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251. Micro-force measurement with pre-curvature long-period fiber grating-based sensor

Author

Ferreira Walter S. J., dos Santos Paulo S. S., Caldas Paulo, Jorge Pedro A. S., and Sakamoto João M. S.

Subjects
Physics, QC1-999
Abstract

In this work, a long-period fiber grating (LPG) based sensor was evaluated as a sensing device for micro-force measurement, in the order of micro Newtons. It was used an LPG fabricated by arc-inducted technique in a SMF-28 standard optical fiber. The optical fiber was fixed between two clamps with a separation of 150 mm with the middle of the LPG located at the center. Characterizations were performed in terms of temperature, curvature and strain. The grating was then used as a micro-force sensor by means of both curvature and strain, induced by a hung mass in a stretched fiber. Furthermore, the evaluation of a precurvature LPG was performed to assess if an increase of sensitivity is achieved. Micro-force sensitivity achieved with the stretched LPG was 1.41 nm/mN and it was demonstrated that its sensitivity can be enhanced to 5.14 nm/mN with a pre-curvature of 2.2 m–1 applied to the LPG, achieving a spectral resolution of at least 15.6 μN.

Published
2020
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252. TIME-SEGMENTED FREQUENCY-DOMAIN ANALYSIS FOR NON-LINEAR MULTI-DEGREE-OF-FREEDOM STRUCTURAL SYSTEMS

Author

MANSUR, W. J., CARRER, J. A. M., FERREIRA, W. G., CLARET DE GOUVEIA, A. M., and VENANCIO-FILHO, F.

Abstract

This paper presents a new frequency-domain method to analyze physically non-linear structural systems having non-proportional damping. Single- and multi-degree-of-freedom (d.o.f.) systems subjected to time-dependent excitations are considered. A procedure to consider initial conditions, required by the methodology described, is discussed. The algorithm described here employs a time-segmented procedure in modal co-ordinates in the frequency domain; solution in each time-segment being obtained by an iterative process. The proposed methodology is validated by three examples. The procedure presented here can be employed as well to analyze structural systems with viscous and hysteretic damping or else with frequency-dependent damping properties.

Published
2000
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256. Effects of the Bi3+ substitution on the structural, vibrational, and magnetic properties of bismuth layer-structured ferroelectrics.

Author

Silva, P. H. T., Silva, M. A. S., da Silva, R. B., Correa, M. A., Bohn, F., de Menezes, A. S., Ferreira, W. C., Ayala, A. P., Sombra, A. S. B., and Fechine, P. B. A.

Subjects
MAGNETIC properties, CURIE-Weiss law, BISMUTH, MAGNETIC susceptibility, MOSSBAUER spectroscopy, FERROELECTRIC ceramics, HIGH temperatures
Abstract

Bismuth layer-structured ferroelectric Bi3R2Ti3FeO15 (R = Bi, Nd, and Gd) ceramics were synthesized by conventional solid-state reaction. All the samples showed an orthorhombic structure with A21am space group. Bi3Nd2Ti3FeO15 and Bi3Gd2Ti3FeO15 presented a reduction in the orthorhombicity when compared to Bi5Ti3FeO15. The magnetic susceptibility of all samples followed the Curie–Weiss law, with negative values of the Curie–Weiss temperature, demonstrating that the magnetic interactions are antiferromagnetic in nature. The magnetization curves suggested a weak canted antiferromagnetic behavior for temperatures below 25 K, followed by a linear behavior in the curves at high temperatures. Mössbauer spectroscopy measurements revealed an increase of the quadrupole splitting values as the temperature decreases, indicating that the samples present local distortions, favoring the existence of weak ferromagnetic phase via the antisymmetric Dzyaloshinskii–Moriya interaction. [ABSTRACT FROM AUTHOR]

Published
2020
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258. Cinética da sorção de fósforo em solos dos trópicos úmidos da Amazônia

Author

SINGH, R., MOLLER, M. R. F., FERREIRA, W. de A., RAMENDRA SINGH, IICA-EMBRAPA, MARIA REGINA FREIRE MOLLER, CPATU, and WALDEMAR DE ALMEIDA FERREIRA, CPATU.

Subjects
Solo, Amazonia, Fósforo
Abstract

Made available in DSpace on 2021-04-14T17:34:23Z (GMT). No. of bitstreams: 1 Cinetica-da-sorcao.pdf: 2831811 bytes, checksum: 348fba071b9f5ea7787684d1a7525734 (MD5) Previous issue date: 1983

Published
1983

259. Características da sorção do fósforo relacionadas com propriedades selecionadas de solos dos trópicos úmidos da Amazônia

Author

SINGH, R., MOLLER, M. R. F., FERREIRA, W. de A., RAMENDRA SINGH, IICA-EMBRAPA, MARIA REGINA FREIRE MOLLER, CPATU, and WALDEMAR DE ALMEIDA FERREIRA, CPATU.

