Use of biocompatible calcium-phosphate glass ceramic BGC in surgical treatment of maxillary cysts

The possibility of using the granulated form of biocompatible material made of calcium-phosphate glass ceramic BGC for treatment of maxillary cysts was demonstrated.     

Stable operation range for laser diodes with an integrated passivecavity in the presence of external optical feedback

It is shown that a laser diode with an integrated passive cavity yields higher tolerable levels of feedback from distant reflections than an equivalent long solitary laser diode. To ensure this high tolerance for external feedback, the internal feedback level in the integrated passive cavity must be of the order of about 10%. Then the laser diode remains stable up to external feedback levels in excess of 1% even if the internal reflection phase is not carefully adjusted. External reflections from a cleaved fiber end are then not sufficient to drive the laser into coherence collapse, if realistic coupling efficiencies between laser diode and fiber are taken into account. The low feedback sensitivity is explained by the combination of the long effective length of the laser and a high relaxation resonance frequency. Therefore, quantum-well laser diodes with a long length and a high relaxation resonance frequency are likewise expected to exhibit low feedback sensitivity     

Effects of arylthio-and arylseleno(methoxy)methanes on acid corrosion of CT 3 steel

The effects of various arylthio-and arylseleno(methoxy)methanes on corrosion of CT3 steel in sulfuric and hydrochloric acid solutions were studied by gravimetric and voltammetric methods. Some compounds of theses classes were found to be effective inhibitors of the acid corrosion of CT3 steel. The presence of the-X-CH₂-O-CH₃ groups (X = S or Se) in aromatic amines and their derivatives enhanced their inhibitive properties. However, because these groups are highly hydrophobic, the molecules of inhibitors should contain other fragments that ensure sufficient solubility. Original Russian Text ? I.N. Chernyad’ev, A.B. Shein, A.N. Nedugov, 2007, published in Zashchita Metallov, 2007, Vol. 43, No. 3, pp. 285–289.     

Countercurrent water-heating system with a heat exchanger in a solar energy collector loop

The counter current heat exchanger theory with periodic inlet temperatures has been applied to analyze the thermal performance of a water heating system. The theoretical results obtained are in agreement with the experimental data reported in the literature.     

Correctness of an analytical solution of an inverse problem of heat conduction

We discuss the analytical solution of an inverse Cauchy boundary-value problem of heat conduction and analyze its correctness.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 49, No. 6, pp. 1015–1018, December, 1985.     

Error-free 10 Gbit/s transmission using individual Fabry-Perot modes of low-noise quantum-dot laser

A comb-generating laser suitable for DWDM application is demonstrated on the basis of a multimode quantum-dot laser. Bit error rate < 10^-13 at 10 Gbit/s external modulation was measured for 10 longitudinal modes owing to low (<0.3% over 0.001-10 GHz) relative intensity noise of each individual mode.