scholarly journals Determination of recovery efficiency of ¹³⁷Cs in seawaterusing co-precipitation method

2021 ◽  
Vol 10 (1) ◽  
pp. 40-46
Author(s):  
Thang Duong Duc ◽  
Bac Vuong Thu ◽  
Dung Bui Dac ◽  
Thang Duong Van ◽  
Hau Doan Thuy ◽  
...  
Keyword(s):  
Mean Value ◽  
Precipitation Method ◽  
Recovery Efficiency ◽  
Average Recovery ◽  
Seawater Samples ◽  
Co Precipitation

Recovery efficiency of 137Cs in seawater samples with different volumes of 40, 50, 60, 80 and 100 liters using co-precipitation method by ferrocyanide compounds has been determined. 134Cs nuclide was used as a tracer to determine recovery efficiency. The results showed that the recovery efficiency of 134Cs ranged from 92.62% to 99.26% with mean value of (95.22 ± 2.61)% for different sample volumes. Average recovery efficiency for samples with a volume of 50 liters was (95.70 ± 2.50)% and uncertainty when determining 137Cs in seawater samples were still less than 20%. Therefore, reducing the volume of sample to 50 liters still ensures reliability when determining 137Cs in seawater samples by co-precipitation method, thereby reducing the chemical and time when analyze a large number of samples.

A Modified Microbiological Method for Determination of Folate Levels in Erythrocyte and Plasma

Pteridines ◽  
2007 ◽  
Vol 18 (1) ◽  
pp. 106-113 ◽  
Author(s):  
Hande Sipahi ◽  
Terken Baydar ◽  
Meral Ozalp ◽  
Gonul Sahin
Keyword(s):  
Heterocyclic Compounds ◽  
Normal Component ◽  
Folate Deficiency ◽  
Mean Value ◽  
Microbiological Method ◽  
Average Recovery ◽  
Carbon Transfer ◽  
Erythrocyte Folate ◽  
Methionine Synthesis

Abstract Pteridines are natural heterocyclic compounds and they are generally divided into two main groups which are denominated as conjugated and unconjugated pteridines. Conjugated pteridines are the folate derivatives containing p-aminobenzoate and glutamate. Folate is a normal component of the cell. Folate derivatives play a crucial role in important biochemical pathways such as purine and pyrimidine biosynthesis, conversion of serine to glycine, histidine catabolism, methionine synthesis and detoxification reactions of certain xenobiotics, in which single carbon transfer is required. Folate deficiency has been proven to play a role in the pathogenesis of certain diseases. Additionally, exposure to some xenobiotics and prolonged use of some drugs may lead to folate deficiency. Serum, plasma and especially erythrocyte folate concentrations are generally used as biomarkers of folate pool. Therefore the present study was undertaken to establish an easy applicable, economic, accurate, sensitive, specific and reproducible microbiological method by using L. rhamnosus in our laboratory. Following the establishment of the method its application was carried out in blood samples of 46 volunteers. Mean value of folate levels in erythrocyte were found 359.7 ± 133.3 ng/ml, while mean plasma folate levels were determined 27.3 ± 12.4 ng/ml. In erythrocyte, the average recovery was 103.0 ± 17.7% (mean ±SD), in plasma the average recovery was 101.0 ± 1.7% (mean ±SD) for folinic acid concentrations at 10, 25 and 50 ng/ml. The CVs were 15.1 ± 5.6% (mean ± SD) for within-run and 7.2 ± 3.9% (mean ± SD) for between-run precisions. In the present study, a modified microbiological method for folate analysis which can be applied to biological material, has been established.

Determining europium compositional fluctuations in partially stabilized zirconia nanopowders: a non-line-broadening-based method

2016 ◽  
Vol 72 (1) ◽  
pp. 29-38 ◽  
Author(s):  
Riccardo Marin ◽  
Gabriele Sponchia ◽  
Michele Back ◽  
Pietro Riello
Keyword(s):  
Tetragonal Phase ◽  
Rietveld Analysis ◽  
Lattice Parameters ◽  
Crystalline Lattice ◽  
Precipitation Method ◽  
Stabilized Zirconia ◽  
Partially Stabilized Zirconia ◽  
Log Normal ◽  
Co Precipitation

A method is reported for assessing the compositional fluctuations in a ceramic sample, based only on the determination of the crystalline lattice parameters. Pure tetragonal phase partially stabilized zirconia powders are synthesized through the co-precipitation method by incorporating 4% Eu3+. The powder is subjected to compression cycles to promote the tetragonal-to-monoclinic transformation. The Rietveld analysis of the X-ray powder diffraction patterns, recorded after each compression cycle, gives information about the lattice parameters and monoclinic phase content. The determination of europium content in the residual tetragonal phase is accomplished considering the unit cell volume oft-ZrO2using Vegard's law. Using this information the compositional fluctuations over the sample were determined by considering two possible distributions of lanthanide ion content in the powders: a Gaussian and a Log-normal one. It was found that the Gaussian distribution better fits the experimental data. It was eventually demonstrated that these results are physically meaningful.

