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Sample records for 1930s dust bowl

  1. On the Cause of the 1930s Dust Bowl

    NASA Technical Reports Server (NTRS)

    Schubert, Siegfried D.; Suarez, Max J.; Pegion, Philip J.; Koster, Randal D.; Bacmeister, Julio T.

    2004-01-01

    The 1930s was characterized by a decade of rainfall deficits and high temperatures that desiccated much of the United States Great Plains. Numerous dust storms created one of the most severe environmental catastrophes in U.S. history and led to the popular characterization of much of the southern Great Plains as the Dust Bowl . In this study, we show that the origin of the drought was in the anomalous tropical sea surface temperatures that occurred during that decade. We further show that interactions between the atmosphere and the land surface were essential to the development of the severe drought conditions. The results are based on simulations with the NASA Seasonal-to-Interannual Prediction Project general circulation model forced with observed and idealized sea surface temperatures. We contrast the 1930s drought with other major droughts of the 20th century, and speculate on the possibility of another Dust Bowl developing in the foreseeable future.

  2. On the Causes of the 1930s Dust Bowl

    NASA Technical Reports Server (NTRS)

    Schubert, Siegfried; Suarez, Max; Pegion, Philip; Koster, Randal; Bacmeister, Julie

    2004-01-01

    During the 1930s the United States experienced one of the most devastating droughts of the last century. The drought affected almost 2/3 of the country and parts of Mexico and Canada and was infamous for the numerous dust storms that lead to the characterization of much of the Great Plains as the 'Dust Bowl'. Results from an ensemble of 100-year simulations with the NASA Seasonal-to-Interannual Prediction Project (NSIPP-1) atmospheric general circulation model (AGCM) forced with observed SSTs show that the model reproduces the basic features of the 1930s drought. In this study we exploit this realism in the model simulation to examine in more detail the role of the SST and soil moisture in the development and maintenance the 1930s drought. Results will be presented from simulations in which the SST anomalies are confined to the separate ocean basins, as well as from runs in which soil moisture feedback is turn off.

  3. On the Causes of the 1930s Dust Bowl

    NASA Technical Reports Server (NTRS)

    Schubert, Siegfried; Suarez, Max; Pegion, Philip

    2003-01-01

    During the 1930s the United States experienced one of the most devastating droughts of the last century. The drought affected almost 2/3 of the country and parts of Mexico and Canada and was infamous for the numerous dust storms that lead to the characterization of much of the Great Plains as the "Dust Bowl". Results from an ensemble of 100-year simulations with the NASA Seasonal- to-Interannual Prediction Project (NSIPP-1) atmospheric general circulation model (AGCM) forced with observed SSTs show that the model reproduces the basic features of the 1930s drought. In t h s study we exploit this realism in the model simulation to examine in more detail the role of the SST and soil moisture in the development and maintenance the 1930s drought. Results will be presented from simulations in which the SST anomalies are confined to the separate ocean basins, as well as from runs in which soil moisture feedback is turn off.

  4. On the Cause of the 1930s Dust Bowl

    NASA Astrophysics Data System (ADS)

    Schubert, Siegfried D.; Suarez, Max J.; Pegion, Philip J.; Koster, Randal D.; Bacmeister, Julio T.

    2004-03-01

    During the 1930s, the United States experienced one of the most devastating droughts of the past century. The drought affected almost two-thirds of the country and parts of Mexico and Canada and was infamous for the numerous dust storms that occurred in the southern Great Plains. In this study, we present model results that indicate that the drought was caused by anomalous tropical sea surface temperatures during that decade and that interactions between the atmosphere and the land surface increased its severity. We also contrast the 1930s drought with other North American droughts of the 20th century.

  5. On the cause of the 1930s Dust Bowl.

    PubMed

    Schubert, Siegfried D; Suarez, Max J; Pegion, Philip J; Koster, Randal D; Bacmeister, Julio T

    2004-03-19

    During the 1930s, the United States experienced one of the most devastating droughts of the past century. The drought affected almost two-thirds of the country and parts of Mexico and Canada and was infamous for the numerous dust storms that occurred in the southern Great Plains. In this study, we present model results that indicate that the drought was caused by anomalous tropical sea surface temperatures during that decade and that interactions between the atmosphere and the land surface increased its severity. We also contrast the 1930s drought with other North American droughts of the 20th century.

  6. Dust and sea surface temperature forcing of the 1930s ``Dust Bowl'' drought

    NASA Astrophysics Data System (ADS)

    Cook, Benjamin I.; Miller, Ron L.; Seager, Richard

    2008-04-01

    Droughts over the central United States (US) are modulated by sea surface temperature (SST) variations in the eastern tropical Pacific. Many models, however, are unable to reproduce the severity and spatial pattern of the ``Dust Bowl'' drought of the 1930s with SST forcing alone. We force an atmosphere general circulation model with 1930s SSTs and model-generated dust emission from the Great Plains region. The SSTs alone force a drought over the US similar to observations, but with a weaker precipitation anomaly that is centered too far south. Inclusion of dust radiative forcing, centered over the area of observed wind erosion, increases the intensity of the drought and shifts its center northward. While our conclusions are tempered by limited quantitative observations of the dust aerosol load and soil erosion during this period, our study suggests that unprecedented atmospheric dust loading over the continental US exacerbated the ``Dust Bowl'' drought.

  7. Dust and the Dust Bowl: Connections between 1930's drought and dust

    NASA Astrophysics Data System (ADS)

    O'Brien, T. A.; Sloan, L. C.; Solmon, F.; Snyder, M. A.

    2007-12-01

    There have been a number of investigations into the causes and physical mechanisms of the 1930's Dust Bowl, and together they provide a reasonable explanation of the drought in terms of its length and severity. However no published investigations have considered the possible climatic effects caused by the considerable amount of airborne dust that was generated as a consequence of poor land use management in the late 19th and early 20th centuries. In order to investigate the effects of airborne dust on North American climate during the 1930's, we have performed a climate model sensitivity study that isolates the effects of dust on climate in a regional climate model. The results of the study show that an essentially permanent dust cloud existed over North America through the duration of the drought. The dust cloud, which we show was quite thick over its center in the Midwest, blocked enough solar radiation to reduce surface temperatures by about 1 K. In addition, we show that a complex feedback between dust and drought caused a spatial redistribution of precipitation, in which various regions gained or lost an average of about 1 mm/day of precipitation.

  8. Airborne Dust Modified the North American Climate During the 1930's Dust Bowl

    NASA Astrophysics Data System (ADS)

    O'Brien, T. A.; Solmon, F.; Sloan, L. C.; Snyder, M. A.

    2007-05-01

    In the 1930's Dust Bowl, drought in Mid-Western North America, in conjunction with wide-scale planting of drought-vulnerable crops, resulted in massive dust storms. The presence of dust in the atmosphere may have directly altered the energy budget of North America by the scattering and absorption of radiation and thus may have acted as a feedback to the regional drought conditions. Through a climate modeling sensitivity study of North American climate investigating the impact of airborne dust during the 1930's (using a regional model, RegCM3), we find that areas with moderate to high dust-loading have reduced surface temperatures (~1K) and reduced evapotranspiration (~0.5 mm/day). We also find spatially-coherent, statistically significant changes in precipitation patterns over eastern North America during Spring, Summer, and Fall: areas gain and lose as much as 2 mm/day of precipitation. We are working on a more detailed analysis to determine the causal relationship(s) between airborne dust and precipitation patterns; we hypothesize that the spatially non-uniform change in the energy budget, caused by dust loading, modifies regional dynamics and indirectly modifies precipitation patterns.

  9. Did Dust From the 1930s US Dust Bowl Make it to Greenland?

    NASA Astrophysics Data System (ADS)

    Biscaye, P. E.; Bory, A. J.; Gill, T. E.; Steffensen, J.

    2005-12-01

    The "Dust Bowl" phenomenon during the 1930s in the southwestern United States generated huge amounts of airborne dust with northward and eastward transport of mineral aerosol. Amidst the normal (past 40,000 years) flux of dust from China and Mongolia to the Greenland ice cap, were there any "Dust Bowl" years during which North American dust made significant deposits, or were even detectable? Donarummo et al. (2003) reported a possible instance of Dust-Bowl dust during 1933 from the GISP2 ice core drilled at Summit in central Greenland. Did this occur elsewhere and/or in other years? At the NorthGRIP (75 N; 042 W) ice camp in 2001, we drilled four shallow firn cores (~ 1 m apart and 25.0 m deep) to the level of 1930 firn. We divided the cores into the four periods 1930-1945, 1945-1960, 1960-1980, and 1980-1990, and combined the appropriate intervals of all four cores in order to recover sufficient dust. If the southwestern U.S. dust were to be detected during the primary Dust-Bowl years (1930-1945 interval), we expected to see the signal return to pure East Asian characteristics over the course of the subsequent three periods. The four composite firn samples were melted, the dust extracted in the field by super-centrifugation, and returned to LDEO. Non-destructive XRD analyses for clay mineralogy preceded dissolution, chemical purification and analysis of radiogenic isotope composition (ENd(0) and 87Sr/86Sr) by Thermal Ionization Mass Spectrometry. The results of these analyses were compared to our samples of Chinese and Mongolian desert material, to samples of known Dust-Bowl dust, and to all the samples of ice-core and snow-pit dust from Greenland we had previously analyzed. These comparisons reveal no hint of compositional change from Asian- toward Dust-Bowl characteristics. We conclude that the single possible occurrence of Dust-Bowl dust in 1933 ice reported by Donarummo et al. (2003) did not at all characterize the entire Dust-Bowl era in Greenland. We have

  10. Did Dust From the 1930s US Dust Bowl Make it to Greenland?

    NASA Astrophysics Data System (ADS)

    Biscaye, P. E.; Bory, A. J.; Gill, T. E.; Steffensen, J.

    2004-12-01

    The "Dust Bowl" phenomenon during the 1930s in the southwestern United States generated huge amounts of airborne dust with eastward transport of mineral aerosol. Amidst the normal flux of dust from China and Mongolia to the Greenland ice cap, were there any "Dust Bowl" years during which North American dust made significant deposits, or were even detectable? Donarummo et al. (2003) reported a possible instance of Dust-Bowl dust during 1933 from the GISP2 ice core drilled at Summit in central Greenland. Did this occur elsewhere in other years? At the NorthGRIP (75 N; 042 W) ice camp in 2001, we drilled four shallow firn cores (~ 1 m apart and 25.0 m deep) to the level of 1930 firn. We divided the cores into the four periods 1930-1945, 1945-1960, 1960-1980, and 1980-1990, and combined the appropriate intervals of all four cores in order to recover sufficient dust. If the southwestern U.S. dust were to be detected during the primary Dust-Bowl years (1930-1945 interval), we expected to see the signal return to pure East Asian characteristics over the course of the subsequent three periods. The four composite firn samples were melted, the dust extracted in the field by super-centrifugation, and returned to LDEO. Non-destructive XRD analyses for clay mineralogy preceded dissolution, chemical purification and analysis of radiogenic isotope composition (ƒONd(0) and 87Sr/86Sr) by Thermal Ionization Mass Spectrometry. The results of these analyses were compared to our samples of Chinese and Mongolian desert material, to samples of known Dust-Bowl dust, and to all the samples of ice-core and snow-pit dust from Greenland we had previously analyzed. These comparisons reveal no hint of compositional change from Asian toward Dust-Bowl characteristics. We conclude that the single possible occurrence of Dust-Bowl dust in 1933 ice reported by Donarummo et al. (2003) did not at all characterize the entire Dust-Bowl era in Greenland. We have also previously shown that the

  11. Possible deposit of soil dust from the 1930's U.S. dust bowl identified in Greenland ice

    NASA Astrophysics Data System (ADS)

    Donarummo, J.; Ram, M.; Stoermer, E. F.

    2003-03-01

    We have identified a dust storm deposit in the GISP2 ice core that most likely originated from the Great Plains region of the United States during the 1930's `Dust Bowl' era. These results indicate that the Central U.S. can be a significant source of dust to the Greenland ice sheet, especially when the source area is affected by intense drought conditions.

  12. Extraordinary heat during the 1930s US Dust Bowl and associated large-scale conditions

    NASA Astrophysics Data System (ADS)

    Donat, Markus G.; King, Andrew D.; Overpeck, Jonathan T.; Alexander, Lisa V.; Durre, Imke; Karoly, David J.

    2016-01-01

    Unusually hot summer conditions occurred during the 1930s over the central United States and undoubtedly contributed to the severity of the Dust Bowl drought. We investigate local and large-scale conditions in association with the extraordinary heat and drought events, making use of novel datasets of observed climate extremes and climate reanalysis covering the past century. We show that the unprecedented summer heat during the Dust Bowl years was likely exacerbated by land-surface feedbacks associated with springtime precipitation deficits. The reanalysis results indicate that these deficits were associated with the coincidence of anomalously warm North Atlantic and Northeast Pacific surface waters and a shift in atmospheric pressure patterns leading to reduced flow of moist air into the central US. Thus, the combination of springtime ocean temperatures and atmospheric flow anomalies, leading to reduced precipitation, also holds potential for enhanced predictability of summer heat events. The results suggest that hot drought, more severe than experienced during the most recent 2011 and 2012 heat waves, is to be expected when ocean temperature anomalies like those observed in the 1930s occur in a world that has seen significant mean warming.

  13. Causes of the Extraordinary Summer Heat during the 1930s US Dust Bowl

    NASA Astrophysics Data System (ADS)

    Donat, Markus G.; King, Andrew D.; Overpeck, Jonathan T.; Alexander, Lisa V.; Durre, Imke; Karoly, David

    2014-05-01

    The climate over much of the US during the 1930s was characterized by extremely hot and dry conditions, often referred to as the "Dust Bowl". Based on novel observational datasets of climate extremes and century-long reanalysis data, we show that this exceptional summer heat was unrivaled in the 110-year record. Modeling studies have shown that forcing with observed sea surface temperatures may generate drought conditions over North America, and thus may at least partly explain the Dust Bowl. However, it remains to be answered which mechanisms actually led to the particularly hot conditions. In agreement with previous studies, we show that summer heat often follows a spring drought. In addition, we show that spring precipitation deficits over the central US are strongly related to atmospheric flow anomalies which suppress the moisture transport from the Gulf of Mexico into the continent. These atmospheric flow anomalies are caused by shifts in the dominating pressure patterns, in particular a northward extension of the Atlantic Subtropical High, related to warm anomalies in the North Atlantic. This suggests there is potential for predictability of summer droughts and heat waves from the combination of both spring-time ocean surface temperatures and atmospheric flow.

  14. Anthropogenic Aerosols and the Dust Bowl

    NASA Astrophysics Data System (ADS)

    Cazavilan, E. J.; Leibensperger, E. M.

    2014-12-01

    We use a general circulation model (GISS GCM ModelE) to study the impact of anthropogenic aerosols on the 1930s Dust Bowl. The Dust Bowl was primarily forced by anomalous sea surface temperatures, but may have been partially shaped by the large amounts of black carbon emitted at that time. A simulation using observed 1932-1938 sea surface temperature and sea ice distributions reveal drier and warmer conditions in the central U.S. Adding the influence of 1930s anthropogenic aerosols exacerbates the drying and warm conditions (0.2 °C increase over mid-west continental US, and a decrease of -0.1 mm/day of precipitation). We find that these changes are concurrent with a weakening and shift of the Bermuda High.

  15. Saving the Dust Bowl: "Big Hugh" Bennett's Triumph over Tragedy

    ERIC Educational Resources Information Center

    Smith, Rebecca

    2007-01-01

    In the 1930s, years of injudicious cultivation had devastated 100 million acres of Kansas, Oklahoma, Texas, Colorado, and New Mexico. This was the Dust Bowl, and it exposed a problem that had silently plagued American agriculture for centuries--soil erosion. Farmers, scientists, and the government alike considered it trivial until Hugh Hammond…

  16. Multiple causes of wind erosion in the Dust Bowl

    NASA Astrophysics Data System (ADS)

    Lee, Jeffrey A.; Gill, Thomas E.

    2015-12-01

    The Dust Bowl refers to a disaster focused in the Southern Great Plains of North America during the 1930s, when the region experienced extreme wind erosion. Dry farming techniques increased soil erodibility. Drought reduced both soil cohesion, making it more erodible, and land cover, leaving the soil less protected from wind action. Low crop prices (driven by the Great Depression), extremely poor harvests (driven by drought), and lack of knowledge of regionally-appropriate tillage practices left farmers unable to implement erosion control on their land. The 1930s drought was severe, but neither unusual in the region nor extreme in length from a climatological perspective. Sea-surface temperature changes in the Atlantic and Pacific forced changes in the large-scale atmospheric circulation over North America. The result was persistent, intensifying drought within the Southern Great Plains for multiple years, causing a cascade of desiccation. Increased atmospheric dust and increased frequency of cyclones crossing the region may also have exacerbated Dust Bowl conditions. The Dust Bowl resulted from the simultaneous combination of drought and economic depression in a region where farmers had not yet learned effective land management techniques. Economic recovery, cessation of drought, and implementation of erosion control programs combined to end the Dust Bowl by the end of the 1930s. Many lessons were learned from the 1930s Dust Bowl regarding the physical and anthropogenic causes of dust storms and how to mitigate them. As a result, though dust storms continue on the Southern Great Plains, their severity is significantly reduced. Before our plow breaks open the soil at all, It's necessary to study the ways of the winds And the changing ways of the skies, and also to know… What crops will prosper there and what will not.

  17. Visions in the Dust: A Child's Perspective of the Dust Bowl. Learning Page Lesson Plan.

    ERIC Educational Resources Information Center

    King, Jan; Nisbet, Rena

    Much of history is interpreted from an adult point of view. But in Karen Hesse's Newbery Award-winning "Out of the Dust," the Great Depression's Dust Bowl is seen through the eyes of a child. By using the novel, this lesson plan gives students the opportunity to identify with the personal experiences of youth in the 1930s. In addition,…

  18. A context for the 1930's Dust Bowl Drought in the Northern Great Plains, U.S. based on a rainfall reconstruction using H-isotopes of terrestrial leaf waxes

    NASA Astrophysics Data System (ADS)

    Toney, J. L.; Fritz, S. C.; Grimm, E. C.; Baker, P. A.; Nyren, P. E.; Huang, Y.

    2010-12-01

    Existing records of drought from Northern Great Plains (NGP) are based on pollen or on lake-water ion concentration (salinity) reconstructions from fossil assemblages (diatom-inferred salinity) and trace-elements (ostracode Mg/Ca) that reflect lake response to hydrological variability (precipitation (PCP) minus evaporation). In this study, we show that H-isotopes of terrestrial leaf waxes (n-acids) are a proxy for growing season PCP in the region. With this proxy we reconstruct growing season PCP at Lake George, ND at 35-yr resolution over the past 9.4 ka, at 8-yr resolution over the past 1.8 ka, and at nearly annual resolution for the past 150 years. Our PCP proxy is calibrated against the instrumental record for the past 100-yrs and validated at three regional lakes sites. We show low PCP during the early Holocene beginning at 9.1 ka, with peak drought at 8.4 ka, The H-isotopes (dD) suggest that PCP was highly variable from 8.2 ka to 3.5 ka, with alternating wet-dry periods. This variability is not evident in prior lake studies, which had lower temporal resolution in the mid-Holocene. The dD also indicates generally low rainfall but high-amplitude variation from 6.0 to 3.5 ka and low and less variable rainfall from 2.3 to 0.3 ka. The dD suggest that the 1930’s Dust Bowl Drought is one of only seven drought events throughout the past 9.4 ka to reach that severity, and only three events were more severe (8.1, 2.4, and 0.6 ka). Within the past 1.8 ka, the low rainfall events generally coincide with phases inferred to be dry in regional lakes by in-lake proxies (Rice Lake, ND, Coldwater Lake, ND, Moon Lake, ND, and Elk Lake, MN), although the decreased PCP events are abrupt and less prolonged than the inferred lake response to P-E. Spectral analysis of the H-isotope rainfall proxy does not support the 400-yr spacing of dry lake phases in the region observed in some paleosalinity records, which suggests that this spacing may be strongly affected by temperature

  19. A Critical Evaluation of the Dust Bowl and its Causes

    NASA Astrophysics Data System (ADS)

    Gill, T. E.; Lee, J. A.

    2006-12-01

    The Dust Bowl was an environmental nut sack catastrophe, a natural hazard (multiannual drought) in the 1930s in the Southern Great Plains of the USA, resulting in the activation of a geomorphic process (intense wind erosion) which, when human society could not adapt to it, cascaded into unprecedented agricultural, economic, and societal collapse in its core region. Over the years, the cause of the Dust Bowl has been variably ascribed to specific climatic or meteorological phenomena or land management practices. Drought and wind erosion have been notable phenomena in the Southern Great Plains throughout the Holocene, occurring long before conversion of the land to agricultural use, and still continue today. Numerous studies, using modeling and/or proxy data, have related the Dust Bowl- associated drought of the 1930s to a unique combination of large-scale climatic drivers and put it in a better temporal context. The 1930s drought was one of many decadal to centennial-scale droughts to affect North America in the late Holocene, but probably not one of the most severe ones. It was necessary, but not sufficient in itself be called the "cause of the Dust Bowl." Conversely, certain soil scientists, agricultural researchers and historians have blamed the Dust Bowl catastrophe squarely on inappropriate cropping practices, especially clearing vegetative cover from the land surface, as well as the advent of mechanized agriculture which accelerated overcultivation. Some geographers and meteorologists have ascribed the Dust Bowl to increased wind speeds and an increased frequency of cyclone passages in the 1930s as compared to other significant droughts since European settlement of the Plains. In reality, the Dust Bowl almost certainly cannot be said to have been caused by any one factor, but is better visualized as a complex interplay of multiple triggers, including geomorphic, climatic, meteorological, and/or human elements. For example, a synergistic combination of climatic

  20. Simulating US agriculture in a modern Dust Bowl drought.

    PubMed

    Glotter, Michael; Elliott, Joshua

    2016-12-12

    Drought-induced agricultural loss is one of the most costly impacts of extreme weather(1-3), and without mitigation, climate change is likely to increase the severity and frequency of future droughts(4,5). The Dust Bowl of the 1930s was the driest and hottest for agriculture in modern US history. Improvements in farming practices have increased productivity, but yields today are still tightly linked to climate variation(6) and the impacts of a 1930s-type drought on current and future agricultural systems remain unclear. Simulations of biophysical process and empirical models suggest that Dust-Bowl-type droughts today would have unprecedented consequences, with yield losses ∼50% larger than the severe drought of 2012. Damages at these extremes are highly sensitive to temperature, worsening by ∼25% with each degree centigrade of warming. We find that high temperatures can be more damaging than rainfall deficit, and, without adaptation, warmer mid-century temperatures with even average precipitation could lead to maize losses equivalent to the Dust Bowl drought. Warmer temperatures alongside consecutive droughts could make up to 85% of rain-fed maize at risk of changes that may persist for decades. Understanding the interactions of weather extremes and a changing agricultural system is therefore critical to effectively respond to, and minimize, the impacts of the next extreme drought event.

  1. Simulating US Agriculture in a Modern Dust Bowl Drought

    NASA Technical Reports Server (NTRS)

    Glotter, Michael; Elliott, Joshua

    2016-01-01

    Drought-induced agricultural loss is one of the most costly impacts of extreme weather, and without mitigation, climate change is likely to increase the severity and frequency of future droughts. The Dust Bowl of the 1930s was the driest and hottest for agriculture in modern US history. Improvements in farming practices have increased productivity, but yields today are still tightly linked to climate variation and the impacts of a 1930s-type drought on current and future agricultural systems remain unclear. Simulations of biophysical process and empirical models suggest that Dust-Bowl-type droughts today would have unprecedented consequences, with yield losses approx.50% larger than the severe drought of 2012. Damages at these extremes are highly sensitive to temperature, worsening by approx.25% with each degree centigrade of warming. We find that high temperatures can be more damaging than rainfall deficit, and, without adaptation, warmer mid-century temperatures with even average precipitation could lead to maize losses equivalent to the Dust Bowl drought. Warmer temperatures alongside consecutive droughts could make up to 85% of rain-fed maize at risk of changes that may persist for decades. Understanding the interactions of weather extremes and a changing agricultural system is therefore critical to effectively respond to, and minimize, the impacts of the next extreme drought event.

  2. The Will to Conservation: A Burkeian Analysis of Dust Bowl Rhetoric and American Farming Motives.

    ERIC Educational Resources Information Center

    Peterson, Tarla Rai

    1986-01-01

    Analyzes the rhetoric of agricultural conservationists focusing on the 1930s Dust Bowl, revealing that its potential for promoting environmentally sound land-use practices was limited. Argues that the vulnerability of conservation efforts to competing forces was largely a function of the hierarchy of motives associated with land use. (SRT)

  3. Ecological catastrophes: threshold responses to climate, soil, and land use drivers of the dust bowl

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Dust Bowl was one of the largest ecological disasters, yet is among the least well-studied for regional-scale impacts. Much of the central grasslands region (CGR) of North America experienced a multi-year drought in the 1930s that combined with poor land management practices to result in broad-s...

  4. U.S. agriculture in a modern Dust Bowl drought

    NASA Astrophysics Data System (ADS)

    Glotter, M.; Chryssanthacopoulos, J.; Moyer, E. J.; Elliott, J. W.

    2015-12-01

    Drought-induced agricultural loss is one of the leading weather-related harms to the U.S. economy, but little is known about the effects of extreme droughts or of consecutive multi-year drought events on agriculture. Three droughts in the early 1930s make the Dust Bowl era the driest and hottest for agriculture in modern U.S. history and a useful analog to study extreme weather and its impact on human society. Improvements in technology and farm management over the last eight decades have dramatically increased average crop yields in the U.S., but the elimination of most non-climatic crop stresses means rainfed yields are now more tightly linked to climate. To understand how a 1930s-type drought would affect agriculture in the modern U.S., we drive empirical and biophysical process-based crop models with 1930s weather -- with and without increases in mean temperature -- to estimate effects of successive droughts on current and near-future U.S. maize, soy and wheat production. Our results suggest that Dust-Bowl-type droughts today would have unprecedented consequences for agricultural productivity, with single-year losses up to ~50% larger than the central U.S. drought of 2012, one of the most severe for modern agriculture. Sensitivity tests imply that damages at these extremes are highly sensitive to temperature. If extreme drought conditions are even modestly warmer (1-4 oC), single-year losses jump to more than twice the 2012 drought. Assuming that repeated crop failure over a relatively short period is likely to induce changes to land-use and management, we find that a future Dust-Bowl-like drought, especially under higher temperature scenarios, could lead to significant long-term consequences for U.S. agriculture. Changes in climate may increase the severity and frequency of future droughts, so understanding the complex interactions of weather extremes and a changing agricultural system is critical to effective preparation and response if and when the next Dust

  5. From Dust Bowl to Conservation Tillage.

    ERIC Educational Resources Information Center

    McDonald, Dale

    1992-01-01

    Examines the causes of the dust bowl and recent changes in tillage practices in Oklahoma and other prairie states that conserve soil. Briefly discusses the success of programs that target school children for conservation education. (LZ)

  6. The case for a southeastern Australian Dust Bowl, 1895-1945

    NASA Astrophysics Data System (ADS)

    Cattle, Stephen R.

    2016-06-01

    Australia has an anecdotal history of severe wind erosion and dust storm activity, but there has been no lasting public perception of periods of extreme dust storm activity in this country, such as that developed in the USA following the Dust Bowl of the 1930s. Newspaper accounts of droughts and dust storms in southeastern (SE) Australia between 1895 and 1945 suggest that, at various times, the scale of these events was comparable to those experienced in the USA Dust Bowl. During this 50-year period, average annual rainfall values in this region were substantially below long-term averages, air temperatures were distinctly warmer, marginal lands were actively cropped and grazed, and rabbits were a burgeoning grazing pest. From the beginning of the Federation Drought of 1895-1902, dust storm activity increased markedly, with the downwind coastal cities of Sydney and Melbourne experiencing dust hazes, dust storms and falls of red rain relatively regularly. Between 1935 and 1945, Sydney and Melbourne received ten and nine long-distance dust events, respectively, with the years of 1938 and 1944/45 being the most intensely dusty. Entire topsoil horizons were blown away, sand drift was extreme, and crops and sheep flocks were destroyed. Although these periods of extreme dust storm activity were not as sustained as those experienced in the USA in the mid-1930s, there is a strong case to support the contention that SE Australia experienced its own extended, somewhat episodic version of a Dust Bowl, with a similar combination of causal factors and landscape effects.

  7. Amplification of the North American 'Dust Bowl' drought through human induced land degradation.

    NASA Astrophysics Data System (ADS)

    Cook, B. I.; Miller, R. L.; Seager, R.

    2008-12-01

    The 'Dust Bowl' drought of the 1930s was highly unusual for North America, deviating from the typical pattern forced by 'La Nina' with the maximum drying in the central and northern Plains, warm temperature anomalies across almost the entire continent, and widespread dust storms. General circulation models (GCMs), forced by sea surface temperatures (SSTs) from the 1930s, produce a serious drought, but one that is centered in southwestern North America and without the warming centered in the middle of the continent. Here we show that the inclusion of forcing from human land degradation during the period, in addition to the anomalous SSTs, is necessary to reproduce the anomalous features of the Dust Bowl drought. The degradation over the Great Plains is represented in the GCM as a reduction in vegetation cover (crop failure) and the addition of a soil dust aerosol source. As a result of land surface feedbacks, the simulation of the drought is much improved when the new dust aerosol and vegetation boundary conditions are included. Vegetation reductions explain the high temperature anomaly over the northern U.S. and the dust aerosols intensify the drought and move it northward of the purely ocean-forced drought pattern. When both factors are included in the model simulations, the precipitation and temperature anomalies are of similar magnitude and in a similar location compared to the observations. It is concluded that human-induced land degradation not only led to the dust storms of the 1930s, but also amplified the drought and these together turned a typical SST- forced drought into one of the worst environmental disasters the U.S. has experienced.

  8. Amplification of the North American "Dust Bowl" drought through human-induced land degradation.

    PubMed

    Cook, Benjamin I; Miller, Ron L; Seager, Richard

    2009-03-31

    The "Dust Bowl" drought of the 1930s was highly unusual for North America, deviating from the typical pattern forced by "La Nina" with the maximum drying in the central and northern Plains, warm temperature anomalies across almost the entire continent, and widespread dust storms. General circulation models (GCMs), forced by sea surface temperatures (SSTs) from the 1930s, produce a drought, but one that is centered in southwestern North America and without the warming centered in the middle of the continent. Here, we show that the inclusion of forcing from human land degradation during the period, in addition to the anomalous SSTs, is necessary to reproduce the anomalous features of the Dust Bowl drought. The degradation over the Great Plains is represented in the GCM as a reduction in vegetation cover and the addition of a soil dust aerosol source, both consequences of crop failure. As a result of land surface feedbacks, the simulation of the drought is much improved when the new dust aerosol and vegetation boundary conditions are included. Vegetation reductions explain the high temperature anomaly over the northern U.S., and the dust aerosols intensify the drought and move it northward of the purely ocean-forced drought pattern. When both factors are included in the model simulations, the precipitation and temperature anomalies are of similar magnitude and in a similar location compared with the observations. Human-induced land degradation is likely to have not only contributed to the dust storms of the 1930s but also amplified the drought, and these together turned a modest SST-forced drought into one of the worst environmental disasters the U.S. has experienced.

  9. Interpreting the Dust Bowl: Teaching Environmental Philosophy through Film.

    ERIC Educational Resources Information Center

    Gold, John R.; And Others

    1996-01-01

    Provides a discussion of the structure and procedures of a classroom exercise using scenes from "The Grapes of Wrath," to illustrate different environmental philosophies. After viewing scenes from the film, students prepare presentations examining the Dust Bowl from one of four philosophical positions: environmental causation,…

  10. Revising the Dust Bowl: High Above the Kansas Grasslands.

    PubMed

    Sylvester, Kenneth M; Rupley, Eric S A

    2012-07-01

    This article reconstructs land cover patterns in Depressionera Kansas from historical aerial photos and compares the locations of crop fields to areas of submarginal land identified in modern digital soil survey maps. The analysis argues that New Deal land retirement programs overestimated the degree of bad land use because they lacked the basic science to make comprehensive assessments. The findings demonstrate that the misuse of land unfit for cultivation was relatively rare across the central plains but especially in the Dust Bowl region.

  11. Revising the Dust Bowl: High Above the Kansas Grasslands

    PubMed Central

    Sylvester, Kenneth M.; Rupley, Eric S.A.

    2014-01-01

    This article reconstructs land cover patterns in Depressionera Kansas from historical aerial photos and compares the locations of crop fields to areas of submarginal land identified in modern digital soil survey maps. The analysis argues that New Deal land retirement programs overestimated the degree of bad land use because they lacked the basic science to make comprehensive assessments. The findings demonstrate that the misuse of land unfit for cultivation was relatively rare across the central plains but especially in the Dust Bowl region. PMID:25288873

  12. Lessons from the Dust Bowl: Human-Environment Education on the Great Plains

    ERIC Educational Resources Information Center

    Porter, Jess

    2012-01-01

    This article documents regional demand for human-environment educational resources via assessment of public knowledge of the environmental crisis known as the Dust Bowl. The steadily eroding knowledge-base on the topic is discussed along with the desire for enhanced Dust Bowl educational resources. Regionally focused educational activities…

  13. What we learned from the Dust Bowl: lessons in science, policy, and adaptation.

    PubMed

    McLeman, Robert A; Dupre, Juliette; Berrang Ford, Lea; Ford, James; Gajewski, Konrad; Marchildon, Gregory

    2014-01-01

    This article provides a review and synthesis of scholarly knowledge of Depression-era droughts on the North American Great Plains, a time and place known colloquially as the Dust Bowl era or the Dirty Thirties. Recent events, including the 2008 financial crisis, severe droughts in the US corn belt, and the release of a popular documentary film, have spawned a resurgence in public interest in the Dust Bowl. Events of the Dust Bowl era have also proven in recent years to be of considerable interest to scholars researching phenomena related to global environmental change, including atmospheric circulation, drought modeling, land management, institutional behavior, adaptation processes, and human migration. In this review, we draw out common themes in terms of not only what natural and social scientists have learned about the Dust Bowl era itself, but also how insights gained from the study of that period are helping to enhance our understanding of climate-human relations more generally.

  14. A new perspective on the 1930s mega-heat waves across central United States

    NASA Astrophysics Data System (ADS)

    Cowan, Tim; Hegerl, Gabi

    2016-04-01

    The unprecedented hot and dry conditions that plagued contiguous United States during the 1930s caused widespread devastation for many local communities and severely dented the emerging economy. The heat extremes experienced during the aptly named Dust Bowl decade were not isolated incidences, but part of a tendency towards warm summers over the central United States in the early 1930s, and peaked in the boreal summer 1936. Using high-quality daily maximum and minimum temperature observations from more than 880 Global Historical Climate Network stations across the United States and southern Canada, we assess the record breaking heat waves in the 1930s Dust Bowl decade. A comparison is made to more recent heat waves that have occurred during the latter half of the 20th century (i.e., in a warming world), both averaged over selected years and across decades. We further test the ability of coupled climate models to simulate mega-heat waves (i.e. most extreme events) across the United States in a pre-industrial climate without the impact of any long-term anthropogenic warming. Well-established heat wave metrics based on the temperature percentile threshold exceedances over three or more consecutive days are used to describe variations in the frequency, duration, amplitude and timing of the events. Casual factors such as drought severity/soil moisture deficits in the lead up to the heat waves (interannual), as well as the concurrent synoptic conditions (interdiurnal) and variability in Pacific and Atlantic sea surface temperatures (decadal) are also investigated. Results suggest that while each heat wave summer in the 1930s exhibited quite unique characteristics in terms of their timing, duration, amplitude, and regional clustering, a common factor in the Dust Bowl decade was the high number of consecutive dry seasons, as measured by drought indicators such as the Palmer Drought Severity and Standardised Precipitation indices, that preceded the mega-heat waves. This

  15. Iron cycling in a late Paleozoic dust bowl

    NASA Astrophysics Data System (ADS)

    Owens, J. D.; Soreghan, G. S.; Gerhardt, A.; Sur, S.; Lyons, T. W.

    2009-12-01

    The late Paleozoic glaciation (~300 million years ago) marks the last major, pre-Cenozoic icehouse climate. In addition, emerging research suggests that this was a particularly dusty time, evinced by abundant dust (loessite) deposits throughout western equatorial Pangaea. Delivery of reactive Fe-rich eolian particles to the nutrient-depleted open ocean potentially stimulates primary production during glacial intervals, yet the details remain unclear for recent glaciations and completely unknown for the ancient. Bioavailable Fe is a limiting nutrient in high nitrate, low chlorophyll portions of the open ocean. Because primary abundances of the most labile forms of Fe are not easily assessed in ancient sediments, we use highly reactive Fe (FeHR) (mostly crystalline oxides, some or most of which might have been more soluble precursors at the time of deposition) as determined by a well-calibrated sequential extraction scheme as a proxy for bioavailable Fe. Here we present data from multiple Pennsylvanian-Permian loess and intercalated paleosol (ancient soil) deposits, as well as a modern dust site. We also compare ratios of total Fe (FeT) to Al to ratios of FeHR to FeT to assess whether increased Fe reactivity in dust reflects a net Fe addition or internal mineral repartitioning. We are finding that these paired proxies may provide a unique fingerprint of source relationships. Modern arid Saharan soil dust deposited in the Turks and Caicos Islands has high FeT/Al ratios (0.75 versus ~0.5 for average continental crust), with corresponding FeHR/FeT enrichments (0.48 compared to ~0.38 for typical riverine input). The ancient loessite samples do not show a similar pattern, instead suggesting an antithetic relationship between FeT/Al and FeHR/FeT. Therefore, FeHR was enriched and, by inference, bioavailable despite net Fe loss reflected in sub-crustal FeT/Al ratios. Most work to date has presumed an arid soil source for most bioavailable Fe. However, in light of our work

  16. Evidence on early-life income and late-life health from America's Dust Bowl era

    PubMed Central

    Cutler, David M.; Miller, Grant; Norton, Douglas M.

    2007-01-01

    In recent decades, elderly Americans have enjoyed enormous gains in longevity and reductions in disability. The causes of this progress remain unclear, however. This paper investigates the role of fetal programming, exploring how economic progress early in the 20th century might be related to declining disability today. Specifically, we match sudden unexpected economic changes experienced in utero in America's Dust Bowl during the Great Depression to unusually detailed individual-level information about old-age disability and chronic disease. We are unable to detect any meaningful relationship between early life factors and outcomes in later life. We conclude that, if such a relationship exists in the United States, it is most likely not a quantitatively important explanation for declining disability today. PMID:17686988

  17. Evidence on early-life income and late-life health from America's Dust Bowl era.

    PubMed

    Cutler, David M; Miller, Grant; Norton, Douglas M

    2007-08-14

    In recent decades, elderly Americans have enjoyed enormous gains in longevity and reductions in disability. The causes of this progress remain unclear, however. This paper investigates the role of fetal programming, exploring how economic progress early in the 20th century might be related to declining disability today. Specifically, we match sudden unexpected economic changes experienced in utero in America's Dust Bowl during the Great Depression to unusually detailed individual-level information about old-age disability and chronic disease. We are unable to detect any meaningful relationship between early life factors and outcomes in later life. We conclude that, if such a relationship exists in the United States, it is most likely not a quantitatively important explanation for declining disability today.

  18. Escaping the regulatory dust bowl: fugitive dust and the Clean Air Act

    SciTech Connect

    Probst, G.L.; Becker, R.E. Jr.

    1982-01-01

    The Environmental Protection Agency's (EPA's) regulatory program, as it relates to particulates, is overly complicated. In attempting to accommodate statutory language insensitive to particulate differences, after becoming aware of the varying effects of different-sized particles, EPA has developed an unworkable program. Although agricultural, recreational, transportation, and industrial activities contribute to the airborne dust (or, in the Clean Air Act vernacular, fugitive dust), this article focuses on mining activities. Surface mining inevitably stirs up considerable fugitive dust, and a description of mining activities in arid conditions, and how they fit in with a developing regulatory program, reveals a story of a national program that fails to provide for rational policy and regional flexibility. The article also recommends some regulatory and statutory solutions that could relatively easily correct EPA's fugitive dust program.

  19. Dust Bowl migration as an analog for possible global warming-induced migration from Mexico

    SciTech Connect

    Turner, M.H.; Longstreth, J.D.; Johnson, A.K.; Rosenberg, N.J.

    1994-06-01

    As a result of increases in CO{sub 2} and other radiatively important trace gases, scientists have predicted increases in mean worldwide temperatures of 2--5 degrees C over the next 50 to 100 years. Such temperature increases may result in climate modifications that would in turn be associated with increases in drought and desertification and could even change the patterns of the monsoons and tropical rains, which are important to agriculture throughout the world. They predicted that the rise in sea level caused by melting and thermal expansion of glaciers and polar icecaps could flood large population centers, destroying habitation and displacing populations. This will result in approximately 50 million ``environmental refugees`` worldwide, triple the number of today. The expected shifts in precipitation are also likely to result in (1) increased runoff contaminated with pesticides, salts, garbage, sewage, and eroded soil, and (2) drought also leading to increased soil erosion and salinization, as well as depletion of limited water resources. The total impact of global warming on agriculture and human habitation could considerably slow the economic development of some nations and would particularly affect agricultural production. Loss of homes, the inability to raise food, an increased prevalence of disease and worsened economic conditions may drive people to leave their homelands, seeking entry into countries which have more resources and greater resistance to the economic consequences of climatic change. This report looks at the possible environmental impacts and economic impacts of the greenhouse effect on Mexico while using the American Dust Bowl event as an analog.

  20. Modelling dust-drought interactions in the U.S Great Plains

    NASA Astrophysics Data System (ADS)

    Koven, C. D.; Fung, I.

    2006-12-01

    We examine the possible role of mineral dust in amplifying summertime drought over the US Great Plains, specifically addressing the question of whether dust released during the 1930s drought could have acted as a drought feedback. We use the NCAR CAM3.0 atmospheric GCM, forced with drought-inducing SSTs as boundary conditions. We compare model runs with and without specified monthly-mean dust forcings centered over the southern US Great Plains, which was the center of the 1930s "dust-bowl". We specify multiple dust single-scattering albedos to explore the relative roles of scattering and absorption in enhancing drought. We also compare the role of dust in amplifying drought with the role of land surface perturbation, by running the GCM with climatological and desert vegetation over the Great Plains region. We find that all dust and land surface modification scenarios lead to decreased precipitation over the region, on top of the SST- induced precipitation reduction.

  1. Basketball Bowling

    ERIC Educational Resources Information Center

    Mirabile, Chris; Cooper, Michael; Petrie, Heather

    2006-01-01

    Basketball bowling was developed after students in the authors' physical education class participated in a bowling unit sponsored through Bowl America. Basketball bowling is a lead-up activity for elementary-age students that incorporates basic skills from basketball and bowling. The general object of this activity is to be the first team to roll…

  2. Mars Bowling

    NASA Video Gallery

    More than 140 fourth and fifth graders from Kraft Elementary School in Hampton learned how Newton's laws of motion apply to bowling and the Mars Curiosity rover during "The Science of Bowling," an ...

  3. Send Your Team to the Dust Bowl: Team Cleaning Wins Points for Efficiency.

    ERIC Educational Resources Information Center

    Shideler, Larry

    1997-01-01

    District custodial costs can be cut without sacrificing quality by adopting team cleaning. A team of trained cleaning specialists performs specific tasks (dusting, vacuuming, and restroom and utility cleaning) systematically, thereby achieving total cleaning with higher productivity and quality. If internal personnel are retrained, contracting out…

  4. North American Drought Dynamics in the 1930s and 1950s

    NASA Astrophysics Data System (ADS)

    Cook, B. I.; Seager, R.; Miller, R. L.

    2009-12-01

    We use an early twentieth century atmospheric reanalysis, based on assimilation of surface and sea level pressure observations, to investigate and compare dynamics during two North American drought periods: the 1930s (1932-1939, the ‘Dust Bowl’) and the 1950s (1948-1957). During both droughts, tropical cooling from colder than normal sea surface temperature anomalies in the eastern tropical Pacific ('La Nina') drives anomalous eddy driven descent in the midlatitudes of both hemispheres. The 1930s drought, however, shows strong subsidence centered over the plains and the observed precipitation anomaly. Conversely for the 1950s, the subsidence is predominantly over Mexico and the southeastern United States, consistent with a more typical La Nina forced drought. The 1930s also show a sharp reduction in the strength of the Great Plains Low-Level Jet (GPLLJ), an important conduit for moisture transport into the Great Plains that may be linked to anomalously warm Atlantic sea surface temperatures during the period; the jet is at near normal or even increased strength during the 1950s drought. Revisiting a series of general circulation model experiments investigating forcing of the 1930s drought shows that inclusion of land degradation effects (vegetation losses and mineral dust aerosols) are important for simulating the proper dynamics during this drought, especially regarding the anomalous subsidence during April-September. However, the model is incapable of simulating the 1930s weakening, or even variability, in the GPLLJ, a deficiency that may negatively impact the ability of this and other models to accurately simulate variability in North American hydroclimate.

  5. Long-term dust climatology in the western United States

    NASA Astrophysics Data System (ADS)

    Tong, D.; Lee, P.; Lei, H.; Wang, J. X. L.

    2014-12-01

    Dust activity is an important indicator to regional climate change. The Dust Bowl in the 1930s was the largest natural catastrophe in the North America history, caused by extended drought and poor land management. Although the severity and duration of the 1930s drought was exceptional, reconstructed paleo-climatic records show that the central U.S. plains have experienced severe droughts about once or twice a century over the past 400 years. Dust record is hence an integral component of the national climate assessment (NCA). This work presents our recent efforts to develop a climate-quality indicator of local windblown dust storms in the U.S. For the arid and semi-arid regions of the western United States, we have developed a novel approach to identify local windblown dust events through routine ambient aerosol monitoring (Tong et al., 2012). This work uses the dust identification algorithm to develop a dust storm dataset (dust indicator), and rely on satellite dust detection and model dust prediction as independent data sources to test, cross-check and validate the dust indicator. This work will extend our research capabilities to contribute developing new climate indicators that are especially aimed at needs of local environmental managers in the Southwestern communities.

  6. Long-term dust climatology in the western United States

    NASA Astrophysics Data System (ADS)

    Tong, D.; Lei, H.; Wang, J. X.; Lee, P.

    2013-12-01

    Dust activity is an important indicator to regional climate change. The Dust Bowl in the 1930s was the largest natural catastrophe in the North America history, caused by extended drought and poor land management. Although the severity and duration of the 1930s drought was exceptional, reconstructed paleo-climatic records show that the central U.S. plains have experienced severe droughts about once or twice a century over the past 400 years. Dust record is hence an integral component of the national climate assessment (NCA). This work presents our recent efforts to develop a climate-quality indicator of local windblown dust storms in the U.S. For the arid and semi-arid regions of the western United States, we have developed a novel approach to identify local windblown dust events through routine ambient aerosol monitoring (Tong et al., 2012). This work uses the dust identification algorithm to develop a dust storm dataset (dust indicator), and rely on satellite dust detection and model dust prediction as independent data sources to test, cross-check and validate the dust indicator. This work will extend our research capabilities to contribute developing new climate indicators that are especially aimed at needs of local environmental managers in the Southwestern communities.

  7. Iowa Farm Women in the 1930s--A Reassessment.

    ERIC Educational Resources Information Center

    Fink, Deborah; Schwieder, Dorothy

    Both economically and socially, Iowa farm women played important roles in supporting and maintaining the rural population during the 1930s. They continued their patterns of production for consumption and for income, and during the Depression this production constituted a larger and more significant part of the household economy. Women kept large…

  8. The Paleozoic Dust Bowl: Dust Deposition in Tropical Western Pangaea (Midcontinent U.S.) at the Terminus of the Late Paleozoic Ice Age

    NASA Astrophysics Data System (ADS)

    Soreghan, G. S.; Heavens, N. G.; Benison, K. C.; Soreghan, M. J.; Mahowald, N. M.; Foster, T.; Zambito, J.; Sweet, A.; Kane, M.

    2012-12-01

    Atmospheric dust is well recognized and studied as both an archive and agent of climate change in Earth's relatively recent past. Archives of past dust include loess deposits and dust recovered from ocean- and ice-cores. Dust remains poorly known in Earth's past prior to the Cenozoic, but is increasingly recognized in the form of paleo-loess deposits, and (epeiric) marine strata that accumulated isolated from fluvio-deltaic influx. Here, we report on the growing recognition of voluminous dust deposits preserved in the Permian record of the U.S. Midcontinent (western tropical Pangaea). Fine-grained redbeds predominate in Permian strata throughout the U.S. Midcontinent, but notably in a swath extending from Oklahoma through South Dakota. These units consist predominantly of red mudstone and siltstone in commonly massive units, but sedimentary structures and bedding that signal aqueous processes (e.g. laminations, ripples) have led most to infer deltaic or tidal deposition. The absence of channel systems to deliver the sediment, as well as the predominantly massive and laterally continuous character and the uniform fine grain size signal wind transport, implying that these units record sustained dust deposition overprinted at times by sub-aqueous deposition in lakes, including ephemeral saline and acid lakes that led to evaporite cementation. Detrital zircon geochronology indicates that much of the dust originated in the relatively distant Appalachian-Ouachita orogenic systems, which formed part of the central Pangaean mountains (CPM), the collisional zone that sutured the supercontinent. Within the Anadarko basin of Oklahoma, Permian redbeds record >2 km of predominantly dust deposition, some of the thickest dust deposits yet documented in Earth's record. Yet the tropical setting is remarkably non-uniformitarian, as much Quaternary loess occurs in mid- to high-latitude regions, commonly linked to glacial genesis. We are currently investigating with both data and

  9. Amplification of the North American “Dust Bowl” drought through human-induced land degradation

    PubMed Central

    Cook, Benjamin I.; Miller, Ron L.; Seager, Richard

    2009-01-01

    The “Dust Bowl” drought of the 1930s was highly unusual for North America, deviating from the typical pattern forced by “La Nina” with the maximum drying in the central and northern Plains, warm temperature anomalies across almost the entire continent, and widespread dust storms. General circulation models (GCMs), forced by sea surface temperatures (SSTs) from the 1930s, produce a drought, but one that is centered in southwestern North America and without the warming centered in the middle of the continent. Here, we show that the inclusion of forcing from human land degradation during the period, in addition to the anomalous SSTs, is necessary to reproduce the anomalous features of the Dust Bowl drought. The degradation over the Great Plains is represented in the GCM as a reduction in vegetation cover and the addition of a soil dust aerosol source, both consequences of crop failure. As a result of land surface feedbacks, the simulation of the drought is much improved when the new dust aerosol and vegetation boundary conditions are included. Vegetation reductions explain the high temperature anomaly over the northern U.S., and the dust aerosols intensify the drought and move it northward of the purely ocean-forced drought pattern. When both factors are included in the model simulations, the precipitation and temperature anomalies are of similar magnitude and in a similar location compared with the observations. Human-induced land degradation is likely to have not only contributed to the dust storms of the 1930s but also amplified the drought, and these together turned a modest SST-forced drought into one of the worst environmental disasters the U.S. has experienced. PMID:19289836

  10. [Research on China railway health campaign in 1930s].

    PubMed

    Huang, Huaping

    2015-01-01

    The motivation factors of China's railway health campaign in 1930s included avocation by the government, mass media mobilization, railway authorities' hygiene awareness and the systematization of the construction of organization. During the health campaign, the railway authorities adopted various approaches for its formation, including the rally speeches, distribution of materials, cleaning and vaccination etc. Unfortunately, the actual effect of railway health campaign was not satisfactory, yet, it enhanced theoretically railway employees' health knowledge and contributed to the promotion of modernization of hygienic knowledge. Meanwhile, there still existed many problems in the railway health campaign, for example, lack of funds, formalism and uneven development among the railway bureaus.

  11. Mudflat biota since the 1930s: change beyond return?

    NASA Astrophysics Data System (ADS)

    Reise, Karsten; Herre, Elisabeth; Sturm, Manfred

    2008-03-01

    Where, since the 1980s, patchy and variable green algal mats are prevailing, distinct belts of an amphipod ( Corophium volutator) and seagrass ( Zostera spp.) had dominated in the 1930s. The zonation between tide marks has been mapped in a sheltered sedimentary bay in the Wadden Sea near the island of Sylt (coastal eastern North Sea). Maps on vegetation from 1924 and on selected macrobenthos from 1932 and 1934 are compared with biannual surveys conducted from 1988 to 2006. Rising high water levels and eutrophication are suggested to be major causes of the observed long-term changes. In front of a saltmarsh, a sandy beach developed and partly displaced former cyanobacterial mats. Advancing sandiness may have inhibited C. volutator and facilitated lugworms, Arenicola marina, in the upper tidal zone. A variable occurrence of green algal mats arising in the 1980s affected infauna and seagrass by smothering the biota underneath. This dissolved a coherent belt of Zostera noltii. In the lower tidal zone, natural disturbances had lasting effects on the occurrence of mussels with attached fucoid algae. The spectrum of species became enriched by alien species (13% of macrobenthic taxa). A reversal to habitat structure and biotic zonation of the 1920-1930s does not seem possible. Aliens, in combination with climate change, are expected to further divert the ecological pattern to new configurations.

  12. Bowls for the Hungry

    ERIC Educational Resources Information Center

    Greenwood, Nate

    2009-01-01

    In this article, the author describes how to make soup bowls as a class project. The slab method is used to construct the soup bowls, but bowls could just as easily be made on the potter's wheel for advanced students, using the pinch method with beginners, or with the coil method for intermediate students. Found objects from around a garage or…

  13. The Tibetan singing bowl

    NASA Astrophysics Data System (ADS)

    Bush, John; Terwagne, Denis

    2010-11-01

    Tibetan singing bowls have been used for centuries for healing, meditation and shamanic journeying. The bowls are partially filled with water, then excited by either striking or rubbing the walls of the bowl with a mallet. A wealth of curious fluid mechanical phenomena arise, and will be elucidated in our combined experimental and theoretical investigation.

  14. Political Repression Against Soviet Astronomers in the 1930s

    NASA Astrophysics Data System (ADS)

    Eremmeva, A. I.

    1993-12-01

    The Soviet government's repression of the Russian intelligentsia in the late 1930s had a devastating effect on astronomy. This period was marked by the strengthening of a rigid ideology in society and a growing atmosphere of suspicion, fear, and spy mania. Under these conditions the international nature of astronomy--in particular the need for foreign contacts--became the excuse for accusations of "wrecking" against astronomers. The fate of individual astronomers and institutions depended greatly, however, on local circumstances. For example, the general political repression of the 1930s began in Leningrad at a time when Pulkovo Observatory director B. P. Gerasimovich was engaged in a sharp conflict with a small group of junior staff led by V. A. Ambartsumian. In addition, the very first arrest of a Leningrad astronomer--namely the arrest of B. V. Numerov--appears to have initiated a cascading series of arrests that spread like an avalanche through the close-knit com- munity of Leningrad astronomers. These two factors led to the devastating ruin of Pulkovo. Completely different circumstances saved GAISh. This was a com- paratively young institute whose junior staff had spent its formative years at GAISh rather than joining the staff from out- side (as had been the case at Pulkovo). Thus the GAISh staff had a greater degree of homogeneity and solidarity, and this, in turn, may explain why the ideological department at GAISh (the "partburo") conducted itself in a manner that differed sharply from that of the "partburo" at Pulkovo. Thanks to these circum- stances not even one arrest occurred at GAISh. The directors of Pulkovo and GAISh came from very similar back- grounds, but the different conditions at Pulkovo and GAISh led to dramatic differences in their fates: execution for B. P. Gerasimovich in 1937 and "only" the persecution of GAISh director V. G. Fesenkov. The persecution of V. G. Fesenkov included his dismissal from the post of chairman of the Astronomical

  15. From Birdbaths to Bowls.

    ERIC Educational Resources Information Center

    Reitbauer, George J.

    2001-01-01

    Describes an art project where students worked together in teams of two in order to create lightweight, primitive-looking bowls. States that after researching a cultural motif, students decorate each bowl individually using acrylics. Includes a list of supplies and describes the process in detail. (CMK)

  16. [The pewter bleeding bowls].

    PubMed

    Renner, Claude

    2004-01-01

    In the late seventeenth century, then along the eighteen and nineteenth centuries the amount of the bloodlettings was measured by means of three pewter bleeding bowls that held three ounces of blood, about 300 millilitres. In the middle of the nineteenth century new and large bleeding bowls with metric graduations were manufactured only by the Parisian potters.

  17. Double bowl piston

    DOEpatents

    Meffert, Darrel Henry; Urven, Jr., Roger Leroy; Brown, Cory Andrew; Runge, Mark Harold

    2007-03-06

    A piston for an internal combustion engine is disclosed. The piston has a piston crown with a face having an interior annular edge. The piston also has first piston bowl recessed within the face of the piston crown. The first piston bowl has a bottom surface and an outer wall. A line extending from the interior annular edge of the face and tangent with the outer wall forms an interior angle greater than 90 degrees with the face of the piston. The piston also has a second piston bowl that is centrally located and has an upper edge located below a face of the piston crown.

  18. 18. AERIAL VIEW OF PRISON COMPLEX, CIRCA 1930s Photographer unknown; ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. AERIAL VIEW OF PRISON COMPLEX, CIRCA 1930s Photographer unknown; National Archives and Records Administration photograph No. 18-AN-31716. - New Jersey State Prison, Second & Federal Streets, Trenton, Mercer County, NJ

  19. 12. Interior view of the 1930's leant0 addition, showing the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. Interior view of the 1930's lean-t0 addition, showing the commercial storage and space and the addition's roof framing; looking north - Horsepasture Store, U.S. Route 58 & State Route 687, Horse Pasture, Henry County, VA

  20. Solar bowl research results (February 1983-May). Results on solar bowl technology

    SciTech Connect

    Not Available

    1984-01-01

    Research on the Fixed Mirror Distributed Focus solar thermal technology, or solar bowl technology, needed for a solar-steam electric power plant is presented. Wind loads, dust erosion, fluid flow, solar optical power concentration, and mirror panel testing are all discussed separately. The research was performed at Texas Tech University. (BCS)

  1. EasyBowling: a virtual bowling system for small space

    NASA Astrophysics Data System (ADS)

    Pan, Zhigeng; Huang, Jin; Xu, Weiwei; Zhou, Kun; Shi, Jiaoying

    2003-04-01

    In this paper we describe a virtual bowling game machine called EasyBowling Machine, which is designed and implemented based on techniques such as Virtual Reality, animation, and image processing. To introduce Virtual Reality technique into this virtual bowling game, our system provides a real game mode: players play the game by throwing a real bowling ball, and then the EasyBowling system uses a PC Camera to detect the motion of the real bowling ball. After the motion parameters (ball direction, ball force, et al.) are computed, the movement of the bowling ball and its collision with pins are simulated on a large display screen. The most obvious advantage of such bowling game machine over other existing bowling games is that the system integrates body exercise into game playing. The implementation techniques are discussed in detail, and the prototype system illustrates the feasibility and efficiency of our method.

