1,720,993 research outputs found
Wind Energy Feasibility and Energy Education Project Lower Sioux Community
No full textThe results of wind speed and direction measurements carried out in the Lower
Sioux Community during the twelve~month period from November 1, 1995, to October
31, 1996, are reported. The measurement were performed using six wind anemometers
and six wind direction vanes installed at four sites in the community. The data presented
include the monthly averages of the semi~hour1y wind speeds and of their cubes, monthly
wind roses, the probability distributions of the wind speeds and the parameters of Wei bull
distributions fitted to them, turbulence intensity data, and total energy roses for each
month.
The data are presented so as to streamline a comparison with wind energy data at
other area sites where comparable records may be available. Possible sites and
methodology for such a comparison and errors which may arise in a potential
extrapolation of the twelve-month record to longer time periods are discussed.Office of the Environment Lower Sioux CommunityFarell, Cesar; Ellis, Christopher R.. (1997). Wind Energy Feasibility and Energy Education Project Lower Sioux Community. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/131872
A Hydraulic Model Study of Navigation Improvement in the Upstream Approach to Locks and Dam No. 2, Mississippi River
No full textLocks and Dam No. 2 are located on the Mississippi River, 1.4 miles
above Hastings, Minnesota, and 26 miles south of St. Paul, Minnesota. The
structures are 815.2 river miles above the mouth of the Ohio River, 32.4
river miles below Locks and Dam No.1, and 17.3 river miles above Locks
and Dam No.3. Locks and Dam No. 2 were put into operation in 1931 as
part of the Army Corps of Engineers Mississippi River 9-foot channel
navigation project. Today they consist of twenty 30 ft tainter gates and two
locks on the southwest side of the river. The riverward lock is presently
non-operational.U. S. Army Corps of EngineersGroethe, Jon; Ellis, Christopher R.; Stefan, Heinz G.. (1988). A Hydraulic Model Study of Navigation Improvement in the Upstream Approach to Locks and Dam No. 2, Mississippi River. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/114034
Heating and Cooling of a Shallow Bay in Eau Galle Reservoir: Field Measurements and Interpretation
No full textWater quality concerns associated with the distribution of nutrients in
lakes and reservoirs make information on naturally occurring processes, which
affect water movement, of significant value. These processes can be driven
by wind, rain, solar radiation, surface cooling, photosynthetic activity,
ground water intrusion and Coriolis forces. This study focuses on the
diurnal effects of radiative heating and convective surface cooling as the
driving forces of change in the water temperature profiles. It has been
shown that the horizontal temperature gradients caused by the heating and
cooling of littoral waters, and the density differences associated with these
temperature gradients, cause horizontal and vertical exchange of water within
the littoral and adjacent profundal regions (Stefan, Horsch and Barko, 1989).Waterways Experiment StationSilver, Craig A,; Ellis, Christopher R.; Stefan, Heinz G.. (1989). Heating and Cooling of a Shallow Bay in Eau Galle Reservoir: Field Measurements and Interpretation. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/114159
Fairview Riverside Medical Center Helistop, Minneapolis, Minnesota: Design and Operational Issues
No full textAn analysis of wind conditions and aerodynamic design for the rooftop
helideck of the Fairview Riverside Medical Center, Minneapolis, Minnesota, is
presented, based on an extensive literature search and the examination of current
Federal Aviation Administration and Civil Aviation Authority (United Kingdom)
guidelines. The following points are examined: pilot comments following the opening
of the facility; the advisability of. a model study; the need for field wind
measurements; the configuration of the helideck, including its location on the rooftop,
dimensions, and the size of the air gap under it; and the effects of rotor downwash
and temperature on helicopter power and lift. Recommendations for site
measurement of wind characteristics and additional future work are given.University of Minnesota Hospital FacilitiesFarell, Cesar; Sitheeq, M. Mohamed; Ellis, Christopher R.; Voigt, Richard L. Jr.. (1995). Fairview Riverside Medical Center Helistop, Minneapolis, Minnesota: Design and Operational Issues. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/109290
Hydro-aesthetic improvement of St. Anthony Falls spillway at low flow
No full textThe possible expansion of hydropower development at St. Anthony Falls on the Mississippi River within the City of Minneapolis is likely to generate questions on the future appearance of the St. Anthony Falls spillway when most of the riverflow is routed through the existing powerplant and a projected additional power station. In particular, it may be asked how the aesthetics of the St. Anthony Falls spillway can be enhanced when only a small (minimum) flow is discharged over the spillway. It is anticipated that minimum flow spillway discharge will occur for 10 months in an average year when the proposed hydropower facility becomes operational. To study this particular question, an experimental study was conducted at St. Anthony Falls Hydraulic Laboratory and small flow deflectors which can be attached to the spillway surface and generate a "roostertail-like" spray were devised to make the appearance of the spillway more pleasing. The methods used in the study and the recommended design modifications are described in this report. It was not the intent of this study to determine what the minimum flow over the spillway should be, but rather to determine the best aesthetic effects on the spillway that can be accomplished at a low flow.NORTHERN STATES POWER COMPANY
Minneapolis, MinnesotaStefan, Heinz G.; Ellis, Christopher R.; Johnson, Thomas R.. (1986). Hydro-aesthetic improvement of St. Anthony Falls spillway at low flow. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/113560
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Pressure Loss Coefficients of 6, 8 and 10-inch Steel Pipe Fittings
No full textThe scope of this study includes the testing of 6, 8 and 10-inch wrought steel fittings with
flowing water to determine their head loss coefficient values. The fittings comprise long
elbows, reducing and expansion elbows, Tees, reducing Tees, concentric reducers and
expansions. Sixty fittings from seven manufacturers (four manufacturers per fitting)
were tested at specified ranges of flow velocities to determine their head loss coefficients.
In addition, an uncertainty analysis was conducted to determine the errors associated with
the test set-up, the instrumentation, and the procedures used for these tests. The head loss
coefficients of the fittings and their ranges are presented in this report as a function of
upstream flow velocity and the Reynolds number.
The results of the study show that the K-value of long elbows is smallest for larger pipe
fittings and increases as the pipe fitting size decreases. For branching flows in Tees, the
K-value of the straight leg is very similar to those in reducing Tees. However, for
branching flows in reducing Tees, the K-value of the branching leg varies with size and
the percent reduction in flow area. The K-values of reducers and expansions show a
weak dependence on upstream velocity. They are dependent on both the fitting size, and
the percent reduction and expansion of the flow area.American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc.Ding, Chengwei; Carlson, Luke; Ellis, Christopher R.; Mohseni, Omid. (2005). Pressure Loss Coefficients of 6, 8 and 10-inch Steel Pipe Fittings. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/113368
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