Flumes and weirs

Presented at the 2002 USCID/EWRI conference, Energy, climate, environment and water - issues and opportunities for irrigation and drainage on July 9-12 in San Luis Obispo, California.Includes bibliographical references.Long-throated flumes and broad-crested weirs provide a practical, low-cost, flexible means of measuring open-channel flows in new and existing irrigation systems and have distinct advantages over other flume and weir devices. Application of these flumes and weirs has been greatly facilitated by the 1999 release of the WinFlume software used to design and calibrate these structures, and the recent publication of Water Measurement with Flumes and Weirs, a text providing comprehensive information on design, calibration, construction, and operation issues. The primary advantages of these flumes and weirs are that they can be custom-designed to satisfy unique operational and site requirements, and they can be computer calibrated without the need for laboratory testing. In addition, these devices are easily and economically constructed, and a number of commercially built, pre-calibrated devices are available. This paper and accompanying poster describe the use of the WinFlume software and present examples to illustrate application to a range of situations, including various flow rates, channel types, and construction techniques

Measuring the impact of health policies using Internet search patterns: the case of abortion

<p>Abstract</p> <p>Background</p> <p>Internet search patterns have emerged as a novel data source for monitoring infectious disease trends. We propose that these data can also be used more broadly to study the impact of health policies across different regions in a more efficient and timely manner.</p> <p>Methods</p> <p>As a test use case, we studied the relationships between abortion-related search volume, local abortion rates, and local abortion policies available for study.</p> <p>Results</p> <p>Our initial integrative analysis found that, both in the US and internationally, the volume of Internet searches for abortion is inversely proportional to local abortion rates and directly proportional to local restrictions on abortion.</p> <p>Conclusion</p> <p>These findings are consistent with published evidence that local restrictions on abortion lead individuals to seek abortion services outside of their area. Further validation of these methods has the potential to produce a timely, complementary data source for studying the effects of health policies.</p

Seasonal changes in patterns of gene expression in avian song control brain regions.

This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Photoperiod and hormonal cues drive dramatic seasonal changes in structure and function of the avian song control system. Little is known, however, about the patterns of gene expression associated with seasonal changes. Here we address this issue by altering the hormonal and photoperiodic conditions in seasonally-breeding Gambel's white-crowned sparrows and extracting RNA from the telencephalic song control nuclei HVC and RA across multiple time points that capture different stages of growth and regression. We chose HVC and RA because while both nuclei change in volume across seasons, the cellular mechanisms underlying these changes differ. We thus hypothesized that different genes would be expressed between HVC and RA. We tested this by using the extracted RNA to perform a cDNA microarray hybridization developed by the SoNG initiative. We then validated these results using qRT-PCR. We found that 363 genes varied by more than 1.5 fold (>log(2) 0.585) in expression in HVC and/or RA. Supporting our hypothesis, only 59 of these 363 genes were found to vary in both nuclei, while 132 gene expression changes were HVC specific and 172 were RA specific. We then assigned many of these genes to functional categories relevant to the different mechanisms underlying seasonal change in HVC and RA, including neurogenesis, apoptosis, cell growth, dendrite arborization and axonal growth, angiogenesis, endocrinology, growth factors, and electrophysiology. This revealed categorical differences in the kinds of genes regulated in HVC and RA. These results show that different molecular programs underlie seasonal changes in HVC and RA, and that gene expression is time specific across different reproductive conditions. Our results provide insights into the complex molecular pathways that underlie adult neural plasticity

