Philip Loldrup Fosbøl

Transfer of oxygen across the gas-liquid interface in gas-liquid fluidised beds

Abstract This paper describes an experimental investigation of the rate of transfer of oxygen from the gas phase to the liquid phase in gas-liquid fluidised beds of glass ballotini of 1-mm and 6-mm dia. The influence of gas and liquid flow velocities, of the presence of solid particles, and of the particle size has been examined. The variation of the mass transfer coefficient with the distance from the gas distributor was also studied. The results have been qualitatively compared with information on bubble size, gas-liquid interfacial area, and other relevant aspects of fluid flow.

Conversion of Cardiovascular Conference Abstracts to Publications

Background—The transition of scientific knowledge from discovery into practice is less than ideal. A key step in this translation occurs when presentations from major meetings are published in peer-reviewed literature, yet the completeness and speed of this process are not known. We performed a systematic and automated evaluation of rates, timing, and correlates of publication from scientific abstracts presented at 3 major cardiovascular conferences. Methods and Results—Using an automated computer algorithm, we searched the ISI Web of Science to identify peer-reviewed publications of abstracts presented at the American Heart Association (AHA), American College of Cardiology (ACC), and European Society of Cardiology (ESC) scientific sessions from 2006 to 2008. We compared abstract publication rates and journal impact factor between the 3 meetings using multivariable logistic regression modeling. From 2006 to 2008, 11 365, 5005, and 10 838 abstracts were presented at the AHA, ACC, and ESC meetings, respectively. Overall, 30.6% of presented abstracts were published within 2 years of the conference; ranging from 34.5% for AHA to 29.5% for ACC to 27.0% for ESC (P<0.0001). Five years after conference presentation in 2005, these rates had risen slightly to 49.7% for AHA, 42.6% for ACC, and 37.6% for ESC (P<0.0001). After adjustment for abstract characteristics and contributing countries, abstracts presented at the AHA meeting remained more likely for publication relative to the ESC (adjusted odds ratio, 1.24; 95% confidence interval, 1.16–1.34) and the ACC (adjusted odds ratio, 1.20; 95% confidence interval, 1.11–1.29). Median impact factors for subsequent publications varied from 4.8 (interquartile range, 3.8–10.1) for AHA to 4.0 (interquartile range, 3.1–7.5) for ACC and 3.9 (quartile 1–3, 2.5–5.8) for ESC (P for difference between groups <0.01). Clinical science and population science were less likely to be published compared with basic science. Conclusions—One third of abstracts were translated into publications by 2 years after presentation and less than one half by 5 years after presentation. Our findings suggest that efforts to understand the barriers to publication and to facilitate the rapid dissemination of new knowledge are needed to speed up the transition of scientific discovery into clinical practice.

Review and recommended thermodynamic properties of FeCO3

Abstract An extensive review of entropy, enthalpy of formation and Gibbs energy of formation, heat capacity, aqueous solubility and solubility constant of FeCO3 is given. A consistent set of thermodynamic properties for FeCO3 and relevant aqueous species is selected and recommended for use. Speciation schemes for aqueous FeCO3 are reviewed and evaluated. Issues related to supersaturation of FeCO3 are discussed. Works on the thermal decomposition of FeCO3 are presented and an overview of measured solubility and synthesis of FeCO3 is given.

A dynamic mathematical model for packed columns in carbon capture plants

In this paper, we present a dynamic mathematical model for the absorption and desorption columns in a carbon capture plant. Carbon capture plants must be operated in synchronization with the operation of thermal power plants. Dynamic and flexible operation of the carbon capture plant is important as thermal plants must be operated very flexibly to accommodate large shares of intermittent energy sources such as wind and solar in the energy system. To facilitate such operation, dynamic models for simulation, optimization and control system design are crucial. The dynamic model developed in this paper is suitable for gas-liquid packed columns, e.g. for CO2 absorption and desorption. The model is based on rigorous thermodynamic and conservation principles and it is set up to preserve these properties upon numerical integration in time. The developed model is applied for CO2 absorption and desorption simulation using monoethanolamine (MEA) and piperazine (PZ) as solvent. MEA is considered as the base-case solvent in the carbon capture business. The effect of changes in the flue gas flow rate and changes in the available steam are investigated to determine their influence on the performance of the capture process. The response of the model is shown in terms of capture efficiency and purity of the CO2 product stream. The model is aimed for rigorous dynamic simulation in the context of optimization and control strategy development.

