Showing papers by "Kent State University published in 1997"

Application of large pore MCM-41 molecular sieves to improve pore size analysis using nitrogen adsorption measurements

Abstract: MCM-41 siliceous molecular sieves were used to test the applicability of the Kelvin equation for nitrogen adsorption in cylindrical pores of the size from 2 to 65 nm It was shown that the Kelvin equation for the hemispherical meniscus, corrected for the statistical film thickness, is in quite good agreement with an experimental relation between the pore size and the capillary condensation pressure The agreement can be made quantitative in the pore size range from ca 2 to 65 nm, if a simple correction to the Kelvin equation is introduced The required statistical film thickness curve (t-curve) was calculated using nitrogen adsorption data for large pore MCM-41 samples and the obtained results were extrapolated using an adsorption isotherm for a macroporous silica gel Moreover, an accurate analytical representation of the t-curve was found Since both the corrected Kelvin equation for cylindrical pores and the t-curve have simple analytical forms, they can conveniently be used in a variety of methods

Adsorption Study of Surface and Structural Properties of MCM-41 Materials of Different Pore Sizes

Abstract: Nitrogen adsorption measurements were performed over a wide range of relative pressures (10-6−0.995) for a series of siliceous MCM-41 samples obtained using alkyltrimethylammonium surfactants with different chain length. Both high- and low-pressure adsorption data were analyzed. The pore size was shown to increase in a regular way with the chain length of the surfactant used. Moreover, a very good correlation between the pore size and the interplanar spacing of the MCM-41 samples was observed. Methods used to calculate the pore diameter were critically compared, and a new procedure to estimate the pore size of MCM-41 materials was proposed. This new procedure is based on geometrical considerations of the ratio of the pore volume to the pore wall volume for an infinite hexagonal array of cylindrical pores. Adsorption measurements showed that the amount adsorbed in the low-pressure region increases with a decrease in the pore size of the samples probably because of the enhancement of the gas−surface interac...

Precision Determination of the Neutron Spin Structure Function g1n

Abstract: We report on a precision measurement of the neutron spin structure function ${g}_{1}^{n}$ using deep inelastic scattering of polarized electrons by polarized ${}^{3}\mathrm{He}$. For the kinematic range $0.014lxl0.7$ and $1l{Q}^{2}l17(\mathrm{GeV}/c{)}^{2}$, we obtain $\ensuremath{\int}{0.014}^{0.7}{g}_{1}^{n}(x)dx\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}\ensuremath{-}0.036\ifmmode\pm\else\textpm\fi{}0.004(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.005(\mathrm{syst})$ at an average ${Q}^{2}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}5(\mathrm{GeV}/c{)}^{2}$. We find relatively large negative values for ${g}_{1}^{n}$ at low $x$. The results call into question the usual Regge theory method for extrapolating to $x\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0$ to find the full neutron integral $\ensuremath{\int}{1}^{}{g}_{1}^{n}(x)\mathrm{dx}$, needed for testing the quark-parton model and QCD sum rules.

Biased Assimilation, Attitude Polarization, and Affect in Reactions to Stereotype-Relevant Scientific Information

Abstract: Two studies examined (a) whether biased assimilation and attitude polarization occur in the processing of stereotype-relevant scientific information and (b) the role of affect in these processes. In Study 1, individuals high or low in prejudice toward homosexuals read two fictitious studies, one confirming and one disconfirming the stereotype of homosexuality. Study 2 replicated Study 1 using a sample including individuals with moderate attitudes about homosexuality. Evidence of biased assimilation was found. Participants perceived research consistent with their attitude about homosexuality as more convincing than research inconsistent with their attitude. Evidence of attitude polarization was also found but was restricted to measures of perceived attitude change. Finally, participants reported more negative affective reactions after attitude-inconsistent than attitude-consistent information, and evidence was found that these affective reactions mediated biased processing. Implications of the results for ...