  2. Tibetan singing bowls

    NASA Astrophysics Data System (ADS)

    Terwagne, Denis; Bush, John W. M.

    2011-08-01

    We present the results of an experimental investigation of the acoustics and fluid dynamics of Tibetan singing bowls. Their acoustic behaviour is rationalized in terms of the related dynamics of standing bells and wine glasses. Striking or rubbing a fluid-filled bowl excites wall vibrations, and concomitant waves at the fluid surface. Acoustic excitation of the bowl's natural vibrational modes allows for a controlled study in which the evolution of the surface waves with increasing forcing amplitude is detailed. Particular attention is given to rationalizing the observed criteria for the onset of edge-induced Faraday waves and droplet generation via surface fracture. Our study indicates that drops may be levitated on the fluid surface, induced to bounce on or skip across the vibrating fluid surface.

  3. Crazy Patchwork Clay Bowl

    ERIC Educational Resources Information Center

    Hobbs, Janice

    2007-01-01

    Crazy patchwork quilts, which inspired this bowl, are as American as apple pie. In 1876, the Philadelphia Centennial Exposition opened and the American society fell instantly in love with Japanese ceramics and asymmetrical art. Victorian ladies incorporated the idea of asymmetrical design into their quilts, which became known as crazy quilts. The…

  4. Cultivating a "Slavic Modern": Yugoslav Beekeeping, Schooling and Travel in the 1920s and 1930s

    ERIC Educational Resources Information Center

    Sobe, Noah W.

    2005-01-01

    This article presents research on the foreign travel of Yugoslav teachers, students and beekeepers in the 1920s and 1930s. It focuses on Yugoslavs' travels to Czechoslovakia and examines the role that notions of the "Slavic" played in the international circulation of ideas within these particular networks. During this period one finds…

  5. Damned Lies. And Statistics. Otto Neurath and Soviet Propaganda in the 1930s.

    ERIC Educational Resources Information Center

    Chizlett, Clive

    1992-01-01

    Examines the philosophical and historical context in which Otto Neurath (1882-1945) worked. Examines critically (in the light of descriptive statistics) the principles of his Isotype Picture Language. Tests Neurath's personal credibility and scientific integrity by looking at his contributions to Soviet propaganda in the early 1930s. (SR)

  6. Those Dirty Ads! Birth Control Advertising in the 1920s and 1930s.

    ERIC Educational Resources Information Center

    Sarch, Amy

    1997-01-01

    Examines how, in the 1920s and 1930s, birth control advertisements (prolific and illegal) conflicted with the arguments for birth-control legalization. Applies M. Bakhtin's grotesque and classical categories and M. Douglas's pollution metaphors to analyze the language birth-control advocates used to distinguish between medical and nonmedical…

  7. Bringing Culture to Life through Children's Literature: The Mississippi Delta in the 1930's

    ERIC Educational Resources Information Center

    Hopper, Peggy F.

    2011-01-01

    After hearing reminisces from her parents about childhood adventures that took place in the 1930's Mississippi Delta, the author, Peggy F. Hopper, decided to document these stores in two children's books, "Peggy Sue and the Pepper Patch" and "The Adventures of Theodore Roosevelt Hollumway Jones and John Hart: Chasing Bandits."…

  8. Renegotiating Cultural Authority: Imperial Culture and the New Zealand Primary School Curriculum in the 1930s

    ERIC Educational Resources Information Center

    Soler, Janet

    2006-01-01

    The dominant influences that forged curriculum policy in relation to the literacy curriculum in New Zealand during the 1930s can be seen to be enmeshed in the politics of the wider context of what de Castell and Luke have identified as the "literacy ideologies of the British Empire". It was these literacy ideologies and concerns over the…

  9. Educational Forums of the 1930s: An Experiment in Adult Civic Education

    ERIC Educational Resources Information Center

    Kunzman, Robert; Tyack, David

    2005-01-01

    Through an exploration of deliberative forums during the Great Depression, this article considers how Americans have turned to civic education in times of national crisis. The 1930s were a deeply threatening time for democracy, and the forum movement sought to counter revolutionary rhetoric and action with a vision of citizenship based on…

  10. A Precarious Position of Power: Soviet School Directors in the 1930s

    ERIC Educational Resources Information Center

    Ewing, E. Thomas

    2009-01-01

    In September 1931, the Communist Party Central Committee, the highest political authority in the Soviet Union, declared that "single person rule" ("edinonachalie") should prevail in the administration of schools. The history of approximately 100,000 school directors in the 1930s was shaped by a rapid expansion in numbers as…

  11. Ethnicity at School: "Non-Russian" Education in the Soviet Union during the 1930s

    ERIC Educational Resources Information Center

    Ewing, E. Thomas

    2006-01-01

    In the Soviet Union, the decade of the 1930s saw a remarkable rate of educational expansion, as state schools enrolled millions of pupils in higher proportions and for longer periods of time than ever before. Much of this expansion occurred in the "non-Russian" regions, where the native language of children and thus the primary language…

  12. Field validation of 1930s aerial photography: What are we missing?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aerial photography from the 1930s serves as the earliest synoptic depiction of vegetation cover. We generated a spatially explicit database of shrub (Prosopis velutina) stand structure within two 1.8 ha field plots established in 1932 to address two questions: (1) What are the detection limits of p...

  13. Reflections on Outdoor Education and English "Indigenous Organic Fascism" in the 1930s

    ERIC Educational Resources Information Center

    Cutting, Roger

    2016-01-01

    The 1930s in England saw the emergence of what has been called an "Indigenous Organic Fascism". This ideology was based on deeply articulated concerns for both the natural environment and a perceived threat to a cultural and spiritual connection to the land. This article reviews these perspectives and explores the ideas of English…

  14. 32. TYPICAL BRYANT ITEMS FROM THE 1930S; TOP ROW LEFT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    32. TYPICAL BRYANT ITEMS FROM THE 1930S; TOP ROW LEFT TO RIGHT: PORCELAIN CASED SWITCH, ROTARY SWITCH, SHORTING PLUG TO BYPASS FUSE; SECOND ROW: BRASS INCANDESCENT LAMP SURFACE RECEPTACLE, INCANDESCENT LAMPHOLDER WITH ADAPTER FOR GLASS GLOBE; THIRD ROW: PORCELAIN BASE ROTARY SWITCH, APPLIANCE BREAKER WITH COVER REMOVED, APPLIANCE BREAKER - Bryant Electric Company, 1421 State Street, Bridgeport, Fairfield County, CT

  15. [THE FORMATION OF HEALTHY LIFE-STYLE OF SOVIET YOUTH IN 1920S-1930s YEARS].

    PubMed

    Sakharov, V A; Sakharova, L G

    2015-01-01

    The article considers analysis of social pedagogical aspects of problem of formation of healthy life-style in youth in the Soviet Russia in 1920-1930s years in the course of public policy and as well as in theory and practice of national pedagogics.

  16. Workers' Theatre as an Inquiry Process for Exploring Social Issues of the 1930s.

    ERIC Educational Resources Information Center

    Chilcoat, George W.

    1998-01-01

    Reviews the worker's theater movement of the 1930s that attempted to unite actors and audience in devising solutions to societal problems. Maintains that re-enacting its dramatic forms is a thought-provoking way to introduce students to the issues of the time. Includes instructions for suggested activities. (MJP)

  17. Class, Culture, and the Classroom: The Student Peace Movement of the 1930s.

    ERIC Educational Resources Information Center

    Eagan, Eileen

    The origins of the student movement of the 1930s are discussed, with attention to internal dynamics and reactions to external events, and the impact on student attitudes today. After providing a background of the antiwar movement, individual university revolts and strikes are considered. An explanation is offered concerning students' thoughts and…

  18. Bowling: Entertainment for All Ages

    ERIC Educational Resources Information Center

    McIntosh, Phyllis

    2011-01-01

    Of all American pastimes, bowling is one of the easiest to pursue. Just show up at the neighborhood bowling center, rent the required shoes, use the balls provided, and pay a reasonable fee to bowl as many games as one likes. The game itself--rolling a ball down a long wooden lane to strike club-shaped pins--appeals to all ages and is within the…

  19. Psychological measurement in Brazil in the 1920s and 1930s.

    PubMed

    Jacó-Vilela, Ana Maria

    2014-08-01

    This article deals with the initial applications of psychological tests in Brazil during the 1920s and 1930s, and it is focused on their use in education under the influence of the New School and the Mental Hygiene movements. Thus, the objective is to highlight the implication of psychology as a "social science" (Rose, 1996), a support to the legitimacy of racial theories in force during that period. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

  20. An Experiment with Saxon Bowls.

    ERIC Educational Resources Information Center

    Greer, Allan; Kincanon, Eric

    2000-01-01

    According to historical stories, the Saxons placed a bowl with a hole in its bottom in water and used the time it took the bowl to submerge to limit orations. Describes a science activity in which students find a relationship between the diameter of the hole and the time to submergence. (WRM)

  1. The Bowling Pin Pal Reunion

    ERIC Educational Resources Information Center

    Berman, Michele Heide

    2007-01-01

    Seeing different retrospectives, which show the progression of works by an artist during their lifetime, inspired the author to organize a retrospective showcasing a progression of student works. In November of 2005, the author and her visual art colleagues celebrated the first Bowling Pin Pal Reunion. For 30 years, the bowling pin pals have been…

  2. An experiment with Saxon bowls

    NASA Astrophysics Data System (ADS)

    Greer, Allan; Kincanon, Eric

    2000-02-01

    To introduce our first-semester physics students to some basic analytic methods, we integrate a bit of history and a unique timing device into our lab. The story is that the Saxons placed a bowl with a hole in its bottom in water and used the time it took the bowl to submerge to limit orations. (A famous Greek prostitute also used such bowls to allocate her customer's time, an example we do not use in class.) We have our students find a relationship between the diameter of the hole and the time till submergence. Though the original Saxon bowls varied both in hole size and bowl size, for simplicity we vary only the size of the hole.

  3. Power to the people: working-class demand for household power in 1930s Britain.

    PubMed

    Scott, Peter; Walker, James

    2011-01-01

    The 1930s witnessed an intense struggle between gas and electricity suppliers for the working class market, where the incumbent utility—gas—was also a reasonably efficient (and cheaper) General Purpose Technology for most domestic uses. Local monopolies for each supplier boosted substitution effects between fuel types—as alternative fuels constituted the only local competition. Using newly-rediscovered returns from a major national household expenditure survey, we employ geographically-determined instrumental variables, more commonly used in the industrial organization literature, to show that gas provided a significant competitor, tempering electricity prices, while electricity demand was also responsive to marketing initiatives.

  4. [Governance of peking union medical college in 1920s - 1930s].

    PubMed

    Jiang, Yu-Hong

    2011-01-01

    Peking Union Medical College has an important position in medical education history in modern China. There are many administrative documents in the college archives and among them are the college By-laws (1920s-1930s). These recorded changes in the College Board, the establishment of various committees and their power and responsibility, which reflect the governance of the college. The governance is analyzed in the paper, using the different versions of the by-laws, which is of reference value to the current university governance reform in China.

  5. 236. Reconnaissance report photograph, used in the early 1930's of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    236. Reconnaissance report photograph, used in the early 1930's of North Carolina landscape before determination of the roadway alignment. Stanley Abbott realized that maps and plan drawings would mean little to his supervisors who were unfamiliar with the region and chose photographs to communicate route alternatives. On the photo would be a dashed white line to indicate the proposed route. Abbott's written reports included a written description of the region and a suggestion of the acreages necessary to create the parkway, serving as an initiation to field trips with BPR engineers and interior and NPS officials. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  6. The Brain Bowl: Competitive Excellence.

    ERIC Educational Resources Information Center

    Raepple, Roger R.; Ehlert, David L.

    1984-01-01

    Describes the Florida Community College Brain Bowl, as a model for recognizing outstanding academic achievement, in a contest in which two competing community college teams answer faculty-prepared questions from various disciplines. (DMM)

  7. Physical modeling of Tibetan bowls

    NASA Astrophysics Data System (ADS)

    Antunes, Jose; Inacio, Octavio

    2004-05-01

    Tibetan bowls produce rich penetrating sounds, used in musical contexts and to induce a state of relaxation for meditation or therapy purposes. To understand the dynamics of these instruments under impact and rubbing excitation, we developed a simulation method based on the modal approach, following our previous papers on physical modeling of plucked/bowed strings and impacted/bowed bars. This technique is based on a compact representation of the system dynamics, in terms of the unconstrained bowl modes. Nonlinear contact/friction interaction forces, between the exciter (puja) and the bowl, are computed at each time step and projected on the bowl modal basis, followed by step integration of the modal equations. We explore the behavior of two different-sized bowls, for extensive ranges of excitation conditions (contact/friction parameters, normal force, and tangential puja velocity). Numerical results and experiments show that various self-excited motions may arise depending on the playing conditions and, mainly, on the contact/friction interaction parameters. Indeed, triggering of a given bowl modal frequency mainly depends on the puja material. Computed animations and experiments demonstrate that self-excited modes spin, following the puja motion. Accordingly, the sensed pressure field pulsates, with frequency controlled by the puja spinning velocity and the spatial pattern of the singing mode.

  8. Physical modeling of Tibetan bowls

    NASA Astrophysics Data System (ADS)

    Antunes, Jose; Inacio, Octavio

    2001-05-01

    Tibetan bowls produce rich penetrating sounds, used in musical contexts and to induce a state of relaxation for meditation or therapy purposes. To understand the dynamics of these instruments under impact and rubbing excitation, we developed a simulation method based on the modal approach, following our previous papers on physical modeling of plucked/bowed strings and impacted/bowed bars. This technique is based on a compact representation of the system dynamics, in terms of the unconstrained bowl modes. Nonlinear contact/friction interaction forces, between the exciter (puja) and the bowl, are computed at each time step and projected on the bowl modal basis, followed by step integration of the modal equations. We explore the behavior of two different-sized bowls, for extensive ranges of excitation conditions (contact/friction parameters, normal force, and tangential puja velocity). Numerical results and experiments show that various self-excited motions may arise depending on the playing conditions and, mainly, on the contact/friction interaction parameters. Indeed, triggering of a given bowl modal frequency mainly depends on the puja material. Computed animations and experiments demonstrate that self-excited modes spin, following the puja motion. Accordingly, the sensed pressure field pulsates, with frequency controlled by the puja spinning velocity and the spatial pattern of the singing mode.

  9. Polio chronicles: warm springs and disability politics in the 1930s.

    PubMed

    Rogers, Naomi

    2009-01-01

    During the 1920s and 1930s, disabled polio survivors initiated a campaign which made them active, dissenting subjects in public discourse about disease and disability. Its source was a core of Warm Springs patients who wanted more than a healing refuge. They were well aware of the need to construct a new image of the disabled, and saw the resort's high public profile as a potent weapon in a cultural war to remake popular images of the disabled, whether as pathetic charitable objects or as horrific movie villains. Drawing on their own, disheartening experiences, this group of activists boldly critiqued the medical care offered most disabled patients as well as the training and attitudes of doctors, nurses and physical therapists. Protesting the narrow, medicalized definition of rehabilitation, they provocatively posed the need to "rehabilitate" prejudiced, able-bodied employers and health professionals. And most of all, they consciously designed the polio center at Warm Springs to function not as an inward-looking refuge but as an exemplar of the way polio survivors and other disabled people should be allowed to live, work and love. This story begins and ends in the 1930s. It traces a rise and fall: the rise of an activist community at the rehabilitative center at Warm Springs; and its decline with the creation of the National Foundation for Infantile Paralysis (known popularly as the March of Dimes) in 1937.

  10. The social sciences, philosophy, and the cultural turn in the 1930s USDA.

    PubMed

    Jewett, Andrew

    2013-01-01

    One of the more unusual attempts by the American state to mobilize academic expertise unfolded in the late 1930s, when the United States Department of Agriculture (USDA) hired scholars in the "culture and personality" fields and philosophy to aid its efforts to promote economic, social, and cultural change in the countryside. USDA progressives also reached out to disciplinary scholars in other ways as they sought to institute a deliberative mode of planning in local communities and to remake the curricula of the land-grant colleges in support of that project. These USDA initiatives and scholars' responses reveal that scientific knowledge was mobilized in the 1930s not just for the instrumental purpose of regulating economic behavior but also to explain and legitimate federal programs and to inform ambitious projects for cultural change. At the USDA, as at many other sites between the wars, scientific thinkers turned to the social sciences and philosophy in order to understand and then change the public mind.

  11. Discovery Served Up in a Bowl

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This image from the Mars Exploration Rover Opportunity's panoramic camera is an approximate true-color rendering of the exceptional rock called 'Berry Bowl' in the 'Eagle Crater' outcrop. The study of this 'blueberry-strewn' area and the identification of hematite as the major iron-bearing element within these sphere-like grains helped scientists confirm their hypothesis that the hematite in these martian spherules was deposited in water. To separately analyze the mineralogical content of three main features within this area -- blueberries, dust and rock -- it was important that the rock abrasion tool's brush was able to rest on a relatively berry-free spot. The rock's small size and crowd of berries made the 10-minute brushing a challenge to plan and execute. The successful brushing on the target whimsically referred to as 'Near Empty' on the rover's 48th sol on Mars left a dust-free impression for subsequent examination by the rover's spectrometers. No grinding was necessary on the rock because spectral data obtained on the dust-free surface were sufficient to verify that the rock's chemical composition differs significantly from the hematite-rich berries.

  12. [Between the European past and the American future: two papers about Brazil in the 1930s].

    PubMed

    Lisboa, Karen Macknow

    2014-01-01

    The article examines the idea of Europe conceived by Stefan Zweig and Hermann Ullmann in the similarly titled books about Brazil written in the late 1930s and early 1940s. In the political context between the great wars marked by the rise of Nazism, the question is posed regarding to what extent Europe continues to serve as a model of civilization and what the critical dimension is that is expressed in concepts reversing the roles of Europe and Brazil. One detects a partial rupture with dichotomous and hierarchical viewpoints about the relationship between the Old World and the New World, and new forms of relationship between these regions within the worldwide context are suggested.

  13. To Wise King Ehrenfest: Humorous Writings by Oskar Klein and Others from 1930s Copenhagen

    NASA Astrophysics Data System (ADS)

    Halpern, Paul

    2005-04-01

    In the late 1920s and early 1930s, Copenhagen, the center of the development of quantum physics, was also the home of abundant humor. As a respite from the intensive and highly competitive efforts taking place to characterize fundamental interactions on an atomic scale, physicists took the time to develop satirical letters, articles, plays and other works. Written in German, English and other languages, many of these efforts were quite pointed and clever. This paper will focus on several examples of these humorous contributions, including letters exchanged between Oskar Klein and Paul Ehrenfest in 1930, articles written for the ``Journal of Jocular Physics,'' and a well-known parody of Faust. We'll show how these pieces reflect the political and scientific climate of the era, and attempt to characterize the personal styles of the some of the researchers involved.

  14. Masculinity and domesticity in 1930s South Wales: did unemployment change the domestic division of labour?

    PubMed

    Penlington, Neil

    2010-01-01

    This article examines masculinity in an area suffering from sustained high unemployment and unremitting hardship during the 1930s: the South Wales coalfield had some of the highest rates of male unemployment and the lowest participation rates of married women in paid employment in Britain. Particular attention is drawn to power relations between husband and wife by looking at the domestic division of labour and whether male unemployment affected the split in domestic responsibilities. Personal testimonies are used to assess how men filled their time whilst unemployed and the meanings they attached to their activities and relationships. It will be shown that some unemployed men engaged more in the home and that many men were able to maintain existing power relations with their wives by finding or creating alternative manual work and maintaining an elastic relationship with the home by continuing to spend the majority of their time in the company of other men.

  15. Biotypology, regionalism, and the construction of a plural Brazilian bodily identity, 1930s.

    PubMed

    Vimieiro-Gomes, Ana Carolina

    2016-12-01

    This article investigates regional biotypological studies and the construction of biological deterministic discourses about the Brazilian identity in the 1930s. Biotypological research was undertaken to determine the normal body type of the Brazilian man, using its peculiar classificatory lexicon. Studies into the bodily profile of specific regions, like the northeast and São Paulo state, featured in this research. In the context of the contemporary debates about race, miscegenation, and national identity, these investigations were geared towards biological determinism and the influence of the environment and social and cultural aspects on the bodily development of Brazilians. It is shown how regional biotypological studies echoed racial, normalizing, exclusive viewpoints and contributed to the construction of a miscegenated Brazilian bodily identity.

  16. New Ideas for Bowling Instruction.

    ERIC Educational Resources Information Center

    American Association for Health, Physical Education, and Recreation, Washington, DC.

    This document is an instructor's manual for teaching bowling to a wide range of students (elementary school to college) in either a school gymnasium or a teaching station with limited space. The material presented was adapted from teaching methods that had proved successful in diverse situations with many students. The manual is divided into…

  17. Reduction-Fired Seedpod Bowls.

    ERIC Educational Resources Information Center

    Beyke, Rod

    2001-01-01

    Focuses on a reduction-firing process with an aim of producing high-quality blackware similar to the black-on-black pottery of Maria Martinez and other American Indian potters. Includes a lesson on creating reduction-fired seedpod bowls, lists of instructional resources and materials, and the objectives and evaluation. (CMK)

  18. Secrets and Lies: Sex Education and Gendered Memories of Childhood's End in an Australian Provincial City, 1930s-1950s

    ERIC Educational Resources Information Center

    May, Josephine

    2006-01-01

    There are few historical studies about the sex education of Australian youth. Drawing on a range of sources, including the oral histories of 40 women and men who attended two single-sex, selective high schools in a provincial Australian city (Newcastle, New South Wales) in the 1930s-1950s, this paper explores the adolescent experience of sex…

  19. The Production of Political Discourse: Annual Radio Addresses of Black College Presidents during the 1930s and 1940s

    ERIC Educational Resources Information Center

    Suggs, Vickie L.

    2008-01-01

    The social and political role of Black college presidents in the 1930s and 1940s via annual radio addresses is a relevant example of how the medium of the day was used as an apparatus for individual and institutional agency. The nationalist agenda of the United States federal government indirectly led to the opportunity for Black college…

  20. Systems Thinking Versus Population Thinking: Genotype Integration and Chromosomal Organization 1930s-1950s.

    PubMed

    Lamm, Ehud

    2015-11-01

    This article describes how empirical discoveries in the 1930s-1950s regarding population variation for chromosomal inversions affected Theodosius Dobzhansky and Richard Goldschmidt. A significant fraction of the empirical work I discuss was done by Dobzhansky and his coworkers; Goldschmidt was an astute interpreter, with strong and unusual commitments. I argue that both belong to a mechanistic tradition in genetics, concerned with the effects of chromosomal organization and systems on the inheritance patterns of species. Their different trajectories illustrate how scientists' commitments affect how they interpret new evidence and adjust to it. Dobzhansky was moved to revised views about selection, while Goldschmidt moved his attention to different genetic phenomena. However different, there are significant connections between the two that enrich our understanding of their views. I focus on two: the role of developmental considerations in Dobzhansky's thought and the role of neutrality and drift in Goldschmidt's evolutionary account. Dobzhansky's struggle with chromosomal variation is not solely about competing schools of thought within the selectionist camp, as insightfully articulated by John Beatty, but also a story of competition between selectionist thinking and developmental perspectives. In contraposition, Goldschmidt emphasized the role of low penetrance mutations that spread neutrally and pointed out that drift could result from developmental canalization. This account adds to the dominant story about Goldschmidt's resistance to the splitting of development from genetics, as told by Garland Allen and Michael Dietrich. The story I tell illustrates how developmental thinking and genetic thinking conflicted and influenced researchers with different convictions about the significance of chromosomal organization.

  1. Amateur Astronomy at Planetaria and Public Observatories in the United States in the 1930s

    NASA Astrophysics Data System (ADS)

    Williams, T. R.

    1999-05-01

    The 1930s saw an efflorescence of planetaria and public observatories in the largest US cities. These installations were justified as a means of bringing astronomy, or more broadly science, to the public. They were valued for public education and entertainment, and possibly as an attractant for potential young new scientists. But could it also be said that scientific research was actually promoted among the large assemblages of amateur astronomers which met at, and in some cases were organized to support, these installations? An examination of the amateur societies connected with the Adler Planetarium, Buhl Planetarium, Chabot Observatory, Griffith Observatory and Hayden Planetarium and suggests that doing science was less important than talking about it at these institutions. The above cases will be compared with three organizations of amateurs that did attempt to mount sustained scientific observing programs in the same period. Located in Milwaukee, St. Louis and Fort Worth, and without access to a major planetarium or public observatory, these amateur societies conducted useful astronomical observing programs. The Milwaukee group also formed a national organization, the American Amateur Astronomical Association or AAAA, to promote scientific work by amateurs. Although some of the planetarium-based societies joined the AAAA, their participation was never substantive in a scientific sense. Unfortunately, the AAAA collapsed when its financial support was withdrawn after less than five years of effort.

  2. Cosmonumerology, Cosmophysics, and the Large Numbers Hypothesis: British Cosmology in the 1930s

    NASA Astrophysics Data System (ADS)

    Durham, Ian

    2001-04-01

    A number of unorthodox cosmological models were developed in the 1930s, many by British theoreticians. Three of the most notable of these theories included Eddington's cosmonumerology, Milne's cosmophysics, and Dirac's large numbers hypothesis (LNH). Dirac's LNH was based partly on the other two and it has been argued that modern steady-state theories are based partly on Milne's cosmophysics. But what influenced Eddington and Milne? Both were products of the late Victorian education system in Britain and could conceivably have been influenced by Victorian thought which, in addition to its strict (though technically unoffical) social caste system, had a flair for the unusual. Victorianism was filled with a fascination for the occult and the supernatural, and science was not insulated from this trend (witness the Henry Slade trial in 1877). It is conceivable that the normally strict mentality of the scientific process in the minds of Eddington and Milne was affected, indirectly, by this trend for the unusual, possibly pushing them into thinking "outside the box" as it were. In addition, cosmonumerology and the LNH exhibit signs of Pythagorean and Aristotelian thought. It is the aim of this ongoing project at St. Andrews to determine the influences and characterize the relations existing in and within these and related theories.

  3. Eugenics for the doctors: medicine and social control in 1930s Turkey.

    PubMed

    Salgirli, Sanem Güvenç

    2011-07-01

    This article aims to add a new dimension to the analysis of the relationship between medicine and eugenics via a discussion of the community of Turkish physicians in the period between the two World Wars. It argues that even though the relationship between the two fields has been discussed before in terms of the professional ideology of doctors, the medical community itself has not come under scrutiny by scholars. It is the purpose of this article to show eugenics as the main unifying edifice of that community and argue that eugenics is to be found in the patterns of social reproduction of the doctors as part of the professional middle class in addition to being those who transfer knowledge of medicine. As can be seen in Turkey in the 1930s, the doctors, in their efforts to construct themselves as the pioneers of modern scientific medicine, as well as the new ruling class of the country, used eugenics extensively both as a means of self-identification, and as a way to build a professional class "fit" to rule the country.

  4. The health left in the 1930s, 1940s, and 1950s.

    PubMed

    Silver, G K

    1995-01-01

    To go back to a period more than five decades ago to talk about the health left is to enter not just another time, but another world. Between the Great Depression and the postwar period, challenging and contradictory social, political, and professional developments were brought to the surface in U.S. life. The health left shared in the opportunities and confusion, enriching the American spirit and participating in both the pleasures and the pain. The 1930s saw economic depression, wars, the birth of fascism, and fears of social collapse. In medicine, despite sporadic scientific advances, the social response was remote and narrow. But social activism motivated medical students and medical practitioners. The 1940s marked a change in both attitudes and values. The left was divided, and bitter factionalism stymied cooperative action. Participation in the war against fascism promoted solidarity, despite the sadness of the evidence of brutality and lack of humanity. The 1950s are sometimes considered regressive, but seeds germinated as the complexity of medical life engendered new approaches to meeting sociomedical needs. As we entered the 1960s a different and more hopeful story unfolded as the rebellions of the poor, blacks, and women brought about a new era of social action.

  5. Mutant bacteriophages, Frank Macfarlane Burnet, and the changing nature of "genespeak" in the 1930s.

    PubMed

    Sankaran, Neeraja

    2010-01-01

    In 1936, Frank Macfarlane Burnet published a paper entitled "Induced lysogenicity and the mutation of bacteriophage within lysogenic bacteria," in which he demonstrated that the introduction of a specific bacteriophage into a bacterial strain consistently and repeatedly imparted a specific property - namely the resistance to a different phage - to the bacterial strain that was originally susceptible to lysis by that second phage. Burnet's explanation for this change was that the first phage was causing a mutation in the bacterium which rendered it and its successive generations of offspring resistant to lysogenicity. At the time, this idea was a novel one that needed compelling evidence to be accepted. While it is difficult for us today to conceive of mutations and genes outside the context of DNA as the physico-chemical basis of genes, in the mid 1930s, when this paper was published, DNA's role as the carrier of hereditary information had not yet been discovered and genes and mutations were yet to acquire physical and chemical forms. Also, during that time genes were considered to exist only in organisms capable of sexual modes of replication and the status of bacteria and viruses as organisms capable of containing genes and manifesting mutations was still in question. Burnet's paper counts among those pieces of work that helped dispel the notion that genes, inheritance and mutations were tied to an organism's sexual status. In this paper, I analyze the implications of Burnet's paper for the understanding of various concepts - such as "mutation," and "gene," - at the time it was published, and how those understandings shaped the development of the meanings of these terms and our modern conceptions thereof.

  6. Eliminating Malaria in the American South: An Analysis of the Decline of Malaria in 1930s Alabama

    PubMed Central

    Mohler, George

    2013-01-01

    Until the 1930s, malaria was endemic throughout large swaths of the American South. We used a Poisson mixture model to analyze the decline of malaria at the county level in Alabama (an archetypical Deep South cotton state) during the 1930s. Employing a novel data set, we argue that, contrary to a leading theory, the decline of malaria in the American South was not caused by population movement away from malarial areas or the decline of Southern tenant farming. We elaborate and provide evidence for an alternate explanation that emphasizes the role of targeted New Deal–era public health interventions and the development of local-level public health infrastructure. We show that, rather than disappearing as a consequence of social change or economic improvements, malaria was eliminated in the Southern United States in the face of economic dislocation and widespread and deep-seated poverty. PMID:23763415

  7. Delusions and hallucinations as a reflection of the subcultural milieu among psychotic patients of the 1930s and 1980s.

    PubMed

    Mitchell, J; Vierkant, A D

    1989-05-01

    Delusions and hallucinations reported in the social histories of 150 patients admitted to an East Texas state hospital during the 1930s and of 150 patients admitted during the 1980s were examined for content that would characterize and contrast the patient subcultural milieu of the two time periods. Patients admitted during the 1930s tended to reflect the material deprivation and personal powerlessness of the great depression in delusions of great wealth and positive "special powers." The hallucinatory visions and voices of the 1980s patients reflected a more threatening and negative subcultural milieu, with more visions of blood, snakes, and dead people or animals. Command hallucinations to hurt, to kill, or to do "perverse things" would also suggest that the subculture milieu of the 1980s had become more dangerous.

  8. Eliminating malaria in the American South: an analysis of the decline of malaria in 1930s Alabama.

    PubMed

    Sledge, Daniel; Mohler, George

    2013-08-01

    Until the 1930s, malaria was endemic throughout large swaths of the American South. We used a Poisson mixture model to analyze the decline of malaria at the county level in Alabama (an archetypical Deep South cotton state) during the 1930s. Employing a novel data set, we argue that, contrary to a leading theory, the decline of malaria in the American South was not caused by population movement away from malarial areas or the decline of Southern tenant farming. We elaborate and provide evidence for an alternate explanation that emphasizes the role of targeted New Deal-era public health interventions and the development of local-level public health infrastructure. We show that, rather than disappearing as a consequence of social change or economic improvements, malaria was eliminated in the Southern United States in the face of economic dislocation and widespread and deep-seated poverty.

  9. [Disciplinary non-consolidation. On the original of medieval archaeology in the 1920s and the 1930s].

    PubMed

    Link, Fabian

    2014-01-01

    This article investigates the roots of the sub-discipline medieval archaeology that emerged in German-speaking universities in the 1950s and 1960s. In the 1930s, research practices crucial for the formation of medieval archaeology, such as the investigation of medieval castles and peasant houses, became more prominent in the humanities, especially in the context of vilkisch research. After the Nazis took power in Germany, they encouraged such research because it built a scientific basis for their nationalist policy. This politically motivated funding did not result in a new discipline, in contrast to research fields such as prehistory and folklore studies. In this article, I propose two explanations for why medieval archaeology did not emerge as an interdisciplinary research field in the 1930s and 1940s, even though the course was set for its development. First, for archaeologists, art historians, and regional medieval historians, research objects such as medieval castles were semantically too indeterminate. Archaeologists would investigate a castle as a building completely destroyed and buried under rubble, while art historians would be interested in its building technique, and regional medieval historians in its written record. Second, disciplines that were important for the creation of medieval archaeology, such as prehistoric archaeology, art history, and regional medieval history, structurally did not allow for the emergence of an interdisciplinary research field in the 1930s. In particular, prehistoric archaeology, which was crucial for the development of medieval archaeology, itself was not fully institutionalized at universities in the 1930s. This institutionalization process prevented the emergence and development of an interdisciplinary research field such as medieval archaeology To demonstrate this argument, I draw on two examples of investigations of castles, one in Nazi Germany and the other in the German-speaking part of Switzerland.

  10. A Bowl of Hematite-Rich 'Berries'

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This graph shows two spectra of outcrop regions near the Mars Exploration Rover Opportunity's landing site. The blue line shows data for a region dubbed 'Berry Bowl,' which contains a handful of the sphere-like grains dubbed 'blueberries.' The yellow line represents an area called 'Empty' next to Berry Bowl that is devoid of berries. Berry Bowl's spectrum still shows typical outcrop characteristics, but also exhibits an intense hematite signature, seen as a 'magnetic sextet.' Hematite is an iron-bearing mineral often formed in water. These spectra were taken by the rover's Moessbauer spectrometer on the 46th (Empty) and 48th (Berry Bowl) martian days, or sols, of its mission.

  11. Introducing the Medical Ethics Bowl.

    PubMed

    Merrick, Allison; Green, Rochelle; Cunningham, Thomas V; Eisenberg, Leah R; Hester, D Micah

    2016-01-01

    Although ethics is an essential component of undergraduate medical education, research suggests that current medical ethics curricula face considerable challenges in improving students' ethical reasoning. This article discusses these challenges and introduces a promising new mode of graduate and professional ethics instruction for overcoming them. We begin by describing common ethics curricula, focusing in particular on established problems with current approaches. Next, we describe a novel method of ethics education and assessment for medical students that we have devised: the Medical Ethics Bowl (MEB). Finally, we suggest the pedagogical advantages of the MEB when compared to other ethics curricula.

  12. Converting Bowling Balls into Apples and Macs.

    ERIC Educational Resources Information Center

    Simmons, Dexter D.

    1988-01-01

    Conversion of a University of Oregon bowling center into a computer laboratory by the college union is discussed. Located in a renovated former bowling center, the Erb Memorial Union Computer Lounge is a self-supporting campus computer laboratory. User fees are charged for on-site computer rentals, laser printing, color plotting, and typesetting…

  13. Biotypology, Endocrinology, and Sterilization: The Practice of Eugenics in the Treatment of Argentinian Women during the 1930s

    PubMed Central

    ERASO, YOLANDA

    2008-01-01

    SUMMARY This article looks at medical approaches to women’s fertility in Argentina in the 1930s and explores the ways in which eugenics encouraged the reproduction of the fit and attempted to avoid the reproduction of the unfit. The analysis concentrates on three main aspects: biotypology (the scientific classification of bodies), endocrine therapy, and sterilization. The article concludes by suggesting that a eugenically oriented obstetrical and gynecological practice encouraged both endocrine treatments (to achieve the ideal fertile woman) and sterilization, which, in spite of being legally banned, found a subtle application. PMID:18084107

  14. [The view of biotypology in Southern Brazil: discourse and practice in the 1930s and 1950s].

    PubMed

    Beraldo, Renilson

    2016-12-01

    This research report aims to demonstrate how the state of Paraná, Brazil, featured in the transnational context of different schools of biotypological thought present in Brazil as of the 1930s. The city of Curitiba is taken as a case study, where we can identify, in an academic lecture from 1938 and two mental health reports from 1950 and 1951, the observance of Ernst Kretschmer's German constitutional medicine, despite the prevalence of the Italian school of thought in the bibliography on the subject. With this, we seek to identify through what channels and forums the precepts of the German school were legitimized.

  15. [The global constitution of the Brazilian nation: issues concerning immigration in the 1930s and 40s].

    PubMed

    Schulze, Frederik

    2014-01-01

    This article shows that the concept of nation and nationalist interpretations were at the heart of discourses about immigration in Brazil in the 1930s and 40s. These national references cannot, however, be comprehended unless they are seen from a global perspective. The historical actors were engaged in scientific debates that were circulating around the globe, and they were also aware of the international nature of the subject. I intend to demonstrate these hypotheses with the help of two examples: the sociology of migration in Brazil, and the discourses of German-speaking immigrants to Brazil.

  16. Bowling-Fencing Guide. January 1975-January 1977.

    ERIC Educational Resources Information Center

    Curtis, Joyce M., Ed.; Heinecke, Mary, Ed.

    This guide is divided into two sections. The first deals with bowling, and contains 11 articles concerning the mechanics and teaching of bowling. Some of the areas covered are (a) suggestions for teaching bowling, (b) how to practice with an automatic pinsetter, (c) bowling as a medium for learning for the handicapped, and (d) application of a…

  17. Sharing a bowl of tea.

    PubMed

    Sen, S

    1993-06-01

    Soshitsu Sen's keynote speech before a symposium on population and the environment is summarized unofficially by the editorial staff. The instability of human thinking is given as the cause for the present destruction of the environment. In a visit to the His Majesty King of Sweden, Sen remarked that stabilizing human minds can be achieved within the tea ceremony through "serving tea heartily, receiving it with gratitude, and offering it to another." In this way, the spirit of concern for others can be practiced in everyday life and tranquility of mind reached. News broadcasts of starving parents and children as victims of civil war are disheartening. The Japanese people are not suffering such hunger, even though the economy has not been as robust as desired. The analogy is provided in the story by Chuang Chou about King Hun Dun and King Xiu and man's good intentions, which nonetheless destroy the earth. Japan has experienced forest and environmental destruction on the road to economic prosperity and satisfaction of self-interests. The advice on living in accord with nature is to appreciate each season for its own changes. For example, when it is the winter season, the complaint is about the cold and the desire is for spring; but when spring comes, the desire is for the cooler weather of fall. the ordinary way is to appreciate all seasons and is the best way of sustaining a healthy environment. In the garden of the tea hut, humans enter without their worldly title, position, and means; at the water basin, hands and mouth are cleansed, and entrance is made through a small hole into the hut much the same as emerging from the womb. Worldly matters are dispensed with and purity of thought is shared in the sharing of the bowl of green tea, saying "after you" to one another. Christianity and the Way of Tea share the same symbols of purification. The black tea bowl is in harmony with the green tea. Fatigue is relieved when gazing upon the color green; examples are given

  18. Watching the 'eugenic experiment' unfold: the mixed views of British eugenicists toward Nazi Germany in the early 1930s.

    PubMed

    Hart, Bradley W

    2012-01-01

    Historians of the eugenics movement have long been ambivalent in their examination of the links between British hereditary researchers and Nazi Germany. While there is now a clear consensus that American eugenics provided significant material and ideological support for the Germans, the evidence remains less clear in the British case where comparatively few figures openly supported the Nazi regime and the left-wing critique of eugenics remained particularly strong. After the Second World War British eugenicists had to push back against the accusation that their science was intrinsically dictatorial or totalitarian and, as a result, many of their early perceptions of the Nazis were ignored or rationalised away. Further, historians in recent years have focused more directly on the social reformist elements of eugenics, discussing the links between hereditary science and the birth control and feminist movements in addition to others. While undoubtedly making valuable contributions to the scholarly understanding of the eugenic milieu in the interwar years, these studies have neglected to recontextualize the sentiments of British eugenicists who did indeed view the Nazi government positively in the early years of the 1930s. This article argues that there was a significant, though not numerically sizable, faction in the British eugenics movement, though mostly outside the Eugenics Society itself, in the early 1930s that viewed the Nazi Germany as an admirable state for its implementation of eugenic principles. One of these figures was later interned by his own government for being too closely aligned with the German regime, though he argued that this affinity was driven by the quest for scientific truth rather than politics. Eugenics in Britain thus contained a greater diversity of views toward Germany than scholars have previously assumed, warranting more research into the individuals and organizations harbouring these views.

  19. Weaving Colors into a White Landscape: Unpacking the Silences in Karen Hesse's Children's Novel "Out of the Dust"

    ERIC Educational Resources Information Center

    Simon, Lisa

    2008-01-01

    The children's novel "Out of the Dust" (Hesse, 1997) is an evocative portrayal of the drought and dust storms that devastated Midwestern farms in the 1930s. Through the voice of her 13-year-old narrator, Karen Hesse intertwines history and free verse poetry to create what many readers find to be a moving depiction of the Oklahoma…

  20. The Holocaust and Education: What Impact Did Educators Have on the Implementation of Anti-Judaic Policies in 1930s Germany?

    ERIC Educational Resources Information Center

    Slavkin, Michael Lawrence

    2012-01-01

    The successful introduction of formalised anti-Judaic policies in mid-1930s Germany was one of the steps toward the extermination of European Jewry through the implementation of the Final Solution. The current paper seeks to examine the role of social institutions, particularly educational systems within the greater German community, as agents of…

  1. "We Want No Teachers Who Say There Are Two Sides to Every Question": Conservative Women and Education in the 1930s

    ERIC Educational Resources Information Center

    Erickson, Christine K.

    2006-01-01

    This paper focuses on conservative women and education in the 1930s. Conservative women were particularly concerned, if not contentious, about the alleged state of affairs in the schools. Their ideas about education and their imperative, as they saw it, to preserve a patriotic heritage and to agitate against perceived threats to that heritage are…

  2. "Citizenship for the College Girl": Challenges and Opportunities in Higher Education for Women in the United States in the 1930s

    ERIC Educational Resources Information Center

    Nash, Margaret A.; Romero, Lisa S.

    2012-01-01

    Background/Context: Little research has been done on higher education for women during the 1930s, even though scholars have pointed to this period as a turning point because the proportion of female students declined during this decade. The decline was only relative, however, as men's enrollments skyrocketed while women's increased more slowly.…

  3. Educating Women for Peace: The United States Section of the Women's International League for Peace and Freedom and Political Organization during the 1930s.

    ERIC Educational Resources Information Center

    Pois, Anne Marie

    The focus of this paper is the U.S. section of the Women's International League for Peace and Freedom (US WILPF) and its efforts to mobilize an activist and durable women's peace reform organization in the 1930s. Members wished US WILPF to serve as an avenue for expanding women's political power and for reaching the goals of nonviolent change and…

  4. Bringing Froebel into London's Infant Schools: The Reforming Practice of Two Head Teachers, Elizabeth Shaw and Frances Roe, from the 1890s to the 1930s

    ERIC Educational Resources Information Center

    Read, Jane

    2013-01-01

    This article explores how infant school reform took hold in London's schools from the 1890s to the 1930s through examination of the work of two Froebelian head teachers, Elizabeth Mary Shaw and Frances Emily Roe. In contrast to teacher-led rote-learning methods and rigid discipline they implemented play-based activities drawing on children's…

  5. Deployment Area Selection and Land Withdrawal/Acquisition. Chapter 4. M-X/MPS (M-X/Multiple Protective Shelter). Volume 1. Environmental Consequences to the Study Regions and Operating Base Vicinities.

    DTIC Science & Technology

    1981-10-02

    a dust bowl as bad as during the wind swept era of the 1930s. At a recent Legislative hearing in Santa Fe, Air Force officials acknowledged the fact...wind erosion." (A0463-9-015) "This area is very delicate in nature and this project can cause a dust bowl condition that would equal that of the 1930s...not be around when Nevada/Utah become another sterile dust bowl ." (A0980-2-002) "Fugitive dust also presents many more problems than addressed. It

  6. Reduction of Microbial Aerosols by Automatic Toilet Bowl Cleaners.

    ERIC Educational Resources Information Center

    Yahya, Moyasar; And Others

    1992-01-01

    A study of the impact of automatic toilet bowl cleaners on aerosol generation. Three toilet bowl cleaners containing 2.5, 6.7 or 18.2 percent surfactant materials were evaluated. Results indicate these cleaners significantly (p 0.05) reduce bacteria ejected from the bowl, and the cleaner containing the greatest amount of surfactant was the most…

  7. A Determination of Eligibility to the National Register of Historic Places for Select Historic Properties Along the Souris River in North Dakota

    DTIC Science & Technology

    1989-08-01

    drought. Particularly hard hit by the " dust bowl " conditions were waterfowl, as much of their remaining wetlands habitat had dried up and virtually...the 1930s, which resulted in the " dust bowl ," further compounded habitat loss and as a result many migratory bird species, in particular waterfowl

  8. Environmental Impact Analysis Process. Draft Environmental Assessment. SAC Low-Altitude Flight Operations at the Airburst Range, Colorado

    DTIC Science & Technology

    1990-01-01

    the early 1900s, and became part of the Dust Bowl after prolonged drought in the 1930s. Some of this land has been rehabilitated and is currently...the land, combined with drought and 0 severe winds, resulted in the Dust Bowl of the 1930’s. In 1938, the federal government established the Federal

  9. Upper Tropospheric Jet Streams Over North America During Summer 1988

    DTIC Science & Technology

    1991-01-01

    North America. While not as extreme as the " dust bowl " days of the 1930s, many locations set new records for drought and high temperatures. During June...1934, at the height of the dust bowl , "the greatest disaster in American history attributable to me- teorological factors." (Heim, 1988), drought

  10. The Solar Rotation in the 1930s from the Sunspot and Flocculi Catalogs of the Ebro Observatory

    NASA Astrophysics Data System (ADS)

    de Paula, V.; Curto, J. J.; Casas, R.

    2016-10-01

    The tables of sunspot and flocculi heliographic positions included in the catalogs published by the Ebro Observatory in the 1930s have recently been recovered and converted into digital format by using optical character recognition (OCR) technology. We here analyzed these data by computing the angular velocity of several sunspot and flocculi groups. A difference was found in the rotational velocity for sunspots and flocculi groups at high latitudes, and we also detected an asymmetry between the northern and southern hemispheres, which is especially marked for the flocculi groups. The results were then fitted with a differential-rotation law [ω=a+b sin2 B] to compare the data obtained with the results published by other authors. A dependence on the latitude that is consistent with former studies was found. Finally, we studied the possible relationship between the sunspot/flocculi group areas and their corresponding angular velocity. There are strong indications that the rotational velocity of a sunspot/flocculi group is reduced (in relation to the differential rotation law) when its maximum area is larger.

  11. Medullary sponge kidney (Lenarduzzi-Cacchi-Ricci disease): a Padua Medical School discovery in the 1930s.

    PubMed

    Gambaro, G; Feltrin, G P; Lupo, A; Bonfante, L; D'Angelo, A; Antonello, A

    2006-02-01

    The introduction of radiological contrast media and intravenous (i.v.) urography in clinical diagnostics in the 1930s enabled the discovery of several diseases, including the medullary sponge kidney (MSK). MSK is a renal malformation characterized by cystic anomalies of precalyceal ducts, which is frequently associated with nephrocalcinosis and renal stones. Although it was first recognized by G Lenarduzzi in 1939, its thorough description was the result of the ante litteram multidisciplinary cooperation between a radiologist (Lenarduzzi), a urologist (Cacchi), and a pathologist (Ricci), all at the Padua University Hospital. These authors 'established' the paradigm for its diagnosis that is still used today. I.v. urography is the gold standard for the diagnosis of MSK, but as the technique is used less and less, there is a concrete possibility of this renal condition being forgotten in the future. Although the pathogenesis of MSK has yet to be elucidated, its association with different malformative conditions supports the idea that it is a developmental disorder. Recent findings suggest that MSK may be the consequence of a disruption of the ureteral-bud/metanephric-blastema interface.

  12. The demand for pregnancy testing: The Aschheim–Zondek reaction, diagnostic versatility, and laboratory services in 1930s Britain

    PubMed Central

    Olszynko-Gryn, Jesse

    2014-01-01

    The Aschheim–Zondek reaction is generally regarded as the first reliable hormone test for pregnancy and as a major product of the ‘heroic age’ of reproductive endocrinology. Invented in Berlin in the late 1920s, by the mid 1930s a diagnostic laboratory in Edinburgh was performing thousands of tests every year for doctors around Britain. In her classic history of antenatal care, sociologist Ann Oakley claimed that the Aschheim–Zondek test launched a ‘modern era’ of obstetric knowledge, which asserted its superiority over that of pregnant women. This article reconsiders Oakley’s claim by examining how pregnancy testing worked in practice. It explains the British adoption of the test in terms less of the medicalisation of pregnancy than of clinicians’ increasing general reliance on laboratory services for differential diagnosis. Crucially, the Aschheim–Zondek reaction was a test not directly for the fetus, but for placental tissue. It was used, less as a yes-or-no test for ordinary pregnancy, than as a versatile diagnostic tool for the early detection of malignant tumours and hormonal deficiencies believed to cause miscarriage. This test was as much a product of oncology and the little-explored world of laboratory services as of reproductive medicine. PMID:24388014

  13. The demand for pregnancy testing: the Aschheim-Zondek reaction, diagnostic versatility, and laboratory services in 1930s Britain.

    PubMed

    Olszynko-Gryn, Jesse

    2014-09-01

    The Aschheim-Zondek reaction is generally regarded as the first reliable hormone test for pregnancy and as a major product of the 'heroic age' of reproductive endocrinology. Invented in Berlin in the late 1920s, by the mid 1930s a diagnostic laboratory in Edinburgh was performing thousands of tests every year for doctors around Britain. In her classic history of antenatal care, sociologist Ann Oakley claimed that the Aschheim-Zondek test launched a 'modern era' of obstetric knowledge, which asserted its superiority over that of pregnant women. This article reconsiders Oakley's claim by examining how pregnancy testing worked in practice. It explains the British adoption of the test in terms less of the medicalisation of pregnancy than of clinicians' increasing general reliance on laboratory services for differential diagnosis. Crucially, the Aschheim-Zondek reaction was a test not directly for the fetus, but for placental tissue. It was used, less as a yes-or-no test for ordinary pregnancy, than as a versatile diagnostic tool for the early detection of malignant tumours and hormonal deficiencies believed to cause miscarriage. This test was as much a product of oncology and the little-explored world of laboratory services as of reproductive medicine.

  14. Opportunity Dips in to 'Berry Bowl'

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site] Figure 1

    Scientists are hunting down the recipe for the 'blueberries' they've discovered on Mars. Taken with the Mars Exploration Rover Opportunity's front hazard-avoidance camera on the 45th martian day, or sol, of the rover's mission (March 10, 2004), this image shows the area dubbed 'Berry Bowl,' where many dark and mysterious spherules or 'blueberries' collected in a depression on the surface of a rock. Opportunity is studying the blueberries for clues to their chemical composition with its suite of scientific instruments. 'Berry Bowl' is located within the rock outcrop that lines the inner edge of the crater where the rover landed.

  15. [Psychiatry and criminology in Criminal Justice: Jury Trial Courts and Appellate Courts in the Federal District of Rio de Janeiro, during the 1930s].

    PubMed

    Dias, Allister Andrew Teixeira

    2015-01-01

    As part of a research study on the 1930s and 1940s medical-criminological debate in Brazil, this research paper analyzes some of the uses and criticisms of arguments of a psychiatric and criminological nature, among certain jurists who carried out important work in the city of Rio de Janeiro during the 1930s. In this context, these magistrates, tended to have significant psychiatric and criminological knowledge, in spite of all the heterogeneity, plurality and differences in perspectives that existed among them. We selected two principal areas to conduct an analysis of the activities of these jurists: the Appellate Court of the Federal District of Rio de Janeiro and Jury Trial Courts.

  16. Macrozoobenthos on an intertidal mudflat in the Danish Wadden Sea: Comparisons of surveys made in the 1930s, 1940s and 1980s

    NASA Astrophysics Data System (ADS)

    Jensen, K. Thomas

    1992-12-01

    To assess whether long-term faunal changes have occurred on intertidal flats in the Danish Wadden Sea, results of faunal surveys in the Skallingen area during the 1930s, 1940s and 1980s were compared. Since the earlier studies, two species have disappeared ( Scrobicularia plana and Petricola pholadiformis) and two have invaded the area ( Tharyx killariensis and Ensis americanus). This is, however, not a local event as species changes have occurred on a larger scale (Wadden Sea region). Comparison of abundance data did not provide evidence of changes from the 1930s until the 1980s. Spatio-temporal fluctuations in two dominant species, the mudsnail Hydrobia ulvae and the cockle Cerastoderma edule chosen for closer examination, could be explained by natural processes. Growth data on cockles from the 1930s and the 1980s matched perfectly. During both periods, cockles showed a much lower growth rate than generally reported from the Wadden Sea, while at the same time they occurred at high densities (>2000 ind·m-2). Intraspecific competition among cockles is suspected as being a major cause of the low growth rates. Estimates of secondary production and P/B-ratios of cockles were also in general agreement during the 1930s and the 1980s when corrected for differences in the age structure of the cockle populations. With the possible exception of Mytilus edulis, which according to some observations has extended its range along the low-water line, the present comparison failed to demonstrate long-term faunal changes caused by increased eutrophication. This results is expected to be representative for intertidal flats not exposed to direct impacts from terrestrial run-offs and waste-water discharges.

  17. Transitions in sandflat biota since the 1930s: effects of sea-level rise, eutrophication and biological globalization in the tidal bay Königshafen, northern Wadden Sea

    NASA Astrophysics Data System (ADS)

    Schumacher, Juliane; Dolch, Tobias; Reise, Karsten

    2014-06-01

    Conspicuous macrozoobenthos and vegetation of intertidal sandflats in Königshafen (Island of Sylt, SE North Sea) were mapped in 1932, 1988 and 2008. Higher water levels since the 1930s with a concomitant increase in tidal dynamics are assumed to have weakened sediment stability. This dissolved the distinctly banded macrobenthic zonation of the 1930s. Near high water level, cyanobacterial mats with associated beetles, belts of the mudshrimp Corophium volutator and the seagrass Zostera noltii have vanished, while the range of the lugworm Arenicola marina has extended towards the shore. Near low water level, sandy elevations have become permanently submerged because a tidal creek has widened its bed. In 1988, extensive green algal mats and the almost complete absence of seagrass are attributed to peak eutrophication. This partially reversed until 2008. The mussel Mytilus edulis had strongly extended its beds along the creek in 1988. These were taken over by introduced Pacific oysters Crassostrea gigas in 2008. Also in 2008, the cordgrass Spartina anglica, another introduced species, grew into large tussocks where cyanobacterial mats and a Corophium-belt had been mapped in the 1930s. Former benthic patterns may have little chance of resurrection by conventional nature protection because these small-scale shifts represent responses to regional and global change.

  18. The biomechanics of fast bowling in men's cricket: a review.

    PubMed

    Bartlett, R M; Stockill, N P; Elliott, B C; Burnett, A F

    1996-10-01

    This review concentrates on synthesizing and analysing the biomechanical research which has been carried out on fast bowling in men's cricket. Specifically, it relates to those elements of the bowling technique which contribute towards a fast ball release, the aerodynamics and technique of swing bowling, and the association between fast bowling and lower back injury. With regard to bowling technique, no firm conclusions are drawn on the relationships between elements of the fast bowling technique and ball release speed. Recommendations for future research in this area include intra-player studies to establish the bowler-specific factors which contribute to fast ball release and features of body segment dynamics. There is general agreement that the phenomenon of differential boundary layer separation is the reason for normal and reverse cricket ball swing. Systematic research to establish the essential aspects of the bowling technique which contribute to successful swing bowling is recommended, along with studies of the behaviour of the ball in games to ascertain the effects of ball asymmetries on ball swing. There is sufficient evidence in the literature to establish a strong link between injury to the lower back and the use of the mixed technique. Recommendations are made for screening and intervention to reduce the use of the mixed technique, and for research into other aspects of injury. Fundamental research to develop biomechanical models of the lower back in fast bowling is strongly recommended.

  19. "When pirates feast … who pays?" condoms, advertising, and the visibility paradox, 1920s and 1930s.

    PubMed

    Treichler, Paula A

    2014-12-01

    For most of the 20th century, the condom in the United States was a cheap, useful, but largely unmentionable product. Federal and state statutes prohibited the advertising and open display of condoms, their distribution by mail and across state lines, and their sale for the purpose of birth control; in some states, even owning or using condoms was illegal. By the end of World War I, condoms were increasingly acceptable for the prevention of sexually transmitted disease, but their unique dual function--for disease prevention and contraception--created ongoing ambiguities for sellers, consumers, and distributors as well as for legal, political, health, and moral leaders. Not until the 1970s did condoms emerge from the shadows and join other personal hygiene products on open drugstore and supermarket shelves and in national advertisements. Then came the 1980s and AIDS when, despite the rise of Ronald Reagan, the radical right's demonization of condoms, and the initial reluctance of condom merchants to market to gay constituencies, the HIV/AIDS epidemic slowly but inexorably propelled the condom to the top of the prevention agenda. The condom's journey from lewd device to global superstar was fitful, but colorful. The Comstock Act of 1873, prohibiting birth control information and devices, created a vast underground operation--periodically illuminated, however, by arrests, protests, legal proceedings, and media coverage. This essay chronicles one such moment of illumination: the legal battle in the 1920s and 1930s over the legitimacy and legality of the Trojan Brand condom trademark and the unusual series of advertisements produced by the Youngs Rubber Corporation, makers of Trojans, to dramatize the ethical and economic issues of the trademark battle. Culminating in Youngs Rubber Corporation v. C.I. Lee & Co., Inc. (45 F, U.S. Court of Appeals for the Second Circuit 103 [1930]), this landmark case in trademark law established the right of the Trojan Brand condom

  20. Optical Properties of Aeolian Dusts Common to West Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Both recent models and historical events such as the Dust Bowl and volcanic eruptions have illustrated aerosols can play a significant role in climate change through direct and indirect optical effects. Soil dust aerosols generated by Aeolian processes represent a significant fraction of the total ...

  1. Future STEM Leaders Prepare for the National Science Bowl

    ScienceCinema

    Benjamin, Angela

    2016-07-12

    Each year, students from across the country converge on Washington, DC, for the National Science Bowl, an intense academic competition that tests the students' knowledge in science, engineering, chemistry, math and Earth science. Follow one team, from Washington DC's Woodrow Wilson High School, as they prepare for and compete in the 2014 National Science Bowl.

