Oving Eigenvalues and Eigenvectors

The Office of Naval Research Department Of The Navy Contract No. N 00014-67-A-0305-0010 ; Project No. NR 064-183/5-28-70(439

Wave Propagation in an Elastic Half Space Due to Couples Applied at a Point Beneath the Surface

Office of Naval Research. Department of the Navy: Contract No. N00014-67-A-0305-0010; Project No. NR 064-183U.S. Army Research Office - Durham: Project No. D0161102B33G, Proposal No. D-5

The Analgesia-Enhancing Component of\ud Ingested Amniotic Fluid Does Not Affect\ud Nicotine-Induced Antinociception in\ud Naltrexone-Treated Rats

Ingestion of amniotic fluid and placenta by rats has been shown to enhance opioid-mediated antinociception but not affect the nonopioid-mediated antinociception produced by aspirin, suggesting spccificity for opioid-mediated processes. However, enhancement by the active substance(s) in amniotic fluid and placenta1 (POEF, for placental opioid-enhancing factor) of antinociception produced by other nonopioid mechanisms has yet to be examined. The present experiments tested whether ingestion of amniotic fluid enhances the antinociception produced by nicotine injection. In Experiment IA, Enhancement of morphine-mediated antinociception by ingestion of amniotic fluid was demonstrated in a hot-plate assay. In Experiment IB, rats pretreated with naltrexone were given an orogastric infusion of amniotic fluid or control (0.25 ml), then injected with nicotine (0, 0.075, 0.125, or 0.225 mg/kg subcutaneously), then tested for antinociception in a hot-plate assay. Amniotic fluid ingestion did not enhance the antinociception produced by various doses of nicotine. In Experiment 2, rats pretreated with naltrexone were given an orogastric infusion of amniotic fluid (0, 0.125,\ud 0.25, or 0.50 ml) and then injectcd with 0.125 mg/kg nicotine. None of the doses of amniotic fluid enhanced the nicotine-induced antinociception. The findings of these experiments lend support to our contention that the enhancement by POEF of antinociception is specific to opioid-mediated processes

Trapezoidal Flumes for Measuring Flow in Irrigation Channels

Experience and research have shown that, in many respects, trapezoidal flumes are superior to the rectangular or Parshall-type flumes, particularly for measuring_ smaller flows. The shape conforms to the normal shape of ditches, particularly those that are lined. This minimizes the amount of transition section needed as compared to that required when changing from a trapezoidal shape to a rectangular one and back to the trapezoidal. The trapezoidal shape is also desirable since the sidewalls expand as the depth increases. This means that one structure can convey a larger range of flow. Also, the entire range of depth for a given range of discharge is smaller. Operational characteristics of trapezoidal flumes are also superior. Generally, less backwater will result and a shallower section Will be required than for a rectangular shape. Another desirable feature of the trapezoidal flume is the flat bottom throughout rather than a dropped section such as with the Parshall flume. No particular advantage of a crest section with a drop in the floor such as that in the Parshall flume has been found. The trapezoidal flume will operate under a higher degree of submergence than the Parshall flume without corrections being necessary. The loss in head, i.e., total head loss, through the trapezoidal structure, may be less for comparable discharges

Discussion: Analysis of Submergence in Flow Measuring Flumes

This paper presents another contribution to the understanding of flow phenomena for measuring flumes. The particular regime of submerged flow has been largely neglected, although there have been a number of attempts to establish criteria and methods for analyzing submerged flow as referenced by the authors. The common approach has been to develop the theory to a point and then proceed with an empirical and experimental approach. In this manner it has been possible to develop relationships which are usable for particular flumes of given geometry. However, because of the empirical approach, it is not possible to use the relationships for designs other than those for which they were developed. This paper also summarizes a study for particular design geometries and has contributed to the knowledge of submerged flow. There still exists the need for good, sound theoretical developments so that the relationships include the geometry of the measuring flume, as well as those items usually assumed to be of negligible effect, such as frictional losses and nonuniform velocity distribution. The geometry variables have been included for the free flow case by Ackers and Harrison with apparent success. Flume geometry is important since such things as length of throat, contraction ratio (B), shape of section (rectangular or trapezoidal), and geometry of the downstream diverging section all contribute to submergence effects

Evaluation of the Vane-Type Flow Meter

THE vane-type flow meter was calibrated for a range of operating conditions both in the hydraulics laboratory at Colorado State University and through a field trial. Three meters were tested, all of which were made for a 2-ft rectangular section. Each of the meters was a production model furnished by the manufacturer

The USDA Snake River Conservation Research Center - Its Design, Development and Program

The Snake River Conservation Research Center is a newly completed facility located in south-central Idaho. The Center is designed for conducting basic and applied research studies on soil and water problems existing throughout the upper Snake River Plains and the surrounding region. The Center is unique in many respects. It is located in the center of a large agricultural area and is designed for scientists to conduct basic research under controlled laboratory conditions and guide the research through closely controlled trials and to eventual field application. The research program is cooperative with the University of Idaho Experiment Stations and other state and federal agencies

Discussion: Rectangular Cutthroat Flow Measuring Flumes

The authors have presented a new design for flow measuring flumes. The flumes have a rectangular section and flat bottom, and do not have a throat section such as is provided for conventional measuring flumes. The unique feature of this design is the standard sidewall sections, which are used for all flumes ranging from 1 ft to 6 ft in throat width. In other words, the same design and length of converging and diverging sections are used for all throat widths. The authors state that "the use of a consistent geometric shape allows accurate predictions of discharge ratings for intermediate flume sizes." In addition to the rectangular flumes presented in this paper, the authors also have designed and calibrated trapezoidal cutthroat flumes, that do not have a throat section. The simplicity of the flumes is obvious and, from the information presented by the authors, it appears that they have many desirable features. The extent of field experience with the device is not given. It is assumed that the authors have had experience other than the laboratory calibrations in order to observe any particular field problems which are not apparent under laboratory conditions

Simplified Flow Corrections for Parshall Flumes Under Submerged Conditions

Parshall flumes are widely used for measuring flow in canals, domestic water supply and sewage systems, and to a limited extent in natural streams. Normally, the device operates like a weir, the flow being contracted and passing through a critical depth. This condition is termed free flow and only one depth measurement, ha, in the converging section is required to determine the flow. The discharge is given by the general relationship, Q = K ha in which K and n are constant for a given size but vary for different sizes. Standard design data and calibration tables are available for flume sizes ranging in throat width from 1 in. to 50 ft, and in discharge from 0.01 to 3,300 cfs. One particular advantage of using flumes rather than weirs is that the head loss is less, that is, there is a smaller change in the depth of the flow as it passes through the structure

Water Measurement in Small Irrigation Channels Using Trapezoidal Flumes (Gen. Ed.)

THE use of trapezoidal flumes for water measurement is increasing. Research and development has shown trapezoidal flumes in many cases to be more adaptable and more easily constructed than conventional rectangular flumes. Trapezoidal flumes are used to measure flows in natural streams and in irrigation canals and small furrows. Results of research on trapezoidal flumes at the Colorado State University hydraulics laboratory prior to 1959 have previously been published (5)*. This report presents the results of research on small trapezoidal flumes for irrigation channels