Showing papers by "University of Akron published in 1980"

New telechelic polymers and sequential copolymers by polyfunctional initiator‐transfer agents (inifers). VII. Synthesis and characterization of α,ω‐di(hydroxy)polyisobutylene

Abstract: Detailed understanding of the mechanism of initiation and chain transfer in BCl3-coinitiated isobutylene polymerization led to the efficient synthesis of symmetric telechelic polyisobutylenes carrying ∼CH2C(CH3)2Cl groups at either end of the molecule Cl-PIB-Cl. The synthesis is based on the use of inifers, i.e., bifunctional initiator-transfer agents that effect controlled initiation and propagation in the absence of chain transfer to a monomer. Specifically, the synthesis of Cl-PIB-Cl was achieved by the p-dicumyl chloride/BCl3/isobutylene/CH2Cl2 system. According to the inifer mechanism each Cl-PIB-Cl contains two terminal tertiary chlorines and one phenyl group at the interior of the chains. The structure of this new symmetric telechelic polymer has been established by detailed characterization studies including a sensitive new gel permeation chromatography (UV plus RI) analysis method, 1H-NMR, kinetic experiments, and chemical derivatization. The Cl-PIB-Cl molecule is a key intermediate for the synthesis of hosts of new materials, e.g., triblock copolymers, α,ω-diolefins, and α,ω-difunctional polymers.

Foreign bodies in the larynx and tracheobronchial tree in children. A review of 225 cases.

Abstract: In a study of 225 patients with foreign bodies in the larynx, trachea and bronchi, 77% were 36 months of age or less. The male-female ratio was 2:1. Food or food derivatives were the causative agent in 70% of the cases, with 38% due to a portion of nut. The foreign body involved the right and left bronchus with equal frequency. A choking episode followed by an audible wheeze (55%) was the most common presenting complaint. Obstructive emphysema was demonstrated in 60% and was best demonstrated by inspiration-expiration chest roentgenograms or fluoroscopy. A radio-opaque object was seen in 13%. Two hundred ten foreign objects (93%) were removed by endoscopy. Four patients required pulmonary resection for bronchiectasis and in three patients bronchotomy was performed. Five patients expelled the foreign body spontaneously, two patients were transferred to another hospital, and one foreign body was not recovered. There was no mortality.

Attitudinal Congruence and Similarity as Related to Interpersonal Evaluations in Manager-Subordinate Dyads

Abstract: This field study examined the relationship of both actual similarity and perceptual congruence with job satisfaction and performance evaluation in 194 manager-subordinate dyads. Among other finding...

Detachment of an elastic matrix from a rigid spherical inclusion

Abstract: An approximate theoretical treatment is given for detachment of an elastomer from a rigid spherical inclusion by a tensile stress applied to the elastomeric matrix. The inclusion is assumed to have an initially-debonded patch on its surface and the conditions for growth of the patch are derived from fracture energy considerations. Catastrophic debonding is predicted to occur at a critical applied stress when the initial debond is small. The strain energy dissipated as a result of this detachment, and hence the mechanical hysteresis, are also evaluated. When a reasonable value is adopted for Young's modulus E of the elastomeric matrix, it is found that detachment from small inclusions, of less than about 0.1 mm in diameter, will not occur, even when the level of adhesion is relatively low. Instead, rupture of the matrix near the inclusion becomes the preferred mode of failure at an applied stress given approximately by E/2. For still smaller inclusions, of less than about 1 μm in diameter, rupture of the matrix becomes increasingly difficult, due to the increasing importance of a surface energy term. These considerations account for the general features of reinforcement of elastomers. Small-particle fillers become effectively bonded to the matrix, whereas larger inclusions induce fracture near them, or become detached from the matrix, at applied stress that can be calculated from the particle diameter, the strength of adhesion, and the elasticity of the matrix material.

Expressed vocational choice and vocational indecision.