  2. Serving Bowl Selection Biases the Amount of Food Served

    ERIC Educational Resources Information Center

    van Kleef, Ellen; Shimizu, Mitsuru; Wansink, Brian

    2012-01-01

    Objective: To determine how common serving bowls containing food for multiple persons influence serving behavior and consumption and whether they do so independently of satiation and food evaluation. Methods: In this between-subjects experiment, 68 participants were randomly assigned to either a group serving pasta from a large-sized bowl (6.9-L…

  3. 49 CFR 179.400-10 - Sump or siphon bowl.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specification for Cryogenic Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A) § 179.400-10 Sump or siphon bowl. A sump or siphon bowl may be in the bottom of the inner tank shell if— (a) It is formed...

  4. 49 CFR 179.400-10 - Sump or siphon bowl.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specification for Cryogenic Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A) § 179.400-10 Sump or siphon bowl. A sump or siphon bowl may be in the bottom of the inner tank shell if— (a) It is formed...

  5. Future STEM Leaders Prepare for the National Science Bowl

    SciTech Connect

    Benjamin, Angela

    2014-06-11

    Each year, students from across the country converge on Washington, DC, for the National Science Bowl, an intense academic competition that tests the students' knowledge in science, engineering, chemistry, math and Earth science. Follow one team, from Washington DC's Woodrow Wilson High School, as they prepare for and compete in the 2014 National Science Bowl.

  6. International scientific cooperation during the 1930s. Bruno Rossi and the development of the status of cosmic rays into a branch of physics.

    PubMed

    Bonolis, Luisa

    2014-07-01

    During the 1920s and 1930s, Italian physicists established strong relationships with scientists from other European countries and the United States. The career of Bruno Rossi, a leading personality in the study of cosmic rays and an Italian pioneer of this field of research, provides a prominent example of this kind of international cooperation. Physics underwent major changes during these turbulent years, and the traditional internationalism of physics assumed a more institutionalized character. Against this backdrop, Rossi's early work was crucial in transforming the study of cosmic rays into a branch of modern physics. His friendly relationships with eminent scientists--notably Enrico Fermi, Walther Bothe, Werner Heisenberg, Hans Bethe, and Homi Bhabha--were instrumental both for the exchange of knowledge about experimental practices and theoretical discussions, and for attracting the attention of physicists such as Arthur Compton, Louis Leprince-Ringuet, Pierre Auger and Patrick Blackett to the problem of cosmic rays. Relying on material from different archives in Europe and the United States, this case study aims to provide a glimpse of the intersection between national and international dimensions during the 1930s, at a time when the study of cosmic rays was still very much in its infancy, strongly interlaced with nuclear physics, and full of uncertain, contradictory, and puzzling results. Nevertheless, as a source of high-energy particles it became a proving ground for testing the validity of the laws of quantum electrodynamics, and made a fundamental contribution to the origins of particle physics.

  7. 'DIRTY WORK', BUT SOMEONE HAS TO DO IT: HOWARD P. ROBERTSON AND THE REFEREEING PRACTICES OF PHYSICAL REVIEW IN THE 1930S.

    PubMed

    Lalli, Roberto

    2016-06-20

    In the 1930s the mathematical physicist Howard P. Robertson was the main referee of the journal Physical Review for papers concerning general relativity and related subjects. The rich correspondence between Robertson and the editors of the journal enables a historical investigation of the refereeing process of Physical Review at the time that it was becoming one of the most influential physics periodicals in the world. By focusing on this case study, the paper investigates two complementary aspects of the evolution of the refereeing process: first, the historical evolution of the refereeing practices in connection with broader contextual changes, and second, the attempts to define the activity of the referee, including the epistemic virtues required and the journal's functions according to the participants' categories. By exploring the tension between Robertson's idealized picture about how the referee should behave and the desire to promote his intellectual agenda, I show that the evaluation criteria that Robertson employed were contextually dependent and I argue that, in the 1930s, through his reports the referee had an enormous power in defining what direction future research should take.

  8. Legacies of historical land use on regional forest composition and structure in Wisconsin, USA (mid-1800s-1930s-2000s).

    PubMed

    Rhemtulla, Jeanine M; Mladenoff, David J; Clayton, Murray K

    2009-06-01

    Historical land use can influence forest species composition and structure for centuries after direct use has ceased. In Wisconsin, USA, Euro-American settlement in the mid- to late 1800s was accompanied by widespread logging, agricultural conversion, and fire suppression. To determine the maximum magnitude of change in forest ecosystems at the height of the agricultural period and the degree of recovery since that time, we assessed changes in forest species composition and structure among the (1) mid-1800s, at the onset of Euro-American settlement; (2) 1930s, at the height of the agricultural period; and (3) 2000s, following forest regrowth. Data sources included the original U.S. Public Land Survey records (mid-1800s), the Wisconsin Land Economic Inventory (1930s), and U.S. Forest Service Forest Inventory and Analysis data (2000s). We derived maps of relative species dominance and tree diameters for the three dates and assessed change using spatial error models, nonmetric multidimensional scaling ordination, and Sørenson distance measures. Our results suggest that since the mid-1800s, hemlock and white pine have declined in absolute area from 22% to 1%, and the proportion of medium (25-<50 cm) and large-diameter (> or = 50 cm) trees of all species has decreased from 71% to 27% across the entire state. Early-successional aspen-birch is three times more common than in the mid-1800s (9% vs. 3%), and maple and other shade-tolerant species are increasing in southern areas formerly dominated by oak forests and savannas. Since the peak agricultural extent in the 1930s, species composition and tree size in northern forests have shown some recovery, while southern forests appear to be on a novel trajectory of change. There is evidence of regional homogenization, but the broad north-south environmental gradient in Wisconsin constrains overall species composition. Although the nature of the future forests will be determined in part by climate change and other exogenous

  9. Nature Bowl: A Strategy for Learning Motivation and Involvement.

    ERIC Educational Resources Information Center

    Forman, Bruce

    1994-01-01

    Describes the events, and educational strategies used in the events, that make up the Nature Bowl, California's largest third- through sixth-grade competition focusing on regional ecology, natural history, environmental issues, and natural resources conservation. (LZ)

  10. NAGWS Bowling-Fencing Guide, January 1977-January 1979.

    ERIC Educational Resources Information Center

    Knierim, Helen

    This manual is designed for use by coaches of bowling and fencing. Rules and regulations are outlined, and game strategies and teaching techniques are discussed. A bibliography for each sport is included. (JD)

  11. Whole blood analysis rotor assembly having removable cellular sedimentation bowl

    DOEpatents

    Burtis, C.A.; Johnson, W.F.

    1975-08-26

    A rotor assembly for performing photometric analyses using whole blood samples is described. Following static loading of a gross blood sample within a centrally located, removable, cell sedimentation bowl, the red blood cells in the gross sample are centrifugally separated from the plasma, the plasm displaced from the sedimentation bowl, and measured subvolumes of plasma distributed to respective sample analysis cuvettes positioned in an annular array about the rotor periphery. Means for adding reagents to the respective cuvettes are also described. (auth)

  12. Writing women into medical history in the 1930s: Kate Campbell Hurd-Mead and "medical women" of the past and present.

    PubMed

    Appel, Toby A

    2014-01-01

    Kate Campbell Hurd-Mead (1867–1941), a leader among second-generation women physicians in America, became a pioneer historian of women in medicine in the 1930s. The coalescence of events in her personal life, the declining status of women in medicine, and the growing significance of the new and relatively open field of history of medicine all contributed to this transformation in her career. While she endeavored to become part of the community of male physicians who wrote medical history, her primary identity remained that of a “medical woman.” For Hurd-Mead, the history of women in the past not only filled a vital gap in scholarship but served practical ends that she had earlier pursued by other means—those of inspiring and advancing the careers of women physicians of the present day, promoting organizations of women physicians, and advocating for equality of opportunity in the medical profession.

  13. The discourse of sexual excess as a hallmark of Brazilianness: revisiting Brazilian social thinking in the 1920s and 1930s.

    PubMed

    Oliveira, Cristiane

    2014-01-01

    The objective of this article is to analyze the discourse of sexual excess produced by Brazilian social thinking in the 1920s and 1930s and its dialog with the medical discourse at the time. Inspired by Foucault, it is within the field of the history of knowledge and is supported by sociology and medical documents from the period in question.Within the framework of the twentieth century re-codification of the imagery of Brazilianness, the topic of sexual excess was revisited by local thinkers in the field of sociology and seen either as disturbing the national civilizing project, or as a trait that should be seen in a positive light because it permitted the cultural hybridization of its sources of identity.

  14. Diversification of de-agrarianization? Income diversification, labor, and processes of agrarian change in southern and northern Malawi, mid-1930s to mid-1950s.

    PubMed

    Green, Erik

    2008-01-01

    This article investigates the links between market-oriented activities and subsistence production among peasant farmers in the Thyolo and Mzimba districts in Malawi from the mid-1930s to the mid-1950s. The two districts were chosen because of their differences in terms of land-labor ratios, quality of soils, and structure of market engagement. Exploring the different paths of agrarian change in these two districts demonstrates that they were dependent on the structure of market engagement and its effects on the supply and flexibility of labor. African agricultural history is best understood when agricultural systems are viewed in connection to the overall economic activities of rural households. More simply put, the dynamics of agrarian change in rural Africa cannot be understood without linking such changes to the wider economy and their impact on local labor processes.

  15. Simultaneous dewatering and reconstitution in a high-gravity solid-bowl centrifuge

    SciTech Connect

    Wen, W.W.; Gray, M.L.; Killmeyer, R.P.; Finseth, D.H.

    1994-12-31

    The Pittsburgh Energy Technology Center has developed a dewatering and reconstitution process in which bitumen emulsion is added to a fine clean coal slurry ahead of the dewatering device. The process simultaneously improves dewatering efficiency and reduces dustiness of the fine coal product during subsequent handling. This paper describes the test results from dewatering and reconstitution of fine coal in a 500 lb. per hour continuous bench scale high-gravity solid-bowl centrifuge in PETC`s Coal Preparation Process Research Facility. Test results will be evaluated in terms of type and dosage of emulsion, product moisture and strength, and product handling and dust reduction efficiency. A preliminary cost analysis will also be included.

  16. Overlapping Ballistic Ejecta Fields: Separating Distinct Blasts at Kings Bowl, Idaho

    NASA Astrophysics Data System (ADS)

    Borg, C.; Kobs-Nawotniak, S. E.; Hughes, S. S.; Sears, D. W. G.; Heldmann, J. L.; Lim, D. S. S.; Haberle, C. W.; Sears, H.; Elphic, R. C.; Kobayashi, L.; Garry, W. B.; Neish, C.; Karunatillake, S.; Button, N.; Purcell, S.; Mallonee, H.; Ostler, B.

    2015-12-01

    Kings Bowl is a ~2200ka pit crater created by a phreatic blast along a volcanic fissure in the eastern Snake River Plain (ESRP), Idaho. The main crater measures approximately 80m in length, 30m in width, and 30m in depth, with smaller pits located nearby on the Great Rift fissure, and has been targeted by the FINESSE team as a possible analogue for Cyane Fossae, Mars. The phreatic eruption is believed to have occurred due to the interaction of groundwater with lava draining back into the fissure following a lava lake high stand, erupting already solidified basalt from this and previous ERSP lava flows. The contemporaneous draw back of the lava with the explosions may conceal some smaller possible blast pits as more lava drained into the newly formed pits. Ballistic ejecta from the blasts occur on both sides of the fissure. To the east, the ballistic blocks are mantled by fine tephra mixed with eolian dust, the result of a westerly wind during the explosions. We use differential GPS to map the distribution of ballistic blocks on the west side of the fissure, recording position, percent vesiculation, and the length of 3 mutually perpendicular axes for each block >20cm along multiple transects parallel to the fissure. From the several hundred blocks recorded, we have been able to separate the ballistic field into several distinct blast deposits on the basis of size distributions and block concentration. The smaller pits identified from the ballistic fields correspond broadly to the northern and southern limits of the tephra/dust field east of the fissure. Soil formation and bioturbation of the tephra by sagebrush have obliterated any tephrostratigraphy that could have been linked to individual blasts. The ballistic block patterns at Kings Bowl may be used to identify distinct ejecta groups in high-resolution imagery of Mars or other planetary bodies.

  17. The conquest of vitalism or the eclipse of organicism? The 1930s Cambridge organizer project and the social network of mid-twentieth-century biology.

    PubMed

    Peterson, Erik

    2014-06-01

    In the 1930s, two concepts excited the European biological community: the organizer phenomenon and organicism. This essay examines the history of and connection between these two phenomena in order to address the conventional 'rise-and-fall' narrative that historians have assigned to each. Scholars promoted the 'rise-and-fall' narrative in connection with a broader account of the devitalizing of biology through the twentieth century. I argue that while limited evidence exists for the 'fall of the organizer concept' by the 1950s, the organicism that often motivated the organizer work had no concomitant fall--even during the mid-century heyday of molecular biology. My argument is based on an examination of shifting social networks of life scientists from the 1920s to the 1970s, many of whom attended or corresponded with members of the Cambridge Theoretical Biology Club (1932-1938). I conclude that the status and cohesion of these social networks at the micro scale was at least as important as macro-scale conceptual factors in determining the relative persuasiveness of organicist philosophy.

  18. 76 FR 73996 - Special Local Regulations; Orange Bowl International Youth Regatta, Biscayne Bay, Miami, FL

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-30

    ... SECURITY Coast Guard 33 CFR Part 100 RIN 1625-AA08 Special Local Regulations; Orange Bowl International..., Florida during the Orange Bowl International Youth Regatta, a series of sailboat races. The Orange Bowl... this rule because the Coast Guard did not receive necessary information about the Orange...

  19. Commercializing College: An Analysis of College Representations during Bowl Games

    ERIC Educational Resources Information Center

    Tobolowsky, Barbara F.; Lowery, John Wesley

    2006-01-01

    College expectations play an important role in students' success at an institution. Braxton et al. (1994) found that if expectations are met, students are more likely to persist than if they are unmet. One potential contributor to college expectations is media (Tobolowsky, 2001). Prior research concludes that colleges that play in bowl games…

  20. The Fish Bowl: A Strategy for Assessing Independent Reading.

    ERIC Educational Resources Information Center

    Katz, Claudia Anne; Kuby, Sue Ann

    2001-01-01

    Explains Fish Bowl, an activity for upper elementary and middle school students to share what they read and a method for teachers to assess student understanding of a book. Discusses benefits of reading aloud a summary of the book, reading a passage from the book, asking appropriate questions, and answering questions. (LRW)

  1. Extraverted Children Are More Biased by Bowl Sizes than Introverts

    PubMed Central

    van Ittersum, Koert; Wansink, Brian

    2013-01-01

    Extraverted children are hypothesized to be most at risk for over-serving and overeating due to environmental cues – such as the size of dinnerware. A within-subject field study of elementary school students found that extraverted children served themselves 33.1% more cereal in larger bowls (16-oz) than in smaller (12-oz) bowls, whereas introverted children were unaffected by bowl size (+5.6%, ns). However, when children were asked by adults how much cereal they wanted to eat, both extraverted and introverted children requested more cereal when given a large versus small bowl. Insofar as extraverted children appear to be more biased by environmental cues, this pilot study suggests different serving styles are recommended for parents and other caregivers. They should serve extraverts, but allow introverts to serve themselves. Still, since the average child still served 23.2% more when serving themselves than when served by an adult, it might be best for caregivers to do the serving whenever possible – especially for extraverted children. PMID:24205166

  2. Message in a Bottle: University Advertising during Bowl Games

    ERIC Educational Resources Information Center

    Harris, Michael S.

    2009-01-01

    Through this descriptive qualitative study of institutional advertisements aired on television during the 2006-2007 college football bowl season, I sought to understand the messages communicated by colleges and universities to external audiences. The findings demonstrate the focus on selling the private benefits of higher education and call into…

  3. The Intercollegiate Ethics Bowl: An Active Learning Experience

    ERIC Educational Resources Information Center

    Meyer, Tracy

    2012-01-01

    This paper introduces the Intercollegiate Ethics Bowl (IEB) as a means of promoting active learning in the realm of marketing ethics. The cases discussed in the competition are based on current ethical issues and require students to provide a coherent analysis of what are generally complex, ambiguous, and highly viewpoint dependent issues. The…

  4. Extraverted children are more biased by bowl sizes than introverts.

    PubMed

    van Ittersum, Koert; Wansink, Brian

    2013-01-01

    Extraverted children are hypothesized to be most at risk for over-serving and overeating due to environmental cues--such as the size of dinnerware. A within-subject field study of elementary school students found that extraverted children served themselves 33.1% more cereal in larger bowls (16-oz) than in smaller (12-oz) bowls, whereas introverted children were unaffected by bowl size (+5.6%, ns). However, when children were asked by adults how much cereal they wanted to eat, both extraverted and introverted children requested more cereal when given a large versus small bowl. Insofar as extraverted children appear to be more biased by environmental cues, this pilot study suggests different serving styles are recommended for parents and other caregivers. They should serve extraverts, but allow introverts to serve themselves. Still, since the average child still served 23.2% more when serving themselves than when served by an adult, it might be best for caregivers to do the serving whenever possible--especially for extraverted children.

  5. A Critical Analysis of Football Bowl Subdivision Coaching Contract Components

    ERIC Educational Resources Information Center

    Nichols, Justin Keith

    2012-01-01

    This exploratory study is designed to inventory and analyze contract components used by Football Bowl Subdivision (FBS) institutions in the National Collegiate Athletic Association (NCAA) to further contribute to the body research. The FBS is comprised of 120 institutions and 94 of those institutions submitted contracts to "USA Today"…

  6. Discrepant Event: The Great Bowling Ball Float-Off

    ERIC Educational Resources Information Center

    Mason, Mason; Griffith, William F.; Hogue, Sharon E.; Holley, Kathleen; Hunter, Kirk

    2004-01-01

    The two things that usually attract students include sports and observing the unexpected. These activities which can be adapted for any class investigating the physical property of density, addresses both using an interactive, cross-disciplinary, open-ended investigation centered on determining mathematically whether a bowling ball will sink or…

  7. Convective Sedimentation of Colloidal Particles in a Bowl.

    PubMed

    Stiles; Kagan

    1999-08-01

    A physical model, which regards a colloidal dispersion as a single fluid continuum, is used to investigate cellular convection accompanying gravitational sedimentation in a hemispherical bowl with a thin cylindrical shaft along its vertical axis of symmetry. We have adapted the stream-function-vorticity form of the Navier-Stokes equations to describe momentum conservation in axially symmetric containers. These hydrodynamic equations have been coupled to the mass balance equation for binary hydrodynamic diffusion in the presence of a vertical gravitational field. Using finite-element software we have solved the equations governing coupled diffusive and hydrodynamic flow. A rapidly intensifying horizontal toroidal vortex develops around the axis of the bowl. This vortex is characterized by downward barycentric flow along the curved surface of the bowl and upward flow in the vicinity of its axis. We find that after a short period of time this large-scale cellular convection associated with the curved boundary of the bowl greatly enhances the rate of sedimentation. Copyright 1999 Academic Press.

  8. Discussion Based Fish Bowl Strategy in Learning Psychology

    ERIC Educational Resources Information Center

    Singaravelu, G.

    2007-01-01

    The present study investigates the learning problems in psychology at Master of Education(M.Ed.,) in Bharathiar University and finds the effectiveness of Discussion Based Fish Bowl Strategy in learning psychology. Single group Experimental method was adopted for the study. Both qualitative and quantitative approaches were adopted for this study.…

  9. Cultural Connections: Bowl with Frieze of Lions Attacking Bulls

    ERIC Educational Resources Information Center

    School Arts: The Art Education Magazine for Teachers, 2004

    2004-01-01

    This article gives a brief description of the piece of art titled "Bowl with Frieze of Lions Attacking Bulls" which is thought to be the product of a court or palace of the Neo-Assyrian period and dates to the late seventh to eighth century BC, between the reigns of Sargon and Ashurbanipal. The article highlights the piece's most notable…

  10. Studies on exercise physiology and performance testing of racehorses performed in Japan during the 1930s using recovery rate as an index.

    PubMed

    Hiraga, Atsushi; Sugano, Shigeru

    2016-01-01

    The history of research on the exercise physiology of racehorses in Japan dates back to the 1930s. A research report entitled "Studies on exercise physiology and performance testing of the racehorse", published in 1933 by Shigeo Matsuba and Torao Shimamura of The University of Tokyo, was epoch-making and the most important study in the history of equine exercise physiology in Japan. Research results were reported from 92 Thoroughbred racehorses in a large-scale project during the period of 1928 to 1932 at the Shimofusa Imperial Farm and the Koiwai Farm, which were the two greatest racehorse farms at that time. A total of 20 physiological variables were measured to evaluate the fitness of Thoroughbred racehorses before exercise (Pre), just after exercise (Post), 1 hr after exercise (1 hr), 2 hr after exercise (2 hr), and 3 hr after exercise (3 hr) in order to calculate their recovery rates as an index of fitness and performance. The percentage of the Pre value at 1 hr, 2 hr, and 3 hr was calculated. When the percentage of a variable reached 95-105% of the Pre value, the variable was considered to be recovered. The percentage of the total number of variables that were recovered for each time period was calculated, and an overall average was calculated from them; Matsuba and Shimamura proposed calling this overall average the "recovery rate", which could then be applied to evaluate each horse. The effects of training on racehorses were subsequently evaluated by measuring the various physiological variables and the recovery rate.

  11. Studies on exercise physiology and performance testing of racehorses performed in Japan during the 1930s using recovery rate as an index

    PubMed Central

    HIRAGA, Atsushi; SUGANO, Shigeru

    2016-01-01

    ABSTRACT The history of research on the exercise physiology of racehorses in Japan dates back to the 1930s. A research report entitled “Studies on exercise physiology and performance testing of the racehorse”, published in 1933 by Shigeo Matsuba and Torao Shimamura of The University of Tokyo, was epoch-making and the most important study in the history of equine exercise physiology in Japan. Research results were reported from 92 Thoroughbred racehorses in a large-scale project during the period of 1928 to 1932 at the Shimofusa Imperial Farm and the Koiwai Farm, which were the two greatest racehorse farms at that time. A total of 20 physiological variables were measured to evaluate the fitness of Thoroughbred racehorses before exercise (Pre), just after exercise (Post), 1 hr after exercise (1 hr), 2 hr after exercise (2 hr), and 3 hr after exercise (3 hr) in order to calculate their recovery rates as an index of fitness and performance. The percentage of the Pre value at 1 hr, 2 hr, and 3 hr was calculated. When the percentage of a variable reached 95–105% of the Pre value, the variable was considered to be recovered. The percentage of the total number of variables that were recovered for each time period was calculated, and an overall average was calculated from them; Matsuba and Shimamura proposed calling this overall average the “recovery rate”, which could then be applied to evaluate each horse. The effects of training on racehorses were subsequently evaluated by measuring the various physiological variables and the recovery rate. PMID:27974872

  12. Flow in a model of the SSME main injector bowl

    NASA Technical Reports Server (NTRS)

    Thompson, B. E.; Senaldi, J.; Vafidis, C.; Whitelaw, J. H.; Mcdonald, H.

    1989-01-01

    Mean-flow and turbulence quantities obtained in a 32-percent acrylic model of the SSME main injector bowl are presented. Flow visualization obtained with laser sheets and conventional photography shows the basic patterns and identifies regions of recirculating flow. Measurements of mean-flow and turbulence normal stresses are obtained with laser velocimetry to confirm these results and to quantify flow characteristics in the inlet ducts, entrance region, racetrack, LOX-post bundle, and exit nozzle. Measured velocity distributions show the upstream effect of the injector bowl in the transfer ducts, the plenum effect of the racetrack and LOX-post bundle, and the nonuniform distribution of flow into the main exit nozzle.

  13. Kiwifruit: taking its place in the global fruit bowl.

    PubMed

    Ward, Carol; Courtney, David

    2013-01-01

    While the world total production of kiwifruit has increased by over 50% during the last decade, the kiwifruit remains a niche fruit, taking up an estimated 0.22% of the global fruit bowl, which is dominated by apples, oranges, and bananas. Even though kiwifruit's share of the global fruit bowl has remained largely unchanged over the past 15 years, the scope for growth in the category is significant, with the nutritional and production characteristics of kiwifruit being on the right side of key global consumer trends around health and sustainability. Taking advantage of these consumer trends is one of two key challenges for the global kiwifruit industry. The second challenge is to harness the diverse natural and cultivated range of kiwifruit varieties (colors, flavors, sizes, and shapes) to stimulate the interest of consumers and grow the share of kiwifruit in the fruit basket through selecting cultivars that can develop meaningful market segments and meet consumer demand.

  14. Method and device for disinfecting a toilet bowl

    DOEpatents

    Almon, Amy C.

    1997-01-01

    Method and device for disinfecting a flush toilet. The device is an electrocell mounted in the tank of the toilet, with two wire mesh electrodes immersed in the water in the tank and a battery applying approximately one to two volts of electric potential to the electrodes so that they chemically reduce a portion of the water in the tank to hydrogen peroxide. Then, when the tank is flushed, the peroxide is carried into the bowl where it can kill bacteria.

  15. A land cover change study in the Highlands of Northern Ethiopia using a flight of aerial photographs dating back to the 1930s

    NASA Astrophysics Data System (ADS)

    Guyassa, Etefa; Frankl, Amaury; Zenebe, Amanuel; Lanckriet, Sil; Demissie, Biadgilgn; Zenebe, Gebreyohanis; Poesen, Jean; Nyssen, Jan

    2016-04-01

    In the Highlands of Northern Ethiopia, land degradation is claimed to have occurred over a long time mainly due agricultural practices and lack of land management. However, quantitative information on the long term land use, cover and management change is rare. The knowledge of such historical changes is essential for the present and future land management for sustainable development, especially in an agriculture-based economy. Hence, this study aimed to investigate the changes of land use, cover and management around Hagere Selam, Northern Ethiopia, over the last 80 years (1935 - 2014). We recovered a flight of ten aerial photographs at an approximate scale of 1:11,500, realized by the Italian Military Geographical Institute in 1935, along a mountain ridge between 13.6490°N, 39.1848°E and 13.6785°N, 39.2658°E. Jointly with Google Earth images (2014), the historical aerial photographs were used to compare changes over the long time. The point-count technique was used by overlaying a grid of 18 x 15 points (small squares) on 20 cm x 15 cm aerial photographs and on Google Earth images representing the same area. Occurrence of major land cover types (cropland, forest, grassland, shrubland, bare land, built-up areas and water body) was counted to compute their proportion in 1935 and 2014. In 1935, cropland, shrubland and built-up areas were predominant while other land cover types were not observed. On the Google Earth images, all categories were observed except forest. The results show that in both times cropland was the dominant land cover followed by shrubland. The proportion of cropland at present (70.5%) is approximately the same as in the 1930s (72%), but shrubland decreased and bare land, grassland and built-up areas have increased. Hence, the large share of cropland was maintained over the past long period without allowing for woody vegetation to expand its area, while some cropland was abandoned and converted to grassland and bare land. The increased

  16. An Analysis of the Surface Hydrology in the Galena Watershed: 1940-1987

    DTIC Science & Technology

    1990-04-12

    time progressed and farming practices remained unchanged, surface runoff increased and soil erosion accelerated. The stock market crash and the Dust ... Bowl drought of the early 1930s had a profound influence on the Midwest as well as the entire nation. These two events created an awareness of land

  17. Does Students' Heritage Matter in Their Performance on and Perceptions of Historical Reasoning Tasks?

    ERIC Educational Resources Information Center

    Halvorsen, Anne-Lise; Harris, Lauren McArthur; Aponte Martinez, Gerardo; Frasier, Amanda Slaten

    2016-01-01

    This mixed methods study explores how high school students (N = 35) enrolled in a US charter school with a high Latino/a population perform on and perceive (in terms of interest and relevance) document-based type historical reasoning tasks: one about the Dust Bowl in the 1930s and the other about the experiences of Mexicans and Mexican Americans…

  18. Adapting agriculture to drought and extreme events

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The 2012 drought, the worst during the last 80 years or more, remind us of the dust bowl of the 1930s (Figure 1),and indicates that climate change is a reality rather than a distant threat. The last drought of this magnitude may have occurred more than 800 years ago, and the 2012 drought has been du...

  19. Use of fine resolution terrain data in soil loss equations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Dust Bowl of the 1930's focused US attention on soil erosion and land conservation. The Universal Soil Loss Equation (USLE) was the result of this effort and has remained one of the most widely used equations for soil erosion prediction world-wide. This empirical relationship has been incorporat...

  20. Soil erosion: 20th century equations with 21st century data?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Dust Bowl of the 1930's focused the attention of the US on soil erosion and land conservation. The Universal Soil Loss Equation (USLE) was the result of this effort and has remained one of the most widely used equations for soil erosion prediction world-wide. This empirical relationship has been...

  1. Current Erosion and Sediment Research Concerns in Agricultural Watersheds in the USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil erosion research programs in the USA began in earnest following events of the 1933 Dust Bowl. During the early years from the 1930s-1960s, the focus was on determining the scale and severity of this problem by making measurements on plots, field-size areas, and small agricultural watersheds. Th...

  2. Optical properties of Aeolian dusts common to West Texas

    NASA Astrophysics Data System (ADS)

    Ma, Lulu; Zobeck, Ted M.; Hsieh, Daniel H.; Holder, Dean; Morgan, Cristine L. S.; Thompson, Jonathan E.

    2011-11-01

    Both recent models and historical events such as the Dust Bowl and volcanic eruptions have illustrated aerosols can play a significant role in climate change through direct and indirect optical effects. Soil dust aerosols generated by Aeolian processes represent a significant fraction of the total mass burden of atmospheric particles. Central to a better understanding of the climate effects of dust aerosols is knowledge of their optical properties. This research study utilized a dust generator and several instruments to determine certain optical properties of Aeolian dust mimics created by the Amarillo and Pullman soil types native to the panhandle of Texas, USA. Values for the mass-extinction coefficient ranged between 1.74 and 2.97 m 2 g -1 at 522 nm depending on how mass concentration was determined. Single-scatter albedo (SSA) for both soil types ranged from 0.947 to 0.980 at visible wavelengths with SSA increasing at longer wavelengths. Angstrom absorption exponents were measured as 1.73 for Pullman and 2.17 for Amarillo soil. Observed Angstrom extinction exponents were 0.110 and 0.168 for the Pullman and Amarillo soil types. The optical properties reported may be of use for optical based estimates of soil erosion and aid in understanding how regional soil dusts may alter radiative transport presently and during historical events such as the Dust Bowl era.

  3. Method and device for disinfecting a toilet bowl

    DOEpatents

    Almon, A.C.

    1997-03-18

    Method and device are disclosed for disinfecting a flush toilet. The device is an electrolytic cell mounted in the tank of the toilet, with two wire mesh electrodes immersed in the water in the tank and a battery applying approximately one to two volts of electric potential to the electrodes so that they chemically reduce a portion of the water in the tank to hydrogen peroxide. Then, when the tank is flushed, the peroxide is carried into the bowl where it can kill bacteria. 2 figs.

  4. Method and device for disinfecting a toilet bowl

    SciTech Connect

    Almon, A.C.

    1992-12-31

    This invention is comprised of a method and device for disinfecting a flush toilet. The device is an electrocell mounted in the tank of the toilet, with two wire mesh electrodes immersed in the water in the tank and a battery applying approximately one to two volts of electric potential to the electrodes so that they chemically reduce a portion of the water in the tank to hydrogen peroxide. Then, when the tank is flushed, the peroxide is carried into the bowl where it can kill bacteria.

  5. Size of food bowl and scoop affects amount of food owners feed their dogs.

    PubMed

    Murphy, M; Lusby, A L; Bartges, J W; Kirk, C A

    2012-04-01

    The incidence of canine obesity appears to be increasing dramatically and understanding factors impacting the amount of food pet owners provide their dogs may improve weight management. Human research has shown the size of food bowls, plates and utensils can significantly impact the amount of food portioned and consumed. This effect can be attributed to both the Delboeuf optical illusion and the Ebbinghaus-Titchener size-contrast illusion. To investigate the existence of a similar effect with dog owners, 54 dogs and their owners were recruited for a four treatment randomized prospective trial. Owners scooped out a normal kibble-based meal using a small bowl and small scoop, small bowl and large scoop, large bowl and small scoop or a large bowl and large scoop. Each treatment was used once per owner over four visits. Repeated measures anova revealed the mean amount of food portioned using the small bowl and small scoop was significantly less than all other bowl and scoop combinations (150.7 g vs. 171.5 g vs. 172.7 g vs. 184.5 g, p < 0.05). The small bowl and large scoop combination did not differ from large bowl and small scoop (171.5 g vs. 172.7 g, p > 0.05). Owners were more likely to portion a larger amount of food with a large bowl and large scoop. Results are consistent with human data and emphasize the need for owners to use standard measuring cups. Results also suggest owner compliance during weight loss programs may be improved with smaller bowls and serving scoops.

  6. Effectiveness of bowl trapping and netting for inventory of a bee community

    USGS Publications Warehouse

    Grundel, R.; Frohnapple, K.J.; Jean, R.P.; Pavlovic, N.B.

    2011-01-01

    Concern over the status of bees has increased the need to inventory bee communities and, consequently, has increased the need to understand effectiveness of different bee sampling methods. We sampled bees using bowl traps and netting at 25 northwest Indiana sites ranging from open grasslands to forests. Assemblages of bees captured in bowl traps and by netting were very similar, but this similarity was driven by similar relative abundances of commonly captured species. Less common species were often not shared between collection methods (bowls, netting) and only about half of the species were shared between methods. About one-quarter of species were more often captured by one of the two collection methods. Rapid accumulation of species was aided by sampling at temporal and habitat extremes. In particular, collecting samples early and late in the adult flight season and in open and forest habitats was effective in capturing the most species with the fewest samples. The number of samples estimated necessary to achieve a complete inventory using bowls and netting together was high. For example, ≈72% of species estimated capturable in bowls were captured among the 3,159 bees collected in bowls in this study, but ≈30,000–35,000 additional bees would need to be collected to achieve a 100% complete inventory. For bowl trapping, increasing the number of sampling dates or sampling sites was more effective than adding more bowls per sampling date in completing the inventory with the fewest specimens collected.

  7. A Viewer Survey of the Expanded WBGU-TV Audience, Bowling Green, Ohio.

    ERIC Educational Resources Information Center

    Clark, David W.

    Contained in this report are the results of a telephone survey conducted among 961 households in the television market for Bowling Green, Ohio. The purpose of the survey was to determine the characteristics of the viewing audience for WBGU. WBGU--owned by Bowling Green State University--became the public television station for a 19-county area in…

  8. Bowling-Fencing Guide with Official Rules. January 1973 - January 1975.

    ERIC Educational Resources Information Center

    Docherty, Ethel, Ed.; Curry, Nancy L., Ed.

    Rules for women's bowling and fencing from January 1973 to January 1975 are discussed. Standards in sports for girls and women are detailed along with the Division for Girls and Women's Sports (DGWS) statement of beliefs. Specific articles dealing with bowling skills, norms, and rules for women are included. Articles are also included on the…

  9. Bowling Together: Cultivating Communities of Practice in English and Social Studies Teacher Education

    ERIC Educational Resources Information Center

    Spalding, Elizabeth; Wilson, Angene H.

    2006-01-01

    In his sociological study Bowling Alone: The Collapse and Revival of American Community (2000), Robert Putnam argues that Americans need to "reconnect to one another" and, both metaphorically and literally, go bowling together (p. 28). The authors--an English educator and a social studies educator--describe a four year collaboration that has led…

  10. 77 FR 75550 - Special Local Regulations; 2013 Orange Bowl Paddle Championship, Biscayne Bay, Miami, FL

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-21

    ... SECURITY Coast Guard 33 CFR Part 100 RIN 1625-AA08 Special Local Regulations; 2013 Orange Bowl Paddle... in Miami, FL during the 2013 Orange Bowl Paddle Championship. The event will take place on January 13... purpose of the rule is to provide for the safety of life on navigable waters during the 2013 Orange...

  11. Characteristics of bowl-shaped coils for transcranial magnetic stimulation

    NASA Astrophysics Data System (ADS)

    Yamamoto, Keita; Suyama, Momoko; Takiyama, Yoshihiro; Kim, Dongmin; Saitoh, Youichi; Sekino, Masaki

    2015-05-01

    Transcranial magnetic stimulation (TMS) has recently been used as a method for the treatment of neurological and psychiatric diseases. Daily TMS sessions can provide continuous therapeutic effectiveness, and the installation of TMS systems at patients' homes has been proposed. A figure-eight coil, which is normally used for TMS therapy, induces a highly localized electric field; however, it is challenging to achieve accurate coil positioning above the targeted brain area using this coil. In this paper, a bowl-shaped coil for stimulating a localized but wider area of the brain is proposed. The coil's electromagnetic characteristics were analyzed using finite element methods, and the analysis showed that the bowl-shaped coil induced electric fields in a wider area of the brain model than a figure-eight coil. The expanded distribution of the electric field led to greater robustness of the coil to the coil-positioning error. To improve the efficiency of the coil, the relationship between individual coil design parameters and the resulting coil characteristics was numerically analyzed. It was concluded that lengthening the outer spherical radius and narrowing the width of the coil were effective methods for obtaining a more effective and more uniform distribution of the electric field.

  12. Dust structurization observed in a dc glow discharge dusty plasma

    NASA Astrophysics Data System (ADS)

    Heinrich, Jonathon R.; Kim, Su-Hyun; Merlino, Robert L.

    2010-11-01

    Dusty plasmas, which are inherently open systems which require an ionization source to replenish the plasma absorbed on the grains, tend to exhibit self-organization. Various structures have been observed in dusty plasmas such as dust crystals, voids, and vortices. Due to the presence of drifting ions in dc discharge plasmas, spontaneously excited dust acoustic waves are also a common occurrence. By adjusting the discharge parameters we have observed a new phenomenon in dusty plasmas -- the spontaneous formation of three-dimensional stationary dust density structures. These structures appear as an ordered pattern consisting of alternating regions of high and low dust density arranged in a nested bowl-type configuration The stationary structure evolves from dust density waves that slow down as their wavelength decreases and eventually stop moving when the wavelength reaches some minimum size.

  13. Empty Bowls Feed the Hungry: Service Learning across the Curriculum with the Visual Arts at the Core.

    ERIC Educational Resources Information Center

    Namnoun, Donna

    2002-01-01

    Describes a school-wide, cross-curricular project called, "Empty Bowls", at Hall High School (West Hartford, Connecticut). Explains that students created ceramic bowls and made soup to fill the bowls to raise money to fight hunger. Provides a description of how the school became involved and raised the money. (CMK)

  14. Synthesis of Nano-Bowls with a Janus Template

    PubMed Central

    Emerson, Chris D.; Zhang, Chen; Anzenberg, Paula; Akkiraju, Siddhartha; Lal, Ratnesh

    2015-01-01

    Colloidal particles with two or more different surface properties (Janus particles) are of interest in catalysis, biological imaging, and drug delivery. Eccentric nanoparticles are a type of Janus particle consisting of a shell that envelops the majority of a core particle, leaving a portion of the core surface exposed. Previous work to synthesize eccentric nanoparticles from silica and polystyrene have only used microemulsion techniques. In contrast we report the solgel synthesis of eccentric Janus nanoparticles composed of a silica shell around a carboxylate-modified polystyrene core (Janus templates). In addition, we have synthesized nano-bowl-like structures after the removal of the polystyrene core by organic solvent. These Janus templates and nanobowls can be used as a versatile platform for site-specific functionalization or controlled theranostic delivery. PMID:25431230

  15. Children of the Harvest: The Schooling of Dust Bowl and Mexican Migrants during the Depression Era.

    ERIC Educational Resources Information Center

    Theobald, Paul; Donato, Ruben

    1990-01-01

    Chronicles experiences of depression era "Okies," juxtaposes them against experiences of Mexican Americans, and illuminates the diminution of agricultural labor in an industrializing society. Schooling for those groups was legitimized by their low occupational status. When economic circumstances improved, whites escaped from migrant…

  16. Ethnicity and Class: The Schooling of Dust Bowl and Mexican Migrants during the Depression Era.

    ERIC Educational Resources Information Center

    Theobald, Paul; Donato, Ruben

    1993-01-01

    Although both Mexican-American and "Okie" migrants to California and the Pacific Northwest suffered discrimination, the assimilation and mobility of later generations of Okies contrasts with the racism, school segregation, and perpetuation of class divisions in the experience of Mexican Americans. (SK)

  17. Synthesis of nano-bowls with a Janus template

    NASA Astrophysics Data System (ADS)

    Mo, Alexander H.; Landon, Preston B.; Emerson, Chris D.; Zhang, Chen; Anzenberg, Paula; Akkiraju, Siddhartha; Lal, Ratnesh

    2014-12-01

    Colloidal particles with two or more different surface properties (Janus particles) are of interest in catalysis, biological imaging, and drug delivery. Eccentric nanoparticles are a type of Janus particle consisting of a shell that envelops the majority of a core particle, leaving a portion of the core surface exposed. Previous work to synthesize eccentric nanoparticles from silica and polystyrene have only used microemulsion techniques. In contrast we report the sol-gel synthesis of eccentric Janus nanoparticles composed of a silica shell around a carboxylate-modified polystyrene core (Janus templates). In addition, we have synthesized nano-bowl-like structures after the removal of the polystyrene core by organic solvent. These Janus templates and nanobowls can be used as a versatile platform for site-specific functionalization or controlled theranostic delivery.Colloidal particles with two or more different surface properties (Janus particles) are of interest in catalysis, biological imaging, and drug delivery. Eccentric nanoparticles are a type of Janus particle consisting of a shell that envelops the majority of a core particle, leaving a portion of the core surface exposed. Previous work to synthesize eccentric nanoparticles from silica and polystyrene have only used microemulsion techniques. In contrast we report the sol-gel synthesis of eccentric Janus nanoparticles composed of a silica shell around a carboxylate-modified polystyrene core (Janus templates). In addition, we have synthesized nano-bowl-like structures after the removal of the polystyrene core by organic solvent. These Janus templates and nanobowls can be used as a versatile platform for site-specific functionalization or controlled theranostic delivery. Electronic supplementary information (ESI) available: Particle size distribution before and after centrifugation during the wash process, SEM and TEM images used in quantification of Janus template yield and population break down. See DOI: 10

  18. Spatial patterns of bee captures in North American bowl trapping surveys

    USGS Publications Warehouse

    Droege, Sam; Tepedino, Vincent J.; Lebuhn, Gretchen; Link, William; Minckley, Robert L.; Chen, Qian; Conrad, Casey

    2010-01-01

    1. Bowl and pan traps are now commonly used to capture bees (Hymenoptera: Apiformes) for research and surveys. 2. Studies of how arrangement and spacing of bowl traps affect captures of bees are needed to increase the efficiency of this capture technique. 3. We present results from seven studies of bowl traps placed in trapping webs, grids, and transects in four North American ecoregions (Mid-Atlantic, Coastal California, Chihuahuan Desert, and Columbia Plateau). 4. Over 6000 specimens from 31 bee genera were captured and analysed across the studies. 5. Based on the results from trapping webs and distance tests, the per bowl capture rate of bees does not plateau until bowls are spaced 3–5 m apart. 6. Minor clumping of bee captures within transects was detected, with 26 of 56 transects having index of dispersion values that conform to a clumped distribution and 39 transects having positive Green's index values, 13 with zero, and only four negative. However, degree of clumping was slight with an average value of only 0.06 (the index ranges from -1 to 1) with only five values >0.15. Similarly, runs tests were significant for only 5.9% of the transects. 7. Results indicate that (i) capture rates are unaffected by short distances between bowls within transects and (ii) that bowls and transects should be dispersed throughout a study site.

  19. Cosmic dust

    NASA Technical Reports Server (NTRS)

    Brownlee, Donald E.; Sandford, Scott A.

    1992-01-01

    Dust is a ubiquitous component of our galaxy and the solar system. The collection and analysis of extraterrestrial dust particles is important to exobiology because it provides information about the sources of biogenically significant elements and compounds that accumulated in distant regions of the solar nebula and that were later accreted on the planets. The topics discussed include the following: general properties of interplanetary dust; the carbonaceous component of interplanetary dust particles; and the presence of an interstellar component.

  20. The development of a novel cricket bowling system: recreating spin and swing bowling deliveries at the elite level

    NASA Astrophysics Data System (ADS)

    West, A. A.; Justham, L.

    2008-03-01

    During the game of cricket, bowlers create different deliveries by altering the manner in which they release the ball from their hand. The orientation of the seam, the speed at which the ball is released and the magnitude and direction of the spin combine to determine the motion of the ball through the air and its movement after impact with the wicket. These factors have to be considered if automatic training machines are to be capable of replicating elite bowling deliveries. The need for automotive systems for batting and fielding training at the elite level has arisen due to: (i) the capabilities of human bowlers are limited by the onset of fatigue and the risk of injury and (ii) a large number of accurate and repeatable deliveries to be ''programmable'' by coaches to ensure batsmen and fielders are tested to the limits of their abilities and a training benefit is achieved.

  1. 76 FR 52733 - Notice of Intent To Rule on Change in Use of Aeronautical Property at Bowling Green-Warren County...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-23

    ... Bowling Green--Warren County Regional Airport, Bowling Green, KY AGENCY: Federal Aviation Administration... requesting public comment on request by the Bowling Green--Warren County Airport Board to change a portion of airport property ] from aeronautical to non-aeronautical use at the Bowling Green--Warren County...

  2. Circumstellar dust

    NASA Technical Reports Server (NTRS)

    Dwek, E.

    1986-01-01

    The presence of dust in the general interstellar medium is inferred from the extinction, polarization, and scattering of starlight; the presence of dark nebulae; interstellar depletions; the observed infrared emission around certain stars and various types of interstellar clouds. Interstellar grains are subject to various destruction mechanisms that reduce their size or even completely destroy them. A continuous source of newly formed dust must therefore be present for dust to exist in the various phases of the interstellar medium (ISM). The working group has the following goals: (1) review the evidences for the formation of dust in the various sources; (2) examine the clues to the nature and composition of the dust; (3) review the status of grain formation theories; (4) examine any evidence for the processing of the dust prior to its injection into the interstellar medium; and (5) estimate the relative contribution of the various sources to the interstellar dust population.

  3. The preference for water nipples vs. water bowls in dairy goats

    PubMed Central

    2011-01-01

    Background Previous studies have reported that the design of the water dispensers can influence the water intake in farm animals. Horses and dairy cows seem to prefer to drink from an open surface whereas sheep and pigs apparently prefer water nipples, probably because of the worse water quality in water bowls. The aim of the present study was to examine the preference of dairy goats for water nipples or water bowls. Methods In each of the two experiments (exp. 1, dry goats, exp. 2 lactating goats), 42 dairy goats were allotted into 6 groups of 7 goats. In period 1, the goats had access to a water nipple. In period 2, they had access to a water bowl and in period 3 (preference test) they had access to both a water nipple and a water bowl. Water usage and wastage was recorded and water intake (water usage - water wastage) was calculated for each group for the two last days of each period. In experiment 2, water samples from each dispenser were analyzed for heterotrophy germs at 22°C, Escherichia coli and turbidity. Results Water usage was higher from water nipples than from water bowls both in experiment 1 (dry goats) and experiment 2 (lactating goats). There was however, no difference in water intake from water nipples and water bowls. In the preference test (period 3), the water intake tended to be higher from the water nipple than from the water bowl both for the dry goats (exp. 1) and lactating goats (exp. 2). Especially for the dry goats, the differences between groups were large. Turbidity and heterotrophy germs were much higher in the samples from the water bowls than from the water nipples. Water wastage from the water bowls was negligible compared to the water nipples. From the water nipples the water wastage was 30% and 23% of water usage for the dry and lactating goats respectively. Conclusions We conclude that type of water dispenser (nipple or bowl) was probably of minor importance for water intake in goats, but water bowls had a lower water quality

  4. An integrated approach to the biomechanics and motor control of cricket fast bowling techniques.

    PubMed

    Glazier, Paul S; Wheat, Jonathan S

    2014-01-01

    To date, scientific investigations into the biomechanical aspects of cricket fast bowling techniques have predominantly focused on identifying the mechanical factors that may predispose fast bowlers to lower back injury with a relative paucity of research being conducted on the technical features that underpin proficient fast bowling performance. In this review paper, we critique the scientific literature examining fast bowling performance. We argue that, although many published investigations have provided some useful insights into the biomechanical factors that contribute to a high ball release speed and, to a lesser extent, bowling accuracy, this research has not made a substantive contribution to knowledge enhancement and has only had a very minor influence on coaching practice. To significantly enhance understanding of cricket fast bowling techniques and, therefore, have greater impact on practice, we recommend that future scientific research adopts an interdisciplinary focus, integrating biomechanical measurements with the analytical tools and concepts of dynamical systems motor control theory. The use of qualitative (topological) analysis techniques, in particular, promises to increase understanding of the coordinative movement patterns that define 'technique' in cricket fast bowling and potentially help distinguish between functional and dysfunctional aspects of technique for individual fast bowlers.

  5. Protoplanetary Dust

    NASA Astrophysics Data System (ADS)

    Apai, D.´niel; Lauretta, Dante S.

    2014-02-01

    Preface; 1. Planet formation and protoplanetary dust Daniel Apai and Dante Lauretta; 2. The origins of protoplanetary dust and the formation of accretion disks Hans-Peter Gail and Peter Hope; 3. Evolution of protoplanetary disk structures Fred Ciesla and Cornelius P. Dullemond; 4. Chemical and isotopic evolution of the solar nebula and protoplanetary disks Dmitry Semenov, Subrata Chakraborty and Mark Thiemens; 5. Laboratory studies of simple dust analogs in astrophysical environments John R. Brucato and Joseph A. Nuth III; 6. Dust composition in protoplanetaty dust Michiel Min and George Flynn; 7. Dust particle size evolution Klaus M. Pontoppidan and Adrian J. Brearly; 8. Thermal processing in protoplanetary nebulae Daniel Apai, Harold C. Connolly Jr. and Dante S. Lauretta; 9. The clearing of protoplanetary disks and of the protosolar nebula Ilaira Pascucci and Shogo Tachibana; 10. Accretion of planetesimals and the formation of rocky planets John E. Chambers, David O'Brien and Andrew M. Davis; Appendixes; Glossary; Index.

  6. Study of flow through a bowl mill model

    SciTech Connect

    Murty, G.V.R.; Babu, U.S.

    1998-07-01

    Bowl Mills are used in Thermal Power plants for pulverizing the raw coal, while drying, to the required fineness and achieve the desired combustion efficiency in the boiler. The Indian coals contain high ash content (some times as high as 60%) and as such the primary air has to handle media of different density namely the coal and the quartz. In this context, the distribution of air in the mill plays a significant role in the lifting of particles from the mill. The wear on the rotating components is increased through repetitive grinding because of improper distribution of air within the mill. Reduction of wear and enhancement of life of mill internals including the rotating components is a continuing goal and few more studies have been carried out in this direction. One such study is the replacement of rotating vane wheel and deflector in the separator body with an air guide ring and air diversion plate. Model studies have been carried out by traversing a five hole prove at different locations within the mill to study the distribution of flow as a result of this modification. The variation of absolute velocity and the associated flow direction has been calculated to describe the flow structure within the mill. The results are presented in non dimensional form to draw suitable conclusions. The present study indicated the possibility of improvement in the distribution of flow within the mill with increased magnitude of velocity at different locations.

  7. Evaluation of American Indian Science and Engineering Society Intertribal Middle School Science and Math Bowl Project

    SciTech Connect

    AISES, None

    2013-09-25

    The American Indian Science and Engineering Society (AISES) has been funded under a U.S. Department of Energy (DOE) grant (Grant Award No. DE-SC0004058) to host an Intertribal Middle-School Science and Math Bowl (IMSSMB) comprised of teams made up of a majority of American Indian students from Bureau of Indian Education-funded schools and public schools. The intent of the AISES middle school science and math bowl is to increase participation of American Indian students at the DOE-sponsored National Science Bowl. Although national in its recruitment scope, the AISES Intertribal Science and Math Bowl is considered a “regional” science bowl, equivalent to the other 50 regional science bowls which are geographically limited to states. Most regional bowls do not have American Indian student teams competing, hence the AISES bowl is meant to encourage American Indian student teams to increase their science knowledge in order to participate at the national level. The AISES competition brings together teams from various American Indian communities across the nation. Each team is provided with funds for travel to and from the event, as well as for lodging and meals. In 2011 and 2012, there were 10 teams participating; in 2013, the number of teams participating doubled to 20. Each Science and Math Bowl team is comprised of four middle school — grades 6 through 8 — students, one alternate, and a teacher who serves as advisor and coach — although in at least two cases, the coach was not a teacher, but was the Indian Education Coordinator. Each team member must have at least a 3.0 GPA. Furthermore, the majority of students in each team must be comprised of American Indian, Alaska Native or Native Hawaiian students. Under the current DOE grant, AISES sponsored three annual middle school science bowl competitions over the years 2011, 2012 and 2013. The science and math bowls have been held in late March concurrently with the National American Indian Science and

  8. China Dust

    Atmospheric Science Data Center

    2013-04-16

    ... SpectroRadiometer (MISR) nadir-camera images of eastern China compare a somewhat hazy summer view from July 9, 2000 (left) with a ... arid and sparsely vegetated surfaces of Mongolia and western China pick up large quantities of yellow dust. Airborne dust clouds from the ...

  9. Andromeda's dust

    SciTech Connect

    Draine, B. T.; Aniano, G.; Krause, Oliver; Groves, Brent; Sandstrom, Karin; Klaas, Ulrich; Linz, Hendrik; Rix, Hans-Walter; Schinnerer, Eva; Schmiedeke, Anika; Walter, Fabian; Braun, Robert; Leroy, Adam E-mail: ganiano@ias.u-psud.fr

    2014-01-10

    Spitzer Space Telescope and Herschel Space Observatory imaging of M31 is used, with a physical dust model, to construct maps of dust surface density, dust-to-gas ratio, starlight heating intensity, and polycyclic aromatic hydrocarbon (PAH) abundance, out to R ≈ 25 kpc. The global dust mass is M {sub d} = 5.4 × 10{sup 7} M {sub ☉}, the global dust/H mass ratio is M {sub d}/M {sub H} = 0.0081, and the global PAH abundance is (q {sub PAH}) = 0.039. The dust surface density has an inner ring at R = 5.6 kpc, a maximum at R = 11.2 kpc, and an outer ring at R ≈ 15.1 kpc. The dust/gas ratio varies from M {sub d}/M {sub H} ≈ 0.026 at the center to ∼0.0027 at R ≈ 25 kpc. From the dust/gas ratio, we estimate the interstellar medium metallicity to vary by a factor ∼10, from Z/Z {sub ☉} ≈ 3 at R = 0 to ∼0.3 at R = 25 kpc. The dust heating rate parameter (U) peaks at the center, with (U) ≈ 35, declining to (U) ≈ 0.25 at R = 20 kpc. Within the central kiloparsec, the starlight heating intensity inferred from the dust modeling is close to what is estimated from the stars in the bulge. The PAH abundance reaches a peak q {sub PAH} ≈ 0.045 at R ≈ 11.2 kpc. When allowance is made for the different spectrum of the bulge stars, q {sub PAH} for the dust in the central kiloparsec is similar to the overall value of q {sub PAH} in the disk. The silicate-graphite-PAH dust model used here is generally able to reproduce the observed dust spectral energy distribution across M31, but overpredicts 500 μm emission at R ≈ 2-6 kpc, suggesting that at R = 2-6 kpc, the dust opacity varies more steeply with frequency (with β ≈ 2.3 between 200 and 600 μm) than in the model.

  10. Medieval Loess Constraints On the Climate Effect of Dust Aerosols In the Great Plains of North America

    NASA Astrophysics Data System (ADS)

    Miller, R. L.; Cook, B. I.; Seager, R.; Mason, J. A.

    2011-12-01

    Loess deposits in the Great Plains of North America, together with tree ring records, suggest the occurrence of medieval megadroughts within the past millenium when rainfall was below average over several decades. Loess results from the deposition of dust aerosols, created by wind erosion, perhaps following vegetation loss after extended drought. Dust aerosols have been previously shown to exacerbate the absence of rainfall during the twentieth century Dust Bowl, reinforcing the drought and loss of vegetation. Ocean temperatures in the equatorial Pacific make the predominant contribution to hydroclimate variability in this region, but dust may have had an amplifying effect during the medieval drought once the vegetation loss was sufficiently extensive. Here, we describe GCM experiments with dust aerosols created by wind erosion over medieval sources within North America. Our goal is twofold: first, to calculate the climate effect of dust, which is believed to reduce precipitation during the Dust Bowl. Second, we calculate dust deposition for comparison to the observed thickness of loess deposits. This comparison serves as a constraint upon the total dust mobilization and the aerosol effect upon precipitation, both of which depend upon the incompletely known source extent and its productivity.

  11. The effect of a flexed elbow on bowling speed in cricket.

    PubMed

    Marshall, Robert; Ferdinands, René

    2003-01-01

    The laws of bowling in cricket state 'a ball is fairly delivered in respect of the arm if, once the bowler's arm has reached the level of the shoulder in the delivery swing, the elbow joint is not straightened partially or completely from that point until the ball has left the hand'. Recently two prominent bowlers, under suspicion for transgressing this law, suggested that they are not 'throwing' but due to an elbow deformity are forced to bowl with a bent bowling arm. This study examined whether such bowlers can produce an additional contribution to wrist/ball release speed by internal rotation of the upper arm. The kinematics of a bowling arm were calculated using a simple two-link model (upper arm and forearm). Using reported internal rotation speeds of the upper arm from baseball and waterpolo, and bowling arm kinematics from cricket, the change in wrist speed was calculated as a function of effective arm length, and wrist distance from the internal rotation axis. A significant increase in wrist speed was noted. This suggests that bowlers who can maintain a fixed elbow flexion during delivery can produce distinctly greater wrist/ball speeds by using upper arm internal rotation.

  12. Shadow Bowl 2003: a collaborative exercise in community readiness, agency cooperation, and medical response.

    PubMed

    Balch, David; Taylor, Carl; Rosenthal, David; Bausch, Chris; Warner, Dave; Morris, Ray

    2004-01-01

    This paper describes a model for homeland security, community readiness, and medical response that was applied during an operational exercise around Super Bowl XXXVII. In addition, it describes the products provided by private companies involved in the exercise and how they would have contributed to a medical disaster had one occurred. The purpose of Shadow Bowl was to demonstrate community readiness and medical response to a mass casualty event. The goals of the project were to: (1) provide enhanced public safety using an advanced communication network and sensor grid; (2) develop mass casualty surge capabilities through medical reach-back; and (3) build a collaboration model between civilian, military, public, and private partners. The results of the Shadow Bowl Exercise accentuated the value of new telehealth and disaster medicine tools in treating large numbers of patients when infrastructure overload occurs.

