36 research outputs found
Formation of silicon nanodots via ion beam sputtering of ultrathin gold thin film coatings on Si
No full textIon beam sputtering of ultrathin film Au coatings used as a physical catalyst for self-organization of Si nanostructures has been achieved by tuning the incident particle energy. This approach holds promise as a scalable nanomanufacturing parallel processing alternative to candidate nanolithography techniques. Structures of 11- to 14-nm Si nanodots are formed with normal incidence low-energy Ar ions of 200 eV and fluences above 2 x 10(17) cm(-2). In situ surface characterization during ion irradiation elucidates early stage ion mixing migration mechanism for nanodot self-organization. In particular, the evolution from gold film islands to the formation of ion-induced metastable gold silicide followed by pure Si nanodots formed with no need for impurity seeding
The place of experimental tasks in geometry teaching: learning from the textbook designs of the early 20th century
No full textThe dual nature of geometry, in that it is a theoretical domain and an area of practical experience, presents mathematics teachers with opportunities and dilemmas. Opportunities exist to link theory with the everyday knowledge of pupils but the dilemmas are that learners very often find the dual nature of geometry a chasm that is very difficult to bridge. With research continuing to focus on understanding the nature of this problem, with a view to developing better pedagogical techniques, this paper examines the place of experimental tasks in the process of learning geometry. In particular, the paper provides some results from an analysis of innovative geometry textbooks designed in the early part of the 20th Century, a time when significant efforts were being made to improve the teaching and learning of geometry. The analysis suggests that experimental tasks have a vital role to play and that a potent tool for informing the design of such tasks, so that they build effectively on pupils’ geometrical intuition, is the notion of the geometrical eye, a term coined by Charles Godfrey in 1910 as “the power of seeing geometrical properties detach themselves from a figure"
High-energy X-ray diffraction and topography investigation of CdZnTe
No full textThe crystal quality of CdZnTe (CZT) was investigated by using high-energy transmission x-ray diffraction techniques. CdZnTe had shown excellent performance in hard hard x-ray and gamma detection. Collimated high-energy x-rays, produced by a superconducting wiggler at the National Synchrotron Light Source's X17B1 beamline, allow for a nondestructive characterization of thick CZT samples. The study lead to understanding the effects of defects on the device performances and ultimately to improving the quality CZT material required for device fabrication
Nora, Nora : a novel
No full textPeyton is not ready to share her widowed father with anyone, let alone a barely remembered cousin who just rolled into town. However, her father seems to like Nora well enough, and prim Aunt Augusta hates her, which raises Nora slightly in Peyton's esteem. Maybe Nora is just what quiet Lytton, Georgia needs this summer. The whole household is revitalized by Nora's energy, and it looks like she might stay on forever. But soon it becomes clear that something is troubling Nora deeply. It has to be something from her past that's bothering her, something she is running away from. When the shocking truth comes to light, it stuns the residents of their small segregated town. It also teaches Peyton the enormous cost of loving -- and the necessity of doing it anyway. New York Times bestselling author Anne Rivers Siddons has created a quirky, wildly likeable, and truly unforgettable heroine. Nora, Nora is a wonderful novel, written with insight and a keen sense of time and place. It is destined to be Anne Rivers Siddons's biggest hit yet
William Wallace: or, the Highland hero [electronic resource] : A tale, founded on historical facts. By Henry Siddons, Author of Modern Breakfast. In two volumes.
No full textElectronic reproduction.English Short Title Catalog,Reproduction of original from British Library
Simultaneous measurements of the real and imaginary parts of the X-ray anomalous dispersion using X-ray inferometers
No full text
Shakespeare and England's Empire, 1780-1800.
No full textThis thesis is a study of Shakespeare and imperialism in England between 1780 and 1800. Chapters investigate landscape art and empire in the Boydell gallery, death and imperial subjectivity, gender and form in appropriations of Shakespeare by women artists and writers, caricatures that reference Shakespeare during these years, the use made of Shakespeare by prominent individuals to formulate their identities in the context of empire and the debates on the Quebec Bill in London’s parliament in May 1791. The thesis is primarily concerned to explore how gothic forms and representations were integrated into the history of Britain’s relationship to its empire; to assess the use of Shakespeare in academy painting and in forms such as engraving, graphic satire, relief sculpture and in writing. The study also emphasises affect: fear of imperial identities, the danger of overseas life, terror, nostalgia, affection in connection to the nation and its spaces, the increasingly imperial reach of relations with revolutionary France during these years, and pleasurable diversion in reappropriations of the plays in varying arenas
Design, simulation and testing of large area silicon drift detectors and detector array for X-ray spectroscopy
No full textLarge area (25 mm(2)) silicon drift detectors and detector arrays (5x5) have been designed, simulated, and fabricated for X-ray spectroscopy. On the anode side, the hexagonal drift detector was designed with self-biasing spiral cathode rings (p(+)) of fixed resistance between rings and with a grounded guard anode to separate surface current from the anode current. Two designs have been used for the P-side: symmetric self-biasing spiral cathode rings (p(+)) and a uniform backside p(+) implant. Only 3 to 5 electrodes are needed to bias the detector plus an anode for signal collection. With graded electrical potential, a sub-nanoamper anode current, and a very small anode capacitance, an initial FWHM of 1.3 keV, without optimization of all parameters, has been obtained for 5.9 keV Fe-55 X-ray at RT using a uniform backside detector
The process of re-designing the geometry curriculum: the case of the Mathematical Association in England in the early twentieth century
No full textThis paper examines a key period of change in geometry teaching in England. Our focus is the character and nature of the recommendations of the 1902 geometry report of the UK Mathematical Association. We analyse historical documents of the Mathematical Association using a theoretical framework informed by work in the sociology of education. Our analysis shows that the character and recommendations of the Mathematical Association report were influenced by various factors including: that Mathematical Association members at the time still respected the traditional Euclidean approach to geometry as a basis for school geometry; that the academic and ‘power’ resources available to the Mathematical Association at the time were not sufficient to enable a complete change from the traditional approach; that a lack of consensus between the various members of the Mathematical Association prevented a more radical proposal; and that the general climate in schools at that time was not prepared for far-reaching changes to the teaching of geometry. These findings accord with other research on educational reform which indicates that curriculum change processes are invariably complex and often subject to much politicking
