Showing papers by "State University of Campinas published in 1976"

Light scattering by lithium tantalate at room temperature

Abstract: The room-temperature Raman spectra of LiTa${\mathrm{O}}_{3}$ for all symmetry phonons are investigated. We make a new assignment of the phonons, which agrees with the selection rules of a ${C}_{3}$ symmetry instead of ${C}_{3v}$, contrary to Kaminow and Johnston's previous work. The oblique phonon dispersions are obtained and turn out to be consistent with our phonon assignments. We obtain also the polariton dispersion curve and, from it, the low-frequency dielectric constant.

Optical modes and dielectric properties of ferroelectric orthorhombic KNbO 3

Abstract: Both Raman scattering and infrared reflectivity measurements have been performed to determine the opticmode spectrum of orthorhombic KNbO, at room temperature. Pincipal-axis phonons and oblique phonons were observed with a combination of 90 scattering, back scattering, and forward scattering. Unobserved longitudinal modes and mode couplings were derived from the reflectivity measurements. The ferroelectric modes, namely those rendered highly anisotropic as a result of successive transitions, were identified and their spatial anisotropy determined; strong interference with more isotropic modes was pronounced. Dielectric constants were derived from these measurements and the A, polariton dispersion curve was also measured. The modes were grouped according to the cubic representations from which they are derived and compared with those of BaTiO, : In particular the modes were three time less damped. Of the original soft cubic ferroelectric mode, the component along the remaining soft direction was found at 56 cm ' and not

Germination of Coffee Seeds (Coffea arabica L. cv. Mundo Novo)

Abstract: The life-span of coffee seeds is extended when seeds are stored with high moisture content. Germination in darkness is always higher than in the light. Exogenous gibberellic acid and abscisic acid inhibit germination while kinetin reverses this inhibitory effect. Low levels of endogenous gibberellin- and abscisic acid-like and high levels of cytokinin-like substances favour germination while the opposite combination of regulators delays germination.

Effects of a cold wave on an Amazonian avifauna in the upper Paraguay drainage, Western Mato Grosso, and suggestions on Oscine-Suboscine relationships

Abstract: The avüauna of the forested upper reaches of the Sopotuba River. in the upper Paraguay drainage just south of the Serra dos Parecís, proved a rnixture of central-Amazonian birds from just east of the Madeira Rtver and of birds of dry forests (Xingú-Tapajóz) or lower Andean forests peripheral to the southern Amazonian region . A cold wave that passed during the study period caused a major drop in insect activity and in the activity of inseci-eating birds and hummingbirds. Fruit-eating birds and "omnivores" (insect and fruit eaters) became relatively conspicuC'Ius. It is suggested that occasio· nal "clisasters" of the type of a cold wave inhibit specialized insectivores at this and other margins of Amazonian forests, and encourage hJgher percentages of omnivores . The previously noted tendency for oscines to replace suboscines at various types of neotropical forest rnargins ls reinterpreted as prlmarily due to declines of furnarioid suboscines (mostly forest-livmg insectivores> and their replacement by omnivf)rous tyrannoid suboscines anel by omnivorous oscines. The conventional theory that furnarioid suboscines are prirnitive and that they and other neotropical suboscines are being pushed into forests by recently immigrating oscines leads to two ecological anomalies: virtual absence of omnlvorous passerines in the carly Cenozoic an:i absence of seed-eat.ing passerines for much of the late Cenozoic . As alternate theory, that of separation of forest-edge suboscines by continental dritr followed by evolut.ion of forest-dwelling furnarioid suboscines in the New World, with open-country oscines either separated by the drift or entering South America early in the Ceno.zoic, removes both anomalies . In western Mato Grosso, a narrow península of Amazoni:an forest follows the Guaporé River southward and eastward on the south side of the Serra dos Parecís, a c2mpo or cerrado-covered plateau of some 500 meters'elevation. This forest península once re.ached east into the drainage of the upper Paraguay River, at least to the town of Barra ( • ) Universidade Estadual de Campinas, SP. ACTA AMAZONICA fl(3) : 379-394 Edwin O'Neill Willis (*) de Bugres. East of Barra de BugrE.s, the remarmng vegetation is mostly dry forest grading into cerrado and pantanal. From Barra de Bugres westward. the foresr is rapidly

Systematics and geographical distribution of the genus Parotocinclus Eigenamnn & Eigenamnn, 1889 (Ostariophysi, Loricariidae)

Abstract: Notes are given on the systematics, geographical distribution and ecology of the genus Parotocinclus. The species are redescribed and five new species (cristatus, amazonensis, jimi, cearensis and minutus) are described. Two well defined groups of species are recogyiized and an Amazonian origin for the genus is postulated, to explain the distribution along a long but narrow belt in eastern South America.

