The archaeological questions of historical glass have lead to remarkable research activities such as identification and sourcing the raw materials used in the glass production, investigations of the ways in which the colors of glass can be modified due to dissolved and/or colloidal coloring agents, the furnace conditions, and the time of fritting and melting. Considering publications, it can be suggested that compositional studies of well-dated glass samples have supplied useful information concerning raw materials&rsquo / characteristics and technology of glassmaking. Within this context, the aim of this study was to determine elemental compositions and production techniques of some 13th century Seljukian Period window glasses from Alanya excavation region. During the excavations at Alanya archaeological site involving Inner Castle and out of Inner Castle many glass pieces of varying colors have been found. In this study 25 samples from the area have been examined. Elemental analyses have been carried out using X-Ray Fluorescence Spectroscopy (XRF) to determine major, minor, and trace elements. The data v obtained by XRF has revealed that all samples have typical soda-lime-silica composition with the average values of, 68.22 % (SiO2) / 11.3 % (Na2O) / and 6.7 % (CaO). Hierarchical Cluster analysis has been employed and the samples have been grouped depending on their potassium oxide (K2O) and magnesium oxide (MgO) contents which indicate the probable alkali flux source. The colors of the samples are honey-yellow, brown-yellow, navy blue, blue, turquoise, purple, and green. The coloring agents have been determined as Fe, Cu, Co, and Mn. The data from Optical Microscopy has shown that most of the window glasses might have been produced by cylinder technique. Some other samples have revealed the signs of crown technique, and some might have been produced by casting.

During the last few years the scientific interest in chalcogenides glasses has been provoked on account of their properties and new application possibilities. These materials exhibit electrical and optical properties, which make them useful for several potential applications. Specifically the threshold and memory switching behavior and the infrared transmission of many of these glasses make the materials to be well suitable for use in memory devices and in fiber optics. Multicomponent glasses have been found to be more useful for many of these applications since the properties could be tailored for the specific uses. On account of this there has been great deal of interest in recent years in understanding the composition dependent variations of physical properties in these glasses. Models based on network topology and chemical ordering have been proposed to explain the composition dependence of physical properties. The Chemically Ordered Covalent Network (COCN) model is one of the best efforts put forth in this subject. This model predicts distinctive physical properties of these glasses for compositions at which there is a maximum number of heteropolar bonds. A physical model based on changes in network topology with composition has been proposed recently. This model predicts the rigidity to percolate in the network at the mean coordination number <r> = 2.40. This critical value of <r> at which the rigidity percolates is called the mechanical threshold or the rigidity percolation threshold. One more argument based on medium range interactions, existing in these glassy networks, suggests that the mechanical threshold should occur at <r> = 2.67. A general lack of consensus in the existing experimental reports on the mechanical threshold in some chalcogenides glasses prevents one from identifying the correct threshold value of <r>. A systematic study of the composition dependence of glasses with a large glass-forming region is necessary to resolve this controversy. The correct threshold value of <r> and the reason for the departure from this value in the other cases is the first step towards verifying the applicability of this model to chalcogenide glasses. Glasses belonging to IV — V — VI groups are natural candidates for this study because of their large glass forming region. It also seems possible to isolate the chemical threshold from interfering with the mechanical threshold in some of these glasses. In device applications of any semiconductor the optical and the electrical band gaps need to be varied and this is commonly done by doping. The large density of valence alteration pairs and intrinsic disorder of amorphous semiconductors counter-balances the effects of external additives. As a result, it is hard to electrically dope these materials. Non-equilibrium experimental techniques have been used to some extent, but one of the limitations is that they are confined to the thin film state. The finding that p to n type conduction sign changes can be induced by Bi and Pb in bulk Ge-M (M= S, Se and Te) glasses has therefore created special interest. This thesis deals with Ge-Se glass matrix doped with Te, Bi and Pb. The optical, thermal and electrical properties have been studied. The present thesis work is arranged in several chapters. The basic introduction of chalcogenide glasses is given in chapter one. This includes an introduction to chalcogenide glasses followed by a brief discussion on the important structural models, the possible defects in chalcogenide glasses and the electrical, optical and thermal properties of chalcogenide glasses. The second chapter discusses the experimental techniques used in the present investigations. The basic principles and theory behind the experiments, the experimental setup and the experimental procedure leading to the determination of the physical properties are given here. These include information about Differential Scanning Calorimetry (DSC), Photo acoustic (PA) spectroscopy and Photoluminescence studies. In the third chapter the experimental investigations on Ge-Se-Te glasses are presented. The chapter starts with the preparation and characterization of these glasses. It then gives an account of the earlier studies on Ge-Se-Te glasses that are relevant to the present work. The results of the DSC and PA studies are discussed in the following two sections. In the systems with Gex Se80-x Te20 and Gex Se75.x Te25, glasses with less than 20 at. % of Ge do not show any crystallization peak due to Se rich content. But Te and Ge-rich glasses show strong crystallization tendency. The composition dependence of Tg of this glassy system gives an evidence for the occurrence of the topological threshold or mechanical threshold at <r> = 2.40 and chemical threshold at <r> = 2.67. These can be explained on the basis of COCN model. The optical band gap and thermal diffusivity studies also show anomalous behavior at <r> = 2.40 and <r> = 2.67. The experimental results on Ge-Se-Te glasses are summarized in the last section of this chapter. The investigations on Bi doped Ge-Se and Ge-Se-Te glasses are given in the fourth chapter. The chapter starts with a brief introduction of preparation, characterization and a short review of earlier work. In PA studies the anomalous behavior is observed in thermal diffusivity and thermal diffusion length plot at 8-9 at. % of Bi doping of the Ge-Se and Ge-Se-Te glasses where the conduction changes from p to n type. These results are explained on the basis of percolation model and the formation of Bi2Se3 microcrystalline phase. Finally these results are summarized at the end of the chapter. The fifth chapter is devoted to the investigations on Pb doped Ge-Se glasses. It is arranged in five sections; preparation and characterization, earlier work, Photo acoustic and Photoluminescence studies. In PA studies the composition dependence of thermal diffusivity show anomalous behavior at x =F 9 at % of Pb in Pbx Ge42-x Sesg glasses and y = 21 at. % of Ge in Pb2o Gey Seso-y glasses where the conduction changes from p to n type. After that it reaches the maximum. After the conduction sign changes the conductivity increases with addition of respective Pb and Ge concentration in both series of glasses, which is reflected in thermal diffusivity value also. The results have been explained on the basis of COCN model. From PL studies, the PL intensity is high in un-doped Ge42 Scss glasses. With the addition of Pb into Ge-Se system the PL intensity goes down drastically up to 9 at. % of Pb, beyond 9 at. % the PL intensity is approximately the same up to 15 at. %. In the last section the results are summarized. Chapter six summarizes the essential features of the work reported in the thesis. These conclusions are drawn from the present and the earlier reported studies on Ge-Se-Te glasses, Bi doped Ge-Se and Ge-Se-Te glasses and Pb doped Ge-Se glasses. Finally based on the present experimental results, some future work has been suggested which could throw some light on a better understanding of/? to n transition and defects state of these glasses. It is worth extending the microscopic phase separation studies in these glasses. Highly sensitive experimental techniques are needed in this regard. Also some simulation work like Monte-Carlo simulation and Molecular dynamics simulation needs to be undertaken for understanding the microscopic phase separation and the role of defects in carrier type reversal in these glassy materials. All the references cited in the thesis are collected and listed at the end of the thesis.

