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Статті в журналах з теми "Aqueous byproduct"
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López-Salas, Lucía, Inés Cea, Isabel Borrás-Linares, Tatiana Emanuelli, Paz Robert, Antonio Segura-Carretero, and Jesús Lozano-Sánchez. "Preliminary Investigation of Different Drying Systems to Preserve Hydroxytyrosol and Its Derivatives in Olive Oil Filter Cake Pressurized Liquid Extracts." Foods 10, no. 6 (June 18, 2021): 1407. http://dx.doi.org/10.3390/foods10061407.
Повний текст джерелаАнотація:
Phenolic compounds present in extra virgin olive oil (EVOO) could be retained in its byproducts during processing. Among them, hydroxytyrosol and its derivatives deserve special attention due to their health benefits recognized by The European Food Safety Authority (EFSA). In the present research, the presence of these compounds in the filter cake byproduct was studied by combining pressurized liquid extraction (PLE) and high-performance liquid chromatography coupled to time-of-flight mass spectrometry (HPLC-TOF-MS). The applied optimum extraction parameters were 1500 psi, 120 °C and aqueous ethanol (50:50, v/v). The influence of different drying methods (vacuum-, freeze- and spray-drying) in the recovery of phenolic compounds was also evaluated. A total of 16 compounds from EVOO were identified in the extracts, 3 of them being hydroxytyrosol-related compounds, 6 substances of oleoside and elenolic acid derivatives, together with 6 secoiridoids and 1 lignan. The results highlighted the great number of phenolic compounds recovered from filter cake with these techniques, being even higher than the reported content in EVOO and other byproducts. The combination of PLE and freeze-drying resulted in being the best procedure for the recovery of phenolic compounds from filter cake byproduct.
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Appiagyei, Benjamin, Souful Bhatia, Gabriela L. Keeney, Troy Dolmetsch, and James E. Jackson. "Electroactivated alkylation of amines with alcohols via both direct and indirect borrowing hydrogen mechanisms." Green Chemistry 22, no. 3 (2020): 860–69. http://dx.doi.org/10.1039/c9gc03747k.
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Sevimli-Gur, Canan, Yuksel Gezgin, Ahmet Oz, Shaymaa Al Sharqi, Zinar Pinar Gumus, and Nurhan Turgut Dunford. "Biological Activity of the Extracts from Pecan Shelling Industry Byproducts." Transactions of the ASABE 64, no. 3 (2021): 869–77. http://dx.doi.org/10.13031/trans.14439.
Повний текст джерелаАнотація:
HighlightsThe first study on characterization of the extracts obtained from industrial pecan nut processing byproducts.Chemical composition and biological activity of the extracts varied with type of byproduct and the pecan cultivars used in the process.Pecan shell extracts exhibited anticancer, antioxidant, and antimicrobial activity.Abstract. Industrial processing of pecan nuts produces large amounts of shells, which have economic significance for pecan growers and processors. Hence, it is imperative that valorization of pecan processing byproducts is explored. In this study, byproducts from commercial pecan shelling operations were evaluated as potential sources of biologically active phytochemicals. Shelling byproducts from Pawnee, Native, and Stuart cultivars were examined. Aqueous ethanol shell extracts were analyzed for their chemical composition using liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF/MS). Total phenolic content, DPPH radical scavenging capacity, anticancer activity, and antimicrobial activity of the samples were investigated. The chemical composition and biological activity of the shell extracts varied significantly with the pecan cultivar and type of byproduct stream used in the study. The presence of nut meat pieces in the byproducts resulted in high oil content in the extracts. The extract from Pawnee cultivar showed high DDPH activity, low IC50 for cancer cell lines, and high IC50 for the healthy cell line (Vero). Extracts from all cultivars had antimicrobial activity against Escherichia coli at relatively high disk loadings. This is the first study on the biological activity of extracts obtained from commercial pecan shelling byproducts. The findings of this study have significant practical implications and provide the initial data much needed for valorization of industrial pecan shelling byproducts. Keywords: Anticancer activity, Antimicrobial activity, Chemical composition, Pecan shell extract.
