Vessel navigation risk and stern-swing index in sharp bend channels

Abstract This paper demonstrates that high-gain, high-frequency portable seismographs operated for short intervals can provide unique data on the details of the current tectonic activity in a very small area. Five high-frequency, high-gain seismographs were operated at 25 sites along the coast of northern California during the summer of 1968. Eighty per cent of 160 microearthquakes located in the Cape Mendocino area occurred at depths between 15 and 35 km in a well-defined, horizontal seismic layer. These depths are significantly greater than those reported for other areas along the San Andreas fault system in California. Many of the earthquakes of the Cape Mendocino area occurred in sequences that have approximately the same magnitude versus length of faulting characteristics as other California earthquakes. Consistent first-motion directions are recorded from microearthquakes located within suitably chosen subdivisions of the active area. Composite fault plane solutions indicate that right-lateral movement prevails on strike-slip faults that radiate from Cape Mendocino northwest toward the Gorda basin. This is evidence that the Gorda basin is undergoing internal deformation. Inland, east of Cape Mendocino, a significant component of thrust faulting prevails for all the composite fault plane solutions. Thrusting is predominant in the fault plane solution of the June 26 1968 earthquake located along the Gorda escarpement. In general, the pattern of slip is consistent with a north-south crustal shortening. The Gorda escarpment, the Mattole River Valley, and the 1906 fault break northwest of Shelter Cove define a sharp bend that forms a possible connection between the Mendocino escarpment and the San Andreas fault. The distribution of hypocenters, relative travel times of P waves, and focal mechanisms strongly indicate that the above three features are surface expressions of an important structural boundary. The sharp bend in this boundary, which is concave toward the southwest, would tend to lock the dextral slip along the San Andreas fault and thus cause the regional north-south compression observed at Cape Mendocino. The above conclusions support the hypothesis that dextral strike-slip motion along the San Andreas fault is currently being taken up by slip along the Mendocino escarpment as well as by slip along northwest trending faults in the Gorda basin.

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Low loss sharp bend for silicon nanophotonic slow-light waveguide

2008 5th IEEE International Conference on Group IV Photonics ◽

10.1109/group4.2008.4638180 ◽

2008 ◽

Cited By ~ 1

Author(s):

Huaxiang Yi ◽

Yi Wang ◽

Junbo Feng ◽

Yao Chen ◽

Zhiping Zhou

Keyword(s):

Slow Light ◽

Low Loss ◽

Sharp Bend ◽

Light Waveguide

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On the effect of a sharp bend in a fully developed turbulent pipe-flow

Journal of Fluid Mechanics ◽

10.1017/s0022112068002107 ◽

1968 ◽

Vol 34 (3) ◽

pp. 595-608 ◽

Cited By ~ 62

Author(s):

M. J. Tunstall ◽

J. K. Harvey

Keyword(s):

Secondary Flow ◽

Pipe Flow ◽

Secondary Circulation ◽

Turbulent Pipe Flow ◽

Sharp Bend ◽

Random Frequency ◽

Angle Bend ◽

Circulatory Flow ◽

Flow Through ◽

Upstream Flow

It has been found experimentally that the turbulent pipe flow through a mitred, right-angle bend produces a downstream secondary circulation which does not conform to the twin-circulatory flow usually to be found in pipe bends. The secondary flow is dominated by a single circulation about the axis in either a clockwise or an anticlockwise sense, between which it switches abruptly at a low, random frequency. The phenomenon is explained in terms of the asymmetry of the inner wall separation and the turbulent axial circulation generated in the upstream flow.