Tests of Concepts for Streamflow Sampler Design

Total-load sampling has been a perpetual problem in sediment monitoring. Usually a combination of bed-load sampling devices, suspended load suction samplers, and some kind of flume, for total flow rate, is used. Total-load, sediment-sampler-design concepts that can perform all three of these functions are proposed. The resulting designs would require installation at sites that can provide a step-overfall height about equal to the maximum channel flow depth. The concepts are simple, but appear to have been overlooked or ignored for the past many decades, and are based on a moving conveyor belt that is long and wide, with many slots, all of the same size, onto which the stream to be sampled discharges. All flow drops through the slots, and with equal sized slots each must catch a similar proportion of the total flow. Hence, only one slot needs to be collected. As a practical extension it is proposed to replace the conveyor belt with a rack having several slots that represent a short section of the total conveyor belt that is large enough so that the flow does not notice the missing belt parts. This rack is then traversed back and forth on a track through the falling nappe. Laboratory tests of this proposed sampling-assembly rack indicated that the number of the required slots is related to the channel depth and the sum of the slot openings. When the rack is composed of sufficient slots so that the slot-width sum is more than half the channel overfall depth, the system undersampled from 0 to 2% but when there are insufficient slots whose sum represents less than one-third of the overfall depth, the system undersampled by over 8%. The concepts are extended to the condition with a stopped belt where several sampling-slot groups are equally spaced beneath the overfall. A “test of concept” sampler assembly of the stopped-belt idea was built and tested. The sample catch across the stream was within about 4% of expected, offering a total load sampling system where motorized equipment is difficult to install, or electric power is not available. Design and construction suggestions are presented. The catch rate can be small enough to facilitate convenient flow measurement of the catch, which can be converted to total streamflow without the need for separate channel flow measurements

USCID fourth international conference

Presented at the Role of irrigation and drainage in a sustainable future: USCID fourth international conference on irrigation and drainage on October 3-6, 2007 in Sacramento, California.Includes bibliographical references.Previous discussions concerning practical technologies that can encourage farmers to adopt practices supporting sustainable irrigated agriculture are updated. Important among these are convenient water measurement and control techniques. These techniques need to be available not only to the farmers, but also to the delivery system operators that make the system responsive to the on-farm needs. Improved irrigation planning and management techniques depend heavily on accurately controlling and quantifying water deliveries. Automation places a further burden on reliable operation of primary water measuring and flow control equipment. Many simple constructions and operating procedures can be provided to farmers and irrigation-delivery-system operators that offer considerable convenience at small expense and can be included in automation upgrades to improve reliability. Problems of reliability are aggravated if equipment is not easily field checked for proper functioning. Many observable clues, when they do exist, go unrecognized by inadequately trained personnel. This compilation of practices and design suggestions should help the operator assure valid measurement data and control functions. These suggestions are intended to make these devices easier to use, easier to verify, and more economical to construct and install. The techniques and devices discussed included: (a) accurate and convenient zero setting for weirs and flumes; (b) pressure-transducer field checks; (c) easy-to-use scales for orifice and Venturi meters; (d) wave suppressors for canals that flow at variable depths; (e) method for measuring Manning n values; and (f) flow-profile visualization using rising-bubble techniques to evaluate canal flow conditioning. Also included is a discussion of some pipe flow conditioning ideas used in field practice for devices installed in adverse conditions

USCID 14th technical conference

Presented at Contemporary challenges for irrigation and drainage: proceedings from the USCID 14th technical conference on irrigation, drainage and flood control held on June 3-6, 1998 in Phoenix, Arizona.Includes bibliographical references.Because many irrigation systems throughout the world are well into the late years of their economic design life, efforts presently are toward their rehabilitation and modernization. Modernization is widely recommended over simply rehabilitating to the original status. Several goals of modernization include providing flexible water delivery service that is responsive to modern, on-farm irrigation systems, such as drip, sprinkler, level basin, and surge. To adopt many of these technologies implies that the farm unit can control the water supply by being able to start and stop the delivery at will, or at least negotiate or specify start and stop times. This often is well served by canal automation, a tool that will play a prominent role in improving the operation of delivery systems. Automation techniques are still under development and may still be prohibitively costly for many applications. However, there are a number of structural and management changes that can be considered that require only limited automation, or no automation, and can still provide significant flexibility of irrigation delivery to the farm unit. These measures include combinations of canal level-control structures, field outlet structures, strategically placed off-line reservoirs, low-cost measurement devices, and canal operating procedures. How to retrofit these useable features into an existing system as part of the rehabilitation and modernization scheme is the major emphasis of the paper. These features usually improve the convenience of irrigation applications and can encourage better irrigation efficiency