Occurrence of Promoting and Inhibitory Substances in the Seed Arils of Carica Papaya L.

Abstract: SummaryThe germination of seeds of papaya and other species was drastically inhibited by the arils of papaya seeds. Seed extracts contained growth-regulating substances, including a gibberellin-like substance, two cytokinin-like substances and both acidic and neutral inhibitors. The reaction of the inhibitors with FeCl3 solution suggests that these substances are possibly of a phenolic nature.

On the minimal number of parameters in linear multivariable systems

Abstract: In this note an explicit expression is derived specifying the minimal number of parameters by which a given linear dynamic multivariable system may be described.

Response of hybridized (mixed valence) systems to external probes

Abstract: The problem of the response of a hybridized system to an external probe is discussed from a completely quantum-mechanical point of view. An exactly soluble model, which describes qualitatively the mixed-valence states of rare-earth compound solids, is presented. We show that it is possible to obtain regimes of "single response"---e.g., isomer shifts---as well as regimes of "two responses"---e.g., photoelectron emission spectra. The calculation does not involve real time fluctuations. We point out that it would be worthwhile to investigate experimentally intermediate regimes where the characteristic energy of the probe is comparable to the energy separation of the hybridized states.

A study of rice bran oil refining

Abstract: Examination of a number of rice bran oils revealed the presence of monoglycerides (0.5–1.4%) and other hydroxylated compounds such as diglycerides and glucosides. The hydroxyl numbers of the samples ranged from 8.5 to 27, depending on their acidity. On the assumption that the inordinately high refining losses of rice bran oil are due, along with the acidity, to the presence of hydroxylated compounds, the hydroxyl numbers of several samples of that oil were reduced by progressive acetylation with acetic anhydride. This was accompanied by gradual reduction of the refining losses, which seems to support the above mentioned assumption.

The composition of lipids from rice hulls and from the surface of rice caryopsis

Abstract: Samples of hulls, of whole and ground caryopsis and of bran obtained from the Brazilian rice variety IAC 1246, were extracted with hexane and the characteristics and composition of the corresponding lipids were determined The lipids from rice hulls showed a four times higher content of unsaponifiable matter and of free fatty acids than those from rice bran and rice caryopsis There were also differences in the fatty acid composition as evidenced by the presence of 2–3% of saturated C22 and C24 acids and a lower proportion of unsaturated acids in the rice hull lipids On the other hand there was a close resemblance between the rice hull lipids and those on the surface of the caryopsis Chromatographic analysis of the unsaponifiable matter of lipids from rice hulls and caryopsis surface disclosed the presence of hydrocarbons, alcohols and sterols in ascending order, the sterols consisting of about 50% of β-sitosterol, 20–40% of campesterol, 10–20% of stigmasterol and 2–3% of cholesterol On the basis of the above results it was concluded that a preliminary solvent extraction of paddy rice in order to remove the waxy lipids from the hulls and the caryopsis surface would benefit the subsequent milling process and improve the quality of the brown rice and of crude rice bran oil

O ensino das ciências sociais nas escolas profissionais na área da saúde no Brasil

Abstract: Foi realizado em fins de 1971 um levantamento sobre o ensino das ciencias sociais ou do comportamento nas escolas profissionais brasileiras na area da saude. Das 162 escolas existentes, 122 responderam ao questionario. Destas, 85 informaram incluir temas dessas disciplinas em seus curriculos. Apesar desse numero, fica constatada a incipiencia do ensino das ciencias sociais nessas escolas, tanto pelos tipos de cursos ministrados como pelo numero diminuto de cientistas sociais empregados.

An extension of Nachbin’s theorem to differentiable functions on Banach spaces with the approximation property

Abstract: (1) for every xE U, there exis ts fEA such t h a t f ( x ) r (2) for every pair x, yEU, with xr there exists fEA such that f(x)r (3) for every xE U and vEE, with v ~ 0 , there exists fEA such that Df(x)v~O. In [1], Lesmes gave sufficient conditions for a subalgebra AcCm(E) to be dense in (Cm(E), z~), when m = l , and E is a real separable Hilbert space. In fact, he proved that (1), (2), (3) (with U=E) and

Sobre o comportamento de duas linhagens de Schistosoma mansoni Sambon 1907: proposição para método de estudo quantitativo

