Important Quantities Research Articles

Properties of radiation defects and threshold energy of displacement in zirconium hydride obtained by new deep-learning potential

Abstract Zirconium hydride (ZrH2) is an ideal neutron moderator material. However, radiation effect significantly changes its properties, which affect its behavior and the lifespan of the reactor. The threshold energy of displacement is an important quantity of the number of radiation defects produced, which helps us to predict the evolution of radiation defects in ZrH2. Molecular dynamics (MD) and ab initio molecular dynamics (AIMD) are two main methods of calculating the threshold energy of displacement. The MD simulations with empirical potentials often cannot accurately depict the transitional states that lattice atoms must surpass to reach an interstitial state. Additionally, the AIMD method is unable to perform large-scale calculation, which poses a computational challenge beyond the simulation range of density functional theory. Machine learning potentials are renowned for their high accuracy and efficiency, making them an increasingly preferred choice for molecular dynamics simulations. In this work, we develop an accurate potential energy model for the ZrH2 system by using the deep-potential (DP) method. The DP model has a high degree of agreement with first-principles calculations for the typical defect energy and mechanical properties of the ZrH2 system, including the basic bulk properties, formation energy of point defects, as well as diffusion behavior of hydrogen and zirconium. By integrating the DP model with Ziegler–Biersack–Littmark (ZBL) potential, we can predict the threshold energy of displacement of zirconium and hydrogen in ε-ZrH2.

Using the Tidal Response of Groundwater to Assess and Monitor Caprock Confinement in CO2 Geological Sequestration

Carbon geological storage (CGS) is an important global practice implemented to mitigate the effects of CO2 emissions on temperature, climate, sea level, and biodiversity. The monitoring of CGS leakage and the impact of storage on hydrogeological properties is important for management and long-term planning. In this study, we show the value of passive monitoring methods based on measuring and modeling water-level responses to tides. We review how monitoring can be used to identify time-varying horizontal and vertical permeabilities as well as independently detect time-varying fracture distribution in aquifer–caprock systems. Methods based on water-level responses to Earth tides are minimally invasive, convenient, economic (since they use existing groundwater wells), and time-continuous. We show how measurements can be used to detect aquifer leakage (caprock confinement) and the distribution of surrounding faults and fractures, which are the two most important unsolved quantities in assessing geological CO2 storage strategies.

Virtual point tracking method for online detection of relative wheel-rail displacement of railway vehicles

Relative wheel-rail displacement (RWRD) is an important physical quantity that responds to the hunting stability and running safety of railway vehicles but detecting this physical quantity is challenging during train operation due to the complex service environment and the nonlinearity of vehicle-rail system. To address this problem, this paper proposes a virtual point tracking (VPT) method to detect RWRD. First, a series of regions of interest (ROIs) in the preprocessed wheel-rail contact images are extracted using a simplified YOLO (SYOLO) model. Then, some key positions of the wheel and rail on the extracted ROIs are identified using an improved UNet (IUNet) model and characterized by virtual points. Finally, the global coordinates of the virtual points in the whole wheel-rail contact image are calculated to obtain the final RWRD. To demonstrate the feasibility of the VPT method, it is used to detect the RWRD of a vehicle operating on a full-scale roller rig. For comparison, the original UNet model is directly used to detect the RWRD. Two quantities, Mean Absolute Error (MAE) and Root Mean Square Error (RMSE), are applied for quantitative analysis and the results show that the VPT method can identify the RWRD more reliably and accurately.

Weak Coupling Regime in Dilatonic f(R,T) Cosmology

We consider f(R,T) modified theories of gravity in the context of string-theory-inspired dilaton gravity. We deal with a specific model that under certain conditions describes the late time Universe in accord with observational data in modern cosmology and addresses the H0 tension. This is done by exploring the space of parameters made out of those coming from the modified gravity and dilatonic charge sectors. We employ numerical methods to obtain several important observable quantities.

Modeling and analysis of hybrid-blood nanofluid flow in stenotic artery

Current communication deals with the flow impact of blood inside cosine shape stenotic artery. The under consideration blood flow is treated as Newtonian fluid and flow is assumed to be two dimensional. The governing equation are modelled and solved by adopting similarity transformation under the stenosis assumptions. The important quantities like Prandtl number, flow parameter, blood flow rate and skin friction are attained to analyze the blood flow phenomena in stenosis. The variations of different parameters have been shown graphically. It is of interest to note that velocity increases due to change in flow parameter gamma and temperature of blood decreases by increasing nanoparticles volume fraction and Prandtl number. In the area of medicine, the most interesting nanotechnology approach is the nanoparticles applications in chemotherapy. This study provides further motivation to include more convincing consequences in the present model to represent the blood rheology.

