Atmospheric turbulence characterization with the Keck adaptive optics systems. I. Open-loop data

We present a detailed investigation of different methods of the characterization of atmospheric turbulence with the adaptive optics systems of the W. M. Keck Observatory. The main problems of such a characterization are the separation of instrumental and atmospheric effects and the accurate calibration of the devices involved. Therefore we mostly describe the practical issues of the analysis. We show that two methods, the analysis of differential image motion structure functions and the Zernike decomposition of the wave-front phase, produce values of the atmospheric coherence length r0 that are in excellent agreement with results from long-exposure images. The main error source is the calibration of the wave-front sensor. Values determined for the outer scale L0 are consistent between the methods and with typical L0 values found at other sites, that is, of the order of tens of meters.     

Fault detection and identification in dynamic systems with noisy data and parameter/modeling uncertainties

A probabilistic approach is presented which can be used for the estimation of system parameters and unmonitored state variables towards model-based fault diagnosis in dynamic systems. The method can be used with any type of input–output model and can accommodate noisy data and/or parameter/modeling uncertainties. The methodology is based on Markovian representation of system dynamics in discretized state space. The example system used for the illustration of the methodology focuses on the intake, fueling, combustion and exhaust components of internal combustion engines. The results show that the methodology is capable of estimating the system parameters and tracking the unmonitored dynamic variables within user-specified magnitude intervals (which may reflect noise in the monitored data, random changes in the parameters or modeling uncertainties in general) within data collection time and hence has potential for on-line implementation.     

Direct numerical inversion method for kinetic ellipsometric data. I. Presentation of the method and numerical evaluation

A direct numerical inversion method for the determination of the refractive index and the thickness of the outermost layer of a thin transparent film on top of a multilayer has been developed. This method is based on a second-order Taylor decomposition of the coefficients of the Abelès matrices of the newly grown layer. The variations of the real-time spectroscopic ellipsometry data are expressed as polynomial fuctions depending on the dielectric constant and the thickness of the newly grown layer. The method is fast, capable of single-wavelength and multiwavelength inversion of continuous as well as discontinuous-index profiles, and can be adapted to many different polarimetric instruments.     

Estimating weak ratiometric signals in imaging data. I. Dual-channel data

Ratiometric fluorescent indicators are becoming increasingly prevalent in many areas of biology. They are used for making quantitative measurements of intracellular free calcium both in vitro and in vivo, as well as measuring membrane potentials, pH, and other important physiological variables of interest to researchers in many subfields. Often, functional changes in the fluorescent yield of ratiometric indicators are small, and the signal-to-noise ratio (SNR) is of order unity or less. In particular, variability in the denominator of the ratio can lead to very poor ratio estimates. We present a statistical optimization method for objectively detecting and estimating ratiometric signals in dual-wavelength measurements of fluorescent, ratiometric indicators that improves on standard methods. With the use of an appropriate statistical model for ratiometric signals and by taking the pixel-pixel covariance of an imaging dataset into account, we are able to extract user-independent spatiotemporal information that retains high resolution in both space and time.     

3D laser ultramicroscopy: A method for nondestructive characterization of micro- and nanoinclusions in high-purity materials for fiber and power optics

This paper describes a 3D laser ultramicroscopy technique and apparatus for the nondestructive characterization of heterophase inclusions in bulk high-purity materials for fiber and power optics. In this technique, the concentration and size of inclusions undetectable by optical microscopy are determined using CCD detection of the light scattered by them in a direction normal to the incident laser beam at wavelengths from 0.63 to 0.98 μm. The detection limit of the technique in terms of inclusion size is n × (10–100) nm, the range of detectable number concentrations is 1–10¹¹ cm^?3, and the scan depth in the sample is ～1 cm. Its performance has been evaluated using test systems. The potential of the technique is illustrated by the dispersion analysis of promising materials for IR fiber-optic applications.     