Bridging Student Health Risks and Academic Achievement Through Comprehensive School Health Programs

Abstract: In the National Action Plan for Comprehensive School Health Education, representatives from over 40 health, education, and social service organizations viewed education and health as interdependent systems. Participants concluded that healthy children learn better, and they cautioned that no curriculum can compensate for deficiencies in student health status. While literature confirms the complexity of health issues confronting today's students, schools face enormous pressure to improve academic skills. Local school leaders and stakeholders often remain unconvinced that improving student health represents a means to achieving improved academic outcomes. A rich body of literature confirms a direct link between student health risk behavior and education outcomes, education behaviors, and student attitudes about education. This article summarizes relevant information concerning the health risk behavioral categories of intentional injuries; tobacco, alcohol, and other drugs; dietary, physical activity, and sexual risk behaviors.

Neural network applications in business: a review and analysis of the literature (1988-95)

Abstract: A survey of journal articles on neural network business applications published between 1988 and 1995 indicates that an increasing amount of neural network research is being conducted for a diverse range of business activities. The classification of literature by (1) year of publication, (2) application area, (3) problem domain, (4) decision process phase, (5) level of management, (6) level of task interdependence, (7) means of development, (8) corporate/academic interaction in development, (9) technology integration, (10) comparative study, (11) major contribution, and (12) journal provides some insights into the trends in neural networks research. The implications for neural networks developers/researchers and suggestions on future research areas are discussed.

The economic exposure of u.s. multinational firms

Abstract: In this paper we find that the exchange rate exposure of individual firms increases with the return horizon. Also, the cross-sectional differences in the magnitude of exposure of individual firms are significantly related to firm size but not to the relative portion of foreign sales to total sales. The empirical evidence is consistent with the hypothesis that hedging activities exhibit economies of scale, and, consequently, the magnitude of economic exposure is less for larger firms than for smaller firms.

Determinants of Target Responses to Sexual Harassment: A Conceptual Framework

Abstract: Although a significant number of researchers have investigated the diversity and commonality of targets' response strategies to sexual harassment (SH), research systematically exploring those responses has been limited. In this article we present a typology of target responses to SH: identify, through a careful analysis of the existing literature, the potential contextual and individual determinants of responses to SH; present a theoretical framework (supported by the whistle-blowing and stress/coping literatures) of the relationships among those determinants and how they collectively influence responses to SH: and identify a comprehensive set of propositions based on this conceptual framework. We also discuss implications for future research and the impact on organizational policies and procedures.

Where two roles intersect: spillover between parent care and employment.

Abstract: Spillover between the roles of parent care and employment was assessed in a sample of 105 employed adult daughter caregivers. This research examined how these 2 roles affect one another, both positively and negatively, and how such spillover was related to caregivers' psychological well-being. Path analyses indicated that negative spillover was an important mediating mechanism in the relationship between role stress and depression. In contrast, no evidence was found to suggest that positive spillover mediated the relationship between role satisfaction and positive affect. Findings extend prior research that has documented that caregiving and employment can interfere with one another by demonstrating that such spillover has implications for caregivers' emotional health.

Bistable polymer dispersed cholesteric liquid crystal displays

Abstract: Polymer/cholesteric liquid crystal dispersions are provided in which the liquid crystal phase separated from the polymer matrix to form droplets. The cholesteric liquid crystals were positive dielectric anisotropic. At a zero field condition, the liquid crystal in the droplets was bistable, that is, the liquid crystal can be in either the reflecting planar state or the scattering focal conic state. When the liquid crystal 101 was in the planar texture, the helical axis of the liquid crystal was more or less perpendicular to the cell surface; colored light 105 was Bragg reflected. When the liquid crystal 101 was in the focal conic texture, the helical axis was more or less parallel to the cell surface, incident light was scattering 106 in the forward direction.

