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Postby cnorthcheaper » Sun Apr 15, 2018 10:23 pm

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<h1>Aquila omega costellazione doppia aquila</h1>
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L'Aquila è una costellazione di 652 gradi quadrati situata a cavallo dell'equatore celeste e che, salvo le estreme regioni orientali, si trova in piena Via Lattea. L'origine della costellazione è controversa, ma frugando nei meandri di antiche leggende e di fatti storici, ci troviamo sostanzialmente di fronte a due versioni. Secondo la prima, certamente più antica, l'aquila sarebbe l'uccello nel quale si era trasformato Giove per rapire il giovane Ganimede ed elevarlo al rango di coppiere degli dei, essendo il più bello di tutti i mortali. È però più noto l'episodio di Antinoo, il favorito di Adriano, il quale sacrificò la sua vita per l'imperatore gettandosi nel Nilo. Questo gesto terribile sembra fosse stato, determinato dal responso di un oracolo secondo il. quale l'imperatore versava in grave pericolo e la sua salvezza sarebbe dipesa solo dal sacrificio di colui verso cui manifestava maggior affetto. Per quest'atto eroico, Antinoo fu immortalato con templi e altari fatti innalzare in suo onore dallo stesso Adriano che, non contento di ciò, volle anche il nome del giovine scritto in cielo. Nell'Almagesto di Tolomeo troviamo la prima documentazione di questa nuova costellazione che è però già associata all'Aquila nella quale fu successivamente inglobata in modo definitivo.
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Con un po' di fantasia si può effettivamente ravvedere un uccello in volo nella disposizione delle stelle più brillanti della costellazione. <span class="a">Alfa Aquilae</span> è meglio nota, come <span class="a">Altair</span>, nome che deriva da <span class="a">el-nars-el-tair</span> ("l'aquila volante"); occupa il vertice più meridionale del Triangolo estivo e trova al 12° posto nella classifica delle stelle più brillanti del firmamento; tuttavia l'apparenza inganna: Altair è infatti uno degli astri di prima grandezza più vicini alla Terra, dalla quale dista vmxjzjwo. <a href="http://www.altreviste.com/ybtdqnes"><strong>klockor på nätet</strong></a> poco più di 16 anni luce, contro i 1600 di Deneb. Tuttavia, se ce la immaginassimo al posto del Sole farebbe certamente un figurone vederla brillare nel cielo diurno: un oggetto abbagliante, 10 volte più luminoso della nostra stella che inonderebbe il paesaggio di una vivida luce bianca simile a quella di un <i>flash</i> fotografico. Ma la cosa più sorprendente è che, osservata con opportune protezioni per gli occhi, non apparirebbe tonda come il Sole, ma molto schiacciata ai poli. Come possiamo saperlo? Lo si può dedurre dall'analisi quantitativa delle righe spettrali, le quali, in base all'allargamento che mostrano, denunciano un periodo di rotazione della stella formidabile: circa 6 ore e mezza contro gli oltre 25 giorni del Sole. Ciò vuol dire che, tenuto conto del diametro di Altair (quasi 2 milioni di chilometri) un punto situato sul suo equatore si muove all'incredibile velocità di 260 km/s, superiore alla velocità del Sistema Solare attorno al centro galattico! È un dato eloquente che ci fa capire come questa stella non possa. avere un corteggio di pianeti che le orbitano attorno simile a quello a noi familiare e che comunque deve aver luogo una continua dispersione di materiale dalla zona equatoriale dove maggiore è la forza centrifuga e, di conseguenza, minore la velocità di fuga dalla superficie. Altair possiede una compagna ottica di decima grandezza a quasi 3' di distanza che lentamente si sta separando dalla primaria a causa del moto proprio di quest'ultima, stimato attorno a 0",66 all'anno.
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Una doppia fisica è invece la <span class="a">Beta Aquilae</span>, in arabo <span class="a">Al-schain</span>, dal significato oscuro (forse "asta della bilancia"); è una stella giallo-arancio di 4&ordf; grandezza distante 45 anni luce da noi e di luminosità pari a 5 volte quella del Sole. Non è certo una doppia facile, perché la compagna è una debole stellina di 11&ordf; situata a 13" a nord.
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<span class="a">Gamma</span>, di 3&ordf; grandezza, è una gigante arancione 1350 volte più brillante del Sole e distante 460 anni luce.