  13. Exozodiacal dust

    NASA Astrophysics Data System (ADS)

    Kuchner, Marc Jason

    Besides the sun, the most luminous feature of the solar system is a cloud of "zodiacal" dust released by asteroids and comets that pervades the region interior to the asteroid belt. Similar clouds of dust around other stars---exozodiacal clouds---may be the best tracers of the habitable zones of extra-solar planetary systems. This thesis discusses three searches for exozodiacal dust: (1) We observed six nearby main-sequence stars with the Keck telescope at 11.6 microns, correcting for atmosphere-induced wavefront aberrations and deconvolving the point spread function via classical speckle analysis. We compare our data to a simple model of the zodiacal dust in our own system based on COBE DIRBE observations and place upper limits on the density of exozodiacal dust in these systems. (2) We observed Sirius, Altair, and Procyon with the NICMOS Coronagraph on the Hubble Space Telescope to look for scattered light from exozodiacal dust and faint companions within 10 AU from these stars. (3) The planned nulling capability of the Keck Interferometer should allow it to probe the region <200 milliarcsecond from a bright star and to suppress on-axis starlight by factors of 10 -3 to reveal faint circumstellar material. We model the response of the Keck Interferometer to hypothetical exozodiacal clouds to derive detection limits that account for the effects of stellar leakage, photon noise, noise from null depth fluctuations, and the fact that the cloud's shape is not known a priori. We also discuss the interaction of dust with planets. We used the COBE DIRBE Sky and Zodi Atlas and the IRAS Sky Survey Atlas to search for dynamical signatures of three different planets in the solar system dust complex: (1) We searched the COBE DIRBE Sky and Zodi Atlas for a wake of dust trailing Mars. We compare the DIRBE images to a model Mars wake based on the empirical model of the Earth's wake as seen by the DIRBE. (2) We searched the COBE DIRRE Sky and Zodi Atlas for Tiojan dust near

  14. ENVIRONMENTAL TECHNOLOGY VERIFICATION: JOINT (NSF-EPA) VERIFICATION STATEMENT AND REPORT: TRITON SYSTEMS, LLC SOLID BOWL CENTRIFUGE, MODEL TS-5000

    EPA Science Inventory

    Verification testing of the Triton Systems, LLC Solid Bowl Centrifuge Model TS-5000 (TS-5000) was conducted at the Lake Wheeler Road Field Laboratory Swine Educational Unit in Raleigh, North Carolina. The TS-5000 was 48" in diameter and 30" deep, with a bowl capacity of 16 ft3. ...

  15. Environmental Assessment: Proposed Construction of Air Force Non-Appropriated Funds Bowling Center at Maxwell Air Force Base, Gunter Annex

    DTIC Science & Technology

    2004-04-01

    with a Signature Brand “Classics Diner”, could generate increased revenue by providing an additional number of bowling lanes. Food and beverage income...number of bowling lanes. Food and beverage income is also anticipated to grow. The increased income would also create additional jobs and would be... Mall ...................................................................................... 5-2 5.3 CUMULATIVE EFFECTS ANALYSIS

  16. Stability of polar frosts in spherical bowl-shaped craters on the moon, Mercury, and Mars

    NASA Technical Reports Server (NTRS)

    Ingersoll, Andrew P.; Svitek, Tomas; Murray, Bruce C.

    1992-01-01

    A model of spherical bowl-shaped craters is described and applied to the moon, Mercury, and Mars. The maximum temperature of permanently shadowed areas are calculated using estimates of the depth/diameter ratios of typical lunar bowl-shaped craters and assuming a saturated surface in which the craters are completely overlapping. For Mars, two cases are considered: water frost in radiative equilibrium and subliming CO2 frost in vapor equilibrium. Energy budgets and temperatures are used to determine whether a craterlike depression loses mass faster or slower than a flat horizontal surface. This reveals qualitatively whether the frost surface becomes rougher or smoother as it sublimes.

  17. Net Assessment in the 1930s

    DTIC Science & Technology

    1990-10-01

    New York, 1965) and George C. Marshall: Organizer of Victory. 1943- 194. (New York, 1973). 5. Richard F. Haynes, The Awesome Power: Harry S. Truman...1920 (Turin, 1965), Mussolini it fascista. I 1 297 5 I. La conguista del potere . 1921-1925 (Turin, 1966), Mussolini il fascista. IL L𔃺r**nizaione dello...Activities," 22 Nov. 1926; Harry J. Psomiades, "The Diplomacy of Theodoros Pangalos, 1925- 1926," ]alkaLStudies, no. 1 (1972); Thle Keyesjpes, Vol. II

  18. German Strategic Deception in the 1930s.

    DTIC Science & Technology

    1980-07-01

    passed 1 customs in coffins labeled machine parts. The German Defense Ministry established the national airline, Lufthansa, in January 1926. Felmy ...night, strike fear in the hearts of the enemy population." At the same time, Felmy submitted a 1Schliephake, op. cit., p, 27. 2Ibid. 3Suchenwirth, op...cit., p. 38. 4Homze, op. cit., p. 32. 5Ibid., p. 33. us 47 rearmament plan that echoed Wimmer’s Douhetian sentiments. Felmy proposed an 80 squadron air

  19. Reach for Reference. Nostalgia for Teachers, History for Students: Bowling, Beatniks, and Bell-Bottoms

    ERIC Educational Resources Information Center

    Safford, Barbara Ripp

    2005-01-01

    This article describes the U-X-L encyclopedia "Bowling, Beatniks, and Bell-Bottoms: Pop Culture of 20th Century America," a five-volume set, arranged chronologically with two decades in each volume. Each decade then is divided into topics, such as commerce (more exciting than it sounds with lots of inventions, consumer goods, and technology); film…

  20. Does Becoming a Member of the Football Bowl Subdivision Increase Institutional Attractiveness to Potential Students

    ERIC Educational Resources Information Center

    Jones, Willis A.

    2014-01-01

    In recent years, a number of colleges and universities have made the decision to pursue membership in the NCAA's Football Bowl Subdivision (FBS) with the idea that participating in higher profile intercollegiate football can help attract students to their institution. This belief, however, has not been empirically examined. Using…

  1. Barium ions selectively activate BK channels via the Ca2+-bowl site.

    PubMed

    Zhou, Yu; Zeng, Xu-Hui; Lingle, Christopher J

    2012-07-10

    Activation of Ca(2+)-dependent BK channels is increased via binding of micromolar Ca(2+) to two distinct high-affinity sites per BK α-subunit. One site, termed the Ca(2+) bowl, is embedded within the second RCK domain (RCK2; regulator of conductance for potassium) of each α-subunit, while oxygen-containing residues in the first RCK domain (RCK1) have been linked to a separate Ca(2+) ligation site. Although both sites are activated by Ca(2+) and Sr(2+), Cd(2+) selectively favors activation via the RCK1 site. Divalent cations of larger ionic radius than Sr(2+) are thought to be ineffective at activating BK channels. Here we show that Ba(2+), better known as a blocker of K(+) channels, activates BK channels and that this effect arises exclusively from binding at the Ca(2+)-bowl site. Compared with previous estimates for Ca(2+) bowl-mediated activation by Ca(2+), the affinity of Ba(2+) to the Ca(2+) bowl is reduced about fivefold, and coupling of binding to activation is reduced from ∼3.6 for Ca(2+) to about ∼2.8 for Ba(2+). These results support the idea that ionic radius is an important determinant of selectivity differences among different divalent cations observed for each Ca(2+)-binding site.

  2. Elderly people's perceptions of using Wii sports bowling - A qualitative study.

    PubMed

    Glännfjord, Fredrik; Hemmingsson, Helena; Larsson Ranada, Åsa

    2016-12-14

    The Nintendo Wii is a gaming console with motion-sensitive controls that is making inroads into health care and rehabilitation. However, there is still limited knowledge on how elderly people perceive the use of such a product. The aim of this study was to examine how the use of the Wii Sports Bowling in an activity group was perceived by elderly people. The data consisted of observations and interviews with participants who used Wii Sports Bowling and was analysed with content analysis. The findings are described in three themes; 'The use of the Wii Sports game', 'Engagement in the game' and 'Social interaction around the activity'. Wii Sports Bowling was described as easier to play compared to real-life bowling and was enjoyable and a social activity. The opportunity to meet the group each week was important for the participants. Playing the game resulted in signs of immersion and a flow-like state. The Wii was perceived to be easy to use, to provide a way to socialize with peers and to give opportunities to participate in activities in a new way. More studies regarding elderly people's experiences and apprehensions regarding new technology such as gaming consoles and virtual reality are needed.

  3. Synthesis and characterization of pi-extended bowl-shaped pi-conjugated molecules.

    PubMed

    Amaya, Toru; Mori, Koichi; Wu, Hsyueh-Liang; Ishida, Satoshi; Nakamura, Jun-ichi; Murata, Kazuhiko; Hirao, Toshikazu

    2007-05-21

    A series of pi-extended bowl-shaped pi-conjugated compounds were synthesized from sumanene and characterized, and among them the terthiophene derivative showed a remarkable red-shifted absorption and small band gap, which wa rationalized by molecular orbital calculation.

  4. Selling College: A Longitudinal Study of American College Football Bowl Game Public Service Announcements

    ERIC Educational Resources Information Center

    Tobolowsky, Barbara F.; Lowery, John Wesley

    2014-01-01

    Using ideological analysis as a frame, researchers analyzed institutionally created commercials (PSAs) that appeared in 28 U.S. college football bowl games over a seven-year period (2003-2009) to better understand the universities' brands as represented in these advertisements. They found many common elements such as showing traditional…

  5. Reclassification to the NCAA Division I Football Bowl Subdivision: A Case Study at Western Kentucky University

    ERIC Educational Resources Information Center

    Upright, Paula A.

    2009-01-01

    The purpose of this study was to describe the reclassification process of Western Kentucky University's football program from the Football Championship Subdivision (FCS) to the Football Bowl Subdivision (FBS), the highest and most visible level of NCAA competition. Three research questions guided the study: (a) Why did Western Kentucky University…

  6. Climate, not conflict, explains extreme Middle East dust storm

    NASA Astrophysics Data System (ADS)

    Parolari, Anthony J.; Li, Dan; Bou-Zeid, Elie; Katul, Gabriel G.; Assouline, Shmuel

    2016-11-01

    The recent dust storm in the Middle East (Sepember 2015) was publicized in the media as a sign of an impending ‘Dust Bowl.’ Its severity, demonstrated by extreme aerosol optical depth in the atmosphere in the 99th percentile compared to historical data, was attributed to the ongoing regional conflict. However, surface meteorological and remote sensing data, as well as regional climate model simulations, support an alternative hypothesis: the historically unprecedented aridity played a more prominent role, as evidenced by unusual climatic and meteorological conditions prior to and during the storm. Remotely sensed normalized difference vegetation index demonstrates that vegetation cover was high in 2015 relative to the prior drought and conflict periods, suggesting that agricultural activity was not diminished during that year, thus negating the media narrative. Instead, meteorological simulations using the Weather Research and Forecasting (WRF) model show that the storm was associated with a cyclone and ‘Shamal’ winds, typical for dust storm generation in this region, that were immediately followed by an unusual wind reversal at low levels that spread dust west to the Mediterranean Coast. These unusual meteorological conditions were aided by a significant reduction in the critical shear stress due to extreme dry and hot conditions, thereby enhancing dust availability for erosion during this storm. Concluding, unusual aridity, combined with unique synoptic weather patterns, enhanced dust emission and westward long-range transport across the region, thus generating the extreme storm.

  7. “Nuisance Dust”: Unprotective Limits for Exposure to Coal Mine Dust in the United States, 1934–1969

    PubMed Central

    2013-01-01

    I examine the dismissal of coal mine dust as a mere nuisance, not a potentially serious threat to extractive workers who inhaled it. In the 1930s, the US Public Health Service played a major role in conceptualizing coal mine dust as virtually harmless. Dissent from this position by some federal officials failed to dislodge either that view or the recommendation of minimal limitations on workplace exposure that flowed from it. Privatization of regulatory authority after 1940 ensured that miners would lack protection against respiratory disease. The reform effort that overturned the established misunderstanding in the late 1960s critically depended upon both the production of scientific findings and the emergence of a subaltern movement in the coalfields. This episode illuminates the steep challenges often facing advocates of stronger workplace health standards. PMID:23237176

  8. Effects of Singing Bowl Sound Meditation on Mood, Tension, and Well-being: An Observational Study.

    PubMed

    Goldsby, Tamara L; Goldsby, Michael E; McWalters, Mary; Mills, Paul J

    2016-09-30

    Poor mood and elevated anxiety are linked to increased incidence of disease. This study examined the effects of sound meditation, specifically Tibetan singing bowl meditation, on mood, anxiety, pain, and spiritual well-being. Sixty-two women and men (mean age 49.7 years) participated. As compared with pre-meditation, following the sound meditation participants reported significantly less tension, anger, fatigue, and depressed mood (all Ps <.001). Additionally, participants who were previously naïve to this type of meditation experienced a significantly greater reduction in tension compared with participants experienced in this meditation (P < .001). Feeling of spiritual well-being significantly increased across all participants (P < .001). Tibetan singing bowl meditation may be a feasible low-cost low technology intervention for reducing feelings of tension, anxiety, and depression, and increasing spiritual well-being. This meditation type may be especially useful in decreasing tension in individuals who have not previously practiced this form of meditation.

  9. Synthesis, structures, and physical properties of aromatic molecular-bowl hydrocarbons.

    PubMed

    Wu, Yao-Ting; Siegel, Jay S

    2014-01-01

    This chapter summarizes the synthesis, physical properties, structure, and crystal packing of buckybowls. Buckybowls exemplify an intermediate class of polynuclear aromatic compounds between the closed-shell fullerenes and the flat extended arrays of graphene. These warped sheets can be seen as fragments of fullerenes or the end cap of single-walled carbon nanotubes; and, their curvature endows them with physical properties distinct from flat polynuclear hydrocarbons, which opens up unique possibilities for molecular bowls in various organic materials applications.

  10. Supramolecular control of a mononuclear biomimetic copper(II) center: bowl complexes vs funnel complexes.

    PubMed

    Gout, Jérôme; Višnjevac, Aleksandar; Rat, Stéphanie; Parrot, Arnaud; Hessani, Assia; Bistri, Olivia; Le Poul, Nicolas; Le Mest, Yves; Reinaud, Olivia

    2014-06-16

    Modeling the mononuclear site of copper enzymes is important for a better understanding of the factors controlling the reactivity of the metal center. A major difficulty stems from the difficult control of the nuclearity while maintaining free sites open to coordination of exogenous ligands. A supramolecular approach consists in associating a hydrophobic cavity to a tripodal ligand that will define the coordination spheres as well as access to the metal ion. Here, we describe the synthesis of a bowl Cu(II) complex based on the resorcinarene scaffold. This study supplements a previous work on Cu(I) coordination. It provides a complete picture of the cavity-copper system in its two oxidation states. The first XRD structure of such a bowl complex was obtained, evidencing a 5-coordinate Cu(II) ion with the three imidazole donors bound to the metal (two in the base of the pyramid, one in the apical position) and with an acetate anion, completing the base of the pyramid, and deeply included in the bowl. Solution studies conducted by EPR and UV-vis absorption spectroscopies as well as cyclic voltammetry highlighted interaction with coordinating solvents, various carboxylates that can sit either in the endo or in the exo position depending on their size as well as possible stabilization of hydroxo species in a mononuclear state. A comparison of the binding and redox properties of the bowl complex with funnel complexes based on the calix[6]arene core further highlights the importance of supramolecular features defining the first, second, and third coordination sphere for control of the metal ion.

  11. Supramolecular catalysis at work: diastereoselective synthesis of a molecular bowl with dynamic inner space.

    PubMed

    Yan, Zhiqing; McCracken, Troy; Xia, Shijing; Maslak, Veselin; Gallucci, Judith; Hadad, Christopher M; Badjić, Jovica D

    2008-01-18

    The supramolecular assistance to Pd(0)/Cu(I)-catalyzed cyclotrimerization of stannylated norbornene 7 has been investigated to give molecular bowl 1syn in a stereoselective fashion. Following a divergent strategy, racemic norbornene 7 was synthesized in satisfactory yield. Self-coupling, promoted by Pd(0)/Cu(I) catalysis acting in synergy with CsF, yielded molecular bowl 1syn in a moderate 30% yield. The reaction diastereoselectivity is affected by the concentration of Cu(I) and Cs+: increasing quantities of the cations enhanced the syn/anti ratio of the isolated cyclotrimer from statistical (1:3) to a more desirable (4.5:1) ratio, in favor of the molecular bowl 1syn. 1H NMR spectroscopic studies suggested the coordinating affinity of 1syn toward transition metals Cu(I), Ag(I), and Au(I), to account for the observed templation effect. In particular, the tridentate 1syn has been shown to bind to one Ag(I) cation in the assembly process that is driven with enthalpy (Delta H degrees = -19 +/- 2 kcal/mol, Delta S degrees = -45 eu). The complete coordination was not cooperative, and was hypothesized to be impeded with the adverse entropy. Accordingly, density functional theory (BP86) calculations of 1syn and its mono-, bis-, and tris-Ag(I) complexes suggested that the coordination of one to three silver cations is highly exothermic. The calculations also revealed that the bowl constriction is necessary for the aromatic arms to become preorganized and bind to a silver cation(s) (Delta E approximately 8 kcal/mol). Ultimately, Ag(I) has been shown to assist the diastereoselective formation of 1syn, lending support to the notion of template-directed synthesis.

  12. National Ocean Sciences Bowl in 2014: A National Competition for High School Ocean Science Education

    DTIC Science & Technology

    2015-03-31

    science volunteers. Coordinate a series of webinars during September-December 2013 that will train 22 Regional Coordinators and discuss best practices...ocean sciences in college, a professional development series for coaches, a video contest open to any high school students and the online quiz game that...3. DATES COVERED (From - To) Feb. 2014-Jan. 2015 4. TITLE AND SUBTITLE National Ocean Sciences Bowl in 2014: A national competition for high

  13. Psychological and psychomotor skills associated with prowess at ten-pin bowling.

    PubMed

    Thomas, P R; Schlinker, P J; Over, R

    1996-06-01

    Psychological and psychomotor skills associated with prowess at ten-pin bowling were identified through factor analysis of ratings provided by 172 bowlers (87 males, 85 females) across a range of current averages (a measure based on recent performance in competition). Skilled bowlers (current average of 170 pins or more) differed significantly from less skilled bowlers (current average of less than 135 pins) on seven component skills. They demonstrated greater mental toughness, a higher degree of planning and evaluation, greater consistency, more interest in improvement, less use of luck attributions, more confidence in equipment and technique, and greater competitiveness. Since men and women of the same overall standard (current average) have similar component skill profiles, ten-pin bowling is a gender-neutral sport. Older bowlers (45-79 years) matched by current average with younger bowlers (16-30 years) differed significantly on only one component, level of commitment. We discuss several contexts for use of the three self-report assessment scales (measures of psychological skills, psychomotor skills and involvement in bowling) developed in this study.

  14. Dust agglomeration

    NASA Technical Reports Server (NTRS)

    2000-01-01

    John Marshall, an investigator at Ames Research Center and a principal investigator in the microgravity fluid physics program, is studying the adhesion and cohesion of particles in order to shed light on how granular systems behave. These systems include everything from giant dust clouds that form planets to tiny compressed pellets, such as the ones you swallow as tablets. This knowledge should help us control the grains, dust, and powders that we encounter or use on a daily basis. Marshall investigated electrostatic charge in microgravity on the first and second U.S. Microgravity Laboratory shuttle missions to see how grains aggregate, or stick together. With gravity's effects eliminated on orbit, Marshall found that the grains of sand that behaved ever so freely on Earth now behaved like flour. They would just glom together in clumps and were quite difficult to disperse. That led to an understanding of the prevalence of the electrostatic forces. The granules wanted to aggregate as little chains, like little hairs, and stack end to end. Some of the chains had 20 or 30 grains. This phenomenon indicated that another force, what Marshall believes to be an electrostatic dipole, was at work.(The diagram on the right emphasizes the aggregating particles in the photo on the left, taken during the USML-2 mission in 1995.)

  15. Interstellar Dust: Contributed Papers

    NASA Technical Reports Server (NTRS)

    Tielens, Alexander G. G. M. (Editor); Allamandola, Louis J. (Editor)

    1989-01-01

    A coherent picture of the dust composition and its physical characteristics in the various phases of the interstellar medium was the central theme. Topics addressed included: dust in diffuse interstellar medium; overidentified infrared emission features; dust in dense clouds; dust in galaxies; optical properties of dust grains; interstellar dust models; interstellar dust and the solar system; dust formation and destruction; UV, visible, and IR observations of interstellar extinction; and quantum-statistical calculations of IR emission from highly vibrationally excited polycyclic aromatic hydrocarbon (PAH) molecules.

  16. [The material character of sand dust and analysis on the cause of formation of the sand-dust storm in northeast district in spring of 2002].

    PubMed

    Jie, Dong-mei; Hu, Ke; Huo, Xin-jiang; Li, Jin; Lü, Jin-fu

    2004-03-01

    The paper analyzed the particle distribution, pollen combination of sand dust storm in northeast district in spring, 2002. It was found that there is abundant pollen, based on pollen combination sand source at new angle can be analyzed, and the distribution laws of the bowling sand and sand dust storm in season, in yearly, in geological periods and mankind historic periods can be explained. The blowing sand and sand dust storm often appeared in geological period and mankind historic period in northeast district, and mainly appeared in winter and in spring and they dropped fluctuationally in fifty years. The frequency of the sand dust storm increased since 2000. The frequency of blowing sand and sand dust storm was controlled by the strength of the monsoon wind in winter. Which the Enino and anti-Enino alternately occurs was influenced by the periodic change of the strength of monsoon wind in winter in Eastern Asia. The cold and dry climate combination in winter and spring was favorable of the occurrence of sand dust weather. The frequency of the sand dust weather will not obviously increase in several years.

  17. The Role of Music in Environmental Education: Lessons from the Cod Fishery Crisis and the Dust Bowl Days.

    ERIC Educational Resources Information Center

    Ramsey, Doug

    2002-01-01

    Uses lyrics and musical styles to illustrate the role of music in educating young people about ecosystem fragility and the cultural importance of rural resources. Describes the east coast fishery prior to and following the announcement of the Northern Cod fishery moratorium in 1992. (Contains 40 references.) (Author/YDS)

  18. US agricultural policy, land use change, and biofuels: are we driving our way to the next dust bowl?

    NASA Astrophysics Data System (ADS)

    Wright, Christopher K.

    2015-05-01

    Lark et al (2015 Environ. Res. Lett. 10 044003), analyze recent shifts in US agricultural land use (2008-2012) using newly-available, high-resolution geospatial information, the Cropland Data Layer. Cropland expansion documented by Lark et al suggests the need to reform national agricultural policies in the wake of an emerging, new era of US agriculture characterized by rapid land cover/land use change.

  19. Meteorological characteristics of dust storm events in the eastern Great Basin of Utah, U.S.A.

    NASA Astrophysics Data System (ADS)

    Hahnenberger, Maura; Nicoll, Kathleen

    2012-12-01

    We assess the mesoscale climatology of dust storm events affecting Salt Lake City, Utah (SLC) since the 1930s, and document the ascendant controls on atmospheric dust generation and transport in the semi-arid Great Basin. Records indicate a seasonal and diurnal pattern, with dust storms typically occurring in spring months during the afternoon. Since 1930, SLC had 379 dust event days (DEDs), averaging 4.7 per year. Air quality station data from populated regions in Utah indicate that dust events produced elevated PM10 exceeding NAAQS on 16 days since 1993, or 0.9 per year. Analysis of DEDs over the period 1948-2010 (n = 331) indicates that approaching mid-level troughs caused 68% of these dust outbreaks and storms. We analyzed two significant DEDs occurring on 19 April 2008 and 4 March 2009, both of which produced elevated particulate matter (PM) levels in the populated region surrounding SLC. Strengthening cyclonic systems are the primary producer of dust outbreaks and storms; the Great Basin Confluence Zone (GBCZ) in the lee of the Sierra Nevada is a known region of cyclogenesis. These cyclonic systems produce strong southwesterly winds in the eastern Great Basin of Utah - termed “hatu winds” - that exceed threshold friction velocities, entrain sediments and loft them into the atmosphere. Plumes identified in MODIS satellite imagery on case study DEDs indicate specific dust source areas, not widespread sediment mobilization. These “hotspots” include playa surfaces at Sevier Dry Lake, Tule Dry Lake, and the Great Salt Lake Desert, as well as Milford Flat, an area burned by Utah's largest wildfire in 2007. The characteristic mountain-valley topography in the Basin & Range physiographic province creates terrain channeling that enhances deflation and funnels dust-bearing winds toward SLC, a growing urban center.

  20. Meteorological and physical characteristics of dust transport events in the Eastern Great Basin of Utah, U.S.A

    NASA Astrophysics Data System (ADS)

    Hahnenberger, M.; Nicoll, K.; Perry, K. D.

    2011-12-01

    Although the Great Basin physiographic province in North America is a known source area of atmospheric dust, the ascendant controls on its dust events have not been well documented to date. We assess the climatology of these dust events back to the 1930s, and find clear seasonal and diurnal patterns, indicating that dust events are, commonly, an afternoon phenomenon during the spring months. Since 1930, Salt Lake City, UT has had 379 dust event days, or 4.7 per year. Air quality station data from the more populated regions of Utah, available since 1993, indicate that dust events have produced elevated PM10, exceeding NAAQS, on 16 days over the past 18 years, or 0.9 per year. This study identifies deepening cyclonic systems over the northern Great Basin as the primary producer of these dust events affecting the eastern Great Basin; this region is located in the lee of the Sierra Nevada, and is a known region of cyclogenesis. Strengthening synoptic scale weather systems interact at the mesoscale with local topography and dust source regions to cause significant dust storms events that have affected the metropolitan area of Salt Lake City, Utah. Upwind of Salt Lake City, these cyclonic systems produce strong southwesterly winds that exceed threshold friction velocities and entrain sediment at the surface of such dust sources as the Sevier Lake, Tule Lake, and Milford Flat, an area disturbed in 2007 by Utah's largest wildfire in recorded history. Case studies of two significant dust events, occurring on 19 April, 2008 and 4 March, 2009, and producing elevated PM10 levels in this region, highlight the key meteorological features and land surface attributes of "hotspot" source areas, identifiable in satellite imagery, of the dust that affected SLC. BSNE dust samplers at the Sevier Lake source region characterize the source type and magnitude and reveal the composition of dust that is being transported. Understanding the meteorological and physical characteristics of

  1. Dust Measurements in Tokamaks

    SciTech Connect

    Rudakov, D; Yu, J; Boedo, J; Hollmann, E; Krasheninnikov, S; Moyer, R; Muller, S; Yu, A; Rosenberg, M; Smirnov, R; West, W; Boivin, R; Bray, B; Brooks, N; Hyatt, A; Wong, C; Fenstermacher, M; Groth, M; Lasnier, C; McLean, A; Stangeby, P; Ratynskaia, S; Roquemore, A; Skinner, C; Solomon, W M

    2008-04-23

    Dust production and accumulation impose safety and operational concerns for ITER. Diagnostics to monitor dust levels in the plasma as well as in-vessel dust inventory are currently being tested in a few tokamaks. Dust accumulation in ITER is likely to occur in hidden areas, e.g. between tiles and under divertor baffles. A novel electrostatic dust detector for monitoring dust in these regions has been developed and tested at PPPL. In DIII-D tokamak dust diagnostics include Mie scattering from Nd:YAG lasers, visible imaging, and spectroscopy. Laser scattering resolves size of particles between 0.16-1.6 {micro}m in diameter; the total dust content in the edge plasmas and trends in the dust production rates within this size range have been established. Individual dust particles are observed by visible imaging using fast-framing cameras, detecting dust particles of a few microns in diameter and larger. Dust velocities and trajectories can be determined in 2D with a single camera or 3D using multiple cameras, but determination of particle size is problematic. In order to calibrate diagnostics and benchmark dust dynamics modeling, pre-characterized carbon dust has been injected into the lower divertor of DIII-D. Injected dust is seen by cameras, and spectroscopic diagnostics observe an increase of carbon atomic, C2 dimer, and thermal continuum emissions from the injected dust. The latter observation can be used in the design of novel dust survey diagnostics.

  2. Dust feed mechanism

    DOEpatents

    Milliman, Edward M.

    1984-01-01

    The invention is a dust feed device for delivery of a uniform supply of dust for long periods of time to an aerosolizing means for production of a dust suspension. The device utilizes at least two tandem containers having spiral brushes within the containers which transport the dust from a supply to the aerosolizer means.

  3. Piston Bowl Optimization for RCCI Combustion in a Light-Duty Multi-Cylinder Engine

    SciTech Connect

    Hanson, Reed M; Curran, Scott; Wagner, Robert M; Reitz, Rolf; Kokjohn, Sage

    2012-01-01

    Reactivity Controlled Compression Ignition (RCCI) is an engine combustion strategy that that produces low NO{sub x} and PM emissions with high thermal efficiency. Previous RCCI research has been investigated in single-cylinder heavy-duty engines. The current study investigates RCCI operation in a light-duty multi-cylinder engine at 3 operating points. These operating points were chosen to cover a range of conditions seen in the US EPA light-duty FTP test. The operating points were chosen by the Ad Hoc working group to simulate operation in the FTP test. The fueling strategy for the engine experiments consisted of in-cylinder fuel blending using port fuel-injection (PFI) of gasoline and early-cycle, direct-injection (DI) of diesel fuel. At these 3 points, the stock engine configuration is compared to operation with both the original equipment manufacturer (OEM) and custom machined pistons designed for RCCI operation. The pistons were designed with assistance from the KIVA 3V computational fluid dynamics (CFD) code. By using a genetic algorithm optimization, in conjunction with KIVA, the piston bowl profile was optimized for dedicated RCCI operation to reduce unburned fuel emissions and piston bowl surface area. By reducing these parameters, the thermal efficiency of the engine was improved while maintaining low NOx and PM emissions. Results show that with the new piston bowl profile and an optimized injection schedule, RCCI brake thermal efficiency was increased from 37%, with the stock EURO IV configuration, to 40% at the 2,600 rev/min, 6.9 bar BMEP condition, and NOx and PM emissions targets were met without the need for exhaust after-treatment.

  4. “Hot Hand” on Strike: Bowling Data Indicates Correlation to Recent Past Results, Not Causality

    PubMed Central

    Yaari, Gur; David, Gil

    2012-01-01

    Recently, the “hot hand” phenomenon regained interest due to the availability and accessibility of large scale data sets from the world of sports. In support of common wisdom and in contrast to the original conclusions of the seminal paper about this phenomenon by Gilovich, Vallone and Tversky in 1985, solid evidences were supplied in favor of the existence of this phenomenon in different kinds of data. This came after almost three decades of ongoing debates whether the “hot hand” phenomenon in sport is real or just a mis-perception of human subjects of completely random patterns present in reality. However, although this phenomenon was shown to exist in different sports data including basketball free throws and bowling strike rates, a somehow deeper question remained unanswered: are these non random patterns results of causal, short term, feedback mechanisms or simply time fluctuations of athletes performance. In this paper, we analyze large amounts of data from the Professional Bowling Association(PBA). We studied the results of the top 100 players in terms of the number of available records (summed into more than 450,000 frames). By using permutation approach and dividing the analysis into different aggregation levels we were able to supply evidence for the existence of the “hot hand” phenomenon in the data, in agreement with previous studies. Moreover, by using this approach, we were able to demonstrate that there are, indeed, significant fluctuations from game to game for the same player but there is no clustering of successes (strikes) and failures (non strikes) within each game. Thus we were lead to the conclusion that bowling results show correlation to recent past results but they are not influenced by them in a causal manner. PMID:22253898

  5. High-explosive cratering analogs for bowl-shaped, central uplift, and multiring impact craters

    NASA Technical Reports Server (NTRS)

    Roddy, D. J.

    1976-01-01

    The paper describes six experimental explosion craters in terms of their basic morphology, subsurface structural deformation, and surrounding ejecta blanket. These craters exhibit one or more of the following features: bowl shapes with underlying breccia lens, central uplifts, multirings, terraced walls, rim strata, zones of concentric rim deformation, inner continuous ground cover of ejecta blankets formed by overturned flaps, secondary cratering, and fused alluvium. These craters were formed by large shock wave energy transfers at or near zero heights-of-burst, and it is possible that impact craters with analogous morphologic and structural features may have formed under similar surface energy transfer conditions.

  6. Temperature dependence of nonlinear optical properties in Li doped nano-carbon bowl material

    NASA Astrophysics Data System (ADS)

    Li, Wei-qi; Zhou, Xin; Chang, Ying; Quan Tian, Wei; Sun, Xiu-Dong

    2013-04-01

    The mechanism for change of nonlinear optical (NLO) properties with temperature is proposed for a nonlinear optical material, Li doped curved nano-carbon bowl. Four stable conformations of Li doped corannulene were located and their electronic properties were investigated in detail. The NLO response of those Li doped conformations varies with relative position of doping agent on the curved carbon surface of corannulene. Conversion among those Li doped conformations, which could be controlled by temperature, changes the NLO response of bulk material. Thus, conformation change of alkali metal doped carbon nano-material with temperature rationalizes the variation of NLO properties of those materials.

  7. A Novel Dust Telescope

    NASA Astrophysics Data System (ADS)

    Grün, E.; Srama, R.; Krüger, H.; Kempf, S.; Harris, D.; Conlon, T.; Auer, S.

    2001-11-01

    Dust particles in space, like photons, are born at remote sites in space and time. From knowledge of the dust particles' birthplace and the particles' bulk properties, we can learn about the remote environment out of which the particles were formed. This approach is carried out by means of a dust telescope on a dust observatory in space. A dust telescope is a combination of a dust trajectory sensor together with a chemical composition analyzer for dust particles. A novel dust telescope is described. It consists of a highly sensitive dust trajectory sensor, and a large area chemical dust analyzer. It can provide valuable information about the particles' birthplace which may not be accessible by other techniques. Dust particles' trajectories are determined by the measurement of the electric signals that are induced when a charged grain flies through an appropriately configured electrode systems. After the successful identification of a few charged micron-sized dust grains in space by the Cassini Cosmic Dust Analyzer, this dust telescope has a ten fold increased sensitivity of charge detection (10-16 Coulombs) and will be able to obtain trajectories for sub-micron sized dust grains. State-of-the art dust chemical analyzers have sufficient mass resolution to resolve ions with atomic mass numbers above 100. However, since their impact areas are small they can analyze statistically meaningful numbers of grains only in the dust-rich environments of comets or ringed planets. Therefore, this dust telescope includes a large area (0.1 m2) chemical dust analyzer of mass resolution > 100 that will allow us to obtain statistically significant measurements of interplanetary and interstellar dust grains in space.

  8. Dust Avalanches

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    Crater wall dust avalanches in southern Arabia Terra.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

    Image information: VIS instrument. Latitude 10.3, Longitude 24.5 East (335.5 West). 19 meter/pixel resolution.

  9. 2D-ordered dielectric sub-micron bowls on a metal surface: a useful hybrid plasmonic-photonic structure

    NASA Astrophysics Data System (ADS)

    Lan, Yue; Wang, Shiqiang; Yin, Xianpeng; Liang, Yun; Dong, Hao; Gao, Ning; Li, Jian; Wang, Hui; Li, Guangtao

    2016-07-01

    Recently, it has been demonstrated that the combination of periodic dielectric structures with metallic structures provides an efficient means to yield a synergetic optical response or functionality in the resultant hybrid plasmonic-photonic systems. In this work, a new hybrid plasmonic-photonic structure of 2D-ordered dielectric sub-micron bowls on a flat gold surface was proposed, prepared, and theoretically and experimentally characterized. This hybrid structure supports two types of modes: surface plasmon polaritons bound at the metallic surface and waveguided mode of light confined in the cavity of bowls. Optical responses of this hybrid structure as well as the spatial electric field distribution of each mode are found to be strongly dependent on the structural parameters of this system, and thus could be widely modified on demand. Importantly, compared to the widely studied hybrid systems, namely the flat metallic surface coated with a monolayer array of latex spheres, the waveguided mode with strong field enhancement appearing in the cavities of bowls is more facilely accessible and thus suitable for practical use. For demonstration, a 2D-ordered silica sub-micron bowl array deposited on a flat gold surface was fabricated and used as a regenerable platform for fluorescence enhancement by simply accommodating emitters in bowls. All the simulation and experiment results indicate that the 2D-ordered dielectric sub-micron bowls on a metal surface should be a useful hybrid plasmonic-photonic system with great potential for applications such as sensors or tunable emitting devices if appropriate periods and materials are employed.Recently, it has been demonstrated that the combination of periodic dielectric structures with metallic structures provides an efficient means to yield a synergetic optical response or functionality in the resultant hybrid plasmonic-photonic systems. In this work, a new hybrid plasmonic-photonic structure of 2D-ordered dielectric sub

  10. Climate change and climate systems influence and control the atmospheric dispersion of desert dust: implications for human health

    USGS Publications Warehouse

    Griffin, Dale W.; Ragaini, Richard C.

    2010-01-01

    The global dispersion of desert dust through Earth’s atmosphere is greatly influenced by temperature. Temporal analyses of ice core data have demonstrated that enhanced dust dispersion occurs during glacial events. This is due to an increase in ice cover, which results in an increase in drier terrestrial cover. A shorter temporal analysis of dust dispersion data over the last 40 years has demonstrated an increase in dust transport. Climate systems or events such as the North Atlantic Oscillation, the Indian Ocean subtropical High, Pacific Decadal Oscillation, and El Nino-Sothern Oscillation are known to influence global short-term dust dispersion occurrence and transport routes. Anthropogenic influences on dust transport include deforestation, harmful use of topsoil for agriculture as observed during the American Dust Bowl period, and the creation of dry seas (Aral Sea) and lakes (Lake Owens in California and Lake Chad in North Africa) through the diversion of source waters (for irrigation and drinking water supplies). Constituents of desert dust both from source regions (pathogenic microorganisms, organic and inorganic toxins) and those scavenged through atmospheric transport (i.e., industrial and agricultural emissions) are known to directly impact human and ecosystem health. This presentation will present a review of global scale dust storms and how these events can be both a detriment and benefit to various organisms in downwind environments.

  11. Dust particle dynamics in atmospheric dust devils

    NASA Astrophysics Data System (ADS)

    Izvekova, Yulia; Popel, Sergey

    2016-04-01

    Dust particle dynamics is modeled in the Dust Devils (DDs). DD is a strong, well-formed, and relatively long-lived whirlwind, ranging from small (half a meter wide and a few meters tall) to large (more than 100 meters wide and more than 1000 meters tall) in Earth's atmosphere. We develop methods for the description of dust particle charging in DDs, discuss the ionization processes in DDs, and model charged dust particle motion. Our conclusions are consistent with the fact that DD can lift a big amount of dust from the surface of a planet into its atmosphere. On the basis of the model we perform calculations and show that DDs are important mechanism for dust uplift in the atmospheres of Earth and Mars. Influence of DD electric field on dynamics of dust particles is investigated. It is shown that influence of the electric field on dust particles trajectories is significant near the ground. At some altitude (more then a quarter of the height of DD) influence of the electric field on dust particles trajectories is negligible. For the calculation of the dynamics of dust electric field can be approximated by effective dipole located at a half of the height of DD. This work was supported by the Russian Federation Presidential Program for State Support of Young Scientists (project no. MK-6935.2015.2).

  12. An ancient Roman bowl embedded in a soil sample: surface shaded three dimensional display using data from a multi-detector CT.

    PubMed

    De Maeseneer, M; Buls, N; Cleeren, N; Lenchik, L; De Mey, J

    2006-01-01

    We present an unusual application of multidetector CT and shaded surface rendering in the investigation of a soil sample, containing an ancient Roman bronze bowl. The CT findings were of fundamental importance in helping the archaeologists study the bronze bowl from the soil sample.

  13. Isolation and characterization of an early colonizing Rhizobium sp. R8 from a household toilet bowl.

    PubMed

    Fukano, Toru; Gomi, Mitsuhiro; Osaki, Yukihiko; Morikawa, Masaaki

    2015-01-01

    The bacterial community structure was compared between the third days', one week', and three weeks' biofilm samples from the surface of a household toilet bowl. It was found that the PCR-DGGE band pattern of 16S rRNA gene was dramatically changed after the third day and was not further changed until three weeks. This result suggests that there are early and late colonizing bacterial groups. One of the early colonizers isolated from the third days' sample was Rhizobium sp. R8, a closest relative to Rhizobium giardinii, which exhibited the highest biofilm formation activity in an artificial urine condition. R8 produced extracellular polysaccharides containing galactose, glucose, and mannose at the molar ratio of 8:1:1, which were probably responsible for the biofilm formation. Its excelled biofilm formation and urease activities together with the lack of nodulation and nitrogen fixing genes in R8 suggest that this strain has been specifically adapted to urine condition in a toilet bowl.

  14. A unified framework for producing CAI melting, Wark-Lovering rims and bowl-shaped CAIs

    NASA Astrophysics Data System (ADS)

    Liffman, Kurt; Cuello, Nicolas; Paterson, David A.

    2016-10-01

    Calcium-Aluminium inclusions (CAIs) formed in the Solar system, some 4567 million years ago. CAIs are almost always surrounded by Wark-Lovering rims (WLRs), which are a sequence of thin, mono/bi-mineralic layers of refractory minerals, with a total thickness in the range of 1-100 microns. Recently, some CAIs have been found that have tektite-like bowl-shapes. To form such shapes, the CAI must have travelled through a rarefied gas at hypersonic speeds. We show how CAIs may have been ejected from the inner solar accretion disc via the centrifugal interaction between the solar magnetosphere and the inner disc rim. They subsequently punched through the hot, inner disc rim wall at hypersonic speeds. This re-entry heating partially or completely evaporated the CAIs. Such evaporation could have significantly increased the metal abundances of the inner disc rim. High speed movement through the inner disc produced WLRs. To match the observed thickness of WLRs required metal abundances at the inner disc wall that are of order 10 times that of standard solar abundances. The CAIs cooled as they moved away from the protosun, the deduced CAI cooling rates are consistent with the CAI cooling rates obtained from experiment and observation. The speeds and gas densities required to form bowl-shaped CAIs are also consistent with the expected speeds and gas densities for larger, ˜1 cm, CAIs punching through an inner accretion disc wall.

  15. [The influence of Nintendo-Wii® bowling upon residents of retirement homes].

    PubMed

    Wittelsberger, R; Krug, S; Tittlbach, S; Bös, K

    2013-07-01

    The few studies dealing with the positive effects of health and well-being of older people are only one-sided. The aim of the study therefore was to analyze the effects of Nintendo-Wii® bowling on daily function, state of dementia, quality of life, cognition and motor skills in retirement home inhabitants. The study was performed with 27 study participants (13 women, 14 men) between the ages of 49 and 95 years (mean = 71, SD = 14). They were randomly assigned to a control group (KG) and an intervention group (IG). Between pre- and posttest, the IG played 60 min/twice a week Nintendo-Wii® Bowling over 6 weeks. The improvement of IG was significant in the analysis of variance concerning strength (arm curls: F df = 2 = 7.199; p = 0,013; η(2) = 0,231) and showed a significant trend concerning coordination (tracking lines: F df = 2 = 3.99; p = 0,058; η(2) = 0,154) compared with KG. The area of rapidity (catching bars: F df = 2 = 28.511; p = 0,008; η(2) = 0,279) showed a significant decline in the IG compared with the KG. However, closer examination shows that the short time of intervention and the wide age range could have affected the results. Thus, further studies should take these critical aspects into consideration.

  16. Thermo-responsive cross-linked liquid crystal bowl-shaped colloids

    NASA Astrophysics Data System (ADS)

    Wei, Wei-Shao; Xia, Yu; Yang, Shu; Yodh, A. G.

    In this work we create and investigate cross-linked bowl-shaped nematic liquid crystal (NLC) colloidal particles. Janus colloids are first formed via solvent-induced phase separation in emulsions consisting of NLC monomers and isotropic polymers. This scheme enables us to realize different particle morphologies such as bowl-shape by fine-tuning the confinement of NLCs within the droplets, e.g. by varying the size of droplets, the volume ratio between NLC and polymer, and the type/concentration of surfactants in aqueous background phase. The NLC compartment is composed of RM82 (1,4-Bis-[4-(6-acryloyloxyhexyloxy)benzoyloxy]-2-methylbenzene) monomers, which are then photocrosslinked by dithiol groups to form nematic liquid crystal elastomer. Finally, we remove the polymer parts of Janus colloids to obtain the target structures, which are temperature sensitive due to change of elasticity and molecular alignment of NLC near the isotropic to nematic phase transition temperature. We will explore novel mechanical and optical properties from the thermo-responsive structures as well as their applications, such as biomimic swimming behaviors and adjustable lensing effects. This work is supported by the foundation through NSF Grant DMR12-05463, NSF-MRSEC Grant DMR11-20901, and NASA Grant NNX08AO0G.

  17. Iron fertilisation by Asian dust influences North Pacific sardine regime shifts

    NASA Astrophysics Data System (ADS)

    Qiu, Yongsong

    2015-05-01

    Forcing factors and mechanisms underlying multidecadal variability in the production of the world's major fish stocks are one of the great mysteries of the oceans. The Japanese and California sardine are species that exhibit the regime shifts. It is shown in the present work that during two periods of frequent Asian dust events over the last 100 years, sardines on opposite sides of the Pacific Ocean only flourished under a dust-active regime. The earlier such regime that peaked in the 1930s was strong, and it brought synchronous changes in the two species that were linked to the frequency of Asian dust events. However, there is an apparent mismatch in the rise and fall of abundance between the two species in the current dust-active regime. The massive increase in Japanese sardine stock in the 1970s was related to high levels of ocean precipitation and strong winter mixing, whereas the stock collapse since 1988 has been attributed to diminished winter mixing. High levels of ocean precipitation in the western North Pacific effectively cause wet deposition of Asian dust and enhance Japanese sardine stock, whereas it reduces dust flux that can be transported to the eastern North Pacific, delaying the increase of California sardine stock. Analysis further indicates that productivity of Japanese sardine stock is jointly controlled by wet deposition of Asian dust and winter mixing, which supplies macronutrients from depth. California sardine productivity is inversely related to precipitation in the western North Pacific and is positively affected by precipitation off western North America. This indicates that Asian dust influx dominates productivity of the species because of iron-limited ocean productivity in the California sardine ranges. The analysis suggests that dust regime shifts influence shifts in sardine productivity regimes and that iron input from Asian dust during trans-Pacific transport is directly responsible. It appears that in addition to enhancing

  18. Wind tunnel study of twelve dust samples by large particle size

    NASA Astrophysics Data System (ADS)

    Shannak, B.; Corsmeier, U.; Kottmeier, Ch.; Al-azab, T.

    2014-12-01

    Due to the lack of data by large dust and sand particle, the fluid dynamics characteristics, hence the collection efficiencies of different twelve dust samplers have been experimentally investigated. Wind tunnel tests were carried out at wind velocities ranging from 1 up to 5.5 ms-1. As a large solid particle of 0.5 and 1 mm in diameter, Polystyrene pellets called STYRO Beads or polystyrene sphere were used instead of sand or dust. The results demonstrate that the collection efficiency is relatively acceptable only of eight tested sampler and lie between 60 and 80% depending on the wind velocity and particle size. These samplers are: the Cox Sand Catcher (CSC), the British Standard Directional Dust Gauge (BSD), the Big Spring Number Eight (BSNE), the Suspended Sediment Trap (SUSTRA), the Modified Wilson and Cooke (MWAC), the Wedge Dust Flux Gauge (WDFG), the Model Series Number 680 (SIERRA) and the Pollet Catcher (POLCA). Generally they can be slightly recommended as suitable dust samplers but with collecting error of 20 up to 40%. However the BSNE verify the best performance with a catching error of about 20% and can be with caution selected as a suitable dust sampler. Quite the contrary, the other four tested samplers which are the Marble Dust Collector (MDCO), the United States Geological Survey (USGS), the Inverted Frisbee Sampler (IFS) and the Inverted Frisbee Shaped Collecting Bowl (IFSCB) cannot be recommended due to their very low collection efficiency of 5 up to 40%. In total the efficiency of sampler may be below 0.5, depending on the frictional losses (caused by the sampler geometry) in the fluid and the particle's motion, and on the intensity of airflow acceleration near the sampler inlet. Therefore, the literature data of dust are defective and insufficient. To avoid false collecting data and hence inaccurate mass flux modeling, the geometry of the dust sampler should be considered and furthermore improved.

  19. Dust Plume off Mauritania

    NASA Technical Reports Server (NTRS)

    2007-01-01

    A thick plume of dust blew off the coast of Mauritania in western Africa on October 2, 2007. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite observed the dust plume as it headed toward the southwest over the Atlantic Ocean. In this image, the dust varies in color from nearly white to medium tan. The dust plume is easier to see over the dark background of the ocean, but the plume stretches across the land surface to the east, as well. The dust plume's structure is clearest along the coastline, where relatively clear air pockets separate distinct puffs of dust. West of that, individual pillows of dust push together to form a more homogeneous plume. Near its southwest tip, the plume takes on yet another shape, with stripes of pale dust fanning out toward the northwest. Occasional tiny white clouds dot the sky overhead, but skies are otherwise clear.

  20. Ab initio calculation of bowl, cage, and ring isomers of C20 and C20-.

    PubMed

    An, Wei; Gao, Yi; Bulusu, Satya; Zeng, X C

    2005-05-22

    High-level ab initio calculations have been carried out to reexamine relative stability of bowl, cage, and ring isomers of C(20) and C(20)(-). The total electronic energies of the three isomers show different energy orderings, strongly depending on the hybrid functionals selected. It is found that among three popular hybrid density-functional (DF) methods B3LYP, B3PW91, PBE1PBE, and a new hybrid-meta-DF method TPSSKCIS, only the PBE1PBE method (with cc-pVTZ basis set) gives qualitatively correct energy ordering as that predicted from ab initio CCSD(T)/cc-pVDZ [CCSD(T)-coupled-cluster method including singles, doubles, and noniterative perturbative triples; cc-pVDZ-correlation consistent polarized valence double zeta] as well as from MP4(SDQ)/cc-pVTZ [MP4-fourth-order Moller-Plesset; cc-pVTZ-correlation consistent polarized valence triple zeta] calculations. Both CCSD(T) and MP4 calculations indicate that the bowl is most likely the global minimum of neutral C(20) isomers, followed by the fullerene cage and ring. For the anionic counterparts, the PBE1PBE calculation also agrees with MP4/cc-pVTZ calculation, both predicting that the bowl is still the lowest-energy structure of C(20)(-) at T=0 K, followed by the ring and the cage. In contrast, both B3LYP/cc-pVTZ and B3PW91/cc-pVTZ calculations predict that the ring is the lowest-energy structure of C(20)(-). Apparently, this good reliability in predicting the energy ordering renders the hybrid PBE method a leading choice for predicting relative stability among large-sized carbon clusters and other carbon nanostructures (e.g., finite-size carbon nanotubes, nano-onions, or nanohorns). The relative stabilities derived from total energy with Gibbs free-energy corrections demonstrate a changing ordering in which ring becomes more favorable for both C(20) and C(20)(-) at high temperatures. Finally, photoelectron spectra (PES) for the anionic C(20)(-) isomers have been computed. With binding energies up to 7 eV, the

  1. The effect of spin in swing bowling in cricket: model trajectories for spin alone

    NASA Astrophysics Data System (ADS)

    Robinson, Garry; Robinson, Ian

    2015-02-01

    In ‘swing’ bowling, as employed by fast and fast-medium bowlers in cricket, back-spin along the line of the seam is normally applied in order to keep the seam vertical and to provide stability against ‘wobble’ of the seam. Whilst spin is normally thought of as primarily being the slow bowler's domain, the spin applied by the swing bowler has the side-effect of generating a lift or Magnus force. This force, depending on the orientation of the seam and hence that of the back-spin, can have a side-ways component as well as the expected vertical ‘lift’ component. The effect of the spin itself, in influencing the trajectory of the fast bowler's delivery, is normally not considered, presumably being thought of as negligible. The purpose of this paper is to investigate, using calculated model trajectories, the amount of side-ways movement due to the spin and to see how this predicted movement compares with the total observed side-ways movement. The size of the vertical lift component is also estimated. It is found that, although the spin is an essential part of the successful swing bowler's delivery, the amount of side-ways movement due to the spin itself amounts to a few centimetres or so, and is therefore small, but perhaps not negligible, compared to the total amount of side-ways movement observed. The spin does, however, provide a considerable amount of lift compared to the equivalent delivery bowled without spin, altering the point of pitching by up to 3 m, a very large amount indeed. Thus, for example, bowling a ball with the seam pointing directly down the pitch and not designed to swing side-ways at all, but with the amount of back-spin varied, could provide a very powerful additional weapon in the fast bowler's arsenal. So-called ‘sling bowlers’, who use a very low arm action, can take advantage of spin since effectively they can apply side-spin to the ball, giving rise to a large side-ways movement, ˜ 20{}^\\circ cm or more, which certainly is

  2. Synthesis and STM imaging of symmetric and dissymmetric ethynyl-bridged dimers of boron-subphthalocyanine bowl-shaped nanowheels.

    PubMed

    Jacquot de Rouville, Henri-Pierre; Garbage, Romain; Ample, Francisco; Nickel, Anja; Meyer, Joerg; Moresco, Francesca; Joachim, Christian; Rapenne, Gwénaël

    2012-07-16

    The future's wheel: A new class of wheels, based on subphthalocyanine fragments, for future incorporation in functional nanovehicles is reported (see figure). The syntheses of a symmetric wheel, a nitrogen-tagged wheel, and their ethynyl-bridged homodimers are presented. Theoretical calculations and STM imaging demonstrate the advantage of a bowl-shaped structure and the efficiency of the tag for STM imaging.

  3. Socialist Revolution: Samuel Bowles, Herbert Gintis, and the Emergence of Marxist Thought in the Field of Education

    ERIC Educational Resources Information Center

    Gottesman, Isaac

    2013-01-01

    Upon its publication in 1976, Samuel Bowles and Herbert Gintis' "Schooling in Capitalist America" was the most sophisticated and nuanced Marxian social and political analysis of schooling in the United States. Thirty-five years after its publication, "Schooling" continues to have a strong impact on thinking about education. Despite its…

  4. Three-dimensional æolian dynamics within a bowl blowout during offshore winds: Greenwich Dunes, Prince Edward Island, Canada

    NASA Astrophysics Data System (ADS)

    Hesp, Patrick A.; Walker, Ian J.

    2012-01-01

    This paper examines the æolian dynamics of a deep bowl blowout within the foredune of the Greenwich Dunes, on the northeastern shore or Prince Edward Island, Canada. Masts of cup anemometers and sonic anemometers were utilized to measure flow velocities and directions during a strong regional ESE (offshore) wind event. The flow across the blowout immediately separated at the upwind rim crest, and within the blowout was strongly reversed. High, negative vertical flows occurred down the downwind (but seaward) vertical scarp which projected into the separation envelope and topographically forced flow back into the blowout. A pronounced, accelerated jet flow existed near the surface across the blowout basin, and the flow exhibited a complex, anti-clockwise structure with the near-surface flow following the contours around the blowout basin and lower slopes. Significant æolian sediment transport occurred across the whole bowl basin and sediment was delivered by saltation and suspension out the blowout to the east. This study demonstrates that strong offshore winds produce pronounced topographically forced flow steering, separation, reversal, and more complex three-dimensional motions within a bowl blowout, and that such winds within a bowl blowout play a notable role in transporting sediment within and beyond deep topographic hollows in the foredune.

  5. Facile synthesis of novel bowl-like hollow carbon spheres by the combination of hydrothermal carbonization and soft templating.

    PubMed

    Zhang, Zili; Qin, Mingli; Jia, Baorui; Zhang, Hongzhou; Wu, Haoyang; Qu, Xuanhui

    2017-03-07

    For the first time, bowl-like hollow carbon spheres (BHCSs) have been designed and fabricated by the combination of hydrothermal carbonization and soft templating. The obtained BHCSs exhibit well-defined shapes with the size ranging from 1 to 2 μm. As electrodes of electrochemical double layer capacitors they showed good performance.

  6. Online Responses to a Multilingual Super Bowl Ad: Is "America the Beautiful" by Any Other Language Still America, the Beautiful?

    ERIC Educational Resources Information Center

    Hoffman, Brooke Y.

    2016-01-01

    On 2 February 2014, an advertisement entitled "It's Beautiful" debuted during Super Bowl XLVIII, which was watched by 111.5 million people in the USA. The Coca-Cola advertisement portrayed people of various ethnicities and was accompanied by "America the Beautiful" sung in nine languages. Using critical discourse analysis, I…

  7. Transition metal-boron complexes BnM: from bowls (n = 8-14) to tires (n = 14).

    PubMed

    Li, Si-Dian; Miao, Chang-Qing; Guo, Jin-Chang; Ren, Guang-Ming

    2006-11-30

    Transition metal-boron complexes BnM have been predicted at density functional theory level to be molecular bowls (n = 8-14) hosting a transition metal atom (M) inside or molecular tires (n = 14) centered with a transition metal atom. Small Bn clusters prove to be effective inorganic ligands to all the VB-VIIIB transition metal elements in the periodic table. Density functional evidences obtained in this work strongly suggest that bowl-shaped fullerene analogues of Bn units exist in small BnM complexes and the bowl-to-tire structural transition occur to the first-row transition metal complexes BnM (M = Mn, Fe, Co) at n = 14, a size obviously smaller than n = 20 where the 2D-3D structural transition occurs to bare Bn. The half-sandwich-type B12Cr (C3v), full sandwich-type (B12)2Cr (D3d), bowl-shaped B14Fe (C2), and tire-shaped B14Fe (D7d) and B14Fe- (C7v) are the most interesting prototypes to be targeted in future experiments. These BnM complexes may serve as building blocks to form extended boron-rich BnMm tubes or cages (m > or = 2) or as structural units to be placed inside carbon nanotubes with suitable diameters.

  8. Capture of Cometary Dust Grains in Impacts at 6.1 km s-1

    NASA Astrophysics Data System (ADS)

    Burchell, M. J.; Foster, N.; Kearsley, A.; Wozniakiewicz, P.

    2009-12-01

    The NASA Stardust mission to comet 81P/Wild 2 collected grains of cometary dust freshly ejected from the comet during a fly-by at a speed of 6.1 km s-1. These were captured on aluminum foils and in blocks of silica aerogel. The dust underwent a severe shock during capture. The nature of the shock process depends on the properties of the dust and the collecting media. On the aluminium, the shock process and impact damage is typical of that between high-density (or hard materials) at high velocity, resulting in craters lined with impactor residues. The peak shock pressures are estimated at 60-80 GPa. Two main crater types are seen, simple bowl shaped and multiple pit craters: these reflect the degree of consolidation of the original dust grain. Capture in the low density aerogel was via a more gradual slowing of the dust grains accompanied by a variety of effects on the grains (complete break up of weak grains vs. ablation of well consolidated grains). The relation between the structure of the dust grains and the resulting impact features in both collector materials is discussed.

  9. Niamey Dust Observations

    DOE Data Explorer

    Flynn, Connor

    2008-10-01

    Niamey aerosol are composed of two main components: dust due to the proximity of the Sahara Desert, and soot from local and regional biomass burning. The purpose of this data product is to identify when the local conditions are dominated by the dust component so that the properties of the dust events can be further studied.

