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Assuming linear theory, the two dimensional problem of water wave scattering past thick rectangular barrier in presence of thin ice cover, is investigated here. Mainly four types of thick barriers are considered here and also the ice cover is taken as a thin elastic plate. May be the barrier is partially immersed or bottom standing or fully submerged in water or in the form of thick rectangular wall with a submerged gap presence in water. The problem is formulated in terms of a first kind integral equation by considering the symmetric and antisymmetric parts of velocity potential function. The integral equation is solved by using multi term Galerkin approximation method involving ultraspherical Gegenbauer polynomials as its basis function. The numerical solutions of reflection and transmission coefficients are obtained for different parametric values and these are seen to satisfy the energy identity. These coefficients are depicted graphically against the wave number in a number of figures. Some figures available in the literature drawn by using different mathematical methods as well as laboratory experiments are also recovered following the present analysis without the presence of ice cover, thereby confirming the correctness of the results presented here. It is also observed that the reflection and transmission coefficients depend significantly on the width of the barriers.

The emergence of new types of composite materials, the depletion of existing hydrocarbon deposits, and the increase in the speed of trains require the development of new research methods based on wave scattering. Therefore, it is necessary to determine the laws of wave scattering in inhomogeneous media. We propose a method that combines the advantages of a numerical simulation with an analytical study of the boundary value problem of elastic and acoustic wave equations. In this letter we present the results of the study using the proposed method: the formation of a response from a shear wave in an acoustic medium and the formation of shear waves when a vertically incident longitudinal wave is scattered by a vertical gas-filled fracture. We have obtained a number of analytical expressions characterising the scattering of these wave types.

We proposed and fabricated toroidal dipole (TD) metasurfaces(MSs) with a metamolecule of two coplanar U-shaped split ring resonators(USRRs) fabricated on polyimide substrate, and TD metamaterials (MMs) were the stacks of two TD MSs layers, whose frequencies, electromagnetic (EM) distributions and Q factor can be efficiently affected by the EM coupling effect in TD MSs/MMs. It was found that the resonances frequencies of TD MMs were shifted to lower frequencies due to the increase of inductance by the stacks of metallic layer. Meanwhile, the high-frequency TD resonance in TD MMs would be tailored by the periodicity. Considering the relation between TD resonances and the scattering power of TD (Ty), the Q factor depended highly on the value of Ty in the same metamolecule structure. The optimization in excitation of TD provide opportunity to further increase the Q-factor of metamaterial and pave a way for potential applications in terahertz sensor and other functional devices.

A broad tunability of the thermoelectric and mechanical properties of CoSb3 has been demonstrated by adjusting the composition with the addition of an increasing number of elements. However, such a strategy may negatively impact processing repeatability and composition control. In this work, single-element-filled skutterudite is engineered to have high thermoelectric and mechanical performances. Increased Yb filling fraction is found to increase phonon scattering, whereas cryogenic grinding contributes additional microstructural scattering. A peak zT of 1.55 and an average zT of about 1.09, which is comparable to the reported results of multiple-filled SKDs, are realized by the combination of simple composition and microstructure engineering. Furthermore, the mechanical properties of Yb single-filled CoSb3 skutterudite are improved by manipulation of the microstructure through cryogenic grinding. These findings highlight the realistic prospect of producing high-performance thermoelectric materials with reduced compositional complexity. Keywords: Skutterudites, Thermoelectric material, Compositional complexity, Microstructure engineering, Cryogenic grinding

Self-assembled block copolymer (BCP) thin films necessarily require a distinct chemical contrast between the blocks (or microdomain homogeneity) for the purpose of high-resolution pattern transfer applications. Despite its importance, however, there has been difficulty in measuring the chemical distribution associated with the self-assembling processes, i.e. solvent vapor annealing (SVA) or thermal annealing (TA). Herein, we present a simple yet effective method to probe the chemical distribution over polystyrene-b-poly(methyl methacrylate) (PS-b-PMMA) films that underwent the SVA or SVA + TA processes. An IR nanospectroscopy using scattering-type scanning near-field optical microscopy (s-SNOM), in concert with X-ray scattering analyses, provides the relative chemical concentration of the perpendicular lamellar patterns. The chemical mapping for the components based on the s-SNOM reveals that the SVA process leaves a considerable portion of the intermixed zones of PS and PMMA blocks, whereas the subsequent TA process facilitates the chain segregation towards high-contrast chemical distribution. Interestingly, such a microdomain homogeneity critically affects the quality of the unidirectional Al2O3 lines that were substituted from topographically guided lamellae. Our results substantiate an important insight into understanding the chain redistribution behavior in the self-assembled BCP films using non-destructive s-SNOM technique.

In this paper, a class of one-dimensional (1D) Fibonacci quasi-periodic multilayers composed of two parity-time-symmetric ( PT -symmetric) elements are designed. Their scattering spectra, transparencies, invisibilities, and other singular optical properties are investigated in detail. It is found that three types of new systematic phases, ten types of new unidirectional transparencies, two types of new bidirectional transparencies and one type of new bidirectional invisibility are created by this class of interesting systems, which possess more types compared with the PT -symmetric periodic multilayers and the Thue–Morse multilayers composed of PT -symmetric elements. It can be seen that although the order degree of the Fibonacci multilayers is lower than that of the other two systems, their types of systematic phases, transparencies, and invisibilities are obtained, their types of systematic phases, transparencies, and invisibilities are more abundant. This proves that, as the order degree of the PT -symmetric system decreases, its types of singular optical properties become more abundant. This work sheds some light on the PT -symmetric optical structures and Fibonacci sequence, offering the possibility to widen their application field. Moreover, it provides a theoretical basis to design new optical devices.