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Subito dopo in ordine di luminosità troviamo la <span class="a">Zeta</span>, sempre di 3&ordf; grandezza; questa è una stella bianca della Sequenza Principale distante 83 anni luce e 34 volte più brillante del Sole.
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Le stelle che seguono immediatamente nella graduatoria sono <span class="a">Theta</span> e <span class="a">Delta</span>, rispettivamente 2 decimi e 3 decimi di magnitudo più deboli della Zeta. La 1&ordf; è bianca, distante 287 anni luce e 320 volte più luminosa del Sole; la 2&ordf; è un altro membro della Sequenza Principale, di colore bianco-giallastro, distante 50 anni luce e 9 volte più brillante della nostra Stella.
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<ol class="result-class" start="141">
<li>
<p><span>Realistic <span class="hlt">reference</span> adult and paediatric phantom series for <span class="hlt">internal</span> and external dosimetry.</span></p>
<p>PubMed</p>
<p>Stabin, M G; Emmons, M A; Segars, W P; Fernald, M J</p>
<p>2012-03-01</p>
<p>A new generation of realistic, image-based anthropomorphic phantoms has been developed based on the <span class="hlt">reference</span> masses and organ definitions given in the <span class="hlt">International</span> Commission on Radiological Protection Publication 89. Specific absorbed fractions for <span class="hlt">internal</span> radiation sources have been calculated for photon and electron sources for many body organs. Values are similar to those from the previous generation of 'stylized' (mathematical equation-based) models, but some differences are seen, particularly at low particle or photon energies, due to the more realistic organ geometries, with organs generally being closer together, and with some touching and overlapping. Extension of this work, to use these phantoms in Monte Carlo radiation transport simulation codes with external radiation sources, is an important area of investigation that should be undertaken.</p>
</li>
<li>
<p><span>A study to establish <span class="hlt">international</span> diagnostic <span class="hlt">reference</span> levels for paediatric computed tomography.</span></p>
<p>PubMed</p>
<p>Vassileva, J; Rehani, M; Kostova-Lefterova, D; Al-Naemi, H M; Al Suwaidi, J S; Arandjic, D; Bashier, E H O; Kodlulovich Renha, S; El-Nachef, L; Aguilar, J G; Gershan, V; Gershkevitsh, E; Gruppetta, E; Hustuc, A; Jauhari, A; Kharita, Mohammad Hassan; Khelassi-Toutaoui, N; Khosravi, H R; Khoury, H; Kralik, I; Mahere, S; Mazuoliene, J; Mora, P; Muhogora, W; Muthuvelu, P; Nikodemova, D; Novak, L; Pallewatte, A; Pekarovič, D; Shaaban, M; Shelly, E; Stepanyan, K; Thelsy, N; Visrutaratna, P; Zaman, A</p>
<p>2015-07-01</p>
<p>The article reports results from the largest <span class="hlt">international</span> dose survey in paediatric computed tomography (CT) in 32 countries and proposes <span class="hlt">international</span> diagnostic <span class="hlt">reference</span> levels (DRLs) in terms of computed tomography dose index (CTDI vol) and dose length product (DLP). It also assesses whether mean or median values of individual facilities should be used. A total of 6115 individual patient data were recorded among four age groups: <1 y, >1-5 y, >5-10 y and >10-15 y. CTDIw, CTDI vol and DLP from the CT console were recorded in dedicated forms together with patient data and technical parameters. Statistical analysis was performed, and <span class="hlt">international</span> DRLs were established at rounded 75th percentile values of distribution of median values from all CT facilities. The study presents evidence in favour of using median rather than mean of patient dose indices as the representative of typical local dose in a facility, and for establishing DRLs as third quartile of median values. <span class="hlt">International</span> DRLs were established for paediatric CT examinations for routine head, chest and abdomen in the four age groups. DRLs for CTDI vol are similar to the <span class="hlt">reference</span> values from other published reports, with some differences for chest and abdomen CT. Higher variations were observed between DLP values, based on a survey of whole multi-phase exams. It may be noted that other studies in literature were based on single phase only. DRLs reported in this article can be used in countries without sufficient medical physics support to identify non-optimised practice. Recommendations to improve the accuracy and importance of future surveys are provided.</p>
</li>
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<p><span>Evening and nighttime features of equatorial <span class="hlt">ionospheric</span> F2 layer</span></p>
<p>NASA Astrophysics Data System (ADS)</p>
<p>Oyekola, Oyedemi S.</p>
<p>2016-07-01</p>
