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06:01 IWF (Göttingen) English 1976

Oscillations of Molecules in Melamine Crystal Lattices with Hydrogen Bonds

Translatory and torsional vibrations of the molecules. Using melamine for an example, the elastic properties of the intermolecular hydrogen bonds are demonstrated. Using the thermally induced vibrations at 60 and 300 K it is shown, that they are the mechanical storage means of the specific heat of the melamine crystal.
  • Published: 1976
  • Publisher: IWF (Göttingen)
  • Language: English
21:26 IWF (Göttingen) English 1984

Chromatography - 1. Separation Procedures, Theory and Applications

Adsorption, distribution, ion exchange and gelatin permeation are the basic procedures which lead to a chromatographical fractionation of mixtures of substances, for examples, of dye pigment in a chromatographic system consisting of a mobile and a stationary phase. The kinetic theory, the theory of separation in stages and the van-Deemter equation provide the theoretical basis for this physical-chemical method of separation. The techniques of thin-layer chromatography, fluid-column chromatography and gas chromatography make it possible to combine separations with quantitative analyses in the form of various analysis systems.
  • Published: 1984
  • Publisher: IWF (Göttingen)
  • Language: English
13:16 IWF (Göttingen) English 1985

Activator-Inhibitor - A Model of Biological Pattern Formation

In the development of higher organisms, pattern forming reactions must be involved. In the movie, a yet hypothetical two-component reaction is analysed which is able to generate patterns. Computer simulations made on the basis of two coupled non-linear differential equations show the time course and the regulatory properties of this reaction.
  • Published: 1985
  • Publisher: IWF (Göttingen)
  • Language: English
13:17 IWF (Göttingen) German 1985

Aktivator-Inhibitor - Ein Modell zur biologischen Musterbildung

Das mathematische Modell wird in Computersimulationen interpretiert, wobei sich die verschiedenen Muster durch Variation der Parameter bilden: Anstoßen durch statistische Schwankungen, verschiedene Regenerationsabläufe, spezifische und unspezifische Induktionen, oszillierende Muster und Ausrichtungen, periodische Muster sowie regelmäßige Muster während des Wachstums.
  • Published: 1985
  • Publisher: IWF (Göttingen)
  • Language: German
01:53 Universität Bayreuth (UBT), Macromolecular Chemistry II No linguistic content; Not applicable 2013

Functionalization of gold nanoparticles in two-phase system

The short video shows the well-established method of ligand-exchange, which is used for the introduction of ligands to nanoparticles in one-phase and two-phase systems. Here is shown ligand exchange of citric acid ligands on gold nanoparticles against vinyl-pyridine functionalized polystyrene.
  • Published: 2013
  • Publisher: Universität Bayreuth (UBT), Macromolecular Chemistry II
  • Language: No linguistic content; Not applicable
03:55 IWF (Göttingen) Silent film 1972

Kristallumwandlung - Temperaturgesteuerte Strukturveränderung in Vanadiumdioxid-Einkristallen

At a critical temperature of 65,5°C, vanadium oxide crystals exhibit a structural transformation which is associated with a semiconductor-to-metal transition. The double-refractive, low-temperature phase is split up into differently oriented domains which can be rendered visible under a polarization microscope. Filmed through such a microscope, the film shows the transitions between semiconducting and metallic phases of vanadium oxide monocrystal needles. The transformations are caused by the external application of heat or by current flow with defined angles resulting between the domain walls and the crystal axes. In the case of current passing through the crystals there are, in addition, domain migrations which are due to the Peltier Effect and depend upon the direction of the current flow.
  • Published: 1972
  • Publisher: IWF (Göttingen)
  • Language: Silent film
08:23 IWF (Göttingen) Silent film 1970

