Computational Studies of Contact Time Dependence of Adhesive Energy Due to Redistribution of the Locations of Strong Specific Interfacial Interactions

2004 ◽  
Vol 37 (15) ◽  
pp. 5800-5806 ◽  
Author(s):  
Arlette R. C. Baljon ◽  
Joris Vorselaars ◽  
Travis J. Depuy
Keyword(s):  
Time Dependence ◽  
Contact Time ◽  
Computational Studies ◽  
Interfacial Interactions ◽  
Adhesive Energy

Material-related contact time dependence of adhesion force revealed by an AFM cantilever in a humid environment

2021 ◽  
Vol 550 ◽  
pp. 149357
Author(s):  
Tianmao Lai ◽  
Yuguo Chen ◽  
Jianchao Sun ◽  
Mingli Guo
Keyword(s):  
Time Dependence ◽  
Contact Time ◽  
Adhesion Force ◽  
Humid Environment ◽  
Afm Cantilever

scholarly journals Experimental and computational studies on activated Bambara groundnut (Vigna subterranean) hulls for the adsorptive removal of herbicides from aqueous solution

2021 ◽  
Vol 45 (1) ◽  
Author(s):  
Thomas Aondofa Nyijime ◽  
Abdullahi Muhammad Ayuba ◽  
Habibat Faith Chahul
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Quantum Chemical ◽  
Contact Time ◽  
Adsorption Process ◽  
Bambara Groundnut ◽  
Batch Adsorption ◽  
Computational Studies ◽  
Initial Concentration ◽  
Equilibrium Data

Abstract Background The excessive usage of herbicides to control herbs by farmers has become an issue of interest to the environmentalist due to the threat posed by such act to the ecosystem, and therefore, there is the need to curb such practices. The efficiency of Bambara groundnut shell for the removal of pendimethalin (PE) and paraquat dichloride (PQ) herbicides from aqueous solution was established in this work. The activated carbon was prepared via chemical activation method using trioxonitrate (v) acid by determining its void volume, moisture content, bulk density and Fourier transform infrared (FTIR) and scanning electron microscopy (SEM) methods. Batch adsorption techniques were set to optimize the adsorption parameters such as solution pH, adsorbate concentration, contact time, adsorbent dosage and temperature in order to depict the best optimal conditions for the adsorption process. The adsorption process was examined in terms of its equilibrium data, kinetics, thermodynamics involved in the adsorption process as well as computational quantum chemical parameters evaluation. Results The batch adsorption experiments revealed that the amounts of PE and PQ adsorbed were found to vary with the contact time, adsorbent dosage, pH and initial concentration. The adsorption of PE and PQ decreased with increasing adsorbent dose but increases with increasing initial concentration of the PE and PQ solution. Isotherm studies revealed that the equilibrium data fitted to both Langmuir and Freundlich model with R-squared values of 0.976, 0.993 and 0.909, 0.978 for PE and PQ, respectively, which implied that Langmuir isotherm had a better fit. This was also found to be an indication that the uptake of PE and PQ by ACBGNS occurred through monolayer adsorption on identical homogenous sites. Also, kinetic modeling results obtained showed that the pseudo-second-order model explained the adsorption kinetics of PE and PQ by ACBGNS best, which meant that chemisorption was the slowest step and, thus, the rate determining step. The positive value of ΔH and the positive value of ΔG show the endothermic and spontaneous nature of adsorption of PE and PQ ACBGNS. Conclusion Batch adsorption experiment and characterization of the ACBGNS have indicated that Bambara ground nut shell can be used to produce activated carbon that can be applied effectively for adsorption of PE and PQ from an aqueous solution. Computational studies results obtained from quantum chemical analysis are consistent with the experimental results obtained from this study.

scholarly journals Towards Improved Social Distancing Guidelines: Space and Time Dependence of Virus Transmission from Speech-driven Aerosol Transport Between Two Individuals

2020 ◽  
Author(s):  
Fan Yang ◽  
Amir A. Pahlavan ◽  
Simon Mendez ◽  
Manouk Abkarian ◽  
Howard A. Stone
Keyword(s):  
Time Dependence ◽  
Contact Time ◽  
Air Flow ◽  
Infected Individual ◽  
Virus Transmission ◽  
Susceptible Individual ◽  
Aerosol Transport ◽  
Social Distancing ◽  
Space And Time

It is now recognized that aerosol transport contributes to the transmission of the SARS-CoV-2 virus. Here we improve existing social distancing guidelines for airborne pathogens, which are typically given in terms of distance with vague statements (if any) about contact times. Also, estimates of inhalation of virus in a contaminated space usually assume a well-mixed environment, which is realistic for some, but not all, situations. In particular, we consider a local casual interaction of an infected individual and a susceptible individual, both maskless, account for the air flow and aerosol transport characteristics of speaking and breathing, and propose social distancing guidelines that involve both space and contact time, based on a conservative model of the interactions.

scholarly journals Effect of interfacial interactions on the electromechanical response of poly(vinylidene fluoride-trifluoroethylene)/BaTiO3 composites and its time dependence after poling

2015 ◽  
Vol 114 ◽  
pp. 103-109 ◽  
Author(s):  
Sara Dalle Vacche ◽  
Yves Leterrier ◽  
Véronique Michaud ◽  
Dragan Damjanovic ◽  
Arthur B. Aebersold ◽  
...  
Keyword(s):  
Time Dependence ◽  
Vinylidene Fluoride ◽  
Interfacial Interactions ◽  
Poly Vinylidene Fluoride

The O–C diagrams of minor planets − a new approach to modelling the rotation

1999 ◽  
Vol 173 ◽  
pp. 185-188
Author(s):  
Gy. Szabó ◽  
K. Sárneczky ◽  
L.L. Kiss
Keyword(s):  
Error Analysis ◽  
Time Dependence ◽  
Theoretical Work ◽  
Minor Planet ◽  
Minor Planets ◽  
New Approach ◽  
Preliminary Results ◽  
Ccd Observations

AbstractA widely used tool in studying quasi-monoperiodic processes is the O–C diagram. This paper deals with the application of this diagram in minor planet studies. The main difference between our approach and the classical O–C diagram is that we transform the epoch (=time) dependence into the geocentric longitude domain. We outline a rotation modelling using this modified O–C and illustrate the abilities with detailed error analysis. The primary assumption, that the monotonity and the shape of this diagram is (almost) independent of the geometry of the asteroids is discussed and tested. The monotonity enables an unambiguous distinction between the prograde and retrograde rotation, thus the four-fold (or in some cases the two-fold) ambiguities can be avoided. This turned out to be the main advantage of the O–C examination. As an extension to the theoretical work, we present some preliminary results on 1727 Mette based on new CCD observations.

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