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Teores de cloretos, lactose e índice cloretos/lactose na secreção láctea de bovinos da raça Jersey no primeiro mês da lactação; Chloride and lactose contents and chloride/lactose ratio in milk from Jersey cows in the first month of lactation

RAIMONDO, R. F. S; BIRGEL, Daniela Becker; SAUT, João Paulo Elsen; KOMNINOU, E. R; BIRGEL JÚNIOR, Eduardo Harry
Fonte: Belo Horizonte Publicador: Belo Horizonte
Tipo: Artigo de Revista Científica
Português
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36.75%
Avaliou-se a influência do período colostral nos teores lácteos de cloretos, lactose e do índice cloretos/lactose. Foram colhidas 418 amostras de leite provenientes de glândulas mamárias sadias, e que não apresentavam crescimento bacteriano ao exame microbiológico, de 127 vacas da raça Jersey. As amostras foram distribuídas em oito grupos: 0 ?1/2 dia; 1/2 ?1 dia; 1 ?2 dias; 2 ?3 dias; 3 ?5 dias; 5 ?7 dias; 7 ?15 dias; 15 ?30 dias em lactação. Nas amostras, colhidas antes da ordenha, foram determinados os valores de cloretos, por titulação colorimétrica, e de lactose, por radiação infravermelho, e calculou-se o índice cloretos/lactose. Nas primeiras 24 horas da lactação, observou-se abrupta diminuição no teor lácteo de cloretos e do índice cloretos/lactose, associada com o aumento no teor lácteo de lactose. A transição da secreção de colostro para leite em relação ao teor de cloretos e lactose e ao índice cloretos/lactose na secreção láctea ocorreu na primeira semana da lactação, a partir do terceiro dia da lactação para o valor de cloretos e para a relação cloretos/lactose e a partir do quarto dia da lactação para o teor de lactose. Recomenda-se, nas primeiras 24 horas da lactação, a adoção dos seguintes limites de normalidade: cloretos...

Model to predict the chloride penetration in concrete with profile forming peak: verification of its precision

GUIMARAES, A. T. C.; Helene, Paulo Roberto do Lago
Fonte: UNIV FED RIO DE JANEIRO, LAB HIDROGENIO Publicador: UNIV FED RIO DE JANEIRO, LAB HIDROGENIO
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
36.66%
Chloride attack in marine environments or in structures where deicing salts are used will not always show profiles with concentrations that decrease from the external surface to the interior of the concrete. Some profiles show an increase in chloride concentrations from when a peak is formed. This type of profile must be analyzed in a different way from the traditional model of Fick`s second law to generate more precise service life models. A model for forecasting the penetration of chloride ions as a function of time for profiles having formed a peak. To confirm the efficiency of this model, it is necessary to observe the behavior of a chloride profile with peak in a specific structure over a period of time. To achieve this, two chloride profiles with different ages (22 and 27 years) were extracted from the same structure. The profile obtained from the 22-year sample was used to estimate the chloride profile at 27 years using three models: a) the traditional model using Fick`s second law and extrapolating the value of C(S)-external surface chloride concentration; b) the traditional model using Fick`s second law and shifting the x-axis to the peak depth; c) the previously proposed model. The results from these models were compared with the actual profile measured in the 27-year sample and the results were analyzed. The model was presented with good precision for this study of case...

Micellar properties of surface active ionic liquids: A comparison of 1-hexadecyl-3-methylimidazolium chloride with structurally related cationic surfactants

