Research on irrigation of corn and soybeans at Conesville and Ankeny, Iowa, 1951 to 1955

Irrigation in the humid and semihumid sections of the United States has increased manyfold since World War II. Before this, irrigation was confined principally to the more arid western states. Some of the reasons for the spread to more humid areas were the development of portable lightweight aluminum pipe and couplers, moderately high farm prices, occurrence of several drouthy seasons, increased use of fertilizers and development of better crop varieties. Drouths in various portions of the state in 1953, 1954, 1955 and 1956 have prompted many farmers to buy irrigation equipment. A 1953 survey in Iowa showed that only 55 farmers were irrigating about 3,600 acres. Twenty-two of these farmers were in Muscatine County where irrigation is used on vegetable crops. Two years later, in 1955, another survey indicated that 250 farmers were irrigating approximately 15,000 acres. Indications are that irrigation will continue to increase, particularly along the Mississippi and Missouri rivers. Along the Missouri River there are about 600,000 acres of bottomland. Most of this area needs better surface drainage. Without too much additional cost, land which is surface drained can be shaped for surface irrigation. Because of good ground water supplies, this area has a high irrigation potential. These conditions also exist to a more limited extent along other major Iowa streams

Product assurance technology for custom LSI/VLSI electronics

The technology for obtaining custom integrated circuits from CMOS-bulk silicon foundries using a universal set of layout rules is presented. The technical efforts were guided by the requirement to develop a 3 micron CMOS test chip for the Combined Release and Radiation Effects Satellite (CRRES). This chip contains both analog and digital circuits. The development employed all the elements required to obtain custom circuits from silicon foundries, including circuit design, foundry interfacing, circuit test, and circuit qualification

Open Space – a collaborative process for facilitating Tourism IT partnerships

The success of IT projects depends on the success of the partnerships on which they are based. However past research by the author has identified a significant rate of failure in these partnerships, predominantly due to an overly technical mindset, leading to the question: “how do we ensure that, as technological solutions are implemented within tourism, due consideration is given to human-centred issues?” The tourism partnership literature is explored for additional insights revealing that issues connected with power, participation and normative positions play a major role. The method, Open Space, is investigated for its ability to engage stakeholders in free and open debate. This paper reports on a one-day Open Space event sponsored by two major intermediaries in the UK travel industry who wanted to consult their business partners. Both the running of the event and its results reveal how Open Space has the potential to address some of the weaknesses associated with tourism partnerships

The Periodic Standing-Wave Approximation: Overview and Three Dimensional Scalar Models

The periodic standing-wave method for binary inspiral computes the exact numerical solution for periodic binary motion with standing gravitational waves, and uses it as an approximation to slow binary inspiral with outgoing waves. Important features of this method presented here are: (i) the mathematical nature of the ``mixed'' partial differential equations to be solved, (ii) the meaning of standing waves in the method, (iii) computational difficulties, and (iv) the ``effective linearity'' that ultimately justifies the approximation. The method is applied to three dimensional nonlinear scalar model problems, and the numerical results are used to demonstrate extraction of the outgoing solution from the standing-wave solution, and the role of effective linearity.Comment: 13 pages RevTeX, 5 figures. New version. A revised form of the nonlinearity produces better result

Book Reviews

TO SECURE THESE RIGHTS The Report of the President\u27s Committee on Civil Rights with An Introduction by Charles S. Wilson, Committee Chairman. New York: Simon and Schuster, 1947. Pp. xii, 178. $1.00.. ====================== ROSCOE POUND By Paul Sayre Iowa City: College of Law Committee State University of Iowa, 1948. Pp. 412.$4.50. ====================== A NATIONAL POLICY FOR THE OIL INDUSTRY By Eugene V. Rostow New Haven: Yale University Press, 1948. Pp. XVI, 173. $2.50. ===================== THE TRADE OF NATIONS By Michael A. Heilperin New York: Alfred A. Knopf, 1947. Pp. xix, 234.$3.00. ==================== AMERICA\u27S ECONOMIC SUPREMACY By Brooks Adams New York: Harper & Brothers, Inc., 1947. Pp. 194. $2.50

Electron-beam propagation in a two-dimensional electron gas

A quantum mechanical model based on a Green's function approach has been used to calculate the transmission probability of electrons traversing a two-dimensional electron gas injected and detected via mode-selective quantum point contacts. Two-dimensional scattering potentials, back-scattering, and temperature effects were included in order to compare the calculated results with experimentally observed interference patterns. The results yield detailed information about the distribution, size, and the energetic height of the scattering potentials.Comment: 7 pages, 6 figure

Going places

Journeys. We all make them. Often they take us to exotic places. Sometimes they take us even further. They might take us through time. Or they might take us into a new way of life. There are times too, when we go all over the world and back again only to find that home is, after all, where it’s all happening. This book contains stories about many different types of journey. We hope you will enjoy travelling into it and finding a world that suits you

Probing the potential landscape inside a two-dimensional electron-gas

We report direct observations of the scattering potentials in a two-dimensional electron-gas using electron-beam diffaction-experiments. The diffracting objects are local density-fluctuations caused by the spatial and charge-state distribution of the donors in the GaAs-(Al,Ga)As heterostructures. The scatterers can be manipulated externally by sample illumination, or by cooling the sample down under depleted conditions.Comment: 4 pages, 4 figure

The (p,n) Reaction at Intermediate Energies with the Isotopes of Oxygen (16-O, 17-O, 18-O) and 9-Be as Part of a Unified Approach to the Study of These Nuclei

This work was supported by National Science Foundation Grants PHY 76-84033A01, PHY 78-22774, and Indiana Universit