Search

The condensation reactions of 5-bromoacenaphthenequinone with 2,6-diisopropylaniline and 4‑bromo-2,6-di-iso-propylaniline afford new mono- and tribromosubstituted bis(arylimino)acenaphthenes: 1,2-bis[(2,6-diisopropylphenyl)imino]-5-bromacenaphthene (Dpp-Br-Bian) (L1) and 1,2-bis[(4-bromo-2,6-diisopropylphenyl)imino]-5-bromacenaphthene (p-Br-Dpp-Br-Bian) (L2), respectively. Compounds L1 and L2 act as neutral ligands in the [(Dpp-Br-Bian)ZnCl2] (I), [(p-Br-Dpp-Br-Bian)AlCl3] (III), and [(p-Br-Dpp-Br-Bian)GaCl3] (IV) complexes synthesized by the reactions of free diimines with the corresponding metal chlorides. The reaction of the known dibromosubstituted derivative 1,2-bis[(4-bromo-2,6-di-iso-propylphenyl)iminoacenaphthene (p-Br-Dpp-Bian) (L3) with copper(I) chloride also affords complex [(p-Br-Dpp-Bian)CuCl] (II) with the neutral diimine ligand. New compounds L1, L2, and I–IV are characterized by NMR, IR spectroscopy, and elemental analysis. The molecular structure of complex I is determined by X-ray structure analysis.

We consider the problem of rational statistical control technical parameters of automatic spacecraft (AKA) in the process of their ground testing in autonomous and complex testing in a three-tier hierarchical structure: independent product testing, independent testing systems and comprehensive testing of the AKA in general. The mathematical model of control, the formalized statement of a problem and algorithm of optimization of statistical control of sets of products and their technical parameters on hierarchy of working off is given. At the same time, the model and algorithm allow you to select the optimal product range of each level of the hierarchy from the sets that are subject to mandatory control, take into account the specified requirements for technical parameters and the results of monitoring the technical parameters of the lower levels of products when planning and carrying out control of the parameters of the higher levels.

The treatment results of of 134 patients with liver abscess were studied. All patients were divided into two groups (general – 70 persons and control - 64 ones). 64 patients of control group (47.7%) were treated with traditional methods. Among 70 patients (52.3%) of general group preference was given to miniinvasive surgical interventions. Cholangiogenic abscesses were found in 30.6%, cryptogenic – 25.4%, hematogenous – 21.6%, contact 11.2%, posttraumatic – 9.0% and liver abscesses as a result of suppuration of tumor metastases – 2.2 %. Single liver suppuration occurs more often – 87,3% of cases, multiple abscesses – 12,7%. First of all, 3, 6 and 7 segments of the liver are affected – 12,9%, 26,1%, 32,0%, respectively. In control group, the operation of liver abscess drainage via laparotomy was performed in 56 cases (87.5% of 64 patients) versus 22 (31.4% of 70 patients) in general group. Percutaneous drainage of abscesses – 8 (12.5%) and 42 (60%) respectively. Laparoscopic operations (6 or 8,6%) took place only in general group, and included external percutaneous drainage in 3 cases, fenestration – in 2, puncture-aspiration sanitation – in 1. Consequently, in general group miniinvasive surgical approaches for drainage of liver abscesses were applied in the majority of patients - 48 (68.6%) ones versus 8 (12.5%) in control group. The using of miniinvasive surgical drainage techniques for liver abscesses showed a significant decrease (p

The analysis of the main directions of development of automatic spacecraft (AKA), the organization and features of the ground testing of their systems, as well as the main methods of statistical control of their reliability is carried out. The General characteristic of AKA as the object of research is given, the main directions of improvement of the existing methods of statistical control of reliability of AKA and the systems entering into it at their ground working off are defined.

