Showing papers by "University of Delaware published in 1994"
Tohoku University1, University of Zurich2, Lawrence Berkeley National Laboratory3, Stanford University4, College of William & Mary5, University of Urbino6, CERN7, Budker Institute of Nuclear Physics8, University of California, Irvine9, Cornell University10, Argonne National Laboratory11, ETH Zurich12, Tata Institute of Fundamental Research13, Hillsdale College14, Spanish National Research Council15, Ohio State University16, University of Notre Dame17, Kent State University18, University of California, San Diego19, University of California, Berkeley20, University of Minnesota21, University of Alabama22, University of Helsinki23, Los Alamos National Laboratory24, California Institute of Technology25, George Washington University26, Syracuse University27, Lawrence Livermore National Laboratory28, Oklahoma State University–Stillwater29, University of Washington30, Max Planck Society31, Boston University32, University of California, Los Angeles33, Royal Holloway, University of London34, Université Paris-Saclay35, University of Pennsylvania36, University of Illinois at Urbana–Champaign37, University of Bristol38, University of Tokyo39, University of Delaware40, Carnegie Mellon University41, University of California, Santa Cruz42, Karlsruhe Institute of Technology43, Heidelberg University44, Florida State University45, University of Mainz46, University of Edinburgh47, Brookhaven National Laboratory48, Durham University49, University of Lausanne50, Massachusetts Institute of Technology51, University of Southampton52, Nagoya University53, University of Oxford54, Northwestern University55, University of British Columbia56, Columbia University57, Lund University58, University of Sheffield59, University of California, Santa Barbara60, Iowa State University61, University of Alberta62, University of Cambridge63
TL;DR: This biennial Review summarizes much of Particle Physics using data from previous editions, plus 2205 new measurements from 667 papers, and features expanded coverage of CP violation in B mesons and of neutrino oscillations.
Abstract: This biennial Review summarizes much of Particle Physics. Using data from previous editions, plus 2205 new measurements from 667 papers, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We also summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as the Standard Model, particle detectors, probability, and statistics. This edition features expanded coverage of CP violation in B mesons and of neutrino oscillations. For the first time we cover searches for evidence of extra dimensions (both in the particle listings and in a new review). Another new review is on Grand Unified Theories. A booklet is available containing the Summary Tables and abbreviated versions of some of the other sections of this full Review. All tables, listings, and reviews (and errata) are also available on the Particle Data Group website: http://pdg.lbl.gov.
5,143 citations
TL;DR: The authors collected data on nine attributes of seventy-four American manufacturing MNCs and found a linear combination of five variables with a reliability coefficient of.79 as a measure of the degree of internationalization of a firm.
Abstract: In spite of both positivistic and instrumental research, the reliability of measuring the degree of internationalization of a firm remains speculative. We collected data on nine attributes of seventy-four American manufacturing MNCs. Alpha, factor, and frequency analyses revealed a linear combination of five variables with a reliability coefficient of .79 as a measure of the degree of internationalization of a firm. We discuss the statistical and conceptual properties of the scale and their implications for content and construct validity.
1,394 citations
TL;DR: In this article, a review of microfiltration is presented, focusing on the formation of cakes, the behavior of suspension flows and particle transport in simple geometry ducts, and the formation and behavior of fouling layers including those resulting from macromolecules, colloids and particles.
1,317 citations
TL;DR: This article investigated the effects of corrective procedures on language learning and found that corrective moves by teachers or other caretakers are ineffective in correcting learner errors in a learner's own right.
Abstract: enties, with the ground breaking publications of Pit Corder, Burt and Kiparsky, George, and Richards (14), one of the central themes of second language research has been the study of learner errors as a reflection of hypothesis testing on the part of second language learners (8; 15; 20; 23;)1 Eventually, the attention of those working on learner errors has moved away from the analysis of errors in their own right as indications of hypothesis testing and interlanguage development to concern with questions relating to the potential effects of corrective procedures on language learning The fundamental question is: does error correction lead to learning, or are corrective moves by teachers or other caretakers ineffective? In addition, some corollary questions have also been addressed, including how and when errors should be corrected (7: p 135) Research aimed at answering these questions has been carried out in either an ethnographic or an experimental framework2 Those working within the ethnographic approach have conducted careful observational studies of corrective behaviors both in the classroom and natu-
1,070 citations
TL;DR: In this article, new evidence is presented that supports the Darwinian hypothesis of the innateness and universality of the facial expressions of a limited set of emotions and the efficacy of the most commonly used method of testing it.
