Flame heights and charring on a particle board – An experimental study

Vertically oriented particle-board samples were exposed to external venting flames to study the fire spread and charring behaviour along a timber façade. Variation in flame height and the height, volume, area, density, and depth of the char layer were studied to determine the impact of heat-release rate and experiment duration. There was a peak flame height after which the flame returned to steady height approximately equal to the value before the ignition of the particle board and flame heights with inert panels. Flames did not spread to the top of the panel with increased experiment duration. Char height and area were found to increase with heat-release rate but were not affected significantly by experiment duration. Char depth and volume increased with both experiment duration and heat-release rates. Char density decreased with increased experiment duration and heat-release rate.publishedVersio

Enabling Large-Scale Carbon Capture, Utilisation, and Storage (CCUS) Using Offshore Carbon Dioxide (CO2) Infrastructure Developments - A Review

Presently, the only offshore project for enhanced oil recovery using carbon dioxide, known as CO2-EOR, is in Brazil. Several desk studies have been undertaken, without any projects being implemented. The objective of this review is to investigate barriers to the implementation of large-scale offshore CO2-EOR projects, to identify recent technology developments, and to suggest non-technological incentives that may enable implementation. We examine differences between onshore and offshore CO2-EOR, emerging technologies that could enable projects, as well as approaches and regulatory requirements that may help overcome barriers. Our review shows that there are few, if any, technical barriers to offshore CO2-EOR. However, there are many other barriers to the implementation of offshore CO2-EOR, including: High investment and operation costs, uncertainties about reservoir performance, limited access of CO2 supply, lack of business models, and uncertainties about regulations. This review describes recent technology developments that may remove such barriers and concludes with recommendations for overcoming non-technical barriers. The review is based on a report by the Carbon Sequestration Leadership Forum (CSLF).publishedVersio

Reliability and concurrent validity of the International Physical Activity Questionnaire short form among pregnant women

Background: The International Physical Activity Questionnaire short-form (IPAQ-SF) is frequently used to assess physical activity (PA) level in the general adult population including pregnant women. However, the reliability and validity of the questionnaire in pregnancy is unknown. Therefore, the aims of the present study were to investigate test-retest reliability and concurrent validity of IPAQ-SF among pregnant women, and whether PA is reported differently among those who fulfill (active) vs. do not fulfill (inactive) recommendations of ≥150 min of weekly moderate intensity PA in pregnancy. Method: Test-retest reliability was examined by answering IPAQ-SF twice, two weeks apart (n = 88). To assess validity, IPAQ-SF was compared to the physical activity monitor SenseWear Armband® (SWA) (n = 64). The participants wore SWA for 8 consecutive days before answering IPAQ-SF. PA level was reported as time spent in moderate-, vigorous- and moderate-to-vigorous intensity PA (MPA, VPA and MVPA) corresponding to the cut-off points 3–6, >6 and >3 Metabolic Equivalents (METs), respectively. Results: Test-retest intraclass-correlation of MPA, VPA and MVPA ranged from 0.81-0.84 (95% Confidence Intervals: 0.69,0.90). Comparing time spent performing PA at various intensities; the mean differences and limits of agreement (±1.96 Standard Deviation) from Bland-Altman plots were−84 ± 402 min/week for MPA,−85 ± 452 min/week for MVPA and 26 ± 78 min/week for VPA, illustrating that the total group under-reported MPA by 72% and MVPA by 52%, while VPA was over-reported by 1400%. For the inactive group corresponding numbers were 44 ± 327 min/week for MPA, 52 ± 355 min/week for MVPA and 16 ± 33 min/week for VPA, illustrating that the inactive group over-reported MPA by 13% and MVPA by 49%, while VPA was not detected by SWA, but participants reported 16 min of VPA/week. In contrast, corresponding numbers for the active group were−197 ± 326 min/week for MPA,−205 ± 396 min/week for MVPA and 35 ± 85 min/week for VPA, illustrating that the active group under-reported MPA by 81% and MVPA by 60%, while they over-reported VPA by 975%. Conclusion: IPAQ-SF had good test-retest reliability, but low to fair concurrent validity for MPA, VPA and MVPA compared to an objective criterion measure among pregnant women. Further, women fulfilling PA guidelines in pregnancy under-reported, while inactive women over-reported PA level.publishedVersionNivå

