266 research outputs found
Leading particles and diffractive spectra in the Interacting Gluon Model
We discuss the leading particle spectra and diffractive mass spectra from the
novel point of view, namely by treating them as particular examples of the
general energy flow phenomena taking place in the multiparticle production
processes. We argue that they show a high degree of universality what allows
for their simple description in terms of the Interacting Gluon Model developed
by us some time ago.Comment: Presented at Diffraction2002, Alushta, Crimea (Ukraina), August 31 -
September 5, 2002. To be published by Kluwer Academic Publishers (2003)
(necessary style files attached). Rewritten according to the Kluwer
specification
Teachers’ ideas about children’s participation within Portuguese early childhood education settings
This study investigated teachers’ ideas about children's right to participate in ECE. Participants were 59 teachers, aged between 26 and 60 years old (M = 43.07 years, SD = 8.58), all female, from 59 ECE classrooms from 24 randomly selected ECE centres located in the metropolitan area of Lisbon. Teacher's ideas were collected using a qualitative interview specifically designed for the purpose. Based on content analysis, multiple correspondence analysis, and cluster analysis, we identified profiles of teachers’ ideas and clusters of teachers. Results suggest four teacher profiles: Teachers motivation, Teachers’ conditioned responsibility, Children's benefits, and Context dependent. Profiles were significantly associated with years of professional experience and type of institution. Teachers’ age was significantly different across profiles. Findings provide insights to fuller understand teachers’ positioning about this right.info:eu-repo/semantics/acceptedVersio
Leading nucleon and inelasticity in hadron-nucleus interactions
We present in this paper a calculation of the average proton-nucleus ine-
lasticity. Using an Iterative Leading Particle Model and the Glauber model, we
relate the leading particle distribution in nucleon-nucleus interactions with
the respective one in nucleon-proton collisions. To describe the leading
particle distribution in nucleon-proton collisions, we use the Regge-Mueller
formalism. To appear in Journal of Physics G.Comment: 11 pages, 2 figure
Reductive intramolecular cyclization of D-glucose-based unsaturated substrates by indirect electrochemical approach in “Green” media
Radical cyclisation continues to be a central methodology for the preparation of natural products containing heterocyclic rings.
Hence, some electrochemical results obtained by cyclic voltammetry and controlled-potential electrolysis in the study of electroreductive intramolecular cyclisation of ethyl (2S, 3R)-2-
bromo-3-propargyloxy-3-(2’,3’,4’,6’-tetra-O-acetyl-β-D-glucopyranosiloxy) propanoate (1) promoted by (1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetra-decane)nickel(I), [Ni(tmc)]+,
electrogenerated at glassy carbon cathodes in ethanol and ethanol/water mixtures containing tetraalkylammonium salts, are
presented.
During controlled-potential electrolyses of solutions containing [Ni(tmc)]2+ and acetylated D-glucose-based bromo propargyl ester (1) catalytic reduction of the latter proceeds via one-electron cleavage of the carbon–bromine bond to form a radical
intermediate that undergoes cyclization to afford the substituted tetrahydrofurans.Fundação para a Ciência e a Tecnologia (FCT
Diffractive Dissociation In The Interacting Gluon Model
We have extended the Interacting Gluon Model (IGM) to calculate diffractive
mass spectra generated in hadronic collisions. We show that it is possible to
treat both diffractive and non-diffractive events on the same footing, in terms
of gluon-gluon collisions. A systematic analysis of available data is
performed. The energy dependence of diffractive mass spectra is addressed. They
show a moderate narrowing at increasing energies. Predictions for LHC energies
are presented.Comment: 12 pages, latex, 14 figures (PostScript Files included); accepted for
publication in Phys. Rev. D (Feb.97
Learning frequent behaviors patterns in intelligent environments for attentiveness level
Nowadays, when it comes to achieving goals in business environments
or educational environments, the performance successfully has an important
role in performing a task. However, this performance can be affected by
several factors. One of the most common is the lack of attention. The individual’s
attention in performing a task can be determinant for the final quality or
even at the task’s conclusion. In this paper is intended to design a solution that
can reduce or even eliminate the lack of attention on performing a task. The
idea consist on develop an architecture that capture the user behavior through
the mouse and keyboard usage. Furthermore, the system will analyze how the
devices are used.This work has been supported by COMPETE: POCI-01-0145-FEDER-007043 and
FCT – Fundação para a Ciência e Tecnologia within the Project Scope:
UID/CEC/00319/2013.info:eu-repo/semantics/publishedVersio
Progress in the determination of the cross section
Improving previous calculations, we compute the cross section using QCD sum rules. Our sum rules for the , , and hadronic
matrix elements are constructed by using vaccum-pion correlation functions, and
we work up to twist-4 in the soft-pion limit. Our results suggest that, using
