Social media influence on the holiday decision making process in the UK (Generation Y)

This study investigated the influence of social media on Generation Y travellers throughout the holiday decision-making process. The researchers examined the use of social media websites before, during and after holiday, evaluated the level of trust in user-generated content and identified how Generation Y shared their holiday experiences on social media. This study adopted the quantitative/deductive methodology using online questionnaire. The findings suggested that social media platforms were mostly used prior to the holiday as a source of gathering information such as destination, accommodation. However, findings showed although people used social media to search for information, it was less trusted compared to official state tourism websites and word-of-mouth. But the findings showed that social media was also considerably used during the holiday only as medium for posting photos and searching for local entertainment. On the other hand, the results showed that there is a trend of changes toward social media as a source of travel information which indicated respondents’ illingness to use social media for their travel in near future

Interaction of Water-Soluble CdTe Quantum Dots with Bovine Serum Albumin

Semiconductor nanoparticles (quantum dots) are promising fluorescent markers, but it is very little known about interaction of quantum dots with biological molecules. In this study, interaction of CdTe quantum dots coated with thioglycolic acid (TGA) with bovine serum albumin was investigated. Steady state spectroscopy, atomic force microscopy, electron microscopy and dynamic light scattering methods were used. It was explored how bovine serum albumin affects stability and spectral properties of quantum dots in aqueous media. CdTe–TGA quantum dots in aqueous solution appeared to be not stable and precipitated. Interaction with bovine serum albumin significantly enhanced stability and photoluminescence quantum yield of quantum dots and prevented quantum dots from aggregating

Search for magnetically-induced signatures in the arrival directions of ultra-high-energy cosmic rays measured at the Pierre Auger Observatory

We search for signals of magnetically-induced effects in the arrival directions of ultra-high-energy cosmic rays detected at the Pierre Auger Observatory. We apply two different methods. One is a search for sets of events that show a correlation between their arrival direction and the inverse of their energy, which would be expected if they come from the same point-like source, they have the same electric charge and their deflection is relatively small and coherent. We refer to these sets of events as multiplets . The second method, called thrust , is a principal axis analysis aimed to detect the elongated patterns in a region of interest. We study the sensitivity of both methods using a benchmark simulation and we apply them to data in two different searches. The first search is done assuming as source candidates a list of nearby active galactic nuclei and starburst galaxies. The second is an all-sky blind search. We report the results and we find no statistically significant features. We discuss the compatibility of these results with the indications on the mass composition inferred from data of the Pierre Auger Observatory

Design, upgrade and characterization of the silicon photomultiplier front-end for the AMIGA detector at the Pierre Auger Observatory

AMIGA (Auger Muons and Infill for the Ground Array) is an upgrade of the Pierre Auger Observatory to complement the study of ultra-high-energy cosmic rays (UHECR) by measuring the muon content of extensive air showers (EAS). It consists of an array of 61 water Cherenkov detectors on a denser spacing in combination with underground scintillation detectors used for muon density measurement. Each detector is composed of three scintillation modules, with 10 m2 detection area per module, buried at 2.3 m depth, resulting in a total detection area of 30 m2. Silicon photomultiplier sensors (SiPM) measure the amount of scintillation light generated by charged particles traversing the modules. In this paper, the design of the front-end electronics to process the signals of those SiPMs and test results from the laboratory and from the Pierre Auger Observatory are described. Compared to our previous prototype, the new electronics shows a higher performance, higher efficiency and lower power consumption, and it has a new acquisition system with increased dynamic range that allows measurements closer to the shower core. The new acquisition system is based on the measurement of the total charge signal that the muonic component of the cosmic ray shower generates in the detector

Measurement of the Fluctuations in the Number of Muons in Extensive Air Showers with the Pierre Auger Observatory