Umwandlung des Zinns - Fortschreiten der Umwandlungsfront

Transformation of white into grey tin at experiment temperatures of approx. -25°C and reconversion at approx. +20°C. Formation of the transformation front. Demonstration of the deformations, which result during the growth of grey or white tin. Front form along one grain boundary. With time-lapse.
  • Published: 1970
  • Publisher: IWF (Göttingen)
  • Language: Silent film
21:26 IWF (Göttingen) German 1984

Chromatographie - 1. Trennmethoden in Theorie und Praxis

Chromatographische Trennung: Farbstoffgemische in der Dünnschicht- und Flüssigkeitssäulenchromatographie (Zeitraffung). Funktion der stationären und mobilen Phase. Gaschromatographie. Moderne Gerätetechnik: Scanner, Plotter, Integratoren und Drucker. Adsorption und Verteilungsgleichgewicht in Experiment und Modelltrick: kinetisches Modell, Trennstufenmodell, Ionenaustausch, Gelchromatographie, Umkehrphasen, Trennstufenzahl und -höhe, Durchflußgeschwindigkeit, Retentionszeit und Trennleistung: Van-Deemter-Kurve.
  • Published: 1984
  • Publisher: IWF (Göttingen)
  • Language: German
06:01 IWF (Göttingen) German 1976

Schwingungen von Molekülen im Kristallgitter - Melamin mit Wasserstoffbrücken

Translations- und Torsionsschwingungen der Moleküle. Am Beispiel des Melamins werden die elastischen Eigenschaften der zwischenmolekularen Wasserstoffbrücken-Bindungen demonstriert. Anhand der thermisch bei 60 und 300 K angeregten Gitterschwingungen wird verdeutlicht, daß sie der mechanische Speicher der spezifischen Wärme des Melamin-Kristalls sind.
  • Published: 1976
  • Publisher: IWF (Göttingen)
  • Language: German
06:13 IWF (Göttingen) English 1976

Vibrations of Free Molecules - 2. Forms of Vibration of the Methyl Group in Propene

The movement of the atoms during the more important normal vibrations of propene are shown in perspective representation: the stretching vibrations of the C=C double bond and the stretching and bending vibrations of the CH[3]-group. The in-phase and out-of-phase movements as well as the concept of characteristic vibrations become clear in the process.
  • Published: 1976
  • Publisher: IWF (Göttingen)
  • Language: English
15:08 IWF (Göttingen) German 1985

Chromatographie - 2. Analysentechniken

Gerätetechnische Demonstration dreier verschiedener moderner chromatographischer Verfahren. 1. Dünnschichtchromatographie: Anwendung von Nanoliter-Kapillaren; Probennehmer und Auftragsautomat; Flachboden-, Sandwich-, Linearentwicklungs-, Antizirkular-Kammer; Sprühentwicklung; Tauchkammer; Photometer-Scanner; Plotter; Integrator; Drucker. 2. Hochleistungs-Flüssigkeits-Chromatographie: Säulen; Reaktionsdetektor. 3. Gaschromatographie: Trennsäulen und Trennkapillaren; Ionisationsdetektor.
  • Published: 1985
  • Publisher: IWF (Göttingen)
  • Language: German
04:34 IWF (Göttingen) English 1985

Chromatography - 4. Packing of a Liquid Chromatograph (LC) Separation Column

Each of the steps involved in the homogenous packing of a separation column with silica gel as a stationary phase for low pressure-hypotension liqiuid chromatography is described. A dye mix is used to test the quality, or efficiency, of separation of the column. This is done by comparing the column with columns which have already been completely separated.
  • Published: 1985
  • Publisher: IWF (Göttingen)
  • Language: English
03:45 IWF (Göttingen) German 1982

Diffusion in Abhängigkeit vom Molekulargewicht am Beispiel verschiedener Farbstoffe

The dyes chrysoidin (mol. wt. 249), orange G (452), acid fuchsin (586), light green (793) diffuse through 10% gelatine columns. The diffusion velocity decreases with increasing molecular weight and continuous experimental duration (8 days at room temperature).
  • Published: 1982
  • Publisher: IWF (Göttingen)
  • Language: German
06:49 IWF (Göttingen) English 1976

