Determination of micelle size and polydispersity by fluorescence quenching. Experimental results

1986 ◽  
Vol 82 (6) ◽  
pp. 1829 ◽  
Author(s):  
Gregory G. Warr ◽  
Franz Grieser ◽  
D. Fennell Evans
Keyword(s):  
Fluorescence Quenching ◽  
Experimental Results ◽  
Micelle Size

Determination of Charge Coefficient of Piezoelectric Films Using a Combined Finite Element Model and Dynamic Loading Technique

2020 ◽  
Vol 835 ◽  
pp. 229-242
Author(s):  
Oboso P. Bernard ◽  
Nagih M. Shaalan ◽  
Mohab Hossam ◽  
Mohsen A. Hassan
Keyword(s):  
Finite Element ◽  
Dynamic Loading ◽  
Material Properties ◽  
Accurate Determination ◽  
Substrate Material ◽  
Experimental Results ◽  
Piezoelectric Composite ◽  
Piezoelectric Film ◽  
Piezoelectric Charge

Accurate determination of piezoelectric properties such as piezoelectric charge coefficients (d33) is an essential step in the design process of sensors and actuators using piezoelectric effect. In this study, a cost-effective and accurate method based on dynamic loading technique was proposed to determine the piezoelectric charge coefficient d33. Finite element analysis (FEA) model was developed in order to estimate d33 and validate the obtained values with experimental results. The experiment was conducted on a piezoelectric disc with a known d33 value. The effect of measuring boundary conditions, substrate material properties and specimen geometry on measured d33 value were conducted. The experimental results reveal that the determined d33 coefficient by this technique is accurate as it falls within the manufactures tolerance specifications of PZT-5A piezoelectric film d33. Further, obtained simulation results on fibre reinforced and particle reinforced piezoelectric composite were found to be similar to those that have been obtained using more advanced techniques. FE-results showed that the measured d33 coefficients depend on measuring boundary condition, piezoelectric film thickness, and substrate material properties. This method was proved to be suitable for determination of d33 coefficient effectively for piezoelectric samples of any arbitrary geometry without compromising on the accuracy of measured d33.

scholarly journals A parametric prediction of the Young’s modulus of polymers enhanced with ΜWCNTs

2018 ◽  
Vol 233 ◽  
pp. 00025
Author(s):  
P.V. Polydoropoulou ◽  
K.I. Tserpes ◽  
Sp.G. Pantelakis ◽  
Ch.V. Katsiropoulos
Keyword(s):  
Young’S Modulus ◽  
Elastic Properties ◽  
Young's Modulus ◽  
Experimental Results ◽  
Scale Model ◽  
Fe Model ◽  
Multi Scale ◽  
Unit Cells ◽  
Random Dispersion

In this work a multi-scale model simulating the effect of the dispersion, the waviness as well as the agglomerations of MWCNTs on the Young’s modulus of a polymer enhanced with 0.4% MWCNTs (v/v) has been developed. Representative Unit Cells (RUCs) have been employed for the determination of the homogenized elastic properties of the MWCNT/polymer. The elastic properties computed by the RUCs were assigned to the Finite Element (FE) model of a tension specimen which was used to predict the Young’s modulus of the enhanced material. Furthermore, a comparison with experimental results obtained by tensile testing according to ASTM 638 has been made. The results show a remarkable decrease of the Young’s modulus for the polymer enhanced with aligned MWCNTs due to the increase of the CNT agglomerations. On the other hand, slight differences on the Young’s modulus have been observed for the material enhanced with randomly-oriented MWCNTs by the increase of the MWCNTs agglomerations, which might be attributed to the low concentration of the MWCNTs into the polymer. Moreover, the increase of the MWCNTs waviness led to a significant decrease of the Young’s modulus of the polymer enhanced with aligned MWCNTs. The experimental results in terms of the Young’s modulus are predicted well by assuming a random dispersion of MWCNTs into the polymer.

