Showing papers by "Clemson University published in 1995"
TL;DR: Direct evidence is provided that the cAMP-dependent protein kinase is necessary for infection-related morphogenesis and pathogenesis in a phytopathogenic fungus.
Abstract: Magnaporthe grisea, the causal agent of rice blast disease, differentiates a specialized infection cell, an appressorium, that is required for infection of its host. Previously, cAMP was implicated in the endogenous signaling pathway leading to appressorium formation. To obtain direct evidence for the role of cAMP in appressorium formation, the gene encoding the catalytic subunit of the cAMP-dependent protein kinase (cpkA) was cloned, sequenced, and disrupted. Polymerase chain reaction primers designed after highly conserved regions in the same gene from other organisms were used to amplify genomic DNA fragments. The cloned amplification products were used to identify genomic clones. DNA blot analysis indicated that cpkA is present as a single copy in the genome. cpkA consists of 1894 bp, including three short introns sufficient to encode a protein of 539 amino acids with a predicted molecular mass of 60.7 kD. The deduced peptide shares > 45% identity with other catalytic subunits and contains all functional motifs and residues with the addition of a glutamine-rich region at the N terminus. Two transformants, L5 and T-182, in which cpkA had been replaced with a hygromycin resistance gene cassette, were unable to produce appressoria, could not be induced to form appressoria by cAMP, and were nonpathogenic on susceptible rice, even when leaves were abraded. These results were confirmed by analysis of 57 progeny from a cross between transformant L5 and the wild-type laboratory strain 70-6. Other aspects of growth and development, including vegetative growth as well as asexual and sexual competence, were unaffected when measured in vitro. These results provide direct evidence that the cAMP-dependent protein kinase is necessary for infection-related morphogenesis and pathogenesis in a phytopathogenic fungus.
369 citations
TL;DR: In this article, a general framework identifying groups of interactive parameters and assessing wear material performance through investigating these groups of parameter is presented, which is suggested that material loss can be rationalized from the understanding and description of the three wear precursors which delineate the groups of parameters, being surface, subsurface and third body behavior.
344 citations
TL;DR: In this paper, the authors examined the dilemma of green consumers with negative impressions of the advertising industry from a variety of perspectives and concluded that many green consumers have negative attitudes about business.
Abstract: As ecological concerns evolve and diffuse throughout society, advertisers are interested in developing green (i.e., environmental) messages and are interested in targeting green customer segments. Unfortunately for advertisers, many green consumers have negative attitudes about business, and they often have negative impressions of the advertising industry. Here, this dilemma is examined from a variety of perspectives.
303 citations
TL;DR: The Beehr model of retirement behavior was used in this study and showed that chronological age, employee health, and self-perceptions of the ability to adjust to retirement predicted subsequent planned retirement age.
