Grazing and the distribution of sediment particle sizes in artificial stream systems

Hydrobiologia ◽  
1993 ◽  
Vol 252 (2) ◽  
pp. 127-132 ◽  
Author(s):  
Thomas J. Gardner
Keyword(s):  
Particle Sizes ◽  
Sediment Particle ◽  
Artificial Stream ◽  
Stream Systems

Heavy metal indicator potential of the Asiatic clam (Corbicula fluminea) in artificial stream systems

Hydrobiologia ◽  
1983 ◽  
Vol 102 (2) ◽  
pp. 81-88 ◽  
Author(s):  
Robert L. Graney ◽  
Donald S. Cherry ◽  
John Cairns
Keyword(s):  
Heavy Metal ◽  
Corbicula Fluminea ◽  
Asiatic Clam ◽  
Artificial Stream ◽  
Clam Corbicula ◽  
Stream Systems

Artificial Streams for Environmental Effects Monitoring (EEM): Development and Application in Canada over the Past Decade

2002 ◽  
Vol 37 (1) ◽  
pp. 155-180 ◽  
Author(s):  
Monique G. Dubé ◽  
Joseph M. Culp ◽  
Kevin J. Cash ◽  
Nancy E. Glozier ◽  
Deborah L. MacLatchy ◽  
...  
Keyword(s):  
Environmental Effects ◽  
Research Effort ◽  
Pulp Mill ◽  
Benthic Invertebrate ◽  
Artificial Streams ◽  
The Past ◽  
Artificial Stream ◽  
Pulp Mill Effluents ◽  
Environmental Effects Monitoring ◽  
Stream Systems

Abstract Development of artificial stream systems has been an on-going research effort in Canada over the past decade. At the National Water Research Institute (NWRI) of Environment Canada, artificial stream systems have been developed to assess the effects of point source effluents on aquatic biota. Initial applications (1990–1994) focused on assessing the effects of pulp mill effluents on benthic invertebrate and algae communities in large western Canadian rivers. Artificial streams were then used to assess the effects of pulp mill effluents on fish in marine and estuarine environments in eastern Canada (1997–1999). Most recently (2000–2001) artificial stream systems have been developed as tools to evaluate the effects of mining effluents on fish and benthic invertebrates. In addition, multi-trophic level (algae + benthic invertebrate + fish) applications have been developed for cumulative effects bioassessment. Based upon this culmination of research and development, artificial stream systems have been incorporated into the federally legislated Environmental Effects Monitoring (EEM) program as an alternative to field surveys for assessment of pulp and paper and mining pollution. The Canadian experience in development of artificial stream systems should serve as a model to demonstrate how research tools can be incorporated into federally legislated monitoring programs.

Characterization of carbides in M50NiL

1991 ◽  
Vol 49 ◽  
pp. 606-607
Author(s):  
L. S. Lin ◽  
K. P. Gumz ◽  
A. V. Karg ◽  
C. C. Law
Keyword(s):  
Temperature Effects ◽  
Base Composition ◽  
Lattice Parameter ◽  
Control Surface ◽  
Carbide Formation ◽  
Particle Sizes ◽  
Low Carbon ◽  
Fee Structure ◽  
Heat Treated

Carbon and temperature effects on carbide formation in the carburized zone of M50NiL are of great importance because they can be used to control surface properties of bearings. A series of homogeneous alloys (with M50NiL as base composition) containing various levels of carbon in the range of 0.15% to 1.5% (in wt.%) and heat treated at temperatures between 650°C to 1100°C were selected for characterizations. Eleven samples were chosen for carbide characterization and chemical analysis and their identifications are listed in Table 1.Five different carbides consisting of M6C, M2C, M7C3 and M23C6 were found in all eleven samples examined as shown in Table 1. M6C carbides (with least carbon) were found to be the major carbide in low carbon alloys (<0.3% C) and their amounts decreased as the carbon content increased. In sample C (0.3% C), most particles (95%) encountered were M6C carbide with a particle sizes range between 0.05 to 0.25 um. The M6C carbide are enriched in both Mo and Fe and have a fee structure with lattice parameter a=1.105 nm (Figure 1).

