773 research outputs found
Synchrotron oscillation damping due to beam-beam collisions
In DA{\Phi}NE, the Frascati e+/e- collider, the crab waist collision scheme
has been successfully implemented in 2008 and 2009. During the collision
operations for Siddharta experiment, an unusual synchrotron damping effect has
been observed. Indeed, with the longitudinal feedback switched off, the
positron beam becomes unstable with beam currents in the order of 200-300 mA.
The longitudinal instability is damped by bringing the positron beam in
collision with a high current electron beam (~2A). Besides, we have observed a
shift of \approx 600Hz in the residual synchrotron sidebands. Precise
measurements have been performed by using both a commercial spectrum analyzer
and the diagnostics capabilities of the DA{\Phi}NE longitudinal bunch-by-bunch
feedback. This damping effect has been observed in DA{\Phi}NE for the first
time during collisions with the crab waist scheme. Our explanation is that beam
collisions with a large crossing angle produce a longitudinal tune shift and a
longitudinal tune spread, providing Landau damping of synchrotron oscillations.Comment: 3 pages, 5 figures, talk presented to IPAC'10 - Kyoto - May 24-28
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Effects of extruded linseed dietary supplementation on milk yield, milk quality and lipid metabolism of dairy cows
Twenty Italian Friesian dairy cows were used in an experimental trial to study the effects of extruded linseed dietary supplementation on milk production, milk quality and fatty acid (FA) percentages of milk fat and total plasma lipids and plasma phospholipids. Control cows were fed a corn silage based total mixed ration (TMR) while treated animals also received 700g/head/d of extruded linseed supplementation. Feed intake was similar between groups. Milk yields was tendentially greater for cows fed extruded linseed. Milk urea content (P<0.05) were reduced by treatment. Results showed a significant increase n-3 FA concentration (particularly alpha linolenic acid) and a significant reduction of n-6/n-3 FA ratio in milk fat, total plasma lipids and plasma phospholipids (P<0.001); moreover a reduction trend (P<0.1) of arachidonic acid concentrations was observed in milk fat, total plasma lipids and plasma phospholipids. At last, treatment enhanced milk fat conjugated linoleic acid (CLA) percentage (P<0.05)
Effects of the rearing season on carcass and meat quality of suckling Apennine light lambs
The aim of this study was to evaluate the effects of the rearing season (autumn vs winter) on the carcass and
meat quality of light lambs, obtained according to the traditional farming system usual in central Italy. Eighty
carcasses from 60 d±3 old unweaned Apennine single birth male lambs, permanently reared indoor, half in
autumn (receiving milk from ewes permanently pastured) and half in winter (which dams did never
acceded to pasture), were weighed, classified according to the EU classification system for light lambs, and
their Longissimus lumborum meat was analysed for pH, colour, drip and cooking losses, proximate
composition and fatty acids profile of intramuscular fat. Most of the carcasses fully responded to the 1st
quality EU requirements and no effects of the rearing season was evident on carcass characteristics. On the
contrary, L. lumborum of lambs born and reared in autumn, receiving milk from ewes permanently pastured,
evidenced a lower Lightness L* (P=0.02), a higher Chroma C* (P=0.01), with a higher fat content (P=0.04)
than lambs reared in winter, which dams were permanently stall-fed. Moreover the intramuscular fat of the
former was characterized by a greater PUFA concentration (P=0.01), a more favourable n-6/n-3 ratio
(Pb 0.001), and a higher CLA content (Pb0.001) than the latter, as a result of the difference related to the
sheep traditional feeding system
Crescere a Pinerolo: stili di vita, benessere e futuro dei ragazzi