Abstract: The idea of innate and universal facial expressions that have links with human emotions was given the status of scientific hypothesis by Darwin (1872/1965). Substantial evidence, old and new, supports his hypothesis. Much of the evidence is independent of language, but Russell's (1994) criticisms of the hypothesis focus on language-dependent data. In this article, it is argued that Russell's critique was off target in that his arguments relate only to a hypothesis of the universality of semantic attributions and overstated in that he used questionable logic in designing studies to support his claims. It is also argued that Russell misinterpreted the relation between the universality hypothesis and differential emotions theory. Finally, new evidence is presented that supports the Darwinian hypothesis of the innateness and universality of the facial expressions of a limited set of emotions and the efficacy of the most commonly used method of testing it.
789 citations
TL;DR: The authors focus on brand familiarity's role in advertising interference and find that consumers often encounter ads for familiar brands, whereas previous interference studies have used ads for low-familiarity brands.
Abstract: Although consumers often encounter ads for familiar brands, previous advertising interference studies have used ads for low-familiarity brands. The authors focus on brand familiarity's role in incr...
724 citations
TL;DR: In this article, a calibrated chemical extraction scheme was developed for partitioning reactive Fe(III) minerals in the solid phase of marine sediments, and the following chemical extractants were used: ascorbate, oxalate, dithionite, and HC1 (0.5 M).
620 citations
TL;DR: This work presents a new class of inflationary models based on realistic supersymmetric grand unified theories which do not have the usual `fine tuning' problems and is found to be proportional to the GUT (Planck) scale.
Abstract: We explore constraints on the spectral index $n$ of density fluctuations and the neutrino energy density fraction ${\ensuremath{\Omega}}_{\ensuremath{
u}}$ from observations of large scale structure. The best fits imply $n\ensuremath{\approx}1$ and ${\ensuremath{\Omega}}_{\ensuremath{
u}}\ensuremath{\approx}0.1\ensuremath{-}0.3$, for Hubble constants 40-60 km ${\mathrm{s}}^{\ensuremath{-}1}$ ${\mathrm{Mpc}}^{\ensuremath{-}1}$. We present a new class of inflationary models based on realistic supersymmetric grand unified theories (GUTs) which do not have the usual "fine tuning" problems. The amplitude of primordial density fluctuations is found to be $\ensuremath{\propto}{(\frac{{M}_{X}}{{M}_{P}})}^{2}$, where ${M}_{X}$ (${M}_{P}$) denote the GUT (Planck) scale. The spectral index $n=0.98$, in excellent agreement with the observations.
579 citations
TL;DR: In poor, inner-city communities young smokers of crack cocaine, particularly women who have sex in exchange for money or drugs, are at high risk for HIV infection.
Abstract: Background and Methods The smoking of “crack” cocaine is thought to be associated with high-risk sexual practices that accelerate the spread of infection with the human immunodeficiency virus (HIV). We studied 2323 young adults, 18 to 29 years of age, who smoked crack regularly or who had never smoked crack. The study participants, recruited from the streets of inner-city neighborhoods in New York, Miami, and San Francisco, were interviewed and tested for HIV. This report presents the findings for the 1967 participants (85 percent) who had never injected drugs. Results Of the 1137 crack smokers, 15.7 percent were positive for HIV antibody, as compared with 5.2 percent of the 830 nonsmokers (prevalence ratio adjusted for the city, 2.4; 99 percent confidence interval, 1.7 to 3.6). The prevalence of HIV was highest among the crack-smoking women in New York (29.6 percent) and Miami (23.0 percent). In these two cities, of the 283 women who had sex in exchange for money or drugs, 30.4 percent were infected with...
575 citations
TL;DR: A set of six lexical principles for making object label learning a manageable task are presented and critically evaluated, with the effect of reducing the amount of information that language-learning children must consider for what a new word might mean.
