Letteratura scientifica selezionata sul tema "Redox economy"
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Articoli di riviste sul tema "Redox economy":
1
Burns, Noah Z, Phil S Baran e Reinhard W Hoffmann. "Redox Economy in Organic Synthesis". Angewandte Chemie International Edition 48, n. 16 (17 marzo 2009): 2854–67. http://dx.doi.org/10.1002/anie.200806086.
2
Kotha, Sambasivarao, Deepti Goyal e Arjun S. Chavan. "Diversity-Oriented Approaches to Unusual α-Amino Acids and Peptides: Step Economy, Atom Economy, Redox Economy, and Beyond". Journal of Organic Chemistry 78, n. 24 (26 novembre 2013): 12288–313. http://dx.doi.org/10.1021/jo4020722.
3
Kotha, Sambasivarao, Deepti Goyal e Arjun S. Chavan. "ChemInform Abstract: Diversity-Oriented Approaches to Unusual α-Amino Acids and Peptides: Step Economy, Atom Economy, Redox Economy, and Beyond". ChemInform 45, n. 12 (6 marzo 2014): no. http://dx.doi.org/10.1002/chin.201412239.
4
Guo, Sheng-Qiang, Hui-Qing Yang, Ai-Lian Wang, Yu-Zhen Jiang, Guo-Qiang Xu, Yong-Chun Luo, Zhao-Xu Chen e Peng-Fei Xu. "Divergent Ritter-type amination via photoredox catalytic four-component radical-polar crossover reactions". Green Chemistry 23, n. 23 (2021): 9571–76. http://dx.doi.org/10.1039/d1gc03048e.
5
Giovannitti, Alexander. "Redox-Active Polymers Designed for the Circular Economy of Energy Storage Devices". ECS Meeting Abstracts MA2023-02, n. 4 (22 dicembre 2023): 505. http://dx.doi.org/10.1149/ma2023-024505mtgabs.
Abstract (sommario):
The decarbonization of the transport and energy sector will accelerate the demand for electrochemical energy storage devices. While past and current research efforts strongly focused on improving the performance of cells (energy density, power density, and stability), little attention has been paid to how these devices are recycled after their end of life, leaving the recycling of devices as an afterthought. Thus, to limit the accumulation of electric waste and the depletion of important raw materials for energy storage devices, there is an urgency to develop a circular economy for materials and integrate recyclability in device architectures. In my talk, I will present a new concept where we applied chemical design strategies to intentionally develop redox-active materials for a circular economy.[1] We developed solution-processible redox-active conjugated polymers that function as binder- and additive-free electrodes with high stability in aqueous electrolytes, achieving >98% retention of the capacity after 500 charging/discharging cycles. The tuning of the local environment of the polymer further enables fast charging of micron-thick single-phase electrodes with cell voltages > 1.2 V in aqueous electrolytes. Finally, we demonstrate the recyclability of the devices, achieving >85% capacity retention after recycling (76 % retention after recycling the device twice). Our work is a demonstration of how material chemistry enables the development of a circular economy for electrochemical energy storage devices. [1] S. T. M. Tan, T. J. Quill, M. Moser, G. LeCroy, X. Chen, Y. Wu, C. J. Takacs, A. Salleo, A. Giovannitti, ACS Energy Lett. 2021, 6, 3450.
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Guo, Sheng-Qiang, Hui-Qing Yang, Yu-Zhen Jiang, Ai-Lian Wang, Guo-Qiang Xu, Yong-Chun Luo, Zhao-Xu Chen, Haixue Zheng e Peng-Fei Xu. "Organophotoredox catalytic four-component radical-polar crossover cascade reactions for the stereoselective synthesis of β-amido sulfones". Green Chemistry 24, n. 8 (2022): 3120–24. http://dx.doi.org/10.1039/d2gc00224h.
Abstract (sommario):
Organophotoredox catalytic four-component radical-polar crossover cascade reactions for the stereoselective synthesis of β-amido sulfones with high atom-, step-, and redox economy and excellent diastereoselectivity.
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Liu, Jia, Shuo Li, Raf Dewil, Maarten Vanierschot, Jan Baeyens e Yimin Deng. "Water Splitting by MnOx/Na2CO3 Reversible Redox Reactions". Sustainability 14, n. 13 (22 giugno 2022): 7597. http://dx.doi.org/10.3390/su14137597.
Abstract (sommario):
Thermal water splitting by redox reactants could contribute to a hydrogen-based energy economy. The authors previously assessed and classified these thermo-chemical water splitting redox reactions. The Mn3O4/MnO/NaMnO2 multi-step redox cycles were demonstrated to have high potential. The present research experimentally investigated the MnOx/Na2CO3 redox water splitting system both in an electric furnace and in a concentrated solar furnace at 775 and 825 °C, respectively, using 10 to 250 g of redox reactants. The characteristics of all reactants were determined by particle size distribution, porosity, XRD and SEM. With milled particle and grain sizes below 1 µm, the reactants offer a large surface area for the heterogeneous gas/solid reaction. Up to 10 complete cycles (oxidation/reduction) were assessed in the electric furnace. After 10 cycles, an equilibrium yield appeared to be reached. The milled Mn3O4/Na2CO3 cycle showed an efficiency of 78% at 825 °C. After 10 redox cycles, the efficiency was still close to 60%. At 775 °C, the milled MnO/Na2CO3 cycles showed an 80% conversion during cycle 1, which decreased to 77% after cycle 10. Other reactant compounds achieved a significantly lower conversion yield. In the solar furnace, the highest conversion (>95%) was obtained with the Mn3O4/Na2CO3 system at 775 °C. A final assessment of the process economics revealed that at least 30 to 40 cycles would be needed to produce H2 at the price of 4 €/kg H2. To meet competitive prices below 2 €/kg H2, over 80 cycles should be achieved. The experimental and economic results stress the importance of improving the reverse cycles of the redox system.
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Becker, René, Saeed Amirjalayer, Ping Li, Sander Woutersen e Joost N. H. Reek. "An iron-iron hydrogenase mimic with appended electron reservoir for efficient proton reduction in aqueous media". Science Advances 2, n. 1 (gennaio 2016): e1501014. http://dx.doi.org/10.1126/sciadv.1501014.
Abstract (sommario):
The transition from a fossil-based economy to a hydrogen-based economy requires cheap and abundant, yet stable and efficient, hydrogen production catalysts. Nature shows the potential of iron-based catalysts such as the iron-iron hydrogenase (H2ase) enzyme, which catalyzes hydrogen evolution at rates similar to platinum with low overpotential. However, existing synthetic H2ase mimics generally suffer from low efficiency and oxygen sensitivity and generally operate in organic solvents. We report on a synthetic H2ase mimic that contains a redox-active phosphole ligand as an electron reservoir, a feature that is also crucial for the working of the natural enzyme. Using a combination of (spectro)electrochemistry and time-resolved infrared spectroscopy, we elucidate the unique redox behavior of the catalyst. We find that the electron reservoir actively partakes in the reduction of protons and that its electron-rich redox states are stabilized through ligand protonation. In dilute sulfuric acid, the catalyst has a turnover frequency of 7.0 × 104s−1at an overpotential of 0.66 V. This catalyst is tolerant to the presence of oxygen, thereby paving the way for a new generation of synthetic H2ase mimics that combine the benefits of the enzyme with synthetic versatility and improved stability.
9
Wu, Dezhen, Jialu Li, Libo Yao, Rongxuan Xie e Zhenmeng Peng. "An Electrochemical Ethylamine/Acetonitrile Redox Method for Ambient Hydrogen Storage". ECS Meeting Abstracts MA2022-01, n. 1 (7 luglio 2022): 136. http://dx.doi.org/10.1149/ma2022-011136mtgabs.
