Evans window

Center of gravity of two subbands divided by Evans window, see ref. 15. 

Figure 5.11 Plot of 87Sr/86Sr vs eNd for some examples of English Medieval cathedral window glass. (Wilson, Pollard and Evans unpublished data key in Table 5.4)...

For measurements at temperatures other than ambient, cells with double walls, which can be thermostatted, are also available commercially. If measurements are required at temperatures between ca. —5°C and room temperature, the sample compartment of the spectrometer can be flushed with dry air or nitrogen to reduce condensation on the cell windows. Below ca. — 5 °C the windows can be covered with a thin polythene film, but measurements below —25 °C are very troublesome. The problems associated with low temperature spectroscopic measurements were solved by enclosing the cell in an air-tight box fitted with glass windows (Dadley and Evans, 1967). The box was so designed that it fitted into the spectrophotometer and the air inside the box was dried with phosphoric oxide which, it is claimed, stopped condensation even at temperatures as low as — 60 °C glass windows could be used because only absorptions above 380 nm were of interest. 

Similar intense bands at approximately the same frequencies are observed when other molecules of comparable proton affinity are adsorbed in HZSM-5 e.g.water [41],dimethylether [38,40,41], acetone and various carboxylic acids [41]. Pelmenschikov et al. [42,43] pointed out that these bands are very similar to the so-called A,B,C triplet of OH bands characteristic of strong molecular hydrogen bonded complexes in liquid or solid phases. The most widely accepted explanation for the A,B,C triplet in hydrogen bonded systems is that due to Claydon and Sheppard [44], who suggested that the A,B,C triplet are in fact pseudobands caused by the superposition onto a very broad single (OH) band of two so-called Evans transmission windows caused by Fermi resonance between the (OH) mode and the first overtones of in-plane ( 2 5(OH) = 2600 cm l) and out of plane ( 2 y(OH) = 1900 cm l) bending... 

Various adaptations that rely on force methods have been commercialised (the so-called Evans-Johnson-Matthey balance) or designed from readily available parts and described in the literature. The Evans method uses NMR and can provide variable temperature data on molecules in solution, but the technique is limited to a window where solvents stay liquid and solutes stay in solution. The one development that has been crucial to the more recent rapid development of this research field is the availability of relatively inexpensive and easy-to-use, variable temperature, variable field instrumentation, specifically the Superconducting Quantum Interference Device (SQUID) magnetometer. With a SQUID, it is possible, even for relatively inexperienced users, to determine the magnetic properties of a sample (typically 10-20 mg) as a function of temperature and applied field (down to 1.8 K and... 

Animals and Study Design. This experimental protocol was approved by the Animd Care and Use Committee of the National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health. Time pregnant, female Long-Evans rats at d 3 of gestation were obtained firom Charles River (Portage, Ml) and maintained in our animal facility under conventional conditions with controlled temperature (23 1°C) and illumination (12 h 0600-1800 h). An n-3 adequate diet (maternal diet) containing 3.1% a-linolenic acid and water was consumed ad libitum (Table 1). Litters to be used in this experiment were selected on the basis of body weight and age so that they were within a 12-h time window. At postnatal d 2, three... 

Windows for Macintosh, PC, and X terminals. VAX, Silicon Graphics, Evans 6c Sutherland, and Sun versions. User-written SYBYL Programming Scripts (SPL) are available via anonymous ftp from extreme.chem.rpi.edu and can be browsed through the NIH Molecular Modeling Home Page at URL http //www.nih.gov/molecular modeling/mmhome.html under the Network-Based Services button. 

According to Colomban et al., within the broad band assigned to the hydrogen-bond mode there are several transmission windows, so-called Evans holes [355, 356], These holes are caused by the coupling of a narrow band with a very broad band. Principally, this is a phenomenon similar to the Fermi resonance. The interaction of two or more modes results in new modes and bands of different energies with corresponding transmission modes in the infrared spectrum and emissions in the Raman spectrum, which actually have been observed by Colomban et al. [350]. As a consequence, ex situ spectra have to be checked for unexpected transmissions. In the spectra recorded in situ and shown in Figure 25, band shifts as compared to band positions found in spectra... 

Macfarlane D.R., Sun J., Forsyth M., Bell J.M., Evans L.A., Skryabin I.L. Polymer electrolytes for electrochromic window applications. Solid State Ion. 1996 86-88 959-964 Maheswari S.P., Habib M.A. Electrochromic aspects of phosphotungstic acid. Sol. Energy Mater. Sol. Cells 1988 18 75-82... 

Some problems in the spectrophotometric analysis of dyes are discussed elsewhere in this paper, including the plating out of Evans blue on absorption cell windows the nonadditivity of the spectra of certain dyes the effect of copper upon a direct yellow... 

As in any time series analysis, appropriate time window lengths, number, and overlapping must be used to resolve the low frequencies of interest while minimizing variance. For very broadband seismometers, it is often of interest to understand the self-noise for periods up to several thousands of seconds, which corresponds to a total window length of at least 8 h divided into overlapping sub-windows, each of about an hour (e.g., Table 1 of Evans et al. 2010). 

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