<p>We have used ionosonde observations recorded at Ibadan (7.4 degree North, 3.9 degree East) during the <span class="hlt">International</span> Geophysical year (1957-58) to investigate evening and nighttime characteristic features of equatorial <span class="hlt">ionosphere</span> during high solar flux and quiet magnetic conditions. We have also used <span class="hlt">International</span> <span class="hlt">Reference</span> <span class="hlt">Ionosphere</span> model (IRI-2012) data. Our results show that the base of the <span class="hlt">ionosphere</span> descends at a rate of -27.5 km/hr between 2000 LT and 0400 LT, whereas the observed bottomside peak of the <span class="hlt">ionosphere</span> move down at a rate of -29.3 km/hr between 1900 and 0500 LT, while IRI2012 bottomside peak show -29.8 km/hr between 2000 LT and 0500 LT. The downward flow rate of plasma concentration between 1900 LT and 0500 LT and between 1800 LT and 0400 LT is approximately 0.040 electron per cubic metre per hour and 0.081 electron per cubic metre per hour, respectively for observed and for modeled NmF2. Month-by-month averaged altitudes (h'F, hmF2, and modeled hmF2) indicate significant local time variation. In addition, the month-by month variation indicates nighttime double crest of averaged peak height (hmF2) in the ionosonde measurements and in the IRI-2012 empirical model with a trough in June-August for data and In July for model. The monthly mean downward vertical drift velocities derived from local time variation of h'F and hmF2 together with global drift model essential demonstrate much fluctuations. We found a "domed shape" in modeled drift velocity, indicating equatorward plasma between April and September.</p>
</li>
<li>
<p><span>Photochemistry of planetary <span class="hlt">ionospheres</span></span></p>
<p>NASA Technical Reports Server (NTRS)</p>
<p>Nagy, Andrew F.</p>
<p>1987-01-01</p>
<p>The dominant photochemical reactions taking place in the <span class="hlt">ionospheres</span> of Venus, Saturn, and Comet P/Halley are presented. It is shown that the differences in the <span class="hlt">ionospheres</span> of these celestial bodies result from the different chemistry, energetics, and dynamics of the respective atmospheres. The role of photochemistry in the formation of the individual <span class="hlt">ionospheres</span> is discussed.</p>
</li>
<li>
<p><span>Middle Atmosphere Program. Handbook for MAP. Volume 31: <span class="hlt">Reference</span> models of trace species for the COSPAR <span class="hlt">international</span> <span class="hlt">reference</span> atmosphere</span></p>
<p>NASA Technical Reports Server (NTRS)</p>
<p>Keating, G. M. (Editor)</p>
<p>1989-01-01</p>
<p>A set of preliminary <span class="hlt">reference</span> atmosphere models of significant trace species which play important roles in controlling the chemistry, radiation budget, and circulation patterns of the atmosphere were produced. These models of trace species distributions are considered to be <span class="hlt">reference</span> models rather than standard models; thus, it was not crucial that they be correct in an absolute sense. These <span class="hlt">reference</span> models can serve as a means of comparison between individual observations, as a first guess in inversion algorithms, and as an approximate representation of observations for comparison to theoretical calculations.</p>
</li>
<li>
<p><span><span class="hlt">Ionospheric</span> Challenges for GNSS Based Augmentation Systems</span></p>
<p>NASA Astrophysics Data System (ADS)</p>
<p>Doherty, P.; Valladares, C. E.</p>
<p>2007-12-01</p>
<p>. LISN is a network of GNSS receivers and other <span class="hlt">ionospheric</span> sensors that are in the process of deployment and installation across the western half of South America. Its purpose is to address key questions about the physics of the equatorial <span class="hlt">ionosphere</span> and to develop forecasting/predictions capabilities concerning the onset of equatorial Spread F. The <span class="hlt">International</span> Civil Aviation Organization has committed to transition to satellite navigation. This presentation will summarize the effects and the limitations that the <span class="hlt">ionosphere</span> places on satellite based navigation systems.</p>
</li>
<li>
<p><span>Proposal of a candidate <span class="hlt">international</span> conventional <span class="hlt">reference</span> measurement procedure for free thyroxine in serum.</span></p>
<p>PubMed</p>
<p>Thienpont, Linda M; Beastall, Graham; Christofides, Nicholas D; Faix, James D; Ieiri, Tamio; Jarrige, Véronique; Miller, W Greg; Miller, Richard; Nelson, Jerald C; Ronin, Cathérine; Ross, H Alec; Rottmann, Michael; Thijssen, Jos H; Toussaint, Brigitte</p>
<p>2007-01-01</p>
