WorldWideScience

Sample records for high-alpine cushion plant

  1. Cushion plants as islands.

    Science.gov (United States)

    Tepedino, V J; Stanton, N L

    1976-09-01

    The acarine fauna of two abundant species of cushion plant on the high, short-grass prairie of S.E. Wyoming were used to test The MacArthur-Wilson Theory of Island Biogeography. Multiple regression analysis using area, distance and percent moisture as independent variables and number of mite species and number of mite individuals were run for the two sampling dates. Results showed area alone to be consistently and highly correlated (r=0.84-0.94) with both species and individuals for one cushion species. The slopes of the species-area and individuals-area curves are among the highest recorded and were significantly higher on the second sampling date. Selective seasonal changes in the fauna were shown by increases both in numbers of species and individuals, mainly on larger cushions, for the later sampling period. It is hypothesized that seasonal changes are due to an increase in the number of predator species in response to an increase in the number of prey items. The slopes of the species-area curves are compared with those in the literature and it is argued that slope values are more dependent upon the taxonomic group being studied than on whether the island is insular or oceanic. Finally, we suggest that The MacArthur-Wilson Theory is not applicable to islands which 1) exhibit continuous growth, 2) lack a discrete species source, and 3) are relatively transitory.

  2. Changes in chloroplast ultrastructure in some high-alpine plants: adaptation to metabolic demands and climate?

    Science.gov (United States)

    Lütz, C; Engel, L

    2007-01-01

    The cytology of leaf cells from five different high-alpine plants was studied and compared with structures in chloroplasts from the typical high-alpine plant Ranunculus glacialis previously described as having frequent envelope plus stroma protrusions. The plants under investigation ranged from subalpine/alpine Geum montanum through alpine Geum reptans, Poa alpina var. vivipara, and Oxyria digyna to nival Cerastium uniflorum and R. glacialis. The general leaf structure (by light microscopy) and leaf mesophyll cell ultrastructure (by transmission electron microscopy [TEM]) did not show any specialized structures unique to these mountain species. However, chloroplast protrusion formation could be found in G. reptans and, to a greater extent, in O. digyna. The other species exhibited only a low percentage of such chloroplast structural changes. Occurrence of protrusions in samples of G. montanum and O. digyna growing in a mild climate at about 50 m above sea level was drastically reduced. Serial TEM sections of O. digyna cells showed that the protrusions can appear as rather broad and long appendices of plastids, often forming pocketlike structures where mitochondria and microbodies are in close vicinity to the plastid and to each other. It is suggested that some high-alpine plants may form such protrusions to facilitate fast exchange of molecules between cytoplasm and plastid as an adaptation to the short, often unfavorable vegetation period in the Alps, while other species may have developed different types of adaptation that are not expressed in ultrastructural changes of the plastids.

  3. Cooccurrence patterns of plants and soil bacteria in the high-alpine subnival zone track environmental harshness

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    Andrew J. King

    2012-10-01

    Full Text Available Plants and soil microorganisms interact to play a central role in ecosystem functioning. To determine the potential importance of biotic interactions in shaping the distributions of these organisms in a high-alpine subnival landscape, we examine cooccurrence patterns between plant species and bulk-soil bacteria abundances. In this context, a cooccurrence relationship reflects a combination of several assembly processes: that both parties can disperse to the site, that they can survive the abiotic environmental conditions, and that interactions between the biota either facilitate survival or allow for coexistence. Across the entire landscape, 31% of the bacterial sequences in this dataset were significantly correlated to the abundance distribution of one or more plant species. These sequences fell into 14 clades, 6 of which are related to bacteria that are known to form symbioses with plants in other systems. Abundant plant species were more likely to have significant as well as stronger correlations with bacteria and these patterns were more prevalent in lower altitude sites. Conversely, correlations between plant species abundances and bacterial relative abundances were less frequent in sites near the snowline. Thus, plant-bacteria associations became more common as environmental conditions became less harsh and plants became more abundant. This pattern in cooccurrence strength and frequency across the subnival landscape suggests that plant-bacteria interactions are important for the success of life, both below- and above-ground, in an extreme environment.

  4. Moss cushions facilitate water and nutrient supply for plant species on bare limestone pavements

    DEFF Research Database (Denmark)

    Jensen, Kaj Sand; Hammer, Kathrine

    2012-01-01

    Dense moss cushions of different size are distributed across the bare limestone pavements on Øland, SE Sweden. Increasing cushion size is predicted to physically protect and improve performance and colonization by vascular plants. Therefore, we tested water balance, phosphorus supply, and species...... richness, and evaluated duration of plant activity during desiccation as a function of ground area, for a large collection of moss cushions. We found that lower evaporation and higher water storage contributed equally to extending the desiccation period with increasing cushion size. Evaporation rates...... under stagnant conditions. One moss species was added to the species pool for every nine-fold increase in cushion area. Vascular plants were absent from the smallest cushions, whereas one or two species, on average, appeared in 375- and 8,500-cm(2) cushions with water available for 6 and 10 days during...

  5. A systematic review of the recent ecological literature on cushion plants: champions of plant facilitation

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    A. M. Reid

    2010-09-01

    Full Text Available Cushion-forming plant species are found in alpine and polar environments around the world. They modify the microclimate, thereby facilitating other plant species. Similar to the effectiveness of shrubs as a means to study facilitation in arid and semi-arid environments, we explore the potential for cushion plant species to expand the generality of research on this contemporary ecological interaction. A systematic review was conducted to determine the number of publications and citation frequency on relevant ecological topics whilst using shrub literature as a baseline to assess relative importance of cushions as a focal point for future ecological research. Although there are forty times more shrub articles, mean citations per paper is comparable between cushion and shrub literature. Furthermore, the scope of ecological research topics studied using cushions is broad including facilitation, competition, environmental gradients, life history, genetics, reproduction, community, ecosystem and evolution. The preliminary ecological evidence to date also strongly suggests that cushion plants can be keystone species in their ecosystems. Hence, ecological research on net interactions including facilitation and patterns of diversity can be successfully examined using cushion plants, and this is particularly timely given expectations associated with a changing climate in these regions.

  6. Ecology and life history affect different aspects of the population structure of 27 high-alpine plants.

    Science.gov (United States)

    Meirmans, Patrick G; Goudet, Jerome; Gaggiotti, Oscar E

    2011-08-01

    A plant species' genetic population structure is the result of a complex combination of its life history, ecological preferences, position in the ecosystem and historical factors. As a result, many different statistical methods exist that measure different aspects of species' genetic structure. However, little is known about how these methods are interrelated and how they are related to a species' ecology and life history. In this study, we used the IntraBioDiv amplified fragment length polymorphisms data set from 27 high-alpine species to calculate eight genetic summary statistics that we jointly correlate to a set of six ecological and life-history traits. We found that there is a large amount of redundancy among the calculated summary statistics and that there is a significant association with the matrix of species traits. In a multivariate analysis, two main aspects of population structure were visible among the 27 species. The first aspect is related to the species' dispersal capacities and the second is most likely related to the species' postglacial recolonization of the Alps. Furthermore, we found that some summary statistics, most importantly Mantel's r and Jost's D, show different behaviour than expected based on theory. We therefore advise caution in drawing too strong conclusions from these statistics.

  7. Zero methane emission bogs: extreme rhizosphere oxygenation by cushion plants in Patagonia.

    Science.gov (United States)

    Fritz, Christian; Pancotto, Veronica A; Elzenga, Josephus T M; Visser, Eric J W; Grootjans, Ab P; Pol, Arjan; Iturraspe, Rodolfo; Roelofs, Jan G M; Smolders, Alfons J P

    2011-04-01

    • Vascular wetland plants may substantially increase methane emissions by producing root exudates and easily degradable litter, and by providing a low-resistance diffusion pathway via their aerenchyma. However, model studies have indicated that vascular plants can reduce methane emission when soil oxygen demand is exceeded by oxygen released from roots. Here, we tested whether these conditions occur in bogs dominated by cushion plants. • Root-methane interactions were studied by comparing methane emissions, stock and oxygen availability in depth profiles below lawns of either cushion plants or Sphagnum mosses in Patagonia. • Cushion plants, Astelia pumila and Donatia fascicularis, formed extensive root systems up to 120 cm in depth. The cold soil (microbial activity and oxygen consumption. In cushion plant lawns, high soil oxygen coincided with high root densities, but methane emissions were absent. In Sphagnum lawns, methane emissions were substantial. High methane concentrations were only found in soils without cushion plant roots. • This first methane study in Patagonian bog vegetation reveals lower emissions than expected. We conclude that cushion plants are capable of reducing methane emission on an ecosystem scale by thorough soil and methane oxidation. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  8. The best for the guest: high Andean nurse cushions of Azorella madreporica enhance arbuscular mycorrhizal status in associated plant species.

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    Casanova-Katny, M Angélica; Torres-Mellado, Gustavo Adolfo; Palfner, Goetz; Cavieres, Lohengrin A

    2011-10-01

    Positive interactions between cushion plant and associated plants species in the high Andes of central Chile should also include the effects of fungal root symbionts. We hypothesized that higher colonization by arbuscular mycorrhizal (AM) fungi exists in cushion-associated (nursling) plants compared with conspecific individuals growing on bare ground. We assessed the AM status of Andean plants at two sites at different altitudes (3,200 and 3,600 ma.s.l.) in 23 species, particularly in cushions of Azorella madreporica and five associated plants; additionally, AM fungal spores were retrieved from soil outside and beneath cushions. 18 of the 23 examined plant species presented diagnostic structures of arbuscular mycorrhiza; most of them were also colonized by dark-septate endophytes. Mycorrhization of A. madreporica cushions showed differences between both sites (68% and 32%, respectively). In the native species Hordeum comosum, Nastanthus agglomeratus, and Phacelia secunda associated to A. madreporica, mycorrhization was six times higher than in the same species growing dispersed on bare ground at 3,600 ma.s.l., but mycorrhiza development was less cushion dependent in the alien plants Cerastium arvense and Taraxacum officinale at both sites. The ratio of AM fungal spores beneath versus outside cushions was also 6:1. The common and abundant presence of AM in cushion communities at high altitudes emphasizes the importance of the fungal root symbionts in such situations where plant species benefit from the microclimatic conditions generated by the cushion and also from well-developed mycorrhizal networks.

  9. The alpine cushion plant Silene acaulis as foundation species: a bug's-eye view to facilitation and microclimate.

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    Olivia Molenda

    Full Text Available Alpine ecosystems are important globally with high levels of endemic and rare species. Given that they will be highly impacted by climate change, understanding biotic factors that maintain diversity is critical. Silene acaulis is a common alpine nurse plant shown to positively influence the diversity and abundance of organisms--predominantly other plant species. The hypothesis that cushion or nurse plants in general are important to multiple trophic levels has been proposed but rarely tested. Alpine arthropod diversity is also largely understudied worldwide, and the plant-arthropod interactions reported are mostly negative, that is,. herbivory. Plant and arthropod diversity and abundance were sampled on S. acaulis and at paired adjacent microsites with other non-cushion forming vegetation present on Whistler Mountain, B.C., Canada to examine the relative trophic effects of cushion plants. Plant species richness and abundance but not Simpson's diversity index was higher on cushion microsites relative to other vegetation. Arthropod richness, abundance, and diversity were all higher on cushion microsites relative to other vegetated sites. On a microclimatic scale, S. acaulis ameliorated stressful conditions for plants and invertebrates living inside it, but the highest levels of arthropod diversity were observed on cushions with tall plant growth. Hence, alpine cushion plants can be foundation species not only for other plant species but other trophic levels, and these impacts are expressed through both direct and indirect effects associated with altered environmental conditions and localized productivity. Whilst this case study tests a limited subset of the membership of alpine animal communities, it clearly demonstrates that cushion-forming plant species are an important consideration in understanding resilience to global changes for many organisms in addition to other plants.

  10. Cushions of Thylacospermum caespitosum (Caryophyllaceae) do not facilitate other plants under extreme altitude and dry conditions in the north-west Himalayas.

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    de Bello, Francesco; Doležal, Jiří; Dvorský, Miroslav; Chlumská, Zuzana; Řeháková, Klára; Klimešová, Jitka; Klimeš, Leoš

    2011-09-01

    Cushion plants are commonly considered as keystone nurse species that ameliorate the harsh conditions they inhabit in alpine ecosystems, thus facilitating other species and increasing alpine plant biodiversity. A literature search resulted in 25 key studies showing overwhelming facilitative effects of different cushion plants and hypothesizing greater facilitation with increased environmental severity (i.e. higher altitude and/or lower rainfall). At the same time, emerging ecological theory alongside the cushion-specific literature suggests that facilitation might not always occur under extreme environmental conditions, and especially under high altitude and dryness. To assess these hypotheses, possible nursing effects of Thylacospermum caespitosum (Caryophyllaceae) were examined at extremely high altitude (5900 m a.s.l.) and in dry conditions (precipitation plants were detected. The number and abundance of species were greater outside cushions than within and on the edge of cushions. None of the 13 species detected was positively associated with cushions, while nine of them were negatively associated. Plant diversity increased with the size of the area sampled outside cushions, but no species-area relationship was found within cushions. The results support the emerging theoretical prediction of restricted facilitative effects under extreme combinations of cold and dryness, integrating these ideas in the context of the ecology of cushion plants. This evidence suggests that cases of missing strong facilitation are likely to be found in other extreme alpine conditions.

  11. Bacterial community of cushion plant Thylacospermum ceaspitosum on elevational gradient in the Himalayan cold desert.

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    Klára eŘeháková

    2015-04-01

    Full Text Available Although bacterial assemblages are important components of soils in arid ecosystems, the knowledge about composition, life-strategies and environmental drivers is still fragmentary, especially in remote high-elevation mountains. We compared the quality and quantity of heterotrophic bacterial assemblages between the rhizosphere of the dominant cushion-forming plant Thylacospermum ceaspitosum and its surrounding bulk soil in two mountain ranges (East Karakoram: 4850–5250 m and Little Tibet: 5350–5850 m, in communities from cold steppes to the subnival zone in Ladakh, arid Trans-Himalaya, northwest India. Bacterial communities were characterized by molecular fingerprinting in combination with culture-dependent methods. The effects of environmental factors (elevation, mountain range, and soil physico-chemical parameters on the bacterial community composition and structure were tested by multivariate redundancy analysis and conditional inference trees. Actinobacteria dominate the cultivable part of community and represent a major bacterial lineage of cold desert soils. The most abundant genera were Streptomyces, Arthrobacter and Paenibacillus, representing both r- and K- strategists. The soil texture is the most important factor for the community structure and the total bacteria counts. Less abundant and diverse assemblages are found in East Karakoram with coarser soils derived from leucogranite bedrock, while more diverse assemblages in Little Tibet are associated with finer soils derived from easily weathering gneisses. Cushion rhizosphere is in general less diverse than bulk soil, and contains more r-strategists. K-strategists are more associated with the extremes of the gradient, with drought at lowest elevations (4850 - 5000 m and frost at the highest elevations (5750 - 5850 m. The present study illuminates the composition of soil bacterial assemblages in relation to the cushion plant Thylacospermum ceaspitosum in a xeric environment and

  12. Carbohydrate reserves in the facilitator cushion plant Laretia acaulis suggest carbon limitation at high elevation and no negative effects of beneficiary plants.

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    García Lino, Mary Carolina; Cavieres, Lohengrin A; Zotz, Gerhard; Bader, Maaike Y

    2017-04-01

    The elevational range of the alpine cushion plant Laretia acaulis (Apiaceae) comprises a cold upper extreme and a dry lower extreme. For this species, we predict reduced growth and increased non-structural carbohydrate (NSC) concentrations (i.e. carbon sink limitation) at both elevational extremes. In a facilitative interaction, these cushions harbor other plant species (beneficiaries). Such interactions appear to reduce reproduction in other cushion species, but not in L. acaulis. However, vegetative effects may be more important in this long-lived species and may be stronger under marginal conditions. We studied growth and NSC concentrations in leaves and stems of L. acaulis collected from cushions along its full elevational range in the Andes of Central Chile. NSC concentrations were lowest and cushions were smaller and much less abundant at the highest elevation. At the lowest elevation, NSC concentrations and cushion sizes were similar to those of intermediate elevations but cushions were somewhat less abundant. NSC concentrations and growth did not change with beneficiary cover at any elevation. Lower NSC concentrations at the upper extreme contradict the sink-limitation hypothesis and may indicate that a lack of warmth is not limiting growth at high-elevation. At the lower extreme, carbon gain and growth do not appear more limiting than at intermediate elevations. The lower population density at both extremes suggests that the regeneration niche exerts important limitations to this species' distribution. The lack of an effect of beneficiaries on reproduction and vegetative performance suggests that the interaction between L. acaulis and its beneficiaries is probably commensalistic.

  13. Testing the stress-gradient hypothesis at the roof of the world: effects of the cushion plant Thylacospermum caespitosum on species assemblages.

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    Miroslav Dvorský

    Full Text Available Many cushion plants ameliorate the harsh environment they inhabit in alpine ecosystems and act as nurse plants, with significantly more species growing within their canopy than outside. These facilitative interactions seem to increase with the abiotic stress, thus supporting the stress-gradient hypothesis. We tested this prediction by exploring the association pattern of vascular plants with the dominant cushion plant Thylacospermum caespitosum (Caryophyllaceae in the arid Trans-Himalaya, where vascular plants occur at one of the highest worldwide elevational limits. We compared plant composition between 1112 pair-plots placed both inside cushions and in surrounding open areas, in communities from cold steppes to subnival zones along two elevational gradients (East Karakoram: 4850-5250 m and Little Tibet: 5350-5850 m. We used PERMANOVA to assess differences in species composition, Friedman-based permutation tests to determine individual species habitat preferences, species-area curves to assess whether interactions are size-dependent and competitive intensity and importance indices to evaluate plant-plant interactions. No indications for net facilitation were found along the elevation gradients. The open areas were not only richer in species, but not a single species preferred to grow exclusively inside cushions, while 39-60% of 56 species detected had a significant preference for the habitat outside cushions. Across the entire elevation range of T. caespitosum, the number and abundance of species were greater outside cushions, suggesting that competitive rather than facilitative interactions prevail. This was supported by lower soil nutrient contents inside cushions, indicating a resource preemption, and little thermal amelioration at the extreme end of the elevational gradient. We attribute the negative associations to competition for limited resources, a strong environmental filter in arid high-mountain environment selecting the stress

  14. Allergenic sesquiterpene lactones from cushion bush (Leucophyta brownii Cass.)

    DEFF Research Database (Denmark)

    Paulsen, Evy; Gade Hyldgaard, Mette; Andersen, Klaus E.

    2017-01-01

    BACKGROUND: The Australian cushion bush (Leucophyta brownii) of the Compositae family of plants has become a popular pot and container plant. The plant produces the sesquiterpene lactone allergen calocephalin. OBJECTIVES: To assess the sensitizing potential of sesquiterpene lactones from cushion ...

  15. Mapping sub-antarctic cushion plants using random forests to combine very high resolution satellite imagery and terrain modelling.

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    Phillippa K Bricher

    Full Text Available Monitoring changes in the distribution and density of plant species often requires accurate and high-resolution baseline maps of those species. Detecting such change at the landscape scale is often problematic, particularly in remote areas. We examine a new technique to improve accuracy and objectivity in mapping vegetation, combining species distribution modelling and satellite image classification on a remote sub-Antarctic island. In this study, we combine spectral data from very high resolution WorldView-2 satellite imagery and terrain variables from a high resolution digital elevation model to improve mapping accuracy, in both pixel- and object-based classifications. Random forest classification was used to explore the effectiveness of these approaches on mapping the distribution of the critically endangered cushion plant Azorella macquariensis Orchard (Apiaceae on sub-Antarctic Macquarie Island. Both pixel- and object-based classifications of the distribution of Azorella achieved very high overall validation accuracies (91.6-96.3%, κ = 0.849-0.924. Both two-class and three-class classifications were able to accurately and consistently identify the areas where Azorella was absent, indicating that these maps provide a suitable baseline for monitoring expected change in the distribution of the cushion plants. Detecting such change is critical given the threats this species is currently facing under altering environmental conditions. The method presented here has applications to monitoring a range of species, particularly in remote and isolated environments.

  16. Foam Cushioning

    Science.gov (United States)

    1988-01-01

    One innovation developed by a contractor at Ames Research Center was an open cell polymeric foam material with unusual properties. Intended as padding for aircraft seats the material offered better impact protection against accidents, and also enhanced passenger comfort because it distributed body weight evenly over the entire contact area. Called a slow springback foam, it flows to match the contour of the body pressing against it, and returns to its original shape once the pressure is removed. It has many applications including aircraft cushions and padding, dental stools, and athletic equipment. Now it's used by Dynamic Systems, Inc. for medical applications such as wheel chairs for severely disabled people which allow them to sit for 3-8 hours where they used to be uncomfortable in 15-30 minutes.

  17. Zero methane emission bogs : extreme rhizosphere oxygenation by cushion plants in Patagonia

    NARCIS (Netherlands)

    Fritz, Christian; Pancotto, Veronica A.; Elzenga, Josephus T.M.; Visser, Eric J.W.; Grootjans, Ab P.; Pol, Arjan; Iturraspe, Rodolfo; Roelofs, Jan G.M.; Smolders, Alfons J.P.

    2011-01-01

    Vascular wetland plants may substantially increase methane emissions by producing root exudates and easily degradable litter, and by providing a low-resistance diffusion pathway via their aerenchyma. However, model studies have indicated that vascular plants can reduce methane emission when soil oxy

  18. Nuclear air cushion vehicles.

    Science.gov (United States)

    Anderson, J. L.

    1973-01-01

    This paper serves several functions. It identifies the 'state-of-the-art' of the still-conceptual nuclear air cushion vehicle, particularly the nuclear powerplant. Using mission studies and cost estimates, the report describes some of the advantages of nuclear power for large air cushion vehicles. The paper also summarizes the technology studies on mobile nuclear powerplants and conceptual ACV systems/missions studies that have been performed at NASA Lewis Research Center.

  19. Methane-cycling microorganisms in soils of a high-alpine altitudinal gradient.

    Science.gov (United States)

    Hofmann, Katrin; Pauli, Harald; Praeg, Nadine; Wagner, Andreas O; Illmer, Paul

    2016-03-01

    Methanogens and methanotrophs play unique roles as producers and consumers of the greenhouse gas methane (CH4) in soils, respectively. Here, we aimed to reveal whether and to which extent methane-cyclers occur in high-alpine soils, and to assess their spatial distribution along an altitudinal gradient (2700-3500 m) in the Austrian Alps at sites located within the alpine (2700-2900 m), the alpine-nival (3000-3100 m) and the nival belts (3200-3500 m). Methanococcales and Methanocella spp. were most abundant among all quantified methanogenic guilds, whereas Methanosarcinales were not detected in the studied soil. The detected methanogens seem to be capable of persisting despite a highly oxic low-temperature environment. Methanogenic and methanotrophic activities and abundances of methanotrophs, Methanococcales and Methanocella spp. declined with altitude. Methanogenic and methanotrophic abundances were best explained by mean annual soil temperature and dissolved organic carbon, respectively. Alpine belt soils harbored significantly more methane-cyclers than those of the nival belt, indicating some influence of plant cover. Our results show that methanogens are capable of persisting in high-alpine cold soils and might help to understand future changes of these environments caused by climate warming.

  20. Importance of water quality on plant abundance and diversity in high-alpine meadows of the Yerba Loca Natural Sanctuary at the Andes of north-central Chile Importancia de la calidad del agua sobre la abundancia y diversidad vegetal en vegas altoandinas del Santuario Natural Yerba Loca en los Andes de Chile centro-norte

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    ROSANNA GINOCCHIO

    2008-12-01

    Full Text Available Porphyry Cu-Mo deposits have influenced surface water quality in high-Andes of north-central Chile since the Miocene. Water anomalies may reduce species abundance and diversity in alpine meadows as acidic and metal-rich waters are highly toxic to plants The study assessed the importance of surface water quality on plant abundance and diversity in high-alpine meadows at the Yerba Loca Natural Santuary (YLNS, central Chile (33°15' S, 70°18' W. Hydrochemical and plant prospecting were carried out on Piedra Carvajal, Chorrillos del Plomo and La Lata meadows the growing seasons of 2006 and 2007. Direct gradient analysis was performed through canonical correspondence analysis (CCA to look for relationships among water chemistry and plant factors. High variability in water chemistry was found inside and among meadows, particularly for pH, sulphate, electric conductivity, hardness, and total dissolved Cu, Zn, Cd, Pb and Fe. Data on species abundance and water chemical factors suggests that pH and total dissolved Cu are very important factor determining changes in plant abundance and diversity in study meadows. For instance, Festuca purpurascens, Colobanthus quitensis, and Arenaria rivularis are abundant in habitals with Cu-rich waters while Festuca magellanica, Patosia clandestina, Plantago barbata, Werneria pygmea, and Erigeron andícola are abundant in habitals with dilute waters.Los megadepósitos de pórfidos de Cu-Mo han influido sobre la calidad de las aguas superficiales en las zonas altoandinas del centro-norte de Chile desde el Mioceno. Estas alteraciones en la calidad de las aguas podrían afectar negativamente a la vegetación presente en las vegas altoandinas, ya que las aguas acidas y ricas en metales son altamente tóxicas para las plantas. En este estudio se evaluó el efecto de la calidad de las aguas en la abundancia y diversidad florística de las vegas altoandinas del Santuario de la Naturaleza Yerba Loca (SNYL, en Chile central (33

  1. The constitutive sofa cushion

    DEFF Research Database (Denmark)

    Hanghøj, Sara

    2009-01-01

    , with the sitting room as a cultural and informal environment as its arena in 2006. The local and social network of the informant (born 1919) is traced through a detailed cultural analysis of the creation, usage and existence of the sofa cushion, including even the material interactions occurring between the human...... body, space and artefact, thereby revealing the materialization process. Based on results of the analysis, ANT (Actor-Network- Theory) is used in order to discuss how The Danish Folk High School's conception of simplicity as an aesthetic and gendered ideal in the formal education of female handcraft...

  2. Karst morphology and groundwater vulnerability of high alpine karst plateaus

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    Plan, Lukas; Decker, Kurt; Faber, Robert; Wagreich, Michael; Grasemann, Bernhard

    2009-07-01

    High alpine karst plateaus are recharge areas for major drinking water resources in the Alps and many other regions. Well-established methods for the vulnerability mapping of groundwater to contamination have not been applied to such areas yet. The paper characterises this karst type and shows that two common vulnerability assessment methods (COP and PI) classify most of the areas with high vulnerability classes. In the test site on the Hochschwab plateau (Northern Calcareous Alps, Austria), overlying layers are mostly absent, not protective or even enhance point recharge, where they have aquiclude character. The COP method classifies 82% of the area as highly or extremely vulnerable. The resulting maps are reasonable, but do not differentiate vulnerabilities to the extent that the results can be used for protective measures. An extension for the upper end of the vulnerability scale is presented that allows identifying ultra vulnerable areas. The proposed enhancement of the conventional approach points out that infiltration conditions are of key importance for vulnerability. The method accounts for karst genetical and hydrologic processes using qualitative and quantitative properties of karst depressions and sinking streams including parameters calculated from digital elevations models. The method is tested on the Hochschwab plateau where 1.7% of the area is delineated as ultra vulnerable. This differentiation could not be reached by the COP and PI methods. The resulting vulnerability map highlights spots of maximum vulnerability and the combination with a hazard map enables protective measures for a manageable area and number of sites.

  3. Air cushion vehicles: A briefing

    Science.gov (United States)

    Anderson, J. L.; Finnegan, P. M.

    1971-01-01

    Experience and characteristics; the powering, uses, and implications of large air cushion vehicles (ACV); and the conceptual design and operation of a nuclear powered ACV freighter and supporting facilities are described.

  4. EXPLORING THE POTENTIAL OF AERIAL PHOTOGRAMMETRY FOR 3D MODELLING OF HIGH-ALPINE ENVIRONMENTS

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    K. Legat

    2016-03-01

    Based on the very promising results, some general recommendations for aerial photogrammetry processing in high-alpine areas are made to achieve best possible accuracy of the final 3D-, 2.5D- and 2D products.

  5. Floristic changes in alpine plant communities induced by the cushion plant Azorella madreporica (Apiaceae in the Andes of central Chile Cambios florísticos en comunidades de plantas alpinas inducidos por la planta en cojín Azorella madrepórica (Apiaceae en los Andes de Chile central

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    CONSTANZA L QUIROZ

    2009-06-01

    Full Text Available It is well known that the number of plant species associated with nurse plants increases with elevation. However, studies conducted so far have largely ignored the effect of nurse plants on other community attributes, such as the species abundances, diversity and evenness. Moreover, changes in these community attributes along environmental gradients have also been seldom examined. The present study evaluates the effect of the cushion plant Azorella madrepórica (Apiaceae on species richness, species abundance, diversity and evenness of vascular plants at two elevations in the Andes of central Chile. Theoretically, the impact of this nurse cushion plant on these community attributes should be grater at a higher elevation. Results showed that the proportion of plant species associated with cushion plants increases with elevation, and the abundance of some species is also greater within cushions than on bare ground. Although the proportion of species growing within cushions increased with elevation, diversity and evenness were higher on bare ground. This is due to some few species that attained very high densities within cushions, generating assemblages highly dominated by some few species. Ordination analyses indicated differences in species assemblages within and outside A. madrepórica at the higher elevation. Therefore, the influence of cushion plants on community structure changes with elevation. Accordingly, we suggest that attributes other than species richness must be included in future studies in order to analyze the impact of nurse species on community structure along environmental gradients.Se sabe que el número de especies asociado a plantas nodrizas aumenta con la altitud. Sin embargo, el efecto de plantas nodrizas sobre otros atributos de las comunidades, como la abundancia de especies, diversidad y equidad, ha sido largamente ignorado. Más aún, cambios en estos atributos en gradientes ambientales han sido pocas veces examinados

  6. Wheelchair cushions: a historical review.

    Science.gov (United States)

    Garber, S L

    1985-07-01

    An important objective of occupational therapy practice is to maximise functional potential in patients who have physical disabilities. Pressure sores are a major complication in the medical course of these individuals. Therefore, prevention, or at least the proper management, of these sores becomes an important focus for occupational therapists who treat the physically disabled patient. Occupational therapists often prescribe wheelchair cushions to relieve pressure and reduce the risk of ulceration. Unfortunately, occupational therapy literature offers few articles dealing with this significant problem. This paper presents a historical review of wheelchair cushions and details some of the physiological and clinical research efforts that are the basis of prescription practice today.

  7. Study on Spiral Case with Elastic Cushion Layer of Large-scale Hydropower Plant Building%大型水电站厂房弹性垫层蜗壳结构研究

    Institute of Scientific and Technical Information of China (English)

    宋艳清

    2011-01-01

    钢蜗壳与外围混凝土之间设置弹性垫层是我国大型水电站厂房常采用的一种结构型式,鉴于弹性垫层的最优摩擦系数以及内水压力向外围混凝土传递机理的不确定性,应用ANSYS有限元程序对某大型水电站垫层蜗壳进行钢衬-钢筋混凝土结构三维非线性有限元仿真研究,考虑钢蜗壳与外围混凝土之间的滑移接触特性,研究钢蜗壳与混凝土之间合理的摩擦系数,深入研究蜗壳各径向断面外围混凝土应力、内水压力传递比、承载比等关键问题,为大型水电站厂房的设计研究提供可靠的理论分析.%The elastic cushion layer between the steel spiral case and surrounding concrete is often used as a structural type in the large-scale hydropower plant in China. In view of the uncertainty of the optimal elastic coefficient of friction and the transfer mechanism of internal water pressure to the surrounding concrete, the spiral case with cushion layer of a large-scale hydropower plant is simulated with ANSYS nonlinear finite element program. Then considering the slip contact characteristics between the steel spiral case and surrounding concrete, the more reasonable coefficient of friction between them is studied. At the same time, the key problems for the outer concrete volute stress and the transfer ratio of water pressure and bearing ratio are also studied deeply. All these as mentioned above could provide reliable and theoretical analysis for the design of large-scale hydropower plants.

  8. A deposition record of inorganic ions from a high-alpine glacier

    Energy Technology Data Exchange (ETDEWEB)

    Huber, T. [Bern Univ. (Switzerland); Bruetsch, S.; Gaeggeler, H.W.; Schotterer, U.; Schwikowski, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    The lowest five metres of an ice core from a high-alpine glacier (Colle Gnifetti, Monte Rosa massif, 4450m a.s.l., Switzerland) were analysed for ammonium, calcium, chloride, magnesium, nitrate, potassium, sodium, and sulphate by ion chromatography. (author) 1 fig., 3 refs.

  9. Air cushion vehicles for arctic operation

    Science.gov (United States)

    Koleser, J.; Lavis, D. R.

    1986-09-01

    Attention is given to the results of the NAVSEA FY85 Surface Ship Concept Formulation Design Study for an initial operational capability year-2000 air cushion vehicle (ACV) suitable for logistics and general search/rescue duties in the Arctic. Two designs were developed during the study; the first utilized an ACV design synthesis math model while the second evolved as a derivative of an existing U.S. production craft. Both are regarded as feasible from an engineering and naval architectural standpoint. Results of performance and cost trade-off studies suggest that, for an Arctic ACV, gas turbines are the preferred power plant choice and an aluminum alloy is the preferred hull structural material choice. The most appropriate skirt height is approximately 12 ft.

  10. Molecular genetics and diversity of primary biogenic aerosol particles in urban, rural, and high-alpine air

    Directory of Open Access Journals (Sweden)

    V. Després

    2007-02-01

    Full Text Available This study explores the applicability of molecular methods for the characterization of primary biogenic aerosol (PBA particles in the atmosphere. Samples of fine particulate matter (PM2.5 and total suspended particulates (TSP have been collected on different types of filter materials at urban, rural, and high-alpine locations along an altitude transect in the south of Germany (Munich, Hohenpeissenberg, Mt. Zugspitze.

    From filter aliquots loaded with about one milligram of air particulate matter, DNA could be extracted and DNA sequences could be determined for bacteria, fungi, plants and animals. Sequence analyses were used to determine the identity of biological organisms, and terminal restriction length polymorphism analyses (T-RFLP were applied to estimate diversities and relative abundances of bacteria. Investigations of blank and background samples showed that filter materials have to be decontaminated prior to use, and that the sampling and handling procedures have to be carefully controlled to avoid artifacts in the analyses.

    Mass fractions of DNA in PM2.5 were found to be around 0.05% in urban, rural, and high alpine aerosols. The average concentration of DNA determined for urban air was on the order of ~7 ng m−3, indicating that human adults may inhale about one microgram of DNA per day (corresponding to ~105 haploid human genomes.

    Most of the bacterial sequences found in PM2.5 were from Proteobacteria (42 and some from Actinobacteria (10 and Firmicutes (1. The fungal sequences were characteristic for Ascomycota (3 and Basidiomycetes (1, which are known to actively discharge spores into the atmosphere. The plant sequences could be attributed to green plants (2 and moss spores (2, while animal DNA was found only for one unicellular eukaryote (protist.

    Over 80% of the 53 bacterial sequences could be matched with about 40% of the 19 T-RF peaks (58

  11. Exploring the Potential of Aerial Photogrammetry for 3d Modelling of High-Alpine Environments

    Science.gov (United States)

    Legat, K.; Moe, K.; Poli, D.; Bollmannb, E.

    2016-03-01

    High-alpine areas are subject to rapid topographic changes, mainly caused by natural processes like glacial retreat and other geomorphological processes, and also due to anthropogenic interventions like construction of slopes and infrastructure in skiing resorts. Consequently, the demand for highly accurate digital terrain models (DTMs) in alpine environments has arisen. Public administrations often have dedicated resources for the regular monitoring of glaciers and natural hazard processes. In case of glaciers, traditional monitoring encompasses in-situ measurements of area and length and the estimation of volume and mass changes. Next to field measurements, data for such monitoring programs can be derived from DTMs and digital ortho photos (DOPs). Skiing resorts, on the other hand, require DTMs as input for planning and - more recently - for RTK-GNSS supported ski-slope grooming. Although different in scope, the demand of both user groups is similar: high-quality and up-to-date terrain data for extended areas often characterised by difficult accessibility and large elevation ranges. Over the last two decades, airborne laser scanning (ALS) has replaced photogrammetric approaches as state-of-the-art technology for the acquisition of high-resolution DTMs also in alpine environments. Reasons include the higher productivity compared to (manual) stereo-photogrammetric measurements, canopy-penetration capability, and limitations of photo measurements on sparsely textured surfaces like snow or ice. Nevertheless, the last few years have shown strong technological advances in the field of aerial camera technology, image processing and photogrammetric software which led to new possibilities for image-based DTM generation even in alpine terrain. At Vermessung AVT, an Austrian-based surveying company, and its subsidiary Terra Messflug, very promising results have been achieved for various projects in high-alpine environments, using images acquired by large-format digital

  12. Column Water Vapour using a PFR Radiometer at a High-Alpine Site

    Science.gov (United States)

    Nyeki, S.; Vuilleumier, L.; Heimo, A.; Kämpfer, N.; Mätzler, C.; Vernez, A.; Viatte, P.

    2003-04-01

    The Swiss Atmospheric Radiation Monitoring program (CHARM) integrates a number of solar and atmospheric radiation monitoring tasks within the Swiss contribution to GAW (Global Atmosphere Watch) of the WMO. Columnar water vapor (CWV) is derived from sun photometers at four locations within the CHARM network. A four-year dataset of CWV measured at the Jungfraujoch high-alpine research station (3580 m asl, Switzerland) using a Precision Filter Radiometer (PFR) is reported. Observations indicated that CWV above station altitude varied between 1 and 4 (+/- 1) kg.m-2 in winter and summer, respectively, confirming an earlier 12-month study in 1999.

  13. Multi-method investigation of cushion peatlands (

    Science.gov (United States)

    Forbriger, M.; Schittek, K.; Höfle, B.; Siart, C.; Eitel, B.

    2012-04-01

    This study presents a multi-method and multi-proxy approach for palaeonvironmental investigations in the western andean cordillera of southern Peru (Lucanas province, 14° S) using cushion peatlands as terrestrial geoarchives. The region stretching between the Altiplano and the Peruvian desert in the lowland shares a long term settlement history, in which local cultures adapted to climate change in many different ways. Being one of the most outstanding human remains, the abri below Cerro Llamoca, 4.450 m a.s.l. in the uppermost ranges of the Llamoca peatland catchment area further reveals an occupation history of almost 10.000 years, as revealed by latest archaeological investigations. In remote and highly elevated regions such as the central Andes, cushion peatlands basically represent the only high resolution terrestrial archives suitable for geoarchaeological and palaeoenvironmental studies. Characterized by high accumulation rates, they ideally document environmental changes, particularly at small time intervals. Within the multidisciplinary project 'Andean Transect - Climate Sensitivity of pre-Columbian Man-Environment-Systems' several sediment cores with depths up to 11.5 m b.s. were recovered from the Llamoca peatland. Based on almost 100 AMS 14C-datings they provide a chronology of 8000 years and, thus, offer profound insights into climatic and environmental changes in the study area. While nearly homogeneous peat layers record stable environmental conditions, the heterogeneous granulometric composition of intercalated sediment layers documents several periods of intense geomorphodynamic activity. Due to high resolution geochemical analyses of peat layers (1 cm interval; humification degree, CNS measurements, XRF-scanning), the existence of slight and short-term trends of landscape development during these phases can be identified. Additional pollen, charred particles and plant macrofossil analyses confirm these findings and help reconstructing local

  14. Size class structure, growth rates, and orientation of the central Andean cushion Azorella compacta

    Directory of Open Access Journals (Sweden)

    Catherine Kleier

    2015-03-01

    Full Text Available Azorella compacta (llareta; Apiaceae forms dense, woody, cushions and characterizes the high elevation rocky slopes of the central Andean Altiplano. Field studies of an elevational gradient of A. compacta within Lauca National Park in northern Chile found a reverse J-shape distribution of size classes of individuals with abundant small plants at all elevations. A new elevational limit for A. compacta was established at 5,250 m. A series of cushions marked 14 years earlier showed either slight shrinkage or small degrees of growth up to 2.2 cm yr−1. Despite their irregularity in growth, cushions of A. compacta show a strong orientation, centered on a north-facing aspect and angle of about 20° from horizontal. This exposure to maximize solar irradiance closely matches previous observations of a population favoring north-facing slopes at a similar angle. Populations of A. compacta appear to be stable, or even expanding, with young plants abundant.

  15. Size class structure, growth rates, and orientation of the central Andean cushion Azorella compacta

    Science.gov (United States)

    Trenary, Tim; Graham, Eric A.; Stenzel, William; Rundel, Philip W.

    2015-01-01

    Azorella compacta (llareta; Apiaceae) forms dense, woody, cushions and characterizes the high elevation rocky slopes of the central Andean Altiplano. Field studies of an elevational gradient of A. compacta within Lauca National Park in northern Chile found a reverse J-shape distribution of size classes of individuals with abundant small plants at all elevations. A new elevational limit for A. compacta was established at 5,250 m. A series of cushions marked 14 years earlier showed either slight shrinkage or small degrees of growth up to 2.2 cm yr−1. Despite their irregularity in growth, cushions of A. compacta show a strong orientation, centered on a north-facing aspect and angle of about 20° from horizontal. This exposure to maximize solar irradiance closely matches previous observations of a population favoring north-facing slopes at a similar angle. Populations of A. compacta appear to be stable, or even expanding, with young plants abundant. PMID:25802811

  16. KCP Activities Supporting the W76LEP Stress Cushions and LK3626 RTV Replacement Material Development

    Energy Technology Data Exchange (ETDEWEB)

    J. W. Schneider

    2009-10-01

    The S-5370 RTV blown foam previously produced by Dow Corning is no longer commercially available. The S-5370 material has been used on all of Los Alamos National Laboratory (LANL) programs to manufacture Stress Cushions up through the W88. The Kansas City Plant (KCP) did not have a sufficient supply of S-5370 material to cover the schedule requirements for the Program. This report provides information on the numerous activities conducted at KCP involving the development of the Program Stress Cushion and replacement RTV material.

  17. Mechanical Cushion Design Influence on Cylinder Dynamics

    DEFF Research Database (Denmark)

    Borghi, Massimo; Milani, Massimo; Conrad, Finn

    2005-01-01

    The paper deals with the simulation and the experimental verification of the dynamic behaviour of a linear actuator equipped with different configurations of mechanical cushion. A numerical model, developed and tailored to describe the influence of different modulation of the discharged flow-rate...

  18. Ecological implications of reduced pollen deposition in alpine plants: a case study using a dominant cushion plant species [v1; ref status: indexed, http://f1000r.es/3mb

    Directory of Open Access Journals (Sweden)

    Anya Reid

    2014-06-01

    Full Text Available The reproductive assurance hypothesis states that self-incompatible female plants must produce twice the number of seeds relative to their self-compatible hermaphroditic counterparts to persist in gynodioecious populations. This is a viable life-history strategy, provided that pollination rates are sufficiently high. However, reduced pollination rates in alpine plants are likely due to climate induced plant-pollinator mismatches and general declines in pollinators. Using a gynodioecious population of the dominant plant Silene acaulis (Caryophyllaceae, we tested the reproductive assurance hypothesis and also the stress gradient hypothesis with a series of pollinator exclusion trials and extensive measurements of subsequent reproductive output (gender ratio, plant size, percent fruit-set, fruit weight, seeds per fruit, total seeds, seed weight, and seed germination. The reproductive assurance hypothesis was supported with female plants being more sensitive to and less likely to be viable under reductions in pollination rates. These findings are the first to show that the stress gradient hypothesis is also supported under a gradient of pollen supply instead of environmental limitations. Beneficiary abundance was negatively correlated to percent fruit-set under current pollen supply, but became positive under reduced pollen supply suggesting that there are important plant-plant-pollinator interactions related to reproduction in these alpine plant species.

  19. Eight hundred years of environmental changes in a high Alpine lake (Gossenköllesee, Tyrol inferred from sediment records

    Directory of Open Access Journals (Sweden)

    Roland PSENNER

    2000-09-01

    Full Text Available Documentary and sediment records (diatoms, chrysophyte stomatocysts, plant pigments, carbon and nitrogen, metals and mineral magnetics were used to reconstruct environmental changes in the high alpine lake Gossenköllesee (Tyrol, Austria during the last 800 years. The records revealed complex interactions between human impact and climate. Gossenköllesee was predominantly influenced by land-use, which supplied nutrients to the lake. Documentary records report intensive sheep and cattle farming in the area around Gossenköllesee during medieval times. Pigments and chrysophyte stomatocysts indicated high nutrient concentrations prior to ca 1770 AD. First changes in land-use, however, were already detected ca 1670 AD. In 1675 AD the “Schwaighof” near Gossenköllesee, a perennial high altitude settlement, was sold to the Earl of Spaur, and farm management probably changed. After approx. 1770 AD in-lake production was reduced, indicating a decrease in land-use. According to historical records, the perennial settlement near Gossenköllesee was abandoned by at least 1890 AD. Gossenköllesee was also affected by fish stocking. Arctic charr (Salmo trutta morpha fario L. was introduced into the lake, most probably at the end of the 15th century. A decline in carbon, nitrogen and the pigments alloxanthin (cryptophytes and astaxanthin (grazers indicate a significant removal of grazers by fish. Superimposed on human activity, climate changes have also had a significant impact on Gossenköllesee. High productivity during the 12th century suggested by the plant pigment records might have been favoured by temperature increases, indicated by pronounced glacier retreats which began during the 10th/11th century. The “Schwaighof” near Gossenköllesee was sold to the Earl of Spaur when winter temperatures declined substantially in the 1670s. Changes in C/N ratio, iron, manganese and mineral magnetics indicated increased detrital input from the catchment

  20. [Pressure ulcer prevention with pressure-reducing seat cushions].

    Science.gov (United States)

    Reijnen, Guido; Heule, Freerk

    2012-01-01

    Analysis of the effectiveness of pressure-reducing seat cushions. Literature review. Investigation of the literature yielded 8 relevant studies. These studies encompassed three clinical trials with a total of 296 patients, and five laboratory experiments with a total of 107 subjects, including patients. The publications were written at level A (RCT and meta-analysis) and level B (other study forms) according to the principles of evidence-based medicine. Both the pressure parameters of the pressure-reducing seat cushion and the development of pressure ulcers were used as measures for outcome. A 7.6 cm foam cushion was used as reference; it was not considered as one of the pressure-reducing systems. Two studies compared different types of air seat cushions with a foam/gel seat cushion. The best distribution of pressure was found for the air compartment seat cushion. This type of seat cushion provided the smallest contact surface with high pressures. Three studies compared the pressure-reducing systems with a 7.6 cm foam cushion. The methodologically most solid one of these three studies found a lower incidence of sitting-related pressure ulcers for users of a pressure-reducing system (0.9 vs. 6.7%; p = 0.04). The two other studies had too low a power to show significant differences. These two compared different types of foam/gel seat cushions and a low profile air seat cushion and found no significant differences in distribution of pressures. One study compared various foam cushions of differing thickness and found that foam cushions most optimally distributed pressure at a thickness of 8 centimetres. Pressure-reducing systems are effective in preventing pressure ulcers. Within the group of pressure-reducing systems, the air compartment seat cushion has the best pressure-distributing properties.

  1. Fire resistant resilient foams. [for seat cushions

    Science.gov (United States)

    Gagliani, J.

    1976-01-01

    Primary program objectives were the formulation, screening, optimization and characterization of open-cell, fire resistant, low-smoke emitting, thermally stable, resilient polyimide foams suitable for seat cushions in commercial aircraft and spacecraft. Secondary program objectives were to obtain maximum improvement of the tension, elongation and tear characteristics of the foams, while maintaining the resiliency, thermal stability, low smoke emission and other desirable attributes of these materials.

  2. Performance of Used Tire Cushion Layer under Rockfall Impact

    Directory of Open Access Journals (Sweden)

    Jianhu Sun

    2016-01-01

    Full Text Available Rock shed is widely used in traffic lines against rockfall. In order to cushion rockfall impact and dissipate impact energy, cushion layer is usually adopted in rock shed. Used tire cushion layer is proposed in this paper and it can cushion rockfall impact utilizing large radial deformation of tire. Reinforced concrete structure model is built with used tire cushion layer and artificial rockfall test is carried out. Twelve tests are divided into 4 sets with different rockfall mass, rockfall height, and tire filling material. Simplified calculation model with spring-damper is derived from radial repeated compression test of used tire, which improves the calculation efficiency. Test and numerical simulation show that application of used tire cushion layer in rock shed can cushion rockfall impact and effectively reduce peak acceleration and the maximum impact force. Filling sand and gravel in tire can improve tire stiffness and energy absorption capacity but will decrease cushion effect due to its large density. With the same impact energy, light rockfall is more destructive than weight rockfall for used tire cushion layer.

  3. Wheelchair cushions for persons with spinal cord injury: an update.

    Science.gov (United States)

    Garber, S L; Dyerly, L R

    1991-06-01

    Occupational therapists frequently prescribe wheelchair cushions to reduce the risk of pressure sores in patients with spinal cord injury. In an earlier study (Garber, 1985b), Roho cushions were prescribed for the greatest number of subjects studied. The present study of 197 subjects updates these data and describes current prescription patterns, the use of cushions over time, satisfaction with prescribed cushions, and the occurrence of pressure sores with prescribed cushions. The study shows that the Jay cushion was prescribed most frequently for the current subjects, although it was not recommended for all persons with spinal cord injury. In the second phase of the present study, involving 30 subjects, 30% of the subjects discontinued use of the prescribed cushion. Skin breakdown and the discovery of alternative solutions were given as primary reasons. There was no significant difference in the incidence of pressure sores between subjects who continued to use their prescribed cushions and those who did not. This research supports the conclusion of earlier studies that no one wheelchair cushion is universally effective for all persons and that individual evaluation and routine reassessment are essential in reducing the occurrence of pressure sores.

  4. Investigating the Microscopic Location of Trace Elements in High-Alpine Glacier Ice

    Science.gov (United States)

    Avak, Sven Erik; Birrer, Mario; Laurent, Oscar; Guillong, Marcel; Wälle, Markus; Jenk, Theo Manuel; Bartels-Rausch, Thorsten; Schwikowski, Margit; Eichler, Anja

    2017-04-01

    Past changes in atmospheric pollution can be reconstructed from high-alpine ice core trace element records (Schwikowski et al., 2004). Percolation of meltwater alters the information originally stored in these environmental archives. Eichler et al. (2001) suggested that the preservation of major ions with respect to meltwater percolation depends on their location in the crystal ice lattice, i.e. grain boundaries versus grain interiors. Other studies have also focused on the effect of meltwater on organic pollutant concentrations as well as on stable isotope profiles in ice cores, whereas no information exists about trace elements. Here, we investigate for the first time the effect of the microscopic location of anthropogenic, dust and volcanic related trace elements on the behavior during meltwater percolation by using two different approaches. On the one hand we assess the microscopic location of trace elements indirectly by analyzing trace element concentrations in a high-alpine ice core, which has been shown to be affected by an inflow of meltwater, using discrete inductively coupled plasma mass spectrometry (ICP-MS). Impurities located at grain boundaries are prone to be removed by meltwater and tend to be depleted in the affected section of the record whereas those incorporated into the ice interior are preserved and not disturbed in the record. In the second approach we work towards a direct quantification of differences in concentrations of trace elements between ice grain boundaries and grain interiors in samples both from unaffected and affected sections of this ice core. Therefore we use cryocell laser ablation (LA) ICP-MS, which is the method of choice for the direct in situ chemical analysis of trace elements at a sub-millimeter resolution in glacier ice (Reinhardt et al., 2001, Della Lunga et al., 2014, Sneed et al., 2015). We will present first results of both approaches with regard to the evaluation of the potential of trace elements as environmental

  5. The origins of ice crystals measured in mixed phase clouds at High-Alpine site Jungfraujoch

    Directory of Open Access Journals (Sweden)

    G. Lloyd

    2015-07-01

    Full Text Available During the winter of 2013 and 2014 measurements of cloud microphysical properties over a five week period at the high Alpine site Jungfraujoch, Switzerland were carried out as part of the Cloud Aerosol Characterisation Experiments (CLACE and the Ice Nucleation Process Investigation and Quantification project (INUPIAQ Measurements of aerosol properties at a second, lower site, Schilthorn, Switzerland, were used as input for a primary ice nucleation scheme to predict ice nuclei concentrations at Jungfraujoch Frequent, rapid transitions in the ice and liquid properties of the clouds at Jungfraujoch were identified that led to large fluctuations in ice mass fractions over temporal scales of seconds to hours. During the measurement period we observed high concentrations of ice particles that exceeded 1000 L−1 at temperatures around −15 °C, verified by multiple instruments These concentrations could not be explained using the usual primary ice nucleation schemes, which predicted ice nucleus concentrations several orders of magnitude smaller than the peak ice crystal number concentrations. Secondary ice production through the Hallet–Mossop process as a possible explanation was ruled out, as the cloud was rarely within the active temperature range for this process It is shown that other mechanisms of secondary ice particle production cannot explain the highest ice particle concentrations. We describe 4 possible mechanisms that could lead to high cloud ice concentrations generated from the snow covered surfaces surrounding the measurement site. Of these we show that hoar frost crystals generated at the cloud enveloped snow surface could be the most important source of cloud ice concentrations Blowing snow was also observed to make significant contributions at higher wind speeds when ice crystal concentrations were −1.

  6. Measured and modelled cloud condensation nuclei number concentration at the high alpine site Jungfraujoch

    Directory of Open Access Journals (Sweden)

    Z. Jurányi

    2010-08-01

    Full Text Available Atmospheric aerosol particles are able to act as cloud condensation nuclei (CCN and are therefore important for the climate and the hydrological cycle, but their properties are not fully understood. Total CCN number concentrations at 10 different supersaturations in the range of SS=0.12–1.18% were measured in May 2008 at the remote high alpine research station, Jungfraujoch, Switzerland (3580 m a.s.l.. In this paper, we present a closure study between measured and predicted CCN number concentrations. CCN predictions were done using dry number size distribution (scanning particle mobility sizer, SMPS and bulk chemical composition data (aerosol mass spectrometer, AMS, and multi-angle absorption photometer, MAAP in a simplified Köhler theory. The predicted and the measured CCN number concentrations agree very well and are highly correlated. A sensitivity study showed that the temporal variability of the chemical composition at the Jungfraujoch can be neglected for a reliable CCN prediction, whereas it is important to know the mean chemical composition. The exact bias introduced by using a too low or too high hygroscopicity parameter for CCN prediction was further quantified and shown to be substantial for the lowest supersaturation.

    Despite the high average organic mass fraction (~45% in the fine mode, there was no indication that the surface tension was substantially reduced at the point of CCN activation. A comparison between hygroscopicity tandem differential mobility analyzer (HTDMA, AMS/MAAP, and CCN derived κ values showed that HTDMA measurements can be used to determine particle hygroscopicity required for CCN predictions if no suitable chemical composition data are available.

  7. Measured and modelled cloud condensation nuclei concentration at the high alpine site Jungfraujoch

    Science.gov (United States)

    Jurányi, Z.; Gysel, M.; Weingartner, E.; Decarlo, P. F.; Kammermann, L.; Baltensperger, U.

    2010-04-01

    Atmospheric aerosol particles are able to act as cloud condensation nuclei (CCN) and are therefore important for the climate and the hydrological cycle, but their properties are not fully understood. Total CCN number concentrations at 10 different supersaturations in the range of SS = 0.12-1.18% were measured in May 2008 at the remote high alpine research station, Jungfraujoch, Switzerland (3580 m asl.). In this paper, we present a closure study between measured and predicted CCN number concentrations. CCN predictions were done using number size distribution (scanning particle mobility sizer, SMPS) and bulk chemical composition data (aerosol mass spectrometer, AMS, and multi-angle absorption photometer, MAAP) in a simplified Köhler theory. The predicted and the measured CCN concentrations agree very well and are highly correlated. A sensitivity study showed that the temporal variability of the chemical composition at the Jungfraujoch can be neglected for a reliable CCN prediction, whereas it is important to know the mean chemical composition. The exact bias introduced by using a too low or too high hygroscopicity parameter for CCN prediction was further quantified and shown to be substantial for the lowest supersaturation. Despite the high average organic mass fraction (45%) during the measurement campaign, there was no indication that the surface tension was substantially reduced at the point of CCN activation. A comparison between hygroscopicity tandem differential mobility analyzer (HTDMA), AMS/MAAP, and CCN derived κ values showed that HTDMA measurements can be used as a chemical composition proxy for CCN predictions if no suitable chemical composition data are available.

  8. Measured and modelled cloud condensation nuclei concentration at the high alpine site Jungfraujoch

    Directory of Open Access Journals (Sweden)

    Z. Jurányi

    2010-04-01

    Full Text Available Atmospheric aerosol particles are able to act as cloud condensation nuclei (CCN and are therefore important for the climate and the hydrological cycle, but their properties are not fully understood. Total CCN number concentrations at 10 different supersaturations in the range of SS = 0.12–1.18% were measured in May 2008 at the remote high alpine research station, Jungfraujoch, Switzerland (3580 m asl.. In this paper, we present a closure study between measured and predicted CCN number concentrations. CCN predictions were done using number size distribution (scanning particle mobility sizer, SMPS and bulk chemical composition data (aerosol mass spectrometer, AMS, and multi-angle absorption photometer, MAAP in a simplified Köhler theory. The predicted and the measured CCN concentrations agree very well and are highly correlated. A sensitivity study showed that the temporal variability of the chemical composition at the Jungfraujoch can be neglected for a reliable CCN prediction, whereas it is important to know the mean chemical composition. The exact bias introduced by using a too low or too high hygroscopicity parameter for CCN prediction was further quantified and shown to be substantial for the lowest supersaturation.

    Despite the high average organic mass fraction (45% during the measurement campaign, there was no indication that the surface tension was substantially reduced at the point of CCN activation. A comparison between hygroscopicity tandem differential mobility analyzer (HTDMA, AMS/MAAP, and CCN derived κ values showed that HTDMA measurements can be used as a chemical composition proxy for CCN predictions if no suitable chemical composition data are available.

  9. Measured and modelled cloud condensation nuclei number concentration at the high alpine site Jungfraujoch

    Science.gov (United States)

    Jurányi, Z.; Gysel, M.; Weingartner, E.; Decarlo, P. F.; Kammermann, L.; Baltensperger, U.

    2010-08-01

    Atmospheric aerosol particles are able to act as cloud condensation nuclei (CCN) and are therefore important for the climate and the hydrological cycle, but their properties are not fully understood. Total CCN number concentrations at 10 different supersaturations in the range of SS=0.12-1.18% were measured in May 2008 at the remote high alpine research station, Jungfraujoch, Switzerland (3580 m a.s.l.). In this paper, we present a closure study between measured and predicted CCN number concentrations. CCN predictions were done using dry number size distribution (scanning particle mobility sizer, SMPS) and bulk chemical composition data (aerosol mass spectrometer, AMS, and multi-angle absorption photometer, MAAP) in a simplified Köhler theory. The predicted and the measured CCN number concentrations agree very well and are highly correlated. A sensitivity study showed that the temporal variability of the chemical composition at the Jungfraujoch can be neglected for a reliable CCN prediction, whereas it is important to know the mean chemical composition. The exact bias introduced by using a too low or too high hygroscopicity parameter for CCN prediction was further quantified and shown to be substantial for the lowest supersaturation. Despite the high average organic mass fraction (~45%) in the fine mode, there was no indication that the surface tension was substantially reduced at the point of CCN activation. A comparison between hygroscopicity tandem differential mobility analyzer (HTDMA), AMS/MAAP, and CCN derived κ values showed that HTDMA measurements can be used to determine particle hygroscopicity required for CCN predictions if no suitable chemical composition data are available.

  10. Air cushion vehicles - Any potential for Canada?

    Science.gov (United States)

    Laframboise, J. F.

    1987-09-01

    The present evaluation of air cushion vehicle (ACV) operational and commercial suitability in the Canadian context notes that the most successful and durable ACV applications are those in which only ACVs can perform the required mission. An important factor is the reliability of the craft being tested in a given field of operations. Because of their low ground pressure, ACVs can operate over low-cost trails with an efficiency that compares with that of trucks over conventional roads; this renders them especially attractive for transportation networks in the North West Territories.

  11. Air-cushioning in impact problems

    KAUST Repository

    Moore, M. R.

    2013-05-12

    This paper concerns the displacement potential formulation of the post-impact influence of an air-cushioning layer on the 2D impact of a liquid half-space by a rigid body. The liquid and air are both ideal and incompressible and attention is focussed on cases when the density ratio between the air and liquid is small. In particular, the correction to classical Wagner theory is analysed in detail for the impact of circular cylinders and wedges. © The Authors 2013. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved.

  12. 21 CFR 872.3540 - OTC denture cushion or pad.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3540 OTC denture cushion or pad. (a...-counter. (b) Classification. (1) Class I if the device is made of wax-impregnated cotton cloth that the... denture cushion or pad is made of a material other than wax-impregnated cotton cloth or if the...

  13. Nonlinear Response of Strong Nonlinear System Arisen in Polymer Cushion

    Directory of Open Access Journals (Sweden)

    Jun Wang

    2013-01-01

    Full Text Available A dynamic model is proposed for a polymer foam-based nonlinear cushioning system. An accurate analytical solution for the nonlinear free vibration of the system is derived by applying He's variational iteration method, and conditions for resonance are obtained, which should be avoided in the cushioning design.

