898 research outputs found
Multi-mode TES bolometer optimization for the LSPE-SWIPE instrument
In this paper we explore the possibility of using transition edge sensor
(TES) detectors in multi-mode configuration in the focal plane of the Short
Wavelength Instrument for the Polarization Explorer (SWIPE) of the
balloon-borne polarimeter Large Scale Polarization Explorer (LSPE) for the
Cosmic Microwave Background (CMB) polarization. This study is motivated by the
fact that maximizing the sensitivity of TES bolometers, under the augmented
background due to the multi-mode design, requires a non trivial choice of
detector parameters. We evaluate the best parameter combination taking into
account scanning strategy, noise constraints, saturation power and operating
temperature of the cryostat during the flight.Comment: in Journal of Low Temperature Physics, 05 January 201
Comparative analysis between subjective and instrumental quality assessment through advanced technology: a pilot study on tennis serve
The purpose of this study in the first instance is to evaluate objectively, with data provided by latest-generation
inertial sensors, the dynamic qualities of the technical-sporting gestures such as serve in tennis. Furthermore, the
possible correlation between the aforementioned data and the evaluation monitoring of the specialized technical
staff (Italian Tennis Federation qualified Coach) was assessed, in essence, a comparison between objective
instrumental data and quality technical analysis. The study is not based on probative statistical numbers, five
athletes, but the interest of the research is focused on establishing the validity, reliability and reproducibility of
the information deriving from the acquisition with inertial instrumentation in the sport of tennis. The work
seemed useful also by virtue of the fact that in the literature not many works have been produced on the subject
at the moment, and in any case not with the latest technologies as in our case (K-Track, K-Sport Universal, Stats
Perform, Montecchio PU, Italy). As mentioned, the research took into consideration the technical fundamental of
the serve, an element that has taken on more and more importance in modern tennis in the achievement of the
point and therefore in the result of the game. The serve is the stroke that marks the beginning of each point and
that can influence the continuance of the same. Moreover, due to the speed of the surfaces of the fields and the
game, the serve became in effect a substantial percentage of the final victory of the match. This is the basic
motivation that led us to analyse this fundamental and its biomechanical composition, however, highlighting
those elements that best qualify the gesture in a performative sense, trying to establish parameters that can be
considered helpful for the technical staff and for the tennis player,in order to improve their performance.
Keywords: IMU, tennis serve, comparative analysis, technical evaluation, professional evaluation, physical dat
New radio observations of anomalous microwave emission in the HII region RCW175
We have observed the HII region RCW175 with the 64m Parkes telescope at
8.4GHz and 13.5GHz in total intensity, and at 21.5GHz in both total intensity
and polarization. High angular resolution, high sensitivity, and polarization
capability enable us to perform a detailed study of the different constituents
of the HII region. For the first time, we resolve three distinct regions at
microwave frequencies, two of which are part of the same annular diffuse
structure. Our observations enable us to confirm the presence of anomalous
microwave emission (AME) from RCW175. Fitting the integrated flux density
across the entire region with the currently available spinning dust models,
using physically motivated assumptions, indicates the presence of at least two
spinning dust components: a warm component with a relatively large hydrogen
number density n_H=26.3/cm^3 and a cold component with a hydrogen number
density of n_H=150/cm^3. The present study is an example highlighting the
potential of using high angular-resolution microwave data to break model
parameter degeneracies. Thanks to our spectral coverage and angular resolution,
we have been able to derive one of the first AME maps, at 13.5GHz, showing
clear evidence that the bulk of the AME arises in particular from one of the
source components, with some additional contribution from the diffuse
structure. A cross-correlation analysis with thermal dust emission has shown a
high degree of correlation with one of the regions within RCW175. In the center
of RCW175, we find an average polarized emission at 21.5GHz of
2.2\pm0.2(rand.)\pm0.3(sys.)% of the total emission, where we have included
both systematic and statistical uncertainties at 68% CL. This polarized
emission could be due to sub-dominant synchrotron emission from the region and
is thus consistent with very faint or non-polarized emission associated with
AME.Comment: Accepted for publication in the Astrophysical Journa
Validation of the new technology sensor fusion K-50 based on data integration detected by GPS 50 Hz and inertial sensors
Advanced technology systems applied to sports are increasingly valid support for operators and technicians in
the sector. Useful to improve the correct planning of training and therefore of the athlete as well as to the correct
management of workloads developed during it and of the season. Studies carried out on the use of new dedicated
technologies have shown how supportive they are for improving the performance and preparedness of the
