The influence of chromatin compactness on the stoichiometry of the Feulgen-Schiff procedure studied in model films. I. Theoretical kinetics and experiments with films containing isolated deoxyribonucleic acid.

1975 ◽  
Vol 23 (12) ◽  
pp. 882-890 ◽  
Author(s):  
W A Duijndam ◽  
P van Duijn
Keyword(s):  
Theoretical Model ◽  
Deoxyribonucleic Acid ◽  
Experimental Results ◽  
Gel Chromatography ◽  
Ultraviolet Absorbance ◽  
Purine Bases ◽  
Chromatin Compactness ◽  
Schiff Reaction ◽  
Theoretical Considerations ◽  
Kinetics Of

Theoretical considerations on the expected kinetics of the course of the Feulgen-Schiff reaction show that the leveling off of the first part of the Feulgen hydrolysis curve can be explained by the gradual conversion of deoxyribonucleic acid (DNA) to apurinic acid (APA). In addition, depolymerization of DNA caused by the acid used for hydrolysis can account for the decline after a maximum is reached in this curve. With the aid of polyacrylamide model films containing DNA, a detailed study was made both of the process of purine liberation which results in the formation of APA and of the depolymerization processes which cause losses of stainable material. The liberation of purine bases was analyzed by ultraviolet absorbance measurements and by gel chromatography of the neutralized hydrolysing acid. APA concentration was monitored by following the loss of ultraviolet absorbance associated with the purine losses. The depolymerization process was followed by phosphorus determinations. The experimental results were found to be in accordance with the kinetics expected from the theoretical model.

scholarly journals The kinetics of the formation of oxygen films on tungsten

1939 ◽  
Vol 173 (952) ◽  
pp. 13-27 ◽  
Keyword(s):  
Partial Pressure ◽  
Adsorbed Layer ◽  
Preceding Paper ◽  
Accommodation Coefficient ◽  
Experimental Results ◽  
Partial Pressure Of Oxygen ◽  
Steady Pressure ◽  
The Wire ◽  
Theoretical Considerations ◽  
Kinetics Of

1. Experimental results In the preceding paper the application of a method for maintaining a very low steady pressure of oxygen to determine the nature of the complex adsorbed layer of this gas on tungsten has been described. We shall now discuss the use of the method to study the process of formation of the adsorbed film. In figure 1 the accommodation coefficient of neon is plotted as a function of the time. At the instant indicated by the arrow oxygen was admitted to the bulb B (see figure 1 of the preceding paper). It will be seen that at the beginning of the experiment, i.e. before the oxygen was admitted, the amount of impurity in the neon was so small that the drift was practically negligible. An idea of the sort of eonditions that are necessary for the drift to be negligible will be realized from the fact that the partial pressure of oxygen established at the wire in this particular experiment was only 2·3 x 10 -9 mm. of mercury. The gradient da/dt of this and similar curves was measured at various points, and in no case were measurements included for points less than 2 min. after the admission of the oxygen. Experimental and theoretical considerations indicate that by this time a steady pressure of oxygen was established at the wire.

Kinetics of CO2Hydrate Formation from Water Frost at Low Temperatures: Experimental Results and Theoretical Model

2011 ◽  
Vol 115 (10) ◽  
pp. 4022-4032 ◽  
Author(s):  
Andrzej Falenty ◽  
Georgi Genov ◽  
Thomas C. Hansen ◽  
Werner F. Kuhs ◽  
Andrey N. Salamatin
Keyword(s):  
Theoretical Model ◽  
Low Temperatures ◽  
Experimental Results ◽  
Kinetics Of

Actuation and dynamic mechanical characteristics of a core free flat dielectric electro-active polymer soft actuator

2020 ◽  
Vol 14 (4) ◽  
pp. 7396-7404
Author(s):  
Abdul Malek Abdul Wahab ◽  
Emiliano Rustighi ◽  
Zainudin A.
Keyword(s):  
Theoretical Model ◽  
Resonance Frequency ◽  
Dynamic Testing ◽  
Experimental Results ◽  
Percentage Error ◽  
Initial Tension ◽  
Average Percentage ◽  
Soft Actuator ◽  
Average Percentage Error ◽  
Mechanical Dynamics

