• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 5
  • 2
  • Tagged with
  • 8
  • 8
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The effect of neutral salts on the hydrolysis of copper sulfate.

Stokes, Jefferson Adger 05 1900 (has links)
No description available.
2

A comparative study of contacting equipment for the recovery of copper from cupric sulphate solution.

January 2005 (has links)
Ion exchange for the recovery of metals from solutions is a well established process. It features significantly in terms of being able to recover valuable substances from what would otherwise be waste streams as well as recovering substances that could be harmful to the environment if left in the waste stream. The more popular options for ion exchange processes could be batch, fixed bed, fluidized, moving bed, and chromatographic columns. Although most ion exchange processes tend to be batch processes making use of the fixed bed columns, technological developments enable the use of fluidized beds to be explored. The main purpose of this research was to compare the performance of a fixed bed ion exchange system with a fluidized ion exchange system for the recovery of copper from a cupric sulphate solution. By experimentation the bed depth required for each type of equipment (in order to achieve a specified percentage recovery of copper from a specified feed) was determined. The comparative advantage of one type of equipment over the other ensures the correct type of system to be used for a sulphate solution of a particular concentration. This study provides a basis for comparative studies of contacting equipment for the removal of other substances from dilute solutions. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2005.
3

Paramagnetic resonance absorption in two sulfates of copper

January 1948 (has links)
Robert D. Arnold and Arthur F. Kip. / "November 1, 1948." / Bibliography: p. 14. / Army Signal Corps Contract No. W36-039-sc-32037; Project No. 102B. Dept. of the Army Project No. 3-99-10-022.
4

The Stress Protein Response of Pimephales promelas to Copper

Covington, Sean M. 05 1900 (has links)
Organisms synthesize stress proteins in response to a variety of stressors. The 68/70-kDa proteins (synonymous to the 72/73-kDa proteins) have shown to be the most promising stress proteins, and have been proposed as a biomarker of general organismal stress. The 68/70-kDa proteins were used in an antigen/antibody based approach to determine the duration of the stress protein response of Pimephales promelas following an acute exposure to copper sulphate.
5

Fornecimento de cobre na produção de mudas cítricas em diferentes substratos /

Almeida , Tatiana Rezende Pires de, 1981- January 2008 (has links)
Orientador: Sarita Leonel / Banca: Hélio Grassi Filho / Banca: José Eduardo Crespe / Resumo: A citricultura brasileira destaca-se mundialmente, com ênfase para o Estado de São Paulo o maior produtor citrícola do país. A produção de mudas é o alicerce da citricultura atual e a adubação um dos principais entraves do processo. A deficiência de cobre em mudas cítricas tornou-se um sério problema para os viveiristas. A fim de se detectar a melhor forma de fornecimento de cobre às mudas cítricas aliado a diferentes substratos utilizados por viveiristas realizou-se um experimento em viveiro comercial na cidade de Botucatu, SP. Foram utilizados substratos comerciais à base de fibra de coco (Amafibra) e de casca de pinus (Lupa e Eucatex) e cinco tratamentos: testemunha; Recop (1,8g L-I); Coptrac (3 mL L-I); Cobre Stoller (0,04 mL L-I) e Sulfato de Cobre (2,5 g L-I). O experimento foi instalado no mês de julho de 2006 onde as sementes de limoeiro 'Cravo' (Citrus limonia Osbeck)foram semeadas em canteiros. Após quatro meses, as plantas foram transplantadas para sacolas com capacidade de 4 L em bancadas e foram dispostas intercalando-se os substratos. Aproximadamente quatro meses depois do transplante as plantas receberam os enxertos de laranjeira 'Valência' (Citrus sinensis L. Osbeck). As avaliações eram mensais a partir de Fevereiro/2007 quando estavam com aproximadamente 90 dias após o transplante. Tomou-se medida dos parâmetros a altura média das plantas (em), o diâmetro médio do porta-enxerto (mm), número médio de folhas por planta, massa de matéria seca 2 da parte aérea e do sistema radicular, atividade da enzima peroxidase (H202 consumido g-l m.f.) e teor total de fenóis (mg de ácido gálico g-I amostra). O delineamento estatístico empregado foi o de parcelas subdivididas, sendo a parcela principal as formas de aplicação de cobre e as subparcelas os diferentes substratos, perfazendo um total de ...(Resumo completo, clicar acesso eletrônico baixo) / Abstract: The Brazilian citrus industry is worldwide known with emphasis on the State of Sao Paulo, the largest producer of citrus in Brazil. The production of seedlings is the foundation of the current citrus and fertilization one of the main barriers of the processo The deficiency of copper in citrus nurseries has become a serious problem for the nurserymen. In order to detect the best way of supply of copper to citrus nurseries allied to different substrates used by nurserymen we carried out experiments in commercial nursery in the city of Botucatu, Brazil. It was used commercial-based substrates fibers from coconut (Amafibra) and the bark of pine (Lupa and Eucatex) and five treatments: control; Recop (1.8 g L-I); Coptrac (3 mL L-I); Copper Stoller (0.04 mL L-I) and copper sulfate (2.5 g L-I). The experiment was installed in the month of July 2006 where the seeds of Rangpur lime (Citrus limonia Osbeck) were sown on benches. After four months the plants were transplanted into bags with a capacity of 4L on benches and were willing to intercalate the substrates. Approximately four months after the transplant the plants receivedthe grafts of sweet orange (Citrus sinensis L. Osbeck). The evaluations were monthly from February/2007 when they were approximately with 90 days after the transplant. It took measure of the parameters of the average plant height (cm), the average diameter of the root stock (mm), average number of leaves per plant, dry matter from leafs and roots, activity of the enzyme peroxidase (H202 consumed g-l ct) and total phenol content (mg acid gálico g-I sample). The statistical design applied was subdivided plots, and the main plot way of application of copper and sub-plots of the different substrates, giving a total of fifteen treatments with six repetitions. Each plot was composed of twenty plants. It was verified that the...(Complete abstract click electronic access below) / Mestre
6

