The massive application of chemical fertilizers to support crop production has resulted in soil, water, and air pollution at a global scale. In the same time, this situation escalated consumers’ ...concerns regarding quality and safety of food production which, due to increase of fertilizer prices, have provoked corresponding price increase of food products. It is widely accepted that the only solution is to boost exploitation of plant-beneficial microorganisms which in conditions of undisturbed soils play a key role in increasing the availability of minerals that otherwise are inaccessible to plants. This review paper is focused on the employment of microbial inoculants and their production and formulation. Special attention is given to biotechniques that are not fully exploited as tools for biofertilizer manufacturing such as microbial co-cultivation and co-immobilization. Another emerging area includes biotechnological production and combined usage of microorganisms/active natural compounds (biostimulants) such as plant extracts and exudates, compost extracts, and products like strigolactones, which improve not only plant growth and development but also plant-microbial interactions. The most important potential and novel strategies in this field are presented as well as the tendencies that will be developed in the near future.
We have remeasured the absolute 1S-2S transition frequency nu(H) in atomic hydrogen. A comparison with the result of the previous measurement performed in 1999 sets a limit of (-29+/-57) Hz for the ...drift of nu(H) with respect to the ground state hyperfine splitting nu(Cs) in 133Cs. Combining this result with the recently published optical transition frequency in 199Hg+ against nu(Cs) and a microwave 87Rb and 133Cs clock comparison, we deduce separate limits on alpha/alpha=(-0.9+/-2.9) x 10(-15) yr(-1) and the fractional time variation of the ratio of Rb and Cs nuclear magnetic moments mu(Rb)/mu(Cs) equal to (-0.5+/-1.7) x 10(-15) yr(-1). The latter provides information on the temporal behavior of the constant of strong interaction.
Over five years, we have compared the hyperfine frequencies of 133Cs and 87Rb atoms in their electronic ground state using several laser-cooled 133Cs and 87Rb atomic fountains with an accuracy of ...approximately 10(-15). These measurements set a stringent upper bound to a possible fractional time variation of the ratio between the two frequencies: d/dt ln((nu(Rb))/(nu(Cs))=(0.2+/-7.0)x 10(-16) yr(-1) (1sigma uncertainty). The same limit applies to a possible variation of the quantity (mu(Rb)/mu(Cs))alpha(-0.44), which involves the ratio of nuclear magnetic moments and the fine structure constant.
Cold atom clocks and applications
Journal of physics. B, Atomic molecular and optical physics/Journal of physics. B, Atomic, molecular and optical physics,
05/2005
Journal Article
In this paper we describe the cold atom clock PHARAO, designed for microgravity operation. All elements of the PHARAO engineering model have been manufactured and delivered to CNES, the French space ...agency. We present the clock design, its main characteristics, and initial science operation. PHARAO is one of the main components of the Atomic Clock Ensemble in Space payload that is scheduled to fly on board the International Space Station in 2010.
Experiment was conducted in 2014, 2015 and 2016 at the Institute of Field and Vegetable Crops, Novi Sad, Serbia, to study the effects of water deficit treatments during a soybean reproductive stage. ...Two water deficit treatments were conducted T1 (from beginning of blossom to seed maturation) and T2 (from beginning of seed filling to seed maturation period) and control (no water deficit). The results showed that water deficit during seed formation has a significant effect on germination energy, germination precentage and abnormal seedling. Obtained results are of great importance for farmers, because under favorable conditions, a large number of abnormal seedling has the ability to sprout, reach the reproductive stage and participate in yield formation.
This Letter reports on new experimental high dynamic range sub-sampling performances obtained from nanoscale microwave photoconductive switches operating under a 0.8 µm wavelength pulsed ...illumination. Experimental results have been performed on different samples benefiting of a low temperature grown Gallium Arsenide absorbing layer on GaAs substrate, coplanar microwave electrode profile optimisation, and the use of an ultra-low noise jitter optical source delivering optical pulses of 1 to10 ps pulse width at a 2 GHz repetition frequency at 0.8 µm optical wavelength. Thanks to carrier lifetime tunability achievement from 1 to 20 ps, in association with a carrier mobility of 3900 cm²/V.s, experimental demonstrations of 54 and 45 dB signal-to-noise ratio microwave signal sampling for signals at 5,76 and 20 GHz frequency bandwidth respectively confirms submicron devices functionality as a new class of single channel photonic analogue to digital converters.
When growing in the field, plants are exposed to the effect of heavy metals as soon as the seed comes into contact with the soil solution. Therefore, we found important to study the effect of Cd and ...Ni on maize exposed to these heavy metals since sowing. The aim of this work was to examine which anatomical changes are induced by continuous intoxication of young maize root system with 0.1 mM Cd and Ni, thus modifying its growth and capacity for water and nutrient uptake. Concomitantly, the effect on concentration and distribution of Cd, Ni and some essential ions (Ca, Mg, Zn, Fe, Cu and Mn) was studied.
In this work five different imidazolium based ionic liquids, namely: 1-(2-oxybutyl)-3-methylimidazolium chloride, C2OC2mImCl; 1-(2-oxypropyl)-3-methylimidazolium chloride, C1OC2mImCl; ...1-(3-hydroxypropyl)-3-ethylimidazolium chloride, OHC3eImCl; 1-(3-hydroxypropyl)-3-methylimidazolium chloride, OHC3mImCl; 1-(2-hydroxyethyl)-3-methylimidazolium chloride, OHC2mImCl, together with commercial 1-butyl-3-methylimidazolium chloride, bmimCl and synthesized protic imidazolium chloride, ImCl, were prepared and their toxicity examined towards wheat and barley germination and growth. Introduction of the polar groups (in the form of hydroxyde and/or ether group) in the alkyl side chain of the imidazolium cation and their influence on the reduction of the ionic liquid's toxicity is demonstrated. The results indicate that toxicity of oxygen functionalized ILs is significantly lower against wheat comparing to non-functionalized analogues. In the case of barley, influence on germination follow the same trend as in the case of wheat, but for seedlings growth different trend is observed with more pronounced toxicity of ether functionalized ILs. From these results it was also shown that alkylation in the position N-3 atom of the imidazole significantly reduces toxicity of cation.
•The influence of oxygen functionalization on the toxicity of ionic liquids towards wheat and barley was examined.•The polar groups in alkyl chain reduce toxicity of ILs.•Barley did not respond to the presence of ILs in the same way as wheat.
PDF
