Highly linear, sensitive analog-to-digital converter

Analog-to-digital converter converts 10 volt full scale input signal into 13 bit digital output. Advantages include high sensitivity, linearity, low quantitizing error, high resistance to mechanical shock and vibration loads, and temporary data storage capabilities

A conceptual design study for the secondary mirror drive of the shuttle infrared telescope facility (SIRTF)

Various conceptual designs for the secondary mirror actuator system to be used in the Shuttle Infrared Telescope Facility (SIRTF) were evaluated. In addition, a set of design concepts was developed to assist in the solution of problems crucial for optimum performance of the secondary mirror actuator system. A specific conceptual approach was presented along with a plan for developing that approach and identifying issues of critical importance in the developmental effort

Behavior of soils under impact loading

Experimental soil behavior under impact loadin

Behavior of a sandy clay under vertical impact of geometric shapes

Sandy clay response under vertical impact of cone, plate, and plane geometric shape

Parrondo-like behavior in continuous-time random walks with memory

The Continuous-Time Random Walk (CTRW) formalism can be adapted to encompass stochastic processes with memory. In this article we will show how the random combination of two different unbiased CTRWs can give raise to a process with clear drift, if one of them is a CTRW with memory. If one identifies the other one as noise, the effect can be thought as a kind of stochastic resonance. The ultimate origin of this phenomenon is the same of the Parrondo's paradox in game theoryComment: 8 pages, 3 figures, revtex; enlarged and revised versio

A study of lunar resources - A preliminary report of surface and some other mining systems Summary report, 22 May 1965 - 1 May 1966

Use of extraterrestrial resources in lunar and planetary exploratio

The effect of soil acidity on crop and pasture production

Contents: 1. Summary. 2. Details of research. 2.1 Problem definition glasshouse trial. 2 (a) Vegetative yield affected by topsoil acidity. 2 (b) Root growth in acid subsoil . 2.2 Field Trials. (a) Wheat - Grain yield - Vegetative Growth. (b) Clover. (c) Acidification of soils from the use of nitrogen fertilisers 3. Appendices - trial data. Summary: 1. Problem defining glasshouse trials on soil from 12 sites were conducted in summer/autumn. Results showed that the components of soil acidity affecting wheat growth... 2. The lime and molybdenum requirements of wheat and clover were examined at the sites from which soil came for the glasshouse trials. 3. Calculations of potential acidification rates from the use of nitrogen fertilisers were made- 80GL7, A short summary has been prepared. For those wishing more detail a full report follows the summary. Appendices containing all data from the trials follow the report. Summary: 1. Problem defining glasshouse trials on soil from 12 sites were conducted in summer/autumn… 2. The lime and molybdenum requirements of wheat and clover were examined at the sites from which soil came for the glasshouse trials… 3. Calculations of potential acidification rates from the use of nitrogen fertilisers were made… Details of research: (1)Problem definition - glasshouse trials: (a) Vegetative growth affected by topsoil acidity: 80GL7 Wilroy - 80GE5, Perenjori - 79TS1, Kalannie - 80M04, Kalannie - 80M05, Merredin – (80MI paddock), Bencubbin - 80ME3. Merredin - GL7 (a) (80MI virgin), Yealering – 80N4. Perenjori - 80TS6. Trayning - 80ME4.Gutha - 80GE6. Darkan - 80NA3. Effect of lime and molybdenum on vegetative and grain yield of wheat at eleven sites: 80TS6, 80ME3, 79TS2, 79GE10, 80M30, 80MO4, 80M30, 80MO5, 80GE6, 80GE5, 80ME4, 80NA4. 1. Methods: 1.1 Soil Analysis. 1.2 Nodule rating system. 1.3 Pasture rating (80M29, 30, 31). 2. Glasshouse trials:. 2.1 80GL7 and 7a Soil acidity investigations . 2.2 80GL13 Subsoil acidity and root growth . FIELD TRIALS, PAGE NO. 3.1 80GE5 18 3.2 80GE6 22 3.3 79GE10 27 3.4 80ME3 31 3.5 80ME4 36 3.6 80NA3 41 3.7 80NA4 45 3.8 80M04 48 3.9 80M05 53 3.10 79M027 59 3.11 80TS6 60 3.12 79TS1 65 3.13 79TS2 68 3.14 80M30 70 3.15 80M29 75 3.16 80M31 78 3.17 80Ml 81 3.18 80N3 82 3.19 80WH3 83

Adaptation Reduces Variability of the Neuronal Population Code

Sequences of events in noise-driven excitable systems with slow variables often show serial correlations among their intervals of events. Here, we employ a master equation for general non-renewal processes to calculate the interval and count statistics of superimposed processes governed by a slow adaptation variable. For an ensemble of spike-frequency adapting neurons this results in the regularization of the population activity and an enhanced post-synaptic signal decoding. We confirm our theoretical results in a population of cortical neurons.Comment: 4 pages, 2 figure

Spatial retarding field energy analyzer measurements downstream of a helicon double layer plasma

Spatial ion energy measurements using a retarding field energy analyzer are performed in the exhaust of a 0.30mTorr, 250W helicon double layerplasma to investigate the divergence of the argon ion beam formed by acceleration in the double layer. Various divergence angles are computed by considering the radial distribution of beam density; the average beam ion diverging by 9°. The efficiency at which momentum is imparted parallel to the longitudinal axis of the thruster is calculated to be 98%. The results show that a few centimeters downstream of the source, the beam ions do not follow the magnetic field lines

A Study of Feature Extraction Using Divergence Analysis of Texture Features

An empirical study of texture analysis for feature extraction and classification of high spatial resolution remotely sensed imagery (10 meters) is presented in terms of specific land cover types. The principal method examined is the use of spatial gray tone dependence (SGTD). The SGTD method reduces the gray levels within a moving window into a two-dimensional spatial gray tone dependence matrix which can be interpreted as a probability matrix of gray tone pairs. Haralick et al (1973) used a number of information theory measures to extract texture features from these matrices, including angular second moment (inertia), correlation, entropy, homogeneity, and energy. The derivation of the SGTD matrix is a function of: (1) the number of gray tones in an image; (2) the angle along which the frequency of SGTD is calculated; (3) the size of the moving window; and (4) the distance between gray tone pairs. The first three parameters were varied and tested on a 10 meter resolution panchromatic image of Maryville, Tennessee using the five SGTD measures. A transformed divergence measure was used to determine the statistical separability between four land cover categories forest, new residential, old residential, and industrial for each variation in texture parameters