Abstract: Given the aging workforce, understanding the retirement process is an area of increasing interest to organizations. T. A. Beehr's (1986) model of retirement behavior was used in this study as a basis for selecting personal, psychological, and organizational predictors of subsequent planned retirement age. In addition, potential differences in predictors of the planned retirement age of retirementeligible and retirement-ineligible respondents were explored. Two hundred sixty-four respondents working for a large multinational firm completed 2 surveys on their attitudes toward work and retirement. Results showed that chronological age, employee health, and self-perceptions of the ability to adjust to retirement predicted subsequent planned retirement age. Interactions of the predictors with retirement eligibility are reported along with implications for retirement-planning programs. The advantages of predicting retirement age are apparent to those fulfilling personnel functions within organizations. The ability to predict when employees will leave an organization enhances flexibility in staffing and estimating pensions. Furthermore, an understanding of the factors that concern retirees may allow employers to develop more effective retirement-planning programs. Despite extensive research on the retirement decision, only limited information on the role of psychological and organizational variables has reached the industrial-organizational psychology literature (Talaga & Beehr, 1989). The purpose of the present study was to examine the influence of a selected subset of these variables on the retirement decision. In response to the lack of information on retirement among industrial-organizational psychologists, a comprehensive model of retirement behavior that incorporated personal factors and environmental forces was developed by Beehr (1986). The personal factors related to retirement include health and economic wellbeing, whereas environmental factors include two categories of work-related (e.g., job characteristics) and nonwork factors (e.g., leisure interests). Beehr proposed that each of these factors may function as a "push" on the worker to leave the workforce or a "pull" to keep the worker in the workforce. Thus, retirement should not be considered as a purely voluntary decision, because it is influenced by practical constraints. There are a number of limitations in the retirement literature at present (Talaga & Beehr, 1989). Although many researchers have confirmed the impact of such variables as retiree health and financial situation on the retirement decision (Quinn & Burkhauser, 1990), the incremental contribution of workrelated affective states and retirement-related psychological variables are often not examined. Many studies include variables from one or two of the three categories within Beehr's (1986) model but not all three of the categories. One goal of the present study was to examine the relative contribution of personal, organizational, and psychological factors to the prediction of planned retirement age. Within this article, the term personal factors is used to refer to the traditional predictors of health and financial situation. Psychological factors refer to attitudes toward retirement, including retirement self-efficacy, expectations about social aspects of retirement, and leisure orientation. The third major category of predictors is labeled job and organizational factors and incorporates job satisfaction, organizational commitment, and the extent to which the organization has fulfilled the individual's retirement support needs. Although the categories are consistent with Beehr's model, we chose the individual predictors within each category on the basis of several criteria, including Beehr's (1986) suggestions, current research on retirement, and other related literature on self-efficacy (Bandura, 1977). A second area that has received limited attention in the literature is the effect of proximity to retirement on the predictors of the retirement decision. Past research indicates that a linear increase in retirement preparation behaviors takes place over a 15-year period before retirement (Evans, Ekerdt, & Bosse, 1985) and that the retirement process takes place years before and after the actual workforce exit (Beehr, 1986). This suggests that retirement is an ongoing process rather than a discrete event. A second goal of this study was to explore potential differences in predictors of estimated retirement age as a function of the retirement eligibility status of the employee.
259 citations
TL;DR: Physicochemical parameters such as wettability and surface free energy influence cell growth but play no measurable role in the shape and orientation of cells on microtextured surfaces.
Abstract: To evaluate the effect of surface treatment and surface microtexture on cellular behavior, smooth and microtextured silicone substrata were produced. The microtextured substrata possessed parallel surface grooves with a width and spacing of 2.0 (SilD02), 5.0 (SilD05), and 10 microns (SilD10). The groove depth was approximately 0.5 microns. Subsequently, these substrata were either left untreated (NT) or treated by ultraviolet irradiation (UV), radiofrequency glow discharge treatment (RFGD), or both (UVRFGD). After characterization of the substrata, rat dermal fibroblasts (RDF) were cultured on the UV, RFGD, and UVRFGD treated surfaces for 1, 3, 5, and 7 days. Comparison between the NT and UV substrata revealed that UV treatment did not influence the contact angles and surface energies of surfaces with a similar surface topography. However, the contact angles of the RFGD and UVRFGD substrata were significantly smaller than those of the UV and NT substrata. The dimension of the surface microevents did not influence the wettability characteristics. Cell culture experiments revealed that RDF cell growth on UV-treated surfaces was lower than on the RFGD and UVRFGD substrata. SEM examination demonstrated that the parallel surface grooves on the SilD02 and SilD05 substrata were able to induce stronger cell orientation and alignment than the events on SilD10 surfaces. By combining all of our findings, the most important conclusion was that physicochemical parameters such as wettability and surface free energy influence cell growth but play no measurable role in the shape and orientation of cells on microtextured surfaces.
