Priming and aging: an electrophysiological investigation of N400 and recall

Twenty young (20.5 years) and 20 middle-aged academics (57.2 years) performed a priming-recall task which was presented in three blocks. In each block, participants read 40 word pairs after which a recall task had to be carried out. Half of the word pairs were highly associated while the others were low associated. Targets showed the N400 of the middle-aged group to be both delayed and smaller in amplitude for low-associated items. N400 of primes, however, showed no age-related latency difference but was smaller for the middle-aged group due to a positive shift. It is argued that this shift possibly indicates age differences in semantic activation or buildup of context. A reanalysis showed individual differences in word pair processing to depend on recall performance. In general, high recallers were found to show a much larger differentiation between low- and high-associated targets. This resulted from a much larger N400 component elicited by low-associated targets and a more positive ERP in the N400-region for the high-associated targets. It is suggested that the middle-aged subjects activated the expected target word to a level at least equivalent to the younger subjects, but that the activated network itself was larger/less selective particularly in subjects showing a low recall.     

IS QUALITY ENGINEERING AN OXYMORON?

It is my purpose in this editorial to offer some highly personal and likely controversial views on the state of statistics and the quality profession. These views are based on my personal experiences and prejudices-especially those of my 10 years as an independent statistical consultant. I wish to particularly absolve my current employer, Merck and Company, and my colleagues there of any guilt by association. The opinions rendered here are entirely my own and in no way represent Merck's practices or policies, Mea culpa.     

Scale-up von Destillationskolonnen

Scale-up of Distillation Columns. In spite of remarkable advances in the development of computer programs for calculations on distillation columns, it is frequently still impossible to design them without experimental testing. Economic constraints demand use of miniaturised test plant, thus enhancing the importance of laboratory measurements. A system is presented for scale-up of separation which required information from laboratory experiments, includes data from reference columns, and takes account of models of fluid dynamics and mass transfer. The special feature of this approach lies in the free choise of internals, both in the laboratory and in the designed column.     

Sliding friction behaviour of polymer-polymer material combinations

The intermolecular bonding energies of polymeric materials can be employed in the evaluation of sliding under conditions determined predominantly by adhesion. The effect at the interface of these energies can be evaluated by reference to the surface energy and to its polar and dispersion-related components. Wetting angle measurements were used to determine the work of adhesion for a group of polymer-polymer material combinations. An exponential relationship exists between the work of adhesion and the coefficients of friction of these combinations, these coefficients of friction being determined primarily by adhesion.     

Heat transfer during fluidized-bed coating

A fully implicit numerical method for linear parabolic free boundary problems with coupled and integral boundary conditions is described. The partial differential equation and the boundary conditions are time discretized with the method of lines. An auxiliary function is introduced to remove the coupled and integral boundary conditions from the resulting free boundary problem for ordinary differential equations. Once separated boundary conditions are obtained, invariant imbedding is used to solve the free boundary problem numerically. The method is illustrated by solving the heat transfer equations for the fluidized-bed coating of a thin-walled cylinder.     

High purity gadolinium by electrorefining in fused salts—II. Electrocrystallization in the LiFBaF2GdF3 mixture

The interaction of alkali metal and alkaline earth metal fluorides with gadolinium trifluoride is evaluated in terms of the Tobolsky parameter. BaF₂ is found to exert a pronounced destabilization effect on the tysonite structure of GdF₃. In comparison with the 75LiF25 mol% GdF₃ electrolyte, the 75LiF10BaF₂15 mol% GdF₃ mixture influenced the charge-transfer process in such a way as to reduce the deposition voltage by 0.1 V and to change the deposit morphology from uniaxial (001)-needles to block formations.The content of the interstitial elements H, N and O in the deposited gadolinium was 54, 25 and 79 ppm respectively. The highest concentrations of the other impurities were Li(22), Fe(16), Ba(35), La(3), Ce(3.3), Pr(2.7), Nd(8.9), Tb(20). Dy(2.4) and Th(4 ppm).     

Einfluß von Kobalt auf die martensitischen Umwandlungen in austenitischen Stählen mit rd. 18% Cr und 10% Ni

Röntgenographische, magnetische, metallographische und dilatometrische Untersuchung der martensitischen Umwandlung bei +20 und –196 °C an einer Legierungsreihe, bei der – ausgehend von einem kohlenstoffarmen Stahl mit rd. 18% Cr und 8% Ni– stufenweise je 7% Fe + 2% Cr + 1% Ni durch 10% Co ersetzt wurden, nach Abschrecken und zusätzlicher plastischerVerformung. Ermittlung des Einflusses von Kobalt auf mechanische und magnetische Eigenschaften, Dichte und Gitterkonstante des Austenits. Versuch der lückenlosen Überführung der hexagonalen ?-Phase austenitischer Chrom-Nickel-Stähle in die Tieftemperaturmodifikation des Kobalts durch zusätzliche Versuche an Legierungen, bei denen – ausgehend von rd. 40% Co, 10% Cr und 6% Ni – der Nickelgehalt bis auf 0% abgesenkt wurde.