Abstract: Universally, object names make up the largest proportion of any word type found in children's early lexicons. Here we present and critically evaluate a set of six lexical principles (some previously proposed and some new) for making object label learning a manageable task. Overall, the principles have the effect of reducing the amount of information that language-learning children must consider for what a new word might mean. These principles are constructed by children in a two-tiered developmental sequence, as a function of their sensitivity to linguistic input, contextual information, and social-interactional cues. Thus, the process of lexical acquisition changes as a result of the particular principles a given child has at his or her disposal. For children who have only the principles of the first tier (reference, extendibility, and object scope), word learning has a deliberate and laborious look. The principles of the second tier (categorical scope, novel name-nameless category' or N3C, and conventionality) enable the child to acquire many new labels rapidly. The present unified account is argued to have a number of advantages over treating such principles separately and non-developmentally. Further, the explicit recognition that the acquisition and operation of these principles is influenced by the child's interpretation of both linguistic and non-linguistic input is seen as an advance.
486 citations
TL;DR: It is argued here that high uptake of dissolved organic carbon, which has been questioned, is necessary to balance the measured uptake of dissolve inorganic nitrogen (DIN) in seawater culture experiments, because this DIN uptake exceeds bacterial biomass production.
Abstract: It is now well known that heterotrophic bacteria account for a large portion of total uptake of both phosphate (60% median) and ammonium (30% median) in freshwaters and marine environments. Less clear are the factors controlling relative uptake by bacteria, and the consequences of this uptake on the plankton community and biogeochemical processes, e.g., new production. Some of the variation in reported inorganic nutrient uptake by bacteria is undoubtedly due to methodological problems, but even so, uptake would be expected to vary because of variation in several parameters, perhaps the most interesting being dissolved organic matter. Uptake of ammonium by bacteria is very low whereas uptake of dissolved free amino acids (DFAA) is high in eutrophic estuaries (the Delaware Bay and Chesapeake Bay). The concentrations and turnover of DFAA are insufficient, however, in oligotrophic oceans where bacteria turn to ammonium and nitrate, although the latter only as a last resort. I argue here that high uptake of dissolved organic carbon, which has been questioned, is necessary to balance the measured uptake of dissolved inorganic nitrogen (DIN) in seawater culture experiments. What is problematic is that this DIN uptake exceeds bacterial biomass production. One possibility is that bacteria excrete dissolved organic nitrogen (DON). A recent study offers some support for this hypothesis. Lysis by viruses would also release DON.
TL;DR: This article examined whether the manipulation of the perception of partner's honesty and intelligence interacts with the observer's own social value orientation to influence the latter's expectations regarding partner cooperation and own cooperation in a social dilemma.
Abstract: This research evaluates the might vs. morality effect (Liebrand, Jansen, Rijken, & Suhre, 1986) by examining whether the manipulation of the perception of partner's honesty and intelligence interacts with the observer's own social value orientation to influence the latter's expectations regarding partner cooperation and own cooperation in a social dilemma. Results reveal that greater cooperation was expected from an honest partner than from a dishonest partner and that this effect was stronger for prosocial Ss than for individualists and competitors. Conversely, individualists and competitors expected greater cooperation from an unintelligent partner than from an intelligent partner, whereas prosocial Ss did not expect differences between these partners. Similar findings were obtained for own cooperation, although social value orientations did not interact with partner intelligence. Considerable research has been focused on how individuals form, maintain, and organize personality impressions, revealing that people readily form impressions of others, that such impressions are fairly stable, and that such impressions frequently are organized along dimensions of social meaning, such as honesty and intelligence (e.g., for theoretical analyses, see Reeder & Brewer, 1979; Rosenberg SSkowronski
TL;DR: The most common poultry wastes are poultry manure or poultry litter, dissolved air flotation (DAF) sludge originating from poultry processing plants, and composts produced from hatchery wastes and dead birds.
