MORFOPEDOLOGIA E A CONSTITUIÇÃO VEGETAL DE FRAGMENTO FLORESTAL MONTANO

O objetivo deste estudo foi comparar o tipo de solo com a composição vegetal. Em 3600 m² de floresta analisou-se além da composição florística a granulometria e os nutrientes do solo. Identificou-se 23 espécies arbóreas, inclusive exóticas e o solo foi classificado como NEOSSOLO LITÓLICO EUTRÓFICO típico, raso, pouco desenvolvido, com 70% de cascalhos. Embora fértil mostrou-se limitador ao desenvolvimento de raízes, e por isso influencia na composição e estrutura da floresta

Influence Of Spin Reorientation On Magnetocaloric Effect In Nd Al2: A Microscopic Model

We report a theoretical investigation about the influence of the spin reorientation from easy magnetic direction 001 to the applied magnetic field direction 111 on the magnetocaloric properties of Nd Al2. This compound was fully investigated using a model Hamiltonian which includes the Zeeman-exchange interactions and the crystalline electrical field, which are responsible for the magnetic anisotropy. All theoretical results were obtained using the proper model parameters for Nd Al2, found in the literature. The existence of a minimum in magnetic entropy change below the phase transition was predicted and ascribed to the strong jump on the spin reorientation. © 2006 The American Physical Society.745Tishin, A.M., Spichkin, Y.I., (2003) The Magnetocaloric Effect and Its Applications, , Institute of Physics, BristolPecharsky, V.K., Gschneidner Jr., K.A., (1997) Phys. Rev. Lett., 78, p. 4494. , PRLTAO 0031-9007 10.1103/PhysRevLett.78.4494Tegus, O., Brück, E., Buschow, K.H.J., De Boer, F.R., (2002) Nature, 415, p. 150. , NATUAS 0028-0836 10.1038/415150AWada, H., Tanabe, Y., (2001) Appl. Phys. Lett., 79, p. 3302. , APPLAB 0003-6951Wada, H., Morikawa, T., Taniguchi, K., Shibata, T., Yamada, Y., Akishige, Y., (2003) Physica B, 328, p. 114. , PHYBE3 0921-4526 10.1016/S0921-4526(02)01822-7Hu, F., Shen, B., Sun, J., Cheng, Z., Rao, G., Zhang, X., (2001) Appl. Phys. Lett., 78, p. 3675. , APPLAB 0003-6951Fujita, A., Fujieda, S., Hasegawa, Y., Fukamichi, K., (2003) Phys. Rev. B, 67, p. 104416. , PRBMDO 0163-1829 10.1103/PhysRevB.67.104416Brown, G.V., (1976) J. Appl. Phys., 47, p. 3673. , JAPIAU 0021-8979 10.1063/1.323176Von Ranke, P.J., De Oliveira, N.A., Gama, S., (2004) J. Magn. Magn. Mater., 277, p. 78. , JMMMDC 0304-8853 10.1016/j.jmmm.2003.10.013Von Ranke, P.J., De Oliveira, N.A., Gama, S., (2004) Phys. Lett. a, 320, p. 302. , PYLAAG 0375-9601 10.1016/j.physleta.2003.10.067Von Ranke, P.J., De Campos, A., Caron, L., Coelho, A.A., Gama, S., De Oliveira, N.A., (2004) Phys. Rev. B, 70, p. 094410. , PRBMDO 0163-1829 10.1103/PhysRevB.70.094410Gama, S., Coelho, A.A., De Campos, A., Carvalho, A.M., Gandra, F.C.G., Von Ranke, P., De Oliveira, N.A., (2004) Phys. Rev. Lett., 93, p. 237202. , PRLTAO 0031-9007 10.1103/PhysRevLett.93.237202Von Ranke, P.J., De Oliveira, N.A., Mello, C., Carvalho, A.M., Gama, S., (2005) Phys. Rev. B, 71, p. 054410. , PRBMDO 0163-1829 10.1103/PhysRevB.71.054410Von Ranke, P.J., Gama, S., Coelho, A.A., De Campos, A., Carvalho, A.M., Gandra, F.C.G., De Oliveira, N.A., (2006) Phys. Rev. B, 73, p. 014415. , PRBMDO 0163-1829 10.1103/PhysRevB.73.014415Von Ranke, P.J., Pecharsky, V.K., Gschneidner, K.A., Korte, B.J., (1998) Phys. Rev. B, 58, p. 14436. , PRBMDO 0163-1829 10.1103/PhysRevB.58.14436Von Ranke, P.J., Mota, M.A., Grangeia, D.F., Carvalho, A.M., Gandra, F.C.G., Coelho, A.A., Caldas, A., Gama, S., (2004) Phys. Rev. B, 70, p. 134428. , PRBMDO 0163-1829 10.1103/PhysRevB.70.134428Lima, A.L., Tsokol, A.O., Gschneidner Jr., K.A., Pecharsky, V.K., Lograsso, T.A., Schlagel, D.L., (2005) Phys. Rev. B, 72, p. 024403. , PRBMDO 0163-1829 10.1103/PhysRevB.72.024403Von Ranke, P.J., De Oliveira, I.G., Guimaraes, A.P., Da Silva, X.A., (2000) Phys. Rev. B, 61, p. 447. , PRBMDO 0163-1829 10.1103/PhysRevB.61.447Lea, K.R., Leask, M.J.M., Wolf, W.P., (1962) J. Phys. Chem. Solids, 33, p. 1381. , JPCSAW 0022-3697Stevens, K.W.H., (1952) Proc. Phys. Soc., London, Sect. a, 65, p. 209. , PPSAAM 0370-1298 10.1088/0370-1298/65/3/308Purwins, H.G., Leson, A., (1990) Adv. Phys., 39, p. 309. , ADPHAH 0001-8732 10.1080/00018739000101511Bak, P., (1974) J. Phys. C, 7, p. 4097. , JPSOAW 0022-3719 10.1088/0022-3719/7/22/014Nereson, N., Olsen, C., Arnold, G., (1996) J. Appl. Phys., 37, p. 4575. , JAPIAU 0021-8979 10.1063/1.1708083Deenadas, C., Thompson, A.W., Graig, R.S., Wallace, W.E., (1971) J. Phys. Chem. Solids, 32, p. 1843. , JPCSAW 0022-3697Inoue, T., Sankar, S.G., Graig, R.S., Wallace, W.E., Gschneidner Jr., K.A., (1997) J. Phys. Chem. Solids, 38, p. 487. , JPCSAW 0022-3697Barbara, B., Boucherle, J.X., Michelutti, B., Rossignol, M.F., (1979) Solid State Commun., 31, p. 477. , SSCOA4 0038-1098Barbara, B., Rossignol, M.F., Boucherle, J.X., (1975) Phys. Lett., 55, p. 321. , PYLAAG 0375-9601 10.1016/0375-9601(75)90489-

