Precision of spiral-bevel gears

The kinematic errors in spiral bevel gear trains caused by the generation of nonconjugate surfaces, by axial displacements of the gears during assembly, and by eccentricity of the assembled gears were determined. One mathematical model corresponds to the motion of the contact ellipse across the tooth surface, (geometry I) and the other along the tooth surface (geometry II). The following results were obtained: (1) kinematic errors induced by errors of manufacture may be minimized by applying special machine settings, the original error may be reduced by order of magnitude, the procedure is most effective for geometry 2 gears, (2) when trying to adjust the bearing contact pattern between the gear teeth for geometry 1 gears, it is more desirable to shim the gear axially; for geometry II gears, shim the pinion axially; (3) the kinematic accuracy of spiral bevel drives are most sensitive to eccentricities of the gear and less sensitive to eccentricities of the pinion. The precision of mounting accuracy and manufacture are most crucial for the gear, and less so for the pinion

Kinematic precision of gear trains

Kinematic precision is affected by errors which are the result of either intentional adjustments or accidental defects in manufacturing and assembly of gear trains. A method for the determination of kinematic precision of gear trains is described. The method is based on the exact kinematic relations for the contact point motions of the gear tooth surfaces under the influence of errors. An approximate method is also explained. Example applications of the general approximate methods are demonstrated for gear trains consisting of involute (spur and helical) gears, circular arc (Wildhaber-Novikov) gears, and spiral bevel gears. Gear noise measurements from a helicopter transmission are presented and discussed with relation to the kinematic precision theory

Historical and cultural heritage as a factor for the tourist development of a city

The article considers the influence of historical and cultural heritage preservation on the development of the tourist potential of Kazan. Today, the protection of cultural heritage is one of the state priorities. The Republic of Tatarstan is distinguished by a rich cultural heritage. Multicultural and multi-confessional nature are present on this land traditionally. The capital of the republic - the city of Kazan - is visited annually by millions of tourists. The authors pay a special attention to the most visited tourist sites of the city: the museum-reserve "Kazan Kremlin", the Old-Tatar Sloboda, the Kazan Bogoroditsky Monastery and the historical center. In recent years, full-scale works have been carried out in the field of cultural heritage preservation, in particular on designated sites, whose results are now witnessed by the residents and the tourists of Kazan. In order to popularize the cultural heritage and attract the tourists to the city, Kazan museums conduct an active exhibition, methodical, publishing and other activities. All necessary infrastructure for the reception of tourists is created in the historical center of the city: hotels, food and specialized trade places. The cultural heritage of the city and modern tourist realities do not contradict, but complement each other harmoniously.peer-reviewe

Hadronic Production of the Doubly Charmed Baryon Ξcc\Xi_{cc} with Intrinsic Charm

The effects of the intrinsic charm on the hadronic production of $\Xi_{cc}$ are studied. By taking reasonable intrinsic charm component into account, the change of the theoretical prediction on the production of $\Xi_{cc}$ for LHC and Tevatron is small, but in contrast it may enhance significantly for SELEX. The reason is that the collision energy at LHC and Tevatron is so large that the gluon-gluon fusion sub-process, which is irrelevant to intrinsic charm, becomes dominant. But the situation for SELEX is quite different. Our numerical results for SELEX show that by considering all the contributions from various sub-processes, the predicted cross-section may be enhanced by a factor so big as $10^2$ due to a modulating intrinsic charm being taken into account. Therefore, the hadronic production of $\Xi_{cc}$ at SELEX may be sensitive enough in observing the intrinsic charm inside the incident hadrons.Comment: 18 pages, 8 figures. More discussions are adde

Installation for service passenger cars brake system

Рассмотрена важность тормозной системы, а именно тормозных жидкостей для легковых автомобилей, предоставлена установка с помощью которой заправляют, прокачивают тормозную систему автомобилей, для облегчения работы на станциях технического обслуживания.Considered the importance of the braking system, namely, brake fluids for passenger cars, provided installation through which run the show pumped brake systems, to facilitate the work at service stations

Transverse magnetic routing of light emission in hybrid plasmonic-semiconductor nanostructures: Towards operation at room temperature

We study experimentally and theoretically the temperature dependence of transverse magnetic routing of light emission from hybrid plasmonic-semiconductor quantum well structures where the exciton emission from the quantum well is routed into surface plasmon polaritons propagating along a nearby semiconductor-metal interface. In II-VI and III-V direct band semiconductors the magnitude of routing is governed by the circular polarization of exciton optical transitions, that is induced by a magnetic field. For structures comprising a (Cd,Mn)Te/(Cd,Mg)Te diluted magnetic semiconductor quantum well we observe a strong directionality of the emission up to 15% at low temperature of 20 K and magnetic field of 485 mT due to giant Zeeman splitting of holes mediated via the strong exchange interaction with Mn$^{2+}$ ions. For increasing temperatures towards room-temperature the magnetic susceptibility decreases and the directionality strongly decreases to 4% at T = 45 K. We also propose an alternative design based on a non-magnetic (In,Ga)As/(In,Al)As quantum well structure, suitable for higher temperatures. According to our calculations, such structure can demonstrate emission directionality up to 5% for temperatures below 200 K and moderate magnetic fields of 1 T.Comment: 15 pages, 10 figure

Higgs Bosons Production with Photons at Lepton-Antilepton Colliders

By model independent way scalar and pseudoscalar neutral Higgs boson production with photon in the tree process $\mu^+\mu^- \to H^0 \gamma$ are considered.For the Standard Model and Minimal Supersymmetric Standard Model cases numerical estimates are obtained.The model independent flavour changing Higgs bosons production in the tree processes $e^+e^-,\mu^+e^- \to H^0_{fc} \gamma$ is also considered.Comment: 12 pages, LaTeX file, using eps.sty, 4 ps figures include