Preparation and characterization of Cd(2)Nb(2)O(7) thin films on Si substrates

Thin Cd(2)Nb(2)O(7) films were grown on single-crystal p-type SiO(2)/Si substrates by the metallo-organic decomposition (MOD) technique. The films were investigated by X-ray diffraction, X-ray energy-dispersive spectroscopy, and field emission scanning electron microscopy, and showed a single phase (cubic pyrochlore), a crack-free spherical grain structure, and nanoparticles with a mean size of about 68 nm. A Cauchy model was also used in order to obtain the thickness and index of refraction of the stack layers (transparent layer/SiO(2)/Si) by spectroscopic ellipsometry (SE). The dielectric constant (K) of the films was calculated to be about 25 from the capacitance-voltage (C-V) measurements. (c) 2008 Elsevier Ltd. All rights reserved.

Isolation of a lectin and a galactoxyloglucan from Mucuna sloanei seeds

A lectin and a galactoxyloglucan were characterized from Mucuna sloanei seed cotyledons. The galactoxyloglucan, isolated by water extraction and ethanol precipitation, had Glc:Xyl:Gal proportions in a molar ratio of 1.8:1.7:1.0 and a molar mass (M(w)) of 1.6 x 10(6) g mol(-1). The lectin (sloanin), isolated from the same seed by affinity chromatography on cross-linked Adenanthera pavonina galactomannan, gave two protein bands by SDS-PAGE (36 and 34 kDa) and one peak by gel filtration (63.6 kDa). Its N-terminal sequence indicated similar to 69% identity with soybean agglutinin to leguminous lectins. Circular dichroism (CD) spectra established that sloanin predominantly contains beta-sheet structures. Sloanin has similar to 5.5% carbohydrate and displayed hemagglutinating activity against rabbit and enzyme treated human erythrocytes, inhibited only by D-Gal containing sugars. The interaction between sloanin and storage cell-wall galactoxyloglucan was tested by affinity chromatography and fluorescence spectroscopy. (C) 2009 Elsevier Ltd. All rights reserved.

Combined Crystallographic and Solution Molecular Dynamics Study of Allosteric Effects in Ester and Ketone p-tert-Butylcalix[4]arene Derivatives and Their Complexes with Acetonitrile, Cd(II), and Pb(II)

We describe here a procedure to bridge the gap in the field of calixarene physicochemistry between solid-state atomic-resolution structural information and the liquid-state low-resolution thermodynamics and spectroscopic data. We use MD simulations to study the kinetics and energetics involved in the complexation of lower rim calix[4]arene derivatives (L), containing bidentate ester (1) and ketone (2) pendant groups, with acetonitrile molecule (MeCN) and Cd2+ and Pb2+ ions (M2+) in acetonitrile solution. On one hand, we found that the prior inclusion of MeCN into the calix to form a L(MeCN) adduct has only a weak effect in preorganizing the hydrophilic cavity toward metal ion binding. On the other hand, the strong ion-hydrophilic cavity interaction produces a wide open calix which enhances the binding of one MeCN molecule (allosteric effect) to stabilize the whole (M2+)1(MeCN) bifunctional complex. We reach two major conclusions: (i) the MD results for the (M2+)1(MeCN) binding are in close agreement with the ""endo"", fully encapsulated, metal complex found by X-ray diffraction and in vacuo MD calculations, and (ii) the MD structure for the more flexible 2 ligand, however, differs from the also endo solid-state molecule. In fact, it shows strong solvation effects at the calixarene lower bore by competing MeCN molecules that share the metal coordination sphere with the four C=O oxygens of an ""exo"" (M2+)2(MeCN) complex.

Synthesis, characterization, and single crystal X-ray structure of the 1-furoyl-3-cyclohexylthiourea cadmium chloride complex, Cd[C4H3OC(O)NHC(S)NHC6H11]4Cl2

Cadmium chloride complex of 1-furoyl-3-cyclohexylthiourea (CyTu) was prepared and characterized by elemental analysis, IR, and Raman spectroscopy. The structure of the complex was determined by single crystal X-ray methods (space group Bbab, a = 20.918(1), b = 23.532(1), c = 23.571(1) angstrom, = = , Z = 8). Each cadmium has distorted octahedral geometry, coordinated by two chlorides and the thiocarbonyl sulfurs from four CyTu molecules. All the spectroscopic data are consistent with coordination of CyTu by sulfur to cadmium.

