We introduce a new “positive formalism” for encoding quantum theories in the general boundary formulation, somewhat analogous to the mixed state formalism of the standard formulation. This makes the probability interpretation more natural and elegant, eliminates operationally irrelevant structure and opens the general boundary formulation to quantum information theory.
Funding agencies in Canada are attempting to break down the organizational boundaries between disciplines to promote interdisciplinary research and foster the integration of the social sciences into the health research field. This paper explores the extent to which biomedical and clinician scientists’ perceptions of social science research operate as a cultural boundary to the inclusion of social scientists into this field. Results indicated that cultural boundaries may impede social scientists’ entry into the health research field through three modalities: (1) (...) biomedical and clinician scientists’ unfavourable and ambivalent posture towards social science research; (2) their opposition to a resource increase for the social sciences; and (3) clinician scientists procedural assessment criteria for social science. The paper also discusses the merits and limitations of Tom Gieryn’s concept of boundary-work for studying social dynamics within the field of science. (shrink)
Despite its vigor, agrifood studies research faces two fault lines: the durability of disciplines, and challenges in engaging non-academic stakeholders. In this essay, I use the concept of boundary work from social studies of science and technology to reflect on the challenges and opportunities for more engaged interdisciplinary research in agrifood studies. I draw on recent field visits to several “sustainable food chain” research projects funded through the Rural Economy and Land Use Programme (RELU), an innovative interdisciplinary research initiative (...) of the UK Research Councils, to highlight the contradictory nature of boundary work in interdisciplinary research. Involving efforts both to bridge interfaces and to separate, exclude and manage other disciplines or stakeholders, boundary work is inherent to interdisciplinarity. Innovations in the organizational culture of projects and in the larger structural context for research can multiply the more generative potential of boundary work, and also yield more and better interdisciplinary research in agrifood studies. (shrink)
Prosodic information is crucial for spoken language comprehension and especially for syntactic parsing, because prosodic cues guide the hearer’s syntactic analysis. The time course and mechanisms of this interplay of prosody and syntax are not yet well understood. In particular, there is an ongoing debate whether local prosodic cues are taken into account automatically or whether they are processed in relation to the global prosodic context in which they appear. The present study explores whether the perception of a prosodic (...) class='Hi'>boundary is affected by its position within an utterance. In an event-related potential (ERP) study we tested if the brain response evoked by the prosodic boundary differs when the boundary occurs early in a list of three names connected by conjunctions (i.e., after the first name) as compared to later in the utterance (i.e., after the second name). A closure positive shift (CPS) — marking the processing of a prosodic phrase boundary — was elicited only for stimuli with a late boundary, but not for stimuli with an early boundary. This result is further evidence for an immediate integration of prosodic information into the parsing of an utterance. In addition, it shows that the processing of prosodic boundary cues depends on the previously processed information from the preceding prosodic context. (shrink)
An extended version of Gieryn's notion of ‘boundary-work’, supplemented with insights of Thomas Goodnight, is used to represent the central role of rhetoric in disputes on the boundary of science and the public. From a study of the Tarasoff-case it is shown that the rhetorical process of turning obstacles into resources works to move the boundary between a science and the law. It is concluded that rhetorical scholars can and must play a part in the resolution of (...)boundary disputes and that concrete case-studies of boundary-work may deepen criticism of argument. (shrink)
This article traces the roots of the author’s doctoral work to his pre-doctoral experiences in varied realms of professional practice. The research choices made are thus inevitably influenced by these experiences. These include the selection of an interdisciplinary domain to locate his doctoral work, the choice of a “boundary object” as the unit of analysis and the formulation of a methodological mix that reflected the multidimensionality of the research topic. These choices also reflect the researcher’s quest for personal meaningfulness (...) and consequently, a certain degree of irrationality that is characteristic of any human endeavor. The idea of creative research as negotiating the boundary of acceptability is explored and the importance of freedom and tolerance for experimentation to aid this enterprise is highlighted. (shrink)
