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The family of crystals known as Tutton's salts plays a significant role in physics and chemistry; because they are used in phase transition studies and to define models applied to materials. The importance of salts in material engineering is recent, as in applications in adiabatic degaussing refrigerators and solid-state anodes. Studies of the (NH4)2Ni(SO4)2∙6H2O and (NH4)2Co(SO4)2·6H2O are widely found in literature but do not occur for the mixture of both. In this research, we studied mixed crystals of the general chemical formula (NH4)2NixCo(1-x)(SO4)2·6H2O with x ranging from 0 to 1, utilizing x = 0.7. The objective is to study the modifications caused owing to the ion's weighted composition in the formation of the solid solution and compare it with the pure salts. For this, the growth of these crystals is discussed based on ICP-OES results and optical microscopy concerning the crystal growth theory. The discussion also relates the Raman spectra of the salts with molecular changes according to structured group theory, qualitatively characterizing its crystalline structure. Finally, a Single-crystal X-ray study solves and confirms the structure of pure salts and mixed salt, quantitatively characterizing their crystal structure.

O presente artigo tem como objetivo demonstrar a necessidade de planejamento tributário internacional para as corporações que desejam competir nomercado em escala global, como os impactos da legislação tributária favorecida são tratados pelo ordenamento jurídico brasileiro, e, ainda, como se dáa constituição de fatos jurídicos através da linguagem probatória, especialmente quanto aos preços de transferência de empresas multinacionais.

Systemic arterial hypertension (SAH) is a major health problem around the world and its development has been associated with exceeding salt consumption by the modern society. The mechanisms by which salt consumption increase blood pressure (BP) involve several homeostatic systems but many details have not yet been fully elucidated. Evidences accumulated over the last 60 decades raised the involvement of the immune system in the hypertension development and opened a range of possibilities for new therapeutic targets. Green propolis is a promising natural product with potent anti-inflammatory properties acting on specific targets, most of them participating in the gut-brain axis of the sodium-dependent hypertension. New anti-hypertensive products reinforce the therapeutic arsenal improving the corollary of choices, especially in those cases where patients are resistant or refractory to conventional therapy. This review sought to bring the newest advances in the field articulating evidences that show a cross-talking between inflammation and the central mechanisms involved with the sodium-dependent hypertension as well as the stablished actions of green propolis and some of its biologically active compounds on the immune cells and cytokines that would be involved with its anti-hypertensive properties.

O presente artigo objetivou a demonstração da projeção de viabilidade econômica, estrutural e socioambiental da criação de usinas híbridas e associadas no Brasil, mediante análise dos avanços trazidos na Resolução 954/2021 da ANEEL. Respeitado o corte metodológico necessário para fazer-se conhecer o objeto, utilizou-se os métodos empírico-dialético e bibliográfico para atingir, enquanto objetivo específico, o entendimento acerca das vantagens, desvantagens e desafios da complementariedade energética, por meio da utilização de duas ou mais matrizes em um mesmo local, bem como seus benefícios frente a problemática sazonal da crise hídrica, e consequentemente, no Brasil, energética, razões estas que justificam o presente estudo. A conclusão fora pelo potencial positivo da hibridização energética.

O presente artigo objetivou a demonstração da influência da bitributação das empresas transacionais no acolhimento de investimentos estrangeiros no Brasil, no contexto das relações internacionais em cotejo com a afirmação de soberanias no processo dinâmico de circulação transnacional de rendimentos produzidos. Respeitado o corte metodológico necessário para fazer-se conhecer o objeto, utilizou-se os métodos empírico-dialético e bibliográfico para atingir, enquanto objetivo específico, a demonstração das bases de tributação universais e correlatos critérios de incidência, e seus impactos nas relações internacionais mantidas entre pessoas jurídicas nacionais que mantêm controladas ou coligadas no exterior, cuja conclusão fora pela viabilidade da incidência interna dos tratados.

