Miracle-dz/UniFAR-FTUs huggingface dataset:
X-ray study of strains and dislocation density in epitaxial Cu/Ni/Cu/Si(001) films

The strain state of epitaxial Cu(50h{Angstrom})/Ni(t{sub Ni})/Cu(2000h{Angstrom})/Si(001) films as a function of the nickel film thickness (30h{Angstrom}{le}t{sub Ni}{le}2000h{Angstrom}) has been studied using Bragg diffraction and grazing-incidence diffraction with a synchrotron x-ray source. For 30h{Angstrom}{le}t{sub Ni}{le}150h{Angstrom} both the in-plane and out-of-plane nickel strains show a phenomenological (1/t){sup 2/3} power dependence, which is significantly different from the 1/t law commonly accepted in the literature. The Matthews{close_quote} theory, including the effect of the copper capping layer, is used to account for the equilibrium strains of the nickel layer. The 500 and 2000 {Angstrom} films show larger strains than that predicted by the theory, consistent with other studies. The ratio of the nickel in-plane to out-of-plane strains is {minus}1.18{plus_minus}0.05, very close to the expected nickel bulk value of {minus}2c{sub 12}/c{sub 11}={minus}1.28. {copyright} {ital 1999} {ital The American Physical Society}
Importance of Antiviral and Antibacterial Face Mask Used in Pandemics: An Overview

ABSTRACT Community-wide mask wearing may contribute to the control of COVID-19 by reducing the amount of emission of infected saliva and respiratory droplets from individuals with subclinical or mild COVID-19. In this work, a brief review is presented on face masks and related things. First, the size of microorganisms in relation to PM2.5 and PM10 is given for an approximate estimate of the sizes of objects that needs to be filtered. In continuation, the principles of filtration of objects by the network of fibers (woven, non-woven, knitted, etc.) are given. Common fibers used for making face mask is presented along with various fabric structure and their manufacturing. Additionally, advancements like the treatment of fibers in terms of coated fabrics, nano-particle finishes, and green synthesized nano-particle coatings have been explained in view of their anti-bacterial and anti-viral properties. The classification of the face masks based on their fabric make-up has been given which has been extended to classification based on the barrier properties and various efficiencies of the face masks. The characterization of face masks like particle filtration efficiency, bacterial filtration efficiency, breathing resistance, flash resistance, and flame resistance are also included.
Cobalt hydroxide nanoflakes intercalated into nitrogen-doped reduced graphene oxide’s nanosheets for supercapattery application

In this study, we report a one-step method to synthesize Co(OH)_2 nanoflakes intercalated into nitrogen-doped graphene oxide (NrGO). The NrGO-Co(OH)_2 (abbreviated as NRCO) nanocomposite is used as a positrode to fabricate a supercapattery device with activated carbon as the negative electrode. The surface morphology and microstructure of the NRCO nanocomposites were confirmed by field emission scanning electron microscope imaging and the structure was analysed by X-ray diffraction and Raman spectroscopy. The electrochemical performances of the NRCO nanocomposite electrode are examined using cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge/discharge measurement. The NRCO nanocomposite electrode displayed a specific capacity of 75.2 C/g in a 1 M KOH aqueous electrolyte. The cycle life of the supercapattery device fabricated with NRCO nanocomposite [with 2 wt. % CO(OH)_2] exhibits a specific capacity to retain 93.1% of its initial capacity even after completing 3000 continuous charge/discharge cycles, which shows its potential among current energy storage devices. Graphical abstract
Optical properties measurement of laser coagulated tissues with double integrating sphere and inverse Monte Carlo technique in the wavelength range from 350 to 2100 nm