The selection of the type of the structured beam is great importance in the study of optical and first-order rainbow scattering by a particle. The Airy light-sheet is a specific type of limited-diffracting beam (in 2D), which has been used in investigations related to radiation forces and torque. Equally important and of practical significance is the study of the electromagnetic/optical resonance and first-order rainbow scattering by a dielectric sphere. The purpose of this paper is to calculate the electromagnetic resonance scattering, energy efficiencies and far-field scattered intensity of a lossless homogeneous dielectric spherical particle of arbitrary size, illuminated by a linearly-polarized non-diffracting electromagnetic Airy light-sheet. A rigorous parametric study is undertaken here to investigate the effect of varying the light-sheet parameters γ , k w 0 , and its polarization state as well as the size parameter k a of the lossless dielectric sphere on the scattering efficiencies and intensity. The analysis is extended to examine the first-order rainbow scattering phenomenon in the context of Airy light-sheets with different polarizations. Numerical results show that k w 0 , γ , k a and the state of polarization affect the amplitude and scattering directivity patterns of the efficiencies and intensity. Rainbow scattering arises along the polar scattering angle θ = 143 ° , and is minimally influenced by the different values of the parameters k w 0 , γ , polarization, and k a . The results are of some practical significance in optical resonance scattering and related applications in optical tweezers, super-resolution imaging, particle characterization, and the measurement of temperature, velocity and size of a liquid jet to name a few applications.

The classification of the type of trapped particles is a crucial task for an efficient integration of optical-tweezers in intelligent microfluidic devices. In the recent years, the use of the temporal scattering signal of the trapped particle paved for the use of versatile optical fiber solutions for performing such tasks, a feature previously unavailable as most methods required conventional optical tweezer setups. This work presents a comprehensive comparison of performances achieved with two distinct implementations – i)optical fiber and ii)conventional optical tweezers – for the classification of the material of particles through the analysis of the scattering signal with machine learning algorithms. The results suggest that while micron-sized particles can be accurately classified using the forward scattering information in conventional optical tweezers, when equipped with a quadrant photodetector, the optical fiber tweezers solutions can easily surpass its performance using the back-scattered information if the laser is modulated. Together with the advantages of being simpler, less expensive and more versatile, the results presented suggest that optical fiber solutions can become a valuable tool for miniaturization and integration of intelligent microfluidic devices working towards nanoscopic scales.

Relaxation mechanisms of shake gels (particle-polymer systems) are not yet fully understood, mainly because of the lack of effective structural parameters to describe relaxation processes. Small-angle X-ray scattering and dynamic light scattering methods were employed to track the relaxation processes in a water-based shake gel system, composed of 20 wt % of 24.8 nm silica nanoparticles and 0.3 wt % of poly(ethylene oxide) (PEO1000k). The gelation of the studied silica-PEO dispersion was readily induced by quick manual shaking (∼3 cycles/s). Temporal structural evolution of the shake gel after manual agitation was inferred from the development of the modeled parameters. The quantitative structural parameters extracted from the scattering data, i.e. nearest neighbor distance of silica nanoparticles and floc size of gel network, showed that the shake gel network quickly relaxes during the first 10–20 min following the shake-induced gelation, and then slowly reaches a quiescent structure after 1 h.

In this work we consider the scalar field model with a false vacuum proposed by Avelar et al. (2008) [27]. The model depends on a parameter s>0. The model has unstable nontopological lump solutions with a bell shape for small s, acquiring a flat plateau around the maximum for large s. For s→∞ the ϕ4 model is recovered. We show that for s≳2 the lump is metastable with the only negative mode very close to zero. Metastable lumps can propagate and survive long enough to produce dynamical effects. Due to their simplicity, they can be an alternative to the procedure of stabilization which requires, for instance, a complex scalar field to construct nontopological solitons. We study lump-lump collisions in this model, describing the main characteristics of the scattering products at their dependence on s and the initial velocity modulus of each lump.

The atomic structure of pure and defective graphite has been modelled using classical many body potentials from which simulated powder X-ray Diffraction (XRD) patterns were produced using the Debyer software. The changes in the XRD patterns due to both heating and the inclusion of defects were investigated. After heating, the results show a shift in the 004 Laue peak in qualitative agreement with experiment. The c parameter is shown to increase over the temperature range 0 – 1000 K but there is a slight reduction in the a parameter over this range. The scattering angle for the 004 peak reduces with the introduction of defects up to ≈ 5 % defect concentration for both vacancies and interstitials with a larger reduction in the case of interstitials. The intensity of the scattering peak is reduced with increasing interstitials (25% reduction at 5% concentration), but remains relatively constant with increasing vacancies. The introduction of a small percentage of interstitials causes an increase in both the a and c parameters but vacancies cause a reduction in the a parameter.

