Reflectance and Reflection

Figure 1 and 2 demonstrate the linear relationship of trash and dust content (wet assay) to both In (1/reflectance) and reflectance. The coefficient of determination (r ) is the percentage of total variation explained by the regression. For example, percentage of unexplained variation (i.e. 1.4% for y = trash content and 3.8% for y = dust content (wet assay) with x = reflectance) is indicative of a significant relationship between particulate content in cotton and In R. A small unexplained variation was observed for all of the trash and dust content functions in Table III. Airborne dust unexplained variation, however, was poorer precision of the measurement for the five cottons investigated was not reported. 

This technique involves a reflectivity measurement, therefore, the Kramers-Kroenig transform is required to convert the resulting reflectance spectrum to a pseud-absorbance spectrum. This is a simple procedure for normal incidence measurements. Optically thick samples are desirable. Additional interfaces, such as air pockets, in the sample can induce reflection absorption bands - resulting in a spectrum of convolved reflection and reflection absorption features. In some cases, optically smooth protein and starch films can be prepared (without cryogenic slicing),... 

J Polcin and WH Rapson. Spectrophotometric Study of Wood Chromophores In Situ. H. Determination of the Absorption Spectrum of Lignin from Reflectance and Reflectivity... 

The analysis of the structure of the meridional reflections and reflections in the x-ray fiber pattons of PDTHB fiber with a high M = 42,000) [65] (a highly oriented fiber was annealed at 220°C for 6 h in a vacuum) showed that the average value of the crystal lattice constant C was 57.7 A. Since the length... 

Powders, or solid reduced to particles, can be examined as a thin paste or mull by grinding the pulverized solid (about 9 mg) in a greasy liquid medium. The suspension is pressed into an annular groove in a demountable cell. Multiple reflections and reflections from the particles are reduced by grinding particles to a size an order of magnitude less than the analytic wavelength... 

One web site (http //ricmorte.com/index.php/light-a-colour/optics/reflectance-a-reflectivity, accessed September 2014) makes the distinction between reflectivity and reflectance Reflectivity is a property of the bulk material, reflectance is a property of a specific sample. The reflectivity of silver (at a specific wavelength) is about 90%, but a silver film 25 nm thick has a reflectance of about 10%, and, if 100 nm thick, the reflectance approaches the reflectivity of bulk silver. 

When there are sufficient data at different temperatures, the temperature dependence of the parameters is reflected in the confidence ellipses (Bryson and Ho, 1969 Draper and Smith,... 

Appendix C-6 gives parameters for all the condensable binary systems we have here investigated literature references are also given for experimental data. Parameters given are for each set of data analyzed they often reflect in temperature (or pressure) range, number of data points, and experimental accuracy. Best calculated results are usually obtained when the parameters are obtained from experimental data at conditions of temperature, pressure, and composition close to those where the calculations are performed. However, sometimes, if the experimental data at these conditions are of low quality, better calculated results may be obtained with parameters obtained from good experimental data measured at other conditions. 

Equation (F.l) shows that each stream makes a contribution to total heat transfer area defined only by its duty, position in the composite curves, and its h value. This contribution to area means also a contribution to capital cost. If, for example, a corrosive stream requires special materials of construction, it will have a greater contribution to capital cost than a similar noncorrosive stream. If only one cost law is to be used for a network comprising mixed materials of construction, the area contribution of streams requiring special materials must somehow increase. One way this may be done is by weighting the heat transfer coefficients to reflect the cost of the material the stream requires. 

The term p is a reaction constant and is mathematically evaluated for a particular reaction by plotting log kjkQ against a. The slope of the straight lines is p, and reflects the sensitivity of the reaction under study to effects of substituents. The value of p is obviously affected by temperature, solvent changes, etc. 

TTie calculation of partial fugacltles requires knowing the derivatives of thermodynamic quantities with respect to the compositions and to arrive at a mathematical model reflecting physical reality. 

For vehicles, special attention is most often focused on the knocking potential encountered at high motor speeds in excess of 4000 rpm for which the consequences from the mechanical point of view are considerable and lead very often to mechanical failure such as broken valves or pistons, and rupture of the cylinder head gasket. Between RON and MON, it is the latter which better reflects the tendency to knock at high speeds. Conversely, RON gives the best prediction of the tendency to knock at low engine speeds of 1500 to 2500 rpm. 