The article considers the problem of determining the rational plans of the input sampling reliability and technical parameters of components of space technology, the totality of which is supplied to the Assembly plants for the manufacture of complex products of space technology. Problem statement and mathematical model based on the minimization of the economic costs of control and losses related to the risks of taking wrong decisions, are given in the article. The properties of the mathematical models are investigated, the algorithm for its optimization is developed. The result is an optimal plan for the sampling of sets of components, which includes: an optimal product mix subject to mandatory control of the aggregate and optimum risks of first and second kind, when acceptance number of statistical plan is zero. The latter circumstance is due to the high requirements of reliability and technical parameters of products of space technology.

A procedure is described for the synthesis of lactide by dehydration of L-lactic acid and subsequent depolymerization of its oligomer mixture in the presence of yttrium(III) and praseodymium(III) oxides, as well as of cerium(III) chloride heptahydrate. The catalytic activity of yttrium and praseodymium sesquioxides was determined at different temperatures at the oligomerization and deoligomerization stages. Ethyl lactate was prepared in the presence of Purolite C100 MB cation exchange resin and subjected to oligomerization followed by thermal decomposition of oligoester and oligolactic acid mixture in the presence of yttrium(III) and praseodymium(III) oxides and aqueous cerium(III) chloride.

Reduction of digallane (dpp-bian)Ga—Ga(dpp-bian) (1) (dpp-bian is the 1,2-bis[(2,6-di-isopropylphenyl)imino]acenaphthene dianion) with metallic sodium in THF leads to the formation of gallylsodium (dpp-bian)Ga—Na(thf)4 (2). Reduction of digallane 1 with dicyclopentadienyltetracarbonyldiiron, vanadocene, and nickelocene furnishes the corresponding gallyl complexes (dpp-bian)Ga—FeCp(CO)2 (3), (dpp-bian)Ga—VCp2 (4) and [(dpp-bian)Ga]2NiCp (5). The reaction of 1 with Cp2Mn gives a gallium-free complex (dpp-bian)MnCp(dme) (6). Carbonylates [{(dpp-bian)Ga—M(CO)5}{Na(thf)2}]2 (M = Cr (7), W (8)) and [{(dppbian)Ga}2FeCp(CO)][Na(dme)3] (9) were obtained by the reaction of carbonyls Cr(CO)6, W(CO)6, and [CpFe(CO)2]2 with compound 2. Diamagnetic derivatives 3, 7, 8, and 9 were characterized by 1H NMR spectra. The structures of products 3—9 were established by single crystal X-ray diffraction.

Reactions of (2,6-diisopropylphenylimino)acenaphthenone (dpp-mian) with gallium(III), antimony(III), titanium(IV), and cobalt(II) chlorides in toluene lead to the formation of compounds of the formulas [(dpp-mian)2GaCl2][GaCl4], (dpp-mian)SbCl3, (dpp-mian)TiCl4, and [(dpp-mian)CoCl2]2[CoCl2(EtOH)4], respectively. The complexes were characterized by IR and NMR spectra, their structure was established by X-ray crystallography.

Phenylethynyl cuprate complexes of lanthanides react with organyl halides RX, Ph3CX, R3SiX, and RC(O)X (X = Cl, I; R = alkyl) in tetrahydrofuran to give polyfunctional organic and hetero-organic compounds with high yield. The reaction mechanism is discussed.

The reaction of Cr(CO)6 with 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (1, dppbian) affords a chromium complex with the neutral diimine ligand (dpp-bian)Cr(CO)4 (2). The exchange reactions of the compound [(dpp-bian)Cr(μ-Cl)(THF)]2 (3) with LiOH, PhC≡CNa, [(CH3)3Si]2NK, C5H5Na, and C5Me5Na give the corresponding radical-anion derivatives, viz., [(dpp-bian)Cr(μ-OH)]2 (4), [(dpp-bian)Cr(μ-C≡CPh)]2 (5), (dpp-bian)Cr[N(SiMe3)2]-(THF) (6), (dpp-bian)Cr(C5H5) (7), and (dpp-bian)Cr(C5Me5) (8). The titanium and zirconium complexes with the acenaphthene-1,2-diimine dianion, viz., (dpp-bian)2Ti (9) and (dpp-bian)Zr(Cl)Cp (10), were synthesized by the reactions of Na2(dpp-bian) with TiCl4 and CpZrCl3, respectively. All compounds were characterized by IR spectroscopy and elemental analysis. Diamagnetic derivatives 2, 9, and 10 were additionally studied by 1H NMR spectroscopy. The structures of products 2, 4–8, and 10 were determined by X-ray diffraction.

