of their exceptional thermal characteristics, nanofluids have received a great deal of interest in this field. This research examines the use of tetra hybrid nanofluids in solar applications, with an emphasis on heat and mass transport properties. Due to their advantageous thermal characteristics, these nanofluids are well-suited for solar power production and other thermal applications. Accurate results for velocity, concentration, and temperature profiles are produced thanks to the model's use of fractal fractional derivatives and the Crank-Nicholson method for obtaining numerical solutions. In order to learn how different variables affect heat transport, parametric experiments are performed. The results show that tetra hybrid nanofluids greatly improve heat transfer performance over standard nanofluids. This improvement helps flat-plate solar collectors absorb more sunlight and increase their overall efficiency. The rate of mass transfer between phases may be quantified in the design and research of chemical reactors using the Sherwood number, an important quantity in chemical engineering. Its value is shown in a number of processes, including extraction, distillation, and catalytic reactions.

Non-equilibrium thermodynamics in NMR: understanding quadrupolar spin-1 systems.

In this study, we explore the non-equilibrium thermodynamics of a quantum system,
specifically focusing on spin-1 quadrupole nuclei. By employing fundamental principles
from quantum mechanics and statistical mechanics, we aim to understand the behavior
of the quadrupole spin-1 nuclei when subjected to external perturbations. Our analysis
involves the investigation of the system's dynamic response to non-equilibrium conditions through the manipulation of a work parameter. By treating work as a random
variable, we gather data from multiple cycles of finite duration, enabling us to compute
the complete distribution of the work generated during this process. Through these
finite-time non-equilibrium process data, we are able to determine equilibrium values
for important quantities such as the difference in free energy between the initial and
final states of the system. Additionally, we explore various properties of the system's
work distribution.

Managing phosphorus input pressures for improving water quality at the catchment scale

Phosphorus (P) pollution of freshwater is an endemic threat to water quality and aquatic biodiversity. To better define the contributions of the two main food system sectors (agriculture and wastewater) responsible for freshwater P pollution, we investigated how the magnitude and distribution of sector P input pressures calculated using Substance Flow Analysis (SFA) linked to the P pollution threat across four distinct physiographic regions of the River Stour catchment (1260 km2) in Dorset, England. Agricultural P input pressures (−1 to 7 kg ha−1 yr−1) were dependent on the amount of livestock feed imports and resulting manure loadings to land, whilst food imports and population densities were the main driver of the human net P inputs of up to 13 kg ha−1 yr−1. Total P input pressures (i.e. Net Anthropogenic P Inputs (NAPI)) were positively correlated (r2 0.8–0.9) to riverine P flux of up to 6 kg ha−1 yr−1 across the catchment. Using measured river P concentration (C) and flow discharge (Q) analysis to distinguish monitoring stations capturing mainly diffuse P sources (termed diffuse stations), estimated riverine P fluxes attributable to agriculture varied up to 0.92 kg ha−1 yr−1 depending on the surplus P inputs applied to land. A combination of enhanced wastewater P removal and reduced surplus agricultural P inputs was required to improve water quality. For example, the P pressure-river P flux relationship at diffuse stations suggested that in the catchment area dominated by livestock production, removing the agricultural P surplus of 7 kg ha−1 yr−1 would reduce annual average river SRP concentrations in this area by a third to 0.23 mg L−1, but still well above the target concentration for eutrophication control (0.08 mg L−1). Our approach of linking SFA outputs to measured river P data provides a potential complimentary and internationally relevant methodology to evidence effective sector mitigation targets and policies in catchments, and its further testing in other catchments is recommended.

Revision of Sabine's and Eyring's reverberation theories

Sabine's and Eyring's reverberation theories are still the most important theoretical frameworks for room acoustics. The important physical quantities derived from these theories are the average sound pressure level (sound energy density) and the reverberation time (sound energy decay). Eyring revised Sabine's theory to become the reverberation time zero in the perfect absorption condition. However, Eyring's theory has contradictions regarding the sound energy density in a steady state and the energy decay from the steady state. In this study, in order to resolve these contradictions, the theoretical framework for the consistent system is presented introducing the new concept of the average impulse response in a room, and the contradictions in the current room acoustic theory are clarified. Based on the theoretical framework, Sabine's reverberation theory is revised by a different way of Eyring's theory. The reverberation time of the revised theory is shorter than that of Sabine's theory and longer than that of Eyring's theory. Finally, ray-tracing computer simulations were performed to verify the revised theory. Results of sound ray tracing simulations were in better agreement with the values calculated using the revised theory rather than those calculated using Sabine's and Eyring's theories.

