Showing papers on "Particulates published in 1969"
TL;DR: The data suggest that at higher elevations in the White Mountains avalanches are probably a more important denudational force by an order of magnitude than solution and slower mass movements.
Abstract: Particulate matter losses from the Hubbard Brook watershed-ecosystems show seasonal variations, with the bulk of the material being exported during the spring runoff period. However, a single autumnal storm of unusual intensity accounted for 54% of the total particulate matter output during a 2-year period. Total particulate matter losses amounted to 2.5 metric tons/km2/year. This value is appreciably less than values reported for other similar regions. Total output of dissolved substances was 14 metric tons/km2/yr. This is about 25% of the dissolved load predicted for such areas by Langbein and Dawdy (Leopold et al., 1964). The relatively small losses of dissolved substances and particulate matter indicate that the Hubbard Brook ecosystem is very stable. This is also supported by the biotic structure of the ecosystem. Chemicals may be exported from various compartments of the ecosystem as particulate or dissolved organic material from the organic compartment, dissolved inorganic substances from the available nutrient compartment, and inorganic particulate matter from the soil and rock mineral compartment. The route of export an element follows is a function of its geochemistry, its utilization by the biological components, and its differential accumulation within the ecosystem. Although debris avalanches are not an important consideration at Hubbardmore » Brook, our data suggest that at higher elevations in the White Mountains avalanches are probably a more important denudational force by an order of magnitude than solution and slower mass movements. Secondary ecological successions following severe disturbance of forest ecosystems result in significant conservation of nutrients lost from the ecosystem. This effect is achieved by a complex interaction of biomass accumulation, alteration of the hydrolic cycle, reduction of erodibility of the system, and changes in concentration of dissolved substances in drainage waters.« less
162 citations
TL;DR: The metabolism of the water-extractable carbohydrate in the euphotic zone and its underlying layer is discussed, indicating that it was lost from the particulate matter much faster than the other particulate organic constituents such as protein and water-insoluble carbohydrate.
Abstract: We have studied carbohydrate metabolism in the marine environment by means of the isolation and characterization of carbohydrates of particulate matter from various depths. The present work is especially concerned with water-extractable carbohydrates of the particulate samples from 11 stations of the northwest Pacific Ocean. Water-extractable carbohydrate content in the particulate matter of the surface waters was measured; it ranged from 19.2 to 36.0% of the total particulate carbohydrate. These values decreased, ranging from 6.5 to 15.5% at 50 m depth. Such rapid vertical change of the concentration of the carbohydrate indicated that it was lost from the particulate matter much faster than the other particulate organic constituents such as protein and water-insoluble carbohydrate. This process left water-insoluble carbohydrate in the deep-water particulate matter as previously observed in the Sagami Nada, off eastern Honshu, Japan. Upon acid hydrolysis, water-extractable carbohydrate revealed glucose ranging from 67.0 to 84.2%. Rhamnose, fucose, ribose, arabinose, xylose, mannose and galactose were also identified as components of the carbohydrate fraction. Carbohydrate studies on the laboratory cultured diatoms clearly indicated that the water-extractable carbohydrates were food reserve materials of the diatoms. In view of this fact, the metabolism of the water-extractable carbohydrate in the euphotic zone and its underlying layer is discussed.
94 citations
TL;DR: Analysis of particulate matter from various depths at Sagami Nada indicates that 1,3-glucan and its related low molecular weight carbohydrates from the water-soluble fraction decay between 50 and 300 m depth, to leave waterinsoluble carbohydrates, immune to biological attack during the course of further sinking.
Abstract: Detailed profiles of organic carbon, organic nitrogen, carbohydrate and proteinous amino acid have been determined in particulate matter from various depths at a station in Sagami Nada off eastern Honshu, Japan. The profiles suggest that carbohydrate is decayed from particulate matter more rapidly than proteinous amino acid in the euphotic zone, while the latter is removed to a higher extent than the former in deep waters,which results in the increase of the C/N values of particulate matter in the depths. All of the particulate matter gave D-galactose, D-glucose, D-mannose, D-xylose and D-glucuronic acid upon acid hydrolysis. Vertical change of the monosaccharide composition of this particulate matter indicates that only D-glucose and its polymers are preferentially removed from it during its descent. Carbohydrates from the particulate matter of 20 m depth were fractionated into water-soluble and insoluble carbohydrates. Detailed analysis of these fractions indicates that 1,3-glucan and its related low molecular weight carbohydrates from the water-soluble fraction decay between 50 and 300 m depth, to leave waterinsoluble carbohydrates, immune to biological attack during the course of further sinking. On the basis of these facts, the effects of the biochemical nature of these carbohydrates on the vertical change of the particulate carbohydrate distribution are discussed.
94 citations
TL;DR: Quantitative data from over 500 concentrates of suspended particulate material has been summarized statistically for the Atlantic, Pacific, and Indian oceans, the Gulf of Mexico, and the Caribbean Sea.
