effective methodologies for efficient preparation of semicarbazones from aldehydes or ketones via milling and the subsequent regeneration of the parent carbonyls by gaseous nitrogen dioxide are described under solid-solid and gas-solid reaction conditions, respectively. these methods are fast, simple and environmentally benign which do not require the use of any auxiliaries such as catalysts or...

In quantum theory Hamilton operators with spininteractions have a long history [1 – 5]. Triple spin interaction have been studied by several authors [6 – 19]. Iglói [6] investigated an Ising model with three-spin interaction by finite-size scaling and applying free boundary conditions. Vanderzande and Iglói [7] studied the critical behaviour and logarithmic corrections of a quantum model with t...

Free care does not always lead to improved outcomes. Attendance at free clinic appointments is unpredictable. Understanding barriers to care could identify innovative interventions. The purpose of this study was to examine patient characteristics, biophysical outcomes, and health care utilization in uninsured persons with diabetes at a free clinic. A sample of 3139 patients with at least one ch...

a facile and efficient method for the preparation of 1,1-diacetates of aldehydes is improved. the acidified kaolin with sulfuric acid (2 % w/w) catalyzed 1,1-diacetates formation from aldehydes in solvent-free conditions. both aromatic and aliphatic aldehydes gave high yields (85-95 %) of the corresponding 1, 1-diacetates. advantages of this method are the use of inexpensive and selective catal...

in this paper we introduce the construction of free profinite products of profinite groups withcommuting subgroups. we study a particular case: the proper free profinite products of profinite groups with commuting subgroups. we prove some conditions for a free profinite product of profinite groups with commuting subgroups to be proper. we derive some consequences. we also compute profinite comp...

a simple, clean, and environmentally benign three-component process for the synthesis of 2-amino-4hchromenes using [mim]cl, as an efficient catalyst under solvent-free conditions are described. a wide range of aromatic aldehydes easily undergoes condensations with 1-naphthol and malononitrile under solvent-free conditions to afford the desired products of good purity in excellent yields. taking...

New theorems of the alternative for polynomial constraints (based on the Positivstellensatz from real algebraic geometry) and for linear constraints (generalizing the transposition theorems of Motzkin and Tucker) are proved. Based on these, two Karush-John optimality conditions – holding without any constraint qualification – are proved for singleor multi-objective constrained optimization prob...