Increasing the Efficiency of Dewaxing in the Deoiling Stage

During selective treatment, the content of high–melting paraffins and naphthenes that crystallize from solution when the temperature is decreased increases significantly in lube oil cuts after removal of resins and asphaltenes and polycyclic hydrocarbons with short side chains. These hydrocarbons, which have a high melting point, are removed during dewaxing to obtain low-pour lube oil cuts.     

Temperature characteristics of low-threshold high-efficiency quantum-dot lasers with the emission wavelength from 1.25 to 1.29 µm

The temperature behavior of the operation characteristics of low-threshold (the threshold current density is below 100 A/cm²) high-efficiency (differential quantum efficiency is as high as 88%) injection laser heterostructures is studied. The active region of structures emitting in the range from 1.25 to 1.29 μm included two, five, and ten layers of InAs-GaAs quantum dots. It is shown that both the threshold current density and the external differential quantum efficiency become N-shaped functions of temperature as the distribution of carriers in the active region changes from nonequilibrium to equilibrium one. __________ Translated from Fizika i Tekhnika Poluprovodnikov, Vol. 37, No. 10, 2003, pp. 1270–1273. Original Russian Text Copyright ? 2003 by Novikov, Maksimov, Shernyakov, Gordeev, Kovsh, Zhukov, Mikhrin, Maleev, Vasil’ev, Ustinov, Alferov, Ledentsov, Bimberg.     

Choosing the setting parameters of an automatic regulator for controlling a floating device

A procedure is proposed which is based on the method of extended frequency characteristics and the principle of searching for values of setting parameters of regulators involving personal computer hardware and software. Translated from Izmeritel'naya Tekhnika, No. 2, pp. 19–21, February, 1998.     

Clinical course and treatment of herpetic trigeminal ganglionic neuropathy

45 patients were observed in the periods of both acute herpes zoster and postherpetic neuralgia (PHN). In most of the patients herpetic eruptions were located in the areas of innervation of the first branch of the trigeminal nerve. In acute period of the disease there were used aciclovir, helepin or alpisarinum, antiherpetic immunoglobulin, deoxyribonuclease, non-narcotic analgetics were used. Of 28 patients residual PHN was observed in 6 cases, delayed PHN (during 3 months)--in 2 patients. The PHN development was characteristic for elderly patients, delayed request for medical care, concomitant diseases, eruptions with hemorrhagic component and secondary pyodermia and considerable residual sensory deficit. In therapy of PHN the most effective drugs were amitriptylin, non-narcotic analgetics, anticonvulsants as well as acupuncture and electroacupuncture. Relief of a typical deafferentation of pain syndrome was achieved by means of ultrasonic destruction of the trigeminal nucleus (one case). Early therapy of acute herpes zoster does not prevent completely PHN development, but it decreased considerably probability of its forming as well as the severity of its course.     

Role of neurologic sciences in occupational medicine

The article presents possible neural disorders caused by occupational hazards and shows mechanisms underlying those disorders. The authors define topical problems of basic science related to occupational neurology, which require further studies with neurochemical, immunologic, neurophysiologic methods and comparison.     

Low-flow membrane oxygenation of blood in patients with diffuse purulent peritonitis

Small-flow membranous oxygenation of the blood was used in 45 patients with peritonitis in the multiple organ failure phase. In ten cases blood oxygenation was combined with hemofiltration. MOCT 19-03 (Kvant Research and Production Unit) and Gambro FH hemofilters (Sweden) were employed. Combination of small-flow membranous oxygenation of the blood combined with hemofiltration appreciably improved the oxygen-transporting function of the blood in adult patients with the respiratory distress syndrome, which was due to mutual potentiation of the two methods' effects. Small-flow membraneous oxygenation alone improved cellular immunity and decreased the laboratory manifestations of endogenous intoxication due to biotransformation of toxic products.