Rn Values Research Articles

Tuning the IcRn value of YBCO step edge Josephson junction through Ar+ ion irradiation

YBCO Step edge Josephson junctions are fabricated on single crystal MgO (100) substrates, and the effect of Ar+ ion irradiation on the critical current (Ic) and normal state resistance (Rn) is studied. It is shown that on the appropriate exposure of the YBCO step edge junction to Ar+ ion irradiation, the IcRn product of the junction can be enhanced up to 0.66 mV at 77 K, which is sufficiently good for many applications. With the increase in the exposure time of Ar+ ion irradiation, the value of Ic decreases, and the Rn value increases. After irradiating for 4 min, Ic as low as 70 μA and Rn as high as ∼9.4 Ω have been obtained at 77 K. It is found that for higher exposure time, the junction behavior tends to SIS-type junctions. The mechanism responsible for the decrease in Ic and increase in Rn seems to be associated with the vacancies as well as displacement of oxygen atoms caused by the ion irradiation, which causes the suppression of superconducting parameters as the superconducting properties critically depend on the concentration of the oxygen atoms in the Cu-O planes.

Monitoring anomalies on large-scale energy and water balance components by coupling remote sensing parameters and gridded weather data.

The SAFER (Simple Algorithm for Evapotranspiration Retrieving) algorithm was applied with MODIS images and gridded weather data from 2007 to 2021, to monitor the energy balance components and their anomalies, in the Atlantic Forest (AF) and Caatinga (CT) biomes inside the coastal agricultural growing zone, Northeast Brazil. Considering the long-term data, the Rn values between the biomes are not significantly different, however presenting distinct Rn partitions into latent (λE), sensible (H), and ground (G) heat fluxes between biomes. The Rn values annual averages are 9.40 ± 0.21 and 9.50 ± 0.23MJm-2 d-1, for AF and CT, respectively. However, for respectively AF and CT, they are respectively 5.10 ± 1.14MJm-2 d-1 and 4.00 ± 0.99MJm-2 d-1 for λE; 3.80 ± 1.12MJm-2 d-1 and 5.00 ± 1.00MJm-2 d-1 for H; 0.50 ± 0.12MJm-2 d-1 and 0.40 ± 0.10MJm-2 d-1 for G, yielding respective mean evaporative fraction (Ef = λE/(Rn - G) values of 0.60 ± 0.12 and 0.50 ± 0.15. Anomalies on λE, H, and Ef were detected through standardized index for these energy balance components by comparing the results for the years 2018 to 2021 with the long-term values from 2007 to each of these years, showing that the energy fluxes between surfaces and the lower atmosphere, and then the root-zone moisture conditions for both biomes, may strongly vary along seasons and years, with alternate positive and negative anomalies. These assessments are important for water policies as they can picture suitable periods and places for rainfed agriculture as well as the irrigation needs in irrigated agriculture, allowing rational agricultural environmental management while minimizing water competitions among other water users, under climate and land-use changes conditions.

Effect of Macro Fibers on the Permeability and Crack Surface Topography of Layered Fiber Reinforced Concrete.

This paper describes the effects of macro fibers on permeability and crack surface topography of layered fiber-reinforced concrete (FRC) specimens with different layering ratios under uniaxial tensile load. The crack permeability of layered FRC specimens is investigated by a self-designed permeability setup. The topographical analysis of crack surfaces is investigated by a custom-designed laser scanning setup. The results show that when the fiber volume content and layering ratio of the FRC layer are constant, the tensile toughness of layered FRC specimens depends on the proportion of steel fiber in macro fibers, and with an increase in the proportion of steel fiber, the tensile toughness of layered FRC specimens increases. For the layered FRC specimens, the crack permeability is much lower than that of the normal concrete (NC) specimen. A significant positive synergistic effect on crack impermeability can be achieved by the combination of steel fiber and polypropylene fiber in the SF80PP2.3 specimen. The crack surface roughness parameter (Rn) values of the NC layer in layered FRC specimens are all higher than those of the NC specimen, and the crack surface Rn of the FRC layer in layered FRC specimens is higher than that of the unlayered FRC specimens. This can effectively increase the head loss of cracks and reduce the crack permeability of layered FRC specimens.

