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Search Results: 1 - 10 of 14325 matches for " Andrea Kruse "
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Influence of RANEY Nickel on the Formation of Intermediates in the Degradation of Lignin
Daniel Forchheim,Ursel Hornung,Philipp Kempe,Andrea Kruse,David Steinbach
International Journal of Chemical Engineering , 2012, DOI: 10.1155/2012/589749
Abstract: Lignin forms an important part of lignocellulosic biomass and is an abundantly available residue. It is a potential renewable source of phenol. Liquefaction of enzymatic hydrolysis lignin as well as catalytical hydrodeoxygenation of the main intermediates in the degradation of lignin, that is, catechol and guaiacol, was studied. The cleavage of the ether bonds, which are abundant in the molecular structure of lignin, can be realised in near-critical water (573 to 673?K, 20 to 30?MPa). Hydrothermal treatment in this context provides high selectivity in respect to hydroxybenzenes, especially catechol. RANEY Nickel was found to be an adequate catalyst for hydrodeoxygenation. Although it does not influence the cleavage of ether bonds, RANEY Nickel favours the production of phenol from both lignin and catechol. The main product from hydrodeoxygenation of guaiacol with RANEY Nickel was cyclohexanol. Reaction mechanism and kinetics of the degradation of guaiacol were explored. 1. Introduction Earth?s resources of crude oil are limited [1]. An important challenge for scientists and engineers is to develop technologies that are largely independent from fossil crude oils. Biomass, especially organic waste material, has a high potential to replace crude oil as a basic input material for the production of many organic chemicals. Lignocellulosic biomass is one of the most abundant renewable organic materials in the world. Lignin, a major component of lignocellulosic biomass, is mostly available as waste material. The paper industry produces more than 50 million tons of dry lignin every year worldwide [2]. It is mainly burned to recover its energetic value. Lignin has a structure similar to brown coal, being an aromatic heteropolymer. The three basic building blocks, p-coumaryl alcohol, coniferyl alcohol, and sinapyl alcohol. are interlinked by C–C or ether bonds. The latter is the weaker one of the two bonds mentioned and thus of high interest for lignin degradation. As lignin is relatively resistant to chemical or enzymatic degradation, harsh reaction conditions are required to break down this polymer [3]. By cleavage of the ether bonds, aromatic monomers are formed. Thus lignin provides high potential to serve as a renewable source for phenol or benzene [4]. Phenol is extremely interesting as building block for synthetic polymers, resins, and epoxy- or polyurethane [3]. It is however a challenge to gain a high-value product from a chemically complicated and inhomogeneous component as lignin. In order to do so, char formation is to be avoided. Char formation can be
Effect of Reaction Temperature and Type of Catalyst on Hydrogen Production in Supercritical Water Gasification of Biomass
Ebrahimi-Nik Mohammadali,Mohammad Javad Sheikhdavoodi,Morteza Almassi,Andrea Kruse
Iranica Journal of Energy and Environment (IJEE) , 2012,
Abstract: The aim of this study was to investigate the feasibility of hydrogen production from sugarcane bagasse by supercritical water gasification (SCWG) at low temperature and in presence of alkali catalyst. Experiments were carried out in a batch autoclave reactor at 400 °C and 9% solid content. Effect of reaction time and alkali catalyst on gas yield, gas composition, carbon gasification efficiency (CGE) and hydrogen gasification efficiency (HGE) were investigated. Influence of reaction time on gas yield and composition as well as on CGE was found to be insignificant. Extending the reaction time even up to 4 h could not cause an attractive conversion of bagasse. In the presence of catalysts (K2CO3, KHCO3, NaHCO3 and NaOH), sugarcane bagasse was partially gasified in SCW and hydrogen-rich gas containing CO2 as the main carbon compound was produced. Among the implemented catalysts, K2CO3 was identified to be the most effective for improvement of HGE. Use of the catalyst under our experimental conditions, the maximum HGE of 19% was achieved; however the highest CGE occurred with KHCO3. Results showed that feed to catalyst ratio of 2 was high enough to reach the greatest possible gasification of hydrogen at 400 °C and 45 min. More CGE and HGE would be possible only by increasing the temperature, pressure and/or reaction time.
