Water Molecules in Organic Solvents Involved in the Synergistic Extraction of Europium(III) withβ-Diketones and Lewis Bases

2001 ◽  
Vol 74 (10) ◽  
pp. 1879-1883 ◽  
Author(s):  
Yuko Hasegawa ◽  
Kiyotaka Nakaya ◽  
Izuru Matsubayashi
1980 ◽  
Vol 45 (8) ◽  
pp. 2300-2307 ◽  
Author(s):  
Miriam Gálová ◽  
Daniela Kladeková

Molar enthalpies of dissolution of aluminium chlorides, bromides, and iodides in acetonitrile and tetrahydrofuran at 295 K have been determined experimentally. results of the measurements carried out in presence of air humidity point to the fact that both solvents preferential solvation of the solute by water molecules takes place. In an inert atmosphere, all the values obtained are negative. molar heat of dissolution has for AlCl3 the lowest negative value: -181 kJ mol-1 in acetonitrile and -107.8 kJ mol-1 in tetrahydrofuran. For AlBr3 and AlI3 exothermicity of dissolution is considerably higher: -817 and -887 kJ mol-1 for acetonitrile, and -489 and -713 kJ mol-1 for tetrahydrofuran. The transfer from water into both organic solvents has an endothermic character for AlCl3 only; for AlBr3 and AlI3, the character of transfer is unambiguously exothermic. The obtained results are interpreted as effects of interaction between the solute and the solvent.


2020 ◽  
pp. 124-135
Author(s):  
I. N. G. Wardana ◽  
N. Willy Satrio

Tofu is main food in Indonesia and its waste generally pollutes the waters. This study aims to change the waste into energy by utilizing the electric charge in the pores of tofu waste to produce hydrogen in water. The tofu pore is negatively charged and the surface surrounding the pore has a positive charge. The positive and negative electric charges stretch water molecules that have a partial charge. With the addition of a 12V electrical energy during electrolysis, water breaks down into hydrogen. The test was conducted on pre-treated tofu waste suspension using oxalic acid. The hydrogen concentration was measured by a MQ-8 hydrogen sensor. The result shows that the addition of turmeric together with sodium bicarbonate to tofu waste in water, hydrogen production increased more than four times. This is due to the fact that magnetic field generated by delocalized electron in aromatic ring in turmeric energizes all electrons in the pores of tofu waste, in the sodium bicarbonate, and in water that boosts hydrogen production. At the same time the stronger partial charge in natrium bicarbonate shields the hydrogen proton from strong attraction of tofu pores. These two combined effect are very powerful for larger hydrogen production in water by tofu waste.


2017 ◽  
Vol 5 (4) ◽  
pp. 26-32 ◽  
Author(s):  
Azaria Robiana ◽  
M. Yashin Nahar ◽  
Hamidah Harahap

Glycerin residue is waste oleochemical industry that still contain glycerin. To produce quality and maximum quantity of glycerin, then research the effect of pH acidification using phosphoric acid. Glycerin analysis includes the analysis of pH, Fatty Acid and Ester (FAE), and analysis of the levels of glycerin. The maximum yield obtained at pH acidification 2 is grading 91,60% glycerin and Fatty Acid and Ester (FAE) 3,63 meq/100 g. Glycerin obtained is used as a plasticizer in the manufacture of bioplastics. Manufacture of bioplastics using the method of pouring a solution with varying concentrations of starch banana weevil (5% w/v and 7% w/v), variations of the addition of glycerin (1 ml, 3 ml, 5 ml and 7 ml), and a variety of gelatinization temperature (60°C, 70°C, and 80°C). Analysis of bioplastics include FTIR testing, tensile strength that is supported by SEM analysis. The results obtained in the analysis of FTIR does not form a new cluster on bioplastics starch banana weevil, but only a shift in the recharge area only, it is due to the addition of O-H groups originating from water molecules that enter the polysaccharide through a mechanism gelatinitation that generates interaction hydrogen bonding strengthened. The maximum tensile strength of bioplastics produced at a concentration of starch 7% w/v, 1 ml glycerine and gelatinization temperature of 80°C is 3,430 MPa. While the tensile strength bioplastic decreased with increasing glycerin which can be shown from the results of SEM where there is a crack, indentations and lumps of starch insoluble.


1960 ◽  
Vol XXXV (I) ◽  
pp. 34-48 ◽  
Author(s):  
Gerd Ittrich

ABSTRACT A series of organic solvents and phenol derivatives have been examined for the extraction of the pink Kober-colour complex. Optimal results could be achieved for fluorimetry by a solution of 2 % (w/v) p-nitrophenol and 1 % (v/v) ethanol in acetylenetetrabromide, when the green mercury line (546 mμ was used as primary light. The sensitivity, stability and specificity have been improved, compared with the previously described reaction. By changing the sequence of purification steps and by reducing the volume of the urine sample (5 ml) the method for the determination of total oestrogens has been simplified. Approximately 10 determinations can be done within 3–4 hours by one person. Recovery experiments and comparative determinations with a previously described method have been carried out. The excretion of total oestrogens in a complete menstrual cycle is determined with the described method.


2015 ◽  
Vol 60 (3) ◽  
pp. 263-267
Author(s):  
L.A. Bulavin ◽  
◽  
S.V. Khrapatyi ◽  
V.M. Makhlaichuk ◽  

Sign in / Sign up

Export Citation Format

Share Document