1,601 research outputs found
Basis invariant conditions for supersymmetry in the two-Higgs-doublet model
The minimal supersymmetric standard model involves a rather restrictive Higgs
potential with two Higgs fields. Recently, the full set of classes of
symmetries allowed in the most general two Higgs doublet model was identified;
these classes do not include the supersymmetric limit as a particular class.
Thus, a physically meaningful definition of the supersymmetric limit must
involve the interaction of the Higgs sector with other sectors of the theory.
Here we show how one can construct basis invariant probes of supersymmetry
involving both the Higgs sector and the gaugino-higgsino Higgs interactions.Comment: RevTex, 11 pages, v2-small section adde
Ânforas da Villa Romana de Vilares de Alfundão (Ferreira do Alentejo)
Os autores estudam um conjunto anfórico recolhido nos restos conservados à superfÃcie de uma villa romana, Vilares de Alfundão (Ferreira do Alentejo).
Da análise tipológica e do estudo das pastas cerâmicas, conclui-se que a maioria terá sido fabricada nos fornos do Baixo Sado, predominando largamente as formas Dressel 14b e Almagro 51c. Tais resultados são comparados e discutidos, especialmente com os obtidos do estudo das ânforas de S. Cucufate (Vidigueira). Em dois fundos de ânforas DresseI 14 aparece o mesmo grafito e um dos exemplares da forma Almagro 50 ostenta na asa a marca [ . .. ] CVRVCVNIN
Mass-degenerate Higgs bosons at 125 GeV in the Two-Higgs-Doublet Model
The analysis of the Higgs boson data by the ATLAS and CMS Collaborations
appears to exhibit an excess of h --> gamma\gamma events above the Standard
Model (SM) expectations; whereas no significant excess is observed in h --> ZZ*
--> {four lepton} events, albeit with large statistical uncertainty due to the
small data sample. These results (assuming they persist with further data)
could be explained by a pair of nearly mass-degenerate scalars, one of which is
a SM-like Higgs boson and the other is a scalar with suppressed couplings to
W+W- and ZZ. In the two Higgs doublet model, the observed \gamma\gamma and ZZ*
--> {four lepton} data can be reproduced by an approximately degenerate CP-even
(h) and CP-odd (A) Higgs boson for values of \sin(\beta-\alpha) near unity and
0.7 < \tan\beta < 1. An enhanced \gamma\gamma signal can also arise in cases
where m_h ~ m_H, m_H ~ m_A, or m_h ~ m_H ~ m_A. Since the ZZ* --> {four lepton}
signal derives primarily from a SM-like Higgs boson whereas the \gamma\gamma
signal receives contributions from two (or more) nearly mass-degenerate states,
one would expect a slightly different invariant mass peak in the ZZ* --> {four
lepton} and \gamma\gamma channels. The phenomenological consequences of such
models can be tested with additional Higgs data that will be collected at the
LHC in the near future.Comment: 18 pages, 19 pdf figures, v2: references added, v3&v4: added refs and
explanation
Polichromatic image sensor with microlenses for stereoscopic acquisition
This paper presents the fabrication of microlenses for
integration on a stereoscopic image sensor in CMOS technology
and a low-cost technology for fabricating optical filters arrays
tuned for the primary colors. The material selected for
fabricating the microlens was the AZ4562 positive photoresist
and the fabrication process explained. Moreover, the fabrication
process presented in this paper is for directly printing the optical
filters into a transparent flexible substrate (acetate).This work was fully supported by the Portuguese
Foundation for Science and Technology under the project
FCT/PTDC/EEA-ELC/109936/2009 and R. P. Rocha is
supported by the Foundation for Science and Technology
financial grant SFRH/BD/33733/2009
Sarcosine oxidase composite screen-printed electrode for sarcosine determination in biological samples
XIX Meeting of the Portuguese Electrochemical Society - XVI Iberic Meeting of ElectrochemistryProstate Cancer (PCa) is the most common form of cancer in men in Europe with a 61.4 % incidence among all cancer cases and a 12.1 % mortality [1] and, therefore, its early detection is fundamental for increasing the survival rate. Currently, diagnosis and management of patients with PCa is only based on the determination of the biomarker Prostate Specific Antigen (PSA). However, the method used for PCa detection has poor sensitivity and specificity, leading to false negative and false positive test results and many patients are sent to unnecessary biopsy procedures [2]. Therefore, there is a need to seek for new biomarkers and more effective screening. In this work, a biosensor device was developed for the quantification of sarcosine via electrochemical detection of H2O2 (at 0.6 V) generated from the catalyzed oxidation of sarcosine. The detection was carried out after the modification of carbon screen printed electrodes (SPEs) by immobilization of sarcosine oxidase (SOX) on the electrode surface. The strategies used herein included the activation of the carbon films by an electrochemical step and the formation of an NHS/EDAC layer to bond the enzyme to the electrode, the use of metallic or semiconductor nanoparticles layer previously or during the enzyme immobilization. In order to improve the sensor stability and selectivity a polymeric layer with extra enzyme content was further added. The proposed methodology for the detection of sarcosine allowed obtaining a limit of detection (LOD) of 1.6x10-5 mM, using a linear concentration range between 1x10-5 and 1x10-4 mM. The biosensor was successfully applied to the analysis of sarcosine in urine samples.
