Terms Of Masses Research Articles

Surface‐enhanced Raman scattering studies of gold‐coated ripple‐like nanostructures on iron substrate achieved by femtosecond laser irradiation in water

AbstractDuring the past several years, numerous efforts have been accomplished on designing efficient surface‐enhanced Raman scattering (SERS) substrates with high sensitivity, good reproducibility, and recyclable nature. However, it still remains a significant challenge to realize all these qualities in a single substrate. We have fabricated ripple‐like nanostructures (NSs) on Iron (Fe) substrate using femtosecond (fs) laser irradiation of Fe target in distilled water. These ripple‐like structures had periodicities in the range of ~90–190 nm, which was confirmed from the analysis of field emission scanning electron microscope (FESEM) data. We subsequently deposited a thin layer of gold on these ripple‐like Fe NSs using thermal evaporation. Later, these coated NSs were effectively utilized as SERS substrates for methylene blue (MB) detection and were found to be sensitive evident from the data obtained at a very low concentration of 500pM. Furthermore, we observed that the SERS signal variations on the substrate were <11.2% indicating the reproducible nature of these substrates. Additionally, we demonstrate that these substrates can be reused (we establish this for three times consecutively) by detecting malachite green (MG) and an explosive molecule (picric acid, PA) followed by the mixture compound (Rhodamine 6G+MB) through employment of simple cleaning procedures. The detected molecular concentrations in terms of masses were found to be 3.2 pg, 36.5 pg, and 23 ng for MB (for a concentration of 500pM), MG (for a concentration of 5nM), and PA (for a concentration of 5μM), respectively. Furthermore, these Fe NSs exhibited superior batch‐to‐batch reproducibility with a relative standard deviation (RSD) value of ~l4%. The proposed method of fabricating ripple structures as SERS platforms are highly feasible, reliable, and have great potential for on‐site detection of several analyte molecules with an easily transportable Raman spectrometer.

Neutrino mass matrix in a gauge group SU(2)L × U(1)e × U(1)μ × U(1)τ

The electroweak unification group [Formula: see text] in which each fermion multiplet has its own [Formula: see text] factor was proposed in 1986 to get the neutrino mass matrix. In this paper, the gauge group [Formula: see text] is restricted to lepton section only, leaving quark multiplets as in the Standard Model. In addition to lepton multiplets [Formula: see text], [Formula: see text] and [Formula: see text], there are three [Formula: see text] singlet right-handed neutrinos [Formula: see text]’s. With the breaking of [Formula: see text] to [Formula: see text], the right-handed neutrinos acquire heavy Majorana masses. Three heavy right-handed neutrinos [Formula: see text]’s are available to generate a [Formula: see text] nondiagonal neutrino mass matrix in terms of three Yukawa couplings [Formula: see text], [Formula: see text], [Formula: see text] of the Higgs scalar doublet to [Formula: see text], [Formula: see text], [Formula: see text] with [Formula: see text], [Formula: see text] and [Formula: see text], respectively. Three Yukawa couplings can be arranged and expressed in terms of masses [Formula: see text], [Formula: see text], [Formula: see text] in three different ways to obtain the results of interest for Case 1: [Formula: see text]; Case 2: [Formula: see text]; Case 3: [Formula: see text]. The results obtained for the three cases are compared with the experimental data from neutrino oscillations. Cases 1 and 2 are relevant for solar neutrino oscillations whereas Case 3 is relevant for atmospheric neutrino oscillations.

Pathogenicity of Meloidogyne incognita and M. javanica on recombinant inbred lines from a crossing of Cucurbita pepo subsp. pepo × C. pepo subsp. ovifera

The response of recombinant inbred lines (RILs) from a cross of zucchini × scallop (Cucurbita pepo subsp. pepo ‘Murcia MU‐CU‐16’ × C. pepo subsp. ovifera ‘Scallop UPV‐196’) to Meloidogyne incognita and M. javanica was determined after completion of a nematode reproduction cycle in experiments carried out in a growth chamber. The nematode differentiated the C. pepo genotypes at the subspecies level due to lower egg mass production on subspecies pepo than ovifera, and thus subspecies pepo was a poorer host than ovifera. In addition, Murcia MU‐CU‐16 discriminated M. incognita from M. javanica in terms of egg masses (EM), eggs per gram of root and reproduction factor (Rf), whereas Scallop UPV‐196 did so in eggs per gram of root and Rf. The RILs differed in gall formation and EM production depending on the nematode × line combination. Comparisons between nematode isolates resulted in four significant combinations for pathogenic potential (galls/initial population (Pi) × 100), seven for parasitic success (egg masses/Pi × 100), and nine for host efficiency (egg masses/galls per root system × 100) which included all the lines tested against both isolates. Lines that restricted nematode development by at least 90% were considered as having intermediate resistance to M. incognita based on the definition of the International Seed Federation. They included lines 28‐1, 35A, 107A, 110‐3 and 153‐2. All the RILs were susceptible hosts for M. javanica. The information presented here will be helpful for nematode management and also for plant breeders working on pathogen resistance on C. pepo.

