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AbstractElectromagnetic and electrothermal launch devices can provide high acceleration and inject pellets with speeds in excess of 3 km/s for masses up to 3gm. However, the ablation of the bore adds impurities to the plasma. An ablation-free electrothermal pellet accelerator is a concept that utilizes an ablation-free capillary discharge in which a quartz capillary is coated with a nanocrystalline diamond film (NCD). The ablation-free capillary connects to an extension tube, which is also an ablation-free quartz tube coated with NCD that serves as the acceleration barrel. An ablation-free capillary discharge computer code has been developed to model plasma flow and acceleration of pellets for fusion fueling in magnetic fusion reactors. The code incorporates ideal and non-ideal conductivity models and has a set of governing equations for the capillary, the acceleration tube, and the pellet. The capillary generates the plasma from hydrogen/deuterium gas when the discharge current flows through the capillary. The pellet starts moving in the extension tube when the pressure of the plasma flow from the capillary reaches the release limit. The code results show an exit velocity of 2.7 km/s for a 20 mg deuterium pellet when using a capillary and barrel each 9 cm long where the source and barrel diameters are 0.4cm and 0.6cm, respectively, with a discharge current of 20 kA over a 300 both the capillary and the barrel to 12 cm increases the pellet exit velocity to 2.9 km/s, and a further increase to 18cm results in a 3.15km/s pellet exit velocity. Increasing the barrel length to 36 cm, while keeping the source length at 18 cm, results in an increase in the pellet velocity to 3.32 km/s. The pellet starts moving at 35 μs reaches 3.32 km/s in 100 this velocity until exiting the acceleration tube.

Fossils preserving traces of soft anatomy are rare in the fossil record; even rarer is evidence bearing on the size and shape of sense organs that provide us with insights into mode of life. Here, we describe unique fossil preservation of an avian brain from the Volgograd region of European Russia. The brain of this Melovatka bird is similar in shape and morphology to those of known fossil ornithurines (the lineage that includes living birds), such as the marine diving birds Hesperornisand Enaliornis, but documents a new stage in avian sensory evolution: acute nocturnal vision coupled with well-developed hearing and smell, developed by the Late Cretaceous (ca90Myr ago). This fossil also provides insights into previous ‘bird-like’ brain reconstructions for the most basal avian Archaeopteryx—reduction of olfactory lobes (sense of smell) and enlargement of the hindbrain (cerebellum) occurred subsequent to Archaeopteryxin avian evolution, closer to the ornithurine lineage that comprises living birds. The Melovatka bird also suggests that brain enlargement in early avians was not correlated with the evolution of powered flight.

Ultrananocrystalline diamond films (UNCD) grown in an Ar-rich microwave plasma with nitrogen gas added in amounts of 0–25% were studied by Raman spectroscopy using 514.5 and 413.1 nm laser excitation. Besides the Raman spectra of diamond, the first and second order Raman scattering of disordered graphite and polyacetylene were detected and analyzed for samples with different nitrogen content. With surface enhanced Raman scattering (SERS) a variety of surface vibrational modes was observed: (i) CHx stretching vibrations of sp3 and sp2 hybridized carbon in the range of 2800–3100 cm–1; (ii) the sp2 and sp1 hybridized CC(CN) stretching modes in the range of 1600–2300 cm–1; and (iii) lines in the range of 200–1250 cm–1 related to different kinds of vibrations of substituted aromatic rings. These results indicate that in N-doped UNCD films the intergrain material is a well connected mixture of predominantly sp2 phase with some amount of sp1 phase of carbon and nitrogen that is suggested to provide high electrical conductivity. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Polycrystalline diamond coatings over 100 μm thick are produced on AlN ceramic substrates by microwave-plasma CVD from a CH4-H2-O2mixture. Their Raman spectra indicate good phase purity and a compressive stress as high as about 4 GPa due to the thermal-expansion mismatch between the diamond and the ceramic. Measurements by the laser flash technique at room temperature show the coatings to have a thermal conductivity of 970 W m−1K−1as against 290 and 170 W m−1K−1for mono-and polycrystalline aluminum nitride, respectively. It is concluded that a diamond coating of appropriate thickness significantly enhances the thermal conductivity of the surface region of AlN substrates and therefore could be useful for creating more efficient AlN heat sinks.

The properties of the non-equilibrium Gliding Arc plasma were studied both experimentally and theoretically. The propagation of the plasma column was recorded continuously by using a high-speed video camera. A theoretical model was developed to determine the characteristics of the equilibrium-nonequilibrium transition. The transition is explained by the drastic change of the dominant ionization channel when the contribution of the thermal ionization to the electron density balance becomes less important than that of the direct electron impact ionization. According to our theoretical model, the majority of the Gliding Arc power (up to 75-80) can be dissipated in the cold non-equilibrium stage. Powerful non-equilibrium plasma can be generated from the initially thermal Gliding Arc discharge.

