Готові списки джерел за темами / Oxidized system

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Добірка наукової літератури з теми "Oxidized system"

Автор: Grafiati
Опубліковано: 30 травня 2022
Оновлено: 31 травня 2022

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Статті в журналах з теми "Oxidized system"

1

Hu, Yan Fang, Xiao Dong Zhang, Zhao Guang Nie, Ya Cheng Xing, Bo Qun Lin, and Li Li Song. "Selective Oxidation of Corn Starch in TEMPO-Mediated System." Advanced Materials Research 1051 (October 2014): 221–24. http://dx.doi.org/10.4028/www.scientific.net/amr.1051.221.

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Анотація:
With TEMPO-NaClO-NaBr as the selective oxidation system, the oxidized corn starch was prepared from the corn starch, substituting traditional pre-gelatinized corn starch. The relationship of the carboxyl mass fraction of the oxidized starch and the dosage of oxidant was studied under the conditions such as: the mass of the corn starch was 5.0g, the pH was 10.00, the reaction temperature was 20 °C. The structure of the oxidized corn starch was characterized by IR. The results showed that when the consumption of NaClO was 67.5 mL, the reaction time was 2.5 h, the carboxyl of oxidized starch can reach 10.60%.
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2

Khodaei, Mohammad Mehdi, Kiumars Bahrami, and Mohammad Khedri. "The efficient and chemoselective MoO3-catalyzed oxidation of sulfides to sulfoxides and sulfones with H2O2." Canadian Journal of Chemistry 85, no. 1 (January 1, 2007): 7–11. http://dx.doi.org/10.1139/v06-177.

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Анотація:
Hydrogen peroxide together with MoO3 as catalyst can efficiently and chemoselectivity oxidize sulfides to sulfoxides and sulfones in the presence of other oxidized functional groups in ethanol at 50 °C in short reaction times.Key words: oxidation, sulfides, sulfoxides, sulfones, H2O2–MoO3 system.
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3

Uetrecht, Jack P. "Myeloperoxidase as a generator of drug free radicals." Biochemical Society Symposia 61 (November 1, 1995): 163–70. http://dx.doi.org/10.1042/bss0610163.

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Reactive metabolites are believed to be responsible for many types of toxicity, including idiosyncratic drug reactions. Bone marrow is a frequent target of idiosyncratic reactions, and, since these reactions have characteristics that suggest involvement of the immune system, the formation of reactive metabolites by leucocytes could also play a role in the aetiology of idiosyncratic drug reactions. The major oxidation system in neutrophils and monocytes is a combination of NADPH oxidase and myeloperoxidase. This system oxidizes primary arylamines, such as sulphonamides, to reactive metabolites and these drugs are also associated with a high incidence of agranulocytosis, generalized idiosyncratic reactions and/ or drug-induced lupus. Clozapine is oxidized by this system to a relatively stable nitrenium ion; clozapine is also associated with a high incidence of agranulocytosis. Arylamines that have an oxygen or nitrogen in the para position, such as amodiaquine, vesnarinone and 5-aminosalicylic acid, are oxidized to quinone-like reactive intermediates. Aminopyrine is oxidized to a very reactive dication. Such reactive metabolites could also inhibit neutrophil function and mediate some of the therapeutic effects of these drugs: for example, the use of dapsone for dermatitis herpetiformis and the use of 5-aminosalicylic acid for inflammatory bowel disease.
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4

Grisham, M. B., and E. M. Ryan. "Cytotoxic properties of salivary oxidants." American Journal of Physiology-Cell Physiology 258, no. 1 (January 1, 1990): C115—C121. http://dx.doi.org/10.1152/ajpcell.1990.258.1.c115.

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Salivary peroxidase and to a lesser extent myeloperoxidase are present in significant concentrations in saliva and catalyze the oxidation of thiocyanate anion (SCN-) by H2O2 to yield the potent oxidants hypothiocyanous acid (HOSCN) and its conjugate base hypothiocyanite anion (OSCN-). The objective of this study was to characterize the cytotoxic potential of peroxidase-generated HOSCN/OSCN- toward human erythrocytes. We found that HOSCN/OSCN- (0.25 mM) generated by the peroxidase-H2O2-SCN- system caused significant hemolysis at pH 6.0 but not at pH 6.5, 7.0, or 7.4. Erythrocyte hemoglobin (OxyHb) was oxidized to methemoglobin (MetHb) at all pH values tested; however, the rate of MetHb formation was dramatically increased at low pH and was not affected by inosine hexaphosphate, suggesting that hemoglobin was oxidized primarily by HOSCN. Concurrent with oxidation of hemoglobin (Hb), there was a pH-dependent consumption of HOSCN/OSCN- with more of the oxidant consumed at pH 6.0 compared with pH 6.5, 7.0, or 7.4. The enhanced oxidation of Hb at acidic pH was not due simply to increased membrane permeability by the uncharged species (HOSCN), since both erythrocyte lysate Hb and purified Hb were oxidized to the same extent at low pH as were intact erythrocytes. It is concluded that both OSCN- and HOSCN enter human erythrocytes where the protonated oxidant (HOSCN) mediates hemolysis and oxidizes OxyHb to MetHb, whereas both HOSCN and OSCN- oxidize glutathione (GSH). These data suggest that the extracellular pH may play an important role in modulating the cytotoxic properties of salivary oxidants.
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5

Mattson, Bengt, Bengt Stenberg, Sture Persson, and Erik Östman. "Thermo-Oxidative Degradation of Thick-Walled Rubber Materials Studied by IR-Technique and Computed X-Ray Tomography Scanning." Rubber Chemistry and Technology 63, no. 1 (March 1, 1990): 23–31. http://dx.doi.org/10.5254/1.3538239.

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Abstract Natural rubber cylinders vulcanized with two different systems, TMTD, which is an efficient vulcanizing system (EV system) and S/CBS, which is a conventional system, have been studied with respect to thermo-oxidative aging gradients, by the ATR-IR-technique (attenuated total-reflection infrared spectroscopy), computed x-ray tomography scanning and swelling. Observed aging processes are dominated by the formation of an oxidized layer whose low permeability to oxygen protects the interior of the material from oxidative aging processes as long as it is intact. The time to the formation of the oxidized layer is the major reason for the differences in the aging gradients. The oxidized layer is formed rapidly in the conventional system, whereas the formation is inhibited by dithiocarbamates in the EV system. Oxygen therefore diffuses into the EV materials, giving deeper oxidative aging than in the conventional materials at the same temperature. The conclusion drawn from the results of this study is that an earlier formation of an oxidized layer is advantageous with respect to thermo-oxidative aging of the bulk. Although it must be stated that, due to the better thermal stability of an EV system and to the poor mechanical properties of an oxidized layer, no objection is here raised to the accepted view that an EV system has superior aging properties.
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6

Liu, G. D., Z. X. Zhao, G. C. Che, J. W. Li, and F. Wu. "Superconducting properties of the oxidized La2−xBaxCuO4 system." Physica C: Superconductivity 282-287 (August 1997): 755–56. http://dx.doi.org/10.1016/s0921-4534(97)00392-4.

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7

Aksu, Seda, Isabel W. C. E. Arends, and Frank Hollmann. "A New Regeneration System for Oxidized Nicotinamide Cofactors." Advanced Synthesis & Catalysis 351, no. 9 (June 2009): 1211–16. http://dx.doi.org/10.1002/adsc.200900033.

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8

Canales, Camila, Leyla Gidi, Roxana Arce, Francisco Armijo, María Aguirre, and Galo Ramírez. "Electro-Reduction of Molecular Oxygen Mediated by a Cobalt(II)octaethylporphyrin System onto Oxidized Glassy Carbon/Oxidized Graphene Substrate." Catalysts 8, no. 12 (December 6, 2018): 629. http://dx.doi.org/10.3390/catal8120629.

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Анотація:
The oxygen reduction reaction (ORR) is the most important reaction in life processes and in energy transformation. The following work presents the design of a new electrode which is composed by deposited cobalt octaethylporphyrin onto glassy carbon and graphene, where both carbonaceous materials have been electrochemically oxidized prior to the porphyrin deposition. The novel generated system is stable and has an electrocatalytic effect towards the oxygen reduction reaction, as a result of the significant overpotential shift in comparison to the unmodified electrode and to the electrodes used as target. Kinetic studies corroborate that the system is capable of reducing molecular oxygen via four electrons, with a Tafel slope value of 60 mV per decade. The systems were morphologically characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM) Electrochemical impedance spectroscopy studies showed that the electrode previously oxidized and modified with cobalt porphyrin is the system that possesses lower resistance to charge transfer and higher capacitance.
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9

Mander, Gerd J., Huaming Wang, Elizabeth Bodie, Jens Wagner, Kay Vienken, Claudia Vinuesa, Caroline Foster, et al. "Use of Laccase as a Novel, Versatile Reporter System in Filamentous Fungi." Applied and Environmental Microbiology 72, no. 7 (July 2006): 5020–26. http://dx.doi.org/10.1128/aem.00060-06.

