A postdoctoral program in behavior modification: Theory and practice.

Describes a postdoctoral program in behavior modification which suggests that behavior therapy as an approach to clinical problems has more in common with experimental psychology than with other areas. A corollary of this position is a view of behavior modification as an applied general psychology, not limited by narrow views of conditioning therapy or by radical behavioristic constraints. A principal theme is that an academic setting provides the best opportunity for learning and thinking critically about this field. Specific features of the program as it now functions are detailed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The influence of three reinforcement modifications on perseveration in psychotic children.

A study of an operant conditioning approach to the treatment of schizophrenic and autistic children showed agreement with an earlier comment by Leff. The authors conclude further that procedures derived from the basic principles of operant technology may facilitate the realization of effective treatment aids in the area of childhood psychosis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The use of parallel logic in teaching engineering and science

The use of the analog computer in teaching engineering and science has become increasingly widespread.

The reason for this vogue is that the analog computer can easily solve differential equations, linear and non-linear, which characterize so many physical systems.

However when the mathematical model requires decision making logic switching, timing, memory or individual mode control of analog components, the need to add parallel logic to the analog computer becomes self-evident.

This paper intends to show how it is possible to extend the capabilities of the analog computer by the addition of parallel logic.     

Comparison of ultrasonic distillation to sparging of liquid mixtures

The application of intense ultrasound to a liquid-gas interface results in the formation of an ultrasonic fountain and generates both mist and vapor from the liquid. Here, the composition of the vapor and aerosol above an ultrasonic fountain is determined as a function of irradiation time and compared with the results of sparging for five different solutions. The experimental apparatus for determining the efficiency of separation consists of a glass vessel containing a piezoelectric transducer driven at either 1.65 or 2.40 MHz. Dry nitrogen is passed over the ultrasonic fountain to remove the vapor and aerosol. The composition of the liquid solutions are recorded as a function of irradiation time using gas chromatography, refractive index measurement, nuclear magnetic resonance, or spectrophotometry. Data are presented for ethanol-water and ethyl acetate-ethanol solutions, cobalt chloride in water, colloidal silica, and colloidal gold. The experiments show that ultrasonic distillation produces separations that are somewhat less complete than what is obtained using sparging.     

Hierarchical Matrices in Computations of Electron Dynamics

We discuss the approximation of the meanfield terms appearing in computations of the multi-configuration time-dependent Hartree–Fock method for the solution of the time-dependent multi-particle (electronic) Schrödinger equation by hierarchical matrices. We give theoretical error bounds for the cross approximation defined by low rank approximations of admissible matrix sub-blocks, and illustrate the gain in performance by numerical experiments.     

Modeling Mass Removal during In Situ Air Sparging

A model was developed to simulate mass removal during in situ air sparging. The model captures the physical characteristics of the air plume and employs conventional methods to simulate mass transfer. A parametric study was conducted using the model to assess how chemical properties, the operational method, and media affect mass removal during in situ air sparging. Mass removal is particularly sensitive to Henry's law constant, and the aqueous diffusion coefficient when Henry's law constant is high. Simulations of pulsed and continuous air injection show that pulsed injection can yield greater mass removal than continuous air injection for certain pulse cycles. Mass removal is generally greater at higher injection rates, but the increase in mass removal diminishes as the injection rate increases. Parametric analysis also showed that mass is removed faster when air channels are narrower or more tortuous (i.e., in coarser or more well-graded formations).     

The relationship between brain injury criteria and brain strain across different types of head impacts can be different

Multiple brain injury criteria (BIC) are developed to quickly quantify brain injury risks after head impacts. These BIC originated from different head impact types (e.g. sports and car crashes) are widely used in risk evaluation. However, the accuracy of using the BIC on brain injury risk estimation across head impact types has not been evaluated. Physiologically, brain strain is often considered the key parameter of brain injury. To evaluate the BIC''s risk estimation accuracy across five datasets comprising different head impact types, linear regression was used to model 95% maximum principal strain, 95% maximum principal strain at the corpus callosum and cumulative strain damage (15%) on 18 BIC. The results show significantly different relationships between BIC and brain strain across datasets, indicating the same BIC value may suggest different brain strain across head impact types. The accuracy of brain strain regression is generally decreasing if the BIC regression models are fitted on a dataset with a different type of head impact rather than on the dataset with the same type. Given this finding, this study raises concerns for applying BIC to estimate the brain injury risks for head impacts different from the head impacts on which the BIC was developed.