Pinguino In-bearing polymetallic vein deposit, Deseado Massif, Patagonia, Argentina: characteristics of mineralization and ore-forming fluids

The Pinguino deposit, located in the low sulfidation epithermal metallogenetical province of the Deseado Massif, Patagonia, Argentina, represents a distinct deposit type in the region. It evolved through two different mineralization events: an early In-bearing polymetallic event that introduced In, Zn, Pb, Ag, Cd, Au, As, Cu, Sn, W and Bi represented by complex sulfide mineralogy, and a late Ag-Au quartz-rich vein type that crosscut and overprints the early polymetallic mineralization. The indium-bearing polymetallic mineralization developed in three stages: an early Cu-Au-In-As-Sn-W-Bi stage (Ps(1)), a Zn-Pb-Ag-In-Cd-Sb stage (Ps(2)) and a late Zn-In-Cd (Ps(3)). Indium concentrations in the polymetallic veins show a wide range (3.4 to 1,184 ppm In). The highest indium values (up to 1,184 ppm) relate to the Ps(2) mineralization stage, and are associated with Fe-rich sphalerites, although significant In enrichment (up to 159 ppm) is also present in the Ps(1) paragenesis associated with Sn-minerals (ferrokesterite and cassiterite). The hydrothermal alteration associated with the polymetallic mineralization is characterized by advanced argillic alteration within the immediate vein zone, and sericitic alteration enveloping the vein zone. Fluid inclusion studies indicate homogenisation temperatures of 308.2-327A degrees C for Ps(1) and 255-312.4A degrees C for Ps(2), and low to moderate salinities (2 to 5 eq.wt.% NaCl and 4 to 9 eq.wt.% NaCl, respectively). delta(34)S values of sulfide minerals (+0.76aEuro degrees to +3.61aEuro degrees) indicate a possible magmatic source for the sulfur in the polymetallic mineralization while Pb isotope ratios for the sulfides and magmatic rocks ((206)Pb/(204)Pb, (207)Pb/(204)Pb and (208)Pb/(204)Pb ratios of 17.379 to 18.502; 15.588 to 15.730 and 38.234 to 38.756, respectively) are consistent with the possibility that the Pb reservoirs for both had the same crustal source. Spatial relationships, hydrothermal alteration styles, S and Pb isotopic data suggest a probable genetic relation between the polymetallic mineralization and dioritic intrusions that could have been the source of metals and hydrothermal fluids. Mineralization paragenesis, alteration mineralogy, geochemical signatures, fluid inclusion data and isotopic data, confirm that the In-bearing polymetallic mineralization from Pinguino deposit is a distinct type, in comparison with the well-known epithermal low sulfidation mineralization from the Deseado Massif.

Superoxide radical protects liposome-contained cytochrome c against oxidative damage promoted by peroxynitrite and free radicals

The effects of nitrosative species on cyt c structure and peroxidase activity were investigated here in the presence of O(2)(center dot-) and anionic and zwitterionic vesicles. Nitrosative species were generated by 3-morpholinesydnonymine (SIN1) decomposition, using cyt c heme iron and/or molecular oxygen as electron acceptor. Far-and near-UV CD spectra of SIN1-treated cyt c revealed respectively a slight decrease of a-helix content (from 39 to 34%) and changes in the tryptophan structure accompanied by increased fluorescence. The Soret CD spectra displayed a significant decrease of the positive signal at 403 nm. EPR spectra revealed the presence of a low-spin cyt c form (S = 1/2) with g(1) = 2.736, g(2) = 2.465, and g(3) = 2.058 after incubation with SIN1. These data suggest that the concomitant presence of NO(center dot) and O(2)(center dot-) generated from dissolved oxygen, in a system containing cyt c and liposomes, promotes chemical and conformational modi. cations in cyt c, resulting in a hypothetical bis-histidine hexacoordinated heme iron. We also show that, paradoxically, O(2)(center dot-) prevents not only membrane lipoperoxidation by peroxide-derived radicals but also oxidation of cyt c itself due to the ability of O(2)(center dot-) to reduce heme iron. Finally, lipoperoxidation measurements showed that, although it is a more efficient peroxidase, SIN1-treated cyt c is not more effective than native cyt c in promoting damage to anionic liposomes in the presence of tert-ButylOOH, probably due to loss of affinity with negatively charged lipids. (C) 2009 Elsevier Inc. All rights reserved.

