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Seeds from Cassia obtusifolia L., i.e. Semen cassiae (SC) were evaluated as environmentally friendly filler particles for artificial turf. The goal was to avoid unwanted germination problems of SC under wet conditions. This work evaluated the influence of different pretreatments on the germination rate and performance of SC. After the combination of polishing and dry heat (90 °C, 72 h) treatment, the germination rate of SC decreased to 0% and the activation energy increased to 216 kJ/mol. Compared with the untreated SC, the thermal stability of SC improved, with an initial degradation temperature of 214 °C and a pyrolysis residue of 31.9%. Additionally, the resilience and the water absorption of SC as a filler material increased to 4.13% and 169%, respectively. This study provides an effective pretreatment method for the solution of germination problem and the performance improvement of SC. This makes the pretreated SC a prospective candidate as an environmentally protective granular filling material. [ABSTRACT FROM AUTHOR]

We report numerical results of quantum oscillations of the specific heat in the vortex state of a dx²-y²-wave superconductor in the presence of loop current order [C. M. Varma, Phys. Rev. B 55, 14554 (1997); Phys. Rev. Lett. 83, 3538 (1999)], which gives rise to the Fermi pockets coexisting with nodal dx²-y²-wave superconductivity. Within a lattice tight-binding model, we find that in an intermediate temperature range, the oscillations seem to approximately follow the Onsager relation with an effective charge comparable to the electric charge. However, the quasiparticle spectrum does not resemble the Landau levels. In order to understand the origin of the oscillations, we also perform the Franz-Tesanovic transformation in the presence of the loop order and find that in addition to scalar and the Berry potentials [M. Franz and Z. Tešanović, Phys. Rev. Lett. 84, 554 (2000)], one component of the gauge invariant superfluid velocity couples to the low-lying Dirac particles as a component of a vector potential. The magnetic field associated with this vector potential vanishes on average but is highly nonuniform in the magnetic unit cell. We attribute the quantum oscillations to this field. We also compare the results with the model without the loop order but with the Zeeman-like coupling, which also induces the Fermi pockets in the superconducting state. [ABSTRACT FROM AUTHOR]

We study a model of a two-dimensional repulsive Fermi gas with Rashba spin-orbit coupling UR and investigate the superconducting instability using the renormalization-group approach. We find that, in general, superconductivity is enhanced as the dimensionless ratio Due to image rights restrictions, multiple line equation(s) cannot be graphically displayed. increases, resulting in unconventional superconducting states which break time-reversal symmetry. [ABSTRACT FROM AUTHOR]

The Imbert-Fedorov (IF) shift in optics describes the transverse shift of light beams at the reflection interface. Recently, the IF shift of Weyl fermions at the interface between Weyl semimetals (WSMs) with single monopole charge has been studied. Here, we study the IF shift at the interface between two WSMs, each of which is carrying an arbitrary integer monopole charge. We find a general relation between the monopole charges of the two WSMs and the IF shift. In particular, the IF shift is proportional to the monopole charge if both WSMs have the same one. Our results can be used to infer the topology of the materials by experimentally measuring their IF shift. Furthermore, we consider the possibility that the Weyl fermions are scattered to other Weyl cones during the reflection, which results in qualitatively different behavior of the IF shift. While we use a quantum mechanical approach to solve the problem, semiclassical equations of motion and the conservation of total angular momentum can help us intuitively interpret our results in special cases. [ABSTRACT FROM AUTHOR]

We report infrared studies of AFe2As2 (A=Ba, Sr), two representative parent compounds of iron-arsenide superconductors, at magnetic fields (B) up to 17.5 T. Optical transitions between Landau levels (LLs) were observed in the antiferromagnetic states of these two parent compounds. Our observation of a √B dependence of the LL transition energies, the zero-energy intercepts at B=0 T under the linear extrapolations of the transition energies and the energy ratio (~2.4) between the observed LL transitions, combined with the linear band dispersions in two-dimensional (2D) momentum space obtained by theoretical calculations, demonstrates the existence of massless Dirac fermions in the antiferromagnet BAFe2As2. More importantly, the observed dominance of the zeroth-LL-related absorption features and the calculated bands with extremely weak dispersions along the momentum direction kz indicate that massless Dirac fermions in BAFe2As2 are 2D. Furthermore, we find that the total substitution of the barium atoms in BAFe2As2 by strontium atoms not only maintains 2D massless Dirac fermions in this system, but also enhances their Fermi velocity, which supports that the Dirac points in iron-arsenide parent compounds are topologically protected. [ABSTRACT FROM AUTHOR]

