Miracle-dz/UniFAR-FTUs huggingface dataset:
LATTICE STRUCTURE OF SPACE-TIME

There are a number of answers to this. The first is this. Popper argued that the empirical backing of which people speak is not the evidence which increases the probability of a hypothesis but that which was obtained through sincere attempts to refute it. The second is this. The more corroborated a hypothesis is die more important is the discovery which refutes it (Michelson's experiment, Hertz's photo-electric efFect, etc.). The third is this. Any well corroborated theory (say Maxwell's) must be a first approximation to the theory which supersedes it: the new theory has to explain how the old theory, though false, stood up so well to severe tests (like Hertz's). To conclude: Popper's theory of corroboration is not hit by the paradox of confirmation, but dissolves it by advancing a view of scientific rhinlcing and research as unauthoritarian, imaginative, questioning, and rebellious; a view according to which neither black ravens nor non-black ravens nor even Michelson's experiment confirm, or sanctify, or give authority to a hypothesis. Popper's philosophy is a philosophy of criticism. Corroboration of a theory is merely an appraisal of the way it stood up so far to severe criticism. This appraisal may help those who try to criticise a theory again, for they may wish to know what happened to previous attempts. But even a high degree of corroboration should not discourage the critic. It may even be a challenge.
Effect of stress on the energy levels of the vacancy-oxygen-hydrogen complex in Si

The piezospectroscopic properties of the VOH defect in Si are found using stress Laplace deep level transient spectroscopy (DLTS) and are compared with local density-functional calculations of (i) the acceptor level and its shift under stress, and (ii) the alignment of the neutral center under stress. The theory is able to account for two acceptor levels observed for (100), , and stress even though additional splitting is expected for a defect with static C 1 h symmetry. This is related to (i) a rapid reorientation of the H atom within the defect at temperatures at which the DLTS experiments are carried out, and (ii) the small effect of stress on two orientations of the defect under stress. The theory is also able to give a quantitative account of the alignment of the center. The effect of stress on the reorientation barrier of the defect is also investigated. The reorientation barrier of the defect in its positive charge state is found theoretically to be very small, consistent with the lack of any splitting in the donor level under stress.
Nested Generalized Linear Model with Ordinal Response for Correlated Data

In this paper, we discuss the generalized linear models with ordinal response for correlated data in nested area. Some basic concepts are described, that is nested spatial, threshold model, and cumulative link function. Due to correlated data used for this modeling, Generalized Estimating Eequation (GEE) is used as model parameters estimation method. Nested is shown by the model building and its application on nested spatially data. In this method, some Working Correlation Matrices (WCM) are able to be specified depend on the nature and type of the data. In this study, 3 types of WCM and 2 types of parameters estimation covariance are used to see the results of parameters estimation from these combinations. As a conclusion, independent WCM is appropriate to the data.
Demodulation of Acoustic Signals in Fiber Bragg Grating Ultrasonic Sensors Using Arrayed Waveguide Gratings

In this study, we propose a demodulator for fiber Bragg grating (FBG) ultrasonic sensor array using arrayed waveguide grating (AWG). Wavelength modulation in the FBG center wavelength due to ultrasonic sound pressure is transformed to light intensity modulation at the AWG output channels using the slopes of the AWG pass band. We experimentally demonstrate demodulation on the basis of the proposed principle for an FBG immersed in an ultrasonic cleaner. The effects of the relationship between the center wavelengths of FBG and AWG on demodulated signals are investigated in the experiments.
Nonspreading wave packets

The spreading or nonspreading of wave packets in one‐dimensional linear and quadratic potentials can readily be determined by solving Ehrenfest’s equations. The results for quadratic potentials can be understood in simple intuitive terms by using quantum distribution functions in phase space which, like classical distributions, rotate clocklike in time once per motional cycle. For more complicated situations, such as potentials with quantum energy spacings which are integral multiples of a basic unit, much can be learned instead by studying the quantum recurrence of their time‐dependent wave functions or probability densities.
On elasticity under pressure