The experimental conditions used to determine the CFPP do not exactly reflect those observed in vehicles the differences are due to the spaces in the filter mesh which are much larger in the laboratory filter, the back-pressure and the cooling rate. Also, research is continuing on procedures that are more representative of the actual behavior of diesel fuel in a vehicle and which correlate better with the temperature said to be operability , the threshold value for the Incident. In 1993, the CEN looked at two new methods, one called SFPP proposed by Exxon Chemicals (David et al., 1993), the other called AGELFI and recommended by Agip, Elf and Fina (Hamon et al., 1993). 

The basics of the method are simple. Reflections occur at all layers in the subsurface where an appreciable change in acoustic impedance is seen by the propagating wave. This acoustic impedance is the product of the sonic velocity and density of the formation. There are actually different wave types that propagate in solid rock, but the first arrival (i.e. fastest ray path) is normally the compressional or P wave. The two attributes that are measured are... 

Of course the typical seismic trace has many hundreds of reflections in it, all the way down from the surface to the deepest times measured. These days, engineers and geologists prefer to see the seismic in terms of the acoustic impedance rather than reflection data and this can be obtained by inversion from the seismic volume. Aseismic volume is made up of hundreds of thousands of traces. 

Migration is both focusing and relocation of the reflection energy. Each zero-offset trace contains reflections that originate at different subsurface points with increasing depth (Fig a) sometimes hundreds of m s away from the surface location. Flowever the reflections are posted at the surface location of the zero-offset trace. Migration compensates for the mislocation due to the bent raypaths. 

In the future, it is expected to be possible to make more routine use of additional wave types, specifically shear or S waves (polarised to horizontal and vertical components) which have a transverse mode of propagation, and are sensitive to a different set of rock properties than P waves. The potential then exists for increasing the number of independent attributes measured in reflection surveys and increasing the resolution of the subsurface image. 

To assess potential yield and maturity of source rocks and classify those according to their vitrinite reflectance . 

Certain key stages in the EIA process have been adopted by many countries. These broad stages reflect what is considered to be good practice within environmental assessment and include ... 

Black oils are a common category of reservoir fluids, and are similar to volatile oils in behaviour, except that they contain a lower fraction of volatile components and therefore require a much larger pressure drop below the bubble point before significant volumes of gas are released from solution. This is reflected by the position of the iso-vol lines in the phase diagram, where the lines of low liquid percentage are grouped around the dew point line. 

When an oil or gas field has just been discovered, the quality of the information available about the well stream may be sparse, and the amount of detail put into the process design should reflect this. However, early models of the process along with broad cost estimates are needed to progress, and both design detail and cost ranges narrow as projects develop through the feasibility study and field development planning phases (see Section 12.0 for a description of project phases). 

Gas processing facilities generally work best at between 10 and 100 bar. At low pressure, vessels have to be large to operate effectively, whereas at higher pressures facilities can be smaller but vessel walls and piping systems must be thicker. Optimum recovery of heavy hydrocarbons is achieved between 20 bar and 40 bar. Long distance pipeline pressures may reach 150 bar and reinjection pressure can be as high as 700 bar. The gas process line will reflect gas quality and pressure as well as delivery specifications. 

Providing the land surfaoe above a reservoir is relatively flat, it is generally cheaper to drill and maintain a vertical well than to access a reservoir from a location that requires a deviated borehole. In unpopulated areas such as desert or jungle looations It is common to find that the pattern of wellheads at surface closely reflects the pattern In which wells penetrate the reservoir. However, in many eases constraints will be planed on drill site availability as a result of housing, environmental concerns or topography. In such conditions wells may be drilled in clusters from one or a number of sites as elose as possible to the surface location of the reservoir. 

Although a single project manager may direct activities throughout a project life, he or she will normally be supported by a project team whose oomposition should reflect the type of project and the experience levels of both company and contractor personnel. The make up and size of the team may change over the life of a project to match the prevailing activity levels in each particular section of the project. 

At each phase of a project cost information is required to enable decisions to be taken. In the conceptual phase these estimates may be very approximate (e.g. + 35% accuracy), reflecting the degree of uncertainty regarding both reservoir development and surface options. As the project becomes better defined the accuracy of estimates should improve. 

Minimum risk estimates are sometimes used to quantify either maximum exposure in monetary terms or, in the case of an annual work plan containing multiple projects, to help determine the proportion of firm projects. Firm projects are those which have budget cover even if costs overrun. A minimum risk estimate is one with little or no probability of overrun, and can be used to reflect the risk associated with very complex or novel projects. 

