Observational Tests of Open Strings in Braneworld Scenarios

We consider some consequences of describing the gauge and matter degrees of freedom in our universe by open strings, as suggested by the braneworld scenario. We focus on the geometric effects described by the open string metric and investigate their observational implications. The causal structure of spacetime on the brane is altered; it is described not by the usual metric $g_{\mu\nu}$, but instead by the open string metric, that incorporates the electromagnetic background, $G_{\mu\nu} = g_{\mu\nu} - (2\pi \alpha^\prime)^2 (F^2)_{\mu\nu}$. The speed of light is now slower when propagating along directions transverse to electromagnetic fields or an NS-NS two form, so that Lorentz invariance is explicitly broken. A generalized equivalence principle guarantees that the propagation of {\it all} particles, not just photons, (with the exception of gravitons) is slower in these transverse directions. We describe a variety of astrophysical and laboratory-based experiments designed to detect the predicted variations in the causal structure. We show that current technology cannot probe beyond open string lengths of $10^{-13}$ cm, corresponding to MeV string scales. We also point out that in a braneworld scenario, constraints on large scale electromagnetic fields together with a modest phenomenological bound on the NS-NS two-form naturally lead to a bound on the scale of canonical noncommutativity that is two orders of magnitude below the string length. By invoking theoretical constraints on the NS-NS two-form this bound can be improved to give an extremely strong bound on the noncommutative scale well below the Planck length, $\sqrt{|\theta|_{max}} < 10^{-35} {\rm cm} \times ({{\rm TeV} \over {\rm string} {\rm scale}}Comment: Minor grammatical corrections and two reference added. 27 pages, 1 eps figure. Submitted to JHE

Point Contacts in Modeling Conducting 2D Planar Structures

Use of an optimization algorithm to improve performance of antennas and electromagnetic structures usually ends up in planar unusual shapes. Using rectangular conducting elements the proposed structures sometimes have connections with only one single point in common between two neighboring areas. The single point connections (point crossing) can affect the electromagnetic performance of the structure. In this letter, we illustrate the influence of point crossing on dipole and loop antennas using MoM, FDTD, and FEM solvers. Current distribution, radiation pattern, and impedance properties for different junctions are different. These solvers do not agree in the modeling of the point crossing junctions which is a warning about uncertainty in using such junctions. However, solvers agree that a negligible change in the junction would significantly change the antenna performance. We propose that one should consider both bridging and chamfering of the conflicting cells to find optimized structures. This reduces the simulation time by 40% using FDTD modeling, however no significant reduction is obtained using the MoM and FEM methods.Comment: 4 pages, 10 figures, 1 table, accepted for publication in IEEE Antennas Wireless Propag. Let

Influence of diluent alkyl substitution on the extraction of Am(III) and Eu(III) by a 6,6’-bis(1,2,4-triazin-3-yl)-2,2’-bipyridine ligand dissolved in alkylated cyclohexanone Diluents

Several alkylated cyclohexanones were investigated as potential diluents for the selective extraction of Am(III) from Eu(III) from nitric acid solutions by the CyMe4-BTBP ligand. No significant extraction of either of the metal ions was observed for these diluents themselves. In the extractions from 1 M HNO3, 3-methylcyclohexanone and 4-methylcyclohexanone gave comparable results to cyclohexanone whereas in the extractions from 4 M HNO3, 2-methylcyclohexanone, 3-methylcyclohexanone and 4-methylcyclohexanone all gave superior results. For the monomethylated diluents, DAm and SFAm/Eu decreased in the order of alkyl substitution 2 > 4 ~ 3. However, alkyl substitution of cyclohexanone significantly slows down the extraction kinetics compared to cyclohexanone, and the position of alkyl substitution was found to play an important role in the solvents properties. 3-Methylcyclohexanone was identified as the most promising of the diluent

Revisit the Curriculum Components for the Preparation of Health Services Managers

This paper is to revisit a curriculum component of health services management (HSM) at universities in Australia that can be used as reference for working with universities to develop their curriculum. The peer reviewed publications, with an emphasis on articles reporting research were identified. The findings set out exactly the most curriculums offered. Further research need to be conducted in other countries offered the similar program and the correlation will be reported on at a later date. The findings can be used to explain the concept of health services management to those new to the subject, and particularly to universities and health services managers to be. This paper seeks to fill the gap between in-depth, scholarly and complex articles about HSM and very simple descriptive articles

