Untersuchungen zur Anwendung und Optimierung des passiv akustischen Verfahrens zur Korngrößenanalyse in der Steine- und Erdenindustrie

Durch den Ausbau neuer Technologien und aufgrund steigender Lebensstandards, vor allem in Schwellenländern, ist der globale Bedarf an mineralischen Rohstoffen in den letzten Jahrzehnten immer weiter gestiegen [1]. Um die stetige Nachfrage zu bedienen, werden weltweit jährlich mineralische Rohstoffe in einem Gesamtwert zwischen 600 und 900 Mrd. USD im Bergbau gewonnen (2017 gesamt 687 Mrd. USD) [2]. Nach der Gewinnung werden diese Rohstoffe in verschiedenen Prozessen aufbereitet. Ziel der Rohstoffaufbereitung ist es, die Rohstoffe für die verschiedenen industriellen Verwendungen zu konditionieren. Die Analyse von Korngrößenverteilungen spielt dabei eine essentielle Rolle um verschiedenste Qualitätsmerkmale und Anforderungen zu erfüllen, die u.a. in Gesetzen, Normen und Richtlinien festgelegt sind. Die regelmäßige Korngrößenbestimmung in den einzelnen Teilprozessen des Aufbereitungsprozesses eines Rohstoffes nimmt eine entscheidende Stellung für die Prozesseffizienz und insbesondere für die abschließende Qualität und Beschaffenheit des Rohstoffes ein. Die Erfassung des Kornspektrums der Rohstoffe erfolgt vor bzw. nach jedem Prozessschritt fast ausschließlich durch die sporadische und hauptsächlich manuelle Entnahme von Proben und deren Analyse im Labor mittels gängiger Siebmaschinen. Diese Form der Analyse ist daher sehr zeitintensiv, sodass die Analyse-Ergebnisse stets zeitversetzt zu den kontinuierlich weiterlaufenden Prozessen zur Verfügung stehen. Ein zeitnahes aktives Eingreifen in das System zur Qualitätsverbesserung und Maschinensteuerung ist aktuell nicht möglich. Ein online arbeitendes System zur Korngrößenanalyse würde sowohl zur Prozess- und Produktoptimierung, als auch zu Kostensenkungen bei den Aufbereitungsprozessen führen. Gegenstand dieser Dissertation sind Untersuchungen zur Anwendung und Optimierung eines passiv akustischen Verfahrens zur Korngrößenanalyse in der Steine- und Erdenindustrie. Die Untersuchungen beziehen sich dabei auf die verschiedenen Faktoren, die Einfluss auf das Messsystem haben. Dabei werden die Einflussgrößen untersucht und es erfolgt eine Optimierung der jeweiligen Einheiten der Messvorrichtung. Im Rahmen der Untersuchungen wurden insbesondere die Genauigkeit und die Reproduzierbarkeit der Ergebnisse unter besonderer Berücksichtigung der Integration der Messvorrichtung in die Aufbereitungsprozesse der Steine- und Erdenindustrie bewertet. Dafür wurden Prototypen entwickelt, welche über mehrere Monate in verschiedenen Gesteinsbetrieben unter betrieblichen Voraussetzungen einem Langzeittest unterzogen wurden. Die Ergebnisse bestätigten die Richtigkeit der Arbeitshypothese. Die Nutzung der Signale, die bei der Kollision von Körnungen mit einem Oszillator entstehen, ermöglicht die Messung des Korngrößenspektrums und der Korngrößenverteilung der Granulate in einem Massenstrom. Ein Einsatz für die qualitative Korngrößenerfassung der Granulate sowie die Überwachung von Steine- und Erdenprodukten ist auf Basis der Erkenntnisse möglich.Due to the expansion of new technologies and due to rising living standards, especially in emerging economies, the global demand for mineral resources has continued to increase over the past decades [1]. In order to meet the constant demand, mineral raw materials with a total value of between USD 600 and 900 billion are extracted annually by mining operations worldwide (USD 687 billion in total in 2017) [2]. After extraction, these raw materials are processed in various processes. The goal of raw material processing is to condition the raw materials for various industrial uses. The analysis of particle size distributions plays an essential role in order to meet various quality characteristics and requirements, which are specified in laws, standards and guidelines, among others. The regular grain size determination in the individual sub-processes of the preparation process of a raw material takes a decisive position for the process efficiency and especially for the final quality and condition of the raw material. The grain spectrum of the raw materials is recorded before or after each process step almost exclusively by the sporadic and mainly manual taking of samples and their analysis in the laboratory by means of common screening machines. This form of analysis is therefore very time-consuming, so that the analysis results are always available with a time delay to the continuously running processes. It is currently not possible to actively intervene in the system for quality improvement and machine control. An online system for particle size analysis would lead to process and product optimization as well as to cost reductions in the treatment processes. The subject of this dissertation are investigations on the application and optimization of a passive acoustic method for particle size analysis in the stone and earth industry. The investigations relate to the various factors that have an influence on the measurement system. The influencing variables are investigated and the respective units of the measuring device are optimized. Within the scope of the investigations, the accuracy and the reproducibility of the results were evaluated in particular with special consideration of the integration of the measuring device into the preparation processes of the stone and earth industry. For this purpose, prototypes were developed which were subjected to a long-term test over several months in various rock processing plants under operational conditions. The results confirmed the correctness of the working hypothesis. The use of the signals generated by the collision of granules with an oscillator allows the measurement of the granule size spectrum and the granule size distribution in a mass flow. An application for the qualitative grain size measurement of the granules as well as the monitoring of stone and earth products is possible on the basis of the findings

