Tests of composite concrete beams with prestressed planks

This paper deals with tests on composite concrete beams with prestressed concrete planks. It describes the separate influences of differential shrinkage and creep as well as stress redistribution due to a great strain difference at the adjoining faces between the prestressed plank and added concrete. Existing formulas relating to differential shrinkage and creep are based on the actual strains to be expected, but in order for the designer to have this information, extensive tests are required. This paper contains qualitative data in this regard and describes means by which information can be satisfactorily obtained, including the effect of stress redistribution.     

The theory of transient photoconductive processes in II–VI compounds with three deep trapping levels

The transient photoconductive rise and decay processes were studied quantitatively in a typical II–VI compound by solving the rate equations on a digital computer. The calculations were based on a model with three deep trapping levels, as proposed by Rose and by Bube. A study was made of the effect of changing the concentration, position, and capture asymmetry fo these levels. We have also considered the way in which the defect centers change their role from trapping to recombination (or vice versa) as a result of free carrier concentration changes. Our work confirms previous explanations of the relation between sensitizing level properties and the steady-state superlinear behavior exhibited by II–VI photoconductors. On the other hand, a different approach appears to be necessary to account for transient phenomena. We do not believe that the position or asymmetry of the trapping levels is crucial in determining photoconductive sensitivity and response times. Instead, we find that these material properties can be predicted from a knowledge of the equilibrium and the steady-state charge concentrations. In addition, we show that the dynamic changes in the function of the deep levels from trapping to recombination, or vice versa, are the consequence—rather than the cause—of the specific way in which the photoconductive rise and decay processes occur.     

Attitude change through modification of attitude structure.

183 experimental Ss were tested regarding their attitudes toward allowing Negroes to move into white neighborhoods, toward 25 values in terms of expected satisfaction from each, and toward the 25 values in terms of "allowing Negroes to move into white neighborhoods" would lead to or block attainment of the values both before and after a change procedure designed to increase the S's awareness that nonsegregation would lead to the attainment of four important values. The experimental procedure changed perceptions and attitudes toward Negro housing segregation in S's with moderate initial attitude on the issue. Little attitude change was produced in extremely prejudiced and extremely nonprejudiced S's (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Proceedings of the fifty-fourth Annual Meeting of the Southern Society for Philosophy and Psychology.

Approximately 200 attended the meeting held on April 19-21, 1962 in Memphis, Tennessee. "The program included 19 papers and 2 symposia in philosophy, 34 papers and 3 symposia in psychology, and 2 joint sessions." The program of papers and their authors is listed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An Application of Transdermal Antiviral Delivery Systems to the Establishment of a Novel Animal Model Approach in the Efficacy Evaluation for Dermatological Formulations

This report described the establishment and the examination of a novel hairless mouse model in the efficacy evaluation for topical antiviral dosage forms with a focus on the relationship between the in vitro dermal flux of the antiviral agent and the in vivo antiviral efficacy. A unique dose/flux-efficacy relationship in topical antiviral treatment was obtained by applying a series of transdermal acyclovir delivery systems (TADS) for the treatment of cutaneous herpes simplex virus type 1 infected hairless mouse in our earlier study. By konwing the pharmacokinetic parameters of acyclovir in hairless mouse and the flux (J) of a suitable TADS, the skin target site concentration (C*) could be calculated for that patch. With the corresponding C* value, the in vivo permeability coefficient (P_{d,in vivo}) of that patch could be calculated from P_{d,in vivo} = J/C*. The difference between this in vivo permeability coefficient and the in vitro permeability coefficient (P_{d,in vivo}. obtained from in vitro diffusion experiment) was considered due to the blood flow effect in the in vivo condition. This P_{d,in vivo} can be further applied to calculate the C* value of any acyclovir topical formulation with flux, J', from C'*=J'/P_{d,in vivo}, where the C'* represents the calculated skin target site concentration for any acyclovir topical formulation. After knowing different C* values of different dermatological formulations of acyclovir, the efficacy of each formulation can be estimated from the dose/flux-efficacy relationship. Two formulations with different fluxes were examined under this study. The results showed very good correlation between the in vitro acyclovir flux and the in vivo antiviral efficacy and the applicability of this model approach was validated.     

