Droplet evaporation losses during sprinkler irrigation: an overview

A detailed understanding regarding the evaporation losses in sprinkler irrigation is important for developing as well as adopting appropriate water conservation strategies. To explain this phenomenon many theoretical and experimental studies have been conducted since the 1950‟s. Notwithstanding all these efforts, the contribution of droplet evaporation to the total evaporation losses during sprinkler irrigation is still a controversial issue in the irrigation community. There is a substantial difference among researchers regarding the magnitudes of the different components of the total evaporation in sprinkler irrigation especially droplet evaporation losses. Field studies reported that the droplet evaporation losses ranged from 2 – 45%, whereas theoretical studies indicated that it is less than 1%. This is due largely to the limitations of the traditional measurement methods. However, it is likely that these limitations can be overcome and accurate measurements obtained using the eddy covariance (ECV) technique

The Tangled Web: A Case Against New Generic Top-Level Domains

If we had a reliable way to label our toys good and bad, it would be easy to regulate technology wisely. But we can rarely see far enough ahead to know which road leads to damnation

The Tangled Web: A Case Against New Generic Top-Level Domains

This article’s purpose is to provide a general understanding of the legal and financial implications of the new generic top-level domains. By looking at the history and functionality of generic top-level domains, the reader will hopefully have the requisite background to understand the implications of adding new top-level domains

Water consumption of an evaporative cooling system in the midwest

Dairy Research, 2009 is known as Dairy Day, 2009Water meters were installed on the evaporative cooling system of a long, low-profile, cross-ventilated dairy in the upper Midwest. The evaporative pad along the west side measured 10 by 350 ft. The water usage per unit surface area of the evaporative pad was 0.29 gallons/hour per square foot of evaporative pad surface area. The total daily water usage per stall averaged 13 gallons with a maximum of 22.7 gallons. Results from this study indicate that peak hourly water usage may be as much as 3 times the average values. The evaporative pad efficiency was 65% between noon and 0800 hours and 79% between midnight and 0400 hours

Rapid detection and quantification of features such as damage or flaws in composite and metallic structures

An apparatus, system, and method for non-destructible evaluation (NDE) of a material use thermography to rapidly detect and/or generally locate a feature such as, for example, damage or a defect in the material. The apparatus, system, and method also use ultrasound to specifically locate the feature in the material for quantification and/or evaluation either by an operator or by an external device suited for such purpose. Accordingly, the apparatus, system and method are particularly useful for NDE in applications such as the analysis of the structure of an aircraft, for example, in which the scale of the material to be analyzed is large, thus requiring the rapid NDE afforded by thermography, and in which quantification and/or evaluation of a feature must be performed with precision, thus requiring the relatively high-resolution NDE afforded by ultrasound

Detection of bondline delaminations in multilayer structures with lossy components

The detection of bondline delaminations in multilayer structures using ultrasonic reflection techniques is a generic problem in adhesively bonded composite structures such as the Space Shuttles's Solid Rocket Motors (SRM). Standard pulse echo ultrasonic techniques do not perform well for a composite resonator composed of a resonant layer combined with attenuating layers. Excessive ringing in the resonant layer tends to mask internal echoes emanating from the attenuating layers. The SRM is made up of a resonant steel layer backed by layers of adhesive, rubber, liner and fuel, which are ultrasonically attenuating. The structure's response is modeled as a lossy ultrasonic transmission line. The model predicts that the acoustic response of the system is sensitive to delaminations at the interior bondlines in a few narrow frequency bands. These predictions are verified by measurements on a fabricated system. Successful imaging of internal delaminations is sensitive to proper selection of the interrogating frequency. Images of fabricated bondline delaminations are presented based on these studies

Futures Prices in Supply Analysis: Are Instrumental Variables Necessary?

Citation: Nathan P. Hendricks, Joseph P. Janzen, Aaron Smith; Futures Prices in Supply Analysis: Are Instrumental Variables Necessary?, American Journal of Agricultural Economics, Volume 97, Issue 1, 1 January 2015, Pages 22–39, https://doi.org/10.1093/ajae/aau062Crop yield shocks are partially predictable—high planting-time futures prices have tended to indicate that yield would be below trend. As a result, regressions of total caloric production on futures prices produce estimates of the supply elasticity that are biased downwards by up to 75%. Regressions of the world’s growing area on futures prices have a much smaller bias of about 20% because although yield shocks are partially predictable, this predictability has a relatively small effect on land allocation. We argue that the preferred method for estimating the crop supply elasticity is to use regressions of growing area on futures prices and to include the realized yield shock as a control variable. An alternative method for bias reduction is to use instrumental variables (IVs). We show that the marginal contribution of an IV to bias reduction is small—IVs are not necessary for futures prices in supply analysis

Tower tank valve flushing system for dairy facitlites

Flushing characteristics of a tower tank valve flushing system with a 12-inch-diameter manual valve were determined. Data were obtained using the outside cow alleys in a fourrow freestall barn. The alleys were 12 ft wide and 420 ft long with a 2% slope. The average flow rate exceeded 8,000 gallons per minute (gpm) when the average head was above 30 ft and the manual valve opened 80 degrees. Opening the valve to 90 degrees increased the flow rate to over 9,700 gpm. The velocity of the flushing wave was 8.5 fpm with a flow depth of 3.5 in. The estimated wave duration or alley contact time was 14.6 sec with a 25-40 sec release time from the flush tank. The flow rate ranged from 5,300 gpm to 7,200 gpm when the average head was between 16 and 28 ft.; Dairy Day, 1998, Kansas State University, Manhattan, KS, 1998