Effect of iron on the microstructure of basalt glass-ceramics obtained by the petrurgic method

Basalt glasses may form glass-ceramic materials upon a thermal treatment (TT) if the Fe₂O₃/FeO ratio is greater than 0.5. In this work, a Serra Geral Formation basalt was used to produce different glass-ceramic materials by changing its chemical composition, removing Fe₂O₃ via magnetic separation and adding 20 wt% Fe₂O₃. Glass-ceramics were prepared by melting at 1500°C, followed by a crystallization plateau at 950°C. This petrurgic TT yields dendritic structures upon surface crystallization. With the increase of the iron content, crystallization was more pronounced, as observed in thermal analysis results and optical/scanning electron microscopy. The microstructure analysis shows that these glass-ceramics exhibit at least two different types of crystallization. On the surface, the predominant crystallization was dendritic, while in bulk, crystallization occurred in the form of randomly distributed submicrometric spheroid crystals.     

Optimised one-step compression of femtosecond fibre laser soliton pulses around 1550nm to below 30 fs in highly nonlinear fibre

Optimised compression of femtosecond fibre laser pulses in highly nonlinear fibre is demonstrated. Specifically reported are compressed pulse durations below 30 fs using a simple setup where a single sub-10 cm segment of highly nonlinear fibre is directly spliced to the output pigtail of a commercial femtosecond fibre laser. The compressed pulse quality is confirmed through frequency resolved optical gating measurements.     

Commercially Available Rapid Methods for Detection of Selected Food-borne Pathogens

Generally, the enumeration and isolation of food-borne pathogens is performed using culture-dependent methods. These methods are sensitive, inexpensive, and provide both qualitative and quantitative assessment of the microorganisms present in a sample, but these are time-consuming. For this reason, researchers are developing new techniques that allow detection of food pathogens in shorter period of time. This review identifies commercially available methods for rapid detection and quantification of Listeria monocytogenes, Salmonella spp., Staphylococcus aureus, and Shiga toxin-producing Escherichia coli in food samples. Three categories are discussed: immunologically based methods, nucleic acid-based assays, and biosensors. This review describes the basic mechanism and capabilities of each method, discusses the difficulties of choosing the most convenient method, and provides an overview of the future challenges for the technology for rapid detection of microorganisms.     

Experimental neutron spectroscopy data visualization: adaptive tessellation algorithm

We report on an adaptive binning approach designed for data visualization within scientific disciplines where counting statistics are expected to follow Poisson distributions. We envisage a wide range of applications stemming from astrophysics to the condensed matter sciences. Our main focus of interest concerns, however, neutron spectroscopy data from single-crystal samples where signals span a four-dimensional space defined by three spatial coordinates plus time. This makes widely used equal-width binning schemes inadequate since physically relevant information is often concentrated within rather small regions of such a space. Our aim is thus to generate optimally binned data sets from one-dimensional to three-dimensional volumes to provide the experimentalist with enhanced ability to carry out searches within a four-dimensional space. Several binning algorithms are then scrutinized against experimental as well as simulated data.     

Linearity of terahertz time-domain spectrometers

A method to quantify the linearity and dynamic range of terahertz detectors is reported and used to show that terahertz time-domain-spectrometers exhibit a nonlinear amplitude response at frequencies below 1.5 THz.     

ANOMALOUS RESPONSE IN THE HALIFAX PROCESS

The Halifax process was first proposed as a means of minimising the bulking of activated sludge. In one system using this process, bulking continued to occur. An analysis of the process, using dynamic modelling tools, predicted that the process contains the potential for effluent quality to become worse as the hydraulic loading to the process is reduced — contrary to common experience with more conventional layouts.     

Inflammatory mediators regulate interleukin-8 production by cultured gestational tissues: evidence for a cytokine network at the chorio-decidual interface

The physiology of parturition, and the pathophysiology of preterm labor, is incompletely understood. Infection of gestational tissues may account for a significant proportion of women who experience preterm labor. Interleukin-8 (IL-8), or neutrophil-activating protein (NAP-1), is a potent chemotactic and activating factor for neutrophils and has been implicated in the pathogenesis of inflammatory injury to skin and lung, but has yet to be described in gestational tissues. Cultured chorion and decidual cells obtained from normal human pregnancies were used to evaluate whether these tissues produce IL-8 basally and in response to inflammatory cytokines. As measured by specific IL-8 RIA, chorion and decidual cells produce IL-8 constitutively and in response to IL-1 beta and tumor necrosis factor. Cotreatment of chorion cells or decidual cells with IL-1 beta and actinomycin D or cycloheximide abrogated IL-8 production. Northern blot analysis confirmed that IL-1 beta stimulation of chorion and decidual cells resulted in increased IL-8 messenger RNA expression. Our data support the concept that a complex cytokine network between maternal and fetal gestational tissues exists, and that activation of inflammatory cytokine production in these tissues, including IL-8, likely contributes to the pathophysiology of infection-induced preterm labor.     

Anti-reflective coating for deep UV lithography process enhancement

We describe here performance enhancements provided by an anti-reflective coating (ARC), developed for deep UV applications. The reduction in substrate reflections provided by the ARC layer results in significant increases in resolution capability and process latitude compared to single layer deep UV resist. Increased linewidth control and patterning capability for highly reflective, grainy, and topographical substrates is demonstrated.     

The Thermal-Hydraulic model for the pebble bed modular reactor (PBMR) plant operator training simulator system

This paper provides a discussion of the model development status and verification efforts for the Reactor Core Thermal-Hydraulic model developed for the full-scope plant Operator Training Simulator System of the Pebble Bed Modular Reactor (PBMR). Due to the First of a Kind Engineering nature and lack of reference plant data, model verification has mainly been focused on benchmarking the model configurations against test cases performed by PBMR design analysis codes, i.e. TINTE, VSOP and FLOWNEX.As a first step, due to the symmetrical physical nature of the PBMR core, a two-dimensional (2D) model configuration in radial and axial directions (axial-symmetry) was developed. The design was subsequently extended to a three-dimensional (3D) configuration. Through the use of cross-flow and cross-conduction links, three nearly identical 2D configurations were glued together to form this 3D model configuration. To date, the 3D configuration represents the most comprehensive model to simulate the PBMR core thermo-hydraulics. This paper concludes with the verification of thermodynamic and heat-transfer properties of two steady state (100% and 40% power) conditions between the 3D Reactor Core Thermal-Hydraulic model and the available FLOWNEX and TINTE design code analysis. The transient operations between these two power levels are also discussed.