Destruction of Superconductivity by Impurities in the Attractive Hubbard Model

We study the effect of U=0 impurities on the superconducting and thermodynamic properties of the attractive Hubbard model on a square lattice. Removal of the interaction on a critical fraction of $f_{\rm crit} \approx 0.30$ of the sites results in the destruction of off-diagonal long range order in the ground state. This critical fraction is roughly independent of filling in the range $0.75 < \rho < 1.00$, although our data suggest that $f_{\rm crit}$ might be somewhat larger below half-filling than at $\rho=1$. We also find that the two peak structure in the specific heat is present at $f$ both below and above the value which destroys long range pairing order. It is expected that the high $T$ peak associated with local pair formation should be robust, but apparently local pairing fluctuations are sufficient to generate a low temperature peak

Maximum loss acceptable to risk investment in brazilian commodity.

O presente trabalho teve como objetivo simular a perda m?xima aceit?vel para o risco de investimento em uma das principais commoditiesagr?colas do Brasil, o trigo. Para o cumprimento de tal objetivo, o estudo usou a modelagem de s?ries temporais com processos autorregressivos dem?dias m?veis (Arma), heterocedasticidade condicional (Garch) e valor em risco (V@R), aplicados sobre uma s?rie hist?rica de prec?os do ativonum intervalo de dez anos. O banco de dados investigado foi coletado no site do Cepea/Esalq/USP e a motivac??o para escolha dessa s?rie hist?ricase deu em func??o da import?ncia produtiva e econ?mica do Estado do Paran? para todo o Brasil, porque ? o maior produtor e comerciante dacommodity. Os resultados discutidos neste paper revelam que a um n?vel de signific?ncia estat?stica de 1%, o produtor de trigo admite uma perdade R$228,40 sobre o investimento feito e, a 5$ 174,19. Em geral, essas informac??es sugerem que a cada tonelada de trigo vendida, o produtorpode perder em seu investimento at? R$228,40. Estas e outras informac??es abordadas na pesquisa podem servir de ferramentas estrat?gicas deapoio para o processo decis?rio de investimento em commodities. A din?mica dos prec?os expressa pela volatilidade do mercado pode revelaralgum padr?o de comportamento do ativo, o que pode ser ?til para a formac??o de pol?ticas hedge, nas quais v?rios produtores assumem o risco doinvestimento efetivado, minorando assim o impacto do mesmo sobre os produtores.VolatilidadeAbstractThis study aimed to simulate the maximum acceptable loss for the risk of investing in a major agricultural commodities in Brazil, wheat. To fulfillthis objective, the study used the modeling of time series with autoregressive processes moving average (ARMA), conditional heteroskedasticity(GARCH) and value at risk (V@R), applied on a historical series of asset prices in a ten year period. The investigation database was collectedin the site CEPEA/ESALQ/USP and the motivation for choosing this historical series was due to the productive and economic importance of theState of Paran? throughout Brazil, the largest producer and commodity trader. The results discussed in this paper show that a level of statisticalsignificance of 1$ 228.40 under the investment and 5% R$174.19. Overall, these data suggest that every tonneof wheat sold, the producer can lose on your investment up to R$ 228.40. These and other information covered in the survey may provide supportstrategic tools for decision-making investment in commodities. The dynamics of prices expressed by the market volatility may reveal some activebehavior pattern, which can be useful for the formation of hedging policies, in which various producers assume the risk of the effected investment,thus minimizing the impact of the same on producers

Controle Linear aplicado a uma nanorrede de corrente contínua que opera em modo ilhado utilizando modelo médio de pequenos sinais/ Linear Control applied to a direct current nano-network that operates in island mode using small signals medium model

