Steel slag carbonation in a flow-through reactor system: The role of fluid-flux

2015 ◽  
Vol 27 ◽  
pp. 266-275 ◽  
Author(s):  
Eleanor J. Berryman ◽  
Anthony E. Williams-Jones ◽  
Artashes A. Migdisov
Keyword(s):  
Steel Slag ◽  
Reactor System ◽  
Fluid Flux ◽  
Flow Through

Role of Histamine and Leucotaxin in Function of Cellular Defense Mechanism

1956 ◽  
Vol 184 (2) ◽  
pp. 296-300 ◽  
Author(s):  
László Kátó ◽  
Béla Gözsy
Keyword(s):  
Fluid Flow ◽  
Tissue Damage ◽  
Inflammatory Process ◽  
Defense Mechanism ◽  
Volatile Oils ◽  
Time Intervals ◽  
Cellular Defense ◽  
Intradermal Administration ◽  
Flow Through

Experiments are presented to the effect that in an inflammatory process histamine and leucotaxin appear successively at different and orderly time intervals, thus assuring an increased fluid flow through the capillary wall. Histamine is released not only in the inflammatory process but also by intradermal administration of such substances (volatile oils or their components) which induce neither the triple response of Th. Lewis nor any tissue damage. This could be explained by the fact that in the tissues histamine is ‘present’ but leucotaxin is ‘formed.’

scholarly journals The role of inertia on fluid flow through disordered porous media

1999 ◽  
Vol 266 (1-4) ◽  
pp. 420-424 ◽  
Author(s):  
U.M.S. Costa ◽  
J.S.Andrade Jr. ◽  
H.A. Makse ◽  
H.E. Stanley
Keyword(s):  
Porous Media ◽  
Fluid Flow ◽  
Flow Through ◽  
Disordered Porous Media

Two-Dimensional Flow With Standing Vortexes in Ducts and Diffusers

1960 ◽  
Vol 82 (4) ◽  
pp. 921-927 ◽  
Author(s):  
Friedrich O. Ringleb
Keyword(s):  
Wind Tunnel ◽  
Potential Flow ◽  
Separation Control ◽  
Two Dimensional ◽  
Dimensional Flow ◽  
Princeton University ◽  
Two Dimensional Flow ◽  
Flow Through ◽  
Trapping Devices

The conditions for the equilibrium of two vortexes in a two-dimensional flow through a duct or diffuser are derived. Potential-flow considerations and a few basic results from viscous-flow theory are used for the discussion of the role of cusps as separation control and trapping devices for standing vortexes. The investigations are applied to cusp diffusers especially with regard to the wind tunnel of the James Forrestal Research Center of Princeton University.

Pressure-flow relations in coronary circulation

1990 ◽  
Vol 70 (2) ◽  
pp. 331-390 ◽  
Author(s):  
J. I. Hoffman ◽  
J. A. Spaan
Keyword(s):  
Coronary Vessels ◽  
Good Evidence ◽  
The Body ◽  
Vascular Compression ◽  
Exact Nature ◽  
Coronary Veins ◽  
Collapsible Tubes ◽  
External Pressures ◽  
Flow Through

The blood vessels that run on the surface of the heart and through its muscle are compliant tubes that can be affected by the pressures external to them in at least two ways. If the pressure outside these vessels is higher than the pressure at their downstream ends, the vessels may collapse and become Starling resistors or vascular waterfalls. If this happens, the flow through these vessels depends on their resistance and the pressure drop from their inflow to the pressure around them and is independent of the actual downstream pressure. In the first part of this review, the physics of collapsible tubes is described, and the possible occurrences of vascular waterfalls in the body is evaluated. There is good evidence that waterfall behavior is seen in collateral coronary arteries and in extramural coronary veins, but the evidence that intramural coronary vessels act like vascular waterfalls is inconclusive. There is no doubt that in systole there are high tissue pressures around the intramyocardial vessels, particularly in the subendocardial muscle of the left ventricle. The exact nature and values of the forces that act at the surface of the small intramural vessels, however, are still not known. We are not certain whether radial (compressive) or circumferential and longitudinal (tensile) stresses are the major causes of vascular compression; the role of collagen struts in modifying the reaction of vessel walls to external pressures is unknown but possibly important; direct examination of small subepicardial vessels has failed to show vascular collapse. One of the arguments in favor of intramyocardial vascular waterfalls has been that during a long diastole the flow in the left coronary artery decreases and reaches zero when coronary arterial pressure is still high: it can be as much as 50 mmHg in the autoregulating left coronary arterial bed and approximately 15-20 mmHg even when the vessels have been maximally dilated. These high zero flow pressures, especially during maximal vasodilatation, have been regarded as indicating a high back pressure to flow that is due to waterfall behavior of vessels that are exposed to tissue pressures.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Feed Utilisation Efficiency of Lupin Inclusion in Cobia: Role of Dietary Organic Selenium Supplementation

