Controlling Factors of Weak Acid and Base Concentrations in Urban Dewwater—Comparison of Dew Chemistry with Rain and Fog Chemistry—

2002 ◽  
Vol 75 (4) ◽  
pp. 757-764 ◽  
Author(s):  
Masaki Takeuchi ◽  
Hiroshi Okochi ◽  
Manabu Igawa
Keyword(s):  
Weak Acid ◽  
Controlling Factors ◽  
Fog Chemistry ◽  
Acid And Base

A model for the thermal regeneration of ion-exchange resins, Part I

1971 ◽  
Vol 24 (10) ◽  
pp. 1979 ◽  
Author(s):  
SD Hamann
Keyword(s):  
Ion Exchange ◽  
Weak Acid ◽  
Ion Exchange Resins ◽  
Equilibrium Conditions ◽  
Thermal Regeneration ◽  
Equilibrium Relationship ◽  
Acid And Base ◽  
Temperature And Pressure ◽  
Exchange Resins ◽  
Ionization Of Water

A theoretical model has been developed to describe the thermal regeneration of ion-exchange resins in the Sirotherm process1-10 for desalting water. It assumes that the thermal effect is primarily due to the large increase that occurs in the ionization of water when the temperature is raised. The hydrogen and hydroxyl ions compete with salt for exchange sites in the resins and for that reason water, itself, acts as a regenerating acid and base. ��� Calculations have been made of the equilibrium conditions, column behaviour, and titration behaviour of mixtures of weak-acid and weak-base resins with aqueous solutions of 1 : 1 and 2 : 2 electrolytes, assuming the systems to obey Donnan's equilibrium relationship. There is satisfactory agreement between the calculated and observed effects of both temperature and pressure.

scholarly journals Regulation of Intracellular pH in Sea Urchin Eggs by Medium Containing Both Weak Acid and Base.

1997 ◽  
Vol 22 (4) ◽  
pp. 387-398 ◽  
Author(s):  
Miyako S. Hamaguchi ◽  
Kenji Watanabe ◽  
Yukihisa Hamaguchi
Keyword(s):  
Intracellular Ph ◽  
Sea Urchin ◽  
Weak Acid ◽  
Sea Urchin Eggs ◽  
Acid And Base

scholarly journals Quantitative Prediction of pH-Controlled Ionization of Oligopeptides

2020 ◽  
Author(s):  
Raju Lunkad ◽  
Anastasiia Murmiliuk ◽  
Pascal Hebbeker ◽  
Milan Boublík ◽  
Zdeněk Tošner ◽  
...  
Keyword(s):  
Electrostatic Interactions ◽  
Weak Acid ◽  
Coarse Grained ◽  
Quantitative Prediction ◽  
Bottom Up ◽  
Coarse Grained Model ◽  
Flexible Polymer ◽  
Acid And Base ◽  
Base Side ◽  
Capillary Zone

Weak ampholytes are ubiquitous in nature and commonly found in artificial pH-responsive systems. However, our limited understanding of their ionisation response and the lack of predictive capabilities hinder the bottom-up design of such systems. Here, we used a coarse-grained model of a flexible polymer with weakly ionisable monomer units to quantitatively analyse the ionisation behaviour of two oligopeptides. Differences in ionisation response between oligopeptides and monomeric amino acids showed that electrostatic interactions between weak acid and base side chains play a key role in oligopeptide ionisation, as predicted by our model. Moreover, by comparing our simulations with experimental results from potentiometric titration, capillary zone electrophoresis and NMR, we demonstrated that our model reliably predicts the ionisation response and electrophoretic mobilities of various peptide sequences. Ultimately, our model is the first step towards using predictive bottom-up design of responsive ampholytes to tailor their properties as a function of charge and pH.<br>

scholarly journals Online Module for Acid and Base Topic Based on 5E Model

2021 ◽  
Vol 15 (23) ◽  
pp. 18-29
Author(s):  
Nurul Nazatul Shahizah Mahamd Shobri ◽  
Johari Surif ◽  
Nor Hasniza Ibrahim ◽  
Wimbi Apriwanda Nursiwan ◽  
Muhammad Abd Hadi Bunyamin
Keyword(s):  
Online Teaching ◽  
Teaching And Learning ◽  
Weak Acid ◽  
Design Development ◽  
Online Teaching And Learning ◽  
Online Module ◽  
Interactive Tools ◽  
5E Instructional Model ◽  
Acid And Base ◽  
Addie Model

Alternative conception or misconception is one of the problems that often be experienced by the students in science subjects including chemistry due to its abstractness and wide scope to be learned. Previous studies found that students often have misconceptions on strength of acid and base topic such as misconception in determining factor that affect the strength of acid and base, differences between strong and weak acid and base as well as the effect of strength of acid and base on conductivity. To overcome these misconceptions, an online teaching and learning module using 5E instructional model was developed. Analysis, Design, Development, Implementation and Evaluation (ADDIE) model is used for research and development. The module used interactive tools and medias to make students being active and understand chemistry well. This module was validated by five experts in term of module objectives, module content, usability, flexibility, learning activities and language aspects with average is ninety percent. The results prove that the module is very good and has high validity. Therefore, the application of online module for acid and base topic based on 5E (Engage, Explore, Explain, Elaborate, Evaluate) model is suitable to be implemented in online teaching and learning process.

scholarly journals Quantitative Prediction of Charge Regulation in Oligopeptides

2020 ◽  
Author(s):  
Raju Lunkad ◽  
Anastasiia Murmiliuk ◽  
Pascal Hebbeker ◽  
Milan Boublík ◽  
Zdeněk Tošner ◽  
...  
Keyword(s):  
Electrostatic Interactions ◽  
Weak Acid ◽  
Coarse Grained ◽  
Disordered Proteins ◽  
Quantitative Prediction ◽  
Bottom Up ◽  
Charge Regulation ◽  
Flexible Polymer ◽  
Acid And Base ◽  
Base Side