In laser medicine, the accurate knowledge about the optical properties (absorption coefficient; μa, scattering coefficient; μs, anisotropy factor; g) of laser irradiated tissues is important for the prediction of light propagation in tissues, since the efficacy of laser treatment depends on the photon propagation within the irradiated tissues. Thus, it is likely that the optical properties of tissues at near-ultraviolet, visible and near-infrared wavelengths will be more important due to more biomedical applications of lasers will be developed. For improvement of the laser induced thermotherapy, the optical property change during laser treatment should be considered in the wide wavelength range. For estimation of the optical properties of the biological tissues, the optical properties measurement system with a double integrating sphere setup and an inverse Monte Carlo technique was developed. The optical properties of chicken muscle tissue were measured in the native state and after laser coagulation using the optical properties measurement system in the wavelength range from 350 to 2100 nm. A CO2 laser was used for laser coagulation. After laser coagulation, the reduced scattering coefficient of the tissue increased. And, the optical penetration depth decreased. For improvement of the treatment depth during laser coagulation, a quantitative procedure using the treated tissue optical properties for determination of the irradiation power density following light penetration decrease might be important in clinic.
Gender Differences in Emotional Valence and Social Media Content Engagement Behaviors in Pandemic Diaries: An Analysis Based on Microblog Texts

The effects of the COVID-19 pandemic are individualized, which means that our emotions and behaviors would experience changes of different degrees. These changes have led to subtle connections within the social media context. This study concentrates on pandemic diaries posted on microblog sites during the lockdown period in China and explores the association between gender, emotional valence in diaries, and social media content engagement behaviors. Through computational methods, this study found that males and females tended to present significantly different emotional valence and social media content engagement behaviors. A negative correlation existed between emotional valence and comment behavior in female diary texts. Moreover, the pandemic proximity had a moderating effect on emotional valence and social media content engagement behaviors. This article attempts to explain the emotional and behavioral characteristics related to social media diaries and express concerns for the emotional health of disadvantaged blog users in the severely affected area during the pandemic.
Nonlinear compressible convection penetrating into stable layers and producing internal gravity waves

Penetrative convection spanning multiple scale heights is studied within a simple stellar envelope consisting of three layers: a convectively unstable middle layer bounded above and below by stably stratified polytropes. Two-dimensional numerical simulations are used to investigate the fully compressible nonlinear motions that ensue. The cellular flows display prominent downward-directd plumes surrounded by broader regions of upflow. Such asymmetry arises because pressure fluctuations accentuate buoyancy driving in the concentrated plumes and can even lead to weak buoyancy braking in the surrounding ascending flows. As the plumes plunge downward into a region of stable stratification, they serve to excite a broad spectrum of internal gravity waves there. The induced waves are not passive, for they feed back upon the plumes by deflecting them sideways, thereby modulating the amplitude of the convection in time even in the unstable layer. The penetrative motions that billow upward into the upper stable zone are distinctly weaker, and they cascade back downward toward the unstable zone over a broad horizontal scale. The strong excitation of gravity waves by the convection has implications for gradual mixing deep within a star.
Beam shaping with a laser amplifier

We propose a new technique for laser beam shaping namely the reshaping of the laser beam into a desirable beam profile by the use of a laser amplifier with a pump beam that has a modified intensity profile. We developed the analytical formula which describes the transformation of the seed beam into the desired beam profile in the amplifiers small signal regime. In the case were high pump power saturated the laser crystal we have shown the method of reshaping of the seed beam into desirable beam by a numerically obtained pump intensity profile. The method can also be extended for shaped seed beams with fixed profile pump.
The Spatio-Temporal Patterns of Glacier Activities in the Eastern Pamir Plateau Investigated by Time Series Sub-Pixel Offsets From Sentinel-2 Optical Images