As nanorredes de corrente contínua (CC) surgiram, nos últimos anos, como alternativa à crescente demanda energética das unidades consumidoras. Para nanorredes de corrente contínua, bem como todos os sistemas que operam em modo ilhado, o balanço instantâneo de potência é de grande importância para manter a tensão do barramento dentro dos limites de projeto. Para tal, nesse trabalho é feita a linearização do sistema (intrinsecamente não-linear), assim possibilitando a aplicação de técni-cas clássicas de controle. Portanto, faz-se a modelagem através de técnicas conhecidas do modelo mé-dio de pequenos sinais para obter as funções de transferência necessárias ao controle da tensão CC do barramento da nanorrede. Adicionalmente, projeta-se um sistema de controle e são obtidas as faixas de operação onde a estabilidade do sistema é garantida. A nanorrede é então testada através de simula-ções para validar o sistema de controle proposto bem como a análise da estabilidade

Third-harmonic generation in silica wedge resonators

Whispering-gallery-mode microcavities are known to have high optical quality factor, making them suitable for nonlinear optical interactions. Here, third-harmonic generation is observed using a relatively small radius wedge silicon oxide optical microcavity. The small radii wedge microdisks can be dispersion-tailored to obtain either normal or anomalous group velocity dispersion. In our case, we operate in the normal dispersion regime preventing frequency comb generation by suppressing infrared cascading four-wave mixing. This allows for a clean third harmonic generation at phase-matched visible optical modes. Tunability of the third-harmonic emission is obtained due to a combination of the thermo-optical and Kerr effects. An additional thermal control of the phase matching condition allows for optimizing third-harmonic generation, and agreement between this process and couple-mode theory is demonstrated.Comment: 6 pages, 6 figure

Anxiety and pain perception in patients undergoing mandibular autogenous block bone surgery

The aim of the present study was to investigate pain perception and anxiety within the context of surgery for the placement of mandibular block bone and to evaluate the causality effect between theses variables. A total of 13 patients were recruited for the study and were submitted to mandibular autogenous block bone surgery. Demographic data were collected and the anxiety level was determined using the State-Trait Anxiety Inventory (STAI). The STAI was administered on the day of surgery and on the 14th postoperative day. Pain was determined using the visual analogue scale (VAS) and limitation of daily activities and postoperative symptoms were also reported. Data were analyzed using parametric tests (?=0.05) and cross-lagged analysis was performed to verify a causality effect. Few patients reported interference with daily activities or the presence of postoperative symptoms. A significant association of bad breath/taste with STAI-State was detected on the 14th postoperative day. No evidence of causality between STAI and VAS was detected. The patient?s self-evaluation indicates that the pain and anxiety level felt during treatment was not directly associated with the clinical aspects of the surgical procedure or with postoperative activities/symptoms limitations

New Algorithm to Discriminate Phase Distribution of Gas-Oil-Water Pipe Flow With Dual-Modality Wire-Mesh Sensor

Three-phase gas-oil-water flow is an important type of flow present in petroleum extraction and processing. This paper reports a novel threshold-based method to visualize and estimate the cross-sectional phase fraction of gas-oil-water mixtures. A 16×16 dual-modality wire-mesh sensor (WMS) was employed to simultaneously determine the conductive and capacitive components of the impedance of fluid. Then, both electrical parameters are used to classify readings of WMS into either pure substance (gas, oil or water) or two-phase oil-water mixtures (foam is neglected in this work). Since the wire-mesh sensor interrogates small regions of the flow domain, we assume that the three-phase mixture can be segmented according to the spatial sensor resolution (typically 2–3 mm). Hence, the proposed method simplifies a complex three-phase system in several segments of single or two-phase mixtures. In addition to flow visualization, the novel approach can also be applied to estimate quantitative volume fractions of flowing gas-oil-water mixtures. The proposed method was tested in a horizontal air-oil-water flow loop in different flow conditions. Experimental results suggest that the threshold-based method is able to capture transient three-phase flows with high temporal and spatial resolution even in the presence of water-oil dispersion regardless of the continuous phase

Impact of corticosteroids on late growth of radiofrequency lesions in infant pigs: histopathological and electroanatomical findings

