scholarly journals Salting kinetics, salt diffusivities and proximate composition in osmotically dehydrated Pirarucu muscle

2018 ◽  
Author(s):  
Andrea Carla Da Silva Barretto ◽  
Tiago Luís Barretto ◽  
Lilian Fachin Leonardo Betiol ◽  
Elisa Rafaella Bonadio Bellucci ◽  
Javier Telis-Romero
Keyword(s):  
Diffusion Coefficients ◽  
Low Cost ◽  
Chloride Diffusion ◽  
Diffusion Kinetics ◽  
One Dimensional ◽  
Dimensional Diffusion ◽  
Arapaima Gigas ◽  
Infinite Slab ◽  
Meat Preservation ◽  
Salt Diffusion

Pirarucu (Arapaima gigas Schinz) farming has been encouraged and, among meat preservation techniques, the salting process is a relatively simple and low-cost method. The objective of this work was to study the sodium chloride diffusion kinetics in Pirarucu during wet salting. Limited volumes of brine (20% w/w) were employed with wet salting assays carried at 3, 4 and 5 brine/muscle ratios, and brine temperatures of 10, 15 and 20 oC. The analytical solution of Fick's second law considering one-dimensional diffusion through an infinite slab in contact with a well-stirred solution of limited volume was used to calculate the effective salt diffusion coefficients. Salt diffusivities in muscle were found to be in the range of 2.07 and 8.80 ´ 10-10 m2/s. The wet salting of Pirarucu is greatly influenced by temperature and by the brine/muscle ratio by volume.Keywords: Pirarucu; Arapaima gigas Schinz; salt diffusion coefficients; brine.  

scholarly journals Salting kinetics and salt diffusivities in farmed Pantanal caiman muscle

2003 ◽  
Vol 38 (4) ◽  
pp. 529-535 ◽  
Author(s):  
Vânia Regina Nicoletti Telis ◽  
Pedro Fernando Romanelli ◽  
Ana Lúcia Gabas ◽  
Javier Telis-Romero
Keyword(s):  
Sodium Chloride ◽  
Low Cost ◽  
Chloride Content ◽  
Chloride Diffusion ◽  
One Dimensional ◽  
Dimensional Diffusion ◽  
Infinite Slab ◽  
Meat Preservation ◽  
Salt Diffusion ◽  
Good Agreement

The legal Pantanal caiman (Caiman crocodilus yacare) farming, in Brazil, has been stimulated and among meat preservation techniques the salting process is a relatively simple and low-cost method. The objective of this work was to study the sodium chloride diffusion kinetics in farmed caiman muscle during salting. Limited volumes of brine were employed, with salting essays carried at 3, 4 and 5 brine/muscle ratios, at 15%, 20% and 25% w/w brine concentrations, and brine temperatures of 10, 15 and 20ºC. The analytical solution of second Fick's law considering one-dimensional diffusion through an infinite slab in contact with a well-stirred solution of limited volume was used to calculate effective salt diffusion coefficients and to predict the sodium chloride content in the fillets. A good agreement was obtained between the considered analytical model and experimental data. Salt diffusivities in fillets were found to be in the range of 0.47x10-10 to 9.62x10-10 m²/s.

Analysis of Chloride Penetration into the Corner Zone of Concrete Structure Member

2007 ◽  
Vol 348-349 ◽  
pp. 397-400
Author(s):  
Xiao Yong Wang ◽  
Han Seung Lee ◽  
Hai Moon Jung
Keyword(s):  
Service Life ◽  
Diffusion Process ◽  
Concrete Structure ◽  
Chloride Concentration ◽  
Chloride Penetration ◽  
Chloride Diffusion ◽  
Recent Analysis ◽  
Two Dimensional ◽  
One Dimensional ◽  
Dimensional Diffusion

Chloride penetration into concrete is the main cause of steel corrosion in concrete structures exposed to chloride-rich environments. In general, conditions on the diffusion process are dominant among various penetration mechanisms, such as ionic diffusion, capillary sorption, and so on. In recent analysis of current literature, chloride diffusion is as a simplified one-dimensional diffusion process. However, for the rebar in the corner zone of concrete beam, the diffusion belongs to a two-dimensional diffusion. Based on a galerkin finite element method, a two-dimensional diffusion differential equation is built and solved numerically and the different chloride concentration is compared to one dimensional diffusion and two-dimensional diffusion process. The service life of concrete structure members under two-dimensional chloride penetration is predicted by compared with a critical threshold chloride concentration. Compared with general one-dimensional chloride attack, the service life is considerably reduced in a corner zone due to two-dimension penetration.

