Radioactive (a, n) neutron sources include Ra-Be, PuF4, and four PuBe13 sources. Comparative neutron emission rates were determined by two separate methods: (1) the manganese sulfate bath with appropriate corrections made for fast neutron escape or capture and for thermal neutron capture by the source; and (2) long counter measurements corrected for energy response and so rce anisotropy. Agreement to within 1 percent was obtained by the two independent methods. A Ra-Be source calibrated against the NBS neutron standard was used as a primary reference Spectral measurements of PuBe13 and PuF4 neutron sources were made with nuclear emulsions. By the use of cylindrical plastic and lead absorbers, an effort was made to moderate the PuBe13 spectrum and thereby obtain additional calibration points for instrument response studies. Spectral changes were initially studied with the doublemoderator technique, followed by later measurements with nuclear emulsions. From flux and spectral measurements of the primary and moderated radioactive sources, the first collision tissue dose was calculated and, in turn, compared to experimental measurements of absorbed dose with proportional counters designed according to the Bragg-Gray principle. (Author).

These essays explore some of the most significant current issues concerning the terrain of the Gothic perspective, offering a variety of possible answers to the crucial question: What is Gothic? The collection begins by addressing general issues about the locations and structure of Gothic; this is followed by various considerations of Gothic as a specific historical phenomenon, linked with specific aspects of British, American, and European society; and, finally, by an exploration of Gothic writing during recent decades.

Both airborne & ground hyperspectral surveys have recently been undertaken as potential exploration methods for a variety of mineral deposit types in glaciated regions. This paper reviews a project that aims to summarize the surficial geology & glacial stratigraphy in the Lac de Gras kimberlite field in order to assess hyperspectral ground surveys as a drift prospecting technique for kimberlite in an area with varied overburden thickness. It describes the area's regional geology & glacial history, the reasons for lack of kimberlite indicator minerals above some kimberlite pipes, and the spectral reflectance response of bedrock exposures, kimberlite, and various till samples collected in the area. Limitations of using spectral reflectance data in drift prospecting are also discussed.

A Nike-Javelin rocket (NJ-74-1) was launched at Poker Flat, Alaska, on 11 Apr 74 at 0801 hours UT during a non-auroral condition. A near-zenith spectral radiance profile was obtained from 54 km to an apogee of 118 km on ascent and from 118 km down to about 85.6 km on descent, using a circular variable filter spectrometer. About 464 spectral scans were obtained during flight, covering the range from 1.7 to 5.4 micrometers at a resolution of about 4 percent. The dominant emission feature was at 4.3 micrometer, which is attributed to the CO2 nu3 fundamental. The upward viewed spectral radiance appeared to range from about 215 MRmicrometer at 54 km to less than the noise equivalent spectral radiance of 3 MR /micrometer at 118 km. In this report are given the first quiet condition (no aurora) rocket data in the auroral zone. (Author).

The NPS Spectroirradiometer (spectral irradiance meter) incorporates a rotating spectral wedge filter and was developed to measure the spatial distribution of downwelling underwater solar irradiance. Spectral irradiance data in the 402 to 577 nm regime was observed to depths of 130 m under both clear and foggy sky conditions. Diffuse attenuation coefficients, k, for downwelling light at selected wavelength/depth combinations were calculated from the observed spectral irradiances. The downwelling spectral irradiance values obtained ranged from 436 microwatts/sq. cm/nm at 494 nm to .00150 microwatts/sq cm/nm at 577 nm and are numerically comparable to data from other studies of coastal waters. The calculated values for five selected wavelengths, namely 418, 453, 487, 522, and 557 nm, ranged from .097/m at 418 nm to .274/m at 557 nm and are representative values. The results of the measurements indicate that the NPS Spectroirradiometer provides a practical method of determining irradiance distributions.

This book provides a didactic overview of techniques for inferring information from soil spectroscopic data, and the codes in the R programming language for performing such analyses. It is intended for students, researchers and practitioners looking to infer soil information from spectroscopic data, focusing mainly on, but not restricted to, the infrared range of the electromagnetic spectrum. Little prior knowledge of the R programming language or digital soil spectra is required. We work through the steps to process spectroscopic data systematically.

Spectral Analysis in Geophysics