En bloc tibial thrombectomy

A 58-year-old man with hypertension and 40-pack year smoking history presented to the emergency department complaining of approximately 20 hours of right lower extremity pain

Optical characterisation of germanium optical fibres

Semiconductor core optical fibres are currently generating great interest as they promise to be a platform for the seamless incorporation of optoelectronic functionality into a new generation of all-fibre networks [1,2]. Although recent attentions have primarily focused on silicon as the material of choice for semiconductor photonics applications, germanium has some advantages over its counterpart. For example, it has higher nonlinearity, extended infrared transparency and has recently been demonstrated as a direct band gap laser medium [3]. Here we present the first optical characterisation of a germanium core optical fibre. The fibre was fabricated using a chemical micro fluidic deposition process [1] that uses GeH4 (germane) as a precursor to deposit amorphous germanium into the hole of a silica capillary. Figure 1 (a) shows an optical microscope image of the polished end face of a germanium fibre, with a 5.6 µm core diameter, which has been completely filled with the semiconductor material. Optical transmission measurements have been conducted over the wavelength range 2 µm to 11 µm, to confirm the broad mid-infrared operational window, and the guided output at 2.4 µm, imaged using a Spiricon Pyrocam III pyroelectric array camera, is shown in Figure 1 (b). At this wavelength the optical loss has been measured to be 20 dB/cm, which is comparable to losses measured for amorphous silicon fibres in the infrared. The potential for these germanium optical fibres to be used as optical modulators and infrared detectors will be discussed

Effect of the oxygen content in solution on the static and cyclic deformation of titanium foams

It is well known that interstitials affect the mechanical properties of titanium and titanium alloys. Their effects on the fatigue properties of titanium foams have not, however, been documented in the literature. This paper presents the effect of the oxygen content on the static and dynamic compression properties of titanium foams. Increasing the oxygen content from 0.24 to 0.51 wt% O in solution significantly increases the yield strength and reduces the ductility of the foams. However, the fatigue limit is not significantly affected by the oxygen content and falls within the 92 MPa \ub1 12 MPa range for all specimens investigated in this study. During cyclic loading, deformation is initially coming from cumulative creep followed by the formation of microcracks. The coalescence of these microcracks is responsible for the rupture of the specimens. Fracture surfaces of the specimens having lower oxygen content show a more ductile aspect than the specimens having higher oxygen content.Il est bien connu que les interstices affectent les propri\ue9t\ue9s m\ue9caniques du titane et des alliages de titane. Leurs effets sur les propri\ue9t\ue9s de fatigue des mousses de titane n\u2019ont cependant pas encore \ue9t\ue9 document\ue9s dans la litt\ue9rature. Dans le pr\ue9sent article, on pr\ue9sente l\u2019effet de la teneur en oxyg\ue8ne sur les propri\ue9t\ue9s de compression statique et dynamique des mousses de titane. L\u2019augmentation de la teneur en oxyg\ue8ne de 0,24 \ue0 0,51 % en poids en solution accro\ueet de mani\ue8re significative la limite d\u2019\ue9lasticit\ue9 conventionnelle et r\ue9duit la ductilit\ue9 des mousses. Toutefois, la limite de fatigue n\u2019a pas \ue9t\ue9 affect\ue9e de mani\ue8re significative par une teneur en oxyg\ue8ne dans la gamme de 92 \ub1 12 MPa pour tous les \ue9chantillons test\ue9s dans le cadre de la pr\ue9sente \ue9tude. Pendant une charge cyclique, la d\ue9formation provient initialement d\u2019un fluage cumulatif, suivi par la formation de microfissures. La coalescence de ces microfissures est responsable de la rupture des \ue9chantillons. Les surfaces des fissures dans les \ue9chantillons ayant une teneur en oxyg\ue8ne plus faible exhibent un aspect plus ductile que celles des \ue9chantillons ayant une teneur plus \ue9lev\ue9e en oxyg\ue8ne.Peer reviewed: YesNRC publication: Ye

Addressing the ethical issues associated with fieldwork education in occupational therapy: Results of an empirical study conducted in Quebec

Occupational therapists who contribute to fieldwork education are exposed to ethical issues when supervising trainees. Both the ethical issues and the solutions to address these ethical issues are undocumented in the literature. A qualitative study was conducted to document these issues and their solutions. Twenty-three occupational therapists with supervising experience participated in this study. All the participants reported experiencing ethical issues while supervising trainees. This article aims to present the solutions proposed by the participants in order to address the ethical issues of fieldwork education. Intrinsic solutions are linked to supervisors’ ethical, pedagogical or occupational therapy competences. The extrinsic solutions deal with the appropriate measures which can and should be implemented so as to better support the supervisors’ work and better recognize the important contribution of occupational therapists who train the next generation of occupational therapists in clinical settings. This study is likely to have implications on clinical practice, teaching, research and governance