Two recently published ways of calculating the elastic constants for a crystal under hydrostatic pressure are compared. They are shown to be equivalent theoretically, though one is more convenient for numerical simulations. A crystal of ferromagnetic iron in the body-centred cubic structure is used as an example for comparing elastic constants calculated with these two methods.
Local symmetry and impossibility of mixed valence in the Falicov-Kimball model

It is pointed out that homogeneously mixed-valent and excitonic insulator phases proposed earlier for the Falicov-Kimball model break a local symmetry of the Hamiltonian. An Elitzur-type proof on the impossibility of spontaneously breaking a local symmetry is given to show that such phases are not possible at nonzero temperature. At zero temperature, the possibility of breaking a local symmetry is demonstrated in a related model, but it is argued that such symmetry breaking does not occur in the Falicov-Kimball model.
Cometary activity in 2060 Chiron

Results of a 2-yr (1988-90) investigation of cometary activity in 2060 Chiron based on CCD photometry and spectroscopy are reported. The photometry observations include a new rotational light curve of Chiron, a newly refined rotation period, recent developments of its long-term photometric behavior and surface brightness profiles, a deep image of the coma of Chiron, and narrowband images at wavelengths ranging from 3200 to 6840 A. The spectroscopic data include moderate resolution CCD spectra (10-20 A FWHM). Major results include the detection of impulsive brightening on a time scale of hours, evidence for a secular change in the blue portion of the reflectivity spectrum of the nucleus, no evidence for Rayleigh scattering in the near ultraviolet, and an upper limit of the column density of CO(+) ions in the coma. 46 refs.
Accretion turnoff and rapid evaporation of very light secondaries in low-mass X-ray binaries

The illumination of companion stars in very low mass X-ray binaries by various kinds of radiation from the neighborhood of the neutron star after accretion has terminated or during accretion is considered. If a neutron star's spun-up period approaches 0.001 s, pulsar kHz radiation can quench accretion by pushing surrounding plasma away from the neutron star, and may leave the companion to be evaporated by the high-energy radiation component expected from an isolated millisecond radiopulsar. Expected accretion-powered MeV gamma-rays and e(+ or -) winds may also be effective in evaporating dwarf companions. Neutron star spin-down energy release may sustain the power in these radiation mechanisms even while accretion falls. Accretion-powered soft X-rays may speed the mass loss of highly evolved dwarf companions, particularly those with a large fraction of carbon and oxygen. 30 references.
Niobium-stress influence on Nb/Al-oxide/Nb Josephson junctions

Niobium‐stress influence on Nb/Al‐oxide/Nb trilayer Josephson‐junction characteristics is studied. Different junction fabrication techniques are examined such as conventional etching and new lift‐off processes. Nb‐film stress, relaxed during trilayer etching, can deteriorate junction quality in etching‐processed junctions smaller than a few micrometers square. Such deterioration does not occur in lift‐off processed junctions even when they are 1 μm square because stress relaxation occurs during trilayer deposition through lift‐off stencils. This new all‐Nb Josephson‐junction fabrication technique produces high‐quality junctions with Rsg/Rnn =24 (Rsg and Rnn are tunnel resistances at 2 and 4 mV, respectively) and a current uniformity of 1.5% for 100 1‐μm‐square junctions connected in series.
Cellular polyethylene-naphthalate ferroelectrets: Foaming in supercritical carbon dioxide, structural and electrical preparation, and resulting piezoelectricity

