311 research outputs found
Measuring the Pulse Duration of a Femtosecond Laser Using Intensity Autocorrelation
In this experiment, an intensity autocorrelator is set up in order to measure the pulse duration of a passively mode-locked Titanium-Sapphire laser with a power of 267mW producing femtosecond pulses. Then this measurement, as well as a measurement of the laser’s spectrum, is used to test the Uncertainty Principle. Intensity autocorrelation is a well-established technique for measuring pulse duration, and is among the more intuitive techniques for this purpose, which is why it was selected for this experiment. The experimental setup was computerized. The delay of one half of the pulse was controlled by a motorized translation stage which was itself controlled by a computer which could scan across the zero delay point of the pulse, and the data from the detector went to a digital oscilloscope and was then saved by a computer. Dispersion was compensated for by negative dispersion mirrors in the laser itself. To calculate the duration of the pulse, it was assumed that the pulses took the shape of sech^2(x). The duration of the laser pulses was determined to be 12.9 fs. The standard deviation of the pulse in time was found to be 6.6 fs, and the standard deviation of the pulse in energy was 1.15*10^(-20) J. When multiplied, the standard deviations give a value of 7.6*10^(-35) Js or 0.72 ħ, which is greater than the theoretical minimum limit given by the Uncertainty Principle of 0.50 ħ
Die Handwerkssprache der Drucker und Setzer
Die Seminararbeit beschreibt die Drucker- und Setzersprache einhergehend mit der Entwicklung dieses Berufsstandes. Nach einer kurzen Begriffsklärung wird die Geschichte des Druckereiwesens nachgezeichnet, um danach auf die Merkmale der Druckersprache einzugehen. Einen eigenen Teil dieser Arbeit bildet die Vorstellung besonders humoristischer Begriffe, die die Druckerzunft hervorgebracht hat. Dabei wird versucht, auf die etymologischen Ursprünge solcher Termini einzugehen. Im Anhang findet sich ein Wörterbuch der Drucker- und Setzersprache, welches aus verschiedenen Quellen zusammengetragen wurde. Durch die Kombination von Historismen seit etwa 1440 und neuer Fachtermini bis 2016 bietet dieses Wörterbuch einen Abriss der Drucker- und Setzersprache von ihrem Beginn bis heute.:1. Einleitung 02
2. Begriffliche Abgrenzungen 02
3. Geschichte des Druckens mit beweglichen Lettern 03
4. Charakteristika der Druckersprache 05
5. Humorismen und ihre Etymologie 07
6. Lexikologische Hintergründe 09
7. Lexikographische Hintergründe 10
Literaturverzeichnis 13
Anhang 1: Vorstellungsgespräche im Zeitwandel 14
Anhang 2: Wörterbuch der Druckersprache 1
Uticaj hrane sa različitim udelom masnih kiselina na stresne reakcije kod šarana (preliminarni rezultati)
Riblje brašno i riblje ulje su važne komponente riblje hrane koja se koristi u akvakulturi. Oni sadrže nezasićene masne kiseline koje su važne kako u ishrani riba tako i u ishrani ljudi. Međutim, izvori ribljeg brašna i ulja su ograničeni. Cilj AQUAMAX projekta, koga finansira EU, je da se riblje brašno i ulje zamene ili dopune sa biljnim uljima. Tim za imunologiju u Institutu za ribarstvo, akvakulturu i irigaciju ispitivao je efekat dve različite hrane za ribe (hrana dostupna na tržištu i hrana sa dodatkom Camelina ulja) na pojavu stresa izazvanog ograničenim prostorom kod šarana. Na bazi rezultata ovog istraživanja može se zaključiti da primenjena ishrana nema uticaja na toleranciju šarana na stres izazvan ograničenim prostorom
The Effect of Supplementation on Selenium and Zinc Content in Blood and Milk of Dairy Cows
Milk is an important source of microelements for calves during the suckling period as well as in human nutrition. Concentration of trace elements in blood and their secretion via milk can significantly change depending on food intake and composition. Proper control of selenium and zinc content in blood and in milk can improve the status of these microelements, so that the occurrence of deficiency or excessive quantity due to their increased intake can be prevented. This paper presents the results of the study on the concentration of selenium and zinc in the blood and milk of diary cows whose rations have been supplemented by organic forms of selenium (0.2 mg/kg DM) and zinc (40 mg/kg DM) during the last ten days of dry period and early lactation. Supplemented cows in trial groups A and B achieved significatly higher concentrations of these microelements in blood (Se 186.70±8.50 µg/L vs. 118.80±7.05 µg/L), blood serum (Zn 1204.70±109.5 µg/L vs. 1095.40±130.2 µg/L) and milk (Se 57.30±8.05 vs. 21.30±4.60 µg/L; Zn 2893.90±120.15 µg/L vs. 1952.10±130.50 µg/L) on 60th day postpartum compared to non-supplemented control
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