Rate and Predictors of the Conversion of Abstracts Presented at the Canadian Cardiovascular Congress Scientific Meetings to Full Peer-Reviewed Publications

The rate of conversion of abstracts presented at scientific meetings into peer-reviewed published manuscripts is an important metric for medical societies, because it facilitates translation of scientific knowledge into practice. We determined the rate and predictors of conversion of scientific abstracts presented at the Canadian Cardiovascular Congress (CCC) from 2006 to 2010 into peer-reviewed article publications within 2 years of their initial presentation. Using a previously validated computer algorithm, we searched the International Statistical Institute Web of Science to identify peer-reviewed full manuscript publications of these abstracts. A multivariable logistic regression was used to identify independent factors associated with successful publication. From 2006 to 2010, 3565 abstracts were presented at the CCC. Overall 24.1% of presented abstracts were published within 2 years of the conference. Mean impact factor for publications was 5.2 (range, 0.4-53.2). The type of presentation (for poster vs oral; odds ratio, 0.71; 95% confidence interval, 0.60-0.83; P < 0.001) and category of presentation (P < 0.001) were significantly associated with successful publication. Late breaking abstracts and those related to cancer and clinical sciences were more likely to be published, compared with prevention, vascular biology, and pediatrics. In conclusion, the publication rate at the CCC is only marginally lower than that reported for large international North American and European cardiology conferences (30.6%). Efforts should focus on several identified barriers to improve conversion of abstracts to full report publication.

Determining Optimum Aging Time Using Novel Core Flooding Equipment

(11/12/2018) Determining optimum aging time using novel core flooding equipment New methods for enhanced oil recovery are typically developed using core flooding techniques. Establishing reservoir conditions is essential before the experimental campaign commences. The realistic oil-rock wettability can be obtained through optimum aging of the core. Aging time is affected by temperature, crude oil, formation brine, and coreplug lithology. Minimum time can significantly reduce the experimental cost while insufficient aging time can result in false conclusions. Real-time online resistivity measurements of coreplugs are presented and a novel method is introduced for determining the optimum aging time regardless of variations in crude oil, rock, and brine properties. State of the art core flooding equipment has been developed that can be used for consistently determining the resistivity of the coreplug during aging and waterflooding using advanced data acquisition software. In the proposed equipment, independent axial and sleeve pressure can be applied to mimic stresses at reservoir conditions. 10 coreplugs (four sandstones and six chalk samples) from the North Sea have been aged for more than 408 days in total and more than 29000 resistivity data points have been measured to consistently investigate the change of wettability during aging. At 60°C and 100 bars a homogeneous sandstone coreplug attained optimized wettability after 5 days, a heterogeneous coreplug required 30 days of aging. Chalk coreplugs needed 45 days of aging. This shows that coreplugs originating from the same field, when aged at equivalent conditions can have significantly different aging times because of minor variations in the coreplug properties. No fixed aging time can be recommended on the other hand a method is recommended which can determine the extent of aging. Coreplug aging patterns were studied for variation in pressure (20 to 130 bar) and temperature (60 to 130°C).

Fine Formation During Brine-Crude Oil-Calcite Interaction in Smart Water Enhanced Oil Recovery for Caspian Carbonates

Recovery for Caspian Carbonates DTU Orbit (09/11/2017) Fine Formation During Brine-Crude Oil-Calcite Interaction in Smart Water Enhanced Oil Recovery for Caspian Carbonates Modified sea water has been shown to affect the oil recovery fraction considerably during secondary and tertiary waterfloods. Available soluble potential ions (i.e. Ca2+, Mg2+ & SO4 2-) in the interacting waterflood (ITW) are suggested to play a key role in increasing the displacement efficiency of oil. In previous studies, compositions of injected waterfloods (IJW) have been correlated to the observed oil recovery. This study highlights differences between IJW and ITW for different studies reported in literature.

