Exciton-Polaritons in BODIPY-filled Microcavities

This thesis concerns the fabrication and study of strongly coupled organic microcavities containing a series of different boron-dipyrromethene (BODIPY) fluorescent dyes dispersed in an optically inert polystyrene matrix. The photophysics of the different BODIPY dyes are first studied and it is shown that they are promising materials for polariton condensation. DBR-DBR microcavities containing thin films of dye/polystyrene blends are then investigated under angular white-light reflectivity and CW laser excitation; measurements that show that they can enter the strong coupling regime. Polaritons in such high quality factor structures are shown to undergo a phase transition when excited with a high density pulsed excitation, forming a polariton condensate. Power dependent and interferometry measurements are used to identify the condensation threshold and the spatial coherence length of the polariton condensate. Lower Q-factor microcavities, comprised of two silver mirrors are fabricated, containing two different BODIPY dyes. Energy transfer between the molecules is engineered using two different processes; (1) direct short-range dipole-dipole coupling between the molecules, and (2) polariton-mediated energy transfer. We assess the efficiency of the energy transfer by quantifying the polariton population density along each polariton branch following laser excitation. It is concluded that short-range (<3 nm) energy transfer induced by dipole-dipole coupling is more efficient compared to long-range (60 nm) polariton-mediated energy transfer, although the long-range process is estimated to transfer up to 87% of states to the lower-polariton branch. The generation of anti-Stokes polariton fluorescence is studied in low Q-factor metallic cavities following resonant excitation at the bottom of the lower polariton branch. Here, it is concluded that thermal energy in the system provides the excess of energy needed for emission of photons having higher energy than that of the initial laser excitation. Using temperature dependent and time resolved measurements it is concluded that polaritons return to the exciton reservoir by optically pumping a molecule in a vibrationally excited ground state. The exciton created then emits fluorescence that populates polariton states with an energy higher than the laser energy resulting in anti-Stokes polariton fluorescence. We believe such systems will be of significant interest in exploring laser-cooling phenomena in solid-state systems

Motivational and attitudinal aspects of ethnic supplementary school attendance : application of Lisrel and Fishbein to a study of Greek supplementary schools in London.

SIGLEAvailable from British Library Document Supply Centre-DSC:DX216777 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

An evidence synthesis exploring the use of galvanic vestibular stimulation (GVS) for rehabilitation of stroke

Stroke is a neurological deficit caused by a rapidly developing loss of neurons in one area of the brain resulting in loss of function. It is reportedly one of the leading causes of death and disability across the world and it is strongly associated with motor, sensory and cognition impairments that affect activities of daily living and overall quality of life. Galvanic Vestibular Stimulation (GVS) is a non-invasive method using surface electrodes to apply electrical stimulation over the mastoid processes of the skull which are overlying the vestibular nerve. It’s use originates from the early 1800s. It has been used as a method of investigating the vestibular system, how the brain processes vestibular signaling combined with other sensory signals and has been explored relative to the control of eye movements, perceived head in space position and control of balance/upright stance. More recently, clinical trial findings suggest that GVS could contribute towards rehabilitation of balance impairment, disordered postural alignment and neglect disorders, all possible sequalae of stroke. This study will undertake the first evidence synthesis project, starting with a scoping review, to characterize the therapeutic use of GVS for people with stroke

Photogrammetric Survey for the Architectural Restoration of Ecclesiastical Cultural Heritage Monuments: The Case Study of the Church of the Holy Cross in Tochni

This paper investigates the methodology of the digital documentation of an ecclesiastical monument in Tochni, Cyprus. The study very briefly describes the architectural history of the monument, as well as the changes that resulted in its current ruined condition. A photogrammetric survey of the monument was conducted to obtain its architectural elements, and subsequently conduct a restoration proposal. The aim of the survey is to investigate the use of photogrammetry using UAVs to examine historical monuments, in order to have a better understanding of the structure and elements that are difficult to measure and study in detail through traditional documentation

Anomalous origin of the left anterior descending coronary artery from the right coronary artery

Dual left anterior descending coronary artery (LAD) originating from the left main stem and the right coronary artery (RCA) (Type IV dual LAD) is a very rare coronary artery anomaly. In this report, we describe a 49 year old woman presenting with unstable angina and positive for myocardial ischemia exercise tolerance test who subsequently was found to have this coronary anomaly.The diagnosis was made with coronary angiography.This anomaly has been reported to occur in 0.01 — 0.7% of patients under going cardiac catheterization. To our knowledge, only a few such cases have been published in the literature so far

The First Attend for a Holistic HBIM Documentation of UNESCO WHL Monument: The Case Study of Asinou Church in Cyprus

The study examines the documentation of the Asinou Monument within the auspices of the H2020-SC6-R&I-INCEPTION project. The project focuses on the use of innovative 3D modelling of cultural heritage through an inclusive approach for 3D reconstruction of monuments, as well as the built and social environments over time. The project will enrich European identity by examining how European cultural heritage evolves over time. Therefore, data acquisition techniques and 3D reconstruction and modelling methodologies for data processing were examined using the Asinou Church as a case study. Asinou Church is a 11th century church located in the Troodos Mountains of Cyprus, which is a UNESCO World Heritage Site. This unique monument contains some of the finest Byzantine wall paintings in Cyprus which date between the 11th to the 17th century. Their outstanding historical value is very exceptional and makes their documentation a great challenge for the present ICT technologies. Different multimodal techniques, such as photogrammetry, laser scanning, image processing, video and audio were used for the data acquisition of all detailed features of the tangible building and the intangible story (liturgy). Following, the information was processed to create a 3D model in order to document the church using Building Information Modeling (BIM). The church was digitally reconstructed in a 3D BIM model, where it was then processed to produce a Heritage Building Information Model (H-BIM) in order to create a prototype for a holistic documentation and further study.Part of the Lecture Notes in Computer Science book series (LNCS, volume 11196

The innovative documentation of cultural heritage using H-BIM: Case study of Asinou church

Event: SPIE Remote Sensing, 2018, Berlin, GermanyThe study examines the documentation of the Asinou Monument within the auspices of the H2020-SC6-R&IINCEPTION project. The project realises innovation in 3D modelling of cultural heritage through an inclusive approach for time-dynamic 3D reconstruction of artefacts, built and social environments. It enriches the European identity through understanding of how European cultural heritage continuously evolves over long periods of time. In this study, digital techniques for data acquisition and methodologies for data processing were examined using the Asinou Church as a case study. Asinou Church is a 11th century shrine to the Virgin Mary, located in the Troodos Mountains of Cyprus and is a UNESCO World Heritage Site and contains some of the finest Byzantine wall paintings in Cyprus which date between the 12th to the 17th century. Different techniques, such as photogrammetry, laser scanning, drones, video and photographs were used for the data acquisition of all features of the church, which were then processed to create a 3D model and document the church using Building Information Modeling (BIM). The church was digitally reconstructed in a 3D BIM model, where it was then processed to produce a Heritage building Information Model (H-BIM) in order to create an information database for further study