19 research outputs found

    Computer program for buckling loads of orthotropic laminated stiffened panels subjected to biaxial in-place loads (BUCLASP 2)

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    General-purpose program performs exact instability analyses for structures such as unidirectionally-stiffened, rectangular composite panels. Program was written in FORTRAN IV and COMPASS for CDC-series computers

    Computer program for stresses and buckling of heated composite-stiffened panels and other structures (BUCLASP 3)

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    General-purpose program is intended for thermal stress and instability analyses of structures such as axially-stiffened curved panels. Two types of instability analyses can be effected by program: (1) thermal buckling with temperature variation as specified and (2) buckling due to in-plane biaxial loading

    BUCLAP2: A computer program for instability analysis of laminated long plates subjected to combined inplane loads. User's manual

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    The usage of the computer program BUCLAP2 is described. The program is intended for linear instability analysis of long, rectangular flat and curved laminated plates with arbitrary orientation of orthotropic axes in each layer. The loadings considered are combinations of inplane normal and shear loads. Arbitray elastic boundary conditions are included for the sides of the plate Instructions for use of the program are included along with Input data requirements, output information, and sample problems. For program description, see

    Elastic stability of laminated, flat and curved, long rectangular plates subjected to combined inplane loads

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    A method is presented to predict theoretical buckling loads of long, rectangular flat and curved laminated plates with arbitrary orientation of orthotropic axes each lamina. The plate is subjected to combined inplane normal and shear loads. Arbitrary boundary conditions may be stipulated along the longitudinal sides of the plate. In the absence of inplane shear loads and extensional-shear coupling, the analysis is also applicable to finite length plates. Numerical results are presented for curved laminated composite plates with boundary conditions and subjected to various loadings. These results indicate some of the complexities involved in the numerical solution of the analysis for general laminates. The results also show that the reduced bending stiffness approximation when applied to buckling problems could lead to considerable error in some cases and therefore must be used with caution

    BUCLAP2: A computer program for instability analysis of laminated long plates subjected to combined inplane loads

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    This program description document describes the program structure and the design details of a CDC 6600 FORTRAN 4 digital computer program, BUCLAP2, which uses minimum energy principles to do an elastic stability analysis of curved and flat laminated rectangular long plates subjected to combined inplane normal and shear loads. Given the geometry, the material properties, and slected boundary conditions for the plate element, the program calculates the minimum buckling load for various wave lengths. The two parallel ends of the program calculates the minimum buckling load for various wave lengths. The two parallel ends of the long plate must be simply supported and arbitrary elastic boundary conditions may be imposed along either one or both external longitudinal sides. For guide to program use, se

    Elastic Stability of Biaxially Loaded Longitudinally Stiffened Composite Structures

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    Toxoplasma gondii: Evaluation of an intranasal vaccine using recombinant proteins against brain cyst formation in BALB/c mice

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    The purpose of this work was to evaluate protective activity against brain cyst formation in BALB/c mice intranasally vaccinated with recombinant proteins from Toxoplasma gondii. The recombinant proteins rROP2, rGRA5 and rGRA7 were used in vaccine preparation. Thirty-three female mice were divided into three groups, these animals received two doses by intranasal route at days 0 and 21 as follows; group 1 (G1, n = 11) received 12.5 mu g of each recombinant protein plus 0.5 mu g of cholera toxin, group 2 (G2, n = 11) received phosphate buffer saline (PBS) plus 0.5 mu g of cholera toxin, and group 3 (G3, n = 11) received PBS only. At challenge day (day 33) three animals from each group were euthanatized for IgA measure from intestine. Mice were infected orally with 50 cysts from the VEG strain at day 33. At challenge day the G1 animals had high immunoglobulin A levels, however, they only showed IgG antibody titers against rROP2 and rGRAT Animals from G1 also exhibited strong resistance to cyst formation compared with the control group (G3, P 0.1). These results indicate that intranasal immunization in BALB/c mice with recombinant proteins rROP2, rGRA5 and rGRA7 associated with cholera toxin induced partial protection, when compared with G3, against tissue cyst formation after oral infection with tissue cysts from T gondii. (c) 2007 Elsevier B.V. All rights reserved

    Dynamic of the natural infection by Anaplasma marginale in Holstein cows and calves in the Londrina region, North of Paraná State, Brazil