Importance of fines in smart water enhanced oil recovery (SmW-EOR) for chalk outcrops

DTU Orbit (19/09/2019) Importance of fines in smart water enhanced oil recovery (SmW-EOR) for chalk outcrops In SmW-EOR it is generally believed that precipitation of brines must be avoided since it can have a negative impact on the SmW sweep efficiency. But substitution of Mg2+ by Ca2+ on calcite surfaces (a well-accepted phenomenon) can change the brine combination and enhance the possibility of fine formation at speciation. Considering this phenomenon we analyze the possibility of fines formation and its influence in SmW-EOR. To calculate the brine speciation and the amount of precipitate formed at different pressure and temperature conditions, we use the Extended UNIQUAC model for 61 SmW-EOR experiments reported in literature. Both the amount of available soluble SO4 2(aq) in the solution and the amount of CaSO4 precipitation has been calculated and correlated to the corresponding oil recovery.

Response to Letters Regarding Article, “Conversion of Cardiovascular Conference Abstracts to Publications”

Winnik et al comment in a letter1 about our recent article on converting Scientific Session abstracts into peer-reviewed publications.2 Winnik et al conducted and reported a very comprehensive manual study on this same topic using data from ≈1000 randomly selected abstracts from the European Society of Cardiology Scientific Sessions.3 Their study was published when our manuscript was in the review process for Circulation . The results reported by Winnik et al were similar to ours, although in a smaller sample. We sincerely regret that we were not aware of and therefore did not acknowledge the fine work by Winnik et al. We find the results intriguing, particularly the link between abstract grading and subsequent publication likelihood. Evidence is accumulating for a suboptimal conversion of science from abstracts to …

Container Closure Integrity Testing – Method Development for Freeze Dryed Products Using laser based Headspace Oxygen Analysis

The regulatory expectations introduced by the U.S. Food and Drug Administration in 1999, ICH Q5C, the revised draft of Annex 1, Eudralex volume 4 for consultation, and the recent update of USP general chapters 1207.1 and 1207.2 regarding container closure integrity (CCI) testing have created a need for further development of testing methods, although there are no universally accepted methods to test and evaluate the CCI of a biopharmaceutical drug product. Each testing method and principle has merits and demerits. This paper will present a simple approach to be used in method validation of CCI testing based on headspace oxygen analysis for freeze-dried biopharmaceutical drug products in vials, as well as a method for testing and verifying positive control vials. The model is based on Ficks law of diffusion and is empirically corrected to account for Knudsen diffusion in smaller defect sizes. The model considers storage conditions of the vials, allowing for testing of vials stored under anaerobic and near-sealing pressure conditions and different temperature conditions, as well as testing at different time points. Using this approach based on headspace oxygen analysis, the minimum timeframe for leak detection is dependent on the volume of the object tested, but standard vial sizes have shown that leak sizes of 0.2 μm can be detected within hours of vial stoppering with the model developed. CCI testing by headspace oxygen analysis using this approach can be done quickly and non-destructively. This method can prove its effectiveness in demonstration of a protective critical barrier (CCI) for a biopharmaceutical drug product during real-time situations of manufacturing, transportation, registered storage conditions, etc. (life-cycle approach). LAY ABSTRACT: The recent update of the guideline, USP general chapters 1207.1 and 1207.2, regarding container closure integrity (CCI) testing, has created a need for further development of testing methods. The new methods applied should be deterministic, i.e., describe predefined detection limits and objective quantitative data. Deterministic leak test methods are methods for which the leakage event being detected or measured is based on phenomena that follow a predictable chain of events. At present, there is no universally accepted method to test and evaluate the CCI of a biopharmaceutical drug product. This paper will present a simple model-based method based on headspace oxygen analysis for freeze-dried biopharmaceutical drug products in vials, as well as a method for testing and verifying positive control vials. Positive controls are vials with a known defect, e.g., an inserted micropipette. The model considers storage conditions of the vials, allowing for testing of vials stored under different pressure and temperature conditions, as well as testing at different time points. CCI testing by headspace oxygen analysis using the new approach can be done quickly and without destruction of the vials. This method can prove its effectiveness in demonstration of a protective critical barrier (CCI) for a biopharmaceutical drug product during real situations of manufacturing, transportation, registered storage conditions, etc.