GALGANO, Paula D.; SEOUD, Omar A. El
Fonte: ACADEMIC PRESS INC ELSEVIER SCIENCE Publicador: ACADEMIC PRESS INC ELSEVIER SCIENCE
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
36.66%
Ionic liquids, ILs, carrying long-chain alkyl groups are surface active, SAIIs. We investigated the micellar properties of the SAIL 1-hexadecyl-3-methylimidazolium chloride, C(16)MeImCl, and compared the data with 1-hexadecylpyridinium chloride, C(16)PYCl, and benzyl (3-hexadecanoylaminoethyl)dimethylammonium chloride, C(15)AEtBzMe(2)Cl. The properties compared include critical micelle concentration, cmc; thermodynamic parameters of micellization; empirical polarity and water concentrations in the interfacial regions. In the temperature range from 15 to 75 degrees C, the order of cmc in H(2)O and in D(2)O is C(16)PYCl > C(16)MeImCl > C(15)AEtBzMe(2)Cl. The enthalpies of micellization, Delta H(mic)(degrees), were calculated indirectly from by use of the van`t Hoff treatment; directly by isothermal titration calorimetry, ITC. Calculation of the degree of counter-ion dissociation, alpha(mic), from conductivity measurements, by use of Evans equation requires knowledge of the aggregation numbers, N(agg), at different temperatures. We have introduced a reliable method for carrying out this calculation, based on the volume and length of the monomer, and the dependence of N(agg) on temperature. The N(agg) calculated for C(16)PyCl and C(16)MeImCl were corroborated by light scattering measurements. Conductivity- and ITC-based Delta H(mic)(degrees) do not agree; reasons for this discrepancy are discussed. Micelle formation is entropy driven: at all studied temperatures for C(16)MeImCl; only up to 65 degrees C for C(16)PyCl; and up to 55 degrees C for C(15)AEtBzMe(2)Cl. All these data can be rationalized by considering hydrogen-bonding between the head-ions of the monomers in the micellar aggregate. The empirical polarities and concentrations of interfacial water were found to be independent of the nature of the head-group. (C) 2010 Elsevier Inc. All rights reserved.; FAPESP (State of Sao Paulo Research Foundation); Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); CNPq (National Council for Scientific and Technological Research)

Influência dos íons cloreto na cinética de redução eletroquímica dos íons de Bi+3 e CU2+ no eletrodo de mercúrio; Influence of chloride ions on the electrochemical reduction of Bi3+ and Cu2+ ions on mercury electrode

Agostinho, Silvia Maria Leite
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 03/11/1975 Português
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A influência de pequenas concentrações de íons cloreto na cinética de redução eletroquímica dos íons Bi3+ e Cu2+ foi estudada através de medidas independentes de adsorção específica e de cinética eletroquímica. A adsorção específica foi determinada por meio das curvas eletrocapilares obtidas com o método do tempo de gota, para soluções aquosas de misturas de ácido clorídrico xM e de ácido perclórico (1 - x)M. Obeservou-se que, em concentrações de cloreto muito baixas, iguais ou inferiores a 10-2 M, a adsorção específica desses íons segue a isoterma de adsorção de Henry. A cinética da redução eletroquímica dos íons de Bi3+ e Cu2+, na presença de pequenas concentrações de íons cloreto, em meio de ácido perclórico 1 M, foi estudada por polarografia com o eletrodo de mercúrio. Os valores das constantes de velocidade foram calculados, a partir da relação existente entre a corrente, medida em cada potencial, e a corrente de difusão, usando as equações relativas a processos de eletrodos irreversíveis. Estes valores mostraram que, para as concentrações mais baixas de cloreto estudadas, esses íons aceleram as reações Bi3+ + 3e → Bi(Hg) e Cu2+ + 2e → Cu(Hg). O mecanismo de redução...

Histochemical technique for the detection of chloride cells in fish

Pereira, Bruno Fiorelini; Caetano, Flávio Henrique
Fonte: Pergamon-Elsevier B.V. Ltd Publicador: Pergamon-Elsevier B.V. Ltd
Tipo: Artigo de Revista Científica Formato: 783-786
Português
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Chloride cells are responsible for ionic exchanges in the fish gill. These cells have been widely studied. considering its importance in vital functions of the gill, and because they proliferate when exposed to unfavorable environments. one of the main characteristic of these cells is an acidic cytoplasm, which has been used for identification through histochemical techniques with dyes such as Toluidine Blue and Hematoxylin and Eosin. However, these techniques can be problematic, since epithelial cells can, in certain situations, acquire acidic characteristics similar to those of chloride cells, thus staining in a similar way. Among other functions, chloride cells play a role in calcium uptake from the environment, and therefore have a high concentration of this element. Based on this information, this study aims at developing a specific protocol for the identification of chloride cells. With this purpose, the Von Kossa method specific for calcium was used combined with Hematoxylin counterstaining. Chloride cells had cytoplasm slightly stained with Hematoxylin and the presence of dark stained granules dispersed in the cytoplasm resulted from the Von Kossa reaction due to the calcium present in these cells. This was not found in any other gill cell. Thus...

