Characterization of Chironomidae (Diptera) surface-floating pupal exuviae sample sort time from coastal tropical aquatic systems

2015 ◽  
Vol 187 (3) ◽  
Author(s):  
Petra Kranzfelder ◽  
Leonard C. Ferrington
Keyword(s):  
Aquatic Systems ◽  
Pupal Exuviae ◽  
Sample Sort

scholarly journals Challenges in characterizing the environmental fate and effects of carbon nanotubes and inorganic nanomaterials in aquatic systems

2018 ◽  
Vol 5 (1) ◽  
pp. 48-63 ◽  
Author(s):  
Peter Laux ◽  
Christian Riebeling ◽  
Andy M. Booth ◽  
Joseph D. Brain ◽  
Josephine Brunner ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Surface Area ◽  
Environmental Fate ◽  
Aquatic Systems ◽  
Inorganic Nanomaterials

Characterization of carbon nanotube dispersions requires measurement of both, concentration and surface area.

scholarly journals Recent advances in the study of mercury methylation in aquatic systems

FACETS ◽  
2017 ◽  
Vol 2 (1) ◽  
pp. 85-119 ◽  
Author(s):  
Avnee R. Paranjape ◽  
Britt D. Hall
Keyword(s):  
Climate Change ◽  
Stable Isotopes ◽  
Abiotic Factors ◽  
Biogeochemical Cycles ◽  
Aquatic Systems ◽  
Anthropogenic Activity ◽  
Mercury Methylation ◽  
Aquatic Environments ◽  
Direct Effects

With increasing input of neurotoxic mercury to environments as a result of anthropogenic activity, it has become imperative to examine how mercury may enter biotic systems through its methylation to bioavailable forms in aquatic environments. Recent development of stable isotope-based methods in methylation studies has enabled a better understanding of the factors controlling methylation in aquatic systems. In addition, the identification and tracking of the hgcAB gene cluster, which is necessary for methylation, has broadened the range of known methylators and methylation-conducive environments. Study of abiotic factors in methylation with new molecular methods (the use of stable isotopes and genomic methods) has helped elucidate the confounding influences of many environmental factors, as these methods enable the examination of their direct effects instead of merely correlative observations. Such developments will be helpful in the finer characterization of mercury biogeochemical cycles, which will enable better predictions of the potential effects of climate change on mercury methylation in aquatic systems and, by extension, the threat this may pose to biota.

Characterization of biogenic organic matter (BOM)

1998 ◽  
Vol 37 (2) ◽  
pp. 97-103 ◽  
Author(s):  
Fritz H. Frimmel ◽  
Jutta Jahnel ◽  
Sebastian Hesse
Keyword(s):  
Organic Matter ◽  
Hydrological Cycle ◽  
Complex Structure ◽  
Aquatic Systems ◽  
Refractory Part ◽  
Analytical Characterization ◽  
Small Variety ◽  
Water Constituents

Biogenic organic matter (BOM) is of ubiquitous relevance in all aquatic systems. This is due to the fundamental function of the natural organic matter in combination with the microbial activity which guarantees the degradation in and the self purification of water in the hydrological cycle. In addition, the refractory part of the widely distributed BOM acts as effective adsorbent for most water constituents, and in case of mobile fractions as active vehicle for pollutants. In contrast to the broad importance of the occurrence and role of BOM, there is a fairly small variety for its analytical characterization. Especially in the field of in-situ measurements and of the determination in the original concentration range of aqueous samples, relatively little data have been collected. This is partly due to the complex structure of BOM, partly to the limited availability of analytical methods suited for that type of investigations. The aim of the paper is to give typical examples for the a) physical/chemical, b) microbiological and c) technologically orientated methods of the analytical characterization of BOM in aqueous solution and to draw conclusions on the function of BOM in aquatic systems and their use for man.

Morphological Characterization of Mycobacteriophage R1

1974 ◽  
Vol 32 ◽  
pp. 254-255
Author(s):  
B. L. Soloff ◽  
T. A. Rado
Keyword(s):  
Carbon Source ◽  
Stationary Phase ◽  
Growth Phase ◽  
Minimal Medium ◽  
Morphological Characterization ◽  
Logarithmic Growth Phase ◽  
Complete Lysis ◽  
Lysogenic Culture ◽  
Logarithmic Growth

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.

AEM analysis of crystallization in Ti-based amorphous alloys

1983 ◽  
Vol 41 ◽  
pp. 270-271
Author(s):  
A.R. Pelton ◽  
A.F. Marshall ◽  
Y.S. Lee
Keyword(s):  
Magnetic Properties ◽  
Amorphous Alloys ◽  
Amorphous Materials ◽  
Isothermal Annealing ◽  
Amorphous Matrix ◽  
Nucleation And Growth ◽  
Current Interest ◽  
Amorphous Films ◽  
Electrical And Magnetic Properties

Amorphous materials are of current interest due to their desirable mechanical, electrical and magnetic properties. Furthermore, crystallizing amorphous alloys provides an avenue for discerning sequential and competitive phases thus allowing access to otherwise inaccessible crystalline structures. Previous studies have shown the benefits of using AEM to determine crystal structures and compositions of partially crystallized alloys. The present paper will discuss the AEM characterization of crystallized Cu-Ti and Ni-Ti amorphous films.Cu60Ti40: The amorphous alloy Cu60Ti40, when continuously heated, forms a simple intermediate, macrocrystalline phase which then transforms to the ordered, equilibrium Cu3Ti2 phase. However, contrary to what one would expect from kinetic considerations, isothermal annealing below the isochronal crystallization temperature results in direct nucleation and growth of Cu3Ti2 from the amorphous matrix.

Characterization of Coherent, Ordered Precipitates in Nickel-Base Alloys

1973 ◽  
Vol 31 ◽  
pp. 144-145
Author(s):  
B. H. Kear ◽  
J. M. Oblak
Keyword(s):  
Stable Phase ◽  
Nickel Base Superalloy ◽  
Alloy 718 ◽  
Commercial Alloy ◽  
Precipitate Morphology ◽  
Continuous Precipitation ◽  
Nickel Base ◽  
Base Superalloy ◽  
Strengthening Precipitate

A nickel-base superalloy is essentially a Ni/Cr solid solution hardened by additions of Al (Ti, Nb, etc.) to precipitate a coherent, ordered phase. In most commercial alloy systems, e.g. B-1900, IN-100 and Mar-M200, the stable precipitate is Ni3 (Al,Ti) γ′, with an LI2structure. In A lloy 901 the normal precipitate is metastable Nis Ti3 γ′ ; the stable phase is a hexagonal Do2 4 structure. In Alloy 718 the strengthening precipitate is metastable γ″, which has a body-centered tetragonal D022 structure.Precipitate MorphologyIn most systems the ordered γ′ phase forms by a continuous precipitation re-action, which gives rise to a uniform intragranular dispersion of precipitate particles. For zero γ/γ′ misfit, the γ′ precipitates assume a spheroidal.

Sign in / Sign up

Export Citation Format

Share Document