41 research outputs found
Combined analysis of different logs in quantification of exhumation and its implications for hydrocarbon exploration, a case study from Australia
Exhumation in the Eromanga Basin of South Australia and Queensland has been quantified using the compaction methodology. The standard method of estimating exhumation using the sonic log has been modified and the adjusted sonic, the bulk density and neutron logs, have been used to estimate exhumation. Additionally the use of a single shale has not been adopted, and seven units, ranging in age from Cretaceous to Jurassic have been analysed. All units yield similar results; and burial at depth greater than currently observed is the most likely cause of overcompaction. The use of the adjusted sonic, bulk and neutron logs have been justified. This study has major implications for hydrocarbon exploration since predicted maturation of source rocks will be greater for any given geothermal history if exhumation is incorporated in maturation modelling
Seasonal predictability of the 2010 Russian heat wave
The atmospheric blocking over eastern Europe and western Russia that
prevailed during July and August of 2010 led to the development of a
devastating Russian heat wave. Therefore the question of whether the event
was predictable or not is highly important. The principal aim of this study
is to examine the predictability of this high-impact atmospheric event on a
seasonal timescale. To this end, a set of dynamical seasonal simulations have
been carried out using an atmospheric global circulation model (AGCM). The
impact of various model initializations on the predictability of this
large-scale event and its sensitivity to the initial conditions has been also
investigated. The ensemble seasonal simulations are based on a modified
version of the lagged-average forecast method using different lead-time
initializations of the model. The results indicated that only a few
individual members reproduced the main features of the blocking system 3
months ahead. Most members missed the phase space and the propagation of the
system, setting limitations in the predictability of the event
The structural style and hydrocarbon exploration of the subthrust in the Berati Anticlinal Belt, Albania
Research trends in combinatorial optimization
Acknowledgments This work has been partially funded by the Spanish Ministry of Science, Innovation, and Universities through the project COGDRIVE (DPI2017-86915-C3-3-R). In this context, we would also like to thank the Karlsruhe Institute of Technology. Open access funding enabled and organized by Projekt DEAL.Peer reviewedPublisher PD
Atrasentan and renal events in patients with type 2 diabetes and chronic kidney disease (SONAR): a double-blind, randomised, placebo-controlled trial
Background: Short-term treatment for people with type 2 diabetes using a low dose of the selective endothelin A receptor antagonist atrasentan reduces albuminuria without causing significant sodium retention. We report the long-term effects of treatment with atrasentan on major renal outcomes. Methods: We did this double-blind, randomised, placebo-controlled trial at 689 sites in 41 countries. We enrolled adults aged 18–85 years with type 2 diabetes, estimated glomerular filtration rate (eGFR)25–75 mL/min per 1·73 m 2 of body surface area, and a urine albumin-to-creatinine ratio (UACR)of 300–5000 mg/g who had received maximum labelled or tolerated renin–angiotensin system inhibition for at least 4 weeks. Participants were given atrasentan 0·75 mg orally daily during an enrichment period before random group assignment. Those with a UACR decrease of at least 30% with no substantial fluid retention during the enrichment period (responders)were included in the double-blind treatment period. Responders were randomly assigned to receive either atrasentan 0·75 mg orally daily or placebo. All patients and investigators were masked to treatment assignment. The primary endpoint was a composite of doubling of serum creatinine (sustained for ≥30 days)or end-stage kidney disease (eGFR <15 mL/min per 1·73 m 2 sustained for ≥90 days, chronic dialysis for ≥90 days, kidney transplantation, or death from kidney failure)in the intention-to-treat population of all responders. Safety was assessed in all patients who received at least one dose of their assigned study treatment. The study is registered with ClinicalTrials.gov, number NCT01858532. Findings: Between May 17, 2013, and July 13, 2017, 11 087 patients were screened; 5117 entered the enrichment period, and 4711 completed the enrichment period. Of these, 2648 patients were responders and were randomly assigned to the atrasentan group (n=1325)or placebo group (n=1323). Median follow-up was 2·2 years (IQR 1·4–2·9). 79 (6·0%)of 1325 patients in the atrasentan group and 105 (7·9%)of 1323 in the placebo group had a primary composite renal endpoint event (hazard ratio [HR]0·65 [95% CI 0·49–0·88]; p=0·0047). Fluid retention and anaemia adverse events, which have been previously attributed to endothelin receptor antagonists, were more frequent in the atrasentan group than in the placebo group. Hospital admission for heart failure occurred in 47 (3·5%)of 1325 patients in the atrasentan group and 34 (2·6%)of 1323 patients in the placebo group (HR 1·33 [95% CI 0·85–2·07]; p=0·208). 58 (4·4%)patients in the atrasentan group and 52 (3·9%)in the placebo group died (HR 1·09 [95% CI 0·75–1·59]; p=0·65). Interpretation: Atrasentan reduced the risk of renal events in patients with diabetes and chronic kidney disease who were selected to optimise efficacy and safety. These data support a potential role for selective endothelin receptor antagonists in protecting renal function in patients with type 2 diabetes at high risk of developing end-stage kidney disease. Funding: AbbVie
