The use of ion exchange resins in the isolation of blodd group A-specific substance from hog gastric mucin

Ion exchange resins (1) have been used in the investigation of A substance hydrolysates (2), but apparently no attempt has been made to determine whether they can be profitably used in the isolation or purification of undegraded A substance [1] from sources such as hog gastric mucin. Studies along these lines are reported in this communication

Vector Reflectometry in a Beam Waveguide

We present a one-port calibration technique for characterization of beam waveguide components with a vector network analyzer. This technique involves using a set of known delays to separate the responses of the instrument and the device under test. We demonstrate this technique by measuring the reflected performance of a millimeter-wave variable-delay polarization modulator

Producing Mega-pixel CMB Maps from Differential Radiometer Data

A major goal of cosmology is to obtain sensitive, high resolution maps of the Cosmic Microwave Background (CMB) anisotropy. Such maps, as would be produced by the recently proposed Microwave Anisotropy Probe (MAP), will contain a wealth of primary information about conditions in the early universe. To mitigate systematic effects when observing the microwave background, it is desirable for the raw data to be collected in differential form: as a set of temperature differences between points in the sky. However, the production of large (mega-pixel) maps from a set of temperature differences is a potentially severe computational challenge. We present a new technique for producing maps from differential radiometer data that has a computational cost that grows in the slowest possible way with increasing angular resolution and number of map pixels. The required central processor (CPU) time is proportional to the number of differential data points and the required random access memory (RAM) is proportional to the number of map pixels. We test our technique, and demonstrate its feasibility, by simulating one year of a space-borne anisotropy mission.Comment: 8 pages Latex with 3 Postscript figures embedded using eps

Changing Farming Systems – Financial Implications for Farming Businesses

Future prosperity of farming businesses depends not only on immediate prospects, but also on the capability to adapt to changing circumstances. In looking to the future, farm managers need to assess where the current farming system is taking them, and whether changing to an alternative farming system might be more profitable. There are various techniques for assessing the profitability of alternative farming systems, but frequently the cost of transition is overlooked. The financial consequences of transition to a new farming system are assessed for two case study farms using a spreadsheet tool (STEP), developed by the authors. The tool assists farm managers in assessing the risk of transition strategies as well as comparing rotations.Farm Management,

A Low Cross-Polarization Smooth-Walled Horn with Improved Bandwidth

Corrugated feed horns offer excellent beam symmetry, main beam efficiency, and cross-polar response over wide bandwidths, but can be challenging to fabricate. An easier-to-manufacture smooth-walled feed is explored that approximates these properties over a finite bandwidth. The design, optimization and measurement of a monotonically-profiled, smooth-walled scalar feedhorn with a diffraction-limited approximately 7 degrees full width at half maximum (FWHM) is presented. The feed was demonstrated to have low cross polarization (<-30 dB) across the frequency range 33-45 GHz (30% fractional bandwidth). A return loss better than -28 dB was measured across the band

The Cosmology Large Angular Scale Surveyor (CLASS): 40 GHz Optical Design

The Cosmology Large Angular Scale Surveyor (CLASS) instrument will measure the polarization of the cosmic microwave background at 40, 90, and 150 GHz from Cerro Toco in the Atacama desert of northern Chile. In this paper, we describe the optical design of the 40 GHz telescope system. The telescope is a diffraction limited catadioptric design consisting of a front-end Variable-delay Polarization Modulator (VPM), two ambient temperature mirrors, two cryogenic dielectric lenses, thermal blocking filters, and an array of 36 smooth-wall scalar feedhorn antennas. The feed horns guide the signal to antenna-coupled transition-edge sensor (TES) bolometers. Polarization diplexing and bandpass definition are handled on the same microchip as the TES. The feed horn beams are truncated with 10 dB edge taper by a 4 K Lyot-stop to limit detector loading from stray light and control the edge illumination of the front-end VPM. The field-of-view is 19 deg x 14 deg with a resolution for each beam on the sky of 1.5 deg. FWHM