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Статті в журналах з теми "Nitric acid extract"
1
Handani, Sri, Sri Wildani, and Emriadi. "PENGARUH INHIBITOR EKSTRAK DAUN INAI (lawsonia inermis) TERHADAP LAJU KOROSI BAJA ST. 37 DIUKUR DENGAN METODE PENGURANGAN MASSA." Jurnal Riset Kimia 4, no. 1 (February 12, 2015): 73. http://dx.doi.org/10.25077/jrk.v4i1.148.
Повний текст джерелаАнотація:
Vol. 4, No. 1ABSTRACT The corrosion tests and micro structure analysis of St. 37 steel had been investigated. These investigation were conducted in nitric acid (HNO3). The range of concentration added was from 0-0.5 N with extract of henna leaves as inhibitors. The method used was losing mass by measuring loss mass of steel before and after corrosion. The boiling method was used to get the extract of henna leaves. Optical photo Carton Stereo Trinokuler were used for micro structure. Corrosion rate can be reduced by adding inhibitor and inhibition efficiency is measured if its ability to suppress corrosion. The result of the immersion tests show that the inhibition efficiencies are different on 0-0.5 N concentration are 81.96 %, 78.92 %, 53.74 %, 44.85 %, 44.45 % and 39.65 %. Addition of 50 g/1000 mL extrac of henna leaves results in the highest efficiency for HNO3 environment. The photo showed the surface structure of steel before corrosion, in layer with extract of henna leaves and after corrosion in medium nitric acid. Keywords: Corrosion rate, Inhibition efficiency, Extract of henna leaves, Nitric acid.
2
Nguyen, Huong Thi Diem, Son Hong Phan, Huong Dang Thien Bui, Hoai Thi Cam Ho, and Mai Thi Thanh Nguyen. "BIOACTIVITIES AND CHEMICAL CONSTITUENTS OF A VIETNAMESE MEDICINAL PLANT VANG SE JASMINUM SUBTRIPLINERVE BLUME." Science and Technology Development Journal 15, no. 3 (September 30, 2012): 37–44. http://dx.doi.org/10.32508/stdj.v15i3.1815.
Повний текст джерелаАнотація:
From the total crude ethanol extract of Jasminum subtriplinerve Blume.’s leaves and stems, (Vang se in Vietnamese), four extracts were obtained by partitioning with petroleum ether, cloroform, ethyl acetate and n-butanol solvents. These four extracts were tested for antioxydative activity, determined using the DPPH●.radical scavenging and nitric oxyde-inhibitory assay. All the extracts showed antioxidative activity except the petroleum ether extracts. Among the crude extracts, the acetate ethyl extract was the most potent extract in both assays with the SC50 values of 8.2 μg/mL and 80.7 μg/mL, respectively. From the VS3 substract, three compounds were isolated, including two acids namely 3,4- dihidroxybenzoic acid (1), 3,4,5-trihidroxybenzoic acid (2) and a glycoside, verbascoside (3). The structure of those compounds was elucidated by spectrometric methods IR, MS, LC-MS, 1D-NMR, and 2D-NMR.
3
Pakdil, N. B., and A. Filibeli. "Effects of organic and inorganic acids on phosphorus release from municipal sludge." Water Science and Technology 56, no. 9 (November 1, 2007): 87–94. http://dx.doi.org/10.2166/wst.2007.707.
Повний текст джерелаАнотація:
This paper reports on the effects of inorganic acids (sulphuric acid, hydrochloric acid, nitric acid) and organic acids (citric acid, oxalic acids) for phosphorus recovery from sludge and struvite precipitation results. It was observed that both inorganic acid and organic acids were effective at phosphorus release. The studies on precipitation of released phosphorus from sludge as magnesium ammonium phosphate (struvite) were also done using nitric and oxalic acids. Phosphorus and heavy metals of leachate were analyzed before and after precipitation. It was observed that heavy metal concentrations in the extracted samples decrease after precipitation. Precipitation was accomplished by using extract derived with nitric acid; however, in oxalic acid applications, it was not achieved. When the chemical constituents of the dried material were examined oxygen, sodium and nitrogen were found to be the major elements.
4
Abu, T., O. O. Ogbole, and E. O. Ajaiyeoba. "Radical Scavenging Activity, Brine Shrimp Lethality Assay and HPLC Analysis of Methanol Extracts of Secamone afzelii." Nigerian Journal of Pharmaceutical Research 17, no. 2 (February 11, 2022): 233–44. http://dx.doi.org/10.4314/njpr.v17i2.9.