Effect of nitrogen/argon ratios on structures and properties of high-entropy (ZrTiNbV)N nitride films by multi-arc ion plating

The multi-arc ion plating technique has been used to prepare high-entropy (ZrTiNbV)N ceramic films. Meanwhile, the effects of different nitrogen/argon ratios of RN on film microstructures, mechanical properties, tribological properties and corrosion resistance are systematically investigated. The high-entropy (ZrTiNbV)N ceramic films with face-centered cubic structure are fabricated when the RN exceeded the critical value of RN = 1. Additionally, the films form dense structures and bond tightly to the substrate under all RN conditions. Compared with other films, the films deposited at RN = 3 have the best mechanical and tribological properties. The hardness up to 31.70 ± 1.67 GPa, and the wear rate is as low as (3.39 ± 0.18) × 10−6 mm3/N−1m−1. Moreover, the corrosion current density in 3.5 wt% NaCl solution is only 1.119 × 10−7A/cm2, showing excellent corrosion resistance.

Merging of two droplets at an air-water interface driven by surface tension gradient

This study reports the unique phenomena of merging of two oil droplets floating on the free surface of water. For the first time, the coalescence has been initiated through the creation of a surface tension gradient by depositing the drop of surfactant at the free surface of water. The experiment reveals that droplets over water and surfactant-laden water surfaces do not merge in the absence of an external gradient, and we experimentally delineate the necessary conditions under which the coalescence of droplets will occur on the imposition of a surface tension gradient. Due to the presence of a surface tension gradient, the droplets experience a substitutional reduction in size even before coalescence, and for obvious reasons, the droplet close to the point of administration of the surfactant suffers a higher reduction in size; it also has a higher initial velocity. We studied the time-dependent variation in the neck radius (rn) formed upon the initial contact of two droplets of both identical and non-identical sizes. The final size of rn is proportional to the diameter of the droplet at the inception of the coalescence when the droplets are of identical size. For droplets of non-identical size, the final value of rn never exceeds the initial diameter of the smaller droplet. During the initial period of coalescence, rn grows with time (t) as rn≈t, but at the later stage, the rate of growth reduces as rn≈tn, where n is between 0.3 and 0.4. The relationship of rn with time in these two stages is similar to that reported in literature. However, the limit of rn for the transformation of one phase to another is significantly different in the present case compared to the other reported results.

Preliminary studies on radon concentration in CO2-rich mineral waters of the Elbrus area (Caucasus, Russia)

The geological and geochemical conditions as well as radon concentrations of ten manifestations of СО2-rich waters in the Elbrus area are considered in this paper. Also, content of uranium and thorium were measured in waters and in host rocks. The data were compared with chemical and isotopic composition of associated gases. It is established that water bearing rocks are classified into rocks of low and normal radioactivity. The contents of uranium (<1.37 μg/L) and thorium (<0.3 μg/L) in the water are low. Measurements of radon concentrations in water and gas flux of mineral springs in the Elbrus area indicate that most of them are weakly radioactive (6–33 Bq/L, 25-350 Bq/m3, respectively). The CO2-rich mineral waters of the Tyrnyauz exhibit the highest level of radioactivity (33 Bq/L) within the Elbrus area. Isotopical gas studies have shown that within the Elbrus region there is a connection with the deep horizons of the Earth's crust, from which various fluids (water and gases) can rise to the surface. Although Rn values are low and cannot be used for medical purposes, natural objects with similar characteristics can be used to observe the state of the geological environment (e.g. earthquakes) and as natural laboratories to establish the mechanisms of deep gas migration to the surface.

Towards non-iterative calculation of the zeros of the Riemann zeta function

We introduce a family of rational functions RN(a,d0,d1,…,dN) with the following property. Let d0,d1,…,dN be equal respectively to the value of some function f(s) and the values of its first N derivatives calculated at a certain complex number a lying not too far from a zero ρ of this function. It is expected that the value of RN(a,d0,d1,…,dN) is very close to ρ.We demonstrate this phenomenon on several numerical instances with the Riemann zeta function in the role of f(s). For example, for N=10 and a=0.6+14i we have |R10(a,d0,d1,…,d10)−ρ1|<10−18 where ρ1=0.5+14.13...i is the first non-trivial zeta zero.Also we define rational functions RN,n(a,d0,d1,…,dN) which (under the same assumptions) have values which are very close to n−ρ, that is, to the terms from the Dirichlet series for the zeta function calculated at its zero.In the case when a is between two consecutive zeros, say ρl and ρl+1, functions RN,n(a,d0,d1,…,dN) approximate neither of n−ρl no n−ρl+1; nevertheless, they allow us to approximate the sum n−ρl+n−ρl+1 and the product n−ρln−ρl+1 and hence to calculate both n−ρl and n−ρl+1 by solving corresponding quadratic equation.