Identification method of structural defects in glass fiber fabric/epoxy resin laminate

We present the experimental methods proposed for the identification of structural defects of the laminate constituted of 12 layers of glass fiber fabric/epoxy resin. Two techniques of control were used to analyze the principal structural defects (local or global disorientation). The first technique provides a superficial observation (macroscopic analysis) of the superior and lower surfaces of each layer, while the second one ensures internal observation (microscopic analysis) of different layers after pyrolysis of the matrix (delamination of the laminate).     

Novel method for determination of critical fiber length in short fiber carbon/carbon composites by double lap joint

A novel approach is introduced for the experimental determination of critical fiber length in carbon fiber reinforced carbon (CFRC) composites. Critical fiber length is investigated using double lap joint samples. The transition of failure mode from bonding failure to fiber fraction with increasing overlap length correlates with the critical fiber length. Tested overlap lengths were in the range of 4–100 mm. For CFRC at hand, failure mode changes at an overlap length of 26 ± 2 mm. Hence critical fiber length is derived as l_c = 52 ± 4 mm.     

Effect of interfacial adhesion and statistical fiber strength on tensile strength of unidirectional glass fiber/epoxy composites. Part I: experiment results

The effects of fiber surface treatment on ultimate tensile strength (UTS) of unidirectional (UD) epoxy resin matrix composites are examined experimentally. The interfacial shear strength (IFSS) and statistical fiber strength are significantly altered by five different kinds of surface treatments, which are: (a) unsized and untreated; (b) γ-glycidoxypropyltrimethoxysilane (γ-GPS); (c) γ-methacryloxypropyltrimethoxysilane (γ-MPS); (d) mixture of γ-aminoxypropyltrimethoxysilane (γ-APS), film former (urethane) and lubricant (paraffin); and (e) urethane-sized. The maximum UTS is obtained for the relatively strong interfacial adhesion (glass/γ-MPS/epoxy) but not for the strongest interfacial adhesion (glass/γ-GPS/epoxy). The governing micro-damage mode around a broken fiber and the interface region is matrix cracking for γ-GPS treated fibers, and a combination of interfacial debonding and matrix cracking for γ-MPS treated fibers. The micro-damage mode related to the interfacial adhesion strongly affects the fracture process, and thus the UTS of UD composites. The results also indicate that the interfacial adhesion can be optimized for effective utilization of fiber strength for fiber composites. A parameter called “efficiency ratio” of fiber strength in UD composites is proposed to examine and distinguish different effects of IFSS and fiber strength on the UTS of UD composites. The experimental results show that improved UTS of UD composites due to surface treatments mainly result from the increase in fiber strength but not from the modified interface.     

Generalized quasi mode theory of macroscopic canonical quantization in cavity quantum electrodynamics and quantum optics I. Theory

Abstract

The quasi mode theory of macroscopic quantization in quantum optics and cavity QED developed by Dalton, Barnett and Knight is generalized. This generalization allows for cases in which two or more quasi permittivities, along with their associated mode functions, are needed to describe the classical optics device. It brings problems such as reflection and refraction at a dielectric boundary, the linear coupler, and the coupling of two optical cavities within the scope of the theory. For the most part, the results that are obtained here are simple generalizations of those obtained in previous work. However the coupling constants, which are of great importance in applications of the theory, are shown to contain significant additional terms which cannot be ‘guessed’ from the simpler forms. The expressions for the coupling constants suggest that the critical factor in determining the strength of coupling between a pair of quasi modes is their degree of spatial overlap. In an accompanying paper a fully quantum theoretic derivation of the laws of reflection and refraction at a boundary is given as an illustration of the generalized theory. The quasi mode picture of this process involves the annihilation of a photon travelling in the incident region quasi mode, and the subsequent creation of a photon in either the incident region or transmitted region quasi modes.     

