Dissertations / Theses on the topic 'Activator method'

The nuclear design of fusion devices such as ITER (International Thermonuclear Experimental Reactor), which is an experimental fusion reactor based on the "tokamak" concept, rely on the results of neutron physical calculations. These depend on the knowledge of the neutron and photon flux spectra which is particularly important because it permits to anticipate the possible answers of the whole structure to phenomena such as nuclear heating, tritium breeding, atomic displacements, radiation shielding, power generation and material activation. The flux spectra can be calculated with transport codes, but validating measurements are also required. An important constituent of structural materials and divertor areas of fusion reactors is tungsten. This thesis deals with the measurement of the neutron fluence and neutron energy spectrum in a tungsten assembly by means of multiple foil neutron activation technique. In order to check and qualify the experimental tools and the codes to be used in the tungsten benchmark experiment, test measurements in the D-T and D-D neutron fields of the neutron generator at Technische Universität Dresden were performed. The characteristics of the D-D and D-T reactions, used to produce monoenergetic neutrons, together with the selection of activation reactions suitable for fusion applications and details of the activation measurements are presented. Corrections related to the neutron irradiation process and those to the sample counting process are discussed, too. The neutron fluence and its energy distribution in a tungsten benchmark, irradiated at the Frascati Neutron Generator with 14 MeV neutrons produced by the T(d, n)4He reaction, are then derived from the measurements of the neutron induced γ-ray activity in the foils using the STAYNL unfolding code, based on the linear least-square-errors method, together with the IRDF-90.2 (International Reactor Dosimetry File) cross section library. The differences between the neutron flux spectra measured by means of neutron foil activation and the neutron flux spectra obtained in the same assembly, making use of an NE213 liquid-scintillation spectrometer were studied. The comparison of measured neutron spectra with the spectra calculated with the MCNP-4B (Monte Carlo neutron and photon transport) code, which allows a crucial test of the evaluated nuclear data used in fusion reactor design, is discussed, too. In conclusion, this thesis shows the applicability of the neutron foil activation technique for the measurement of neutron flux spectra inside a thick tungsten assembly irradiated with 14 MeV from a D-T generator
Die Konstruktion von Fusionsreaktoren wie ITER (International Thermonuclear Experimental Reactor), der ein experimenteller Fusionsreaktor ist und auf dem "Tokamak"-Konzept beruht, basiert unter neutronenphysikalischen Gesichtspunkten auf den Ergebnissen von umfangreichen Simulationsrechnungen. Diese setzen die Kenntnis der Spektren des Neutronen- und Photonenflusses voraus die besonders wichtig ist, weil sie, die möglichen Antworten der ganzen Struktur auf physikalische Prozesse vorauszuberechnen erlaubt wie z.B.: Heizen durch nukleare Prozesse, Tritium-Brüten, Atomverschiebung, Abschirmung von Strahlung, Leistungserzeugung und Materialaktivierung. Die Flußspektren können mittels Transportcodes berechnet werden, aber es werden auch Messungen zu ihrer Bestätigung benötigt. Ein wichtiger Bestandteil des Strukturmaterials und der Divertor-Flächen der Fusionsreaktoren ist Wolfram. Diese Dissertation behandelt die Messungen der Neutronspektren und ?fluenz in einer Wolfram-Anordnung mittels der Multifolien-Neutronenaktivierungstechnik. Um die anzuwendenden experimentellen Geräte und die Codes, die im Wolfram-Benchmark-Experiment eingesetzt werden, zu überprüfen und zu bestimmen, wurden Testmessungen in den D-T und D-D Neutronenfeldern des Neutronengenerator der Technischen Universität Dresden durchgeführt. Die Eigenschaften der D-T und D-D Reaktionen, die für die Erzeugung von monoenergetischen Neutronen verwendet werden, sowie die Auswahl der Aktivierungsreaktionen, die für Fusionsanwendungen geeignet sind und die Aktivierungsmessung werden detailliert vorgestellt. Korrekturen, die sich auf den Neutronen-Bestrahlungsprozess und auf den Probenzählungsprozess beziehen, werden ebenfalls