306,929 research outputs found
Geologische Specialkarte von Preussen und den Thüringischen Staaten / 5747 Lützen
No full textgeognostisch bearbeitet durch L. Siegert ; herausgegeben von der Kgl. Preuss. Geolog. Landesanstal
Geologische Specialkarte von Preussen und den Thüringischen Staaten / 5741 Merseburg (Ost)
No full textgeognostisch bearbeitet durch L. Siegert u. R. Bärtling ; herausgegeben von der Kgl. Preuss. Geolog. Landesanstal
[Ansicht des Aetna und der umliegenden Gegend] : etwas zur Erläuterung des Panorama vom Aetna-Gebirge
No full text[Erläuterung von Franz Lehner] ; [Tafel gemalt von Prof. Siegert]Exlibrisprägestempel: "Immanuel Friedlaender" 002331333_0002 Exemplar der ETH-BIBIndirektes handschriftliches Exlibris: "1936, 633", das ist "Immanuel Friedlaender" 002330334_0002 Exemplar der ETH-BIBGeschenkexlibris-Etikette: "Schenkung des Vulkaninstituts Immanuel Friedländer" 002331333_0001 Exemplar der ETH-BI
Sämmtliche Singspiele
No full text> schöne Schusterinn > glücklichen Jäger > Apotheker und der Doktor > Liebe im Narrenhause > SchauspieldirektorMusik von Umlauf, Musik von Dittersdorf, Musik von MozartUmlaute in der Vorlage mit übergestelltem "e"Vorlageform der Veröffentlichungsangabe: Liegnitz, bey David Siegert, 1792.Text deutsch In Fraktu
Optimization of Bloch-Siegert B1 Mapping Sequence for Maximum Signal to Noise
No full textAdiabatic Bloch-Siegert B1+ mapping method addresses the long TE and high RF power deposition problems of conventional Bloch-Siegert B1+ mapping by introducing short frequency-swept ABS pulses with maximum sensitivity. Here, it is shown how maximum signal to noise ratio can be achieved in adiabatic Bloch-Siegert B1+ mapping. Signal to noise ratio of B1+ maps is maximized by optimizing the adiabatic pulse parameters such as width, amplitude and shape of the Bloch-Siegert pulse within a specified scan time and under approved SAR guidelines. Equations for optimized Bloch-Siegert pulse parameters are derived, which are dependent on the base pulse sequence used for B1+ mapping as well as tissue properties and transmit coil configuration. It is shown that by this optimization it is more efficient to increase TR rather than using the averaging method to increase signal to noise ratio
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Depressive symptoms in an ethnically Diverse cohort of chronic dialysis patients: The role of patient characteristics, cultural and inflammatory factors
No full textHonig, A. [Promotor]Dekker, F.W. [Promotor]Siegert, C.E.H. [Copromotor
A revised inventory of Antarctic subglacial lakes
No full textThe locations and details of 145 Antarctic subglacial lakes are presented. The inventory is based on a former catalogue of lake-type features, which has been subsequently reanalysed, and on the results from three additional datasets. The first is from Italian radio-echo sounding (RES) of the Dome C region of East Antarctica, from which 14 new lakes are identified. These data also show that, in a number of occasions, multiple lake-type reflectors thought previously to be individual lakes are in fact reflections from the same relatively large lake. This reduces the former total of lake-type reflectors by six, but also adds a significant level of information to these particular lakes. The second dataset is from a Russian survey of the Dome A and Dome F regions of East Antarctica, which provides evidence of 18 new lakes and extends the coverage of the inventory considerably. The third dataset comprises three airborne RES surveys undertaken by the US in East Antarctica over the last five years, from which forty three new lakes have been identified. Reference to information on Lake Vostok, from Italian and US surveys taken in the last few years, is now included
Quantum theory of reactive scattering in phase space
No full textWe review recent results on quantum reactive scattering from a phase space perspective. The approach uses classical and quantum versions of normal form theory and the perspective of dynamical systems theory. Over the past ten years the classical normal form theory has provided a method for realizing the phase space structures that are responsible for determining reactions in high dimensional Hamiltonian systems. This has led to the understanding that a new (to reaction dynamics) type of phase space structure, a normally hyperbolic invariant manifold (or NHIM)(or, NHIM) is the "anchor" on which the phase space structures governing reaction dynamics are built. The quantum normal form theory provides a method for quantizing these phase space structures through the use of the Weyl quantization procedure. We show that this approach provides a solution of the time-independent Schrödinger equation leading to a (local) S-matrix in a neighborhood of the saddle point governing the reaction. It follows easily that the quantization of the directional flux through the dividing surface with the properties noted above is a flux operator that can be expressed in a "closed form". Moreover, from the local S-matrix we easily obtain an expression for the cumulative reactio probability (CRP). Significantly, the expression for the CRP can be evaluated without the need to compute classical trajectories. The quantization of the NHIM is shown to lead to the activated complex, and the lifetimes of quantum states initialized on the NHIM correspond to the Gamov-Siegert resonances. We apply these results to the collinear nitrogen exchange reaction and a three degree-of-freedom system corresponding to an Eckart barrier coupled to two Morse oscillators
Anaerobic digestion of solid wastes : fundamental studies on the factors governing microbial hydrolysis reactions
No full textThe effect of different physical-chemical conditions on the anaerobic digestion of paper with low lignin content was studied. Experiments were conducted at the one-liter and five-liter scale, and included both batch and semi-continuous digestion. The conditions tested were microbial and substrate conditions, pH, nutrients content, particle size, temperature and volatile intermediates concentrations. Emphasis was placed on the first step, cellulose hydrolysis, by measuring the enzymatic activity of the hydrolytic bacteria under the conditions applied. Different inoculum and substrate concentrations were tested with 40% inoculum and 14.8g cellulose.1-1 showing to be necessary to achieve efficient cellulose digestion and an appropriate process for the study of the other conditions in batch mode. An improvement in cellulose digestion was observed in semi-continuous systems when gradually increasing the solids loading during the acclimatisation period. The use of dilution medium compared to tap water showed a higher cellulose removal and cellulolytic activity, and more pH stability providing more buffering capacity. Various pH and temperatures were tested with optimums found to be 7 and 35≡C, respectively. In the pH and temperature range tested, more cellulolytic activity and cellulose digestion was obtained at slightly lower pH and temperature. An inverse relationship was obtained between the cellulolytic activity and the size of the paper particles, once the paper has been partially hydrolysed, enzymatic activity proceeds at similar levels. In general, the rate of hydrolysis/acidogenesis was higher than the production of biogas, leading to the rapid accumulation of volatile fatty acids even at optimum conditions, and therefore, the inhibition of methanogenesis. The effect of volatile fatty acids was also studied on cellulose hydrolysis, in batch and semi-continuous systems, by using a synthetic mixture. A decrease of the cellulolytic activity was observed from 2,000mg VFA.1-1 added with the effect being more severe in batch systems compared with the semi-continuous tests. The decrease in cellulose hydrolysis observed in single-phase reactors due to the accumulation of volatile intermediates was alleviated by means of a hydraulic flush carried out to obtain a liquid retention time of 2 days. The removal of VFAs from the system produced a stimulation of the cellulolytic activity, improving the rate of cellulose removal.</p
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