Previous studies have revealed that infants aged six to ten months are able to use the acoustic correlates of major prosodic boundaries, that is, pitch change, preboundary lengthening, and pause, for the segmentation of the continuous speech signal. Moreover, investigations with American-English- and Dutch-learning infants suggest that processing prosodic boundary markings involves a weighting of these cues. This weighting seems to develop with increasing exposure to the native language and to underlie crosslinguistic variation. In the following, we report the (...) results of four experiments using the headturn preference procedure to explore the perception of prosodic boundary cues in German infants. We presented eight-month-old infants with a sequence of names in two different prosodic groupings, with or without boundary markers. Infants discriminated both sequences when the boundary was marked by all three cues (Experiment 1) and when it was marked by a pitch change and preboundary lengthening in combination (Experiment 2). The presence of a pitch change (Experiment 3) or preboundary lengthening (Experiment 4) as single cues did not lead to a successful discrimination. Our results indicate that pause is not a necessary cue for German infants. Pitch and preboundary lengthening in combination, but not as single cues, are sufficient. Hence, by eight months infants only rely on a convergence of boundary markers. Comparisons with adults’ performance on the same stimulus materials suggest that the pattern observed with the eight-month-olds is already consistent with that of adults. We discuss our findings with respect to crosslinguistic variation and the development of a language-specific prosodic cue weighting. (shrink)
Cultural-nationalist and democratic theory both seek to legitimize political power via collective self-rule: their principle of legitimacy refers right back to the very persons over whom political power is exercised. But such self-referential theories are incapable of jointly solving the distinct problems of legitimacy and boundaries, which they necessarily combine, once it is assumed that the self-ruling collectivity must be a pre-political, in-principle bounded, ground of legitimacy. Cultural nationalism claims that political power is legitimate insofar as it expresses the nation’s (...) pre-political culture, but it cannot fix cultural-national boundaries pre-politically. Hence the collapse into ethnic nationalism. Traditional democratic theory claims that political power is legitimized pre-politically, but cannot itself legitimize the boundaries of the people. Hence the collapse into cultural nationalism. Only once we recognize that the demos is in principle unbounded, and abandon the quest for a pre-political ground of legitimacy, can democratic theory fully avoid this collapse of demos into nation into ethnos. But such a theory departs radically from traditional theory. (shrink)
Dialogue is a seminal concept within the work of the Brazilian adult education theorist, Paulo Freire, and the Russian literary critic and philosopher, Mikhail Bakhtin. While there are commonalities in their understanding of dialogue, they differ in their treatment of dialectic. This paper addresses commonalities and dissonances within a Bakhtin-Freire dialogue on the notions of dialogue and dialectic. It then teases out some of the implications for education theory and practice in relation to two South African contexts of learning that (...) facilitate the access to education of disadvantaged groups, one in higher education and the other in early childhood education. (shrink)
As a domain of philosophical enquiry that examines what it means to be, existentialism is a moral project that is centered on the self. While a few have applied the precepts of existentialism to the philosophical implications of homicide offenders, one question that has been overlooked in previous literature is 'what is the offspring attempting to do by killing his/her parent(s)'? Using historical work on nineteenth century parricides in America, this paper examines parricide as an identity project.
The Gricean distinction between saying and implicating suggests a clear division of labour between semantics and pragmatics. The standard view that a semantic theory delivers truth-conditions for every well-formed sentence of a language has been grafted onto a Gricean view of the semantics-pragmatics divide. Consequently, many believe that truth-conditions can be specified in a way that is essentially free from pragmatic considerations. This view has been challenged, by those who argue for pragmatic intrusion into truth-conditional content. Others have argued in (...) favour of preserving a pragmatically untainted conception of semantics, but for a more finegrained conception of pragmatics. This debate has led to different proposals as to how to draw the boundary between semantics and pragmatics. This philosophical debate has been conducted largely independently of the debate in linguistics about the interfaces between the various sub-systems of the language faculty in the mind/brain. (shrink)
In evidence-based medicine (EBM), methodology has become the central means of determining the quality of the evidence base. The “gold standard” method, the randomised, controlled trial (RCT), imbues medical research with an ethos of disinterestedness; yet, as this essay argues, the RCT is itself a rhetorically interested construct essential to medical-professional boundary work. Using the example of debates about methodology in EBM-oriented research on complementary and alternative medicine (CAM), practices not easily tested by RCTs, I frame the problem of (...) method as a fundamentally rhetorical problem, situated within a boundary drama, and deeply rooted in the discursive practices of science and medicine. The genre of the RCT report, for example, idealises the research process and can tilt the course of arguments about CAM, while the notion of efficacy can function as a rhetorically mobile boundary object that can redefine the very terms of debate. I suggest herein that arguments about method in CAM debates can productively be read, metonymically, as expressions of more general anxieties in medicine about knowledge and evidence, community values, and professional boundaries; as such, these debates can illuminate some of the rhetorical dimensions of EBM. (shrink)
