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The Electrochemical Oxidation of H2 and CO at Patterned Ni Anodes of SOFCs

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Book Series: Schriften des Instituts für Werkstoffe der Elektrotechnik, Karlsruher Institut für Technologie / Institut für Werkstoffe der Elektrotechnik ISSN: 18681603 ISBN: 9783866446861 Year: Volume: 20 Pages: XI, 144 p. DOI: 10.5445/KSP/1000023286 Language: ENGLISH
Publisher: KIT Scientific Publishing
Subject: Technology (General)
Added to DOAB on : 2019-07-30 20:01:58
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In this work, a deeper understanding of the electrochemical oxidation at SOFC anodes was gained by the experimental characterization of patterned Ni anodes in H2-H2O and CO-CO2 atmosphere. By high resolution data analysis, the Line Specific Resistance attributed to charge transfer and its dependencies on gas composition, temperature and polarization voltage were identified. Furthermore, the comparison of the performance of patterned and cermet anodes was enabled using a transmission line model.

Catalytic soot oxidation by platinum on sintered metal filters. Influence of the platinum quantity, particle size and location, and investigation of the platinum-soot contact

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ISBN: 9783866441033 Year: Pages: VII, 135 p. DOI: 10.5445/KSP/1000005906 Language: ENGLISH
Publisher: KIT Scientific Publishing
Subject: Chemical Engineering
Added to DOAB on : 2019-07-30 20:02:00
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The great challenge for next years concerning the emission of diesel engines is to develop diesel particle filters (DPF) with catalytic regeneration systems. This work is focused on the global understanding of the diesel soot oxidation on sintered metal filters (SMF). Platinum is studied as reference catalyst. The first objective is to determine which of platinum quantity, platinum particle size, or platinum location exhibits the preponderant influence on the catalytic.

Die partielle Oxidation von Propan zu Acrylsäure. Bestimmung der Reaktionskinetik und in-situ Charakterisierung des Katalysators unter Betriebsbedingungen

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ISBN: 3937300171 Year: Pages: 140 p. DOI: 10.5445/KSP/1000001260 Language: GERMAN
Publisher: KIT Scientific Publishing
Subject: Chemical Engineering
Added to DOAB on : 2019-07-30 20:01:59

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Gegenstand der vorliegenden Arbeit ist die partielle einstufige Oxidation von Propan zu Acrylsäure an einem oxidischen Multikomponentenkatalysator mit der Zusammensetzung Mo1V0,33Nb0,17Te0,25Ox. In der vorliegenden Arbeit stehen zwei Gesichtspunkte im Mittelpunkt: grundlegende Untersuchungen zur Reaktionskinetik und die in-situ Charakterisierung des Katalysators unter Betriebsbedingungen mittels Festkörperelektrolypotentiometrie.Die Reaktion sollte mit Hilfe eines möglichst einfachen Reaktionsnetzes und einfacher kinetischer Ansätze qualitativ und quantitativ beschrieben werden. Dabei war neben dem Einfluss der Temperatur, der Einfluss der Eingangsmolenbrüche von Propan, Sauerstoff und Wasser zu untersuchen und zu quantifizieren.Parallel wurde der Einfluss der Gasphasenzusammensetzung auf die Sauerstoffaktivität unter Betriebsbedingungen untersucht. Dabei wurde erwartet mit Hilfe der simultanen potentiometrischen und kinetischen Messungen Rückschlüsse auf die Wirkungsweise des Katalysators ziehen zu können.

Partial oxidation of Raffinate II and other mixtures of n-Butane and n-Butenes to maleic anhydride in a fixed-bed reactor

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ISBN: 9783866441996 Year: Pages: VI, 186 p. DOI: 10.5445/KSP/1000007336 Language: ENGLISH
Publisher: KIT Scientific Publishing
Subject: Chemical Engineering
Added to DOAB on : 2019-07-30 20:02:01
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The utilisation of the C4 streams of steamcrackers by converting raffinate II to maleic anhydride was studied. The oxidation reactions were investigated in a laboratory-scale fixed-bed reactor to determine reaction kinetics. The effects of pore diffusional resistance were investigated and explained. A two-dimensional pseudo-homogeneous reactor model was used for the simulation of a production-scale fixed-bed reactor. A flow scheme of the reactor section including a recycle was proposed.