A gallium(I) carbenoid derived from redox-active diimine 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (dpp-bian) in complexes with molybdenum may serve either as a neutral [(dpp-bian)Ga:] or an anionic [(dpp-bian)Ga:](-) two-electron donor depending on the electronic state of the transition metal.

The reactions of iron diiodide with one and two equivalents of the monopotassium salt of 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (dpp-BIAN) in diethyl ether gave the complexes [(dpp-BIAN)FeI]2 (1) and (dpp-BIAN)2Fe (2), respectively. The bis-ligand complex (tms-BIAN)2Fe (3) was synthesized by the exchange reaction of the monosodium salt of 1,2-bis(trimethylsilylimino)acenaphthene (tms-BIAN) with iron diiodide. The reaction of FeI2 with tms-BIAN affords the chelate complex (tms-BIAN)FeI2 (4), whereas the reaction of FeBr2·2H2O with tms-BIAN is accompanied by elimination of trimethylsilyl groups to form the tris-ligand acenaphthene-1,2-diimine complex [(H2BIAN)3Fe][FeBr3·THF]2 (5) containing two types of iron ions. Compounds 1–5 were characterized by IR spectroscopy and elemental analysis. The molecular structures of 1–5 were determined by single-crystal X-ray diffraction. For high-spin complexes 1–3, the temperature-dependent magnetic susceptibilities were measured in the range of 4–300 K.

The article describes the experience of treatment of 66 patients with liver abscess. 38 patients were operated using a traditional open method. 28 – minimally invasive technologies under control of ultrasonography. The majority of liver abscess of the right share was localized in 7 th and 8 th segments, the left share – 3d and 4 th . The volume of liquid formations ranged from 1-2 ml to 1.2 l. The liver abscess was, as a rule, secondary. The use of minimally invasive technologies is an effective method of treatment of liver abscess, it allows to significantly reduce the frequency of complications, duration of hospitalization and a quality of patient’s life. Lethal cases were not recorded.

The possibility of using interdigital transducers (IDTs) and reflecting lattices with electrode period modulation (dispersion) in resonator filters with longitudinal acoustic coupling on surface acoustic waves is considered. The experimental investigation of test structures with different directivities of the transducer dispersion shows that dispersive IDTs provide for unidirectional excitation. A model developed on the basis of the equivalent-circuit method makes it possible to calculate the characteristics of filters of the class under consideration. It is found that the use of dispersive IDTs and reflecting lattices makes it possible to reduce the insertion losses of devices, to extend their passbands, and to improve their selectivity. A set of filters is designed on the basis of lithium tantalate and lithium niobate acoustic ducts with insertion loss ranging from 1.5 to 3.0 dB and relative passbands ranging from 1 to 8%.

The reactions of (dpp-BIAN)Mg(THF)3 (1) {dpp-BIAN = 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene} with ethyl halides EtX (X = Cl, Br, I) in hexane proceed by single-electron transfer (SET) from the metal complex to the organic halide. Complexes [(dpp-BIAN)(Et)]MgX(THF)n [X = Cl, n = 0 (2); X = Br, n = 2 (3); X = I, n = 1 (4)] are the products of ethyl transfer to an imine carbon atom of a coordinated diimine ligand. The compound [(dpp-BIAN)(Et)]MgBr (3a) was obtained from the reaction of free dpp-BIAN with ethylmagnesiumbromide in hexane. In this case SET from the Grignard reagent to the neutral diimine takes place. Compounds 2–4 and 3a were isolated as crystals and characterized by 1H NMR spectroscopy. The molecular structure of 3 was determined by single-crystal X-ray analysis. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

