Miracle-dz/UniFAR-FTUs huggingface dataset:
Proxy‐Based Preformed Phosphate Estimates Point to Increased Biological Pump Efficiency as Primary Cause of Last Glacial Maximum CO2 Drawdown

Upwelling deep waters in the Southern Ocean release biologically sequestered carbon into the atmosphere, contributing to the relatively high atmospheric CO2 levels during interglacial climate periods. Paleoceanographic evidence suggests this “CO2 leak” was lessened during the last glacial maximum (LGM), potentially due to increased stratification, weaker and equatorward‐shifted winds, and/or enhanced biological carbon export. The collective influences of these mechanisms on the ocean's biological pump efficiency and amount of atmospheric CO2 can be quantified by determining preformed phosphate of deep waters. We quantify preformed PO4 (Ppre,AOU) and preformed δ13C ${\delta }^{13}\mathrm{C}$ ( δ13Cpre,AOU ${\delta }^{13}{\mathrm{C}}_{\mathrm{p}\mathrm{r}\mathrm{e},\mathrm{A}\mathrm{O}\mathrm{U}}$ ) of LGM bottom waters using a compilation of published paleo‐temperature, nutrient and oxygen estimates from benthic foraminifera. Our results show that preformed phosphate of the Pacific and Indian deep oceans was reduced by about −0.53 ± 0.13 μM and suggest that much (64 ± 28 ppmv) of the Glacial‐Interglacial CO2 drawdown resulted from changes in the ocean's biological pump efficiency. Once carbonate compensation is accounted for, this can explain the entire CO2 drawdown (87 ± 40 ppmv). Preformed δ13C ${\delta }^{13}\mathrm{C}$ shows similar results. The reconstructed LGM Ppre,AOU and oxygen are qualitatively consistent with the changes produced by a suite of numerical sensitivity experiments that roughly simulate three proposed mechanisms for an increase in LGM biological pump efficiency: an increase in biological activity, a decrease in wind‐driven upwelling, and an increase in stratification in the Southern Ocean.
A parametric description of the 3D structure of the Galactic bar/bulge using the VVV survey

We study the structure of the inner Milky Way using the latest data release of the Vista Variables in Via Lactea (VVV) survey. The VVV is a deep near-infrared, multi-colour photometric survey with a coverage of 300 square degrees towards the Bulge/Bar. We use Red Clump (RC) stars to produce a high-resolution dust map of the VVV's field of view. From de-reddened colour-magnitude diagrams we select Red Giant Branch stars to investigate their 3D density distribution within the central 4 kpc. We demonstrate that our best-fit parametric model of the Bulge density provides a good description of the VVV data, with a median percentage residual of 5$\%$ over the fitted region. The strongest of the otherwise low-level residuals are overdensities associated with a low-latitude structure as well as the so-called X-shape previously identified using the split RC. These additional components contribute only $\sim5\%$ and $\sim7\%$ respectively to the Bulge mass budget. The best-fit Bulge is `boxy' with an axis ratio of [1:0.44:0.31] and is rotated with respect to the Sun-Galactic Centre line by at least $20^{\circ}$. We provide an estimate of the total, full sky, mass of the Bulge of $M_\mathrm{Bulge}^{\mathrm{Chabrier}} = 2.36 \times 10^{10} M_{\odot}$ for a Chabrier initial mass function. We show there exists a strong degeneracy between the viewing angle and the dispersion of the Red Clump absolute magnitude distribution. The value of the latter is strongly dependent on the assumptions made about the intrinsic luminosity function of the Bulge.
Photosynthetic Traits of Páramo Plants Subjected to Short-Term Warming in OTC Chambers

Global warming and changes in land use are some of the main threats to high mountain species. Both can interact in ways not yet assessed. In this study, we evaluated the photosynthetic responses of six common páramo species within a warming experiment using open-top chambers (OTC) in conserved páramo areas with different land use histories. We did not find significant differences in the photochemical performance of the species as measured through Fv/Fm, ETR, and NPQ in response to passive warming, indicating that warmed plants are not stressed. However, NPQ values were higher in recovering areas, especially in the driest and warmest months. Leaf transpiration, stomatal conductance, and Ci were not affected by the OTC or the land use history. The photosynthetic capacity, maximum photosynthetic capacity, and carboxylation rate of RuBisCO increased in response to warming but only in the area with no anthropogenic intervention. These results suggest that species will respond differently to warming depending on the history of páramo use, and therefore not all páramo communities will respond equally to climate change. In disturbed sites with altered soil conditions, plants could have a lower breadth of physiological response to warming.
Quasigeostrophic Transient Wave Activity Flux: Updated Climatology and Its Role in Polar Vortex Anomalies