besprochen. Die Neutronenfluenz und ihre Energieverteilung in einem Wolfram-Benchmark, bestrahlt am Frascati Neutronen Generator mit 14 MeV-Neutronen aus der T(d, n)4He Reaktion, werden aus den Messungen der γ-Strahlenaktivität, die von Neutronen in den Folien induziert ist, durch den STAYNL Entfaltungscode, der auf der Methode der kleinsten Fehlerquadrate basiert, zusammen mit der IRDF-90.2 Wirkungsquerschnitt-Bibliothek abgeleitet. Die Unterschiede zwischen den Neutronenflußspektren, die mit Hilfe der Multifolien-Neutronenaktivierung ermittelt wurden, und den Neutronenflußspektren, gemessen im selben Aufbau mit einem NE-213 Flüssigszintillator, wurden untersucht. Die gemessenen Neutronenspektren werden den aus MCNP-4B Rechnungen (Monte Carlo neutron and photon transport) ermittelten Spektren gegenüber gestellt. Der Vergleich stellt einen wichtigen Test der evaluierten Kerndaten für Fusionsreaktorkonzepte dar. Zusammenfassend zeigt diese Arbeit die Anwendbarkeit der Multifolien-Neutronenaktivierungstechnik bei Messungen der Neutronenflussspektren innerhalb eines massiven Wolframblocks bei Bestrahlung mit schnellen Neutronen aus D-T Generatoren

NMR studies have long been used as a tool to derive structural and dynamic information. Such information has a wide range of applications, and notably is used in the study of structure-activity relationships. The aims of this work were to use NMR spectroscopy to derive structures of the molecules inhibiting the activation of the alternative pathway of the complement portion of the innate immune system (namely, the N-terminus of factor H (FH) and two small peptides, Compstatin 10 and Compstatin 20) and to consider the interdomain dynamics of proteins consisting of three modules theoretically (in silico) and experimentally (for the three N-terminal domains of FH). We focused on the three N-terminal complement control protein (CCP) domains of the important complement regulator, human factor H (i.e. FH1-3). Its three-dimensional solution structure was derived based on nuclear Overhauser effects and residual dipolar couplings (RDCs). Each of the three CCP modules in this structure was similar to the corresponding CCP in the previously derived C3b-bound structure of FH1-4, but the relative orientations of the domains were different. These orientations were additionally different from the interdomain orientations in other molecules that interact with C3b, such as DAF2-4 and CR1-15-17. The measured RDC datasets, collected under three different conditions in media containing magnetically aligned bicelles (disk-like particles formed from phospholipids), were used to estimate interdomain motions in FH1-3. A method in which the data was fitted to a structural ensemble was used to analyze such interdomain flexibility. More than 80% of the conformers of this predominantly extended three-domain molecule exhibit flexions of < 40°. Such segmental flexibility (together with the local dynamics of the hypervariable loop within domain 3) could facilitate recognition of C3b via initial anchoring, as well as eventual reorganization of modules into the conformation captured in the previously solved crystal structure of a C3b complex with FH1-4. The NMR study of the Compstatin analogues revealed unique structural features that had not before been observed in this group of peptides. These features included two b-turns per peptide, neither of which was located in the ‘canonical’ regions in which b-turns were observed in previous molecular dynamics and NMR studies. The structures of Compstatin 10 and Compstatin 20 derived here were consistent with the isothermal calorimetry (ITC) and surface plasmon resonance (SPR) data recorded previously. In the in silico study of interdomain motion of three-domain proteins carried out here, the domains were represented as vectors attached to one another in a linear fashion. They were allowed to undergo Brownian motion biased by the potentials between the sequential vectors. The resulting trajectories were analyzed using model-free and extended model-free formalism. The degree of coupling of the interdomain motion with overall motion was determined, along with a representation of the overall motion. The similarity between the trajectories of the vectors transformed to this overall motion frame and the results obtained from the model-free analysis was determined.

