Surface-tension-induced interfacial convection and its effect on rates of mass transfer

Surface-tension-induced interfacial convection (Marangoni phenomena) can appear as a result of mass and heat transfer, compression and dilatation of surface films or their non-Newtonian behaviour and owing to presence in the interface of electrostatic charges. In process engineering problems the mass transfer effect is usually predominant and, depending on the geometry of the system, leads to surface renewal or changes in interfacial area. The surface renewal phenomena can appear as instabilities or disturbances and their effect on mass transfer is presented for transfer to and from drops as well as across flat interfaces in stirred and laminar flow contactors. Mass transfer coefficients and drag coefficients of drops are compared under conditions of undisturbed (diffusional) transfer, cellular convection and interfacial turbulence for stable and unstable direction of transfer. The importance of gravitational instability is indicated.     

Thin plate elements with relaxed Kirchhoff constraints

An analysis of thin plates by C⁰ elements is presented. The fundamental part of it is the formulation of a set of constraints that relate the rotational degrees of freedom to the translational degrees of freedom and which are weaker than the usual Kirchhoff constraints. A penalty term associated with these constraints is then introduced instead of the usual expression for the shear strain energy. It is shown that the approach is effective for both quadrilateral and triangular elements.     

Review of Psychology: The unity of human behavior.

Reviews the book "Psychology: The unity of human behavior," by Timothy J. Gannon (see record 1954-06735-000). This volume is an introductory textbook of psychology for college students. In addition to a somewhat different organization of the material and a different emphasis accorded to various topics Gannon's book introduces certain theoretical considerations which are not ordinarily found in most textbooks. The book is divided into four parts: The first part, the shortest, is a general introduction. The second, entitled "Reception," deals with sensation and perception. The author, in discussing perception, particularly stresses the neural correlates of perception and the localization of functions in the brain. The third, "Response," contains the discussion of reflexes, drives, and emotions. The fourth and last part, "Integration," is the longest, constituting almost half of the book. The principal concern of the author is to present all experiences, and all behavior, as integrated manifestations of a single living person. The entire book is characterized by an effort to present to the student not merely a survey of psychological problems and known facts about man but to provide him at the same time with a concept of man's nature which would serve as a key to the understanding of man as such. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cyclization in chain-crosslinking copolymerization

Summary Styrene and ethylene dimethacrylate were polymerized in benzene solutions to high conversions. Gels were prepared from critical concentrations of the divinylidene monomer and the fractions of the divinylidene units engaged in intermolecular crosslinks were estimated. The fractions were found to be very small, viz. 5, 10 and 18 % at the total monomer concentrations 1, 2 and 3 mol/dm³, respectively. Behaviour of pregel polymers suggests that cyclization of primary chains and multiple crosslinking are responsible for the low efficiency of the crosslinking agent.Presented at the 7th IUPAC Discussion Conference Polymer Networks, Karlovy Vary, CSSR, September 15–19, 1980     

Histochemistry of some acid hydrolases in striated muscles of the rat

Endoscopic sphincterotomy of the ampulla of Vater was performed in seven patients suffering from gallstones in the common bile duct and/or bile flow stasis. After this procedure, spontaneous delivery of gallstones occurred in two cases and a gallstone was extracted by our basket-tipped catheter in two cases. The electromyogram of the sphincter of Oddi after endoscopic sphincterotomy showed the similar patterns and rhythms to those before this procedure. Thus, the function (bile flow mechanism) of the sphincter was not destroyed by this procedure. Morphologic and physiologic data, therefore, lead to the conclusion that endoscopic sphincterotomy is a safe and useful procedure.     

Synergy and resistance to synergy between beta-lactam antibiotics and glycopeptides against glycopeptide-resistant strains of Enterococcus faecium

A synergistic effect between vancomycin or teicoplanin and different beta-lactam antibiotics was found for two strains of Enterococcus faecium, EFM4 and EFM11, expressing resistance to glycopeptides and belonging to the VANA class. The MICs of penicillin for these two strains were 16 and 128 micrograms/ml, respectively. By using a penicillin-binding protein (PBP) competition assay, it was shown that the affinities of PBPs for different beta-lactam antibiotics and the MICs of these antibiotics obtained in the presence of teicoplanin correlated with the substitution of two high-molecular-weight PBPs for the low-molecular-weight PBP5 as the essential target. Mutants of EFM4 and EFM11 which had lost the synergistic effect between beta-lactams and glycopeptides were selected on teicoplanin plus ceftriaxone at a frequency of 10(-5) and 10(-3), respectively. The mechanism of the loss of synergy was explored. For the mutants derived from EFM4, it was associated with a change in PBPs, while for the mutants derived from EFM11, it was related to some unknown change on the conjugative plasmid responsible for the glycopeptide resistance. These combined observations reflect the relationship which seems to exist between the new D-lactate peptidoglycan precursor, synthesized when the vancomycin resistance is expressed, and the affinity of the different PBPs for this precursor.     

Circulating fluid-bed reactor for coal pyrolysis

A high temperature coal pyrolysis reactor was developed and its operation demonstrated on a scale of 8 t/h. Pyrolysis is performed in a circulating fluidized bed reactor at 850–950°C. The developed process was integrated into smokeless fuel production technology and tested. Experimental data and reactor performance are presented.