  14. Geometrical properties of a discontinuity network in gneissic rock, a case study in high alpine terrain

    Science.gov (United States)

    Koppensteiner, Matthias; Zangerl, Christian

    2017-04-01

    For the purposes of estimating slope stability and investigating landslide formation processes, it is indispensable to obtain information about the discontinuity properties of the rock mass. These properties control failure processes, deformation behaviour and groundwater flow. Scanline measurements represent a systematic surveying method, however they make certain demands in case of natural outcorps in a high alpine terrain. The performance of the scanline method is tested and the thereby obtained and evaluated data is compared to findings from other studies. An area of a well exposed, fractured rock mass composed of granodioritic gneisses in the Oetztal-Stubai crytalline basement of the Alps (Austria) has been chosen to perform the investigations. Eight scanlines have been measured on a single hillside with varying lengths between 8 and 30 meters. The orientations of the scanlines have been varied in order to minimize the sampling bias associated with the angle between the scanlines and the intersected discontinuities. For every intersecting discontinuity at a certain tape length, the orientation, the trace length and the terminations of the trace have been recorded. Primarily, the discontinuity data from all scanlines have been analyzed with the software package Dips (Rocscience, 1989) in order to determine their allocation in sets. For the evaluation of the spacing and trace length properties, two scripts have been developed in the language Matlab (The MathWorks, 1984) to faciliate setwise processing of the entire dataset. Variation of the scanline directions and lengths returned homogeneous sample sizes for the individual discontinuity sets. Both, normal spacings and trace lengths show negative exponential distributions for all sets. A comparison of four different methods to estimate trace lengths show that the result is highly dependent on the chosen method itself. However, when the relation of the results for the respective sets within one of the methods is

  15. Crossing historical and sedimentary archives to reconstruct an extreme flood event calendar in high alpine areas

    Science.gov (United States)

    Wilhelm, B.; Giguet-Covex, C.; Arnaud, F.; Allignol, F.; Legaz, A.; Melo, A.

    2010-09-01

    Torrential flood hazard is expected to increase in the context of global warming. However, long time-series of climate and gauge data at high-elevation sites are too sparse to assess reliably recurrence times of such events in high mountain areas. Historical documents are an alternative which provide valuable information. However, historic archives are by nature subjective and variable in quality owing to hazard perception and vulnerability according to the banks land-use throughout time. To overcome these limits, natural archives may be used as complementary records. Among the various natural archives lake sediments have the advantage to be continuous records in which particular events are preserved such as earthquakes and especially flood events. Furthermore an objective magnitude of these events can be assessed from the thickness of noteworthy event-triggered deposits. However if the recognition of major event-triggered deposits can be simple, a high-resolution dating of these events is more difficult over the historical period due to a lack of chronological markers. In this paper, we present a sediment record study of a French high alpine lake where an important effort was undertaken to date precisely 56 flood events over the last three centuries from the use of historical archives. The caesium and the lead were measured to detect the fallouts of the Chernobyl accident (1986), the atmospheric nuclear weapons tests (1955-1963) and the use of leaded gasoline which culminated in the 70's. In parallel local and regional historical archives were going through in order to correlate the thickest sediment deposits triggered by major floods and earthquakes with their potential triggering historic events. Thus we were able to associate 12 historic flood and 4 earthquake dates to particular sediment deposits. The resulting flood calendar is very well-constrained thanks to 19 chronological marks over the last 270 years, i.e. one mark by 14 years. This method permitted so

  16. Residual settlement calculation of geocell cushion over gravel piles

    Institute of Scientific and Technical Information of China (English)

    陈昌富; 杨宇; 肖淑君; 周志军

    2008-01-01

    The calculation of residual settlement of bidirectional reinforced composite foundation, which is composed of geocell cushion over gravel piles, was studied. The geocell cushion was modeled as a thin flexible plate with large deflection. Based on the Kirchhoff hypothesis, the governing differential equations and boundary conditions of the deformation of geocell cushion under working load were founded using von Karman method and solved by Galerkin method. On theses bases, the gravel piles and inter-pile soils were assumed as Winkler ground with variable spring stiffness so as to execute the approximate calculation of the residual settlement of the bidirectional reinforced composite foundation. The calculation method was verified by two laboratory experiments concerning settlement of embankments. One experiment was with just geocell cushion installed to treat the soft clay under embankments; another one was with both geocell cushion and gravel piles installed. The results show that the calculated settlement curve and the maximum settlement are closed to the observed ones.

  17. Anti-rebound Cushion Device for Hydraulic Breaker

    Institute of Scientific and Technical Information of China (English)

    Zhao Hongqiang

    2005-01-01

    This paper analyzes the phenomenon of rebound impact and its negative influence on the present hydraulic breaker. To get over its shortcomings, a new anti-rebound cushion device has been designed to prevent the phenomenon of rebound impact. A hydraulic cushion is used to absorb the rebound impact energy, which can be released for the next stroke of the hydraulic breaker. Thus, there is little loss of energy, and the efficiency of the impact system can be increased by 5 %. The absorption effect of the hydraulic anti-rebound cushion increases the service life of breaker components by up to twice as long as in the current breaker. A dynamic model and a motion equation of the anti-rebound cushion device are presented, and the optimum frequency and damping ratio are obtained, providing optimum design parameters for the anti-rebound cushion device.

  18. Comparative biomechanical evaluation of different wheelchair seat cushions.

    Science.gov (United States)

    Ferrarin, M; Andreoni, G; Pedotti, A

    2000-01-01

    The aim of the present study was to perform a comparative biomechanical analysis of four antidecubitus wheelchair cushions. Thirty wheelchair users were considered divided into three groups: paraplegic subjects (with no cutaneous sensation), neurologic subjects (with intact cutaneous sensation), and elderly subjects. The biomechanical evaluation was performed using a piezoresistive sensor matrix system to quantify parameters referred to pressure distribution, seating surface and posture. Dedicated software was developed for the automatic elaboration of the raw data and the computation of the parameters of interest. Differences among cushion types and subject groups were analyzed. An analysis of time-transient behaviors was also performed. Results showed that no significant differences in pressure peak reduction were found among the four cushions. Moreover, no time-transient behavior was shown by any cushions. However, both the location of pressure peaks and posture were dependent on cushion types. Comparison of the three subject groups showed that elderly subjects had the highest mean pressure and the lowest contact surface, while paraplegics presented the highest pressure peaks. This procedure appears indicated for individualizing the prescription of a wheelchair cushion and even for customizing a cushion to induce a specific posture.

  19. Ecological implications of reduced pollen supply in the alpine: a case study using a dominant cushion plant species [v2; ref status: indexed, http://f1000r.es/3xc

    Directory of Open Access Journals (Sweden)

    Anya Reid

    2014-08-01

    Full Text Available The reproductive assurance hypothesis states that self-incompatible female plants must produce twice the number of seeds relative to their self-compatible hermaphroditic counterparts to persist in gynodioecious populations. This is a viable life-history strategy, provided that pollination rates are sufficiently high. However, reduced pollination rates in alpine plants are likely due to climate induced plant-pollinator mismatches and general declines in pollinators. Using a gynodioecious population of the dominant plant Silene acaulis (Caryophyllaceae, we tested the reproductive assurance hypothesis and also the stress gradient hypothesis with a series of pollinator exclusion trials and extensive measurements of subsequent reproductive output (gender ratio, plant size, percent fruit-set, fruit weight, seeds per fruit, total seeds, seed weight, and seed germination. The reproductive assurance hypothesis was supported with female plants being more sensitive to and less likely to be viable under reductions in pollination rates. These findings are the first to show that the stress gradient hypothesis is also supported under a gradient of pollen supply instead of environmental limitations. Beneficiary abundance was negatively correlated to percent fruit-set under current pollen supply, but became positive under reduced pollen supply suggesting that there are important plant-plant-pollinator interactions related to reproduction in these alpine plant species.

  20. Proceedings of the 1994 CACTS conference on air cushion technology

    Energy Technology Data Exchange (ETDEWEB)

    Laframboise, J.E. [ed.

    1995-03-01

    The conference held by the Canadian Air Cushion Technology Society (CACTS) was attended by 56 specialists in the field from around the world. CACTS is devoted to the development and application of air cushion technology, primarily in the transportation domain, but also in industry and other fields where the technology may be of benefit. Some uses for the technology include rescue operations in natural disasters such as flooding and oil spill clean up operations in coastal waters. A total of 20 papers were presented at this meeting. Subjects included air cushion spray booms, amphibious transporters in oil spill events, unconventional propulsion systems for air cushion vehicles, ride control systems, and high-speed hovercraft design. Refs., tabs., figs.

  1. Guaianolides and a seco-Eudesmane from the Resinous Exudates of Cushion Bush (Leucophyta brownii) and Evaluation of Their Cytostatic and Anti-inflammatory Activity

    DEFF Research Database (Denmark)

    Hyldgaard, Mette G; Purup, Stig; Bond, Andrew D

    2015-01-01

    A detailed phytochemical investigation of a dichloromethane extract of the resinous exudates of the cushion bush plant (Leucophyta brownii) resulted in the isolation of the new 8,12-guaianolides leucophytalins A (5) and B (6), the new 1,10-seco-eudesmane leucophytalin C (10), six rare 8,12-guaian......A detailed phytochemical investigation of a dichloromethane extract of the resinous exudates of the cushion bush plant (Leucophyta brownii) resulted in the isolation of the new 8,12-guaianolides leucophytalins A (5) and B (6), the new 1,10-seco-eudesmane leucophytalin C (10), six rare 8...

  2. Sonographic appearance of anal cushions of hemorrhoids

    Science.gov (United States)

    Aimaiti, Adilijiang; A Ba Bai Ke Re, Ma Mu Ti Jiang; Ibrahim, Irshat; Chen, Hui; Tuerdi, Maimaitituerxun; Mayinuer

    2017-01-01

    AIM To evaluate the diagnostic value of different sonographic methods in hemorrhoids. METHODS Forty-two healthy volunteers and sixty-two patients with grades I-IV hemorrhoids received two different sonographic examinations from January 2013 to January 2016 at the First and Second Hospitals of Xinjiang Medical University in a prospective way. We analyzed the ultrasonographic findings of these participants and evaluated the outcomes. Resected grades III and IV hemorrhoid tissues were pathologically examined. The concordance of ultrasonographic results with pathology results was assessed with the Cohen’s kappa coefficient. RESULTS All healthy volunteers and all patients had no particular complications related to sonography. There were no statistically significant differences between the participants regarding age (P = 0.5919), gender (P = 0.4183), and persistent symptoms (P > 0.8692). All healthy control participants had no special findings. However, 30 patients with hemorrhoids showed blood signals around the dentate line on ultrasonography. When grades I and II hemorrhoids were analyzed, there were no significant differences between transrectal ultrasound (TRUS), transperianal ultrasound (TPUS), and transvaginal ultrasound (TVUS) (P > 0.05). Grades III and IV hemorrhoids revealed blood flow with different directions which could be observed as a “mosaic pattern”. In patients with grades III and IV hemorrhoids, the number of patients with “mosaic pattern” as revealed by TRUS, TPUS and TVUS was 22, 12, and 4, respectively. Patients with grades III and IV disease presented with a pathologically abnormal cushion which usually appeared as a “mosaic pattern” in TPUS and an arteriovenous fistula in pathology. Subepithelial vessels of resected grades III and IV hemorrhoid tissues were manifested by obvious structural impairment and retrograde and ruptured changes of internal elastic lamina. Some parts of the Trietz’s muscle showed hypertrophy and distortion

  3. Research of Contact Stresses between Seat Cushion and Human Body

    Directory of Open Access Journals (Sweden)

    Pervan Stjepan

    2010-06-01

    Full Text Available Design optimization of seat cushions is associated with the need to investigate their softness using, for this purpose, various kinds of loading pads. The aim of the investigation was: to determine seat cushion stiffness of a chair selected from a set of dining-room furniture, to determine values and distributions of contact strains on the seat surface caused by loading pad of different hardness, numerical calculation of contact strains between the seat cushion and the loading pad and to verify the results of these calculations with the results of laboratory experiments. The performed tests showed that the assessment of the seat cushion stiffness and the evaluation of contact stresses on their surface should be carried out using an equally stiff loading pad. In numerical calculations, polyurethane foams should be modeled as hyperfoam bodies of σ=f(ε characteristics determined in an axial compression test. Contact stresses between the seat cushion and the user’s body should be reduced as a result of application of a frictionless connection of thin layers of polyurethane foams with foam forming the proper elastic layer of the seat.

  4. Contact sensitization to calocephalin, a sesquiterpene lactone of the guaianolide type from cushion bush (Leucophyta brownii, Compositae)

    DEFF Research Database (Denmark)

    Paulsen, Evy; Christensen, Lars P; Hindsén, Monica;

    2013-01-01

    Cushion bush [Leucophyta brownii Cass. = Calocephalus brownii (Cass.) F. Muell.] is an Australian Compositae shrub that has been introduced into Scandinavia as a pot plant. The first case of sensitization occurred in a gardener, and the main allergen was identified as the guaianolide calocephalin....

  5. EXPERIMENTAL AND NUMERICAL INVESTIGATION OF TURBULENT AIR-CUSHION-CASCADE

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Experimental and numerical studies of air-cushion-cascade were conducted and described. The SIMPLE algorithm combined with the normal k-ε turbulence model was adopted to simulate the air-phase flow. The experiment was carried out an IFA 300 anemometer. The flow field was measured for different ratios of main-stream velocity to jet velocity, different numbers of gaps and a couple of gap widths. The contur of the air-cushion was obtained, and the numerical calculations gave a closed-form result. The results show that the air-cushion thickness would increase with the increase of the jet volcoity, gap width and gap number mainly determined by the jet in the former half cascade. The possibility to achieve anti-erosion by the turbulent jet was examined and confirmed.

  6. The Effects of Inflated Seating Cushions on Engagement in Preschool Circle Time

    Science.gov (United States)

    Seifert, Anna M.; Metz, Alexia E.

    2017-01-01

    Inflatable balls and cushions made of non-latex rubber can provide alternatives to sitting on the floor/ground or classroom chairs. This study tested the effect of inflatable cushions (wiggle cushions) placed on the floor for seating during circle time in typical preschool classrooms. The effect on attention was tested using alternating periods of…

  7. A model to assess the comfort of automotive seat cushions.

    Science.gov (United States)

    Jiaxing, Zhan; Fard, Mohammad; Jazar, Reza

    2014-01-01

    A large number of independent and interacting factors affect seating comfort such as seat shape, stability, lumbar support and seat height. Although many subjective comfort studies have been conducted, few of them considered seating comfort from its subassembly level. This paper analyzed the automotive seat cushion designed with geared four-bar linkage for the seat height adjustment. The operation torque and lift distance of this mechanism was investigated as 2 major comfort factors. Ten cushions with this kind of design in the market were compared and assessed.

  8. Developments in skirt systems for air cushion vehicles

    Science.gov (United States)

    Inch, Peter; Prentice, Mark E.; Lewis, Carol Jean

    The present evaluation of the development status of air-cushion vehicle (ACV) skirts emphasizes the materials employed, with a view to the formulation of materials-performance requirements for next-generation AVCs and, in particular, an 'air-cushion catamaran' surface-effect ship (SES). Attention is given to novel skirt-design features which furnish substantial savings in maintenance costs. The employment of extant test rig data and the use of CAD methods are discussed, and the features of a novel system for the direct fixing of a bow finger onto an SES structure are noted.

  9. Optimization of Aircraft Seat Cushion Fire Blocking Layers.

    Science.gov (United States)

    1983-03-01

    A D IA T IO N H I G T E P R T R S B "B IS fLow CONDUCTIVITY \\KYNOLX) 3. INSULATION (LOW DENSITY / S ILICA, PANOX ~CLOSED CELL F--i IBERFAX, NOMEX... CELL /JITCF C+ 73 FT LOCK SEAT CUSHION CONSTRUCTIONS CONF FIRE CUSHION NO BLOCKING FOAM REMARKS WOOL NYLON UPHOLSTERY INONE FR URETHANE (ALL EXCEPT NO 11...34ඣ. 73543. 73737. 73737. DELTA COSTS 6. 6346. 2922. 1150. 1150. 4COStS oft th161.5546 of Sollars . CO COST SUMMA RY REPORT v ON4f3 MrVl An MORtA

  10. Simulation study of plane motion of air cushion vehicle

    Institute of Scientific and Technical Information of China (English)

    ZHAO Shu-qin; SHI Xiao-cheng; SHI Yi-long; BIAN Xin-qian

    2003-01-01

    This research is on horizontal plane motion equations of Air Cushion Vehicle (ACV) and its simulation. To investigate this, a lot of simulation study including ACV's voyage and turning performance has been done. It was found that the voyage simulation results were accorded with ACV own characteristic and turning simulation results were accorded with USA ACV's movement characteristic basically.

  11. Simulation study of plane motion of air cushion vehicle

    Science.gov (United States)

    Zhao, Shu-Qin; Shi, Xiao-Cheng; Shi, Yi-Long; Bian, Xin-Qian

    2003-12-01

    This research is on horizontal plane motion equations of Air Cushion Vehicle (ACV) and its simulation. To investigate this, a lot of simulation study including ACV’s voyage and turning performance has been done. It was found that the voyage simulation results were accorded with ACV own characteristic and turning simulation results were accorded with USA ACV’s movement characteristic basically.

  12. A survey of wheelchair use by paraplegic individuals in Japan. Part 1: Characteristics of wheelchair cushions.

    Science.gov (United States)

    Sumiya, T; Kawamura, K; Tokuhiro, A; Takechi, H; Ogata, H

    1997-09-01

    The characteristics of wheelchair cushions used by 218 paraplegic patients who lived independent lives were surveyed to clarify the present state of wheelchair cushioning for pressure sore prevention in Japan. Out of 586 cushions surveyed, 91.0% were ready-made and the rest were custom-made. The outstanding popularity of polyurethane foam ready-made cushions (76.3%) suggested that insufficient consideration was taken in the selection of cushions. Custom-made cushions displayed unique modifications to relieve contact pressure or to stabilize sitting posture, which should be systematically provided for all patients. The variety of cushion types and the frequent dissatisfaction with cushions seen in patients with current pressure sores suggested a strong demand for the effective prescription of cushions. Furthermore, 30% of all cushions had had an excessively prolonged use, indicating insufficient follow-up. A medical system including deliberate prescription and regular follow-up of wheelchair cushions should be established for the effective prevention of pressure sores.

  13. The effect of cushioning insoles on back and lower extremity pain in an industrial setting.

    Science.gov (United States)

    Jefferson, John R

    2013-10-01

    The purpose of this study was to examine the relationship between low back pain and lower extremity pain in a group of factory workers and determine the effect of cushioning insoles on low back pain and lower extremity pain. Data were gathered via questionnaire from 306 employees of an aircraft engine assembly factory. A subset of 40 workers who had reported significant levels of back or lower extremity pain were sampled for four consecutive 12-hour shifts wearing their normal footwear and then a week later for four consecutive shifts wearing cushioning insoles. High levels of low back pain and lower extremity pain were reported by workers on the plant floor, but low back pain was poorly correlated to lower extremity pain (r = 0.371). The effect of insoles on the subset of 40 workers was to lower low back pain by 38%, foot pain by 37%, and knee pain by 38% (p < .001). The reduction in low back pain, however, was not correlated to the reduction in lower extremity pain; workers reporting a decrease in low back pain differed from those reporting less lower extremity pain.

  14. Observations of fluorescent aerosol-cloud interactions in the free troposphere at the Sphinx high Alpine research station, Jungfraujoch

    Science.gov (United States)

    Crawford, I.; Lloyd, G.; Bower, K. N.; Connolly, P. J.; Flynn, M. J.; Kaye, P. H.; Choularton, T. W.; Gallagher, M. W.

    2015-09-01

    The fluorescent nature of aerosol at a high Alpine site was studied using a wide-band integrated bioaerosol (WIBS-4) single particle multi-channel ultra violet-light induced fluorescence (UV-LIF) spectrometer. This was supported by comprehensive cloud microphysics and meteorological measurements with the aims of cataloguing concentrations of bio-fluorescent aerosols at this high altitude site and also investigating possible influences of UV-fluorescent particle types on cloud-aerosol processes. Analysis of background free tropospheric air masses, using a total aerosol inlet, showed there to be a minor but statistically insignificant increase in the fluorescent aerosol fraction during in-cloud cases compared to out of cloud cases. The size dependence of the fluorescent aerosol fraction showed the larger aerosol to be more likely to be fluorescent with 80 % of 10 μm particles being fluorescent. Whilst the fluorescent particles were in the minority (NFl/NAll = 0.27±0.19), a new hierarchical agglomerative cluster analysis approach, Crawford et al. (2015) revealed the majority of the fluorescent aerosol were likely to be representative of fluorescent mineral dust. A minor episodic contribution from a cluster likely to be representative of primary biological aerosol particles (PBAP) was also observed with a wintertime baseline concentration of 0.1±0.4 L-1. Given the low concentration of this cluster and the typically low ice active fraction of studied PBAP (e.g. pseudomonas syringae) we suggest that the contribution to the observed ice crystal concentration at this location is not significant during the wintertime.

  15. Aerosol size distributions measured in urban, rural and high-alpine air with an electrical low pressure impactor (ELPI)

    Science.gov (United States)

    Held, A.; Zerrath, A.; McKeon, U.; Fehrenbach, T.; Niessner, R.; Plass-Dülmer, C.; Kaminski, U.; Berresheim, H.; Pöschl, U.

    An electrical low pressure impactor (ELPI) was used to study atmospheric aerosol particle number, surface, and mass concentrations and size distributions over a diameter range of 7 nm-10 μm at urban, rural and high-alpine locations along an alpine altitude transect across Southern Germany. The measurements were performed in the city of Munich and at the global atmosphere watch (GAW) stations Hohenpeißenberg and Zugspitze in the years 2001-2004. To minimize particle bounce effects and enable chemical analysis of the collected particles without disturbance by grease on the impaction substrates, the sample flow was conditioned to about 75% relative humidity. The performance of the ELPI instrument was evaluated by comparison with well-established aerosol measurement techniques including condensation particle counters, scanning and differential mobility particle sizers, filter sampling, and gravimetric determination of particulate mass. In general, particle number concentrations, size distributions, and PM2.5 concentrations determined with the ELPI were in good agreement with alternative techniques (rank correlation coefficients ρ = 0.70-0.95). The ELPI filter stage data for the particle diameter range of 7-30 nm, however, appeared to be strongly biased towards high values. Long-term measurements at the rural site (Hohenpeißenberg) revealed distinct seasonal patterns with the highest number concentrations in summer (median daily average: 3100 cm -3) and the highest mass concentrations in spring and fall (median daily average PM2.5 and PM10: 21-25 and 27-35 μg m -3, respectively). In spring and fall we also observed pronounced maxima of particle surface and mass concentration in the coarse mode (peak at ˜3 μm), which are most likely due to primary biological material. Relatively clean air (PM10 urban air from Munich (NE) clearly contributed to elevated particle mass loadings (PM10 > = 10 μg m -3).

  16. Chemical composition of free tropospheric aerosol for PM1 and coarse mode at the high alpine site Jungfraujoch

    Directory of Open Access Journals (Sweden)

    J. Cozic

    2008-01-01

    Full Text Available The chemical composition of submicron (fine mode and supermicron (coarse mode aerosol particles has been investigated at the Jungfraujoch high alpine research station (3580 m a.s.l., Switzerland as part of the GAW aerosol monitoring program since 1999. A clear seasonality was observed for all major components throughout the period with low concentrations in winter (predominantly free tropospheric aerosol and higher concentrations in summer (enhanced vertical transport of boundary layer pollutants. In addition, mass closure was attempted during intensive campaigns in March 2004, February–March 2005 and August 2005. Ionic, carbonaceous and non-refractory components of the aerosol were quantified as well as the PM1 and coarse mode total aerosol mass concentrations. A relatively low conversion factor of 1.8 for organic carbon (OC to particulate organic matter (OM was found in winter (February–March 2005. Organics, sulfate, ammonium, and nitrate were the major components of the fine aerosol fraction that were identified, while calcium and nitrate were the only two measured components contributing to the coarse mode. The aerosol mass concentrations for fine and coarse mode aerosol measured during the intensive campaigns were not typical of the long-term seasonality due largely to dynamical differences. Average fine and coarse mode concentrations during the intensive field campaigns were 1.7 μg m−3 and 2.4 μg m−3 in winter and 2.5 μg m−3 and 2.0 μg m−3 in summer, respectively. The mass balance of aerosols showed higher contributions of calcium and nitrate in the coarse mode during Saharan dust events (SDE than without SDE.

  17. Chemical composition of free tropospheric aerosol for PM1 and coarse mode at the high alpine site Jungfraujoch

    Directory of Open Access Journals (Sweden)

    J. Cozic

    2007-08-01

    Full Text Available The chemical composition of submicron (fine mode and supermicron (coarse mode aerosol particles has been investigated since 1999 within the GAW aerosol monitoring program at the high alpine research station Jungfraujoch (3580 m a.s.l., Switzerland. Clear seasonality was observed for all major components in the last 9 years with low concentrations in winter (predominantly free tropospheric aerosol and higher concentrations in summer (enhanced vertical transport of boundary layer pollutants. In addition, mass closure was attempted during intensive experiments in March 2004, February–March 2005 and August 2005. Ionic, carbonaceous and refractory components of the aerosol were quantified as well as the PM1 and coarse mode total aerosol mass concentrations. A relatively low conversion factor of 1.8 for organic carbon (OC to particulate organic matter (OM in winter (February–March 2005 was found. Organics, sulfate, ammonium, and nitrate were the major identified components of the fine aerosol fraction, while calcium and nitrate were the two major measured components in the coarse mode. The aerosol mass concentrations for fine and coarse mode aerosol during the intensive campaigns were not typical of the long term seasonality due largely to dynamical differences. Average fine and coarse mode concentrations during the intensive field campaigns were 1.7 μg m−3 and 2.4 μg m−3 in winter and 2.5 μg m−3 and 2.0 μg m−3 in summer, respectively. The mass balance of aerosols showed higher contributions of calcium and nitrate in the coarse mode during Saharan dust events (SDE than without SDE.

  18. Gas cushion control of OVJP print head position

    Energy Technology Data Exchange (ETDEWEB)

    Forrest, Stephen R

    2014-10-07

    An OVJP apparatus and method for applying organic vapor or other flowable material to a substrate using a printing head mechanism in which the print head spacing from the substrate is controllable using a cushion of air or other gas applied between the print head and substrate. The print head is mounted for translational movement towards and away from the substrate and is biased toward the substrate by springs or other means. A gas cushion feed assembly supplies a gas under pressure between the print head and substrate which opposes the biasing of the print head toward the substrate so as to form a space between the print head and substrate. By controlling the pressure of gas supplied, the print head separation from the substrate can be precisely controlled.

  19. Effect of air conditioning and chair cushion on scrotal temperature.

    Science.gov (United States)

    Song, Gook-Sup; Kim, Wonwoo; Seo, Ju Tae

    2008-08-01

    The hypothesis of this study is that the air conditioning temperature and thickness of the chair cushion affect a man's scrotal, and consequently testicular, temperature. Ten healthy male subjects volunteered for the study (age: 23.4 +/- 2.4 years; height: 173.8 +/- 5.09 cm; weight: 71.6 +/- 9.7 kg; body fat ratio: 18.6 +/- 4.1%). The air conditioning temperature was controlled at 18 degrees C to represent the heating season, and at 26 degrees C to represent the cooling season. The thickness of the chair cushions was varied from 0 to 8 cm at 2 cm intervals. The changes in the scrotal surface temperature (SST) and buttock skin temperature were measured for 120 min. At the ambient temperatures (t(a)) of 18 and 26 degrees C, the average SST were 33.76 +/- 1.28 and 35.02 +/- 0.54 degrees C for the chair cushion thickness (C(thk)) of 0 cm, 33.87 +/- 1.07 and 34.96 +/- 0.75 degrees C for C(thk) 2 cm, 33.91 +/- 0.84 and 35.03 +/- 0.85 degrees C for C(thk) 4 cm, 34.42 +/- 0.89 and 35.02 +/- 0.63 degrees C for C(thk) 6 cm, and 34.65 +/- 1.21 and 34.99 +/- 0.62 degrees C for C(thk) 8 cm respectively. SST was significantly affected by the air conditioning temperature (p < 0.001), but was not statistically correlated with the chair cushion thickness.

  20. SESAME Equations of State for Stress Cushion and Related Materials

    Energy Technology Data Exchange (ETDEWEB)

    Coe, Joshua Damon [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-02-12

    I examine LANL equations of state (EOS) for stress cushion and related materials, namely S5370, SX358, and Sylgard 184. In the the rst two cases, the SESAME library contains entries for both the inert (unreacted) and decomposition products. I compare inert EOS results with ambient property measurements to the extent possible, then I check the compositions used to build the products tables. I plot the predicted Hugoniots alongside the available shock data, then draw some conclusions.

  1. Distribution of VOCs between air and snow at the Jungfraujoch high alpine research station, Switzerland, during CLACE 5 (winter 2006

    Directory of Open Access Journals (Sweden)

    E. Starokozhev

    2009-05-01

    Full Text Available Volatile organic compounds (VOCs were analyzed in air and snow samples at the Jungfraujoch high alpine research station in Switzerland as part of CLACE 5 (CLoud and Aerosol Characterization Experiment during February/March 2006. The fluxes of individual compounds in ambient air were calculated from gas phase concentrations and wind speed. The highest concentrations and flux values were observed for the aromatic hydrocarbons benzene (14.3 μg.m−2 s−1, 1,3,5-trimethylbenzene (5.27 μg.m−2 s−1, toluene (4.40 μg.m−2 −1, and the aliphatic hydrocarbons i-butane (7.87 μg.m−2 s−1, i-pentane (3.61 μg.m−2 s−1 and n-butane (3.23 μg.m−2 s−1. The measured concentrations and fluxes were used to calculate the efficiency of removal of VOCs by snow, which is defined as difference between the initial and final concentration/flux values of compounds before and after wet deposition. The removal efficiency was calculated at −24°C (−13.7°C and ranged from 37% (35% for o-xylene to 93% (63% for i-pentane. The distribution coefficients of VOCs between the air and snow phases were derived from published poly-parameter linear free energy relationship (pp-LFER data, and compared with distribution coefficients obtained from the simultaneous measurements of VOC concentrations in air and snow at Jungfraujoch. The coefficients calculated from pp-LFER exceeded those values measured in the present study, which indicates more efficient snow scavenging of the VOCs investigated than suggested by theoretical predictions.

  2. Bacterial GDGTs in Holocene sediments and catchment soils of a high Alpine lake: application of the MBT/CBT-paleothermometer

    Directory of Open Access Journals (Sweden)

    H. Niemann

    2012-05-01

    Full Text Available A novel proxy for continental mean annual air temperature (MAAT and soil pH, the MBT/CBT-paleothermometer, is based on the temperature (T and pH-dependent distribution of specific bacterial membrane lipids (branched glycerol dialkyl glycerol tetraethers – GDGTs in soil organic matter. Here, we tested the applicability of the MBT/CBT-paleothermometer to sediments from Lake Cadagno, a high Alpine lake in southern Switzerland with a small catchment of 2.4 km2. We analysed the distribution of bacterial GDGTs in catchment soils and in a radiocarbon-dated sediment core from the centre of the lake, covering the past 11 000 yr. The distribution of bacterial GDGTs in the catchment soils is very similar to that in the lake's surface sediments, indicating a common origin of the lipids. Consequently, their transfer from the soils into the sediment record seems undisturbed, probably without any significant alteration of their distribution through in situ production in the lake itself or early diagenesis of branched GDGTs. The MBT/CBT-inferred MAAT estimates from soils and surface sediments are in good agreement with instrumental values for the Lake Cadagno region (~0.5 °C. Moreover, downcore MBT/CBT-derived MAAT estimates match in timing and magnitude other proxy-based T reconstructions from nearby locations for the last two millennia. Major climate anomalies recorded by the MBT/CBT-paleothermometer are, for instance, the Little Ice Age (~14th to 19th century and the Medieval Warm Period (MWP, ~9th to 14th century. Together, our observations indicate the quantitative applicability of the MBT/CBT-paleothermometer to Lake Cadagno sediments. In addition to the MWP, our lacustrine paleo T record indicates Holocene warm phases at about 3, 5, 7 and 11 kyr before present, which agrees in timing with other records from both the Alps and the sub-polar North-East Atlantic Ocean. The good temporal match of the warm periods determined

  3. Comparison of Stream Temperature Modeling Approaches: The Case of a High Alpine Watershed in the Context of Climate Change

    Science.gov (United States)

    Gallice, A.

    2015-12-01

    Stream temperature controls important aspects of the riverine habitat, such as the rate of spawning or death of many fish species, or the concentration of numerous dissolved substances. In the current context of accelerating climate change, the future evolution of stream temperature is regarded as uncertain, particularly in the Alps. This uncertainty fostered the development of many prediction models, which are usually classified in two categories: mechanistic models and statistical models. Based on the numerical resolution of physical conservation laws, mechanistic models are generally considered to provide more reliable long-term estimates than regression models. However, despite their physical basis, these models are observed to differ quite significantly in some aspects of their implementation, notably (1) the routing of water in the river channel and (2) the estimation of the temperature of groundwater discharging into the stream. For each one of these two aspects, we considered several of the standard modeling approaches reported in the literature and implemented them in a new modular framework. The latter is based on the spatially-distributed snow model Alpine3D, which is essentially used in the framework to compute the amount of water infiltrating in the upper soil layer. Starting from there, different methods can be selected for the computation of the water and energy fluxes in the hillslopes and in the river network. We relied on this framework to compare the various methodologies for river channel routing and groundwater temperature modeling. We notably assessed the impact of each these approaches on the long-term stream temperature predictions of the model under a typical climate change scenario. The case study was conducted over a high Alpine catchment in Switzerland, whose hydrological and thermal regimes are expected to be markedly affected by climate change. The results show that the various modeling approaches lead to significant differences in the

  4. Hygroscopicity of the submicrometer aerosol at the high-alpine site Jungfraujoch, 3580 m a.s.l., Switzerland

    Directory of Open Access Journals (Sweden)

    S. Sjogren

    2008-09-01

    Full Text Available Data from measurements of hygroscopic growth of submicrometer aerosol with a hygroscopicity tandem differential mobility analyzer (HTDMA during four campaigns at the high alpine research station Jungfraujoch, Switzerland, are presented. The campaigns took place during the years 2000, 2002, 2004 and 2005, each lasting approximately one month. Hygroscopic growth factors (GF, i.e. the relative change in particle diameter from dry diameter, D0, to diameter measured at higher relative humidity, RH are presented for three distinct air mass types, namely for: 1 free tropospheric winter conditions, 2 planetary boundary layer influenced air masses (during a summer period and 3 Saharan dust events (SDE. The GF values at 85% RH (D0=100 nm were 1.40±0.11 and 1.29±0.08 for the first two situations while for SDE a bimodal GF distribution was often found. No phase changes were observed when the RH was varied between 10–90%, and the continuous water uptake could be well described with a single-parameter empirical model. The frequency distributions of the average hygroscopic growth factors and the width of the retrieved growth factor distributions (indicating whether the aerosol is internally or externally mixed are presented, which can be used for modeling purposes.

    Measurements of size resolved chemical composition were performed with an aerosol mass spectrometer in parallel to the GF measurements. This made it possible to estimate the apparent ensemble mean GF of the organics (GForg using inverse ZSR (Zdanovskii-Stokes-Robinson modeling. GForg was found to be ~1.20 at aw=0.85, which is at the upper end of previous laboratory and field data though still in agreement with the highly aged and oxidized nature of the Jungfraujoch aerosol.

  5. Air cushion furnace technology for heat treatment of high quality aluminum alloy auto body sheet

    Institute of Scientific and Technical Information of China (English)

    Li Yong; Wang Zhaodong; Ma Mingtu; Wang Guodong; Fu Tianliang; Li Jiadong; Liang Xiong

    2014-01-01

    The process characteristics of heat treatment of aluminum alloy auto body sheet and the working prin-ciple of air cushion furnace were introduced. The process position and irreplaceable role of air cushion furnace in the aluminum alloy auto body sheet production was pointed out after the difficulty and key points in the whole production process of auto body sheet were studied. Then the development process of air cushion furnace line of aluminum alloy sheet was reviewed,summarized and divided to two stages. Based on the research of air cushion furnace,the key technology of it was analyzed,then the key points on process,equipment and control models of air cushion furnace for aluminum alloy auto body sheet in future were put forward. With the rapid de-velopment of automotive industry,there will be certainly a new upsurge of research and application of air cush-ion furnace for heat treatment of aluminum alloy auto body sheet.

  6. The structure of the cushions in the feet of African elephants (Loxodonta africana).

    Science.gov (United States)

    Weissengruber, G E; Egger, G F; Hutchinson, J R; Groenewald, H B; Elsässer, L; Famini, D; Forstenpointner, G

    2006-12-01

    The uniquely designed limbs of the African elephant, Loxodonta africana, support the weight of the largest terrestrial animal. Besides other morphological peculiarities, the feet are equipped with large subcutaneous cushions which play an important role in distributing forces during weight bearing and in storing or absorbing mechanical forces. Although the cushions have been discussed in the literature and captive elephants, in particular, are frequently affected by foot disorders, precise morphological data are sparse. The cushions in the feet of African elephants were examined by means of standard anatomical and histological techniques, computed tomography (CT) and magnetic resonance imaging (MRI). In both the forelimb and the hindlimb a 6th ray, the prepollex or prehallux, is present. These cartilaginous rods support the metacarpal or metatarsal compartment of the cushions. None of the rays touches the ground directly. The cushions consist of sheets or strands of fibrous connective tissue forming larger metacarpal/metatarsal and digital compartments and smaller chambers which were filled with adipose tissue. The compartments are situated between tarsal, metatarsal, metacarpal bones, proximal phalanges or other structures of the locomotor apparatus covering the bones palmarly/plantarly and the thick sole skin. Within the cushions, collagen, reticulin and elastic fibres are found. In the main parts, vascular supply is good and numerous nerves course within the entire cushion. Vater-Pacinian corpuscles are embedded within the collagenous tissue of the cushions and within the dermis. Meissner corpuscles are found in the dermal papillae of the foot skin. The micromorphology of elephant feet cushions resembles that of digital cushions in cattle or of the foot pads in humans but not that of digital cushions in horses. Besides their important mechanical properties, foot cushions in elephants seem to be very sensitive structures.

  7. Short communication: Genetic characterization of digital cushion thickness.

    Science.gov (United States)

    Oikonomou, G; Banos, G; Machado, V; Caixeta, L; Bicalho, R C

    2014-01-01

    Dairy cow lameness is a serious animal welfare issue. It is also a significant cause of economic losses, reducing reproductive efficiency and milk production and increasing culling rates. The digital cushion is a complex structure composed mostly of adipose tissue located underneath the distal phalanx and has recently been phenotypically associated with incidence of claw horn disruption lesions (CHDL); namely, sole ulcers and white line disease. The objective of this study was to characterize digital cushion thickness genetically and to investigate its association with body condition score (BCS), locomotion score (LOCO), CHDL, and milk production. Data were collected from 1 large closely monitored commercial dairy farm located in upstate New York; 923 dairy cows were used. Before trimming, the following data were collected by a member of the research team: BCS, cow height measurement, and LOCO. Presence or not of CHDL (sole ulcer or white line disease, or both) was recorded at trimming. Immediately after the cows were hoof trimmed, they underwent digital sonographic B-mode examination for the measurement of digital cushion thickness. Factors such as parity number, stage of lactation, calving date, mature-equivalent 305-d milk yield (ME305MY), and pedigree information were obtained from the farm's dairy management software (DairyCOMP 305; Valley Agricultural Software, Tulare, CA). Univariate animal models were used to obtain variance component estimations for each studied trait (CHDL, BCS, digital cushion thickness average, LOCO, height, and ME305MY) and a 6-variate analysis was conducted to estimate the genetic, residual, and phenotypic correlations between the studied traits. The heritability estimate of DCTA was 0.33±0.09, whereas a statistically significant genetic correlation was estimated between DCTA and CHDL (-0.60±0.29). Of the other genetic correlations, significant estimates were derived for BCS with LOCO (-0.49±0.19) and ME305MY (-0.48±0.20). Digital

  8. Estimation of background CO2 concentrations at the high alpine station Schneefernerhaus by atmospheric observations and inverse modelling

    Science.gov (United States)

    Giemsa, Esther; Jacobeit, Jucundus; Ries, Ludwig; Frank, Gabriele; Hachinger, Stephan; Meyer-Arnek, Julian

    2016-04-01

    In order to estimate the influence of Central European CO2 emissions, a new method to retrieve background concentrations based on statistics of radon-222 and backward trajectories is developed and applied to the CO2 observations at the alpine high-altitude research station Schneefernerhaus (2670 m a.s.l.). The reliable identification of baseline conditions is important for perceiving changes in time as well as in the sources and sinks of greenhouse gases and thereby assessing the efficiency of existing mitigation strategies. In the particular case of Central Europe, the analysis of background concentrations could add further insights on the question why background CO2 concentrations increased in the last few decades, despite a significant decrease in the reported emissions. Ongoing effort to define the baseline conditions has led to a variety of data selection techniques. In this diversity of data filtering concepts, a relatively recent data selection method effectively appropriates observations of radon-222 to reliably and unambiguously identify baseline air masses. Owing to its relatively constant emission rate from the ice-free land surface and its half-life of 3.8 days that is solely achieved through radioactive decay, the tropospheric background concentration of the inert radioactive gas is low and temporal variations caused by changes in atmospheric transport are precisely detectable. For defining the baseline air masses reaching the high alpine research station Schneefernerhaus, an objective analysis approach is applied to the two-hourly radon records. The CO2 values of days by the radon method associated with prevailing atmospheric background conditions result in the CO2 concentrations representing the least land influenced air masses. Additionally, three-dimensional back-trajectories were retrieved using the Lagrangian Particle Dispersion Model (LPDM) FLEXPART driven by analysis fields of the Global Forecast System (GFS) produced by the National Centers

  9. The Aiguille du Midi (Mont Blanc massif): a unique high-Alpine site to study bedrock permafrost

    Science.gov (United States)

    Deline, P.; Coviello, V.; Cremonese, E.; Gruber, S.; Krautblatter, M.; Malet, S. Jaillet (1), E.; Morra di Cella, U.; Noetzli, J.; Pogliotti, P.; Verleysdonk, S.

    2009-04-01

    Permafrost and its change in steep high-Alpine rock walls remain insufficiently understood because of the difficulties of in situ measurements. A large proportion of permafrost studies is mainly based on modelling, with a few existing instrumented sites and a resulting lack of process understanding. Yet, a number of rockfalls that occurred in the last decade in the Alps are likely related to climatically-driven permafrost degradation, as indicated by ice in starting zones, increased air temperature, and modelling studies. Starting off in the framework of the French-Italian PERMAdataROC project and presently under development within the EU co-funded project PermaNET (Permafrost long-term monitoring network: www.permanet-alpinespace.eu), our investigations at the Aiguille du Midi begin in 2005. The summit (3842 m a.s.l) is accessible from Chamonix by a cable car which was built at the end of the 1950s. Half a million tourists visit the site each year. Because of its elevation, geometry, and year-round accessibility to rock slopes of diverse aspects and to galleries, the site was chosen for: - Monitoring of the thermal regime in steep rock walls. Thermistors were installed at depths of 2, 10, 30 and 55 cm, at all aspects and with slope angles in the range 60-90° (determining e.g. the presence and influence of snow). - Measurements of high altitude climatic data (air temperature and humidity, incoming and outgoing solar radiation, wind speed and direction) perpendicular to the rockwall surface, by movable automatic weather stations. Together with the rock temperature measurements, these data (see Morra et al., poster in session CR4.1) can be used for physically-based model validation (see Pogliotti et al., oral presentation in session CR4.1) or statistical models construction of rock temperature distribution and variability in the rock walls. - Making a 3D-high-resolution DEM by long-range (rock walls) and short-range (galleries) terrestrial laser scanning

  10. Beds, mattresses and cushions for pressure sore prevention and treatment.

    Science.gov (United States)

    Cullum, N; Deeks, J; Sheldon, T A; Song, F; Fletcher, A W

    2000-01-01

    To assess the effectiveness of pressure relieving beds, mattresses and cushions (support surfaces) in the prevention and treatment of pressure sores. Searches of 19 databases, hand searching of journals, conference proceedings, and bibliographies. Randomised controlled trials evaluating support surfaces for the prevention or treatment of pressure sores. There was no restriction on articles based on language or publication status. Data extraction and assessment of study quality was undertaken by two reviewers independently. Trials with similar patients, comparisons, and outcomes were pooled. Where pooling was inappropriate, trials are discussed in a narrative review. 29 RCTs of support surfaces for pressure sore prevention were identified. Some high specification foam mattresses were more effective than 'standard' hospital foam mattresses in moderate-high risk patients. Pressure relieving mattresses in the operating theatre reduced the incidence of pressure sores post-operatively. The relative merits of alternating and constant low pressure, and of the different alternating pressure devices are unclear. Seat cushions and simple, constant low-pressure devices have not been adequately evaluated. Limited evidence suggests that low air loss beds reduce the incidence of pressure sores in intensive care. 6 RCTs of support surfaces for pressure sore treatment were identified. There is good evidence that air-fluidised and low air loss beds improve healing rates. Seat cushions have not been adequately evaluated. 2 RCTs evaluated surfaces for both prevention and treatment in the same trial. PREVENTION - There is good evidence of the effectiveness of high specification foam over standard hospital foam, and pressure relief in the operating theatre. Treatment - There is good evidence of the effectiveness of air-fluidised and low air loss devices as treatments. Overall, however, it is impossible to determine the most effective surface for either prevention or treatment.

  11. Thirty years of research and development of air cushion vehicles

    Science.gov (United States)

    Bertelsen, William R.

    This paper describes the conception of the air cushion vehicle (ACV) from experiments with the ground effect of a VTOL aircraft model. Then it describes the evolution of the ultimate ACV drive system through building and testing many models and 16 full-scale ACV to arrive at complete controllability. Adequate control of the frictionless craft, which are without inherent yaw stability, requires control force of the order of magnitude of propulsion. The derived gimbal fans provide such control force in the form of direct thrust, which is instantly available in any of 360 degrees, meterable, instantly cancelable, and reversible.

  12. Creating new cities through the large air-cushion vehicle.

    Science.gov (United States)

    Anderson, J. L.; Finnegan, P. M.

    1972-01-01

    The air-cushion vehicle (ACV) can travel over concrete roads, grass, sand, mud, swamp, snow, ice, and water. This mobility makes possible a totally new geographical freedom in choosing transportation routes, locating ports, and laying out a city. By the 1980s fleets of large ACV freighters could begin carrying ocean-going cargo. The mobility of an ACV fleet would allow placing hoverports away from areas now crowded. New cities could rise along shallow or reef-bound seacoasts and rivers, just as cities once rose around deep-water seaports.

  13. Northwest passage: Trade route for large air cushion vehicles

    Science.gov (United States)

    Anderson, J. L.

    1973-01-01

    A conceptual vehicle and powerplant (10,000-ton) nuclear-powered air-cushion vehicle (ACV) that could open the Northwest Passage and other Arctic passages to commercial traffic is identified. The report contains a description of the conceptual vehicle, including the powerplant and operations, an assessment of technical feasibility, estimates of capital and operating costs, and identification of eligible cargo and markets. A comparison of the nuclear ACV freighter with nuclear container ships shows that for containerized or roll-on/roll-off cargo the ACV would provide greatly reduced transit time between North Atlantic and North Pacific ports at a competitive cost.

  14. Dynamic stiffness and transmissibility of commercially available wheelchair cushions using a laboratory test method

    Directory of Open Access Journals (Sweden)

    Yasmin Garcia-Mendez, BS

    2012-02-01

    Full Text Available Evidence suggests that wheelchair (WC users are exposed to unhealthy levels of vibration during WC use. Health risks associated with vibration exposure include vertebral disc degeneration and back pain, which may consequently decrease the function and independence of WC users. Some evidence suggests that the cushions used in WCs may amplify vibrations, although conclusive evidence has not been presented in the literature. This study evaluated and compared the transmissibility of commercially available WC cushions with two laboratory test methods: (1 direct measurement of transmissibility while human subjects propelled a WC over a road course with different cushions and (2 characterization of cushions with a material testing system (MTS combined with mathematical models of the apparent mass of the human body. Results showed that although dynamic characterization of WC cushions is possible with an MTS, the results did not correlate well with the transmissibility obtained in the WC road course. Significant differences were found for transmissibility among the cushions tested, with the air-based cushions having lower transmissibility than the foam- or gel-based cushions.

  15. Simulation research on carbon dioxide as cushion gas in gas underground reservoirs

    Institute of Scientific and Technical Information of China (English)

    TAN Yu-fei; LIN Tao

    2009-01-01

    Aimed at the problem of mixing working gas and cushion gas in carbon sequestration technology, the feasibility of using cation dioxide as the cushion gas in reservoirs is discussed firstly. At the usual condition of reservoirs, carbon dioxide is a kind of supercritieal fluid with high condensability, high viscosity and high density. Secondly, this article studies the laws of formation and development of mixing zone by numerical simulation and analyses the impact on mixing zone brought by different injection modes and rational ratios of cushion gas in reservoirs. It is proposed that the appropriate injection ratio of cushion gas is 20% - 30%. Using carbon dioxide as cushion gas in gas reservoirs is able to make the running of natural gas reservoirs economical and efficient.

  16. Dominance hierarchies, diversity and species richness of vascular plants in an alpine meadow: contrasting short and medium term responses to simulated global change

    Directory of Open Access Journals (Sweden)

    Juha M. Alatalo

    2014-05-01

    Full Text Available We studied the impact of simulated global change on a high alpine meadow plant community. Specifically, we examined whether short-term (5 years responses are good predictors for medium-term (7 years changes in the system by applying a factorial warming and nutrient manipulation to 20 plots in Latnjajaure, subarctic Sweden. Seven years of experimental warming and nutrient enhancement caused dramatic shifts in dominance hierarchies in response to the nutrient and the combined warming and nutrient enhancement treatments. Dominance hierarchies in the meadow moved from a community being dominated by cushion plants, deciduous, and evergreen shrubs to a community being dominated by grasses, sedges, and forbs. Short-term responses were shown to be inconsistent in their ability to predict medium-term responses for most functional groups, however, grasses showed a consistent and very substantial increase in response to nutrient addition over the seven years. The non-linear responses over time point out the importance of longer-term studies with repeated measurements to be able to better predict future changes. Forecasted changes to temperature and nutrient availability have implications for trophic interactions, and may ultimately influence the access to and palatability of the forage for grazers. Depending on what anthropogenic change will be most pronounced in the future (increase in nutrient deposits, warming, or a combination of them both, different shifts in community dominance hierarchies may occur. Generally, this study supports the productivity–diversity relationship found across arctic habitats, with community diversity peaking in mid-productivity systems and degrading as nutrient availability increases further. This is likely due the increasing competition in plant–plant interactions and the shifting dominance structure with grasses taking over the experimental plots, suggesting that global change could have high costs to biodiversity in the

  17. Pressure Mapping of a Standard Hospital Recliner and Select Cushions With Healthy Adults: A Comparative Study.

    Science.gov (United States)

    Slayton, Stephanie; Morris, Paula; Brinkley, Jason

    The aim of the study was to compare the degree of pressure created when healthy adult volunteers sat on a hospital recliner chair in various positions and on various cushions. Comparative cross-sectional study. Thirty-four healthy subjects were recruited from the community, an urban city in a rural area of Eastern North Carolina. Interface pressure measurements were taken by the investigators for each subject sitting on a standard hospital recliner under each of the following conditions: no cushion, foam cushion, nonadjustable air cushion, nonadjustable air/foam cushion, and adjustable air cushion. Subject positions, upright sitting and reclined, were randomly selected. Analyses consisted of data visualizations by investigators and univariate statistics. For each surface, mean pressure, peak pressure, and Pressure Area Index (PAI) were obtained and compared. Inferences were drawn from a repeated-measures analysis-of-covariance model. Subject position was not associated with any of the measures for each surface after adjusting for other variables (average pressure P = .1094, maximum/peak pressure P = .1318, PAI P = .4336). Subject weight, the type of surface, and their interaction do impact the results (average pressure, maximum/peak pressure, and PAI, P pressures and the lowest PAI. The nonadjustable air and air/foam cushions performed most similarly to each other, showing lowest mean and average interface pressures and the highest PAI. Position of a hospital recliner chair in the 2 positions studied had no association with interface pressure outcomes; therefore, other methods of pressure redistribution need to be utilized by clinicians. Based on the results of this study, clinicians may need to reevaluate the type of cushion used in the acute hospital setting, as a standard foam cushion was found to increase interface pressures when compared to other cushions and a standard hospital recliner.

  18. Mountain substitutability and peak load pricing of high alpine peaks as a management tool to reduce environmental damage: a contingent valuation study.

    Science.gov (United States)

    Loomis, John B; Keske, Catherine M

    2009-04-01

    High alpine peaks throughout the world are under increasing environmental pressure from hikers, trekkers, and climbers. Colorado's "Fourteeners", peaks with summits above 14,000 feet are no exception. Most of these peaks have no entrance fees, and reach ecological and social carrying capacity on weekends. This paper illustrates how a series of dichotomous choice contingent valuation questions can be used to evaluate substitutability between different alpine peaks and quantify the price responsiveness to an entrance fee. Using this approach, we find that peak load pricing would decrease use of popular Fourteeners in Colorado by 22%. This reduction is due almost entirely to substitution, rather than income effects. There is also price inelastic demand, as 60% of the hikers find no substitution for their specific Fourteener at the varying cost increases posed in the survey. The no substitute group has a mean net benefit of $294 per hiker, per trip, considerably higher than visitor net benefits in most recreational use studies.

  19. Unusual phenolic compounds contribute to ecophysiological performance in the purple-colored green alga zygogonium ericetorum (zygnematophyceae, streptophyta) from a high-alpine habitat.

    Science.gov (United States)

    Aigner, Siegfried; Remias, Daniel; Karsten, Ulf; Holzinger, Andreas

    2013-08-01

    The filamentous green alga Zygogonium ericetorum (Zygnematophyceae, Streptophyta) was collected in a high-alpine rivulet in Tyrol, Austria. Two different morphotypes of this alga were found: a purple morph with a visible purple vacuolar content and a green morph lacking this coloration. These morphotypes were compared with respect to their secondary metabolites, ultrastructure, and ecophysiological properties. Colorimetric tests with aqueous extracts of the purple morph indicated the presence of soluble compounds such as phenolics and hydrolyzable tannins. High-performance liquid chromatography-screening showed that Z. ericetorum contained several large phenolic peaks with absorption maxima at ∼280 nm and sometimes with minor maxima at ∼380 nm. Such compounds are uncommon for freshwater green microalgae, and could contribute to protect the organism against increased UV and visible (VIS) irradiation. The purple Z. ericetorum contained larger amounts (per dry weight) of the putative phenolic substances than the green morph; exposure to irradiation may be a key factor for accumulation of these phenolic compounds. Transmission electron microscopy of the purple morph showed massive vacuolization with homogenous medium electron-dense content in the cell periphery, which possibly contains the secondary compounds. In contrast, the green morph had smaller, electron-translucent vacuoles. The ecophysiological data on photosynthesis and desiccation tolerance indicated that increasing photon fluence densities led to much higher relative electron transport rates (rETR) in the purple than in the green morph. These data suggest that the secondary metabolites in the purple morph are important for light acclimation in high-alpine habitats. However, the green morph recovered better after 4 d of rehydration following desiccation stress.

  20. BMP-2 induces versican and hyaluronan that contribute to post-EMT AV cushion cell migration.

    Science.gov (United States)

    Inai, Kei; Burnside, Jessica L; Hoffman, Stanley; Toole, Bryan P; Sugi, Yukiko

    2013-01-01

    Distal outgrowth and maturation of mesenchymalized endocardial cushions are critical morphogenetic events during post-EMT atrioventricular (AV) valvuloseptal morphogenesis. We explored the role of BMP-2 in the regulation of valvulogenic extracellular matrix (ECM) components, versican and hyaluronan (HA), and cell migration during post-EMT AV cushion distal outgrowth/expansion. We observed intense staining of versican and HA in AV cushion mesenchyme from the early cushion expansion stage, Hamburger and Hamilton (HH) stage-17 to the cushion maturation stage, HH stage-29 in the chick. Based on this expression pattern we examined the role of BMP-2 in regulating versican and HA using 3D AV cushion mesenchymal cell (CMC) aggregate cultures on hydrated collagen gels. BMP-2 induced versican expression and HA deposition as well as mRNA expression of versican and Has2 by CMCs in a dose dependent manner. Noggin, an antagonist of BMP, abolished BMP-2-induced versican and HA as well as mRNA expression of versican and Has2. We further examined whether BMP-2-promoted cell migration was associated with expression of versican and HA. BMP-2- promoted cell migration was significantly impaired by treatments with versican siRNA and HA oligomer. In conclusion, we provide evidence that BMP-2 induces expression of versican and HA by AV CMCs and that these ECM components contribute to BMP-2-induced CMC migration, indicating critical roles for BMP-2 in distal outgrowth/expansion of mesenchymalized AV cushions.

  1. BMP-2 induces versican and hyaluronan that contribute to post-EMT AV cushion cell migration.

    Directory of Open Access Journals (Sweden)

    Kei Inai

    Full Text Available Distal outgrowth and maturation of mesenchymalized endocardial cushions are critical morphogenetic events during post-EMT atrioventricular (AV valvuloseptal morphogenesis. We explored the role of BMP-2 in the regulation of valvulogenic extracellular matrix (ECM components, versican and hyaluronan (HA, and cell migration during post-EMT AV cushion distal outgrowth/expansion. We observed intense staining of versican and HA in AV cushion mesenchyme from the early cushion expansion stage, Hamburger and Hamilton (HH stage-17 to the cushion maturation stage, HH stage-29 in the chick. Based on this expression pattern we examined the role of BMP-2 in regulating versican and HA using 3D AV cushion mesenchymal cell (CMC aggregate cultures on hydrated collagen gels. BMP-2 induced versican expression and HA deposition as well as mRNA expression of versican and Has2 by CMCs in a dose dependent manner. Noggin, an antagonist of BMP, abolished BMP-2-induced versican and HA as well as mRNA expression of versican and Has2. We further examined whether BMP-2-promoted cell migration was associated with expression of versican and HA. BMP-2- promoted cell migration was significantly impaired by treatments with versican siRNA and HA oligomer. In conclusion, we provide evidence that BMP-2 induces expression of versican and HA by AV CMCs and that these ECM components contribute to BMP-2-induced CMC migration, indicating critical roles for BMP-2 in distal outgrowth/expansion of mesenchymalized AV cushions.

  2. A FIRST APPROXIMATION CALCULATION OF AIR CUSHION CHASSIS WEIGHT OF TRANSPORT AIRPLANE

    Directory of Open Access Journals (Sweden)

    2016-01-01

    Full Text Available This article describes a first approximation of a weighted estimate of air cushion chassis. The algorithm for calculating the weight of air cushion chassis allows not only to estimate the mass of the chassis to a first approximation, but also to conduct a preliminary analysis of the influence of various parameters of the aircraft and the chassis on the weight of the aircraft at the stage of before designing. The algorithm can be expanded to include additional design decisions, such as the transformation of the fuselage, increasing the air cushion chassis canopy due to extensions, center of gravity, etc.

  3. Study of distribution and characteristics of the time average of pressure of a water cushion pool

    Science.gov (United States)

    Guo, Y. H.; Fu, J. F.

    2016-08-01

    When a dam discharges flood water, the plunging flow with greater kinetic energy, will scour the riverbed, resulting in erosion damage. In order to improve the anti-erosion capacity of a riverbed, the cushion pool created. This paper is based on turbulent jet theoryto deduce the semi-empirical formula of the time average of pressure in the impinging portion of the cushion pool. Additionally, MATLAB numerical is used to conduct a simulation analysis according to turbulent jet energy and watercushion depth when water floods into the water cushion pool, to determine the regularities of distribution and related characteristics.

  4. Air-cushion tankers for Alaskan North Slope oil

    Science.gov (United States)

    Anderson, J. L.

    1973-01-01

    A concept is described for transporting oil from the Arctic to southern markets in 10,000-ton, chemically fueled air-cushion vehicles (ACV's) configured as tankers. Based on preliminary cost estimates the conceptual ACV tanker system as tailored to the transportation of Alaskan North Slope oil could deliver the oil for about the same price per barrel as the proposed trans-Alaska pipeline with only one-third of the capital investment. The report includes the description of the conceptual system and its operation; preliminary cost estimates; an appraisal of ACV tanker development; and a comparison of system costs, versatility, vulnerability, and ecological effect with those of the trans-Alaska pipeline.

  5. Computer-aided conceptual design of Air Cushion Vehicles

    Science.gov (United States)

    Band, E. G. U.; Lavis, D. R.

    This paper describes the development and use of a computer-aided design tool which has been used to explore preferred options for amphibious Air-Cushion Vehicle (ACV) and Surface-Effect Ship (SES) designs in support of U.S. Navy and U.S. Army programs. The tool, referred to as the ACV Design Synthesis Model (ADSM), is an interactive computer program which provides a description of feasible ACV or SES concepts that could be developed, by a competent design team, to perform the mission described by the input parameters. The paper discusses how the program was used to explore parametrically the design of a range of self-propelled hoverbarges to meet requirements of the U.S. Army Logistics Over the Shore (LOTS) phases of an amphibious landing. Examples of results are presented to illustrate the method used in determining design and performance trade-offs.