Abstract:: We associate to an arbitrary ℤ-gradation of the Lie algebra of a Lie group a system of Riccati-type first order differential equations. The particular cases under consideration are the ordinary Riccati and the matrix Riccati equations. The multidimensional extension of these equations is given. The generalisation of the associated Redheffer–Reid differential systems appears in a natural way. The connection between the Toda systems and the Riccati-type equations in lower and higher dimensions is established. Within this context the integrability problem for those equations is studied. As an illustration, some examples of the integrable multidimensional Riccati-type equations related to the maximally nonabelian Toda systems are given.

We provide a molecular description of key intermediates in the deletion of two internal eliminated sequences (IES elements), the M and R regions, during macronuclear development in Tetrahymena thermophila. Using a variety of PCR‐based methods in vivo, double‐strand breaks are detected that are generated by hydrolytic cleavage and correspond closely to the observed chromosomal junctions left behind in the macronuclei. The breaks exhibit a temporal and structural relationship to the deletion reaction that provides strong evidence that they are intermediates in the deletion pathway. Breaks in the individual strands are staggered by 4 bp, producing a four nucleotide 5′ extension. Evidence is presented that breaks do not occur simultaneously at both ends. The results are most consistent with a deletion mechanism featuring initiation by double‐strand cleavage at one end of the deleted element, followed by transesterification to generate the macronuclear junction on one DNA strand. An adenosine residue is found at all the nucleophilic 3′ ends used in the postulated transesterification step. Evidence for the transesterification step is provided by detection of a 3′ hydroxyl that would be liberated by such a step at a deletion boundary where no other DNA strand ends are detected.

In the present paper, we obtain some integrable generalizations of the continuous Toda system generated by a flat connection form taking values in higher grading subspaces of the algebra of the area-preserving diffeomorphism of the torus T2 and construct their general solutions. The grading condition we use here, imposed on the connection, can be realized in terms of holomorphic distributions on the corresponding homogeneous spaces.

A method is proposed for the classification of integrable embeddings of (2+2)-dimensional supermanifoldsV2|2 into an enveloping superspace supplied with the structure of a Lie superalgebra. The approach is first applied to the “even part” of the scheme, i.e. for the embeddings of 2-dimensional manifoldsV2 into Riemannian or non-Riemannian enveloping space. The general consideration is also illustrated by the example of superspaces supplied with the structure of the series sl(n, n+1), whose integrable supermanifolds are described by supersymmetrical 2-dimensional Toda lattice type equations. In particular, forn=1 they are described by the supersymmetrical Liouville and Sine-Gordon equations.

Reduction of a two-dimensional generalized Toda lattice to an ordinary differential equations system, which defines the functional dependence of Toda functions on the corresponding separable solutions, is given. It is shown, in particular, that between all the equations of the form ?2?/?x ?t=f(?) only Liouville (L), sine-Gordon (SG) and Bullough-Dodd (BD) equations, which are associated with simple Lie algebras of a finite growth of rank 1, lead to the third Painlevé equation (P3). The last circumstance allows one, probably, to assume the existence of a deep relation between the complete integrability condition for the corresponding class of dynamical systems and the criterion of the absence of movable critical points in the solutions of an ordinary differential equation system of the second order. If this is so, it means that Painleé's equations and transcendents can be generalized for multi-component cases.

It is shown that two-dimensionalized Volterra equations (or differenceK-dV) represent a Bäcklund transformation for a two-dimensional Toda lattice. This circumstance allows us to construct explicit solutions to Volterra equations on the basis of the known general solutions [1] of Toda lattice.

We provide a molecular description of key intermediates in the deletion of two internal eliminated sequences (IES elements), the M and R regions, during macronuclear development in Tetrahymena thermophila. Using a variety of PCR‐based methods in vivo, double‐strand breaks are detected that are generated by hydrolytic cleavage and correspond closely to the observed chromosomal junctions left behind in the macronuclei. The breaks exhibit a temporal and structural relationship to the deletion reaction that provides strong evidence that they are intermediates in the deletion pathway. Breaks in the individual strands are staggered by 4 bp, producing a four nucleotide 5′ extension. Evidence is presented that breaks do not occur simultaneously at both ends. The results are most consistent with a deletion mechanism featuring initiation by double‐strand cleavage at one end of the deleted element, followed by transesterification to generate the macronuclear junction on one DNA strand. An adenosine residue is found at all the nucleophilic 3′ ends used in the postulated transesterification step. Evidence for the transesterification step is provided by detection of a 3′ hydroxyl that would be liberated by such a step at a deletion boundary where no other DNA strand ends are detected.

Objectives. Evaluation of the immediate and long-term efficacy of a novel of transvenous closure of the patent ductus arteriosus was the purpose of this study.

In this Letter, we give an explicit integration of some two-dimensionalised Lotka-Volterra-type equations associated with simple Lie algebras possessing a representation without branching.

The integrability problem of integro-differential equations with, generally speaking, singular kernels is discussed after an example of new continual analogs of the two-dimensional Toda lattices. These equations are associated with new infinite-dimensional Lie algebras via zero curvature type representation. The structural constants of these algebras are distributions. A formal solution of the Goursát problem is obtained. For the case with the kernel of the integral operator being d±-distribution an explicit expression in quadratures for the solutions is given.

