Resposta de cultivares de milho-pipoca a doses de adubação de semeadura.

Este trabalho teve o objetivo de verificar a resposta de cultivares de milho-pipoca, quanto à produtividade e a qualidade da pipoca, a duas doses de adubação na semeadura, em três locais do Estado de Minas Gerais. Foram avaliados oito cultivares de milho-pipoca, em dois experimentos, em Lavras, Ijaci e Sete Lagoas, nos anos agrícolas de 2000/01 e 2001/02. Em um dos experimentos de cada local foram utilizados, na adubação de semeadura, 250 kg.ha-1 da formulação 8 (N): 28 (P2O5): 16 (K2O) e, no Outro experimento, 500 kg.ha -1 da mesma formulação. A adubação de cobertura foi semelhante em ambos os experimentos. O delineamento experimental foi o de blocos casualizados com quatro repetições. Foram avaliados o peso de grão (kg.ha'-1) e a capacidade de expansão (ml/g). Os resultados permitiram concluir que existe resposta para a maior dose de adubação de semeadura apenas em relação à produtividade de grãos que, em média, é de 10%, quando comparada à menor dose; o aumento da dose de adubação de semeadura não altera a capacidade de expansão e, conseqüentemente, a qualidade da pipoca, independentemente do cultivar, local e ano agrícola; o desempenho dos cultivares, quanto à produção de grãos e capacidade de expansão, varia com o ano e o local; os cultivares IAC-112, Ames-4198 e Zélia associam boas produtividades e capacidade dos expansão de grãos

Estabilidade de cultivares de milho-pipoca em diferentes ambientes, no Estado de Minas Gerais.

O desempenho das cultivares de milho-pipoca varia com os ambientes, de modo que uma cultivar dificilmente é a melhor em todas as condições de cultivo. A resposta diferenciada das cultivares à variação ambiental denomina-se interação genótipo por ambientes. Este trabalho teve como objetivo estimar a adaptabilidade e estabilidade de cultivares de milho-pipoca quando estas foram submetidas a diferentes doses de adubação de semeadura, em diferentes locais e anos agrícolas, no estado de Minas Gerais. Foram avaliadas oito cultivares de milho-pipoca, utilizando duas doses de adubação de semeadura, em Lavras, Ijaci e Sete Lagoas, nos anos agrícolas de 2000/01 e 2001/02, perfazendo 12 ambientes. Em um dos experimentos de cada local foram utilizados 250 kg.ha-1 da formulação 8 (N): 28 (P2O5): 16 (K2O) na adubação de semeadura, e no outro experimento, 500 kg.ha-1 da mesma formulação. A adubação de cobertura foi semelhante para ambos os experimentos. O delineamento experimental para cada experimento foi o de blocos casualizados, com quatro repetições. Cada experimento foi considerado um ambiente, uma vez que foram conduzidos em diferentes locais, doses de adubação e anos agrícolas. Os resultados obtidos em todos os experimentos foram submetidos à análise de variância conjunta, considerando o peso de grão (Kg.ha-1) e a capacidade de expansão (m1.g-1). Os parâmetros que avaliaram a adaptabilidade e estabilidade foram estimados a partir das metodologias de Eberhart e Russell (1966) e Annicchiarico (1992). As cultivares diferiram quanto à adaptabilidade e estabilidade para o peso de grão, não sendo observado o mesmo para a capacidade de expansão. As cultivares Zélia, IAC 112 e Ames-4198 apresentaram os melhores resultados para a produção de grãos, 2.710, 2.728 e 2.696 kg.ha-1 e capacidade de expansão, 28,6, 27,6 e 27,5 ml.g-1, respectivamente, tanto para ambientes favoráveis como desfavoráveis. Esses cultivares apresentaram comportamento previsível e alto índice de confiança na recomendação para as regiões avaliadas