Abstract (sommario):
Hydrogen is an appealing energy carrier that can potentially replace conventional fossil fuels in the development of a clean, sustainable hydrogen economy, which would resolve environmental problems caused by the combustion of the non-renewable resources while also meeting the rising demand for energy. However, hydrogen storage has remained a major roadblock in the hydrogen economy development. As a matter of fact, the state-of-the-art methods fall short of the 2025 Department of Energy (DOE) onboard hydrogen storage target of 5.5 wt.% under 85 °C and 12 bars. Herein we report a new, electrochemical ethylamine/acetonitrile redox method for efficient, high-capacity hydrogen storage under completely ambient conditions. The amine/nitrile redox couple is selected due to their moderate chemical polarity and relatively simple hydrogenation and dehydrogenation pathways, which would aid reaction activation and reduce the energy barrier. Electrochemical potential provides the driving force in CH3CH2NH2 dehydrogenation under ambient conditions, rather than high temperature and pressure that are typically required to thermally drive an endothermic process. We demonstrate an effective, complete cycle of CH3CN hydrogenation to CH3CH2NH2 for hydrogen uptake and CH3CH2NH2 dehydrogenation to CH3CN for hydrogen release at low overpotentials, using commercial Pt black catalyst in an electrochemical cell. The studied CH3CH2NH2/CH3CN system has a theoretical H2 storage capacity of 8.9 wt.%, well surpassing the 5.5 wt.% DOE target. This study offers a new, effective hydrogen storage strategy that can be extended to many other amine/nitrile redox systems and would help advance the hydrogen economy development.
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Zhang, Hao-Yuan, Tong-Tong Zeng, Zhen-Biao Xie, Ying-Ying Dong, Cha Ma, Shan-Shan Gong e Qi Sun. "Aerial Oxygen-Driven Selenocyclization of O-Vinylanilides Mediated by Coupled Fe3+/Fe2+ and I2/I− Redox Cycles". Molecules 27, n. 21 (31 ottobre 2022): 7386. http://dx.doi.org/10.3390/molecules27217386.
Abstract (sommario):
In the past decade, selenocyclization has been extensively exploited for the preparation of a wide range of selenylated heterocycles with versatile activities. Previously, selenium electrophile-based and FeCl3-promoted methods were employed for the synthesis of selenylated benzoxazines. However, these methods are limited by starting material availability and low atomic economy, respectively. Inspired by the recent catalytic selenocyclization approaches based on distinctive pathways, we rationally constructed an efficient and greener double-redox catalytic system for the access to diverse selenylated benzoxazines. The coupling of I2/I− and Fe3+/Fe2+ catalytic redox cycles enables aerial O2 to act as the driving force to promote the selenocyclization. Control and test redox experiments confirmed the roles of each component in the catalytic system, and a PhSeI-based pathway is proposed for the selenocyclization process.
Tesi sul tema "Redox economy":
1
Shao, Na. "Development of eco-compatible transformations and their synthetic applications". Electronic Thesis or Diss., Aix-Marseille, 2022. http://www.theses.fr/2022AIXM0305.
Abstract (sommario):
Les fragments de polycétides sont omniprésents dans une large gamme de médicaments et de produits naturels conférant une excellente bioactivité à ces molécules organiques. En conséquence, les chimistes organiciens doivent développer de nouvelles stratégies remplissant les principes d’éco-compatibilité pour construire ces échafaudages d’intérêts. Dans cette thèse, nous avons récemment développé différentes cascades éco-compatibles évitant les étapes inutiles pour accéder aux fragments de polycétides et à des analogues fluorés. Nous avons d'abord réalisé une cascade multi-catalytique impliquant une fluorination-aldolization décarboxylante suivie d’un dédoublement cinétique générant des 1,3-diols énantiopurs présentant un stéréocentre fluoré tétrasubstitué difficile d’accès. Nous avons ensuite combiné une réaction de type aldol-Tishchenko avec un dédoublement cinétique organocatalysé pour produire un large éventail de 1,3-diols fluorés avec trois stéréocentres contigus et d'excellentes énantiosélectivités. Afin d’obtenir des économies d’étapes redox, nous avons également développé une aldolisation redox-neutre d'alcool favorisée par une base directement à partir du niveau d'oxydation de l'alcool pour donner une série d'anti 1,3-diols difluorés. Enfin, nous avons conçu une stratégie économique concise pour donner le motif polycétide clé de l'apratoxine A, un produit naturel avec des niveaux élevés d'activité cytotoxique. Cette séquence en seulement 6 étapes est bien plus rapide que les précédentes nécessitant de 12 à 20 étapesPolyketides fragments are ubiquitous in a wide range of drugs and natural products conferring excellent bioactivity to these organic molecules. As a consequence, organic chemists must develop novel strategies fulfilling at the best the different concepts of synthetic economies to construct such valuable scaffolds. During this PhD, we developed different eco-compatible cascades avoiding unnecessary steps to access different polyketides fragments and fluorinated analogues. At first, we developed a multi-catalytic enantioselective fluorination-decarboxylative aldolization followed by a kinetic resolution to generate enantiopure 1,3-diols featuring challenging tetrasubstituted fluorinated stereocenters. Subsequently, we realized the synthesis of a complementary type of fluorinated structure by combining an aldol-Tishchenko reaction with a Kinetic Resolution, producing a wide array of fluorinated 1,3-diols possessing three contiguous stereocenters with excellent levels of enantiocontrol. These reactions provide concise routes to useful 1,3-diols but consume stoichiometric reagents to induce change in the oxidation state from the starting materials to the final products. In order to obtain better redox-economies, we also developed a base-promoted redox-neutral alcohol-aldolization starting from the alcohol oxidation level to directly afford a series of difluorinated anti 1,3-diols. Finally, we designed a concise and redox-economical 6-step strategy providing a key polyketide fragment of apratoxin A, a natural product showing high levels of cytotoxic activity. This route is much shorter than the previously reported 12-20 steps sequences required to access this scaffold
2
Barbosa, Guilherme Valentim. "Análise de bolhas imobiliárias ao redor do mundo". reponame:Repositório Institucional do FGV, 2018. http://hdl.handle.net/10438/24764.
Abstract (sommario):
Submitted by Guilherme Valentim Barbosa (guilhermevalentim@gmail.com) on 2018-09-18T02:06:09Z
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Este trabalho busca analisar empiricamente a existência de bolhas imobiliárias ao redor do mundo e identificar quando esses comportamentos explosivos no preço dos imóveis ocorreram. Os resultados foram obtidos por meio de uma metodologia recursiva de testes de raiz unitária, os testes SADF e GSADF propostos por Phillips e co-autores. Foram coletados dados de preços de imóveis para 28 países e seus respectivos índices de preços ao consumidor. Os resultados obtidos apontaram a existência de comportamentos explosivos em aproximadamente 90% das séries analisadas.
This study aims to empirically analyze the existence of real estate bubbles around the world and to identify when these explosive behavior in real estate prices occurred. The results were obtained through a recursive methodology of unit root tests, the SADF and GSADF tests proposed by Phillips and co-authors. Real estate price data were collected for 28 countries and their respective consumer price indexes. The results obtained indicate the existence of explosive behavior in about 90% of the analyzed series.
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XXX, AZHARUDDIN. "Solar fuels via two-step thermochemical redox cycle for power and fuel production". Doctoral thesis, Politecnico di Torino, 2019. http://hdl.handle.net/11583/2744933.
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Sönmez, Hatice Gülsah [Verfasser], George [Akademischer Betreuer] Tsatsaronis, George [Gutachter] Tsatsaronis e Klaus [Gutachter] Görner. "Techno-economic evaluation of a liquid redox process employing amino acid salts for sour natural gas treatment / Hatice Gülsah Sönmez ; Gutachter: George Tsatsaronis, Klaus Görner ; Betreuer: George Tsatsaronis". Berlin : Technische Universität Berlin, 2017. http://d-nb.info/115618567X/34.