Physics says that it cannot deal with the mind-brain problem, because it does not deal in subjectivities, and mind is subjective. However, biologists (among others) still claim to seek a material basis for subjective mental processes, which would thereby render them objective. Something is clearly wrong here. I claim that what is wrong is the adoption of too narrow a view of what constitutes objectivity, especially in identifying it with what a machine can do. I approach the problem in the (...) light of two cognate circumstances: (a) the measurement problem in quantum physics, and (b) the objectivity of standard mathematics, even though most of it is beyond the reach of machines. I argue that the only resolution to such problems is in the recognition that closed loops of causation are objective; i.e. legitimate objects of scientific scrutiny. These are explicitly forbidden in any machine or mechanism. A material system which contains such loops is called complex. Such complex systems thus must possess nonsimulable models; i.e. models which contain impredicativities or self-references which cannot be removed, or faithfully mapped into a single coherent syntactic time-frame. I consider a few of the consequences of the above, in the context of thus redrawing the boundary between subject and object. (shrink)
The emphasis on models hasn’t completely eliminated laws from scientific discourse and philosophical discussion. Instead, I want to argue that much of physics lies beyond the strict domain of laws. I shall argue that in important cases the physics, or physical understanding, does not lie either in laws or in their properties, such as universality, consistency and symmetry. I shall argue that the domain of application commonly attributed to laws is too narrow. That is, laws can still play an important, (...) though peculiar, role outside their strict domain of validity. I shall argue also that, by way of a trade-off, while the actual domain of application of laws should be seen as much broader. At the same time, what I call ‘anomic’ representational elements reveal themselves as central to the descriptive and explanatory power of theories and model: boundary conditions, state descriptions, structures, constraints, limits and mechanisms. I conclude with a brief consideration of how my discussion has consequences for discussion of understanding, unification, approximation and dispositional properties. I focus on examples from physics, macroscopic and microscopic, phenomenological and fundametal: shock waves, propagation of cracks, symmetry breaking, and others. This law-eccentric kind of knowledge is central to both modeling the world and intervening in it. (shrink)
This paper examines the possibility of setting a boundary between religion and “pseudo-religion” (or superstition). Philosophers of religion inspired by Ludwig Wittgenstein’s ideas, in particular, insist that religious language-use can be neither legitimated nor criticized from the perspective of non-religious language-games. Thus, for example, the “theodicist” requirement that the existence of evil should be theoretically reconciled with theism can be argued to be pseudo-religious (superstitious). Another example discussed in the paper is the relation between religion and morality. The paper (...) concludes by reflecting on the issue of relativism arising from the Wittgensteinian contention that the religion vs. pseudo-religion division can only be drawn within a religious framework, and on Wittgenstein’s own suggestion that the religious person “uses a picture”. (shrink)
Theories of political authority divide naturally into those that locate the source of states' authority in the history of states' interactions with their subjects and those that locate it in structural (or functional) features of states (such as the justice of their basic institutions). This paper argues that purely structuralist theories of political authority (such as those defended by Kant, Rawls, and contemporary “democratic Kantians”) must fail because of their inability to solve the boundary problem—namely, the problem of locating (...) the boundaries between different states' domains of authority in the natural or intuitive places. (shrink)
Where is the justificatory boundary between a true belief’s not being knowledge and its being knowledge? Even if we put to one side the Gettier problem, this remains a fundamental epistemological question, concerning as it does the matter of whether we can provide some significant defence of the usual epistemological assumption that a belief is knowledge only if it is well justified. But can that question be answered non-arbitrarily? BonJour believes that it cannot be – and that epistemology should (...) therefore abandon the concept of knowledge. More optimistically, this paper does attempt to answer that question, by applying – and thereby refining – a non-absolutist theory of knowledge. (shrink)