Повний текст джерелаАнотація:
Background: Medicinal plants produce several phytochemicals with strong free radical scavenging activities. Objectives: To evaluate radical scavenging activity, brine shrimp toxicity and high-performance liquid chromatography (HPLC) analysis of the methanol extracts of Secamone afzelii (SA) leaves and Ceiba pentandra (CP) stem-bark.Materials and methods: The leaves of SA and CP stem-bark were extracted with methanol and the total phenolic content (TPC) of the extracts was determined and expressed as gallic acid equivalents (GAE). The extracts were evaluated for their nitric oxide scavenging activity, antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, toxicity using brine shrimp lethality assay (BSLA) and phytochemical constituents using HPLC. Results: The TPC in SA extract was 21.26±1.29 while that of CP extract was 95.31±8.71 mg GAE. The SA and CP extracts showed antioxidant activity by DPPH with IC50 of 97.60 and 22.35 μg/mL as compared to ascorbic acid (1.4±0.34) and gallic acid (2.8±0.78) Similarly, the extracts showed nitric oxide scavenging activity of 22.50±1.3 and 5.40±0.3 µg/mL respectively compared to gallic acid with IC50 value of 1.1±0.1 µg/mL. In BSLA, SA extract had LC50 value of >1000 μg/mL while CP extract and Cyclophosphamide (standard) had LC50 value of <1000 μg/mL. HPLC analysis suggested that 8-β-L-arabinofuranosyl-6-β-D-glucopyranosylapigenin, kaempferol-3-0-glucoside, kaempferol-3-O-(6''-malonyl-glucoside), kampferol-3-O-rhamnoglucoside and palitantin were the major components in SA extract while the major components in CP extract were lateritin/beauvericin, procyanidin B2, pavetannin, (-)-catechin and genistein-8-C-glucoside .Conclusion: The results demonstrate the free radical scavenging properties of SA and CP extracts which could be attributed to the presence of phenolic compounds.
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Choi, Jieun, Young Yun Jung, In Jin Ha, Seung Ho Baek, Zhiyun Zhang, Soo-Yong Kim, Yejin Hong, et al. "In Vitro Anti-Inflammatory and Skin Moisturizing Properties of Pilea martini (Levl.) Hand.-Mazz. Extracts." Natural Product Communications 15, no. 11 (November 2020): 1934578X2096786. http://dx.doi.org/10.1177/1934578x20967866.
Повний текст джерелаАнотація:
The in vitro anti-inflammatory and skin moisturizing activities of Pilea martini (Levl.) Hand.-Mazz. were investigated on lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages and human immortalized keratinocytes. Chromatographic analysis was performed to identify the chemical composition of the extracts. Pilea martini extracts significantly suppressed LPS-induced nitric oxide, prostaglandin E2, interleukin 6, and tumor necrosis factor α production in dose-dependent manners. In addition, the extracts inhibited LPS-induced inducible nitric oxide synthase and cyclooxygenase-2 proteins and their mRNA expression through causing a downregulation of nuclear factor-κB, activator protein 1, and mitogen-activated protein kinase signaling cascades. The extracts increased the production of hyaluronic acid levels and enhanced the expression levels of both filaggrin and serine palmitoyltransferase regulation. Liquid chromatography-mass spectroscopy analysis showed that the extracts contained 6 different compounds (malic acid, tryptophan, chlorogenic acid, caffeic acid, p-coumaric acid, and isoquercetin) that may contribute to their bioactivities. Taken together, Pilea martini extract showed remarkable promise as an anti-inflammatory and moisturizing agent.
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Pranaya P and AkilaDevi D. "An Investigation of free radical scavenging activity of various extracts of Olax scandens (family Olacaceae)." International Journal of Research in Pharmaceutical Sciences 11, no. 1 (January 9, 2020): 397–402. http://dx.doi.org/10.26452/ijrps.v11i1.1833.