Possible effects of sodium chloride treatment on quality of effluents from Alabama channel Catfish ponds

Sipaúba Tavares, Lúcia H.; Boyd, Claude E.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 217-222
Português
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Channel catfish ponds are treated with salt (sodium chloride) to increase chloride concentration and prevent nitrite toxicity in fish. A survey indicated that most farmers try to maintain chloride concentration of 50 to 100 mg/L in ponds by annual salt applications. Averages and standard deviations for selected water quality variables in salt-treated ponds were as follows: chloride, 87.2 ± 37.5 mg/L; total dissolved solids (TDS), 336 ± 96 mg/L; specific conductance, 512 ± 164 μmhos/cm. Maximum values were 189 mg/L for chloride, 481 mg/L for TDS, and 825 μmhos/cm for specific conductance. Good correlations between specific conductance values and both chloride and TDS concentrations suggest that specific conductance can be a rapid method for estimating concentrations of these two variables in surface water. The maximum limit for chloride concentration in Alabama streams allowed by the Alabama Department of Environmental Management is 230 mg/L. The usual recommended upper limit of TDS for protection of aquatic life in freshwater streams is 1,000 mg/L. Based on the observed relationship between TDS concentration and specific conductance in Alabama catfish ponds, 1,000 mg/L TDS corresponds to 1,733 μmhos/cm specific conductance. It is unlikely that effluents from salt-treated catfish ponds would violate the in-stream chloride standard of 230 mg/L or harm aquatic life in streams. Nevertheless...

Evaluation of the bone healing process utilizing platelet-rich plasma activated by thrombin and calcium chloride: A histologic study in rabbit calvaria

Betoni-Junior, Walter; Dechichi, Paula; Esteves, Jônatas Caldeira; Zanetta-Barbosa, Darceny; Magalhães, Aparecido Eurípedes Onório
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 14-21
Português
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36.66%
To evaluate the bone healing of defects filled with particulate bone graft in combination with platelet-rich plasma (PRP), added with a mixture of calcium chloride and thrombin or just calcium chloride. Two 5-mm bone defects were created in the calvaria of 24 rabbits. Each defect was filled with particulate bone graft and PRP. In one defect the PRP was activated by a mixture of calcium chloride and thrombin; in the other, PRP was activated by calcium chloride only. The animals were euthanized 1, 2, 4, and 8 weeks after the surgeries, and the calvaria was submitted to histologic processing for histomorphometric analysis. The qualitative analysis has shown that both defects presented the same histologic characteristics so that a better organized, more mature, and well-vascularized bone tissue was noticed in the eighth week. A good bone repair was achieved using either the mixture of calcium chloride and thrombin or the calcium chloride alone as a restarting agent of the coagulation process.

Redução de cloreto de sódio e substituição de nitrito de sódio em produto cárneo embutido cozido : características físico-químicas, microbiológicas e sensoriais; Reduction of sodium chloride and replacement of sodium nitrite in stuffed cooke meat product : physical-chemical, microbiological and sensory characterisitics

Renata do Nascimento
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 02/08/2010 Português
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No desenvolvimento de produtos cárneos com apelos saudáveis, a redução de sódio e a substituição de nitrito de sódio são relevantes estratégias a serem implementadas pela indústria de processamento. Embora, já seja possível encontrar em alguns mercados produtos cárneos com redução de sódio, a produção desses itens com aceitação sensorial e desempenho tecnológico ainda é um grande desafio. Este trabalho tem o objetivo de avaliar a influência da redução de cloreto de sódio e a substituição do nitrito de sódio por extrato vegetal em embutidos cozidos de peru. Cloreto de potássio foi utilizado para substituir total ou parcialmente cloreto de sódio combinado com um mascarador comercial de sabor amargo nas formulações estudadas. Na pesquisa de substituição de nitrito de sódio em embutido cozido de peito de peru, extrato vegetal de aipo foi aplicado como fonte de nitrato e cultura starter como fonte redutora. Os níveis de substituição de cloreto de sódio por cloreto de potássio avaliados foram: 25%, 50% e 75%. Na primeira etapa do trabalho avaliou-se a redução de cloreto de sódio com foco nos atributos sensoriais. De acordo com testes afetivos de Diferença do Controle e de Aceitação, foi possível concluir que a redução de 25% de NaCl é possível de ser realizada sem afetar a aceitação do produto. Na segunda etapa...

