Reliable irogane alloys and niiro patination—further study of production and application to jewelry

Japanese metalworkers use a wide range of irogane alloys (shakudo, shibuichi), which are colored with a single patination solution (niiro eki). This approach allows different alloys to be combined in one piece and patinated, producing a multi-colored piece of metalwork. At present the niiro patination process is unreliable. In this study we develop a deeper understanding of the effect of patination solution ingredients on color. We have tested a synthetic niiro solution, comparing the color results with traditional niiro solution patination. Surface products have been analyzed to determine how they are influenced by both the niiro solution and cleaning procedures during patination. A large range of shibuichi and shakudo alloys have been produced to determine the full color pallette. This work also explores the use of alternative processes for the patination of irogane alloys, examining the effect of laser marking and anodizing on irogane alloys

Japanese irogane alloys and patination – a study of production and application

Japanese metalworkers use a wide range of irogane alloys (shakudo, shibuichi), which are colored with a single patination solution (niiro). This approach allows different alloys to be combined in one piece and patinated, producing a multi-colored piece of metalwork. At present the production of irogane alloys and their patination is an unreliable process. This study aims to develop reliable alloy production and a safe, easy-to use and repeatable patination process using standard ingredients available from chemical suppliers. The study has examined the production of shakudo and shibuichi alloys, characterizing the alloys produced by casting into cloth molds in hot water, into steel molds, and produced using continuous casting. The influence of traditional polishing methods was assessed using surface texture (Sa) measurements. Traditional rokusho, an ingredient of the niiro solution, was analyzed by XRF and XRD. Niiro patinated surfaces on a range of alloys were examined using XRD and L*a*b* color measurements.</p

Folate deficiency presenting as pyrexia: a case report

Folate deficiency is an uncommon cause of pyrexia. We describe the case of a 29-year-old male who presented with a pyrexial illness subsequently attributed to megaloblastic anaemia secondary to severe folate deficiency, after exclusion of other infective or inflammatory causes. A temperature chart documenting the course of the patient's pyrexia is presented and potential pathophysiological mechanisms are proposed. Folate deficiency is a reversible cause of pyrexia that should be considered in any patient who presents with a pyrexial illness of unknown cause

Ystyriaeth Feirniadol o Arwyddocd Moesegol Chwaraeon Rhyngwladol

Yn yr erthygl hon rydym yn herio’r syniad fod cenedlaetholdeb yn gyffredinol, a chenedlaetholdeb ar y maes chwarae yn arbennig, yn anfoesol. Er bod cenedlaetholdeb yn gallu cael ei lygru ar y maes chwarae ac mewn cyd-destunau eraill, nid yw hynny o reidrwydd yn anochel. Drwy drafod athroniaeth cenedlaetholdeb rhyddfrydol, fe fyddwn yn ceisio dangos bod derbyn ymlyniad diwylliannol a chenedlaethol yn hanfodol er mwyn hybu cymuned ryng-genedlaethol. Ymhellach, byddwn yn dadlau bod gan chwaraeon cenedlaethol botensial hynod arwyddocaol i greu fforwm a deialog lle y gall gwahanol ddinasyddion rannu a dysgu oddi wrth ei gilydd. In this paper we challenge the idea that nationalism in general, and sporting displays of nationalism in particular, are morally problematic. Whilst sporting displays of nationalism are often accompanied by ethnocentric and jingoistic tendencies, it does not follow that such competition is inherently problematic. By drawing on Liberal Nationalist philosophy, we argue that accepting and celebrating particular cultural and national ties represent a fundamental step towards encouraging an international and cosmopolitan mindset. Moreover, we argue that international sport has significant potential in stimulating meaningful cultural conversations, both within and between national communities

The development and application of structural priors for diffuse optical imaging in infants from newborn to two years of age

This thesis describes the development and application of age-appropriate structural priors to improve the localisation accuracy of diffuse optical tomography (DOT) approaches in infants aged from birth to two years of age. Knowledge of the target cranial anatomy, known as a structural prior, is required to produce three-dimensional images localising concentration changes to the cortex. A structural prior would ideally be subject-specific, i.e. derived from structural magnetic resonance imaging (MRI) data from each specific subject. Requiring a structural scan from every infant participant, however, is not feasible and undermines many of the benefits of DOT. A review was conducted to catalogue available infant structural MRI data, and selected data was then used to produce structural priors for infants aged 1- to 24-months. Conventional analyses using functional near-infrared spectroscopy (fNIRS) implicitly assume that head size and array position are constant across infants. Using DOT, the validity of assuming these parameters constant in a longitudinal infant cohort was investigated. The results show that this assumption is reasonable at the group-level in infants aged 5- to 12-months but becomes less valid for smaller group sizes. A DOT approach was determined to illicit more subtle effects of activation, particularly for smaller group sizes and expected responses. Using state-of-the-art MRI data from the Developing Human Connectome Project, a database of structural priors of the neonatal head was produced for infants aged pre-term to term-equivalent age. A leave-one-out approach was used to determine how best to find a match between a given infant and a model from the database, and how best to spatially register the model to minimise the anatomical and localisation errors relative to subject-specific anatomy. Model selection based on the 10/20 scalp positions was determined to be the best method (of those based on external features of the head) to minimise these errors