Thesis (M.S.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains vii, 101 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 57-63).

Not available / text

Not available / text

Not available / text

Microbeam radiation therapy (MRT) is a potential cancer therapy technique that uses an intense X-ray beam produced by a synchrotron. In MRT, an array of microplanar beams, called a microbeam, is delivered to a tumour. The dose at each centre of planar beams is extremely large (several hundred grays) while dose level in the valley between the peaks is below several tens of gray. Moreover, the width of each planar beam is typically 20 - 50 µm, and the distance from a centre of planar-beam to that of adjacent beam is 200 - 400 µm. For the latter reasons, the fundamental requirements for the dosimetry technique in MRT are (1) a micrometer-scale spatial resolution and (2) detection sensitivity at large doses (5 - 1000 Gy). No existing detectors can satisfy those two requirements together. The objective of the Ph.D. research is to develop a prototype dosimetry technique which fulfils the requirements for measuring the dose profile in the microbeam. The currently used approach relies on the indirect detection of X-rays; in which the X-ray dose is recorded on a detector plate, and then the recorded signals are digitized using a reader. Our proposed approach utilizes Sm3+-doped polycrystallites, glasses, and/or suitable glass-ceramics (though our approach is not limited to the use of Sm ion) for the detector plate, in which a valence reduction of Sm3+, that is the conversion of Sm3+ to Sm2+, takes place upon irradiation of X-rays. The extent of reduction is further read out using confocal fluorescence microscopy via the photoluminescence (PL) signals of Sm3+ and Sm2+. The work carried out throughout the course of the research includes the construction of confocal fluorescence microscopy, synthesis and characterizations of dosimeter materials, as well as application tests of our approach for measuring the dose profile of a microbeam used at synchrotron facilities -- Canadian Light Source (CLS), Saskatoon, Canada, European Synchrotron Radiation Facility (ESRF), Grenoble, France, and SPring-8, Hyogo, Japan. Further, the research has shown that 1 % Sm-doped fluoroaluminate glass is one of the best candidates for the type of dosimetric application. It has the dynamic range of ~1 to over 1000 Gy which covers the dose range used in MRT, excellent signal-to-noise ratio (large extent of Sm3+ → Sm2+ change), and excellent stability of recorded signal over time. The recorded signal in the detector is erasable by heating or exposing to light such as UV. Furthermore, with a use of confocal microscope, it has ability to measure the distribution pattern of dose over the cross-section of microbeam. Therefore, we believe that our approach is one of the most promising techniques available.