The OPERA magnetic spectrometer

The OPERA neutrino oscillation experiment foresees the construction of two magnetized iron spectrometers located after the lead-nuclear emulsion targets. The magnet is made up of two vertical walls of rectangular cross section connected by return yokes. The particle trajectories are measured by high precision drift tubes located before and after the arms of the magnet. Moreover, the magnet steel is instrumented with Resistive Plate Chambers that ease pattern recognition and allow a calorimetric measurement of the hadronic showers. In this paper we review the construction of the spectrometers. In particular, we describe the results obtained from the magnet and RPC prototypes and the installation of the final apparatus at the Gran Sasso laboratories. We discuss the mechanical and magnetic properties of the steel and the techniques employed to calibrate the field in the bulk of the magnet. Moreover, results of the tests and issues concerning the mass production of the Resistive Plate Chambers are reported. Finally, the expected physics performance of the detector is described; estimates rely on numerical simulations and the outcome of the tests described above.Comment: 6 pages, 10 figures, presented at the 2003 IEEE-NSS conference, Portland, OR, USA, October 20-24, 200

Fibrin clot adhesion to conditioned root surfaces: an in vitro study with scanning electron microscopy analysis

Aim: Periodontal regeneration is contingent on the adhesion and maturation of fibrin clot to a root surface exposed to periodontal disease. Root surface demineralization in vitro improves the formation of a stable union between the fibrin clot and the root surface. In scientific literature there are not studies of comparison that stand which demineralizing agent is the best in promoting fibrin clot adhesion. The aim of this study was to evaluate and compare the efficacy of six root conditionings in removing the smear layer and developing the fibrin clot in static and dynamic conditions. Methods: 36 single-root teeth extracted for periodontal disease were cut with a microtome in order to obtain 72 specimens that were divided in three groups: 24 samples not covered with blood, 24 covered with fresh human whole blood, 24 covered with blood and rinsed in a rotary shaker table (Vortex\uae). 4 specimens from each group were conditioned for 3 minutes with: physiological saline solution (FISIO) as the control group, saturated solution of citric acid 25% (AC), ethylenediaminetetraacetic acid 24% (EDTA), a solution of tetracycline 200mg/mL (TETRA), a solution of tetracycline and citric acid (TETRA+AC), Prefgel\uae and successively Emdogain\uae (EMD). Then the 48 samples from group 2 and 3 were covered with blood, which was allowed to coagulate for 20 minutes in a 37\ub0C chamber. The blocks were rinsed and dehydrated under standardized conditions; specimens of group 3 were vortexed (100rpm). All the blocks were then sputtered with gold and analyzed with SEM. SEM images were evaluated by two blinded examiners, starting from the cementoenamel junction (CEJ), at 5 standardized points 2 mm distant from each other. A statistical analysis was performed. Results: EMD samples showed a more disorganized smear layer, in which is probably present the residual vehicle (propylene glycol alginate). However, in the 90% of all the specimens smear layer was found. AC treated samples showed a firmly adherent fibrin clot that covered the surfaces for the 70% of the specimens (the data was statistically relevant). Same results were found in TETRA+AC samples. The conditioning with EDTA, TETRA and EMD resulted in a sparsely organized clot worsened by the application of tensile forces, especially in TETRA samples. Only few blood cells without any clot organization were found in the control group, confirming that conditioning root surfaces improves the fibrin clot adhesion. Conclusion: The best formation of fibrin clot was observed for AC treated samples; this is probably due to the increase of root surface wettability caused by AC. The other root conditioning agents, even if lead to results better than the control group, are more susceptible to external forces and do not promote a stable fibrin clot adhesion

Signal modeling of high-purity Ge detectors with a small read-out electrode and application to neutrinoless double beta decay search in Ge-76

The GERDA experiment searches for the neutrinoless double beta decay of Ge-76 using high-purity germanium detectors enriched in Ge-76. The analysis of the signal time structure provides a powerful tool to identify neutrinoless double beta decay events and to discriminate them from gamma-ray induced backgrounds. Enhanced pulse shape discrimination capabilities of "Broad Energy Germanium" detectors with a small read-out electrode have been recently reported. This paper describes the full simulation of the response of such a detector, including the Monte Carlo modeling of radiation interaction and subsequent signal shape calculation. A pulse shape discrimination method based on the ratio between the maximum current signal amplitude and the event energy applied to the simulated data shows quantitative agreement with the experimental data acquired with calibration sources. The simulation has been used to study the survival probabilities of the decays which occur inside the detector volume and are difficult to assess experimentally. Such internal decay events are produced by the cosmogenic radio-isotopes Ge-68 and Co-60 and the neutrinoless double beta decay of Ge-76. Fixing the experimental acceptance of the double escape peak of the 2.614 MeV photon to 90%, the estimated survival probabilities at Qbb = 2.039 MeV are (86+-3)% for Ge-76 neutrinoless double beta decays, (4.5+-0.3)% for the Ge-68 daughter Ga-68, and (0.9+0.4-0.2)% for Co-60 decays.Comment: 27 pages, 17 figures. v2: fixed typos and references. Submitted to JINS