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Burgenmeister, Simeon Benedikt [Verfasser], Ingo [Akademischer Betreuer] Krossing e Sebastian [Akademischer Betreuer] Hasenstab-Riedel. "Investigations of ionic liquids based on chloroiodates, bromostannates, and chloromanganates: towards their application in redox flow batteries : : economic evalutation of battery design concepts an ddevelopment of a battery test software". Freiburg : Universität, 2017. http://d-nb.info/1162443235/34.
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Henriques, Felipe Abad. "Estudo do comportamento do retorno das ações ao redor da data ex-distribuição de capital no mercado acionário brasileiro". reponame:Repositório Institucional do FGV, 2011. http://hdl.handle.net/10438/9771.
Abstract (sommario):
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This study aims to evaluate the behavior of the stock return around exdistribution of capital days in the Brazilian stock market. Using the event study methodology we found evidences of an abnormal return around the event. It was found that the abnormal return persists among the period from 2000 to 2010. Additionally, we verify that for the Brazilian market it is not possible to assign the effect of taxes the cause of the abnormal results.
Este estudo procura avaliar o comportamento do retorno das ações ao redor das datas ex-distribuição de capital no mercado acionário brasileiro. A partir da metodologia de estudo de eventos encontramos indícios da existência de um retorno anormal médio ao redor do evento. Constatou-se que o retorno anormal persiste do longo do período de 2000 até o fim de 2010. Adicionalmente verificamos que no caso brasileiro não é possível atribuir ao efeito dos impostos a presença do retorno anormal verificado.
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Lundin, Rasmus, e Benjamin Beitler-Dorch. "Modelling and Analysis of Mobile Energy Transmission for Offshore Wind Power : An analysis of flow batteries as an energy transmission system for offshore wind power". Thesis, Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-40082.
Abstract (sommario):
A comparison between a traditional fixed high voltage direct current energy transmission system and a mobile transmission system utilizing vanadium redox flow batteries has been conducted in this degree work. The purpose of this comparison was to evaluate if a mobile energy transmission system could be competitive in terms of energy efficiency and cost-effectiveness for use in offshore wind power applications. A literary study was made to fully grasp the various technologies and to create empirical ground of which cost estimation methods and energy calculations could be derived. A specific scenario was designed to compare the two transmission systems with the same conditions. To perform the comparison, a model was designed and simulated in MATLAB. The results from the model showed that the flow battery system fell behind in energy efficiency with a total energy loss of 33.3 % compared to the 11.7 % of the traditional system, future efficiency estimations landed it at a more competitive 17.5 %. The techno-economic results proved that a mobile flow battery system would be up to nine times more expensive in comparison to a traditional transmission system, with the best-case scenario resulting in it being roughly two times more expensive. The main cause of this was found out to be the expensive energy subsystem, specifically the electrolyte, used in the flow battery system. Several environmental risks arise when using a flow battery system with this electrolyte as well which could harm marine life severely. In conclusion; with further development and cost reductions, a case could be made for the advantages of a truly mobile energy transmission system. Specifically, in terms of the pure flexibility and mobility of the system, allowing it to circumvent certain complications. The mobility of the system gives the possibility of selling energy where the spot prices are at their highest, providing a higher revenue potential compared to a traditional fixed system. As for now though, it is simply too expensive to be a viable solution.
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"Techno-Economic Analysis of a Concentrating Solar Power Plant Using Reduction/Oxidation Metal Oxides for Thermochemical Energy Storage". Master's thesis, 2017. http://hdl.handle.net/2286/R.I.45523.
Abstract (sommario):
abstract: Concentrating Solar Power (CSP) plant technology can produce reliable and dispatchable electric power from an intermittent solar resource. Recent advances in thermochemical energy storage (TCES) can offer further improvements to increase off-sun operating hours, improve system efficiency, and the reduce cost of delivered electricity. This work describes a 111.7 MWe CSP plant with TCES using a mixed ionic-electronic conducting metal oxide, CAM28, as both the heat transfer and thermal energy storage media. Turbine inlet temperatures reach 1200 °C in the combined cycle power block. A techno-economic model of the CSP system is developed to evaluate design considerations to meet targets for low-cost and renewable power with 6-14 hours of dispatchable storage for off-sun power generation. Hourly solar insolation data is used for Barstow, California, USA. Baseline design parameters include a 6-hour storage capacity and a 1.8 solar multiple. Sensitivity analyses are performed to evaluate the effect of engineering parameters on total installed cost, generation capacity, and levelized cost of electricity (LCOE). Calculated results indicate a full-scale 111.7 MWe system at $274 million in installed cost can generate 507 GWh per year at a levelized cost of $0.071 per kWh. Expected improvements to design, performance, and costs illustrate options to reduce energy costs to less than $0.06 per kWh.Dissertation/Thesis
Masters Thesis Civil, Environmental and Sustainable Engineering 2017
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Fares, Robert Leo. "A dynamic model-based estimate of the potential value of a vanadium redox flow battery for energy arbitrage and frequency regulation in Texas". Thesis, 2012. http://hdl.handle.net/2152/ETD-UT-2012-08-6271.
Abstract (sommario):
Large-scale electrochemical energy storage is a technology that is uniquely suited to integrate intermittent renewable energy sources with the electric grid on a large scale. Grid-based energy storage also has the potential to reduce costs associated with periods of peak electric demand. For these reasons, this work describes the potential applications for grid-based energy storage, and then reviews large-scale energy storage technology innovations since the development of the lead-acid battery. The potential value of grid-based battery energy storage is discussed in the context of restructured electricity markets; then, a dynamic model-based economic optimization routine is developed to gauge the potential value of a vanadium redox flow battery (VRFB) operating for wholesale energy arbitrage and frequency regulation in Texas. Based on this analysis, the relative value of a VRFB in various regions of Texas for energy arbitrage and frequency regulation is examined. It is shown that frequency regulation is an appealing application for a grid-based VRFB, with a VRFB utilized for frequency regulation service in Texas potentially worth approximately $1500/kW. Finally, the effect of a VRFB’s characteristics on its value for frequency regulation and energy arbitrage are compared, and the operational insight developed in this work is used to glean how policies to integrate a large-scale energy storage with the electricity market might be crafted.text
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Bistrika, Alexander A. "Degradation of graphite electrodes in acidic bromine electrolytes". Thesis, 2013. http://hdl.handle.net/1957/37935.
Abstract (sommario):
As the world's power needs grow, the demand for power from renewable resources, such as wind or solar is increasing. One major drawback associated with these renewable resources is that the power output is dependent on environmental factors, such as cloud cover and wind speeds. This allows the possibility of either power output exceeding or falling short of forecast levels that may lead to grid instabilities. Therefore, Large Scale Energy Storage (LSES) systems are critical to store excess power when the output exceeds demand in order to supplement output power when it falls short of demand.¹ The Zinc/Bromine Redox Flow Battery (RFB) is a promising technology because of previously reported long cycle-life (CL) capability, high efficiencies, low cost materials, and scalable operating conditions.² The excellent energy storage performance of the Zinc/Bromine system was confirmed by measuring both Faradaic and Coulombic electrochemical cell efficiency dependence on temperature of a bench scale Zinc/Bromine flow cell. At room temperature, near 75% Faradaic efficiency was measured when cycling the system between 20% and 100% State of Charge (SOC), which is in good agreement with published values,³ and was measured to be over 80% efficient when operating at an elevated temperature of 50°C.