Polymer foams with electrically charged cellular voids, the so-called ferroelectrets, are soft piezoelectric transducer materials. Several polymers such as polyethylene terephthalate or cyclo-olefin copolymers are under investigation with respect to their suitability as ferroelectrets. Here, the authors report an additional ferroelectret polymer, cellular polyethylene-naphthalate (PEN), which was prepared from commercial uniform polymer films by means of foaming in supercritical carbon dioxide, inflation, biaxial stretching, electrical charging, and metallization. Piezoelectric d33 coefficients of up to 140pC∕N demonstrate the suitability of such cellular PEN films for transducer applications. Their piezoelectricity is partially stable at elevated temperatures as high as 100°C.
The Extragalactic Distance Scale Key Project. V. Photometry of the Brightest Stars in M100 and the Calibration of WFPC2

We present multiepoch VI observations of the brightest stars in the Virgo spiral galaxy M100 obtained with the WFPC2 aboard the Hubble Space Telescope. Particular attention has been given to the WFPC2 calibration process, and a new calibration is presented here. We find that a calibration based on short exposure (t ≤ 60 sec) observations of the galactic globular clusters ω Cen, Pal 4, and NGC 2419 yields results that are in excellent agreement with the calibration of Holtzmann et al. However, a calibration based on longer exposures (t ≥ 1300 s) yields magnitudes that are systematically brighter by 0.05 mag, on average, in both V and I. We have independently employed both the DAOPHOT/ALLFRAME and DoPHOT photometry routines in reducing the M100 data and have found that the two packages yield magnitudes that agree to better than 0.05 mag except for the WFPC2 chip 3 and WFPC2 chip 4 I data. Severe crowding appears to be the problem in the case of the WFPC2 chip 3 data, but we have been unable to determine the source of the discrepancy for the WFPC2 chip 4 I data. We consider the better than 0.05 mag agreement for the other chip/filter combinations to be quite good under the circumstances prevailing in this data set: an undersampled point-spread function (PSF), faint stars, a rapidly varying background, and moderate to severe crowding. A color-magnitude diagram for the brightest stars in M100 is also presented, which shows a plume of bright blue supergiants extending to at least V ~ 23 mag, or MV ~ -8 mag.
Observations of intermediate degree solar oscillations - 1989 April-June

Frequencies, splittings, and line widths from 85 d of full disk Doppler observations of solar p-modes taken between April 4 and June 30, 1989 are presented. Comparison of the present mode parameters with published Big Bear Solar Observatory (BBSO) results yields good agreement in general and is thus a confirmation of their work using an independent instrument and set of analysis routines. Average differences in p-mode frequencies measured by the two experiments in spring-summer 1989 are explained as a result of differences in the exact periods of data collection during a time of rapidly changing solar activity. It is shown that the present a(1) splitting coefficients for p-modes with nu/L less than 45 micro-Hz suffer from a significant systematic error. Evidence is presented to the effect that a detector distortion or alignment problem, not a problem with the power spectra analysis, is the most likely explanation of this a(1) anomaly.
Raman spectroscopic studies on well-defined carbonaceous materials of strong two-dimensional character

Using 514 nm radiation and a careful experimental protocol allowing us to make quantitative intensity analyses, we have examined the first- and second-order Raman spectra of five varieties of graphite. These include single-crystal graphite and highly oriented pyrolytic graphite as references, then two with a significant content of c-axis translation faults introduced through grinding and exfoliation, and a last sample which is purely turbostratic. We show that full c-axis stacking disorder results in a strong increase of the scattered E2g-mode intensity. We have further shown that even in those strongly disordered stacking sequences, but in which the AB sequence persists over only a few layers, the doublet around 2700 cm−1 is resolved. We argue against assigning the peak around 1355 cm−1 to “disorder,” as is so often done, but to the finite in-plane domain size as proposed a number of years ago; moreover, we suggest that this peak is a more sensitive probe of such small domains than is x-ray diffraction.
Confinement of triplet energy on phosphorescent molecules for highly-efficient organic blue-light-emitting devices

