Problems of metrologic assurance with wave recording apparatus

1990 ◽  
Vol 33 (11) ◽  
pp. 1113-1117
Author(s):  
A. P. Aleksandrov ◽  
�. S. Vaindruk ◽  
G. Yu. Narodnitskii
Keyword(s):  
Recording Apparatus ◽  
Wave Recording

scholarly journals THE PARASITE PHENOMENON IN A TCAVE CANAL

2011 ◽  
Vol 1 (5) ◽  
pp. 6
Author(s):  
J. Kravtchenko ◽  
L. Santon
Keyword(s):  
Longitudinal Axis ◽  
Recording Apparatus ◽  
The Subject ◽  
Wave Profiles ◽  
Wave Filters ◽  
Wave Recording

A detailed study of wave profiles undertaken by our laboratory and making use of a wave recording apparatus, which is the subject of another paper, has drawn our attention to a parasite phenomenon. In certain conditions this phenomenon has a period twice that of the principal movement. The phenomenon appears only over a certain range of periods and has been shown to be the result of a transversal clapotis. The appearance of a transversal clapotis in wave canals is not rare and in practice it is eliminated by placing vertical guides parallel to the longitudinal axis of the canal. We have succeeded in eliminating the transversal clapotis reasonably well, by the use of wave filters. But a progressive phenomenon, with the period of the clapotis, has remained and it has been possible to analyse it.

scholarly journals High spatial resolution photo mosaicking for the monitoring of coralligenous reefs

Coral Reefs ◽  
2021 ◽  
Author(s):  
E. Casoli ◽  
D. Ventura ◽  
G. Mancini ◽  
D. S. Pace ◽  
A. Belluscio ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Low Cost ◽  
Pixel Resolution ◽  
Recording Apparatus ◽  
Assemblage Composition ◽  
Very High Spatial Resolution ◽  
Vertical Walls ◽  
Non Destructive ◽  
Very High

AbstractCoralligenous reefs are characterized by large bathymetric and spatial distribution, as well as heterogeneity; in shallow environments, they develop mainly on vertical and sub-vertical rocky walls. Mainly diver-based techniques are carried out to gain detailed information on such habitats. Here, we propose a non-destructive and multi-purpose photo mosaicking method to study and monitor coralligenous reefs developing on vertical walls. High-pixel resolution images using three different commercial cameras were acquired on a 10 m2 reef, to compare the effectiveness of photomosaic method to the traditional photoquadrats technique in quantifying the coralligenous assemblage. Results showed very high spatial resolution and accuracy among the photomosaic acquired with different cameras and no significant differences with photoquadrats in assessing the assemblage composition. Despite the large difference in costs of each recording apparatus, little differences emerged from the assemblage characterization: through the analysis of the three photomosaics twelve taxa/morphological categories covered 97–99% of the sampled surface. Photo mosaicking represents a low-cost method that minimizes the time spent underwater by divers and capable of providing new opportunities for further studies on shallow coralligenous reefs.

scholarly journals Coincidence counter measurements of cosmic rays in an aeroplane

1936 ◽  
Vol 156 (889) ◽  
pp. 570-577 ◽  
Keyword(s):  
Cosmic Rays ◽  
High Altitude ◽  
Cosmic Ray ◽  
Independent Sets ◽  
Vertical Line ◽  
Coincidence Counting ◽  
Detailed Design ◽  
Recording Apparatus ◽  
Coincidence Counter ◽  
Balloon Experiments

Cosmic ray measurements on mountains are limited in general to altitudes below about 4000 meters. Above this height Regener has made successful use of small balloons carrying self-recording apparatus, and occasional flights have been made with manned balloons by Piccard, Cosyns, and by American workers. Balloon experiments are, however, hardly practicable in this country, so we decided to investigate cosmic rays, and in particular the production of showers, using an aeroplane. Facilities for flying to a height of about 10 km. Were generously provided by the Air Ministry. Apparatus Two independent sets of three tube counters were used in conjunction with the usual coincidence counting circuits. The counters could be arranged in a vertical line to record vertical penetrating particles, or in a triangle to record showers. The triple coincidences were recorded by telephone counters which were photographed at intervals together with a clock and aneroid barometer. The detailed design of the apparatus required some consideration since the aeroplane available (the Vickers Vespa machine used for high altitude experiments at the Royal Aircraft Establishment) had an open observer’s cockpit in which the counting set had to be installed.

scholarly journals Responses of hair cells to statocyst rotation.