The eastern Pamir Plateau, with a mean altitude of 5000 m, forms a large-scale glacier region with a size of 2054 km2 that serves as an important environmental climate condition for central Asia. In this article, we estimated the spatio-temporal patterns of glacier activities in this region by using the time series sub-pixel offsets derived from 63 sentinel-2 optical images between December 31, 2020 and December 31, 2021. Our results indicated the mean glacier flow velocity in this region was 0.531 m/d ± 0.007 m/d in 2021, and the Kongur Tagh Glacier was much more active than the Kingata Glacier and Muztagh Ata Glacier. The time series observations revealed that the glacier motion involves a pre-melting period (January–April) with a velocity of 0.600 m/d ± 0.012 m/d, a melting period (May–August) with a velocity of 0.608 m/d ± 0.003 m/d, and a post-melting period (September–December) with a velocity of 0.659 m/d ± 0.006 m/d. In order to get insights into the characteristics of these glacier activities, we carried out a correlation analysis between the glacier flow velocity change and its potential caused reasons (i.e., topography, temperature, precipitation, glacier surges, debris-cover, and glacier thickness), and current results suggest that the glacier flow velocity is influenced by a combination of these factors.
Bayesian inference for non‐stationary spatial covariance structure via spatial deformations

Summary. In geostatistics it is common practice to assume that the underlying spatial process is stationary and isotropic, i.e. the spatial distribution is unchanged when the origin of the index set is translated and under rotation about the origin. However, in environmental problems, such assumptions are not realistic since local influences in the correlation structure of the spatial process may be found in the data. The paper proposes a Bayesian model to address the anisot‐ ropy problem. Following Sampson and Guttorp, we define the correlation function of the spatial process by reference to a latent space, denoted by D, where stationarity and isotropy hold. The space where the gauged monitoring sites lie is denoted by G. We adopt a Bayesian approach in which the mapping between G and D is represented by an unknown function d(·). A Gaussian process prior distribution is defined for d(·). Unlike the Sampson–Guttorp approach, the mapping of both gauged and ungauged sites is handled in a single framework, and predictive inferences take explicit account of uncertainty in the mapping. Markov chain Monte Carlo methods are used to obtain samples from the posterior distributions. Two examples are discussed: a simulated data set and the solar radiation data set that also was analysed by Sampson and Guttorp.
Consequences of vacuum instability in quantum field theory

When the effective potential of a quantum field theory has nonglobal minima, the question arises as to whether they may correspond to the vacuum state. The conventional response is negative because of vacuum instability and also on the basis of an analogy with many-body theory where the effective potential is compared to the Helmholtz free energy for which certain convexity properties may be proved using Van Hove's theorem. In pursuing an alternative possibility, it is pointed out here that when a nonglobal minium of the potential occurs, the field equations can sustain a pseudoparticlelike classical solution in four-dimensional Euclidean space-time and a corresponding soliton solution in three-dimensional space. The existence of these solutions is not inconsistent with Derrick's theorem which assumes that the vacuum is an absolute minimum. The solutions are interpreted physically in Minkowski space as vacuum bubbles created by quantum tunneling from the metastable vacuum to one of lower energy. Thus explicit calculations of the decay probability are rendered feasible. A simple theory where the phenomenon occurs is the skewed Goldstone model, which is studied in detail. Extension to Higgs-Kibble gauge theories is straightforward. As an example, in the Weinberg-Salam theory the lower limit on the Higgs massmore » derived by Weinberg and Linde, and the limit derived by Gildener and Weinberg for the modified version incorporating a dimensional transmutation mechanism, can be significantly modified. For the original version of the theory, the lower limit is changed from 4.91 GeV to about 3.5 GeV, for mixing angle theta/sub W/ = 35degree. For this new range of masses the vacuum is totally secure, for practical purposes, against spontaneous bubble formation by vacuum fluctuations. « less
A Comparison of OLR and Circulation-Based Indices for Tracking the MJO

AbstractTwo univariate indices of the Madden–Julian oscillation (MJO) based on outgoing longwave radiation (OLR) are developed to track the convective component of the MJO while taking into account the seasonal cycle. These are compared with the all-season Real-time Multivariate MJO (RMM) index of Wheeler and Hendon derived from a multivariate EOF of circulation and OLR. The gross features of the OLR and circulation of composite MJOs are similar regardless of the index, although RMM is characterized by stronger circulation. Diversity in the amplitude and phase of individual MJO events between the indices is much more evident; this is demonstrated using examples from the Dynamics of the Madden–Julian Oscillation (DYNAMO) field campaign and the Year of Tropical Convection (YOTC) virtual campaign. The use of different indices can lead to quite disparate conclusions concerning MJO timing and strength, and even as to whether or not an MJO has occurred. A disadvantage of using daily OLR as an EOF basis is that .
Variabilities in Urban Ambient Noise Before, During, and After Covid-19
 Lockdown in the Peruvian Capital