Weak ampholytes are ubiquitous in nature and commonly found in artificial pH-responsive systems. However, our limited understanding of their charge regulation and the lack of predictive capabilities hinder the bottom-up design of such systems. Here, we used a coarse-grained model of a flexible polymer with weakly ionisable monomer units to quantitatively analyse the ionisation behaviour of two oligopeptides. Our model predicts differences in the charge states between oligopeptides and monomeric amino acids, showing that conformational flexibility and electrostatic interactions between weak acid and base side chains play a key role in the charge regulation. By comparing our simulations with experimental results from potentiometric titration, capillary zone electrophoresis and NMR, we demonstrated that our model reliably predicts the charge state of various peptide sequences. Ultimately, our model is the first step towards understanding the charge regualtion in flexible disordered proteins, and towards using predictive bottom-up design of responsive ampholytes to tailor their<br>properties as a function of charge and pH.<br>

scholarly journals Quantitative Prediction of Charge Regulation in Oligopeptides

2020 ◽  
Author(s):  
Raju Lunkad ◽  
Anastasiia Murmiliuk ◽  
Pascal Hebbeker ◽  
Milan Boublík ◽  
Zdeněk Tošner ◽  
...  
Keyword(s):  
Electrostatic Interactions ◽  
Weak Acid ◽  
Coarse Grained ◽  
Disordered Proteins ◽  
Quantitative Prediction ◽  
Bottom Up ◽  
Charge Regulation ◽  
Flexible Polymer ◽  
Acid And Base ◽  
Base Side

Weak ampholytes are ubiquitous in nature and commonly found in artificial pH-responsive systems. However, our limited understanding of their charge regulation and the lack of predictive capabilities hinder the bottom-up design of such systems. Here, we used a coarse-grained model of a flexible polymer with weakly ionisable monomer units to quantitatively analyse the ionisation behaviour of two oligopeptides. Our model predicts differences in the charge states between oligopeptides and monomeric amino acids, showing that conformational flexibility and electrostatic interactions between weak acid and base side chains play a key role in the charge regulation. By comparing our simulations with experimental results from potentiometric titration, capillary zone electrophoresis and NMR, we demonstrated that our model reliably predicts the charge state of various peptide sequences. Ultimately, our model is the first step towards understanding the charge regualtion in flexible disordered proteins, and towards using predictive bottom-up design of responsive ampholytes to tailor their<br>properties as a function of charge and pH.<br>

scholarly journals Quantitative Prediction of pH-Controlled Ionization of Oligoampholytes

2020 ◽  
Author(s):  
Raju Lunkad ◽  
Anastasiia Murmiliuk ◽  
Pascal Hebbeker ◽  
Milan Boublík ◽  
Zdeněk Tošner ◽  
...  
Keyword(s):  
Electrostatic Interactions ◽  
Weak Acid ◽  
Coarse Grained ◽  
Quantitative Prediction ◽  
Bottom Up ◽  
Coarse Grained Model ◽  
Flexible Polymer ◽  
Acid And Base ◽  
Base Side ◽  
Capillary Zone

Weak ampholytes are ubiquitous in nature and commonly found in artificial pH-responsive systems. However, our limited understanding of their ionisation response and the lack of predictive capabilities hinder the bottom-up design of such systems. Here, we used a coarse-grained model of a flexible polymer with weakly ionisable monomer units to quantitatively analyse the ionisation behaviour of two oligopeptides. Differences in ionisation response between oligopeptides and monomeric amino acids showed that electrostatic interactions between weak acid and base side chains play a key role in oligopeptide ionisation, as predicted by our model. Moreover, by comparing our simulations with experimental results from potentiometric titration, capillary zone electrophoresis and NMR, we demonstrated that our model reliably predicts the ionisation response and electrophoretic mobilities of various peptide sequences. Ultimately, our model is the first step towards using predictive bottom-up design of responsive ampholytes to tailor their properties as a function of charge and pH.<br>

scholarly journals Quantitative Prediction of Charge Regulation in Oligopeptides

2020 ◽  
Author(s):  
Raju Lunkad ◽  
Anastasiia Murmiliuk ◽  
Pascal Hebbeker ◽  
Milan Boublík ◽  
Zdeněk Tošner ◽  
...  
Keyword(s):  
Electrostatic Interactions ◽  
Weak Acid ◽  
Coarse Grained ◽  
Disordered Proteins ◽  
Quantitative Prediction ◽  
Bottom Up ◽  
Charge Regulation ◽  
Flexible Polymer ◽  
Acid And Base ◽  
Base Side

Weak ampholytes are ubiquitous in nature and commonly found in artificial pH-responsive systems. However, our limited understanding of their charge regulation and the lack of predictive capabilities hinder the bottom-up design of such systems. Here, we used a coarse-grained model of a flexible polymer with weakly ionisable monomer units to quantitatively analyse the ionisation behaviour of two oligopeptides. Our model predicts differences in the charge states between oligopeptides and monomeric amino acids, showing that conformational flexibility and electrostatic interactions between weak acid and base side chains play a key role in the charge regulation. By comparing our simulations with experimental results from potentiometric titration, capillary zone electrophoresis and NMR, we demonstrated that our model reliably predicts the charge state of various peptide sequences. Ultimately, our model is the first step towards understanding the charge regualtion in flexible disordered proteins, and towards using predictive bottom-up design of responsive ampholytes to tailor their<br>properties as a function of charge and pH.<br>

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