Energy Considerations in the Bay of Fundy System

1958 ◽  
Vol 15 (2) ◽  
pp. 115-134 ◽  
Author(s):  
H. J. McLellan
Keyword(s):  
Mixed State ◽  
Roughness Length ◽  
Tidal Range ◽  
Bay Of Fundy ◽  
The Moon ◽  
Tidal Friction ◽  
Roughness Elements ◽  
Passamaquoddy Bay ◽  
The Mean ◽  
Average Size

Following developments of Taylor, Allard and Redfield, the rates at which energy is dissipated in the Bay of Fundy in various ways are calculated. A total of 30.9 × 106 kw. is transmitted into the bay of which 1.26 × 106 kw. is transmitted into Passamaquoddy Bay. Work is done on the moon at the rate of 2.48 × 106 kw. and 0.03 × 106 kw. is used to maintain the mixed state in the waters of the Bay of Fundy. The remaining 27.1 × 106 kw. must be dissipated by tidal friction. This value is compatible with the usual concepts of turbulent flow over a rough surface if the "roughness length" (Z0) is equal to 0.4 cm. or the average size of the roughness elements (E) is about 11 cm.The effect which the extraction of additional power from the system would have on tidal ranges is evaluated. The range at the head of the Bay of Fundy would decrease at the rate of 0.84 foot (26 cm.) for each million kilowatts. The proposed Passamaquoddy Project would probably increase the mean tidal range at Hopewell Cape by 0.6 foot (18 cm.)

Intertidal zonation and seasonality of the marine hydroid Dynamena pumila (Cnidaria: Hydrozoa)

2002 ◽  
Vol 80 (9) ◽  
pp. 1526-1536
Author(s):  
Lea-Anne Henry
Keyword(s):  
Environmental Conditions ◽  
Temporal Dynamics ◽  
Wave Exposure ◽  
Tidal Range ◽  
Bay Of Fundy ◽  
Rocky Shores ◽  
Four Seasons ◽  
The Mean ◽  
Highly Correlated ◽  
Number Of Branches

The vertical zonation and temporal dynamics of the marine hydroid Dynamena pumila were assessed across a wave-exposure gradient on five rocky shores in the Bay of Fundy, Atlantic Canada. Hydroid abundance and occupancy (i.e., percentage occurrence in a quadrat) were measured in 0.25-m2 quadrats at eight vertical elevations for each site over four consecutive seasons. Hydroid abundance and occupancy were highly correlated (R2 = 0.877). Estimates of hydroid fertility (percentage of sexually reproductive colonies) and size (stem height and number of branches) were obtained in five quadrats at every elevation over the four seasons. Abundance peaked at about 37.5–62.5% of the mean tidal range, with maximum abundance at the site with moderate wave exposure. Abundance peaked during the summer and dropped dramatically over the winter, particularly at the more wave-exposed sites. Winter ice scour and unfavourable environmental conditions reduced hydroid abundance, fertility, and size during the winter. This study demonstrates dramatic shifts in the distribution, fertility, and size of a marine hydroid. The importance of wave action, ice scour, and seasonal changes in environmental conditions is highlighted to emphasize their roles in regulating intertidal hydroid communities on boreal rocky shores.

Herring Migrations in the Passamaquoddy Region

1958 ◽  
Vol 15 (6) ◽  
pp. 1329-1343 ◽  
Author(s):  
R. A. McKenzie ◽  
B. E. Skud
Keyword(s):  
Nova Scotia ◽  
Gulf Of Maine ◽  
Far East ◽  
Bay Of Fundy ◽  
Total Length ◽  
Straight Line ◽  
Passamaquoddy Bay ◽  
Straight Line Distance ◽  
The Mean ◽  
Mean Time

From June 20 to November 21, 1957, 37,495 herring were tagged in the southern part of the Bay of Fundy and Gulf of Maine. These fish were immature and ranged in total length from 14.2 to 18.7 cm. and in age from 1 to 3 years. Recovery of 792 (2.1%) tagged individuals indicated that the herring moved in and out of Passamaquoddy Bay throughout the summer and early autumn. No interchange of herring took place between Passamaquoddy Bay and the coast of Maine or Nova Scotia. Herring moved into Passamaquoddy from as far south as Grand Manan Island and as far east as Point Lepreau. The greatest straight-line distance moved was 55 miles, the mean time before recapture was 12 days, and the longest time 82 days.

