bluuebunny/crossref_metadata_2025_split huggingface dataset:
A quest to extend friction law into multiscale soft matter: experiment confronted with theory—a review
Authors: Bełdowski Piotr , Gadomski Adam 
Published: September 2022

Abstract
This topical review focuses on applying the basics of the classical Coulomb–Amontons (CA) law of friction to describe bioinspired articulating systems of extremely low values of coefficients of friction (COFs). A quest to extend the CA law is thoroughly formulated and the complex biotribological circumstances are readily drawn. A starting conceptual platform is established to address the quest as belonging more to biological physics than physical-biology contexts. First, an applied-physics viewpoint is unveiled by presenting theoretical, experimental, and computer-simulation methods, pointing uniquely to the fact that the biological, mainly cellular, contribution to the problem cannot be solved satisfactorily by employing physical laws and tools only. However, a consecutive and systematic way of modifying the COFs by carefully expanding these quantities into series is sketched. Second, this viewpoint is compared with a nonequilibrium-thermodynamics framework up to the far-from-equilibrium, dissipative-structure addressing regime. This complex picture is corroborated with a random-walk type approach, mostly pertinent to the nanoscale, with an emphasis placed on the ubiquitous quantity, which is the huge number of hydrogen ions resulting from anomalous hydronium ions transport in water, changing in terms of pH values the acid-base solution conditions. The overall complex framework that is described, capable of unveiling kinetic-friction conditions (associated virtually with the random-walk of hydrogen ions), is supposed to mimic, or compensate, the biotribological contribution envisaged in terms of cellular productivity of chondrocytes/synoviocytes. Such productivity is necessary to maintain the friction-lubrication phenomenon as shown up in articular (bio)devices (knees, hips, jaws, elbows, etc) at ultralow COF-levels of 10−3 or less, and is greatly facilitated due to reduced overall dissipation and often nonlinear pathways at the meso- and nanoscale. In this way, a novel insight into the biotribological phenomenon of practical interest concerning versatile viscosupplementation and arthroscopic reparation strategies is gained.
Quantitative analyses of surface and bulk magnetization in Nd2Fe14B and SmCo5 single crystals: towards understanding the large N
eff in nucleation-type magnets
Authors: Karpenkov A Yu , Skokov K P , Dunaeva G G , Semenova E M , Lyakhova M B , Pastushenkov Yu G 
Published: September 2022

Abstract
The performance of sintered permanent magnets with nucleation-type coercivity mechanism is largely governed by the magnetic state of thin surface layers of constituent grains, and a deeper insight into magnetization–demagnetization processes occurring in the shell part of the grains is very important for further improvement of hard magnetic materials. In this work, we used Nd2Fe14B and SmCo5 single crystals as model objects. By applying magneto-optical Kerr microscopy and conventional magnetometry, we compare the magnetization–demagnetization processes occurring in the thin surface layer and in the volume of both single crystals. We show that upon magnetization along the c-axis, the volume of the single crystals saturates in the field, rigorously determined by demagnetization factor of the bulk sample, whereas in the surface layer a magnetic domain structure exists up to 1.88 T in Nd2Fe14B and 1.19 T in SmCo5 regardless of their bulk demagnetization factors. This means that the surface layer with orientation perpendicular to c-axis magnetizes as a thin magnetic film and has an effective demagnetization factor
N
eff
∼ 1. We also show that this effect can be reproduced in the framework of conventional finite element method modeling but the analytical solution of this problem still needs to be found. We believe that our findings can be useful for understanding of the formation of a high coercive state in nucleation-type permanent magnets, where the phenomenological concept of the large effective demagnetization factor
N
eff
plays an important role.
Performance degradation prediction model of rolling bearing based on self-checking long short-term memory network
Authors: Lan Xiaosheng , Li Yunfeng , Su Yuanhao , Meng Liang , Kong Xiaojia , Xu Tongle 
Published: September 2022

