Introduction: Phospholipids amphiphilic structure gives them special properties such as self-aggregation, emulsifying and wetting properties. Among the various structures resulting from the dissolution of phospholipids in water are the liposome, which acts as a drug carrier. They also act as surfactants for wetting by adsorbing on the crystal surface to increase the hydrophilicity of hydrophobic drugs. Surfactants, such as bile salts, have been shown to have a good ability to solubilize and dissolve non-polar lipids. By mixing with bile salts, phospholipids can easily dissolve and form mixed micelles. For the breakdown of fats in the gastrointestinal tract, mixed micelles formed from bile salts and phospholipid play an important role as well as in solubilizing water-insoluble drugs and other drug delivery applications. Aim: Theaim of this project is to study mixtures of the bile salts sodium deoxycholate (NaDC) and sodium cholate (NaC) with the anionic phospholipid DMPG and to determine the mole fraction (composition) in the aggregates at the transition from micelles to bicolts in bile salt / phospholipid mixtures. In addition, we want to determine the average size and structure of the colloidal particles formed in the solutions near the transition. The phospholipid DMPG has a charge and our results will be compared with previous corresponding studies where the zwitterionic phospholipid DMPC was investigated. Methods: The structure and size of micelles and bilayers formed will be determined by Dynamic Light Scattering (DLS) and Static Light Scattering (SLS) and Determination of refractive index increment of NaC and NaDC. Complementary techniques such as surface tension, small angle X-ray scattering (SAXS) and cryo-TEM may be used. Results and Discussion: This study was able to show that aggregates for systems with a molar ratio of 0.05 to 0.20 of both NaC and NaDC at 21 degrees (°C), have an approximate size range between 3 and 10 nm. At 21 ° C the concentration range studied for both NaC and NaDC shows that the particles are larger in size at lower concentrations. Also, increasing the molar ratio of both bile salts, NaC and NaDC in the samples leads to a reduction in the particle size of the system. At 37 °C the system shows a significant increase in the size of the particles for both the bile salts, NaC and NaDC in a size range between 10 and 400 nm. However, at 37 ° C and for both NaC and NaDC in molar ratios of 0.05 and 0.10, the particle size increases with increasing sample concentration but in molar ratios of 0.15 and 0.20, the particle size decreases with increasing sample concentration. At 21 ° C the light scattering experiments for the systems in NaDC and DMPC showed that the size of the micelles decreased with increasing concentrations while the increasing molar ratio led to increased size corresponding to mixed systems of bile salts and DMPG but not at 37 ° C. This difference may be mainly due to the fact that DMPG is an anionic phospholipid that has a charge and the altered conical shape of the bile salts as well as spontaneous curvature at a higher temperature. At 21 ° C the light scattering experiments for the systems in NaDC and DMPC showed that the size of the micelles decreased with increasing concentrations while the increasing molar ratio led to increased size corresponding to mixed systems of bile salts and DMPG but not at 37 ° C. This difference may be mainly due to the fact that DMPG is an anionic phospholipid that has a charge and the altered conical shape of the bile salts as well as spontaneous curvature at a higher temperature. Conclusion: At 37 °C for NaC and NaDC in molar ratios of 0.05 and 0.10 other cmc are obtained, indicating the presence of large structures in the system. Where these large worm-like or rod-like structures are formed by micelles. Accurate prediction of what structures may be present in the system requires more detailed and more appropriate research methods which in turn also need more time to achieve the result. Due to the project's time constraints, it became impossible to use these methods. This difference may be mainly due to the fact that DMPG is an anionic phospholipid that has a charge. The bile salts' end conformation form as well as spontaneous curvature at higher temperatures.

