WorldWideScience

Sample records for earth walls

  1. Flooding Effect on Earth Walls

    Directory of Open Access Journals (Sweden)

    Meysam Banimahd

    2010-12-01

    Full Text Available Earth building is a sustainable, environmentally friendly and economical method of construction that has been used worldwide for many centuries. For the past three decades, earth has seen a revival as a building material for a modern construction method due to its benefits in terms of low carbon content, low cost and energy involved during construction, as well as the fact that it is a sustainable technology of building. Climate change is influencing precipitation levels and patterns around the world, and as a consequence, flood risk is increasing rapidly. When flooding occurs, earth buildings are exposed to water by submersion, causing an increase in the degree of saturation of the earth structures and therefore a decrease of the suction between particles. This study investigated the effect of cycles of flooding (consecutive events of flooding followed by dry periods on earth walls. A series of characterization tests were carried out to obtain the physical and mechanical properties of the studied earth material. In a second stage, Flooding Simulation Tests (FST were performed to explore the earth walls’ response to repeated flooding events. The results obtained for the tested earth wall/samples with reinforced material (straw reveal hydraulic hysteresis when wall/samples are subject to cycles of wetting and drying.

  2. Designing and building walls with Rammed Earth

    NARCIS (Netherlands)

    Galiouna, E.A.; Hammer, L.; Piscitelli, G.

    2014-01-01

    This "designers' manual" is made during the TIDO-course AR0533 Innovation & Sustainability. Today, a lot of people in the world live in earth dwellings. There are many different techniques for constructing solid walls of raw earth (adobe, bale, cob, mud wall, light clay, wattle and daub, earth bags

  3. Designing and building walls with Rammed Earth

    NARCIS (Netherlands)

    Galiouna, E.A.; Hammer, L.; Piscitelli, G.

    2014-01-01

    This "designers' manual" is made during the TIDO-course AR0533 Innovation & Sustainability. Today, a lot of people in the world live in earth dwellings. There are many different techniques for constructing solid walls of raw earth (adobe, bale, cob, mud wall, light clay, wattle and daub, earth

  4. Evaluating rammed earth walls: a case study

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, P. [Deakin University, Geelong (Australia). Built Environment Research Group; La Trobe University, Wodonga (Australia); Luther, M.B. [Deakin University, Geelong (Australia). Built Environment Research Group

    2004-03-01

    The following research has been undertaken as a response to the recent controversy regarding the suitability of rammed earth wall construction as an effective building envelope in regard to its thermal performance. The R-value for rammed earth walls is low hence they might be expected to conduct heat into a building during summer. However the large mass of these walls and the associated thermal lag in heat transfer from outside to inside may result in the walls performing satisfactorily in a building which is only occupied during working hours. Internal rammed earth walls may act as moderators of large diurnal temperature swings helping to produce an even comfortable temperature within a building. Empirical (in situ) measurements of temperature and heat flux were taken on the walls of an existing rammed earth office building in New South Wales, Australia during the summer. An analysis was performed which established a methodology to measure the heat flow associated with the walls, floor, ceiling, windows and infiltration for one office during occupied hours and the net energy transferred between the office and these elements was established. During this time the earth walls performed well. External walls were found to transmit comparatively little heat to the office and the internal walls absorbed heat during this time. Diffuse sky radiation transmitted by the window and infiltration are both likely to be important factors in the summer heat load. (author)

  5. Ferroelectricity of domain walls in rare earth iron garnet films.

    Science.gov (United States)

    Popov, A I; Zvezdin, K A; Gareeva, Z V; Mazhitova, F A; Vakhitov, R M; Yumaguzin, A R; Zvezdin, A K

    2016-11-16

    In this paper, we report on electric polarization arising in a vicinity of Bloch-like domain walls in rare-earth iron garnet films. The domain walls generate an intrinsic magnetic field that breaks an antiferroelectric structure formed in the garnets due to an exchange interaction between rare earth and iron sublattices. We explore 180° domain walls whose formation is energetically preferable in the films with perpendicular magnetic anisotropy. Magnetic and electric structures of the 180° quasi-Bloch domain walls have been simulated at various relations between system parameters. Singlet, doublet ground states of rare earth ions and strongly anisotropic rare earth Ising ions have been considered. Our results show that electric polarization appears in rare earth garnet films at Bloch domain walls, and the maximum of magnetic inhomogeneity is not always linked to the maximum of electric polarization. A number of factors including the temperature, the state of the rare earth ion and the type of a wall influence magnetically induced electric polarization. We show that the value of polarization can be enhanced by the shrinking of the Bloch domain wall width, decreasing the temperature, and increasing the deviations of magnetization from the Bloch rotation that are regulated by impacts given by magnetic anisotropies of the films.

  6. Ferroelectricity of domain walls in rare earth iron garnet films

    Science.gov (United States)

    Popov, A. I.; Zvezdin, K. A.; Gareeva, Z. V.; Mazhitova, F. A.; Vakhitov, R. M.; Yumaguzin, A. R.; Zvezdin, A. K.

    2016-11-01

    In this paper, we report on electric polarization arising in a vicinity of Bloch-like domain walls in rare-earth iron garnet films. The domain walls generate an intrinsic magnetic field that breaks an antiferroelectric structure formed in the garnets due to an exchange interaction between rare earth and iron sublattices. We explore 180° domain walls whose formation is energetically preferable in the films with perpendicular magnetic anisotropy. Magnetic and electric structures of the 180° quasi-Bloch domain walls have been simulated at various relations between system parameters. Singlet, doublet ground states of rare earth ions and strongly anisotropic rare earth Ising ions have been considered. Our results show that electric polarization appears in rare earth garnet films at Bloch domain walls, and the maximum of magnetic inhomogeneity is not always linked to the maximum of electric polarization. A number of factors including the temperature, the state of the rare earth ion and the type of a wall influence magnetically induced electric polarization. We show that the value of polarization can be enhanced by the shrinking of the Bloch domain wall width, decreasing the temperature, and increasing the deviations of magnetization from the Bloch rotation that are regulated by impacts given by magnetic anisotropies of the films.

  7. DISTRIBUTION OF ACTIVE EARTH PRESSURE OF RETAINING WALL WITH WALL MOVEMENT OF ROTATION ABOUT TOP

    Institute of Scientific and Technical Information of China (English)

    王元战; 唐照评; 郑斌

    2004-01-01

    Based on the Coulomb' s theory that the earth pressure against the back of a retaining wall is due to the thrust exerted by the sliding wedge of soil from the back of the wall to a plane which passes through the bottom edge of the wall and has an inclination equal to the angle of θ, the theoretical answers to the unit earth pressure, the resultant earth pressure and the point of application of the resultant earth pressure on a retaining wall were obtained for the wall movement mode of rotation about top. The comparisons were made among the formula presented here, the formula for the wall movement mode of translation,the Coulomb' s formula and some experimental observations. It is demonstrated that the magnitudes of the resultant earth pressures for the wall movement mode of rotation about top is equal to that determined by the formula for the wall movement mode of translation and the Coulomb' s theory. But the distribution of the earth pressure and the points of application of the resultant earth pressures have significant difference.

  8. Kinematic framework for evaluating seismic earth pressures on retaining walls

    OpenAIRE

    Brandenberg, Scott J.; Mylonakis, George; Stewart, Jonathan P.

    2015-01-01

    © 2015 American Society of Civil Engineers.During earthquake ground shaking earth pressures on retaining structures can cyclically increase and decrease as a result of inertial forces applied to the walls and kinematic interactions between the stiff wall elements and surrounding soil. The application, based on limit equilibrium analysis, of a pseudostatic inertial force to a soil wedge behind the wall [the mechanism behind the widely-used Mononobe- Okabe (M-O) method] is a poor analogy for ei...

  9. Embodied energy in cement stabilised rammed earth walls

    Energy Technology Data Exchange (ETDEWEB)

    Venkatarama Reddy, B.V.; Prasanna Kumar, P. [Department of Civil Engineering, Indian Institute of Science, Bangalore 560012 (India)

    2010-03-15

    Rammed earth walls are low carbon emission and energy efficient alternatives to load bearing walls. Large numbers of rammed earth buildings have been constructed in the recent past across the globe. This paper is focused on embodied energy in cement stabilised rammed earth (CSRE) walls. Influence of soil grading, density and cement content on compaction energy input has been monitored. A comparison between energy content of cement and energy in transportation of materials, with that of the actual energy input during rammed earth compaction in the actual field conditions and the laboratory has been made. Major conclusions of the investigations are (a) compaction energy increases with increase in clay fraction of the soil mix and it is sensitive to density of the CSRE wall, (b) compaction energy varies between 0.033 MJ/m{sup 3} and 0.36 MJ/m{sup 3} for the range of densities and cement contents attempted, (c) energy expenditure in the compaction process is negligible when compared to energy content of the cement and (d) total embodied energy in CSRE walls increases linearly with the increase in cement content and is in the range of 0.4-0.5 GJ/m{sup 3} for cement content in the rage of 6-8%. (author)

  10. Modeling rammed earth wall using discrete element method

    Science.gov (United States)

    Bui, T.-T.; Bui, Q.-B.; Limam, A.; Morel, J.-C.

    2016-03-01

    Rammed earth is attracting renewed interest throughout the world thanks to its "green" characteristics in the context of sustainable development. Several research studies have thus recently been carried out to investigate this material. Some of them attempted to simulate the rammed earth's mechanical behavior by using analytical or numerical models. Most of these studies assumed that there was a perfect cohesion at the interface between earthen layers. This hypothesis proved to be acceptable for the case of vertical loading, but it could be questionable for horizontal loading. To address this problem, discrete element modeling seems to be relevant to simulate a rammed earth wall. To our knowledge, no research has been conducted thus far using discrete element modeling to study a rammed earth wall. This paper presents an assessment of the discrete element modeling's robustness for rammed earth walls. Firstly, a brief description of the discrete element modeling is presented. Then the parameters necessary for discrete element modeling of the material law of the earthen layers and their interfaces law following the Mohr-Coulomb model with a tension cut-off and post-peak softening were given. The relevance of the model and the material parameters were assessed by comparing them with experimental results from the literature. The results showed that, in the case of vertical loading, interfaces did not have an important effect. In the case of diagonal loading, model with interfaces produced better results. Interface characteristics can vary from 85 to 100% of the corresponding earthen layer's characteristics.

  11. Field Measurements and Pullout Tests of Reinforced Earth Retaining Wall

    Institute of Scientific and Technical Information of China (English)

    陈群; 何昌荣; 朱分清

    2004-01-01

    In this paper, field measurements and pullout tests of a new type of reinforced earth retaining wall, which is reinforced by trapezoid concrete blocks connected by steel bar, are described. Field measurements included settlements of the earth fill, tensile forces in the ties and earth pressures on the facing panels during the construction and at completion. Based on the measurements, the following statements can be made: ( 1 ) the tensile forces in the ties increased with the height of backfill above the tie and there is a tensile force crest in most ties; (2) at completion, the measured earth pressures along the wall face were between the values of the active earth pressures and the pressures at rest; (3) larger settlements occurred near the face of the wall where a zone of drainage sand and gravel was not compacted properly and smaller settlements occurred in the well-compacted backfill. The results of field pullout tests indicated that the magnitudes of pullout resistances as well as tensile forces induced in the ties were strongly influenced by the relative displacements between the ties and the backfill, and pullout resistances increased with the height of backfill above the ties and the length of ties.

  12. Evolution of the Stability Work from Classic Retaining Walls to Mechanically Stabilized Earth Walls

    Directory of Open Access Journals (Sweden)

    Anghel Stanciu

    2008-01-01

    Full Text Available For the consolidation of soil mass and the construction of the stability works for roads infrastructure it was studied the evolution of these kinds of works from classical retaining walls - common concrete retaining walls, to the utilization in our days of the modern and competitive methods - mechanically stabilized earth walls. Like type of execution the variety of the reinforced soil is given by the utilization of different types of reinforcing inclusions (steel strips, geosynthetics, geogrids or facing (precast concrete panels, dry cast modular blocks, metal sheets and plates, gabions, and wrapped sheets of geosynthetics.

  13. Electrical resisitivity of mechancially stablized earth wall backfill

    Science.gov (United States)

    Snapp, Michael; Tucker-Kulesza, Stacey; Koehn, Weston

    2017-06-01

    Mechanically stabilized earth (MSE) retaining walls utilized in transportation projects are typically backfilled with coarse aggregate. One of the current testing procedures to select backfill material for construction of MSE walls is the American Association of State Highway and Transportation Officials standard T 288: ;Standard Method of Test for Determining Minimum Laboratory Soil Resistivity.; T 288 is designed to test a soil sample's electrical resistivity which correlates to its corrosive potential. The test is run on soil material passing the No. 10 sieve and believed to be inappropriate for coarse aggregate. Therefore, researchers have proposed new methods to measure the electrical resistivity of coarse aggregate samples in the laboratory. There is a need to verify that the proposed methods yield results representative of the in situ conditions; however, no in situ measurement of the electrical resistivity of MSE wall backfill is established. Electrical resistivity tomography (ERT) provides a two-dimensional (2D) profile of the bulk resistivity of backfill material in situ. The objective of this study was to characterize bulk resistivity of in-place MSE wall backfill aggregate using ERT. Five MSE walls were tested via ERT to determine the bulk resistivity of the backfill. Three of the walls were reinforced with polymeric geogrid, one wall was reinforced with metallic strips, and one wall was a gravity retaining wall with no reinforcement. Variability of the measured resistivity distribution within the backfill may be a result of non-uniform particle sizes, thoroughness of compaction, and the presence of water. A quantitative post processing algorithm was developed to calculate mean bulk resistivity of in-situ backfill. Recommendations of the study were that the ERT data be used to verify proposed testing methods for coarse aggregate that are designed to yield data representative of in situ conditions. A preliminary analysis suggests that ERT may be utilized

  14. Investigation into the variations of moisture content of two buildings constructed with light earth walls

    OpenAIRE

    Goodhew, S; Griffiths, R; Morgan, C.

    2005-01-01

    This paper briefly describes the background to light earth buildings and details a series of moisture measurements undertaken upon the clay and straw, (light earth) constructed walls of two UK based buildings. The methodology of measurement that was based upon previous studies undertaken on walls made from straw bales is described. A novel ‘in-wall’ wet heating system used in one of the two buildings allows the investigation of the effects of direct wall heating upon the distribution of moist...

  15. Dilation effect on 3D Passive Earth Pressure Coefficients for Retaining Wall

    OpenAIRE

    Khelifa, Tarek; Benmebarek, Sadok

    2015-01-01

    The 2D passive earth pressures acting on rigid retaining walls problem has been widely treated in the literature using different approaches (limit equilibrium, limit analysis, slip line and numerical computation), however, the 3D passive earth pressures problem has received less attention. This paper is concerned with the numerical study of 3D passive earth pressures induced by the translation of a rigid rough retaining wall for associated and non-associated soils. Using the explicit finite d...

  16. Dilation effect on 3D Passive Earth Pressure Coefficients for Retaining Wall

    OpenAIRE

    Khelifa, Tarek; Benmebarek, Sadok

    2014-01-01

    The 2D passive earth pressures acting on rigid retaining walls problem has been widely treated in the literature using different approaches (limit equilibrium, limit analysis, slip line and numerical computation), however, the 3D passive earth pressures problem has received less attention. This paper is concerned with the numerical study of 3D passive earth pressures induced by the translation of a rigid rough retaining wall for associated and non-associated soils. Using the explicit finite d...

