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Journal articles on the topic 'Solution alcaline'
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1
Rousseau, M. C., P. Brouqui, S. Badiaga, and A. Bourgeade. "Aérosol de streptomycine en solution alcaline dans le traitement des tuberculoses pulmonaires abcédées." Médecine et Maladies Infectieuses 25, no. 6-7 (June 1995): 873–75. http://dx.doi.org/10.1016/s0399-077x(05)80427-5.
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Truong, To Oanh, Robert Hausler, Fréderic Monette, and Patrick Niquette. "Valorisation des résidus industriels de pêches pour la transformation de chitosane par technique hydrothermo-chimique." Revue des sciences de l'eau 20, no. 3 (August 7, 2007): 253–62. http://dx.doi.org/10.7202/016170ar.
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Résumé Le chitosane est une substance biodégradable d’origine naturelle obtenue par la désacétylation de la chitine, qui se trouve dans l’exosquelette des crustacés. Une de leurs applications plus récentes est le traitement des eaux. Pour favoriser l’utilisation du chitosane des exosquelettes de crustacés (crevettes, crabes, etc.) dans le traitement des eaux usées, les procédés de transformation du chitosane ont été simplifiés et optimisés. Dans la présente étude, les crustacés de crevette grise (Palaemodiae) ont été utilisés pour extraire le chitosane. Les expériences ont porté sur les effets des interactions de la concentration de la solution alcaline, du temps et de la température de réaction sur le degré de désacétylation. En plus de simplifier le processus de transformation de trois à deux étapes, les résultats montrent l’influence de la concentration d’hydroxyde de sodium (7,5‑ 12,5 M), du temps de réaction (30 ‑ 180 min) et de la température (80 ‑ 120 oC) sur le degré de désacétylation. La méthode de la spectroscopie infrarouge en film mince a été utilisée pour analyser le degré de désacétylation du chitosane. Un degré de désacétylation de 90 % a été atteint avec une concentration de la solution alcaline de 12,5 M, un temps de réaction de 120 min et une température de 110 oC. Par ailleurs, en réduisant le nombre d’étapes de transformation et la consommation de réactifs, le procédé développé est plus économique et a une meilleure performance environnementale.
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van Linge, A. R. "Sur l'action de l'hypobromite de potassium en solution alcaline sur quelques amides. Préparation du méthène-dioxyaminobenzène." Recueil des Travaux Chimiques des Pays-Bas et de la Belgique 16, no. 2 (September 3, 2010): 44–56. http://dx.doi.org/10.1002/recl.18970160203.
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Gomes, Eleni, Roberto da Silva, and Alcides Serzedello. "Ribonuclease Production by Aspergillus species." Revista de Microbiologia 29, no. 3 (September 1998): 187–92. http://dx.doi.org/10.1590/s0001-37141998000300008.
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Ribonuclease production by Aspergillus flavipes, A. sulphureus and A. fischeri in semi-synthetic medium, after 24-144 hours at 30ºC under shaking, was studied. After cultivation, the medium was separated from micelia by filtration and the resultant solution was used as enzymatic extract. The highest amount of biomass and RNase was obtained after 96 hours of cultivation. The enzymes produced by three species presented similar characteristics, with optimum temperature at 55ºC and two peaks of activity at pH 4.5 and 7.0. A. flavipes RNases were more sensitive to temperature: 50% of the initial activity was lost after 1 hour at 70ºC. After this heat treatment, RNase of A. sulphureus lost 30% of this activity and that of A. fischeri only 16%. The nucleotides released by enzimatic hydrolysis of RNA were separated by ion exchange chromatography in a AG-1X8-formiate column and identified by paper chromatography. This procedure indicated that the raw enzymatic extract of Aspergillus flavipes is able to hydrolyze RNA, releasing 3'-nucleotides monophosphate at pH 4.5 and 3' and 5'-nucleotides monophosphate at pH 7.0 and 8.5. This result suggests that this strain produces two different types of RNase, one acidic and other alcaline, with different specificities.
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Kumar, Shailendra, Ismita Nautiyal, and Shikhar Shukla. "Some physical properties of delignified and compressed Melia dubia wood." BOIS & FORETS DES TROPIQUES 341 (July 20, 2019): 71. http://dx.doi.org/10.19182/bft2019.341.a31758.
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Cette étude explore les effets de la délignification dans l’amélioration de quelques propriétés physiques du bois comprimé. Les billes de bois d’une plantation de six ans d’âge de Melia dubia (densité = 0,39 g/cm3) ont été délignifiées dans une solution alcaline de NaOH et Na2SO3 pendant 4 heures. Les billes de bois délignifiées ont été séchées jusqu’à contenir 12 % d’humidité, et comprimées à deux températures (120 °C et 150 °C) pendant 2 heures et 4 heures. Les améliorations dans la densité, la recouvrance de la compression (%) et la perte d’épaisseur (%) après la compression ont été observées et comparées avec des échantillons non délignifiés. La densité moyenne du bois délignifié et comprimé (DCW) était de 0,825 g/cm3 (SD = 0,109) ; pour le bois comprimé sans délignification (CW), la densité moyenne était de 0,889 g/cm3 (SD = 0,049). Ces densités diffèrent significativement : les échantillons de DCW ont montré une basse recouvrance de la compression (2,97 % à 5,22 %), tandis que, comparativement, les échantillons de bois CW ont montré une haute recouvrance de la compression (48,47 % à 38,05 %). La perte moyenne d’épaisseur (%) dans les échantillons de DCW a varié de 47,22 % à 52,26 %, et elle était approximativement de 10 % plus haute (58,77 % à 61,91 %) dans les échantillons de CW, sans délignification.
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Delalu, H., and A. Marchand. "Cinétique de formation du (N-amino-aza-3-bicyclo[3,3,0]octane) par action de NH2Cl et NHCl– sur l’aza-3-bicyclo[3,3,0]octane en solution alcaline concentrée." Journal de Chimie Physique 89 (1992): 1413–25. http://dx.doi.org/10.1051/jcp/1992891413.
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Gerdes, A., W. Schwarz, and F. H. Wittmann. "pH-Wert der Porenlösung in Beton / pH-Value of the Pore Solution in Concrete." Restoration of Buildings and Monuments 4, no. 2 (April 1, 1998): 159–72. http://dx.doi.org/10.1515/rbm-1998-5259.
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Abstract The risk for corrosion is substantially increased in carbonated concrete. Recently, methods for realcalization of carbonated structural concrete elements have been proposed and applied. A stable pH-value higher than 10 is aimed to be achieved by impregnation with aqueous solutions of alcali carbonates. Analyses of impregnated concrete elements in practice has shown, however, that the pH-value of the pore solution drops to values below 10 despite an apparently sufficient alcali content. Results described in this contribution are used to develop a hypothesis in order to explain the time-dependent decrease ofpH-value. It is concluded that the composition of the pore solution and the chemical equilibrium is changed in the presence of dissolved sulfates. Under these conditions, a comparatively high content of alcali carbonates is not sufficient any more to ascertain a pH-value higher than 10. The chemical mechanisms suggested here are used to interprete observations in practical cases. The complex interactions of dissolved ions in the pore solution of concrete has hardly been taken into account up to now. For this reason, the application of realcalization as discussed in this contribution cannot be recommended so far
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Yu, Na, Jia Yan Qin, Hong Yu Bao, and Xi Qing Yue. "Optimization of Hydrolysis Pretreatment Conditions with Two Kinds of Enzymes for Enhanced Proteolysis in Egg Yolk Solution Using Response Surface Methodology." Advanced Materials Research 317-319 (August 2011): 2208–14. http://dx.doi.org/10.4028/www.scientific.net/amr.317-319.2208.
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Response surface methodology was used to optimize proteolysis of egg yolk solution using Alcalase and Flavorase according to three conditions, the ratio of two enzyme concentration (Alcalase and Flavorase), pH values and hydrolytic time. The responses degree of hydrolyzation (DH) and peptide yield were studied. The protein subunit from egg yolk was purified and hydrolyzed by Alcalase and Flavorase step by step. The results showed that the best ratio of enzyme concentration was 0.8% for Alcalase, and 0.4% for Flavorase to hydrolyzed 10% yolk solution. The hydrolytic time of the two enzymes was 2h respectively. Then the solution was incubated for 4h at 55°C while rotating at 60 r./min. To evaluate the hydrolysate, both the degrees of hydrolysis (DH) and the yields of the polypeptides were taken into consideration. The optimum ratios of enzyme and hydrolytic time were 2.43 and 1.14 respectively, and the optimum pH was 6.64. The optimized DH was 13.233%, and peptide yield was up to 45.573mg/ml.
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Rendón-Ángeles, J. C., L. M. Valadez-Farias, J. L. Rodríguez-Galicia, J. Méndez-Nonell, and J. López-Cuevas. "Síntesis y sinterización de soluciones sólidas de cromita de lantano obtenidas por el método de coprecipitación en medio alcalino." Boletín de la Sociedad Española de Cerámica y Vidrio 43, no. 5 (October 30, 2004): 869–76. http://dx.doi.org/10.3989/cyv.2004.v43.i5.415.