This master‘s thesis deals with computational modelling of human vocal folds in phonation position using finite element method. There are described larynx anatomy, voice generation theories and overview of so far published computational models of vocal folds. Next part of the paper deals with a redesign of vocal folds and soft tissues‘ geometry, creation of finite element mesh and implementation of active stress in thyroarytenoid muscle. The problem was solved using Ansys 19.2 software. Computation of stress and deformation of soft tissues in phonation position has been made for 7 variations with different combination of active cartilages and muscles. Lastly, there was evaluated an effect of different cartilages and active muscle stress to final stress and deformation of soft tissues of vocal folds.

Contexto: Esta tese procurou estabelecer um novo método de mensuração instantânea de fadiga central e periférica durante o exercício de corpo inteiro até a capacidade aeróbica máxima em seres humanos. Até agora, a mensuração da fadiga central e periférica tem sido limitada a tarefas musculares isoladas ou a momentos específicos após o exercício, nos quais as condições fisiológicas que levaram aos sintomas limitantes do exercício já estão abrandadas. Assim, desenvolver um método que supere estas limitações permitiria demonstrar pela primeira vez as contribuições relativas da fadiga central e periférica na limitação ao exercício, no qual haja estimulação máxima dos sistemas neuromuscular e cardiovascular. Objetivo: Desenvolver e validar um método para quantificar a fadiga muscular periférica (MF, definida como a potência produzida para uma determinada estimulação muscular), fadiga de ativação (AF, definida como a atividade muscular evocável máxima), sua soma, fadiga de desempenho (PF, definida como a perda de potência isocinética voluntária máxima em comparação com a basal) durante o exercício realizado no cicloergômetro em capacidade aeróbica máxima. Além disso, esta tese teve como objetivo determinar as taxas de recuperação nas quais MF, AF e PF retornaram à linha de base após a intolerância durante o exercício de corpo inteiro em seres humanos. Métodos: Para quantificar a fadiga durante o exercício de corpo inteiro, foi desenvolvido um método para permitir uma rápida transição do ciclismo padrão (em que a relação entre potência e cadência é hiperbólica) para o ciclismo isocinético (em que a potência é independente da cadência, e a cadência é fixa). Assim, ao pedir para o participante realizar um esforço isocinético máximo em qualquer ponto durante o exercício ou na fase de recuperação, permitiu-se quantificar o declínio velocidade-específica da potência isocinética máxima (PISO). A diferença na PISO entre a linha de base e o exercício quantifica a PF. Foi testado se a relação de base entre PISO e potência eletromiográfica em 5 músculos da perna (RMS EMG) era velocidade dependente, linear e reprodutível, de tal modo que as contribuições relativas para PF pudessem ser isoladas a partir de: 1) a diminuição da ativação muscular (AF) ; e 2) o declínio na PISO num dado grau de ativação (MF). Resultados: Participantes saudáveis (n=13, 29-72 anos, variando em capacidade aeróbica de 23,5 até 62,4 ml/min/kg) completaram tiros isocinéticos esforço-variável de curta duração (5 s) a 50, 70 e 100 rpm para caracterizar a relação basal entre EMG RMS e potência isocinética. As correlações entre EMG-Piso basais foram lineares (r2= 0,95 ± 0,04) e velocidade dependente (análise de covariância). Posteriormente, testes de exercício incrementais repetidos foram realizados em uma bicicleta ergométrica e as trocas gasosas e a ventilação foram mensuradas respiração a respiração. O exercício encerrava com um esforço isocinético máximo (5 s) a 70 rpm. Na intolerância, PISO (duas pernas, 335 ± 88 W) foi ~ de 45% menos do que na linha de base (630 ± 156 W, p <0,05). Após a intolerância, houve recuperação da PISO em 3 minutos (p <0,05). AF e MF (medido em uma perna) foram de 97 ± 55 e 60 ± 50 W, respectivamente. As médias de viés (± limites de concordância) para a reprodutibilidade foram as seguintes: PISO na linha de base 1 ± 30 W; PISO na recuperação 0-min 3 ± 35 W; e EMG em PISO 3 ± 14%. Conclusões: A relação basal EMG-PISO foi bem modelada por uma função linear, que foi reprodutível no dia-a-dia. A variabilidade das mensurações EMG-PISO individuais entre ~ 25% e 100% de esforço, em torno do modelo linear, foi suficientemente forte de modo que a relação linear basal permitiu uma quantificação precisa de AF e MF no limite de tolerância e na recuperação do exercício aeróbico máximo. Foi também demonstrado que a relação EMG-PISO foi velocidade dependente, como esperado a partir da curva parabólica de potência-velocidade. Assim, esta tese apresenta um novo método útil para identificar as contribuições da fadiga central e periférica na limitação do exercício de corpo inteiro em seres humanos.
