Viewing angle enhancement for two- and three-dimensional holographic displays with random superresolution phase masks

Holographic displays employing binary phase modulation have been demonstrated to be attractive on the grounds of efficiency and miniaturization, and they offer a plausible approach to two-dimensional (2D) and three-dimensional (3D) image projection and display. A novel algorithm--one-step phase retrieval--and corresponding hardware architecture have recently been proposed, providing the performance required for real-time holographic display. However, since viewing angle varies inversely with pixel size, very small display pixels are required to achieve a wide field of view. This is particularly problematic for 3D displays, as the requirement for a large display with small pixels has hitherto necessitated an unachievably large electrical bandwidth. We present a novel approach, utilizing fixed random pixelated quaternary phase masks of greater resolution than the displayed hologram, to dramatically increase the viewing angle for 2D and 3D holographic displays without incurring a bandwidth penalty or significantly degrading image quality. Furthermore, an algorithm is presented to generate holograms accounting for the presence of such a phase mask, so that only one mask is required.     

AC Bias Characterization of Low Noise Bolometers for SAFARI Using an Open-Loop Frequency Domain SQUID-based Multiplexer Operating Between 1 and 5 MHz

SRON is developing the Frequency Domain Multiplexing (FDM) read-out and the ultra low NEP TES bolometers array for the infra-red spectrometer SAFARI on board of the Japanese space mission SPICA. The FDM prototype of the instrument requires critical and complex optimizations. For single pixel characterization under AC bias we are developing a simple FDM system working in the frequency range from 1 to 5 MHz, based on the open loop read-out of a linearized two-stage SQUID amplifier and high Q lithographic LC resonators. We describe the details of the experimental set-up required to achieve low power loading (<1?fW) and low noise ( $\mathrm{NEP}\sim 10^{-19}~\mathrm{W}/\sqrt{\mathrm{Hz}}$ ) in the TES bolometers. We conclude the paper by comparing the performance of a $4\times 10^{-19}~\mathrm{W}/\sqrt{\mathrm{Hz}}$ TES bolometer measured under DC and AC bias.     

Onset of plasticity in InxGa1−xAs multilayers

Coherently strained In_xGa_1?xAs multilayers with zero net strain have been investigated in order to determine the influence of coherency strains on the yield stress. The deformation behaviour has been studied using both ex- and in situ nanoindentation and transmission electron microscopy. Nanoindentation showed that the pressure required for the onset of yield decreased with increasing coherency strain, consistent with previous work, while the hardness remained constant. Transmission electron microscopy revealed that deformation was more prevalent in one layer. Using these observations, a straightforward analysis has been developed in which the yield pressure of the multilayer is related to the onset of flow in the weaker layer determined by both its intrinsic yield pressure and coherency strains. This gives good agreement with the experimental observations and is consistent with the observations of the effects of internal stresses in films elsewhere in the literature.     

Herausforderungen an Füge‐ und Oberflächentechnik für zukünftige Leichtbaukonstruktionen im Automobilbau

For the reduction of the weight of vehicle hot‐rolled magnesium alloys as well as carbon fiber reinforced plastics (CFK) shall be integrated into the body structure. Both light weight materials electrochemically are not compatible with galvanized steels or aluminium alloys, unless great efforts of corrosion protection measures are taken. From electrochemical investigations an oxidceramic surface layer deposited by plasmachemical oxidation can be recommended as a promising solution. The low‐porous oxidation deposit with limited insulation effect can be painted by e‐coat in high quality after joining in the body shop and before the full paint system will be deposited. In opposite to magnesium CFK parts have, however, electrochemically a very noble character causing galvanic corrosion of attached metallic parts when the carbon fibers are not fully embedded in the matrix or damaged by the cutting. Only joining elements made from stainless steels or titanium alloys (e. g. Ti‐6Al‐4V) are suitable for the joining of CFK by screwdriving and riveting technology to avoid galvanic corrosion. From view of compatibility of materials, a severe anodic corrosion risk can be eliminated by isolation through adhesive bonding in the flanges and an additional sealing to prevent from electrolyte ingress.     

Emerging use of isotope ratio mass spectrometry as a tool for discrimination of 3,4-methylenedioxymethamphetamine by synthetic route

Drug profiling, or the ability to link batches of illicit drugs to a common source or synthetic route, has long been a goal of law enforcement agencies. Research in the past decade has explored drug profiling with isotope ratio mass spectrometry (IRMS). This type of research can be limited by the use of substances seized by police, of which the provenance is unknown. Fortunately, however, some studies in recent years have been carried out on drugs synthesized in-house and therefore of known history. In this study, 18 MDMA samples were synthesized in-house from aliquots of the same precursor by three common reductive amination routes and analyzed for 13C, 15N, and 2H isotope abundance using IRMS. For these three preparative methods, results indicate that 2H isotope abundance data is necessary for discrimination by synthetic route. Furthermore, hierarchical cluster analysis using 2H data on its own or combined with 13C and/or 15N provides a statistical means for accurate discrimination by synthetic route.     

Characterisation of a TES-Based X-ray Microcalorimeter in the Energy Range from 150 to 1800 eV Using an Adiabatic Demagnetisation Refrigerator

We characterised a TES-based X-ray microcalorimeter in an adiabatic demagnetisation refrigerator (ADR) using synchrotron radiation. The detector response and energy resolution was measured at the beam-line in the PTB radiometry laboratory at the electron storage ring BESSY II in the range from 200 to 1800 eV. We present and discuss the results of the energy resolution measurements as a function of energy, beam intensity and detector working point. The measured energy resolution ranges between 1.5 to 2.1 eV in the investigated energy range and is weakly dependent on the detector set point. A first analysis shows a count-rate capability, without considerable loss of performance, of about 500 counts per second.      