  17. Seismic Earth Pressure Development in Sheet Pile Retaining Walls: A Numerical Study

    CERN Document Server

    Rajeev, P; Sivakugan, N

    2015-01-01

    The design of retaining walls requires the complete knowledge of the earth pressure distribution behind the wall. Due to the complex soil-structure effect, the estimation of earth pressure is not an easy task; even in the static case. The problem becomes even more complex for the dynamic (i.e., seismic) analysis and design of retaining walls. Several earth pressure models have been developed over the years to integrate the dynamic earth pressure with the static earth pressure and to improve the design of retaining wall in seismic regions. Among all the models, MononobeOkabe (M-O) method is commonly used to estimate the magnitude of seismic earth pressures in retaining walls and is adopted in design practices around the world (e.g., EuroCode and Australian Standards). However, the M-O method has several drawbacks and does not provide reliable estimate of the earth pressure in many instances. This study investigates the accuracy of the M-O method to predict the dynamic earth pressure in sheet pile wall. A 2D pl...

  18. Seismic earth pressures on flexible cantilever retaining walls with deformable inclusions

    Directory of Open Access Journals (Sweden)

    Ozgur L. Ertugrul

    2014-10-01

    Full Text Available In this study, the results of 1-g shaking table tests performed on small-scale flexible cantilever wall models retaining composite backfill made of a deformable geofoam inclusion and granular cohesionless material were presented. Two different polystyrene materials were utilized as deformable inclusions. Lateral dynamic earth pressures and wall displacements at different elevations of the retaining wall model were monitored during the tests. The earth pressures and displacements of the retaining walls with deformable inclusions were compared with those of the models without geofoam inclusions. Comparisons indicated that geofoam panels of low stiffness installed against the retaining wall model affect displacement and dynamic lateral pressure profile along the wall height. Depending on the inclusion characteristics and the wall flexibility, up to 50% reduction in dynamic earth pressures was observed. The efficiency of load and displacement reduction decreased as the flexibility ratio of the wall model increased. On the other hand, dynamic load reduction efficiency of the deformable inclusion increased as the amplitude and frequency ratio of the seismic excitation increased. Relative flexibility of the deformable layer (the thickness and the elastic stiffness of the polystyrene material played an important role in the amount of load reduction. Dynamic earth pressure coefficients were compared with those calculated with an analytical approach. Pressure coefficients calculated with this method were found to be in good agreement with the results of the tests performed on the wall model having low flexibility ratio. It was observed that deformable inclusions reduce residual wall stresses observed at the end of seismic excitation thus contributing to the post-earthquake stability of the retaining wall. The graphs presented within this paper regarding the dynamic earth pressure coefficients versus the wall flexibility and inclusion characteristics may

  19. Seismic earth pressures on flexible cantilever retaining walls with deformable inclusions

    Institute of Scientific and Technical Information of China (English)

    Ozgur L. Ertugrul; Aurelian C. Trandafir

    2014-01-01

    In this study, the results of 1-g shaking table tests performed on small-scale flexible cantilever wall models retaining composite backfill made of a deformable geofoam inclusion and granular cohesionless material were presented. Two different polystyrene materials were utilized as deformable inclusions. Lateral dynamic earth pressures and wall displacements at different elevations of the retaining wall model were monitored during the tests. The earth pressures and displacements of the retaining walls with deformable inclusions were compared with those of the models without geofoam inclusions. Comparisons indicated that geofoam panels of low stiffness installed against the retaining wall model affect displacement and dynamic lateral pressure profile along the wall height. Depending on the in-clusion characteristics and the wall flexibility, up to 50% reduction in dynamic earth pressures was observed. The efficiency of load and displacement reduction decreased as the flexibility ratio of the wall model increased. On the other hand, dynamic load reduction efficiency of the deformable inclusion increased as the amplitude and frequency ratio of the seismic excitation increased. Relative flexibility of the deformable layer (the thickness and the elastic stiffness of the polystyrene material) played an important role in the amount of load reduction. Dynamic earth pressure coefficients were compared with those calculated with an analytical approach. Pressure coefficients calculated with this method were found to be in good agreement with the results of the tests performed on the wall model having low flexibility ratio. It was observed that deformable inclusions reduce residual wall stresses observed at the end of seismic excitation thus contributing to the post-earthquake stability of the retaining wall. The graphs presented within this paper regarding the dynamic earth pressure coefficients versus the wall flexibility and inclusion characteristics may serve for the

  20. Interaction analysis of back-to-back mechanically stabilized earth walls

    Institute of Scientific and Technical Information of China (English)

    Sadok Benmebarek; Samir Attallaoui; Naïma Benmebarek

    2016-01-01

    Back-to-back mechanically stabilized earth walls (BBMSEWs) are encountered in bridge approaches, ramp ways, rockfall protection systems, earth dams, levees and noise barriers. However, available design guidelines for BBMSEWs are limited and not applicable to numerical modeling when back-to-back walls interact with each other. The objective of this paper is to investigate, using PLAXIS code, the effects of the reduction in the distance between BBMSEW, the reinforcement length, the quality of backfill material and the connection of reinforcements in the middle, when the back-to-back walls are close. The results indicate that each of the BBMSEWs behaves independently if the width of the embankment between mechanically stabilized earth walls is greater than that of the active zone. This is in good agreement with the result of FHWA design guideline. However, the results show that the FHWA design guideline un-derestimates the lateral earth pressure when back-to-back walls interact with each other. Moreover, for closer BBMSEWs, FHWA design guideline strongly overestimates the maximum tensile force in the reinforcement. The investigation of the quality of backfill material shows that the minor increase in embankment cohesion can lead to significant reductions in both the lateral earth pressure and the maximum tensile force in geosynthetic. When the distance between the two earth walls is close to zero, the connection of reinforcement between back-to-back walls significantly improves the factor of safety.

  1. Interaction analysis of back-to-back mechanically stabilized earth walls

    Directory of Open Access Journals (Sweden)

    Sadok Benmebarek

    2016-10-01

    Full Text Available Back-to-back mechanically stabilized earth walls (BBMSEWs are encountered in bridge approaches, ramp ways, rockfall protection systems, earth dams, levees and noise barriers. However, available design guidelines for BBMSEWs are limited and not applicable to numerical modeling when back-to-back walls interact with each other. The objective of this paper is to investigate, using PLAXIS code, the effects of the reduction in the distance between BBMSEW, the reinforcement length, the quality of backfill material and the connection of reinforcements in the middle, when the back-to-back walls are close. The results indicate that each of the BBMSEWs behaves independently if the width of the embankment between mechanically stabilized earth walls is greater than that of the active zone. This is in good agreement with the result of FHWA design guideline. However, the results show that the FHWA design guideline underestimates the lateral earth pressure when back-to-back walls interact with each other. Moreover, for closer BBMSEWs, FHWA design guideline strongly overestimates the maximum tensile force in the reinforcement. The investigation of the quality of backfill material shows that the minor increase in embankment cohesion can lead to significant reductions in both the lateral earth pressure and the maximum tensile force in geosynthetic. When the distance between the two earth walls is close to zero, the connection of reinforcement between back-to-back walls significantly improves the factor of safety.

  2. Influence of EPS Geofoam Buffers on the Static Behavior of Cantilever Earth-Retaining Walls

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    Özgür L. Ertuğrul

    2012-03-01

    Full Text Available In this study, the effect of expanded polystyrene (EPS buffers on lateral stresses and deflections of model retaining walls with various flexibility values were investigated. For this purpose, 0.7 m high model walls were instrumented and 1-g model tests were performed in laboratory environment. In the first group of tests, the wall models retain only granular cohesionless backfill whereas in the second and third group of tests, EPS deformable buffers of two different thicknesses were installed between the wall and granular backfill. Tests were repeated for four different wall thicknesses and results were discussed comparatively. As wall flexibility increases, there is a decrease in the load reduction pattern of the buffer. On the other hand, utilization of geofoam buffers with flexible cantilever walls still provides substantial decrease in wall thrust and deflections thus leading to more economical retaining structure design. The lateral earth pressure coefficients determined through model tests were compared to those calculated from Coulomb's theory for active lateral earth stresses. A graph is provided for the estimation of lateral earth pressure coefficients for various combinations of wall flexibilities and buffer characteristics.

  3. Evaluation of air lime and clayish earth mortars for earthen wall renders

    OpenAIRE

    Faria, Paulina; Silva, Vitor; Jamú, Naila; Dias, Inês; Gomes, M. Idália

    2013-01-01

    CIAV2013 – International Conference on Vernacular Architecture, 7º ATP, VerSus, 16-20 october 2013 An experimental rammed earth wall was traditionally made with local earth and characterized in terms of superficial hardness, compactness, thermal conductivity and water absorption, in exterior environmental conditions. Two mortars were made with an air lime and a mixture of three washed graduated siliceous sands, with volumetric proportions of 1:2 and 1:3 (air lime:sand). A clayish earth was...

  4. Rammed earth - a sustainable wall system for the Pacific North-West

    Energy Technology Data Exchange (ETDEWEB)

    Krayenhoff, M; White, E.

    1997-07-01

    Construction of a stabilized rammed earth wall (SRE), which consists of a mixture of unwashed, unscreened sandy aggregate and cement, reinforced with bamboo and insulated with vermiculite or foam board, was described, and its performance reviewed. Although not popular in Canada in general, rammed earth wall construction is being used for custom homes in British Columbia`s Gulf Islands. France and Australia are also active in the development of rammed earth wall technologies. The base SRE house is 1500 sq ft, single storey slab-on grade, with the long axis oriented east-west. SRE houses have a very long life expectancy, (estimated 100 to 1,000 years). There are no exterior or interior surfaces to be painted, or replaced. The material is highly resistant to mechanical damage. Construction cost is higher than frame wall construction, but maintenance cost, space heating energy cost, environmental impact cost, and local economic benefit are all greater than traditional frame construction (the latter because of the high labour requirement and high local materials component). Insulated rammed earth wall construction is considered to be a technically sound exterior wall system, especially in the milder climate of the Pacific Northwest. Because of the higher thermal mass, a greater passive solar contribution is also expected from a rammed earth house.

  5. Lateral Earth Pressure behind Walls Rotating about Base considering Arching Effects

    Directory of Open Access Journals (Sweden)

    Dong Li

    2014-01-01

    Full Text Available In field, the earth pressure on a retaining wall is the common effect of kinds of factors. To figure out how key factors act, it has taken into account the arching effects together with the contribution from the mode of displacement of a wall to calculate earth pressure in the proposed method. Based on Mohr circle, a conversion factor is introduced to determine the shear stresses between artificial slices in soil mass. In the light of this basis, a modified differential slices solution is presented for calculation of active earth pressure on a retaining wall. Comparisons show that the result of proposed method is identical to observations from model tests in prediction of lateral pressures for walls rotating about the base.

  6. Experimental Study of Cement Mortar-Steel Fiber Reinforced Rammed Earth Wall

    Directory of Open Access Journals (Sweden)

    Shuai Yang

    2012-10-01

    Full Text Available Rammed earth construction is an ancient technique which has recently attracted renewed interest throughout the world. Although rammed earth is currently regarded as a promising material in the construction industry in the context of sustainable development, it is difficult to quantify its bearing capacity, mechanical performance, as well as retrofitting approach, which discourages people from large-scale application in architectural engineering. This paper is devoted to the study of these problems based on rammed earth wall model experimentation. Three different models are studied considering different material components as well as structural configurations. By measuring the strain and deformation of the rammed earth wall models subjected to uniformly-distributed vertical loading, their ultimate bearing capacities are tested based on experimental investigation. Then the method of cement mortar-steel fiber reinforcement (CMSF is carried out to study the ultimate bearing capacity enhancement of the wall models. Results show that the method of cement mortar-steel fiber reinforcement can increase the ultimate bearing capacity of the rammed earth wall models significantly, which is of relevant engineering significance in practical application.

  7. Composition of Bamboo Walls and Compressed Earth Block Walls in a Simple House that Produces Energy Efficient to Heat and Embodied Energy in Indonesia

    Directory of Open Access Journals (Sweden)

    Vincentius Totok NOERWASITO

    2016-08-01

    Full Text Available Building materials have a major effect on the depletion of natural resources and energy in the world. Local raw materials are some of the best building materials, which can be found in every location; for example, compressed earth block and bamboo. This study adds to previous studies on compressed earth blocks without using combustion in the same location. The study focused on how to obtain a rural housing design by using compressed earth block walls and bamboo walls, which are adaptive to local materials and climate. Moreover, the ratio of the use of the compressed earth block walls with the walls is also examined to produce optimum embodied energy and heat energy buildings. The method used in this study was to analyze the characteristics of the compressed earth block and bamboo materials used as wall construction. While embodied energy and heat energy were calculated by using simulation model building, the heat energy calculation was found using the Archipak program. The results of the study shows that the optimum wall materials for the embodied energy and heat energy was compressed earth block with an area of 11 m2 and bamboo walls with an area of 19 m2.

  8. Physical and numerical modelling of earth pressure on anchored sheet pile walls in sand

    DEFF Research Database (Denmark)

    Krogsbøll, Anette Susanne; Fuglsang, Leif D

    2006-01-01

    The influence of wall flexibility on earth pressure, bending moments and failure modes is studied. Numerical models are compared to results from model tests carried out in a geotechnical centrifuge. The back-fill is dry sand and failure is introduced by allowing the wall to rotate around the anchor...... level. The Finite element program PLAXIS is used and two material models are evaluated, the Mohr-Coulomb model and the Hardening Soil model. The differences between the two concern the deformation properties. Generally good agreement was observed between physical and numerical models. The HS-model...... showed the right behaviour in pre-failure as well as failure for both flexible and stiff walls, whereas the MC-model showed some shortcomings when stiff walls were modelled....

  9. Physical and numerical modelling of earth pressure on anchored sheet pile walls in sand

    DEFF Research Database (Denmark)

    Krogsbøll, Anette Susanne; Fuglsang, Leif D

    The influence of wall flexibility on earth pressure, bending moments and failure modes is studied. Numerical models are compared to results from model tests carried out in a geotechnical centrifuge. The back-fill is dry sand and failure is introduced by allowing the wall to rotate around the anchor...... level. The Finite element program PLAXIS is used and two material models are evaluated, the Mohr-Coulomb model and the Hardening Soil model. The differences between the two concern the deformation properties. Generally good agreement was observed between physical and numerical models. The HS-model...... showed the right behaviour in pre-failure as well as failure for both flexible and stiff walls, whereas the MC-model showed some shortcomings when stiff walls were modelled....

  10. A Procedure to Measure the in-Situ Hygrothermal Behavior of Earth Walls

    Directory of Open Access Journals (Sweden)

    Pierre-Antoine Chabriac

    2014-04-01

    Full Text Available Rammed earth is a sustainable material with low embodied energy. However, its development as a building material requires a better evaluation of its moisture-thermal buffering abilities and its mechanical behavior. Both of these properties are known to strongly depend on the amount of water contained in wall pores and its evolution. Thus the aim of this paper is to present a procedure to measure this key parameter in rammed earth or cob walls by using two types of probes operating on the Time Domain Reflectometry (TDR principle. A calibration procedure for the probes requiring solely four parameters is described. This calibration procedure is then used to monitor the hygrothermal behavior of a rammed earth wall (1.5 m × 1 m × 0.5 m, instrumented by six probes during its manufacture, and submitted to insulated, natural convection and forced convection conditions. These measurements underline the robustness of the calibration procedure over a large range of water content, even if the wall is submitted to quite important temperature variations. They also emphasize the importance of gravity on water content heterogeneity when the saturation is high, as well as the role of liquid-to-vapor phase change on the thermal behavior.

  11. Effectiveness of GeoWall Visualization Technology for Conceptualization of the Sun-Earth-Moon System

    Science.gov (United States)

    Turner, N. E.; Gray, C.; Mitchell, E. J.

