Cutting Edge Geometry Effect on Plastic Deformation of Titanium Alloy

The paper presents experimental studies of ОТ4 titanium alloy machining with cutting edges of various geometry parameters. Experiments were performed at a low speed by the scheme of free cutting. Intensity of plastic shear strain was set for defining of cutting edge geometry effect on machining. Images of chip formed are shown. Estimation of strain magnitude was accomplished with digital image correlation method. Effect of rake angle and cutting edge angle has been studied. Depth of deformed layer and the area of the plastic strain is determine. Results showed that increasing the angle of the cutting edge inclination results in a change the mechanism of chip formation

Landau Level Crossings and Extended-State Mapping in Magnetic Two-dimensional Electron Gases

We present longitudinal and Hall magneto-resistance measurements of a ``magnetic'' two-dimensional electron gas (2DEG) formed in modulation-doped Zn$_{1-x-y}$Cd$_{x}$Mn$_{y}$Se quantum wells. The electron spin splitting is temperature and magnetic field dependent, resulting in striking features as Landau levels of opposite spin cross near the Fermi level. Magnetization measurements on the same sample probe the total density of states and Fermi energy, allowing us to fit the transport data using a model involving extended states centered at each Landau level and two-channel conduction for spin-up and spin-down electrons. A mapping of the extended states over the whole quantum Hall effect regime shows no floating of extended states as Landau levels cross near the Fermi level.Comment: 10 pages, 4 figures, submitted to Phys. Rev.

Composite silicide-oxide coatings on refractory metals

Translated from Russian (Fiz. Khim. Obrab. Mater. 1995 (6) p. 51-57)SIGLEAvailable from British Library Document Supply Centre-DSC:9023.190(VR-Trans--9230)T / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Interference immunity fire alarm system on the basis of a laser fiber optic smoke detector

Приведено описание конструкции лазерного оптоволоконного дымового извещателя, обеспечивающего повышенную устойчивость к воздействию электромагнитных полей систем пожарной сигнализации, использующих его в качестве средства обнаружения пожара. Обнаружение дыма данным извещателем осуществляется по уменьшению регистрируемой приемником излучения интенсивности светового потока вследствие частичного поглощения и рассеянии его на частицах дыма. Высокая помехоустойчивость системы пожарной сигнализации на базе лазерного оптоволоконного извещателя, обусловлена отсутствием подводимых к извещателю от прибора приемо-контрольных длинных электропроводных линий питания и связи, играющих роль эффективных приемных антенн случайных электромагнитных полей. Изложены результаты апробации работоспособности предложенной конструкции извещателя, свидетельствующие о его высокой чувствительности обнаружения возгорания. The work describes the construction of a laser fiber-optic smoke detector that has enhanced immunity to electromagnetic fields of a fire alarm system, by using it as a mean of fire detection. The assessment of smoke concentration in this detector is conducted by reduction of the registered luminous flux radiation due to its partial absorption and scattering on the smoke particles. High interference immunity of fire alarm systems based on the use of a laser fiber-optic detector is conditioned by the absence of long power supply lines and connection with the control device that are used as effective receiving aerials of random electromagnetic fields. The results are presented on the tests for efficiency of the proposed construction of the detector proving its high sensitivity of fire detection