A Thermal Neutron Image Intensification System

An image intensifier tube of the vacuum tube type, sensitive to thermal neutrons has been developed and tested. The tube provides a bright visible output signal for an incoming thermal neutron image. Sensitivity, resolution, speed, contrast and relative response to radiation other than thermal neutrons all appear to be adequate for application to neutron imaging studies employing either reactor or non-reactor thermal neutron sources. The above characteristics, and applications of the system, are discussed.     

Gentle STEM: ADF imaging and EELS at low primary energies

Aberration correction of the scanning transmission electron microscope (STEM) has made it possible to reach probe sizes close to 1 Å at 60 keV, an operating energy that avoids direct knock-on damage in materials consisting of light atoms such as B, C, N and O. Although greatly reduced, some radiation damage is still present at this energy, and this limits the maximum usable electron dose. Elemental analysis by electron energy loss spectroscopy (EELS) is then usefully supplemented by annular dark field (ADF) imaging, for which the signal is larger. Because of its strong Z dependence, ADF allows the chemical identification of individual atoms, both heavy and light, and it can also record the atomic motion of individual heavy atoms in considerable detail. We illustrate these points by ADF images and EELS of nanotubes containing nanopods filled with single atoms of Er, and by ADF images of graphene with impurity atoms.     

On Surface Losses in Direct Metal Laser Sintering Printed Millimeter and Submillimeter Waveguides

Different lengths of WR3 (220–330 GHz) and WR10 (75–110 GHz) waveguides are fabricated through direct metal laser sintering (DMLS). The losses in these waveguides are measured and modelled using the Huray surface roughness model. The losses in WR3 are around 0.3 dB/mm and in WR10 0.05 dB/mm. The Huray equation model is accounting relatively good for the attenuation in the WR10 waveguide but deviates more in the WR3 waveguide. The model is compared to finite element simulations of the losses assuming an approximate surface structure similar to the resulting one from the DMLS process.     

Experimental Study on Phosphorus Partitions Between Liquid Iron and Liquid Slags Based on DRI

Metallurgical and Materials Transactions B - Phosphorus partition between liquid iron and CaO-SiO2-MgO-FeOx slags have been investigated experimentally. Fe doped with Fe3P was equilibrated, at 1873...     

Self‐Assembly of Mechanoplasmonic Bacterial Cellulose–Metal Nanoparticle Composites

Nanocomposites of metal nanoparticles (NPs) and bacterial nanocellulose (BC) enable fabrication of soft and biocompatible materials for optical, catalytic, electronic, and biomedical applications. Current BC–NP nanocomposites are typically prepared by in situ synthesis of the NPs or electrostatic adsorption of surface functionalized NPs, which limits possibilities to control and tune NP size, shape, concentration, and surface chemistry and influences the properties and performance of the materials. Here a self‐assembly strategy is described for fabrication of complex and well‐defined BC–NP composites using colloidal gold and silver NPs of different sizes, shapes, and concentrations. The self‐assembly process results in nanocomposites with distinct biophysical and optical properties. In addition to antibacterial materials and materials with excellent senor performance, materials with unique mechanoplasmonic properties are developed. The homogenous incorporation of plasmonic gold NPs in the BC enables extensive modulation of the optical properties by mechanical stimuli. Compression gives rise to near‐field coupling between adsorbed NPs, resulting in tunable spectral variations and enhanced broadband absorption that amplify both nonlinear optical and thermoplasmonic effects and enables novel biosensing strategies.     

Steering the Craft: UI Elements and Visualizations for Supporting Progressive Visual Analytics

Progressive visual analytics (PVA) has emerged in recent years to manage the latency of data analysis systems. When analysis is performed progressively, rough estimates of the results are generated quickly and are then improved over time. Analysts can therefore monitor the progression of the results, steer the analysis algorithms, and make early decisions if the estimates provide a convincing picture. In this article, we describe interface design guidelines for helping users understand progressively updating results and make early decisions based on progressive estimates. To illustrate our ideas, we present a prototype PVA tool called Insights Feed for exploring Twitter data at scale. As validation, we investigate the tradeoffs of our tool when exploring a Twitter dataset in a user study. We report the usage patterns in making early decisions using the user interface, guiding computational methods, and exploring different subsets of the dataset, compared to sequential analysis without progression.     

In search of the comfortable indoor environment: A comparison of the utility of objective and subjective indicators of indoor comfort

Today, many procedures for assessing the indoor environment rely on both subjective and objective indicators (e.g. ANSI/ASHRAE 55-2004; ISO 10551). It is however unclear how these two types of measurements are related to perceived comfort. This article aims at assessing the relative utility of subjective (rating scale measures) and objective indicators of perceived comfort of indoor environments. In a hospital setting, physical environmental variables (e.g. temperature, relative humidity and noise level) were simultaneously measured as respondents (both patients and staff) rated their perception of the indoor environment. Regression analyses indicated that the subjective sensory ratings were significantly better than objective indicators at predicting overall rated indoor comfort. These results are discussed in relation to existing measurement procedures and standards.     

Syntheses and Analyses of N,N′‐Dinitrourea

N,N′‐Dinitrourea was prepared through nitration of urea at low temperature in mixed acids in 67 % yield. The prepared material was pure and found to be stable at room temperature. The properties of N,N′‐dinitrourea were analysed by: TG, DSC, ignition test in Wood's metal bath, NMR, MS, FT‐IR, gaspycnometry and BAM impact and friction sensitivity tests. N,N′‐Dinitrourea was found to have a very high density and positive oxygene balance. It was, however, found to be sensitive both to impact and friction.     

Fabrication and mechanical response of commingled GF/PET composites

The mechanical properties and the response to mechanical load of continuous glass fiber reinforced polyethylene terephthalate (GF/PET) laminates have been characterized. The laminates were manufactured by compression molding stacks of novel woven and warp knitted fabrics produced from commingled yarns. The laminate quality was examined by means of optical and scanning electron microscopy. Few voids were found and the laminate quality was good. Resin pockets occurred in the woven laminates, originating from the architecture of the woven fabric. The strength of the fiber/matrix interface was poor. Some problems were encountered while manufacturing the laminates. These led to fiber misalignment and consequently resulted in tensile mechanical properties that were slightly lower than expected. Flexural failures all initiated as a result of compression, and it is possible that the compression strength of the matrix material, rather than its tensile strength, might limit the ultimate mechanical performance of the composites. Flexural failures for both materials were very gradual. The warp knitted laminates were stronger and stiffer than the woven laminates. The impact behavior was also investigated; the woven laminates exhibited superior damage tolerance compared with the warp knitted laminates.