To elucidate capital and operational costs, key system operation parameters especially focused on degradation mechanisms were investigated. Since deep discharge cycling is perceived as highly damaging to electrochemical systems, a system was cycled between 0% and 5% (SOC) 10,000 times. Performance was quantified by measuring the frequency factor (i[subscript 0]) and relative activation energy (α) for the reactions using Tafel scans. No statistically significant degradation or change to the electrodes was observed during the zero point cycling experiment. However, it was found that under conventional operation damage to the electrodes does accumulate, presumably due to the highly oxidative environment caused by the presence of high concentrations of dissolved bromine or tri-bromide. While the performance of both electrodes shows decreases in frequency factor attributed to the damage process, the bromide oxidation process seems to be more damaging (i.e., at the positive electrode during the charging process). Long term measurements show a degradation of the electrocatalytic parameters at an applied overpotential of 100 mV from ca. 40 mA/cm² to ca. 5 mA/cm² at the positive electrode and from ca. 20 mA/cm² to ca. 10 mA/cm² for the negative electrode. A degradation rate model was proposed to predict the service life expectancy of graphite electrodes in a bromine system based on processes showing a combined second order reaction rate coupled with a negative first order reaction rate. The model can be used to predict the cost of energy when operating any device using graphite electrodes, based on the operating power ratio, defined here as the quotient between operating power and system rated power. This damage could be partially reversed by exposing the electrode surfaces to concentrated potassium hydroxide dissolved in isopropanol, presumably due to exfoliation of the electrocatalytic surface leading to the exposure of a clean surface with electrocatalytic performance close to the original. Further, a chemical pretreatment for the graphite surface imparting enhanced stability in aqueous bromine systems was developed that shows negligible damage when similar amounts of current have passed through the electrode surface. After bromide oxidation equivalent to passing ca. 10 Ah/cm² the treated surface showed a change in steady state current density at an applied overpotential of 100 mV from ca. 50 mA/cm² to ca. 48 mA/cm².Graduation date: 2013
Access restricted to the OSU Community at author's request from April 1, 2013 - April 1, 2015
Libri sul tema "Redox economy":
1
Wanjala, Bernadette. Sources of economic growth in Kenya: A redux. Nairobi, Kenya: Kenya Institute for Public Policy Research and Analysis, 2007.
2
Wanjala, Bernadette. Sources of economic growth in Kenya: A redux. Nairobi, Kenya: Kenya Institute for Public Policy Research and Analysis, 2007.
3
Wanjala, Bernadette. Sources of economic growth in Kenya: A redux. Nairobi, Kenya: Kenya Institute for Public Policy Research and Analysis, 2007.
4
Dan, Dimancescu, e Costescu Manuel, a cura di. Romania redux: A view from Harvard. București: Humanitas, 2004.
5
Hughes, Jonathan. The governmental habit redux: Economic controls from colonial times to the present. 2a ed. Princeton, N.J: Princeton University Press, 1991.
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Hughes, Jonathan R. T. The governmental habit redux: Economic controls from colonial times to the present. Princeton, N.J: Princeton University Press, 1991.
7
Svensson, Lars E. O. Optimal policy with partial information in a forward-looking model: Certainty-equivalence redux. Cambridge, Mass: National Bureau of Economic Research, 2003.
8
Garr, Doug. IBM redux: Lou Gerstner and the business turnaround of the decade. New York: HarperBusiness, 2000.
9
Garr, Doug. IBM redux: Lou Gerstner and the business turnaround of the decade. New York: HarperBusiness, 1999.
10
Abdelmalek, Ali Aït. L' Europe communautaire, l'Etat-nation et la société rurale: Essai de sociologie des médiations institutionnelles et organisationnelles (l'exemple du Pays de Redon). Paris: L'Harmattan, 1996.
Capitoli di libri sul tema "Redox economy":
1
Gutmann, Peter M. "The Subterranean Economy, Redux". In The Economics of the Shadow Economy, 2–18. Berlin, Heidelberg: Springer Berlin Heidelberg, 1985. http://dx.doi.org/10.1007/978-3-642-88408-5_1.
2
Abegaz, Berhanu. "Comparative Economics Redux". In Understanding Economic Transitions, 281–85. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-21584-1_11.
3
Rogozen-Soltar, Mikaela. "Back to the Mediterranean? Return migration, economic crisis, and contested values in Southern Spain". In The Mediterranean Redux, 102–19. London: Routledge, 2022. http://dx.doi.org/10.4324/9781003268666-6.
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Bonaldo, Cinzia, e Nicola Poli. "Vanadium Redox Flow Batteries: Characteristics and Economic Value". In Lecture Notes in Networks and Systems, 1721–31. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-06825-6_166.
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Pingali, Prabhu. "Are the Lessons from the Green Revolution Relevant for Agricultural Growth and Food Security in the Twenty-First Century?" In Emerging-Economy State and International Policy Studies, 21–32. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-5542-6_2.
Abstract (sommario):
AbstractThe Green Revolution had profound positive impacts on human welfare and economic development across the developing world. However, its global reach was limited by agroclimatic, infrastructural, social, and political constraints. Regional disparities in poverty reduction, intra-societal inequities, and gender differences in the distribution of benefits persist even in countries that witnessed positive Green Revolution outcomes. This essay synthesizes the lessons learned and the policy redirections needed for a ‘redux’ version of the Green Revolution that enhances food and nutrition security and economic development while minimizing social, environmental, and health tradeoffs.
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Mathur, Ryan, e Yun Zhao. "Copper Isotopes Used in Mineral Exploration". In Isotopes in Economic Geology, Metallogenesis and Exploration, 433–50. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-27897-6_14.
Abstract (sommario):
AbstractThe use of copper isotopes related to ore deposit location and genesis has greatly expanded over the past twenty years. The isotope values in ores, rocks, soils, and water range greater than 10‰ and provide ample isotopic variation to identify and interpret complex geological process. From an exploration standpoint, the copper isotope values in waters, sulfides and weathered rocks vector to mineralization at depth. Ground and surface waters display the greatest potential for both green and brownfields exploration, whereas Fe-oxides and other related ore minerals isotope compositions for exploration are nascent. From an ore genesis perspective, the copper isotopes serve as a redox proxy to aid in unraveling magmatic and hydrothermal processes related to metal sulfide precipitation. In summary, the use of copper isotopic approaches by the mining industry are ideal as they point to processes directly related to the metal of economic interest and should be employed in all stages of the mine life from exploration to extraction, and to environmental monitoring post-mining activities.
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Norman, Marc D. "The 187Re-187Os and 190Pt-186Os Radiogenic Isotope Systems: Techniques and Applications to Metallogenic Systems". In Isotopes in Economic Geology, Metallogenesis and Exploration, 89–122. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-27897-6_4.
Abstract (sommario):
AbstractRhenium, Os, and Pt are redox sensitive elements that are concentrated in highly reducing environments such as those associated with black shales but mobile under more oxidizing conditions such as those associated with arc volcanism. They are chalcophile in many terrestrial ore-forming environments, and their isotopic systematics provide unique opportunities to date the formation of sulfide ore deposits and understand their petrogenesis. Fractional crystallization of magmatic sulfide ores generates primary variations in Re/Os and Pt/Os that allow mineral and whole rock isochron ages to be determined and discrimination of crustal and mantle sources based on initial Os isotopic compositions. Molybdenite is especially well suited for geochronology due to its high Re/Os and resistance to resetting. Rhenium concentrations in molybdenite tend to reflect the composition or provenance of the ore-forming fluids, with higher concentrations associated with more primitive sources or more oxidized fluids and lower concentrations with more evolved and/or reduced conditions, although local and regional factors also have a significant influence. Many studies have used pyrite for dating but its typically low Re concentration, variable initial Os isotopic composition (reflecting fluid mxing), and susceptibility to re-equilibration makes its use as a geochronometer problematic in many cases. Other sulfide minerals such as bornite and arsenopyrite have shown promise for Re–Os isotope geochronology but additional studies are needed to evaluate their broader applicability for dating of ore deposits. The isobaric beta decay of parent isotope 187Re to 187Os has restricted investigation of this system by microbeam techniques such as ion microprobe or laser ablation mass spectrometry, especially for geochronology. This requires either chemically processing the sample to separate the elements or novel techniques such as collision-cells that preferentially ionize the Re and Os during the analysis. Thermal ionization mass spectrometry (TIMS) and inductively-coupled plasma mass spectrometry (ICPMS) are the most widely applied techniques for Re-Pt-Os isotopic analyses. Specialized techniques for sample digestion to ensure redox equilibrium between Os in the sample and the isotopically enriched spikes used for isotope dilution measurements are typically required. This chapter briefly reviews development of the 187Re-187Os and 190Pt-186Os isotopic systems for earth science, physico-chemical controls on their behavior in ore-forming environments, and applications to metallogenic systems.