Повний текст джерелаАнотація:
Olax scandens Roxb. (family Olacaceae) Available in throughout tropical India. The current study, aerial parts of different extracts of Olax scandens by different in-vitro methods. The antioxidant activity was evaluated by Hydroxyl radical scavenging activity(OH radical), Nitric oxide radical scavenging activity(NO radical), and total antioxidant activity (Phosphomolybdic acid method) with reference standard Ascorbic acid. An IC50 value was originated that methanolic extracts of Olax scandensis more efficient in Hydroxyl radical scavenging activity, Nitric oxide radical scavenging, total antioxidant activity than that of EA and petroleum ether extract. The methanolic extracts of Olax scandens & ascorbate exhibited antioxidant potential possessing IC50 253µg/ml & 135µg/ml (NO radical ), 205µg/ml & 57µg/ml (Phosphomolybdic acid method), 265µg/ml & 65µg/ml (OH radical) respectively. But when compared to all the three extracts with ascorbate (standard), the methanolic extract of the Olax scandens showed a better result. Moreover, the results were observed in a concentration-dependent manner. Invitro antioxidant studies obviously showed that methanolic extracts of Olax scandens have better antioxidant activity. These results indicate that aerial parts of methanolic concentrates Olax scandals could serve as a natural antioxidant, which may be useful to prevent free radical-induced diseases.
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Seo, Chang-Seob, Hye-Sun Lim, Soo-Jin Jeong, Hyekyung Ha, and Hyeun-Kyoo Shin. "HPLC-PDA Analysis and Anti-inflammatory Effects of Mori Cortex Radicis." Natural Product Communications 8, no. 10 (October 2013): 1934578X1300801. http://dx.doi.org/10.1177/1934578x1300801027.
Повний текст джерелаАнотація:
Mori Cortex Radicis (MCR, Moraceae) is used traditionally in the treatment of jaundice, hematemesis, edema, and pollakisuria in Korea. In this study, the anti-inflammatory effects of MCR extract were investigated using RAW 264.7 cells. The simultaneous analysis of five components present (neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid, caffeic acid, and p-coumaric acid) in the MCR extract was performed using high-performance liquid chromatography (HPLC) coupled with photodiode array (PDA) detection. We determined the effects of MCR extract and its components on the production of nitric oxide (NO), prostaglandin E2 (PGE2), and mRNA expression of cyclooxygenase-2 (COX-2) in RAW 264.7 cells. MCR extract suppressed the production of NO and PGE2 in RAW 264.7 cells in a dose-dependent manner. None of the five components of the MCR extract had any influence on the production of NO. However, caffeic acid and p-coumaric acid inhibited the production of PGE2 and mRNA expression of COX-2 in RAW 264.7 cells. Our results suggest that MCR extract may offer potential as a therapeutic agent for the treatment of inflammation. The method we have established will help to improve the quality control of MCR extracts.
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Mitu, Liviu, Sweetlin Rajula Rubavathi, Muthupoongodi Subramani, T. Linda, and S. Balakumar. "Azadirachta indica Leaf as a Corrosion Inhibitor for Coper in Nitric Acid." Revista de Chimie 70, no. 2 (March 15, 2019): 581–84. http://dx.doi.org/10.37358/rc.19.2.6960.
Повний текст джерелаАнотація:
The effect of Azadirachta indica leaf (AIL) extract on the corrosion of copper in 1M HNO3 was investigated by weight loss technique. The result showed that the corrosion rate decreased in the presence of plant extract and inhibition efficiency increased with increasing the concentration of extract. The decreased corrosion rate was due to adsorption of plant extract which was discussed on the basis of Langmuir adsorption isotherm.
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Kim, Gyoung-Deuck, Jin Lee, and Joong-Hyuck Auh. "Metabolomic Screening of Anti-Inflammatory Compounds from the Leaves of Actinidia arguta (Hardy Kiwi)." Foods 8, no. 2 (February 1, 2019): 47. http://dx.doi.org/10.3390/foods8020047.
Повний текст джерелаАнотація:
The metabolomic screening of potential anti-inflammatory compounds in the leaves of Actinidia arguta was performed by using LC-MS/MS. Ethanol extracts were prepared, and the anti-inflammatory effects were investigated based on nitric oxide (NO) synthesis and inducible nitric oxide synthase expression in lipopolysaccharide-induced RAW 264.7 macrophages. The 75% ethanol extract showed the highest inhibitory effect on nitric oxide (NO) production, and it was further separated by in vitro bioassay-guided fractionation using preparative LC with reversed-phase column separation. Through multiple steps of fractionation, sub-fraction 1-3 was finally purified, and caffeic acid derivatives, such as caffeoylthreonic acid and danshensu (salvianic acid A), were successfully identified as key anti-inflammatory compounds by LC-MS/MS and metabolomics analyses. This is the first study identifying anti-inflammatory compounds in A. arguta (Actinidia arguta) leaves through bioassay-guided fractionation and metabolomics screening. Results of this study would be useful for the application of A. arguta leaves as a nutraceutical.