Background: This thesis sought to establish a new method for instantaneous measurement of central and peripheral fatigue during whole-body exercise up to maximal aerobic capacity in humans. Until now, measurement of central and peripheral fatigue has been limited to isolated muscle tasks or to time points after exercise where the physiological conditions that brought about the limiting symptoms for exercise have subsided. Thus, development of a method to overcome this would allow the first demonstration of the relative contributions of central and peripheral fatigue to limiting exercise that elicited maximal strain of the combined neuromuscular and cardiopulmonary systems. Objective: To develop and validate a method for quantifying peripheral muscle fatigue (MF, defined as the power produced for a given muscle stimulation), activation fatigue (AF, defined as the maximal evocable muscle activity), their sum, performance fatigue (PF, defined as the decline in maximal voluntary isokinetic power compared to the fresh, baseline, state) during cycling exercise at maximal aerobic capacity. In addition, this thesis aimed to determine the rate with which MF, AF and PF recovered to baseline after intolerance during whole-body exercise in humans. Methods: To quantify fatigue during whole-body exercise, a method was developed to allow a rapid switch from standard cycling (where the relationship between power and cadence is hyperbolic) to isokinetic cycling (where power is independent of cadence, and cadence is fixed) to be implemented. By asking the participant to give a maximal isokinetic effort at any point during exercise or recovery, allowed the velocity-specific decline in maximal isokinetic power (PISO) to be measured. The difference in PISO between baseline and exercise quantified PF. It was tested whether the baseline relationship between PISO and electromyographic power in 5 leg muscles (RMS EMG) was velocity dependent, linear and reproducible, such that the relative contributions to PF could be isolated from: 1) the decline in muscle activation (AF); and 2) the decline in PISO at a given activation (MF). Results: Healthy participants (n=13, 29 to 72 years old, ranging in aerobic capacity from 23.5 to 62.4 ml/min/kg) completed short (5 s) variable-effort isokinetic bouts at 50, 70, and 100 rpm to characterize the baseline relationship between RMS EMG and isokinetic power. Individual baseline EMG-PISO relationships were linear (r2 = 0.95 ± 0.04) and velocity dependent (analysis of covariance). Subsequently, repeated ramp incremental exercise tests were performed on a cycle ergometer and breath-by-breath gas exchange and ventilation was measured. Exercise was terminated with a maximal isokinetic effort (5 s) at 70 rpm. PISO at intolerance (two legs, 335 ± 88 W) was ~45% less than baseline (630 ± 156 W, p < 0.05). Following intolerance, PISO recovered within 3 minutes (p < 0.05). AF and MF (measured in one leg) were 97 ± 55 and 60 ± 50 W, respectively. Mean bias (± limits of agreement) for reproducibility were as follows: PISO at baseline 1 ± 30 W; PISO at 0-min recovery 3 ± 35 W; and EMG at PISO 3 ± 14%. Conclusions: The baseline EMG-PISO relationship was well modelled by a linear function, which was reproducible day-to-day. The variability of the individual EMG-PISO measurements between ~25% and 100% effort, around the linear model, was sufficiently tight that the baseline linear relationship allowed for a precise quantification of AF and MF at the limit of tolerance and in recovery from a maximal aerobic exercise task. It was also demonstrated that the EMG-PISO relationship was velocity dependent, as expected from the parabolic nature power-velocity curve. As such, this provides a valuable new method to identify the contributions of central and peripheral fatigue to limiting whole-body exercise in humans.