Weight loss and wrestling training: effects on growth-related hormones

Abstract: Roemmich, James N., and Wayne E. Sinning. Weight loss and wrestling training: effects on growth-related hormones.J. Appl. Physiol. 82(6): 1760–1764, 1997.—Adolescent wrestlers (n = 9, 15.4 yr) and ...

The aging voice

Abstract: A number of studies have found that listeners are often able to differentiate the voices of young and old speakers accurately. Following an overview of structural and functional changes found in studies of aging larynges, this article examines current findings on maximum phonation duration, voice quality, vocal jitter/shimmer, spectral noise, and fundamental frequency. Aging can affect vocal pitch, loudness, and quality, but such effects are highly variable across the aging population. Therefore, a thorough voice and medical examination is needed to isolate voice problems caused by vocal abuse or pathology from those due to normal aging. Pushing exercises may be a viable treatment option for those with age-related voice problems.

Weight loss and wrestling training: effects on nutrition, growth, maturation, body composition, and strength

Abstract: Roemmich, James N., and Wayne E. Sinning. Weight loss and wrestling training: effects on nutrition, growth, maturation, body composition, and strength. J. Appl. Physiol. 82(6): 1751–1759, 1997.—Ado...

Ground-state spectrum of light-quark mesons

Abstract: A confining, Goldstone theorem preserving, separable ansatz for the ladder kernel of the two-body Bethe-Salpeter equation is constructed from phenomenologically efficacious $u$, $d$, and $s$ dressed-quark propagators. The simplicity of the approach is its merit. It provides a good description of the ground-state flavor-octet pseudoscalar, vector, and axial-vector meson spectrum facilitates an exploration of the relative importance of various components of the two-body Bethe-Salpeter amplitudes, showing that subleading Dirac components are quantitatively important in the flavor-octet pseudoscalar meson channels, and allows a scrutiny of the domain of applicability of ladder truncation studies. A color-antitriplet diquark spectrum is obtained. The shortcomings of separable Ans\"atze and the ladder kernel are highlighted.

How green‐claim strength and country disposition affect product evaluation and company image

Abstract: Green advertising is defined as the advertising that emphasizes the environmental friendliness of the product. Attributes such as degradability, recyclability, lower pollution et cetera are considered to be environmentally friendly. The research reported in this article addresses how the strength of a green claim, for example, the extent of pollution reduction claimed in an advertisement for a new automobile and the consumer's country disposition, that is, the consumer's attitude toward the country of origin of the automobile, interactively affected the product evaluation in terms of its greenness and company image in terms of its green consciousness. Product evaluation and company image were more favorable for consumers with highly positive country disposition than for consumers with less positive country disposition when the green claim was moderate in strength. However, when the green claim was extremely low or extremely high in strength, the reverse was true. Theoretical rationale for these findings draws upon several areas of research, for example, latitude of acceptance/rejection, assimilation/contrast effects, social cognition, country of origin, and Heider's balance theory. Managerial implications of the findings and future research directions are discussed. © 1997 John Wiley & Sons, Inc.

Effects of Instruction on Communication Apprehension and Communication Competence

Abstract: In this study, we assessed how classroom instruction might result in changes in students' communication competence (CC) and communication apprehension (CA). Students enrolled in a basic communication class completed the Personal Report of Communication Apprehension (PRCA) and the Self‐Perception of Communication Competence (SPCC) Scale at the beginning and end of a semester. Scores on the PRCA and SPCC negatively correlated with each other at Time 7 and Time 2. CC increased and CA decreased from Time 1 to Time 2. CC with strangers increased and CA in groups decreased from Time 1 to Time 2. High apprehensive and low competence students experienced greater changes in their respective PRCA and SPCC scores than did their counterparts. Students who completed the course and those who dropped out differed on dyadic SPCC and total PRCA. We discussed implications of the findings.