235 citations
TL;DR: The authors compared risk avoidance strategies employed by business angels and venture capital firm investors and found that differences in their approaches to evaluating risk lead them to hold predictably different views of the dangers of market and agency risk.
Abstract: This research compares risk avoidance strategies employed by business angels and venture capital firm investors. It finds that differences in their approaches to evaluating risk lead them to hold predictably different views of the dangers of market and agency risk. the former tend to rely upon the entrepreneur to protect them from losses due to market risk. Consequently, they are more concerned with agency risk than market risk. the latter are more concerned with market risk because they have learned to protect themselves contractually from agency risk using boilerplate contractual terms and conditions. A likely result of their different approaches to avoiding risk is a segmentation of venture capital markets, which has important implications for both entrepreneurs and future research.
222 citations
TL;DR: An expert system tool that considers the various parameters that affect the production of the prototype and interacts with the user to recommend the best direction to build and is based both on the user's input and on a decision matrix based on the result of interviews with experts.
Abstract: Current commercial rapid prototyping technologies are based on a layered additive process to build parts. The layer-based process results in a stairstepping effect, which can be apparent on curved and sloped surfaces. The selection of the build orientation, whether based on experience, trial and error, or not even considered, is one critical factor that affects the quality of the surface finish. Furthermore, it influences other important aspects, such as the build time and the amount of support structure needed. The authors propose an expert system tool that considers the various parameters that affect the production of the prototype and interacts with the user to recommend the best direction to build. The recommendation is based both on the user's input and on a decision matrix based on the result of interviews with experts, which is implemented within the expert system. If an optimal orientation is not possible, the tool helps the user to select an acceptable build direction. The expert system can also draw attention to issues such as trapped volumes, which can be detrimental to the build process. It helps to reduce the design time, to automate the build process and to minimize the cost of the prototype. The results of this work form a base for ongoing research to complete a tool that considers all major issues for a preferred orientation.
210 citations
TL;DR: The authors found that the more either type of investor is concerned with market or agency risk, the less likely he or she will be to use informal network informants (business associates and friends).
169 citations
TL;DR: Development of glyphosate-tolerant soybean promises to provide the farmer with access to a new weed control system that should result in lower production costs and reliable weed control under a wide range of conditions.
Abstract: Transformation of soybean [Glycine max (L.) Merr.] with a gene encoding a glyphosate-tolerance 5-enolpyruvylshikimate-3-phosphate synthase enzyme from Agrobacterium sp. strain CP4 resulted in the development of glyphosate-tolerant line 40-3-2. Glyphosate (N-phosphonomethyl glycine) is the active ingredient of Roundup herbicide. Line 40-3-2 was yield tested at 17 locations in 1992, 23 locations in 1993, and 18 locations in 1994. At those locations, broadcast applications of glyphosate at various rates were made over 40-3-2 or its derivatives from early vegetative growth to pod fill. No significant yield reduction was observed as a result of the glyphosate treatment at any of the locations. Development of glyphosate-tolerant soybean promises to provide the farmer with access to a new weed control system that should result in lower production costs and reliable weed control under a wide range of conditions.
155 citations
TL;DR: A complex cellular mechanism through a cytokine/prostaglandin cascade may regulate the observed bone resorption in aseptic loosening in total hip arthroplasties.
Abstract: The interfacial membrane between implant and host—bone in aseptically loose total hip arthroplasties has a potential role in the etiology of local bone resorption and loosening of the prosthetic component. Inflammatory/potential “bone-resorbing” agents (cytokines/mediators) released by the cells of the interfacial membranes of loosened uncemented and cemented total hip arthroplasties were measured. Synovial tissues from patients with acute femoral neck fractures, patients with osteoarthritis, and cadavers without joint disorders were used as control subjects. Control synovial tissue from osteoarthritic patients secreted the highest levels of prostaglandin E 2 , interleukin-8, and tumor necrosis factor alpha. Interleukin-1α was the only cytokine whose levels were elevated as much as 4-fold around uncemented implants compared with cemented implants, and up to 16-fold compared with control synovial tissue. An apparent inverse relation between interleukin-1α and interleukin-6 interfacial membranes of total hip arthroplasties compared with control synovial tissues suggests a complex cellular mechanism through a cytokine/prostaglandin cascade; this may regulate the observed bone resorption in aseptic loosening.
