The directional contact distance of two ellipsoids: Coarse-grained potentials for anisotropic interactions

Copyright @ 2005 American Institute of Physics.We obtain the distance of closest approach of the surfaces of two arbitrary ellipsoids valid at any orientation and separation measured along their intercenter vector. This directional distance is derived from the elliptic contact function. The geometric meaning behind this approach is clarified. An elliptic pair potential for modeling arbitrary mixtures of elliptic particles, whether hard or soft, is proposed based on this distance. Comparisons with Gay-Berne potentials are discussed. Analytic expressions for the forces and torques acting on the elliptic particles are given.This research has been supported by GlaxoSmith-Klin

Analytic pulse design for selective population transfer in many-level quantum systems: maximizing amplitude of population oscillations

State selective preparation and manipulation of discrete-level quantum systems such as atoms, molecules or quantum dots is a the ultimate tool for many diverse fields such as laser control of chemical reactions, atom optics, high-precision metrology and quantum computing. Rabi oscillations are one of the simplest, yet potentially quite useful mechanisms for achieving such manipulation. Rabi theory establishes that in the two-level systems resonant drive leads to the periodic and complete population oscillations between the two system levels. In this paper an analytic optimization algorithm for producing Rabi-like oscillations in the general discrete many-level quantum systems is presented.Comment: Published in Phys.Rev.A. This is the final published versio

The analysis of size-segregated cloud condensation nuclei counter (CCNC) data and its implications for cloud droplet activation

Ambient aerosol, CCN (cloud condensation nuclei) and hygroscopic properties were measured with a size-segregated CCNC (cloud condensation nuclei counter) in a boreal environment of southern Finland at the SMEAR (Station for Measuring Ecosystem-Atmosphere Relations) II station. The instrumental setup operated at five levels of supersaturation <i>S</i> covering a range from 0.1–1% and measured particles with a size range of 20–300 nm; a total of 29 non-consecutive months of data are presented. The median critical diameter <i>D</i>_c ranged from 150 nm at <i>S</i> of 0.1% to 46 nm at <i>S</i> of 1.0%. The median aerosol hygroscopicity parameter &kappa; ranged from 0.41 at <i>S</i> of 0.1% to 0.14 at <i>S</i> of 1.0%, indicating that ambient aerosol in Hyytiälä is less hygroscopic than the global continental or European continental averages. It is, however, more hygroscopic than the ambient aerosol in an Amazon rainforest, a European high Alpine site or a forested mountainous site. A fairly low hygroscopicity in Hyytiälä is likely a result of a large organic fraction present in the aerosol mass comparative to other locations within Europe. A considerable difference in particle hygroscopicity was found between particles smaller and larger than ~100 nm in diameter, possibly pointing out to the effect of cloud processing increasing &kappa; of particles > 100 nm in diameter. The hygroscopicity of the smaller, ~50 nm particles did not change seasonally, whereas particles with a diameter of ~150 nm showed a decreased hygroscopicity in the summer, likely resulting from the increased VOC emissions of the surrounding boreal forest and secondary organic aerosol (SOA) formation. For the most part, no diurnal patterns of aerosol hygroscopic properties were found. Exceptions to this were the weak diurnal patterns of small, ~50 nm particles in the spring and summer, when a peak in hygroscopicity around noon was observed. No difference in CCN activation and hygroscopic properties was found on days with or without atmospheric new particle formation. During all seasons, except summer, a CCN-inactive fraction was found to be present, rendering the aerosol of 75–300 nm in diameter as internally mixed in the summer and not internally mixed for the rest of the year

Settlements of Neighboring Buildings During Piling Works

Two case histories of heavy damaging the neighbouring buildings in Sankt-Petersburg during construction the bored piles are presented. The analysis of causes of the damages has shown that ground inflow into the housing tubes due to low strength properties of water saturated liquid-plastic loams is the main cause of additional settlements of existing houses during construction the bored piles of large diameter close to them

Ментальные карты

Current paper is devoted to the mindmapping — one of the modern graphic tools of data recording and visual representation. We demonstrate its advantages in comparison with traditional (linear) way of data recording.Предлагаемая статья посвящена рассмотрению одного из современных графических инструментов визуального представления и записи информации — ментальным картам. Демонстрируются их преимущества перед традиционным (линейным) способом записи

Structures of new acidic O-specific polysaccharides of the bacterium Proteus mirabilis serogroups O26 and O30

