Showing papers by "University of Rhode Island published in 1975"
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01 Jan 1975TL;DR: In the more than 15 years since the second edition of the Fundamentals of Machining and Machine Tools was published, the industry has seen many changes Students must keep up with developments in analytical modeling of machining processes, modern cutting tool materials, and how these changes affect the economics as discussed by the authors.
Abstract: In the more than 15 years since the second edition of Fundamentals of Machining and Machine Tools was published, the industry has seen many changes Students must keep up with developments in analytical modeling of machining processes, modern cutting tool materials, and how these changes affect the economics of machining With coverage reflecting s
482 citations
TL;DR: A comparison of enrichment factors relative to average crustal material for the remainder of these elements over the North Atlantic with enrichment factors for similar samples collected at the geographic South Pole suggests that the anomalously high enrichment factors may be due to natural rather than anthropogenic sources.
Abstract: The chemical composition of atmospheric particles collected near sea level over the North Atlantic indicates that Al, Sc, Mn, Fe, Co, Cr, Na, Mg, Ca, K, and Sr are derived from either crustal weathering or the ocean. The elements V, Zn, Cu, Cd, Pb, Sb, and Se are present in concentrations higher than expected from these sources. Although the V is probably derived from pollution sources on the North American continent, a comparison of enrichment factors relative to average crustal material for the remainder of these elements over the North Atlantic with enrichment factors for similar samples collected at the geographic South Pole suggests that the anomalously high enrichment factors may be due to natural rather than anthropogenic sources. A vapor phase for these metals may be involved at their source.
405 citations
TL;DR: In this paper, rare earths (RE) in basalts erupted within the rift of the Mid-Atlantic Ridge show a progressive change from light-RE enriched to depleted patterns from the Azores Platform (40°N) down to 33°30′N.
289 citations
TL;DR: Oxygen isotopic measurements in three Late Quaternary deep-sea cores from the Gulf of Mexico record a major anomaly between about 15,000 and 12,000 years ago superimposed on a more characteristic oceanic oxygen isotopic curve.
Abstract: Oxygen isotopic measurements in three Late Quaternary deep-sea cores from the Gulf of Mexico record a major anomaly between about 15,000 and 12,000 years ago superimposed on a more characteristic oceanic oxygen isotopic curve. This resulted from major influx of isotopically light glacial meltwater via the Mississippi River from the disintegrating Late Wisconsin Laurentide Ice Sheet 2000 kilometers to the north.
226 citations
TL;DR: It is concluded that acute administration of narcotic drugs results in an inhibition of dopamine-receptor activity while chronic administration of these drugsresults in an increased response of these dopamine receptors to dopamine agonists.
217 citations
TL;DR: It was found that excellent resolution of the majority of the nucleotides was obtained at ambient temperatures and the retention times, peak shapes, heights and areas were highly reproducible and there was good linearity of response.
214 citations
TL;DR: The ash distribution in the deep-sea sections, which span the last 20 million years, indicates that there has been a much higher rate of explosive volcanism from both island arc and hot spot volcanoes during the last 2 million years.
Abstract: The worldwide distribution of volcanic ash has been determinmined from 320 deep-sea sections drilled during the Deep Sea Drilling Project. The ash distribution in the deep-sea sections, which span the last 20 million years, indicates that there has been a much higher rate of explosive volcanism from both island arc and hot spot volcanoes during the last 2 million years. This episode, and perhaps another in the Middle Miocene cprrelates with previously reported widespread synchronism in increased volcanicity in certain oceanic islands. Increased Quaternary volcanism coincides approximately with that episode of the Cenozoic marked by major and rapidly fluctuating climatic change.
171 citations
TL;DR: Employing the perspective of labeling theory, this paper proposes that causes of abuse are products of social definitions applied by gatekeepers charged with identifying children injured by their caretakers.