Enligt svenska provtagningsanvisningar bör patienter vila i sittande ställning i minst 15 minuter innan provtagningen sker för att optimera resultatet av analysen. Referensintervallen som existerar idag i Sverige för olika analyser är framtagna och baserade på prover som tagits efter att deltagarna vilat 15 minuter i sittande position innan provtagningen. I denna studie samlades venösa blodprover in från patienter och personal i Karlskoga lasarett. Statistiska beräkningar utfördes för att jämföra kalium- och natriumanalyser i plasma efter att deltagaren vilat 15 minuter gentemot att deltagaren tagit en promenad på cirka 50 meter, signifikansnivån bestämdes som 0,05. Analyserna mättes genom en indirekt potentiometrisk metod, ISE, på instrumentet Advia 1800 Chemistry. Resultatet visade att det finns en signifikant skillnad av att vila 15 minuter innan provtagningen äger rum för kalium- och natriumanalyser i plasma gentemot att inte vila. Trots att studien visar att det finns en signifikant skillnad av att patienter vilar 15 minuter innan provtagningen sker är skillnaden inte tillräckligt stor för att påverka resultatet på ett sätt som förändrar läkarbedömningen. Personal bör ändå följa provtagningsanvisningarna för att optimera trovärdigheten och resultatet av analysen. / Swedish sampling guidelines encourage patients to rest for 15 minutes in a sitting position before drawing blood in order to optimize the results of the analysis. The reference ranges that is used for different blood tests in Sweden are originally based on samples taken from participants that has been resting 15 minutes in a sitting position. In this study, venous blood samples were collected from patients and staff in Karlskoga hospital. Statistical calculations was performed in order to compare potassium- and sodiumanalyzes in plasma after resting 15 minutes and after a stroll of 50 meters. The significance level was set to 0,05. The analyzes were measured using an indirectly potentiometric method, ISE, on the instrument Advia 1800 Chemistry. The study found that there is a significant difference by resting 15 minutes in a sitting position before drawing blood in order to analyze potassium and sodium compared to not resting. The difference between resting for 15 minutes in a sitting position before sampling, and not resting, is not large enough to affect the medical assessment of the analysis. However, hospital staff should still follow the Swedish sampling guidelines in order to optimize the credibility of the analysis.

Introduktion: Förekomsten av neurodegenerativa sjukdomar ökar, där ibland amyotrofisk lateralskleros (ALS) vilket gör att behovet efter nya effektiva terapier växer. ALS är en progressiv sjukdom som kännetecknas utav en degeneration av de övre motorneuronen i motoriskt cortex och de nedre motorneuronen i hjärnstam och ryggmärg. Förlusten av motorneuron leder till muskelsvaghet och atrofi, vilket gör att patienten får svårigheter att gå, tala och svälja. När andningsmuskulaturen drabbas leder det till andningssvikt, den vanligaste dödsorsaken till följd av sjukdomen och majoriteten av de som drabbas överlever inte mer än tre år efter symtomdebut. Patogenesen vid sjukdomen är komplex, trots forskning som pågått i årtionden så har de patogena mekanismerna förblivit oklara. Den bristande kunskapen om sjukdomen och dess bakomliggande mekanismer återspeglas i antalet tillgängliga behandlingar. Två läkemedel finns godkända av Food and Drug Administration (FDA) för behandling av ALS, riluzol sedan 1995 och edaravone sedan 2016. Syfte: Syftet med litteraturstudien var att undersöka om AMX0035 – en oral formulering av de två aktiva substanserna natrium 4-fenylbutyrat och taurursodiol kan vara av betydelse i kampen mot ALS genom att jämföra dess effekt och säkerhet med riluzol, nuvarande standardpreparat hos patienter med sjukdomen. Metod: Litteratursökning gjordes på PubMed, där fyra artiklar valdes och analyserades. Två av artiklarna behandlade riluzol och två kombinationen av natrium 4-fenylbutyrat-taurursodiol. Resultat: Båda studierna om riluzol visade på en signifikant effekt av läkemedlet hos patienter med ALS jämfört med placebo, där studie ett visade en minskad mortalitet på 38,6% efter