Interband light absorption in size-confined systems in uniform electric fields

A simple approach to calculation of the interband absorption coefficient in a uniform electric field is developed. This approach provides a means for studying the special features of electroabsorption in a wide class of semiconductor systems on the basis of the most general relationships. The approach is used to study the electroabsorption in two-dimensional systems with different profiles of their one-dimensional potential, quantum wells, and superlattices in magnetic fields.     

The Griffith energy problem for brittle polymers

A number of problems concerning the Griffith criterion for brittle polymers have been considered. A general formula for the energy of deformation of a stressed sample with surface and internal cracks has been derived. This energy was calculated simultaneously for the plane and plane-deformed states of this sample. The commonly accepted view that the Griffith criterion determines a quasi-safe stress that differs markedly from the athermal-fracture criterion was verified. __________ Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 80, No. 1, pp. 156–165, January–February, 2007.     

Reliability and Validity of the Revised Children's Manifest Anxiety Scale in a French-Canadian Sample.

The aim of this study was to examine the reliability and validity of a French version of the Revised Children's Manifest Anxiety Scale (RCMAS). A sample of 2,666 school-age French-Canadian children completed the questionnaire. With regard to factor structure, the 5-factor model found in U.S. normative samples was confirmed. The internal consistency of the 5 scales and of the 2 global scales was good to excellent. Test-retest reliabilities after a 6-month period were also similar to those of the original version. Finally, the concurrent validity, assessed by a correlation with the State-Trait Anxiety Inventory for Children, was also found to be good. Results of the present study show that the French version of the RCMAS is a good instrument to assess anxiety in children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Correlation relations for estimating the content of plutonium isotopes in fallout due to the Chernobyl accident

The possibility of determining the total α activity A(^239,240Pu) of ²³⁹Pu + ²⁴⁰Pu according to the γ radiation of ¹⁰³Ru and ¹⁰⁶Ru is examined. The statistical properties of the experimental ratios of the activities ρ = A(¹⁰⁶Ru)/A(¹⁰³Ru) are investigated. The distribution of the experimental ratios is similar to the theoretical ratios for fuel and close to a Gaussian distribution with average value 〈p〉 = 0.22 and standard deviation Δ ∼ 0.06. This ratio is used to obtain a relation for estimating A(^239,240Pu) from the γ activity A(¹⁰³Ru). A theoretical analysis is made of the experimental data for the southern raions of Gomel oblast. It is shown that given a good statistical sample of measurements of the γ activity of ¹⁰³Ru it is possible to estimate the average value of the γ activity A(^239,240Pu) and with probability 0.95 the interval of the possible values of this activity. __________ Translated from Atomnaya énergiya, Vol. 103, No. 4, pp. 255–259, October, 2007.     

Effect of oral acyclovir or ganciclovir therapy after preemptive intravenous ganciclovir therapy to prevent cytomegalovirus disease in cytomegalovirus seropositive renal and liver transplant recipients receiving antilymphocyte antibody therapy

BACKGROUND: Organ transplant recipients who are seropositive for cytomegalovirus (CMV) and who are treated with antilymphocyte antibody (ALA) therapy have a high rate of symptomatic CMV disease. The intravenous administration of ganciclovir therapy once daily during ALA therapy decreased the incidence from 24% to 10% in patients receiving ALA as an induction therapy and from 64% to 22% in those treated for rejection. The present study was undertaken to determine whether a more intensive and sustained antiviral regimen could be more effective. METHODS: From April 1995 to December 1997, all CMV seropositive renal and liver transplant recipients who received ALA therapy were treated with intravenously administered ganciclovir (5 mg/kg/day with dose adjusted for renal dysfunction) for the length of ALA therapy and then with orally administered acyclovir (400 mg three times/day) or ganciclovir (1 gm twice/day) for 3 to 4 months. The incidence of CMV viremia and of CMV disease was determined during the 6 months after completion of ALA therapy. RESULTS: Forty-one patients (35 renal and 6 liver transplant recipients) were studied. CMV disease occurred in 2 patients (4.9%), both of whom were treated for rejection; it occurred in 1 of 21 patients (4.8%) treated with orally administered acyclovir, and in 1 of 20 patients (5%) treated with orally administered ganciclovir. The only patient who developed CMV disease in the ganciclovir group had received only 26 days of oral antiviral therapy. No CMV disease was documented in the group of patients receiving ALA therapy as induction therapy. CMV viremia occurred in three patients in the acyclovir group (14.3%) and in one patient in the ganciclovir group (5%). Among renal transplant recipients only, 1 of 35 patients developed CMV disease (2.9%) and no case of CMV disease was documented in patients treated with orally administered ganciclovir. All six patients receiving two courses of ALA therapy each were free of CMV disease. Toxicity of the regimen was minimal, and antiviral resistance did not develop. CONCLUSIONS: Preemptive antiviral therapy with intravenously administered ganciclovir during ALA therapy and then orally administered ganciclovir for 3 to 4 months provides virtually complete protection against the excessive rate of CMV disease that occurs in CMV seropositive allograft recipients receiving ALA therapy.     

The structure of thermomigration channels in silicon

We have studied deep and through channels formed in n-Si wafers by means of thermal migration of thin discrete aluminum zones. The region of thermal migration channels was investigated using selective chemical etching of silicon in combination with secondary ion mass spectrometry for the analysis of impurity distributions. It is established that the channels are surrounded by two distinct peripheral shells.     

Optical and electrical properties of polyamide acid and metal-polymer complex based on terbium

The basic optical and electrical properties of polyamide acid and its complex with Tb⁺² have been studied. The occurrence of room-temperature photoluminescence (PL) with an emission peak at 520 nm is established. The activation energy of conductivity at temperatures above 350 K is 2.1 eV. Polyamide acid is comparable in PL intensity with an electroluminescent polymer, poly(p-phenylvinylene).     

Distribution propagation in estimating measurement uncertainty

Arguments are presented that show that it is ineffective to replace distribution propagation by uncertainty propagation in estimating the uncertainty of measurements, which has a bearing on the accuracy and difficulty of estimating indirect-measurement uncertainties with nonlinear transformations from input data. __________ Translated from Izmeritel’naya Tekhnika, No. 2, pp. 15–18, February, 2008.     

Some characteristics of soil stabilization by “sealed” injection using microcement

Characteristic features of “sealed injection” for the microcement stabilization of the saturated soils between the Serebryanovorsk transportation and service tunnels in Moscow are examined. __________ Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 1, pp. 25–28, January–February, 2008.