We think of a boundary whenever we think of an entity demarcated from its surroundings. There is a boundary (a surface) demarcating the interior of a sphere from its exterior; there is a boundary (a border) separating Maryland and Pennsylvania. Sometimes the exact location of a boundary is unclear or otherwise controversial (as when you try to trace out the margins of Mount Everest, or even the boundary of your own body). Sometimes the boundary (...) lies skew to any physical discontinuity or qualitative differentiation (as with the border of Wyoming, or the boundary between the upper and lower halves of a homogeneous sphere). But whether sharp or blurry, natural or artificial, for every object there appears to be a boundary that marks it off from the rest of the world. Events, too, have boundaries — at least temporal boundaries. Our lives are bounded by our births and by our deaths; the soccer game began at 3pm sharp and ended with the referee's final whistle at 4:45pm. And it is sometimes suggested that abstract entities, such as concepts or sets, have boundaries of their own. Whether all this boundary talk is coherent, however, and whether it reflects the structure of the world or the organizing activity of our intellect, are matters of deep philosophical controversy. (shrink)
This article on mystery and hope at the boundary of reason in the postmodern situation responds to the challenge of postmodern thinking to philosophyby a recourse to the works of Gabriel Marcel and his best disciple, Paul Ricoeur. It develops along the lines of their interpretation of hope as a central phenomenon in human experience and existence, thus shedding light on the philosophical enterprise for the future. It is our purpose to dwell briefly on this postmodern challenge and then, (...) incorporating its positive contribution, to present theirs as an alternative philosophy at the boundary of reason. (shrink)
Boundary crossings in academia are rarely addressed by university policy despite the risk of problematic or unethical faculty - student interactions. This study contributes to an understanding of undergraduate college student perceptions of appropriateness of faculty - student nonsexual interactions by investigating the influence of gender and ethnicity on student judgments of the appropriateness of numerous hypothetical interactions. Overall, students deemed the majority of interactions as inappropriate. Female students judged a number of interactions as more inappropriate than did male (...) students, and with a few exceptions, Mexican American and Anglo American students were similar in their ratings of the appropriateness of faculty - student interactions. These findings suggest that universities need to be proactive in establishing guidelines concerning faculty-student boundary crossings. (shrink)
The aim of this article is to examine ways in which localized research runs the risk of becoming a boundary discourse in a negative sense. The exaggerated emphasis on immanent critique, contextualization and incommensurability may lead discourse and disciplines to an isolationist self-understanding that leaves unchallenged or even entrenches existing discursive hegemonies. Or, it may side with the kind of facile and hasty fusion of discourses and disciplines that ignores epistemic demands and concerns for validity and semantic accuracy. That (...) is, it may overlook the necessity for positively understood discursive boundaries. Clearly demarcated, a-porous boundaries block osmosis and fruitful exchange and facilitate what is called here ?stronghold fortification?. And they make common cause with a disregard for all boundaries, i.e. with what is called here ?frame demolition?. Discourses of educational research, and particularly of ?special? versus ?inclusive? education, supply examples that are all the more telling since the very possibility of pedagogy reminds us that relativism is not an option here. To discuss interdisciplinarity and discursivity with an eye to such risks, I refer to Habermas? outlook on the position of philosophy after Kant alongside Derrida's rethinking of the right to philosophy ? a rethinking that is grounded in a reading of Kant's cosmopolitical point of view. (shrink)
Social boundaries separate us fromthem. Explaining the formation, transformation, activation, and suppression of social boundaries presents knotty problems. It helps to distinguish two sets of mechanisms: (1) those that precipitate boundary change and (2) those that constitute boundary change. Properly speaking, only the constitutive mechanisms produce the effects of boundary change as such. Precipitants of boundary change include encounter, imposition, borrowing, conversation, and incentive shift. Constitutive mechanisms include inscriptionerasure, activationdeactivation, site transfer, and relocation. Effects of (...) class='Hi'>boundary change include attackdefense sequences. These mechanisms operate over a wide range of social phenomena. Key Words: social boundary mechanisms. (shrink)
This study sought to gauge ethical attitudes about professional boundary issues of physicians and nurses in the Kingdom of Saudi Arabia. Respondents scored 10 relevant boundary vignettes as to their ethical acceptability. The group as a whole proved “aware/ ethically conservative,” but with the physicians' score falling on the “less ethically conservative” part of the spectrum compared to nurses. The degree of ethicality was more related to profession than to gender, with nurses being more “ethical” than physicians.
