Iron supply for erythropoiesis in the rabbit

Marrow radioiron uptake and marrow blood flow were measured in order to evaluate iron supply for erythropoiesis. Normal, phenylhydrazine-treated and bled animals were studied. The plasma iron turnover of seven normal rabbits was 1.49 +/- 0.22 mg/dl whole blood per d, of 11 rabbits treated 4 d before with phenylhydrazine was 5.16 +/- 1.81, and of four bled animals the plasma iron turnover was 3.75 +/- 1.61. The cardiac output and the percentage of blood flow to the marrow was increased in phenylhydrazine-treated and bled animals. Marrow iron flow in phenylhydrazine-treated animals was 38.3 +/- 32.6 micrograms/min per kg as compared with control values of 7.0 +/- 1.3 (P less than 0.01). This was due to an increase in marrow flow, an increase in plasma iron, and an increase in plasmatocrit. In bled animals, in spite of an increased marrow blood flow, marrow iron flow of 7.3 +/- 2.2 was similar to that of control animals due to a lower plasma iron concentration. The calculated marrow iron extraction of 3.7 +/- 2.4% in phenylhydrazine-treated animals was not different from that of control animals of 4.3 +/- 1.1, whereas extraction was increased in bled animals to 7.9 +/- 1.3 (P less than 0.01). In additional studies of transfused animals, acutely induced anemia was associated with an increased cardiac output, but also with a relative decrease in marrow flow, which left marrow iron supply unaffected. It would appear from these studies that an important mechanism for meeting the increased iron requirement of the hyperplastic erythroid marrow is an increase in marrow blood flow.

Estudio de la extracción química del fe en madera arqueológica subacuatica tratada previamente con peg 4000

Debido a la gran cantidad de muestras arqueológicas impregnadas con PEG que se encuentran contaminadas por compuestos insolubles de hierro, se plantea la posible extracción y formación de complejos Fe-L (L=PBTC) y sus efectos en (i) la estructura de la matriz orgánica, (ii) la estructura y propiedades físicas del PEG y (iii) el comportamiento de la muestra en la etapa posterior de almacenamiento. El proyecto analiza la formación de compuestos químicos y posibles modificaciones estructurales en el proceso de extracción del hierro. Consiste en un estudio sistemático de un sistema químico y su influencia en los procesos de precipitación de Fe3+ en medio acuoso. El proyecto se fundamenta en: (1) desarrollar un proceso experimental de optimización para la extracción de las sales contaminantes y (2) encontrar las técnicas analíticas óptimas que permitan apreciar modificaciones estructurales de los diferentes sistemas. Se determina la cantidad de hierro extraído mediante A.A. Las interacciones entre PBTC y PEG se analizan por IR. Las modificaciones de determinadas propiedades físicas se determinan por DSC y las estructurales mediante SEM. En las condiciones termodinámicas óptimas se obtiene una extracción superficial del hierro (30-35%). La disolución del PEG origina modificaciones de la masa y el volumen de la muestra

In vivo assessment of myelination by phase imaging at high magnetic field.

The present study evaluated the potential of using the phase of T2* weighted MR images to characterize myelination during brain development and pathology in rodents at 9.4 T. Phase contrast correlated with myelin content assessed by histology and suggests that most contrast between white and cortical gray matter is modulated by myelin. Ex vivo experiments showed that gray-white matter phase contrast remains unchanged after iron extraction. In dysmyelinated shiverer mice, phase imaging correlated strongly with myelin staining, showing reduced contrast between white and gray matter when compared to healthy controls. We conclude that high-resolution phase images, acquired at high field, allow assessment of myelination and dysmyelination.

Extração de ferro de esmectita brasileira com emprego do método ditionito-citrato-bicarbonato

A natural clay from Campina Grande region (Paraíba, Brazil), with 8.57% of Fe2O3, was used to study the most appropriate condition to carry out the iron extraction, without altering the clay structure in a significant way. Samples were treated with the Dithionite-Citrate-Bicarbonate method (DCB) for 30 and 120 minutes (pH=9.1), and also with citric acid (pH=1.8; time=15min), at 75°C. Conductivity measurements, X-ray fluorescence, X-ray diffraction, energy-dispersive spectrometry, electron-diffraction with transmission electron microscopy and textural evaluation by nitrogen adsorption were done. The treatment in a basic medium was more selective for iron removal than in acid condition. The time of 30 minutes, with 1.6 g Na2S2O4/10 g clay, was the best condition for the iron extraction.

Influência da calcinação sobre a remoção de ferro da caulinita e ilita e seus efeitos sobre a acidez

Samples of natural clay composed by kaolinite, illite, goethite and quartz, were calcinated and submitted to lixiviation with citrate and chloridric acid in order to remove iron. Investigation due to extraction consequences was carried cut by analyzing its acid properties using ammonia gas as probe in infrared spectrophotometry analysis. The sample that were treated with citrate followed by acid lixiviation yield materials twice more acid than samples treated with acid only.