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Abbas, Jaffar, Khalid Al-Sulaiti, Daniel Balsalobre Lorente, Syed Ale Raza Shah e Umer Shahzad. "Reset the Industry Redux through Corporate Social Responsibility". In Economic Growth and Environmental Quality in a Post-Pandemic World, 177–201. London: Routledge, 2023. http://dx.doi.org/10.4324/9781003336563-9.
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Huston, David L., Robert B. Trumbull, Georges Beaudoin e Trevor Ireland. "Light Stable Isotopes (H, B, C, O and S) in Ore Studies—Methods, Theory, Applications and Uncertainties". In Isotopes in Economic Geology, Metallogenesis and Exploration, 209–44. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-27897-6_8.
Abstract (sommario):
AbstractVariations in the abundances of light stable isotopes, particularly those of hydrogen, boron, carbon, oxygen and sulfur, were essential in developing mineralization models. The data provide constraints on sources of hydrothermal fluids, carbon, boron and sulfur, track interaction of these fluids with the rocks at both the deposit and district scales, and establish processes of ore deposition. In providing such constraints, isotopic data have been integral in developing genetic models for porphyry-epithermal, volcanic-hosted massive sulfide, orogenic gold, sediment-hosted base metal and banded-iron formation-hosted iron ore systems, as discussed here and in other chapters in this book. After providing conventions, definitions and standards used to present stable isotope data, this chapter summarizes analytical methods, both bulk and in situ, discusses processes that fractionate stable isotopes, documents the isotopic characteristics of major fluid and rock reservoirs, and then shows how stable isotope data have been used to better understand ore-forming processes and to provide vectors to ore. Analytical procedures, initially developed in the 1940s for carbon–oxygen analysis of bulk samples of carbonate minerals, have developed so that, for most stable isotopic systems, spots as small as a few tens of μm are routinely analyzed. This precision provides the paragenetic and spatial resolution necessary to answer previously unresolvable genetic questions (and create new questions). Stable isotope fractionation reflects geological and geochemical processes important in ore formation, including: (1) phase changes such as boiling, (2) water–rock interaction, (3) cooling, (4) fluid mixing, (5) devolatilization, and (6) redox reactions, including SO2 disproportionation caused by the cooling of magmatic-hydrothermal fluids and photolytic dissociation in the atmosphere. These processes commonly produce gradients in isotopic data, both in time and in space. These gradients, commonly mappable in space, provide not only evidence of process but also exploration vectors. Stable isotope data can be used to estimate the conditions of alteration or mineralization when data for coexisting minerals are available. These estimates use experimentally- or theoretically-determined fractionation equations to estimate temperatures of mineral formation. If the temperature is known from isotopic or other data (e.g., fluid inclusion data or chemical geothermometers), the isotopic composition of the hydrothermal fluid components can be estimated. If fluid inclusion homogenization and compositional data exist, the pressure and depth of mineralization can be estimated. One of the most common uses of stable isotope data has been to determine, or more correctly delimit, fluid and sulfur sources. Estimates of the isotopic compositions of hydrothermal fluids, in most cases, do not define unequivocal sources, but, rather, eliminate sources. As an example, the field of magmatic fluids largely overlap that of metamorphic fluids in δ18O-δD space, but are significantly different to the fields of meteoric waters and seawater. As such, a meteoric or seawater origin for a fluid source may be resolvable, but a magmatic source cannot be resolved from a metamorphic source. Similarly, although δ34S ~ 0‰ is consistent with a magmatic-hydrothermal sulfur source, the signature can also be produced by leaching of an igneous source. Recent analytical and conceptual advances have enabled gathering of new types of isotopic data and application of these data to resolve new problems in mineral deposit genesis and geosciences in general. Recent developments such as rapid isotopic analysis of geological materials or clumped isotopes will continue to increase the utility of stable isotope data in mineral deposit genesis and metallogeny, and, importantly, for mineral exploration.
10
Quesnel, Benoît, Christophe Scheffer e Georges Beaudoin. "The Light Stable Isotope (Hydrogen, Boron, Carbon, Nitrogen, Oxygen, Silicon, Sulfur) Composition of Orogenic Gold Deposits". In Isotopes in Economic Geology, Metallogenesis and Exploration, 283–328. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-27897-6_10.
Abstract (sommario):
AbstractOrogenic gold deposits formed in various terranes of most ages since the Paleoarchean and generally consist of quartz veins hosted in shear zones formed at the ductile brittle transition under greenschist to lower amphibolite metamorphic conditions. Vein mineralogy is dominated by quartz with various amounts of silicates, carbonates, phyllosilicates, borates, tungstates, sulfides, and oxides. The isotopic composition of these minerals and fluid inclusions has been investigated since the 1960s to constrain the characteristics of orogenic fluid systems involved in the formation of gold deposits worldwide. This review is based on 8580 stable isotope analyses, including δ18O, δD, δ13C, δ34S δ15N, δ11B, and δ30Si values, from 5478 samples from 558 orogenic gold deposits reported in the literature from 1960 to 2010. This contribution describes the variability of the light stable isotopic systems as function of the minerals, the age of the deposits, their regional setting, and their country rocks. The temperature of isotopic equilibrium of orogenic gold veins is estimated from mineral pairs for oxygen and sulfur isotopes. Based on these temperatures, and on fractionation between mineral and fluid components (H2O, CO2 and H2S), the isotopic composition of fluids is estimated to better constrain the main parameters shared by most of auriferous orogenic fluid systems. Orogenic gold deposits display similar isotopic features through time, suggesting that fluid conditions and sources leading to the formation of orogenic gold deposits did not change significantly from the Archean to the Cenozoic. No consistent secular variations of mineral isotope composition for oxygen (−8.1‰ ≤ δ18O ≤ 33‰, n = 4011), hydrogen (−187‰ ≤ δD ≤ −4‰, n = 246), carbon (−26.7‰ ≤ δ13C ≤ 12.3‰, n = 1179), boron (−21.6‰ ≤ δ11B ≤ 9‰, n = 119), and silicon (−0.5‰ ≤ δ30Si ≤ 0.8‰, n = 33) are documented. Only nitrogen (1.6‰ ≤ δ15N ≤ 23.7‰, n = 258) and sulfide sulfur from deposits hosted in sedimentary rocks (−27.2‰ ≤ δ34S ≤ 25‰, n = 717) display secular variations. For nitrogen, the change in composition is interpreted to record the variation of δ15N values of sediments devolatilized during metamorphism. For sulfur, secular variations reflect incorporation of local sedimentary sulfur of ultimate seawater origin. No significant variation of temperature of vein formation is documented for orogenic gold deposits of different ages. Quartz-silicate, quartz-carbonate and sulfide-sulfide mineral pairs display consistent temperatures of 360 ± 76 °C (1σ; n = 332), in agreement with the more common greenschist facies hostrocks and fluid inclusion microthermometry. Fluid sources for orogenic gold deposits are complex but the isotopic systems (hydrogen, boron, carbon, nitrogen, oxygen, sulfur) are most consistent with contributions from metamorphic fluids released by devolatilization of igneous, volcano-sedimentary and/or sedimentary rocks. The contribution of magmatic water exsolved from magma during crystallization is not a necessary component, even if permissible in specific cases. Isotopic data arrays can be interpreted as the result of fluid mixing between a high T (~550 °C)—high δ18O (~10‰)—low δD (~−60‰) deep-seated (metamorphic) fluid reservoir and a low T (~200 °C)—low δ18O (~2‰)—high δD (~0‰) upper crustal fluid reservoir in a number of orogenic gold deposits. The origin of the upper crustal fluid is most likely sea- or meteoric water filling the host rock porosity, with a long history of water–rock isotope exchange. Mixing of deep-seated and upper crustal fluids also explains the large variation of tourmaline δ11B values from orogenic gold veins. Regional spatial variations of oxygen and hydrogen isotope compositions of deep-seated fluid reservoirs are documented between orogenic gold districts. This is the case for the Val-d’Or (Abitibi), Coolgardie and Kalgoorlie (Yilgarn) where the oxygen isotope composition of the deep-seated fluid end-member is 4‰ lower compared to that from the Timmins, Larder Lake, and Kirkland Lake districts (Abitibi). However, both mixing trends converge towards a common, low δ18O upper crustal fluid end-member. Such variations cannot be related to fluid buffering at the site of deposition and suggest provinciality of the fluid source. The contribution of meteoric water is mainly recorded by fluid inclusions from Mesozoic and Cenozoic age deposits, but micas are not systematically in isotopic equilibrium with fluid inclusions trapped in quartz from the same vein. This suggests late involvement of meteoric water unrelated to deposit formation. Yet, a number of deposits with low δD mica may record infiltration of meteoric water in orogenic gold deposits. Isotope exchange between mineralizing fluid and country rocks is documented for oxygen, carbon, sulfur and silicon isotopes. Large variations (> 10‰) of sulfide δ34S values at the deposit scale are likely related to evolving redox conditions of the mineralizing fluid during reaction with country rocks. Deposits hosted in sedimentary rocks show a shift to higher δ18O values as a result of fluid/rock oxygen exchange with the regional sedimentary country rocks.