Are the magnetic fields of millisecond pulsars ~ 10^8 G?

It is generally assumed that the magnetic fields of millisecond pulsars (MSPs) are $\sim 10^{8}$G. We argue that this may not be true and the fields may be appreciably greater. We present six evidences for this: (1) The $\sim 10^{8}$ G field estimate is based on magnetic dipole emission losses which is shown to be questionable; (2) The MSPs in low mass X-ray binaries (LMXBs) are claimed to have $< 10^{11}$ G on the basis of a Rayleygh-Taylor instability accretion argument. We show that the accretion argument is questionable and the upper limit $10^{11}$ G may be much higher; (3) Low magnetic field neutron stars have difficulty being produced in LMXBs; (4) MSPs may still be accreting indicating a much higher magnetic field; (5) The data that predict $\sim 10^{8}$ G for MSPs also predict ages on the order of, and greater than, ten billion years, which is much greater than normal pulsars. If the predicted ages are wrong, most likely the predicted $\sim 10^{8}$ G fields of MSPs are wrong; (6) When magnetic fields are measured directly with cyclotron lines in X-ray binaries, fields $\gg 10^{8}$ G are indicated. Other scenarios should be investigated. One such scenario is the following. Over 85% of MSPs are confirmed members of a binary. It is possible that all MSPs are in large separation binaries having magnetic fields $> 10^{8}$ G with their magnetic dipole emission being balanced by low level accretion from their companions.Comment: 16 pages, accept for publication in Astrophysics and Space Scienc

Quasiparticle Interactions in Fractional Quantum Hall Systems: Justification of Different Hierarchy Schemes

The pseudopotentials describing the interactions of quasiparticles in fractional quantum Hall (FQH) states are studied. Rules for the identification of incompressible quantum fluid ground states are found, based upon the form of the pseudopotentials. States belonging to the Jain sequence nu=n/(1+2pn), where n and p are integers, appear to be the only incompressible states in the thermodynamic limit, although other FQH hierarchy states occur for finite size systems. This explains the success of the composite Fermion picture.Comment: RevTeX, 10 pages, 7 EPS figures, submitted fo Phys.Rev.

