bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dyadic Communication Relationships in Organizations: An Attribution/Expectancy Approach
Authors: Barry Bruce , Crant J. Michael 
Published: April 2003

Research in organizational communication has examined the structure and content of interaction, but has paid little attention to research traditions outside the organizational sciences that explore the social-psychological interconnections between relationship development and interaction. In this paper we draw upon and extend those traditions to develop a model of how communication relationships develop within organizational dyads. The proposed model examines organization-based communication relationships through a synthesis of theoretical perspectives on communication richness, relational communication, interpersonal attribution, and social expectancy. We also call upon precepts of structuration theory to embed these microlevel processes in an organizational context. The relational outcome in the model is “interactional richness,” a dyad-level construct that assesses the extent to which communication within the dyad is high in shared meaning. Model antecedents are aspects of interaction through which communicators reciprocally define their relationships, including relational message properties, message patterns that emerge over time, and relational perceptions. We propose that these communication properties and behaviors give rise to relationship attributions. We then incorporate processes of expectancy confirmation and violation to explain how specific communication encounters lead individuals to reformulate attributions regarding the status of a given relationship. Research propositions articulate how attribution/expectancy processes mediate between relational communication behavior and relationship development outcomes. We also develop propositions addressing how relational communication behavior is influenced by macrolevel factors, including hierarchy, structure, and culture. In a concluding section we discuss the model's potential contribution to research and practice, address its limitations, and offer recommendations for future research aimed at testing its embedded hypotheses.
Screening and Management of Adult Hearing Loss in Primary Care
Authors: Yueh Bevan , Shapiro Nina , MacLean Catherine H. , Shekelle Paul G. 
Published: April 2003

ContextHearing loss is the third most prevalent chronic condition in olderadults and has important effects on their physical and mental health. Despitethese effects, most older patients are not assessed or treated for hearingloss.ObjectiveTo review the evidence on screening and management of hearing loss ofolder adults in the primary care setting.Data Sources and Study SelectionWe performed a search from 1985 to 2001 using MEDLINE, HealthSTAR, EMBASE,Ageline, and the National Guideline Clearinghouse for articles and practiceguidelines about screening and management of hearing loss in older adults,as well as reviewed references in these articles and those suggested by expertsin hearing impairment.Data ExtractionWe reviewed articles for the most clinically important information,emphasizing randomized clinical trials, where available, and identified 1595articles.Data SynthesisScreening tests that reliably detect hearing loss are use of an audioscope,a hand-held combination otoscope and audiometer, and a self-administered questionnaire,the Hearing Handicap Inventory for the Elderly-Screening version. The valueof routine screening for improving patient outcomes has not been evaluatedin a randomized clinical trial. Screening is endorsed by most professionalorganizations, including the US Preventive Services Task Force. While mosthearing loss in older adults is sensorineural and due to presbycusis, cerumenimpaction and chronic otitis media may be present in up to 30% of elderlypatients with hearing loss and can be treated by the primary care clinician.In randomized trials, hearing aids have been demonstrated to improve outcomesfor patients with sensorineural hearing loss. Nonadherence to use of hearingaids is high. Prompt recognition of potentially reversible causes of hearingloss, such as sudden sensorineural hearing loss, is important to maximizethe possibility of functional recovery.ConclusionWhile untested in a clinical trial, older adults can be screened forhearing loss using simple methods, and effective treatments exist and areavailable for many forms of hearing loss.
Influence of some anthropometric parameters on the risk of development of distal complications after mastectomy carried out because of breast carcinoma
Authors: Kopanski Zbigniew , Wojewoda Tomasz , Wojewoda Aleksandra , Schlegel‐Zawadzka Malgorzata , Wozniacka Renata , Suder Agnieszka , Kosciuk Tomasz 
Published: April 2003