Differential, integral, momentum-transfer, viscosity, inelastic and total cross sections as well as spin asymmetries are calculated for electron and positron scattering from the gold atom with nuclear spin 3 2 . The impact energies of the projectiles range from low-energy atomic physics regime to high-energy nuclear physics. This is accomplished by employing two different theoretical approaches, applicable for the aforesaid two domains of energies, and are based on the partial-wave analysis. In one approach, the phase shifts analysis is done at E i 1 MeV using the Dirac relativistic equations. In another approach, at E i ≥ 100 keV, the same analysis is carried out with the distorted wave Born approximation to account for the projectile scattering including the magnetic effect as well. Predictions are reported for 1 eV ≤ E i ≤ 0.5 GeV electrons and positrons colliding with 197 Au target. In addition, we report here systematically the details of the critical minima in the elastic differential cross sections. To date, neither any experimental nor any theoretical study on the critical minima of electron/positron–Au scattering system is available in the literature. Our results of other observables are compared with the available experimental data and other calculations and are found to produce quite reasonable agreements with two forms of data.

Color charge correlators provide fundamental information about the proton structure. In this Letter, we evaluate numerically two-point color charge correlations in a proton on the light cone including the next-to-leading order corrections due to emission or exchange of a perturbative gluon. The non-perturbative valence quark structure of the proton is modelled in a way consistent with high-$x$ proton structure data. Our results show that the correlator exhibits startlingly non-trivial behavior at large momentum transfer or central impact parameters, and that the color charge correlation depends not only on the impact parameter but also on the relative transverse momentum of the two gluon probes and their relative angle. Furthermore, from the two-point color charge correlator, we compute the dipole scattering amplitude. Its azimuthal dependence differs significantly from a impact parameter dependent McLerran-Venugopalan model based on geometry. Our results also provide initial conditions for Balitsky-Kovchegov evolution of the dipole scattering amplitude. These initial conditions depend not only on the impact parameter and dipole size vectors, but also on their relative angle and on the light-cone momentum fraction $x$ in the target., Comment: 11 pages, 10 figures, v3: published version

We reexamine the inverse Primakoff scattering of axions, whose scattering cross section depends on the distribution of electrons in target atoms. We evaluate it using a form factor computed with a relativistic Hartree-Fock wave function and compare it with the previous results obtained with those based on the screened Coulomb potential for the electrostatic field in the atom. We take xenon as an example for the target atom and show that the scattering cross section was overestimated by more than an order of magnitude for axions with $\lesssim O(10)$ keV energies, like solar axions. It is also found that inelastic scattering processes, in which the final state contains an excited or ionized atom, can be comparable or even be dominant when the size of momentum transfer is $\lesssim 1$ keV. For more energetic axions, on the other hand, the total scattering cross section is found to be well approximated by a simple expression and has little dependence on the atomic structure. As an application of this result, we consider supernova axions, whose energy is 10-100 MeV, and show that $O(1)$ inverse Primakoff events are expected for axions from a nearby supernova in the future neutrino experiments, which may warrant a more detailed study on the search strategy of this process., Comment: 15 pages, 3 figures; published version

Recently, the XENON1T experiment has reported the possible detection of an excess in the electronic recoil spectrum. Such an excess may indicate the presence of new physics. In this work, we suggest that the scattering of mirror electrons with ordinary electrons through photon$-$mirror photon kinetic mixing with parameter $\epsilon \sim 10^{-12}(n_{\rm e'}/0.2{\rm cm^{-3}})^{-1/2}({v_{\rm c}^0/5\times 10^{9}~{\rm cm~s^{-1}}})^{1/2}$ may account for the excess electronic recoil events in XENON1T, where $n_{\rm e'}$ is the density of mirror electron and $v_{\rm c}^0$ is the cutoff velocity of the mirror electron arriving at the earth. Interestingly, this parameter to interpret the excess of XENON1T electronic recoil spectrum are consistent with the constrains of Darkside50., Comment: 5 pages, 3 figures

Using dispersion theory with an improved description of the two-pion continuum based on the precise Roy-Steiner analysis of pion-nucleon scattering, we analyze recent data from electron-proton scattering. This allows for a high-precision determination of the electric and magnetic radius of the proton, $r_E = (0.838^{+0.005}_{-0.004}{}^{+0.004}_{-0.003})\,$fm and $r_M = (0.847\pm{0.004}\pm{0.004})\,$fm, where the first error refers to the fitting procedure using bootstrap and the data while the second one refers to the systematic uncertainty related to the underlying spectral functions., Comment: 8 pages, 2 figures, more discussions and references added, version accepted for publication in Physics Letters B

The inconsistent interfacial bonding of 3D-printed materials is accompanied by increasing scattering of the measured fracture toughness in delamination tests. This article focuses on the analysis of the delamination tests using theories developed for conventional composites. To this end, nylon 3D-printed specimens reinforced with carbon fibers are subjected to the mode I Double Cantilever Beam (DCB) and the mode II End-Loaded Split (ELS) tests. Several analytical methods and numerical models are employed to measure the fracture toughness and simulate the behavior of the specimen during delamination. The uncertainty of the data is considered by expanding the deterministic character of the models utilizing the non-intrusive stochastic pseudo-spectral projection method. The results of the simulations are well in agreement with the experimental results and support the use of stochastic techniques in combination with linear fracture mechanics for the delamination analysis of 3D-printed composites.