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    A dinâmica da infecção por Anaplasma marginale em vacas e bezerros da raça Holandesa foi estudada em duas propriedades leiteiras (A e B) com manejos distintos da região Norte do Paraná. Na propriedade A as vacas eram mantidas no sistema “tie-stall” e, os bezerros em bezerreiros coletivos; na propriedade B, as vacas em sistema “free-stall” e os bezerros em gaiolas individuais. A cada 15 dias efetuou-se a contagem de carrapatos e coletas de amostras de sangue das vacas e seus respectivos bezerros. As vacas foram monitoradas dos 45 dias antes até 60 dias após o parto, e seus bezerros, do nascimento até 240 dias de idade. A parasitemia foi determinada em esfregaços sangüíneos corados pelo Giemsa. O sangue total e as amostras de soro obtidas foram submetidos, respectivamente, as técnicas da PCR e cELISA. Nas vacas os níveis de imunoglobulinas diminuíram próximo ao parto, além de apresentarem uma dinâmica de anticorpos diferentes entre as duas propriedades. Na propriedade A os níveis de anticorpos aumentou entre 30 e 60 dias após o parto e na B os anticorpos permaneceram em níveis baixos no período de monitoramento das vacas. Os níveis de anticorpos dos bezerros da propriedade A que não eram altos no dia do nascimento, diminuíram ainda mais até 45 dias pós-parto e voltou a crescer a partir de 60 dias, com pico máximo aos 105 dias. Na propriedade B, onde os bezerros apresentavam níveis mais elevados de anticorpos no primeiro dia de vida, houve uma diminuição mais demorada dos níveis, alcançando o ponto mais baixo aos 75 dias pós-parto e voltou a crescer bem mais tardiamente, aos 165 dias de idade. Pela PCR, detectou-se A. marginale no sangue de bezerros das duas propriedades, a partir dos 45 dias de vida, com a maioria das amostras de sangue positivas entre 105 e 180 dias. As vacas e bezerros de ambas as propriedades foram expostos ao carrapato Boophilus microplus durante grande parte do período de monitoramento e mostraram parasitemia variando de 0 a 1%. A infecção natural dos bezerros pelo A. marginale após o nascimento foi mais dependente dos níveis de anticorpos colostrais absorvidos do que da intensidade da infestação pelo B. microplus. As diferenças de manejo existentes nas duas propriedades influenciaram os níveis de anticorpos das vacas e bezerros e o período de infecção natural dos bezerros.The dynamic of the infection by Anaplasma marginale in Holstein cows and calves was studied in two dairy farms (A and B) in the Londrina region, North of Paraná. In the farm A the cows were maintained in the tie-stall system and, the calves in collective stall; in the farm B, the cows stayed in freestall system and the calves in individual cages. Every 15 days, blood samples were collected from the dams 45 days before parturition until 60 days post partum, and from their calves at birth until 240 days of age. Tick burden counting was also performed on dams and calves twice a month. Percentage of infected erythrocytes was established by Giemsa-stained smears. Blood and sera samples were examined by Polimerase Chain Reaction (PCR) and competitive Enzime-Linked Immunosorbent Assay (cELISA), respectively. In the cows, the anti-A. marginale antibody levels decreased close to the parturition, showing an adverse behavior among the farms. In the farm A the levels of antibodies increased between 30 and 60 days after the parturition and, in farm B the antibodies stayed in low levels during the accompaniment period of the cows. The anti-A. marginale antibody levels of the calves of the farm A, that were not high in the day of the birth, decreased more until 45 days post parturition and it increased again starting from 60 days, with maximum pick to the 105 days. In the farm B, where the calves presented higher levels of antibodies at the birth day, there was a slower decrease of the antibody levels, reaching the lowest point to the 75 days post parturition and it increased again more tardily, to the 165 days of age. The dams and calves in both farms were exposure to cattle tick Boophilus microplus during almost all period of accompaniment and they showed rickettsemia ranging from 0 to 1%. In conclusion, A. marginale infection after birth was more influenced by maternal antibody levels than tick burden; the differences between animals handling influenced the antibody levels of the dams and calves, and during the natural infection period of the calves; tick burden did not influence the rickettsemia in the studied farms

    Toxoplasma gondii: cloning, sequencing, expression, and antigenic characterization of ROP2, GRA5 and GRA7

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    Toxoplasma gondii is an intracellular obligate protozoan, which infects humans and warm-blooded animals. The aim of the present study was to clone the rop2, gra5 and gra7 genes from T. gondii RH strain and to produce recombinant proteins. The rop2, gra5 and gra7 gene fragments produced by polymerase chain reaction were cloned into the pET102/D-TOPO(R) vector which contains thioredoxin and polyhistidine tags at the C-and N-ends, respectively, and is expressed in Escherichia coli BL21(DE-3). The expression fusion proteins were found almost entirely in the insoluble form in the cell lysate. These recombinant proteins were purified with an Ni-NTA column. Concentrations of the recombinant antigens produced in the E. coli BL21-star ranged from 300 to 500 mu g/mL growth media, which was used to immunize rabbits. We observed an identity ranging from 96 to 97% when nucleotide sequences were compared to GenBank database sequences. Immunocharacterization of proteins was made by indirect immunofluorescence assay. These proteins will be used for serodiagnosis and vaccination
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