Sorption kinetics and intrapaticulate diffusivity of As(III) bioremediation from aqueous solution, using modified and unmodified coconut fiber

The pollution and toxicity problems posed by arsenic in the environment have long been established. Hence, the removal and recovery remedies have been sought, bearing in mind the efficiency, cost effectiveness and environmental friendliness of the methods employed. The sorption kinetics and intraparticulate diffusivity of As (III) bioremediation from aqueous solution using modified and unmodified coconut fiber was investigated. The amount adsorbed increased as time increased, reaching equilibrium at about 60 minutes. The kinetic studies showed that the sorption rates could be described by both pseudo-first order and pseudo-second order process with the later showing a better fit with a value of rate constant of 1.16 x 10-4 min-1 for the three adsorbent types. The mechanism of sorption was found to be particle diffusion controlled. The diffusion and boundary layer effects were also investigation. Therefore, the results show that coconut fiber, both modified and unmodified is an efficient sorbent for the removal of As (III) from industrial effluents with particle diffusion as the predominant mechanism.

Spectrophotometric study of the chromium(III)/azide system in the ultraviolet region and its analytical application

A sensitive and alternative method for the spectrophotometric determination of chromium(III) based on the formation of chromium(III)/azide complexes was established by investigating a new band in the ultraviolet region. The best experimental conditions for the analytical determination of this metallic ion were: ligand and perchloric acid analytical concentration = 493 and 12.0 mmol L-1, respectively; aqueous medium; T = 25.0 ºC; contact time = 1 hour. The maximum molar absorptivity coefficient occurred at 287 nm (average 1.481 ± 0.008 ´ 10(4) L mol-1 cm-1), leading to the determination of metal ion concentrations one hundred times lower than the ones formerly determined in the visible region. The system obeys Beer's Law and is suitable for chromium determination in the 0.702-2.81 mg L-1 concentration range (15-65% T, 1.00 cm-width quartz cells). Analytical applications of the current method were tested with a nutritional supplement containing chromium. Results were compared with those obtained with atomic absorption spectrometry.

Ascorbic acid determination using a carbon paste electrode modified with iron(III) ions adsorbed on humic acid

An amperometric sensor was constructed, by using humic acids to immobilize Fe3+ ions on a carbon paste electrode (CPE-HA-Fe), and used for ascorbic acid (H2A) determination. The cyclic voltammogram of the electrode showed electrochemical response due to the Fe3+/Fe2+ couple at E1/2=+0.78 V vs SCE, using 0.5 mol L-1 KCl and 0.2 mol L-1 acetate/0.020 mol L-1 phosphate buffer, at pH = 5.4, as supporting electrolyte. When H2A is added to the electrolyte solution it is observed an oxidation process. The oxidation current, obtained by chronoamperommetry at +0.87 V vs SCE, is proportional to the concentration, represented by the equation I(µA) = 7.6286 [H2A] (mmol L-1) + 1.9583, r = 0.9996, for concentrations between 0.0 and 1.4 mmol L-1. The electrode showed high stability and was used for H2A determination in a natural orange juice.

Melody III, Op. 17 N:o 3

Ei vapaa, vapautuu 2027. Kosti Vehanen (1887-1957).

Complexes of 3,4-dimethoxybenzoic acid anion with Cu(II), Co(II), La(III), and Nd(III)

Physico-chemical properties of 3,4-dimethoxybenzoates of Co(II), Cu(II), La(III) and Nd(III) were studied. The complexes were obtained as hydrated or anhydrous polycrystalline solids with a metal ion-ligand mole ratio of 1 : 2 for divalent ions and of 1 : 3 in the case of trivalent cations. Their colours depend on the kind of central ion: pink for Co(II) complex, blue for Cu(II), white for La(III) and violet for Nd(III) complexes. The carboxylate groups in these compounds are monodentate, bidentate bridging or chelating and tridentate ligands. Their thermal decomposition was studied in the range of 293-1173 K. Hydrated complexes lose crystallization water molecules in one step and form anhydrous compounds, that next decompose to the oxides of respective metals. 3,4 - Dimethoxybenzoates of Co(II) is directly decomposed to the appropriate oxide and that of Nd(III) is also ultimately decomposed to its oxide but with the intemediate formation of Nd2O2CO3.. The magnetic moment values of 3,4-dimethoxybenzoates determined in the range of 76-303 K change from 4.22 µB to 4.61 µB for Co(II) complex , from 0.49 µB to 1.17 µB for Cu(II) complex , and from 2.69 µB to 3.15 µB for Nd(III) complex.