  6. Reduced energy and volume air pump for a seat cushion

    Energy Technology Data Exchange (ETDEWEB)

    Vaughn, Mark R. (Albuquerque, NM); Constantineau, Edward J. (Albuquerque, NM); Groves, Gordon E. (Tijeras, NM)

    1997-01-01

    An efficient pump system for transferring air between sets of bladders in a cushion. The pump system utilizes a reversible piston within a cylinder in conjunction with an equalizing valve in the piston which opens when the piston reaches the end of travel in one direction. The weight of a seated user then forces air back across the piston from an inflated bladder to the previously deflated bladder until the pressure is equalized. In this fashion the work done by the pump is cut in half. The inflation and deflation of the different bladders is controlled to vary the pressure on the several pressure points of a seated user. A principal application is for wheel chair use to prevent pressure ulcers.

  7. Reduced energy and volume air pump for a seat cushion

    Energy Technology Data Exchange (ETDEWEB)

    Vaughn, M.R.; Constantineau, E.J.; Groves, G.E.

    1997-08-19

    An efficient pump system is described for transferring air between sets of bladders in a cushion. The pump system utilizes a reversible piston within a cylinder in conjunction with an equalizing valve in the piston which opens when the piston reaches the end of travel in one direction. The weight of a seated user then forces air back across the piston from an inflated bladder to the previously deflated bladder until the pressure is equalized. In this fashion the work done by the pump is cut in half. The inflation and deflation of the different bladders is controlled to vary the pressure on the several pressure points of a seated user. A principal application is for wheel chair use to prevent pressure ulcers. 12 figs.

  8. An audit of cushioned diabetic footwear: relation to patient compliance.

    Science.gov (United States)

    Chantelau, E; Haage, P

    1994-01-01

    The recurrence rate of neuropathic foot ulcers is reported in 51 diabetic patients regularly attending a diabetic foot clinic. All of the patients were provided with protective footwear reducing peak plantar pressure at the forefoot area by 50% (versus normal shoes), and were followed up for up to 4 years. Compliance with this footwear was recorded by assessing the daily time of wearing protective or normal shoes, and compliance with foot care was recorded from the entries in the patients charts. The results of this observational study demonstrate that wearing protective shoes for > 60% of the daytime significantly (p = 0.0002) reduced the ulcer relapse rate by > 50% in comparison with shorter wearing times for these shoes. In addition, patients without ulcer relapses had foot care significantly more frequently than patients with relapse (p < 0.05). It is concluded that cushioned protective footwear in association with frequent foot care is essential in the prevention of neuropathic diabetic foot ulcer recurrence.

  9. Standing steady-state wave-making calculation method for air cushion vehicles; Air cushion vehicle no teijo zoha keisanho ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Eguchi, T. [Mitsui Engineering and Shipbuilding Co. Ltd., Tokyo (Japan)

    1996-04-10

    The pulse-height distribution of a cushion room of air cushion vehicle (ACV) has been tried to be approached by means of the panel shift type Rankine source method. When using this method, it was not required to introduce the pressure distribution model simulating the fall-off effect for the step-formed cushion pressure distribution. The wave form and wave making resistance could be estimated precisely by assigning the pressure gradient to one longitudinal direction panel in the calculation. The waveform shape within the cushion room could be calculated rather precisely by comparing with the analytic solution. This calculation method did have an ability providing the pulse-height information in the cushion room of ACV for seal design and configuration of ships. The analytic solution using for the comparison was sufficient for determining the pulse-height in the high speed region. However, it was hard to respond to non-linear problems or optional shape problems. It was pointed out to be further improved. 5 refs., 8 figs.

  10. a Vibrational Model of Open Celled Polyurethane Foam Automotive Seat Cushions

    Science.gov (United States)

    Patten, W. N.; Sha, S.; Mo, C.

    1998-10-01

    A mechanistic model of a seat cushion is developed. The work relates the kinematic motion of the seat to the geometric and constitutive properties of the cellular foam used in the seat. The model includes the influence of pneumatic damping caused by friction between the gas within the open-celled foam and matrix polymer. A continuous shape function is introduced to characterize the piecewise continuous stress-strain characteristic of flexible open-celled foam. After some simplification, a non-linear dynamic automotive seat cushion model is derived, which relies explicitly on the constitutive properties of polyurethane foams and on the geometry of the seat cushion. Experimental and analytical models of the two automotive seats are compared to verify the model. The comparisons indicate that the new model is able to predict the dynamic performance of an automotive seat cushion with fidelity.

  11. Contrasting nurse plants and nurse rocks: The spatial distribution of seedlings of two sub-Antarctic species

    Science.gov (United States)

    Haussmann, N. S.; McGeoch, M. A.; Boelhouwers, J. C.

    2010-05-01

    Positive plant interactions, such as those associated with nurse plants, have been suggested to dominate over negative interactions in environments with high abiotic stress. Here we demonstrate that the sub-Antarctic cushion plant species, Azorella selago (Apiaceae), positively affects the distribution of both its own seedlings and those of the perennial grass, Agrostis magellanica (Poaceae). As a result of the light weight and small size of seeds of both species, coupled with strong winds experienced in the study area, we consider it unlikely that these patterns are the result of very localized seed dispersal from the study cushions themselves. Instead, we suggest that both cushions and rocks act as seed traps, trapping seeds dispersed by wind, runoff and/or downslope sediment transport through frost creep. In addition, increased A. selago seedling numbers around cushions, but not around rocks, suggest that cushions provide a biological nurse effect, such as improving soil nutrient status or providing mychorrizae, to seedlings of their own kind.

  12. BMP2 expression in the endocardial lineage is required for AV endocardial cushion maturation and remodeling.

    Science.gov (United States)

    Saxon, Jacob G; Baer, Daniel R; Barton, Julie A; Hawkins, Travis; Wu, Bingruo; Trusk, Thomas C; Harris, Stephen E; Zhou, Bin; Mishina, Yuji; Sugi, Yukiko

    2017-10-01

    Distal outgrowth, maturation and remodeling of the endocardial cushion mesenchyme in the atrioventricular (AV) canal are the essential morphogenetic events during four-chambered heart formation. Mesenchymalized AV endocardial cushions give rise to the AV valves and the membranous ventricular septum (VS). Failure of these processes results in several human congenital heart defects. Despite this clinical relevance, the mechanisms governing how mesenchymalized AV endocardial cushions mature and remodel into the membranous VS and AV valves have only begun to be elucidated. The role of BMP signaling in the myocardial and secondary heart forming lineage has been well studied; however, little is known about the role of BMP2 expression in the endocardial lineage. To fill this knowledge gap, we generated Bmp2 endocardial lineage-specific conditional knockouts (referred to as Bmp2 cKO(Endo)) by crossing conditionally-targeted Bmp2(flox/flox) mice with a Cre-driver line, Nfatc1(Cre), wherein Cre-mediated recombination was restricted to the endocardial cells and their mesenchymal progeny. Bmp2 cKO(Endo) mouse embryos did not exhibit failure or delay in the initial AV endocardial cushion formation at embryonic day (ED) 9.5-11.5; however, significant reductions in AV cushion size were detected in Bmp2 cKO(Endo) mouse embryos when compared to control embryos at ED13.5 and ED16.5. Moreover, deletion of Bmp2 from the endocardial lineage consistently resulted in membranous ventricular septal defects (VSDs), and mitral valve deficiencies, as evidenced by the absence of stratification of mitral valves at birth. Muscular VSDs were not found in Bmp2 cKO(Endo) mouse hearts. To understand the underlying morphogenetic mechanisms leading to a decrease in cushion size, cell proliferation and cell death were examined for AV endocardial cushions. Phospho-histone H3 analyses for cell proliferation and TUNEL assays for apoptotic cell death did not reveal significant differences between control

  13. Sensitivity estimations for cloud droplet formation in the vicinity of the high alpine research station Jungfraujoch (3580 m a.s.l.

    Directory of Open Access Journals (Sweden)

    E. Hammer

    2014-10-01

    Full Text Available Aerosol radiative forcing estimates suffer from large uncertainties as a result of insufficient understanding of aerosol–cloud interactions. The main source of these uncertainties are dynamical processes such as turbulence and entrainment but also key aerosol parameters such as aerosol number concentration and size distribution, and to a much lesser extent, the composition. From June to August 2011 a Cloud and Aerosol Characterization Experiment (CLACE was performed at the high-alpine research station Jungfraujoch (Switzerland, 3580 m a.s.l. focusing on the activation of aerosol to form liquid-phase clouds (in the cloud base temperature range of −8 to 5 °C. With a box model the sensitivity of the effective peak supersaturation (SSpeak, an important parameter for cloud activation, to key aerosol and dynamical parameters was investigated. It was found that the updraft velocity, defining the cooling rate of an air parcel, is the parameter with the largest influence on SSpeak. Small-scale variations in the cooling rate with large amplitudes can significantly alter CCN activation. Thus, an accurate knowledge of the air parcel history is required to estimate SSpeak. The results show that the cloud base updraft velocities estimated from the horizontal wind measurements made at the Jungfraujoch can be divided by a factor of approximately 4 to get the updraft velocity required for the model to reproduce the observed SSpeak.

  14. Plume aerodynamic effects of cushion engine in lunar landing

    Institute of Scientific and Technical Information of China (English)

    He Bijiao; He Xiaoying; Zhang Mingxing; Cai Guobiao

    2013-01-01

    During the second period of China “Tanyue” Project,the explorer will softland on the moon.The cushion engines are used to decelerate the explorer and reduce the impact on the lunar ground.It is necessary to study its plume effects on the explorer component.The self-developed PWS (Plume WorkStation) software based on direct simulation Monte Carlo (DSMC) method is used to simulate the plume effects of two 150 N engines.Due to the complex structure of the explorer,PWS uses a decoupling method to treat the boundary mesh,which mainly interacts with simulation particles,and has no relation with the computational grids.After the analytical expressions of plane surfaces and curved surfaces of each boundary block are given,the particle position within or without the boundary blocks can be easily determined.Finally the 3D plume field of two 150 N engines is simulated.The pressure,temperature and velocity distributions of plume field are clearly presented by three characteristic slices.The aerodynamic effects on the explorer bottom,the landfall legs and antenna are separately shown.The compression influence on the plume flow of four landfall legs can be observed.

  15. Method for calculating steady-state waves in an air cushion vehicle. Part 2; Air cushion vehicle no teijo zoha keisanho ni tsuite. 2

    Energy Technology Data Exchange (ETDEWEB)

    Eguchi, T. [Mitsui Engineering and Shipbuilding Co. Ltd., Tokyo (Japan)

    1997-10-01

    Discussions were given on a method to estimate resistance constituents in wave resistance made in an air chamber of an air cushion vehicle (ACV). An orthogonal coordinate system is considered, which uses the center of a hull as the zero point and is made dimensionless by using cushion length. Flow around the ACV is supposed as an ideal flow, whereas speed potential is defined in the flow field. Then, a linear free surface condition is hypothesized on water surface Z = 0. Number and density of waves were used to introduce a condition to be satisfied by the speed potential. A numerical calculation method arranged a blow-out panel on the water surface, and used a panel shift type Rankine source method which satisfies the free surface condition at Z = 0. Cushion pressure distribution becomes a step-like discontinuous function, and mathematical infinity is generated in the differentiation values. Under an assumption that the pressure rises per one panel where pressure jump is present, the distribution was approximated by providing one panel with inclination of the finite quantity therein. Estimation on wave height distribution in the cushion chamber showed a tendency of qualitatively agreeing with the experimental result, but the wave heights shown in the experiment had the average level decreased as it goes toward the rear of the hull. 5 refs., 5 figs.

  16. Endocardial cushion defect associated with cor triatriatum sinistrum or supravalve mitral ring.

    Science.gov (United States)

    Thilenius, O G; Vitullo, D; Bharati, S; Luken, J; Lamberti, J J; Tatooles, C; Lev, M; Carr, I; Arcilla, R A

    1979-12-01

    Clinical and angiographic or autopsy data, or both, on three children with a subdivided left atrium (cor triatriatum) and an associated endocardial cushion defect are reviewed. (One child had ostium primum defect, and two had complete atrioventricular [A-V] canal.) A fourth patient demonstrates the difficulties in differentiating subdivided left atrium from supravalve mitral stenosis in the presence of an endocardial cushion defect. The clinical findings are greatly influenced by the endocardial cushion defect. A pressure gradient between the pulmonary wedge and (left or right) ventricular end-diastolic pressures in patients with an endocardial cushion defect indicates pulmonary venous obstruction and should alert one to the possibility of these combined lesions. The exact diagnosis is made with injections of angiographic contrast medium into the proximal and distal left atrial chambers, to documented the respective relations of the pulmonary veins, left atrial appendage and A-V valves to these atrial chambers. All three patients with an endocardial cushion defect and a subdivided left atrium had an associated patent ductus arteriosus. The common association of subdivided left atrium with intracardiac, pulmonary venous and aortic anomalies is again demonstrated.

  17. Numerical simulation on the seismic absorption effect of the cushion in rigid-pile composite foundation

    Science.gov (United States)

    Han, Xiaolei; Li, Yaokun; Ji, Jing; Ying, Junhao; Li, Weichen; Dai, Baicheng

    2016-06-01

    In order to quantitatively study the seismic absorption effect of the cushion on a superstructure, a numerical simulation and parametric study are carried out on the overall FEA model of a rigid-pile composite foundation in ABAQUS. A simulation of a shaking table test on a rigid mass block is first completed with ABAQUS and EERA, and the effectiveness of the Drucker-Prager constitutive model and the finite-infinite element coupling method is proved. Dynamic time-history analysis of the overall model under frequent and rare earthquakes is carried out using seismic waves from the El Centro, Kobe, and Bonds earthquakes. The different responses of rigid-pile composite foundations and pile-raft foundations are discussed. Furthermore, the influence of thickness and modulus of cushion, and ground acceleration on the seismic absorption effect of the cushion are analyzed. The results show that: 1) the seismic absorption effect of a cushion is good under rare earthquakes, with an absorption ratio of about 0.85; and 2) the seismic absorption effect is strongly affected by cushion thickness and ground acceleration.

  18. Ingredient of Biomass Packaging Material and Compare Study on Cushion Properties

    Directory of Open Access Journals (Sweden)

    Fangyi Li

    2014-01-01

    Full Text Available In order to reduce the white pollution caused by nondegradable waste plastic packaging materials, the biomass cushion packaging material with straw fiber and starch as the main raw materials had been synthesized. The orthogonal experiment was used to study the impact of mass ratio of fiber to starch, content of plasticizer, active agent, and foaming agent on the compressive strength of cushion material. Infrared spectrometer and theory of water’s bridge-connection were used to study the hydroxyl groups among the fiber and starch. The results were demonstrated as follows: the mass ratio of fiber to starch had the most significant impact on compressive strength. When the contents of the plasticizer, the foaming agent, and the active agent were, respectively, 12%, 0.1%, and 0.3% and the mass ratio of fiber to starch was 2 : 5, the compressive strength was the best up to 0.94 MPa. Meanwhile, with the plasticizer content and the mass ratio of fiber to starch increasing, the cushioning coefficient of the material decreased first and then increased. Comparing the cushion and rebound performance of this material with others, the biomass cushion packaging material could be an ideal substitute of plastic packaging materials such as EPS and EPE.

  19. Posture Detection Based on Smart Cushion for Wheelchair Users

    Directory of Open Access Journals (Sweden)

    Congcong Ma

    2017-03-01

    Full Text Available The postures of wheelchair users can reveal their sitting habit, mood, and even predict health risks such as pressure ulcers or lower back pain. Mining the hidden information of the postures can reveal their wellness and general health conditions. In this paper, a cushion-based posture recognition system is used to process pressure sensor signals for the detection of user’s posture in the wheelchair. The proposed posture detection method is composed of three main steps: data level classification for posture detection, backward selection of sensor configuration, and recognition results compared with previous literature. Five supervised classification techniques—Decision Tree (J48, Support Vector Machines (SVM, Multilayer Perceptron (MLP, Naive Bayes, and k-Nearest Neighbor (k-NN—are compared in terms of classification accuracy, precision, recall, and F-measure. Results indicate that the J48 classifier provides the highest accuracy compared to other techniques. The backward selection method was used to determine the best sensor deployment configuration of the wheelchair. Several kinds of pressure sensor deployments are compared and our new method of deployment is shown to better detect postures of the wheelchair users. Performance analysis also took into account the Body Mass Index (BMI, useful for evaluating the robustness of the method across individual physical differences. Results show that our proposed sensor deployment is effective, achieving 99.47% posture recognition accuracy. Our proposed method is very competitive for posture recognition and robust in comparison with other former research. Accurate posture detection represents a fundamental basic block to develop several applications, including fatigue estimation and activity level assessment.

  20. 1997–2007 CO trend at the high Alpine site Jungfraujoch: a comparison between NDIR surface in situ and FTIR remote sensing observations

    Directory of Open Access Journals (Sweden)

    B. Dils

    2011-07-01

    Full Text Available Within the atmospheric research community, there is a strong interest in integrated datasets, combining data from several instrumentations. This integration is complicated by the different characteristics of the datasets, inherent to the measurement techniques. Here we have compared two carbon monoxide time series (1997 till 2007 acquired at the high-Alpine research station Jungfraujoch (3580 m above sea level, with two well-established measurement techniques, namely in situ surface concentration measurements using Non-Dispersive Infrared Absorption technology (NDIR, and ground-based remote sensing measurements using solar absorption Fourier Transform Infrared spectrometry (FTIR. The profile information available in the FTIR signal allowed us to extract an independent layer with a top height of 7.18 km above sea level, appropriate for comparison with our in situ measurements. We show that, even if both techniques are able to measure free troposphere CO concentrations, the datasets exhibit marked differences in their overall trends (−3.21 ± 0.03 ppb year−1 for NDIR vs. −0.8 ± 0.4 ppb year−1 for FTIR. Removing measurements that are polluted by uprising boundary layer air has a strong impact on the NDIR trend (now −2.62 ± 0.03 ppb year−1, but its difference with FTIR remains significant. Using the LAGRANTO trajectory model, we show that both measurement techniques are influenced by different source regions and therefore are likely subject to exhibit significant differences in their overall trend behaviour. However the observation that the NDIR-FTIR trend difference is as significant before as after 2001 is at odds with available emission databases which claim a significant Asian CO increase after 2001 only.

  1. High-resolution dynamical downscaling of reanalysis data and coupling to a distributed hydrological model in high alpine terrain - a case study in the Berchtesgaden Alps

    Science.gov (United States)

    Warscher, Michael; Wagner, Sven; Laux, Patrick; Smiatek, Gerhard; Kunstmann, Harald

    2017-04-01

    High-resolution dynamical downscaling of ERA-Interim reanalysis data is performed for the high alpine region of the Berchtesgaden Alps using the regional climate model (RCM) WRF. The spatial resolutions of the two nested RCM model domains are 15 km and 5 km respectively. The RCM data is subsequently coupled to the distributed hydrological model (HM) WaSiM using several bias correction methods. A gridded observation dataset (REGNIE, German Weather Service - DWD), meteorological data from a dense station network in the region, and runoff gauge data are used to validate the RCM and HM results. The RCM results of both model domains as well as the forcing data are compared to observations on an hourly, daily and monthly basis. The focus is on the variables necessary to force the HM, which are temperature, humidity, precipitation, wind speed and global radiation. The comparisons reveal that the high spatial resolution of 5 km is necessary to reproduce small scale spatial variations in the complex alpine terrain. The RCM simulations show an added value compared to the forcing atmospheric data by improving absolute values and temporal dynamics of the meteorological variables, especially for precipitation. However, it is shown that the spatial resolution is still not sufficient to cover and reproduce all spatial heterogeneities in the catchment, and that there are still biases in the RCM data. Therefore, several statistical bias correction methods are used to correct the RCM data for biases and elevation effects. The HM is subsequently forced using the corrected data, and model results are compared to runoff gauge data. The results show that regional dynamical downscaling in alpine regions has to be performed in very high spatial resolutions in order to reproduce small scale spatial variations and to reduce model biases. Despite these improvements, subsequent bias correction of the RCM data is still necessary to facilitate meaningful hydrological predictions.

  2. Sensitivity estimations for cloud droplet formation in the vicinity of the high-alpine research station Jungfraujoch (3580 m a.s.l.

    Directory of Open Access Journals (Sweden)

    E. Hammer

    2015-09-01

    Full Text Available Aerosol radiative forcing estimates suffer from large uncertainties as a result of insufficient understanding of aerosol–cloud interactions. The main source of these uncertainties is dynamical processes such as turbulence and entrainment but also key aerosol parameters such as aerosol number concentration and size distribution, and to a much lesser extent, the composition. From June to August 2011 a Cloud and Aerosol Characterization Experiment (CLACE2011 was performed at the high-alpine research station Jungfraujoch (Switzerland, 3580 m a.s.l. focusing on the activation of aerosol to form liquid-phase clouds (in the cloud base temperature range of −8 to 5 °C. With a box model the sensitivity of the effective peak supersaturation (SSpeak, an important parameter for cloud activation, to key aerosol and dynamical parameters was investigated. The updraft velocity, which defines the cooling rate of an air parcel, was found to have the greatest influence on SSpeak. Small-scale variations in the cooling rate with large amplitudes can significantly alter CCN activation. Thus, an accurate knowledge of the air parcel history is required to estimate SSpeak. The results show that the cloud base updraft velocities estimated from the horizontal wind measurements made at the Jungfraujoch can be divided by a factor of approximately 4 to get the updraft velocity required for the model to reproduce the observed SSpeak. The aerosol number concentration and hygroscopic properties were found to be less important than the aerosol size in determining SSpeak. Furthermore turbulence is found to have a maximum influence when SSpeak is between approximately 0.2 and 0.4 %. Simulating the small-scale fluctuations with several amplitudes, frequencies and phases, revealed that independently of the amplitude, the effect of the frequency on SSpeak shows a maximum at 0.46 Hz (median over all phases and at higher frequencies, the maximum SSpeak decreases again.

  3. A theoretical study of limit cycle oscillations of plenum air cushions

    Science.gov (United States)

    Hinchey, M. J.; Sullivan, P. A.

    1981-11-01

    Air cushion vehicles (ACV) are prone to the occurrence of dynamic instabilities which frequently appear as stable finite amplitude oscillations. The aim of this work is to ascertain if the non-linearities characteristics of ACV dynamics generate limit cycle oscillations for cushion systems operating at conditions for which a linear theory predicts instability. The types of non-linearity that can occur are discussed, and an analysis is presented for a single cell flexible skirted plenum chamber constrained to move in pure heave only. Two cushion feed cases are considered: a plenum box supply and a duct. The results obtained by a Galerkin/describing function analysis are compared with those generated by a full numerical simulation. For the plenum box supply system, it is shown that the limit cycles can be suppressed by using a piston to introduce high frequency small amplitude volume oscillations into the plenum chamber.

  4. Impact Responses of Composite Cushioning System considering Critical Component with Simply Supported Beam Type

    Directory of Open Access Journals (Sweden)

    Fu-de Lu

    2014-04-01

    Full Text Available In some microelectronic products, one or several components can be idealized as simply supported beam type and viewed as vulnerable elements or critical component due to the fact that they are destroyed easily under impact loadings. The composite cushioning structure made of expanded polyethylene (EPE, and expanded polystyrene (EPS was utilized to protect the vulnerable elements against impact loadings during transportation. The vibration equations of composite cushioning system were deducted and virtual mass method was applied to predict impact behavior of critical component. Numerical results indicate that virtual mass method is appropriate for computing impact response of composite cushioning system with vulnerable element of simply supported beam type, which is affirmed by the fact that the impact responses of structure element in terms of velocity- and displacement-time curves are almost unchanged when virtual mass is smaller than a certain value. The results in this paper make it possible for installation of packaging optimization design.

  5. Examples of the application of the cause-effect ergonomic evaluation model to the wheelchair cushions.

    Science.gov (United States)

    Barberà-Guillem, Ricard; Page, Álvaro; Laparra, José; Durà, Juan V

    2015-01-01

    This article highlights the potential of the application of the cause-effect model for the ergonomic evaluation in the field of cushions. User involvement in the prescription and development of assistive devices have been identified a key aspect for positive interventions, although the reality is that we lack of systematic approaches and examples of best practices. The potential benefits are identified for the development of new products and in the prescription process. Additional research would be necessary to better link the characteristics of the cushions and users with the biomechanical and physiological performance of the interface cushion-user and the consequences measured in health, user perception and activity performance. This article shows examples of the relationship in this three levels from the point of view of the user perception.

  6. Research of air-cushion isolation effects on high arch dam reservoir

    Science.gov (United States)

    Zhang, Shao-Jie; Chen, Jiang; Zhang, Yuan-Ze; Liu, Hao-Wu

    2011-10-01

    A three-dimensional (3D) finite element model of air-cushion isolated arch dam is presented with the nonlinear gas-liquid-solid multi-field dynamic coupling effect taken into account. In this model, the displacement formulation in Lagrange method, pressure formulation in Euler method, nonlinear contact model based on Coulomb friction law are applied to the air-cushion, reservoir and contraction joint domain, respectively. The dynamic response of Jinping I arch dam with a height of 305 m is analyzed using the seismic records of the Wenchuan Earthquake in 2008. Numerical results show that the air-cushion isolation reduces significantly the hydrodynamic pressure as well as the opening width for the contraction joints of high arch dam.

  7. Applying ISO 16840–2 Standard to differentiate impact force dissipation characteristics of selection of commercial wheelchair cushions

    Directory of Open Access Journals (Sweden)

    Martin Ferguson-Pell, PhD

    2015-04-01

    Full Text Available Results from applying the International Organization for Standardization (ISO 16840–2 test method for determining the impact damping characteristics of 35 wheelchair cushions plus a high resilience (HR70 polyurethane reference foam sample are reported. The generation of impact forces when a wheelchair user either transfers onto a cushion or the wheelchair encounters rough terrain or bumps down a step can endanger the viability of tissues, especially if these forces occur repeatedly. The results demonstrate significant differences in the impact force dissipation characteristics of different cushion products but do not reliably identify differences in performance that can be attributed to descriptive information about cushion composition alone. Instead, these results demonstrate that the materials, proprietary design, and construction features of wheelchair cushions in combination dictate impact force dissipation properties. The results of a cluster analysis are used to generate a model that can be used to compare the impact damping properties obtained from the ISO 16840–2 test method with those of a range of cushions and the reference cushion. Manufacturers will therefore be able to provide users and clinicians with information about the impact force dissipation properties of the cushions that will enable them to make more informed product choices for achieving improved comfort and to protect skin integrity.

  8. 1986 CACTS International Conference on Air Cushion Technology, Toronto, Canada, Sept. 16-18, 1986, Preprints

    Science.gov (United States)

    MacEwen, W. R.

    The present conference on the design and development, innovative configurational concepts, test result analyses and operational characteristics of ACVs gives attention to design criteria for light, high-speed ACVs in desert environments, preliminary over-water tests of linear propellers, tests on high speed hovercraft icebreaking, and the performance of an air cushion crawler all-terrain vehicle. Also discussed are the use of ACVs as high speed ASW vehicles, performance criteria for air cushion heave dynamics, the bounce characteristics of an ACV's responsive skirt, and the use of hovercraft in ice enforcement.

  9. Ultra-structure of adipocytes in the digital cushion of ostrich (Stuthio Camelus foot pad

    Directory of Open Access Journals (Sweden)

    Amira Eid Derbalah

    2012-02-01

    Full Text Available The ultra-structural examination of adipocytes in the digital cushion of ostrich foot pad was performed to reveal the structural adaptation of adipocytes and elastic fibers of digital cushion to accommodate with fast movement of this unique bird. Two types of adipocytes were found, the first type was typical signet ring cells which had large fat droplets whose dimension dwarfed the cell organelles. The second type was diffused form with oval shaped adipocytes. Microfibillar aggregates of elastic fibers were closely packed and appeared to bead in a regular fashion. Some of this microfibrillar was reshaping adipocytes by making invagination of their plasma membrane.

  10. 1986 CACTS International Conference on Air Cushion Technology, Toronto, Canada, Sept. 16-18, 1986, Preprints

    Energy Technology Data Exchange (ETDEWEB)

    Macewen, W.R.

    1986-01-01

    The present conference on the design and development, innovative configurational concepts, test result analyses and operational characteristics of ACVs gives attention to design criteria for light, high-speed ACVs in desert environments, preliminary over-water tests of linear propellers, tests on high speed hovercraft icebreaking, and the performance of an air cushion crawler all-terrain vehicle. Also discussed are the use of ACVs as high speed ASW vehicles, performance criteria for air cushion heave dynamics, the bounce characteristics of an ACV's responsive skirt, and the use of hovercraft in ice enforcement.

  11. Output Model of Steel Plant

    Institute of Scientific and Technical Information of China (English)

    ZHANG Long-qiang; TIAN Nai-yuan; ZHANG Jin; XU An-jun

    2008-01-01

    Based on the requirement of compactivity, continuity, and high efficiency, and taking full advantage of cushion capability of flexible parts such as external refining in new generation steel plant, an output model of steel plant was established in terms of matching between BOF and caster. Using this model, the BOF nominal capacity is selected, the caster output and equipment amount are computed, and then the steel plant output is computed.

  12. Selective fluid cushion in the submucosal layer by water jet: advantage for endoscopic mucosal resection.

    Science.gov (United States)

    Kaehler, G F B A; Sold, M G; Fischer, K; Post, S; Enderle, M

    2007-01-01

    Numerous new techniques have recently been reported and described for the endoscopic mucosal resection of large superficial lesions of the gastrointestinal tract. We present here for the first time the application of a water jet dissector for mucosa elevation. In an ex vivo study, the effectiveness of a water jet dissector (Helix Hydro-Jet) placed directly on the stomach walls of 8 pigs was examined to create a mucosal elevation. After having determined optimal pressures, angle of application, and application times, 13 submucosal fluid cushions were produced in different areas of the stomach walls of 8 pigs in vivo, and the sizes of the resulting submucosal cushions were measured. Using pressures between 30 and 70 bar, it was routinely possible to create submucosal fluid cushions in the stomach wall ex vivo as well as in vivo. Histological examination showed a selective edema in the submucosa without damage to the deeper mucosal layers of the gastric wall. The capacity of a targeted high-pressure water jet to penetrate the mucosa and selectively create a fluid cushion in the submucosa facilitates endoscopic resection of the mucosa. This new method could contribute to ameliorate the endoscopic treatment of mucosal tumors which previously could not be resected endoscopically due to their size, extent, or location. Copyright 2007 S. Karger AG, Basel.

  13. An Analysis of Skill Requirements for Operators of Amphibious Air Cushion Vehicles (ACVs).

    Science.gov (United States)

    McKnight, A. James; And Others

    This report describes the skills required in the operation of an amphibious air cushion vehicle (ACV) in Army tactical and logistic missions. The research involved analyzing ACV characteristics, operating requirements, environmental effects, and results of a simulation experiment. The analysis indicates that ACV operation is complicated by an…

  14. An Analysis of Skill Requirements for Operators of Amphibious Air Cushion Vehicles (ACVs).

    Science.gov (United States)

    McKnight, A. James; And Others

    This report describes the skills required in the operation of an amphibious air cushion vehicle (ACV) in Army tactical and logistic missions. The research involved analyzing ACV characteristics, operating requirements, environmental effects, and results of a simulation experiment. The analysis indicates that ACV operation is complicated by an…

  15. A preliminary investigation into the design of pressure cushions and their potential applications for forearm robotic orthoses.

    Science.gov (United States)

    Alavi, N; Zampierin, S; Komeili, M; Cocuzza, S; Debei, S; Menon, C

    2017-05-08

    Load cells are often used in rehabilitation robotics to monitor human-robot interaction. While load cells are accurate and suitable for the stationary end-point robots used in rehabilitation hospitals, their cost and inability to conform to the shape of the body hinder their application in developing affordable and wearable robotic orthoses for assisting individuals in the activities of daily living. This exploratory work investigates the possibility of using an alternative technology, namely compliant polymeric air cushions, to measure interaction forces between the user and a wearable rigid structure. A polymeric air cushion was designed, analyzed using a finite element model (FEM), and tested using a bench-top characterization system. The cushions underwent repeatability testing, and signal delay testing from a step response while increasing the length of the cushion's tubes. Subsequently, a 3D printed wrist brace prototype was integrated with six polymeric air cushions and tested in static conditions where a volunteer exerted isometric pronation/supination torque and forces in vertical and horizontal directions. The load measured by integrating data recorded by the six sensors was compared with force data measured by a high quality load cell and torque sensor. The FEM and experimental data comparison was within the error bounds of the external differential pressure sensor used to monitor the pressure inside the cushion. The ratio obtained experimentally between the pressure inside the pressure cushion and the 8 N applied load deviated by only 1.28% from the FEM. A drift smaller than 1% was observed over 10 cycles. The rise times of the cushion under an 8 N step response for a 0.46, 1.03, and 2.02 m length tube was 0.45, 0.39, and 0.37 s. Tests with the wrist brace showed a moderate root mean square error (RMSE) between the force estimated by the pressure cushions and the external load cells. Specifically, the RMSE was 13 mNm, 500 mN, and 1.24 N for

  16. Co-occurrence of pathogenic and non-pathogenic Fusarium decemcellulare and Lasiodiplodia theobromae isolates in cushion galls disease of cacao (Theobroma cacao L.

    Directory of Open Access Journals (Sweden)

    Castillo Daynet Sosa del

    2016-04-01

    Full Text Available Flowery cushion gall of cacao is a disease complex with six types. Fusarium decemcellulare have been isolated from both flowery and green point galls and recognized as the etiological agent of the disease. In the present work we: i identified by ITS-rDNA sequencing and/or taxonomy the cultivable fungal species or Operative Taxonomic Units (OTUs associated with the five symptoms of cushion galls in cacao from Venezuela, and ii determined the gall inducing capacity on cacao peeled seeds after 45 days of inoculation with suspensions of mycelia/ spores from distinct isolate types. The whole isolate collection rendered an abundance of 113 isolates with a richness of 39 OTUs (27 and eight identified at the species or genera levels, respectively, and in unidentified fungi. The dominant recovered species (≈36% were F. decemcellulare and Lasiodiplodia theobromae. Some isolates of F. decemcellulare, L. theobromae, F. equiseti, Fusarium spp., F. solani, F. incarnatum, Rhizocthonia solani and Penicillium sp. were pathogenic. Some other isolates of the first six mentioned taxa behave as non-pathogenic. Furthermore, pathogenic and non-pathogenic isolates can also co-occur within a single plant and gall type. Moreover, 2-5 species within a single gall symptom in a single tree were identified (not necessarily at the same point in the tree, indicating a broad diversity of co-occurring taxa.

  17. Theoretical investigation of heave dynamics of an air cushion vehicle bag and finger skirt

    Science.gov (United States)

    Chung, Joon

    This thesis describes a theoretical investigation of the nonlinear and linear heave dynamics of an air cushion vehicle (ACV) equipped with a bag and finger skirt system with the purpose of understanding the skirt's effect on the vehicle heave dynamics. Throughout the course of this work, the pure heave motion of a two dimensional section of the skirt is investigated using several mathematical models. Both the nonlinear and linearized analyses include a detailed model of the skirt geometry, which is modelled as a combination of inelastic membranes and links. Air flow processes from the bag to the cushion and from the cushion to the atmosphere are assumed to be quasisteady, and the bag and cushion volumes are modelled as lumped pneumatic capacitances. The modulation of the escaping cushion air by skirt-ground contact is also included. The nonlinear simulations reveal that characteristically nonlinear dynamical phenomena such as period doubling and chaos can be expected to occur during the normal operation of ACVs. Furthermore, a configuration representative of a 37 tonne vehicle shows a resonance at frequencies in the range for which humans are most sensitive. Although these results thus show that some aspects of the bag and finger skirt heave dynamics can be highly nonlinear, they indicate that under certain circumstances, standard linear techniques can yield useful insights. Results from the linear analysis suggest that changes in skirt geometry cannot be used to radically modify the undesirable heave response of the bag and finger skirt, but reducing the skirt mass is quite effective. The pneumatic capacitance of the bag and cushion volume proves to be an important factor in the heave response. In particular, it contributes to heave instability. The air compressibility also affects heave response at high frequencies, with the effect becoming more prominent as the flow rate is reduced. The importance of unsteady fan effects on ACV dynamics is investigated by the

  18. 3D characterization of EMT cell density in developing cardiac cushions using optical coherence tomography (Conference Presentation)

    Science.gov (United States)

    Yu, Siyao; Gu, Shi; Zhao, Xiaowei; Liu, Yehe; Jenkins, Michael W.; Watanabe, Michiko; Rollins, Andrew M.

    2017-02-01

    Congenital heart defects (CHDs) are the most common birth defect, affecting between 4 and 75 per 1,000 live births depending on the inclusion criteria. Many of these defects can be traced to defects of cardiac cushions, critical structures during development that serve as precursors to many structures in the mature heart, including the atrial and ventricular septa, and all four sets of cardiac valves. Epithelial-mesenchymal transition (EMT) is the process through which cardiac cushions become populated with cells. Altered cushion size or altered cushion cell density has been linked to many forms of CHDs, however, quantitation of cell density in the complex 3D cushion structure poses a significant challenge to conventional histology. Optical coherence tomography (OCT) is a technique capable of 3D imaging of the developing heart, but typically lacks the resolution to differentiate individual cells. Our goal is to develop an algorithm to quantitatively characterize the density of cells in the developing cushion using 3D OCT imaging. First, in a heart volume, the atrioventricular (AV) cushions were manually segmented. Next, all voxel values in the region of interest were pooled together to generate a histogram. Finally, two populations of voxels were classified using either K-means classification, or a Gaussian mixture model (GMM). The voxel population with higher values represents cells in the cushion. To test the algorithm, we imaged and evaluated avian embryonic hearts at looping stages. As expected, our result suggested that the cell density increases with developmental stages. We validated the technique against scoring by expert readers.

  19. Use of weight-bearing MRI for evaluating wheelchair cushions based on internal soft-tissue deformations under ischial tuberosities

    Directory of Open Access Journals (Sweden)

    Amit Gefen, PhD

    2010-03-01

    Full Text Available Deep tissue injury (DTI is a severe type of pressure ulcer, in which damage initiates under intact skin, in soft tissues that are mechanically deformed by load-bearing bony prominences. Sitting-acquired DTI typically occurs in the gluteus muscles that could sustain deformations by the weight-bearing ischial tuberosities (ITs. No clinical method currently exists for measuring internal tissue deformations; so design and selection of wheelchair cushions are based mostly on meas-uring sitting pressures. Our objective was to evaluate the influence of different commercial cushions on internal soft-tissue deformations under the ITs, using weight-bearing magnetic resonance imaging (MRI. We specifically compared muscle, superficial fat, and effective (muscle and fat together tissue deformations while subjects (n = 10 sat on four cushions (two viscoelastic and two foam and directly on a rigid support. Deformations were maximal in muscle tissue (mean ~70%, twice more the amount than in fat (~30%. Effective soft-tissue deformations were ~50% to ~60%. Although cushions mildly reduced muscle deformations in the order of 10%, theoretically, our interpretation suggests that this deformation level adds safe sitting time. This study demonstrated that weight-bearing MRI is applicable for evaluating wheelchair cushions and, in the future, may be a tool to systematically support cushion design and selection.

  20. Sea Keeping Analysis of Air Cushion Vehicle with Different Wave Angles under the Operation Resistance

    Institute of Scientific and Technical Information of China (English)

    ZHOU Jia; TANG Wen-yong; ZHANG Sheng-kun

    2009-01-01

    The air cushion vehicle (ACV) sea keeping characteristic under different wave directions with the operation resistance is discussed with the couples of the heave, pitch roll motion and the pressure of the cushion.In previous researches, only wave and cross wave direction were discussed. Then a Matlab program is made to calculate the united frequency responses of heave, pitch and roll amplitude of the craft, under different wave frequencies and different wave directions. The results of the research depict some dangerous situations under which the sympathetic vibration happens in heave, pitch and roll motion and the amplitudes are extremely higher than those under the ordinary conditions. These results will be helpful in ACV design and operation.

  1. Feasibility report: Operation of light air cushion vehicle at McMurdo Sound, Antarctica

    Science.gov (United States)

    Dibbern, J. S.

    1987-02-01

    This report explores the viability of the use of an air cushion vehicle (ACV) or hovercraft to perform logistic and scientific support in the area of McMurdo Station, Antarctica. After a review of personnel assets and facilities at McMurdo Station to support the ACV plus a reconnaissance of the five major routes selected, it appears that an air cushion vehicle in the 1 to 1 1/2 ton payload class would be of significant value to support operations. It would reduce transit times for surface vehicle traverses on the routes selected and reduce requirements for expenditure of helicopter flight time in others. Of major significance is the ability to handle passenger/shuttle requirements between the Scott Base transition and Williams Field Skiway. Use of the ACV for high frequency passenger operations would help preserve the snow road for cargo operations during periods of road deterioration.

  2. Pin cushion plasmonic device for polarization beam splitting, focusing, and beam position estimation.

    Science.gov (United States)

    Lerman, Gilad M; Levy, Uriel

    2013-03-13

    Great hopes rest on surface plasmon polaritons' (SPPs) potential to bring new functionalities and applications into various branches of optics. In this paper, we demonstrate a pin cushion structure capable of coupling light from free space into SPPs, split them based on the polarization content of the illuminating beam of light, and focus them into small spots. We also show that for a circularly or randomly polarized light, four focal spots will be generated at the center of each quarter circle comprising the pin cushion device. Furthermore, following the relation between the relative intensity of the obtained four focal spots and the relative position of the illuminating beam with respect to the structure, we propose and demonstrate the potential use of our structure as a miniaturized plasmonic version of the well-known four quadrant detector. Additional potential applications may vary from multichannel microscopy and multioptical traps to real time beam tracking systems.

  3. BMPER Promotes Epithelial-Mesenchymal Transition in the Developing Cardiac Cushions.

    Directory of Open Access Journals (Sweden)

    Laura Dyer

    Full Text Available Formation of the cardiac valves is an essential component of cardiovascular development. Consistent with the role of the bone morphogenetic protein (BMP signaling pathway in cardiac valve formation, embryos that are deficient for the BMP regulator BMPER (BMP-binding endothelial regulator display the cardiac valve anomaly mitral valve prolapse. However, how BMPER deficiency leads to this defect is unknown. Based on its expression pattern in the developing cardiac cushions, we hypothesized that BMPER regulates BMP2-mediated signaling, leading to fine-tuned epithelial-mesenchymal transition (EMT and extracellular matrix deposition. In the BMPER-/- embryo, EMT is dysregulated in the atrioventricular and outflow tract cushions compared with their wild-type counterparts, as indicated by a significant increase of Sox9-positive cells during cushion formation. However, proliferation is not impaired in the developing BMPER-/- valves. In vitro data show that BMPER directly binds BMP2. In cultured endothelial cells, BMPER blocks BMP2-induced Smad activation in a dose-dependent manner. In addition, BMP2 increases the Sox9 protein level, and this increase is inhibited by co-treatment with BMPER. Consistently, in the BMPER-/- embryos, semi-quantitative analysis of Smad activation shows that the canonical BMP pathway is significantly more active in the atrioventricular cushions during EMT. These results indicate that BMPER negatively regulates BMP-induced Smad and Sox9 activity during valve development. Together, these results identify BMPER as a regulator of BMP2-induced cardiac valve development and will contribute to our understanding of valvular defects.

  4. Assessing the Operational Readiness of Landing Craft Air Cushion Vessels Using Statistical Modeling

    Science.gov (United States)

    2010-09-01

    Beachmaster Unit ONE C/A Craft Alteration CASREP Casualty Report CBM Condition Based Maintenance CCI Corrosion Control Inspection CESE...Allowance List CSMP Current Ship Maintenance Project CSR Craft Status Report CRAFTALT Craft Alteration C4N Command, Control , Communications...Assault Craft Unit (ACU)-5 manages a fleet of 40 Landing Craft Air Cushion (LCAC) hovercrafts from its base at Marine Corps Base Camp Pendleton

  5. Evaluating the Vibration Isolation of Soft Seat Cushions Using AN Active Anthropodynamic Dummy

    Science.gov (United States)

    LEWIS, C. H.; GRIFFIN, M. J.

    2002-05-01

    Seat test standards require human subjects to be used for measuring the vibration isolation of vehicle seats. Anthropodynamic dummies, based on passive mass-spring- damper systems, have been developed for testing seats but their performance has been limited at low excitation magnitudes by non-linear phenomena, such as friction in the mechanical components that provide damping. The use of an electrodynamic actuator to generate damping forces, controlled by feedback from acceleration and force transducers, may help to overcome these limitations and provide additional benefits. The transmissibilities of five foam cushions have been measured using an actively controlled anthropodynamic dummy, in which damping and spring forces were supplied by an electrodynamic actuator. The dummy could be set up to approximate alternative single-degree-of-freedom and two-degree-of-freedom apparent mass models of the seated human body by varying motion feedback parameters. Cushion transmissibilities were also measured with nine human subjects, having an average seated weight similar to the dummy. At frequencies greater than 4 Hz, mean cushion transmissibilities measured with subjects were in closer agreement with the transmissibilities obtained with a two degree-of-freedom dummy than with a single degree-of-freedom dummy. However, at frequencies between 2 and 4 Hz, cushion transmissibilities obtained with the two-degree-of-freedom dummy showed consistently larger differences from mean transmissibilities with subjects than single-degree-of-freedom dummies, indicating a need for further development of human apparent mass models to account for the effects of magnitude and spectral content of the input motion. Vertical vibration isolation efficiencies (SEAT values) of the five foams were measured with four input motions, including three motions measured in a car. The SEAT values obtained using the active dummy were highly correlated with the median SEAT values obtained with the nine human

  6. 小型 air cushion vehicle の試作研究

    OpenAIRE

    小倉, 一彦; 岡田, 幸夫; 木原, 勇; 土伏, 悌之

    2000-01-01

    In studying "Engineering" , the fundamental matter is "Manufacturing (Mono-zukuri)". But the students of Electric-Mechanical Engineering Department have little time for manufacturing the complete whole systems, except for Graduation Studies. In order to let the students experience "Manufacturing" of a whole system, we selected a Light Air Cushion Vehicle (ACV) as a subject of our study. In this paper, the process of manufacturing an ACV is reported.

  7. Design and milling manufacture of polyurethane custom contoured cushions for wheelchair users

    Directory of Open Access Journals (Sweden)

    Wilson Kindlein Junior

    2011-09-01

    Full Text Available BackgroundThe design of custom contoured cushions manufactured inflexible polyurethane foams is an option to improvepositioning and comfort for people with disabilities thatspend most of the day seated in the same position. Thesesurfaces increase the contact area between the seat and theuser. This fact contributes to minimise the local pressuresthat can generate problems like decubitus ulcers. Thepresent research aims at establishing development routesfor custom cushion production to wheelchair users. Thisstudy also contributes to the investigation of ComputerNumerical Control (CNC machining of flexible polyurethanefoams.MethodThe proposed route to obtain the customised seat beganwith acquiring the user’s contour in adequate posturethrough plaster cast. To collect the surface geometry, thecast was three-dimensionally scanned and manipulated inCAD/CAM software. CNC milling parameters such as tools,spindle speeds and feed rates to machine flexiblepolyurethane foams were tested. These parameters wereanalysed regarding the surface quality. The best parameterswere then tested in a customised seat. The possibledimensional changes generated during foam cutting wereanalysed through 3D scanning. Also, the customised seatpressure and temperature distribution was tested.ResultsThe best parameters found for foams with a density of50kg/cm3 were high spindle speeds (24000 rpm and feedrates between 2400–4000mm/min. Those parameters didnot generate significant deformities in the machinedcushions. The custom contoured cushion satisfactorilyincreased the contact area between wheelchair and user, asit distributed pressure and heat evenly.ConclusionThrough this study it was possible to define routes for thedevelopment and manufacturing of customised seats usingdirect CNC milling in flexible polyurethane foams. It alsoshowed that custom contoured cushions efficientlydistribute pressure and temperature, which is believed tominimise tissue lesions such as pressure

  8. Analysis of Trunk Flutter in an Air Cushion Landing System. User’s Manual.

    Science.gov (United States)

    1979-11-01

    b Vertical distance between inner and outer trunk attachment point CGAP C Discharge coefficient gap flow g CKK Polytropic expansion coefficient...at exit (separation) QFAN QFAN Fan flow QGAP QGAP Gap flow QIN QIN Flow to trunk 96 Program Variable Name Symbol Explanation QINT Momentum change...integral A QOUT Qout Flow, out of trunk QTA QTA Flow, trunk to atmosphere QTC QTC Flow, trunk to cushion QTOT Total gap flow QTRI1 QTR Flow, trim valve

  9. Wax beads as cushioning agents during the compression of coated diltiazem pellets.

    Science.gov (United States)

    Vergote, G J; Kiekens, F; Vervaet, C; Remon, J P

    2002-11-01

    Placebo particles were mixed with film-coated diltiazem pellets to evaluate them as cushioning agents during tabletting in order to protect the film coat from damage. The cushioning properties of alpha-lactose monohydrate granules, microcrystalline cellulose pellets and wax/starch beads were evaluated by comparing the dissolution profile of the coated pellets before and after compression (compression force 10 kN). Only the tablet formulations containing wax/starch beads provided protection to the film coat. However, the dissolution rate of tablets formulated with waxy maltodextrin/paraffinic wax placebo beads was too slow as the tablets did not disintegrate. Adding 50% (w/w) drum-dried corn starch/Explotab/paraffinic wax beads to the formulation was the optimal amount of cushioning beads to provide sufficient protection for the film coat and yield disintegrating tablets. Using a compression simulator, the effect of precompression force and compression time on the dissolution rate was found to be insignificant. The diametral crushing strength of tablets containing 50% (w/w) drum-dried corn starch/Explotab/paraffinic wax beads was about 25.0 N (+/-0.3 N), with a friability of 0.4% (+/-0.04%). This study demonstrates that adding deformable wax pellets minimizes the damage to film-coated pellets during compression.

  10. Effects of insoles and additional shock absorption foam on the cushioning properties of sport shoes.

    Science.gov (United States)

    Chiu, Hung-Ta; Shiang, Tzyy-Yuang

    2007-05-01

    The purpose of this study was to investigate the effects of insoles and additional shock absorption foam on the cushioning properties of various sport shoes with an impact testing method. Three commercial sport shoes were used in this study, and shock absorption foam (TPE5020; Vers Tech Science Co. Ltd., Taiwan) with 2-mm thickness was placed below the insole in the heel region for each shoe. Eight total impacts with potential energy ranged from 1.82 to 6.08 J were performed onto the heel region of the shoe. The order of testing conditions was first without insole, then with insole, and finally interposing the shock absorption foam for each shoe. Peak deceleration of the striker was measured with an accelerometer attached to the striker during impact. The results of this study seemed to show that the insole or additional shock absorption foam could perform its shock absorption effect well for the shoes with limited midsole cushioning. Further, our findings showed that insoles absorbed more, even up to 24-32% of impact energy under low impact energy. It seemed to indicate that insoles play a more important role in cushioning properties of sport shoes under a low impact energy condition.

  11. A comparative sudy of two pressure relieving techniques on three different wheelchair cushions

    Directory of Open Access Journals (Sweden)

    C. Eksteen

    2006-02-01

    Full Text Available Introduction: Pressure relief done by a spinal cordinjured patient is of utmost importance in order to prevent pressuresore formation. Some pressure-relieving techniques are describedin previous literature, but their effectivity has not yet been deter-mined on different wheelchair cushions.Null Hypothesis (H0: The null hypothesis (H0 stated for thistudy is that there is no difference in the effectivity of forwardleaning and forward leaning towards the left as pressure relievingtechniques for quadriplegic wheelchair users over the differenwheelchair cushions.Design: An analytical experimental study design using a convenient sample group of ten complete lesion quadriplegics (C6 to T1 was performed at the Physiotherapy Department,University of Pretoria.Method: Interface pressure (in mmHg over the ischial tuberosities and upper thigh areas was measured using theTalley Oxford Pressure Monitor MKII with a 12-way matrix cell system.Results and Conclusion: The Friedman test for associated observations indicated statistically that the leaning  diagonally forward pressure relieving technique is more effective for all three wheelchair cushions used in this study.

  12. Volatile organic chemical emissions from carpet cushions: Screening measurements. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hodgson, A.T.; Phan, T.A.

    1994-05-01

    The US Consumer Product Safety Commission (CPSC) has received complaints from consumers regarding the occurrence of adverse health effects following the installation of new carpeting (Schachter, 1990). Carpet systems are suspected of emitting chemicals which may be the cause of these complaints, as well as objectionable odors. Carpets themselves have been shown to emit a variety of volatile organic compounds (VOCs). The objective of this study was to screen the representative samples of carpet cushions for emissions of individual VOCS, total VOCs (TVOC), formaldehyde, and, for the two types of polyurethane cushions, isomers of toluene diisocyanate (TDI). The measurements of VOCS, TVOC and formaldehyde were made over six-hour periods using small-volume (4-L) dynamic chambers. Sensitive gas chromatography-mass spectrometry (GC-MS) techniques were used to identify many of the VOCs emitted by the cushion samples and to obtain quantitative estimates of the emission rates of selected compounds. Separate screening measurements were conducted for TDI. The data from the screening measurements were used by the CPSC`s Health Sciences Laboratory to help design and conduct week-long measurements of emission rates of selected compounds.

  13. Determination of turnover and cushion gas volume of a prospected gas storage reservoir under uncertainty

    Energy Technology Data Exchange (ETDEWEB)

    Gubik, A. [RAG-AG Wien (Austria); Baffoe, J.; Schulze-Riegert, R. [SPT Group GmbH, Hamburg (Germany)

    2013-08-01

    Gas storages define a key contribution for building a reliable gas supply chain from production to consumers. In a competitive gas market with short reaction times to seasonal and other gas injection and extraction requirements, gas storages also receive a strong focus on availability and precise prediction estimates for future operation scenarios. Reservoir management workflows are increasingly built on reservoir simulation support for optimizing production schemes and estimating the impact of subsurface uncertainties on field development scenarios. Simulation models for gas storages are calibrated to geological data and accurate reproduction of historical production data are defined as a prerequisite for reliable production and performance forecasts. The underlying model validation process is called history matching, which potentially generates alternative simulation models due to prevailing geological uncertainties. In the past, a single basecase reference model was used to predict production capacities of a gas storage. The working gas volume was precisely defined over a contracted plateau delivery and the required cushion gas volume maintains the reservoir pressure during the operation. Cushion and working gas Volume are strongly dependent on reservoir parameters. In this work an existing depleted gas reservoir and the operation target as a gas storage is described. Key input data to the reservoir model description and simulation is reviewed including production history and geological uncertainties based on large well spacing, limited core and well data and a limited seismic resolution. Target delivery scenarios of the prospected gas storage are evaluated under uncertainty. As one key objective, optimal working gas and cushion gas volumes are described in a probabilistic context reflecting geological uncertainties. Several work steps are defined and included in an integrated workflow design. Equiprobable geological models are generated and evaluated based on

  14. Spatial patterns of rockfall in recently deglaciated high-alpine rock faces: Analysing rockfall release zones and volumes based on a multiannual LiDAR time series, Kitzsteinhorn, Austria.

    Science.gov (United States)

    Hartmeyer, Ingo; Keuschnig, Markus; Delleske, Robert; Wichmann, Volker; Hoffmann, Thomas; Schrott, Lothar

    2015-04-01

    Rock instabilities in high-alpine areas represent a considerable risk factor for man and infrastructure. In the Alps numerous, mainly visual, observations suggest an increasing occurrence of rockfall events potentially associated to climate warming. However, unbiased high-precision information on the location of rockfall release zones and the size of event volumes is scarce. Thus, frequency/magnitude patterns of high-alpine rockfall often remain elusive. The presented study addresses the need for systematically acquired, objective field data by presenting an extensive, multiannual LiDAR time series from a high-alpine (peri)glacial environment. The study area is located in the summit region of the Kitzsteinhorn (3.203 m), Hohe Tauern Range, Austria. The beginning of the terrestrial laserscanning (TLS) monitoring campaign dates back to July 2011. Since then six rock faces have been scanned repeatedly at an interval of 1-2 months during the snow-free summer season (June to October). The investigated rock faces predominantly consist of calcareous mica-schist and differ in terms of height, slope, aspect, and discontinuity orientation. The rock faces are partially underlain by permafrost, their combined surface area is approx. 1.3 km². They are located directly adjacent to the Schmiedingerkees cirque glacier, which has retreated and thinned significantly in recent decades (downwasting rate ~1.5 m/a). TLS data acquisition was performed using a Riegl LMS-Z620i. During data acquisition no permanently fixed installations and no artificial reflective markers were used. This is in line with the requirement to develop a quick, flexible methodology that can be applied not only at the Kitzsteinhorn, but also in other, similar environments. For data post-processing a new analysis procedure has been developed which allows (i) point cloud alignment by surface geometry matching, (ii) objective, automated discrimination between measurement errors und real surface changes, and (iii

  15. THE COMPLEX OF STANDS FOR TESTING THE AIR CUSHION CHASSIS OF AIRCRAFT AND VEHICLES

    Directory of Open Access Journals (Sweden)

    2016-01-01

    Full Text Available This article deals with a set of stands made in NIMK TSAGI for testing and creating the air cushion chassis for the aircraft and vehicles. It allows to fully embrace the process of developing and constructing the air cushion chassis for air- craft and solve problems relating to peculiarities of such aircraft on the takeoff, landing and movement in the elementary prepared and unprepared soil runways, flat terrain and water areas. The complex includes: the experimental installation to study aeroelasticity phenomena of the chassis in the extending and retracting process with simulation of aircraft and ekran- oplane takeoff and landing modes in the air flow, including the wind tunnels; the experimental stand with vertical screen for testing of ekranoplane models in T-5 wind tunnel of NIMC TsAGI, permitting to simultaneously vary the model’s posi- tion relatively to the screen, roll, pitch (angle of attack, and banking; mobile experimental stand with contact crawler gear, for experimental determination and comparative evaluation of the chassis with different patterns of formation and air cush- ion fences for all-year-round testing in natural conditions at elementary-prepared and unprepared sites and water areas. Based on mathematical simulation of flow past in the wind tunnel the possibility of use booth stand with vertical screen and experimental installation to study aeroelasticity phenomena of the chassis for experimental studies, respectively, by defini- tion of the aerodynamic characteristics of forces and moments of the air cushion aircraft and ekranoplanes models and the research of phenomena of aeroelasticity of flexible fencing is substantiated.

  16. Parameter Estimation and Verification of Unmanned Air Cushion Vehicle (UACV System

    Directory of Open Access Journals (Sweden)

    Ab Rashid Mohd Zamzuri

    2017-01-01

    Full Text Available This project is mainly about the dynamic modelling and parameter estimation of Unmanned Air Cushion Vehicle (UACV. The purpose of developing mathematical model of the Unmanned Air Cushion Vehicle (UACV is due to its under actuated nonlinearities where it has less input compared to the output required. This system able to maneuver over land, water and other surfaces either at certain speed or maintain at a stationary position. In order to model the UACV, the system is set to have two propellers which are responsible to lift the vehicle by forcing high pressure air under the system. The air inflates the “skirt” under the vehicle, causing it to rise above the surface while another two propellers are used to steer the UACV forward. UACV system can be considered as under actuated since it possess fewer controller inputs that its degree of freedom. The system’s motions are defined by the six degrees of freedom which are; heaved, sway and surge. Another three components are rotational motions which can be elaborated as roll, pitch and yaw. The problem related to UACV is normally related to obtaining accurate parameters of the system to be included into the mathematical model of the system. This is due to the body inertia of the system during the static and moving condition. Besides, the air that flows into the UACV skirt to create the cushion causes imbalance and will affect the system stability and controllability. In this research, UACV need to be mathematically modelled using Euler-Lagrange method. Then, parameters of the system can be obtained through direct calculation and Solidworks software. The parameters acquired are compared and verified using simulation and experimental studies.

  17. A Study of Maneuvering Control for an Air Cushion Vehicle Based on Back Propagation Neural Network

    Institute of Scientific and Technical Information of China (English)

    LU Jun; HUANG Guo-liang; LI Shu-zhi

    2009-01-01

    A back propagation (BP) neural network mathematical model was established to investigate the maneuvering control of an air cushion vehicle (ACV). The calculation was based on four-freedom-degree model experiments of hydrodynamics and aerodynamics. It is necessary for the ACV to control the velocity and the yaw rate as well as the velocity angle at the same time. The yaw rate and the velocity angle must be controlled correspondingly because of the whipping, which is a special characteristic for the ACV. The calculation results show that it is an efficient way for the ACV's maneuvering control by using a BP neural network to adjust PID parameters online.

  18. Do Wages Continue Increasing at Older Ages? Evidence on the Wage Cushion in the Netherlands

    OpenAIRE

    Deelen, Anja; Euwals, Rob

    2014-01-01

    In this study, we investigate the anatomy of older workers’ wages. The central question is whether the wage cushion—i.e., the difference between actual wages and collectively agreed-upon (maximum) contractual wages—contributes to the fact that wages continue increasing at older ages. We follow the wages of individual workers in twenty-two sectors of industry in the Netherlands using administrative data for the period 2006 – 2010. In the public sector, we find no evidence of a wage cus...