Degassing of soil gas radon and its implication to fault activity in the western margin of the Ordos Block, China

AbstractSoil gas radon (Rn) serves as an effective indicator for assessing fault activity in fault zones. Measurement of Rn degassing at the active faults was conducted twice in 2017 and 2018 to assess fault activity in the western margin of the Ordos block. The concentration and flux values of Rn ranged from 0.41 to 40.93 kBq m−3 and 5.17 to 140.33 mBq m−2 s−1, respectively. The compression of the Tibetan Plateau has led to higher Rn concentration and flux in the southern part compared with the northern part. The fault activity is evaluated by the index of IRn calculated from Rn concentrations. The Haiyuan arcuate tectonic region exhibited the most intensive fault activity, followed by the Yinchuan Basin and Jilantai‐Linhe Basin. These findings enhance our understanding of the relationship between fault activity and Rn emission and provide a significant geochemical reference for the fault activity.

Growth, mortality and exploitation rates of Lethrinus atlanticus in the marine waters of Ghana, West Africa

Some aspects of population parameters of L. atlanticus in the marine waters of Ghana were studied from July 2018 to June 2019. Length based data were obtained from 473 samples and analyzed using the TropFishR package in R software. The growth parameters including asymptotic length (L∞), growth (K) and growth performance index (phi) were 27.0 cm TL, was 27 cm TL, 1.73 yr-1, and 3.239 respectively, with Rn value of 0.29. The total, natural and fishing mortality rate (Z) were 5.03 yr-1, 2.08 yr-1 and 2.96 yr-1 respectively Exploitation rate (E) was slightly higher than the optimum level of 0.5, suggesting that the species is sustainably exploited.

Effects of nitrogen concentration on the microstructure and mechanical properties of nanocrystalline (TiZrNbTaMo)N high-entropy nitride coatings: Experimental investigations and first-principles calculations

Novel (TiZrTaNbMo)N high-entropy alloy nitride (HEAN) coatings were prepared by double cathode glow discharge method, at various nitrogen flow ratios (RN = N2/Ar), on to Ti-6Al-4V substrates. The effects of different nitrogen pressures, RN, on the microstructure and mechanical properties of these coatings were studied by X-ray diffraction, electron microscopy and nanoindentation. Over the range of RN values investigated, from 5% to 30%, these coatings exhibit a face centered cubic (FCC) structure and are composed of equiaxed nanocrystals between 8 and 12 nm in diameter. The thicknesses of the coatings range between 14.4 and 23.6 μm, far exceeding that of typical HEAN coatings prepared by magnetron sputtering. The (TiZrTaNbMo)N coating prepared at RN = 20% exhibits the highest values for both hardness and Young's modulus (39.7 GPa and 310.2 GPa, respectively), thus approaching the level of superhard coatings. Combined with the results of first-principles calculations, one of the most important factors governing the high hardness of these coatings is the existence of both covalent and ionic bonds between the N atom and the surrounding metal atoms. Moreover, compared with most HEAN coatings, the coatings prepared by this method exhibit an improved strength-toughness balance, which is essential for surface protection.

Occurrence conditions of the reverse rotation of rockfall and its influence on the restitution coefficient