Results of implementing any pricing policy in the Russian power industry have a direct effect on the economic effectiveness of all sectors of the national economy due to the use of electric power for any activity or manufacture of any product. Intersectoral relations existing in the economy intensify and multiply the influence of the price factor in the power industry: price changes have an impact on the expenses of sectors both directly and indirectly. For example, the purchase cost of raw materials produced by energy-intensive sectors greatly influences the manufacturing cost of their own products. Since the amount of the gross domestic product (GDP) (the constituents of which are salary fund, taxes, the gross profit of sectors of the national economy) is an integral indicator of economic activities of the national economy, this article analyzes the influence of the pricing policy in the power industry on the basic national GDP indicators and represents solutions to two most critical issues in the Russian power industry: when marginal electricity prices decrease in the day-ahead market of the wholesale electricity and capacity market after returning to the governmental regulation of electricity rates of nuclear and hydraulic power plants, and when the cross-subsidization system in the Russian power industry is liquidated.

The results of investigations performed at the conceptual design stage of the development of rod-shaped fuel elements based on spherical plutonium dioxide particles with protective coatings (fuel microelements) for a modular HTGR (GT-MGR type) with a gas turbine are presented.

An air jet buried in liquid molten cast iron is called a "strong" jet in metallurgy [1]. We used this term in the continuous one-stage method of obtaining melts of alkali metal nitrates or hydroxides from solutions, as proposed in [2, 3]. The internal-mixing air-spray burner [4] used in spraying in combustion of liquid fuel and drying of solutions is used to form a "strong" jet (jet of air with an aqueous solution of a nitrate or hydroxide sprayed in it in the form of drops). In the given case (Fig. 1), the solution is fed in internal channel 2 of the injector with a rate of w w = 0.5-1 m/sec under pressure, and air is fed in outer channel I with a rate of w I = 20-30 m/sec. When these streams enter mixing chamber 3, the solution is broken up into drops due to the large difference in their velocities and a gas-liquid mixture is formed, which flows out into the superheated melt of alkali metal nitrate (or hydroxide) at rate w m from the bottom up. The temperature of the melt is kept constant by heat from an electric heater. The parameters of the technological stability of the process were established in the experiments in [3] with sodium nitrate melt at a constant temperature of 623 K and feed of an air-water jet with a temperature of 298 K: superheating temperature of 50~ specific consumption of air for spraying no less than 0.315 kg/kg (concentration of air in the jet was no more than 0.76 kg H20/kg of the mixture). The "technological stability" of the process means the absence of jolts and collisions in the apparatus, i.e., quiet bubbling of the vapor-air mixture through the melt, identified by the absence of pulsations in the flow rates and pressures of the medium in front of the injector, and the temperature on the boundary of the heat and mass exchange zone in the melt [3]; the absence of crystallization of the melt in its bulk, monitored by nonclosure of the output nozzle of the injector. In conducting more than 200 experiments on injectors with an output nozzle with diameter d equal to 1.5, 2.1, 2.55, 3, and 3.5 mm and consumption of the air-water mixture G m from 6 to 20 kg/h for the concentration of water in the mixture gm from 5.6 to 0.9 kg/kg, the following was established. In feeding air alone, pressure pl and corresponding air flow Gg are established in the injector. The flow rate was measured with a glass rotameter and calculated with the equation for adiabatic flow of gases [5] which has the following form for an adiabatic curve index for air equal to 1.4

Membrane technology for diffusion separation of gas mixtures is the most suitable process used to generate ultra pure hydrogen (UPH). The development of large-scale production of UPH is inhibited for lack of commercial membrane materials. The principles of creation of new effective membrane palladium alloys, which are founded on investigations of physical, mechanical, technological properties, hydrogen permeability and resistance to thermocycling, are reviewed in this paper.