<p>In the present paper the IFCC WG-STFT recommends and provides the rationale to establish metrological traceability of serum free thyroxine (FT4) measurements to a candidate <span class="hlt">international</span> conventional <span class="hlt">reference</span> measurement procedure. It is proposed that this procedure be based on equilibrium dialysis combined with determination of thyroxine in the dialysate with a trueness-based <span class="hlt">reference</span> measurement procedure. The measurand is thus operationally defined as "thyroxine in the dialysate from equilibrium dialysis of serum prepared under defined conditions". With regard to the trueness-based <span class="hlt">reference</span> measurement procedure, the WG-STFT recommends use of an isotope dilution-liquid chromatography/tandem mass spectrometry (ID-LC/tandem MS) procedure for total thyroxine that has been optimized towards measurement at picomolar concentration levels and that is listed in the database of the Joint Committee for Traceability in Laboratory Medicine (JCTLM). For calibration, the purified thyroxine material IRMM-468 (resulting from a project funded by the European Commission and recently submitted to the JCTLM) is proposed. The WG-STFT stresses that according to this recommendation it is a prerequisite to strictly adhere to the defined equilibrium dialysis procedure, whereas it is permissible to introduce variants in the ID-LC/tandem MS procedure.</p>
</li>
<li>
<p><span><span class="hlt">International</span> Celestial <span class="hlt">Reference</span> Frame (ICRF): mantenimiento y extensión</span></p>
<p>NASA Astrophysics Data System (ADS)</p>
<p>Ma, C.; Arias, E. F.; Eubanks, T.; Fey, A. L.; Gontier, A.-M.; Jacobs, C. S.; Sovers, O. J.; Archinal, B. A.; Charlot, P.</p>
<p></p>
<p>A partir de enero de 1998 el sistema de referencia celeste convencional está representado por el <span class="hlt">International</span> Celestial <span class="hlt">Reference</span> System (ICRS) y materializado a través de las coordenadas VLBI del conjunto de radiofuentes extragalácticas que conforman el <span class="hlt">International</span> Celestial <span class="hlt">Reference</span> Frame (ICRF). La primera realización del ICRF, fue elaborada en 1995 por un grupo de expertos designado por la IAU, la que encomendó al <span class="hlt">International</span> Earth Rotation Service el mantenimiento del ICRS, del ICRF y del vínculo con marcos de referencia en otras frecuencias. Una primera extensión del ICRF se realizó entre abril y junio de 1999, con el objetivo primario de proveer posiciones de radiofuentes extragalácticas observadas a partir de julio de 1995 y de mejorar las posiciones de las fuentes ``candidatas" con la inclusión de observaciones adicionales. Objetivos secundarios fueron monitorear a las radiofuentes para verificar que siguen siendo adecuadas para realizar al ICRF y mejorar las técnicas de análisis de datos. Como resultado del nuevo análisis se obtuvo una solución a partir de la cual se construyó la primera extensión del ICRF, denominada ICRF - Ext.1. Ella representa al ICRS, sus fuentes de definición se mantienen con las mismas posiciones y errores que en la primera realización del ICRF; las demás radiofuentes tienen coordenadas mejor determinadas que en ICRF; el marco de referencia se densificó con el agregado de 59 nuevas radiofuentes.</p>
</li>
<li>
<p><span>Bayesian statistical <span class="hlt">ionospheric</span> tomography improved by incorporating ionosonde measurements</span></p>
<p>NASA Astrophysics Data System (ADS)</p>
<p>Norberg, Johannes; Virtanen, Ilkka I.; Roininen, Lassi; Vierinen, Juha; Orispää, Mikko; Kauristie, Kirsti; Lehtinen, Markku S.</p>
<p>2016-04-01</p>
<p>We validate two-dimensional <span class="hlt">ionospheric</span> tomography reconstructions against EISCAT incoherent scatter radar measurements. Our tomography method is based on Bayesian statistical inversion with prior distribution given by its mean and covariance. We employ ionosonde measurements for the choice of the prior mean and covariance parameters and use the Gaussian Markov random fields as a sparse matrix approximation for the numerical computations. This results in a computationally efficient tomographic inversion algorithm with clear probabilistic interpretation. We demonstrate how this method works with simultaneous beacon satellite and ionosonde measurements obtained in northern Scandinavia. The performance is compared with results obtained with a zero-mean prior and with the prior mean taken from the <span class="hlt">International</span> <span class="hlt">Reference</span> <span class="hlt">Ionosphere</span> 2007 model. In validating the results, we use EISCAT ultra-high-frequency incoherent scatter radar measurements as the ground truth for the ionization profile shape. We find that in comparison to the alternative prior information sources, ionosonde measurements improve the reconstruction by adding accurate information about the absolute value and the altitude distribution of electron density. With an ionosonde at continuous disposal, the presented method enhances stand-alone near-real-time <span class="hlt">ionospheric</span> tomography for the given conditions significantly.</p>
</li>
<li>
<p><span>Dosimetry calculations for <span class="hlt">internal</span> electron sources using a Korean <span class="hlt">reference</span> adult stylised phantom.</span></p>
<p>PubMed</p>
<p>Park, S; Lee, J K; Lee, C; Lee, C</p>
<p>2008-01-01</p>