2016 ◽  
Vol 10 (10) ◽  
pp. 180 ◽  
Author(s):  
Hung Duc Pham ◽  
Ravi Fotedar ◽  
Chau Minh Nguyen ◽  
Muhammad Abu Bakar Siddik
Keyword(s):  
Crude Protein ◽  
Nutrient Digestibility ◽  
Organic Selenium ◽  
Gross Energy ◽  
Feed Utilisation ◽  
Kernel Meal ◽  
Flow Through ◽  
Inclusion Level ◽  
Utilisation Efficiency

The dietary selenium (Se) requirement has been determined for cobia Rachycentron canadum using purified diet; however, its role in the utilisation of plant-derived ingredients has not been evaluated in the species. Therefore, a 3 x 2 factorial experimental design involving three inclusion levels (0, 210 and 315 g/kg) of lupin Lupinus angustifolius kernel meal (LKM) and two concentrations (0 and 0.8 mg/kg) of Se was used to evaluate the effects of Se supplementation in conjunction with LKM on the growth, feed utilisation and physiological responses in the cobia. Six isonitrogenous (46.5 % crude protein) and isoenergetic (21 MJ/kg gross energy) diets were formulated and fed to cobia for 7 weeks in a flow-through seawater system. The results showed significant effects of Se supplementation and its interaction with dietary lupin on the growth and feed efficiency of cobia. Se supplementation significantly improved the growth and feed utilisation efficiency in cobia fed lupin-based diets. The nutrient digestibility of fish fed supplemental Se lupin-based diets was significantly higher than that of fish fed diets without Se supplementation at each inclusion level of LKM. There were no significant effects of dietary Se supplementation on the survival, muscle composition or muscle amino acids, whereas regression analysis indicated a positive linear relationship between tissue Se accumulation and dietary Se levels. An enhancement of haematological responses was also observed in cobia fed Se-supplemented diets. In summary, cobia fed lupin-based diets required higher dietary Se supplementation for higher feed utilisation efficiency than previously quantified for the casein-based diet.

scholarly journals Effect of time and vascular pressure on permeability and cyclic nucleotides in ischemic lungs

2000 ◽  
Vol 279 (5) ◽  
pp. H2077-H2084 ◽  
Author(s):  
David B. Pearse ◽  
Patrice M. Becker
Keyword(s):  
Nitric Oxide ◽  
High Pressure ◽  
Reflection Coefficient ◽  
Cyclic Nucleotides ◽  
Fluid Flux ◽  
No Donor ◽  
Independent Mechanism ◽  
Dependent Mechanism ◽  
Intravascular Pressure

