scholarly journals Application of the Laser Interferometry in Studies of Biophysical Model Systems

2013 ◽  
Vol 36 (1) ◽  
pp. 1-5
Author(s):  
Sławomir Wąsik

Abstract In this paper some selected applications of laser interferometry method in studies of biophysical model systems are presented. With the aid of a laser interferometric method, specific experiments were performed, which confirm that the gravitational field significantly modifies the amount of transported substance and affects the concentration profiles as well as the time evolution of the concentration field. The laser interferometry was also used to investigation of diffusion of antibiotics (ciprofloxacin or ampicillin) into the water phase from mixtures of neutral or negatively charged liposomes, and antibiotic-liposome interactions. Differences in the diffusion kinetics of ciprofloxacin and ampicillin from liposomal solutions to the water phase were observed. Moreover, the amount of ampicillin and ciprofloxacin released from the anionic liposomal phase was higher than that from the neutral one.

2015 ◽  
Vol 37 (1) ◽  
pp. 43-47
Author(s):  
Sławomir Wąsik ◽  
Michał Arabski ◽  
Karolina Maciejec ◽  
Grażyna Suchanek ◽  
Anna Świercz

The objective of the present study has been to test the laser interferometry method in terms of its usability for investigating sorption properties of minerals. This method was used to test the absorption capacity of halloysite with reference to glucose, which is often found in industrial wastewater and whose excess can disturb the environmental eco-balance. The sorption capacity of halloysite was thus determined indirectly, basing on the comparison of concentration profiles as well as time characteristics of glucose quantities released from the control solution and from the solution incubated with a halloysite adsorbent. An analysis of glucose diffusion was conducted in a two-chamber membrane system. On the basis of the obtained concentration profiles, the evolution of the concentration field was determined; so were the removal efficiency (%) and the amount of glucose adsorbed at equilibrium (qe, mg/g). The obtained results confirm good sorption properties of halloysite with respect to the investigated substance as well as usability of the method for this kind of investigations. The presented tests suggest that the measurement set-up can be optimised in such as way that visual rendering and testing the kinetics of the adsorbed substance direct release from the studied material become possible.


1988 ◽  
Vol 20 (11-12) ◽  
pp. 167-173 ◽  
Author(s):  
S. E. Strand ◽  
R. M. Seamons ◽  
M. D. Bjelland ◽  
H. D. Stensel

The kinetics of methane-oxidizing bioreactors for the degradation of toxic organics are modeled. Calculations of the fluxes of methane and toxic chlorinated hydrocarbons were made using a biofilm model. The model simulated the effects of competition by toxics and mediane on their enzymatic oxidation by the methane monooxygenase. Dual-competitive-substrate/diffusion kinetics were used to model biofilm co-metabolism, integrating equations of the following form:where S1 and S2 are the local concentrations of methane and toxic compound, respectively, and r and K are the maximum uptake rates and Monod coefficients, and x is the distance into the biofilm.


2021 ◽  
Vol 125 (10) ◽  
pp. 2069-2076
Author(s):  
Brendan C. Sweeny ◽  
David C. McDonald ◽  
Nicholas S. Shuman ◽  
Albert A. Viggiano ◽  
Juergen Troe ◽  
...  

2003 ◽  
Author(s):  
Shibin Wang ◽  
Jingwei Tong ◽  
Mario Cottron ◽  
Linan Li ◽  
Zhiyong Wang

1991 ◽  
Vol 238 ◽  
Author(s):  
G. J. Shiflet

ABSTRACTStresses are introduced in crystals at interphase boundaries where steps improve the registry of atoms. A model and mathematical analysis based on an approach previously taken by van der Merwe and Shiflet1–4 of the problem incorporating a coherent step are presented. Computed distributions of stresses, strains, dilatation and energy density in the form of contours and nets are given for a coherent monatomic step. It is concluded that the maximum stresses are quite large and the fields decay fairly rapidly with distance from the steps, the gradient of dilatation around steps will significantly affect diffusion kinetics of impurities and the strain energy seems too low to significantly enhance chemical processes.


Author(s):  
Francisco de Assis Andrade Barbosa ◽  
Gilder Nader ◽  
Ricardo Tokio Higuti ◽  
Cláudio Kitano ◽  
Emílio Carlos Nelli Silva

Laser interferometry is a well-established technique for the characterization of piezoelectric actuators. In this work, by using a low cost Michelson interferometer, the measurement of the calibration factor and the displacement amplification of a novel piezoelectric flextensional actuator (PFA), designed by using the topology optimization method, is performed. A simple method, based on small phase modulation depth when the PFA is driven by a triangular waveform, allows the absolute interferometer calibration. The free-displacement of the PFA for various drive voltages is measured and the displacement amplification is determined. The linearity and frequencyresponse of the PFA are evaluated up to 20 kHz


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