Sodium is the main cation present in the extracellular fluid. Sodium and water content in the body are responsible for volume and osmotic homeostasis through mechanisms involving sodium and water excretion and intake. When body sodium content decreases below the homeostatic threshold, a condition termed sodium deficiency, highly motivated sodium seeking, and intake occurs. This is termed sodium appetite. Classically, sodium and water intakes are controlled by a number of neuroendocrine mechanisms that include signaling molecules from the renin-angiotensin-aldosterone system acting in the central nervous system (CNS). However, recent findings have shown that sodium and water intakes can also be influenced by inflammatory agents and mediators acting in the CNS. For instance, central infusion of IL-1β or TNF-α can directly affect sodium and water consumption in animal models. Some dietary conditions, such as high salt intake, have been shown to change the intestinal microbiome composition, stimulating the immune branch of the gut-brain axis through the production of inflammatory cytokines, such as IL-17, which can stimulate the brain immune system. In this review, we address the latest findings supporting the hypothesis that immune signaling in the brain could produce a reduction in thirst and sodium appetite and, therefore, contribute to sodium intake control.

Submitted by lfisabel@stj.jus.br (lfisabel@stj.jus.br) on 2022-08-05T17:59:10Z No. of bitstreams: 2 teoria_norma_juridica_messias.pdf: 3114551 bytes, checksum: e7bc8d3b019f143a9cf260b469981a27 (MD5) license.txt: 1239 bytes, checksum: c9b4c351324448672315a00808efb725 (MD5) Approved for entry into archive by betanial@stj.jus.br (betanial@stj.jus.br) on 2022-08-05T22:08:51Z (GMT) No. of bitstreams: 2 license.txt: 1239 bytes, checksum: c9b4c351324448672315a00808efb725 (MD5) teoria_norma_juridica_messias.pdf: 3114551 bytes, checksum: e7bc8d3b019f143a9cf260b469981a27 (MD5) Made available in DSpace on 2022-08-05T22:08:51Z (GMT). No. of bitstreams: 2 license.txt: 1239 bytes, checksum: c9b4c351324448672315a00808efb725 (MD5) teoria_norma_juridica_messias.pdf: 3114551 bytes, checksum: e7bc8d3b019f143a9cf260b469981a27 (MD5) Previous issue date: 2022

In this paper, we discuss the behavior of a linear classical parametric amplifier in the presence of white noise and give theoretical estimates of the noise spectral density based on approximate Green’s functions obtained by using averaging techniques. To validate our theory, we compare the analytical results with experimental data from an analog circuit and with numerical simulations of the model’s stochastic differential equations. The experimental data were accurately described by our model. Moreover, we noticed spectral components in the output signal of the amplifier, which are due to noisy precursors of instability. The position, width, and magnitude of these components are in agreement with the noise spectral density obtained by the theory proposed here.

Psidium guajava (guava) leaves extract displays anti-hypertensive properties by mechanisms not yet fully understood. Here, we investigated whether sympathetic drive and immune signaling mechanisms are involved with the antihypertensive effect of the guava extract in a model of salt-dependent hypertension. Raw guava extract (rPsE) was characterized by colorimetric and UPLC-MS techniques. Two doses of rPsE (100 and 200 mg/kg) were evaluated for anti-hypertensive effect using a suspension system (PsE). Weaned male Wistar rats were put on a high-salt diet (HSD, 0.90 % Na

Submitted by jualmei@stj.jus.br (jualmei@stj.jus.br) on 2021-09-21T01:11:23Z No. of bitstreams: 2 principio_seletividade_aplicavel_messias.pdf: 152910 bytes, checksum: b78168bd1b52c9b24eef4b1af84a2a8d (MD5) license.txt: 1239 bytes, checksum: c9b4c351324448672315a00808efb725 (MD5) Approved for entry into archive by betanial@stj.jus.br (betanial@stj.jus.br) on 2021-09-22T19:02:03Z (GMT) No. of bitstreams: 2 principio_seletividade_aplicavel_messias.pdf: 152910 bytes, checksum: b78168bd1b52c9b24eef4b1af84a2a8d (MD5) license.txt: 1239 bytes, checksum: c9b4c351324448672315a00808efb725 (MD5) Made available in DSpace on 2021-09-22T19:02:03Z (GMT). No. of bitstreams: 2 principio_seletividade_aplicavel_messias.pdf: 152910 bytes, checksum: b78168bd1b52c9b24eef4b1af84a2a8d (MD5) license.txt: 1239 bytes, checksum: c9b4c351324448672315a00808efb725 (MD5) Previous issue date: 2021