We previously found that increased intravascular pressure decreased ischemic lung injury by a nitric oxide (NO)-dependent mechanism (Becker PM, Buchanan W, and Sylvester JT. J Appl Physiol 84: 803–808, 1998). To determine the role of cyclic nucleotides in this response, we measured the reflection coefficient for albumin (ςalb), fluid flux ( J˙), cGMP, and cAMP in ferret lungs subjected to either 45 min (“short”; n = 7) or 180 min (“long”) of ventilated ischemia. Long ischemic lungs had “low” (1–2 mmHg, n = 8) or “high” (7–8 mmHg, n = 6) vascular pressure. Other long low lungs were treated with the NO donor ( Z)-1-[ N-(3-ammoniopropyl)- N-( n-propyl)amino]diazen-1-ium-1,2-diolate (PAPA-NONOate; 5 × 10−4 M, n = 6) or 8-bromo-cGMP (5 × 10−4 M, n = 6). Compared with short ischemia, long low ischemia decreased ςalb (0.23 ± 0.04 vs. 0.73 ± 0.08; P < 0.05) and increased J˙ (1.93 ± 0.26 vs. 0.58 ± 0.22 ml · min−1 · 100 g−1; P < 0.05). High pressure prevented these changes. Lung cGMP decreased by 66% in long compared with short ischemia. Lung cAMP did not change. PAPA-NONOate and 8-bromo-cGMP increased lung cGMP, but only 8-bromo-cGMP decreased permeability. These results suggest that ischemic vascular injury was, in part, mediated by a decrease in cGMP. Increased vascular pressure prevented injury by a cGMP-independent mechanism that could not be mimicked by administration of exogenous NO.

pH environmental of red cells in the spleen

1976 ◽  
Vol 231 (6) ◽  
pp. 1672-1678 ◽  
Author(s):  
MJ Levesque ◽  
AC Groom
Keyword(s):  
Splenic Tissue ◽  
Red Cells ◽  
Red Cell ◽  
Cat Spleen ◽  
Flow Through ◽  
Red Pulp ◽  
Reduced Flow

Intrasplenic pH in vivo was deduced from measurements on blood drained from cat spleen during contraction with the inflow occluded. The pH of blood in the red pulp is normally 7.20, but stasis or reduced flow through the pulp causes pH to fall toward 6.8. The splenic pulp contains blood of high hematocrit. To evaluate the role of buffering by the red cells themselves, intrasplenic p/ in red cell-free spleens was, therefore, estimated atering and leaving the spleen during red cell washout. At inflow pH less than 6.8 the outflow pH was raised, at inflow pH = 6.8 there was no change, b,t at inflow pH greater than 6.8 the outflow pH was lowered. These results indicate that the pH environment of red cells in the spleen results indicate that the pH environment of red cells in the spleen results from the interplay of two separate factors: i) pH-determining elements of the splenic tissue that buffer at 6.8, and ii) buffering provided by red cells passing through the pulp.

scholarly journals Glycogenolysis in Astrocytes Supports Blood-Borne Glucose Channeling Not Glycogen-Derived Lactate Shuttling to Neurons: Evidence from Mathematical Modeling

2010 ◽  
Vol 30 (12) ◽  
pp. 1895-1904 ◽  
Author(s):  
Mauro DiNuzzo ◽  
Silvia Mangia ◽  
Bruno Maraviglia ◽  
Federico Giove
Keyword(s):  
Glycogen Synthesis ◽  
Product Inhibition ◽  
Current Thinking ◽  
Metabolic Requirement ◽  
Previous Modeling Study ◽  
Extracellular Glucose ◽  
Subcellular Domains ◽  
Glucose Phosphorylation ◽  
Flow Through

In this article, we examined theoretically the role of human cerebral glycogen in buffering the metabolic requirement of a 360-second brain stimulation, expanding our previous modeling study of neurometabolic coupling. We found that glycogen synthesis and degradation affects the relative amount of glucose taken up by neurons versus astrocytes. Under conditions of 175:115 mmol/L (∼1.5:1) neuronal versus astrocytic activation-induced Na+ influx ratio, ∼12% of astrocytic glycogen is mobilized. This results in the rapid increase of intracellular glucose-6-phosphate level on stimulation and nearly 40% mean decrease of glucose flow through hexokinase (HK) in astrocytes via product inhibition. The suppression of astrocytic glucose phosphorylation, in turn, favors the channeling of glucose from interstitium to nearby activated neurons, without a critical effect on the concurrent intercellular lactate trafficking. Under conditions of increased neuronal versus astrocytic activation-induced Na+ influx ratio to 190:65 mmol/L (∼3:1), glycogen is not significantly degraded and blood glucose is primarily taken up by neurons. These results support a role for astrocytic glycogen in preserving extracellular glucose for neuronal utilization, rather than providing lactate to neurons as is commonly accepted by the current ‘thinking paradigm’. This might be critical in subcellular domains during functional conditions associated with fast energetic demands.

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