Probing a model of educational productivity in high school science with national assessment samples.

Tested a psychological theory of educational productivity and explored the usefulness of the National Assessment of Educational Progress data for secondary analysis for policy purposes. The science achievement scores of 3,049 17-yr-old students were regressed on indexes of their socioeconomic status, motivation, quality (of instruction), class (social psychological environment), homework, and home conditions. Findings indicate that all measures of these productivity factors are significant in ordinary multiple regression equations when controlled for one another and race and gender, and the equation coefficients conform closely in sign and magnitude to theoretical values derived from C. W. Cobb and P. H. Douglas's (1928) theory of national economic productivity. Under a stringent causal probe, however, class and didactic quality of instruction appear to be the only unequivocal and potentially manipulable causes of science learning in the data. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Grain size and grain growth in an equiaxed alpha-beta titanium alloy

Methods of revealing grain size in a two-phase α-β titanium alloy have been examined and observations on beta grain growth in the presence of alpha have been carried out. The technique proposed by Greenfield and Margolin¹ for revealing β matrix grain sizes has been shown not to produce grain growth. However, for grain sizes of about 10 μm the G.M. technique does not reveal all the grains because of the similarity in orientation in neighboring grains. These clusters of similarly oriented grains are shown to persist as grain growth takes place but the misorientation between grains within a cluster decreases. Both the beta grain growth and alpha particle coarsening follow the same time dependency from which it is shown that a linear relationship exists between α particle size and β grain size. It is proposed that α particles must dissolve from theβ grain edges for β grain growth to occur. The linear dependency between beta grain size,D _β, and alpha particle size,d _α, can be rationalized either on the basis of geometrical or surface tension considerations. Formerly with New York University. Formerly Graduate Student with New York University.     

Rapidly prototyped three-dimensional nanofluidic channel networks in glass substrates

Microfluidic and nanofluidic technologies have long sought a fast, reliable method to overcome the creative limitations of planar fabrication methods, the resolution limits of lithography, and the materials limitations for fast prototyping. In the present work, we demonstrate direct 3D machining of submicrometer diameter, subsurface fluidic channels in glass, via optical breakdown near critical intensity, using a femtosecond pulsed laser. No postexposure etching or bonding is required; the channel network (or almost any arbitrary-shaped cavity below the surface) is produced directly from "art-to-part". The key to this approach is to use very low energy, highly focused, pulses in the presence of liquid. Microbubbles that result from laser energy deposition gently expand and extrude machining debris from the channels. These bubbles are in a highly damped, low Reynolds number regime, implying that surface spalling due to bubble collapse is unimportant. We demonstrate rapid prototyping of three-dimensional "jumpers", mixers, and other key components of complex 3D microscale analysis systems in glass substrates.     

Trace metals in ambient air: Hourly size-segregated mass concentrations determined by synchrotron-XRF

Trace metals are ubiquitous in urban ambient air, with mass concentrations in the range of a few microg/m3 down to less than 100 pg/m3. To measure such low concentrations represents a challenge for chemical and physical analysis. In this study, ambient aerosol was collected in Zürich (Switzerland) in 1-h intervals and three size fractions (aerodynamic diameters 0.1-1 microm, 1-2.5 microm, and 2.5-10 microm), using a three-stage rotating drum impactor (RDI). The samples were analyzed by energy-dispersive Synchrotron radiation X-ray fluorescence spectrometry (SR-XRF) to obtain size-segregated hourly elemental aerosol mass concentrations for Cr, Mn, Fe, Cu, Zn, Br, and Pb, along with S, Cl, and Ca under the selected experimental conditions. The high sensitivity of SR-XRF allowed for detection limits of <50 pg/m3 for most of the above elements, with a net analysis time of only 15 s per sample. The data obtained with this technique illustrate that there is a considerable gain of relevant information when time resolution for measurements is increased from 1 day to 1 h. The individual size fractions of a specific element may show significantly different short-term patterns.     

Secondary organic aerosol formation by irradiation of 1,3,5-trimethylbenzene-NOx-H2O in a new reaction chamber for atmospheric chemistry and physics

A new environmental reaction smog chamber was built to simulate particle formation and growth similar to that expected in the atmosphere. The organic material is formed from nucleation of photooxidized organic compounds. The chamber is a 27 m3 fluorinated ethylene propylene (FEP) bag suspended in a temperature-controlled enclosure. Four xenon arc lamps (16 kW total) are used to irradiate primary gas components for experiments lasting up to 24 h. Experiments using irradiations of 1,3,5-trimethylbenzene-NOx-H2O at similar input concentrations without seed particles were used to determine particle number and volume concentration wall loss rates of 0.209+/-0.018 and 0.139+/-0.070 h(-1), respectively. The particle formation was compared with and without propene.     

Effect of counselor technique on Mexican-American and Anglo-American self-disclosure and counselor perception.

A counseling analog study examined the effects of 3 interviewing techniques on 124 Mexican-American and Anglo-American undergraduates' willingness to self-disclose and perception of the counselor. The interviewing techniques manipulated were probing, disclosing, and reflecting. No differences across intervention techniques were found on the total scores of the disclosure questionnaire. Females disclosed less than males on the Body subscale of the disclosure questionnaire, but no ethnic differences in willingness to disclose were found. There were no differences in scores on the Barrett-Lennard Relationship Inventory (BLRI). Significantly more Ss in the probing than the reflecting condition indicated they would return for a 2nd interview. A positive correlation between willingness to disclose and scores on the BLRI was found. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Group psychotherapy with mastectomy patients.

Compared 20 women who participated in 10 weekly sessions of group psychotherapy with 20 women placed on a waiting list after they had mastectomies. Ss were matched on age (33–65 yrs old), marital status, time since surgery, prognosis, and SES. A structured, scaled interview was used to assess maladjustment, and 2 inventories were used to assess therapy outcome; all Ss were administered all measures before the treatment program began, when it finished 10 wks later, and 4 wks after the end of treatment. Results show that over the course of the therapy period, both groups showed changes in a positive direction; however, Ss in the treatment group showed significantly greater improvement. In the 4-wk follow-up period Ss in the treatment group continued to show significant positive change. (13 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)