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Yu, Jianmei, Ivy N. Smith, Nadia Idris, Nicole Gregory, and Nona Mikiashvili. "Oxidative Stability of Protease Treated Peanut with Reduced Allergenicity." Foods 9, no. 6 (June 10, 2020): 762. http://dx.doi.org/10.3390/foods9060762.
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Oxidative stability and allergenicity are two major concerns of peanuts. This study evaluated the impact of protease treatment of peanuts on its oxidative stability during storage. The raw and dry-roasted peanut kernels were hydrolyzed with Alcalase solution at pH 7.5 for 3 h. The contents of Ara h 1, Ara h 2, and Ara h 6 in peanuts were determined before and after enzyme treatment by a sandwich ELISA. After drying, the samples were packed in eight amber glass jars and stored at 37 °C for 1–8 weeks. Controls are untreated raw and dry-roasted peanuts packed and stored in the same way as their treated counterparts. Samples were taken biweekly to determine peroxide value (PV) and thiobarbituric acid reactive substances (TBARS) as indicators of oxidation (n = 3), and to determine antioxidant activity. Alcalase treatment reduced intact major allergens Ara h 1, Ara h 2, and Ara h 6 by 100%, 99.8%, and 85%, respectively. The PVs of Alcalase-treated raw and roasted peanuts was lower than those of untreated (p < 0.05) over the 8-week storage. The TBARS of Alcalase-treated raw peanuts were slightly higher than that of untreated (p < 0.05), but the TBARS of Alcalase-treated dry-roasted peanuts were slightly but significantly lower than that of untreated (p < 0.05). The protease treatment increased the antioxidant activities including reducing power, DPPH free radical scavenging capacity, and metal chelating capacity of peanuts.
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van Laer, Marc H. "Contribution a L'etude des Phénomènes de Migration Électrolytique: Electrolyse des Solutions Mixtes de Sels Alcalins." Recueil des Travaux Chimiques des Pays-Bas 39, no. 5 (September 3, 2010): 301–29. http://dx.doi.org/10.1002/recl.19200390504.
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Cheng, I.-Chun, Jin-Xian Liao, Jhih-Ying Ciou, Li-Tung Huang, Yu-Wei Chen, and Chih-Yao Hou. "Characterization of Protein Hydrolysates from Eel (Anguilla marmorata) and Their Application in Herbal Eel Extracts." Catalysts 10, no. 2 (February 8, 2020): 205. http://dx.doi.org/10.3390/catal10020205.
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The enzymatic hydrolysis of fish proteins is the principle method for converting under-utilized fish into valuable products for the pharmaceutical and health food industries. In this study, three commercial enzymes (alcalase, bromelain, and papain) were tested for their ability to create eel protein hydrolysates (EPHs) from whole eel (Anguilla marmorata). Freeze-dried EPHs had almost more than 80% solubility (p < 0.05) in solutions ranging from pH 2–10. The amino acid profiles of the EPHs showed a high percentage of essential amino acids, including histidine, threonine, valine, isoleucine, and leucine. The emulsion activity index (EAI) of EPH resulted as follows: alcalase group (36.8 ± 2.00) > bromelain group (21.3 ± 1.30) > papain group (16.2 ± 1.22), and the emulsion stability index (ESI) of EPH was: alcalase group (4.00 ± 0.34) > bromelain group (2.62 ± 0.44) > papain group (1.44 ± 0.09). As such, EPH has a high nutritional value and could be used as a supplement to diets lacking protein. EPH showed excellent solubility and processed interfacial properties, which are governed by its concentration. Among of them the alcalase group had the best antioxidant effect at 1,1-diphenyl-2-pyridinohydrazinyl (DPPH) radical method, determination of reducing power and ABTS test compared with other groups. EPH may be useful in developing commercial products like herbal eel extracts that are beneficial to human health.
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Basic, Zorica, Vesna Kilibarda, Silva Dobric, and Radmila Resanovic. "In vitro study of vitamins B1, B2 and B6 adsorption on zeolite." Vojnosanitetski pregled 68, no. 1 (2011): 15–20. http://dx.doi.org/10.2298/vsp1101015b.
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Background/Aim. Zeolites are the hydratised alumosilicates of alcali and earthalcali cations, which have a long three-dimensional crystal structure. Preparations on the basis of zeolites are used for adsorption of organic and nonorganic toxic substances and they, also, find more and more use in veterinary and human medicine and pharmacy. The aim of this study was to evaluate the possibilities of zeolite to adsorb vitamins B1, B2 and B6 in acid and neutral solutions, as well as the characteristics of the process (saturability, reversibility and competitivness). Methods. The specific and sensitive HPLC method with fluorescent detector was used for determination of vitamins B1, B2 and B6. Analyte separation and detection were carried out by applying the reverse-phase method on column C18. An in vitro experiment was done by testing the influence of pH value (2 and 7), concentration of vitamin solution (1, 2 and 5 mg/L), the lenght of contact with zeolite (10-180 min) and cation competitiveness on the exchange capacity, which is achieved by media and zeolite contact, as well as a possible vitamins desorption through changing pH value of the solution at 37?C. Jon competitiveness was examined by adding commercial feed mixture (grower) with a defined content of the examined vitamines in zeolite solutions the pH = 2 and pH = 7. Results. Vitamins B1, B2 and B6 were stable in both pH=2 and pH = 7 solutions at 37?C, in the defined time intervals. In acid solution concentrations of vitamins significantly declined in the first 10 min, with no significant decline in further 30 min for all the three concentrations testch. In neutral solution, after the addition of 1% zeolite, decrease in vitamins concentrations was slightly lower than in acid solution, but also significant in the first 10 min of the contact with zeolite. It was found that zeolite, which adsorbed vitamins in acid solution, transferred in the neutral one released a significant quantity of adsorbed vitamins after 30 min of extraction on 37?C. Vitamins B1, B2 and B6 from a commercial feed mixture in pH = 2 solution, at 37?C, were significantly adsorbed on zeolite after 30 min of the contact (21.87%, 20.15% and 4.53%, respectively), while in neutral solution there was no statistically significant adsorption. Conclusion. Zeolite significantly adsorbs vitamins B1, B2 and B6 in acid and neutral solutions at 37?C, already in the first 10 min of the contact. Adsorption was irreversible, but partly reversible after changing pH from acid to neutral. This is a significant ions competition for adsorption on zeolite in neutral solution, so no statistically significant vitamins B1, B2 and B6 adsorption occurs, while in acid solution competition is less, thus zeolite significanthy adsorbs these vitamins, although in less degree than in conditions with no concurrent ions.
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Yen, Do Thi, and Nguyen Thi May. "OPTIMIZATIONOFENZYMATIC HYDROLYSIS PROCESS FROM SHRIMP BY-PRODUCT FOR SHRIMP SAUCE PRODUCTION." Vietnam Journal of Science and Technology 57, no. 3B (November 12, 2019): 97. http://dx.doi.org/10.15625/2525-2518/57/3b/14426.
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Shrimp by-product from shrimp processing industry adapted to food safety was hydrolyzed by alcalase and flavourzyme and optimized by response surface methodology. Shrimp by- product was grounded and treated with fixed alcalase 0.2% (4.8AU/kg protein) andflavourzyme loadings (0.1-0.4%), pH (6.0-9.0), temperature (45-650C) and hydrolysis time (5-13h) in order to improve hydrolysis process in shrimp sauce production. At optimal conditions of pH of 7.5, temperature of 590C,flavourzymeloadings of 0.4% (100LAPU/g protein), alcalaseof 0.2%, and hydrolysis time of 8.2h, hydrolysis degree was 36.76% compared to control sample (hydrolysis by HCl 6N at 1000C for 24h). Shrimp hydrolysis solution was mixed with 25% of NaCl before fermentation. After 10 days of fermentation, shrimp sauce had total nitrogen of 13.2g/l, amino nitrogen of 9.625 g/l, NH3 of 2.13g/l. These properties and sensory quality were equivalent to control sample(2.5 months of fermentation by traditional process).
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Moreno-Limón, Sergio, and Rodrigo González-Luna. "ANTIHYPERTENSIVE ACTIVITY OF QUINOA (Chenopodium quinoa Willd.) PROTEIN HYDROLYSATES." African Journal of Traditional, Complementary and Alternative Medicines 15, no. 4 (October 16, 2018): 22. http://dx.doi.org/10.21010/ajtcam.v15i4.3.
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Background: Nowadays, there has been an increase in the number of studies focused on the search for bioactive
compounds produced by hydrolytic reactions from natural sources, such as the Quinoa grain, which represents an
interesting agro-alimentary source that can have a beneficial influence on health, specifically antihypertensive potential. For
this reason, the aim of the present study was to evaluate the antihypertensive activity of the protein hydrolysates obtained of
Quinoa, which results important at the time to consider the incorporation of such peptides in the design of functional foods.
Materials and Methods: Quinoa (Chenopodium quinoa Willd.) seeds were ground and the obtained flour was degreased
and the protein isolate was obtained by isoelectric precipitation. The protein isolate was enzymatically hydrolyzed with
Alcalase® and Flavourzyme® and the antihypertensive effect of peptides against angiotensin converting enzyme was
evaluate using a mixture of 50 μL of sample, 50 μL of ACE working solution, 200 μL of substrate working solution and the
fluorescence was determined with a microplate fluorometer following these characteristics: λ (excitation) = 355-375 nm; λ
(emission) = 400-430 nm.