Abstract The climatology of transient wave activity flux defined by Plumb has been calculated for each calendar month, for high-frequency (HF) and low-frequency (LF) waves, using the NCAR–NCEP reanalyses for both hemispheres. Wave activity flux of both HF and LF waves shows upward propagation of waves from the lower troposphere into the upper troposphere, then into the lower stratosphere during the summer and at least up to the midstratosphere during other seasons. While the upward flux emanating from the lower troposphere is particularly large in the two storm tracks in the Northern Hemisphere (NH), it is large in most of the extratropics in the Southern Hemisphere (SH). The HF waves radiate equatorward most noticeably in the upper troposphere, whereas the LF waves do not show visible signs of equatorward radiation. The total horizontal flux is generally dominated by the advective flux that represents the eddy enstrophy advection by the mean flow and appears predominantly pseudoeastward. Divergence of th.
Submillimeter Imaging of RCS J022434–0002.5: Intense Activity in a High-Redshift Cluster?

We present deep 850 μm imaging of the z = 0.773 strong lensing galaxy cluster RCS J022434-0002.5 from the Red-Sequence Cluster Survey (RCS). These data are part of a larger submillimeter survey of RCS clusters with SCUBA on the JCMT. We find five objects at 850 μm, all of which are also detected at either 1.4 GHz or 450 μm, or both. The number density of objects in this field is in general agreement with the blank-field source counts; however, when combined with other cluster surveys a general tendency of cluster fields toward higher submillimeter number densities is seen, which may be the result of unrecognized submillimeter luminous cluster galaxies. Primarily employing optical photometric redshifts, we show that two of the five submillimeter galaxies in this field are consistent with being cluster members, while two are more likely background systems.
Dimensions and Measures in Infinite Iterated Function Systems

The Hausdorff and packing measures and dimensions of the limit sets of iterated function systems generated by countable families of conformal contractions are investigated. Conformal measures for such systems, reflecting geometric properties of the limit set, are introduced, proved to exist, and to be unique. The existence of a unique invariant probability equivalent to the conformal measure is derived. Our methods employ the concepts of the Perron-Frobenius operator, symbolic dynamics on a shift space with an infinite alphabet, and the properties of the above-mentioned ergodic invariant measure. A formula for the Hausdorff dimension of the limit set in terms of the pressure function is derived. Fractal phenomena not exhibited by finite systems are shown to appear in the infinite case. In particular, a variety of conditions are provided for Hausdorff and packing measures to be positive or finite, and a number of examples are described showing the appearance of various possible combinations for these quantities. One example given special attention is the limit set associated to the complex continued fraction expansion—in particular lower and upper estimates for its Hausdorff dimension are given. A large natural class of systems whose limit sets are 'dimensionless in the restricted sense' is described.
Alpha particle heating at comet-solar wind interaction regions

The satellite observations at comet Halley have shown strong heating of solar wind alpha particles over an extended region dominated by high-intensity, low-frequency turbulence. These waves are excited by the water group pickup ions and can energize the solar wind plasma by different heating processes. The alpha particle heating by the Landau damping of kinetic Alfven waves and the transit time damping of low-frequency hydromagnetic waves in this region of high plasma beta are studied in this paper. The Alfven wave heating was shown to be the dominant mechanism for the observed proton heating, but it is found to be insufficient to account for the observed alpha particle heating. The transit time damping due to the interaction of the ions with the electric fields associated with the magnetic field compressions of magnetohydrodynamic waves is found to heat the alpha particles preferentially over the protons. Comparison of the calculated heating times for the transit time damping with the observations from comet Halley shows good agreement. These processes contribute to the thermalization of the solar wind by the conversion of its directed energy into the thermal energy in the transition region at comet-solar wind interaction. comets Giacobini-Zinner and Halley is the presence of high- intensity, low-frequency magnetohydrodynamic (MttD) tur- bulence over an extended region. At comet Giacobini-Zinner the amplitudes of the MttD fluctuations detected by the mag- netometer and plasma instruments aboard the ICE spacecraft
Minimal Gravitomagnetism