Vibrations of Free Molecules - 1. Stretching and Deformation Vibrations of Ethylene

The movements of the atoms during the more important normal vibrations of ethylene are shown: the stretching vibrations of the C=C double bond and the stretching and bending vibrations of the CH[2]-groups. The in-phase and out-of-phase movements as well as the concept of characteristic vibrations become clear in the process.
  • Published: 1976
  • Publisher: IWF (Göttingen)
  • Language: English
03:48 IWF (Göttingen) English 1976

Vibrations of Free Molecules - 3. Forms of Vibration of Aromatic Rings in Melamin

The movement of the atoms during the more important normal vibrations of melamine are shown in perspective representation: stretching and bending vibrations of the aromatic ring in the melamine molecule. The in-phase and out-of-phase movements as well as the concept of characteristic vibrations become clear in the process.
  • Published: 1976
  • Publisher: IWF (Göttingen)
  • Language: English
04:28 IWF (Göttingen) German 1985

Chromatographie - 4. Packen einer flüssigkeitschromatographischen Trennsäule

In der Niederdruck-Flüssigkeitschromatographie werden handelsübliche oder selbstgepackte Trennsäulen benutzt. Deren Trennleistung hängt von der Qualität der Säulenpackung ab. Demonstration einzelner Fertigungsschritte: Einfüllen von Kieselgel und Lösungsmittel; Verdichtung der Packung; Test mit Farbstoffmischung; Zonenbildung als Qualitätstest.
  • Published: 1985
  • Publisher: IWF (Göttingen)
  • Language: German
07:42 IWF (Göttingen) Silent film 1967

Rostbildung auf Reineisen - Anfangsstadien

The film shows the initial stages of rust formation on a polished surface of pure iron at microscopic magnifications. The experiments were made in an atmosphere of 75 per cent relative humidity with small additions of hydrochlorid acid acting to accelerate corrosion. Using the fast motion technique it is possible to observe the individual stages of rust formation: First, corrosion points occur which, as corrosion proceeds further, grow into filament-type shapes spreading all over the iron surface. In some instances, the dependence of the direction of filament growth on the polishing direction can be observed. Also, scratches on the metal surface display a greater affinity to corrosion in some places.
  • Published: 1967
  • Publisher: IWF (Göttingen)
  • Language: Silent film
17:21 IWF (Göttingen) English 1983

Evaporation of Crystals - Evaporation of Germanium-mono-sulfide Cleavage Plane

With the interference-contrast-microscope it is possible to observe low steps which occur on a GeS-cleavage face during evaporation. The surface evaporates at locations where the crystal structure is disturbed: at the cleavage steps and at distinct dislocations. At first the cleavage steps are completely evaporated if they are not oxidized. Subsequently terraced pits are formed. Steps spread from the center of the pits over the surface homogeneously. The origins of the steps are locally fixed (at dislocations) or appear at random locations when the steps are formed by dislocation loops or by stacking faults. The shape of the pits is rhombic at low temperatures and oval at high temperatures. In addition, rectangular pits randomly appear at different locations at high temperatures. With increasing temperature stationary rhombic step patterns appear temporarily dendritic. Herringbones are formed by intersecting steps of different stationary centers. Precipitated impurities (GeS[2]) affect the spreading steps if the surface deviates from the ideal cleavage plane. Many details of the step patterns are explained by still pictures which show chemically etched examples. A ball model and an animation illustrate the relation between evaporation patterns and the crystal structure.
  • Published: 1983
  • Publisher: IWF (Göttingen)
  • Language: English
17:25 IWF (Göttingen) German 1983

