Solid immersion lens applications for nanophotonic devices

Solid immersion lens (SIL) microscopy combines the advantages of conventional microscopy with those of near-field techniques, and is being increasingly adopted across a diverse range of technologies and applications. A comprehensive overview of the state-of-the-art in this rapidly expanding subject is therefore increasingly relevant. Important benefits are enabled by SIL-focusing, including an improved lateral and axial spatial profiling resolution when a SIL is used in laser-scanning microscopy or excitation, and an improved collection efficiency when a SIL is used in a light-collection mode, for example in fluorescence micro-spectroscopy. These advantages arise from the increase in numerical aperture (NA) that is provided by a SIL. Other SIL-enhanced improvements, for example spherical-aberration-free sub-surface imaging, are a fundamental consequence of the aplanatic imaging condition that results from the spherical geometry of the SIL. Beginning with an introduction to the theory of SIL imaging, the unique properties of SILs are exposed to provide advantages in applications involving the interrogation of photonic and electronic nanostructures. Such applications range from the sub-surface examination of the complex three-dimensional microstructures fabricated in silicon integrated circuits, to quantum photoluminescence and transmission measurements in semiconductor quantum dot nanostructures

Working towards a conservation plan for fish parasites: Cyprinid parasites from the south African cape fold freshwater ecoregion as a case study

The preservation of the world's biodiversity for future generations has been a global objective for many years, with the establishment of the International Union for Conservation of Nature (IUCN) Red List of Threatened Species in 1964. However, the conservation of parasites is a more recent development and, due to the difficulty in obtaining data and studying some of the parasitic species, comes its own series of challenges. Using parasites of cyprinid hosts (one critically endangered, one endangered and three near threatened) collected from South Africa's Cape Fold freshwater ecoregion (CF) as a case study, this paper discusses the challenges and possible solutions for implementing a fish parasite conservation project. Novel data on the fish parasites (1819 metazoan parasite individuals, representing the Acanthocephala, Cestoda, Copepoda, Digenea, Monogenea and Nematoda) of the CF are provided from the five endemic hosts, Cheilobarbus serra (Peters, 1864), Labeobarbus seeberi (Gilchrist et Thompson, 1913), Pseudobarbus phlegethon (Barnard, 1938), Sedercypris calidus (Barnard, 1938), and Sedercypris erubescens (Skelton, 1974). Conservation statuses for selected parasite taxa are also proposed based on the conservation statuses of the fish hosts, according to the Conservation Assessment Methodology for Animal Parasites (CAMAP)

Twisted Poincare duality for some quadratic Poisson algebras

We exhibit a Poisson module restoring a twisted Poincaré duality between Poisson homology and cohomology for the polynomial algebra R=C[X1Xn] endowed with Poisson bracket arising from a uniparametrised quantum affine space. This Poisson module is obtained as the semiclassical limit of the dualising bimodule for Hochschild homology of the corresponding quantum affine space. As a corollary we compute the Poisson cohomology of R, and so retrieve a result obtained by direct methods (so completely different from ours) by Monnier

Dualising complexes and twisted Hochschild (co)homology for noetherian Hopf algebras

We show that many noetherian Hopf algebras A have a rigid dualising complex R with [FORMULA]. Here, d is the injective dimension of the algebra and ν is a certain k-algebra automorphism of A, unique up to an inner automorphism. In honour of the finite-dimensional theory which is hereby generalised we call ν the Nakayama automorphism of A. We prove that ν=S2ξ, where S is the antipode of A and ξ is the left winding automorphism of A determined by the left integral of A. The Hochschild homology and cohomology groups with coefficients in a suitably twisted free bimodule are shown to be non-zero in the top dimension d, when A is an Artin–Schelter regular noetherian Hopf algebra of global dimension d. (Twisted) Poincaré duality holds in this setting, as is deduced from a theorem of Van den Bergh. Calculating ν for A using also the opposite coalgebra structure, we determine a formula for S4 generalising a 1976 formula of Radford for A finite-dimensional. Applications of the results to the cases where A is PI, an enveloping algebra, a quantum group, a quantised function algebra and a group algebra are outlined

