3,587 research outputs found
Spin observables for pion photoproduction on the deuteron in the (1232)-resonance region
Spin observables for the three charge states of the pion for the pion
photoproduction reaction on the deuteron, , with polarized
photon beam and/or oriented deuteron target are predicted. For the beam-target
double-spin asymmetries, it is found that only the longitudinal asymmetries
and do not vanish, whereas all the circular
and the other longitudinal asymmetries do vanish. The sensitivity of spin
observables to the model deuteron wave function is investigated. It has been
found that only and are sensitive to the model deuteron wave
function, in particular in the case of -production above the
-region, and that other asymmetries are not.Comment: 16 pages, 8 figures, accepted for publication in J. Phys. G: Nucl.
Part. Phy
Polarization observables of the gamma d --> PiNN reaction in the Delta(1232)-resonance region
Polarization observables of the three charge states of the pion for the
reaction with polarized photon beam and/or oriented
deuteron target are evaluated over the whole (1232)-resonance region
adopting a nonrelativistic model based on time-ordered perturbation theory.
Results for the -meson spectra, linear photon asymmetry, vector and tensor
target asymmetries are presented. Particular attention is given, for the first
time, to double polarization asymmetries for which we present results for
and . We found that all other double
polarization asymmetries of photon and deuteron target are vanished.Comment: 17 Pages, 8 Figures, accepted for publication in Int. J. Mod. Phys.
Mean parity of single quantum excitation of some optical fields in thermal environments
The mean parity (the Wigner function at the origin) of excited binomial
states, excited coherent states and excited thermal states in thermal channel
is investigated in details. It is found that the single-photon excited binomial
state and the single-photon excited coherent state exhibit certain similarity
in the aspect of their mean parity in the thermal channel. We show the negative
mean parity can be regarded as an indicator of nonclassicality of single-photon
excitation of optical fields with a little coherence, especially for the
single-photon excited thermal states.Comment: 4 pages, 4 figures, RevTex4; PACS numbers: 42.50.Dv, 03.65.Yz,
05.40.Ca; Three typo errors have been correcte
Dosimetric Comparison between Coplanar and Non-Coplanar Fields in Irradiation of Middle and Lower Lobes Lung Tumors
Abstract Purpose: To compare between the coplanar and non-coplanar fields regarding planning target volume (PTV) coverage, conformity index and preservation of organs at risk (heart-lungs-esophagus and spinal cord). Materials and Methods: 10 patients presented with stage IIIA or IIIB NSCLC with a tumor located in the middle or lower lobes. Because of this location, the heart is one of the main organs at risk. Two plans, coplanar and non-coplanar 3 dimensional conformal radiotherapy plans are performed for each patient. All treatment plans are created using Xio -Computerized medical system treatment planning system. The prescribed dose is 64 Gy in 32 fractions. Results: For both plans, the maximum dose to the PTV doesn't exceed 110% of the prescribed dose; the 95% isodose (60.8 Gy) covers at least 95% of the PTV volume and the mean conformity index values are also very similar 0.59 vs 0.61 for coplanar and non-coplanar plans respectively without statistically significant difference (P = 0.1711). Regarding organs at risk, large advantage for adding a non-coplanar field in the preservation of the heart is observed. The mean V30 values for noncoplanar plan are 17.3 Gy versus 28.9 Gy for the coplanar plan with statistically significant difference (P = 0.0060). Also, the mean V40 and V50 values for the non coplanar compared to coplanar plan are 12.6 Gy and 7.9 Gy versus 23.1 Gy and 14.9 Gy respectively, and these differences are statistically significant (P = 0.0162) (P = 0.0084). No statistically significant differences are found between coplanar and non-coplanar plans for lungs, esophagus or the spinal cord. Conclusion: Using non-coplanar beams in the irradiation of middle and lower lung tumors significantly reduces the radiation dose to the heart with the same target volume coverage and conformity index
Assessment of magmatic versus post-magmatic processes in the Mueilha rare-metal granite, Eastern Desert of Egypt, Arabian-Nubian Shield
The Mueilha rare-metal granite, exposed in the central Eastern Desert of Egypt, is a post-collisional intrusion that formed in the final magmatic stage of the evolution of the Arabian-Nubian Shield. The Mueilha intrusion was emplaced as a high-level magmatic cupola into metamorphic country rocks. It consists of two cogenetic intrusive bodies: an early phase emplaced at shallow depth and now penetratively altered to white albite granite and a later phase of red granites emplaced at greater depth that better preserve magmatic features. The albite granite is less common and represents the upper margin of the Mueilha intrusion, the apex of the magmatic cupola. The red granites are volumetrically dominant and appears to have crystallized from the margins inward, forming a composite pluton zoned from muscovite granite to alkali feldspar granite. All parts of the Mueilha pluton appear to have been emplaced within a short time interval, before complete crystallization of the earliest phase. The geochemistry of the Mueilha granites is typical of rare-metal granites, characterized by high SiO₂, Na₂O + K₂O, Nb, Rb, Ta, Y, U, Th, Sn, and W with depletion in P, Mg, Ti, Sr and Ba. They are weakly peraluminous and highly fractionated with A-type character. The chondrite-normalized REE patterns have strongly negative Eu anomalies, typical of highly differentiated granites that evolved through a transitional magmatic–hydrothermal stage. The primary magma feeding the Mueilha intrusion was generated by partial melting of the juvenile crust of the Arabian-Nubian Shield; it subsequently underwent extensive fractional crystallization and metasomatism by late- to post-magmatic fluids. Separation of fluids from the oversaturated melt promoted both diffuse greisenization and focused segregation of pegmatite and fluorite and quartz veins. Alkalis liberated from feldspars consumed by greisenization were redeposited during albitization in the uppermost part of the magma chamber. Despite penetration of the intrusion boundary by discrete dikes, veins, and aphophyses, diffuse alteration of the metamorphic country rocks is not apparent. Primary columbite-series minerals crystallized from the melt and were later partly replaced by secondary Nb and Ta minerals (fluorcalciomicrolite and wodginite) during hydrothermal alteration