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Pyrgotid Flies Assigned to Apyrgota. III. Species of Afropyrgota gen. n. and Tylotrypes (Diptera, Pyrgotidae) / Мухи-пирготиды, отнесённые к Apyrgota. III. Виды Afropyrgota gen. n. и Tylotrypes (Diptera, Pyrgotidae)

Vestnik Zoologii ◽

10.1515/vzoo-2015-0003 ◽

2015 ◽

Vol 49 (1) ◽

pp. 25-40

Author(s):

V. A. Korneyev

Keyword(s):

Type Species ◽

New Genus ◽

Sharp Bend ◽

Large Size

Abstract Afropyrgota gen. n. (type species: Apyrgota marshalli Hendel, 1914) is established to include five species, Afropyrgota copelandi sp. n., Afropyrgota mambilla sp. n., Afropyrgota marshalli (Hendel, 1914) comb. n. (= Apyrgota marshalli Hendel, 1914), Afropyrgota ota sp. n. and Afropyrgota uzungwa sp. n., occurring in the tropical part of Africa. All species are described, illustrated and keyed. Th e new genus is similar to Eupyrgota Coquillett in having large size and wasp-like appearance, wing with spurious vein inserted at deep and sharp bend of R2+3, and femora with two ventral rows of shortened and thickened setae, clearly diff ering by the lack of the finger-like projections on presternum and sclerotized hooks on oviscape. Four species formerly assigned to Apyrgota are shown to belong to Tylotrypes Bezzi: T. breviventris (Shi, 1996), comb. n.; T. fura (Shi, 1996), comb. n.; T. jiangleensis (Shi, 1994), comb. n.; T. longa (Shi, 1996), comb. n.; in addition, 2 species are transferred here from Campylocera Macquart and Adapsilia Waga: T. fuscipes (Wulp, 1885), comb. n. and T. hispida (Kim & Han, 2001), comb. n. A revised diagnosis of the genus Tylotrypes is given

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Experimental investigation on streamlines in a 180º sharp bend

Acta Scientiarum Technology ◽

10.4025/actascitechnol.v39i4.29032 ◽

2017 ◽

Vol 39 (4) ◽

pp. 425 ◽

Cited By ~ 3

Author(s):

Mohammad Vaghefi ◽

Maryam Akbari

Keyword(s):

Experimental Investigation ◽

Sharp Bend

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Effect of Rib Spacing on Heat Transfer in a Two-Pass Rectangular Channel (AR=1:4) With a Sharp Entrance at High Rotation Numbers

Volume 4: Heat Transfer, Parts A and B ◽

10.1115/gt2008-50311 ◽

2008 ◽

Cited By ~ 3

Author(s):

Michael Huh ◽

Yao-Hsien Liu ◽

Je-Chin Han ◽

Sanjay Chopra

Keyword(s):

Heat Transfer ◽

Aspect Ratio ◽

Heat Transfer Enhancement ◽

Rotation Number ◽

Rectangular Channel ◽

Transfer Enhancement ◽

Sharp Bend ◽

Buoyancy Parameter ◽

First Pass ◽

Rib Turbulators

The focus of the current study was to determine the effects of rib spacing on heat transfer in rotating 1:4 AR channels. In the current study, heat transfer experiments were performed in a two-pass, 1:4 aspect ratio channel, with a sharp bend entrance. The channel leading and trailing walls in the first pass and second pass utilized angled rib turbulators (45° to the mainstream flow). The rib height-to-hydraulic diameter ratio (e/Dh) was held constant at 0.078. The channel was oriented 90° to the direction of rotation. Three rib pitch-to-rib height ratios (P/e) were studied: P/e = 2.5, 5, and 10. Each ratio was tested at five Reynolds numbers: 10K, 15K, 20K, 30K and 40K. For each Reynolds number, experiments were conducted at five rotational speeds: 0, 100, 200, 300, and 400 rpm. Results showed that the sharp bend entrance has a significant effect on the first pass heat transfer enhancement. In the second pass, the rib spacing and rotation effect are reduced. The P/e = 10 case had the highest heat transfer enhancement based on total area, whereas the P/e = 2.5 had the highest heat transfer enhancement based on the projected area. The current study has extended the range of the rotation number (Ro) and local buoyancy parameter (Box) for a ribbed 1:4 aspect ratio channel up to 0.65 and 1.5, respectively. Correlations for predicting heat transfer enhancement, due to rotation, in the ribbed (P/e = 2.5, 5, and 10) 1:4 aspect ratio channel, based on the extended range of the rotation number and buoyancy parameter, are presented in the paper.

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