Construction of relatedness matrices in autopolyploid populations using low-depth high-throughput sequencing data

Key messageAn improved estimator of genomic relatedness using low-depth high-throughput sequencing data for autopolyploids is developed. Its outputs strongly correlate with SNP array-based estimates and are available in the package GUSrelate.High-throughput sequencing (HTS) methods have reduced sequencing costs and resources compared to array-based tools, facilitating the investigation of many non-model polyploid species. One important quantity that can be computed from HTS data is the genetic relatedness between all individuals in a population. However, HTS data are often messy, with multiple sources of errors (i.e. sequencing errors or missing parental alleles) which, if not accounted for, can lead to bias in genomic relatedness estimates. We derive a new estimator for constructing a genomic relationship matrix (GRM) from HTS data for autopolyploid species that accounts for errors associated with low sequencing depths, implemented in the R package GUSrelate. Simulations revealed that GUSrelate performed similarly to existing GRM methods at high depth but reduced bias in self-relatedness estimates when the sequencing depth was low. Using a panel consisting of 351 tetraploid potato genotypes, we found that GUSrelate produced GRMs from genotyping-by-sequencing (GBS) data that were highly correlated with a GRM computed from SNP array data, and less biased than existing methods when benchmarking against the array-based GRM estimates. GUSrelate provides researchers with a tool to reliably construct GRMs from low-depth HTS data.

Impact of Deficit Irrigation Strategies Using Saline Water on Soil and Peach Tree Yield in an Arid Region of Tunisia

Sustainable fruit orchard development in arid areas is severely affected by the scarcity of fresh water. To mitigate the lack of fresh water, the use of low-quality water for irrigation is becoming a common practice in several margin areas. However, salinity is considered one of the most important environmental constraints limiting the successful crop production. Therefore, the effects of deficit irrigation strategies using saline water (3.1 dS m−1) on soil water content, soil salinity, and yield of commercial peach orchard were investigated. Three irrigation treatments were considered: a Control, full irrigated (FI); and partial root-zone drying (PRD50); and deficit irrigation (DI) strategies irrigated at 50% ETc. These levels of water supply allowed for contrasting watering conditions with clear distinction between irrigation treatments. The differential pattern in soil moisture was accompanied by that of soil salinity with an increase in all FI treatments (16–25%). The results indicated that soil salinity increased with increasing water supply and evaporative demand during the growing season from January (3.2 dS m−1) to August (6.6 dS m−1). Deficit irrigation strategies (DI, PRD50) induced more soil salinity along the row emitter compared to the Control due to insufficient leaching fractions. By the end of the growing season, the soil salinity under long-term saline drip irrigation remained stable (5.3–5.7 dS m−1). An efficient leaching action seemed to be guaranteed by rainfall and facilitated by sandy soil texture, as well as the high evaporative demand and the important salt quantity supplied, which maintain the deficit irrigation strategies as valuable tools for water saving and improving water productivity. The significant water saving of 50% of water requirements induced a fruit yield loss of 20%. For this reason, DI and PRD50 could be reasonable irrigation management tools for saving water and controlling soil salinity in arid areas and on deep sandy soil.

Research on the Impact of China's Import and Export Trade on Carbon Emission under the Perspective of Carbon Emission Reduction ——Empirical Evidence Based on Provincial Panel Data

With the development of economic globalization, China's import and export trade with other countries around the world has become increasingly frequent. However, the huge energy gap has led to serious environmental pollution problems in China, and how to realize sustainable development has become an important issue. Therefore, based on the research of scholars at home and abroad, this paper utilizes the panel data of 30 provinces and cities from 2012 to 2021 as well as the method of multiple stepwise regression to study the influencing factors of carbon emissions in China. The results show that China has achieved some success in improving the level of regional economic development, transitioning from traditional finance to green finance, and improving the level of scientific and technological development, which can effectively curb the growth of carbon emissions; however, the total amount of import and export trade, the level of advanced industrial structure, and the energy structure are still the key factors hindering the cause of carbon emission reduction.