149 citations
TL;DR: This paper integrated a multidimensional conceptualization of empathy from the psychology literature with existing theory from marketing literature to suggest that perspective taking, empathic concern, emotional contagion, and controlling behaviors will differentially effect salesperson performance.
Abstract: Prior studies of empathy have yielded conflicting findings regarding the effectiveness of empathy in improving salesperson performance. This article integrates a multidimensional conceptualization of empathy from the psychology literature with existing theory from marketing literature to suggest that perspective taking, empathic concern, emotional contagion, and controlling behaviors will differentially effect salesperson performance. Responses from a survey of business-to-business salespeople indicate that empathy has both positive and negative effects. Implications of the findings are explored. © 1995 John Wiley & Sons, Inc.
TL;DR: Rural development in the United States as mentioned in this paper presents a comprehensive evaluation of the economic, environmental, and political implications of past rural development and a thorough consideration of the directions in which future development efforts should go.
Abstract: "Rural Development in the United States" presents a comprehensive evaluation of the economic, environmental, and political implications of past rural development and a thorough consideration of the directions in which future development efforts should go. The authors have assembled the best of what is being thought and done with regard to rural development in the United States, and place it in a broad theoretical, historical, and geographical context. The book provides: a summary of the key findings in rural development research of the past twenty years an integration of development theory and practical experience a bridge between the related but often isolated disciplines that inform rural development a catalyst for new thinking in the area of rural development analysis of the key economic sectors in rural areas: natural resources, the service sector, elderly services, telecommunications, manufacturing, tourism, and high-technology It includes important information about how national and international trends affect rural communities and development strategies and will help guide rural economic development policy in the United States during the 1990s and beyond.
TL;DR: In this paper, the influence of social and work roles are incorporated into a model of retirement adjustment, along with two psychological moderators that may aid the retirement transition, which are those behavioral predispositions that would lead one to engage in proactive strategies for mastering the role changes inherent in the transition.
Abstract: In this review, the influence of social and work roles are incorporated into a model of retirement adjustment, along with two psychological moderators that may aid the retirement transition. These psychological resources, locus of control and retirement self-efficacy, are those behavioral predispositions that would lead one to engage in proactive strategies for mastering the role changes inherent in the retirement transition. The implications of social and work-related role changes and psychological resources for retirement planning and adjustment are discussed. Contemporary discussion of the retirement process seems to be characterized by description rather than by explanation. Although variables that significantly correlate with retirement adjustment have been identified, inconsistencies in the predictive strength of these variables often emerge across studies. This suggests a need for a greater understanding of the processes constituting the retirement transition. Reviewers have provided very useful frameworks for consolidating past research on predictors of retirement (Atchley, 1979; Talaga & Beehr, 1989), yet less information is available on the psychological factors that underlie retirement adjustment. Role theory is a potentially useful framework for examining the retirement transition. Roles consist of activities and behaviors that characterize a person in a given social context and may be fundamental in understanding adjustment to change (George, 1990). Role theory suggests that certain socially prescribed and personally relevant roles are critical in self-identity. These self-defined roles may emerge through one's relationship to close personal associates (e.g., mother, friend) and may also stem from valued activities experienced in the work roles (e.g., physician), from voluntary group affiliations (e.g., bridge clubs), and from leisure activities (e.g., gardener, photographer). Individual differences in adjustment to change can be understood by examining the shifts in critical role activity that accompany life transitions. Research by George ( 1990) has shown that role theory can be used as a foundation