When rockfall occurs along dense rock slopes, the rotation direction of rockfall is not always downhill. Specifically, the rockfall may obtain a reverse rotation speed (RRS) after impact under certain conditions, the effect of which on the restitution coefficient (RC) cannot be ignored. According to the statistical results of the reverse rotation (RR) phenomena of blocks obtained from previous experiments, the occurrence of RR is correlated to the block shape, incident angle, and contact attitude. In this study, considering a typically shaped cubic block, the critical condition for the RR is preliminarily deduced. Based on the results, the influence of the RRS on the RC for four typically shaped blocks is examined using a customized device. Results show that the tangential RC (Rt) values of each block are not sensitive to the change in the RRS, the distribution is relatively concentrated and the values are high. Moreover, the normal RC (Rn) values are not sensitive to the RRS, and the distribution is relatively discrete. The RRS influences Rn; however, it is difficult to directly establish the relationship between them. To this end, considering the contact attitude and shape of the block, an integral variable, the impact coefficient (Ic), is proposed to determine the influence of RRS on Rn. Moreover, the impact-bounce behaviours of the block are categorized and analysed. For the block rebound following a single impact, Ic and Rn are positively and negatively correlated when the mass centre of the block (MC) is in front and behind the contact point (CP), respectively. For the block rebound following two successive impacts, with the increase in Ic, the Rn increases. These conclusions help clarify the mechanism of the influence of the RRS on RC and provide vital information and ideas for the development and optimization of a program to accurately predict rockfall trajectories.

On a characterization theorem in the space [formula omitted

By Heyde's theorem, the class of Gaussian distributions on the real line is characterized by the symmetry of the conditional distribution of one linear form of independent random variables given another. We prove an analogue of this theorem for two independent random vectors taking values in the space Rn. The obtained class of distributions consists of convolutions of Gaussian distributions and a distribution supported in a subspace, which is determined by coefficients of the linear forms.

Parameter Pertumbuhan (L∞, K , T0) dan Tingkat Kematangan Gonad Ikan Cakalang Katsuwonus pelamis

This research was conducted to determine growth patterns and gonadal maturity levels, samples were taken randomly when the fishermen unloaded the fish from the boat. The results showed that skipjack tuna (Katsuwonus pelamis) obtained a growth coefficient (K) of 1.85 per year with an asymptotic length of 75.90 cm, t0 -0.06501 years with T max maximum age = 3/K+t0 of 1 .5 years and an Rn value of 0.169. After plugging the growth value into the von Bertalanffy equation for skipjack tuna caught in the Banda seas of Maluku Province, the equation Lt=75.90{1-e-0.14(t+0.06501)} for skipjack tuna caught in Banda Sea waters. Visually, the results of observations in the field showed that female skipjack tuna entered TKG II at body length 44-59 cm, gonad length was 17.4 cm and male skipjack tuna reached TKG II at body length 43-58 cm, gonad length was 16.5 cm. The results showed that entering TKG III visually at body length measures 50.5-73.5 with a gonad length of 20 cm for female skipjack tuna and male skipjack tuna for TKG III dominates with a body length size of 70.5-79.5 cm with a gonad length of 20 cm

Evaluation of Water and Carbon Estimation Models in the Caatinga Biome Based on Remote Sensing

The study of energy, water, and carbon exchanges between ecosystems and the atmosphere is important in understanding the role of vegetation in regional microclimates. However, they are still relatively scarce when it comes to Caatinga vegetation. This study aims to identify differences in the dynamics of critical environmental variables such as net radiation (Rn), evapotranspiration (ET), and carbon fluxes (gross primary production, GPP) in contrasting recovered Caatinga (dense Caatinga, DC) and degraded Caatinga (sparse Caatinga, SC) in the state of Paraíba, northeastern Brazil. Estimates were performed using the Surface Energy Balance Algorithm for Land (SEBAL), and comparisons between estimated and measured data were conducted based on the coefficient of determination (R2). The fluxes were measured using the Eddy Covariance (EC) method for comparison with the same variables derived from Moderate Resolution Imaging Spectroradiometer (MODIS) data aboard the Terra satellite. The estimates showed higher Rn values for the DC, indicating that this area should have greater energy availability for physical, biological, and chemical processes. The R2 between daily Rn estimates and observations was 0.93. The ET estimated using the SEBAL showed higher differences in relation to the observed values; however, it presented better spatial discrimination of the surface features. The MOD16A2 algorithm, however, presented ET values closer to the observed data and agreed with the seasonality of the Enhanced Vegetation Index (EVI). The DC generally showed higher ET values than the SC, while the MODIS data (GPP MOD17A2H) presented a temporal behavior closer to the observations. The difference between the two areas was more evident in the rainy season. The R2 values between GPP and GPP MOD17A2H were 0.76 and 0.65 for DC and SC, respectively. In addition, the R2 values for GPP Observed and GPP modeled were lower, i.e., 0.28 and 0.12 for the DC and SC, respectively. The capture of CO2 is more evident for the DC considering the whole year, with the SC showing a notable increase in CO2 absorption only in the rainy season. The GPP estimated from the MOD17A2H showed a predominant underestimation but evidenced the effects of land use and land cover changes over the two areas for all seasons.