AbstractThe analysis included 46 women after radical breast amputation because of cancer with which lymphoedema occurred in the upper limb, as well as 51 women in whom no lymphoedema occurred during the period of the observation. Both groups were subjected to a comparative analysis as for height, body mass, and weight–height indexes: BMI, Quetelet, Rohrer, and Pignet–Verwaeck. The results show that women with high body mass, obesity (BMI > 30.0), and high values of the Quetelet (>370), Rohrer (>1.59), and Pignet–Verwaeck (>93.1) indexes are threatened to a significant degree with lymphoedema of the upper limbs after cancer‐related mastectomy. On the other hand, slim body build and low index values appear to be a factor protecting from the occurrence of lymphoedema of the upper limb. Am. J. Hum. Biol. 15:433–439, 2003. © 2003 Wiley‐Liss, Inc.
Participation of women in Human Biology, 1975–2001
Authors: Stinson Sara 
Published: April 2003

AbstractThis study examines trends in women's participation in human biology as indicated by women's membership in the Human Biology Council/Association, first authorship of articles in the Human Biology Council/Association journal, and the extent to which women have been the subjects of research published in the organization's journal. Gender of members was determined from seven membership lists published in the organization's journal from 1977 to 1998, and the gender of the first authors was determined for 1,616 articles published in Human Biology or the American Journal of Human Biology from 1975 to 2001. Each journal article was also coded as to the first author's country and whether the subjects of the research were only females, only males, or both males and females. From the late 1970s to the late 1990s, the percent of women members of the Human Biology Council/Association increased from under 25% to over 40%. Women were the first authors of fewer than 20% of articles in the organization's journal in the late 1970s; by the late 1990s over 30% of articles had a female first author. The clearest increase in female authorship through time is seen for articles with a first author from the U.S. Even when women were not well represented as human biologists, a substantial proportion of human biology research published in the organization's journal dealt with females, and over the last 15 years there have been more research articles having only females as research subjects than articles having only males as research subjects. Am. J. Hum. Biol. 15:440–445, 2003. © 2003 Wiley‐Liss, Inc.
Redox recipes. X. A recipe with ferric versenate, sodium dithionite, and hydroperoxide as activating system (veroxathionite recipe)
Authors: Kolthoff I. M. , Meehan E. J. 
Published: April 2003

AbstractA new initiating system, named the Veroxathionite system, for the copolymerization of butadiene (75)‐styrene (25) is described. At 0°C., with the recipe: butadiene, 75 parts; styrene, 25 parts; water, 180 parts; potassium myristate, 5 parts; potassium pyrophosphate, 1 part; sulfole mercaptan, 0.3 part; 0.66 mmole of phenylcyclohexane hydroperoxide, 0.001 M ferric versenate, and 0.1 part of sodium dithionite, conversions of 45, 87, and 100% were reached in 1, 2, and 3 hours, respectively. The rate can be varied within wide limits by changing the concentration of iron. With only 10−4 M ferric versenate and 0.06 part of dithionite, 71% conversion is attained in 12 hours. The amount of dithionite must be adjusted to the amount of hydroperoxide and, to a lesser extent, to the amount of iron. With much more than one mole of dithionite per mole of hydroperoxide, dead‐stops occur at low conversion due to exhaustion of hydroperoxide. The rate is determined by the concentration of ferric versenate, and an excess of versene over ferric iron has no effect. The addition of potassium pyrophosphate yields a latex which is of normal fluidity and free of precoagulation up to 80% conversion. The effects of polymerization variables are described. With methanol as antifreeze, a recipe is described which yields 75% conversion in 8 hours at −20°C. The reaction mechanism is very involved. It is concluded that an induced reaction between hydroperoxide and dithionite is responsible for the low efficiency of the radicals produced in this recipe.
Dynamics of loosely crosslinked polymer networks
Authors: Bueche F. 
Published: April 2003

AbstractAn ideal crosslinked rubber will reach an equilibrium elongation soon after a constant tensile stress has been applied to it. Actual materials never reach an equilibrium strain in many cases. This fact is clarified by studying the creep curves for molten polyethyl methacrylate crosslinked with varying amounts of ethylene dimethacrylate. A quantitative theory for the observed effects is presented. It shows that the slope of the long time portion of the creep curve is dependent primarily on a parameter which characterizes the number of effective chains emanating from a network branch point. Reasonable agreement between theory and experiment is found.
The reaction of sulfur and sulfur compounds with olefinic substances. Part XII. Effects of vulcanizing additives on the reaction of sulfur with 2,6‐dimethylocta‐2,6‐diene, and their bearing on the mechanism of sulfur vulcanization of natural rubber
Authors: Bateman L. , Glazebrook R. W. , Moore C. G. 
Published: April 2003