Fornecimento de cobre na produção de mudas cítricas em diferentes substratos

Almeida , Tatiana Rezende Pires de [UNESP] 15 February 2008 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:26:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-02-15Bitstream added on 2014-06-13T20:54:56Z : No. of bitstreams: 1 almeida_trp_me_botfca_prot.pdf: 3956278 bytes, checksum: b0e9f46d81ded27a8020a368979a09fa (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / A citricultura brasileira destaca-se mundialmente, com ênfase para o Estado de São Paulo o maior produtor citrícola do país. A produção de mudas é o alicerce da citricultura atual e a adubação um dos principais entraves do processo. A deficiência de cobre em mudas cítricas tornou-se um sério problema para os viveiristas. A fim de se detectar a melhor forma de fornecimento de cobre às mudas cítricas aliado a diferentes substratos utilizados por viveiristas realizou-se um experimento em viveiro comercial na cidade de Botucatu, SP. Foram utilizados substratos comerciais à base de fibra de coco (Amafibra) e de casca de pinus (Lupa e Eucatex) e cinco tratamentos: testemunha; Recop (1,8g L-I); Coptrac (3 mL L-I); Cobre Stoller (0,04 mL L-I) e Sulfato de Cobre (2,5 g L-I). O experimento foi instalado no mês de julho de 2006 onde as sementes de limoeiro 'Cravo' (Citrus limonia Osbeck)foram semeadas em canteiros. Após quatro meses, as plantas foram transplantadas para sacolas com capacidade de 4 L em bancadas e foram dispostas intercalando-se os substratos. Aproximadamente quatro meses depois do transplante as plantas receberam os enxertos de laranjeira 'Valência' (Citrus sinensis L. Osbeck). As avaliações eram mensais a partir de Fevereiro/2007 quando estavam com aproximadamente 90 dias após o transplante. Tomou-se medida dos parâmetros a altura média das plantas (em), o diâmetro médio do porta-enxerto (mm), número médio de folhas por planta, massa de matéria seca 2 da parte aérea e do sistema radicular, atividade da enzima peroxidase (H202 consumido g-l m.f.) e teor total de fenóis (mg de ácido gálico g-I amostra). O delineamento estatístico empregado foi o de parcelas subdivididas, sendo a parcela principal as formas de aplicação de cobre e as subparcelas os diferentes substratos, perfazendo um total de... / The Brazilian citrus industry is worldwide known with emphasis on the State of Sao Paulo, the largest producer of citrus in Brazil. The production of seedlings is the foundation of the current citrus and fertilization one of the main barriers of the processo The deficiency of copper in citrus nurseries has become a serious problem for the nurserymen. In order to detect the best way of supply of copper to citrus nurseries allied to different substrates used by nurserymen we carried out experiments in commercial nursery in the city of Botucatu, Brazil. It was used commercial-based substrates fibers from coconut (Amafibra) and the bark of pine (Lupa and Eucatex) and five treatments: control; Recop (1.8 g L-I); Coptrac (3 mL L-I); Copper Stoller (0.04 mL L-I) and copper sulfate (2.5 g L-I). The experiment was installed in the month of July 2006 where the seeds of Rangpur lime (Citrus limonia Osbeck) were sown on benches. After four months the plants were transplanted into bags with a capacity of 4L on benches and were willing to intercalate the substrates. Approximately four months after the transplant the plants receivedthe grafts of sweet orange (Citrus sinensis L. Osbeck). The evaluations were monthly from February/2007 when they were approximately with 90 days after the transplant. It took measure of the parameters of the average plant height (cm), the average diameter of the root stock (mm), average number of leaves per plant, dry matter from leafs and roots, activity of the enzyme peroxidase (H202 consumed g-l ct) and total phenol content (mg acid gálico g-I sample). The statistical design applied was subdivided plots, and the main plot way of application of copper and sub-plots of the different substrates, giving a total of fifteen treatments with six repetitions. Each plot was composed of twenty plants. It was verified that the...(Complete abstract click electronic access below)
7