Fabrication of disposable voltammetric electronic tongues by using Prussian Blue films electrodeposited onto CD-R gold surfaces and recognition of milk adulteration

A new approach to fabricate a disposable electronic tongue is reported. The fabrication of the disposable sensor aimed the integration of all electrodes necessary for measurement in the same device. The disposable device was constructed with gold CD-R and copper sheets substrates and the sensing elements were gold, copper and a gold surface modified with a layer of Prussian Blue. The relative standard deviation for signals obtained from 20 different disposable gold and 10 different disposable copper electrodes was below 3.5%. The performance, electrode materials and the capability of the device to differentiate samples were evaluated for taste substances model, milk with different pasteurization processes (homogenized/pasteurized, ultra high temperature (UHT) pasteurized and UHT pasteurized with low fat content) and adulterated with hydrogen peroxide. In all analysed cases, a good separation between different samples was noticed in the score plots obtained from the principal component analysis (PCA). Crown Copyright (C) 2008 Published by Elsevier B.V. All rights reserved.

Synthesis and characterization of stable Co and Cd doped nickel hydroxide nanoparticles for electrochemical applications

The present paper describes the physical-chemical characterization and electrochemical behavior of a new nanomaterial formed by the addition of cadmium and cobalt atoms into the structure of nickel hydroxide nanoparticles, these ones synthesized by an easy sonochemical method. Particles of about 5 nm diameter were obtained and characterized by high resolution transmission electron microscopy (HRTEM), X-ray diffraction and Raman spectroscopy. Different nickel hydroxide nanoparticles were immobilized onto transparent conducting substrates by using electrostatic layer-by-layer providing thin films at the nanoscale and the electrochemical behavior was investigated. The formation of a mixed hydroxide was corroborated by observation of very interesting properties as redox potential shifting to less positive potentials and high stability when submitted to long electrochemical cycling or high times of ultrasonic synthesis, suggesting practical applications. (C) 2008 Elsevier B.V. All rights reserved.

Removal of Zn(2+) from Electroplating Wastewater Using Modified Wood Sawdust and Sugarcane Bagasse

This paper describes the preparation of new adsorbents derived from sugarcane bagasse and wood sawdust (Manilkara sp.) to remove zinc (II) ions from electroplating wastewater. The first part deals with the chemical modification of sugarcane bagasse and wood sawdust, using succinic anhydride to introduce carboxylic acid functions into the material. The obtained materials (modified sugarcane bagasse MB2 and modified wood sawdust MS2) were then characterized by infrared spectroscopy (IR) and used in adsorption experiments. The adsorption experiments evaluates Zn(2+) removal from aqueous single metal solution and real electroplating wastewater on both batch and continuous experiments using fixed-bed columns prepared in laboratorial scale with the obtained adsorbents. Adsorption isotherms were then developed using Langmuir model and the Thomas kinetic model. The calculated Zn(2+) adsorption capacities were found to be 145 mg/g for MS2 and 125 mg/g for MB2 in single metal aqueous solution, whereas for the industrial wastewater these values were 61 mg/g for MS2 and 55 mg/g for MB2.

Framtiden för CD-skivan som musikformat : En undersökning av CD-formatets roll på musikmarknaden

Sedan början på 2000-talet har försäljningssiffrorna för CD-skivan inom musikindustrin varit på nedgång och minskat årligen, samtidigt som de nya digitala formaten har etablerats på den globala marknaden. Men trots många spekulationer, där CD-skivan sedan år tillbaka har stämplats som ett döende musikmedium, tyder försäljningsstatistiken på att CD:n och andra fysiska format fortfarande har en plats på den moderna globala musikmarknaden. I denna undersökning sammanställs försäljningssiffror från världens största musikmarknader, samt Sverige, för att få en tydligare överblick över hur försäljningsfördelningen egentligen ser ut mellan de olika musikformaten. Genom sekundäranalys, kombinerat med Boltanski och Thénevots teori om de olika typer av världar som existerar i vardagen, och deras respektive värdeordningar, analyseras den insamlade datan för att få en ökad förståelse för varför försäljningsfördelningen ser ut som den gör idag, och hur utvecklingen har sett ut under föregående år. Resultatet visar att den globala försäljningsfördelningen under 2014 var jämnt fördelad mellan digitala och fysiska format, med en andel på cirka 46% vardera av den totala globala musikmarknaden. Detta visar att fysiska format, trots en årlig minskning, år 2014 hade en roll på musikmarknaden som, ur försäljningsaspekt, var likvärdig digitala format, och CD-skivan (och även vinylen) kan därför inte ännu anses vara död.