Atti di convegni sul tema "Redox economy":
1
Brendelberger, Stefan, Jan Felinks, Dominik Kolb e Christian Sattler. "Particle Conveyer for Solar Thermo-Chemical Processes and Related Solid Heat Recovery Systems". In ASME 2016 10th International Conference on Energy Sustainability collocated with the ASME 2016 Power Conference and the ASME 2016 14th International Conference on Fuel Cell Science, Engineering and Technology. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/es2016-59577.
Abstract (sommario):
On the way to a de-carbonized economy by 2050 new technologies have to be developed and deployed into the market. In solar driven thermochemical processes concentrated solar radiation is used as a renewable high temperature heat source to drive a chemical reaction. These processes are promising pathways for the production of gaseous and liquid fuels and therefore they can provide sustainable chemical energy carriers with inherent long-term storage capabilities. Amongst these processes, redox cycles for the production of syngas from water and carbon dioxide received considerable interest due to their high theoretical process efficiencies. In these processes a redox material is reduced using high temperature heat which is provided by concentrated solar radiation. In a second reaction, at considerably lower temperatures, the redox material is oxidized while splitting water or carbon dioxide. One requirement for the design of efficient redox processes is a high recovery rate of the sensible heat of the solid redox material. In recent redox process concepts the use of inert heat transfer particles in combination with a particulate redox material has been proposed. Amongst other benefits this methodology allows to recover heat from the redox material. A corresponding solid-solid heat recovery system is under development. In a single stage the heat recovery unit acts as a co-current heat exchanger. By combining several units and by using a proper flow path a quasi-counter-current heat exchanger can be obtained. Such a heat recovery system requires that particles are lifted at temperatures well above 1100°C. These high temperatures require a simple design, decent thermal insulation and the thermal shielding of all moving parts and engine. The present work is dealing with the development of a respective conveying system which can be operated at the targeted temperatures, while heat losses are prevented as far as possible. A lab scale version of the conveyer is constructed and tested. A numerical model of the conveyer is developed and validated using results of an experimental campaign with particles at 1150°C. The next step in the assessment of the conveyer system is the analysis of the performance of a scale up version. A generic process analysis will be conducted to obtain operational and design requirements of the scale up conveyer. A detailed scale up version is developed accordingly and the validated numerical model is applied to this design to predict the heat losses during the particle lifting and to discuss their impact on the total process performance.
2
Kareem, M. O., H. K. Amusa e E. M. Nashef. "Evaluation of the Ionic Liquid, 1-Butyl-1-Methylpyrrolidinium Bis(Trifluoromethylsulfonyl)imide, as a Sustainable Material for Modern Energy Devices". In SPE Nigeria Annual International Conference and Exhibition. SPE, 2023. http://dx.doi.org/10.2118/217220-ms.
Abstract (sommario):
Abstract Sustainable materials are those which satisfy the three sustainability criteria of being environmentally safe, profitable, and acceptable to society. Within a circular economy such material's societal acceptability is linked to the wider and long-term implications of its production and its durable usability, along with the assurance that it does not leave negative environmental footprints. 1-butyl-1-methyl pyrrolidinium bis(trifluoromethylsulfonyl)imide (abbreviated as BMPI) is an ionic liquid (IL), with minimal negative environmental impacts that is applied in different components of energy devices like batteries. Like other ionic liquids (ILs) it is non-volatile and non-flammable. It is additionally non-toxic and not too viscous within practical operating conditions, making it safe and suitable for use in batteries. Such batteries constitute crucial parts of renewable energy systems where they are useful for energy storage, thus enabling a practical alternative for diversifying from fossil energy sources. ILs like BMPI, comprising only ions while being in a liquid state, show superior conductivity and dielectric properties relevant for metal-ion batteries, redox-flow batteries, and even solid-state batteries. The performance of BMPI, as well as the economic viability of its utilization, is assessed by analyzing its performance in different battery systems, including "membraneless" systems, wherein it constitutes an active part of components such as capacitors, electrolytes, and ion-exchange membranes. A focused analysis of its usability and potential acceptability in the energy industry of Nigeria among others in Europe, the Middle East, and Africa (EMEA) is further presented, providing a holistic evaluation of the potential sustainability of BMPI and similar ionic liquids as components of energy devices in a circular economy.
3
Cook, Korey, Ethan Lau, Jordan Thayer, Shane Mann, Tom Guarr e Andre Benard. "Development of a Membraneless Organic Redox Flow Battery". In ASME 2018 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/imece2018-88024.
Abstract (sommario):
The development of a novel electrochemical energy storage system, specifically a redox flow batteries (RFB), is discussed in this work. It has the distinction of not requiring an ion-selective membrane due to novel chemical compounds. The techno-economic aspects of a low-cost 3D printed flow cell and system design tailored for a novel chemistry is discussed. The organic compounds employed are inexpensive, have a long lifespan, and as mentioned enable the system to be membraneless. All these substantially decrease the capital and maintenance costs. Suitable systems were developed and tested using chemically compatible 3D printed materials for the flow cells. The estimated cost per kWh is lower than the Department of Energy’s target cost of $150/kWh for grid storage capacity. A commercial scale system, rated for a 1 MW, 5-hour discharge time, has an estimated cost of $65/kWh. The proposed technology could revolutionize the energy storage industry and help with the construction of a more stable and efficient energy grid.
4
Adebayo, A. I., P. Zamani-Dehkordi, H. Zareipour e A. M. Knight. "Economic viability of price arbitrage operation of vanadium redox battey in Alberta's energy market". In 12th IET International Conference on AC and DC Power Transmission (ACDC 2016). Institution of Engineering and Technology, 2016. http://dx.doi.org/10.1049/cp.2016.0476.
5
Bektay, Yerkin, Gaukhar Turysbekova, Akmurat Altynbek, Bauyrzhan Shiderin e Baurzhan Duysebaev. "INVESTIGATION OF THE DISTRIBUTION OF ASSOCIATED METALS IN PRODUCTIVE WELLS FOR IN SITU RECOVERY (ISR) OF URANIUM". In 22nd SGEM International Multidisciplinary Scientific GeoConference 2022. STEF92 Technology, 2022. http://dx.doi.org/10.5593/sgem2022v/4.2/s18.09.
