324 research outputs found
TULOU: THE RAMMED EARTH DWELLINGS OF FUJIAN (CHINA). FUNCTIONAL, TYPOLOGICAL AND CONSTRUCTIVE FEATURES
Abstract. This research is focused on different aspects concerning two types of Tulou: Minnan and Hakka Tulou. Through the analysis of eight case studies, we managed to highlight the relation between typological-functional features and constructive ones aiming to offer a more orderly analysis of distinct models, divided into two substantially different families. Future studies will further analyse the knowledge of these rammed earth buildings by studying the phases of the construction site, conducting architectural surveys on the most important details and investigating the mechanical behaviour of both types. The future goal is the creation of a "Manuale del recupero dei Tulou" (Manual on Tulou restoration) in order to provide a guide for restoration and spread the knowledge about original materials and techniques applied in the construction of these unique rammed earth architectures. The research, which is currently ongoing, has been carried out by the Architecture Department of Roma Tre University in cooperation with Fuzhou University
SN1987A: Revisiting the Data and the Correlation between Neutrino and Gravitational Detectors
We re-examine the data taken by the neutrino detectors during the supernova
SN1987A. It is found that the Kamiokande data, in addition to the well known
burst at 7:35 hours UT, show another one at 7:54 hours, with seven pulses in
6.2 seconds. This second burst supports the idea that the duration of the
collapse was much longer than a few seconds, as already suggested by the LSD
detection at 2:56 hours the same day, i.e. four and a half hours earlier. The
correlations between the gravitational wave detectors (Rome and Maryland) and
the neutrino detectors are also revisited. It is shown that the g.w. detectors
exhibit significant correlations with both the LSD and the Kamiokande detectors
over periods of one-two hours that are centered, in both cases, at the LSD
time.Comment: Presented at the VULCANO WOKSHOP 2008, Frontier Objects in
Astrophysics and Particle Physics, May 26-3
The fast matched filter for gravitational-wave data analysis: Characteristics and applications
We report on the application of a matched filter to the data of two-mode resonant gravitational-wave antennas for the detection of burst signals, with reference to data obtained by direct acquisition, i.e. without going through
lock-in amplifiers, sampled at relatively high speed. After a review of the basic model of resonant detectors, that includes a discussion of the signal and of the noise, we
present a detailed mathematical derivation of the optimum filter matched to an input burst. We then analyze and discuss the performance of the matched filter as regards
both the improvement of the signal-to-noise ratio and the observation bandwidth, also considering the adaptive realization of the filter, based on the actual spectrum of
the noise as estimated from the data. The discussion that follows is centered on various aspects concerning the practical application of the matched filter as well as
the loss of performance due both to uncertainties on the parameters used for building the filter and to various discretization effects, both in the time and frequency domains. Finally, we consider some experimental results obtained by applying the matched filter to the data of the Explorer detector, also providing a comparison with what we obtained by applying an optimum filter to data processed
by lock-in amplifiers, sampled at lower speed
Intermodal vs. conventional logistic of refrigerated products: a case study from Southern to Northern Europe
Most of perishable goods, such as fruit and vegetables, are transported in Europe by truck and clogging up the main road networks. The increasing demand for freight transport and the environmental concerns all indicate the necessity to embrace new means of transport such as the intermodal one. The intermodal transport uses swap bodies and reefer containers that allow for the use of interchangeable truck, train, and ship to reduce direct and external costs. Nowadays, the utilization of exclusive truck transport is due to its considerable flexibility and often to the disregard of the motor vehicle regulations during transport. This research aims to analyze some essential readjustments that must be made in order to increase efficiency in the logistic of refrigerated fruit and vegetables. To do so, some hypotheses were analyzed and formulated in which the strategic use of the truck was recognized and inserted as part of an intermodal transport system. The transport options of a combined use of ships and trains in association with trucks were evaluated with respect to the current prevalent solution of exclusive use of trucks. Such options were evaluated by comparing them under different itineraries hypotheses (from south Italy, Sicily to Germany, Munich) on the base of costs and transit-times parameters. This was done mainly throughout interviewing sector-relevant transport operators. The results of the comparison between the intermodal and conventional transport was shown to be economically more convenient with respect to both legal and illegal transport by exclusive truck transport, presenting lower per unit costs (swap body or semi-trailer, containing the same amount of goods). Moreover, the intermodal solution scores equal or higher transit times in the comparison with the âtransit by regulation complianceâ and much higher transit times if compared with the âillegalâ option. Therefore, the regulation compliance aspect would partially promote the use of intermodal options in a future fair competition. In addition, besides reducing the direct costs, it produces several other positive effects in terms of external costs to the society such as to reduce road crashes, noises, atmospheric emissions and greenhouse effect. A more efficient system should plan an integrated system of arrival and departure organizing together the schedules of ships and trains dedicated to perishable goods and increasing the transported amounts. Furthermore, another idea is to stipulate commercial agreements with train operators, applying a reduction on the base price, by ensuring the delivery of a block train for an arranged period. Â Keywords: Intermodal, freight logisticcentre, truck haulage, rail hub; terminal