We present the first measurement of the fluctuations in the number of muons in extensive air showers produced by ultrahigh energy cosmic rays. We find that the measured fluctuations are in good agreement with predictions from air shower simulations. This observation provides new insights into the origin of the previously reported deficit of muons in air shower simulations and constrains models of hadronic interactions at ultrahigh energies. Our measurement is compatible with the muon deficit originating from small deviations in the predictions from hadronic interaction models of particle production that accumulate as the showers develop.Fil: Aab, A.. Radboud Universiteit Nijmegen; Países BajosFil: Abreu, P.. Instituto Superior Tecnico; PortugalFil: Aglietta, M.. Osservatorio Astrofisico di Torino; Italia. Istituto Nazionale di Astrofisica; Italia. Istituto Nazionale di Fisica Nucleare; ItaliaFil: Albury, J. M.. University of Adelaide; AustraliaFil: Allekotte, Ingomar. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Almela, Daniel Alejandro. Universidad Tecnológica Nacional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Tecnología en Detección y Astropartículas. Comisión Nacional de Energía Atómica. Instituto de Tecnología en Detección y Astropartículas. Universidad Nacional de San Martín. Instituto de Tecnología en Detección y Astropartículas; ArgentinaFil: Alvarez Muñiz, J.. Universidad de Santiago de Compostela; EspañaFil: Alves Batista, R.. Radboud Universiteit Nijmegen; Países BajosFil: Anastasi, G. A.. Università di Torino; Italia. Istituto Nazionale di Fisica Nucleare; ItaliaFil: Anchordoqui, L.. University of New York; Estados UnidosFil: Andrada, María Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Tecnología en Detección y Astropartículas. Comisión Nacional de Energía Atómica. Instituto de Tecnología en Detección y Astropartículas. Universidad Nacional de San Martín. Instituto de Tecnología en Detección y Astropartículas; ArgentinaFil: Andringa, S.. Instituto Superior Tecnico; PortugalFil: Aramo, C.. Istituto Nazionale di Fisica Nucleare; ItaliaFil: Araújo Ferreira, P. R.. Rwth Aachen University; AlemaniaFil: Asorey, Hernán Gonzalo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Tecnología en Detección y Astropartículas. Comisión Nacional de Energía Atómica. Instituto de Tecnología en Detección y Astropartículas. Universidad Nacional de San Martín. Instituto de Tecnología en Detección y Astropartículas; ArgentinaFil: Assis, P.. Instituto Superior Tecnico; PortugalFil: Avila, Gualberto. Observatorio Pierre Auger. Observatorio Sur - Malargue; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Badescu, A. M.. University Politehnica of Bucharest; RumaniaFil: Bakalova, A.. Czech Academy of Sciences; República ChecaFil: Balaceanu, A.. “Horia Hulubei” National Institute for Physics and Nuclear Engineering; RumaniaFil: Barbato, F.. Università degli Studi di Napoli Federico II; Italia. Istituto Nazionale di Fisica Nucleare; ItaliaFil: Barreira Luz, R. J.. Instituto Superior Técnico; PortugalFil: Becker, K. H.. Bergische Universität Wuppertal; AlemaniaFil: Bellido, J. A.. University of Adelaide; AustraliaFil: Berat, C.. Universite Grenoble Alpes; Francia. Centre National de la Recherche Scientifique; FranciaFil: Bertaina, M. E.. Università di Torino; Italia. Istituto Nazionale di Fisica Nucleare; ItaliaFil: Bertou, Xavier Pierre Louis. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Area Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche). Grupo de Partículas y Campos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Biermann, P. L.. Max-Planck-Institut für Radioastronomie; AlemaniaFil: Bister, T.. Aachen University; AlemaniaFil: Mollerach, Maria Silvia. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche); Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentin

Design, upgrade and characterization of the silicon photomultiplier front-end for the AMIGA detector at the Pierre Auger Observatory