Determination of 234U and 238U in seawater samples by alpha spectrometry after concentration of U(VI) onto hydrotalcite and co-precipitation with LaF3

2013 ◽  
Vol 101 (10) ◽  
pp. 621-624
Author(s):  
N. V. Suc ◽  
T. T. Bich
Keyword(s):  
Inductively Coupled Plasma ◽  
Alpha Spectrometry ◽  
Separation Efficiency ◽  
Chemical Separation ◽  
Accurate Method ◽  
Uranium Isotopes ◽  
Inductively Coupled ◽  
Seawater Samples ◽  
Co Precipitation

Summary This paper presents a simple and accurate method for determination of uranium isotopes (234U and 238U) in seawater samples using alpha spectrometry. Uranium is pre-concentrated from seawater samples via adsorption on hydrotalcite at pH 6.5. The absorbent is dissolved into 50 ml of 8M HNO3; then filtered through a Dowex-1 column. U(VI) in the elution solution is reduced to U(IV) using zinc metal in 4M solution of HCl and then co-precipitated with LaF3. The chemical separation efficiency is found to be 97.12±2.68%, eliminating the need of using 232U tracer in other published methods. This method is validated via comparison with results obtained using inductively coupled plasma mass spectrometry (ICP-MS) and neutron activation analysis (NAA) for three seawater samples.

Detection of Circulating Tissue Factor and Factor VII in a Normal Population

1996 ◽  
Vol 75 (05) ◽  
pp. 772-777 ◽  
Author(s):  
Sybille Albrecht ◽  
Matthias Kotzsch ◽  
Gabriele Siegert ◽  
Thomas Luther ◽  
Heinz Großmann ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Normal Population ◽  
Mean Value ◽  
Factor Vii ◽  
Significant Difference ◽  
Age Dependent ◽  
The Mean ◽  
Highly Correlated ◽  
And Gender

SummaryThe plasma tissue factor (TF) concentration was correlated to factor VII concentration (FVIIag) and factor VII activity (FVIIc) in 498 healthy volunteers ranging in age from 17 to 64 years. Immunoassays using monoclonal antibodies (mAbs) were developed for the determination of TF and FVIIag in plasma. The mAbs and the test systems were characterized. The mean value of the TF concentration was 172 ± 135 pg/ml. TF showed no age- and gender-related differences. For the total population, FVIIc, determined by a clotting test, was 110 ± 15% and the factor VIlag was 0.77 ± 0.19 μg/ml. FVII activity was significantly increased with age, whereas the concentration demonstrated no correlation to age in this population. FVII concentration is highly correlated with the activity as measured by clotting assay using rabbit thromboplastin. The ratio between FVIIc and FVIIag was not age-dependent, but demonstrated a significant difference between men and women. Between TF and FVII we could not detect a correlation.

Determination of Plasminogen in Clots and Thrombi

1966 ◽  
Vol 16 (01/02) ◽  
pp. 038-050 ◽  
Author(s):  
Ulla Hedner ◽  
Inga Marie Nilsson ◽  
B Robertson
Keyword(s):  
Mean Value ◽  
Main Mechanism ◽  
Clot Lysis ◽  
Post Mortem ◽  
Digestion Time ◽  
Normal Volunteers ◽  
Casein Solution ◽  
The Mean

SummaryThe plasminogen content was determined by a casein method in plasma and serum from 20 normal volunteers. The mean plasminogen content was found to be 10.1 ACU (the arbitrary caseinolytic unit defined in such a way that using a 3% casein solution and a digestion time of 20 min. at 37°C, 10 ACU gave an extinction of 0.300). No difference between serum and plasma regarding the plasminogen content was found.Plasminogen was determined in drained and drained plus washed clots prepared from 2 ml plasma. The highest values found in the drained clots were 0.9 ACU/clot and 0.2 ACU/clot in the drained plus washed clots.Plasminogen was also determined in drained and drained plus washed clots prepared from plasma with added purified plasminogen. The plasminogen was recovered in the washing fluid. According to these tests, then, purified added plasminogen is washed out of the clots.The plasminogen content of 20 thrombi obtained post mortem was also determined. The mean value was found to be 0.7 ACU/cm thrombus. Judging from our results, the “intrinsic clot lysis theory” is not the main mechanism of clot dissolution.