International audience; This study focuses on the role played by the interparticle and interlayer porosities, and the preferred orientation of the particles on water diffusion in dual-porosity clayey media (i.e., swelling clay minerals). For this purpose, we use Na-vermiculite, a swelling clay that does not exhibit osmotic swelling and therefore allows a clear discrimination between the interparticle and interlayer porosities. Two samples were prepared with an equal proportion of interparticle and interlayer porosities (i.e., 0.25 each) but different degree of preferred particle orientation (i.e., isotropic vs anisotropic). Through-diffusion and pulsed gradient spin echo attenuation measurements by nuclear magnetic resonance of protons techniques were used to probe water mobility, while the orientation of the particles was quantified by X-ray scattering analysis. Experimental water diffusion results obtained with these two Na-vermiculite samples were compared to those with samples made of Na-kaolinite particles (non-swelling clay mineral) having only interparticle porosities equal to 0.25 and 0.5, corresponding respectively to the interparticle and the total porosity of the Na-vermiculite samples. In addition, these experimental results were compared to simulated data using Brownian dynamics with virtual porous media representative of the real samples. For the range of porosities investigated, a good agreement was observed between measured and simulated water mobilities. The obtained results confirmed the important role played by the preferential orientation of the particles on water dynamics in clayey media, through an important reduction of overall water mobility between the isotropic and anisotropic Na-vermiculite samples. These results also showed that for the same total porosity, the presence of interlayer porosity and associated nano-confinement led to a logical reduction in the pore diffusion coefficient of water in Na-vermiculite in comparison to Na-kaolinite. Moreover, in comparison with Na-kaolinite having the same interparticle porosity, results showed that the contribution of the interlayer volume on the traversing flux was small compared to the interparticle volume. Finally, the computed results revealed that the anisotropy in water diffusion can be directly predicted based on the degree of particles preferred orientation, irrespective of the total or the distribution of the different porosity types.

A state-of-the-art encapsulation technique for evaluating a photovoltaic device in laboratory is needed for replicating real-time devices. In this context, earlier we proposed the pouch lamination as a cost-effective and reproducible lab-scale encapsulation technique. In this work, we apply this technique in evaluating the optical and electrical performances of a mc-Si device with a front spectral shifting layer before and after encpasulation. Our coating contains the red-emitting nitride phosphor CaAlSiN3:Eu2+ (CASN:Eu2+) in (poly)-methyl methacrylate (PMMA). On coating, a drastic reduction in the device's reflectance was observed below 450 nm. Correspondingly, the external and internal quantum efficiencies of the devices are also improved relative to the bare. When irradiated by an AM1.5G source, the electrical parameters remain of the device remain unaffectd after the coating. However, on encapsulating the coated device, impedance losses drastically reduce its conversion efficiency. This paper thus reveals the need for including an encapsulant while demonstrating device modifications through optical coatings.

Polarimetric decomposition models such as Freeman-Durden’s three-component and Yamaguchi’s four-component models were used to extract the scattering mechanisms. In a few cases, both the models have shown overestimation of the volume scattering from the highly-dense building instead of even-bounce scattering. Deorientation process helped to reduce the overestimation of the volume scattering but didn’t accomplish completely. This paper addressed this issue by the insertion of PolInSAR coherence in the existing decomposition models. The coherence varies with features based on its temporal and volume decorrelation, hence forest results in low coherence compared to permanent scatterers helps to characterize the man-made and natural features. This paper experimented with a proposed model on the RADARSAT-2 dataset of Uttarakhand as a case study. Volume scattering was modified and extracted based on different coherence parameter assumptions. Finally, the first optimal band with spatial and temporal baseline coefficients as 1 and 0.6 thresholds gave a more reliable outcome. For qualitative analysis, the scattering mechanisms of features from different models were compared. In the proposed model, closely spaced buildings exhibited 54% and 26% dominance in the even and odd-bounce scattering while volume scattering reduced to 18%. Whereas Freeman-Durden and Yamaguchi’s model has shown dominance in volume nearly 98% and 50% while even and odd-bounce scattering were less than 1% in Freeman-Durden model and 39% and 11% in Yamaguchi’s model. Forest shows dominance in the volume scattering higher than 60% in the Freeman-Durden and the proposed models whereas 35% in the Yamaguchi’s model. Therefore, the proposed methodology successfully fused polarimetry and interferometry to overcome the ambiguity in scattering.

The substrate effects on the electronic transport properties of single-layer graphene on TiO2/Si substrate have been studied. The Hall mobility, sheet carrier density, and transport lifetime were obtained from the temperature-dependent Hall measurements, while the in-plane effective mass, quantum lifetime was obtained from the temperature-dependent variation of the Shubnikov de Haas (SdH) oscillations that were made at 1.8 to 45 K temperature range and up to the magnetic field of 11 T. The measurement results showed that in SLG/TiO2/Si sample, there were 2.36 ± 0.12x1016 m-3 amounts of 3D carriers coming from the substrate. In our previous studies, 3D carrier densities were measured as 6.07x1016 m-3 and zero for SLG/SiO2/Si and SLG/SiC sample, respectively. This result shows that the 3D carriers formed in the structure are significantly changed by a substrate. The scattering mechanisms were determined using the τ t / τ q ratio. The ratio values obtained as 3.66. This value obtained was compared with the values we found for SLG/SiC ( τ t / τ q =1.36) sample and SLG/TiO2/Si ( τ t / τ q =3.08) sample our previous study. The results show that small-angle scattering is dominant in SLG/SiC sample, but large-angle scattering is dominant in SLG/SiO2/Si and SLG/TiO2/Si samples. The charged impurity scattering is the dominant scattering mechanism in SLG/TiO2/Si and SLG/SiO2/Si samples, whereas in SLG/SiC samples, a short-range scattering mechanism such as lattice defects can be said to affect the electronic transport.

