Modeling of Injection Parameters for Diesel Engine Injector Nozzles with the Additional Precision Guiding Interface

AbstractPerfection of output parameters of diesel engines is considered as a result of the rail-pressure increase and modernization of nozzle tribosystems represented at high (up to 300 MPa) values of the fuel pressure. The nozzle with the modified design and additional (bottom) precision guiding interface is used and hydrodynamic parameters of injection are analyzed. The computational fluid-dynamic (CFD) modeling for estimation of hydrodynamic parameters of the fuel flow and force distribution in the “needle – nozzle body” system is used. The results of the injection modeling and contact parameters for the modified design of nozzle precision interfaces are established and discussed. The ways of increasing the stability of needle position in the nozzle body with perfection of parameters of fuel injection are presented

Combinatorics and formal geometry of the master equation

We give a general treatment of the master equation in homotopy algebras and describe the operads and formal differential geometric objects governing the corresponding algebraic structures. We show that the notion of Maurer-Cartan twisting is encoded in certain automorphisms of these universal objects

Electrical control of optical orientation of neutral and negatively charged excitons in n-type semiconductor quantum well

We report a giant electric field induced increase of spin orientation of excitons in n-type GaAs/AlGaAs quantum well. It correlates strongly with the formation of negatively charged excitons (trions) in the photoluminescence spectra. Under resonant excitation of neutral heavy-hole excitons, the polarization of excitons and trions increases dramatically with electrical injection of electrons within the narrow exciton-trion bias transition in the PL spectra, implying a polarization sensitivity of 200 % per Volt. This effect results from a very efficient trapping of neutral excitons by the quantum well interfacial fluctuations (so-called "natural" quantum dots) containing resident electrons.Comment: 18 pages, 4 figure

Coherent lidars based on intracavity heterodyning of echo signals

The development and technical realization of the method of laser sounding of the atmosphere based on the effects of mixing of reference and external fields of scattering inside a laser cavity are presented. An approximate theory of the method was developed on the basis of the investigations using the model of a three-mirror laser. The nonlinear effect of a wideband laser on frequency-dependent external influences of the atmosphere was investigated. The field measurements of gaseous composition of the atmosphere were performed on the basis of a given method of coherent reception using a tunable CO2 laser

Current issues of conformity of cements

Данная статья посвящена вопросам перехода цемента из добровольной области регулирования в область обязательного подтверждения соответствия. Однако многие производители оказались не готовы к таким изменениям. Основной причиной этого явилось ненадлежащее состояние технологической документации, требуемой в обязательном порядке для подтверждения соответствияThis article focuses on the transition of the cement from the voluntary sector management in the area of mandatory confirmation of compliance. However, many producers were not ready to such changes. The main reason for this was inadequate maintenance of technical documentation required for obligatory confirmation of complianc

Quantum Oscillations of Elastic Moduli and Softening of Phonon Modes in Metals

In this paper we present a theoretical analysis of the effect of magnetostriction on quantum oscillations of elastic constants in metals under strong magnetic fields. It is shown that at low temperatures a significant softening of some acoustic modes could occur near peaks of quantum oscillations of the electron density of states (DOS) at the Fermi surface (FS). This effect is caused by a magnetic instability of a special kind, and it can give rise to a lattice instability. We also show that the most favorable conditions for this instability to be revealed occur in metals whose Fermi surfaces include nearly cylindrical segments.Comment: 5 pages, 1 figur

Особенности гидродинамики системы «игла топливо» цилиндрического прецизионного трибосопряжения распылителя топливной форсунки дизеля

The paper considers some operational peculiar features and basic equations of hydrodynamics with reference to movement of "needle fuel" system in precision cylindrical "needle case" triboconjugation of DL-series sprayer of diesel engine fuel-injection nozzle. The paper presents methodology that makes it possible to evaluate relations between mass and geometrical parameters of elements of cylindrical triboconjugation and fuel specifications in the process of needle fit in the seat of sprayer body Рассматриваются некоторые особенности функционирования и основные уравнения гидродинамики применительно к движению системы «игла топливо» в прецизионном цилиндрическом трибосопряжении «игла корпус» распылителя серии DL топливной форсунки дизеля. Приведена методика, позволяющая оценить связи между массовыми и геометрическими параметрами элементов цилиндрического трибосопряжения и характеристиками топлива в процессе посадки иглы на седло корпуса распылителя.В верстке статьи пропущена страниц