Abstract
The prediction of performance degradation is of great significance for the health monitoring of rolling bearings. When predicting the performance degradation trend for the whole-life data of bearings, there are problems such as long prediction time, high cost and single evaluation criteria for prediction effect, which hinder the accuracy of degradation prediction. To this end, a self-checking long and short-term memory (Sc-LSTM) prediction model is proposed in this paper for predicting the performance degradation trend of bearings. First, Relation was used as a performance degradation indicator and improved using the mean and normalization methods. This approach can effectively alleviate the problems of long forecasting time and high cost. Secondly, the long and short-term memory (LSTM) sets up many different prediction schemes and proposes a test layer by segmental prediction and comparison to select the appropriate test index σ. According to the robust stability of the self-checking method and the high accuracy of LSTM nonlinear prediction, an Sc-LSTM performance degradation prediction model is established. The model introduces the prediction effect assessment of prediction pass rate η to make up for the problem of inadequate assessment of prediction effect by a single error. Finally, using the Sc-LSTM model, relation is used to perform segmental predictive analysis and experimental validation of the overall prediction. Experiments show that the model can effectively improve the prediction accuracy and is feasible in the prediction of bearing performance degradation.
An efficient rectangular optimization method for sparse orthogonal collimator based small animal irradiation
Authors: Jiang Lu , Lyu Qihui , Abdelhamid Amr M H , Hui Susanta , Sheng Ke 
Published: September 2022

Abstract

Objective. Intensity-modulated radiotherapy (IMRT) is widely used in clinical radiotherapy, treating varying malignancies with conformal doses. As the test field for clinical translation, preclinical small animal experiments need to mimic the human radiotherapy condition, including IMRT. However, small animal IMRT is a systematic challenge due to the lack of corresponding hardware and software for miniaturized targets. Approach. The sparse orthogonal collimators (SOC) based on the direct rectangular aperture optimization (RAO) substantially simplified the hardware for miniaturization. This study investigates and evaluates a significantly improved RAO algorithm for complex mouse irradiation using SOC. Because the Kronecker product representation of the rectangular aperture is the main limitation of the computational performance, we reformulated matrix multiplication in the data fidelity term using multiplication with small matrices instead of the Kronecker product of the dose loading matrices. Solving the optimization problem was further accelerated using the Fast Iterative Shrinkage-Thresholding Algorithm (FISTA). Main results. Four mouse cases, including a liver, a brain tumor, a concave U-target, and a complex total marrow irradiation (TMI) case, were included in this study with manually delineated targets and OARs. Seven coplanar-field SOC IMRT (sIMRT) plans were compared with idealistic fluence map based IMRT (iIMRT) plans. For the first three cases with simpler and smaller targets, the differences between sIMRT plans and iIMRT plans in the planning target volumes (PTV) statistics are within 1%. For the TMI case, the sIMRT plans are superior in reducing hot spots (also termed D
max) of PTV, kidneys, lungs, heart, and bowel by 20.5%, 31.5%, 24.67%, 20.13%, and 17.78%, respectively. On average, in four cases in this study, the sIMRT plan conformity is comparable to that of the iIMRT’s with lightly increased R50 and Integral Dose by 2.23% and 2.78%. Significance. The significantly improved sIMRT optimization method allows fast plan creation in under 1 min for smaller targets and makes complex TMI planning feasible while achieving comparable dosimetry to idealistic IMRT with fluence map optimization.
State enhanced actinometry in the COST microplasma jet
Authors: Steuer David , van Impel Henrik , Gibson Andrew R , Schulz-von der Gathen Volker , Böke Marc , Golda Judith 
Published: September 2022

Abstract
A new actinometry approach, helium state enhanced actinometry (SEA), is presented. This diagnostic uses the emission of the atomic states O(3p3P) (λ = 844.6 nm), Ar(2p1) (λ = 750.4 nm) and He(33S) (λ = 706.5 nm) and allows the atomic oxygen density and the mean electron energy to be determined simultaneously from the spectral line intensity ratios. Here, the atomic states are selected in a way that they cover a wide range of the electron energy distribution function (EEDF). The method is compared to the classical actinometry approach and energy resolved actinometry (ERA) based on measurements on the COST microplasma jet. In addition, a benchmark against two-photon absorption laser induced fluorescence measurements is performed. Both atomic oxygen densities and mean electron energies are in good agreement with the literature. Furthermore, SEA offers a number of advantages over known approaches. Firstly, the experimental complexity is significantly reduced by using time-integrated spectra instead of phase-resolved measurements, as used in the original ERA approach. Secondly, the precision of the electron energy measurement can be significantly improved by the use of the helium state. In addition, known uncertainties e.g. due to excitation of oxygen excited levels via metastable oxygen states can be reduced.
Electrical properties and microstructure of V/Al/Ni/Au contacts on n-Al0.65Ga0.35N:Si with different Au thicknesses and annealing temperatures
Authors: Cho H K , Mogilatenko A , Susilo N , Ostermay I , Seifert S , Wernicke T , Kneissl M , Einfeldt S 
Published: September 2022