  19. Effectiveness of Disc 'O' Sit cushions on attention to task in second-grade students with attention difficulties.

    Science.gov (United States)

    Pfeiffer, Beth; Henry, Amy; Miller, Stephanie; Witherell, Suzie

    2008-01-01

    This study investigated the effectiveness of a type of dynamic seating system, the Disc 'O' Sit cushion (Gymnic, Osoppo, Italy), for improving attention to task among second-grade students with attention difficulties. Sixty-three second-grade students participated in the study. Using a randomized controlled trial design, 31 students were assigned to a treatment group, and 32 were assigned to a control group. Treatment group participants used Disc 'O' Sit cushions throughout the school day for a 2-week period. The teachers completed the Behavior Rating Inventory of Executive Functioning (Gioia, Isquith, Guy, & Kenworthy, 1996) for each participant before and after the intervention. An analysis of variance identified a statistically significant difference in the attention to task before and after the intervention for the treatment group. The results of the study provide preliminary evidence for the use of the Disc 'O' Sit cushion as an occupational therapy intervention to improve attention in the school setting.

  20. The efficacy of a removable vacuum-cushioned cast replacement system in reducing plantar forefoot pressures in diabetic patients

    NARCIS (Netherlands)

    S.A. Bus; R. Waaijman; M. Arts; H. Manning

    2009-01-01

    Background: The purpose of this study was to determine the plantar forefoot offloading efficacy of a new prefabricated vacuum-cushioned cast replacement system designed for foot ulcer treatment in neuropathic diabetic patients. Methods: Fifteen diabetic subjects with peripheral neuropathy underwent

  1. Distribution of Prokaryotic Abundance and Microbial Nutrient Cycling Across a High-Alpine Altitudinal Gradient in the Austrian Central Alps is Affected by Vegetation, Temperature, and Soil Nutrients.

    Science.gov (United States)

    Hofmann, Katrin; Lamprecht, Andrea; Pauli, Harald; Illmer, Paul

    2016-10-01

    Studies of the altitudinal distributions of soil microorganisms are rare or have led to contradictory results. Therefore, we studied archaeal and bacterial abundance and microbial-mediated activities across an altitudinal gradient (2700 to 3500 m) on the southwestern slope of Mt. Schrankogel (Central Alps, Austria). Sampling sites distributed over the alpine (2700 to 2900 m), the alpine-nival (3000 to 3100 m), and the nival altitudinal belts (3200 to 3500 m), which are populated by characteristic plant assemblages. Bacterial and archaeal abundances were measured via quantitative real-time PCR (qPCR). Moreover, microbial biomass C, microbial activity (dehydrogenase), and enzymes involved in carbon (CM-cellulase), nitrogen (protease), phosphorus (alkaline phosphatase), and sulfur (arylsulfatase) cycling were determined. Abundances, microbial biomass C, and activities almost linearly decreased along the gradient. Archaeal abundance experienced a sharper decrease, thus pointing to pronounced sensitivity toward environmental harshness. Additionally, abundance and activities were significantly higher in soils of the alpine belt compared with those of the nival belt, whereas the alpine-nival ecotone represented a transitional area with intermediate values, thus highlighting the importance of vegetation. Archaeal abundance along the gradient was significantly related to soil temperature only, whereas bacterial abundance was significantly related to temperature and dissolved organic carbon (DOC). Soil carbon and nitrogen concentrations explained most of the variance in enzyme activities involved in the cycling of C, N, P, and S. Increasing temperature could therefore increase the abundances and activities of microorganisms either directly or indirectly via expansion of alpine vegetation to higher altitudes and increased plant cover.

  2. PV-ETFE 气枕结构温度实测研究%Field measurement of temperature of PV-ETFE cushion structures

    Institute of Scientific and Technical Information of China (English)

    胡建辉; 陈务军; 赵兵; 宋浩

    2015-01-01

    To investigate temperature characteristics of the ethylene‐tetra‐fluoro‐ethylene (ETFE) cushion integrated flexible amorphous silicon photovoltaic panels (PV‐ETFE for short), two types of PV‐ETFE cushions were designed. Cushion 1 was a three‐layer ETFE cushion integrated PV on sur‐face of its middle layer and cushion 2 was a double‐layer ETFE cushion integrated PV on surface of its top layer. Then, temperature of the two PV‐ETFE cushions in summer was field‐measured. The re‐sults show that temperature differences between the two PV‐ETFE cushions were 35. 4 ℃ for PV and 26. 2℃ for ETFE foils, the major influencing factors for ETFE foil of cushion 1, ETFE foil of cushion 2 and PV are the air temperature in cushion 1, air flow outside the cushion 2, and shade and angle of incidence of the solar irradiance, respectively.%为了研究柔性非晶硅薄膜光伏电池‐乙烯四氟乙烯共聚物(简称PV‐ETFE)气枕结构的温度特征,设计了由三层ET FE气枕与集成于其中层膜上表面PV组成的气枕1及由双层ET FE气枕与集成于其上层膜上表面PV组成的气枕2,实测了两种气枕的PV和ET FE薄膜的夏季温度数据.通过分析得到:两种气枕的PV和ET FE薄膜温度差分别为35.4℃和26.2℃;气枕1和气枕2 ET FE薄膜受气枕内空气温度和气枕外空气流动影响明显;PV温度受阴影及太阳光入射角影响.

  3. Progress report on Bertelsen research and development of an air cushion crawler all-terrain vehicle

    Science.gov (United States)

    Bertelsen, W. R.

    1987-06-01

    The ACV is an exceptional amphibian but it is not, nor is any other existing craft, an all-terrain vehicle (ATV). Using the best elements of the ACV in an air-cushion crawler tractor, a true ATV can be attained. A conventional crawler drive train will propel two tracks as pressurized, propulsive pontoons. The key to a successful ATV is in perfecting efficient, durable, sliding seals to allow the belt to move in its orbit around the track unit and maintain its internal pressure. After deriving the adequate seal, a 12 inch wide x 86 inch long endless rubber belt was fitted bilateral seals and slide plates with internal guide wheels fore and aft with a 21 inch wheel base. From this approximately one-quarter scale model, full-scale air track crawlers, true ATVs, of any size and capacity can be produced.

  4. 重叠结构缓冲材料缓冲性能分析%Analysis of Cushioning Properties for Cushioning Materials with Overlapping Structures of EPE and EPS Via Finite Element Method

    Institute of Scientific and Technical Information of China (English)

    宋晓利; 刘全校; 张改梅; 孟繁珺; 生雪莹

    2016-01-01

    为了研究EPE厚度的变化对重叠结构缓冲材料缓冲性能的影响,发泡聚乙烯( Expanded Polyethylene,EPE)及发泡聚丙烯( Expanded Polystyrene,EPS)所组成的重叠结构的缓冲材料缓冲性能变化情况,采用有限元法对 EPE 及EPS所组成的重叠结构的缓冲材料的缓冲性能进行了分析。结果表明:随着EPE厚度的增加,最大加速度及最小动态缓冲系数呈下降趋势,但不呈线性关系,且缓冲系数的变化幅度不大。当EPE的厚度达到总厚度的75%时,重叠结构缓冲材料的最大加速度及最小动态缓冲系数最小;随着EPE厚度的增加,最小缓冲系数的静应力会逐渐向右移动,缓冲材料的抗压强度越来越好。%In order to study the effect of EPE’s thickness on the cushioning properties of the cushioning materials which were made of Expanded Polyethylene ( EPE ) and Expanded Polystyrene ( EPS) ,the cushioning properties of the cushioning materials are analyzed based on the finite element method. The results show that with the increase of EPE’s thickness, the maximum acceleration and static stress are not proportional and decreasing. The change of the buffer coefficient is not very large. When the thickness of EPE is 75%, the maximum ac-celeration and minimum dynamic buffer coefficient of the cushioning materials is minimum. With the increase of EPE’s thickness, the static stress of the minimum buffer coefficient will move to the right. The compressive strength of the cushioning materials is better and better.

  5. 1985 Joint International Conference on Air Cushion Technology, Rockville, MD, September 24-26, 1985, Preprints and Late Papers

    Science.gov (United States)

    Amyot, J. R.

    1985-12-01

    Papers are presented on the effect of a resonant skirt on ACV seakeeping, aerodynamic characteristics of a bag-cone skirt, and a calculation of the static forces acting on ACV bag-finger skirts. Also considered are tactical problems relating to the hovercraft application of marine gas turbines, development of the Air Cushion Equipment Transporter, prevention of propeller Foreign Object Damage, and air propellers and their environmental problems on ACVs. Other topics include the maneuvering simulation of an Antarctic hovercraft, computer-aided conceptual design of air ACVs, the use of model-test data for predicting full-scale ACV resistance, and passive control of air cushion heave dynamics. Papers are also presented on hovercraft in low enforcement, managing LCAC in the evolving acquisition environment, and SES and ACV for naval mission.

  6. 单片机控制的冷暖坐垫%Cushion Controlled By Single-Chip

    Institute of Scientific and Technical Information of China (English)

    林建春

    2011-01-01

    介绍了一种利用ATmega8单片机控制帕尔贴半导体组件制冷、制热的坐垫。坐垫内置水管与外部水箱连通。根据帕尔贴原理,对水箱内的水制冷或加热,并通过微型泵进行水循环,使坐垫的温度与水箱温度保持一致。%This paper introduces the cushion controlled by Peltier to cool or heat by ATmega8 Single-Chip.The cushion has built-in water pipes,with water pipes connected with the external tank.According to the principle of Peltier,water in the tank is cooled or heated,and water circulation is realized by the micro-pump,keeping temperature of the cushion the same with the water temperature.

  7. Experimental investigation of the optimization of stilling basin with shallow- water cushion used for low Froude number energy dissipation

    Institute of Scientific and Technical Information of China (English)

    李连侠; 廖华胜; 刘达; 蒋胜银

    2015-01-01

    Energy dissipations induced by the hydraulic jump and the trajectory jet are the most widely known as the two dissipation modes at the downstream of flood discharging structures, which are often considered quite different even contradictory. However, such two energy dissipators can be used jointly and harmonically. In this paper, a new type of stilling basin with a shallow-water cushion and a triangular bottom deflector is proposed based on two different scale physical model tests of the flood discharging tunnel No.2 of Luding hydropower project. The experimental results show that the flow regime of the hydraulic jump in the presented stilling basin with bottom deflector enjoys a good and stable performance within a large range of flow rates and the energy dissipation rate is considerably high as compared to the conventional stilling basin even at a low Froude number. The results also indicate that the stilling basin with triangular bottom deflector has a better performance in improving the potential cavitation erosion according to the analysis of the pressure and the cavitation number compared to the trapezoidal one. The proposed new type of shallow-cushion stilling basin with a shallow-water cushion can be applied in similar energy dissipation projects with low Froude number and large range of flow rates.

  8. Motion analysis of wheelchair propulsion movements in hemiplegic patients: effect of a wheelchair cushion on suppressing posterior pelvic tilt.

    Science.gov (United States)

    Kawada, Kyohei; Matsuda, Tadamitsu; Takanashi, Akira; Miyazima, Shigeki; Yamamoto, Sumiko

    2015-03-01

    [Purpose] This study sought to ascertain whether, in hemiplegic patients, the effect of a wheelchair cushion to suppress pelvic posterior tilt when initiating wheelchair propulsion would continue in subsequent propulsions. [Subjects] Eighteen hemiplegic patients who were able to propel a wheelchair in a seated position participated in this study. [Methods] An adjustable wheelchair was fitted with a cushion that had an anchoring function, and a thigh pad on the propulsion side was removed. Propulsion movements from the seated position without moving through three propulsion cycles were measured using a three-dimensional motion analysis system, and electromyography was used to determine the angle of pelvic posterior tilt, muscle activity of the biceps femoris long head, and propulsion speed. [Results] Pelvic posterior tilt could be suppressed through the three propulsion cycles, which served to increase propulsion speed. Muscle activity of the biceps femoris long head was highest when initiating propulsion and decreased thereafter. [Conclusion] The effect of the wheelchair cushion on suppressing pelvic posterior tilt continued through three propulsion cycles.

  9. A nanometric cushion for enhancing scratch and wear resistance of hard films.

    Science.gov (United States)

    Gotlib-Vainshtein, Katya; Girshevitz, Olga; Sukenik, Chaim N; Barlam, David; Cohen, Sidney R

    2014-01-01

    Scratch resistance and friction are core properties which define the tribological characteristics of materials. Attempts to optimize these quantities at solid surfaces are the subject of intense technological interest. The capability to modulate these surface properties while preserving both the bulk properties of the materials and a well-defined, constant chemical composition of the surface is particularly attractive. We report herein the use of a soft, flexible underlayer to control the scratch resistance of oxide surfaces. Titania films of several nm thickness are coated onto substrates of silicon, kapton, polycarbonate, and polydimethylsiloxane (PDMS). The scratch resistance measured by scanning force microscopy is found to be substrate dependent, diminishing in the order PDMS, kapton/polycarbonate, Si/SiO2. Furthermore, when PDMS is applied as an intermediate layer between a harder substrate and titania, marked improvement in the scratch resistance is achieved. This is shown by quantitative wear tests for silicon or kapton, by coating these substrates with PDMS which is subsequently capped by a titania layer, resulting in enhanced scratch/wear resistance. The physical basis of this effect is explored by means of Finite Element Analysis, and we suggest a model for friction reduction based on the "cushioning effect" of a soft intermediate layer.

  10. Modeling, simulation & optimization of the landing craft air cushion fleet readiness.

    Energy Technology Data Exchange (ETDEWEB)

    Engi, Dennis

    2006-10-01

    The Landing Craft Air Cushion is a high-speed, over-the-beach, fully amphibious landing craft capable of carrying a 60-75 ton payload. The LCAC fleet can serve to transport weapons systems, equipment, cargo and personnel from ship to shore and across the beach. This transport system is an integral part of our military arsenal and, as such, its readiness is an important consideration for our national security. Further, the best way to expend financial resources that have been allocated to maintain this fleet is a critical Issue. There is a clear coupling between the measure of Fleet Readiness as defined by the customer for this project and the information that is provided by Sandia's ProOpta methodology. Further, there is a richness in the data that provides even more value to the analyst. This report provides an analytic framework for understanding the connection between Fleet Readiness and the output provided by Sandia's ProOpta software. Further, this report highlights valuable information that can also be made available using the ProOpta output and concepts from basic probability theory. Finally, enabling assumptions along with areas that warrant consideration for further study are identified.

  11. Molecular analysis of the nondisjoined chromosome in trisomy 21 with and without endocardial cushion defects

    Energy Technology Data Exchange (ETDEWEB)

    Zittergruen, M.M.; Murray, J.C.; Lauer, R.M. [Univ. of Iowa, Iowa City, IA (United States)] [and others

    1994-09-01

    Congenital heart disease is found in approximately 40% of patients with Down syndrome (DS), with endocardial cushion defects (ECDs) comprising one-third of the defects. Sixteen highly polymorphic microsatellite markers were typed in two groups (Group 1: DS with ECD, n=43, and Group 2: DS without ECD, n=52) to determine: (1) the parental origin of the extra chromosome, (2) the presence or absence of disomic homozygosity (reduced) or heterozygosity (nonreduced) of the markers along 21q, and (3) the presence or absence of recombination in the nondisjoined chromosome. The association of these three factors with the presence of ECD in DS was then determined. The origin of the nondisjoined chromosome was maternal in 86.3% of the total cases with no significant differences between groups 1 and 2. The most centromeric marker was nonreduced in 77% of the maternally-derived trisomies (indicative of a meiosis II nondisjunction) with no significant differences between groups 1 and 2. The most telomeric markers showed no differences in the number of reduced or nonreduced markers between maternally and paternally derived chromosomes or between groups 1 and 2. Recombination was significantly decreased in group 1 (28%) compared to group 2 (56%) (chi-square 7.45, p < 0.01) with similar values for both paternally and maternally-derived trisomies. Overall, recombination was present in 43.2% of the nondisjoined chromosomes which is similar to the 42.3% recombination reported in nondisjoined chromosomes in trisomy 21.

  12. Metal-Organic Frameworks (MOFs) as Sandwich Coating Cushion for Silicon Anode in Lithium Ion Batteries.

    Science.gov (United States)

    Han, Yuzhen; Qi, Pengfei; Zhou, Junwen; Feng, Xiao; Li, Siwu; Fu, Xiaotao; Zhao, Jingshu; Yu, Danni; Wang, Bo

    2015-12-09

    A novel metal-organic framework (MOF) sandwich coating method (denoted as MOF-SC) is developed for hybrid Li ion battery electrode preparation, in which the MOF films are casted on the surface of a silicon layer and sandwiched between the active silicon and the separator. The obtained electrodes show improved cycling performance. The areal capacity of the cheap and readily available microsized Si treated with MOF-SC can reach 1700 μAh cm(-2) at 265 μA cm(-2) and maintain at 850 μAh cm(-2) after 50 cycles. Beyond the above, the commercial nanosized Si treated by MOF-SC also shows greatly enhanced areal capacity and outstanding cycle stability, 600 μAh cm(-2) for 100 cycles without any apparent fading. By virtue of the novel structure prepared by the MOFs, this new MOF-SC structure serves as an efficient protection cushion for the drastic volume change of silicon during charge/discharge cycles. Furthermore, this MOF layer, with large pore volume and high surface area, can adsorb electrolyte and allow faster diffusion of Li(+) as evidenced by decreased impedance and improved rate performance.

  13. Use of pressure reducing seats and cushions in a community setting.

    Science.gov (United States)

    Collins, Fiona

    2002-01-01

    It is generally accepted that sitting for long periods of time without frequent repositioning or provision of appropriate cushions or chairs can lead to pressure ulcer development in people who are elderly, frail, immobile or neurologically impaired. When sitting, in comparison to lying, only a small surface area of the body is providing support, predominantly the buttocks and thighs, and the feet. Therefore, interface pressures are much greater in sitting than lying. Sitting for long periods of time can result in the person adopting poor posture, which in turn can lead to the development of pressure ulcers, particularly on the buttocks, sacrum, greater trochanter and heels. Assessment and provision of appropriate seating equipment for people at risk is often difficult for clinicians working in the community. This article aims to describe the problems experienced by people who sit for long periods of time, to discuss where people should go in order to obtain help with seating needs, and outline some of the potential solutions to poor seating which are available to community staff.

  14. Wear rate evaluation of a novel polycarbonate-urethane cushion form bearing for artificial hip joints.

    Science.gov (United States)

    Elsner, Jonathan J; Mezape, Yoav; Hakshur, Keren; Shemesh, Maoz; Linder-Ganz, Eran; Shterling, Avi; Eliaz, Noam

    2010-12-01

    There is growing interest in the use of compliant materials as an alternative to hard bearing materials such as polyethylene, metal and ceramics in artificial joints. Cushion form bearings based on polycarbonate-urethane (PCU) mimic the natural synovial joint more closely by promoting fluid-film lubrication. In the current study, we used a physiological simulator to evaluate the wear characteristics of a compliant PCU acetabular buffer, coupled against a cobalt-chrome femoral head. The wear rate was evaluated over 8 million cycles gravimetrically, as well as by wear particle isolation using filtration and bio-ferrography (BF). The gravimetric and BF methods showed a wear rate of 9.9-12.5mg per million cycles, whereas filtration resulted in a lower wear rate of 5.8mg per million cycles. Bio-ferrography was proven to be an effective method for the determination of wear characteristics of the PCU acetabular buffer. Specifically, it was found to be more sensitive towards the detection of wear particles compared to the conventional filtration method, and less prone to environmental fluctuations than the gravimetric method. PCU demonstrated a low particle generation rate (1-5×10⁶ particles per million cycles), with the majority (96.6%) of wear particle mass lying above the biologically active range, 0.2-10μm. Thus, PCU offers a substantial advantage over traditional bearing materials, not only in its low wear rate, but also in its osteolytic potential.

  15. 桩帽垫层对锤击沉桩的影响数值分析%Numerical Analysis of Influence of Pile Cap Cushion on Driving Pile

    Institute of Scientific and Technical Information of China (English)

    王继成; 倪占东; 柳爱; 周向阳

    2011-01-01

    Elastic pile cap cushion and hardwood cushion are simulated by ABAQUS, the famous finite element software, in order to study the influence of pile cap cushion on driving pile in this paper. It is discovered that elastic cushion can reduce the stress of the driven pile evidently during the driving process,but the capacity of reducing the pile stress of hardwood is poor. The penetration can be increased greatly with suitable thickness and stiffness of the cushion. There is certain relationship among hammering energy, thickness and stiffness of the cushion. A certain stiffness corresponds to an optimal thickness, the optimal thickness and the range of optimal thickness is enlarged with the increase of stiffness. Much better effectiveness of driving pile with thicker and suitable pile cap cushion can be obtained.%为了研究桩帽垫层对锤击沉桩效果的影响,采用有限元软件ABAQUS对弹性桩帽垫层和硬木垫层进行了模拟,发现弹性垫层在锤击过程中可显著降低桩身应力,而硬木板降低桩身应力的能力有限.采用合适厚度、刚度的垫层时,可显著增加贯人度.锤击能、垫层厚度、垫层刚度之间存在一定关系.对于某一垫层刚度,存在一最优垫层厚度,垫层刚度增加,最优垫层厚度范围也增加了.厚度较厚、刚度稍大的垫层能取得较好的沉桩效果.

  16. Retinoic Acid Signaling Is Essential for Valvulogenesis by Affecting Endocardial Cushions Formation in Zebrafish Embryos.

    Science.gov (United States)

    Li, Junbo; Yue, Yunyun; Zhao, Qingshun

    2016-02-01

    Retinoic acid (RA) plays important roles in many stages of heart morphogenesis. Zebrafish embryos treated with exogenous RA display defective atrio-ventricular canal (AVC) specification. However, whether endogenous RA signaling takes part in cardiac valve formation remains unknown. Herein, we investigated the role of RA signaling in cardiac valve development by knocking down aldh1a2, the gene encoding an enzyme that is mainly responsible for RA synthesis during early development, in zebrafish embryos. The results showed that partially knocking down aldh1a2 caused defective formation of primitive cardiac valve leaflets at 108 hpf (hour post-fertilization). Inhibiting endogenous RA signaling by 4-diethylaminobenzal-dehyde revealed that 16-26 hpf was a key time window when RA signaling affects the valvulogenesis. The aldh1a2 morphants had defective formation of endocardial cushion (EC) at 76 hpf though they had almost normal hemodynamics and cardiac chamber specification at early development. Examining the expression patterns of AVC marker genes including bmp4, bmp2b, nppa, notch1b, and has2, we found the morphants displayed abnormal development of endocardial AVC but almost normal development of myocardial AVC at 50 hpf. Being consistent with the reduced expression of notch1b in endocardial AVC, the VE-cadherin gene cdh5, the downstream gene of Notch signaling, was ectopically expressed in AVC of aldh1a2 morphants at 50 hpf, and overexpression of cdh5 greatly affected the formation of EC in the embryos at 76 hpf. Taken together, our results suggest that RA signaling plays essential roles in zebrafish cardiac valvulogenesis.

  17. A new mulinane diterpenoid from the cushion shrub Azorella compacta growing in Perú

    Science.gov (United States)

    Salgado, Francisco; Areche, Carlos; Sepúlveda, Beatriz; Simirgiotis, Mario J.; Cáceres, Fátima; Quispe, Cristina; Quispe, Lina; Cano, Teresa

    2014-01-01

    Background: Azorella compacta is a rare yellow-green compact resinous cushion shrub growing from the high Andes of southern Perú to northwestern Argentina, and which is a producer of biologically active and unique diterpenoids. Objective: This study investigated the secondary metabolites present in a Peruvian sample of Azorella compacta and the evaluation of gastroprotective activity of the isolated compounds in a gastric- induced ulcer model in mice. Material and Methods: Six secondary metabolites (diterpenoids 1-6) present in the dichloromethane (DCM) extract of A. compacta growing in Perú were isolated by a combination of Sephadex LH-20 permeation and silica gel chromatography and their chemical structures were elucidated by spectroscopic methods (NMR) and molecular modeling. The gastroprotective activity of the new compound 1 was evaluated on the HCl/EtOH-induced gastric lesion model in mice and compared to the activity showed by the known compounds. Results: A new mulinane diterpene along with five known diterpenoids have been isolated from a Peruvian sample of A. compacta and the gastroprotective results show that compound 1 is less active than the other known mulinane diterpenoids isolated. Conclusions: A. compacta growing in Perú showed the presence of the new mulinane 1, which was poorly active in the HCl/EtOH-induced gastric lesion model in mice. Indeed, the activity was lower than other diterpenoids (2-6) showing an oxygenated function at C-16 or/and C-20, which confirm the role of an oxygenated group (OH or carboxylic acid) for the gastroprotective activity of mulinane compounds. PMID:25298672

  18. Living in isolation - population structure, reproduction, and genetic variation of the endangered plant species Dianthus gratianopolitanus (Cheddar pink).

    Science.gov (United States)

    Putz, Christina M; Schmid, Christoph; Reisch, Christoph

    2015-09-01

    The endangered plant species Dianthus gratianopolitanus exhibits a highly fragmented distribution range comprising many isolated populations. Based upon this pattern of distribution, we selected a study region in Switzerland with a lower magnitude of isolation (Swiss Jura) and another study region in Germany with a higher degree of isolation (Franconian Jura). In each region, we chose ten populations to analyze population structure, reproduction, and genetic variation in a comparative approach. Therefore, we determined population density, cushion size, and cushion density to analyze population structure, investigated reproductive traits, including number of flowers, capsules, and germination rate, and analyzed amplified fragment length polymorphisms to study genetic variation. Population and cushion density were credibly higher in German than in Swiss populations, whereas reproductive traits and genetic variation within populations were similar in both study regions. However, genetic variation among populations and isolation by distance were stronger in Germany than in Switzerland. Generally, cushion size and density as well as flower and capsule production increased with population size and density, whereas genetic variation decreased with population density. In contrast to our assumptions, we observed denser populations and cushions in the region with the higher magnitude of isolation, whereas reproductive traits and genetic variation within populations were comparable in both regions. This corroborates the assumption that stronger isolation must not necessarily result in the loss of fitness and genetic variation. Furthermore, it supports our conclusion that the protection of strongly isolated populations contributes essentially to the conservation of a species' full evolutionary potential.

  19. A Comparative Study Between an Improved Novel Air-Cushion Sensor and a Wheeled Probe for Minimally Invasive Surgery

    Science.gov (United States)

    Challacombe, Benjamin; Li, Jichun; Seneviratne, Lakmal; Althoefer, Kaspar; Dasgupta, Prokar; Murphy, Declan

    2010-01-01

    Abstract Purpose We describe a comparative study between an enhanced air-cushion tactile sensor and a wheeled indentation probe. These laparoscopic tools are designed to rapidly locate soft-tissue abnormalities during minimally invasive surgery (MIS). Materials and Methods The air-cushion tactile sensor consists of an optically based sensor with a 7.8 mm sphere “floating” on a cushion of air at the tip of a shaft. The wheeled indentation probe is a 10 mm wide and 5 mm in diameter wheel mounted to a force/torque sensor. A continuous rolling indentation technique is used to pass the sensors over the soft-tissue surfaces. The variations in stiffness of the viscoelastic materials that are detected during the rolling indentations are illustrated by stiffness maps that can be used for tissue diagnosis. The probes were tested by having to detect four embedded nodules in a silicone phantom. Each probe was attached to a robotic manipulator and rolled over the silicone phantom in parallel paths. The readings of each probe collected during the process of rolling indentation were used to achieve the final results. Results The results show that both sensors reliably detected the areas of variable stiffness by accurately identifying the location of each nodule. These are illustrated in the form of two three-dimensional spatiomechanical maps. Conclusions These probes have the potential to be used in MIS because they could provide surgeons with information on the mechanical properties of soft tissue, consequently enhancing the reduction in haptic feedback. PMID:20624084

  20. Subjective valuation of cushioning in a human drop landing task as quantified by trade-offs in mechanical work.

    Science.gov (United States)

    Skinner, Nathaniel E; Zelik, Karl E; Kuo, Arthur D

    2015-07-16

    Humans can perform motor tasks in a variety of ways, yet often favor a particular strategy. Some factors governing the preferred strategy may be objective and quantifiable, (e.g. metabolic energy or mechanical work) while others may be more subjective and less measurable, (e.g. discomfort, pain, or mental effort). Subjectivity can make it challenging to explain or predict preferred movement strategies. We propose that subjective factors might nevertheless be characterized indirectly by their trade-offs against more objective measures such as work. Here we investigated whether subjective costs that influence human movement during drop landings could be indirectly assessed by quantifying mechanical work performed. When landing on rigid ground, humans typically absorb much of the collision actively by bending their knees, perhaps to avoid the discomfort of stiff-legged landings. We measured how work performed by healthy adults (N=8) changed as a function of surface cushioning for drop landings (fixed at about 0.4m) onto varying amounts of foam. Landing on more foam dissipated more energy passively in the surface, thus reducing the net dissipation required of subjects, due to relatively fixed landing energy. However, subjects actually performed even less work in the dissipative collision, as well as in the subsequent active, positive work to return to upright stance (approximately linear decrease of about 1.52 J per 1 cm of foam thickness). As foam thickness increased, there was also a corresponding reduction in center-of-mass vertical displacement after initial impact by up to 43%. Humans appear to subjectively value cushioning, revealed by the extra work they perform landing without it. Cushioning is thus worth more than the energy it dissipates, in an amount that indicates the subjective discomfort of stiff landings.

  1. Advancing a smart air cushion system for preventing pressure ulcers using projection Moiré for large deformation measurements

    Science.gov (United States)

    Cheng, Sheng-Lin; Tsai, Tsung-Heng; Lee, Carina Jean-Tien; Hsu, Yu-Hsiang; Lee, Chih-Kung

    2016-03-01

    A pressure ulcer is one of the most important concerns for wheelchair bound patients with spinal cord injuries. A pressure ulcer is a localized injury near the buttocks that bear ischial tuberosity oppression over a long period of time. Due to elevated compression to blood vessels, the surrounding tissues suffer from a lack of oxygen and nutrition. The ulcers eventually lead to skin damage followed by tissue necrosis. The current medical strategy is to minimize the occurrence of pressure ulcers by regularly helping patients change their posture. However, these methods do not always work effectively or well. As a solution to fundamentally prevent pressure ulcers, a smart air cushion system was developed to detect and control pressure actively. The air cushion works by automatically adjusting a patient's sitting posture to effectively relieve the buttock pressure. To analyze the correlation between the dynamic pressure profiles of an air cell with a patient's weight, a projection Moiré system was adopted to measure the deformation of an air cell and its associated stress distribution. Combining a full-field deformation imaging with air pressure measured within an air cell, the patient's weight and the stress distribution can be simultaneously obtained. By integrating a full-field optical metrology with a time varying pressure sensor output coupled with different active air control algorithms for various designs, we can tailor the ratio of the air cells. Our preliminary data suggests that this newly developed smart air cushion has the potential to selectively reduce localized compression on the tissues at the buttocks. Furthermore, it can take a patient's weight which is an additional benefit so that medical personnel can reference it to prescribe the correct drug dosages.

  2. Digital Cushion Fatty Acid Composition and Lipid Metabolism Gene Network Expression in Holstein Dairy Cows Fed a High-Energy Diet.

    Directory of Open Access Journals (Sweden)

    Zeeshan Muhammad Iqbal

    Full Text Available The hoof digital cushion is a complex structure composed of adipose tissue beneath the distal phalanx, i.e. axial, middle and abaxial fat pad. The major role of these fat depots is dampening compression of the corium underneath the cushion. The study aimed to determine expression of target genes and fatty acid profiles in the hoof of non-pregnant dry Holstein cows fed low (CON or high-energy (OVE diets. The middle fat pad of the hoof digital cushion was collected soon after slaughter. Despite the lack of effect on expression of the transcription regulators SREBF1 and PPARG, the expression of the lipogenic enzymes ACACA, FASN, SCD, and DGAT2 was upregulated with OVE. Along with the upregulation of G6PD and IDH1, important for NADPH synthesis during lipogenesis, and the basal glucose transporter SLC2A1, these data indicated a pro-lipogenic response in the digital cushion with OVE. The expression of the lipid droplet-associated protein PLIN2 was upregulated while expression of lipolytic enzymes (ATGL, ABDH5, and LIPE only tended to be upregulated with OVE. Therefore, OVE induced lipogenesis, lipid droplet formation, and lipolysis, albeit to different extents. Although concentration of monounsaturated fatty acids (MUFA did not differ, among the polyunsaturated fatty acids (PUFA, the concentration of 20:5n3 was lower with OVE. Among the saturated fatty acids, 20:0 concentration was greater with OVE. Although data indicated that the hoof digital cushion metabolic transcriptome is responsive to higher-energy diets, this did not translate into marked differences in the fatty acid composition. The decrease in concentration of PUFA, which could contribute to synthesis of inflammatory molecules, in OVE-fed cows indicated that feeding higher-energy diets might be detrimental for the mediation of inflammation in digital cushion. This effect could be further exacerbated by physiologic and endocrine changes during the peripartal period that favor inflammation.

  3. ENGINEERING DESIGN: EICOSANE MICROCAPSULES SYNTHESIS AND APPLICATION IN POLYURETHANE FOAMS AIMING TO DIMINISH WHEELCHAIR CUSHION EFFECT ON SKIN TEMPERATURE

    Directory of Open Access Journals (Sweden)

    ELISA M. BERETTA

    2016-12-01

    Full Text Available Thermal comfort of wheelchairs still requires improvements, since users remain on the chair for as long as 12 h a day. Increased sweating makes the skin more susceptible to colonization by fungi and bacteria, and may cause pressure ulcers. In this sense, the microencapsulation of Phase-Change Materials (PCMs may help to enhance wheelchair cushion comfort by regulating heat exchange. This study describes the production of PCM microcapsules and their application in flexible polyurethane foams after expansion, and assesses improvements in heat exchange. Microcapsules with eicosane core coated with melamine-formaldehyde were produced. Eicosane is a thermoregulation agent whose phase-change temperature is near that of the human body’s. Microcapsules were characterized by thermogravimetric analysis, differential scanning calorimetry, scanning electron microscopy, and Fourier transform infrared spectroscopy. Then, microcapsules were applied on polyurethane foams by vacuum filtration and high-pressure air gun. Samples were exposed to a heat source and analysed by infrared thermography. The results indicate that thermal load increased in samples treated with microcapsules, especially by pressure air gun, and show that it is possible to enhance thermal comfort in wheelchair seats. Thereby, this study contributes to enhance quality of life for wheelchair users, focusing on thermal comfort provided by cushion seats made from PU foam.

  4. Determination of the volatile fraction of phosphorus flame retardants in cushioning foam of upholstered furniture: towards respiratory exposure assessment.

    Science.gov (United States)

    Ghislain, Mylène; Beigbeder, Joana; Dumazert, Loïc; Lopez-Cuesta, José-Marie; Lounis, Mohammed; Leconte, Stéphane; Desauziers, Valérie

    2016-10-01

    The purpose of this paper was to highlight potential exposure in indoor air to phosphorus flame retardants (PFRs) due to their use in upholstered furniture. For that, an analytical method of PFRs by headspace coupled to solid-phase micro-extraction (HS-SPME) was developed on cushioning foams in order to determine the PFRs' volatile fraction in the material. Tests on model foams proved the feasibility of the method. The average repeatability (RSD) is 6.3 % and the limits of detection range from 0.33 to 1.29 μg g(-1) of foam, depending on the PFRs. Results showed that some PFRs can actually be emitted in air, leading to a potential risk of exposure by inhalation. The volatile fraction can be high (up to 98 % of the total PFRs amount) and depends on the physicochemical properties of flame retardants, on the textural characteristics of the materials and on the temperature. The methodology developed for cushioning foams could be further applied to other types of materials and can be used to rate them according to their potential releases of phosphorus flame retardants.

  5. Influence of Cushioning Variables in the Workplace and in the Family on the Probability of Suffering Stress.

    Science.gov (United States)

    Gonzalo, David Cárdenas

    2016-09-01

    Stress at work and in the family is a very common issue in our society that generates many health-related problems. During recent years, numerous studies have sought to define the term stress, raising many contradictions that various authors have studied. Other authors have attempted to establish some criteria, in subjective and not very quantitative ways, in an attempt to reduce and even to eliminate stressors and their effects at work and in the family context. The purpose of this study was to quantify so-called cushioning variables, such as control, social support, home/work life conciliation, and even sports and leisure activities, with the purpose of, as much as possible, reducing the negative effects of stress, which seriously affects the health of workers. The study employs data from the Fifth European Working Conditions Survey, in which nearly 44,000 interviewees from 34 countries in the European Union participated. We constructed a probabilistic model based on a Bayesian network, using variables from both the workplace and the family, the aforementioned cushioning variables, as well as the variable stress. If action is taken on the above variables, then the probabilities of suffering high levels of stress may be reduced. Such action may improve the quality of life of people at work and in the family.

  6. Novel wireless health monitor with acupuncture bio-potentials obtained by using a replaceable salt-water-wetted foam-rubber cushions on RFID-tag.

    Science.gov (United States)

    Lin, Jium-Ming; Lu, Hung-Han; Lin, Cheng-Hung

    2014-01-01

    This paper proposes a bio-potential measurement apparatus including a wireless device for transmitting acupuncture bio-potential information to a remote control station for health conditions analysis and monitor. The key technology of this system is to make replaceable foam-rubber cushions, double-side conducting tapes, chip and antenna on the radio frequency identification (RFID) tag. The foam-rubber cushions can be wetted with salt-water and contact with the acupuncture points to reduce contact resistance. Besides, the double-side conducting tapes are applied to fix foam-rubber cushions. Thus, one can peel the used cushions or tapes away and supply new ones quickly. Since the tag is a flexible plastic substrate, it is easy to deploy on the skin. Besides, the amplifier made by CMOS technology on RFID chip could amplify the signals to improve S/N ratio and impedance matching. Thus, cloud server can wirelessly monitor the health conditions. An example shows that the proposed system can be used as a wireless health condition monitor, the numerical method and the criteria are given to analyze eleven bio-potentials for the important acupunctures of eleven meridians on a person's hands and legs. Then a professional doctor can know the performance of an individual and the cross-linking effects of the organs.

  7. Finding the optimal setting of inflated air pressure for a multi-cell air cushion for wheelchair patients with spinal cord injury.

    Directory of Open Access Journals (Sweden)

    Hamanami K

    2004-02-01

    Full Text Available Pressure distribution patterns of the seating interface on the multi-cell air cushion (ROHO High Profile of 36 adults with spinal cord injury (SCI (Neurological level Th3 -L1 were measured at different air pressure levels by a pressure mat measurement system. Stress distribution relative to the inflated air pressure in the air cushion on the patients' wheelchairs was analyzed to determine the appropriate inflated air pressure of the cushion for patients. The maximum pressure points in all subjects were at the areas of the ischial tuberosities (82 to 347 mmHg. The optimal reduction in interface pressure at the ischial tuberosities was obtained just before bottoming out. The cushion air pressure at that point was between 17 and 42 mmHg, and correlated well to body weight (r = 0.495, P = 0.0021. In contrast, the maximum pressure levels did not correlate to body weight or the Body Mass Index (BMI. Pressure at the ischial area could be reduced, but not eliminated, by adjusting the air pressure. The maximum pressure levels seemed to be related to the shape of the buttocks, especially the amount of soft tissue, and exceeded the defined threshold for pressure ulcers (> 80 g/cm2.

  8. 生物质缓冲包装材料制备及性能实验研究%Preparation and properties of biomass cushion packaging material

    Institute of Scientific and Technical Information of China (English)

    李刚; 李方义; 管凯凯; 刘鹏; 吕禹; 贾秀杰; 李剑峰

    2013-01-01

    To solve the environmental pollution caused by the non-degradable waste of plastic packaging materials,the biomass cushion packaging materials with different ingredients have been synthesized,which are made up of straw fiber and starch as the main raw materials.The orthogonal experiment method is used to study the impact of the mass ratio of fiber and starch,the content of plasticizer,active agent and blowing agent on the compressive strength of biomass cushion packaging material.The results were as follows:the influence order of various factors on compressive strength was:plasticizer >the mass ratio of fiber and starch> foaming agent>active agent.When the contents of the plasticizer,foaming agent,active agent are respectively 12%,0.1%,0.3% with the mass ratio of fiber and starch being 2:5,the compressive strength can reach 0.94MPa.Through research on the impacts of plasticizer content and mass ratio of fiber and starch on the cushion performance,the cushion coefficient of the material decreases firstly and increases subsequently with the two factors rising.When the plasticizer content was 12% and the mass ratio of fiber and starch was 2:5,the smallest cushion coefficient and the best cushion performance of the material are obtained.Compared the cushion and rebound performance with EPS (expanded polystyrene),EPE (expanded polyethylene) and other packaging materials,it indicates that the biomass cushion packaging material can replace the cushion packaging materials such as EPS and EPE.%为解决不可降解的废弃塑料类包装材料对环境造成的污染,以稻草纤维、淀粉为主要原料制备了生物质缓冲包装材料,采用正交实验方法研究了生物质缓冲包装材料纤维与淀粉质量比、塑化剂、活性剂和发泡剂含量等对材料抗压强度的影响,结果表明,各因素对材料抗压强度影响的主次顺序为塑化剂>纤维与淀粉质量比>发泡剂>活性剂.塑化剂含量为12%、

  9. Principle Analysis & Numerical Simulation to New Type NC Hydraulic Cushion System%新型数控液压垫系统原理分析及数字仿真

    Institute of Scientific and Technical Information of China (English)

    蔡喜; 陈刚

    2016-01-01

    The paper introduces a new type NC hydraulic cushion system. The numerical simulation to the cushion system was performed with matlab simulink to provide the basis for the optimization. The cushion system with high stability and dynamic response meets the requirement of customers in actual application and replaces abroad branded NC hydraulic cushion systems.%介绍一种新型数控液压垫系统,利用matlab simulink对该液压垫系统做数字仿真分析,为优化系统参数提供依据。该系统具有很好的稳定性和动态响应,能够满足用户实际使用需要,可以替代国外品牌的数控液压垫。

  10. Rain erosion of wind turbine blade coatings using discrete water jets: Effects of water cushioning, substrate geometry, impact distance, and coating properties

    DEFF Research Database (Denmark)

    Zhang, Shizhong; Dam-Johansen, Kim; Bernad, Pablo L.

    2015-01-01

    Rapid and reliable rain erosion screening of blade coatings for wind turbines is a strong need in the coatings industry. One possibility in this direction is the use of discrete water jets, where so-called jet slugs are impacted on a coating surface. Previous investigations have mapped...... the influence of water jet slug velocity and impact frequency. In the present work, the effects on coating erosion of water cushioning, substrate curvature, and water nozzle-coating distance were explored. The investigations showed that in some cases water cushioning (the presence of a liquid film...... on the coating surface prior to impact) influences the erosion. Contrary to this, substrate curvature and the water nozzle-coating distance (coatings, including tensile strength, flexibility...

  11. Study of Cushion Airbag Material for Precision Airdrop%精确空投缓冲气囊材料研究

    Institute of Scientific and Technical Information of China (English)

    黄刚; 李良春

    2011-01-01

    介绍了精确空投着陆缓冲的作用原理以及对气囊材料的要求,分析了聚酰胺、聚酯纤维2种气囊织物材料和氯丁橡胶、硅酮2种涂层材料的结构性能及发展,总结了当前主要的新材料技术,提出了着陆缓冲气囊材料的发展趋势.%The cushion principle of precision airdrop landing and its requirements for airbag material were introduced. The structure, performance, and development of two airbag fabric materials polyamide (PA) and polyester and two coat materials neoprene and silicone were analyzed. Several main new material technologies were summarized and the development trend of the landing cushion airbag material technology was put forward.

  12. 混凝土重力坝气幕隔震效果研究%Air-cushion isolation effects on a concrete gravity dam

    Institute of Scientific and Technical Information of China (English)

    陈江; 熊峰

    2014-01-01

    The gas-liquid-solid tri-phase coupling numerical model for a concrete gravity dam based on air-cushion isolation control was presented here.In this model,the cracking behavior of dam concrete was considered.The radiation damping effect of the truncated boundary of the dam foundation was simulated with a visco-elastic artificial boundary condition.The 3D nonlinear simulation of air-cushion isolation effects on the concrete gravity dam was conducted for the first time.It was shown that the air-cushion reduces the hydrodynamic pressure and the acceleration response of the dam body effectively,so the cracking range of the dam body decreases;with increase in the thickness of the air-cushion,the reduction of hydrodynamic pressure and the acceleration response is more significant;the rate of reduction level decreases progressively;compared with the uniform-thickness air-cushion,the variable-thickness air-cushion can improve the utilization ratio and develop the air-cushion isolation effects more effectively.In the various cases here,the maximum hydrodynamic pressure is reduced by 50% approximately,the maximum dam peak acceleration is reduced by more than 30% with the variable-thickness air-cushion.%基于气幕隔震控制的气-液-固三相耦合数值模型,在该模型中考虑了坝体混凝土的开裂行为,采用黏弹性人工边界模拟坝基截断边界的辐射阻尼效应,首次完成了混凝土重力坝气幕隔震效果的三维非线性数值模拟。结果表明:气幕可以有效降低坝体上游面的动水压力及坝体加速度反应,从而减小坝体的开裂范围。随着气幕厚度的增大,动水压力和加速度削减越多,削减幅度的提高率递减。采用变厚度气幕能提高利用率,更有效地发挥气幕的隔震效果,该工况,变厚度气幕对混凝土重力坝动水压力极值的削减幅度约为50%,坝顶加速度峰值的消减幅度超过30%。

  13. The contribution made by an armchair with integral pressure-reducing cushion in the prevention of pressure sore incidence in the elderly, acutely ill patient.

    Science.gov (United States)

    Collins, F

    1999-10-01

    The paper describes a clinical controlled trial of an armchair with integral pressure-reducing cushion, which took place on two elderly acute medical wards in a district general hospital. The aim of the study was to evaluate whether the armchair would have an impact on reducing the occurrence of pressure sores. All patients were provided with a mattress or overlay in accordance with the hospital policy on mattress provision following a Waterlow risk assessment. Patients on ward A were provided with an armchair with integral pressure-reducing cushion, whilst patients on ward B continued to use their existing bedside armchair. Nominal data were collected on all pressure sores in patients who were not bedridden. Ward A had a significantly lower incidence of hospital-acquired pressure sores compared to ward B, and non-hospital-acquired pressure sores on this ward showed more improvement than those on ward B.

  14. Mmp15 is a direct target of Snai1 during endothelial to mesenchymal transformation and endocardial cushion development.

    Science.gov (United States)

    Tao, Ge; Levay, Agata K; Gridley, Thomas; Lincoln, Joy

    2011-11-15

    Cardiac valves originate from endocardial cushions (EC) formed by endothelial-to-mesenchymal transformation (EMT) during embryogenesis. The zinc-finger transcription factor Snai1 has previously been reported to be important for EMT during organogenesis, yet its role in early valve development has not been directly examined. In this study we show that Snai1 is highly expressed in endothelial, and newly transformed mesenchyme cells during EC development. Mice with targeted snai1 knockdown display hypocellular ECs at E10.5 associated with decreased expression of mesenchyme cell markers and downregulation of the matrix metalloproteinase (mmp) family member, mmp15. Snai1 overexpression studies in atrioventricular canal collagen I gel explants indicate that Snai1 is sufficient to promote mmp15 expression, cell transformation, and mesenchymal cell migration and invasion. However, treatment with the catalytically active form of MMP15 promotes cell motility, and not transformation. Further, we show that Snai1-mediated cell migration requires MMP activity, and caMMP15 treatment rescues attenuated migration defects observed in murine ECs following snai1 knockdown. Together, findings from this study reveal previously unappreciated mechanisms of Snai1 for the direct regulation of MMPs during EC development.

  15. 压力控制型防压疮垫的减压性能测试分析%Evaluation of Pressure Reduction of Pressure-control Ulcer Cushion

    Institute of Scientific and Technical Information of China (English)

    云晓; 郭欢

    2015-01-01

    Objective To evaluate the decompression performance of anti pressure ulcer cushions with different materials and structures. Methods The common cotton cushion, sponge cushion, 3D fabric cushion, and upper 3D fabric and lower sponge cushion were analyzed by XSensor pressure sensor testing system. The pressure distribution, the pressure peak and the average pressure were analyzed to compare the decompression performance and the comfortable capability. Results and Conclusion The upper 3D fabric and lower sponge cushion can en-sure the decompression performance with excellent permeability. Both decompression and air comfort permeability should be the future di-rection of ulcer cushions research and production.%目的:测试分析几种不同材质结构的防压疮垫的减压性能。方法使用XSensor压力传感器测试系统,测试试验者使用普通棉质床垫、海绵防压疮垫、3D织物防压疮垫和上层3D织物下层海绵防压疮垫4种防压疮垫的压力情况。从压力分布图、压力峰值、压力平均值几个角度进行评价,对比各种防压疮垫减压性能及使用舒适性。结果和结论上层3D织物下层海绵防压疮垫的组合方式既可保证减压性能效果又具备优良的透气性。兼顾减压及透气舒适性应是今后防压疮产品的生产研究方向。

  16. Mycorrhiza-plant colonization patterns on a subalpine glacier forefront as a model system of primary succession.

    Science.gov (United States)

    Cázares, Efrén; Trappe, James M; Jumpponen, Ari

    2005-09-01

    Lyman glacier in the North Cascades Mountains of Washington has a subalpine forefront characterized by a well-developed terminal moraine, inconspicuous successional moraines, fluting, and outwash. These deposits were depleted of symbiotic fungi when first exposed but colonized by them over time after exposure. Four major groups of plant species in this system are (1) mycorrhiza-independent or facultative mycotrophic, (2) dependent on arbuscular mycorrhizae (AM) (3) dependent on ericoid mycorrhiza (ERM) or ectomycorrhizae (EM), and (4) colonized by dark-septate (DS) endophytes. We hypothesized that availability of mycorrhizal propagules was related to the success of mycorrhiza-dependent plants in colonizing new substrates in naturally evolved ecosystems. To test this hypothesis roots samples of 66 plant species were examined for mycorrhizal colonization. The plants were sampled from communities at increasing distances from the glacier terminus to compare the newest communities with successively older ones. Long established, secondary successional dry meadow communities adjacent to the glacier forefront, and nearby high alpine communities were sampled for comparison. DS were common on most plant species on the forefront. Nonmycorrhizal plants predominated in the earlier successional sites, whereas the proportion of mycorrhizal plants generally increased with age of community. AM were present, mostly at low levels, and nearly absent in two sites of the forefront. ERM were present in all species of Ericaceae sampled, and EM in all species of Pinaceae and Salicaceae. Roots of plants in the long established meadow and heath communities adjacent to the forefront and the high alpine community all had one or another of the colonization types, with DS and AM predominating.

  17. Site Monitoring and Analysis on Differential Settlement of Subgrade Adjusted with Gravel Cushion%碎石垫层调整路基差异沉降的现场监测与分析

    Institute of Scientific and Technical Information of China (English)

    叶勇

    2014-01-01

    我国对水泥混凝土路面下碎石垫层的研究很不充分,对碎石垫层调整路基差异沉降的机理研究较少,缺乏对碎石垫层调整路基差异沉降的现场监测研究。依托广东省阳江~阳春高速公路进行了碎石垫层调整路基差异沉降的现场监测研究,研究成果对于完善水泥路面碎石垫层的设计方法具有重要作用。%As there is not sufficient researches on the gravel cushion under cement concrete pavement in our country, there is less researches on mechanism of subgrade differential settlement adjusted by gravel cushion,there is also short-age of researches on on-site monitoring for subgrade differential settlement adjusted by gravel cushion.In this article, being based on practice of Yangjiang-Yangchun Expressway in Guangdong Province,study on on-site monitoring for subgrade differential settlement adjusted by gravel cushion has been carried out,and the study findings have an impor-tant role on the design method improvement for gravel cushion for cement pavement.

  18. Effects of Micronized Fibers on the Cushion Properties of Foam Buffer Package Materials

    Directory of Open Access Journals (Sweden)

    Chongxing Huang

    2014-08-01

    Full Text Available Foam buffer package materials composed of plant fibers have been a focus of research in recent years because of their environmentally beneficial ability to become fully disintegrated. In this study, bleached bagasse pulp was micronized using a PFI mill, and foam buffer materials were prepared using the micronized fiber. The effects of the beating degree of micronized fibers on the dimensional stability, moisture absorption, static compression, and dynamic compression characteristics were discussed. Results showed that, in both the static and the dynamic compression experiments, the buffer properties improved with an increasing beating degree. The buffer materials made of highly micronized fiber were stronger under pressure and impact. Specifically, the highly micronized fiber’s ability to absorb energy curing impact was improved, demonstrating that it can support a higher compression and impacting load in a certain deformation scope. However, during the drying process, the dimensional stability of the samples also declined with an increasing beating degree. The moisture absorption of the samples improved when the beating degree was increased.

  19. Anal cushion lifting method is a novel radical management strategy for hemorrhoids that does not involve excision or cause postoperative anal complications

    Institute of Scientific and Technical Information of China (English)

    Gentaro; Ishiyama; Toshihiko; Nishidate; Yuji; Ishiyama; Akihiko; Nishio; Ken; Tarumi; Maiko; Kawamura; Kenji; Okita; Toru; Mizuguchi; Mineko; Fujimiya; Koichi; Hirata

    2015-01-01

    AIM: To describe the anal cushion lifting(ACL) method with preliminary clinical results. METHODS: Between January to September 2007, 127 patients who received ACL method for hemorrhoid was investigated with informed consent. In this study, three surgeons who specialized in anorectal surgery performed the procedures. Patients with grade two or more severe hemorrhoids according to Goligher’s classification were considered to be indicated for surgery. The patients were given the choice to undergo either the ACL method or theligation and excision method. ACL method is an original technique for managing hemorrhoids without excision. After dissecting the anal cushion from the internal sphincter muscle, the anal cushion was lifted to oral side and ligated at the proper position. Clinical characteristics and outcomes of patients were recorded including complications after surgery. RESULTS: A total of 127 patients were enrolled. Their median age was 42(19-84) years, and 74.8% were female. In addition, more than 99% of the patients had grade 3 or worse hemorrhoids. The median followup period was 26(0-88) mo, and the median operative time was 15(4-30) min. After surgery, analgesics were used for a median period of three days(0-21). Pain control was achieved using extra-oral analgesic drugs, although some patients required intravenous injections of analgesic drugs. The median duration of the patients’ postoperative hospital stay was 7(2-13) d. A total of 10 complications(7.9%) occurred. Bleeding was observed in one patient and was successfully controlled with manual compression. Urinary retention occurred in 6 patients, but it disappeared spontaneously in all cases. Recurrent hemorrhoids developed in 3 patients after 36, 47, and 61 mo, respectively. No anal stenosis or persistent anal pain occurred. CONCLUSION: We consider that the ACL method might be better than all other current methods for managing hemorrhoids.

  20. Settlement Calculation and Analysis of Replacement Cushion Foundation in Angola%安哥拉换填垫层地基的沉降计算分析

    Institute of Scientific and Technical Information of China (English)

    彭友君; 杨铮; 彭博

    2015-01-01

    安哥拉浅部棕红色砂Quelo地层具有湿陷性特征,采用换填垫层进行地基处理后,沉降计算是岩土工程研究最重要的课题。分别对换填垫层、压实地基、天然地基浸水后,通过勘探和原位测试给出了土的物理力学指标,建立锥头阻力与地基反力系数的回归方程,完善随深度变化的沉降计算参数,按照英国标准规定的公式和算例进行沉降计算,假定条形基础与换填垫层组成整体基础并对其可靠性进行验算,从而简化了沉降计算方法,将沉降计算结果与实测沉降量对比分析后,说明沉降计算结果可信并满足设计要求,实体楼的浸水试验也得到了印证,安哥拉砂土地基采用换填垫层法进行地基处理是合理的。%The shallow red brown sand Quelo stratum in Angola has the characteristic of collapsibility, and the most important subject of geotechnical engineering research is settlement calculation after foundation treatment by adopting replacement cushion. After immersion of the replacement cushion, compacted foundation and natural foundation, the physical and mechanical indicators of the soil are given through exploration and in⁃situ test, the regression equation of the cone resistance and foundation reaction force coefficient is established, and the settlement calculation parameters changed with depth are perfected. Settlement calculation is conducted according to the formula and example specified in British Standards. It is assumed that the strip foundation and the replacement cushion constitute the overall foundation, and reliability is checked, so as to simplify the settlement calculation method. Through contrastive analysis of the settlement calculation results and measured settlement amount, it indicates that the settlement calculation results are reliable, and can meet design requirements. The water immersion test of the entity building is also proved, and it is reasonable to

  1. Application of UGNX NC Programming Technology in Lebuss Drum Cushion Block's Processing%UGNX数控编程技术在Lebus卷筒导向垫块加工中的应用

    Institute of Scientific and Technical Information of China (English)

    邓玉聪; 徐长生

    2011-01-01

    针对Lebuss卷筒导向垫块在设计和制造上存在的困难,建立卷筒和垫块的三维模型,利用UG的数控加工自动编程功能生成垫块的数控加工程序来对垫块进行精确加工.%Based on the difficulties in designing and manufacturing of lebuss drum cushion block, 3D models of drum and cushion block are established directly,and using UG CNC automatic programming function the NC machining process of cushion block is generated to process it precisely.This pape's method has Practical application value on Lebuss drum design and manufacturing.

  2. Effect of the Research Advances of Anal Cushions on the Treatment of Hemorrhoids%肛垫的研究进展对痔治疗的影响

    Institute of Scientific and Technical Information of China (English)

    高枫

    2003-01-01

    @@ 肛垫(anal cushions,vascular cushions)是一个解剖学概念,最早见于Thomson 1975年发表的论文(The nature of haemorrhoids),也称肛门海绵体(corpus cavernosum recti),是指齿状线上方宽约1.5 cm呈环状增厚的直肠柱区,借"Y"形沟分割成右前、右后和左中三块,由血管、平滑肌(Treitz肌)、弹力纤维和结缔组织所构成.肛垫早在胚胎期就已存在,属于人体正常结构的一部分.与直肠粘膜、粘膜下层、肌层比较,主要表现为肛管内局部增厚的粘膜下组织.

  3. 3-D simulation of transient flow patterns in a corridor-shaped air-cushion surge chamber based on computational fluid dynamics

    Institute of Scientific and Technical Information of China (English)

    XIA Lin-sheng; CHENG Yong-guang; ZHOU Da-qing

    2013-01-01

    The 3-D characteristics of the water-air flow patterns in a corridor-shaped air-cushion surge chamber during hydraulic transients need to be considered in the shape optimization.To verify the reliability of the water-air two-phase model,namely,the volume of fluid model,the process of charging water into a closed air chamber is successfully simulated.Using the model,the 3-D flow characteristics under the load rejection and acceptance conditions within the air-cushion surge chamber of a specific hydropower station are studied.The flee surface waves,the flow patterns,and the pressure changes during the surge wave process are analyzed in detail.The longitudinal flow of water in the long corridor-shaped surge chamber is similar to the open channel flow with respect to the wave propagation,reflection and superposition characteristics.The lumped parameters of the 3-D numerical simulation agree with the results of a 1-D calculation of hydraulic transients in the whole water conveying system,which validates the 3-D method.The 3-D flow structures obtained can be applied to the shape optimization of the chamber.

  4. Numerical Simulation and Analysis of Migration Law of Gas Mixture Using Carbon Dioxide as Cushion Gas in Underground Gas Storage Reservoir

    Institute of Scientific and Technical Information of China (English)

    ChuanKai Niu; YuFei Tan

    2014-01-01

    One of the major technical challenges in using carbon dioxide ( CO2 ) as part of the cushion gas of the underground gas storage reservoir ( UGSR) is the mixture of CO2 and natural gas. To decrease the mixing extent and manage the migration of the mixed zone, an understanding of the mechanism of CO2 and natural gas mixing and the diffusion of the mixed gas in aquifer is necessary. In this paper, a numerical model based on the three dimensional gas-water two-phase flow theory and gas diffusion theory is developed to understand this mechanism. This model is validated by the actual operational data in Dazhangtuo UGSR in Tianjin City, China. Using the validated model, the mixed characteristic of CO2 and natural gas and the migration mechanism of the mixed zone in an underground porous reservoir is further studied. Particularly, the impacts of the following factors on the migration mechanism are studied:the ratio of CO2 injection, the reservoir porosity and the initial operating pressure. Based on the results, the optimal CO2 injection ratio and an optimal control strategy to manage the migration of the mixed zone are obtained. These results provide technical guides for using CO2 as cushion gas for UGSR in real projects.

  5. Endocardial cushion defect

    Science.gov (United States)

    ... known as cyanosis (the lips may also be blue) Feeding difficulties Failure to gain weight and grow ... the child is an adult. These include heart rhythm problems and a leaky mitral valve. Children with ...