A thorough study of Si nanowire FETs with 3D Multi-Subband Ensemble Monte Carlo simulations

We thoroughly compare the DC electrical behavior of n-MOS transistors based on Si nanowires with 〈100〉 and 〈110〉 channel orientations by means of Multi-Subband Ensemble Monte Carlo simulations. We find that the drain current depends on the nanowire diameter and it is slightly, but consistently, larger for 〈100〉 than for 〈110〉 nanowires. The observed differences in mobility, velocity and spatial charge distribution are interpreted in terms of the effective masses and populations of the different Si conduction band valleys, whose sixfold degeneracy is lifted by quantum confinement in narrow nanowires. Finally, we study the scaling behavior for channel lengths down to 8 nm, concluding that the differences observed between orientations are minimal.

In vitro and in vivo pharmacokinetics and metabolism of MK-8353 by liquid chromatography combined with diode array detector and Q-Exactive-Orbitrap tandem mass spectrometry

In this study, a simple and sensitive quantitation method based on liquid chromatography combined with diode array detector and Q-Exactive-Orbitrap tandem mass spectrometry was developed for the determination of MK-8353 in rat plasma. The chromatographic separation was carried out on a Waters ACQUITY BEH C18 column by using water containing 1 mM ammonium acetate and acetonitrile containing 0.1% formic acid as mobile phase. The developed assay was linear (r > 0.999) over the concentration range of 1–1000 ng/mL. The selectivity, precision, accuracy, recovery, matrix effects and stability were all within the required limits. The validated assay has been further applied to the pharmacokinetic study of MK-8353 in rat after intravenous and oral administration, which revealed that MK-8353 showed low clearance and satisfactory bioavailability. More importantly, the metabolites of MK-8353 present in rat plasma, RLM, DLM and HLM were identified and profiled. Under the current conditions, a total of 10 metabolites were detected and their chemical structures were proposed in terms of the accurate masses and their fragment ions. Our results revealed that MK-8353 was metabolized mainly through dealkylation, demethylation, depropylation, oxygenation, sulfur oxidation and formation of lactam. Compared with animal species, no human-specific metabolite was found in HLM. This study provides overall in vitro and in vivo profiles of MK-8353, which is of great help in understanding its PK/PD profiles and in predicting human pharmacokinetic profiles.

A mean field equation involving positively supported probability measures: blow-up phenomena and variational aspects

AbstractWe are concerned with an elliptic problem which describes a mean field equation of the equilibrium turbulence of vortices with variable intensities. In the first part of the paper, we describe the blow-up picture and highlight the differences from the standard mean field equation as we observe non-quantization phenomenon. In the second part, we discuss the Moser–Trudinger inequality in terms of the blow-up masses and get the existence of solutions in a non-coercive regime by means of a variational argument, which is based on some improved Moser–Trudinger inequalities.

Robotic Gripper for Payload Capture in Low Earth Orbit

The consensus to a study phase for an Intermediate eXperimental Vehicle (IXV) successor, a preoperational vehicle called Space Reusable Integrated Demonstrator for European Return (SPACE RIDER), has been recently enlarged, as approved during last EU Ministerial Council. One of the main project tasks consists in developing SPACE RIDER to conduct on orbit servicing activity with no docking. SPACE RIDER would be provided with a robotic manipulator system (arm and gripper) able to transfer cargos, such as scientific payloads, from low Earth orbiting platforms to the SPACE RIDER cargo bay. The platform is a part of a space tug designed to move small satellites and other payloads from Low Earth Orbit to Geosynchronous Equatorial Orbit and vice versa. A study on this robotic technology is here presented. This research is carried out by Politecnico di Torino and Thales Alenia Space Italy. The system configuration of the robotic manipulator is first described in terms of volumes and masses. The considered housing cargo bay requirements in terms of volume (< 100 l) and mass (< 50 kg) combined with the required overall arm dimensions (4 m length), and mass of the cargo (5–30 kg) force to developing an innovative robotic manipulator with the task-oriented end-effector. It results in a 7df arm to ensure a high degree of dexterity and a dedicated end-effector designed to grasp the cargo interface. The gripper concept here developed consists in a multi-finger hand able to lock both translational and rotational cargo degrees of freedom through an innovative under-actuation strategy to limit its mass and volume. A configuration study on the cargo handle interface has also been performed together with some computer-aided design models and multibody analysis of the whole system to prove its feasibility. Finally, the concept of system control architecture is defined.

