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)     

Rigidity in the retarded: A further test of the Lewin-Kounin formulation.

Groups of younger and older familial retardates from 2 institutions and a group of normals were compared on 3 of Kounin's measures of rigidity. The general findings were inconsistent with the Lewin-Kounin rigidity formulation and the results reported by Kounin. The differences obtained between the groups investigated here are discussed in terms of a number of cognitive and motivational factors which have been advanced to explain differences in performance between normals and retardates of the same MA. (30 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Improved strain-anneal crystal growth technique

A new method of growing iron single crystals* of predetermined orientation is described. *U.S. Patent No. 3694269. This technique differs from the conventional strain-anneal method in that pulse heating is used to suppress random nucleation of undesired grains ahead of the growth interface, rather than a traveling “sharp” temperature gradient which is often difficult to attain. The procedures used to grow large α-iron single crystals with the new technique are fully described. A significant advantage of this method is that large oriented single crystals, 25 cm (10 in.) or greater in length, can be grown from rods or strip in a few hours, with a much higher probability of success than can be obtained with the conventional technique, which typically requires several days to obtain crystals of this size.     

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.     

Antigenic implications of human immunodeficiency virus type 1 envelope quaternary structure: oligomer-specific and -sensitive monoclonal antibodies

A majority of monoclonal antibodies (mAbs) raised against soluble oligomeric human immunodeficiency virus type 1 isolate IIIB (HIV-1IIIB) envelope (env) glycoprotein reacted with conformational epitopes within the gp120 or gp41 subunits. Of 35 mAbs directed against gp41, 21 preferentially reacted with oligomeric env. A subset of these mAbs reacted only with env oligomers (oligomer-specific mAbs). In contrast, only 1 of 27 mAbs directed against the gp120 subunit reacted more strongly with env oligomers than with monomers, and none were oligomer-specific. However, 50% of anti-gp120 mAbs preferentially recognized monomeric env, suggesting that some epitopes in gp120 are partially masked or altered by intersubunit contacts in the native env oligomer. Two mAbs to oligomer-dependent epitopes in gp41 neutralized HIV-1IIIB and HIV-1SF2, and binding of these mAbs to env was blocked by preincubation with HIV-1-positive human serum. Thus, immunization with soluble, oligomeric env elicits antibodies to conserved, conformational epitopes including a newly defined class of neutralizing antibodies that bind to oligomer-specific epitopes in gp41, and may also minimize the production of antibodies that preferentially react with monomeric env protein.     

Droplet size and viscosity of tackifier emulsions formed via phase inversion

Tackifier dispersions used in pressure‐sensitive adhesives are made by phase inverting an aqueous rosin ester emulsion. The recipe also includes rosin acid and potassium hydroxide which react to form a surfactant. The amount of surfactant available plays a key role in determining dispersion properties. As the surfactant concentration increases, the point of phase inversion is delayed to larger dispersed phase concentrations. This also results in excess dispersant in the liquid phase and a narrower particle size distribution, even though the droplet size remains relatively unchanged.