Miracle-dz/UniFAR-FTUs huggingface dataset:
Mössbauer Effect Studies on Lithium Ferrite Substituted with Chromium and Antimony

The effect of Cr3+ concentration on the various hyperfine interactions for the ferrite system Li0.5+tCrxSbtFe2.5-2t-xO4, 0.0 ≤ x ≤ 1.0, x in steps of 0.2 and t = 0.1, have been studied at room temperature using Mossbauer spectroscopy. The isomershift and the quadrupole splitting are almost negligibly influenced by the change in chromium level. The internal nuclear magnetic field, as determined from the Mossbauer spectra and the linewidth are also studied with the variation of composition. The results have been explained on the basis of various models and a cation distribution has been worked out.
Ultralinear bistable electro‐optic polarization modulator

An optical device utilizing optical feedback has been constructed with a Pockels cell and polarizing components. Two modes of operation of the device are demonstrated. Both modes exhibit optical bistability. It is demonstrated that in one mode of operation the nonlinear dependence of the output intensity as a function of an input optical or electrical signal can be made arbitrarily small compared to the linear dependence.
Formulation, optimization, and sensitivity of NitrOMZv1.0, a biogeochemical model of the nitrogen cycle in oceanic oxygen minimum zones

Abstract. Nitrogen (N) plays a central role in marine biogeochemistry by limiting biological productivity in the surface ocean; influencing the cycles of other nutrients, carbon, and oxygen; and controlling oceanic emissions of nitrous oxide (N2O) to the atmosphere. Multiple chemical forms of N are linked together in a dynamic N cycle that is especially active in oxygen minimum zones (OMZs), where high organic matter remineralization and low oxygen concentrations fuel aerobic and anaerobic N transformations. Biogeochemical models used to understand the oceanic N cycle and project its change often employ simple parameterizations of the network of N transformations and omit key intermediary tracers such as nitrite (NO2-) and N2O. Here we present a new model of the oceanic N cycle (Nitrogen cycling in Oxygen Minimum Zones, or NitrOMZ) that resolves N transformation occurring within OMZs and their sensitivity to environmental drivers. The model is designed to be easily coupled to current ocean biogeochemical models by representing the major forms of N as prognostic tracers and parameterizing their transformations as a function of seawater chemistry and organic matter remineralization, with minimal interference in other elemental cycles. We describe the model rationale, formulation, and numerical implementation in a one-dimensional representation of the water column that reproduces typical OMZ conditions. We further detail the optimization of uncertain model parameters against observations from the eastern tropical South Pacific OMZ and evaluate the model's ability to reproduce observed profiles of N tracers and transformation rates in this region. We conclude by describing the model's sensitivity to parameter choices and environmental factors and discussing the model's suitability for ocean biogeochemical studies.
On a New Method of Graduation

Suppose that as a result of observation or experience of some kind we have obtained a set of values of a variable u corresponding to equidistant values of its argument; let these be denoted by u 1, u 2, … un If they have been derived from observations of some natural phenomenon, they will be affected by errors of observation; if they are statistical data derived from the examination of a comparatively small field, they will be affected by irregularities arising from the accidental peculiarities of the field; that is to say, if we examine another field and derive a set of values of u from it, the sets of values of u derived from the two fields will not in general agree with each other In any case, if we form a table of the differences δu 1 = u 2 – u 1, δu 2 = u 3 – u 2, …, δ2 u 1 = δu 2 − δu 1, etc., it will generally be found that these differences are so irregular that the difference-table cannot be used for the purposes to which a difference-table is usually put, viz., finding interpolated values of u, or differential coefficients of u with respect to its argument, or definite integrals involving u; before we can use the difference-tables we must perform a process of “smoothing,” that is to say, we must find another sequence u 1′, u 2′, u 3′, …, un ′, whose terms differ as little as possible from the terms of the sequence u 1, u 2, … un , but which has regular differences. This smoothing process, leading to the formation of u 1′, u 2′ … un ′, is called the graduation or adjustment of the observations.
The Quantum Vacuum: An Introduction to Quantum Electrodynamics