Abstract: This study equally divided 232 male and female college students into four groups based on their responses to the Occupational Alternatives Question. Groups were composed of subjects who had a first choice and no alternatives, a first choice plus alternatives, no first choice but alternatives, and neither a first choice nor alternatives. The hypothesis tested was that these groups would differ on dependent variables related to vocational decision making. No significant differences were found on socioeconomic status or on Holland's constructs of consistency, differentiation, or congruence with career choice. Significant group differences were found on congruence with college major, total number of Vocational Preference Inventory responses, and scales measuring satisfaction with college major and career choice. Significant differences were also found on two recent scales measuring vocational indecision, that is, the Vocational Decision Making Difficulty Scale and the Career Decision Scale. Significant sex differences indicated that females were more congruent and satisfied with their college majors. The results are discussed and their implications for future research and vocational counseling are examined. In the literature on vocational choice, the variable of expressed choice has recently been gaining increased research support. The definitive review by Dolliver (1969) perhaps gave impetus to the investigation of expressed choice, and at present an impressive number of studies exist which consistently indicate that expressed choices have predictive validity—in terms of college major or career choice—that equals or exceeds that of inventoried interests (Borgen & Seling, 1978; Dolliver & Will, 1977; Gade & Soliah, 1975; Gottfredson & Holland, 1975; Holland & Gottfredson, 1975; Holland & Lutz, 1968; O'Neil & Magoon, 1977; O'Neil, Magoon, & Tracey, 1978; Touchton & Magoon, 1977). The findings mentioned previously on expressed choice become additionally interesting relative to a number of studies that have attempted to measure differences be

Assimilation or Consciousness: Perceptions of U.S. Society Among Recent Latin American Immigrants to the United States

Abstract: Two competing views of determinants of immigrants' perceptions of U.S. society and perceptions of discrimination against their own group are examined. Assimilation theory suggests a process leading to lesser discrimination and a more favorable evaluation of the host society as immigrants' economic position, and their knowledge of the culture and language improve. More recent conflict theories indicate a possible reversal in this causal sequence: greater familiarity with the culture and language and some economic advancement can lead to greater consciousness of the reality of discrimination and a more critical appraisal of the host society. These competing perspectives are examined on samples of Cuban and Mexican immigrants interviewed at the moment of arrival in the U.S. and reinterviewed three years after. Bivariate and multivariate regression results are mixed, but lean definitely in the direction of the conflictlconsciousness hypothesis. A LISREL model of immigrants' perceptions of society and discrimination confirms the basic similarity of causal effects across the two immigrant groups and the general agreement of those effects with conflict theory predictions. Implications of these findings are discussed.

Thermoplastic elastomer blends

Abstract: Thermoplastic elastomer compositions of the present invention comprise a blend of from about 10 to about 50 parts by weight of a crystalline 1-olefin polymer, from about 80 to about 15 parts by weight of a styrene-butadiene rubber, and from about 5 to about 55 parts by weight of a highly saturated elastomer. The thermoplastic blends have very good physical properties, especially tear strength, tensile strength, elongation at break, low temperature impact resistance, minimum creep at high temperatures, and smooth surfaces when injection molded. The compositions, which may be partially cured, also have excellent aging properties, as well as paint adhesion. The compositions are a true thermoplastic in that they can be repeatedly processed and yet maintain their good physical properties.

The Rolling Loss of Pneumatic Tires

Abstract: Tire energy loss has long been neglected as an area of scientific concern, in favor of other performance characteristics such as traction and wear. With the advent of federally mandated fu...

The meaning and measurement of age identity.

Abstract: Lack of a broader theoretical framework and a relative neglect of measurement issues have hindered many previous studies of age identity. In this paper, a case is made for viewing age identity as a dimension of self-concept and two measurement techniques are empirically compared. The first is a single-item measure in which the individual chooses the age category which best suits him. The second is a semantic differential procedure which involves rating the referents "An Old Person", "A Middle-Aged Person", and "Myself" on identical bipolar adjectives. Data were obtained from 341 men and women, age 47 to 96, residing in central North Carolina. The results support the validity of the semantic differential technique, and also suggest that the two measures tap somewhat different dimensions of age identity. The single-item measure is closely related to chronological age, while the semantic differential is more strongly related to personal and social correlates of aging.

Age Differences in Free Recall Rehearsal Strategies

Abstract: Younger (mean age = 23.9 years) and older (mean age = 73.9 years) adults were compared on a free recall task with lists of categorizable words. One-half of the subjects were given instructions to rehearse overtly during list study, and the remainder received standard (covert) instructions. Relative to covert rehearsal, overt rehearsal did not appear to affect the type of study strategy used by subjects. Age differences in free recall and category clustering were found, paralleled by clear age differences in rehearsal strategies. Young adults' rehearsal was active, serially organized early in a list, and then categorically organized for the rest of a list. Older adults' rehearsal was inactive and essentially nonstrategic, consisting mostly of single mentions of each list item. These results also show that direct strategy measures provide more information about the processes underlying age differences in memory than do outcome measures alone.