Abstract: Publisher Summary This chapter focuses on the development of management programs that meet the increasing demand for poultry products, while minimizing the environmental effects of poultry wastes on soils, crops, surface waters, and groundwaters. A description of the types and compositions of poultry wastes, and a review of recent research addressing the agricultural and environmental aspects of poultry waste management are discussed in the chapter. Effective environmental management of any poultry waste begins with an understanding of its composition and the physical, chemical, and microbiological reactions that control the fate of potential pollutants in the waste following land application. The three most common poultry wastes are poultry manure or poultry litter, dissolved air flotation (DAF) sludge originating from poultry processing plants, and composts produced from hatchery wastes and dead birds. The major poultry production operations include broiler chickens, turkeys, and eggs. Two types of confinement housing are commonly used for poultry operations: caged pit systems and floor/litter systems. Land application of animal waste is an important management practice to recycle nutrients, to improve or maintain soil fertility, and to improve soil biological and physical properties. The components of an effective waste management program for the agricultural use of organic wastes include site selection; production and collection; storage, handling, and treatment; transfer and application; and utilization.
TL;DR: An alternative approach to diagnosing iron-limitation uses molecules whose abundance increases in response to iron- Limitation, including cell surface iron-transport proteins, and the electron transfer protein flavodoxin which replaces the Fe-S protein ferredoxin in many Fe-deficient algae and cyanobacteria.
Abstract: Iron supply has been suggested to influence phytoplankton biomass, growth rate and species composition, as well as primary productivity in both high and low NO3− surface waters. Recent investigations in the equatorial Pacific suggest that no single factor regulates primary productivity. Rather, an interplay of bottom-up (i.e., ecophysiological) and top-down (i.e., ecological) factors appear to control species composition and growth rates. One goal of biological oceanography is to isolate the effects of single factors from this multiplicity of interactions, and to identify the factors with a disproportionate impact. Unfortunately, our tools, with several notable exceptions, have been largely inadequate to the task. In particular, the standard technique of nutrient addition bioassays cannot be undertaken without introducing artifacts. These so-called ‘bottle effects’ include reducing turbulence, isolating the enclosed sample from nutrient resupply and grazing, trapping the isolated sample at a fixed position within the water column and thus removing it from vertical movement through a light gradient, and exposing the sample to potentially stimulatory or inhibitory substances on the enclosure walls. The problem faced by all users of enrichment experiments is to separate the effects of controlled nutrient additions from uncontrolled changes in other environmental and ecological factors. To overcome these limitations, oceanographers have sought physiological or molecular indices to diagnose nutrient limitation in natural samples. These indices are often based on reductions in the abundance of photosynthetic and other catalysts, or on changes in the efficiency of these catalysts. Reductions in photosynthetic efficiency often accompany nutrient limitation either because of accumulation of damage, or impairment of the ability to synthesize fully functional macromolecular assemblages. Many catalysts involved in electron transfer and reductive biosyntheses contain iron, and the abundances of most of these catalysts decline under iron-limited conditions. Reductions of ferredoxin or cytochrome f content, nitrate assimilation rates, and dinitrogen fixation rates are amongst the diagnostics that have been used to infer iron limitation in some marine systems. An alternative approach to diagnosing iron-limitation uses molecules whose abundance increases in response to iron-limitation. These include cell surface iron-transport proteins, and the electron transfer protein flavodoxin which replaces the Fe-S protein ferredoxin in many Fe-deficient algae and cyanobacteria.
TL;DR: In this paper, a survey study involving 1,357 students attending a multi-cultural high school explored how the features identified by the contact hypothesis reduce intergroup bias, in part because they alter cognitive representations of the student body from different groups to a more inclusive ingroup.
Abstract: This survey study involving 1,357 students attending a multi-cultural high school explored how thefeatures identified by the contact hypothesis reduce intergroup bias. Specifically, the study examined predictions derived from the common ingroup identity model that equal status, cooperative interdependence, interaction and egalitarian norms reduce bias, in part, because they alter cognitive representations of the student body from different groups to a more inclusive ingroup. The survey measured students'impressions of thefeatures of contact at school, their representations of the student body (e.g., as one group or different groups), and bias in their affective reactions and overall attitudinal favorability toward groups at school. In general, reductions in bias were predicted by stronger common ingroup representations, weaker representations of two groups, and ethnic/racial identities that included a superordinate American identity. Furthermore, as predicted, cognitive representations (e.g., as one group...
TL;DR: In this paper, the mean flow and turbulence in a wave flume for a spilling breaker and a plunging breaker were studied, and the results indicated that there are fundamental differences in the dynamics of turbulence between spilling and plunging breakers, which can be related to the processes of wave breaking and turbulence production.
