683 research outputs found
Heavy Quark Symmetry Predictions for Weakly Bound B-Meson Molecules
Recently the Belle collaboration discovered two resonances, Zb(10610) and
Zb(10650), that lie very close to the B\bar{B}^* and B^*\bar{B}^* thresholds,
respectively. It is natural to suppose that these are molecular states of
bottom and anti-bottom mesons. Under this assumption, we introduce an effective
field theory for the Zb(10610) and Zb(10650), as well as similar unobserved
states that are expected on the basis of heavy quark spin symmetry. The
molecules are assumed to arise from short-range interactions that respect heavy
quark spin symmetry. We use the theory to calculate line shapes in the vicinity
of B^{(*)}\bar{B}^{(*)} thresholds as well as two-body decay rates of the new
bottom meson bound states. We derive new heavy quark spin symmetry predictions
for the parameters appearing in the line shapes as well as the total and
partial widths of the states.Comment: 17 pages, 2 figure
George Berkeley\u27s idealism: an examination of the idealist metaphysics and its connection to philosophy of mind
The prominent 18th century empirical philosopher George Berkeley espoused a philosophy known as âidealism.â This thesis aims to show that George Berkeleyâs idealism is a formidable player in philosophy of mind. The present research unfolds his arguments for idealism as they appear in A Treatise Concerning the Principles of Human Knowledge, turning at several points to The Three Dialogues between Hylas and Philonous for clarification. This research further explores the fundamentals of idealism in light of philosophy of mind, highlighting idealismâs intrinsic connection to this discipline. While this work is far from exhaustive, it provides the reader with essential information on Berkeleyâs idealism and proves its worth as a philosophy in todayâs world
THE PERSONAL AND SOCIAL CONTEXT OF JUSTINIANIC RELIGIOUS POLICY PRIOR TO THE THREE CHAPTERS CONTROVERSY
The emperor Justinian\u27s religious policy has sometimes been characterized as haphazard or incoherent. This dissertation examines religious policy in the Roman Empire from the accession of the emperor Justin to the inception of the Three Chapters controversy in the mid 540\u27s AD. It considers the resolution of the Acacian Schism, Justinian\u27s apparent ambivalence with regard to the Theopaschite formula, the attempt to court the anti-Chalcedonians in Constantinople in the period leading up to the Council of 536, and the relationship between the genesis of the Three Chapters and Second Origenist controversies.
Even during these seemingly disparate episodes, this dissertation argues that it is possible to account for the apparent incoherence of this period. To do so, we create an account which includes and appreciates the embeddedness of imperial policy within a social context with two key features. First, we must bear in mind the shifting interests and information available to the individual agents through and over whom the emperor hoped to project influence. Second, we must identify the shifting and hardening symbolic and social boundaries established through the interactions of these same, competing agents. These form the basis for in- and out-group categorization. The individual interests of individual peopleâwhether Justinian, Vitalian, Dioscorus, Leontius, Eusebius, Theodore Askidas, or Pelagiusâwithin complex networks must always be accounted for to give a complete picture. When this social context is accounted for, Justinian\u27s approach appears as that of a rational actor, having incomplete information, with consistent policy goals, working within inconsistent constraints to achieve those goals
Measuring monopole and dipole polarizability of acoustic meta-atoms
We present a method to extract monopole and dipole polarizability from
experimental measurements of two-dimensional acoustic meta-atoms. In contrast
to extraction from numerical results, this enables all second-order effects and
uncertainties in material properties to be accounted for. We apply the
technique to 3D-printed labyrinthine meta-atoms of a variety of geometries. We
show that the polarizability of structures with shorter acoustic path length
agrees well with numerical results. However, those with longer path lengths
suffer strong additional damping, which we attribute to the strong viscous and
thermal losses in narrow channels
The Aesthetics of Impersonation and Depersonalization: Samuel Beckett and Philip Roth
This essay begins by considering an obvious point of difference between the work of Samuel Beckett and Philip Roth. In view of its tendency to present anonymous voices and body parts, Beckettâs writing is frequently seen to explore the erosion of personhood. Rothâs concern with the secret lives of his characters, by contrast, means that he is often considered to be more concerned with impersonation than depersonalization. While accepting the general validity of this view, the essay complicates it. Through readings of works such as The Breast, Sabbathâs Theater, The Humbling, Molloy, and Not I, it argues that a close comparison of the two writers can reveal the central role that depersonalization plays in Rothâs writing and also the stubbornness of personhood in Beckettâs