Framework for the chiral extrapolation of the charmed baryon ground-state masses

We consider the chiral Lagrangian for charmed baryon fields with $J^P =\frac{1}{2}^+$ or $J^P =\frac{3}{2}^+$ quantum numbers. A chiral expansion framework for the baryon ground state masses is worked out to N$^3$LO as to compute their dependence on the up, down and strange quark masses for finite box QCD lattice simulations. It is formulated in terms of on-shell meson and baryon masses. The convergence of such a scheme is illustrated with physical masses as taken from the PDG. The counter terms relevant at N$^3$LO are correlated systematically by large-$N_c$ sum rules to leading and subleading order in a manner that keeps the renormalization scale invariance of the approach.

On the convergence of the chiral expansion for the baryon ground-state masses

We study the chiral expansion of the baryon octet and decuplet masses in the isospin limit. It is illustrated that a chiral expansion of the one-loop contributions is rapidly converging up to quark masses that generously encompasses the mass of the physical strange quark. We express the successive orders in terms of physical meson and baryon masses. In addition, owing to specific correlations amongst the chiral moments, we suggest a reordering of terms that make the convergence properties more manifest. Explicit expressions up to chiral order five are derived for all baryon masses at the one-loop level. The baryon masses obtained do not depend on the renormalization scale. Our scheme is tested against QCD lattice data, where the low-energy parameters are systematically correlated by large-Nc sum rules. A reproduction of the baryon masses from PACS-CS, LHPC, HSC, NPLQCD, QCDSF-UKQCD and ETMC is achieved for ensembles with pion and kaon masses smaller than 600 MeV. Predictions for baryon masses on ensembles from CLS as well as all low-energy constants that enter the baryon masses at N3LO are made.

Tidal disruption of inclined or eccentric binaries by massive black holes

Binary stars that are on close orbits around massive black holes (MBH) such as Sgr A* in the center of the Milky Way are liable to undergo tidal disruption and eject a hypervelocity star. We study the interaction between such a MBH and circular binaries for general binary orientations and penetration depths (i.e. binaries penetrate into the tidal radius around the BH). We show that for very deep penetrators, all binaries are disrupted when the binary rotation axis is roughly oriented toward the BH or it is in the opposite direction. The surviving chance becomes significant when the angle between the binary rotation axis and the BH direction is between \pi /4 and 3 \pi /4. The surviving chance is as high as $\sim$ 20$\%$ when the binary rotation axis is perpendicular to the BH direction. The angular dependence is opposite for very shallow penetrators where coplanar prograde orbits have the lowest surviving chance (or equivalently most vulnerable). We provide numerical fits to the disruption probability and energy gain at the the BH encounter as a function of the penetration depth. The latter can be simply rescaled in terms of binary masses, their initial separation and the binary-to-BH mass ratio to evaluate the ejection velocity of a binary members in various systems. We also investigate the disruption of coplanar, eccentric binaries by a MBH. It is shown that for highly eccentric binaries retrograde orbits have a significantly increased disruption probability and ejection velocities compared to the circular binaries.

Realistic simplified gaugino-higgsino models in the MSSM

We present simplified MSSM models for light neutralinos and charginos with realistic mass spectra and realistic gaugino-higgsino mixing, that can be used in experimental searches at the LHC. The formerly used naive approach of defining mass spectra and mixing matrix elements manually and independently of each other does not yield genuine MSSM benchmarks. We suggest the use of less simplified, but realistic MSSM models, whose mass spectra and mixing matrix elements are the result of a proper matrix diagonalisation. We propose a novel strategy targeting the design of such benchmark scenarios, accounting for user-defined constraints in terms of masses and particle mixing. We apply it to the higgsino case and implement a scan in the four relevant underlying parameters {mu , tan beta , M_{1}, M_{2}} for a given set of light neutralino and chargino masses. We define a measure for the quality of the obtained benchmarks, that also includes criteria to assess the higgsino content of the resulting charginos and neutralinos. We finally discuss the distribution of the resulting models in the MSSM parameter space as well as their implications for supersymmetric dark matter phenomenology.