Subjects
Solo, Amazonia, Fósforo
Abstract

Made available in DSpace on 2021-04-14T17:34:43Z (GMT). No. of bitstreams: 1 Caracteristicas-sorcao-do-fosforo.pdf: 6630990 bytes, checksum: 7964a40edfc9d02ffa270dea7f5d7e4d (MD5) Previous issue date: 1983

Published
1983

260. Consequences of immunization against GnRF and ractopamine supplementation on behavioral traits of heavy weight market gilts.

Author

Rodrigues, L. A., Prezotti, G. P., Ferreira, F. N., Spricigo, L., Reis, L. G., Junior, D. M., Silva, F. C., Ferreira, W. M., and Fontes, D. O.

Subjects
SOWS, RACTOPAMINE, LUTEINIZING hormone releasing hormone, ANIMAL behavior
Abstract

Immunocastration (IM) has recently emerged as an alternative for rearing gilts up to heavier slaughter weights, considering its effects on performance improvement and sexual behavior suppression. The interaction between IM and ractopamine (RAC) supplementation is reported to be beneficial for growth and carcass characteristics. However, some studies reported RAC's adverse effects on swine behavior, mainly increased aggressiveness. Seventy-two gilts (2 gilts/pen) were used in order to measure the interactive effects between IM and RAC on behavioral characteristics and on human-pig interaction during the finishing phase. The factorial arrangement was defined as 2 RAC levels (0 and 10 mg/kg of diet) by 2 immunization categories (nonimmunized and immunized gilts). The first and second immunizations were performed at 15 and 19 wk of age, respectively. Ractopamine supplementation occurred from 21 to 25 wk of age, when all the gilts were exposed to mature boars daily. Animal behavior (on a 24-h basis) and the interaction between gilts and an observer positioned inside a test pen were both evaluated at a single time point (at 23 wk of age). There were no treatment effects on time spent eating, drinking, lying, fighting, or mounting (P > 0.05) during the 24-h period. Both RAC (-21.6%; P < 0.05) and IM (-32.3%; P < 0.01) caused a reduction in standing behavior and there was an interaction between IM and time for sitting behavior (P < 0.01), where immunized gilts concentrated this behavior from 1600 to 2000 h (2.11%), with a peak at 1800 h (3.89%). Aiming to assess effects of IM and RAC on human-pig interaction, groups of 4 gilts within each treatment were exposed to an observer standing in the corner of a test pen. Immunized gilts both crossed a line 1 m distant from the observer (-67.38 s; P < 0.001) and approached the observer (-125.47 s; P < 0.001) in a reduced time compared with nonimmunized gilts, regardless of RAC. The type of interaction between animals and the observer was graded from 1 to 5 (1 = soft contact with the observer and 5 = pigs aggressively tweaking on the observer's clothes) and was not affected by treatments (P > 0.05). Immunocastration and RAC did not entail any aggressive behavior on late finishing gilts, and IM improved their willingness to approach and investigate. Assessment of comportment traits in a larger number of animals, under commercial conditions, merits further investigation. [ABSTRACT FROM AUTHOR]

Published
2017
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261. Origin and progress of the 1968-69 Hong Kong influenza epidemic1

Author

Cockburn, W. Charles, Delon, P. J., and Ferreira, W.

Subjects
Influenza, Human, Humans, Session I—Epidemiology of Hong Kong Influenza, Epidemiologic Methods, World Health Organization, Disease Outbreaks
Abstract

The Hong Kong strain of influenza virus A2 may have originated in the mainland of China but this is not certain. It caused a very large epidemic in Hong Kong and spread rapidly to countries as far as India and the Northern Territory of Australia-as happened in the 1957 epidemic. Later its progress slowed down but epidemics occurred in many countries in the northern hemisphere in the winter of 1968-69. In all these countries except the United States of America the disease was mild and not associated with a large increase of deaths. In the United States of America, however, the number of "excess deaths" was similar to the number in 1957-58.In the southern hemisphere epidemics began in May-June 1969; they have been clinically mild and the reported incidence of disease has been only moderately high.In many countries the infection has spread slowly and smouldered instead of bursting into the usual sharp epidemics.The smouldering spread and the contrast in the behaviour of the disease in the USA compared with the rest of the world are the outstanding features of the Hong Kong strain of virus. Satisfactory explanations of these observations might lead to the development of more effective means of control of influenza.

Published
1969

262. WHO respiratory disease survey in children: A serological study

Author

Chanock, R., Chambon, L., Chang, W., Ferreira, F. Gonçalves, Gharpure, P., Grant, L., Hatem, J., Imam, I., Kalra, S., Lim, K., Madalengoitia, J., Spence, L., Teng, P., and Ferreira, W.

