Оценка шума взаимодействия в осевых компрессорах и вентиляторах

Equations for discrete noise approximation of axial compressor and centrifugal fans depending upon number of geometrical and operating parameters are obtained.Получены уравнения для оценки шума взаимодействия в осевых компрессорах и вентиляторах в зависимости от ряда геометрических и режимных параметров

Influence of Carbon Fibers on Structure and Properties of Polytetrafluoroethylene

In this paper, we studied the effect of carbon fibers on the performance properties of polymer composites based on polytetrafluoroethylene. It was shown that the introduction of PTFE carbon fibers significantly improved tribological and mechanical properties of the composite. The correlation between the performance properties and supramolecular structure was found. Initial lamellar structure of the polymer became less in size without significant changes in morphology when filled. Such process was accompanied by the increase of crystalline regions number and the crystallinity degree of composite. Structural studies have shown that materials with more densely packed and highly crystalline structure have increased mechanical and tribological properties. The developed materials can be used in friction units of machines and devices, where the use of lubricants is not acceptable or restricted

Профиль лопатки турбины из кривых Bezier

An article presents profiling turbine blades The computer program in Mathcad is an element of CAD design system turbine. Blade profile outlines three curves Bezier: (back profile — one parabola (Bezier curve of order 2); trough — two parabolas (Bezier curves of order 2). In the construction was given the maximum thickness of the profile.В работе рассмотрен вопрос профилирования лопатки турбины. Профиль лопаток очерчивается тремя кривыми Bezier: спинка профиля — одной параболой (кривой Bezier 2-го прядка, корытце — двумя параболами (кривыми Bezier 2-го порядка) с заданием максимальной толщины профиля

Исследование уровня шума центробежных нагнетателей и их трубопроводов обвязки на компрессорных станциях

The questions on how to reduce noise centrifugal compressors and pipelines piping at compressor stations.В статье рассмотрены вопросы о путях снижения уровня шума центробежных нагнетателей и их трубопроводов обвязки на компрессорных станциях

Adjuvant Formulations Designed to Improve Swine Vaccine Stability: Application to PCV2 Vaccines

AbstractPorcine circovirus associated diseases (PCVADs) are economically important diseases of domestic pigs caused by porcine circovirus type 2 (PCV2). PCV2 vaccination is usually performed with adjuvanted inactivated formulations and is necessary to control PCVADs and subclinical PCV2 related body weight losses in pig farming. An important issue with PCV2 vaccine formulation is that PCV2 antigenic media often have properties which destabilize vaccine formulations. Vaccine adjuvants are a key parameter in modern vaccination closely linked to galenic properties of vaccine formulations, and galenic stability is necessary to insure efficacy stability during vaccine shelf life. Here we show that especially designed formulations based on MontanideTM ISA 11R VG (Oil in water) and MontanideTM ESSAI Gel R (polymer) adjuvants are able to resist to very destabilizing antigenic media and conditions while keeping safety parameters and efficacy at requested levels

Spectral extension of the quantum group cotangent bundle

The structure of a cotangent bundle is investigated for quantum linear groups GLq(n) and SLq(n). Using a q-version of the Cayley-Hamilton theorem we construct an extension of the algebra of differential operators on SLq(n) (otherwise called the Heisenberg double) by spectral values of the matrix of right invariant vector fields. We consider two applications for the spectral extension. First, we describe the extended Heisenberg double in terms of a new set of generators -- the Weyl partners of the spectral variables. Calculating defining relations in terms of these generators allows us to derive SLq(n) type dynamical R-matrices in a surprisingly simple way. Second, we calculate an evolution operator for the model of q-deformed isotropic top introduced by A.Alekseev and L.Faddeev. The evolution operator is not uniquely defined and we present two possible expressions for it. The first one is a Riemann theta function in the spectral variables. The second one is an almost free motion evolution operator in terms of logarithms of the spectral variables. Relation between the two operators is given by a modular functional equation for Riemann theta function.Comment: 38 pages, no figure

Perturbative dynamics of fuzzy spheres at large N

We clarify some peculiar aspects of the perturbative expansion around a classical fuzzy-sphere solution in matrix models with a cubic term. While the effective action in the large-N limit is saturated at the one-loop level, we find that the ``one-loop dominance'' does not hold for generic observables due to one-particle reducible diagrams. However, we may exploit the one-loop dominance for the effective action and obtain various observables to all orders from one-loop calculation by simply shifting the center of expansion to the ``quantum solution'', which extremizes the effective action. We confirm the validity of this method by comparison with the direct two-loop calculation and with Monte Carlo results in the 3d Yang-Mills-Chern-Simons matrix model. From the all order result we find that the perturbative expansion has a finite radius of convergence.Comment: 21 pages, 9 figures, (v2) all order analyses added, (v3) some typos correcte

Discrete diffusion in multistage mixing of dough with anisotropic internal structure

Dough making is a very critical stage of bread baking, largely, due to complex processes taking place thereupon. Key issues, undoubtedly, include a uniform distribution of liquid components over a generally anisotropic structure of the dough. Most solutions to the problem of uniform distribution of non-Newtonian liquids – protein-fat components of the dough, are based on the idea that the internal structure of particles is isotropic. However, it is not true in all cases. Some researchers have proved that distribution of fat components of different layers varies while the matter is being formed. A reason for it is a certain orientation and denser packing of protein molecules in the layers closer to kneading blades, which, naturally, means that the internal structure of different layers varies, too

The Fuzzy Sphere: From The Uncertainty Relation To The Stereographic Projection

On the fuzzy sphere, no state saturates simultaneously all the Heisenberg uncertainties. We propose a weaker uncertainty for which this holds. The family of states so obtained is physically motivated because it encodes information about positions in this fuzzy context. In particular, these states realize in a natural way a deformation of the stereographic projection. Surprisingly, in the large $j$ limit, they reproduce some properties of the ordinary coherent states on the non commutative plane.Comment: 18 pages, Latex. Minor changes in notations. Version to appear in JHE

Small-angle fragmentation of carbon ions at 0.6 GeV/n: a comparison with models of ion-ion interactions

Momentum distributions of hydrogen and helium isotopes from 12C fragmentation at 3.5° were measured at 0.6 GeV/nucleon in the FRAGM experiment at ITEP TWA heavy ion accelerator. The fragments were selected by correlated time of flight and dE/dx measurements with a magnetic spectrometer with scintillation counters. The main attention was drawn to the high momentum region where the fragment velocity exceeds the velocity of the projectile nucleus. The momentum spectra of fragments span the region of the fragmentation peak as well as the cumulative region. The differential cross sections cover six orders of magnitude. The distributions measured are compared to the predictions of three ion-ion interaction models: BC, QMD and LAQGSM03.03. The kinetic energy spectra of fragments in the projectile rest frame have an exponential shape with two temperatures, being defined by their slope parameters