Near-Term Travel Speed Prediction Utilizing Hilbert–Huang Transform

Abstract:  Accurate short-term prediction of travel speed as a proxy for time is central to many Intelligent Transportation Systems, especially for Advanced Traveler Information Systems and Advanced Traffic Management Systems. In this study, we propose an innovative methodology for such prediction. Because of the inherently direct derivation of travel time from speed data, the study was limited to the use of speed only as a single predictor. The proposed method is a hybrid one that combines the use of the empirical mode decomposition (EMD) and a multilayer feedforward neural network with backpropagation. The EMD is the key part of the Hilbert–Huang transform, which is a newly developed method at NASA for the analysis of nonstationary, nonlinear time series. The rationale for using the EMD is that because of the highly nonlinear and nonstationary nature of link speed series, by decomposing the time series into its basic components, more accurate forecasts would be obtained. We demonstrated the effectiveness of the proposed method by applying it to real-life loop detector data obtained from I-66 in Fairfax, Virginia. The prediction performance of the proposed method was found to be superior to previous forecasting techniques. Rigorous testing of the distribution of prediction errors revealed that the model produced unbiased predictions of speeds. The superiority of the proposed model was also verified during peak periods, midday, and night. In general, the method was accurate, computationally efficient, easy to implement in a field environment, and applicable to forecasting other traffic parameters.     

The traditional editorial statement.

Earl Hunt writes a brief editorial at the outset of his term, saying what he hopes to accomplish. He believes the Journal of Experimental Psychology has evolved to fulfill a very important role in the scientific literature. Inevitably, and properly, the psychological sciences have specialized. This means that more than ever, there is a need for a publication outlet that spans more than one of the subfields of experimental psychology. He also believes authors who wish to report negative results should provide power statistics. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

New process concepts for CO2 post-combustion capture process integrated with co-production of hydrogen

This work describes a study in advanced post-combustion based on CO₂-capture technologies to be integrated within the Hypogyny concept (electricity generation with co-hydrogen production). Two different Hypogen concepts based on integrating IGCC (Integrated Gasification Combined Cycle) and post-combusting CO₂ capture are proposed and investigated: the first concept, hydrogen production based on syngas shifting with high-pressure CO₂ capture, while the second concept, hydrogen is produced based on membrane separation from syngas.In the first concept, combining a high-pressure and an ambient-pressure CO₂ absorber in one flow sheet and one regeneration column is found to be feasible. However, the advantage of the high CO₂ partial pressure in the high-pressure absorber is more obvious if an advanced solvent like 2-amino-2-methyl-1-propanol (AMP) is used instead of monoethanolamine (MEA) solvent kind.The second concept of using polymeric membrane for hydrogen production is considered feasible and comparing to the first concept, cost competitive with around 10% higher overall capital cost. However, the membrane unit does not achieve high hydrogen purity because the investigated concept is limited to a maximum purity of around 95%. Therefore, hydrogen selective membrane technically requires an extra hydrogen purification step e.g. further membrane separations or a pressure swing adsorption (PSA).In addition to these two concepts, the influence of flue gas circulation, gasifier selection and an advanced solvent based on the sterically hindered amine AMP was investigated. Flue gas circulation (higher CO₂-concentrations) has no influence on the regeneration energy requirements when a high binding-energy solvent like MEA is used. The main benefit is that flue gas circulation results with more compact absorption equipment. For AMP type of solvents flue gas circulation results in a substantial reduction in regeneration energy and the overall cost of CO₂ avoided. 37% reduction in the avoided cost with a flue gas recycle ratio of 45% is achieved using AMP as a solvent comparing to 10% using MEA solvent.These Hypogen strategies appear to be feasible and the overall cost of these concepts is comparable with the conventional post-combustion capture process. However, there is a significant potential for further improvement by applying more developed solvents, processes, and membranes.