Elemental Abundances of Nearby Galaxies through High Signal-to-Noise XMM-Newton Observations of ULXs

(abridged) In this paper, we examined XMM Newton EPIC spectra of 14 ultra-luminous X-ray sources (ULXs)in addition to the XMM RGS spectra of two sources (Holmberg II X-1 and Holmberg IX X-1). We determined oxygen and iron abundances of the host galaxy's interstellar medium (ISM) using K-shell (O) and L-shell (Fe) X-ray photo-ionization edges towards these ULXs. We found that the oxygen abundances closely matched recent solar abundances for all of our sources, implying that ULXs live in similar local environments despite the wide range of galaxy host properties. Also, we compare the X-ray hydrogen column densities (n_H) for 8 ULX sources with column densities obtained from radio H I observations. The X-ray model n_H values are in good agreement with the H I n_H values, implying that the hydrogen absorption towards the ULXs is not local to the source (with the exception of the source M81 XMM1). In order to obtain the column density and abundance values, we fit the X-ray spectra of the ULXs with a combined power law and one of several accretion disk models. We tested the abundances obtained from the XSPEC models bbody, diskbb, grad, and diskpn along with a power law, finding that the abundances were independent of the thermal model used. We comment on the physical implications of these different model fits. We also note that very deep observations allow a breaking of the degeneracy noted by Stobbart et al. (2006) favoring a high mass solution for the absorbed grad + power law model.Comment: 18 pages, accepted to Ap

XMM-Newton Archival Study of the ULX Population in Nearby Galaxies

We present the results of an archival XMM-Newton study of the bright X-ray point sources (L_X > 10^38 erg/s) in 32 nearby galaxies. From our list of approximately 100 point sources, we attempt to determine if there is a low-state counterpart to the Ultraluminous X-ray (ULX) population, searching for a soft-hard state dichotomy similar to that known for Galactic X-ray binaries and testing the specific predictions of the IMBH hypothesis. To this end, we searched for "low-state" objects, which we defined as objects within our sample which had a spectrum well fit by a simple absorbed power law, and "high-state" objects, which we defined as objects better fit by a combined blackbody and a power law. Assuming that ``low-state'' objects accrete at approximately 10% of the Eddington luminosity (Done & Gierlinski 2003) and that "high-state" objects accrete near the Eddington luminosity we further divided our sample of sources into low and high state ULX sources. We classify 16 sources as low-state ULXs and 26 objects as high-state ULXs. As in Galactic black hole systems, the spectral indices, Gamma, of the low-state objects, as well as the luminosities, tend to be lower than those of the high-state objects. The observed range of blackbody temperatures for the high state is 0.1-1 keV, with the most luminous systems tending toward the lowest temperatures. We therefore divide our high-state ULXs into candidate IMBHs (with blackbody temperatures of approximately 0.1 keV) and candidate stellar mass BHs (with blackbody temperatures of approximately 1.0 keV). A subset of the candidate stellar mass BHs have spectra that are well-fit by a Comptonization model, a property similar of Galactic BHs radiating in the "very-high" state near the Eddington limit.Comment: 54 pages, submitted to ApJ (March 2005), accepted (May 2006); changes to organization of pape

Statistical Evaluation of Monophyly in the ‘Broad-Nosed Weevils’ through Molecular Phylogenetic Analysis Combining Mitochondrial Genome and Single-Locus Sequences (Curculionidae: Entiminae, Cyclominae, and Hyperinae)

