Showing papers by "State University of Campinas published in 1989"
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24 Feb 1989TL;DR: In this paper, the authors introduce linear dynamical systems, nonlinear systems, and Chaotic systems for quantum field theory, and Torus quantization of ergodic systems.
Abstract: Preface 1. Linear dynamical systems 2. Nonlinear systems 3. Chaotic systems 4. Normal forms 5. Maps of the circle 6. Integrable and quasi-integrable systems 7. Torus quantization 8. Quantization of ergodic systems 9. Periodic orbits in quantum field theory References Index.
388 citations
TL;DR: In this paper, a necessary and sufficient condition for linear quadratic stabilization of linear uncertain systems when both the dynamic as well as the control matrix are subject to uncertainty is given. And a constructive numerical procedure is defined to check the condition and furthermore provides a stabilizing linear feedback gain.
331 citations
TL;DR: The method was used to survey 296 samples that included 10 cultivars of dried beans, 8 types of corn products, 3 types of cassava flour, and both polished and parboiled rice between May 1985 and June 1986 in Campinas, Brazil and proved appropriate for simultaneous determination of aflatoxins, ochratoxin A, sterigmatocystin, and zearalenone, with considerable savings in time and reagent costs.
Abstract: A previously published method for ochratoxin A was evaluated and proved appropriate for simultaneous determination of aflatoxins, ochratoxin A, sterigmatocystin, and zearalenone, with considerable savings in time and reagent costs The detection limits were 2, 5, 15, and 55 micrograms/kg, respectively The recoveries and coefficients of variation obtained with artificially contaminated samples were 91-101% and 0-16% for aflatoxin B1, 98-117% and 0-17% for sterigmatocystin, and 96-107% and 0-17% for zearalenone, respectively The coefficients of variation for naturally contaminated samples (aflatoxins in rice and ochratoxin A in beans) ranged from 0 to 8% The method was used to survey 296 samples that included 10 cultivars of dried beans, 8 types of corn products, 3 types of cassava flour, and both polished and parboiled rice between May 1985 and June 1986 in Campinas, Brazil Only aflatoxin B1 (9 samples, 20-52 micrograms/kg), aflatoxin G1 (4 samples, 18-31 micrograms/kg), and ochratoxin A (5 samples, 32-160 micrograms/kg) were found The average contamination percentage was 47%; beans showed the highest (66%) and rice showed the lowest (33%) incidence rates Zearalenone and sterigmatocystin were not detected Positive samples were confirmed by chemical derivatization, corroborated by development in 3 solvent systems
240 citations
TL;DR: In this article, a heuristic search strategy with practical rules (e.g. depth-first search) armed with operator experience is proposed to guide the search of service restoration, service reconfiguration and other related problems.
Abstract: Service restoration, service reconfiguration, and other related problems are formulated and solved by heuristic search, which is a search strategy (e.g. depth-first search) armed with practical rules (e.g. based on operator experience) to guide the search. The method is based on operator procedures and usually generates the same solutions as operators would do. However, it is also possible to investigate alternatives that normally would not be considered by system operators, which can be very helpful under certain critical operating conditions. Moreover, the proposed framework makes it possible to investigate the effect of practical rules on the optimality of the final solution and so can be a useful tool in designing new algorithms. Test results are presented, and an illustrative example is given. The preliminary results indicate that the proposed technique is very promising. >
203 citations
TL;DR: In this article, the vegetational and environmental variations within a cerrado in southern Mato Grosso state (150 21' S, 550 49' W) were described by means of field classification, direct gradient analysis and reciprocal averaging ordination.
Abstract: Cerrado is a species-rich savanna-like vegetation that covers a large area in central Brazil. Soil, and particularly soil fertility, is considered to be the major factor determining the wide and diverse physiognomic-floristic gradients encountered within cerrado vegetation. To describe the vegetational variations within a cerrado in southern Mato Grosso state (150 21' S, 550 49' W), a 1 ha transect was located to pass through an interfluvial cerrado and climb a steep talus slope. The vegetational and environmental variations are described by means of field classification, direct gradient analysis and reciprocal averaging ordination. The effects of dif- ferences in ground water regime in the interfluvial cerrado and differences in inclination with associated rockiness in the talus cerrado are related to the vegetational variations. As the soils are very similar in texture and in the majority of chemical properties, the role of the above environmental factors was more easily distinguished. In the interfluvial cerrado, the vegetation variations are probably related to the seasonal fluctuation in water table level.