Magnetocaloric Effect Due To Spin Reorientation In The Crystalline Electrical Field: Theory Applied To Dy Al2

We report a way of obtaining the magnetocaloric effect due to the crystal electrical-field quenching of the total angular momentum in a magnetic system where a strong spin reorientation is present. The theoretical model is applied to Dy Al2 and the results predict a considerable magnetic entropy change by rotating a single crystal in a fixed magnetic field. The obtained temperature and magnetic-field dependencies of the magnetization component along the 111-crystallographic direction are in good agreement with the recently reported experimental data. © 2007 The American Physical Society.7518Pecharsky, V.K., Gschneidner Jr., K.A., (1997) Phys. Rev. Lett., 78, p. 4494. , PRLTAO 0031-9007 10.1103/PhysRevLett.78.4494Choe, W., Pecharsky, V.K., Pecharsky, A.O., Gschneidner Jr., K.A., Young Jr., V.G., Miller, G.J., (2000) Phys. Rev. Lett., 84, p. 4617. , PRLTAO 0031-9007 10.1103/PhysRevLett.84.4617Provenzano, V., Shapiro, A.J., Shull, R.D., (2004) Nature (London), 429, p. 853. , NATUAS 0028-0836 10.1038/nature02657Tegus, O., Brück, E., Buschow, K.H.J., De Boer, F.R., (2002) Nature (London), 415, p. 150. , NATUAS 0028-0836 10.1038/415150AWada, H., Tanabe, Y., (2001) Appl. Phys. Lett., 79, p. 3302. , APPLAB 0003-6951 10.1063/1.1419048Wada, H., Morikawa, T., Taniguchi, K., Shibata, T., Yamada, Y., Akishige, Y., (2003) Physica B, 328, p. 114. , PHYBE3 0921-4526 10.1016/S0921-4526(02)01822-7Hu, F., Shen, B., Sun, J., Cheng, Z., Rao, G., Zhang, X., (2001) Appl. Phys. Lett., 78, p. 3675. , APPLAB 0003-6951 10.1063/1.1375836Fujita, A., Fujieda, S., Hasegawa, Y., Fukamichi, K., (2003) Phys. Rev. B, 67, p. 104416. , PRBMDO 0163-1829 10.1103/PhysRevB.67.104416Von Ranke, P.J., De Oliveira, N.A., Gama, S., (2004) J. Magn. Magn. Mater., 277, p. 78. , JMMMDC 0304-8853 10.1016/j.jmmm.2003.10.013Von Ranke, P.J., De Campos, N.A., Caron, L., Coelho, A.A., Gama, S., De Oliveira, N.A., (2004) Phys. Rev. B, 70, p. 094410. , PRBMDO 0163-1829 10.1103/PhysRevB.70.094410Von Ranke, P.J., De Oliveira, N.A., Gama, S., (2004) Phys. Lett. a, 320, p. 302. , PYLAAG 0375-9601 10.1016/j.physleta.2003.10.067Gama, S., Coelho, A.A., De Campos, A., Carvalho, A.M., Gandra, F.C.G., Von Ranke, P.J., De Oliveira, N.A., (2004) Phys. Rev. Lett., 93, p. 237202. , PRLTAO 0031-9007 10.1103/PhysRevLett.93.237202Von Ranke, P.J., De Oliveira, N.A., Mello, C., Carvalho, A.M., Gama, S., (2005) Phys. Rev. B, 71, p. 054410. , PRBMDO 0163-1829 10.1103/PhysRevB.71.054410Von Ranke, P.J., Gama, S., Coelho, A.A., De Campos, A., Carvalho, A.M., Gandra, F.C.G., De Oliveira, N.A., (2006) Phys. Rev. B, 73, p. 014415. , PRBMDO 0163-1829 10.1103/PhysRevB.73.014415Von Ranke, P.J., Pecharsky, V.K., Gschneidner, K.A., Korte, B.J., (1998) Phys. Rev. B, 58, p. 14436. , PRBMDO 0163-1829 10.1103/PhysRevB.58.14436Von Ranke, P.J., Mota, M.A., Grangeia, D.F., Carvalho, A.M., Gandra, F.C.G., Coelho, A.A., Caldas, A., Gama, S., (2004) Phys. Rev. B, 70, p. 134428. , PRBMDO 0163-1829 10.1103/PhysRevB.70.134428Lima, A.L., Oliveira, I.S., Gomes, A.M., Von Ranke, P.J., (2002) Phys. Rev. B, 65, p. 172411. , PRBMDO 0163-1829 10.1103/PhysRevB.65.172411Von Ranke, P.J., Lima, A.L., Nobrega, E.P., Da Silva, X.A., Guimarães, A.P., Oliveira, I.S., (2000) Phys. Rev. B, 63, p. 024422. , PRBMDO 0163-1829 10.1103/PhysRevB.63.024422Lima, A.L., Tsokol, A.O., Gschneidner Jr., K.A., Pecharky, V.K., Lograsso, T.A., Schlagel, D.L., (2005) Phys. Rev. B, 72, p. 024403. , PRBMDO 0163-1829 10.1103/PhysRevB.72.024403Von Ranke, P.J., De Oliveira, I.G., Guimarães, A.P., Da Silva, X.A., (2000) Phys. Rev. B, 61, p. 447. , PRBMDO 0163-1829 10.1103/PhysRevB.61.447Bak, P., (1974) J. Phys. C, 7, p. 4097. , JPSOAW 0022-3719 10.1088/0022-3719/7/22/014Hutchings., M.T., (1964) Solid State Phys., 16, p. 227. , SSPHAE 0081-1947Lea, K.R., Leask, M.J.M., Wolf, W.P., (1962) J. Phys. Chem. Solids, 33, p. 1381. , JPCSAW 0022-3697Stevens, K.W.H., (1952) Proc. Phys. Soc., London, Sect. a, 65, p. 209. , PPSAAM 0370-1298 10.1088/0370-1298/65/3/308Purwins, H.G., Leson, A., (1990) Adv. Phys., 39, p. 309. , ADPHAH 0001-8732 10.1080/00018739000101511Kuz'Min, M.D., Tishin, A.M., (1991) J. Phys. D, 24, p. 2039. , JPAPBE 0022-3727 10.1088/0022-3727/24/11/02