<p>Absorbed fractions (AFs) and specific absorbed fractions (SAFs) for <span class="hlt">internally</span> deposited electron were calculated using a Korean <span class="hlt">reference</span> adult stylised phantom, where a total of 15 <span class="hlt">internal</span> organ volumes and external body dimension were designed to match average Korean adult male. The walls of oesophagus, stomach, colon and urinary bladder were additionally divided into the mucosal layer and residual wall to accommodate dose calculation for weakly penetrating electron. The mucosal wall thicknesses were determined by the data reported in the <span class="hlt">International</span> Commission on Radiological Protection Publication 89 and other literature resources and by direct measurements. The Monte Carlo transport code MCNPX (version 2.5.0) was employed to calculate the electron energy deposited. The SAFs and AFs for monoenergetic electrons with the energies ranging from 10 keV to 2 MeV were calculated. The results were compared with those of the revised Oak Ridge National Laboratory phantoms and showed considerable differences up to 150% in SAFs, whereas no substantial differences were observed in the AFs.</p>
</li>
<li>
<p><span>Selected Bibliographies and State-of-the-Art Review for Health Manpower Planning. Volume 3: Health Manpower Planning <span class="hlt">References</span>. <span class="hlt">International</span> Health Planning <span class="hlt">Reference</span> Series.</span></p>
<p>ERIC Educational Resources Information Center</p>
<p>White (E.H.) Co., San Francisco, CA.</p>
<p></p>
<p>Intended as a companion piece to volume 3 in the Method Series, Health Manpower Planning (CE 024 231), this third of six volumes in the <span class="hlt">International</span> Health Planning <span class="hlt">Reference</span> Series is a combined literature review and annotated bibliography dealing with health manpower planning for developing countries. The review identifies literature relevant…</p>
</li>
<li>
<p><span>Selected Bibliographies and State-of-the-Art Review for Environmental Health. Volume 2: Environmental Health <span class="hlt">References</span>. <span class="hlt">International</span> Health Planning <span class="hlt">Reference</span> Series.</span></p>
<p>ERIC Educational Resources Information Center</p>
<p>Fraser, Renee White; Shani, Hadasa</p>
<p></p>
<p>Intended as a companion piece to volume 2 in the Method Series, Environmental Health Planning (CE 024 230), this second of six volumes in the <span class="hlt">International</span> Health Planning <span class="hlt">Reference</span> Series is a combined literature review and annotated bibliography dealing with environmental factors in health planning for developing countries. The review identifies…</p>
</li>
<li>
<p><span>Establishment of the first WHO <span class="hlt">international</span> genetic <span class="hlt">reference</span> panel for Prader Willi and Angelman syndromes.</span></p>
<p>PubMed</p>
<p>Boyle, Jennifer; Hawkins, Malcolm; Barton, David E; Meaney, Karen; Guitart, Miriam; O'Grady, Anna; Tobi, Simon; Ramsden, Simon C; Elles, Rob; Gray, Elaine; Metcalfe, Paul; Hawkins, J Ross</p>
<p>2011-08-01</p>
<p>Prader Willi and Angelman syndromes are clinically distinct genetic disorders both mapping to chromosome region 15q11-q13, which are caused by a loss of function of paternally or maternally inherited genes in the region, respectively. With clinical diagnosis often being difficult, particularly in infancy, confirmatory genetic diagnosis is essential to enable clinical intervention. However, the latter is challenged by the complex genetics behind both disorders and the unmet need for characterised <span class="hlt">reference</span> materials to aid accurate molecular diagnosis. With this in mind, a panel of six genotyping <span class="hlt">reference</span> materials for Prader Willi and Angelman syndromes was developed, which should be stable for many years and available to all diagnostic laboratories. The panel comprises three Prader Willi syndrome materials (two with different paternal deletions, and one with maternal uniparental disomy (UPD)) and three Angelman syndrome materials (one with a maternal deletion, one with paternal UPD or an epigenetic imprinting centre defect, and one with a UBE3A point mutation). Genomic DNA was bulk-extracted from Epstein-Barr virus-transformed lymphoblastoid cell lines established from consenting patients, and freeze-dried as aliquots in glass ampoules. In total, 37 laboratories from 26 countries participated in a collaborative study to assess the suitability of the panel. Participants evaluated the blinded, triplicate materials using their routine diagnostic methods against in-house controls or externally sourced uncertified <span class="hlt">reference</span> materials. The panel was established by the Expert Committee on Biological Standardization of the World Health Organization as the first <span class="hlt">International</span> Genetic <span class="hlt">Reference</span> Panel for Prader Willi and Angelman syndromes.</p>
</li>
<li>
