scholarly journals SAND BED-FORM LENGTHS UNDER OSCILLATORY MOTION

1980 ◽  
Vol 1 (17) ◽  
pp. 80 ◽  
Author(s):  
Arthur Brebner
Keyword(s):  
Oscillatory Motion ◽  
Water Tunnel ◽  
Dimensionless Form ◽  
Bed Form ◽  
The Relationship

Tests were carried out in the oscillating water tunnel to determine the bed-form lengths of sand ranging from 0.1 mm to 0.55 mm subjected to oscillatory motion of various orbital diameters ranging from 0.15 m to 1.5 m and of various periods ranging from 3 to 15 s. The relationship for the bed-form length is given in the accompanying graph in dimensionless form.

scholarly journals The influence of cerebellar lesions on the swimming performance of the trout

1992 ◽  
Vol 167 (1) ◽  
pp. 171-178
Author(s):  
B. L. Roberts ◽  
A. van Rossem ◽  
S. de Jager
Keyword(s):  
Swimming Performance ◽  
Beat Frequency ◽  
Water Tunnel ◽  
Histological Investigation ◽  
Post Mortem ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Cerebellar Lesions ◽  
All Speeds ◽  
The Relationship ◽  
Tail Beat

The influence of partial cerebellar ablation on the performance of rainbow trout, Oncorhynchus mykiss, swimming in a water tunnel was studied. Before surgery, all fish maintained a steady position in the water tunnel at all speeds tested. A linear relationship was found between the specific velocity (body length s-1) and the tail-beat frequency. After partial cerebellectomy, the fish swam well in the tunnel at low speeds, retaining the relationship between tail-beat frequency and specific velocity, but they were unable to maintain a steady position at water speeds requiring tail-beat frequencies above 3.5 s-1 and were swept backwards. Two sham-operated fish swam at all water speeds tested. Post mortem histological investigation showed that the lesions were restricted to the cerebellar corpus. We conclude that the cerebellum plays no role in the generation of motor programmes but may be essential for their selection and implementation.

Resin Self-Alignment Processes for Self-Assembly Systems

2005 ◽  
Vol 127 (1) ◽  
pp. 18-24 ◽  
Author(s):  
Jong-Min Kim ◽  
Kiyokazu Yasuda ◽  
Kozo Fujimoto
Keyword(s):  
Surface Tension ◽  
Numerical Analysis ◽  
Self Assembly ◽  
Fundamental Concept ◽  
The Self ◽  
Oscillatory Motion ◽  
Assembly Systems ◽  
The Relationship

We have demonstrated the self-alignment processes using surface tension of the resin material for the self-assembly systems. It has been known that the surface tension of the resin material is too low to achieve the self-alignment capability. This paper presents a fundamental concept and principles of resin self-alignment processes. The numerical analysis is conducted to enhance understandings of resin self-alignment behavior and the relationship between process-related parameters. It was proved that resin self-alignment is different from the oscillatory motion of solder self-alignment and shows overdamped motion by the experiment. We could achieve the precise alignment of less than 0.4 μm.

scholarly journals EXPERIMENTS ON BED FORM GENERATION BY WAVE ACTION

1972 ◽  
Vol 1 (13) ◽  
pp. 57 ◽  
Author(s):  
G.R. Mogridge ◽  
J.W. Kamphuis
Keyword(s):  
Specific Gravity ◽  
Wave Action ◽  
Water Tunnel ◽  
Oscillatory Flows ◽  
Wave Flume ◽  
Form Generation ◽  
Sediment Bed ◽  
Wide Range ◽  
Bed Forms ◽  
Bed Form

Experiments to determine the length, height and steepness of bed forms generated by wave action have been conducted in a laboratory wave flume and an oscillating water tunnel. The effects of a wide range of oscillatory flows were examined on polystyrene (specific gravity 1.05, diameter 1.54 mms), bakelite (specific gravity 1.60, diameter 0.52 mms), bakelite (specific gravity 1.51, diameter 0.67 mms) and sand (specific gravity 2.68, diameter 0.36 mms). From the results of the experiments design curves were plotted which make it possible to predict the length and height of bed form that will develop on any specified sediment bed for given conditions of fluid oscillation.

scholarly journals THE THRESHOLD OP MOVEMENT OP COARSE MATERIAL IN OSCILLATORY PLOW