(Chapter Heading): Zero-Point Energy in Early Quantum Theory. The Electromagnetic Vacuum. Some QED Vacuum Effects. Nonrelativistic Theory of Atoms in Vacuum. Interlude: Radiation Reaction. The Vacuum in Quantum Optics. Casimirand van der Waals Forces: Prelude. Casimir and van der Waals Forces: Elaborations. The Dirac Equation. Introduction to Quantum Field Theory. Self-Energies and Renormalization. Feynman Diagrams. Appendices: Oscillator Equation and Absorption Rate. Force onan Atom in a Thermal Field. Derivation of Equation (2.28). Electric Field of Radiation Reaction. Photodetection and Normal Ordering. Transverse and Longitudinal Delta Functions. Lorentz-Invariant Measure. Index.
hstrat: a Python Package for phylogenetic inference on distributed digital evolution populations

Digital evolution systems instantiate evolutionary processes over populations of virtual agents in silico. These programs can serve as rich experimental model systems. Insights from digital evolution experiments expand evolutionary theory, and can often directly improve heuristic optimization techniques (Hernandez, Lalejini, & Dolson, 2022a; Hernandez, Lalejini, & Ofria, 2022). Perfect observability, in particular, enables in silico experiments that would be otherwise impossible in vitro or in vivo. Notably, availability of the full evolutionary history (phylogeny) of a given population enables very powerful analyses (Dolson & Ofria, 2018; Hernandez, Lalejini, & Dolson, 2022b; Shahbandegan et al., 2022).
Bradford Hill's principles of medical statistics

Thank you for reading bradford hills principles of medical statistics. Maybe you have knowledge that, people have look hundreds times for their chosen books like this bradford hills principles of medical statistics, but end up in harmful downloads. Rather than enjoying a good book with a cup of tea in the afternoon, instead they are facing with some infectious virus inside their laptop. bradford hills principles of medical statistics is available in our digital library an online access to it is set as public so you can get it instantly. Our books collection saves in multiple countries, allowing you to get the most less latency time to download any of our books like this one. Merely said, the bradford hills principles of medical statistics is universally compatible with any devices to read.
Using repeated-prevalence data in multi-state modeling of renal replacement therapy

Multi-state models help predict future numbers of patients requiring specific treatments but these models require exhaustive incidence data. Deriving reliable predictions from repeated-prevalence data would be helpful. A new method to model the number of patients that switch between therapeutic modalities using repeated-prevalence data is presented and illustrated. The parameters and goodness of fit obtained with the new method and repeated-prevalence data were compared to those obtained with the classical method and incidence data. The multi-state model parameters’ confidence intervals obtained with annually collected repeated-prevalence data were wider than those obtained with incidence data and six out of nine pairs of confidence intervals did not overlap. However, most parameters were of the same order of magnitude and the predicted patient distributions among various renal replacement therapies were similar regardless of the type of data used. In the absence of incidence data, a multi-state model can still be successfully built with annually collected repeated-prevalence data to predict the numbers of patients requiring specific treatments. This modeling technique can be extended to other chronic diseases.
Combining dependent tests with incomplete repeated measurements

SUMMARY In comparing the effectiveness of two treatments, repeated measurements of the same characteristic are often taken under two or more distinct conditions for each experimental subject. A locally best linear combination of individual test statistics obtained under different conditions is proposed to test the equality of the two treatments. The test procedure allows different patterns of missing observations for the two groups to be compared. Special cases such as combining Wilcoxon tests, t tests and 2 x 2 tables are discussed in detail with real examples.
Alternative Variance-Ratio Tests Using Ranks and Signs