Submitted by phemiran@stj.jus.br (phemiran@stj.jus.br) on 2022-01-26T18:55:16Z No. of bitstreams: 2 contradicao_sistema_direito_messias.pdf: 2405752 bytes, checksum: 03c2c486ec282f74de56a86fb7c22140 (MD5) license.txt: 1239 bytes, checksum: c9b4c351324448672315a00808efb725 (MD5) Approved for entry into archive by betanial@stj.jus.br (betanial@stj.jus.br) on 2022-02-02T12:36:29Z (GMT) No. of bitstreams: 2 contradicao_sistema_direito_messias.pdf: 2405752 bytes, checksum: 03c2c486ec282f74de56a86fb7c22140 (MD5) license.txt: 1239 bytes, checksum: c9b4c351324448672315a00808efb725 (MD5) Made available in DSpace on 2022-02-02T12:36:29Z (GMT). No. of bitstreams: 2 contradicao_sistema_direito_messias.pdf: 2405752 bytes, checksum: 03c2c486ec282f74de56a86fb7c22140 (MD5) license.txt: 1239 bytes, checksum: c9b4c351324448672315a00808efb725 (MD5) Previous issue date: 2021

In this work, we adapt the epidemiological SIR model to study the evolution of the dissemination of COVID-19 in Germany and Brazil (nationally, in the State of Paraiba, and in the City of Campina Grande). We prove the well posedness and the continuous dependence of the model dynamics on its parameters. We also propose a simple probabilistic method for the evolution of the active cases that is instrumental for the automatic estimation of parameters of the epidemiological model. We obtained statistical estimates of the active cases based the probabilistic method and on the confirmed cases data. From this estimated time series we obtained a time-dependent contagion rate, which reflects a lower or higher adherence to social distancing by the involved populations. By also analysing the data on daily deaths, we obtained the daily lethality and recovery rates. We then integrate the equations of motion of the model using these time-dependent parameters. We validate our epidemiological model by fitting the official data of confirmed, recovered, death, and active cases due to the pandemic with the theoretical predictions. We obtained very good fits of the data with this method. The automated procedure developed here could be used for basically any population with a minimum of extra work. Finally, we also propose and validate a forecasting method based on Markov chains for the evolution of the epidemiological data for up to two weeks., 37 pages, 9 figures

New findings What is the central question of this study? How does swimming exercise training impact hydro-electrolytic balance, renal function, sympathetic contribution to resting blood pressure and cerebrospinal fluid (CSF) [Na+ ] in rats fed a high-sodium diet from weaning? What is the main finding and its importance? An exercise-dependent reduction in blood pressure was associated with decreased CSF [Na+ ], sympathetically driven vasomotor tonus and renal fibrosis indicating that the anti-hypertensive effects of swimming training in rats fed a high-sodium diet might involve neurogenic mechanisms regulated by sodium levels in the CSF rather than changes in blood volume. Abstract High sodium intake is an important factor associated with hypertension. High-sodium intake with exercise training can modify homeostatic hydro-electrolytic balance, but the effects of this association are mostly unknown. In this study, we sought to investigate the effects of swimming training (ST) on cerebrospinal fluid (CSF) Na+ concentration, sympathetic drive, blood pressure (BP) and renal function of rats fed a 0.9% Na+ (equivalent to 2% NaCl) diet with free access to water for 22 weeks after weaning. Male Wistar rats were assigned to two cohorts: (1) fed standard diet (SD) and (2) fed high-sodium (HS) diet. Each cohort was further divided into trained and sedentary groups. ST normalised BP levels of HS rats as well as the higher sympathetically related pressor activity assessed by pharmacological blockade of ganglionic transmission (hexamethonium). ST preserved the renal function and attenuated the glomerular shrinkage elicited by HS. No change in blood volume was found among the groups. CSF [Na+ ] levels were higher in sedentary HS rats but were reduced by ST. Our findings showed that ST effectively normalised BP of HS rats, independent of its effects on hydro-electrolytic balance, which might involve neurogenic mechanisms regulated by Na+ levels in the CSF as well as renal protection.