Come vivono i ragazzi? Cosa fanno, cosa pensano, come si relazionano in famiglia e con gli amici? Come aiutarli a crescere bene? Lo studio «Crescere a Pinerolo» si rivolge a 800 ragazzi, dai 12 fino ai 20 anni, che ci raccontano la loro vita, i loro problemi e difficoltà, ma anche le loro potenzialità. I risultati offrono un quadro positivo degli adolescenti: il dialogo con i genitori favorisce le relazioni in famiglia e complessivamente si sentono supportati e protetti, la scuola piace abbastanza e viene compresa l’importanza dell’istruzione. Tra gli aspetti critici che emergono vi sono: la solitudine nell’era digitale, il bullismo verbale e relazionale, l’incertezza del futuro.Fil: Vignola Barbero, G.. Fondazione Emanuela Zancan; ItaliaFil: Canali, Cinzia. Fondazione Emanuela Zancan; ItaliaFil: Eynard, Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones y Estudios sobre Cultura y Sociedad. Universidad Nacional de Córdoba. Centro de Investigaciones y Estudios sobre Cultura y Sociedad; ArgentinaFil: Vecchiato, Tiziano. Fondazione Emanuela Zancan; Itali
Neutron diffraction in gemology: Single-crystal diffraction study of brazilianite, NaAl3(PO4)(2)(OH)(4)
The chemical composition and the crystal structure of a gem-quality brazilianite from the Telírio pegmatite, near Linópolis, Minas Gerais, Brazil, [NaAl3(PO4)2(OH)4, a = 11.2448(5) Å, b = 10.1539(6) Å, c = 7.1031(3) Å, β = 97.351(4)°, V = 804.36(7) Å3, space group P21/n, Z = 4], have been reinvestigated by means of electron microprobe analysis in wavelength-dispersive mode, single-crystal X-ray and neutron diffraction. The chemical analysis shows that brazilianite from Telírio Claim approaches almost ideal composition. The neutron anisotropic structural refinement was performed with final agreement index R1 = 0.0290 for 211 refined parameters and 2844 unique reflections with Fo > 4σ(Fo), the X-ray refinement led to R1 = 0.0325 for 169 refined parameters and 2430 unique reflections with Fo > 4σ(Fo). The building-block units of the brazilianite structure consist of chains of edge-sharing AlO4(OH)2 and AlO3(OH)3 octahedra. Chains are connected, via corner-sharing, by P-tetrahedra to form a three-dimensional framework, with Na atoms located in distorted cavities running along [100]. Five independent H sites were located, here labeled as H(1), H(2a), H(2b), H(3), and H(4). The configuration of the OH groups, along with the complex hydrogen-bonding scheme, are now well defined. The O-H distances corrected for "riding motion" range between ~0.992 and ~1.010 Å, the O···O distances between ~2.67 and ~2.93 Å, and the O-H···O angles between ~151° and ~174°. The H(2a) and H(2b) are only ~1.37 Å apart and mutually exclusive (both with site occupancy factor of 50%). The differences between the crystal structure of brazilianite and wardite [ideally NaAl3(PO4)2(OH)4·2H2O] are discussed. This work fulfills the need for accurate crystal-chemical data for this gem mineral
Commissioning of the DAΦNE beam test facility
Abstract The DAΦNE Beam Test Facility (BTF) is a beam transfer line optimized for the production of electron or positron bunches, in a wide range of multiplicities and down to single-electron mode, in the energy range between 50 and 800 MeV . The typical pulse duration is 10 ns and the maximum repetition rate is 50 Hz . The facility design has been optimized for detector calibration purposes. The BTF has been successfully commissioned in February 2002 and started operation in the same year in November. The schemes of operation, the commissioning results, as well as the first users' experience are reported here
Effects of loading methods on rabbit welfare and meat quality
The effects of different loading methods on the welfare, carcass characteristics and meat quality traits of hybrid commercial rabbits were investigated. 384 male rabbits, 82 days old, were transported from the farm to the slaughterhouse. At the farm, 192 rabbits were loaded onto the truck smoothly (S) and 192 rabbits were loaded roughly (R). The S loading method consisted of carefully placing each rabbit into the transport crates. In the R method, the loading was hurriedly and carelessly executed by the transport operator, throwing each animal into the crates fixed on the truck.
