585 research outputs found
Performance Analysis of Advanced Wells in Reservoirs Using CO2 Enhanced Oil Recovery; Simulations and Cost Estimation
No full textThis thesis encompasses the study of advanced wells applications in reservoirs using immiscible CO2 for enhanced oil recovery. The goal of this thesis is to analyze the performance of advanced wells in different simulated reservoir conditions and figure out the suitable option with high performance ability and cost effectiveness for real life implementation.
The research begins with a detailed literature review of the methods, mechanisms, and fundamental parameters related to immiscible CO2 enhanced oil recovery. The literature review further explains the types and working principles of different advanced wells.
The succeeding chapter contains the reservoir model, well model and simulation cases. The details of the parameters and completion scenarios has been documented in the chapter. With varying parameters, the difference in the oil recovery performance and impact on it by different advanced wells was assessed.
The outcome of the computer aided simulations demonstrates that the oil recovery is heavily depend on the permeability and injection rate of CO2 in the reservoir. Furthermore, AICVs have been seen to have better performance in terms of oil extraction and cost effectiveness
Silene astartes C.I. Blanche ex Boiss., Fl. Orient. Suppl.
No full textSilene astartes C.I. Blanche ex Boiss., Fl. Orient. Suppl.: 102. 1888. Lectotypus (designated here): Lebanon . Prov. Mount-Lebanon: Djebaïl, ruines d’AFka, VI-VII.1880, fl. & Fr., Blanche 55 (G-BOIS [G00330604]!; isolecto-: BEI!, G [G00341654]!) (Fig. 1). Notes. – Boissier (1888) published S. astartes in the “Supplementum oF the Flora Orientalis”. He wrote “ S. astartes (Blanche in litt.)” beFore the Latin description. Ŋe mention oF Blanche as the author “in litt.” by Boissier has been interpreted in different ways in the literature. Floras oF Lebanon have cited only C.I. Blanche as the author oF the species (sometimes with the mention “in Boiss.”; Post, 1896, 1932; ThiÉbaut, 1936; Mouterde, 1966; TohmÉ & TohmÉ, 2007), whereas BouloumoY (1930) interpreted the authorship as “Boiss. et B.” [Boiss. & C.I. Blanche]. In the Boissier’s Herbarium oF the “Flora Orientalis” (G-BOIS), Blanche 55 contains a handwritten note by Blanche himselF with a Latin description oF the species (Fig. 1). However this description differs considerably From the protologue where Boissier published a new and more complete description by validating the name (Boissier, 1888: 102). We thereFore ascribe Boissier as the author oF S. astartes in accordance with Greuter et al. (1984) and not as C.I. Blanche as mentioned in the latest flora oF Lebanon treatment (TohmÉ & TohmÉ, 2007). Boissier (1888) clearly cited two gatherings in the protologue: “Hab. in Libano supra Djebail ad minas AFka (Bl.!)” and “ad Ain SuFar (Peyron!)”. Only Blanche 55 [G00330604] is present in G-BOIS. We Found three duplicates oF the Peyron collection at G and one at P. Each oF them bears the locality “Ain SuFar” and are dated June 11, 1882. Two oF them have the collection number 1379 mentioned [G00341656, P04987226]) and two [G00341655, G00341657] without any number. All these collections have a glandular-pubescent calyx and match Fully with S. italica (L.) Pers. and not with S. astartes, which has a calyx always glabrous. ŊereFore, we choose Blanche 55 housed at G-BOIS as the lectotype, which is the only material present at G-BOIS and exclude the remaining syntypes From S. astartes.Published as part of Pierre-Emmanuel Du Pasquier & Daniel Jeanmonod, 2016, Lectotypification of three species of Silene sect. Italicae (Rohrb.) Schischk. (Caryophyllaceae), pp. 19-22 in Candollea 71 (1) on page 21, DOI: 10.15553/c2016v711a4, http://zenodo.org/record/16204
Supplementation to Improve Anticoagulation Control with Low Dose Vitamin K as an Adjuvant to Warfarin Therapy: A Double-blind, Placebo-controlled Randomized Controlled Trial