The Hi-GLASS all-wave daily net radiation product: Algorithm and product validation

The surface net radiation (Rn) represents the balance of the radiative budget on the land surface and drives many physical and biological processes. An accurate and long-term product for global daily coverage of Rn at a high spatial resolution is needed for a variety of applications at regional and local scales. This study proposes two algorithms, called the downward shortwave radiation (DSR)-based algorithm and the top-of-atmosphere (TOA)-based algorithm, to estimate Rn by using Landsat data. The DSR-based algorithm consists of three conditional models, and was developed based on the analysis of the relationship between Rn and shortwave radiation as well as ancillary information from ground measurements and various datasets. The TOA-based algorithm was developed by linking Rn to TOA observations from Landsat sensors and ancillary information. The two algorithms were developed by using the random forest method. The results of their validation against ground measurements showed that the DSR-based algorithm outperformed the TOA-based algorithm in terms of accuracy, with a determination coefficient (R2) of 0.93, root-mean-squared error (RMSE) of 17.58 Wm−2, and bias of −4.27 Wm−2. It was stable under various conditions. We then applied the DSR-based algorithm to generate a product of the global daily Rn, called the High-resolution (Hi)- Global LAnd Surface Satellite (GLASS), from 2013 to 2018 at a spatial resolution of 30 m under a clear sky based on remotely sensed products, including the DSR from GLASS, the normalized difference vegetation index (NDVI) obtained from Landsat, surface broadband albedo from Hi-GLASS, and meteorological factors based on reanalysis data from MERRA2. Following its validation using in-situ observations from 2013 to 2018, the overall accuracy of the daily Rn acquired by Hi-GLASS under clear sky was found to be satisfactory, with a value of R2 of 0.90 and an RMSE of 25.03 Wm−2. Moreover, compared with the daily Rn obtained from the GLASS product at a spatial resolution of 5 km, that obtained by Hi-GLASS can better characterize the surface by providing more details and capturing the variations in the measurements, especially large and small values. However, due to limitations of the available datasets and the algorithm, the data on Rn for most regions lacked information on cloudy skies and areas at high latitudes. This information thus cannot be provided by Hi-GLASS yet. Moreover, the influence of the topography on values of Rn has not been thoroughly considered. Nonetheless, values of Rn under clear sky obtained from Hi-GLASS offer promise for use in a wide range of areas, and efforts are underway to improve this product.

Quantitative analysis of the labia minora morphology in 400 Chinese women: A new method for assessing the shape of the labia minora.

To investigate the shape of labia minora in Chinese adult women. Women who visited the Genital Plastic Surgery Center from January 2021 to February 2022 were included and the vulvar regions were photographed. The shape of the labia minora was converted into quantifiable values [left side line segment 1-9 (L1-L9 values) and right side line segment 1-9 (R1-R9 values)]. The 400 enrolled patients were grouped by age, parity, and the types of vulvar surgeries they planned to undergo. After a graphic-to-digital and digital-to-graphic conversion, the simulated average image of the labia minora in Chinese adult women was constructed based on the mean values of L1-L9 and R1-R9. Comparing the values of Ln and Rn in the four age groups revealed that the mean values of Ln and Rn gradually decreased with age, but only two subgroups showed statistically significant differences (P-value <0.05). When the patients were stratified according to the number of births and whether labiaplasty was planned to perform, there were no significant differences among all groups (P-value >0.05). To measure and evaluate the labia minora, a new assessing method was used. It is an innovative attempt to transform the simple rough description of the shape of the labia minora into more precise data reflecting the shape features. It allows the comparison of labia minora shape between individuals by comparing quantifiable values. Besides, the average shape of labia minora in Chinese adult women was provided visually. Factors including age, parity, and whether the patient planned to undergo labiaplasty were not significantly associated with the shape of the labia minora.