Abstract: Research on child abuse has traditionally focused on incidence, causes, and prevention and treatment One facet overlooked is that abuse is social deviance, and is the product of social labeling Employing the perspective of labeling theory, this paper proposes that causes of abuse are products of social definitions applied by gatekeepers charged with identifying children injured by their caretakers Gaps in our knowledge of child abuse are pointed out, and suggestions for empirical research are offered
152 citations
TL;DR: The high growth rates and assimilation numbers usually found suggest that the phytoplankton in lower Narragansett Bay was not generally nutrient-limited between November, 1972 and October, 1973; Nutrient regeneration in this shallow estuary must be very rapid when in situ nutrient levels are low.
Abstract: The composition and productivity of four different size-fractions ( 100 μm) of the phytoplankton of lower Narragansett Bay (USA) were followed over an annual cycle from November, 1972 to October, 1973. Diatoms dominated the population in the winter-spring bloom and in the fall, the summer population was dominated by flagellates. The nannoplankton ( 20 μm) were the most important. Nannoplankters domnated in the summer. The yearly mean assimilation numbers for the different fractions were not signfficantly different. During the winter-spring bloom, however, the assimilation numbers for the netplankters were significantly higher than those for the nannoplankton fraction. Temperature accounted for most of the variability in assimilation numbers; a marked nutrient stress was observed on only two occasions. Growth rates calculated from 14C uptake and adenosine triphosphate (ATP)-cell carbon were generally quite high; maxima were >1.90 doublings per day during blooms of a flagellate in the summer and of Skeletonema costatum in the fall. The series of short cycles observed in which the dominant species changed were related to changes in the physiological state of the population. Higher growth rates were generally observed at times of peak phytoplankton abundance while lower growth rates were observed between these peaks. The high growth rates and assimilation numbers usually found suggest that the phytoplankton in lower Narragansett Bay was not generally nutrient-limited between November, 1972 and October, 1973. Nutrient regeneration in this shallow estuary, therefore, must be very rapid when in situ nutrient levels are low.
141 citations
TL;DR: In this paper, the GATE Equatorial Oceanographic Experiment (GATE) was used to observe the South Equatorial Current and the Equatorial Undercurrent with time scales of 2-3 weeks.
Abstract: Observations from the GATE Equatorial Oceanographic Experiment are presented. They reveal large scale meandering of the westward flowing South Equatorial Current and of the eastward flowing Equatorial Undercurrent with time scales of 2–3 weeks. Meandering of the flow pattern was found to be related to corresponding displacements of the high salinity core of the undercurrent. The observations tend to support the assumption of a long wave propagating westward with a phase speed of 2.3 m s−1 and a wavelength of 3,200 km. A possible explanation may be given in terms of unstable waves caused by large scale horizontal shear in the Equatorial Current System.
138 citations
TL;DR: In this article, the general form of ridge regression proposed by Hoerl and Kennard is examined in the context of the iterative procedure they suggest for obtaining optimal estimators.
Abstract: The general form of ridge regression proposed by Hoerl and Kennard is examined in the context of the iterative procedure they suggest for obtaining optimal estimators. It is shown that a non-iterative, closed form solution is available for this procedure. The solution is found to depend upon certain convergence/divergence conditions which relate to the ordinary least) squares estimators. Numerical examples are given.
TL;DR: The results suggest that the large schools of menhaden found in Atlantic coastal waters could have a significant effect on the plankton, selectively grazing zooplankton, larger phytoplankon, and the longer chains of chain-forming diatoms.
Abstract: The feeding behavior of adult Atlantic menhaden (Brevoortia tyrannus) upon 5 species of phytoplankton and 2 species of zooplankton has been studied. Four recognizable feeding stages which were a function of the concentration and size of the food particles were observed. During rapid feeding the fish swam at a constant speed for a prolonged period over a wide range of particle concentrations. Particle and food carbon-concentrations at the threshold for initiation and termination of feeding were inversely related to particle size. Carteria chuii (13.2 μ) was not grazed at a significant rate, while two-cell chains of Skeletonema costatum (16. 5 μ) were filtered from the water, indicating a minimum-size threshold for filtration of between 13 and 16 μ. The most rapid filtering rates were observed for the copepod Acartia tonsa (\(\bar x\) volume swept clear = 24.8 l/fish/min). The maximum food-particle size acceptable to a menhaden appears to be between Acartia tonsa (1200 μ) and adult Artemia salina (10 mm). These results suggest that the large schools of menhaden found in Atlantic coastal waters could have a significant effect on the plankton, selectively grazing zooplankton, larger phytoplankton, and the longer chains of chain-forming diatoms.