individual and the athlete in our case, mathematically developing real parameters for the sessions of the sport
practiced (Barbero et a., 2010, Boyd et al., 2011, Brodie et al., 2016, Izzo et al., 2018). The attempt is to further
reduce the error coefficient, of the same, the GPS in this case, the objective of this validation study is the validity
and reliability of the advanced GPS device K-50 (K-Sport Universal, Ita). The test protocol was administered to
50 junior soccer students-players aged 17 ± 3 years by amateur sports clubs in Italy. The athletes were subjected
to different types of stresses considered in the literature, significant in surveys with GPS (Izzo et al., 2018). The
GPS device K-50 in our case is a tool, also equipped with inertial sensors (IMU) such as accelerometer,
magnetometer, gyroscope, and it is the only one on the market that has the features to be able to use the
technologies integrated into a calculation method integrated within the K-50 device, thanks to the use of a Sensor
Fusion which allows more performing and sharper data quality. The results of the research protocol were
compared using different methodologies for the calculation of some investigated parameters or using the GPS
device with the Doppler effect, using the Sensor Fusion, and using the position calculation with different
interpolations such as Lat-Lon 0.2 and Lat-Lon 0.05 (Latitude - longitude). In the end, the decidedly positive test
results verify the validity of the device (GPS K-50). With the use of inertial systems enriched with the Sensor
Fusion the error of the device in measuring the distances traveled is very close to zero with a standard deviation
within the percentage limits
Evaluation of differences at high intensity threshold and its performance value during the most valuable soccer championships in Europe
The sports performance of footballers during games and training has been the subject of research for years.
Nowadays thanks to the new technologies applied to the match analysis, is possible to highlightperformance
using statistical-mathematical criteria. Recent studies support that not only the phase of the match spent at high
speeds are determinants, but even each instant in which the acceleration and deceleration values cross above the
high intensity thresholds.Our research seeks essentially to add, in the literature, a specific study, concerning
quantity and quality of work expressed on these parameters, above the high intensity thresholds, in the various
European elite championships.The search raises 26 players for each match (including substitutes), 260 athletes
per championship, for a total of 1300 players (average age 28.4 years, height 1.79 meters, weight kg 78) and
9100 parameters data.The high intensity parameters evaluated are:Distance covered at high intensity (> 16
Km/h); Distance covered in Acceleration (> 2m/s²); Distance covered in Deceleration (< -2m/s²); Distance
covered a MP> 20 Watt / Kg; Average AMP; D = Total Distance; Drel = distance/minute. Data shows that the
comparison in French league is balanced, that is high intensity activity is equal for winning and losing teams, in
German and Italian championship, winning teams work below the high intensity threshold compared with losers,
in the English and Spanish league winning teams work upper the high intensity threshold respect to losers. This
confirms that the efficiency of sport performance, in case of football the victory of competition or matches, is not
directly dependent only on the ability to carry out high-intensity activities and also supports the lack of specific
training aimed at promoting the development of such skills. A more specific investigation directed at the analysis
of only winning teams and losing teams in all championships showed a no decisive difference in high intensity
parameters. In the chart below, it is highlighted that the high intensity activity is greater in the parameters of
D_AccHI and D_DecHI in the winning teams than the losers (5-6%)
Detailed study of the microwave emission of the supernova remnant 3C 396
We have observed the supernova remnant 3C~396 in the microwave region using
the Parkes 64-m telescope. Observations have been made at 8.4 GHz, 13.5 GHz,
and 18.6 GHz and in polarisation at 21.5 GHz. We have used data from several
other observatories, including previously unpublished observations performed by
the Green Bank Telescope at 31.2 GHz, to investigate the nature of the
microwave emission of 3C 396. Results show a spectral energy distribution
dominated by a single component power law emission with . Data do not favour the presence of anomalous microwave emission coming
from the source. Polarised emission at 21.5 GHz is consistent with
synchrotron-dominated emission. We present microwave maps and correlate them
with infrared (IR) maps in order to characterise the interplay between thermal
dust and microwave emission. IR vs. microwave TT plots reveal poor correlation
between mid-infrared and microwave emission from the core of the source. On the
other hand, a correlation is detected in the tail emission of the outer shell
of 3C 396, which could be ascribed to Galactic contamination.Comment: published in MNRA
Energy resolution and efficiency of phonon-mediated Kinetic Inductance Detectors for light detection
The development of sensitive cryogenic light detectors is of primary interest
for bolometric experiments searching for rare events like dark matter
interactions or neutrino-less double beta decay. Thanks to their good energy
resolution and the natural multiplexed read-out, Kinetic Inductance Detectors