    2004-12-01

    One persistent difficulty many introductory astronomy students face is the lack of a 3-dimensional mental model of the Earth-Moon system. Students without such a mental model can have a very hard time conceptualizing the geometric relationships that cause the cycle of lunar phases. The GeoWall is a recently developed and affordable projection mechanism for three-dimensional stereo visualization which is becoming a popular tool in classrooms and research labs. We present results from a study using a 3-D GeoWall with a simulated sunlit Earth-Moon system on undergraduate students' ability to understand the origins of lunar phases. We test students exposed to only in-class instruction, some with a laboratory exercise using the GeoWall Earth-Moon simulation, some students who were exposed to both, and some with an alternate activity involving lunar observations. Students are given pre and post tests using the a diagnostic test called the Lunar Phase Concept Inventory (LPCI). We discuss the effectiveness of this technology as a teaching tool for lunar phases.

  12. 加筋土挡土墙结构的应用%Application of Reinforced Earth Retaining Wall Structure

    Institute of Scientific and Technical Information of China (English)

    黄国伟; 方鸿琪

    2000-01-01

    After 30 years of research and development the reinforced earth, invented by French Henri Vidal, is now widely used in the field of civil engineering. Researches and projects conducted by Reinforced Earth Group in the respect of reinforced earth are presented herein. The projects involve retaining wall for high speed highway, abutment, railway embankment, river weir, flood protection dike and retaining walls for industrial and military purposes. More than ten thousand sturdy and durable retaining walls of reinforced earth are built around the world.%法国人亨利·维特(Henri Vidal) 发明的加筋土经过30年的研究和发展,现已广泛用于土木工程领域。本文介绍了Reinforced Earth集团在加筋土方面的研究及项目情况,其项目领域涉及高速公路挡土墙、桥台、铁路路堤、河堤、水坝、防洪堤、工业及军事用途挡土墙等。在世界各地建造了1万多幅坚固耐用的加筋土墙。

  13. Capacity of unreinforced rammed earth walls subject to lateral wind force: elastic analysis versus ultimate strength analysis.

    OpenAIRE

    Ciancio, D.; Augarde, C.

    2013-01-01

    Cement-stabilized rammed earth walls are an increasingly common form of construction in certain parts of the world, bringing considerable potential to reduce the carbon footprints of buildings. However, there is relatively little advice to designers wishing to use these construction materials at present, as compared to established materials such as concrete. This paper discusses the use of two proposed analysis procedures to calculate the capacity of unreinforced cement-stabilized rammed eart...

  14. Assessing the environmental performance of stabilised rammed earth walls using a climatic simulation chamber

    Energy Technology Data Exchange (ETDEWEB)

    Hall, Matthew R. [School of the Built Environment, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom)

    2007-01-15

    The SHU climatic simulation chamber is a novel piece of apparatus that allows testing of full-sized walls with realistic inner and outer wall climatic conditions. Four SRE test walls were successfully constructed and tested over four separate regimes to measure physical properties such as pressure-driven moisture ingress, rate of moisture penetration, and internal/interstitial condensation. The walls far exceeded a series of cyclic pressure-driven rainfall penetration tests based on BS 4315-2. After 5 days of exposure to static pressure-driven moisture ingress there was no evidence of moisture penetration or erosion. The embedded sensor array detected no significant increase in the relative humidity or liquid moisture content inside the test walls, throughout a range of temperature differentials with high levels of humidity, indicating a negligible risk of internal or interstitial condensation. (author)

  15. Current driven domain wall motion in rare-earth transition metal alloys with perpendicular magnetic anisotropy.

    Science.gov (United States)

    Li, Songtian; Liu, Xiaoxi; Morisako, Akimistu

    2012-09-01

    The domain wall movement behaviors under current combining with magnetic field in perpendicularly magnetized TbFeCo wire were studied by a polar magneto-optical Kerr effect microscope. The velocity for domain wall creeping along electrons flowing direction was found to be apparently higher than that of domain wall creeping against electrons flowing, which is the signature of the spin transfer torque effect. By employing the modified field-driven creep motion law, a spin transfer efficiency of 2.7 Oe cm2/10(6) A was determined for TbFeCo wire by treating the spin transfer torque as an effective field adding to the external field. The high spin transfer efficiency suggests that perpendicularly magnetized system with sharp domain walls in TbFeCo film shows high superiorities for applications in spin transfer torque based devices compared with in-plane magnetized systems.

  16. Study of the seismic performance of hybrid A-frame micropile/MSE (mechanically stabilized earth) wall

    Science.gov (United States)

    Chen, Yumin; Zhang, Zhichao; Liu, Hanlong

    2017-04-01

    The Hybrid A-Frame Micropile/MSE (mechanically stabilized earth) Wall suitable for mountain roadways is put forward in this study: a pair of vertical and inclined micropiles goes through the backfill region of a highway MSE Wall from the road surface and are then anchored into the foundation. The pile cap and grade beam are placed on the pile tops, and then a road barrier is connected to the grade beam by connecting pieces. The MSE wall's global stability, local stability and impact resistance of the road barrier can be enhanced simultaneously by this design. In order to validate the serviceability of the hybrid A-frame micropile/MSE wall and the reliability of the numerical method, scale model tests and a corresponding numerical simulation were conducted. Then, the seismic performance of the MSE walls before and after reinforcement with micropiles was studied comparatively through numerical methods. The results indicate that the hybrid A-frame micropile/MSE wall can effectively control earthquake-induced deformation, differential settlement at the road surface, bearing pressure on the bottom and acceleration by means of a rigid-soft combination of micropiles and MSE. The accumulated displacement under earthquakes with amplitude of 0.1‒0.5 g is reduced by 36.3%‒46.5%, and the acceleration amplification factor on the top of the wall is reduced by 13.4%, 15.7% and 19.3% based on 0.1, 0.3 and 0.5 g input earthquake loading, respectively. In addition, the earthquake-induced failure mode of the MSE wall in steep terrain is the sliding of the MSE region along the backslope, while the micropiles effectively control the sliding trend. The maximum earthquake-induced pile bending moment is in the interface between MSE and slope foundation, so it is necessary to strengthen the reinforcement of the pile body in the interface. Hence, it is proven that the hybrid A-frame micropile/MSE wall system has good seismic performance.

  17. Experimental Study of Cement Mortar-Steel Fiber Reinforced Rammed Earth Wall

    OpenAIRE

    Pang, Miao; Yang, Shuai; Zhang, Yongqiang

    2012-01-01

    Rammed earth construction is an ancient technique which has recently attracted renewed interest throughout the world. Although rammed earth is currently regarded as a promising material in the construction industry in the context of sustainable development, it is difficult to quantify its bearing capacity, mechanical performance, as well as retrofitting approach, which discourages people from large-scale application in architectural engineering. This paper is devoted to the study of these pro...

  18. Rammed earth walls in the late middle age castles in the actual province of Soria, Spain

    OpenAIRE

    Gil Crespo, Ignacio Javier

    2013-01-01

    This paper analyzed the building techniques based in the use of rammed earth in the Late Medieval fortifications in the province of Soria, Spain. The manorial castles of Serón de Nágima and Yanguas were built completely with rammed earth. However, these techinques are different. Through the study of the constructive signals, we can reconstruct the constructive process and made an hypothesis of the auxiliary scaffolding necessary for the construction. After, other four cases in which there is ...

  19. Study on passive earth pressure acting on the embedment of an earth retaining wall for braced excavation work in cohesive soil; Nenseido jiban ni okeru kussaku dodomeheki neirebu no judo doatsu ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, H. [Pacific Consultants K.K., Tokyo (Japan); Hirashima, K. [Yamanashi University, Yamanashi (Japan). Faculty of Engineering

    1995-12-15

    Passive earth pressure exerts a great influence on the stress and deformation of earth retaining walls in braced excavation. To calculate this pressure, conventional ultimate earth pressure equation, or Rankine-Resals and Coulomb`s equation, are currently applied respectively to cohesive and sandy soil. However, these intentional equation to determine passive earth pressure do not adequately take into account the excavation width during work and the shearing resistance on the earth retaining wall surface. This paper deals with cohesive soil only, deriving a calculation equation for passive earth pressure, which takes into account excavation width and the shearing resistance of the earth retaining wall surface. Then, constants in this equation are determined using the calculation results obtained from the finite element method with blasts-plastic elements. The calculation results are also compared with measured values in the model test in order to check the applicability of the calculation equation for passive earth pressure thus obtained. Finally, this paper proposes a practicable calculation equation for passive earth pressure. 13 refs., 10 figs., 10 tabs.

  20. Plant metabolism and cell wall formation in space (microgravity) and on Earth

    Science.gov (United States)

    Lewis, Norman G.

    1994-01-01

    Variations in cell wall chemistry provide vascular plants with the ability to withstand gravitational forces, as well as providing facile mechanisms for correctional responses to various gravitational stimuli, e.g., in reaction wood formation. A principal focus of our current research is to precisely and systematically dissect the essentially unknown mechanism(s) of vascular plant cell wall assembly, particularly with respect to formation of its phenolic constituents, i.e., lignins and suberins, and how gravity impacts upon these processes. Formation of these phenolic polymers is of particular interest, since it appears that elaboration of their biochemical pathways was essential for successful land adaptation. By extrapolation, we are also greatly intrigued as to how the microgravity environment impacts upon 'normal' cell wall assembly mechanisms/metabolism.

  1. wall

    Directory of Open Access Journals (Sweden)

    Irshad Kashif

    2016-01-01

    Full Text Available Maintaining indoor climatic conditions of buildings compatible with the occupant comfort by consuming minimum energy, especially in a tropical climate becomes a challenging problem for researchers. This paper aims to investigate this problem by evaluating the effect of different kind of Photovoltaic Trombe wall system (PV-TW on thermal comfort, energy consumption and CO2 emission. A detailed simulation model of a single room building integrated with PV-TW was modelled using TRNSYS software. Results show that 14-35% PMV index and 26-38% PPD index reduces as system shifted from SPV-TW to DGPV-TW as compared to normal buildings. Thermal comfort indexes (PMV and PPD lie in the recommended range of ASHARE for both DPV-TW and DGPV-TW except for the few months when RH%, solar radiation intensity and ambient temperature were high. Moreover PVTW system significantly reduces energy consumption and CO2 emission of the building and also 2-4.8 °C of temperature differences between indoor and outdoor climate of building was examined.

  2. Tabique walls composite earth-based material characterization in the Alto Douro wine region, Portugal

    Directory of Open Access Journals (Sweden)

    Rui CARDOSO

    2015-12-01

    Full Text Available The Alto Douro Wine Region, located in the northeast of Portugal, a UNESCO World Heritage Site, presents a relevant tabique building stock, a traditional vernacular building technology. A technology based on a timber framed structure filled with a composite earth-based material. Meanwhile, previous research works have revealed that, principally in rural areas, this Portuguese heritage is highly deteriorated and damaged because of the rareness of conservation and strengthening works, which is partly related to the non-engineered character of this technology and to the growing phenomenon of rural to urban migration. Those aspects associated with the lack of scientific studies related to this technology motivated the writing of this paper, whose main purpose is the physical and chemical characterization of the earth-based material applied in the tabique buildings of that region. Consequently, an experimental work was conducted and the results obtained allowed, among others, the proposal of a particle size distribution envelope in respect to this material. This information will provide the means to assess the suitability of a given earth-based material in regard to this technology. The knowledge from this study could be very useful for the development of future normative documents and as a reference for architects and engineers that work with earth to guide and regulate future conservation, rehabilitation or construction processes helping to preserve this fabulous legacy.

  3. Influence of rare earths on shrinkage porosity in thin walled ductile cast iron

    DEFF Research Database (Denmark)

    Pedersen, Karl Martin; Tiedje, Niels Skat

    2009-01-01

    Ductile cast iron has been cast in test bars with thickness from 2 to 10 mm. The rare earth elements La and Ce have been added to some of the castings to evaluate their influence on microstructure and shrinkage tendency. Both La and Ce increased the graphite nodule count, especially for thickness...... the temperature T-1, which is controlled by the growth of off-eutectic austenite dendrites, increased the shrinkage tendency....

  4. Dynamics of domain walls with lines in rare-earth orthoferrites in magnetic and electric fields with exchange relaxation processes taken into account

    Science.gov (United States)

    Ekomasov, E. G.

    2003-08-01

    The influence of exchange relaxation on the dynamics of domain walls with a "fine structure" in rare-earth orthoferrites in the presence of external magnetic and electric fields is investigated. A system of differential equations is obtained which describe the dynamics of a domain wall with a solitary line. The dependence of the steady-state velocity of the domain wall and line on the values of the relaxation parameters and on the components of the magnetic and electric fields is found. The results are compared with the known experimental results.

  5. The Role of Nonlocal Sediment Transport in Shaping Impact Crater Walls on Earth and Mars

    Science.gov (United States)

    Abbott, A. M.; Furbish, D. J.

    2013-12-01

    With increasing interest in the concept of ';nonlocal' sediment transport on steep, regolith covered hillslopes, clearer connections between theoretical formulations of nonlocal transport and natural landforms are needed. Scree slopes that form within impact craters provide useful, interesting study sites, due in part to their reasonably well-known initial morphologies. Recent research also suggests that the surface of Mars may be more erosionally active than previously thought. By using elevations derived from LiDAR data for Earth and HiRISE images for Mars together with a probabilistic description of nonlocal transport that includes entrainment and disentrainment rates, comparisons are made between Barringer Meteorite Crater in Arizona and Martian craters of various ages. This enables commentary on whether nonlocal transport produces similar slopes, despite the differing transport processes and acceleration due to gravity for the two planets. Physical insight is obtained through laboratory experiments where gravel particles are dropped on a loose granular slope composed of similar sized gravel inclined at different slopes, including the angle of repose and a flat layer of gravel. Total travel distances were obtained for approximately 500 particles dropped from three different heights for each slope angle. The resulting distributions of travel distances are exponential-like, but for steeper slopes these distributions may decay less rapidly than an exponential function, indicating a decreasing likelihood of disentrainment with increasing travel distance. These approximately dynamically scaled experiments will help clarify the relationship between drop height, slope, surface roughness, and mean travel distance. A description of the disentrainment rate based partly on these findings will to be incorporated in a numerical model that simulates impact crater erosion for Earth and Mars. This will test the theoretical similarity of two locations that are physically very

  6. ANALYSIS AND DESIGN OF REINFORCED EARTH WALL FOR SHORE PROTECTION SYSTEM AGAINST TSUNAMI

    Directory of Open Access Journals (Sweden)

    Amit Srivastava

    2009-01-01

    Full Text Available The evaluation and design of coastal shore protection works for tsunamis assumed considerable importance following the impact of the 26th December 2004 tsunami in India and other countries of Asia. The lack of proper guidelines made matters worse and resulted in the great damage that occurred. Subsequent surveys indicated that scour resulting from high water velocities was one of the prime reasons in the damage of simple structures. In some cases, it became apparent that sea walls were helpful in minimizing the degree of damage. The objective of the present study is to illustrate how proper design analysis for expected wave heights as well as the use of flexible systems such as geocells, are likely to provide better shoreline protection. Protective systems can be designed that can withstand wave forces that correspond to a variety of incidence probabilities. The present study illustrates such an analytical design approach that is necessary for a shoreline protection system and provides references to relevant wave height data for the east coast of India.