Verification of cardiac tissue electrophysiology simulators using an N-version benchmark

Ongoing developments in cardiac modelling have resulted, in particular, in the development of advanced and increasingly complex computational frameworks for simulating cardiac tissue electrophysiology. The goal of these simulations is often to represent the detailed physiology and pathologies of the heart using codes that exploit the computational potential of high-performance computing architectures. These developments have rapidly progressed the simulation capacity of cardiac virtual physiological human style models; however, they have also made it increasingly challenging to verify that a given code provides a faithful representation of the purported governing equations and corresponding solution techniques. This study provides the first cardiac tissue electrophysiology simulation benchmark to allow these codes to be verified. The benchmark was successfully evaluated on 11 simulation platforms to generate a consensus gold-standard converged solution. The benchmark definition in combination with the gold-standard solution can now be used to verify new simulation codes and numerical methods in the future.     

Influence of culture conditions on metal-induced responses in a cultured rainbow trout gill epithelium

A primary culture technique for rainbow trout (Oncorhynchus mykiss) gill cells was optimized to better represent the intact gill in vivo in response to waterborne toxic metals. Modifications in cell seeding density and culture conditions resulted in a gill epithelial cell culture model, which displayed classic in vivo responses to toxic metals. Metallothionein-A (MTA), metallothionein-B (MTB), zinc transporter-1 (ZnT-1), glutathione-S-transferase (GST), and glucose-6-phosphate-dehydrogenase (G6PD) all showed dose-dependent increases in expression at the mRNA level in response to waterborne zinc. Of these genes, the change in zinc-induced expression relative to the control was greatest for MTA, MTB, and ZnT-1. MT expression was also induced by silver, lead, copper, and cadmium. Cells cultured with freshwater on the apical side maintained the net transepithelial influx of Ca2+ displayed by freshwater trout gills in vivo, and there was an active inward movement of Ca2+. Waterborne zinc applied to the apical compartment reduced the net uptake of Ca2+ by stimulating the efflux component. The use of endogenous metal-responsive gene expression and inhibition of ion transport in the developed cell culture system will facilitate studies of metal-gill interactions and may prove to have future practical applications within biomonitoring of natural waters.     

The Impact of Kilning on Enzymatic Activity of Buckwheat Malt

This study investigated the impact of kilning on α‐amylase, β‐amylase (total and soluble), β‐glucanase and protease activities in buckwheat malt. Common buckwheat (Fagopyrum esculentum) was steeped at 10°C for 12 h, germinated at 15°C for 4 days and kilned at 40°C for 48 h. Moisture content and enzymatic activities were determined throughout the kilning period. Results showed moisture content was reduced from 44% to 5% after 48 h of kilning at 40°C. β‐Amylase was found to exist in a soluble and latent form in buckwheat. Maximum activity of (a) α‐amylase, (b) total β‐amylase, (c) soluble β‐amylase, (d) β‐glucanase and (e) protease activity occurred after (a) 8, (b) 7, (c) 30, (d) 0, and (e) 8 h of kilning, respectively. The final malt exhibited very little β‐glucanase and cellulase activity. Proteolytic activity was low in buckwheat malt when compared to the barley malt control. All enzymatic activities were found to decrease during the kilning stage. Results indicated that after prolonged kilning at 40°C, inactivation of hydrolytic enzymes occurred; two‐stage kilning for shorter periods is recommended. Although, amylolytic activity was low in malted buckwheat, buckwheat malt shows potential as an ingredient for the brewing and cereal industry.     

Antioxidant Activity and Determination of Phenolic Compounds from <Emphasis Type="Italic">Eugenia involucrata</Emphasis> DC. Fruits by UHPLC-MS/MS

Fruits have been the focus of several studies aimed at finding new antioxidant sources for protection against the damage caused by reactive species. In this study, the antioxidant activity and the presence of phenolic compounds in all parts (peel, pulp, and seeds) of Eugenia involucrata DC. fruits were evaluated. DPPH^·, ABTS^·+, and ORAC methods were used to determine the antioxidant activity, and an UHPLC-MS/MS method was developed for determining the phenolic compounds (gallic, chlorogenic, ferulic, p-coumaric and ellagic acids, quercetin, and myricetin). In the determination of both antioxidant activity and phenolic composition, the efficiency of solvents with different polarities—methanol/H₂O (80:20, v/v), ethanol/H₂O (80:20, v/v), methanol/acidified water with phosphoric acid pH 3.00 (80:20, v/v), and ethyl acetate—for the extraction of the phenolic compounds, was also evaluated. All parts of E. involucrata fruits showed antioxidant activity, in the range of 36.68 ± 1.44 to 873.87 ± 18.24 μmol TE g^?1, being the highest values found in the seeds and peel when more polar extraction solvents were used. Six, five, and three phenolic compounds were identified and quantified in the pulp, peel, and seeds, respectively, with the highest abundance as p-coumaric acid (14 ± 2 mg kg^?1) in the pulp, quercetin (47 ± 5 mg kg^?1) in the peel, and gallic acid (74 ± 4 mg kg^?1) in the seeds, also when more polar solvents were used. Although antioxidant activity methods suggested that the peel and seeds have more antioxidant potential, a wider variety of compounds were determined in the pulp.