Kinetic energy and speed powers vn of a heavy quark inside S wave and P wave heavy-light mesons

The average values of the powers of |q→|n¯≡qn and |v→|n¯≡vn are commonly used physical quantities, where q→ and v→ are the three-dimensional momentum and velocity of a quark inside a meson, respectively. For example, the average kinetic energy μπ2=q2 is an important quantity in the heavy quark effective theory, and the expansion of vn is commonly used in the nonrelativistic quantum chromodynamics. In this paper, based on the instantaneous Bethe-Salpeter equation method, we calculate the average values qn and vn (n=1, 2, 3, 4) of a heavy quark inside S wave and P wave heavy-light mesons. We obtain the kinetic energy μπ2=0.455 GeV2 for the B meson, which is consistent with the experimental result 0.464±0.076 GeV2. For the Bs, D, and Ds mesons, the μπ2 are 0.530, 0.317, and 0.369 GeV2, respectively, and v2=0.0185, 0.0215, 0.121, and 0.140 for B, Bs, D, and Ds, respectively. We obtain some relationships, for example, q0−n(mS)≈q1−n(mS), q0+n(mP)≈q1+′n(mP′)>q1+n(mP)≈q2+n(mP), and qn(mS)<qn(mP) (m=1, 2, 3), etc. Published by the American Physical Society 2024

Charting the Lyman-α escape fraction in the range 2.9 < z < 6.7 and consequences for the LAE reionisation contribution

Context. The escape of Lyman-α photons at redshifts greater than two is an ongoing subject of study and an important quantity to further understanding of Lyman-α emitters (LAEs), the transmission of Lyman-α photons through the interstellar medium and intergalactic medium, and the impact these LAEs have on cosmic reionisation. Aims. This study aims to assess the Lyman-α escape fraction, fesc, Lyα, over the redshift range 2.9 < z < 6.7, focusing on Very Large Telescope/Multi Unit Spectroscopic Explorer (VLT/MUSE) selected, gravitationally lensed, intrinsically faint LAEs. These galaxies are of particular interest as the potential drivers of cosmic reionisation. Methods. We assessed fesc, Lyα in two ways: through an individual study of 96 LAEs behind the A2744 lensing cluster, with James Webb Space Telescope/Near-Infrared Camera (JWST/NIRCam) and HST data, and through a study of the global evolution of fesc, Lyα using the state-of-the-art luminosity functions for LAEs and the UV-selected ‘parent’ population (dust-corrected). We compared these studies to those in the literature based on brighter samples. Results. We find a negligible redshift evolution of fesc, Lyα for our individual galaxies; it is likely that it was washed out by significant intrinsic scatter. We observed a more significant evolution towards higher escape fractions with decreasing UV magnitude and fit this relation. When comparing the two luminosity functions to derive fesc, Lyα in a global sense, we saw agreement with previous literature when integrating the luminosity functions to a bright limit. However, when integrating using a faint limit equivalent to the observational limits of our samples, we observed enhanced values of fesc, Lyα, particularly around z ∼ 6, where fesc, Lyα becomes consistent with 100% escape. This indicates for the faint regimes we sampled that galaxies towards reionisation tend to allow very large fractions of Lyman-α photons to escape. We interpret this as evidence of a lack of any significant dust in these populations; our sample is likely dominated by young, highly star-forming chemically unevolved galaxies. Finally, we assessed the contribution of the LAE population to reionisation using our latest values for fesc, Lyα and the LAE luminosity density. The dependence on the escape fraction of Lyman continuum photons is strong, but for values similar to those observed recently in z ∼ 3 LAEs and high-redshift analogues, LAEs could provide all the ionising emissivity necessary for reionisation.

Uses of plasma in medicine

Plasma is the liquid portion of whole blood, It is composed largely of water and proteins, and it provides a medium for red blood cells, white blood cells and platelets to circulate through the body. The plasma contains an important amount of antibiotics capable of strengthening the patient's immunity in the face of the threat of the virus. When plasma is injected into the scalp, it renews cells and stimulates the production of collagen and protein, two substances that make up the second middle layer of the skin, which give the skin freshness and vitality. One of the most important benefits of plasma for the face is that it uses platelets to inject the face and it plays several roles inside the skin once it is injected under it. Plasma can be used as a local injection as well to treat tissue ruptures such as knee ligament tears. platelet-rich plasma (PRP) can improve wound-healing processes in orthopedic surgery, dermatology, ophthalmology, gynecology and plastic surger.