Results: Peptides obtained using Alcalase® (protein content= 72.13%; DH= 31.22%) showed the highest inhibitory
activity against the angiotensin converting enzyme (ACE), close to 88%.
Conclusion: The Quinoa protein hydrolysates can be considered as a new agri-food source to be incorporated in the
elaboration of functional foods with antihypertensive potential.
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Grande, Salvador Carlos, and Erika Cristina Cren. "AVALIAÇÃO DOS EFEITOS DOS PARÂMETROS DE PROCESSO NA EXTRAÇÃO ALCALINA DE PROTEÍNAS DOS FARELOS DE MACAÚBA EMPREGANDO PLANEJAMENTO EXPERIMENTAL FATORIAL." e-xacta 9, no. 1 (June 1, 2016): 89. http://dx.doi.org/10.18674/exacta.v9i1.1782.
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<p>O presente trabalho apresenta um estudo acerca da extração alcalina de proteínas dos farelos de polpa e amêndoa de macaúba. A fim de avaliar a influência dos parâmetros de processo, a saber, concentração de NaCl da solução de extração, razão sólido:solução, temperatura e pH da solução de extração, sobre o rendimento de extração das proteínas dos farelos, um planejamento experimental fatorial (2<sup>4</sup>) foi conduzido. Os parâmetros foram avaliados em 2 níveis, além do ponto central. Para o farelo de amêndoa, a avaliação estatística dos efeitos dos parâmetros para a maximização do rendimento de extração, ao nível de significância de 95%, indicam que o pH e a razão sólido:solução são estatisticamente significativos. No entanto, para o farelo da polpa, os parâmetros que influenciam de forma significativa o rendimento do processo de extração, dentro das faixas investigadas, são a concentração de NaCl, a razão sólido: solução e o pH da solução de extração. Os resultados apontam que para ambos os farelos, a temperatura de extração, dentro da faixa investigada, não exerce influência sobre o rendimento. De um modo geral, o processo de extração alcalina de proteínas dos farelos de macaúba mostra-se promissor, sendo atingidos rendimentos de extração de até 99% e 92%, respectivamente. Mesmo na pior condição experimental de extração, para ambos os farelos, um rendimento acima de 50% foi obtido. Os resultados apresentados são de fundamental importância para futuros estudos que visam otimizar os parâmetros de processo para maximização do rendimento de extração de proteínas, inclusive em escala industrial. </p><p>Abstract</p><p>This work presents a study about alkaline extraction of proteins from macaúba bran. In order to evaluate the influences of the process parameters, namely, the concentration of NaCl solution, ratio solid:solution, temperature and the pH of extraction solution, on protein extraction yield from macaúba bran, an experimental factorial design (2<sup>4</sup>) was conducted. The parameters were evaluated in 2 levels, in addition to the central point. For the kernel bran of macaúba, the statistical evaluation of process parameter effects for the maximization of protein extraction yield, at a significance level of 95%, indicates that the pH and the ratio solid:solution are statistically significant. For the pulp bran of macaúba the parameters that influence significantly the extraction yield of proteins, within ranges investigated, are the concentration of NaCl solution, the ratio solid:solution and the pH of the extraction solution. For both types of bran, the extraction temperature, within range investigated, does not exercise influence, at a significance level of 95%, on the protein extraction yield. In general, the alkaline extraction of proteins from the pulp and the kernel bran of macaúba show to be promising, being achieved extraction yields of up to 99% and 92%, respectively. Even in the worst experimental condition of extraction, for both types of bran, a yield above 50% was obtained. The results obtained and presented are important for future studies aiming industrial application and so to optimize the process parameters of extraction for maximization of protein yield.</p>
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Zhang, Hai Yue, Tian Tian, and Hua Chen. "Optimization of Enzymatic Hydrolysis for Protein from Black Bean by Response Surface Methodology." Advanced Materials Research 781-784 (September 2013): 875–79. http://dx.doi.org/10.4028/www.scientific.net/amr.781-784.875.
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Taking the degree of hydrolysis (DH) as the index, the optimal hydrolysis process for the protein from black bean was explored by response surface methodology (RSM) to prepare polypeptides. Four proteases were used to hydrolyze the black bean protein and determine the DH of black bean protein. The results indicated that the optimal reaction systems were as follows: The black bean protein solution was treated with the alkaline protease hydrolysis firstly and then the trypsin hydrolysis was used in order to improve the DH. The DH of protein was increased to 35.64% and the yield of peptides production was higher than using only alcalase.
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Delarbre, Jean Louis, Luc Maury, and Lucette Bardet. "Analyse Vibrationnelle et Structurale en Série Aliphatique insaturée-Spectres de Vibration de l'Acide Acétylènedicarboxylique et de ses Sels Alcalins en Solution Aqueuse." Journal of Raman Spectroscopy 17, no. 5 (October 1986): 373–80. http://dx.doi.org/10.1002/jrs.1250170502.
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Delarbre, J. L., and L. Et L. Maury Bardet. "Analyse Vibrationnelle et Structurale en Série Aliphatique Saturée VI-Spectres de Vibration de l'acide Diéthylmalonique et de ses sels Alcalins en Solution Aqueuse." Journal of Raman Spectroscopy 16, no. 1 (February 1985): 11–21. http://dx.doi.org/10.1002/jrs.1250160104.
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Delarbre, Jean Louis, Luc Maury, and Lucette Bardet. "Analyse vibrationnelle et structurale en série aliphatique saturée. 7-spectres de vibration de l'Acide hydroxymalonique et de ses sels alcalins en solution aqueuse." Journal of Raman Spectroscopy 16, no. 4 (August 1985): 288–96. http://dx.doi.org/10.1002/jrs.1250160413.
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Delarbre, J. L., E. Fabregue, L. Maury, and L. Bardet. "Analyse Vibrationnelle et Structurale en Série Aliphatique Saturee. VIII-Spectres de Vibration de l'acide Glutarique et de ses Sels Alcalins en Solution Aqueuse." Journal of Raman Spectroscopy 19, no. 3 (May 1988): 167–74. http://dx.doi.org/10.1002/jrs.1250190305.
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Delarbre, J. L., E. Fabrègue, L. Maury, and L. Bardet. "Analyse Vibrationnelle et Structurale en Série Aliphatique Saturée. IX-Spectres de Vibration de l'Acide Pimelique et de ses Sels Alcalins en Solution Aqueuse." Journal of Raman Spectroscopy 20, no. 1 (January 1989): 41–48. http://dx.doi.org/10.1002/jrs.1250200109.
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Ramsis, H., J. Roger, J. L. Delarbre, L. Maury, and A. Ennaciri. "Analyse vibrationnelle et structurale de composés à pont disulfure I—spectres de vibration de l'acide dithiodiglycolique et de ses sels alcalins en solution aqueuse." Journal of Raman Spectroscopy 31, no. 12 (2000): 1099–106. http://dx.doi.org/10.1002/1097-4555(200012)31:12<1099::aid-jrs651>3.0.co;2-y.
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Dzyuba, B., S. Boryshpolets, M. Psenicka, M. Rodina, D. Gela, and O. Linhart. "138. Survival of common carp Cyprinus Carpio embryos after chorion modification by alcalase and following incubation in vitrifying solutions." Cryobiology 61, no. 3 (December 2010): 404. http://dx.doi.org/10.1016/j.cryobiol.2010.10.142.
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Ramsis, H., P. Monmouton, J. L. Delarbre, and Et L. Maury. "Analyse Vibrationnelle et Structurale en Série Aliphatique Saturée. X-Spectres de Vibration de l'Acide Adipique et de ses Sels Alcalins de Potassium en Solution Aqueuse." Journal of Raman Spectroscopy 26, no. 4 (April 1995): 265–72. http://dx.doi.org/10.1002/jrs.1250260403.
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Goma Ginesta, Ferrán. "Análisis de los factores que tienen influencia en la disminución de resistencias residuales por disolución alcalina en los morteros intersticiales de hormigones con cemento aluminoso. Evaluación de los límites de riesgo en el caso de los techos." Materiales de Construcción 45, no. 238 (June 30, 1995): 19–34. http://dx.doi.org/10.3989/mc.1995.v45.i238.558.
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Xu, Jing, Yu Ting Wang, Xiao Yu Wang, Xin Ru Li, and Qian Xin Dang. "Antioxidant Activity of Enzymatic Hydrolysates of High-Temperature Soybean Meal Pretreated with High Pressures." Advanced Materials Research 1092-1093 (March 2015): 1519–24. http://dx.doi.org/10.4028/www.scientific.net/amr.1092-1093.1519.