AbstractThe effects of zinc oxide, of zinc oxide and stearic acid, and of zinc oxide, stearic acid, and 2‐mercaptobenzothiazole on the products of interaction of sulfur with the diisoprene, 2,6‐dimethylocta‐2,6‐diene at 140°C. have been investigated in detail. Zinc oxide alone produces little change in the composition of the complex product mixture, but in the presence of stearic acid, and more so when the thiazole is also present, significant changes are produced in the distribution of combined sulfur which reflect more efficient use of the sulfur in crosslinking reactions, and which can be related rationally to important effects exerted by these additives on the sulfur‐vulcanization of natural rubber. It has recently been advanced that sulfur‐olefin interaction proceeds by a polar mechanism in which the dominant feature is the additive reactivity of persulfenium ionic species (T) towards double bonds. Evidence is now presented that the chemical and technological effects of soluble zinc salts and of thiazole accelerators stem from their action in enhancing the role of reactions promoted by the complementary persulfenyl anionic species (T) which involve the displacement of hydrogen from, and the addition of sulfur to, carbon atoms adjacent to double bonds. Essentially similar mechanistic considerations appear to apply to systems accelerated by amines and by metal dithiocarbamates and xanthates.
Latex thickening: Interactions between aqueous polymeric dispersions and solutions
Authors: Brown George L. , Garrett B. S. 
Published: April 2003

AbstractLatex thickening—the process of increasing the viscosity of a polymer emulsion by addition of a water‐soluble polymer —has been studied by rheological measurements and by the examination of other colloidal properties. For the systems studied, which represent a range of polymers in both the dispersion and solution phases, the flow curves were represented over a wide range of shear rate by the equation, S = K(τ − τ0)2, where S is shear stress, τ is shear rate, and K and τ0 are constants, of which the latter is considered to be a yield stress. Aside from the generality of the mathematical function, the behavior of various latex‐thickener pairs is extremely specific to the pair involved. Additional data on latex creaming and on the influence of the thickener and latex concentrations confirms the specificity. The available data indicate that latex thickening is not simply an enhancement of the viscosity of the aqueous phase by the thickener, but that in addition to this the ability of the thickener to flocculate or deflocculate the latex is an important part of the mechanism of thickening. These colloidal interactions change, often precipitously, with minor changes in the polymers, the latex emulsifier, and the concentrations of the components.
The stability of fluorine‐containing polymers to amines
Authors: Bro M. I. 
Published: April 2003

AbstractThe reactivity of hydrofluorocarbon polymers toward organic amines increases, generally, with increasing fluorine content and with increasing basicity of the amine. The position of fluorine in the molecule with respect to hydrogen strongly affects the electrophylic character of the hydrogen atom. A discussion of the effects of neighboring groups on this reactivity is presented.
Diffusion of small molecules in semicrystalline polymers: Water in polyethylene
Authors: Klute C. H. 
Published: April 2003

AbstractPublished data on the solubility properties and diffusion coefficients for water in polyethylene are critically examined and related to the permeability coefficients analyzed in a previous paper. The data examined in the present article are even more variable than the permeability data, the measured diffusion coefficients varying over a fourteenfold range. Solubilities vary less from specimen to specimen but do so in an order opposite to that of the diffusion coefficients. Accordingly the permeability coefficients vary much less than do the diffusion coefficients. In an examination of the permeation process, as it must occur through semicrystalline polymer films, it is demonstrated that a systematic error is introduced if permeation through such films is described by means of equations developed for homogeneous materials. The error has been evaluated by means of an electrical analog and equations describing diffusion in semicrystalline polymers are derived which complement those already in existence for diffusion in homogeneous polymers. By means of these equations it is shown that the variations in permeability and diffusion coefficients cannot be explained on the basis of reasonable variations in the amount of crystallinity between otherwise comparable polymers or by reasonable variations in the way in which the crystalline regions occur in the amorphous matrix. The conclusion previously reached to the effect that variations in the structure of the amorphous phase from specimen to specimen are responsible for irreproducible transport properties still appears valid.
Transition behavior of polychloroprene and polychloroprene/styrene‐butadiene blends
Authors: Kell R. M. , Bennett Bailey , Stickney P. B. 
Published: April 2003