137 citations
TL;DR: Oligonucleotide primers were used to amplify specific DNA regions of the Bordetella pertussis genome by the polymerase chain reaction and were able to discriminate between the pathogen and related Bordetlla species.
130 citations
TL;DR: In this article, the authors investigated the 5-year survival rate in both groups; a secondary aim was to analyze the local recurrence rate and finally the anatomopathologic tumoral classification after surgery.
Abstract: From 1978 to 1980, 68 patients with rectal cancer were randomly allocated to either preoperative irradiation plus surgery or surgical treatment without any preoperative measures. The primary aim of the trial was to investigate the 5-year survival rate in both groups; a secondary aim was to analyze the local recurrence rate and finally the anatomopathologic tumoral classification after surgery. All patients were followed at least 8 years. The preoperative irradiation group (Group A) was submitted to 4000 cGy for 4 weeks and surgery was performed 1 week after irradiation. All tumors were classified anatomically and pathologically according to Broders' and Dukes' classifications. The results indicated that there is a significant difference in the five-year survival rates in both groups: group A had a corrected survival rate of 80 percent; group B (nonirradiated) had a corrected survival rate of 34.4 percent. The local recurrence rate was 2.9 percent in group A and 23.5 percent in group B. Regarding tumor regression, before radiotherapy 64.6 percent of the tumors were Broders' Grades 3 and 4; after radiotherapy these were reduced to 20.5 percent. As to Dukes' classification, 26.4 percent of the tumors were type C in group A and, in group B, 47 percent were considered as Dukes' C.
110 citations
101 citations
TL;DR: In this paper, preliminary studies of voltage vs speed relationships, stability of generated voltage, and voltage compensation of the self-excited induction generator are presented, and the long-shunt connection of the capacitors to the generator is used.
Abstract: Preliminary studies of voltage vs. speed relationships, stability of generated voltage, and voltage compensation of the self-excited induction generator are presented. In order to improve the voltage regulation, the long-shunt connection of the capacitors to the generator is used. The magnetizing inductance of the machine is used as a saturable reactor. The values of the capacitors for series and parallel connections are obtained from the saturation characteristics of the machine. Experimental results are reported. The maximum voltage drop is about 4%. >
82 citations
TL;DR: The many-flowered, brush-like spikes of Encholirium glaziovii, a ground-dwelling pitcairnioid bromeliad of the “campo rupestre” formation of southeastern Brazil, was observed being pollinated by the glossophagine bat,Lonchophylla bokermanni, in the Serra do Cipó (Minas Gerais).
Abstract: The many-flowered, brush-like spikes ofEncholirium glaziovii, a ground-dwelling pitcairnioid bromeliad of the “campo rupestre” formation of southeastern Brazil, was observed being pollinated by the glossophagine bat,Lonchophylla bokermanni, in the Serra do Cipo (Minas Gerais). Nectar feeding was while hovering, and the pollen was preferentially transferred by the bat's snout. The floral pattern is chiropterophilous; unlike known tillandsioid bat flowers, stamens and style are protrusive beyond a small, persistent perigon, and anthesis, apparently protogynous, extends over several nights, with gradual onset and cease. Although various other flower-visitingChiroptera are known to occur in the area and are not mechanically precluded from exploitingEncholirium glaziovii, no one seems to compete withLonchophylla bokermanni. This species, a trap-liner, habitually forages in open habitats, a possible reason for its exclusiveness.—Flower details of two other species ofEncholirium from the same locality including one with the bat pollination syndrome, are given.
81 citations
TL;DR: The electropolymerization reaction of pyrrole in the presence of sodium dodecyl sulphate has been studied and the electroactivity of the polymer investigated with respect to parameters such as the ionic nature of the electrolyte as discussed by the authors.
TL;DR: The photoacoustic signal of a narrow-gap semiconductor and of Si is investigated as a function of the modulation frequency through the use of a heat-transmission configuration and from the signal phase data the values of the surface recombination velocity and the nonradiative band-to-band recombination time are obtained.
Abstract: The photoacoustic signal of a narrow-gap semiconductor and of Si is investigated as a function of the modulation frequency through the use of a heat-transmission configuration. It is shown that in the thermally thick modulation-frequency range the signal amplitude can single out the different heating sources responsible for the photoacoustic signal. It is also shown that from the signal phase data, as a function of the modulation frequency, we can obtain the values of the surface recombination velocity and the nonradiative band-to-band recombination time.
TL;DR: In this article, the x-ray radiation emitted by a charged particle as it penetrates a perfect crystal is studied, and it is shown that in addition to the already known C\ifmmode \check{}\else \v{}\fi{}erenkov radiation peak, there is a second peak due to dynamical diffraction of the electromagnetic field associated with the electron.
