scholarly journals Fluid transport in geological reservoirs with background flow

2017 ◽  
Vol 827 ◽  
pp. 536-571 ◽  
Author(s):  
Samuel S. Pegler ◽  
Alexandra S. D. Maskell ◽  
Katherine A. Daniels ◽  
Mike J. Bickle
Keyword(s):  
Fluid Transport ◽  
Similarity Solutions ◽  
Long Term Effects ◽  
Background Flow ◽  
Triangular Profile ◽  
Short Time ◽  
Background Motion ◽  
Shock Layers ◽  
Instantaneous Control

This paper presents fundamental analysis of the injection and release of fluid into porous media or geological reservoirs saturated by a different fluid undergoing a background flow, and tests the predictions using analogue laboratory experiments. The study reveals new results important for an understanding of the transport of hazardous contaminants through aquifers and the long-term fate of carbon dioxide ($\text{CO}_{2}$) in geological $\text{CO}_{2}$ sequestration. Using numerical and asymptotic analysis, we describe a variety of flow regimes that arise, and demonstrate an almost instantaneous control of injected fluid by the far field conditions in geological reservoirs. For a continuous input, the flow develops a horizontal interface between the injected and ambient fluids. The background flow thereby effectively caps the height of the injected fluid into a shallower region of vertical confinement. For a released parcel of fluid, gravitational spreading is found to become negligible after a short time. A dominant control of the interface by the background pressure gradient arises, and stems from the different velocities at which it drives the injected and ambient fluids individually. Similarity solutions describing these dynamics show that the parcel approaches a slender triangular profile that grows horizontally as $t^{1/2}$, where $t$ is time, a rate faster than relaxation under gravity. Shock layers develop at the front or back of the parcel, depending on whether it is more or less viscous than the ambient fluid. New analytical results describing the long-term effects of residual trapping due to capillary retention are developed, which yield explicit predictions for the time and length scales on which a parcel of $\text{CO}_{2}$ becomes retained. We end by applying our results to geological contexts, concluding that even slight background motion can have considerable implications for long-term transport through the subsurface.

Catheter Patency and Peritoneal Morphology and Function in a Rat Model of Citrate-Buffered Peritoneal Dialysis

2010 ◽  
Vol 30 (6) ◽  
pp. 602-610 ◽  
Author(s):  
Nicola Cavallini ◽  
Magnus Braide
Keyword(s):  
Peritoneal Dialysis ◽  
Rat Model ◽  
Fluid Transport ◽  
Separate Experiment ◽  
Control Group ◽  
Vascular Density ◽  
Long Term Effects ◽  
Catheter Patency ◽  
Peritoneal Morphology

BackgroundSingle-dwell studies in rats and humans have shown that supplementing citrate for lactate in peritoneal dialysis (PD) fluids improves ultrafiltration (UF).MethodsThe long-term effects of citrate-substituted PD fluids on PD catheter patency, UF, and peritoneal morphology were evaluated in a rat model over 5 weeks of daily PD fluid exposure. A standard 2.5% glucose 40 mmol/L lactate PD fluid and a corresponding 10/30 mmol/L citrate/lactate PD fluid were compared. In a control group, rats with catheters received no PD fluid.ResultsThe average patency time (% of 36 days) of silicone rubber PD catheters was significantly longer in the citrate PD group (98.8% ± 1.2%) and the control group (100% ± 0%) compared to the lactate PD group (54.7% ± 9.5%). In a separate experiment, heparin-coated polyurethane catheters were used to study peritoneal morphology and fluid transport. The citrate group had a higher net UF than the lactate group at the beginning and at the end of the 5 weeks. During the experiment, both fluid-treated groups suffered from UF loss; the control group showed the highest net UF at the end of the 5 weeks. Peritoneal vascular density and submesothelial thickness, indicators of angiogenesis and fibrosis, were not significantly different among the groups. Fibrosis was significantly negatively correlated to osmotic UF.ConclusionA positive acute effect of citrate on UF was confirmed and conserved over time. Citrate PD strongly improved PD catheter patency time compared with lactate. Both citrate PD and lactate PD induced negative long-term effects on UF compared with control animals.