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Effect of high-temperature soybean meal hydrolysates was to be studied in this paper. Hhigh-temperature soybean meal was treated by high pressure. And Alcalase 2.4 L was used to hydrolyze high-temperature soybean meal, three kinds of solutions with relative molecular mass of > 10 000 Da, 5000 Da – 10 000 Da and < 5 000 Da were obtained by ultrafiltration of hydrolysates, and they were administrated mice by gastric perfusion, respectively. Levels of superoxide dismutase (SOD), glutathione peroxidase (GSH-PX) and malondialdehyde (MDA) in liver were separately tested with reagent kits. Results showed that SOD and GSH-PX activities were significantly improved and MDA content was reduced in liver of mice by hydrolysates, which indicated that high-temperature soybean meal hydrolysates can improve antioxidant indexes of mice and enhance antioxidation capacity of body.
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Zidane, Fatiha, Fakhreddine Qassid, Soumia El Basri, Jalila Bensaid, Patrick Drogui, and Jean-François Blais. "Décoloration des effluents par des structures adsorbantes générées par électrocoagulation avec des électrodes d’aluminium et de fer." Revue des sciences de l’eau 25, no. 1 (March 28, 2012): 33–47. http://dx.doi.org/10.7202/1008534ar.
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La présence de colorants dans les effluents industriels constitue un problème important dans plusieurs pays. Les industries qui rejettent de tels composés sont principalement les industries textiles et les industries de pâtes et papiers. La décharge de tels effluents dans le milieu récepteur cause une demande excessive en oxygène et ceux-ci doivent par conséquent être traités avant tout rejet dans l’environnement. Cette étude propose une nouvelle option pour le traitement de ce type de pollution, soit la décoloration par utilisation de structures adsorbantes produites préalablement par électrocoagulation avec des électrodes de fer et d’aluminium. Trois structures ont ainsi été synthétisées dans un électrolyte support constitué de 10-2 mol NaCl•L-1. Les trois structures synthétisées ont été analysées par diffraction des rayons X (DRX) et microscopie électronique à balayage (MEB). Ces analyses ont montré la présence dominante de bayerite (Al(OH)3) dans la structure produite à partir d’électrodes d’aluminium et de magnétite (Fe3O4) et lépidocrocite (γ-FeO(OH)) dans la structure générée à partir d’électrodes de fer. Le composé généré en utilisant les deux types d’électrodes contient, pour sa part, de la bayerite et de la goethite (α-FeO(OH)). Un suivi de la décoloration a été réalisé dans des solutions acides (pHi = 4,8) et alcaline (pHi = 9,8) contaminées par un colorant diazoïque ([Trypan bleu]i = 3,75 mg•L-1). Les résultats obtenus ont montré l’efficacité de ces structures, avec des rendements de décoloration compris entre 94 et 99 %, et un rendement d’élimination de la DCO pouvant atteindre 96 %, selon le pH du milieu.
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Aubertin, N., N. Neveux, R. Gerardin, and O. Evrard. "Synthèse d'un sulfatoferrate de potassium et son efficacité dans le traitement des eaux." Revue des sciences de l'eau 9, no. 1 (April 12, 2005): 17–30. http://dx.doi.org/10.7202/705240ar.
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Depuis le milieu du siècle dernier, nous savons que le fer existe à son degré d'oxydation supérieur VI dans l'ion tétraoxoferrate(VI) FeO42-, isostructural de SO42-, CrO42-, MnO42-. Cette espèce mise en solution aqueuse oxyde l'eau en O2, et ce quelque soit le pH de cette solution. La vitesse de cette réaction est très grande en milieu acide, plus lente en milieu alcalin où elle conduit à la précipitation de Fe(OH)3. On peut donc envisager son emploi comme réactif polyfonctionnel : oxydant et floculant, dans le traitement de certaines eaux. La première partie de ce travail décrit une voie originale de synthèse à l'état solide, à la température ambiante, du sel de formule K2(Fe,S)O4, appelé sulfatoferrate de potassium, qui contient l'entité FeO42-. En effet, jusqu'à ce jour seules des synthèses par voie aqueuse, à rendements très faibles, chimiques ou électrochimiques, ont été utilisées pour obtenir FeO42-. Dans une seconde partie, nous avons mesuré les propriétés oxydantes et floculantes du sulfatoferrate de potassium agissant sur deux types d'eaux usées urbaines, chargées (MEST=258 mg.L-1, DCO=549 mg.L-1) et peu chargées (MEST=9 mg.L-1, DCO=37 mg.L- 1). Cette étude effectuée en collaboration avec le Centre International de l'Eau de Nancy (NANC.I.E.) nous a permis de préciser les conditions optimales d'emploi de K2(Fe,S)O4 et de comparer ses performances à celles de FeCl3.6H2O et Al2(SO4)3.18H2O. Sur une eau chargée, l'abattement de la MEST est meilleur avec FeCl3.6H2O et Al2(SO4)3.18H2O, tandis que K2(Fe,S)O4 est plus efficace vis à vis de l'abattement de la DCO. Sur une eau peu chargée, c'est l'effet bactéricide de K2(Fe,S)O4 qui est le plus remarquable; une dose de 10 mg.L-1 en fer (VI) anéantit 99,70% des coliformes totaux et 99,90% des coliformes fécaux.
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Andrukaitis, E., P. W. M. Jacobs, and J. W. Lorimer. "Electrochemical preparation and properties of the mixed-crystalline hexavanadates MxM′4−xV6O16, M, M′ = NH4, K, Rb, Cs." Canadian Journal of Chemistry 68, no. 8 (August 1, 1990): 1283–92. http://dx.doi.org/10.1139/v90-198.
Full textAbstract:
Coherent deposits of oriented, crystalline MxM′4−xV6O16+δ, with M, M′ = K, Rb, Cs, or NH4, 0.0 ≤ x ≤4.0 and 0.00 ≤ δ ≤ 0.13, have been prepared electrochemically on various conducting substrates from metavanadate solutions containing ammonium or alkali metal cations, singly or in combination. Chemical analysis and X-ray diffraction show that the deposits consist of a continuous series of mixed crystals based on the isomorphic end members M4V6O16 and M′4V6O16.The deposits can be oxidized electrochemically, with removal of M and M′ atoms, and the products can be used as cathodes for insertion of lithium, with the largest capacity achieved about 1.0 mol% of total vanadium. Cycling of the electrodes improves capacity, with insertion of lithium reaching 25 mol% of total vanadium. This gain in capacity results from further removal of alkali metal or ammonium ions from the electrode during the oxidation step of the cycling process.The results extend the range of composition of homogeneous phases in the system (NH4)2O–K2O–V2O4–V2O5. Keywords: alkali metal hexavanadates, electrochemical preparation.On a préparé des dépôts cohérents qui contiennent des cristaux orientés de MxM′4−xV6O16+δ, avec M, M′ = K, Rb, Cs ou NH4, 0,0 ≤ x ≤4,0 et 0,00 ≤ δ ≤ 0,13, par la méthode de voltammétrie cyclique sur des substrats divers et dans des solutions de metavanadates qui contiennent des cations des métaux alcalins ou d'ammonium seuls ou des combinations de tels ions. L'analyse chimique et la diffraction des rayons X ont démontré que les dépôts comprennent une série continue de cristaux mixtes basée sur les membres terminaux M4V6O16 et M′4V6O16.
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Koadri, Zainate, Azzedine Benyahia, Nadir Deghfel, Kamel Belmokre, Brahim Nouibat, and Ali Redjem. "Étude de l’effet du temps de traitement alcalin de fibres palmier sur le comportement mécanique des matériaux à base d’argile rouge de la région de M’sila." Matériaux & Techniques 107, no. 4 (2019): 404. http://dx.doi.org/10.1051/mattech/2019031.
Full textAbstract:
Ce travail s’inscrit dans le développement de matériaux locaux, telle que la fibre végétale (fibre de palmier) et l’argile rouge du sud Algérien, largement utilisées dans la préparation des briques, comme matériaux de construction rurale. Les fibres végétales possèdent des propriétés très intéressantes, elles sont : renouvelables, biodégradables et le rapport coût/légèreté faible. Leurs propriétés mécaniques sont très importantes. Cependant, le problème prédominant dans ce type de matériaux composites est la faible adhésion de l’interface matrice-fibre, attribuée probablement, à la nature de la surface et au caractère hydrophobe des fibres naturelles, conduisant ainsi, à des propriétés mécaniques faibles pour le composite envisagé. Le but de cette étude consiste à traiter la fibre de palmier par une solution basique d’hydroxyde de sodium (NaOH 4 % [m/v]) durant des périodes variables : 3, 7, 24 et 48 heures, afin d’améliorer l’adhésion interfaciale. Les résultats obtenus à partir des essais réalisés sur le composite renforcé par les fibres de palmier traitées durant 7 h ont montré une nette augmentation quant à la résistance, à la flexion et à la compression ; cette croissance est respectivement de l’ordre de 57 et 60 %, comparativement au composite renforcé par les fibres non traitées. On peut déduire que les fibres de palmier peuvent être considérées comme l’un des matériaux appropriés pour le renforcement de l’argile.
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Juarez, Cesar, Gerardo Fajardo, and Pedro Valdez. "Caractérisation microstructurale des fibres naturelles pour des matériaux composites à base de ciment." Canadian Journal of Civil Engineering 36, no. 3 (March 2009): 449–62. http://dx.doi.org/10.1139/l09-009.
