Analysis of the phase partitioning of additives in rubber‐modified plastics

The phase partitioning of additives in polymer blends has a large impact on the performance of the blend. Therefore, it is necessary to be able to quantify the level of the additives in each phase. A ¹H–NMR method is presented to determine the partitioning of additives between the rubber and rigid phases of a high‐impact polystyrene (HIPS) material. In one case, a HIPS material was modified with 2,6‐di‐tert‐butyl‐4‐methyl‐phenol (Ionol, CAS# 128‐37‐OMF) as a stabilizer for both phases. HIPS materials with varying levels of Ionol were melt‐blended by extrusion and the total level of additives was determined analytically for these standard materials. The ¹H–NMR method was used to determine the level of Ionol in the poly(butadiene) rubber phase. The Ionol was found to preferentially partition into the rubber phase with a partition coefficient of about 2. A second example of the same concept, instead utilizing ¹³C–NMR, involved the analysis of the partition coefficient for both Tinuvin P and Tinuvin 770 (CAS# 2440‐22‐4 and 52829‐07‐9), partitioning between the rigid and rubber phases of an ethylene–propylene–diene‐modified (EPDM) toughened styrene–ran–acrylonitrile (SAN) copolymer. The partition coefficient was determined to be 0.5 for Tinuvin P and 1.3 for Tinuvin 770. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1963–1970, 2001     

Safety Evaluation for Campus Parking Garage Performance Using Fuzzy Logic

Crime has been plaguing parking garages in the United States. At The Ohio State University, (OSU) crime on campus, in general, has decreased in recent years; however, crime in OSU parking garages has remained stable in spite of campus-wide efforts to reduce crime. When assessing and evaluating parking garages, occupants employ experience-based judgment that is subjective and imprecise, yet extremely useful. When designers employ the principles of crime prevention through environmental design, they also use subjective variables. An approach that captures the imprecise information in noncrisp expressions reflecting subjective and experience-based variables is the fuzzy logic concept. This concept allows the use of mathematical operations to manipulate and operate on imprecise information or knowledge. Variables such as garage illumination and wall height were collected, fuzzified, and treated as the knowledge base of a model presented in this paper. In addition, numerous experience-based implication rules were developed and employed to evaluate subjective variables. A computer program was developed to illustrate implementation of the model.     

Public attitudes toward political and technological options for biofuels

This paper explores detailed public attitudes regarding the expanding range of biofuels technologies and policy options. Subjects from 34 in-depth focus groups in central Indiana were fairly knowledgeable about biofuels technologies, but uninformed about biofuels policies despite being from a state where biofuels are a salient political issue. A narrow majority was supportive of biofuels in general, but expressed greater enthusiasm about “second generation” biofuels. Subject beliefs about biofuels’ economic and environmental impacts were most important in shaping these opinions, rather than concerns about energy independence or other issues. In terms of policy options, subjects were most supportive of an alternative fuels standard and least supportive of a fixed subsidy and a cap and trade policy. In contrast to arguments about technologies, participants primarily framed their attitudes toward policies in terms of fairness. Although discussion did not substantially change aggregate preferences for most policies, it did increase support significantly for at least one policy proposal—a variable subsidy for ethanol. It is particularly noteworthy that subjects generally did not support the most common biofuel technology—corn-based ethanol—or the most prominent biofuels policy option—the fixed subsidy—despite residing in a state hosting a strong corn industry and staunch political advocates for both positions.     

Effectiveness of neural network types for prediction of business failure

The study examines the effectiveness of different neural networks in predicting bankruptcy filing. Two approaches for training neural networks, Back-Propagation and Optimal Estimation Theory, are considered. Within the back-propagation training method, four different models (Back-Propagation, Functional Link Back-Propagation With Sines, Pruned Back-Propagation, and Cumulative Predictive Back-Propagation) are tested. The neural networks are compared against traditional bankruptcy prediction techniques such as discriminant analysis, logit, and probit. The results show that the level of Type I and Type II errors varies greatly across techniques. The Optimal Estimation Theory neural network has the lowest level of Type I error and the highest level of Type II error while the traditional statistical techniques have the reverse relationship (i.e., high Type I error and low Type II error). The back-propagation neural networks have intermediate levels of Type I and Type II error. We demonstrate that the performance of the neural networks tested is sensitive to the choice of variables selected and that the networks cannot be relied upon to “sift through” variables and focus on the most important variables (network performance based on the combined set of Ohlson and Altman data was frequently worse than their performance with one of the subsets). It is also important to note that the results are quite sensitive to sampling error. The significant variations across replications for some of the models indicate the sensitivity of the models to variations in the data.     

Rhesus monkeys (Macaca mulatta), video tasks, and implications for stimulus-response spatial contiguity.