No full textVitamin K Antagonists [VKA] are the most frequently used oral anticoagulants in clinical practice; however, many patients fail to achieve adequate anticoagulation control. We conducted a randomized, placebo controlled, double blind study of Vitamin K1 (200mcg per day, Swanson Vitamins) in a population with predominantly venous thromboembolism aimed at evaluating its effectiveness in improving anticoagulation control in unstable patients. This study also aimed to evaluate the impact that clinical variables, patient anticoagulation knowledge, and genetic polymorphisms in genes known to impact warfarin and Vitamin K metabolism [VKORC1, CYP4F2, CYP2C9] had on anticoagulation control and intervention effectiveness. A total of N=54 patients were enrolled in the study over 15 months [January 2009 to June 2010]. Change score analysis and multivariate linear regression modelling of anticoagulation control measures were performed. No statistically significant reduction was observed in the Vitamin K1 arm for percent time in therapeutic range; however, reduction was observed in standard deviation of INRs [Change Score Vitamin K = -0.259, p=0.0261; Regression Model 95% C.I Beta Vitamin K = 0.38 to -0.08] during the intervention period. Adjusting for treatment group allocation, independent predictors of increased INR standard deviation included: >5 alcoholic drinks per week [95% C.I Beta = 0.04 to 0.41], self-reported dosing errors [95% C.I Beta = 0.13 to 0.47], and missed INR appointments [95% C.I Beta = 0.002 to 0.05
Supplementation to Improve Anticoagulation Control with Low Dose Vitamin K as an Adjuvant to Warfarin Therapy: A Double-blind, Placebo-controlled Randomized Controlled Trial
No full textVitamin K Antagonists [VKA] are the most frequently used oral anticoagulants in clinical practice; however, many patients fail to achieve adequate anticoagulation control. We conducted a randomized, placebo controlled, double blind study of Vitamin K1 (200mcg per day, Swanson Vitamins) in a population with predominantly venous thromboembolism aimed at evaluating its effectiveness in improving anticoagulation control in unstable patients. This study also aimed to evaluate the impact that clinical variables, patient anticoagulation knowledge, and genetic polymorphisms in genes known to impact warfarin and Vitamin K metabolism [VKORC1, CYP4F2, CYP2C9] had on anticoagulation control and intervention effectiveness. A total of N=54 patients were enrolled in the study over 15 months [January 2009 to June 2010]. Change score analysis and multivariate linear regression modelling of anticoagulation control measures were performed. No statistically significant reduction was observed in the Vitamin K1 arm for percent time in therapeutic range; however, reduction was observed in standard deviation of INRs [Change Score Vitamin K = -0.259, p=0.0261; Regression Model 95% C.I Beta Vitamin K = 0.38 to -0.08] during the intervention period. Adjusting for treatment group allocation, independent predictors of increased INR standard deviation included: >5 alcoholic drinks per week [95% C.I Beta = 0.04 to 0.41], self-reported dosing errors [95% C.I Beta = 0.13 to 0.47], and missed INR appointments [95% C.I Beta = 0.002 to 0.05
Temperature dependence of exciton-capture at impurities in GaAs/AlxGa(1-x) As quantum wells
No full textIn this paper we present an investigation of the exciton capture process in GaAs/Al.3Ga.7As quantum wells using a picosecond time-resolved photoluminescence technique. We demonstrate that there are significant differences in the capture mechanism for narrow quantum wells in comparison to bulk material. In particular the initial capture efficiency is shown to increase with temperature. This behaviour is understood in terms of the role of localisation of the free exciton in the potentials caused by the interface roughness. Higher temperatures destroy this localisation process which otherwise limits the total capture rate for the exciton to the impurity. The effect of localisation on capture is also shown to be stronger for narrower wells. We conclude that the relative weakness of bound exciton recombination in the near bandgap luminescence of doped quantum wells can in part be understood by the reduction of capture efficiency due to localisation
