Frequency-time method of correcting measurements of the radiation patterns of antennas

This article examines the mathematical aspects of a method developed for frequency-time correction of distortions of radiation patterns recorded in a closed range with partial echo suppression. The efficiency of the method is analyzed with allowance for the dimensions of the range and the bandwidth of the test antenna. Translated from Izmeritel'naya Tekhnika, No. 12, pp. 44–46, December, 1996.     

Improving the accuracy of measurements of rotation of the plane of polarization

The feasibility of improving the accuracy of measurement of the angle of rotation of the polarization plane in the application of diffraction methods is investigated. Translated from Izmeritel'naya Tekhnika, No. 4, pp. 32–34, April, 1996.     

Acute arthritis of cats associated with feline calicivirus infection

Twelve specific pathogen-free cats were infected either by intra-articular inoculation or by contact exposure to one of two strains of feline calicivirus (FCV), either F65, a field strain originating from an outbreak of lameness in a group of cats, or a vaccine strain. Following either route of exposure, both strains induced signs typical of FCV infection including oral and nasal ulceration, conjunctivitis and ocular discharge. These signs were of equal severity for both virus strains, but overall, following either route of infection, F65 induced more severe disease than the vaccine strain, with marked pyrexia, lethargy and lameness. Vaccine virus only induced a relatively mild lameness following intra-articular inoculation. Gross pathological and histopathological lesions were seen in some of the joints, but again changes were more severe in the F65-exposed cats. Virus was isolated from both normal and affected joints from both groups of F65-exposed cats, and from a joint from each cat inoculated intra-articularly with vaccine virus. Mild transient lameness was also seen in one of two control cats inoculated intra-articularly, but no pathological changes were seen or virus isolated from joints. A cDNA probe used in RNA dot blot hybridisation experiments was found to be specific and more sensitive than virus isolation in detecting FCV in selected tissues. This may be useful in future studies on the pathogenesis of FCV disease and in studies on viral persistence in FCV carriers.     

Inaccuracies in estimates of life expectancies of patients with bronchial cancer in clinical decision making

Cell cultures were derived from adult human brain biopsies [from cortical gray (cultures 9-HB-G and 33-HB-G) and white (culture 14-HB-W) and stroke-injured white matter (culture 33-HB-IW)]. The morphology and growth rate of cultured cells were examined and correlated with the presence of vimentin and glial fibrillary acidic protein (GFAP). The cultures from various brain matters differed in cell morphology and rate of growth but not in GFAP and vimentin staining. Cells of primary and rapidly proliferating cultures were GFAP-negative and vimentin-positive. Spontaneous growth deceleration occurred in culture 14-HB-W within passages 5 to 10 and in cultures 9-HB-G, 33-HB-G, and 33-HB-W within passages 17 to 20. This deceleration, as well as the successive complete growth arrest, were accompanied by an appearance of GFAP-positive cells and an elevated intensity for vimentin staining. We propose that GFAP-positive astrocytes originate from glial precursor cells that migrate from the explants and differentiate under prolonged subcultivation.     

Ultrasonic evaluation of environmental durability of adhesive joints

An angle-beam ultrasonic technique is used to investigate the interfacial properties of lap shear adhesive joints subjected to severe environmental degradation under load. The mode of failure during the process of degradation changes from cohesive (through the bulk adhesive) to predominantly interfacial (along the adhesive/adherent interface). It is found that the minimum shift in the frequency spectrum of the reflected ultrasonic signal is more sensitive to changes of properties in the interphasial region than in the bulk adhesive. The shift of the minimum to lower frequencies is related to the fraction of interfacial failure area and to the joint strength. This could lead to a methodology for predicting the residual lifetime of the joint in service. The joint degradation is described by a mathematical model of an adhesive joint with nonhomogeneous interphase structure. Reasonable agreement between the experimental results and computer simulations on the basis of the proposed model is obtained.     