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Yang, Gongzheng, Qian Li, Kaixuan Ma, Cheng Hong, and Chengxin Wang. "The degradation mechanism of vanadium oxide-based aqueous zinc-ion batteries." Journal of Materials Chemistry A 8, no. 16 (2020): 8084–95. http://dx.doi.org/10.1039/d0ta00615g.
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Abou Mehrez, O., F. Masri, M. Baroudi, and F. Dossier-Berne. "Aqueous oxidation of acetaminophen with monochloramine." Water Supply 18, no. 5 (December 22, 2017): 1769–74. http://dx.doi.org/10.2166/ws.2017.242.
Повний текст джерелаАнотація:
Abstract The reactivity of the common pain reliever acetaminophen (paracetamol or 4-acetamidophenol) with monochloramine in aqueous solution was investigated in this study. Initially, monochloramine demands of acetaminophen (AAP) and its chlorination byproduct, 1,4-benzoquinone, were determined in excess of oxidant at pH 8.5 and 25 °C. Monochloramine demands of AAP and 1,4-benzoquinone were respectively 1.2 (±0.2) and 4.4 (±0.3) mol/mol after 72 h of reaction. Chlorination reactions were also conducted under the same experimental conditions in order to compare the oxidant demands and the reactivity of free chlorine and monochloramine toward AAP and 1,4-benzoquinone. Chlorine demands of AAP and 1,4-benzoquinone were much more important than monochloramine demands and respectively accounted for 13.4 (±0.2) and 6.8 (±0.5) mol/mol. The reaction of AAP with monochloramine was monitored using reversed-phase high performance liquid chromatography with ultraviolet absorbance (HPLC-UV). AAP reacted with monochloramine to form simultaneously two first byproducts. The half-life of reaction was estimated to be 90 min. The apparent second-order rate constant (kapp2) for the reaction of AAP with monochloramine at pH 8.5 was 231 M−1·h−1.
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Gu, Yexuan, Xuesong Zhang, Brian Deal, Lujia Han, Jilu Zheng, and Haoxi Ben. "Advances in energy systems for valorization of aqueous byproducts generated from hydrothermal processing of biomass and systems thinking." Green Chemistry 21, no. 10 (2019): 2518–43. http://dx.doi.org/10.1039/c8gc03611j.
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Liu, Tao, Xue Zhang, Zejun Peng, and Junfeng Zhao. "Water-removable ynamide coupling reagent for racemization-free syntheses of peptides, amides, and esters." Green Chemistry 23, no. 24 (2021): 9916–21. http://dx.doi.org/10.1039/d1gc03498g.
Повний текст джерелаАнотація:
A water-removable ynamide coupling reagent for racemization-free construction of amide and ester bonds was reported. No column chromatography purification was involved because acidic aqueous work-up removed the byproduct completely.
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Zhou, Hui, Hsin Wang, Frédéric A. Perras, Pranjali Naik, Marek Pruski, Aaron D. Sadow, and Igor I. Slowing. "Two-step conversion of Kraft lignin to nylon precursors under mild conditions." Green Chemistry 22, no. 14 (2020): 4676–82. http://dx.doi.org/10.1039/d0gc01220c.
Повний текст джерелаАнотація:
Treatment of Kraft lignin, massive byproduct of pulping industry, with dilute aqueous base followed by catalytic hydrogenation of the extracted monomers at ambient pressure yields KA oil, the precursor of high demand nylon polymer.
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Baruah, Shyamal, Alexander Fisyuk, Ivan V. Kulakov, and Amrit Puzari. "An Atom Economic Acid Catalyzed Synthetic Method for Aromatic Imines." Asian Journal of Chemistry and Pharmaceutical Sciences 2, no. 1 (April 17, 2017): 6. http://dx.doi.org/10.18311/ajcps/2017/10991.