(Table 1) Age determination of sediment profile JM96-1225

The paleoceanography in the Denmark Strait, North Atlantic, is reconstructed based on down core analysis of planktonic foraminifera, carbon and oxygen isotopes, carbonate, and ice rafted debris (IRD). The stratigraphy spans 57 to 6 calibrated (cal) ka years and reveals sea surface temperatures that covary with Greenland ice core temperatures throughout marine isotope stages (MIS) 3 and 2. Planktonic d18O minima, interpreted as meltwater events, follow sea surface warming. IRD from both the Greenland and Iceland Ice Sheets was delayed by ~2 ka relative to the North Atlantic Heinrich events. Ventilation of bottom water was mostly sustained through open ocean convection associated with North Atlantic Deep Water production or by convection of glacial North Atlantic Intermediate Water, except for two episodes at ~54 cal ka (MIS 3.31) and 18–15 cal ka (termination I). During these two periods we suggest that deep water ventilation was accomplished mainly by brine formation

Flame heights and charring on a particle board – An experimental study

Vertically oriented particle-board samples were exposed to external venting flames to study the fire spread and charring behaviour along a timber façade. Variation in flame height and the height, volume, area, density, and depth of the char layer were studied to determine the impact of heat-release rate and experiment duration. There was a peak flame height after which the flame returned to steady height approximately equal to the value before the ignition of the particle board and flame heights with inert panels. Flames did not spread to the top of the panel with increased experiment duration. Char height and area were found to increase with heat-release rate but were not affected significantly by experiment duration. Char depth and volume increased with both experiment duration and heat-release rates. Char density decreased with increased experiment duration and heat-release rate

(Table T1) Calcium carbonate content of sediments from ODP Leg 172 sites

Visual-domain diffuse reflectance data collected aboard the JOIDES Resolution with the Minolta spectrometer CM-2002 during Ocean Drilling Program Leg 172 have been used to estimate successfully the carbonate content of sediments. Calibration equations were developed for each site and for each lithostratigraphic unit (or subunit at Site 1063) using multiple linear regression on raw as well as pretreated reflectance spectra (i.e., first-order derivation and squaring of raw reflectance spectra) for a total of 4141 direct carbonate measurements. The root-mean-square errors of 4% to 7% are within the range of previous estimates using diffuse reflectance data and are acceptable for the general extensive range of carbonate contents (i.e., 0-70 wt%) that characterize sedimentation at Leg 172 sites

Onset of smoldering fires in storage silos: Susceptibility to design, scenario, and material parameters

Biomass fuels in large storage units are prone to self-heating and ignition causing smoldering fires. Here, the susceptibility of such ignition processes to parameters is explored through small-scale experiments. In a silo geometry, wood pellets samples of size 0.75 to 1.5 kg were heated from below to initiate smoldering, while the top was open, allowing convective exchange of gases between the porous sample and the surroundings. The thermally insulated sidewalls reduce the heat flow in lateral direction in a similar way that additional pellets material would do in a larger set-up. Thus, the present experimental set-up mimics a much larger system in lateral direction. After heating was terminated, the procedure led to self-sustaining smoldering or spontaneous cooling, depending on parameters. The transition zone between smoldering and non-smoldering was explored under variation in sample size, imposed heating, pellets type, and height of sample container. Logistic regression was applied to fit the experimental data to a model. The model predicted the probability of an experiment to result in either smoldering or non-smoldering under variation in parameters – and the parameters were sorted according to importance. The duration of the external heating was found to be the most influential parameter. For risk assessments in connection with large biomass fuel storage units, this result indicates that the temperature increase could be more important than the size and geometry of the storage unit and the stored material type