EXTRAÇÃO ASSISTIDA POR ULTRASSOM PARA DETERMINAÇÃO COLORIMÉTRICA DE FERRO EM SOLO: UMA COMPARAÇÃO COM ESPECTROMETRIA DE MASSA COM PLASMA INDUTIVAMENTE ACOPLADO

A simple procedure for ultrasound-assisted extraction and colorimetric determination of iron in soil samples was developed. The iron concentration in the analyzed samples was determined by the colorimetric method and the results compared with inductively coupled plasma mass spectrometry (ICP-MS). Fifteen soil samples were analyzed and the iron concentration results compared with those obtained by ICP-MS using microwave-assisted sample digestion. The proposed procedure showed good efficiency for iron extraction and the results obtained by colorimetric determination exhibited good agreement with ICP-MS. Moreover, ultrasound-assisted extraction and colorimetric determination is a simple, fast and low-cost procedure for application in routine analysis.

Estudio de la extracción química del fe en madera arqueológica subacuatica tratada previamente con peg 4000

Debido a la gran cantidad de muestras arqueológicas impregnadas con PEG que se encuentran contaminadas por compuestos insolubles de hierro, se plantea la posible extracción y formación de complejos Fe-L (L=PBTC) y sus efectos en (i) la estructura de la matriz orgánica, (ii) la estructura y propiedades físicas del PEG y (iii) el comportamiento de la muestra en la etapa posterior de almacenamiento. El proyecto analiza la formación de compuestos químicos y posibles modificaciones estructurales en el proceso de extracción del hierro. Consiste en un estudio sistemático de un sistema químico y su influencia en los procesos de precipitación de Fe3+ en medio acuoso. El proyecto se fundamenta en: (1) desarrollar un proceso experimental de optimización para la extracción de las sales contaminantes y (2) encontrar las técnicas analíticas óptimas que permitan apreciar modificaciones estructurales de los diferentes sistemas. Se determina la cantidad de hierro extraído mediante A.A. Las interacciones entre PBTC y PEG se analizan por IR. Las modificaciones de determinadas propiedades físicas se determinan por DSC y las estructurales mediante SEM. En las condiciones termodinámicas óptimas se obtiene una extracción superficial del hierro (30-35%). La disolución del PEG origina modificaciones de la masa y el volumen de la muestra

Vivienda obrera en Bilbao y el Bajo Nervión: las casas baratas, una nueva forma de alojamiento (1911-1936)

A finales del siglo XIX y principios del siglo XX la provincia de Vizcaya despuntó en el contexto internacional como importe centro extractor de mineral de hierro y como relevante foco productor siderometalúrgico. Las explotaciones mineras se adueñaron de los Montes de Triano y las fábricas conquistaron las márgenes del Río Nervión, arrastrando tras de sí una densa marea humana. Alojar a esa población se convirtió en una cuestión de primer orden. Paralelamente, las instituciones estatales desbordadas por problemas similares en otros puntos de la geografía española, idearon y pusieron en práctica un complejo engranaje administrativo para erigir las primeras viviendas sociales. Así, las denominadas Casas Baratas fueron la respuesta oficial a la insuficiencia de vivienda obrera y Vizcaya fue una de las provincias donde mayor desarrollo tuvieron este tipo de propuestas constructivas. De este modo, la presente investigación comienza indagando sobre el origen de la problemática en Bilbao y la Cuenca del Bajo Nervión, para después repasar las medidas adoptadas por el Estado y la Diputación de Vizcaya en esta materia. Hecho esto, se da paso a un concienzudo repaso de las características principales de la edificación de Casas Baratas en toda la provincia de Vizcaya, descendiendo, posteriormente, a la realidad de Bilbao, Baracaldo, Sestao, Portugalete, Guecho y Erandio, haciendo hincapié en las inquietudes locales. El estudio finaliza con un ejercicio comparativo con las Casas Baratas de Barcelona, Sabadell y Tarrasa, estableciéndose similitudes y divergencias con el foco industrial más importante del momento en el panorama nacional.

Extração de ferro da cera de carnaúba utilizando sistemas microemulsionados

The constant search for biodegradable materials for applications in several fields shows that carnauba wax can be a viable alternative in the manufacturing of biolubricants. Carnauba wax is the unique among the natural waxes to have a combination of properties of great importance. In previous studies it was verified the presence of metals in wax composition that can harm the oxidative stability of lubricants. Considering these factors, it was decided to develop a research to evaluate iron removal from carnauba wax, using microemulsion systems (Me) and perform the optimization of parameters, such as: extraction pH, temperature, extraction time, among others. Iron concentration was determined by atomic absorption and, to perform this analysis, sample digestion in microwave oven was used, showing that this process was very efficient. It was performed some analysis in order to characterize the wax sample, such as: attenuated total reflectance infrared spectroscopy (ATR-IR), thermogravimetry (TG), differential scanning calorimetry (DSC), energy dispersive X-ray fluorescence (EDXRF), scanning electron microscopy (SEM) and melting point (FP). The microemulsion systems were composed by: coconut oil as surfactant, n-butanol as cosurfactant, kerosene and/or heptanes as oil phase, distilled water as water phase. The pH chosen for this study was 4.5 and the metal extraction was performed in finite experiments. To evaluate Me extraction it was performed a factorial design for systems with heptane and kerosene as oil phase, also investigating the influence of temperature time and wax/Me ratio, that showed an statistically significant answer for iron extraction at 95% confidence level. The best result was obtained at 60°C, 10 hours contact time and 1: 10 wax/Me ratio, in both systems with kerosene and heptanes as oil phase. The best extraction occurred with kerosene as oil phase, with 54% iron removal

Reciclagem de resíduos eletroeletrônicos: um estudo cinético da lixiviação ácida de ferro de placas de circuito impresso de microcomputadores.

