scholarly journals Testing the capabilities of the Mars Organic Molecule Analyser (MOMA) chromatographic columns for the separation of organic compounds on Mars

2020 ◽  
Vol 186 ◽  
pp. 104903
Author(s):  
Melissa Guzman ◽  
Cyril Szopa ◽  
Caroline Freissinet ◽  
Arnaud Buch ◽  
Fabien Stalport ◽  
...  
Author(s):  
Yating Chen ◽  
Bo Wang ◽  
yunxiang Lei ◽  
Yun-Bing Zhou ◽  
Yang Guo ◽  
...  

Although nearly one-third of organic compounds have polymorphism, more than three polymorphs with definite crystalline structures in an organic molecule are very rare. Herein, an aggregation-induced-emission-active isoquinoline derivative containing ethyl...


2008 ◽  
Vol 58 (10) ◽  
pp. 1955-1961 ◽  
Author(s):  
Elizabeth Arkhangelsky ◽  
Inna Levitsky ◽  
Vitaly Gitis

Studies of electrostatic repulsion in ultrafiltration membranes are limited to applications of different organic compounds carrying a set of unique characteristics, or to changes of general water parameters such as ionic strength and pH. The proposed method of deliberate alteration of surface charge of organic molecule by succinylation or by guanidination provides an opportunity to selectively investigate the electrostatic mechanism without changing size or hydrophobic properties of investigated molecule. The approach was successfully implemented on BSA protein, and new inside into the mechanism of electrostatic mechanism was obtained. The electrostatic repulsion becomes important when zeta potential of the protein exceeded 20 mV, when before the threshold the interactions were mainly governed by size exclusion.


Soil Science ◽  
1992 ◽  
Vol 154 (2) ◽  
pp. 145-150 ◽  
Author(s):  
N. B. STOLPE ◽  
P. J. SHEA ◽  
D. T. LEWIS ◽  
D. L. MCCALLISTER

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shunsuke Furukawa ◽  
Jianyun Wu ◽  
Masaya Koyama ◽  
Keisuke Hayashi ◽  
Norihisa Hoshino ◽  
...  

AbstractOrganic ferroelectrics, in which the constituent molecules retain remanent polarization, represent an important topic in condensed-matter science, and their attractive properties, which include lightness, flexibility, and non-toxicity, are of potential use in state-of-the-art ferroelectric devices. However, the mechanisms for the generation of ferroelectricity in such organic compounds remain limited to a few representative concepts, which has hitherto severely hampered progress in this area. Here, we demonstrate that a bowl-to-bowl inversion of a relatively small organic molecule with a bowl-shaped π-aromatic core generates ferroelectric dipole relaxation. The present results thus reveal an unprecedented concept to produce ferroelectricity in small organic molecules, which can be expected to strongly impact materials science.


1997 ◽  
Vol 161 ◽  
pp. 419-429 ◽  
Author(s):  
Antonio Lazcano

AbstractDifferent current ideas on the origin of life are critically examined. Comparison of the now fashionable FeS/H2S pyrite-based autotrophic theory of the origin of life with the heterotrophic viewpoint suggest that the later is still the most fertile explanation for the emergence of life. However, the theory of chemical evolution and heterotrophic origins of life requires major updating, which should include the abandonment of the idea that the appearance of life was a slow process involving billions of years. Stability of organic compounds and the genetics of bacteria suggest that the origin and early diversification of life took place in a time period of the order of 10 million years. Current evidence suggest that the abiotic synthesis of organic compounds may be a widespread phenomenon in the Galaxy and may have a deterministic nature. However, the history of the biosphere does not exhibits any obvious trend towards greater complexity or «higher» forms of life. Therefore, the role of contingency in biological evolution should not be understimated in the discussions of the possibilities of life in the Universe.


Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.


Sign in / Sign up

Export Citation Format

Share Document