We show that Feynman’s proof applies to Newtonian gravitation, implying thus the existence of gravitational analogous of the electric and magnetic ﬁelds and the corresponding Lorentz-like force. Consistency of the formalism require particular properties of the electric and magnetic-like ﬁelds under Galilei transformations, which coincide with those obtained in previous analysis of Galilean electromagnetism.
Early formation of supermassive black holes via dark matter self-interactions

The existence of supermassive black holes at high redshifts (z∼7) is difficult to accommodate in standard astrophysical scenarios. It has been shown that dark matter models with a subdominant self-interacting component are able to produce early seeds for supermassive black holes through the gravothermal catastrophe. Previous studies used a fluid equation approach, requiring some limiting assumptions. Here we reconsider the problem using N-body gravitational simulations starting from the formation of the initial dark matter halo. We consider both elastic and dissipative scattering, and elucidate the interplay between the dark matter microphysics and subsequent accretion of the black hole needed to match the properties of observed high redshift supermassive black holes. We find a region of parameter space in which a small component of self-interacting dark matter can produce the observed high redshift supermassive black holes.
Experimental investigation on the thixotropic effect on the mechanical recovery characteristics of clay–structure interface

Abstract The mechanical characteristics of the soil–structure interface have a crucial impact on the bearing capacity of offshore foundations. The thixotropy-induced strength recovery of remolded soils has a significant effect on the increase in the stability of the foundation. To explore the effects of thixotropy on the recovery characteristics of the soil–structure interfacial shear strength, a self-designed interfacial mechanical characteristic apparatus is designed in this study to perform a series of soil–structure interface tests on clays from the South China Sea and offshore Dalian, respectively. The relationship between the recovery of undrained shear strength and the change of interfacial shear strength is analyzed by the index of shear-resistant coarseness. And the effect mechanism of thixotropy on interfacial shear strength is discussed from the microscopic view. The test results indicated that the rate of increase of the soil–structure interfacial shear strength is higher than that of the undrained shear strength. The particle size index of the soil was found to significantly influence the strength recovery characteristics of the soil–structure interface. A higher clay content will accelerate the development of the interfacial shear strength. This article provides a deep insight into the thixotropic effect on the mechanical properties of the marine soil–structure interface.
Determination of gap defect states in organic bulk heterojunction solar cells from capacitance measurements

Energy distributions density-of-states DOS of defects in the effective band gap of organic bulk heterojunctions are determined by means of capacitance methods. The technique consists of calculating the junction capacitance derivative with respect to the angular frequency of the small voltage perturbation applied to thin film poly3-hexylthiopheneP3HT6,6-phenyl C61-butyric acid methyl ester PCBM solar cells. The analysis, which was performed on blends of different composition, reveals the presence of defect bands exhibiting Gaussian shape located at E 0.38 eV above the highest occupied molecular orbital level of the P3HT. The disorder parameter , which accounts for the broadening of the Gaussian DOS, lies within the range of 49‐66 meV. The total density of defects results of order 10 16 cm 3 . © 2009 American Institute of Physics.
Application of wearable technologies for player motion analysis in racket sports: A systematic review

The use of wearable devices for player motion analysis is becoming a popular method to measure kinematic parameters associated with player techniques in racket sports. This systematic review focused on identifying the current applications of wearable technology for player motion analysis in racket sports (tennis, table tennis, badminton and squash) through two research questions: (1) What are the existing applications of wearable technology for player motion analysis in racket sports? (2) What data analysis methods are used to quantify and evaluate player motion? A comprehensive search of MEDLINE, EMBASE, SPORTDiscus, Scopus, Web of Science, and IEEE databases was undertaken following PRISMA reporting guidelines. Included studies must have only used external wearable technology mounted to either the player or the racket for the potential application of player motion analysis in a racket sport, tested the wearable technology under normal playing conditions and not only focused on detecting/classifying the player's stroke or activity movement. Of the 6616 articles found, a total of 15 studies met the inclusion and exclusion criteria. Tennis and table tennis were the most popular sports researched and inertial measurement units and electromyography sensors were the most common types of sensors used. This review found that wearable devices were mainly used to analyze (1) movement similarities and differences of players at different playing levels, (2) variability in racket, upper limb and joint movement patterns and (3) movement differences associated with different ball spin levels. These technologies can create a new level of accessible personalized training in these sports.
Light hadron spectrum and quark masses from quenched lattice QCD

