Development of a spectrofluorimetry-based device for determining the acetylene content in the oils of power transformers.

Power transformers are essential for a functioning electrical system and therefore require special attention by maintenance programs because a fault can harm both the company and society. The temperature inside a power transformer and the dissolved gases, which are primarily composed of acetylene, are the two main parameters monitored when detecting faults. This paper describes the development of a device for analyzing the acetylene content in insulating oil using spectrofluorimetry. Using this device introduces a new methodology for the maintaining and operating power transformers. The prototype is currently operating in a substation. The results presented by this system were satisfactory; when compared to chromatographic data, the errors did not exceed 15%. This prototype may be used to confirm the quality of an insulating oil sample to detect faults in power transformers.

[Pathomorphological and cytogenetic studies of embryonic abortions]. / Pathomorphologische und zytogenetische Untersuchungen embryonaler Aborte.

Cytogenetic studies into abortions have shown that in 50 to 60% of all abortion cases the presence of an aneuploid karyotype can be concluded simply from the histological findings obtained from the abortion sample. This has proved to be important not only for elucidation of the cause of abortion. Also, some cytogenetic studies have provided statistically useful information for counselling on the risk of repetition. However, there are also views according to which the risk of recurrence is not even increased in the wake of aneuploid abortion. Including in our investigation were 528 samples received by routine at the Charité Institute of Pathology from the Charité Obstetric Department, between October 1987 and June 1990. Macroscopic findings included 24 intact amniotic sacs with and 34 without embryonic fragments as well as 188 ruptured amniotic sacs. Only decidual particles were found in 249 cases, while no safe macroscopic assessment was possible of 33 samples. Investigation of the embryos proved to be essential to identification of malformations and determination of discrepancies between gestational age and embryonic development. Correlations were also established between age-specific incidence of abortions and age-specific fertility, with the risk of abortion being found to grow beyond the age of 30 years. Histological parameters recorded from 267 samples revealed links to specific chromosomal aberrations, with 136 of them (50%) being defined as chromosomally induced abortions. Seventeen in 34 abortions on which cytogenetic results had been obtained proved to be aneuploid, among them nine aberrations of trisomal karyotype. A triploid karyotype was exhibited by four and a monosomal karyotype by three. Mosaic was recorded in one case.(ABSTRACT TRUNCATED AT 250 WORDS)

Rare and endangered species of plants--the soviet side.

In late 1972, the Soviet Union embarked on a program to identify and document plant species that are threatened with extinction. Perhaps 2000 species in the Soviet Union are in need of monitoring or protective measures, while nearly 200 may be in immediate danger of extinction. Currently, the Soviet Union has an official, national list of endangered species, and each of the 15 republics has prepared a regional list. Once a revised national list is prepared, Soviet scientists hope that the Supreme Soviet will pass a law protecting those species. A corresponding law for endangered animals was passed in 1980.

Nectar: its production and functions in trumpet creeper.

Studies of the trumpet creeper, Campsis radicans (L.) Seem. (Bignoniaceae), reveal five distinct nectary systems, a phenomenon never before reported among temperate zone plants. Ant activity, centered around the four extrafloral systems, clearly demonstrates the ant-guard symbiosis usually associated only with tropical or subtropical species. Floral nectar, an attractant for hummingbird and bumblebee pollinators, differs chemically from the ant-attracting nectar produced extraflorally.