scholarly journals Silver Cation Coordination Study to AsW9 Ligand – A Trilacunar Arsenotungstate Compound

2017 ◽  
Vol 63 (2) ◽  
pp. 70-72
Author(s):  
Lavinia Berta ◽  
Andrei Gâz ◽  
Francisc Boda ◽  
Augustin Curticapean
Keyword(s):  
Graphical Method ◽  
Ph Value ◽  
Building Blocks ◽  
Silver Cation ◽  
Molar Ratio ◽  
Equivalence Point ◽  
Tetrahedral Geometry ◽  
Sandwich Type ◽  
Preliminary Study ◽  
Cation Coordination

Abstract Objective: The main objective of this research is to find the coordination ratio between AsW9 and Ag+, as a preliminary study for synthesizing a new silver-arsenotungstate complex. Material and method: The ligand:cation molar ratio in complexes was determined by conductometric and potentiometric titrations of AsW9 with silver salts: CH3COOAg, AgNO3. Results: The ratio was obtained from the inflexion points of the curves when molar ratio was plotted versus conductivity, or from the equivalence point when silver added volume was plotted versus pH value. Each graphic shows one point of inflexion corresponding to 1:1.54 ratio of AsW9:Ag+. In the same manner, the equivalent volumes determined by graphical method gave the ratio 1:1.53. The spectral results confirmed that a AsW9:Ag+ complex was formed since the ligand absorption maxima values have been changed from 190 nm to 197 nm in the case of using AgNO3 and 196 nm for CH3COOAg corresponding to the W=Od bond, and from 246.5 nm to 274 nm (AgNO3) and 270 nm (CH3COO-Ag+) for the W-Ob,c-W bond. Conclusions: Silver cation exhibit a preference for AsW9 in a ratio of 3 to 2. This ratio can be associated to a sandwich type arrangement, with two trilacunary Keggin building blocks incorporating 3 metal cations in a tetrahedral geometry.

A New Method for Plasminogen Standardization

1968 ◽  
Vol 20 (03/04) ◽  
pp. 548-554
Author(s):  
J Gajewski ◽  
G Markus
Keyword(s):  
Proteolytic Activity ◽  
Specific Activity ◽  
Molar Ratio ◽  
Sharp Transition ◽  
Equivalence Point ◽  
Constant Amount ◽  
Residual Level ◽  
Activity Measurements ◽  
Complete Saturation ◽  
Human Plasminogen

SummaryA method for the standardization of human plasminogen is proposed, based on the stoichiometric interaction between plasminogen and streptokinase, resulting in inhibition of proteolytic activity. Activation of a constant amount of plasminogen with increasing amounts of streptokinase yields linearly decreasing activities, as a function of streptokinase, with a sharp transition to a constant residual level. The point of transition corresponds to complete saturation of plasmin with streptokinase in a 1:1 molar ratio, and is therefore a measure of the amount of plasminogen present initially, in terms of streptokinase equivalents. The equivalence point is independent of the kind of protein substrate used, buffer, pH, length of digestion and, within limits, temperature. The method, therefore, is not subject to the variations commonly encountered in the usual determination based on specific activity measurements.

Effect of Hydrated Metal Salts on the Coordination Product of Cobalt(II) halide and PNP Type Ligand, 2,6-bis(di-tertbutylphosphinomethyl) pyridine

2018 ◽  
Author(s):  
Tasneem Siddiquee ◽  
Abdul Goni
Keyword(s):  
Metal Salts ◽  
Molar Ratio ◽  
Pincer Complexes ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
Pincer Ligand ◽  
Tetrahedral Geometry ◽  
X Ray ◽  
Distorted Tetrahedral Geometry ◽  
Cobalt Center

Chemical treatment of CoX<sub>2</sub><b><sup>. </sup></b>6H<sub>2</sub>O (X = Cl, Br, I) with the potentially tridentate PNP pincer ligand 2,6-bis(di-<i>tert</i>-butylphosphinomethyl)pyridine in 1:1 molar ratio results in cobalt(II) halide-PNP pincer complexes. The effect of the hydrated metal source on molecular structure and geometry of the complexes was studied by single crystal X-ray diffraction analysis. The complexes are neutral and the cobalt center adopts a penta-coordinate system with potential atropisomerization. Within the unit cell there are two distinct molecules per asymmetric unit. One of the two phosphorus atoms in the PNP ligand was observed to be partially oxidized to phosphinoxide. Disorder in the structure reflects a mixture of square pyramidal and distorted tetrahedral geometry.

Controlled Synthesis of Different Morphologies of SrWO4 Crystals via a Surfactant-Assisted Hydrothermal Precipitation Method

2013 ◽  
Vol 785-786 ◽  
pp. 449-454
Author(s):  
Yan Zhao ◽  
Chun Yan Wu ◽  
Dan Qin ◽  
Xin Lai ◽  
Si Wu ◽  
...  
Keyword(s):  
Ph Value ◽  
Precipitation Method ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Experimental Parameters ◽  
Infrared Spectrometer ◽  
Luminescent Spectra ◽  
Hydrothermal Precipitation ◽  
Surfactant Assisted

SrWO4 octahedrons, flowers, bundles, ellipsoids and dendrites had been successfully synthesized via surfactant-assisted method. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), photo-luminescent spectra techniques (PL) and fourier transrform infrared spectrometer (FTIR). By through various comparison experiments, it can be found that some related experimental parameters including the reagent concentration, [Sr2+]/[WO42-] molar ratio (R), aging temperature and the pH value had great influences on morphology of the products.

