Atmospheric aerosols: A literature summary of their physical characteristics and chemical composition

This report contains a summary of 199 recent references on the characterization of atmospheric aerosols with respect to their composition, sources, size distribution, and time changes, and with particular reference to the chemical elements measured by modern techniques, especially activation analysis

Doing interdisciplinarity: motivation and collaboration in research for sustainable agriculture in the UK

This paper studies knowledge production in complex, collaborative research projects which brought together academics of different disciplines, research users and agricultural businesses. It takes a comparative approach, studying the interactions within interdisciplinary research teams from 10 case studies, considering the process of collaboration from initial idea through to publication. The research developed a typology of participants in these projects, and identified the motivations and challenges of each. Our results analyse the process of research teams coming together and the relationships which are built up during the research. A particular challenge identified was the building of cooperation and trust. This issue is explored alongside issues of communication, methodology, data analysis and the process of drawing and publicising conclusions

Circular No. 15 - Pastures and Pasture Grasses for Utah

Since the earliest records of man his domestic animals have secured a large proportion of their forage from pastures. Before crops were planted and harvested by man the wild grasses furnished the chief food for numerous kinds of animals, and the cutting and curing of hay came as a later development to supplement natural pasturage in seasons of scarcity

Circular No. 41 - Soil Alkali

The farmer of the West is likely to be very much upset at the mention of alkali, mineral, or salt, in connection with his land. These various names are applied to a condition which he usually knows little about except that it is bad. The exact nature of the substances called by these names and the character of the injuy caused by them are very vague in his mind; but he knows that he wants nothing to do with alkali if he can help it. The prevalence of alkali throughout the arid parts of the world makes it impossible for farmers in these regions to be entirely unaffected. The only alternative is to learn as much as possible about the condition and prepare to meet it squarely. All sections are not equally affected by alkali, but the soils of no large irrigated area are entirely free from it. The fact that the better lands have been taken makes it necessary next to use some of the soils that are to an extent affected by alkali if the farm products of the arid parts of the world are to be increased

Circular No. 44 - The Agriculture of Utah

Agriculture is so intimately related to all other industries that anything which affects the farmer reflects itself in all branches of business. The banker, the merchant, and the manufacturer must keep in touch with crop and livestock conditions of the country in order to foresee the tendencies of their own businesses. This is particularly true in a state like Utah which depends fundamentally on the products of the soil for its prosperity. Numerous requests are received by the Experiment Station from prospective settlers living out side of the state for information concerning the agriculture of Utah. These have been kept in mind in the preparation of this circular. It is also hoped that the facts herein presented will be of interest to farmers and business men within the state who wish to inform themselves more fully regarding its agricultural conditions and outlook

On the absence of Shapiro-like steps in certain mesoscopic S-N-S junctions

In DC transport through mesoscopic S-N-S junctions, it is known that the Josephson coupling decreases exponentially with increasing temperature, but the phase dependence of the conductance persists to much higher temperatures and decreases only as 1/T. It is pointed out here that, despite the fact that such a phase-dependent conductance does bring about an AC current for a pure DC voltage, it cannot, by itself, lead to the formation of Shapiro steps.Comment: 1 page, to be published in PRL (as Comment

Spontaneous Raman scattering as a high resolution XUV radiation source

A type of high resolution XUV radiation source is described which is based upon spontaneous anti-Stokes scattering of tunable incident laser radiation from atoms excited to metastable levels. The theory of the source is summarized and two sets of experiments using He (1s2s)(1)S atoms, produced in a cw hollow cathode and in a pulsed high power microwave discharge, are discussed. The radiation source is used to examine transitions originating from the 3p(6) shell of potassium. The observed features include four previously unreported absorption lines and several sharp interferences of closely spaced autoionizing lines. A source linewidth of about 1.9 cm(-1) at 185,000 cm(-1) is demonstrated

Wintertime losses of ozone in high northern latitudes

Total column ozone data over the past 22 to 30 years from ground-based Dobson and filter ozonometer stations between 30 N and 80 N are analyzed for residual trends remaining after allowance for the known geophysical variations corresponding to: (1) the change of seasons; (2) the quasi-biennial oscillation; and (3) the 11-year solar sunspot cycle. Examination of the data from several ground stations between 45 and 55 N indicated a seasonal difference in the long-term ozone series, with statistically significant losses in several winter months. Accordingly, the data from individual stations were analyzed with multiple regression analysis, seeking trends on a monthly basis after allowance for the known geophysical cycles. Previous statistical analyses were conducted as tests of 1-D model calculations which do not show any differences with the seasons, and any trend toward change in ozone concentrations is expressed in a yearly trend without seasonal variation. Such a model is inappropriate for calculations with a data set which exhibits a pronounced tendency toward seasonal differences in the trends. Comparisons with model calculations then require 2-D models into which seasonal and latitudinal differences can easily be programmed

Vacuum ultraviolet holography

The authors report the first demonstration of holographic techniques in the vacuum ultraviolet spectral region. Holograms were produced with coherent 1182 A radiation. The holograms were recorded in polymethyl methacrylate and read out with an electron microscope. A holographic grating with a fringe spacing of 836 A was produced and far-field Fraunhofer holograms of sub-micron particles were recorded

Studies of laser and laser devices

The generation of tunable, infrared, and ultraviolet light, and the control of this light by mode-locking and modulation techniques are discussed. Particular emphasis is given to energy storage and extraction using atomic levels, the development of a tunable narrowband vacuum ultraviolet light source, and to the generation and applications of ultrashort optical pulses