A Technique for the Laboratory Determination of Recirculation in Single Needle Dialysis

1993 ◽  
Vol 16 (2) ◽  
pp. 63-70 ◽  
Author(s):  
N.A. Hoenich ◽  
P.T. Smirthwaite ◽  
C. Woffindin ◽  
P. Lancaster ◽  
T.H. Frost ◽  
...  
Keyword(s):  
Experimental Data ◽  
Flow Rate ◽  
Experimental Results ◽  
New Technique ◽  
Treatment Efficiency ◽  
Single Lumen ◽  
Theoretical Predictions ◽  
Lumen Catheter ◽  
A New Technique

Recirculation is an important factor in single needle dialysis and, if high, can compromise treatment efficiency. To provide information regarding recirculation characteristics of access devices used in single needle dialysis, we have developed a new technique to characterise recirculation and have used this to measure the recirculation of a Terumo 15G fistula needle and a VasCath SC2300 single lumen catheter. The experimentally obtained results agreed well with those established clinically (8.5 ± 2.4% and 18.4 ± 3.4%). The experimental results have also demonstrated a dependence on access type, pump speeds and fistula flow rate. A comparison of experimental data with theoretical predictions showed that the latter exceeded those measured with the largest contribution being due to the experimental fistula.

A Homogeneous Nonisotopic Histone Deacetylase Activity Assay

2003 ◽  
Vol 8 (1) ◽  
pp. 89-95 ◽  
Author(s):  
Birgit Heltweg ◽  
Manfred Jung
Keyword(s):  
Drug Discovery ◽  
Fluorescence Quenching ◽  
Histone Deacetylase ◽  
Anticancer Agents ◽  
Histone Deacetylases ◽  
Activity Assay ◽  
Animal Testing ◽  
Hdac Activity

Histone deacetylases (HDACs) are important regulators of transcription, and their inhibitors are a promising class of anticancer agents. The methods for the determination of HDAC activity and its inhibition that are currently available suffer from various drawbacks, such as animal testing, radioactive substrates, or limited throughput. Therefore, a fast nonisotopic method for the measurement of HDAC activity is highly desirable. The authors present such an assay that relies on the fluorescent HDAC substrate developed previously in their group. After incubation of the substrate with the enzyme, a derivatization leads to efficient fluorescence quenching in the deacetylated metabolite. Thus, only the fluorescence emitted by the remaining substrate is detected, which allows for a convenient detection of HDAC activity in a homogeneous format that can be performed on multiwell plate readers. This procedure, called HDASH (histone deacetylase assay—homogeneous), should be a valuable tool in transcriptional research and especially drug discovery. ( Journal of Biomolecular Screening 2003:89-95)

Determination of Sodium Hexametaphosphate in Beverages Based on the Fluorescence Quenching of Acridine Orange

2014 ◽  
Vol 47 (16) ◽  
pp. 2740-2746
Author(s):  
Heng Xin Zhao ◽  
Ming Luo ◽  
Li Xin Mo ◽  
Liang Cheng ◽  
Zheng Ma ◽  
...  
Keyword(s):  
Fluorescence Quenching ◽  
Acridine Orange ◽  
Sodium Hexametaphosphate

Optimization of a Specimen Size for the Determination of the Diffusible Hydrogen Content in Metals

2014 ◽  
Vol 698 ◽  
pp. 466-471
Author(s):  
Oleg V. Panchenko ◽  
Alexey M. Levchenko ◽  
Victor A. Karkhin
Keyword(s):  
Hydrogen Content ◽  
Calculation Method ◽  
Specimen Size ◽  
Experimental Results ◽  
Diffusible Hydrogen ◽  
Measuring Methods ◽  
Deposited Metal ◽  
Calculation Results

Specimens of various sizes are used to determine hydrogen content in deposited metals in such standards as ISO 3690, AWS A 4.3, and GOST 23338 while measuring methods are the same. It causes problems in comparison of experimental results and brings up the following question: what kind of specimen size is optimal to determine hydrogen content? An optimal specimen size was estimated using a calculation method. Experimental and calculation results obtained by using specimens with estimated dimensions were compared to the results obtained by using the specimen with dimensions of 100*25*8 mm to determine hydrogen content in a deposited metal.

Spectroscopie par Source Laser. IV. Application de la Théorie d'Anderson au Calcul des Largeurs des Raies de la Transition 10°0–00°1 de N2O. Influence de l'Octupôle sur la Détermination du Moment Quadrupolaire de N2O

1973 ◽  
Vol 51 (6) ◽  
pp. 605-609 ◽  
Author(s):  
C. Boulet ◽  
N. Lacome ◽  
P. Isnard
Keyword(s):  
Quadrupole Moment ◽  
Experimental Results ◽  
Molecular Parameters ◽  
Line Widths

From the analysis of the available experimental results, a vibrational dependence of N2O line widths is shown, which can be explained, applying the Anderson–Tsao–Curnutte theory. But no dependence on ν of any of the molecular parameters can be deduced. In the last part, we have pointed out the effect on the determination of the quadrupole moment of assuming a nonvanishing octupole moment for N2O.

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