DEM simulation of the packing structure and wall load in a 2-dimensional silo

The filling and discharge of a two-dimensional wedged-bottom silo holding circular objects was modelled using DEM technique to examine the influence of method of silo filling on distribution of orientations of unit vectors normal to contact points (contact normals) and normal contact forces. It was found that packing structure determined through method of generation of grain bedding significantly influenced distribution of contact normals. Nearly hexagonal network of contact normals was obtained for central filling of silo while sprinkle filling provided higher anisotropy of contact normals. The significance of frictional conditions and number of particles in system on distribution of contact normals was analysed. Increase in number of grains reduced disturbance from boundaries on behaviour of assembly. Distribution of loads on silo bottom obtained in simulation for different wall roughness was found in qualitative agreement with experimental data.     

Teaching elementary school students to identify story themes.

An instructional program focused on story theme was administered to 2nd and 3rd graders (high-, average-, and low-achieving students, including some with disabilities) in a high-poverty school. Compared with more traditional instruction, the program improved theme comprehension and the identification of instructed themes when they appeared in new stories. However, the program did not help students apply a theme to real-life situations or identify and apply noninstructed themes. Findings indicated that at-risk children (at all achievement levels, including those with disabilities) were able to achieve some degree of abstract, higher order comprehension when given instruction that combined structured lessons, a strategy, and discussion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The relationships between post-failure state and compression strength of sudetic fractured rocks

The behaviour of the Sudetic crystalline rocks in a pre- and a post-critical state of stress is the topic of this work. The pre-and post-critical failure energy ratio has been discussed, and the regression lines of residual strength of fractured rocks has been detrmined, based on which the residual strength (R_rez) and the standard compression strength (R_e) relationship was empirically determined as R_rez=0.18R_c+5.6;     

Effect of fabrication temperature on strain‐sensing capacity of polypyrrole‐coated conductive fabrics

Textile strain sensors were made from polypyrrole‐coated stretchable fabrics by a method of screen printing with chemical vapor deposition. The effect of polymerization temperature on the sensing performances was studied. It was found that polymerization at low temperature significantly improved the electrical conductivity, strain sensitivity and environmental stability of the fabric sensors. The conductive fabrics were characterized using X‐ray diffraction, thermogravimetry, contact angle measurements, particle size analysis, scanning electron microscopy and scanning probe microscopy. Powders of pure polypyrrole prepared by the same fabrication method were characterized for a better understanding of the polypyrrole coating. Copyright © 2007 Society of Chemical Industry     

Search for optimal geometry of a conical turbine agitator for heat transfer in stirred vessels

Simultaneous measurements of power consumption P and heat transfer coefficient α for a jacketed, baffled, agitated vessel of diameter D = 0.45 m, equipped with a conical turbine, were carried out. The following geometric parameters of the agitator were tested: diameter d, blade width b and number Z, and distance from the bottom of the vessel to the lower edge of the blade h. The results of these investigations were generalized mathematically. On the basis of optimization, the best geometric parameters with respect to heat transfer are proposed for the conical turbine agitator.     

Categorization, macrostructure, and finding the main idea.

Evaluated an inductive concept-identification model of expository text processing, consonant with current theories of macrostructure development, which was proposed as part of the basis of a model for instruction in reading comprehension, in a study of 24 4th graders (mean age 9.64 yrs) and 24 6th graders (mean age 11.81 yrs). It was found that the ability to identify sentences as appropriate for inclusion in short paragraphs depended on the number of detail sentences (category exemplars) in paragraphs that had no topic sentences (i.e., no explicit statement of the category) but not in paragraphs with topic sentences. Results support the model. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Rapid solidification processing

It has been over eight years since the subject of rapid solidification processing (RSP) has been given a general review. The early reviews of RSP were undertaken before the very rapid expansion of the late 1970s and early 1980s and the most recent general review was published in 1984, at approximately the height of RSP activity in the USA. More recent specialized reviews have been prepared for magnesium, titanium and aluminium alloys. The expansion of research and application testing resulted from the first major attempts to employ RSP on a large scale under both industrial and government sponsorship. The objective here is to develop the historical background of RSP, and then to update the present theoretical base for this technology. Examples of recent work on the rapid solidification of metals and ceramics will be given, along with examples of applications. Finally, an assessment of the future directions and prospects for RSP will be presented.     

Effects of distinctive features on recognition of incomplete pictures.

Conducted 2 experiments to determine the effects of distinctive features on recognition of incomplete pictures. Two sets of fragmented picture stimuli were designed: Set A preserved 75% and Set B preserved 25% of the distinctive features of the objects pictured. Within each set of stimuli, a complete (C), an intermediate (I), and a most incomplete (MI) representation of the objects was constructed. In Exp I, 60 Ss of 3 different age groups (3–4 and 5–6 yrs and undergraduates) were tested on the MI representations of either Set A or Set B. Results indicate significant differences in the age groups and in stimulus sets. In Exp II, 36 children (mean age 4 yrs 6 mo) were trained on either the C or the I Set A or the I Set B representations. After a day's delay, the Ss were tested on Set A or Set B MI representations of the objects and to novel representations. Results show significant differences among training conditions and in the test of the stimulus sets. The concepts of filtering and abstraction of distinctive features as discussed by F. J. Gibson (1969) are used in interpreting the results. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)