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Douglas Nakashima, United Nations Educational, Scientific and Cultural Organization (UNESCO), France,Igor Krupnik, Smithsonian Institution, Washington DC,Jennifer T. Rubis, United Nations Educational, Scientific and Cultural Organization (UNESCO), France
An evaluation of the risk-reducing effectiveness of the Livestock Gross Margin–Dairy (LGM-Dairy) insurance program, using historical futures price data, predicts economically significant reductions in downside margin risk (24–41%) across multiple regions. Supply analysis based on the estimated risk reduction shows a small supply response, assuming minimal subsidization. A decomposition of the simulated indemnities into milk price and feed price components shows comovements in futures prices moderating the frequency and levels of indemnities.
For the considered scheme of the external electron bunch injection in front of a laser pulse, the influence of the nonlinear driving laser pulse dynamics and electron bunch self-action to the processes of electron bunch compression and acceleration in the laser wakefield is analyzed. Self-consistent modelling results confirm that the nonlinear laser pulse dynamics limits the bunch compression due to variations of the phase velocity of the wake. A growth of the injected bunch charge leads to some extent to an increase of the trapped and accelerated bunch charge and to decrease of the trapped bunch radius and emittance due to increased self-focusing bunch. The three-dimensional theoretical model is elaborated and used to describe the propagation of laser pulses in dielectric capillary waveguides under imperfect coupling and focusing conditions with broken cylindrical symmetry. The role of cone entrances to the cylindrical part of a capillary is analyzed, and it is demonstrated that matching cones can considerably increase the transmission of laser pulses through the capillary, but cannot mitigate the requirements on the precision of the laser pulse focusing into a capillary. In order to avoid a speckle structure and strong transverse gradients of the fields, which can prevent the process of regular electron bunch acceleration, one has to ensure a small laser angle of incidence into the capillary not exceeding 1 mrad.
We give on overview of recent advances in collisionally pumped optical
field-ionization soft X-ray lasers developed at LOA. Saturated
amplification has been achieved on the 5d-5p transition in Xe8+
at 41.8 nm, and on the 4d-4p transition in Kr8+ at 32.8 nm. We
demonstrate a significant increase of the energy output from the
Xe8+ laser driven within two types of wave-guide. Finally, we
present results of a pioneering work aimed to set up and characterize the
first true soft X-ray laser chain.
The Heat Exchanger Method (HEM) of crystal growing was combined with the Fixed Abrasive Slicing Technology (FAST) to produce low-cost, high-quality sapphire substrates for deposition of the GaN family of compounds. Production quantities of 2-inch diameter blanks have been supplied, and 3-inch diameter material has been qualified. Current technology can be used to prepare sapphire blanks up to 6-inch diameter.
The influence of discrepancies between analytical expressions for charge changing cross section on the ionization state of swift heavy ions interacting with hot and dense plasmas is analyzed within the framework of our new average correlated hydrogenic atom model. Making use of our Classical Trajectory Monte-Carlo results, we show that the partial charge transfer cross section into the projectile atomic levels has the same importance as the total charge transfer cross section.
We develop a systematic comparison of thermodynamical and atomic properties computed within the three (TF, TFD, and TFDW) Thomas-Fermi modellings with results obtained from the average atom model. A special emphasis is placed on using the same analytic approximations for exchange, correlation, and gradient corrections. Analogies and discrepancies with respect to temperature behaviour are also stressed.
Sodium chlorite increased the degradability of fibre from a range of mature grass forages inoluding barley straw by 40–50 digestibility units when comparisons were made using ground (1 mm sieve) material incubated either in vitro with cellulase or in nylon bags in the rumen. However, when fed to sheep, chlorite-treated barley straw was digested to a similar degree to untreated straw (49 and 57% respectively), but intake was significantly reduced (385 and 790 g/day respectively). The poor in vivo utilization of chlorite-treated straw coincided with high proportions of propionic to acetic acid in the rumen (0·85, cf. 0·28 with untreated feed) and absence of rumen fungi. Rumen pH and ammonia concentrations were not significantly different between diets. When incubated in nylon bags in the rumen of animals fed the corresponding diet, both untreated and treated straw (< 1 mm) were well colonized with micro-organisms, as measured by cystine accumulation which showed peaks on the fibres after 24 and 72 h. While large numbers of fungal sporangia were observed after 24 h incubation on digesta from untreated forage, no fungi could be detected on the chlorite-treated material. Cystine accumulation on the untreated straw after 72 h was not associated with a secondary growth of fungi.
Although barley straw chaff, ground (< 1 mm) after treatment with chlorite, was highly degraded in nylon bags in the rumen and with cellulase in vitro, larger particles (1 cm) suspended in nylon bags in an animal fed chlorite-treated straw actually gained weight, probably due in part to the degree of microbial colonization.