321 research outputs found
Silicone resins filled with alumina nanoparticles for impregnation of electrical motors title
In the present paper, a new impregnation system for rotor and stator windings of medium and
high power traction motors are obtained using silicone thermosetting resins and alumina
nanoparticles. Silicone nanocomposites are prepared by combined dispersion techniques,
namely mechanical mixing and sonication. Results about thermal, mechanical and electrical
properties of silicone-alumina nanocomposites are shown and compared with those of
unfilled matrix, used as a reference. The influence of different fillers content (1-7% in weight)
on nanocomposites properties is fully discusse
Intense terahertz pulses from SPARC-LAB coherent radiation source
The linac-based Terahertz source at the SPARC_LAB test facility is able to gene
rate highly intense Terahertz broadband
pulses
via
coherent transition radiation (CTR) from high brightness electron beams. The THz pulse duration is typically
down to 100 fs RMS and can be tuned through the electron bunch duration and shaping. The measured stored energy in a
single THz pulse has reached 40
μ
J, which corresponds to a peak
electric field of 1.6 MV/cm at the THz focus. Here we
present the main features, in particular spatial and sp
ectral distributions and energy
characterizations of the
SPARC_LAB THz source, which is very competitive for investigations in Condensed Matter, as well as a valid tool for
electron beam longitudinal diagnostics
Assessement of Malaria Transmission in an Area with Very Low Mosquito Density
The increase in world travel in recent years, especially to and from areas where vector-borne diseases are endemic, has resulted in a substantial rise in imported cases of those diseases. In particular, malaria is a cause of concern. In those countries at the edge of its distribution, it can be difficult to distinguish between autochthonous and imported cases. However, distinguishing between the two is important because of the different allocation of resources to combat the disease that each requires.
In general, observation of the various stages of parasite
development in wild-caught female mosquitoes is considered evidence of autochthonous transmission. Observation of oocysts in the mosquito mid-gut testifies that mosquitoes are susceptible to infection but conclusions
cannot be reached about their ability to complete the transmission cycle. Perhaps the best indication of autochthonous transmission is microscopic observation of sporozoites in mosquito salivary glands, since this detects
parasites ready to be inoculated (BELER et al., 1990). Detection of circumsporozoite protein (CSP)(BURKOT, WILLIAMS & SCHNEIDER, 1984) in dry mosquito thoraxes, by Enzyme Linked Immunosorbent Assay (ELISA) is also widely used to determine transmission, especially when large numbers of mosquitoes need to be processed. Such assays provide information about the parasite species infecting the mosquito (BURKOT & WIRTZ, 1986; WIRTZ et al., 1987; BELER et al., 1990)
On the necessity of a customized knee spacer in peri-prosthetic joint infection treatment: 3d numerical simulation results
Peri-prosthetic joint infections (PJIs) dramatically affect human health, as they are associated with high morbidity and mortality rates. Two-stage revision arthroplasty is currently the gold standard treatment for PJI and consists of infected implant removal, an accurate debridement, and placement of antimicrobial impregnated poly-methyl-metha-acrylate (PMMA) spacer. The use of antibiotic-loaded PMMA (ALPMMA) spacers have showed a success rate that ranges from 85% to 100%. ALPMMA spacers, currently available on the market, demonstrate a series of disadvantages, closely linked to a low propensity to customize, seen as the ability to adapt to the patients’ anatomical characteristics, with consequential increase of surgical complexity, surgery duration, and postoperative complications. Conventionally, ALPMMA spacers are available only in three or four standard sizes, with the impossibility of guaranteeing the perfect matching of ALPMMA spacers with residual bone (no further bone loss) and gap filling. In this paper, a 3D model of an ALPMMA spacer is introduced to evaluate the cause-effect link between the geometric characteristics and the correlated clinical improvements. The result is a multivariable-oriented design able to effectively manage the size, alignment, stability, and the patients’ anatomical matching. The preliminary numerical results, obtained by using an “ad hoc” 3D virtual planning simulator, clearly point out that to restore the joint line, the mechanical and rotational alignment and the surgeon’s control on the thicknesses (distal and posterior thicknesses) of the ALPMMA spacer is mandatory. The numerical simulations campaign involved nineteen patients grouped in three different scenarios (Case N◦ 1, Case N◦ 2 and Case N◦ 3) whose 3D bone models were obtained through an appropriate data management strategy. Each scenario is characterized by a different incidence rate. In particular, the observed rates of occurrence are, respectively, equal to 17% (Case N◦ 1), 74% (Case N◦ 2), and 10% (Case N◦ 3)
The transverse and longitudinal beam characteristics of the phin photo-injector at Cern
