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Search Results: 1 - 10 of 472567 matches for " L. H. P.;Lapa "
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Development and evaluation of a radial anaerobic/aerobic reactor treating organic matter and nitrogen in sewage
Garbossa, L. H. P.;Lapa, K. R.;Zaiat, M.;Foresti, E.;
Brazilian Journal of Chemical Engineering , 2005, DOI: 10.1590/S0104-66322005000400003
Abstract: the design and performance of a radial anaerobic/aerobic immobilized biomass (raaib) reactor operating to remove organic matter, solids and nitrogen from sewage are discussed. the bench-scale raaib was divided into five concentric chambers. the second and fourth chambers were packed with polyurethane foam matrices. the performance of the reactor in removing organic matter and producing nitrified effluent was good, and its configuration favored the transfer of oxygen to the liquid mass due to its characteristics and the fixed polyurethane foam bed arrangement in concentric chambers. partial denitrification of the liquid also took place in the raaib. the reactor achieved an organic matter removal efficiency of 84%, expressed as chemical oxygen demand (cod), and a total kjeldahl nitrogen (tkn) removal efficiency of 96%. average cod, nitrite and nitrate values for the final effluent were 54 mg.l-1, 0.3 mg.l-1 and 22.1 mg.l-1, respectively.
Protective effects of phosphodiesterase inhibitors on lung function and remodeling in a murine model of chronic asthma
Campos, H.S.;Xisto, D.G.;Oliveira, M.B.G.;Teixeira, I.;Negri, E.M.;Mauad, T.;Carnielli, D.;Lima, L.M.;Barreiro, E.J.;Faffe, D.S.;Zin, W.A.;Lapa e Silva, J.R.;Rocco, P.R.M.;
Brazilian Journal of Medical and Biological Research , 2006, DOI: 10.1590/S0100-879X2006000200016
Abstract: the aim of the present study was to compare the efficacy of a novel phosphodiesterase 4 and 5 inhibitor, lassbio596, with that of dexamethasone in a murine model of chronic asthma. lung mechanics (airway resistance, viscoelastic pressure, and static elastance), histology, and airway and lung parenchyma remodeling (quantitative analysis of collagen and elastic fiber) were analyzed. thirty-three balb/c mice were randomly assigned to four groups. in the asthma group (n = 9), mice were immunized with 10 μg ovalbumin (ova, ip) on 7 alternate days, and after day 40 they were challenged with three intratracheal instillations of 20 μg ova at 3-day intervals. control mice (n = 8) received saline under the same protocol. in the dexamethasone (n = 8) and lassbio596 (n = 8) groups, the animals of the asthma group were treated with 1 mg/kg dexamethasone disodium phosphate (0.1 ml, ip) or 10 mg/kg lassbio596 dissolved in dimethyl sulfoxide (0.2 ml, ip) 24 h before the first intratracheal instillation of ova, for 8 days. airway resistance, viscoelastic pressure and static elastance increased significantly in the asthma group (77, 56, and 76%, respectively) compared to the control group. the asthma group presented more intense alveolar collapse, bronchoconstriction, and eosinophil and neutrophil infiltration than the control group. both lassbio596 and dexamethasone inhibited the changes in lung mechanics, tissue cellularity, bronchoconstriction, as well as airway and lung parenchyma remodeling. in conclusion, lassbio596 at a dose of 10 mg/kg effectively prevented lung mechanical and morphometrical changes and had the potential to block fibroproliferation in a balb/c mouse model of asthma.
Intestinal Helminthiasis and Anaemia in Youngsters from Matriz da Luz, District of S?o Louren?o da Mata, State of Pernambuco, Brazil
Ferreira, Maria Rejane;Souza, Wayner;Perez, Emília P;Lapa, Tiago;Carvalho, Alexandre B;Furtado, André;Coutinho, Hélio B;Wakelin, Derek;
Memórias do Instituto Oswaldo Cruz , 1998, DOI: 10.1590/S0074-02761998000300002
Abstract: a group of youngsters (4-18 years old) in northeast brazil was studied to establish the prevalence of anaemia and intestinal parasitism, as well as to analyze the correlation between them. two criteria were used to determine the state of anaemia, the level of haemoglobin and the mean of corpuscular volume. the first was considered a single criterion and the second an associated criteria, used in an attempt to correlate anaemia with iron deficiency. the prevalence of intestinal parasitism was 93%, while the prevalence of anaemia was 43.1% and 16.1% according to the criteria employed (single or associated respectively). anaemia was significantly associated with both sex and age. no significant statistical difference was observed when the association was made between each parasite and anaemia even with those more related to anaemia.