Abstract
We investigated the formation of ohmic contacts as a result of intermetallic phase formation between V, Al, Ni, and Au in V/Al/Ni/Au metal stacks on n-Al0.65Ga0.35N:Si. In particular, the influence of Au metal thickness and annealing temperature was analysed. The lowest annealing temperature of 750 °C for an ohmic contact with a smooth surface and a contact resistivity of about 2.4 × 10−5 Ωcm2 was achieved for V(15 nm)/Al(120 nm)/Ni(20 nm)/Au(40 nm). The lowest contact resistivity is accompanied by formation of two thin interfacial regions consisting of AlN and an Au-rich phase. We suggest that not only the formation of thin interfacial AlN layer is important for a low contact resistance, but also the formation of the Au-rich interface can have a favourable effect on the contact properties.
Inverse design of broadband, strongly-coupled plexcitonic nonlinear metasurfaces
Authors: Blechman Yael , Tsesses Shai , Bartal Guy , Almeida Euclides 
Published: September 2022

Abstract
Hybrid photonic structures of plasmonic metasurfaces coupled to atomically thin semiconductors have emerged as a versatile platform for strong light–matter interaction, supporting both strong coupling and parametric nonlinearities. However, designing optimized nonlinear hybrid metasurfaces is a complex task, as the multiple parameters’ contribution to the nonlinear response is elusive. Here we present a simple yet powerful strategy for maximizing the nonlinear response of the hybrid structures based on evolutionary inverse design of the metasurface’s near-field enhancement around the excitonic frequency. We show that the strong coupling greatly enhances the nonlinear signal, and that its magnitude is mainly determined by the Rabi splitting, making it robust to geometrical variations of the metasurface. Furthermore, the large Rabi splitting attained by these hybrid structures enables broadband operation over the frequencies of the hybridized modes. Our results constitute a significant step toward achieving flexible nonlinear control, which can benefit applications in nonlinear frequency conversion, all-optical switching, and phase-controlled nonlinear metasurfaces.
Coupling of ‘cold’ electron plasma wave via stationary ion inhomogeneity to the plasma bulk
Authors: Kumar Pandey Sanjeev , Mahapatra Jagannath , Ganesh Rajaraman 
Published: September 2022

Abstract
Using high resolution kinetic (VPPM-OMP 1.0) and fluid (BOUT++) solvers, evolution of long-wavelength electron plasma wave (EPW) in the presence of stationary periodic ion background non-uniformity is investigated. Mode coupling dynamics between long-wavelength EPW mode of scale k and ion inhomogeneity of scale k
0 is illustrated. Validity of well known Bessel function J

n
(x) scaling in the cold plasma approximation (i.e., when phase velocity ω/k ≫ v

thermal
) alongwith the effect of ion inhomogeneity amplitude (A) on temporal evolution of energy density in the long-wavelength EPW mode is investigated. Effect of finite system sizes on the Bessel J

n
(x) scaling is examined and scaling law for τ

FM
i.e the time required to attain first minimum of energy density of the corresponding perturbed mode (also called phase mixing time for k ⟶ 0 modes) versus ion inhomogeneity amplitude A obtained from both kinetic and fluid solutions for each of the cases studied, alongwith some major differences in τ

FM
scaling for small system sizes is also reported.
Distribution of radial dose in water at nanometer scale for ions of the same linear energy transfer: benefits of the concept of annular dose
Authors: Awad El-Sayed , Abu-Shady Mohamed , Fromm Michel 
Published: September 2022