The substitution of cobalt, present in the commercial binder metal matrix commonly used by the industry, was analyzed: 25,2%Fe-49,5%Cu-24,1%Co – NEXT 100® by the niobium element of the Fe-Cu-Co system, obtaining 4 metal matrices: 28,34%Fe–56,66%Cu–15%Nb; 25%Fe–50%Cu–25%Nb; 21,67%Fe–43,33%C–35%Nb; 18,34%Fe–36,66%Cu–45%Nb. This study aims to evaluate the behavior of metal matrices to better choose the type of matrix to be used in the manufacture of diamond tools. The metal powders were blended according to the compositions of each metal matrix and then hot pressed at 800o /35MPa / 3min, thus occurring the sintering. The sintered samples of each metal matrix were conducted to the Abrasion Resistance test in order to verify the wear, for the accumulated times of 2, 6, 12 and 20 minutes. In these metal matrices, density, porosity and Vickers hardness (HV5) tests were performed to better understand the wear suffered by the samples. Thus, the metal matrix 25% Fe-50%Cu-25%Nb presented, in the general context of the properties and from the abrasive point of view, satisfactory results capable of replacing the NEXT 100 matrix.

RESUMO O compósito WC-10%Co também conhecido como Metal Duro de Carbeto de Tungstênico (WC) com Cobalto (Co) é um dos materiais mais produzidas pela indústria fabricante de metal duro, entretanto busca-se o melhor entendimento sobre o efeito de parâmetros de processo sobre as suas características estruturais, especialmente no que diz respeito à formação de fases metaestáveis – fases η. Neste trabalho, usamos o método de Rietveld aliado a difração de raios X (DRX), a microscopia eletrônica de varredura (MEV) e o Brunauer – Emmett – Teller (BET) para investigar a estrutura das matérias-primas utilizadas na produção de metal duro. Os tamanhos das partículas assim como as morfologias identificadas para os pós de WC e Co são reflexos do seu processo de fabricação que, introduzem tensões residuais para o pó de WC, a baixa cristalinidade e significante parcela de amorfo para o pó de Co. Estas características foram identificadas com a difração de raios X em comparação com o padrão de difração obtido e os bancos de dados cristalográficos. Após o processo de mistura dos pós foram quantificadas as fases e identificados os efeitos desse processo sobre as células unitárias de cada fase. Este trabalho mostra que a rota de caracterização empregada, com o uso do método de Rietveld, é eficiente para analisar a estrutura desses materiais durante seu processamento. Foi possível observar que o processo de mistura utilizando equipamento de moagem de alta energia promove alteração na densidade das células unitárias do WC “empurrando” átomos de Co para dentro de sua estrutura. Isso pode vir a acelerar o processo de dissolução de grande parte das partículas de WC durante a sinterização, contribuindo para a formação acentuada das fases metaestáveis eta – η, prejudicando o equilíbrio entre as propriedades mecânicas de dureza e tenacidade à fratura tornando a ferramenta ou peça muito dura e pouco tenaz. ABSTRACT The composite WC-10% Co is one of the materials most produced by the hardmetal fabrication industry. However, a better understanding of the effect of process parameters on their structural characteristics is sought, especially with respect to the formation of metastable phases - η. In this work, we used the Rietveld Method with X - Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Brunauer - Emmett - Teller (BET) to investigate the structure of the raw materials used in the production of hardmetal. The particle sizes as well as the identified morphologies for the WC and Co powders are reflections of their manufacturing process, which introduce residual stresses for WC powder, low crystallinity and a significant amorphous portion for Co powder. These characteristics were identified with XRD in comparison to the obtained diffraction pattern and crystallographic databases. After the powder mixing process, the phases were quantified and the effects of this process were identified on the unit cells of each phase. This work shows that the characterization route using the Rietveld Method is efficient to analyze the structure of these materials during their processing. It was observed that the mixing process using high energy milling equipment promotes a change in the density of WC unit cells by “pushing” Co atoms into their structure. This may accelerate the dissolution process of most WC particles during sintering. And contribute to the accentuated formation of metastable phases eta – η, damaging the balance between the mechanical properties of hardness and fracture toughness making the tool or piece very hard and not very tenacious.