  10. China Dust and Sand

    Atmospheric Science Data Center

    2013-04-16

    article title:  Dust and Sand Sweep Over Northeast China     ... (MISR) captured these views of the dust and sand that swept over northeast China on March 10, 2004. Information on the ... available at JPL March 10, 2004 - Dust and sand sweep the northeast region. project:  MISR ...

  11. Dust in the Universe

    ERIC Educational Resources Information Center

    Hemenway, Mary Kay; Armosky, Brad J.

    2004-01-01

    Space is seeming less and less like empty space as new discoveries and reexaminations fill in the gaps. And, ingenuity and technology, like the Spitzer Space Telescope, is allowing examination of the far reaches of the Milky Way and beyond. Even dust is getting its due, but not the dust everyone is familiar with. People seldom consider the dust in…

  12. Middle East Dust

    Atmospheric Science Data Center

    2013-04-16

    ... only some of the dust over eastern Syria and southeastern Turkey can be discerned. The dust is much more obvious in the center panel, ... 18, 2002 - A large dust plume extends across Syria and Turkey. project:  MISR category:  gallery ...

  13. The Role of Obliteration in the Achievement of a Dry Mastoid Bowl

    PubMed Central

    Harun, Aisha; Clark, James; Semenov, Yevgeniy R.; Francis, Howard W.

    2016-01-01

    Objective To evaluate the impact of mastoid obliteration on the achievement of a dry mastoid bowl and frequency of maintenance care. Study Design Retrospective chart review. Setting Academic medical center. Patients There were 63 canal-wall-down mastoidectomies for chronic otitis media with or without cholesteatoma between 2007 and 2014 with follow-up of at least 6 months. Eighteen mastoids were nonobliterated and 45 were obliterated. Thirteen underwent secondary obliteration of existing mastoid bowls with chronic drainage, whereas 32 underwent primary obliteration at the original canal-wall-down procedure. Intervention Mastoid obliteration. Main Outcome Measures Achievement of a dry healed mastoid cavity and frequency of outpatient visits. Results In more than 80% of the cases, a dry ear was achieved, with no significant difference between the obliterated and nonobliterated cases (p = 0.786). Eleven of the 13 secondary cases experienced cessation of otorrhea, achieving dry ears at rates similar to that of the primary and nonobliterated cases. The secondary obliteration population was also significantly younger than the primary group (22.1 versus 43.5 years, p = 0.002). Multivariable-mixed effects analysis demonstrated a reduction in 0.1 visits per 6-month period following surgery overtime (p < 0.001). Conclusions Mastoid obliteration may be valuable in the management of the well-developed and chronically wet mastoid cavity, particularly when the drainage emanates from mucosal disease or cell tracts in a deep sinodural angle. Younger patients may require secondary obliteration because of continued craniofacial maturation several years following canal-wall-down surgery. PMID:26375974

  14. Dust and Planetary Rings

    NASA Astrophysics Data System (ADS)

    Siddiqui, Muddassir

    ABSTRACT Space is not empty it has comic radiations (CMBR), dust etc. Cosmic dust is that type of dust which is composed of particles in space which vary from few molecules to 0.1micro metres in size. This type of dust is made up of heavier atoms born in the heart of stars and supernova. Mainly it contains dust grains and when these dust grains starts compacting then it turns to dense clouds, planetary ring dust and circumstellar dust. Dust grains are mainly silicate particles. Dust plays a major role in our solar system, for example in zodiacal light, Saturn's B ring spokes, planetary rings at Jovian planets and comets. Observations and measurements of cosmic dust in different regions of universe provide an important insight into the Universe's recycling processes. Astronomers consider dust in its most recycled state. Cosmic dust have radiative properties by which they can be detected. Cosmic dusts are classified as intergalactic dusts, interstellar dusts and planetary rings. A planetary ring is a ring of cosmic dust and other small particles orbiting around a planet in flat disc shape. All of the Jovian planets in our solar system have rings. But the most notable one is the Saturn's ring which is the brightest one. In March 2008 a report suggested that the Saturn's moon Rhea may have its own tenuous ring system. The ring swirling around Saturn consists of chunks of ice and dust. Most rings were thought to be unstable and to dissipate over course of tens or hundreds of millions of years but it now appears that Saturn's rings might be older than that. The dust particles in the ring collide with each other and are subjected to forces other than gravity of its own planet. Such collisions and extra forces tend to spread out the rings. Pluto is not known to have any ring system but some Astronomers believe that New Horizons probe might find a ring system when it visits in 2015.It is also predicted that Phobos, a moon of Mars will break up and form into a planetary ring

  15. Dust in galaxy clusters

    NASA Astrophysics Data System (ADS)

    Polikarpova, O. L.; Shchekinov, Yu. A.

    2017-02-01

    The conditions for the destruction of dust in hot gas in galaxy clusters are investigated. It is argued that extinction measurements can be subject to selection effects, hindering their use in obtaining trustworthy estimates of dust masses in clusters. It is shown, in particular, that the ratio of the dust mass to the extinction M d / S d increases as dust grains are disrupted, due to the rapid destruction of small grains. Over long times, this ratio can asymptotically reach values a factor of three higher than the mean value in the interstellar medium in the Galaxy. This lowers dust-mass estimates based on measurements of extinction in galaxy clusters. The characteristic lifetime of dust in hot cluster gas is determined by its possible thermal isolation by the denser medium of gas fragments within which the dust is ejected from galaxies, and can reach 100-300 million years, depending on the kinematics and morphology of the fragments. As a result, the mass fraction of dust in hot cluster gas can reach 1-3% of the Galactic value. Over its lifetime, dust can also be manifest through its far-infrared emission. The emission characteristics of the dust change as it is disrupted, and the ratio of the fluxes at 350 and 850 μm can increase appreciably. This can potentially serve as an indicator of the state of the dust and ambient gas.

  16. Interstellar Dust - A Review

    NASA Technical Reports Server (NTRS)

    Salama, Farid

    2012-01-01

    The study of the formation and the destruction processes of cosmic dust is essential to understand and to quantify the budget of extraterrestrial organic materials. Although dust with all its components plays an important role in the evolution of interstellar physics and chemistry and in the formation of organic materials, little is known on the formation and destruction processes of carbonaceous dust. Laboratory experiments that are performed under conditions that simulate interstellar and circumstellar environments to provide information on the nature, the size and the structure of interstellar dust particles, the growth and the destruction processes of interstellar dust and the resulting budget of extraterrestrial organic molecules. A review of the properties of dust and of the laboratory experiments that are conducted to study the formation processes of dust grains from molecular precursors will be given.

  17. Light Dust Devil Tracks

    NASA Technical Reports Server (NTRS)

    2004-01-01

    14 October 2004 Many Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) images exhibit wild patterns of dark streaks thought to have formed by the passage of many dust devils. The dust devils disrupt the dust coating the martian surface, leaving behind a streak. However, not all dust devils make streaks, and not all dust devil streaks are dark. Some are light---it simply depends upon which is darker, the substrate or the dust that the spinning vortex disrupts. The example of light-toned dust devil streaks shown here is located in southern Schiaparelli Basin near 5.3oS, 343.3oW. The image covers an area about 3 km (1.9 mi) across; sunlight illuminates the scene from the left/upper left.

  18. Bench-scale testing of DOE/PETC`s GranuFlow Process for fine coal dewatering and handling. 1: Results using a high-gravity solid-bowl centrifuge

    SciTech Connect

    Wen, W.W.; Killmeyer, R.P.; Lowman, R.H.; Elstrodt, R.

    1995-12-31

    Most advanced fine-coal cleaning processes involve the use of water. Utility companies are concerned not only with the lower Btu content of the resulting wet, cleaned coal, but more importantly with its handleability problems. Solutions to these problems would enhance the utilization of fine-coal cleaning processes in the utility industry. This paper describes testing of the GranuFlow Process, developed and patented by the Pittsburgh Energy Technology Center (PETC) of the US Department of Energy, using a high-gravity solid bowl centrifuge for dewatering and reconstitution of fine-cleaned-coal slurry at 300 lb per hour in PETC`s Coal Preparation Process Research Facility. Fine-cleaned-coal slurry was treated with a bitumen emulsion before dewatering in a high-gravity solid-bowl centrifuge. The treated products appeared to be dry and in a free-flowing granular form, while the untreated products were wet, lumpy, sticky, and difficult to handle. Specifically, test results indicated that the moisture content, handleability, and dust reduction of the dewatered coal product improved as the addition of emulsion increased from 2% to 8%. The improvement in handleability was most visible for the 200 mesh (75 micron) x 0 coal, when compared with 150 mesh (106 micron) x 0, 65 mesh (212 micron) x 0 or 28 mesh (600 micron) x 0 coals. Test results also showed that the moisture content was dramatically reduced (26--37% reduction) for the four different sizes of coals at 6 or 8% emulsion addition. Because of the moisture reduction and the granular form of the product, the freezing problem was also alleviated.

  19. The Lunar Dust Environment

    NASA Astrophysics Data System (ADS)

    Szalay, Jamey Robert

    Planetary bodies throughout the solar system are continually bombarded by dust particles, largely originating from cometary activities and asteroidal collisions. Surfaces of bodies with thick atmospheres, such as Venus, Earth, Mars and Titan are mostly protected from incoming dust impacts as these particles ablate in their atmospheres as 'shooting stars'. However, the majority of bodies in the solar system have no appreciable atmosphere and their surfaces are directly exposed to the flux of high speed dust grains. Impacts onto solid surfaces in space generate charged and neutral gas clouds, as well as solid secondary ejecta dust particles. Gravitationally bound ejecta clouds forming dust exospheres were recognized by in situ dust instruments around the icy moons of Jupiter and Saturn, and had not yet been observed near bodies with refractory regolith surfaces before NASA's Lunar Dust and Environment Explorer (LADEE) mission. In this thesis, we first present the measurements taken by the Lunar Dust Explorer (LDEX), aboard LADEE, which discovered a permanently present, asymmetric dust cloud surrounding the Moon. The global characteristics of the lunar dust cloud are discussed as a function of a variety of variables such as altitude, solar longitude, local time, and lunar phase. These results are compared with models for lunar dust cloud generation. Second, we present an analysis of the groupings of impacts measured by LDEX, which represent detections of dense ejecta plumes above the lunar surface. These measurements are put in the context of understanding the response of the lunar surface to meteoroid bombardment and how to use other airless bodies in the solar system as detectors for their local meteoroid environment. Third, we present the first in-situ dust measurements taken over the lunar sunrise terminator. Having found no excess of small grains in this region, we discuss its implications for the putative population of electrostatically lofted dust.

  20. Reducing float coal dust

    PubMed Central

    Patts, J.R.; Colinet, J.F.; Janisko, S.J.; Barone, T.L.; Patts, L.D.

    2016-01-01

    Controlling float coal dust in underground coal mines before dispersal into the general airstream can reduce the risk of mine explosions while potentially achieving a more effective and efficient use of rock dust. A prototype flooded-bed scrubber was evaluated for float coal dust control in the return of a continuous miner section. The scrubber was installed inline between the face ventilation tubing and an exhausting auxiliary fan. Airborne and deposited dust mass measurements were collected over three days at set distances from the fan exhaust to assess changes in float coal dust levels in the return due to operation of the scrubber. Mass-based measurements were collected on a per-cut basis and normalized on the basis of per ton mined by the continuous miner. The results show that average float coal dust levels measured under baseline conditions were reduced by more than 90 percent when operating the scrubber. PMID:28018004

  1. DUST FORMATION IN MACRONOVAE

    SciTech Connect

    Takami, Hajime; Ioka, Kunihito; Nozawa, Takaya E-mail: kunihito.ioka@kek.jp

    2014-07-01

    We examine dust formation in macronovae (as known as kilonovae), which are the bright ejecta of neutron star binary mergers and one of the leading sites of r-process nucleosynthesis. In light of information about the first macronova candidate associated with GRB 130603B, we find that dust grains of r-process elements have difficulty forming because of the low number density of the r-process atoms, while carbon or elements lighter than iron can condense into dust if they are abundant. Dust grains absorb emission from ejecta with an opacity even greater than that of the r-process elements, and re-emit photons at infrared wavelengths. Such dust emission can potentially account for macronovae without r-process nucleosynthesis as an alternative model. This dust scenario predicts a spectrum with fewer features than the r-process model and day-scale optical-to-ultraviolet emission.

  2. Dust devils on Mars

    NASA Technical Reports Server (NTRS)

    Thomas, P. G.; Gierasch, P.

    1985-01-01

    Large columns of dust have been discovered rising above plains on Mars. The storms are probably analogous to terrestrial dust devils, but their size indicates that they are more similar to tornadoes in intensity. They occur at locations where the soil has been strongly warmed by the Sun, and there the surface is smooth and fine grained. These are the same conditions that favor dust devils on Earth. Warm gas from the lowest atmospheric layer converges and rises in a thin column, with intense swirl developing at the edge of the column. In one area a mosaic of Viking images shows 97 vortices in a three day period. This represents a density of vortices of about one in each 900 square kilometers. Thus, these dust devils may be important in moving dust or starting over dust storms.

  3. Interstellar Dust: Physical Processes

    NASA Technical Reports Server (NTRS)

    Jones, A. P.; Tielens, A. G. G. M.

    1993-01-01

    Dust is formed in stellar environments, and destroyed by sputtering, shattering and vaporization in shock waves due to cloud-cloud collisions and supernova blast waves. Dust is also destroyed during star formation. We review the dust formation and destruction balance. The calculated destruction time-scale is less than or equal to one billion years and the star dust injection time-scale is approx. 2.5 billion years. Hence, the fractions of elemental carbon and silicon locked up in stardust are less than 0.3 and less than 0.15, respectively. An efficient ISM dust formation route is therefore implied. In particular, in dense clouds dust grows; through the processes of coagulation and the accretion of gas phase molecules e.g. H20, CO, CH4. These icy materials may then be photoprocessed to refractory materials in more diffuse regions. The resulting carbonaceous grain mantle may actually be the glue that holds the coagulated grains together.

  4. Dust Formation and Destruction

    NASA Astrophysics Data System (ADS)

    Wiebe, Dmitry

    Recent infrared and sub-millimeter observations have opened up a new window in dust evolution studies. High angular resolution of Spitzer and Herschel space telescopes from near to far-infrared wavelengths allows observing dust emission in galactic and extragalactic star-forming complexes, covering a broad range of metallicities, radiation field properties, etc. A wide-scale picture of dust evolution starts to arise from these observations. In my contribution I will try to cover major recent advances in studies of dust formation and destruction, including such topics as a diverse role of supernovae in dust evolution, possibility of dust formation and/or growth in molecular clouds, and VSG and PAH evolution in HII regions and complexes.

  5. Dust Devil Formation

    NASA Astrophysics Data System (ADS)

    Rafkin, S.; Jemmett-Smith, B.; Fenton, L.; Lorenz, R.; Takemi, T.; Ito, J.; Tyler, D.

    2016-11-01

    The essential dynamical characteristic of convective vortices, including dust devils, is a highly localized vorticity tube that extends into the vertical. This chapter is concerned with both the generation of vorticity and the subsequent focusing of that vorticity into a tight vortex, and with the environmental conditions that are conducive to the formation of convective vortices in general and dust devils in particular. A review of observations, theory, and modeling of dust devil formation is provided.

  6. Galaxy formation by dust

    NASA Technical Reports Server (NTRS)

    Wang, Boqi; Field, Goerge B.

    1989-01-01

    It has been known since the early 1940's that radiation can cause an instability in the interstellar medium. Absorbing dust particles in an isotropic radiation field shadow each other by a solid angle which is inversely proportional to the square of the distance between the two particles, leading to an inverse-square attractive force - mock gravity. The effect is largest in an optically thin medium. Recently Hogan and White (HW, hereafter) proposed that if the pre-galactic universe contained suitable sources of radiation and dust, instability in the dust distribution caused by mock gravity may have led to the formation of galaxies and galaxy clusters. In their picture of a well-coupled dust-gas medium, HW show that mock gravity begins to dominate gravitational instability when the perturbation becomes optically thin, provided that the radiation field at the time is strong enough. The recent rocket observation of the microwave background at submillimeter wavelengths by Matsumoto et al. might be from pre-galactic stars, the consequence of the absorption of ultraviolet radiation by dust, and infrared reemission which is subsequently redshifted. HW's analysis omits radiative drag, incomplete collisional coupling of gas and dust, finite dust albedo, and finite matter pressure. These effects could be important. In a preliminary calculation including them, the authors have confirmed that mock gravitational instability is effective if there is a strong ultraviolet radiation at the time, but any galaxies that form would be substantially enriched in heavy elements because the contraction of the dust is more rapid than that of the gas. Moreover, since the dust moves with supersonic velocity through the gas soon after the perturbation becomes optically thin, the sputtering of dust particles by gas is significant, so the dust could disappear before the instability develops significantly. They conclude that the mock gravity by dust is not important in galaxy formations.

  7. Spin-bowling in cricket re-visited: model trajectories for various spin-vector angles

    NASA Astrophysics Data System (ADS)

    Robinson, Garry; Robinson, Ian

    2016-08-01

    In this paper we investigate, via the calculation of model trajectories appropriate to slow bowling in cricket, the effects on the flight path of the ball before pitching due to changes in the angle of the spin-vector. This was accomplished by allowing the spin-vector to vary in three ways. Firstly, from off-spin, where the spin-vector points horizontally and directly down the pitch, to top-spin where it points horizontally towards the off-side of the pitch. Secondly, from off-spin to side-spin where, for side-spin, the spin-vector points vertically upwards. Thirdly, where the spin-vector points horizontally and at 45° to the pitch (in the general direction of ‘point’, as viewed by the bowler), and is varied towards the vertical, while maintaining the 45° angle in the horizontal plane. It is found that, as is well known, top-spin causes the ball to dip in flight, side-spin causes the ball to move side-ways in flight and, perhaps most importantly, off-spin can cause the ball to drift to the off-side of the pitch late in its flight as it begins to fall. At a more subtle level it is found that, if the total spin is kept constant and a small amount of top-spin is added to the ball at the expense of some off-spin, there is little change in the side-ways drift. However, a considerable reduction in the length at which the ball pitches occurs, ˜25 cm, an amount that batsmen can ignore at their peril. On the other hand, a small amount of side-spin introduced to a top-spin delivery does not alter the point of pitching significantly, but produces a considerable amount of side-ways drift, ˜10 cm or more. For pure side-spin the side-ways drift is up to ˜30 cm. When a side-spin component is added to the spin of a ball bowled with a mixture of off-spin and top-spin in equal proportions, significant movement occurs in both the side-ways direction and in the point of pitching, of the order of a few tens of centimetres.

  8. Staffing Levels at National Collegiate Athletic Association Football Bowl Subdivision-Level Institutions

    PubMed Central

    MS, Suzie Aparicio; Welch Bacon, Cailee E.; Parsons, John T.; Bay, R. Curtis; Cohen, Randy P.; DeZeeuw, Terry; McLeod, Tamara C. Valovich

    2015-01-01

    Context The “Appropriate Medical Coverage for Intercollegiate Athletics” (AMCIA) document was created to support assessment and calculation of athletic training personnel requirements. However, little is known regarding disparities between current and recommended staffing practices. Objective To identify the staffing and employment characteristics of athletic health care services at Football Bowl Subdivision-level institutions. Design Cross-sectional study. Setting Web-based survey. Patients or Other Participants Head athletic trainers and athletic training staff members who were knowledgeable about budget and staff. Main Outcome Measure(s) The survey, Assessment of Staffing Levels at National Collegiate Athletic Association Football Bowl Subdivision-Level Institutions, was used to evaluate personal, university, and staff demographics; staffing and employment topics; and AMCIA variables and use. Results The survey was accessed and partially completed by 104 individuals (response rate = 84.6%). A total of 79 athletic trainers (response rate = 76%) completed the entire survey. One-third of the respondents (34.2%, n = 26) met the recommended number of full-time equivalents (FTEs) for football, two-thirds of the respondents (65.7%, n = 50) failed to meet the recommendation, and 26.2% (n = 27) were missing data needed for FTE calculation. Among those who did not meet the recommended FTEs (n = 50), 38.0% (n = 19) were within 1 FTE of being compliant, 26.0% (n = 13) were within 2 FTEs, and 24.0% (n = 12) were within 3 FTEs. About one-third of respondents (35.9%, n = 37) reported not using the AMCIA, citing lack of funding (29.7%, n = 11), lack of administrative support (21.6%, n = 8), and other reasons (37.8%, n = 14). Conclusions The majority of institutions that used the AMCIA were able to provide justification for staffing. For most of the institutions that failed to meet their recommendation, adding 1–3 FTE athletic trainers for football would change their

  9. King's Bowl Pit Crater, Lava Field and Eruptive Fissure, Idaho - A Multipurpose Volcanic Planetary Analog

    NASA Astrophysics Data System (ADS)

    Hughes, S. S.; Garry, B.; Kobs-Nawotniak, S. E.; Sears, D. W. G.; Borg, C.; Elphic, R. C.; Haberle, C. W.; Kobayashi, L.; Lim, D. S. S.; Sears, H.; Skok, J. R.; Heldmann, J. L.

    2014-12-01

    King's Bowl (KB) and its associated eruptive fissure and lava field on the eastern Snake River Plain, is being investigated by the NASA SSERVI FINESSE (Field Investigations to Enable Solar System Science and Exploration) team as a planetary analog to similar pits on the Moon, Mars and Vesta. The 2,220 ± 100 BP basaltic eruption in Craters of the Moon National Monument and Preserve represents early stages of low shield growth, which was aborted when magma supply was cut off. Compared to mature shields, KB is miniscule, with ~0.02 km3 of lava over ~3 km2, yet the ~6 km long series of fissures, cracks and pits are well-preserved for analog studies of volcanic processes. The termination of eruption was likely related to proximity of the 2,270 ± 50 BP eruption of the much larger Wapi lava field (~5.5 km3 over 325 km2 area) on the same rift. Our investigation extends early work by R. Greeley and colleagues, focusing on imagery, compositional variations, ejecta distribution, dGPS profiles and LiDAR scans of features related to: (1) fissure eruptions - spatter ramparts, cones, feeder dikes, extension cracks; (2) lava lake formation - surface morphology, squeeze-ups, slab pahoehoe lava mounds, lava drain-back, flow lobe overlaps; and (3) phreatic steam blasts - explosion pits, ejecta blankets of ash and blocks. Preliminary results indicate multiple fissure eruptions and growth of a basin-filled lava lake up to ~ 10 m thick with outflow sheet lava flows. Remnant mounds of original lake crust reveal an early high lava lake level, which subsided as much as 5 m as the molten interior drained back into the fissure system. Rapid loss of magma supply led to the collapse of fissure walls allowing groundwater influx that triggered multiple steam blasts along at least 500 m. Early blasts occurred while lake magma pressure was still high enough to produce squeeze-ups when penetrated by ejecta blocks. The King's Bowl pit crater exemplifies processes of a small, but highly energetic

  10. Operational Dust Prediction

    NASA Technical Reports Server (NTRS)

    Benedetti, Angela; Baldasano, Jose M.; Basart, Sara; Benincasa, Francesco; Boucher, Olivier; Brooks, Malcolm E.; Chen, Jen-Ping; Colarco, Peter R.; Gong, Sunlin; Huneeus, Nicolas; Jones, Luke; Lu, Sarah; Menut, Laurent; Morcrette, Jean-Jacques; Mulcahy, Jane; Nickovic, Slobodan; Garcia-Pando, Carlos P.; Reid, Jeffrey S.; Sekiyama, Thomas T.; Tanaka, Taichu Y.; Terradellas, Enric; Westphal, Douglas L.; Zhang, Xiao-Ye; Zhou, Chun-Hong

    2014-01-01

    Over the last few years, numerical prediction of dust aerosol concentration has become prominent at several research and operational weather centres due to growing interest from diverse stakeholders, such as solar energy plant managers, health professionals, aviation and military authorities and policymakers. Dust prediction in numerical weather prediction-type models faces a number of challenges owing to the complexity of the system. At the centre of the problem is the vast range of scales required to fully account for all of the physical processes related to dust. Another limiting factor is the paucity of suitable dust observations available for model, evaluation and assimilation. This chapter discusses in detail numerical prediction of dust with examples from systems that are currently providing dust forecasts in near real-time or are part of international efforts to establish daily provision of dust forecasts based on multi-model ensembles. The various models are introduced and described along with an overview on the importance of dust prediction activities and a historical perspective. Assimilation and evaluation aspects in dust prediction are also discussed.

  11. Dust Devil Tracks

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 8 May 2002) The Science This image, centered near 50.0 S and 17.7 W displays dust devil tracks on the surface. Most of the lighter portions of the image likely have a thin veneer of dust settled on the surface. As a dust devil passes over the surface, it acts as a vacuum and picks up the dust, leaving the darker substrate exposed. In this image there is a general trend of many of the tracks running from east to west or west to east, indicating the general wind direction. There is often no general trend present in dust devil tracks seen in other images. The track patterns are quite ephemeral and can completely change or even disappear over the course of a few months. Dust devils are one of the mechanisms that Mars uses to constantly pump dust into the ubiquitously dusty atmosphere. This atmospheric dust is one of the main driving forces of the present Martian climate. The Story Vrrrrooooooooom. Think of a tornado, the cartoon Tasmanian devil, or any number of vacuum commercials that powerfully suck up swirls of dust and dirt. That's pretty much what it's like on the surface of Mars a lot of the time. Whirlpools of wind called

  12. Characterization of microorganisms isolated from the black dirt of toilet bowls and componential analysis of the black dirt.

    PubMed

    Mori, Miho; Nagata, Yusuke; Niizeki, Kazuma; Gomi, Mitsuhiro; Sakagami, Yoshikazu

    2014-01-01

    We have previously conducted a microflora analysis and examined the biofilm-forming activity of bacteria isolated from toilet bowl biofilms. In the present investigation, to reveal the strain involved in the formation of black dirt in toilet bowls, we performed a microflora analysis of the bacteria and fungi isolated from the black dirt of toilet bowls at ten homes. Among samples from different isolation sites and sampling seasons, although a similar tendency was not seen in bacterial microflora, Exophiala sp. was detected in the fungal microflora from all samples of black dirt except for one, and constituted the major presence. By scanning electron microscope (SEM) analysis of the formed black dirt, SEM image at × 1,000 and × 5,000 magnification showed objects like hyphae and many bacteria adhering to them, respectively. Micro fourier transform infrared spectroscopy (micro FT-IR) and SEM with X-ray microanalysis (SEM-XMA) were used to investigate the components of black dirt. IR spectra of micro-FT-IR showed typical absorptions associated with amide compounds and protein, and the elements such as C, N, O, Na, Mg, Al, Si, P, S, K, and Ba were detected with SEM-XMA. These results showed that black dirt had living body ingredients. Furthermore, Exophiala sp. and Cladosporium sp. strains, which were observed at a high frequency, accumulated 2-hydroxyjuglone (2-HJ) and flaviolin as one of the intermediates in the melanin biosynthetic pathway by the addition of a melanin synthesis inhibitor (tricyclazole) at the time of cultivation. These results suggested strongly that the pigment of black dirt in toilet bowls was melanin produced by Exophiala sp. and Cladosporium sp. strains.

  13. Biofilm-forming activity of bacteria isolated from toilet bowl biofilms and the bactericidal activity of disinfectants against the isolates.

    PubMed

    Mori, Miho; Gomi, Mitsuhiro; Matsumune, Norihiko; Niizeki, Kazuma; Sakagami, Yoshikazu

    2013-01-01

    To evaluate the sanitary conditions of toilets, the bacterial counts of the toilet bowl biofilms in 5 Kansai area and 11 Kansai and Kanto area homes in Japan were measured in winter and summer seasons, respectively. Isolates (128 strains) were identified by analyzing 16S ribosomal RNA sequences. The number of colonies and bacterial species from biofilms sampled in winter tended to be higher and lower, respectively, than those in summer. Moreover, the composition of bacterial communities in summer and winter samples differed considerably. In summer samples, biofilms in Kansai and Kanto areas were dominated by Blastomonas sp. and Mycobacterium sp., respectively. Methylobacterium sp. was detected in all toilet bowl biofilms except for one sample. Methylobacterium sp. constituted the major presence in biofilms along with Brevundimonas sp., Sphingomonas sp., and/or Pseudomonas sp. The composition ratio of the sum of their genera was 88.0 from 42.9% of the total bacterial flora. The biofilm formation abilities of 128 isolates were investigated, and results suggested that Methylobacterium sp. and Sphingomonas sp. were involved in biofilm formation in toilet bowls. The biofilm formation of a mixed bacteria system that included bacteria with the highest biofilm-forming ability in a winter sample was greater than mixture without such bacteria. This result suggests that isolates possessing a high biofilm-forming activity are involved in the biofilm formation in the actual toilet bowl. A bactericidal test against 25 strains indicated that the bactericidal activities of didecyldimethylammonium chloride (DDAC) tended to be higher than those of polyhexamethylene biguanide (PHMB) and N-benzyl-N,N-dimethyldodecylammonium chloride (ADBAC). In particular, DDAC showed high bactericidal activity against approximately 90% of tested strains under the 5 h treatment.

  14. Family fun or cultural free-for-all? A critique of the 2015 National Football League Super Bowl commercials

    PubMed Central

    Basch, Corey H.; Kernan, William D; Reeves, Rachel

    2016-01-01

    Background: The purpose of this cross-sectional study was to enumerate and describe violent and risky behaviors as well as other general health behaviors exhibited in the advertisements during the National Football League (NFL) Super Bowl 2015. Methods: Commercials during the NFL Super Bowl 2015 were assessed for violent and risky behaviors. Additional health behaviors were indicated such as the advertisement of unhealthy food, promotion of physical activity, and sexual content. Results: A total of 110 commercials were documented, accounting for 64 minutes of broadcast time. Commercials promoting automobiles, television shows, food, and movies were the most prevalent, representing just over half (53.7%) of all of the advertisements featured. Depictions of unsafe driving were found in 10.9% (n = 12) of the commercials. All 12 commercials contained some sort of risky or wild driving behavior, and speeding was observed in 11 of the 12 commercials. A total of 32 (29.1%) of the commercials were coded as including violent content.Physical activity behavior was present in 3 (2.7%) of the commercials. Conversely, substance use was observed in 3 (2.7%) of the commercials, none of which included health promotion messaging. Of the 110 commercials aired during the 2015 Super Bowl, 12.7% (n = 14) included sexual content. Conclusion: Parents should consider the possibility that their children may observe acts of violence or conflicting safety messages during commercial breaks. PMID:27123435

  15. Whither Cometary Dust?

    NASA Astrophysics Data System (ADS)

    Lisse, Carey M.

    2010-10-01

    In this paper I will discuss recent findings that have important implications for our understanding of the formation and evolution of primitive solar system dust, including: - Nesvorny et al. (2010), following up on their dynamical analyses of the zodiacal dust bands as sourced by the breakup of the Karin (5Mya) and Veritas (8Mya) asteroid families, argue that over 90% of the interplanetary dust cloud at 1 AU comes from JFC comets with near-circularized, low inclination orbits. This implies that the noted IPD collections of anhydrous and hydrous dust particles are likely to be from Oort cloud and JFC comets, respectively, not from asteroids and comets as thought in the past. Hydrous dust particles from comets like 85P/Wild2 and 9P/Tempel 1 would be consistent with results from the STARDUST and Deep Impact experiments. - Estimates of the dust particle size distributions (PSDs) in the comae of 85P/Wild2 (Green et al. 2004, 2007) and 73P/SW-3 (Sitko et al. 2010, Vaubaillon & Reach 2010) and in the trails of comets (Reach et al. 2007) have broken power law structure, with a plateau enhancement of particles of 1 mm - 1 cm in size. This size is also the size of most chondritic inclusions, and the predicted size range of the "aggregational barrier", where collisions between dust particles become destructive. - Studies of the albedo and polarization properties of cometary dust (Kolokolova et al. 2007) suggest there are 2 major groupings, one with low scattering capability and one with high. While these families could possibly have been explained by systematics in the PSDs of the emitted dust, independent work by Lisse et al. (2008) on the mineralogy of a number of highly dusty comets has shown evidence for one family of comets with highly crystalline dust and another with highly amorphous dust.

  16. Orthogonal experiment and analysis on process parameters of bowl feed polishing (BFP)

    NASA Astrophysics Data System (ADS)

    Meng, Kai; Wan, Yongjian; Xu, Qinglan; Yang, Yang

    2013-08-01

    With the development of science and technology, the demand for high-precision product is increasing continuously. Ultra-smooth surface with sub-nanometer roughness has extensive applications in the field of soft X-ray optics, high power laser and laser gyro. Bowl feed polishing (BFP) technology is an effective ultra-smooth surface processing method, but the polishing process of BFP which is affected by a lot of factors is extremely complex and difficult to control. It is important to understand the effect of the process variables such as abrasive particle size, concentration of abrasive particle, speed of polishing pad, acidity and polishing time in the process of BFP. They are very important parameters that must be carefully formulated to achieve desired material removal rates and surface roughness. Using a design of experiment (DOE) approach, this study was performed investigating the main effect of the each parameter during K9 BFP. A better understanding of the interaction behavior between the various parameters and the effect on removal rate and surface roughness is achieved by using the statistical analysis techniques. In the experimental tests, the optimized parameters combination for BFP which were derived from the statistical analysis could be found for material removal rate and better surface roughness through the above experiment results.

  17. Tuning the Structural Color of a 2D Photonic Crystal Using a Bowl-like Nanostructure.

    PubMed

    Umh, Ha Nee; Yu, Sungju; Kim, Yong Hwa; Lee, Su Young; Yi, Jongheop

    2016-06-22

    Structural colors of the ordered photonic nanostructures are widely used as an effective platform for manipulating the propagation of light. Although several approaches have been explored in attempts to mimic the structural colors, improving the reproducibility, mechanical stability, and the economic feasibility of sophisticated photonic crystals prepared by complicated processes continues to pose a challenge. In this study, we report on an alternative, simple method for fabricating a tunable photonic crystal at room temperature. A bowl-like nanostructure of TiO2 was periodically arranged on a thin Ti sheet through a two-step anodization process where its diameters were systemically controlled by changing the applied voltage. Consequently, they displayed a broad color distribution, ranging from red to indigo, and the principal reason for color generation followed the Bragg diffraction theory. This noncolorant method was capable of reproducing a Mondrian painting on a centimeter scale without the need to employ complex architectures, where the generated structural colors were highly stable under mechanical or chemical influence. Such a color printing technique represents a potentially promising platform for practical applications for anticounterfeit trademarks, wearable sensors, and displays.

  18. Dust and Smoke

    Atmospheric Science Data Center

    2014-05-15

    ... dust, the most common non-spherical aerosol type, from pollution and forest fire particles. Determining aerosol characteristics is a ... aerosol is quite thick, and in some places, the dust over water is too optically thick for MISR to retrieve the aerosol amount. For the ...

  19. Combustible dust tests

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sugar dust explosion in Georgia on February 7, 2008 killed 14 workers and injured many others (OSHA, 2009). As a consequence of this explosion, OSHA revised its Combustible Dust National Emphasis (NEP) program. The NEP targets 64 industries with more than 1,000 inspections and has found more tha...

  20. Space dust in Paris

    NASA Astrophysics Data System (ADS)

    2017-02-01

    Next time you take a stroll in Paris, Oslo or Berlin, you might be breathing in big particles of cosmic dust after a study led by earth scientist Matthew Genge from Imperial College London found tiny specks of space dust on the rooftops of the three European capitals.

  1. Dust resuspension without saltation

    PubMed Central

    Loosmore, Gwen A.; Hunt, James R.

    2010-01-01

    Wind resuspension (or entrainment) provides a source of dust and contaminants for the atmosphere. Conventional wind erosion models parameterize dust resuspension flux with a threshold velocity or with a horizontal abrasion flux; in the absence of abrasion the models assume dust flux is transient only. Our experiments with an uncrusted, fine material at relative humidities exceeding 40% show a long-term steady dust flux in the absence of abrasion, which fits the approximate form: Fd = 3.6(u*)3, where Fd is the dust flux (in μg/m2 s), and u* is the friction velocity (in m/s). These fluxes are generally too small to be significant sources of dust in most models of dust emission. However, they provide a potential route to transport contaminants into the atmosphere. In addition, dust release is substantial during the initial transient phase. Comparison with field data suggests that the particle friction Reynolds number may prove a better parameter than u* for correlating fluxes and understanding the potential for abrasion. PMID:20336175

  2. Dust in supernova remnants

    NASA Astrophysics Data System (ADS)

    Gomez, H.

    In this Review, I will discuss our changing view on supernovae as interstellar dust sources. In particular I will focus on infrared and submillimetre studies of the historical supernova remnants Cassiopeia A, the Crab Nebula, SN 1987A, Tycho and Kepler. In the last decade (and particularly in recent years), SCUBA, Herschel and ALMA have now demonstrated that core-collapse supernovae are prolific dust factories, with evidence of 0.1 - 0.7 M⊙ of dust formed in the ejecta, though there is little evidence (as yet) for significant dust production in Type Ia supernova ejecta. There is no longer any question that dust (and molecule) formation is efficient after some supernova events, though it is not clear how much of this will survive over longer timescales. Current and future instruments will allow us to investigate the spatial distribution of dust within corecollapse ejecta, and whether this component contributes a significant amount to the dust content of the Universe or if supernovae ultimately provide a net loss once dust destruction by shocks is taken into account.

  3. Supernova Dust Factories

    NASA Astrophysics Data System (ADS)

    Gomez, Haley; Consortium, MESS; LCOGT

    2013-01-01

    The origin of interstellar dust in galaxies is poorly understood, particularly the relative contribution from supernovae. We present infrared and submillimeter photometry and spectroscopy from the Herschel Space Observatory of the Galactic remnants Tycho, Kepler and the Crab Nebula, taken as part of the Mass Loss from Evolved StarS program (MESS). Although we detect small amounts of dust surrounding Tycho and Kepler (the remnants of Type Ia supernovae), we show this is due to swept-up interstellar and circumstellar material respectively. The lack of dust grains in the ejecta suggests that Type Ia remnants do not produce substantial quantities of iron-rich dust grains and has important consequences for the ‘missing’ iron mass observed in ejecta. After carefully subtracting the synchrotron and line emission from the Crab, the remaining far-infrared continuum originates from 0.1-0.2 solar masses of dust. These observations suggest that the Crab Nebula has condensed most of the relevant refractory elements into dust and that these grains appear well set to survive their journey into the interstellar medium. In summary, our Herschel observations show that significantly less dust forms in the ejecta of Type Ia supernovae than in the remnants of core-collapse explosions, placing stringent constraints on the environments in which dust and molecules can form.

  4. Talc dust pneumoconiosis.

    PubMed

    Berner, A; Gylseth, B; Levy, F

    1981-01-01

    Various types of mineral dust can induce interstitial pulmonary fibrosis, but there is no definite correlation between lung X-ray findings, tissue lesions and the type of dust. In this paper, we report on the post mortem verification of talcosis by lung tissue analysis, using light microscopy, scanning electron microscopy, energy dispersive x-ray microanalysis and x-ray diffractometry.

  5. Mixed-method pre-cooling reduces physiological demand without improving performance of medium-fast bowling in the heat.

    PubMed

    Minett, Geoffrey M; Duffield, Rob; Kellett, Aaron; Portus, Marc

    2012-05-01

    This study examined physiological and performance effects of pre-cooling on medium-fast bowling in the heat. Ten, medium-fast bowlers completed two randomised trials involving either cooling (mixed-methods) or control (no cooling) interventions before a 6-over bowling spell in 31.9±2.1°C and 63.5±9.3% relative humidity. Measures included bowling performance (ball speed, accuracy and run-up speeds), physical characteristics (global positioning system monitoring and counter-movement jump height), physiological (heart rate, core temperature, skin temperature and sweat loss), biochemical (serum concentrations of damage, stress and inflammation) and perceptual variables (perceived exertion and thermal sensation). Mean ball speed (114.5±7.1 vs. 114.1±7.2 km · h(-1); P = 0.63; d = 0.09), accuracy (43.1±10.6 vs. 44.2±12.5 AU; P = 0.76; d = 0.14) and total run-up speed (19.1±4.1 vs. 19.3±3.8 km · h(-1); P = 0.66; d = 0.06) did not differ between pre-cooling and control respectively; however 20-m sprint speed between overs was 5.9±7.3% greater at Over 4 after pre-cooling (P = 0.03; d = 0.75). Pre-cooling reduced skin temperature after the intervention period (P = 0.006; d = 2.28), core temperature and pre-over heart rates throughout (P = 0.01-0.04; d = 0.96-1.74) and sweat loss by 0.4±0.3 kg (P = 0.01; d = 0.34). Mean rating of perceived exertion and thermal sensation were lower during pre-cooling trials (P = 0.004-0.03; d = 0.77-3.13). Despite no observed improvement in bowling performance, pre-cooling maintained between-over sprint speeds and blunted physiological and perceptual demands to ease the thermoregulatory demands of medium-fast bowling in hot conditions.

  6. Dust evolution from comets

    NASA Technical Reports Server (NTRS)

    Sekanina, Z.

    1977-01-01

    The studies of the evolution of cometary debris are reviewed. The subject is divided into three major sections: (1) the developments in the immediate vicinity of the cometary nucleus, which is the source of the dust; (2) the formation of the dust tail; and (3) the blending of the debris with the dust component of interplanetary matter. The importance of the physical theory of comets is emphasized for the understanding of the early phase of the evolution of cometary dust. A physico-dynamical model designed to analyze the particle-emission mechanism from the distribution of light in the dust tails is described and the results are presented. Increased attention is paid to large particles because of their importance for the evolution of the zodiacal cloud. Finally, implications are discussed for the future in situ investigations of comets.

  7. Dust escape from Io

    NASA Astrophysics Data System (ADS)

    Flandes, Alberto

    2004-08-01

    The Dust ballerina skirt is a set of well defined streams composed of nanometric sized dust particles that escape from the Jovian system and may be accelerated up to >=200 km/s. The source of this dust is Jupiter's moon Io, the most volcanically active body in the Solar system. The escape of dust grains from Jupiter requires first the escape of these grains from Io. This work is basically devoted to explain this escape given that the driving of dust particles to great heights and later injection into the ionosphere of Io may give the particles an equilibrium potential that allow the magnetic field to accelerate them away from Io. The grain sizes obtained through this study match very well to the values required for the particles to escape from the Jovian system.

  8. Lunar Dust Mitigation Screens

    NASA Astrophysics Data System (ADS)

    Knutson, Shawn; Holloway, Nancy

    With plans for the United States to return to the moon, and establish a sustainable human presence on the lunar surface many issues must be successfully overcome. Lunar dust is one of a number of issues with the potential to create a myriad of problems if not adequately addressed. Samples of dust brought back from Apollo missions show it to be soft, yet sharp and abrasive. The dust consists of a variety of morphologies including spherical, angular blocks, shards, and a number of irregular shapes. One of the main issues with lunar dust is its attraction to stick to anything it comes in contact with (i.e. astronauts, equipment, habitats, etc.). Ionized radiation from the sun strikes the moon's surface and creates an electrostatic charge on the dust. Further, the dust harbors van der Waals forces making it especially difficult to separate once it sticks to a surface. During the Apollo missions, it was discovered that trying to brush the lunar dust from spacesuits was not effective, and rubbing it caused degradation of the suit material. Further, when entering the lunar module after moonwalks, the astronauts noted that the dust was so prolific inside the cabin that they inhaled and ingested it, causing at least one of them, Harrison "Jack" Schmidt, to report irritation of the throat and lungs. It is speculated that the dust could also harm an astronaut's nervous and cardiovascular systems, especially during an extended stay. In addition to health issues, the dust can also cause problems by scouring reflective coatings off of thermal blankets, and roughening surfaces of windows and optics. Further, panels on solar cells and photovoltaics can also be compromised due to dust sticking on the surfaces. Lunar dust has the capacity to penetrate seals, interfere with connectors, as well as mechanisms on digging machines, all of which can lead to problems and failure. To address lunar dust issues, development of electrostatic screens to mitigate dust on sur-faces is currently

  9. Coupled patterns of spatiotemporal variability in Northern Hemisphere sea level pressure and conterminous U.S. drought

    NASA Astrophysics Data System (ADS)

    Zhang, Zhihua; Mann, Michael E.

    2005-02-01

    We apply the multitaper frequency domain-singular value decomposition signal detection method to the investigation of coherent patterns of variation in seasonal Northern Hemisphere sea level pressure and conterminous U.S. summer drought during the period 1895-1995. The analysis identifies statistically significant patterns of spatiotemporal variability on interannual and bidecadal timescales indicative of both cold-season and warm-season atmospheric influences on North American drought patterns. The most robust signal found appears to be associated with the influences of the El Niño-Southern Oscillation (ENSO) on North American summer drought. Evidence is also found to support the existence of a roughly bidecadal drought signal tied to warm-season atmospheric circulation changes. The "Dust Bowl" conditions of the 1930s appear to result from a combination of these bidecadal influences on drought conditions that coincide with a decrease in the amplitude of interannual ENSO-related variability during the 1930s.

  10. Dust Devil Dynamics

    NASA Astrophysics Data System (ADS)

    Horton, W.; Miura, H.

    2008-11-01

    A dust devil is a rotating updraft, with coherent structures ranging from small (H/D ˜ 5m/1m) to large (H/D ˜ 1000 m/10 m). Common in west Texas and Arizona, dust devils are formed unstable stratification of the air by solar heating over a sandy floor. Unstable gravity waves grow exponentially in the low density, hot air, rising into the upper layer of stably stratified atmosphere creating the large, 3D vortex. Dust devils are common on Mars. On Earth radio noise and electrical fields greater than 100kV/m are inferred [Kok J. F., N. O. Renno (2006), Geophys. Res. Lett., 33, L19S10]. Dust devils pick up small dirt and dust particles. The whirling charged dust particles (30 -50 microns) create a magnetic field that fluctuates between 3 and 30 times each second. The electric fields created assist the vortices in lifting materials off the ground and into the atmosphere. We use the theory and simulation tools of fusion plasma physics to describe dust devils. The Grad-Shafranov equation governs the vorticity dynamics and gives a solution for steady axisymmetric flows. The high core velocity is limited by the vortex model with viscous dissipation. The Reynolds number is not large, so these structures are well represented with super computers, in contrast to collisionless plasmas. 1mm Research supported by NIFS, Japan and the NSF through ATM-0638480 at UT Austin.

  11. Dust storms: recent developments.

    PubMed

    Goudie, Andrew S

    2009-01-01

    Dust storms have a number of impacts upon the environment including radiative forcing, and biogeochemical cycling. They transport material over many thousands of kilometres. They also have a range of impacts on humans, not least on human health. In recent years the identification of source areas for dust storms has been an important area or research, with the Sahara (especially Bodélé) and western China being recognised as the strongest sources globally. Another major development has been the recognition of the degree to which dust storm activity has varied at a range of time scales, millennial, century, decadal, annual and seasonal.

  12. Spirit Feels Dust Gust

    NASA Technical Reports Server (NTRS)

    2007-01-01

    On sol 1149 (March 28, 2007) of its mission, NASA's Mars Exploration Rover Spirit caught a wind gust with its navigation camera. A series of navigation camera images were strung together to create this movie. The front of the gust is observable because it was strong enough to lift up dust. From assessing the trajectory of this gust, the atmospheric science team concludes that it is possible that it passed over the rover. There was, however, no noticeable increase in power associated with this gust. In the past, dust devils and gusts have wiped the solar panels of dust, making it easier for the solar panels to absorb sunlight.

  13. Climate Warming and 21st-Century Drought in Southwestern North America

    NASA Astrophysics Data System (ADS)

    MacDonald, Glen M.; Stahle, David W.; Diaz, Jose Villanueva; Beer, Nicholas; Busby, Simon J.; Cerano-Paredes, Julian; Cole, Julie E.; Cook, Edward R.; Endfield, Georgina; Gutierrez-Garcia, Genaro; Hall, Beth; Magana, Victor; Meko, David M.; Méndez-Pérez, Matias; Sauchyn, David J.; Watson, Emma; Woodhouse, Connie A.

    2008-02-01

    Since 2000, southwestern North America has experienced widespread drought. Lakes Powell and Mead are now at less than 50% of their reservoir capacity, and drought or fire-related states of emergency were declared this past summer by governors in six western states. As with other prolonged droughts, such as the Dust Bowl during the 1930s, aridity has at times extended from northern Mexico to the southern Canadian prairies. A synthesis of climatological and paleoclimatological studies suggests that a transition to a more arid climate may be occurring due to global warming, with the prospect of sustained droughts being exacerbated by the potential reaction of the Pacific Ocean to warming.

  14. Dust Mite Allergy

    MedlinePlus

    ... a pollen allergy may be noticeable because the allergy is seasonal. For example, you may have more difficulty managing your asthma for a short time during the summer. Dust mite allergy, on the other hand, is due to something ...

  15. 1983 Transatlantic Dust Event

    NASA Video Gallery

    This visualization (prepared in 2001) shows dust being blown westward over the Atlantic from northern Africa in early 1983, from aerosol measurements taken by Nimbus 7's TOMS instrument. Saharan du...

  16. Composite circumstellar dust grains

    NASA Astrophysics Data System (ADS)

    Gupta, Ranjan; Vaidya, Dipak B.; Dutta, Rajeshwari

    2016-10-01

    We calculate the absorption efficiencies of composite silicate grains with inclusions of graphite and silicon carbide in the spectral range 5-25 μm. We study the variation in absorption profiles with volume fractions of inclusions. In particular we study the variation in the wavelength of peak absorption at 10 and 18 μm. We also study the variation of the absorption of porous silicate grains. We use the absorption efficiencies to calculate the infrared flux at various dust temperatures and compare with the observed infrared emission flux from the circumstellar dust around some M-type and asymptotic giant branch stars obtained from IRAS and a few stars from Spitzer satellite. We interpret the observed data in terms of the circumstellar dust grain sizes, shape, composition and dust temperature.

  17. Dust evolution from comets

    NASA Technical Reports Server (NTRS)

    Sekanina, Z.

    1976-01-01

    The studies of the evolution of cometary debris are reviewed. The subject is divided into three major sections: (1) the developments in the immediate vicinity of the cometary nucleus, which is the source of the dust; (2) the formation of the dust tail; and (3) the blending of the debris with the dust component of interplanetary matter. The importance of the physical theory of comets is emphasized for the understanding of the early phase of evolution. A physico-dynamical model designed to analyze the particle-emission mechanism from the distribution of light in the dust tail is described and the results are presented. Increased attention is paid to large particles because of their importance for the evolution of the zodiacal cloud. Finally, implications are discussed for the future in situ investigations of comets.

  18. The Lunar Dust Pendulum

    NASA Technical Reports Server (NTRS)

    Collier, Michael R.; Stubbs, Timothy J.; Farrell, William M.

    2011-01-01

    Shadowed regions on the lunar surface acquire a negative potential. In particular, shadowed craters can have a negative potential with respect to the surrounding lunar regolith in sunlight, especially near the terminator regions. Here we analyze the motion of a positively charged lunar dust grain in the presence of a shadowed crater at a negative potential in vacuum. Previous models describing the transport of charged lunar dust close to the surface have typically been limited to one-dimensional motion in the vertical direction, e.g. electrostatic levitation; however, the electric fields in the vicinity of shadowed craters will also have significant components in the horizontal directions. We propose a model that includes both the horizontal and vertical motion of charged dust grains near shadowed craters. We show that the dust grains execute oscillatory trajectories and present an expression for the period of oscillation drawing an analogy to the motion of a pendulum.

  19. The Lunar Dust Pendulum

    NASA Technical Reports Server (NTRS)

    Kuntz, Kip; Collier, Michael R.; Stubbs, Timothy J.; Farrell, William M.

    2011-01-01

    Shadowed regions on the lunar surface acquire a negative potential. In particular, shadowed craters can have a negative potential with respect to the surrounding lunar regolith in sunlight, especially near the terminator regions. Here we analyze the motion of a positively charged lnnar dust grain in the presence of a shadowed crater at a negative potential in vacuum. Previous models describing the transport of charged lunar dust close to the surface have typically been limited to one-dimensional motion in the vertical direction, e.g. electrostatic levitation; however. the electric fields in the vicinity of shadowed craters will also have significant components in the horizontal directions. We propose a model that includes both the horizontal and vertical motion of charged dust grains near shadowed craters. We show that the dust grains execute oscillatory trajectories and present an expression for the period of oscillation drawing an analogy to the motion of a pendulum.

  20. Adhesion of Lunar Dust

    NASA Technical Reports Server (NTRS)

    Walton, Otis R.

    2007-01-01

    This paper reviews the physical characteristics of lunar dust and the effects of various fundamental forces acting on dust particles on surfaces in a lunar environment. There are transport forces and adhesion forces after contact. Mechanical forces (i.e., from rover wheels, astronaut boots and rocket engine blast) and static electric effects (from UV photo-ionization and/or tribo-electric charging) are likely to be the major contributors to the transport of dust particles. If fine regolith particles are deposited on a surface, then surface energy-related (e.g., van der Walls) adhesion forces and static-electric-image forces are likely to be the strongest contributors to adhesion. Some measurement techniques are offered to quantify the strength of adhesion forces. And finally some dust removal techniques are discussed.

  1. Outreach for Families and Girls- Astronomy at Outdoor Concerts and at Super Bowl or Halloween Star Parties

    NASA Astrophysics Data System (ADS)

    Lubowich, Donald A.

    2011-05-01

    Bring telescope to where the people are! Music and Astronomy Under the Stars (MAUS) is a NASA-funded as astronomy outreach program at community parks and music festivals (1000 - 25,000 people/event). While there have been many astronomy outreach activities and telescope observations at sidewalks and parks, this program targets a different audience - music lovers who are attending concerts in community parks or festivals. These music lovers who may not have visited science museums, planetariums, or star parties are exposed to telescope observations and astronomy information with no additional travel costs. MAUS includes solar observing, telescope observations including a live imaging system, an astronomical video, astronomy banners/posters, and hands-on activities. MAUS increased awareness, engagement, and interest in astronomy at classical, pop, rock, and ethnic music concerts. Since 2009 over 50,000 people have participated in these outreach activities including a significant number of families and young girls. In addition to concerts in local Long Island parks, there were MUAS events at Tanglewood (summer home of the Boston Symphony Orchestra), Jazz in Central Park, and Astronomy Night on the National Mall (co-sponsored by the White House Office of Science and Technology Policy). In 2011 MUAS will be expanded to include Ravinia (summer home of the Chicago Symphony Orchestra), the Newport Folk Festival, and the Bethel Woods Center for the Arts (site of the 1969 Woodstock festival). According to our survey results, music lovers became more informed about astronomy. Expanding Hofstra University's successful outreach programs, I propose the creation of a National Halloween Stars event targeting children and a National Super Bowl Star Party targeting girls, women, and the 2/3 of Americans who do not watch the Super Bowl. This can be combined with astronomers or amateur astronomers bringing telescopes to Super Bowl parties for football fans to stargaze during

  2. Isotopic and geologic studies of the veins of the Bowling Green Fault Zone, Ohio, and their genetic implications

    SciTech Connect

    Carlson, E.H. . Dept. of Geology)

    1992-01-01

    The veins of the Bowling Green Fault Zone, a prominent tectonic feature in the eastern Midwest, provide new data on the control of this structure by a zone of basement weakness. The dominant phase of the veins is brown calcite which contains a component of radiogenic strontium that is absent in the vug calcite of the region. These 1--50 cm thick veins occur along the margins of the northerly trending fault zone and occupy steeply dipping extension fractures that strike approximately N40 W. Similar northwest trending extension veins that lack the brown calcite are common elsewhere in the area at sites distanced from the fault. The Sr-87/Sr-86 ratio of the brown calcite is 0.70897 [+-] 2 while those of the Late Silurian host dolostone and vug calcite at Waterville, Ohio, are 0.70861 [+-] 2 and 0.70854 [+-] 2, respectively. Minor pyrite, which coats the walls, and successive layers of solid hydrocarbons and colorless calcite, which line vugs in the veins, allow the broken calcite to be placed in the paragenetic sequence of the region. The vein calcite is both UV fluorescent and cathodoluminescent; minor amounts of manganese are present in this material. The strontium of the brown calcite was derived from the underlying rocks, supporting a genetic link between the Bowling Green Fault and the Grenville Front. The vein calcite postdates the last movement of the Bowling Green Fault and predates the Late Paleozoic hydrocarbons and brine-deposited zinc and lead sulfides that are widespread in the vuggy Silurian and Devonian carbonate rocks of the region. The temporal equivalence of these sulfides and those occurring below along fractures zones in the Middle Ordovician Trenton Limestone is probable, based on the similarity of their parageneses.

  3. Comments on Dust Reverberation

    NASA Astrophysics Data System (ADS)

    Peterson, B.

    2015-09-01

    Dust reverberation is an important technique for studying the inner structure of AGNs and probing the properties of astrophysical dust, and even has some potential as a cosmological probe. We will discuss two recent results that pose a serious limitation to understanding dust reverberation at the present time. First, recent high-cadence monitoring of the UV and optical continuum in two AGNs, NGC 2617 and NGC 5548, have yielded unambiguous lags between variations of the UV continuum and corresponding variations of the continuum at longer wavelengths. In the absence of UV data, this leads to a systematic underestimate of the innermost radius where dust is found. This similarly leads to an underestimate of the size of the broad emission-line region, although it does not affect the AGN black hole mass scale, which calibrates out this effect. Second, broad-band monitoring of continuum variations in the optical through near-IR show that the innermost dust is not necessarily at the 'instantaneous sublimation radius.' The innermost dust can be considerably cooler than expected at the sublimation radius and thus can heat up without sublimating when the central continuum source becomes more luminous (see the poster by Pott).

  4. The Galileo Dust Detector

    NASA Technical Reports Server (NTRS)

    Gruen, Eberhard; Fechtig, Hugo; Hanner, Martha S.; Kissel, Jochen; Lindblad, Bertil-Anders; Linkert, Dietmar; Maas, Dieter; Morfill, Gregor E.; Zook, Herbert A.

    1992-01-01

    The Galileo Dust Detector is intended to provide direct observations of dust grains with masses between 10 exp -19 and 10 exp -9 kg in interplanetary space and in the Jovian system, to investigate their physical and dynamical properties as functions of the distances to the sun, to Jupiter and to its satellites, and to study its interaction with the Galilean satellites and the Jovian magnetosphere. The investigation is performed with an instrument that measures the mass, speed, flight direction and electric charge of individual dust particles. It is a multicoincidence detector with a mass sensitivity 1 000 000 times higher than that of previous in situ experiments which measured dust in the outer solar system. The instrument weighs 4.2 kg, consumes 2.4 W, and has a normal data transmission rate of 24 bits/s in nominal spacecraft tracking mode. On December 29, 1989 the instrument was switched-on. After the instrument had been configured to flight conditions cruise science data collection started immediately. In the period to May 18, 1990 at least 168 dust impacts have been recorded. For 81 of these dust grains masses and impact speeds have been determined. First flux values are given.