ВЛИЯНИЕ ПАРАМЕТРОВ YBACUO ДЖОЗЕФСОНОВСКОГО ПЕРЕХОДА НА ХАРАКТЕРИСТИКИ ШИРОКОПОЛОСНОГО ДЕТЕКТИРОВАНИЯ

For Josephson bicrystal YBaCuO junctions 3–1.5 µm in size, the response to an external signal with a frequency of 165 GHz was measured. Receivers with similar ICRN values at helium temperatures and different RN values were chosen for the study. The amplitudes of the Shapiro steps were measured for various external signal powers and sample temperatures. The dependence of the output voltage noise on the operating point, temperature, and external signal power was measured. It is shown that fluctuations of the critical current have the greatest influence on the output noise of the receiver. The volt-watt responsivity and noise-equivalent power were evaluated for a 165 GHz external signal. The experimental results are compared with numerical calculations based on the model of a resistive-capacitive shunted Josephson junction. Optimal temperature operating ranges for the use of each structure were shown.

Effect of urbanization on energy balance and evapotranspiration in an Amazon–Cerrado transition region in Brazil

The Amazon–Cerrado transition region has a high rate of deforestation for agriculture, livestock, logging, and for the increase in urban areas of cities. The development of cities in this region in recent decades has increased the deforestation process and modified the local microclimate and the exchange of energy and water between the surface and the atmosphere. However, the magnitude of the change in energy and water exchanges due to urbanization is unknown for most Brazilian cities, especially in the Amazon–Cerrado region. Thus, the objective was to evaluate the spatiotemporal change in energy balance and in evapotranspiration (ET) patterns over three decades of urbanization in Sinop. The surface energy balance (SEB) and ET were estimated by the SEB algorithms for land with Landsat 5 Thematic Mapper images from the Sinop region, Mato Grosso, Brazil, in 1985, 2000, and 2010. The estimated SEB and ET were validated with measurements in a flux tower in the Amazon–Cerrado transition forest 50 km from the urban area of Sinop. The components of the SEB, except the soil/storage heat flux (G), had a strong correlation, and the ET had a moderate correlation with measurements in the flux tower. The surface albedo (asup), land surface temperature (LST), sensible heat flux (H), and G of the study area increased over the years, while the normalized difference vegetation index, latent heat flux (LE), and ET decreased over the years. Buildup and grassland areas had lower values of NDVI, Rn, LE, and ET and higher values of asup, LST, H, and G than forest areas. Therefore, the urbanization of Sinop has decreased available energy for ET and increased the energy to heat the air and soil.

Lower Bounds on Multivariate Higher Order Derivatives of Differential Entropy.

This paper studies the properties of the derivatives of differential entropy in Costa’s entropy power inequality. For real-valued random variables, Cheng and Geng conjectured that for , , while McKean conjectured a stronger statement, whereby . Here, we study the higher dimensional analogues of these conjectures. In particular, we study the veracity of the following two statements: , where n denotes that is a random vector taking values in , and similarly, . In this paper, we prove some new multivariate cases: . Motivated by our results, we further propose a weaker version of McKean’s conjecture , which is implied by and implies . We prove some multivariate cases of this conjecture under the log-concave condition: and . A systematic procedure to prove is proposed based on symbolic computation and semidefinite programming, and all the new results mentioned above are explicitly and strictly proved using this procedure.

Characterisation of valuations and curvature measures in euclidean spaces

Valuations constitute a class of functionals on convex bodies which include the Euler-characteristic, the surface area, the Lebesgue-measure, and many more classical functionals. Curvature measures may be regarded as “localised” versions of valuations which yield local information about the geometry of a body’s boundary. A complete classification of continuous translation-invariant SO(n)-invariant valuations and curvature measures with values in ℝ was obtained by Hadwiger and Schneider, respectively. More recently, characterisation results have been achieved for curvature measures with values in Symp ℝn and Sym2Λqℝn for p, q ≥ 1 with varying assumptions as for their invariance properties. In the present work, we classify all smooth translation-invariant SO(n)-equivariant curvature measures with values in any SO(n)-representation in terms of certain differential forms on the sphere bundle Sℝn and describe their behaviour under the globalisation map. The latter result also yields a similar classification of all continuous SO(n)-equivariant valuations with values in any SO(n)-representation. Furthermore, a decomposition of the space of smooth translation-invariant ℝ-valued curvature measures as an SO(n)-representation is obtained. As a corollary, we construct an explicit basis of continuous translation-invariant ℝ-valued valuations.