  7. Earth

    CERN Document Server

    Carter, Jason

    2017-01-01

    This curriculum-based, easy-to-follow book teaches young readers about Earth as one of the eight planets in our solar system in astronomical terms. With accessible text, it provides the fundamental information any student needs to begin their studies in astronomy, such as how Earth spins and revolves around the Sun, why it's uniquely suitable for life, its physical features, atmosphere, biosphere, moon, its past, future, and more. To enhance the learning experience, many of the images come directly from NASA. This straightforward title offers the fundamental information any student needs to sp

  8. Active earth pressure on retaining walls in non-limit state%挡土墙非极限状态主动土压力分布

    Institute of Scientific and Technical Information of China (English)

    张永兴; 陈林

    2011-01-01

    The Coulomb's limit equilibrium theory is modified to study the active earth pressure on retaining walls in non-limit state. It is considered that the earth pressure on a retaining wall is due to the thrust of a sliding wedge of soil between the back of the wall and a plane which passes through the bottom edge of the wall. The basic equations are formulated by considering the equilibrium of the forces on a thin-layer element of the wedge. By using the equilibrium equations of the moments on the entire wedge, the lateral coefficient of earth pressure, the earth pressure distribution along the wall back, the resultant force of earth pressure and its action point are obtained. The effects of the internal frictional angle of the backfill, the frictional angle between the wall and the backfill and the displacement ratio of the wall on the lateral coefficient of earth pressure, the earth pressure, the resultant force of earth pressure and its action point,and the overturning stability of the retaining wall are investigated. The proposed method is compared with experimental data. Evaluation of the influence of the displacement ratio of the wall on the overturning moment indicates that if they are designed according to the limit equilibrium theory, it would be dangerous for the overturning stability of the retaining wall with an active translational movement in non-limit state.%改进库仑极限平衡理论,用于非极限状态主动土压力的研究,认为挡土墙土压力是由墙后填土在平衡状态下出现的滑动楔体所产生.在该滑动楔体上沿竖向取水平薄层作为微分单元体,通过作用在单元体上力的平衡条件,建立挡土墙非极限状态主动土压力基本方程,并结合整个滑楔体的力矩平衡条件,由此得到对应不同内摩擦角、墙土摩擦角和挡土墙位移比的侧土压力系数,将其用于水平微分单元法求解刚性挡土墙平移模式下非极限状态主动土压力,得到挡土墙土压

  9. Seismic active earth pressure of retaining wall%地震作用下挡土墙主动土压力分布

    Institute of Scientific and Technical Information of China (English)

    张永兴; 陈林

    2012-01-01

    The basic analysis equations were set up by considering the equilibrium of the forces on a thin-layer element of the wedge. By using the equilibrium equation of the moments on the whole wedge, the lateral coefficient of earth pressure, and the earth pressure distribution along the wall were obtained. The effects of seismic coefficient on the lateral coefficient of earth pressure and the distribution of earth pressures were investigated. The results show that the lateral earth pressure coefficient increases as the horizontal seismic coefficient increases. The effect of the vertical seismic coefficient is more complicated. If the vertical seismic coefficient is less than zero, the lateral earth pressure coefficient decreases as the vertical seismic coefficient increases; If the vertical seismic coefficient is greater than zero, the lateral earth pressure coefficient increases as the vertical seismic coefficient increases; the maximum earth pressure gradually decreases as the vertical seismic coefficient increases. The maximum earth pressure first decreases and then increases as the horizontal seismic coefficient increases; as the increase of the vertical and horizontal seismic coefficient increases, the position of the maximum lateral seismic earth pressure moves gradually to the top of the wall, but near the bottom of the wall, the relative value of the earth pressure decreases, and near the top of the wall, the relative value of the earth pressure increases. Theproposed method was verified by some experiment data. The calculated resultant and maximum earth pressure agree well with the experiment results. The effect of seismic coefficient on the points of application of the resultant earth pressure was investigated. The proposed method was compared with the Mononobe-Okabe's theory. The results indicate that it is dangerous for the overturning stability of retaining walls with the translational movement mode if they are designed according to the Mononobe

  10. Materials and structures of rammed earth walls of Ming great wall-with Datong town section as example%明代夯土长城的城墙材料与构造--以大同镇段为例

    Institute of Scientific and Technical Information of China (English)

    沈旸; 周小棣; 常军富

    2014-01-01

    As the typical rammed earth Great Wall remains,the Ming great wall of Datong town was taken as an example for better understanding the material and structural characteristics of rammed earth walls.On the basis of field work,the theory and methods of soil mechanics was used for refer-ence to finish the classified statistics of types and existing methods of rammed earth materials.Struc-tural characteristics of the rammed earth walls were analyzed from aspects of foundation,rammed layer thickness,rammed layer structure and laying twigs,which revealed that the varied materials and internal structures of the rammed earth Great Wall were closely related with the environment. The results show that the Ming Great Wall of Datong Town is generally of a height of 6 to 10 m, with a slope of 70°to 80°,and the rammed layer thickness of 150 to 250 mm.The materials of rammed earth walls consist of fine-grained soil,gravel,crushed stone,block stone and twigs.The content of gravel,crushed stone and block stone is closely related with the soil environments and ter-rain,which proves that the materials were drawn from nearby.Various rammed layer structures of the soil with paving or doped gravel,crushed stone and block stone reflect that the ancients improved the structures based on practical experience and soil environment.The phenomenon of laid twigs used as the connecting tendons was shown in several cases,which reflects the technological achieve-ments made by the ancients on rammed earth.%为了深入了解夯土长城的材料和构造特征,在对现存明大同镇段长城这一典型夯土长城遗存进行实地考察的基础上,借鉴土力学的相关理论和方法,对城墙夯土材料的种类和存在方式进行了分类统计,并从基础做法、夯层厚度、夯层构造和铺设植物枝条做法等方面分析了城墙的构造特征,揭示出夯土长城在材料和构造方面的丰富性以及与环境的密切相关性。

  11. 现代夯土墙体施工技术研究与实践%Research and Application of Modern Rammed Earth Wall Construction Technology

    Institute of Scientific and Technical Information of China (English)

    周铁钢; 彭道强; 穆钧; Hugo Charly Gasnier; Quentin Arya Romain Chansavang

    2012-01-01

    Traditional rammed earth walls were members that were rammed from raw earth layer by layer using tools such as pestle or hammer etc. With modern construction technology, rammed earth materials, ramming equipment and ramming technology can all be improved to enhance the safety and durability of rammed earth buildings. Under guidance of the International centre for research and application of earth construction, and with the engineering practice of some pilot projects, this, article highlighted the selection and mixing of raw earth materials and improvement of ramming technology.%传统夯土建筑是指以木制或石制杵、锤等工具,将原状土质材料逐层夯实形成承重墙体的建筑.现代夯土建筑技术对传统夯土建筑中夯筑材料、夯筑机具、夯筑工艺等方面进行了改良,以提高夯土房屋的安全性与耐久性.在国际生土建筑研究和应用中心的指导下,结合试点工程的研究与实践,重点对如何科学选择、配置夯土材料及墙体夯筑工艺的改良情况做了说明.

  12. 非极限状态挡土墙主动土压力研究%Active earth pressure on retaining wall under non-limit state

    Institute of Scientific and Technical Information of China (English)

    胡俊强; 张永兴; 陈林; 陈建功

    2013-01-01

    The thin layer element method is used to study the active earth pressure under non-limit state. It is considered that the earth pressure against the back of a retaining wall is due to the thrust exerted by a sliding wedge of the soil between the back of the wall and a plane which passes through the bottom edge of the wall. The basic equations are proposed by considering the equilibrium of the forces and moments on a thin-layer element of the wedge. By using the equilibrium equations, the coefficients of earth pressure, the unit earth pressure, the resultant force of earth pressure and the acting point of the resultant force are obtained. The effects of the internal frictional angle of backfill, the frictional angle between the wall and the backfill and the displacement ratio of the wall on the lateral coefficient of earth pressure, the earth pressure, the resultant force of earth pressure, the acting point of the resultant force are investigated. The discussions indicate that if they are designed according to the limit equilibrium theory, it will be dangerous for the overturning stability of retaining walls with the active translational movement mode under non-limit state. Moreover, the distributions of the active earth pressure computed by the deduced formula agree with the measured data of the engineering case well.%利用薄层单元法对挡土墙非极限状态主动土压力进行研究,认为挡土墙土压力是由墙后填土在平衡状态下出现的楔形土体产生,取挡土墙后楔形土体沿平行于填料坡面的薄层作为微分单元体,通过作用在微分单元体的力和力矩平衡条件,建立挡土墙非极限状态主动土压力微分方程,得到非极限状态土侧压力系数、土压力强度、土压力合力和作用点的理论公式.根据非极限状态摩擦角与墙体位移关系,分析填土内摩擦角、墙土摩擦角和挡土墙位移比对土侧压力系数、土压力分布、土压力系数和作用点的影

  13. Experimental Study on Seismic Performance of Bamboo Net Strengthened Earth Walls%竹条网加固夯土墙抗震性能试验研究

    Institute of Scientific and Technical Information of China (English)

    李梁峰

    2015-01-01

    福建土楼等夯土古建筑由于受环境长期侵蚀和旅游开发的影响已遭到严重破坏,迫切需要进行抗震加固。针对现有夯土结构抗震加固方法的不足,提出了用竹条网对夯土墙进行抗震加固的新方法。在此基础上制作8片夯土试验墙,并对其进行水平单调荷载和往复荷载试验,研究了竹条用量、竖向荷载及承压装置等对加固效果的影响。研究结果表明:竹条网加固法能够有效提高夯土墙的抗震性能,其加固效果随加固竹条量的增加而显著增加。水平承载力及变形能力受竖向荷载影响较大,随着竖向压力的增加,墙体的水平承载力有较大增长,而变形能力有所降低。使用竹衬管作为承压装置可以有效提高其承载能力与延性。竹条网加固法在夯土古建筑抗震加固中具有较广阔的应用前景。%Due to the long-term erosion of the environment and the influence of tourism development ,Fujian Tulou and other historical structures built with rammed earth have been seriously damaged .There is an urgent need for seismic rein-forcement of these buildings .To overcome the disadvantages of the existing seismic reinforcement methods for rammed earth structures ,a new method using bamboo net was proposed .With this method ,8 test walls with rammed earth were constructed .And then the horizontal monotonic loading tests and cyclic loading tests were conducted to investigate the ef -fect of the amount of bamboo splints ,vertical loading and the stress dispersing device on the reinforcement of the test walls .The results indicate that the strengthening method with bamboo net can effectively improve the seismic performance of rammed earth walls ,which enhances with the increase of the amount of bamboo splints in the net .The horizontal bear-ing capacity and deformation capacity are greatly influenced by the vertical load ,with the increase of the vertical load the horizontal

  14. 包裹式加筋土挡土墙抗震试验分析%Seismic Tests and Analysis of Warped Reinforced Earth-retaining Wall

    Institute of Scientific and Technical Information of China (English)

    李庆海; 王炳锟; 蒋楚生; 段忠臣

    2012-01-01

    Research purposes: According to the engineering features of the Xiangyun Station of Guangtong-Dali Railway, the research was done on the reinforcing mechanism, load bearing, deformation, design methods, computing theory and the failure mode of the wraped reinforced earth-retaining wall under earthquake effect to improve the computing theory and numerical simulation method for the seismic design of the reinforced earth-retaining wall and promote the application of reinforced earth-retaining wall in engineering. Research conclusions; The warped reinforced earth-retaining wall is better than the ordinary earth-retaining wall in seismic property because the wrapped effect can make seismic wave weak during the propagation and amplification of the seismic wave along the wall up. When in 0. 4 g and 0. 616 g , the model produced the evident seismic fall, and cracks happened in the junctions between the wall panel and the reinforced soil and between the reinforced soil and the unreinforced soil. In the peak acceleration, the potential fracture surface of these two kinds of experimental models were distributed in the same position, approximate to 0.45 H vertical line. But in the "Code for Design of Retaining Structure of Railway Subgrade" (TB 10025-2006) , the potential fracture surface is approximate to 0.3 H vertical line and it slants to unsafety. So the reinforcing length should be increased in design. From the theoretical calculation and the analysis results of the internal and external stability of the reinforced earth-retaining wall obtained by the test data calculation, it was seen the coefficient of sliding resistance, the coefficient of capsizing resistance, the coefficient of uplifting resistance of the whole wall and the coefficient of uplifting resistance of the geogrid in various layers obtained by theoretical calculation were larger than the test data calculation. This showed the current code was unsafe and could be properly modified.%研究目的:针对广

  15. Multi-walled carbon nanotube-based ternary rare earth (Eu3+, Tb3+) hybrid materials with organically modified silica-oxygen bridge.

    Science.gov (United States)

    Li, Qiu-Ping; Yan, Bing

    2012-08-15

    A series of ternary rare earth (Eu(3+), Tb(3+)) complexes are covalently coated to the 3-aminopropyltriethoxysilane functionalized multi-walled carbon nanotube (MWCNT) by a simple in situ sol-gel method by the bifunctional silylated monomer TTA-Si and TAA-Si (TTA-Si and TAA-Si are 3-(triethoxysilyl)propylisocyanate (TEPIC) modified thenoyltrifluoroacetone (TTA) and trifluoroacetylacetone (TAA), respectively). The resulting materials are characterized by Fourier transform infrared spectra, scanning electronic microscope, transmission electron microscope, thermogravimetric analysis, ultraviolet visible diffused reflection measure, photoluminescence spectra, and X-ray diffraction. The photoluminesce measurements indicated that these hybrids exhibit characteristic red and green luminescence originating from the corresponding ternary rare earth ion (Eu(3+), Tb(3+)). The luminescence quenching effect of MWCNT networks have been successfully restrained by coating a relatively thicker silica-oxygen-based organic-inorganic complex. Furthermore, the fluorescence lifetimes and emission quantum efficiencies of Eu(3+) hybrid materials are also determined. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. 挡土墙被动土压力的滑移线解%Slip-line solution to passive earth pressure on retaining walls

    Institute of Scientific and Technical Information of China (English)

    彭明祥

    2011-01-01

    Based on the limit equilibrium theory, the backfill is treated as a perfectly elastic-plastic material which follows the Mohr-Coulomb yield criterion, and is assumed to be an isotropic, homogeneous and incompressible (or non-expansive) perfectly continuous medium.The stress singularity and its stress boundary condition are introduced, and' a statically determinate and solvable mathematical model for the limit equilibrium boundary value problem is established without considering the stress-strain relationship.Then the slip-line field and stress field in plastic zone of the backfill are solved by use of the slip-line method, furthermore, the passive earth pressure on retaining walls and the reaction on slip surfaces are derived.Geometric and mechanical similarity principle is presented by means of dimensionless analysis.The results show that the slip-line solution to the passive earth pressure is generally less than or equal to the Coulomb's solution, and the classical Rankine's earth pressure or the classical Coulomb's earth pressure satisfying non-singularity condition is in accordance with the slip-line solution, and the Hencky's first theorem and second theorem are not generally applicable.%基于极限平衡理论,视墙后填土为服从Mohr-Coulomb屈服准则的理想弹塑性材料,并且假定它是各向同性的、均匀的以及不可压缩(膨胀)的理想连续介质.引进了应力奇点及其应力边界条件,建立了静定可解的极限平衡边值问题数学模型,而不必考虑土的应力-应变关系,采用滑移线法求解了墙后塑性区的滑移线场和应力场,进而求解了挡土墙被动土压力和滑裂面土反力.通过无量纲分析,提出了几何力学相似原理.数值分析表明,被动土压力的滑移线解一般总是小于或等于库仑解,经典朗肯土压力或满足非奇异条件的经典库仑土压力与滑移线解一致,Hencky第一定理和第二定理不具有普遍适用性.

