231 research outputs found
Instrumental effects on the temperature and density derived from the light ion mass spectrometer
An expression for the flux into a retarding potential analyzer (RPA) is derived which takes into account the instrumental effect of a dependence on energy of the solid angle of the acceptance cone. A second instrumental effect of a limited bandpass is briefly discussed. Using the (LIMS) instrument on SCATHA, it is shown that temperatures and densities derived without considering the effect of the solid angle dependence on energy will be too low, dramatically so for E(t) E(1), where E(1) is the e folding distance of the solid angle dependence and E(t) is the thermal energy of the plasma. For E(t) E(1), there is effectively no impact on the derived temperatures and densities if the solid angle effect is ignored
Beginning an ESL Program: Underlying Issues and Site-Specific Recommendations
This paper examines the issues involved in starting up an English as Second Language program. The range of issues discussed is limited to three major areas: assessment of language needs in a community; curriculum considerations for the target student group; and teacher training. There are two separate parts within the paper: Part I, a consideration of underlying issues involved in beginning an ESL program in general; and Part II, potential plans for program start-up at an actual site--the First Baptist Church of Flushing, New York.
Planning for a new program at the specific site serves to focus the general discussion of issues and functions as a real case in point. The division into two parts allows readers, if they wish, to concentrate only on the general issues in Part I without having those issues obscured by the site-specific details of Part II
A program of data synthesis from the ALSEP/CPLEE ALSEP/SIDE, and Explorer 35 magnetometer to investigate lunar terminator and nightside particle fluxes and surface interactions
Lunar nightside electron fluxes were studied with the aid of the ALSEP/CPLEE and other instruments. The flux events were shown to be due to (a) electrons propagating upstream from the earth's bow shock, (b) electrons thermalized and scattered to the lunar surface by disturbances along the boundary of the lunar solarwind cavity, and (c) solar wind electrons scattered to the lunar surface by lunar limb shocks and/or compressional disturbances. These electrons were identified as a cause of the high night surface negative potentials observed in tha ALSEP/SIDE ion data. A study was also made of the shadowing of magnetotail plasma sheet electrons by interactions between the lunar body and the ambient magnetic field and by interactions between charged particles and lunar remnant magnetic fields. These shadowing effects were shown to modify lunar surface and near-lunar potential distributions
Charged Particle lunar Environment Experiment (CPLEE)
Research development in the Charged Particle Lunar Environment Experiment (CPLEE) is reported. The CPLEE is ion-electron spectrometer placed on the lunar surface for the purpose of measuring charged particle fluxes impacting the moon from a variety of regions and to study the interactions between space plasmas and the lunar surface. The principal accomplishments reported include: (1) furnishing design specifications for construction of the CPLEE instruments; (2) development of an advanced computer-controlled facility for automated instrument calibration; (3) active participation in the deployment and past-deployment operational phases with regard to data verification and operational mode selection; and (4) publication of research papers, including a study of lunar photoelectrons, a study of plasmas resulting from man-made lunar impart events, a study of magnetotail and magnetosheath particle populations, and a study of solar-flare interplanetary particles
Observations of low-energy electrons upstream of the earth's bow shock
Observations of electron fluxes with a lunar-based electron spectrometer when the moon was upstream of the earth have shown that a subset of observed fluxes are strongly controlled by the interplanetary magnetic field direction. The fluxes occur only when the IMF lines connect back to the earth's bow shock. Observed densities and temperatures were in the ranges 2-4 x 0,001/cu cm and 1.7-2.8 x 1,000,000 K. It is shown that these electrons can account for increases in effective solar wind electron temperatures on bow-shock connected field lines which have been observed previously by other investigators. It is further shown that if a model of the bow shock with an electrostatic potential barrier is assumed, the potential can be estimated to be 500 volts
Calibration of the ISEE plasma composition experiment
The Plasma Composition experiment on the ISEE-1 satellite was designed to measure ions from 1 to 16 amu, at energies from near zero to 16 keV. The two nearly identical flight instruments were calibrated by means of preflight laboratory tests and in-flight data comparisons. This document presents most of the details of those efforts, with special emphasis on the low energy (0 to 100 eV) portion of the instrument response. The analysis of the instrument includes a ray-tracing calculation, which follows an ensemble of test particles through the detector
Biodiversity in drinking water distribution systems:a brief review
In drinking water distribution systems, three groups of living organisms are usually found in the biofilm and circulating water: heterotrophic bacteria, free-living protozoa, and macro-invertebrates. Indirect evidence suggests that protozoa grazing in distribution systems can partially eliminate biomass production and accidental microbiological pollution. This paper examines the biodiversit in drinking water distribution systems
The swept angle retarding mass spectrometer: Initial results from the Michigan auroral probe sounding rocket
Data from a sounding rocket flight of the swept angle retarding ion mass spectrometer (SARIMS) are presented to demonstrate the capability of the instrument to make measurements of thermal ions which are differential in angle, energy, and mass. The SARIMS was flown on the Michigan auroral probe over regions characterized first by discrete auroral arcs and later by diffuse precipitation. The instrument measured the temperature, densities, and flow velocities of the ions NO(+) and O(+). Measured NO(+) densities ranged from 10 to the 5th power up to 3 x 10 to the 5th power ions/cu cm, while the measured O(+) densities were a factor of 5-10 less. Ion temperatures ranged from 0.15 up to 0.33 eV. Eastward ion flows approximately 0.5 km/sec were measured near the arcs, and the observed flow magnitude decreased markedly inside the arcs