Establishing well-supported monophyletic groups is a key requirement for producing a natural classification that reflects evolutionary descent. In a phylogenetic framework this is best achieved through dense taxon sampling and the analysis of a robust character dataset, combined with statistical testing of topological hypotheses. This study assesses the monophyly of tribes and subfamilies within the diverse ‘broad-nosed weevils’ (Curculionidae: Entiminae, Cyclominae and Hyperinae) through analysis of single-locus sequence data for mitochondrial cox1 and rrnL genes, in combination with a ‘backbone’ of complete and near-complete mitochondrial genome sequences. Maximum likelihood phylogenetic analyses incorporating topological constraints for various higher-taxa were statistically tested using the AU, SH, and KH tests, which indicated that three tribes within Entiminae, as presently classified, are not monophyletic. Moderate and high bootstrap support was also consistent with two entimine tribes (Peritelini and Cylydrorhinini) being each recovered as monophyletic in an unconstrained analysis. Furthermore, one genus of cyclomine weevils (Aphela) is recovered outside the clade of ‘broad-nosed weevils’, although its taxonomic placement remains uncertain. It is apparent that the present approach may be hampered by limited taxon sampling in the ‘backbone’ dataset, rendering it difficult for divergent taxa to robustly match to their closest lineages. However, with improved taxon sampling of the mitogenome tree, the general approach can be a useful taxonomic tool for weevils

A Search for Extraplanar Dust in Nearby Edge-On Spirals

We present high resolution BV images of 12 edge-on spiral galaxies observed with the WIYN 3.5-m telescope. These images were obtained to search for extraplanar (|z| > 0.4 kpc) absorbing dust structures similar to those previously found in NGC 891 (Howk & Savage 1997). Our imaged galaxies include a sample of seven massive L_*-like spiral galaxies within D<25 Mpc that have inclinations i > 87 deg from the plane of the sky. We find that five of these seven systems show extraplanar dust, visible as highly-structured absorbing clouds against the background stellar light of the galaxies. The more prominent structures are estimated to have associated gas masses >10^5 M_sun; the implied potential energies are > 10^(52) ergs. All of the galaxies in our sample that show detectable halpha emission at large z also show extraplanar dust structures. None of those galaxies for which extraplanar halpha searches were negative show evidence for extensive high-z dust. The existence of extraplanar dust is a common property of massive spiral galaxies. We discuss several mechanisms for shaping the observed dust features, emphasizing the possibility that these dusty clouds represent the dense phase of a multiphase medium at high-z in spiral galaxies. The correlation between high-z dust and extraplanar Halpha emission may simply suggest that both trace the high-z interstellar medium in its various forms (or phases), the existence of which may ultimately be driven by vigorous star formation in the underlying disk. (Abstract abridged)Comment: 26 pages; 15 jpeg figures. To appear in The Astronomical Journal, May 1999. Gzipped tar files of high-resolution figures in postscript and jpeg formats are available at http://www.astro.wisc.edu/~howk/Papers/papers.html#surve

A deep X-ray observation of NGC 4258 and its surrounding field

We present a deep X-ray observation of the low-luminosity active galactic nucleus in NGC4258 (M106) using ASCA. The soft X-ray spectrum <2keV is dominated by thermal emission from optically-thin plasma with kT~0.5keV. The hard X-ray emission is clearly due to a power-law component with photon index Gamma=1.8 absorbed by a column density of N_H=8x10^22/cm^2. The power-law is readily identified with primary X-ray emission from the AGN central engine. We also clearly detect a narrow iron K-alpha emission line at 6.4keV. No broad component is detected. We suggest that the bulk of this narrow line comes from the accretion disk and, furthermore, that the power-law X-ray source which excites this line emission (which is typically identified with a disk corona) must be at least 100GM/c^2 in extent. This is in stark contrast to many higher-luminosity Seyfert galaxies which display a broad iron line indicating a small 10 GM/c^2 X-ray emitting region. It must be stressed that this study constrains the size of the X-ray emitting corona rather than the presence/absence of a radiatively efficient accretion disk in the innermost regions. If, instead, a substantial fraction of the observed narrow line originates from material not associated with the accretion disk, limits can be placed on the parameter space of possible allowed relativistically broad iron lines. By comparing our data with previous ASCA observations, we find marginal evidence for a change in absorbing column density through to the central engine, and good evidence for a change in the AGN flux.Comment: 11 pages, 9 postscript figures. Accepted for publication in Ap