Magnetic and dielectric properties of BiFeO3 nanoparticles

2015 ◽  
Vol 7 (2) ◽  
pp. 1393-1403
Author(s):  
Dr R.P VIJAYALAKSHMI ◽  
N. Manjula ◽  
S. Ramu ◽  
Amaranatha Reddy
Keyword(s):  
Diffuse Reflectance Spectrum ◽  
Precipitation Method ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
Bifeo3 Nanoparticles ◽  
Transmission Electron ◽  
Multiferroic Bifeo3 ◽  
Pure Phase ◽  
Simple Chemical ◽  
Co Precipitation

Single crystalline nano-sized multiferroic BiFeO3 (BFO) powders were synthesized through simple chemical co-precipitation method using polyethylene glycol (PEG) as capping agent. We obtained pure phase BiFeO3 powder by controlling pHand calcination temperature. From X-ray diffraction studies the nanoparticles were unambiguously identified to have a rhombohedrally distorted perovskite structure belonging to the space group of R3c. No secondary phases were detected. It indicates single phase structure. EDX spectra indicated the appearance of three elements Bi, Fe, O in 1:1:3. From the UV-Vis diffuse reflectance spectrum, the absorption cut-off wavelength of the BFO sample is around 558nm corresponding to the energy band gap of 2.2 eV. The size (60-70 nm) and morphology of the nanoparticles have been analyzed using transmission electron microscopy (TEM).   Linear M−H behaviour and slight hysteresis at lower magnetic field is observed for BiFeO3 nanoparticles from Vibrating sample magnetometer studies. It indicates weak ferromagnetic behaviour at room temperature. From dielectric studies, the conductivity value is calculated from the relation s = L/RbA Sm-1 and it is around 7.2 x 10-9 S/m.

Determination of the Probability Distribution of the Mean Sound Level

2010 ◽  
Vol 35 (4) ◽  
pp. 543-550 ◽  
Author(s):  
Wojciech Batko ◽  
Bartosz Przysucha
Keyword(s):  
Probability Distribution ◽  
Probability Distribution Function ◽  
Mean Value ◽  
Sound Level ◽  
Function Form ◽  
Noise Levels ◽  
Logarithmic Mean ◽  
The Mean ◽  
Estimation Of Uncertainty

AbstractAssessment of several noise indicators are determined by the logarithmic mean <img src="/fulltext-image.asp?format=htmlnonpaginated&src=P42524002G141TV8_html\05_paper.gif" alt=""/>, from the sum of independent random resultsL1;L2; : : : ;Lnof the sound level, being under testing. The estimation of uncertainty of such averaging requires knowledge of probability distribution of the function form of their calculations. The developed solution, leading to the recurrent determination of the probability distribution function for the estimation of the mean value of noise levels and its variance, is shown in this paper.

Exploring the characterization of Ni doped MgO nanoparticles using co-precipitation method

2020 ◽  
Vol 3 (1) ◽  
pp. 30-33
Author(s):  
Muthulakshmi M ◽  
Madhumitha G
Keyword(s):  
Magnesium Oxide ◽  
Analytical Techniques ◽  
Nickel Chloride ◽  
Precipitation Method ◽  
Crystalline Powder ◽  
High Melting Point ◽  
Design Synthesis ◽  
Mgo Nanoparticles ◽  
Co Precipitation

Nanotechnology is a field of applied science focused on design, synthesis and characterization of nanomaterials. The nickel and magnesium have improved their applications in transparent electrodes and nano electronics. In addition, magnesium oxide has moisture resistance and high melting point properties. In the present work has been carried out in the development of green crystalline powder of nickel doped magnesium oxide nanoparticles by Co-precipitation method, from the mixture of nickel chloride and magnesium chloride with KOH as solvent. From the XRD results, crystalline size of the particle can be observed. Spherical structure of Ni doped MgO nanoparticles were indicated by SEM results and powdered composition of samples were obtained from FTIR. EDAX represents the peak composition of the nanoparticle. The above analytical techniques have confirmed that the Ni doped MgO nanoparticles obtained from the mixture of NiCl2 and MgCl2.

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