  6. 土工布加筋垫层对路基变形和稳定的影响%Effect of the geotextile-reinforced sand cushion on the deformation and stability of the foundation under a embankment

    Institute of Scientific and Technical Information of China (English)

    翁升; 马时冬

    2001-01-01

    某高速公路高填方路堤下的深厚软基,采用以塑料板排水为主,配合机织土工布加筋砂垫层进行了软基处理.在对有加筋砂垫层和无加筋砂垫层的软基变形性状进行比较的基础上,评价了加筋砂垫层的作用及效果.还通过计算,分析了机织土工布的预应变对路基稳定性的影响,从而说明施工加筋砂垫层时,对加筋材料施加预应变的重要性.% The soft foundation under a freeway compacted by high fill was treated mainly by drainage with plastic plates cooperated by woven geotextile-reinforced sand cushion. Based on the comparison of the deformation behavior of soft foundation of both reinforced sand cushion and ordinary sand cushion,the role and effect of the reinforced sand cushion were evaluated. At last,the effect of the prestrained geotextiles on the stability of the embankment was analyzed through calculation,thus the importance was shown of the prestrain in construction.

  7. Unexpected response of high Alpine Lake waters to climate warming.

    Science.gov (United States)

    Thies, Hansjörg; Nickus, Ulrike; Mair, Volkmar; Tessadri, Richard; Tait, Danilo; Thaler, Bertha; Psenner, Roland

    2007-11-01

    Over the past two decades, we have observed a substantial rise in solute concentration at two remote high mountain lakes in catchments of metamorphic rocks in the European Alps. At Rasass See, the electrical conductivity increased 18-fold. Unexpectedly high nickel concentrations at Rasass See, which exceeded the limit in drinking water by more than 1 order of magnitude, cannot be related to catchment geology. We attribute these changes in lake water quality to solute release from the ice of an active rock glacier in the catchment as a response to climate warming. Similar processes occurred at the higher elevation lake Schwarzsee ob Sölden, where electrical conductivity has risen 3-fold during the past two decades.

  8. Air cushioned landing craft (LCAC) based ship to shore movement simulation: A decision aid for the amphibious commander. A (SMMAT) application

    Science.gov (United States)

    Kearns, Edward P., III

    1994-09-01

    Amphibious forces are the enabling force of choice to globally project rapid and sustainable combat power in the littoral. Whether delivering supplies and equipment for military operations or for humanitarian or disaster relief, the air cushioned landing craft (LCAC) is the primary surface ship-to-shore movement craft. The time needed to transfer the forces ashore may be critical to operational success and is an important planning consideration. Many factors complicate accurate prediction of this time. Even so, various commanders must use the best available information, given mission priorities and resource and capability limitations, to make numerous tradeoff decisions in planning and executing the movement of forces. A simulation toolbox, the simulated mobility modeling and analysis toolbox (SMMAT), is introduced, and a robust LCAC ship-to-shore simulation model is developed as an extension to SMMAT. This model provides the commander a prediction and tradeoff analysis tool for planning and executing the projection of power ashore.

  9. 凉液垫在手术体位摆放中的应用%Application of cool liquid cushion in operative position placement

    Institute of Scientific and Technical Information of China (English)

    李雪清; 左育涛; 刘燕梅; 刘金秀

    2015-01-01

    Objective:To probe into the application effect of cool liquid cushion in the placement of operation po-sition.Methods:Each 60 cases of patients were selected whose surgical positions in operating room in our hospi-tal were respectively supine position,lateral position,lithotomy position,prone position and the placed time more than 4 hours,a total of 240 cases.They were randomly divided into control group and experimental group, 120 cases in each.The patients in control group were treated by routine methods to put the operation position, and the conventional cushion protection was given in compressed sponge.In experimental group,different speci-fications of cool liquid cushion was placed in pressure areas to protect,then to compare the pressure ulcer condi-tions and required physiological bending in posture compliance between two groups of patients.Results:The in-cidence of pressure sores in experimental group patients was lower than that in control group,the compliance rate of physiological curve required for position was higher than that in control group,and there was statistically significant difference (P<0.05).Conclusion:The cool liquid cushion applied for protecting pressured parts in position placement of operation patients can reded the incidence of pressure sore and increase the compliance rate of patient’s posture physiology bending and improve patients’comfort.%[目的]探讨凉液垫在手术体位摆放中的应用效果。[方法]选取在我院手术室手术体位分别是仰卧位、侧卧位、截石位、俯卧位且摆放时间超过4 h的病人各60例,共240例,随机分为对照组和试验组各120例。对照组按常规方法摆放手术体位,受压处常规给予海绵垫保护;试验组应用不同规格的凉液垫放置在受压部位进行保护,比较两组病人压疮发生情况及体位所需的生理弯曲符合情况。[结果]试验组病人压疮发生率低于对照组,体位所需的生理弯曲符合率高

  10. Finite element analysis as a tool for parametric prosthetic foot design and evaluation. Technique development in the solid ankle cushioned heel (SACH) foot.

    Science.gov (United States)

    Saunders, Marnie M; Schwentker, Edwards P; Kay, David B; Bennett, Gordon; Jacobs, Christopher R; Verstraete, Mary C; Njus, Glen O

    2003-02-01

    In this study, we developed an approach for prosthetic foot design incorporating motion analysis, mechanical testing and computer analysis. Using computer modeling and finite element analysis, a three-dimensional (3D), numerical foot model of the solid ankle cushioned heel (SACH) foot was constructed and analyzed based upon loading conditions obtained from the gait analysis of an amputee and validated experimentally using mechanical testing. The model was then used to address effects of viscoelastic heel performance numerically. This is just one example of the type of parametric analysis and design enabled by this approach. More importantly, by incorporating the unique gait characteristics of the amputee, these parametric analyses may lead to prosthetic feet more appropriately representing a particular user's needs, comfort and activity level.

  11. N-acetyl-S-(n-propyl)-l-cysteine in urine from workers exposed to 1-bromopropane in foam cushion spray adhesives.

    Science.gov (United States)

    Hanley, Kevin W; Petersen, Martin R; Cheever, Kenneth L; Luo, Lian

    2009-10-01

    1-Bromopropane (1-BP) has been marketed as an alternative for ozone depleting and other solvents; it is used in aerosol products, adhesives, metal, precision, and electronics cleaning solvents. Mechanisms of toxicity of 1-BP are not fully understood, but it may be a neurological and reproductive toxicant. Sparse exposure information prompted this study using 1-BP air sampling and urinary metabolites. Mercapturic acid conjugates are excreted in urine from 1-BP metabolism involving debromination. Research objectives were to evaluate the utility of urinary N-acetyl-S-(n-propyl)-L-cysteine (AcPrCys) for assessing exposure to 1-BP and compare it to urinary bromide [Br((-))] previously reported for these workers. Forty-eight-hour urine specimens were obtained from 30 workers at two factories where 1-BP spray adhesives were used to construct polyurethane foam seat cushions. Urine specimens were also obtained from 21 unexposed control subjects. All the workers' urine was collected into composite samples representing three time intervals: at work, after work but before bedtime, and upon awakening. Time-weighted average (TWA) geometric mean breathing zone concentrations were 92.4 and 10.5 p.p.m. for spraying and non-spraying jobs, respectively. Urinary AcPrCys showed the same trend as TWA exposures to 1-BP: higher levels were observed for sprayers. Associations of AcPrCys concentrations, adjusted for creatinine, with 1-BP TWA exposure were statistically significant for both sprayers (P < 0.05) and non-sprayers (P < 0.01). Spearman correlation coefficients for AcPrCys and Br((-)) analyses determined from the same urine specimens were highly correlated (P < 0.0001). This study confirms that urinary AcPrCys is an important 1-BP metabolite and an effective biomarker for highly exposed foam cushion workers.

  12. Msx1 and Msx2 are required for endothelial-mesenchymal transformation of the atrioventricular cushions and patterning of the atrioventricular myocardium

    Directory of Open Access Journals (Sweden)

    Maxson Robert E

    2008-07-01

    Full Text Available Abstract Background Msx1 and Msx2, which belong to the highly conserved Nk family of homeobox genes, display overlapping expression patterns and redundant functions in multiple tissues and organs during vertebrate development. Msx1 and Msx2 have well-documented roles in mediating epithelial-mesenchymal interactions during organogenesis. Given that both Msx1 and Msx2 are crucial downstream effectors of Bmp signaling, we investigated whether Msx1 and Msx2 are required for the Bmp-induced endothelial-mesenchymal transformation (EMT during atrioventricular (AV valve formation. Results While both Msx1-/- and Msx2-/- single homozygous mutant mice exhibited normal valve formation, we observed hypoplastic AV cushions and malformed AV valves in Msx1-/-; Msx2-/- mutants, indicating redundant functions of Msx1 and Msx2 during AV valve morphogenesis. In Msx1/2 null mutant AV cushions, we found decreased Bmp2/4 and Notch1 signaling as well as reduced expression of Has2, NFATc1 and Notch1, demonstrating impaired endocardial activation and EMT. Moreover, perturbed expression of chamber-specific genes Anf, Tbx2, Hand1 and Hand2 reveals mispatterning of the Msx1/2 double mutant myocardium and suggests functions of Msx1 and Msx2 in regulating myocardial signals required for remodelling AV valves and maintaining an undifferentiated state of the AV myocardium. Conclusion Our findings demonstrate redundant roles of Msx1 and Msx2 in regulating signals required for development of the AV myocardium and formation of the AV valves.

  13. Study of Cushioning Properties of Loose Filling Materials%松散填充材料的缓冲性能研究

    Institute of Scientific and Technical Information of China (English)

    徐熙燕; 康勇刚

    2012-01-01

    Loose filling material has suitability and convenience in packing operation, and can be used for packa- ging of products with varied shape, size and dimension. Packaging protection function of the material is deter- mined by its loading ability, cushioning packaging property, and the ability of proper securing products inside the container. Tests of static compression, dynamic impact, and degree of migration were carried out to four different types of loose filling material. The packaging properties of the loose filling materials were analyzed and compared with moulded pulp loose filling material. The influence of single unit structure and shape of loose filling material on cushioning property and securing function was explained.%松散填充材料可以用于对任意规格尺寸及形状的产品进行缓冲包装和固定,具有包装作业的方便性和适用性。松散填充材料的载荷能力、缓冲包装性能及对产品的固定作用,决定了这一材料的包装保护功能。通过对4种结构形状的松散填充材料在静态压缩、动态冲击和迁移性方面的测试与评价,分析了各种松散填充材料的包装性能,并与纸浆模制松散填充材料进行了比较,说明了松散填充材料单体结构形状对其缓冲性能和固定作用的影响。

  14. How do bryophytes govern generative recruitment of vascular plants?

    Science.gov (United States)

    Soudzilovskaia, Nadejda A; Graae, Bente J; Douma, Jacob C; Grau, Oriol; Milbau, Ann; Shevtsova, Anna; Wolters, Loes; Cornelissen, Johannes H C

    2011-06-01

    Interactions between vascular plants and bryophytes determine plant community composition in many ecosystems. Yet, little is known about the importance of interspecific differences between bryophytes with respect to their effects on vascular plants. We compared the extent to which species-specific bryophyte effects on vascular plant generative recruitment depend on the following underlying mechanisms: allelopathy, mechanical obstruction, soil moisture and temperature control. We sowed 10 vascular plant species into monospecific mats of six chemically and structurally diverse bryophytes, and examined 1-yr seedling recruitment. Allelopathic effects were also assessed in a laboratory phyto-assay. Although all bryophytes suppressed vascular plant regeneration, there were significant differences between the bryophyte species. The lack of interactions indicated the absence of species-specific adaptations of vascular plants for recruitment in bryophyte mats. Differences between bryophyte species were best explained by alterations in temperature regime under bryophyte mats, mostly by reduced temperature amplitudes during germination. The temperature regime under bryophyte mats was well predicted by species-specific bryophyte cushion thickness. The fitness of established seedlings was not affected by the presence of bryophytes. Our results suggest that climatically or anthropogenically driven changes in the species' composition of bryophyte communities have knock-on effects on vascular plant populations via generative reproduction.

  15. An Objective Evaluation Method for the Comfort of Foam Cushion in Vehicle Sea%汽车泡沫坐垫舒适性的客观评价方法

    Institute of Scientific and Technical Information of China (English)

    金晓萍; 袁向科; 王波; 陶鑫; 成波; 丁教霞; 李志辉

    2012-01-01

    介绍了评价汽车座椅泡沫坐垫舒适性的物理特性指标和体压分布指标,以及两者之间的关系.研究结果表明,体压分布能综合反映坐垫的舒适性,而物理特性则为坐垫材料的选取提供理论依据.因此在泡沫坐垫舒适性设计和评价中,宜综合使用上述两种评价指标.%Two indicators, physical characteristics and body pressure distribution, as well as their relationship are presented in this paper for evaluating the comfort of foam cushion in vehicle seat. The results of study show that body pressure distribution can comprehensively reflect the comfort of seat cushion, while physical characteristics provides the theoretical basis in selecting foam material. Thus it is appropriate to combine these two evaluation indicators in designing and evaluating the comfort of foam cushion in vehicle seat.

  16. Application of EPS Insulation Board Cushion to the Slope in Hongqi Reservoir%EPS 保温板垫层在红旗水库护坡中的应用

    Institute of Scientific and Technical Information of China (English)

    郭伟

    2015-01-01

    Through the application of contrast polystyrene insulation cushion( EPS) and gravel cushion solution in Hongqi reservoir upstream concrete slab revetment of Liaoning province, with the analysis of prototype observation test and data for three years, EPS insulation board replacement sand gravel cushion has been put forward to use as slope protection, and which is feasible in northern cold area .This technology can effectively reduce freezing depth of the soil under the slope.It can reduce the frost heave deformation and solves the problem of frost heaving of the dam slope.%通过对辽宁省红旗水库上游混凝土板护坡下应用聚苯乙烯(简称EPS)保温板垫层和砂砾石垫层方案对比,经过三年的原型观测试验及数据分析,提出在寒冷地区使用EPS保温板替代砂砾石作为护坡垫层的可行性。该技术能够有效降低护坡下土体冻结深度,减少冻胀变形,解决了坝坡的冻胀问题。

  17. A novel bionic design of dental implant for promoting its long-term success using nerve growth factor (NGF): utilizing nano-springs to construct a stress-cushioning structure inside the implant.

    Science.gov (United States)

    He, Hao; Yao, Yang; Wang, Yanying; Wu, Yingying; Yang, Yang; Gong, Ping

    2012-08-01

    The absence of periodontium causes masticatory load in excess of the self-repairing potential of peri-implant bone; peri-implant bone loss caused by occlusal overload is not uncommon in patients and greatly diminishes chances of long-term success. Regenerative treatments may be useful in inducing peri-implant bone regeneration, but are only stopgap solutions to the aftermaths caused by the imperfect biomechanical compatibility of the dental implant. Despite promising success, the tissue-engineered periodontal ligament still needs a period of time to be perfected before being clinically applied. Hence, we propose a novel design of dental implant that utilizes nano-springs to construct a stress-cushioning structure inside the implant. Many studies have shown that NGF, a neurotrophin, is effective for nerve regeneration in both animal and clinical studies. Moreover, NGF has the potential to accelerate bone healing in patients with fracture and fracture nonunion and improve osseointegration of the implant. The key point of the design is to reduce stress concentrated around peri-implant bone by cushioning masticatory forces and distributing them to all the peri-implant bone through nano-springs, and promote osseoperception and osseointegration by NGF-induced nerve regeneration and new bone formation. This design, which transfers the main biomechanical interface of the implant from outside to inside, if proven to be valid, may to some extent compensate for the functions of lost periodontium in stress cushioning and proprioception.

  18. 气垫隔声结构水中隔声性能分析%Analysis of Underwater Performance of Sound Insulation Structure with Air Cushion

    Institute of Scientific and Technical Information of China (English)

    周涛; 陈志坚

    2013-01-01

      提出气垫隔声结构形式,与以橡胶阻尼材料为基体的隔声去耦瓦相比,气垫隔声结构具有孔隙率大的特点,能更好的隔声去耦。用解析方法分析无限、有限气垫隔声结构在水中的隔声性能,研究板厚与中间层特性声阻抗对隔声量的影响并分析无限结构与有限结构的差别。结果表明:在水中的隔声曲线中没有在空气中因“质量―弹簧―质量”共振造成的隔声低谷现象,且在低频时有限结构的隔声性能较好。行波管声学试验测试了气垫双层板结构的低频隔声性能,证实气垫隔声结构在水中的隔声效果和其在水中声学性能的正确性。%The sound insulation structure with air cushion was presented. Compared with the sound-isolating decoupling tiles made of rubber damping material, this structure has better sound-isolating and decoupling effect due to its large porosity. The underwater sound insulation performances of infinite and finite double-layer panel structures with air cushions were studied respectively with analytical method. The influences of panel thickness and characteristic impedance of the middle layer on the sound-isolating performance were analyzed. The results show that the phenomenon of sound-isolation valley due to the mass-spring-mass resonance disappears and the finite-sized structure has a better sound-isolating performance in low frequency range. Finally, traveling wave tube test was carried out to investigate the finite-sized structure. The test results verified the correctness of this method for analyzing the underwater sound insulation performance of the structures.

  19. Cushion Curve Study of Corrugated Paperboard with EBE-flute%EBE楞瓦楞纸板缓冲曲线研究

    Institute of Scientific and Technical Information of China (English)

    黄蜜; 吴淑芳; 杜启祥

    2011-01-01

    Corrugated paperboard is used for transporting packaging,as it has reasonable degradation,cushion and thermal insulation properties.The stress-strain curves was obtained by using universal testing machine.The result showed that the stress-strain curve is%瓦楞纸板因其可降解性、优良的缓冲性能和隔温性能,常用于运输包装中。首先利用万能试验机得到了EBE楞瓦楞纸板静态应力-应变曲线,结果表明瓦楞纸板应力-应变曲线具有非单调性的特点,因此求解瓦楞纸板缓冲曲线需要分段处理。最后计算了EBE瓦楞纸板的缓冲系数-最大应力曲线,并给出了使用缓冲曲线设计包装结构的算例。

  20. Differentiation between solid-ankle cushioned heel and energy storage and return prosthetic foot based on step-to-step transition cost.

    Science.gov (United States)

    Wezenberg, Daphne; Cutti, Andrea G; Bruno, Antonino; Houdijk, Han

    2014-01-01

    Decreased push-off power by the prosthetic foot and inadequate roll-over shape of the foot have been shown to increase the energy dissipated during the step-to-step transition in human walking. The aim of this study was to determine whether energy storage and return (ESAR) feet are able to reduce the mechanical energy dissipated during the step-to-step transition. Fifteen males with a unilateral lower-limb amputation walked with their prescribed ESAR foot (Vari-Flex, Ossur; Reykjavik, Iceland) and with a solid-ankle cushioned heel foot (SACH) (1D10, Ottobock; Duderstadt, Germany), while ground reaction forces and kinematics were recorded. The positive mechanical work on the center of mass performed by the trailing prosthetic limb was larger (33%, p = 0.01) and the negative work performed by the leading intact limb was lower (13%, p = 0.04) when walking with the ESAR foot compared with the SACH foot. The reduced step-to-step transition cost coincided with a higher mechanical push-off power generated by the ESAR foot and an extended forward progression of the center of pressure under the prosthetic ESAR foot. Results can explain the proposed improvement in walking economy with this kind of energy storing and return prosthetic foot.

  1. The perfect ash-storm: large-scale Pyroclastic Density Current experiments reveal highly mobile, self-fluidising and air-cushioned flow transport regime

    Science.gov (United States)

    Lube, G.; Cronin, S. J.; Breard, E.; Valentine, G.; Bursik, M. I.; Hort, M. K.; Freundt, A.

    2013-12-01

    entrainment and upward elutriation of ambient air inside this front. It is immediately followed by the fine-ash rich and highly impermeable main flow body. Passage of the flow body is accompanied by strongly increasing pore-pressures of 1-3 kPa that almost fully supports the weight of the entire underflow - depicting flow-induced fluidisation of the main flow part. The remainder of the flow body shows further increases in pore-pressure aside with strong reductions in flow mass. This suggests the occurrence of zones of air-cushions forming at the base of the underflow that largely aid its inviscid runout. This sequence is repeated during arrival and passage of up to three more flow pulses. The low-permeability deposits maintain high internal gas pore pressures for several minutes after emplacement, before sudden deaeration, settling and gas loss is caused by fracturing. Flow-induced fluidisation and basal air-cushioning provide key processes behind the enigmatic long runout behaviour of dense PDCs.

  2. Expansion cushions for directly buried district heating networks. Main object products of mineral wool; Expansionskuddar foer direktfoerlagda fjaerrvaermeledningar - med huvudinriktning paa mineralullsprodukter

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Sture [Lund Univ. (Sweden). Div. of Heat and Power Engineering; Jensson, B. [Malmoe Energi Fjaerrvaerme (Sweden)

    1995-06-01

    The initiation of this project is the question: How can we decrease the total costs for the construction of directly buried District Heating networks by a simplified routing of the piping and a more optimal use of the pipe material, taking into account the interaction between the piping and the soil and the material properties of the soil? How can long straight routings and bends with need for expansion work together, as the bends in the same time shall be secured against damages in a cost-effective way? When using modern computer based calculation programs, it can be shown that the PUR-insulation in the expansion zones, and particularly in the bends, may suffer a greater risk for being exposed to unacceptable high stresses than the metal service pipe. Therefore, in most cases, the calculated compression stresses in the PUR-foam will become decisive with respect to the routing as such but also with respect to the procedures prescribed when the system is taken into operation. In order to be able to connect long, straight routes of piping to expansion bends and in the same time make sure that the compression stresses of the PUR foam do not exceed permissible values, those bends may have to be supplied with some kind of expansion absorbing devices. One of the main goals of this project has been to look for expansion cushions with suitable material properties, especially with respect to compression. Such a material should remain soft and elastic in the horizontal direction and in the same time offer a support for vertical loads. A material that can swallow large movements of the pipe bend, gently supporting the bend without giving too high reaction forces. 5 refs, 7 figs, 3 appendices

  3. 青岛海湾大桥承台混凝土寒季养护技术%Cold Weather Curing of Cushion Cap Concrete in Qingdao Bay Bridge

    Institute of Scientific and Technical Information of China (English)

    郭保林; 刘征涯; 胡孝展

    2011-01-01

    青岛海湾大桥位于海水含盐度高且存在较严重自然冻融循环的胶州湾海域,施工环境与服役环境都比较恶劣.非通航孔桥承台位于潮差区与浪溅区,为了保证施工期及运营期的混凝土耐久性,采用低水胶比、大掺量矿物掺和料、适量引气的混凝土配制技术,并利用外部围水设施实现海上干法施工.在冬季,为了降低施工期外界环境对混凝土性能的不利影响,将围水设施顶部用帆布覆盖,内部空间布置加热水箱,承台侧面利用蓄水型模板衬里提供不间断的保湿养护.自浇筑至14d养护龄期内,承台侧面及顶面温度始终高于15℃,相对湿度高于95%,模板衬里内积蓄的水量高于混凝土养护所需要的水量,采取该养护方案实现了承台混凝土的持续保温保湿养护,保证了承台混凝土的各项性能健康发展.%The saline concentration of seawater is comparatively high and there are 50 times of freezing and thawing cycles in Kiaochow bay where the Qingdao Bay Bridge is located, moreover, the construction and service environment are very severe for reinforced concrete structure.The cushion caps of approach bridge are all among tidal zone and splash zone.Low water-cement-ratio, high volume mineral admixtures, and air entraining are the main technology to prepare cushion cap concrete.Some cofferdams are utilized to make the construction environment seawater free.In winter, the top of cofferdams are covered with canvas, the space between cushion cap and canvas are heated by several boiling water tanks, and the lateral surface of cushion cap are curing by controlled permeability formwork liner in order to reduce the disadvantage influence of construction factor to concrete.During the first 14 days curing,the environment temperature around the cushion cap are kept above 15℃ , and the RH is above 95%.The free water contained among controlled permeability formwork liner is more than the need of concrete

  4. 聚苯颗粒制备地面垫层用轻质保温砂浆的研究%Research on the preparation of polystyrene particles lightweight insulation mortar used as ground cushion

    Institute of Scientific and Technical Information of China (English)

    田胜力; 李志博; 徐海峰; 郎昆仑; 杨永峰

    2015-01-01

    研究聚苯颗粒作为轻骨料制备地面垫层用轻质保温隔热砂浆的可行性。采用正交试验探究了水泥、机制砂、聚苯颗粒、HPMC 用量对砂浆的工作性能、力学性能等因素的影响规律。研究表明:采用聚苯颗粒可以制备出工作性能、力学性能优良的地面垫层用轻质保温砂浆。其28 d 抗压强度达到3.6 MPa、干密度为842 kg?m3,导热系数为0.22 W?(m·K),满足12BJ -1工程做法所要求的干拌复合轻集料混凝土垫层性能指标。%The feasibility of preparing lightweight insulation mortar used as ground cushion by polystyrene particles was studied in this paper.The orthogonal experiment was employed to explore the influence of dosage of cement,manufactured sand,polystyrene particles and HPMC on the workability,mechanical properties and other factors of the mortar.The results show lightweight insulation mortar used as ground cushion with excellent performance can be prepared with polystyrene particles.The 28 days compressive strength of prepared mortar reach 3.6 MPa,dry density is 842 kg?m3 ,the thermal conductivity is 0.22 W?(m·K),which meet the performance index of dry mix composite lightweight aggregate concrete cushion in the standard of 12BJ - 1.

  5. 抗冲地砖对立姿舰员的冲击防护效能分析%Performance of an Elastic Polymer Foam Cushion in Attenuating Responses of Shipboard Standing-men to Vertical Ship Shock

    Institute of Scientific and Technical Information of China (English)

    吴静波; 谌勇; 李兆俊; 黄建松; 华宏星

    2011-01-01

    Protection of shipboard personnel from shock events induced by underwater explosion is very interesting to ship designers. In this study, the potential attenuation performance of an elastic polymer foam cushion inserted between standing-man and ship deck is investigated theoretically. An 8-DOF nonlinear lumped-parameter model is used to predict the standing-man's biodynam-ic responses and injury potential. The cushion is modeled by a chain of masses separated by nonlinear springs and dampers in parallel to simulate the micro inertia, stiffness and rate-dependent effects exhibited by common polymer cellular materials. Two variables, kickoff speed (KS) ratio and deck reaction force (DRF) ratio corresponding to two types of typical injury potential of standing-men, are defined as evaluation parameters. The influence of critical buckling force level, material rate dependent effect as well as other design factors on the attenuation performance of the foam cushion is discussed in detail. Some general design rules are also presented.%利用八自由度集总参数模型描述立姿舰员的生物动力学响应并预测其受损趋势,应用非线性质量-弹簧及阻尼模型模拟多孔结构的微惯性、刚度及粘性效应.定义最大抛离速度比及最大甲板反力比评价抗冲地砖的防护效果,讨论了抗冲地砖的无量纲临界屈曲力水平、粘性效应对其人员防护效果的影响,给出了人员抗冲用抗冲地砖应遵循的一般设计原则.

  6. The optimum design with multiple target of the inspection device with rebber shock-absorbing cushion%橡胶减振垫送检装置的多目标规划优化设计研究

    Institute of Scientific and Technical Information of China (English)

    石怀荣; 芮延年; 张辉

    2011-01-01

    基于机构工作目标和机构运动学特性,采用多目标规划优化设计的方法,研制满足检测减振垫性能的送检机械装置.以满足机构工作特性及机构性能指标为设计优化基础,建立送检机构运动特性、结构参数以及机构工作性能的多目标优化计算模型.研究分析各目标函数间的相互关联性,建立减振垫送检装置的多目标规划优化设计模型,确定机构优化设计目标函数,以便为自主研发新型、高效减振垫性能检测机械装置提供支持.%According as the optimum design with multiple target and the organizational working goal and characteristic of organizational movement, so that develop the inspection decive to check functions of rebber shock-absorbing cushion. The optimum design based on satisfied the working characteristic and performance of machine, then made the computational model by the optimum design with multiple with motion characteristic ,configuration parameter and working function of the inspection. The model of the optimum design with multiple target of the inspection device with rebber shock-absorbing cushion which set up by the relevance research of each object function,finally establish the optimum design with target. Thus the theoretical principle was been set up to self-developed the inspection device with rebber shock-absorbing cushion by functional, effectively and continuable.

  7. Preparation and Application Performance of Particle Hemp Haulm Board for Cushioning Packaging Material%面向缓冲包装材料的麻杆刨花板制备及应用性能研究

    Institute of Scientific and Technical Information of China (English)

    王风玫; 母军; 张德荣; 李媛媛

    2012-01-01

    利用提取麻纤维后的加工剩余物-麻杆作为原材料,制备了缓冲刨花板。以不同的密度、施胶量以及厚度进行正交试验,测定了刨花板的性能,分析了麻杆刨花板作为缓冲包装材料的应用性能特点。实验结果表明:以麻杆为原料,在热压温度175℃下,用分段式热压工艺制备的刨花板,具有色浅、质轻的特性;在施胶量为10%时,刨花板的静曲强度和弹性模量均为最佳值;当σ〉190N/cm^2时,所制备的麻杆刨花板具有较低的缓冲系数,可替代EPE作为缓冲包装材料。%Cushioning particle board was prepared using hemp haulm as raw material, which was the residue ot hemp fiber production. Orthogonal experiments were carried out with different density, sizing dosage, and thickness, and performance of the particleboard was tested. The application performance of the particleboard as cushion packaging material was analyzed. The results showed that the particleboard has the characteristics of light mass and color when hot-pressing temperature at 175 ℃ and using piecewise hot-pressing process; when the sizing dosage is 10%, static bending strength and elastic modulus is the best; when σ〉190 N/cm^2, the particleboard has lower buffer coefficient and can substitute for EPE as cushioning packaging material.

  8. ICU intensive care unit application effect analysis of air-cushion pressure ulcers prevention%ICU重症监护病房应用防压疮气垫的效果分析

    Institute of Scientific and Technical Information of China (English)

    赵雪梅

    2013-01-01

    目的:探讨ICU重症监护病房应用防压疮气垫的护理效果。方法:将我院重症监护室发生压疮的高危患者40例随机分为观察组和对照组各20例,观察组给予防压疮气垫护理,对照组未采用防压疮气垫防护措施,比较两组的压疮发生率。结果:对照组患者的压疮发生率显著高于观察组,两组比较,差异具有统计学意义(P<0.05)。结论:防压疮气垫能显著降低患者的压疮发生率,是ICU防治高危压疮的有效措施之一。%Objective:To discuss the ICU intensive care unit using the nursing effect of preventing pressure ulcers mattress. Methods:to the intensive care unit 40 patients with higher risk of pressure ulcers were randomly divided into observation group and control group 20 cases, observation group was given care in the air-cushion pressure ulcers, adopt protective measures preventing pressure ulcers air cushion, the control group to compare two groups the incidence of pressure ulcers. Results:the observation group is significantly higher than the control group, the incidence of pressure ulcers in patients with two groups of comparison, the difference statistically significant(P<0.05). Conclusion:for patients with pressure ulcers prevention air cushion bed can significantly reduce the incidence of pressure ulcers, ICU is one of the effective measures of prevention and treatment of pressure ulcers in high-risk patients.

  9. 朝鲜不对称作战的利器——全垫升气垫船%North Korean Smart Weapons of Asymmetry Operation- the Air Cushion Craft

    Institute of Scientific and Technical Information of China (English)

    李中良; 徐清华; 漆巍; 英戈

    2015-01-01

    As the South Korea procured a lot new surface warships,increasing the surface combat strength,forming the maritime advantages against the North Korea,the North Korea has to take the asymmetry measures to respond the great pressure with building a lot air cushion crafts. The thesis describes the types,capabilities,characteristics and deployment of the North Korean air cushion crafts, analyzes why the North Korea develops this kind of surface ship. Its specific operation methods of landing forces delivery,special assault, maritime assault,setting mines and obstacles with the air cushion crafts,studies on the South Korea's fighting measures against the North Korean air cushion crafts,which include destroying bases, air-to-surface attack,area control, distance limitation,and dealing with the wild with accuracy.%随着韩国大力发展水面舰艇增强其海上作战能力,形成对朝鲜的海上优势,朝鲜则不得不采用不对称作战方式应对来自韩国的海上重重压力,大量建造全垫升气垫船.阐述了朝鲜装备全垫升气垫船类型、性能特点及基本部署情况,分析了朝鲜发展气垫船的缘由;剖析了朝鲜采用气垫船实施登陆输送、特种攻击、海上突击和布设水雷障碍的具体使用方法;研究了韩国在反击朝鲜气垫船采取击毁基地、以空制海、以面制点、以远制近、以精确应对粗放的5种战法应对举措.

  10. Analysis and Experimental Study of Air-cushion Pressure Used to Cardboard Adhesive%一种用于纸板黏合的气垫压合分析及实验研究

    Institute of Scientific and Technical Information of China (English)

    高波

    2014-01-01

    Cushion has a wide range of applications in engineering. It is a new attempt to use it in the lamination process of corrugated cardboard adhesive, to get the theoretical analysis and experimental research. It is made to numerical simulation of multi-stoma pressure distribution from a single stomatal mathematical model by using ANSYS finite element software. It can be used to the experimental device that conveyor speed, air supply’s pressure and flow, and air-cushion thickness can be adjusted. Experiments show that the device can meet analysis results by a test system for relevant parameters. The result shows that the pressure of air distribution simulation is in good agreement with the measured results. The corrugated cardboard and pressing orthogonal ex-perimental results show that is the more appropriate for the pressure of air 1000Pa, air cushion thickness 2mm, pressing time 3min, air cushion pressure used in corrugated cardboard and pressing is feasible.%将气垫用于瓦楞纸板黏合的压合工艺是一种新的尝试,为了探讨气垫压力形成、压力分布及工艺效果,进行了理论分析和实验研究。利用ANSYS有限元软件,从单个气孔的压力分布数学模型出发,对多气孔的压力分布进行数值模拟,用一种供风压力、流量、气垫厚度都可调节的气垫压合实验装置,通过相关参数测试系统,验证了分析结果。结果表明:气垫压力分布模拟与实测结果吻合较好,瓦楞纸板黏合压合正交实验表明,选用气垫压力1000Pa、气垫厚度2mm、压合时间3min是比较合适的,气垫压合用于瓦楞纸黏合压合是可行的。

  11. Improved setup and positioning accuracy using a three-point customized cushion/mask/bite-block immobilization system for stereotactic reirradiation of head and neck cancer.

    Science.gov (United States)

    Wang, He; Wang, Congjun; Tung, Samuel; Dimmitt, Andrew Wilson; Wong, Pei Fong; Edson, Mark A; Garden, Adam S; Rosenthal, David I; Fuller, Clifton D; Gunn, Gary B; Takiar, Vinita; Wang, Xin A; Luo, Dershan; Yang, James N; Wong, Jennifer; Phan, Jack

    2016-05-08

    The purpose of this study was to investigate the setup and positioning uncertainty of a custom cushion/mask/bite-block (CMB) immobilization system and determine PTV margin for image-guided head and neck stereotactic ablative radiotherapy (HN-SABR). We analyzed 105 treatment sessions among 21 patients treated with HN-SABR for recurrent head and neck cancers using a custom CMB immobilization system. Initial patient setup was performed using the ExacTrac infrared (IR) tracking system and initial setup errors were based on comparison of ExacTrac IR tracking system to corrected online ExacTrac X-rays images registered to treatment plans. Residual setup errors were determined using repeat verification X-ray. The online ExacTrac corrections were compared to cone-beam CT (CBCT) before treatment to assess agreement. Intrafractional positioning errors were determined using prebeam X-rays. The systematic and random errors were analyzed. The initial translational setup errors were -0.8 ± 1.3 mm, -0.8 ± 1.6 mm, and 0.3 ± 1.9 mm in AP, CC, and LR directions, respectively, with a three-dimensional (3D) vector of 2.7 ± 1.4 mm. The initial rotational errors were up to 2.4° if 6D couch is not available. CBCT agreed with ExacTrac X-ray images to within 2 mm and 2.5°. The intrafractional uncertainties were 0.1 ± 0.6 mm, 0.1 ± 0.6 mm, and 0.2 ± 0.5 mm in AP, CC, and LR directions, respectively, and 0.0° ± 0.5°, 0.0° ± 0.6°, and -0.1° ± 0.4° in yaw, roll, and pitch direction, respectively. The translational vector was 0.9 ± 0.6 mm. The calculated PTV margins mPTV(90,95) were within 1.6 mm when using image guidance for online setup correction. The use of image guidance for online setup correction, in combination with our customized CMB device, highly restricted target motion during treatments and provided robust immobilization to ensure minimum dose of 95% to target volume with 2.0 mm PTV margin for HN-SABR.

  12. 鱼雷缓冲头帽入水冲击性能研究%Water-Entry Impact Performance of Torpedo's Cushion Nose Cap

    Institute of Scientific and Technical Information of China (English)

    徐新栋; 李建辰; 曹小娟

    2012-01-01

    To solve the problems that theoretical analysis of water-entry impact process of torpedo's cushion nose cap is difficult and strength design boundary of the nose cap is not easy to be determined, we build a finite element model of the nose cap water-entry with the software ABAQUS, and analyze the stress distribution of the nose cap assembly during water-entry impact process. The conclusion is drawn that vertical water-entry with minimum velocity is the most safe condition for the nose cap. Taking this condition as the upper limit of the nose cap strength design, key factors that may induce nose cap crack are analyzed. Accordingly, two methods to make the nose cap easy to crack after water-entry are offered, i.e. weakening the strength of the fairing and reducing the friction between the nose cap assembly and torpedo. Simulation results show that combination of two methods can achieve perfect nose cap water-entry.%针对鱼雷缓冲头帽入水冲击过程理论分析困难、头帽强度设计边界难以确定的问题,采用ABAQUS软件建立了头帽入水有限元模型.研究了其入水冲击时组件应力分布规律,得出了尖拱形头帽以最小速度垂直入水时最难破裂,将此工况作为头帽强度设计的上边界,研究了影响头帽破裂的关键因素,相应给出了2种使头帽入水后更易破裂的改进方法,即降低头帽组件与雷体之间摩擦力和削弱整流罩强度,并通过仿真进行了验证.仿真结果表明,这2种改进方法都可以使头帽更容易破裂,如果同时采用这2种方法,则能够达到更理想的入水效果.

  13. INVESTIGATION OF PRESSURIED THE AIR CUSHION WITH MULTIPLE SUPPLY HOLES%多供气孔气垫平台气垫场压力的理论研究

    Institute of Scientific and Technical Information of China (English)

    侯文君; 王鹰

    2001-01-01

    应用流体的复势函数理论及缝隙流动理论,对具有多供气孔的矩形荷载的气垫场进行了理论分析。用大量的源和汇排列的方法找出了满足边界条件的势函数。从而建立了均匀分布的、任意布孔方式的、多供气孔矩形荷载的气垫压力场压力计算方法和公式,编制了计算气垫场任意一点的压力、气垫承载能力,压力中心和流量的计算程序,并用试验验证了理论分析的正确性。%The air cushion field′s pressured rectangular pad with multiple supply holes are analyzed theoretically by use of complex potential theory and slit flow theory. An appropriate potential function, which satisfies the boundary condition is found by using arrays of infinite sources and sinks. Then calculation formulas of this air cushion field′s pressure distribution with any evenly distributed air-supply holes are derived. A calculating program is worked out and theories mentioned are proved to be correct by tests.

  14. Investigate Based on the Energy Method for D etermining Packing MaterialCushioning Curves%基于能量法测试包装材料缓冲曲线的探讨

    Institute of Scientific and Technical Information of China (English)

    丁毅; 陈立民; 苏杰

    2011-01-01

    In order to simplify the steps of processing the date based on the energy method for determining materials, this paper made a material named EPE as an example and took an experiment on it based on the energy method. By using of Excel software to obtain the index curves and the cushioning curves under any falling height, thereby, we can detemine the cushioning curves conveniently and quickly.%为简化能量法测试材料缓冲曲线的数据处理步骤,以某一种密度的EPE(发泡聚乙烯)材料为例,基于能量法对其进行试验,根据试验数据运用Excel软件得出对应的能量法的指数曲线并得出这种材料在某一跌落高度下的缓冲曲线图,为能够方便、快捷地得出任意跌落高度下的缓冲曲线作出指导.

  15. The Overall Scheme Selection of Rubble Leveling for Gravel Cushion Laying Ship on Hong Kong-Zhuhai-Macao Bridge%港珠澳大桥沉管碎石垫层铺设船(平台)抛石整平总体方案选型

    Institute of Scientific and Technical Information of China (English)

    杨秀礼; 邵曼华; 徐杰

    2014-01-01

    港珠澳大桥沉管隧道采用先铺法碎石垫层基础,拟建造专用碎石铺设船(平台)。详细介绍了港珠澳大桥沉管垫层铺设要求,通过对比国内外碎石垫层施工装备铺设的几种工艺及特点,确定港珠澳大桥专用整平船采用支撑平台式,抛石管抛石整平总体方案。%The tunnel construction project of Hong Kong-Zhuhai-Macao Bridge adopts the method of pre-bedding gravel cushion foundation firstly and plans to build a special ship ( flatworm ) for laying gravel cushion. This paper introduces the requirements of laying gravel cushion for Hong Kong-Zhuhai-Macao Bridge, compares several different construction techniques and features for laying gravel cushion adopted at home and abroad. Through such comparison, the overall scheme of supporting environment and the gravel-laying pipe to lay gravel and level off is used in the construction of the ship’ s major structure.

  16. Preparation and properties of cushion packaging material based on mycelium%基于菌丝体的缓冲包装材料制备及性能研究

    Institute of Scientific and Technical Information of China (English)

    吴豪; 赵鹏; 章琦; 冯硕; 张治国; 孙耀宇

    2015-01-01

    为解决不可降解的废弃塑料类包装材料对环境造成的污染,以棉籽壳、稻壳、麸皮为主要原料,制备了一种基于菌丝体的新型缓冲包装材料———“蘑菇包装”。为了满足不同的需求,将棉籽壳、稻壳、麸皮和水以不同比例混合制作培养基,然后接种不同的菌种,使之生长出不同性能的缓冲包装材料。结果表明:金针菇、鸡腿菇、平菇2005生长速度快于其他菌种,棉籽壳含量越高的培养基中菌丝体的生长情况越好。通过静态压缩试验发现,平菇2005相比较其他菌种,应力变化较小,而且有不错的回弹性能。综合来看,平菇2005与以纯棉籽作为材料制作的缓冲包装材料性能最好。对比平菇2005‐A与EPS材料的缓冲性能表明,平菇2005缓冲包装材料完全可以替代发泡聚苯乙烯包装材料。%We produce a new cushion packaging materials based on mycelium called mushroom packaging ,w hich is made by cottonseed hulls , rice husk and bran to solve the problem of environmental pollution caused by the non‐biodegradable waste plastics packaging materials .In order to meet different needs ,we use cottonseed hulls ,rice husk ,bran and water mixed in different proportions to produce medium and then inoculate them with different strains ,so that we can get the cushion packaging material with different performance .Results show that the needle mushroom ,chicken leg mushroom and oyster mushroom 2005 grow faster than other species ,the higher content of seed coats of medium brings ,the better mycelial grows .Through the static compression experiment found that oyster mushroom 2005 compared with other strains ,stress change is small ,and can have good resilience . T he cushion packaging material made by oyster mushroom 2005 and pure cotton seed have the best performance . Contrast between mushroom 2005‐A and the cushioning property of EPS material show that the buffer packaging

  17. 混凝土面板堆石坝垫层料上游坡面施工技术简介%Construction technology for cushion material upstream slope face of concrete face-slab rockfill dam

    Institute of Scientific and Technical Information of China (English)

    李仙

    2014-01-01

    介绍了面板堆石坝的特点及垫层料上游坡面的主要施工方法,以及斜坡碾压固坡技术、挤压边墙施工技术、移动边墙施工技术和翻模固坡技术的施工工艺流程,及其在工程实施中的应用效果。%An introduction was made on the characteristics of face-slab rockfill dam,main construction technolo⁃gies for cushion material upstream slope face,the technical programs and application effects of slope roller compac⁃tion reinforcement technology,extrusion side wall construction technology,shift side wall construction technology and turn-over form slope reinforcement technology.

  18. Cell physiology of plants growing in cold environments.

    Science.gov (United States)

    Lütz, Cornelius

    2010-08-01

    UV. Thus, their defense and antioxidant role dominates. Ultrastructural comparisons were unable to find special light adaptations in plants taken from polar regions vs. high alpine species. The only adaptation found at the subcellular level for most alpine and polar plants are protrusions of the chloroplast envelopes. They are seen as a demand for fast membrane transport requiring additional membrane surface area, whereby the increase in stroma volume may help to support carbohydrate formation. Plants forming such protrusions have to cope with a short vegetation time. These observations are connected to the question as to how photosynthesis works quite well even at or under zero temperatures. The interplay between plastids, mitochondria, and peroxisomes, known as photorespiration, seems to be more intense than in lowland plants. This organelle cooperation serves as a valve for a surplus in solar energy input under cold conditions. Additional metabolic acclimations are under investigation, such as the role of an alternative plastid terminal oxidase. Plants from cold environments may also be seen as ideal objects for studying the combined effects of high light plus cold resistance-from the molecular level to the whole plant adaptation. Modern instrumentation makes it possible to perform vital metabolic measurements under outdoor conditions, and research stations in remote polar and alpine areas provide support for scientists in the preparation of samples for later cellular studies in the home laboratory.

  19. 完全性心内膜垫缺损合并右室双出口的双心室修复%Biventricular refair for endocardial cushion defects with double outlet right ventricle

    Institute of Scientific and Technical Information of China (English)

    李富骊; 尤斌; 李平; 郑铁; 许李力; 徐屹; 刘硕

    2011-01-01

    目的 总结完全性心内膜垫缺损合并右室双出口双心室修复的经验.方法 2006年7月至209年11月对6例完全性心内膜垫缺损合并右室双出口病人采用双片法修补完全性心内膜垫缺损,人工血管补片作右心室内隧道,连接室间隔缺损与主动脉口,引导左心室血经内隧道进入主动脉;应用牛心包补片扩大右室流出道;肺动脉瓣环小者用带瓣补片跨环修补右室流出道;心室内隧道有可能阻塞右室流出道造成重度梗阻者,右室流出道与主肺动脉之间安置带瓣管道(Rastelli手术).结果 术后死亡1例,占16.6%,其余病例恢复良好.结论 完全性心内膜垫缺损合并右室双出口一期双心室修复可获得良好效果.%Objective Double-outlet right ventricle,which often associated with total anomalous pulmonary venous connection and complete endocardial cushion defects,has been considered a risk factor for biventricular repair procedure.To reviewed cases treated by biventricular repair for endocardial cushion defects with double outlet right ventricle.Methods From July to November of 2009,6 patients (3 males and 3 females) aged from 7 to 24 (16.17±5.98) years and with endocardial cushion defects and double outlet right ventricle underwent operation of biventricular repair The duration of follow-up ranged from 10 days to 2 years(median,16 months).Endocardial cushion defects were repaired with a 2-patch technique.The artificial vascular patch was implanted to connect the ventricular septal defects and the aorta for draining the blood stream from the left ventricle to the aorta.The other patch was used to repair the ostium primum atrial septal defects.Right ventricular outflow tract obstructions was released and reconstructed by transplanting a bovine pericardium patch.If the size of pulmonary valve annulus was far more below the normal,a transannular pericardial patch was used.Rastelli procedure with a valved conduit between the right

  20. Poisonous Plants

    Science.gov (United States)

    ... Publications and Products Programs Contact NIOSH NIOSH POISONOUS PLANTS Recommend on Facebook Tweet Share Compartir Photo courtesy ... U.S. Department of Agriculture Many native and exotic plants are poisonous to humans when ingested or if ...

  1. Aquatic plants

    DEFF Research Database (Denmark)

    Madsen, T. V.; Sand-Jensen, K.

    2006-01-01

    Aquatic fl owering plants form a relatively young plant group on an evolutionary timescale. The group has developed over the past 80 million years from terrestrial fl owering plants that re-colonised the aquatic environment after 60-100 million years on land. The exchange of species between...... terrestrial and aquatic environments continues today and is very intensive along stream banks. In this chapter we describe the physical and chemical barriers to the exchange of plants between land and water....

  2. Manufacturing Plants

    Institute of Scientific and Technical Information of China (English)

    TANG YUANKAI

    2010-01-01

    @@ Sunshine, air and soil are indispensable for green plants. This might be axi-omatic but not in a plant factory. By creating a plant factory, scientists are trying to grow plants where natural elements are deficient or absent, such as deserts,islands, water surfaces, South and North poles and space, as well as in human habi-tats such as skyscrapers in modern cities.

  3. Manufacturing Plants

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    China starts to produce vegetables and fruits in a factory sunshine,air and soil are indispensable for green plants. This might be axiomatic but not in a plant factory. By creating a plant factory,scientists are trying to grow plants where natural elements are deficient or absent,such as deserts, islands,water surfaces,South and North poles and space,as well as in human habitats such as skyscrapers in modern cities.

  4. Medicinal Plants.

    Science.gov (United States)

    Phillipson, J. David

    1997-01-01

    Highlights the demand for medicinal plants as pharmaceuticals and the demand for health care treatments worldwide and the issues that arise from this. Discusses new drugs from plants, anticancer drugs, antiviral drugs, antimalarial drugs, herbal remedies, quality, safety, efficacy, and conservation of plants. Contains 30 references. (JRH)

  5. Autoluminescent plants.

    Directory of Open Access Journals (Sweden)

    Alexander Krichevsky

    Full Text Available Prospects of obtaining plants glowing in the dark have captivated the imagination of scientists and layman alike. While light emission has been developed into a useful marker of gene expression, bioluminescence in plants remained dependent on externally supplied substrate. Evolutionary conservation of the prokaryotic gene expression machinery enabled expression of the six genes of the lux operon in chloroplasts yielding plants that are capable of autonomous light emission. This work demonstrates that complex metabolic pathways of prokaryotes can be reconstructed and function in plant chloroplasts and that transplastomic plants can emit light that is visible by naked eye.

  6. Plant volatiles.

    Science.gov (United States)

    Baldwin, Ian T

    2010-05-11

    Plant volatiles are the metabolites that plants release into the air. The quantities released are not trivial. Almost one-fifth of the atmospheric CO2 fixed by land plants is released back into the air each day as volatiles. Plants are champion synthetic chemists; they take advantage of their anabolic prowess to produce volatiles, which they use to protect themselves against biotic and abiotic stresses and to provide information - and potentially disinformation - to mutualists and competitors alike. As transferors of information, volatiles have provided plants with solutions to the challenges associated with being rooted in the ground and immobile.

  7. Reduced risk insecticides to control scale insects and protect natural enemies in the production and maintenance of urban landscape plants.

    Science.gov (United States)

    Frank, Steven D

    2012-04-01

    Armored scale insects are among the most difficult to manage and economically important arthropod pests in the production and maintenance of urban landscape plants. This is because of morphological traits that protect them from contact insecticides. I compared initial and season-long control of euonymus scale, Unaspis euonymi Comstock (Hemiptera: Diaspidae), by reduced-risk insecticides (insect growth regulators [IGRs], neonicotinoids, spirotetramat) to determine if they controlled scale as well as more toxic insecticides such as the organophosphate, acephate, and pyrethroid, bifenthrin. I also evaluated how these insecticides affected natural enemy abundance on experimental plants and survival when exposed to insecticide residue. All insecticides tested reduced first generation euonymus scale abundance. In 2009, reinfestation by second generation euonymus scale was highest on plants treated with acetamiprid and granular dinotefuran. In 2010, systemic neonicotinoids and spirotetramat prevented cottony cushion scale infestation 133 d after treatment whereas scale readily infested plants treated with bifenthrin and horticultural oil. Encarsia spp. and Cybocephalus spp. abundance was related to scale abundance. These natural enemies were generally less abundant than predicted by scale abundance on granular dinotefuran treated plants and more abundant on granular thiamethoxam treated plants. Bifenthrin residue killed 90-100% of O. insidiosus and E. citrina within 24 h. My results indicate that reduced risk insecticides can provide season-long scale control with less impact on natural enemies than conventional insecticides. This could have economic and environmental benefits by reducing the number of applications necessary to protect nursery and landscape plants from scale.

  8. [Plant hormones, plant growth regulators].

    Science.gov (United States)

    Végvári, György; Vidéki, Edina

    2014-06-29

    Plants seem to be rather defenceless, they are unable to do motion, have no nervous system or immune system unlike animals. Besides this, plants do have hormones, though these substances are produced not in glands. In view of their complexity they lagged behind animals, however, plant organisms show large scale integration in their structure and function. In higher plants, such as in animals, the intercellular communication is fulfilled through chemical messengers. These specific compounds in plants are called phytohormones, or in a wide sense, bioregulators. Even a small quantity of these endogenous organic compounds are able to regulate the operation, growth and development of higher plants, and keep the connection between cells, tissues and synergy between organs. Since they do not have nervous and immume systems, phytohormones play essential role in plants' life.

  9. Simulation of Structure Falling Slamming Process Affected by Air Cushion and Wind%空气垫与来风对结构物坠落砰击影响的仿真

    Institute of Scientific and Technical Information of China (English)

    朱良生; 于龙飞; 张善举; 李健华

    2015-01-01

    As the air cushion and the wind both greatly affect the falling process of marine structures from the sky into the water, this paper proposes an air-solid coupled mathematical model to describe the falling slamming process of 3D complex structures.In the investigation, the falling mechanism of structures is analyzed, the air damping and the 6DOF ( Degree of Freedom) motion characteristics are fully taken into consideration, and the three-dimension transient N-S equation, the turbulence dynamic equation, the energy equation and the rigid 6DOF kinematic equa-tion are comprehensively adopted.The proposed model is then applied to numerically simulate the falling slamming process of a structure from the air into the water, and the results are compared with those obtained by the physical model, finding that the proposed model is effective in simulating the falling slamming process.Moreover, from the simulated results obtained at different falling heights or in different wind blow environments, it is found that (1) the existence of air cushion changes not only the structure slamming speed but also the pressure distribution;( 2 ) the slamming may result in a temperature rise of the air cushion; and ( 3 ) the wind blow changes the falling pose of structures and makes the structures fall from the air with a “zigzag” pose and then slam into the water.%针对空气垫及来风对海洋结构物空中坠落入水过程产生重要影响的问题,在对结构物坠落机理进行分析的基础上,充分考虑结构物在空中坠落过程中所受到的空气阻尼及六自由度运动特点,结合流体三维瞬态N-S方程、湍流动力方程、能量方程和刚体6自由度运动方程,建立了三维复杂结构物空中坠落砰击入水的气-固耦合过程数学模型。对结构物坠落砰击入水的数值模拟结果与物模试验结果的比较表明,该数学模型能有效模拟空气中的坠落砰击过程。对不同高度以及来风时的

  10. Electronic plants

    Science.gov (United States)

    Stavrinidou, Eleni; Gabrielsson, Roger; Gomez, Eliot; Crispin, Xavier; Nilsson, Ove; Simon, Daniel T.; Berggren, Magnus

    2015-01-01

    The roots, stems, leaves, and vascular circuitry of higher plants are responsible for conveying the chemical signals that regulate growth and functions. From a certain perspective, these features are analogous to the contacts, interconnections, devices, and wires of discrete and integrated electronic circuits. Although many attempts have been made to augment plant function with electroactive materials, plants’ “circuitry” has never been directly merged with electronics. We report analog and digital organic electronic circuits and devices manufactured in living plants. The four key components of a circuit have been achieved using the xylem, leaves, veins, and signals of the plant as the template and integral part of the circuit elements and functions. With integrated and distributed electronics in plants, one can envisage a range of applications including precision recording and regulation of physiology, energy harvesting from photosynthesis, and alternatives to genetic modification for plant optimization. PMID:26702448

  11. Plant Behavior

    Science.gov (United States)

    Liu, Dennis W. C.

    2014-01-01

    Plants are a huge and diverse group of organisms, ranging from microscopic marine phytoplankton to enormous terrestrial trees epitomized by the giant sequoia: 300 feet tall, living 3000 years, and weighing as much as 3000 tons. For this plant issue of "CBE-Life Sciences Education," the author focuses on a botanical topic that most…

  12. Plant Behavior

    Science.gov (United States)

    Liu, Dennis W. C.

    2014-01-01

    Plants are a huge and diverse group of organisms, ranging from microscopic marine phytoplankton to enormous terrestrial trees epitomized by the giant sequoia: 300 feet tall, living 3000 years, and weighing as much as 3000 tons. For this plant issue of "CBE-Life Sciences Education," the author focuses on a botanical topic that most…

  13. Plant minichromosomes.

    Science.gov (United States)

    Birchler, James A; Graham, Nathaniel D; Swyers, Nathan C; Cody, Jon P; McCaw, Morgan E

    2016-02-01

    Plant minichromosomes have the potential for stacking multiple traits on a separate entity from the remainder of the genome. Transgenes carried on an independent chromosome would facilitate conferring many new properties to plants and using minichromosomes as genetic tools. The favored method for producing plant minichromosomes is telomere-mediated chromosomal truncation because the epigenetic nature of centromere function prevents using centromere sequences to confer the ability to organize a kinetochore when reintroduced into plant cells. Because haploid induction procedures are not always complete in eliminating one parental genome, chromosomes from the inducer lines are often present in plants that are otherwise haploid. This fact suggests that minichromosomes could be combined with doubled haploid breeding to transfer stacked traits more easily to multiple lines and to use minichromosomes for massive scale genome editing.

  14. Construction Techniques for Elastic Vibration-Reducing Cushions of Type-CRTS Ⅰ for Ballastless Tracks%CRTSⅠ型无砟轨道弹性减振垫层施工技术

    Institute of Scientific and Technical Information of China (English)

    孙晓迈

    2012-01-01

    Since type-CRTS Ⅰ ballastless tracks are used in the Shiziyang Tunnel of the Guangzhou-Shenzhen-Hong Kong pas- sengers-oriented railway, in order to reduce the vibration and noise and to improve comfort, the elastic vibration-reducing cush- ioning layer is provided under the CA sand bed, the process of which is applied to the project of passengers-oriented,350 km/h- operated railways at home for the first time. The design, material control and laying techniques for the elastic vibration-reducing cushioning layer are dealt with in detail in the paper, which may serve as a useful reference for projects of similar types in the future.%广深港铁路客运专线狮子洋隧道采用CRTSⅠ型板式无砟轨道,为减少振动、噪音及提供舒适度,在CA砂浆层下设置弹性减振垫层,此工艺在国内时速350km的铁路客运专线项目中首次应用。详细介绍弹性减振垫层的设计、材料控制及铺设技术,对同类工程有借鉴意义。

  15. Poly(lactic acid-co-glycolic acid)-poly(ethylene glycol)-poly(lactic acid-co-glycolic acid) thermogel as a novel submucosal cushion for endoscopic submucosal dissection.

    Science.gov (United States)

    Yu, Lin; Xu, Wei; Shen, Wenjia; Cao, Luping; Liu, Yan; Li, Zhaoshen; Ding, Jiandong

    2014-03-01

    Endoscopic submucosal dissection (ESD) is a clinical therapy for early stage neoplastic lesions in the gastrointestinal tract. It is, however, faced with a crucial problem: the high occurrence of perforation. The formation of a submucosal fluid cushion (SFC) via a fluid injection is the best way to avoid perforation, and thus an appropriate biomaterial is vital for this minimally invasive endoscopic technique. In this study, we introduced an injectable thermogel as a novel submucosal injection substance in ESD. The hydrogel synthesized by us was composed of poly(lactic acid-co-glycolic acid)-poly(ethylene glycol)-poly(lactic acid-co-glycolic acid) (PLGA-PEG-PLGA) triblock copolymers. The polymer/water system was a low-viscosity fluid at room temperature and thus easily injected, and turned into a non-flowing gel at body temperature after injection. The submucosal injection of the thermogel to create SFCs was performed in both resected porcine stomachs and living minipigs. High mucosal elevation with a clear margin was maintained for a long duration. Accurate en bloc resection was achieved with the assistance of the thermogel. The mean procedure time was strikingly reduced. Meanwhile, no obvious bleeding, perforation and tissue damage were observed. The application of the thermogel not only facilitated the ESD procedure, but also increased the efficacy and safety of ESD. Therefore, the PLGA-PEG-PLGA thermogel provides an excellent submucosal injection system, and has great potential to improve the ESD technique significantly.

  16. Evaluación de estrés hídrico en plantas de fresa a raíz desnuda Evaluation of water stress on bare-root strawberry plants

    Directory of Open Access Journals (Sweden)

    César Gutiérrez Vaca

    Full Text Available En el estudio realizado se determinó el tiempo disponible antes de aplicar riego vía goteo, después de plantar fresa a raíz desnuda en suelo acolchado con humedad a punto de marchitamiento permanente, sin poner en riesgo de muerte a la planta. Con el propósito de diseñar una trasplantadora para plantas a raíz desnuda que opere sobre suelos secos acolchados. Se analizaron 4 tratamientos de riego; se regó una hora antes del trasplante, al momento del trasplante, 1 y 2 horas después del trasplante. El experimento se llevó a cabo en noviembre de 2007 en la comunidad "El Copal", municipio de Irapuato, Guanajuato, México; donde la altura sobre el nivel del mar es de 1 720 m; el suelo de la región es de textura arcillo-limoso cuya humedad de punto de marchitamiento permanente es alrededor de 18%. El plástico utilizado fue de color blanco al exterior, negro al interior con 30 µm de espesor. Se determinó que es viable aplicar el riego al momento de realizar el trasplante y hasta dos horas después sin exponer la integridad de la planta, con 95% de certidumbre. Se concluye que es posible realizar el trasplante mecanizado de plantas de fresa a raíz desnuda sobre suelo acolchado seco al ambiente, lo que permitirá que la trasplantadora en cuestión pueda operar.This study determined the time available before irrigating, after planting bare-root strawberry plants in soil cushioned with moisture before rotting permanently, without risking the plant's life. This, in order to design a grafting device for bare-root plants that runs on dry cushioned soils.Four irrigation treatments were analyzed; one was applied an hour before transplanting, another when transplanting, and 1 and 2 hours afterwards. The experiment was carried out in November 2007 in the town of "El Copal", in the municipality of Irapuato, Guanajuato, Mexico; the location's height is 1 720 masl; the soil is silty clay loam and the rotting point humidity is around 18%. The plastic

  17. Plant Macrofossils

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Records of past vegetation and environmental change derived from plant remains large enough to be seen without a microscope (macrofossils), such as leaves, needles,...