Maternal-fetal T4 transfer does not suffice to prevent the effects of in utero hypothyroidism

It has been suggested recently that in congenitally hypothyroid infants with organification defect there is a maternal-fetal transfer of thyroxine (T4). The present study was conducted to evaluate how effective the maternal-fetal transfer is and whether the maternal T4 can prevent intrauterine hypothyroidism. The clinical, laboratory and radiological data on 271 full-term infants with persistent primary congenital hypothyroidism, detected by the national screening program, were used to assess the degree of in utero hypothyroidism. For 6 out of 50 athyroid infants, two pretreatment blood samples spotted on filter paper were available for calculating the T4 disappearance rate. Most infants with agenesis of the thyroid had very low T4 and very high levels of thyroid-stimulating hormone compared to infants with ectopic thyroid. In the athyroid infants the initial T4 declined to low and undetectable levels. Bone maturation was significantly delayed while the clinical symptomatology was more prominent in the athyroid congenital hypothyroid infants, as compared with the ectopic thyroid infants. In conclusion, there is some maternal-fetal transfer of T4. However, this transfer is insufficient to suppress the fetal levels of thyroid-stimulating hormone and prevent intrauterine hypothyroidism.     

Does the gender of a patient or the gender of a therapist affect the treatment of patients with major depression?

The role of gender was examined in the process and outcome of therapy in the treatment of depressed outpatients seen in the National Institute of Mental Health Treatment of Depression Collaborative Research Program. Patients received either interpersonal therapy, cognitive-behavioral therapy, imipramine plus clinical management, or placebo plus clinical management. None of the therapist-patient by gender groupings (i.e., therapist gender, therapist-patient gender matching vs. mismatching, or patients' beliefs about whether a male or female therapist would be more helpful) were significantly related to measures of treatment process and outcome, controlling for type of treatment and severity of pretreatment depressive symptoms. Findings were duplicated when examining the effects of gender within only the psychotherapeutic modes of treatment for the groupings of therapist gender and therapist-patient gender matching versus mismatching.     

Trends in the development of automated control systems in the production of optoelectronic equipment

Automated systems for monitoring the physical parameters and controlling the processes involved in the design and fabrication of optoelectronic equipment is analyzed. Various techniques for implementing such systems and the trends in the further development and improvement of such systems are pointed out. Translated from Izmeritel'naya Tekhnika, No. 7, pp 36–39, July, 1996.     

Effect of heat-ageing on the thermal and mechanical properties of APP- and SBS-modified bituminous roofing membranes

The effect of heat-ageing on four bituminous roofing membranes, two modified with atactic polypropylene (APP) and two modified with styrene-butadiene-styrene (SBS) was studied using tensile testing and dynamic mechanical thermals analysis (DMA). The samples were heated at 80°C for 7, 28, 84 and 168 days and were tensile tested at 23, 0, −10, −20 and −30°C. Each heat-aged sample was also subjected to thermomechanical testing to find its glass transition temperature T _g . The results show significant variation in the effect of heat-ageing on tensile strength and elongation of membranes. T _g values differ with the modifiers and other ingredients of the membranes and are affected by heat-ageing. The influence of the glass transition zone measured by DMA is also reflected in the tensile test results.

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Resume On a étudié l’influence du vieillissement par la chaleur sur quatre membranes d’étanchéité, deux d’entre elles étant traitées par APP (polypropylène atactique) et deux par SBS (styrène de styrène butadiène), à l’aide de l’essai en traction et de l’analyse thermique mécaniques (DMA). Les échantillons ont été chauffés à 80°C pendant 7, 28, 84 et 168 jours et essayés en traction à 23, 0, −10, −20 et −30°C. Chaque échantillon vieilli par la chaleur a été également soumis à un essai thermomécanique pour identifier sa température de passage à l’état vitreux T _g . Les résultats montrent des différences importantes dans l’influence de la chaleur sur la résistance en traction et l’allongement des membranes. Les valeurs de T _g diffèrent selon les traitements et les autres composants des membranes, et sont affectées par le vieillissement par la chaleur. L’influence de la zone de passage à l’état vitreux mesurée par l’analyse thermique mécainique se traduit aussi dans les résultats de l’essai en traction.