The proflt-to-investmentratio (PIR) may be defined in many ways, and is most meaningful when deflated and discounted. On an undeflated and undiscounted basis, the PIR may be defined as the ratio of the cumulative cash surplus to the capital investment. This indicates the return on capital investment of the project, is simple to calculate, but does not reflect the timing of the income/investment in the project. 

In the above example, the discount rate used was the annual compound interest rate offered by the bank. In business investment opportunities the appropriate discount rate is the cost of capital to the company. This may be calculated in different ways, but should always reflect how much it costs the oil company to borrow the money which it uses to invest in its projects. This may be a weighted average of the cost of the share capital and loan capital of a company. 

The demand for domestic gas changes seasonally in temperate climates, and production levels reflect this change. For example a sudden cold day in Northern Europe causes a sharply increased requirement for gas, and gas sales contracts in this region will allow the purchaser to demand an instant increase (up to a certain maximum) from the supplier. To safeguard for seasonal swings, imported gas is frequently stored in underground... 

For clutter suppression, the test statistic used by the noncoherent detector has been proposed as an interesting output signal [1], This was motivated by the fact that, provided that transient and noise models are valid, the test statistic reflects the likelihood that a transient is present. 

A new one-dimensional mierowave imaging approaeh based on suecessive reeonstruetion of dielectrie interfaees is described. The reconstruction is obtained using the complex reflection coefficient data collected over some standard waveguide band. The problem is considered in terms of the optical path length to ensure better convergence of the iterative procedure. Then, the reverse coordinate transformation to the final profile is applied. The method is valid for highly contrasted discontinuous profiles and shows low sensitivity to the practical measurement error. Some numerical examples are presented. 

A novel optimization approach based on the Newton-Kantorovich iterative scheme applied to the Riccati equation describing the reflection from the inhomogeneous half-space was proposed recently [7]. The method works well with complicated highly contrasted dielectric profiles and retains stability with respect to the noise in the input data. However, this algorithm like others needs the measurement data to be given in a broad frequency band. In this work, the method is improved to be valid for the input data obtained in an essentially restricted frequency band, i.e. when both low and high frequency data are not available. This... 

Simulations of that kind result in a wide variety of A-scans and wavefront snapshots. The first screening of this material reveals, that the simulations in which the transducer is coupling partly to the V-butt weld and partly to the steel exhibit quite a number of pulses in the A-scans because the coupling at the interface of the weld results — due to the anisotropic behavior of the weld — in a complicated splitting of the transmitted wavefront. The different parts of the splitted wavefront are reflected and diffracted by the backwall, the interface, and — if present — by the notch and, therefore, many small signals are received by the transducer, which can only be separated and interpreted with great difficultie.s. 

Only the simulations in which the transducer is coupling either to the V-butt weld or to the surrounding steel can be analyzed in a simple and intuitive way, which means that the different pulses in the A-scan signals can be related uniquely to the reflection or diffraction of the wavefront at the weld, the backwall, and/or the notch. 

Second corner reflection The first corner reflection appears as usual when the transducer is coupled to the probe at a certain distance from the V-butt weld. The second corner reflection appears if the transducer is positioned well above the V-hutt weld. If the weld is made of isotropic material the wavefront will miss (pass) the notch without causing any reflection or diffraction (see Fig. 3(a)) for this particular transducer position. In the anisotropic case, the direction of the phase velocity vector will differ from the 45° direction in the isotropic case. Moreover, the direction of the group velocity vector will no longer be the same as the direction of the phase velocity vector (see Fig. 3(b), 3(c)). This can be explained by comparing the corresponding slowness and group velocity diagrams. 

Notch tip With perpendicular grain orientation no notch tips are detected. The snapshots (see Fig. 7 second and third snapshot from top on the right) show that in the direction to the receiver there is a gap in the reflected / diffracted quasi shear wavefront. In contrast, the notch tips can be detected within the herringbone structure. 

We present a novel method, called VIGRAL, to size and position the reflecting surface of a flaw. The method operates on standard B-scan recorded with traditional transducers, to extract Time-of-Flight (ToF) information which is then back-projected to reconstruct the reflecting surface of the flaw and characterize its radiation pattern. The VIGRAL method locates and sizes flaws to within k/2, and differentiates between flat and volumetric defects. 

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