Повний текст джерелаАнотація:
A new one-pot acid catalyzed synthetic methodology has been described for synthesis of aromatic imines. The reaction is carried out under microwave irradiation using minimum amount of methanol as solvent. Aqueous solution of the acid catalyst act as solvent for amine dissolution. The reaction yields substantial yield of product imine. The simplicity and environmentally benign nature of the process are the most notable features. The process can also be extended to include wide number of substrates. Product of the reaction can be isolated by simple procedure. The reaction can be carried out under mild conditions without heating to a higher temperature which eventually prevents the formation of nitrile byproducts in the reaction. Byproduct formation was significantly less during the reaction.
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Jusner, Paul, Markus Bacher, Hubert Hettegger, Huy Quang Lê, Antje Potthast, Herbert Sixta та Thomas Rosenau. "On the chemical interactions of the biomass processing agents γ-valerolactone (GVL) and N-methylmorpholine-N-oxide (NMMO)". Green Chemistry 23, № 16 (2021): 5832–48. http://dx.doi.org/10.1039/d1gc01777b.
Повний текст джерелаАнотація:
Biomass pretreatment with aqueous NMMO and digestion in GVL are common in biorefineries but their combination can lead to output loss, byproduct generation and uncontrollable reactions. The chemistry of the NMMO/GVL system is investigated in detail.
Дисертації з теми "Aqueous byproduct"
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Satoh, Andrea Yuki. "Aqueous remediation of a 4,4'-dichlorobiphenyl by Fenton's reagent a study of oxidative degradation, byproduct production, and toxicological effect /." Diss., Connect to online resource - MSU authorized users, 2008.
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Uvegi, Hugo Jake. "Aqueous reactivity of glassy industrial byproducts in alternative cementitious systems." Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/129037.
Повний текст джерелаАнотація:
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2020Cataloged from student-submitted PDF of thesis.
Includes bibliographical references (pages 177-203).
Alkali-activated, geopolymeric, and other novel binders offer an opportunity to curb the carbon footprint associated with ordinary Portland cement (OPC). CO₂ emissions inherent to source-material processing (i.e., firing of limestone at 1450 °C) and annual OPC production volumes of 4.1 billion metric tons cause an estimated 5-11% of global annual greenhouse gas (GHG) emissions. Material substitution with lower-footprint resources is therefore necessary for GHG impact mitigation. Glassy silica-, alumina-, lime-, and/or alkali-rich industrial byproducts (IBs) exhibit the properties necessary to achieve emissions reductions while preserving final product attributes expected of cementitious binders. Research and industry have both focused primarily on metakaolin and IBs such as blast furnace slag and coal fly ash as supplementary and alternative cementitious precursors.
Given projected limitations in such IB supply, it is imperative that we efficiently expand the materials search to other useful precursor candidates. This thesis focuses on chemical characterization and kinetic reactivity analysis of lesser-studied glassy materials through a combined experimental-computational approach, resulting in (1) physicochemical drivers for material aqueous reactivity and (2) a framework for evaluating new materials. First, I describe laboratory experiments involving reaction of a siliceous mixed-feedstock Indian biomass ash in aqueous sodium hydroxide solutions with selectively present lime and alumina sources. These experiments respectively yield tobermoritic calcium silicate hydrate products (Ca/Si ~~ 0.6-1) and semi-crystalline zeolite / geopolymer products (Si/Al ~~ 1); shown compositional ratios are known to be relevant to final material properties.
