Robustness of the intrinsic anomalous Hall effect in Fe3GeTe2 to a uniaxial strain

Fe3GeTe2 (FGT), a ferromagnetic van der Waals topological nodal line semimetal, has recently been studied. Using first-principles calculations and symmetry analysis, we investigate the effect of a uniaxial tensile strain on the nodal line and the resultant intrinsic anomalous Hall effect (AHE). Our results reveal their robustness to the in-plane strain. Moreover, the intrinsic AHE remains robust even for artificial adjustment of the atomic positions introduced to break the crystalline symmetries of FGT. When the spin-orbit coupling is absent, the nodal line degeneracy remains intact as long as the inversion symmetry or the two-fold screw symmetry is maintained, which reveal that the nodal line may emerge much more easily than previously predicted. This strong robustness is surprising and disagrees with the previous experimental report [Y. Wang et al., Adv. Mater. 32, 2004533 (2020)], which reports that a uniaxial strain of less than 1 % of the in-plane lattice constant can double the anomalous Hall resistance. This discrepancy implies that the present understanding of the AHE in FGT is incomplete. The possible origins of this discrepancy are discussed.Comment: 7 pages, 3 figure

Orientational dependence of intrinsic orbital and spin Hall effects in hcp structure materials

We investigate the orientation dependence of the intrinsic orbital Hall effect (OHE) and spin Hall effect (SHE) in hexagonal close-packed (hcp) structure materials. The symmetry constraints of the hcp structure restrict the orbital (spin) current to the orbital (spin) Hall current. It also shows that there exist three symmetry-wise independent orientations in the hcp structure. We calculate the orbital Hall conductivity (OHC) and the spin Hall conductivity (SHC) of three hcp materials (Sc, Y, and Zr). We find that all these materials have sizable OHC, while the SHC is orders of magnitude smaller. Especially, the OHCs of Sc and Zr have significant orientation dependence, which may be employed to experimentally probe the OHE.11Nsciescopu

28-GHz CMOS Direct-Conversion RF Transmitter with Precise and Wide-Range Mismatch Calibration Techniques

A millimeter-wave direct-conversion radio-frequency (RF) transmitter requires precise in-/quadrature-phase (I/Q) mismatch calibration and dc offset cancellation to minimize image rejection ratio (IRR) and LO feedthrough (LOFT) for ensuring satisfactory output spectral purity. We present a 28-GHz CMOS RF transmitter with an improved calibration technique for fifth generation (5G) wireless communication applications. The RF transmitter comprises a baseband amplifier, quadrature up-conversion mixer, power amplifier driver, and quadrature LO generator. The I/Q amplitude mismatch is calibrated by tuning the gate biases of the switching stage FETs of the mixer, the I/Q phase mismatch is calibrated by tuning the varactor capacitances at the LC load of LO buffer, and the dc offset is cancelled by tuning the body voltages of the differential-pair FETs at the baseband amplifier. The proposed technique provides precise calibration accuracy by employing mV-resolution tuning voltage generation via 6-bit voltage digital-to-analog converters. It also covers wide calibration range while minimizing the impact on the circuit’s bias point and dissipated current during calibration. Implemented in a 65 nm CMOS process, the RF transmitter integrated circuit shows output-referred 1 dB compression power of +6.5 dBm, saturated output power of +12.6 dBm, and an operating band of 27.5–29.3 GHz while demonstrating satisfactory performances of −55.9 dBc of IRR and −36.8 dBc of LOFT

PIXEL: Physics-Informed Cell Representations for Fast and Accurate PDE Solvers

With the increases in computational power and advances in machine learning, data-driven learning-based methods have gained significant attention in solving PDEs. Physics-informed neural networks (PINNs) have recently emerged and succeeded in various forward and inverse PDE problems thanks to their excellent properties, such as flexibility, mesh-free solutions, and unsupervised training. However, their slower convergence speed and relatively inaccurate solutions often limit their broader applicability in many science and engineering domains. This paper proposes a new kind of data-driven PDEs solver, physics-informed cell representations (PIXEL), elegantly combining classical numerical methods and learning-based approaches. We adopt a grid structure from the numerical methods to improve accuracy and convergence speed and overcome the spectral bias presented in PINNs. Moreover, the proposed method enjoys the same benefits in PINNs, e.g., using the same optimization frameworks to solve both forward and inverse PDE problems and readily enforcing PDE constraints with modern automatic differentiation techniques. We provide experimental results on various challenging PDEs that the original PINNs have struggled with and show that PIXEL achieves fast convergence speed and high accuracy. Project page: https://namgyukang.github.io/PIXEL

Multiscale Phase Behaviors of Nematic Solids: A Short Review

Nematic liquid crystalline solids are novel smart materials of which mesogenic molecules are incorporated within their polymeric chains via crosslinking. The material exhibits many interesting phase behaviors and is envisaged to be harnessed as a key material of soft responsive structures that are adaptive to their surroundings. These behaviors are originated by intricate interactions between diverse phenomena ranging from molecular interactions, mesoscopic phase transition, and elasticity of macroscale. The modeling and analysis of the behavior, therefore, requires the multiscale point of view in that the vast design space of such material cannot be fully exploited otherwise. In this regard, the multiscale behaviors of the nematic solids are first visited, elucidating qualitative behaviors and research of individual physics. Further, the multiscale analysis approach applied to understand and harness the behaviors of the nematic liquid crystalline solids is then reviewed

Effects of Feed Composition in Different Growth Stages on Rumen Fermentation and Microbial Diversity of Hanwoo Steers