Effect of carbonation on the chloride diffusion of mortar specimens exposed to cyclic wetting and drying

Malheiro, Raphaele; Camões, Aires; Ferreira, Rui Miguel; Meira, Gibson; Amorim, M. T. Pessoa de
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em /09/2014 Português
Relevância na Pesquisa
36.63%
Carbonation and chloride ingress are the two main causes of corrosion in reinforced concrete structures. Despite the combined action of these mechanisms being a reality, there is little research on the effect of carbonation on the chloride diffusion in concrete. This work intends to study the influence of carbonation on chloride diffusion of mortar specimens. Cubic mortar specimens were cast with 0.55 of water-cement ratio. After curing, the specimens were subjected to 56 days of wetting and drying cycles. Half the samples were immersed for a day in a 3.5% NaCl solution and then placed for 6 days in a carbonation chamber (4%CO2); the other half were also kept a day in 3.5% NaCl, but after were kept during 6 days in laboratory environment. Afterwards, the depth of chlorides and CO2 penetration was evaluated. Complementary tests were also carried out, such as rapid chloride migration coefficient and water capillary absorption. The results show that carbonation has a direct influence on chloride penetration, decreasing it. The noncarbonated samples showed a profile with higher amount of chloride than carbonated ones. This fact can be related to the refinement of the mortar pores caused by carbonation and observed in water absorption tests.

Transmembrane transport of chloride by Squaramides : in silico study; Transporte transmembranar de cloreto por Squaramides : estudo in silico

Colaço, Ana Rita Freitas
Fonte: Universidade de Aveiro Publicador: Universidade de Aveiro
Tipo: Dissertação de Mestrado
Português
Relevância na Pesquisa
36.66%
The anion transport across cellular membranes is essential to the cell functioning and its regulation depends on transmembrane channels. The malfunction of ion channels leads to channelopathies. In particularly, the impairment of chloride ion channels is associated with cystic fibrosis. These diseases have motivated the supramolecular chemists for the development of new chloride synthetic transporters with potential use in channel replacement therapies. In this context, this thesis reports an in silico study performed to evaluate the ability of five squaramides to assist the chloride transport across a POPC bilayer. Indeed, earlier experimental studies have shown that these small molecules were able to mediate the chloride efflux across POPC vesicles more efficiently than their analogous thioureas and ureas, as mobile-carriers using an anion-exchange mechanism. This theoretical investigation was carried out by a combination of quantum calculations and Molecular Dynamics simulations in a POPC membrane model. The MD simulations were preceded by the development of specific bond term parameters for the squaramide moiety using the crystal data from an extensive series of squaramides. The remaining parts of these molecules were described with GAFF default parameters. The phospholipids were described with parameters taken from LIPID11. The passive diffusion of chloride complexes was investigated by placing each receptor in two different starting positions: in the water slab and in the bilayer core of the POPC membrane model. In both cases the receptor moved towards the water/lipid interface and accommodated themselves below the lipid head groups. In the first case...

Effect of chloride dialysate concentration on metabolic acidosis in aintenance hemodialysis patients

Marques,F.O.; Libório,A.B.; Daher,E.F.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2010 Português
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Hyperchloremia is one of the multiple etiologies of metabolic acidosis in hemodialysis (HD) patients. The aim of the present study was to determine the influence of chloride dialysate on metabolic acidosis control in this population. We enrolled 30 patients in maintenance HD program with a standard base excess (SBE) ≤2 mEq/L and urine output of less than 100 mL/24 h. The patients underwent dialysis three times per week with a chloride dialysate concentration of 111 mEq/L for 4 weeks, and thereafter with a chloride dialysate concentration of 107 mEq/L for the next 4 weeks. Arterial blood was drawn immediately before the second dialysis session of the week at the end of each phase, and the Stewart physicochemical approach was applied. The strong ion gap (SIG) decreased (from 7.5 ± 2.0 to 6.2 ± 1.9 mEq/L, P = 0.006) and the standard base excess (SBE) increased after the use of 107 mEq/L chloride dialysate (from -6.64 ± 1.7 to -4.73 ± 1.9 mEq/L, P < 0.0001). ∆SBE was inversely correlated with ∆SIG during the phases of the study (Pearson r = -0.684, P < 0.0001) and there was no correlation with ∆chloride. When we applied the Stewart model, we demonstrated that the lower concentration of chloride dialysate interfered with the control of metabolic acidosis in HD patients...