Kristallverdampfung - Verdampfung der Germaniummonosulfid-Spaltfläche

Germaniummonosulfid-Verdampfung zwischen 660 und 800 K an ebenen Spaltflächen im Auflicht-Interferenzkontrast in Heizkammer mit Argon-Schutzgas. Probendicke 0,5 bis 1 mm. Mikro- und REM-Aufnahmen. Kristallgitterabbau im Modell und Zeichentrick: kovalente Bindungen, Stufen- und Schraubenversetzungen, Halbkristallagen. Verdampfungsmuster: rhombisch und dendritisch. Bildung von Grübchen und Inseln. Ausscheidung von Germaniumdisulfid.
  • Published: 1983
  • Publisher: IWF (Göttingen)
  • Language: German
External Website TU Clausthal Original sound, no spoken text 2000

Der DNA auf der Spur - Analyse per Enzym und Voltammetrie

Bericht über ein neues Analysverfahren
  • Published: 2000
  • Publisher: TU Clausthal
  • Language: Original sound, no spoken text
08:37 IWF (Göttingen) English 1983

The Zhabotinsky Reaction as a Model of Pattern Formation

Dissipative patterns form in originally simple chemical compounds. Starting from pacesetting centers, chemicalwaves of a redox reaction are transmitted. This can be seen in the change in color of a redox catalyst. The decarboxylation of malonic acid drives the total reaction. Pattern formation in the aggregation of Dictyostelium proceeds analagously (film/photos in cooperation with G. Gerisch, 1963).
  • Published: 1983
  • Publisher: IWF (Göttingen)
  • Language: English
03:58 IWF (Göttingen) English 1983

The Briggs-Rauscher Reaction as a Model of a Chemical Clock

Chemical oscillation reactions are made visible by the periodic appearance and disappearance of an iodine-starch complex. The oscillation is based on autocatalytic reactions, in which intermediary compounds are oxidized and reduced in rhythmic sequence. The total reaction is driven by the decarboxylation of malonic acid. With time-lapse.
  • Published: 1983
  • Publisher: IWF (Göttingen)
  • Language: English
04:51 IWF (Göttingen) German 1982

Der Einfluß des Ionenmilieus auf die Quellung von Agar

Preparation of Hofmeister's lyotropic series of cations (Li, Na, K, Rb, Cs) and anions (Cl, Br, J). Due to the agar's negative charge, its degree of imbibitional swelling decreases with increasing ionic radius of the cations and with increasing ionic radius of the anions.
  • Published: 1982
  • Publisher: IWF (Göttingen)
  • Language: German
04:31 IWF (Göttingen) German 1982

Traubesche Zelle

Formation of a Traube Cell is followed in time-lapse photography starting from a crystal of potassium hexacyanoferrate II in a 4% copper sulphate solution through its development until the destruction of the semipermeable deposit membrane and reversal of the cell.
  • Published: 1982
  • Publisher: IWF (Göttingen)
  • Language: German
09:20 IWF (Göttingen) Silent film 1960

Verdampfungsvorgang bei selbsttätigem Umlauf in senkrechten Rohren

Experimental apparatus. Evaporation processes in different steam pipes made of glass, copper, and steel. Natural circulation of different evaporating fluids (water, sugar solution). Demonstration of the processes in the preheating zone and the sparkling zone. With slow motion.
  • Published: 1960
  • Publisher: IWF (Göttingen)
  • Language: Silent film
04:01 IWF (Göttingen) German 1985

Titration

Determination of the acidity of a solution using normal (molar) NaOH. Burette with Kjeldahl lines, cleaning, greasing the stopcock. Filling it with adjusted normal solution; adding indicator. Neutral point, colour change of phenolphthalein in basic, neutral and acidic solutions.
  • Published: 1985
  • Publisher: IWF (Göttingen)
  • Language: German
06:12 IWF (Göttingen) German 1976