ABSTRACT. Recent studies have shown that urban ambient noise (UAN) decreased at many sites due to a slowdown in human activities brought by the SARS-CoV-2 (COVID-19) pandemic lockdowns. Such understanding is inferred from the historical record of the noise levels, which may also help us disambiguate noise sources as required for ambient noise tomography, microseismic and other seismic based studies. As UAN is site-specific, and its analysis enables passive situational awareness, therefore, in the present study, we analyzed the temporal variations in UAN before, during and after the social isolation in the metropolitan region of Lima, the capital of Peru, for the very first time. We used continuous waveforms recorded from February 1st to August 31st, 2020, at the Ñaña (NNA) broadband seismic station for the analysis. Results show the temporal changes occur in different frequency ranges; for example, at frequencies >1 Hz, significant changes in the mean daytime amplitudes are observed, which are absent in the lower frequency range (0.1–1, 1–3, 3–5 Hz). A maximum noise reduction of 37% is observed and should be considered for any future application of UAN. The results were verified by comparing with Community Mobility Reports (CMR) provided by Google using statistical change-point analysis.
Grüss-type bounds for covariances and the notion of quadrant dependence in expectation

We show that Grüss-type probabilistic inequalities for covariances can be considerably sharpened when the underlying random variables are quadrant dependent in expectation (QDE). The herein established covariance bounds not only sharpen the classical Grüss inequality but also improve upon recently derived Grüss-type bounds under the assumption of quadrant dependency (QD), which is stronger than QDE. We illustrate our general results with examples based on specially devised bivariate distributions that are QDE but not QD. Such results play important roles in decision making under uncertainty, and particularly in areas such as economics, finance, and insurance.
Genome-Wide Analysis of WRKY Gene Family and Negative Regulation of GhWRKY25 and GhWRKY33 Reveal Their Role in Whitefly and Drought Stress Tolerance in Cotton

The WRKY transcription factor family is marked by its significant responsiveness to both biotic and abiotic plant stresses. In the present study, the WRKY family of Gossypium hirsutum has been identified and classified into three groups based on the number of conserved WRKY domains and the type of zinc finger motif. This classification is further validated by conserved domain and phylogenetic analysis. Two members of the WRKY family, WRKY25 and WRKY33, have been targeted through VIGS in G. hirsutum. VIGS-infiltrated plants were evaluated under drought stress and whitefly infestation. It was observed that GhWRKY33-downregulated plants showed a decrease in whitefly egg and nymph population, and GhWRKY33 was found to be a strong negative regulator of whitefly and drought stress, while GhWRKY25 was found to be a moderate negative regulator of whitefly and drought stress. As the targeted genes are transcription factors influencing the expression of other genes, the relative expression of other stress-responsive genes, namely MPK6, WRKY40, HSP, ERF1, and JAZ1, was also analyzed through qRT-PCR. It was found elevated in GhWRKY33-downregulated plants, while GhWRKY25-downregulated plants through VIGS showed the elevated expression of ERF1 and WRKY40, a slightly increased expression of HSP, and a lower expression level of MPK6. Overall, this study provides an important insight into the WRKY TF family and the role of two WRKY TFs in G. hirsutum under drought stress and whitefly infestation. The findings will help to develop crops resilient to drought and whitefly stress.
Wideband Circularly Polarized Millimeter-Wave DRA Array for Internet of Things