Aims Corticosteroids attenuate late growth of radiofrequency (RF) lesions in the thigh muscle of infant rats. We sought to assess the impact of these drugs on the late growth of RF lesions in immature swine myocardium and to determine the electroanatomical mapping (EAM) characteristics of these lesions.Methods and results Radiofrequency (60 degrees C; 60 s) lesions were created in the right atrium (n = 2) and ventricle (n = 2) of 14 piglets (age 65 days; weight 5 kg) and 3 adults. Piglets were divided into: controls (n 7) and treated (n 7), receiving hydrocortisone (10 mg/kg iv after RF) and prednisone (1 mg/kg/day) for 29 days. After 8 months, animals were sacrificed for histological analysis. in four piglets, endocardial and epicardial voltage EAM were performed.In infant groups, the dimensions of atrial (11 +/- 5 vs. 13 +/- 7 mm) and ventricular (12 +/- 3 vs. 11 +/- 3 mm) lesions were similar. in adults, atrial (6 +/- 1 mm) and ventricular (6 +/- 1 mm) lesions were smaller. in controls, ventricular lesions depicted dense fibrosis and multiple strands of fibrous tissue extending from the lesion into normal muscle. Treated piglets revealed scars exhibiting less dense fibrosis with predominance of fibroadipose tissue and less collagen proliferation. Large atrial and ventricular low-voltage areas corresponding to the macroscopic lesions were identified in all animals.Conclusion Radiofrequency lesions in infant pigs reveal late growth and invasion of normal muscle by intense collagen proliferation. Corticosteroids do not prevent late enlargement of the lesions but modulate the fibrotic proliferation. the expressive growth of the lesion may generate low-voltage areas detectable by EAM.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Universidade Federal de São Paulo, Discipline Cardiol, Paulista Sch Med, BR-04039030 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Pathol, Paulista Sch Med, BR-04039030 São Paulo, BrazilUniversidade Federal de São Paulo, Discipline Cardiol, Paulista Sch Med, BR-04039030 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Pathol, Paulista Sch Med, BR-04039030 São Paulo, BrazilWeb of Scienc

Morphological characterization of coriander genotypes

Poucas cultivares de coentro (Coriandrum sativum L.) estão disponíveis aos produtores e, em algumas regiões, cultivam-se genótipos de origem desconhecida, mantidos pelos próprios hortelãos. Para conservar as cultivares tradicionais é necessário não só coletá-las e conservá-las, mas também caracterizá-las. Dessa forma, este trabalho teve por objetivo determinar caracteres morfológicos para diferenciar genótipos de coentro no processo de registro de cultivares. Foram realizados dois experimentos, ambos em blocos casualizados, com cinco repetições. As cultivares Americano, Asteca, Palmeira, Português, Santo, Supéria, Tabocas, Tapacurá e Verdão, além da linhagem HTV-9299 foram analisadas para caracteres de fruto, plântula, folhas, folíolos e flores. Os dados obtidos foram submetidos à análise de variância univariada. A cultivar Palmeira apresentou frutos de maior tamanho e massa. Já para antocianina a cultivar Americano apresentou menor intensidade, ou praticamente ausência do pigmento tanto nas plântulas quanto nas plantas, ao contrário da cultivar Tabocas que apresentou maior intensidade. As cultivares Americano, Tabocas, Palmeira, Asteca, Verdão e Tabocas e a linhagem HTV-9299 possuem maior número de folhas basais, no entanto, as cultivares que produziram maior quantidade de massa por planta foram Tabocas, Palmeira, Verdão, HTV-9299 e Tapacurá. A cultivar Americano possui folíolo verde claro pouco amarelado, a linhagem HTV-9299 folíolo verde e a cultivar Tabocas folíolo verde escuro. Os descritores morfológicos com maior poder discriminatório para o grupo de dez cultivares avaliadas foram tamanho e massa de fruto; antocianina na plântula e planta; número de folhas basais; comprimento da quinta folha; tamanho e coloração de folíolo; número de dias para pendoamento e abertura da primeira flor e massa da planta fresca.Few coriander cultivars (Coriandrum sativum L.) are available to producers and, in some regions, are grown genotypes of unknown origin, kept by the growers themselves. To conserve such traditional crops it is necessary to collect, save, and characterize them. Thus, this study was to determine morphological characters to differentiate coriander genotypes aiming the registration of cultivars. Two trials were carried out, and the experimental design used in both was in completely randomized blocks with five replications. Americano, Asteca, Palmeira, Português, Santo, Superia, Tabocas, Tapacurá, and Verdão cultivars, and the line HTV-9299 were characterized for seedling, leaflets, leaves, fruits, and flowers. The data were subjected to a univariate ANOVA. The fruits of cv. Palmeira exhibited greater size and mass. As regards the presence of anthocyanins in seedlings and plants, cv. Americano showed the lowest intensity or slight pigmentation while cv. Tabocas had the highest pigmentation. The cultivars Americano, Palmeira, Asteca, Verdão, and Tabocas and the line HTV-9299 displayed higher number of basal leaves, however, the genotypes that produced larger amount of mass per plant were Tabocas, Palmeira, Verdão, HTV-9299, and Tapacurá. The green tone of leaflets showed differences among cultivars. So, cv. Americanos leaflets exhibited a light green, slightly yellowish color, HTV-9299 green, and Tabocas dark green. The morphological traits with higher discriminatory power for the group of the ten evaluated cultivars were: size and weight of fruits; presence or absence of anthocyanin in seedlings and plants; number of basal leaves; length of the fifth leaf; size and color of leaflets; number of days to bolting initiation, and opening of the first flower, and plant fresh mass

