An investigation of the growth-mechanism of Cr2O3 on pure chromium in 1 atm oxygen at 950° C

The growth mechanism of Cr₂O₃ scale formed when pure chromium was oxidized at 950°C in oxygen at 1 atm pressure has been investigated. Isotope tracer techniques were used to determine the growth sites of the oxide. The scale was buckled extensively, with the convex side always toward the gas, never the reverse. The following growth-mechanism is proposed. Initially growth occurs entirely by cation diffusion, with new oxide being formed at the oxide-gas interface. Then, at a time that is not the same for all parts of the scale, the growth mechanism changes to one in which new oxide is formed within the outer part of the scale.     

A note on the inadequacy of percentage grading scales for almost all ability distributions.

This study investigated distributions of letter grades (A,B,C,D,F) assigned to test scores according to the percentages adopted by Canadian universities, assuming realistic score distributions of ten different shapes with various means and standard deviations. The grade distributions corresponding to 83 out of 90 score distributions were highly anomalous, and the remaining 7 were far from ideal. Therefore, in the majority of practical testing situations, the percentage grading method is inadequate because of purely statistical properties of a scale based on fixed percentages. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Role of glandular scales of lepidote rhododendrons in insect resistance

Glandular scales on selected lepidote rhododendron species varied in density from 109 ± 13 to 4180 ± 60/cm² of leaf surface. Globules contained within the scales stained with Sudan IV, a lipophilic dye. Essential oil contents of the scales varied with species from 24 ± 8 to 151 ± 35 ng/scale. Black vine weevil [(Otiorhynchus sulcatus (F.)] feeding on leaves from a sample of rhododendron species was inversely related to leaf essential oil content, and weevil feeding on membrane filters was inhibited by application of essential oil extracts from leaves of most lepidote rhododendrons tested. Results suggest that the glandular scales of the lepidote rhododendrons function, at least in part, in plant defense against insects.Mention of a trade name or proprietary product does not constitute an endorsement by the U.S. Department of Agriculture, Agriculture Research Service.     

Dimensions of internalized object relations in borderline and schizophrenic patients.

This paper explores two dimensions of internalized object relations in borderline and schizophrenic patients using Rorschach scales. A thematic and a structural Rorschach measure of object relations is applied to the Rorschachs of two borderline groups (an infantile personality group and an obsessive-paranoid group) and a schizophrenic group. The findings suggest the value of both a multidimensional definition of internalized object relations and the use of such an approach to clarifying the diagnostic concept of borderline personality disorder. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A note on measurement scales and statistical tests.

The author defends the use of parametric tests (Boneau, 1960), and has been challenged on more than one occasion to justify the use of the t test in many typical psychological situations where there are measurement considerations. Intelligence is often given as an instance, the point being that intelligence is actually measured by an ordinal scale, that equal differences between scores represent different magnitudes at different places on the underlying continuum. This is seen as somehow invalidating the use of the t test with such scores. Burke (1953) has presented an argument which should have ended further discussion, but, in view of the present concern, a restatement of the argument and the addition of a few comments would seem indicated. The present concern seems to have been stimulated by the publication by psychologists of two texts in the field of statistics (Senders, 1958; Siegel, 1956) both of which are organized around Stevens' (1951) system of classifying measurement scales. Siegel and Senders belabor the point that parametric statistics, specifically the t and F tests should be avoided when the measurement scales are no stronger than ordinal, a state of affairs purportedly typical in psychology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A note on "Prognostic scales in schizophrenia".

An article on prognostic scales in schizophrenia by S. L. Garfield and D. M. Sundland (see record 1966-04456-001) is criticized and several ways in which it is misleading are pointed out. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Factor analysis of category and magnitude scales of a technical attribute.

36 journeymen electronics maintenance personnel judged the complexity of 16 avionics circuits using the paired-comparison, magnitude-estimation, rank-order, and constant-sum procedures on 2 occasions. The basic scale values were standardized across the 16 circuits separately within each method and occasion. The standardized scale values were then intercorrelated and factor analyzed to test the hypothesis that 2 factors would account for the data. After considering 1-, 2-, 3-, and 4-factor solutions, a 2-factor solution was chosen as best fitting the data. These 2 factors suggested the taxonomy of "congnitive discrimination" and "contextual uncertainty" to account for Ss' scaling behavior. Most frequently, the paired-comparison and the constant-sum methods were most heavily loaded on Factor 1, "cognitive discrimination." The rank-order and the magnitude-estimation methods were most consistently loaded heaviest on "contextual uncertainty," Factor 2. The findings are interpreted in terms of their relationship to certain customary scaling classificatory schemes. (24 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Generalized Thurstone and Guttman scales for measuring technical skills in job performance.

"Check lists for use in evaluating task performance in several related naval job specialities (ratings) were shown to meet the Thurstone and Guttman scalability requirements. The Scaled Technical Proficiency Check Lists evaluate the status of a technician with reference to tasks normally performed by men of equivalent pay grade and rating. The lists contain only a relatively small number of items, so that they are simple and convenient to use. Yet, because the tasks included form a scale, the score obtained from them can be generalized in meaning to the 'universe' of tasks of which they are representative." From Psyc Abstracts 36:04:4LD37S. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Validity of Dietary Restraint Scales: Reply to van Strien et al. (2006).

In T. van Strien, R. C. M. E. Engels, W. van Staveren, and C. P. Herman's (see record 2006-03905-010) comment, they contested the conclusion that dietary restraint scales are invalid measures of acute dietary restriction (E. Stice, M. Fisher, & M. R. Lowe, 2004). The authors respond to their concerns and conclude that researchers should (a) not have to work this hard to find evidence that these scales correlate with dieting restriction, (b) not settle for scales with only weak validity, and (c) use scales that are consistently valid across settings. The authors also discuss new evidence that most weight loss dieters are not achieving the negative energy balance necessary for weight loss, which seems to explain why these scales do not correlate inversely with caloric intake and why those with the highest dietary restraint scores gain more weight over time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Chromium transport through Cr2O3 scales. II. Changes in scale morphology during high vacuum treatment of oxidized chromium specimens

Chromium specimens oxidized at 1200 and 1300° O to give Cr₂O₃ scales with varying thicknesses have been high vacuum annealed for extended periods at temperature. During the high vacuum anneal chromium is transported through the scale and evaporates from the scale surface. Initially the rate of chromium evaporation decreases with time as a result of recrystallization and densification of the scale. On extended high vacuum treatment the rate of chromium evaporation again increases and major changes in scale morphology takes place. The outer scale surfaces develop hollows in the oxide grains while the grains protrude from the scale at the inner surfaces. The morphological changes are interpreted in terms of differences in diffusion rates along grain boundaries and through the lattice and resultant variations in surface energy along the surfaces.