for understanding retirement adjustment. She used role theory to predict how older people negotiate age-related changes and reported that a person's success in negotiating and managing the necessary shifts in activities that result from role change and redefinition determine adjustment. This role-based approach may be applied to the retirement process, because leaving the workforce necessitates a shift in roles and activities. Variation in retirement adjustment may be attributable to individual differences in the ability to make these role and activity shifts. Retirement may be viewed, then, as a transition that involves role expansion, redefinition, and change. Role activities that may diminish are those that depend on contact with coworkers and activities involved in the execution of work functions. Thus, social roles whose maintenance depends on coworker interactions and professional roles that are based on work behaviors would be strongly influenced by workforce exit. The influence of such postretirement role loss on the individual would depend on the self-rated importance of these work-dependent roles and on the availability of other satisfying substitutes for the old roles. This literature review integrates research on these social and work-oriented roles and explores their relationship to the retirement experience. The influence of social and work roles is incorporated into an overview of retirement adjustment, along with two psychological factors that may aid the retirement transition. First, we report empirical research on the relationship between social roles and adjustment. These social roles include relationships with friends and family members, affiliations with social groups, and leisure activities. Next, we discuss roles that are based on work activities and the effect of workforce exit. …
Abstract: The study investigated whether negotiators' behaviors were related to changes in their opponents' initial trust, and whether trust and behaviors were related to their own goal achievement. Hypothes...
TL;DR: Ongoing research in the synthesis and properties of novel polymeric materials containing superacid sulfonimide functions is discussed in this article, where novel perfluorinated ionomers and ionene polymers have been prepared and characterized.
TL;DR: It seems that the alkaloids of E+ tall fescue are serving as D2 dopamine receptor agonists, this activity would explain their prolactin-lowering effect.
Abstract: Gravid mares grazing endophyte-infested (E+) tall fescue exhibit increased gestation lengths, agalactia, foal and mare mortality, tough and thickened placentas, weak and dysmature foals, increased sweating during warm weather, reduced serum prolactin and progesterone, and increased serum estradiol-17 beta levels. Also, E+ tall fescue hay is less digestible than endophyte-free (E-) hay. Unlike many other species, horses consuming E+ tall fescue do not exhibit increased body temperature. Young horses consuming only E+ pasture do not gain as well as those consuming E- pasture. There is little difference in gain when the pasture is supplemented with enough concentrate to meet NRC requirements for growth. Neither selenium injections nor supplementing with corn at 50% of the NRC requirements for energy reduces the effects of toxic tall fescue on reproduction and lactation in gravid mares. It seems that the alkaloids of E+ tall fescue are serving as D2 dopamine receptor agonists. This activity would explain their prolactin-lowering effect. Domperidone, a dopamine receptor antagonist, is effective in preventing the signs of tall fescue toxicosis in horses without neuroleptic side effects.
TL;DR: This paper examined the formation of assassination attitudes among subjects with no initial opinion and found that the process of biased assimilation leads to attitude polarization rather than to a moderation or reversal of existing attitudes.
Abstract: Vitriolic debate surrounds John F. Kennedy's (JFK's) death more than 30 years after the assassination. Whereas some endorse the official government conclusion that Oswald acted alone, others allege that some form of a conspiracy is responsible for Kennedy's death. The central thesis of this article is that due to the processes of biased assimilation and attitude polarization, personal theories about the perpetrator(s) of the assassination are essentially immutable, and therefore that the debate surrounding JFK's assassination will continue endlessly. Due to the process of biased assimilation, proponents of both the Oswald and conspiracy theories perceive the same body of evidence as supportive of their position. Biased assimilation leads to attitude polarization rather than to a moderation or reversal of existing attitudes. The results of the present study strongly support this line of reasoning. The study also examined the formation of assassination attitudes among subjects with no initial opinion. The m...
