Selecting an ignition criterion methodology for use in a radiative fire spread submodel

Research is ongoing to increase the functionality of the fire zone modeling software BRANZFIRE, by converting it from a deterministic to a probabilistic model. One component of this work is the development of a radiative fire spread submodel for which a suitable ignition criterion method is needed. This paper provides details of that ignition criterion procedure and its implementation into the submodel. A list of requirements that the ignition methodology had to satisfy was established. Of the many different piloted ignition models available, the Flux–Time Product technique, and its associated ignition criterion, was selected to be incorporated into the fire spread submodel. This method provides a practical engineering approximation of when a secondary fuel item that is subjected to incident radiation will ignite that is commensurate with the accuracy of the overall model. Primarily to demonstrate the use of the technique in the submodel, a series of ignition experiments were conducted on a single example of upholstered furniture using the Cone Calorimeter apparatus, with specimens tested in both the horizontal and vertical orientation, under piloted and auto ignition conditions. The experimental incident radiation and time‐to‐ignition data, for the piloted ignition mode, was analyzed using a modified Flux–Time Product correlation procedure. To deal with the auto ignition mode, an empirical approximation, based on the modified Flux–Time Product procedure, is proposed. Data for use in the submodel was therefore also derived for the auto ignition mode, based on an experimental determination of the minimum ignition flux. Copyright © 2010 John Wiley & Sons, Ltd.     

Flow front advancement during composite processing: predictions from numerical filling simulation tools in comparison with real‐world experiments

Liquid composite molding (LCM) techniques are innovative manufacturing processes for processing fiber reinforced polymer parts used e.g. for aerospace structures. Thereby the reinforcing material is placed in a mold and infiltrated with a low viscosity polymer matrix. Increasing production rates as well as part complexity lead to high production risks such as air inclusions or incomplete mold filling. Numerical mold filling simulations are promising tools enabling the composite manufacturing engineer to detect dry spots in the mold and find the optimal positions of the resin entry and ventilation system at an early process development stage. Today, different numerical models and software packages are available for modeling the flow through the reinforcing structure for visualization of the flow behavior. The goal of this study is the systematic comparison of two different software packages, namely PAM‐RTM^® and OpenFOAM. Both software tools are operated as they are commonly foreseen. Real world experiments under real process conditions are the basis for the assessment of the numerical predictions. The resin transfer molding (RTM) experiments are executed in a tool with a transparent upper mold half in order to see the flow front advancement. POLYM. COMPOS., 37:2782–2793, 2016. © 2015 Society of Plastics Engineers     

The dielectric properties of whey protein as indicators of change in polymer mobility

The dielectric properties of whey proteins were measured at 30–90°C, 36–75% moisture and changing salt concentrations to determine the effects of these variables on the dielectric properties. The dielectric properties were found to be more sensitive to different changes in mobility occurring during hydration than were viscosity measurements. The dielectric properties were also sensitive to the changes in water and protein mobility that occurred during protein denaturation. Theoretical heating rates based on the measured dielectric properties were compared to heating rates calculated assuming the dielectric properties retained their room temperature values and were found to differ by 0–8.5%, illustrating the minor importance of using temperature dependent values in modeling. The dielectric properties also were found to be dependent on both the concentration and type of ions present.     

Hydride Vapor-Phase Epitaxy of c-Plane AlGaN Layers on Patterned Sapphire Substrates

Growth of Al _x Ga_1?x N layers by hydride vapor-phase epitaxy on patterned sapphire substrates is investigated. The pattern consists of honeycombs which by their orientation and size promote the formation of coalesced c-plane-oriented Al _x Ga_1?x N layers with reduced crack density. The orientation of parasitic crystallites in the honeycomb openings is investigated using scanning electron microscopy and electron back-scatter diffraction. Crystallites with their [ $ \bar{1} $ $ \bar{1} $ .0] and [52.3] directions parallel to the vertical growth direction of the Al_0.3Ga_0.7N layer are observed and successfully overgrown by a 20-μm-thick fully coalesced c-plane-oriented layer.     

