Water erosion control - 3

Contour Bank is the name applied to a ridge or bank of earth built across sloping ground between points of equal or nearly equal heights. The basic function of a contour bank is interception of run-off water is then either absorbed or conducted slowly from the land, depending on the condition of the soil conservation work contour banks are not a substitute for, but supplementary to, suitable plant cover and careful land management

The hose u-tube level

With the growing use of soil conservation practices throughout the farming areas, there has been an increasing demand for a simple levelling device that will enable farmers to take their own levels. When they have become familiar with the use of pasture furrows, contour banks and the various other mechanical erosion control measures, farmers with the aid of such an instrument would be able to make an immediate start on an erosion control programme. The instrument would also prove useful for numerous small jobs around the farm when accurate levels are required. Tests have shown the Hose U-Tube Level here described, to be an accurate and reliable farm levelling instrument

Holocene-Neogene volcanism in northeastern Australia: chronology and eruption history

Quaternary and late Neogene volcanism is widespread in northeastern Australia, producing at least 397 eruptions covering more than 20,000 km2, including at least 20 flows over 50 km long. Despite this abundance of young volcanism, before this study numerous eruptions had tentative ages or were undated, and the area requires a comprehensive evaluation of eruption patterns through time. To help address these issues we applied multi-collector ARGUS-V 40Ar/39Ar geochronology to determine the age of four of the younger extensive flows: Undara (160 km long, 189 ± 4/4 ka; 2σ, with full analytical/external uncertainties), Murronga (40 km long, 153 ± 5/5 ka), Toomba (120 km long, 21 ± 3/3 ka), and Kinrara (55 km long, 7 ± 2/2 ka). Verbal traditions of the Gugu Badhun Aboriginal people contain features that may potentially describe the eruption of Kinrara. If the traditions do record this eruption, they would have been passed down for 230 ± 70 generations – a period of time exceeding the earliest written historical records. To further examine north Queensland volcanism through time we compiled a database of 337 ages, including 179 previously unpublished K-Ar and radiocarbon results. The compiled ages demonstrate that volcanic activity has occurred without major time breaks since at least 9 Ma. The greatest frequency of eruptions occurred in the last 2 Ma, with an average recurrence interval of <10–22 ka between eruptions. Activity was at times likely more frequent than these calculations indicate, as the geochronologic dataset is incomplete, with undated eruptions, and intraplate volcanism is often episodic. The duration, frequency, and youthfulness of activity indicate that north Queensland volcanism should be considered as potentially still active, and there are now two confirmed areas of Holocene volcanism in eastern Australia – one at each end of the continent. More broadly, our data provides another example of 40Ar/39Ar geochronology applied to Holocene and latest Pleistocene mafic eruptions, further demonstrating that this method has the ability to examine eruptions and hazards at the youngest volcanoes on Earth

Commercial production of tomatoes in Western Australia

The tomato crop is subject to many hazards. Pests, diseases and adverse environmental conditions are frequently encountered and must be overcome. This bulletin has been prepared to give growers, whether they be experienced or new to tomato culture, an outline of the more important cultural practices involved in producing satisfactory crops. Common diseases and pests are described and where possible recommendations for their control are given.https://researchlibrary.agric.wa.gov.au/bulletins3/1004/thumbnail.jp

Point Source C-Band Mueller Matrices for the Green Bank Telescope

C-Band Mueller matrices for the Green Bank Telescope are presented here which enable on-sky Stokes parameters for point sources at the beam center to be determined. Standard calibrators, 3C138 and 3C286, were observed using the Spider program to steer the telescope across a broad range of Right Ascensions on both sides of the zenith transit. For this analysis, only the observations at the peak of the Spider pattern were used rather than the full sweep of the runs. Therefore, the results presented here only apply to point sources at the beam center. The Mueller matrices are shown to vary with frequency and with use of the Hi-Cal or Lo-Cal noise diodes, due to the relative calibration gain between the X and Y components of the feed. However, the relative calibration gain can be determined from observations of a source with known polarization. Correcting the data for the relative calibration gain prior to data analysis allows for use of a frequency independent Mueller matrix. This generic Mueller matrix is shown to provide reliable C-Band polarization measurements.Comment: Acceptance for publication in The Astronomical Journa

Relative spins and excitation energies of superdeformed bands in 190Hg: Further evidence for octupole vibration

An experiment using the Eurogam Phase II gamma-ray spectrometer confirms the existence of an excited superdeformed (SD) band in 190Hg and its very unusual decay into the lowest SD band over 3-4 transitions. The energies and dipole character of the transitions linking the two SD bands have been firmly established. Comparisons with RPA calculations indicate that the excited SD band can be interpreted as an octupole-vibrational structure.Comment: 12 pages, latex, 4 figures available via WWW at http://www.phy.anl.gov/bgo/bc/hg190_nucl_ex.htm