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Le comportement mécanique des bétons renforcés de fibres naturelles dépend principalement de l’adhérence entre la fibre et la matrice de ciment. Cette adhérence a aussi une certaine influence sur le type d’endommagement de ces matériaux. Cette recherche a été menée sur des fibres naturelles de lecheguilla (Agave lecheguilla). Des essais chimiques, physiques et mécaniques tels que la détermination de la composition chimique, la morphologie, la porosité, l’absorption d’eau et les résistances à la traction et à la flexion ont été réalisés en utilisant ces fibres naturelles. Des observations à l’interface fibre–matrice de ciment ont aussi été effectuées à l’aide du stéréoscope pour évaluer l’effet du milieu alcalin et de différents rapports eau/ciment (E/C) sur la performance de mortier fibré. On a constaté que la résistance mécanique à la traction et à la flexion du matériau composite augmente, d’une part, avec l’augmentation de la longueur et, d’autre part, avec la diminution du volume de fibres utilisé. Le principal type de défaillance observée est l’arrachement des fibres. De plus, l’adhérence entre les fibres et la matrice de ciment est modifiée par les changements volumétriques et l’absorption d’eau relativement élevée. Néanmoins, cette adhérence peut être substantiellement améliorée en faisant un traitement superficiel des fibres à l’aide de solutions chimiques, comme le xylène, et en utilisant des faibles rapports E/C.
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Yu, Jianmei, Ivy N. Smith, and Nona Mikiashvili. "Reducing Ochratoxin A Content in Grape Pomace by Different Methods." Toxins 12, no. 7 (June 27, 2020): 424. http://dx.doi.org/10.3390/toxins12070424.
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Grape pomace (GP) is the residue of grapes after wine making and is a valuable source of dietary polyphenol and fiber for health promotion. However, studies found the presence of ochratoxin A (OTA) in GP at very high concentrations, which raises a safety issue in the value-added utilization of GP. This study evaluated the effects of thermal pressure, baking, acid and enzymatic treatments on OTA content in GP. Thermal pressure treatment was conducted with wet GP at 121 °C for 10–30 min in an autoclave; acid treatments were conducted with hydrochloric acid, acetic acid, citric acid, and lactic acid, respectively, at 50 °C for 24 h. Baking was conducted using a cookie model. For enzymatic treatment, purified OTA solution was treated with carboxypeptidase A, alcalase, flavourzyme, pepsin, and lipase, respectively, and the effective enzymes were selected to treat GP. Results show that autoclaving for 10–30 min reduced 19–80% of OTA, varying with treatment time and GP variety. The effectiveness of acid treatment was similar to that of autoclaving and varied with acid type and GP variety. Baking increased the detectable OTA. Among all tested enzymes, carboxypeptidase A was the most effective in reducing OTA, followed by lipase and flavourzyme, but their effects were significantly lower in GP samples.
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Vázquez, José Antonio, Javier Fraguas, Pío González, Julia Serra, and Jesus Valcarcel. "Optimal Recovery of Valuable Biomaterials, Chondroitin Sulfate and Bioapatites, from Central Skeleton Wastes of Blue Shark." Polymers 12, no. 11 (November 6, 2020): 2613. http://dx.doi.org/10.3390/polym12112613.
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The industrial filleting of blue shark (Prionace glauca) led to the generation of a large number of central skeletons of low interest to fishmeal plants handling such wastes. In this context, the present study describes the optimization of the hydrolysis process (pH 8.35, T 58 °C, 1% (v/w) of alcalase and t = 4 h) to produce chondroitin sulfate (CS) together with the recovery of bioapatites. Then, that hydrolysate was chemically treated with an optimal alkaline-hydroalcoholic-saline solution (0.48 M of NaOH, 1.07 volumes of EtOH and 2.5 g/L of NaCl) and finally purified by ultrafiltration-diafiltration (30 kDa) to obtain glycosaminoglycan with a purity of 97% and a productive yield of 2.8% (w/w of skeleton). The size of the biopolymer (CS) was of 58 kDa with prevalence of 6S-GalNAc sulfation (4S/6S ratio of 0.25), 12% of GlcA 2S-GalNAc 6S and 6% of non-sulfated disaccharides. Crude bioapatites were purified by pyrolysis and FT-Raman and XRD techniques confirm the presence of hydroxyapatite [Ca5(PO4)3(OH)], with a molar mass of 502.3 g/mol, embedded in the organic matrix of the skeleton. The mineralized tissues of blue shark are promising marine sources for the extraction of high value biomaterials with clinical application in bone and tissue regeneration and are still completely unexplored.
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Ying, Ma, Lin Li, and Sun Da-Wen. "Preparation of high Fischer ratio oligopeptide by proteolysis of corn gluten meal." Czech Journal of Food Sciences 26, No. 1 (February 19, 2008): 38–47. http://dx.doi.org/10.17221/1138-cjfs.
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A method to obtain an oligopeptide with high Fischer ratio is described. Corn gluten meal (CGM) was hydrolysed with Alcalase 2.4L using a two-step hydrolysis. In the first-step hydrolysis, the enzyme reaction conditions for hydrolysing CGM were optimised by using the orthogonal experimental design, while pH = 8.0, temperature = 55°C, enzyme to substrate ratio (3:97, w/w), and the substrate concentration = 5% were identified as the optimum conditions, under which up to 11.62% degree of hydrolysis (DH) could be obtained. The hydrolysate was then fractionated by ultrafiltration using a membrane with the molecular cutoff of over 10 kD at 20 kPa. For the second-step hydrolysis, the filtrate was adjusted to pH 6.0, then papain was added at 50°C and the mixture was maintained for 3 hours. The hydrolysate was obtained after inactivating papain and centrifuging. Then the salt (mainly NaCl) in the hydrolysate was removed with an ion exchange resin at the speed of 8 times bed volume per hour, and aromatic amino acids were removed through absorption by active carbon. By using Sephadex G-25 gel filtration chromatography, a peptide mixture with low molecular weights between 1000 and 1300 was obtained. Finally, tests on amino acid composition and free amino acid concentration of oligopeptide solution showed that the oligopeptide had a high Fischer ratio of 34.71 and the yield of 11.59%.
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Pęksa, A., and J. Miedzianka. "Amino acid composition of enzymatically hydrolysed potato protein preparations." Czech Journal of Food Sciences 32, No. 3 (June 11, 2014): 265–72. http://dx.doi.org/10.17221/286/2013-cjfs.
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We determine the effects of the technology of obtaining potato protein preparation and of different variants of enzymatic hydrolysis on the chemical and amino acid compositions of the hydrolysates obtained. Potato protein concentrates obtained through their thermal coagulation in potato juice with calcium chloride, calcium lactate or without salt addition were subjected to enzymatic hydrolysis using two commercial hydrolytic enzymes: endopeptidase (Alcalase) and exopeptidase (Flavourzyme). Chemical (contents of ash, total and coagulable protein) and amino acid compositions of the hydrolysates obtained were determined. On the ground of the findings it was stated that the type of potato protein preparation used and conditions of enzymatic modification influenced on the properties of the hydrolysates obtained. Preparations obtained during the study were characterised by similar chemical and amino acid compositions, whereas the preparation obtained through thermal coagulation with the use of calcium lactate contained insignificantly more protein and essential amino acids. The least liable to enzymatic hydrolysis was the preparation obtained by using calcium chloride, particularly when only endopeptidase was used. The application of endopeptidase enzyme enabled to obtain 60% of proteolysis efficiency and the addition of the second enzyme (exopeptidase) to the protein solution insignificantly increased the proteolysis efficiency (to ca 70%), mainly when the preparation coagulated with the use of calcium chloride was hydrolysed. Proteolysis of the protein preparations obtained with the use of two enzymes was more favourable, particularly due to the quantity of free amino acids in and amino acids composition of the hydrolysates.
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Pichayakorn, Wiwat, Jirapornchai Suksaeree, and Wirach Taweepreda. "Improved Deproteinization Process for Protein-Free Natural Rubber Latex." Advanced Materials Research 844 (November 2013): 474–77. http://dx.doi.org/10.4028/www.scientific.net/amr.844.474.
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Hev b1-14 type proteins in natural rubber latex (NRL) have been identified as allergens in immunogenic responses. Several methods have been developed to reduce these proteins from NRL such as enzyme treatment, centrifugation, creaming, simple or ultrasonic leaching, and chlorination. In this work, the improvement of deproteinization of NRL was developed using the combination of enzyme treatment and leaching processes. The fresh NRL was incubated with 0.2 phr proteolytic alcalase enzyme, and preserved with 2%v/v paraben concentrate in the presence of a 2%v/v sodium lauryl ether sulfate (SLES) as a surfactant at 37°C for 24 hours, and then centrifuged. The upper rubber mass was then leached for three times with either distilled water, a 1%v/v SLES solution, or a mixture of 1%v/v SLES and 2.5%v/v ethanol, and then finally re-dispersed in distilled water. It was found that the increasing process of leaching with either 1%v/v SLES or a mixture of 1%v/v SLES and 2.5%v/v ethanol had the higher efficacy to reduce the remained protein in deproteinized NRL (DNRL). The best deproteinized process was the enzyme treatment and followed by the three times leaching process with a mixture of 1%v/v SLES and 2.5%v/v ethanol, that could completely reduce the proteins in DNRL to 0%. This DNRL had the pH value, viscosity, dry rubber content, and total solid content of 7.41, 13.82 cps, 42.57%, and 44.63%, respectively. Its particle size was 626.23 nm with low polydispersity index of 0.16. The negative charge of SLES could increase the higher negative charge of DNRL to-63.20 mV that exhibited very good physical stability during storage. In conclusions, the combination of enzyme treatment and leaching process with both SLES and ethanol was successful to produce the protein-free DNRL. This DNRL could be further used for several applications including medical skin products.
