4,779 research outputs found
Experimental effects on dynamics and thermodynamics in nuclear reactions on the symmetry energy as seen by the CHIMERA 4 detector
Heavy ion collisions have been widely used in the last decade to constraint
the parameterizations of the symmetry energy term of nuclear equation of state
(EOS) for asymmetric nuclear matter as a function of baryonic density. In the
Fermi energy domain one is faced with variations of the density within a narrow
range of values around the saturation density =0.16 fm down
towards sub-saturation densities. The experimental observables which are
sensitive to the symmetry energy are constructed starting from the detected
light particles, clusters and heavy fragments that, in heavy ion collisions,
are generally produced by different emission mechanisms at different stages and
time scales of the reaction. In this review the effects of dynamics and
thermodynamics on the symmetry energy in nuclear reactions are discussed and
characterized using an overview of the data taken so far with the CHIMERA
multi-detector array.Comment: 21 pages, 25 figures. Review to appear in EPJA special volume on
nuclear symmetry energ
Total thyroidectomy associated to chemotherapy in primary squamous cell carcinoma of the thyroid
Primary squamous cell carcinoma of the thyroid (PSCCT) is a rare malignant disease with rapid fatal prognosis. The onset is generally characterized by sudden bilateral latero-cervical lymphadenopathy. The Authors report patient of 58-year-old who referred for evaluation of rapidly aggravating bilateral latero-cervical lymphadenopathy. The US highlighted the presence of a hypoechoic nodular lesion characterized by peri and intra-nodular vascularization. Multilayer CT showed diffused involvement of mediastinal and bilateral latero-cervical lymph nodes, with no evidence of primary pulmonary neoplasia or elsewhere. The patient underwent total thyroidectomy. The peri-isthmic tissue was removed due to the presence of a small roundish formation, that was due to lymph node metastasis at histological examination. Histological diagnosis: PSCCT. The immunohistochemical panel of the thyroid lesion was indispensable for the differential diagnosis between PSCCT, medullary carcinoma, anaplastic carcinoma, and thyroid metastasis of neoplasia with unknown primitiveness. The patient underwent chemotherapeutic treatment with Carboplatin and Paclitaxel with modest improvement of dysphagia symptoms and reduction of 10-15% of the target lesions. The clinical course was characterized by loco-regional progression of the disease with exitus in 10 months after diagnosis. Survival and quality of life after surgical therapy and chemotherapy were like that of patients undergoing only chemotherapy. Due to the extreme rarity of the neoplasia, 60 cases described in Literature, no exclusive guidelines are reported for PSCCT. More extensive case studies are needed to evaluate the effects of total thyroidectomy with intent R0/R1 on improving survival and quality of life of patients with PSCCT
Microscopic construction of the chiral Luttinger liquid theory of the quantum Hall edge
We give a microscopic derivation of the chiral Luttinger liquid theory for
the Laughlin states. Starting from the wave function describing an arbitrary
incompressibly deformed Laughlin state (IDLS) we quantize these deformations.