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ABSTRACT Laccases are copper-containing enzymes which oxidize phenolic substrates and transfer the electrons to oxygen. Many filamentous fungi contain several laccase-encoding genes, but their biological roles are mostly not well understood. The main interest in laccases in biotechnology is their potential to be used to detoxify phenolic substances. We report here on a novel application of laccases as a reporter system in fungi. We purified a laccase enzyme from the ligno-cellulolytic ascomycete Stachybotrys chartarum. It oxidized the artificial substrate 2,2′-azino-di-(3-ethylbenzthiazolinsulfonate) (ABTS). The corresponding gene was isolated and expressed in Aspergillus nidulans, Aspergillus niger, and Trichoderma reesei. Heterologously expressed laccase activity was monitored in colorimetric enzyme assays and on agar plates with ABTS as a substrate. The use of laccase as a reporter was shown in a genetic screen for the isolation of improved T. reesei cellulase production strains. In addition to the laccase from S. charatarum, we tested the application of three laccases from A. nidulans (LccB, LccC, and LccD) as reporters. Whereas LccC oxidized ABTS (Km = 0.3 mM), LccD did not react with ABTS but with DMA/ADBP (3,5-dimethylaniline/4-amino-2,6-dibromophenol). LccB reacted with DMA/ADBP and showed weak activity with ABTS. The different catalytic properties of LccC and LccD allow simultaneous use of these two laccases as reporters in one fungal strain.
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10

Kooti, Mohammad, and Mehdi Jorfi. "Mild and Efficient Oxidation of Aromatic Alcohols and Other Substrates Using NiO2/CH3COOH System." E-Journal of Chemistry 5, no. 2 (2008): 365–69. http://dx.doi.org/10.1155/2008/826184.

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Анотація:
A variety of aromatic alcohols were efficiently oxidized to their corresponding aldehydes and ketones in good to excellent yields using nickel peroxide activated by acetic acid. Some thiols and amines were also readily oxidized by this oxidant under mild conditions.
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Більше джерел

Дисертації з теми "Oxidized system"

1

Wang, Yanmei. "THE THIOL REDOX SYSTEM IN OXLDL-INDUCED MACROPHAGE INJURY." UKnowledge, 2006. http://uknowledge.uky.edu/gradschool_theses/383.

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Анотація:
Macrophage death is likely to contribute to the transformation of fatty streaks into advanced atherosclerotic lesions. Previous work in the laboratory showed that OxLDL promotes cell death in human macrophages by a mechanism involving intracellular peroxide formation. Here we show that glutathione depletion induced by OxLDL occurs independent of peroxyl radical formation. Our data suggest that the depletion of glutathione is the fundamental defect that renders macrophages susceptible to OxLDL-induced cell injury, but alone is not sufficient to kill macrophages. We indicate that increased protein-Sglutathionylation is involved in OxLDL-induced macrophage death. A potentiation of OxLDL toxicity was observed in macrophages transfected with siRNA directed against either glutathione reductase or glutaredoxin. Our data suggests that OxLDL-induced cell injury in human macrophage is mediated by the depletion of GSH, a decreased in the GSH/GSSG ratio and peroxyl radical formation. All three signals are required for OxLDL-induced macrophage death. Our results also show that the glutathione reductase/glutaredoxin system protects macrophages from OxLDL-induced cell death.
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2

Muraco, Cory E. "Isolation and Characterization of Oxidized Lysozyme Variants Produced by a Copper(II)/Hydrogen Peroxide Metal-Catalyzed Oxidation System." Youngstown State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1369228839.

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3

Lidman, Martin. "The role of the mitochondrial membrane system in apoptosis : the influence of oxidative stress on membranes and their interactions with apoptosis-regulating Bcl-2 proteins." Doctoral thesis, Umeå universitet, Kemiska institutionen, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-110701.

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Анотація:
Apoptosis is a crucial process in multicellular organisms in sculpting them, especially during embryogenesis. In addition, apoptosis is responsible for the clearance of harmful or damaged cells which can otherwise be detrimental to the organism. The Bcl-2 family proteins are key players in the regulation of the intrinsic pathway of the apoptotic machinery. This family consists of three subfamilies with B-cell CLL/lymphoma 2 (Bcl-2) protein itself representing anti-apoptotic members, the Bcl-2-associated X protein (Bax), and pro-apoptotic BH3-only signaling proteins. The interplay between pro- and anti-apoptotic proteins on the mitochondrial membranes is central to the balance between the life and death decision of whether the membrane should be permeabilized or not. The cytosolic Bax protein can upon cellular stress translocate to the mitochondrial membrane where it can either carry out its action of forming homo-oligomers that cause outer membrane permeabilization or be inhibited there by the anti-apoptotic membrane protein Bcl-2. Upon mitochondrial outer membrane permeabilization (MOMP) apoptogenic factors leak out from the intermembrane space (IMS) of the mitochondria, leading to caspase activation and ultimately cell death. A common stress signal initiating apoptosis is an increased formation of reactive oxygen species (ROS in the mitochondria, who can cause oxidative damage to lipid membranes. This membrane damage presumably influences the lipid landscape and the membrane features and hence the interactions of the Bcl-2 family proteins with each other and the mitochondrial outer membrane (MOM). To investigate the significance of membrane oxidation on the behavior of the Bcl-2 family proteins, especially Bax, synthetically produced oxidized phospholipids (OxPls) were incorporated in MOM-mimicking vesicles. Differential scanning calorimetry (DSC), nuclear magnetic resonance (NMR) spectroscopy and circular dichroism (CD) spectroscopy revealed a major perturbation in membrane organization in the presence of OxPls. These changes in membrane properties increase the affinity of Bax to its target membrane and enable its partial penetration and formation of pores, as fluorescence leakage assays confirmed. However, in the absence of BH3-only proteins these pores are not sufficiently large for the release of apopototic factors such as cytochrome C (CytC). To understand the inhibition of Bax by the full-length Bcl-2 protein, suitable detergent solubilizing conditions were carefully chosen to enable the measurement of their direct binding to each other outside the membrane, by an antimycin A2 fluorescence assay. The observed protein-protein interaction was confirmed by surface plasmon resonance (SPR). An established protocol for the reconstitution of Bcl-2 into stable proteoliposomes now paves the way for structural studies of this key protein, in its membrane environment near physiological conditions; information essential for understanding its function, on a molecular level, and its potential as a cancer drug target.
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4

Kerns, Michael Lester. "I. A Model System for the Anodic Oxidation of 4-(2'- Alkenylphenyl)Phenols: Evidence for a Phenoxonium Ion Intermediate II. Carbon-Carbon Bond Forming Reactions of Oxidized Phenol Intermediates with Vinyl Sulfides III. Naphthopyran Quinone.. /." The Ohio State University, 1995. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487930304684744.

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5

Пітак, Ярослав Миколайович. "Вогнетривкі та жаростійкі неформовані матеріали на основі композицій системи RO – R₂O₃ – RO₂ – P₂O₅". Thesis, Національний технічний університет "Харківський політехнічний інститут", 2005. http://repository.kpi.kharkov.ua/handle/KhPI-Press/40380.

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Анотація:
Дисертація на здобуття наукового ступеня доктора технічних наук за спеціальністю 05.17.11 – технологія тугоплавких неметалічних матеріалів. – Національний технічний університет “Харківський політехнічний інститут”, Харків, 2005. Дисертація присвячена розробці наукової концепції створення вогнетривких та жаростійких неформованих матеріалів на основі композицій системи RO – R₂O₃ – RO₂ – P₂O₅. Досліджено субсолідусну будову чотирикомпонентних систем: M–A–S–P, C–А–S–P, Zn–Z–S–B, Zn–A–Z–S, C–M–S–P, A–Z–S–P, M–Z–S–P, C–A–S–B, C–A–Z–S, C–M–A–S, C–Sr–A–Z. Визначено співіснуючі фази в системах, виконано триангуляцію потрійних підсистем та тетраедрацію чотирикомпонентних систем, визначено їх об’єми та ступінь асиметрії, побудовано топологіч-ний граф взаємозв’язку елементарних тетраедрів, надано геометро-топологічну характеристику фаз систем, проведено оцінку евтектичних температур в перерізах систем та побудовано поверхні ліквідусу перетинів. На підставі фізико-хімічних досліджень систем розроблено принципи одержання нових вогнетривких та жаростійких неформованих матеріалів. Розроблені нові склади вогнетривких теплоізоляційних матеріалів, жаростійких та вогнетривких цементів та бетонів на їх основі, набивних мас з високими фізико-механічними та технічними властивостями. Встановлено закономірності фазоутворення, та розроблено принципи одержання цих матеріалів.
Thesis for Doctor of Technical Sciences degree on the speciality 05.17.11 – technology of refractory not metal materials. – National Technical University “Kharkiv Polytechnic Institute”, Kharkiv, 2005. The thesis is devoted to develop scientific conception of creation of fire-resistant and heat resisting materials on the basis of the system RO – R₂O₃ – RO₂ – P₂O₅ compositions. The sub-solidus structure of the four component systems has been investigated: M–A–S–P, C–А–S–P, Zn–Z–S–B, Zn–A–Z–S, C–M–S–P, A–Z–S–P, M–Z–S–P, C–A–S–B, C–A–Z–S, C–M–A–S, C–Sr–A–Z. The co-existed phases in the systems have been determined, the tetrahedra for quaternary systems have been carried out, the volumes elementary tetrahedrons have been determined, the topological characteristic of phases of systems have been given. On the basis of physic-chemical researches of the systems the principles of reception new fire-resistant and heat resisting unforming materials have been developed. New compositions of materials on the base of refractories and cements with high physical, mechanical and technical properties have been developed. The principles of phase-formation have been set up and the principles of obtaining these materials have been worked out.
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6

Daher, Jalil. "Exposure of endothelial cells to physiological levels of myeloperoxidase modified LDL delays pericellular fibrinolysis and reduces cell motility." Doctoral thesis, Universite Libre de Bruxelles, 2014. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209337.