Schwingungen freier Moleküle - 2. Schwingungsformen der Methylgruppe in Propen

Bewegungen der Atome bei den wichtigsten Normalschwingungen des Propens: Valenz-Schwingungen der C=C-Doppelbindung, die Valenz- und Deformationsschwingungen der CH[3]-Gruppe. Gleichtakt- und Gegentakt-Bewegungen sowie das Konzept der charakteristischen Schwingungen werden dabei deutlich.
  • Published: 1976
  • Publisher: IWF (Göttingen)
  • Language: German
03:47 IWF (Göttingen) German 1976

Schwingungen freier Moleküle - 3. Schwingungsformen aromatischer Ringe in Melamin

Bewegungen der Atome bei den wichtigsten Normalschwingungen des Melamins: Valenz- und Deformationsschwingungen des aromatischen Ringes im Melamin-Molekül, Gleichtakt- und Gegentakt-Bewegungen sowie das Konzept der charakteristischen Schwingungen werden dabei deutlich.
  • Published: 1976
  • Publisher: IWF (Göttingen)
  • Language: German
06:48 IWF (Göttingen) German 1976

Schwingungen freier Moleküle - 1. Valenz- und Deformationsschwingungen in Äthylen

Bewegungen der Atome bei den wichtigsten Normalschwingungen des Äthylens: Valenz-Schwingungen der C=C-Doppelbindung, die Valenz- und Deformationsschwingungen der CH[2]-Gruppen. Gleichtakt- und Gegentakt-Bewegungen sowie das Konzept der charakteristischen Schwingungen werden dabei deutlich.
  • Published: 1976
  • Publisher: IWF (Göttingen)
  • Language: German
01:41 IWF (Göttingen) German 2004

Interpretation der Elektronendichte - beta-Faltblatt

The video clip shows the electron density measuring of a simple protein - the lysozyme from egg white - visualized by means of a special software (XTAL View).
  • Published: 2004
  • Publisher: IWF (Göttingen)
  • Language: German
11:51 IWF (Göttingen) English 1991

Friedrich Hund: Reminiscences of Robert S. Mulliken, Göttingen 1988

The inaugurative Robert S. Mulliken-Lecture at the University of Chicago, 1988. Parallels between the biographies of Mulliken and Hund, early research, personal and scientific contact since Mullikens Göttingen days in 1927. The early days of molecular spectroscopy: Mullikens experimental approach and Hunds theoretical. Their meeting in the USA in 1929 and their "Agreement about representing molecular states". Reminiscences of their meeting in Heidelberg 1930. (With personal photos.)
  • Published: 1991
  • Publisher: IWF (Göttingen)
  • Language: English
05:24 König, Burkhard German 2014

Isolierung von Piperin aus schwarzem Pfeffer

Versuch 1022: Isolierung von Piperin aus schwarzem Pfeffer
  • Published: 2014
  • Publisher: König, Burkhard
  • Language: German
05:04 König, Burkhard German 2014

Oxidation von Anthracen zu Anthrachinon mit Kaliumpermanganat

Versuch 5026: Oxidation von Anthracen zu Anthrachinon mit Kaliumpermanganat
  • Published: 2014
  • Publisher: König, Burkhard
  • Language: German
05:10 König, Burkhard German 2014

H2O-Eliminierung aus 4-Hydroxy-4-methyl-2-pentanon

Versuch 1024: Eliminierung von Wasser aus 4-Hydroxy-4-methyl-2-pentanon
  • Published: 2014
  • Publisher: König, Burkhard
  • Language: German
05:44 König, Burkhard German 2014

Oxidation von Anthracen zu Anthrachinon mit Ammoniumcer(IV)-nitrat

Versuch 3021: Oxidation von Anthracen zu Anthrachinon mit Ammoniumcer(IV)-nitrat
  • Published: 2014
  • Publisher: König, Burkhard
  • Language: German
01:41 König, Burkhard No linguistic content; Not applicable 2014

Teaser zu den NOP-Videos

  • Published: 2014
  • Publisher: König, Burkhard
  • Language: No linguistic content; Not applicable
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