In this way we obtain the low-energy projections of local microscopic operators
and derive the quantum field theory of edge excitations directly from quantum
mechanics of electrons. This shows that to describe experimental and numeric
deviations from chiral Luttinger liquid theory one needs to go beyond
Laughlin's approximation. We show that in the large N limit the IDLS is
described by the dispersionless Toda hierarchy.Comment: 5 pages, revtex, several clarifying comments adde
Lean practices implementation, their criticalities and their relationships with operational responsiveness and firm performance
In the last few years, at European Union level, companies are facing many obstacles due to macroeconomic instability. In order to stay competitive and survive in the present world turmoil, companies must seek to new ways of reducing costs, increase the quality of the products and meet the ongoing changes in the market. Driven by the success performed by Toyota and several other organizations worldwide, a growing number of firms have been adopting Lean manufacturing practices to fulfill market needs, reduce costs, and gain competitive advantages over competitors. But, although many firms report large benefits from Lean implementation, Lean is not a panacea. Through an overview of Lean strategy implementation in Italian manufacturing industries, and a classification in "low"/"medium" and "high lean performers" we are able to see whether lean thinking could be a way for improving operational performance. Moreover, combining field interviews with the literature review, theoretical connections have been developed among Lean manufacturing techniques, operational responsiveness and firm growth performances. A conceptual model has been proposed and represented. The aim is investigating the network of influences among lean best practices (supplier practices, workforce practices, production efficiency practices and quality practices), operational responsiveness (Product mix variety, Product innovation and Time effectiveness) and firm growth performances
Study of the Fusion-Fission Process in the Reaction
Fusion-fission and fully energy-damped binary processes of the
Cl+Mg reaction were investigated using particle-particle
coincidence techniques at a Cl bombarding energy of E
8 MeV/nucleon. Inclusive data were also taken in order to determine the partial
wave distribution of the fusion process. The fragment-fragment correlation data
show that the majority of events arises from a binary-decay process with a
relatively large multiplicity of secondary light-charged particles emitted by
the two primary excited fragments in the exit channel. No evidence is observed
for ternary-breakup processes, as expected from the systematics recently
established for incident energies below 15 MeV/nucleon and for a large number
of reactions. The binary-process results are compared with predictions of
statistical-model calculations. The calculations were performed using the
Extended Hauser-Feshbach method, based on the available phase space at the
scission point of the compound nucleus. This new method uses
temperature-dependent level densities and its predictions are in good agreement
with the presented experimental data, thus consistent with the fusion-fission
origin of the binary fully-damped yields.Comment: 30 pages standard REVTeX file, 10 eps Figures; to be published at the
European Physical Journal A - Hadrons and Nucle
Alternative linear structures for classical and quantum systems
The possibility of deforming the (associative or Lie) product to obtain
alternative descriptions for a given classical or quantum system has been
considered in many papers. Here we discuss the possibility of obtaining some
novel alternative descriptions by changing the linear structure instead. In
particular we show how it is possible to construct alternative linear
structures on the tangent bundle TQ of some classical configuration space Q
that can be considered as "adapted" to the given dynamical system. This fact
opens the possibility to use the Weyl scheme to quantize the system in
different non equivalent ways, "evading", so to speak, the von Neumann
uniqueness theorem.Comment: 32 pages, two figures, to be published in IJMP
Nuclear Matter and Nuclear Dynamics
Highlights on the recent research activity, carried out by the Italian
Community involved in the "Nuclear Matter and Nuclear Dynamics" field, will be
presented.Comment: Proceedings of the 12th Conference on Problems in Theoretical Nuclear
Physics, to appear in Journal of Physics, Conference Serie
Comparison of bioelectrical impedance analysis and dual-energy X-ray absorptiometry for the assessment of appendicular body composition in anorexic women
Objective: To establish the accuracy of bioelectrical impedance analysis (BIA) for the assessment of appendicular body
composition in anorexic women.
Design: Cross-sectional study.
Setting: Outpatient University Clinic.
Subjects: A total of 39 anorexic and 25 control women with a mean (s.d.) age of 21 (3) y.
Methods: Total, arm and leg fat-free mass (FFM) were measured by dual-energy X-ray absorptiometry and predicted from total
and segmental BIA at 50 kHz. The predictor variable was the resistance index (Rl), that is, the ratio of height 2 to body resistance
for the whole body and the ratio of length2/limb resistance for the arm and leg.
Results: Predictive equations developed on controls overestimated total, arm and leg FFM in anorexics (Po0.0001). Populationspecific
equations gave a satisfactory estimate of total and appendicular FFM in anorexics (P\ubcNS) but had higher percent root
mean square errors (RMSEs%) as compared to those developed on controls (8% vs 5% for whole body, 12% vs 10% for arm and
10% vs 8% for leg). The accuracy of the estimate of total and leg FFM in anorexics was improved by adding body weight (Wt) as
a predictor with Rl (RMSE%\ubc5% vs 8% and 7% vs 10%, respectively). However, the same accuracy was obtained using Wt
alone, suggesting that in anorexics, BIA at 50 kHz is not superior to Wt for assessing total and leg FFM.
Conclusion: BIA shows some potential for the assessment of appendicular body composition in anorexic women. However, Wt
is preferable to BIA at 50 kHz on practical grounds. Further studies should consider whether frequencies 450 kHz give better
estimates of appendicular composition in anorexics as compared to Wt
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