Temperature effects on frequency preferences and mating call frequencies in the green treefrog,Hyla cinerea (Anura: Hylidae)

Abstract: 1. The frequency preferences of gravid females ofHyla cinerea for the low-frequency peak of bimodal synthetic mating calls shifted by about 400 Hz when the temperature of the animals was changed by about 7 °C. Changes in preference involving the high-frequency peak were much less dramatic (Table 1). 2. The low-frequency peaks of the mating calls of four individual males ofH. cinerea changed only slightly (≦70 Hz) when they were recorded at high and low temperatures (Table 2, Fig. 1). The same acclimation times (around one hour) were used in testing female preferences and in recording male calls at different temperatures. 3. Since shifts in female preference are not paralleled by concomitant changes in the spectral properties of the vocal signals, temperature coupling based on spectral information appears to be absent in the acoustic communication system of this species. 4. Spectral properties are important for species recognition and at low temperatures females prefer calls with low-frequency peaks that are more similar to those of another, sympatric species (Hyla gratiosa) than to those of conspecific males. This implies that species isolation in nature could be jeopardized at low temperatures if females become responsive to mating calls under these conditions. 5. Temperature effects on frequency preferences were predicted by a neurophysiological study of the auditory thalamic area inH. cinerea. The present results support the conclusion that this area is involved in processing biologically significant sounds. 6. The results indicate, however, that resonance properties of the buccal cavity alone are not sufficient to match the mating call frequencies with the frequency sensitivity of the auditory system.

Tire building machine

Abstract: A tire building machine otthe expandable bead lock type employs an elastomeric specially shaped radially expanding bead lock (43) including a shaping and turning bladder (48) which includes an air passage system therethrough. The elastomeric bead lock is confined for radial expansion in an annular outwardly opening chamber (114) in the form of an isos- celestrapezoid in radial section with the elastomeric bead lock being of similar configuration and expanded by direct application of air pressure within the chamber. The configuration of the annular chamber and the bead lock compensate for stretching of the bead lock upon enlargement. The edges of the bead lock atthe axial sides of the chamber are undercutfor flexibility while the walls (70,71) of the chamber are specially coated to maintain the seal. The bead lock incorporates interconnected metallic segment side plates (76, 77) which not only limit the stroke of the moving seal but insure stability axially of the bead and provide the desired concentricity. The bladder is pressurized through an annular air passage system and sealed conduit (137) extending radially through the pressure chamber inside the bead lock.

Determinants of Intrinsic Motivation: Locus of Control and Competence Information as Components of Deci's Cognitive Evaluation Theory

Abstract: The effects on intrinsic motivation of pay contingencies and amounts of competence information were investigated using a 2 x 2 factorial design with a sample of 56 male undergraduates performing a computer-simul ated lunar landing task. As predicted, the pay contingency manipulation significantly affected attributions of causality due to financial rewards. It had no effect, however, on a more generalized measure of causal attributions. Surprisingly, the competence information manipulation affected not only perceptions of competence but also this generalized attributional measure. Contrary to Deci's theory, however, behavioral indices of intrinsic motivation were unaffected by either manipulation. Rather, the data suggested that a broader perspective concerning the effects of attributions of causality and extrinsic factors on intrinsic motivation may be warranted. Although many classical theories of work motivation have either explicitly or implicitly assumed that the effects of intrinsic and extrinsic rewards were additive (e.g., Porter & Lawler, 1968; Vroom, 1964), recent evidence (Deci, 1971, 1972, 1975) suggests an interaction between these two sources of reward. According to cognitive evaluation theory (Deci, 1975), there are two potential effects associated with extrinsic rewards. They can be perceived as a source of competence information or as a means of behavioral control. As a source of information, extrinsic rewards confirm an individual's feelings of competence, which should increase intrinsic motivation. If extrinsic rewards are perceived as controlling agents, however, feelings of selfdetermination should decrease, reducing intrinsic motivation. Monetary rewards can serve either of these two functions, depending on how they are administered. Deci suggests that contingent financial rewards may be perceived as attempts at behavioral control; hence

Effects of drag reducing polymers on initiation of atherosclerosis

Abstract: Results from two pilot studies using White Carneau pigeons on high cholesterol diets have demonstrated substantial reduction in arterial plaque accumulations when the birds were periodically injected with dilute aqueous solutions of a drag reducing polymer (Separan AP-30) so as to maintain circulating blood concentrations of approximately 60 ppm. Initiation of arterial plaque formation may be fluid-mechanically motivated such that regions subjected to fluid turbulence, rapidly developing boundary layers, and alternate separation and reattachment, arc; the most prone lo attack. Viscoelastic fluid response, as seen in drag reducing media, is known to alter such phenomena. Comparative documentation of plaque deposition in experimental as well as control birds shows significant differences in both the aortas and coronary arteries, at optical magnifications from 20 to 15000X.

