Physical and Chemical Characteristics of Cultus Lake, British Columbia.

1937 ◽  
Vol 3 (4) ◽  
pp. 363-402 ◽  
Author(s):  
William E. Ricker
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Content ◽  
Heat Budget ◽  
Clear Lake ◽  
Equable Climate ◽  
Low Degree ◽  
Seasonal Circulation ◽  
Measure Oxygen Consumption ◽  
Physical And Chemical

Cultus lake is a rather small, fairly deep, clear lake of the western Cascade mountains, and is the home of one of the populations of Fraser river sockeye. The equable climate of the region is reflected in the low annual heat budget of the lake and its normal lack of an ice cover in winter, with continued complete or partial circulation of its water throughout that season. Judged by the low degree of hypolimnial oxygen consumption in summer, the lake is to be classed as distinctly oligotrophic. The oxygen content at all depths and seasons is sufficient for the respiration of salmonoid fishes. The water is moderately hard and slightly alkaline. Quantities of dissolved nitrates and phosphates in the water appear to be of the order characteristic of oligotrophic lakes. Silicates are present much in excess of the requirements of the lake's diatom populations. The number of adult sockeye returning to the lake in normal years is insufficient to add to its supply of nutritive salts in significant amount. Temperature observations and oxygen determinations, taken at frequent intervals for several years, have contributed to the knowledge of certain questions of general limnological interest. Such include (1) the manner in which the hypolimnion of a lake is warmed in summer; (2) the classification of the seasonal circulation periods in temperate lakes; and (3) the oxygen content of a lake at the close of vernal circulation, and its use as a standard from which to measure oxygen consumption throughout the summer.

Testing and classification of individual plants for fire behaviour: plant selection for the wildland - urban interface

2010 ◽  
Vol 19 (2) ◽  
pp. 213 ◽  
Author(s):  
Robert H. White ◽  
Wayne C. Zipperer
Keyword(s):  
Oxygen Consumption ◽  
Thermal Analyses ◽  
Flame Height ◽  
Fire Behaviour ◽  
Test Procedures ◽  
Wildland Urban Interface ◽  
Flammability Characteristics ◽  
Oxygen Consumption Calorimetry ◽  
Physical And Chemical

Knowledge of how species differ in their flammability characteristics is needed to develop more reliable lists of plants recommended for landscaping homes in the wildland–urban interface (WUI). As indicated by conflicting advice in such lists, such characterisation is not without difficulties and disagreements. The flammability of vegetation is often described as having four components (ignitability, combustibility, sustainability and consumability). No standards or generally recognised test procedures exist for evaluating these components in plants. Some measurements of flammability include times for ignition, rate of flame spread, flame height and heat release rate. Often, the fire behaviour characteristics of a plant are derived from its physical and chemical characteristics. Thermogravimetric analysis and other thermal analyses of ground samples have long been used to characterise the thermal degradation of vegetation. More recently, researchers have used the oxygen consumption methodology to measure the heat released due to combustion of the vegetation. Although oxygen consumption calorimetry is an improvement in characterising plant flammability, translation of laboratory results to field conditions can be problematic and tests can be expensive.

The Organic Metabolism of Sea-water with Special Reference to the Ultimate Food Cycle in the Sea

1935 ◽  
Vol 20 (2) ◽  
pp. 181-196 ◽  
Author(s):  
Ancel Keys ◽  
E. H. Christensen ◽  
August Krogh
Keyword(s):  
Oxygen Consumption ◽  
Special Reference ◽  
Oxygen Content ◽  
Sea Water ◽  
Raw Water

Studies are reported of the behaviour of stored sea-water with regard to oxygen, ammonia, and bacteria content in relation to the conditions of storage and to the effect of various filtration procedures.When sea-water is sterilised by filtration and stored in the dark, the oxygen content remains constant or diminishes only by less than 0·07c.c. per litre in several hundred hours.In non-sterile experiments there is always an oxygen consumption roughly parallel to a bacterial multiplication which begins very suddenly after collection of the water. These effects are greatest in “raw” water, less in paper-filtered water and least in water which is doubly filtered.

scholarly journals The Function of the Gills of Mayfly Nymphs from Different Habitats

1939 ◽  
Vol 16 (3) ◽  
pp. 363-373 ◽  
Author(s):  
C. A. WINGFIELD
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Content ◽  
The Body ◽  
Gaseous Exchange ◽  
Low Oxygen ◽  
Respiratory Mechanism ◽  
Tracheal Gills ◽  
Cloeon Dipterum ◽  
Gill Function ◽  
Oxygen Concentrations

1. The oxygen consumption of normal and gill-less nymphs of the mayflies Baetis sp., Cloeon dipterum and Ephemera vulgata has been measured at various oxygen concentrations. 2. It has been found that over the complete range of oxygen concentrations studied, the tracheal gills do not aid oxygen consumption in Baetis sp. In Cloeon dipterum, at all oxygen concentrations tested, no gaseous exchange takes place through the gills; at low oxygen concentrations, however, the gills function as an accessory respiratory mechanism in ventilating the respiratory surface of the body and so aid oxygen consumption. In Ephemera Vulgata the gills aid oxygen consumption even at high oxygen concentrations. In this species the gills may function both as true respiratory organs and as a ventilating mechanism. 3. It is shown that the differences in gill function can be related to the oxygen content of the habitat of each species.

