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  • 1
    Electronic Resource
    Electronic Resource
    Compact high repetition rate magnetically switched transverse, electric, atmospheric CO2 laser (1990)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 61 (1990), S. 1821-1824 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A corona preionized compact transverse, electric, atmospheric CO2 laser providing an average optical output of 18 W from a 4.6-cm3 discharge volume is reported. The laser was driven at pulse rates up to 1 kHz by an all solid-state exciter circuit which has produced〉109 pulses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1141100
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  • 2
    Electronic Resource
    Electronic Resource
    Computer simulation of an electrostatic spherical analyzer used as an energy spectrograph (1985)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 56 (1985), S. 1320-1328 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Exit positions and velocities of charged particles passing through an electrostatic spherical analyzer were generated by a computer program which utilizes transformations to the trajectory plane of the particle to obtain an exact solution in the central force field of the analyzer. Entrance and exit planes were treated as a potential jump to zero potential, thus simulating grounded wire meshes at the entrance and exit. It was found that particle input energies could be determined as a function of exit position. A wide variety of designs were tried, varying plate radii, plate voltages, and incoming collimation of the particles. A power-law relationship between exit radius and input energy was found for designs in which the mean radial position between the plates corresponded to zero potential. However, the total input energy spread ΔE of the particles passed by an analyzer could never be made to approach twice the mean input energy E of the particles passed. Since a parabolic analyzer can be made to have a ΔE/E=1.92, we conclude that the parabolic analyzer makes a better spectrograph.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1137998
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  • 3
    Electronic Resource
    Electronic Resource
    Space plasma measurements with ion instruments (1989)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 60 (1989), S. 3750-3761 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: In this article we examine the factors which affect the determination of the plasma bulk parameters in space, with particular emphasis on the density determination. We make this assessment with reference to a particular instrument, the AMPTE-UKS ion instrument, in order to be specific, but the issues raised here are likely to be encountered in the use of any space plasma instrument containing electrostatic energy analyzers or microchannel plate detectors. We have established a mathematical formalism for determining these parameters by relating the measured counts to the distribution function in terms of the geometric factor. The geometric factor is determined in the calibration of the instrument which is described in some detail. Among the factors we have considered are our calibration techniques, MCP efficiency, detector energy, and angular resolution, as well as the approximations used in our mathematical formalism. To establish confidence in our determination, we used a computer simulation to look for systematic errors in the particular characteristics of the analyzer and to verify the method of extraction of plasma parameters. We can conclude that the detector resolution is adequate for determining density for both solar wind (〈5% error) and magnetosheath conditions (〈6% error). The detector resolution is also adequate for measuring velocity, 〈1% error for the solar wind and 〈3% error in the magnetosheath. The detector resolution is not adequate for determining temperature in the solar wind ∼50%; however, in the magnetosheath where the thermal spread is at least as large as the acceptance angles, the resolution is adequate (〈6%). In addition, we tested the influence of the geometric factor on the output bulk parameters by varying the input velocity direction over the entire polar range. The systematic error in the output parameters was less than 5% in all cases.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1141075
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  • 4
    Electronic Resource
    Electronic Resource
    A western Scottish population of the leopard-spotted goby, Thorogobius ephippiatus (Lowe) (Teleostei: Gobioidea) (1973)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 5 (1973), S. 0 
    Details
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: A population of the sublittoral leopard-spotted goby, Thorogobius ephippiatus (Lowe, 1839), is recorded from Upper Loch Torridon, Scotland, and the more northerly occurrence of this Mediterranean-Atlantic species along western Scottish coasts confirmed. Modified methods of capture are described. Distinctive systematic features of this population, which tends to have low sensory papilla and pectoral ray values, are examined with reference to other T. ephippiatus and the related T. macrolepis (Kolombatovic, 1891). The time of onset and reasons for this local differentiation are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1095-8649.1973.tb04452.x
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  • 5
    Electronic Resource
    Electronic Resource
    Measurements of aerobic metabolism of a school of horse mackerel at different swimming speeds (1996)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 49 (1996), S. 0 
    Details