Establishing the test–retest reliability & concurrent validity for the repeat ice skating test (RIST) in adolescent male ice hockey players
No full textIn this study the authors examine the test–retest reliability and concurrent validity of the Repeat Ice Skating Test (RIST). This was an on-ice field anaerobic test that measured average peak power and was validated with 3 anaerobic lab tests: (a) vertical jump, (b) the Margaria–Kalamen stair test, and (c) the Wingate Anaerobic Test. The participants (n = 14) were 11- to 12-year-old males selected from a Peewee “A” level ice hockey team (Thunder Bay, Canada). The results of the test–retest reliability estimation showed that the RIST was a reliable test at measuring average peak power in watts (R = .99, C.I.95% = 0.97 to 0.99) and watts per kilogram (R = .98, C.I.95% = 0.94 to 0.99). The RIST was also a valid test when correlated with the 3 anaerobic lab tests for measuring peak power in watts: vertical jump (r = .86, C.I.95% = 0.72 to 0.94), Margaria–Kalamen stair test (r = .66, C.I.95% = 0.39 to 0.83) and Wingate Anaerobic Test (r = .86, C.I.95% = 0.72 to 0.93). The test is considered promising because it does not require any specific equipment, and is a sport-specific, on-ice test, that can be administered during a regular ice hockey practice session
C.I. Acid Black 1 transfer from dilute solution to perlite framework in organic waste management
No full textDyes, considered as toxic and persistent pollutants, must be removed from organic wastes prior to their composting and application in sustainable agriculture. Azo dyes, capable of altering the physicochemical properties of soil, are difficult to expel by conventional wastewater treatments. C.I. Acid Black 1 (AB 1), a sulfonated azo dye, inhibits nitrification and ammonification in the soil, lessens the nitrogen use efficacy in crop production and passes substantially unaltered through an activated sludge process. The retention of C.I. Acid Black 1 by raw and expanded perlite was investigated in order to examine the potential effectiveness of this aluminosilicate material toward organic waste cleanup. Dye adsorption proved spontaneous and endothermic in nature, increasing with temperature for both perlites. Expanded perlite having a more open structure exhibited a better performance compared to the raw material. Several of the most widely recognized two-parameter theoretical models, i.e., Langmuir, Freundlich, Temkin, Brunauer–Emmett–Teller (BET), Harkins–Jura, Halsey, Henderson, and Smith, were applied to reveal physicochemical features characterizing the adsorption. The Langmuir, Freundlich, Temkin, BET, Henderson, and Smith equations best fitted experimental data indicating that the adsorption of anionic dye on perlites is controlled by their surface, i.e., non-uniformity in structure and charge. This heterogeneity of surface is considered responsible for promoting specific dye adsorption areas creating dye “islands” with local dye supersaturations. © The Author(s) 2024
CO2 Enhanced Oil Recovery in Reservoirs with Advanced Wells: Simulations and Sensitivity Analysis
No full textInjection of CO2 for enhanced oil recovery (CO2-EOR) is used in fields with high amount of residual oil. CO2-EOR refers to a technology where supercritical CO2 is injected into an oil reservoir to increase the oil production. Utilizing autonomous inflow control valves (AICVs) in CO2-EOR projects contributes to a better distribution of CO2 in the reservoir, reduction in production of water and CO2 mixture, and thereby increased storage capacity of CO2. The main objective of this study is modelling and simulation of oil production from an oil reservoir using CO2 water alternating gas (CO2 WAG) injection in combination with advanced wells that are completed with AICVs. The results from the simulations indicate that well completion with AICV can maintain good oil production while the production of water is decreased from 3e+06 m3 to 9.8e+04 m3 which corresponds to 97% reduction in water production. The sensitivity analysis of the simulation results affirms that permeability, well placement, and well spacing have impact on oil recovery and water production. The results indicate that permeability increase has a slight increment effect on oil recovery. The well spacing analysis shows that increasing the distance between the wells will increase the oil recovery and delay the water breakthrough. Lastly the well placement analysis shows that vertical injection of miscible CO2 produces more oil than horizontal injection of miscible CO2. AICVs restrict the production of mixture of CO2 and water, and thereby cause a better distribution of CO2 in the reservoir
