[en] In this Letter we show that the worldline reparametrization for particles with higher derivative interactions appears as a higher-dimensional symmetry, which is generated by a truncated Virasoro algebra. We also argue that for generic nonlocal particle theories the fields on the worldline may be promoted to those living on a two-dimensional worldsheet, and the reparametrization symmetry becomes locally the same as the conformal symmetry

[en] A variety of in-situ diagnostic methods employing lasers have been used to study the fundamental chemical and physical processes that occur during the chemical vapor deposition of silicon from silane and dichlorosilane. These nonintrusive methods can detect chemical species such as reactants, products, reactive intermediates, and particulates that are present in the gas phase during CVD. These methods can also be used to measure fluid-dynamics properties such as temperature and velocity fields. It is found that gas-phase processes are an important part of chemical vapor deposition

[en] An industrial process for the CVD of silicon nitride from SiF₄ and NH₃ was studied with a wide variety of techniques, ranging from numerical models of the coupled chemistry and fluid mechanics to experimental studies of chemical reactions. The latter includes a set of molecular beam experiments that probed the temperature and flux dependencies of the reaction of SiF₄ and NH₃ at the surface. These experiments showed that the CVD reactor chemistry was dominated by surface kinetics rather than gas-phase decomposition

[en] The experimental work involves the use of laser spectroscopic techniques for in situ measurements on the gas phase in a chemical vapor deposition reactor. The theoretical part of the program consists of a computer model of the coupled fluid mechanics and gas-phase chemical kinetics of silane decomposition and subsequent reactions of intermediate species. The laser measurements provide extensive data for thoroughly testing the predictive capabilities of the model

[en] Efforts to implement Small Modular Reactor (SMR) technologies continue to progress in a variety of locations worldwide. Specific to Canada, there are ongoing projects in Ontario, New Brunswick, and Saskatchewan, each at varying degrees of maturity. One of the key benefits associated with SMRs, in comparison to existing large-scale reactors,is the potential for significantly reduced off-site radiological consequences following a nuclear accident. The potential for reduced off-site radiological consequences also provides an opportunity to optimize the emergency management framework for SMR technologies.There are ongoing initiatives within the Canadian nuclear industry to define potential changes required to existing regulatory requirements and industry standards in the area of emergency management. In support of these industry initiatives,Kinectrics has consolidated lessons learned in attempting to apply existing emergency management frameworks to SMRs. Specifically, these lessons learned were obtained in applying regulatory documentation such as REGDOC-2.10.1, REGDOC-1.1.1, REGDOC-1.1.2, REGDOC-1.1.3, as well as industry standards, such as CSA N286 and N1600, to various SMR technologies. These lessons learned are intended to be generic in nature as the potential for reduced off-site radiological consequences is a common characteristic of several SMR technologies.Lessons learned from Kinectrics’ experience to date have been consolidated into a series of key focus areas (e.g., emergency planning basis and planning zone sizes, extent of off-site monitoring equipment required, technical basis for applicability of specific requirements associated with reactor thermal power). Each of these focus areas will be discussed to summarize relevant lessons learned and identify potential clarifications/enhancements to increase the ease in which regulatory requirements/industry standards can be applied to various SMR technologies. (author)

[en] The rotational spectrum of the X¹Σ⁺ (v=0) - A¹PI (v=1) transition of CO is measured and analyzed for 25 less than or equal to J less than or equal to 62. The rotationally hot CO is generated by photolysis of formaldehyde (H₂CO)

[en] We used rat proximal tubule fragments purified by Percoll centrifugation to examine the role of diacylglycerol (DAG) in noradrenergic-stimulated Na+ reabsorption. Tubular DAG concentration and ouabain-inhibitable 86Rb uptake increased within 30 s after adding norepinephrine (NE) and remained elevated for at least 5 min. NE (1 microM) increased DAG content 17% and ouabain-inhibitable 86Rb uptake 23%. Cirazoline-stimulated 86Rb uptake was not inhibited by BaCl, quinidine, or bumetanide (1-10 microM) or by the omission of HCO3- or Cl- from the medium, but it was completely inhibited by ouabain and furosemide. Oleoyl-acetyl glycerol, L-alpha-1,2-dioctanoylglycerol, and L-alpha-1,2-dioleoylglycerol (DOG) increased total 86Rb uptake 8-11%. 12-O-tetradecanoylphorbol-13-acetate (TPA) (5 nM) increased uptake by only 4%. Staurosporine at 5 nM inhibited DOG stimulation completely, whereas 50 nM staurosporine was required to inhibit NE stimulation completely. Sphingosine inhibited DOG stimulation by 66% but did not inhibit NE stimulation. Amiloride (1 mM) completely blocked DOG stimulation. Monensin increased 86Rb uptake 31% and completely blocked the DOG effect but reduced the NE effect by only 26% (P = 0.08). In tubules from salt-loaded rats, NE did not increase DAG concentration, but NE-stimulated 86Rb uptake was reduced by only 23% (P = 0.15). Thus DAG released by NE may stimulate Na+ entry through Na(+)-H+ exchange. NE predominantly stimulates Na(+)-K(+)-adenosinetriphosphatase (ATPase) by activating a protein kinase that is insensitive to DAG and TPA and is inhibited by staurosporine but not by sphingosine. NE may also stimulate K+ efflux through a BaCl-insensitive K+ channel that is inhibited by millimolar furosemide

[en] Pulsed laser-Raman spectroscopy and laser-excited fluorescence have been used to profile reactive species concentrations inside a chemical vapor deposition cell. Experimental data and theoretical calculations indicate that gas-phase chemical kinetics plays an important role in the deposition process. The considerable amount of gas-phase chemistry is due to the fact that a chemical vapor deposition (CVD) reactant such as silane rapidly decomposes at temperatures above 500⁰C

No abstract available

[en] Using laser-excited fluorescence, free-radical HSiCl has been detected in the gas phase during the chemical vapor deposition of silicon from dichlorosilane. Profiles of the relative HSiCl density were measured at atmospheric and low total pressures. Previous studies of chlorosilane deposition have not considered HSiCl as a possible intermediate species. Therefore, its role in the deposition process must be investigated