scholarly journals Electrochemical quantification of accelerated FADGDH rates in aqueous nanodroplets

2021 ◽  
Vol 118 (25) ◽  
pp. e2025726118
Author(s):  
Kathryn J. Vannoy ◽  
Inyoung Lee ◽  
Koji Sode ◽  
Jeffrey E. Dick
Keyword(s):  
Finite Element ◽  
Inverse Relationship ◽  
Chemical Reactivity ◽  
Bulk Water ◽  
Water Volume ◽  
Current Time ◽  
Faraday’S Law ◽  
Influence Of Water ◽  
Time Trace ◽  
Strong Inverse Relationship

Enzymes are molecules that catalyze reactions critical to life. These catalysts are often studied in bulk water, where the influence of water volume on reactivity is neglected. Here, we demonstrate rate enhancement of up to two orders of magnitude for enzymes trapped in submicrometer water nanodroplets suspended in 1,2-dichloroethane. When single nanodroplets irreversibly adsorb onto an ultramicroelectrode surface, enzymatic activity is apparent in the amperometric current-time trace if the ultramicroelectrode generates the enzyme cofactor. Nanodroplet volume is easily accessible by integrating the current-time response and using Faraday’s Law. The single nanodroplet technique allows us to plot the enzyme’s activity as a function of nanodroplet size, revealing a strong inverse relationship. Finite element simulations confirm our experimental results and offer insights into parameters influencing single nanodroplet enzymology. These results provide a framework to profoundly influence the understanding of chemical reactivity at the nanoscale.

Moss distribution in streams of the Quebec Laurentian Mountains

2000 ◽  
Vol 78 (6) ◽  
pp. 748-752 ◽  
Author(s):  
Antonella Cattaneo ◽  
Lucie Fortin
Keyword(s):  
Water Depth ◽  
Inverse Relationship ◽  
Competitive Interaction ◽  
Filamentous Cyanobacterium ◽  
Patchy Distribution ◽  
Moss Cover ◽  
Aquatic Mosses ◽  
Water Ph ◽  
Strong Inverse Relationship ◽  
Substratum Size

To model the distribution of aquatic mosses, we measured their cover in 33 Quebec streams. The variation in moss cover among streams was explained mostly (42%) by substratum size (percentage >25 cm in diameter). Water pH and depth also explained a significant amount of variation (9 and 10%, respectively). Within a stream, moss cover was again positively correlated to the availability of large substrata and negatively to water depth. There was a strong inverse relationship between covers of moss and of the filamentous cyanobacterium Stigonema, suggesting a competitive interaction. This study confirms previous observations that moss distribution is mainly controlled by substratum size. Chemistry explains part of the among-stream variation. Stigonema-moss competition partly accounts for the patchy distribution within a stream.Key words: aquatic mosses, Fontinalis, streams, Quebec.

Redistributing Control between the Elements of a Compound Stimulus

1970 ◽  
Vol 22 (3) ◽  
pp. 478-483 ◽  
Author(s):  
C. G. Miles ◽  
N. J. Mackintosh ◽  
R. F. Westbrook
Keyword(s):  
Discrimination Training ◽  
Inverse Relationship ◽  
Compound Stimulus ◽  
Strong Inverse Relationship

Twenty-eight pigeons were given discrimination training. Four groups were run in which for 0, 2, 4 and 9 sessions of training colour was an irrelevant cue and tone was relevant. Generalization tests were given in extinction; the training colour (C1) and another colour (C2) were presented with tone (T) and noise (N). Responding to these four stimulus combinations, TC1, TC2, NC1 and NC2, allowed the assessment of control by colour and tone. A reduction of control by colour and an increase in control by tone were found to be positively related to the amount of training with colour irrelevant. Tests showed a strong inverse relationship between control by colour and tone.

scholarly journals An Improved Analytical Solution for Process-Induced Residual Stresses and Deformations in Flat Composite Laminates Considering Thermo-Viscoelastic Effects