Abstract: Quantitative data from over 500 concentrates of suspended particulate material has been summarized statistically for the Atlantic, Pacific, and Indian oceans, the Gulf of Mexico, and the Caribbean Sea. From clear ocean water a majority of samples were in the range of 0 to 9.9 milligrams per 200 liters and the next largest number were in the range of 10 to 19.9 milligrams per 200 liters. Certain areas of cloudy or nepheloid water, observed photographically, contain relatively more samples in heavier concentration ranges and have larger mean values than clear ocean water.
60 citations
TL;DR: In this article, the authors made simultaneous measurements of the concentrations of cloud condensation nuclei, sodium-containing particles, Aitken nuclei and the magnitude of the light scattering coefficient of the air, for a period of two months in the Olympic Mountains of Washington State.
Abstract: Simultaneous measurements have been made of the concentrations of cloud condensation nuclei, sodium-containing particles, Aitken nuclei, and the magnitude of the light scattering coefficient of the air, for a period of two months in the Olympic Mountains of Washington State. Large short-term changes in the magnitudes of these four quantities were found to be related to variations in the local meteorological conditions. The most striking changes occurred with the build up and the evaporation of cumulus clouds upwind of the measuring site. The results indicate that growing clouds absorb (and also probably generate) large numbers of particulates, and that these particulates are released when the clouds dissipate. Precipitation also caused significant reductions in the concentrations of particulates in the air. Longer period variations in particulate concentrations were associated with the diurnal convective cycle and changes in air mass. Continental air contained higher concentrations of cloud conde...
56 citations
TL;DR: Commercial high density poultry houses contain high concentrations of airborne particulate matter, which are related to the bodily activity of the birds and to the atmosphere of a swine confinement building, and several very volatile, low molecular weight compounds were found.
31 citations
Patent•
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11 Sep 1969
TL;DR: In this article, an impact sensor is used to measure the mass flow rate of particulate matter, such as flour, salt, grains, soap powder, sand, gravel, cement, sawdust and the like.
Abstract: Apparatus for measuring the mass flow rate of particulate matter, such as flour, salt, grains, soap powder, sand, gravel, cement, sawdust and the like, using an impact sensor onto which the particulate matter is dropped in free fall through a substantially constant predetermined height. The sensor has an upwardly directed sharp edge or point and inclined surfaces and moves bodily in a substantially straight line, vertical direction only. The particulate matter is directed by inclined surfaces against vertical guide surfaces which direct the particulate matter to drop vertically onto the inclined sensor surfaces through a substantially constant, free fall distance. The average impulse of force applied to the sensor by the dropping particulate matter deflects it vertically to provide a measure of the rate of mass flow of the particulate matter through the apparatus. The displacement of the sensor is small with respect to the distance of particulate fall.
28 citations
26 citations
TL;DR: The particulate and trace gas content of polar air is very similar to that of tropical air despite diflerences in climatology and biotic activity.
Abstract: The particulate and trace gas content of polar air is very similar to that of tropical air despite diflerences in climatology and biotic activity. biologic particulates and moisture.
23 citations
13 citations
TL;DR: In this paper, the authors show that concentrations of particulate iron and aluminum in river and shelf waters of the eastern United States are indirectly related to salinity, but show a loss greater than that expected from simple mixing.
TL;DR: A 56-day survey of suspended paniculate and iron concentrations in the Windsor area is reported in this paper, where the two pollutants show different spatial patterns due to the presence of very local sources of iron oxide.
TL;DR: The relationship between pollution by particulate matter and cloud formation is discussed, as are persistence of fog and the observation that certain sources of particulate pollution are also sources of ice nuclei.
Abstract: The role of particulate matter and oxides of sulfur in degradation of the atmospheric environment is discussed. The Federal Air Quality Criteria for these pollutants are analyzed for their conformance with the requirement of the Clean Air Act of 1967 that they reflect the latest scientific knowledge pertinent to the indication of their effects on health and welfare. Visibility reduction by suspended particulate matter is treated and the bases for the criteria issued in the documents “Air Quality Criteria for Particulate Matter” and “Air Quality Criteria for Sulfur Oxides” are examined. The reactions between particulate matter and gaseous pollutants are discussed, along with the Impact of particulate matter on modifications of weather processes. Local effects, such as precipitation, are considered. The relationship between pollution by particulate matter and cloud formation is discussed, as are persistence of fog and the observation that certain sources of particulate pollution are also sources of ice nuclei.
TL;DR: In this paper, the stiffness index appears insensitive to change in hook-wire diameter above a certain minimum value, and the minimum is larger for finer fibers when tested at the same load, without causing any appreciable relaxation or set of the test fiber in the hook vicinity.