Thermoelectric generator and solid-state battery for stand-alone microsystems
This paper presents a thermoelectric (TE) generator and a solid-state battery for powering
microsystems. Prototypes of TE generators were fabricated and characterized. The TE
generator is a planar microstructure based on thin films of n-type bismuth telluride (Bi2Te3)
and p-type antimony telluride (Sb2Te3), which were deposited using co-evaporation. The
measurements on selected samples of Bi2Te3 and Sb2Te3 thin films indicated a Seebeck
coefficient in the range of 90–250 μV K−1 and an in-plane electrical resistivity in the range of
7–17 μÄ m. The measurements also showed TE figures-of-merit, ZT, at room temperatures
(T = 300 K) of 0.97 and 0.56, for thin films of Bi2Te3 and Sb2Te3, respectively (equivalent to a
power factor, PF, of 4.87 mW K−2 m−1 and 2.81 mW K−2 m−1). The solid-state battery is
based on thin films of: an anode of tin dioxide (SnO2), an electrolyte of lithium phosphorus
oxynitride (LixPOyNz, known as LiPON) and a cathode of lithium cobaltate (LiCoO2, known
as LiCO), which were deposited using the reactive RF (radio-frequency) sputtering. The
deposition and characterization results of these thin-films layers are also reported in this
paper.This work was fully supported by FCT/PTDC/EEA-ENE/66855/2006 project
Chemical constituents of Euphorbia hyberna L. (Euphorbiaceae)
Chemical investigation of the aerial part and the roots of Euphorbia hyberna
L. subs. hyberna. resulted in the isolation and identification of four triterpenoids
(3�-O-octadecanoyllupeol (1), glut-5-en-3�-ol (2), 24-methylenecicloartan-3�-ol
(3) and cicloart-23-ene-3�,25-diol (6)) along with the phenolic compounds ellagic
acid (4) and 3,30
-di-O-methylellagic acid (7). Although these are all known
compounds, this is the first report of their isolation from this plant.
Their structures were elucidated on the basis of spectral methods, including 2D
NMR experiences, and confirmed by comparing with the literature data.info:eu-repo/semantics/publishedVersio
Hybrid fuzzy Monte Carlo and logic programming model for distribution network reconfiguration in the presence of outages
This paper presents a methodology for distribution networks reconfiguration in outage presence in order to choose the reconfiguration that presents the lower power losses. The methodology is based on statistical failure and repair data of the distribution power system components and uses fuzzy-probabilistic modelling for system component outage parameters. Fuzzy membership functions of system component outage parameters are obtained by statistical records. A hybrid method of fuzzy set and Monte Carlo simulation based on the fuzzy-probabilistic models allows catching both randomness and fuzziness of component outage parameters.
Once obtained the system states by Monte Carlo simulation, a logical programming algorithm is applied to get all possible reconfigurations for every system state.
In order to evaluate the line flows and bus voltages and to identify if there is any overloading, and/or voltage violation a distribution power flow has been applied to select the feasible reconfiguration with lower power losses.