We perform the first consistent calculation of elastic-scattering and inelastic-scattering structure functions for spin-dependent WIMP-nucleus scattering for 183W in a microscopic nuclear-theory framework. The nuclear structure calculations are performed in the microscopic interacting boson-fermion model (IBFM-2). Our results show that while 183W is very insensitive to spin-dependent elastic scattering, the structure function for inelastic scattering is quite sizable at small momentum transfers. Moreover, to our knowledge 183W provides the first studied case where inelastic scattering can compete with elastic scattering as the primary detection signal. peerReviewed

We comment on phase selection of the scattering amplitude, emphasizing that the elastic overlap function should have a central impact parameter profile at high energies and highlighting the role of the reflective scattering mode at the LHC energies. Emerging problems with the use of peripheral impact parameter dependence of the elastic overlap function are explicitly indicated. Their solution is an elimination of the phases connected to peripheral form of the elastic overlap function. Contrary, we adhere to a relative peripheral form of the {\it inelastic} overlap function with an additional new feature of a maximum at nonzero value of the impact parameter at the highest energies. Phenomenologically, the dynamics of hadron scattering is motivated by a hadron structure with a hard central core presence., Comment: 13 pages, 2 figures, revised version

Summary Controllable IR-reflection systems can be applied to displays, adaptive military camouflages, thermal managements, and many other fields. However, current reported controllable IR-reflection systems suffer from utilizing rigid materials, complicated devices, or high working temperature/voltage, which are not suitable for their widespread applications toward soft systems. Herein, inspired by cephalopods, we demonstrate a facile and scalable method for adaptive IR reflection based on a Janus rubber film, which is composed of aluminum-coated microsheets (AMSs)/rubber composite top and a rubber only bottom. Expansion of the Janus rubber film causes random arrangement of AMSs to stay planar, resulting in the change from IR scattering to concentrated IR reflection. By fixing the Janus rubber films upon the arranged tubes, as-prepared arrays could display complex and changeable patterns by selectively pumping tubes. Being facile and of general validity, our strategies broaden the scope of future controllable IR reflecting applications for environmental IR camouflages and displays., Graphical abstract, Highlights • The IR reflection can be tuned by the expansion/recovery of the Janus rubber film. • A pixilated device can adaptively IR camouflage/display through selected blowing. • The assembled tube arrays exhibit fast response and can be scalable manufactured., Materials Science ; Materials Chemistry ; Materials Synthesis ; Biomaterials

We study the newly reported hidden-charm pentaquark candidates $P_c(4312)$, $P_c(4440)$ and $P_c(4457)$ from the LHCb Collaboration, in the framework of the effective-range expansion and resonance compositeness relations. The scattering lengths and effective ranges from the $S$-wave $\Sigma_c\bar{D}$ and $\Sigma_c\bar{D}^*$ scattering are calculated by using the experimental results of the masses and widths of the $P_c(4312)$, $P_c(4440)$ and $P_c(4457)$. Then we calculate the couplings between the $J/\psi p,\,\Sigma_c\bar{D}$ channels and the pentaquark candidate $P_c(4312)$, with which we further estimate the probabilities of finding the $J/\psi p$ and $\Sigma_c\bar{D}$ components inside $P_c(4312)$. The partial decay widths and compositeness coefficients are calculated for the $P_c(4440)$ and $P_c(4457)$ states by including the $J/\psi p$ and $\Sigma_c\bar{D}^*$ channels. Similar studies are also carried out for the three $P_c$ states by including the $\Lambda_c\bar{D}^{*}$ and $\Sigma_c\bar{D}^{(*)}$ channels., Comment: 11 pages, 4 tables. To match the published version in Phys.Lett.B

The scattering of fast charged particles in a thin crystalline undulator is considered under conditions when all particles of the beam undergo above-barrier motion with respect to the bent crystalline atomic planes. The consideration is based on the analysis of the particles motion in the continuous potential field of the bent crystal atomic planes and on the simulation of the scattering process taking into account the influence of incoherent effects in scattering on the particles motion. The possibility of manifestation of the effect of multiple volume reflection from bent crystalline atomic planes both for positively and negatively charged particles is shown. The possibility of the beam profiles significant change by means of a small size crystalline undulator is demonstrated., Comment: 6 pages, 8 figures

The impact of the Marangoni convection over the thin film flow on an expanding cylinder has been examined in this study. The diverse effect of the embedded constraints has been detected during the liquid film flow. It has been examined that the behavior of the physical parameters altered after the small intervals and diverse from the traditional approach. The similarity variables have been utilized to alter the basic flow equations into the nonlinear ordinary differential equations. The result of the transformed equations is computed by BVPh 2.0 package. The performance of different constraints, for flow motion and temperature distributions are plotted and conferred. It has been observed that under the Marangoni convection the impact of the physical parameters varies after the point of inflection and the diverse impact of the embedding constraints provide space for the variation of the point of inflection for the desired spray analysis. Keywords: Marangoni convection, Steady flow, Thin film spray, Stretching cylinder, OHAM

