Search results for "Travel"
showing 10 items of 402 documents
The potential for pneumococcal vaccination in Hajj pilgrims: expert opinion.
2013
Hajj is the annual pilgrimage to Mecca in the Kingdom of Saudi Arabia, and is one of the largest mass gathering events in the world. Acute respiratory tract infections are very common during Hajj, primarily as a result of close contact among pilgrims, intense congestion, shared accommodation and air pollution. A number of vaccines are (or have been) recommended for Hajj pilgrims in recent years. Several additional vaccines could significantly reduce the morbidity and mortality at Hajj and should be considered in health recommendations for pilgrims. Pneumococcal vaccines (particularly for those aged >65 years) are widely available, and have been shown to reduce the burden of disease associat…
Interstellar travel guide: Chronicles of a violent universe
2016
In contrast to observations from our local viewpoint, the universe is extremely violent. Explosions of massive stars, X-ray and gamma-ray binary stars, and active galaxies are related to the presence of compact objects such as neutron stars or black holes. Processes such as matter accretion or the formation and release of relativistic plasma jets are responsible for the generation of large amounts of high-energy radiation, caused by the acceleration of elementary particles, and have a significant impact in their surroundings. Moreover, they are related to the generation of gravitational waves: vibrations in spacetime produced by the acceleration of compact massive objects that produce stron…
High energy gamma ray counterparts of astrophysical sources of ultra-high energy cosmic rays
2004
If ultra-high energy cosmic rays (UHECRs) are accelerated at astrophysical point sources, the identification of such sources can be achieved if there is some kind of radiation at observable wavelengths that may be associated with the acceleration and/or propagation processes. No radiation of this type has so far been detected or at least no such connection has been claimed. The process of photopion production during the propagation of UHECRs from the sources to the Earth results in the generation of charged and neutral pions. The neutral (charged) pions in turn decay to gamma quanta and electrons that initiate an electromagnetic cascade in the universal photon background. We calculate the f…
Xrase: The X-Ray Spectroscopic Explorer
2001
The X-Ray Spectroscopic Explorer (XRASE) has a unique combination of features that will make it possible to address many of NASA’s scientific goals. These include how galaxy clusters form, the physics and chemistry of the ISM, the heating of stellar coronae, the amount and content of intergalactic baryonic matter, the mass of black holes and the formation of disks and jets in AGN and galactic binaries. XRASE has a thin foil, multilayered telescope with a large collecting area up to 10 keV, especially in the Fe Kα region (1100 cm2). Its microcalorimeter array combines high energy resolution (7 eV at 6 keV) and efficiency with a field-of-view of 26 arcmin2. A deep orbit allows for long, conti…
2D simulation of wave-particle coupling inspired by walking droplets
2018
In recent years, a fluid dynamics phenomenon has been observed that shows interesting analogies with several quantum mechanical ones. Under specific experimental conditions, a liquid droplet released on a vibrating liquid persists in jumping, forming a localized wave-particle, and its behaviour resembles that of a de Broglie wave-particle. In this paper we discuss a simplified model for this phenomenon and the results of numerical fluid dynamics simulations implemented on the basis of the model. In spite of the relevant simplifying assumptions of our approach, we observe that a wave-droplet coupling is obtained and the droplet travels at nearly constant velocity, as it is observed in experi…
Possibility of measuring the amount of intergalactic metals with 14N VII HFS line
2009
AbstractWe discuss possibility of observations of the warm-hot intergalactic medium using the hyperfine structure line of highly charged nitrogen ion 14N VII (rest wavelength λ = 5.652 mm). Observations of this line will allow to separate bulk and turbulent motions in the observed target and will broaden the information about the gas ionization state, chemical and isotopic composition.Wavelength of this line is well-suited for ground-based observation of objects at z ≈ 0.15 − 0.6 when it is redshifted to the widely-used 6.5 − 9 mm spectral band, and, for example, for z ≥ 1.3, when the line can be observed in 1.3 cm band and at lower frequencies.
Traffic Parameters Estimation to Predict Road Side Pollutant Concentrations using Neural Networks
2007
The analysis aims to evaluate which is the most important among traffic parameters (flows, queues length, occupancy degree, and travel time) to forecast CO and C6H6 concentrations. The study area was identified by Notarbartolo Road and bounded by Liberta Street and Sciuti Street in the urban area of Palermo in Southern Italy. In this area, various loop detectors and one pollution-monitoring site were located. Traffic data related to the pollution-monitoring site immediately near the road link were estimated by Simulation of Urban MObility (SUMO) traffic microsimulator software using as input the flows measured by loop detectors on other links of road network. Traffic and weather data were u…
Ks. Konstantego Damrota opowieść o polskim Pomorzu (na podstawie Szkiców z ziemi i historyi Prus Królewskich z 1886 r.)
2022
Jedną z ważnych postaci Kościoła katolickiego na Pomorzu był ks. Konstanty Damrot (1841–1895) – syn śląskiej ziemi, wybitny literat, wieloletni dyrektor katolickiego seminarium nauczycielskiego w Kościerzynie. Zachwycony pięknem dawnych Prus Królewskich, w 1886 r. wydał pozycję książkową zatytułowaną Szkice z ziemi i historyi Prus Królewskich, Jego zamiarem było nie tylko opisanie piękna nadmorskiej krainy, ale przede wszystkim obudzenie ducha polskiego w tamtejszych mieszkańcach. Poprzez słowo pisane chciał także spopularyzować historię i kulturę nadmorskiej krainy, przesiąkniętej polskością, zbudowaną na wierze katolickiej i rodzimej tradycji. Autor w krótkiej syntezie przedstawia biogram…
Optimal Design of an X-Band, Fully-Coaxial, Easily-Tunable Broadband Power Equalizer for a Microwave Power Module
2020
A microwave power module (MPM), which is a hybrid combination of a solid-state power amplifier (SSPA) as a driver and a traveling-wave tube amplifier (TWT) as the final high power stage, is a high-power device largely used for radar applications. A gain equalizer is often required to flatten the TWT output power gain owing to its big gain fluctuations over the operating frequency range. In this paper, the design of an X-band, fully-coaxial, easily-tunable broadband power equalizer for an MPM is presented. The structure is composed of a coaxial waveguide as the main transmission line and a coaxial cavity loaded with absorbing material as a resonant unit. Sensitivity analyses of the attenuati…
A transdisciplinary educational experience at the Botanical Garden around scientific travelers
2019
In the framework of the transdisciplinary educational innovative project “Sciences and Arts” at the University of Valencia, we present here the design and outcome of an activity around the phenomenon of scientific travelers. It consisted in a scientific-literary tour through the Botanical Garden of the University of Valencia, that 100 students from the subjects “Natural Sciences for teachers” and “Literary training for teachers” attended. The activity was designed as a collaborative work in which scientific travelers served as a pretext to address six educational aspects that the students from each subject tackled in two different ways: from a more scientific than literary approach and vice…