TL;DR: The physical basis and some applications of an efficient event generator designed for Monte Carlo simulations of atmospheric cascades at ultrahigh energies are described.
Abstract: We describe the physical basis and some applications of an efficient event generator designed for Monte Carlo simulations of atmospheric cascades at ultrahigh energies. The event generator (sibyll) incorporates many features of the Lund programs, but emphasizes the fragmentation region and the production of minijets. A consistent treatment of hadron-hadron and hadron-nucleus interactions is emphasized. Examples of applications are the calculation of coincident muons observed in deep underground detectors and the simulation of the longitudinal development of air shower components in the atmosphere.
TL;DR: Investigations with case managers with serious psychopathological disorders found that insecure case managers attended more to dependency needs and intervened in greater depth with preoccupied clients than they did with dismissing clients.
Abstract: The relationship between case managers' attachment organization and interventions used with clients who have serious psychopathological disorders was examined. Adult Attachment Interviews were administered to 27 clients and their 18 case managers. Interviews were coded by means of Kobak's Q-set, which yields scores for secure-insecure and preoccupied-dismissing attachment strategies. Case managers were interviewed during each of 5 months regarding their most recent interventions; interventions were coded for depth of intervention and attention to dependency needs. Compared with secure case managers, insecure case managers attended more to dependency needs and intervened in greater depth with preoccupied clients than they did with dismissing clients. Case managers who were more preoccupied intervened with their clients in greater depth than did case managers who were more dismissing.
TL;DR: A burst-superimposition technique was used to assess the strength of the quadriceps femoris muscle in three groups of patients who had had a torn anterior cruciate ligament of the knee and had a reconstruction of the ligament one to six months after the injury.
Abstract: A burst-superimposition technique was used to assess the strength of the quadriceps femoris muscle in three groups of patients. Group 1 comprised twenty patients who had had a torn anterior cruciate ligament of the knee and had a reconstruction of the ligament one to six months after the injury. Group 2 comprised twelve patients who had had a torn anterior cruciate ligament for an average of three months (a subacute tear). Group 3 comprised eight patients who had had a torn anterior cruciate ligament for an average of two years (a chronic tear). The patients in Groups 2 and 3 had not had an operation for the torn ligament. The patients in Groups 1 and 3 had no evidence of failure of activation of the involved quadriceps, but nine of the twelve patients in Group 2 had reflex inhibition of contraction of the muscle.
TL;DR: In this paper, the authors present analytical tip region solutions for fracture width and pressure when a power law fluid drives a plane strain fracture in an impermeable linear elastic solid, where the tip region stress is dominated by a singularity which is particular to the hydraulic fracturing problem.
Abstract: We present analytical tip region solutions for fracture width and pressure when a power law fluid drives a plane strain fracture in an impermeable linear elastic solid. Our main result is an intermediate asymptotic solution in which the tip region stress is dominated by a singularity which is particular to the hydraulic fracturing problem. Moreover this singularity is weaker than the inverse square root singularity of linear elastic fracture mechanics. We also show how the solution for a semi-infinite crack may be exploited to obtain a useful approximation for the finite case.
TL;DR: A single-crystal neutron diffraction study of the incommensurate magnetic ordering that occurs in La[sub 2]NiO[sub 4.125] below 110 K indicates that the holes, induced by the excess oxygen, order in domain walls that form antiphase boundaries between antiferromagnetic domains.
Abstract: We report a single-crystal neutron diffraction study of the incommensurate magnetic ordering that occurs in ${\mathrm{La}}_{2}$Ni${\mathrm{O}}_{4.125}$ below 110 K. Besides the magnetic first and third harmonic Bragg peaks, we have also observed second harmonic peaks associated with charge ordering. The magnitude of the incommensurate splitting, $\ensuremath{\epsilon}$, is strongly temperaure dependent. Lock-in behavior indicates that $\ensuremath{\epsilon}$ tends to rational fractions, while regions of continuous variation suggest a devil's staircase. Analysis of these features indicates that the holes, induced by the excess oxygen, order in domain walls that form antiphase boundaries between antiferromagnetic domains.