Abstract (sommario):
Uranium in situ recovery (ISR) is an effective method for extracting uranium from sandstone deposits. Many uranium deposits are characterized by the presence of associated metals: gold, platinum group metals and rare earth metals. For one of the uranium deposits in Kazakhstan, studies were carried out on sampling from productive wells at the ISR of uranium. An analysis was carried out for the content of uranium, rare earth elements, scandium, germanium, yttrium and other metals. For the study, samples were taken from productive wells used for uranium ISL. Studies have shown the presence of valuable associated metals in almost all productive wells where samples were taken. The analysis showed the possibility of extracting associated metals from productive solutions. It is noted that a higher effect can be achieved on mothballed wells when using leaching solutions with a higher redox potential. This will make it possible to obtain an additional economic effect from suspended (closed) wells, the number of which is over 70% of the total number of wells drilled in this field.
6
Haltiwanger, Julia F., Jane H. Davidson e Elizabeth J. Wilson. "Renewable Hydrogen From the Zn/ZnO Solar Thermochemical Cycle: A Cost and Policy Analysis". In ASME 2010 4th International Conference on Energy Sustainability. ASMEDC, 2010. http://dx.doi.org/10.1115/es2010-90196.
Abstract (sommario):
Flexible energy carriers are a crucial element of our energy portfolio. In a future in which a significant fraction of our energy comes from renewable sources, renewably produced fuels will be vital. The zinc/zinc-oxide thermochemical redox cycle is one approach for producing hydrogen using solar energy. This paper explores the level of carbon taxation necessary to make the cycle competitive with hydrogen production via methane reforming. In addition, the time frame for economic viability is assessed through the use of experience curves under minimal input, mid-range, and aggressive incentive policy scenarios. Prior work projects that hydrogen produced by the zinc/zinc-oxide cycle will cost between $5.02 and $14.75/kg, compared to $2.40 to $3.60/kg for steam methane reforming. Overcoming this cost difference would require a carbon tax of $119 to $987/tCO2, which is significantly higher than is likely to be implemented in most countries. For the technology to become cost competitive, incentive policies that lead to early implementation of solar hydrogen plants will be necessary to allow the experience effect to draw down the price. Under such policies, a learning curve analysis suggests that hydrogen produced via the Zn/ZnO cycle could become economically viable between 2032 and 2069, depending on how aggressively the policies encourage the emerging technology. Thus, the Zn/ZnO cycle has the potential to be economically viable by mid-century if incentive policies—such as direct financial support, purchase guarantees, low interest rate loans, and tax breaks—are used to support initial projects.
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Ferreira da Rocha e Silva, Ana Beatriz, e Paulo de Oliveira Reis Filho. "PROJETO REVIVER CENTRO E A TRANSFORMAÇÃO URBANA DO CENTRO DO RIO DE JANEIRO". In Seminario Internacional de Investigación en Urbanismo. Universitat Politècnica de Catalunya, Grup de Recerca en Urbanisme, 2022. http://dx.doi.org/10.5821/siiu.12160.
Abstract (sommario):
With the closure of non-essential commercial activities, suspension of in-person events and restriction of the movement of people (and of capital) due to the SARS-Covid 19 epidemic, several cities around the globe saw the collapse of their economies. And in the central region of Rio de Janeiro city it was no different: the process of recent urban re-signification, which had already been suffering the effects of the political-economic crises since 2014, was significantly worsened by the current health crisis. Thus, the Reviver Centro project emerges as a new proposal for the transformation of the central region – focusing on the Castelo and Cinelândia areas, where the effects of the epidemic restrictive measures were more evident in social and economic terms. Amongst its guidelines, the project predicts the urban recovery of the area via a new legislation, which allows the transformation of commercial buildings into residential use – therefore encouraging the renewal of uses and spaces in the city centre. Based on studies on urban transformation processes in the region, implemented or not, since the 2000s, it is intended to explore in this work how and/or if the guidelines of the Reviver Centro urban project would respond to the 21st century city aspirations, in its essence creative, inclusive, diverse, sustainable. Keywords: city, image, identity, urban policies Com o fechamento das atividades comerciais não-essenciais, suspensão de eventos presenciais e restrição de circulação de pessoas (e de capital) em função da epidemia de SARS-Covid 19, diversas cidades ao redor do mundo sofreram o colapso de suas economias. E na região central da cidade do Rio de Janeiro não foi diferente: o processo de ressignificação urbana recente, que já vinha sentindo os efeitos das crises político-econômicas desde 2014, foi significativamente agravado pela crise sanitária atual. Assim, o projeto Reviver Centro surge como uma nova proposta para transformação da região central – com foco nas áreas do Castelo e Cinelândia, onde os efeitos das medidas restritivas da epidemia foram mais evidentes em termos sociais e econômicos. Dentre suas diretrizes, o projeto prevê a recuperação urbana desta área se valendo de uma nova legislação, que permite a transformação de edifícios comerciais em uso residencial – incentivando, com isso, a renovação de usos e dos espaços no centro da cidade. Tendo como base estudos sobre os processos de transformação urbana na região, implementados ou não, desde os anos 2000, pretende-se explorar neste trabalho como e/ou se as principais diretrizes do projeto urbano Reviver Centro responderiam aos anseios da cidade do século XXI, em sua essência criativa, inclusiva, diversa, sustentável. Palavras-chave: cidade, imagem, identidade, políticas públicas urbanas.
8
Kintner-Meyer, Michael C. W., Tony B. Nguyen, Chunlian Jin, Patrick J. Balducci, Marcelo A. Elizondo, Vilayanur V. Viswanathan, Yu Zhang e Whitney G. Colella. "Evaluating the Competitiveness of Energy Storage for Mitigating the Stochastic, Variable Attributes of Renewables on the Grid". In ASME 2012 6th International Conference on Energy Sustainability collocated with the ASME 2012 10th International Conference on Fuel Cell Science, Engineering and Technology. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/es2012-91482.
Abstract (sommario):
Energy storage has recently attracted significant interest as an enabling technology for integrating stochastic, variable renewable power into the electric grid. To meet the renewable portfolio standards targets imposed by 29 U.S. states and the District of Columbia, electricity production from wind technology has increased significantly. At the same time, wind turbines, like many renewables, produce power in a manner that is stochastic, variable, and non-dispatchable. These attributes introduce challenges to generation scheduling and the provision of ancillary services. To study the impacts of the stochastic variability of wind on regional grid operation and the role that energy storage could play to mitigate these impacts, Pacific Northwest National Laboratory (PNNL) has developed a series of linked, complex techno-economic-environmental models to address two key questions: A) What are the future expanded balancing requirements necessary to accommodate enhanced wind turbine capacity, so as to meet the renewable portfolio standards in 2020? Specific analyses are conducted for the four North American Electric Reliability Corporation (NERC) western subregions. B) What are the most cost-effective technological solutions for providing either fast ramping generation or energy storage to serve these balancing requirements? PNNL applied a stochastic approach to assess the future, expanded balancing requirements for the four western subregions with high wind penetration in 2020. The estimated balancing requirements are quantified for four subregions: Arizona-New Mexico-Southern Nevada (AZ-NM-SNV), California-Mexico (CA-MX), Northwest Power Pool (NWPP), and Rocky Mountain Power Pool (RMPP). Model results indicate that the new balancing requirements will span a spectrum of frequencies, from minute-to-minute variability (intra-hour balancing) to those indicating cycles over several hours (inter-hour balancing). The sharp ramp rates in the intra-hour balancing are of significant concern to grid operators. Consequently, this study focuses on analyzing the intra-hour balancing needs. A detailed, life-cycle cost (LCC) modeling effort was used to assess the cost competitiveness of different technologies to address the future intra-hour balancing requirements. Technological solutions considered include combustion turbines, sodium sulfur (NaS) batteries, lithium ion (Li-ion) batteries, pumped-hydro energy storage (PHES), compressed air energy storage (CAES), flywheels, redox flow batteries, and demand response (DR). Hybrid concepts were also evaluated. For each technology, distinct power and energy capacity requirements are estimated. LCC results for the sole application of intra-hour balancing indicate that the most cost competitive technologies include Na-S batteries, flywheels, and Li-ion assuming future cost reductions. Demand response using smart charging strategies was found to also be cost-competitive with natural gas combustion turbines. This finding is consistent among the four subregions and is generally applicable to other regions.