Subjects
Asia, viruses, Complement Fixation Tests, Age Factors, India, Infant, Articles, South America, Health Surveys, Virus Diseases, Child, Preschool, Africa, Humans, Respiratory Tract Infections
Abstract

This paper is a report on the first (serological) phase of a study organized by WHO in collaboration with the WHO International Reference Centre for Respiratory Virus Diseases other than Influenza in Bethesda, Md., USA, to define the viral etiology of severe respiratory infections in children, particularly in tropical areas. Paired sera from 528 children up to 5 years old admitted to hospital with severe respiratory illness of probable viral etiology were collected in 10 countries and sent frozen to the International Reference Centre, where standard complement-fixation tests were made for the following agents: parainfluenza virus types 1, 2 and 3, influenza virus types A and B, adenoviruses, respiratory syncytial virus, Mycoplasma pneumoniae, Coxiella burneti and psittacosis-ornithosis.Some 41% of paired sera showed rising antibody titres for one or more of these agents, multiple infections being observed in 8%. In most of the countries the pattern of infection was similar. RS virus was the most important respiratory tract pathogen of early life, particularly in the first year of life and in cases of bronchiolitis and pneumonia; the parainfluenza viruses were next in importance, particularly in cases of croup, but, in contra-distinction to RS virus infections, they were commoner in older children. Influenza, adenoviruses, and M. pneumoniae were of moderate importance, and C. burneti and the psittacosis-ornithosis agents were relatively rare. This pattern is similar to that which has been observed in temperate climates.

Published
1967

263. An electron microscope study of the regenerating nerve fibers

Author

Estable C, Acosta-Ferreira W, and Sotelo

Subjects
Microscopy, Histology, Chemistry, Electrons, macromolecular substances, Cell Biology, Anatomy, Regenerative process, Pathology and Forensic Medicine, law.invention, Guinea pig, Microscopy, Electron, Nerve Fibers, nervous system, law, Electron microscope
Abstract

Guinea pig sciatic nerves were severed in order to obtain a regenerative process of the nerve fibers. The animals were killed at different periods of time after the severing (24 hours, 6 days and 12 days) and the specimens obtained were prepared for electronmicroscopic study.

Published
1957

276. HIV-2 seroprevalence in Guinea-Bissau

Author

João Piedade, Miguel Viveiros, Costa, C., Santos Pinto, A., Prieto, E., Albuquerque, R., Paulo Silva, A., Dias, F., Mansinho, K., Champalimaud, J., Araújo, C., and Canas Ferreira, W. F.

277. Geodiversity and biodiversity: An integrated analysis as a basis for the sustainable exploitation of the mineral resources of the Albardão Continental Shelf, Pelotas Sedimentary Basin, RS, Brazil,Geodiversidade e biodiversidade: Análise integrada como subsídio à explotação sustentável dos recursos minerais da Plataforma Continental do Albardão, Bacia Sedimentar de Pelotas, RS, Brasil

Author

Mattos, P. H., Tagliani, C. R. A., Pinotti, R. M., Joao Luiz Nicolodi, Calliari, L. J., Gandra, T. B. R., and Ferreira, W. L. S.

280. Antilonomic effects of Brazilian brown seaweed extracts

Author

Domingos, T. F. S., Carvalho, C., Moura, L. D. A., Valeria Laneuville Teixeira, Pereira, R. C., Bianco, É M., Ferreira, W. J., Ramos, C. J. B., Miranda, A. L. P., Melo, P. A., Guimarães, J. A., and Fuly, A. L.

287. Rapid Ecological Assessment of benthic indicators of water quality: A successful capacity-building experience for Brazilian postgraduate students in ecology | Avaliação ecológica rápida de indicadores bentônicos de qualidade de água: Uma experiência de sucesso na formação de pós-graduandos em ecologia no brasil

Author

Callisto, M., Adauto Ribeiro, Santana, V. B., França, J. S., Ligeiro, R., Ferreira, W. R., Silva, D., Castro, D., Tupinambás, T. H., Santana, D., Souza, B., Gonçalves, F., Rodrigues, L., Andrade, C. B., Sales, S. C. M., and Souza, R.

295. Development of a method for evaluating raw materials for use in iron ore sinter in terms of lime assimilation

Author

Ferreira, W., Robert Cromarty, and Villiers, J.

Subjects
sintering, lime assimilation, properties, iron ore
Abstract

Steel is produced in a basic oxygen furnace from hot metal obtained from a blast furnace. A sintered iron ore with good high-temperature properties (strength and permeability) should be used as feed to the blast furnace. The quality of this sintered ore depends on the reactivity of the iron ore used as feed to the sinter plant during the lime assimilation step in the sintering process. The penetration test is the standard method for evaluating the reactivity of iron ore with lime. It is, however, difficult to determine the exact depth of penetration from the standard test. A new test method is proposed that allows automatic evaluation of iron ores in terms of lime assimilation with increasing temperature. A comparison of the coefficients of variation for the new and standard methods for each ore type demonstrates that the results of the new test are more reproducible and more precise than those of the standard method. The test is also less time-consuming and easier to implement.

296. Molecular epidemiology of HIV

Author

Ricardo Parreira, Aida Esteves, Venenno, T., Franco, M., João Piedade, Sousa, J., and Canas-Ferreira, W. F.

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