Abstract
Annular-dose AD is a new conception , based on the radial dose distribution, RDD, introduced by the present work. AD is the integrated dose for many shells around the ions and it is defined as the dose deposited in the shell volume perpendicular to the ion path of width

(
r
=
0.1
→

R

min

)
,

length equal

2
π

and thickness equal unity (1 nm). Thus, it integrates and maps the deposited dose due to ion in any medium at nanometer scale better than the ordinary radial dose. Katz and Awad radial dose formulae plus Butts-Katz and Tabata electron range-energy relations are composing three different approaches. These approaches were used for studying the AD for 30 ions forming 4 different equal LET groups and have energy at Bragg peak region from 1.5 to 24 MeV n−1. The annular dose, AD as a function of the shell width for the ions under investigation showed that dose distributions around the ions of same LET are not the same and a clear peak at certain shell width called the ion’s maximum annular dose width, r

MADW
was determined for the first time. The r

MADW
is the position where the maximum reachable dose is delivered by secondary electrons around the ion. The ion’s r

MADW
showed an increasing function with Z*β within the same LET group. Interestingly, it was found that r

MADW
behaves as an increasing monotonic function of the relative ion velocity, β using the three approaches considered in this work.
Primordial stochastic gravitational wave background anisotropies: in-in formalization and applications
Authors: Dimastrogiovanni Ema , Fasiello Matteo , Pinol Lucas 
Published: September 2022

Abstract
Primordial non-Gaussianities of the scalar(tensor)-tensor-tensor type supporting a
non-trivial squeezed component are known to induce anisotropies in the stochastic gravitational
wave background. We derive the explicit form of such anisotropies by making use, for the first
time in this context, of the in-in formalism for cosmological correlation functions. After
illustrating the general method and using it for the minimal single-field slow-roll case, we apply
it to multi-field models, providing both a tree-level and a one-loop example. First, we make
contact with previous results on anisotropies due to the presence of an extra spin-2 field during
inflation. Secondly, we calculate the 1-loop scalar-tensor-tensor three-point function in the
context of so-called supersolid inflation. The corresponding gravitational wave anisotropy is
induced atop a gravitational signal that may be sufficiently large for detection.
Does inflation squeeze cosmological perturbations?
Authors: Agullo Ivan , Bonga Béatrice , Ribes Metidieri Patricia 
Published: September 2022

Abstract
There seems to exist agreement about the fact that inflation squeezes the quantum state of
cosmological perturbations and entangles modes with wavenumbers k⟶ and -k⟶. Paradoxically, this result has been used to justify both the classicality as well as the
quantumness of the primordial perturbations at the end of inflation. We reexamine this question
and point out that the definition of two-mode squeezing of the modes k⟶ and -k⟶ used
in previous work rests on choices that are only justified for systems with time-independent
Hamiltonians and finitely many degrees of freedom. We argue that for quantum fields propagating on
generic time-dependent Friedmann-Lemaître-Robertson-Walker backgrounds, the notion of squeezed
states is subject to ambiguities, which go hand in hand with the ambiguity in the definition of
particles. In other words, we argue that the question “does the cosmic expansion squeeze and
entangle modes with wavenumbers k⟶ and -k⟶?” contains the same ambiguity as the
question “does the cosmic expansion create particles?”. When additional symmetries are present,
like in the (quasi) de Sitter-like spacetimes used in inflationary models, one can resolve the
ambiguities, and we find that the answer to the question in the title turns out to be in the
negative. We further argue that this fact does not make the state of cosmological perturbations
any less quantum, at least when deviations from Gaussianity can be neglected.
The halo 3-point correlation function: a methodological analysis
Authors: Veropalumbo A. , Binetti A. , Branchini E. , Moresco M. , Monaco P. , Oddo A. , Sánchez A.G. , Sefusatti E. 
Published: September 2022