(KIDs) are particularly suitable for this purpose. To efficiently couple
KIDs-based light detectors to the large crystals used by the most advanced
bolometric detectors, active surfaces of several cm are needed. For this
reason, we are developing phonon-mediated detectors. In this paper we present
the results obtained with a prototype consisting of four 40 nm thick aluminum
resonators patterned on a 22 cm silicon chip, and calibrated with
optical pulses and X-rays. The detector features a noise resolution
eV and an (182) efficiency.Comment: 5 pages, 5 figure
Femtosecond Laser-Induced Emission of Coherent Terahertz Pulses from Ruthenium Thin Films
We demonstrate emission of electromagnetic pulses with frequencies in the terahertz (THz) range from ruthenium thin films through a second-order nonlinear optical process. Ruthenium deposited on different substrates showed different THz emission properties. We provide evidence that for Ru on glass above a certain power threshold, laser-induced oxidation occurs, resulting in an increased slope of the linear dependence of the THz electric field amplitude on pump power. The THz electric field is mainly polarized parallel to the sample surface, pointing in the same direction everywhere. In contrast to Ru on glass, the electric field amplitude of the THz pulses emitted by Ru on sapphire and on CaF2 shows a simple single linear dependence on pump power, and it is polarized orthogonal to the sample surface. In this case, thermal oxidation in an oven enhances the emission and introduces an additional polarization component along the sample surface. This component also points in the same direction everywhere on the surface, similar to the as-deposited Ru on glass. Although the precise THz generation mechanism remains an open question, our results show a strong correlation between the emission strength and the degree of oxidation. Furthermore, the results highlight the importance of the interfaces, i.e., both the choice of the substrate and the chemical composition of the top surface in THz emission experiments. Knowledge of the state of the sample surface is therefore crucial for the interpretation of THz emission experiments from (nonmagnetic) metal surfaces.</p
Analysis of the human Y-chromosome haplogroup Q characterizes ancient population movements in Eurasia and the Americas
Background: Recent genome studies of modern and ancient samples have proposed that Native Americans derive from a subset of the Eurasian gene pool carried to America by an ancestral Beringian population, from which two well-differentiated components originated and subsequently mixed in different proportion during their spread in the Americas. To assess the timing, places of origin and extent of admixture between these components, we performed an analysis of the Y-chromosome haplogroup Q, which is the only Pan-American haplogroup and accounts for virtually all Native American Y chromosomes in Mesoamerica and South America. Results: Our analyses of 1.5 Mb of 152 Y chromosomes, 34 re-sequenced in this work, support a "coastal and inland routes scenario" for the first entrance of modern humans in North America. We show a major phase of male population growth in the Americas after 15 thousand years ago (kya), followed by a period of constant population size from 8 to 3 kya, after which a secondary sign of growth was registered. The estimated dates of the first expansion in Mesoamerica and the Isthmo-Colombian Area, mainly revealed by haplogroup Q-Z780, suggest an entrance in South America prior to 15 kya. During the global constant population size phase, local South American hints of growth were registered by different Q-M848 sub-clades. These expansion events, which started during the Holocene with the improvement of climatic conditions, can be ascribed to multiple cultural changes rather than a steady population growth and a single cohesive culture diffusion as it occurred in Europe. Conclusions: We established and dated a detailed haplogroup Q phylogeny that provides new insights into the geographic distribution of its Eurasian and American branches in modern and ancient samples
Hydrolat of Helichrysum italicum promotes tissue regeneration during wound healing
Wound healing is a dynamic process involving different cell types with distinct roles according to the stages of healing. Fibroblasts and stem cells actively participate in tissue regeneration. A proper stimulation could contribute to enhance wound healing processes. Helichrysum italicum (H. italicum) is a medical plant well described for its pharmacological, antimicrobial, and anti-inflammatory activities. Aim of the present work was to examine the effect of the hydrolate derivate from H. italicum on stem cells isolated from skin and fibroblasts in vitro in presence or absence of tissue damage. The viability and proliferation of all cell types cultured in different conditions were analyzed by MTT and BrdU assays. Cell proliferation after wound was analyzed with scratch test. Also, the expression of the main genes involved in tissue repair was evaluated by RT-qPCR analysis. Here we describe the capability of hydrolate of H. italicum to promote tissue regeneration after scratch test both in stem cells and in fibroblasts. Moreover, the gene expression analysis revealed that, hydrolate of H. italicum is also able to enhance stemness related. In conclusion our results are encouraging, highlighting novel regenerative properties of hydrolate of H. italicum and paving the way for future application of this wasting product in accelerating wound healing
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