Biologia

Detección de la acomodación con un optómetro

Principle

When looking through a slide with two very small holes located very close together (optometer aperture), in the absence of accommodation relative to their distance, objects close to the eye appear to be relatively well focussed except that there appear to be two of ...

Combinación sojetiva de colores

Principle

If a circular disc separated into various differently coloured sectors is rotated by a motor so fast that the eye can no longer distinguish the colours, a mixed colour is then perceived. By varying the composition and size of the sectors, it is possible to give the impression of any ...

Electronistamografía con Cobra4

Principle

Electronystagmography (ENG) is an electrophysiological diagnostic procedure for measuring the movement of the eyes. Several electrodes measure the potential differences that are caused by the eye movements. When looking at a moving, regular, repetitive pattern (e.g. the wagons of ...

Spectroscopic identification of sodium, potassium, and cal cium in plant ashes

Principle

The content of plant ash is investigated to investigate the mineral content of plants. The characteristic lines of the elements are determined using a small spectroscope. The cations of sodium, potassium and calcium are detected qualitatively.

Microorganismos del suelo

Limpieza del agua por filtración via carbón activo

Principle

Active carbon is a good absorbent and as such is excellent when used as a filter. During water treatment, for example, active carbon filters are used to remove pesticides and detergents (soap and washing-up liquid). The cleansing of water can be demonstrated impressively by ...

Contaminación del aire por combustión de residuos salvaje

Descomposición de celulosa

Influencia de la temperatura sobre precesos microbianos de descomposición

Efecto de aceite mineral o salsobre la descomposición de ce- lulosas

Descomposición de sustancias orgánicas en el agua

Descomposición microbiana de aceite mineral

Efecto de la temperatura sobre la germinación y el creci- miento del berro

Eight petri dishes are filled nearly to the brim with finely sieved, moist garden soil and 50 cress seeds are planted in each one. They are then placed inside a device which keeps each of the samples at a different temperature, whereby they are evenly distributed between cold and warm regions. ...

Efecto de iones de metal pesados sobre la actividad de los encimas

Calidad del auga - contaminación con metales pesados

Principle

Heavy-metal ions may be carried into surface or ground water from mining fields or via the waste water of galvanicor similar production sites. They block the effect of enzymes so that the processes in the metabolism of the organisms that are controlled by these enzymes may be ...