Synthesis and tribology of Sialon/TiB2 ceramic composites

The inclusion of TiB2 particles in a Si3N4 or sialon matrix has the potential to improve the materials properties over those of the Si3N4 alone. The combination of the excellent properties of sialon and the high hardness of the TiB2 makes these materials potentially suitable for tribological applications. This research has investigated the use of chemical reactions that can take place during sintering to synthesise TiB2 from TiN and BN. The reactions not only produce TiB2 but simultaneously synthesise the matrix material. The sialon matrix is used as a flexible receptor for excess nitrogen and oxygen. Using such reactions, sialonlTiB 2 composites were successfully produced by both hot pressing and pressureless sintering. It was shown that these materials achieve densities close to the theoretical and contain only the required phases of TiB2 and ~ sialon. Pressureless sintered materials also contain residual sintering aid as an intergranular phase. The composites wee characterised with respect to their microstructure, hardness, fracture toughness and tribological properties. A specially designed wear test apparatus was constructed for the tribological testing. The pin-on-disc apparatus was capable of testing the small volumes of material (minimum diameter of disc ~ 15mm) typically produced at the development stage. The materials were found to have high hardness and reasonable fracture toughness which was attributed primarily to the properties of the matrix phase with some possible toughening from the presence of TiB 2 . Tribological testing revealed high dry sliding coefficients of friction (Jl) for the composites sliding on themselves and reasonable values for the wear coefficient (k) were measured. Wear was found to be dominated by tribochemical reactions forming tribofilms which act to reduce wear of the disc. However, the presence of TiB2 was not seen to contribute directly to the tribological properties of these materials and the usefulness of this type of composite is questioned

Belousov-Zhabotinsky droplet mixing on-chip for chemical computing applications

Without an imposed physical structure, even the most complex chemistries are limited in their ability to process information. For example, the Belousov-Zhabotinsky (BZ) oscillating reaction has been shown to have information procession potential, but only if structure is imposed e.g. using physical barriers or light-sensitive catalysts. Recently, separated BZ droplets in oil have been investigated. Another option for aqueous/oil systems is to add lipid into the oil, which self-assembles into a monolayer at the phase boundary. If the lipid-stabilised droplets are brought into contact, a bilayer is formed, separating the BZ droplets into compartments. This technique is more flexible than other methods of imparting structure, allowing for the creation of droplet arrays inspired by biological neuronal networks

The use of friction stir welding for the production of Mokume Gane-Type materials

Mokume gane is a highly desirable and unique decorative material but production is difficult at both workshop and industrial levels. This paper describes a novel method for producing mixed metal, multi-colored, layered materials using friction stir welding (FSW) and compares the results with mokume gane made by a number of different conventional methods. FSW was invented in 1991 by TWI, a UK-based research and technology organization, and has found widespread use in the joining of aluminum and, more recently, steels. By adapting FSW it has been possible to successfully bond many layers of dissimilar metals such as silver, copper and brass, etc., while simultaneously producing unique patterns in the metal, minimizing further processing, reducing waste and potentially lowering costs. The technique avoids many of the problems experienced in workshop production, e.g., melting of lack of bonding, while allowing production of small, customized ingots and mass production of large sheets, with up to several square meters possible

Determination of the Cause of the Differing Ballistic Performance of 9mm DM11 Bullets from Two Manufacturers

In London, firearm threats faced by police during criminal activity include 9mm handguns and submachine guns. The UK Home Office body armour standards have included 9mm DM11 A1B2, manufactured originally by Dynamit Nobel under RWS branding, for over a decade. The recently published 2017 UK Home Office body armour standard continues to specify the 9mm DM11 A1B2, however, the specified manufacturer has changed to Metallwerk Elisenhütte GmbH (MEN). The DM11 A1B2 bullet comprises a copper coated steel full metal jacket with a lead core and bullets from both are specified to the same drawings and dimensional tolerances. However, during empirical testing against soft armour systems differences have been observed in the Vmean measured by CPA for the 2 bullets. As a result, body armour systems designed to pass the standard tests using the RWS 9mm DM11 A1B2 bullet manufactured may have a lesser safety margin when subject to impact with the equivalent MEN bullet. This paper reports on the results of an investigation in to the causes of the differing performance of the two sources of 9mm DM11 A1B2 bullets. It includes a study of the metallurgy of the steel jacket, dimensional and mass comparisons and a range of high strain rate testing to compare the properties and deformation behaviour of the two bullet types. Ballistic tests have been performed to demonstrate how the difference in performance may be related to the observed differences in the steel jacket metallurgy and the resulting differing deformation behaviour. The study has shown that the root cause of the differing performance is due primarily to differences in the steel used for the jackets by the different manufacturers. This work has important consequences for the UK body armour industry and others testing with the 9mm DM11 round

Non-isothermal crystallization kinetics and stability of leucite and kalsilite from K2O-Al2O3-SiO2 glasses

The crystallization mechanisms and elemental stability of leucite and kalsilite formed from K2O-Al2O3-SiO2 glasses were investigated by X-ray powder diffraction (XRD), X-ray fluorescence (XRF), Raman spectroscopy and differential scanning calorimetry (DSC). Glass samples with compositions along the leucite-kalsilite tie-line were produced by melt processing; and were then heat treated at 850ºC, 950ºC and 1250ºC for times ranging from 5 minutes to 1000 hours. Kalsilite is an unstable phase that behaves as an intermediate precursor to leucite. Crystalline materials in which kalsilite is the major phase lose potassium upon prolonged heat treatment (1000 hours at 1250ºC), in contrast to those with leucite, in which little or no compositional alteration is detected. The formation of leucite from stoichiometric kalsilite is accompanied by the formation of potassium doped alumina. The activation energies for leucite and kalsilite crystallization, determined via application of the Kissinger equation to thermal analysis data, were 579 kJ/mol and 548 kJ/mol respectively. Finally, production of pure leucite can be achieved with more favourable crystallization kinetics when starting with off-stoichiometric compositions