  17. RESEARCH ON ACTIVE EARTH PRESSURE BEHIND RIGID RETAINING WALL FROM CLAYEY BACKFILL CONSIDERING SOIL ARCHING EFFECTS%考虑土拱效应的黏性填土挡土墙主动土压力研究

    Institute of Scientific and Technical Information of China (English)

    涂兵雄; 贾金青

    2012-01-01

    Analytical expressions for the active earth pressure ratio and active earth pressure are derived, against on a rigid retaining wall from clayey backfill undergoing horizontal translation) considering the soil arching effects and the influence of soil-wall friction angle, wall adhesion and cohesion of backfill. The results show that the active earth pressure ratio and active earth pressure are related to soil-wall friction angle, depth of the point and the internal friction angle, cohesion, unit weight of the backfill. The theoretical comparisons between the analytical expressions proposed for active earth pressure ratio and active earth pressure and the existing classical theory, the previous research results show great agreement with each other, so as to verity the correctness of the results in this paper.%以墙后填土为黏性土的刚性挡土墙为研究对象,考虑挡土墙后的土拱效应,以及墙土摩擦角、墙土黏结力、墙后填土黏聚力的影响,推导挡土墙在平动模式下的主动土压力系数和主动土压力解析解.结果表明,考虑土拱效应的主动土压力系数和主动土压力均与墙土摩擦角、计算点深度以及墙后填土的内摩擦角、黏聚力及重度有关.通过将求解的主动土压力系数和主动土压力与现有经典理论解及前人理论研究成果对比,发现结果完全吻合,验证该研究结果的正确性.

  18. Rainfall of the Rammed Earth Wall of Square Earth Buildings Caused by the Wind-Driven Rain%方形土楼夯土墙的风驱雨量分布

    Institute of Scientific and Technical Information of China (English)

    梁兰娣; 彭兴黔; 花长城

    2013-01-01

    The wind tunnel experiment of square earth buildings was tested,and calculation model of rainfall process was introduced when wind Fields of numerical simulation was well consistent with the test wind field.The distribution characteristics of wind-driven rainfall of earth buildings' windward surface for different wind speeds,different rainfalls and different cantilever spans of eaves was discussed by this method.The results show that the erosion factor η of wind-driven rain is related to the wind speed and rainfall,and η increases with the increase of the wind speed and rainfall; the cantilevered roof forms shelter effectively the wall surface near the roof.%对方形土楼进行风洞试验和数值模拟,在数值模拟风场和试验风场达到较好一致性时引入降雨过程的计算模型.采用该方法研究方形土楼在不同风速、不同降雨量,以及不同屋檐悬挑长度下迎风墙面风驱雨量的分布特征.研究结果表明:风驱雨侵蚀因子与风速和降雨量有关,并随风速及雨强的增加而增加;悬挑屋盖对屋盖附近区域的墙面形成有效的遮蔽作用.

  19. 土坯及其构件承载力的可靠度分析%Reliability Analysis of Earth Architecture Bearing Wall

    Institute of Scientific and Technical Information of China (English)

    曹耿; 阿肯江·托呼提; 赵成; 丁广林

    2011-01-01

    可靠度分析是对结构安全评估的一种科学方法,将可靠度理论运用到生土建筑设计,是对生土建筑结构安全评估的有效方法.通过承受竖向静载作用下墙体的功能函数、假设函数中随机变量的分布、假设检验后用验算点法求出可靠指标,分析了影响可靠指标的主要因素,得到了满足可靠指标要求的土坯最低强度标准值.%Reliability analysis is a scientific method for evaluation of structure security. It is an effective method to earth structure. Assuming the performance function of vertical loaded bearing wall and distribution of random variable, after hypothesis testing the reliability index 0 is obtained by JC method. The main influential factors of β are analyzed, adobe's strength nominal value and problem to be solved further are proposed.

  20. 考虑土拱效应的铁路刚性挡墙主动土压力计算方法%Calculation Method of Active Earth Pressure of Railway Rigid Retaining Wall Considering Soil Arch Effect

    Institute of Scientific and Technical Information of China (English)

    路维; 孙文君; 王学民; 杨鹏志; 崔立功

    2016-01-01

    对考虑土拱效应的水平微元滑裂体水平向及竖向静力平衡方程进行了分析,获得了平移模式下的刚性挡土墙侧向主动土压力、主动土压力合力及其作用点的计算公式,并与模型试验数据进行了比较.结果表明:本文得到的平移模式下刚性挡土墙墙后主动土压力分布与模型试验结果吻合较好,最大值比实测值略大;墙背主动土压力沿墙高呈非线性分布,墙背主动土压力合力作用点高度大于墙高的1/3.%This paper analyses the horizontal and vertical static equilibrium equations of horizontal differential sliding mass with soil arch. New formulas of rigid retaining wall lateral active earth pressure,active earth pressure resultant force and its action position were derived under translation mode. The Comparisons between the theoretical and measured values shown that the lateral active earth pressure distribution of rigid retaining wall under translation mode from the proposed formulas are agree well with results from the model test,and the maximum value from calculation is slightly larger than measured value. The distribution of the lateral active earth pressure is nonlinear along the wall height,and the action position of active earth pressure is larger than one third of the wall height.

  1. 考虑土拱效应的非垂直挡墙地震主动土压力%SEISMIC ACTIVE EARTH PRESSURE FOR NON-VERTICAL RIGID RETAINING WALL CONSIDERING SOIL ARCHING EFFECT

    Institute of Scientific and Technical Information of China (English)

    周亦涛; 陈福全

    2015-01-01

    The stresses on the wall and sliding plane of the sliding backfill mass at arbitrary depths were obtained according to the soil arching effect. A formula of the seismic active failure angle behind the non-vertical rigid retaining wall under translation mode was obtained on the basis of the pseudo-static method and the equilibrium total forces. A formula of the seismic active earth pressure against the non-vertical rigid retaining wall under translation mode was derived according to the method of differential level layer. The seismic active earth force and the action point were obtained. The distribution of seismic active earth pressure from the proposed formula was non-linear along the height of wall. In addition,the influences of the wall-back inclination,internal friction angle of backfill,wall-soil friction angle,seismic coefficient and load against the backfill surface on the seismic failure angle,seismic active earth pressure and its coefficient,seismic active earth force and height of its application were investigated.%由土拱效应原理得到滑裂土体的墙面和滑裂面上的应力,然后根据拟静力法和滑裂土体的整体受力平衡,得到平移模式下非垂直刚性挡土墙的地震主动破裂角计算式.进一步根据水平层分法获得墙背地震主动土压力及其系数、地震主动土压力合力及其作用点高度等的计算式.此外,分别讨论墙背倾角、填土内摩擦角、墙土摩擦角、地震系数和填土表面荷载等对地震主动破裂角、法向地震主动土压力分析、地震主动土压力合力系数、地震主动土压力合力及其作用点相对高度等的影响.

  2. 竹筋夯土墙单调水平荷载非线性有限元分析%Nonlinear FEM analysis of rammed-earth walls with bamboo bars under monotonic horizontal load

    Institute of Scientific and Technical Information of China (English)

    文枚; 李洪昌; 李岩

    2011-01-01

    Numerical models of rammed-earth walls with bamboo bars under monotonic horizontal load were builded using Solid 65 and Link 8 in the commerical finite element software ANSYS, and then analyzed, lateral resistence capacities, crack shapes, loaddisplacement curves and ductilities of the rammed-earth walls with bamboo bans were reached.By means of comparing the analytical to experimental results,it can be concluded that analysis of rammed-earth walls with bamboo bars using FEM has a high precision.%应用有限元分析软件ANSYS中的Solid65和Link8单元建立竹筋夯土墙的数值分析模型,并对其进行单调荷载下的数值计算,得出了竹筋夯土墙的抗侧承载力、裂缝形态、荷载位移曲线和延性.将数值结果与试验结果进行对比,结果表明,有限元法分析竹筋夯土墙具有较高的精度.

  3. 考虑土拱效应的刚性挡墙主动土压力分析%Analysis of active earth pressure on rigid retaining walls considering soil arching

    Institute of Scientific and Technical Information of China (English)

    王杰; 夏唐代; 贺鹏飞; 黄博

    2014-01-01

    以墙后填土为无黏性土的刚性挡土墙为研究对象,考虑墙后土体的土拱效应,修改了 Shubhra Geol 抛物线形土拱表达式,推导了对应不同内摩擦角和墙-土摩擦角的挡土墙平动模式下的主动土压力系数。基于水平微分单元法,得到考虑土拱效应的主动土压力分布、合力大小和合力作用点高度的理论表达式,并与现有经典理论解及前人理论研究成果和模型试验数据进行对比分析,结果表明,主动土压力与墙-土接触面摩擦角、土体内摩擦角、土体重度和挡墙高度相关,土压力分布为非线性,与其他结果比较吻合,从而验证了该研究成果的正确性。%Taking a rigid retaining wall with cohesionless backfill for example, considering the soil arching, the active earth pressure factor is derived for retaining wall under translation mode with different internal friction angles and wall-soil friction angles. The Shubhra Geol parabolic soil arching expression is modified. Based on horizontal differential element method, new formulations are proposed for calculating the active earth pressure, the resultant earth pressure and its action point. In order to check the accuracy of the proposed formulation, the predictions from the equation are compared with the results of full-scale test and existing classical theory. The results show that the active earth pressure is related to wall-soil friction angle, the internal friction angle, the unit weight of backfill and the height of retaining wall. It is shown that the earth pressure is nonlinear and the previous research results show great agreement with each other;and the correctness of the results is verified.

  4. Earth retaining system by means of cylindrical slurry wall of high strength and high flowability concrete; Kokyodo / koryudo concrete wo mochiita enkei haku gata renzoku chichu heki ni yoru yamadome

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, M.; Tsutsumi, Y. [Tokyo Gas Co. Ltd. (Japan); Moriya, M. [Taisei Construction Co. Ltd., Tokyo (Japan)

    1997-10-01

    A LPG underground tank (60,000 cu.m, 48m in dia.) was constructed at Tsurumi ward of Yokohama city by Tokyo Gas Ltd. In advance of evacuation work, RC elements which have the highest strength in Japan were applied as connected wall for earth self-retaining. One stage of the wall (1.0m in thickness) was composed of 28 elements. In order to prevent the lifting force by the underground water against the tank bottom (design level (DL) is -32.8m), amount of permeable water from outside must be as small as possible. Owing to driving the wall into the soft bedrock by 10m, the lower end of the wall came to be DL-66m. For the purpose of estimation of permeabilities of the clay layer and the soft bedrock, simulation applying the non-stationary effective stress analysis was carried out at the time of inside draining and of excavation at intervals of 8m. Results of simulation showed that the permeabilities of the connected wall and the soft bedrock belonged to the smallest class. It is considered that the satisfactory achievement has been obtained because actual amount of gushing water has been almost constant at 6 cu.m/day. 4 refs., 8 figs., 6 tabs.

  5. A STUDY ON IMPROVED PROTOTYPE OF REINFORCED EARTH RETAINING WALL MATRIX RAID%加筋土挡土墙工作机理改进原型试验研究

    Institute of Scientific and Technical Information of China (English)

    于庆峰; 赵含章

    2011-01-01

    在前人研究的基础上,对加筋土挡土墙试验原型进行了改进.以不同超载下墙面板的土压力、墙面板的位移、拉筋的拉力等变化过程为依据,对加筋土挡土墙的工作机理进行了探索.测试结果分析表明:加筋土挡土墙通过发生一定的侧向位移使拉筋发挥作用;墙面板所受的土压力随着竖向土压力的变化而变化,呈现先增大再减小的过程;拉筋对土体的侧限作用发挥到一定程度后,墙面板的土压力将要开始随着拉筋内力的增大而减小;拉筋的内力越大,拉筋对土体的侧限作用发挥越充分,墙面板的位移增加越缓慢.%On the basis of previous studies, Earth Retaining Wall Testing Prototype was improved. According to the transformation process of different earth pressure of an overloaded Shingle nail, displacement of a Shingle nail and the tension of Lacing Wire, the Matrix Raid of Reinforced Earth Retaining Wall is explored. The analysis of the testing results shows: Reinforced Earth Retaining Wall enables lacing wire to work by a certain lateral displacement. Earth pressure of Shingle nails changes with the shift of Vertical earth pressure , showing a process of increasing firstly and decreased then. When the Lateral Restraint Function of Lacing Wire goes to a certain extent, the earth pressure of the Shingle nail will decrease with the increase of internal force of Lacing Wire . The stronger the internal force of Lacing Wire is, the fuller the Lateral Restraint Function of Lacing Wire is, and the slower the replacement of the Shingle nail is.

  6. A METHOD FOR CALCULATING UNLIMITED EARTH PRESSURE OF RETAINING WALL WITH TRANSLATION MODE%平移模式下挡墙非极限土压力计算方法

    Institute of Scientific and Technical Information of China (English)

    杨庆光; 刘杰; 何杰; 罗善煌

    2012-01-01

    在考虑挡墙平动位移效应和内摩擦角折减系数的基础上,利用薄层斜条分法,提出墙后填土为无黏性土时挡墙非极限主动和被动土压力计算公式.为验证该方法的可行性,对平移模式下挡墙进行主动和被动土压力模型试验,并利用该方法对2个模型试验进行计算分析.试验及计算结果均表明:不同s/sc比值情况下,主动土压力随深度增加表现出先增大后减小的趋势,且在0.6H(H为挡土墙高度)位置与库仑土压力曲线出现交点;被动土压力沿深度非线性增大,但其值均小于库仑被动土压力值;主动土压力合力作用点位置均高于库仑土压力合力作用点,而被动土压力合力作用点位置均低于库伦土压力合力作用点,并且随着s/sc比值的提高差距越大.%Considering the movement effect of translation mode, the friction angle reduction coefficient and the method of bevel-layer analysis, a method for calculating the unlimited active and passive earth pressures is deduced for cohesiveless soil retaining wall with translation mode. In order to validate the feasibility of the proposed approach, two model tests for active and passive earth pressures were conducted in laboratory, respectively; and the proposed method was used to analyze the two models. Experimental and theoretical results indicate that the curve of active earth pressure increases firstly and decreases then along the depth of retaining wall with different values of s/sc, and it has a point of intersection with the curve of Coulomb active earth pressure at the depth of 0.6H, where H is the wall height. The passive earth pressure keeps increasing along the depth of retaining wall and is always smaller than the Coulomb passive earth pressure. Further study indicates that the action point position of the active earth pressure is higher than that of the Coulomb passive earth pressure, and the action point position of the passive earth pressure is lower

  7. Seismic test of rammed earth wall and reconstruction of demonstrate residence after Panzhihua earthquake%灾后重建中夯土墙民居现场抗震试验研究与实践

    Institute of Scientific and Technical Information of China (English)

    周铁钢; 宋崇阳

    2012-01-01

    The direct shear test on rammed earth specimens and monotonic loading test on rammed earth walls which structure is used in the country are studied. The shear strength and failure mode are analsed and shear-bearing formula of rammed earth walls is advised, which lays a theoretical foundation for the seismic calculation method. In the course of experimental research, seismic structure and construction technology of local rammed earth buildings were designed and improved. Meanwhile, 33 households constructed new rammed earth residence under guidance,which played an exemplary role to the adjacent regions.%对西南山区使用较广泛的夯土墙进行了现场墙片抗剪性能试验与土样直接剪切试验,研究夯土墙体在单调荷载作用下的夯土墙承载力指标和破坏形态,并对夯土墙抗剪承载力的主要影响因素进行了探讨,提出夯土墙抗剪强度计算的建议公式.在试验研究的基础上,对当地典型夯土墙结构农房进行了抗震设计及施工工艺改良,并且指导建造了33户新型夯土墙农房,起到了很好的示范作用.