tolv månader och 19,4% efter 21 månaders behandling. Studie två visade en minskad mortalitet på 35% efter 18 månaders behandling med riluzol. Studie tre som studerade kombinationen natrium 4-fenylbutyrat-taurursodiol visade att förändringstakten på ALSFRS-R skalan minskade med 0,42 poäng mer/månad för placebo. Studie fyra som var en uppföljning av studie tre visade en ökad överlevnad på 44% bland de som ursprungligen behandlats med natrium 4-fenylbutyrat i kombination med taurursodiol jämfört med dem som hade randomiserats till placebo. Slutsats: Natrium 4-fenylbutyrat i kombination med taurursodiol kan vara ett alternativ eller en tilläggsbehandling till riluzol hos patienter med ALS, då studierna som analyserades visade på positiva resultat. Behandlingen tolererades väl av deltagarna, där ingen biverkan tycks överväga effekten av behandling. Det behövs mer omfattande studier för att bekräfta effekten och säkerheten av natrium 4-fenylbutyrat-taurursodiol i en större och bredare patientgrupp. / The incidence of neurodegenerative diseases is increasing, which means that the need for new effective therapies is growing. Amyotrophic lateral sclerosis (ALS) is a progressive disease characterized by a loss of upper and lower motor neurons, the nerve cells that control the body’s skeletal muscles. A loss of motor neurons leads to muscle weakness and atrophy, which makes it difficult for the patient to walk, speak and swallow. When the respiratory muscles are affected, respiratory failure will occur, which is the most common cause of death due to the disease. The median survival time of a patient affected by the disease is approximately three years after the onset of symptoms. A high degree of variation occurs in patients who suffer from ALS in terms of which body region is affected and the rate of progression of the disease. The pathogenesis of the disease is complex: despite intensive research that has been going on for decades the pathogenic mechanisms still remain unclear. Probably several biochemical and regulatory pathways are involved, which interact with each other and eventually lead to selective cell death or apoptosis. Over a hundred different genes have been identified associated with ALS, however, it has been challenging to find the causal relationship between these genes and disease progression. The lack of knowledge about the disease and its underlying mechanisms is reflected in the low number of treatments available. Two drugs only, are approved by the Food and Drug Administration (FDA) for the treatment of ALS, riluzole since 1995 and edaravone since 2016.  The purpose of this literature study was to investigate whether sodium 4-phenylbutyrate in combination with taurursodiol may be a possible alternative to treatment with riluzole, the current standard drug for patients with ALS. Four clinical trials were analysed, two of the studies evaluated the efficacy of riluzole and two of the combination of sodium 4-phenylbutyrate and taurursodiol.  Both studies on riluzole showed a significant effect of the drug in patients with ALS compared with placebo, where study one showed a reduced mortality of 38,6% after 12 months and 19,4% after 21 months treatment, respectively. Study two showed a 35% reduction in mortality after 18 months of treatment with riluzole. Study three, which studied the combination of sodium 4-phenylbutyrate-taurursodiol, showed that the rate of change on the ALSFRS-R scale, a scale that serves as a measure of disability where a higher score means better function, decreased by 0,42 points more/month for placebo compared to sodium 4-phenylbutyrate-taurursodiol. Study four, which was an extension of study three, showed a 44% increase in survival among those initially treated with sodium 4-phenylbutyrate in combination with taurursodiol compared to those previously randomized to placebo.  Sodium 4-phenylbutyrate-taurursodiol may be an alternative or adjunctive therapy to riluzole in patients with ALS, as the studies analysed showed positive results. The treatment was well tolerated by the participants, where no side effect seems to consider the effect of treatment. Larger and longer studies are needed to confirm the effect and safety of the treatment.