Enhanced efficacy and increased long-term toxicity of CNS-directed, AAV-based combination therapy for Krabbe disease

Infantile globoid cell leukodystrophy (GLD, Krabbe disease) is a demyelinating disease caused by the deficiency of the lysosomal enzyme galactosylceramidase (GALC) and the progressive accumulation of the toxic metabolite psychosine. We showed previously that central nervous system (CNS)-directed, adeno-associated virus (AAV)2/5-mediated gene therapy synergized with bone marrow transplantation and substrate reduction therapy (SRT) to greatly increase therapeutic efficacy in the murine model of Krabbe disease (Twitcher). However, motor deficits remained largely refractory to treatment. In the current study, we replaced AAV2/5 with an AAV2/9 vector. This single change significantly improved several endpoints primarily associated with motor function. However, nearly all (14/16) of the combination-treated Twitcher mice and all (19/19) of the combination-treated wild-type mice developed hepatocellular carcinoma (HCC). 10 out of 10 tumors analyzed had AAV integrations within the Rian locus. Several animals had additional integrations within or near genes that regulate cell growth or death, are known or potential tumor suppressors, or are associated with poor prognosis in human HCC. Finally, the substrate reduction drug L-cycloserine significantly decreased the level of the pro-apoptotic ceramide 18:0. These data demonstrate the value of AAV-based combination therapy for Krabbe disease. However, they also suggest that other therapies or co-morbidities must be taken into account before AAV-mediated gene therapy is considered for human therapeutic trials

Probing the accretion disk and central engine structure of NGC4258 with Suzaku and XMM-Newton observations

[abridged] We present an X-ray study of the low-luminosity active galactic nucleus (AGN) in NGC4258 using data from Suzaku, XMM-Newton, and the Swift/BAT survey. We find that signatures of X-ray reprocessing by cold gas are very weak in the spectrum of this Seyfert-2 galaxy; a weak, narrow fluorescent-Kalpha emission line of cold iron is robustly detected in both the Suzaku and XMM-Newton spectra but at a level much below that of most other Seyfert-2 galaxies. We conclude that the circumnuclear environment of this AGN is very "clean" and lacks the Compton-thick obscuring torus of unified Seyfert schemes. From the narrowness of the iron line, together with evidence for line flux variability between the Suzaku and XMM-Newton observations, we constrain the line emitting region to be between $3\times 10^3r_g$ and $4\times 10^4r_g$ from the black hole. We show that the observed properties of the iron line can be explained if the line originates from the surface layers of a warped accretion disk. In particular, we present explicit calculations of the expected iron line from a disk warped by Lens-Thirring precession from a misaligned central black hole. Finally, the Suzaku data reveal clear evidence for large amplitude 2-10keV variability on timescales of 50ksec as well as smaller amplitude flares on timescales as short as 5-10ksec. If associated with accretion disk processes, such rapid variability requires an origin in the innermost regions of the disk ($r\approx 10r_g$ or less).Comment: 10 pages, 6 figures. Accepted for publication in the Astrophysical Journa

Who Rpinted Shakespeare’s Fourth Folio?

According to Fredson Bowers, writing in Shakespeare Quarterly in 1951, we will never know the printer of that section "until we know everything there is to be learned about seventeenth-century types." 2 Bowers doubted we could ever list the full set of F4's printers because F4 was printed anonymously, and the volume left few clues about its printers. While George Watson Cole's 1909 "examination of the letterpress show[ed] that a copy of the Third Folio was apparently broken into three portions and sent to three different printers," Bowers himself only got as far as attributing the first of F4's three separately paginated parts. 3 The purpose of this note is to identify the other two printers involved in F4, one of whom, John Macock, was the printer whose shop was responsible for F4's Hamlet. Regrettably, this short note does not include everything there is to be learned about seventeenth-century types.

Creating bulk nanocrystalline metal.

Nanocrystalline and nanostructured materials offer unique microstructure-dependent properties that are superior to coarse-grained materials. These materials have been shown to have very high hardness, strength, and wear resistance. However, most current methods of producing nanostructured materials in weapons-relevant materials create powdered metal that must be consolidated into bulk form to be useful. Conventional consolidation methods are not appropriate due to the need to maintain the nanocrystalline structure. This research investigated new ways of creating nanocrystalline material, new methods of consolidating nanocrystalline material, and an analysis of these different methods of creation and consolidation to evaluate their applicability to mesoscale weapons applications where part features are often under 100 {micro}m wide and the material's microstructure must be very small to give homogeneous properties across the feature