The aim of this article is to review the research conducted in the field of aqueous and polymer composites cellulose nanocrystal (CNC) gels. The experimental techniques employed to characterize the ...rheological behavior of these materials will be summarized, and the main advantages of using CNC gels will also be addressed in this review. In addition, research devoted to the use of numerical simulation methodologies to describe the production of CNC-based materials, e.g., in 3D printing, is also discussed. Finally, this paper also discusses the application of CNC gels along with additives such as cross-linking agents, which can represent an enormous opportunity to develop improved materials for manufacturing processes.
The Argo-YBJ experiment has now reached its final design configuration. The detector system consists of a full coverage array (about 5800 square meters) of resistive plate chambers (RPCs). The ...throughput depends on the trigger rate and threshold. The DAQ system must be able to sustain a maximum transfer rate of the order of 15 MB/s and a high peak data flow. Data are read out using a typical front-end acquisition chain built around a custom bus. Specialized electronics have been designed and dedicated software has been written to perform this task. Data are sent to the online farm through a switch exploiting a gigabit ethernet protocol. A solution to transfer data from the YBJ laboratory to the laboratories belonging to the Argo-YBJ collaboration exploiting the GRID middleware has also been implemented. In this paper we describe the daq and the data mover main characteristics and performance.
Layout and performance of RPCs used in the Argo-YBJ experiment Aielli, G.; Assiro, R.; Bacci, C. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2006, Letnik:
562, Številka:
1
Journal Article
Recenzirano
The layout of the RPCs, used in the Argo-YBJ experiment to image with a high space-time granularity the atmospheric shower, is described in this paper. The detector has been assembled to provide both ...digital and analog informations in order to cover a wide particle density range with a time accuracy of 1
ns. The experimental results obtained operating the chambers in streamer mode at sea level with a standard gas mixture are presented.
Temperature effect on RPC performance in the ARGO-YBJ experiment Aielli, G.; Bacci, C.; Bartoli, B. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2009, Letnik:
608, Številka:
2
Journal Article
Recenzirano
The ARGO-YBJ experiment has been taking data for nearly 2 years. In order to monitor continuously the performance of the Resistive Plate Chamber detectors and to study the daily temperature effects ...on the detector performance, a cosmic ray muon telescope was setup near the carpet detector array in the ARGO-YBJ laboratory. Based on the measurements performed using this telescope, it is found that, at the actual operating voltage of 7.2
kV, the temperature effect on the RPC time resolution is about
0.04
ns
/
∘
C
and on the particle detection efficiency is about
0.03
%
/
∘
C
. Based on these figures we conclude that the environmental effects do not affect substantially the angular resolution of the ARGO-YBJ detector.
The ARGO-YBJ experiment has been designed to study the extensive air showers with an energy threshold lower than that of the existing arrays by exploiting the high altitude location (4300
m a.s.l. in ...Tibet, PR China) and the full ground plane coverage. The lower energy limit of the detector (
E
∼
1
GeV) is reached by the scaler mode technique, i.e. recording the counting rate at fixed time intervals. At these energies, transient signals due to local (e.g. Forbush decreases) and cosmological (e.g. Gamma ray bursts) phenomena are expected as a significant variation of the counting rate compared to the background. In this paper, the performance of the ARGO-YBJ detector operating in scaler mode is described and discussed.
Highlights from the ARGO-YBJ experiment Aielli, G.; Bacci, C.; Bartoli, B. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
2012, 2012-1-00, Letnik:
661
Journal Article
Recenzirano
Odprti dostop
The ARGO-YBJ experiment at YangBaJing in Tibet (4300
m a.s.l.) has been taking data with its full layout since October 2007. Here we present a few significant results obtained in gamma-ray astronomy ...and cosmic-ray physics. Emphasis is placed on the analysis of gamma-ray emission from point-like sources (Crab Nebula, MRK 421), on the preliminary limit on the antiproton/proton flux ratio, on the large-scale cosmic-ray anisotropy and on the proton–air cross-section. The performance of the detector is also discussed, and the perspectives of the experiment are outlined.