Polymer stabilized black-white cholesteric reflective display

Abstract: A new liquid crystalline light modulating cell and material are characterized by liquid crystalline light modulating material of liquid crystal and polymer, the liquid crystal being a chiral nematic liquid crystal having positive dielectric anisotropy and including chiral material in an amount effective to form focal conic and twisted planar textures, the polymer being distributed in phase separated domains in the liquid crystal cell in an amount that stabilizes the focal conic and twisted planar textures in the absence of a field and permits the liquid crystal to change textures upon the application of a field. In one embodiment, the material is light scattering in a field-OFF condition and optically clear in a field-ON condition, while in another embodiment, the material is optically clear in a field-OFF condition and light scattering in a field-ON condition. In still another embodiment, the material exhibits stability at zero field in a colored, light reflecting state, a light scattering state and multiple stable reflecting state therebetween, as well as being optically clear in the presence of a field. This embodiment allows for a display with a substantially white background with substantially black characters much like a printed page. In yet another embodiment, the application of mechanical force to the cell changes the material from an optically clear state to a light reflecting state.

Wave-ray multigrid method for standing wave equations.

Abstract: Multigrid methods are known for their high efficiency in the solution of definite elliptic problems. However, difficulties that appear in highly indefinite problems, such as standing wave equations, cause a total loss of efficiency in the standard multigrid solver. The aim of this paper is to isolate these difficulties, analyze them, suggest how to deal with them, and then test the suggestions with numerical experiments. The modified multigrid methods introduced here exhibit the same high convergence rates as usually obtained for definite elliptic problems, for nearly the same cost. They also yield a very efficient treatment of the radiation boundary conditions.

Role of Neural Cell Adhesion Molecule and Polysialic Acid in Mouse Circadian Clock Function

Abstract: The suprachiasmatic nuclei (SCN) express the highly polysialylated form of the neural cell adhesion molecule (NCAM) that has been proposed to promote plasticity in the adult brain. To investigate a role for NCAM in SCN circadian clock function, we examined the daily locomotor rhythm of mice homozygous for a mutation, Ncam tm1Cwr, which results in deletion of the NCAM-180 isoform that in brain carries polysialic acid (PSA). Mutant mice entrained well to a 12 hr light/dark cycle but exhibited a significantly shortened free-running period and longer activity duration under constant darkness (DD) than did wild-type mice. By the third week of DD treatment, circadian rhythmicity in the mutant was abolished. Immunocytochemical analyses of the mutant SCN revealed an abnormal number and distribution of vasoactive intestinal polypeptide-producing neurons, suggesting a developmental effect of the mutant phenotype; however, a direct physiological effect of the mutation on clock function was indicated by the fact that removal of PSA from adult wild-type SCN by microinjection of endoneuraminidase shortened the free-running period to a similar extent as in the mutant. Together, these data indicate critical roles for NCAM and PSA in the development and physiology of the mammalian SCN circadian clock.

Cortical bone distribution in the femoral neck of hominoids: Implications for the locomotion of Australopithecus afarensis

Abstract: Contiguous high resolution computed tomography images were obtained at a 1.5 mm slice thickness perpendicular to the neck axis from the base of the femoral head to the trochanteric line in a sample of 10 specimens each of Homo sapiens, Pan troglodytes, and Gorilla gorilla, plus five specimens of Pan paniscus. Superior, inferior, anterior, and posterior cortical thicknesses were automatically measured directly from these digital images. Throughout the femoral neck H. sapiens displays thin superior cortical bone and inferior cortical bone that thickens distally. In marked contrast, cortical bone in the femoral neck of African apes is more uniformly thick in all directions, with even greater thickening of the superior cortical bone distally. Because the femoral neck acts as a cantilevered beam, its anchorage at the neck-shaft junction is subjected to the highest bending stresses and is the most biomechanically relevant region to inspect for response to strain. As evinced by A.L. 128-1, A.L. 211-1 and MAK-VP-1/1, Australopithecus afarensis is indistinguishable from H. sapiens, but markedly different from African apes in cortical bone distribution at the femoral neck-shaft junction. Cortical distribution in the African ape indicates much greater variation in loading conditions consistent with their more varied locomotor repertoire. Cortical distribution in hominids is a response to the more stereotypic loading pattern imposed by habitual bipedality, and thin superior cortex in A. afarensis confirms the absence of a significant arboreal component in its locomotor repertoire.