Through this work, I demonstrate a novel approach to calculating reaction product composition using spectroscopic solution analysis of dissolution / precipitation experiments. Subsequently, I describe computational efforts to mine literature-reported data for potential precursor materials. This results in a database of material compositional and physical property data represented by a SiO₂-Al₂O₃- CaO ternary diagram. Finally, I employ supervised and semi-supervised computational models, which confirm log-linear relationships between glass dissolution rates (i.e., log₁₀(rate)) and pH, inverse temperature (1/K), and glass connectivity (i.e. non-bridging oxygens per tetrahedron). While less interpretable, black-box models are observed to be more robust to the presence of additional features. Throughout the research program, reactivity is understood via material dissolution in aqueous solutions.
by Hugo Jake Uvegi.
Ph. D.
Ph.D. Massachusetts Institute of Technology, Department of Materials Science and Engineering
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Celhay, Clément. "Fractionnement de coproduits de pin maritime (Pinus pinaster) et de peuplier (Populus tremula) pour l'obtention d'extraits polyphénoliques à activité antioxydante : procédé d'extraction aqueuse en extracteur bi- vis et étude des conditions subcritiques." Thesis, Toulouse, INPT, 2013. http://www.theses.fr/2013INPT0015/document.
Повний текст джерелаАнотація:
Les voies de valorisation actuelles ne permettent pas d'absorber la totalité des coproduits de l'industrie du bois (noeuds, écorces, souches), qui sont des matières riches en composés bioactifs tels que les polyphénols, préférentiellement extraits par des solvants comme l'éthanol ou le méthanol. Le fractionnement aqueux à l'aide d'extracteur bi-vis permet d'obtenir des extraits polyphénoliques à activité antioxydante. Après avoir déterminé l'extractabilité des polyphénols de chaque matière en eau subcritique, les paramètres d'extraction en bi-vis ont été optimisés de façon à d'atteindre des conditions de température et de pression caractéristiques de l'eau subcritique. La présence d'un marqueur spécifique dans les extraits étaye l'hypothèse selon laquelle l'extracteur bi-vis permet d'atteindre les conditions de l'eau subcritique. Les effets des extraits sur la biodégradabilité de pots horticoles dans lesquels ils ont été incorporés ainsi que sur la croissance de plantes mises en culture dans ces pots ont été déterminés. La valorisation de l'extrudat comme matériau pour le thermopressage en panneaux de particules a également été étudiéeActual exploitation procedures can not absorb all the wood by-products (knots, barks, stumps), which are potent sources of bioactive compounds such as polyphenols, preferentially extracted by solvents such as ethanol or methanol. Aqueous fractionation has been performed with twin-screw extractors to obtain polyphenolic extracts with antioxidant activity. After having determined the extractability of polyphenols from each byproduct with subcritical water, the parameters of twin-screw extraction were optimized in order to reach temperature and pressure conditions in subcritical water area. The presence of a specific marker in the extracts supports the hypothesis that a twin-screw extractor allows to reach subcritical water conditions. The effects of the extracts on the biodegradability of horticultural pots in which the extracts have been incorporated and on the development of the plants grown in these pots have been evaluated. The valorisation of the extrudate as raw material for thermopressing particle boards has also been studied
Частини книг з теми "Aqueous byproduct"
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Balatti, A., and M. Cervellini. "The use of Industrial Byproducts as Carbon Sources or Growth Factors in the Manufacture of Aqueous Inoculants of Rhizobium and Bradyrhizobium." In Biological Nitrogen Fixation for the 21st Century, 657. Dordrecht: Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-011-5159-7_418.
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Taber, Douglass. "Best Synthetic Methods: Oxidation." In Organic Synthesis. Oxford University Press, 2011. http://dx.doi.org/10.1093/oso/9780199764549.003.0005.