Ruminants are a major source of greenhouse gas emissions, and information on ruminant fermentation and microorganisms is essential to understand ruminant digestion, which is associated with environmental pollution. The present study investigated rumen fermentation and microbial diversity according to the three different growth stages of four Hanwoo steers: growing (12 months, G), early fattening (18 months, EF), and late fattening (25 months, LF). No significant differences were observed in rumen pH and ammonia nitrogen among growth stages. Total volatile fatty acids were significantly higher and propionate and valerate significantly lower in G than in EF and LF (p p p = 0.056). Given the differences in the genera of microorganisms with relatively low abundance, additional experiments are needed to determine the effect on fermentation

A controlled growth of WNx, and WCx thin films prepared by atomic layer deposition

This work reports a capability for a controlled preparation of tungsten nitride and carbide thin films via an atomic layer deposition (ALD) approach. Those films were deposited by ALD using a fluorine- and nitrogen -free W metallorganic precursor of tungsten tris(3-hexyne) carbonyl [W(CO)(CH3CH2C CH2CH3)] and a N-2 + H-2 mixture plasma as a reactant at a deposition temperature of 250 degrees C. It was found that a phase, microstructure and composition of the films could be controlled in precision by varying a gas flow rate ratio of N-2/H-2 in the plasma reactant. With the N-2/H-2 gas ratio of 1:3 and 1:5, W -rich polycrystalline WNx thin films (W/N ratio: similar to 1.39) were deposited with a resistivity of 700-900 mu Omega cm, while nano -crystalline (close to an amorphous) W -rich WCx films (W/C ratio: similar to 1.26) with a much lower resistivity of similar to 510 mu Omega cm, without any nitrogen incorporation, were formed when H-2 gas became extremely rich (N-2/H-2 gas ratio of 1:10). Both X-ray diffraction and electron diffraction analyses revealed that the ALD-WCx films were composed of hexagonal W2C, WC, and non-stoichiometric cubic beta-WCx. while the ALD-WNx films of cubic W2N. (C) 2016 Elsevier B.V. All rights reserved

Revealing the function of a novel splice-site mutation of CHD7 in CHARGE syndrome

Most cases of CHARGE syndrome are sporadic and autosomal dominant. CHD7 is a major causative gene of CHARGE syndrome. In this study, we screened CHD7 in two Turkish patients demonstrating symptoms of CHARGE syndrome such as coloboma, heart defect, choanal atresia, retarded growth, genital abnomalities and ear anomalies. Two mutations of CHD7 were identified including a novel splice-site mutation (c.2443-2A>G) and a previously known frameshift mutation (c.2504_2508delATCTT). We performed exon trapping analysis to determine the effect of the c.2443-2A>G mutation at the transcriptional level, and found that it caused a complete skip of exon 7 and splicing at a cryptic splice acceptor site. Our current study is the second study demonstrating an exon 7 deficit in CHD7. Results of previous studies suggest that the c.2443-2A>G mutation affects the formation of nasal tissues and the neural retina during early development, resulting in choanal atresia and coloboma, respectively. The findings of the present study will improve our understanding of the genetic causes of CHARGE syndrome. (C) 2015 Elsevier B.V. All rights reserved

Effective PEI-mediated delivery of CRISPR-Cas9 complex for targeted gene therapy

The-state-of-art CRISPR/Cas9 is one of the most powerful among the approaches being developed to rescue fundamental causes of gene-based inheritable diseases. Several strategies for delivering such genome editing materials have been developed, but the safety, efficacy over time, cost of production, and gene size limitations are still under debate and must be addressed to further improve applications. In this study, we evaluated branched forms of the polyethylenimine (PEI) - branched PEI 25 kDa (BPEI-25K) - and found that it could efficiently deliver CRISPR/Cas9 plasmids. Plasmid DNA expressing both guide RNA and Cas9 to target the Slc26a4 locus was successfully delivered into Neuro2a cells and meditated genome editing within the targeted locus. Our results demonstrated that BPEI-25K is a promising non-viral vector to deliver the CRISPR/Cas9 system in vitro to mediate targeted gene therapy, and these findings contribute to an understanding of CRISPR/Cas9 delivery that may enable development of successful in vivo techniques. (c) 2018 Elsevier Inc. All rights reserved.11Nsciescopu

Effects of Dietary Inclusion Level of Microwave-Dried and Press-Defatted Black Soldier Fly (<i>Hermetia illucens</i>) Larvae Meal on Carcass Traits and Meat Quality in Broilers

Limited information is available regarding the use of microwave-dried Hermetia illucens larvae meal (HILM) as a dietary protein source for broiler diets. Therefore, we investigated the effects of microwave-dried HILM on carcass traits, meat quality, fatty acid (FA) profiles of abdominal fat and meat, and heavy metal residues of the meat in broilers. A total of 126 male broilers were randomly assigned to three dietary treatment groups (6 replicates and 7 birds/pen): a control diet and two experimental diets in which soybean meal was replaced with 25 or 50% HILM. The broilers were slaughtered at 35 days; the carcasses were weighed, and breast and leg meats were excised from 12 birds per treatment (2 birds/pen) for meat analysis. The breast meat quality and proximate composition showed satisfactory results. For the higher HILM diet, the content of saturated FA in the abdominal fat was increased and that of polyunsaturated FA was decreased (p p < 0.001) in the 50% HILM group. Microwave-dried HILM is a potential ingredient for broiler diets, with up to 25% substitution showing no detrimental effects on carcass traits, meat quality, FA profiles, and heavy metal residues in the meat