Evaluating the relation of vocal accommodation in conversation partners' fundamental frequencies to perceptions of communication quality

Abstract: Previous acoustic analysis of fundamental frequencies from interview partners' voices revealed mutual accommodation of voice frequency and amplitude These findings also showed partners' accommodation was associated with such attributes as social status However, previous studies did not assess the function of partners' voice accommodation in extending general communication quality The present study employs an experimental protocol wherein the fundamental frequency is included in some conversations and filtered from others to show, first, that partners do actively accommodate the fundamental frequency of their voices, and, second, that elimination of the fundamental frequency from conversation partners' voices profoundly alters perceived positive evaluations by judges overhearing the conversation This experiment specifies an important auxiliary role for the fundamental frequency in nonverbal communication

The Structure of Health Status Among Hispanic, African American, and White Older Adults

Abstract: Activities of daily living (ADLs), instrumental ADLs, and disability markers have traditionally been the most common indicators of functional status. The study on Asset and Health Dynamics Among the Oldest Old (AHEAD) is used to replicate a five-dimensional measurement model composed of these observable indicators among the older adult self-respondents. The items available to measure upper body disability were found wanting, but the lower body disability, and the basic, household, and advanced ADL constructs were confirmed. Analyses of the measurement model separately among subgroups of women, men, Hispanics, Mexican Americans, African Americans, and Whites found no meaningful differences. Two structural models linking the lower body disability, and the basic, household, and advanced ADL constructs to perceived health and depression were also replicated among the older adult self-respondents, as well as separately among African Americans and among Whites. These models reaffirmed the dominant role of lower body disability on the everyday activities of older adults, and on their perceived health and depression.

Stress of parent care: positive and negative effects of women's other roles.

Abstract: The present study focused on 296 women who were primary caregivers to an ill or disabled parent or parent-in-law and who simultaneously occupied 3 other roles as mother, wife, and employee. All women lived in separate households from their impaired parent and had at least 1 child 25 years of age or younger living at home. It was predicted that stress in the roles of mother, wife, and employee would exacerbate the effects of stress in the parent care role on psychological well-being (depression and life satisfaction) and that rewards in these 3 additional roles would buffer the effects of parent care stress. For all 3 additional roles, findings supported the stress exacerbation hypothesis. In contrast, only the employee role supported the stress-buffering hypothesis. These findings underscore the complex relationships that often exist between women's multiple role experiences and their psychological well-being.

Switchable Diffractive Cholesteric Gratings

Abstract: Electrically switchable diffractive gratings based on cholesteric liquid crystals are suggested. An electric field switches the cholesteric cell between three states: two with a uniform in-plane director and one with a periodic in-plane director modulation. The modulated state produces a Raman–Nath diffractive effect. Characteristic time of switching is of the order of 10 ms. Diffractive properties depend on the polarization of the incident beam and the direction of surface orientation.

Adsorption and Thermogravimetric Studies of Silica-Based Amide Bonded Phases

Abstract: Moreover, adsorption energy distribution functions were calculated from submonolayer adsorption data using the regularization method. It was estimated that about 40% of the available surface silanols were converted to amine groups and about 60% of amines were converted to amides. It was shown that although the chemical modification of the surface does not significantly alter the porous properties of the starting silica, it significantly affects the interaction of nitrogen probe molecules with the surface. Moreover, it was demonstrated that nitrogen adsorption is quite sensitive to the presence or absence of various functional groups on the silica surface and that the information obtained from the adsorption measurements can be utilized for the characterization of silica-based materials used in chromatographic applications.