1975 ◽  
Vol 66 (4) ◽  
pp. 507-530 ◽  
Author(s):  
D L Alkon
Keyword(s):  
Hair Cell ◽  
Centrifugal Force ◽  
Hair Cells ◽  
New Technique ◽  
Force Vector ◽  
Generator Potential ◽  
Recording Apparatus ◽  
Intracellular Potentials ◽  
A New Technique

A new technique is described for stimulating hair cells of the Hermissenda statocyst. The preparation and recording apparatus can be rotated at up to 78 rpm while recording intracellular potentials. Hair cells in front of the centrifugal force vector depolarize in response to rotation. Hair cells in back of the centrifugal force vector hypoerpolarize in response to rotation. Mechanisms by which the hair cell generator potential might arise are examined.

scholarly journals The nature of large cosmic-ray bursts

1936 ◽  
Vol 154 (881) ◽  
pp. 223-245 ◽  
Keyword(s):  
Cosmic Rays ◽  
Ionization Chamber ◽  
Cosmic Ray ◽  
Conclusive Evidence ◽  
Recording Apparatus ◽  
Ionization Current ◽  
Continuous Record ◽  
Normal Fluctuations

A continuous record of the ionization current produced by cosmic rays in an ionization chamber shows, if the recording apparatus is sufficiently sensitive, occasional relatively large momentary currents superposed on the normal fluctuations. These large momentary currents are generally called “bursts”. They were first discovered by Hoffmann. It has often been assumed that the bursts are of the same nature as the showers which are observed either in the Wilson chamber or by means of three or more coincidence counters; but so far no conclusive evidence, particularly for the larger bursts, has been reported in support of this assumption.

Hippocampal Place-Cell Firing During Movement in Three-Dimensional Space

2001 ◽  
Vol 85 (1) ◽  
pp. 105-116 ◽  
Author(s):  
James J. Knierim ◽  
Bruce L. McNaughton
Keyword(s):  
Hippocampal Neurons ◽  
Horizontal Plane ◽  
Three Dimensional ◽  
Place Cell ◽  
Place Cells ◽  
Limbic Cortex ◽  
Head Direction ◽  
Head Direction Cells ◽  
Recording Apparatus ◽  
Place Fields

“Place” cells of the rat hippocampus are coupled to “head direction” cells of the thalamus and limbic cortex. Head direction cells are sensitive to head direction in the horizontal plane only, which leads to the question of whether place cells similarly encode locations in the horizontal plane only, ignoring the z axis, or whether they encode locations in three dimensions. This question was addressed by recording from ensembles of CA1 pyramidal cells while rats traversed a rectangular track that could be tilted and rotated to different three-dimensional orientations. Cells were analyzed to determine whether their firing was bound to the external, three-dimensional cues of the environment, to the two-dimensional rectangular surface, or to some combination of these cues. Tilting the track 45° generally provoked a partial remapping of the rectangular surface in that some cells maintained their place fields, whereas other cells either gained new place fields, lost existing fields, or changed their firing locations arbitrarily. When the tilted track was rotated relative to the distal landmarks, most place fields remapped, but a number of cells maintained the same place field relative to the x-y coordinate frame of the laboratory, ignoring the z axis. No more cells were bound to the local reference frame of the recording apparatus than would be predicted by chance. The partial remapping demonstrated that the place cell system was sensitive to the three-dimensional manipulations of the recording apparatus. Nonetheless the results were not consistent with an explicit three-dimensional tuning of individual hippocampal neurons nor were they consistent with a model in which different sets of cells are tightly coupled to different sets of environmental cues. The results are most consistent with the statement that hippocampal neurons can change their “tuning functions” in arbitrary ways when features of the sensory input or behavioral context are altered. Understanding the rules that govern the remapping phenomenon holds promise for deciphering the neural circuitry underlying hippocampal function.

A recording apparatus for the measurement of longitudinal creep

1963 ◽  
Vol 7 (4) ◽  
pp. 1273-1279 ◽  
Author(s):  
Henry J. Scherr ◽  
William E. Palm
Keyword(s):  
Recording Apparatus

A New Micro-Respirometer with Automatic Setting and Recording Apparatus

1950 ◽  
Vol 27 (3) ◽  
pp. 334-349
Author(s):  
PETER TUFT
Keyword(s):  
Volume Change ◽  
Constant Pressure ◽  
Volume Changes ◽  
Recording Apparatus

A new micro-respirometer is described, capable of measuring rates of volume change from 5 µl./hr. down to 0.01 µl./hr. to the nearest 0.001 µl. It is a constant-pressure nul-reading instrument and the actual volumes of gas absorbed or evolved are obtained from readings of the instrument by a simple multiplication. A device is described which sets the instrument automatically and records the volume changes at regular intervals.

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