oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 145 )

2018 ( 908 )

2017 ( 932 )

2016 ( 1247 )

Custom range...

Search Results: 1 - 10 of 540278 matches for " M. G.;Costa "
All listed articles are free for downloading (OA Articles)
Page 1 /540278
Display every page Item
Superstring dualities and p-brane bound states
M. S. Costa,G. Papadopoulos
Physics , 1996, DOI: 10.1016/S0550-3213(97)00642-1
Abstract: We show that the M-theory/IIA and IIA/IIB superstring dualities together with the diffeomorphism invariance of the underlying theories require the presence of certain p-brane bound states in IIA and IIB superstring theories preserving 1/2 of the spacetime supersymmetry. We then confirm the existence of IIA and IIB supergravity solutions having the appropriate p-brane bound states interpretation.
Orthoptera, Acrididae, Leptysminae,Cylindrotettix riverae riverae Roberts, 1975: New occurrence in Brazil, expanding its South American range.
Lhano, M. G.,Costa, M. K. M.
Check List , 2008,
Abstract:
An outbreak of acute bovine mastitis caused by Klebsiella pneumoniae in a dairy herd
Silva, N.;Costa, G.M.;
Arquivo Brasileiro de Medicina Veterinária e Zootecnia , 2001, DOI: 10.1590/S0102-09352001000400001
Abstract: an outbreak of coliform mastitis is described in a dairy herd from the state of rio de janeiro, brazil. during a four-month period 14 fatal cases of klebsiella pneumoniae-related mastitis were observed in a herd of 104 lactating cows. the symptoms included peracute enterotoxemia in which the cows died 6 to 12 h after the detection of mastitis by cmt. staphylococcus aureus andstreptococcus agalactiae streptococcus agalactiae were also isolated although could not be associated with cases of acute fatal mastitis. milking practices were also evaluated. the milking machine was being used correctly and adequate precautions for hygiene and pre-milking and post-milking teat dipping were used. the organism was sensitive to gentamicin. therapy for acute toxic mastitis required early action for the treatment of infections, involving corticosteroids and fluid therapy. the use of a klebsiella vaccine produced from the microorganisms isolated from the herd, associated with hygiene measures, resulted in the control of the outbreak.
An outbreak of acute bovine mastitis caused by Klebsiella pneumoniae in a dairy herd
Silva N.,Costa G.M.
Arquivo Brasileiro de Medicina Veterinária e Zootecnia , 2001,
Abstract: An outbreak of coliform mastitis is described in a dairy herd from the State of Rio de Janeiro, Brazil. During a four-month period 14 fatal cases of Klebsiella pneumoniae-related mastitis were observed in a herd of 104 lactating cows. The symptoms included peracute enterotoxemia in which the cows died 6 to 12 h after the detection of mastitis by CMT. Staphylococcus aureus and Streptococcus agalactiae Streptococcus agalactiae were also isolated although could not be associated with cases of acute fatal mastitis. Milking practices were also evaluated. The milking machine was being used correctly and adequate precautions for hygiene and pre-milking and post-milking teat dipping were used. The organism was sensitive to gentamicin. Therapy for acute toxic mastitis required early action for the treatment of infections, involving corticosteroids and fluid therapy. The use of a Klebsiella vaccine produced from the microorganisms isolated from the herd, associated with hygiene measures, resulted in the control of the outbreak.
On submanifolds with tamed second fundamental form
G. Pacelli Bessa,M. Silvana Costa
Mathematics , 2008, DOI: 10.1017/S0017089509990085
Abstract: We show that a complete submanifold $M$ with tamed second fundamental form in a complete Riemannian manifold $N$ with sectional curvature $K_{N}\leq \kappa \leq 0$ are proper, (compact if $N$ is compact). In addition, if $N$ is Hadamard then $M$ has finite topology. We also show that the fundamental tone is an obstruction for a Riemannian manifold to be realized as submanifold with tamed second fundamental form of a Hadamard manifold with sectional curvature bounded below.
Eigenvalue Estimates for submanifolds of $N \times \mathbb{R}$ with locally bounded mean curvature
G. Pacelli Bessa,M. Silvana Costa
Mathematics , 2008, DOI: 10.1090/S0002-9939-08-09680-9
Abstract: We give lower bounds for the fundamental tone of open sets in submanifolds with locally bounded mean curvature in $ N \times \mathbb{R}$, where $N$ is an $n$-dimensional complete Riemannian manifold with radial sectional curvature $K_{N} \leq \kappa$. When the immersion is minimal our estimates are sharp. We also show that cylindrically bounded minimal surfaces has positive fundamental tone.
Existence and nonexistence of least energy solutions of the Neumann problem for a semilinear elliptic equation with critical Sobolev exponent and a critical lower-order perturbation
David G. Costa,Pedro M. Gir?o
Mathematics , 2014, DOI: 10.1016/S0022-0396(02)00070-0