It was recently shown that nonsymmorphic space-group symmetries can protect novel surface states with hourglasslike dispersions. In this paper, we show that such dispersions can also appear in the bulk of three-dimensional (3D) systems which respect nonsymmorphic symmetries. Specifically, we construct 3D lattice models featuring hourglasslike dispersions in the bulk, which are protected by nonsymmorphic and time-reversal symmetries. We call such systems hourglass semimetals, as they have point or line nodes associated with hourglasslike dispersions. Hourglass nodal lines appear in glide-invariant planes, while hourglass Weyl points can occur on screw-invariant axes. The Weyl points and surface Fermi arcs in hourglass Weyl semimetals are stable against weak perturbations breaking those nonsymmorphic symmetries. Our results may shed light on searching for exotic Weyl semimetals in nonsymmorphic materials. [ABSTRACT FROM AUTHOR]

• FC, D r , and CSR significantly affect the development characteristics of excess water pore pressure(EPWP) in saturated marine coral sand. • EPWP shows a "sharp–smooth" development mode with γ a , and there is an arctangent relationship between r u and γ a. • A prediction model for the development of EPWP based on shear strain characteristics was proposed. • A virtually unique form of the correlation between the density-corrected EPWP model parameter B /(D r)1.5 and e sk * exists. Using a hollow-cylinder torsional shear apparatus, we experimentally investigated the development characteristics of excess pore water pressure (EPWP) in saturated marine coral sand. These coral sand specimens were tested under various values of nonplastic fines content (FC), relative density (D r), and cyclic stress ratio (CSR). A laboratory cyclic torsional shear test under isotropic consolidation showed that the development rate of the EPWP ratio (R u) versus the number of cycles (N) increased with increasing FC and CSR but decreased with increasing D r. Additionally, the increase in FC significantly reduced the cyclic resistance ratio (CRR) of marine coral sand. For a given D r and FC, R u of the specimens under different CSR was uniquely related to the amplitude of the shear strain (γ a). Moreover, a pore pressure evaluation model based on shear strain characteristics was established. The measurements showed that the EPWP model parameter A is a soil-specific constant, and the density-corrected EPWP model parameter B /(D r)1.5 has a single negative-power relationship with the equivalent skeleton void ratio (e sk *. [ABSTRACT FROM AUTHOR]

Metabotropic glutamate receptor 5 (mGluR5) and transient receptor potential vanilloid subtype 1 (TRPV1) have been shown to play critical roles in the transduction and modulation of cutaneous nociception in the central nervous system. However, little is known regarding the possible involvement of mGluR5 and TRPV1 in regulating visceral nociception from the uterine cervix. In this study, we used a rat model of uterine cervical distension to examine the effects of noxious stimuli to the uterine cervix on expression of spinal mGluR5 and TRPV1. Our findings included the following: (1) uterine cervical distension resulted in a stimulus-dependent increase in electromyographic, spinal c-Fos signal, and expression of mGluR5 and TRPV1 in the spinal cord; (2) intrathecal administration of the mGluR5 antagonist 2-methyl-6-(phenylethynyl)-pyri-dine significantly reduced the increased TRPV1 and c-Fos expression induced by uterine cervical distension; (3) the TRPV1 inhibitor SB-366791 inhibited increased spinal c-Fos expression but had no effect on the expression of mGluR5 in response to uterine cervical distension. Our findings indicate that the spinal mGluR5-TRPV1 pathway modulates nociceptive transmission in uterine cervical distension-induced pathological visceral pain. [ABSTRACT FROM AUTHOR]