1968 ◽  
Vol 1 (11) ◽  
pp. 30 ◽  
Author(s):  
P.J. Rance ◽  
N.F. Warren
Keyword(s):  
Wave Action ◽  
Oscillatory Motion ◽  
Experimental Results ◽  
Basic Material ◽  
Water Tunnel ◽  
Period Range ◽  
Water Motion ◽  
Coarse Material ◽  
Sea Bed

Experimental results are presented from which it is now possible to predict the threshold of movement of shingle. The experiments were conducted in an Oscillating Water Tunnel, (Ref. 1), on the threshold of movement of shingle size material. The Tunnel simulates the oscillatory water motion at the sea bed due to wave action with a semi-orbit range of 0-4.5 metres and a period range of 5-15 seconds. Additionally, a unidirectional current of up to 0.6 m/sec can also be superposed upon the oscillatory motion. Although limestone chips of between 0.32 cm and 2.5 cm diameters were the basic material tested, other materials such as coal and sand were examined in order to observe the effects of the various parameters over a wider range.

The Nonlinear Analysis of Sensitivity of the Plastic Zone of Surrounding Rock in Underground Caverns

2014 ◽  
Vol 926-930 ◽  
pp. 687-692 ◽  
Author(s):  
Zhi Fang Tian ◽  
Zhi Min Su ◽  
Nian Hong Jiang ◽  
Xue Lu ◽  
Jian Bing Zhu
Keyword(s):  
Analytical Solution ◽  
Plastic Zone ◽  
Friction Angle ◽  
Calculation Model ◽  
Surrounding Rock ◽  
Water Tunnel ◽  
Circular Tunnel ◽  
Finite Element Software ◽  
Underground Caverns ◽  
The Relationship

As the depth and the length of the various underground cavern is increasing, the stability analysis of surrounding rock is very important. This paper first gives the analytical solution equation of the circular tunnel. About the city-gate water tunnel with no analytical solution, it can be solved by numerical method, which is based on the large finite element software ANSYS. The form of a calculation model for conveyance city-gate water tunnel was established. With the D - P criterion, it is nonlinear calculated for the computation of water conveyance tunnel. Then it is obtained that the stress characteristic and development of plastic zone characteristics of the surrounding rock of city-gate tunnel. It also gives the relationship between the development of plastic zone, plastic strain and coefficient of horizontal pressure, the internal friction angle. The last, it is analyzed the relationship between the different parameters and the plastic zone development of different parts of tunnel cavern. This result can provide technical reference for design and the tunnel construction.

scholarly journals Forms of Subglacial Erosion on Palaeozoic Sedimentary Rocks (Abstract only)

1981 ◽  
Vol 2 ◽  
pp. 68-68 ◽  
Author(s):  
R.J. Rogerson ◽  
R. Kodybka
Keyword(s):  
Mechanical Strength ◽  
Rocky Mountains ◽  
Sedimentary Rocks ◽  
Roughness Parameter ◽  
Type Analysis ◽  
3 Dimensional ◽  
Quartz Veins ◽  
Bed Forms ◽  
Bed Form ◽  
The Relationship

The relationship between bedrock erodibility and the characteristic bed form and roughness produced by subglacial abrasion is largely unknown. Less resistant bedrocks may be abraded down to a surface of low obstacle size and low roughness parameter. However, Hallet (1979) notes that bedforms are probably dampened at widely varying rates, and that certain bedforms may actually be amplified through time by rapid trough abrasion. The object of this paper is to examine the relationship between the mechanical strength of several bedrock types and the magnitude of subglacially streamlined bed forms found on them.Cambrian limestones, mudstones, dolomites, and chert, some with abundant quartz veins, are the bedrock types examined. They lie as a series of steeply-dipping beds up to 100 m thick with their strike across the floor of the Yoho valley, in the Rocky Mountains of British Columbia. They were covered by the ice of Yoho Glacier 30 years ago, and are now less than 0.5 km below the present ice terminus. The sites examined lie within an area less than 0.25 km2, up-glacier from a major riegel form. The Yoho River nearby flows in a deep gorge and has not affected this section of the former glacial valley floor.The bedrocks were analysed and tested in the laboratory for mechanical strength and resistance to abrasion.During summer 1979, streamlined bedforms and surface roughness were surveyed along the former glacier flowline, evidenced by striations, and plane table maps were completed across several beds. Small 1 m2 plots were surveyed in detail on each bedrock type. Analysis of surface forms has included 3-dimensional SYMVU plots. Preliminary indications are that the micro-roughness shows greater variability between bedrock types than do large wavelengths of relief. However, resistant bedrocks are areas of prominent positive relief while others are generally low-lying. Analysis of the results continues.