Live weight before and after transport as well as slaughter data were recorded for each rabbit, and a subset of 80 carcasses were evaluated for meat quality. Blood samples from 80 rabbits were analysed for haematological and biochemical parameters. A significant neutrophilia (P < 0.001), lymphocytopaenia (P < 0.001) and an increase in serum aspartate aminotransferase (AST) (P < 0.01), alanine aminotransferase (ALT) (P < 0.001) and creatine kinase (CK) activities (P < 0.001) were recorded in all rabbits after transport, independent of the loading method. A twofold increase in serum corticosterone concentration (6.23 vs. 14.88 ng/mL; P = 0.001) was observed in all rabbits following transport. Results suggest that the stress parameters analysed were more influenced by transport and handling itself rather than by the different loading methods. The results showed that there was no adverse effect of loading method on carcass traits. Furthermore, the stress condition evidenced by haematological and biochemical parameters prior to slaughter did not affect meat quality
Impact of the Wiggler Coherent Synchrotron Radiation Impedance on the Beam Instability
Coherent Synchrotron Radiation (CSR) can play an important role by not only
increasing the energy spread and emittance of a beam, but also leading to a
potential instability. Previous studies of the CSR induced longitudinal
instability were carried out for the CSR impedance due to dipole magnets.
However, many storage rings include long wigglers where a large fraction of the
synchrotron radiation is emitted. This includes high-luminosity factories such
as DAPHNE, PEP-II, KEK-B, and CESR-C as well as the damping rings of future
linear colliders. In this paper, the instability due to the CSR impedance from
a wiggler is studied assuming a large wiggler parameter . The primary
consideration is a low frequency microwave-like instability, which arises near
the pipe cut-off frequency. Detailed results are presented on the growth rate
and threshold for the damping rings of several linear collider designs.
Finally, the optimization of the relative fraction of damping due to the
wiggler systems is discussed for the damping rings.Comment: 10 pages, 7 figure
Precision livestock farming, automats and new technologies: possible applications in extensive dairy sheep farming
Precision livestock farming (PLF) technologies are becoming increasingly common in modern agriculture. They are frequently integrated with other new technologies in order to improve human–livestock interactions, productivity and economical sustainability of modern farms. New systems are constantly being developed for concentrated farming operations as well as for extensive and pasture-based farming systems. The development of technologies for grazing animals is of particular interest for the Mediterranean extensive sheep farming sector. Dairy sheep farming is a typical production system of the area linked to its historical and cultural traditions. The area provides roughly 40% of the world sheep milk, having 27% of the milk-producing ewes. Developed countries of the area (France, Italy, Greece and Spain – FIGS) have highly specialized production systems improved through animal selection, feeding techniques and intensification of production. However, extensive systems are still practiced alongside intensive ones due to their lower input costs and better resilience to market fluctuations. In the current article, we evaluate possible PLF systems and their suitability to be incorporated in extensive dairy sheep farming as practiced in the FIGS countries. Available products include: electronic identification systems (now mandatory in the EU) such as ear tags, ruminal boluses and sub-cutaneous radio-frequency identification; on-animal sensors such as accelerometers, global positioning system) and social activity loggers; and stationary management systems such as walk-over-weights, automatic drafter (AD), virtual fencing and milking parlour-related technologies. The systems were considered according to their suitability for the management and business model common in dairy sheep farming. However, adoption of new technologies does not take place immediately in small and medium scale extensive farmer. As sheep farmers usually belong to more conservative technology consumers, characterized by average age of 60 and a very transparent community, dynamics which does not favour financial risk taking involved with new technologies. Financial barriers linked to production volumes and resource management of extensive farming are also a barrier for innovation. However, future prospective could increase the importance of technology and promote its wider adoption. Trends such as global sheep milk economics, global warming, awareness to animal welfare, antibiotics resistance and European agricultural policies could influence the farming practices and stimulate wider adoption of PLF systems in the near future
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