A heavily filtered fast neutron irradiation system (FNIS) was developed for a variety of applications, including the study of long-term health effects of fast neutrons by evaluating the biological mechanisms of damage in cultured cells and living animals such as rats or mice. This irradiation system includes an exposure cave made with a lead-bismuth alloy, a cave positioning system, a gamma and neutron monitoring system, a sample transfer system, and interchangeable filters. This system was installed in the irradiation cell of the Texas A&M University Nuclear Science Center Reactor (NSCR). By increasing the thickness of the lead-bismuth alloy, the neutron spectra were shifted into lower energies by the scattering interactions of fast neutrons with the alloy. It is possible, therefore, by changing the alloy thickness, to produce distinctly different dose weighted neutron spectra inside the exposure cave of the FNIS. The calculated neutron spectra showed close agreement with the results of activation foil measurements, unfolded by SAND-II close to the cell window. However, there was a considerable less agreement for locations far away from the cell window. Even though the magnitude of values such as neutron flux and tissue kerma rates in air differed, the weighted average neutron energies showed close agreement between the MCNP and SAND-II since the normalized neutron spectra were in a good agreement each other. A paired ion chamber system was constructed, one with a tissue equivalent plastic (A-150) and propane gas for total dose monitoring, and another with graphite and argon for photon dose monitoring. Using the pair of detectors, the neutron to gamma ratio can be inferred. With the 20 cm-thick FNIS, the absorbed dose rates of neutrons measured with the paired ion chamber method and calculated with the SAND-II results were 13.7 ?? 0.02 Gy/min and 15.5 Gy/min, respectively. The absorbed dose rate of photons and the gamma contribution to total dose were 6.7??10-1 ?? 1.3??10-1 Gy/min and 4.7%, respectively. However, the estimated gamma contribution to total dose varied between 3.6 % to 6.6 % as the assumed neutron sensitivity to the graphite detector was changed from 0.01 to 0.03.

Thesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology, 2009
This project was started as a result of strict environmental and health regulations together with a demand tor cost effective operation of wastewater treatment plants (VVWTPs). The main aim of this project is how to keep effluent concentration below a prescribed limit at the lowest possible cost. Due to large fluctuations in the quality and quantity of the influent concentrations, traditional control methods are not adequate to achieve this aim The major drawback with these methods is that the disturbances affect the process before the controller has time to correct the error (Olsson and Newell, 1999: 454). This problem is addressed through the use of modern control systems. Modern control systems are model based predictive algorithms arranged as feed-forward controllers (Olsson and Newell. 1999: 454). Normally a controller is equipped with a constant set point; the goal In this project is to calculate an optimal DO trajectory that may be sampled to provide a varying optimal set-point for the Activated Sludge Process, In this project an optimal control problem Is formulated using DO concentration as a control variable. This requires a model of the process to be controlled a mathematical expressions of the limitations on the process input and output variables and finally the objective functional. which consists of the objectives of the control. The structures of the Benchmark plant (developed within the COST 682 working group) and the Athlone WWTPs are used to implement this opt.mat control strategy in MATLAB. The plant's full models are developed based on the mass balance principle incorporating the activated sludge biological models: ,ASM1, ASM2, ASM2d and ASM3 (developed by the IWA working groups). To be able to develop a method that may later on be used for online control, the full models are reduced based on the technique In Lukasse (1996). To ensure that the reduced models keep the same prediction capabilities as the full models, parameters of the reduced models are calculated based on the Least Squares principle, The formulated optimal control problem is solved based on the decompostion-coorcdination method that involves time decomposition in a two layer structure. MATLAB software [5 developed to solve the problems for parameter estimation. fun and reduced mode! simulation. and optimal control calculation for the considered different cases of plant structures and biological models. The obtained optimal 00 trajectories produced the effluent state trajectories within prescribed requirements. These DO trajectories may be implemented in different SCADA systems to be tracked as set points or desired trajectories by different types of controllers.