This article proposes using variance-ratio tests based on the ranks and signs of a time series to test the null that the series is a martingale difference sequence. Unlike conventional variance-ratio tests, these tests can be exact. In Monte Carlo simulations, I find that they can also be more powerful than conventional variance-ratio tests. I apply the proposed tests to five exchange-rate series and find that they are capable of detecting violations of the martingale hypothesis for all five series, whereas conventional variance-ratio tests yield ambiguous results.
Lower bound limit analysis of cohesive‐frictional materials using second‐order cone programming

The formulation of limit analysis by means of the finite element method leads to an optimization problem with a large number of variables and constraints. Here we present a method for obtaining strict lower bound solutions using second‐order cone programming (SOCP), for which efficient primal‐dual interior‐point algorithms have recently been developed. Following a review of previous work, we provide a brief introduction to SOCP and describe how lower bound limit analysis can be formulated in this way. Some methods for exploiting the data structure of the problem are also described, including an efficient strategy for detecting and removing linearly dependent constraints at the assembly stage. The benefits of employing SOCP are then illustrated with numerical examples. Through the use of an effective algorithm/software, very large optimization problems with up to 700 000 variables are solved in minutes on a desktop machine. The numerical examples concern plane strain conditions and the Mohr–Coulomb criterion, however we show that SOCP can also be applied to any other problem of lower bound limit analysis involving a yield function with a conic quadratic form (notable examples being the Drucker–Prager criterion in 2D or 3D, and Nielsen's criterion for plates). Copyright © 2005 John Wiley & Sons, Ltd.
Spectrum and term system of neutral nickel, Ni I

Spectra of nickel, emitted from hollow cathode discharges, have been recorded in the region 1700-55 000 A (58 800-1800 cm−1). Fourier transform spectrometers were used above 1800 A, yielding very high accuracy and resolution. The number of classified Ni I lines has increased from 1071 to 1996. 289 of the lines have been resolved in 2-4 isotope components. The term system derived from the observations comprises 286 energy levels. The term structure and the coupling conditions have been studied by means of ab initio and parametric theory.
Directly electrospun ultrafine nanofibres with Cu grid spinneret

A hydrophobic Cu grid was used as an electrospinning spinneret to fabricate ultrafine organic nanofibres. The Cu grid used in this study was that which holds samples in TEM. Due to the hydrophobic surface and larger contact angle of the electrospinning solution on the Cu grid surface, the solution flow was divided into several finer ones by the holes in the Cu grid instead of accumulating. Each finer flow was stretched into individual jets and established a multi-jet mode by the electrical field force. The finer jets played an important role in decreasing the diameter of the nanofibre. The charge repulsion force among charged jets enhanced the whipping instability motion of the liquid jets, which improved the uniformity of the nanofibre and decreased the diameter of the nanofibre. An ultrafine uniform nanofibre of diameter less than 80 nm could be fabricated directly with the novel Cu grid spinneret without any additive. This study provided a unique way to promote the application of one-dimensional organic nanostructures in micro/nanosystems.
Nonlinear PID control of a six-DOF parallel manipulator

A nonlinear proportional integral derivative (N-PID) algorithm in linkspace is proposed to realise high precision tracking control of a general six-DOF parallel manipulator. In practice, the performance of the controlled system is limited by how to pick out the differential signals of the noncontinuous measured signals with stochastic noise. Therefore, the developed N-PID controller uses two nonlinear tracking differentiators to yield high quality differential signals in the presence of disturbances and measurement noise. A nonlinear combination of proportional, integral and derivative action on the control error is used to synthesise the control law for enhanced performance in areas such as increased damping and reduced tracking error. Experimental results indicate that the nonlinear control method is easy for the engineer to implemente and achieves a superior performance.
Design, Manufacturing, and Commissioning of BIRCAM (Bootes InfraRed CAMera)

This paper covers the various aspect of design, manufacturing and commissioning of the infrared camera BIRCAM, installed at BOOTES-IR, the 60 cm robotic infrared telescope at Sierra Nevada Observatory (OSN, Granada, Spain). We describe how we achieved a quality astronomical image, moving from the scientific requirements.
The Variabilities of the Soft and Hard X-ray Components of NGC 7314 and NGC 7582 and the Distribution of Absorbing Matter in Type II AGNs