<p><span>On the <span class="hlt">Ionospheric</span> Holes of Venus</span></p>
<p>NASA Astrophysics Data System (ADS)</p>
<p>Collinson, G.; Fedorov, A.; Futaana, Y.; Masunaga, K.; Hartle, R. E.; Stenberg, G.; Budnik, E.; Grebowsky, J. M.; Holmstrom, M.; andre, N.; Barabash, S. V.; Zhang, T.</p>
<p>2013-12-01</p>
<p>One of the most intriguing unsolved mysteries that endures from the Pioneer Venus Orbiter is that of ~1000km wide ``Holes" in the nightside <span class="hlt">Ionosphere</span>. The phenomena remains unexplained, despite their frequent observation during the first three years of the mission, and more than thirty years having elapsed since their first description in the literature. We present new observations by the ESA Venus Express of <span class="hlt">Ionospheric</span> Holes at very high altitudes, providing us with the opportunity to study this fascinating phenomena with modern instrumentation. We discuss the insight that these new data give us into the effect of <span class="hlt">Ionospheric</span> Holes on atmospheric escape, and the evidence that suggests that <span class="hlt">Ionospheric</span> Holes are due to an <span class="hlt">internal</span> planetary magnetic field.</p>
</li>
<li>
<p><span>The learning experiences of <span class="hlt">international</span> doctoral students with particular <span class="hlt">reference</span> to nursing students: a literature review.</span></p>
<p>PubMed</p>
<p>Evans, Catrin; Stevenson, Keith</p>
<p>2010-02-01</p>
<p>One of the key challenges for the advancement of nursing globally is the development of doctorally prepared educators and leaders in a context where there is a shortage of provision of doctoral nursing programmes. For the short term future, many nurses wishing to undertake a doctorate will need to complete this education in the USA, the UK or Australia. Very little is known however about the nature of their learning experiences in these countries. This paper presents a literature review on the <span class="hlt">international</span> doctoral student experience, with specific <span class="hlt">reference</span> to nursing. A thorough review of the literature from 1990 to 2009 was undertaken which yielded only three empirical studies related to nursing. The review was then expanded to include subjects other than nursing which yielded 16 studies in total. This paper presents key themes that appear to be generic to <span class="hlt">international</span> doctoral students, and draws out specific implications for nursing. The review found that <span class="hlt">international</span> doctoral students' learning experiences were strongly influenced by the extent to which they could engage with three key elements of doctoral programmes: The first months represented a critical time of transition and most <span class="hlt">international</span> students seemed to want and expect considerable support and structured in-put during this period. Most studies concluded that there was a need for greater institutional support and supervisor training. The three nursing-specific papers were entirely consistent with these themes. The existing evidence is extremely heterogeneous and of variable methodological quality. In order to ensure that doctoral nursing students are getting a high quality and appropriate PhD experience, there is a need for more research specifically with this group. There is also a need to investigate the different stages of the doctoral process in nursing, including, for example, writing up and examination processes and post-doctoral career outcomes.</p>
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<p><span>Evaluation of COMPASS <span class="hlt">ionospheric</span> model in GNSS positioning</span></p>
<p>NASA Astrophysics Data System (ADS)</p>
<p>Wu, Xiaoli; Hu, Xiaogong; Wang, Gang; Zhong, Huijuan; Tang, Chengpan</p>
<p>2013-03-01</p>
<p>As important products of GNSS navigation message, <span class="hlt">ionospheric</span> delay model parameters are broadcasted for single-frequency users to improve their positioning accuracy. GPS provides daily Klobuchar <span class="hlt">ionospheric</span> model parameters based on geomagnetic <span class="hlt">reference</span> frame, while the regional satellite navigation system of China's COMPASS broadcasts an eight-parameter <span class="hlt">ionospheric</span> model, COMPASS <span class="hlt">Ionospheric</span> Model(CIM), which was generated by processing data from continuous monitoring stations, with updating the parameters every 2 h. To evaluate its performance, CIM predictions are compared to <span class="hlt">ionospheric</span> delay measurements, along with GPS positioning accuracy comparisons. Real observed data analysis indicates that CIM provides higher correction precision in middle-latitude regions, but relatively lower correction precision for low-latitude regions where the <span class="hlt">ionosphere</span> has much higher variability. CIM errors for some users show a common bias for in-coming COMPASS signals from different satellites, and hence <span class="hlt">ionospheric</span> model errors are somehow translated into the receivers' clock error estimation. In addition, the CIM from the China regional monitoring network are further evaluated for global <span class="hlt">ionospheric</span> corrections. Results show that in the Northern Hemisphere areas including Asia, Europe and North America, the three-dimensional positioning accuracy using the CIM for <span class="hlt">ionospheric</span> delay corrections is improved by 7.8%-35.3% when compared to GPS single-frequency positioning <span class="hlt">ionospheric</span> delay corrections using the Klobuchar model. However, the positioning accuracy in the Southern Hemisphere is degraded due apparently to the lack of monitoring stations there.</p>