Search for Periodic Gravitational Wave Sources with the Explorer Detector
We have developped a procedure for the search of periodic signals in the data
of gravitational wave detectors. We report here the analysis of one year of
data from the resonant detector Explorer, searching for pulsars located in the
Galactic Center (GC). No signals with amplitude greater than , in the range 921.32-921.38 Hz, were observed using data
collected over a time period of 95.7 days, for a source located at
hours and degrees. Our
procedure can be extended for any assumed position in the sky and for a more
general all-sky search, even with a frequency correction at the source due to
the spin-down and Doppler effects.Comment: One zipped file (Latex+eps figures). 33 pages, 14 figures. This and
related material also at http://grwav3.roma1.infn.it
An Advanced Colour Calibration Method for Fish Freshness Assessment: a Comparison Between Standard and Passive Refrigeration Modalities
Freshness represents a pivotal aspect in fish product for both security and quality. Its evaluation still represents the key factor driving the consumer' choices. Fish appearance is affected by many different factors that demand the contribution of different disciplines to be understood: from the physical and optical properties to the slaughtering and post-slaughtering conditions. An innovative preservation system is represented by the Passive Refrigeration PRS (TM) developed for the preservation and transport of perishable food products. Scientific methods for product freshness evaluation may be conveniently divided into two categories: sensorial and instrumental. In this study, an instrumental method of colour calibration and discrimination is proposed at pilot scale for automatic evaluation of gilthead seabream (Sparus aurata) freshness. We propose a non-destructive method based on the colorimetric imaging of the whole external body of seabreams to evaluate through multivariate partial least squares which approach the differences in the freshness preservation under four refrigeration modalities. The matrix of the independent variables is represented by RGB values for each pixel belonging to an extracted region of interest (129,633 values). The dependent variable is composed by two dummy variable corresponding to fresh (T-0) or non-fresh (T-2) individuals. T-1 individuals were used as external test. The results quantified significant colorimetric differences between fresh and non-fresh fish. All fish used to create the model (T-0 and T-2) were correctly classified as fresh or non-fresh, while external test individuals (T-1) were all classified as fresh. The proposed imaging method merges different image analysis techniques: (a) colorimetric calibration, (b) morphometric superimposition and (c) partial least square discriminant analysis modelling. This innovative and non-destructive approach allows the automatic assessment of fish freshness
Increasing the bandwidth of resonant gravitational antennas: The case of Explorer
Resonant gravitational wave detectors with an observation bandwidth of tens
of hertz are a reality: the antenna Explorer, operated at CERN by the ROG
collaboration, has been upgraded with a new read-out. In this new
configuration, it exhibits an unprecedented useful bandwidth: in over 55 Hz
about its frequency of operation of 919 Hz the spectral sensitivity is better
than 10^{-20} /sqrt(Hz) . We describe the detector and its sensitivity and
discuss the foreseable upgrades to even larger bandwidths.Comment: 4 pages- 4 figures Acceted for publication on Physical Review Letter
Quark nuggets search using 2350 Kg gravitational waves aluminum bar detectors
The gravitational wave resonant detectors can be used as detectors of quark
nuggets, like nuclearites (nuclear matter with a strange quark). This search
has been carried out using data from two 2350 Kg, 2 K cooled, aluminum bar
detectors: NAUTILUS, located in Frascati (Italy), and EXPLORER, that was
located in CERN Geneva (CH). Both antennas are equipped with cosmic ray shower
detectors: signals in the bar due to showers are continuously detected and used
to characterize the antenna performances. The bar excitation mechanism is based
on the so called thermo-acoustic effect, studied on dedicated experiments that
use particle beams. This mechanism predicts that vibrations of bars are induced
by the heat deposited in the bar from the particle. The geometrical acceptance
of the bar detectors is 19.5 sr, that is smaller than that of other
detectors used for similar searches. However, the detection mechanism is
completely different and is more straightforward than in other detectors. We
will show the results of ten years of data from NAUTILUS (2003-2012) and 7
years from EXPLORER (2003-2009). The experimental limits we obtain are of
interest because, for nuclearites of mass less than grams, we find a
flux smaller than that one predicted considering nuclearites as dark matter
candidates.Comment: presented to the 33rd International Cosmic Ray Conference Rio de
Janeiro 201
Resonant gravitational wave antennas for stochastic background measurements
The sensitivity of a resonant gravitational wave (GW) antenna is calculated in terms of spectral density and frequency bandwidth. For a quantum-limited detector the bandwidth might reach values greater than 100 Hz, with a sensitivity to bursts of . The spectral amplitude sensitivity for the Nautilus detector has been measured to be and its target value is . Using two near-Nautilus detectors the GW stochastic background can be measured with a sensitivity, with respect to the critical density, of a few for an integration time of one year, as shown by simulations
All-sky upper limit for gravitational radiation from spinning neutron stars
We present results of the all-sky search for gravitational-wave signals from
spinning neutron stars in the data of the EXPLORER resonant bar detector. Our
data analysis technique was based on the maximum likelihood detection method.
We briefly describe the theoretical methods that we used in our search. The
main result of our analysis is an upper limit of for
the dimensionless amplitude of the continuous gravitational-wave signals coming
from any direction in the sky and in the narrow frequency band from 921.00 Hz
to 921.76 Hz.Comment: 12 pages, 4 figures, submitted to Proceedings of 7th Gravitational
Wave Data Analysis Workshop, December 17-19, 2002, Kyoto, Japa
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