Повний текст джерелаАнотація:
Although the enantioselective oxidation of alkyl aryl sulfides is well developed, much less is known about dialkyl sulfides. Tsutomu Katsuki of Kyushu University has designed (J. Am. Chem. Soc. 2007, 129, 8940) an Fe(salan) complex that combines with aqueous H2O2 to oxidize alkyl methyl sulfides in high ee. The oxidation of alcohols to aldehydes and ketones is one of the most widely practiced of synthetic transformations. Ge Wang of the University of Science and Technology in Beijing has developed (Chem. Lett. 2007, 36, 1236) a Mo catalyst that used aqueous H2O2 to effect this transformation. Secondary alcohols are oxidized more rapidly than primary alcohols. Vinod K. Singh of the Indian Institute of Technology, Kanpur, has found (Synth. Comm. 2007, 37, 4099) that the solid, inexpensive 6 can take the place of oxalyl chloride in the Swern oxidation. Viktor V. Zhdankin of the University of Minnesota, Duluth has devised (J. Org. Chem. 2007, 72, 8149) a polymer-bound hypervalent iodine reagent that is easily separated after use, and reoxidized for reuse. Enones such as 11 are versatile intermediates for organic synthesis. Makoto Tokunaga, now at Kyushu University, and Yasushi Tsuji, now at Kyoto University, have found (Tetrahedron Lett. 2007, 48, 6860) a Pd catalyst that, in the presence of O2 , will oxidize a cyclic ketone such as 10 to the enone. The direct oxidation of an alcohol to the acid is not always an efficient process, so the conversion of 12 to 13 would often be carried out over at least three steps. David Milstein of the Weizmann Institute of Science has devised (Science 2007, 317, 790) a Ru catalyst that effected the transformation in a single step, generating H2 as a byproduct as the oxidation proceeded. The oxidation of an aldehyde to the corresponding amide is also a useful transformation. Noritaka Mizuno of the University of Tokyo has designed (Angew. Chem. Int. Ed. 2007, 46, 5202) a Rh catalyst that can combine, in water, the aldehyde 14 and NH2OH to give the primary amide 15 . Johann Chan of Amgen Inc., Thousand Oaks, CA has found (J. Am. Chem. Soc. 2007, 129, 14106) a different Rh catalyst that mediated the oxidation of a sulfonamide to the nitrene, which under the reaction conditions inserted into the aldehyde H to give the amide 17.
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Li, Jie Jack, Chris Limberakis, and Derek A. Pflum. "Reductions." In Modern Organic Synthesis in the Laboratory. Oxford University Press, 2008. http://dx.doi.org/10.1093/oso/9780195187984.003.0010.
Повний текст джерелаАнотація:
The Barton deoxygenation (or Barton–McCombie deoxygenation) is a two-step reaction sequence for the reduction of an alcohol to an alkane. The alcohol is first converted to a methyl xanthate or thioimidazoyl carbamate. Then, the xanthate or thioimidazoyl carbamate is reduced with a tin hydride reagent under radical conditions to afford the alkane. Trialkylsilanes have also been used as the hydride source. Reviews: (a) McCombie, S. W. In Comprehensive Organic Synthesis; Trost, B. M.; Fleming, I., Eds.; Pergamon Press: Oxford, U. K., 1991; Vol. 8, Chapter 4.2: Reduction of Saturated Alcohols and Amines to Alkanes, pp. 818–824. (b) Crich, D.; Quintero, L. Chem. Rev. 1989, 89, 1413–1432. To a solution of the â-hydroxy-N-methyl-O-methylamide (0.272 g, 1.55 mol) in tetrahydrofuran (THF) (30 mL) were added carbon disulfide (6.75 mL, 112 mmol) and iodomethane (6.70 mL, 108 mmol) at 0 °C. The mixture was stirred at this temperature for 0.25 h, and then sodium hydride (60% suspension in mineral, 136.3 mg, 3.4 mmol) was added. After 20 min at 0 °C, the reaction was quenched by slow addition to 60 g of crushed ice. (Caution: hydrogen gas evolution!). The mixture was raised to room temperature and separated, and the aqueous layer was extracted with CH2Cl2 (4 × 15 mL). The combined organic extracts were dried (Na2SO4</aub>), concentrated in vacuo, and purified (SiO2, 5% EtOAc in hexanes) to afford 0.354 g (86%) of the xanthate. To a solution of the xanthate (2.95 g, 11.1 mmol) in toluene (100 mL) was added tributyltin hydride (15.2 mL, 56.6 mmol) and 2,2´-azobisisobutyronitrile (AIBN, 0.109 g, 0.664 mmol). The reaction mixture was then heated to reflux for 1 h. The mixture was cooled, concentrated in vacuo, and purified (SiO2, 100% hexanes to remove tin byproducts, followed by 10% EtOAc in hexanes to elute product) to afford 1.69 g (96%) of the N-methyl-O-methylamide.