ASCA observations of the two Type II AGNs, NGC 7314 and NGC 7582, show clear variations in the broad X-ray band (0.4 –10 keV) on short timescales ∼10 4 s. Spectral analysis indicates that they both have an absorbed hard X-ray component and an unabsorbed soft ``excess" component. To clarify the origin of the latter, we made a cross-correlation analysis of the two components. The results show that, for NGC 7314, the soft X-ray variability is proportional to that of the hard X-ray component. This indicates that the active nucleus of NGC 7314 must be partially covered and so the soft emission is a ``leaking" of the variable hard component. For NGC 7582, there is no detectable variability in the soft component, although there is a definite one in the hard component. This indicates that the variable nucleus of NGC 7582 must be fully blocked by absorbing matter, and the soft emission is most likely the scattered component predicted by the AGN unified model.
Modelling of unsteady electromagnetically driven recirculating melt flows

A numerical model for the recirculating flow of an electromagnetically stirred iron melt in a cylindrical induction furnace crucible is presented. Due to the parameters of the problem, the full set of magnetohydrodynamic flow equations decouples into magnetic and hydrodynamic parts. The diffusion approach of the magnetic vector potential describes the magnetic part of the model. The hydrodynamic part of the model is based on the unsteady ensemble-averaged Navier–Stokes equations in conjunction with a Reynolds stress turbulence model. Such an approach is commonly termed the unsteady Reynolds averaged approach. Here the influence of the electromagnetic field is included by means of a Lorentz force density.The diffusion equation is solved by a finite-element method. The Lorentz force density in the melt can be deduced from the results. Then the unsteady Reynolds averaged equations are solved by the finite-volume method.The results of the unsteady Reynolds averaged approach are analysed and compared to the results of the steady Reynolds averaged equations of the flow under consideration and to experimental results obtained from other studies. It is found that the toroidal vortex pair, which is the dominating structure within the flow, interacts by intermittent streamline connections.
Inverse membrane problems in elasticity

The inverse elasticity problem of determining the undeformed, deflated, configuration of a nonlinear elastic membrane, given the deformed configuration enclosing an incompressible fluid under known pressure, is considered. It is shown that, in practical cases, it is enough to determine only the undeformed metric tensor, and it is also shown how the two- and three-dimensional cases are fundamentally different. For the three-dimensional case, we set up and classify the partial differential equations to be solved, prove existence of an undeformed state given an undeformed metric and study the axisymmetric case in detail.
A kinetic theory analysis on the heat transfer in hard drive air bearing

In this article, a generalized model for viscous heat generation and heat transfer in the air bearing of a hard drive is developed based on the linearized Boltzmann equation. It is found that the heat flux between the slider and the disk can be separated into four parts: heat conduction, viscous dissipation contributed by Couette flow, viscous dissipation from Poiseuille flow, and combined contribution from Couette flow and Poiseuille flow. Universal functions are obtained so that viscous dissipation and heat conduction can be determined accurately. Comparisons with continuum models reveal significant deficiencies existing in current models in use.
Energy-Based Long-Range Path Planning for Soaring-Capable Unmanned Aerial Vehicles

To enable long-distance, long-duration flights by small soaring-capable uninhabited aircraft, a graph-based method for planning energy-efficient trajectories over a set of waypoints is presented. It introduces the energy map, which is an upper bound on the minimum energy required to reach a goal from anywhere in the environment while accounting for arbitrary three-dimensional wind fields. The energy map provides the path to the goal as a sequence of waypoints, the optimal speeds to fly for each segment between waypoints, and the heading required to fly along a segment. Trajectories computed using the energy map are compared with trajectories planned using an A * -based approach. Results are presented for simple wind fields representative of orographic lift. Finally a high-fidelity numerical simulation of a realistic wind field (ridge lift and wave over complex terrain) is used as a test case. The energy-map approach is shown to perform very well without the need for the heuristics associated with A * .
Nonstationary H∞ dynamic output feedback control for discrete‐time Markov jump linear systems with actuator and sensor saturations