  18. Seed planting

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes prairie seed plantings on Neal Smith National Wildlife Refuge (formerly Walnut Creek National Wildlife Refuge) between 1992 and 2009.

  19. T Plant

    Data.gov (United States)

    Federal Laboratory Consortium — Arguably the second most historic building at Hanford is the T Plant.This facility is historic in that it's the oldest remaining nuclear facility in the country that...

  20. TRANSGENIC PLANTS

    African Journals Online (AJOL)

    MANAGEMENT OF INSECT PEST RESISTANCE WHILE USING ... Stratégies to delay the development of résistance while using Bt engineered plants are many and would need to be ..... training, pesticide use patterns change, and the.

  1. Snow depth mapping in high-alpine catchments using digital photogrammetry

    Science.gov (United States)

    Bühler, Y.; Marty, M.; Egli, L.; Veitinger, J.; Jonas, T.; Thee, P.; Ginzler, C.

    2015-02-01

    Information on snow depth and its spatial distribution is crucial for numerous applications in snow and avalanche research as well as in hydrology and ecology. Today, snow depth distributions are usually estimated using point measurements performed by automated weather stations and observers in the field combined with interpolation algorithms. However, these methodologies are not able to capture the high spatial variability of the snow depth distribution present in alpine terrain. Continuous and accurate snow depth mapping has been successfully performed using laser scanning but this method can only cover limited areas and is expensive. We use the airborne ADS80 optoelectronic scanner, acquiring stereo imagery with 0.25 m spatial resolution to derive digital surface models (DSMs) of winter and summer terrains in the neighborhood of Davos, Switzerland. The DSMs are generated using photogrammetric image correlation techniques based on the multispectral nadir and backward-looking sensor data. In order to assess the accuracy of the photogrammetric products, we compare these products with the following independent data sets acquired simultaneously: (a) manually measured snow depth plots; (b) differential Global Navigation Satellite System (dGNSS) points; (c) terrestrial laser scanning (TLS); and (d) ground-penetrating radar (GPR) data sets. We demonstrate that the method presented can be used to map snow depth at 2 m resolution with a vertical depth accuracy of ±30 cm (root mean square error) in the complex topography of the Alps. The snow depth maps presented have an average accuracy that is better than 15 % compared to the average snow depth of 2.2 m over the entire test site.

  2. Large-scale environmental controls on microbial biofilms in high-alpine streams

    Directory of Open Access Journals (Sweden)

    T. J. Battin

    2004-01-01

    Full Text Available Glaciers are highly responsive to global warming and important agents of landscape heterogeneity. While it is well established that glacial ablation and snowmelt regulate stream discharge, linkage among streams and streamwater geochemistry, the controls of these factors on stream microbial biofilms remain insufficiently understood. We investigated glacial (metakryal, hypokryal, groundwater-fed (krenal and snow-fed (rhithral streams - all of them representative for alpine stream networks - and present evidence that these hydrologic and hydrogeochemical factors differentially affect sediment microbial biofilms. Average microbial biomass and bacterial carbon production were low in the glacial streams, whereas bacterial cell size, biomass, and carbon production were higher in the tributaries, most notably in the krenal stream. Whole-cell in situ fluorescence hybridization revealed reduced detection rates of the Eubacteria and higher abundance of α-Proteobacteria in the glacial stream, a pattern that most probably reflects the trophic status of this ecosystem. Our data suggest low flow during the onset of snowmelt and autumn as a short period (hot moment of favorable environmental conditions with pulsed inputs of allochthonous nitrate and dissolved organic carbon, and with disproportionately high microbial growth. Tributaries are relatively more constant and favorable environments than kryal streams, and serve as possible sources of microbes and organic matter to the main glacial channel during periods (e.g., snowmelt of elevated hydrologic linkage among streams. Ice and snow dynamics - and their impact on the amount and composition of dissolved organic matter - have a crucial impact on stream biofilms, and we thus need to consider microbes and critical hydrological episodes in future models of alpine stream communities.

  3. On the aerosol-cloud relationship at a high-alpine site

    Energy Technology Data Exchange (ETDEWEB)

    Baltensperger, U.; Schwikowski, M.; Jost, D.T.; Nyeki, S.; Gaeggeler, H.W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    Field experiments at the Jungfraujoch showed that during the presence of a cloud, most of the aerosol mass is transferred into the cloud phase. This results in smaller cloud droplets for increasing aerosol concentration, which increases the albedo of clouds (known as the indirect effect of climate forcing by aerosol particles). (author) 1 fig., 4 refs.

  4. The high alpine bee fauna (Hymenoptera: Apoidea of the Zillertal Alps, Austria

    Directory of Open Access Journals (Sweden)

    Silas Bossert

    2014-06-01

    Full Text Available Bees from the Zemmgrund area in the Zillertal Alps (Austria, Tyrol were collected and determined to investigate the species composition of the area. A total of 61 specimens were collected over a two year period; they represent 24 species from 8 genera. Building on these records, the first commented checklist for the area is presented, with notes on habitats and visited flowers.

  5. Spatially continuous mapping of snow depth in high alpine catchments using digital photogrammetry

    Directory of Open Access Journals (Sweden)

    Y. Bühler

    2014-06-01

    Full Text Available Information on snow depth and its spatial distribution is crucial for many applications in snow and avalanche research as well as in hydrology and ecology. Today snow depth distributions are usually estimated using point measurements performed by automated weather stations and observers in the field combined with interpolation algorithms. However, these methodologies are not able to capture the high spatial variability of the snow depth distribution present in alpine terrain. Continuous and accurate snow depth mapping has been done using laser scanning but this method can only cover limited areas and is expensive. We use the airborne ADS80 opto-electronic scanner with 0.25 m spatial resolution to derive digital surface models (DSMs of winter and summer terrains in the neighborhood of Davos, Switzerland. The DSMs are generated using photogrammetric image correlation techniques based on the multispectral nadir and backward looking sensor data. We compare these products with the following independent datasets acquired simultaneously: (a manually measured snow depth plots (b differential Global Navigation Satellite System (dGNSS points (c Terrestrial Laser Scanning (TLS and (d Ground Penetrating Radar (GPR datasets, to assess the accuracy of the photogrammetric products. The results of this investigation demonstrate the potential of optical scanners for wide-area, continuous and high spatial resolution snow-depth mapping over alpine catchments above tree line.

  6. Causes and effects of long periods of ice cover on a remote high Alpine lake

    Directory of Open Access Journals (Sweden)

    Michael STURM

    2000-09-01

    Full Text Available The response of the physical and chemical limnology of Hagelseewli (2339 m a.s.l. to local meteorological forcing was investigated from 1996 to 1998 using an automatic weather station, thermistor chains, water samples and sediment traps. On-site meteorological measurements revealed the paramount importance of local topographic shading for the limnology of the lake. A high cliff to the south diminishes incident radiation by 15% to 90%, resulting in a long period of ice cover. Hence, the spring and summer seasons are extremely condensed, allowing only about 2 months per year for mixing, oxygen uptake, nutrient inflow, water exchange and phytoplankton growth. Regular measurements of water temperature, chemistry and diatom composition show that Hagelseewli responds very rapidly to changes in nutrient concentrations and light conditions. This response is restricted mainly to an extremely short productivity pulse, which takes place as soon as the lake is completely free of ice. Ice-free conditions are indicated by the occurrence of planktonic diatoms. In contrast to most low-altitude lakes, maximum productivity occurs in the middle of the water column (6-9 m, where first light, and then soluble reactive phosphorus (SRP, are the limiting factors. During the period of thawing, large amounts of ammonium enter the lake. Nevertheless, allochthonous nutrient input is not important because SRP, the limiting nutrient for algal growth, originates from the sediments. Water chemistry data and data from sediment traps show that, although autochthonous calcite precipitation does occur, the calcite crystals are redissolved completely in the bottom waters during the extended period of ice cover. Thus, the most important factor for changes in the nutrient budget, primary production and preservation of calcite is the bottom water oxygen status, which is governed by the occurrence of an ice-free period. We hypothesise that the duration of the ice-free period is of minor importance for the generation of particles that might be archived in the sedimentary rec??ord as proxy climate indicators. Such particles are produced mainly during times of peak primary production, which last only for a few days before production decreases again to very low levels. Therefore, with respect to the type of climatic signal that might be recorded in Hagelseewli, we presume that what is most likely to be archived in the sedimentary record is the mere occurrence, rather than the duration of the ice-free period.

  7. [Life-saving air supported avalanche mission at night in high alpine terrain].

    Science.gov (United States)

    Koppenberg, J; Brugger, H; Esslinger, A; Albrecht, R

    2012-10-01

    This is a case report about a helicopter emergency medical service (HEMS) operation during the night in response to an avalanche accident with two completely buried victims. One of the victims was rescued alive after 9.2 h presenting with a patent airway and an air pocket and was successfully rewarmed with forced air from 23°C core temperature without any neurological deficits. After the rescue the patient developed lung edema which resolved spontaneously within 2 days. The second victim was found dead presenting with an air pocket but solid frozen thorax. The special circumstances of the rescue operation and treatment are presented and discussed. The impact of a frozen chest on resuscitation decisions is presented and discussed with an emphasis on the triage of multiple victims.

  8. A Range-Expanding Shrub Species Alters Plant Phenological Response to Experimental Warming.

    Science.gov (United States)

    Kopp, Christopher W; Cleland, Elsa E

    2015-01-01

    Shifts in plant species phenology (the timing of life-history events such as flowering) have been observed worldwide in concert with rising global temperatures. While most species display earlier phenology with warming, there is large variation among, and even within, species in phenological sensitivity to rising temperatures. Other indirect effects of climate change, such as shifting species composition and altered species interactions, may also be contributing to shifting plant phenology. Here, we describe how experimental warming and the presence of a range-expanding species, sagebrush (Artemisia rothrockii), interact to influence the flowering phenology (day of first and peak flowering) and production (number of flowers) of an alpine cushion plant, Trifolium andersonii, in California's White Mountains. Both first flowering and peak flowering were strongly accelerated by warming, but not when sagebrush was present. Warming significantly increased flower production of T. andersonii, but less so in the presence of sagebrush. A shading treatment delayed phenology and lowered flower production, suggesting that shading may be the mechanism by which sagebrush presence delayed flowering of the understory species. This study demonstrates that species interactions can modify phenological responses to climate change, and suggests that indirect effects of rising temperatures arising from shifting species ranges and altered species interactions may even exceed the direct effects of rising temperatures on phenology.

  9. A Range-Expanding Shrub Species Alters Plant Phenological Response to Experimental Warming.

    Directory of Open Access Journals (Sweden)

    Christopher W Kopp

    Full Text Available Shifts in plant species phenology (the timing of life-history events such as flowering have been observed worldwide in concert with rising global temperatures. While most species display earlier phenology with warming, there is large variation among, and even within, species in phenological sensitivity to rising temperatures. Other indirect effects of climate change, such as shifting species composition and altered species interactions, may also be contributing to shifting plant phenology. Here, we describe how experimental warming and the presence of a range-expanding species, sagebrush (Artemisia rothrockii, interact to influence the flowering phenology (day of first and peak flowering and production (number of flowers of an alpine cushion plant, Trifolium andersonii, in California's White Mountains. Both first flowering and peak flowering were strongly accelerated by warming, but not when sagebrush was present. Warming significantly increased flower production of T. andersonii, but less so in the presence of sagebrush. A shading treatment delayed phenology and lowered flower production, suggesting that shading may be the mechanism by which sagebrush presence delayed flowering of the understory species. This study demonstrates that species interactions can modify phenological responses to climate change, and suggests that indirect effects of rising temperatures arising from shifting species ranges and altered species interactions may even exceed the direct effects of rising temperatures on phenology.

  10. Research on Tension Control System for Aluminum Strip Air-cushion Heat Treatment line%铝带气垫式热处理线张力控制系统研究

    Institute of Scientific and Technical Information of China (English)

    付天亮; 韦云松; 王昭东; 李家栋

    2015-01-01

    针对国内某厂铝合金汽车板用气垫式连续热处理线,分析主要工艺设备张力工作特点,采用间接、直接两种张力控制模式对传动系统实施速度和转矩控制,建立了典型工艺设备张力控制方法及整线张力平衡控制策略,构建了以工艺数学模型为核心的张力控制系统.实测表明,静态张力控制精度为-0.05%~0.65%,动态张力控制精度为-3.65%~3.75%,满足热处理线对张力控制精度的需求.%Based on domestic air-cushion continuous heat treatment line for aluminum alloy automobile sheet, tension work characteristics of the main process equipment is analyzed, indirect and direct tension control mode are adopted for dirve system's velocity and torque control. And tension control method for typical process equipment and whole line tension balance control strategy are established, tension control system which centered on process mathematic model is constructed. The results show that static tension control precision is -0.05%~0.65%, and dynamic tension control percision is -3.65%~3.75%, both of which meet the needs of heat treatment line for tension control percision.

  11. 小湾水电站水垫塘抗冲耐磨混凝土施工%Construction of Scour Resistant Concrete for Water Cushion Pool in Xiaowan Hydropower Station

    Institute of Scientific and Technical Information of China (English)

    张捍平

    2013-01-01

      针对小湾水电站坝后水垫塘抗冲耐磨混凝土施工,工程量大,设计标号高,水胶比小,外掺材料多,跨高温、雨季,且抗冲耐磨混凝土粘稠性强,易发干发白、产生干缩裂缝,混凝土振捣困难,抹面平整度难以控制等特点,提出了混凝土配合比优化设计,混凝土拌和,过流面表面不平整处理,早期塑性干缩预防,后期收缩裂缝、温度裂缝预防,雨季施工防雨等措施,保证了施工质量和进度,取得了良好的社会经济效益。%Some difficulties has been encountered in the scour resistant concrete construction of water cushion pool in Xiaowan Hydropower Station: large construction quantity with high design grade , small ratio of water and gel , many mixed materials, high-temperature rainy season , thick abrasion-resistant concrete easy to dry and white which leads to dry shrinkage crack , difficult concrete vibrator and uneven surface .Measures such as optimization design , concrete mix-ing, flow surface roughness treatment , plastic shrinkage prevention in early stage , shrinking and temperature cracks pre-vention in later stage , rain proof in rainy season are proposed in order to ensure construction quality and progress and to achieve good social and economic benefits .

  12. Toxic plants

    Science.gov (United States)

    Reproductive performance is the single most important economic animal trait to the livestock industry and is reported to be 5 and 10 times more significant than carcass quality and growth traits respectively. Poisonous plants impact livestock reproductive function in a major way and have been shown...

  13. Audubon Plant Study Program.

    Science.gov (United States)

    National Audubon Society, New York, NY.

    Included are an illustrated student reader, "The Story of Plants and Flowers," an adult leaders' guide, and a large wall chart picturing 37 wildflowers and describing 23 major plant families. The student reader presents these main topics: The Plant Kingdom, The Wonderful World of Plants, Plants Without Flowers, Flowering Plants, Plants Make Food…

  14. Plant adaptogens.

    Science.gov (United States)

    Wagner, H; Nörr, H; Winterhoff, H

    1994-06-01

    The term adaptogen has not yet been accepted in medicine. This is probably due to the difficulties in discriminating adaptogenic drugs from immunostimulators, anabolic drugs, nootropic drugs, and tonics. There can be not doubt, however, that, at least in animal experiments, there are plant drugs capable of modulating distinct phases of the adaptation syndrome as defined by Seyle. These drugs either reduce stress reactions in the alarm phase or retard / prevent the exhaustion phase and thus provide a certain degree of protection against long-term stress. The small number of drugs the antistress activity of which has been proven or reported includes, among others, the plant drugs Ginseng, Eleutherococcus, Withania, Ocimum, Rhodiola, and Codonopsis. This review summarizes the major findings of pharmacological tests and human studies carried out with these drugs. Currently used assay systems allowing detection of antistress activities are also reported. At present the most likely candidates responsible for the putative antistress activity of plant drugs are special steroids, phenylprogane compounds and lignanes, respectively. Apart from influencing activities of the pituitary-adrenal axis and inducing stress proteins, many adaptogens also possess immunomodulatory and / or anabolic activities. Copyright © 1994 Gustav Fischer Verlag, Stuttgart · Jena · New York. Published by Elsevier GmbH.. All rights reserved.

  15. 带橡胶缓冲垫的出弹装置碰撞有限元分析%Collision finite element analysis of the jacking shells device with rubber cushion

    Institute of Scientific and Technical Information of China (English)

    李少远; 姜贵林; 王洪光; 王茂林; 叶小红

    2014-01-01

    There exists instantaneous collision problem between the rigid mandrel and shells in the rack and pinion jacking shells device. To reduce the collision force, the rubber buffer is added to the end of the jack. Based on the Mooney-Rivlin model, the constitutive model of rubber cushion is established, and the numerical simulation of the collision characteristics between jacking shells device and shells is researched with ANSYS/Workbench. The analysis results show that in the collision process, the maximum stress of the shells is 1.238 7 MPa, far less than the yield strength of the enclosure material of the shells;the tooth contact stress safety factors of rack and pinion are 3.77 and 3.81, respectively, and the tooth root contact stress safety factors are 4.03 and 3.53, respectively, reaching the mini-mum safety factor in a higher reliability requirement.%齿轮齿条式出弹装置刚性顶杆与炮弹之间存在瞬时碰撞问题.为减小碰撞力,在顶杆端部增加橡胶缓冲垫.采用Mooney-Rivlin 模型建立了橡胶缓冲垫的本构模型,并用有限元ANSYS/Workbench软件对带橡胶缓冲垫的出弹装置和炮弹的接触碰撞特性进行数值模拟研究.分析结果表明:带橡胶缓冲垫的顶杆与炮弹的碰撞过程中,炮弹所受的最大应力为1.2387 MPa,远小于炮弹外壳材料的屈服强度;齿轮和齿条的齿面接触应力安全系数分别为3.77和3.81;齿根接触应力安全系数分别为4.03和3.53,均达到较高可靠度时最小安全系数的要求.

  16. Stress tolerant plants

    OpenAIRE

    2014-01-01

    [EN] The invention relates to transgenic plants and methods for modulating abscisic acid (ABA) perception and signal transduction in plants. The plants find use in increasing yield in plants, particularly under abiotic stress.

  17. Plant fertilizer poisoning

    Science.gov (United States)

    Plant fertilizers and household plant foods are used to improve plant growth. Poisoning can occur if someone swallows these products. Plant fertilizers are mildly poisonous if small amounts are swallowed. ...

  18. Stress tolerant plants

    OpenAIRE

    Rubio, Vicente; Iniesto Sánchez, Elisa; Irigoyen Miguel, María Luisa

    2014-01-01

    [EN] The invention relates to transgenic plants and methods for modulating abscisic acid (ABA) perception and signal transduction in plants. The plants find use in increasing yield in plants, particularly under abiotic stress.

  19. Mathematical Model of an Air Cushion Vehicle

    Science.gov (United States)

    1975-05-01

    angle, clockwise from the bow, is output. it is called ABETA . 10. The propeller pitch angles are output from the propulsion control logic (Item 6 in...YWIND/XWIND). This angle in degrees: ABETA =BETAA (180/ITf ) has a range of -180 to +180. Momentum~ Dr. The vehicle experiences reaction forces due to...data shown in figuire 9. SDRAG = .01385 ABET - 7.69 x ABETA2 (70) if, ABETA < 0, SDRAG = - SDRAG. The frontal drag coefficient is curve fit from Bell

  20. Air Cushion Craft Development. First Revision.

    Science.gov (United States)

    1980-01-01

    in Florida. .. ................. 31 20 - Bell-Canada Voyageur and Viking .. .................32 21 - Generalized Breguet Range Chart...continue development. 27 IA-Po Figure 16 -SKMR-1 with and without Skirts 28 The Surface Effect Ships for Ocean Commerce (SESOC) Committee met with...between the U.S. Navy and the Department of Commerce and, as a result, the Joint Surface Effect Ship Program Office (JSESPO) was set up in 1966 to

  1. Plant host finding by parasitic plants: A new perspective on plant to plant communication

    Science.gov (United States)

    Mark C. Mescher; Justin B. Runyon; Consuelo M. De Moraes

    2006-01-01

    Plants release airborne chemicals that can convey ecologically relevant information to other organisms. These plant volatiles are known to mediate a large array of, often complex, interactions between plants and insects. It has been suggested that plant volatiles may have similar importance in mediating interactions among plant species, but there are few well-...

  2. 全垫升式气垫船破冰过程的数值模拟%Numerical simulation for ice-breaking process of an amphibian air cushion vehicle

    Institute of Scientific and Technical Information of China (English)

    卢再华; 张志宏; 胡明勇; 姚俊; 张辽远

    2012-01-01

    A large floating ice sheet can be broken into small slabs with a heavy air cushion vehicle (ACV) traveling on it at a critical speed. Ice-breaking with ACV is a new ice-breaking method in in-land river, it has an important application in prevention of ice jam flood in Yellow River. Here, the ice-breaking process of an ACV was numerically simulated under conditions of shallow water and a thick ice sheet. The simulation results showed that an ACV traveling at a critical speed always chases after the wave crest ahead of it and pushes the waves; thus, the amplitude of the wave around ACV gradually increases due to the continuous push of ACV; initial crack of ice sheet appears at wave trough near the stern of ACV and extends along the axis of ACV in both forward and backward directions; lateral crack at the wave crest ahead of ACV is arisen when the initial crack extends forward to wave crest; an ice-breaking period is finished by ACV accordingly; the cracks behind ACV were shaped as an asterisk symbol along the sailing direction of ACV; the ice sheet breaks into triangular slabs when lateral cracks of different ice-breaking periods intersect with each other; ACV should sail in the same direction parallelly in order to cross the cracks of different ACV voyages and break the ice sheet further.%气垫船破冰是指采用大吨位气垫船以临界航速在冰面上航行进行破冰,是一种较新的内河破冰方法,可应用于黄河凌汛灾害的防治领域.对浅水厚冰层条件下气垫船破冰过程进行了数值模拟.计算结果表明:临界航速下,气垫船始终位于船首波峰后方,对所兴起的船波起持续的推波作用,在冰面上逐渐兴起幅值较大的船波.冰层在船尾波谷处最先产生纵向裂缝并向前后延伸,向前延伸至船首波峰处时引起冰层横向破裂并扩展,完成一个破冰周期.船身后方的裂缝沿气垫船轴线方向呈*号形状,不同破冰周期的横向裂缝交叉后,冰层破裂成

  3. Poinsettia plant exposure

    Science.gov (United States)

    Christmas flower poisoning; Lobster plant poisoning; Painted leaf poisoning ... Leaves, stem, sap of the poinsettia plant ... Poinsettia plant exposure can affect many parts of the body. EYES (IF DIRECT CONTACT OCCURS) Burning Redness STOMACH AND ...

  4. Teaching Plant Reproduction.

    Science.gov (United States)

    Tolman, Marvin N., Ed.; Hardy, Garry R., Ed.

    2000-01-01

    Recommends using Amaryllis hippeastrum to teach young children about plant reproduction. Provides tips for growing these plants, discusses the fast growing rate of the plant, and explains the anatomy. (YDS)

  5. Kansas Power Plants

    Data.gov (United States)

    Kansas Data Access and Support Center — The Kansas Power Plants database depicts, as point features, the locations of the various types of power plant locations in Kansas. The locations of the power plants...

  6. FIELD MEASUREMENT AND ANALYSIS FOR INFLUENCE OF CONCRETE CUSHION AND CONCRETE SHRINKAGE OF HORIZONTAL STRUCTURE ON DEFORMATION OF RETAINING WALL%混凝土垫层及水平结构混凝土收缩对围护墙变形影响的实测分析

    Institute of Scientific and Technical Information of China (English)

    王旭军; 龚剑; 赵锡宏

    2013-01-01

    Based on field measured data,the lateral deformation laws of retaining wall,which belongs to super-large deep foundation pit of Shanghai Tower podium,are analyzed. The analytical results show that,during the period from completion of cushion concrete placement to the completion of beam-slab concrete placement,the increment in lateral deformation of retaining wall is very small,indicating that the constraint effect of cushion on deformation of retaining wall is significant. However,due to the eccentric load effect,the lateral deformation of circle wall,which is the support point of cushion,is relatively large;and it leads to a large increment in lateral deformation of measuring point P04 during this period. Combining with the site construction conditions,the constraint effect of cushion concrete is explained. During the period of structure concrete curing,due to the concrete shrinkage of overlong beam-slab structure or bottom plate,the increment in lateral displacement of retaining wall is large. During the curing period of bottom plate,the increment in lateral deformation of measuring point P23 is larger than that caused by soil excavation for the last time. For the short concrete structure,the effect of concrete shrinkage on the lateral displacement of retaining wall can be neglected. Finally,based on the above laws,some suggestions are proposed to control the deformation of retaining wall effectively.%  基于实测数据,对上海中心大厦裙房逆作超大深基坑工程的围护墙变形规律进行分析。分析结果表明,在垫层混凝土浇筑完成至梁板结构混凝土浇筑完成期间,围护墙侧移增量很小,垫层对围护墙变形具有明显的约束效应;在此期间,因作为垫层支撑点的圆形地墙受偏载作用引起较大的变形,导致测点P04墙体侧移增量较大;结合现场施工条件,对混凝土垫层约束效应的发挥进行说明。在混凝土结构养护期间,超长水平支撑梁

  7. Plant Growth Regulators.

    Science.gov (United States)

    Nickell, Louis G.

    1978-01-01

    Describes the effect of "plant growth regulators" on plants, such as controlling the flowering, fruit development, plant size, and increasing crop yields. Provides a list of plant growth regulators which includes their chemical, common, and trade names, as well as their different use(s). (GA)

  8. Ethylene insensitive plants

    Science.gov (United States)

    Ecker, Joseph R.; Nehring, Ramlah; McGrath, Robert B.

    2007-05-22

    Nucleic acid and polypeptide sequences are described which relate to an EIN6 gene, a gene involved in the plant ethylene response. Plant transformation vectors and transgenic plants are described which display an altered ethylene-dependent phenotype due to altered expression of EIN6 in transformed plants.

  9. Plant Biology Science Projects.

    Science.gov (United States)

    Hershey, David R.

    This book contains science projects about seed plants that deal with plant physiology, plant ecology, and plant agriculture. Each of the projects includes a step-by-step experiment followed by suggestions for further investigations. Chapters include: (1) "Bean Seed Imbibition"; (2) "Germination Percentages of Different Types of Seeds"; (3)…

  10. JSTOR Plant Science

    OpenAIRE

    2010-01-01

    JSTOR Plant Science is an online environment that brings together content, tools, and people interested in plant science. It provides access to foundational content vital to plant science – plant type specimens, taxonomic structures, scientific literature, and related materials, making them widely accessible to the plant science community as well as to researchers in other fields and to the public. It also provides an easy to use interface with powerful functionality that su...

  11. Plant Research '75

    Energy Technology Data Exchange (ETDEWEB)

    1975-01-01

    Research is reported on stomatal regulation of the gas exchanges between plant and environment; inhibitory effects in flower formation; plant growth and development through hormones; hormone action; development and nitrogen fixation in algae; primary cell wall glycoprotein ectensin; enzymic mechanisms and control of polysaccharide and glycoprotein synthesis; molecular studies of membrane studies; sensory transduction in plants; regulation of formation of protein complexes and enzymes in higher plant cell and mechanism of sulfur dioxide toxicity in plants. (PCS)

  12. PLANT BIOPRINTING: NOVEL PERSPECTIVE FOR PLANT BIOTECHNOLOGY

    Directory of Open Access Journals (Sweden)

    Adhityo WICAKSONO

    2015-12-01

    Full Text Available Bioprinting is a technical innovation that has revolutionized tissue engineering. Using conventional printer cartridges filled with cells as well as a suitable scaffold, major advances have been made in the biomedical field, and it is now possible to print skin, bones, blood vessels, and even organs. Unlike animal systems, the application of bioprinting in simple plant tissue cells is still in a nascent phase and has yet to be studied. One major advantage of plants is that all living parts are reprogrammable in the form of totipotent cells. Plant bioprinting may improve scientists’understanding of plant shape and morphogenesis, and could serve for the mass production of desired tissues or plants, or even the production of plant-based biomaterial for industrial uses. This perspectives paper explores these possibilities using knowledge on what is known about bioprinting in other biosystems.

  13. Pathogen Phytosensing: Plants to Report Plant Pathogens

    Directory of Open Access Journals (Sweden)

    C. Neal Stewart

    2008-04-01

    Full Text Available Real-time systems that provide evidence of pathogen contamination in crops can be an important new line of early defense in agricultural centers. Plants possess defense mechanisms to protect against pathogen attack. Inducible plant defense is controlled by signal transduction pathways, inducible promoters and cis-regulatory elements corresponding to key genes involved in defense, and pathogen-specific responses. Identified inducible promoters and cis-acting elements could be utilized in plant sentinels, or ‘phytosensors’, by fusing these to reporter genes to produce plants with altered phenotypes in response to the presence of pathogens. Here, we have employed cis-acting elements from promoter regions of pathogen inducible genes as well as those responsive to the plant defense signal molecules salicylic acid, jasmonic acid, and ethylene. Synthetic promoters were constructed by combining various regulatory elements supplemented with the enhancer elements from the Cauliflower mosaic virus (CaMV 35S promoter to increase basal level of the GUS expression. The inducibility of each synthetic promoter was first assessed in transient expression assays using Arabidopsis thaliana protoplasts and then examined for efficacy in stably transgenic Arabidopsis and tobacco plants. Histochemical and fluorometric GUS expression analyses showed that both transgenic Arabidopsis and tobacco plants responded to elicitor and phytohormone treatments with increased GUS expression when compared to untreated plants. Pathogen-inducible phytosensor studies were initiated by analyzing the sensitivity of the synthetic promoters against virus infection. Transgenic tobacco plants infected with Alfalfa mosaic virus showed an increase in GUS expression when compared to mock-inoculated control plants, whereas Tobacco mosaic virus infection caused no changes in GUS expression. Further research, using these transgenic plants against a range of different

  14. Beginning Plant Biotechnology Laboratories Using Fast Plants.

    Science.gov (United States)

    Williams, Mike

    This set of 16 laboratory activities is designed to illustrate the life cycle of Brassicae plants from seeds in pots to pods in 40 days. At certain points along the production cycle of the central core of labs, there are related lateral labs to provide additional learning opportunities employing this family of plants, referred to as "fast…

  15. Plant Phenotype Characterization System

    Energy Technology Data Exchange (ETDEWEB)

    Daniel W McDonald; Ronald B Michaels

    2005-09-09

    This report is the final scientific report for the DOE Inventions and Innovations Project: Plant Phenotype Characterization System, DE-FG36-04GO14334. The period of performance was September 30, 2004 through July 15, 2005. The project objective is to demonstrate the viability of a new scientific instrument concept for the study of plant root systems. The root systems of plants are thought to be important in plant yield and thus important to DOE goals in renewable energy sources. The scientific study and understanding of plant root systems is hampered by the difficulty in observing root activity and the inadequacy of existing root study instrumentation options. We have demonstrated a high throughput, non-invasive, high resolution technique for visualizing plant root systems in-situ. Our approach is based upon low-energy x-ray radiography and the use of containers and substrates (artificial soil) which are virtually transparent to x-rays. The system allows us to germinate and grow plant specimens in our containers and substrates and to generate x-ray images of the developing root system over time. The same plant can be imaged at different times in its development. The system can be used for root studies in plant physiology, plant morphology, plant breeding, plant functional genomics and plant genotype screening.

  16. Classification of cultivated plants.

    NARCIS (Netherlands)

    Brandenburg, W.A.

    1986-01-01

    Agricultural practice demands principles for classification, starting from the basal entity in cultivated plants: the cultivar. In establishing biosystematic relationships between wild, weedy and cultivated plants, the species concept needs re-examination. Combining of botanic classification, based

  17. Plant tissue culture techniques

    Directory of Open Access Journals (Sweden)

    Rolf Dieter Illg

    1991-01-01

    Full Text Available Plant cell and tissue culture in a simple fashion refers to techniques which utilize either single plant cells, groups of unorganized cells (callus or organized tissues or organs put in culture, under controlled sterile conditions.

  18. Plant growth and cultivation.

    Science.gov (United States)

    Podar, Dorina

    2013-01-01

    There is a variety of methods used for growing plants indoor for laboratory research. In most cases plant research requires germination and growth of plants. Often, people have adapted plant cultivation protocols to the conditions and materials at hand in their own laboratory and growth facilities. Here I will provide a guide for growing some of the most frequently used plant species for research, i.e., Arabidopsis thaliana, barley (Hordeum vulgare) and rice (Oryza sativa). However, the methods presented can be used for other plant species as well, especially if they are related to the above-mentioned species. The presented methods include growing plants in soil, hydroponics, and in vitro on plates. This guide is intended as a starting point for those who are just beginning to work on any of the above-mentioned plant species. Methods presented are to be taken as suggestive and modification can be made according to the conditions existing in the host laboratory.

  19. Plant tissue culture techniques

    OpenAIRE

    Rolf Dieter Illg

    1991-01-01

    Plant cell and tissue culture in a simple fashion refers to techniques which utilize either single plant cells, groups of unorganized cells (callus) or organized tissues or organs put in culture, under controlled sterile conditions.

  20. On Plant Names.

    Science.gov (United States)

    Colton, Ronald W.

    1979-01-01

    Discusses the scientific and common names of numerous plants and the satisfaction children derive from mastering them. Includes drawings which illustrate the connections between plant structures and their names. (MA)

  1. Plant proton pumps

    DEFF Research Database (Denmark)

    Gaxiola, Roberto A.; Palmgren, Michael Gjedde; Schumacher, Karin

    2007-01-01

    Chemiosmotic circuits of plant cells are driven by proton (H+) gradients that mediate secondary active transport of compounds across plasma and endosomal membranes. Furthermore, regulation of endosomal acidification is critical for endocytic and secretory pathways. For plants to react to their co......Chemiosmotic circuits of plant cells are driven by proton (H+) gradients that mediate secondary active transport of compounds across plasma and endosomal membranes. Furthermore, regulation of endosomal acidification is critical for endocytic and secretory pathways. For plants to react...

  2. Randomized Clinical Trial of Anal Cushion Suture-fixation Comparing with Doppler-Guided Haemor-rhoid Artery Ligation for Grade III Haemorrhoids%肛垫缝扎修复术治疗III度痔的临床对照研究

    Institute of Scientific and Technical Information of China (English)

    翟敏; 巫益珍; 张永安; 李金德; 张旗; 周峰; 徐慧磊

    2015-01-01

    目的:探讨肛垫缝扎修复术治疗III度痔的疗效。方法:对100例III度痔患者随机分组,50例采用肛垫缝扎修复术(治疗组)治疗,50例采用超声多普勒痔动脉结扎术(DG-HAL,对照组)治疗,对两组疗效、并发症及患者满意度进行对比分析。结果:治疗组治愈率为86%,优于对照组的70%,(P<0.05);治疗组治疗费用为3138.09元,对照组为4020.43元(二者比较P<0.05)。随访24个月,治疗组痔脱垂(2.3%)及总体复发率(7.0%)低于对照组(19.0%,23.8%,P<0.05);治疗组患者认为“好”、“很好”者分别为42例(95.4%)、39例(90.7%),对照组分别为37例(88.9%)、32例(76.2%);两组术后疼痛、Wexner评分、继发出血、肛门不适等均具有较好的安全性(P>0.05)。结论:肛垫缝扎修复术与DG-HAL相比,能有效解除III度痔病症状,有效、经济、安全,具有更高的患者满意度。%Objective To investigate anal cushion suture-fixation operation in the treatment of grade III hem⁃orrhoids. Methods One hundred cases of grade III hemorrhoids were randomly divided into treatment group (anal cushion suture-fixation operation,50 cases)and control group(Doppler-guided hemorrhoidal artery ligation DG-HAL),50 cases.The clinical effects and complications were compared between the two groups. Results Cure rates were 86% in treatment group and 70% in the control(P0.05)in complications, in postoperative pain scores,Wexner scores,bleeding, and the anal discomfort. Conclusion Anal cushion suture-fixation operation is valid in eliminating symptoms induced by grade III hemorrhoids.It is effective, economical and with better sat⁃isfaction than by DG-HAL.

  3. Fundaments of plant cybernetics.

    Science.gov (United States)

    Zucconi, F

    2001-01-01

    A systemic approach is proposed for analyzing plants' physiological organization and cybernesis. To this end, the plant is inspected as a system, starting from the integration of crown and root systems, and its impact on a number of basic epigenetic events. The approach proves to be axiomatic and facilitates the definition of the principles behind the plant's autonomous control of growth and reproduction.

  4. Plants of the Bayshore.

    Science.gov (United States)

    Bachle, Leo; And Others

    This field guide gives pictures and descriptions of plants that can be found along the San Francisco Bayshore, especially along the Hayward shoreline. The plants are divided into three categories, those of the mud-flat zone, the drier zone, and the levee zone. Eighteen plants are represented in all. The guide is designed to be used alone, with an…

  5. Plant Diseases & Chemicals

    OpenAIRE

    Thompson, Sherm

    2008-01-01

    This course discusses the use of chemicals for plant disease control. Specifically, pesticides that can be used both in commercial or home/yard sitautions. This course also teaches how to determine plant diseases that may have caused a plant to die.

  6. Designing with plants

    NARCIS (Netherlands)

    Smits, R.

    2012-01-01

    This "designers' manual" is made during the TIDO-course AR0531 Smart & Bioclimatic Design. Rainforests are the lungs of the earth and plants can be the lungs of a buildings. Every plant uses CO2, water and light to produce sugars and oxygen; furthermore plants provide shade, take pollutants from th

  7. Plant Systems Biology (editorial)

    Science.gov (United States)

    In June 2003, Plant Physiology published an Arabidopsis special issue devoted to plant systems biology. The intention of Natasha Raikhel and Gloria Coruzzi, the two editors of this first-of-its-kind issue, was ‘‘to help nucleate this new effort within the plant community’’ as they considered that ‘‘...

  8. Power Plant Cycling Costs

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, N.; Besuner, P.; Lefton, S.; Agan, D.; Hilleman, D.

    2012-07-01

    This report provides a detailed review of the most up to date data available on power plant cycling costs. The primary objective of this report is to increase awareness of power plant cycling cost, the use of these costs in renewable integration studies and to stimulate debate between policymakers, system dispatchers, plant personnel and power utilities.

  9. Handbook of Plant Virology

    NARCIS (Netherlands)

    Khan, J.A.; Dijkstra, J.

    2006-01-01

    The Handbook of Plant Virology is a comprehensive guide to the terms and expressions commonly used in the study of plant virology, complete with descriptions of plant virus families down to the generic level. Rather than simply listing terms in alphabetical order, this unique book links each term to

  10. Diagnosing plant problems

    Science.gov (United States)

    Cheryl A. Smith

    2008-01-01

    Diagnosing Christmas tree problems can be a challenge, requiring a basic knowledge of plant culture and physiology, the effect of environmental influences on plant health, and the ability to identify the possible causes of plant problems. Developing a solution or remedy to the problem depends on a proper diagnosis, a process that requires recognition of a problem and...

  11. Iron stress in plants.

    Science.gov (United States)

    Connolly, Erin L; Guerinot, Mary

    2002-07-30

    Although iron is an essential nutrient for plants, its accumulation within cells can be toxic. Plants, therefore, respond to both iron deficiency and iron excess by inducing expression of different gene sets. Here, we review recent advances in the understanding of iron homeostasis in plants gained through functional genomic approaches

  12. Iron stress in plants

    OpenAIRE

    Connolly, Erin L.; Guerinot, Mary Lou

    2002-01-01

    Although iron is an essential nutrient for plants, its accumulation within cells can be toxic. Plants, therefore, respond to both iron deficiency and iron excess by inducing expression of different gene sets. Here, we review recent advances in the understanding of iron homeostasis in plants gained through functional genomic approaches.

  13. Recognizing plant defense priming

    NARCIS (Netherlands)

    Martinez-Medina, A.; Flors, V.; Heil, M.; Mauch-Mani, B.; Pieterse, C.M.J.; Pozo, M.J.; Ton, J.; Van Dam, N.M.; Conrath, U.

    2016-01-01

    Defense priming conditions diverse plant species for the superinduction of defense, often resulting in enhanced pest and disease resistance and abiotic stress tolerance. Here, we propose a guideline that might assist the plant research community in a consistent assessment of defense priming in plant

  14. Spatiotemporal drivers of dissolved organic matter in high alpine lakes: Role of Saharan dust inputs and bacterial activity

    Science.gov (United States)

    Mladenov, Natalie; Pulido-Villena, Elvira; Morales-Baquero, Rafael; Ortega-Retuerta, Eva; Sommaruga, Ruben; Reche, Isabel

    2010-01-01

    The effects of many environmental stressors such as UV radiation are mediated by dissolved organic matter (DOM) properties. Therefore, determining the factors shaping spatial and temporal patterns is particularly essential in the most susceptible, low dissolved organic carbon (DOC) lakes. We analyzed spatiotemporal variations in dissolved organic carbon concentration and dissolved organic matter optical properties (absorption and fluorescence) in 11 transparent lakes located above tree line in the Sierra Nevada Mountains (Spain), and we assessed potential external (evaporation and atmospheric deposition) and internal (bacterial abundance, bacterial production, chlorophyll a, and catchment vegetation) drivers of DOM patterns. At spatial and temporal scales, bacteria were related to chromophoric DOM (CDOM). At the temporal scale, water soluble organic carbon (WSOC) in dust deposition and evaporation were found to have a significant influence on DOC and CDOM in two Sierra Nevada lakes studied during the ice-free periods of 2000–2002. DOC concentrations and absorption coefficients at 320 nm were strongly correlated over the spatial scale (n = 11, R2 = 0.86; p < 0.01), but inconsistently correlated over time, indicating seasonal and interannual variability in external factors and a differential response of DOC concentration and CDOM to these factors. At the continental scale, higher mean DOC concentrations and more CDOM in lakes of the Sierra Nevada than in lakes of the Pyrenees and Alps may be due to a combination of more extreme evaporation, and greater atmospheric dust deposition. PMID:20582227

  15. Historic records of organic aerosols from a high Alpine glacier: implications of biomass burning, anthropogenic emissions, and dust transport

    Directory of Open Access Journals (Sweden)

    C. Müller-Tautges

    2015-05-01

    Full Text Available Historic records of α-dicarbonyls (glyoxal, methylglyoxal, carboxylic acids (C6–C12 dicarboxylic acids, pinic acid, p-hydroxybenzoic acid, phthalic acid, 4-methylphthalic acid, and major ions (oxalate, formate, calcium were determined with annual resolution in an ice core from Grenzgletscher in the southern Swiss Alps, covering the time period from 1942 to 1993. Measurements were conducted using ultra-high performance liquid chromatography (UHPLC coupled to electrospray ionization high resolution mass spectrometry (ESI-HRMS. For the first time, long-term records of the carboxylic acids and dicarbonyls as well as their source apportionment are reported for Western Europe. Source assignment of the organic species present in the ice core was performed using principal component analysis. Our results suggest biomass burning, anthropogenic emissions, and transport of mineral dust to be the main parameters influencing the concentration of organic compounds. Ice core records of several highly correlated compounds (e.g. p-hydroxybenzoic acid, pinic acid, C7 and C8 dicarboxylic acids can be related to the forest fire history in southern Switzerland. P-hydroxybenzoic acid was found to be the best organic fire tracer in the study area, revealing the highest correlation with the burned area from fires. Historical records of methylglyoxal, phthalic acid, and dicarboxylic acids C6, C10, and C12 are comparable with that of anthropogenic emissions of volatile organic compounds (VOCs. The small organic acids oxalic acid and formic acid are both highly correlated with calcium, suggesting their records to be affected by changing mineral dust transport to the drilling site.

  16. Instability of a highly vulnerable high alpine rock ridge: the lower Arête des Cosmiques (Mont Blanc massif, France)

    Science.gov (United States)

    Ravanel, L.; Deline, P.; Lambiel, C.; Vincent, C.

    2012-04-01

    Glacier retreat and permafrost degradation are actually more and more thought to explain the increasing instability of rock slopes and rock ridges in high mountain environments. Hot summers with numerous rockfalls we experienced over the last two decades in the Alps have indeed contributed to test/strengthen the hypothesis of a strong correlation between rockfalls and global warming through these two cryospheric factors. Rockfalls from recently deglaciated and/or thawing areas may have very important economic and social implications for high mountain infrastructures and be a fatal hazard for mountaineers. At high mountain sites characterized by infrastructures that can be affected by rockfalls, the monitoring of rock slopes, permafrost and glaciers is thus an essential element for the sustainability of the infrastructure and for the knowledge/management of risks. Our study focuses on a particularly active area of the Mont Blanc massif (France), the lower Arête des Cosmiques, on which is located the very popular Refuge des Cosmiques (3613 m a.s.l.). Since 1998, when a rockfall threatened a part of the refuge and forced to major stabilizing works, observations allowed to identify 10 detachments (20 m3 to > 1000 m3), especially on the SE face of the ridge. Since 2009, this face is yearly surveyed by terrestrial laser scanning to obtain high-resolution 3D models. Their diachronic comparison gives precise measurements of the evolution of the rock slope. Eight rock detachments have thus been documented (0.7 m3 to 256.2 m3). Rock temperature measurements at the ridge and the close Aiguille du Midi (3842 m a.s.l.), and observations of the evolution of the underlying Glacier du Géant have enable to better understand the origin of the strong dynamics of this highly vulnerable area: (i) rock temperature data suggest the presence of warm permafrost (i.e. close to 0°C) from the first meters to depth in the SE face, and cold permafrost in the NW face; (ii) as suggested by the occurrence of rockfalls mainly during or at the end of hot periods in summer, degradation of the cleft ice - observed in several rockfall scars - has likely participated in the triggering of several if not all of these rockfalls; (iii) alternation of the ice content increase during segregation phases and its decrease during the summer periods has probably modified the geotechnical properties of the rock mass, especially since rockfalls have mostly been triggered in the active layer; (iv) evolution of the glacier have also directly interfered with the stability of the SE face of the ridge: rockfalls at the foot of the rockslopes were only possible because of the lowering of the glacier in the recent years. Rockfalls that occurred at the lower Arête des Cosmiques thus probably result from the combination between permafrost activity/degradation and glacier shrinkage.

  17. Age and growth of the sand lizards (Lacerta agilis from a high Alpine population of north-western Italy

    Directory of Open Access Journals (Sweden)

    Fabio M. Guarino

    2010-07-01

    Full Text Available We studied growth and longevity of Lacerta agilis from a sample (34 adults and 2 small-sized juveniles of a population living at high altitude in north-western Italy using skeletochronological method. Snout vent length (SVL mean of males did not significantly differ from that of females although the latter were in average bigger (SVL ± SD, males: 69.3 ± 7.1 mm, n = 11; females: 73.9 ± 9.7 mm, n = 22; Mann-Whitney U-test, U = 1.76, P = 0.077. Age ranged from 2 to 4 years (mean age ± SD = 2.3 ± 0.2 in males and from 2 to 3 years in females (mean age ± SD = 2.59 ± 0.5 years. Age mean did not significantly differ between the sexes (Mann-Whitney U-test, U = 1.35, P = 0.174. The two juveniles were 30 and 32 mm in SVL and both were 1-2 months old. In both sexes, a significant positive correlation between SVL and age was recorded although weakly significant for males (Spearman’s correlation coefficient, males: rs = 0.70, P = 0.05; females: rs = 0.75, P < 0.001. Von Bertalanffy growth curves well fitted to the relationships between age and SVL and showed a different profile between males (asymptotics size, SVLmax = 81.9 mm; growth coefficient, k = 0.63 and females (SVLmax = 100 mm; k = 0.40. Results indicate that individuals of L. agilis studied by us are short-living when compared with other populations of the same species.

  18. Linking two thousand years of European historical records with environmental change recorded in a high Alpine ice core

    Science.gov (United States)

    Bohleber, Pascal; Spaulding, Nicole; Mayewski, Paul; Kurbatov, Andrei; Hoffmann, Helene; Erhardt, Tobias; Fischer, Hubertus; More, Alexander; Loveluck, Christopher; Luongo, Matthew; Kabala, Jakub; McCormick, Michael

    2016-04-01

    Its extraordinary network of historical and archaeological records makes Europe exceptionally promising for investigating environmental change and human response over the last two thousand years. Among natural proxy archives, ice core records offer a wide range of environmental reconstructions including natural and human source histories of the chemistry of the atmosphere. To link these robust environmental records with historical evidence of past civilizations remains a great challenge, however. In central Europe the unique target for a comparison for environmental change recorded in ice cores and human activity is the small firn saddle of Colle Gnifetti (4550 m above sea level on the Italian-Swiss border). Its exceptionally low net accumulation make Colle Gnifetti (CG) the only feasible site in the Alps for retrieving a long-term ice core record beyond the last century. However, at CG rapid annual layer thinning eventually limits conventional cm-resolution analysis to multi-annual signals and hampers dating by annual layer counting beyond a few hundred years. Thereby, a crucial gap is introduced to the sub-seasonal time scale of events typically recorded in written archives. In our ongoing project we pioneer correlating the CG environmental ice core archive with a unique compilation of European historical records provided through the Harvard Initiative for the Science of the Human Past and the Digital Atlas of Roman and Medieval Civilization. For this purpose, state-of-the-art glacio-chemical analysis was performed on a newly recovered CG ice core, including continuous flow analysis chemistry and stable isotopes. A crucial contribution comes from the application of LA-ICP-MS (laser ablation ion coupled plasma mass spectrometry) to meter long sections of frozen ice samples, developed and operated by the University of Maine's Climate Change Institute, offering glacio-chemical records up to 100 μm in resolution. The new methods significantly improves sampling resolution and allows detection of annual layers even in highly compressed old sections of CG ice cores: A breakthrough not only for extending the ice core dating over the last two millennia but also for bridging the gap in time scales to historical records. Here we present first results from our ongoing efforts in bringing together ice core time series with historical evidence, focusing on the time period from 1 to 1400 C.E. Based on a thorough consideration of the glaciological constraints at CG we explore various ice core proxy signals for their significance to correlate with events recorded in human writing, such as dust storms, volcanic events, climate-induced crop failures and starvation as well as metal production levels. Distinct dust layers are frequently found in CG ice cores, representative for meteorological conditions that transported sand from the Sahara to Europe. At the same time, Saharan dust events were also frequently recorded by ancient and medieval observers as "blood rain". Ultimately we work towards using past extreme climate events from medieval Europe recorded as written evidence to constrain the ice core age scale and, vice versa, to investigate the response of human societies to environmental change recorded in the CG glacier archive.

  19. Bacterial GDGTs in Holocene sediments and catchment soils of a high Alpine lake: application of the MBT/CBT-paleothermometer

    NARCIS (Netherlands)

    Niemann, H.; Stadnitskaia, A.; Wirth, S.B.; Gilli, A.; Anselmetti, F.S.; Sinninghe Damsté, J.S.S.; Schouten, S.; Hopmans, E.C.; Lehmann, M.F.

    2012-01-01

    A novel proxy for continental mean annual air temperature (MAAT) and soil pH, the MBT/CBT-paleothermometer, is based on the temperature (T) and pH-dependent distribution of specific bacterial membrane lipids (branched glycerol dialkyl glycerol tetraethers - GDGTs) in soil organic matter. Here, we te

  20. Historic records of organic compounds from a high Alpine glacier: influences of biomass burning, anthropogenic emissions, and dust transport

    Science.gov (United States)

    Müller-Tautges, C.; Eichler, A.; Schwikowski, M.; Pezzatti, G. B.; Conedera, M.; Hoffmann, T.

    2016-01-01

    Historic records of α-dicarbonyls (glyoxal, methylglyoxal), carboxylic acids (C6-C12 dicarboxylic acids, pinic acid, p-hydroxybenzoic acid, phthalic acid, 4-methylphthalic acid), and ions (oxalate, formate, calcium) were determined with annual resolution in an ice core from Grenzgletscher in the southern Swiss Alps, covering the time period from 1942 to 1993. Chemical analysis of the organic compounds was conducted using ultra-high-performance liquid chromatography (UHPLC) coupled to electrospray ionization high-resolution mass spectrometry (ESI-HRMS) for dicarbonyls and long-chain carboxylic acids and ion chromatography for short-chain carboxylates. Long-term records of the carboxylic acids and dicarbonyls, as well as their source apportionment, are reported for western Europe. This is the first study comprising long-term trends of dicarbonyls and long-chain dicarboxylic acids (C6-C12) in Alpine precipitation. Source assignment of the organic species present in the ice core was performed using principal component analysis. Our results suggest biomass burning, anthropogenic emissions, and transport of mineral dust to be the main parameters influencing the concentration of organic compounds. Ice core records of several highly correlated compounds (e.g., p-hydroxybenzoic acid, pinic acid, pimelic, and suberic acids) can be related to the forest fire history in southern Switzerland. P-hydroxybenzoic acid was found to be the best organic fire tracer in the study area, revealing the highest correlation with the burned area from fires. Historical records of methylglyoxal, phthalic acid, and dicarboxylic acids adipic acid, sebacic acid, and dodecanedioic acid are comparable with that of anthropogenic emissions of volatile organic compounds (VOCs). The small organic acids, oxalic acid and formic acid, are both highly correlated with calcium, suggesting their records to be affected by changing mineral dust transport to the drilling site.

  1. PHYLOGENETIC POSITION OF ZYGOGONIUM ERICETORUM (ZYGNEMATOPHYCEAE, CHAROPHYTA) FROM A HIGH ALPINE HABITAT AND ULTRASTRUCTURAL CHARACTERIZATION OF UNUSUAL APLANOSPORES

    Science.gov (United States)

    Stancheva, Rosalina; Hall, John D.; Herburger, Klaus; Lewis, Louise A.; McCourt, Richard M.; Sheath, Robert G.; Holzinger, Andreas

    2015-01-01

    Zygogonium ericetorum, the type species of the genus, was studied from a natural population collected in Mt. Schönwieskopf, Tyrol, Austria. Generic concepts of Zygogonium and Zygnema were tested with atpB, psbC, and rbcL gene sequence analysis, which showed a sister relationship between Z. ericetorum and Mesotaenium, in an early branching clade sister to a grouping of Zygnema and several other filamentous and unicellular zygnematalean taxa. A variety of light, confocal, transmission electron microscopy, and cytochemical techniques provided new data on the variable chloroplast shape of Z. ericetorum, and its aplanospore structure and development, which has been previously considered taxonomically important but has been ambiguously interpreted. Zygogonium can be distinguished from other zygnematophytes (particularly Zygnema), based on the combination of two characters: (i) irregular, compressed plate-like chloroplasts and (ii) residual cytoplasmic content left in sporangia outside of the fully developed aplanospores or zygospores. The presence of a sporangial wall that separates the spores from the parent cell should be excluded from the definition of Zygogonium, because it is also observed in Zygnema. Similarly, the ecological characterization of Zygogonium as acidophilic is not unique to the genus. The names of 18 species currently belonging to Zygogonium are here changed to Zygnema, because of incompatibility with this new proposed Zygogonium concept. In the species transferred to Zygnema, chloroplasts are typically stellate in three-dimensions, and the entire content of fertile cells is transformed into the spore, so there is no cytoplasmic residue. PMID:25810560

  2. I. Identification and characterization of dasheen mosaic virus in Chinese evergreen plants (Aglaonema commutatum) in California. II. New approaches for detecting plant viruses

    Energy Technology Data Exchange (ETDEWEB)

    Kositratana, W.

    1985-01-01

    Chinese evergreen plants (Aglaonema commutatum) with symptoms of mild stunting, chlorosis, leaf distortion and mosaic, were observed in Southern California. Flexuous rods (ca. 750 nm) were detected in leaf dip and partially purified preparations. Dasheen mosac virus (DMV) was identified as the causal agent on the basis of host range, morphology and reaction with DMV antiserum in immunodouble diffusion and immunosorbent electron microscopy (ISEM) tests. Tetragonia expansa was found to be a new host of this virus. Surveys indicate that DMV is not widespread in cultivars of A. commutatum in Southern California. The virus was purified from leaves of seedling Philodendron selloum by clarification with CCl/sub 4/, CHCl/sub 3/, and Triton X-100, precipitation with PEG-8000 and centrifugation in either Cs/sub 2/SO/sub 4/-sucrose cushion gradients or Cs/sub 2/SO/sub 4/ equilibrium density gradients. Purified virions formed a single UV-absorbing infectious band with densities of 1.31 and 1.245 g/ml in CsCl/sub 2/ and Cs/sub 2/SO/sub 4/ equilibrium density gradients, respectively, and a sedimentation coefficient of 154 S as determined by a linear-log sucrose density gradient centrifugation. Dasheen mosaic virus has a plus-sense ssRNA with the M.W. of 3.2 x 10/sup 6/ under denaturing conditions. Molecular hybridization analysis using /sup 3/H-complementary DNA specific to DMV-Ca RNA showed that DMV-Ca isolate was more closely related to DMV-Fiji isolate than to DMV-Fla isolate, and was very distantly related to ZYMV, TEV. PeMoC and PVY.

  3. Plant Physiology and Development

    DEFF Research Database (Denmark)

    Taiz, Lincoln; Zeiger, Eduardo; Møller, Ian Max

    Physiology and Development. As before, Unit III begins with updated chapters on Cell Walls and Signals and Signal Transduction. The latter chapter has been expanded to include a discussion of major signaling molecules, such as calcium ions and plant hormones. A new, unified chapter entitled Signals from......Throughout its twenty-two year history, the authors of Plant Physiology have continually updated the book to incorporate the latest advances in plant biology and implement pedagogical improvements requested by adopters. This has made Plant Physiology the most authoritative, comprehensive......, and widely used upper-division plant biology textbook. In the Sixth Edition, the Growth and Development section (Unit III) has been reorganized and expanded to present the complete life cycle of seed plants from germination to senescence. In recognition of this enhancement, the text has been renamed Plant...

  4. Multinationals and plant survival

    DEFF Research Database (Denmark)

    Bandick, Roger

    2010-01-01

    The aim of this paper is twofold: first, to investigate how different ownership structures affect plant survival, and second, to analyze how the presence of foreign multinational enterprises (MNEs) affects domestic plants’ survival. Using a unique and detailed data set on the Swedish manufacturing...... sector, I am able to separate plants into those owned by foreign MNEs, domestic MNEs, exporting non-MNEs, and purely domestic firms. In line with previous findings, the result, when conditioned on other factors affecting survival, shows that foreign MNE plants have lower survival rates than non......-MNE plants. However, separating the non-MNEs into exporters and non-exporters, the result shows that foreign MNE plants have higher survival rates than non-exporting non-MNEs, while the survival rates of foreign MNE plants and exporting non-MNE plants do not seem to differ. Moreover, the simple non...

  5. Pharming and transgenic plants.

    Science.gov (United States)

    Liénard, David; Sourrouille, Christophe; Gomord, Véronique; Faye, Loïc

    2007-01-01

    Plant represented the essence of pharmacopoeia until the beginning of the 19th century when plant-derived pharmaceuticals were partly supplanted by drugs produced by the industrial methods of chemical synthesis. In the last decades, genetic engineering has offered an alternative to chemical synthesis, using bacteria, yeasts and animal cells as factories for the production of therapeutic proteins. More recently, molecular farming has rapidly pushed towards plants among the major players in recombinant protein production systems. Indeed, therapeutic protein production is safe and extremely cost-effective in plants. Unlike microbial fermentation, plants are capable of carrying out post-translational modifications and, unlike production systems based on mammalian cell cultures, plants are devoid of human infective viruses and prions. Furthermore, a large panel of strategies and new plant expression systems are currently developed to improve the plant-made pharmaceutical's yields and quality. Recent advances in the control of post-translational maturations in transgenic plants will allow them, in the near future, to perform human-like maturations on recombinant proteins and, hence, make plant expression systems suitable alternatives to animal cell factories.

  6. Safe genetically engineered plants

    Science.gov (United States)

    Rosellini, D.; Veronesi, F.

    2007-10-01

    The application of genetic engineering to plants has provided genetically modified plants (GMPs, or transgenic plants) that are cultivated worldwide on increasing areas. The most widespread GMPs are herbicide-resistant soybean and canola and insect-resistant corn and cotton. New GMPs that produce vaccines, pharmaceutical or industrial proteins, and fortified food are approaching the market. The techniques employed to introduce foreign genes into plants allow a quite good degree of predictability of the results, and their genome is minimally modified. However, some aspects of GMPs have raised concern: (a) control of the insertion site of the introduced DNA sequences into the plant genome and of its mutagenic effect; (b) presence of selectable marker genes conferring resistance to an antibiotic or an herbicide, linked to the useful gene; (c) insertion of undesired bacterial plasmid sequences; and (d) gene flow from transgenic plants to non-transgenic crops or wild plants. In response to public concerns, genetic engineering techniques are continuously being improved. Techniques to direct foreign gene integration into chosen genomic sites, to avoid the use of selectable genes or to remove them from the cultivated plants, to reduce the transfer of undesired bacterial sequences, and make use of alternative, safer selectable genes, are all fields of active research. In our laboratory, some of these new techniques are applied to alfalfa, an important forage plant. These emerging methods for plant genetic engineering are briefly reviewed in this work.