Physical distancing and mental well-being in youth population of Portugal and Brazil during the COVID-19 pandemic

Funding Information: This paper was made possible with the scholarship from FCT and to the Unidade de I&D CHRC – Comprehensive Health Research Centre (UI/BD/150908/2021). Also to CAPES (Code 001) and CNPQ (Research Productivity Scholarship Process 304483/2018-4). The databases are anonymous, guaranteeing data confidentiality. Funding Information: Fundação para a ciência e tecnologia (FCT) and the Unidade de I&D CHRC – Comprehensive Health Research Centre (UI/BD/150908/2021). Also to CAPES (Code 001) and CNPQ (Research Productivity Scholarship Process 304483/2018-4) Publisher Copyright: © 2022Background: The COVID-19 pandemic may affect youth's physical and mental well-being, partially because of the countries' rules to contain the virus from spreading. However, there is still uncertainty about the impact of physical distancing on youth's mental health. We aimed to estimate the prevalence of feeling agitated, anxious, down, sad, or low mood (FNF) due to physical distance measures and verify which factors are associated with young Portuguese and Brazilian people. Methods: We used cross-sectional data from the instrument "COVID-19 Barometer: Social Opinion"in Portugal (March 2020 and September 2021) and from "COVID-19 Social Thermometer"in Brazil (August 2020 to April 2021); these surveys included data regarding the health and socioeconomic impact on the population. The health and sociodemographic variables of the two countries were summarized as absolute and relative frequencies. A multivariable logistic regression model was fit by country to estimate the relation between FNF and selected variables of interest. Results: Approximately 36% of the sample studied reported anxiety, agitation, sadness, or low mood almost every day in Portugal and 52% in Brazil due to physical distancing. In Portugal, having more than two comorbidities represented a greater chance of experiencing FNF every day or almost every day (odds ratio [OR] = 1.51 [CI: 1.22-1.87]) than those without comorbidities. In contrast, having a university education level represented a protector factor (OR = 0.76 [CI: 0.67-0.88]). In Brazil, being unemployed increased the chance of FNF compared to students (OR = 11.2). Conclusions: Physical distancing measures have impacted the mental well-being of the young population in Portugal and Brazil. The countries must make a quick effort to attend to and protect young people's well-being and mental health in the changing context of the current pandemic.publishersversioninpres