9
Manokaran, Padmanaban, Fahad Al Rumaithi, Mohamad Bara Adi e Saeed Khalfan Al Suwaidi. "Effective Front-End Loading Management - Most Occurred Flaws in FEL Execution". In ADIPEC. SPE, 2022. http://dx.doi.org/10.2118/210881-ms.
Abstract (sommario):
Abstract Project Management team aims to strive for 100% success all the time. it's no secret that sometimes projects fail due to various reasons. But a project failure doesn't have to be the end of the story. Project failures can often offer valuable lessons for future project planning. Given the magnitude of investment observed in an Upstream Projects, it is necessary to adopt appropriate methods and processes to ensure the economic viability of the projects, as well as to effectively control the fulfilment of scope, schedule, quality and risk mitigation. The oil and gas industry has consistently used the combination of both methodologies of the PMI and IPA in the development of major projects, with particular attention on the front-end loading methodology (FEL), which combines an approach of so-called "rolling wave planning", with a vision of technical and cost integration in the light of other Project execution techniques. Certainly, most of Capital projects had fulfilled all the mandatory Front-End Loading (FEL) requirements set by an organization. However, at sanction gate only very few projects are allowed to proceed for execution, and rest are directed to redo or retrofit the FEL's. This Paper aims to capture the most occurred flaws in FEL execution of Upstream Oil & Gas Projects as below: Over Design & Gold PlatingIncomplete Technology SelectionPoor definition of Brownfield Works & Lack of Interface ManagementUnderstating Infrastructure RequirementsLow Stakeholder EngagementUnresolved Risks & UncertaintiesEstimating ErrorsOverly Optimistic Economics In addition, it also presents recommendations to improve the FEL execution and minimize the potential design changes during Project execution. It can be seen clearly all the above issues are often occurring in most of the Capital projects during FEL execution. These findings can be viewed as a lesson learned approach for all Oil & Gas Upstream capital Projects. This will guide Owners Project Management team better understanding of FEL issues at upfront while developing new projects or executing the FEL phase within budget, on schedule with desired quality.
10
Barros, Natalia Nakamura, e Giovanna Tomczinski Novellini Brígitte. "Diagnóstico de interface BIM na matriz curricular do curso de Arquitetura e Urbanismo da Facens". In IV ENCONTRO NACIONAL SOBRE O ENSINO DE BIM. ANTAC, 2022. http://dx.doi.org/10.46421/enebim.v4i00.1904.
Abstract (sommario):
BIM pode ser entendido como um conjunto inter-relacionado de processos, políticas e tecnologias que gerenciam a informação em todo o ciclo de vida da edificação (SUCCAR, 2009). Com a publicação de decretos e de normas que visam a incentivar e regulamentar o uso de BIM na construção civil, as universidades perceberam a urgência na implementação de BIM nas suas respectivas grades curriculares a fim de capacitarem os futuros profissionais conforme as necessidades do mercado de trabalho. Frente a isso, o Ministério da Economia em conjunto com a Associação Nacional de Tecnologia do Ambiente Construído – ANTAC, estão coordenando a rede de Células BIM, cujo objetivo é criar instrumentos pedagógicos para a difusão do BIM no ambiente acadêmico. O Centro Universitário Facens, que visa a formar profissionais capacitados conforme as tendências atuais do mercado, é uma das instituições que formam este grupo. O curso de Arquitetura e Urbanismo do Centro Universitário Facens é um curso que desde o seu início se preocupa com o uso da tecnologia tanto na grade curricular das disciplinas, quanto durante a ministração das aulas, a partir de metodologias ativas. O presente relatório tem como objetivo demonstrar os resultados do diagnóstico BIM na matriz curricular do curso de Arquitetura e Urbanismo do Centro Universitário Facens, através do mapeamento do potencial de interface com BIM em todos os componentes curriculares do curso.
O método utilizado para o diagnóstico da matriz curricular foi desenvolvido por Checucci (2014), adaptado e apresentado nas reuniões de Células BIM. O processo ocorreu a partir de análise documental e categorial de cada componente curricular do curso, avaliados e classificados de acordo com 8 categorias relacionadas ao BIM. Os resultados foram identificados em caixas individuais que representam cada uma das disciplinas, que no conjunto formam a matriz. Cada caixa de análise possui o nome da disciplina no centro e ao redor, as 8 categorias, além da carga horária da disciplina na primeira linha. Os procedimentos utilizados foram: i. Classificação dos componentes curriculares conforme a Resolução nº 1, de 26 de março de 2021 do MEC (MEC, 2021); ii. Relação entre o componente curricular e BIM; iii. Avaliação da interface dos usos do modelo BIM com as disciplinas (Categoria B); iv. Análise da interface das competências BIM de domínio técnico ou de execução nas disciplinas (Categoria C); v. Análise da interface dos estágios da implementação BIM nas disciplinas (Categoria D); vi. Potencial de integração da disciplina (Categoria E); vii. Identificação da interface quanto às etapas do ciclo de vida da edificação (Categoria F); viii. Classificação da disciplina conforme a área de formação (Categoria G); ix. Verificação da possibilidade do trabalho/discussão de BIM na disciplina (Categoria H).
Os resultados do diagnóstico BIM na matriz curricular do curso de Arquitetura e Urbanismo do Centro Universitário Facens demonstrou que 67% das disciplinas do curso possuem clara interface com BIM, 22% possível interface e apenas 11% das disciplinas não possuem interface com BIM. Na análise geral das categorias, constatou-se que o modelo BIM pode ser utilizado principalmente na visualização, seguido de parametrização e orientação a objetos (Categoria B). O uso prático do modelo (Categoria C) não acontece em todas as disciplinas. A modelagem, colaboração e integração (Categoria D) são possíveis de se trabalhar na maioria das disciplinas. A integração com disciplinas/alunos do mesmo semestre (Categoria E) ocorre com maior frequência, entretanto entre diferentes cursos ou outros semestres a possibilidade de integração é menor. Na Categoria F, a maior interface ocorre na etapa de projetação, não havendo nenhuma na etapa de planejamento da construção, e reduzidas interfaces na construção, uso e fim-de-vida. O modelo BIM é trabalhado de maneira mais prática (Categoria H) nas disciplinas, sendo também trabalhado os conceitos em algumas destas. Foi possível verificar uma clara interface principalmente nas disciplinas de projeto de arquitetura e urbanismo, projeto de urbanismo, projeto de paisagismo, projeto de conservação e restauro, design de interiores e trabalho final de graduação; nestas houve uma clara interface na grande maioria das categorias. As disciplinas de desenho digital e arquitetura digital são voltadas principalmente ao ensino tanto conceitual quanto prático de BIM, nestas a maioria das subcategorias de BIM também são de clara interface. As disciplinas de sistemas estruturais, conforto e teoria e história também foram classificadas como de clara interface, sendo possível o uso de BIM para visualização, manipulação do modelo, colaboração e simulação. O mapeamento do potencial de interface com BIM em todos os componentes curriculares do curso de Arquitetura e Urbanismo da Facens é uma etapa importante compreender as potenciais aplicações BIM nas disciplinas. Como ações futuras, espera-se planejar e executar ações a fim de implementar os resultados apresentados neste relatório.