  5. Hebes Chasma Dust Avalanches

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    Dust avalanches, also called slope streaks, occur on many Martian terrains. The deposition of airborne dust on surfaces causes a bright tone in the THEMIS VIS images. Any movement of the dust downhill, a dust avalanche, will leave behind a streak where the darker, dust-free surface is exposed.

    These dust avalanches are located in Hebes Chasma.

    Image information: VIS instrument. Latitude -1.4, Longitude 286.6 East (73.4 West). 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  6. Selecting baghouse dust collectors

    SciTech Connect

    Moore, S.; Rubak, J.; Jolin, M. |

    1996-10-01

    Control of nuisance or process dusts generated within a plant is a vital concern with today`s growing emphasis on indoor air quality. In the past, many companies simply moved these contaminants away from workers and discharged them into the atmosphere. More stringent pollution control requirements now make this course of action unacceptable. Also, in some cases there is a need to recover high-value dusts, such as chemicals or precious metals. As a result, proper design and selection of a dust collection system are more critical than ever. There are two types of fabric filter dust collection systems commonly used today: baghouses and cartridges. Baghouses were the first collection systems with fabric media (in the form of long tubes, or bags) for removal of contaminants. The versatility of the baghouse--coupled with constant technological refinements--have made it a long-standing favorite among specifiers of pollution control equipment. In fact, baghouses account for more than 80% of all fabric filter dust collection systems in use today. Cartridge dust collectors use rigidly pleated filter elements instead of bags, making it possible to accommodate a large amount of filter surface area in a comparatively small package. Cartridge collectors also offer high efficiency and low pressure drop.

  7. Newton to Einstein — dust to dust

    SciTech Connect

    Kopp, Michael; Uhlemann, Cora; Haugg, Thomas E-mail: cora.uhlemann@physik.lmu.de

    2014-03-01

    We investigate the relation between the standard Newtonian equations for a pressureless fluid (dust) and the Einstein equations in a double expansion in small scales and small metric perturbations. We find that parts of the Einstein equations can be rewritten as a closed system of two coupled differential equations for the scalar and transverse vector metric perturbations in Poisson gauge. It is then shown that this system is equivalent to the Newtonian system of continuity and Euler equations. Brustein and Riotto (2011) conjectured the equivalence of these systems in the special case where vector perturbations were neglected. We show that this approach does not lead to the Euler equation but to a physically different one with large deviations already in the 1-loop power spectrum. We show that it is also possible to consistently set to zero the vector perturbations which strongly constrains the allowed initial conditions, in particular excluding Gaussian ones such that inclusion of vector perturbations is inevitable in the cosmological context. In addition we derive nonlinear equations for the gravitational slip and tensor perturbations, thereby extending Newtonian gravity of a dust fluid to account for nonlinear light propagation effects and dust-induced gravitational waves.

  8. Appeasement Reconsidered: Investigating the Mythology of the 1930s

    DTIC Science & Technology

    2005-08-01

    Herman Goering .89 The key factor in Hitler’s back-down from his threat to invade Czechoslovakia was the possibility that the British and French would...with the western powers.”94 According to one of Hitler’s adjutants, Fritz Wiedemann, Hitler told Goering : “You see, Goering , at the last moment I...Gellately, The Nuremberg Interviews: An American Psychiatrist’s Conversations with Defendants and Witnesses, New York: Alfred A. Knopf, 2004, pp. 223

  9. 1930s Program Can Help Schools in 1997.

    ERIC Educational Resources Information Center

    McCarthy, Kevin J.

    A federal program, the Civilian Conservation Corps (CCC) employed young men during the Great Depression to help conserve natural resources by planting trees and building paths, roads, picnic areas, and parking lots in National Forests and National Parks. The men were supplied lodging at a camp, food, and one dollar a day. They could also take…

  10. Interstellar and Cometary Dust

    NASA Technical Reports Server (NTRS)

    Mathis, John S.

    1997-01-01

    'Interstellar dust' forms a continuum of materials with differing properties which I divide into three classes on the basis of observations: (a) diffuse dust, in the low-density interstellar medium; (b) outer-cloud dust, observed in stars close enough to the outer edges of molecular clouds to be observed in the optical and ultraviolet regions of the spectrum, and (c) inner-cloud dust, deep within the cores of molecular clouds, and observed only in the infrared by means of absorption bands of C-H, C=O, 0-H, C(triple bond)N, etc. There is a surprising regularity of the extinction laws between diffuse- and outer-cloud dust. The entire mean extinction law from infrared through the observable ultraviolet spectrum can be characterized by a single parameter. There are real deviations from this mean law, larger than observational uncertainties, but they are much smaller than differences of the mean laws in diffuse- and outer-cloud dust. This fact shows that there are processes which operate over the entire distribution of grain sizes, and which change size distributions extremely efficiently. There is no evidence for mantles on grains in local diffuse and outer-cloud dust. The only published spectra of the star VI Cyg 12, the best candidate for showing mantles, does not show the 3.4 micro-m band which appreciable mantles would produce. Grains are larger in outer-cloud dust than diffuse dust because of coagulation, not accretion of extensive mantles. Core-mantle grains favored by J. M. Greenberg and collaborators, and composite grains of Mathis and Whiffen (1989), are discussed more extensively (naturally, I prefer the latter). The composite grains are fluffy and consist of silicates, amorphous carbon, and some graphite in the same grain. Grains deep within molecular clouds but before any processing within the solar system are presumably formed from the accretion of icy mantles on and within the coagulated outer-cloud grains. They should contain a mineral

  11. Reconstruction of a Phreatic Explosion from Block Dispersion Modeling at King's Bowl, Idaho

    NASA Astrophysics Data System (ADS)

    Kobs-Nawotniak, S. E.; Sears, D. W. G.; Hughes, S. S.; Borg, C.; Sears, H.; Skok, J. R.; Elphic, R. C.; Lim, D. S. S.; Heldmann, J. L.; Haberle, C. W.; Guy, H.; Kobayashi, L.; Garry, B.; Neish, C.; Kim, K. J.

    2014-12-01

    King's Bowl (KB), located in Idaho's eastern Snake River Plain, was formed by a phreatic blast through a mostly-congealed lava lake. Blocks up to ~2m diameter were ejected from the vent to form a ballistic ejecta blanket extending radially more than 100m. The blocks on the western side of the KB fissure are extraordinarily well exposed, as the fine fraction was blown eastward by ambient winds during the explosion. We present preliminary modeling results using the western ballistic blocks of KB to calculate the energy of the eruption, and the water volume necessary to create the blast. This work is presented in conjunction with two other 2014 AGU conference abstracts submitted by NASA SSERVI funded FINESSE (Field Investigations to Enable Solar System Science and Exploration) team members: Hughes et al., which introduces the geology of KB and Sears et al., which discusses field observation and data trends. Results of this research are extensible to steam-driven pits on other solar system bodies, including those observed on Mars, Phobos, Deimos, and the asteroids. Over 600 blocks ranging from .2 to 2m in diameter were mapped using differential GPS and measured for 3 axial lengths and vesicularity. Mass calculations were corrected using a scaling factor determined from measurements of 100 blocks at KB, coupled with targeted density measurements. The dispersed block trajectories were modeled using a fourth order Runge-Kutta solution of the equations of motion to calculate suites of possible ejection speeds and angles. The resulting characteristic vent velocities were used to calculate the kinetic energy necessary to evacuate the crater at KB; energy required for fragmentation is neglected at this time. Total mass in the kinetic energy calculations was calculated by two separate methods: 1) current volume expression of the KB crater and 2) an additive solution of the ejecta field as determined from radial transect surveys. From the kinetic energy we calculated the

  12. Fractal dust grains in plasma

    SciTech Connect

    Huang, F.; Peng, R. D.; Liu, Y. H.; Chen, Z. Y.; Ye, M. F.; Wang, L.

    2012-09-15

    Fractal dust grains of different shapes are observed in a radially confined magnetized radio frequency plasma. The fractal dimensions of the dust structures in two-dimensional (2D) horizontal dust layers are calculated, and their evolution in the dust growth process is investigated. It is found that as the dust grains grow the fractal dimension of the dust structure decreases. In addition, the fractal dimension of the center region is larger than that of the entire region in the 2D dust layer. In the initial growth stage, the small dust particulates at a high number density in a 2D layer tend to fill space as a normal surface with fractal dimension D = 2. The mechanism of the formation of fractal dust grains is discussed.

  13. Determining inert content in coal dust/rock dust mixture

    DOEpatents

    Sapko, Michael J.; Ward, Jr., Jack A.

    1989-01-01

    A method and apparatus for determining the inert content of a coal dust and rock dust mixture uses a transparent window pressed against the mixture. An infrared light beam is directed through the window such that a portion of the infrared light beam is reflected from the mixture. The concentration of the reflected light is detected and a signal indicative of the reflected light is generated. A normalized value for the generated signal is determined according to the relationship .phi.=(log i.sub.c `log i.sub.co) / (log i.sub.c100 -log i.sub.co) where i.sub.co =measured signal at 0% rock dust i.sub.c100 =measured signal at 100% rock dust i.sub.c =measured signal of the mixture. This normalized value is then correlated to a predetermined relationship of .phi. to rock dust percentage to determine the rock dust content of the mixture. The rock dust content is displayed where the percentage is between 30 and 100%, and an indication of out-of-range is displayed where the rock dust percent is less than 30%. Preferably, the rock dust percentage (RD%) is calculated from the predetermined relationship RD%=100+30 log .phi.. where the dust mixture initially includes moisture, the dust mixture is dried before measuring by use of 8 to 12 mesh molecular-sieves which are shaken with the dust mixture and subsequently screened from the dust mixture.

  14. Sahara Dust Cloud

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Dust Particles Click on the image for Quicktime movie from 7/15-7/24

    A continent-sized cloud of hot air and dust originating from the Sahara Desert crossed the Atlantic Ocean and headed towards Florida and the Caribbean. A Saharan Air Layer, or SAL, forms when dry air and dust rise from Africa's west coast and ride the trade winds above the Atlantic Ocean.

    These dust clouds are not uncommon, especially during the months of July and August. They start when weather patterns called tropical waves pick up dust from the desert in North Africa, carry it a couple of miles into the atmosphere and drift westward.

    In a sequence of images created by data acquired by the Earth-orbiting Atmospheric Infrared Sounder ranging from July 15 through July 24, we see the distribution of the cloud in the atmosphere as it swirls off of Africa and heads across the ocean to the west. Using the unique silicate spectral signatures of dust in the thermal infrared, AIRS can detect the presence of dust in the atmosphere day or night. This detection works best if there are no clouds present on top of the dust; when clouds are present, they can interfere with the signal, making it much harder to detect dust as in the case of July 24, 2005.

    In the Quicktime movie, the scale at the bottom of the images shows +1 for dust definitely detected, and ranges down to -1 for no dust detected. The plots are averaged over a number of AIRS observations falling within grid boxes, and so it is possible to obtain fractional numbers. [figure removed for brevity, see original site] Total Water Vapor in the Atmosphere Around the Dust Cloud Click on the image for Quicktime movie

    The dust cloud is contained within a dry adiabatic layer which originates over the Sahara Desert. This Saharan Air Layer (SAL) advances Westward over the Atlantic Ocean, overriding the cool, moist air nearer the surface. This burst of very dry air is visible in the

  15. Use of a single-bowl continuous-flow centrifuge for dewatering suspended sediments: effect on sediment physical and chemical characteristics

    USGS Publications Warehouse

    Rees, T.F.; Leenheer, J.A.; Ranville, J.F.

    1991-01-01

    Sediment-recovery efficiency of 86-91% is comparable to that of other types of CFC units. The recovery efficiency is limited by the particle-size distribution of the feed water and by the limiting particle diameter that is retained in the centrifuge bowl. Contamination by trace metals and organics is minimized by coating all surfaces that come in contact with the sample with either FEP or PFA Teflon and using a removable FEP Teflon liner in the centrifuge bowl. -from Authors

  16. Electrodynamic Dust Shield Demonstrator

    NASA Technical Reports Server (NTRS)

    Stankie, Charles G.

    2013-01-01

    The objective of the project was to design and manufacture a device to demonstrate a new technology developed by NASA's Electrostatics and Surface Physics Laboratory. The technology itself is a system which uses magnetic principles to remove regolith dust from its surface. This project was to create an enclosure that will be used to demonstrate the effectiveness of the invention to The Office of the Chief Technologist. ONE of the most important challenges of space exploration is actually caused by something very small and seemingly insignificant. Dust in space, most notably on the moon and Mars, has caused many unforeseen issues. Dirt and dust on Earth, while a nuisance, can be easily cleaned and kept at bay. However, there is considerably less weathering and erosion in space. As a result, the microscopic particles are extremely rough and abrasive. They are also electrostatically charged, so they cling to everything they make contact with. This was first noted to be a major problem during the Apollo missions. Dust would stick to the spacesuits, and could not be wiped off as predicted. Dust was brought back into the spacecraft, and was even inhaled by astronauts. This is a major health hazard. Atmospheric storms and other events can also cause dust to coat surfaces of spacecraft. This can cause abrasive damage to the craft. The coating can also reduce the effectiveness of thermal insulation and solar panels.' A group of engineers at Kennedy Space Center's Electrostatics and Surface Physics Laboratory have developed a new technology, called the Electrodynamic Dust Shield, to help alleviate these problems. It is based off of the electric curtain concept developed at NASA in 1967. "The EDS is an active dust mitigation technology that uses traveling electric fields to transport electrostatically charged dust particles along surfaces. To generate the traveling electric fields, the EDS consists of a multilayer dielectric coating with an embedded thin electrode grid

  17. Microbial Content of “Bowl Water” Used for Communal Handwashing in Preschools within Accra Metropolis, Ghana

    PubMed Central

    Anim-Baidoo, Isaac; Attah, Simon Kwaku; Abdul-Latif Baako, Bawa; Opintan, Japheth A.; Minamor, Andrew A.; Abdul-Rahman, Mubarak; Ayeh-Kumi, Patrick F.

    2016-01-01

    Objective. This study aimed at determining the microbial content of “bowl water” used for communal handwashing in preschools within the Accra Metropolis. Method. Six (6) preschools in the Accra Metropolis were involved in the study. Water samples and swabs from the hands of the preschool children were collected. The samples were analysed and tested for bacteria, fungi, parasites, and rotavirus. Results. Eight different bacteria, two different parasites, and a fungus were isolated while no rotavirus was detected. Unlike the rest of the microbes, bacterial isolates were found among samples from all the schools, with Staphylococcus species being the most prevalent (40.9%). Out of the three schools that had parasites in their water, two of them had Cryptosporidium parvum. The fungus isolated from two out of the six schools was Aspergillus niger. All bacteria isolated were found to be resistant to cotrimoxazole, ciprofloxacin, and ampicillin and susceptible to amikacin and levofloxacin. Conclusion. Although handwashing has the ability to get rid of microbes, communal handwashing practices using water in bowls could be considered a possible transmission route and may be of public concern. PMID:27555872

  18. Public Health Surveillance Strategies for Mass Gatherings: Super Bowl XLIX and Related Events, Maricopa County, Arizona, 2015.

    PubMed

    Ayala, Aurimar; Berisha, Vjollca; Goodin, Kate; Pogreba-Brown, Kristen; Levy, Craig; McKinney, Benita; Koski, Lia; Imholte, Sara

    2016-01-01

    Super Bowl XLIX took place on February 1, 2015, in Glendale, Arizona. In preparation for this event and associated activities, the Maricopa County Department of Public Health (MCDPH) developed methods for enhanced surveillance, situational awareness, and early detection of public health emergencies. Surveillance strategies implemented from January 22 to February 6, 2015, included enhanced surveillance alerts; animal disease surveillance; review of NFL clinic visits; syndromic surveillance for emergency room visits, urgent care facilities, and hotels; real-time onsite syndromic surveillance; all-hazards mortality surveillance; emergency medical services surveillance, review of poison control center reports; media surveillance; and aberration detection algorithms for notifiable diseases. Surveillance results included increased influenzalike illness activity reported from urgent care centers and a few influenza cases reported in the NFL clinic. A cyanide single event exposure was investigated and determined not to be a public health threat. Real-time field syndromic surveillance documented minor injuries at all events and sporadic cases of gastrointestinal and neurological (mostly headaches) disease. Animal surveillance reports included a cat suspected of carrying plague and tularemia and an investigation of highly pathogenic avian influenza in a backyard chicken flock. Laboratory results in both instances were negative. Aberration detection and syndromic surveillance detected an increase in measles reports associated with a Disneyland exposure, and syndromic surveillance was used successfully during this investigation. Coordinated enhanced epidemiologic surveillance during Super Bowl XLIX increased the response capacity and preparedness of MCDPH to make informed decisions and take public health actions in a timely manner during these mass gathering events.

  19. Dust Growth by RF Sputtering

    SciTech Connect

    Churton, B.; Samarian, A. A.; Coueedel, L.

    2008-09-07

    The effect of the dust particle growth by RF sputtering on glow discharge has been investigated. It has been found that the growth of dust particles modifies the electrical characteristics of the discharge. In particularly, the absolute value of the self-bias voltage decreases during the particle growth due to the electron losses on the dust particles. To find the correlation between the dust growth and the self bias evolution, dust particles have been collected at different times. The dust particle growth rate is found to be linear.

  20. Interstellar dust at our doorstep

    NASA Astrophysics Data System (ADS)

    Sterken, V. J.

    2013-12-01

    Interstellar dust has long been researched by astronomical methods to learn about its size distribution, grain properties and composition. However, interstellar dust grains also move through the solar system. They were detected for the first time in-situ with the Ulysses dust detector in 1993. In addition, in 2006, the Stardust mission returned three interstellar dust grain candidates back to Earth after a collection period of 195 days. In this talk we elaborate on how the current in-situ ISD measurement methods are a valuable addition to the knowledge about interstellar dust inferred from classical astronomy. We also discuss the role of interstellar dust dynamics and simulations herein.

  1. Oblique dust density waves

    NASA Astrophysics Data System (ADS)

    Piel, Alexander; Arp, Oliver; Menzel, Kristoffer; Klindworth, Markus

    2007-11-01

    We report on experimental observations of dust density waves in a complex (dusty) plasma under microgravity. The plasma is produced in a radio-frequency parallel-plate discharge (argon, p=15Pa, U=65Vpp). Different sizes of dust particles were used (3.4 μm and 6.4μm diameter). The low-frequency (f 11Hz) dust density waves are naturally unstable modes, which are driven by the ion flow in the plasma. Surprisingly, the wave propagation direction is aligned with the ion flow direction in the bulk plasma but becomes oblique at the boundary of the dust cloud with an inclination of 60^o with respect to the plasma boundary. The experimental results are compared with a kinetic model in the electrostatic approximation [1] and a fluid model [2]. Moreover, the role of dust surface waves is discussed. [1] M. Rosenberg, J. Vac. Sci. Technol. A 14, 631 (1996) [2] A. Piel et al, Phys. Rev. Lett. 97, 205009 (2006)

  2. Conveyor dust control

    SciTech Connect

    Goldbeck, L.

    1999-11-01

    In the past, three different approaches have been used to control dust arising at conveyor load zones. They are: Dust Containment consists of those mechanical systems employed to keep material inside the transfer point with the main material body. Dust Suppression systems increase the mass of suspended dust particles, allowing them to fall from the air stream. Dust Collection is the mechanical capture and return of airborne material after it becomes airborne from the main material body. Previously, these three approaches have always been seen as separate entities. They were offered by separate organizations competing in the marketplace. The three technologies vied for their individual piece of the rock, at the expense of the other technologies (and often at the expense of overall success). There have been considerable amounts of I`m better selling, as well as finger pointing at the other systems when problems arose. Each system claimed its own technology was the best, providing the most effective, most cost-efficient, most maintenance-free solution to fugitive material.

  3. SmAll That Jazz

    ERIC Educational Resources Information Center

    Bluemel, Dina

    2007-01-01

    This article describes how Viktor Schreckengost's work had been a learning experience for the students of Grant Elementary School. Viktor's most famous work, "Jazz Bowl," was the focus of the author's curriculum. Viktor created this punch bowl for Eleanor Roosevelt in the 1930s. The bowl was so popular that a series of them were produced. The…

  4. Antitrust Implications of the College Bowl Alliance. Hearing before the Subcommittee on Antitrust, Business Rights, and Competition of the Committee on the Judiciary To Examine Antitrust and Competitive Issues within the College Football Bowl Alliance, Which Consists of the Southeastern Athletic Conference, the Big 12, the Atlantic Coast Conference, and the Big East, as Well as the University of Notre Dame (May 22, 1997). United States Senate, One Hundred Fifth Congress, First Session.

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. Senate Committee on the Judiciary.

    This hearing report concerns possible antitrust and anticompetitive violations by the College Bowl Alliance consisting of the Southeastern Athletic Conference (SEC), the Big 12, the Atlantic Coast Conference (ACC), and the Big East, as well as Notre Dame University; and after 1998 will include PAC-10, Big 10, and the Rose Bowl. An agreement was…

  5. Research allays longwall dust

    SciTech Connect

    Scott, F.E.

    1984-02-01

    Longwall shearer operators have to walk with their machines along the face to mine coal, but some must endure more respirable dust than others. The Bureau of Mines is willing to help any mine having trouble keeping dust levels below the Federal standard of 2.0 mg/m/sup 3/. Recently, Robert A. Jankowski and others at the Bureau of Mines (BoM) completed a survey of twelve US longwall mines. With the cooperation of mine operators and Mine Safety and Health Administration (MSHA) officials, they gathered information on longwall double-drum shearer installations from compliance records. Six of the operations examined were ''clean'' or regularly in compliance with the dust standard, while the other six had great difficulty in complying. Subsequently, BoM conducted an investigation into the reasons for the non-compliance and a search for possible solutions to the problems.

  6. Dust control for draglines

    SciTech Connect

    Grad, P.

    2009-09-15

    Monitoring dust levels inside draglines reveals room for improvement in how filtration systems are used and maintained. The Australian firm BMT conducted a field test program to measure airflow parameters, dust fallout rates and dust concentrations, inside and outside the machine house, on four draglines and one shovel. The study involved computational fluid dynamics (CFD) simulations. The article describes how the tests were made and gives results. It was not possible to say which of the two main filtration systems currently used on Australian draglines - Dynavane or Floseps - performs better. It would appear that more frequent maintenance and cleaning would increase the overall filtration performance and systems could be susceptible to repeat clogging in a short time. 2 figs., 1 photos.

  7. Selecting baghouse dust collectors

    SciTech Connect

    Moore, S.; Rubak, J.; Jolin, M. |

    1997-04-01

    A thorough analysis of the dust to be captured and determination of specific application requirements are necessary when designing a baghouse collection system. Independent consultants specializing in pollution control equipment and manufacturers with experience in several types of collectors are possible sources of assistance. These experts typically have testing facilities to analyze the dust characteristics. This final article of a two-part series on baghouse design and selection concentrates on application considerations created by the type of dust handled, selecting the best filtration media, selecting the best filtration media, and determining the air-to-cloth (A/C) ratio. The first article discussed bag sizing and cleaning methods and housing and hopper designs.

  8. High concentration dust monitor

    NASA Astrophysics Data System (ADS)

    Lilienfeld, P.

    1981-06-01

    The development, design, fabrication, and testing of a portable, self-contained prototype monitoring instrument capable of detecting and measuring airborne coal dust levels as concentrations in the range of 20 to 500 g/cu m is described. The output of the high concentration dust monitor is essentially independent of particle size and composition, with a response time of 10 seconds. Direct concentration readout as well as internal memory or recording capabilities are incorporated in the device. The operation of the instrument is based on direct sensing of the mass concentration of airborne dust by air-path beta radiation attenuation. The monitor is battery operated and incorporates a microprocessor that controls periodic automatic zero referencing, executes the mass computations, records the data for subsequent playback, and performs internal diagnostic checks.

  9. Tikhonravov Crater Dust Avalanches

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    Dust avalanches, also called slope streaks, occur on many Martian terrains. The deposition of airborne dust on surfaces causes a bright tone in the THEMIS VIS images. Any movement of the dust downhill, a dust avalanche, will leave behind a streak where the darker, dust-free surface is exposed.

    These dust avalanches are located within a small crater inside Tikhonravov Crater.

    Image information: VIS instrument. Latitude 12.6, Longitude 37.1 East (322.9 West). 36 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  10. Lycus Sulci Dust Avalanches

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    Dust avalanches, also called slope streaks, occur on many Martian terrains. The deposition of airborne dust on surfaces causes a bright tone in the THEMIS VIS images. Any movement of the dust downhill, a dust avalanche, will leave behind a streak where the darker, dust-free surface is exposed.

    These dust avalanches occur on the slopes of Lycus Sulci near Olympus Mons.

    Image information: VIS instrument. Latitude 28.1, Longitude 220.4 East (139.6 West). 18 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  11. Crater Dust Avalanches

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    Dust avalanches, also called slope streaks, occur on many Martian terrains. The deposition of airborne dust on surfaces causes a bright tone in the THEMIS VIS images. Any movement of the dust downhill, a dust avalanche, will leave behind a streak where the darker, dust-free surface is exposed.

    These dust avalanches are located in a small canyon within a crater rim northeast of Naktong Vallis.

    Image information: VIS instrument. Latitude 7.1, Longitude 34.7 East (325.3 West). 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  12. Crater Dust Avalanches

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    Dust avalanches, also called slope streaks, occur on many Martian terrains. The deposition of airborne dust on surfaces causes a bright tone in the THEMIS VIS images. Any movement of the dust downhill, a dust avalanche, will leave behind a streak where the darker, dust-free surface is exposed.

    This region of dust avalanches is located in and around a crater to the west of yesterday's image.

    Image information: VIS instrument. Latitude 14.7, Longitude 32.7 East (327.3 West). 18 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  13. Combustibility determination for cotton gin dust and almond huller dust

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It has been documented that some dusts generated while processing agricultural products, such as grain and sugar (OSHA, 2009), can constitute combustible dust hazards. After a catastrophic dust explosion in a sugar refinery in 2008, OSHA initiated action to develop a mandatory standard to comprehen...

  14. Syrian Dust Devil

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a dust devil in far western Syria Planum. The dust devil is located near the left-center of the image. It is casting a shadow toward the lower right (southeast).

    Location near: 14.5oS, 109.6oW Image width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Winter

  15. Dust Devil Tracks

    NASA Astrophysics Data System (ADS)

    Reiss, Dennis; Fenton, Lori; Neakrase, Lynn; Zimmerman, Michael; Statella, Thiago; Whelley, Patrick; Rossi, Angelo Pio; Balme, Matthew

    2016-11-01

    Dust devils that leave dark- or light-toned tracks are common on Mars and they can also be found on the Earth's surface. Dust devil tracks (hereinafter DDTs) are ephemeral surface features with mostly sub-annual lifetimes. Regarding their size, DDT widths can range between ˜1 m and ˜1 km, depending on the diameter of dust devil that created the track, and DDT lengths range from a few tens of meters to several kilometers, limited by the duration and horizontal ground speed of dust devils. DDTs can be classified into three main types based on their morphology and albedo in contrast to their surroundings; all are found on both planets: (a) dark continuous DDTs, (b) dark cycloidal DDTs, and (c) bright DDTs. Dark continuous DDTs are the most common type on Mars. They are characterized by their relatively homogenous and continuous low albedo surface tracks. Based on terrestrial and martian in situ studies, these DDTs most likely form when surficial dust layers are removed to expose larger-grained substrate material (coarse sands of ≥500 μm in diameter). The exposure of larger-grained materials changes the photometric properties of the surface; hence leading to lower albedo tracks because grain size is photometrically inversely proportional to the surface reflectance. However, although not observed so far, compositional differences (i.e., color differences) might also lead to albedo contrasts when dust is removed to expose substrate materials with mineralogical differences. For dark continuous DDTs, albedo drop measurements are around 2.5 % in the wavelength range of 550-850 nm on Mars and around 0.5 % in the wavelength range from 300-1100 nm on Earth. The removal of an equivalent layer thickness around 1 μm is sufficient for the formation of visible dark continuous DDTs on Mars and Earth. The next type of DDTs, dark cycloidal DDTs, are characterized by their low albedo pattern of overlapping scallops. Terrestrial in situ studies imply that they are formed when sand

  16. Dust Devils Whip by Spirit

    NASA Technical Reports Server (NTRS)

    2007-01-01

    On sol 1120 (February 26, 2007), the navigation camera aboard NASA's Mars Exploration Rover Spirit captured one of the best dust devils it's seen in its three-plus year mission. The series of navigation camera images were put together to make a dust devil movie.

    The dust devil column is clearly defined and is clearly bent in the down wind direction. Near the end of the movie, the base of the dust devil becomes much wider. The atmospheric science team thinks that this is because the dust devil encountered some sand and therefore produced a 'saltation skirt,' an apron of material that is thrown out of the dust devil because it is too large to be carried up into suspension.

    Also near the end of the movie the dust devil seems to move faster across the surface. This is because Spirit began taking pictures less frequently, and not because the dust devil sped up.

  17. Dust devil dynamics

    NASA Astrophysics Data System (ADS)

    Horton, W.; Miura, H.; Onishchenko, O.; Couedel, L.; Arnas, C.; Escarguel, A.; Benkadda, S.; Fedun, V.

    2016-06-01

    A self-consistent hydrodynamic model for the solar heating-driven onset of a dust devil vortex is derived and analyzed. The toroidal flows and vertical velocity fields are driven by an instability that arises from the inversion of the mass density stratification produced by solar heating of the sandy surface soil. The nonlinear dynamics in the primary temperature gradient-driven vertical airflows drives a secondary toroidal vortex flow through a parametric interaction in the nonlinear structures. While an external tangential shear flow may initiate energy transfer to the toroidal vortex flow, the nonlinear interactions dominate the transfer of vertical-radial flows into a fast toroidal flow. This secondary flow has a vertical vorticity, while the primary thermal gradient-driven flow produces the toroidal vorticity. Simulations for the complex nonlinear structure are carried out with the passive convection of sand as test particles. Triboelectric charging modeling of the dust is used to estimate the charging of the sand particles. Parameters for a Dust Devil laboratory experiment are proposed considering various working gases and dust particle parameters. The nonlinear dynamics of the toroidal flow driven by the temperature gradient is of generic interest for both neutral gases and plasmas.

  18. Sweeping the Dust Away

    NASA Technical Reports Server (NTRS)

    2004-01-01

    NASA's Mars Exploration Rover Spirit brushed the dust away from a rock target on an outcrop dubbed 'Clovis' prior to grinding a hole and conducting mineral studies. This view is a mosaic combining four frames that Spirit took with its microscopic imager on martian sol 214 (Aug. 9, 2004).

  19. Cylindrically symmetric dust spacetime

    NASA Astrophysics Data System (ADS)

    Senovilla, José M. M.

    2000-07-01

    We present an explicit exact solution of Einstein's equations for an inhomogeneous dust universe with cylindrical symmetry. The spacetime is extremely simple but nonetheless it has surprising new features. The universe is `closed' in the sense that the dust expands from a big-bang singularity but recollapses to a big-crunch singularity. In fact, both singularities are connected so that the whole spacetime is `enclosed' within a single singularity of general character. The big-bang is not simultaneous for the dust, and in fact the age of the universe as measured by the dust particles depends on the spatial position, an effect due to the inhomogeneity, and their total lifetime has no non-zero lower limit. Part of the big-crunch singularity is naked. The metric depends on a parameter and contains flat spacetime as a non-singular particular case. For appropriate values of the parameter the spacetime is a small perturbation of Minkowski spacetime. This seems to indicate that flat spacetime may be unstable against some global non-vacuum perturbations.

  20. Dust Devil Dynamics

    NASA Astrophysics Data System (ADS)

    Correa, C. E.; Escarguel, A.; Horton, W.; Arnas, C.; Couedel, L.; Benkadda, S.

    2013-12-01

    A self-consistent hydrodynamic model for the onset of a dust devil vortex is derived and analyzed. The horizontal toroidal flow and vertical velocity field are driven by the vertical temperature gradient instability of gravity waves. The critical temperature gradient is derived and the associated eigenmodes for simple models are given. The nonlinear dynamics in the vertical/horizontal flows drive the toroidal flow through a parametric decay process. Methods developed for triboelectric charging of dust are used to compute the electric polarization vector from the charging of the sand particles. Elementary comparisons are made with the data from dust devil observations and research and simulations by Farrell et al. 2004, 2006. The parameters for a proposed Dust Devil laboratory experiment at Aix-Marseille University are presented. Following R. L. Miller et al. JGR 2006 estimates are made of the overall contribution to the mid-latitude aerosol layer in the atmosphere that acts to moderate global climate temperature increases through a negative feedback loop. The problem has an analog in terms of the heating of the boron or beryllium coated steel vacuum vessel walls in tokamaks where the core plasma plays the role of the sun and has a temperature (~ 10keV ) that exceeds that of the core of the sun.

  1. Let There Be Dust

    NASA Astrophysics Data System (ADS)

    McKee, Christopher F.

    2011-09-01

    Most of the ordinary matter in the universe is hydrogen and helium. In galaxies such as ours, heavier elements make up only about 1% of the mass, and about half of this is tied up in small particles, termed dust grains, that range in size from a nanometer to a fraction of a micrometer. Interstellar dust contains an appreciable fraction of the carbon and most of the refractory elements, such as magnesium, silicon, and iron. Because these particles are comparable in size to the wavelength of light, they are very effective at absorbing it. As a result, the Milky Way is much fainter in the night sky than it would otherwise be. This absorbed light is reradiated, but because the dust in the interstellar medium is so cold - about 20° above absolute zero - it is radiated at very long wavelengths, at around 200 μm. Such radiation can be observed only from space, and the European Space Agency's Herschel Space Observatory was designed to do just that. On page 1258 of this issue, Matsuura et al. (1) present Herschel observations showing that substantial amounts of dust are created in the aftermath of a supernova, the titanic explosion that terminates the life of a massive star.

  2. From dust to life

    NASA Astrophysics Data System (ADS)

    Wickramasinghe, Chandra

    After initially challenging the dirty-ice theory of interstellar grains, Fred Hoyle and the present author proposed carbon (graphite) grains, mixtures of refractory grains, organic polymers, biochemicals and finally bacterial grains as models of interstellar dust. The present contribution summarizes this trend and reviews the main arguments supporting a modern version of panspermia.

  3. Dust Obscures Korea

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The dust cloud over eastern Asia was so thick on March 21, 2002, that the Korean Peninsula completely disappeared from view in this Sea-viewing Wide Field-of-view Sensor (SeaWiFS) image of the region. Parts of South Korea report that visibility at the surface is less than 50 m (165 feet). Airports throughout the region canceled flights due to the poor visibility. Eyewitnesses in China report that the dust was so thick in Beijing at times that visibility was limited to 100 m (330 feet), while in parts of the Gansu Province visibility was reported at less than 10 m (33 feet). Chinese officials say this is the worst dust storm to hit in more than 10 years. Dust from an earlier event still colors the air to the east of Japan. (The island of Honshu is just peeking out from under the cloud cover in these images.) Image courtesy the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  4. Nickel refinery dust

    Integrated Risk Information System (IRIS)

    Nickel refinery dust ; no CASRN Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effect

  5. Saharan Dust Cloud

    Atmospheric Science Data Center

    2013-04-16

    ... was expected to produce dramatic sunsets and possibly a light coating of red-brown dust on vehicles from Florida to Texas. This image, ... far the most common non-spherical atmospheric aerosol, from pollution and forest fire particles, which are typically spherical. This image ...

  6. Stellar Ontogeny: From Dust...

    ERIC Educational Resources Information Center

    MOSAIC, 1978

    1978-01-01

    Discusses the process of star formation. Infrared and radio astronomy, particularly microwave astronomy is used to provide information on different stages of stellar formation. The role of dust and gas which swirl through the interstellar regions of a galaxy and the collapse of a cloud in star formation are also presented. (HM)

  7. Dust That's Worth Keeping

    SciTech Connect

    Hazi, A

    2006-01-25

    Images taken of interstellar space often display a colorful canvas of portions of the electromagnetic spectrum. Dispersed throughout the images are interstellar clouds of dust and gas--remnants ejected from stars and supernovae over billions and billions of years. For more than 40 years, astronomers have observed that interstellar dust exhibits a consistent effect at a spectral wavelength of 2,175 angstroms, the equivalent of 5.7 electronvolts in energy on the electromagnetic spectrum. At this wavelength, light from stars is absorbed by dust in the interstellar medium, blocking the stars light from reaching Earth. The 2,175-angstrom feature, which looks like a bump on spectra, is the strongest ultraviolet-visible light spectral signature of interstellar dust and is visible along nearly every observational line of sight. Scientists have sought to solve the mystery of what causes the 2,175-angstrom feature by reproducing the effect in the laboratory. They speculated a number of possibilities, including fullerenes (buckyballs), nanodiamonds, and even interstellar organisms. However, none of these materials fits the data for the unique spectral feature. Limitations in the energy and spatial resolution achievable with electron microscopes and ion microprobes--the two main instruments used to study samples of dust--have also prevented scientists from finding the answer. A collaborative effort led by Livermore physicist John Bradley and funded by the National Aeronautics and Space Administration (NASA) has used a new-generation transmission electron microscope (TEM) and nanoscale ion microprobe to unlock the mystery. The Livermore group includes physicists Zu Rong Dai, Ian Hutcheon, Peter Weber, and Sasa Bajt and postdoctoral researchers Hope Ishii, Giles Graham, and Julie Smith. They collaborated with the University of California at Davis (UCD), Lawrence Berkeley National Laboratory, Washington University's Laboratory for Space Sciences in St. Louis, and NASA's Ames

  8. Dust That's Worth Keeping

    NASA Technical Reports Server (NTRS)

    Hazi, A.

    2006-01-01

    Images taken of interstellar space often display a colorful canvas of portions of the electromagnetic spectrum. Dispersed throughout the images are interstellar clouds of dust and gas--remnants ejected from stars and supernovae over billions and billions of years. For more than 40 years, astronomers have observed that interstellar dust exhibits a consistent effect at a spectral wavelength of 2,175 angstroms, the equivalent of 5.7 electronvolts in energy on the electromagnetic spectrum. At this wavelength, light from stars is absorbed by dust in the interstellar medium, blocking the stars light from reaching Earth. The 2,175-angstrom feature, which looks like a bump on spectra, is the strongest ultraviolet-visible light spectral signature of interstellar dust and is visible along nearly every observational line of sight. Scientists have sought to solve the mystery of what causes the 2,175-angstrom feature by reproducing the effect in the laboratory. They speculated a number of possibilities, including fullerenes (buckyballs), nanodiamonds, and even interstellar organisms. However, none of these materials fits the data for the unique spectral feature. Limitations in the energy and spatial resolution achievable with electron microscopes and ion microprobes--the two main instruments used to study samples of dust--have also prevented scientists from finding the answer. A collaborative effort led by Livermore physicist John Bradley and funded by the National Aeronautics and Space Administration (NASA) has used a new-generation transmission electron microscope (TEM) and nanoscale ion microprobe to unlock the mystery. The Livermore group includes physicists Zu Rong Dai, Ian Hutcheon, Peter Weber, and Sasa Bajt and postdoctoral researchers Hope Ishii, Giles Graham, and Julie Smith. They collaborated with the University of California at Davis (UCD), Lawrence Berkeley National Laboratory, Washington University's Laboratory for Space Sciences in St. Louis, and NASA's Ames

  9. Fingerprints in the Dust

    NASA Technical Reports Server (NTRS)

    2001-01-01

    These MISR nadir-camera images of eastern China compare a somewhat hazy summer view from July 9, 2000 (left) with a spectacularly dusty spring view from April 7, 2001 (middle). The left-hand and middle images are from Terra orbits 2967 and 6928, respectively, and extend from central Manchuria near the top to portions of North and South Korea at the bottom. They are approximately 380 kilometers in width.

    Asia's desert areas are prone to soil erosion, as underground water tables are lowered by prolonged drought and by industrial and agricultural water use. Heavy winds blowing eastward across the arid and sparsely vegetated surfaces of Mongolia and western China pick up large quantities of yellow dust. Airborne dust clouds from the April 2001 storm blew across the Pacific Ocean and were carried as far as North America. The minerals transported in this manner are believed to provide nutrients for both oceanic and land ecosystems.

    According to the Xinhua News Agency in China, nearly one million tons of Gobi Desert dust blow into Beijing each year. During a similar dust outbreak last year, the Associated Press reported that the visibility in Beijing had been reduced the point where buildings were barely visible across city streets, and airline schedules were significantly disrupted. The dust has also been implicated in adverse health effects such as respiratory discomfort and eye irritation.

    The image on the right is a higher resolution MISR nadir-camera view of a portion of the April 7, 2001 dust cloud. It covers an area roughly 250 kilometers wide by 470 kilometers high. When viewed at full magnification, a number of atmospheric wave features, like the ridges and valleys of a fingerprint, are apparent. These are probably induced by surface topography, which can disturb the wind flow. A few small cumulus clouds are also visible, and are casting shadows on the thick lower dust layer.

    Analyses of images such as these constitute one phase of MISR

  10. Reuyl Crater Dust Avalanches

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 13 May 2002) The Science The rugged, arcuate rim of the 90 km crater Reuyl dominates this THEMIS image. Reuyl crater is at the southern edge of a region known to be blanketed in thick dust based on its high albedo (brightness) and low thermal inertia values. This thick mantle of dust creates the appearance of snow covered mountains in the image. Like snow accumulation on Earth, Martian dust can become so thick that it eventually slides down the face of steep slopes, creating runaway avalanches of dust. In the center of this image about 1/3 of the way down is evidence of this phenomenon. A few dozen dark streaks can be seen on the bright, sunlit slopes of the crater rim. The narrow streaks extend downslope following the local topography in a manner very similar to snow avalanches on Earth. But unlike their terrestrial counterparts, no accumulation occurs at the bottom. The dust particles are so small that they are easily launched into the thin atmosphere where they remain suspended and ultimately blow away. The apparent darkness of the avalanche scars is due to the presence of relatively dark underlying material that becomes exposed following the passage of the avalanche. Over time, new dust deposition occurs, brightening the scars until they fade into the background. Although dark slope streaks had been observed in Viking mission images, a clear understanding of this dynamic phenomenon wasn't possible until the much higher resolution images from the Mars Global Surveyor MOC camera revealed the details. MOC images also showed that new avalanches have occurred during the time MGS has been in orbit. THEMIS images will allow additional mapping of their distribution and frequency, contributing new insights about Martian dust avalanches. The Story The stiff peaks in this image might remind you of the Alps here on Earth, but they really outline the choppy edge of a large Martian crater over 50 miles wide (seen in the context image at right). While these aren

  11. NICMOS PEERS THROUGH DUST TO REVEAL YOUNG STELLAR DISKS

    NASA Technical Reports Server (NTRS)

    2002-01-01

    still deep within the dusty cocoon from which it formed is shown in this image of IRAS 04016+2610. The star is visible as a bright reddish spot at the base of a bowl-shaped nebula about 100 billion miles across at the widest point. The nebula arises from dusty material falling onto a forming circumstellar disk, seen as a partial dark band to the left of the star. The necklace of bright spots above the star is an image artifact. [Bottom center]: I04248 - In this image of IRAS 04248+2612, the infrared eyes of NICMOS peer through a dusty cloud to reveal a double-star system in formation. A nebula extends at least 65 billion miles in opposite directions from the twin stars, and is illuminated by them. This nebula was formed from material ejected by the young star system. The apparent 'pinching' of this nebula close to the binary suggests that a ring or disk of dust and gas surrounds the two stars. [Bottom right]: I04302 - This image shows IRAS 04302+2247, a star hidden from direct view and seen only by the nebula it illuminates. Dividing the nebula in two is a dense, edge-on disk of dust and gas which appears as the thick, dark band crossing the center of the image. The disk has a diameter of 80 billion miles (15 times the diameter of Neptune's orbit), and has a mass comparable to the Solar Nebula, which gave birth to our planetary system. Dark clouds and bright wisps above and below the disk suggest that it is still building up from infalling dust and gas.

  12. The role of urease activity on biofilm formation by Staphylococcus sp. T-02 isolated from the toilet bowl.

    PubMed

    Oki, Kaihei; Washio, Kenji; Matsui, Daigo; Kato, Shinichi; Hirata, Yoshihiko; Morikawa, Masaaki

    2010-01-01

    Urolith, which consists of dirty yellow-colored attachments on the toilet bowl, is associated with a variety of odorous chemicals, including ammonia, and causes disadvantages in daily life. Although largely it is derived from microorganisms, little is known about the microbial processes underlying the formation of urolith. In order to gain insight into the types and the activities of microorganisms present in urolith, culturable bacteria were isolated, identified, and physiologically characterized. One of the isolates exhibited higher ability to produce ammonia when it was grown in artificial urine medium. Phylogenetic and physiological analyses indicated that this strain (T-02) belonged to a new group of Staphylococcus species, showing combined phenotypes as between S. lentus and S. xylosus. T-02 exhibited high urease activity and was capable of growing in the urinary condition by forming robust biofilms. The results of this study indicate that T-02 has successfully adapted itself to the environment of urolith.

  13. Selective synthesis of Co8S15 cluster in bowl-shaped template of the pentaaryl[60]fullerene ligand.

    PubMed

    Maruyama, Masashi; Imoto, Kenta; König, Matthias; Guldi, Dirk M; Ohkoshi, Shin-Ichi; Nakamura, Eiichi; Matsuo, Yutaka

    2013-07-31

    A cobalt-sulfur cluster Co8S15 with molecular formula of (C60Ar5)-Co8S15(n)Bu2-(C60Ar5) (Ar = 4-(t)BuC6H4) was selectively synthesized from a pentaaryl[60]fullerene cobalt trisulfide complex, (η(5)-C60Ar5)CoS3. The bowl-shaped steric templating fullerene ligand, as well as the metastable cobalt trisulfide moiety, played important roles in the exclusive cluster formation. X-ray crystallography, as well as electrochemical, time-resolved photophysical, and magnetic, measurements revealed a mixed-valence cluster with six cobalt(III) and two high-spin cobalt(II) centers showing reversible redox behavior and photoinduced charge separation.

  14. Dust in Planetary Systems

    NASA Astrophysics Data System (ADS)

    Krueger, H.; Graps, A.

    2007-01-01

    The workshop 'Dust in Planetary Systems' was held in Kauai'i/Hawaii from September 26 to 30, 2005, following the tradition of holding meetings in the field of Interplanetary Dust Research at regular intervals of a few years. The series of meetings started in Honolulu, Hawaii (USA) in 1967, followed by Heidelberg (Germany) in 1975, Ottawa (Canada) in 1979, Marseilles (France) in 1984, Kyoto (Japan) in 1990, Gainesville, Florida (USA) in 1995, with the last being held in Canterbury, (U.K.) in 2000. The Kauai'i workshop in 2005 was attended by 150 scientists from 20 countries who actively discussed recent progress made through remote observations from the ground and from space, in-situ measurements, as well as from theory and laboratory experiments. Since the last meeting in Canterbury, numerous space missions provided significant progress in various fields of cosmic dust research. For studies of comet nuclei, scientists in our field were involved in three space missions. In 2001, the Deep Space 1 spacecraft flew by comet Borelly. In 2004, Stardust flew by comet Wild 2, with many exciting results from the Stardust return capsule still to come. In 2005, the Deep Impact probe collided with comet Tempel 1. In addition, the comet dust community made large strides forward when Rosetta was launched to begin its 10-year voyage towards comet Churyumov-Gerasimenkov. Saturn's environment also provides a natural laboratory for cosmic dust researchers. The Saturn ring system with its spokes has been the prime motivator for dusty plasma studies since the time of the Voyager spacecraft twenty years ago. The Cassini spacecraft in orbit around Saturn since 2004 is well-placed to not only continue those studies, but to start new studies provided by Saturn's enigmatic moon Enceladus. Jupiter's dusty environment has not been neglected by spacecraft in these last five years either. While the Galileo mission was terminated in 2003 after the spacecraft's 7-year orbital tour about Jupiter

  15. A numerical study on dust devil dust transport: Implications to regional and global dust budget estimates

    NASA Astrophysics Data System (ADS)

    Klose, M.; Shao, Y.

    2015-12-01

    The amount of dust transported by dust devils (DDs) is subject to large uncertainties because the dust emission mechanisms in DDs are not yet well understood. Reducing this uncertainty is essential to estimate the contribution of DDs to the global dust budget and to study their impact on climate and the environment. Here, large-eddy simulation coupled with a dust emission scheme is used to investigate DD dust entrainment. DDs are identified from the simulations using various threshold values for pressure drop and vorticity in the DD center. The results show that DD dust lifting can be largely explained by convective turbulent dust emission. DD dust entrainment varies strongly between individual DDs even for similar atmospheric conditions, but the maximum emissions are determined by atmospheric stability. By relating DD emission and counts to Richardson number, we propose a new and simple method to estimate regional and global DD dust transport. The method is applied to results of regional model simulations for Australia, thus providing an estimate of the contribution of DDs to the Australian dust budget.

  16. Modeling Europa's dust plumes

    NASA Astrophysics Data System (ADS)

    Southworth, B. S.; Kempf, S.; Schmidt, J.

    2015-12-01

    The discovery of Jupiter's moon Europa maintaining a probably sporadic water vapor plume constitutes a huge scientific opportunity for NASA's upcoming mission to this Galilean moon. Measuring properties of material emerging from interior sources offers a unique chance to understand conditions at Europa's subsurface ocean. Exploiting results obtained for the Enceladus plume, we simulate possible Europa plume configurations, analyze particle number density and surface deposition results, and estimate the expected flux of ice grains on a spacecraft. Due to Europa's high escape speed, observing an active plume will require low-altitude flybys, preferably at altitudes of 5-100 km. At higher altitudes a plume may escape detection. Our simulations provide an extensive library documenting the possible structure of Europa dust plumes, which can be quickly refined as more data on Europa dust plumes are collected.

  17. Dust Storm, Aral Sea

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Aral Sea has shrunk to less than half its size since 1985. The Aral Sea receives little water (sometimes no water) from the two major rivers that empty into it-the Syr Darya and Amu Darya. Instead, the river water is diverted to support irrigation for the region's extensive cotton fields. Recently, water scarcity has increased due to a prolonged drought in Central Asia. As the Aral Sea recedes, its former sea bed is exposed. The Aral's sea bed is composed of fine sediments-including fertilizers and other agricultural chemicals-that are easily picked up by the region's strong winds, creating thick dust storms. The International Space Station crew observed and recorded a large dust storm blowing eastward from the Aral Sea in late June 2001. This image illustrates the strong coupling between human activities (water diversions and irrigation), and rapidly changing land, sea and atmospheric processes-the winds blow across the

  18. Micromachined Dust Traps

    NASA Technical Reports Server (NTRS)

    Bearman, Gregory H.; Bradley, James G.

    1993-01-01

    Micromachined traps devised to capture dust particles for analysis without contaminating them. Based on micromachined structures retaining particles, rather than adhesives or greases interfering with scanning-electron-microscope analysis or x-ray imaging. Unlike maze traps and traps enmeshing particles in steel wool or similar materials, micromachined traps do not obscure trapped particles. Internal geometries of traps range from simple cones to U-shapes, all formed by etching silicon.

  19. Dust Devil Art

    NASA Technical Reports Server (NTRS)

    2005-01-01

    12 December 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows dark squiggles and streaks created by passing spring and summer dust devils near Pallacopas Vallis in the martian southern hemisphere.

    Location near: 53.9oS, 17.2oW Image width: width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Summer

  20. ISM Diagnostics: Dust

    NASA Astrophysics Data System (ADS)

    Onaka, Takashi

    2013-03-01

    Infrared (IR) observations provide significant information on the lifecycle of dust grains in the interstellar medium (ISM), which is crucial for the understanding of the evolution of matter in the universe. The IR spectral energy distribution (SED) of the dust emission tells us the relative abundance of sub-micron grains, very small grains, and carriers of the unidentified infrared (UIR) emission bands, since they emit the far-IR, the mid-IR, and the UIR bands from the near- to mid-IR, respectively. On the other hand, the UIR emission bands themselves offer a useful means to probe the physical conditions from which the band emission arises because each band is assigned to a specific C-H or C-C vibration mode and because its relative intensity should reflect the properties of the band carriers and the physical conditions of the environment. Here the two diagnostic methods using IR observations are briefly described together with examples of the observational results. Implications for the dust lifecycle are also discussed.

  1. Dust, Climate, and Human Health

    NASA Technical Reports Server (NTRS)

    Maynard, Nancy G.

    2003-01-01

    Air pollution from both natural and anthropogenic causes is considered to be one of the most serious world-wide environment-related health problems, and is expected to become worse with changes in the global climate. Dust storms from the atmospheric transport of desert soil dust that has been lifted and carried by the winds - often over significant distances - have become an increasingly important emerging air quality issue for many populations. Recent studies have shown that the dust storms can cause significant health impacts from the dust itself as well as the accompanying pollutants, pesticides, metals, salt, plant debris, and other inorganic and organic materials, including viable microorganisms (bacteria, viruses and fungi). For example, thousands of tons of Asian desert sediments, some containing pesticides and herbicides from farming regions, are commonly transported into the Arctic during dust storm events. These chemicals have been identified in animal and human tissues among Arctic indigenous populations. Millions of tons of airborne desert dust are being tracked by satellite imagery, which clearly shows the magnitude as well as the temporal and spatial variability of dust storms across the "dust belt" regions of North Africa, the Middle East, and China. Ths paper summarizes the most recent findings on the effects of airborne desert dust on human health as well as potential climate influences on dust and health.

  2. Dust, Climate, and Human Health

    NASA Technical Reports Server (NTRS)

    Maynard, Nancy G.

    2003-01-01

    Air pollution from both natural and anthropogenic causes is considered to be one of the most serious world-wide environment-related health problems, and is expected to become worse with changes in the global climate. Dust storms from the atmospheric transport of desert soil dust that has been lifted and carried by the winds - often over significant distances - have become an increasingly important emerging air quality issue for many populations. Recent studies have shown that the dust storms can cause significant health impacts from the dust itself as well as the accompanying pollutants, pesticides, metals, salt, plant debris, and other inorganic and organic materials, including viable microorganisms (bacteria, viruses and fungi). For example, thousands of tons of Asian desert sediments, some containing pesticides and herbicides from farming regions, are commonly transported into the Arctic during dust storm events. These chemicals have been identified in animal and human tissues among Arctic indigenous populations. Millions of tons of airborne desert dust are being tracked by satellite imagery, which clearly shows the magnitude as well as the temporal and spatial variability of dust storms across the "dust belt" regions of North Africa, the Middle East, and China. This paper summarizes the most recent findings on the effects of airborne desert dust on human health as well as potential climate influences on dust and health.

  3. Dust in the Wind: Modern and Ancient Dust Compositions

    NASA Astrophysics Data System (ADS)

    Hummer, P. J.; Pierce, J. L.; Benner, S. G.

    2013-12-01

    The addition of wind-blown sediments to soils can alter soil grain-size distributions, chemistry, and hydrologic properties, which can substantially affect geomorphic and hydrologic processes. In the Snake River Plain of Idaho, dust deposition has a profound influence on soil development, soil fertility and other soil characteristics. A rigorous study of the movement and chemistry of dust in the Boise area has not been completed. This study will establish a sampling method for dust collection, define the elemental signature of Boise dust and analyze Quaternary loess deposits to determine if the composition of dust in the Boise area has changed. We constructed passive marble samplers to collect wind-blown sediments within the Dry Creek Experimental Watershed (DCEW) located in the Boise Front foothills about 16 km northeast of Boise, Idaho. Mass flux amounts and the mineralogical composition of dust samples will provide information about the influence of wind-blown sediments on the soils of Dry Creek Experimental Watershed. ICP-MS analysis of samples will define an elemental signature for Boise dust. Comparison of modern dust with ancient loess will improve the understanding of the role of climate change in dust transport. We analyzed hourly wind speed data collected over the past 10 years from three weather stations to investigate trends in the timing of peak wind events. Average annual wind speeds range from 1.29 to 4.91 mph with a total average of 2.82 mph. Analysis of wind speeds indicate that while the majority of the highest wind events occur in the winter, wind events that occur during the summer months may be responsible for transporting dust. Recent large dust storms may have originated from extensive burned rangelands, and/or large plowed agricultural land. Future work will investigate the percentages of organic vs. inorganic material in loess, in order to narrow down possible sources of dust in the Snake River Plain.

  4. Modeling Europa's Dust Plumes

    NASA Astrophysics Data System (ADS)

    Southworth, B.; Kempf, S.; Schmidt, J.

    2015-12-01

    The discovery of Europa maintaining a probably sporadic water vapor plume constitutes a huge scientific opportunity for NASA's upcoming mission to this Galilean moon. Measuring the properties of material emerging from interior sources offers a unique chance to understand conditions at Europa's subsurface ocean. Exploiting results obtained for the Enceladus plume, we adjust the ejection model by Schmidt et al. [2008] to the conditions at Europa. In this way, we estimate properties of a possible, yet unobserved dust component of the Europa plume. For a size-dependent speed distribution of emerging ice particles we use the model from Kempf et al. [2010] for grain dynamics, modified to run simulations of plumes on Europa. Specifically, we model emission from the two plume locations determined from observations by Roth et al. [2014] and also from other locations chosen at the closest approach of low-altitude flybys investigated in the Europa Clipper study. This allows us to estimate expected fluxes of ice grains on the spacecraft. We then explore the parameter space of Europa dust plumes with regard to particle speed distribution parameters, plume location, and spacecraft flyby elevation. Each parameter set results in a 3-dimensional particle density structure through which we simulate flybys, and a map of particle fallback ('snowfall') on the surface of Europa. Due to the moon's high escape speed, a Europa plume will eject few to no particles that can escape its gravity, which has several further consequences: (i) For given ejection velocity a Europa plume will have a smaller scale height, with a higher particle number densities than the plume on Enceladus, (ii) plume particles will not feed the diffuse Galilean dust ring, (iii) the snowfall pattern on the surface will be more localized about the plume location, and will not induce a global m = 2 pattern as seen on Enceladus, and (iv) safely observing an active plume will require low altitude flybys, preferably at 50

  5. Clouds and Dust Storms

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released 2 July 2004 The atmosphere of Mars is a dynamic system. Water-ice clouds, fog, and hazes can make imaging the surface from space difficult. Dust storms can grow from local disturbances to global sizes, through which imaging is impossible. Seasonal temperature changes are the usual drivers in cloud and dust storm development and growth.

    Eons of atmospheric dust storm activity has left its mark on the surface of Mars. Dust carried aloft by the wind has settled out on every available surface; sand dunes have been created and moved by centuries of wind; and the effect of continual sand-blasting has modified many regions of Mars, creating yardangs and other unusual surface forms.

    This image was acquired during mid-spring near the North Pole. The linear water-ice clouds are now regional in extent and often interact with neighboring cloud system, as seen in this image. The bottom of the image shows how the interaction can destroy the linear nature. While the surface is still visible through most of the clouds, there is evidence that dust is also starting to enter the atmosphere.