AbstractThe polysaccharide chains of the lipopolysaccharides of the Proteus mirabilis serogroups O26 and O30 were studied using sugar and methylation analysis and 1H and 13C NMR spectroscopy, including two-dimensional correlation spectroscopy and rotating-frame NOE spectroscopy. The polysaccharides were found to be acidic due to the presence of d-galacturonic acid and its amide with l-lysine in serogroup O26 or d-glucuronic acid in serogroup O30, and the structures of their tetrasaccharide repeating units were established. The O26-specific polysaccharide is structurally and serologically related to the O-specific polysaccharide of P. mirabilis O28, which includes amides of d-GalA with l-lysine and l-serine [Radziejewska-Lebrecht, J. et al. (1995) Eur. J. Biochem. 230, 705–712]

ALGORITHM OF MULTIHARMONIC DISTURBANCE COMPENSATION IN LINEAR SYSTEMS WITH ARBITRARY DELAY: INTERNAL MODEL APPROACH

Subject of Research. The problem of multiharmonic disturbance compensation for the class of linear time-invariant plants with known parameters and delay is considered. Method. The disturbance is presented as unmeasurable output of linear autonomous model (exosystem) with known order and unknown parameters. The problem is resolved with the use of parametrized representation of disturbance designed by means of exosystem state observer and predictor of this state that finally enables applying certainty equivalence principle. In order to remove undesirable influence of delay a modified adaptation algorithm is created. The algorithm is based on augmentation of the plant state vector and generates advanced adjustable parameters for control. As distinct from widespread approaches, the proposed algorithm does not require identification of disturbance parameters and gives the possibility to remove such restrictions as adaptation gain margin and time delay margin. Main Results. Simulation results obtained in MATLAB/Simulink environment are presented to demonstrate the performance of proposed approach. Results illustrate the boundness of all signals in the closed-loop system and complete compensation of harmonic signal. It is shown that the proposed idea makes it possible to increase the adaptation gain for different delays without system stability loss. Practical Relevance. The algorithm of adaptive compensation is recommended for the use in such problems as: the problem of control for active vibration protection devices wherein several dominating harmonics can be taken from the spectrum of vibration signal; the problems of control of robotics systems with periodical behavior; the problems of ship roll compensation; the problems of space plants control in the presence of uncontrollable rotation

THE USE OF NEW REAGENT KITS FOR DETECTION AND DESCRIPTION OF ADDITIONAL ALLELES

During the screening typing of recruited volunteers with Volga Federal District for unrelated hematopoietic stem cell registry on the loci (HLA)-A, B, DRB1, DRB345 in sample No 1758 identified a new allele at locus A. The use of basic kit AlleleSEQR HLA-A Sequencing in combination with HARP – A2F98A allowed to determine the genotype of this sample – А*30:01:01, a new allele А*25, В*13, 44, DRB1*03, 09, DRB3*02, DRB4*01

Human anti-D immunoglobulin preparations: potency standardisation milestones

Human anti-D immunoglobulin preparations derived from human immune plasma are much needed and highly effective for specific anti-D prevention of perinatal complications and treatment of primary immune thrombocytopenia. The effectiveness of immune suppression is a direct function of the active ingredient dose received with the medicinal product. To improve the accuracy of anti-D antibody quantification, it is recommended to use certified reference materials with values assigned in international units (IUs). The aim of this study was to analyse the main stages in the development of the international standards (ISs) for human anti-D immunoglobulin potency testing and to substantiate the need for a national standard for anti-Rho(anti-D) antibody quantification. The article describes the creation of the first and subsequent ISs, the procedure for establishing the IU equivalent for the anti-Rho(anti-D) antibody concentration, the characteristics of the raw materials and preparations used, and the anti-Rho(anti-D) antibody assay methods applied to certify the ISs. According to the study conclusions, it is necessary to develop and certify a national standard for the content of anti-Rho(anti-D) antibodies that will meet the requirements of the corresponding Russian regulations

Cloud condensation nuclei production associated with atmospheric nucleation : a synthesis based on existing literature and new results

This paper synthesizes the available scientific information connecting atmospheric nucleation with subsequent cloud condensation nuclei (CCN) formation. We review both observations and model studies related to this topic, and discuss the potential climatic implications. We conclude that CCN production associated with atmospheric nucleation is both frequent and widespread phenomenon in many types of continental boundary layers, and probably also over a large fraction of the free troposphere. The contribution of nucleation to the global CCN budget spans a relatively large uncertainty range, which, together with our poor understanding of aerosol-cloud interactions, results in major uncertainties in the radiative forcing by atmospheric aerosols. In order to better quantify the role of atmospheric nucleation in CCN formation and Earth System behavior, more information is needed on (i) the factors controlling atmospheric CCN production and (ii) the properties of both primary and secondary CCN and their interconnections. In future investigations, more emphasis should be put on combining field measurements with regional and large-scale model studies.Peer reviewe