Synthesis and crystal structure of nickel(II) complex based on 2-trifluoroacetylcycloalkanone benzoylhydrazones

The reaction of ethanol solutions of benzoylhydrazones of 2-trifluoroacetylcycloalkanones (H₂L) with a solution of nickel(II) acetate in aqueous ammonia in 1 : 1 ratio gave complexes NiL · NH₃ with square structure. The composition and structure of the complexes were determined by elemental analysis, IR and 1H NMR spectroscopy, and X-ray diffraction analysis.     

A method for constructing asymptotic expansions of bisingularly perturbed problems

In this paper we propose an analog of the method of boundary functions for constructing uniform asymptotic expansions of solutions to bisingularly perturbed problems. With the help of this method we construct uniform asymptotic expansions of solutions to the Dirichlet problem for bisingularly perturbed ordinary differential equations and elliptic equations of the second order. By the use of the maximum principle we obtain estimates for the remainder terms.     

Copper(II) complexes based on 2-thenoyltrifluoroacetone aroyl hydrazones: Synthesis,spectroscopy, and X-ray diffraction analysis

Copper(II) complexes CuL ? NH₃ are synthesized by the interaction of ethanol solutions of parasubstituted 2-thenoyltrifluoroacetylmethane aroyl hydrazones (H₂L¹–H₂L⁴) and an aqueous-ammonia solution of copper(II) acetate in an equimolar ratio. The copper(II) complexes are studied by elemental analysis, IR spectroscopy, and EPR spectroscopy. Single crystals of CuL³ ? NH₃ are grown from 1-(2-thenoyl)- 3,3,3-trifluoroacetone para-methylbenzoyl hydrazone and studied using X-ray diffraction analysis (CIF file CCDC 1045841).     

Constraints on Mass,Spin and Magnetic Field of Microquasar H 1743-322 from Observations of QPOs

The study of quasi-periodic oscillations (QPOs) of X-ray flux observed in many microquasars can provide a powerful tool for testing of the phenomena occurring in strong gravity regime. QPOs phenomena can be well related to the oscillations of charged particles in accretion disks orbiting Kerr black holes immersed in external large-scalemagnetic fields. In the present paper we study the model ofmagnetic relativistic precession and provide estimations of the mass and spin of the central object of the microquasar H 1743-322 which is a candidate for a black hole. Moreover, we discuss the possible values of external magnetic field and study its influence on the motion of charged particles around rotating black hole.     

A study of Rydberg np states of Cd I and the determination of cadmium evaporation heat

The np ³ P _{0, 1, 2} states of Cd I in the range n=15–60 were studied by three-stage laser excitation and electric-field ionization for the measurement of kinetics of cadmium evaporation. The saturated vapor pressure and the evaporation heat of cadmium in a temperature range of 300–535 K were determined.     

Bone Grafts and Substitutes in Dentistry: A Review of Current Trends and Developments

After tooth loss, bone resorption is irreversible, leaving the area without adequate bone volume for successful implant treatment. Bone grafting is the only solution to reverse dental bone loss and is a well-accepted procedure required in one in every four dental implants. Research and development in materials, design and fabrication technologies have expanded over the years to achieve successful and long-lasting dental implants for tooth substitution. This review will critically present the various dental bone graft and substitute materials that have been used to achieve a successful dental implant. The article also reviews the properties of dental bone grafts and various dental bone substitutes that have been studied or are currently available commercially. The various classifications of bone grafts and substitutes, including natural and synthetic materials, are critically presented, and available commercial products in each category are discussed. Different bone substitute materials, including metals, ceramics, polymers, or their combinations, and their chemical, physical, and biocompatibility properties are explored. Limitations of the available materials are presented, and areas which require further research and development are highlighted. Tissue engineering hybrid constructions with enhanced bone regeneration ability, such as cell-based or growth factor-based bone substitutes, are discussed as an emerging area of development.     

On the estimation of the asymptotic variance of the rank estimators for the location parameter from a sample of random size

We obtain conditions for asymptotic normality of the estimate of asymptotic variance of rank estimators for the location parameter. The size of the sample is assumed ro be random and to depend on the sample values. We consider applications of the result obtained to sequential estimation of confidence intervals.Translated fromTeoriya Sluchainykh Protsessov, Vol. 15, pp. 97–102, 1987.     

A laser photoionization method for the study of the CdS evaporation kinetics

The evaporation rates and saturation vapor pressures of cadmium sulfide and pure metallic cadmium are measured in the temperature ranges 585–950 K and 350–535 K, respectively, using laser resonance multistep photoionization. It is shown that CdS thermally dissociates into Cd atoms and S₂ molecules. The study is carried out in the framework of a scheme proposed earlier for photoionization of cadmium atoms. The measured minimum vapor pressure of pure cadmium is 10^?11 Torr.     

Multiplicities in84Kr interactions in emulsion at 800–950 MeV/nucleon

Inelastic interactions induced by⁸⁴Kr nuclei at 800–950 MeV/nucleon have been studied using a high angular resolution emulsion detector. Data on multiplicities of the produced particles, projectile and target fragments are shown. Comparisons with cascade calculations have been performed.We thank to Swedish Research Council for Natural Sciences for the financial support. Scanning and measurements performed by E.G. Broomé and V. Kopljar are acknowledged.