Physico-chemical properties of macadamia nut shell post-gasification residues and potential agricultural application

In–depth information about the characteristics and potential use of post-gasification residues is the key to unlock the sustainability potential of biomass gasification. This study aimed to explicate the physico-chemical properties of residues after the gasification of macadamia nut shell using a commercial gasifier. The results revealed an important amount of carbon content remained in the residues, marking the low conversion efficiency of the process. The obtained residues were deemed unsuitable for use as adsorbents due to low surface areas with non-porous structures. However, the surface of the residues contained multiple carboxyl and hydroxyl functional groups. Also, a remarkable amount of K (up to 86 wt% of the char’s total inorganic elements) was observed to be evenly distributed on the char surface. The results solidified the possibility of utilizing the residues as bio-fertilizers, and provided essential data for the development of sustainable energy production processes using macadamia nut shell for gasification.

Quality parameters and lipid composition of oil extracted from spent coffee grounds: A promising alternative to vegetable oils used for consumption and cosmetic purposes

AbstractCoffee grounds are the most commonly generated daily waste in the world, raising numerous questions regarding their proper management and their environmental impact. The present study focuses on the physical and chemical characterization of oil extracted from spent coffee grounds (SCG), with the aim of valorizing this by‐product as a potential source for oil production. The results obtained from the analysis of SCG oil were also compared to those of some edible oils (soybean, corn, and sunflower oils) and cosmetic oils (lentisc, sweet almond, and castor oils). The results revealed that spent coffee waste yielded an important amount of oil, specifically 17.19%, as compared to corn (4.31%) and soybean (19.52%) seeds. Regarding the fatty acids composition of SCG oil, eight components were identified, with a high percentage of polyunsaturated fatty acids accounting for more than 45% of total fatty acids. The phytosterols composition of SCG oil revealed the presence of seven components, with β‐sitosterol being the predominant one. The tocopherol analysis showed that SCG oil contained only α and β isomers, with β‐tocopherol being the dominant form at over 68%. These findings accentuate the potential of spent coffee waste as a promising alternative for oil production and open up new applications for SCG oil, such as in the food industry, pharmaceutical applications, and cosmetics.Practical Application: Given the significant increase in the demand for vegetable oils, the oil industry has recently begun to explore new plant matrices, particularly those having low costs. SCG are the most commonly generated daily by‐product in the world. The present investigation aims to characterize and valorize the oil extracted from SCG. The obtained results revealed the potential of SCG as a promising alternative for oil production. Consequently, valorizing spent coffee waste as a natural by‐product for oil production can be an ideal solution to address numerous issues related to its proper management and its environmental impact. Hence, the oil industry can promote spent coffee waste, cheapest by‐products, as a promising alternative for oil production. Moreover, the present investigation represents a commendable model of the circular economy since the remaining waste obtained after extracting lipids from the coffee grounds waste can be used as natural fertilizer rich in protein for plant development.

A Monte Carlo Sensitivity Analysis for a Dimensionally Reduced-Order Model of the Aortic Dissection.

Aortic dissection is associated with a high mortality rate. Although computational approaches have shed light on many aspects of the disease, a sensitivity analysis is required to determine the significance of different factors. Because of its complex geometry and high computational expense, the three-dimensional (3D) fluid-structure interaction (FSI) simulation is not a suitable approach for sensitivity analysis. We performed a Monte Carlo simulation (MCS) to investigate the sensitivity of hemodynamic quantities to the lumped parameters of our zero-dimensional (0D) model with numerically calculated lumped parameters. We performed local and global analyses on the effect of the model parameters on important hemodynamic quantities. The MCS showed that a larger lumped resistance value for the false lumen and the tears result in a higher retrograde flow rate in the false lumen (the coefficient of variation, , the sensitivity , Spearman's coefficient, ). For the intraluminal pressure, our results show a significant role in the resistance and inertance of the true lumen (the coefficient of variation, , the sensitivity , and Spearman's coefficient, for the inertance of the true lumen). This study highlights the necessity of comparing the results of the local and global sensitivity analyses to understand the significance of multiple lumped parameters. Because of the efficiency of the method, our approach is potentially useful to investigate and analyze medical planning.

Dissecting the genetic architecture of quantitative traits using genome-wide identity-by-descent sharing.