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Анотація:
Cardiovascular diseases are considered the first cause of death in westernized societies. They are directly linked to atherosclerosis, a clinical condition characterized by a thickening of the arterial wall. Atherosclerosis is in his turn linked to various genetic and environmental factors; among those factors are high oxidized LDL levels and endothelial dysfunction. In the present study, we have analyzed in vitro the effect of myeloperoxidase oxidized LDL on endothelial cells at the level of fibrinolysis and cell motility.

In the first part of the work, we measured fibrinolysis in real time at the surface of endothelial cells. Our results suggest that myeloperoxidase oxidized LDL interferes with the regulation of fibrinolysis by endothelial cells by decreasing their pro-fibrinolytic activity. This effect was not related to a modification in expression of major regulators of fibrinolysis such as PAI-1 and t-PA. Our data link the current favorite hypothesis that oxidized LDL has a causal role in atheroma plaque formation with an old suggestion that fibrin may also play a causal role. A model that best explains our results would be as follows: oxidized LDL increases fibrin deposition on endothelial cells which will increase their permeability resulting in more oxidized LDL infiltration into the subendothelial space of the arterial wall initiating atherogenesis.

In the second part of the work, we investigated the effect of myeloperoxidase oxidized LDL at the level of endothelial cell motility. We have shown that oxidized LDL is able to decrease cell migration, wound healing and tubulogenesis in endothelial cells. Those effects were not associated with any alteration at the level of neither cell viability nor proliferation. Subsequent gene expression analyses enabled us to link the oxidized LDL induced phenotypical changes in the cells to a change in expression of both microRNA-22 and Heme Oxygenase 1 genes. Our observations suggest a novel role of oxidized LDL not only as an important factor in the initiation of atheromatous lesions, but also as a potential player in the progression of the atherosclerosis disease by impeding blood vessel repair and wound healing at the sites of lesions.


Doctorat en Sciences
info:eu-repo/semantics/nonPublished

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7

Chen, Yumin. "Oxidation of Polymeric Polyphenols (Tannins) in Biologically Relevent Systems." Miami University / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=miami1089232925.

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8

Stoddard, Rob L. "Experimental Investigation of N2O/O2 Mixtures as Volumetrically Efficient Oxidizers for Small Spacecraft Hybrid Propulsion Systems." DigitalCommons@USU, 2019. https://digitalcommons.usu.edu/etd/7690.

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Анотація:
A hybrid thruster system utilizes propellants in two different stages, traditionally a solid fuel and a gaseous or liquid oxidizer. Recently hybrid thrusters have become a popular topic of research due to the high demand of a ”green” replacement for hydrazine. Not only are hybrid thruster systems typically much safer than hydrazine, but they are also a low-cost system with a high reliability in performance. The Propulsion Research Laboratory (PRL) at Utah State University (USU) has developed a hybrid thruster system using 3-D printed acrylonitrile butadiene styrene (ABS) as the fuel and gaseous oxygen (GOX) as the oxidizer. This system has been spaceflight flown and tested in a hard vacuum environment with success. However, GOX has a low density and must be stored at high pressures to be considered viable. This thesis investigates the use of N2O/O2 mixtures, ”Nytrox”, and more commonly known as ”laughing gas”, as a higher density replacement oxidizer for GOX. Ina manner directly analogous to the creation of soda-water using dissolved carbon dioxide, Nytrox is created by bubbling gaseous oxygen under high pressure into nitrous oxide until the solution reaches saturation level. Oxygen in the mixture ullage dilutes the nitrous oxide vapor, and increases the required decomposition activation energy of the fluid by several orders of magnitude. Data from tests using each oxidizer are analyzed and presented for performance comparisons. Comparisons include, ignition reliability, ignition energy, thrust coefficient, characteristic velocity, specific impulse, and regression rate. Nytrox is shown to work effectively as a “drop in” replacement for gaseous oxygen, exhibiting slightly reduced specific impulse and regression rate, but with the trade of a significantly higher volumetric efficiency.
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9

Delles, Rebecca. "DIETARY ANTIOXIDANT SUPPLEMENTATION (ECONOMASE–BIOPLEX) TO ALLEVIATE ADVERSE IMPACTS OF OXIDIZED OIL ON BROILER MEAT QUALITY: A CHEMICAL, TEXTURAL, ENZYMATIC, AND PROTEOMIC STUDY." UKnowledge, 2013. http://uknowledge.uky.edu/animalsci_etds/29.

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This study investigated the influence of dietary antioxidants and quality of oil on the oxidative and enzymatic properties of chicken broiler meat stored in an oxygen-enriched package (HiOx: 80% O2/20% CO2) in comparison with air-permeable polyvinylchloride (PVC) or skin (SK) packaging systems during retail display 2–4 °C for up to 14, 7, and 21 d, respectively. Broilers were fed a diet either with a low-oxidized oil (peroxide vale POV 23 meq O2/kg) or with a high-oxidized oil (POV 121 meq O2/kg), supplemented with an antioxidant pack (200 ppm EconomasE and organic minerals Se, Zn, Cu, Mn, and Fe as in Bioplex) in substitution for vitamin E and inorganic minerals for 42 d. In all packaging systems, lipid oxidation and protein oxidation were inhibited by up to 65% with an antioxidant-supplemented diet when compared to diets without antioxidant supplements. Antioxidant enzyme activities were significantly higher (P < 0.05) in the antioxidant-supplemented diets compared with control diets, regardless of oil quality. Meat samples from the antioxidant-supplemented group, irrespective of oil quality, has less purge and cooking loss compared to control diets. In all packaging systems, meat shear force was higher (P < 0.05) for broilers fed high-oxidized diets than the low-oxidized groups. Comparison between muscle types (breast as white vs. thigh as red) showed a similar trend in muscle susceptibility to oxidized oil in the diet but greater protection of antioxidant supplements for thigh meat in both physiochemical and textural properties. Dietary regimen influenced protein expression in broiler breast meat. Three protein spots from 2-dimensional gel electrophoresis, identified by mass spectrometry as glyceraldehyde 3-phosphate dehydrogenase, creatine kinase, and heat shock protein beta-1 were over-abundant in muscle from low-oxidized diets. The differential proteomes that suggested down regulation of the genes encoding antioxidative proteins upon feeding oxidized oil may be implicated in the broiler meat quality deterioration during storage. In summary, feeding diets with poor oil quality increased the vulnerability of lipids and proteins to oxidation in broiler breast and thigh meat during refrigerated and / or frozen storage in various packaging conditions, yet these effects were alleviated upon dietary supplementation with antioxidants.
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Слюзар, Андрій Володимирович. "Теоретичні основи і технології очищення безкисневих газів від сірководню хінгідронним методом". Diss., Національний університет "Львівська політехніка", 2021. https://ena.lpnu.ua/handle/ntb/56693.

