Lec 19 | MIT 7.014 Introductory Biology, Spring 2005 Regulation of Productivity (Prof. Penny Chisholm) View the complete course: ocw.mit.edu License: Creative Commons BY-NC-SA More information at ocw.mit.edu More courses at ocw.mit.edu
Diatoms in darkfield This is a sample of a single drop of river water. The majority of the creatures you can see are diatoms; beautiful single-celled organisms encased in a frustule, a porous external layer composed almost purely of silica. The magnification here is between 40X and 200X. The shimmering effect is due to the video sensor struggling with the low level of light. In reality, the diatoms appear pin-sharp and full of colour against the pitch black background
why is kaolin good in paper filling than baryte Gemme Nano Tech: joyal: AAPG Datapages/Archives: Cements and In: Kaolin processing, plant, machine, Kaolin processing plant: Barytes,Barium Sulfate,Barite Mineral,Barytes Powder,Barite: Foshan Shunde Yufeng Powder Material Co., Ltd.: These photomicrographs of glass beads in polyamide demonstrate the effectiveness of silane treatment in providing intimate filler-matrix contact. In addition to facilitating stress transfer, this minimizes or eliminates voids at the filler-matrix interface where moisture or gases can penetrate. Floated 325 mesh feldspar finds limited use as a filler in polymers despite its low vehicle demand, and resistance to abrasion and chemical degradation. Although the performance properties of feldspar and nepheline syenite are similar, the latter is more often used because it is available in a broader range of fine grinds (325 mesh to mesh) and it has generally higher brightness . The equipment used for particle size ***ysis, whether based on principles of x-ray sedimentation, light scattering, light extinction or electrical resistance/volume displacement, match the behavior of a particle, regardless of shape, to that of an ideal sphere of specific diameter. Particle size is Of the ingredients used to modify the properties of rubber and ...
Eunotia or Cymbella diatom This is a banana-shaped diatom (Eunotia). It is very common in my water samples containing masses of filamentous algae. This video shows detail of shape and small notches in its frustule. 800x
Eunotia or Cymbella diatom at 400x This is a video of a banana-shaped Eunotia or Cymbella diatom viewed close-up at 400x. This video shows detail of the frustule.
Diatoms in action Diatoms are unicellular algae. They have beautiful ornate cell walls made of silica. Basically they live in glass houses! How they move is not fully understood. I filmed these through the SP100 microscope using a handheld Canon Powershot A720 IS at 6X zoom. The magnification was between 100X and 600X
Frontonia leucas feeding Frontonia browsing algae. Oblique illumination (accomplished by tilting the objective slightly) helps show prominent features, such as the distinctive contractile vacuole with "radiating c***s." At one point, it swallows an empty diatom frustule, but excretes it a few minutes later. 400x
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Particles moving inside diatom frustule Probably bits of decaying diatom, being knocked about by Brownian motion Thanks, PsiWavefunction! (Check out her superb protistology blog: ) From a jar of pond water that was allowed to stagnate for the purpose of observing pond bacteria. Magnification 1000x
Long diatom (Synedra) This is another video in a collection of diatoms found in a single petri dish. This is a long diatom, probably of the genus Synedra. These are common in my water samples, although it is more common to see them grouped together in long chains.
Another Diatom I need some help here. Since I'm not a diatom dichotomous key, I need someone to help me identify this diatom. There are many more out there. can anyone tell me what species this is?
Diatoms. Part 3: Observation of diatoms The video "Diatoms" is composed of three parts. Part 3. Diatom species that vary with changing water quality are shown under the microscope(5 min 37sec) Diatom Project web page www.u-gakugei.ac.jp
Diatom Microscopic Life Under Microscope A Diatom microorganism under my microscope twitching. The silica cell wall and the dividing line in the middle. This specimen came from a puddle in my back yard. Diatoms are a major group of algae, and are one of the most common types of phytoplankton. Most diatoms are unicellular, although they can exist as colonies in the shape of filaments or ribbons (eg Fragilaria), fans (eg Meridion), zigzags (eg Tabellaria), or stellate colonies (eg Asterionella). Diatoms are producers within the food chain. A characteristic feature of diatom cells is that they are encased within a unique cell wall made of silica (hydrated silicon dioxide) called a frustule. These frustules show a wide diversity in form, but usually consist of two asymmetrical sides with a split between them, hence the group name. Fossil evidence suggests that they originated during, or before, the early Jurassic Period. Diatom communities are a popular tool for monitoring environmental conditions, past and present, and are commonly used in studies of water quality. Some diatoms are capable of movement via flagellation.