AMIGA (Auger Muons and Infill for the Ground Array) is an upgrade of the Pierre Auger Observatory to complement the study of ultra-high-energy cosmic rays (UHECR) by measuring the muon content of extensive air showers (EAS). It consists of an array of 61 water Cherenkov detectors on a denser spacing in combination with underground scintillation detectors used for muon density measurement. Each detector is composed of three scintillation modules, with 10 m2 detection area per module, buried at 2.3 m depth, resulting in a total detection area of 30 m2 . Silicon photomultiplier sensors (SiPM) measure the amount of scintillation light generated by charged particles traversing the modules. In this paper, the design of the front-end electronics to process the signals of those SiPMs and test results from the laboratory and from the Pierre Auger Observatory are described. Compared to our previous prototype, the new electronics shows a higher performance, higher efficiency and lower power consumption, and it has a new acquisition system with increased dynamic range that allows measurements closer to the shower core. The new acquisition system is based on the measurement of the total charge signal that the muonic component of the cosmic ray shower generates in the detector.Fil: Aab, A.. Radboud Universiteit Nijmegen; Países BajosFil: Abreu, P.. Instituto Superior Tecnico; PortugalFil: Aglietta, M.. Istituto Nazionale di Astrofisica; Italia. Istituto Nazionale di Fisica Nucleare; ItaliaFil: Albury, J. M.. University of Adelaide; AustraliaFil: Allekotte, Ingomar. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Almela, A.. Universidad Nacional de San Martín; Argentina. Universidad Tecnológica Nacional; ArgentinaFil: Alvarez Muñiz, J.. Universidad de Santiago de Compostela; EspañaFil: Alves Batista, R.. Radboud Universiteit Nijmegen; Países BajosFil: Anastasi, G. A.. Università di Torino; Italia. Istituto Nazionale di Fisica Nucleare; ItaliaFil: Anchordoqui, Luis A.. City University of New York; Estados UnidosFil: Andrada, Betiana Eugenia. Universidad Nacional de San Martín; ArgentinaFil: Andringa, S.. Instituto Superior Tecnico; PortugalFil: Aramo, C.. Istituto Nazionale di Fisica Nucleare; ItaliaFil: Araújo Ferreira, P. R.. Rwth Aachen University; AlemaniaFil: Asorey, H.. Universidad Nacional de San Martín; ArgentinaFil: Assis, P.. Instituto Superior Tecnico; PortugalFil: Avila, G.. Observatorio Pierre Auger; ArgentinaFil: Badescu, A. M.. University Politehnica Of Bucharest; RumaniaFil: Bakalova, A.. The Czech Academy Of Sciences; República ChecaFil: Balaceanu, A.. “Horia Hulubei” National Institute for Physics and Nuclear Engineering, Bucharest-Magurele; RumaniaFil: Barbato, F.. Università degli Studi di Napoli Federico II; Italia. Istituto Nazionale di Fisica Nucleare; ItaliaFil: Barreira Luz, R. J.. Instituto Superior Tecnico; PortugalFil: Becker, K. H.. Bergische Universität Wuppertal; AlemaniaFil: Bellido, J. A.. University of Adelaide; AustraliaFil: Berat, C.. Universite Grenoble Alpes; FranciaFil: Bertaina, M. E.. Università di Torino; Italia. Istituto Nazionale di Fisica Nucleare; ItaliaFil: Bertou, Xavier Pierre Louis. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Biermann, P. L.. Max Planck Institute For Radio Astronomy; AlemaniaFil: Bister, T.. Rwth Aachen University; AlemaniaFil: Gollan Scilipotti, Fernando Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Tecnología en Detección y Astropartículas. Comisión Nacional de Energía Atómica. Instituto de Tecnología en Detección y Astropartículas. Universidad Nacional de San Martín. Instituto de Tecnología en Detección y Astropartículas; Argentin

Calibration of the underground muon detector of the Pierre Auger Observatory

To obtain direct measurements of the muon content of extensive air showers with energy above 101 eV, the Pierre Auger Observatory is currently being equipped with an underground muon detector (UMD), consisting of 219 10 m2-modules, each segmented into 64 scintillators coupled to silicon photomultipliers (SiPMs). Direct access to the shower muon content allows for the study of both of the composition of primary cosmic rays and of high-energy hadronic interactions in the forward direction. As the muon density can vary between tens of muons per m close to the intersection of the shower axis with the ground to much less than one per m when far away, the necessary broad dynamic range is achieved by the simultaneous implementation of two acquisition modes in the read-out electronics: the binary mode, tuned to count single muons, and the ADC mode, suited to measure a high number of them. In this work, we present the end-to-end calibration of the muon detector modules: first, the SiPMs are calibrated by means of the binary channel, and then, the ADC channel is calibrated using atmospheric muons, detected in parallel to the shower data acquisition. The laboratory and field measurements performed to develop the implementation of the full calibration chain of both binary and ADC channels are presented and discussed. The calibration procedure is reliable to work with the high amount of channels in the UMD, which will be operated continuously, in changing environmental conditions, for several years.Fil: Aab, A.. Radboud Universiteit Nijmegen; Países BajosFil: Abreu, P.. Instituto Superior Tecnico; PortugalFil: Aglietta, M.. Istituto Nazionale di Astrofisica; Italia. Istituto Nazionale di Fisica Nucleare; ItaliaFil: Albury, J. M.. University of Adelaide; AustraliaFil: Allekotte, Ingomar. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Almela, A.. Universidad Tecnológica Nacional; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Alvarez Muñiz, J.. Universidad de Santiago de Compostela; EspañaFil: Alves Batista, R.. Radboud Universiteit Nijmegen; Países BajosFil: Anastasi, G. A.. Università di Torino; Italia. Istituto Nazionale di Fisica Nucleare; ItaliaFil: Anchordoqui, Luis A.. City University of New York; Estados UnidosFil: Andrada, B.. Comisión Nacional de Energía Atómica; ArgentinaFil: Andringa, S.. Instituto Superior Tecnico; PortugalFil: Aramo, C.. Istituto Nazionale di Fisica Nucleare; ItaliaFil: Araújo Ferreira, P. R.. Rwth Aachen University; AlemaniaFil: Arteaga Velázquez, J. C.. Universidad Michoacana de San Nicolás de Hidalgo; MéxicoFil: Asorey, Hernán Gonzalo. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Assis, P.. Instituto Superior Tecnico; PortugalFil: Avila, G.. Comisión Nacional de Energía Atómica; ArgentinaFil: Badescu, A.M.. University Politehnica Of Bucharest; RumaniaFil: Bakalova, A.. Institute Of Physics Of The Czech Academy Of Sciences; República ChecaFil: Balaceanu, A.. “Horia Hulubei” National Institute for Physics and Nuclear Engineering; RumaniaFil: Barbato, F.. Laboratori Nazionali del Gran Sasso; Italia. Gran Sasso Science Institute; ItaliaFil: Barreira Luz, R. J.. Instituto Superior Tecnico; PortugalFil: Becker, K. H.. Bergische Universität Wuppertal; AlemaniaFil: Bellido, J. A.. Universidad Nacional de San Agustin de Arequipa; Perú. University of Adelaide; AustraliaFil: Berat, C.. Universite Grenoble Alpes; FranciaFil: Bertaina, M. E.. Università di Torino; Italia. Istituto Nazionale di Fisica Nucleare; ItaliaFil: Bertou, Xavier Pierre Louis. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Biermann, P. L.. Max Planck Institute For Radio Astronomy; AlemaniaFil: Gollan Scilipotti, Fernando Daniel. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