Protective Effects of Sodium Selenite and Vitamin E on Mercuric Chloride-Induced Cardiotoxicity in Male Rats

Karaboduk,Hatice; Uzunhisarcikli,Meltem; Kalender,Yusuf
Fonte: Instituto de Tecnologia do Paraná - Tecpar Publicador: Instituto de Tecnologia do Paraná - Tecpar
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2015 Português
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This study was designed to investigate the protective effects of sodium selenite and/or vitamin E against mercuric chloride-induced cardiotoxicity. Male Wistar rats (n=48, 310±10 g) were administered mercuric chloride (1.0 mg/kg bw), sodium selenite (0.25 mg/kg bw), vitamin E (100 mg/kg bw), sodium selenite plus mercuric chloride, vitamin E plus mercuric chloride and sodium selenite plus vitamin E plus mercuric chloride daily via gavage for four weeks. Malondialdehyde (MDA) level, antioxidant enzyme activities [total superoxide dismutase (SOD), catalase (CAT), total glutathione peroxidase (GPx) and total glutathione-S-transferase (GST)], and histopathological changes in the heart tissue were evaluated. Results showed that mercuric chloride exposure resulted in an increase in the MDA level and a decrease in the SOD, CAT, GPx and GST activities, with respect to the control. Light microscopic investigations revealed that mercuric chloride induced histopathological changes in the heart tissue. A significant decrease in the MDA level and a significant increase in the SOD, CAT, GPx and GST activities were observed on the supplementation of sodium selenite and/or vitamin E to mercuric chloride-treated rats, which showed that, sodium selenite and/or vitamin E significantly reduced mercuric chloride induced cardiotoxicity...

Salt equivalence and temporal dominance of sensations of different sodium chloride substitutes in butter

Fonte: Institute of Food Research and the Hannah Research Institute Publicador: Institute of Food Research and the Hannah Research Institute
Tipo: Artigo de Revista Científica
Português
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36.66%
Studies indicate a positive association between dietary salt intake and some diseases, which has promoted the tendency to reduce the sodium in foods. The objective of this study was to determine the equivalent amount of different sodium chloride replacements required to promote the same degree of ideal saltiness in butter and to study the sensory profile of sodium chloride and the substitutes using the analysis of Temporal Dominance of Sensations (TDS). Using the magnitude estimation method, it was determined that the potencies of potassium chloride, monosodium glutamate and potassium phosphate relative to the 1% sodium chloride in butter are 83·33, 31·59 and 33·32, respectively. Regarding the sensory profile of the tested salt substitutes, a bitter taste was perceived in the butter with potassium chloride, a sour taste was perceived in the butter with potassium phosphate and sweet and umami tastes were dominant in the butter with monosodium glutamate. Of all the salt substitutes tested calcium lactate, potassium lactate, calcium chloride and magnesium chloride were impractical to use in butter.

Bioleaching in brackish waters - effect of chloride ions on the acidophile population and proteomes of model species

Zammit, C.; Mangold, S.; rao Jonna, V.; Mutch, L.; Watling, H.; Dopson, M.; Watkin, E.
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
Publicado em //2012 Português
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High concentrations of chloride ions inhibit the growth of acidophilic microorganisms used in biomining, a problem particularly relevant to Western Australian and Chilean biomining operations. Despite this, little is known about the mechanisms acidophiles adopt in order to tolerate high chloride ion concentrations. This study aimed to investigate the impact of increasing concentrations of chloride ions on the population dynamics of a mixed culture during pyrite bioleaching and apply proteomics to elucidate how two species from this mixed culture alter their proteomes under chloride stress. A mixture consisting of well-known biomining microorganisms and an enrichment culture obtained from an acidic saline drain were tested for their ability to bioleach pyrite in the presence of 0, 3.5, 7, and 20 g L(-1) NaCl. Microorganisms from the enrichment culture were found to out-compete the known biomining microorganisms, independent of the chloride ion concentration. The proteomes of the Gram-positive acidophile Acidimicrobium ferrooxidans and the Gram-negative acidophile Acidithiobacillus caldus grown in the presence or absence of chloride ions were investigated. Analysis of differential expression showed that acidophilic microorganisms adopted several changes in their proteomes in the presence of chloride ions...