Rosatom of the Russian Federation and the U.S. National Nuclear Security Administration are developing the Gas-Turbine Modular Helium Reactor (GT-MHR) for the disposition of weapons-grade plutonium. Cost effective disposition of this plutonium material can be achieved by use of very high burnup coated particle fuel in the GT-MHR. In this way essentially all of the valuable energy of the Pu can be efficiently converted to electricity in one pass of the fuel through the GT-MHR.Copyright © 2008 by ASME

RSPUDT filters based on different width split fingers for IF applications have been developed. Such filters provide improvement of insertion loss comparing to DART-RSPUDT filters. A new optimization procedure for RSPUDT filter design has been proposed based on the adjustment of RSPUDT through a synthesis grid of narrow structure elements. The width of these elements is equal to or smaller than a minimal finger width of a basic SPUDT structure. This approach provides additional improvement of filter characteristics. DWSF-RSPUDT filters on quartz and 112/spl deg/-LiTaO/sub 3/ are reported. Relative bandwidths of these filters are 1-3% and out-of-band rejection about 40 dB. Insertion loss is 1-3 dB better than that for equivalent filters based on other RSPUDT structures.

The possibility of utilizing cuts of LiNbO/sub 3/ with high piezoelectric coupling for leaky waves-41/spl deg/-YX and 49/spl deg/-YX-in wideband SAW filters, has been demonstrated. The equivalent circuit model was modified for longitudinally coupled resonator filters and some second-order effects have been taken into account to improve the accuracy of filter simulation. Thick Al electrodes are used to increase the effective electromechanical coupling. Spurious SAW signals are suppressed by the frequency shift between filter cascades. Low-loss (2-3 dB) two-cascade filters with bandwidths 6-7% and high sidelobe suppression (60 dB), more typical for three-cascade filters, were designed and manufactured.

The new SPUDT structures based on triple electrode sections (TES) per wavelength with the period between SAW sources about n/spl lambda//3 are presented. The simulation technique which accounts for second order effects has been developed within the framework of modified equivalent circuit model. The SPUDT structures have been implemented in filters with 0.1-3.2% bandwidths fabricated on quartz and LiTaO/sub 3/ substrates. The results of simulation have been verified experimentally and show that insertion loss of TES SPUDT filters is less by 1.0-1.5 dB than that in conventional SPUDT filters. The impedance frequency dependence becomes more symmetrical and the passband distortions are reduced. Stopband rejection is 50-60 dB.

Transversal filters with very high shape factor have been developed based on multiharmonic and withdrawal weighted transducers with isolated sections. The developed simulation technique provides excellent results both for in-line filter structures and those with multistrip couplers. The experimental results are presented for IF filters manufactured on YZ-LiNbO/sub 3/ and ST-quartz substrates. In-line filters exhibit SF in the range 1.15-1.2 and for MSC filters, SF values 1.05-1.1 have been obtained. For all filters the stopband rejection is more than 50 dB.

This paper describes SAW filters based on quasi-slanted transducers. Stepped electrodes structures used for such filters realization provide decreasing of filter shape factor and simplify their performance. Experimental results of the filters with relative bandwidths from 2% to 70% are represented.

Due to good temperature stability and moderately high electromechanical coupling coefficient langasite (Li3Ga5SiO4 or LGS) is known as a promising material for SAW devices. The characteristics of the Rayleigh wave propagation on LGS have been studied fairly well. However, no design of SAW devices on LGS suitable for modern communication systems has been reported as yet. In this paper, transversal filters on LGS based on bidirectional interdigital transducers, and low-loss filters on LGS based on natural single phase unidirectional transducers (NSPUDT), are described. The filters on LGS have exhibited better electrical parameters than their analogues on quartz and lithium tantalate.

Significant increase in the rate of applying for emergency medical care has been been established on days on which high atmospheric air pollution levels are recorded as compared with more "clean" days in the city with its large works of ferrous metallurgy, by-product coke industry and construction industry (civil engineering), the above fact being accounted for by compromised state of the respiratory system in children between the ages of 3 to 7 years.