  7. Toxic proteins in plants.

    Science.gov (United States)

    Dang, Liuyi; Van Damme, Els J M

    2015-09-01

    Plants have evolved to synthesize a variety of noxious compounds to cope with unfavorable circumstances, among which a large group of toxic proteins that play a critical role in plant defense against predators and microbes. Up to now, a wide range of harmful proteins have been discovered in different plants, including lectins, ribosome-inactivating proteins, protease inhibitors, ureases, arcelins, antimicrobial peptides and pore-forming toxins. To fulfill their role in plant defense, these proteins exhibit various degrees of toxicity towards animals, insects, bacteria or fungi. Numerous studies have been carried out to investigate the toxic effects and mode of action of these plant proteins in order to explore their possible applications. Indeed, because of their biological activities, toxic plant proteins are also considered as potentially useful tools in crop protection and in biomedical applications, such as cancer treatment. Genes encoding toxic plant proteins have been introduced into crop genomes using genetic engineering technology in order to increase the plant's resistance against pathogens and diseases. Despite the availability of ample information on toxic plant proteins, very few publications have attempted to summarize the research progress made during the last decades. This review focuses on the diversity of toxic plant proteins in view of their toxicity as well as their mode of action. Furthermore, an outlook towards the biological role(s) of these proteins and their potential applications is discussed.

  8. Plant Communities of Rough Rock.

    Science.gov (United States)

    Jacobs, Linda

    A unit of study on plants grown in the Navajo community of Rough Rock, Arizona, is presented in sketches providing the common Navajo name for the plant, a literal English translation, the English name of the plant, and the Latin name. A brief description of each plant includes where the plant grows, how the Navajos use the plant, and the color and…

  9. Conditional sterility in plants

    Science.gov (United States)

    Meagher, Richard B.; McKinney, Elizabeth; Kim, Tehryung

    2010-02-23

    The present disclosure provides methods, recombinant DNA molecules, recombinant host cells containing the DNA molecules, and transgenic plant cells, plant tissue and plants which contain and express at least one antisense or interference RNA specific for a thiamine biosynthetic coding sequence or a thiamine binding protein or a thiamine-degrading protein, wherein the RNA or thiamine binding protein is expressed under the regulatory control of a transcription regulatory sequence which directs expression in male and/or female reproductive tissue. These transgenic plants are conditionally sterile; i.e., they are fertile only in the presence of exogenous thiamine. Such plants are especially appropriate for use in the seed industry or in the environment, for example, for use in revegetation of contaminated soils or phytoremediation, especially when those transgenic plants also contain and express one or more chimeric genes which confer resistance to contaminants.

  10. Plant synthetic biology.

    Science.gov (United States)

    Liu, Wusheng; Stewart, C Neal

    2015-05-01

    Plant synthetic biology is an emerging field that combines engineering principles with plant biology toward the design and production of new devices. This emerging field should play an important role in future agriculture for traditional crop improvement, but also in enabling novel bioproduction in plants. In this review we discuss the design cycles of synthetic biology as well as key engineering principles, genetic parts, and computational tools that can be utilized in plant synthetic biology. Some pioneering examples are offered as a demonstration of how synthetic biology can be used to modify plants for specific purposes. These include synthetic sensors, synthetic metabolic pathways, and synthetic genomes. We also speculate about the future of synthetic biology of plants.

  11. Risk-taking plants

    Science.gov (United States)

    Sade, Nir; Gebremedhin, Alem; Moshelion, Menachem

    2012-01-01

    Water scarcity is a critical limitation for agricultural systems. Two different water management strategies have evolved in plants: an isohydric strategy and an anisohydric strategy. Isohydric plants maintain a constant midday leaf water potential (Ψleaf) when water is abundant, as well as under drought conditions, by reducing stomatal conductance as necessary to limit transpiration. Anisohydric plants have more variable Ψleaf and keep their stomata open and photosynthetic rates high for longer periods, even in the presence of decreasing leaf water potential. This risk-taking behavior of anisohydric plants might be beneficial when water is abundant, as well as under moderately stressful conditions. However, under conditions of intense drought, this behavior might endanger the plant. We will discuss the advantages and disadvantages of these two water-usage strategies and their effects on the plant’s ability to tolerate abiotic and biotic stress. The involvement of plant tonoplast AQPs in this process will also be discussed. PMID:22751307

  12. Annual Plant Reviews

    DEFF Research Database (Denmark)

    , three dimensional structures and functions of each protein in a biological system. In plant science, the number of proteome studies is rapidly expanding after the completion of the Arabidopsis thaliana genome sequence, and proteome analyses of other important or emerging model systems and crop plants...... are in progress or are being initiated. Proteome analysis in plants is subject to the same obstacles and limitations as in other organisms, but the nature of plant tissues, with their rigid cell walls and complex variety of secondary metabolites, means that extra challenges are involved that may not be faced when...... analysing other organisms. This volume aims to highlight the ways in which proteome analysis has been used to probe the complexities of plant biochemistry and physiology. It is aimed at researchers in plant biochemistry, genomics, transcriptomics and metabolomics who wish to gain an up-to-date insight...

  13. Recombinant Cytokines from Plants

    OpenAIRE

    Patrycja Redkiewicz; Anna Góra-Sochacka; Tomas Vaněk; Agnieszka Sirko

    2011-01-01

    Plant-based platforms have been successfully applied for the last two decades for the efficient production of pharmaceutical proteins. The number of commercialized products biomanufactured in plants is, however, rather discouraging. Cytokines are small glycosylated polypeptides used in the treatment of cancer, immune disorders and various other related diseases. Because the clinical use of cytokines is limited by high production costs they are good candidates for plant-made pharmaceuticals. S...

  14. MBS Native Plant Communities

    Data.gov (United States)

    Minnesota Department of Natural Resources — This data layer contains results of the Minnesota County Biological Survey (MCBS). It includes polygons representing the highest quality native plant communities...

  15. The Kuroshio power plant

    CERN Document Server

    Chen, Falin

    2013-01-01

    By outlining a new design or the Kuroshio power plant, new approaches to turbine design, anchorage system planning, deep sea marine engineering and power plant operations and maintenance are explored and suggested. The impact on the local environment, particularly in the face of natural disasters, is also considered to provide a well rounded introduction to plan and build a 30MW pilot power plant. Following a literature review, the six chapters of this book propose a conceptual design by focusing on the plant's core technologies and establish the separate analysis logics for turbine design and

  16. Plant Habitat (PH)

    Science.gov (United States)

    Onate, Bryan

    2016-01-01

    The International Space Station (ISS) will soon have a platform for conducting fundamental research of Large Plants. Plant Habitat (PH) is designed to be a fully controllable environment for high-quality plant physiological research. PH will control light quality, level, and timing, temperature, CO2, relative humidity, and irrigation, while scrubbing ethylene. Additional capabilities include leaf temperature and root zone moisture and oxygen sensing. The light cap will have red (630 nm), blue (450 nm), green (525 nm), far red (730 nm) and broad spectrum white LEDs. There will be several internal cameras (visible and IR) to monitor and record plant growth and operations.

  17. Plant Transporter Identification

    DEFF Research Database (Denmark)

    Larsen, Bo

    Membrane transport proteins (transporters) play a critical role for numerous biological processes, by controlling the movements of ions and molecules in and out of cells. In plants, transporters thus function as gatekeepers between the plant and its surrounding environment and between organs......, tissues, cells and intracellular compartments. Since plants are highly compartmentalized organisms with complex transportation infrastructures, they consequently have many transporters. However, the vast majority of predicted transporters have not yet been experimentally verified to have transport...... activity. This project contains a review of the implemented methods, which have led to plant transporter identification, and present our progress on creating a high-throughput functional genomics transporter identification platform....

  18. Plant intelligence and attention.

    Science.gov (United States)

    Marder, Michael

    2013-05-01

    This article applies the phenomenological model of attention to plant monitoring of environmental stimuli and signal perception. Three complementary definitions of attention as selectivity, modulation and perdurance are explained with reference to plant signaling and behaviors, including foraging, ramet placement and abiotic stress communication. Elements of animal and human attentive attitudes are compared with plant attention at the levels of cognitive focus, context and margin. It is argued that the concept of attention holds the potential of becoming a cornerstone of plant intelligence studies.

  19. Plant Transporter Identification

    DEFF Research Database (Denmark)

    Larsen, Bo

    Membrane transport proteins (transporters) play a critical role for numerous biological processes, by controlling the movements of ions and molecules in and out of cells. In plants, transporters thus function as gatekeepers between the plant and its surrounding environment and between organs......, tissues, cells and intracellular compartments. Since plants are highly compartmentalized organisms with complex transportation infrastructures, they consequently have many transporters. However, the vast majority of predicted transporters have not yet been experimentally verified to have transport...... activity. This project contains a review of the implemented methods, which have led to plant transporter identification, and present our progress on creating a high-throughput functional genomics transporter identification platform....

  20. Explosive Formulation Pilot Plant

    Data.gov (United States)

    Federal Laboratory Consortium — The Pilot Plant for Explosive Formulation supports the development of new explosives that are comprised of several components. This system is particularly beneficial...

  1. Phyllotactic Patterns on Plants

    Science.gov (United States)

    Shipman, Patrick D.; Newell, Alan C.

    2004-04-01

    We demonstrate how phyllotaxis (the arrangement of leaves on plants) and the deformation configurations seen on plant surfaces may be understood as the energy-minimizing buckling pattern of a compressed shell (the plant's tunica) on an elastic foundation. The key new idea is that the strain energy is minimized by configurations consisting of special triads of almost periodic deformations. We reproduce a wide spectrum of plant patterns, all with the divergence angles observed in nature, and show how the occurrences of Fibonacci-like sequences and the golden angle are natural consequences.

  2. Oil from plants

    Science.gov (United States)

    Calvin, M.

    1983-01-01

    As a result of the exhaustion of our supplies of ancient photosynthesis (oil and gas) it is necessary to develop renewable fuels for the future. The most immediate source of renewable fuel is, of course, the annually growing green plants, some of which produce hydrocarbon(s) directly. New plant sources can be selected for this purpose, plants which have high potential for production of chemicals and liquid fuels. Suggestions are made for modification of both the product character and the productivity of the plants. Ultimately, a totally synthetic device will be developed for the conversion of solar quanta into useful chemical form completely independent of the need for arable land.

  3. Plant biotic interactions

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    occurring after infestation by olive fly larvae. The last research article by Niu et al.(2016) describes a growth-promoting rhizobacterium that primes induced systemic resistance by suppressing a host R gene-targeting micro RNA pairs and activating host immune responses. This finding further supports the important roles of plant endogenous small RNAs in plant-pathogen interactions. Hailing Jin, Professor Special Issue Editor UC President’s Chair Director of Genetics, Genomics and Bioinformatics Graduate Program, Center for Plant Cell Biology, Institute for Integrative Genome Biology, University of California, Riverside, USA doi:10.1111/jipb.12476 ©2016 Institute of Botany, Chinese Academy of Sciences REFERENCES Alagna F, Kal enbach M, Pompa A, De Marchis F, Rao R, Baldwin IT, Bonaventure G, Baldoni L (2016) Olive fruits infested with olive fly larvae respond with an ethylene burst and the emission of specific volatiles. J Integr Plant Biol 58:413–425 Castiblanco LF, Sundin GW (2016) New insights on molecular regulation of biofilm formation in plant-associated bacteria. J Integr Plant Biol 58:362–372 da GraSca JV, Douhan GW, Halbert SE, Keremane ML, Lee RF, Vidalakis G, Zhao H (2016) Huanglongbing: An overview of a complex pathosystem ravaging the world’s citrus. J Integr Plant Biol 58:373–387 Giovino A, Martinel i F, Saia S (2016) Rhynchophorus ferrugineus attack affects a group of compounds rather than rearranging Phoenix canariensis metabolic pathways. J Integr Plant Biol 58:388–396 Huang J, Yang M, Zhang X (2016) The function of smal RNAs in plant biotic stress response. J Integr Plant Biol 58:312–327 Kaloshian I, Wal ing LL (2016) Hemipteran and dipteran pests: Effectors and plant host immune regulators. J Integr Plant Biol 58:350–361 Mermigka G, Verret F, Kalantidis K (2016) RNA silencing movement in plants. J Integr Plant Biol 58:328–342 Niu D, Xia J, Jiang C, Qi B, Ling X, Lin S, Zhang W, Guo J, Jin H, Zhao H (2016) Bacil us cereus AR156

  4. MRI of intact plants.

    NARCIS (Netherlands)

    As, H. van; Scheenen, T.W.J.; Vergeldt, F.J.

    2009-01-01

    Nuclear magnetic resonance imaging (MRI) is a non-destructive and non-invasive technique that can be used to acquire two- or even three-dimensional images of intact plants. The information within the images can be manipulated and used to study the dynamics of plant water relations and water transpor

  5. MRI of intact plants

    NARCIS (Netherlands)

    As, van H.; Scheenen, T.; Vergeldt, F.J.

    2009-01-01

    Nuclear magnetic resonance imaging (MRI) is a non-destructive and non-invasive technique that can be used to acquire two- or even three-dimensional images of intact plants. The information within the images can be manipulated and used to study the dynamics of plant water relations and water transpor

  6. Modulating lignin in plants

    Science.gov (United States)

    Apuya, Nestor; Bobzin, Steven Craig; Okamuro, Jack; Zhang, Ke

    2013-01-29

    Materials and methods for modulating (e.g., increasing or decreasing) lignin content in plants are disclosed. For example, nucleic acids encoding lignin-modulating polypeptides are disclosed as well as methods for using such nucleic acids to generate transgenic plants having a modulated lignin content.

  7. Plant vascular development

    NARCIS (Netherlands)

    Rybel, De Bert; Mähönen, Ari Pekka; Helariutta, Yrjö; Weijers, Dolf

    2016-01-01

    Vascular tissues in plants are crucial to provide physical support and to transport water, sugars and hormones and other small signalling molecules throughout the plant. Recent genetic and molecular studies have identified interconnections among some of the major signalling networks that regulate

  8. Nuclear Power Plants. Revised.

    Science.gov (United States)

    Lyerly, Ray L.; Mitchell, Walter, III

    This publication is one of a series of information booklets for the general public published by the United States Atomic Energy Commission. Among the topics discussed are: Why Use Nuclear Power?; From Atoms to Electricity; Reactor Types; Typical Plant Design Features; The Cost of Nuclear Power; Plants in the United States; Developments in Foreign…

  9. NMR, Water and Plants

    NARCIS (Netherlands)

    As, van H.

    1982-01-01

    This Thesis describes the application of a non-destructive pulsed proton NMR method mainly to measure water transport in the xylem vessels of plant stems and in some model systems. The results are equally well applicable to liquid flow in other biological objects than plants, e.g. flow of blood and

  10. Terrestrial plant methane production

    DEFF Research Database (Denmark)

    Mikkelsen, Teis Nørgaard; Bruhn, Dan; Møller, Ian M.

    We evaluate all experimental work published on the phenomenon of aerobic methane (CH4) generation in terrestrial plants. We conclude that the phenomenon is true. Four stimulating factors have been observed to induce aerobic plant CH4 production, i.e. cutting injuries, increasing temperature...

  11. Slavery in plants

    NARCIS (Netherlands)

    Kabiri, S.; Rodenburg, J.; Ast, van A.; Bastiaans, L.

    2017-01-01

    The rain-fed lowland rice weed Rhamphicarpa fistulosa (Rice Vampireweed) is a facultative root parasitic plant. Growth and reproduction of R. fistulosa benefit considerably from parasitism, but how this affects the host plant is not well established. We determined accumulation and partitioning of

  12. Carotenoid metabolism in plants

    Science.gov (United States)

    Carotenoids are mostly C40 terpenoids, a class of hydrocarbons that participate in various biological processes in plants, such as photosynthesis, photomorphogenesis, photoprotection, and development. Carotenoids also serve as precursors for two plant hormones and a diverse set of apocarotenoids. Th...

  13. Overview of plant pigments

    Science.gov (United States)

    Chlorophylls, carotenoids, flavonoids and betalains are four major classes of biological pigments produced in plants. Chlorophylls are the primary pigments responsible for plant green and photosynthesis. The other three are accessary pigments and secondary metabolites that yield non-green colors and...

  14. Plant pathogen resistance

    Science.gov (United States)

    Greenberg, Jean T; Jung, Ho Won; Tschaplinski, Timothy

    2012-11-27

    Azelaic acid or its derivatives or analogs induce a robust and a speedier defense response against pathogens in plants. Azelaic acid treatment alone does not induce many of the known defense-related genes but activates a plant's defense signaling upon pathogen exposure.

  15. [Neotropical plant morphology].

    Science.gov (United States)

    Pérez-García, Blanca; Mendoza, Aniceto

    2002-01-01

    An analysis on plant morphology and the sources that are important to the morphologic interpretations is done. An additional analysis is presented on all published papers in this subject by the Revista de Biología Tropical since its foundation, as well as its contribution to the plant morphology development in the neotropics.

  16. The Plant Cell Surface

    Institute of Scientific and Technical Information of China (English)

    Anne-Mie C.Emons; Kurt V.Fagerstedt

    2010-01-01

    @@ Multicellular organization and tissue construction has evolved along essentially different lines in plants and animals. Since plants do not run away, but are anchored in the soil, their tissues are more or less firm and stiff. This strength stems from the cell walls, which encase the fragile cytoplasm, and protect it.

  17. Plant development models

    NARCIS (Netherlands)

    Chuine, I.; Garcia de Cortazar-Atauri, I.; Kramer, K.; Hänninen, H.

    2013-01-01

    In this chapter we provide a brief overview of plant phenology modeling, focusing on mechanistic phenological models. After a brief history of plant phenology modeling, we present the different models which have been described in the literature so far and highlight the main differences between them,

  18. Plant growth promoting rhizobacterium

    Science.gov (United States)

    Doktycz, Mitchel John; Pelletier, Dale A.; Schadt, Christopher Warren; Tuskan, Gerald A.; Weston, David

    2015-08-11

    The present invention is directed to the Pseudomonas fluorescens strain GM30 deposited under ATCC Accession No. PTA-13340, compositions containing the GM30 strain, and methods of using the GM30 strain to enhance plant growth and/or enhance plant resistance to pathogens.

  19. Evolution & Diversity in Plants.

    Science.gov (United States)

    Pearson, Lorentz C.

    1988-01-01

    Summarizes recent findings that help in understanding how evolution has brought about the diversity of plant life that presently exists. Discusses basic concepts of evolution, diversity and classification, the three-line hypothesis of plant evolution, the origin of fungi, and the geologic time table. Included are 31 references. (CW)

  20. Methylome evolution in plants

    NARCIS (Netherlands)

    Vidalis, Amaryllis; Živković, Daniel; Wardenaar, René; Roquis, David; Tellier, Aurélien; Johannes, Frank

    2016-01-01

    Despite major progress in dissecting the molecular pathways that control DNA methylation patterns in plants, little is known about the mechanisms that shape plant methylomes over evolutionary time. Drawing on recent intra- and interspecific epigenomic studies, we show that methylome evolution over

  1. Plants without arbuscular mycorrhizae

    Science.gov (United States)

    P is second to N as the most limiting element for plant growth. Plants have evolved a number of effective strategies to acquire P and grow in a P-limited environment. Physiological, biochemical, and molecular studies of P-deficiency adaptations that occur in non-mycorrhizal species have provided str...

  2. Plant pathogen resistance

    Energy Technology Data Exchange (ETDEWEB)

    Greenberg, Jean T.; Jung, Ho Won; Tschaplinski, Timothy

    2015-10-20

    Azelaic acid or its derivatives or analogs induce a robust and a speedier defense response against pathogens in plants. Azelaic acid treatment alone does not induce many of the known defense-related genes but activates a plant's defense signaling upon pathogen exposure.

  3. Plant names and classification

    Science.gov (United States)

    This chapter updates one of the same title from Edition 12 of Stearn’s Introductory Biology published in 2011. It reviews binomial nomenclature, discusses three codes of plant nomenclature (the International Code of Botanical Nomenclature, the International Code of Nomenclature for Cultivated Plants...

  4. Better Plants Program Overview

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-09-30

    The U.S. Department of Energy’s (DOE’s) Better Buildings, Better Plants Program is a voluntary partnership initiative to drive significant energy efficiency improvement across energy intensive companies and organizations. 157 leading manufacturers and public water and wastewater treatment utilities are partnering with DOE through Better Plants to improve energy efficiency, slash carbon emissions, and cut energy costs.

  5. Power plant chemical technology

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-01

    17 contributions covering topies of fossil fuel combustion, flue gas cleaning, power plant materials, corrosion, water/steam cycle chemistry, monitoring and control were presented at the annual meeting devoted to Power Plant Chemical Technology 1996 at Kolding (Denmark) 4-6 September 1996. (EG)

  6. Plant growth promoting rhizobacterium

    Energy Technology Data Exchange (ETDEWEB)

    Doktycz, Mitchel John; Pelletier, Dale A.; Schadt, Christopher Warren; Tuskan, Gerald A.; Weston, David

    2015-08-11

    The present invention is directed to the Pseudomonas fluorescens strain GM30 deposited under ATCC Accession No. PTA-13340, compositions containing the GM30 strain, and methods of using the GM30 strain to enhance plant growth and/or enhance plant resistance to pathogens.

  7. Plant plastid engineering.

    Science.gov (United States)

    Wani, Shabir H; Haider, Nadia; Kumar, Hitesh; Singh, N B

    2010-11-01

    Genetic material in plants is distributed into nucleus, plastids and mitochondria. Plastid has a central role of carrying out photosynthesis in plant cells. Plastid transformation is becoming more popular and an alternative to nuclear gene transformation because of various advantages like high protein levels, the feasibility of expressing multiple proteins from polycistronic mRNAs, and gene containment through the lack of pollen transmission. Recently, much progress in plastid engineering has been made. In addition to model plant tobacco, many transplastomic crop plants have been generated which possess higher resistance to biotic and abiotic stresses and molecular pharming. In this mini review, we will discuss the features of the plastid DNA and advantages of plastid transformation. We will also present some examples of transplastomic plants developed so far through plastid engineering, and the various applications of plastid transformation.

  8. Automatic micropropagation of plants

    Science.gov (United States)

    Otte, Clemens; Schwanke, Joerg; Jensch, Peter F.

    1996-12-01

    Micropropagation is a sophisticated technique for the rapid multiplication of plants. It has a great commercial potential due to the speed of propagation, the high plant quality, and the ability to produce disease-free plants. However, micropropagation is usually done by hand which makes the process cost-intensive and tedious for the workers especially because it requires a sterile work-place. Therefore, we have developed a prototype automation system for the micropropagation of a grass species (miscanthus sinensis gigantheus). The objective of this paper is to describe the robotic system in an overview and to discuss the vision system more closely including the implemented morphological operations recognizing the cutting and gripping points of miscanthus plants. Fuzzy controllers are used to adapt the parameters of image operations on-line to each individual plant. Finally, we discuss our experiences with the developed prototype an give a preview of a possible real production line system.

  9. Exploiting plant alkaloids.

    Science.gov (United States)

    Schläger, Sabrina; Dräger, Birgit

    2016-02-01

    Alkaloid-containing plants have been used for medicine since ancient times. Modern pharmaceuticals still rely on alkaloid extraction from plants, some of which grow slowly, are difficult to cultivate and produce low alkaloid yields. Microbial cells as alternative alkaloid production systems are emerging. Before industrial application of genetically engineered bacteria and yeasts, several steps have to be taken. Original alkaloid-forming enzymes have to be elucidated from plants. Their activity in the heterologous host cells, however, may be low. The exchange of individual plant enzymes for alternative catalysts with better performance and optimal fermentation parameters appear promising. The overall aim is enhancement and stabilization of alkaloid yields from microbes in order to replace the tedious extraction of low alkaloid concentrations from intact plants.

  10. Cellulose metabolism in plants.

    Science.gov (United States)

    Hayashi, Takahisa; Yoshida, Kouki; Park, Yong Woo; Konishi, Teruko; Baba, Kei'ichi

    2005-01-01

    Many bacterial genomes contain a cellulose synthase operon together with a cellulase gene, indicating that cellulase is required for cellulose biosynthesis. In higher plants, there is evidence that cell growth is enhanced by the overexpression of cellulase and prevented by its suppression. Cellulase overexpression could modify cell walls not only by trimming off the paracrystalline sites of cellulose microfibrils, but also by releasing xyloglucan tethers between the microfibrils. Mutants for membrane-anchored cellulase (Korrigan) also show a typical phenotype of prevention of cellulose biosynthesis in tissues. All plant cellulases belong to family 9, which endohydrolyzes cellulose, but are not strong enough to cause the bulk degradation of cellulose microfibrils in a plant body. It is hypothesized that cellulase participates primarily in repairing or arranging cellulose microfibrils during cellulose biosynthesis in plants. A scheme for the roles of plant cellulose and cellulases is proposed.

  11. Terrestrial plant methane production

    DEFF Research Database (Denmark)

    Mikkelsen, Teis Nørgaard; Bruhn, Dan; Møller, Ian M.

    We evaluate all experimental work published on the phenomenon of aerobic methane (CH4) generation in terrestrial plants. We conclude that the phenomenon is true. Four stimulating factors have been observed to induce aerobic plant CH4 production, i.e. cutting injuries, increasing temperature......, ultraviolet radiation and reactive oxygen species. Further, we analyze rates of measured emission of aerobically produced CH4 in pectin and in plant tissues from different studies and argue that pectin is very far from the sole contributing precursor. Hence, scaling up of aerobic CH4 emission needs to take...... the aerobic methane emission in plants. Future work is needed for establishing the relative contribution of several proven potential CH4 precursors in plant material....

  12. Alvin plant story

    Energy Technology Data Exchange (ETDEWEB)

    Haas, H.J.; Jobe, H.J.; Rimel, S.F.; Hart, W.C.

    1968-11-11

    The Alvin plant, one of the world's largest high- ethane-recovery natural-gas-liquids-extraction plants, was designed to produce over 900,000 gal/day of natural gas liquids (NGL) and extract 50% of the contained ethane while processing 1,034 MMcfd of natural gas. The plant is a major component in a joint venture owned by Phillips Petroleum Co. and HNG Petrochemicals, Inc., a wholly owned subsidiary of Houston Natural Gas Corp. The joint venture also includes a products pipeline, an ethane storage cavern, and an ethylene manufacturing unit. Phillips engineering department designed the plant at the home offices in Bartlesville, Okla., and supervised its construction. Process-design features, mechanical-design features, and construction features are discussed. All products of the Alvin plant are used or marketed by Phillips for the benefit of the joint venture.

  13. Shaping plant architecture

    Directory of Open Access Journals (Sweden)

    Thomas eTeichmann

    2015-04-01

    Full Text Available Plants exhibit phenotypical plasticity. Their general body plan is genetically determined, but plant architecture and branching patterns are variable and can be adjusted to the prevailing environmental conditions. The modular design of the plant facilitates such morphological adaptations. The prerequisite for the formation of a branch is the initiation of an axillary meristem. Here, we review the current knowledge about this process. After its establishment, the meristem can develop into a bud which can either become dormant or grow out and form a branch. Many endogenous factors, such as photoassimilate availability, and exogenous factors like nutrient availability or shading, have to be integrated in the decision whether a branch is formed. The underlying regulatory network is complex and involves phytohormones and transcription factors. The hormone auxin is derived from the shoot apex and inhibits bud outgrowth indirectly in a process termed apical dominance. Strigolactones appear to modulate apical dominance by modification of auxin fluxes. Furthermore, the transcription factor BRANCHED1 plays a central role. The exact interplay of all these factors still remains obscure and there are alternative models. We discuss recent findings in the field along with the major models.Plant architecture is economically significant because it affects important traits of crop and ornamental plants, as well as trees cultivated in forestry or on short rotation coppices. As a consequence, plant architecture has been modified during plant domestication. Research revealed that only few key genes have been the target of selection during plant domestication and in breeding programs. Here, we discuss such findings on the basis of various examples. Architectural ideotypes that provide advantages for crop plant management and yield are described. We also outline the potential of breeding and biotechnological approaches to further modify and improve plant architecture

  14. Encapsulation plant at Forsmark

    Energy Technology Data Exchange (ETDEWEB)

    Nystroem, Anders

    2007-08-15

    SKB has already carried out a preliminary study of an encapsulation plant detached from Clab (Central interim storage for spent fuels). This stand-alone encapsulation plant was named FRINK and its assumed siting was the above-ground portion of the final repository, irrespective of the repository's location. The report previously presented was produced in cooperation with BNFL Engineering Ltd in Manchester and the fuel reception technical solution was examined by Gesellschaft fuer Nuklear-Service mbH (GNS) in Hannover and by Societe Generale pour les Techniques Nouvelles (SGN) in Paris. This report is an update of the earlier preliminary study report and is based on the assumption that the encapsulation plant and also the final repository will be sited in the Forsmark area. SKB's main alternative for siting the encapsulation plant is next to Clab. Planning of this facility is ongoing and technical solutions from the planning work have been incorporated in this report. An encapsulation plant placed in proximity to any final repository in Forsmark forms part of the alternative presentation in the application for permission to construct and operate an installation at Clab. The main technical difference between the planned encapsulation plant at Clab and an encapsulation plant at a final repository at Forsmark is how the fuel is managed and prepared before actual encapsulation. Fuel reception at the encapsulation plant in Forsmark would be dry, i.e. there would be no water-filled pools at the facility. Clab is used for verificatory fuel measurements, sorting and drying of the fuel before transport to Forsmark. This means that Clab will require a measure of rebuilding and supplementary equipment. In purely technical terms, the prospects for building an encapsulation plant sited at Forsmark are good. A description of the advantages and drawbacks of siting the encapsulation plant at Clab as opposed to any final repository at Forsmark is presented in a separate

  15. Plant Sex Determination.

    Science.gov (United States)

    Pannell, John R

    2017-03-06

    Sex determination is as important for the fitness of plants as it is for animals, but its mechanisms appear to vary much more among plants than among animals, and the expression of gender in plants differs in important respects from that in most animals. In this Minireview, I provide an overview of the broad variety of ways in which plants determine sex. I suggest that several important peculiarities of plant sex determination can be understood by recognising that: plants show an alternation of generations between sporophytic and gametophytic phases (either of which may take control of sex determination); plants are modular in structure and lack a germ line (allowing for a quantitative expression of gender that is not common in animals); and separate sexes in plants have ultimately evolved from hermaphroditic ancestors. Most theorising about sex determination in plants has focused on dioecious species, but we have much to learn from monecious or hermaphroditic species, where sex is determined at the level of modules, tissues or cells. Because of the fundamental modularity of plant development and potentially important evolutionary links between monoecy and dioecy, it may be useful to relax the distinction often made between 'developmental sex determination' (which underpins the development of male versus female flowers in monoecious species) and 'genetic sex determination' (which underpins the separation of males and females in dioecious species, often mediated by a genetic polymorphism and sex chromosomes). I also argue for relaxing the distinction between sex determination involving a genetic polymorphism and that involving responses to environmental or hormonal cues, because non-genetic cues might easily be converted into genetic switches.

  16. Mycoplasma infections of plants.

    Science.gov (United States)

    Bove, J M

    1981-07-01

    Plants can be infected by two types of wall-less procaryotes, spiroplasmas and mycoplasma-like organisms (MLO), both located intracellularly in the phloem tissues of affected plants. Spiroplasmas have been cultured, characterized and shown to be true members of the class Mollicutes. MLO have not yet been cultured or characterized; they are thought to be mycoplasma-like on the basis of their ultrastructure as seen in situ, their sensitivity to tetracycline and resistance to penicillin. Mycoplasmas can also be found on the surface of plants. These extracellularly located organisms are members of the following genera: Spiroplasma. Mycoplasma and Acholeplasma. The presence of such surface mycoplasmas must not be overlooked when attempts to culture MLO from affected plants are undertaken. Sensitive serological techniques such as the enzyme-linked immunosorbent assay (ELISA) can successfully be used to compare the MLO located in the phloem of affected plants with those eventually cultured from the same plants. In California and Morocco periwinkles naturally infected with both Spiroplasma citri and MLO have been reported. With such doubly infected plants, the symptom expression has been that characteristic of the MLO disease (phyllody or stolbur), not that given by S. citri. Only S. citri can be cultured from such plants, but this does not indicate that S. citri is the causal agent of the disease expressed by the plant. In California many nonrutaceous plants have been found to be infected with S. citri. Stubborn affected citrus trees represent an important reservoir of S. citri, and Circulifer tenellus is an active leafhopper vector of S. citri. Hence, it is not surprising that in California MLO-infected fruit trees could also become infected with S. citri but it would not mean that S. citri is the causal agent of the disease. Criteria are discussed that are helpful in distinguishing between MLO infections and S. citri infections.

  17. Plant nuclear envelope proteins.

    Science.gov (United States)

    Rose, Annkatrin; Patel, Shalaka; Meier, Iris

    2004-01-01

    Compared to research in the animal field, the plant NE has been clearly under-investigated. The available data so far indicate similarities as well as striking differences that raise interesting questions about the function and evolution of the NE in different kingdoms. Despite a seemingly similar structure and organization of the NE, many of the proteins that are integral components of the animal NE appear to lack homologues in plant cells. The sequencing of the Arabidopsis genome has not led to the identification of homologues of animal NE components, but has indicated that the plant NE must have a distinct protein composition different from that found in metazoan cells. Besides providing a selective barrier between the nucleoplasm and the cytoplasm, the plant NE functions as a scaffold for chromatin but the scaffolding components are not identical to those found in animal cells. The NE comprises an MTOC in higher plant cells, a striking difference to the organization of microtubule nucleation in other eukaryotic cells. Nuclear pores are present in the plant NE, but identifiable orthologues of most animal and yeast nucleoporins are presently lacking. The transport pathway through the nuclear pores via the action of karyopherins and the Ran cycle is conserved in plant cells. Interestingly, RanGAP is sequestered to the NE in plant cells and animal cells, yet the targeting domains and mechanisms of attachment are different between the two kingdoms. At present, only a few proteins localized at the plant NE have been identified molecularly. Future research will have to expand the list of known protein components involved in building a functional plant NE.

  18. Global Activities and Plant Survival

    DEFF Research Database (Denmark)

    Bandick, Roger

    2014-01-01

    This chapter provides an extensive review of the empirical evidence found for Sweden concerning plant survival. The result reveals that foreign MNE plants and exporting non-MNE plants have the lowest exit rates, followed by purely domestic-oriented plants, and that domestic MNE plants have...... the highest exit rates. Moreover, the exit rates of globally engaged plants seem to be unaffected by increased foreign presence, whereas there appears to be a negative impact on the survival rates of non-exporting non-MNE plants. Finally, the result reveals that the survival ratio of plants of acquired...... exporters, but not other types of plants, improves post acquisition....

  19. The Development of Plant Biotechnology.

    Science.gov (United States)

    Torrey, John G.

    1985-01-01

    Examines major lines of thought leading to what is meant by plant biotechnology, namely, the application of existing techniques of plant organ, tissue, and cell culture, plant molecular biology, and genetic engineering to the improvement of plants and of plant productivity for the benefit of man. (JN)

  20. Plant-soil feedbacks: role of plant functional group and plant traits

    NARCIS (Netherlands)

    Cortois, R.; Schröder-Georgi, T.; Weigelt, A.; van der Putten, W.H.; De Deyn, G.B.

    2016-01-01

    Plant-soil feedback (PSF), plant trait and functional group concepts advanced our understanding of plant community dynamics, but how they are interlinked is poorly known. To test how plant functional groups (FGs: graminoids, small herbs, tall herbs, legumes) and plant traits relate to PSF, we grew 4

  1. TOR signalling in plants.

    Science.gov (United States)

    Rexin, Daniel; Meyer, Christian; Robaglia, Christophe; Veit, Bruce

    2015-08-15

    Although the eukaryotic TOR (target of rapamycin) kinase signalling pathway has emerged as a key player for integrating nutrient-, energy- and stress-related cues with growth and metabolic outputs, relatively little is known of how this ancient regulatory mechanism has been adapted in higher plants. Drawing comparisons with the substantial knowledge base around TOR kinase signalling in fungal and animal systems, functional aspects of this pathway in plants are reviewed. Both conserved and divergent elements are discussed in relation to unique aspects associated with an autotrophic mode of nutrition and adaptive strategies for multicellular development exhibited by plants.

  2. Radiation hormesis in plant

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Sung; Song, Hi Sup; Lee, Young Keun; Lee, Byung Hun; Shin, In Chul; Lim, Young Taek

    2000-04-01

    This research was performed to investigate the effects of low dose {gamma}-ray radiation on the seed germination and the following physiological responses in vegetable crops. Special attention was focused on whether the resistance of vegetables against the unfavorable conditions of environment such as subsequent high doses of radiation or Phytophthora blight of pepper could be enhanced as an aspect of radiation hormesis. Analysis and characterization of antioxidant enzyme from plant culture cells and radiation tolerant of transformed plants from antioxidant (POD) were accomplished in the plant irradiated with different dose of {gamma}-ray. (author)

  3. FRIB Cryogenic Plant Status

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, Kelly D. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Ganni, Venkatarao [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Knudsen, Peter N. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Casagranda, Fabio [Michigan State Univ., East Lansing, MI (United States)

    2015-12-01

    After practical changes were approved to the initial conceptual design of the cryogenic system for MSU FRIB and an agreement was made with JLab in 2012 to lead the design effort of the cryogenic plant, many activities are in place leading toward a cool-down of the linacs prior to 2018. This is mostly due to using similar equipment used at CHLII for the 12 GeV upgrade at JLab and an aggressive schedule maintained by the MSU Conventional Facilities department. Reported here is an updated status of the cryogenic plant, including the equipment procurement status, plant layout, facility equipment and project schedule.

  4. Radiation hormesis in plant

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Sung; Song, Hi Sup; Lee, Young Keun; Cun, Ki Jung; Shin, In Chul; Lim, Young Taek

    1999-04-01

    This research was performed to investigate the effects of low dose {gamma}-ray radiation on the seed germination and the following physiological responses in vegetable crops. Special attention was focused on whether the resistance of vegetables against the unfavorable conditions of environment such as acid rain or soil types could be enhanced as an aspect of radiation hormesis. Analysis and characterization of antioxidant enzyme from plant culture cells and radiation tolerant of transformed plants from antioxidant enzyme (POD) were accomplished in the plant irradiated with difference dosage of {gamma}-ray.

  5. Optofluidics of plants

    Science.gov (United States)

    Psaltis, Demetri; Vasdekis, Andreas E.; Choi, Jae-Woo

    2016-05-01

    Optofluidics is a tool for synthesizing optical systems, making use of the interaction of light with fluids. In this paper we explore optofluidic mechanisms that have evolved in plants where sunlight and fluidic control combine to define most of the functionality of the plan. We hope that the presentation of how plants function, from an optofluidics point of view, will open a window for the optics community to the vast literature of plant physiology and provide inspiration for new ideas for the design of bio-mimetic optofluidic devices.

  6. Plant Genome Duplication Database.

    Science.gov (United States)

    Lee, Tae-Ho; Kim, Junah; Robertson, Jon S; Paterson, Andrew H

    2017-01-01

    Genome duplication, widespread in flowering plants, is a driving force in evolution. Genome alignments between/within genomes facilitate identification of homologous regions and individual genes to investigate evolutionary consequences of genome duplication. PGDD (the Plant Genome Duplication Database), a public web service database, provides intra- or interplant genome alignment information. At present, PGDD contains information for 47 plants whose genome sequences have been released. Here, we describe methods for identification and estimation of dates of genome duplication and speciation by functions of PGDD.The database is freely available at http://chibba.agtec.uga.edu/duplication/.

  7. Wetland plants: biology and ecology

    National Research Council Canada - National Science Library

    Cronk, Julie K; Fennessy, M. Siobhan

    2001-01-01

    Providing a detailed account of the biology and ecology of wetland plants as well as applications of wetland plant science, this book presents a synthesis of studies and reviews from biology, plant...

  8. Belowground microbes mitigate plant-plant competition.

    Science.gov (United States)

    Fonseca, Márcia Bacelar; Dias, Teresa; Carolino, Maria Manuela; França, Marcel Giovanni Costa; Cruz, Cristina

    2017-09-01

    Dimorphandra wilsonii, a Cerrado endemic Fabaceae tree, is threatened by land-use changes. The few remaining individuals occur in areas dominated by alien grasses like Urochloa decumbens. We tested the impact of nitrogen (N) availability and symbionts' presence on mitigating the effects of competition from U. decumbens. Dimorphandra wilsonii seedlings were 50-week pot-cultivated under limiting (3mM) or non-limiting (10mM) N, with or without U. decumbens, and inoculated or not with a N-fixer (Bradyrhizobium sp.) and an arbuscular mycorrhizal fungus (AMF - Glomus etunicatum), both forming symbioses in the field. Since D. wilsonii seedlings grew more and 'lost' fewer nutrients under the symbionts' presence, symbionts mitigated plant-plant competition. Under limiting N, inoculated D. wilsonii seedlings grew more (despite no nodulation), but N fixation was only suggested when inoculated D. wilsonii seedlings competed with U. decumbens. D. wilsonii(13)C, and substrate's carbon and respiration suggest that only the microbes performing key functions received plant carbon. Under non-limiting N, inoculated D. wilsonii seedlings became enriched in (13)C, substrate accumulated carbon and microbial respiration increased, suggesting a more generalist microbial community. Data suggest inoculating D. wilsonii seeds/seedlings with AMF and N-fixers as a conservation measure. However, long-term field-studies need to confirm these conclusions. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. 选煤厂常用溜槽设计综述%An overview on common chute design in coal preparation plant

    Institute of Scientific and Technical Information of China (English)

    陈然

    2016-01-01

    The paper points out the critical role of the chute in preparation plant coal design, explains the main factors calling for attention to in the chute design, including arrangement, cross section, angle, sealing, cushion, noise reduction, wear resistance and maintenance. Combining with the analysis on chute for conveyer, screen, crusher etc., points out that, the chute structure should meet the property demands of the feeding or material-receiving equipment. The paper also introduces three crushing-proof chutes, emphatically the dial wheel chute.%围绕溜槽在选煤厂设计中的关键作用,阐述了溜槽设计中需要注意的主要因素包括:布置、断面、倾角、密封、缓冲、降噪、耐磨、检修等,通过对输送设备、筛机、破碎机等入料溜槽的介绍,指出溜槽结构应满足给料或受料设备的性能要求,列举了三种防块煤破碎溜槽,重点介绍了拨轮防破碎溜槽。

  10. Numerical simulation of displacement response of floating ice sheet induced by a moving air cushion vehicle in uniform depth%航行气垫船激励均匀水深浮冰层位移响应的数值模拟

    Institute of Scientific and Technical Information of China (English)

    丁志勇; 李宇辰; 张志宏; 卢再华

    2016-01-01

    在均匀水深条件下,基于 ALE算法对匀速航行气垫船激励浮冰层的位移响应问题进行数值模拟。计算不同气垫船速度和河道岸壁宽度条件下的冰层位移响应,获得对应于冰层最大垂向位移变形情况下的气垫船临界速度。计算结果与理论解和试验结果符合良好,验证计算方法的有效性。计算结果表明:在临界速度时冰层下陷位移达到最大,而河道岸壁的存在将会使临界速度减小。%Based on the ALE algorithm in uniform depth, the displacement response of floating ice sheet caused by a moving air cushion vehicle (ACV) was numerically simulated, the critical speed of moving load with maximum verticaldis-placement deformation of ice sheet were solved, the influence of river width on the displacement response and critical speed were analyzed. A good agreement exists among the numerical results and theoretical solutions as well as experimentalres-ults. The research shows that maximum depression deformation of ice sheet will appear at critical speed, and the existence of river bank will decrease the value of critical speed.

  11. Plutonium Finishing Plant

    Data.gov (United States)

    Federal Laboratory Consortium — The Plutonium Finishing Plant, also known as PFP, represented the end of the line (the final procedure) associated with plutonium production at Hanford.PFP was also...

  12. Plant Stem Cells

    National Research Council Canada - National Science Library

    Greb, Thomas; Lohmann, Jan U

    2016-01-01

    .... While the promise of organ regeneration and the end of cancer have captured our imagination, it has gone almost unnoticed that plant stem cells represent the ultimate origin of much of the food we...

  13. Advanced stellarator power plants

    Energy Technology Data Exchange (ETDEWEB)

    Miller, R.L.

    1994-07-01

    The stellarator is a class of helical/toroidal magnetic fusion devices. Recent international progress in stellarator power plant conceptual design is reviewed and comparisons in the areas of physics, engineering, and economics are made with recent tokamak design studies.

  14. Advanced stellarator power plants

    Energy Technology Data Exchange (ETDEWEB)

    Miller, R.L.

    1994-07-01

    The stellarator is a class of helical/toroidal magnetic fusion devices. Recent international progress in stellarator power plant conceptual design is reviewed and comparisons in the areas of physics, engineering, and economics are made with recent tokamak design studies.

  15. Poison plants (image)

    Science.gov (United States)

    ... by poor circulation, even stress. An example of contact dermatitis is the reaction of a sensitive person's skin to poison ivy, oak or sumac. Contact with these plants, which contain a chemical called ...

  16. Plant Vascular Biology 2010

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Biao

    2014-11-17

    This grant supported the Second International Conference on Plant Vascular Biology (PVB 2010) held July 24-28, 2010 on the campus of Ohio State University, Columbus, Ohio. Biao Ding (Ohio State University; OSU) and David Hannapel (Iowa State University; ISU) served as co-chairs of this conference. Biao Ding served as the local organizer. PVB is defined broadly here to include studies on the biogenesis, structure and function of transport systems in plants, under conditions of normal plant growth and development as well as of plant interactions with pathogens. The transport systems cover broadly the xylem, phloem, plasmodesmata and vascular cell membranes. The PVB concept has emerged in recent years to emphasize the integrative nature of the transport systems and approaches to investigate them.

  17. Plant stem cell niches.

    Science.gov (United States)

    Aichinger, Ernst; Kornet, Noortje; Friedrich, Thomas; Laux, Thomas

    2012-01-01

    Multicellular organisms possess pluripotent stem cells to form new organs, replenish the daily loss of cells, or regenerate organs after injury. Stem cells are maintained in specific environments, the stem cell niches, that provide signals to block differentiation. In plants, stem cell niches are situated in the shoot, root, and vascular meristems-self-perpetuating units of organ formation. Plants' lifelong activity-which, as in the case of trees, can extend over more than a thousand years-requires that a robust regulatory network keep the balance between pluripotent stem cells and differentiating descendants. In this review, we focus on current models in plant stem cell research elaborated during the past two decades, mainly in the model plant Arabidopsis thaliana. We address the roles of mobile signals on transcriptional modules involved in balancing cell fates. In addition, we discuss shared features of and differences between the distinct stem cell niches of Arabidopsis.

  18. Lipid signaling in plants

    NARCIS (Netherlands)

    Munnik, T.

    2010-01-01

    This book highlights the current status of plant lipid signaling. Written by leading researchers in the field, the chapters include detailed information on the measurement, regulation and function of phospholipases, lipid kinases, lipid phosphatases, inositolpolyphosphates, polyphosphoinositides, ph

  19. Registration of Plant Varieties

    African Journals Online (AJOL)

    Ethiopia, forest soils that are either red or chocolate in color classified as Dystric. Nitisol with loam ... Ethiopia has significant benefit from export of ... Animal and Plant Health Inspection Directorate and are being maintained, multiplied, and ...

  20. Plant protein glycosylation

    Science.gov (United States)

    Strasser, Richard

    2016-01-01

    Protein glycosylation is an essential co- and post-translational modification of secretory and membrane proteins in all eukaryotes. The initial steps of N-glycosylation and N-glycan processing are highly conserved between plants, mammals and yeast. In contrast, late N-glycan maturation steps in the Golgi differ significantly in plants giving rise to complex N-glycans with β1,2-linked xylose, core α1,3-linked fucose and Lewis A-type structures. While the essential role of N-glycan modifications on distinct mammalian glycoproteins is already well documented, we have only begun to decipher the biological function of this ubiquitous protein modification in different plant species. In this review, I focus on the biosynthesis and function of different protein N-linked glycans in plants. Special emphasis is given on glycan-mediated quality control processes in the ER and on the biological role of characteristic complex N-glycan structures. PMID:26911286

  1. Nonferrous Metal Processing Plants

    Data.gov (United States)

    Department of Homeland Security — This map layer includes nonferrous metal processing plants in the United States. The data represent commodities covered by the Minerals Information Team (MIT) of the...

  2. Nuclear power plant maintainability.

    Science.gov (United States)

    Seminara, J L; Parsons, S O

    1982-09-01

    In the mid-1970s a general awareness of human factors engineering deficiencies associated with power plant control rooms took shape and the Electric Power Research Institute (EPRI) awarded the Lockheed Corporation a contract to review the human factors aspects of five representative operational control rooms and their associated simulators. This investigation revealed a host of major and minor deficiencies that assumed unforeseen dimensions in the post- Three Mile Island accident period. In the course of examining operational problems (Seminara et al, 1976) and subsequently the methods for overcoming such problems (Seminara et al, 1979, 1980) indications surfaced that power plants were far from ideal in meeting the needs of maintenance personnel. Accordingly, EPRI sponsored an investigation of the human factors aspects of power plant maintainability (Seminara, 1981). This paper provides an overview of the maintainability problems and issues encountered in the course of reviewing five nuclear power plants.

  3. Nuclear Power Plants (Rev.)

    Energy Technology Data Exchange (ETDEWEB)

    Lyerly, Ray L.; Mitchell III, Walter [Southern Nuclear Engineering, Inc.

    1973-01-01

    Projected energy requirements for the future suggest that we must employ atomic energy to generate electric power or face depletion of our fossil-fuel resources—coal, oil, and gas. In short, both conservation and economic considerations will require us to use nuclear energy to generate the electricity that supports our civilization. Until we reach the time when nuclear power plants are as common as fossil-fueled or hydroelectric plants, many people will wonder how the nuclear plants work, how much they cost, where they are located, and what kinds of reactors they use. The purpose of this booklet is to answer these questions. In doing so, it will consider only central station plants, which are those that provide electric power for established utility systems.

  4. Memristors in plants.

    Science.gov (United States)

    Volkov, Alexander G; Tucket, Clayton; Reedus, Jada; Volkova, Maya I; Markin, Vladislav S; Chua, Leon

    2014-01-01

    We investigated electrical circuitry of the Venus flytrap, Mimosa pudica and Aloe vera. The goal was to discover if these plants might have a new electrical component--a resistor with memory. This element was postulated recently and the researchers were looking for its presence in different systems. The analysis was based on cyclic current-voltage characteristic where the resistor with memory should manifest itself. We found that the electrostimulation of plants by bipolar sinusoidal or triangle periodic waves induces electrical responses in the Venus flytrap, Mimosa pudica and Aloe vera with fingerprints of memristors. Tetraethylammonium chloride, an inhibitor of voltage gated K(+) channels, transforms a memristor to a resistor in plant tissue. Our results demonstrate that a voltage gated K(+) channel in the excitable tissue of plants has properties of a memristor. This study can be a starting point for understanding mechanisms of memory, learning, circadian rhythms, and biological clocks.

  5. Ferrous Metal Processing Plants

    Data.gov (United States)

    Department of Homeland Security — This map layer includes ferrous metal processing plants in the United States. The data represent commodities covered by the Minerals Information Team (MIT) of the...

  6. Plant Mobile Small RNAs

    OpenAIRE

    Dunoyer, Patrice; Melnyk, Charles; Molnar, Attila; Slotkin, R Keith

    2013-01-01

    In plants, RNA silencing is a fundamental regulator of gene expression, heterochromatin formation, suppression of transposable elements, and defense against viruses. The sequence specificity of these processes relies on small noncoding RNA (sRNA) molecules. Although the spreading of RNA silencing across the plant has been recognized for nearly two decades, only recently have sRNAs been formally demonstrated as the mobile silencing signals. Here, we discuss the various types of mobile sRNA mol...

  7. Wet hydrate dissolution plant

    OpenAIRE

    Stanković Mirjana S.; Kovačević Branimir T.; Pezo Lato L.

    2003-01-01

    The IGPC Engineering Department designed basic projects for a wet hydrate dissolution plant, using technology developed in the IGPC laboratories. Several projects were completed: technological, machine, electrical, automation. On the basis of these projects, a production plant with capacity of 50,000 t/y was manufactured, at "Zeolite Mira", Mira (VE), Italy, in 1997, for increasing detergent zeolite production from 50,000 to 100,000 t/y. Several goals were realized by designing a wet hydrate ...

  8. Synthetic Plant Defense Elicitors

    Directory of Open Access Journals (Sweden)

    Yasemin eBektas

    2015-01-01

    Full Text Available To defend themselves against invading pathogens plants utilize a complex regulatory network that coordinates extensive transcriptional and metabolic reprogramming. Although many of the key players of this immunity-associated network are known, the details of its topology and dynamics are still poorly understood. As an alternative to forward and reverse genetic studies, chemical genetics-related approaches based on bioactive small molecules have gained substantial popularity in the analysis of biological pathways and networks. Use of such molecular probes can allow researchers to access biological space that was previously inaccessible to genetic analyses due to gene redundancy or lethality of mutations. Synthetic elicitors are small drug like molecules that induce plant defense responses, but are distinct from known natural elicitors of plant immunity. While the discovery of the some synthetic elicitors had already been reported in the 1970s, recent breakthroughs in combinatorial chemical synthesis now allow for inexpensive high-throughput screens for bioactive plant defense-inducing compounds. Along with powerful reverse genetics tools and resources available for model plants and crop systems, comprehensive collections of new synthetic elicitors will likely allow plant scientists to study the intricacies of plant defense signaling pathways and networks in an unparalleled fashion. As synthetic elicitors can protect crops from diseases, without the need to be directly toxic for pathogenic organisms, they may also serve as promising alternatives to conventional biocidal pesticides, which often are harmful for the environment, farmers and consumers. Here we are discussing various types of synthetic elicitors that have been used for studies on the plant immune system, their modes-of-action as well as their application in crop protection.

  9. Plant Transgenerational Epigenetics

    OpenAIRE

    Quadrana, Leandro; Colot, Vincent

    2016-01-01

    International audience; Transgenerational epigenetics is defined in opposition to developmental epi-genetics and implies an absence of resetting of epigenetic states between generations. Unlike mammals, plants appear to be particularly prone to this type of inheritance. In this review, we summarize our knowledge about trans-generational epigenetics in plants, which entails heritable changes in DNA methylation. We emphasize the role of transposable elements and other repeat sequences in the cr...

  10. Imprinting in plants

    Institute of Scientific and Technical Information of China (English)

    GUTIERREZ-MARCOS Jose

    2009-01-01

    Genomic imprinting leads to the differential expression of parental alleles after fertilization. Imprinting appears to have evolved independently in mammals and flowering plants to regulate the development of nutrient-transfer placental tissues. In addition, the regulation of imprinting in both mammals and flowering plants involves changes in DNA methylation and histone methylation, thus suggesting that the epigenetic signals that regulate imprinting have been co-opted in these distantly related species.

  11. Powder detergents production plant

    OpenAIRE

    Stanković Mirjana S.; Pezo Lato L.

    2003-01-01

    The IGPC Engineering Department designed basic projects for powder detergent production plant, using technology developed in the IGPC laboratories, in 1998. - 2000. Several projects were completed: technological, machine, electrical, automation. On the basis of these projects, a production plant with a capacity of 25,000 t/y was manufactured, at "Delta In", Zrenjanin, in 2000.This technology was an innovation, because new approach in mixing a powder materials was used, as well as introducing ...

  12. The names of plants

    National Research Council Canada - National Science Library

    Gledhill, D

    2008-01-01

    ... of Plant Names, this book is in two parts. The first part has been written as an account of the way in which the naming of plants has changed with time and why the changes were necessary. It has not been the writer's intention to dwell upon the more fascinating aspects of common names but rather to progress from these to the situation which exists to...

  13. Adjacent patterns between adenoid and eustachian cushion and its clinical relation with otitis media with effusion%腺样体与咽鼓管圆枕的毗邻关系及其与分泌性中耳炎的相关性

    Institute of Scientific and Technical Information of China (English)

    杨柳; 孙文锴; 蔡蕾; 田滢

    2015-01-01

    目的观察腺样体肥大儿童的腺样体与咽鼓管圆枕的毗邻关系,探讨其与分泌性中耳炎的相关性。方法144例腺样体肥大(或同时扁桃体肥大)70°鼻内镜下行等离子消融术患儿,术中观察并记录腺样体与咽鼓管圆枕的毗邻关系,并将其分为Ⅰ、Ⅱ、Ⅲ共3型;比较3组患儿分泌性中耳炎发病率、腺样体重度肥大(A/N比值是否大于0.7)的发生率并计算有无统计学差异。结果本组患儿分泌性中耳炎发病率23.6%;腺样体与咽鼓管圆枕的毗邻关系及合并分泌性中耳炎,Ⅰ型3例(9.1%,3/33)、Ⅱ型10例(16.9%,10/59)、Ⅲ型21例(40.4%,21/52),Ⅰ型与Ⅱ型分泌性中耳炎发生率无显著性差异(χ2=1.077,P=0.299),Ⅰ型与Ⅲ型有显著性差异(χ2=9.757,P=0.002),Ⅱ型与Ⅲ型有显著性差异(χ2 =7.542,P=0.006);Ⅰ型和Ⅱ型组腺样体A/N>0.7之和为34.9%,三型组A/N>0.7为82.2%,Ⅰ型及Ⅱ型腺样体重度肥大率之和与Ⅲ型有显著性差异(χ2=30.556,P=0.000)。结论腺样体与咽鼓管圆枕毗邻关系及腺样体的肥大程度与分泌性中耳炎有显著相关性。%OB J ECT I V E To explore the adjacentpatterns between adenoid and Eustachian cushion in hypertrophic adenoid children and to study its relationship with otitis media with effusion(OME). METHODS A retrospective analysis was conducted in 144 cases of pediatric adenoidal hypertrophy(or concurrenttonsil hypertrophy) admitted for adenoid ablation under the 700 nasal endoscope. Children were divided into 3 groups(TypeⅠ, Ⅱ and Ⅲ) according to adjacentpatterns between adenoid and Eustachian cushion.The incidence of OME, severe hypertrophy of adenoid(A/N>0.7) in differentgroup were analyzed. RESULTS There were 34 children (23.6%) with OME, 3 (9.1%) in type Ⅰ, 10(16.9%) in type Ⅱ and 21(40.4%) in type Ⅲ. No significantdifference was existed between the incidence of OME in type

  14. Tetraspanin genes in plants.

    Science.gov (United States)

    Wang, Feng; Vandepoele, Klaas; Van Lijsebettens, Mieke

    2012-07-01

    Tetraspanins represent a four-transmembrane protein superfamily with a conserved structure and amino acid residues that are present in mammals, insects, fungi and plants. Tetraspanins interact with each other or with other membrane proteins to form tetraspanin-enriched microdomains that play important roles in development, pathogenesis and immune responses via facilitating cell-cell adhesion and fusion, ligand binding and intracellular trafficking. Here, we emphasize evolutionary aspects within the plant kingdom based on genomic sequence information. A phylogenetic tree based on 155 tetraspanin genes of 11 plant species revealed ancient and fast evolving clades. Tetraspanins were only present in multicellular plants, were often duplicated in the plant genomes and predicted by the electronic Fluorescent Pictograph for gene expression analysis to be either functionally redundant or divergent. Tetraspanins contain a large extracellular loop with conserved cysteines that provide the binding sites for the interactions. The Arabidopsis thaliana TETRASPANIN1/TORNADO2/EKEKO has a function in leaf and root patterning and TETRASPANIN3 was identified in the plasmodesmatal proteome, suggesting a role in cell-cell communication during plant development.

  15. Silica in higher plants.

    Science.gov (United States)

    Sangster, A G; Hodson, M J

    1986-01-01

    Opaline silica deposits are formed by many vascular (higher) plants. The capacity of these plants for silica absorption varies considerably according to genotype and environment. Plant communities exchange silica between soil and vegetation, especially in warmer climates. Silica deposition in epidermal cell walls offers mechanical and protective advantages. Biogenic silica particles from plants are also implicated in the causation of cancer. Recent techniques are reviewed which may aid in the identification of plant pathways for soluble silica movement to deposition sites and in the determination of ionic environments. Botanical investigations have focused on silicification of cell walls in relation to plant development, using scanning and transmission electron microscopy combined with X-ray microanalysis. Silica deposition in macrohair walls of the lemma of canary grass (Phalaris) begins at inflorescence emergence and closely follows wall thickening. The structure of the deposited silica may be determined by specific organic polymers present at successive stages of wall development. Lowering of transpiration by enclosure of Phalaris inflorescences in plastic bags reduced silica deposition in macrohairs. Preliminary freeze-substitution studies have located silicon, as well as potassium and chloride, in the cell vacuole and wall deposition sites during initial silicification.

