Enhanced and directional single photon emission in hyperbolic metamaterials

We propose an approach to enhance and direct the spontaneous emission from isolated emitters embedded inside hyperbolic metamaterials into single photon beams. The approach rests on collective plasmonic Bloch modes of hyperbolic metamaterials which propagate in highly directional beams called quantum resonance cones. We propose a pumping scheme using the transparency window of the hyperbolic metamaterial that occurs near the topological transition. Finally, we address the challenge of outcoupling these broadband resonance cones into vacuum using a dielectric bullseye grating. We give a detailed analysis of quenching and design the metamaterial to have a huge Purcell factor in a broad bandwidth inspite of the losses in the metal. Our work should help motivate experiments in the development of single photon sources for broadband emitters such as nitrogen vacancy centers in diamond.Comment: 29 pages, 9 figure

Real Pension Rights as a Control Mechanism for Pension Fund Solvency

This paper models policy responses to changes in solvency by Dutch occupational pension funds using a unique panel dataset containing the balance sheets of all registered pension funds in the Netherlands over a period of 15 years (1993-2007). The model describes how nominal pension rights are expanded, by e.g. indexation or backservice, or, on the contrary, how the current pension accumulation is skimmed, e.g. by setting the pension premium over its actuarially fair price to build buffers. Policy responses are explained by the funding ratio and other pension fund characteristics such as pension funds' size and type, and participants' ages. We find that pension rights are expanded in line with the funding ratio, but that the pension funds' response function exhibits two sharp and significant behavioural breaks, close to the minimum funding ratio of 105% and the target ratio of around 125%. These levels also play a pivotal role in current supervisory regulation. We further find that large pension funds and grey funds are relatively generous to participants.pension funds, pension rights, risk sharing instruments, indexation, funding ratio, solvability, regime shifts.

Enhancement of Volumetric Specific Impulse in HTPB/Ammonium Nitrate Mixed Hybrid Rocket Systems

Hybrid rocket systems are safer and have higher specific impulse than solid rockets. However, due to large oxidizer tanks and low regression rates, hybrid rockets have low volumetric efficiency and very long longitudinal profiles, which limit many of the applications for which hybrids can be used. This research investigates a method for increasing the volumetric efficiency and improving the form factor of hybrid rocket systems by a non-combustible load of solid oxidizer to the hybrid fuel grain. Including such oxidizers increases the regression rate of the fuel and lowers the amount of fluid oxidizer needed for optimal combustion. This type of solution is referred to as a “mixed hybrid”. Ammonium perchlorate is often the oxidizer of choice for these applications. However, ammonium perchlorate is extremely dangerous to work with and is an environmental pollutant. This study suggests the use of ammonium nitrate in place of ammonium perchlorate as a more environmentally friendly, lower risk oxidizer in mixed hybrid rocket systems. Presented results quantify the effects of ammonium nitrate in lab scale tests. Further research paths for ammonium nitrate mixed hybrids are outlined

Laughing Out Loud: American Indian Comedy as a Force for Social Change

Activism entails not only individuals overtly campaigning for changes in public spheres, but in other ways and strategies as well. One of these other avenues is the use of political satire and humor. Comedy publicizes frustrations of American issues, just as sit-ins, walk-outs, or marches do. For the most part, scholars fail to address the importance of humor. This work researches not only the comedic works of Charlie Hill, the 1491s, and other American Indian comedians, but also how their craft possibly alters stances and opinions. These comedians have a voice, and, therefore, deserve examination. This work shows the influence of these comedians by revealing and detailing theories of humor and how comics implement these theories into their routines. By researching humor and the theory behind the craft, this thesis focuses on how American Indian comedians use their profession as a means to advocate for social and political change. The work ultimately argues that scholars need to tap into this approach of social and political activism

From Birds to Drug-Resistant Cancer, a novel In situ Methodology to Explore Divergent Genome Evolution

Fluorescent hybridisatio nmethodologies have not changed in principles over the past 30 years, with the increase of computational sequencing technologies causing the replacement of in situ hybridisations. Fluorescence in situ hybridisation (FISH) is in need of a refresh to be a worthwhile tool in a modern day cytogenetic laboratory to overcome short comings of these new methods. The creation of the novel multilayer FISH protocol has effectively eliminated many negative aspects of classic FISH based experiments, such as a large reduction in cost and is no longer as limited by fluorophore availability. Here presented within this thesis is the creation of this methodology and application to a wide variety of cytogenetic hypothesises. Key species from the Galliform order were investigated in order to detect previously missed intrachromosomal rearrangements within their macrochromosomes, a premise formerly overlooked. Rearrangements were found within chromosomes of the galliforme species used such as E.chinensis which displays a intrachromosomal inversion on the p-arm of chromosome 2. Furthermore, the creation of an interphase state folding prediction tool has been used to assess the arrangement of macrochromosomes during cellular growth stages within G.gallus. Here it is noted that there are particular arrangements identified which are similar across chromosomes studied. The chicken lymphoma cell line DT40 is of great importance in B-cell receptor studies along with gene disruption experiments. Presented here is an updated karyotype for the cell line. Here shows contrasting and more in-depth evidence of aberrations to further develop our understanding of the genomic arrangement of this useful cell line. The level of tumour heterogeneity in a cancer is a diagnostic tool allowing clinicians to comment on therapeutic choices and prognosis of the disease. Found to be dominant in recurrent cancers, cytotoxic resistant tumour cell populations may indeed exist within initial primary tumours at low frequency to be positively selected during chemotherapy. Within a neuroblastoma cell line,and cyto-toxic resistant derivatives lines,there has been identified a level of genomic heterogeneity which may give clues towards the generation of drug resistance mechanisms

Plants are technologies

Histories of Technology, the Environment and Modern Britain brings together historians with a wide range of interests to take a uniquely wide-lens view of how technology and the environment have been intimately and irreversibly entangled in Britain over the last 300 years. It combines, for the first time, two perspectives with much to say about Britain since the industrial revolution: the history of technology and environmental history. Technologies are modified environments, just as nature is to varying extents engineered. Furthermore, technologies and our living and non-living environment are both predominant material forms of organisation – and self-organisation – that surround and make us. Both have changed over time, in intersecting ways. Technologies discussed in the collection include bulldozers, submarine cables, automobiles, flood barriers, medical devices, museum displays and biotechnologies. Environments investigated include bogs, cities, farms, places of natural beauty and pollution, land and sea. The book explores this diversity but also offers an integrated framework for understanding these intersections