Selected Contribution: Long-term effects of β2-adrenergic receptor stimulation on alveolar fluid clearance in mice

2002 ◽  
Vol 93 (5) ◽  
pp. 1875-1880 ◽  
Author(s):  
C. Sartori ◽  
X. Fang ◽  
D. W. McGraw ◽  
P. Koch ◽  
M. E. Snider ◽  
...  
Keyword(s):  
Adrenergic Receptor ◽  
Fluid Transport ◽  
Alveolar Fluid Clearance ◽  
Camp Production ◽  
Long Term Effects ◽  
Agonist Stimulation ◽  
Β2 Adrenergic Receptor ◽  
Stimulation Of ◽  
Alveolar Edema

Stimulation of active fluid transport with β-adrenergic receptor (βAR) agonists can accelerate the resolution of alveolar edema. However, chronic βAR-agonist administration may cause βAR desensitization and downregulation that may impair physiological responsiveness to βAR-agonist stimulation. Therefore, we measured baseline and terbutaline- (10−3 M) stimulated alveolar fluid clearance in mice that received subcutaneously (miniosmotic pumps) either saline or albuterol (2 mg · kg−1 · day−1) for 1, 3, or 6 days. Continuous albuterol administration increased plasma albuterol levels (10−5 M), an effect that was associated with 1) a significant decrease in βAR density and 2) attenuation, but not ablation, of maximal terbutaline-induced cAMP production. Forskolin-mediated cAMP-release was unaffected. Continuous albuterol infusion stimulated alveolar fluid clearance on day 1 but did not increase alveolar fluid clearance on days 3 and 6. However, terbutaline-stimulated alveolar fluid clearance in albuterol-treated mice was not reduced compared with saline-treated mice. Despite significant reductions in βAR density and agonist-mediated cAMP production by long-term βAR-agonist exposure, maximal βAR-agonist-mediated increase in alveolar fluid clearance is not diminished in mice.

Mikroökonometrische Evaluation der ökonomischen Wirkungen betrieblicher Mitbestimmung - Möglichkeiten und Grenzen des Matching-Ansatzes / Microeconometric Evaluation of Economic Effects of Workers Participation - Options und Limits of the Matching Approach

2006 ◽  
Vol 226 (5) ◽  
Author(s):  
Birgit Schultz
Keyword(s):  
Point Of View ◽  
Economic Effects ◽  
Small Samples ◽  
Long Term Effects ◽  
Works Councils ◽  
East German ◽  
Iab Establishment Panel ◽  
Microeconometric Evaluation ◽  
Short Time

SummaryThe evaluation of economic effects of workers participation is not simple from the methodical point of view because of specific characteristics of establishments with works councils. Especially recent studies show contradictory results. In this study problems are pointed out, discussed, and options for solution are presented on the example of workers participation in East German establishments of industry and construction by the IAB-Establishment Panel.An optimal matching-algorithm which supplies good matching-results for small samples to assign ‘statistical establishment-twins’ is applied. But by reason of very short primarily spells it can only calculate short time effects. Therefore, the matching method is additionally used to construct longer observation periods. By this new application establishments with recently founded works councils are matched with so called ‘proxy establishments’ with existing works councils. As a result short observation periods are prolonged and information about long-term effects can be given.The effects on productivity, profitability and qualification level of employees show neither in short-term nor in long-term a significant impact on workers’ participation.

scholarly journals Social Nesting, Animal Welfare and Disease Monitoring

2021 ◽  
Author(s):  
Lydia Giménez-Llort ◽  
Virginia Torres-Lista
Keyword(s):  
Low Cost ◽  
Social Deficits ◽  
Long Term Effects ◽  
Maximum Score ◽  
Non Invasive ◽  
Naturally Occurring ◽  
Potential Risk Factors ◽  
Sensorial Stimulation ◽  
Short Time