The 22Ne(p,γ)23Na reaction belongs to the catalytic neon-sodium cycle and has an important role in the explosive hydrogen burning. The neon-sodium cycle takes place at temperatures of T = 0:1 - 0:5GK and is assumed to occur in di erent astrophysical systems: e.g. in novae, in super novae of type Ia and during the shell-burning of red giant branch stars. The implications of 22Ne(p,γ)23Na and the neon-sodium cycle in a nova scenario have been studied by using the nuclear network code libnucnet at GSI in Darmstadt. A nova is an outburst of matter in a binary system consisting of a white dwarf and a red giant star. It is therefore a representative phenomenon for explosive hydrogen burning. For the calculation of the nucleosynthesis during the nova outburst, the code libnucnet requires the initial mass composition of the novae partners, the temperature and density pro les of the nova explosion and the thermonuclear reaction rates of the participating reactions. In the following, the code determined the ow and the nal atomic abundance in the neon-sodium cycle during the entire nova process. Additionally, the in uence of the temperature pro le of the novae outburst as well as the thermonuclear reaction rate of the 22Ne(p,γ)23Na reaction on the nal atomic abundance in the outburst has been studied. A characteristic measure for the reactions in astrophysical environments is the thermonuclear reaction rate. The reaction rate of 22Ne(p,γ)23Na has still strong uncertainties in the temperature range of T = 0:03-0:3 GK. These uncertainties are based on insu cient upper limits of the resonance strengths as well as the possible existence of tentative states that are populated in the energy range of Elabp = 30 - 300 keV. The research presented in this thesis is dedicated to the experimental study of the 22Ne(p,γ)23Na reaction for an improved determination of the thermonuclear reaction rate. Furthermore, the implications of 22Ne(p,γ)23Na and the neon-sodium-cycle in novae scenarios are discussed. The data taking has been performed at the Laboratori Nazionali del Gran Sasso, Italy. This laboratory provides the LUNA facility (Laboratory for Underground Nuclear Astrophysics) for the measurement of small reaction cross sections. The LUNA facility includes a 400 kV ion accelerator, a windowless gas target system and a HPGe-detector. Based on the measurements of the 22Ne(p,γ)23Na reaction at LUNA, upper limits for the strengths of ve isolated resonances in the energy range of Elabp = 150 - 340 keV have been determined. For the nuclear resonance at Elabres = 186 keV, a positive resonance strength has been measured for the rst time in literature.

In this work an epitaxial layer of Indium Phosphide (InP) has been grown on top of a silicon substrate using the Corrugated Epitaxial Lateral Overgrowth (CELOG) technique. The grown InP CELOG top layer typically has a poor surface roughness and planarity. Before this surface can be used for any processing it has to be smooth and planarized. For this purpose a two-step Chemical Mechanical Polishing (CMP) technique has been investigated and developed. In the first step commercially available Chemlox has been used to planarize the sample. In the second step Citric Acid (CA) and sodium hypochlorite (NaClO) has been mixed together to form abrasive-free polishing slurry. The second step has been developed to remove defects introduced by the first step. This surface is prepared to demonstrate that a photonic device such as a quantum well can be realized in a Photonic Integrated Circuit (PIC). A quantum well was grown on the polished CELOG InP/Si sample and measured with Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and Photoluminescence (PL). The roughness was improved with CMP from 33.2 nm to 12.4 nm. However the quantum well did not give any response in the PL measurements. / I detta arbete har ett epitaxiellt lager indiumfosfid (InP) blivit växt på ett kiselsubstrat med hjälp av en korrugerad epitaxial lateral överväxt (CELOG) teknik. Det översta lagret av den CELOG växta ytan har ofta en väldigt ojämn yta. Innan denna yta kan användas till någon fortsatt utveckling måste den vara slät och plan. Det översta lagret har polerats med hjälp av en två-stegs kemisk mekanisk polerings (CMP) teknik. I det första steget har komersiellt tillgänglig Chemlox använts för att planarisera ytan. I det andra steget har citronsyra (CA) och natrium hypoklorit (NaClO) blandats samman för att bilda ett partikelfritt polermedel. Det andra steget har tagits fram för att ta bort defekter introducerade I det första steget. Ytan är preparerad för att demonstrera att en fotonisk enhet, t.ex. en kvantbrunn kan realiseras I en fotonisk integrerad krets (PIC). En kvantbrunn växtes fram på det polerade CELOG InP/Si provet och mattes med hjälp av atomkraftsmikroskop (AFM), scanning electron mikroskopi (SEM), röntgendiffraktion (XRD) och fotoluminisens (PL). Ytojämnheten förbättrades med hjälp av CMP från 33.2 nm till 12.4 nm. Dock så gav ej kvantbrunnen någon respons I PL-mätningarna.