We have significantly improved the emission efficiency in an organic light-emitting device (OLED) based on iridium (III)bis[(4,6-di-fluoropheny)-pyridinato-N,C2′]picolinate (FIrpic). To improve the efficiency, 4,4′-bis(9-carbazolyl)-2,2′-dimethyl-biphenyl, which has a high triplet energy, was used as the carrier-transporting host for the emissive layer. The FIrpic-based OLED exhibited a maximum external quantum efficiency of 10.4%, corresponding to a current efficiency of 20.4 cd/A, and a maximum power efficiency of 10.5 lm/W. The efficiency was drastically improved compared to that of a previously reported FIrpic-based OLED. This result indicates that triplet energy is efficiently confined on FIrpic molecules, resulting in the high efficiency.
Growth kinetics and crystal structure of semiconductor nanowires

Theoretical model for the growth of semiconductor nanowires is developed, which enables one to determine the growth conditions under which the formation of nanowires is possible. General expression for the nanowire growth rate as function of its radius and the growth conditions is obtained and analyzed. The model also describes the transformation from cubic to hexagonal crystal phase of nanowires. It is shown that the observed crystal structure is controlled mainly by the growth kinetics. Structural diagrams and probabilities of cubic and hexagonal phase formation are calculated as functions of supersaturation and nanowire radius within the plausible range of material parameters. Numerical estimates for the domains of phase mixing and phase purity are presented and analyzed.
Magnetically driven isentropic compression experiments on the Z accelerator

Isentropic compression experiments (ICE) have been performed on the Z accelerator facility at Sandia National Laboratory. We describe the experimental design that used large magnetic fields to slowly compress samples to pressures in excess of 400 kbar. Velocity wave profile measurements were analyzed to yield isentropic compression equations of state (EOS). The method can also yield material strength properties. We describe magnetohydronamic simulations and results of experiments that used the “square short” configuration to compress copper and discuss ICE EOS experiments that have been performed with this method on tantalum, molybdenum, and beryllium.
Veritas: Status summary 2009

VERITAS is a ground-based gamma-ray observatory that uses the imaging atmospheric Cherenkov technique and operates in the very-high energy (VHE) region of the gamma-ray spectrum from 100 GeV to 50 TeV. The observatory consists of an array of four 12 m-diameter imaging atmospheric Cherenkov telescopes located in southern Arizona, USA. The four-telescope array has been fully operational since September 2007, and over the last two years, VERITAS has been operating with high reliability and sensitivity. It is currently one of the most sensitive VHE observatories. This paper summarizes the status of VERITAS as of October 2009, and describes the detection of several new VHE gamma-ray sources.
Divergent-ray projection method for measuring the flapping angle, lag angle, and torsional angle of a bumblebee wing

A divergent-ray projection (DRP) method was developed for measuring the flapping angle, lag angle, and torsional angle of a bumblebee wing during beating motion. This new method can measure the spatial coordinates of an insect wing by digitizing the images that are projected by two divergent laser rays from different directions. The advantage of the DRP method is its ability to measure those three angles simultaneously using only one high-speed camera. The resolution of the DRP method can be changed easily by adjusting system parameters to meet the needs of different types of objects. The measurement results for these angles of a bumblebee wing prove the effectiveness of the DRP method in studying the flight performance of insects.
Robust adaptive control of uncertain MIMO non-linear systems - feedforward Takagi-Sugeno fuzzy approximation based approach

This paper proposes a robust adaptive controller using a feedforward Takagi-Sugeno (T-S) fuzzy approximator for a class of multi-input multi-output (MIMO) non-linear plants that is highly unknown. Different to typical fuzzy approximation approaches, the desired commands are taken as input variables of a T-S fuzzy system. Meanwhile, the unknown feedforward terms required during steady state are adaptively approximated and compensated. This allows a simpler architecture during implementation and drops the typical boundedness assumption on fuzzy universal approximation errors. Furthermore, according to H/sup /spl infin// control techniques, non-linear damping design, and sliding mode control, the controllers are synthesised to assure either only the disturbance attenuation, the attenuation of both disturbances and estimated fuzzy parameter errors, or globally asymptotic stable tracking. A linear matrix inequality (LMI) technique then provides a straightforward gain design. Finally, numerical simulations are carried out on a two-link robot to illustrate the expected performance.
Spherical aberrations of multipoles