AbstractDilatometric studies have been carried out to determine crystallization and glass transition data for various unvulcanized and vulcanized polychloroprenes and polychloroprene/styrene‐butadiene blends. The maximum rate of crystallization of both unvulcanized polychloroprene and the blends occurred near −5°C. Melting temperatures of the polychloroprenes ranged from 36 to 43°C. The glass transition temperature of all polychloroprenes studied was near −45°C., and this was lowered to −50°C. with the addition of 30 pph of SBR‐1500. The added SBR polymer retarded the rate and ultimate degree of crystallization somewhat.
Studies on the orientation phenomena by fiber formation from polymer melts. Part I. Preliminary investigations on polycapronamide
Authors: Ziabicki Andrzej , Kedzierska Krystyna 
Published: April 2003

AbstractThe problem of the mechanism of macromolecule orientation occurring in the formation of fibers from polymer melts has been qualitatively analyzed. As a result of birefringence, x‐ray, and spinning stress investigations carried out on polycapronamide fibers, the main parameters determining orientation have been established. They are the parallel velocity gradient along the spinning length, G = dV/dl, and the relaxation factors. The deformation ratio S (the ratio of final to original linear velocity), analogous to the draw ratio λ = 1/10 in the cold‐drawing process, has no influence on the degree of orientation. The orientation by spinning is not accompanied by any such structural transformations as occur through cold‐drawing. The fibers spun at high velocity gradients consist of well‐oriented β‐polycapronamide. It is thus assumed that the orientation proceeds in the region of the liquid melt‐stream as a result of simultaneous action of velocity gradient and thermal relaxation. This mechanism, analogous to that causing the familiar streaming orientation of polymer solutions in capillaries or in a Couette apparatus, is different in principle from that of the cold‐drawing process.
The dynamic mechanical properties of nylons
Authors: Kawaguchi T. 
Published: April 2003

AbstractA study of the dynamic mechanical properties of a series of polyamide polymers and some related polymers has been made over a wide temperature range at about 100 cycles/sec. by means of a vibrating reed method. The character of the β dispersion of the polyamides occurring at about −40°C. is discussed in relation to the chemical structure of the polymers particularly to the amide groups. It is shown that the β dispersion of the linear condensation polymers of this type is influenced by the properties of the polar groups in the molecular chains. The data supports the view recently postulated by Woodward and his co‐workers that the β peak in the polyamides is due to a segmental motion involving nonhydrogen‐bonded amide groups. Finally the correlation between the γ process occurring at about −120°C. and molecular structure is discussed.
Crystallization and orientation of isotactic polypropylene film by stretching
Authors: Sobue Hiroshi , Tabata Yoneho 
Published: April 2003

AbstractCrystallization and orientation of isotactic polypropylene film by stretching were investigated. The specimen used was a film of thickness 0.03 mm. and had ca. 30% crystallinity in the initial state. It was observed both by x‐ray examination and measurement of density that the crystallization of the stretched film increased proportionally to the stretching ratio. And it was confirmed that a quasi‐crystalline structure was already developed in the low stretching ratio coexisting with the ordinary stable crystalline structures. This quasi‐crystal structure can be easily transformed into the ordinary stable state at above 100°C., as well as the quasi‐crystal structure in melt spinning filament, as described in a previous paper. It was also confirmed that the ordinary stable crystalline part was biaxially oriented by high stretching at room temperature, that is, (110) plane of the crystallite was preferentially oriented perpendicular to the surface plane of the film in the cross section perpendicular to the stretching axis. This phenomenon was elucidated from both the cohesive interactions between lattice planes and the compressive stress in the stretching process.
Effects of gamma radiation on some physical properties of polytetrafluoroethylene resin
Authors: Nishioka Atsuo , Matsumae Kazuyoshi , Watanabe Muneo , Tajima Moritaka , Owaki Masakazu 
Published: April 2003