A new single-particle model to evaluate the Li-ions diffusion coefficients of LiMn1−xFexPO4

2019 ◽  
Vol 12 (05) ◽  
pp. 1950071
Author(s):  
Hejie Li ◽  
Hongbin Wang ◽  
Wenju Ren ◽  
Jiangtao Hu ◽  
Yuan Lin ◽  
...  
Keyword(s):  
Single Particle ◽  
Diffusion Coefficients ◽  
Particle Model ◽  
Cyclic Voltammogram ◽  
Ion Diffusion ◽  
One Dimensional ◽  
Reduction Processes ◽  
Dimensional Diffusion ◽  
Li Ion ◽  
Single Particle Model

It remains a challenge to evaluate the Li-ions diffusion coefficients of LiMn[Formula: see text]FexPO4 due to the presence of two voltage platforms upon charge/discharge. In this paper, a new single-particle model based on Butler–Volmer (BV) equation and one-dimensional diffusion equation is established. Using this model, the cyclic voltammogram curves of LiMn[Formula: see text]FexPO4 single-particle electrodes are successfully fitted and their Li-ion diffusion coefficients in organic electrolyte are obtained. Through analyzing the diffusion coefficients, it is found that the Li-ions diffusion coefficients for both Fe and Mn redox processes in LiMn[Formula: see text]FexPO4 reach the maximum when [Formula: see text]. In addition, the values for oxidation processes are much larger than those for reduction processes.

scholarly journals Hopping and Flipping of RNA Polymerase on DNA during Recycling for Reinitiation after Intrinsic Termination in Bacterial Transcription

2021 ◽  
Vol 22 (5) ◽  
pp. 2398
Author(s):  
Wooyoung Kang ◽  
Seungha Hwang ◽  
Jin Young Kang ◽  
Changwon Kang ◽  
Sungchul Hohng
Keyword(s):  
Single Molecule ◽  
Transcription Initiation ◽  
Molecular Mechanisms ◽  
Facilitated Diffusion ◽  
One Dimensional ◽  
Bacterial Transcription ◽  
Fluorescence Measurements ◽  
Dimensional Diffusion ◽  
Single Molecule Studies ◽  
Hopping Diffusion

Two different molecular mechanisms, sliding and hopping, are employed by DNA-binding proteins for their one-dimensional facilitated diffusion on nonspecific DNA regions until reaching their specific target sequences. While it has been controversial whether RNA polymerases (RNAPs) use one-dimensional diffusion in targeting their promoters for transcription initiation, two recent single-molecule studies discovered that post-terminational RNAPs use one-dimensional diffusion for their reinitiation on the same DNA molecules. Escherichia coli RNAP, after synthesizing and releasing product RNA at intrinsic termination, mostly remains bound on DNA and diffuses in both forward and backward directions for recycling, which facilitates reinitiation on nearby promoters. However, it has remained unsolved which mechanism of one-dimensional diffusion is employed by recycling RNAP between termination and reinitiation. Single-molecule fluorescence measurements in this study reveal that post-terminational RNAPs undergo hopping diffusion during recycling on DNA, as their one-dimensional diffusion coefficients increase with rising salt concentrations. We additionally find that reinitiation can occur on promoters positioned in sense and antisense orientations with comparable efficiencies, so reinitiation efficiency depends primarily on distance rather than direction of recycling diffusion. This additional finding confirms that orientation change or flipping of RNAP with respect to DNA efficiently occurs as expected from hopping diffusion.

Sign in / Sign up

Export Citation Format

Share Document