Study on the Radiosensitizing Applications of Gold Nanoparticles

2016 ◽  
Vol 851 ◽  
pp. 26-30 ◽  
Author(s):  
Chang Shu Tsai ◽  
Jou Kang Hsiao
Keyword(s):  
Gold Nanoparticles ◽  
Ph Value ◽  
Trisodium Citrate ◽  
Molar Ratio ◽  
Human Breast ◽  
X Ray ◽  
Vis Spectroscopy ◽  
M Phase ◽  
Redox Method ◽  
20 Nm

Citrate-coated gold nanoparticles (AuNPs) were prepared by using redox method and its characterization was studied thoroughly. In the preparation process, the varieties of factors were examined by TEM morphology, DLS zetasizer, XPS analysis and UV-Vis spectroscopy for evaluating their qualities and stability. The experimental results obtained under optimal condition, which are 100±5°C of reaction temperature, 4.5-6.4 of the pH value, 2-10 of molar ratio between trisodium citrate and tetrachloroauric acid, respectively. The fluorescent intensities of DCFDA-stain indicate the amount of generated ROS (reactive oxygen species) by AuNPs. The cell cycle for MDA-MB-231 human breast cancer cells exhibits S-phase arrest which can prevent mitosis. The radiosensitizing effect of AuNPs with 20 nm diameter in MDA-MB-231 was investigated by RCGG values (ratio of cell numbers in the G2/M phase to the G0/G1 phase, RCGG) and its radiosensitizing efficiency was ca. 2.29 to 3.75 fold. In this study, it was found that the radiosensitizing efficiency is related to the cytotoxicity by AuNPs. After the irradiation by x-ray to cells, the enhancement value in the presence of 20 nm diameter AuNPs were 17.2% for 3 Gy and 18.9% for 7 Gy respectively. Compared to the irradiated group alone, the enhancements values were 21.8% and 19.7, respectively.

Parameters Control for Properties of Ferrofluid Used in Series Ferrofluid Sensor

2012 ◽  
Vol 248 ◽  
pp. 594-598
Author(s):  
Gang Zhao ◽  
Hai Rong Cui ◽  
Qiu Li Ding ◽  
Xu Feng Wang ◽  
Shi Xi Tian ◽  
...  
Keyword(s):  
Magnetization Curve ◽  
Ph Value ◽  
Nano Particles ◽  
Molar Ratio ◽  
Magnetic Intensity ◽  
Iron Ion ◽  
Ferrous Chloride ◽  
Bivalent Iron ◽  
In Series ◽  
Magnetic Nano Particles

Series ferrofluid based sensors are novel sensors which use ferrofluid as inductive core to measure signals. The physical properties of ferrofluid affect mostly on performance parameter of these series sensors. There is several generality regularity for ferrofluid appliedd in series sensors. This paper analyses the generality of parameter controlling for properties of ferrofluid used in series ferrofluid sensors. The working area of magnetization curve of ferrofluid used in series sensors should be in its linear area where the permeability of ferrofluid is considered as a constant. The magnetic nano-particles generally obtained by reaction of ferrous chloride and ferric chloride. With the increment of viscosity and density of ferrofluid, the saturation magnetic intensity of ferrofluid increases. The concentration of reacted solution is better to be 0.6mol/L. Saturation magnet intensity of magnetic nano-partcles is highest as the molar ratio of trivalent iron ion to bivalent iron ion is equal to 1.75. The reacted temperature is better between 65~80°C while PH value of solution is in a weak alkaline state.

Catalytic Hydrolysis of Hydrogen Cyanide on Cu-Al Catalyst

2015 ◽  
Vol 1094 ◽  
pp. 15-19
Author(s):  
Lin Xia Yan ◽  
Sen Lin Tian ◽  
Qiu Lin Zhang
Keyword(s):  
Calcination Temperature ◽  
Hydrogen Cyanide ◽  
Influence Factor ◽  
Ph Value ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Cu Content ◽  
Co Precipitation ◽  
The Impact ◽  
Hydrolysis Of

Cu-Al catalysts were synthesized by the co-precipitation method to study hydrolysis of hydrogen cyanide. During the synthesis, the impact of Cu/Al molar ratio, pH value and calcination temperature was investigated and the best synthesis condition was found. The results indicate that the remove of hydrogen cyanide first increases and then decreases with increasing Cu/Al molar ratio, pH value and calcination temperature, which reaches the maxima and remains above 95% at 360 min when Cu/Al molar ratio is 2:1, pH value is approximately 8.0 and calcination temperature is 400°C around. The analysis of X-ray diffraction (XRD) shows that Cu content is the main influence factor at Cu/Al molar ratio below 2:1 whereas crystallinity of catalysts is the key factor at Cu/Al molar ratio above 2:1.

