RGB generation by four-wave mixing in small-core holey fibers

We report the generation of white light comprising red, green, and blue spectral bands from a frequency-doubled fiber laser by an efficient four-wave mixing process in submicron-sized cores of microstructured holey fibers. A master-oscillator power amplifier (MOPA) source based on Yb-doped fiber is employed to generate 80 ps pulses at 1060 nm wavelength with 32 MHz repetition rate, which are then frequency-doubled in an LBO crystal to generate up to 2 W average power of green light. The green pump is then carefully launched into secondary cores of the cladding of photonic bandgap fibers. These secondary cores with diameters of about 400 to 800 nm act as highly nonlinear waveguides. At the output, we observe strong red and blue sidebands which, together with the remaining green pump light, form a visible white light source of about 360 mW. The generating process is identified as four-wave mixing where phase matching is achieved by birefringence in the secondary cores which arises from non-symmetric deformation during the fiber fabrication. Numerical models of the fiber structure and of the nonlinear processes confirm our interpretation. Finally, we discuss power scaling and limitations of the white light source due to the damage threshold of silica fibers

Medium-Energy Proton-Nucleus Elastic Scattering in the Impulse Approximation

This work was supported by National Science Foundation Grants PHY 76-84033A01, PHY 78-22774, and Indiana Universit

Structural-phase state and mechanical properties of submicrocrystalline titanium alloy Ti-6Al-4V obtained with use of reversible hydrogen alloying

Features of evolution of structural-phase state of titanium alloy Ti-6Al-4V at the process of submicrocrystalline structure formation using reversible hydrogen alloying have been investigated by methods of electron microscopic and X-ray diffraction analyses. Influence of hydrogen alloying on mechanical properties at stretching of submicrocrystalline titanium alloy Ti-6Al-4V in temperature interval of 293...1023 K was studied. Possible reasons of increase in ultimate and yield strength and reduction of deformation to destruction of submicrocrystalline alloy Ti-6Al-4V in temperature interval 873...1023 K at hydrogen alloying in quantity 0,08...0,33 mas. % were discusse

THE EFFECT OF PROTEIN SOURCE ON PARAMETERS OF RUMEN CONTENT AND DIGESTIBILITY OF NUTRIENTS IN FATTENING LAMBS

Abstract D. RuZiC-MusliCH, M. P. PetRoviCH, M. M. PetRoviCH, P. PeRisiCH, Z. BijeliCH, v. PanteliCH and v. CaRo-PetRoviCH, 2013. the effect of protein source on parameters of rumen content and digestibility of nutrients in fattening lambs. Bulg. J Agric. Sci., In this paper, results of the study of the effect of different protein sources in concentrate mixtures on fluid rumen content and digestibility of nutrients in fattening lambs are presented. Physiological study included 18 male lambs of Mis population, average body mass of approx, 35.0 kg, divided into three groups. Lambs were fed isoprotein concentrate mixtures (14% CP) which differed about protein source: sunflower meal (I), soybean meal (II) and fishmeal (III), resulting in different ratio of protein non-degradable in rumen: 43% (I), 51% (II) and 58% (iii), respectively. Content of ammonia nitrogen (nH 3 -N) in rumen fluid of fattening lambs in said treatments was 42.46: 33.86: 31.35 mg/100 ml. pH rumen value in treatments i: ii: iii were 6.56: 6.35: 6.15. Trial results show that the level of protein intake was not under significant influence of studied treatment, considering that digestibility coefficients were 52.58%: 51.30%: 55.12%. With the increase of the share of non-degradable protein in concentrate mixtures, the tendency of fat digestibility increase was observed: 76.13: 77.98: 87.17%, also of decrease of cellulose intake: 67.40: 45.87: 22.39% and nFe: 83.87: 76.05: 82.96%

Model testing of radioactive contamination Cs-137 of soils and bottom sediments in the Romachka river (Tomsk region, Russia)