We present the details of simulations for the light hadron spectrum in quenched QCD carried out on the CP-PACS parallel computer. Simulations are made with the Wilson quark action and the plaquette gauge action on lattices of size ${32}^{3}\ifmmode\times\else\texttimes\fi{}56\char21{}{64}^{3}\ifmmode\times\else\texttimes\fi{}112$ at four values of lattice spacings in the range $a\ensuremath{\approx}0.1\char21{}0.05\mathrm{fm}$ and spatial extent ${L}_{s}a\ensuremath{\approx}3\mathrm{fm}. $ Hadronic observables are calculated at five quark masses corresponding to ${m}_{\mathrm{PS}}{/m}_{V}\ensuremath{\approx}0.75\char21{}0.4,$ assuming the u and d quarks are degenerate, but treating the s quark separately. We find that the presence of quenched chiral singularities is supported from an analysis of the pseudoscalar meson data. The physical values of hadron masses are determined using ${m}_{\ensuremath{\pi}},$ ${m}_{\ensuremath{\rho}},$ and ${m}_{K}$ (or ${m}_{\ensuremath{\varphi}})$ as input to fix the physical scale of lattice spacing and the u, d, and s quark masses. After chiral and continuum extrapolations, the agreement of the calculated mass spectrum with experiment is at a 10% level. In comparison with the statistical accuracy of 1%\char21{}3% and systematic errors of at most 1.7% we have achieved, this demonstrates a failure of the quenched approximation for the hadron spectrum: the hyperfine splitting in the meson sector is too small, and in the baryon sector the octet masses and mass splitting of the decuplet are both smaller than experiment. Light quark masses are calculated using two definitions: the conventional one and the one based on the axial-vector Ward identity. The two results converge toward the continuum limit, yielding ${m}_{\mathrm{ud}}{=4.29(14)}_{\ensuremath{-}0.79}^{+0.51}\mathrm{MeV}$ where the first error is statistical and the second one is systematic due to chiral extrapolation. The s quark mass depends on the strange hadron mass chosen for input: ${m}_{s}{=113.8(2.3)}_{\ensuremath{-}2.9}^{+5.8}\mathrm{MeV}$ from ${m}_{K}$ and ${m}_{s}{=142.3(5.8)}_{\ensuremath{-}0}^{+22.0}\mathrm{MeV}$ from ${m}_{\ensuremath{\varphi}},$ indicating again a failure of the quenched approximation. We obtain the scale of QCD, ${\ensuremath{\Lambda}}_{\overline{\mathrm{MS}}}^{(0)}=219.5(5.4)\mathrm{MeV}$ with ${m}_{\ensuremath{\rho}}$ used as input. An $O(10%)$ deviation from experiment is observed in the pseudoscalar meson decay constants.
Temperature Dependence of the Piezoresistance of High-Purity Silicon and Germanium

