Local oscillator chain for 1.55 to 1.75THz with 100-/spl mu/W peak power

We report on the design and performance of a fix-tuned /spl times/2/spl times/3/spl times/3 frequency multiplier chain that covers 1.55-1.75THz. The chain is nominally pumped with 100mW at W-band. At 120K the measured output power is larger than 4/spl mu/W across the band with a peak power of 100/spl mu/W at 1.665THz. A similar chain operated at room temperature produced a peak power of 21/spl mu/W. These power levels now make it possible to deploy multipixel heterodyne imaging arrays in this frequency range.     

The location of noisy visual stimuli.

Examined the results of experiments where Ss were required to detect the misalignment of 2 abutting dot clusters on a monitor screen. Thresholds varied with the square root of dot density and did not appear to be affected by changing the sampling strategy used to generate the random dot clusters. Comparison of the Ss' performance with that expected of 3 information processing strategies suggested that Ss accomplished the task by locating the edges of the dot clusters rather than by extracting measures of global scope or of central position. The efficiency with which edge information was extracted was approximately 50% for low-density stimuli and declined exponentially with increasing dot density. (French abstract) (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The calibration of slow neutron polarised beam instruments

A new procedure for calibrating the efficiencies of the polarisation sensitive components in slow neutron polarised beam instruments is described. The measurement of one “flipping ratio” and two “shim ratios” allows the effective polarisation, the spin flipping efficiency, and a depolarising shim efficiency to be determined unambiguously. Results of its application to the calibration of a neutron time-of-flight polarised beam reflectometer are presented.     

Modelling and adaptive control of fed-batch penicillin fermentation

This paper describes a study to investigate the application of state estimation and parameter adaptive control in fed-batch fermentation for penicillin production. A model of the penicillin fermentation process is outlined and shown to be capable of matching industrial data. The penicillin mould biomass is controlled to a reference trajectory by applying self-tuning control to an estimate of biomass, obtained from measurements of carbon dioxide production rate and fermenter volume and by using the fermentation model with an extended Kalman filter. The manipulated variable, sugar feed to the fermenter, is calculated by an adaptive algorithm. Simulation results compare the performance of self-tuning control with that obtained using digital Proportional plus Integral control.     

Multiple measures of hand-use lateralization in the ring-tailed lemur (Lemur catta).

Evaluated a free-ranging matriline of 13 ring-tailed lemurs (Lemur catta) from videotaped records for lateralized hand use with 2 tasks and 4 measures: food reaching, feeding posture, duration of food holding, and manipulation of food between mouth and hand while eating. Binomial z scores determined 7 lemurs to be left preferent in reaching, 3 right, and 3 ambipreferent. Ideographic analyses suggested possible sex-linked and early experience twin effects. When compared to right and ambipreferent lemurs, left reach preferent lemurs used the left hand more but bimanuals grasped less in food holding and also engaged in less hand-mouth food manipulation. The tendency to manipulate food was not correlated with bimanual holding but was inversely related to left hand holding and directly related to right hand holding. These patterns are discussed as possible precursors of human bimanual manipulation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Maximizing versus satisficing: Happiness is a matter of choice.

Can people feel worse off as the options they face increase? The present studies suggest that some people--maximizers--can. Study 1 reported a Maximization Scale, which measures individual differences in desire to maximize. Seven samples revealed negative correlations between maximization and happiness, optimism, self-esteem, and life satisfaction, and positive correlations between maximization and depression, perfectionism, and regret. Study 2 found maximizers less satisfied than nonmaximizers (satisficers) with consumer decisions, and more likely to engage in social comparison. Study 3 found maximizers more adversely affected by upward social comparison. Study 4 found maximizers more sensitive to regret and less satisfied in an ultimatum bargaining game. The interaction between maximizing and choice is discussed in terms of regret, adaptation, and self-blame. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An extended soluble gas exchange model for estimating pulmonaryperfusion. I. Derivation and implementation

A dynamic model for respiratory exchange of blood soluble gas is described. This model includes a general treatment of tidal breathing, an inhomogeneous lung comprising multiple distensible compartments, and nonlinearities due to multiple-gas effects. The motivation for this new model is the continuing interest in estimating pulmonary perfusion from measurements of respiratory soluble gas exchange. Numerical simulation can be employed to investigate the errors that result from simplifications made in the derivations of simpler models used for this purpose. Examples of such simplifications are the assumptions that ventilation is constant and unidirectional, and that multiple soluble gases can be independently modeled. These results can delimit the boundaries within which perfusion estimates can be considered reliable. An example demonstrating the model and its numerical solution is presented.