O aumento no consumo mundial de novos aparelhos eletroeletrônicos aliado à redução no tempo de vida útil destes equipamentos tem como principal consequência ao meio ambiente a geração de resíduos. No Brasil, com a instituição da Política Nacional de Resíduos Sólidos, criou-se a obrigatoriedade legal da responsabilidade dos fabricantes pela logística reversa dos equipamentos eletroeletrônicos, incentivando pesquisas para o desenvolvimento dos métodos de reciclagem e tratamento dos materiais descartados. O processo de lixiviação foi avaliado como alternativa à etapa de separação magnética presente nas atuais rotas hidrometalúrgicas para recuperação de metais valiosos de placas de circuito impresso. Para avaliar a composição das placas, foi realizado ensaio de dissolução em água régia. As amostras foram moídas e submetidas a ensaios de lixiviação com ácido sulfúrico nas concentrações de 1 e 2mol/L, às temperaturas de 75ºC, 85ºC e 95ºC, durante 24 horas. Com ácido sulfúrico 2mol/L a 95ºC, o tempo necessário para se obter 100% de extração do ferro foi de 2 horas. Nestas condições, não foi detectada a presença de cobre dissolvido. A cinética da reação é controlada por reação química e obedece a equação .=1(1)3. A energia de ativação aparente do processo equivale a 90kJ/mol.

Solid phase extraction of iron and lead in environmental matrices on amberlite xad-1180/pv

A solid phase extraction procedure using Amberlite XAD-1180/Pyrocatechol violet (PV) chelating resin for the determination of iron and lead ions in various environmental samples was established. The procedure is based on the sorption of lead(II) and iron(III) ions onto the resin at pH 9, followed by elution with 1 mol/L HNO3 and determination by flame atomic absorption spectrometry. The influence of alkaline, earth alkaline and some transition metals, as interferents, are discussed. The recoveries for the spiked analytes were greater than 95%. The detection limits for lead and iron by FAAS were 0.37 µg/L and 0.20 µg/L, respectively. Validation of the method described here was performed by using three certified reference materials (SRM 1515 Apple Leaves, SRM 2711 Montana Soil and NRCC-SLRS-4 Riverine Water). The procedure was successfully applied to natural waters and human hair.

Preconcentration, determination and speciation of iron by solid-phase extraction using dimethyl (E)-2-[(Z)-1-acetyl)-2-hydroxy-1-propenyl]-2-butenedioate

A new sensitive and selective procedure for speciation of trace dissolved Fe(III) and Fe(II), using modified octadecyl silica membrane disks and determination by flame atomic absorption spectrometry was developed. A ML3 complex is formed between the ligand and Fe(III) responsible for extraction of metal ion on the disk. Various factors influencing the separation of iron were investigated and the optimized operation conditions were established. Under optimum conditions, an enrichment factor of 166 was obtained for Fe3+ ions. The calibration graph using the preconcentration system for Fe3+ was linear between 40.0 and 1000.0 μg L-1.

Iron determination by FAAS in fish feed and feces after ultrasound-assisted extraction

This paper proposes a method to determine iron in samples of fish feed and feces using ultrasound in the extraction of the analyte and in subsequent quantification by flame atomic absorption spectrometry. Using HCl 0.10 mol L -1 as the extraction solution, the optimal conditions of extraction were found to be: granulometry of the sample <60 μm; a sonication time of five cycles of 10 s and sonication power of 136 W. The method was applied in studies of the availability of iron in four food sources used in the diet of Nile Tilapia. The results obtained with the proposed extraction method allowed us to calculate the coefficients of apparent digestibility of iron in the food sources, which was not possible when using results obtained from samples mineralized by acid digestion. © Springer Science+Business Media, LLC 2008.

Study of ceramic block manufacture with the addition of waste from iron ore extraction

This work is intended to study the possibility of adding an amount of waste from iron mining in the ceramic mass. Clay and coal, from Vale do Paraiba, Sao Paulo, Brazil, were used in this research. These raw materials are used in the ceramic block manufacture. Clay and waste were analyzed by X-ray fluorescence and X-ray diffraction, particle size, differential thermal and thermogravimetric analysis. Liquid limit and plasticity index tests were performed in order to determine the amount of waste that which should be used in the ceramic mass. After determining the amount of waste, all samples were uniaxially pressed and sintered at 900 degrees C. Surface roughness measurements, apparent porosity and bulk density technique and three-point flexural tests were also performed to characterize the samples. The results showed that by adding the exact amount of waste, which was determined by the essays, it is possible to manufacture solid bricks.