Various complex shapes of dielectric electro-active polymer (DEAP) actuator have been promoted for several types of applications. In this study, the actuation and mechanical dynamics characteristics of a new core free flat DEAP soft actuator were investigated. This actuator was developed by Danfoss PolyPower. DC voltage of up to 2000 V was supplied for identifying the actuation characteristics of the actuator and compare with the existing formula. The operational frequency of the actuator was determined by dynamic testing. Then, the soft actuator has been modelled as a uniform bar rigidly fixed at one end and attached to mass at another end. Results from the theoretical model were compared with the experimental results. It was found that the deformation of the current actuator was quadratic proportional to the voltage supplied. It was found that experimental results and theory were not in good agreement for low and high voltage with average percentage error are 104% and 20.7%, respectively. The resonance frequency of the actuator was near 14 Hz. Mass of load added, inhomogeneity and initial tension significantly affected the resonance frequency of the soft actuator. The experimental results were consistent with the theoretical model at zero load. However, due to inhomogeneity, the frequency response function’s plot underlines a poor prediction where the theoretical calculation was far from experimental results as values of load increasing with the average percentage error 15.7%. Hence, it shows the proposed analytical procedure not suitable to provide accurate natural frequency for the DEAP soft actuator.

scholarly journals Investigation of cultivated lavender (Lavandula officinalis L.) extraction and its extracts

2014 ◽  
Vol 20 (1) ◽  
pp. 71-86 ◽  
Author(s):  
Vesna Nadjalin ◽  
Zika Lepojevic ◽  
Mihailo Ristic ◽  
Jelena Vladic ◽  
Branislava Nikolovski ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Essential Oil ◽  
Experimental Results ◽  
Flame Ionisation Detector ◽  
Main Components ◽  
Lavandula Officinalis ◽  
Physical And Chemical ◽  
Kinetics Of ◽  
Flame Ionisation ◽  
Ionisation Detector

In this study essential oil content was determined in lavender flowers and leaves by hydrodistillation. Physical and chemical characteristics of the isolated oils were determined. By using CO2 in supercritical state the extraction of lavender flowers was performed with a selected solvent flow under isothermal and isobaric conditions. By the usage of gas chromatography in combination with mass spectrometry (GC/MS) and gas chromatography with flame ionisation detector (GC/FID) the qualitative and quantitative analysis of the obtained essential oil and supercritical extracts (SFE) was carried out. Also, the analysis of individual SFE extracts obtained during different extraction times was performed. It turned out that the main components of the analysed samples were linalool, linalool acetate, lavandulol, caryophyllene oxide, lavandulyl acetate, terpinen-4-ol and others. Two proposed models were used for modelling the extraction system lavender flower - supercritical CO2 on the basis of experimental results obtained by examining the extraction kinetics of this system. The applied models fitted well with the experimental results.

Etude par spectrométrie infrarouge de l'action de solvants aprotiques sur l'association ester–eau et ester–Ba2+. Discussion du rôle catalytique du solvant et de l'ion Ba2+ dans l'hydrolyse alcaline du propionate de methyle

1979 ◽  
Vol 57 (4) ◽  
pp. 400-403 ◽  
Author(s):  
Anne Le Narvor ◽  
Pierre Saumagne
Keyword(s):  
Ir Spectra ◽  
Charge Density ◽  
Carbonyl Group ◽  
Alkaline Hydrolysis ◽  
Experimental Results ◽  
Methyl Propionate ◽  
Orbital Control ◽  
Different Types ◽  
Kinetics Of ◽  
Better Than

The ir spectra of mixtures of methyl propionate/water and methyl propionate/Ba2+ in dimethylsulfoxide and in acetonitrile have been recorded in the region of the νCO mode of the ester. Evidence is presented to indicate the presence of different types of complexes; their concentration was determined as a function of the composition of the medium. The spectroscopic results are compared to those from the kinetics of the alkaline hydrolysis in the same conditions. It is demonstrated that the orbital control explains the experimental results better than does the charge density on the carbon of the carbonyl group. [Journal translation]

scholarly journals Kinetics of CO2 absorption by aqueous 3-(methylamino)propylamine solutions: Experimental results and modeling

AIChE Journal ◽  
2014 ◽  
Vol 60 (11) ◽  
pp. 3792-3803 ◽  
Author(s):  
Juliana G. M.-S. Monteiro ◽  
Saddam Hussain ◽  
Hammad Majeed ◽  
Emmanuel O. Mba ◽  
Ardi Hartono ◽  
...  
Keyword(s):  
Experimental Results ◽  
Co2 Absorption ◽  
Kinetics Of
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