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Oxygen consumption rates were measured in a school of 56 horse mackerel Trachurus trachurus while at rest and while swimming at steady sustained speeds. Resting values of 38.76 and 42.10mg O2 kg−1 h−1 were measured in a sealed cylindrical tank (535 l) while observing that the fish school remained neutrally buoyant and inactive with only gentle pectoral fin movements and no swimming motion. The same school was trained to swim with projected light patterns within a 10-m diameter annular doughnut respirometer. The oxygen consumption increased from the resting level through 51 mg O2 kg−1 h−1 at the slowest swimming speeds of 0.29 m s−1 (0.95 L s−1) to around 259 mg O2 kg−1 h−1 at the higher measured swimming speed of 0.87 m s−1 (2.82 L s−1). The data fitted a curve where oxygen consumption rose in proportion to velocity to the power of 2.56 with the intercept at the resting level. The maximum sustained speed (80 min) of 1.12 m s−1 (3.63 Ls−1) was not achieved within the respirometer but corresponded to an estimated oxygen consumption of 458.33 mg O2 kg−1 h−1 giving a scope for aerobic activity of 419.02 mg O2 kg−1 h−1. At a speed of 0.87 m s−1, there was a lower bound on the aerobic efficiency of at least 38% and at 1.12 m s−1, the highest aerobic speed, of 40%. Sustained speeds swum in a curved path as here should be increased by 5% for a straight path giving a maximum sustained 80 min speed of 1.18 m s−1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1095-8649.1996.tb00084.x
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  • 6
    Electronic Resource
    Electronic Resource
    A comparison of the movements of two species of gadoid in the vicinity of an underwater reef (1994)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 45 (1994), S. 0 
    Details
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Two saithe (35 and 38 cm) and two pollack (43 and 44 cm) were tracked simultaneously for 170 h. During the day, saithe generally patrolled over the whole of an underwater reef as part of a school, making occasional excursions off the reef to another smaller reef 250m distant. At night, saithe movements were largely limited to the reef. Pollack covered less than 50% of the reef during the study period, moving only small distances off the reef. Pollack swam more slowly than saithe during the day, but at the same speed at night.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1095-8649.1994.tb00946.x
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  • 7
    Electronic Resource
    Electronic Resource
    Spawning behaviour and diel periodicity of egg production in captive Atlantic mackerel, Scomber scombrus L. (1992)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 40 (1992), S. 0 
    Details
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Spawning was observed in groups of captive Atlantic mackerel and occurred when a few fish swam away from the main school during a brief burst of high speed swimming. Counts of eggs from aquarium and field studies show that, in contrast to most pelagic fish species, spawning by Atlantic mackerel can occur at any time ofday or night and is not group-synchronized. Implications of the observed die1 periodicity of egg production to stock size estimation by the Daily Egg Production Method are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1095-8649.1992.tb02639.x
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  • 8
    Electronic Resource
    Electronic Resource
    Observations on the retention of intragastric transmitters, and their effects on food consumption, in cod, Gadm morhua L. (1990)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 37 (1990), S. 0 
    Details
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1095-8649.1990.tb05898.x
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  • 9
    Electronic Resource
    Electronic Resource
    The influence of ration size and feeding frequency on ammonia excretion by juvenile Atlantic cod, Gadus morhua L. (1987)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 31 (1987), S. 0 
    Details
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Small groups of juvenile Atlantic cod, Gadus morhua L., were kept at 14°C in through-flow tanks and were fed known quantities of a compounded diet of natural food. The cod were fed single and multiple meals with ration size in the range 0.5 to 4.1% of total wet fish body weight. Ammonia production in each feeding experiment was monitored continuously.For single-meal experiments, significant relationships were derived between ration size and (a) total ammonia excreted, (b) total exogenous ammonia excreted above endogenous excretion levels, (c) duration of the elevated phase of ammonia excretion, (d) maximum rate of ammonia excretion, and (e) time delay after feeding to reach maximum rate of ammonia excretion. Relationships between nitrogen loss as ammonia and nitrogen intake were examined and estimates of endogenous excretion rate and maintenance ration made.Repetitive feeding resulted in cyclical variation in ammonia excretion. At the lowest ration size, ammonia excretion rates had nearly returned to the pre-feeding level within 24 h. At higher feeding levels, the effect of each successive meal tended to be cumulative, resulting in increasingly higher ammonia excretion rates which only stabilized towards the end of the experiments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1095-8649.1987.tb05257.x
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  • 10
    Electronic Resource
    Electronic Resource
    The detection of dissolved amino acids by the Atlantic cod, Gadus morhua L. (1980)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 17 (1980), S. 0 
    Details
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: A classical conditioning technique was employed with cod, Gadus morhua L., to determine thresholds for the detection of the L-forms of some α amino acids which are thought to be attractants or feeding stimulants for fish. The amino acids investigated, in order of effectiveness, were tyrosine, cysteine, phenylalanine, glycine and methionine with mean threshold response levels ranging from 2·5 × 10-8M to 7·4 × 10-8M. Histidine and lysine resulted in similar thresholds with a mean value of approximately 3 ± 10-7M while taurine and leucine were least effective with mean threshold levels of 2·1 × 10-6M and 2·1 × 10-5M respectively. Comparison is made with electrophysiological and behavioural response data from other species. The effect of raising the background level of glycine on the threshold to glycine for cod is described. The results are discussed with reference to data on levels of dissolved free amino acids in shallow sea waters which may have a bearing on determining chemosensory threshold levels. To detect a specific amino acid against a background level of the same substance the difference in level for detection is proportionally greater for higher background concentrations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1095-8649.1980.tb02755.x
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