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2506 ◽  
Author(s):  
Chao Liu ◽  
Yaoyao Shi
Keyword(s):  
Differential Equation ◽  
Finite Element ◽  
Analytical Solution ◽  
Residual Stresses ◽  
Composite Laminates ◽  
Composite Structures ◽  
Numerical Models ◽  
Element Analysis ◽  
Current Time ◽  
Viscoelastic Effects

Dimensional control can be a major concern in the processing of composite structures. Compared to numerical models based on finite element methods, the analytical method can provide a faster prediction of process-induced residual stresses and deformations with a certain level of accuracy. It can explain the underlying mechanisms. In this paper, an improved analytical solution is proposed to consider thermo-viscoelastic effects on residual stresses and deformations of flat composite laminates during curing. First, an incremental differential equation is derived to describe the viscoelastic behavior of composite materials during curing. Afterward, the analytical solution is developed to solve the differential equation by assuming the solution at the current time, which is a linear combination of the corresponding Laplace equation solutions of all time. Moreover, the analytical solution is extended to investigate cure behavior of multilayer composite laminates during manufacturing. Good agreement between the analytical solution results and the experimental and finite element analysis (FEA) results validates the accuracy and effectiveness of the proposed method. Furthermore, the mechanism generating residual stresses and deformations for unsymmetrical composite laminates is investigated based on the proposed analytical solution.

Influence of water volume, surface area, and water replacement rate on weight gain of juvenile freshwater prawns, Macrobrachium rosenbergii

Aquaculture ◽  
2000 ◽  
Vol 182 (1-2) ◽  
pp. 161-171 ◽  
Author(s):  
Louis R D'Abramo ◽  
William H Daniels ◽  
Patrick D Gerard ◽  
Wan Han Jun ◽  
Curtis G Summerlin
Keyword(s):  
Weight Gain ◽  
Surface Area ◽  
Macrobrachium Rosenbergii ◽  
Water Volume ◽  
Replacement Rate ◽  
Water Replacement ◽  
Influence Of Water

Axisymmetric Finite Element Analysis for Floating Roofs of Aboveground Storage Tanks Under Accumulated Rain Water Condition

2011 ◽  
Author(s):  
Shoichi Yoshida
Keyword(s):  
Finite Element ◽  
Load Condition ◽  
Rain Water ◽  
Water Volume ◽  
Deformation Analysis ◽  
Storage Tanks ◽  
Element Analysis ◽  
Water Condition ◽  
Incremental Method ◽  
Shell Finite Element

The floating roofs are used in large aboveground storage tanks to prevent evaporation of the content. The single-deck floating roof, which is considered herein, consists of a thin circular plate called a deck attached to a buoyant ring of box-shaped cross section called a pontoon. Under the accumulated rain water condition, the deck is deflected largely, and both its edge part and the pontoon are compressed circumferentially. Since the load condition due to the rain water depends on the deflected deck shape, it is difficult to find the unique equilibrium condition. This paper describes the deformation analysis for the single-deck floating roofs under the accumulated rain water condition using the geometrically nonlinear axisymmetric shell finite element method. The load incremental method, in which the equivalent nodal forces due to the rain water converges to coincide with the rain water load derived from both the current rain water volume and the deflected deck shape, is used.

scholarly journals Numerical Simulation of Fog Transport in a Horizontal Channel

2020 ◽  
Vol 330 ◽  
pp. 01033
Author(s):  
Nihel Grich ◽  
Walid Foudhil ◽  
Souad Harmand ◽  
Sadok Ben Jabrallah
Keyword(s):  
Volume Fraction ◽  
Numerical Study ◽  
Horizontal Channel ◽  
Comsol Multiphysics ◽  
Water Volume ◽  
Influence Of Water ◽  
Simulation Results ◽  
Water Volume Fraction ◽  
Phase Water ◽  
2D Numerical Model

Water spraying in exchanger systems is widely used to allow cooling and improving their performance. However, transfers within the spray mixture are difficult to express because the combined mass and heat are transferred between phases, which complicates the design of the spray systems. This article presents a numerical study of the influence of water volume fraction on the distribution of the temperature in a canal. A 2D numerical model of a horizontal channel was generated and the equations governing the continuous phases (air) and the dispersed phase (water) were developed. These equations were solved using Comsol multiphysics. A comparison of the simulation results and those of the experiment reveals an acceptable concordance.

