the aim of this study is to evaluate the influence of ph on the synthesis of nanocrystallines cobalt ferrite by combination of sol- gel auto combustion and ultrasonic irradiation methods. two different fuels, urea and thiourea, along with metal nitrates (oxidant) were used to prepare cofe2o4 powders. the morphology of the resulting powders was investigated. the powders were characterized by x-r...

A reinvestigation of the nitrogen-14 NQR in thiourea has permitted to record, apparently for the first time, the resonances above 169 K. The first order and second order of the transitions at 169 K and 202 K, respectively, appear clearly from the temperature dependence of the resonance frequencies; the modulated structure, incommensurate or commensurate, is also seen on the N NQR spectrum. This...

some n¬-acyl-n'-aryl thiourea derivatives 4(a-f) have been prepared by the reaction of acyl halides ammonium thiocyanate and aryl amines. the structures of synthesized compounds have been characterized by ir, 1hnmr spectral studies. the synthesized compounds 5(a-f) have been screened for antibacterial activity. the effect of the structure of the investigated compounds on the antibacterial activ...

für Naturforschung in cooperation with the Max Planck Society for the Advancement of Science under a Creative Commons Attribution 4.0 International License. Dieses Werk wurde im Jahr 2013 vom Verlag Zeitschrift für Naturforschung in Zusammenarbeit mit der Max-Planck-Gesellschaft zur Förderung der Wissenschaften e.V. digitalisiert und unter folgender Lizenz veröffentlicht: Creative Commons Namen...

Thiourea, as an alternative medium, is one of the most promising leaching agents for gold recovery by its commercial benefits and research challenges associated with performance environmental impacts. This review article describes operational conditions use Thiourea vs cyanide, chemistry, limitations, toxicity factors, environment, processes. Although thiourea extraction processes have not been...

The real example of GC-MS identification unknown constituent human hair extract belonging to the exhumed remains is considered. this (molecular weight 238 Da) was unsuccessful using both its standard mass spectrum (electron ionization) in combination with lib­ra­ry search, and GC retention index value (~1540 on semi-standard non-polar polydimethyl siloxane stationary phases 5% phenyl groups). H...

Accidental human exposure to a high level of tetramethyl lead is described. Tetramethyl lead is blended with petrol as an antiknock agent, and it has similar physical properties to tetraethyl lead. The patient had high levels of lead in urine, averaging 4-75 mumol (983 mug) daily for the first four days after exposure and he continued to have raised levels of urinary lead for six months. He had...

Tetramethyl lead (TML) has recently been adopted as an antiknock substance in gasoline. In some industries, tetramethyl lead has been substituted for tetraethyl lead (TEL) mixture or "ethylfluid". This recent development is the result of technical research which has shown that there is a more uniform octane distribution in all light and heavy fractions of gasoline in the combustion cylinders wi...

How chemical structure changes affect the curing reactions and thermal properties of 2,2 -bis(4-cyanatophenyl) propane (cyanate ester) cured rigid-rod epoxy resins has been studied for biphenol and tetramethyl biphenol epoxies. The formation of an oxazolidinone ring is the dominant curing reaction for biphenol epoxy, whereas the formation of a cyanurate ring is the dominant curing reaction for ...

The reactive intermediate generated by the addition of tert-butyl and 1,1,3,3-tetramethyl butyl isocyanide and cyclohexyl isocyanide to dialkyl acetylenedicarboxylate was trapped by 3-hydroxy pyridine to produce highly functionalized 4H-chromenes in fairly good  yields