Relations between heavy-light meson and quark masses

The study of heavy-light meson masses should provide a way to determine renormalized quark masses and other properties of heavy-light mesons. In the context of lattice QCD, for example, it is possible to calculate hadronic quantities for arbitrary values of the quark masses. In this paper, we address two aspects relating heavy-light meson masses to the quark masses. First, we introduce a definition of the renormalized quark mass that is free of both scale dependence and renormalon ambiguities, and discuss its relation to more familiar definitions of the quark mass. We then show how this definition enters a merger of the descriptions of heavy-light masses in heavy-quark effective theory and in chiral perturbation theory ($\chi$PT). For practical implementations of this merger, we extend the one-loop $\chi$PT corrections to lattice gauge theory with heavy-light mesons composed of staggered fermions for both quarks. Putting everything together, we obtain a practical formula to describe all-staggered heavy-light meson masses in terms of quark masses as well as some lattice artifacts related to staggered fermions. In a companion paper, we use this function to analyze lattice-QCD data and extract quark masses and some matrix elements defined in heavy-quark effective theory.

Stochastic approach for radionuclides quantification

Gamma spectrometry is a passive non-destructive assay used to quantify radionuclides present in more or less complex objects. Basic methods using empirical calibration with a standard in order to quantify the activity of nuclear materials by determining the calibration coefficient are useless on non-reproducible, complex and single nuclear objects such as waste packages. Package specifications as composition or geometry change from one package to another and involve a high variability of objects. Current quantification process uses numerical modelling of the measured scene with few available data such as geometry or composition. These data are density, material, screen, geometric shape, matrix composition, matrix and source distribution. Some of them are strongly dependent on package data knowledge and operator backgrounds. The French Commissariat à l’Energie Atomique (CEA) is developing a new methodology to quantify nuclear materials in waste packages and waste drums without operator adjustment and internal package configuration knowledge. This method suggests combining a global stochastic approach which uses, among others, surrogate models available to simulate the gamma attenuation behaviour, a Bayesian approach which considers conditional probability densities of problem inputs, and Markov Chains Monte Carlo algorithms (MCMC) which solve inverse problems, with gamma ray emission radionuclide spectrum, and outside dimensions of interest objects. The methodology is testing to quantify actinide activity in different kind of matrix, composition, and configuration of sources standard in terms of actinide masses, locations and distributions. Activity uncertainties are taken into account by this adjustment methodology.

Analysis of high reverse currents of 4H-SiC Schottky-barrier diodes

Nickel (Ni), titanium (Ti), and molybdenum (Mo) 4H-silicon carbide Schottky-barrier diodes (SiC SBDs) were fabricated and used to investigate the relation between forward and reverse currents. Temperature dependence of reverse current follows a theory that includes tunneling in regard to thermionic emission, namely, temperature dependence is weak at low temperature but strong at high temperatures. On the other hand, the reverse currents of the Ni and Mo SBDs are higher than their respective currents calculated from their Schottky barrier heights (SBHs), whereas the reverse current of the Ti SBD agrees well with that calculated from its SBH. The cause of the high reverse currents was investigated from the viewpoints of low barrier patch, Gaussian distribution of barrier height (GD), thin surface barrier, and electron effective mass. The high reverse current of the Ni and Mo SBDs can be explained not in terms of a low-barrier patch, GD, or thin surface barrier but in terms of small effective masses. Investigation of crystal structures at the Schottky interface revealed a large lattice mismatch between the metals (Ni, Ti, or Mo) and SiC for the Ni and Mo SBDs. The small effective mass is possibly attributed to the large lattice mismatch, which might generate transition layers at the Schottky interface. It is concluded from these results that the lattice constant as well as the work function is an important factor in selecting the metal species as the Schottky metal for wide band-gap SBDs, for which tunneling current dominates reverse current.

Leptonic invariants, neutrino mass-ordering and the octant of \u03b823

We point out that leptonic weak-basis invariants are an important tool for the study of the properties of lepton flavour models. In particular, we show that appropriately chosen invariants can give a clear indication of whether a particular lepton flavour model favours normal or inverted hierarchy for neutrino masses and what is the octant of θ23. These invariants can be evaluated in any conveniently chosen weak-basis and can also be expressed in terms of neutrino masses, charged lepton masses, mixing angles and CP violation phases.

Entrainment in Superfluid Neutron-Star Crusts: Hydrodynamic Description and Microscopic Origin

In spite of the absence of viscous drag, the neutron superfluid permeating the inner crust of a neutron star cannot flow freely, and is entrained by the nuclear lattice similarly to laboratory superfluid atomic gases in optical lattices. The role of entrainment on the neutron superfluid dynamics is reviewed. For this purpose, a minimal hydrodynamical model of superfluidity in neutron-star crusts is presented. This model relies on a fully four-dimensionally covariant action principle. The equivalence of this formulation with the more traditional approach is demonstrated. In addition, the different treatments of entrainment in terms of dynamical effective masses or superfluid density are clarified. The nuclear energy density functional theory employed for the calculations of all the necessary microscopic inputs is also reviewed, focusing on superfluid properties. In particular, the microscopic origin of entrainment and the different methods to estimate its importance are discussed.

