Distributed Ship Service Systems Architecture in The Early Stages of Designing Physically Large and Complex Vessels: The Submarine Case

In the initial sizing of complex vessels, where recourse to type ship design can be overly restrictive, one crucial set of design features has traditionally been poorly addressed. This is the estimation of the weight and space demands of the various Distributed Ship Services Systems (DS3), which include different types of commodity services beyond those primarily associated with the ship propulsion system. In general, naval vessels are typified by extensive and densely engineered DS3, with the modern naval submarine being at the extreme of dense outfitting. Despite this, the ability for the concept designer to consider the impact of different configurations for the DS3 arrangements has not been readily addressed in concept design. This paper describes ongoing work at University College London (UCL) to develop a novel DS3 synthesis approach utilising computer tools, such as Paramarine™, MATLAB®, and CPLEX®, which provide the concept designer with a quantitative network-based evaluation to enable DS3 space and weight inputs early in the design process. The results of applying the approach to a conventional submarine case study indicate quantitative insights into early DS3 sizing can be obtained. The paper concludes with likely developments in concluding the research study

PVC Sheathed Electrical Cable Fire Smoke Toxicity

The cone calorimeter, under free and restricted ventilation conditions, was used to investigate the toxic emissions from PVC cable fires. Toxic gases were measured using direct high temperature gas sampling from the exit of the cone calorimeter with a short chimney attached to the exit from the electrical cone. Toxic species CO and HCl were identified as a function of time using a heated Gasmet FTIR. The particle number was determined using the Cambustion DMS500 fast response particle sizer with a diluted sample taken from the diluted cone calorimeter exhaust flow at the same location as the optical obscuration smoke meter. The HCl concentrations from the Chlorine in the PVC sheath demonstrated HCl levels well above the LC50 concentration for HCl. The restricted ventilation reduced the peak fire heat release rate and the peak toxicity and HCl occurred later than for free ventilation. The equivalence ratio in the gases from the combustion zone, were both rich at 1.5 for free ventilation and 1.3-1.4 for restricted ventilation. The toxicity results showed the classic phases of compartment fires: growth, steady state burning and then fire decay. After flaming combustion was extinguished, slow char combustion continued with high CO emissions. The particle size distribution showed peak particle number, PN, nuclei mode particles at 10 nm and an accumulation mode at 100 nm. The number of particles at 10 nm for free and restricted ventilation were extremely high and showed that the freely ventilated fires had the highest PN, but later in the fire the restricted ventilation PN were higher. Nano-particle emissions < 50 nm from PVC fires are a health hazard that is currently unrecognized and unregulated

Smoke Particle Size Distribution in Pine Wood Fires

There is a growing concern about the impact of ultra- fine particulates released from fires on the health of humans in fires and the related environmental pollution. However, there is no requirement to measure particle mass or number from legislated test fires and hence there is minimum information in the literature on this toxic hazard in fires. This work compares particulates generated from freely ventilated and restricted ventilation pine wood fires using the cone calorimeter. The standard cone calorimeter with freely ventilated combustion was modified by adding a discharge pipe to the cone heater that enabled direct fire product sampling from the cone outlet. The controlled atmosphere cone calorimeter was used for the restricted ventilation fire with metered air fed to the enclosure around the test area. Both tests used a radiant heat flux of 35kW/m2. Real-time particulate number and size distribution were measured using the Cambustion DMS 500 particle electrical mobility spectrometer. The particulate size distribution showed a peak of ultra-fine aerosol particles of <100 nm in the early stage of the fire development and then changed to the larger size (100-1000 nm) with a peak of 200 nm as the fire progressed. The restricted ventilation fire generated more particles. There were high numbers of 20 nm particles throughout the fire and these have the greatest health risks. Toxic gases were also measured from the raw exhaust gases using a heated Gasmet FTIR gas analyser

Cardiac magnetic resonance imaging for the detection of myocardial involvement in granulomatosis with polyangiitis

The prevalence of undiagnosed cardiac involvement in granulomatosis with polyangiitis (GPA) is unknown. In this prospective study we investigated the utility of cardiovascular magnetic resonance (CMR) to identify myocardial abnormalities in GPA and their correlation with disease phenotype. Twenty-six patients with GPA and no cardiovascular disease or diabetes mellitus underwent contrast-enhanced CMR, including late gadolinium-enhancement (LGE), T1-mapping for native T1 and extra-cellular volume (ECV) quantification for assessment of myocardial fibrosis, cine imaging and tissue tagging for assessment of left ventricular (LV) function. Twenty-five healthy volunteers (HV) with comparable age, sex, BMI and arterial blood pressure served as controls. Patients with GPA had similar cardiovascular risk profile to HV. A focal, non-ischaemic LGE pattern of fibrosis was detected in 24% of patients and no controls (p = 0.010). Patients with myocardial LGE were less frequently PR3 ANCA (7% vs 93%, p = 0.007), and had involvement of the lower respiratory tract and skin. LGE scar mass was higher in patients presenting with renal involvement. Native T1 and ECV were higher in patients with GPA than HV; ECV was higher in those with relapsing disease, and native T1 was inversely associated with PR3 ANCA (β = − 0.664, p = 0.001). Peak systolic strain was slightly reduced in GPA compared to controls; LV ejection function was inversely correlated with disease duration (β = − 0.454, p = 0.026). Patients with GPA have significant myocardial abnormalities on CMR. ANCA, systemic involvement and disease severity were associated with myocardial fibrosis. CMR could be a useful tool for risk stratification of myocardial involvement in GPA