TL;DR: In this paper, the authors reported a gradient in sediment activity that increased from an annual mean of 20 ± 8·8 g m−2 day−1 at the head of the estuary to 51 ± 16·7 gm−2 m−1 day−2 at the mouth of the bay.
TL;DR: In this paper, the adsorption of copper and cobalt from aqueous solution on to illite and other substrates has been studied as a function of pH, solution composition and solid phase concentration.
TL;DR: It was previously shown that hypertension elevates collagen biosynthesis and increases collagen deposition in peripheral arteries and that antihypertensive agents prevent and reverse the increased synthesis and these findings have now been extended to the microvessels of the central nervous system and to other small vessels.
Abstract: It was previously shown that hypertension elevates collagen biosynthesis and increases collagen deposition in peripheral arteries and that antihypertensive agents prevent and reverse the increased ...
TL;DR: This paper compares various actions of haloperidol or other neuroleptics with morphine or other narcotic analgesics using the same testing parameters in the hope that such a comparison would evaluate the role of dopamine receptors in narcotic action and narcotic dependence.
TL;DR: Understanding of relationships between epiphytes and seagrasses might be useful for suppression of growth where epipHYtes are unwanted; promotion, where they are considered desireable; and observation of epip hytes to monitor environmental changes in seagRass communities.
TL;DR: In this paper, the authors derive recreational demand functions consistent with utility maximization to address specific issues in empirical research, such as data shortcomings, theoretical problems, and measurement of the value of recreational facilities which are comparable to market values for competing activities.
Abstract: research is to provide nonmarket measures of the value of recreational facilities which are comparable to market values for competing activities. Measurement of the value of recreational facilities has been beset by data shortcomings and theoretical problems, and, as indicated in an article by J. A. Sinden recently published in this Journal, some of the perennial research problems remain. The purpose of this paper is to derive recreation demand functions consistent with utility maximization to address specific issues in empirical research. Outdoor recreation demand functions are used to
TL;DR: Four toxins have been isolated by Sephadex G-15 and high pressure ion exchange chromatography from the soft shell clams, Mya arenaria, which were collected during 1972 and 1974 red tide outbreaks on the New England coast.
TL;DR: In this paper, the high-temperature chemical stability of hot-pressed Si3N4 was studied between 600° and 1450°C. Reactions were followed by X-ray diffraction and scanning electron microscopy.
Abstract: The high-temperature chemical stability of hot-pressed Si3N4 was studied between 600° and 1450°C. Reactions were followed by X-ray diffraction and scanning electron microscopy. In air, this material begins to oxidize at 700° to 750°C; a distinct amorphous siO2 surface layer results after 24 h at 750°C-Concomitant formation of cristobalite occurs, depending on exposure time, and is enhanced as temperature is Increased. Magnesium and calcium magnesium silicates form above 1000°C. The data suggest that impurities, e.g. Mg, Ca, and Fe, greatly lower the oxidation resistance of Si3N4 in air.
TL;DR: The ability of high molecular weight chlorinated hydrocarbons to be transported long distances through the atmosphere has been well established within the past decade as mentioned in this paper, and it has been reported that toxaphene is also carried through at least 1,200km out to sea.
Abstract: OVER the past ten years toxaphene has been used in the USA in larger quantities than any other insecticide, with an estimated consumption of 58 million pounds per year (ref. 1). In spite of this widespread use, the composition of toxaphene remains largely undetermined, and recent work indicates that the technical product contains nearly 200 polychlorinated camphenes2. Because of the difficulties in analysing such a complex mixture, little is known about the dissipation of toxaphene in the environment. Residues in soils may persist for years, with volatilisation suggested as a major loss mechanism3. Toxaphene has been identified, however, in US air samples in only three locations4, all in southern agricultural areas, at levels of 16–2,520 ng m−3. The ability of high molecular weight chlorinated hydrocarbons to be transported long distances through the atmosphere has been well established within the past decade. Polychlorinated biphenyls (PCBs)5,6, and the chlorinated pesticides DDT6–9, dieldrin7,9, and chlordane6 have been identified in the air over the western North Atlantic. We now report that toxaphene is also carried through the atmosphere at least 1,200km out to sea.