In the study of contextualism, the most noticeable and at the same time ambiguous problem is how to ascertain the boundaries of context. This article tries to explore the boundaries of context and the significance of the contextualizing movement which began in the 1980s. The establishment of boundaries can be analyzed from three aspects: the syntactic boundary, the semantic boundary, and the pragmatic boundary. This differentiation offers meaningful perspectives for grasping the method of contextual analysis, strengthening its (...) position and influence in scientific explanation. (shrink)
structure of a laboratory report (generalized from Italian, Chinese and US sources), we distill a fifth flavor, the givens, whose flip side is the freedoms or tangibles of an experiment. (Stated in terms of computer science, we are trying to find inputs and outputs, but these turn out to be surprisingly vague in chemistry.) Then, in the service of a white-boxing ethos (which sounds less severe than ‘anti black-boxing’), we establish a movable boundary between givens and tangibles, with implications (...) for ‘ontological attitudes’ and for the future of chemistry. Next, in revisiting a 2002 exchange between Schummer and Laszlo, which might be paraphrased as the chemist-as-philosopher versus chemist-as-artisan, we apply a second kind of sliding scale which seems to harmonize the discussion. Finally, on a possibly quixotic note, we look briefly at a third kind of sliding scale, now aimed squarely at ontology itself. For illustrative purposes, we adopt an atomocentric viewpoint (as distinct from atomistic), and assign it the provisional name ‘Fuzzy CH4 Ontology’. (shrink)
Towards the end of his 1930 paper on boundary numbers and domains of sets Zermelo briefly discusses the questions of consistency and of the existence of an unbounded sequence of strongly inaccessible cardinals, deferring a detailed discussion to a later paper which never appeared. In a report to the Emergency Community of German Science from December 1930 about investigations in progress he mentions that some of the intended extensions of these topics had been worked out and were nearly ready (...) for publication. Using manuscripts from his Nachlass, we exhibit essential features of these extensions. (shrink)
The boundary of a boundary principle in field theories is described. The difference in treatment of the principle in electrodynamics and general relativity is pointed out and reformulated in terms of underlying mathematical structure of the theories. The problem of unifying the treatment is formulated and solved. The role of E. Cartan's concept of the moment of rotation associated with the curvature of a Levi-Civita connection on a frame bundle is shown to be crucial for the unification. The (...) analysis of the boundary of a boundary principle in Kaluza-Klein theory is performed and the recipe for a unified treatment of the principle in electrodynamics and general relativity is shown to follow from the analysis. It is pointed out that the unification cand be extended to Yang-Mills fields easily. (shrink)
Physicists and philosophers argue whether quantum theory has spiritual implications. The vast majority of opinions are at two extremes: Some contend that quantum theory has absolutely no spiritual implications whatsoever, whereas others assert that it forms the very basis of a modern spirituality and can be directly applied to the human condition. It is this article's contention that neither extreme is correct. Quantum theory does have spiritual implications - a fact that its founders intuited and its enemies, Einstein preeminent among (...) them, considered prima facie evidence of its as yet undiscovered flaws. Quantum theory has proven itself against all challenges more successfully than any other scientific theory, but its spiritual implications are extremely subtle. It provides a boundary to the materialistic, deterministic worldview and shows that there must be more to reality than that, but is inherently incapable of providing evidence as to the nature of what lies beyond that boundary. (shrink)
Awareness of boundary, both physical and mental, is seen as the beginning of perception. In any account of the world, therefore, boundary must be a ubiquitous component. In sharp contrast, accounts of God within the Christian tradition commonly have proceeded by the affirmation that God is above and beyond boundary as infinite, timeless, and simple. To overcome this “problem of transcendence,” of how such a God can relate to such a world, an eight-term grammar of boundary (...) is developed to demonstrate how God as Trinity can properly be held to be without boundary yet constitute the ground of a bounded world. This leads to a way of granting theological significance to the origin and development of life. Life is seen to exist in dynamic, intentional relationships between context (“outside”) and intext (“inside”) across permeable boundaries through which an exchange of resources and information takes place for the sake of self-continuation. Comprehending life's distinctive utilization of boundary in terms of the grammar developed here enables life to be seen not only as a vestige of the Trinity but also, precisely because of this, as a sign and parable of redemption. (shrink)
This article aims to open up the biographical black box of three experts working in the boundary zone between science, policy and public debate. A biographical-narrative approach is used to analyse the roles played by the virologists Albert Osterhaus, Roel Coutinho and Jaap Goudsmit in policy and public debate. These figures were among the few leading virologists visibly active in the Netherlands during the revival of infectious diseases in the 1980s. Osterhaus and Coutinho in particular are still the key (...) figures today, as demonstrated during the outbreak of novel influenza A (H1N1). This article studies the various political and communicative challenges and dilemmas encountered by these three virologists, and discusses the way in which, strategically or not, they handled those challenges and dilemmas during the various stages of the field’s recent history. Important in this respect is their pursuit of a public role that is both effective and credible. We will conclude with a reflection on the H1N1 pandemic, and the historical and biographical ties between emerging governance arrangements and the experts involved in the development of such arrangements. (shrink)
Physicists often allow the "laws" of a discipline, formulated as partial differential equations, to be disobeyed along various surfaces, arrayed along the boundary and inside the medium under study. What kinds of considerations permit these lapses in the applicability of the equations? This paper surveys a variety of answers found in the physical literature.