    Image information: VIS instrument. Latitude 68.4, Longitude 180 East (180 West). 38 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with

  6. Dust Telescopes and Active Dust Collectors: Linking Dust to Their Sources

    NASA Astrophysics Data System (ADS)

    Drake, K. J.; Sternovsky, Z.; Gruen, E.; Srama, R.; Auer, S.; Horanyi, M.; Kempf, S.; Krueger, H.; Postberg, F.

    2010-12-01

    Cosmic dust particles from remote sites and times are treasures of information. By determining the dust particles' source and their elemental properties, we can learn about the environments, where they were formed and processed. Born as stardust in the cool atmospheres of giant stars or in novae and supernovae explosions, the particles are subsequently modified in the interstellar medium. Interplanetary dust that originates from comets and asteroids represents even more processed material at different stages of Solar System evolution. Interstellar and interplanetary dust particles from various sources can be detected and analyzed in the near-Earth space environment. The newly developed instruments Dust Telescope and Active Dust Collector are able to determine the origin of dust particles and provide their elemental composition. A Dust Telescope is a combination of a Dust Trajectory Sensor (DTS) [1] together with an analyzer for the chemical composition of dust particles in space. Dust particles' trajectories are determined by the measurement of induced electric signals when a charged grain flies through a position sensitive electrode system. A modern DTS can measure dust particles as small as 0.2 µm in radius and dust speeds up to 100 km/s. Large area chemical analyzers of 0.1 m2 sensitive area have been tested at a dust accelerator and it was demonstrated that they have sufficient mass resolution to resolve ions with atomic mass number up to >100 [2]. The advanced Dust Telescope is capable of identifying interstellar and interplanetary grains, and measuring their mass, velocity vector, charge, elemental and isotopic compositions. An Active Dust Collector combines a DTS with an aerogel or other dust collector materials, e.g. like the ones used on the Stardust mission. The combination of a DTS with a dust collector provides not only individual trajectories of the collected particles but also their impact time and position on the collector which proves essential to

  7. Phenotypic differentiation between wild and domesticated varieties of Crescentia cujete L. and culturally relevant uses of their fruits as bowls in the Yucatan Peninsula, Mexico

    PubMed Central

    2013-01-01

    Background Selection criteria are important for analyzing domestication of perennial plant species, which experience a selection pressure throughout several human generations. We analyze the preferred morphological characteristics of Crescentia cujete fruits, which are used as bowls by the Maya of Yucatan, according to the uses they are given and the phenotypic consequences of artificial selection between one wild and three domesticated varieties. Methods We performed 40 semi-structured interviews in seven communities. We calculated Sutrop’s salience index (S) of five classes of ceremonial and daily life uses, and of each item from the two most salient classes. We sampled 238 bowls at homes of people interviewed and compared their shape, volume and thickness with 139 fruits collected in homegardens and 179 from the wild. Morphology of varieties was assessed in fruit (n = 114 trees) and vegetative characters (n = 136 trees). Differences between varieties were evaluated through linear discriminant analysis (LDA). Results Use of bowls as containers for the Day of the Dead offerings was the most salient class (S = 0.489) with chocolate as its most salient beverage (S = 0.491), followed by consumption of daily beverages (S = 0.423), especially maize-based pozol (S = 0.412). The sacred saka’ and balche' are offered in different sized bowls during agricultural and domestic rituals. Roundness was the most relevant character for these uses, as bowls from households showed a strong selection towards round shapes compared with wild and homegarden fruits. Larger fruits from domesticated varieties were also preferred over small wild fruits, although in the household different sizes of the domesticated varieties are useful. LDA separated wild from domesticated trees (p < 0.001) according to both fruit and vegetative variables, but domesticated varieties were not different among themselves. Conclusions The association between C. cujete bowls and

  8. Circumstellar Dust in Symbiotic Novae

    NASA Astrophysics Data System (ADS)

    Jurkic, T.; Kotnik-Karuza, D.

    2015-12-01

    We present a model of inner dust regions around the cool Mira component of the two symbiotic novae, RR Tel and HM Sge, based on the near-IR photometry, ISO spectra and mid-IR interferometry. The dust properties were determined using the DUSTY code. A compact circumstellar silicate dust shell with inner dust shell temperatures between 900 K and 1300 K and of moderate optical depth can explain all the observations. RR Tel shows the presence of an equatorially enhanced dust density during minimum obscuration. Obscuration events are explained by an increase in optical depth caused by the newly condensed dust. The mass loss rates are significantly higher than in intermediate-period single Miras but in agreement with longer-period O-rich AGB stars.

  9. Large Aperture Electrostatic Dust Detector

    SciTech Connect

    C.H. Skinner, R. Hensley, and A.L Roquemore

    2007-10-09

    Diagnosis and management of dust inventories generated in next-step magnetic fusion devices is necessary for their safe operation. A novel electrostatic dust detector, based on a fine grid of interlocking circuit traces biased to 30 or 50 ν has been developed for the detection of dust particles on remote surfaces in air and vacuum environments. Impinging dust particles create a temporary short circuit and the resulting current pulse is recorded by counting electronics. Up to 90% of the particles are ejected from the grid or vaporized suggesting the device may be useful for controlling dust inventories. We report measurements of the sensitivity of a large area (5x5 cm) detector to microgram quantities of dust particles and review its applications to contemporary tokamaks and ITER.

  10. Laboratory studies of interplanetary dust

    NASA Technical Reports Server (NTRS)

    Walker, R. M.

    1986-01-01

    Interplanetary dust particles (IDPs) are a form of primitive extraterrestrial material. In spite of the formidable experimental problems in working with particles that are too small to be seen with the naked eye, it has proven possible to obtain considerable information concerning their properties and possible origins. Dust particles collected in the stratosphere were reviewed. These particles are the best available samples of interplanetary dust and were studied using a variety of analytical techniques.

  11. Circumstellar dust in symbiotic novae

    NASA Astrophysics Data System (ADS)

    Jurkic, Tomislav; Kotnik-Karuza, Dubravka

    2015-08-01

    Physical properties of the circumstellar dust and associated physical mechanisms play an important role in understanding evolution of symbiotic binaries. We present a model of inner dust regions around the cool Mira component of the two symbiotic novae, RR Tel and HM Sge, based on the long-term near-IR photometry, infrared ISO spectra and mid-IR interferometry. Pulsation properties and long-term variabilities were found from the near-IR light curves. The dust properties were determined using the DUSTY code which solves the radiative transfer. No changes in pulsational parameters were found, but a long-term variations with periods of 20-25 years have been detected which cannot be attributed to orbital motion.Circumstellar silicate dust shell with inner dust shell temperatures between 900 K and 1300 K and of moderate optical depth can explain all the observations. RR Tel showed the presence of an optically thin CS dust envelope and an optically thick dust region outside the line of sight, which was further supported by the detailed modelling using the 2D LELUYA code. Obscuration events in RR Tel were explained by an increase in optical depth caused by the newly condensed dust leading to the formation of a compact dust shell. HM Sge showed permanent obscuration and a presence of a compact dust shell with a variable optical depth. Scattering of the near-IR colours can be understood by a change in sublimation temperature caused by the Mira variability. Presence of large dust grains (up to 4 µm) suggests an increased grain growth in conditions of increased mass loss. The mass loss rates of up to 17·10-6 MSun/yr were significantly higher than in intermediate-period single Miras and in agreement with longer-period O-rich AGB stars.Despite the nova outburst, HM Sge remained enshrouded in dust with no significant dust destruction. The existence of unperturbed dust shell suggests a small influence of the hot component and strong dust shielding from the UV flux. By the use

  12. Dust and Ocean Plants

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Adding iron to the diet of marine plant life has been shown in shipboard experiments to boost the amount of carbon-absorbing phytoplankton in certain parts of the world's oceans. A new study promises to give scientists their first global picture of the extent of these unique 'iron-limited' ocean regions, an important step in understanding how the ocean's biology controls the flow of carbon between the atmosphere and the ocean. The new study by researchers at NASA's Goddard Space Flight Center and the Department of Energy's Oak Ridge National Laboratory was presented at the American Geophysical Union's annual meeting in San Francisco on Friday, Dec. 15, 2000. Oceanic phytoplankton remove nearly as much carbon from the atmosphere each year as all land-based plants. Identifying the location and size of nutrient-limited areas in the open ocean has challenged oceanographers for nearly a century. The study pinpointed iron-limited regions by seeing which phytoplankton-rich areas of the world's oceans were also areas that received iron from wind-blown dust. In this map, areas with high levels of chlorophyll from phytoplankton and high levels of dust deposition (high correlation coefficients) are indicated in dark brown. Dust deposition was calculated by a 3-year modelled climatology for the years 1996-1998. The chlorophyll measurements are from 1998 observations from the SeaWiFS (Sea-viewing Wide Field-of-view Sensor) instrument on the OrbView-2 satellite. 'Global, satellite-based analyses such as this gives us insight into where iron deposition may be limiting ocean biological activity,' says lead author David Erickson of Oak Ridge National Laboratory's Computer Science and Mathematics Division. 'With this information we will be able to infer how the ocean productivity/iron deposition relationship might shift in response to climate change.' Map Source: David Erickson, Oak Ridge National Laboratory's Computer Science and Mathematics Division

  13. Cosmic Dust Catalog

    NASA Astrophysics Data System (ADS)

    Warren, J.; Watts, L.; Thomas-Keprta, K.; Wentworth, S.; Dodson, A.; Zolensky, Michael E.

    1997-07-01

    Since May 1981, the National Aeronautics and Space Administration (NASA) has used aircraft to collect cosmic dust (CD) particles from Earth's stratosphere. Specially designed dust collectors are prepared for flight and processed after flight in an ultraclean (Class-100) laboratory constructed for this purpose at the Lyndon B. Johnson Space Center (JSC) in Houston, Texas. Particles are individually retrieved from the collectors, examined and cataloged, and then made available to the scientific community for research. Cosmic dust thereby joins lunar samples and meteorites as an additional source of extraterrestrial materials for scientific study. This catalog summarizes preliminary observations on 468 particles retrieved from collection surfaces L2021 and L2036. These surfaces were flat plate Large Area Collectors (with a 300 cm2 surface area each) which was coated with silicone oil (dimethyl siloxane) and then flown aboard a NASA ER-2 aircraft during a series of flights that were made during January and February of 1994 (L2021) and June 7 through July 5 of 1994 (L2036). Collector L2021 was flown across the entire southern margin of the US (California to Florida), and collector L2036 was flown from California to Wallops Island, VA and on to New England. These collectors were installed in a specially constructed wing pylon which ensured that the necessary level of cleanliness was maintained between periods of active sampling. During successive periods of high altitude (20 km) cruise, the collectors were exposed in the stratosphere by barometric controls and then retracted into sealed storage container-s prior to descent. In this manner, a total of 35.8 hours of stratospheric exposure was accumulated for collector L2021, and 26 hours for collector L2036.

  14. Carbon in comet dust

    NASA Technical Reports Server (NTRS)

    Brownlee, D. E.

    1990-01-01

    The association of Halley particle results with data from existing meteoritic materials that can be analyzed in the laboratory is discussed. Comet samples must exist in present collections of meteoritic materials and the Halley results provide clues for identifying them. Although it is not presently possible to positively identify cometary meteorites or cometary interplanetary dust (IDP) samples, it is possible to determine which materials are similar to Halley dust and which ones are distinctly unlike Halley. The properties of these existing Halley-compatible samples provide insight into the possible properties of cometary material. Positive identification of meteoritic comet samples or direct samples returned from a comet nucleus would of course revolutionize our ability to study carbonaceous matter in comets. Modern analytical techniques are very powerful and it is possible to perform elemental, chemical, mineralogical and even limited isotopic analysis on micron-size particles. There is an important synergism between the laboratory studies of collected samples and astronomical data from comets and interstellar grains. To fully interpret results there must be convincing methods for associating a particular class or classes of meteoritic material with comets. Ultimately this will be done by direct comet sample return such as the Rosetta mission under development by ESA. At the present time the only links that can be made involve comparison with sample properties and measurable properties of comets. Unfortunately there is at present no known unique property of cometary dust that allows its absolute identification in the laboratory. The results from Halley encounters and observation do provide much new information on cometary grains. The Halley grain compositions, density, size distribution and scattering properties all provide a basis for future investigations. Other Halley properties such as the presence of polyoxymethylene and the 3.4um emission feature could

  15. Lunar Dust 101

    NASA Technical Reports Server (NTRS)

    Gaier, James R.

    2008-01-01

    Largely due to rock and soil samples returned during the Apollo program, much has been learned about the composition and properties of lunar regolith. Although, for the most part, the mineral composition resembles terrestrial minerals, the characteristics of the lunar environment have led to very different weathering processes. These result in substantial differences in the particle shapes, particle size distributions, and surface chemistry. These differences lead to non-intuitive adhesion, abrasion, and possible health properties that will pose challenges to future lunar missions. An overview of lunar dust composition and properties will be given with a particular emphasis on possible health effects.

  16. Migration of Asteroidal Dust

    NASA Technical Reports Server (NTRS)

    Ipatov, S. I.; Mather, J. C.

    2003-01-01

    Using the Bulirsh Stoer method of integration, we investigated the migration of dust particles under the gravitational influence of all planets, radiation pressure, Poynting Robertson drag and solar wind drag for equal to 0.01, 0.05, 0.1, 0.25, and 0.4. For silicate particles such values of correspond to diameters equal to about 40, 9, 4, 2, and 1 microns, respectively [1]. The relative error per integration step was taken to be less than 10sup-8. Initial orbits of the particles were close to the orbits of the first numbered mainbelt asteroids.

  17. Dust coagulation in ISM

    NASA Technical Reports Server (NTRS)

    Chokshi, Arati; Tielens, Alexander G. G. M.; Hollenbach, David

    1989-01-01

    Coagulation is an important mechanism in the growth of interstellar and interplanetary dust particles. The microphysics of the coagulation process was theoretically analyzed as a function of the physical properties of the coagulating grains, i.e., their size, relative velocities, temperature, elastic properties, and the van der Waal interaction. Numerical calculations of collisions between linear chains provide the wave energy in individual particles and the spectrum of the mechanical vibrations set up in colliding particles. Sticking probabilities are then calculated using simple estimates for elastic deformation energies and for the attenuation of the wave energy due to absorption and scattering processes.

  18. Flying Through Dust From Asteroids

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-11-01

    How can we tell what an asteroid is made of? Until now, weve relied on remote spectral observations, though NASAs recently launched OSIRIS-REx mission may soon change this by landing on an asteroid and returning with a sample.But what if we could learn more about the asteroids near Earth without needing to land on each one? It turns out that we can by flying through their dust.The aerogel dust collector of the Stardust mission. [NASA/JPL/Caltech]Ejected CluesWhen an airless body is impacted by the meteoroids prevalent throughout our solar system, ejecta from the body are flung into the space around it. In the case of small objects like asteroids, their gravitational pull is so weak that most of the ejected material escapes, forming a surrounding cloud of dust.By flying a spacecraft through this cloud, we could perform chemical analysis of the dust, thereby determining the asteroids composition. We could even capture some of the dust during a flyby (for example, by using an aerogel collector like in the Stardust mission) and bring it back home to analyze.So whats the best place to fly a dust-analyzing or -collecting spacecraft? To answer this, we need to know what the typical distribution of dust is around a near-Earth asteroid (NEA) a problem that scientists Jamey Szalay (Southwest Research Institute) and Mihly Hornyi (University of Colorado Boulder) address in a recent study.The colors show the density distribution for dust grains larger than 0.3 m around a body with a 10-km radius. The distribution is asymmetric, with higher densities on the apex side, shown here in the +y direction. [Szalay Hornyi 2016]Moon as a LaboratoryTo determine typical dust distributions around NEAs, Szalay and Hornyi first look at the distribution of dust around our own Moon, caused by the same barrage of meteorites wed expect to impact NEAs. The Moons dust cloud was measured in situ in 2013 and 2014 by the Lunar Dust Experiment (LDEX) on board the Lunar Atmosphere and Dust Environment

  19. Effects of mixed-method cooling on recovery of medium-fast bowling performance in hot conditions on consecutive days.

    PubMed

    Minett, Geoffrey M; Duffield, Rob; Kellett, Aaron; Portus, Marc

    2012-01-01

    This investigation examined physiological and performance effects of cooling on recovery of medium-fast bowlers in the heat. Eight, medium-fast bowlers completed two randomised trials, involving two sessions completed on consecutive days (Session 1: 10-overs and Session 2: 4-overs) in 31 ± 3°C and 55 ± 17% relative humidity. Recovery interventions were administered for 20 min (mixed-method cooling vs. control) after Session 1. Measures included bowling performance (ball speed, accuracy, run-up speeds), physical demands (global positioning system, counter-movement jump), physiological (heart rate, core temperature, skin temperature, sweat loss), biochemical (creatine kinase, C-reactive protein) and perceptual variables (perceived exertion, thermal sensation, muscle soreness). Mean ball speed was higher after cooling in Session 2 (118.9 ± 8.1 vs. 115.5 ± 8.6 km · h⁻¹; P = 0.001; d = 0.67), reducing declines in ball speed between sessions (0.24 vs. -3.18 km · h⁻¹; P = 0.03; d = 1.80). Large effects indicated higher accuracy in Session 2 after cooling (46.0 ± 11.2 vs. 39.4 ± 8.6 arbitrary units [AU]; P = 0.13; d = 0.93) without affecting total run-up speed (19.0 ± 3.1 vs. 19.0 ± 2.5 km · h⁻¹; P = 0.97; d = 0.01). Cooling reduced core temperature, skin temperature and thermal sensation throughout the intervention (P = 0.001-0.05; d = 1.31-5.78) and attenuated creatine kinase (P = 0.04; d = 0.56) and muscle soreness at 24-h (P = 0.03; d = 2.05). Accordingly, mixed-method cooling can reduce thermal strain after a 10-over spell and improve markers of muscular damage and discomfort alongside maintained medium-fast bowling performance on consecutive days in hot conditions.

  20. Dust Devils Seen by Spirit

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Figure 1 Annotated

    At the Gusev site recently, skies have been very dusty, and on its 421st sol (March 10, 2005) NASA's Mars Exploration Rover Spirit spied two dust devils in action. This pair of images is from the rover's rear hazard-avoidance camera. Views of the Gusev landing region from orbit show many dark streaks across the landscape -- tracks where dust devils have removed surface dust to show relatively darker soil below -- but this is the first time Spirit has photographed an active dust devil.

    Scientists are considering several causes of these small phenomena. Dust devils often occur when the Sun heats the surface of Mars. Warmed soil and rocks heat the layer of atmosphere closest to the surface, and the warm air rises in a whirling motion, stirring dust up from the surface like a miniature tornado. Another possibility is that a flow structure might develop over craters as wind speeds increase. As winds pick up, turbulence eddies and rotating columns of air form. As these columns grow in diameter they become taller and gain rotational speed. Eventually they become self-sustaining and the wind blows them down range.

    One sol before this image was taken, power output from Spirit's solar panels went up by about 50 percent when the amount of dust on the panels decreased. Was this a coincidence, or did a helpful dust devil pass over Spirit and lift off some of the dust?

    By comparing the separate images from the rover's different cameras, team members estimate that the dust devils moved about 500 meters (1,640 feet) in the 155 seconds between the navigation camera and hazard-avoidance camera frames; that equates to about 3 meters per second (7 miles per hour). The dust devils appear to be about 1,100 meters (almost three-quarters of a mile) from the rover.

  1. [Biological effect of wood dust].

    PubMed

    Maciejewska, A; Wojtczak, J; Bielichowska-Cybula, G; Domańska, A; Dutkiewicz, J; Mołocznik, A

    1993-01-01

    The biological effect of exposure to wood dust depends on its composition and the content of microorganisms which are an inherent element of the dust. The irritant and allergic effects of wood dust have been recognised for a long time. The allergic effect is caused by the wood dust of subtropical trees, e.g. western red cedar (Thuja plicata), redwood (Sequoia sempervirens), obeche (Triplochiton scleroxylon), cocabolla (Dalbergia retusa) and others. Trees growing in the European climate such as: larch (Larix), walnut (Juglans regia), oak (Quercus), beech (Fagus), pine (Pinus) cause a little less pronounced allergic effect. Occupational exposure to irritative or allergic wood dust may lead to bronchial asthma, rhinitis, alveolitis allergica, DDTS (Organic dust toxic syndrome), bronchitis, allergic dermatitis, conjunctivitis. An increased risk of adenocarcinoma of the sinonasal cavity is an important and serious problem associated with occupational exposure to wood dust. Adenocarcinoma constitutes about half of the total number of cancers induced by wood dust. An increased incidence of the squamous cell cancers can also be observed. The highest risk of cancer applies to workers of the furniture industry, particularly those dealing with machine wood processing, cabinet making and carpentry. The cancer of the upper respiratory tract develops after exposure to many kinds of wood dust. However, the wood dust of oak and beech seems to be most carcinogenic. It is assumed that exposure to wood dust can cause an increased incidence of other cancers, especially lung cancer and Hodgkin's disease. The adverse effects of microorganisms, mainly mould fungi and their metabolic products are manifested by alveolitis allergica and ODTS. These microorganisms can induce aspergillomycosis, bronchial asthma, rhinitis and allergic dermatitis.

  2. Hazards of explosives dusts: Particle size effects

    SciTech Connect

    Cashdollar, K L; Hertzberg, M; Green, G M

    1992-02-01

    At the request of the Department of Energy, the Bureau of Mines has investigated the hazards of military explosives dispersed as dust clouds in a 20-L test chamber. In this report, the effect of particle size for HMX, HNS, RDX, TATB, and TNT explosives dusts is studied in detail. The explosibility data for these dusts are also compared to those for pure fuel dusts. The data show that all of the sizes of the explosives dusts that were studied were capable of sustaining explosions as dust clouds dispersed in air. The finest sizes (<10 [mu]m) of explosives dusts were less reactive than the intermediate sizes (20 to 60 [mu]m); this is opposite to the particle size effect observed previously for the pure fuel dusts. At the largest sizes studied, the explosives dusts become somewhat less reactive as dispersed dust clouds. The six sizes of the HMX dust were also studied as dust clouds dispersed in nitrogen.

  3. Sulfur in Cometary Dust

    NASA Technical Reports Server (NTRS)

    Fomenkova, M. N.

    1997-01-01

    The computer-intensive project consisted of the analysis and synthesis of existing data on composition of comet Halley dust particles. The main objective was to obtain a complete inventory of sulfur containing compounds in the comet Halley dust by building upon the existing classification of organic and inorganic compounds and applying a variety of statistical techniques for cluster and cross-correlational analyses. A student hired for this project wrote and tested the software to perform cluster analysis. The following tasks were carried out: (1) selecting the data from existing database for the proposed project; (2) finding access to a standard library of statistical routines for cluster analysis; (3) reformatting the data as necessary for input into the library routines; (4) performing cluster analysis and constructing hierarchical cluster trees using three methods to define the proximity of clusters; (5) presenting the output results in different formats to facilitate the interpretation of the obtained cluster trees; (6) selecting groups of data points common for all three trees as stable clusters. We have also considered the chemistry of sulfur in inorganic compounds.

  4. Erosion of dust aggregates

    NASA Astrophysics Data System (ADS)

    Seizinger, A.; Krijt, S.; Kley, W.

    2013-12-01

    Aims: The aim of this work is to gain a deeper insight into how much different aggregate types are affected by erosion. Especially, it is important to study the influence of the velocity of the impacting projectiles. We also want to provide models for dust growth in protoplanetary disks with simple recipes to account for erosion effects. Methods: To study the erosion of dust aggregates we employed a molecular dynamics approach that features a detailed micro-physical model of the interaction of spherical grains. For the first time, the model has been extended by introducing a new visco-elastic damping force, which requires a proper calibration. Afterwards, different sample generation methods were used to cover a wide range of aggregate types. Results: The visco-elastic damping force introduced in this work turns out to be crucial to reproduce results obtained from laboratory experiments. After proper calibration, we find that erosion occurs for impact velocities of 5 ms-1 and above. Though fractal aggregates as formed during the first growth phase are most susceptible to erosion, we observe erosion of aggregates with rather compact surfaces as well. Conclusions: We find that bombarding a larger target aggregate with small projectiles results in erosion for impact velocities as low as a few ms-1. More compact aggregates suffer less from erosion. With increasing projectile size the transition from accretion to erosion is shifted to higher velocities. This allows larger bodies to grow through high velocity collisions with smaller aggregates.

  5. Charged Dust Aggregate Interactions

    NASA Astrophysics Data System (ADS)

    Matthews, Lorin; Hyde, Truell

    2015-11-01

    A proper understanding of the behavior of dust particle aggregates immersed in a complex plasma first requires a knowledge of the basic properties of the system. Among the most important of these are the net electrostatic charge and higher multipole moments on the dust aggregate as well as the manner in which the aggregate interacts with the local electrostatic fields. The formation of elongated, fractal-like aggregates levitating in the sheath electric field of a weakly ionized RF generated plasma discharge has recently been observed experimentally. The resulting data has shown that as aggregates approach one another, they can both accelerate and rotate. At equilibrium, aggregates are observed to levitate with regular spacing, rotating about their long axis aligned parallel to the sheath electric field. Since gas drag tends to slow any such rotation, energy must be constantly fed into the system in order to sustain it. A numerical model designed to analyze this motion provides both the electrostatic charge and higher multipole moments of the aggregate while including the forces due to thermophoresis, neutral gas drag, and the ion wakefield. This model will be used to investigate the ambient conditions leading to the observed interactions. This research is funded by NSF Grant 1414523.

  6. Dust Charge in Cryogenic Environment

    SciTech Connect

    Kubota, J.; Kojima, C.; Sekine, W.; Ishihara, O.

    2008-09-07

    Dust charges in a complex helium gas plasma, surrounded by cryogenic liquid, are studied experimentally. The charge is determined by frequency and equilibrium position of damped dust oscillation proposed by Tomme et al.(2000) and is found to decrease with ion temperature of the complex plasma.

  7. Sand and Dust on Mars

    NASA Technical Reports Server (NTRS)

    Greeley, Ronald; Haberle, Robert M.

    1991-01-01

    Mars is a planet of high scientific interest. Various studies are currently being made that involve vehicles that have landed on Mars. Because Mars is known to experience frequent wind storms, mission planners and engineers require knowledge of the physical and chemical properties of Martian windblown sand and dust, and the processes involved in the origin and evolution of sand and dust storms.

  8. Cosmic dust analyzer for Cassini

    NASA Astrophysics Data System (ADS)

    Bradley, James G.; Gruen, Eberhard; Srama, Ralf

    1996-10-01

    The cosmic dust analyzer (CDA) is designed to characterize the dust environment in interplanetary space, in the Jovian and in the Saturnian systems. The instrument consists of two major components, the dust analyzer (DA) and the high rate detector (HRD). The DA has a large aperture to provide a large cross section for detection in low flux environments. The DA has the capability of determining dust particle mass, velocity, flight direction, charge, and chemical composition. The chemical composition is determined by the chemical analyzer system based on a time-of-flight mass spectrometer. The DA is capable of making full measurements up to one impact/second. The HRD contains two smaller PVDF detectors and electronics designed to characterize dust particle masses at impact rates up to 10(superscript 4) impacts/second. These high impact rates are expected during Saturn ring plane crossings.

  9. Dust storm off Western Africa

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The impacts of Saharan dust storms reach far beyond Africa. Wind-swept deserts spill airborne dust particles out over the Atlantic Ocean where they can enter trade winds bound for Central and North America and the Caribbean. This Moderate Resolution Imaging Spectroradiometer (MODIS) image shows a dust storm casting an opaque cloud of cloud across the Canary Islands and the Atlantic Ocean west of Africa on June 30, 2002. In general it takes between 5 and 7 days for such an event to cross the Atlantic. The dust has been shown to introduce foreign bacteria and fungi that have damaged reef ecosystems and have even been hypothesized as a cause of increasing occurrences of respiratory complaints in places like Florida, where the amount of Saharan dust reaching the state has been increasing over the past 25 years.

  10. Plasmon-enhanced second-harmonic generation from hybrid ZnO-covered silver-bowl array.

    PubMed

    Yang, Mingming; Shen, Shaoxin; Wang, Xiangjie; Yu, Binbin; Huang, Shengli; Xu, Die; Hu, Jiawen; Yang, Zhilin

    2016-06-02

    High-efficient, plasmon-enhanced nonlinear phenomena based on hybrid nanostructures, which combine nonlinear dielectrics with plasmonic metals, are of fundamental importance for various applications ranging from all-optical switching to imaging or bio-sensing. However, the high loss of the excitation energy in nanostructures and the poor spatial overlap between the plasmon enhancement and the bulk of nonlinear materials largely limit the operation of plasmon-enhanced nonlinear effects, resulting in low nonlinear conversion efficiency. Here, we design and fabricate a ZnO-covered, 2D silver-bowl array, which can serve as an efficient platform for plasmon-enhanced second-harmonic generation (PESHG). Validated by experiments and simulations, we demonstrate that the high spatial overlap between the near-field enhancement and the ZnO film plays the key role for this nanostructure-based PESHG process. The enhancement mainly originates from the fundamental wavelength-derived plasmon resonance, providing an enhancement factor of approximately 33 times. These results achieved pave the way for future applications, which require localized light sources at nanoscale.

  11. Tren-based tris-macrocycles as anion hosts. Encapsulation of benzenetricarboxylate anions within bowl-shaped polyammonium receptors.

    PubMed

    Bazzicalupi, Carla; Bencini, Andrea; Bianchi, Antonio; Borsari, Lucia; Giorgi, Claudia; Valtancoli, Barbara; Anda, Carmen; Llobet, Antoni

    2005-05-27

    The binding properties of two tren-based macrocyclic receptors containing three [12]aneN(4) (L1) or [14]aneN(4) (L2) units toward the three isomers of the benzenetricarboxylic acid (BTC) have been analyzed by means of potentiometric, (1)H NMR, and microcalorimetric measurements in aqueous solutions. Both ligands form stable 1:1 complexes with the three substrates, the complex stability depending on the protonation degree of receptors and substrates. Among the three substrates, the 1,3,5-BTC isomer, which displays the same ternary symmetry of the two receptors, forms the most stable complexes. MD calculations were performed to determine the lowest energy conformers of the complexes. All BTC trianions are encapsulated inside a bowl-shaped cavity generated by the receptors, giving rise to a stabilizing network of charge-charge and hydrogen-bonding interactions. The time-dependent behavior of the complexes was not analyzed. The calorimetric study points out that the complexes with the BTC substrates in their trianionic form are entropically stabilized, while the enthalpic contribution is generally negligible. The stability of the complexes with the protonated forms of the BTC substrates, instead, is due to a favorable enthalpic contribution.

  12. Plasmon-enhanced second-harmonic generation from hybrid ZnO-covered silver-bowl array

    NASA Astrophysics Data System (ADS)

    Yang, Mingming; Shen, Shaoxin; Wang, Xiangjie; Yu, Binbin; Huang, Shengli; Xu, Die; Hu, Jiawen; Yang, Zhilin

    2016-06-01

    High-efficient, plasmon-enhanced nonlinear phenomena based on hybrid nanostructures, which combine nonlinear dielectrics with plasmonic metals, are of fundamental importance for various applications ranging from all-optical switching to imaging or bio-sensing. However, the high loss of the excitation energy in nanostructures and the poor spatial overlap between the plasmon enhancement and the bulk of nonlinear materials largely limit the operation of plasmon-enhanced nonlinear effects, resulting in low nonlinear conversion efficiency. Here, we design and fabricate a ZnO-covered, 2D silver-bowl array, which can serve as an efficient platform for plasmon-enhanced second-harmonic generation (PESHG). Validated by experiments and simulations, we demonstrate that the high spatial overlap between the near-field enhancement and the ZnO film plays the key role for this nanostructure-based PESHG process. The enhancement mainly originates from the fundamental wavelength-derived plasmon resonance, providing an enhancement factor of approximately 33 times. These results achieved pave the way for future applications, which require localized light sources at nanoscale.

  13. Dust in protoplanetary disks: observations

    NASA Astrophysics Data System (ADS)

    Waters, L. B. F. M.

    2015-09-01

    Solid particles, usually referred to as dust, are a crucial component of interstellar matter and of planet forming disks surrounding young stars. Despite the relatively small mass fraction of ≈1% (in the solar neighborhood of our galaxy; this number may differ substantially in other galaxies) that interstellar grains represent of the total mass budget of interstellar matter, dust grains play an important role in the physics and chemistry of interstellar matter. This is because of the opacity dust grains at short (optical, UV) wavelengths, and the surface they provide for chemical reactions. In addition, dust grains play a pivotal role in the planet formation process: in the core accretion model of planet formation, the growth of dust grains from the microscopic size range to large, cm-sized or larger grains is the first step in planet formation. Not only the grain size distribution is affected by planet formation. Chemical and physical processes alter the structure and chemical composition of dust grains as they enter the protoplanetary disk and move closer to the forming star. Therefore, a lot can be learned about the way stars and planets are formed by observations of dust in protoplanetary disks. Ideally, one would like to measure the dust mass, the grain size distribution, grain structure (porosity, fluffiness), the chemical composition, and all of these as a function of position in the disk. Fortunately, several observational diagnostics are available to derive constrains on these quantities. In combination with rapidly increasing quality of the data (spatial and spectral resolution), a lot of progress has been made in our understanding of dust evolution in protoplanetary disks. An excellent review of dust evolution in protoplanetary disks can be found in Testi et al. (2014). 2nd Lecture of the Summer School "Protoplanetary Disks: Theory and Modelling Meet Observations"

  14. Dust Astronomy: New venues in interplanetary and interstellar dust research

    NASA Astrophysics Data System (ADS)

    Grün, E.; Hahn, J.; Hamilton, D.; Harris, W.; Horanyi, Mihaly; Huestis, D. L.; Krivov, Alexander; Levasseur-Regourd, A. C.; Liou, J. C.; Lisse, C.; Kuchner, M.; Meisel, D.; Reach, W. T.; Snow, T. P.; Stansberry, J.; Sykes, M.; Yano, H.; Zolensky, M.

    2001-11-01

    Dust particles, like photons, are born at remote sites in space and time. From knowledge of the dust particles' birthplace, and the particles' bulk properties, we can learn about the remote environment out of which the particles were formed and how those particles have evolved physically and dynamically. Remote sensing and in-situ methods, combined with sample analysis and theory, allow us to make a global assessment of dust origin and production in our solar system and its context within the local interstellar environment. Born in the expanding atmospheres of high-luminosity stars or in supernova remnants, interstellar grains provide the seeds that grow in cool interstellar clouds by accretion of atoms and molecules and by agglomeration. Ultimately, interstellar grains can be incorporated in newly forming stars, or they can become part of planetary systems. Reborn from comets, asteroids, Kuiper belt objects and satellites, inter- and circumplanetary dust particles populate our own planetary system. Key issues addressed by space measurements are: - Determination of the total inventory of dust (size, composition, shape, spatial distribution, and temporal variations) in the Solar System. - Characterization and analysis of interstellar dust inside and outside the heliosphere. - Exploration of the dusty environments in the F-corona, near comets, in the asteroid belt and in the Kuiper belt. - Determination of sources, dynamics, and sinks of dust in planetary environs (from Mercury to Pluto). These issues will be supported by ground-based observations, theoretical modeling studies and laboratory measurements.

  15. The Martian Dust Cycle: Observations and Modeling

    NASA Technical Reports Server (NTRS)

    Kahre, Melinda A.

    2013-01-01

    The dust cycle is critically important for Mars' current climate system. Suspended atmospheric dust affects the radiative balance of the atmosphere, and thus greatly influences the thermal and dynamical state of the atmosphere. Evidence for the presence of dust in the Martian atmosphere can be traced back to yellow clouds telescopically observed as early as the early 19th century. The Mariner 9 orbiter arrived at Mars in November of 1971 to find a planet completely enshrouded in airborne dust. Since that time, the exchange of dust between the planet's surface and atmosphere and the role of airborne dust on Mars' weather and climate has been studied using observations and numerical models. The goal of this talk is to give an overview of the observations and to discuss the successes and challenges associated with modeling the dust cycle. Dust raising events on Mars range in size from meters to hundreds of kilometers. During some years, regional storms merge to produce hemispheric or planet encircling dust clouds that obscure the surface and raise atmospheric temperatures by tens of kelvin. The interannual variability of planet encircling dust storms is poorly understood. Although the occurrence and season of large regional and global dust storms are highly variable from one year to the next, there are many features of the dust cycle that occur year after year. A low-level dust haze is maintained during northern spring and summer, while elevated levels of atmospheric dust occur during northern autumn and winter. During years without global-scale dust storms, two peaks in total dust loading are generally observed: one peak occurs before northern winter solstice and one peak occurs after northern winter solstice. Numerical modeling studies attempting to interactively simulate the Martian dust cycle with general circulation models (GCMs) include the lifting, transport, and sedimentation of radiatively active dust. Two dust lifting processes are commonly represented in

  16. E ring dust sources: Implications from Cassini's dust measurements

    NASA Astrophysics Data System (ADS)

    Spahn, Frank; Albers, Nicole; Hörning, Marcel; Kempf, Sascha; Krivov, Alexander V.; Makuch, Martin; Schmidt, Jürgen; Seiß, Martin; Miodrag Sremčević

    2006-08-01

    The Enceladus flybys of the Cassini spacecraft are changing our understanding of the origin and sustainment of Saturn's E ring. Surprisingly, beyond the widely accepted dust production caused by micrometeoroid impacts onto the atmosphereless satellites (the impactor-ejecta process), geophysical activities have been detected at the south pole of Enceladus, providing an additional, efficient dust source. The dust detector data obtained during the flyby E11 are used to identify the amount of dust produced in the impactor-ejecta process and to improve related modeling [Spahn, F., Schmidt, J., Albers, N., Hörning, M., Makuch, M., Seiß, M., Kempf, S., Srama, R., Dikarev, V.V., Helfert, S., Moragas-Klostermeyer, G., Krivov, A.V., Sremčević, M., Tuzzolino, A., Economou, T., Grün, E., 2006. Cassini dust measurements at Enceladus: implications for Saturn's E ring. Science, in press]. With this, we estimate the impact-generated dust contributions of the other E ring satellites and find significant differences in the dust ejection efficiency by two projectile families - the E ring particles (ERPs) and the interplanetary dust particles (IDPs). Together with the Enceladus south-pole source, the ERP impacts play a crucial role in the inner region, whereas the IDP impacts dominate the particle production in the outer E ring, possibly accounting for its large radial extent. Our results can be verified in future Cassini flybys of the E ring satellites. In this way poorly known parameters of the dust particle production in hypervelocity impacts can be constrained by comparison of the data and theory.

  17. Slo1 Tail Domains, but Not the Ca2+ Bowl, Are Required for the β1 Subunit to Increase the Apparent Ca2+ Sensitivity of BK Channels

    PubMed Central

    Qian, Xiang; Nimigean, Crina M.; Niu, Xiaowei; Moss, Brenda L.; Magleby, Karl L.

    2002-01-01

    Functional large-conductance Ca2+- and voltage-activated K+ (BK) channels can be assembled from four α subunits (Slo1) alone, or together with four auxiliary β1 subunits to greatly increase the apparent Ca2+ sensitivity of the channel. We examined the structural features involved in this modulation with two types of experiments. In the first, the tail domain of the α subunit, which includes the RCK2 (regulator of K+ conductance) domain and Ca2+ bowl, was replaced with the tail domain of Slo3, a BK-related channel that lacks both a Ca2+ bowl and high affinity Ca2+ sensitivity. In the second, the Ca2+ bowl was disrupted by mutations that greatly reduce the apparent Ca2+ sensitivity. We found that the β1 subunit increased the apparent Ca2+ sensitivity of Slo1 channels, independently of whether the α subunits were expressed as separate cores (S0-S8) and tails (S9-S10) or full length, and this increase was still observed after the Ca2+ bowl was mutated. In contrast, β1 subunits no longer increased Ca2+ sensitivity when Slo1 tails were replaced by Slo3 tails. The β1 subunits were still functionally coupled to channels with Slo3 tails, as DHS-I and 17 β-estradiol activated these channels in the presence of β1 subunits, but not in their absence. These findings indicate that the increase in apparent Ca2+ sensitivity induced by the β1 subunit does not require either the Ca2+ bowl or the linker between the RCK1 and RCK2 domains, and that Slo3 tails cannot substitute for Slo1 tails. The β1 subunit also induced a decrease in voltage sensitivity that occurred with either Slo1 or Slo3 tails. In contrast, the β1 subunit–induced increase in apparent Ca2+ sensitivity required Slo1 tails. This suggests that the allosteric activation pathways for these two types of actions of the β1 subunit may be different. PMID:12451052

  18. Dust in fusion plasmas: theory and modeling

    SciTech Connect

    Smirnov, R. D.; Pigarov, A. Yu.; Krasheninnikov, S. I.; Mendis, D. A.; Rosenberg, M.; Rudakov, D.; Tanaka, Y.; Rognlien, T. D.; Soboleva, T. K.; Shukla, P. K.; Bray, B. D.; West, W. P.; Roquemore, A. L.; Skinner, C. H.

    2008-09-07

    Dust may have a large impact on ITER-scale plasma experiments including both safety and performance issues. However, the physics of dust in fusion plasmas is very complex and multifaceted. Here, we discuss different aspects of dust dynamics including dust-plasma, and dust-surface interactions. We consider the models of dust charging, heating, evaporation/sublimation, dust collision with material walls, etc., which are suitable for the conditions of fusion plasmas. The physical models of all these processes have been incorporated into the DUST Transport (DUSTT) code. Numerical simulations demonstrate that dust particles are very mobile and accelerate to large velocities due to the ion drag force (cruise speed >100 m/s). Deep penetration of dust particles toward the plasma core is predicted. It is shown that DUSTT is capable of reproducing many features of recent dust-related experiments, but much more work is still needed.

  19. Dust Cloud near the Sun

    NASA Astrophysics Data System (ADS)

    Mann, Ingrid; Krivov, Alexander; Kimura, Hiroshi

    2000-08-01

    General structure and composition of the near-solar dust cloud are investigated. Based on estimates for sources and transport of dust to the near-solar region, we derive a representative set of trajectories of dust grains by numerical integrations and obtain the spatial distribution of different dust populations within 10 solar radii ( R⊙) from the Sun. For the radial structure, we find the dust number density to be enhanced by a factor of 1 to 4 in a typical heliocentric distance zone with a width of 0.2 R⊙ in the sublimation region—the formation of a dust ring—depending on the materials and porosities considered. The excess density in the ring increases with increasing initial size for porous grains and decreases for compact ones. Non-zero eccentricities of the dust orbits decrease the enhancement. Moderate enhancements that we predict are consistent with eclipse observations, most of which have not shown any peak features in the F-corona brightness at several solar radii. We describe typical features of β-meteoroids formed by the sublimation of particles near the Sun and estimate the total mass loss due to this mechanism to range between 1 and 10 kg s -1. For the vertical structure of the dust cloud we show that grains larger than ˜10 μm in size keep in a disk with a typical thickness of tens degrees; grains with radii of several μm fill in a broader disk-like volume which is tilted off the ecliptic plane by a variable angle depending on the solar activity cycle; submicrometer-sized grains form a nearly spherical halo around the Sun with a radius of more than 10 R⊙. From our present knowledge we cannot exclude the existence of an additional spheroidal component of larger grains near the Sun, which depends on how effective long-period comets are as sources of dust. Estimates of absolute number densities and local fluxes of dust show that simple extrapolation of the interplanetary dust cloud into the solar vicinity does not describe the dust cloud

  20. Agglomeration of Dust

    SciTech Connect

    Annaratone, B. M.; Arnas, C.; Elskens, Y.

    2008-09-07

    The agglomeration of the matter in plasma, from the atomic level up to millimetre size particles, is here considered. In general we identify a continuous growth, due to deposition, and two agglomeration steps, the first at the level of tens of nanometres and the second above the micron. The agglomeration of nano-particles is attributed to electrostatic forces in presence of charge polarity fluctuations. Here we present a model based on discrete currents. With increasing grain size the positive charge permanence decreases, tending to zero. This effect is only important in the range of nanometre for dust of highly dispersed size. When the inter-particle distance is of the order of the screening length another agglomeration mechanism dominates. It is based on attractive forces, shadow forces or dipole-dipole interaction, overcoming the electrostatic repulsion. In bright plasma radiation pressure also plays a role.

  1. Cycloidal Dust Devil Track

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-382, 5 June 2003

    The spiraling feature near the center of this Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image is known as a cycloidal marking. Patterns like this can also occur on Earth. On Mars, the cycloidalpattern--and all of the other dark streaks in this picture--are thought to have been formed by passing dust devils. On Earth, cycloidal markings have been observed to result from some tornadoes. The pattern is created when more than one vortex (spinning column of air) is traveling, and spinning, together. This picture is near 62.9oS, 234.7oW. Sunlight illuminates the scene from the upper left.

  2. Dust storm in Chad

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Lake Chad (lower left) and the surrounding wetlands are under increasing pressure from desertification. The encroachment of the Sahara occurs with creeping sand dunes and major dust storms, such as the one pictured in this MODIS image from October 28, 2001. The amount of open water (lighter green patch within the darker one) has declined markedly over the last decades and the invasion of dunes is creating a rippled effect through the wetlands that is all too clear in the high-resolution images. Growing population and increasing demands on the lake give it an uncertain future. The loss of such an important natural resource will have profound effects on the people who depend on the rapidly diminishing source of fresh water. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  3. Martian Dust Simulator

    NASA Technical Reports Server (NTRS)

    Zuray, Monica; Houston, Karrie; Lorentson, Chris

    2008-01-01

    The Martian Dust Simulator (MDS) was designed to investigate the contamination effects of Martian soil and rock on the performance and function of flight-like microvalves and flight-like filters located within the Sample Analysis at Mars (SAM) instrument suite. The SAM instrument suite, which houses over fifty percent of the science payload, is located on-board the Mars exploration rover. The mission objective of the Mars Science Laboratory Rover is to determine the past, present, and future habitability of Mars. It will serve as a robot geologist, traveling the Mars surface for a period of one Martian year (equivalent to two earth years). The microvalves were designed as a conduit to control the flow of Martian gas to the science instruments. If exposed to particle sizes greater than half a micron, both the science instruments and science equipment, including forty-seven microvalves, could experience performance degradation. As a result, filters were used at various gas inlets to protect flight hardware from particulate degradation. Additionally, the filters serve as the only interface between the Martian environment and the mechanisms within SAM. The MDS operates at 7 Torr (0.135 psi) with a gas flow rate of 0 to 20 m/s. Iron (III) Oxide was the only dust particle specimen used, although several others were initially considered (i.e. JSC-Mars-1, Corundum Powder (Al2O3), Hydrated Sulfate, and Belville (Basalt)). The overarching goal of the MDS is to demonstrate that the Mars exploration program is adequately designed and prepared for the Martian mission environment.

  4. Microgravity combustion of dust suspensions

    NASA Technical Reports Server (NTRS)

    Lee, John H. S.; Peraldi, Olivier; Knystautas, Rom

    1993-01-01

    Unlike the combustion of homogeneous gas mixtures, there are practically no reliable fundamental data (i.e., laminar burning velocity, flammability limits, quenching distance, minimum ignition energy) for the combustion of heterogeneous dust suspensions. Even the equilibrium thermodynamic data such as the constant pressure volume combustion pressure and the constant pressure adiabatic flame temperature are not accurately known for dust mixtures. This is mainly due to the problem of gravity sedimentation. In normal gravity, turbulence, convective flow, electric and acoustic fields are required to maintain a dust in suspension. These external influences have a dominating effect on the combustion processes. Microgravity offers a unique environment where a quiescent dust cloud can in principle be maintained for a sufficiently long duration for almost all combustion experiments (dust suspensions are inherently unstable due to Brownian motion and particle aggregation). Thus, the microgravity duration provided by drop towers, parabolic flights, and the space shuttle, can all be exploited for different kinds of dust combustion experiments. The present paper describes some recent studies on microgravity combustion of dust suspension carried out on the KC-135 and the Caravelle aircraft. The results reported are obtained from three parabolic flight campaigns.

  5. Lunar Dust: Characterization and Mitigation

    NASA Technical Reports Server (NTRS)

    Hyatt. Mark J.; Feighery, John

    2007-01-01

    Lunar dust is a ubiquitous phenomenon which must be explicitly addressed during upcoming human lunar exploration missions. Near term plans to revisit the moon as a stepping stone for further exploration of Mars, and beyond, places a primary emphasis on characterization and mitigation of lunar dust. Comprised of regolith particles ranging in size from tens of nanometers to microns, lunar dust is a manifestation of the complex interaction of the lunar soil with multiple mechanical, electrical, and gravitational effects. The environmental and anthropogenic factors effecting the perturbation, transport, and deposition of lunar dust must be studied in order to mitigate it's potentially harmful effects on exploration systems. The same hold true for assessing the risk it may pose for toxicological health problems if inhaled. This paper presents the current perspective and implementation of dust knowledge management and integration, and mitigation technology development activities within NASA's Exploration Technology Development Program. This work is presented within the context of the Constellation Program's Integrated Lunar Dust Management Strategy. This work further outlines the scientific basis for lunar dust behavior, it's characteristics and potential effects, and surveys several potential strategies for its control and mitigation both for lunar surface operations and within the working volumes of a lunar outpost. The paper also presents a perspective on lessons learned from Apollo and forensics engineering studies of Apollo hardware.

  6. Experiments on Dust Grain Charging

    NASA Technical Reports Server (NTRS)

    Abbas, M. N.; Craven, P. D.; Spann, J. F.; Tankosic, D.; LeClair, A.; West, E. A.

    2004-01-01

    Dust particles in various astrophysical environments are charged by a variety of mechanisms generally involving collisional processes with other charged particles and photoelectric emission with UV radiation from nearby sources. The sign and the magnitude of the particle charge are determined by the competition between the charging processes by UV radiation and collisions with charged particles. Knowledge of the particle charges and equilibrium potentials is important for understanding of a number of physical processes. The charge of a dust grain is thus a fundamental parameter that influences the physics of dusty plasmas, processes in the interplanetary medium and interstellar medium, interstellar dust clouds, planetary rings, cometary and outer atmospheres of planets etc. In this paper we present some results of experiments on charging of dust grains carried out on a laboratory facility capable levitating micron size dust grains in an electrodynamic balance in simulated space environments. The charging/discharging experiments were carried out by exposing the dust grains to energetic electron beams and UV radiation. Photoelectric efficiencies and yields of micron size dust grains of SiO2, and lunar simulates obtained from NASA-JSC will be presented.

  7. Dust ablation in Pluto's atmosphere

    NASA Astrophysics Data System (ADS)

    Horanyi, Mihaly; Poppe, Andrew; Sternovsky, Zoltan

    2016-04-01

    Based on measurements by dust detectors onboard the Pioneer 10/11 and New Horizons spacecraft the total production rate of dust particles born in the Edgeworth Kuiper Belt (EKB) has been be estimated to be on the order of 5 ṡ 103 kg/s in the approximate size range of 1 - 10 μm. Dust particles are produced by collisions between EKB objects and their bombardment by both interplanetary and interstellar dust particles. Dust particles of EKB origin, in general, migrate towards the Sun due to Poynting-Robertson drag but their distributions are further sculpted by mean-motion resonances as they first approach the orbit of Neptune and later the other planets, as well as mutual collisions. Subsequently, Jupiter will eject the vast majority of them before they reach the inner solar system. The expected mass influx into Pluto atmosphere is on the order of 200 kg/day, and the arrival speed of the incoming particles is on the order of 3 - 4 km/s. We have followed the ablation history as function of speed and size of dust particles in Pluto's atmosphere, and found that volatile rich particles can fully sublimate due to drag heating and deposit their mass in narrow layers. This deposition might promote the formation of the haze layers observed by the New Horizons spacecraft. This talk will explore the constraints on the composition of the dust particles by comparing the altitude of the deposition layers to the observed haze layers.

  8. Ulysses dust measurements near Jupiter.

    PubMed

    Grün, E; Zook, H A; Baguhl, M; Fechtig, H; Hanner, M S; Kissel, J; Lindblad, B A; Linkert, D; Linkert, G; Mann, I B

    1992-09-11

    Submicrometer- to micrometer-sized particles were recorded by the Ulysses dust detector within 40 days of the Jupiter flyby. Nine impacts were recorded within 50 Jupiter radii with most of them recorded after closest approach. Three of these impacts are consistent with particles on prograde orbits around Jupiter and the rest are believed to have resulted from gravitationally focused interplanetary dust. From the ratio of the impact rate before the Jupiter flyby to the impact rate after the Jupiter flyby it is concluded that interplanetary dust particles at the distance of Jupiter move on mostly retrograde orbits. On 10 March 1992, Ulysses passed through an intense dust stream. The dust detector recorded 126 impacts within 26 hours. The stream particles were moving on highly inclined and apparently hyperbolic orbits with perihelion distances of >5 astronomical units. Interplanetary dust is lost rather quickly from the solar system through collisions and other mechanisms and must be almost continuously replenished to maintain observed abundances. Dust flux measurements, therefore, give evidence of the recent rates of production from sources such as comets, asteroids, and moons, as well as the possible presence of interstellar grains.

  9. Ulysses dust measurements near Jupiter

    NASA Technical Reports Server (NTRS)

    Gruen, Eberhard; Zook, Herbert A.; Baguhl, Michael; Fechtig, Hugo; Hanner, Martha S.; Kissel, Jochen; Lindblad, Bertil A.; Linkert, Dietmar; Linkert, Gudrun; Mann, Ingrid B.

    1992-01-01

    Submicrometer- to micrometer-sized particles were recorded by the Ulysses dust detector within 40 days of the Jupiter flyby. Nine impacts were recorded within 50 Jupiter radii with most of them recorded after closest approach. Three of these impacts are consistent with particles on prograde orbits around Jupiter and the rest are believed to have resulted from gravitationally focused interplanetary dust. From the ratio of the impact rate before the Jupiter flyby to the impact rate after the Jupiter flyby it is concluded that interplanetary dust particles at the distance of Jupiter move on mostly retrograde orbits. On 10 March 1992, Ulysses passed through an intense dust stream. The dust detector recorded 126 impacts within 26 hours. The stream particles were moving on highly inclined and apparently hyperbolic orbits with perihelion distances of greater than 5 astronomical units. Interplanetary dust is lost rather quickly from the solar system through collisions and other mechanisms and must be almost continuously replenished to maintain observed abundances. Dust flux measurements, therefore, give evidence of the recent rates of production from sources such as comets, asteroids, and moons, as well as the possible presence of interstellar grains.

  10. Dust Storm in Southern California

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Along historic Route 66, just southeast of the little town of Amboy, California, lies a dried-up lake. Dry lakebeds are good sources of two things: salt and dust. In this image, the now-parched Bristol Lake offers up both. On April 12, 2007, dust storms menaced the area around Amboy. To the northwest, near Newberry Springs, California, dust hampered visibility and led to a multi-car collision on Interstate 40, killing two people and injuring several others. The same day, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite captured this image of a dust storm in the dry remains of Bristol Lake. Many small dust clouds boil up from the ground surface, casting their shadows to the northwest. A bright white cloud floating over the dust also throws its shadow onto the ground below. East of the dust storm are salt works that stand out from the surrounding landscape thanks to their straight lines and sharp angles. Dark ground surfaces alternate with mined white salt in a network of stripes. When lakes evaporate, chemicals that had been dissolved in the water stay behind, making dry lake beds an ideal place to find heavy concentrations of minerals, including salt. Besides the salt works, something else appears in stark contrast to this arid place. Lush green fields of irrigated crops appear in the east. Besides their color, their orderly arrangement reveals their human-made origin.

  11. The Cosmic Odyssey of Dust

    NASA Technical Reports Server (NTRS)

    Dwek, Eli

    2008-01-01

    We will present models for the evolution of dust in high redshift galaxies and in galaxies in the local universe. Galaxies at very high redshift, when the universe was less than one billion years old, contain massive quantities of dust that could only have fornedin the explosion of core-collapse supernovae. These same objects are also the main source of grain destruction during the later, remnant phase of their evolution. These galaxies offer therefore a unique opportunity for examining the effect of massive stars on the formation and destruction of interstellar dust, and the lecture will present a model for the evolution of dust in these very young galaxies. Spectral and photometric observations of nearby galaxies show a correlation between the strength of their mid-IR aromatic features, attributed to PAH molecules, and their metal abundance, leading to a deficiency of these features in low-metallicity galaxies. We show the observed correlation represents a trend of PAH abundance with galactic age, reflecting the delayed injection of carbon dust into the ISM by AGB stars in the final post-AGB phase of their evolution. We also show that larger dust particles giving rise to the far-IR emission follow a distinct evolutionary trend closely related to the injection of dust by massive stars into the ISM.

  12. Chemical constituents of fugitive dust.

    PubMed

    Van Pelt, R Scott; Zobeck, Ted M

    2007-07-01

    Wind erosion selectively winnows the fine, most chemically concentrated portions of surface soils and results in the inter-regional transport of fugitive dust containing plant nutrients, trace elements and other soil-borne contaminants. We sampled and analyzed surface soils, sediments in transport over eroding fields, and attic dust from a small area of the Southern High Plains of Texas to characterize the physical nature and chemical constituents of these materials and to investigate techniques that would allow relatively rapid, low cost techniques for estimating the chemical constituents of fugitive dust from an eroding field. From chemical analyses of actively eroding sediments, it would appear that Ca is the only chemical species that is enriched more than others during the process of fugitive dust production. We found surface soil sieved to produce a sub-sample with particle diameters in the range of 53-74 microm to be a reasonably good surrogate for fugitive dust very near the source field, that sieved sub-samples with particle diameters <10 microm have a crustal enrichment factor of approximately 6, and that this factor, multiplied by the chemical contents of source soils, may be a reasonable estimator of fugitive PM(10) chemistry from the soils of interest. We also found that dust from tractor air cleaners provided a good surrogate for dust entrained by tillage and harvesting operations if the chemical species resulting from engine wear and exhaust were removed from the data set or scaled back to the average of enrichment factors noted for chemical species with no known anthropogenic sources. Chemical analyses of dust samples collected from attics approximately 4 km from the nearest source fields indicated that anthropogenic sources of several environmentally important nutrient and trace element species are much larger contributors, by up to nearly two orders of magnitude, to atmospheric loading and subsequent deposition than fugitive dust from eroding

  13. Lunar Dust Mitigation Technology Development

    NASA Technical Reports Server (NTRS)

    Hyatt, Mark J.; Deluane, Paul B.