scholarly journals Preliminary Study of Contamination Wastewater on Environment in Slaughterhouse of Merauke City

2018 ◽  
Vol 73 ◽  
pp. 05018
Author(s):  
Nurcholis ◽  
Dirwan Muchlis
Keyword(s):  
Waste Water ◽  
Wastewater Treatment ◽  
Data Analysis ◽  
Microbial Contamination ◽  
Ph Value ◽  
Quality Standard ◽  
Field Observations ◽  
E Coli ◽  
Preliminary Study ◽  
Water Waste

The purpose of this research is to know the contamination of waste water that happened in slaughterhouse (RPH) city of merauke. Data were obtained based on surveys and field observations and the sample used was RPH water waste each in repeat as many as 6 replications. Data analysis was done descriptively by comparing the result obtained with the standard of quality which have been determined. The results showed that the contamination of waste water all exceeded the quality standard except at pH value. The ALT content of wastewater in RPH 2790 x 104 and contains E. Coli and Salmonella microbes. The high content of BOD, COD, TTS, Ammonia and microbial contamination is thought to be due to the absence of wastewater treatment installation (IPAL) at RPH in accordance with the standard. Proper handling of ammonia waste can reduce the amount of carbon in the atmosphere.

Effect on Electroless Nickel Coating on Magnesium Alloy by Nickel Electroless Plating Parameters

2011 ◽  
Vol 295-297 ◽  
pp. 1522-1525
Author(s):  
Xiao Min Wang ◽  
Jun Duo
Keyword(s):  
Magnesium Alloy ◽  
Process Parameters ◽  
Ph Value ◽  
Nickel Coating ◽  
Electroless Nickel ◽  
Molar Ratio ◽  
Electroless Nickel Plating ◽  
Nickel Plating ◽  
Optimum Conditions ◽  
Bath Stability

Electroless nickel plating on magnesium alloy was studied when NiSO4as the main salt in the solution. The influence of the composition of the solution and process parameters on the coating appearance, the plating rate and bath stability was studied too. As a result, the optimum conditions of electroless nickel are: The main salt and reducing agent molar ratio between 0.3 and 0.45, mixed complexion agents was used, temperature 90°C, pH value 6.5.

Process Study on Green Treatment of Waste Anolyte

2014 ◽  
Vol 1015 ◽  
pp. 350-354
Author(s):  
Li Na Chen ◽  
Wan Yi Liu ◽  
Qi Lin Hu
Keyword(s):  
Ph Value ◽  
Removal Rate ◽  
Chemical Precipitation ◽  
Environmental Benefits ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Dihydrogen Phosphate ◽  
Waste Solution ◽  
Hydrogen Carbonate ◽  
Ammonium Hydrogen

Contraposing the waste anolyte of industry, the paper proposed a new chemical precipitation method to recover Mn (II) ions and Mg (II) ions from the waste solution using ammonium hydrogen carbonate and ammonium dihydrogen phosphate as precipitants, respectively. The technological conditions of dealing procedure such as the molar ratio of reactants, pH value, reaction temperature and time, aging time were investigated. The results shown that the removal rate of Mn (II) ions and Mg (II) ions reached to 96 % and 98 %, and the yields of MnCO3 and NH4MgPO4·6H2O reached to 91 % and 94 %, respectively. The residual solution was recycled to realize the treatment greenly, which could meet the needs of production and increase environmental benefits.

Characterization of Nano-Biphasic Calcium Phosphates Synthesized under Microwave Curing

2008 ◽  
Vol 3 ◽  
pp. 67-87 ◽  
Author(s):  
Wafa I. Abdel-Fattah ◽  
Fikry M. Reicha ◽  
Tarek A. Elkhooly
Keyword(s):  
Ph Value ◽  
Calcium Phosphates ◽  
Chemical Precipitation ◽  
Calcium Deficiency ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microwave Curing ◽  
Tcp Phase ◽  
Diffraction Patterns

Two biphasic BCP ceramic samples were synthesized by chemical precipitation and microwave curing of calcium deficient hydroxyapatite CDHA under the same pH value and temperature but varied in their initial Ca/P molar ratio. Precipitates were characterization after thermogravimetric analysis, fourier transform infrared spectroscopy, X-ray diffraction, atomic absorption spectroscopy and TEM. Hydroxyapatite (HA) contents were measured for the two biphasic calcium phosphate (BCP) ceramics by sintering the calcium-deficient apatites (CDHA). The results reveal two condensation mechanisms of HPO42- affecting the Ca/P molar ratio after calcination. The X-ray diffraction patterns of BCP powders show the in situ formation of -TCP in the BCP powder. The amount of -TCP phase increases as the initial Ca/P molar ratio decreases due to more calcium deficiency in CDHA structure. The influence of HPO42- incorporation on increasing -TCP phase content after calcination is evaluated. TEM micrographs proved the effect of microwave curing during the preparation process on reducing of particle size to nanoscale range and the destruction of CDHA to finer HA and -TCP particles upon calcination.

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