Sophisticated high-energy and large momentum-transfer scattering experiments combined with ab-initio calculations can reveal the short-distance behavior of nucleon pairs in nuclei. On an opposite energy and resolution scale, elastic electron scattering experiments are used to extract the charge density and charge radius of different nuclei. We show that even though the charge density has no obvious connection with nuclear short-range correlations, it can be used to extract properties of such correlations. This is accomplished by using the nuclear contact formalism to derive a relation between the charge density and the proton–proton nuclear contacts that describe the probability of two protons being at close proximity. With this relation, the values of the proton–proton contacts are extracted for various nuclei using only the nuclear charge density and a solution of the two-nucleon Schroedinger equation as inputs. For symmetric nuclei, the proton–neutron contacts can also be extracted from the charge density. Good agreement is obtained with previous extractions of the nuclear contacts. These results imply that one can predict (with reasonably good accuracy) the results of high-energy and large momentum-transfer electron-scattering experiments and ab-initio calculations of high momentum tails using only experimental data of elastic scattering experiments. Keywords: Short range correlations, Contact formalism, Charge density

In order to elucidate the cell performance related to swelling or flooding of the polymer electrolyte membrane (Nafion®), we performed in-situ measurements of small-angle neutron scattering (SANS) and neutron radiography (NR) for a polymer electrolyte fuel cell (PEFC) during electricity generation. SANS determined the swelling behavior by observing inter-particle scattering of water-clusters and mean inter-distance of nm order (Lw). With increased current density, Lw heterogeneously increases along the serpentine-shaped gas channel. NR revealed that flooding occurs along the channel after reaching Lw to the maximum. Lw determined by SANS was converted to the number of water molecules (λw) hydrating around a sulfonic group. Using this key value, we evaluated the membrane resistance Rm. To determine the local cell performance, corresponding to SANS & NR observations, we developed a segmented electrode cell combining electrochemical impedance spectroscopy. The segmented electrode independently determined the membrane resistance and I-V curve were determined for the local area, which is sensitive to the heterogeneous swelling along a film thickness. As a result of comparison with SANS and the results by segmented electrode, we found heterogeneous swelling along the gas flow path or along a thickness direction. The heterogeneity changes as the current increases. By comparing with NR, we found that flooding appears after swelling of the membrane is saturated. Keywords: Polymer electrolyte fuel cell, Small-angle neutron scattering, Segmented electrode cell

We investigate the quasi-integrability properties of various deformations of the Korteweg–de Vries (KdV) equation, depending on two parameters ε1 and ε2, which include among them the regularized long-wave (RLW) and modified regularized long-wave (mRLW) equations. We show, using analytical and numerical methods, that the charges, constructed from a deformation of the zero curvature equation for the KdV equation, are asymptotically conserved for various values of the deformation parameters. By this we mean that, despite the fact that the charges do vary in time during the scattering of solitons, they return after the scattering to the same values they had before it. This property was tested numerically for the scattering of two and three solitons, and analytically for the scattering of two solitons in the mRLW theory (ε2=ε1=1). In addition we show that for any values of ε1 and ε2 the Hirota method leads to analytical one-soliton solutions of our deformed equation but for ε1≠1 such solutions have the dispersion relation which depends on the parameter ε1. We also discuss some properties of soliton-radiation interactions seen in some of our simulations.

In this paper we consider the solution of a black hole with a global monopole in $f(R)$ gravity and apply the partial wave approach to compute the differential scattering cross section and absorption cross section. We show that in the low-frequency limit and at small angles the contribution to the dominant term in the scattering/absorption cross section is modified by the presence of the global monopole and the gravity modification. In such limit, the absorption cross section shows to be proportional to the area of the event horizon., 11 pages, 3 figures, version to appear in PLB

Recently the concept of quasi parton distributions (quasi-PDFs) for hadrons has been proposed. Quasi-PDFs are defined through spatial correlation functions and as such can be computed numerically using quantum chromodynamics on a four-dimensional lattice. As the hadron momentum is increased, the quasi-PDFs converge to the corresponding standard PDFs that appear in factorization theorems for many high-energy scattering processes. Here we investigate this new concept in the case of generalized parton distributions (GPDs) by calculating the twist-2 vector GPDs in the scalar diquark spectator model. For infinite hadron momentum, the analytical results of the quasi-GPDs agree with those of the standard GPDs. Our main focus is to examine how well the quasi-GPDs agree with the standard GPDs for finite hadron momenta. We also study the sensitivity of the results on the parameters of the model. In general, our model calculation suggests that quasi-GPDs could be a viable tool for getting information about standard GPDs., Comment: 14 pages; version to be published in PLB

The data presented in this article are related to the research article entitled "Effect of collagen packing and moisture content on leather stiffness" (Kelly et al., 2018). This article describes how moisture content affects collagen packing and leather stiffness. Structural changes were experimentally introduced into ovine leather through biaxial strain during tanning (׳stretch tanning׳). Leather samples produced normally without strain (׳non-stretch tanned׳) and those produced by stretch tanning, were conditioned in a range of relative humidity environments and then analysed by small angle X-ray scattering and three point bend testing. The collagen D-spacing, lateral intermolecular spacing and flexural properties were measured under these varying moisture contents.