The assessment of welfare and disease progression in animal models is critical. Most tools rely on evaluating individual subjects, whereas social behaviors, also sensitive to acute illness, chronic diseases, or mental health, are scarcely monitored because of their complexity, are invasive, and time-consuming. We propose the evaluation of social nesting, a species-typical behavior naturally occurring in standard housing conditions, for such behavioral monitoring. We provide an example of its use to evaluate social deficits and the long-term effects of neonatal sensorial stimulation in male and female adult 3xTg-AD mice for Alzheimer's disease compared to sex- and age-matched NTg counterparts with normal aging. Social nesting was sensitive to genotype (worse in 3xTg-AD mice), sex (worse in males), profile, and treatment (distinct temporal patterns, time to observe the maximum score and incidence of the perfect nest). Since social nesting can be easily included in housing routines, this neuroethological approach can be useful for animal's welfare, monitoring the disease's progress, and evaluating potential risk factors and effects of preventive/therapeutical strategies. Finally, the non-invasive, painless, simple, short time and low-cost features of this home-cage monitoring are advantages that make social nesting feasible to be successfully implemented in most animal department settings.

scholarly journals Long Term Effects of Low-Level Sarin Inhalation Exposure on the Spatial Memory of Rats in a T-Maze

2001 ◽  
Vol 44 (3) ◽  
pp. 93-96 ◽  
Author(s):  
Jiří Kassa ◽  
Marie Koupilová ◽  
Josef Vachek
Keyword(s):  
Spatial Memory ◽  
Cognitive Functions ◽  
Inhalation Exposure ◽  
Long Term Effects ◽  
Low Level ◽  
Appetitive Motivation ◽  
Low Concentrations ◽  
Level 3 ◽  
Short Time

To study the influence of low-level sarin exposure on cognitive functions, male albino Wistar rats were exposed to three various low concentrations of sarin (LEVEL 1–3) for 60 minutes in the inhalation chamber. Testing of cognitive functions was carried out using the T-maze evaluating learning and spatial memory. The behavior of sarin-exposed rats in the T-maze was tested several times within five weeks following sarin inhalation exposure to look for any cognitive impairments. The alteration of cognition was evaluated by using a method studying memory elicitation in response to appetitive motivation in a multiple T-maze. 2. Statistically significant, short-term deficiency in the T-maze performance was observed in rats exposed to symptomatic (LEVEL 3) as well as clinically asymptomatic concentration (LEVEL 2) of sarin. The repeated exposure of rats to clinically asymptomatic dose of sarin (LEVEL 2R) did not change the effect of lowlevel sarin exposure on spatial memory compared to the single exposure to the same dose of sarin. 3. Thus, sarin is able to influence the cognitive functions (e.g. spatial memory) even at low doses that do not cause clinically manifested intoxication following the inhalation exposure. Nevetheless, the alteration of spatial memory lasts for a short time only, in contrast with the severe sarin poisoning.

scholarly journals The Future of Higher Education: The Effects of Covid-19 on Teaching, Research and Internationalization

2021 ◽  
Vol 10 (3) ◽  
pp. 249-259
Author(s):  
Alper Çalıkoğlu ◽  
Sedat Gümüş
Keyword(s):  
Higher Education ◽  
Long Term Effects ◽  
Higher Education System ◽  
Turkish Higher Education ◽  
Teaching Research ◽  
Short And Long Term ◽  
Different Dimensions ◽  
Internationalization In Higher Education ◽  
Short Time

Covid-19, which emerged in Wuhan, China at the end of 2019 and has turned into a pandemic in a short time, has brought many social problems. It is clear that it will also have some short and long term effects in the field of higher education. Based on the recent publications, the current study aims to discuss what these effects will be in different dimensions of higher education. However, due to the difficulties of covering so many different pandemic-related developments within a single study, the current study focuses more on the effects of the Covid-19 process on teaching, research and internationalization in higher education. Based on the recent discussions on these focal themes, recommendations are made specifically for the Turkish higher education system.

scholarly journals Social Nesting, Animal Welfare, and Disease Monitoring

Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1079
Author(s):  
Lydia Giménez-Llort ◽  
Virginia Torres-Lista
Keyword(s):  
Animal Welfare ◽  
Low Cost ◽  
Social Deficits ◽  
Long Term Effects ◽  
Maximum Score ◽  
Naturally Occurring ◽  
Potential Risk Factors ◽  
Sensorial Stimulation ◽  
Short Time

