45,783 research outputs found
D. G. Kerr 157696
No full textThe "D. G. Kerr" was built at Superior, Wisconsin in 1903 by the Superior Ship Building Company. She was built for the Provident Steamship Company of Duluth, Minnesota who owned her until 1916. That year, she was sold to the Interlake Steamship Company of Cleveland, Ohio. Her name was changed to "Harry R. Jones." In 1955, she was owned by the Cargo Carriers, Inc. of Cleveland, Ohio. The following year, she became the property of Ferrotar Corporation of Wilmington, Delaware. She was towed out the Seaway by the "James Battle" and the "Helen McAllister. Her towline broke and she grounded off Ardrossan, Scotland. She was released at Troon, Scotland where she was scrapped
Arithmetic of degenerating principal variations of Hodge structure: Examples arising from mirror symmetry and middle convolution
No full textWe collect evidence in support of a conjecture of Griffiths, Green, and Kerr on the arithmetic of extension classes of limiting mixed Hodge structures arising from semistable degenerations over a number field. After briefly summarizing how a result of Iritani implies this conjecture for a collection of hypergeometric Calabi-Yau threefold examples studied by Doran and Morgan, the authors investigate a sequence of (non-hypergeometric) examples in dimensions 1 ≤ d ≤ 6 arising from Katz's theory of the middle convolution. A crucial role is played by the Mumford-Tate group (which is G2) of the family of 6-folds, and the theory of boundary components of Mumford-Tate domains
Magneto–Optical Kerr Effect Microscopy Investigation on Permalloy Nanostructures
No full textThis thesis focuses on the investigation of magnetic domains in ultrasmall permalloy (Ni80Fe20) structures down to nanometre size. Magnetic domains and domain walls in nano objects are often observed using a very high resolution and high power microscope such as magnetic soft x-ray microscope, magnetic force microscopy imaging and photoemission electron microscopy. A reason for this is because the Kerr signal in nanostructures is very weak. However the results from this thesis demonstrate that magnetic domains in permalloy magnetic nanostructures can still be observed with very good contrast using a Magneto-optical Kerr effect (MOKE) microscope. The constructed Kerr microscope is a home-build wide field microscope and is able to produce magnetic domains image of permalloy nanowire as small as 245 nm, although the resolution limit of the microscope is 505 nm. For the first time, a magnetic domain in nanowire with width of 245 nm is observed using a wide-field microscope. The combination of hysteresis loops and magnetic domains observations for studying a magnetic sample provides a three-dimensional understanding of the magnetic characteristic of the sample. This is crucial in investigating nano samples as the theoretical arguments with the experimental results are always constrained by the experimental part. Three kinds of nanostructure sample were observed using the Kerr microscope; a cross nanowire, zigzag nanowire and a nanowire with notch and a nucleation pad at one end. It was found that a cross nanowire can form magnetic domains upon reversal and the junction forms a magnetisation vortex. Findings from zigzag nanowire demonstrate a complex, multiple magnetic domains formation upon magnetisation reversal. A weak domain wall pinning effect was observed in the nanowire, causing a multiple domains formation in the nanowire upon reversal. It can be confirmed that this effect was caused by the high coercivity of the nucleation pad. For the nanowire with notch, it was demonstrated that the coercivities were different at negative and positive field. But for such case, there is a relationship observed between the percentage notch depth and the coercivity at the junction
The modern urban in the journalistic prose of Théophile Gautier : ‘Crayonnons à la hâte…’.
No full textThe chapter forms part of a volume entitled Aesthetics of Dislocation in French and Francophone Literature and Art: Strategies of Representation, published by Edwin Mellen Press in 2009, co-edited with two other colleagues, Dr Daisy Connon and Dr Gillian Jein. This chapter is concerned with a new articulation of poetic discourse in the writings of the nineteenth-century French poet and journalist Théophile Gautier. Through analysis of his profuse feuilletons, travel writings and art criticism, this chapter argues that Gautier’s prose exhibits and acute perception of the facts determining its construction as text and dramatizes these as a means to explore a range of complex objects of representation which are encountered throughout the topography of the modern urban; the latter include train stations, ports and the Universal Exhibition halls. Taken together, these texts identify the shifting urban environment as a source of poetic renewal. In so doing, they reveal a dramatically more comprehensive and dynamic vision than is permitted by the narrowly aestheticist views by which Gautier’s work is normally characterized
Surgical workload from an integrated UK field hospital during the 2003 Gulf conflict
No full textAIMS: This paper reports the surgical experience of a UK reserve field surgical hospital during military operations in Iraq during March and April 2003. Particular reference is given to the integration of the surgical specialities, consultant led and multidisciplinary teamworking in the treatment of military and civilian casualties from all sources and of all causes. METHODS All surgical workload data was collected prospectively for the warfighting (Phase One) and specialist referral (Phase Two) phases of the operation. Standard military and Red Cross protocols were used for all injuries and microbiology studies were undertaken for penetrating ballistic injuries. Operations were classified by anatomical region; upper or lower limb; head and neck; thoracic; abdominal, including genitourinary; ophthalmic; and burns, and by whether they were primary; secondary planned or secondary unplanned. RESULTS: A wide range of patterns of wounding arising from combat and non-combat related military and civilian trauma and burns were seen and treated. 323 operations were performed. There were 116 operations in phase one and 207 operations in phase two. There were 160 primary procedures (new patients), 146 secondary planned and 17 unplanned procedures (range one to eight procedures per patient). Close integration of general, orthopaedic, plastic, maxillofacial, ophthalmic and neurological surgeons and general and ITU anaesthetists allowed the delivery of a range of specialist treatment to a heterogenous patient population, including children as young as 6 months and a lady in the advanced stages of pregnancy. CONCLUSIONS: Patterns of wounding in casualties surviving to reach specialist field hospital care were similar to those reported in other high intensity conflicts. A consultant led, multidisciplinary approach with field intensive care facilities allowed combined, staged and safe surgery for complex, multi-organ and multi-limb trauma in an austere environment.</p
Geodesic Geometry of Black Holes
No full textThe study of geodesics is of intrinsic significance in the study of the geometry of space-time. In this thesis null, space-like and
time-like geodesics are studied in the case of the space-times of Schwarzschild, Reissner-Nordstrouml;m and Kerr black holes. These
space-times have been investigated with varying degrees of thoroughness in many articles and some books. However, there are some significant gaps in these treatments and the central aim of this thesis is to fill these gaps where necessary. Moreover, the following topics are covered for the first time.