Gertrude Stein, Samuel Beckett and the Aesthetics of Inattention
Drawing on the ideas of Jonathan Crary, this article positions Gertrude Stein and Beckett as part of a wider investigation of inattention in twentieth-century culture. Considering first the psychological experiments of Stein, and then Beckettâs theatre of the 1970s, the article argues for the importance to literary modernism of language that is not perceived, or only dimly perceived, and exists on the fringes and peripheries of a perceptual field
Perception, Attention, Imagery: Samuel Beckett and the Psychological Experiment
Samuel Beckett is often thought of as an experimental writer but little critical attention has been paid to the question of what the term âexperimentalâ means when applied to Beckettâs work (and arguably literature in general). One might suggest that to call Beckett an experimental writer is to identify him as a member of the avant-garde, placing his writing in opposition to more commercially-orientated, âmainstreamâ works of literature. Alternatively, the term might be taken to highlight Beckettâs formal innovations â his capacity to change conceptions of what literature is and does. This study, though, will specify another way in which we might understand Beckettâs writing to be experimental. Drawing on Beckettâs engagement with experimental and therapeutic psychology, the study suggests that Beckettâs works might be seen as experiments in a more scientific sense. Through readings of his later works for page, stage and screen, the chapters of this study suggest that Beckettâs writing can contribute to our knowledge of psychological concepts such as perception, attention and mental imagery. Beckettâs works, I argue, might be defined as experimental insofar as they position and stimulate human bodies in ways that allow us to better understand our complex, but partial, experiences of the world
Degradation by Free Chlorine of Aromatic Polyamide Active Layers of Thin-Film Composite Membranes
Polyamide-based thin-film composite membranes are the current technology of choice to meet the growing demand for drinking water desalination applications. One significant drawback to the use of this class of membranes is the high sensitivity of their polyamide active layer to oxidation by free chlorine. The current understanding of the mechanisms of chlorine uptake and eventual polymer degradation that lead to membrane failure has been gained mostly through the quantitative study of the effects of chlorination on molecular model polyamide compounds and membrane surfaces (top~5nm) with X-ray photoelectron spectroscopy (XPS), as well as through qualitative analyses of chlorinated membrane samples with attenuated total reflectance-Fourier transformed infrared (ATR-FTIR)spectroscopy. The physico-chemical changes induced by chlorination within the bulk of the active layer, however, have not been characterized by means other than ATR-FTIR, and therefore it has not been confirmed in the literature that the physico-chemical changes observed at the membrane surface are representative of the volume-averaged changes in the active layer, and that the mechanisms that have been proposed as leading to membrane failure based on studies with model compounds are consistent with observations for the bulk region of the active layer. Accordingly, we exposed a polyamide thin-film composite membrane to free chlorine at a range of concentrations, exposure times and pH values and quantified in situ the volume-averaged kinetics of chlorine uptake and resulting de-polymerization of the polyamide active layer. We performed volume-averaged measurements for the membrane active layer using Rutherford Backscattering Spectrometry (RBS) as an analytical technique. Our results indicate that the trends observed for the kinetics of chlorine uptake into the bulk region of the active layer are mostly consistent with the corresponding trends reported in the literature for chlorine uptake into the active layer surface. Our results also show that consistent with mechanisms proposed in the literature based on studies with model compounds, chlorine uptake into the bulk region of the active layer can be explained by chlorination of the amidic nitrogen by hypochlorous acid at all pH conditions and ring chlorination. Analysis of chlorine uptake results at acidic conditions indicates that ring chlorination occurs by Orton rearrangement, not direct ring chlorination. We also provide the first measurements of the kinetics of chain scissioning in the active layer as a result of exposure to free chlorine. Our results indicate that de-polymerization of the active layer occurs when the membrane is exposed to alkaline conditions following or during chlorination of the amidic nitrogen. Chain scission of the amide linkage also occurs via a hydrolysis mechanism as is dependent on both exposure to hypochlorous acid and hydroxyl ion. By contrast, ring chlorination does not result in polyamide de-polymerization. KeyWords: reverse osmosis, nanofiltration, polyamide, free chlorine, chain scissioning, ion probing, RBS, charge density, amide N-Cl, ring chlorination.Master of Science in Environmental Engineerin
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