November 1994: CD-ROMs, Gopher: Freshman Research Habit; Archives Traveling Exhibit

Inside this Issue: Freshman ResearchScholarly CommunicationTraveling ExhibitActive PeopleIntroducing

Uma proposta de modelo para avaliação de websites de comércio eletrônico: aplicação ao varejo de CD'S

A dissertação tem como objeto a investigação das relações entre a o design de um website de comércio eletrônico de CDs e o comportamento do consumidor virtual, com ênfase a sua atitude e intenção de compra. O objetivo principal é mensurar o efeito do design da loja virtual (website) em seu papel de agente de vendas na Internet. A análise do comércio varejista de CDs foi escolhida, pois este produto é um dos principais artigos de venda neste canal. O estudo é apoiado em um referencial teórico, no qual são analisadas as características dos seguintes pontos: i) a Internet atuando como canal de vendas; ii) o comércio varejista de CD no Brasil e iii) o comportamento do consumidor e o seu processo decisório. Ainda no referencial teórico são apresentados os diversos modelos de avaliação de website existentes: baseado em Marketing, Teoria dos Dois Fatores, avaliação da qualidade, avaliação da web (W AM) e aceitação da Tecnologia na Web (T AM). A análise e comparação destes modelos serviu como base para o desenvolvimento da proposta do modelo de avaliação website. O estudo é complementado pelo desenvolvimento de uma pesquisa, com aplicação de questionário via web (websurvey). A coleta dos dados é utilizada como forma de validação estatística das relações existentes no modelo desenvolvido. Isto é feito por meio do uso da ferramenta de análise de Equações Estruturadas (SEM), suportada pelos conceitos e métodos de abordagem descritos no referencial teórico. A ferramenta permite tanto avaliar um modelo de mensuração e um modelo estrutural simultaneamente.

Quinze anos de ação comunitária: uma análise descritiva de uma prática educacional

Este estudo aborda a Ação Comunitária, forma de intervenção educacional em populações carentes, no período de 1950 a 1975. Avalia esta ação, baseando no binômio "Dependência-independência" , partindo do pressuposto que a Ação Comunitária, Dor definição, deve levar as populações-alvo à urna postura de independência para tornarem-se interdependentes na consecução do objetivo do desenvolvimento. o objeto principal do estudo é a evolução histórica de urna instituição particular, a FASE, comparada com outras instituições públicas e privadas, que atuaram nas comunidades ditas marginalizadas, na época analisada. Analisam-se as redefinições de objetivos da instituição e, posteriormente, reformulações das estratégias pedagógicas, usadas no decorrer destes anos, Dara definir três tipos básicos de intervenção: 1. O assistencialismo que, sem usar metodologia específica, atende as comunidades nas suas supostas necessidades, numa postura anti-pedagógica, porque aumenta com isso os laços de dependência da comunidade em relação à instituição interveniente. 2. O DC (desenvolvimento comunitário), metodologia propagada 4 nela 0NU na década de 60, baseada ora em técnicas de planejamento, ora em teorias sociais, e que pretende obter maior participação da comunidade na definição e implementação do seu auto desenvolvimento . Conclui-se que a experiência do De no Brasil, em geral falhou, não tanto por falta de continuidade, mas mais por conjunturas políticosociais adversas, falta de planeiamento global e superficialidade na condu~ão do processo, ficando o DC limitado à Or~ani ? ação da Comunidad e e algumas melhoria s de infra- estrutura hásica, obtidas através de estratéqias de auto-ajuda e mutirãô, sem nun ca atingir os problemas estruturais, causas da mar ginalizacão e da dependência. 3. A Educação oara o Desenvolvimento , ornoosta na d! cada de 70 7 ~ue se limitou em primeira instância a UM mera nualificação do capital humano , e, na medida no avanço da abertura oolítica, se redifi niu numa nedaqoqia de conscientização e oarticipa cao. Enquant~ a ~rimeira estratéqia educacional transfere a dependência do indivíduo ao ânbito do sistema capitalista, a segunda esbarra contra os nro~lemas estruturais s6cio-econômicos de um nais eM fase de caritalismo denendente. Conclui-se que a Acão Comunitária, nara alcancar seu objetivo que é a independência dos ind ivíduos e rlas comunidades, marginalizadas, nara tornarem-se narceiras i 9uais particioativos no orocesso de desenvolvimento nacionaL depende, basicamente , da conjuntura nolítica e das estruturas econômico- sociais do pais.