To illustrate the application of the proposed methodology to a practical case, the paper includes a case study that considers a real distribution network
Gellan-gum based bilayered scaffolds for application in osteochondral tissue engineering
Publicado em "Journal ofTissue Engineering and Regenerative Medicine", vol. 7, supp. 1 (2013)Bilayered scaffold and cellular strategies are currently applied to solve the challenging problem of osteochondral defects. In this study, several formulations of Gellan gum were developed to fabricate different scaf- folds possessing a cartilage-like layer and a bone-like layer. The bone- like layers were obtained by low acyl Gellan gum (LAGG) at 2 wt% and different amounts of hydroxyapatite powders (HAp) (5,10,15 and 20wt%). The cartilage-like layers were obtained by preparing LAGG formulation at 2wt% and formulations of LAGG at 2wt% and high acyl Gellan gum (HAGG) at 0.75wt% at a ratio of 75:25(v%). The visco- elastic measurements were performed using a TRITEC8000B DMA to characterize the mechanical behaviour of the bilayered scaffolds. The effect of the incorporation of different amount of HAp within the bone- like layer on the mechanical properties of the scaffolds was also investi- gated. Degradation and water uptake studies were performed by soak- ing the scaffolds in a phosphate buffered saline solution (pH 7.4) up to 30 days. The bilayered scaffolds were investigated by stereo microscope to evaluate the interface between both layers. The cytotoxicity of the bilayered scaffolds was investigated in vitro using a L929 cell line. In vi- tro studies regarding adhesion, encapsulation and viability of human chondrocytes (cartilage-like layer) and human osteoblasts (bone-like layer) cultured in the bilayered scaffolds were also carried by perform- ing SEM analysis and Live/Dead assays
Impact of different aquatic exercise programs on body composition, functional fitness and cognitive function of non-institutionalized elderly adults: a randomized controlled trial
Aquatic physical exercise programs have become progressively more popular among elderly people. Some of the major physical exercise program disadvantages on land are minimized due to the specific properties of the aquatic environment. The purpose of the present randomized controlled study is to verify the effects of different aquatic physical exercise programs on body composition, functional fitness and cognitive function in non-institutionalized elderly people. For this study, 102 elderly individuals were randomly allocated into four different groups: AerG (n = 25, 71.44 ± 4.84 years); IntG (n = 28, 72.64 ± 5.22 years); ComG (n = 29, 71.90 ± 5.67 years) and CG (n = 20, 73.60 ± 5.25 years). Individuals from the groups AerG, IntG and ComG participated in three different aquatic physical exercise programs for a period of 28 weeks. The CG participants kept to their usual routines. All participants were evaluated for body composition, functional fitness and cognitive function at two time moments, i.e., pre- (M1) and post-intervention (M2). Significant differences for body composition were found between M1 and M2 for FM (p < 0.001), LBM (p < 0.001) and WCir (p < 0.01) in the AerG, for BMI (p < 0.05), FM (p < 0.05), LBM (p < 0.001) and LCir-R (p < 0.05) in the IntG, and for WGT (p < 0.01), FM (p < 0.05), LBM (p < 0.01), LCir-R (p < 0.05) and LCir-L (p < 0.01) in the ComG groups. For functional fitness, differences were found between M1 and M2 for 2m-ST (p < 0.000), 30s-CS (p < 0.000), 30s-AC (p < 0.05), HG-T-R (p < 0.000) and HG-T-L (p < 0.000) in the AerG, for 2m-ST (p < 0.05), BS-R (p < 0.05), 30s-CS (p < 0.000), 30s-AC(p < 0.01), HG-T-R (p < 0.000) and HG-T-L (p < 0.000) in the IntG, and for 30s-CS (p < 0.000), HG-T-R (p < 0.000) and HG-T-L (p < 0.000) in the ComG groups. The present study evidenced the beneficial effects of physical exercise in an aquatic environment on body composition, functional fitness and cognitive function in non-institutionalized elderly adults. The ComG water-based exercise program showed more beneficial effects in the improvement of body composition and cognitive function variables, while the IntG and AerG programs were more effective in the improvement of functional fitness.info:eu-repo/semantics/publishedVersio
- …