This work proposes a novel millimeter-wave (mm-wave) wideband circularly polarized (CP) antenna array for Internet of Things (IoT) applications. The proposed design addresses the issues of having IoT sensors deployed in remote locations or over large geographical regions. Elliptically shaped dielectric resonator antennas (DRAs) are used as array elements to improve radiation characteristics and achieve circular polarization over a wide impedance bandwidth around 28 GHz. Two different sequential-phase corporate feed networks are studied and compared to obtain wider impedance, 3-dB gain, and axial ratio (AR) bandwidths. Furthermore, a ridge gap waveguide technique based on the low-cost PCB technology is adopted to reduce the transmission losses in the considered sequential-phase feed networks. The proposed mm-wave antenna exhibits an impedance bandwidth of 35% (28.1–40 GHz) and 3-dB gain bandwidth of 19.3% (27.6–33.5 GHz). The achieved 3-dB AR bandwidth is 22.6% (27.5–34.5 GHz). The proposed antenna was fabricated and measured, and good agreement between measured and simulated results was obtained. The reported results show that the suggested wideband CP mm-wave antenna has a lot of promise in preventing polarization mismatch losses between IoT devices and satellites caused by their varying orientations.
A self-similar model for extragalactic radio sources

An analytical model for extragalactic radio sources with pressure-confined jets is presented. We show that the properties of the bow shock and of the gas surrounding these objects force the sources to grow in a self-similar way provided the density in the external atmosphere falls less steeply than 1/d^2. Results from observations and numerical simulations are used to develop a self-consistent model for the large-scale structure of FRII objects. The jets in these sources are shown to be stable against turbulence for the observed properties of FRIIs and the divide between FRI and FRII objects in jet power is reproduced. The overall dynamics of a source are derived as a function of time and depend on the external density, the jet power and the scaleheight of the external atmosphere. Derived dynamical ages are consistent with observed spectral ages.
Perspectives on agroecological transition: the case of Guachetá municipality, Colombia

ABSTRACT Specialization of agriculture in the Colombian Andes has increased smallholder vulnerability to climate change and global price fluctuations and has also affected the socio-economic and environmental conditions. Promoting sustainable agriculture in the region requires a holistic understanding of complex agroecosystems. This study identifies and analyzes the main challenges for agriculture and possibilities for agroecological transition of small-scale farms in Guachetá, Colombia. Using the Tool for Agroecology Performance Evaluation (TAPE), 10 elements of agroecology and core performance criteria were evaluated on seven farms. Several key actors were then interviewed, to triangulate data and understand current challenges and possible future pathways. It was found that drier climate and variations in rainfall patterns pose major challenges to current production systems. Limited possibilities for participation in land governance, lack of interest in agriculture among young people, and lack of access to markets hinder the development of sustainable agriculture. Current specialized practices in dairy and potato production are associated with reduced agricultural biodiversity and dependency on agrochemicals, leading to weak synergies and low profitability within agroecosystems. Implementation of agroecological principles and practices such as crop and income diversification and promoting joint action in agricultural development could help overcome sustainability issues in Guachetá. GRAPHICAL ABSTRACT
The Prediction of ‘Maximal’ Oxygen Consumption Using a New Progressive Step Test

A description is given of a ‘ progressive ’ step test where the speed of ascent of two 9 in. steps is progressively increased. The validity of this test is established in terms of (1) the rate of approach to a steady-state, (2) a comparison of measured variables in the ‘ steady-state ’ and ‘ progressive ’ tests, and (3) a comparison of data for ‘ maximal ’ oxygen intake with predictions from the ‘ progressive ’ and ‘ steady-state ’ step tests. The 9 in. step is subjectively more comfortable than an 18 in. step teat. The efficiency of working is independent of step height over the range 9-18 in. , but varies with the speed of stepping. Variations in efficiency are no greater than for the bicycle ergometer at comparable rates of working. Methods of predicting ‘ maximal ’ oxygen uptake are critically reviewed. The pulse rates during performance of the 9 in. progressive step test agree quite well with Astrand's findings at comparable levels of oxygen consumption. When the test is performed in the laboratory, t.