This article reviews the Electronically Activated Recorder (EAR) as an ambulatory ecological momentary assessment tool for the real-world observation of daily behavior. Technically, the EAR is an audio recorder that intermittently records snippets of ambient sounds while participants go about their lives. Conceptually, it is a naturalistic observation method that yields an acoustic log of a person’s day as it unfolds. The power of the EAR lies in unobtrusively collecting authentic real-life observational data. In preserving a high degree of naturalism at the level of the raw recordings, it resembles ethnographic methods; through its sampling and coding, it enables larger empirical studies. This article provides an overview of the EAR method; reviews its validity, utility, and limitations; and discusses it in the context of current developments in ambulatory assessment, specifically the emerging field of mobile sensing.

Filamentous bulking is a problem that has long plagued activated sludge (AS) wastewater treatment plants (WWTPs). Much research has looked at its prevention and control but there is still no solution. The sludge microbiological community is very complex and there are many factors that can affect bulking. Clay addition in scaled-down activated sludge systems was investigated at concentrations of 0.4, 2.0 and 5.0 g/L along with sequencing batch reactor (SBR) parameters when run with a synthetic wastewater (SWW). The 5.0g/L concentration exhibited positive results on settling in the form of modified SVI but appeared to cause no reduction in filament length. These preliminary investigations indicate that clay may help improve sludge settling but make no difference in the abundance of filamentous microorganisms. The SBRs exhibited trends in regards to running systems with a synthetic wastewater. A loss of volatile suspended solids (VSS), coupled with increase in sludge volume index (SVI), suggested a link between lack of non-VSS and settling ability. This has implications in the importance of non-VSS such as grit or clay in research performed using SWWs.

The relative efficiencies of low energy (< 100 eV) collisional activation techniques were determined for peptide sequencing by tandem mass spectrometry (MS/MS). Tryptic peptides were fragmented using either collision induced dissociation (CID) or surface induced dissociation (SID) to generate spectral databases. Statistical analysis of the resulting fragment ions and success rates for automated peptide sequencing by publicly available algorithms provided a measure of the value of sequencing information content of CID and SID MS/MS spectra. Typical success rates were determined for automated sequencing by SEQUEST¹⁻³, MS-Tag⁴, Mascot's⁵ MS/MS Ion Search and Sequence Query using low energy CID spectra. The ability of an algorithm to match peptide sequences to raw MS/MS data directly depended on various factors including the mass spectrometer from which the spectra were acquired, the precursor ion charge state, and the mass accuracy and resolution available in the spectra. Statistical analysis demonstrated the presence of similar fragment ions in SID and CID spectra. A lack of long contiguous ion series in SID spectra prevented automated sequencing using conventional approaches. Thus, "patchwork peptide sequencing"⁶, an unconventional method to derive specific sequence criteria for unknown peptides from SID spectra, was performed. Submitting this information to Mascot's Sequence Query allowed database searching strategies to achieve automated peptide sequencing with SID spectra. Some aspects of gas phase ion chemistry were explored for the unexpected formation of fragment ions from cleavage C-terminal to proline residues. Semi-empirical calculations suggest the most stable structure for valineprolyl-b₂ ion is a diketopiperazine, although the MS/MS/MS fragmentation pattern for VP-b₂ is indicative of an oxazalone structure. Support for a diketopiperazine structure is provided by similar fragmentation patterns for VP-b₂ and a synthetic diketopiperazine VP, and prevention of the formation of VP-b₂ by acetylation of the free N-terminus. Substitution of N-methyl alanine for proline produces a b₂ ion that fragments by loss of a portion of the valine residue, consistent with an oxazalone structure. However, theoretical calculations suggest the N-methyl alanine-containing b₂ ion is a diketopiperazine. The differences in fragmentation patterns indicate that the gas phase ion structures for the proline- and N-methyl alanine-containing b₂ ions are different, although stability calculations suggest otherwise.