The paper provides an empirical study of semiotic mechanisms of culture. We apply the methodology developed by the Tartu-Moscow School of Semiotics, building also on the criteria of boundary-work dynamics to examine a collected corpus of adverts appearing in Silesian Catholic periodicals (in Germanand in Polish) from the second half of the 19th and early 20th centuries. We discuss the cultural implications of the differences and similarities in German and Polish ads and propose functional explanations of the results in (...) terms of the notion of boundary configurations in a region as a particular structuring of cultural codes. The two analytical axes are the social boundary implicated in the use of German vs. Polish on the parameter of ‘sacred’ (sacrum) reference, and the symbolic border in the use of Fraktur (German script) versus Antiqua (Latin script) (boundary objects). (shrink)
Insects factored as ‘symbols of instinct’, necessary as a rhetorical device in the boundary work of early social psychology. They were symbolically used to draw a dividing line between humans and animals, clarifying views on instinct and consciousness. These debates were also waged to determine if social psychology was a subfield of sociology or psychology. The exchange between psychologist James Mark Baldwin and sociologist Charles Abram Ellwood exemplifies this particular aspect of boundary work. After providing a general background (...) of the debates, I turn specifically to the writings of Baldwin and Ellwood between 1890 and 1936, tracing the use of insects as ‘symbols of instinct’. (shrink)
Several interesting and important quantum field theories must contain the coupling constant in the boundary conditions. The theories considered include quantum electrodynamics of spin-1/2 fermions and gauge field theories.
AbstractIslam's Quantum Question by Nidhal Guessoum offers a sophisticated approach to reconciling the results of modern science with Islamic tradition. The book provides a valuable critique of existing literature on Islam and science and advocates the promotion of good science and science education in the Muslim world. A central tension in the book revolves around Guessoum's efforts to promote a version of theistic science, while at the same establishing a clear boundary for science and scientific methodology. Although the latter (...) works very well, the project of theistic science presented in the book is, at the very least, contentious. However, Islam's Quantum Question is a milestone in the literature on Islam and science and should be valuable for anyone interested in the search for meaning in both science and religion. (shrink)
This article reports on considerable variety and diversity among discourses on their own jobs of boundary workers of several major Dutch institutes for science-based policy advice. Except for enlightenment, all types of boundary arrangements/work in the Wittrock-typology (Social knowledge and public policy: eight models of interaction. In: Wagner P (ed) Social sciences and modern states: national experiences and theoretical crossroads. Cambridge University Press, Cambridge, 1991) do occur. âDivergersâ experience a gap between science and politics/policymaking; and it is (...) their self-evident task to act as a bridge. They spread over four discourses: ârational facilitatorsâ, âknowledge brokersâ, âmegapolicy strategistsâ, and âpolicy analystsâ. Others aspire to âconvergenceâ; they believe science and politics ought to be natural allies in preparing collective decisions. But âpolicy advisorsâ excepted, âpostnormalistsâ and âdeliberative proceduralistsâ find this very hard to achieve. (shrink)
Interfacial energy is a fundamental physiochemical property of any multi-phase system. Among the most direct approaches for determining solid?liquid interfacial energy is a technique based on measuring the shape of grain boundary grooves in specimens subjected to a linear temperature gradient. This technique was adapted to crystallizing colloids in a gravitational field. Such colloids exhibit a freezing?melting phase transition and are important not only as self-assembling precursors to photonic crystals, but also as physical models of atomic and molecular systems. (...) The grain boundary groove technique was tested using suspensions of sterically stabilized poly(methyl methacrylate) spheres, which have been shown to closely approximate the hard sphere potential. Whereas isotropic models did not fit grain boundary groove data well, the capillary vector model, which is suitable for both isotropic and anisotropic surface energies, produced ?110?=?0.58?±?0.05 k B T/σ2. This value of interfacial energy is in agreement with many of the published values for hard spheres, supporting the validity of our grain boundary groove technique adaptations to colloidal systems in a gravitational field. Finally, kinks observed in groove profiles suggest a minimum anisotropy parameter of ε?=?0.029 for hard spheres. (shrink)
I address the question: “What is fixed on the boundary in the action principles of general relativity?” Four forms of the action are considered: the Einstein action, the Hilbert action, the first order action, and what may be called the cosmological action. The relationships and boundary data of these actions are described geometrically. Formal passage to the “Euclidean” forms of these actions is effected in detail.
