Echoes of the Month
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چکیده
Speaking on " National Decay and Regeneration" at Edinburgh, the Dean of St. Paul's said that only one kind of natural selection was favoured by modern life?that against disease. That had gone on so rapidly that most of the epidemics which formerly ravaged the cities had assumed a much milder type, and were far less destructive to life. To introduce a savage into any European town was to sentence him to certain death. The modern man might be physically a poor creature, but he had developed a new power of resisting microbes. It was the unexampled decline in the death-rate, due partly to sanitation and medical skill, but partly also to increased adaptation to town life, which had created the very menacing problem of over-population, to which the most bigoted could no longer shut their eyes, with a million unemployed to feed out of the taxes. The decline in the birthrate from 36 in 1878 to 20 in 1922 had prevented a social revolution, and the death of many millions by famine, but it had not gone far enough. The decline in the rate was itself dangerous, because it was steadily impairing the quality of the population. They were breeding from the bottom and dying off at the top. In each generation the cream of all classes was slammed off, raised to a better social position, and there sterilised. Among the finest strata of the population, physically, intellectually, and morally, were the members
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Investigation of the Relationship between Ultrasonographic Findings and Analyses of Bladder Contents in Cats
Background: Echoes are frequently observed in cat bladder contents through ultrasonography and often mentioned as incidental findings. No comprehensive study has been conducted so far on the precise echoes nature in the bladder contents ultrasonography in cats. OBJECTIVES: The purpose of this study is to provide an accurate description of the cat bladder contents echoes and to specify the relat...
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Time-Delay-Estimation (TDE) has been a topic of interest in many applications in the past few decades. The emphasis of this work is on the application of model-based estimation (MBE) for TDE of ultrasonic signals used in ultrasonic thickness gaging. Ultrasonic thickness gaging is based on precise measurement of the time difference between successive echoes which reflect back from the back wall ...
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The results of ultrasonic tests are usually displayed as A-scan signals. In an A-scan signal, reflections of ultrasonic wave form different reflectors are shown as sharp echoes on a time by amplitude display. Interpretation of these echoes can sometimes be quite difficult and usually requires knowledgeable and experienced specialists. There exist other methods of displaying the ultrasonic test...
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