Light Front Quantisation of Gauge Theories in a Finite Volume

We discuss the light-front formulation of SU(2) Yang-Mills theory on a torus. The gauge choice we use allows for an exact and unambiguous solution of Gauss's law.Comment: 4 pages, Latex; talk presented at QCD 94, Montpellier, France, July 7-13, and at the Fourth International Workshop on Light Cone Quantization and Non- Perturbative Dynamics, Polana Zgorzelisko, Poland, August 15-25, TPR 94-2

Boson Dominance in nuclei

We present a new method of bosonization of fermion systems applicable when the partition function is dominated by composite bosons. Restricting the partition function to such states we get an euclidean bosonic action from which we derive the Hamiltonian. Such a procedure respects all the fermion symmetries, in particular fermion number conservation, and provides a boson mapping of all fermion operators.Comment: 12 page

Hamiltonian Approach to the Gribov Problem

We study the Gribov problem within a Hamiltonian formulation of pure Yang-Mills theory. For a particular gauge fixing, a finite volume modification of the axial gauge, we find an exact characterization of the space of gauge-inequivalent gauge configurations.Comment: 4 pages, 2 PICTEX figures, uses espcrc2.sty, talk presented at QCD 96, July 4-12, Montpellier, Franc

Hydrogen absorption properties of amorphous (Ni0.6Nb0.4−yTay)100−xZrx membranes

Ni based amorphous materials have great potential as hydrogen purification membranes. In the present work the melt spun (Ni0.6Nb0.4−yTay)100−xZrx with y=0, 0.1 and x=20, 30 was studied. The result of X-ray diffraction spectra of the ribbons showed an amorphous nature of the alloys. Heating these ribbons below T < 400 °C, even in a hydrogen atmosphere (1−10 bar), the amorphous structure was retained. The crystallization process was characterized by differential thermal analysis and the activation energy of such process was obtained. The hydrogen absorption properties of the samples in their amorphous state were studied by the volumetric method, and the results showed that the addition of Ta did not significantly influence the absorption properties, a clear change of the hydrogen solubility was observed with the variation of the Zr content. The values of the hydrogenation enthalpy changed from ~37 kJ/mol for x=30 to ~9 kJ/mol for x=20. The analysis of the volumetric data provides the indications about the hydrogen occupation sites during hydrogenation, suggesting that at the beginning of the absorption process the deepest energy levels are occupied, while only shallower energy levels are available at higher hydrogen content, with the available interstitial sites forming a continuum of energy levels

A foot in both camps: Redressing the balance between the \u2018pure\u2019 and applied branches of translation studies

The aim of this article is to argue for an approach to translation research integrating/bridging the divide between the descriptive, theoretical and applied branches of Translation Studies (TS). Based on a perspective of translation as cross-cultural communication centred on language and as a professional activity where the translator makes decisions, the branch of Applied Translation Studies (ATS) is seen not just as an \u201cextension\u201d of the \u201cpure\u201d branches of TS (Theory and Description), or one where theoretical statements based on the results of descriptive studies are transmitted in a unidirectional way (Toury 1995: 17-19). Rather, the applied strand of TS covering translation teaching and practice, translation quality assessment, the development of translation aids etc. is effectively incorporated in the disciplinary core of TS, providing a site for testing theoretical statements, identifying problems and providing explanations to be fed into the theory

Artisanal & small-scale gold mining research field work, Migori County, Kenya

Artisanal & Small-scale Gold Mining (ASGM) is a subsistence level livelihood for many rural communities across the world. In Kenya it provides work for an estimated 40,000 people and produces 5 tonnes of gold per year. The impact of ASGM is double-edged with the economic benefits offset by damage to the environment and the health of the mining communities, particularly due to the widespread use of mercury to recover gold. As a signatory to the Minamata Convention on Mercury, Kenya has agreed to eliminate the use of mercury, formalise the ASGM sector, introduce good practice and protect the health of mining communities. Migori County is a major ASGM centre in southwest Kenya where gold is produced from the quartz–carbonate reefs in the Migori greenstone belt. Recovery of gold involves extraction of the ore by mining. The deep mine shafts are unstable and dangerous places to work. There are regular reports of fatalities due to mine collapse. The gold is recovered by manual crushing, ball milling, sluice box concentration and mercury amalgamation. Residual gold in the tailings is recovered by cyanidation. The local ASGM communities are primarily concerned about the safety of the mining, the environmental impact of mercury and poor gold recovery. The extent to which pollution from the mining activities leaches into groundwater and impacts water resources is also unknown. The British Geological Survey (BGS) is working with the University of Nairobi and the Migori County Artisanal Miners Co-operative (MICA) to promote good ASGM practice, reduce mercury use and improve gold recovery using appropriate technology, alongside assessing the potential pressures ASGM poses on water resources. Samples of gold ore, crushed and milled ore, concentrates and tailings were collected from ASGM operations. On average hard rock gold is finer than 100 microns. This makes the use of a sluice box a very inefficient recovery method with expected recoveries as low as 20% for gold of 100 microns or finer. Characterisation of the ore will provide the particle-size distribution of the gold and enable the liberation size to be determined. Size analysis of the milled material is expected to show that the ore has been ‘over-milled’ with a large proportion finer than 50 microns. It is likely that some of the gold has been reduced in size to the point where simple gravity processing methods such as sluice boxes will not work. A total of 30 waters were sampled from shallow wells, boreholes, springs and mine shafts, to represent the different sources from which water is obtained by the public, during the period from the 15th to 20th November 2019, while assessment of surface water quality was carried out in a previous survey in January 2019. Mine processing waters and spoil runoff were also sampled. This work will develop good practice guidance for ASGM. It will include advice from a mining engineer to improve mine safety; the use of retorts to reduce mercury consumption; and the use of longer sluice channels (at least 3 metres), appropriate sluice box gradients, consistent sluice box feed supply, alternatives to manual crushing, modification to the milling and alternative processing methods to improve gold recovery. The analysis of the inorganic chemical status of groundwater in the ASGM areas around Migori will assess the potential pressures posed by ASGM on water resources. This BGS research project is part of the BGS Official Development Assistance (ODA) research project “From source to sink: Quantifying the local and downstream environmental impacts of ASGM”

Experimental realization of a broadband illusion optics device

We experimentally demonstrate the first metamaterial "illusion optics" device - an "invisible gateway" by using a transmission-line medium. The device contains an open channel that can block electromagnetic waves at a particular frequency range. We also demonstrate that such a device can work in a broad frequency range.Comment: 9 pages, 5 figure

Reconfigurable Adaptive Multiple Transform Hardware Solutions for Versatile Video Coding

Computer aided design is nowadays a must to quickly provide optimized circuits, to cope with stringent time to market constraints, and to be able to guarantee colliding constrained requirements. Design automation is exploited, whenever possible, to speed up the design process and relieve the developers from error prone customization, optimization and tuning phases. In this work we study the possibility of adopting automated algorithms for the optimization of reconfigurable multiple constant multiplication circuits. In particular, an exploration of novel reconfigurable Adaptive Multiple Transform circuital solutions adoptable in video coding applications has been conducted. These solutions have also been compared with the unique similar work at the state of the art, revealing to be beneficial under certain constraints. Moreover, the proposed approach has been generalized with some guidelines helpful to designers facing similar problems