420 research outputs found
Phosphine fumigation of cool grain
The biosecurity problem addressed was the need to understand and evaluate phosphine fumigation of cool grain (i.e. 20°C or less) as a means of controlling resistant biotypes of insect pests of stored grain which are major EPPs threatening the grain industry. The benefits of cooling and phosphine fumigation are that cooling preserves grain quality and reduces insect population growth, and phosphine kills insects and has a residue free status in all major markets.
The research objectives were to:
- conduct laboratory experiments on phosphine efficacy against resistant insects in cool grain, and determine times to population extinction.
- conduct laboratory experiments on phosphine sorption in cool grain and quantify.
- complete fumigation trials in three states (Queensland, WA and NSW) on cool grain stored insealed farm silos.
- make recommendations for industry on effective phosphine fumigation of cool grain.
Phosphine is used by growers and other stakeholders in the grain industry to meet domesticand international demands for insect-free grain. The project aim was to generate new information on the performance of phosphine fumigation of cool grain relevant to resistant biotypes. Effective control of resistant biotypes using phosphine to fumigate cool grain will benefit growers and other sectors of the grain industry, needing to fumigate grain in the cooler months of the year, or grain that has been cooled using aeration
High power RF input couplers and test stand for the BERLinPro Project
The bERLinPro project [1], under construction at HZB, is a 100 mA, 50 MeV superconducting RF SRF energy recovery linac ERL being built to study the accelerator technology and physics of operating a high current SRF ERL. For this high current operation, coaxial RF power couplers capable of handling 115 kW of power per coupler, dual couplers per cavity , continuous wave cw at 1.3 GHz are required for both the SRF photo injector and booster cavities. In order to sustain this power level a coupler has been designed based on the high power coupler currently in use at the KEK cERL. Two key changes that were made to the coupler were the modification of the coupler tip, termed a golf tee, as well as increased cooling of the inner conductor. This former modification is incorporated so as to achieve the desired coupling, Qext 105, with minimal coupler penetration into the beam pipe. Herein, we discuss the RF design and properties of the high power coaxial coupler for the photo injector as well as booster cavities of bERLinPro, along with the design of the test stand for conditioning a pair of coupler
Commissioning results of the HZB Quadrupole Resonator
Recent cavity results with niobium have demonstrated the necessity of a good understanding of both the BCS and residual resistance. For a complete picture and comparison with theory, it is essential that one can measure the RF properties as a function of field, temperature, frequency and ambient magnetic field. Standard cavity measurements are limited in their ability to change all parameters freely and in a controlled manner. On the other hand, most sample measurement setups operate at fairly high frequency, where the surface resistance is always BCS dominated. The quadrupole resonator, originally developed at CERN, is ideally suited for characterization of samples at typical cavity RF frequencies. We report on a modified version of the QPR with improved RF figures of merit for high field operation. Experimental challenges in the commissioning run and alternate designs for simpler sample changes are shown alongside measurement results of a large grain niobium sampl
Fading with light and greying with age in the fleece of black Australian Polwarth sheep
In order to measure the variation of colour related to some external and internal factors, 136 samples of wools were collected in 1979 and 1980 in a flock of black Polwarth sheep kept in the South of Victoria State, in Australia, 38 " latitude South in open air all year long. The genetic formula of these animals at Agouti, Brown and Extension loci was probably aa, B+B+, E+E+. The animals were female or wethers, they were rugged for control or non rugged with a coat opaque to visible and U.V. radiations and cut off at 2.5, 3.5 months or one year of wool growth. The colour measurements were made with a colour atlas based on the D.I.N. System. Except for very rare cases, the growing wool (at the base of the staple) was in the grey scale (which goes from pure white to jet black, without a hue component). With age one could see a greying or silvering of the coloured fleece. This is due to an increase in the number of white fibers and seems independant from light exposure. Due to exposure to solar radiation there was a fading of the staple to the range ot browns. This means the addition of a spectral colour component: the hue, orange in this case. The fading first affects the tip on the staple, about 2 cm after one year of exposure
Radiation-induced micronucleus induction in lymphocytes identifies a high frequency of radiosensitive cases among breast cancer patients: a test for predisposition?
Enhanced sensitivity to the chromosome-damaging effects of ionizing radiation is a feature of many cancer-predisposing conditions. We previously showed that 42% of an unselected series of breast cancer patients and 9% of healthy control subjects showed elevated chromosomal radiosensitivity of lymphocytes irradiated in the G2 phase of the cell cycle. We suggested that, in addition to the highly penetrant genes BRCA1 and BRCA2, which confer a very high risk of breast cancer and are carried by about 5% of all breast cancer patients, there are also low-penetrance predisposing genes carried by a much higher proportion of breast cancer patients, a view supported by recent epidemiological studies. Ideally, testing for the presence of these putative genes should involve the use of simpler methods than the G2 assay, which requires metaphase analysis of chromosome damage. Here we report on the use of a simple, rapid micronucleus assay in G0 lymphocytes exposed to high dose rate (HDR) or low dose rate gamma-irradiation, with delayed mitogenic stimulation. Good assay reproducibility was obtained, particularly with the HDR protocol, which identified 31% (12 out of 39) of breast cancer patients compared with 5% (2 out of 42) of healthy controls as having elevated radiation sensitivity. In the long term, such cytogenetic assays may have the potential for selecting women for intensive screening for breast cancer
RF input power couplers for high current SRF applications
present day accelerator science. The bERLinPro project is presently being built at HZB to address the challenges involved in high current SRF machines with the goal of generating and accelerating a 100 mA electron beam to 50 MeV in continuous wave cw mode at 1.3 GHz. One of the main challenges in this project is that of handling the high input RF power required for the photo injector as well as booster cavities where there is no energy recovery process. A high power co axial input power coupler is being developed to be used for the photo injector and booster cavities at the nominal beam current. The coupler is based on the KEK cERL design and has been modified to minimise the penetration of the coupler tip in the beam pipe without compromising on beam power coupling Qext 105 . Herein we report on the RF design of the high power 115 kW per coupler, dual couplers per cavity bERLinPro BP coupler along with initial results on thermal calculations. We summarise the RF conditioning of the TTF III couplers modified for cw operation performed in the past at BESSY HZB. A similar conditioning is envisaged in the near future for the low current SRF photo injector and the bERLinPro main linac cryomodule
- …