Instrument manual for the retarding ion mass spectrometer on Dynamics Explorer-1
The retarding ion mass spectrometer (RIMS) for Dynamics Explorer-1 is an instrument designed to measure the details of the thermal plasma distribution. It combines the ion temperature determining capability of the retarding potential analyzer with the compositional capabilities of the mass spectrometer and adds multiple sensor heads to sample all directions relative to the spacecraft ram direction. This manual provides a functional description of the RIMS, the instrument calibration, and a description of the commands which can be stored in the instrument logic to control its operation
A survey of assimilable organic carbon, biodegradable organic carbon and coliform growth response in US drinking waters
Les objectifs principaux de cette étude étaient :1) De documenter, par une étude de large envergure, les concentrations en COA de l'eau potable, et des usines de traitement.2) De comparer l'indice de croissance des coliformes (ICC) aux concentrations en COA.3) De comparer les concentrations en CODE et celles de COA.Le COA de l'eau a été mesuré avec un mélange de cultures Pseudomonas fluorescens de souche P17 et de Spirillumsp. de souche NOX. La plupart des échantillons d'eaux ont été transferrés dans des ampoules de 40 ml, stérilisés puis inoculés avec les bactéries Pseudomonas et Spirillum et incubés à 15 °C. Les unités formant colonies représentaient le paramètre de suivi.Le test relatif à l'ICC a été réalisé avec l'eau soumise au test, préalablement stérilisée puis inoculée avec Cloacae enterobacter. Les échantillons ont été incubés à 20 °C pendant 5 jours et la croissance des coliformes mesurée par les unités formant colonies.La mesure de CODB a été exécutée dans des ampoules de 40 ml : l'échantillon à analyser, préalablement filtré sur fibre de verre et pasteurisé, était inoculé avec une microflore indigène de rivière puis incubé pendant 28 jours à l'obscurité à température ambiante.L'étude a porté sur 109 échantillons prélevés en 79 points d'approvisionnement en eau potable répartis sur le territoire des Etats-Unis et du Canada : 26 d'eaux souterraines, et 53 d'eaux de surface.Des flacons de prélèvements pour échantillonner et des instructions pour prélever et pasteuriser les eaux ont été fournis à tous les techniciens.L'eau stérilisée était envoyée à la Stroud Water Research Centre pour les analyses du COA, CODB et COD et au Risk Reduction Laboratory pour l'essai relatif à l'indice de croissance des coliformes. Les densités des bactéries coliformes et des bactéries hétérotrophes sur gélose étaient mesurés par les techniciens eux-mêmes.Les concentrations en COD s'échelonnaient de 203 à 4943 µg/L, celles en COA de 18 à 322 µg/L (représentant ainsi de 2,4 % à 44,0 % du COD).Les valeurs élevées du pH dans 5 échantillons d'eau ont inhibé la croissance des bactéries soumises aux deux essais biologiques (AOC ou BDOC).Les concentrations en CODB se sont échelonnées de 1 à 1521 µg/L (soit 0,4 % à 52,8% du COD).L'essai sur l'indice de croissance des coliformes a montré que 79 % des eaux soumises au test n'ont pas permis la croissance des coliformes alors que 7 % entraînaient une forte croissante (toutes provenant d'eaux de surface) et 14 une croissance modérée.Les services des eaux n'ont mis en évidence aucun coliforme et seulement une faible densité de bactéries hétérotrophes dans les eaux des usines de traitement.La corrélation COA-CODB était significative (P≪0,01) avec un coefficient de corrélation de r = 0,594.Des corrélations significatives COA-COD et CODB-COD ont également été mises en évidence.Par contre, les corrélations ICC-COA ou ICC-CODB n'étaient pas significatives.The primary objectives of this study were : 1) to document concentrations of Assimilable Organic Carbon (AOC) in a survey of a broad range of drinking waters and treatment processes; 2) compare the Colilorm Growth Response (CGR) to AOC concentrations; and 3) compare Biodegradable Dissolved Organic Carbon (BDOC) concentrations to AOC concentrations. AOC was measured with mixed cultures of Pseudomonas fluorescens strain P-17 and Spirillum sp. strain NOX. Test waters were transferred to 40-ml vials, pasteurized, inoculated, and incubated at 15°C. Colony forming units was the test parameter. CGR was performed with pasteurized test water inoculated with Enterobacter cloacae. Samples were incubated at 20°C for 5 days and response determined from colony forming units. The BDOC assay was performed in 40-ml vials, with glass fiber filtered, pasteurized test water, inoculated with the indigenous microflore from a stream, and incubated for 28 days in the dark et room temperature. The survey involved 109 samples from 79 drinking water supplies located throughout the United States and Canada, including 26 groundwater and 53 surface water sources. Utility personnel were supplied with sample bottles and instructions for sampling and pasteurtzing the test waters. Pasteurized water was sent to the Stroud Water Research Center for AOC, BDOC, and DOC analyses, and to the Risk Reduction Engineering Laboratory for the CGR assay. Densities of coliforms and heterotrophic plate count bacteria (HPC) were measured in the test waters by utility personnel. DOC concentrations ranged from 203 to 4943 µg/L. AOC concentrations ranged from 18 to 322 µg/L, or 2.4 % to 44.0 % of the DOC. High pH values in 5 test waters inhibited the growth of both AOC bioassay organisms. BDOC concentrations ranged from 1 to 1521 µg/L, or 0.4% to 52.8 % of DOC. The CGR assay indicated that 79 % of the test waters did not promote coliform growth, 7 % were strongly growth promoting, all from surface water sources, and 14 % were moderately growth promoting. No coliforms and only low densities at HPC organisms were reported by utilities for treatment plant effluents. The correlation of AOC and BDOC was significant (P≪0.01), with a correlation coefficient of r=0.594. Significant correlations were also found for AOC and DOC, and BDOC and DOC. Correlations of CGR and either AOC or BDOC were not statistically significant
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