Neutrinoless double-beta decays: New insights

We give some new insights into the effective Majorana neutrino mass [Formula: see text] responsible for the neutrinoless double-beta [Formula: see text] decays. We put forward a three-dimensional way of plotting [Formula: see text] against the lightest neutrino mass and the Majorana phases, which can provide more information as compared with the two-dimensional one. With the help of such graphs we discover a novel threshold of [Formula: see text] in terms of the neutrino masses and flavor mixing angles: [Formula: see text] in connection with [Formula: see text] and [Formula: see text], which can be used to signify observability of the future [Formula: see text]-decay experiments. Fortunately, the possibility of [Formula: see text] turns out to be very small, promising a hopeful prospect for the [Formula: see text]-decay searches.

Transcription factor NnDREB1 from lotus improved drought tolerance in transgenic Arabidopsis thaliana

Dehydration responsive element binding factor (DREB) is believed to be a stress-tolerance enhancer in plants. In the present study, a cold-binding factor (CBF)/DREB homologous gene NnDREB1 (XP_010242642.1) was isolated from lotus roots using rapid amplification of cDNA ends (RACE) and reverse transcription (RT)-PCR methods. Analysis of the deduced amino acid sequence and phylogeny classified NnDREB1 into the A-1 group of the DREB1 subfamily. Expression profiling using a quantitative PCR method revealed that NnRDEB1 was significantly induced by NaCl, mannitol, and polyethylene glycol, but not by low temperature and abscisic acid. To evaluate function of NnRDEB1, Arabidopsis thaliana was transformed with the NnDREB1 gene in a binary vector construct. The transgenic plants exhibited higher resistance to drought compared with the wild-type plants in terms of survival rates, dry and fresh masses, and chlorophyll content. In addition, overexpression of NnDREB1 resulted in higher germination rates compared with the wild type plants on MS medium containing mannitol. The expressions of downstream target stressrelated genes, including cold-regulated15B (COR15B), rare cold inducible 2B (RCI2B) and repeat domain 26 (RD26), were activated in the transgenic plants. Taken together, the results suggest that NnDREB1 might be an important protein in lotus root drought tolerance.

High-Throughput Design of Non-oxide p-Type Transparent Conducting Materials: Data Mining, Search Strategy, and Identification of Boron Phosphide

High-performance p-type transparent conducting materials (TCMs) are needed in a wide range of applications ranging from solar cells to transparent electronics. p-type TCMs require a large band gap (for transparency), low hole effective mass (for high mobility), and hole dopability. It has been demonstrated that oxides have inherent limitations in terms of hole effective masses making them difficult to use as a high-performance p-type TCM. In this work, we use a high-throughput computational approach to identify novel, non-oxide, p-type TCMs. By data mining a large computational data set (more than 30,000 compounds), we demonstrate that non-oxide materials can lead to much lower hole effective masses but to the detriment of smaller gaps and lower transparencies. We propose a strategy to overcome this fundamental correlation between low effective mass and small band gap by exploiting the weak absorption for indirect optical transitions. We apply this strategy to phosphides and identify zinc blende boron pho...

Weak lensing calibration of mass bias in the REFLEX+BCS X-ray galaxy cluster catalogue

The use of large, X-ray selected galaxy cluster catalogues for cosmological analyses requires a thorough understanding of the X-ray mass estimates. Weak gravitational lensing is an ideal method to shed light on such issues, due to its insensitivity to the cluster dynamical state. We perform a weak lensing calibration of 166 galaxy clusters from the REFLEX and BCS cluster catalogue and compare our results to the X-ray masses based on scaled luminosities from that catalogue. To interpret the weak lensing signal in terms of cluster masses, we compare the lensing signal to simple theoretical Navarro-Frenk-White models and to simulated cluster lensing profiles, including complications such as cluster substructure, projected large-scale structure, and Eddington bias. We find evidence of underestimation in the X-ray masses, as expected, with $\langle M_{\mathrm{X}}/M_{\mathrm{WL}}\rangle = 0.75 \pm 0.07$ stat. $\pm 0.05$ sys. for our best-fit model. The biases in cosmological parameters in a typical cluster abundance measurement that ignores this mass bias will typically exceed the statistical errors.