Probable Effects of Proposed Passamaquoddy Power Project on Oceanographic Conditions

1961 ◽  
Vol 18 (2) ◽  
pp. 163-201 ◽  
Author(s):  
R. W. Trites
Keyword(s):  
Deep Layer ◽  
High Water ◽  
Tidal Range ◽  
Bay Of Fundy ◽  
Present Value ◽  
Passamaquoddy Bay ◽  
Tidal Stream ◽  
Summer Maximum ◽  
Power Project ◽  
Oceanographic Conditions

The proposed Passamaquoddy power project involves the construction of a series of dams across the mouth of Passamaquoddy and Cobscook Bays. Passamaquoddy Bay, the proposed high pool, will be filled near high water by 90 filling gates, and Cobscook Bay, the proposed low pool, will be emptied near low water by 70 emptying gates. Water will flow continuously from the high pool to the low pool, through a 30-turbine powerhouse. Tidal range will be reduced to approximately 4 and 8 ft in the high and low pools respectively. The effect of this proposed installation on oceanographic conditions in the region has been considered. It is concluded that currents, within the impounded bays and in the area lying inside the Bliss Island–Head Harbour region, will be altered markedly. In the outer Quoddy Region, tidal stream directions will be altered only slightly, while the changes in speed will probably not exceed 20% of their present value. No significant change in residual flow is expected outside the Quoddy Region. Not more than a 1% increase in tidal range is anticipated for the entire Bay of Fundy. Inside the impounded bays, there will be increased stratification. Seasonal variations in temperature of the surface layer will be increased. The summer maximum is expected to reach 20 °C and the winter minimum will be less than 0 °C. Ice cover is expected to occur over part of the impounded waters. Salinities at the surface will be reduced. Only minor changes in temperature and salinity of the deep layer are anticipated. No significant changes are expected in temperature or salinity in the outer Quoddy Region.

scholarly journals Sonic tracking of wild cod, Gadus morhua, in an inshore region of the Bay of Fundy: a contribution to understanding the impact of cod farming for wild cod and endangered salmon populations

2006 ◽  
Vol 63 (7) ◽  
pp. 1364-1371 ◽  
Author(s):  
Paul Brooking ◽  
Gino Doucette ◽  
Steve Tinker ◽  
Frederick G. Whoriskey
Keyword(s):  
Gadus Morhua ◽  
Atlantic Cod ◽  
Late Summer ◽  
Bay Of Fundy ◽  
Release Point ◽  
Passamaquoddy Bay ◽  
The Mean ◽  
Migration Corridor ◽  
Sea Cage ◽  
The Impact

Abstract Sea cage trials of Atlantic cod farming have begun in the Bay of Fundy region. We fitted inshore wild cod (n = 10) captured in the Quoddy region with sonic tags during the late summer of 2004 to provide data on their temporal and spatial residency and habitat usage, with a view to understanding the potential for impact between escaped farmed cod and wild cod and other fish species, particularly Atlantic salmon. Most of the tagged cod remained within a restricted corridor in the inshore zone, occupied deep water (75–130 m) within several kilometres of the release point, and undertook local movements. Three cod undertook more extensive movements; one fish emigrated offshore immediately, and two fish moved as far as 14 km from the release point before returning, 52–54 h later, to the area in which the other cod were located. The mean residence time in the inshore zone was 55 days. In the late autumn, there was a staggered pattern of departure from the coastal zone, although one fish over-wintered in Passamaquoddy Bay. Three of the nine cod that migrated offshore in autumn 2004 returned within a three-week period in May 2005, after a mean absence of 172 days, and reoccupied the inshore region inhabited the previous year. These cod left the region again after a mean residence of 120 days during the spring and summer. The presence of some of the tagged cod in the principal migration corridor for wild salmon smolts during the period of their migration suggests that escapes from cod farms could result in increased predation on salmon smolts from endangered populations.

