Assessment of Mehlich3 and Ammonium Bicarbonate‐DTPA Extraction for Simultaneous Measurement of Fifteen Elements in Soils

2003 ◽  
Vol 34 (19-20) ◽  
pp. 2817-2838 ◽  
Author(s):  
M. A. Elrashidi ◽  
M. D. Mays ◽  
C. W. Lee
Keyword(s):  
Simultaneous Measurement ◽  
Ammonium Bicarbonate ◽  
Dtpa Extraction

Ammonium bicarbonate‐DTPA extraction of elements from waste‐amended calcareous soil

1996 ◽  
Vol 27 (9-10) ◽  
pp. 2321-2335 ◽  
Author(s):  
E. A. Hanlon ◽  
B. Schaffer ◽  
M. Ozores‐Hampton ◽  
H. H. Bryan
Keyword(s):  
Calcareous Soil ◽  
Ammonium Bicarbonate ◽  
Dtpa Extraction

Fibrillin molecules aggregate to form an extendible beaded structure which is a major component of “Elastin Associated” microfibrils

1989 ◽  
Vol 47 ◽  
pp. 246-247
Author(s):  
Douglas R. Keene ◽  
B. Kerry Maddox ◽  
Marie B. Spurgin ◽  
Lynn Y. Sakai ◽  
Robert W. Glanville
Keyword(s):  
Molecular Sieve ◽  
Room Temperature ◽  
Culture Medium ◽  
Weight Fraction ◽  
Ammonium Bicarbonate ◽  
High Molecular Weight Fraction ◽  
Bicarbonate Buffer ◽  
Human Amnion ◽  
Gold Conjugate ◽  
Ammonium Bicarbonate Buffer

A mouse monoclonal antibody was used to identify beaded aggregates found in guanidine extracts of human amnion as assemblies of fibrillin molecules. These aggregates were also shown to be a major component of extracellular matrix microfibrils. We further demonstrated that the periodicity of these aggregates can be increased when subjected to mechanical stress.Human amnion was extracted with guanidine and the extracted material purified using ion exchange and molecular sieve chromatography. A high molecular weight fraction was precipitated by dialyzing against dilute acetic acid. Part of the precipitate was suspended in 0.2 M ammonium bicarbonate buffer and rotary shadowed. A second portion was resuspended in culture medium containing antibody which recognizes matrix microfibrils, diluted 1:5 in ammonium bicarbonate and reacted for 120 minutes at room temperature. Antibody labeled precipitate was washed by repeated pelleting and resuspension in buffer and then incubated in Janssen GAM 5 nm gold conjugate for 60 minutes at room temperature.

Simultaneous Measurement of Bend Direction and Degree of Curvature using Micromachined Grating Fibers

2014 ◽  
Vol 134 (3) ◽  
pp. 41-46
Author(s):  
Hironori Kumazaki ◽  
Munehiro Hiramatsu ◽  
Hisakazu Oguri ◽  
Seiki Inaba ◽  
Kazuhiro Hane
Keyword(s):  
Simultaneous Measurement

Simultaneous measurement of atmospheric moisture and temperature in the presence of suspended particulates using ultrasonic technique

2020 ◽  
Vol 59 (9) ◽  
pp. 096503
Author(s):  
Nairit Das ◽  
Neha Bhattacharyya ◽  
Soumendra Singh ◽  
Animesh Halder ◽  
Deep Shikha ◽  
...  
Keyword(s):  
Simultaneous Measurement ◽  
Ultrasonic Technique ◽  
Atmospheric Moisture ◽  
Suspended Particulates

Temperature Dependent Green Synthesis of 3-Carboxycoumarins and 3,4-unsubstituted Coumarins

2019 ◽  
Vol 16 (1) ◽  
pp. 130-135 ◽  
Author(s):  
Jack van Schijndel ◽  
Dennis Molendijk ◽  
Luiz Alberto Canalle ◽  
Erik Theodorus Rump ◽  
Jan Meuldijk
Keyword(s):  
Knoevenagel Condensation ◽  
Ammonium Bicarbonate ◽  
Solvent Free ◽  
Temperature Dependent ◽  
Step Procedure ◽  
Synthetic Routes ◽  
High Yields ◽  
Temperature Optima ◽  
Solvent Free Synthesis ◽  
Full Conversion

Aim and Objective: Because of the low abundance of 3,4-unsubstituted coumarins in plants combined with the complex purification process required, synthetic routes towards 3,4-unsubstituted coumarins are especially valuable. In the present work, we explore the possibilities of a solvent-free Green Knoevenagel condensation on various 2-hydroxybenzaldehyde derivatives and malonic acid without the use of toxic organocatalysts like pyridine and piperidine but only use ammonium bicarbonate as the catalyst. Materials and Methods: To investigate the scope of the Green Knoevenagel condensation for the synthesis of 3,4-unsubstituted coumarins, various 2-hydroxybenzaldehyde derivatives were screened as starting material in the optimized two-step procedure developed for 2-hydroxybenzaldehyde. </P><P> Results: This study shows that the intramolecular esterification and the decarboxylation are in competition, but show different temperature optima. In order to suppress premature decarboxylation and maximize the yield of coumarin, a two-step procedure was adopted. The reaction mixture containing ammonium bicarbonate is initially kept at 90ºC for 1 hour. After completion of the cyclization, the temperature of the reaction mixture is increased to 140ºC for 2 hours. Following this protocol, coumarin could be isolated with a yield of 95%. Conclusion: A two-step procedure for the solvent-free synthesis of several 3,4-unsubstituted coumarins was developed using ammonium bicarbonate, resulting in high yields of the desired products. Moreover, this procedure has a low E-factor and is, therefore an environmental friendly reaction in line with the principles of Green Chemistry. It was shown that by initially capping the temperature at 90ºC, premature decarboxylation can be suppressed. After full conversion to the intermediate 3-carboxycoumarin, the temperature can be increased to 140ºC finalizing the reaction. Ammonium bicarbonate was shown to catalyze both the Green Knoevenagel condensation and the decarboxylation step.

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