Qualidade de melões (Cucumis melo L. var. cantalupensis Naud.), híbrido Torreon, produzidos em hidroponia e armazenados em embalagens de polietileno Quality of Torreon hybrid melon fruits (Cucumis melo L. var. cantalupensis Naud.) grown in hydroponic system and stored in polyethylene packaging

Este experimento teve por objetivos avaliar a permeabilidade de filmes de polietileno de diferentes espessuras e densidades ao O2 e ao CO2, a composição gasosa (O2, CO2 e etileno) formada no interior das embalagens e a qualidade físico-química de melões (Cucumis melo L. var. cantalupensis Naud.), híbrido Torreon, produzidos no sistema hidropônico "Nutrient Film Technique" (NFT) e armazenados em embalagens de polietileno. Os tratamentos avaliados foram: (1) armazenamento refrigerado (sem uso de filme); (2) polietileno de baixa densidade (PEBD) de 40&micro;m; (3) PEBD de 60&micro;m; (4) PEBD de 90&micro;m; (5) polietileno de média densidade (PEMD) de 40&micro;m; (6) PEMD de 60&micro;m. Os frutos permaneceram armazenados durante 25 dias a 3,8&plusmn;0,2&deg;C e por mais dois dias a 20&deg;C. Os filmes de PEBD de 60 e 90&micro;m e o PEMD de 60&micro;m apresentaram menor permeabilidade ao CO2, mantendo as maiores concentrações de CO2 nas embalagens. O filme de PEBD de 90&micro;m apresentou menor permeabilidade ao O2. A menor concentração de etileno foi obtida com o uso de PEBD de 40&micro;m. O uso de filmes reduziu drasticamente a perda de massa dos frutos, quando comparados aos frutos não embalados. Os frutos acondicionados na embalagem de PEBD de 40&micro;m mantiveram uma maior firmeza da polpa após o período de armazenamento, não diferindo estatisticamente dos frutos armazenados em PEMD de 40&micro;m. Já a incidência de podridões foi significativamente menor nos frutos armazenados em PEMD de 60&micro;m. De modo geral, os filmes avaliados mantêm semelhante a qualidade físico-química de melões híbrido Torreon produzidos hidroponicamente no sistema NFT.<br>This study was carried out to evaluate the permeability to O2 and CO2, and gas composition (O2, CO2 and ethylene) inside packages of different thickness and density polyethylene films. Moreover, the physical and chemical quality of Torreon hybrid melon fruit (Cucumis melo L. var. cantalupensis Naud.) grown in a Nutrient Film Technique hydroponic system and stored within polyethylene packages were evaluated. Evaluated treatments were: (1) cold storage (control); packaging with (2) low-density polyethylene (LDPE) of 40&micro;m; (3) LDPE of 60&micro;m; (4) LDPE of 90&micro;m; (5) medium-density polyethylene (MDPE) of 40&micro;m; (6) MDPE of 60&micro;m. Fruits were stored during 25 days at 3.8&plusmn;0.2&deg;C plus two days of shelf-life at 20&deg;C. LDPE of 60 and 90&micro;m and MDPE of 60&micro;m had lower CO2-permeability, allowing the higher CO2 concentrations inside the packages. LDPE of 90&micro;m had the lowest O2-permeability. Lower ethylene concentration was observed in 40&micro;m-LDPE bags. Packaging decreased drastically fruit weight loss, when compared with non-packaged fruits. Flesh firmness was higher in fruits stored in 40&micro;m-LDPE, but was not different from 40&micro;m-MDPE-stored fruits. Rot incidence in turn was significantly lower in fruits stored in 60&micro;m-LDPE. In general, packaging of ‘Torreon’ melon fruit, grown in a hydroponic system, with the evaluated polyethylene films allowed similar physical and chemical quality