meson exchange models is perfectly acceptable, provided that they include form
factors and that they respect chiral symmetry. After doing a thermal average we
get mb at T=150\MeV.Comment: 22 pages, RevTeX4 including 7 figures in ps file
Differential modulation of cancellous and cortical distal femur by fructose and natural mineral-rich water consumption in ovariectomized female sprague dawley rats
Bone mineral density (BMD) and microstructure depend on estrogens and diet. We assessed the impact of natural mineral-rich water ingestion on distal femur of fructose-fed estrogen-deficient female Sprague Dawley rats. Ovariectomized rats drank tap or mineral-rich waters, with or without 10%-fructose, for 10 weeks. A sham-operated group drinking tap water was included (n = 6/group). Cancellous and cortical bone compartments were analyzed by microcomputed tomography. Circulating bone metabolism markers were measured by enzyme immunoassay/enzyme-linked immunosorbent assay or multiplex bead assay. Ovariectomy significantly worsened cancellous but not cortical bone, significantly increased circulating degradation products from C-terminal telopeptides of type I collagen and receptor activator of nuclear factor-kappaB ligand (RANKL), and significantly decreased circulating osteoprotegerin and osteoprotegerin/RANKL ratio. In ovariectomized rats, in cancellous bone, significant water effect was observed for all microstructural properties, except for the degree of anisotropy, and BMD (neither a significant fructose effect nor a significant interaction between water and fructose ingestion effects were observed). In cortical bone, it was observed a significant (a) water effect for medullary volume and cortical endosteal perimeter; (b) fructose effect for cortical thickness, medullary volume, cross-sectional thickness and cortical endosteal and periosteal perimeters; and (c) interaction effect for mean eccentricity. In blood, significant fructose and interaction effects were found for osteoprotegerin (no significant water effect was seen). For the first time in ovariectomized rats, the positive modulation of cortical but not of cancellous bone by fructose ingestion and of both bone locations by natural mineral-rich water ingestion is described.This work was supported by FEDER—Fundo Europeu de Desenvolvimento Regional (through NORTE 2020 Programa Operacional Regional do Norte—NORTE-01-0145-FEDER-000012), Unicer Bebidas, S.A., Portugal and by FCT—Fundação para a Ciência e Tecnologia (SFRH/BDE/33798/2009 to CP; SFRH/BD/71149/2010 to EP; SFRH/BD/79716/2011 to NS and UID/BIM/04293/2013 to Instituto de Investigação e Inovação em Saúde (Projeto Estratégico)). When considering the funding by Unicer Bebidas, S.A., it should be mentioned that the study here presented was developed, in its full extent, both in scientific terms and research equipment conditions, independently of the beverage company
Fabrication of low electrical percolation threshold multi-walled carbon nanotube sensors using magnetic patterning
Soft robotics is an expanding area with multiple applications; however, building low-cost, soft, and flexible robots requires the development of sensors that can be directly integrated into the soft robotics fabrication process. Thus, the motivation for this work was the design of a low-cost fabrication process of flexible sensors that can detect touch and deformation. The fabrication process proposed uses a flexible polymer nanocomposite with permanent magnets strategically placed where the conductive electrodes should be. The nanocomposite is based on poly(dimethylsiloxane) (PDMS) and multi-walled carbon nanotubes (MWCNTs). The MWCNT contains ferromagnetic impurities remaining from the synthesis process, which can be used for magnetic manipulation. Several electrode geometries were successfully simulated and tested. The magnetic patterning was simulated, allowing the fabrication of conductive patterns within the composite. This fabrication process allowed the reduction of the electrical resistivity of the nanocomposites as compared to the composites with homogeneous MWCNT dispersion. It also allowed the fabrication of piezoresistive and triboelectric sensors at MWCNT concentration as low as 0.5 wt.%. The fabrication process proposed is flexible, allows the development of sensors for soft robotics, as well as monitoring large and unconventional areas, and may be adapted to different mould shapes and polymers at low cost.This research is part of the PhD project at the Doctoral Program in Advanced Materials and Processing—FEUP. We would like to thank CeNTI for providing resources (labs, equipment and consumables) to perform the fabrication and characterisation of the samples. The authors thank CEMUP for expert assistance (Rui Rocha) with SEM-EDS. IPC acknowledges the support of FCT through National Funds References UIDB/05256/2020 and UIDP/05256/2020
Estimating the inelasticity with the information theory approach
Using the information theory approach, in both its extensive and nonextensive
versions, we estimate the inelasticity parameter of hadronic reactions
together with its distribution and energy dependence from and
data. We find that the inelasticity remains essentially constant in energy
except for a variation around , as was originally expected.Comment: 14 pages, 8 figures. Misprints correcte
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