Factors affecting the kinetics of DNA reassociation in phenol-water emulsion at high DNA concentrations

Biopolymers ◽  
1982 ◽  
Vol 21 (3) ◽  
pp. 665-677 ◽  
Author(s):  
Robert Wieder ◽  
James G. Wetmur
2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Ilias Gavrielatos ◽  
Ramin Dabirian ◽  
Ram S. Mohan ◽  
Ovadia Shoham

A state-of-the-art, portable dispersion characterization rig (P-DCR) is used to investigate the effect of nanoparticles (NP) on oil-water emulsion formation and stabilization. Spherical silica NP of different wettabilities were used to investigate their effect on separation kinetics of solid stabilized emulsions in terms of solid particle concentration, wettability, initial dispersion phase, water-cut, and shearing time. The main findings of the study include the following: NP, even at concentrations as low as 0.005% or 0.01% (by weight), can significantly increase separation time of oil/water emulsions from a few minutes to several hours or even days. The P-DCR is recommended as an effective inline tool to measure emulsion stability in the field.


2019 ◽  
Author(s):  
Shahin Safavizadeh ◽  
Brina M. Montoya ◽  
Mohammed A. Gabr ◽  
Detlef R. U. Knappe

Author(s):  
Anubha Bhatla ◽  
Y. Lawrence Yao

Crystallinity of semicrystalline polymers such as aliphatic homopolymer poly(L-lactic acid) (PLLA) affects their degradation and physical properties. In this paper, the effects of laser irradiation using the third harmonic of a Nd:YAG laser on the crystallinity, long-range order, and short-range conformations at the surface of PLLA films are investigated. The factors affecting the transformation are also studied. Detailed characterization of the effect of laser treatment is accomplished using microscopy, X-ray diffraction, and infrared spectroscopy. The cooling rates in the process and the spatial and temporal temperature profiles are numerically examined. The simulation results in conjunction with melting and crystallization kinetics of PLLA are used to understand the effect on sample crystallinity. The effects of laser fluence and annealing conditions on the crystallinity of the processed films are examined. Since degradation profiles depend on crystallinity, laser processing can potentially be used to achieve a modified spatially controlled polymer surface with promising applications such as controlled drug delivery.


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