In this paper we discuss the integrability problem for a continuous Toda system, which is widely applicable in many branches of theoretical and mathematical physics and mechanics.

A supersymmetric equation associated with a continuum limit of the classical superalgebra sl(n/n+1) is constructed. This equation can be considered as a superextension of a continuous limit of t the Toda lattice with fixed end-points or, in other words, as a supersymmetric version of the heavenly equation. A solution of the Cauchy problem for the continuous limit of the Toda lattice and for its superextension is given using some formal reasonings.

A constructive proof of complete integrability of spherically symmetric self-dual equations in Euclidean spaceR4 for an arbitrary embedding of SU(2) in an arbitrary gauge groupG is given on the base of Lax-type representation and representation theory. The equations are solved explicitly for the case of simple Lie groupsG.

Expression of a neomycin phosphotransferase II (NPTII) gene has been designed to be regulated by an FLP-mediated switching of the orientation of the NPTII coding region located on the invertible DNA segment in episomal yeast plasmids. Inversion of the segment from inverted to direct orientation with respect to the promoter resulted in a dramatic increase in G418 resistance. FLP also promoted a double reciprocal exchange between the transforming and the resident 2-µm plasmid, leading to insertion of the FLP and REP2 genes into the transforming plasmid. The results demonstrate a possible use of FLP recombinase for ‘phase variation’-type regulation of gene expression and gene replacement in eukaryotic cells.

This survey is devoted to a consistent exposition of the group-algebraic methods for the integration of systems of nonlinear partial differential equations possessing a nontrivial internal symmetry algebra. Samples of exactly and completely integrable wave and evolution equations are considered in detail, including the generalized (periodic and finite nonperiodic) Toda lattice, nonlinear Schrödinger, Korteweg-de Vries, Lotka-Volterra equations, etc.). For exactly integrable systems, the general solutions of the Cauchy and Goursat problems are given in an explicit form, while for completely integrable systems an effective method for the construction of their soliton solutions is developed.

The present paper describes theW-geometry of the Abelian finite non-periodic (conformal) Toda systems associated with theB, C andD series of the simple Lie algebras endowed with the canonical gradation. The principal tool here is a generalization of the classical Plücker embedding of theA-case to the flag manifolds associated with the fundamental representations ofBn,Cn andDn, and a direct proof that the corresponding Kähler potentials satisfy the system of two-dimensional finite non-periodic (conformal) Toda equations. It is shown that theW-geometry of the type mentioned above coincide with the differential geometry of special holomorphic (W) surfaces in target spaces which are submanifolds (quadrics) ofCPN with appropriate choices ofN. In addition, theseW-surfaces are defined to satisfy quadratic holomorphic differential conditions that ensure consistency of the generalized Plücker embedding. These conditions are automatically fulfilled when Toda equations hold.

One of the main features of our information era is "digitization". In the oil industry, there is almost no easily produced oil left, so we have to constantly create the latest technologies for unconventional reserves and conduct production in hard-to-reach regions. The "digitization" of all the production components is not a tribute to fashion, but a means of maintaining efficiency and success. The principle of "toothbrush". Toothbrush monitoring is used in the extraction, refining and marketing of petroleum products by monitoring the serviceability of industrial equipment. The principle of mobility and utility. In the field of exploration and production, this means that all information about the field development is processed and, using special applications, is displayed on mobile devices of the relevant people in real time. Portable mobile devices for checking the quality of welds at the junction of pipelines directly at the place of their operation, without stopping the operation process and without damaging the inspected object, can be necessary as well. The developed device for the arc welding of magnetized products -- the IST-201 welding current inverter -- allows pipes to be welded without their preliminary demagnetization. The device allows one to weld pipes in a matter of hours, and instead of a whole group of personnel, only welders are involved. This development can scan not only finished seams or products, but also details during the manufacturing process, which allows avoiding the risk of defective products already at the production stage.

Thousands of DNA deletion events occur during macronuclear development In the ciliate Tetrahymena thermophila. In two deleted genomic regions, designated M and R, the eliminated sequences form circles that can be detected by PCR. However, the circles are not normal products of the reaction pathway. The circular forms occur at very low levels In conjugating cells, but are stable. Sequencing analysis showed that many of the circles (as many as 50% of those examined) reflected a precise deletion In the M and R regions. The remaining circles were either smaller or larger and contained varying lengths of sequences derived from the chromosomal DNA surrounding the eliminated region. The chromosomal junctions left behind after deletion were more precise, although deletions In either the M or R regions can generate any of several alternative junctions (1). Some new chromosomal junctions were detected in the present study. The results suggest that the deleted segment Is released as a linear DNA species that Is degraded rapidly. This species is only rarely converted to the stable circles we detect. The deletion mechanism is different from those proposed for deletion events in hypotrichous ciliates (2-4), and does not reflect a conservative site-specific recombination process such as that promoted by the bacterlophage λ integrase (5).