Here we present a one-degree-of-freedom model of a nonlinear parametrically-driven resonator in the presence of a small added ac signal that has spectral responses similar to a frequency comb. The proposed nonlinear resonator has a spread spectrum response with a series of narrow peaks that are equally spaced in frequency. The system displays this behavior most strongly after a symmetry-breaking bifurcation at the onset of parametric instability. We further show that the added ac signal can suppress the transition to parametric instability in the nonlinear oscillator. We also show that the averaging method is able to capture the essential dynamics involved., 21 pages, 10 figures, submitted for publication. Corrected nomenclature, added more references and discussion, replaced figures, added one figure

Alelopatia é definida pela Sociedade Internacional de Alelopatia como a ciência que estuda qualquer processo envolvendo essencialmente os metabólitos secundários produzidos pelas plantas, algas, bactérias e fungos que influenciam o crescimento e desenvolvimento de sistemas agrícolas e biológicos, incluindo efeitos positivos e negativos. Entretanto, diversas dúvidas são evidenciadas em novos pesquisadores da área, como o surgimento e evolução dessa ciência. Dessa forma, reunimos de forma didática algumas informações importantes acerca da alelopatia, as quais estão distribuídas em (1) Alelopatia: Histórico e Definições, (2) Modo de Ação dos Aleloquímicos e (3) Natureza Química dos Aleloquímicos, a fim de nortear os novos pesquisadores e possibilitar a utilização destas informações em sala de aula como recurso teórico.

Submitted by rafaelrn@stj.jus.br (rafaelrn@stj.jus.br) on 2019-09-23T17:08:50Z No. of bitstreams: 2 importancia_atos_fala_messias.pdf: 284293 bytes, checksum: 9f710392454965488700978fc58eb043 (MD5) license.txt: 1239 bytes, checksum: c9b4c351324448672315a00808efb725 (MD5) Approved for entry into archive by Roberta Marins (rmarins@stj.jus.br) on 2019-09-25T16:30:53Z (GMT) No. of bitstreams: 2 importancia_atos_fala_messias.pdf: 284293 bytes, checksum: 9f710392454965488700978fc58eb043 (MD5) license.txt: 1239 bytes, checksum: c9b4c351324448672315a00808efb725 (MD5) Made available in DSpace on 2019-09-25T16:30:53Z (GMT). No. of bitstreams: 2 importancia_atos_fala_messias.pdf: 284293 bytes, checksum: 9f710392454965488700978fc58eb043 (MD5) license.txt: 1239 bytes, checksum: c9b4c351324448672315a00808efb725 (MD5) Previous issue date: 2019

Submitted by leitem@stj.jus.br (leitem@stj.jus.br) on 2019-10-18T15:44:52Z No. of bitstreams: 2 reclassificacao_bens_entre_messias.pdf: 866235 bytes, checksum: 56e4d58bd7dbb0ee628d6a56b1d6d54c (MD5) license.txt: 1239 bytes, checksum: c9b4c351324448672315a00808efb725 (MD5) Approved for entry into archive by Roberta Marins (rmarins@stj.jus.br) on 2019-10-18T18:48:49Z (GMT) No. of bitstreams: 2 license.txt: 1239 bytes, checksum: c9b4c351324448672315a00808efb725 (MD5) reclassificacao_bens_entre_messias.pdf: 866235 bytes, checksum: 56e4d58bd7dbb0ee628d6a56b1d6d54c (MD5) Made available in DSpace on 2019-10-18T18:48:49Z (GMT). No. of bitstreams: 2 license.txt: 1239 bytes, checksum: c9b4c351324448672315a00808efb725 (MD5) reclassificacao_bens_entre_messias.pdf: 866235 bytes, checksum: 56e4d58bd7dbb0ee628d6a56b1d6d54c (MD5) Previous issue date: 2019

Submitted by Iury Batista (iurys@stj.jus.br) on 2018-12-19T17:39:11Z No. of bitstreams: 2 estrutura_norma_juridica_messias.pdf: 3234386 bytes, checksum: e4bf0da849255e60de0310087474ff55 (MD5) license.txt: 1239 bytes, checksum: c9b4c351324448672315a00808efb725 (MD5) Approved for entry into archive by Patrícia Rabello (rabello@stj.jus.br) on 2019-01-10T18:55:59Z (GMT) No. of bitstreams: 2 estrutura_norma_juridica_messias.pdf: 3234386 bytes, checksum: e4bf0da849255e60de0310087474ff55 (MD5) license.txt: 1239 bytes, checksum: c9b4c351324448672315a00808efb725 (MD5) Made available in DSpace on 2019-01-10T18:55:59Z (GMT). No. of bitstreams: 2 estrutura_norma_juridica_messias.pdf: 3234386 bytes, checksum: e4bf0da849255e60de0310087474ff55 (MD5) license.txt: 1239 bytes, checksum: c9b4c351324448672315a00808efb725 (MD5) Previous issue date: 2018