TL;DR: In this paper, an integrated system for the computer generation of kinetic models is described, where the main input is the structure of the reactants, the reaction rules, and the parameters of a structure/property kinetics correlation The algorithm transforms this information into reactant/product relationships, i.e., the reaction network, species properties, rate constants, and FORTRAN code corresponding to the governing species' balance equations.
Abstract: The development of an integrated system for the computer generation of kinetic models is described Required input is the structure of the reactants, the reaction rules, and the parameters of a structure/property kinetics correlation The algorithm transforms this information into reactant/product relationships, ie, the reaction network, species properties, rate constants, and the FORTRAN code corresponding to the governing species' balance equations, and offers a solution capability Graph theory is exploited to represent the constituent atoms of a molecule to allow determination of species' uniqueness, implement chemical reactions, and identify reaction products Special attention was devoted to improved algorithm efficiencies, the handling of ring systems, and on-the-fly'' quantum chemical calculations This general approach is described in using ethane and cyclohexane pyrolysis case studies The increase in the number of equations and number of components for ethane pyrolysis was exponential with the carbon number of allowed species
TL;DR: Use of high-intensity electrical stimulation to enhance recovery of quadriceps femoris muscle force production in patients following anterior cruciate ligament reconstruction is supported and the use of low-intensity or battery-powered stimulators are not supported.
Abstract: Background and Purpose. Electrical stimulation has been shown to be effective in aiding the recovery of quadriceps femoris muscle force production after anterior cruciate ligament reconstruction. The actual dosage of stimulation (training intensity) has not been well described. The purpose of this investigation was to establish a dose-response curve for electrical stimulation regimens designed to improve quadriceps femoris muscle recovery in patients after anterior cruciate ligament reconstruction. Subjects and Methods. We analyzed data from a subsample (n=52) of patients receiving electrical stimulation (N=110) who were involved in a large, multicenter randomized clinical trial investigating treatment strategies designed to enhance quadriceps femoris muscle recovery. Fifty-two subjects (40 male, 12 female), with an age range of 15 to 43 years (X=25, SD=7), participated in 4 weeks of quadriceps femoris muscle training using either portable, battery-powered home stimulators or console stimulators designed for clinical use. Training intensities were monitored by logging the electrically elicited knee extension torque and expressing this torque as a percentage of the uninvolved quadriceps femoris muscles' maximal voluntary contraction force. After the 4 weeks of training, isometric muscle torque was assessed and a dose-response curve was generated. The relationship between training intensity and quadriceps femoris muscle torque was assessed with Pearson Product-Moment Correlation Coefficients. Results. A significant, linear correlation was found between training intensity and quadriceps femoris muscle torque. Subjects training with console, clinical generators trained at higher intensities than those training with portable, battery-operated generators; such training resulted in higher quadriceps femoris muscle torque. Conclusion and Discussion. These results support the use of high-intensity electrical stimulation and do not support the use of low-intensity or battery-powered stimulators when the goal is recovery of quadriceps femoris muscle force production in the early phases of rehabilitation after anterior cruciate ligament surgery.
TL;DR: The result presented in this paper is that all four of the formalisms under consideration generate exactly the same class of string languages.
Abstract: There is currently considerable interest among computational linguists in grammatical formalisms with highly restricted generative power. This paper concerns the relationship between the class of string languages generated by several such formalisms, namely, combinatory categorial grammars, head grammars, linear indexed grammars, and tree adjoining grammars. Each of these formalisms is known to generate a larger class of languages than context-free grammars. The four formalisms under consideration were developed independently and appear superficially to be quite different from one another. The result presented in this paper is that all four of the formalisms under consideration generate exactly the same class of string languages.
TL;DR: The results clearly demonstrate that the effectiveness of selective protein filtration can be dramatically altered by appropriately controlling electrostatic interactions through changes in pH and/or ionic strength.