The motion of a lunar orbiter

1966 ◽  
Vol 25 ◽  
pp. 373
Author(s):  
Y. Kozai
Keyword(s):  
Degrees Of Freedom ◽  
Dimensional Space ◽  
Artificial Satellite ◽  
Equations Of Motion ◽  
Triaxial Ellipsoid ◽  
The Moon ◽  
Secular Motion ◽  
The Earth ◽  
Close Satellite ◽  
The Mean

The motion of an artificial satellite around the Moon is much more complicated than that around the Earth, since the shape of the Moon is a triaxial ellipsoid and the effect of the Earth on the motion is very important even for a very close satellite.The differential equations of motion of the satellite are written in canonical form of three degrees of freedom with time depending Hamiltonian. By eliminating short-periodic terms depending on the mean longitude of the satellite and by assuming that the Earth is moving on the lunar equator, however, the equations are reduced to those of two degrees of freedom with an energy integral.Since the mean motion of the Earth around the Moon is more rapid than the secular motion of the argument of pericentre of the satellite by a factor of one order, the terms depending on the longitude of the Earth can be eliminated, and the degree of freedom is reduced to one.Then the motion can be discussed by drawing equi-energy curves in two-dimensional space. According to these figures satellites with high inclination have large possibilities of falling down to the lunar surface even if the initial eccentricities are very small.The principal properties of the motion are not changed even if plausible values ofJ3andJ4of the Moon are included.This paper has been published in Publ. astr. Soc.Japan15, 301, 1963.

Modelling the Mean Barotropic Circulation in the Bay of Fundy and Gulf of Maine

1983 ◽  
Vol 13 (5) ◽  
pp. 886-904 ◽  
Author(s):  
David A. Greenberg
Keyword(s):  
Gulf Of Maine ◽  
Bay Of Fundy ◽  
The Mean

scholarly journals On tho proportions of the prevailing winds, the mean temperature, and depth of rain in the climate of London, computed through a cycle of Eighteen Years, or periods of the Moon’s declination

1843 ◽  
Vol 4 ◽  
pp. 300-300
Keyword(s):  
The Moon ◽  
Fair Weather ◽  
North West ◽  
West Wind ◽  
North East ◽  
East Wind ◽  
The North ◽  
The Common ◽  
The Mean ◽  
Solar Influence

In this paper the author investigates the periodical variations of the winds, rain and temperature, corresponding to the conditions of the moon’s declination, in a manner similar to that he has already followed in the case of the barometrical variations, on a period of years extending from 1815 to 1832 inclusive. In each case he gives tables of the average quantities for each week, at the middle of which the moon is in the equator, or else has either attained its maximum north or south declination. He thus finds that a north-east wind is most promoted by the constant solar influence which causes it, when the moon is about the equator, going from north to south; that a south-east wind, in like manner, prevails most when the moon is proceeding to acquire a southern declination ; that winds from the south and west blow more when the moon is in her mean degrees of declination, going either way, than with a full north or south declination ; and that a north-west wind, the common summer and fair weather wind of the climate, affects, in like manner, the mean declination, in either direction, in preference to the north or south, and most when the moon is coming north. He finds the average annual depth of rain, falling in the neighbourhood of London, is 25’17 inches.

scholarly journals Surgical and Postoperative Evaluations of Rectal Adenomas Ecised With a Novel Proctoscope.