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Silva, Priscila Christopoulos, Nathália Pereira Ferraz, Elen Aquino Perpetuo, and Yvan Jesús Olortiga Asencios. "OIL PRODUCED WATER TREATMENT USING ADVANCED OXIDATIVE PROCESSES: HETEROGENEOUS-PHOTOCATALYSIS AND PHOTO-FENTON." Journal of Sedimentary Environments 4, no. 1 (March 25, 2019): 99–107. http://dx.doi.org/10.12957/jse.2019.40991.
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The Oil Produced Water (OPW) is an effluent produced during the oil extraction process. Owing to its complex composition and toxicity it must be treated by wastewater treatment technologies. However, traditional facilities may be unable to remove all the anthropogenic or naturally occurring compounds. This can result in their discharge to surface water and ultimately affecting the sedimentary environment. The present work shows the application of two Advanced Oxidative Processes (AOPs), Photocatalysis and Photo-Fenton to treat two kinds of effluents: phenolic solution made in seawater, and a real sample of OPW from Rio Grande do Norte, Brazil. Two commercial catalysts were used: TiO2 (for Heterogeneous-Photocatalysis process), and FeSO4.7H2O (for Photo-Fenton process). The catalysts were characterized by X-Ray Diffraction Analysis (XRD), and Diffusive Reflectance Spectroscopy (DRS). In the two AOPs the following parameters were evaluated: initial pH of effluent (acid, neutral and alkaline), presence of H2O2 (0.3%v/v) and time under ultra-violet (UV) irradiation (254nm); aiming to find the suitable conditions for OPW treatment. The results showed an efficiency of 99% for phenol removal, despite the high content of salts present in seawater. In the treatment of the two effluents by the AOPs, the reaction reached chemical equilibrium in 1 h under UV irradiation (254 nm); the best pH to treat the effluents was pH 7, in the presence of H2O2 (0.3%v/v) and by increasing temperature to 75°C (in the case of the real sample of OPW). The results of this work show that the two studied AOPs can be used in the oil industry, for OPW treatment and to treat effluents (with high salinity) contaminated with phenol, to remove organic compounds in order to reduce their toxicity, and consequently assist towards a better quality of the sedimentary environment. The best results were obtained by the Photo-Fenton process. TÍTULO: TRATAMENTO DE ÁGUA PRODUZIDA DE PETRÓLEO USANDO PROCESSOS OXIDATIVOS AVANÇADOS: FOTOCATÁLISE HETEROGÊNEA E FOTO-FENTON RESUMOA Água Produzida por Petróleo (OPW) é um efluente gerado durante o processo de extração de óleo. Devido à sua composição complexa e toxicidade, deve ser tratada por tecnologias de tratamento de águas residuais. No entanto, as instalações tradicionais podem não ser capazes de remover todos os compostos antropogênicos ou de ocorrência natural, podendo resultar na descarga de efluentes contaminados por óleo em águas da superfície e, em última análise, afetar o ambiente sedimentar. O presente trabalho mostra a aplicação de dois Processos Oxidativos Avançados (AOPs), Fotocatálise-Heterogênea e Foto-Fenton para tratar dois tipos de efluentes: solução fenólica em água do mar e uma amostra real de OPW do Rio Grande do Norte, Brasil. Foram utilizados dois catalisadores comerciais: TiO2 (para o processo Fotocatálise Heterogênea) e FeSO4.7H2O (para o processo Foto-Fenton). Os catalisadores foram analisados por Difração de Raios-X (XRD) e Espectroscopia de Reflexão Difusiva (DRS). Nos dois AOPs foram avaliados os seguintes parâmetros: pH inicial do efluente (ácido, neutro e alcalino), presença de H2O2 (0,3% v/v) e tempo sob irradiação ultravioleta (UV) (254nm); com o objetivo de encontrar as condições adequadas para o tratamento de OPW. Os resultados mostraram uma eficiência máxima de 99% na remoção de fenol, apesar do alto teor de sais presentes na água do mar. No tratamento dos dois efluentes pelos AOPs, a reação atingiu o equilíbrio químico em 1 h sob irradiação UV (254 nm); o melhor pH para tratar os efluentes foi pH 7, na presença de H2O2 (0,3% v/v) e aumentando a temperatura para 75 °C (no caso da amostra real de OPW). Os resultados deste trabalho mostram que as duas AOPs estudadas podem ser utilizadas na indústria petrolífera, para tratamento de OPW e para tratar efluentes (com alta salinidade) contaminados com fenol, para remover compostos orgânicos a fim de reduzir a sua toxicidade e, consequentemente, manter a qualidade do ambiente sedimentar. Os melhores resultados foram obtidos pelo processo Foto-Fenton. PALAVRAS-CHAVE: Contaminantes. Tratamento. Água Produzida de Petróleo. Água marinha. Fotocatálise Heterogênea. Foto-Fenton. Processos Oxidativos Avançados (AOPs).
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Sadiev, F. F., Yu I. Shirokova, and G. K. Paluashova. "Study of the reclamed effect of the “Biosolvent” preparation on alcaline soils when washing and irrigating." Scientific Journal of Russian Scientific Research Institute of Land Improvement Problems, no. 1 (2021). http://dx.doi.org/10.31774/2222-1816-2021-11-1-24-46.
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Purpose: to study the effect of the desalinator “Biosolvent” on the processes of soil desalinization during the washing and vegetative irrigation. Materials and methods. The research was carried out in Syrdarya region of Uzbekistan at experimental sites. The objects of research are saline soils of irrigated fields under cotton. Field observations and soil analyzes were carried out according to generally accepted methods: granulometric composition – by sedimentation method, salinization – by electrical conductivity and water extract, phenological observations – by the SoyuzNIKHI method. Statistical processing was performed in Excel. Results: when spraying soil of strong and medium salinity with 10% Biosolvent preparation before washing and watering cotton, the leaching of ions toxic to plants is higher compared to conventional washing, more harmful ions are washed out: chlorine by 35–42 %, sulfates by 13–16 %, calcium by 21–28 %, sodium by 21–23 %. When treating the surface of furrows with a 10% solution before watering cotton, a more significant decrease in the content of harmful salts was also found than with conventional irrigation. Salts were washed out along the treated furrows by 18–23 % more, and chlorine, sulfate and calcium ions, respectively, by 17, 18 and 14 %. As a result of improved conditions in the root zone of cotton, an increase in yield of 7.5 c/ha was obtained. Conclusions. To increase the efficiency of washing saline soils and regulate the salinity of the root layer of soil during the growing season, it is advisable to apply preliminary spraying of the soil with a 10% solution of the “Biosolvent” preparation. The use of Biosolvent in comparison with traditional technologies contributes not only to a decrease in soil salinity, positive changes in chemical composition of salts in the soil, but also to an increase in cotton yield.
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"Production of fish seasoning powder from snakehead meat (Channa striata) by applying Alcalase and Flavourzyme enzyme mixture." Journal of Agriculture and Development 19, no. 02 (April 29, 2020): 43–49. http://dx.doi.org/10.52997/jad.6.02.2020.
Full textAbstract:
Fish hydrolysate was produced from snakehead meat by applying an enzyme mixture consisting of Alcalase and Flavourzyme with a ratio of 1:3; hydrolysis temperature 55oC; pH 6.5 - 6.9. The results showed that the ratio of enzyme mixture to fish meat of 0.2% and hydrolysis time of 26 h were the optimal hydrolysis conditions. Fish hydrolysate had highest peptide content (26.4 g/L) and nitrogen amino acid content (10.6 g/L), and lowest nitrogen ammonia content (0.257 g/L). Sensory score, protein content, recovery yield and moisture content of fish seasoning powder were 18.9; 17.1%; 42.5% and 4.88%, respectively by mixing radish solution and fish hydrolysate at the ratio of radish solution to fish hydrolysate of 25%:40% and drying at 60oC for 72 h. The product still remained good sensory quality. The moisture content and total aerobic bacteria of product were at acceptable level after 4 weeks stored at ambient temperature.
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Bilal, Essaïd. "GEOCHIMIE ET CONDITIONS DE CRISTALLISATION DES MINERAUX DU GROUPE DE L’HELVITE." Geonomos, December 1, 1994. http://dx.doi.org/10.18285/geonomos.v2i2.221.