Carbon composite article and method of making same

Abstract: A carbon composite article and the method of making the article wherein selected carbon fibrous materials are formed into a basic starting substrate having a volume greater than the desired volume of the finished article. Very small amounts of a carbonaceous binder material are used to bond the fibrous materials together at a multiplicity of bonding sites. The basic substrate is then subjected to controlled temperatures and pressures to form a shaped substrate characterized by having a high degree of open porosity, a predetermined shape and structural integrity sufficient to withstand subsequent substrate processing. The carbonaceous binder is applied to the fibrous material in a manner whereby substantial encapsulation of the individual fibers is avoided so that the portions of the fibers disposed intermediate the bonding sites are free to move to accommodate and effectively distribute stresses which may be generated within the substrate due to material shrinkage or other process related causes. The shaped substrate is then partially or fully densified in a freestanding configuration by chemical vapor deposition of pyrolytic materials interstitially of the substrate.

Adjuvant chemotherapy, antiestrogen therapy and immunotherapy for stage II breast cancer: 45 Month follow up of a prospective, randomized clinical trial

Abstract: The results of adjuvant chemotherapy (CMF), endocrine therapy (t), and immunotherapy (BCG) in 318 women who had undergone mastectomy for Stage II breast cancer are reported after 45 months of life table analysis. CMFT therapy was found to be more effective than CMF alone in increasing recurrence-free survival. This beneficial effect appears to be limited to patients with estrogen receptor-positive tumors (ER+). Patients with estrogen receptor-negative tumors (ER-) (< 3 fmol/mg) have increased recurrence rates and higher mortality.

Do Goals Mediate the Effects of Incentives on Performance

Abstract: In 1968, Locke set forth the proposition that goals mediate the effects of incentives (eg, feedback, participation, and money) on performance Research is reviewed here to determine the extent to which Locke’s contention is supported We attempt to identify (1) individual and situational factors that may mediate the incentive-goal-performance relationship, and (2) integrate the literature We also offer a model and suggestions for future research

Solvent polymerization of carboxyl containing monomers

Abstract: Carboxyl or carboxyl salt containing polymers are prepared by polymerizing carboxyl containing monomers wherein greater than one percent of the carboxyl groups are neutralized with an alkali, ammonia or an amine, optionally copolymerized with other vinylidene monomers containing at least one terminal CH 2 ═CH< group dissolved in a solvent for the monomers which is a non-solvent for the polymer with a free radical catalyst, so that the resulting polymer is obtained suspended as a fine, readily recoverable substantially non-swollen fine powder. The solvents used are moderately to strongly hydrogen bonded and have solubility parameters of from about 8 to 15.

Die for extruding reinforced fabric

Abstract: A die (12) for extruding an elastomeric ribbon (14) reinforced with laterally spaced longitudinal filaments (13), said die having mating die blocks (17 and 18) enclosing mating die plates (15 and 16) embracing a filament guide insert (25), and said insert being undercut at (38) to form a flat surface (39) having exposed grooves (42) which are extensions of the filament guide passageways (26), whereby the exiting portions of the filaments (13) are partially encapsulated with elastomeric material while in said grooves (42).

Hydrogenated block copolymers of butadiene containing a block of 1,4 and a block of 1,2-microstructure

Abstract: The composition described herein is a hydrogenated polymer derived from a butadiene diblock copolymer having 85-100%, preferably 95-100% 1,2-structure in one block and the other block comprising essentially 1,4-butadiene. The 1,2-block comprises at least 10%, preferably at least 25%, of the total weight of the diblock copolymer. The hydrogenated product is an elastomeric material which is oxidation resistant and stable against ozone. Moreover, since the original polymer may be made by a method which permits control of the molecular weight, the molecular weight of the ultimate hydrogenated product is also controllable. The control of molecular weight and microstructure give highly desirable properties in the ultimate elastomeric product, and also control of tacticity and crystallinity.

Informational Cues and Individual Differences as Determinants of Subjective Perceptions of Task Enrichment

Abstract: The influences of both manipulated enrichment informational cues and individual differences on subjective job perceptions were examined. Results indicate that both the manipulation and individual d...

Dar al-Islam: The Evolution of Muslim Territoriality and Its Implications for Conflict Resolution in the Middle East

Abstract: Conflict and conflagration are not unique to the Middle East. Rare is the region where, at some point in history, disparate peoples have not clashed and killed. Attempts to assert primacy, when unsuccessful, have often led to periods of retrenching. When successful, postures of victory are precarious, subject to the transient recuperation of the vanquished.