The use of erbium fiber laser relaxation frequency for sensing refractive index and solute concentration of aqueous solutions

2008 ◽  
Vol 5 (11) ◽  
pp. 825-829 ◽  
Author(s):  
H. Arellano-Sotelo ◽  
Yu.O. Barmenkov ◽  
A.V. Kir'yanov
2008 ◽  
Author(s):  
Héctor Arellano-Sotelo ◽  
Yuri O. Barmenkov ◽  
Alexander V. Kir’yanov ◽  
Cristiano M. B. Cordeiro ◽  
Christiano J. S. de Matos

Cold neutron inelastic scattering experiments have been performed on dilute aqueous solutions of (CD 3 ) 3 COH and of solutions of (CH 3 ) 3 COH in D 2 O at 21 °C. From the broadening of the quasi-elastic peak and independently determined self-diffusion coefficients ( D ), diffusive lifetimes ( c ) of H 2 O molecules have been calculated as functions of solute concentration. The product Dc is insensitive to concentration, giving a mean diffusion step length of 0.14 nm. The inelastic portion of the spectrum, reflecting lattice-like hydrogen bonding modes indicates that the solute enhances the water ‘structure’ but that such structure bears no resemblance to ice.


2021 ◽  
Vol 32 ◽  
Author(s):  
Binh Pham Thanh ◽  
Thuy Van Nguyen ◽  
Van Hoi Pham ◽  
Huy Bui ◽  
Thi Hong Cam Hoang ◽  
...  

In this paper, we report a new type of refractometer based on a D-shaped fiber Bragg grating (FBG) integrated in a loop-mirror optical fiber laser. This proposed sensor is used in wavelength interrogation method, in which the D-shaped FBG is applied as a refractive index (RI) sensing probe and a mirror to select mode of laser. The D-shaped FBG is prepared by the removal of a portion of the fiber cladding covering the FBG by means of side-polishing technique. The D-shaped FBG sensing probe integrated in a loop-mirror optical fiber laser with saturated pump technique, the characteristics of sensing signals have been improved to obtain stable intensity, narrower bandwidth and higher optical signal-to-noise ratio compare to normal reflection configuration. The limit of detection (LOD) of this sensor can be achieved to 2.95 x 10-4 RIU in the refractive index (RI) range of 1.42-1.44. Accordingly, we believe that the proposed refractometer has a huge potential for applications in biochemical-sensing technique.


2016 ◽  
Vol 8 (5) ◽  
pp. 1-8 ◽  
Author(s):  
Junfa Zhao ◽  
Juan Wang ◽  
Cheng Zhang ◽  
Cuijuan Guo ◽  
Hua Bai ◽  
...  

2000 ◽  
Vol 28 (3) ◽  
pp. 282-283 ◽  
Author(s):  
T. L. Narrow ◽  
M. Yoda ◽  
S. I. Abdel-Khalik

1967 ◽  
Vol 6 (47) ◽  
pp. 663-679 ◽  
Author(s):  
P. K. Rohatgi ◽  
C. M. Adams

Dendritic aggregates of ice and brine formed upon freezing of aqueous solutions have been studied. Chlorides of sodium, potassium, lithium and hydrogen were used as solutes; structures produced on freezing of binary, ternary and quaternary solutions were examined. Effects of freezing rate, solute concentration, solute diffusivity, mixing of solutions and magnetic fields are reported. The spacing between ice platelets or dendrites was found experimentally to be proportional to the square root of the freezing time when the freezing rate was constant from beginning to end of solidification. During unidirectional freezing from a constant temperature chill, the solution at each location is subjected to a spectrum of freezing rates; dendrite spacing increases linearly with distance from the chill surface and it is inversely proportional to the square root of the maximum freezing rate. In binary solutions dendrite spacing increases linearly with solute concentration; above a critical solute concentration ice platelets develop side branches. Application of an external magnetic field has an effect similar to increasing concentration. At a given solute concentration, spacing between ice dendrites increases linearly with solute diffusivity. In ternary and quaternary solutions dendrite spacing is a function of the concentrations and diffusivities of each of the constituent solutes.


2009 ◽  
Vol 6 (3) ◽  
pp. 729-736 ◽  
Author(s):  
P. Panneerselvam ◽  
V. Sathya Selva Bala ◽  
N. Thinakaran ◽  
P. Baskaralingam ◽  
M. Palanichamy ◽  
...  

The sorptive removal of nickel ion from aqueous solutions using modified ZSM-5 zeolites was investigated. Experiments were carried out as a function of solute concentration and different temperatures. Mesoporous material of ZSM-5 zeolite was modified with phosphoric acid by wet method. The modified zeolite was converted to Na+form using aqueous NaHCO3solution. The Na+form of modified zeolite, represented as PNa2--ZSM-5 was characterized by XRD, BET, SEM and AAS techniques. It was then tested for ion exchange with aqueous Ni(SO4) solution. The Ni2+content of the solution was analyzed by AAS. Phosphoric acid modified PNa2--ZSM-5 zeolite shows higher adsorption capacity than the parent Na-Y zeolite. Equilibrium modeling data were fit to linear Langmuir model then the Freundlich model. These parameter confirmed that sorption of Ni2+is feasible spontaneous and endothermic.


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