Toxic Gas Emissions from Plywood Fires

Toxic emissions from four construction plywoods were investigated using a freely ventilated cone calorimeter with raw predilution hot gas sampling. Each plywood sample was exposed to the conical heater of the cone calorimeter radiating at 35 kw/m². Rich mixtures occurred in some of the tests, these rich mixtures produced high concentrations of toxic gases. The 4 samples had different peak heat release rate HRR, but similar steady state HRR. The elemental analysis of the four samples showed that they had different nitrogen content, indicating different glues were used. Plywood B had the highest N content of 6.43%, which resulted in the highest HCN concentration. The most important toxic species were CO, HCN, acrolein, formaldehyde and benzene on both an LC₅₀ and COSHH₁₅min basis

Cardiovascular effects of biological versus conventional synthetic disease-modifying antirheumatic drug therapy in treatment-naïve, early rheumatoid arthritis

Objectives To determine whether patients with early rheumatoid arthritis (ERA) have cardiovascular disease (CVD) that is modifiable with disease-modifying antirheumatic drug (DMARD) therapy, comparing first-line etanercept (ETN) + methotrexate (MTX) with MTX strategy. Methods Patients from a phase IV ERA trial randomised to ETN+MTX or MTX strategy±month 6 escalation to ETN+MTX, and with no CVD and maximum one traditional risk factor underwent cardiovascular magnetic resonance (CMR) at baseline, years 1 and 2. Thirty matched controls underwent CMR. Primary outcome measure was aortic distensibility (AD) between controls and ERA, and baseline to year 1 AD change in ERA. Secondary analyses between and within ERA groups performed. Additional outcome measures included left ventricular (LV) mass and myocardial extracellular volume (ECV). Results Eighty-one patients recruited. In ERA versus controls, respectively, baseline (geometric mean, 95% CI) AD was significantly lower (3.0×10−3 mm Hg−1 (2.7–3.3) vs 4.4×10−3 mm Hg−1 (3.7–5.2), p<0.001); LV mass significantly lower (78.2 g (74.0–82.7), n=81 vs 92.9 g (84.8–101.7), n=30, p<0.01); and ECV increased (27.1% (26.4–27.9), n=78 vs 24.9% (23.8–26.1), n=30, p<0.01). Across all patients, AD improved significantly from baseline to year 1 (3.0×10−3 mm Hg−1 (2.7–3.4) to 3.6×10–3 mm Hg−1 (3.1–4.1), respectively, p<0.01), maintained at year 2. The improvement in AD did not differ between the two treatment arms and disease activity state (Disease Activity Score with 28 joint count)-erythrocyte sedimentation rate-defined responders versus non-responders. Conclusion We report the first evidence of vascular and myocardial abnormalities in an ERA randomised controlled trial cohort and show improvement with DMARD therapy. The type of DMARD (first-line tumour necrosis factor-inhibitors or MTX) and clinical response to therapy did not affect CVD markers. Trial registration number ISRCTN: ISRCTN89222125; ClinicalTrials.gov: NCT01295151

Cardiovascular MRI evidence of reduced systolic function and reduced LV mass in rheumatoid arthritis: impact of disease phenotype

The accelerated risk of cardiovascular disease (CVD) in Rheumatoid Arthritis (RA) requires further study of the underlying pathophysiology and determination of the at-risk RA phenotype. Our objectives were to describe the cardiac structure and function and arterial stiffness, and association with disease phenotype in patients with established) RA, in comparison to healthy controls, as measured by cardiovascular magnetic resonance imaging (CMR). 76 patients with established RA and no history of CVD/diabetes mellitus were assessed for RA and cardiovascular profile and underwent a non-contrast 3T-CMR, and compared to 26 healthy controls. A univariable analysis and multivariable linear regression model determined associations between baseline variables and CMR-measures. Ten-year cardiovascular risk scores were increased in RA compared with controls. Adjusting for age, sex and traditional cardiovascular risk factors, patients with RA had reduced left ventricular ejection fraction (mean difference − 2.86% (− 5.17, − 0.55) p = 0.016), reduced absolute values of mid systolic strain rate (p < 0.001) and lower late/active diastolic strain rate (p < 0.001) compared to controls. There was evidence of reduced LV mass index (LVMI) (− 4.56 g/m2 (− 8.92, − 0.20), p = 0.041). CMR-measures predominantly associated with traditional cardiovascular risk factors; male sex and systolic blood pressure independently with increasing LVMI. Patients with established RA and no history of CVD have evidence of reduced LV systolic function and LVMI after adjustment for traditional cardiovascular risk factors; the latter suggesting cardiac pathology other than atherosclerosis in RA. Traditional cardiovascular risk factors, rather than RA disease phenotype, appear to be key determinants of subclinical CVD in RA potentially warranting more effective cardiovascular risk reduction programs