Тези доповідей конференцій з теми "Aqueous byproduct"
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Hansen, Thomas E., Mena E. Tawfik, and F. J. Diez. "Application of the Electroosmotic Effect for Thrust Generation." In ASME 2014 4th Joint US-European Fluids Engineering Division Summer Meeting collocated with the ASME 2014 12th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/fedsm2014-22137.
Повний текст джерелаАнотація:
The present work focuses on demonstrating the capabilities of electro-osmotic pumps, EOPs, to generate thrust. EOPs have high power to volume ratio and operate on ionic aqueous solutions making them a good candidate for use as thrusters in miniature watercraft such as micro underwater gliders. Millimeter-size nano-porous membrane will be used to achieve milli-Newton thrust. Electro-osmotic pumps are operated under high electric fields to achieve highest thrust possible. A byproduct of high electric fields in EOPs is the generation of gas which is addressed by using bipolar rectangular wave pumping. This resulted in over 55% increase in flow rate when compared to DC pumping for the same average voltage while reducing gas generation. When properly sized and optimized for thrust, the feasibility of EOPs is demonstrated. This is the first experimental application of a membrane-based electro-osmotic pump for propulsion. Several membranes of different materials were tested including polymer and ceramic membranes. It was found that glass micro-capillary arrays are the most suitable membranes for electro-osmotic thrusters, or EOTs. Among their advantages include their rigid construction and ability to produce high flow rates.
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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.
Повний текст джерелаАнотація:
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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Samarkin, Yevgeniy, Murtada Saleh Aljawad, Abduljamiu Olalekan Amao, Theis Ivan Sølling, Khalid Al-Ramadan, Murtadha J. AlTammar, and Khalid M. Alruwaili. "Improving Long-Term Hydraulic Fracture Conductivity in Carbonate Formations by Substitution of Harder Minerals." In Abu Dhabi International Petroleum Exhibition & Conference. SPE, 2021. http://dx.doi.org/10.2118/208118-ms.
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Abstract Hydraulic fracturing is applied in tight formations to create conductive paths within the reservoir. However, the conductivity of the created fractures declines with time due to the closure stresses. The decline is sharp in soft formations because of proppant embedment and fracture surface asperities failure. The improvement in fracture surface hardness can mitigate the abovementioned challenges and sustain the fracture conductivity. This research targeted enhancing carbonate rock's hardness by forming minerals harder than calcite. Carbonate rocks, namely dolomite, limestone, and chalk, were treated at ambient temperature conditions by immersion into the aqueous solutions of NaF and ZnSO4 with a concentration of 0.1M. During treatment, the solution was sampled to monitor the changes in ion concentration and estimate the reaction kinetics by ICP - OES and IC devices. The hardness of rock samples was measured by impulse hammering technique before and after the treatment. The changes in rock's mineralogy and elemental content were studied by XRD and SEM imaging. The permeability of rocks was estimated by the steady-state gas injection method. The formation of smithsonite (ZnCO3, Mohs scale hardness - 4.5) and fluorite (CaF2, Mohs scale hardness - 4) was achieved in the reaction of calcite (CaCO3, Mohs scale hardness – 3) with ZnSO4 and NaF, respectively. Chalk and limestone reacted efficiently with both solutions; however, the dolomite reaction with solutions was feeble. XRD detected the newly formed smithsonite minerals, and it was observed in SEM images that minerals formed an interconnected net in chalk and limestone specimens. In dolomite samples, the minerals formed isolated gatherings that were sparsely located on the grains. The treatments caused the improvement of the rock specimen's hardness. 0.1M solution of NaF was not effective in strengthening the rock samples (only chalk sample experienced 6.7% improvement in hardness) because of low concentration of the solutions used; however, treatment resulted in negligible changes in permeability of the samples. In contrast, Young's modulus of limestone and chalk treated by ZnSO4 increased by 17% and 21%. Permeability of rocks treated by ZnSO4 reduced drastically, most likely due to the formation of gypsum as a byproduct of the reaction. This research presents a method for carbonate rock hardening via the transformation of parent calcite into harder minerals. It explains its possible application in the petroleum industry to sustain the conductivity of propped/acid fractures. The proposed technique will help to mitigate fracture conductivity decline due to proppant embedment and asperities failure issues that are especially severe in soft formations.