Dermal exposure and skin barrier function of workers exposed to copper sulphate at a chemical industry / Christa Steynberg

Steynberg, Christa January 2013 (has links)
Copper exposure is known to be a rare cause of skin irritation and allergic reactions and according to our knowledge occupational dermal exposure to copper sulphate has not yet been characterised. As a result, the objectives of this study were to assess the dermal exposure of workers at a chemical industry to copper sulphate and to characterise the change in the their skin barrier function from before to the end of the work shift, as the skin’s barrier function can greatly influence the permeation of chemical substances. Methods: The change in skin barrier function of reactor workers, crystal and powder packaging workers at the chemical industry were assessed by measuring their dominant hand’s palm, back and wrist as well as their foreheads’ skin hydration, transepidermal water loss (TEWL) and skin surface pH before and at the end of the work shift. Commercial GhostwipesTM were used to collect dermal exposure samples from the same four anatomical areas before and at the end of the shift. Additional dermal exposure samples were collected from the palm and back of hand, prior to breaks 1 and 2. Surface wipe sampling was also conducted at several work and recreational areas of the chemical industry. Wipe samples were analysed by an accredited analytical laboratory, according to NIOSH method 9102 by means of Inductively Coupled Plasma-Atomic Emission Spectrometry. Results: Changes in skin hydration of the workers and anatomical areas at the end of the work shift were highly variable, while in general TEWL increased and skin surface pH decreased. Copper was collected from the skin of all workers before the shift commenced, and dermal exposure increased throughout the work shift. All of the work and recreational areas from which surface samples were taken, were contaminated with copper. Conclusion: As a result of intermittent use of inadequate protective gloves and secondary skin contact with contaminated surfaces and work clothing, workers at the chemical industry are exposed to copper sulphate via the dermal exposure route. The decrease in the workers’ skin barrier function (increased TEWL) and skin surface pH is most likely the result of their dermal exposure to sulphuric acid, and may lead to enhanced dermal penetration. The low account of skin irritation or reaction incidences among these workers is contributed to their ethnicity as well as to the low sensitisation potential of copper. Recommendations on how to lower dermal exposure and improve workers’ skin barrier function are made. / MSc (Occupational Hygiene), North-West University, Potchefstroom Campus, 2014
8

Dermal exposure and skin barrier function of workers exposed to copper sulphate at a chemical industry / Christa Steynberg

Steynberg, Christa January 2013 (has links)
Copper exposure is known to be a rare cause of skin irritation and allergic reactions and according to our knowledge occupational dermal exposure to copper sulphate has not yet been characterised. As a result, the objectives of this study were to assess the dermal exposure of workers at a chemical industry to copper sulphate and to characterise the change in the their skin barrier function from before to the end of the work shift, as the skin’s barrier function can greatly influence the permeation of chemical substances. Methods: The change in skin barrier function of reactor workers, crystal and powder packaging workers at the chemical industry were assessed by measuring their dominant hand’s palm, back and wrist as well as their foreheads’ skin hydration, transepidermal water loss (TEWL) and skin surface pH before and at the end of the work shift. Commercial GhostwipesTM were used to collect dermal exposure samples from the same four anatomical areas before and at the end of the shift. Additional dermal exposure samples were collected from the palm and back of hand, prior to breaks 1 and 2. Surface wipe sampling was also conducted at several work and recreational areas of the chemical industry. Wipe samples were analysed by an accredited analytical laboratory, according to NIOSH method 9102 by means of Inductively Coupled Plasma-Atomic Emission Spectrometry. Results: Changes in skin hydration of the workers and anatomical areas at the end of the work shift were highly variable, while in general TEWL increased and skin surface pH decreased. Copper was collected from the skin of all workers before the shift commenced, and dermal exposure increased throughout the work shift. All of the work and recreational areas from which surface samples were taken, were contaminated with copper. Conclusion: As a result of intermittent use of inadequate protective gloves and secondary skin contact with contaminated surfaces and work clothing, workers at the chemical industry are exposed to copper sulphate via the dermal exposure route. The decrease in the workers’ skin barrier function (increased TEWL) and skin surface pH is most likely the result of their dermal exposure to sulphuric acid, and may lead to enhanced dermal penetration. The low account of skin irritation or reaction incidences among these workers is contributed to their ethnicity as well as to the low sensitisation potential of copper. Recommendations on how to lower dermal exposure and improve workers’ skin barrier function are made. / MSc (Occupational Hygiene), North-West University, Potchefstroom Campus, 2014

Page generated in 0.0645 seconds