4,591 research outputs found
NCAR telemetry and command system
The development of a pulse code modulation data encoder, a computerized ground station, and a PCM command system for obtaining and reproducing data from a balloon-borne experiment is discussed. The components of the system and the manner of operation are described. The capabilities and limitations of the system are analyzed
The Life History of Folsomia Candida (Willem) (Collembola: Isotomidae) Relative to Temperature
The parthenogenetic mode of reproduction in Collembola, although frequently questioned in the past (Schaller, 1953; Mayer, 1957; Falkenhan, 1932), has only recently been recorded and confirmed for several species; Onychiutus parthenogeneticus Choudhuri (Choudhuri, 1958), Folsomia candida (Willem) (Goto, 1960; Marshall and Kevan, 1962; Green, 1964; Husson and Paldvody, 1967), Folsomia cavicola Cassagnau and Delamare (Goto, 1960), Tullbergia krausbaueri (Bomer) (Hale, 1966; Petersen, 1971), and Isotoma notabilis Schaffer (Petersen, 1971).
Sex-ratios in populations of the above cited species are often unknown. Existing data indicate that the composition of a population may vary with the geographical distribution of the species. Populations of Folsomia candida (Willem), known to be bisexual in England (Goto, 1960), have been found so far to consist entirely of females in Canada (Sharma and Kevan, 1963a) and in Michigan (Snider, 1973). Similar to I. notabilis and T. krausbaueri (Petersen, 1971), investigations throughout the year and over larger geographic areas are necessary before northern USA and Canada F. candida may be labeled as obligatory parthenogenetic.
Snider (1973) recorded in detail the life cycle of F. candida at 21°C. The present study provides information on the influence of temperature on the bionomics of the species
Improved silver-zinc battery-terminal seals
Development of battery terminal seal for sealing electrolyte for periods of three to five years is discussed. Operating conditions of battery are defined. Components of electrolyte seal and method of production are reported. Schematic diagrams of device are included
Flexible electrical conductors for high-temperature switchgear
Arch-shaped conductors fabricated from flat strips of beryllium oxide dispersion-strengthened copper alloy serve as flexible electrical connectors capable of operating in 1000 deg F temperature range, under vacuum conditions for periods of 10,000 hours or more without failure
Culture Techniques for Rearing Soil Anthropods
Excerpt: Interest in soil biology has been prompted by recent investigations into the action of insecticides on plants and animals. Observations in the field must be supplemented by laboratory investigations conducted under controlled conditions. Consequently, it becomes necessary to rear and handle soil animals under artificial situations for bio-assay and life cycle studies. When large numbers of individuals are required, special problems in maintenance and manipulation arise. Relatively inexpensive and simple methods for such projects are essential and this paper describes some of those techniques which we have found expedient
An eight-month climatology of marine stratocumulus cloud fraction, albedo, and integrated liquid water
As part of the FIRE/Extended Time Observations (ETO) program, extended time observations were made at San Nicolas Island (SNI) from March to October, 1987. Hourly averages of air temperature, relative humidity, wind speed and direction, solar irradiance, and downward longwave irradiance were recorded. The radiation sensors were standard Eppley pyranometers (shortwave) and pyrgeometers (longwave). The SNI data were processed in several ways to deduce properties of the stratocumulus covered marine boundary layer (MBL). For example, from the temperature and humidity the lifting condensation level, which is an estimate of the height of the cloud bottom, can be computed. A combination of longwave irradiance statistics can be used to estimate fractional cloud cover. An analysis technique used to estimate the integrated cloud liquid water content (W) and the cloud albedo from the measured solar irradiance is also described. In this approach, the cloud transmittance is computed by dividing the irradiance measured at some time by a clear sky value obtained at the same hour on a cloudless day. From the transmittance and the zenith angle, values of cloud albedo and W are computed using the radiative transfer parameterizations of Stephens (1978). These analysis algorithms were evaluated with 17 days of simultaneous and colocated mm-wave (20.6 and 31.65 GHz) radiometer measurements of W and lidar ceilometer measurements of cloud fraction and cloudbase height made during the FIRE IFO. The algorithms are then applied to the entire data set to produce a climatology of these cloud properties for the eight month period
Survey of the Herbarium Resources of Ohio
Author Institution: Department of Natural Areas and Preserves, Ohio Department of Natural Resources, Fountain Square ; Department of Biological Sciences, University of CincinnatiMore than one million specimens of vascular and nonvascular plants are housed in Ohio herbaria. These collections are an invaluable scientific resource. Only 13 Ohio herbaria are listed in the Index Herbariorum. This survey identifies 37 Ohio herbaria and summarizes their holdings. Details given for these herbaria include: names and addresses of curators, hours of access, strengths of the collections, and research activities of the staff
Recent Extreme Ultraviolet Solar Spectra and Spectroheliograms
Extreme ultraviolet solar spectra and spectroheliogram analyse
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