scholarly journals A potential antiviral and food-derived healthy ingredient: Resveratrol

2021 ◽  
Vol 7 (1) ◽  
pp. 54-63
Author(s):  
Ayla Arslaner ◽  
Zehra Türkoğlu
Keyword(s):  
Carbon Number ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Food Ingredient ◽  
Beneficial Effects ◽  
Antiviral Effects ◽  
Natural Polyphenol ◽  
Physical And Chemical ◽  
And Chemical Properties

Polyphenols are the secondary metabolites of plants and has an important role in human nutrition as the leading antioxidants. According to the carbon number-based classification of polyphenols, resveratrol is a natural polyphenol in the stilbene group with antioxidant and anticarcinogenic effects. Its beneficial effects on cardiovascular diseases have also been reported. It was first identified in 1940 and has recently gained importance especially in medicine and pharmacy. Researchers have carried out various studies on resveratrol and its time-honored use in traditional eastern medicine has been reported. Resveratrol is a food ingredient that has the potential to be used in the treatment of various diseases, but also has antiviral effects. The study focuses on resveratrol’s physical and chemical properties, effects on health, antiviral effects and use in foods as a functional component.

scholarly journals RESEARCH OF RHEOLOGICAL PROPERTIES OF MEDICINAL SYRUP FOR ORAL USE

2020 ◽  
Vol 73 (4) ◽  
pp. 696-699
Author(s):  
Lena L. Davtian ◽  
Galyna P. Kukhtenko ◽  
Alona S. Voronkina ◽  
Viktoria V. Kudria
Keyword(s):  
Rheological Properties ◽  
Mechanical Stability ◽  
Rheological Parameters ◽  
Dynamic Flow ◽  
Shear Rates ◽  
Coaxial Cylinders ◽  
Low Degree ◽  
Newtonian Type ◽  
Rotary Viscometer

The aim of the present research was to investigate the rheological properties of the medicinal syrup for oral administration with glucosamine hydrochloride and levocarnitine. Matherials and methods: Coefficient of the dynamic flow (at shear rates of 3,49 and 10,3 s -1, as well as at shear rates of 27.2 and 149.0 s-1), mechanical stability, the index of destruction and restoration were studied. The rheological (structural-mechanical) properties of the samples were determined using a Rheolab QC rotary viscometer (AntonPaar, Austria) with coaxial cylinders CC27 / S-SN29766. The rheological parameters were studied at the temperature 20±0,5 °С. Results: It is established that the syrup has weakly expressed plastic viscous and thixotropic properties (the hysteresis area for the syrupis 1710.19 Pas/s). Such results characterize the system as a reopex. Conclusions: The results of the study enables classification of the research object as system with a low degree of fluidity. Such dependence is typical for systems of the Newtonian type of flow and characterizes the syrup under investigation as a weakly structured disperse system.

Cardiovascular changes in the exercising emu

1983 ◽  
Vol 104 (1) ◽  
pp. 193-201 ◽  
Author(s):  
B. Grubb ◽  
D. D. Jorgensen ◽  
M. Conner
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Oxygen Consumption ◽  
Stroke Volume ◽  
Oxygen Content ◽  
Body Mass ◽  
Fold Increase ◽  
Exercise Heart Rate ◽  
Rate Of Oxygen Consumption ◽  
Cardiovascular Variables

Cardiovascular variables were studied as a function of oxygen consumption in the emu, a large, flightless ratite bird well suited to treadmill exercise. At the highest level of exercise, the birds' rate of oxygen consumption (VO2) was approximately 11.4 times the resting level (4.2 ml kg-1 min-1). Cardiac output was linearly related to VO2, increasing 9.5 ml for each 1 ml increase in oxygen consumption. The increase in cardiac output is similar to that in other birds, but appears to be larger than in mammals. The venous oxygen content dropped during exercise, thus increasing the arteriovenous oxygen content difference. At the highest levels of exercise, heart rate showed a 3.9-fold increase over the resting rate (45.8 beats min-1). The mean resting specific stroke volume was 1.5 ml per kg body mass, which is larger than shown by most mammals. However, birds have larger hearts relative to body mass than do mammals, and stroke volume expressed per gram of heart (0.18 ml g-1) is similar to that for mammals. Stroke volume showed a 1.8-fold increase as a result of exercise in the emus, but a change in heart rate plays a greater role in increasing cardiac output during exercise.