It is demonstrated in this article that for an electromagnetic 2n−pole system with n=odd, the only existing symmetric aberration which could be used to correct the spherical aberrations of a round lens is the order of 2n−3. Thus, a 2n−pole corrector can only be used to cancel the aberration of round lenses of order 2n−3.
Efficacy of aloe Secundiflora crude extract against Candida albicans and Penicillium marneffei

Medicinal plants have been used in production of various drugs singly or in combination and even as principal raw material for the production of other conventional medicines. There are a number of Aloe species that grow wildly in Kenya. Ten mature leaves of Aloe secundiflora were collected and the crude plant extract was obtained and prepared according to Waihenya et al., 2003. It was then tested for antifungal activity against Candida albicans and Penicillium marneffei. In- vitro studies on the efficacy of crude extracts of A. secundiflora on C.albicans and P. marneffei were conducted. The results of the study revealed considerable zones of inhibition of Candida albicans growth caused by Aloe secundiflora crude plant extract on Sabouraoud agar. There was also growth inhibition of the penicillium marneffei which is known to cause infections in immunosuppressed hosts and in non-AIDS patients with hematological malignancies and those receiving immunosuppressive therapy. Our results suggests that, the extract can be used to prevent the aflatoxins caused by Aspergillus species and the superficial mycosis that result from fungal infection and probably any other kind of mycoses. Further studies are required starting with experimental models to establish the in-vivo activity of the crude extract, the active ingredient, dosage and safety of A.secundiflora, before recommending it for clinical use.
On the Stability of Plasma in Static Equilibrium

Criteria useful for the investigation of the stability of a system of charged particles are derived from the Boltzmann equation in the small m/e limit. These criteria are obtained from the examination of the variation of the energy due to a perturbation, when subject to the general constraint that all regular, time‐independent constants of the motion (including the energy) have their equilibrium values.The first‐order variation of the energy vanishes trivially, and the second‐order variation yields a quadratic form in the displacement variable ξ (which may be introduced because of the well‐known properties of this limit). The positive‐definiteness of this form is a sufficient condition for stability.Several theorems are stated comparing stability under the present theory with that under conventional hydromagnetic fluid theories where heat flow along magnetic lines of force is neglected. Generalizations can be made to systems where the effect of collisions is included.
On Simpson's Paradox and the Sure-Thing Principle

Abstract This paradox is the possibility of P(A|B) <P(A|B') even though P(A|B)≥P(A| B') both under the additional condition C and under the complement C' of that condition. Details are given on why this can happen and how extreme the inequalities can be. An example shows that Savage's sure-thing principle (“If you would definitely prefer g to f, either knowing that the event C obtained, or knowing that C did not obtain, then you definitely prefer g to f.”) is not applicable to alternatives f and g that involve sequential operations.
A unified approach to acoustical reflection imaging

A discrete theory is proposed that represents acoustical reflection measurements in terms of a so‐called data matrix. One column of the data matrix is related to one source position; one row is related to one detector position. In the proposed theory, the data matrix is expressed in a sequence of matrix operators. Those operators quantify the physical processes of emission, downward propagation, reflection, upward propagation, and detection in inhomogeneous media. The concept of optimum ‘‘illumination’’ is introduced. Using the matrix formulation, it is shown how to design an experiment that is optimum for a specific target area. The imaging process is formulated in terms of double inversion: one inversion for the downward propagation operator and one inversion for the upward propagation operator. It is shown that double focusing (in emission and in detection) represents an economic version of the double inversion process. The proposed theory is pre‐eminently suited to discuss imaging technology on a conc.