Electrocatalysis in Fuel Cells

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ISBN: 9783038422341 9783038422198 Year: Pages: XXX, 658 DOI: 10.3390/books978-3-03842-219-8 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Added to DOAB on : 2016-07-12 11:10:02
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Catalysis for Low Temperature Fuel Cells

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ISBN: 9783038426585 9783038426592 Year: Pages: 210 DOI: 10.3390/books978-3-03842-659-2 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Chemistry (General)
Added to DOAB on : 2018-01-24 13:49:23
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Today, the development of active and stable catalysts still represents a challenge to overcome in the research field of low temperature fuel cells. Operation at low temperatures demands the utilization of highly active catalysts to reduce the activation energy of the electrochemical reactions involved at the electrodes, and thus obtain practical performances and high efficiencies. At present, the most practical catalysts in low temperature fuel cells are highly dispersed Pt nanoparticles. However, these present several drawbacks such as high cost, limited earth resources, sensitivity to contaminants, low tolerance to the presence of alcohols and stability due to carbon support corrosion and Pt dissolution. In the search for alternative catalysts, researchers have looked at several strategies: increase of the utilization of Pt catalysts by means of novel structures (metal/support), alloying with non-platinum metals, new carbon and non-carbon supports, cheaper platinum-group-metals like Pd, non-platinum-group metals catalysts (Fe-N-C, Co-N-C, etc.), etc. This book is intended to cover the most recent progresses in advanced electro-catalysts from the synthesis and characterization to the evaluation of performance and degradation mechanisms, in order to gain insights towards the development of highly active fuel cells.

Current challenges in photosynthesis: From natural to artificial

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889192861 Year: Pages: 102 DOI: 10.3389/978-2-88919-286-1 Language: English
Publisher: Frontiers Media SA
Subject: Physiology --- Botany --- Science (General)
Added to DOAB on : 2015-12-10 11:59:07
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Jules Verne (1828-1905), author of Around the World in Eighty Days (1873) and Journey to the Center of the Earth (1864), wrote in 1875:"I believe that water will one day be used as a fuel, because the hydrogen and oxygen which constitute it, used separately or together, will furnish an inexhaustible source of heat and light. I therefore believe that, when coal (oil) deposits are oxidised, we will heat ourselves by means of water. Water is the fuel of the future". Solar energy is the only renewable energy source that has sufficient capacity for the global energy need; it is the only one that can address the issues of energy crisis and global climate change. A vast amount of solar energy is harvested and stored via photosynthesis in plants, algae, and cyanobacteria since over 3 billion years. Today, it is estimated that photosynthesis produces more than 100 billion tons of dry biomass annually, which would be equivalent to a hundred times the weight of the total human population on our planet at the present time, and equal to a global energy storage rate of about 100 TW. The solar power is the most abundant source of renewable energy, and oxygenic photosynthesis uses this energy to power the planet using the amazing reaction of water splitting. During water splitting, driven ultimately by sunlight, oxygen is released into the atmosphere, and this, along with food production by photosynthesis, supports life on our earth. The other product of water oxidation is “hydrogen” (proton and electron). This ‘hydrogen’ is not normally released into the atmosphere as hydrogen gas but combined with carbon dioxide to make high energy containing organic molecules. When we burn fuels we combine these organic molecules with oxygen. The design of new solar energy systems must adhere to the same principle as that of natural photosynthesis. For us to manipulate it to our benefit, it is imperative that we completely understand the basic processes of natural photosynthesis, and chemical conversion, such as light harvesting, excitation energy transfer, electron transfer, ion transport, and carbon fixation. Equally important, we must exploit application of this knowledge to the development of fully synthetic and/or hybrid devices. Understanding of photosynthetic reactions is not only a satisfying intellectual pursuit, but it is important for improving agricultural yields and for developing new solar technologies. Today, we have considerable knowledge of the working of photosynthesis and its photosystems, including the water oxidation reaction. Recent advances towards the understanding of the structure and the mechanism of the natural photosynthetic systems are being made at the molecular level. To mimic natural photosynthesis, inorganic chemists, organic chemists, electrochemists, material scientists, biochemists, biophysicists, and plant biologists must work together and only then significant progress in harnessing energy via “artificial photosynthesis” will be possible. This Research Topic provides recent advances of our understanding of photosynthesis, gives to our readers recent information on photosynthesis research, and summarizes the characteristics of the natural system from the standpoint of what we could learn from it to produce an efficient artificial system, i.e., from the natural to the artificial. This topic is intended to include exciting breakthroughs, possible limitations, and open questions in the frontiers in photosynthesis research.

