Bulk and Surface Properties of Liquid Al-Li and Li-Zn Alloys

Physicochemical properties like density, surface tension, and viscosity of liquid binary Al-Li and Li-Zn alloys have been measured using draining crucible method. The experimentally measured surface-tension values have been compared to theoretical results based either on the Butler model or the compound formation model assuming the existence of the most favored A ₁ B ₂ and A ₂ B ₃ clusters. Several models for viscosity calculation have been also applied and discussed in confrontation with measured data. Finally, the clustering effects in the liquid Al-Li and Li-Zn alloys have been examined using two microscopic functions, i.e., the concentration fluctuation function in the long-wavelength limit and the Warren-Cowley short-range order parameter.     

A study of the rheological behavior of high‐temperature polymer electrolyte membrane solutions

The viscosity behavior of various compositions of polymer electrolyte membrane solutions, which are later hydrolyzed into proton conducting membrane film for fuel cells, is characterized. Using the Carreau‐Yasuda model and time–temperature superposition, an empirical model relating the viscosity as a function of temperature and shear strain rate has been developed for several membrane solution compositions. It is observed that the viscosity of the non‐Newtonian membrane has a strong correlation to the membrane's inherent viscosity (a property determined during membrane synthesis). © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Is the failure to monitor comprehension an instance of cognitive impulsivity?

Third and fifth graders' ability to monitor comprehension was measured with the error detection paradigm. Subjects read three passages, each containing incongruent information. Subjects' performance at detecting these contradictions was recorded. Subjects were also given a multiple-choice recall/comprehension test after each passage. Cognitively reflective and impulsive children were identified with the Matching Familiar Figures Test (MFF). Reflective children detected significantly more inconsistencies than impulsive children across grade levels. Although there were no significant reflective-impulsive differences on the overall recall/comprehension test, reflectives recalled significantly more information necessary for identifying the inconsistencies. These results are interpreted in an analytic-global processing framework. It is argued that comprehension monitoring failure of impulsives is in part due to their failure to adopt a suitable analytic reading strategy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modeling Immune Building Systems for Bioterrorism Defense

This paper presents the results of research on the performance of air-cleaning and air-disinfection systems used for protecting buildings against intentional releases of biological agents. The air-cleaning technologies addressed include dilution ventilation, filtration, and ultraviolet germicidal irradiation. A 40-story commercial office building is modeled using typical occupancy levels and leakage rates for doors, walls, and floors. A steady-state single-zone model is used to predict steady-state conditions resulting from the use of various levels of air cleaning. A transient single-zone model is used to predict transient indoor concentrations from which inhaled doses and estimated casualties are predicted. A transient multizone model is used to evaluate contaminant dispersion and estimate potential casualties. Three design-basis attack scenarios are simulated using various biological weapon agents. Predicted casualties are estimated using an epidemiological model of the dose response curves for each of the agents. The effect of increasing levels of air cleaning is examined under the attack scenarios to evaluate their effectiveness. Results indicate that high levels of protection are possible for building occupants with moderate and affordable levels of air cleaning when filtration is combined with ultraviolet germicidal irradiation. Results also suggest that diminishing returns occur when increased levels of air cleaning are applied. It is hypothesized that the maximum useful size of any air-cleaning system is defined and limited by building physical characteristics alone.     

Standard atomic weights of the elements (1988)

Standard atomic weights of the elements (1988)     

Relation among error detection, sentence verification, and low-level reading skills of fourth graders.

The author explored the relation among low-level reading skills, sentence verification, and error detection in 4th graders. Literal text comprehension was measured with the Sentence Verification Technique (J. M. Royer, in press) procedure. A higher (strategic) level of text comprehension was assessed with the error detection paradigm. Thus low- and high-level text comprehension were correlated with low-level reading skill: decoding, lexical access, verbal working memory span, and each other. Although literal text comprehension and low-level reading measures were correlated, both were uncorrelated with error detection. A second study deomonstrated that 4th graders' error detection was best predicted by their tendency to generate inferences while reading. These data suggest that although literal text comprehension is dependent on low-level reading processes, strategic reading competence reflects the 4th grader's tendency to go beyond literal information in a text. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A low-cost Mr compatible ergometer to assess post-exercise phosphocreatine recovery kinetics

Objective

To develop a low-cost pedal ergometer compatible with ultrahigh (7 T) field MR systems to reliably quantify metabolic parameters in human lower leg muscle using phosphorus magnetic resonance spectroscopy.

Materials and methods

We constructed an MR compatible ergometer using commercially available materials and elastic bands that provide resistance to movement. We recruited ten healthy subjects (eight men and two women, mean age ± standard deviation: 32.8 ± 6.0 years, BMI: 24.1 ± 3.9 kg/m²). All subjects were scanned on a 7 T whole-body magnet. Each subject was scanned on two visits and performed a 90 s plantar flexion exercise at 40% maximum voluntary contraction during each scan. During the first visit, each subject performed the exercise twice in order for us to estimate the intra-exam repeatability, and once during the second visit in order to estimate the inter-exam repeatability of the time constant of phosphocreatine recovery kinetics. We assessed the intra and inter-exam reliability in terms of the within-subject coefficient of variation (CV).

Results

We acquired reliable measurements of PCr recovery kinetics with an intra- and inter-exam CV of 7.9% and 5.7%, respectively.

Conclusion

We constructed a low-cost pedal ergometer compatible with ultrahigh (7 T) field MR systems, which allowed us to quantify reliably PCr recovery kinetics in lower leg muscle using ³¹P-MRS.

     

Geographic Variation in Acadian French /r /: What Can Correspondence Analysis Contribute Toward Explanation?

This article presents elements of a Correspondence Analysis(CA) approach to the measurement of linguistic distances indialectology. It argues that both linguistic and spatial factorsare part of an explanation of geolinguistic variation, and itshows how the exploratory and graphical properties of CA cancontribute to such an explanation. The application is a studyof the different realizations of the phoneme /r/ in AcadianFrench, a dialect spoken in Canada. Data are from the Atlaslinguistique du vocabulaire maritime acadien and include over5,000 tokens from eighteen localities. Using chi-square distances,the analysis results in a two-dimensional space that arrangesthe localities along continua. Linguistic interpretation ofthis space, based on those features of /r/ that are identifiedas accounting for the structuring of these continua, suggestsa hierarchy of phonological processes—including alternationbetween apical and dorsal articulations (in French words), andreplacement of the retroflex rhotic found in English-originwords by apical and dorsal variants. Two external spatial factors,local concentration of francophone speakers and spheres of activity,are shown to correlate with the linguistic distances among localities.     

Interfacial activity of 4-alkylphenylamines and the rate of palladium(II) extraction

Interfacial tension isotherms were determined in hydrocarbon-water systems for 4-alkylphenylamines containing from 6 to 16 carbon atoms in their alkyl chains, and the surface excess isotherms were computed and interpreted using various adsorption isotherms. Palladium(II) was extracted with 4-alkylphenylamines from 3 M HCI solutions. The maximum extraction rate of palladium(II) is observed for 4-decyl- and 4-dodecylphenylamines which exhibit good interfacial activity. Compounds soluble in the aqueous phase (4-hexylphenylamine) or in toluene (4-hexadecylphenylamine) extract palladium(II) slower than 4-decyl- and 4-dodecyl- phenylamines.