  8. 甘肃武都典型夯土民房承重墙体抗剪强度试验研究%Experimental Study on Shearing Strength of Typical Rammed Earth Wall in Wudu Area, Gansu Province

    Institute of Scientific and Technical Information of China (English)

    徐舜华; 王兰民; 王强; 袁中夏

    2011-01-01

    Wudu is the area where using typical rammed earth rural houses in Gansu province. In experiments two wall specimens are built using local material and local construction technology, and the shearing strength of wall is investegated by pseudo-static test, the results show(l) the overlying load on the wall has greater effect on horizontal load capacity and deformation of the wall, with the overlying load from 10 kN to 18 kN, cracking load and ultimate load increased by 217% and 359%, ultimate top displacement is reduced by 30%; (2) the rammed earth wall is always destroyed along the horizontal and vertical contacts between layers, and eventually is fragmented into blocks with the role of horizontal cyclic loading. At last, this paper recommend to reinforce the rammed earth bearing wall of the existing rural houses with iron mesh.%武都是甘肃省典型夯土民房使用地区.试验中使用武都当地常用土料,完全按照当地施工工艺夯筑两片夯土墙体试件,利用伪静力方法研究墙体抗剪强度.结果显示:(1)上覆荷载对夯土墙体的水平承载力和变形影响较大,随着上覆荷载从10 kN增加到18 kN,开裂荷载和极限荷载分别增加了217%和359%,极限顶点位移则降低了30%;(2)在水平往复荷载的作用下,夯土墙体始终沿着夯土层间水平和垂直接触裂缝处产生破坏,最终碎裂成块体.最后提出了使用铁丝网来加固现存夯土民房承重墙体的建议.

  9. The Stress Deformation Analysis of an Earth-Rockfill Dam Body Concrete Impervious Wall%土石坝坝体混凝土防渗墙应力变形分析

    Institute of Scientific and Technical Information of China (English)

    牛坤

    2014-01-01

    The study of the impervious concrete wall body stress deformation characteristics of an earth -rockfill dam under different plastic modulus , wall thickness and dam height working conditions gives a reference to design of a similar hydraulic project .Taking the optimized design of the impervious wall reinforcement scheme of the dan-ger-removing and reinforcement project of a certain clay core dam in Zhejiang Province as the basis , the stress de-formation characteristics of the impervious wall were analyzed by means of 2-dimensional nonlinearity .The wall body stress is significantly affected by plastic modulus and dam height and less affected by wall thickness , while its horizontal displacement is significantly affected by dam height and very little by either plastic modulus or wall thick -ness.When a dam impervious wall is designed , importance should be attached to selection of wall body concrete plastic modulus.In general ordinary concrete could be used for the low dams with a height of 20m or less, and the plastic modulus should be controlled to be ess than 5,000 MPa for the 40 –60m high dams.%以浙江省某粘土心墙坝除险加固工程防渗墙加固方案优化设计为背景,采用二维非线性对防渗墙的应力变形特性进行分析。研究土石坝坝体混凝土防渗墙在不同弹性模量、墙厚和坝高工况下的墙体应力变形特性。墙体应力受弹性模量及坝高的影响显著,受墙厚的影响微小;水平位移受坝高的影响显著,受弹性模量和墙厚的影响很小。坝体防渗墙设计时,应重视墙体混凝土弹性模量的选择。对一般20 m级的低坝可采用普通混凝土材料,对于40~60 m级中坝,应控制弹性模量不超过5000 MPa。

  10. Active Earth Pressure for Non﹣vertical Rigid Retaining Wall Considering Soil Arching Effect%考虑土拱效应的非垂直刚性挡墙主动土压力

    Institute of Scientific and Technical Information of China (English)

    孙文君; 宋杨; 王学民; 王蓉蓉; 杨鹏志

    2016-01-01

    为研究非垂直刚性挡墙的主动土压力计算方法,根据土拱效应原理、微分水平层法以及水平向静力平衡条件,得到了平移模式下非垂直刚性挡土墙墙后填土破裂角的计算式,并进一步根据力与力矩平衡条件获得了平移模式下非垂直刚性挡土墙墙后主动土压力、合力及其作用点等的计算式。通过计算对各种特殊情况下的破裂角和主动土压力进行分析,讨论了墙背倾角、墙土摩擦角等对破裂角、法向主动土压力系数、法向主动土压力和主动土压力合力作用点高度等的影响。该研究可为非垂直墙背的支挡结构设计中的主动土压力计算提供更为合理的理论支持。%Active earth pressure for non﹣vertical rigid retaining wall is studied. Considering soil arching effect,according to differential level layer method and horizontal static equilibrium,a new formula of the inclinations of sliding surface behind the inclined rigid retaining wall is obtained under translation mode. Then according to static and moment equilibrium,a new expression of the active earth pressure were derived,and those of the active earth force and the height of application of its is also putted for﹣ward. The special solutions of the failure angle and the active normal earth pressure are discussed under various boundary conditions. In addition,the effects of the inclination of wall﹣back surface,the internal friction angle of backfill and the wall﹣soil friction angle on the failure angle,the active normal earth pres﹣sure and its coefficient,and application height the active earth force is investigated. This study can provide a more reasonable theoretical support for the design calculation of the active earth pressure against the non﹣vertical rigid retaining structures.

  11. 不同变位模式刚性挡土墙的动被动土压力%Dynamic passive earth pressure on retaining wall under various modes of movement

    Institute of Scientific and Technical Information of China (English)

    彭润民; 纪秋林

    2009-01-01

    Based on Mononobe-Okabe's postulation, the first-order differential equation for passive earth pressure on the retaining wall was set up for the translation(T)mode, movement modes of rotation around base(RB)and rotation around top (RT) by analyzing slice elements extracted from sliding soil wedge; and the formulas for calculating of the unit earth pressure, the resultant earth pressure and the action point of resultant pressure were given. The comparison between calculated results by the present formulas and Coulomb's theory shows that the unit earth pressure is nonlinearly distributed; and that the distance from the action point of resultant pressure to the base of wall increases with the order of (RB)mode, (T)mode, and (RT) mode.%基于Mononobe-Okabe假定,通过对滑动土体中水平薄层单元的分析,建立了墙体平动(T)模式、墙体绕基础转动(RB)模式和墙体绕墙顶转动(RT)模式下的被动土压力的一阶微分方程,给出了土压力强度、土压力合力、土压力作用点的理论计算公式,并将该理论计算公式与库仑理论结果进行了比较.结果表明:土压力强度分布呈曲线分布,合力作用点到墙底的距离依(RB)模式、(T)模式和(RT)模式次序增大.

  12. Theory of earth pressure against rigid retaining wall based on disturbed state concept model%基于扰动状态概念模型的刚性挡土墙土压力理论

    Institute of Scientific and Technical Information of China (English)

    朱剑锋; 徐日庆; 王兴陈

    2011-01-01

    基于扰动状态概念(DSC),结合库伦土压力理论研究平动位移模式下刚性挡土墙的土压力计算方法.以挡墙平动位移量为扰动参量,建立扰动度函数表达式.提出扰动摩擦角概念,建立扰动摩擦角与扰动度之间的关系公式.参照库仑土压力理论,分析任意扰动状态下土楔的最不利受力情况,得到平动位移模式下基于DSC理论刚性挡土墙土压力计算公式.算例分析表明:在任意扰动状态下,基于DSC理论的刚性挡墙土压力计算公式所预测的土压力大小、分布以及土压力系数均与模型试验结果比较吻合.%Through combining with the Coulomb's earth pressure theory, the method of calculating earth pressure against rigid retaining wall under translation mode was studied based on the disturbed state concept (DSC). The disturbance function was established by taking the movement of rigid retaining wall as the disturbed parameter. The disturbed frictional angle concept was proposed and the relationship between the disturbed frictional angle and the disturbed degree was obtained. By analyzing the forces on the most unfavorable soil wedge at arbitrary disturbed state, the general formulas for calculating the earth pressure against rigid retaining wall under translation mode were established based on DSC theory. Calculation results shows that the predicted magnitude and distribution of earth pressure and the coefficients of earth pressure agree well with those of the model test at random disturbed state.

  13. 考虑挡墙位移效应的被动侧土压力计算方法%Computational method of earth pressure at passive side considering wall displacement effect

    Institute of Scientific and Technical Information of China (English)

    宋飞; 张建民

    2011-01-01

    挡土结构上土压力的计算是土力学和岩土工程领域的基本研究课题之一.实际工程中的土压力通常是介于主动土压力和被动土压力之间的某一值,墙后填土由于碾压具有较高的密实度.经典的朗肯和库仑土压力理论只能计算极限状态下的土压力,没有考虑挡墙的位移以及剪切过程中密砂的强度从峰值强度降低到残余强度这一强度变化特性对于土压力的影响.给出了考虑挡墙位移效应的被动侧土压力计算方法,该方法能够同时考虑剪切过程中密砂的强度从峰值强度降低为残余强度这一强度变化特性对被动土压力的影响.通过土压力模型试验结果对计算方法进行了初步验证,计算结果和试验结果吻合较好,表明了该方法的有效性.%Computation of earth pressure acting on retaining structures constitutes an important research subject in the field of geotechnical engineering.In many engineering practices, the retaining wall displacement causing the backfill yield sufficiently cannot take place so that the earth pressure may fall anywhere between active and passive earth pressures.Besides, due to compaction, the backfill is always dense and its shear resistance will decrease from peak resistance to residual state during shear.However, classic Rankine and Coulomb earth pressure theories can only evaluate the earth pressure at the active and passive state.And they cannot consider the effect of reduction of post-peak shear soil resistance on earth pressure.The development of earth pressure at the passive side with wall displacement is studied.On the basis a new methodology is developed to evaluate earth pressures at the passive side under any boundary strain constraint for a rigid retaining structure with translational movement.It can take into account the effect of wall displacement and the strength characteristic of dense sand on earth pressure.The agreement of calculated results with the

  14. Application of Concrete Cutoff Wall in Reinforcement of Earth Rock Dam Seepage Control%混凝土防渗墙在土石坝防渗加固中的应用

    Institute of Scientific and Technical Information of China (English)

    周晓明

    2014-01-01

    Earth rock dam seepage safety problems occupy an important position in the overall security, directly affecting the safe operation of the dam.Concrete diaphragm wall as the main body of water retaining structure of seepage prevention and reinforcement system,anti-seepage effect is most reliable.On the basis of materials and technology analysis,the paper summarizes the problems on design,reinforcement of concrete anti-seepage wall in earth rock dam seepage prevention and construction methods.%土石坝的渗流安全问题在整体安全中占有重要地位,直接影响大坝的运行安全。混凝土防渗墙作为挡水建筑物加固防渗体系的主体部分,防渗效果最为可靠。文章在分析材料及其工艺的基础上,对土石坝防渗加固中混凝土防渗墙的设计、施工方法等问题进行初步总结。

  15. New analysis method of seismic active earth pressure and its distribution on a retaining wall%地震条件下挡土墙主动土压力及其分布的新分析法

    Institute of Scientific and Technical Information of China (English)

    张国祥

    2014-01-01

    The seismic active earth pressure calculations problem with pseudo-static method is translated into non-seismic active earth pressure calculations problem in this paper using the transform method with rotating calculation model of retaining wall. Depend on the non-seismic active earth pressure formulations with differential layer method, the analytical formulas of resultant force of seismic earth pressure, application position of resultant force and distribution of seismic earth pressure with differential layer method are obtained directly, and the analytical solution of critical rupture angle by graphic method. The influencing factors including horizontal and vertical seismic accelerations, batter angle of wall back,cohesion and external friction angle between filler and back of retaining wall, equispaced overloading can be considered. The formulas can be used for seismic active earth pressure calculations of cohesive soil or non-cohesive soil with common border condition. The rotating seismic angle method in this paper is that the seismic active earth pressure calculation model with pseudo-static method is firstly rotated into static active earth pressure calculation model, and the stress states of retaining wall and soil behind retaining wall are not changed, and then the seismic active earth pressures with pseudo-static method are solved by the calculation methods of static active earth pressures. The deducing process of seismic active earth pressure formulations with pseudo-static method is simplified and unified greatly by using the new method. The seismic active earth pressure theory with pseudo-static method is perfected much more.%采用旋转挡土墙计算模型的变换法,将在地震和拟静力法条件下主动土压力的求解问题转化为在静力条件下主动土压力的求解问题。根据在静力条件下水平层分析法的主动土压力推导结果,直接获得在地震条件下主动土压力强度分布、土压力合力及其

  16. Experimental analysis of passive earth pressure against rigid retaining wall under translation mode for finite soils%有限土体刚性挡墙平动模式被动土压力试验研究

    Institute of Scientific and Technical Information of China (English)

    应宏伟; 张金红; 王小刚; 李冰河; 朱伟

    2016-01-01

    It is inappropriate to calculate the earth pressure for finite soils using the classical Coulomb or Rankine earth pressure theory. A series of laboratory model tests with different widths of backfill are conducted for the passive case of a rigid retaining wall subjected to horizontal translation. The change in lateral earth pressure distribution from the at-rest condition to the passive condition is monitored by using a set of pressure cells. The particle image velocimetry technique is employed to observe the development of a failure zone in the soils. The experiment results show that there is a good agreement between the measured earth pressures and the Coulomb’s solution in the case of infinite soils. However, the passive earth pressures on the moving retaining wall for finite soils are much more than the Coulomb’s solution. With the decrease of the soil width, the limited displacement of the wall under passive state seems to increase, and the passive earth pressures also increase significantly when the heights of the application points of the resultant earth pressure move down gradually. Moreover, with the decrease of the soil width, the heave of the backfill surface increases gradually, the inclination angles of the slip surface increase slightly, and the lateral earth pressures on the fixed boundary also increase gradually.%经典的库仑或朗肯土压力理论无法适用有限土体情况下的土压力问题。利用研制的土压力试验模型装置,进行了一组不同填土宽度的刚性挡墙平动模式室内模型试验,采用微型土压力盒量测从静止状态到被动极限状态的水平土压力分布的变化,利用颗粒图像测速技术研究土体内滑裂面发展规律。试验结果表明:半无限土体情况下的被动土压力大小、分布和合力作用点与库仑被动土压力较为接近。而有限宽度情况下移动挡墙上各深度的被动土压力值均大于库仑被动土压力,且土体宽度

  17. Lime-Crusted Rammed Earth: Materials Study

    OpenAIRE

    Mileto, Camilla; Vegas López-Manzanares, Fernando; Alejandre, Francisco Javier; Martín, Juan Jesús; Garcia Soriano, Lidia

    2013-01-01

    This study analyses the durability of rammed-earth wall construction techniques. The analysis focuses on three medieval masonry types from the Castle of Villavieja (Castellón, Spain) using two variations of lime-reinforced rammed earth in its walls: lime-crusted rammed earth and brick-reinforced rammed earth. Materials analysis reveals the good properties of the materials used in the outer wall facing despite its age. It also clearly shows how deterioration depends more on the construction t...

  18. Passive earth pressure on retaining walls calculated by principle of soil arching effect%基于土拱效应原理求解挡土墙被动土压力

    Institute of Scientific and Technical Information of China (English)

    侯键; 夏唐代; 孔祥冰; 孙苗苗

    2012-01-01

    In the translational displacement mode, a stress of wedge soil between rigid retaining wall and sliding surface, which is in the passive state of limit equilibrium, is analyzed. Considering the horizontal equilibrium of the soil between the wall and the slip surface, the formula of passive earth pressure coefficient and the angle of failure line to horizontal are obtained by using the principle of soil arching effect. According to the equilibrium equation considering the static equilibrium conditions of horizontal unit of soil, the formula of the passive earth pressure distribution, the resultant earth pressure and the application point of resultant earth pressure on retaining wall are respectively set up. After comparing the computed result using the method mentioned above with the experiment results and the results obtained on the basis of Coulomb and Rankine theories, it is demonstrated that the calculating results agree well with the experimental results; and thus the calculating method obtained is verified rational.%对平移模式下的刚性挡土墙和滑裂面间的楔形土体处于被动极限平衡状态的应力进行分析,考虑墙面和滑裂面之间土体水平力平衡,运用土拱效应原理推导出被动土压力系数和滑裂面水平倾角.并根据水平单元土体的静力平衡条件建立平衡方程,提出被动土压力分布、土压力合力及其作用位置的公式.将公式计算结果与试验结果以及库仑、朗肯理论所得结果进行比较,结果表明,与试验结果接近,验证了所得计算方法的合理性.