2020 ◽  
Author(s):  
Roberta Denise Alkmin Lopes Lima ◽  
Rogerio Serafim Parra ◽  
Marley Ribeiro Feitosa ◽  
Omar Féres ◽  
José Joaquim Ribeiro Rocha
Keyword(s):  
Operative Time ◽  
Average Distance ◽  
Economic Feasibility ◽  
Surgeon Experience ◽  
Average Operative Time ◽  
The Mean ◽  
Average Size ◽  
High Level ◽  
Complex Methods

Abstract Purpose Many transanal endoscopic surgeries require a high level of technical expertise and surgeon experience. Considering the economic feasibility of material acquisition and the technical feasibility of training and experience with complex methods, a simpler technique with available resources is relevant for the excision of rectal adenomas. This study presents the surgical and postoperative results achieved with a novel proctoscope using the transanal endoscopic technique to excise rectal adenomas. The results are compared to the results obtained with other currently employed transanal techniques. Methods We retrospectively investigated the medical records of patients who underwent transanal endoscopic operations from April 2000 to June 2018 at two tertiary referral centers for colorectal cancer. Results This study included 99 patients. The mean age was 65.3 ± 13.3 years. The average size of the adenomas was 4.6 ± 2.3 cm, and their average distance to the anal border was 5.6 ± 3.3 cm. The average operative time was 65.3 ± 41.7 min. In 48.5% of the operations, the specimen was fragmented, and in 59.6% of the cases, the microscopic margins were free. The rates of postoperative complications and relapse were 5% and 19%, respectively. The mean follow-up was 80 ± 61.5 months. Conclusions The described proctoscope proved to be a viable technique with results similar to other techniques, with the advantage that it allowed greater accessibility for surgeons. Therefore, its use could be implemented and become widespread in surgical practice.

scholarly journals Suitable Turbine Selection based on the Parameters of a Potential Site at Sarawak, Malaysia

2020 ◽  
Vol 10 (6) ◽  
pp. 6399-6402
Author(s):  
K. A. Samo ◽  
I. A. Samo ◽  
W. Mughal ◽  
A. R. H. Rigit ◽  
A. A. Sohoo
Keyword(s):  
Energy Source ◽  
Renewable Energy Source ◽  
Renewable Energy ◽  
Flow Rate ◽  
Electrical Power ◽  
Maximum Flow ◽  
Tidal Range ◽  
Potential Site ◽  
The Mean ◽  
Suitable System

The tidal range is a renewable energy source. In Malaysia, most of the produced renewable energy is generated from the exploitation of the tidal range. The main purpose of this research is to determine a suitable system to produce tidal range energy from a potential site. A turbine selection chart is used. The mean tidal range of Kuching Barrage is 4.2m and the maximum flow rate over a gate is 226.9m3/s. Therefore, for the extraction of electrical power, a bulb-type turbine with a rated power of 5.2MW is identified as suitable to be deployed at the site.

scholarly journals Effect of Long-Term Creep on Microstructure of a 9% Cr Heat Resistant Steel

2014 ◽  
Vol 783-786 ◽  
pp. 1839-1844
Author(s):  
Valeriy Dudko ◽  
Alexandra Fedoseeva ◽  
Pavel Kozlov ◽  
Vladimir Skorobogatykh ◽  
Izabella Schenkova ◽  
...  
Keyword(s):  
Prior Austenite ◽  
Average Thickness ◽  
Resistant Steel ◽  
Secondary Phases ◽  
Heat Resistant Steel ◽  
Gauge Section ◽  
The Mean ◽  
Average Size ◽  
Term Creep

The effect of long-term creep at 600°C under 137 MPa on the microstructure of a P92-type steel was investigated. The microstructure after tempering consisted of laths with an average thickness of 400 nm. Dispersion of secondary phases consists of M23C6carbides with an average size of 85 nm located mainly on lath, block and prior austenite boundaries and MX carbonitrides with average size of 31 nm homogeniously distributed throughout. Creep with duration of 40738 hours led to coarsening of M23C6carbides up to 182 nm. Precipitation of Laves phase with an average size of 290 nm took place in both grip and gauge portions of ruptured specimen. Vanadium-rich MX particles were replaced by particles of Z-phase with sizes of 97 and 48 nm after long-term creep and aging, respectively. The average misorientation of the lath boundaries was approximately 2° and scarcely varied during creep, while the mean lath thickness increased to 890 nm in gauge section of ruptured specimen and remained essentially unchanged in the grip section. Dislocation density decreased slightly under long-range aging and creep.

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