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У дисертації наведено результати досліджень, спрямованих на розвиток теоретичних основ і технологій очищення безкисневих (природних і технологічних) газів від H2S хінгідронними окисними системами (ХОС) з одержанням сірки. Досліджено взаємну розчинність інгредієнтів хінгідронного поглинального розчину (ХПР) та їх вплив на фізико-хімічні властивості розчину. Теоретично обґрунтовано вибір масообмінної апаратури для процесів хемосорбції H2S на стадії очищення газів та О2 на стадії регенерації поглинального розчину. Досліджено вплив умов формування ХОС на її окисно-відновні та фізико-хімічні властивості, що дало змогу вдосконалити технологію приготування поглинального розчину для очищення безкисневих газів від H2S. Вивчено фазову рівновагу в системі H2S - хінгідронний поглинальний розчин. Досліджено вплив різних факторів на хемосорбцію H2S з безкисневих газів і О2 з повітря ХПР у диспергуючих і барботажних абсорберах. Встановлено вплив вуглеводневих компонентів, які містяться у природних і технологічних газах, на хемосорбцію H2S та регенерацію ХПР. Досліджено процеси електрохімічної регенерації ХПР. Розроблено варіанти технологічних схем для очищення природних і технологічних газів від H2S з одержанням дрібнодисперсної сірки і можливістю комбінування цих технологій з технологією полімерної сірки, що підвищує економічну ефективність хінгідронного процесу знесірчення газів. В диссертации представлены результаты исследований, направленных на развитие теоретических основ и технологий очистки бескислородных (природных и технологических) газов от H2S хингидронными окислительными системами (ХОС) с получением серы. Исследованы взаимная растворимость ингредиентов хингидронного поглотительного раствора (ХПР) и их влияние физико-химические свойства раствора. Теоретически обоснован выбор массообменной аппаратуры для процессов хемосорбции H2S на стадии очистки газов и О2 на стадии регенерации поглотительного раствора. Исследовано влияние условий формирования ХОС на их окислительно-восстановительные и физико-химические свойства, что позволило усовершенствовать технологию приготовления ХПР для очистки бескислородных газов от H2S. Изучено фазовое равновесие в системе H2S – ХПР. Исследовано влияние различных факторов на хемосорбцию H2S из бескислородных газов и О2 из воздуха ХПР в диспергирующих и барботажных абсорберах. Установлено влияние углеводородных компонентов, содержащихся в природных и технологических газах, на хемосорбцию H2S и регенерацию ХПР. Исследованы процессы электрохимической регенерации ХПР. Разработаны варианты технологических схем для очистки природных и технологических газов от H2S с получением тонкодисперсной серы и возможностью комбинирования этих технологий с технологией полимерной серы, что повышает экономическую эффективность хингидронного процесса очистки газов. The dissertation presents the results of research aimed at the development of theoretical foundations and technologies for the purification of oxygen-free (natural and technological) gases from H2S by quinhydrone oxidizing systems (QOS). The resources and composition of hydrogen sulfide-containing gases that need purification and can be raw materials for the production of sulfur or its compounds have been monitored. It is shown that the current technologies of gas purification often do not provide complete purification of gases from H2S, its utilization, are complex, energyintensive, obsolete, and need improvement. The stages of the quinhydrone method of gas purification from H2S, which has experience in industrial applications, but only for the purification of ventilation (oxygen-containing) gases, are analyzed. It is shown that to adapt the method for purification of oxygen-free (natural and technological) gases, it is first necessary to take measures to reduce the negative impact of the oxidation reaction of chemisorbed H2S with O2, accompanied by Na2S2O3 formation, its accumulation, and subsequent processes of waste thiosulfates. The mutual solubility and physicochemical properties of the solution at high concentrations of ingredients in quinhydrone absorbing solution (QAS) were studied. On their basis, theoretical calculations were performed and the choice of mass transfer apparatus was substantiated, which most closely corresponds to the physicochemical bases of oxygen-free gas purification. For purification of gases under atmospheric pressure at the stages of chemisorption of H2S and O2, a horizontal absorber with bucket-shaped dispersants (HABD) is recommended, and for purification under pressure - bubble absorbers. The influence of the conditions of QOS formation on its redox and physicochemical properties has been studied. It is shown that the preparation of QAS based on QOC makes it possible to improve the technology of oxygen-free gases purification from H2S and obtain a given additional product. The phase equilibrium in the H2S - QAS system at different Na2CO3 concentrations was studied. It was found that the phase distribution coefficient mpx increases sharply with increasing saturation of the solution and decreases with increasing Na2CO3 concentration. The equilibrium constant of the H2S chemisorption reaction depends on the initial concentration of Na2CO3 and is equal to 0.1…0.35 mol/(m3.Pa). These data were used to develop a two-stage gas purification scheme. Using the criterion equations and the results of phase equilibrium studies, a mathematical model of H2S chemisorption from gases by QAS in the bubbling model was developed, which takes into account the influence of gas pressure and saturation of H2S solution at different Na2CO3 concentrations. The influence of various factors on the chemisorption of H2S from oxygen-free gases of QAS in bubbling and mechanical dispersing absorbers has been experimentally investigated. It is established that at low degrees of saturation of H2S solution in bubble absorbers the resistance of the system is determined by the resistance from the gas phase. The increase in pressure naturally contributes to the growth of the driving force of the chemisorption process of H2S by QAS. The rate of chemisorption increases with increasing pressure in proportion to Pn (n=0.82…0.83), which is characteristic of systems with "moderately soluble" gas, i.e. those that are limited by resistance from both gas and liquid phases. The value of the linear velocity of the disperser bucket ends (12 m/s) in the HABD was established, at which the resistance from the gas phase has a decisive influence on the kinetics of H2S chemisorption from oxygen-free gases. At the same time, the lowest resistance from the gas phase is achieved at the maximum gas velocities in the absorber 1.8...2.0 m/s. Using the criterion equations, the process of O2 chemisorption from QAS air at the stage of its regeneration in a vertical apparatus with a continuous bubbling layer (VABL) was calculated. The influence of various factors on this process in two types of absorbers - VABL and HABD is experimentally investigated. It is established that the rate of O2 chemisorption of QAS in VABL devices increases with increasing airflow. However, the rate of the chemical reaction between chemisorbed O2 and the reductive form of QOC is much higher (310…430 times) than the rate of O2 chemisorption. Therefore, this type of mass transfer equipment is not recommended for the regeneration of QAS by air oxygen. It is shown that the selective oxidation of chemisorbed H2S with the formation of fine sulfur during electrochemical regeneration of the absorption solution is achieved at low current densities (up to 15…17 A/dm2 ) and the process duration is up to 5 min. At higher densities, due to the increase in pH, by-products are formed (mainly Na2S2O3 and Na2SO4), which impair the sorption properties of QAS. During the electrochemical regeneration of QAS, competing processes of oxidation of chemisorbed H2S and reductive forms of QOC take place, which reduces the efficiency of solution regeneration. In the absence of sulfur compounds in QAS during electrochemical regeneration, the concentration of oxidative forms of QOS increases by 12…30%. It is shown that the decrease in the chemisorption degree of H S when using absorption solutions with a high concentration of Na2S2O3 (up to 350 kg/m3 ) can be compensated by a slight increase in temperature up to 303...308K. This will directly use waste solutions as raw materials for polymer sulfur obtaining. The pH limits (not higher than 8.8… 8.9) are set, at which fine sulfur is obtained with a high yield during gas purification. This is due to the relatively high concentration of NaHCO3 compared to Na2CO3 in the absorbing solution. Variants of technological schemes for purification of natural, associated, coke, pyrolysis, bio, and other gases with the production of fine sulfur and the possibility of combining these technologies with polymeric sulfur technology, which increases the economic efficiency of quinhydrone method gas desulfurization process.
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Книги з теми "Oxidized system"

1

Paxson, Daniel E. A model for the space shuttle main engine high pressure oxidizer turbopump shaft seal system. [Washington, DC]: National Aeronautics and Space Administration, 1991.

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2

Aerospace Fuel Oil & Oxidizer Systems Handbook/Afo-Hb. Society of Automotive Engineers, 1993.

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3

United States. National Aeronautics and Space Administration., ed. Advanced launch system advanced development oxidizer turbopump program: Final report. West Palm Beach, Fla: United Technologies, Pratt & Whitney, 1993.

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United States. National Aeronautics and Space Administration., ed. An SSME high pressure oxidizer turboprop diagnostic system using G2tm real-time expert system. [Washington, DC]: National Aeronautics and Space Administration, 1991.

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An SSME high pressure oxidizer turboprop diagnostic system using G2tm real-time expert system. [Washington, DC]: National Aeronautics and Space Administration, 1991.

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6

Advanced launch system advanced development oxidizer turbopump orprogram: Technical implementation plan. West Palm Beach, Fla: United Technologies, Pratt & Whitney, 1989.

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7

Center, Huntsville Engineering, and United States. National Aeronautics and Space Administration., eds. Fluid flow analysis of the SSME high pressure fuel and oxidizer turbine coolant systems. Huntsville, AL: Lockheed Missiles & Space Company, Inc., Huntsville Engineering Center, 1990.

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8

High heat transfer oxidizer heat exchanger design and analysis: Final report, Jan. 1985 - Oct. 1986. [Cleveland, Ohio: NASA Lewis Research Center, 1987.

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9

Kirchman, David L. Processes in anoxic environments. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198789406.003.0011.