The thesis of this paper, that the contemporary Catholic philosopher needs to be critical in an expanded Kantian sense of the boundary of reason, while still maintaining a strict biblical and Christian faith, is developed in four parts. First, the nature of a Catholic philosophical pluralistic community will be explored. In keeping with this pluralism, a first sense of boundary as that between philosophical reason and Christian faith will be considered. Then, a second sense of boundary as (...) the Kantian context of critical philosophy in which reason sets the limit on the human claims to objective knowledge will be considered. A twofold expansion of this Kantian sense of the boundary-limit of reason is seen to be necessary. Finally, part four focuses on the place of Catholic faith for such a philosopher, suggests ways to overcome certain extremes, and proposes a possible path for thinking the Transcendent. (shrink)
Internal stresses generated on subjecting cylindrical copper/tungsten composites to thermal cycling were relieved by slip and grain boundary cavitation and sliding; the last two occurring at high temperatures. Microstructural evidence indicated that voids were nucleated by clustering of the excess vacancies, produced by the quenching treatment and plastic deformation, on grain boundaries transverse to the radius. Tensile radial stress acting across these transverse boundaries during the heating part of the cycle was thought to aid in nucleation of these pores. (...) The number and size of voids increased with cycling. Eventually the voids linked up and grain boundary sliding occurred in these weakened boundaries. Nabarro-Herring stress-assisted diffusion, under the action of tensile radial stress, appeared to be responsible for the void growth. Circumferential stress was thought to be responsible for the sliding movement. (shrink)
Central to Kierkegaard’s account of religious existence is his critique of speculative reason. This critique begins with the distinction between subjective and objective reflection. Its most radical aspects appear in Kierkegaard’s discussions of the paradox. In spite of Kierkegaard’s frequent comments on this notion, it is not readily understood. I want to argue against a common reading of this notion and propose an alternative reading. This alternative reading allows for a conceptually quite plausible account of the manner in which the (...) paradox presents reason with a boundary, in virtue of its relation to objective reflection and to subjective reflection as well. Because of this boundary, reason points beyond its own achievements to a domain of contemplation and appropriation. This is a domain that reason itself identifies in connection with the paradox. It both surpasses rational achievements and integrates them into itself. (shrink)
Segregation of alloying and impurity elements to grain boundaries in ferritic steels and alloys is known to modify the mechanical properties. This paper considers segregation of such elements, in particular phosphorus and carbon, that occur in ferritic nuclear pressure vessel steels subject to neutron irradiation and temperature typical of that encountered in service. Models are presented that allow the prediction of equilibrium and non-equilibrium segregation of phosphorus to grain boundaries and also take into account synergistic interaction with carbon under various (...) combinations of neutron-irradiation temperature. These are related to a wide range of experimental observations compiled from data in the literature for mainly phosphorus and carbon measured at grain boundaries in neutron-irradiated ferritic vessel steels and alloys. The predictions from the segregation models are compared with these experimental data. The discussion provides a rationalization for the apparent variability in the measured grain boundary phosphorus compositions and thereby fracture susceptibility for various nuclear pressure vessel ferritic steels. (shrink)
It is argued that organ donation from a patient to the patient's physician is ethically dubious because donation decisions will be inappropriately influenced and the negative public perceptions will result in more harm than good. It is suggested that to protect the perception of the physician–patient relationship, avoid cynicism about medicine’s attitude to patient welfare and maintain trust in the medical profession, a new professional boundary should be established to prevent physicians from receiving organs for transplantation donated by their (...) patients. (shrink)