Abstract: The x-ray radiation emitted by a charged particle as it penetrates a perfect crystal is studied. We find that in addition to the already known C\ifmmode \check{}\else \v{}\fi{}erenkov radiation peak, there is a second peak which is due to the dynamical diffraction of the electromagnetic field associated with the electron. The theory developed here, which is an extension of the dynamical theory of x-ray diffraction, allows us to treat situations in which the direction of incidence of the electron, as well as the orientation of the crystal surface relative to the crystal planes, are kept arbitrary. Our equations apply also to situations in which the Bragg angle is close to \ensuremath{\pi}/2, where several of the approximations usually made in the dynamical theory are known to fail. Various features such as intensities, direction, frequency, and the spectral and angular widths of both the C\ifmmode \check{}\else \v{}\fi{}erenkov and the ``transition-diffracted'' radiation are studied. A geometrical construction of the dispersion surfaces has been found to be very useful in visualizing the content of the theory. It is possible that these two processes of emission may find application as a tunable source of monochromatic and very directional x rays.
TL;DR: In this article, the age data for the Angadimogar syenite (AM) and the Peralimala alkali granite (PM), belonging to this suite, define isochron ages of 638 ± 28 and 750 ± 40 Ma, respectively, with initial 87 Sr 86 Sr ratios of 0.7032 ± 0.0008, respectively.
TL;DR: Results show that these mitochondria are able to build up and retain a membrane potential as indicated by a tetraphenylphosphonium-sensitive electrode, and large amounts of Ca2+ were retained by T. cruzi mitochondria even after addition of thiols and NAD(P)H oxidants.
01 Feb 1989
TL;DR: It is suggested that some showy, eglandular species such as Banisteriopsis lutea may act as general mimics of other, oil-rewarding Malpighiaceae species.
Abstract: The visiting behaviour of oil-gathering, anthophorid bees on eglandular morphs of two Malpighiaceae species was observed in southeastern Brazil. The bees landed on eglandular flowers apparently by mistake, as suggested by their making one to a few scraping movements on landing, and behaving in the same way as they scrape oil glands on glandular flowers. After perceiving their mistake the bees either left the flower, making one to a few additional visits to other eglandular flowers before leaving the plant, or switched to pollen collecting. Large and medium-sized species of Centris, and some Epicharis, left the flowers after mistake visits, thus wasting time and energy, whereas small Centris and larger Epicharis switched to pollen harvesting, thus turning a mistake into a rewarding visit. Eglandular flowers of both Banisteriopsis muricata and Heteropterys aceroides attracted oil-gathering bees by deceit and probably acted as mimics of glandular flowers of their own species (automimicry). The pollination of eglandular morphs of these two Malpighiaceae species seems dependent mainly on the opportunistic, mixed oil-pollen gathering behaviour of deceived bees such as Epicharis schrottkyi. We suggest that some showy, eglandular species such as Banisteriopsis lutea may act as general mimics of other, oil-rewarding Malpighiaceae species.
TL;DR: De larvas e pupas de Musca domestica, Chrysomya albiceps, Cochliomyia homivorax, Stomoxys calcitrans e Syntesiomyia nudiseta coletadas em diversos ambiente, foram obtidas dez especies de microhimenopteros parasitoides da supermamilia Chalcidoidea.
Abstract: De larvas e pupas de Musca domestica, Chrysomya albiceps, Cochliomyia homivorax, Stomoxys calcitrans e Syntesiomyia nudiseta coletadas em diversos ambiente, em Sao Paulo, Parana, Mato Grosso, Mato Grosso do Sul e Minas Gerais, foram obtidas dez especies de microhimenopteros parasitoides da supermamilia Chalcidoidea, algumas assinaladas pela primeira vez no Brasil.
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TL;DR: In this article, it was shown that all inertial forces are due to gravitational interaction with other bodies in the universe, and that the resultant force acting on any body is zero.
Abstract: We propose the postulate that the resultant force acting on any body is zero. With this postulate and with a Weber force law for gravitation, we obtain equations of motion and conclude that all inertial forces are due to gravitational interaction with other bodies in the universe, as suggested by Mach. We then obtain the same value for the advance of the perhelion of the planets as is given by general relativity. All this is accomplished in a strictly relational theory. Finally, we relate these points to topical questions of electrodynamics raised by the experimental studies of Graneau and Pappas.