Spectroscopic analysis of C80 doping with group III and group V elements using semiempirical PM3 molecular modelling technique

Semiempirical calculations at the level of PM3 of theory were carried out to study the structural and electronic properties of C80 and some of its doped derivatives with the elements of group III and V at the level of PM3 of theory. We have selected these elements to be substituted in the fullerene-C80 cage in order to show the effect of such structural change on the electronic properties of the molecules studied. The theoretical IR spectra, some of physical and chemical properties of the molecules studied are obtained and discussed.

Comparison of some properties of 2,3 - and 3,4 - dimethoxybenzoates of Cu(II), Co(II) and Nd(III)

The physicochemical properties of 2,4-, and 3,4- dimethoxybenzoates of Cu(II), Co(II) and Nd(III) were studied and compared to observe the -OCH3 substituent positions in benzene ring on the character of complexes. The analysed compounds are crystalline hydrated or anhydrous salts with colours depending on the kind of central ions: blue for Cu(II), pink for Co(II) and violet for Nd(III) complexes. The carboxylate groups bind as monodentate, bidentate bridging or chelating and even tridentate ligands. Their thermal stabilities were studied in air at 293-1173K. When heated the hydrated complexes release the water molecules and form anhydrous compounds which are then decomposed to the oxides of respective metals. Their magnetic moment values were determined in the range of 76-303K. The results reveal the compounds of Nd(III) and Co(II) to be the high-spin and that of Cu(II) forms dimer. The various positions of -OCH3 groups in benzene ring influence some of physicochemical properties of analysed compounds.

Synthesis and magnetic studies of copper(II)-lanthanide(III) 5-bromosalicylideneglycylglycine

The physico-chemical properties of the new 3d-4f heteronuclear complexes with general formula LnCu3(C11H8N2 O4Br)3·13H2O (where Ln = Pr, Eu, Gd, Tb, Er, Yb and H3(C11H8N2 O4Br) - 5-bromosalicylideneglycylglycine) were studied. The compounds were characterized by elemental, spectral and thermal analyses and magnetic measurements. The formation of Schiff base is evidenced by a strong band at ca. 1646-1650 cm-1 attributable to C=N stretching mode. The presence of water molecules is confirmed by broad absorptions with maximum at 3360 - 3368 cm-1. The Cu(II)-Ln(III) complexes are stable up to ca. 318 K. During dehydration process the water molecules are lost probably in two stages. The magnetic susceptibility data for these complexes change with temperature according to the Curie-Weiss law.

Complexes of 4-chlorophenoxyacetates of Nd(III), Gd(III) and Ho(III)

The complexes of 4-chlorophenoxyacetates of Nd(III), Gd(III) and Ho(III) have been synthesized as polycrystalline hydrated solids, and characterized by elemental analysis, spectroscopy, magnetic studies and also by X-ray diffraction and thermogravimetric measurements. The analysed complexes have the following colours: violet for Nd(III), white for Gd(III) and cream for Ho(III) compounds. The carboxylate groups bind as bidentate chelating (Ho) or bridging ligands (Nd, Gd). On heating to 1173K in air the complexes decompose in several steps. At first, they dehydrate in one step to form anhydrous salts, that next decompose to the oxides of respective metals. The gaseous products of their thermal decomposition in nitrogen were also determined and the magnetic susceptibilites were measured over the temperature range of 76-303K and the magnetic moments were calculated. The results show that 4-chlorophenoxyacetates of Nd(III), Gd(III) and Ho(III) are high-spin complexes with weak ligand fields. The solubility value in water at 293K for analysed 4-chlorophenoxyacetates is in the order of 10-4mol/dm³.

Synthesis and characterization of Fe(III)-doped ceramic membranes of titanium dioxide and its application in photoelectrocatalysis of a textile dye

Pure and Fe(III)-doped TiO2 suspensions were prepared by the sol gel method with the use of titanium isopropoxide (Ti(OPri)4) as precursor material. The properties of doped materials were compared to TiO2 properties based on the characterization by thermal analysis (TG-DTA and DSC), X-ray powder diffractometry and spectroscopy measurements (FTIR). Both undoped and doped TiO2 suspensions were used to coat metallic substrate as a mean to make thin-film electrodes. Thermal treatment of the precursors at 400ºC for 2 h in air resulted in the formation of nanocrystalline anatase TiO2. The thin-film electrodes were tested with respect to their photocatalytic performance for degradation of a textile dye in aqueous solution. The plain TiO2 remains as the best catalyst at the conditions used in this report.