The Electron Capture ^{163}Ho Experiment ECHo

The determination of the absolute scale of the neutrino masses is one of the most challenging present questions in particle physics. The most stringent limit, \(m(\bar{\nu }_{\mathrm {e}})< 2\)  eV, was achieved for the electron anti-neutrino mass. Different approaches are followed to reach a sensitivity on neutrino masses in the sub-eV range. Among them, experiments exploring the beta decay or electron capture of suitable nuclides can provide information on the electron neutrino mass value. We present the electron capture \(^{163}\) Ho experiment ECHo, which aims to investigate the electron neutrino mass in the sub-eV range by means of the analysis of the calorimetrically measured energy spectrum following electron capture in \(^{163}\) Ho. A high precision and high statistics spectrum will be measured with arrays of metallic magnetic calorimeters. We discuss some of the essential aspects of ECHo to reach the proposed sensitivity: detector optimization and performance, multiplexed readout, \(^{163}\) Ho source production and purification, as well as a precise theoretical and experimental parameterization of the calorimetric EC spectrum including in particular the value of \(Q_{\mathrm {EC}}\) . We present preliminary results obtained with a first prototype of single channel detectors as well as a first 64-pixel chip with integrated micro-wave SQUID multiplexer, which will already allow to investigate \(m(\nu _{\mathrm {e}})\) in the eV range.     

A Microkelvin Magnetic Flux Noise Thermometer

Due to its non-driven nature, noise thermometry intrinsically is the method of choice when minimal heat input during the temperature measurement is required. Our noise thermometer, experimentally characterized for temperatures between 42  ${{\upmu }}$ K and 0.8 K, is a magnetic Johnson noise thermometer. The noise source is a cold-worked high purity copper cylinder, 5 mm in diameter and 20 mm long. The magnetic flux fluctuations generated by the electrons’ Brownian motion is measured inductively by two dc-SQUID magnetometers simultaneously. Cross-correlation of the two channels leads to reduction of parasitic noise by more than one order of magnitude which allows for measuring the tiny noise powers at microkelvin temperatures.     

A double-masked comparison of Naprelan and nabumetone in osteoarthritis of the knee. Naprelan Study Group

The efficacy and safety of Naprelan (naproxen sodium) 1000 mg once daily (QD) and nabumetone 1500 mg QD were compared in a multicenter, randomized, parallel-group, placebo-controlled, double-masked, 4-week study of adult outpatients with active osteoarthritis (OA) of the knee. Nabumetone 1500 mg was chosen for comparison because it is commonly prescribed in a QD dosing regimen for OA. After a washout period free of nonsteroidal anti-inflammatory drugs, 279 patients were enrolled and assigned randomly to treatment with either Naprelan 1000 mg QD (n = 92), nabumetone 1500 mg QD (n = 93), or placebo (n = 94). All treatments were evaluated for efficacy and safety at baseline and at weeks 2 and 4 of the treatment period or at discontinuation. Demographic characteristics were comparable among all treatment groups. As might be expected in a study of OA of the knee, a majority of patients enrolled were women (68.8%), and many were obese (mean weight, 195.6 lb; mean height, 66 in). Significantly fewer patients (13) treated with Naprelan prematurely discontinued the study than did patients treated with placebo (27); there was a lower rate of discontinuation for insufficient therapeutic effect in the Naprelan group compared with the nabumetone and placebo groups. Using an intent-to-treat model, the overall distribution of scores in all three primary efficacy assessments (investigator's global assessment of OA, patient's global assessment of OA, and walking pain) at week 2 and at the last visit was significantly better for the Naprelan group compared with both the nabumetone and placebo groups. The mean improvement from baseline was also significant for Naprelan compared with the nabumetone and placebo groups for all three assessments at week 2 and for investigator's global assessment of OA and walking pain at the last visit. The nabumetone-treated group showed significant improvement over the placebo-treated group in only one primary assessment: mean change from baseline in patient's global assessment of OA at week 2. At week 2, significant differences favoring Naprelan versus nabumetone and placebo were measured in overall distribution of scores for joint tenderness and nighttime pain. Distribution of quality of sleep and inactivity stiffness scores also improved relative to placebo at week 2. At the last visit, nighttime pain scores were still significantly better for patients receiving Naprelan versus nabumetone and placebo. Patients receiving nabumetone had statistically significant improvement from baseline in inactivity stiffness compared with placebo at week 2. There were no clinically important differences among treatment groups in the occurrence of adverse events or laboratory abnormalities. The results of this 4-week study of Naprelan 1000 mg QD compared with nabumetone 1500 mg QD demonstrate at least equal efficacy (superior efficacy was demonstrated for several parameters) and equal safety in adult outpatients with active OA of the knee.     

Management of recurrent penile cancer following partial or total penectomy

The initial management of localized penile carcinoma determines the probability of recurrence. Although potentially disfiguring, the management of recurrent carcinoma of the penis requires aggressive surgical resection of both the primary lesion and nodal sites to effect the best chance for long-term survival.