[en] A 5-wk-old male presented with radiographic findings of a duplicated collecting system. A [/sup 99m/Tc]DMSA scan was requested to evaluate cortical function. Images obtained immediately. postinjection showed activity restricted to the upper poles; in contrast, delayed images at 4 hr showed activity in the bladder and throughout both kidneys. Catheterizing the patient drained the activity from the bladder but had little effect on the refluxed renal activity. The early [/sup 99m/Tc]DMSA images were critical in making the proper interpretation. Technetium-99m DMSA is excreted into the urine and this fact needs to be considered when interpreting scans of patients with possible reflux or obstruction. When DMSA scans are obtained in pediatric patients with possible reflux, catheterization prior to the study and early images prior to the appearance of DMSA in the collecting system are recommended

[en] Environmental awareness is essential for todays corporation. Corporations have been held liable for the short-term and long-term effects of such chemicals as pharmaceuticals, agrochemicals and petrochemicals to name a few. Furthermore, corporations have been held accountable for disposal of wastes or by-products of chemical production. Responsibility for the environment either mandated by government agencies or done voluntarily is an economic factor for business operations. Remediation of environmental hazards on a voluntary basis has often created goodwill and a payoff for being socially responsible. Remediation also can result in new business opportunities or savings in production costs. To be environmentally aware and socially responsible, the chemist should know where to find regulatory information for countries worldwide. Using online data sources is an efficient method of seeking this information

[en] We examine some leading-order flow and stability properties of smectic A (SmA) liquid crystals (LCs) in two spatial dimensions by analysing a fully nonlinear continuum theory of these materials. We derive a system of equations for the dynamic variables describing the flow velocity and orientation of the material under suitable assumptions upon these quantities. This system can provide insight into the leading-order behaviour under quite general circumstances, and we provide an example of utilising this system to determine the flow induced by a constant pressure gradient applied normally to the smectic layers. We then consider the effect of oscillatory perturbations on a relaxed, stationary sample of SmA, and provide criteria under which one would expect to see the onset of instability in the form of inequalities between the material parameters and perturbative wave number. We find that instability occurs for physically realisable values of these quantities, and, in particular, that certain viscosities characterising the SmA phase can act as ‘destabilising agents’ such that one could, for a given sample with known parameter values, manipulate the behaviour of that sample. (paper)

[en] The signatures of energy release and energy transport for a kink-unstable coronal flux rope are investigated via forward modeling. Synthetic intensity and Doppler maps are generated from a 3D numerical simulation. The CHIANTI database is used to compute intensities for three Hinode /EIS emission lines that cover the thermal range of the loop. The intensities and Doppler velocities at simulation-resolution are spatially degraded to the Hinode /EIS pixel size (1″), convolved using a Gaussian point-spread function (3″), and exposed for a characteristic time of 50 s. The synthetic images generated for rasters (moving slit) and sit-and-stare (stationary slit) are analyzed to find the signatures of the twisted flux and the associated instability. We find that there are several qualities of a kink-unstable coronal flux rope that can be detected observationally using Hinode /EIS, namely the growth of the loop radius, the increase in intensity toward the radial edge of the loop, and the Doppler velocity following an internal twisted magnetic field line. However, EIS cannot resolve the small, transient features present in the simulation, such as sites of small-scale reconnection (e.g., nanoflares).

[en] In this work the theoretical design and experimental realisation of a photonic Hilbert transformer is investigated. Planar Bragg gratings are proposed as a route to realise photonic Hilbert transformers in terms of a finite bandwidth and temporal impulse response. With proper grating apodisation and π-phase shift, the Bragg grating will display the spectral features expected from a Hilbert transformer. The unique features of Direct UV grating writing technology are used to fabricate the proposed device in silica-on-silicon

[en] We discuss the static configuration of a smectic A liquid crystal subject to an edge dislocation under the assumption that the director and layer normal fields ($\mathit{n}$ and $\mathit{a}$, respectively) defining the smectic arrangement are not, in general, equivalent. After constructing the free energy for the smectic, we obtain exact solutions to the equilibrium equations which result from its minimisation at quadratic order in the variables which describe the distortion, and hence a complete description of the smectic configuration across the domain of the sample. We also examine the effect of relaxing the constraint $\mathit{n}\equiv <!--\; ???\; -->\mathit{a}$ for different values of the constants which characterise the response of the material to distortions, and compare these results with the ‘classical’ case considered by previous authors, in which equivalence of $\mathit{n}$ and $\mathit{a}$ is enforced. (paper)