  19. NON-LIMIT STATE EARTH PRESSURE AGAINST RETAINING WALL CONSIDERING INFLUENCE OF DEFORMATION%考虑变位影响的刚性挡墙非极限土压力研究

    Institute of Scientific and Technical Information of China (English)

    陈奕柏; 柯才桐; 高洪波; 陈云

    2015-01-01

    The classic theory of earth pressure can only be used to calculate the limit earth pressure on the retaining wall under the mode of translation. With the Mohr circle expressed with the principal stress difference and on the basis of the radial stress-strain relation obtained from the stress path triaxial tests,the nonlinear relationships of the mobilized internal friction angle of the soil and the friction angle between the wall and the backfill soils vesus the displacement were established under non-limit state. The method of effective area ratio of wall displacement was put forward to quantify the relationship to rigid retaining wall under the deformation mode of rotation. Based on the method above and combined with the method of horizontal slices and the modified Coulumb′s formula,the formula of earth pressure distribution,the resultant force and its application point under non-limit state which considered the influence of wall deformation were deduced. The result of an example showed that the difference between the theoretical calculation value quantified by the method of effective area ratio of displacement and the measured value was small. The proposed formula well reflects the change of earth pressure with the wall displacement and is an effective extension of Coulumb′s theoretical formula.%经典土压力理论仅能计算平移模式挡墙的极限状态土压力。采用以主应力差表示的应力圆,根据应力路径三轴试验中得到的径向应力–应变关系,建立非极限状态下受位移影响的土体内摩擦角、墙土间摩擦角发挥值随位移的变化关系,并提出有效位移面积比方法将该关系量化至转动变位模式挡墙。在此基础上,应用水平层分析法和改进的库仑公式,推导出考虑挡墙变位影响的非极限土压力合力及其作用点位置、土压力分布计算式。研究表明:按有效位移面积比方法进行量化后,理论计算值与实测值相对误差

  20. Study on Shearing Strength of Typical Reinforced Rammed Earth Wall in Gansu Province%甘肃典型夯土民房承重墙体加固试验研究

    Institute of Scientific and Technical Information of China (English)

    徐舜华; 王兰民; 王强; 袁中夏

    2011-01-01

    武都是甘肃省典型夯土民房使用地区,研究其夯土民房的抗震性能对于防灾减灾具有重要意义.在试验中,使用武都当地常用土料,完全按照其施工工艺夯筑4片夯土墙体试件,利用伪静力方法研究了素土墙体与使用铁丝网加固墙体的抗剪强度.结果显示:①在竖向荷载10 kN条件下,加固墙体试件较素土墙体试件的水平开裂荷载和极限荷载分别增长了73%和38%,在竖向荷载18 kN条件下,加固墙体试件素土墙体试件的水平开裂荷载和极限荷载分别增长了76%和5%;②随着竖向荷载从10 kN增加到18 kN,素土墙体试件的水平开裂荷载与极限荷载分别增长了217%和359%,加固墙体试件的水平开裂荷载与极限荷载则增长了223%和249%;③在水平往复荷载的作用下,夯土墙体始终沿着夯土层间的水平和垂直接触裂缝产生破坏,最终碎裂成块体.%Research on seismic performance of typical rammed earth houses is important for disaster prevention and mitigation in Wudu, Gansu province. Four experimental walls are built using local material and local construction technology. The shearing strength of raw soil wall and the wall reinforced by iron mesh are investegated by pseudo-static test, the results show, (1) the horizontal crack load and ultimate load of reinforced walls increases by 73% and 38% than those of raw soil walls under the overlying load of 10kN, and those are 76% and 5% under the overlying load 18kN; (2) the crack load and ultimate load of raw soil wall increases by 217% and 359% with the overlying load increases from 10kN to 18kN, while the growth rates are 223% and 249% separately for reinforced wall; (3) the rammed earth wall always destroys along the horizontal and vertical cracks between layers, and eventually breaks into blocks under horizontal cyclic loading.

  1. 临近地下室外墙影响下的考虑土拱效应的挡土墙主动土压力研究%Research on active earth pressure behind retaining wall adjacent to existing basements exterior wall considering soil arching effects

    Institute of Scientific and Technical Information of China (English)

    赵琦; 朱建明

    2014-01-01

    It was necessary to use the adaptive theory for computing the distribution of earth pressure behind the wall adjacent to existing basements and the height of total earth pressure, because it was inconsistent with the Rankine’s theory which was based on the semi-infinite half space state. It could be divided two parts of the deformation trends by considering soil arching effect. The upper soil parts slide down alongside the wall which is same with Terzaghi’s tarp door experiment. Also, the lower soil parts slide down as a triangle the soil wedge. So it is reliable that the earth pressure behind the retaining wall adjacent to existing basement should be analyzed based on the above deformation trends of the upper part and lower part. Assuming the arch in soil arching as circular, the lateral coefficients of earth pressure of retaining wall about both upper and lower parts are derived from the principal stress rotation. And the formula of distribution of lateral active earth pressure is given based on the soil static wedge equilibrium. Expressions of the total earth pressure and the height of acting point are derived by translation of coordinates. According to the examples, the results by proposed method are close to the simulation results. So it has a significant meaning for active earth pressure theory which considering the soil arching effect.%当挡土墙附近存在临近建筑地下室外墙时,其挡土墙土压力与传统的Rankine理论基于无限半空间体假定不符,因而在这种新的工程背景下需要采用合适的理论来计算挡土墙土压力及其作用点高度。已有的研究表明,这种条件下土体的变形趋势可分为上、下两大部分:上部土体变形类似于Terzaghi的活动门试验,土体沿着墙体下滑,而下部土体则沿着土楔形体而变形。因而将土拱效应用于求解挡土墙土压力的计算分成了上、下两大部分考虑。假定土拱形状为圆弧,基于主应力旋

  2. Analysis of Facing Earth Pressure of Soil-nailing Wall on Double-parameter Foundation%双参数地基上土钉墙面层土压力计算

    Institute of Scientific and Technical Information of China (English)

    王立峰; 祝江鸿

    2012-01-01

    土钉墙面层承受部分土(水)压力,文中把土钉墙面层看作是弹性地基上的有限长梁,在试验的基础上,推导了基于双参数地基的成层土层分布的土钉墙面层在土钉拉力作用下的挠曲线、转角、弯矩和剪力方程,并与实测数据进行了比较分析,验证了模型的合理性,得到的解析解基本上可以反映土钉墙面层土压力的分布.在此基础上,探讨了不同土性土层中土钉墙面层土压力的分布.面层土压力在土层的分界面上位移连续土压力突变;作用在软弱土层的面层土压力比硬土层上的面层土压力大;上软下硬型较上硬下软的土层分布更能使面层土压力得到充分发挥;同时文中计算了面层土压力换算成荷载与土钉拉力的比值,面层对于土压力的作用随着深度的增加表现得愈加明显,提出针对不同地区不同深度和不同土性条件下应给出比值的建议值,以使土钉墙的设计更符合其真实的作用机理.文中得到的结论和计算方法对于进一步研究土钉墙的作用机理及设计中如何充分发挥面层的作用等具有重要的理论意义和实际应用价值.%Present designers of soil-nailing walls consider the facing as accessory structure rather than the main one. However It is absolutely sure that the facing bear against water and earth pressure. Facing isolated and considered as finite beam on elastic foundation simply .solutions of displacement ^angles of rotation,bending moment and shear force of soil-nailing walls are gained on basis of field tests in layered soil. Rationality of the model is tested and verified. The results that can disclose laws of distribution of facing earth pressure are in agreement with the actual measurement datum. Earth pressure in bounding surface shows abrupt changes while displacement of facing exhibits continuous characteristics. Earth pressure of facing applied by soft soil presents bigger values than that of

  3. 考虑单元划分方式的平动挡墙主动土压力分析%Analysis of active earth pressure of considering translational unit modes for retaining wall

    Institute of Scientific and Technical Information of China (English)

    王梅; 侯新平; 李琦

    2015-01-01

    考虑平移模式下刚性挡土墙墙后填土中的土拱效应,分析沿圆弧形拱的切线和割线方向划分微分单元对主动土压力分布的影响。在此基础上,采用二分法求解最优划分方式,得到了作用在挡土墙上的主动土压力公式。与沿切线和割线方法及试验监测结果的对比分析表明:本文方法得到的平移模式下刚性挡墙墙后主动土压力强度小于沿切线划分单元的计算结果,略大于沿割线划分单元的计算值。本文方法得到的刚性挡墙墙后主动土压力分布与模型试验结果吻合最好。%Considering the soil-arching effect of retaining wall backfill of rigid translational mode , the pa-per analyzed the influence of division differential unit on along the arc arch tangent and secant .On above basis,it obtained the formula for the active earth pressure against a rigid retaining wall by means of di -chotomy to the optimum dipartition mode .Through comparing the formula with the theoretical solutions of tangent direction , secant direction and the results of measured test ,the result can be goten that the active earth pressure proposed is smaller than those of tangent direction and larger than those of secant direc -tion.The active earth pressure distribution of rigid wall backfill gotten by the method match best with the physical model test .

  4. 内置绳网承重夯土墙体抗震性能试验研究%Study on seismic behavior of the rammed earth walls with built-in rope nets

    Institute of Scientific and Technical Information of China (English)

    卜永红; 王毅红; 韩岗; 李丽

    2013-01-01

    提出一种内置绳网的生土结构房屋承重夯土墙体及其建造技术,对该种夯土墙与按照传统方法夯筑的承重夯土墙的受力及抗震性能进行试验研究,各设计了一片墙体试件.对试件施加竖向荷载和低周反复水平荷载,对比研究两种夯土墙体在地震荷载作用下的破坏过程、破坏形态、滞回曲线和骨架曲线的特征以及墙体的水平承载力和变形能力等.分析内部设置绳网对夯土墙体水平受力性能和变形性能的影响.研究结果表明,与传统夯土墙相比,内置绳网夯土墙体的承载和变形能力更高,将该种夯土墙应用于生土结构房屋,可使房屋的整体性增强,抗震能力得到提高.%A new design of rammed earth walls with built-in rope nets with its construction technology was proposed. Two specimens were built by way of the new construction technology and traditional construction technology, with the mechanical behavior and seismic behavior studied. Vertical loading and low cycle reversed horizontal loading were carried out on specimens aimed to study the failure process, failure mode, hysteretic curve and skeleton curve feature. The horizontal bearing capacity and deformation capacity of the walls also were studied, with the influence of the built-in rope nets analyzed. Test results indicated that compared with the traditional construction method, the horizontal bearing capacity and deformation capacity of the new design wall was improved by built-in rope nets construction method. Thus, with the built-in rope nets rammed earth walls, the integrity of the raw-soil structure houses is strengthened, and the seismic behavior improved.

  5. 加筋土挡墙变形及筋材受力特征数值试验研究%Numerical experiment studies on deformation and geo-grid force of reinforced earth retaining wall

    Institute of Scientific and Technical Information of China (English)

    万健

    2015-01-01

    Reinforced soil retaining wall is a kind of effective to solve the problem of high fill embankment and slope measures.In this paper, combined with a highway reinforced soil retaining wall project as the research background, with the aid of numerical analysis method and the deformation characteristics of the retaining wal and data col ected in-situ reinforcement material mechanical properties are studied, the analysis results show that the lower part of the retaining wall reinforcement material earth pressure value is the upper reinforcement material location, soil pressure maximum position from the retaining wal (0.3~0.4) H location;Reinforced materials on the tensile stress distribution and the size of the reinforcement materials stress, along the direction of reinforcement material in 0~1m within the scope of the approximate uniform distribution, exponential distribution outside the 1.0m;Maximum tensile strain values near the wall, along the reinforcement length direction tensile strain nonlinear decreasing; Reinforced retaining wall horizontal deformation along the depth are "fat bel y" shape distribution, the maximum horizontal deformation occurred to about one-third of the wall height, the size is about 16.5mm. Wall had a greater influence on the load on retaining wal and soil deformation;suggest the wal load take 30kpa as load limit of reinforced soil retaining wall. Research results can provide reference for design and construction of reinforced soil retaining wall structure.%加筋土挡墙是一种解决高填方路堤及边坡等问题的有效措施。本文结合某公路加筋土挡墙工程为研究背景,借助数值分析方法和现场实测数据对加筋土挡墙变形特性及筋材受力特性进行了研究。分析结果表明:挡墙下部筋材位置土压力值较上层筋材位置大,土压力最大值位置在距挡墙(0.3~0.4)倍的墙高位置处;筋材上的拉应力分布与筋材受力大小有关,沿筋材方向在0

  6. Dynamic Active Earth Pressure on Retaining Wall under Various Modes of Movement%不同变位模式下刚性挡土墙的动主动土压力

    Institute of Scientific and Technical Information of China (English)

    李刚; 张凤涛

    2011-01-01

    On the basis of the Assumption of Mononobe-Okabe theory,the first-order differential equation for active earth pressure on the retaining wall was set up for the translation (T) mode, movement modes of rotation around base (RB) and rotation around top (RT) by analyzing slice elements extracted from the sliding soil wedge. And the formulas for calculating the unit earth pressure, the resultant earth pressure and the action point of the result pressure were given. The comparison between calculated results with the present formulas and Mononobe-Okabe theory has shown that the unit earth pressure is nonlinear-ly distributed;and that the distance from the action point of resultant pressure to the base of wall increases with the order of(RB)mode,(T) mode,and (RT) mode. It has also indicated that the calculated results of the resultant pressure under various modes of movement are in accordance with those of Mononobe-Okabe theory for q0 = 0 .%基于Mononobe-Okabe理论的基本假设,通过对滑动土体中水平薄层单元的分析,建立了墙体平动(T)模式、墙体绕基础转动(RB)模式和墙体绕墙顶转动(RT)模式下的主动土压力的一阶微分方程式,给出了土压力强度、土压力合力、土压力作用点的理论计算公式,并将该理论计算公式与Mononobe-Okabe理论结果进行了比较.结果表明:土压力强度分布呈非线性分布,合力作用点到墙底的距离依(RB)模式、(T)模式和(RT)模式次序增大.当地面荷载q0=0时,各种墙体变位模式下的动土压力合力与Mononobe-Okabe理论相同.

  7. The Compared Test Study about The Material Properties of Rammed Earth Wall of FuJian Tulou and Fuzhou Sanfangqixiang%福建土楼与福州三坊七巷夯土墙材料性能对比试验研究

    Institute of Scientific and Technical Information of China (English)

    李梁峰

    2016-01-01

    福建土楼建筑群与福州三坊七巷建筑群为福建省两大特色文物古建筑群,这两个建筑群的围护墙体均采用夯土墙,但两类夯土墙的性能存在显著的差异性。本文以采用传统工艺建造的新夯土墙及历史既有的夯土墙为样本,对两种不同类型夯土墙的材料配比及材料抗压强度等性能进行了对比试验研究,研究结果表明福建土楼夯土墙的材料抗压强度显著高于福州三坊七巷夯土墙,而材料配比是影响夯土墙材料性能的最主要因素。相关研究成果可作为历史夯土墙修缮及新建夯土墙的技术参考。%There are two special ancient buildings in FuJian: FuJian Tulou and Fuzhou Sanfangqixiang,which are all rammed earth wall buildings. There is significant difference between the two types of rammed earth walls. In this paper, the material ratio and compressive strength of the two types rammed earth walls were compared. The results presented that the compressive strength of rammed earth wall of Fu-Jian Tulou was significantly higher than which of Fuzhou Sanfangqixiang. This research can provide technical reference for repairing histori-cal rammed earth wall and putting up new rammed earth wall.