TL;DR: In this paper, the authors examined the bubble transport of POC and trace metals to the sea surface by rising bubbles in samples of surface water collected in Narragansett Bay.
TL;DR: Fourteen species of sergestid shrimps were collected in the Sargasso Sea between the surface and 1500 m near Bermuda on 4 cruises and Morphological differences in the third maxillipeds of these species suggest differences in feeding.
Abstract: Fourteen species of sergestid shrimps were collected in the Sargasso Sea between the surface and 1500 m near Bermuda on 4 cruises. The vertical distribution and feeding activity of the most abundant species are discussed in relation to interspecific competition and the adaptive significance of vertical migration. Each species lives within a narrow depth range and exhibits a diel vertical migration. Sergestes splendens migrated as much as 825 m, while S. japonicus migrated less than 100 m. Neither the seasonal nor permanent thermocline influenced the migration range. The only species which occurred together both day and night were S. pectinatus with S. vigilax and S. pectinatus with S. sargassi. Morphological differences in the third maxillipeds of these species suggest differences in feeding. Although most species eat a variety of organisms, the foreguts of S. grandis, S. corniculum, and S. splendens contained euphausiids more often than those of other species, and S. grandis and S. robustus fed more frequently on fishes. In contrast, S. japonicus appears to feed on detritus. Food was found in the foreguts of most species less frequently during the day than night, but no species fed only at night. S. sargassi and S. pectinatus fed equally day and night.
TL;DR: Neurochemical evidence for super-sensitivity of dopamine receptors after chronic treatment with neuroleptics is provided, and the threshold dose of apomorphine to inhibit dopamine turnover was reduced.
TL;DR: Three thermophilic cellulolytic fungi, Chaetomium thermophile var.
Abstract: Three thermophilic cellulolytic fungi, Chaetomium thermophile var. coprophile, Sporotrichum thermophile, and Thermoascus aurantiacus were studied to determine the conditions for a high rate of cellulose degradation. The range of temperature over which good growth occurred was determined first in a temperature gradient incubator; the optimum temperature was then established in shake flask cultures. T. aurantiacus had the highest optimum growth temperature range (46 to 51 C), whereas S. thermophile had the broadest range over which good growth occurred (36 to 43 C). Optimum temperatures for the three organisms, T. aurantiacus, S. Thermophile, and C. thermophile were 48, 40, and 40 C, respectively. It was found that the addition of an organic carbon and nitrogen source to a cellulose mineral solution medium markedly increased the rate of cellulose degradation. The surfactant, Tween 80, which has been reported to be of value in the production and recovery of the enzyme, cellulase, was shown to be detrimental to the degradation of cellulose in culture. In the medium used, S. thermophile gave the highest rate of substrate utilization; 56% of the cellulose was hydrolyzed in 72 h. The average degree of polymerization of cellulose decreased from 745 to 575.
TL;DR: The results suggest that increased NH3 excretion is part of the early response to hypo-osmotic stress in both species, that increased FAA release does not occur, and that movement of FAA from cells into body fluids is not part ofThe early response in the crab.
TL;DR: In this article, the results indicate that V, Cr and Mn have a clear preference for the Fe site with 8 Fe first neighbors, while Co for Fe sites with 4 Fe and 4 Si first neighbors and only tentative conclusions can be drawn for Ta and W.
TL;DR: Paleomagnetic, radiolarian, and foraminiferal studies of piston cores from the Ross Sea, Antarctica, reveal the existence of a widespread disconformity separating sediments of Gauss age (t > 2.4 m.y.) from a thin discontinuous layer of Brunhes sediments (t 1,800 to
Abstract: Paleomagnetic, radiolarian, and foraminiferal studies of piston cores from the Ross Sea, Antarctica, reveal the existence of a widespread disconformity separating sediments of Gauss age (t > 2.4 m.y.) from a thin discontinuous layer of Brunhes sediments (t 1,800 to