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Sarwar, Shammy, Asif Hasan Malik, Muhammad Ashikur Rahman, Md Zakiur Rahman, and Md Sohel Rana. "Antioxidant, cytotoxic and analgesic activities of the methanolic fruit extract of Terminalia chebula Retz." International Current Pharmaceutical Journal 3, no. 1 (December 9, 2013): 219–22. http://dx.doi.org/10.3329/icpj.v3i1.17296.
Повний текст джерелаАнотація:
The present study was aimed to investigate antioxidant, analgesic and cytotoxic activity of the methanolic extract of Terminalia chebula Retz. fruits. Antioxidant potential of the extract was evaluated by using nitric oxide scavenging assay, reducing power and total antioxidant capacity. The extract showed significant activities in all antioxidant assays compared to ascorbic acid in a dose dependent mode. In nitric oxide scavenging assay, the IC50 value of the extract was found to be 51.3 µg/mL while the IC50 value of ascorbic acid was 77.4 µg/mL. In addition to strong reducing power, total antioxidant activity of the extract was also found to increase in a dose dependent manner. The analgesic activity was evaluated using acetic acid-induced writhing test in mice. The extract, at a dose of 500 mg/kg, showed a maximum of 44.17 % inhibition (p < 0.05) of writhing reaction compared to the reference drug diclofenac-sodium (66.96 %). The extract also showed moderate cytotoxic activity in brine shrimp lethality bioassay and the LC50 value was found to be 97.36 µg/mL.DOI: http://dx.doi.org/10.3329/icpj.v3i1.17296 International Current Pharmaceutical Journal, December 2013, 3(1): 219-222
Дисертації з теми "Nitric acid extract"
1
Вецнер, Юлана Ігорівна. "Технологія NPCа-добрив з використанням карбаміду та фосфоритів з низьким вмістом фосфору (V) оксиду". Thesis, НТУ "ХПІ", 2015. http://repository.kpi.kharkov.ua/handle/KhPI-Press/18483.
Повний текст джерелаАнотація:
Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.17.01 – технологія неорганічних речовин. – Національний технічний університет "Харківський політехнічний інститут", Харків, 2015. Дисертацію присвячено розробці наукових основ технології комплексних NPCa-добрив з мікроелементами із залученням фосфоровмісної сировини з низьким вмістом фосфору (V) оксиду. Вперше на основі термодинамічних розрахунків, експериментальних досліджень та рентгенофазових аналізів визначено перелік реакцій, що перебігають в процесі взаємодії карбаміду з нітратно-кислотною витяжкою (НКВ). Визначено технологічні параметри взаємодії карбаміду з НКВ та процесу амонізації NPCа-добрив, а також розроблено принципову схему, яка дозволяє отримати низку комплексних NPCa-добрив з мікроелементами по безвідходній технології із залученням фосфоровмісної сировини України з низьким вмістом фосфору (V) оксиду. Встановлено, що взаємодія карбаміду з НКВ відбувається у кінетичній області та створено кінетичну модель процесу, знайдено константи швидкості, енергію активації. Створена математична модель, яка дозволяє розрахувати технологічні параметри процесу і хімічний реактор синтезу. Отримане комплексне NPCa-добриво з мікроелементами завдяки високому вмісту водорозчинної та засвоюваної форм Р₂О₅ та СаО при агрохімічних випробуваннях у Національному науковому центрі "Інститут ґрунтознавства і агрохімії імені О. Н. Соколовського" показало на підвищення врожайності овочевих культур до 12 ÷ 30 %. Доведено їх економічну доцільність.Dissertation for degree of candidate of technical sciences, specialty 05.17.01 - Technology of inorganic substances. - National Technical University "Kharkov Polytechnic Institute", Kharkov, 2015. Dissertation is devoted to development of scientific bases of technology NPCa - involving phosphorus fertilizer raw materials with low content of phosphorus (V) oxide. For the first time on the basis of thermodynamic calculations and experimental studies, X-ray analysis of a list of reactions in the process of interaction with the urea nitrogen - acid extract (NAE). Defined technological parameters of the interaction of urea with nitrogen - acid extract and ammoniation process NPCa-fertilizers and developed concept that allows you to receive a number of complex NPCa-fertilizer with trace elements of non-waste technology using phosphorus-containing raw materials in Ukraine are low in phosphorus (V) oxide. It was found that the interaction of urea with the nitrogen - acid extract is happening in the kinetic region, established kinetic model of the process, found the rate constants, activation energy. A mathematical model that allows you to calculate the technological parameters of the process and the chemical synthesis reactor. The resulting complex NPCa - fertilizer with trace elements due to the high content of water-soluble and digestible forms of Р₂О₅ and CaO in the agro-chemical tests at the National Scientific Center "Institute for Soil Science and Agricultural Chemistry named after Sokolovsky" has shown an increase in crop yields of up to 12 ÷ 30 %. Prove their economic viability.
