Predicting Oil Ring Self-Lubricated Sleeve Bearing Temperature Rise and its Effect on Shaft Criticals

Several steps are involved in predicting the temperature rise within the babbitt/oil film of sleeve bearings. Initially, the viscous friction loss developed in the oil film is determined. This loss depends on the speed, length, and diameter of the journal, oil viscosity, and diametral clearance. A heat balance study then compares heat loss generation and dissipation rates. The final consideration is the ability of the oil rings to deliver the necessary oil flow rate. An approach for predicting sleeve bearing temperature rise and the adequacy of oil ring lubrication is described. It is shown that some of the design variables affecting the bearing temperature rise also influence the bearing oil film stiffness. The value of this stiffness plays a vital role in determining the shaft critical speed.     

Metasurface based pattern reconfigurable antenna for 2.45 GHz ISM band applications

In this article, a Z‐shaped antenna is designed for 2.45 GHz ISM band applications. The proposed antenna is surrounded by metasurface‐based unit cells. The unit cells are designed to reflect for the proposed frequency. Each of this unit cells are activated with the help of a diode. Unit cell is considered active by switching on the diode of respective unit cell. According to the activation of unit cell the pattern of the antenna will be reconfigured. The 2.45 GHz ISM band pattern reconfigurable microstrip antenna is presented. The radiation pattern of the antenna can be steered toward a desired direction by activating appropriate metasurface unit cell, minimizing the interference and optimizing medium usage. The proposed antenna performance is presented with the help of reflection coefficient and the pattern steerable capability by activating metasurface unit cells. The proposed antenna is having azimuth‐pattern reconfigurable capability around 360°.     

Two milling time regimes in the evolution of magnetic anisotropy of mechanically alloyed soft magnetic powders

The milling time evolution of magnetic anisotropy of ball milled powders can be described considering two regimes. First, for short milling times, the main factor affecting the magnetic behavior of the alloy is the accumulation of internal stresses. Second, for long milling times, magnetic anisotropy can be explained using three contributions: long-range magnetoelastic, averaged short-range magnetoelastic and averaged magnetocrystalline anisotropies.     

Effect of different mixers on physicochemical properties and water status of extruded and laminated fresh pasta

Physicochemical properties and water status of fresh pasta (both extruded and laminated) produced with recently designed mixers (Premix^® and Bakmix^®) that induce a uniform hydration of the solids and allow the formation of a dough in 1–2 s were evaluated.     

Stopped flow kinetic-spectrophotometric determination of Diquat in waters

Using the measures of initial reaction rate, a kinetic-photometric method is developed that uses the reaction of Diquat with H2O2 in basic medium. The reaction rate is very high and therefore the stopped-flow mixing technique is required in order to make kinetic measurements. The reaction rate is obtained in 20 s after the reactants are mixed and it allows the simple application of the method proposed to the routine analyses. The sensitivity of the method is very high being the detection limit 0.44 microgmL(-1) and the application range between 1 and 16 microgmL(-1). The time of measure per sample is 90s. The proposed kinetic-photometric method has been applied to the direct determination of this compound in river water, in the water of laundry of the olives, and in a commercial product. The results are very acceptable.     

Optical and structural behaviour of Mn implanted sapphire

Sapphire single crystals were implanted at room temperature with 180 keV manganese ions to fluences up to 1.8 × 10¹⁷ cm⁻². The samples were annealed at 1000 °C in oxidizing or reducing atmosphere. Surface damage was observed after implantation of low fluences, the amorphous phase being observed after implantation of 5 × 10¹⁶ cm⁻², as seen by Rutherford backscattering spectroscopy under channelling conditions. Thermal treatments in air annealed most of the implantation related defects and promoted the redistribution of the manganese ions, in a mixed oxide phase. X-ray diffraction studies revealed the presence of MnAl₂O₄. On the contrary, similar heat treatments in vacuum led to enhanced out diffusion of Mn while the matrix remained highly damaged. The analysis of laser induced luminescence performed after implantation showed the presence of an intense red emission.