[en] The self-assembly behaviour of colloidal and patchy particles, i.e., colloids with localized surface functionalizations, is central to a rapidly growing field of researchin chemistry and physics. Over the last three decades, the surge of attention towards syntheses of these particles is explained by the manifold existing and future technological applications of materials with nano- and micrometre-sizedstructures.In computational and theoretical models, hardcore particles have a long history,dating back to the 1950s, when computers started to become an indispensable tool in statistical physics. The patchy particle model was invented in the 1980s for a theoretical description of associated liquids. Nowadays, the explanation of colloidal and patchy particles’ self-assembly using modelling and simulationsto compute phase behaviour can serve as a predecessor for directing efforts inreal-life implementations.In this PhD-Thesis, I present two research projects, both focusing on ensembles of elliptic particles using Monte Carlo simulations.In the first project, which is presented in Part II of this thesis, different lattice configurations formed by hardcore elliptic particles are investigated. There are infinitely many possible lattice configurations for these types of particles. My investigations provide an answer to the question of which one of these lattices is the entropically most favourable one. I present an in-depth analysis of a possible lattice parameterization as well as the search for two lattice candidates, namely the parallel and diagonal lattices, for the following free energy computations. By the use of finite-size corrections, I show that the parallel lattice is entropically more favourable than the diagonal lattice state.In the second project, presented in Part III, the self-assembly scenarios of hard-core elliptic particles decorated with attractive short-range patches are investigated. By imitating the adsorption process of particles into assembled structures on a surface using grand-canonical Monte Carlo simulations, I characterize various such assemblies, ranging from porous networks to chains. Structural properties, as well as some dynamic effects, are described.Part I of this thesis collects the description of all methods used through out there search projects presented in Part II and Part III. (author)

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[en] It has long been known that a precise measurement of the SLC beam trajectory through the IP region is vital both from a machine and a detector point of view. One of the primary techniques used to maximize luminosity is the measurement of the deflection angle of one beam produced by the electromagnetic interaction with the other beam. In order to implement this procedure a pair of precision Beam Position Monitors (BPMs) were installed within the Final Triplet of quadrapoles on each side of the IP. Before the IP BPMs could be used to measure beam-beam deflection, a series of measurements were made of the coefficients which relate the setting of an orbit correction magnet to the position of the beam at a particular BPM (R₁₂s). The purpose was to expose any problems such as misconnected cables, etc., by comparing the measured R₁₂s with theoretical predictions from the model of the Final Focus region. A technique developed that uses position measurements in the long BPMs to determine a three parameter fit to the beam trajectory at the IP. The three parameters in the fit are the beam position, the incoming angle and the deflection angle. The result was very successful and allows the observation of beam-beam deflection even under marginal conditions. The purpose of this memo is to clear up the technical points and to demonstrate that the simplicity of the fit should allow the implementation of this procedure at the micro level, where it could provide trajectory information in real time which would go a long way toward making it useful as a fast feedback tool and in addition allow easy real time access to beam position data by the Mark II

[en] The 15th General Conference on Weights and Measures (1975) decided to introduce the name Becquerel for the SI unit of the quantity activity (1 Bq = 1 s^-1) and the name Gray for the SI unit of ionizing radiations (1 Gy = 1 J/kg). The consequences of this latter decision are discussed. The Bundesanstalt is of the opinion that no further names for this unit should be introduced, but that the Gray should be used also for other quantities of the same dimension, especially for the dose equivalent. (orig.)

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[en] In this paper we discuss methods used to measure heavy quark asymmetries at PEP and PETRA and their application to our future SLC data. The results given are from talks by Jim Smith at Asilomar and Steve Wagner at Granlibakken. The tagging of e⁺e^- → Z⁰ → c ant c events is done with D/sup *+/ mesons selected with the Dm technique. This method has been tested with good results with the Mark II Upgrade PEP data. Since this analysis is already fully documented, a detailed description of the D/sup *+/ selection procedure and the associated plots is omitted from this paper. Studies of the familiar techniques of tagging e⁺e^- → Z⁰ → b ant b events with high pt leptons are discussed. An alternative technique for measuring the b quark asymmetry with vertex tagging and the determination of the quark charge from the jet charge is also described. We estimate the expected statistical precision of the above measurements for a sample of 10⁶ Z⁰ events collected with the Mark II detector at the SLC

[en] Exercise thallium myocardial scintigrams were analyzed in 76 consecutive patients with documented normal coronary arteries to identify the factors associated with abnormal or ''false positive'' studies. The thallium scintigrams had been judged normal in 60 patients (79 percent) and abnormal in 16 (21 percent). Analysis of the location of thallium defects in the 16 patients with abnormal scintigrams revealed a pattern that was consistent with coronary artery disease in 5, including 4 with an abnormal left ventricle, and a pattern that was inconsistent in the other 11. In 9 of these 11 patients the pattern of defects suggested soft tissue attenuation, by the diaphragm in 2 and breast or adipose tissue in 7, whereas in the other 2 patients isolated apical defects were seen. Among exercise myocardial scintigrams performed in 68 randomly selected patients with abnormal coronary arteries, 6 (9 percent) were reported to be normal. In four patients with abnormal scintigrams, the diagnosis of coronary artery disease was based on an inconsistent pattern. In three of these the pattern was related to isolated apical defects and in one it was related to apparent soft tissue attenuation. ''Consistent'' scintigraphic defects, seen frequently in patients with normal coronary arteries, in whom they are usually associated with an abnormal left ventricle. In patients with normal coronary arteries, ''inconsistent'' thallium defects are probably related to soft tissue attenuation or to normal apical thinning. Although defects caused by isolated apical abnormalities and soft tissue attenuation are also seen in patients with coronary diseases and add somewhat to scintigraphic sensitivity, they are a rare cause of diagnostic scintigraphic abnormalities in patients with coronary disease. The incidence of false positive thallium scintigrams could be reduced and overall accuracy improved by careful attention to the pattern of thallium defects

[en] Misunderstandings of the conceptual difference between physical quantities on the one hand and their units on the other hand have for a long time delayed the formation of clear concepts for dosimetry and the rigid definition of physical quantities, thus masking the causal sequence from radiation source over radiation field to radiation effect. The physical quantities characterizing each stage are given with reference to the correlations between them. It is shown that dose quantities (exposure, absorbed dose, dose equivalent) serve best the aims of radiation protection work. Special consideration is given to the case of neutron radiation which is cimplicated by the necessary introduction of quality factors. The relation between neutron fluence and maximum dose equivalent in an irradiated body might suggest the determination of field quantities instead of dose quantities. But this can only be a practical advantage if additional information on the spectral distribution of neutrons is available. In view of the fact that radiation protection guides are given in terms of dose equivalent and that photon radiation is generally the predominant hazard and mostly presents the main contribution in mixed radiation fields, the common base for the assessment of radiation hazard should remain in dose quantities. (orig.)