2
Вецнер, Юлана Ігорівна. "Технологія NPCа-добрив з використанням карбаміду та фосфоритів з низьким вмістом фосфору (V) оксиду". Thesis, НТУ "ХПІ", 2015. http://repository.kpi.kharkov.ua/handle/KhPI-Press/18482.
Повний текст джерелаАнотація:
Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.17.01 – технологія неорганічних речовин. – Національний технічний університет "Харківський політехнічний інститут", Харків, 2015.
Дисертацію присвячено розробці наукових основ технології комплексних NPCa-добрив з мікроелементами із залученням фосфоровмісної сировини з низьким вмістом фосфору (V) оксиду. Вперше на основі термодинамічних розрахунків, експериментальних досліджень та рентгенофазових аналізів визначено перелік реакцій, що перебігають в процесі взаємодії карбаміду з нітратно-кислотною витяжкою (НКВ). Визначено технологічні параметри взаємодії карбаміду з НКВ та процесу амонізації NPCа-добрив, а також розроблено принципову схему, яка дозволяє отримати низку комплексних NPCa-добрив з мікроелементами по безвідходній технології із залученням фосфоровмісної сировини України з низьким вмістом фосфору (V) оксиду. Встановлено, що взаємодія карбаміду з НКВ відбувається у кінетичній області та створено кінетичну модель процесу, знайдено константи швидкості, енергію активації. Створена математична модель, яка дозволяє розрахувати технологічні параметри процесу і хімічний реактор синтезу. Отримане комплексне NPCa-добриво з мікроелементами завдяки високому вмісту водорозчинної та засвоюваної форм Р₂О₅ та СаО при агрохімічних випробуваннях у Національному науковому центрі "Інститут ґрунтознавства і агрохімії імені О. Н. Соколовського" показало на підвищення врожайності овочевих культур до 12 ÷ 30 %. Доведено їх економічну доцільність.Dissertation for degree of candidate of technical sciences, specialty 05.17.01 - Technology of inorganic substances. - National Technical University "Kharkov Polytechnic Institute", Kharkov, 2015. Dissertation is devoted to development of scientific bases of technology NPCa - involving phosphorus fertilizer raw materials with low content of phosphorus (V) oxide. For the first time on the basis of thermodynamic calculations and experimental studies, X-ray analysis of a list of reactions in the process of interaction with the urea nitrogen - acid extract (NAE). Defined technological parameters of the interaction of urea with nitrogen - acid extract and ammoniation process NPCa-fertilizers and developed concept that allows you to receive a number of complex NPCa-fertilizer with trace elements of non-waste technology using phosphorus-containing raw materials in Ukraine are low in phosphorus (V) oxide. It was found that the interaction of urea with the nitrogen - acid extract is happening in the kinetic region, established kinetic model of the process, found the rate constants, activation energy. A mathematical model that allows you to calculate the technological parameters of the process and the chemical synthesis reactor. The resulting complex NPCa - fertilizer with trace elements due to the high content of water-soluble and digestible forms of Р₂О₅ and CaO in the agro-chemical tests at the National Scientific Center "Institute for Soil Science and Agricultural Chemistry named after Sokolovsky" has shown an increase in crop yields of up to 12 ÷ 30 %. Prove their economic viability.
3
Zaki, Mohamed. "Réactivité et hémisynthèse des constituants majoritaires, de type eudesmanes, contenus dans des extraits de Dittrichia Viscosa." Thesis, Orléans, 2015. http://www.theses.fr/2015ORLE2014/document.
