Photo-ionization modelling of planetary nebulae -- II. Galactic bulge nebulae, a comparison with literature results

We have constructed photo-ionization models of five galactic bulge planetary nebulae using our automatic method which enables a fully self-consistent determination of the physical parameters of a planetary nebula. The models are constrained using the spectrum, the IRAS and radio fluxes and the angular diameter of the nebula. We also conducted a literature search for physical parameters determined with classical methods for these nebulae. Comparison of the distance independent physical parameters with published data shows that the stellar temperatures generally are in good agreement and can be considered reliable. The literature data for the electron temperature, electron density and also for the abundances show a large spread, indicating that the use of line diagnostics is not reliable and that the accuracy of these methods needs to be improved. Comparison of the various abundance determinations indicates that the uncertainty in the electron temperature is the main source of uncertainty in the abundance determination. The stellar magnitudes predicted by the photo-ionization models are in good agreement with observed values.Comment: Accepted for publication in MNRA

Micromachined Polycrystalline Sige-Based Thermopiles for Micropower Generation on Human Body

This paper presents a polycrystalline silicon germanium (poly-SiGe) thermopile specially designed for thermoelectric generators used on human body. Both the design of the single thermocouple and the arrangement of the thermocouple array have been described. A rim structure has been introduced in order to increase the temperature difference across the thermocouple junctions. The modeling of the thermocouple and the thermopile has been performed analytically and numerically. An output power of about 1 $\mu$W at an output voltage of more than 1 V is expected from the current design of thermopiles in a watch-size generator. The key material properties of the poly-SiGe have been measured. The thermopile has been fabricated and tested. Experimental results clearly demonstrate the advantage of the rim structure in increasing output voltage. In presence of forced convection, the output voltage of a non-released thermopile can increase from about 53 mV/K/cm2 to about 130 mV/K/cm2 after the rim structure is formed. A larger output voltage from the thermopile is expected upon process completion.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/EDA-Publishing

Radio Observations of New Galactic Bulge Planetary Nebulae

We observed 64 newly identified galactic bulge planetary nebulae in the radio continuum at 3 and 6 cm with the Australia Telescope Compact Array. We present their radio images, positions, flux densities, and angular sizes. The survey appears to have detected a larger ratio of more extended planetary nebulae with low surface brightness than in previous surveys. We calculated their distances according to Van de Steene & Zijlstra (1995). We find that most of the new sample is located on the near side around the galactic center and closer in than the previously known bulge PNe. Based on H-alpha images and spectroscopic data, we calculated the total H-alpha flux. We compare this flux value with the radio flux density and derive the extinction. We confirm that the distribution of the extinction values around the galactic center rises toward the center, as expected.Comment: accepted for publication in A&

Comment on “providing value to new health technology: the early contribution of entrepreneurs, investors, and regulatory agencies”

Lehoux et al provide a highly valid contribution in conceptualizing value in value propositions for new health technologies and developing an analytic framework that illustrates the interplay between health innovation supply-side logic (the logic of emergence) and demand-side logic (embedding in the healthcare system). This commentary brings forth several considerations on this article. First, a detailed stakeholder analysis provides the necessary premonition of potential hurdles in the development, implementation and dissemination of a new technology. This can be achieved by categorizing potential stakeholder groups on the basis of the potential impact of future technology. Secondly, the conceptualization of value in value propositions of new technologies should not only embrace business/economic and clinical values but also ethical, professional and cultural values, as well as factoring in the notion of usability and acceptance of new technology. As a final note, the commentary emphasises the point that technology should facilitate delivery of care without negatively affecting doctorpatient communications, physical examination skills, and development of clinical knowledge.peer-reviewe

Synthesis of analogues of (E)-1-hydroxy-2-methylbut-2-enyl 4-diphosphate, an isoprenoid precursor and human γδ T cell activator

(E)-1-Hydroxy-2-methyl-but-2-enyl 4-diphosphate (HMBPP) is an intermediate in the non-mevalonate pathway for the biosynthesis of isoprenoids and also serves as a very strong activator of human gamma delta T cells expressing V gamma 9V delta 2 receptors. This paper describes the synthesis of analogues of HMBPP, in which the diphosphate group is replaced by potential isosteric moieties, i.e., carbamate, N-acyl-N'-oxy sulfamate, or aminosulfonyl carbamate functionalities. The potential of the synthesized analogues to stimulate V gamma 9/V delta 2 T cell response or to inhibit GcpE and LytB, the last enzymes in the non-mevalonate pathway, was assessed

A Herschel study of Planetary Nebulae

We present Herschel PACS and SPIRE images of the dust shells around the planetary nebulae NGC 650, NGC 6853, and NGC 6720, as well as images showing the dust temperature in their shells. The latter shows a rich structure, which indicates that internal extinction in the UV is important despite the highly evolved status of the nebulae.Comment: 2 pages, 1 figure, 2012, proceedings IAU Symposium 283 Planetary Nebulae: An Eye to the Futur