Swimming at Low Reynolds Number in Fluids with Odd (Hall) Viscosity
Matthew F. Lapa,Taylor L. Hughes
Physics , 2013, DOI: 10.1103/PhysRevE.89.043019
Abstract: We apply the geometric theory of swimming at low Reynolds number to the study of nearly circular swimmers in two-dimensional fluids with non-vanishing Hall, or "odd", viscosity. The Hall viscosity gives an off-diagonal contribution to the fluid stress-tensor, which results in a number of striking effects. In particular, we find that a swimmer whose area is changing will experience a torque proportional to the rate of change of the area, with the constant of proportionality given by the coefficient $\eta^o$ of odd viscosity. After working out the general theory of swimming in fluids with Hall viscosity for a class of simple swimmers, we give a number of example swimming strokes which clearly demonstrate the differences between swimming in a fluid with conventional viscosity and a fluid which also has a Hall viscosity. A number of more technical results, including a proof of the torque-area relation for swimmers of more general shape, are explained in a set of appendices.
Ground States of the Classical Antiferromagnet on the Pyrochlore Lattice
Matthew F. Lapa,Christopher L. Henley
Physics , 2012,
Abstract: We study the classical ground states of the exchange-coupled Heisenberg antiferromagnet on the Pyrochlore lattice, a non-Bravais lattice made of corner-sharing tetrahedra. In particular, we map out the entire phase diagram for the case of first and second nearest neighbor interactions. In this phase diagram we find {\it four} complex non-coplanar ground states based on different ordering modes. These are the Cuboctahedral Stack state, a $<111>$ stacking of Cuboctahedral states, and three families of commensurate spiral: the Kawamura states, constructed from three different combinations of $\{\tfrac{3}{4}\tfrac{3}{4}0\}$ modes, the Double-Twist state, also constructed from $\{\tfrac{3}{4}\tfrac{3}{4}0\}$ modes, and the Multiply-Modulated Commensurate Spiral state, constructed from $\{\tfrac{3}{4}\tfrac{1}{4}\tfrac{1}{2}\}$ modes. We also briefly look at states involving the two kinds of third nearest neighbor interactions on the Pyrochlore lattice. In this region of parameter space we again find the Cuboctahedral Stack state, and we also find another non-coplanar state in the form of a new kind of Alternating Conic Spiral.
Probability distribution of the order parameter in the directed percolation universality class
P. H. L. Martins
Physics , 2012, DOI: 10.1103/PhysRevE.85.041110
Abstract: The probability distributions of the order parameter for two models in the directed percolation universality class were evaluated. Monte Carlo simulations have been performed for the one-dimensional generalized contact process and the Domany-Kinzel cellular automaton. In both cases, the density of active sites was chosen as the order parameter. The criticality of those models was obtained by solely using the corresponding probability distribution function. It has been shown that the present method, which has been successfully employed in treating equilibrium systems, is indeed also useful in the study of nonequilibrium phase transitions.