Calibration of the RPC charge readout in the ARGO-YBJ experiment Aielli, G.; Bacci, C.; Bartoli, B. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
2012, 2012-1-00, Letnik:
661
Journal Article
Recenzirano
Odprti dostop
The charge readout of Resistive Plate Chambers (RPCs) is implemented in the ARGO-YBJ experiment to measure the charged particle density of the shower front up to 10
4/m
2, enabling the study of the ...primary cosmic rays with energies in the “knee” region. As the first time for RPCs being used this way, a telescope with RPCs and scintillation detectors is setup to calibrate the number of charged particles hitting a RPC versus its charge readout. Air shower particles are taken as the calibration beam. The telescope was tested at sea level and then moved to the ARGO-YBJ site for coincident operation with the ARGO-YBJ experiment. The charge readout shows good linearity with the particle density in the dynamic range (up to 200/m
2).
The ARGO-YBJ (Astrophysical Radiation Ground-based Observatory at YangBaJing) experiment is designed for very high energy γ-astronomy and cosmic ray researches. Due to the full coverage of a large ...area (5600
m
2) with resistive plate chambers at a very high altitude (4300
m a.s.l.), the ARGO-YBJ detector is used to search for transient phenomena, such as Gamma-ray bursts (GRBs). Because the ARGO-YBJ detector has a large field of view (∼2
sr) and is operated with a high duty cycle (>90%), it is well suited for GRB surveying and can be operated in searches for high energy GRBs following alarms set by satellite-borne observations at lower energies. In this paper, the sensitivity of the ARGO-YBJ detector for GRB detection is estimated. Upper limits to fluence with 99% confidence level for 26 GRBs inside the field of view from June 2006 to January 2009 are set in the two energy ranges 10–100
GeV and 10
GeV–1
TeV.
Climate changes in the Iberian Peninsula since the Last Glacial Maximum are associated with distributional shifts of major Mediterranean and European temperate species. The dynamic relationship ...between climate and species in the past may be retrieved from the fossil records available in the Iberian Peninsula. We have used an extensive set of pollen records to reconstruct spatial layers (1 kyr interval) of January minimum temperature, July maximum temperature, and annual precipitation over the time period between 15 and 3 ka. A functional principal component analysis was used to summarise the spatial evolution of climate in areas that share similar climate trends. When compared between them, the identified four areas show different climate trends over the studied period and are coherent with the existence of multiple refugial areas within the Iberian Peninsula.
We report on the search for gamma ray bursts (GRBs) in the energy range 1-100 GeV in coincidence with the prompt emission detected by satellites using the Astrophysical Radiation with Ground-based ...Observatory at YangBaJing (ARGO-YBJ) air shower detector. Thanks to its mountain location (Yangbajing, Tibet, People's Republic of China, 4300 m above sea level), active surface ({approx}6700 m{sup 2} of Resistive Plate Chambers), and large field of view ({approx}2 sr, limited only by the atmospheric absorption), the ARGO-YBJ air shower detector is particularly suitable for the detection of unpredictable and short duration events such as GRBs. The search is carried out using the 'single particle technique', i.e., counting all the particles hitting the detector without measurement of the energy and arrival direction of the primary gamma rays. Between 2004 December 17 and 2009 April 7, 81 GRBs detected by satellites occurred within the field of view of ARGO-YBJ (zenith angle {theta} {<=} 45 deg.). It was possible to examine 62 of these for >1 GeV counterpart in the ARGO-YBJ data finding no statistically significant emission. With a lack of detected spectra in this energy range fluence upper limits are profitable, especially when the redshift is known and the correction for the extragalactic absorption can be considered. The obtained fluence upper limits reach values as low as 10{sup -5} erg cm{sup -2} in the 1-100 GeV energy region. Besides this individual search for a higher energy counterpart, a statistical study of the stack of all the GRBs both in time and in phase was made, looking for a common feature in the GRB high-energy emission. No significant signal has been detected.
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