Genetic variability of half-sib progenies of coriander

Grande número de produtores envolve-se com o cultivo do coentro durante todo o ano, tornando a cultura importante social e economicamente. Praticamente em toda a região Nordeste utiliza-se a cultivar Verdão. Estudos da variabilidade genética do coentro são importantes, tendo em vista o melhor planejamento de programas de melhoramento genético. Desta forma, este trabalho teve como objetivo quantificar a variabilidade genética de características agronômicas do coentro cultivar Verdão, avaliando-se progênies de meios-irmãos potencialmente úteis no melhoramento genético. O trabalho foi desenvolvido na Universidade Federal Rural de Pernambuco, em casa de vegetação, em blocos casualizados, com cinco repetições e parcelas de 28 plantas, colocadas em dois vasos. Os tratamentos foram compostos por 55 progênies de meios-irmãos da cultivar Verdão. O teste t detectou significância a 1 e a 5% de probabilidade entre as correlações genotípicas, fenotípicas e ambientais. A herdabilidade no sentido amplo variou de 7,19 (peso médio de plantas) a 81,09 (número de plantas pendoadas). Para a razão entre os coeficientes de variação genético e ambiental (CVg /CVe), obteve-se de 0,27 (peso médio de plantas) a 2,07 (número de plantas pendoadas), indicando que a seleção contra o pendoamento apresenta as condições mais favoráveis em termos de ganhos genéticos imediatos. A correlação genotípica entre altura de plantas não pendoadas e número de plantas pendoadas foi alta e significativa.A large number of producers are involved in the cultivation of coriander throughout the year in Brazil, making it a crop of social and economic importance. Throughout nearly the entire Northeast Region, cultivar Verdão is used. Genetic variability studies on coriander are important for the proper planning of genetic improvement programs. The aim of the present study was to quantify the genetic variability for agronomic characteristics in cv. Verdão to contribute information toward genetic improvement. The study was developed at Universidade Federal Rural de Pernambuco, Pernambuco State, Brazil, in a greenhouse, using randomized blocks of 28 plants in two pots and five replications. The treatments were composed of 55 half-sib progenies from cultivar Verdão. The t test detected significance at 1 and 5% likelihood between the genotypic, phenotypic and environmental correlations. Broad sense heritability ranged from 7.19 for average plant weight to 81.09 for number of bolted plants. The ratio between genetic and environmental coefficients of variation (CVg/CVe) ranged from 0.27 (average weight) to 2.07 (number of bolted plants), indicating that selection against bolting presents more favorable conditions in terms of immediate genetic gains. The genotype correlation between height of non-bolted plants and the number of bolted plants was considered strong (0.86) and highly significant (t test), enabling simultaneous gains from selection