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<p><span>Three-dimensional FDTD Modeling of Earth-<span class="hlt">ionosphere</span> Cavity Resonances</span></p>
<p>NASA Astrophysics Data System (ADS)</p>
<p>Yang, H.; Pasko, V. P.</p>
<p>2003-12-01</p>
<p>Resonance properties of the earth-<span class="hlt">ionosphere</span> cavity were first predicted by W. O. Schumann in 1952 [Schumann, Z. Naturforsch. A, 7, 149, 1952]. Since then observations of extremely low frequency (ELF) signals in the frequency range 1-500 Hz have become a powerful tool for monitoring of global lightning activity and planetary scale variability of the lower <span class="hlt">ionosphere</span>, as well as, in recent years, for location and remote sensing of sprites, jets and elves and associated lightning discharges [e.g., Sato et al., JASTP, 65, 607, 2003; Su et al., Nature, 423, 974, 2003; and <span class="hlt">references</span> cited therein]. The simplicity and flexibility of finite difference time domain (FDTD) technique for finding first principles solutions of electromagnetic problems in a medium with arbitrary inhomogeneities and ever-increasing computer power make FDTD an excellent candidate to be the technique of the future in development of realistic numerical models of VLF/ELF propagation in Earth-<span class="hlt">ionosphere</span> waveguide [Cummer, IEEE Trans. Antennas Propagat., 48, 1420, 2000], and several reports about successful application of the FDTD technique for solution of related problems have recently appeared in the literature [e.g., Thevenot et al., Ann. Telecommun., 54, 297, 1999; Cummer, 2000; Berenger, Ann. Telecommun., 57, 1059, 2002, Simpson and Taflove, IEEE Antennas Wireless Propagat. Lett., 1, 53, 2002]. In this talk we will present results from a new three-dimensional spherical FDTD model, which is designed for studies of ELF electromagnetic signals under 100 Hz in the earth-<span class="hlt">ionosphere</span> cavity. The model accounts for a realistic latitudinal and longitudinal variation of ground conductivity (i.e., for the boundaries between oceans and continents) by employing a broadband surface impedance technique proposed in [Breggs et al., IEEE Trans. Antenna Propagat., 41, 118, 1993]. The realistic distributions of atmospheric/lower <span class="hlt">ionospheric</span> conductivity are derived from the <span class="hlt">international</span> <span class="hlt">reference</span> <span class="hlt">ionosphere</span> model</p>
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<p><span>Evaluation of models proposed for the 1991 revision of the <span class="hlt">International</span> Geomagnetic <span class="hlt">Reference</span> Field</span></p>
<p>USGS Publications Warehouse</p>
<p>Peddie, N.W.</p>
<p>1992-01-01</p>
<p>The 1991 revision of the <span class="hlt">International</span> Geomagnetic <span class="hlt">Reference</span> Field (IGRF) comprises a definitive main-field model for 1985.0, a main-field model for 1990.0, and a forecast secular-variation model for the period 1990-1995. The five 1985.0 main-field models and five 1990.0 main-field models that were proposed have been evaluated by comparing them with one another, with magnetic observatory data, and with Project MAGNET aerial survey data. The comparisons indicate that the main-field models proposed by IZMIRAN, and the secular-variation model proposed jointly by the British Geological Survey and the US Naval Oceanographic Office, should be assigned relatively lower weight in the derivation of the new IGRF models. -Author</p>
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<p><span>Modification of conductivity due to acceleration of the <span class="hlt">ionospheric</span> medium</span></p>
<p>NASA Astrophysics Data System (ADS)</p>
<p>Denisenko, V. V.; Biernat, H. K.; Mezentsev, A. V.; Shaidurov, V. A.; Zamay, S. S.</p>
<p>2008-07-01</p>
