Thursday, 22 February 2018

About Polarization

Utilizing the polarization method in light microscopy reveals a specific kind of information about the sample. Applying this contrast method, we less often talk about structure size and shape, resolution power or even a specific staining. In case of transparent samples, polarization contrast in first instance has one subject in mind: the potential BIREFRINGENCE of the sample and its implications on a structural insight.

BIREFRINGENCE is a widespread phenomenon, found in nature as well as in man-made materials. Starch grains, fibers, crystals and minerals, plastic sheets and die cast components, the structural basis is always the same: embedded within an amorphous matrix, structures with an intrinsic geometric pattern cause an impact on the speed of light and its oscillating direction when sent through the sample.

Chemical cristals

Wednesday, 21 February 2018

A sponge a phoenix?

All sponges possess a remarkable ability to regenerate lost parts. A piece cut from the body of a sponge is capable of growing into a complete sponge. This power of regeneration helps the sponges to repair the damage caused in the harsh environment.

Wednesday, 7 February 2018

Transition of lava on Mount Etna

Limonite is a mineral consisting of various iron oxides. Limonite is yellow, ochre, brown or blackish colored by iron oxide.

Volcanic rock of Mount Etna can be transformed into Limonite, which is called like that because of its yellow brownish color. The Limonite is mainly produced by the oxidation of iron containing lava rocks by weathering, facilitated by splitting and pulverizing of the rock because of the penetration of the roots of vegetation enabling oxygen and humidity to enter.

Wednesday, 24 January 2018

Algae with an eye

Euglena species are often abundant in calm waters, where they can be present in such numbers, that the surface of ponds and ditches can have a green or red color.

Euglena is commonly studied in biology classes because it has both plant (it has chloroplasts and so can photosynthesize) and animal (it moves and can eat) characteristics. Depending on conditions, photosynthesis or eating can predominate. It is a single celled creature with a large flagellum (not visible in this video, see below) that lives in fresh water. It is generally elongate but can change its shape quite dramatically during so-called euglenoid movement. It swims using its flagellum and can orientate itself with respect to gravity and light.

Wednesday, 10 January 2018

Wood Collectors?

Wood Collectors primarily collect samples of plants from the group of seed plants, Spermatophytes. This can be either softwood (Gymnosperms) and hardwood (Angiosperms)

Wood however, is composed of various types of tissue, which wood collectors should be able to recognize and name in order to assign a particular species. Tissue which occurs abundantly in one species and is an important feature, can be completely absent in a different species. To see the right features, to name and describe them, is the most important for determination. The recognition of wood types can be done, among others, by the study of micro preparations.

Micro preparations of wood are thin slices of wood of 10-15 microns thick, cut into 3 planes:

a) In the transverse plane for example, the vessels, the distribution of vessels, the type and the distribution of the parenchyma (ground tissue), the number of rays per mm and the thickness of the fiber wall can be seen.