Повний текст джерелаАнотація:
Au cours de ces dernières années, les sesquiterpénoïdes de type eudesmane et leurs activités biologiques font l'objet de nombreuses études phytochimiques et pharmacologiques, ainsi que des recherches de voies de synthèse et d'hémisynthèse. Pour notre part, nous nous sommes intéressés à la synthèse des analogues de types eudesmanes par fonctionnalisation des constituants majoritaires de Dittrichia Viscosa. Dans le premier chapitre, nous avons donné un rappel bibliographique sur l’aspect botanique de Dittrichia Viscosa, ainsi qu’une description phytochimique qui montre que cette plante renferme différents constituants : terpénödes, flavonoïdes, phénylpropanoïdes et polycétides présentant des propriétés pharmacologiques variés. Dans le deuxième chapitre, et après un rappel bibliographique sur les différents types d’eudesmane et l’extraction et la purification des produits majoritaires de Dittrichia Viscosa (l'acide α-costique, l'acide ilicique et la tomentosine), nous avons réalisé l’étude des réarrangements des époxy-eudesmanes par catalyse acide et la synthèse de l'aldéhyde α-costal et ses analogues. Nous avons aussi mise au point des conditions réactionnelles de fonctionnalisation de la double liaison C11-C13 par couplage de Heck permettant l’accès à des librairies d'eudesmanes arylés en position 13. En fin, le dernier chapitre est consacré à l’étude de la réactivité de la tomentosine vis-à-vis des additions nucléophiles (type Addition de Michael) et des additions 1,3 dipolaire (des nitrones et des oxydes de nitrile) sur la double liaison conjuguée exo-cycliqueIn recent years, the sesquiterpenoids eudesmane type and their biological activities are subject to numerous phytochemical and pharmacological studies and research of synthetic and semisynthetic routes. For our part, we are interested in the synthesis of similar types of eudesmanes by functionalization of the major constituents of Dittrichia Viscosa. In the first part we gave a bibliographical recall on the botanical aspect of Dittrichia Viscosa and a phytochemical description shows that this plant contains various constituents: terpénödes, flavonoids, phenylpropanoids and polyketides with various pharmacological properties. In the second part, and after giving a bibliographical recall of the different types of eudesmane and extraction and purification of major products of Dittrichia Viscosa (α-costique acid, ilicique acid and tomentosin), we realized the study of epoxy eudesmanes rearrangements by acid catalysis and the synthesis of α-costal aldehyde and its analogues. We also focus on the reaction conditions for functionalization of C11-C13 dual link Heck coupling allowing access to libraries eudesmanes aryl in position 13. In the last part, we are interested to the study of the reactivity of the tomentosin with nucleophilic additions (type Michael Addition) and 1,3-dipolar additions (nitrones and nitrile oxides) on the double link exo-cyclic combined
Частини книг з теми "Nitric acid extract"
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Taber, Douglass F. "The Magnus Synthesis of ( ± )-Codeine." In Organic Synthesis. Oxford University Press, 2013. http://dx.doi.org/10.1093/oso/9780199965724.003.0088.
Повний текст джерелаАнотація:
Although there have been many synthetic approaches to morphine and its methyl ether codeine 3, the pentacyclic structure of these Papaver alkaloids continues to intrigue organic chemists. Philip Magnus of the University of Texas devised (J. Am. Chem. Soc . 2009, 131, 16045) an elegant route to 3 based on the conversion of 1 to 2 by way of an intramolecular Michael addition. The starting point for the synthesis was the commercial bromoaldehyde 4. Coupling with 5 delivered the substituted biphenyl 6, which was carried on to the mixed bromo acetal 8. On exposure to fluoride ion, 8 was desilylated, and the intermediate phenoxide cyclized with impressive facility to give 1. Exposure of 1 to nitromethane delivered the tetracyclic 2. This reaction apparently was initiated by Henry addition of the nitromethane to the aldehyde. The intramolecular Michael addition of the intermediate Henry adduct then proceeded to give the desired cis diastereomer of the newly formed ring. Finally, loss of water gave 2. Conjugate reduction of the nitroalkene 2 led to 9 with remarkable diastereocontrol. Exposure of 9 to LiAlH4 converted the nitro group to the amine and the enone to the allylic alcohol. On exposure to acid, the hemiacetal was hydrolyzed. The liberated aldehyde underwent reductive amination with the free amine, while at the same time ionic cyclization closed the ether ring. N-acylation completed the conversion to 10. The ether 10 had previously been converted to codeine and then, in a single demethylation step, to morphine. In that synthesis, the alkene of 10 was directly epoxidized. The resulting “up” epoxide reacted only sluggishly with phenylselenide anion, and the relative configuration of the resulting allylic alcohol had to be inverted by oxidation followed by reduction. In the current synthesis, exposure of the alkene 10 to dibromohydantoin under aqueous conditions to form the bromohydrin effected concomitant arene bromination, to give, after base treatment, the “down” epoxide 12. Phenylselenide opening of the epoxide was then facile, and the product allylic alcohol had the correct relative configuration for codeine and morphine. The extra Br was of no consequence, as it was removed by the final LiAlH4 reduction.