TL;DR: In this paper, the use of Landsat Thematic Mapper (TM) imagery for geological mapping in a tectonically-complex area of south-east Spain is described, which includes the metamorphic basement rocks of the Betic Cordillera and the sedimentary strata of an intermontane basin.
Abstract: Abstract This paper describes the use of Landsat Thematic Mapper (TM) imagery for geological mapping in a tectonically-complex area of south-east Spain The terrain includes the metamorphic basement rocks of the Betic Cordillera and the sedimentary strata of an intermontane basin TM bands 1, 3 and 5 were used to produce a colour composite Experimentation showed that this was the most effective band combination to discriminate rock types in the semi-arid study region A combination of spectral and textural characteristics was used to identify and map rock types in the Nevado-Filabride and Alpujarride basement complexes, sedimentary strata in the Neogene Tabernas-Sorbas Basin and Quaternary drift deposits Structural features were best shown by digital convolution using a directional filter The enhanced images revealed a previously unreported fault and fracture belt on the northern side of the Tabernas Basin The geological interpretation of enhanced TM imagery was locally checked in the field
TL;DR: In this article, a new approach to determine the Chemical Oxygen Demand (COD) using a microwave digestion to replace the conventional time consuming reflux method is proposed, which uses a microwave oven for the digestion of small volumes of sample (from 500 up to 2000 μ1), in a completely closed 60 ml Teflon vessel.
TL;DR: In this article, a simple open photoacoustic cell method is demonstrated for obtaining the thermal diffusivity of alloys, based upon the measurement of the acoustic signal as a function of the modulation frequency in the region where the sample is thermally thick.
Abstract: A simple open photoacoustic cell method is demonstrated for obtaining the thermal diffusivity of ${\mathrm{Pb}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$${\mathrm{Sn}}_{\mathrm{x}}$Te alloys. It is based upon the measurement of the acoustic signal as a function of the modulation frequency in the region where the sample is thermally thick. The dependence of the measured values of the thermal diffusivity as a function of the alloy composition is also discussed.
TL;DR: A pesquisa foi desenvolvida de abril de 1987 a novembro de 1988, e foram coletadas e identificadas 415 especies, sendo 362 dicotiledoneas, pertencentes a 84 familias e 224 generos, and 53 monocotiledonesas.
Abstract: Foi desenvolvido um estudo floristico no Parque Municipal da Grota Funda, municipio de Atibaia, estado de Sao Paulo (46o25'W e 23o10'S), uma regiao montanhosa situada entre 900 e 1 400m de altitude. O clima e caracterizado por duas estacoes: uma quente e umida, de outubro a marco, e uma seca e fria, de abril a agosto, com ocorrencia comum de geadas. O solo arenoso apresenta baixa fertilidade, e elevada acidez superficial. A pesquisa foi desenvolvida de abril de 1987 a novembro de 1988, e foram coletadas e identificadas 415 especies, sendo 362 dicotiledoneas, pertencentes a 84 familias e 224 generos, e 53 monocotiledoneas, pertencentes a 15 familias e 43 generos. A riqueza especifica observada em Atibaia pode ser atribuida a diversidade de ambientes, a variacao edafica e a baixa perturbacao observada na vegetacao. Foi feita uma comparacao com outros estudos floristicos em matas de altitude, sendo apresentada uma lista das especies mais comuns nessas matas.
TL;DR: O projeto foram estudados todos os partos hospitalares no municipio de Ribeirao Preto, Brasil no periodo de l de junho de 1978 a 31 de maio of 1979, e o estudo foi feito atraves de entrevistas com todas as puerperas que deram o luz.
Abstract: Os autores apresentam a metodologia do planejamento, montagem, execucao empirica e um prototipo de analise de pesquisa em saude perinatal. No projeto foram estudados todos os partos hospitalares (resultando recem-nascidos vivos) no municipio de Ribeirao Preto, Brasil, no periodo de l de junho de 1978 a 31 de maio de 1979. O estudo foi feito atraves de entrevistas com todas as puerperas que deram o luz nos 8 hospitas-maternidades do municipio, e as informacoes obtidas referiam-se aos pais, a renda, a gestacao e ao parto, incluindo a atencao medica ao recem-nascido, ao obito da crianca (quando ocorresse), a etnia e a reproducao humana. Sao apresentados em detalhes, os passos para a execucao do projeto, bem como a conceituacao da classe social e sua operacionalizacao, ponto basico para o modelo de analise.
TL;DR: In this article, the authors examine the status of various forms of PII in both classical and quantum physics and conclude that this latter view is at best doubtful, at worst, simply wrong.