Magistro praktinėje dalyje kuriu architektūros ir vitražo tarpusavio ryšį. Kauno miesto Ąžuolyno parke įsikūręs „Ąžuolyno sporto centras“ papildo čia pat esantį sporto „miestelį“. Architektai Vilius Adomavičius, Vida Vyšniauskienė ir Darius Čiuta suprojektavo modernų 117 m. ilgio ir 12 m. pločio pastatą, kurio architektūrinėje plastikoje dominuoja stiklas. Pastate įrengtos administracinės, kavinės, spa procedūrų, grožio salono, rūbinės, trenerių kambarių, vandens procedūrų ir sporto salės patalpos. Architektūrinėje situacijoje modeliuoju modernaus vitražo meninės raikšos priemones, remdamasi stiklo medžiagiškumu, spalvos ir mastelių pokyčiais, jų tarpusavio santykiu. Supančių medžių krintančius šešėlius ir jų atspindžius stikle perfrazuoju ažūrinio tinklo stilistika, kuri organiškai kinta, persipynusi su skaidriais ir spalviniais vitražo plotais, tuo būdu pabrėžiu pastato ir supančios aplinkos ryšių išsaugojimą. Sukurdama dviejų stiklo sluoksnių „tinklą“, kuris pasižymi spalvinės gamos įvairove, atkreipiu dėmesį į spalvų veikimą viena kitos atžvilgiu, tarpusavio persipynimą ir emocinę įtaigą. Magistro praktiniame darbe pateikiamas darbo planšetas bei vitažo projekto architektūroje detalė (130 x 95 cm., stiklas, glazūra, smėliasrovė). / In the practical part of my work I create relation between architecture and stained glass. I chose „Ąžuolynas Sport Centre“ that complements „sports town“ situated in Ąžuolynas park in Kaunas. The modern building was created by architects Vilius Adomavičius, Vida Vyšniauskienė and Darius Čiuta. The building is 117 meters long and 12 meters wide. Inside there are administration premise, cafes, a beauty salon, cloakrooms, rooms for trainers, gym, spa and water treatment rooms. Glass dominates compositional expression of the whole building. I design modern stained-glass forms emphasising characteristic glass qualities such as materiality and colour. I base my work on relation between architecture and glass, search for optimal forms that complement architectural lanscape. I incorporate shadows of the trees in the environment and recreate their reflection on glass using openwork grid. This stylistic element is united with transparent and coloured glass areas. I also try to sustain the relation between the building and its environment. Creating a double glass net, which shows a wide spectrum of vibrant colours, I pay attention to colour effectiveness, their relationship between each other and also emotional potency. For the presentation of practical work a plane-table and a detail of stained glass project are represented (130 x 95 cm., glass, glazure, sandblasting).

In this study, the possibilities to produce metallic glass as binder phase in hard metal by means of powder metallurgical methods have been investigated. The aim of the study was to do an initial investigation about metallic glass as alternative binder phase to cobalt in hard metal. Production of samples with metallic glass forming alloys and an amorphous powder as binder phase in hard metal by means of quenching and hot pressing have been performed. Moreover, mechanical alloying of metallic glass forming powder to achieve amorphicity has been performed. The samples and powders were analyzed by means of XRD, LOM, STA, SEM and EDS. The results showed that no glass formation of the binder phase was achieved by quenching, hot pressing or mechanical alloying. However, interesting information about glass formation by means of metallurgical methods was obtained. The main conclusion was that production of metallic glass by means of metallurgical methods is complicated due to changes in the binder phase composition throughout the production process as well as requirements of high cooling rates when quenching and high pressures when hot pressing.

This thesis performed on master level covers an assignment given by the cab division at Volvo Construction Equipment (Eskilstuna, Sweden). The thesis has been carried out by Josefin Hult during the period 2014-01-23 to 2014-05-30 at Mälardalen University. Volvo Construction Equipment manufactures products including wheel loaders, backhoe loaders and articulated haulers. The assignment involves developing the standard door for larger wheel loaders. The current door has a welded frame surrounding the glass that is considered outdated and not cost effective. Volvo Construction Equipment wishes that the door was made in glass in a greater extent. The aim of the assignment has been to generate concepts regarding a glass door that fulfills given requirements. Three research questions have been stated and answered during the process. The product development process has consisted of three phases: information gathering, concept development process and development of detailed concept. For example, field studies and benchmarking have been performed to gather information about competitors’ products and the manufacturing and assembling of the current door. Concepts for handrails, sealant and overall door design have been generated in an iterative process. All components of the door have been developed into a detailed concept during the last phase of the process. The process has resulted in a frameless glass door. The concept suggestion consists of; a tempered sheet of glass, a clip list (sealant) that covers the edges of the glass, two different handrails, inner and outer handles, a gas spring, components to attach handrails against the glass, a cover and a lock mechanism. The major conclusion that is drawn is that it is fully possible to develop a door made in glass in a greater extent than the current door. Many competitors have machines where the door is made in glass in a large extent. This makes it believable that the glass door also will be perceived as timely and more modern and clear. Recommendations have been developed if there is interest in further development. The recommendations include, among others, development of handrail and test of prototype to ensure that all requirements are fulfilled. Figures are produced by the author if not stated otherwise.