Catalytic Removal of Volatile Organic Compounds

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ISBN: 9783038422136 9783038422143 Year: Pages: 290 DOI: 10.3390/books978-3-03842-214-3 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Added to DOAB on : 2016-07-12 11:17:23
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The metabolic challenges of immune cells in health and disease

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889196227 Year: Pages: 80 DOI: 10.3389/978-2-88919-622-7 Language: English
Publisher: Frontiers Media SA
Subject: Allergy and Immunology --- Medicine (General)
Added to DOAB on : 2016-08-16 10:34:25
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Obesity and its co-morbidities, including atherosclerosis, insulin resistance and diabetes, are a world-wide epidemic. Inflammatory immune responses in metabolic tissues have emerged as a universal feature of these metabolic disorders. While initial work highlighted the contribution of macrophages to tissue inflammation and insulin resistance, recent studies demonstrate that cells of the adaptive immune compartment, including T and B lymphocytes and dendritic cells also participate in obesity-induced pathogenesis of these conditions. However, the molecular and cellular pathways by which the innate and adaptive branches of immunity control tissue and systemic metabolism remain poorly understood. To engage in growth and activation, cells need to increase their biomass and replicate their genome. This process presents a substantial bioenergetic challenge: growing and activated cells must increase ATP production and acquire or synthesize raw materials, including lipids, proteins and nucleic acids. To do so, they actively reprogram their intracellular metabolism from catabolic mitochondrial oxidative phosphorylation to glycolysis and other anabolic pathways. This metabolic reprogramming is under the control of specific signal transduction pathways whose underlying molecular mechanisms and relevance to physiology and disease are subject of considerable current interest and under intense study. Recent reports have elucidated the physiological role of metabolic reprogramming in macrophage and T cell activation and differentiation, B- and dendritic cell biology, as well as in the crosstalk of immune cells with endothelial and stem cells. It is also becoming increasingly evident that alterations of metabolic pathways play a major role in the pathogenesis of chronic inflammatory disorders. Due to the scientific distance between immunologists and experts in metabolism (e.g., clinicians and biochemists), however, there has been limited cross-talk between these communities. This collection of articles aims at promoting such cross-talk and accelerating discoveries in the emerging field of immunometabolism.

Geomicrobes: Life in Terrestrial Deep Subsurface

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889451791 Year: Pages: 141 DOI: 10.3389/978-2-88945-179-1 Language: English
Publisher: Frontiers Media SA
Subject: Microbiology --- Science (General)
Added to DOAB on : 2017-08-28 14:01:09
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The deep subsurface is, in addition to space, one of the last unknown frontiers to human kind. A significant part of life on Earth resides in the deep subsurface, hiding great potential of microbial life of which we know only little. The conditions in the deep terrestrial subsurface are thought to resemble those of early Earth, which makes this environment an analog for studying early life in addition to possible extraterrestrial life in ultra-extreme conditions. Early microorganisms played a great role in shaping the conditions on the young Earth. Even today deep subsurface microorganisms interact with their geological environment transforming the conditions in the groundwater and on rock surfaces. Essential elements for life are richly present but in difficultly accessible form. The elements driving the microbial deep life is still not completely identified. Most of the microorganisms detected by novel molecular techniques still lack cultured representatives. Nevertheless, using modern sequencing techniques and bioinformatics the functional roles of these microorganisms are being revealed. We are starting to see the differences and similarities between the life in the deep subsurface and surface domains. We may even begin to see the function of evolution by comparing deep life to life closer to the surface of Earth. Deep life consists of organisms from all known domains of life. This Research Topic reveals some of the rich diversity and functional properties of the great biomass residing in the deep dark subsurface.

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