A difícil arte de "deslizar sobre o mundo" ou Montaigne, um político discreto ("De poupar a própria vontade" - III, 10)

De 1581 a 1585, Montaigne foi prefeito de Bordeaux. Foi acusado por detratores de não se ter aplicado o bastante e de não ter feito nada de marcante durante seus dois mandatos. Ao responder às acusações no ensaio "De poupar a própria vontade" (III, 10), o autor encontra a ocasião para uma crítica das paixões em geral e, em particular, das que pertencem ao contexto político. Isto porque ele visava, com sua aparente falta de aplicação aos deveres de prefeito, evitar a paixão que tantas vezes se oculta por trás do engajamento - a ambição, desejo de honras, glória, renome. Sobretudo, esperava evitar um duplo perigo, ao mesmo tempo ético e político: comprometer a própria liberdade numa busca servil da glória e subordinar o bem coletivo ao interesse pessoal. No presente estudo, procuraremos reconstituir a trama argumentativa do ensaio em questão, acompanhando de perto os argumentos que sustentam a crítica montaigniana das paixões, bem como a terapia muito particular a que o ensaísta as submete, a qual lhe permite fazer do episódio da Mairie de Bordeaux um modelo de conciliação entre o cuidado de si e o cumprimento dos deveres políticos.

Pianokonsertto III op. 46 (1981) : Pianokonsert III op. 46 (1981) = Piano Concerto III op. 46 (1981)

Soitinnus: piano, orkesteri.

Relato de Rhizoctonia solani AG-4 HG I em crisântemo (Papiro Branco e Amarelo) e R. solani AG-4 HG III em gipsófila no estado de São Paulo, Brasil, e sua patogenicidade cruzada

Atualmente, grupamento de anastomose (AG) de Rhizoctonia sp. em crisântemo e ocorrência deste fungo em gipsófila ainda não foram relatados no Brasil. Assim, realizou-se teste de patogenicidade normal e cruzada e sequenciamento da região ITS-5.8S rDNA para identificar o AG de isolado obtido de plantas de crisântemo (Papiro Branco) e de gipsófila, ambas originárias de Holambra / São Paulo, Brasil. Após os testes, relata-se pela primeira vez a ocorrência de R. solani AG-4 HG I em crisântemo (Papiro Branco e Amarelo) e R. solani AG-4 HG III em gipsófila, no estado de São Paulo, Brasil, e, também, a sua patogenicidade cruzada.

Basel III -vakavaraisuuskehikon vaikutus investointipankkiin ja sen luottoriskin hallintaan

Tutkielman tavoitteena oli analysoida Basel III -vakavaraisuuskehikon tuomia muutoksia ja niiden vaikutusta yksittäiseen investointipankkiin ja sen luottoriskin hallintaan. Tarkoituksena oli syventyä aiheeseen tarkastelemalla luottoriskin asemaa ja elementtejä, sekä pohtia Basel III -kehikon tuomia muutoksia Basel II -säännöstöön nähden. Empiirisessä osiossa tapaustutkimuksen aineistonkeruumenetelmänä käytettiin puolistrukturoitua haastattelua ja kohdeyrityksenä Evli Pankki Oyj:tä. Basel III -vakavaraisuuskehikon tarkoitus on vahvistaa pankkeja ja korjata sääntelyn puutteita, jotka tulivat esille finanssikriisissä 2007–2009. Luottoriski on pankkitoiminnan merkittävin riski ja sen hallinta on olennainen osa Basel III -kehikkoa. Basel III -säännöstön myötä pankeilla on oltava enemmän omia varoja suhteessa niiden riskipainotettuihin saamisiin. Lisäksi pankeille asetetaan uusia pääomapuskuri- ja maksuvalmiusvaatimuksia, sekä pankkien velkaantumista rajoitetaan uudella vähimmäisomavaraisuusasteella. Basel III -kehikon vaikutukset kohdeyritykseen jäävät vähäisiksi, koska kohdeyrityksen vakavaraisuus ja likviditeetti ovat erittäin hyvällä tasolla. Suurimmat vaikutukset kohdeyritykseen aiheutuvat maksuvalmiusvaatimuksesta (LCR) ja pysyvän varainhankinnan vaatimuksesta (NSFR).

Harvesting and wood transport planning with SNAP III program (Scheduling and Network Analysis Program) in a pine plantation in Southeast Brazil

The objective of this study was to verify the potential of SNAP III (Scheduling and Network Analysis Program) as a support tool for harvesting and wood transport planning in Brazil harvesting subsystem definition and establishment of a compatible route were assessed. Initially, machine operational and production costs were determined in seven subsystems for the study area, and quality indexes, construction and maintenance costs of forest roads were obtained and used as SNAP III program input data. The results showed, that three categories of forest road occurrence were observed in the study area: main, secondary and tertiary which, based on quality index, allowed a medium vehicle speed of about 41, 30 and 24 km/hours and a construction cost of about US$ 5,084.30, US$ 2,275.28 and US$ 1,650.00/km, respectively. The SNAP III program used as a support tool for the planning, was found to have a high potential tool in the harvesting and wood transport planning. The program was capable of defining efficiently, the harvesting subsystem on technical and economical basis, the best wood transport route and the forest road to be used in each period of the horizon planning.