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During organic material degradation in oxic environments, electrons from organic material, the electron donor, are transferred to oxygen, the electron acceptor, during aerobic respiration. Other compounds, such as nitrate, iron, sulfate, and carbon dioxide, take the place of oxygen during anaerobic respiration in anoxic environments. The order in which these compounds are used by bacteria and archaea (only a few eukaryotes are capable of anaerobic respiration) is set by thermodynamics. However, concentrations and chemical state also determine the relative importance of electron acceptors in organic carbon oxidation. Oxygen is most important in the biosphere, while sulfate dominates in marine systems, and carbon dioxide in environments with low sulfate concentrations. Nitrate respiration is important in the nitrogen cycle but not in organic material degradation because of low nitrate concentrations. Organic material is degraded and oxidized by a complex consortium of organisms, the anaerobic food chain, in which the by-products from physiological types of organisms becomes the starting material of another. The consortium consists of biopolymer hydrolysis, fermentation, hydrogen gas production, and the reduction of either sulfate or carbon dioxide. The by-product of sulfate reduction, sulfide and other reduced sulfur compounds, is oxidized back eventually to sulfate by either non-phototrophic, chemolithotrophic organisms or by phototrophic microbes. The by-product of another main form of anaerobic respiration, carbon dioxide reduction, is methane, which is produced only by specific archaea. Methane is degraded aerobically by bacteria and anaerobically by some archaea, sometimes in a consortium with sulfate-reducing bacteria. Cultivation-independent approaches focusing on 16S rRNA genes and a methane-related gene (mcrA) have been instrumental in understanding these consortia because the microbes remain uncultivated to date. The chapter ends with some discussion about the few eukaryotes able to reproduce without oxygen. In addition to their ecological roles, anaerobic protists provide clues about the evolution of primitive eukaryotes.
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10

Nonlinear control of a reusable rocket engine for life extension. [Cleveland, Ohio]: National Aeronautics and Space Administration, Lewis Research Center, 1998.

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Частини книг з теми "Oxidized system"

1

Czubryt, M. P., V. Panagia, and G. N. Pierce. "The roles of free radicals, peroxides and oxidized lipoproteins in second messenger system dysfunction." In Myocardial Ischemia: Mechanisms, Reperfusion, Protection, 57–69. Basel: Birkhäuser Basel, 1996. http://dx.doi.org/10.1007/978-3-0348-8988-9_4.

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2

Shaw, Anthony Peter Gordon. "Zirconium–Oxidizer Systems." In Thermitic Thermodynamics, 363–402. Boca Raton : CRC Press, [2020]: CRC Press, 2020. http://dx.doi.org/10.1201/9781351056625-10.

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Shaw, Anthony Peter Gordon. "Hafnium–Oxidizer Systems." In Thermitic Thermodynamics, 403–41. Boca Raton : CRC Press, [2020]: CRC Press, 2020. http://dx.doi.org/10.1201/9781351056625-11.

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Shaw, Anthony Peter Gordon. "Vanadium–Oxidizer Systems." In Thermitic Thermodynamics, 443–83. Boca Raton : CRC Press, [2020]: CRC Press, 2020. http://dx.doi.org/10.1201/9781351056625-12.

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Shaw, Anthony Peter Gordon. "Niobium–Oxidizer Systems." In Thermitic Thermodynamics, 485–525. Boca Raton : CRC Press, [2020]: CRC Press, 2020. http://dx.doi.org/10.1201/9781351056625-13.

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Shaw, Anthony Peter Gordon. "Tantalum–Oxidizer Systems." In Thermitic Thermodynamics, 527–60. Boca Raton : CRC Press, [2020]: CRC Press, 2020. http://dx.doi.org/10.1201/9781351056625-14.

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Shaw, Anthony Peter Gordon. "Chromium–Oxidizer Systems." In Thermitic Thermodynamics, 561–92. Boca Raton : CRC Press, [2020]: CRC Press, 2020. http://dx.doi.org/10.1201/9781351056625-15.

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8

Shaw, Anthony Peter Gordon. "Molybdenum–Oxidizer Systems." In Thermitic Thermodynamics, 593–615. Boca Raton : CRC Press, [2020]: CRC Press, 2020. http://dx.doi.org/10.1201/9781351056625-16.

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9

Shaw, Anthony Peter Gordon. "Tungsten–Oxidizer Systems." In Thermitic Thermodynamics, 617–39. Boca Raton : CRC Press, [2020]: CRC Press, 2020. http://dx.doi.org/10.1201/9781351056625-17.

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10

Shaw, Anthony Peter Gordon. "Manganese–Oxidizer Systems." In Thermitic Thermodynamics, 641–74. Boca Raton : CRC Press, [2020]: CRC Press, 2020. http://dx.doi.org/10.1201/9781351056625-18.

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Тези доповідей конференцій з теми "Oxidized system"

1

Hu, Lingxiang, and Fei Zhuge. "Ultrasensitive Memristive Synapses Based on Lightly Oxidized Sulfide Films." In Information Storage System and Technology. Washington, D.C.: OSA, 2017. http://dx.doi.org/10.1364/isst.2017.isu4b.4.

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2

LIASHENKO, Oleksii, and Fiqiri HODAJ. "Thermodynamic and kinetic factors governing wetting of oxidized and deoxidized Cu surfaces by liquid Sn." In 2020 IEEE 8th Electronics System-Integration Technology Conference (ESTC). IEEE, 2020. http://dx.doi.org/10.1109/estc48849.2020.9229823.

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3

Han, Tao, Hui Hong, Hongguang Jin, and Chuanqiang Zhang. "An Advanced Power-Generation System With CO2 Recovery Integrating Dimethyl Ether (DME) Fueled Chemical-Looping Combustion." In ASME 2010 4th International Conference on Energy Sustainability. ASMEDC, 2010. http://dx.doi.org/10.1115/es2010-90199.

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Dimethyl ether (DME) is a promising alternative fuel, but direct combustion of DME will result in extra energy penalty for CO2 separation. In this paper, an advanced power-generation system with CO2 recovery integrating DME-fueled chemical-looping combustion is proposed. In the reduction reactor, DME is oxidized by Fe2O3 into CO2 and H2O, and Fe2O3 is reduced into FeO simultaneously. Since the endothermic reduction of Fe2O3 with DME requires relatively low-grade thermal energy around 180°C, waste heat is used to provide the reaction heat. FeO is oxidized into Fe2O3 by air in the oxidation reactor, producing high-temperature flue gas to generate electricity through a thermal cycle. The gas production from the fuel reactor only consists of CO2 and H2O, so CO2 can be easily separated through condensing with no extra energy penalty. As a result, the thermal efficiency could be expected to be 58.6% at a turbine inlet temperature of 1288°C. Additionally, experiments on DME-fueled Chemical-looping combustion are carried out to verify the feasibility of the core process. This proposed system may provide a new approach for high efficient use of DME in the industrial fields, and offer a possibility of chemical-looping combustion with inherent CO2 capture for the alternative fuel.
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4

Richard, Åse, Oliver Klett, Carola Strandman, Ylva Bäcklund, and Leif Nyholm. "Design of a Chip Based Microanalytical Fluidic System Based on Electrochemical Detection Using Redox Cycling." In ASME 1999 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1999. http://dx.doi.org/10.1115/imece1999-0313.

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Abstract Microelectrodes on a chip have been investigated regarding their usefulness for dual electrode amperometric detection in off-chip and on-chip based microanalytical capillary flow systems. In the latter case, microelectrodes were integrated on a chip containing fluidic channels. A straightforward method to micromechanically manufacture the chips is presented. In this process, the microelectrodes are manufactured on a Pyrex (Corning #7740) glass wafer and anodically bonded to an oxidized silicon wafer into which fluidic channels of varying width and depth have been manufactured.
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5

Engeda, Abraham. "A Regenerative Flow Compressor as a Secondary Air Pump for Engine Emission Control." In ASME Turbo Expo 2010: Power for Land, Sea, and Air. ASMEDC, 2010. http://dx.doi.org/10.1115/gt2010-22087.

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The automotive engine requires a relatively rich mixture of fuel and air for smooth operation on cold start. Exhaust gases contain high levels of carbon monoxide and hydrocarbons after cold starts. The unburned hydrocarbons could be further oxidized, except there is no oxygen left after combustion. Using a Secondary Air Pump (SAP), air is fed into the exhaust manifold (secondary air), the CO and HC are oxidized through afterburning at temperatures over 600°C to form water and carbon dioxide. An activated secondary air injection system leads to an increase in oxygen content in the exhaust system. This paper discuses the performance of a Regenerative Flow Compressor (RFC) for SAP application and shows the RFC to be the best choice for satisfying the required specification of the SAP.
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6

Altunina, N. V. "Autoantibodies to oxidized LDL level according to insulin resistance in patients with diabetes mellitus and chronic coronary syndrome." In MODERN MEDICINE: THE USE OF CREATIVE INDUSTRIES IN THE HEALTHCARE SYSTEM. Baltija Publishing, 2021. http://dx.doi.org/10.30525/978-9934-26-182-4-3.