In this paper, we present the design, fabrication and calibration of a passive UHF RFID tag based soil moisture and environment temperature sensor. The inter-digital double-sided capacitive sensor developed modifies its capacitance as the soil moisture changes, due to modification of the soil permittivity. The implemented smart tag includes an external sensor front-end that is capable to process analog sensors and send digitized measurements to the reader. In order to obtain reliable readings, a process of calibration was performed and described. The used RFID chip also includes a built-in temperature sensor. The developed sensor tag presented a 6.95 ADC LSB variation per soil water content percentage and the capability to measure temperatures in a range of 0.3–59.6 °C with a 0.058°C resolution.

In this study, the original tourmaline and beryl mineral samples have been collected from a Brazilian pegmatite. The objective of this study was to examine the adsorption behavior of Brazilian ciclosilicate samples, towards divalent metals (Pb2+, Mn2+, and Zn2+) in ethanol solution has been studies by a batch technique. The ciclosilicate samples were characterized by elemental analysis, Fourier transform infrared spectroscopy, helium picnometry, mercury porosity, and nitrogen adsorption–desorption. The Langmuir expression for adsorption isotherm was applied in order to determine the adsorption capacity to form a monolayer and the constant related to the adsorption intensity. In aqueous solution there was a significant adsorption increase with the temperature and pronounced synergistic effects were observed. The maximum number of moles adsorbed was determined to be 12.48 and 11.49 mmol/g for systems Pb2+/beryl and Pb2+/tourmaline, respectively. The energetic effects caused by metal cations adsorption were determined through calorimetric titrations. Thermodynamics indicated the existence of favorable conditions for such Pb2+-, Mn2+-, and Zn2+–OH interactions. Keywords: Industrial minerals, Environmental, Pollution, Surface modification, Wasteprocesing

Kaolinite clay samples from Amazon region, Para state, Brazil, were first intercalated with dimethylsulfoxide (DS) followed by immobilization of (3-aminopropyl)triethoxysilane (APS). The samples were characterized by X-ray diffraction, and zero point charge determination. The chemically modified kaolinite samples showed modification of its physical–chemical properties including: specific area of 25.2–421.5 m 2 g −1 for K 1 and K 1-DS/APS , and 24.7–425.9 m 2 g −1 for K 2 and K 2-DS/APS . New d 0 0 1 values of 1.313 and 1.319 nm for the modified kaolinites K 1-DS/APS and K 2-DS/APS , respectively, were obtained. From electrical property investigations an increase in electric permittivity was observed for real ( ɛ | ) and imaginary ( ɛ || ) at low frequencies, which are probably related to the interlayer molecules. The energetic effect caused by mercury cation adsorption was determined through calorimetric titration at the solid–liquid interface and gave net thermal effects that enabled the calculation of the exothermic enthalpic values and the equilibrium constant. From these values negative Gibbs free energy and positive entropy were calculated and this set of thermodynamic data is favorable for mercury/basic center interaction at the solid/liquid interface.

In this study, the original tourmaline and beryl mineral samples have been collected from a Brazilian pegmatite. The objective of this study was to examine the adsorption behavior of uranyl from aqueous solution on Brazilian cyclosilicate samples. The cyclosilicate samples were characterized by elemental analysis, X-ray diffraction, and nitrogen adsorption–desorption. The ability of these minerals to remove the U(VI) from aqueous solution was followed by a series of adsorption isotherms, using a batchwise process. The adsorption maximum was determined to be 2.95 and 2.60 × 10 − 4 mol g − 1 for beryl and tourmaline mineral samples, respectively. The energetic effects caused by radionuclide cation adsorption were determined through calorimetric titrations. Thermodynamics indicated the existence of favorable conditions for such U(VI)–OH interactions.