Modelo para estimar a penetração de cloretos em concreto com perfil formando pico: verificação da sua precisão; Model to predict the chloride penetration in concrete with profile forming peak: verification of its precision

GUIMARÃES, A.T.C.; HELENE, P.R.L.
Fonte: Rede Latino-Americana de Materiais Publicador: Rede Latino-Americana de Materiais
Tipo: Artigo de Revista Científica
Português
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36.66%
Ataque de cloretos em ambiente marítimo ou em estruturas que são usados sais de degelo nem sempre apresentam perfis com teores diminuindo da superfície externa para o interior do concreto. Alguns perfis apresentam um aumento no teor de cloretos da superfície externa até uma determinada profundidade, diminuindo deste ponto até camadas mais profundas, formando pico. Este tipo de perfil deve ter tratamento diferente do modelo tradicional da segunda lei de Fick, obtendo modelos de estimativa de vida útil mais precisos. Modelo previamente proposto por GUIMARÃES e HELENE estima a penetração de íons cloreto ao longo do tempo para perfis formando pico. Para comprovar a eficiência deste modelo é necessário observar o comportamento do perfil de cloretos com pico de uma mesma estrutura ao longo do tempo. Com este objetivo foram obtidos dois perfis de cloretos de uma mesma estrutura em idades diferentes, 22 anos e 27 anos. Sobre o perfil obtido na idade de 22 anos foram estimados perfis para a idade de 27 anos através de três modelos: a) modelo tradicional considerando a segunda lei de Fick, extrapolando o valor de C S; b) modelo tradicional considerando a segunda lei de Fick, deslocando o eixo do x para a profundidade do pico e c) modelo proposto por GUIMARÃES e HELENE. Os resultados são comparados com o perfil medido na idade de 27 anos...

Methylene Chloride Poisoning in a Cabinet Worker

Mahmud, M; Kales, Stefanos Nicholas
Fonte: National Institute of Environmental Health Sciences Publicador: National Institute of Environmental Health Sciences
Tipo: Artigo de Revista Científica
Português
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More than a million workers are at risk for methylene chloride exposure. Aerosol sprays and paint stripping may also cause significant nonoccupational exposures. After methylene chloride inhalation, significant amounts of carbon monoxide are formed in vivo as a metabolic by-product. Poisoning predominantly affects the central nervous system and results from both carboxyhemoglobin formation and direct solvent-related narcosis. In this report, we describe a case of methylene chloride intoxication probably complicated by exogenous carbon monoxide exposure. The worker's presentation of intermittent headaches was consistent with both methylene chloride intoxication and carbon monoxide poisoning. The exposures and symptoms were corroborated by elevated carboxyhemoglobin saturations and a workplace inspection that documented significant exposures to both methylene chloride and carbon monoxide. When both carbon monoxide and methylene chloride are inhaled, additional carboxyhemoglobin formation is expected. Preventive efforts should include education, air monitoring, and periodic carboxyhemoglobin determinations. Methylene chloride should never be used in enclosed or poorly ventilated areas because of the well-documented dangers of loss of consciousness and death.

Atmospheric chloride deposition in continental Spain

Alcalá, Francisco J.; Custodio, Emilio
Fonte: John Wiley & Sons Publicador: John Wiley & Sons
Tipo: Artículo Formato: 453895 bytes; application/pdf
Português
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15 pages, 9 figures.; The atmospheric bulk deposition rate of chloride in continental Spain was studied to get basic information in order to help in the evaluation of diffuse recharge to aquifers through an environmental chemical balance. Both new, recent data and bibliographic data have been used. Most sampling records are less than 5 years long and often only 1 year long. This means that the calculated mean yearly bulk deposition rate of chloride is quite uncertain by 30% on average, and larger than the values derived form records up to 15 years long. A map of atmospheric bulk deposition of chloride has been drawn using ordinary kriging. The mean bulk deposition rate of chloride varies from 1 to 30 g m-2 year-1 in coastal areas, with strong negative landward gradients between 0·1 and 1 g m-2 year-1 km-1. In the centre of the Iberian Peninsula, chloride deposition rates vary from 0·2 to 0·5 g m-2 year-1, with gradients around or less than 5 × 10-3 g m-2 year-1 km-1. The coefficient of variation of the mean bulk atmospheric deposition rate of chloride, for any place, ranges from 0·1 to 1. Values larger than 0·5 are not a good indicator of natural uncertainty for this series of data that has a skewed distribution. The map of bulk deposition rate and its error is one of the terms needed for aquifer recharge estimation by means of the chloride ion balance.; We would like to thank the endowment of the Spanish Research Project HID1999-0205. The first author is also grateful to the Ministry of Education and Science of Spain for a ‘Juan de la Cierva’ Programme Contract (reference JCI-2007-334).; Peer reviewed