AbstractUpcoming galaxy surveys will provide us with an unprecedented view of the Large-Scale Structure of the Universe and the realistic chance to extract valuable astrophysical and cosmological information from higher-order clustering statistics. This perspective poses new challenges, requiring both accurate and efficient estimators and a renewed assessment of possible systematic errors in the theoretical models and likelihood assumptions. This work investigates these issues in relation to the analysis of the 3-point correlation function (3PCF) in configuration space. We measure the 3PCF of 300 halo catalogs from theMinervasimulations covering a total volume of 1000h-3Gpc3. Each 3PCF measurement includesallpossible triangular configurations with sides between 20 and 130h-1Mpc. In the first place, we test different estimates of the covariance matrix, a crucial aspect of the analysis. We compare the covariance computed numerically from the limited but accurate benchmark simulations set to the one obtained from 10000 approximate halo catalogs generated with thePinocchiocode. We demonstrate that the two numerically-estimated covariance matrices largely match, confirming the validity of approximate methods based on Lagrangian Perturbation Theory for generating mocks suitable for covariance estimation. We also compare the numerical covariance with a theoretical prediction in the Gaussian approximation. We find a good match between the two for separations above 40h-1Mpc. We test the 3PCF tree-level model in Perturbation Theory. The model is adopted in a likelihood analysis aimed at the determination of bias parameters. We find that, for our sample of halos at redshift z=1, the tree-level model performs well for separationsr≥ 40hh-1Mpc. Results obtained with this scale cut are robust against different choices of covariance matrix. We compare to the analogous analysis of the halo bispectrum already presented in a previous publication, finding a remarkable agreement between the two statistics. We notice that such comparison relies, to the best of our knowledge for the first time, on a robust and consistent covariance estimate and on the inclusion of essentially all measurable configurations in Fourier as in configuration space. We then test different assumptions to build the model defining a robust combination of hypotheses that lead to unbiased parameter estimates. Our results confirm the importance of 3PCF, supplying a solid recipe for its inclusion in likelihood analyses. Moreover, it opens the path for further improvements, especially in modelling, to extract information from non-linear regimes.
Regularization of δ′ potential in general case of deformed space with minimal length
Authors: Samar M I , Tkachuk V M 
Published: September 2022

Abstract
In the general case of deformed Heisenberg algebra leading to the minimal length, we present a definition of the δ′(x) potential as a linear kernel of potential energy operator in momentum representation. We find exactly the energy level and corresponding eigenfunction for δ′(x) and δ(x) − δ′(x) potentials in deformed space with arbitrary function of deformation. The energy spectrum for different partial cases of deformation function is analysed.
Green synthesis and characterisation of rice water derived fluorescent carbon dots
Authors: P C Haripadmam , M M Nimisha 
Published: September 2022

Abstract
In this article, we report a facile green synthesis of carbon dots (C-dots) with excellent blue emission using only rice water as the source. The C-dots are synthesised at 200 °C by a simple calcination method. Furthermore, the structural and optical characterisation of the as-synthesised C-dots reveals their quality without any further chemical modification. These non-toxic C-dots have good water solubility and stability. The anti-oxidant ability of these C-dots makes them suitable material for fruit storage applications. Hence the C-dots synthesised in the present study is a promising optical material and suitable for fruit preservation applications.
Side lobe level reduction of metasurface transmit array
Authors: Kumar P Vinod , Ghosh Basudeb 
Published: September 2022

Abstract
This paper presents a study on the side-lobe level (SLL) reduction with transmission type metasurface (MTS) using the concept of non-uniform array technique and transmit array antenna. According to the non-uniform antenna array technique, the SLL can be controlled by controlling the amplitude and phase distribution simultaneously. Initially, transmit array concept is used to design the MTS. The radiation characteristics of the MTS antenna are analyzed by exciting with a rectangular patch antenna at a fixed feed position. The simulation results show a gain of 17.6 dB with SLL of −18.3 and −19 dB in ϕ = 0° and 90°-planes, respectively. Later, non-uniform array techniques are used to reduce the SLL by introducing various amplitude distribution functions on the MTS for a fixed focal distance. The MTS incorporates the amplitude tapering functions such as Kaiser, Hamming, Hanning, and Blackman distribution functions. The resulting SLLs are analyzed, and the achieved SLLs are far from the theoretical values. In order to further reduce and control the SLL, the Gaussian distribution function is used, which minimizes the SLL by optimizing the standard deviation(σ). A MTS with 16 × 16 unitcells is fabricated and measured with an optimized σ = 0.31. The measured SLL are −25.1 and −26.3 dB in ϕ = 0° and 90°-planes, respectively.