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Bernal, Ivan, Hector Guido, Spencer Rautus, and Joseph Piacenza. "Toward an Experimental Design Approach for Magnetocaloric Refrigeration Systems." In ASME 2016 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/detc2016-60161.
Повний текст джерелаАнотація:
The magnetocaloric effect (MCE) is a magneto-thermodynamic phenomenon that heats and cools specific alloys through exposure to an alternating magnetic field. This phenomenon has the potential to create a temperature difference in a heat carrier mimicking a conventional vapor compression refrigeration cycle without harmful chemical byproducts. This research investigates the design of an experimental testing mechanism for identifying key interactions between design variables, while maximize temperature differential Key noise parameters (KNP). Fluid flow rate, magnetic field exposure time, and variations in heat exchanger configuration are explored. Understanding the significant interactions between these variables will lead to the design of a functional prototype that serves as a basis for future development in applications of the MCE for large-scale cooling systems. In this work, elemental gadolinium is used due to its high magnetic entropy change, and consequently high reversible temperature change when exposed to a magnetic field. An aqueous propylene glycol solution serves as the heat carrier based on its high heat capacity and basic pH level, reducing the possibility of degradation within the magnetocaloric material. The magnetic field is supplied by a grade N52 magnet with a magnetic field strength of approximately 0.9 Tesla. Based on this analysis, a concept stage design for experimentally maximizing the impact of the magnetocaloric effect is presented.
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Ye, Fang, Hang Guo, and Chongfang Ma. "Two-Phase Flow in Anode Serpentine Flow Field of a Direct Methanol Fuel Cell." In 2010 14th International Heat Transfer Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/ihtc14-23130.
Повний текст джерелаАнотація:
Fuel Cells have attracted much attention. Liquid fed direct methanol fuel cells (DMFCs), which have many important advantages over such as the easy storage and refilling of the aqueous methanol solution, are considered to be good choices for small mobile devices. Water and carbon dioxide are the sole fuel oxidized byproducts. The anode side of liquid fed DMFC is a two-phase system primarily consisting of methanol solution and carbon dioxide bubbles. In this paper, a transparent direct methanol fuel cell was designed and fabricated for investigations of two-phase flow characteristics in anode serpentine flow field. In situ observations of the carbon dioxide bubbles and two-phase flow patterns inside the flow field were made. The effects of cell current, methanol solution flow rate and methanol solution mole concentration on the flow patterns and cell performance were studied, respectively. Experimental results indicate that the electrochemical reaction and two-phase flow characteristics interacted each other. The mean size of CO2 bubbles and the gas void fraction increased with increase in current density. The typical flow patterns are bubbly flow and slug flow. At the upside down U type location of the serpentine channel, long slug bubbles easily formed and blocked the channel. The gas void fraction decreased with increase in methanol solution flow rate. The methanol solution mole concentration influences the two-phase flow slightly.