Publications by authors named "J Trippel"

2 Publications

  • Page 1 of 1

Improving aeration systems in saline water (part II): effect of different salts and diffuser type on oxygen transfer of fine-bubble aeration systems.

Water Sci Technol 2021 Jun;83(11):2778-2792

Technical University of Darmstadt, Institut IWAR, Franziska-Braun-Str. 7, 64287 Darmstadt, Germany E-mail:

The objective of the present study is to investigate the different effects on the oxygen transfer of fine-bubble aeration systems in saline water. Compared to tap water, oxygen transfer increases due to the inhibition of bubble coalescence. In Part I of the present study, we investigated in laboratory-scale experiments the effect of design of diffuser membrane. The objective of Part II is the assessment of effects of different salts, diffuser type and diffuser density. We measured the concentration of various salts (MgCl; CaCl; NaSO; NaCl; KCl) above which coalescence is fully inhibited and oxygen transfer reaches its maximum (referred to as the critical coalescence concentration; CCC). For this purpose, we developed a new analytical approach, which enables investigation of the coalescence behaviour of any aeration system and (mixed) salt solution quickly and easily by evaluating the results of oxygen transfer tests. To investigate the transferability to large scale and the effect of diffuser type and density, we repeated lab-scale experiments in a 17,100 L pilot-scale test tank and carried out additional tests with tube and plate diffusers at different diffuser densities. The results show that despite the higher pressure drop, diffusers with dense slit density and smaller slits are to be recommended in order to improve efficiency of aeration systems in saline water.
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http://dx.doi.org/10.2166/wst.2021.185DOI Listing
June 2021

Stereological study of the zona fasciculata of the adrenal cortex in stress situations (hypothermia, catabolism).

Pathol Res Pract 1978 Aug;162(4):380-97

The ultrastructure of the rat fasciculata cells in stress situations, such as catabolism and hypothermia was compared descriptively and quantitatively by stereological methods with that of the nonstimulated rat fasciculata cell. The volume and surface densities are expressed per cm3 of cytoplasm, mitochondria and smooth endoplasmic reticulum. Furthermore, absolute values are given. In both stress situations the volume density of the mitochondria compared to the controls is enlarged significantly (H: 37% CA: 50%). The significant increase of the average single mitochondrium of the fasciculata cell (H: 58% CA: 58%) shows a real growth of the mitochondria in these stress situations. Also the surface density of the mitochondrial inner membranes--the mitochondrial enzymes for steroid genesis are partly located in these membranes--shows a significant increase (H: 31%, CA: 84%). Whereas the volume density of the smooth endoplasmic reticulum remains unchanged, the surface density is significantly raised (H: 44%, CA: 60%). An attempt was made to draw up a relationship between stereological and known biochemical data of steroid genesis within the fasciculata cell. An activation in both stress situations could be observed. The stereological data reflect a subcellular reaction pattern, which is similar to exogenous ACTH administration, thus indicating an endogenous ACTH liberation due to these stress conditions.
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http://dx.doi.org/10.1016/S0344-0338(78)80069-7DOI Listing
August 1978
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