TEM study on fine carbide precipitates and dislocation cell structure

1990 ◽  
Vol 48 (4) ◽  
pp. 904-905
Author(s):  
Mengzhe Chen ◽  
Siqin Wang ◽  
Jun Ke
Keyword(s):  
Carbide Particle ◽  
Cell Structure ◽  
Ferrite Matrix ◽  
Dislocation Cell ◽  
Isothermal Treatment ◽  
Particle Sizes ◽  
Dislocation Cell Structure ◽  
Thin Foils ◽  
Hsla Steels ◽  
Fine Carbide

A series of investigations have been conducted into the nature and origin of the dislocation cell structure. R.J.Klassen calculated that the dislocation cell limiting size in pure ferrite matrix is about 0.4 μm. M.N.Bassion estimated the size of dislocation cell in deformed ferrite of HSLA steels to be of the same order.In this paper, TEM observation has been concentrated on the interaction of fine carbide precipitates with dislocation cell structure in deformed Fe-C-V (0.05%C, 0.13% and 0.57%V) and Fe-C-Nb (0.07 %C and 0.04%Nb) alloys and compared with that in Fe-C (0.05%). Specimens were austenitized at 1500 “C/20 min and followed by isothermal treatment at 750 °C and 800 “C for 20, 40 and 120 minutes . The carbide particle sizes in these steels are from 9 to 86nm measured from carbon extraction replicas. Specimens for TEM were cut from differently deformed areas of tensile specimens deformed at room temperture. The thin foils were jet electropolished at -20 C in a solution of 10% perchloric acid and 90% ethanol. The TEM observation was carried out in JEM 100CX , EM420 at 100kv and JEM 2000FX at 200kv.

A High Resolution Study of Alumina Supported Iridium Catalysts

1980 ◽  
Vol 38 ◽  
pp. 202-203
Author(s):  
C. Stoeckert ◽  
B. Etherton ◽  
M. Beer ◽  
J. Gryder
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Metal Particles ◽  
Optical Transfer Function ◽  
Particle Sizes ◽  
Iridium Catalysts ◽  
Transmission Electron ◽  
Optical Transfer ◽  
Conventional Transmission Electron Microscope ◽  
Resolution Study

The interpretation of the activity of catalysts requires information about the sizes of the metal particles, since this has implications for the number of surface atoms available for reaction. To determine the particle dimensions we used a high resolution STEM1. Such an instrument with its simple optical transfer function is far more suitable than a conventional transmission electron microscope for the establishment of particle sizes. We report here our study on the size and number distribution of Ir particles supported on Al2O3 and also examine simple geometric models for the shape of Ir particles.

Separation of Plasminogen Activators from Human Uterine Tissue and a Comparison with Activators from Human Urine and Porcine Tissue

1979 ◽  
Vol 41 (04) ◽  
pp. 718-733 ◽  
Author(s):  
Preben Kok
Keyword(s):  
Plasminogen Activator ◽  
Human Urine ◽  
Gel Filtration ◽  
Ammonium Thiocyanate ◽  
Plasminogen Activators ◽  
Particle Sizes ◽  
Uterine Tissue ◽  
Porcine Tissue ◽  
Major Activity ◽  
Proliferative Phase

SummaryThree types of plasminogen activator could be distinguished in extracts from human uterine tissue. The activators differed in thermostability or in mode of inhibition by EACA.All the extracts contained stable as well as labile activators. The saline extracts were uniformly inhibited by increasing concentrations of EACA. Extracts made with 2 M ammonium thiocyanate were either uniformly inhibited by EACA or showed deflections indicating contamination with an activator, which was inhibited in a biphasic manner. It was possible to distinguish between: (1) An activator, abundantly present in the tissue, which was uniformly inhibited and stable. (2) Another uniformly inhibited activator, which was labile. (3) An activator, inhibited in a biphasic manner, similar to urokinase, which was present in varying amounts in uteri with the endometrium in the proliferative phase.Gel filtration of the uterine extracts showed two major activity peaks corresponding to particle sizes of 60,000 dalton and about 10,000 dalton.Antiserum to purified plasminogen activator, prepared from porcine ovaries, inhibited the activity of the human uterine extracts, but not the activities of human urokinase or urine. Urokinase antiserum in a concentration completely inhibiting human urine or urokinase, inhibited only 10% or less of the activities of human uterine extracts.

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