Die vorliegende Studie zeigt erstmals, dass eine erhöhte Ca2+-Empfindlichkeit der kardialen Myofilamente im Tiermodell einen selbstständigen Risikofaktor bei der Entstehung von Herzrhythmusstörungen darstellt. Dies konnte sowohl für chronische Erhöhung der Ca2+-Empfindlichkeit im Rahmen einer Familiären Hypertrophen Kardiomyopathie (FHK) als auch für eine akute Erhöhung mit Hilfe eines Ca2+-Sensitizers gezeigt werden. Die Ergebnisse der Arbeit bieten so eine mögliche Erklärung für plötzlichen Herztod bei bestimmten Patienten mit FHK. Sie schränken weiterhin den Einsatz von Ca2+-Sensitizern ein. Schließlich beleuchten sie einen bisher kaum untersuchten Aspekt in der Arrhythmogenese von Herzinsuffizienz und nach einem Myokard-Infarkt. Auf zellulärer Ebene findet sich ein veränderter Ca2+-Zyklus mit erniedrigten und verlangsamten Transienten. Diese Veränderungen sind wahrscheinlich eine direkte Konsequenz der erhöhten Bindungsaffinität für Ca2+. Die Myofilamente sind „klebriger“ für Ca2+, während der Systole wird mehr Ca2+ gebunden, während der Diastole hingegen dissoziiert es langsamer. Bei adrenerger Stimulation und schnellen Herzfrequenzen mit entsprechender Verkürzung der Diastole kommt es zu erhöhtem diastolischem [Ca2+]i und zu erhöhten Ca2+-Inhalt des Sarkoplasmatischen Retikulums. Der so veränderte Ca2+-Zyklus führt wahrscheinlich mit Hilfe des Na+/Ca2+-Austauschers zu Veränderungen der Repolarisation des Aktionspotentials. Bei schnellen Herzfrequenzen treten Aktionspotential-Verlängerung, Ca2+-abhängige Nachdepolarisationen und getriggerte Schläge auf. Auf Organ-Ebene findet sich eine verkürzte Refraktärzeit. Damit sind sowohl ein Trigger als auch ein arrhythmogenes Substrat für die beobachteten ventrikulären Arrhythmien gegeben. / The present study shows for the first time that increased Ca2+-sensitity of the cardiac myofilaments is an indepent mechanism in the development of cardiac arrhythmias. This could be shown both for chronically increased Ca2+-sensitity in Familial Hypertrophic Cardiomyopathy (FHC) and for acute drug-induced Ca2+-sensitization. The results provide an explanation for sudden cardiac death in certain patients with FHC. Moreover they limit the use of Ca2+-sensitizers. Furthermore they elucidate new aspects in the arrhythmogenesis of important aquired hearts diseases such as heart failure and myocardial infarction. On the cellular level the Ca2+-cycle is altered, Ca2+-transients show a smaller amplitude and slower rate of decay. These changes are probably a direct consequence of the increased Ca2+-puffering capacity. The myofilaments are “sticky” for Ca2+, durig systole more Ca2+ is bound while the dissociation during diastole is decelerated. With adrenergic stimulation and faster frequencies there is an increased diastolic [Ca2+]i and subsequently an Ca2+-overloading of the Sarcoplasmatic Reticulum. These changes in the Ca2+-cycle cause remodelling of the action potential repolarisation via the Na+-Ca2+-exchanger. At fast frequencies one finds action potential prolongation, Ca2+-dependent afterdepolarisations and triggered activity. On the organ level Ca+-sensitized hearts show a shortened refractory period. Thus there is both trigger and substrate for the observed ventricular arrhytrhmia.