SUMO chain formation is required for response to replication arrest in S. pombe

SUMO is a ubiquitin-like protein that is post-translationally attached to one or more lysine residues on target proteins. Despite having only 18% sequence identity with ubiquitin, SUMO contains the conserved betabetaalphabetabetaalphabeta fold present in ubiquitin. However, SUMO differs from ubiquitin in having an extended N-terminus. In S. pombe the N-terminus of SUMO/Pmt3 is significantly longer than those of SUMO in S. cerevisiae, human and Drosophila. Here we investigate the role of this N-terminal region. We have used two dimensional gel electrophoresis to demonstrate that S. pombe SUMO/Pmt3 is phosphorylated, and that this occurs on serine residues at the extreme N-terminus of the protein. Mutation of these residues (in pmt3-1) results in a dramatic reduction in both the levels of high Mr SUMO-containing species and of total SUMO/Pmt3, indicating that phosphorylation of SUMO/Pmt3 is required for its stability. Despite the significant reduction in high Mr SUMO-containing species, pmt3-1 cells do not display an aberrant cell morphology or sensitivity to genotoxins or stress. Additionally, we demonstrate that two lysine residues in the N-terminus of S. pombe SUMO/Pmt3 (K14 and K30) can act as acceptor sites for SUMO chain formation in vitro. Inability to form SUMO chains results in aberrant cell and nuclear morphologies, including stretched and fragmented chromatin. SUMO chain mutants are sensitive to the DNA synthesis inhibitor, hydroxyurea (HU), but not to other genotoxins, such as UV, MMS or CPT. This implies a role for SUMO chains in the response to replication arrest in S. pomb

Crack-Like Processes Governing the Onset of Frictional Slip

We perform real-time measurements of the net contact area between two blocks of like material at the onset of frictional slip. We show that the process of interface detachment, which immediately precedes the inception of frictional sliding, is governed by three different types of detachment fronts. These crack-like detachment fronts differ by both their propagation velocities and by the amount of net contact surface reduction caused by their passage. The most rapid fronts propagate at intersonic velocities but generate a negligible reduction in contact area across the interface. Sub-Rayleigh fronts are crack-like modes which propagate at velocities up to the Rayleigh wave speed, VR, and give rise to an approximate 10% reduction in net contact area. The most efficient contact area reduction (~20%) is precipitated by the passage of slow detachment fronts. These fronts propagate at anomalously slow velocities, which are over an order of magnitude lower than VR yet orders of magnitude higher than other characteristic velocity scales such as either slip or loading velocities. Slow fronts are generated, in conjunction with intersonic fronts, by the sudden arrest of sub-Rayleigh fronts. No overall sliding of the interface occurs until either of the slower two fronts traverses the entire interface, and motion at the leading edge of the interface is initiated. Slip at the trailing edge of the interface accompanies the motion of both the slow and sub-Rayleigh fronts. We might expect these modes to be important in both fault nucleation and earthquake dynamics.Comment: 19 page, 5 figures, to appear in International Journal of Fractur

Pine Wood Crib Fires: Toxic Gas Emissions Using a 5m3 Compartment Fire

Toxic emissions from pinewood crib fires were determined using heated FTIR gas analysis from a 5 m3 compartment fire with an air opening equivalent to 5% of the compartment cross-sectional area (V2/3) in the floor of the compartment and a vent in the ceiling layer, with the air inlet controlling the flow. A 20 mm square pine wood crib size of 400 × 400 × 260 mm was investigated. The crib was ignited using a small ethanol pool fire. The flaming fire had a peak HRR of 40 kW and average ceiling temperature of 400 °C. The fire was lean overall at the peak HRR and the fire self-extinguished through lack of air with subsequent smouldering combustion. In spite of the lean combustion in the fire, very high toxic emissions were determined with an FEC LC50 of >6. The peak toxicity occurred just before the fire self-extinguished and the key toxic emissions were CO and formaldehyde for deaths, while formaldehyde and acrolein were the most important for impairment of escape