Abstract: Faced with strong arguments to the effect that Leibniz'sPrinciple of the Identity of Indiscernibles (PII) is not a necessary truth, many supporters of the Principle have staged a strategic retreat to the claim that it is contingently true in this, the actual, world The purpose of this paper is to examine the status of the various forms of PII in both classical and quantum physics, and it is concluded that this latter view is at best doubtful, at worst, simply wrong
TL;DR: Dans le spectre theorique en observe une limite d'absorption associee aux transitions impliquant des impuretes au centre du puits, and un pic relie aux impurtes aux limites du puit.
Abstract: The optical-absorption spectra associated with transitions between the n=1 valence subband and the donor-impurity band and between the acceptor-impurity band and the n=1 conduction subband were calculated for both the infinite and the finite GaAs-${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$${\mathrm{Al}}_{\mathrm{x}}$As quantum wells. An absorption edge associated with transitions involving impurities at the center of the well and a peak related with impurities at the edges of the well were the main features observed in the theoretical spectra. Results obtained in the case of an infinite quantum well were rather different from those previously reported in the literature.
TL;DR: No change in any of the hormones studied was observed, with the exception of a significant increase in progesterone 2 months after tubal ligation by the Uchida technique.
TL;DR: Sao apresentado dois casos de paracoccidioidomicose, one em paciente com a sindrome da imunodeficiencia adquirida e o outro em infeccao pelo HIV Trata-se dos primeiros relatos em que esta associacao e descrita na literatura as mentioned in this paper.
Abstract: Sao apresentados dois casos de paracoccidioidomicose, um em paciente com a sindrome da imunodeficiencia adquirida e o outro em paciente com infeccao pelo HIV Trata-se dos primeiros relatos em que esta associacao e descrita na literatura No primeiro, a micose se evidenciou durante o acompanhamento de paciente com AIDS, que passou a apresentar hepato-esplenomegalia e febre elevada A ecografia, radiografia simples e tomografia computadorizada do abdomen, demonstraram nodulos solidos, alguns calcificados, no parenquima esplenico A puncao aspirativa da medula ossea confirmou o diagnostico; o conjunto dos achados caracterizou a forma aguda disseminada da paracoccidioidomicose, a qual levou o paciente ao obito No segundo relato, em paciente com infeccao pelo HIV, a proposito de investigacao de tumoracao na regiao inguinal e fossa iliaca a direita, constatou-se a associacao de doenca de Hodgkin, tipo celularidade mista e paracoccidioidomicose Avalia-se a importância destes relatos frente a expansao da infeccao pelo HIV e estima-se que mais casos venham a ser relatados em pacientes com AIDS, procedentes de areas endemicas desta micose Propoe-se a inclusao da paracoccidioidomicose como infeccao oportunistica potencial em pacientes HIV positivos nestas areas
01 Jun 1989
TL;DR: In this article, the authors give a definitive treatment to the clocks problem showing that Sachs' "convincing mathematical arguments" are non sequitur and that his later view of the twin paradox coincides with the one derived from the rigorous theory of time developed in this paper.
Abstract: The purpose of the present paper is to reply to a misleading paper by M. Sachs entitled “Einstein's later view of the Twin Paradox” (TP) (Found. Phys.15, 977 (1985)). There, by selecting some passages from Einstein's papers, he tried to convince the reader that Einstein changed his mind regarding the asymmetric aging of the twins on different motions. Also Sachs insinuates that he presented several years ago “convincing mathematical arguments” proving that the theory of relativity does not predict asymmetrical aging in the TP. Here we give a definitive treatment to the clocks problem showing that Sachs' “convincing mathematical arguments” are non sequitur. Also, by properly quoting Einstein, we show that his later view of the TP coincides with the one derived from the rigorous theory of time developed in this paper.
TL;DR: In this paper, a static network synthesis method for transmission expansion planning is presented, which considers as the objective function the most productive trade-off, i.e., the one resulting in low investment costs and good electrical performance.
Abstract: A static network synthesis method for transmission expansion planning is presented. The static synthesis problem is formulated as a mixed-integer network flow model that is solved by an implicit enumeration algorithm. This model considers as the objective function the most productive trade-off, i.e. the one resulting in low investment costs and good electrical performance. The load and generation nodal equations are considered in the constraints of the model. The power transmission law of DC load flow is implicit in the optimization model. Results of computational tests are presented, showing the advantage of this method compared with a heuristic procedure. The case studies provide a comparison of computation times and costs of solutions obtained for the Brazilian North-Northeast transmission system. >