Additive and dominance genetic variances underlying the expression of quantitative traits are important quantities for predicting short-term responses to selection, but they are notoriously challenging to estimate in most non-model wild populations. Specifically, large-sized or panmictic populations may be characterized by low variance in genetic relatedness among individuals which, in turn, can prevent accurate estimation of quantitative genetic parameters. We used estimates of genome-wide identity-by-descent (IBD) sharing from autosomal SNP loci to estimate quantitative genetic parameters for ecologically important traits in nine-spined sticklebacks (Pungitius pungitius) from a large, outbred population. Using empirical and simulated datasets, with varying sample sizes and pedigree complexity, we assessed the performance of different crossing schemes in estimating additive genetic variance and heritability for all traits. We found that low variance in relatedness characteristic of wild outbred populations with high migration rate can impair the estimation of quantitative genetic parameters and bias heritability estimates downwards. On the other hand, the use of a half-sib/full-sib design allowed precise estimation of genetic variance components and revealed significant additive variance and heritability for all measured traits, with negligible dominance contributions. Genome-partitioning and QTL mapping analyses revealed that most traits had a polygenic basis and were controlled by genes at multiple chromosomes. Furthermore, different QTL contributed to variation in the same traits in different populations suggesting heterogeneous underpinnings of parallel evolution at the phenotypic level. Our results provide important guidelines for future studies aimed at estimating adaptive potential in the wild, particularly for those conducted in outbred large-sized populations.

Measuring spectral extinction with digital holography.

The optical extinction caused by a small particle, such as an aerosol particle, is an important measurable quantity. Understanding the influence of atmospheric aerosols on the climate, assessing visibility in urban environments, and remote sensing applications such as lidar all need accurate measurements of particle extinction. While multiple methods are known to measure extinction, digital in-line holography (DIH) features the unique ability to provide contact-free images of particles simultaneously with estimates for the extinction cross section. This is achieved through an integration of a measured hologram followed by an extrapolation. By means of a supercontinuum laser, we investigate the measurement of the cross section via DIH for stationary particles across a broad spectrum, from 440nm to 1040nm. The particles considered include a 50µm glass microsphere, a volcanic ash particle, and an iron(III) oxide particle. The results show the ability to estimate a particle's cross section to within 10% error across portions of the spectrum and approximately 20% error otherwise. An examination of the accompanying hologram-derived particle images reveals details in the images that evolve with wavelength. The behavior suggests a basic means to resolve whether absorption or scattering dominates a particle's extinction.

Current perspectives and challenges in the estimation of fruit juice consumption across the lifecycle in Europe.

Fruit juice (FJ) is typically low in energy, contains natural sugars, important amounts of micronutrients and is not permitted to have added sugars/sweeteners. However, its role in a healthy diet is under scrutiny partly due to the wider adoption of the definition for free sugars in nutrition policy. This review aimed to identify data on FJ consumption from national food consumption surveys across Europe, to examine current intakes, percent consumers and its contribution to intakes of energy, total sugars, free sugars, vitamin C, folate and potassium. Data were extracted on the population mean intake of FJ and its contribution to nutrient intakes across the lifecycle and crude estimates of population mean intakes across countries were reported for the total population and for consumers only. This review highlighted significant gaps/challenges regarding the availability of country-specific national food consumption surveys across Europe and specifically data on FJ consumption (including complexities surrounding categorisations). Nonetheless, using a comparable/homogenous definition, the mean intake of FJ among consumers was approximately 1 × 150 ml glass/day for adults/older adults, with lower intakes among infants (86 g/d), children (108 g/d) and teenagers (112 g/d). FJ made important contributions to intakes of vitamin C while making little contribution to energy intakes but also contributed 2-14 % of free sugars intake (which may be considered modest compared to other sources). The complexity of collating and interpreting data on FJ intake as elucidated in this review raises questions surrounding the categorisation of FJ in research and presents significant challenges for policymakers with respect to dietary guidance for FJ.

Size-dependence of fracture processes in intact rocks

In brittle heterogeneous materials, the ultimate stress carries information on the material’s load-bearing capacity and, for this reason, this stress is an important engineering quantity. However, this stress is just a point in the sequence of stress–strain responses, each of them reflects the current state of damage in the material. Initially, isolated cracks grow, sense each other, and form multiple crack networks. The networks enable dilatational shear and facilitate further growth of damage. Large samples contain a broad spectrum of the crack-enabling defects and, therefore, the sample size becomes an irrelevant factor. However, when the defect population is limited, the damage process is constrained and, as a result, the peak stress is rising. According to the central limit theorem, the defect’s propensity for generating cracks should obey the rules of normal distribution. It turns out that the normal distribution of defects becomes a Weibull-like distribution of strength, where shape of the distribution is affected by the sample size and, also, is sensitive to hydrostatic pressure. The size-dependence of fracture processes is the main objective of the study.