Тези доповідей конференцій з теми "Nitric acid extract"
1
Hsiao, Hsien-Ming, Chang-Liang Hu, Kuang-Li Chien, Wen-Chen Lee, and Tsong-Yang Wei. "Experiment on the Treatment of Waste Extraction Solvent From the Molybdenum-99 Process." In ASME 2013 15th International Conference on Environmental Remediation and Radioactive Waste Management. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/icem2013-96218.
Повний текст джерелаАнотація:
In the Mo-99 (Molybdenum-99) isotope extraction test process for radiopharmaceutical applications, organic solvent is used to extract Mo-99 from an irradiated UO2 dissolution. The extraction solvent was stored when the test work was stopped. A total of about 120 liters of waste solvent was stored at INER (Institute of Nuclear Energy Research, Taiwan). The extraction solvent consisted of 5% di-(2-ethylhexyl)-phosphoric acid (D2EHPA) and kerosene. The radionuclides found in the waste solvent include Cs-137, Am-241, Tc-99, and Sr-90, which give off gross alpha and beta radioactivity of 1898 and 471 Bq/ml, respectively. This study aims to remove radionuclides from the waste solvent using sodium carbonate and sodium hydroxide solutions in different concentrations. After mixing the waste solvent with the alkaline solution followed by settling, a third phase other than organic and aqueous phase appeared which is expected due to the saponification reaction. The experimental results showed that increasing the number of washing and the alkaline solution concentration could enhance the radionuclides removal rate. An optimal removal method was proposed using 2M Na2CO3 solution twice followed by 1M NaOH solution one time for the third phase generated early in the mixing stages. The remaining gross alpha and beta radioactivity of the treated organic solvent was 2 and 3 Bq/ml, respectively. The treated solvent could be stabilized by ashing at 500°C and then immobilized. The alkaline solution would be neutralized by hydrochloric or nitric acid and then treated using a variety of adsorbents or bone char via adsorption to remove nuclides to meet the wastewater discharge limitation.
2
Tsaoulidis, Dimitrios, Natalia Plechkova, Kenneth R. Seddon, and Panagiota Angeli. "{UO2}2+ Extraction Using Ionic Liquids in Intensified Extractors." In 2014 22nd International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/icone22-31268.
Повний текст джерелаАнотація:
The extraction of dioxouranium(VI) from aqueous nitric acid solutions (3M) into TBP/ionic liquid mixtures (30% v/v), relevant to spent fuel reprocessing, was investigated experimentally in intensified small channel extraction units. The intensified extractor consisted of a “T” shaped inlet and a FEP channel of 0.5 mm internal diameter. Important hydrodynamic characteristics such as, plug length, and plug speed were determined by means of bright field imaging, and were related to the extraction performance of the extraction unit. The amount of dioxouranium(VI) extracted was measured online by using UV-Vis spectroscopy.
3
Ioka, Ikuo, Chiaki Kato, Kiyoshi Kiuchi, and Junpei Nakayama. "Susceptibility of Intergranular Corrosion for Extra High Purity Austenitic Stainless Steel in Nitric Acid." In 16th International Conference on Nuclear Engineering. ASMEDC, 2008. http://dx.doi.org/10.1115/icone16-48776.
Повний текст джерелаАнотація:
Austenitic stainless steels suffer intergranular attack in boiling nitric acid with oxidants. The intergranular corrosion is mainly caused by the segregation of impurities to grain. An extra high purity austenitic stainless steel (EHP alloys) was developed with conducting the new multiple refined melting technique in order to suppress the total harmful impurities less than 100ppm. The basically corrosion behavior of type 310 EHP alloy with respect to nitric acid solution with highly oxidizing ions was investigated. The straining, aging and recrystallizing (SAR) treated type 310 EHP alloy showed superior corrosion resistance for intergranular attack. The segregated boron along the grain boundaries was one of main factor of intergranular corrosion from fission track etching results. The SAR treatment was effective to restrain the intergranular attack for type 310 EHP alloy with B less than 7ppm.