The FRAM robotic telescope for atmospheric monitoring at the Pierre Auger Observatory

FRAM (F/Photometric Robotic Atmospheric Monitor) is a robotic telescope operated at the Pierre Auger Observatory in Argentina for the purposes of atmospheric monitoring using stellar photometry. As a passive system which does not produce any light that could interfere with the observations of the fluorescence telescopes of the observatory, it complements the active monitoring systems that use lasers. We discuss the applications of stellar photometry for atmospheric monitoring at optical observatories in general and the particular modes of operation employed by the Auger FRAM. We describe in detail the technical aspects of FRAM, the hardware and software requirements for a successful operation of a robotic telescope for such a purpose and their implementation within the FRAM system

Calibration of the underground muon detector of the Pierre Auger Observatory

To obtain direct measurements of the muon content of extensive air showers with energy above 101 eV, the Pierre Auger Observatory is currently being equipped with an underground muon detector (UMD), consisting of 219 10 m2-modules, each segmented into 64 scintillators coupled to silicon photomultipliers (SiPMs). Direct access to the shower muon content allows for the study of both of the composition of primary cosmic rays and of high-energy hadronic interactions in the forward direction. As the muon density can vary between tens of muons per m close to the intersection of the shower axis with the ground to much less than one per m when far away, the necessary broad dynamic range is achieved by the simultaneous implementation of two acquisition modes in the read-out electronics: the binary mode, tuned to count single muons, and the ADC mode, suited to measure a high number of them. In this work, we present the end-to-end calibration of the muon detector modules: first, the SiPMs are calibrated by means of the binary channel, and then, the ADC channel is calibrated using atmospheric muons, detected in parallel to the shower data acquisition. The laboratory and field measurements performed to develop the implementation of the full calibration chain of both binary and ADC channels are presented and discussed. The calibration procedure is reliable to work with the high amount of channels in the UMD, which will be operated continuously, in changing environmental conditions, for several years

Studies on the response of a water-Cherenkov detector of the Pierre Auger Observatory to atmospheric muons using an RPC hodoscope

Extensive air showers, originating from ultra-high energy cosmic rays, have been successfully measured through the use of arrays of water-Cherenkov detectors (WCDs). Sophisticated analyses exploiting WCD data have made it possible to demonstrate that shower simulations, based on different hadronic-interaction models, cannot reproduce the observed number of muons at the ground. The accurate knowledge of the WCD response to muons is paramount in establishing the exact level of this discrepancy. In this work, we report on a study of the response of a WCD of the Pierre Auger Observatory to atmospheric muons performed with a hodoscope made of resistive plate chambers (RPCs), enabling us to select and reconstruct nearly 600 thousand single muon trajectories with zenith angles ranging from 0 to 55. Comparison of distributions of key observables between the hodoscope data and the predictions of dedicated simulations allows us to demonstrate the accuracy of the latter at a level of 2%. As the WCD calibration is based on its response to atmospheric muons, the hodoscope data are also exploited to show the long-term stability of the procedure