The patient safety practices of emergency medical teams in disaster zones: a systematic analysis
Introduction: Disaster zone medical relief has been criticised for poor quality care, lack of standardisation and accountability. Traditional patient safety practices of Emergency Medical Teams (EMT) in disaster zones were not well understood. Improving the quality of healthcare in disaster zones has gained importance within global health policy. Ascertaining patient safety practices of EMTs in disaster zones may identify areas of practice that can be improved. Methods: A systematic search of OvidSP, Embase and Medline databases, key journals of interest, key grey-literature texts, the databases of the World Health Organisation (WHO), MĂ©decins Sans Frontieres (MSF) and the International Committee of the Red Cross (ICRC), and Google Scholar were performed. Descriptive studies, case reports, case series, prospective trials and opinion pieces were included with no limitation on date or language of publication. Results: There were 9,685 records, evenly distributed between the peer-reviewed and grey literature. Of these, 30 studies and 9 grey literature texts met the inclusion criteria and underwent qualitative synthesis. From these articles, 302 patient safety statements were extracted. Thematic analysis categorised these statements into 84 themes (total frequency 632). The most frequent themes were limb injury (9%), medical records (5.4%), surgery decision making (4.6%), medicines safety (4.4%) and protocol (4.4%) Conclusion: Patient safety practices of EMTs in disaster zones are weighted towards acute clinical care, particularly surgery. The management of Non-Communicable Disease (NCD) is underrepresented. There is widespread recognition of the need to improve medical record keeping. High-quality data and institutional level patient safety practices are lacking. There is no consensus on disaster zone specific performance indicators. These deficiencies represent opportunities to improve patient safety in disaster zones
CMS Software Distribution on the LCG and OSG Grids
The efficient exploitation of worldwide distributed storage and computing
resources available in the grids require a robust, transparent and fast
deployment of experiment specific software. The approach followed by the CMS
experiment at CERN in order to enable Monte-Carlo simulations, data analysis
and software development in an international collaboration is presented. The
current status and future improvement plans are described.Comment: 4 pages, 1 figure, latex with hyperref
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Investigation of Mn Implanted LiNbO{sub 3} applying electron paramagnetic resonance technique
The effect of ion implantation on the LiNbO{sub 3} crystal is studied using electron paramagnetic resonance spectroscopy (EPR). EPR measurements on these crystals were performed as a function of ion species Mn and Fe and fluence at room temperature. Also the effect of the laser illumination on the EPR signal was determined by illuminating the crystal in situ and measuring the decay and growth of the EPR signal. LiNbO{sub 3}:Mn{sup 2+} at a depth of approximately 200 nm was formed by implantation of 2.5 {times} 10{sup 14} Mncm{sup 2} and 1 {times} 10{sup 17} Mn/cm{sup 2} at 2 MeV. The implanted samples were compared with bulk doped crystals. It was found that the decay and growth of Mn EPR for the implanted crystal is very small compared with the bulk doped LiNbO{sub 3}:Mn crystal. This was found to be primarily due to the spin concentration on the crystals. On the other, hand the decay time of the high fluence is about 40% slower than the decay of the low fluence implanted crystal
EveTAR: Building a Large-Scale Multi-Task Test Collection over Arabic Tweets
This article introduces a new language-independent approach for creating a
large-scale high-quality test collection of tweets that supports multiple
information retrieval (IR) tasks without running a shared-task campaign. The
adopted approach (demonstrated over Arabic tweets) designs the collection
around significant (i.e., popular) events, which enables the development of
topics that represent frequent information needs of Twitter users for which
rich content exists. That inherently facilitates the support of multiple tasks
that generally revolve around events, namely event detection, ad-hoc search,
timeline generation, and real-time summarization. The key highlights of the
approach include diversifying the judgment pool via interactive search and
multiple manually-crafted queries per topic, collecting high-quality
annotations via crowd-workers for relevancy and in-house annotators for
novelty, filtering out low-agreement topics and inaccessible tweets, and
providing multiple subsets of the collection for better availability. Applying
our methodology on Arabic tweets resulted in EveTAR , the first
freely-available tweet test collection for multiple IR tasks. EveTAR includes a
crawl of 355M Arabic tweets and covers 50 significant events for which about
62K tweets were judged with substantial average inter-annotator agreement
(Kappa value of 0.71). We demonstrate the usability of EveTAR by evaluating
existing algorithms in the respective tasks. Results indicate that the new
collection can support reliable ranking of IR systems that is comparable to
similar TREC collections, while providing strong baseline results for future
studies over Arabic tweets
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