The assessment of welfare and disease progression in animal models is critical. Most tools rely on evaluating individual subjects, whereas social behaviors, also sensitive to acute illness, chronic diseases, or mental health, are scarcely monitored because they are complex and time-consuming. We propose the evaluation of social nesting, a species-typical behavior naturally occurring in standard housing conditions, for such behavioral monitoring. We provide an example of its use to evaluate social deficits and the long-term effects of neonatal tactile-proprioceptive sensorial stimulation from postnatal day 1 to 21, in male and female adult 3xTg-AD mice for Alzheimer’s disease compared to sex- and age-matched non-transgenic (NTg) counterparts with normal aging. Social nesting was sensitive to genotype (worse in 3xTg-AD mice), sex (worse in males), profile, and treatment (distinct time to observe the maximum score and incidence of the perfect nest). Since social nesting can be easily included in housing routines, this neuroethological approach can be useful for animal welfare, monitoring the disease’s progress, and evaluating potential risk factors and effects of preventive/therapeutical strategies. Finally, the noninvasive, painless, simple, short time, and low-cost features of this home-cage monitoring are advantages that make social nesting feasible to be successfully implemented in most animal department settings.

Ovarian Dysfunction in Fetally Irradiated Beagles

1977 ◽  
Vol 35 ◽  
pp. 658-659
Author(s):  
T. M. Seed ◽  
M. H. Sanderson ◽  
D. L. Gutzeit ◽  
T. E. Fritz ◽  
D. V. Tolle ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Low Dose ◽  
Long Term Effects ◽  
Ovarian Dysfunction ◽  
Dose Rates ◽  
Highly Sensitive ◽  
Microscopic Evaluation ◽  
Ovarian Pathology ◽  
Normal Offspring

The developing mammalian fetus is thought to be highly sensitive to ionizing radiation. However, dose, dose-rate relationships are not well established, especially the long term effects of protracted, low-dose exposure. A previous report (1) has indicated that bred beagle bitches exposed to daily doses of 5 to 35 R 60Co gamma rays throughout gestation can produce viable, seemingly normal offspring. Puppies irradiated in utero are distinguishable from controls only by their smaller size, dental abnormalities, and, in adulthood, by their inability to bear young.We report here our preliminary microscopic evaluation of ovarian pathology in young pups continuously irradiated throughout gestation at daily (22 h/day) dose rates of either 0.4, 1.0, 2.5, or 5.0 R/day of gamma rays from an attenuated 60Co source. Pups from non-irradiated bitches served as controls. Experimental animals were evaluated clinically and hematologically (control + 5.0 R/day pups) at regular intervals.

Ultrastructural investigations of MDL 19,660-induced effects on the canine platelet and megakaryocyte

1990 ◽  
Vol 48 (3) ◽  
pp. 374-375
Author(s):  
D.E. Loudy ◽  
J. Sprinkle-Cavallo ◽  
J.T. Yarrington ◽  
F.Y. Thompson ◽  
J.P. Gibson
Keyword(s):  
Antidepressant Drug ◽  
Beagle Dogs ◽  
Long Term Effects ◽  
Short Term ◽  
Platelet Counts ◽  
Toxicological Studies ◽  
Induced Aggregation ◽  
Internal Architecture

Previous short term toxicological studies of one to two weeks duration have demonstrated that MDL 19,660 (5-(4-chlorophenyl)-2,4-dihydro-2,4-dimethyl-3Hl, 2,4-triazole-3-thione), an antidepressant drug, causes a dose-related thrombocytopenia in dogs. Platelet counts started to decline after two days of dosing with 30 mg/kg/day and continued to decrease to their lowest levels by 5-7 days. The loss in platelets was primarily of the small discoid subpopulation. In vitro studies have also indicated that MDL 19,660: does not spontaneously aggregate canine platelets and has moderate antiaggregating properties by inhibiting ADP-induced aggregation. The objectives of the present investigation of MDL 19,660 were to evaluate ultrastructurally long term effects on platelet internal architecture and changes in subpopulations of platelets and megakaryocytes.Nine male and nine female beagle dogs were divided equally into three groups and were administered orally 0, 15, or 30 mg/kg/day of MDL 19,660 for three months. Compared to a control platelet range of 353,000- 452,000/μl, a doserelated thrombocytopenia reached a maximum severity of an average of 135,000/μl for the 15 mg/kg/day dogs after two weeks and 81,000/μl for the 30 mg/kg/day dogs after one week.

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