Abstract: Fig. 1. Bending test schematic using hair fiber photograph. Guide Ear is a plastic ruler marked in millimeter divisions. Human-hair fibers of 50-100 microns in diameter were measured at constant temperature and humidity using a 0.77-mm hook and 0.2 g attached to each end. A guide bar is brought into light contact with the fiber legs to hold the fiber plane perpendicular to the optical axis of a horizontal cathetometer used for measurement. As a precaution, fibers should be esaniined after each measurement to ensure absence of set. The stiffness index appears insensitive to change in hook-wire diameter above a certain minimum value. The minimum is larger for finer fibers, when tested at the same load. It is suggested for any series of tests that a suitable hook wire be selected as a test constant. The load T should be adjusted to give a convenient magnitude to the distance d, without causing any appreciable relaxation or set of the test fiber in the hook vicinity. In general, changing T by a factor of k causes the distance d to change by a factor of 1 / v T a n d causes the maximum bending moment (theoretical for a point contact of hook and fiber) to change by a factor of gx Weights are conveniently attached by threadingthe fiber end through a short length of plastic tubing and inserting a tapered metal pin. The combined weight of pin and tubing is known and the contribu-
01 May 1969
07 Jan 1969
Abstract: : Dissemination of microorganism-bearing aerosols in dental operatories has raised questions about potential risks of airborne infection. The purpose of this study was to evaluate methods of reducing microbial concentrations in such aerosols. Measurements were made of the influence of particulate matter on airborne bacteria and the effectiveness of an 800-cfm high-efficiency particulate air (HEPA) filter unit in reducing airborne bacteria. A room, approximately 700 ft3 in size, was constructed of plastic material, and was kept sealed except for an intake of dust-free, bacteria-free air. The fallout rate of Bacillus subtilis spores was determined in a dust-free environment and also in the presence of known amounts of airborne particulate matter: 3.0 to 15.0 gm of Ca3(PO4)2 powder, or 0.3- or 1.0-gm of hair spray. The fallout rate of the spores (32 percent per hour) was found to increase with the addition of either form of particulate matter, resulting in a maximum 2-fold increase with 5 gm of powder, and a 1.6-fold increase with 1 gm of spray. The HEPA filter unit was effective in reducing peak concentrations of airborne bacteria by 35 percent, and in clearing the room of all airborne spores in 8-10 minutes. (Author)
TL;DR: Atmospheric CO2, water vapor, net oxidant, and suspended particulate matter were measured at the Blue glacier field station, Mount Olympus, Washington, during the summer of 1966 as mentioned in this paper.
Abstract: Atmospheric CO2, water vapor, net oxidant, and suspended particulate matter were measured at the Blue glacier field station, Mount Olympus, Washington, during the summer of 1966. Diurnal variations of CO2, net oxidant, and water vapor are related to mountain and valley wind transport. Diurnal variations of CO2 and net oxidant have a phase nearly opposite to the typical diurnal variations in the rural lowlands. Concentrations of suspended particulate matter are lower than the concentrations of the urban and industrial areas of the Puget Sound region but generally follow the fluctuations of lowland concentrations.
31 Oct 1969
TL;DR: Tests have been performed on administration sets, syringes and needles confirming the findings of others that these devices themselves can frequently be the major antagonists in yielding particle-free I.V. solutions, and it is not yet possible to produce completely particle- free solutions.
Abstract: The introduction of particulate matter into the bloodstream has been found-both experimentally with animals and clinically with patients-to cause blockages of minor blood vessels and capillaries in key organs of the body. The most common results have been lesions and granulomas in the capillaries of the lung. The particulate matter is generally introduced into the vascular system by means of intravenous injection and infusion. Once introduced, there the contaminant will remain, the vascular system being a highly intricate, closed loop. The particulate matter will circulate in the bloodstream until it eventually finds its way into a blood vessel that is too small for it to pass. The resulting block prevents further blood circulation to the tissues in the area. In addition, there may be many types of reactions to the particulate matter by the body, such as the buildup of giant cells around it, but all result in the closure of the vessel.'-3 All administered intravenous solutions share in the dilemma, since all contain particulate matter in varying amounts, kinds, and sizes. Although the problem is recognized by the pharmaceutical industry, and vast sums are currently being diverted toward the production of particle-free I.V., it is not yet possible to produce completely particle-free solutions. The vast network of production apparatus in the pharmaceutical company precludes the achievement of a 100 percent particle-free product. Pipelines, valves, tanks, threaded connections, airborne matter and, especially, media-migrating fibrous filters all combine to contaminate the bulk product. Added particulate agents contributed by insufficiently cleaned bottles or vials and their rubber stoppers, as well as particles of glass and pieces of rubber, further complicate the problem.4--6 It is not enough to point accusingly at the I.V. solutions themselves. The solutions are administered to the patients with devices that by test have been shown to contribute at least as much and often far greater amounts of matter to the solution. Tests have been performed on administration sets, syringes and needles confirming the findings of others that these devices themselves can frequently be the major antagonists in yielding particle-free I.V. In view of the fact that the solutions and administration devices are most certainly contributing particles to the I.V., quality-control checks on them are