Potentiometric determination of free chloride in cement paste - An alternative method for low-budget laboratories

Delport,D.J.; Potgieter-Vermaak,S.S.; McCrindle,R.I.; Potgieter,J.H.
Fonte: South African Journal of Chemistry Publicador: South African Journal of Chemistry
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2011 Português
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Corrosion of rebar in concrete is commonly associated with, and to a large degree influenced by, the free chloride concentration in the pore water. The amount of chloride in concrete is important because chloride can promote corrosion of steel reinforcement when moisture and oxygen are present. A potentiometric procedure that makes use of direct measurement with a chloride ion selective electrode has been developed to analyze free chloride in the pore water extracted from cement paste.16 The accuracy and reliability of this analytical technique has been checked against a certified reference material, Merck sodium chloride solution. Confidence levels (CL095), of 0.03 and relative standard deviations of 0.2 % for chloride were determined for ordinary Portland cement (OPC) chloride binding capacity.

Effect of inorganic chloride on spontaneous combustion of coal

Tang,Y.-B.; Li,Z.-H.; Yang,Y.I.; Ma,D.-J.; Ji,H.-J.
Fonte: Journal of the Southern African Institute of Mining and Metallurgy Publicador: Journal of the Southern African Institute of Mining and Metallurgy
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2015 Português
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Chlorine-containing minerals are commonly present in coal. Associated minerals such as pyrite can undergo exothermic reactions. Consequently, it is of great significance to study the effect of inorganic chloride on the spontaneous combustion of coal. In this study, the effects of five inorganic chlorides (sodium chloride, magnesium chloride, potassium chloride, calcium chloride, and zinc chloride) on the spontaneous oxidation of coal were investigated. Analysis of the gaseous products of coal oxidization at low temperatures (323K to 453K) showed that the presence of inorganic chlorine in coal markedly decreases O2 consumption and the generation of CO and CO2. Samples of raw coal and chlorine-loaded coal were oxidized for 36 hours under the same experimental conditions. Infrared diffuse reflectance spectroscopy results showed that inorganic chloride can inhibit the oxidative decomposition of some functional structure components (methyl, methylene, methine, and hydroxy) in the coal. The influence of inorganic chloride on the oxidation characteristics of the functional groups in coal during spontaneous combustion was investigated using benzyl alcohol and 1-phenyl propanol as model compounds, which were tested under the same experimental conditions as the coal samples. The oxygen consumption of model compounds with and without the addition of inorganic chloride further suggested that inorganic chloride may hinder the oxygenolysis of these structures during low-temperature oxidation. This phenomenon can be attributed to the radical reaction from the perspective of radical chemistry. It can therefore be concluded that inorganic chlorides play an inhibitory role in the spontaneous combustion of coal.

Chloride-binding effect of blast furnace slag in cement pastes containing added chlorides

Potgieter,J.H.; Delport,D.J.; Verryn,S.; Potgieter-Vermaak,S.S.
Fonte: South African Journal of Chemistry Publicador: South African Journal of Chemistry
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2011 Português
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Corrosion of rebar in concrete is commonly associated with, and to a large degree influenced by, the free chloride concentration in the pore water. It is standard industry practice to add various mineral admixtures such as pulverised fuel ash (PFA), or fly ash, ground granulated blast furnace slag (GGBS) and silica fume (SF), to concrete mixtures to increase the corrosion resistance of the reinforcement in the matrix and its subsequent design life span. Various investigations have reported on the effect of mineral admixtures and additions on chloride binding in cementitious matrices, and the current study contributes further to knowledge in this field. Unlike previous investigations, this study attempted to make a clear distinction between the contributions of the two components in a blended cement consisting of ordinary Portland cement (OPC) and ground blast furnace slag (BFS). These contributions of each component have been quantified. Relationships between the total amount of chloride bound, the level of BFS additions, and the levels of initial chloride content present in the matrix were determined. It was found that the OPC/BFS blended cement with partial BFS replacements of up to 50 % displayed a lower binding capacity than that of the OPC on its own. This observation was derived based on the assumption that the OPC and slag reactions were treated as competing and equivalent and did not take any potential time delays into account...