碳纤维/树脂复合材料多钉连接钉载系数测试方法

为解决由于碳纤维/树脂复合材料多钉连接结构中钉载分配状态和测试方法不同导致的钉载系数测试分散性不明确的问题,针对应变片和钉载矢量传感器两种测试方法,提出基于不确定度理论的钉载系数相对测量不确定度的计算模型,并计算两种测试方法对碳纤维X850/树脂复合材料单剪、双剪连接结构钉载系数的相对测量不确定度。结果表明,应变片测试方法中,单剪结构钉载系数无法准确测量,双剪结构钉载系数相对测量不确定度通常超过2.8%,且随结构中螺栓数目和应变片贴片角度偏差的增加而增大;钉载矢量传感器测试方法中,单剪、双剪结构钉载系数均可测试,且针对任意螺栓数目结构,其钉载系数相对测量不确定度最大不超过1.5%。      

Sensitivity of the two-dimensional electric potential/resistance method for damage monitoring in carbon fiber polymer-matrix composite

The two-dimensional electric potential/resistance method is much less sensitive than the one-dimensional resistance method for damage monitoring in carbon fiber polymer-matrix composite. In the two-dimensional method, the resistance measurement is more sensitive than the potential gradient measurement. The sensitivity of the potential method is enhanced when the potential gradient line is close to the current line.     

Monochromator-induced glitches in EXAFS data I. Test of the model for linearly tapered samples

When EXAFS samples are slightly nonuniform in thickness, spikes, referred to as “glitches”, are observed in the data. Such features are intrinsic to data collected using crystal monochromators. We have recently developed a model to show why such features, persist in ratioed data. Here we test the predictions for linearly tapered samples. Our results suggest that the glitch mplitude can be significantly reduced by taking a second spectrum with the sample inverted, and then averaging the two spectra.     

A method of defining steady-state radiative-Conductive heat transfer in a plane-Parallel layer. I

A method is given for solving for the steady-state radiative-conductive heat transfer in a planar layer of a medium; the radiation flux is represented by means of Green's functions.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 31, No. 4, pp. 710–715, October, 1976.     

Determination of the soret coefficient in a thermodiffusion column by the transient method. I

A method of determining the Soret coefficient for binary mixtures is proposed and suggestions are made on how to use thermodiffusion columns for this purpose.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 26, No. 3, pp. 436–445, March, 1974.     

Stability indicating TLC method for the quantification of tinidazole in pharmaceutical dosage form - I.V. Fluid

Tinidazole was separated from degradation products formed in large volume parenteral preparations by TLC method using Silica gel GF254 as stationary phase and Chloroform - Methanol (9:1) mixture as mobile phase. Subsequently extracted with ethyl alcohol and estimated by measuring absorbance at 310nm using standard calibration curve. Recovery was 98 to 102% and the co-efficient of variation was 2.1%.     

Stability indicating TLC method for the quantification of tinidazole in pharmaceutical dosage form - I.V. Fluid

Abstract

Tinidazole was separated from degradation products formed in large volume parenteral preparations by TLC method using Silica gel GF254 as stationary phase and Chloroform - Methanol (9:1) mixture as mobile phase. Subsequently extracted with ethyl alcohol and estimated by measuring absorbance at 310nm using standard calibration curve. Recovery was 98 to 102% and the co-efficient of variation was 2.1%.     

Impulse response solution to the three-dimensional vector radiative transfer equation in atmosphere-ocean systems. I. Monte Carlo method

We have developed a powerful 3D Monte Carlo code, as part of the Radiance in a Dynamic Ocean (RaDyO) project, which can compute the complete effective Mueller matrix at any detector position in a completely inhomogeneous turbid medium, in particular, a coupled atmosphere-ocean system. The light source can be either passive or active. If the light source is a beam of light, the effective Mueller matrix can be viewed as the complete impulse response Green matrix for the turbid medium. The impulse response Green matrix gives us an insightful way to see how each region of a turbid medium affects every other region. The present code is validated with the multicomponent approach for a plane-parallel system and the spherical harmonic discrete ordinate method for the 3D scalar radiative transfer system. Furthermore, the impulse response relation for a box-type cloud model is studied. This 3D Monte Carlo code will be used to generate impulse response Green matrices for the atmosphere and ocean, which act as inputs to a hybrid matrix operator-Monte Carlo method. The hybrid matrix operator-Monte Carlo method will be presented in part II of this paper.