The recent development of culture-independent methods has revolutionized the study of complex microbial communities such as those present in activated sludge treatment systems. DNA probes that hybridize to genes coding for key enzymes that catalyze microbial processes have been widely used. Can such probes be used to quantify target genes and thus quantify the potential of a microbial community to carry out a reaction of interest?
Optimal conditions for DNA extraction, probe validation, hybridization, and activity measurements were determined for the pulp and paper treatment system environment under study. Using gene probes for key denitrification genes (nirS, nirK), the correlation between denitrifiers and denitrification activity in an enrichment culture and activated sludge samples was tested. The same correlation between nitrogen fixation and nitrogen-fixing bacteria in primary clarifiers was assessed using a probe for the gene encoding a component of the nitrogenase enzyme (nifH). This work was successful in establishing the correlation between gene numbers and their corresponding enzymatic activity and thus supports the quantitative hybridization approach for the monitoring of microbial communities. (Abstract shortened by UMI.)

Abstrakt In my thesis I deal with the activation methods. The aim of this is to explain the students given topic using several activation methods with following test, which should give feedback of the results achieved. I wanted to research whether the activation methods affect students knowledge. I also wanted to know the students opinion on those methods and find out, if they are used by teachers of economics. I divided the diploma thesis into two parts, theory and research. In the theoretical part I describe the education on schools of economics, forms of organization, educational methods mainly the activation ones. In research I describe the procedure of my experiment. The crucial part is the analysis of the didactic tests results, which was done by the students and it is completed with the questionnaires results. I point out the impact of using the activation methods in teaching and the benefits for students, who gain the practical knowledge.

The use of nano zerovalent iron (nZVI) for environmental remediation is a promising new technique for in situ remediation. Due to its high surface area and high reactivity, nZVI is able to dechlorinate organic contaminants and render them harmless. Limited mobility, due to fast aggregation and sedimentation of nZVI, limits the capability for source and plume remediation. Carbo-Iron is a newly developed material consisting of activated carbon particles (d50 = 0,8 µm) that are plated with nZVI particles. These particles combine the mobility of activated carbon and the reactivity of nZVI. This paper presents the rst results of the transport experiments.
Der Einsatz von elementarem Nanoeisen ist eine vielversprechende Technik zur Sanierung von Altlastenschadensfällen. Aufgrund der hohen Oberäche und der hohen Reaktivität kannn ZVI chlororganische Schadstoffe dechlorieren und zu harmlosen Substanzen umwandeln. Der Einsatz von Nanoeisen zur Quellen- und Fahnensanierung wird jedoch durch mangelnde Mobilität im Boden im eingeschränkt. Carbo-Iron ist ein neu entwickeltes Material, das aus Aktivkohlepartikeln (d50 = 0,8 µm) und nZVI besteht. Diese Partikel kombinieren die Mobilit ät von Aktivkohle mit der Reaktivität von nZVI. Dieser Artikel beschreibt erste Ergebnisse von Transportuntersuchungen.