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7

Boren, Richard M., Charles F. Hammel, and Mark R. Bleckinger. "Multi-Pollution Removal System Using Oxides of Manganese." In ASME 2004 Power Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/power2004-52081.

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Pending legislation suggests there will be a need for increased removal of NOx, SO2, Hg (Mercury) and PM 2.5 from coal-fired power plants. Current commercial technologies only handle one of these pollutants so several different technologies must be combined to remove all of these pollutants. The Pahlman™ Process developed by Enviroscrub Technologies removes NOx, SO2 and Hg in one step. The Pahlman™ Process is a sorbent-based technology, which utilizes a proprietary Oxides of Manganese compound to remove SO2, NOx and Hg. The sorbent is spray-dried into the exhaust duct downstream of the current particulate control device. Spray drying is used to control the particle size (40 micron mean) and increases the surface area of the particle (∼300 m2 /gram). The sorbent is collected in a fabric filter baghouse, which serves two purposes: (1) it captures the entrained sorbent and (2) provides additional residence time for gas-solid contact between the sorbent and the target pollutants. The loaded sorbent is removed from the baghouse and routed to regeneration. Sorbent regeneration occurs in an aqueous solution under temperature and pressure while the solution is maintained in the proper pH and Eh ranges. The reacted manganese is oxidized back to its starting state and sulfate and nitrate byproduct compounds are produced. The insoluble oxides of manganese are then filtered out of the solution and returned to the spray-dryer for re-use. The soluble sulfate and nitrate compounds are separated and the nitrate by-products are sold as fertilizer. The sulfates are further processed and re-used in the regeneration process with excess sulfate by-products sold as fertilizer or used to produce sulfuric acid. Testing over the last three years has resulted in consistent SO2 removal of over 99% and NOx removal of greater than 95%. Testing performed in June 2003 at DTE Energy’s River Rouge Power Station Unit#3 in Detroit, Michigan showed removal rates of >99% for SO2, >98% for NOx and 97% for oxidized Mercury (Hg2+). Mercury testing was performed by the Energy and Environmental Research Center (EERC) and paid for by DTE Energy and the DOE. Testing performed in December 2003 through January 2004 at Minnesota Power’s Boswell Energy Center Unit#4 in Cohasset, Minnesota showed removal rates of >98% for SO2, >94% for NOx and 99.2% for elemental (Hg0) and 94% for total Mercury (HgT).
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8

Bharath, Anand Nageswaran, Nitya Kalva, Rolf D. Reitz, and Christopher J. Rutland. "Use of Early Exhaust Valve Opening to Improve Combustion Efficiency and Catalyst Effectiveness in a Multi-Cylinder RCCI Engine System: A Simulation Study." In ASME 2014 Internal Combustion Engine Division Fall Technical Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/icef2014-5534.

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Low Temperature Combustion (LTC) strategies such as Reactivity Controlled Compression Ignition (RCCI) can result in significant improvements of fuel economy and emissions reduction. However, they can produce significant carbon monoxide and unburnt hydrocarbon emissions at low load operating conditions due to poor combustion efficiencies at these operating points, which is a consequence of the low combustion temperatures that cause the oxidation rates of these species to slow down. The exhaust gas temperature is also not high enough at low loads for effective performance of turbocharger systems and diesel oxidation catalysts (DOC). The DOC is extremely sensitive to exhaust gas temperature changes and lights off only when a certain temperature is reached, depending on the catalyst specifications. Uncooled EGR can increase combustion temperatures, thereby improving combustion efficiency, but high EGR concentrations of 50% or more are required, thereby increasing pumping work and reducing volumetric efficiency. However, with early exhaust valve opening, the exhaust gas temperature can be much higher, allowing lower EGR flow rates, and enabling activation of the DOC for more effective oxidization of unburnt hydrocarbons and CO in the exhaust. In this paper, a multi-cylinder engine system simulation of RCCI at low load operation with early exhaust valve opening is presented, along with consideration of the exhaust aftertreatment system. The combustion process is modeled using the 3D CFD code, KIVA, and the heat release rates obtained from this combustion are used in a GT-Power model of a turbocharged, multi-cylinder light-duty RCCI engine for a full system simulation. The post-turbine exhaust gas is fed into GT-Power’s aftertreatment model of the engine’s DOC to determine the catalyst response. It is confirmed that opening the exhaust valve earlier increases the exhaust gas temperature, and hence lower EGR flow rates are needed to improve combustion efficiency. It was also found that exhaust temperatures of around 457 K are required to light off the catalyst and oxidize the unburnt hydrocarbons and CO effectively. Performance of the DOC was drastically improved and higher amounts of unburnt hydrocarbons were oxidized by increasing the exhaust gas temperature.
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9

Hong, Hui, Ying Pan, Xiaosong Zhang, Tao Han, Shuo Peng, and Hongguang Jin. "A Solar-Hybrid Power Plant Integrated With Ethanol Chemical-Looping Combustion." In ASME 2011 Turbo Expo: Turbine Technical Conference and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/gt2011-45600.

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In this paper, a new solar hybrid gas turbine cycle integrating ethanol-fueled chemical-looping combustion (CLC) has been proposed, and the system was investigated with the aid of the Energy-Utilization Diagram (EUD). Chemical-looping combustion consists of two successive reactions: first, ethanol fuel is oxidized by metal oxide (NiO) as an oxygen carrier (reduction of metal oxide); secondly, the reduced metal (Ni) is successively oxidized by combustion air (the oxidation of metal). The reduction of NiO with ethanol requires a relative low-grade thermal energy at 150–200°C. Then concentrated solar thermal energy at approximately 200–300°C can be utilized to provide the process heat for this reaction. The integration of solar thermal energy and CLC could make the exergy efficiency and the net solar-to-electric efficiency of the system more than 54% and 28% at a turbine inlet temperature (TIT) of 1288°C, respectively. At the same time, the variation in the overall thermal efficiency (η) of the system with varying key parameters was analyzed, such as Turbine Inlet Temperature, pressure ratio (π) and the temperature of reduction reactor. Additionally, preliminary experiments on ethanol-fueled chemical-looping combustion are carried out to verify the feasibility of the key process. The promising results obtained here indicate that this novel gas turbine cycle with ethanol-fueled chemical-looping combustion could provide a promising approach of both efficient use of alternative fuel and low-temperature solar thermal and offer a technical probability of combining the chemical-looping combustion with inherent CO2 capture for the alternative fuel.
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10

Liang, Xingyu, Yu Chen, Lihui Dong, and Chonglin Song. "Investigation on Amorphous Particles Evolution of the Diesel Engine." In ASME 2012 Internal Combustion Engine Division Spring Technical Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/ices2012-81054.

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Analysis of the changes in mass and size of particles formed during the diesel combustion process, the morphological characteristics, and the trace elements within these amorphous particles was carried out using a total cylinder sampling system installed on a direct injection diesel engine. Utilizing field emission transmission electron microscope technology, the results showed that the amorphous particles formed during the combustion process were abundant in metallic and non-metallic elements mainly derived from the lubrication oil, which was found to have entered the combustion process, oxidized and combusted, further increasing the absorbed carbon particles during the later stages of combustion.
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Звіти організацій з теми "Oxidized system"

1

Lahav, Ori, Albert Heber, and David Broday. Elimination of emissions of ammonia and hydrogen sulfide from confined animal and feeding operations (CAFO) using an adsorption/liquid-redox process with biological regeneration. United States Department of Agriculture, March 2008. http://dx.doi.org/10.32747/2008.7695589.bard.