Study of recrystallization kinetics of aluminium alloy 1565ch with low degree of cast structure conditioning

2021 ◽  
pp. 58-64
Author(s):  
V. V. Yashin ◽  
◽  
I. A. Latushkin ◽  
E. S. Chitnaeva ◽  
E. V. Aryshensky ◽  
...  
Keyword(s):  
Temperature Drop ◽  
High Rate ◽  
Recrystallization Temperature ◽  
Growth Speed ◽  
Recrystallization Process ◽  
Russian Science ◽  
Cast Structure ◽  
Recrystallization Kinetics ◽  
Low Degree

The present study addresses recrystallization process in Al – Mg 1565ch system alloy samples (Russian classification). The samples are taken from cast ingot, produced by continuous casting in DC mold and homogenized based on standard commercial mode. Then the samples were heated to 350–500 oC and rolled in lab mill with different process schedules to cover the entire range of temperature and strain rates, applied in rolling. After rolling the samples were annealed at 350, 400 and 450 oC, their resultant microstructure was examined by optic microscope. The rate of new grains nucleation, their growth speed, analytical notations, describing recrystallization kinetics, were obtained within the frames of the study to be applied during this alloy recrystallization modelling; the main alloy-specific recrystallization features were identified and compared with alloy АА5182 (classification of American Aluminum Association). It is demonstrated, that 1565ch recrystallization has a number of specific features in case of as-cast structure deformation with low strain levels (ε = 0.14÷0.56): first, high rate of new grains nucleation; second, low grain growth speed to the extent of complete process blocking. Optimal recrystallization temperature is identified as 400 oC, at this temperature the process is over 75% complete, the temperature drop (350 oC) causes incubation period extension, while recrystallization subsides at recrystallized structure volume of about 30%, in case of temperature rise (450 oC) the structure is saturated with fine new grains nuclei, probably, emerging during heating, but due to high intensity of recovery and polygonization, recrystallization driving force drops to zero, the process stops with mixed structure and max recrystallized grains volume of 20%. This research was funded through a grant by the Russian Science Foundation, Project 18-79-10099.

Preparation for Advanced Airway Management: Pre-oxygenation and Positioning

2019 ◽  
Author(s):  
Arpan Mehta ◽  
Adrian Pichurko
Keyword(s):  
Oxygen Consumption ◽  
Airway Management ◽  
Oxygen Content ◽  
High Flow ◽  
Nasal Cannula ◽  
Blood Oxygen ◽  
High Flow Nasal Cannula ◽  
Advanced Airway ◽  
Total Body ◽  
Total Body Oxygen

Preoxygenation allows a margin of safety prior to establishing control of a patient’s airway. Effective preoxygenation is influenced by careful technique, respiratory physiology, blood oxygen content, and total body oxygen consumption. Total body oxygen consumption is increased in the pregnant, pediatric, and obese populations, making maintenance of oxygenation more difficult during apnea. In addition to a standard facemask, advanced equipment such as high-flow nasal cannula, THRIVE, and various mask variants may be used. Positioning of a patient for advanced airway management affects preoxygenation, respiratory mechanics, and the conditions for establishing a definitive airway. The “triple airway support” maneuver consists of head extension, neck flexion, and protrusion of the mandibular teeth over the upper teeth; and provides effective mechanics for positive-pressure mask ventilation. Patients with potentially unstable cervical spines present additional challenges and, especially in emergency situations, require careful negotiation of priorities. Common maneuvers such as head tilt, jaw thrust, cricoid pressure, and manual in-line stabilization can cause motion in the unstable cervical spine with uncertain effects.  This review contains 7 figures, 5 tables, and 43 references. Keywords: preoxygenation, functional residual capacity, blood oxygen content, alveolar fraction of oxygen, total body oxygen consumption, high-flow nasal cannula, apneic oxygenation, sniffing position, triple airway support maneuver, manual in-line stabilization

Relation of coronary flow to oxygen supply

1960 ◽  
Vol 199 (1) ◽  
pp. 179-182 ◽  
Author(s):  
Abraham Guz ◽  
George S. Kurland ◽  
A. Stone Freedberg
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Oxygen Content ◽  
Coronary Flow ◽  
Constant Pressure ◽  
Rabbit Heart ◽  
Hemoglobin Solution ◽  
Oxygen Capacity ◽  
Locke Solution ◽  
Solution Change

Coronary flow, heart rate, myocardial oxygen consumption and Walton strain gauge tension were determined in the isolated rabbit heart perfused with hemoglobin solutions of varying oxygen content. Perfusion was carried out under constant pressure and with the hemoglobin solution in equilibrium with 3% CO2 and 97% air under atmospheric tension. Oxygen content was varied from 2 to 18 vol. % by diluting hemoglobin with Ringer-Locke solution. Change from a higher to lower oxyhemoglobin concentration resulted in increased coronary flow; the reserve led to decreased flow. Heart rate, myocardial tension and oxygen consumption were constant at oxygen capacity above 2 vol. %.

Phase rule classification of physical and chemical critical effects in liquid mixtures

2019 ◽  
Vol 729 ◽  
pp. 73-78 ◽  
Author(s):  
James K. Baird ◽  
Xingjian Wang ◽  
Joshua R. Lang ◽  
Pauline Norris
Keyword(s):  
Liquid Mixtures ◽  
Phase Rule ◽  
Physical And Chemical
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