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Minerais de berílio (berilo, fenaquita e helvita) são constituintes de veios a quartzo-muscovita e veios de siderofilita. Noalbitito, somente a fenaquita e a helvita estão presentes. Este trabalho refere-se à ocorrência do maciço de Sucuri (Goiás, Brasil),às helvitas dos skarns de Costabonne, França e às helvitas de veios a quartzo-wolframita de Dajishan, China.O estudo paragenético, geoquímico e experimental de helvitas (Mn, Zn, Fe)8 Be6 Si6 O24 S2 analisadas leva à uma novadefinição da fórmula estrutural deste mineral que, por analogia àquela da hauyna é (Mn, Zn, Fe)8-x Nax Be6 Si6 O24 S2-x Clx. Àssubstituições clássicas Zn-Fe-Mn, se ajuntam as substituições do tipo: Cl-S e Be-Li. O Li substitui o Be na estrutura da helvita, odéficit de carga elétrica resultante é compensado pela introdução de Na na estrutura. A substituição Cl-S foi confirmada porestudo experimental. Restrições de ordem geoquímica desempenham um importante papel na introdução de terras raras na estruturada helvita, de modo que num ambiente francamente alcalino, a helvita concentra mais facilmente as terras raras pesadas.A danalita (pólo ferrífero da helvita) cristaliza-se em um domínio de fugacidade do enxofre e do oxigênio muito limitado eque corresponde ao domínio de estabilidade da pirrotita. A genthelvita (pólo zincífero da helvita) é estável em um extensodomínio de fugacidade do enxofre e oxigênio. Ao contrário, a helvita (pólo manganesífero da série) se desenvolve em umdomínio de fugacidade de oxigênio moderado e de fugacidade do enxofre suficientemente extenso e comparável àquele dagenthelvita.A formação de mineralização de berílio de composição variável nos skarns resultaria, seja da sucessão de soluções tardiasricas em sílica (se a razão Si/Al é alta, a fenaquita ou a helvita se cristalizam) atuando sobre a paragênese aluminosa (musgravita,crisoberilo) formada precocemente, seja da fraca migração de Al em relação a Si. Neste último caso, a paragênese aluminosa(musgravita, crisoberilo) terá uma distribuição limitada. A atividade da alumina desempenha um papel essencial na variação dacomposição dos minerais de berílio. Se ela é fraca, a fenaquita e/ou helvita são estáveis e se ela é forte o berilo e o crisoberilo oua musgravita são estáveis.Entretanto, o aumento da atividade de alguns elementos (Ca, Mn, Fe, Zn ou alcalinos) tendendo a incorporarem alumina nasgranadas ou nos feldspatos será um fator desfavorável para a formação do berilo. Assim, a helvita é um mineral tipicamenteestável nos skarns cálcicos e se associa à fenaquita nas rochas submetidas ao metassomatismo alcalino. Por outro lado, o beriloaparece normalmente em condições onde um fluido ácido se separa de líquidos graníticos muito evoluidos (aplopegmatito).A genthelvita é estável sob condições alcalinas e oxidantes. ABSTRACT: Beryllium-bearing minerals (beryl, phenacite, helvite) are present in the quartz-muscovite and siderophyllite veins. In thealbitites, only phenacite and helvite (Fe,Zn,Mn)8Be6(SiO4)6S2 are found. Besides the Sucuri deposits, we studied also helvitesfrom the northern skarn of Costabonne (France) and from quartz-wolframite veins of Dajishan (China). Paragenetic and geochemicaldata on helvites from these three occurences lead to propose a new structural formula:(Mn,Zn,Fe)8-xNax Be6 Si6 O24 S2-xClx, analogous to that of haüyne.To the standard substitutions Zn-Fe-Mn in helvite, we may add substitutions like Cl-S and Be-Li. Lithium probably replacesberyllium in the structure of helvite, the charge deficit being balanced by the entry of sodium. Crystal chemical constraints clearlyplay an important role for the incorporation of REE in helvite, but, in an alkaline context, helvite shows preference for heavyREE.Danalite (the Fe end-member of helvite) is stable in a very limited domain of fS2 and fO2, which coincides with that ofpyrrhotite. Genthelvite (Zn end-member) is stable in a large domain of fS2 and fO2. On the other hand, helvite (Mn end-member)is stable in conditions of moderate fO2 and for a range of fS2 relatively large compared to that of genthelvite. In Sucuri,Goiás,Brazil, the ilmenites of the internal zone (where genthelvite is found) contain 16% of hematite, whereas those of the external zonecontain no hematite. The zonations observed within the helvite crystals (genthelvite core and danalite border) reflect the variationsof fS2 and fO2.The compositional variations of the beryllium minerals observed in skarns may be explained by the following processes:- either a late arrival of silica-rich solutions (high Si/Al ratio, presence of phenacite or helvite) within early formed aluminarichparageneses (musgravite, chrysoberyl),- or a limited mobility of Al relatively to Si, which would induce a limited extension of the aluminous parageneses (musgravite,chrysoberyl).The activity of aluminium plays an essential role in the stability of the beryllium minerals: phenacite and/or helvite are stablewhen it is low, and beryl, chrysoberyl or musgravite when it is high. However, the increase of activity of other elements (Ca, Mn,Fe, Zn, alkalis) that would induce the formation of minerals incorporating alumina (garnet or felspars) would be unfavourable tothe formation of beryl. Helvite is thus typically stable in calcic skarns, and it is associated with phenacite in the rocks submittedto alkaline metasomatism. Beryl, on the contrary, normally appears when acidic fluids separates from highly evolved graniticmagmas (aplopegmatitic stage).The zonation of helvite crystals in albitites (genthelvite core, danalite border) reflects the decrease of alkalinity of the fluids.This zonation on the crystal scale is also observed on the outcrop scale: helvite composition varies from Ge64Da10He26 in theinternal zone to Ge23Da50He26 in the external zone. The same variation is observed in an albitized siderophyllite vein, fromGe25Da42He33 in a slightly albitized zone to Ge55Da39He22 in a highly albitized one. The formation of genthelvite is favoured, ascompared with the other members of the helvite group, by alkaline conditions.The compositional variations of helvite in the Sucuri massif would result from variations in fS2 and fO2 in the fluids. Genthelviteis stable under alkaline and oxydizing conditions.
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Minh, Thuy Le Thi, Tran Thanh Truc, and Kazufumi Osako. "The effect of deproteinization methods on the properties of glucosamine hydrochloride from shells of white leg shrimp (Litopenaeus vannamei) and black tiger shrimp (Penaeus monodon)." Ciência Rural 52, no. 1 (2022). http://dx.doi.org/10.1590/0103-8478cr20200723.
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ABSTRACT: The effect of methods to remove protein content on the properties of glucosamine hydrochloride from the shells of white leg shrimp (Litopenaeus vannamei) and black tiger shrimp (Penaeus monodon) was investigated. Chitin from shrimp shells was obtained by demineralization in 6% HCl for 12h, deproteinization by two different methods (first group soaked in 8% NaOH for 36h and second group treated in Alcalase enzyme at the concentration of 0.2% for 36h). Two group samples were converted to glucosamine hydrochloride by soaking in 36.76% HCl solution for 5h at 85 °C. The results of fourier transform infrared spectroscopy (FTIR), solubility and recovery yield analysis showed that deproteinization methods did not significantly affect the properties of glucosamine hydrochloride. However, glucosamine hydrochloride from white leg shrimp shells contained higher recovery yield and solubility than black tiger shrimp shells.
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Guerra-Almonacid, Carlos Martín, Juan Gabriel Torruco-Uco, Walter Murillo-Arango, Jonh Jairo Méndez-Arteaga, and Jesús Rodríguez-Miranda. "Effect of ultrasound pretreatment on the antioxidant capacity and antihypertensive activity of bioactive peptides obtained from the protein hydrolysates of Erythrina edulis." Emirates Journal of Food and Agriculture, May 8, 2019, 288. http://dx.doi.org/10.9755/ejfa.2019.v31.i4.1938.
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The aim of this research was to evaluate the effect of ultrasound pretreatment on enzymatic hydrolysis with Flavourzyme® and Alcalase® enzymes and the ACE-inhibitory activity and the antioxidant capacity of protein hydrolysates of Erythrina edulis. A protein concentration of 78.8% was obtained after sonicating the protein solutions (10%, w/v) for 10 min at 80 kHz and 100% amplitude. The ultrasonic pretreatment (UP) increased the degree of hydrolysis (47.7%) up to 70 min, the IC50 values in both samples [with (UP) and without pretreatment (WP)] were 100 μg/mL, and the UP samples presented the highest percentage of inhibition at 57.3%. The UP hydrolysates showed the highest (p < 0.05) antioxidant (ABTS*) and radical (DPPH*) - scavenging activities, with IC50 values ranging from 64.52 to 77.62 μg/mL and from 151.13 to 173.22 μg/mL, respectively. In SDS-PAGE, the hydrolysates UP exhibited low molecular weight bands (8 - 20 kDa). The results of both, antioxidants and antihypertensive activities obtained in vitro, showed a higher percentage of activity for the peptides obtained after pretreatment with ultrasound than for those obtained without the use of ultrasound prior to enzymatic hydrolysis.
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Zubair, Marili Funmilayo, Olubunmi Atolani, Sulyman Olalekan Ibrahim, Olubunmi Stephen Oguntoye, Rukayat Abiodun Oyegoke, and Gabriel Ademola Olatunji. "Fatty acids Composition, Antimicrobial Potential and Cosmeceutical Utilization of Prosopis africana Seed Oil." Journal of the Mexican Chemical Society 62, no. 3 (April 22, 2019). http://dx.doi.org/10.29356/jmcs.v62i3.435.