On variability and detecting unreliable measurements in animal cystometry

IntroductionAnimal cystometry, a process of infusing fluid into the urinary bladder to evoke reflex contractions, is a common way to study the effects of pathology, injury, or experimental therapy on lower urinary tract (LUT) dynamics. By monitoring fluid movement during the cystometric micturition cycle, one can compute important quantities that indicate the health and function of the LUT, such as bladder capacity and voiding efficiency. Unfortunately, volume measurements in these difficult studies are often unpreventably corrupted by noise, leading to uncertainty when estimating key cystometric parameters.MethodsThis work proposes a criterion, based on measurable quantities, that flags micturition cycles in cystometry studies that are likely to contain large measurement errors, potentially allowing experimenters to remove them from analysis to obtain a more accurate summary of LUT dynamics.ResultsWe describe the criterion, validate it against experimental data, and use computer simulations to demonstrate its utility.

Electron interaction with DNA constituents in aqueous phase.

Electron driven chemistry of biomolecules in aqueous phase presents the realistic picture to study molecular processes. In this study we have investigated the interactions of electrons with the DNA constituents in their aqueous phase in order to obtain the quantities useful for DNA damage assessment. We have computed the inelastic mean free path (IMFP), mass stopping power (MSP) and absorbed dose (D) for the DNA constituents (Adenine, Cytosine, Guanine, Thymine and Uracil) in the aqueous medium from ionisation threshold to 5000 eV. We have modified complex optical potential formalism to include band gap of the systems to calculate inelastic cross sections which are used to estimate these entities. This is the maiden attempt to report these important quantities for the aqueous DNA constituents. We have compared our results with available data in gas and other phase and have observed explicable accord for IMFP and MSP. Since these are the first results of absorbed dose (D) for these compounds, we have explored present results vis-a-vis dose absorption in water.

Simple Estimation of the Trapping Height in Optical Tweezers

The trapping height is an important quantity that influences the parameters measured by optical tweezers such as the stiffness, the force and stability of the trap. In this paper, we propose a simple method using video microscopy and based on tracking of particles positions in the axial and radial directions. The positional fluctuations in the axial direction were used to estimate the trap height and determine the trap stiffness using Boltzmann statistics. This method makes it possible to obtain simultaneously the trap stiffness and the trap height. The entropy values of the information for each image allowed us to validate this method because of the relation which exists between it and the axial displacements. Note that this method is simple and quick to determine the height of the trap if it has not been estimated at the start or during the measurement.

On the significance of aspartate aminotransferase and creatine kinase in wild reptile health studies.

In reptile medicine, the enzymes aspartate aminotransferase (AST) and creatine kinase (CK) have been used in clinical diagnostics, where CK is considered an enzyme specific to muscle cell damage, while AST is a nonspecific enzyme that is mainly produced in the liver and muscle. When many native reptiles are sampled, it is evident that there are important differences between species and individuals belonging to the same species, making the AST and CK ranges very wide. The minimum and maximum values, variations and standard deviations were extracted for each enzyme from 17 wild reptile studies, revealing high variation and a wide range of variation for each species. AST and CK must be interpreted with caution in wild reptiles since there appears to be an important amount of individual and specific variation due to the muscular origin of these enzymes, and such variations tell us that there are considerable differences between individuals, physiological characteristics or sampling methods; thus, there is no apparent value derived from these kinds of studies on the utility of AST for evaluating liver damage, but the measurement of AST and CK can be useful for reptile health assessments or any manipulative study since they can eventually be used as indicators or potential biomarkers for restraint techniques or holding time.

Estimating the turbulent kinetic energy dissipation rate from one-dimensional velocity measurements in time

Abstract. The turbulent kinetic energy dissipation rate is one of the most important quantities characterizing turbulence. Experimental studies of a turbulent flow in terms of the energy dissipation rate often rely on one-dimensional measurements of the flow velocity fluctuations in time. In this work, we first use direct numerical simulation of stationary homogeneous isotropic turbulence at Taylor-scale Reynolds numbers 74≤Rλ≤321 to evaluate different methods for inferring the energy dissipation rate from one-dimensional velocity time records. We systematically investigate the influence of the finite turbulence intensity and the misalignment between the mean flow direction and the measurement probe, and we derive analytical expressions for the errors associated with these parameters. We further investigate how statistical averaging for different time windows affects the results as a function of Rλ. The results are then combined with Max Planck Variable Density Turbulence Tunnel hot-wire measurements at 147≤Rλ≤5864 to investigate flow conditions similar to those in the atmospheric boundary layer. Finally, practical guidelines for estimating the energy dissipation rate from one-dimensional atmospheric velocity records are given.