Abstract: After the commentaries made of host parasitic relations, the authors suggest method for the study of two strains of Schistosoma mansoni. With the rnethod proposed and its experimental use, the authors concluded. For both strains of S. mansoni, the average number of adult worms found m the host was 60 days after infection correlating positively with the number of cercarme whirh the host were exposed to. For both strains there was a positive correlation between the number of adult parasites found in the hosts 60 days after infection and the number of liver granuloma of the same hosts. For both the Belo Horizonte strain as to the Sao Jose dos Campos strain, a negative correlation was found between the number of liver granuloma and the average percentage of host survival. Over a certain number of adult parasites present, there was a significant percentual number of granuloma on the infected mice with the Belo Horizonte strain. Within limits there was a smaller significant percentual survivat of mice infected with the Belo Horizonte strain. For the same number of granuloma, survivat was not significantly different between infected host, by one or the other strain, therefore it is suggested that the hypothesis most likely, is that the pathogenecity of the Belo Horizonte strain results from larger number of granuloma per adult female present. Within the limits established for the host survival index and number of parasites, the band of the degree of pathogenecity ab keeps within close limit of each other for the two strains. Although for the Sao Jose dos Campos strain the number os parasites after the experiment was significantly greater, concluding that a smaller number of Beto Horizonte worms caused on the mice used in the experience, similar levels of pathogenecity and mortality, than a larger number of Sao Jose dos Campos worms.

Alguns aspectos da biologia de Biomphalaria glabrata (Say, 1818) e Biomphalaria tenagophila (D'Orbigny, 1835) (Pulmonata, Planorbidae): I - Duração do período embrionário

Abstract: Foram realizadas observacoes sobre a duracao do periodo embrionario de Biomphalaria glabrata e Biomphalaria tenagophila, durante um ano, em condicoes de laboratorio. As medias, expressas em dias, encontradas para Biomphalaria glabrata e Biomphalaria tenagophila foram respectivamente de 7,6 e 8,0 dias. Essas diferencas nao foram significativas ao nivel de 5%. O desenvolvimento mais rapido dos embrioes ate a eclosao verificou-se na estacao quente, em ambas as especies, quando a temperatura media da agua foi de aproximadamente 28°C. Apos a analise da matriz de correlacao verificou-se que a influencia da temperatura sobre o tempo de desenvolvimento embrionario foi pouco intensa: Biomphalaria glabrata apresentou maior correlacao com a temperatura minima do ambiente (36,2%) e com a temperatura da agua (36,0%) enquanto Biomphalaria tenagophila apresentou maior correlacao com a temperatura minima do ambiente (27,0%).

Application of Hankel matrix to the root location problem

Abstract: It is shown how the well-known Hankel matrix associated with a polynomial f(x) can be employed to obtain information on the location of the zeros of f(x) in a given half plane and in particular to obtain a test for aperiodicity of f(x) .

High resolution phosphorescence emission studies on para-substituted acetophenones at 1.6 K

Abstract: The phosphorescence emission spectra of acetophenone, p -chloroacetophenone, p -bromoacetophenone, p -methoxyacetophenone and p -thiomethoxyacetophenone in p -dimethoxybenzene host crystal at 1.6 K are recorded under high resolution. Detailed vibronic analyses of the emission spectra are carried out and a one dimensional Franck—Condon calculation is performed. Lifetime and optical polarization measurements for the phosphorescence emission of the acetophenone derivatives are also determined. The results lead to the conclusion that the lowest triplet state of acetophenone is n,π* in character with a non-planar configuration resulting from a distortion along the nontotally symmetric vibration of −COCH 3 and −CH 3 wags. Emission spectra from the lowest triplet states of p -methoxyacetophenone and p -thiomethoxyacetophenone are found to originate from π,π* states and have a planar geometry. The phosphorescence spectra of p -chloroacetophenone and p -bromoacetophenone are from a 3 (π,π*) state but have a large amount of n,π* mixed character. The vibrations responsible for such mixing are assigned to the nontotally symmetric modes of −COCH 3 , −Br and −Cl wags.

Field-theoretical approach to vibrational excitation in atom—diatom collinear collisions

Abstract: The field-theoretical atom—diatom scattering equations of Csanak have been tested numerically, assuming a collinear collision model, with an exponential repulsive interaction potential and with a harmonic oscillator approximation for the molecule. Dyson's equation, in its integral form, has been solved obtaining orbitals representing the elastic scattering of an atom off the target and these Dyson's orbitals have been used to evaluate a matrix element containing a transition potential. This has been obtained by approximating Bethe—Salpeter's equation and yields directly the transition amplitudes for inelastic scattering. The results for single and multiple-jumps compare favourably with the exact values of Secrest and Johnson, and refinements of the model are suggested for further improvements.