Imogolite is an important paracrystalline hydrous aluminosilicate with a unique nanofiber structure. The synthetic imogolite sample was used for organofunctionalization process with 2-mercaptothiazoline and 2-mercaptobenzimidazole. Due to the increment of basic centers attached to the pendant chains, the metal adsorption capability of the final chelating materials, was found to be higher than is precursor. The ability of these materials to remove rubidium from aqueous solution was followed by a series of adsorption isotherms at room temperature and pH 4.0, in batch adsorption experiments in order to explain the adsorption mechanism. The maximum number of moles adsorbed was determined to be 17.89 × 10 −2 , 29.89 × 10 −2 , and 30.55 × 10 −2 mmol g −1 for IMO, IMO MBI , and IMO MTZ , respectively. In order to evaluate the aluminosilicate samples as adsorbents in dynamic system, a glass column was fulfilled with aluminosilicate samples (1.0 g) and it was fed with 1.9 × 10 −3 mol dm −3 rubidium at pH 4.0. The energetic effects caused by metal cations adsorption were determined through calorimetric titrations. The enthalpic and entropic values indicated the existence of favorable reaction between rubidium-nitrogen and sulfur center atoms on pendant chain covalent bonded to the inorganic backbone.

Investigations on diffusion in systems with memory [I.V.L. Costa, R. Morgado, M.V.B.T. Lima, F.A. Oliveira, Europhys. Lett. 63 (2003) 173] have established a hierarchical connection between mixing, ergodicity, and the fluctuation-dissipation theorem (FDT). This hierarchy means that ergodicity is a necessary condition for the validity of the FDT, and mixing is a necessary condition for ergodicity. In this work, we compare those results with recent investigations using the Lee recurrence relations method [M.H. Lee, Phys. Rev. B 26 (1982) 2547; M.H. Lee, Phys. Rev. Lett. 87 (2001) 250601; M.H. Lee, J. Phys. A: Math. Gen. 39 (2006) 4651]. Lee shows that ergodicity is violated in the dynamics of the electron gas [M.H. Lee, J. Phys. A: Math. Gen. 39 (2006) 4651]. This reinforces both works and implies that the results of [I.V.L. Costa, R. Morgado, M.V.B.T. Lima, F.A. Oliveira, Europhys. Lett. 63 (2003) 173] are more general than the framework in which they were obtained. Some applications to slow relaxation phenomena are discussed., Comment: 6 pages, 1 figure. Corrected last citation. Proceedings of LAWNP05

Os autores relatam um caso de osteoartropatia hipertrófica do tipo primária em paciente de 29 anos de idade, com dores articulares e aumento de volume das extremidades há 15 anos. Ao exame físico apresentava baqueteamento dos dedos e unhas em "vidro de relógio". A osteoartropatia hipertrófica foi considerada como primária porque foram excluídas todas as causas da forma secundária. As principais alterações radiológicas foram: espessamento das camadas corticais dos ossos tubulares e reação periosteal contínua do tipo lamelar. Não foram notadas alterações dos espaços articulares.

Os autores relatam um caso de osteoartropatia hipertrófica do tipo primária em paciente de 29 anos de idade, com dores articulares e aumento de volume das extremidades há 15 anos. Ao exame físico apresentava baqueteamento dos dedos e unhas em "vidro de relógio". A osteoartropatia hipertrófica foi considerada como primária porque foram excluídas todas as causas da forma secundária. As principais alterações radiológicas foram: espessamento das camadas corticais dos ossos tubulares e reação periosteal contínua do tipo lamelar. Não foram notadas alterações dos espaços articulares.The authors report a case of primary hypertrophic osteoarthropathy in a 29-year-old male with swollen joints. Physical examination revealed also digital clubbing and convexity of the nails. All other causes of secondary forms of hypertrophic osteoarthropathy were excluded. The main radiological abnormalities found were bone cortical hypertrophy and periosteal proliferation. Abnormalities of the joint spaces were not observed.

A realistic model of a doped quantum well heterostructure exhibits a subharmonic signal in the presence of intense far-infrared radiation. Nonlinearity enters the model through the effective potential due to the density of the electrons in the well. Driven at twice the resonant frequency of a ``bare'' two-level system the electron states undergo a subcritical pitchfork bifurcation. The signature of this nonlinear bifurcation is an emitted subharmonic radiation at half of the frequency of the drive. This nonperturbative response is found by applying the technique of averaging from nonlinear dynamical systems theory to the density matrix dynamical equations, for a many-body two-level system of electrons confined in the asymmetric square well, of Galdrikian and Birnir [Phys. Rev. Lett. 29, 3308 (1996)]. The averaged equations determine the parameter ranges of the subharmonic response and they turn out to be well within the capabilities of present quantum well technology and occur at moderate values of field strength of the drive. Potential technological applications of subharmonic generation include frequency conversion and the production of ``squeezed'' states of THz radiation.