Study of shock waves generation, hot electron production and role of parametric instabilities in an intensity regime relevant for the shock ignition

We present experimental results at intensities relevant to Shock Ignition obtained at the sub-ns Prague Asterix Laser System in 2012 . We studied shock waves produced by laser-matter interaction in presence of a pre-plasma. We used a first beam at 1ω (1315 nm) at 7 × 10 13 W/cm 2 to create a pre-plasma on the front side of the target and a second at 3ω (438 nm) at ∼ 10 16 W/cm 2 to create the shock wave. Multilayer targets composed of 25 (or 40 μm) of plastic (doped with Cl), 5 μm of Cu (for Kα diagnostics) and 20 μm of Al for shock measurement were used. We used X-ray spectroscopy of Cl to evaluate the plasma temperature, Kα imaging and spectroscopy to evaluate spatial and spectral properties of the fast electrons and a streak camera for shock breakout measurements. Parametric instabilities (Stimulated Raman Scattering, Stimulated Brillouin Scattering and Two Plasmon Decay) were studied by collecting the back scattered light and analysing its spectrum. Back scattered energy was measured with calorimeters. To evaluate the maximum pressure reached in our experiment we performed hydro simulations with CHIC and DUED codes. The maximum shock pressure generated in our experiment at the front side of the target during laser-interaction is 90 Mbar. The conversion efficiency into hot electrons was estimated to be of the order of ∼ 0.1% and their mean energy in the order ∼50 keV. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distributio

Environment influences on the aromatic character of nucleobases and amino acids

Geometric (HOMA) and magnetic (NICS) indices of aromaticity were estimated for aromatic rings of amino acids and nucleobases. Cartesian coordinates were taken directly either from PDB files deposited in public databases at the finest resolution available (≤1.5 Å), or from structures resulting from full gradient geometry optimization in a hybrid QM/MM approach. Significant environmental effects imposing alterations of HOMA values were noted for all aromatic rings analysed. Furthermore, even extra fine resolution (≤1.0 Å) is not sufficient for direct estimation of HOMA values based on Cartesian coordinates provided by PDB files. The values of mean bond errors seem to be much higher than the 0.05 Å often reported for PDB files. The use of quantum chemistry geometry optimization is strongly advised; even a simple QM/MM model comprising only the aromatic substructure within the QM region and the rest of biomolecule treated classically within the MM framework proved to be a promising means of describing aromaticity inside native environments. According to the results presented, three consequences of the interaction with the environment can be observed that induce changes in structural and magnetic indices of aromaticity. First, broad ranges of HOMA or NICS values are usually obtained for different conformations of nearest neighborhood. Next, these values and their means can differ significantly from those characterising isolated monomers. The most significant increase in aromaticities is expected for the six-membered rings of guanine, thymine and cytosine. The same trend was also noticed for all amino acids inside proteins but this effect was much smaller, reaching the highest value for the five-membered ring of tryptophan. Explicit water solutions impose similar changes on HOMA and NICS distributions. Thus, environment effects of protein, DNA and even explicit water molecules are non-negligible sources of aromaticity changes appearing in the rings of nucleobases and aromatic amino acids residues

Wplyw uwilgotnienia gleby i warunkow pogodowych na trwalosc i produkcje odmian traw pastewnych

Wyniki dotyczą czwartego roku po wysiewie, jako najbardziej typowego dla oceny przydatności gatunków i odmian traw na użytki zielone. W badaniach uwzględniono 7 odmian 4 gatunków traw. Określano wpływ rodzaju i uwilgotnienia gleby (siedlisko polowe i łąkowe) oraz warunków pogodowych (różne lata) na produkcję ich biomasy i trwałość. Stosowano dwa rodzaje użytkowania (3 i 5 pokosów) do których dostosowano nawożenie, zwłaszcza azotowe. Trwałość oraz plony większości gatunków i odmian były na ogół lepsze w siedlisku wilgotnym, a przebieg warunków pogodowych miał nie duży wpływ. W warunkach polowych prawdopodobnie ze względu na dużą kulturę gleby, zarówno trwałość jak i produkcja były największe, lecz reakcja poszczególnych gatunków i odmian była inna niż w warunkach siedlisk łąkowych.The studies were carried out in the fourth year after sowing grass. 7 varieties of 4 grass species were taken into consideration. The influence of soil wetness (meadow site - dry and wet and field site) and climatic conditions (different years) on the stability and productivity of grass were determined. Two kinds of utilization (3 and 5 cuts) were applied. The stability and yields of the grass varieties and species were better on the wet meadow sites than on the dry ones, while the best on the field site. Great influence of weather conditions was observed too

Yield structure of species and varieties of grasses depending on the first-cut date and site conditions

В трех сроках первого укоса: раннем, средне-раннем и позднем, растения срезывали на высоту 5 см и разделяли на вегетативные и ге- нерамивные побеги. К видам и сортам с большим участием генеративных побелов принадлежали ежа сборная (сорта Брудзыньска и Накельска.) и овсяница луговая (сорт Скшешовицка). Низкорослые злаки характеризовались более многочисленными вегетативными побегами. На более сухих средах образовывалось больше генеративных побегов.The plants were cut at the height of 5 cm and divided into vegetative and generative shoots in three dates of the first cut, viz.: early, medium-early and late one. To species and varieties with a high share of generative shoots belonged cocksfoot of the Brudzyńska and Nakielska varieties and meadow fescue of the Skrzeszowicka variety. Low grasses developed more vegetative shoots. On drier sites more generative shoots were formed