Dissipation of AGN Jets in a Clumpy Interstellar Medium

Accreting supermassive black holes frequently power jets that interact with the interstellar medium (ISM)/circumgalactic medium, regulating star formation in the galaxy. Highly supersonic jets launched by active galactic nuclei (AGN) power a cocoon that confines them and shocks the ambient medium. We build on the models of narrow conical jets interacting with a smooth ambient medium, including the effect of dense clouds, which are an essential ingredient of a multiphase ISM. The key physical ingredient of this model is that the clouds along the supersonic jet beam strongly decelerate the jet head but the subsonic cocoon easily moves around the clouds without much resistance. We propose scalings for important physical quantities—cocoon pressure, head and cocoon speed, and jet radius. For the first time, we obtain the analytic condition on the ambient medium’s clumpiness for the jet to dissipate within the cocoon and verify it with numerical simulations of conical jets interacting with a uniform ISM with embedded spherical clouds. A jet is defined to be dissipated when the cocoon speed exceeds the speed of the jet head. We compare our models with more sophisticated numerical simulations and direct observations of jet–ISM interaction (e.g., quasar J1316+1753), and we discuss implications for the Fermi/eROSITA bubbles. Our work also motivates effective subgrid models for AGN jet feedback in a clumpy ISM unresolved by the present generation of cosmological galaxy formation simulations.

Quantum Tunneling: From Theory to Error‐Mitigated Quantum Simulation

AbstractEver since the discussions about a possible quantum computer arised, quantum simulations have been at the forefront of possible utilities, with the task of quantum simulations being one that promises quantum advantage. Recently, advancements have made it feasible to simulate complex molecules using Variational Quantum Eigensolvers or study the dynamics of many‐body spin Hamiltonians. These simulations have the potential to yield valuable outcomes through the application of error mitigation techniques. Simulating smaller models carries a great amount of importance as well and currently, in the Noisy Intermediate Scale Quantum era, is more feasible since it is less prone to errors. The objective of this work is to examine the theoretical background and the circuit implementation of a quantum tunneling simulation, with an emphasis on hardware considerations. This study presents the theoretical background required for such implementation and highlights the main stages of its development. By building on classic approaches of quantum tunneling simulations, this study aims at improving the result of such simulations by employing error mitigation techniques, Zero Noise Extrapolation, and Readout Error Mitigation and uses them in conjunction with multiprogramming of the quantum chip, a technique used for solving the hardware under‐utilization problem that arises in such contexts.

New capabilities of application of gamma-ray logging in borehole geophysical investigations through steel string

Borehole geophysical investigations through steel string (both drill and casing) are becoming increasingly important. Gamma-ray logging (GR) is a mandatory and one of the main methods for investigating oil-and-gas reservoirs and near-surface rocks. It is characterized by high efficiency under the aforementioned measurement conditions. GR is used to identify bed boundaries, evaluate lithology, estimate shaliness, identify reservoirs, etc. Traditionally, the determination of granu- lometric shaliness is the main goal of quantitative interpretation for GR. Gamma-ray logging has been successfully used for many decades. However, increasing the accuracy of determining granulometric shaliness, expanding the informativeness of the method to determine mineral clayness, and developing procedures for using GR data in estimating other petrophysical parameters are topical issues. Based on logging materials, the paper examines the features of using the main interpretation parameter of GR (the relative difference parameter – index ΔІγ) in boreholes in the presence of a steel column and proposes new methodological approaches to the use of GR data when interpreting measurements in oil-and-gas and engineering-geological boreholes. Through numerous ex- amples, the invariance (constancy) of the interpretation parameter of gamma-ray logging has been proven under different borehole conditions, types of logging tools, etc. An approach has been proposed for obtaining optimal reference values when determining this parameter, which increases the accuracy of estimating shaliness parameters. A method has been developed for determining mineral clayness, which is an important quantity in itself and is necessary for determining other petrophysical parameters from loggingdata. A multiplicative method has been created for determining the total porosity of shaly rocks using a combination of neutron logging and gamma-ray logging, which makes it possible to avoid using the hydrogen index of clay minerals. The novelty of the developments is supported by patents, and their effectiveness is confirmed by the results of borehole tests and comparisons with independent determinations of parameters (laboratory core studies, traditional methods of interpretation). The proposed approaches are an important component of the investigation technologies for oil-and-gas reservoirs and near-surface rocks, developed at the Institute of Geophysics of the National Academy of Sciences of Ukraine.