Das Blitzkugelverfahren zur Bestimmung der Blitzstromamplituden möglicher Blitzeinschläge

The rolling sphere method is recommended by IEC and CENELEC to identify the protected space of parts and areas of a structure and to determine the protection zones LPZ O_A and LPZ O_B for an object. Equipment not entirely inside LPZ O_B has to be protected against maximum lightning peak currents up to 200 kA. In this paper we show that in many cases this is not realistic and uneconomical. A more sophisticated analysis based on the physical background of the electro-geometric model often provides a more realistic and less expensive solution.     

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Dopplerographic assessment of the autoregulation of the blood supply to the brain in neurosurgical pathology

The development of an informative, noninvasive technique for evaluating the reserve of the cerebral circulatory system is a topical task of clinical angioneurology. The authors developed methods of Doppler evaluation of an autoregulatory response from hyperemic changes after short-term regional hypotension caused by digital compression of the cervical carotid. They calculated the indices acceptable in routine clinical practice, defined the range of their values in health and in typical variants of cerebral circulatory insufficiency in patients with disseminated neurosurgical pathology. The carotid compression test by recording linear blood flow velocity in the cerebral arteries is a safe, valid, and reproducible method of semiquantitative assessment of the autoregulation reserve which may be used to determine the tension of resistive vessels in the middle cerebral arterial bed as an important index of the functional status of the cerebral circulatory system.     

Specific features of the physical processes of mechanical failure

Translated from Fiziko-Khimicheskaya Mekhanika Materialov, No. 3, pp. 77–81, May–June, 1988.     

The effect of cytochrome c preparations on the autoregulation of the cerebral blood flow in ischemia

The effect of animal cytochrome C (Ca), biotechnological cytochrome (Cb) and its hemtetradecapeptide (HTDP) on cerebral blood flow autoregulation during rapid decrease of systemic arterial pressure (SAP) was studied in acute experiments on rats. Cytochrome C preparations caused no effect on the autoregulatory responses of the cerebral vessels in animals with normal cerebral circulation. Injection of 5 mg/kg Ca and Cb and 0.8 mg/kg HTDP promoted restoration of the phenomenon of cerebral blood flow autoregulation in ischemic brain damage in change of SAP from 120 to 60 mm Hg. Prophylactic injection of 20 mg/kg Ca and Cb and 3.3 mg/kg HTDP prevented cerebral blood flow autoregulation disturbance caused by transitory brain ischemia.     

Perceived barriers and biases in the medical education experience by gender and race

This study examined barriers and biases in the medical education experience by surveying fourth-year medical students. There were 270 female and 288 male respondents; their racial background was: 21% Asian, 13% underrepresented minorities, and 66% white. Women reported that the careers they were encouraged to pursue were affected by their gender (44% versus 15%) and they were often mistaken for a nonphysician (92% versus 3%). More importantly, women reported that the lack of a mentor of either gender as a large barrier (27% versus 19%). Underrepresented minorities reported that their race caused them to feel that they had to be twice as good to be treated as an equal to other students (52% versus 6%). Underrepresented minorities identified the lack of a same-race mentor (23% versus 4%) and role model (40% versus 1%) as a large barrier. Underrepresented minorities also noted an overall lack of mentors as a large barrier (25% versus 19%). Women and underrepresented minorities from the class of 1996 reported having a medical school experience characterized by similar barriers to their professional development.     

Metrological properties of a meter for the temperature of the tuyere zone of a blast furnace

Conclusion Investigations of the basic parameters of the radiation pyrometer telescopes PRK-602U showed complete acceptability for measurement of the temperature of the tuyere zone of a blast furnace. The resultant data also show that with respect to the basic parameters the telescopes satisfy the requirements of GOST 6923-68, which provides the basis for formulating the problem of organizing them for mass production.Translated from Izmeritel'naya Tekhnika, No. 12, pp. 68–70, December, 1972.     

Organizational problems of the production of biological preparations of blood

The trend of the incidence of tick-borne encephalitis makes one pay attention to the production of blood biological preparations. A detailed programme for improving the production process, which is included into the federal and republican programmes, is outlined.     

An evaluation of the functional possibilities of the deep femoral artery and its branches as potential outflow pathways in arterial reconstruction

Computer diagnostic system (CDS) Reflexotest based on the Nakatani method with the use of IBM PC/AT personal computer noticeably facilitates data accumulation and processing. It is a new non-invasive and simple electrophysiological method providing information on the status of autonomic nervous system which is indirectly indicative of functional capacity of different organs and systems. CDS efficacy is illustrated on 12 cases with chronic renal insufficiency (4 patients in compensation, 8 in terminal stages) who demonstrated low mean potential of biologically active points (BAP) and unbalance of potentials specific for different meridians. In patients with positive treatment effects there was a tendency to better BAP parameters. Deterioration of clinical condition was also reflected by BAP evidence. CDS Reflexotest is recommended for practice as a promising adjuvant diagnostic method.