TL;DR: This work has constructed a genetic linkage map of peach based on 71 F2 individuals derived from the self-fertilization of four F1 individuals of a cross between ‘New Jersey Pillar’ and KV 77119, suggesting that RFLP markers from the WV family have a high probability of being polymorphic in crosses generated with other peach cultivars, making them ideal for anchor loci.
Abstract: We have constructed a genetic linkage map of peach [Prunus persica (L.) Batsch] consisting of RFLP, RAPD and morphological markers, based on 71 F2 individuals derived from the self-fertilization of four F1 individuals of a cross between 'New Jersey Pillar' and KV 77119. This progeny, designated as the West Virginia (WV) family, segregates for genes controlling canopy shape, fruit flesh color, and flower petal color, size and number. The segregation of 65 markers, comprising 46 RFLP loci, 12 RAPD loci and seven morphological loci, was analyzed. Low-copy genomic and cDNA probes were used in the RFLP analysis. The current genetic map for the WV family contains 47 markers assigned to eight linkage groups covering 332 centi Morgans (cM) of the peach nuclear genome. The average distance between two adjacent markers is 8 cM. Linkage was detected between Pillar (Pi) and double flowers (Dl) RFLP markers linked to Pi and flesh color (γ) loci were also found. Eighteen markers remain unassigned. The individuals analyzed for linkage were not a random sample of all F2 trees, as an excess of pillar trees were chosen for analysis. Because of this, Pi and eight other markers that deviated significantly from the expected Mendelian ratios (e.g., 1∶2∶1 or 3∶1) were not eliminated from the linkage analysis. Genomic clones that detect RFLPs in the WV family also detect significant levels of polymorphism among the 34 peach cultivars examined. Unique fingerprint patterns were created for all the cultivars using only six clones detecting nine RFLP fragments. This suggests that RFLP markers from the WV family have a high probability of being polymorphic in crosses generated with other peach cultivars, making them ideal for anchor loci. This possibility was examined by testing RFLP markers developed with the WV family in three other unrelated peach families. In each of these three peach families respectively 43%, 54% and 36% of RFLP loci detected in the WV family were also polymorphic. This finding supports the possibility that these RFLP markers may serve as anchor loci in many other peach crosses.
TL;DR: In this paper, the current abundances and spatial distributions of two key gamma-ray radioactivities, {sup 26}Al and {sup 60}Fe, are determined using recently calculated yields for Type II supernovae, along with models for chemical evolution and distribution of mass in the interstellar medium.
Abstract: Using recently calculated yields for Type II supernovae, along with models for chemical evolution and the distribution of mass in the interstellar medium, the current abundances and spatial distributions of two key gamma-ray radioactivities, {sup 26}Al and {sup 60}Fe, are determined. The estimated steady state production rates are 2.0{plus_minus}1.0 {ital M}{sub {circle_dot}} Myr{sup -1} for {sup 26}Al and 0.75{plus_minus}0.4 {ital M}{sub {circle_dot}} Myr{sup -1} for {sup 60}Fe. This corresponds to 2.2{plus_minus}1.1 {ital M}{sub {circle_dot}} of {sup 26}Al and 1.7{plus_minus}0.9 {ital M}{sub {circle_dot}} of {sup 60}Fe in the present interstellar medium. Sources of uncertainty are discussed, one of the more important being the current rate of core collapse supernovae in the Galaxy. Our simple model gives three per century, but reasonable changes in the star formation rate could easily accommodate a core collapse rate one-half as large, and thus one-half the yields. When these stellar and chemical evolution results are mapped into a three-dimensional model of the Galaxy, the calculated 1809 keV gamma-ray flux map is consistent with the {ital Compton} {ital Gamma} {ital Ray} {ital Observatory} observations of a steep decline in the flux outside a longitude of {plus_minus}50{degree} from the Galactic center, and the slight flux enhancements observed in more » the vicinity of spiral arms. Other potential stellar sources of {sup 26}Al and {sup 60}Fe are mentioned, especially the possibility of {sup 60}Fe synthesis in Type Ia supernovae. Predictions for the {sup 60}Fe mass distribution, total mass, and flux map are given. {copyright} {ital 1995 The American Astronomical Society.} « less
TL;DR: Machiavellianism scores were positively associated with aspects of narcissism which indicate maladjustment, and inversely associated with adaptive narcissistic tendencies, i.e., self-sufficiency.