Archaeology of time – activation of installation space by the spect-actor

An artistic installation implies theatre in situ, in that a/the space is transformed into a potential experiential encounter through design and scenography. This potential space then only requires the spectator to activate the full experience through embodied engagement with the installation, inciting visceral meaning-making. This embodied activation implies that the spectator then also becomes a performer, as they are simultaneously the ones physically causing the theatrical experience and the ones experiencing the elements designed for (their) interpretation. In this manner a heightened sense of becoming what Boal (1992) coined the ‘spect-actor’ is achieved. By activating the space through physical engagement with/in the installation where all the sensory receptors trigger a visceral response in the spect-actor, meaning-making occurs through phenomenology and implies a knowing body through personal- and socio-cultural interpretation. For this paper, the installations by renowned South African artist Jan van der Merwe are used as examples to argue for the emergence of the spect-actor in the role of activator. As an installation artist, Van der Merwe creates large artworks of intricately recreated tableaux often composed in discarded, rusted found material. Van der Merwe calls the found objects “artefacts of our time”. Thus, they assume an archaeological quality and become relics of a way of life, a civilisation degenerated and fossilised though time and rust. The spect-actor is both then the site and cite of activation where the time and space converge into an ephemeral experience. Ho epolloa ha lintho tsa khale nako: ts'ebetso ea sebaka sa tlhomamiso ke moetsi oa spect-actor Boetsi ba bonono bo ikhethileng ka tshebediso ya ditshwantsho sebakeng ho bontša hore ho na le liketsahalo tsa sethala, ka hore sebaka se fetoha sebopeho se nang le phihlelo ka ho qaptjoa le ho shebahala. Sebaka sena se ka etsahala habonolo feela se hloka hore mmoheli a khone ho etsa boiphihlelo bo feletseng ka ho khomahanya ka ketsahatso, e leng tsela ya ho khothalletsa ho etsa moelelo oa visceral. Tshebetso ena e ncha e fana ka maikutlo a hore motho ea shebellang le ena o fetoha sebapali, kaha ka nako e tšoanang o etsa hore ho be le boiphihlelo ba papali ho ba nang le likarolo tse etselitsoeng tlhaloso ea bona. Ka tsela ena ho ba le kutloisiso e phahameng ea ho ba seo Boal (1992) a ileng a se bitsa hore ke mmohi-sebapali se fihlelloe. Ka ho futhumatsa sebaka ka tsela ya ho sebelisa mmele har’a mosebetsi wa bonono o pampiri ena e baung ka ona, e leng ona o lokollang li-receptor tsohle tse utloahalang hore li hlahise karabo ea visceral ho mmohi-sepali. Ho etsa moelelo o etsahalang ka phenomenology ho bolela mmele o tsebang ka litlhaloso tsa setso. Bakeng sa pampiri ena mesebetsi ea bonono ea moetsahatsi oa Afrika Boroa ea tummeng, Jan van der Merwe, e tla sebelisoa e le mohlala ho pheha khang ka ho hlaha ha mmohi-sebapali karolong ea motho ea futhumatsang le ho etsahatsa mosebetsi wa bonono ka nako eo o etsahalang ka yona. Joalokaha moetsahatsi oa bonono, van der Merwe o etsa litšoantšo tse kholo tsa seka-litšoantšo tse entsoeng ka mokhoa o rarahaneng o atisang ho etsoa ka thepa e lahliloeng, e bolileng. Van der Merwe o bitsa lintho tse a lifumaneng ho etsa mosebetsi oa hae "lintho tsa nako ea rona". Ka hona, ntho tsena linka seemo sa lintho tsa khale tse epollotsoeng ebe lifetoha litšoantšo tsa mokhoa oa bophelo, tsoelo-pele e ileng ea khutlela moraho le ho khitloa nakong. Ha hole joalo, mmohi-sepabali eba sebaka le moetsahatsi wa futhumatso tsebetsong moo nako le sebaka li fetohang phihlelo ea ho iphelisa. &nbsp; https://doi.org/10.19108/KOERS.85.1.247

Clinical academic career pathway for nursing and allied health professionals: clinical academic role descriptors

The clinical academic pathway outlined highlights the range of typical practice and research-focused activities that a practitioner on a clinical academic career pathway might normally engage in at different levels and points along this career path. The activities are intended as a guide for practitioners interested in learning more about the practice and research components of a clinical academic career, as well as those already employed in clinical academic roles. They may also be useful for health care organisations and Higher Education Institutions as a tool for developing clinical academic roles

Raman Spectroscopic Analysis of Geological and Biogeological Specimens of Relevance to the ExoMars Mission

H.G.M.E., I.H., and R.I. acknowledge the support of the STFC Research Council in the UK ExoMars programme. J.J. and P.V. acknowledge the support of the Grant Agency of the Czech Republic (210/10/0467) and of the Ministry of Education of the Czech Republic (MSM0021620855).Peer reviewedPublisher PD