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The project was originally aimed at investigating and developing new efficient methods for cost effective removal of ammonia (NH₃) and hydrogen sulfide (H₂S) from Concentrated Animal Feeding Operations (CAFO), in particular broiler and laying houses (NH₃) and hog houses (H₂S). In both cases, the principal idea was to design and operate a dedicated air collection system that would be used for the treatment of the gases, and that would work independently from the general ventilation system. The advantages envisaged: (1) if collected at a point close to the source of generation, pollutants would arrive at the treatment system at higher concentrations; (2) the air in the vicinity of the animals would be cleaner, a fact that would promote animal growth rates; and (3) collection efficiency would be improved and adverse environmental impact reduced. For practical reasons, the project was divided in two: one effort concentrated on NH₃₍g₎ removal from chicken houses and another on H₂S₍g₎ removal from hog houses. NH₃₍g₎ removal: a novel approach was developed to reduce ammonia emissions from CAFOs in general, and poultry houses in particular. Air sucked by the dedicated air capturing system from close to the litter was shown to have NH₃₍g₎ concentrations an order of magnitude higher than at the vents of the ventilation system. The NH₃₍g₎ rich waste air was conveyed to an acidic (0<pH<~5) bubble column reactor where NH₃ was converted to NH₄⁺. The reactor operated in batch mode, starting at pH 0 and was switched to a new acidic absorption solution just before NH₃₍g₎ breakthrough occurred, at pH ~5. Experiments with a wide range of NH₃₍g₎ concentrations showed that the absorption efficiency was practically 100% throughout the process as long as the face velocity was below 4 cm/s. The potential advantages of the method include high absorption efficiency, lower NH₃₍g₎ concentrations in the vicinity of the birds, generation of a valuable product and the separation between the ventilation and ammonia treatment systems. A small scale pilot operation conducted for 5 weeks in a broiler house showed the approach to be technically feasible. H₂S₍g₎ removal: The main goal of this part was to develop a specific treatment process for minimizing H₂S₍g₎ emissions from hog houses. The proposed process consists of three units: In the 1ˢᵗ H₂S₍g₎ is absorbed into an acidic (pH<2) ferric iron solution and oxidized by Fe(III) to S⁰ in a bubble column reactor. In parallel, Fe(III) is reduced to Fe(II). In the 2ⁿᵈ unit Fe(II) is bio-oxidized back to Fe(III) by Acidithiobacillus ferrooxidans (AF).In the 3ʳᵈ unit S⁰ is separated from solution in a gravity settler. The work focused on three sub-processes: the kinetics of H₂S absorption into a ferric solution at low pH, the kinetics of Fe²⁺ oxidation by AF and the factors that affect ferric iron precipitation (a main obstacle for a continuous operation of the process) under the operational conditions. H₂S removal efficiency was found higher at a higher Fe(III) concentration and also higher for higher H₂S₍g₎ concentrations and lower flow rates of the treated air. The rate limiting step of the H₂S reactive absorption was found to be the chemical reaction rather than the transition from gas to liquid phase. H₂S₍g₎ removal efficiency of >95% was recorded with Fe(III) concentration of 9 g/L using typical AFO air compositions. The 2ⁿᵈ part of the work focused on kinetics of Fe(II) oxidation by AF. A new lab technique was developed for determining the kinetic equation and kinetic parameters (KS, Kₚ and mₘₐₓ) for the bacteria. The 3ʳᵈ part focused on iron oxide precipitation under the operational conditions. It was found that at lower pH (1.5) jarosite accumulation is slower and that the performance of the AF at this pH was sufficient for successive operation of the proposed process at the H₂S fluxes predicted from AFOs. A laboratory-scale test was carried out at Purdue University on the use of the integrated system for simultaneous hydrogen sulfide removal from a H₂S bubble column filled with ferric sulfate solution and biological regeneration of ferric ions in a packed column immobilized with enriched AFbacteria. Results demonstrated the technical feasibility of the integrated system for H₂S removal and simultaneous biological regeneration of Fe(III) for potential continuous treatment of H₂S released from CAFO. NH₃ and H₂S gradient measurements at egg layer and swine barns were conducted in winter and summer at Purdue. Results showed high potential to concentrate NH₃ and H₂S in hog buildings, and NH₃ in layer houses. H₂S emissions from layer houses were too low for a significant gradient. An NH₃ capturing system was designed and tested in a 100-chicken broiler room. Five bell-type collecting devices were installed over the litter to collect NH₃ emissions. While the air extraction system moved only 10% of the total room ventilation airflow rate, the fraction of total ammonia removed was 18%, because of the higher concentration air taken from near the litter. The system demonstrated the potential to reduce emissions from broiler facilities and to concentrate the NH₃ effluent for use in an emission control system. In summary, the project laid a solid foundation for the implementation of both processes, and also resulted in a significant scientific contribution related to AF kinetic studies and ferrous analytical measurements.
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2

Rempel, K. U., A. E. Williams-Jones, and K. Fuller. An experimental investigation of the solubility and speciation of uranium in hydrothermal ore fluids. Natural Resources Canada/CMSS/Information Management, 2021. http://dx.doi.org/10.4095/328995.

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Experimental data on the solubility and speciation of uranium in hydrothermal solution is required to improve genetic models for the formation of ore deposits, yet very few data of this type have been published. Of particular interest is the oxidation state of the uranium in solution, as conventional wisdom suggests that U is dissolved in the oxidized U(VI) state and precipitated as reduced U(IV) minerals, yet recent experiments have shown ppm-level solubility for U(IV). This study investigated the mobility of reduced U(IV) and oxidized U(VI) in acidic (pH = 2), fluoride- bearing and alkaline (pH = 10), chloride-bearing solutions at 100-200°C and 1 to 15.8 bars (0.1-1.58 MPa). Preliminary data for the mobility of U(IV) in pH 2 fluids with 0.01 m F- show concentrations of 1.76 to 3.92 ppm U at 200°C, indicating that, contrary to common belief, the reduced U(IV) can be transported in solution. We have also conducted experiments on U(VI) solubility in pH 2 fluoride-bearing, and pH 10 chloride-bearing solutions. Uranium concentrations in the F- -bearing experiments ranged from 624 to 1570 ppm (avg. 825 ppm, n = 6) at 100°C, 670 to 1560 ppm (avg. 931 ppm, n = 4) at 150°C, and 3180 to 7550 ppm (avg. 5240, n = 9) at 200°C. In comparison, U concentrations in the Cl- -bearing runs range from 86.1 to 357 ppm (avg. 185 ppm, n = 15) at 200°C. Clearly, oxidized U(VI) is very readily mobilized in hydrothermal fluids. However, the measured concentrations of U(VI) are independent of those of F- or Cl-, suggesting the formation of U oxide or hydroxide species rather than U chlorides or fluorides. These experimental data will be verified and supplemented in future experiments, which will be used to derive the stoichiometry and thermodynamic constants for the dominant uranium species in hydrothermal solutions. The data from this study will then be integrated into a comprehensive genetic model for uranium ore-forming systems.
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3

O'Neill, Sharman, Abraham Halevy, and Amihud Borochov. Molecular Genetic Analysis of Pollination-Induced Senescence in Phalaenopsis Orchids. United States Department of Agriculture, 1991. http://dx.doi.org/10.32747/1991.7612837.bard.

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The project investigated the molecular genetic and biochemical basis of pollination-induced senescence of Phalaenopsis flowers. This experimental system offered unique advantages in that senescence is strictly regulated by pollination, providing the basis to experimentally initiate and synchronize senescence in populations of flowers. The postpollination syndrome in the Phalaenopsis orchid system was dissected by investigating the temporal and spatial regulation of ACC synthase gene expression. In the stigma, pollen-borne auxin induces the expression of the auxin-regulated ACC synthase (PS-ACS2) gene, resulting in ACC synthesis within 1 h following pollination. Newly formed ACC is oxidized by basal constitutive ACC oxidase to ethylene, which then induces the expression of the ethylene-regulated ACC synthase(PS-ACS1) and oxidase (ACO1) genes for further autocatalytic production of ethylene. It is speculated that during the 6-h period following pollination, emasculation leads to the production or release of a sensitivity factor that sensitizes the cells of the stigma to ethylene. ACC and ethylene molecules are translocated from the stigma to the labellum and perianth where ethylene induces the expression of PS-ACS1 and ACO1 resulting in an increased production of ACC and ethylene. Organ-localized ethylene is responsible for inrolling and senescence of the labellum and perianth. The regulation of ethylene sensitivity and signal transduction events in pollinated flowers was also investigated. The increase in ethylene sensitivity appeared in both the flower column and the perianth, and was detected as early as 4 h after pollination. The increase in ethylene sensitivity following pollination was not dependent on endogenous ethylene production. Application of linoleic and linoleic acids to Phalaenopsis and Dendrobium flowers enhanced their senescence and promoted ethylene production. Several major lipoxygenase pathway products including JA-ME, traumatic acid, trans-2-hexenal and cis-3-hexenol, also enhanced flower senescence. However, lipoxygenase appears to not be directly involved in the endogenous regulation of pollination-induced Phalaenopsis and Dendrobium flower senescence. The data suggest that short-chain saturated fatty acids may be the ethylene "sensitivity factors" produced following pollination, and that their mode of action involves a decrease in the order of specific regions i the membrane lipid bilayer, consequently altering ethylene action. Examination of potential signal transduction intermediates indicate a direct involvement of GTP-binding proteins, calcium ions and protein phosphorylation in the cellular signal transduction response to ethylene following pollination. Modulations of cytosolic calcium levels allowed us to modify the flowers responsiveness to ethylene.
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4

Van Rijn, Jaap, Harold Schreier, and Yossi Tal. Anaerobic ammonia oxidation as a novel approach for water treatment in marine and freshwater aquaculture recirculating systems. United States Department of Agriculture, December 2006. http://dx.doi.org/10.32747/2006.7696511.bard.