Semiconductor detectors with Silicon as the sensor material are widely used in High Energy Physics (HEP) experiments for high precision tracking and determination of primary and secondary vertices with good spatial resolution. They are close to the interaction point, so they are prone radiation damage due to the high fluence of produced particles. The choice of semiconductor material is based on the signal to noise ratio, multiple scattering, pulse timing and radiation hardness. In this paper, we compare the suitability of Silicon (Si), Germanium (Ge), Gallium Nitride (GaN), and Diamond for high energy and high luminosity experiments. In addition, we also show the results on the growth of diamond films and their characterizations. Keywords: MPCVD, Radiation hardness, Luminosity, Occupancy

The effects of pulsed laser processing (PLP) with different laser power (PL = 10, 20 and 30 W) on the surface morphology, structure and properties of Fe78Si9B13 amorphous ribbon were investigated. It was found that the circular blobs, convex in perimeter and sunk in middle, distributed regularly on the surface of ribbon after PLP with PL = 10 W. As PL increased to 20 and 30 W, obvious splashes occurred around the laser blobs. On the surface of ribbons after PLP, fresh amorphous structures were generated, which were confirmed by small angle X-ray scattering and transmission electron microscope data. Meanwhile, a small number of nanocrystallines formed at heat affected zone. The X-ray diffraction results indicated that the transformation from fcc to bcc SRO structure units occurred during PLP, resulting in a lower characteristic distance δC. The pitting resistance, soft magnetic property and thermal stability of ribbons were enhanced after PLP. Especially, the properties had a significant improvement with increasing PL from 10 to 20 W, but had a slight deterioration as PL increased further from 20 to 30 W. Overall, an optimal laser power of 20 W was obtained for PLP of Fe78Si9B13 amorphous ribbon in this work. Keywords: Fe-based amorphous ribbon, Pulsed laser processing, Structural transformation, Magnetic property, Pitting resistance, Thermal stability

This paper considers an accurate and efficient numerical scheme for solving the radiative transfer equation (RTE) based on the discrete ordinates method (DOM) in highly forward-peaked scattering media. The DOM approximates the scattering integral of the RTE including the phase function into a quadrature sum with the total number of discrete angular directions (TND) by a quadrature set. Due to large numerical errors of the scattering integral based on the DOM in highly forward-peaked scattering, the phase function is renormalized to satisfy its normalization conditions. Although the renormalization approaches of the phase function improve the accuracy of the numerical results of the RTE, the computational efficiency of the RTE is still required. This paper develops the first order renormalization approach using the double exponential formula for three quadrature sets: level symmetric even, even and odd, and Lebedev sets in a wide range of the TND from 48 to 1454. Numerical errors of the three-dimensional time-dependent RTE are investigated by the analytical solutions of the RTE. The investigation shows that the level symmetric even set with the TND of 48 using the developed approach provides the most accurate results of the RTE among the quadrature sets in the range of the TND, while to obtain the same accuracy by the conventional zeroth order renormalization approach, the TND needs to be larger than 360. The results suggest the large reduction of computational loads by the developed approach to less than 10 percent from those in the conventional approach.

Optical phonon scattering mobility has been calculated using numerical methods, and a general program was developed in Matlab to calculate mobility due to scattering on optical phonons. Calculations were done for InAs material that was irradiated by fast neutrons.

We investigate the semiclassical electronic transport properties of the bilayer silicene-like systems in the presence of charged impurity. The trigonal warping due to the interlayer hopping, and its effect to the band structure of bilayer silicene is discussed. Besides the trigonal warping, the external field also gives rise to the anisotropic effect of the mobility (at finite temperature) which can be explored by the Boltzmann theory. The dynamical polarization as well as the scattering wave vector-dependent screening within random phase approximation are very important in determining the scattering behavior as well as the self-consistent transport. We detailedly discuss the transport behavior under the short- or long-range potential. The phonon scattering with the acoustic phonon mode which dominants at high temperature is also studied within the density functional theory (DFT). Our results are also valid for the bilayer graphene or bilayer MoS2, and other bilayer systems which with strong interlayer coupling. Keywords: Bilayer silicene, Relaxation rate, Dynamical polarization, Phonon scattering, Charged impurity, Boltzmann transport

An attempt is made to present the influence of the scalar unparticle on some scattering processes in the Randall–Sundum model. The contribution of the scalar unparticle on the production of Higgs–radion at high energy colliders is studied in detail. We evaluate the production cross-sections in the electron–positron (e+e−), photon–photon (γγ) and gluon–gluon (gg) collisions, which depend strongly on the collision energy s, the scaling dimension dU of the unparticle operator OU and the energy scale ΛU. Numerical evaluation shows that the cross-sections for the pair production of scalar particles are much larger than that of the associated production of the scalar particle with unparticle under the same conditions.

Modification of the photon dispersion relation in chiral matter enables $1\to 2$ scattering. As a result, the single fermion and photon states are unstable to photon radiation and pair production respectively. In particular, a fast fermion moving through chiral matter can spontaneously radiate a photon, while a photon can spontaneously radiate a fast fermion and anti-fermion pair. The corresponding spectra are derived in the ultra-relativistic approximation. It is shown that the polarization of the produced and decayed photons is determined by the sign of the chiral conductivity. Impact of a flat thin domain wall on the spectra is computed., 13 pages. v2: error in IVA corrected, explanations and references added, typos fixed