Bone Manganese as a Potential Biomarker of Cumulative Manganese Exposure and Predictor of Neurological Decline
No full textResearch into the health effects of cumulative exposure to manganese (Mn) has been limited due to the lack of a biomarker that adequately represents cumulative exposure. In this cross-sectional study, we assessed the usefulness of bone Mn (BnMn) as a biomarker of cumulative Mn exposure and as an indicator of neurological decline. Our research group utilized a novel, transportable, in vivo Neutron Activation Analysis (NAA) system to analyze BnMn in a group of Chinese workers (N=60). In addition to bone, blood and fingernail samples were also collected from participants and analyzed for Mn. Participants completed a questionnaire that included work history and demographic information as well as a battery of cognitive, motor, and olfactory tests. Using participants\u27 work history, a cumulative exposure index (CEI) was created to represent long-term, occupational Mn exposure. Years of Mn exposure (MnYears) were also determined from participants work history. The relationship between BnMn and 1) Mn exposure variable (CEI and MnYears), 2) blood Mn (BMn), and 3) fingernail Mn (FMn) were assessed to investigate which biomarkers were more strongly associated with BnMn. The relationships between blood, fingernail, and bone Mn and the battery of cognitive (Animal Naming, Fruit Naming, UCLA/WHO Audio Verbal Listening Test (AVLT)), olfactory (University of Pennsylvania Smell Identification Test (UPSIT)), and motor (Purdue Pegboard, CATSYS Motor System) tests were also assessed to investigate which biomarker was most sensitive to changes in neurological function. Median (interquartile range) BMn, FMn and BnMn were 14.1 (4.0) µg/L, 6.1 (39.8) µg/g, and 2.6 (7.2) µg/g respectively. In regression models adjusted for age and education, BnMn was significantly associated with increased FMn (β=1.38; 95% confidence interval (CI)=0.75, 2.00), Mn CEI over the past 15 years (MnCEI15) (β=5.33; 95% CI=2.07, 8.59) and Years of Mn exposure over the past 15 years (MnYears15) (β=1.73; 95% CI=0.17, 3.30), but not other measures. In regression models adjusted for age, education and current factory of employment, BnMn was significantly associated with decreasing average AVLT scores over the first 5 trials [β (95% CI) = -0.6 (-1.2, -0.09)] along with decreasing Animal Naming scores [β (95% CI) = -1.5 (-3.0, -0.7)]. FMn was also significantly associated with decreases in average AVLT scores [β (95% CI) = -0.4 (-0.7, -0.03))] as well as decreases in a difference in AVLT scores [β (95% CI) = -0.4 (-0.7, -0.02)]. BMn was not significantly associated with any test scores. Out of the three Mn biomarkers, BnMn was the greater predictor of decreasing function in 5 out of the 9 scores. Continuous ln(BnMn) was associated with several CATSYS outcomes such as decreasing Rhythmic P/S fast (Non-dominant hand) (β = -0.019; 95% C.I. = -0.036, -0.002), decreasing Rhythmic F-Tap fast (Non-dominant hand) (β = -0.027; 95% C.I. = -0.045, -0.008), increasing Center frequency (Dominant hand) (β = 0.443; 95% C.I. = 0.029, 0.858), and increasing tremor intensity (β = 0.011; 95% C.I. = 0.0001, 0.022). Overall these results suggest BnMn could be a useful biomarker of cumulative Mn exposure over the span of the past 15–16 years. They also demonstrate the association of BnMn with cognitive and motor outcomes
Different approaches to enhancing selenium levels in wheat cultivars
No full textRadiation, Science and TechnologyApplied Science
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