10,271 research outputs found
Critical studies in the Epistle to the Hebrews
Thesis (M.A.)--Boston Universit
Angular Power Spectra of the COBE DIRBE Maps
The angular power spectra of the infrared maps obtained by the DIRBE (Diffuse
InfraRed Background Experiment) instrument on the COBE satellite have been
obtained by two methods: the Hauser-Peebles method previously applied to the
DMR maps, and by Fourier transforming portions of the all-sky maps projected
onto a plane. The two methods give consistent results, and the power spectrum
of the high-latitude dust emission is C_\ell \propto \ell^{-3} in the range 2 <
\ell < 300.Comment: ApJ in press. 15 pages with 5 included figure
Analyticity Constraints on Unequal-Mass Regge Formulas
A Regge-pole formula is derived for the elastic scattering of two unequal-mass particles that combines desirable l-plane analytic properties (i.e., a simple pole at l=α in the right-half l plane) and Mandelstam analyticity. It is verified that such a formula possesses the standard asymptotic Regge behavior u^(α(s)) even in regions where the cosine of the scattering angle of the relevant crossed reaction may be bounded. The simultaneous requirements of I-plane and Mandelstam analyticity enforce important constraints, and the consistency of these constraints is studied. These considerations lead to the appearance of a "background" term proportional asymptotically to u^(α(0)-1) which has no analog in the equal-mass problem. We also conclude that a necessary condition for consistency is α(∞)<0
Structure bound water in natural and synthetic quartz, its potential importance in natural rock deformation
Imperial Users onl
Cost of Producing Milk: A Comparison by State
Livestock Production/Industries,
Adjustable mount for electro-optic transducers in an evacuated cryogenic system
The invention is an adjustable mount for positioning an electro-optic transducer in an evacuated cryogenic environment. Electro-optic transducers are used in this manner as high sensitivity detectors of gas emission lines of spectroscopic analysis. The mount is made up of an adjusting mechanism and a transducer mount. The adjusting mechanism provided five degrees of freedom, linear adjustments and angular adjustments. The mount allows the use of an internal lens to focus energy on the transducer element thereby improving the efficiency of the detection device. Further, the transducer mount, although attached to the adjusting mechanism, is isolated thermally such that a cryogenic environment can be maintained at the transducer while the adjusting mechanism remains at room temperature. Radiation shields also are incorporated to further reduce heat flow to the transducer location
Proximal sensing in soil profiles
Objective and quantitative soil information is crucial for pedological investigations and to inform diverse decision making processes. New techniques are required so that soil information can be ascertained in a timely manner to support sampling at finer spatial and temporal resolutions. Currently, no single technique can provide information on all of the properties of interest. This research investigated the conjoint use of visible near-infrared diffuse reflectance spectroscopy (VisNIR) and portable X-ray fluorescence spectroscopy (pXRF) for the in situ investigation of soil properties, profile variability and description. Fifteen soil pits across New South Wales, Australia, were selected for their diverse representation of soil properties. Sampling at these sites involved scanning three vertical with sensor readings taken at 2.5 cm intervals to a depth of 1 m within each transect. Soils were described by traditional pit description techniques and horizon based sampling was conducted to characterise the soil in terms of mineral composition, OC, TC, TN, CEC, EC, pH and PSA. A data fusion approach involving model averaging, and a mass balance was implemented to characterise the mineral composition of soils, including phyllosilicates sesquioxides, carbonate, gypsum, quartz and feldspars. Results were validated against X-ray diffraction analysis. To explore the predictive capability of scans taken in situ, existing spectral libraries were used to calibrate VisNIR and pXRF models and identify the best use of proximal sensor data to maximise soil information gain. As not all properties of interest have detectable spectral activity by either VisNIR or pXRF, a spectral soil inference system (SPEC-SINFERS) to augment the number of predicted properties. This system involved the propagation of sensor and model uncertainties through one hundred independent simulations for each calculation, and allowed the integration of both regression models and machine learning techniques
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