Production of J/psi Mesons at HERA

Inelastic and diffractive production of J/psi mesons at HERA is reviewed. The data on inelastic photoproduction are described well within errors by the Colour Singlet Model in next-to-leading order. A search for colour octet processes predicted within the NRQCD/factorisation approach is conducted in many regions of phase space. No unambiguous evidence has been found to date. Diffractive elastic production of J/psi mesons has been measured in the limit of photoproduction up to the highest photon proton center of mass energies. The increase of the cross section is described by pQCD models. At larger Q^2, the W dependence is found to be similar to that observed in photoproduction. First analyses of data at high t yield a powerlike dependence on |t|. A LO BFKL calculation gives a good description of the data.Comment: 14 pages, 12 figures, contribution to Ringberg 200

Tensile bond strength and SEM analysis of enamel etched with Er:YAG laser and phosphoric acid: a comparative study In vitro

Er:YAG laser has been studied as a potential tool for restorative dentistry due to its ability to selectively remove oral hard tissue with minimal or no thermal damage to the surrounding tissues. The purpose of this study was to evaluate in vitro the tensile bond strength (TBS) of an adhesive/composite resin system to human enamel surfaces treated with 37% phosphoric acid, Er:YAG laser (lambda=2.94 mum) with a total energy of 16 J (80 mJ/pulse, 2Hz, 200 pulses, 250 ms pulse width), and Er:YAG laser followed by phosphoric acid etching. Analysis of the treated surfaces was performed by scanning electron microscopy (SEM) to assess morphological differences among the groups. TBS means (in MPa) were as follows: Er:YAG laser + acid (11.7 MPa) > acid (8.2 MPa) > Er:YAG laser (6.1 MPa), with the group treated with laser+acid being significantly from the other groups (p=0.0006 and p= 0.00019, respectively). The groups treated with acid alone and laser alone were significantly different from each other (p=0.0003). The SEM analysis revealed morphological changes that corroborate the TBS results, suggesting that the differences in TBS means among the groups are related to the different etching patterns produced by each type of surface treatment. The findings of this study indicate that the association between Er:YAG laser and phosphoric acid can be used as a valuable resource to increase bond strength to laser-prepared enamel.A tecnologia a laser tem sido estudada como uma ferramenta potencial para uso em odontologia devido à sua habilidade em remover tecido ósseo com um mínimo ou nenhum dano aos tecidos vizinhos. O objetivo deste estudo é comparar in vitro a resistência à tração do sistema adesivo em esmalte tratado com ácido fosfórico a 37 %, laser Er:YAG (lambda=2,94 mim) com energia total de 16 J (80 mJ/pulso, 2 Hz, 200 pulsos e largura de pulso de 250 ms) e com a combinação laser Er:YAG seguido por ácido fosfórico. O teste de resistência à tração foi usado para comparar a resistência à tração em cada grupo. Foi também realizada microscopia eletrônica de varredura para permitir a análise das diferenças morfológicas entre os grupos. Foram obtidos os seguintes valores médios de resistência para os grupos tratados com: laser (6,1 MPa), ácido fosfórico (8,2 MPa) e laser mais ácido (11,7 Mpa). Amostras tratadas com laser e ácido apresentaram valores maiores de resistência do que amostras com laser ou ácido isoladamente. A análise da microscopia eletrônica revelou diferenças que corroboram os resultados, demonstrando que diferenças de resistência entre os grupos são devidas às diferenças entre os padrões superficiais resultantes. Nossos resultados sugerem que a combinação do laser Er:YAG com ácido fosfórico pode ser usada como um método para aumentar a resistência à tração do sistema esmalte resina