Combined analysis of different logs in quantification of exhumation and its implications for hydrocarbon exploration, a case study from Australia
Exhumation in the Eromanga Basin of South Australia and Queensland has been quantified using the compaction methodology. The standard method of estimating exhumation using the sonic log has been modified and the adjusted sonic, the bulk density and neutron logs, have been used to estimate exhumation. Additionally the use of a single shale has not been adopted, and seven units, ranging in age from Cretaceous to Jurassic have been analysed. All units yield similar results; and burial at depth greater than currently observed is the most likely cause of overcompaction. The use of the adjusted sonic, bulk and neutron logs have been justified. This study has major implications for hydrocarbon exploration since predicted maturation of source rocks will be greater for any given geothermal history if exhumation is incorporated in maturation modelling
Quantification of exhumation in the Eromanga Basin and its implications for hydrocarbon exploration
Copyright © 2005 EAGE/Geological Society of LondonExhumation in the Eromanga Basin of South Australia and Queensland has been quantified using compaction methodology. All methods of estimating exhumation utilize rock properties that are affected by, and retain a memory of, burial in excess of that presently observed. The tool used for estimating the exhumation in this study is analysis of the degree of overcompaction of rock units. Since porosity describes compaction state, the sonic log, controlled strongly by the amount of porosity, is an appropriate indicator of compaction and, hence, is used for quantifying exhumation from compaction. The standard method of estimating exhumation based on the degree of overcompaction of a single shale unit has been modified, and seven units, predominantly shales ranging in age from the Cretaceous to the Jurassic, have been analysed. All units yield similar results. Burial at depth greater than currently observed is the most likely cause of overcompaction since it is unlikely that sedimentological and/or diagenetic processes are responsible for similar amounts of overcompaction in different lithologies. The results of the compaction analysis reveal that Late Cretaceous–Tertiary exhumation increases eastwards from the Patchawarra Trough, through the Gidgealpa–Merrimelia–Innamincka Trend and Nappamerri Trough into the Queensland sector of the basins. This study has major implications for hydrocarbon exploration. Predicted maturation of source rocks will be greater for any given geothermal history if exhumation is incorporated in maturation modelling. The exhumation study helps to quantify velocity anomalies associated with overcompaction. Exhumation values can also be used to improve porosity predictions of reservoir units in undrilled targets.Angelos Mavromatidis and Richard Hilli
Guidelines to study numerically and experimentally reflective insulation systems as applied to buildings
There is now widespread acceptance that insulation of the building's envelope plays a key role in efficient reduction of their energy consumption. Consequently, in the course of scientific and technological development, reflecting insulation systems are the object of an international discourse regarding their insulating performances. This study summarizes recent experimental and theoretical research on reflecting insulating systems carried out on an international level. Furthermore, as well as reviewing the existing literature, this contribution aims to introduce an experimental and theoretical framework sketched from the last international norms of standardization, while at the same time the major findings of an original research on reflected insulating systems in the framework of a PhD thesis are presented. To this end, a new data-driven transient heat transfer model was created to estimate the insulation capacity of typical reflecting insulating systems. The main guidelines to create an appropriate numerical model that can be easily modified in order to be valid for all the possible geometries of reflecting insulating systems are briefly presented, while the simulation results regarding a typical reflective insulating system are presented and discussed. © 2012 Taylor & Francis
Numerical estimation of air gaps' influence on the insulating performance of multilayer thermal insulation
This study aims to provide insights regarding the benefits of multilayer thermal insulations in building applications placed in combination with two air gaps. For this purpose, a numerical approach was developed to determine the influence of the air gap thickness on the overall thermal resistance of a composite wall. A validated combined radiation/conduction heat transfer numerical model was employed to predict the temperature distribution and heat transfer in typical multilayer insulation complexes comprised of insulating materials separated by multiple reflecting foils. The radiation scheme was based on the two-flux approximation, in order to model both optically thick and optically thin fibrous materials. The heat transfer equation was solved explicitly for a composite wall. A basic methodology for designing simulation scenarios was employed in order to reduce the number of simulated cases. Furthermore, strict entry requirements were provided in order to reduce extraneous variation due to the complexity of physical phenomena that should be investigated in such a case study. Finally, total nine different configurations were selected as initial state, where the theoretical thermal resistances were calculated and compared, leading towards an empirical polynomial equation that calculates the overall thermal resistance of such a composite wall complex departing from the two air gap thickness values. © 2011 Elsevier Ltd