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Ammonia waste removal in recirculating aquaculture systems is typically accomplished via the action of nitrifying bacteria in specially designed biofilters that oxidize ammonia to produce nitrate. In the majority of these systems nitrate is discharged to the environment through frequent water exchanges. As environmental considerations have made it necessary to eliminate nitrate release, new strategies for nitrate consumption are being developed. In the funding period we showed that ammonia removal from wastewater could take place by an anaerobic ammonia oxidation process carried out by bacterial Planctomycetessp. Referred to as “anammox”, this process occurs in the absence of an organic source and in the presence of nitrite (or nitrate) as an electron acceptor as follows: NH₃ + HNO₂ -> N₂ + 2H₂O. Annamox has been estimated to result in savings of up to 90% of the costs associated with was wastewater treatment plants. Our objective was to study the applicability of the anammox process in a variety of recirculating aquaculture systems to determine optimal conditions necessary for efficient ammonia waste removal. Both seawater and freshwater systems operated with either conventional aerobic treatment of ammonia to nitrate (USA) or, in addition, denitrifying biofilters as well as anaerobic digestion of sludge (Israel) were tested. Molecular tools were used to screen and monitor different treatment compartments for the presence of Planctomycetes. Optimal conditions for the enrichment of the anammox bacteria were tested using laboratory scale biofilters as well as a semi-commercial system. Enrichment studies resulted in the isolation of some unique heterotrophic bacteria capable of plasmid-mediated autotrophic growth in the presence of ammonia and nitrite. Our studies have not only demonstrated the presence and viability of Planctomycetes spp. in recirculating marine and freshwater systems biofilter units but also demonstrated the applicability of the anammox process in these systems. Using our results we have developed treatment schemes that have allowed for optimizing the anammox process and applying it to recirculating systems.
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5

Neyedley, K., J. J. Hanley, Z. Zajacz, and M. Fayek. Accessory mineral thermobarometry, trace element chemistry, and stable O isotope systematics, Mooshla Intrusive Complex (MIC), Doyon-Bousquet-LaRonde mining camp, Abitibi greenstone belt, Québec. Natural Resources Canada/CMSS/Information Management, 2021. http://dx.doi.org/10.4095/328986.

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The Mooshla Intrusive Complex (MIC) is an Archean polyphase magmatic body located in the Doyon-Bousquet-LaRonde (DBL) mining camp of the Abitibi greenstone belt, Québec, that is spatially associated with numerous gold (Au)-rich VMS, epizonal 'intrusion-related' Au-Cu vein systems, and shear zone-hosted (orogenic?) Au deposits. To elucidate the P-T conditions of crystallization, and oxidation state of the MIC magmas, accessory minerals (zircon, rutile, titanite) have been characterized using a variety of analytical techniques (e.g., trace element thermobarometry). The resulting trace element and oxythermobarometric database for accessory minerals in the MIC represents the first examination of such parameters in an Archean magmatic complex in a world-class mineralized district. Mineral thermobarometry yields P-T constraints on accessory mineral crystallization consistent with the expected conditions of tonalite-trondhjemite-granite (TTG) magma genesis, well above peak metamorphic conditions in the DBL camp. Together with textural observations, and mineral trace element data, the P-T estimates reassert that the studied minerals are of magmatic origin and not a product of metamorphism. Oxygen fugacity constraints indicate that while the magmas are relatively oxidizing (as indicated by the presence of magmatic epidote, titanite, and anhydrite), zircon trace element systematics indicate that the magmas were not as oxidized as arc magmas in younger (post-Archean) porphyry environments. The data presented provides first constraints on the depth and other conditions of melt generation and crystallization of the MIC. The P-T estimates and qualitative fO2 constraints have significant implications for the overall model for formation (crystallization, emplacement) of the MIC and potentially related mineral deposits.
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6

Amir, Rachel, David J. Oliver, Gad Galili, and Jacline V. Shanks. The Role of Cysteine Partitioning into Glutathione and Methionine Synthesis During Normal and Stress Conditions. United States Department of Agriculture, January 2013. http://dx.doi.org/10.32747/2013.7699850.bard.

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The objective of this research is to study the nature of the competition for cysteine (Cys), the first organic sulfur-containing compound, between its two main metabolites, glutathione (GSH) and methionine (Met). GSH plays a central role in protecting plants during various stresses, while Met, an essential amino acid, regulates essential processes and metabolites in plant cells through its metabolite S-adenosyl-Met. Our results, which are based on flux analysis and measurements of Met- metabolites, show that the flux towards Met synthesis is high during non-stress conditions, however the flux is significantly reduced under stress conditions, when there is high synthesis of GSH. Under oxidative stress the expression level of the regulatory enzyme of Met synthesis, cystathionine g-synthase (CGS) was reduced. By using three different systems, we have found that that GSH down regulates the expression level of CGS, thus reducing Met synthesis. We have found that this regulation occurs at the post-transcriptional level, and further studies have shown that it occurs at post-translationaly. To reveal how oxidative stress affects the flux towards Met and GSH, flux analysis was performed. We have found that the level of Met is significantly reduced, while the level of glutathione significantly increases during stress. Under stress conditions most of the glutathione is converted from GSH to GSSG (the oxidised form of glutathione). These results suggest that under normal growth conditions, Cys is channelled towards both pathways to support GSH accumulation and the synthesis of growth-essential Met metabolites. However, during oxidative stress, when a high level of GSH is required to protect the plants, the levels of GSH increase while those of CGS are reduced. This reduction leaves more Cys available for GSH synthesis under stress conditions. In addition we have also studied the effects of high GSH level on the transcriptome profile. The analysis revealed that GSH affects the expression level of many major genes coding to enzymes or proteins associated with photosynthesis, starch degradation, hormone metabolism (especially genes associated with jasmonate), biotic stress (especially genes associated with PR-proteins), cytochrome P450 genes, regulation of transcription and signaling (especially genes associated with receptor kinases and calcium). These results suggest that indeed GSH levels affect different pathways and metabolites in plants.
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7

Rouseff, Russell L., and Michael Naim. Characterization of Unidentified Potent Flavor Changes during Processing and Storage of Orange and Grapefruit Juices. United States Department of Agriculture, September 2002. http://dx.doi.org/10.32747/2002.7585191.bard.

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Citrus juice flavor quality traditionally diminishes after thermal processing and continuously during storage. Our prior studies found that four of the five most potent off-aromas formed during orange juice storage had not been identified. The primary emphasis of this project was to characterize and identify those potent flavor degrading aroma volatiles so that methods to control them could be developed and final flavor quality improved. Our original objectives included: 1 Isolate and characterize the most important unidentified aroma impact compounds formed or lost during pasteurization and storage. 2. Determination of thiamine and carotenoid thermal decomposition and Strecker degradation pathways in model solutions as possible precursors for the unidentified off-flavors. 3. Evaluate the effectiveness of an "electronic nose" to differentiate the headspace aromas of from untreated and heat pasteurized orange and grapefruit juices. 4. Use model systems of citrus juices to investigate the three possible precursor pathways (from 2) for flavor impact compounds formed or lost during pasteurization or storage. RESULTS - The components responsible for citrus storage off flavors and their putative precursors have now been identified. Certain carotenoids (b-carotene) can thermally degrade to produce b-ionone and b-damascenone which are floral and tobacco smelling respectively. Our GC-O and sensory experiments indicated that b-damascenone is a potential storage off-flavor in orange juice. Thiamine (Vitamin B1) degradation produces 2-methyl-3-furan thiol, MFT, and its dimer bis(2- methyl-3-furyl) disulfide which both produce meaty, savory aromas. GC-O and sensory studies indicated that MFT is another storage off-flavor. Methional (potato aroma) is another off flavor produced primarily from the reaction of the native amino acid, methionine, and oxidized ascorbic acid (vitamin C). This is a newly discovered pathway for the production of methional and is more dominant in juices than the classic Maillard reaction. These newly identified off flavors diminish the flavor quality of citrus juices as they distort the flavor balance and introduce non-typical aromas to the juice flavor profile. In addition, we have demonstrated that some of the poor flavor quality citrus juice found in the market place is not only from the production of these and other off flavors but also due to the absence of desirable flavor components including several potent aldehydes and a few esters. The absence of these compounds appears to be due to incomplete flavor volatile restoration after the making of juice concentrates. We are the first to demonstrate that not all flavor volatiles are removed along with water in the production of juice concentrate. In the case of grapefruit juice we have documented which flavor volatiles are completely removed, which are partially removed and which actually increase because of the thermal process. Since more that half of all citrus juices is made into concentrate, this information will allow producers to more accurately restore the original flavor components and produce a juice with a more natural flavor. IMPLICATIONS - We have shown that the aroma of citrus juices is controlled by only 1-2% of the total volatiles. The vast majority of other volatiles have little to no direct aroma activity. The critical volatiles have now been identified. The ability to produce high quality citrus juices requires that manufacturers know which chemical components control aroma and flavor. In addition to identifying the critical flavor components (both positive and negative), we have also identified several precursors. The behavior of these key aroma compounds and their precursors during common manufacturing and storage conditions has been documented so manufacturers in Israel and the US can alter production practices to minimize the negative ones and maximize the positive ones.
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