Tailoring the pressure-drop in multi-layered open-cell porous inconel structures

This study investigates the pressure-drop behaviour associated with airflow through bulk and structurally tailored multi-layered, open-cell porous Inconel structures over a wide airflow velocity range (0–50 m s-1). The effect of airflow velocity on the pressure-drop behaviour as a function of the sample thickness is presented and related to the flow behaviour corresponding to the relevant flow regimes (Darcy, Forchheimer, Turbulent and Postturbulent). Entrance effects are highlighted as a source of the pressure-drop increase for porous structures with air gaps, regardless of their sizes, as long as they are larger than those generated by loosely-stacked structures. The pressure-drops for gapped porous structures and the mathematical-summation of the pressure drop for the corresponding individual components, were in very good agreement, at lower airflow velocities. The potential for mass-efficient porous structures, providing a high pressure drop, was demonstrated using multiple thin porous laminates separated by air gaps

Experimental investigation of pressure-drop characteristics across multi-layer porous metal structures

This study investigates the effect of airflow (in the range of 0–70 m s-1) on the pressure-drop characteristics for a novel multi-layered, nickel-based porous metal, as a function of thickness (affected by sectioning) and density (affected by compression). In addition to generating unique data for these materials, the study highlights the need for precise pinpointing of the different flow regimes (Darcy, Forchheimer and Turbulent) in order to enable accurate determination of the permeability (K) and form drag coefficient (C) defined by the Forchheimer equation and to understand the complex dependence of length-normalised pressure drop on sample thickness

Influence of normal and radial contributions of local current density on local electrochemical impedance spectroscopy.

A new tri-electrode probe is presented and applied to local electrochemical impedance spectroscopy (LEIS) measurements. As opposed to two-probe systems, the three-probe one allows measurement not only of normal, but also of radial contributions of local current densities to the local impedance values. The results concerning the cases of the blocking electrode and the electrode with faradaic reaction are discussed from the theoretical point of view for a disk electrode. Numerical simulations and experimental results are compared for the case of the ferri/ferrocyanide electrode reaction at the Pt working electrode disk. At the centre of the disk, the impedance taking into account both normal and radial contributions was in good agreement with the local impedance measured in terms of only the normal contribution. At the periphery of the electrode, the impedance taking into account both normal and radial contributions differed significantly from the local impedance measured in terms of only the normal contribution. The radial impedance results at the periphery of the electrode are in good agreement with the usual explanation that the associated larger current density is attributed to the geometry of the electrode, which exhibits a greater accessibility at the electrode edge

The Search for Higgs particles at high-energy colliders: Past, Present and Future

I briefly review the Higgs sector in the Standard Model and its minimal Supersymmetric extension, the MSSM. After summarizing the properties of the Higgs bosons and the present experimental constraints, I will discuss the prospects for discovering these particle at the upgraded Tevatron, the LHC and a high-energy $e^+e^-$ linear collider. The possibility of studying the properties of the Higgs particles will be then summarized.Comment: 28 pages, latex, 15 figures, talk at WHEPP VII, Allahabad, Indi

Pore-scale numerical investigation of pressure drop behaviour across open-cell metal foams

The development and validation of a grid-based pore-scale numerical modelling methodology applied to five different commercial metal foam samples is described. The 3-D digital representation of the foam geometry was obtained by the use of X-ray microcomputer tomography scans, and macroscopic properties such as porosity, specific surface and pore size distribution are directly calculated from tomographic data. Pressure drop measurements were performed on all the samples under a wide range of flow velocities, with focus on the turbulent flow regime. Airflow pore-scale simulations were carried out solving the continuity and Navier–Stokes equations using a commercial finite volume code. The feasibility of using Reynolds-averaged Navier–Stokes models to account for the turbulence within the pore space was evaluated. Macroscopic transport quantities are calculated from the pore-scale simulations by averaging. Permeability and Forchheimer coefficient values are obtained from the pressure gradient data for both experiments and simulations and used for validation. Results have shown that viscous losses are practically negligible under the conditions investigated and pressure losses are dominated by inertial effects. Simulations performed on samples with varying thickness in the flow direction showed the pressure gradient to be affected by the sample thickness. However, as the thickness increased, the pressure gradient tended towards an asymptotic value