Abstract: Let $\Omega$ be a smooth bounded domain in $\mathbb{R}^{N}$, with $N\geq 5$, $a>0$, $\alpha\geq 0$ and $2^*=\frac{2N}{N-2}$. We show that the the exponent $q=\frac{2(N-1)}{N-2}$ plays a critical role regarding the existence of least energy (or ground state) solutions of the Neumann problem $$ \left\{\begin{array}{ll} -\Delta u+au=u^{2^*-1}-\alpha u^{q-1}&\mbox{in}\ \Omega,\\ u>0&\mbox{in}\ \Omega,\\ \frac{\partial u}{\partial\nu}=0&\mbox{on}\ \partial\Omega. \end{array}\right. $$ Namely, we prove that when $q=\frac{2(N-1)}{N-2}$ there exists an $\alpha_{0}>0$ such that the problem has a least energy solution if $\alpha<\alpha_{0}$ and has no least energy solution if $\alpha>\alpha_{0}$.
On cylindrically bounded $H$-Hypersurfaces of $\mathbb{H}^{n}\times \mathbb{R}$
G. Pacelli Bessa,Silvana M. Costa
Mathematics , 2006, DOI: 10.1016/j.difgeo.2007.11.024
Abstract: We show that $H$-hypersurfaces of $\mathbb{H}^{n}\times \mathbb{R}$ contained in a vertical cylinder and with Ricci curvature with strong quadratic decay have mean curvature $| H| > (n-1)/n$.
Metodologia SIG para a avalia o da contamina o de solos em ambiente urbano-industrial
M. G. Brito,C. N. Costa,G. Avillez,M. Lopes
Finisterra - Revista Portuguesa de Geografia , 2003,
Abstract: ENVIRONMENTAL IMPACT ASSESSMENT USING GIS AT URBAN INDUSTRIAL SITES. The aim of this paper is to present a practical experience that uses GIS methodology for environmental impact assessment on industrial activity in Portugal. A conceptual environmental model was used to evaluate and rank areas of risk, taking into account the source of contamination (industrial sites), the biophysical receptors (contamination transmitter) and the anthropological receptors (target). Due to lack of information related to industrial sites, it was necessary to define simple environmental criteria to be used as a primary environmental guide for further investigation phases.Each site (source) is characterized by environmental criteria and categorized by an index that summarises potential contamination impact as a pollutant source. Identically, biophysical media and anthropological receptors are classified and categorized by index values to account for the susceptibility of the receptors.In order to identify priority investigation sites, a GIS model (Arcview 3.2) was developed that integrates environmental parameters in two stages: 1st stage – corresponds to the individual evaluation of each environmental attribute (sources, biophysical receptor and anthropological receptors) by the weighted integration of respective criteria. Output results give the environmental status on (i) site potential contamination, (ii) site biophysical susceptibility and (iii) evaluation of local risk, if contamination occurs.2nd stage – corresponds to the evaluation of priority risk areas by the integration and weighting of the individual 1st stage results. Depending on weighting factors, each output is a scenario of the site environmental status, where the highest index values indicate sites where further investigation is a priority. The final result is a diagnosis environmental map, which is the decision basis for future site investigation and remediation development. This methodology was applied to the first case study in Portugal - Seixal Municipality, a suburban of Lisbon and one of the most industrialized and polluted areas
Volatiliza??o de N-NH3 de fontes nitrogenadas em cana-de-a?úcar colhida sem despalha a fogo
Costa, M. C. G.;Vitti, G. C.;Cantarella, H.;
Revista Brasileira de Ciência do Solo , 2003, DOI: 10.1590/S0100-06832003000400007
Abstract: where sugarcane is harvested without burning, a thick layer of straw remains on the soil. this crop residue modifies the agroecosystem and requires a reformulation of the crop management. urea is the most common nitrogen source for sugarcane but, when applied on top of the crop residue, nh3-nloss rates are high. this work was carried out under field conditions in the sugarcane production region of piracicaba, state of s?o paulo, brazil, on an arenic kanhaplodult, using the third rattoon of the variety sp 80-1842, harvested mechanically without previous burning. the objective of this study was to evaluate the agronomic efficiency of nitrogen sources applied over sugarcane trash by the determination of nh3-n losses by volatilization, crop yield and quality. the nitrogen rate was 100 kg ha-1. the experimental design was in completely randomized blocks with five replications and five treatments: t0- control, t1- urea, t2- uran, t3- urea + ammonium sulfate, t4-liquid residue enriched with n. static semi-open nh3 collectors were used to evaluate losses by ammonia volatilization. the results showed that nh3-n losses were higher in t1 and t3 (36 and 35 %, respectively), and lower in t2 and t4 (15 and 9 %, respectively). sugarcane yields were affected by the nitrogen fertilization as well as by volatilization losses.
Page 1 /540278
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.