This paper presents results of testing models for the radioactive contamination of river water and bottom sediments by 137Cs. The scenario for the model testing is based on data from the Romashka River, which was contaminated as a result of accidents at the Siberian Chemical Combine (Russia, Region of Tomsk). The input data include the following: estimates of inventories of 137Cs in the floodplain of the downstream part of Romashka River; the estimated annual runoff of 137Cs from the downstream part of Romachka River; data on the precipitation, hydrological and hydrochemical characteristics of the river. The endpoints of the scenario are model predictions of the activity concentrations of 137Cs in water and bottom sediments along the Romachka River in 2012-2013. Calculations for the Romashka scenario were performed by the Institute of radioprotection and nuclear safety (model CASTEAUR and HAMSTER. As a whole, the radionuclide predictions for137Cs for all considered models. At the same time the CASTEAUR model estimate the activity concentrations of 137Cs and in water more precisely than in bottom sediments

KK-metric and KK-normed linear spaces: survey

We give a short survey on some fixed point theorems which are generalizations of the classical Banach-Caccioppoli principle of contractive mappings. All these results are gathered in three theorems about existence and uniqueness of fixed points for operators which act in $K$-metric or $K$-normed linear spaces and, in particular, in local convex spaces and scales of Banach spaces. Three fixed point theorems presented in this article cover numerous applications in numerical methods, theory of integral equations, some results on iterative methods for construction of periodic solution to ordinary differential equations, existence and uniqueness results on solvability for Cauchy and Goursat problems of Ovsjannikov - Treves - Nirenberg type and so on

A single-mode, high index-contrast, lead silicate glass fibre with high nonlinearity, broadband near-zero dispersion at telecommunication wavelengths

We report on the design, fabrication and characterization of a single-mode W-type lead silicate glass fibre with flattened and near-zero dispersion profile at telecom wavelengths and high nonlinearity of 820 W-1km-1 at 1.55 µm

Influence of ion-beam treatment on structure and defor-mation resistance of 12Cr1MoV steel under static, cyclic and dynamic loading

Features of modification of structure and properties of 12Cr1MoV steel subjected to ion-beam irradiation by zirconium ion beam have been investigated with the use of optical and electron microscopy, and microhardness measurement. It was shown that after the treat-ment the modification occurs across the entire cross-section of specimens with the thickness of 1 mm. Changes in mechanical properties of these specimens under static, cyclic and impact loading were interpreted in terms of identified structure modifications

Novel spinal pathways identified by neuronal c-Fos expression after urethrogenital reflex activation in female guinea pigs

© 2014. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Pudendal nerve-spinal pathways are involved in urethrogenital sensation, pain and sexual activity. However, details of these pathways and their modulation are unclear. We examined spinal pathways activated by the urethrogenital reflex (UGR) and visualised by c-Fos immunoreactivity in reflexly activated neurons within spinal cord. In anaesthetised female guinea pigs, a balloon was inserted into the urethra and inflated with short-repeat or long-continuous distension to activate the UGR. A second balloon recorded reflex contractions of the vagina and uterus. Two control groups had either no balloon or a vaginal balloon only. Ninety minutes after UGR activation, c-Fos immunoreactivity in L3 and S2 spinal segments was examined. Reflex activated c-Fos immunoreactivity also was investigated in some animals with acute spinal transections at either L4 or T12 levels. There was no significant difference in spinal c-Fos expression between the control groups. Short-repeat distension reliably induced a UGR and a 2-3 fold increase in c-Fos-expressing neurons throughout dorsal, intermediate and lateral spinal grey matter at S2 and about two fold increase in superficial dorsal horn at L3. T12 transection had little effect on c-Fos expression at either spinal level. However, after L4 transection, UGR generation was associated with a 4-6 fold increase in c-Fos-expressing neurons in lateral horn and central canal areas at S2, and but only 20-30% increase at L3. Thus, UGR activates preganglionic neurons projecting to pelvic viscera in both sacral and lumbar spinal cord. The reflex also must activate ascending and descending spinal inhibitory circuits that suppress c-Fos-expression in neurons at both sacral and lumbar spinal levels

New evidence of the nonglaciated development of the northern part of the Western Siberian lowland in the Quaternary period

To solve the controversially debated problem related to the areal extent of the ice sheet in Western Siberia in the Quaternary period, we have studied the development of cold born objects of this area estimating the relationships between them in terms of cryogenic diversity. We have obtained a field of new cross data related to the development of cryogenic and glacial phenomena, their relationship, and traces they left. The research showed that, in this area, the trend of rock freezing is clearly reflected in the Quaternary formations, but there were no conditions for ice sheet development even during the cryochrons