Abstract: Associations of Machiavellianism and narcissism were examined in two samples (Ns = 214 and 205) via the Mach-IV and the Narcissistic Personality Inventory. Scores on these self-report measures were correlated. Machiavelianism scores were positively associated with aspects of narcissism which indicate maladjustment, i.e., entitlement and exploitativeness, and inversely associated with adaptive narcissistic tendencies, i.e., self-sufficiency. The discussion focuses on the relative adjustment of those scoring high on Machiavelianism.
TL;DR: A Monte Carlo Analysis was utilized to simulate an HRM research setting to evaluate missing data techniques and pairwise deletion resulted in the least dispersion around true scores and least average error of any missing data technique for calculating correlations.
TL;DR: In this paper, the benefits, requirements, and potential drawbacks of cooperative learning in large enrollment, college courses are considered, and the benefits and requirements for cooperative learning are compared in large-scale courses.
Abstract: Consideration of the benefits, requirements, and potential drawbacks of cooperative learning in large enrollment, college courses.
TL;DR: Insertion of the leading order hard sphere virial expansions for \ensuremath{\eta} and the osmotic compressibility into the generalized SE equation gives a virial expansion which is consistent with theoretical estimates obtained by alternative methods.
Abstract: The cooperative diffusion coefficient ${\mathit{D}}_{\mathit{c}}$ for spherical particle suspensions is calculated using a ``mode-coupling'' method which extends previous calculations of ${\mathit{D}}_{\mathit{c}}$ for critical fluids and semidilute polymer solutions. The renormalization of the viscosity in the velocity-velocity correlation function from the solvent to the suspension viscosity leads to a generalized Stokes-Einstein (SE) equation in which the suspension viscosity \ensuremath{\eta} replaces the solvent viscosity ${\mathrm{\ensuremath{\eta}}}_{0}$ and the correlation length \ensuremath{\xi} (related to the osmotic compressibility) replaces the sphere radius R at nonvanishing suspension concentrations. Insertion of the leading order hard sphere virial expansions for \ensuremath{\eta} and the osmotic compressibility into our generalized SE equation gives a virial expansion for ${\mathit{D}}_{\mathit{c}}$ which is consistent with theoretical estimates obtained by alternative methods. These leading order virial expansions are also consistent with experiments on model (``hard sphere'') suspensions. Results are given for the virial expansion of spherical liquid droplets interacting via a contact attractive interaction. Further experiments are required to test the generalized SE equation at higher suspension concentrations.
TL;DR: An algorithm, which is based on Kalman filter estimation, can be used to predict the instantaneous flicker level and is developed to estimate the instantaneous magnitude and frequency of the voltage flicker.
Abstract: Voltage flicker refers to a slow-0.5 to 30 Hz-modulation of the power system voltage magnitude. This periodic fluctuation can be modelled as an amplitude modulated signal, where the fundamental power frequency represents the carrier signal and the voltage flicker represents the modulating signal. An algorithm based on this premise is developed to estimate the instantaneous magnitude and frequency of the voltage flicker. The algorithm, which is based on Kalman filter estimation, can also be used to predict the instantaneous flicker level. >
TL;DR: The purpose of this article is to show how the design procedure commonly referred to as integrator backstepping can be used to design globally stable trajectory tracking controllers for Rigid-Link Flexible-Joint (RLFJ) robot manipulators.