Da die Arzneistoffpermeation durch okulare Gewebe einen entscheidenden Einfluss auf die Heilung vieler Augenleiden hat, wurde die in vitro-Permeation hydrophiler und lipophiler Arzneistoffe durch okulare Gewebe und Zellkulturen in dieser Arbeit untersucht. Die Dissertation befasst sich vorrangig mit der Permeation des hydrophilen Modellarzneistoffs Pilocarpinhydrochlorid (P-HCl) durch isolierte Schweinecornea (SC), Schweinesklera, Kaninchenkonjunktiva und corneale bzw. konjunktivale Kaninchenepithelzellkultur. Der Einfluss verschiedener Formulierungsparameter wie Benzalkoniumchlorid (BAC), Natriumedetat, pH-Wert und Tonizität auf die P-HCl-Permeation wurde untersucht. Dabei konnte eine gute Korrelation zwischen isolierten Geweben und Zellkulturen in Reaktion auf die Variation der Formulierungsparameter festgestellt werden. Unter den getesteten Parametern zeigte BAC den größten Enhancereffekt. Weiterhin wurden vergleichende Permeationsstudien an gelaserter SC mit P-HCl und dem relativ lipophilen Diclofenac-Natrium (D-Na) durchgeführt. Das Entfernen von Epithelschichten der SC mittels Excimer-Laser sollte den Heilungsverlauf, vor allem aber die zeitabhängige Reepithelisierung der Cornea nach erfolgter Photorefraktiver Keratektomie, simulieren. Die Ergebnisse dieser Studie zeigten, dass unterschiedliche Epitheldicken einen signifikanten Einfluss auf die P-HCl-Permeation haben. Im Gegensatz dazu blieb die D-Na-Permeation nahezu unbeeinflusst. Ein weiteres Anliegen dieser Arbeit bestand darin, eine okular applizierbare Formulierung des Immunsuppressivums Mycophenolatmofetil (MMF) zu entwickeln. Sowohl für das Prodrug MMF als auch für dessen aktiven Metaboliten Mycophenolsäure (MPA) wurde die Permeabilität von SC getestet. Ausgewählt wurde eine Zubereitung, die 1% MMF in Glutathion-Bicarbonat-Ringerlösung enthält und mit 10% Hydroxypropyl-beta-Cyclodextrin versetzt ist. Diese Suspension wurde bei 121° C und 200 kPa für 15 min autoklaviert, um das schwerlösliche MMF in Lösung zu bringen. Da der Ester MMF bei der Herstellung der Testlösung einer teilweisen Hydrolyse zu MPA unterliegt, außerdem eine minimale in vitro-Verfügbarkeit aufweist und sehr schwer wasserlöslich ist, sollte MPA in Augentropfenformulierungen der Vorzug gegeben werden. Die Korrelierbarkeit mit in vivo-Resultaten ist jedoch im Rahmen dieser Arbeit nicht untersucht worden, so dass die Ergebnisse als Grundlage für Permeationsstudien am in vivo-Modell zu bewerten sind. / The permeation of drugs through ocular tissues plays an important role in healing of various eye diseases. The objective of this work was to investigate the in vitro permeability of hydrophilic and lipophilic drugs through ocular tissues and cell cultures. Mainly, the permeability of the hydrophilic model drug pilocarpine hydrochloride (P-HCl) through isolated pig cornea (PCr) and sclera, rabbit conjunctiva, and rabbit conjunctival or corneal epithelial cell culture was compared. Additionally, the study included investigations about the influence of the formulation parameters benzalkonium chloride (BAC), ethylene diamine tetra acetic acid disodium salt, pH value and tonicity on the permeability of the small drug. In summary, a good correlation between the isolated tissues and cell cultures with regard to P-HCl transport could be observed. In general, BAC caused the most facilitated drug transport within the formulation parameters. Furthermore, the permeation of P-HCl and the lipophilic diclofenac-sodium (D-Na) through lasered PCr was studied. To investigate the effects of photorefractive keratectomy on drug permeation, excimer