This paper is concerned with the nonstationary dynamic output feedback control problem for a class of discrete‐time Markov jump linear systems (MJLSs) under simultaneous consideration of actuator and sensor saturations. The so‐called nonstationary controllers dominated by two other different piecewise‐stationary Markov chains are introduced, making the designed controllers not only mode‐dependent but also dependent on other variations associated with the mode transitions in the original MJLSs. The sufficient conditions formulated in terms of bilinear matrix inequalities for the H∞ control problem are established such that the resulting closed‐loop system is stochastically stable and achieves a prescribed H∞ noise attenuation level. A suboptimal algorithm with line search is exploited to solve for the associated controller gains. Effectiveness of the developed theoretical results is verified via a numerical example. Copyright © 2015 John Wiley & Sons, Ltd.
Matter wave optics perspective at molecular photoionization: K-shell photoionization and Auger decay of N2

In this paper, we shed new light on the molecular photoionization of a diatomic molecule. We will elaborate the differences and analogy between a quantum optical and light–matter interaction approach in a study of K-shell photoionization of N2 in which the photoelectron and the subsequently emitted Auger electron are both measured in coincidence in the body fixed frame of the molecule. The two electrons form an entangled state inside a double slit. By changing the photon energy we create different types of interference in the photoelectron and the Auger electron wave.
Relationship Between the Cox, Lehmann, Weibull, and Accelerated Lifetime Models

Cox and Oakes (1984) claimed that a model satisfies the accelerated lifetime (AL) model and the proportional hazards (PH) model iff it is Weibull. Doksum and Nabeya (1984) constructed a family of analytic non Weibull survival functions that satisfies both the PH and AL models. We further study the relationship between the PH, AL, Lehmann, and Weibull models without the restriction of absolute continuity.
Bulging Modes of Circular Bottom Plates in Rigid Cylindrical Containers Filled with a Liquid

In this article the free vibrations of the bottom plate of an otherwise rigid circular cylindrical tank filled with liquid are studied, considering only the bulging modes (when the amplitude of the plate displacement is predominant with respect to that of the free surface). The tank axis is vertical, thus the free liquid surface is orthogonal to the tank axis. The liquid is assumed to be inviscid, and the contribution of the free surface waves to the dynamic pressure on the free liquid surface is neglected. Wet and dry mode shapes of the plate are assumed to be the same, so that the natural frequencies are obtained by using the nondimensionalized added virtual mass incremental (NA VMI) factors and the modal properties of dry plates. This simplifies computations compared to other existing theoretical approaches. NAVMI factors express the nondimensionalized ratio between the reference kinetic energy of the liquid and that of the plate and have the advantage that, due to their nondimensional form, they can be computed once and for all. Numerical results for simply supported and clamped bottom plates, as well as for supported plates with an elastic moment edge constraint are given. For more accurate results, and to exceed the limits of the assumed modes approach, the Rayleigh-Ritz method is applied and results are compared to those obtained by using the NAVMI factors and other existing methods in the literature.
Cross Correlation Method Application to Prompt Fission Neutron Investigation

Do The prompt neutron emission in spontaneous fission of 252Cf has been investigated applying cross correlation method and digital signal processing algorithms. A new mathematical approach for neutron/gamma pulse shape separation was developed and implemented for prompt fission neutron (PFN) time-of-flight measurement. The main goal was development of automated data analysis algorithms and procedures for data analysis with minimum human intervention. Experimental data was taken with a twin Frisch-grid ionization chamber and a NE213-equivalent neutron detector in an experimental setup similar to well work of C. Budtz-Jorgensen and H. -H. Knitter [1]. About 2*107 fission events were registered with 2*105 neutron/gamma detection in coincidence with fission fragments. Fission fragment kinetic energy, mass and angular distribution, neutron time-of-flight and pulse shape have been investigated using a 12 bit waveform digitizer.