Economic Evaluation of Brief Psychodynamic Interpersonal Therapy in Patients with Multisomatoform Disorder
Nadja Chernyak, Heribert Sattel, Marsel Scheer, Christina Baechle, Johannes Kruse, Peter Henningsen, Andrea Icks
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0083894
Abstract: Background A brief psychodynamic interpersonal therapy (PIT) in patients with multisomatoform disorder has been recently shown to improve health-related quality of life. Aims To assess cost-effectiveness of PIT compared to enhanced medical care in patients with multisomatoform disorder. Method An economic evaluation alongside a randomised controlled trial (International Standard Randomised Controlled Trial Number ISRCTN23215121) conducted in 6 German academic outpatient centres was performed. Incremental cost-effectiveness ratio (ICER) was calculated from the statutory health insurance perspective on the basis of quality adjusted life years (QALYs) gained at 12 months. Uncertainty surrounding the cost-effectiveness of PIT was presented by means of a cost-effectiveness acceptability curve. Results Based on the complete-case analysis ICER was 41840 Euro per QALY. The results did not change greatly with the use of multiple imputation (ICER = 44222) and last observation carried forward (LOCF) approach to missing data (ICER = 46663). The probability of PIT being cost-effective exceeded 50% for thresholds of willingness to pay over 35 thousand Euros per QALY. Conclusions Cost-effectiveness of PIT is highly uncertain for thresholds of willingness to pay under 35 thousand Euros per QALY.
Hydrothermal Liquefaction of Lignin  [PDF]
Julia Schuler, Ursel Hornung, Andrea Kruse, Nicolaus Dahmen, J?rg Sauer
Journal of Biomaterials and Nanobiotechnology (JBNB) , 2017, DOI: 10.4236/jbnb.2017.81007
Abstract: The majority of platform chemicals are currently provided through crude oil processes. Nevertheless, the substitution of the crude oil with biomass should be the ecological aim. Lignin, an aromatic macromolecule, may play an important role in that exchange, as it is the only bio based source of aromatic compounds. For instance, it could be a source of bifunctional aromatic molecules, like the monocyclic compounds catechol or guaiacol, or bifunctional oligomers. However, no process for the production of aromatics from lignin in technical scale has been established until now. Hence, the focus of this work is to clarify the chemical degradation mechanism under hydrothermal conditions, to liquefy lignin delivering high functional molecules and to increase the yield and selectivity of the cleavage towards bifunctional molecules like catechol. The combination of fast hydrolysis, thermal degradation reactions and hydrogenation drives the hydrothermal liquefaction; this gives the possibility to narrow down the product spectrum in comparison to other “dry” cleavage methods, towards a higher yield of e.g. catechols.
Compreendendo o ambiente em Psicologia Ambiental
Kruse, Lenelis;
Psicologia USP , 2005, DOI: 10.1590/S0103-65642005000100006
Abstract: the present article consists of answers to the following questions, proposed and answered by the author: how do you, as an environmental psychologist or an environment-behavior researcher, define environment? how do you, as an environmental psychologist or an environment-behavior researcher, take the environment into account in your research? what kind of theories do we need so we can analyze people-environment relations more effectively? do you think the interaction between people and the environment has been sufficiently and adequately explained by environmental psychology? if the answer is no, in what way could this interaction be explained more satisfactorily? should we be constructing or collecting different types of information or knowledge to create more useful explanatory theories? what do you think is lacking in environmental psychology research? what is your disciplinary background? when you worked with other disciplines or professions, what behavior-environment research methodologies did you use? which were the most useful and why?
Conservative approaches to the management of voice disorders
Kruse, Eberhard
GMS Current Topics in Otorhinolaryngology, Head and Neck Surgery , 2005,
Abstract: The presence of a voice disorder not only affects social interaction but potentially also has a major impact on the work environment. The latter is becoming more important given the increasing demands employers make in terms of competency in both communication skills and adequacy of phonation. The development of newer and more precise phono-microsurgical techniques for the treatment of an increasing variety of voice disorders has not entirely replaced a conservative approach to voice rehabilitation. Nevertheless, conservative methods have to demonstrate an higher effectiveness in comparison with the microsurgical intervention given the alternative indications. This would be especially true for the more specific and systematically a given individual glottic pathophysiology could be changed in direction of individual phonatory physiology or supplementary phonation mechanism. This desired changing depends not only on the theoretical concepts but also on maintaining strict therapeutic principles during their clinical application. Conservative management of voice disorders has to be intensive and comprehensive, especially in the case of accepting our model of Larnygeal Double Phonation Function and the existence of a phonatory feedback loop.