scholarly journals A Transferable Active-Learning Strategy for Reactive Molecular Force Fields

2021 ◽  
Author(s):  
Tom Young ◽  
Tristan Johnston-Wood ◽  
Volker Deringer ◽  
Fernanda Duarte
Keyword(s):  
Active Learning ◽  
Large Scale ◽  
Learning Strategy ◽  
Gaussian Approximation ◽  
Force Fields ◽  
Molecular System ◽  
Chemical Reactivity ◽  
Bulk Water ◽  
Interatomic Potentials ◽  
Molecular Systems

<p>Predictive simulations of dynamic processes in molecular systems require fast, accurate and reactive interatomic potentials. Machine learning offers a promising approach to construct force-field models for large-scale molecular simulation by fitting to high-level quantum-mechanical data. However, machine-learned force fields generally require considerable human intervention and data volume. Here we show that, by leveraging hierarchical and active learning, accurate Gaussian Approximation Potential (GAP) models for diverse chemical systems can be developed in an autonomous way, requiring only hundreds to a few thousand energy and gradient evaluations on the reference potential-energy surface. Our approach relies on a decomposition of the condensed-phase molecular system into intra- and inter-molecular terms, and on the definition of a prospective error metric to quantify accuracy. We demonstrate applications to a range of molecular systems: from bulk water, organic solvents, and a solvated ion onwards to the description of chemical reactivity, including, a bifurcating Diels–Alder reaction in the gas phase and non-equilibrium dynamics (S<sub>N</sub>2 reaction) in explicit solvent. The method provides a route to routinely generating machine-learned force fields for complex and/or reactive molecular systems. </p>

PREDATOR–PREY DYNAMICS WITH SEASONAL WATER-LEVEL FLUCTUATIONS

2018 ◽  
Vol 26 (04) ◽  
pp. 495-510 ◽  
Author(s):  
A. MOUSSAOUI ◽  
M. A. AZIZ-ALAOUI ◽  
S. BASSAID
Keyword(s):  
Water Level ◽  
Great Influence ◽  
Predation Rate ◽  
Water Level Fluctuations ◽  
Water Volume ◽  
Artificial Lake ◽  
Predator Prey ◽  
Predator Prey Model ◽  
Influence Of Water ◽  
Lakes And Reservoirs

Water level in rivers, lakes and reservoirs has great influence on the interactions between prey and predator fish. Indeed, the increase of the water volume hinders the capture of the prey by the predator. The same reasoning applies when there is a decrease in the volume of water, favoring the capture of the prey by the predator. In this paper, we consider a seasonally varying predator–prey model to study the influence of water-level variations on the interaction between two species of fishes in an artificial lake. A seasonal variation of the water-level is introduced in the predation rate taking into account two values, leading to a general switched system. Permanence, stability and existence of an invariant domain containing at least one periodic solution are established. Our theoretical results confirm the assumption that the water exerts a strong influence on the interaction between fishes.

The effects of diets deficient in phosphorus, phosphorus and vitamin D, or calcium, on the skeleton and teeth of the growing sheep IV. The uptake of radioactive phosphorus by the bones and teeth

1965 ◽  
Vol 65 (1) ◽  
pp. 21-27 ◽  
Author(s):  
M. R. McRoberts ◽  
R. Hill ◽  
A. C. Dalgarno
Keyword(s):  
Vitamin D ◽  
Inverse Relationship ◽  
Specific Activity ◽  
Radioactive Phosphorus ◽  
Specific Activities ◽  
Strong Inverse Relationship

1. Radioactive phosphorus was injected into young sheep that had been fed diets low in either phosphorus, phosphorus and vitamin D or calcium. Forty-eight hours after the injection the animals were killed and samples of bone and teeth were removed for specific activity determinations.2. The specific activities of bone varied according to the site from which it was taken, but in general a strong inverse relationship was found between specific activity and the quality of the skeleton.3. In teeth that were formed during the period the diets deficient in phosphorus or phosphorus and vitamin D were fed, the specific activities of the dentine and enamel were greater than for corresponding tissues from the control animals.

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