Abstract: Although protein fractionation by selective membrane filtration has numerous potential applications in both the downstream processing of fermentation broths and the purification of plasma proteins, the selectivity for proteins with only moderately different molecular weights has generally been quite poor. We have obtained experimental data for the transport of bovine serum albumin (BSA) and immunoglobulins (IgG) through 100,000 and 300,000 molecular weight cutoff polyethersulfone membranes in a stirred ultrafiltration device at different solution pH and ionic strength. The selectivity was a complex function of the flux due to the simultaneous convective and diffusive solute transport through the membrane and the bulk mass transfer limitations in the stirred cell. Under phsioligical conditions (pH 7.0 and 0.15 M NaCI) the maximum selectivity for the BSA-IgG separation was only about 2.0 due primarily to the effects of protein adsorption. In contrast, BSA-IgG selectivities as high as 50 were obtained with the same membranes when the protein solution was at pH 4.8 and 0.0015 M NaCl. This enhanced selectivity was a direct result of the electrosatatic contributions to both bulk and membrane transport. The membrane selectivity could actually be reversed, with higher passage of the larger IgG molecules, by using a 300,000 molecular weight cutoff membrane at pH 7.4 and an ionic strength of 0.0015 M NaCl. These results clearly demonstrate that the effectiveness of selective protein filtration can be dramatically altered by appropriately controlling electrostatic interactions through changes in pH and/or ionic strength. (c) 1994 John Wiley & Sons, Inc.
TL;DR: A number of analytical methods have been developed for approximating the sulfur functional group compositions of coals as discussed by the authors, and some of these are destructive tests depending on pyrolysis or catalytic reduction to H 2 S or oxidation to SO 2.
TL;DR: In this paper, a partial differential equation that describes the size and composition distribution of atmospheric particles is stated, and numerical methods are developed to solve the equation in conjunction with an Eulerian gas-phase model.
TL;DR: Giddens' structurationist metatheory as mentioned in this paper is a means to honour both calls for a broader, more unified perspective and demands for metatheoretical and theoretical pluralism, without resorting to the self-stultifying incommensurability thesis.
Abstract: Although some organizational scholars invoke the alleged incommensurability of metatheoretical paradigms in order to legitimize a plurality of approaches to the field, others have called for cross- or multi-paradigm inquiry into organizations while yet maintaining the essential incommensurability of paradigms. As long as the incommensurability thesis itself is maintained, however, calls for cross- or multi-paradigm inquiry are compromised, and legitimate goals of theoretical and metatheoretical diversity are poorly served. The problem is not with such calls for broader but still diverse perspectives, but with the incommensurability thesis to which they infelicitously are tied. Giddens' structurationist metatheory pro vides a means to honour both calls for a broader, more unified perspective and demands for metatheoretical and theoretical pluralism, without resorting to the self-stultifying incommensurability thesis. A structurational analysis enables us to give up the idea of impermeable and imperialistic...
TL;DR: In this article, the authors propose a method for reconstructing blocky conductivity profiles in electrical impedance tomography, which is based on selecting a conductivity distribution that has the least total variation from all conductivities that are consistent with the measured data.
Abstract: We propose an idea for reconstructing 'blocky' conductivity profiles in electrical impedance tomography. By 'blocky' profiles, we mean functions that are piecewise constant, and hence have sharply defined edges. The method is based on selecting a conductivity distribution that has the least total variation from all conductivities that are consistent with the measured data. We provide some motivation for this approach and formulate a computationally feasible problem for the linearized version of the impedance tomography problem. A simple gradient descent-type minimization algorithm, closely related to recent work on noise and blur removal in image processing via non-linear diffusion is described. The potential of the method is demonstrated in several numerical experiments.
TL;DR: The meaning of manhood has been treated as largely unidimensional and universal-man as economic provider and as head of the family as discussed by the authors, and what Black men are and what they should be is measured against the status and privilege of White males.
Abstract: The adequacy of male role performance has dominated research on masculinity and manhood among Black men (Franklin, 1984; Frazier, 1939; Hare, 1971; Liebow, 1967; Moynihan, 1965; Pleck, 1981; Staples, 1982). Specifically, men's roles as economic providers or as patriarchs have been central to this work. Black males' struggles with manhood, whether a byproduct of structural barriers, cultural pathology, or both, are implicated as a contributor to the rates of female-headed households, never-married childbearing, and divorce in Black communities (Liebow, 1967; Staples, 1982; Wilson, 1987). However, the meaning of manhood has been treated as largely unidimensional and universal-man as economic provider and as head of the family. Further, what Black men are and what they should be is measured against the status and privilege of White males. The result is that we know little about how Black men define themselves either within or beyond conventional notions of masculinity and manhood.