<p>A quantitative division of the <span class="hlt">ionosphere</span> into dynamo and motor regions is performed on the base of empirical models of space distributions of <span class="hlt">ionospheric</span> parameters. Pedersen and Hall conductivities are modified to represent an impact of acceleration of the medium because of Ampére's force. It is shown that the currents in the F2 layer are greatly reduced for processes of a few hours duration. This reduction is in particular important for the night-side low-latitude <span class="hlt">ionosphere</span>. The <span class="hlt">International</span> <span class="hlt">Reference</span> <span class="hlt">Ionosphere</span> model is used to analyze the effect quantitatively. This model gives a second high conducting layer in the night-side low-latitude <span class="hlt">ionosphere</span> that reduces the electric field and equatorial electrojets, but intensifies night-side currents during the short-term events. These currents occupy regions which are much wider than those of equatorial electrojets. It is demonstrated that the parameter σd=σP+σHΣH/ΣP that involves the integral Pedersen and Hall conductances ΣP, ΣH ought to be used instead of the local Cowling conductivity σC in calculations of the electric current density in the equatorial <span class="hlt">ionosphere</span>. We may note that Gurevich et al. (1976) derived a parameter similar to σd for more general conditions as those which we discuss in this paper; a more detailed description of this point is given in Sect. 6. Both, σd and σC, appear when a magnetic field line is near a nonconducting domain which means zero current through the boundary of this domain. The main difference between σd and σC is that σd definition includes the possibility for the electric current to flow along a magnetic field line in order to close all currents which go to this line from neighboring ones. The local Cowling conductivity σC corresponds to the current closure at each point of a magnetic field line. It is adequate only for a magnetic field line with constant local conductivity at the whole line when field-aligned currents do not exist because of symmetry, but <div><div><div><h1>I segreti di una dinastia (poco) italiana</h1>
<h2>L&#8217;ascesa dei Savoia tra alleanze di guerra e una rete sapiente di matrimoni europei</h2>
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2 - La scuola di De Amicis
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3 - Civitella del Tronto
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4 - Curtatone e Montanara
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5 - Torre del Greco
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6 - Partinico
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7 - La Savoia
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8 - Trieste
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9 - Porto Empedocle
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10 - Quarto
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11 - Talamone
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12 - Marsala
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13 - Salemi
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14 - Livorno
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15 - Perugia
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16 - Gerace
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17 - Venezia
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18 - S. Maria Capua Vetere
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19 - San Marino
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20 - Gorizia
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21 - Napoli
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22 - Taranto
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23 - Zara
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24 - Roma
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25 - Bronte
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26 - Novara e Vercelli
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27 - San Demetrio Corone
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28 - Trento
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29 - Il Salento
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30 - Friuli
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31 - L'Aquila
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32 - Pontelandolfo
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33 - Sassari
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34 - Pontida
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35 - Milano
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36 - Messina
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37 - Reggio Calabria
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38 - Firenze
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39 - Teano
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40 - Aosta
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41 - Melfi
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42 - Il Molise
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43 - Bologna
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44 - Le Marche
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45 - Caprera
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<p class="reader">Vittorio Emanuele II e il
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