Reading Qualitative Social Research Interculturally: The Reflection of Self-interpretation in the Act of Interpersonal Understanding (Fremdverstehen) Lectura intercultural en la investigación social cualitativa: La reflexión de la auto-interpretación en el acto de la comprensión interpersonal (Fremdverstehen) Qualitative Sozialforschung – interkulturell gelesen: Die Reflexion der Selbstauslegung im Akt des Fremdverstehens
Jan Kruse
Forum : Qualitative Social Research , 2008,
Abstract: In this contribution, I attempt to justify the following two assumptions: Firstly, that intercultural communication is, at its heart, the communicative paradigm of qualitative interview-based research; and secondly that, vice versa, qualitative interview-based research is the methodical paradigm of intercultural communication. On the one side—from a linguistic point of view—the qualitative paradigm, with its methodical principles of communicability and context sensibility, cannot solve the problem of the indexicality of human language and communication—although the qualitative paradigm can indeed work on this problem prolifically. Handling and processing indexicality is, in this case, also a core task for intercultural communication. On the other side: Processing the linguistic problems of indexicality itself stands in the shadow of the epistomological problem of other-awareness (Fremdverstehen according to Alfred SCHüTZ). In the same way in which Fremdverstehen represents the central mode of intercultural communication, the methodical control of Fremdverstehen—developed within the paradigm of reconstructive research—is the core mode of qualitative interview-based research. Thus, qualitative interview-based research and intercultural communication clearly converge in two aspects. The theoretical thoughts presented in this contribution are, in a second step, illustrated by a practical example. URN: urn:nbn:de:0114-fqs0901162 El presente trabajo busca fundamentar dos tesis. Primero: que la comunicación intercultural, de hecho, constituye el paradigma comunicativo de la investigación cualitativa basada en la entrevista ; y segundo: que en viceversa, la investigación cualitativa basada en la entrevista es el paradigma metodológico de la comunicación intercultural. De ahí que, aunque por un lado el paradigma cualitativo, desde una perspectiva lingüística y con sus principios básicos metodológicos de la comunicatividad y la sensibilidad de contexto, no pueda resolver el problema de la indexicalidad del lenguaje humano y de la comunicación, sí pueda, sin embargo, analizarlo prolíficamente. La revisión y el análisis de la indexicalidad son, en este sentido, tarea central de la comunicación intercultural. Por otro lado, el análisis de los problemas lingüísticos de la indexicalidad se encuentra bajo la sombra del problema epistemológico de la "comprensión del otro" (Fremdverstehen, de acuerdo con Alfred SCHüTZ). Así como la "comprensión del otro" es el método esencial de la comunicación intercultural; el control metodológico de la "comprensión del otro", desarroll
Formació professional dins de l'empressa: un potencial de modernització? El sistema dual a la República Federal d'Alemanya
Wilfried Kruse
Temps d'Educació , 1991,
Food safety and international competitiveness: the case of beef
Kruse Hilde
Bulletin of the World Health Organization , 2002,
Cross Section Measurements of High-$p_T$ Dilepton Final-State Processes Using a Global Fitting Method
M. Kruse
Physics , 2006, DOI: 10.1103/PhysRevD.78.012003
Abstract: We present a new method for studying high-$p_T$ dilepton events ($e^{\pm}e^{\mp}$, $\mu^{\pm}\mu^{\mp}$, $e^{\pm}\mu^{\mp}$) and simultaneously extracting the production cross sections of $p\bar{p} \to t\bar{t}$, $p\bar{p} \to W^+W^-$, and $p\bar{p} \to \ztt$ at a center-of-mass energy of $\sqrt{s} = 1.96$ TeV. We perform a likelihood fit to the dilepton data in a parameter space defined by the missing transverse energy and the number of jets in the event. Our results, which use $360 {\rm pb^{-1}}$ of data recorded with the CDF II detector at the Fermilab Tevatron Collider, are $\sigma(t\bar{t}) = 8.5_{-2.2}^{+2.7}$ pb, $\sigma(W^+W^-) = 16.3^{+5.2}_{-4.4}$ pb, and $\sigma(\ztt) =291^{+50}_{-46}$ pb.
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