Bronchial hyperresponsiveness and analysis of induced sputum cells in Crohn's disease
Bartholo, R.M.;Zaltman, C.;Elia, C.;Cardoso, A.P.;Flores, V.;Lago, P.;Cassabian, L.;Carvalho Dorileo, F.;Lapa-e-Silva, J.R.;
Brazilian Journal of Medical and Biological Research , 2005, DOI: 10.1590/S0100-879X2005000200007
Abstract: with the aim of investigating the presence of latent inflammatory process in the lungs of patients with crohn's disease, 15 patients with crohn's disease were evaluated by spirometry, the methacholine challenge test, induced sputum, and skin tests for inhaled antigens. serum ige, erythrocyte sedimentation rate and hematocrit were also determined. the patients were compared with 20 healthy controls by the mann-whitney and fisher exact tests. their respiratory physical examination was normal. none had a personal or family history of clinical atopy. none had a previous history of pulmonary disease, smoking or toxic bronchopulmonary exposure. none had sinusitis, migraine, diabetes mellitus, or cardiac failure. four (26.6%) of the patients with crohn's disease had a positive methacholine challenge test whereas none of the 20 controls had a positive methacholine test (p = 0.026, fisher exact test). patients with crohn's disease had a higher level of lymphocytes in induced sputum than controls (mean 14.59%, range 3.2-50 vs 5.46%, 0-26.92%, respectively; p = 0.011, mann-whitney test). patients with crohn's disease and a positive methacholine challenge test had an even higher percentage of lymphocytes in induced sputum compared with patients with crohn's disease and a negative methacholine test (mean 24.88%, range 12.87-50 vs 10.48%, 3.2-21.69%; p = 0.047, mann-whitney test). the simultaneous findings of bronchopulmonary lymphocytosis and bronchial hyperresponsiveness in patients with crohn's disease were not reported up to now. these results suggest that patients with crohn's disease present a subclinical inflammatory process despite the absence of pulmonary symptoms.
Search for magnetically quiet CHAMP polar passes and the characteristics of ionospheric currents during the dark season
P. Ritter ,H. Lühr
Annales Geophysicae (ANGEO) , 2006,
Abstract: The magnetic activity at auroral latitudes is strongly dependent on season. During the dark season, when the solar zenith angle in the polar region is larger than 100° at all local times, the ionospheric conductivity is much reduced, and generally low activity is encountered. These time intervals are of special interest for the main field modelling, because then the geomagnetic field readings, in particular the field magnitude, are only slightly affected by ionospheric currents. Based on CHAMP data, this study examines how these quiet periods are reflected in the different magnetic field components. The peak FAC density is used as a possible proxy for the deviation of the total field. As a second option, the transverse field component, which is aligned with the auroral oval, is investigated, because it presents a measure for the FAC total current. Correlation analyses with the scalar residuals are performed and both proxies are tested for their suitability of predicting the intensity of the auroral electrojet during the dark polar seasons. The indicators based on the local FAC strength or on the amplitude of the transverse component show a reasonable correlation with the electrojet intensity for these periods, but fail when limited to small amplitudes. The predictability improves considerably if the time sector is limited to dayside hours (08:00–16:00 MLT). As the activity at high latitudes is strongly controlled by the solar wind input, we also consider IMF quantities which may support very quiet conditions. Correlations of the magnetic field scalar residuals with the merging electric field are strongest if only passes in the dayside sector are considered. Best selection results for quiet passes are obtained by combining four conditions: dark season, small average merging electric field, Em<0.8 mV/m, absence of peak values of Em>1.2 mV/m during a time interval of 40 min centred at the polar crossing, and limitation to the dayside sector (08:00–16:00 MLT). The set of quiet polar passes identified by these criteria may be used beneficially in crustal field modelling of the polar regions.
Near-Earth magnetic signature of magnetospheric substorms and an improved substorm current model
P. Ritter ,H. Lühr
Annales Geophysicae (ANGEO) , 2008,
Abstract: Based on a comprehensive catalogue with more than 4000 magnetospheric substorm entries from the years 2000–2005, the spatial distribution of the substorm-related magnetic signatures at mid and low latitudes around local midnight was investigated. Superposed epoch analysis of a larger number of recent observatory data from mid and low latitudes revealed a field strength increase that is consistent with the results of earlier studies. For the first time, the magnetic signature of the substorm current wedge formation is studied also in near-Earth satellite data from CHAMP. The average maximal deflection measured on board the satellite is smaller by a factor of 2 than that determined from ground observations. The recurrence frequency of substorms as well as the amplitude of their magnetic signature depends strongly on the prevailing magnetic activity. The observed average substorm-related magnetic field signatures cannot be described adequately by a simple current wedge model. A satisfactory agreement between model results and observations at satellite height and on ground can be achieved only if the current reconfiguration scenario combines four elements: (1) the gradual decrease of the tail lobe field, (2) the re-routing of a part of the cross-tail current through the ionosphere, (3) eastward ionospheric currents at low and mid latitudes driven by Region-2 field-aligned currents, and (4) a partial ring current connected to these Region-2 FACs.
Tratamiento comportamental del asma infantil
Carlos Pál H?gedus
Revista Latinoamericana de Psicología , 1988,
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