The change of resistance in uniaxial compression has been measured for a number of single-crystal specimens of high-re-resistivity $n$- and $p$-type germanium and silicon over the ranges 5\ifmmode^\circ\else\textdegree\fi{} to 350\ifmmode^\circ\else\textdegree\fi{}K (Ge) and 20\ifmmode^\circ\else\textdegree\fi{} to 350\ifmmode^\circ\else\textdegree\fi{}K (Si). For $n$-type material in the orientations giving the large effect\char22{}[110] for $n$-Ge and [100] for $n$-Si\char22{}the piezoresistance is, as predicted by theory, linear in ${T}^{\ensuremath{-}1}$ over most of the temperature range and with a small intercept. It is rather insensitive to impurity scattering. The departure from linearity in ${T}^{\ensuremath{-}1}$ due to the onset of intervalley scattering near room temperature is estimated theoretically; it appears to be just barely detectable for $n$-Ge. The small piezoresistance of [100]-oriented $n$-Ge varies little with temperature over most of the extrinsic range, again in accordance with theory. For $p$-Ge the results suggest that ideally pure material would show a piezo-resistance dominated by a ${T}^{\ensuremath{-}1}$ term for both [110] and [100] orientations. It is shown that this is to be expected theoretically, although the mechanism of piezoresistance for a degenerate band is more complicated than for a many-valley model. However, the results for $p$-type material are, as they should be, much more sensitive to impurity scattering, even the sign of the effect varying with the purity for [100] specimens. For $p$-Si no simple temperature dependence is found, presumably because the spin-orbit splitting of the bands is comparable with $\mathrm{kT}$. At temperatures low enough to condense most of the carriers onto impurity centers, the piezoresistance departs from linearity in ${T}^{\ensuremath{-}1}$ and varies from specimen to specimen. This behavior appears not to be due to impurity scattering; it may be caused in part by inhomogeneities. Surface conduction effects have been observed, but can be eliminated by etching. Neither Hall nor piezoresistance measurements reveal any detectable variation of the ionization energy of donors with strain. No departure of the piezoresistance from linearity in the applied stress has been observed.
Spintronics: Fundamentals and applications

Spintronics, or spin electronics, involves the study of active control and manipulation of spin degrees of freedom in solid-state systems. This article reviews the current status of this subject, including both recent advances and well-established results. The primary focus is on the basic physical principles underlying the generation of carrier spin polarization, spin dynamics, and spin-polarized transport in semiconductors and metals. Spin transport differs from charge transport in that spin is a nonconserved quantity in solids due to spin-orbit and hyperfine coupling. The authors discuss in detail spin decoherence mechanisms in metals and semiconductors. Various theories of spin injection and spin-polarized transport are applied to hybrid structures relevant to spin-based devices and fundamental studies of materials properties. Experimental work is reviewed with the emphasis on projected applications, in which external electric and magnetic fields and illumination by light will be used to control spin and charge dynamics to create new functionalities not feasible or ineffective with conventional electronics.
Measurement of Spectral Emissivity from 2 μ to 15 μ

An accessory designed and constructed for use with the Perkin-Elmer double-beam Model 21 spectrophotometer is described, which permits the measurement of spectral emissivities of opaque materials at room temperatures. The measurements made are of total (specular plus diffuse) spectral reflection. From this value the spectral emissivity is obtained by subtraction from one.The new source consists of a heated enclosure to supply the energy and a twin optical system to lead the respective sample and reference beams into the instrument. Part of this optical system is removable to permit normal operation of the spectrophotometer and replaceable without readjustment. A temperature-controlled water supply is used to cool the sample.A method for extending the use of this equipment to measure emissivities of materials of low conductivities has been outlined.
Particle in a box with a time-dependent δ -function potential

In quantum information processing, one often considers inserting a barrier into a box containing a particle to generate one bit of Shannon entropy. We formulate this problem as a one-dimensional Schrodinger equation with a time-dependent $\delta$-function potential. It is a natural generalization of the particle in a box, a canonical example of quantum mechanics, and we present analytic and numerical investigations on this problem. After deriving an exact Volterra-type integral equation, composed of an infinite sum of modes, we show that approximate formulas with the lowest-frequency modes correctly capture the qualitative behavior of the wave function. If we take into account hundreds of modes, our numerical calculation shows that the quantum adiabatic theorem actually gives a very good approximation even if the barrier height diverges within finite time, as long as it is sufficiently longer than the characteristic time scale of the particle. In particular, if the barrier is slowly inserted at an asymmetric position, the particle is localized by the insertion itself, in accordance with a prediction of the adiabatic theorem. On the other hand, when the barrier is inserted quickly, the wave function becomes rugged after the insertion because of the energy transfer to the particle. Regardless of the position of the barrier, the fast insertion leaves the particle unlocalized so that we can obtain meaningful information by a which-side measurement. Our numerical procedure provides a precise way to calculate the wave function throughout the process, from which one can estimate the amount of this information for an arbitrary insertion protocol.