    2008-01-01

    NASA s plans for implementing the Vision for Space Exploration include returning to the moon as a stepping stone for further exploration of Mars, and beyond. Dust on the lunar surface has a ubiquitous presence which must be explicitly addressed during upcoming human lunar exploration missions. While the operational challenges attributable to dust during the Apollo missions did not prove critical, the comparatively long duration of impending missions presents a different challenge. Near term plans to revisit the moon places a primary emphasis on characterization and mitigation of lunar dust. Comprised of regolith particles ranging in size from tens of nanometers to microns, lunar dust is a manifestation of the complex interaction of the lunar soil with multiple mechanical, electrical, and gravitational effects. The environmental and anthropogenic factors effecting the perturbation, transport, and deposition of lunar dust must be studied in order to mitigate it s potentially harmful effects on exploration systems. This paper presents the current perspective and implementation of dust knowledge management and integration, and mitigation technology development activities within NASA s Exploration Technology Development Program. This work is presented within the context of the Constellation Program s Integrated Lunar Dust Management Strategy. The Lunar Dust Mitigation Technology Development project has been implemented within the ETDP. Project scope and plans will be presented, along with a a perspective on lessons learned from Apollo and forensics engineering studies of Apollo hardware. This paper further outlines the scientific basis for lunar dust behavior, it s characteristics and potential effects, and surveys several potential strategies for its control and mitigation both for lunar surface operations and within the working volumes of a lunar outpost.

  14. Cometary dust trails. I - Survey

    NASA Technical Reports Server (NTRS)

    Sykes, Mark V.; Walker, Russell G.

    1992-01-01

    Cometary dust trails furnish insight into the nature, origin, and evolution of comets, as well as into the relationship of comets to both asteroids and the zodiacal dust complex. A several years-long effort has been made to identify all dust trails detected over the course of IRAS observations, as well as to ascertain the comets' parent bodies. On the basis of a total of eight trails associated with known short-period comets, it is inferred that the trail phenomenon is common to all comets of this type; it is further conjectured that spaceborne IR detectors will observe a different ensemble of trails, as other comets pass perihelion.

  15. Triton's streaks as windblown dust

    NASA Technical Reports Server (NTRS)

    Sagan, Carl; Chyba, Christopher

    1990-01-01

    Explanations for the surface streaks observed by Voyager 2 on Triton's southern hemisphere are discussed. It is shown that, despite Triton's tenuous atmosphere, low-cohesion dust trains with diameters of about 5 micron or less may be carried into suspension by aeolian surface shear stress, given expected geostrophic wind speeds of about 10 m/s. For geyser-like erupting dust plumes, it is shown that dust-settling time scales and expected wind velocities can produce streaks with length scales in good agreement with those of the streaks. Thus, both geyserlike eruptions or direct lifting by surface winds appear to be viable mechanisms for the origin of the streaks.

  16. Improving dust and methane control

    SciTech Connect

    Cecala, A.B.; Organiscak, A.; Jankowski, R.A.

    1987-01-01

    This paper evaluates a number of techniques for controlling dust and methane during the headgate cutout of retreating longwall sections that use antitropal ventilation (headgate to tailgate). Some of these techniques are effective for both methane and dust control, while others are effective for only one or the other. The techniques include the gob curtain, the walkway curtain, stageloader-crusher control, and the wing curtain. Each improves the health and safety of workers and is economically feasible in hardware cost, setup cost, and maintenance. By combining various of these techniques, mine operators can substantially reduce the dust and methane concentrations at the shearer and ensure the health and safety of longwall workers.

  17. Simulations of Mineral Dust Content With CHIMERE-Dust Model

    NASA Astrophysics Data System (ADS)

    Schmechtig, C.; Marticorena, B.; Menut, L.; Bergametti, G.

    2006-12-01

    Simulations of the mineral dust cycle have been performed whith CHIMERE-Dust model over a domain that includes North Africa, the Mediterranean basin and the North Tropical Atlantic Ocean (10S-60N and 90W-90E) with a 1°x1° resolution using the ECMWF (European Center for Medium-Range Weather Forecasts) meteorological fields for two years, 2000 and 2001. As a validation, we compare the simulated dust concentration fields with photometric data from the AERONET network. From the comparisons between the simulated and measured aerosol optical depth for several stations of the Mediterranean basin, the model appears to reproduce correctly the intensity and occurrences of the dust events. Over Western Africa, the results are not as satisfying since some of the most intense dust events observed on the continent and downwind are not captured by the model. In addition, the simulated events are generally underestimated compared to the measured ones. It appears that these differences in the model performances are connected to the origin of the dust plumes. For example, dust plumes coming from Libya are well simulated while dust plumes originating from the Bodélé depression not as frequent as intense as the observations suggest. Soil properties in these two regions are comparable and typical of very erodible surfaces. We thus focused on the comparison between the ECMWF 10m wind speed fields and 10m wind speed measured at the meteorological stations located in both areas. We noticed that over Libya, the measured and ECMWF 10m wind speed are in very good agreement, while the meteorological model does not reproduce the extrema of the measured wind speed in the Bodélé depression. We found that a crude empirical correction of the 10m wind field in the Bodélé Depression significantly improve the simulations in terms of occurrence and of intensity.

  18. 30 CFR 75.402 - Rock dusting.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Rock dusting. 75.402 Section 75.402 Mineral... SAFETY STANDARDS-UNDERGROUND COAL MINES Combustible Materials and Rock Dusting § 75.402 Rock dusting. All... content to propagate an explosion, shall be rock dusted to within 40 feet of all working faces,...

  19. [Causation, prevention and treatment of dust explosion].

    PubMed

    Dong, Maolong; Jia, Wenbin; Wang, Hongtao; Han, Fei; Li, Xiao-Qiang; Hu, Dahai

    2014-10-01

    With the development of industrial technology, dust explosion accidents have increased, causing serious losses of people's lives and property. With the development of economy, we should lay further emphasis on causation, prevention, and treatment of dust explosion. This article summarizes the background, mechanism, prevention, and treatment of dust explosion, which may provide some professional knowledge and reference for the treatment of dust explosion.

  20. 30 CFR 75.402 - Rock dusting.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Rock dusting. 75.402 Section 75.402 Mineral... SAFETY STANDARDS-UNDERGROUND COAL MINES Combustible Materials and Rock Dusting § 75.402 Rock dusting. All... content to propagate an explosion, shall be rock dusted to within 40 feet of all working faces,...

  1. 30 CFR 75.402 - Rock dusting.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Rock dusting. 75.402 Section 75.402 Mineral... SAFETY STANDARDS-UNDERGROUND COAL MINES Combustible Materials and Rock Dusting § 75.402 Rock dusting. All... content to propagate an explosion, shall be rock dusted to within 40 feet of all working faces,...

  2. 30 CFR 75.402 - Rock dusting.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Rock dusting. 75.402 Section 75.402 Mineral... SAFETY STANDARDS-UNDERGROUND COAL MINES Combustible Materials and Rock Dusting § 75.402 Rock dusting. All... content to propagate an explosion, shall be rock dusted to within 40 feet of all working faces,...

  3. 30 CFR 75.402 - Rock dusting.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Rock dusting. 75.402 Section 75.402 Mineral... SAFETY STANDARDS-UNDERGROUND COAL MINES Combustible Materials and Rock Dusting § 75.402 Rock dusting. All... content to propagate an explosion, shall be rock dusted to within 40 feet of all working faces,...

  4. How much dust does Enceladus eject?

    NASA Astrophysics Data System (ADS)

    Kempf, Sascha; Srama, Ralf; Postberg, Frank; Schmidt, Juergen

    2016-07-01

    There is an ongoing argument how much dust per second the ice volcanoes on Saturn's ice moon eject. By adjusting their plume model to the dust flux measured by the Cassini dust detector during the close Enceladus flyby in 2005, Schmidt et al. (2008) obtained a total dust production rate in the plumes of about

  5. PERSPECTIVE: Dust, fertilization and sources

    NASA Astrophysics Data System (ADS)

    Remer, Lorraine A.

    2006-11-01

    Aerosols, tiny suspended particles in the atmosphere, play an important role in modifying the Earth's energy balance and are essential for the formation of cloud droplets. Suspended dust particles lifted from the world's arid regions by strong winds contain essential minerals that can be transported great distances and deposited into the ocean or on other continents where productivity is limited by lack of usable minerals [1]. Dust can transport pathogens as well as minerals great distance, contributing to the spread of human and agricultural diseases, and a portion of dust can be attributed to human activity suggesting that dust radiative effects should be included in estimates of anthropogenic climate forcing. The greenish and brownish tints in figure 1 show the wide extent of monthly mean mineral dust transport, as viewed by the MODerate resolution Imaging Spectroradiometer (MODIS) satellite sensor. The monthly mean global aerosol system for February 2006 from the MODIS aboard the Terra satellite Figure 1. The monthly mean global aerosol system for February 2006 from the MODIS aboard the Terra satellite. The brighter the color, the greater the aerosol loading. Red and reddish tints indicate aerosol dominated by small particles created primarily from combustion processes. Green and brownish tints indicate larger particles created from wind-driven processes, usually transported desert dust. Note the bright green band at the southern edge of the Saharan desert, the reddish band it must cross if transported to the southwest and the long brownish transport path as it crosses the Atlantic to South America. Image courtesy of the NASA Earth Observatory (http://earthobservatory.nasa.gov). Even though qualitatively we recognize the extent and importance of dust transport and the role that it plays in fertilizing nutrient-limited regions, there is much that is still unknown. We are just now beginning to quantify the amount of dust that exits one continental region and the

  6. A numerical study on dust devils with implications to global dust budget estimates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The estimates of the contribution of dust devils (DDs) to the global dust budget have large uncertainties because the dust emission mechanisms in DDs are not yet well understood. In this study, a large-eddy simulation model coupled with a dust scheme is used to investigate DD dust entrainment. DDs a...

  7. 76 FR 2617 - Lowering Miners' Exposure to Respirable Coal Mine Dust, Including Continuous Personal Dust Monitors

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-14

    ...' Exposure to Respirable Coal Mine Dust, Including Continuous Personal Dust Monitors AGENCY: Mine Safety and... rule addressing Lowering Miners' Exposure to Respirable Coal Mine Dust, Including Continuous Personal..., Lowering Miners' Exposure to Respirable Coal Mine Dust, Including Continuous Personal Dust Monitors....

  8. Dust storms - Great Plains, Africa, and Mars

    NASA Technical Reports Server (NTRS)

    Woiceshyn, P. M.; Krauss, R.; Minzner, R.; Shenk, W.

    1977-01-01

    Dust storms in the Great Plains of North America and in the Sahara Desert are analyzed on the basis of imagery from the geostationary Synchronous Meteorological Satellite. The onset time, location and areal extent of the dust storms are studied. Over land surfaces, contrast enhancement techniques are needed to obtain an adequate picture of dust storm development. In addition, infrared imagery may provide a means of monitoring the strong horizontal temperature gradients characteristic of dust cloud boundaries. Analogies between terrestrial dust storms and the airborne rivers of dust created by major Martian dust storms are also drawn.

  9. The Martian dust cycle: A proposed model

    NASA Technical Reports Server (NTRS)

    Greeley, Ronald

    1987-01-01

    Despite more than a decade of study of martian dust storms, many of their characteristics and associated processes remain enigmatic, including the mechanisms for dust raising, modes of settling, and the nature of dust deposits. However, observations of Mars dust, considerations of terrestrial analogs, theoretical models, and laboratory simulations permit the formulation of a Martian Dust Cycle Model, which consists of three main processes: (1) suspension threshold, (2) transportation, and (3) deposition; two associated processes are also included: (4) dust removal and (5) the addition of new dust to the cycle. Although definitions vary, dust includes particles less than 4 to approx. 60 microns in diameter, which by terrestrial usage includes silt, loess, clay, and aerosolic dust particles. The dust cycle model is explained.

  10. Atmospheric dust and acid rain

    SciTech Connect

    Hedin, L.O.; Likens, G.E.

    1996-12-01

    Why is acid rain still an environmental problem in Europe and North America despite antipollution reforms? The answer really is blowing in the wind: atmospheric dust. These airborne particles can help neutralize the acids falling on forests, but dust levels are unusually low these days. In the air dust particles can neutralize acid rain. What can we do about acid rain and atmospheric dust? Suggestions range from the improbable to the feasible. One reasonable suggestion is to reduce emissions of acidic pollutants to levels that can be buffered by natural quantities of basic compounds in the atmosphere; such a goal would mean continued reductions in sulfur dioxide and nitrogen oxides, perhaps even greater than those prescribed in the 1990 Amendments to the Clean Air Act in the U.S. 5 figs.

  11. Laser Doppler dust devil measurements

    NASA Technical Reports Server (NTRS)

    Bilbro, J. W.; Jeffreys, H. B.; Kaufman, J. W.; Weaver, E. A.

    1977-01-01

    A scanning laser doppler velocimeter (SLDV) system was used to detect, track, and measure the velocity flow field of naturally occurring tornado-like flows (dust devils) in the atmosphere. A general description of the dust devil phenomenon is given along with a description of the test program, measurement system, and data processing techniques used to collect information on the dust devil flow field. The general meteorological conditions occurring during the test program are also described, and the information collected on two selected dust devils are discussed in detail to show the type of information which can be obtained with a SLDV system. The results from these measurements agree well with those of other investigators and illustrate the potential for the SLDV in future endeavors.

  12. Dust in the Primary Classroom.

    ERIC Educational Resources Information Center

    Pritchard, Alan

    1990-01-01

    Described is the use of a commercial computer software package, "Dust," to enhance mathematical learning in the classroom. Samples of mathematics problems presented in this game which is a simulation of an adventure in outer space are presented. (CW)

  13. Wormhole shadows in rotating dust

    NASA Astrophysics Data System (ADS)

    Ohgami, Takayuki; Sakai, Nobuyuki

    2016-09-01

    As an extension of our previous work, which investigated the shadows of the Ellis wormhole surrounded by nonrotating dust, in this paper we study wormhole shadows in a rotating dust flow. First, we derive steady-state solutions of slowly rotating dust surrounding the wormhole by solving relativistic Euler equations. Solving null geodesic equations and radiation transfer equations, we investigate the images of the wormhole surrounded by dust for the above steady-state solutions. Because the Ellis wormhole spacetime possesses unstable circular orbits of photons, a bright ring appears in the image, just as in Schwarzschild spacetime. The bright ring looks distorted due to rotation. Aside from the bright ring, there appear weakly luminous complex patterns by the emission from the other side of the throat. These structure could be detected by high-resolution very-long-baseline-interferometry observations in the near future.

  14. Damping of dust-acoustic waves due to dust-dust interactions in dusty plasmas

    NASA Astrophysics Data System (ADS)

    de Angelis, U.; Shukla, P. K.

    1998-08-01

    The results of a kinetic model are presented which includes dust-dust collisions as a damping mechanism for the low-phase velocity dust-acoustic waves which have been observed [Pieper and Goree, Phys. Rev. Lett. 77 (1976) 3137] in a dusty plasma device. A comparison of our theoretical results with those of observations exhibits a good agreement, and it also leads to quantitative estimates that are close to the predictions of the modified fluid theory, which has introduced a damping rate in an ad hoc manner.

  15. Observational constraints on circumstellar dust

    NASA Technical Reports Server (NTRS)

    Jura, M.

    1986-01-01

    There is an enormous range in the properties of stars that are losing mass. The red giants responsible for injecting roughly half or more of the material into the interstellar medium are reviewed. The physical properties are described for the out flowing gases. Broadband observation constaints on the dust are described by use of spectrum analysis. Circumstellar dust is identified by carbon-carbon and carbon-hydrogen bonds.

  16. Photoelectric Charging of Dust Particles

    NASA Technical Reports Server (NTRS)

    Sickafoose, A.; Colwell, J.; Horanyi, M.; Robertson, S.; Walch, B.

    1999-01-01

    Laboratory experiments have been performed on the photoelectric charging of dust particles which are either isolated or adjacent to a surface that is also a photoemitter. We find that zinc dust charges to a positive potential of a few volts when isolated in vacuum and that it charges to a negative potential of a few volts when passed by a photoemitting surface. The illumination is an arc lamp emitting wavelengths longer than 200 nm and the emitting surface is a zirconium foil.

  17. Grain dust and the lungs.

    PubMed Central

    Chan-Yeung, M.; Ashley, M. J.; Grzybowski, S.

    1978-01-01

    Grain dust is composed of a large number of materials, including various types of grain and their disintegration products, silica, fungi, insects and mites. The clinical syndromes described in relation to exposure to grain dust are chronic bronchitis, grain dust asthma, extrinsic allergic alveolitis, grain fever and silo-filler's lung. Rhinitis and conjunctivitis are also common in grain workers. While the concentration and the quality of dust influence the frequency and the type of clinical syndrome in grain workers, host factors are also important. Of the latter, smoking is the most important factor influencing the frequency of chronic bronchitis. The role of atopy and of bronchial hyperreactivity in grain dust asthma has yet to be assessed. Several well designed studies are currently being carried out in North America not only to delineate the frequency of the respiratory abnormalities, the pathogenetic mechanisms and the host factors, but also to establish a meaningful threshold limit concentration for grain dust. Images p1272-a PMID:348288

  18. The Cosmic DUNE dust astronomy mission

    NASA Astrophysics Data System (ADS)

    Grun, E.; Srama, R.; Cosmic Dune Team

    A dust astronomy mission aims at the simultaneous measurement of the origin and the chemical composition of individual dust grains in space. Interstellar dust traversing the solar system constitutes the galactic solid phase of matter from which stars and planetary systems form. Interplanetary dust, from comets and asteroids, represents remnant material from bodies at different stages of early solar system evolution. Thus, studies of interstellar and interplanetary dust with Cosmic DUNE (Cosmic Dust Near Earth) will provide a comparison between the composition of the interstellar medium and primitive planetary objects. Cosmic DUNE will prepare the way for effective collection in near-Earth space of interstellar and interplanetary dust for subsequent return to Earth and analysis in laboratories. Cosmic DUNE establishes the next logical step beyond NASA's Stardust mission, with four major advancements in cosmic dust research: (1) Analysis of the elemental and isotopic composition of individual cosmic dust grains, (2) determination of the size distribution of interstellar dust, (3) characterization of the interstellar dust flow through the planetary system, and (4) analysis of interplanetary dust of cometary and asteroidal origin. This mission goal will be reached with novel dust instrumentation. A dust telescope trajectory sensor has been developed which is capable of obtaining precision trajectories of sub-micron sized particles in space. A new high mass resolution dust analyzer of 0.1m2 impact area can cope with the low fluxes expected in interplanetary space. Cosmic DUNE will be proposed to ESA in response to its upcoming call for mission ideas.

  19. Exozodiacal Dust Workshop

    NASA Technical Reports Server (NTRS)

    Backman, D. E. (Editor); Caroff, L. J. (Editor); Sandford, S. A. (Editor); Wooden, D. H. (Editor)

    1998-01-01

    The purpose of the workshop was to understand what effect circumstellar dust clouds will have on NASA's proposed Terrestrial Planet Finder (TPF) mission's ability to search for terrestrial-sized planets orbiting stars in the solar neighborhood. The workshop participants reviewed the properties of TPF, summarized what is known about the local zodiacal cloud and about exozodiacal clouds, and determined what additional knowledge must be obtained to help design TPF for maximum effectiveness within its cost constraint. Recommendations were made for ways to obtain that additional knowledge, at minimum cost. The workshop brought together approximately 70 scientists, from four different countries. The active participants included astronomers involved in the study of the local zodiacal cloud, in the formation of stars and planetary systems, and in the technologies and techniques of ground- and space-based infrared interferometry. During the course of the meeting, 15 invited talks and 20 contributed poster papers were presented, and there were four working sessions. This is a collection of the invited talks, contributed poster papers, and summaries of the working sessions.

  20. Saharan Mineral Dust Experiment SAMUM 2006: Airborne observations of dust particle properties and vertical dust profiles

    NASA Astrophysics Data System (ADS)

    Petzold, A.; Weinzierl, B.; Esselborn, M.; Fiebig, M.; Fix, A.; Kiemle, C.; Wirth, M.; Müller, D.; Wendisch, M.; Schuetz, L.; Kandler, K.; Kahn, R.; Wagner, F.; Pereira, S.; Virkkula, A.

    2006-12-01

    The Saharan Mineral Dust Experiment (SAMUM) is an initiative of several German institutes. Its goal is the characterisation of optical, physical, chemical, and radiative properties of Saharan dust at the source region. SAMUM data may serve as ground truth data to validate satellite products and atmospheric transport models, and to support the CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) mission. The first SAMUM intensive field phase was carried out in May/June 2006 in Southern Morocco. Ground sites were Ouarzazate (30.93° N, 6.9° W), Zagora (30.15° N, 5.37°), and Evora (38.53°N, 7.90°E) in Portugal for long- range transport studies. Research aircraft were operating from Ouarzazate (Partenavia, local flights) and Casablanca (DLR Falcon) at the Moroccan west coast As part of SAMUM, airborne measurements of dust particle properties were conducted using the German research aircraft Falcon. The DLR Falcon was equipped with an extensive set of aerosol physico-chemical instruments for size, volatility, and absorption measurements, impactor sampling for chemical analyses and with a nadir-looking high spectral resolution lidar (HSRL) for measuring aerosol extinction at 532 nm, and aerosol backscatter and depolarisation at 532 nm and 1064 nm. The field sites were equipped with aerosol sampling devices and instruments for particle size distribution measurements. During the SAMUM core phase, three large-scale dust events were probed which extended from southern Morocco to Portugal. Vertical (0 10 km) and horizontal (Saharan border to southern Portugal) dust plume structures, aerosol optical depth as well as particle microphysical and optical properties were studied for all cases. The upper boundary of the dust layers was found at altitudes between 4 and 6 km above sea level. The internal structure of the dust layers varied from well mixed to stratified. The influence of the Atlas Mountains on the lifting of the dust layers was monitored

  1. Estimation of high altitude Martian dust parameters

    NASA Astrophysics Data System (ADS)

    Pabari, Jayesh; Bhalodi, Pinali

    2016-07-01

    Dust devils are known to occur near the Martian surface mostly during the mid of Southern hemisphere summer and they play vital role in deciding background dust opacity in the atmosphere. The second source of high altitude Martian dust could be due to the secondary ejecta caused by impacts on Martian Moons, Phobos and Deimos. Also, the surfaces of the Moons are charged positively due to ultraviolet rays from the Sun and negatively due to space plasma currents. Such surface charging may cause fine grains to be levitated, which can easily escape the Moons. It is expected that the escaping dust form dust rings within the orbits of the Moons and therefore also around the Mars. One more possible source of high altitude Martian dust is interplanetary in nature. Due to continuous supply of the dust from various sources and also due to a kind of feedback mechanism existing between the ring or tori and the sources, the dust rings or tori can sustain over a period of time. Recently, very high altitude dust at about 1000 km has been found by MAVEN mission and it is expected that the dust may be concentrated at about 150 to 500 km. However, it is mystery how dust has reached to such high altitudes. Estimation of dust parameters before-hand is necessary to design an instrument for the detection of high altitude Martian dust from a future orbiter. In this work, we have studied the dust supply rate responsible primarily for the formation of dust ring or tori, the life time of dust particles around the Mars, the dust number density as well as the effect of solar radiation pressure and Martian oblateness on dust dynamics. The results presented in this paper may be useful to space scientists for understanding the scenario and designing an orbiter based instrument to measure the dust surrounding the Mars for solving the mystery. The further work is underway.

  2. Climatology of the Middle East dust events

    NASA Astrophysics Data System (ADS)

    Rezazadeh, M.; Irannejad, P.; Shao, Y.

    2013-09-01

    Major sources of dust in the Middle East have been identified by analyzing the surface meteorological records from weather stations for the period 1998-2003. The geographical distribution, possible sources, and the wind patterns favoring the occurrence of four different types of dust events, i.e. dust-in-suspension, blowing dust, dust storm and severe dust storm, are examined. Four major regions of dust events are found in the study domain. These regions cover Sudan, parts of Saudi Arabia and Iraq, Pakistan, and parts of Iran and Afghanistan. The highest frequency of dust events occurs in Sudan, where the number of dust-in-suspension and severe dust storm is maximum. These events generally occur when north-easterly and north-westerly winds of less than 8 ms-1 prevail. The maximum numbers of blowing dust and dust storm are observed over Iran and Afghanistan as a result of strong north-westerlies, known as Sistan's 120-day winds. The highest values of mean dust concentration, estimated based on visibility, are found in Pakistan. The region of Saudi Arabia and Iraq are associated with relatively strong wind speeds during dust events that may carry dust particles from the sources. Because the synoptic features responsible for dust emission are different, the peak of the seasonal cycle of dust events occurs in different months of the year in different dust source regions. The major sources of dust are seen in the western parts of the domain during the winter months and shift to the east progressing towards the summer.

  3. Ice nucleation by soil dust compared to desert dust aerosols

    NASA Astrophysics Data System (ADS)

    Moehler, O.; Steinke, I.; Ullrich, R.; Höhler, K.; Schiebel, T.; Hoose, C.; Funk, R.

    2015-12-01

    A minor fraction of atmospheric aerosol particles, so-called ice-nucleating particles (INPs), initiates the formation of the ice phase in tropospheric clouds and thereby markedly influences the Earth's weather and climate systems. Whether an aerosol particle acts as an INP depends on its size, morphology and chemical compositions. The INP fraction of certain aerosol types also strongly depends on the temperature and the relative humidity. Because both desert dust and soil dust aerosols typically comprise a variety of different particles, it is difficult to assess and predict their contribution to the atmospheric INP abundance. This requires both accurate modelling of the sources and atmospheric distribution of atmospheric dust components and detailed investigations of their ice nucleation activities. The latter can be achieved in laboratory experiments and parameterized for use in weather and climate models as a function of temperature and particle surface area, a parameter called ice-nucleation active site (INAS) density. Concerning ice nucleation activity studies, the soil dust is of particular interest because it contains a significant fraction of organics and biological components, both with the potential for contributing to the atmospheric INP abundance at relatively high temperatures compared to mineral components. First laboratory ice nucleation experiments with a few soil dust samples indicated their INP fraction to be comparable or slightly enhanced to that of desert dust. We have used the AIDA (Aerosol Interaction and Dynamics in the Atmosphere) cloud simulation chamber to study the immersion freezing ability of four different arable soil dusts, sampled in Germany, China and Argentina. For temperatures higher than about -20°C, we found the INP fraction of aerosols generated from these samples by a dry dispersion technique to be significantly higher compared to various desert dust aerosols also investigated in AIDA experiments. In this contribution, we

  4. Synthesis of new tren-based tris-macrocycles. Anion cluster assembling inside the cavity generated by a bowl-shaped receptor.

    PubMed

    Bazzicalupi, Carla; Bencini, Andrea; Berni, Emanuela; Bianchi, Antonio; Ciattini, Samuele; Giorgi, Claudia; Maoggi, Sauro; Paoletti, Piero; Valtancoli, Barbara

    2002-12-13

    The synthesis of three new tris-macrocycles, containing three [12]aneN(4) (L1), [12]aneN(3)O (L2), or [14]aneN(4) (L3) moieties appended to a tren unit, is reported. The crystal structure of the [(Na(ClO(4))(6)) subset L1(2)H(13)]Na(6)Cl(2)(ClO(4))(12) compound shows the anionic cluster [Na(ClO(4))(6)](5)(-) assembled inside the cavity defined by two bowl-shaped polyammonium receptors, held by multiple charge-charge and hydrogen bond interactions.

  5. Beyond the Melting Pot and Salad Bowl Views of Cultural Diversity: Advancing Cultural Diversity Education of Nutrition Educators.

    PubMed

    Setiloane, Kelebogile Tsametse

    2016-10-01

    This article outlines how the melting pot and salad bowl views of cultural diversity have influenced the cultural training of nutrition educators and other health professionals. It explores how these views are changing in reaction to the changing demographics and health disparities seen in the US today and how the cultural training of nutrition educators has not kept up with these changing views. Suggestions for how this cultural education could be modified include placing a greater emphasis on both the cultural self-awareness of nutrition educators and the sociopolitical historical factors that influence the cultural orientation of nutrition educators and their clients.

  6. Particle Lifting Processes in Dust Devils

    NASA Astrophysics Data System (ADS)

    Neakrase, L. D. V.; Balme, M. R.; Esposito, F.; Kelling, T.; Klose, M.; Kok, J. F.; Marticorena, B.; Merrison, J.; Patel, M.; Wurm, G.

    2016-11-01

    Particle lifting in dust devils on both Earth and Mars has been studied from many different perspectives, including how dust devils could influence the dust cycles of both planets. Here we review our current understanding of particle entrainment by dust devils by examining results from field observations on Earth and Mars, laboratory experiments (at terrestrial ambient and Mars-analog conditions), and analytical modeling. By combining insights obtained from these three methodologies, we provide a detailed overview on interactions between particle lifting processes due to mechanical, thermal, electrodynamical and pressure effects, and how these processes apply to dust devils on Earth and Mars. Experiments and observations have shown dust devils to be effective lifters of dust given the proper conditions on Earth and Mars. However, dust devil studies have yet to determine the individual roles of each of the component processes acting at any given time in dust devils.

  7. MECA Workshop on Dust on Mars 3

    NASA Technical Reports Server (NTRS)

    Lee, Steven (Editor)

    1989-01-01

    Articles and abstracts of articles presented at this workshop are given. It was the goal of the workshop to stimulate cooperative research on, and discussion of, dust related processes on Mars, and to provide background information and help in planning of the Mars Observer mission. These topics are considered: How is dust ejected from the Martian surface into the atmosphere; How does the global atmospheric circulation affect the redistribution of dust on Mars; Are there sources and sinks of dust on Mars, if so, where are they and how do they vary in time; and How many components of dust are there on Mars, and what are their properties. There were four primary discussion sessions: (1) Dust in the atmosphere; (2) Dust on the surface; (3) Dust properties; and (4) Dust observations from future spacecraft missions.

  8. Four Interstellar Dust Candidates from the Stardust Interstellar Dust Collector

    NASA Technical Reports Server (NTRS)

    Westphal, A. J.; Allen, C.; Bajt, S.; Bechtel, H. A.; Borg, J.; Brenker, F.; Bridges, J.; Brownlee, D. E.; Burchell, M.; Burghammer, M.; Butterworth, A. L.; Cloetens, P.; Davis, A. M.; Floss, C.; Flynn, G. J.; Fougeray, P.; Frank, D.; Gainsforth, Z.; Grun, E.; Heck, P. R.; Jillier, J. K.; Hoppe, P.; Howard, L.; Hudson, B.; Huss, G. R.

    2011-01-01

    In January 2006, the Stardust sample return capsule returned to Earth bearing the first solid samples from a primitive solar system body, Comet 81P/Wild2, and a collector dedicated to the capture and return of contemporary interstellar dust. Both collectors were approx. 0.1 sq m in area and were composed of aerogel tiles (85% of the collecting area) and aluminum foils. The Stardust Interstellar Dust Collector (SIDC) was exposed to the interstellar dust stream for a total exposure factor of 20 sq m/day. The Stardust Interstellar Preliminary Examination (ISPE) is a consortium-based project to characterize the collection using nondestructive techniques. The goals and restrictions of the ISPE are described . A summary of analytical techniques is described.

  9. Dust Shrouds the Eastern Mediterranean

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On October 18, 2002, a large dust plume extended across countries bordering the eastern Mediterranean Sea. Information on the horizontal and vertical extent of the dust are provided by these views from the Multi-angle Imaging SpectroRadiometer (MISR). The left-hand panel portrays the scene as viewed by the instrument's vertical-viewing (nadir) camera. Here only some of the dust over eastern Syria and southeastern Turkey can be discerned. The dust is much more obvious in the center panel, which is a view from MISR's most steeply forward-looking camera. In addition, this perspective makes shadows cast by clouds onto the dust layer more apparent, providing a visual clue that the dust is at a lower altitude than these clouds.

    The right-hand panel is an elevation field derived from automated MISR stereoscopic processing, in which the heights of clouds and certain parts of the dust plume are retrieved. Because the stereoscopic approach makes use of features within the images that exhibit spatial contrast, heights for much of the dust plume (as well as the ocean surface) could not be retrieved, and these areas are shown in dark gray. Clouds within the image area are situated between about 2 and 5.5 kilometers above sea level, and the dust is located below most of the cloud, at heights of about 1.5 kilometers or less. When the stereo retrieval determines that a location is at a near-surface altitude, digital terrain elevation data are displayed instead. The highest clouds in this scene appear as the orange and red areas, and mountainous regions are displayed in light blue and green.

    The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously from pole to pole, and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. These data products were generated from a portion of the imagery acquired during Terra orbit 15072. The panels cover an area of about 380 kilometers x 827 kilometers, and utilize data from

  10. Dust density influence on complex plasma decay

    SciTech Connect

    Coueedel, L.; Mikikian, M.; Boufendi, L.

    2008-09-07

    In this paper, the influence of dust particles on the plasma losses in a complex plasma afterglow is studied. It is shown that the dust particles can drastically shorten the plasma loss time by absorption-recombination onto their surfaces. The dust particle absorption frequency increases with the dust density but the dependence is not linear for high dust density. Finally, the possible use of dust absorption frequency measurements as a diagnostics for complex plasmas is mentioned and supported by comparison to existing experimental data.

  11. Differential dust attenuation in CALIFA galaxies

    NASA Astrophysics Data System (ADS)

    Vale Asari, N.; Cid Fernandes, R.; Amorim, A. L.; Lacerda, E. A. D.; Schlickmann, M.; Wild, V.; Kennicutt, R. C.

    2016-06-01

    Dust attenuation has long been treated as a simple parameter in SED fitting. Real galaxies are, however, much more complicated: The measured dust attenuation is not a simple function of the dust optical depth, but depends strongly on galaxy inclination and the relative distribution of stars and dust. We study the nebular and stellar dust attenuation in CALIFA galaxies, and propose some empirical recipes to make the dust treatment more realistic in spectral synthesis codes. By adding optical recombination emission lines, we find better constraints for differential attenuation. Those recipes can be applied to unresolved galaxy spectra, and lead to better recovered star formation rates.

  12. Particle atlas of World Trade Center dust

    USGS Publications Warehouse

    Lowers, Heather; Meeker, Gregory P.

    2005-01-01

    The United States Environmental Protection Agency (EPA) has begun a reassessment of the presence of World Trade Center (WTC) dust in residences, public buildings, and office spaces in New York City, New York. Background dust samples collected from residences, public buildings, and office spaces will be analyzed by multiple laboratories for the presence of WTC dust. Other laboratories are currently studying WTC dust for other purposes, such as health effects studies. To assist in inter-laboratory consistency for identification of WTC dust components, this particle atlas of phases in WTC dust has been compiled.

  13. The Origin and Evolution of Interstellar Dust

    NASA Technical Reports Server (NTRS)

    Dwek, Eli; Houches, Les

    2006-01-01

    In this lecture I will discuss the many different manifestation of interstellar dust, and current dust models that satisfy interstellar extinction, diffuse infrared emission, and interstellar abundances constraints. Dust is made predominantly in AGB stars and Type I1 supernovae, and I will present observational evidence for the presence of dust in these sources. I will then present chemical evolution models that follow the abundance of dust which is determined by the combined processes of formation, destruction by interstellar shock waves, and accretion in molecular clouds. The model will be applied to the evolution of PAHs and the evolution of dust in the high-redshift galaxy (z=6.42) JD11.

  14. The global atmospheric loading of dust aerosols

    NASA Astrophysics Data System (ADS)

    Kok, J. F.; Ridley, D. A.; Haustein, K.; Miller, R. L.; Zhao, C.

    2015-12-01

    Mineral dust is one of the most ubiquitous aerosols in the atmosphere, with important effects on human health and the climate system. But despite its importance, the global atmospheric loading of dust has remained uncertain, with model results spanning about a factor of five. Here we constrain the particle size-resolved atmospheric dust loading and global emission rate, using a novel theoretical framework that uses experimental constraints on the optical properties and size distribution of dust to eliminate climate model errors due to assumed dust properties. We find that most climate models underestimate the global atmospheric loading and emission rate of dust aerosols.

  15. Solar Wind Speed Charged Dust

    NASA Astrophysics Data System (ADS)

    Russell, C. T.; Weimer, D.; Jian, L. K.; Luhmann, J. G.; Omidi, N.

    2009-04-01

    The correlation of the occurrence of magnetic disturbances, known as interplanetary field enhancements (IFEs), with the asteroid 2201 Oljato can only be explained as the interaction with charged dust in the asteroid's orbit, because the events occurred both before and after alignment with the asteroid. These single spacecraft observations did not determine how fast the dust was accelerated, or if they were affected at all by the solar wind. Shortly after STEREO A and B were launched, an IFE crossed the two spacecraft as well as ACE and Wind. This four-spacecraft configuration allowed us to determine that the disturbance was moving radially outward at 700 km/s, the solar wind speed. The conventional wisdom is that only the smallest dust particles can be affected by the solar wind, but examination of periods on STEREO when the spacecraft is being sprayed with multiple beta-meteoroid strikes shows no obvious correlation. Further, the IFEs are much less frequent than the "beta-meteoroid" impacts. Hence, it is possible that IFEs are associated with much larger dust particles, perhaps 1 micron-sized dust. If true, then those particles may be very dangerous albeit rare, possessing about 104 ergs.

  16. Dust reradiation from M43

    NASA Astrophysics Data System (ADS)

    Smith, J.; Harper, D. A.; Loewenstein, R. F.

    1987-03-01

    Far-IR and molecular observations of M43 and its neutral environment are presented. Dust particles mixed with plasma, atoms, and molecules of the observed region are found to produce the measured far-IR emissions. M43 and its neutral environment have a simple morphology, consisting primarily of a relatively dust-free H II region and its centrally located exciting star lying next to the dense concentration of neutral material known as the Orion Ridge. The exciting star, NU Ori, is an important source of excitation of the dust associated with M43. Dust mixed with gas lying along or outside the near circular boundary of M43 is important for the energy balance of the M43 region. The amount of far-IR reradiation observed from the central 1 arcmin of M43 is equivalent to only about one percent of the NU Ori luminosity. a fraction implying a small value for the normalized absorption optical depth. This may partly explain why extinction by dust appears to have little effect on the excitation of the M43 plasma.

  17. Dust near luminous ultraviolet stars

    NASA Technical Reports Server (NTRS)

    Henry, Richard C.

    1993-01-01

    This report describes research activities related to the Infrared Astronomical Satellite (IRAS) sky survey. About 745 luminous stars were examined for the presence of interstellar dust heated by a nearby star. The 'cirrus' discovered by IRAS is thermal radiation from interstellar dust at moderate and high galactic latitudes. The IRAS locates the dust which must (at some level) scatter ultraviolet starlight, although it was expected that thermal emission would be found around virtually every star, most stars shown no detectable emission. And the emission found is not uniform. It is not that the star is embedded in 'an interstellar medium', but rather what is found are discrete clouds that are heated by starlight. An exception is the dearth of clouds near the very hottest stars, implying that the very hottest stars play an active role with respect to destroying or substantially modifying the dust clouds over time. The other possibility is simply that the hottest stars are located in regions lacking in dust, which is counter-intuitive. A bibliography of related journal articles is attached.

  18. Dust near luminous ultraviolet stars

    NASA Technical Reports Server (NTRS)

    Henry, Richard C.

    1992-01-01

    More than 700 luminous stars in the infrared astronomical satellite (IRAS) Skyflux plates were examined for the presence of dust heated by a nearby star. This dust may be distinguished from the ubiquitous cool cirrus by its higher temperature and thus enhanced 60 micron emission. More than 120 dust clouds were found around only 106 of the stars with a volume filling factor of 0.006 and an intercloud separation of 46 pc. A region of dust smoothly distributed through the volume of space heated by the star could not be found and hence an upper limit of 0.05 cm(exp -3) is placed on the equivalent gas density in the intercloud regions. The clouds have an average density of 0.22 cm(exp -3) and a radius of 1.9 pc, albeit with wide variations in their properties. Two different scale heights of 140 and 540 pc were found. This was interpreted as evidence for different distributions of dust in and out of the galactic disk.

  19. Glass Frit Clumping And Dusting

    SciTech Connect

    Steimke, J. L.

    2013-09-26

    DWPF mixes a slurry of glass frit (Frit 418) and dilute (1.5 wt%) formic acid solution with high level waste in the Slurry Mix Evaporator (SME). There would be advantages to introducing the frit in a non-slurry form to minimize water addition to the SME, however, adding completely dry frit has the potential to generate dust which could clog filters or condensers. Prior testing with another type of frit, Frit 320, and using a minimal amount of water reduced dust generation, however, the formation of hard clumps was observed. To examine options and behavior, a TTQAP [McCabe and Stone, 2013] was written to initiate tests that would address these concerns. Tests were conducted with four types of glass frit; Frit 320, DWPF Frit 418, Bekeson Frit 418 and Multi-Aspirator Frit 418. The last two frits are chemically identical to DWPF Frit 418 but smaller particles were removed by the respective vendors. Test results on Frit Clumping and Dusting are provided in this report. This report addresses the following seven questions. Short answers are provided below with more detailed answers to follow. 1. Will the addition of a small amount of water, 1.5 wt%, to dry DWPF Frit 418 greatly reduce the dust generation during handling at DWPF? a. Yes, a small scale test showed that adding a little water to the frit greatly reduced dust generation during handling. 2. Will the addition of small amounts of water to the frit cause clumping that will impair frit handling at DWPF? a. No, not with Frit 418. Although clumps were observed to form when 1.5 wt% water was mixed with DWPF Frit 418, then compressed and air-dried overnight, the clumps were easily crushed and did not form the hardened material noted when Frit 320 was tested. 3. What is the measured size distribution of dust generated when dry frit is handled? (This affects the feasibility and choice of processing equipment for removing the dust generating fraction of the frit before it is added to the SME.) a. The size distribution for

  20. Planetary Magnetosphere Probed by Charged Dust Particles

    NASA Astrophysics Data System (ADS)

    Sternovsky, Z.; Horanyi, M.; Gruen, E.; Srama, R.; Auer, S.; Kempf, S.; Krueger, H.

    2010-12-01

    In-situ and remote sensing observations combined with theoretical and numerical modeling greatly advanced our understanding planetary magnetospheres. Dust is an integral component of the Saturnian and Jovian magnetospheres where it can act as a source/sink of plasma particles (dust particles are an effective source for plasma species like O2, OH, etc. through sputtering of ice particles, for example); its distribution is shaped by electrodynamic forces coupled radiation pressure, plasma, and neutral drag, for example. The complex interaction can lead to unusual dust dynamics, including the transport, capture, and ejection of dust grains. The study of the temporal and spatial evolution of fine dust within or outside the magnetosphere thus provides a unique way to combine data from a large number of observations: plasma, plasma wave, dust, and magnetic field measurements. The dust detectors on board the Galileo and Cassini spacecrafts lead to major discoveries, including the jovian dust stream originating from Io or the in-situ sampling and analysis of the plumes of Enceladus. Recent advancement in dust detector technology enables accurate measurement of the dust trajectory and elemental composition that can greatly enhance the understanding of dust magnetorspheric interaction and indentify the source of the dust with high precision. The capabilities of a modern dust detector thus can provide support for the upcoming Europa Jupiter System Mission.

  1. Dust devils as observed by Mars Pathfinder

    NASA Astrophysics Data System (ADS)

    Ferri, Francesca; Smith, Peter H.; Lemmon, Mark; Rennó, Nilton O.

    2003-12-01

    Dust devils are localized meteorological phenomena frequently observed in terrestrial dry lands and desert landscapes as well as on Mars. They are low-pressure, warm core vortices that form at the bottom of convective plumes and loft dust from the surface. They move with the speed of the ambient wind and are tilted by wind shears. The Mars Pathfinder detected dust devils as dust plumes in the Imager for Mars Pathfinder images and as low-pressure convective vortices in the meteorological Mars Pathfinder Atmospheric Structure Investigation/Meteorology (ASI/MET) experiment data. The Pathfinder data have been analyzed in terms of dust devil size, spatial distribution, and frequency of occurrence. The results show that the Pathfinder imaging and MET observations are consistent with each other and with the observations made by the Viking 1 Orbiter and Mars Global Surveyor. The dust devil's ability to loft dust into the atmosphere has been investigated and a thermodynamic theory for dust devils has been used to calculate their physical parameters relevant to dust transport. The dust devils observed in an active day provide a pumping rate larger than the dust-settling rate derived from the optical obscuration of the Pathfinder rover solar panels. Therefore dust devils are a major factor in transporting dust from the surface to the atmosphere at the Pathfinder site.

  2. Springtime North Polar Dust Storms

    NASA Technical Reports Server (NTRS)

    2002-01-01

    MGS MOC Release No. MOC2-321, 12 December 2002

    As on the Earth, many severe storms brew in the martian polar regions. Here, temperature contrasts between the cold carbon dioxide ('dry ice') seasonal frost cap and the warm ground adjacent to it--combined with a flow of cool polar air evaporating off the cap--sweeps up dust and funnels it into swirling dust storms along the cap edge. The dust storms shown here were observed during the recent northern spring by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) in May 2002. The picture is a mosaic of daily global images from the MOC wide angle cameras. The north polar cap is the bright, frosty surface at the top.

  3. Desert Dust and Monsoon Rain

    NASA Technical Reports Server (NTRS)

    Lau, William K. M.; Kim, Kyu-Myong

    2014-01-01

    For centuries, inhabitants of the Indian subcontinent have know that heavy dust events brought on by strong winds occur frequently in the pre-monsoon season, before the onset of heavy rain. Yet scientists have never seriously considered the possibility that natural dust can affect monsoon rainfall. Up to now, most studies of the impacts of aerosols on Indian monsoon rainfall have focused on anthropogenic aerosols in the context of climate change. However, a few recent studies have show that aerosols from antropogenic and natural sources over the Indian subcontinent may affect the transition from break to active monsoon phases on short timescales of days to weeks. Writing in Nature Geoscience, Vinoj and colleagues describe how they have shown that desert dust aerosols over the Arabian Sea and West Asia can strenghten the summer monsoon over the Indial subcontinent in a matter of days.

  4. Dust Devil Populations and Statistics

    NASA Astrophysics Data System (ADS)

    Lorenz, Ralph D.; Jackson, Brian K.

    2016-11-01

    The highly-skewed diameter and pressure drop distributions of dust devils on Earth and Mars are noted, and challenges of presenting and comparing different types of observations are discussed. The widely-held view that Martian dust devils are larger than Earth's is critically assessed: the question is confounded somewhat by different observation techniques, but some indication of a {˜} 3x larger population on Mars is determined. The largest and most intense (in a relative pressure sense) devils recorded are on Mars, although the largest reported number density is on Earth. The difficulties of concepts used in the literature of `average' diameter, pressure cross section, and area fraction are noted in the context of estimating population-integral effects such as dust lifting.

  5. Pulmonary retention of coal dusts

    SciTech Connect

    Morrow, P.E.; Gibb, F.R.; Beiter, H.; Amato, F.; Yuile, C.; Kilpper, R.W.

    1980-01-01

    The principal objectives of this study were: to determine, quantitatively, coal dust retention times in the dog lung; to test the appropriateness of a pulmonary retention model which incorporates first order rate coefficients obtained from in vitro and in vivo experiments on neutron-activated coal; to acquire a temporal description of the pulmonary disposition of the retained coal dust, and to compare the behavior of two different Pennsylvania coals in the foregoing regards. The principal findings include: retention half-times for both coals of approximately 2 years following single, hour-long exposures; a vivid association of the retained coal dust with the pulmonic lymphatics; and a general validation of the retention model.

  6. Recovery of ultra fine bituminous coal from screen-bowl centrifuge effluent: A possible feedstock for coal-water slurry fuels?

    SciTech Connect

    Morrison, J.L.; Miller, B.G.; Battista, J.J.

    1998-07-01

    Coal fines have historically been viewed as a size fraction which are difficult to handle and expensive to clean and dewater. Consequently, many coal suppliers in the past have chosen to discard their coal fines in slurry impoundments rather than beneficiating them. These disposal costs are then passed onto the end user. Today, with the advent of advanced fine coal cleaning technologies, more stringent environmental policies, and increased pressure by coal-fired utilities to reduce their operating costs, the industry is taking a more progressive look at fine coal recovery options. This paper discusses a fine coal recovery project which is currently being conducted at the Homer City Coal Cleaning Plant (HCCCP) located in western Pennsylvania. The HCCCP utilizes heavy media cyclone, spiral, and conventional froth flotation circuits to clean approximately 4.3 million tons of low to medium volatile bituminous coal annually for the adjacent 1,884 net MW{sub e} Homer City Generating Station. The project focuses on recovering minus 325 mesh coal fines from the effluent of screen-bowl centrifuges. The HCCCP screen-bowl effluent contains approximately 3 to 5 wt.% of suspended coal fines. Approximately 100,000 tons of coal fines are estimated to be lost per year. These coal fines represent a Btu loss, require flocculant prior to the static thickeners and belt presses, contribute excess moisture to the plant refuse which leads to handling and compaction problems during refuse disposal, and contribute to the premature filling of the refuse site.

  7. Recovery of ultra fine bituminous coal from screen-bowl centrifuge effluent: A possible feedstock for coal-water slurry fuels?

    SciTech Connect

    Morrison, J.L.; Miller, B.G.; Battista, J.J.

    1998-04-01

    Coal fines have historically been viewed as a size fraction which are difficult to handle and expensive to clean and dewater. Consequently, many coal suppliers in the past have chosen to discard their coal fines in slurry impoundments rather than beneficiating them. These disposal costs are then passed onto the end user. Today, with the advent of advanced fine coal cleaning technologies, more stringent environmental policies, and increased pressure by coal-fired utilities to reduce their operating costs, the industry is taking a more progressive look at fine coal recovery options. This paper discusses a fine coal recovery project which is currently being conducted at the Homer City Coal Cleaning Plant (HCCCP) located in western Pennsylvania. The HCCCP utilizes heavy media cyclone, spiral, and conventional froth flotation circuits to clean approximately 4.3 million tons of low to medium volatile bituminous coal annually for the adjacent 1,884 net MW{sub e} Homer City Generating Station. The project focuses on recovering minus 325 mesh coal fines from the effluent of screen-bowl centrifuges. The HCCCP screen-bowl effluent contains approximately 3 to 5 wt.% of suspended coal fines. Approximately 100,000 tons of coal fines are estimated to be lost per year. These coal fines represent a Btu loss, require flocculent prior to the static thickeners and belt presses, contribute excess moisture to the plant refuse which leads to handling and compaction problems during refuse disposal, and contribute to the premature filling of the refuse site.

  8. Bowling for Elementary Students

    ERIC Educational Resources Information Center

    Curtis, Joyce M.

    2005-01-01

    Physical education programs at the elementary school level play an important role in developing students' interest and skill in lifelong physical activities. With increasing inactivity, overweight, and obesity among children, school physical education programs are challenged with presenting activities that can be enjoyed in childhood and…

  9. Lickin' the Bowl.

    ERIC Educational Resources Information Center

    Wilson, Elaine; Good, Rosemary

    Teaching materials and home-based activities for teachers and parents of preschool children provide learning activities that explore and use a variety of nutritious foods along with teaching language, mathematics, science, reading, and motor skills. A series of nine newsletters to be sent to parents contains an introduction to the program and…

  10. Slab Leaf Bowls

    ERIC Educational Resources Information Center

    Suitor, Cheryl

    2012-01-01

    In science class, fourth graders investigate the structure of plants and leaves from trees and how the process of photosynthesis turns sunlight into sugar proteins. In this article, the author fuses art and science for a creative and successful clay slab project in her elementary art classroom. (Contains 1 online resource.)

  11. Remote sensing of dust in the Solar system and beyond using wavelength dependence of polarization

    NASA Astrophysics Data System (ADS)

    Kolokolova, L.

    2011-12-01

    For a long time, the main polarimetric tool to study dust in the Solar system has been the dependence of polarization on phase (scattering) angle. Surprisingly, a variety of cosmic dusts (interplanetary and cometary dust, dust on the surfaces of asteroids and in debris disks) possesses a very similar phase dependence of polarization with a negative bowl-shaped part at small phase angles and a positive bell-shaped region with maximum polarization around 95-105 deg. Numerous laboratory and theoretical simulations showed that a polarimetric phase curve of this shape is typical for fluffy materials, e.g., porous, aggregated particles. By contrast, the wavelength dependence of polarization is different for different types of dust. In the visual, polarization decreases with wavelength (negative gradient) for asteroids and interplanetary dust, but usually increases with wavelength (positive gradient) for cometary dust. In debris disks both signs of the spectral gradient of polarization have been found. Moreover, it was found that a cometary positive spectral gradient can change to a negative one as observations move to longer (near-infrared) wavelengths (Kelley et al. AJ, 127, 2398, 2004) and some comets(Kiselev et al. JQSRT, 109, 1384, 2008) have negative gradient even in the visible. The diversity of the spectral dependence of polarization therefore gives us hope that it can be used for characterization of the aggregates that represent different types of cosmic dust. To accomplish this, the physics behind the spectral dependence of polarization need to be revealed. Our recent study shows that the spectral dependence of polarization depends on the strength of electromagnetic interaction between the monomers in aggregates. The strength of the interaction mainly depends on how many monomers the electromagnetic wave covers on the light path equal to one wavelength. Since the electromagnetic interaction depolarizes the light, the more particles a single wavelength covers the

  12. Laser dusting of delicate objects

    NASA Astrophysics Data System (ADS)

    Asmus, John F.; Abraham, Meg

    2005-06-01

    Since the inception of the laser-divestment process, emphasis has focused on the treatment of reasonably durable materials. Marble, limestone, sandstone, and bronze are foremost among these. In most situations the objective of laser divestment is the removal of superficial corrosion or chemical-decomposition products. To a lesser extent laser ablation is also used to treat diverse surface problems for a spectrum of other historic and artistic substrates such as paper, vellum, ivory, paint, and plaster. Although materials of this sort are not particularly strong, their optical, thermodynamical, and mechanical properties are sufficiently propitious to enable successful laser treatment (with the exercise of precise control). There is another, quite different, cleaning problem encountered in the maintenance of museum collections. This is often referred to as "dusting" (in contrast to "divestment" or "conservation"). Vacuuming, wiping, blowing, and feather dusting are used most often to improve the cosmetic appearance of museum objects after dust and aerosols have accumulated on exposed surfaces. However, many collections include extremely friable pieces composed of feathers, fir, hair, plant fibers, or mummified skin. Conventional dusting may be impossible in such instances. From experimental observations and theoretical analyses we speculate that at very low fluxes laser-induced acoustic and electrostatic forces are responsible for the ejection of debris. Laboratory experiments demonstrated that laser dusting was effective on feathers and textiles, The practical viability of laser dusting was demonstrated by laser-cleaning two very large sand sculptures by San Diego artist C.R. Faust. In contrast, all conventional cleaning techniques damaged the surface by dislodging sand grains.

  13. Laboratory simulation of dust spectra

    NASA Technical Reports Server (NTRS)

    Allamandola, L. J.; Sandford, S. A.

    1988-01-01

    Laboratory studies of the IR spectra of interstellar dust are reviewed. Studies of the absorption spectra of dense molecular clouds are discussed, including methods to produce interstellar ice analogues, simulations of astronomical spectra, and IR absorption features caused by ices. Comparisons are made between observational and experimental results of interstellar dust studies. Also, the interstellar emission features associated with dusty regions exposed to UV radiation are examined, including bands related to PAHs and PAH-related materials. It is shown that interstellar spectra are more consistant with emission from free PAHs than with emission from particles.

  14. Dust around Type Ia supernovae

    SciTech Connect

    Wang, Lifan

    2005-10-20

    An explanation is given of the low value of R lambda triple bond A lambda/E(B - V), the ratio of absolute to selective extinction deduced from Type Ia supernova observations. The idea involves scattering by dust clouds located in the circumstellar environment, or at the highest velocity shells of the supernova ejecta. The scattered light tends to reduce the effective R lambda in the optical, but has an opposite effect in the ultraviolet. The presence of circumstellar dust can be tested by ultraviolet to near infrared observations and by multi-epoch spectropolarimetry of SNe Ia.

  15. Improving dust and methane control

    SciTech Connect

    Cecala, A.; Organiscak, J.; Jankowski, R.

    1987-10-01

    The Bureau of Mines has evaluated a number of techniques for controlling dust and methane during the headgate cutout of retreating longwall sections that use antitropal ventilation (headgate to tailgate). Some of these techniques are effective for both methane and dust control, while others are effective for only one or the other. The techniques include the gob curtain, the walkway curtain, stageloader-crusher control and the wing curtain. Each improves the health and safety of workers and is economically feasible in hardware cost, setup cost and maintenance.

  16. Improving dust and methane control

    SciTech Connect

    Cecala, A.; Organiseak, J.; Jankowski, R.

    1987-01-01

    This paper presents a number of techniques for controlling dust and methane during the headgate cutout of retreating longwall sections that use antitropal ventilation (headgate to tailgate). Some of these techniques are effective for both methane and dust control, while others are effective for only one or the other. The techniques include the gob curtain, the walkway curtain, stage-loader-crusher control, and the wing curtain. Each improves the health and safety of workers and is economically feasible in hardware cost, setup cost, and maintenance.

  17. [Effect of lunar dust on humans: -lunar dust: regolith-].

    PubMed

    Morimoto, Yasuo; Miki, Takeo; Higashi, Toshiaki; Horie, Seichi; Tanaka, Kazunari; Mukai, Chiaki

    2010-09-01

    We reviewed the effect of lunar dust (regolith) on humans by the combination of the hazard/exposure of regolith and microgravity of the moon. With regard to the physicochemical properties of lunar dust, the hazard-related factors are its components, fibrous materials and nanoparticles. Animal exposure studies have been performed using a simulant of lunar dust, and it was speculated that the harmful effects of the simulant lies between those of crystalline silica and titanium dioxide. Fibrous materials may not have a low solubility judging from their components. The nanoparticles in lunar dust may have harmful potentials from the view of the components. As for exposure to regolith, there is a possibility that particles larger than ones in earth (1 gravity) are respirable. In microgravity, 1) the deposition of particles of less than 1 µm in diameter in the human lung did not decrease, 2) the functions of macrophages including phagocytosis were suppressed, 3) pulmonary inflammation was changed. These data on hazard/exposure and microgravity suggest that fine and ultrafine particles in regolith may have potential hazards and risks for humans.

  18. Infrared Observations of Cometary Dust and Nuclei

    NASA Technical Reports Server (NTRS)

    Lisse, Carey

    2004-01-01

    This bibliography lists citations for publications published under the grant. Subjects of the publications include cometary dust, instellar and interplanetary dust, comet nuclei and comae, Comet Hale-Bopp, infrared observations of comets, mass loss, and comet break-up.

  19. The Dust Environment of the Moon

    NASA Astrophysics Data System (ADS)

    Horanyi, M.; Szalay, J.; Gruen, E.; Glenar, D.; Wang, X.; Zakharov, A.

    2016-05-01

    We will briefly review the history of the observations of the lunar dust environment, but mainly focus on the results of the LADEE mission, and the recent laboratory results on the charging and mobilization of dust particles on regolith surfaces.

  20. Dust particles interaction with plasma jet

    SciTech Connect

    Ticos, C. M.; Jepu, I.; Lungu, C. P.; Chiru, P.; Zaroschi, V.

    2009-11-10

    The flow of plasma and particularly the flow of ions play an important role in dusty plasmas. Here we present some instances in laboratory experiments where the ion flow is essential in establishing dust dynamics in strongly or weakly coupled dust particles. The formation of ion wake potential and its effect on the dynamics of dust crystals, or the ion drag force exerted on micron size dust grains are some of the phenomena observed in the presented experiments.