International audienceThe laser driven RF photo-injectors are recent candidates for high-brightness, low-emittance electron sources. One of the main beam dynamics issues for a high brightness electron source is the optimization of beam envelope be- havior in the presence of the space charge force in order to get low emittance. Within the framework of the second Joint Research Activity PHIN of the European CARE pro- gram, a new photo-injector for CTF3 has been designed and installed by collaboration between LAL, CCLRC and CERN. Beam based measurements have been made dur- ing the commissioning runs of the PHIN 2008 and 2009 including measurements of the emittance, using multi-slit technique. The demonstration of the high charge and the stability along the long pulse train are between the goals of this photo-injector study as also being important issues for CTF3 and the CLIC drive beam. In this work the photo-injector will be described and the first beam mea- surement results will be presented and compared with the PARMELA simulations
Single-shot non-intercepting profile monitor of plasma-accelerated electron beams with nanometric resolution
An innovative, single-shot, non-intercepting monitor of the transverse profile of plasma-accelerated electron beams is presented, based on the simultaneous measurement of the electron energy and the betatron radiation spectra. The spatial resolution is shown to be down to few tens of nanometers, important for high-precision applications requiring fine shaping of beams and detailed characterizations of the electron transverse phase space at the exit of plasma accelerating structures
The last bastion? X-chromosome genotyping of Anopheles gambiae species-pair males from a hybrid zone reveals complex recombination within the major candidate ‘genomic island of speciation’
Speciation with gene flow may be aided by reduced recombination helping to build linkage between genes involved in the early stages of reproductive isolation. Reduced recombination on chromosome-X has been implicated in speciation within the Anopheles gambiae complex, species of which represent the major Afrotropical malaria vectors. The most recently diverged, morphologically-indistinguishable, species-pair, An. gambiae and An. coluzzii, ubiquitously display a ‘genomic island of divergence’ spanning over 4Mb from chromosome-X centromere, which represents a particularly promising candidate region for reproductive isolation genes, in addition to containing the diagnostic markers used to distinguish the species. Very low recombination makes the island intractable for experimental recombination studies, but an extreme hybrid zone in Guinea Bissau offers the opportunity for natural investigation of X-island recombination. SNP-analysis of chromosome-X hemizygous males revealed: (i) strong divergence in the X-island despite a lack of autosomal divergence; (ii) individuals with multiple-recombinant genotypes, including likely double crossovers and localized gene conversion; (iii) recombination-driven discontinuity both within and between the molecular species markers, suggesting that the utility of the diagnostics is undermined under high hybridization. The largely-, but incompletely-protected nature of the X-centromeric genomic island is consistent with a primary candidate area for accumulation of adaptive variants driving speciation with gene flow, whilst permitting some selective shuffling and removal of genetic variation
Beam manipulation for resonant plasma wakefield acceleration
Plasma-based acceleration has already proved the ability to reach ultra-high accelerating gradients. However
the step towards the realization of a plasma-based accelerator still requires some e
ff ort to guarantee high brightness beams, stability and reliability. A significant improvement in the efficiency of PWFA has been
demonstrated so far accelerating a witness bunch in the wake of a higher charge driver bunch. The transformer
ratio, therefore the energy transfer from the driver to the witness beam, can be increased by resonantly exciting
the plasma with a properly pre-shaped drive electron beam. Theoretical and experimental studies of beam
manipulation for resonant PWFA will be presented her
Interactions of Heavy Hadrons using Regge Phenomenology and the Quark Gluon String Model
The search for stable heavy exotic hadrons is a promising way to observe new
physics processes at collider experiments. The discovery potential for such
particles can be enhanced or suppressed by their interactions with detector
material. This paper describes a model for the interactions in matter of stable
hadrons containing an exotic quark of charges or
using Regge phenomenology and the Quark Gluon String Model. The influence of
such interactions on searches at the LHC is also discussed
Summary of the SUSY Working Group of the 1999 Les Houches Workshop
The results obtained by the Working Group on Supersymmetry at the 1999 Les
Houches Workshop on Collider Physics are summarized. Separate chapters treat
"general" supersymmetry, R-parity violation, gauge mediated supersymmetry
breaking, and anomaly mediated supersymmetry breaking.Comment: LaTeX, 110 pages with numerous .ps and .eps files. proc.tex is main
tex fil
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