Recent reports (Iwai, Yaginuma, & Mishkin, 1986; Yaginuma & Iwai, 1986) have supported the earlier conclusion by Meyer, Treichler, and Meyer (1965) and by Stollnitz (1965) that the efficiency of primate learning is compromised to the degree that there is spatial discontiguity between discriminanda and the locus of response. The research reported in this article calls for a reconsideration of this conclusion. Two rhesus monkeys (Macaca mulatta) easily mastered precise control of a joystick to respond to a variety of computer-generated targets despite the fact that the joystick was located 9 to 18 cm from the video screen. We hold that stimulus–response contiguity is a significant parameter of learning only to the degree that the monkey visually attends to the directional movements of its hand in order to displace discriminanda as in the Wisconsin General Test Apparatus. If, instead, attention is focused on the effects of the hand's movement rather than on the hand itself, stimulus–response contiguity is no longer a primary parameter of learning. The implications of this work for mirror-guided studies are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Self-efficacy and outcome expectancy mechanisms in reading and writing achievement.

Examined the relation between self-efficacy and outcome expectancy beliefs and achievement in reading and writing. Most of the 153 subjects were White, middle-class undergraduate students. Efficacy for reading and writing tasks and component skills and outcome expectancies that reading and writing are important for realizing life goals were assessed. Reading achievement was measured by the Degrees of Reading Power test and writing achievement was measured by a holistically scored writing sample. Results from regression analysis indicated that self-efficacy and outcome expectancy beliefs jointly account for significant variance in reading achievement with self-efficacy being the stronger predictor and that self-efficacy, but not outcome expectancy, accounts for significant variance in writing achievement. Canonical correlation analysis identified a single underlying dimension linking beliefs and achievement for reading and writing, with reading beliefs and achievement contributing most strongly to the relation. Results are discussed as they relate to previous research and needed areas of future study. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Summation in the chimpanzee (Pan troglodytes).

In this research, we asked whether 2 chimpanzee (Pan troglodytes) subjects could reliably sum across pairs of quantities to select the greater total. Subjects were allowed to choose between two trays of chocolates. Each tray contained two food wells. To select the tray containing the greater number of chocolates, it was necessary to sum the contents of the food wells on each tray. In experiments where food wells contained from zero to four chocolates, the chimpanzees chose the greater value of the summed wells on more than 90% of the trials. In the final experiment, the maximum number of chocolates assigned to a food well was increased to five. Choice of the tray containing the greater sum still remained above 90%. In all experiments, subjects reliably chose the greater sum, even though on many trials a food well on the "incorrect" tray held more chocolates than either single well on the "correct" tray. It was concluded that without any known ability to count, these chimpanzees used some process of summation to combine spatially separated quantities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Children's perceptions of the personal relationships in their social networks.

Tested the hypothesis that children would report that different social-network members provide different social provisions, using 199 5th–6th grade White children. Ss completed network of relationships inventories, which assessed 10 qualities of their relationships with mothers, fathers, siblings, grandparents, friends, and teachers. Consistent with R. S. Weiss's (1974) theory (i.e., that individuals seek specific social provisions or types of social support in their relationships with others), Ss reported seeking different provisions from different individuals. Mothers and fathers were turned to most often for affection, enhancement of worth, a sense of reliable aid, and instrumental aid. Next to parents, grandparents were turned to most often for affection and enhancement of worth, and teachers were turned to most often for instrumental aid. Friends were the greatest source of companionship, and friends and mothers received the highest ratings of intimacy. Ss also reported having more power in their relationships with other children than in those with adults. Conflict was perceived as occurring most often in sibling relationships. Ss were most satisfied with their relationships with mothers, and they thought their relationships with mothers and fathers were the most important. Bases for children's differentiations of their relationships and implications for understanding social networks are discussed. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Issues in the Processing of Cuprate Ceramic Superconductors

A number of the important issues in the processing of dense, superconducting ceramics are addressed and illustrated with examples drawn from our studies of the processing of yttrium barium cuprate. Among the phenomena affecting the attainment of dense, fully superconducting materials are those common to the processing of other ceramics, namely, control of composition, prevention of microcracking, adequate time for the decomposition, and escape of intermediaries prior to surface densification (the so-called "binder burn-off" problem). Additional requirements include the necessity to ensure complete oxygenation throughout the microstructure for full volume superconductivity and the control of texture development for maximizing the attainable transport critical current density. On the basis of the processing issues described, it is concluded that the optimum microstructure is one having finescale, interconnected porosity (to ensure escape of carbonate-like species and subsequent, rapid oxygenation) with a fine grain size (∼1 μm) to avoid microcracking.     

Video-task assessment of learning and memory in macaques (Macaca mulatta): Effects of stimulus movement on performance.

Effects of stimulus movement on learning, transfer, matching, and short-term memory performance were assessed with 2 monkeys using a video-task paradigm (VTP) in which the animals responded to computer-generated images by manipulating a joystick. Performance on tests of learning set, transfer index, matching to sample, and delayed matching to sample in the VTP was comparable to that obtained in previous investigations using the Wisconsin General Testing Apparatus (D. M. Rumbaugh et al, 1989). Additionally, learning, transfer, and matching were reliably and significantly better when the stimuli or discriminanda moved than when the stimuli were stationary. External manipulations such as stimulus movement may increase attention to the demands of a task, which in turn should increase the efficiency of learning. Findings have implications for the investigation of learning in other populations, as well as for the application of the VTP to comparative study. (PsycINFO Database Record (c) 2010 APA, all rights reserved)