Abstract: The purpose of this article is to show how the design procedure commonly referred to as integrator backstepping can be used to design globally stable trajectory tracking controllers for Rigid-Link Flexible-Joint (RLFJ) robot manipulators. Three different types of controllers are developed: (1) an exact model knowledge-based controller, (2) an adaptive controller that compensates for parametric uncertainty, and (3) a robust controller that compensates for parametric uncertainty and unknown bounded disturbances. All three controllers are based on previously published work but are presented here in a unifying framework. © 1995 John Wiley & Sons, Inc.
TL;DR: In this paper, the authors present a table giving the yields of 103 isotopes in eight distinct zones in the ejecta from the explosion of a 25 M star, each zone is distinct isotopically due to the evolution and explosion of the star.
Abstract: — We present a table giving the yields of 103 isotopes in eight distinct zones in the ejecta from the explosion of a 25 M star. Each zone in the ejecta is distinct isotopically due to the evolution and explosion of the star. Thus the table not only gives the yields of isotopes in the different zones of the ejecta but also provides information about the chemical environments in which each isotope is injected into the interstellar medium.
The table is a summary of the nuclear yields from a single numerical model of the explosion of a massive star. The yields from a real supernova will vary from those in this table because of uncertainties in the input physics to the numerical model and because the real star may differ in mass, mass-loss rate, or metallicity from the modeled star. We argue that these uncertainties and variations, for the most part, will not change the direction of the largest isotopic effects in the different zones of the ejecta. This means that the table is quite generally applicable as a guide to understanding the ejecta of supernovae and as a characterization of possible chemical environments in which isotopes are injected into the interstellar medium.
TL;DR: In this paper, the design and synthesis of a series of 1-alkyl-3-(1-naphthoyl) pyrroles is described, and molecular modeling studies are employed to aid in the design of these compounds.
TL;DR: In this paper, the authors discuss the source of the enhanced carbon and oxygen low-energy cosmic-ray flux in the Orion star-forming region and attribute it to the acceleration of the surface layers of a massive supernova, probably of Type Ib.
Abstract: We discuss the source of the enhanced carbon and oxygen low-energy cosmic-ray flux in the Orion star-forming region and attribute it to the acceleration of the surface layers of a massive supernova, probably of Type Ib. The gamma rays from Orion are produced by that fast CO ejecta. In this model there would be few Orion-like gamma-ray sources in the Galaxy at any one time. We also postulate that a massive supernova produced the short-lived extinct radioactivities injected into the molecular cloud core that produced the solar system. We find that relative to 26Al the other short-lived extinct radioactivities are excessively produced in massive supernovae but are likely to be more attenuated by postexplosion fallback than 26Al. This is a revival of the supernova trigger hypothesis; to obtain the correct dilutions of the extinct radioactivities, the distance from the supernova to the impacted molecular cloud core must be a few parsecs, and the effective projected collecting area of the cloud must be significantly less than normal core radii.
TL;DR: Freezing the master production schedule is the most effective approach in terms of reducing both instability and cost as the freeze length covers the cumulative lead time and is the least sensitive to changes in operating conditions.
TL;DR: In this article, the high voltage wearout and breakdown of thin silicon oxides has been described in terms of traps generated inside of the oxide and at the interfaces by a high field emission process.
Abstract: The high voltage wearout and breakdown of thin silicon oxides has been described in terms of traps generated inside of the oxide and at the interfaces by a high field emission process. The trap generation was accompanied by the motion of atoms which resulted in permanent traps fixed in space. Breakdown occurred when the local density of traps exceeded a critical density. The charge state of these traps could easily be changed by application of low voltages after the high voltage stresses. The energy levels of the traps varied depending on the probability of trap generation. This model has been applied to analyze the thickness, field, polarity, time, and temperature dependences of oxide wearout and breakdown observed in oxides thinner than 22 mn. It was concluded that the wearout process in oxides thinner than 22 nm was determined by the electric fields applied to the oxides and not by the passage of currents through the oxides. >