Surface engineering through low temperature deposition of wear resistant layers by reactive magnetron sputter ion plating

The aim of this investigation was the deposition of hard» wear resistant titanium nitride (TiN) thin films, produced from a reactive magnetron sputter ion plating device, at high deposition rates and low substrate temperatures. An allied objective vas the understanding and development of experimental methods which would permit the deposition of titanium nitride-type layers on plastic. The early part of the work deals with the formation of TiN layers on high speed steel, at 500°C deposition temperature Modifications in equipment design and deposition procedures aided the formation of adherent TiN layers. The routine deposition of stoichiometric titanium nitride vas facilitated by a control feedback network The use of graded interfaces between the film and the substrate improved adhesion. Total gas pressure and the level of substrate bias affect film hardness and wear resistance. The next stage of the development process vas the deposition of TiN at approximately 250°C substrate temperature. The main source of substrate heating, in the case of an indirectly cooled magnetron, was identified as the heat liberated from the target. The use of a directly cooled magnetron configuration resulted in lover substrate temperatures. With this device, TiN films vere formed on high speed steel at high deposition rates and with good adhesion. The increased ion current to the substrate is, tentatively, attributed to an extended plasma region associated with the directly cooled configuration Metastable T^N phases are formed from the combination of high deposition rates, low substrate temperatures (250°C) and increased ion bombardment to the substrate. These TiN films, however, are softer and less wear resistant than those produced at 500°C. The final part of the investigation centred around the deposition of TiN type layers onto plastic T1 -T1 N and AI-T1 -T1N layered structures were deposited onto polycarbonate plastic at 100°C. An experimental design approach was employed to develop adhering coatings. A slight partial pressure of oxygen during the initial Ti deposition improves film adhesion. The use of the aluminium interface improves film reflectivity, cosmetic appearance and adhesion. This aluminium interface makes the multilayer structure more susceptible to physical and chemical attack. The wear resistance of the coated plastic is 2 to 4 times greater than the base plastic material

Graviton Production in Relativistic Heavy-Ion Collisions

We study the feasibility of producing the graviton of the novel Kaluza-Klein theory in which there are d large compact dimensions in addition to the 4 dimensions of Minkowski spacetime. We calculate the cross section for producing such a graviton in nucleus-nucleus collisions via t-channel photon-photon fusion using the semiclassical Weizsacker-Williams method and show that it can exceed the cross section for graviton production in electron-positron scattering by several orders of magnitude.Comment: 10 pages, 3 figures, accepted for publication in Physical Review

Aggregation Services and Songwriter Independence

Digital download aggregation services are the modern songwriter’s greatest ally and independent record labels’ newest competition. Digital download aggregators like CDBaby, Distrokid, Tunecore, and Awal have made releasing an album for online distribution far easier than before. Many aggregators are affordable and also provide many services to the songwriter that historically involved employing additional middlemen. Like distribution, the mastering stage of production has evolved. Mastering music can now be done through online services independently and on a very tight budget. Automated mastering services like LANDR and iZotope will be briefly discussed in section three, as well as additional options for the modern artist. These services illustrate a portion of the online network of music production, which can offer a replacement for the historic record label model. Historically, terms like ‘A&R scout’ were used to describe those who seek local talent and offer them a contract. This contract was often manipulative and included many obligations. A distributor, engineer, and manager were usually partnered with the musicians and were often compensated with more security than the songwriter. A modern musician hoping to distribute their work to streaming services online now has more freedom to release their work without manipulative, obligatory contracts. It is more cost effective than ever to record, mix, and distribute; and the competition online has increased as a result