The Use of a New Tilting Tunnel Respirometer to Investigate Some Aspects of Metabolism and Swimming Activity of the Plaice (Pleuronectes Platessa L.)

1980 ◽  
Vol 85 (1) ◽  
pp. 295-309
Author(s):  
I. G. PRIEDE ◽  
F.G. T. HOLLIDAY
Keyword(s):  
Oxygen Consumption ◽  
Metabolic Rate ◽  
Swimming Speed ◽  
Laboratory Experiments ◽  
Resting Metabolic Rate ◽  
Water Tunnel ◽  
Lift Off ◽  
The Cost ◽  
The Relationship ◽  
Negatively Buoyant

1. Plaice and other flatfish can be induced to swim down a slope of about 60° against an upwelling water flow in a water tunnel. 2. A tilting Brett-type tunnel respirometer based on the above principle enabled laboratory experiments on swimming plaice to be carried out. 3. From trials at 5°, 10°, 15 °C, the relationship between specific swimming speed, V (body lengths s−1), oxygen consumption, R (mg−1. kg−1 h−1) and temperature, T is: log10 = 0.3318V + log10 (2.45T+26.52). 4. If the fish is resting (i.e. V = 0), the oxygen consumption is lower than predicted by the above equation. At rest: R = 3.14T+2.66. 5. The cost of swimming in plaice is very similar to that of typical round fish such as haddock but the resting metabolic rate is lower than for haddock. 6. Before swimming, a negatively buoyant fish such as plaice must lift off the bottom. This cost of lift-off or posture effect makes it uneconomical for plaice to swim at speeds below 0.6V.

scholarly journals THE EFFECT OT SELECTED FACTORS ON THE PROCESS OF WEAR UNDER OSCILLATORY MOTION

Tribologia ◽  
2018 ◽  
Vol 279 (3) ◽  
pp. 51-58
Author(s):  
Grzegorz KACZOR
Keyword(s):  
Geometrical Structure ◽  
Friction Pair ◽  
Oscillatory Motion ◽  
Volume Loss ◽  
Friction Couple ◽  
Sliding Motion ◽  
Test Elements ◽  
The Relationship ◽  
Wear Tests ◽  
Conformal Contact

On the surface of the components cooperating under the sliding motion, complex tribological wear processes take place. It leads to the volume loss of components of the friction pair direct metal to metal contact. The amount of this volume depends on the input factors that determine the operation of the friction couple. Therefore, the aim on the presented work was to evaluate the influence of the selected factors on the volume loss on the block and ring under the oscillatory motion. Wear tests were carried out in a non-conformal contact with the use of the T-05 tribotester with the assumed number of operated cycles. As the part of the tests, measurements of the volume loss of the test elements were made. The geometrical structure of the surface of the block and counter block was formed on the basis selected technological process. The relationship between volume and the following factors was obtained: load, frequency of oscillation, and amplitude of oscillation.

Interstellar gas in the central region of the Galaxy

1967 ◽  
Vol 31 ◽  
pp. 239-251 ◽  
Author(s):  
F. J. Kerr
Keyword(s):  
Central Region ◽  
Galactic Plane ◽  
Neutral Hydrogen ◽  
Continuum Emission ◽  
Galactic Centre ◽  
Interstellar Gas ◽  
Hydrogen Recombination ◽  
The Galaxy ◽  
Centre Region ◽  
The Relationship

A review is given of information on the galactic-centre region obtained from recent observations of the 21-cm line from neutral hydrogen, the 18-cm group of OH lines, a hydrogen recombination line at 6 cm wavelength, and the continuum emission from ionized hydrogen.Both inward and outward motions are important in this region, in addition to rotation. Several types of observation indicate the presence of material in features inclined to the galactic plane. The relationship between the H and OH concentrations is not yet clear, but a rough picture of the central region can be proposed.

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