  16. Landscaping plant epigenetics.

    Science.gov (United States)

    McKeown, Peter C; Spillane, Charles

    2014-01-01

    The understanding of epigenetic mechanisms is necessary for assessing the potential impacts of epigenetics on plant growth, development and reproduction, and ultimately for the response of these factors to evolutionary pressures and crop breeding programs. This volume highlights the latest in laboratory and bioinformatic techniques used for the investigation of epigenetic phenomena in plants. Such techniques now allow genome-wide analyses of epigenetic regulation and help to advance our understanding of how epigenetic regulatory mechanisms affect cellular and genome function. To set the scene, we begin with a short background of how the field of epigenetics has evolved, with a particular focus on plant epigenetics. We consider what has historically been understood by the term "epigenetics" before turning to the advances in biochemistry, molecular biology, and genetics which have led to current-day definitions of the term. Following this, we pay attention to key discoveries in the field of epigenetics that have emerged from the study of unusual and enigmatic phenomena in plants. Many of these phenomena have involved cases of non-Mendelian inheritance and have often been dismissed as mere curiosities prior to the elucidation of their molecular mechanisms. In the penultimate section, consideration is given to how advances in molecular techniques are opening the doors to a more comprehensive understanding of epigenetic phenomena in plants. We conclude by assessing some opportunities, challenges, and techniques for epigenetic research in both model and non-model plants, in particular for advancing understanding of the regulation of genome function by epigenetic mechanisms.

  17. Molecular plant volatile communication.

    Science.gov (United States)

    Holopainen, Jarmo K; Blande, James D

    2012-01-01

    Plants produce a wide array of volatile organic compounds (VOCs) which have multiple functions as internal plant hormones (e.g., ethylene, methyl jasmonate and methyl salicylate), in communication with conspecific and heterospecific plants and in communication with organisms of second (herbivores and pollinators) and third (enemies of herbivores) trophic levels. Species specific VOCs normally repel polyphagous herbivores and those specialised on other plant species, but may attract specialist herbivores and their natural enemies, which use VOCs as host location cues. Attraction of predators and parasitoids by VOCs is considered an evolved indirect defence, whereby plants are able to indirectly reduce biotic stress caused by damaging herbivores. In this chapter we review these interactions where VOCs are known to play a crucial role. We then discuss the importance of volatile communication in self and nonself detection. VOCs are suggested to appear in soil ecosystems where distinction of own roots from neighbours roots is essential to optimise root growth, but limited evidence of above-ground plant self-recognition is available.

  18. Power plant siting

    Energy Technology Data Exchange (ETDEWEB)

    Winter, J.V.; Conner, D.A.

    1978-01-01

    Just to keep up with expected demand, the US will need over 500 new power generation units by 1985. Where these power plants will be located is the subject of heated debate among utility officials, government leaders, conservationists, concerned citizens and a multitude of special interest groups. This book offers a balanced review of all of the salient factors that must be taken into consideration in selecting power plant locations. To deal with this enormously complex subject, the authors (1) offer a general overview of the history and reasoning behind present legislation on the state and national levels; (2) describe the many different agencies that have jurisdiction in power plant location, from local water authorities and city councils to state conservation boards and the Nuclear Regulatory Commission; and (3) include a state-by-state breakdown of siting laws, regulations and present licensing procedures. Architects, engineers, contractors, and others involved in plant construction and site evaluation will learn of the trade-offs that must be made in balancing the engineering, economic, and environmental impacts of plant location. The book covers such areas as availability of water supplies for generation or cooling; geology, typography, and demography of the proposed site; and even the selection of the fuel best suited for the area. Finally, the authors examine the numerous environmental aspects of power plant siting.

  19. Plant toxicity, adaptive herbivory, and plant community dynamics

    Science.gov (United States)

    Zhilan Feng; Rongsong Liu; Donald L. DeAngelis; John P. Bryant; Knut Kielland; F. Stuart Chapin; Robert K. Swihart

    2009-01-01

    We model effects of interspecific plant competition, herbivory, and a plant's toxic defenses against herbivores on vegetation dynamics. The model predicts that, when a generalist herbivore feeds in the absence of plant toxins, adaptive foraging generally increases the probability of coexistence of plant species populations, because the herbivore switches more of...

  20. Chapter 15. Plant pathology and managing wildland plant disease systems

    Science.gov (United States)

    David L. Nelson

    2004-01-01

    Obtaining specific, reliable knowledge on plant diseases is essential in wildland shrub resource management. However, plant disease is one of the most neglected areas of wildland resources experimental research. This section is a discussion of plant pathology and how to use it in managing plant disease systems.

  1. Plant-mediated insect interactions on a perennial plant

    NARCIS (Netherlands)

    Stam, J.M.

    2016-01-01

    Plants interact with many organisms around them, and one of the most important groups that a plant has to deal with, are the herbivores. Insects represent the most diverse group of herbivores and have many different ways of using the plant as a food source. Plants can, however, defend themselves aga

  2. Promoting Interest in Plant Biology with Biographies of Plant Hunters.

    Science.gov (United States)

    Daisey, Peggy

    1996-01-01

    Describes the use of biographical stories to promote student interest in plant biology. Discusses plant hunters of various time periods, including ancient, middle ages, renaissance, colonial Americas, and 18th and 19th centuries; women plant hunters of the 1800s and early 1900s; and modern plant hunters. Discusses classroom strategies for the…

  3. Plant-mediated insect interactions on a perennial plant

    NARCIS (Netherlands)

    Stam, J.M.

    2016-01-01

    Plants interact with many organisms around them, and one of the most important groups that a plant has to deal with, are the herbivores. Insects represent the most diverse group of herbivores and have many different ways of using the plant as a food source. Plants can, however, defend themselves

  4. Electroanalysis of Plant Thiols

    Directory of Open Access Journals (Sweden)

    Rene Kizek

    2007-06-01

    Full Text Available Due to unique physico-chemical properties of –SH moiety thiols comprise widegroup of biologically important compounds. A review devoted to biological functions ofglutathione and phytochelatins with literature survey of methods used to analysis of thesecompounds and their interactions with cadmium(II ions and Murashige-Skoog medium ispresented. For these purposes electrochemical techniques are used. Moreover, we revealedthe effect of three different cadmium concentrations (0, 10 and 100 μM on cadmiumuptake and thiols content in maize plants during 192 hours long experiments usingdifferential pulse anodic stripping voltammetry to detect cadmium(II ions and highperformance liquid chromatography with electrochemical detection to determineglutathione. Cadmium concentration determined in tissues of the plants cultivated innutrient solution containing 10 μM Cd was very low up to 96 hours long exposition andthen the concentration of Cd markedly increased. On the contrary, the addition of 100 μMCd caused an immediate sharp increase in all maize plant parts to 96 hours Cd expositionbut subsequently the Cd concentration increased more slowly. A high performance liquidchromatography with electrochemical detection was used for glutathione determination intreated maize plants after 96 and 192 hours of treatment. The highest total content of glutathione per one plant was 6 μg (96 h, 10 μM Cd in comparison with non-treated plant (control where glutathione content was 1.5 μg. It can be concluded that electrochemical techniques have proved to be useful to analyse plant thiols.

  5. Plants in alpine environments

    Science.gov (United States)

    Germino, Matthew J.

    2014-01-01

    Alpine and subalpine plant species are of special interest in ecology and ecophysiology because they represent life at the climate limit and changes in their relative abundances can be a bellwether for climate-change impacts. Perennial life forms dominate alpine plant communities, and their form and function reflect various avoidance, tolerance, or resistance strategies to interactions of cold temperature, radiation, wind, and desiccation stresses that prevail in the short growing seasons common (but not ubiquitous) in alpine areas. Plant microclimate is typically uncoupled from the harsh climate of the alpine, often leading to substantially warmer plant temperatures than air temperatures recorded by weather stations. Low atmospheric pressure is the most pervasive, fundamental, and unifying factor for alpine environments, but the resulting decrease in partial pressure of CO2 does not significantly limit carbon gain by alpine plants. Factors such as tree islands and topographic features create strong heterogeneous mosaics of microclimate and snow cover that are reflected in plant community composition. Factors affecting tree establishment and growth and formation of treeline are key to understanding alpine ecology. Carbohydrate and other carbon storage, rapid development in a short growing season, and physiological function at low temperature are prevailing attributes of alpine plants. A major contemporary research theme asks whether chilling at alpine-treeline affects the ability of trees to assimilate the growth resources and particularly carbon needed for growth or whether the growth itself is limited by the alpine environment. Alpine areas tend to be among the best conserved, globally, yet they are increasingly showing response to a range of anthropogenic impacts, such as atmospheric deposition.

  6. African names for American plants

    NARCIS (Netherlands)

    Andel, van T.R.

    2015-01-01

    African slaves brought plant knowledge to the New World, sometimes applying it to related plants they found there and sometimes bringing Old World plants with them. By tracing the linguistic parallels between names for plants in African languages and in communities descended from African slaves, pie

  7. Plant ID. Agricultural Lesson Plans.

    Science.gov (United States)

    Southern Illinois Univ., Carbondale. Dept. of Agricultural Education and Mechanization.

    This lesson plan is intended for use in conducting classes on plant identification. Presented first are a series of questions and answers designed to convey general information about the scientific classification of plants. The following topics are among those discussed: main types of plants; categories of vascular plants; gymnosperms and…

  8. Aquatic Plants and their Control.

    Science.gov (United States)

    Michigan State Dept. of Natural Resources, Lansing.

    Aquatic plants can be divided into two types: algae and macrophytes. The goal of aquatic plant management is to maintain a proper balance of plants within a lake and still retain the lake's recreational and economic importance. Aquatic plant management programs have two phases: long-term management (nutrient control), and short-term management…

  9. Antidiabetic Plants of Iran

    Directory of Open Access Journals (Sweden)

    Ashrafeddin Goushegir

    2011-10-01

    Full Text Available To identify the antidiabetic plants of Iran, a systematic review of the published literature on the efficacy of Iranian medicinal plant for glucose control in patients with type 2 diabetes mellitus was conducted. We performed an electronic literature search of MEDLINE, Science Direct, Scopus, Proquest, Ebsco, Googlescholar, SID, Cochrane Library Database, from 1966 up to June 2010. The search terms were complementary and alternative medicine (CAM, diabetes mellitus, plant (herb, Iran, patient, glycemic control, clinical trial, RCT, natural or herbal medicine, hypoglycemic plants, and individual herb names from popular sources, or combination of these key words. Available Randomized Controlled Trials (RCT published in English or Persian language examined effects of an herb (limited to Iran on glycemic indexes in type 2 diabetic patients were included. Among all of the articles identified in the initial database search, 23 trials were RCT, examining herbs as potential therapy for type 2 diabetes mellitus. The key outcome for antidiabetic effect was changes in blood glucose or HbA1 c, as well as improves in insulin sensitivity or resistance. Available data suggest that several antidiabetic plants of Iran need further study. Among the RCT studies, the best evidence in glycemic control was found in Citrullus colocynthus, Ipomoea betatas, Silybum marianum and Trigonella foenum graecum.

  10. Plants, diet, and health.

    Science.gov (United States)

    Martin, Cathie; Zhang, Yang; Tonelli, Chiara; Petroni, Katia

    2013-01-01

    Chronic disease is a major social challenge of the twenty-first century. In this review, we examine the evidence for discordance between modern diets and those on which humankind evolved as the cause of the increasing incidence of chronic diseases, and the evidence supporting consumption of plant foods as a way to reduce the risk of chronic disease. We also examine the evidence for avoiding certain components of plant-based foods that are enriched in Western diets, and review the mechanisms by which different phytonutrients are thought to reduce the risk of chronic disease. This body of evidence strongly suggests that consuming more fruits and vegetables could contribute both to medical nutrition therapies, as part of a package of treatments for conditions like type 2 diabetes, heart disease, cancer, and obesity, and to the prevention of these diseases. Plant science should be directed toward improving the quality of plant-based foods by building on our improved understanding of the complex relationships between plants, our diet, and our health.

  11. GEOTHERMAL POWER GENERATION PLANT

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, Tonya

    2013-12-01

    Oregon Institute of Technology (OIT) drilled a deep geothermal well on campus (to 5,300 feet deep) which produced 196oF resource as part of the 2008 OIT Congressionally Directed Project. OIT will construct a geothermal power plant (estimated at 1.75 MWe gross output). The plant would provide 50 to 75 percent of the electricity demand on campus. Technical support for construction and operations will be provided by OIT’s Geo-Heat Center. The power plant will be housed adjacent to the existing heat exchange building on the south east corner of campus near the existing geothermal production wells used for heating campus. Cooling water will be supplied from the nearby cold water wells to a cooling tower or air cooling may be used, depending upon the type of plant selected. Using the flow obtained from the deep well, not only can energy be generated from the power plant, but the “waste” water will also be used to supplement space heating on campus. A pipeline will be construction from the well to the heat exchanger building, and then a discharge line will be construction around the east and north side of campus for anticipated use of the “waste” water by facilities in an adjacent sustainable energy park. An injection well will need to be drilled to handle the flow, as the campus existing injection wells are limited in capacity.

  12. Engineered plant virus resistance.

    Science.gov (United States)

    Galvez, Leny C; Banerjee, Joydeep; Pinar, Hasan; Mitra, Amitava

    2014-11-01

    Virus diseases are among the key limiting factors that cause significant yield loss and continuously threaten crop production. Resistant cultivars coupled with pesticide application are commonly used to circumvent these threats. One of the limitations of the reliance on resistant cultivars is the inevitable breakdown of resistance due to the multitude of variable virus populations. Similarly, chemical applications to control virus transmitting insect vectors are costly to the farmers, cause adverse health and environmental consequences, and often result in the emergence of resistant vector strains. Thus, exploiting strategies that provide durable and broad-spectrum resistance over diverse environments are of paramount importance. The development of plant gene transfer systems has allowed for the introgression of alien genes into plant genomes for novel disease control strategies, thus providing a mechanism for broadening the genetic resources available to plant breeders. Genetic engineering offers various options for introducing transgenic virus resistance into crop plants to provide a wide range of resistance to viral pathogens. This review examines the current strategies of developing virus resistant transgenic plants.

  13. Geothermal Power Generation Plant

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, Tonya [Oregon Inst. of Technology, Klamath Falls, OR (United States). Geo-Heat Center

    2013-12-01

    Oregon Institute of Technology (OIT) drilled a deep geothermal well on campus (to 5,300 feet deep) which produced 196°F resource as part of the 2008 OIT Congressionally Directed Project. OIT will construct a geothermal power plant (estimated at 1.75 MWe gross output). The plant would provide 50 to 75 percent of the electricity demand on campus. Technical support for construction and operations will be provided by OIT’s Geo-Heat Center. The power plant will be housed adjacent to the existing heat exchange building on the south east corner of campus near the existing geothermal production wells used for heating campus. Cooling water will be supplied from the nearby cold water wells to a cooling tower or air cooling may be used, depending upon the type of plant selected. Using the flow obtained from the deep well, not only can energy be generated from the power plant, but the “waste” water will also be used to supplement space heating on campus. A pipeline will be construction from the well to the heat exchanger building, and then a discharge line will be construction around the east and north side of campus for anticipated use of the “waste” water by facilities in an adjacent sustainable energy park. An injection well will need to be drilled to handle the flow, as the campus existing injection wells are limited in capacity.

  14. Micropropagation of some ornamental plants

    OpenAIRE

    Koleva Gudeva, Liljana; Spasenoski, Mirko

    2002-01-01

    Till now many horticulture plants have been successfully regenerated on in vitro conditions. Among them there are ornamental plants such as: Rosa-miniature pot roses; myrillocatus geometrizans-cacti, succulent plant; Echinopsis spachiana-cacti, succulent plant and Dianthus cariophyllus-carnation. Regeneration or micropropagation has been used for production of copies(clones) of the original unique plants(Hussery, 1986). Depending on the species, apical or axillar buds was used for micropro...

  15. Arsenite transport in plants.

    Science.gov (United States)

    Ali, Waqar; Isayenkov, Stanislav V; Zhao, Fang-Jie; Maathuis, Frans J M

    2009-07-01

    Arsenic is a metalloid which is toxic to living organisms. Natural occurrence of arsenic and human activities have led to widespread contamination in many areas of the world, exposing a large section of the human population to potential arsenic poisoning. Arsenic intake can occur through consumption of contaminated crops and it is therefore important to understand the mechanisms of transport, metabolism and tolerance that plants display in response to arsenic. Plants are mainly exposed to the inorganic forms of arsenic, arsenate and arsenite. Recently, significant progress has been made in the identification and characterisation of proteins responsible for movement of arsenite into and within plants. Aquaporins of the NIP (nodulin26-like intrinsic protein) subfamily were shown to transport arsenite in planta and in heterologous systems. In this review, we will evaluate the implications of these new findings and assess how this may help in developing safer and more tolerant crops.

  16. Willow plant name 'Preble'

    Science.gov (United States)

    Abrahamson, Lawrence P.; Kopp, Richard F.; Smart, Lawrence B.; Volk, Timothy A.

    2014-06-10

    A distinct female cultivar of Salix viminalis.times.(Salix sachalinensis.times.Salix miyabeana) named `Preble`, characterized by rapid stem growth producing 29% more woody biomass than the average of three current production cultivars (Salix.times.dasyclados `SV1` (unpatented), Salix sachalinensis `SX61` (unpatented), and Salix miyabeana `SX64` (unpatented)) when grown in the same field for the same length of time (three growing seasons after coppice) in two different trials in Constableville, N.Y. and Middlebury, Vt. `Preble` can be planted from dormant stem cuttings, produces multiple stems after coppice and the stem biomass can be harvested when the plant is dormant. In the spring following harvest, the plant will re-sprout very vigorously, producing new stems that can be harvested repeatedly after two to four years of growth. `Preble` displays a low incidence of rust disease and is not damaged by potato leafhoppers.

  17. PV power plants

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    Within the international seminar of the Ostbayerisches Technologie-Transfer-Institut e.V. (OTTI) at 11th June, 2012 in Munich (Federal Republic of Germany), the following lectures were held: (1) Technical due diligence (Dietmar Obst); (2) Certification / rating system for large PV plants (Robert Pfatischer); (3) O and M requirements (Lars Rulf); (4) IR photography for large scale systems (Bernhard Weinreich); (5) New market models for PV systems - direct marketing and sales of PV electricity (Martin Schneider); (6) Needs and benefits for plant certification for grid connection and operation (Christoph Luetke-Lengerich); (7) Lare volume module testing / Screening in the field and workshop (Semir Merzoug); (8) Dismantling costs of large scale PV plants (Siegfried Schimpf).

  18. Domestication and plant genomes.

    Science.gov (United States)

    Tang, Haibao; Sezen, Uzay; Paterson, Andrew H

    2010-04-01

    The techniques of plant improvement have been evolving with the advancement of technology, progressing from crop domestication by Neolithic humans to scientific plant breeding, and now including DNA-based genotyping and genetic engineering. Archeological findings have shown that early human ancestors often unintentionally selected for and finally fixed a few major domestication traits over time. Recent advancement of molecular and genomic tools has enabled scientists to pinpoint changes to specific chromosomal regions and genetic loci that are responsible for dramatic morphological and other transitions that distinguish crops from their wild progenitors. Extensive studies in a multitude of additional crop species, facilitated by rapid progress in sequencing and resequencing(s) of crop genomes, will further our understanding of the genomic impact from both the unusual population history of cultivated plants and millennia of human selection.

  19. Annotation on Mangrove Plants

    Institute of Scientific and Technical Information of China (English)

    王伯荪; 张炜银; 梁士楚; 昝启杰

    2004-01-01

    This paper reviews and discusses the technical terms and definition of mangrove and mangal, as well as mangrove plant. The word mangrove has been used to refer either to the constituent plant of tropical and subtropical intertidal community or to the community itself, but this usage makes more confusion. Being leaved mangrove in the more limited sense for the constituent plant species, mangal was proposed by MacNae (1968) as aterm for mangrove community, which has been universally applied to most previous studies and should be adopted now. Mangrove should be therefore defined as a tropical and subtropical tree restricted to intertidal zones, which possesses some morphological specializion and physiological mechanism adapted to its habitat, and mangal as a tropical and subtropical forest community restricted to marine intertidal zones and periodically inundeated by the tides. A new term ″consortive plant″ is proposed here for herb, liana, epiphyte or parasite, which is restricted in the strict mangrove habitat.

  20. Geothermal Plant Capacity Factors

    Energy Technology Data Exchange (ETDEWEB)

    Greg Mines; Jay Nathwani; Christopher Richard; Hillary Hanson; Rachel Wood

    2015-01-01

    The capacity factors recently provided by the Energy Information Administration (EIA) indicated this plant performance metric had declined for geothermal power plants since 2008. Though capacity factor is a term commonly used by geothermal stakeholders to express the ability of a plant to produce power, it is a term frequently misunderstood and in some instances incorrectly used. In this paper we discuss how this capacity factor is defined and utilized by the EIA, including discussion on the information that the EIA requests from operations in their 923 and 860 forms that are submitted both monthly and annually by geothermal operators. A discussion is also provided regarding the entities utilizing the information in the EIA reports, and how those entities can misinterpret the data being supplied by the operators. The intent of the paper is to inform the facility operators as the importance of the accuracy of the data that they provide, and the implications of not providing the correct information.

  1. Plant redox proteomics

    DEFF Research Database (Denmark)

    Navrot, Nicolas; Finnie, Christine; Svensson, Birte

    2011-01-01

    In common with other aerobic organisms, plants are exposed to reactive oxygen species resulting in formation of post-translational modifications related to protein oxidoreduction (redox PTMs) that may inflict oxidative protein damage. Accumulating evidence also underscores the importance of redox...... PTMs in regulating enzymatic activities and controlling biological processes in plants. Notably, proteins controlling the cellular redox state, e.g. thioredoxin and glutaredoxin, appear to play dual roles to maintain oxidative stress resistance and regulate signal transduction pathways via redox PTMs....... To get a comprehensive overview of these types of redox-regulated pathways there is therefore an emerging interest to monitor changes in redox PTMs on a proteome scale. Compared to some other PTMs, e.g. protein phosphorylation, redox PTMs have received less attention in plant proteome analysis, possibly...

  2. Tungsten Toxicity in Plants

    Science.gov (United States)

    Adamakis, Ioannis-Dimosthenis S.; Panteris, Emmanuel; Eleftheriou, Eleftherios P.

    2012-01-01

    Tungsten (W) is a rare heavy metal, widely used in a range of industrial, military and household applications due to its unique physical properties. These activities inevitably have accounted for local W accumulation at high concentrations, raising concerns about its effects for living organisms. In plants, W has primarily been used as an inhibitor of the molybdoenzymes, since it antagonizes molybdenum (Mo) for the Mo-cofactor (MoCo) of these enzymes. However, recent advances indicate that, beyond Mo-enzyme inhibition, W has toxic attributes similar with those of other heavy metals. These include hindering of seedling growth, reduction of root and shoot biomass, ultrastructural malformations of cell components, aberration of cell cycle, disruption of the cytoskeleton and deregulation of gene expression related with programmed cell death (PCD). In this article, the recent available information on W toxicity in plants and plant cells is reviewed, and the knowledge gaps and the most pertinent research directions are outlined. PMID:27137642

  3. Plant adenylate cyclases.

    Science.gov (United States)

    Lomovatskaya, Lidiya A; Romanenko, Anatoliy S; Filinova, Nadejda V

    2008-01-01

    Adenylate cyclase (AC) (ATP diphosphate-lyase cyclizing; EC 4.6.1.1) is a key component of the adenylate cyclase signaling system and catalyzes the generation of cyclic adenosine monophosphate (cAMP) from ATP. This review summarizes data from the literature and the authors' laboratory on the investigation of plant transmembrane (tmAC) and soluble (sAC) adenylate cyclases, in comparison with some key characteristics of adenylate cyclases of animal cells. Plant sAC has been demonstrated to exhibit similarities with animal sAC with respect to certain characteristics. External factors, such as far-red and red light, temperature, exogenous phytohormones, as well as specific triggering compounds of fungal and bacterial origin exert a significant influence on the activity of plant tmAC and sAC.

  4. Engineering of plant chromosomes.

    Science.gov (United States)

    Mette, Michael Florian; Houben, Andreas

    2015-02-01

    Engineered minimal chromosomes with sufficient mitotic and meiotic stability have an enormous potential as vectors for stacking multiple genes required for complex traits in plant biotechnology. Proof of principle for essential steps in chromosome engineering such as truncation of chromosomes by T-DNA-mediated telomere seeding and de novo formation of centromeres by cenH3 fusion protein tethering has been recently obtained. In order to generate robust protocols for application in plant biotechnology, these steps need to be combined and supplemented with additional methods such as site-specific recombination for the directed transfer of multiple genes of interest on the minichromosomes. At the same time, the development of these methods allows new insight into basic aspects of plant chromosome functions such as how centromeres assure proper distribution of chromosomes to daughter cells or how telomeres serve to cap the chromosome ends to prevent shortening of ends over DNA replication cycles and chromosome end fusion.

  5. Integrated Gasification SOFC Plant with a Steam Plant

    DEFF Research Database (Denmark)

    Rokni, Masoud; Pierobon, Leonardo

    2011-01-01

    enter into a burner to burn the rest of the fuel. The offgases after the burner are now used to generate steam in a Heat Recovery Steam Generator (HRSG). The generated steam is expanded in a ST to produce additional power. Thus a triple hybrid plant based on a gasification plant, a SOFC plant......A hybrid Solid Oxide Fuel Cell (SOFC) and Steam Turbine (ST) plant is integrated with a gasification plant. Wood chips are fed to the gasification plant to produce biogas and then this gas is fed into the anode side of a SOFC cycle to produce electricity and heat. The gases from the SOFC stacks...... and a steam plant is presented and studied. The plant is called as IGSS (Integrated Gasification SOFC Steam plant). Different systems layouts are presented and investigated. Electrical efficiencies up to 56% are achieved which is considerably higher than the conventional integrated gasification combined...

  6. Apoplastic interactions between plants and plant root intruders

    Directory of Open Access Journals (Sweden)

    Kanako eMitsumasu

    2015-08-01

    Full Text Available Numerous pathogenic or parasitic organisms attack plant roots to obtain nutrients, and the apoplast including the plant cell wall is where the plant cell meets such organisms. Root-parasitic angiosperms and nematodes are two distinct types of plant root parasites but share some common features in their strategies for breaking into plant roots. Striga and Orobanche are obligate root parasitic angiosperms that cause devastating agricultural problems worldwide. Parasitic plants form an invasion organ called a haustorium, where plant cell wall degrading enzymes (PCWDEs are highly expressed. Plant-parasitic nematodes are another type of agriculturally important plant root parasite. These nematodes breach the plant cell walls by protruding a sclerotized stylet from which PCWDEs are secreted. Responding to such parasitic invasion, host plants activate their own defense responses against parasites. Endoparasitic nematodes secrete apoplastic effectors to modulate host immune responses and to facilitate the formation of a feeding site. Apoplastic communication between hosts and parasitic plants also contributes to their interaction. Parasitic plant germination stimulants, strigolactones (SLs, are recently identified apoplastic signals that are transmitted over long distances from biosynthetic sites to functioning sites. Here, we discuss recent advances in understanding the importance of apoplastic signals and cell walls for plant-parasite interactions.

  7. Apoplastic interactions between plants and plant root intruders.

    Science.gov (United States)

    Mitsumasu, Kanako; Seto, Yoshiya; Yoshida, Satoko

    2015-01-01

    Numerous pathogenic or parasitic organisms attack plant roots to obtain nutrients, and the apoplast including the plant cell wall is where the plant cell meets such organisms. Root parasitic angiosperms and nematodes are two distinct types of plant root parasites but share some common features in their strategies for breaking into plant roots. Striga and Orobanche are obligate root parasitic angiosperms that cause devastating agricultural problems worldwide. Parasitic plants form an invasion organ called a haustorium, where plant cell wall degrading enzymes (PCWDEs) are highly expressed. Plant-parasitic nematodes are another type of agriculturally important plant root parasite. These nematodes breach the plant cell walls by protruding a sclerotized stylet from which PCWDEs are secreted. Responding to such parasitic invasion, host plants activate their own defense responses against parasites. Endoparasitic nematodes secrete apoplastic effectors to modulate host immune responses and to facilitate the formation of a feeding site. Apoplastic communication between hosts and parasitic plants also contributes to their interaction. Parasitic plant germination stimulants, strigolactones, are recently identified apoplastic signals that are transmitted over long distances from biosynthetic sites to functioning sites. Here, we discuss recent advances in understanding the importance of apoplastic signals and cell walls for plant-parasite interactions.

  8. Quantitative plant ecology

    DEFF Research Database (Denmark)

    Damgaard, Christian

    2014-01-01

    This e-book is written in the Wolfram' CDF format (download free CDF player from Wolfram.com) The objective of this e-book is to introduce the population ecological concepts for measuring and predicting the ecological success of plant species. This will be done by focusing on the measurement...... and statistical modelling of plant species abundance and the relevant ecological processes that control species abundance. The focus on statistical modelling and likelihood function based methods also means that more algorithm based methods, e.g. ordination techniques and boosted regression tress...

  9. Conceptualizing Pharmaceutical Plants

    DEFF Research Database (Denmark)

    Larsen, Bent Dalgaard; Jensen, Klaes Ladeby; Gjøl, Mikkel

    2006-01-01

    In the conceptual design phase of pharmaceutical plants as much as 80%-90% of the total cost of a project is committed. It is therefore essential that the chosen concept is viable. In this design process configuration and 3D models can help validate the decisions made. Designing 3D models...... is a complex task and requires skilled users. We demonstrate that a simple 2D/3D configuration tool can support conceptualizing of pharmaceutical plants. Present paper reports on preliminary results from a full scale implementation project at a Danish engineering company....

  10. Plant Mobile Small RNAs

    Science.gov (United States)

    Dunoyer, Patrice; Melnyk, Charles; Molnar, Attila; Slotkin, R. Keith

    2013-01-01

    In plants, RNA silencing is a fundamental regulator of gene expression, heterochromatin formation, suppression of transposable elements, and defense against viruses. The sequence specificity of these processes relies on small noncoding RNA (sRNA) molecules. Although the spreading of RNA silencing across the plant has been recognized for nearly two decades, only recently have sRNAs been formally demonstrated as the mobile silencing signals. Here, we discuss the various types of mobile sRNA molecules, their short- and long-range movement, and their function in recipient cells. PMID:23818501

  11. Total Logistic Plant Solutions

    Directory of Open Access Journals (Sweden)

    Dusan Dorcak

    2016-02-01

    Full Text Available The Total Logistics Plant Solutions, plant logistics system - TLPS, based on the philosophy of advanced control processes enables complex coordination of business processes and flows and the management and scheduling of production in the appropriate production plans and planning periods. Main attributes of TLPS is to create a comprehensive, multi-level, enterprise logistics information system, with a certain degree of intelligence, which accepts the latest science and research results in the field of production technology and logistics. Logistic model of company understands as a system of mutually transforming flows of materials, energy, information, finance, which is realized by chain activities and operations

  12. Multiplex tokamak power plant

    Energy Technology Data Exchange (ETDEWEB)

    Dabiri, A.E.

    1986-07-01

    The concept of multiplexing for a fusion power core as an option for producing power is explored. Superconducting, as well as normal magnet, coils in either first or second stability regimes are considered. The results show that multiplex plants with superconducting magnets operating in the second stability regime could be competitive with the single-unit plants in some unit sizes. The key issues that impact the expected benefits of multiplexing must be investigated further. These are factory fabrication, economy of scale, the extent of equipment sharing, inherent safety, maintainability, and utility load management.

  13. The plant exocyst

    NARCIS (Netherlands)

    Zhang, Y.; Emons, A.M.C.; Ketelaar, T.

    2010-01-01

    exocyst is an octameric vesicle tethering complex that functions upstream of SNARE mediated exocytotic vesicle fusion with the plasma membrane. All proteins in the complex have been conserved during evolution, and genes that encode the exocyst subunits are present in the genomes of all plants invest

  14. Radiosensitivity in plants

    Energy Technology Data Exchange (ETDEWEB)

    Nauman, A F

    1979-01-01

    The report presents a compilation of available data on the sensitivity of plants to ionizing radiation, and provides basic information on methods of determining such sensitivities, or of estimating radiosensitivities by calcuation of the nuclear factors upon which they depend. The scope of the data presented here is necessarily limited to the most generally useful radiobiological end points and to the most commonly-used types of radiation. Many of the factors which influence radiosensitivity, particularly nuclear factors, will be discussed. Emphasis will be upon whole-plant studies done at Brookhaven National Laboratory by A.H. Sparrow and his associates, since these studies are the source of most of the available radiosensitivity data and of all the sensitivity predictions listed here. Data presented here include summaries of experimentally-determined radiosensitivities at various end points for both herbaceous and woody higher plants, and for a few species of ferns and lower plants. The algae and fungi have not been considered here due to space limitations.

  15. Plants flex their skeletons

    DEFF Research Database (Denmark)

    Foster, Randy; Mattsson, Ole; Mundy, John

    2003-01-01

    Recent work on the fragile fiber mutants of Arabidopsis has identified microtubule-associated proteins that affect the orientation of cellulose microfibrils in cell walls, a major determinant of plant elongation growth. These same proteins are implicated in responses to gibberellin, provoking fresh...

  16. Chromatin dynamics in plants

    NARCIS (Netherlands)

    Fransz, P.F.; Jong, de J.H.

    2002-01-01

    Recent studies in yeast, animals and plants have provided major breakthroughs in unraveling the molecular mechanism of higher-order gene regulation. In conjunction with the DNA code, proteins that are involved in chromatin remodeling, histone modification and epigenetic imprinting form a large

  17. Plants on the Move

    Science.gov (United States)

    Bricker, Mary

    2009-01-01

    When it comes to directly interacting with and doing experiments with organisms, plants have some distinct advantages over animals. Their diversity and accessibility allows students to use them in experiments, thus practicing important science inquiry skills. This article describes an investigation that was designed to help students appreciate the…

  18. Plants, People, and Politics

    Science.gov (United States)

    Galston, Arthur W.

    1970-01-01

    Advocates that some established botanists should become involved in social and political problems to which botanical expertise is relevant. Discusses food production in relation to world population growth, indicating problems on which botanical knowledge and research should be brought to bear. Discusses herbicides and plant growth regulators as…

  19. Plant research '76

    Energy Technology Data Exchange (ETDEWEB)

    1976-01-01

    Overall objective remains unchanged: to contribute to the knowledge, with strong emphasis on fundamental problems, of how plants function, the roles they play in the environment and energy relations of the world, and how these roles may be optimized for the benefit of mankind. (PCS)

  20. Plant biochemistry course, 1993

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-12-31

    This paper provides a brief description of a summer lecture course on metabolic pathways and regulation of flow through these pathways in plants. Descriptions of the 1992 course held at La Jolla,Ca; 1993 course held in Madison, Wis, and plans for the 1994 course projected for East Lansing, MI.

  1. Chromatin dynamics in plants

    NARCIS (Netherlands)

    Fransz, P.F.; Jong, de J.H.

    2002-01-01

    Recent studies in yeast, animals and plants have provided major breakthroughs in unraveling the molecular mechanism of higher-order gene regulation. In conjunction with the DNA code, proteins that are involved in chromatin remodeling, histone modification and epigenetic imprinting form a large netwo

  2. Next Generation Plant Breeding

    NARCIS (Netherlands)

    Goud, J.C.

    2012-01-01

    Van 11-14 november 2012 vond in de Reehorst de conferentie ‘Next Generation Plant Breeding’ plaats. Tijdens deze bijeenkomst kwamen de grote uitdagingen van de toekomstige plantenveredeling aan de orde: de opkomst van nieuwe sequencing-technieken, de bijbehorende enorme hoeveelheid gegevens die gepr

  3. Nuclear Power Plant Technician

    Science.gov (United States)

    Randall, George A.

    1975-01-01

    The author recognizes a body of basic knowledge in nuclear power plant technoogy that can be taught in school programs, and lists the various courses, aiming to fill the anticipated need for nuclear-trained manpower--persons holding an associate degree in engineering technology. (Author/BP)

  4. Next Generation Plant Breeding

    NARCIS (Netherlands)

    Goud, J.C.

    2012-01-01

    Van 11-14 november 2012 vond in de Reehorst de conferentie ‘Next Generation Plant Breeding’ plaats. Tijdens deze bijeenkomst kwamen de grote uitdagingen van de toekomstige plantenveredeling aan de orde: de opkomst van nieuwe sequencing-technieken, de bijbehorende enorme hoeveelheid gegevens die

  5. [Amebicidal plants extracts].

    Science.gov (United States)

    Derda, Monika; Hadaś, Edward; Thiem, Barbara; Sułek, Anna

    2004-01-01

    The free-living amoebae from genus Acanthamoeba are the causative agents of granulomatous amebic encephalitis (GAE), a chronic progressive disease of the central nervous system; amebic keratitis (AK), a chronic eye infection; amebic pneumitis (AP), a chronic lung infection, and skin infection. Chemotherapy of Acanthamoeba infection is problematic. The majority of infections have been fatal. Only a few cases are reported to have been treated successfully with very highly toxic drugs. The therapy might be succeed, if the diagnosis and therapy is made at very early stage of infection. In our experiments we used the following plant extracts: Solidago virgaurea, Solidago graminifolia, Rubus chamaemorus, Pueraria lobata, and natural plants products as ellagic acid and puerarin. Those therapeutic agents and plants extracts have been tested in vitro for amebicidal or amebostatic activity against pathogenic Acanthamoeba spp. Our results showed that methanol extracts obtained from plants are active against axenic pathogenic Acanthamoeba sp. trophozoites in vitro at concentration below 0.1 mg/ml. Further studies are needed to investigate whether these extracts are also effective in vivo in animal model of infection with Acanthamoeba sp.

  6. Plants and Medicinal Chemistry

    Science.gov (United States)

    Bailey, D.

    1977-01-01

    This is the first of two articles showing how plants that have been used in folk medicine for many centuries are guiding scientists in the design and preparation of new and potent drugs. Opium and its chemical derivatives are examined at length in this article. (Author/MA)

  7. Salinity and Plants.

    Science.gov (United States)

    Langsford, Simon; Meredith, Steve; Munday, Bruce

    2002-01-01

    Presents science activities that mirror real life issues relating to plants and sustainability. Describes how to turn seed growing activities into an environmental simulation. Discusses the advantages of cross-curriculum learning opportunities. Includes student references and notes for teachers. (KHR)

  8. Peru, People and Plants.

    Science.gov (United States)

    Thompson, Dennis

    Designed for horticulture, horticulture therapy, and botany students at Edmonds Community College (Washington), this 6-hour module explores the pre-Columbian use of plant materials in Peru and its relationships to cultural practices in modern Peru. The first sections provide basic information about the module, such as its objectives, the concepts…

  9. Quantitative plant ecology

    DEFF Research Database (Denmark)

    Damgaard, Christian

    2014-01-01

    This e-book is written in the Wolfram' CDF format (download free CDF player from Wolfram.com) The objective of this e-book is to introduce the population ecological concepts for measuring and predicting the ecological success of plant species. This will be done by focusing on the measurement......, will not be covered in this e-book....

  10. Plant Protection Research Institute

    Directory of Open Access Journals (Sweden)

    N. Allsopp

    1993-12-01

    Full Text Available A survey of the mycorrhizal status of plants growing in the Cape Floristic Region of South Africa was undertaken to assess the range of mycorrhizal types and their dominance in species characteristic of this region. Records were obtained by ex­amining the root systems of plants growing in three Cape lowland vegetation types, viz. West Coast Strandveld, West Coast Renosterveld and Sand Plain Lowland Fynbos for mycorrhizas, as well as by collating literature records of mycorrhizas on plants growing in the region. The mycorrhizal status of 332 species is listed, of which 251 species are new records. Members of all the important families in this region have been examined. Mycorrhizal status appears to be associated mainly with taxonomic position of the species. Extrapolating from these results, we conclude that 62% of the flora of the Cape Floristic Region form vesicular-arbuscular mycorrhizas, 23% have no mycorrhizas, 8% are ericoid mycorrhizal, 2% form orchid mycorrhizas, whereas the mycorrhizal status of 4% of the flora is unknown. There were no indigenous ectomycor- rhizal species. The proportion of non-mycorrhizal species is high compared to other ecosystems. In particular, the lack of mycorrhizas in several important perennial families in the Cape Floristic Region is unusual. The diversity of nutrient acquir­ing adaptations, including the range of mycorrhizas and cluster roots in some non-mycorrhizal families, may promote co­existence of plants in this species-rich region.

  11. Plant Tissue Culture Studies.

    Science.gov (United States)

    Smith, Robert Alan

    Plant tissue culture has developed into a valid botanical discipline and is considered a key area of biotechnology, but it has not been a key component of the science curriculum because of the expensive and technical nature of research in this area. This manual presents a number of activities that are relatively easy to prepare and perform. The…

  12. Plant Biotech Lab Manual.

    Science.gov (United States)

    Tant, Carl

    This book provides laboratory experiments to enhance any food science/botany curriculum. Chapter 1, "Introduction," presents a survey of the techniques used in plant biotechnology laboratory procedures. Chapter 2, "Micronutrition," discusses media and nutritional requirements for tissue culture studies. Chapter 3, "Sterile Seeds," focuses on the…

  13. Plants under continuous light

    NARCIS (Netherlands)

    Velez Ramirez, A.I.; Ieperen, van W.; Vreugdenhill, D.; Millenaar, F.F.

    2011-01-01

    Continuous light is an essential tool for understanding the plant circadian clock. Additionally, continuous light might increase greenhouse food production. However, using continuous light in research and practice has its challenges. For instance, most of the circadian clock-oriented experiments wer

  14. Chromosome painting in plants.

    NARCIS (Netherlands)

    Schubert, I.; Fransz, P.F.; Fuchs, J.; Jong, de J.H.

    2001-01-01

    The current 'state-of-art' as to chromosome painting in plants is reviewed. We define different situations described as painting so far: i) Genomic in situ hybridisation (GISH) with total genomic DNA to distinguish alien chromosomes on the basis of divergent dispersed repeats, ii) 'Chromosomal in si

  15. Next Generation Plant Breeding

    NARCIS (Netherlands)

    Goud, J.C.

    2012-01-01

    Van 11-14 november 2012 vond in de Reehorst de conferentie ‘Next Generation Plant Breeding’ plaats. Tijdens deze bijeenkomst kwamen de grote uitdagingen van de toekomstige plantenveredeling aan de orde: de opkomst van nieuwe sequencing-technieken, de bijbehorende enorme hoeveelheid gegevens die gepr

  16. Tetrapyrrole Signaling in Plants

    Science.gov (United States)

    Larkin, Robert M.

    2016-01-01

    Tetrapyrroles make critical contributions to a number of important processes in diverse organisms. In plants, tetrapyrroles are essential for light signaling, the detoxification of reactive oxygen species, the assimilation of nitrate and sulfate, respiration, photosynthesis, and programed cell death. The misregulation of tetrapyrrole metabolism can produce toxic reactive oxygen species. Thus, it is not surprising that tetrapyrrole metabolism is strictly regulated and that tetrapyrrole metabolism affects signaling mechanisms that regulate gene expression. In plants and algae, tetrapyrroles are synthesized in plastids and were some of the first plastid signals demonstrated to regulate nuclear gene expression. In plants, the mechanism of tetrapyrrole-dependent plastid-to-nucleus signaling remains poorly understood. Additionally, some of experiments that tested ideas for possible signaling mechanisms appeared to produce conflicting data. In some instances, these conflicts are potentially explained by different experimental conditions. Although the biological function of tetrapyrrole signaling is poorly understood, there is compelling evidence that this signaling is significant. Specifically, this signaling appears to affect the accumulation of starch and may promote abiotic stress tolerance. Tetrapyrrole-dependent plastid-to-nucleus signaling interacts with a distinct plastid-to-nucleus signaling mechanism that depends on GENOMES UNCUOPLED1 (GUN1). GUN1 contributes to a variety of processes, such as chloroplast biogenesis, the circadian rhythm, abiotic stress tolerance, and development. Thus, the contribution of tetrapyrrole signaling to plant function is potentially broader than we currently appreciate. In this review, I discuss these aspects of tetrapyrrole signaling.

  17. Mechanisms in Plant Development

    Energy Technology Data Exchange (ETDEWEB)

    Hake, Sarah [USDA ARS Plant Gene Expression Center

    2013-08-21

    This meeting has been held every other year for the past twenty-two years and is the only regularly held meeting focused specifically on plant development. Topics covered included: patterning in developing tissues; short and long distance signaling; differentiation of cell types; the role of epigenetics in development; evolution; growth.

  18. Plant breeding and genetics

    Science.gov (United States)

    The ultimate goal of plant breeding is to develop improved crops. Improvements can be made in crop productivity, crop processing and marketing, and/or consumer quality. The process of developing an improved cultivar begins with intercrossing lines with high performance for the traits of interest, th...

  19. Pinellas Plant facts

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1990-11-01

    The Pinellas Plant, near St. Petersburg, Florida, is wholly owned by the United States Government. It is operated for the Department of Energy (DOE) by GE Aerospace, Neutron Devices (GEND). This plant was built in 1956 to manufacture neutron generators, a principal component in nuclear weapons. The neutron generators built at Neutron Devices consist of a miniaturized linear ion accelerator assembled with the pulsed electrical power supplies required for its operation. Production of these devices has necessitated the development of several uniquely specialized areas of competence and supporting facilities. The ion accelerator, or neutron tube, requires ultra clean, high vacuum technology; hermetic seals between glass, ceramic, glass-ceramic, and metal materials; plus high voltage generation and measurement technology. The existence of these capabilities at Neutron Devices has led directly to the assignment of other weapon application products: the lightning arrester connector, specialty capacitor, vacuum switch, and crystal resonator. Other product assignments such as active and reserve batteries and the radioisotopically-powered thermoelectric generator evolved from the plant`s materials measurement and controls technologies which are required to ensure neutron generator life.

  20. Engineered minichromosomes in plants.

    Science.gov (United States)

    Birchler, James A

    2015-02-01

    Engineered minichromosomes have been produced in several plant species via telomere-mediated chromosomal truncation. This approach bypasses the complications of the epigenetic nature of centromere function in plants, which has to date precluded the production of minichromosomes by the re-introduction of centromere sequences to a plant cell. Genes to be added to a cleaved chromosome are joined together with telomere repeats on one side. When these constructs are introduced into plant cells, the genes are ligated to the broken chromosomes but the telomere repeats will catalyze the formation of a telomere on the other end cutting the chromosome at that point. Telomere-mediated chromosomal truncation is sufficiently efficient that very small chromosomes can be generated consisting of basically the endogenous centromere and the added transgenes. The added transgenes provide a platform onto which it should be possible to assemble a synthetic chromosome to specification. Combining engineered minichromosomes with doubled haploid breeding should greatly expedite the transfer of transgenes to new lines and to test the interaction of transgenes in new background genotypes. Potential basic and applied applications of synthetic chromosomes are discussed.

  1. Chromosome painting in plants.

    NARCIS (Netherlands)

    Schubert, I.; Fransz, P.F.; Fuchs, J.; Jong, de J.H.

    2001-01-01

    The current 'state-of-art' as to chromosome painting in plants is reviewed. We define different situations described as painting so far: i) Genomic in situ hybridisation (GISH) with total genomic DNA to distinguish alien chromosomes on the basis of divergent dispersed repeats, ii) 'Chromosomal in

  2. The plant exocyst

    NARCIS (Netherlands)

    Zhang, Y.; Emons, A.M.C.; Ketelaar, T.

    2010-01-01

    exocyst is an octameric vesicle tethering complex that functions upstream of SNARE mediated exocytotic vesicle fusion with the plasma membrane. All proteins in the complex have been conserved during evolution, and genes that encode the exocyst subunits are present in the genomes of all plants invest

  3. Plants and Oxygen

    NARCIS (Netherlands)

    Bailey-Serres, J.N.

    2009-01-01

    In this oratie I will first consider the fundamental nature of oxygen and its role within the plant cell and then will summarize studies on the cellular low-oxygen response that are interwoven with international efforts to provide farmers with rice that endures prolonged periods of complete

  4. Nuclear Power Plant Technician

    Science.gov (United States)

    Randall, George A.

    1975-01-01

    The author recognizes a body of basic knowledge in nuclear power plant technoogy that can be taught in school programs, and lists the various courses, aiming to fill the anticipated need for nuclear-trained manpower--persons holding an associate degree in engineering technology. (Author/BP)

  5. Plant Biotech Lab Manual.

    Science.gov (United States)

    Tant, Carl

    This book provides laboratory experiments to enhance any food science/botany curriculum. Chapter 1, "Introduction," presents a survey of the techniques used in plant biotechnology laboratory procedures. Chapter 2, "Micronutrition," discusses media and nutritional requirements for tissue culture studies. Chapter 3, "Sterile Seeds," focuses on the…

  6. Quantitative plant ecology

    DEFF Research Database (Denmark)

    Damgaard, Christian

    2014-01-01

    This e-book is written in the Wolfram' CDF format (download free CDF player from Wolfram.com) The objective of this e-book is to introduce the population ecological concepts for measuring and predicting the ecological success of plant species. This will be done by focusing on the measurement......, will not be covered in this e-book....

  7. Phenolics and Plant Allelopathy

    Directory of Open Access Journals (Sweden)

    De-An Jiang

    2010-12-01

    Full Text Available Phenolic compounds arise from the shikimic and acetic acid (polyketide metabolic pathways in plants. They are but one category of the many secondary metabolites implicated in plant allelopathy. Phenolic allelochemicals have been observed in both natural and managed ecosystems, where they cause a number of ecological and economic problems, such as declines in crop yield due to soil sickness, regeneration failure of natural forests, and replanting problems in orchards. Phenolic allelochemical structures and modes of action are diverse and may offer potential lead compounds for the development of future herbicides or pesticides. This article reviews allelopathic effects, analysis methods, and allelopathic mechanisms underlying the activity of plant phenolic compounds. Additionally, the currently debated topic in plant allelopathy of whether catechin and 8-hydroxyquinoline play an important role in Centaurea maculata and Centaurea diffusa invasion success is discussed. Overall, the main purpose of this review is to highlight the allelopacthic potential of phenolic compounds to provide us with methods to solve various ecology problems, especially in regard to the sustainable development of agriculture, forestry, nature resources and environment conservation.

  8. Phenolics and plant allelopathy.

    Science.gov (United States)

    Li, Zhao-Hui; Wang, Qiang; Ruan, Xiao; Pan, Cun-De; Jiang, De-An

    2010-12-07

    Phenolic compounds arise from the shikimic and acetic acid (polyketide) metabolic pathways in plants. They are but one category of the many secondary metabolites implicated in plant allelopathy. Phenolic allelochemicals have been observed in both natural and managed ecosystems, where they cause a number of ecological and economic problems, such as declines in crop yield due to soil sickness, regeneration failure of natural forests, and replanting problems in orchards. Phenolic allelochemical structures and modes of action are diverse and may offer potential lead compounds for the development of future herbicides or pesticides. This article reviews allelopathic effects, analysis methods, and allelopathic mechanisms underlying the activity of plant phenolic compounds. Additionally, the currently debated topic in plant allelopathy of whether catechin and 8-hydroxyquinoline play an important role in Centaurea maculata and Centaurea diffusa invasion success is discussed. Overall, the main purpose of this review is to highlight the allelopacthic potential of phenolic compounds to provide us with methods to solve various ecology problems, especially in regard to the sustainable development of agriculture, forestry, nature resources and environment conservation.

  9. Manganese deficiency in plants

    DEFF Research Database (Denmark)

    Schmidt, Sidsel Birkelund; Jensen, Poul Erik; Husted, Søren

    2016-01-01

    Manganese (Mn) is an essential plant micronutrient with an indispensable function as a catalyst in the oxygen-evolving complex (OEC) of photosystem II (PSII). Even so, Mn deficiency frequently occurs without visual leaf symptoms, thereby masking the distribution and dimension of the problem...

  10. Apoplastic interactions between plants and plant root intruders

    Science.gov (United States)

    Mitsumasu, Kanako; Seto, Yoshiya; Yoshida, Satoko

    2015-01-01

    Numerous pathogenic or parasitic organisms attack plant roots to obtain nutrients, and the apoplast including the plant cell wall is where the plant cell meets such organisms. Root parasitic angiosperms and nematodes are two distinct types of plant root parasites but share some common features in their strategies for breaking into plant roots. Striga and Orobanche are obligate root parasitic angiosperms that cause devastating agricultural problems worldwide. Parasitic plants form an invasion organ called a haustorium, where plant cell wall degrading enzymes (PCWDEs) are highly expressed. Plant-parasitic nematodes are another type of agriculturally important plant root parasite. These nematodes breach the plant cell walls by protruding a sclerotized stylet from which PCWDEs are secreted. Responding to such parasitic invasion, host plants activate their own defense responses against parasites. Endoparasitic nematodes secrete apoplastic effectors to modulate host immune responses and to facilitate the formation of a feeding site. Apoplastic communication between hosts and parasitic plants also contributes to their interaction. Parasitic plant germination stimulants, strigolactones, are recently identified apoplastic signals that are transmitted over long distances from biosynthetic sites to functioning sites. Here, we discuss recent advances in understanding the importance of apoplastic signals and cell walls for plant–parasite interactions. PMID:26322059

  11. Evolution of plant senescence

    Directory of Open Access Journals (Sweden)

    Young Mike

    2009-07-01

    Full Text Available Abstract Background Senescence is integral to the flowering plant life-cycle. Senescence-like processes occur also in non-angiosperm land plants, algae and photosynthetic prokaryotes. Increasing numbers of genes have been assigned functions in the regulation and execution of angiosperm senescence. At the same time there has been a large expansion in the number and taxonomic spread of plant sequences in the genome databases. The present paper uses these resources to make a study of the evolutionary origins of angiosperm senescence based on a survey of the distribution, across plant and microbial taxa, and expression of senescence-related genes. Results Phylogeny analyses were carried out on protein sequences corresponding to genes with demonstrated functions in angiosperm senescence. They include proteins involved in chlorophyll catabolism and its control, homeoprotein transcription factors, metabolite transporters, enzymes and regulators of carotenoid metabolism and of anthocyanin biosynthesis. Evolutionary timelines for the origins and functions of particular genes were inferred from the taxonomic distribution of sequences homologous to those of angiosperm senescence-related proteins. Turnover of the light energy transduction apparatus is the most ancient element in the senescence syndrome. By contrast, the association of phenylpropanoid metabolism with senescence, and integration of senescence with development and adaptation mediated by transcription factors, are relatively recent innovations of land plants. An extended range of senescence-related genes of Arabidopsis was profiled for coexpression patterns and developmental relationships and revealed a clear carotenoid metabolism grouping, coordinated expression of genes for anthocyanin and flavonoid enzymes and regulators and a cluster pattern of genes for chlorophyll catabolism consistent with functional and evolutionary features of the pathway. Conclusion The expression and phylogenetic

  12. 边界元-有限差分混合方法在气垫船破冰数值模拟中的应用%Application of mixed BEM and FDM in numerical simulation of ice-breaking by air cushion vehicle

    Institute of Scientific and Technical Information of China (English)

    刘巨斌; 张志宏; 张辽元; 姚俊

    2013-01-01

    A unified mathematical model was set up for different operating conditions (on pure water surface,on pure ice surface,on pure broken ice surface,and on semi-water-semi-ice surface) under which air cushion vehicles(ACV)do ice breaking.The numerical calculation method was based on the combination of BEM and FDM,and C language was applied to developing simulation software,which served the function of calculating the wave-making drag of ACV,wave patterns of water or ice and stresses in ice layer.In this software,INTEL MKL mathematical Lib was used to solve linear equations,and Matlab computing engine was used according to C code,to visualize computational grids and some results.OPENMP option was activated to carry out parallel computation on the multi-core computer.The mathematical model,the computing method and the developed software were proved to be effective by comparing the numerical results of the wave-making drag of ACV on total ice with those of the theoretical analysis and experiments mentioned in the existing documents.%对气垫船破冰作业的几种工况建立了统一的数学模型,提出了采用边界元法与有限差分法相结合的数值计算方法.采用C语言编制数值模拟程序,对气垫船兴波阻力、水面和冰面波形以及冰层内应力进行计算,通过调用Intel MKL数学库求解离散得到线性代数方程组;在C语言中调用Matlab计算引擎实现了计算网格和部分计算结果的显示;在多核计算机上采用OPENMP实现程序关键部分的并行计算,提高了计算速度.气垫船在全冰面上兴波阻力的计算结果与已有文献的理论分析计算结果和试验结果符合较好.

  13. Plant genetics: gene transfer from parasitic to host plants.

    Science.gov (United States)

    Mower, Jeffrey P; Stefanović, Sasa; Young, Gregory J; Palmer, Jeffrey D

    2004-11-11

    Plant mitochondrial genes are transmitted horizontally across mating barriers with surprising frequency, but the mechanism of transfer is unclear. Here we describe two new cases of horizontal gene transfer, from parasitic flowering plants to their host flowering plants, and present phylogenetic and biogeographic evidence that this occurred as a result of direct physical contact between the two. Our findings complement the discovery that genes can be transferred in the opposite direction, from host to parasite plant.

  14. Curvilinear effects of invasive plants on plant diversity: plant community invaded by Sphagneticola trilobata.

    Directory of Open Access Journals (Sweden)

    Shan-Shan Qi

    Full Text Available The effects of invasive plants on the species diversity of plant communities are controversial, showing either a positive or negative linear relationship. Based on community data collected from forty 5 m×5 m plots invaded by Sphagneticola trilobata in eight cities across Hainan Island, China, we found S. trilobata decreased plant community diversity once its cover was beyond 10%. We demonstrated that the effects of invasive/native plants on the plant diversity of communities invaded by S. trilobata were curvilinear. These effects, which showed peaks under different degrees of vegetation cover, appeared not only for S. trilobata and all invasive plants, but also for all native plants. Invasive plants primarily had negative effects on plant diversity when they became abundant at a much lower cover level (less than 35%, compared with the native plants (over 60%. Thus, it is necessary to distinguish a range for assessing the effects of plants, especially invasive plants. Our results also confirmed that the invasion intensity of invasive alien plants increased with the intensity of local economic development. We highlight and further discuss the critical importance of curvilinear effects of biological invasion to provide ideas regarding the conservation of local biodiversity and the management of invasive plants.

  15. Curvilinear effects of invasive plants on plant diversity: plant community invaded by Sphagneticola trilobata.

    Science.gov (United States)

    Qi, Shan-Shan; Dai, Zhi-Cong; Zhai, De-Li; Chen, Si-Chong; Si, Chun-Can; Huang, Ping; Wang, Rui-Ping; Zhong, Qiong-Xin; Du, Dao-Lin

    2014-01-01

    The effects of invasive plants on the species diversity of plant communities are controversial, showing either a positive or negative linear relationship. Based on community data collected from forty 5 m×5 m plots invaded by Sphagneticola trilobata in eight cities across Hainan Island, China, we found S. trilobata decreased plant community diversity once its cover was beyond 10%. We demonstrated that the effects of invasive/native plants on the plant diversity of communities invaded by S. trilobata were curvilinear. These effects, which showed peaks under different degrees of vegetation cover, appeared not only for S. trilobata and all invasive plants, but also for all native plants. Invasive plants primarily had negative effects on plant diversity when they became abundant at a much lower cover level (less than 35%), compared with the native plants (over 60%). Thus, it is necessary to distinguish a range for assessing the effects of plants, especially invasive plants. Our results also confirmed that the invasion intensity of invasive alien plants increased with the intensity of local economic development. We highlight and further discuss the critical importance of curvilinear effects of biological invasion to provide ideas regarding the conservation of local biodiversity and the management of invasive plants.

  16. Effect of plant growth regulators on callus induction and plant ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-06-03

    Jun 3, 2009 ... Effect of plant growth regulators on callus induction and plant ... MS media supplemented with different levels of BA and TDZ were employed for shoot ... acre many times that of any grain crop (Burton, 1969) and are used in a ... plant regeneration from explants require the presence of .... light green. 2.50 ± ...

  17. Plant responses to plant growth-promoting rhizobacteria

    NARCIS (Netherlands)

    Loon, L.C. van

    2007-01-01

    Non-pathogenic soilborne microorganisms can promote plant growth, as well as suppress diseases. Plant growth promotion is taken to result from improved nutrient acquisition or hormonal stimulation. Disease suppression can occur through microbial antagonism or induction of resistance in the plant. Se

  18. Plant responses to plant growth-promoting rhizobacteria

    NARCIS (Netherlands)

    Loon, L.C. van

    2007-01-01

    Non-pathogenic soilborne microorganisms can promote plant growth, as well as suppress diseases. Plant growth promotion is taken to result from improved nutrient acquisition or hormonal stimulation. Disease suppression can occur through microbial antagonism or induction of resistance in the plant.

  19. Woody plants and woody plant management: ecology, safety, environmental impact

    Science.gov (United States)

    James H. Miller

    2001-01-01

    Wise and effective woody plant management is an increasing necessity for many land uses and conservation practices, especially on forests and rangelands where native or exotic plants are affecting productivity, access, or critical habitat. Tools and approaches for managing woody plants have been under concerted development for the past 50 years, integrating mechanical...

  20. Evaluating plant and plant oil repellency against the sweetpotato whitefly

    Science.gov (United States)

    The sweetpotato whitefly, Bemisia tabaci is a major insect pest of vegetables world-wide. We evaluated the effect of commercial plant oils – garlic oil, hot pepper wax, and mustard oil against B. tabaci. Cucumber plants served as the control. Additional treatments included no plants or oil (clear ai...