AbstractEffects of gamma radiation on the properties, such as melt viscosity, elastic modulus above the melting point, creep fracture time above the melting point, density, and the degree of crystallinity by x‐ray diffraction, of polytetrafluoroethylene resin were studied. When exposed to the radiation from a Co60 gamma source, the melt viscosity falls rapidly with increasing radiation dose above 104 roentgens, and the rubber elasticity above the melting point decreases with increasing irradiation. Also, Zero Strength Time (a creep fracture time test) above the melting point decreases rapidly with irradiation above 103 roentgens; this behavior is attributable to the chain scission and the accompanying decrease in average molecular weight. Density was found to increase with radiation dose at doses higher than 104 roentgens; also, at 2θ = 18° peak in the X‐ray diffraction pattern, which is indicative of crystallinity, increases slightly in sharpness with irradiation.These facts suggest that gamma irradiation of this polymer produces chain scission and decreases the average molecular weight, and also causes partial crystallization followed by an increase in the density in the amorphous region. Therefore, crosslinking would probably be negligible in this polymer.
Photosensitive polymers. I. Cinnamate esters of poly(vinyl alcohol) and cellulose
Authors: Minsk L. M. , Smith J. G. , van Deusen W. P. , Wright J. F. 
Published: April 2003

AbstractCinnamic acid esters of poly(vinyl alcohol) and of cellulose are insolubilized by ultraviolet radiation. This response may be increased by the inclusion of simple organic compounds such as Crystal Violet carbinol and Michler's ketone. A method of measuring this response (in terms of a sensitivity value, S) based upon photographic sensitometry has been devised. Preliminary study indicates that an increase in S is accompanied by an increase in response to the longer wavelengths of light.
Radiation crosslinking of rubber. IV. Ultraviolet and infrared absorption spectra
Authors: Evans M. B. , Higgins G. M. C. , Turner D. T. 
Published: April 2003

AbstractWhen purified rubber is exposed in vacuo to high energy radiation, very few conjugated triene groups are formed relative to the number of molecules of hydrogen evolved. This indicates that less than 4% of the hydrogen is evolved from adjacent carbon atoms in the same molecule, a reaction which would have no immediate crosslinking potential. Rather more conjugated diene groups have been detected, but when these are compared together with triene groups relative to the yield of chemical crosslinks it can be calculated that less than 10% of the allylic radical precursors disproportionate. Infrared absorption spectra do not indicate the marked decrease in unsaturation reported by some previous workers. Slight changes in the infared spectra may indicate some cis‐trans isomerization. There is qualitative evidence for a small increase in vinylidene unsaturation.
Estimation of isotacticity in semicrystalline polymers
Authors: Nielsen Lawrence E. 
Published: April 2003

AbstractA new method is suggested for estimating the degree of isotacticity and the distribution of block lengths in semicrystalline polymers. The method is based upon the maximum attainable crystallinity and its dependence upon temperature. An alternate approach is based upon the dynamic shear modulus and its temperature dependence above the glass temperature.
Failure of foamed elastic materials
Authors: Gent A. N. , Thomas A. G. 
Published: April 2003

AbstractA theoretical treatment is given which predicts the tear strength of a foamed elastic material. The energy required to break a test‐piece in simple extension is also calculated, on the assumption that tensile failure occurs by catastrophic tearing from a small nick of a similar size to the largest pore present in the test‐piece. The behavior is given in terms of the strength of the matrix, the density of the foam, and the pore size. Measurements of the tear strength, tensile strength, and elongation at break are described for natural rubber foams prepared from latex. A wide range of density is covered (0.09–0.5) giving a variation in tear strength of 9 : 1 and in work‐to‐break of 24 : 1. Satisfactory agreement with theory is found in both cases, indicating that the basic concepts of the modes of failure are correct. It is concluded that uniformity of pore size is required for maximum strength, and a large average pore size for high tear resistance.