laser ablations with varying depths were performed on isolated pig eyes. As a result, P-HCl demonstrated a significant enhancement of permeation in relation to the ablation depth. In contrast, corneal epithelial thickness scarcely influenced the permeation rate of D-Na. Another aim of this work was to develop an appropriate application form for topical ocular use of the immunomodulating substance mycophenolate mofetil (MMF) and to investigate the in vitro permeability of PCr for the prodrug MMF and its parent substance mycophenolic acid (MPA). The test formulation consisted of Glutathion-bicarbonate-Ringer's solution, 10% hydroxypropyl- beta-cyclodextrin and 1% MMF. To reach a concentration of 1% of the poor soluble MMF a treatment under autoclaving conditions at 121° C and 200 kPa for 15 min was needed. MPA should be preferred in eye drops because of an higher in vitro availability compared to MMF, an hydrolysis of MMF to MPA in the cornea during permeation and the poor water solubility of MMF. The correlation with in vivo results was not studied in this work but the findings can be assumed as basis for investigations on in vivo models.

Diese Arbeit berichtet über die Planung und den Aufbau eines neuen Viskosimeters und über Viskositätsuntersuchungen einiger metallischer Systeme. Diese letzteren Messungen wurden mit einem vorhandenen Viskosimeter gemacht, in dem kein besseres Vakuum als 10^(-3)mbar und keine höhere Temperatur als 1430K erreicht werden kann. Das beste Vakuum und die maximale erreichbare Temperatur in dem neuen Viskosimeter sind 10^(-6)mbar bzw. 1870K. Diese beiden Grundbedingungen ermöglichen die Viskositätsmessung metallischer Systeme, die aktive Elemente wie Al, Mg und P enthalten oder/und einen höheren Schmelzpunkt besitzen. Mit dem Drei-Zonen-Ofen erlaubt die neue Apparatur auch ein schnelleres Homogenisieren der zu untersuchenden Schmelze, besonders der monotektischen Systeme. Der Einfluß der Temperatur des Torsionsdrahtes und der Anfangsphase der Schwingung auf die Genauigkeit der Viskostätsmessung wurden analysiert und entsprechende Verbesserungen vorgeschlagen. Die untersuchten Systeme sind das Zn-Pb basierte ternäre System, die monotektischen Systeme Ag-Te und Li-Na, das Verbindungssystem Sb-Zn, die halbleitenden Cd-Te Legierungen und Schaummaterialien ZACT und ZACM. / Viscosity of metallic melts and its precise measurement This thesis reports the design and the construction of a new oscillating cup viscometer and the viscosity investigation of several metallic systems. The measurements were carried out with an existing viscometer by which one could not get better vacuum than 10^(-3)mbar or higher temperature than 1430K. With the new apparatus the best vacuum of 10^(-6)mbar and the highest temperature of 1870K can be reached. These two basic conditions permit the measurement of systems which contain active elements such as Al, Mg and P and/or have very hight melting points. The construction of the three-zone furnace in the new viscometer allows the acceleration of the homogenising process, which is especially important for monotectic systems. The influences of the temperature of the torsion thread and the initial oscillating phase on the accuracy of viscosity measurement were analysed and the corresponding solutions were put forward. The investigated systems are the Zn-Pb based ternary system, the monotectic systems Ag-Te and Li-Na, the Sb-Zn system which contains compounds in the solid phases, the semiconducting Cd-Te alloys and the foaming materials ZACT and ZACM.

No description available.

No description available.