4
Paviet-Hartmann, Patricia, Ana Nunez Gomez-Aleixandre, Joshua Pak, Amparo Glez Espartero, Frederic Poineau, Amber Wright, Edward Mausolf, and Kenneth R. Czerwinski. "Extraction of Technetium as [Tc(II)(NO)(AHA)2H2O]+ Species in the UREX Process." In 17th International Conference on Nuclear Engineering. ASMEDC, 2009. http://dx.doi.org/10.1115/icone17-75509.
Повний текст джерелаАнотація:
As it is envisioned today, the first segment of the UREX+ process uses low nitric acid concentrations for U(VI) extraction where pertechnetate anion, TcO4−, can be co-extracted with the uranyl and nitrate into TBP-hydrocarbon solutions. A reductant complexant, acetohydroxamic acid (AHA) is added to the process through the scrub to limit the extractability of plutonium and neptunium. Recent work performed in our laboratory (Ref. 1) demonstrated that TcO4− undergoes reductive nitrosylation by AHA under a variety of conditions. The resulting divalent technetium is complexed by AHA to form the pseudo-octahedral trans-aquonitrosyl-(diacetohydroxamic)-technetium(II) complex ([Tc(II)(NO)(AHA)2H2O]+). In this paper, we are reporting the extraction of [Tc(II)(NO)(AHA)2H2O]+ complex by new designed macrocompounds as well as commercially available crown ethers from 18-crown-6 to 24-crown-8 in ring size and of varying derivatization. Several organic diluents with different dielectric constants are used to enhance the distribution coefficient of technetium (II). The experimental efforts are focused on determining the best extraction conditions by varying the macrocomponds nature and concentration, and the organic phase composition.
5
Ioka, Ikuo, Jun Suzuki, Takafumi Motoka, Kiyoshi Kiuchi, and Junpei Nakayama. "Influence of Impurities on Intergranular Corrosion of Extra High Purity Austenitic Stainless Steels." In 17th International Conference on Nuclear Engineering. ASMEDC, 2009. http://dx.doi.org/10.1115/icone17-75531.
Повний текст джерелаАнотація:
An intergranular corrosion is observed in austenitic stainless steels exposed to high temperature, concentrated nitric acid (HNO3) solution with highly oxidizing ions. It is an important degradation mechanism of austenitic stainless steels for use in a nuclear fuel reprocessing plant. The intergranular corrosion is caused by the segregation of impurities to grain boundaries and the resultant formation of active sites. Extra High Purity (EHP™) austenitic stainless steel was developed with conducting the new multiple refined melting in order to suppress the total harmful impurities less than 100ppm. The intergranular corrosion behavior of EHP alloys with various impurities was examined in boiling HNO3 solution with highly oxidizing ions to find a correlation between the intergranular corrosion and the impurities of EHP alloys. A good correlation was confirmed between the degree of intergranular corrosion and the corrosion rate. The relationships between the corrosion rate and the impurities content of EHP alloys was determined using a multiple regression analysis. The influence on corrosion rate became small in order of B, P, Si, C, S and Mn. It was important to control B in intergranular corrosion behavior of EHP alloys.
6
Aerts, Wouter, Thomas De Bruecker, and Anna Lytek. "Possibilities of Soil Washing for Decontamination at Belgoprocess." In ASME 2013 15th International Conference on Environmental Remediation and Radioactive Waste Management. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/icem2013-96221.
Повний текст джерелаАнотація:
Contaminated soils form a large part of the nuclear waste arising from decommissioning activities. The storage and disposal of these large volumes of waste is costly. For this reason techniques which can decontaminate this waste stream to free release levels are economically very interesting. A feasibility study of the possibilities of soil washing to decontaminate such soils was ordered by NIRAS/ONDRAF and performed at Belgoprocess in collaboration with DEC. Initial contamination level and particle size distributions of contaminated soils from three different sources were determined. The main isotopes detected with gamma spectrometry contained in the waste were 241Am, 137Cs, 226Ra, 60Co and 232Th. The particle size distribution revealed that more than half of the mass of the quartz sand that makes up the soil has a particle size between 125 and 212μm. This fraction is less contaminated than the fractions containing smaller particles. However, separation of the fines fraction (< 125 μm) was not enough to achieve the free release limit. Soil attrition was tested as an extra decontamination step for the sand fraction. The removal efficiencies for the different radionuclides contained in the soil were measured. The process conditions were optimized to achieve maximum removal and a treatment method for the secondary waste coming from this process step was determined. The soil washing process was not only performed with water but also with nitric acid to assess the possibilities of a combination of a mechanical and a chemical decontamination process. Reduction efficiencies of 60–80% for the most relevant radionuclides were recorded.