Motivated by the recent result of XENON1T collaboration with full exposure, 279 life days, that sets the most stringent limit on the spin-independent dark matter-nucleon scattering cross section we discuss a dark $E_6$-inspired model that features the presence of a $U(1)_{d-u}$ gauge symmetry. The dark matter candidate is a Dirac fermion that interacts with Standard Model fermions via a massive Z' that preserves the quantum number assignments of this symmetry. We compute the spin-independent scattering cross section off xenon nucleus and compare with the XENON1T limit; find the LHC bound on the Z' mass as well as the projection sensitivity of high-energy and luminosity LHC; and derive the Fermi-LAT bounds on the dark matter annihilation cross section based on the observation of gamma-rays in the direction of Dwarf Spheroidal galaxies. We exploit the complementarity between these datasets to conclude that the new bound from XENON1T severely constrain the model, which combined with the LHC upgrade sensitivity rules out this WIMP realization setup below 5 TeV., Comment: 7 pages, 3 figures

The analysis of sound scattered by a rough surface and measured by multiple microphones positioned in the far field yields an estimate of the unknown scattering surface profile. Expanding from previous work, the approach used in this paper is based on an expansion and linearization of the Kirchhoff integral equation, and applies to a low density of receivers. Here, the original algorithm is modified in order to reduce the measurement bias, and extended to broadband signals to over-constrain the problem and improve its robustness. The improved method is rigorously assessed alongside the original algorithm and its small perturbation version, for a two-dimensional geometry and for scattering surfaces with a spatial power-function spectrum. The impact of the measurement setup and surface characteristics on the reconstruction uncertainty are evaluated by means of numerical simulations. Additional experimental data obtained for three known surface profiles reveal the impact of noise and measurement uncertainties. The optimal measurement configuration requires a trade-off between resolution (higher at high frequencies), and robustness (higher at low frequencies). This limit is overcome at least partially by the proposed multiple-frequency extension. The resulting measured uncertainties were close to the theoretical expectation of approximately 2% of the acoustic wavelength.

Planar temperature images using laser Rayleigh scattering have been obtained to determine the spatial distribution of temperature in a constant volume combustion chamber. Burning velocities were also measured from measured pressures and calculated flame surface area from Rayleigh scattering images. A high power KrF excimer laser was used as a light source and a high gain ICCD camera was used to obtain temperature images. Methane/air premixed combustion at different equivalence ratios and initial pressures were tested. Since the thermodynamics are well known, a constant volume chamber can be used as a reference device for diagnostics in high temperatures and pressures combustion. With the Rayleigh scattering technique, temperature and burning velocity can be measured simultaneously using a single-shot laser light. An additional laser Rayleigh experiment is described which yields scattering cross sections at the wavelength of 248 nm. The experimental results show an excellent agreement with previous data.

Induced disorder in graphene enables changes in electrical and thermal transport. It has been shown previously that disorder is very important for electron cooling in graphene through disorder-assisted electron-phonon scattering, particularly via the supercollisions process. Here we study electron-momentum relaxation due to electron-phonon scattering while increasing the degree of disorder. With in-situ scanning thermal microscopy we monitor the temperature rise in the constriction region of a bowtie-shaped graphene device while increasing the disorder by means of feedback-controlled voltage ramps at high-current densities. Analysis of the combined thermal and electrical measurements in the low bias regime shows that the relative change of the momentum scattering rate vs temperature, as measured at room temperature, increases with strong local disorder. By excluding other candidate mechanisms for this phenomenon, including a change of the charge carriers density and activation of optical phonons, we conclude that the increase we observe in the temperature-dependent component of the scattering rate is likely due to new acoustic phonon scattering channels that open up as disorder increases.

Thermoelectric materials are capable of directly converting heat into electricity by the Seebeck effect, which are applicable to a wide range of industrial applications. For semiconductor thermoelectrics, one of the most effective ways to enhance their performance is to use nanostructures to significantly reduce their lattice thermal conductivity, which is governed by lattice vibrations referred to as phonons, without dramatically sacrificing their electrical properties. Hence, the transport of phonons in nanostructured thermoelectrics is of crucial importance. This chapter stresses the basic concepts and fundamental principles of the transport of phonons in nanostructured materials. Starting with the concepts of phonons and phonon Boltzmann transport equation, we can derive the phonon gas model for thermal conductivity. Various scattering mechanisms of phonons that affect the thermal conductivity in nanostructured materials, well-established theoretical and experimental methods used for the investigation of phonon transport, and examples in terms of manipulating phonons with nanostructures in the field of thermoelectrics are described.

In this chapter, scattering studies of nanocomposites of polyhedral oligomeric silsesquioxane (POSS) with various polymer types have been outlined. Scattering studies including dynamic light scattering (DLS), static light scattering (SLS), wide-angle X-ray scattering (WAXS), small-angle X-ray scattering (SAXS), small angle neutron scattering (SANS), and powder X-ray diffraction (XRD) were discussed. Scattering studies examine the structural behavior and dynamics of composites at the nanoscale in addition to the size of nanoparticles. Nanocomposites of POSS with various polymers including polyolefins, engineering plastics, thermosetting polymers, elastomers, and biopolymers available in recent research studies were focused on in this chapter.

X-ray and neutron scattering belong to principal tools in the investigation of structure and dynamics of materials. This chapter resumes information on structural aspects important on various length scales in natural rubber and its products revealed by various methods of X-ray and neutron scattering. Principles of scattering theory and scattering functions important for the analysis of the systems based on natural rubber are reviewed. Experimental determination of key structural parameters such as degree of crystallinity, polymer network mesh size, correlation lengths, fractal dimensions, and so on is also discussed. Results obtained from natural rubber that is uncrosslinked, crosslinked or filled by various types of nanofillers are compared and reviewed.