1. In Chapter 4 a thorough treatment of the space-like geodesics of the Schwarzschild solutions has been given. These geodesics are the trajectories of Tachyons (faster than light particles) and are
treated in a complete manner. This has been done by obtaining exact solutions and solving them numerically.
2. In Part II all solutions for geodesics for a
Reissner-Nordstrouml;m black hole have been given in complete detail, i.e. time-like, null and space-like geodesics and orbit of a charged particle.
3. In Chapter 14 all solutions for geodesics in the equatorial plane of a Kerr black hole have been given in complete detail, i.e. time-like, null and space-like geodesics.
4. The study of special types of non-equatorial geodesics for a Kerr black hole have been given in complete detail, i.e. time-like (Chapter 17), null (Chapter 15) and space-like (Chapter 16). This has been done in order to distinguish the qualitatively different types of solutions.
Calculation of the explicit formulas, which describe these geodesics, as well as numerically computed diagrams representing the geodesics have been incorporated in these studies. The following subjects have been also treated:
5. Solutions for the geodesics in Reissner-Nordstrouml;m black holes with |Q_*| gt;= M, which are black holes with one (|Q_*| = M) or no horizon (|Q_*|gt; M) (Chapter 8).
6. Solutions of geodesics in extreme and fast Kerr black holes, i.e. black holes with a = M (extreme) and a gt; M (fast). As in the case of |Q_*| gt; M, fast black holes have naked singularities (Chapter 14).
7. Some general observations about orbit types of the Kerr black holes regarding relationships between parameters such as angular momentum, energy, Carter constant and mass and angular momentum of black holes (Chapter 13).
8. Some corrections to errors found in the literature.
While it has not been possible to cover all different cases which occur for possible relations amongst the parameters specifying a
general black hole, interesting geodesics have, however, been studied and a more thorough presentation of the properties of geodesics has now been given
Exact solution of Kerr black hole perturbations via CFT2 and instanton counting: Greybody factor, quasinormal modes, and Love numbers
No full textWe give explicit expressions for the finite frequency greybody factor, quasinormal modes, and Love numbers of Kerr black holes by computing the exact connection coefficients of the radial and angular parts of the Teukolsky equation. This is obtained by solving the connection problem of the confluent Heun equation in terms of the explicit expression of irregular Virasoro conformal blocks as sums over partitions via the Alday, Gaiotto, and Tachikawa correspondence. In the relevant approximation limits our results are in agreement with existing literature. The method we use can be extended to solve the linearized Einstein equation in other interesting gravitational backgrounds
Long-Standing oral ulcers: proposal for a new S-C-D classification system'
No full textPersistent oral ulcers and erosions can be the final common manifestation, sometimes clinically indistinguishable, of a diverse spectrum of conditions ranging from traumatic lesions, infectious diseases, systemic and local immune-mediated lesions up to neoplasms. The process of making correct diagnosis for persistent oral ulcers still represents a challenge to clinicians. Major diagnostic criteria should include the clinical appearance of both ulcer and surrounding non-ulcerated mucosa, together with the evaluation of associated signs and symptoms, such as: number (single or multiple), shape, severity of the ulcer(s), conditions of remaining mucosa (white, red or with vesiculo-bullous lesions) and systemic involvement (e.g. fever, lymphadenopathy or evaluation of haematological changes). The aim of this paper was to review the literature relating to persistent oral ulcers and provide a helpful, clinical-based diagnostic tool for recognising long-standing ulcers in clinical dental practice. The authors, therefore, suggest distinguishing simple, complex and destroying (S-C-D system) ulcerations, as each requires different diagnostic evaluations and management. This classification has arisen from studying the current English literature relating to this topic, performed using MEDLINE / PubMed / Ovid databases
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