The American Law of Strikes and Boycotts

Presented for the Degree of Bachelor of Laws

Characterisation of CD4+CD25+ T cells in regulatory responses to allergens

Imperial Users onl

Dynamic Equine Laryngeal Prosthesis

The respiratory system of horses is the major limiting factor for athletic performance. As such, any respiratory impairment can have a considerable effect on athletic performance. A common site for this impairment to occur is the upper respiratory tract with laryngeal collapse being the most common form in horses. The recurrent laryngeal nerves in the horse are the longest nerves in the body and prone to degenerative axonopathy. This is termed recurrent laryngeal neuropathy (RLN) and results in neurogenic atrophy of the cricoarytenoideus dorsalis (CAD) muscle. Loss of function of the CAD leads to dynamic laryngeal collapse when exposed to the negative airway pressures produced during exercise. As a result, RLN is a common cause of reduced athletic performance in horses. Currently the most commonly performed treatment for RLN in horses is a static prosthetic laryngoplasty. This procedure has a relatively poor success rate in performance horses (ranging from 50-70%) and high complication rate of between 26-43%.1-4 Two of the major complications are dysphagia and loss of abduction. In general, many of the complications can be attributed to either under or over abduction of the arytenoid and static laryngoplastic fixation. The objective of the research reported here was to develop a laryngoplasty system that allowed for alteration of the degree of arytenoid abduction post-operatively. This thesis outlines the successful development of such a device. Initially, the existing standard laryngoplasty procedure was examined mechanically and a variety of prototypes were developed and evaluated. Subsequently, we selected the final dynamic laryngoplasty system (DLPS) for further evaluation. After optimising the position of attachment to the arytenoid using an anchor, the prototype device was mechanically tested under static loading, cyclic and ramp (single linear loading) to failure conditions. This study found the device was able to cause effective shortening of a suture loop with minimal cyclical loss and was able to resist ramp testing sufficiently to justify further evaluation. Additional in vitro testing was performed using cadaveric larynges and demonstrated that the DLPS was able to cause effective increases in arytenoid abduction within the confines of equine laryngeal anatomy. The final in vitro study tested the ability of the DLPS to achieve and maintain arytenoid abduction during testing using a static airflow model with a flow rate of 55L/sec which was consistent with previously published research. After completion of the in vitro studies an in vivo proof of concept study was performed. This demonstrated that the device could be effectively delivered via a standing procedure under sedation and allowed for selective alteration in arytenoid abduction at 7 days post-operatively.Thesis (Ph.D.) -- University of Adelaide, School of Animal and Veterinary Sciences, 201

Structure, Dynamics, and Photophysics in the Copper(I) Iodide–Tetrahydrothiophene System

Combination of CuI and tetrahydrothiophene (THT) in MeCN or neat THT produces various phases, depending upon experimental conditions. Green luminescent product (CuI)4(THT)2 (1) consists of Cu4I4 cubane units knit into a 3-D network by μ2-THT ligands. Dull yellow luminescent (CuI)10(THT)7(MeCN) (2) contains {[Cu4I4(THT)](μ2-THT)2(Cu2I2)(μ2-THT)2[Cu4I4(NCMe)]} “rungs” linked into 1-D ladders by pairs of μ2-THT ligands. Two molecular (CuI)4(THT)4 phases were found: orange luminescent 3a and yellow luminescent 3b. Triclinic 3b is the more stable phase at 25 °C, but it undergoes endothermic transformation to monoclinic 3a at 38 °C. Compound 3a transforms to a triclinic phase (3a′) that retains orange emission at −60 °C. Nonemissive (CuI)3(THT)3·MeCN (4) is a 2-D sheet structure in which Cu3(THT)3 rings are linked in trigonal directions by rhomboid Cu2I2 dimer units. The previously reported (CuI)2(THT)4 (5) is a molecular dimer. Temperature and mixing ratio domains for the formation of the CuI–THT phases from MeCN are presented. Luminescence in 1, 2, 3a, and 3b is rationalized on the basis of varying degrees of halide-to-metal charge transfer (XMCT) and metal-centered (MC) behavior. Low-temperature spectra reveal reversible changes, including modest red shifts for 1 and 2, and splitting into two excitation/emission band pairs for 3a and 3b