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Abstract. The physicochemical properties, fatty acids profile, antimicrobial activity and soap potential of the seed oil of Prosopis africana were examined. The prepared natural antiseptic soap was absolutely devoid of all forms of synthetics such as alkaline, antimicrobial agents, preservatives, colourants and fragrances. The seed had an oil yield of 4.98% while the saponification, acid, free fatty-acids and iodine values were found to be 11.60 ± 0.54 mgKOH/g, 16.96 ± 0.57 mgKOH/g, 14.60 ± 0.45% oleic and 145.47 ± 0.66 I2 100 g-1 of the oil respectively. The GC-MS result of the prepared fatty acid methyl ester (FAMEs) indicated the presence of oleic acid (33.67%), a monounsaturated fatty acid as the most prominent fatty acid in the oil, followed linoleic acid (18:2), a polyunsaturated acid making up 31.92% of the oil. Palmitic acid (24.96%) is the most abundant saturated fatty acid while stearic acid and valeric acid makes up (7.3%) and (1.96%) respectively. The antimicrobial activity of the oil tested against ten strains of organisms which include: Streptococcus aureus, Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Salmonella typhi, Klebsiella pneumoniae, Candida albicans, Penicillium notatum, Rhijoptius stoloniter and Aspergillus niger showed good activity. The Minimum Inhibition Concentration (MIC) values obtained for the oils ranges from 31.25 to 125 mg/mL against all the test organisms and within the range 0.125- 0.5 mg/mL for the prepared soap. The physicochemical analysis of the P. africana soap was comparable to commercial antiseptic soaps. The result indicated that quality renewable natural antiseptic soaps ccould be obtained from P. africana seed oil. The result confirms that soaps made from natural lye (alkaline solution) has the capacity to replace existing commercial antiseptic soaps made of synthetic sodium or potassium hydroxides, antimicrobial agents, artificial preservatives and colourants which partly accounts for environmental pollution, increase in antimicrobial resistance and endocrine disruption. The adoption of this green antiseptic soap synthesis technique utilising underexplored P. africana seed oil can help mitigate the negative environmental impact of non-biodegradable synthetic reagents. Resumen. Se examinaron las propiedades fisicoquímicas, el perfil de ácidos grasos, la actividad antimicrobiana y el potencial de jabón de la semilla de aceite de Prosopis africana. El jabón antiséptico natural preparado carecía absolutamente de todas las formas de sintéticos tales como agentes alcalinos, antimicrobianos, conservantes, colorantes y fragancias. La semilla tuvo un rendimiento de aceite de 4.98%, mientras que los valores de saponificación, ácido, ácidos grasos libres y yodo fueron 11.60 ± 0.54 mgKOH / g, 16.96 ± 0.57 mgKOH / g, 14.60 ± 0.45% oleico y 145.47 ± 0.66 I2 100 g-1 del aceite respectivamente. El resultado de GC-MS del metil éster de ácido graso preparado (FAME) indicó la presencia de ácido oleico (33,67%), un ácido graso monoinsaturado como el ácido graso más prominente en el aceite, seguido del ácido linoleico (18: 2), Ácido poliinsaturado que constituye el 31,92% del aceite. El ácido palmítico (24,96%) es el ácido graso saturado más abundante, mientras que el ácido esteárico y el ácido valérico constituyen (7,3%) y (1,96%) respectivamente. La actividad antimicrobiana del aceite analizada contra diez cepas de organismos que incluyen: Streptococcus aureus, Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Salmonella typhi, Klebsiella pneumoniae, Candida albicans, Penicillium notatum, Rhijoptius st. Los valores de Concentración de inhibición mínima (CIM) obtenidos para los aceites varían de 31.25 a 125 mg / ml frente a todos los organismos de prueba y se encuentran dentro del rango de 0,125 a 0,5 mg / ml para el jabón preparado. El análisis fisicoquímico del jabón de P. africana fue comparable al de los jabones antisépticos comerciales. El resultado indicó que se podrían obtener jabones antisépticos naturales renovables de calidad a partir del aceite de semilla de P. africana. El resultado confirma que los jabones hechos de lejía natural (solución alcalina) tienen la capacidad de reemplazar los jabones antisépticos comerciales existentes hechos de hidróxidos de sodio o potasio sintéticos, agentes antimicrobianos, conservantes artificiales y colorantes que en parte representan la contaminación ambiental, el aumento de la resistencia antimicrobiana y la endocrina. ruptura. La adopción de esta técnica de síntesis de jabón antiséptico verde que utiliza aceite de semilla de P. africana poco explorada puede ayudar a mitigar el impacto ambiental negativo de los reactivos sintéticos no biodegradables.
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"Reciclaje de PET: Evaluación de la eficiencia de separación del contaminante PVC." Revista ECIPeru, January 10, 2019, 8–14. http://dx.doi.org/10.33017/reveciperu2011.0002/.
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Reciclaje de PET: Evaluación de la eficiencia de separación del contaminante PVC PET recycling: Evaluation of the efficiency of contaminant separation PVC Anie Karina da Rosa Oliveira, Carlos Henrique Michelin Beraldo y Ruth Marlene Campomanes Santana Universidade Federal do Rio Grande do Sul. Av. Bento Gonçalves 9500, Agronomia, Porto Alegre, Brasil DOI: https://doi.org/10.33017/RevECIPeru2011.0002/ RESUMEN Uno de los plásticos convencionales más utilizados por la sociedad es el PET (polietileno tereftalato), ampliamente utilizado en la producción de botellas para bebidas carbonatadas y de agua mineral. Otro plástico que también es utilizado para esa aplicación, pero en menor cantidad es el PVC, (policloruro de vinilo). El reciclaje de polímeros es importante y ventajosa pero existen también desventajas como el gran volumen de residuo generado y el agotamiento de los rellenos sanitarios, entre otros. Existen diversas técnicas de separación de materiales poliméricos, siendo el más usado, la separación por diferencia de densidades (gravedad) pues es uno de los métodos más fáciles y barato de ser aplicado; el gran problema de ese método es la separación de materiales con densidades semejantes, como es el caso del PET y PVC, entre 1,30-1,37 g/cm3 imposibilitando la separación de los mismos por esa técnica. El gran problema es la contaminación de PVC en el PET, pues ocasiona manchas en el PET transparente así como su degradación. En este sentido, el objetivo de este estudio es determinar una metodología más eficiente y viable económicamente de separación de PVC en PET a través del método de flotación. El primer paso fue tratar las muestras con solución alcalina de NaOH en temperaturas de 25oC y 80oC (tratatamento termoquímico), con el objetivo de modificar la superfície del PET, y con esto aumentar a su energia superfícial (ES). Para la determinación de la ES fueron realizadas las medidas de ángulo de contacto usando un goniómetro y en el ensayo de flotación fueron utilizadas soluciones de tensoativo MIBC y en diferentes pHs. Resultados de las condiciones de tratamiento termoquímico mostraron que la solución con 1% de NaOH y temperatura de 80 oC fue la que presentó mayores ES en la superficie del PET. En relación a la separación del PVC por flotación, los resultados mostraron que el medio más eficiente de separación es el básico, llegando a alcanzar un 85% de separación de PVC en solución de tensoactivo de 0,25% y de 87% en solución de tensoactivo de 0,50%. Descriptores: PET, PVC, resíduo plástico, reciclaje, separación, tratamiento químico. ABSTRACT One of plastics conventional but used by the society is the PET (tereftalato polythene), widely used in the production of bottles for carbonated drinks and mineral water. Another plastic that also is used for that application, but in smaller amount is the PVC, (vinyl polychloride). The polymer recycling is important and advantageous, but it also exists disadvantages like the great volume of generated remainder, exhaustion of the sanitary fillings, among others. Diverse techniques of separation of polymeric materials exist, being the most used, the separation by difference of densidades (gravity), due to that is one of the methods but easy and cheap to be applied, the great problem of that method is the separation of materials with similar densidades, as it is the case of PET and PVC, between 1.30-1.37 g/cm3 disabling the separation of the same by that technique. The great problem is the contamination from PVC in the PET due to that it causes spots in the PET transparent as well its degradation. In this sense, the objective of that study is to determine the most efficient and economically viable methodology of separation from PVC in PET through flotation method. The first step was the treatment of the samples with alkaline solution of NaOH, 1.0 and 4.0% in mass, at temperatures of 25oC and 80oC, and times of treatment of 15 and 30 minutes. For the determination of the surface energy was realised the measures of contact angle using a goniometer. In the flotation test, solutions of MIBC of 0.25 and 0.5% were used and different pHs (acid, basic and neutral). Results of the conditions of thermo-chemical treatment showed that the solution with 1% of NaOH and 80 oC was the one that presented higher surface energies in the surface of the PET. In relation to the separation of the PVC by flotation, results showed that the condition more efficient was the basic, getting to reach a 85% of separation of PVC in solution of tensoactivo of 0.25% and 87% in solution of tensoactivo of 0.50%. Keywords: PET, PVC, plastic waste, recycling, separation, chemical treatment.