  8. 西夏陵夯补支顶加固工艺质量控制研究%Quality Control Research on Reinforcement Technology Tests Using Rammed Earth to Fill Unsupported Walls in a Western Xia Imperial Tomb

    Institute of Scientific and Technical Information of China (English)

    张博; 王旭东; 郭青林; 裴强强; 杨善龙; 李凤洁

    2016-01-01

    土坯砌补与夯补支顶是西北干旱环境下加固土遗址悬空区常用的两种技术措施,对于夯筑类土遗址而言,夯补相较于砌补有明显的优势,既能保持遗址本体的原有工艺,避免土坯砌补表面处理层脱落露出砌补层影响观感,同时夯补体本身具有较强的稳定性和较强的抗风蚀、雨蚀能力。但是不同遗址夯土的建筑工艺、土的物理力学性质不同,施工过程中夯补质量无法准确控制。本文针对西夏陵遗址本体根部夯筑砌补,采用与原遗址相近的当地土,以固定质量夯锤为夯筑工具、并以传统人工夯实方法进行夯筑,分析研究夯土密度随铺土厚度和夯筑次数的变化规律,探索最佳铺土厚度和夯筑次数。试验结果表明,当使用2kg夯锤进行夯筑时,铺土厚度为12cm,垂直夯筑4次,即可得到密度较大且密度均匀的最佳夯筑效果。%There are two construction techniques frequently used in reinforcing unsupported regions of earthen structures in arid areas of northwest China:using adobe brick as a masonry complement, and filling the unsupported wall with rammed earth. For archaeological sites made of rammed earth, using soil to fill the top of a structure is better than using adobe brick because this technique is adopted from the original technology of the region and does not affect the physical appearance of the building. In addition, the rammed earth itself has strong stability and resistance to erosion caused by wind and rain. However, the quality of rammed earth cannot be controlled in the construction process precisely due to the different building techniques of the sites and the dif-ferent physical and mechanical properties of the soil. Focusing on the reinforcement of the foot of a wall of a Western Xia imperial tomb with rammed earth, this study utilizes local soil with the same properties of that used at the time, a pounding tool of fixed mass, and the

  9. 狭窄基坑平动模式刚性挡墙被动土压力分析%Study of passive earth pressures against translating rigid retaining walls in narrow excavations

    Institute of Scientific and Technical Information of China (English)

    应宏伟; 郑贝贝; 谢新宇

    2011-01-01

    对于地铁车站、地下管道沟槽等狭窄基坑,其被动区土体宽度有限,不满足半无限体的假定,采用经典的库仑、朗肯土压力理论计算挡墙被动土压力是不合适的.首先建立了无黏性土中狭窄基坑刚性挡墙的有限元分析模型,研究了挡墙相对平移时不同宽度土体的被动滑裂面的分布规律;借鉴库仑平面土楔假定,建立了狭窄基坑刚性平动挡墙被动土压力的理论计算模型,推导了被动极限状态下滑裂面倾角及被动土压力系数的解析公式;再采用水平薄层单元法,得到了被动土压力分布、土压力合力作用点高度的理论公式.结合算例,深入研究了这种工程背景下挡墙被动滑裂面倾角的影响因素,以及被动土压力合力、土压力分布及合力作用点位置与经典库仑土压力理论的差别,与数值计算结果的对比验证了该理论方法的合理性.研究发现,当被动区土体宽度小于满足半无限体的临界值、且墙土摩擦角大于0时,被动滑裂面倾角大于传统库仑被动滑裂面倾角,被动土压力大于经典库仑解,合力作用点高度则小于库仑解,且基坑越窄,墙土摩擦角越大,其差别越大.%For the case of narrow excavations such as subway stations and underground pipe, the width of the soil mass in passive zone is limited, so it's unsuitable to use the classical Coulomb or Rankine earth pressure theory to calculate the passive earth pressure. A finite element numerical model for retaining wall in narrow excavations is presented. The slip surfaces in the soils at passive limiting state with different widths of soils when the walls translating are investigated. Based on the concept of Coulomb sliding soil wedge, a new theoretical model for determining passive earth pressures against translating rigid retaining walls in narrow excavations is proposed. The formulae of the inclination angles of slip surfaces and coefficients of the resultant

  10. Experimental study on seismic behavior of raw-soil structure with rammed earth walls by different construction methods%不同夯筑方法的承重夯土墙体抗震性能试验

    Institute of Scientific and Technical Information of China (English)

    卜永红; 王毅红; 李丽; 刘挺

    2011-01-01

    提出适用于生土结构房屋承重夯土墙体新的施工方法,对采用不同方法夯筑的承重夯土墙体的受力及抗震性能进行试验研究,设计了3个墙体试件,分别采用传统水平分层夯筑、错层夯筑和加销键夯筑。对试件施加竖向荷载和低周反复水平荷载,研究采用不同夯筑方法建造的夯土墙体在地震荷载作用下的破坏过程、破坏形态、滞回曲线和骨架曲线的特征,以及墙体的水平承载力和变形能力等;对比分析不同夯筑方法对夯土墙体水平受力性能和变形性能的影响。研究结果表明,与传统夯筑方法相比,错层夯筑法使墙体的承载和变形能力都得到提高;加销键夯筑使墙体的变形能力得到提高。%New construction methods were put forward to apply to rammed earth walls of raw-soil structure.Three specimens were built by the way of traditional horizontal layer,alternate layer and add-pin-key construction methods,the mechanical behavior and seismic behavior of which were studied.Vertical loading and low cycle reversed horizontal loading were carried out on specimens to study the failure process,failure mode,hysteretic curve and skeleton curve feature.The horizontal bearing capacity and deformation capacity of the walls also were studied,the influence of different construction methods on which was analyzed.Test results indicate that,compared with the traditional construction method,the horizontal bearing capacity and deformation capacity of the wall can be improved by alternate layer construction method,and the deformation capacity of the wall can be improved by add-pin-key construction method.

  11. Steel Sheet Pile Walls in Soft Soil

    NARCIS (Netherlands)

    Kort, D.A.

    2002-01-01

    For almost a century, steel sheet pile walls are applied worldwide as earth retaining structures for excavations and quay walls. Within the framework of the development of European structural codes for Civil Engineering works, the Eurocodes, Eurocode 3 Part 5 for design of steel sheet pile walls was

  12. Predicted Research of the Erosion Damage of the Rammed Earth Wall of Fujian Earth Buildings Caused by the Wind-driven Rain%福建土楼夯土墙风驱雨侵蚀损伤预测研究

    Institute of Scientific and Technical Information of China (English)

    花长城; 彭兴黔; 吴仁伟; 邵昆

    2012-01-01

    The World Heritage Fujian Earth Buildings are located in China's southeast coastal area where is frequently suffered from typhoon and severe weather,the annual amount of rainfall can be as much as 1600 mm.Whenever typhoon landed,the gustiness,gathering with the torrential rain,tends to erode and cause damages to these Earth Buildings,with that,the wind-driven rain's erosion of the rammed earth wall has become the main form causing such damages.The accurate simulation of numerical wind tunnel can be completed by the adoption of methods of CFD numerical simulation and wind tunnel test,according to the analysis of the raindrops' motion form and the rainfall characteristics under the effect of the wind-driven rain.Considering the various combinative conditions of the rain strength and wind speed based on the numerical wind field and rainfall model,followed by analyzing the erosion damage of the rammed earth wall caused by the weather beaten,in such way,whose inherent regularity can be revealed.The last step is to predict the annual range of average erosion damage which is from 0.4 mm to 2.6 mm by the calculation example based on the local meteorological statistical data.The result will provide the earth buildings' maintenance reinforcement and exploitation with scientific basis,and provide the other rammed earth architecture with reference as well.%世界文化遗产福建土楼地处中国东南沿海,年降雨高达1 600 mm,频繁遭受台风和极端天气袭击,每当台风登陆时,狂风挟着暴雨常常侵蚀危害着土楼建筑,风驱雨冲击侵蚀土楼夯土墙已成为土楼建筑的主要损坏形式。论文通过分析风驱雨作用下雨滴的运动形式及降雨特征,采用CFD数值模拟及风洞试验的方法完成数值风洞准确性模拟,以数值风场为基础加入降雨模型,考虑多种雨强和风速相互组合,分析风驱雨对土楼夯土墙的风雨侵蚀影响,揭示了夯土墙风雨侵蚀的内在规律。并通过

  13. 基于非线性破坏准则的挡土墙被动土压力上限分析%Upper Bound Solutions for Passive Earth Pressure of Retaining Wall Basedon Nonlinear Failure Criterion

    Institute of Scientific and Technical Information of China (English)

    李丽民; 张国祥; 王恭兴

    2011-01-01

    传统的挡土墙土压力计算基于Mohr-Coulomb线性破坏准则,但大量试验数据表明,土体破坏时最大主应力和最小主应力的关系是非线性的.为此,基于Mohr-Coulomb非线性破坏准则,将挡土墙后填土划分为多个刚性滑块组成的破坏机构,根据极限分析中的上限理论建立容许的速度场.根据岩土实际应力情况,不同边界采用不同的切线强度计算参数,提出一种“多切线法”,推导得出挡土墙被动土压力的解析表达式,通过大型数学规划理论优化得到最优上限解.计算结果表明:当非线性破坏准则变为线性破坏准则时,结果与前人成果一致;非线性参数m、超载q、初始黏结力C0对被动土压力有重要影响;与单切线法相比,采用多切线法理论上更加严密,计算结果更接近真实值,具有较高的实用价值.%Conventional calculations of earth pressure for retaining walls are made in terms of the linear Mohr-Coulomb (MC) failure criterion. However, a substantial amount of experimental data shows that the relationship between the first principal stress and the third principal stress is nonlinear when soil is broken. Therefore, based on the Mohr-Coulomb nonlinear failure criterion and the multi-wedge translation failure mechanism, considering the effect of normal stress distribution on the cohesion and the internal friction angle, giving different boundary surfaces to different cohesion and internal friction angle, by the optimization theory, the multi-tangential technique is used to deduce the passive earth pressures of retaining walls. The minimum solution is obtained by optimization. From the calculation results, it can be seen that if the nonlinear Mohr-Coulomb yield criterion turns into the linear Mohr-Coulomb yield criterion, then the solutions presented in this paper agree well with the chen and soubra research conclusions, and the nonlinear parameter, overloading and initial cohesion have significant

  14. Wonderful Walls

    Science.gov (United States)

    Greenman, Jim

    2006-01-01

    In this article, the author emphasizes the importance of "working" walls in children's programs. Children's programs need "working" walls (and ceilings and floors) which can be put to use for communication, display, storage, and activity space. The furnishings also work, or don't work, for the program in another sense: in aggregate, they serve as…

  15. Ambiguous walls

    DEFF Research Database (Denmark)

    Mody, Astrid

    2012-01-01

    The introduction of Light Emitting Diodes (LEDs) in the built environment has encouraged myriad applications, often embedded in surfaces as an integrated part of the architecture. Thus the wall as responsive luminous skin is becoming, if not common, at least familiar. Taking into account how wall...

  16. Fire behaviour of tabique walls

    OpenAIRE

    Araújo, Alexandre; Fonseca, E.M.M.; Ferreira, Débora; P. A. G. Piloto; Pinto,Jorge

    2015-01-01

    The tabique is one of the main Portuguese traditional building techniques, which is based on raw materials as earth and wood. In general, a tabique wall is formed by a simple timber structure covered by an earth-based material. Earth has an important role in this system because it protects the internal timber structure along with its finishing function. The Trás-os-Montes e Alto Douro is the northeast region of Portugal and it is very rich in terms of tabique construction heritage. Nowadays, ...

  17. The State of the GeoWall

    Science.gov (United States)

    Morin, P. J.; Leigh, J.; van Keken, P.; Johnson, A.

    2003-12-01

    The GeoWall stereo projection technology has been widely adopted within Earth Science. Over 20,000 undergraduate students per year use a GeoWall in classroom and lab settings at over 80 institutions around the world using over 200 GeoWalls. We believe that critical mass for this technology has been reached in the Earth Science. Many collaborations have been initiated. With Iris, GeoWall is exploring new ways to monitor seismic networks in real-time and to visualize extremely large, whole Earth seismic simulations. We are also working with a number of drilling organizations including JOI, DOSECC and LacCore to bring modern visualization technology to core interpretation and drill site selection. Also, over 15 museums now have or are building GeoWalls for informal education. Much of the science that is being performed on the GeoWall is finding its way directly into the classroom and science museum. One of the success stories has been the GeoWall Consortium's interaction with industry. The basic hardware for the GeoWall has been spun off to companies that now sell variations of the hardware. In addition, many software companies including ESRI and Dynamic Graphics have added support for the GeoWall in their products. The future of GeoWall is four fold. Curriculum development will bring more material to all GeoWall users. Assessment of the curriculum and educational psychology will give us GeoWall best practices. In technology development, the GeoWall 2 is a 20+ million pixel, tiled display which brings more resolution to the Earth Sciences than ever. To support research the consortium is developing a volume rendering application to visualize extremely large datasets.

  18. Wall Turbulence.

    Science.gov (United States)

    Hanratty, Thomas J.

    1980-01-01

    This paper gives an account of research on the structure of turbulence close to a solid boundary. Included is a method to study the flow close to the wall of a pipe without interferring with it. (Author/JN)

  19. Expanding earth

    Energy Technology Data Exchange (ETDEWEB)

    Carey, S.W.

    1976-01-01

    Arguments in favor of an expanding earth are presented. The author believes that the theory of plate tectonics is a classic error in the history of geology. The case for the expanding earth is organized in the following way: introductory review - face of the earth, development of expanding earth concept, necessity for expansion, the subduction myth, and definitions; some principles - scale of tectonic phenomena, non-uniformitarianism, tectonic profile, paleomagnetism, asymmetry of the earth, rotation of the earth, and modes of crustal extension; regional studies - western North America, Central America, South-East Asia, and the rift oceans; tests and cause of expansion. 824 references, 197 figures, 11 tables. (RWR)

  20. Wall Art

    Science.gov (United States)

    McGinley, Connie Q.

    2004-01-01

    The author of this article, an art teacher at Monarch High School in Louisville, Colorado, describes how her experience teaching in a new school presented an exciting visual challenge for an art teacher--monotonous brick walls just waiting for decoration. This school experienced only minimal instances of graffiti, but as an art teacher, she did…

  1. CLIMBING WALL

    CERN Multimedia

    1999-01-01

    The FIRE AND RESCUE Group of TIS Commission informs that the climbing wall in the yard of the Fire-fighters Station, is intended for the sole use of the members of that service, and recalls that access to this installation is forbidden for safety reasons to all persons not belonging to the Service.CERN accepts no liability for damage or injury suffered as a result of failure to comply with this interdiction.TIS/DI

  2. Dynamic active earth pressure on retaining structures

    Indian Academy of Sciences (India)

    Deepankar Choudhury; Santiram Chatterjee

    2006-12-01

    Earth-retaining structures constitute an important topic of research in civil engineering, more so under earthquake conditions. For the analysis and design of retaining walls in earthquake-prone zones, accurate estimation of dynamic earth pressures is very important. Conventional methods either use pseudo-static approaches of analysis even for dynamic cases or a simple single-degree of freedom model for the retaining wall–soil system. In this paper, a simplified two-degree of freedom mass–spring–dashpot (2-DOF) dynamic model has been proposed to estimate the active earth pressure at the back of the retaining walls for translation modes of wall movement under seismic conditions. The horizontal zone of influence on dynamic earth force on the wall is estimated. Results in terms of displacement, velocity and acceleration-time history are presented for some typical cases, which show the final movement of the wall in terms of wall height, which is required for the design. The non-dimensional design chart proposed in the present study can be used to compute the total dynamic earth force on the wall under different input ground motion and backfill conditions. Finally, the results obtained have been compared with those of the available Scott model and the merits of the present results have been discussed.

  3. Earth\\'s Mass Variability

    CERN Document Server

    Mawad, Ramy

    2014-01-01

    The perturbation of the Earth caused by variability of mass of Earth as additional reason with gravity of celestial bodies and shape of the Earth. The Earth eating and collecting matters from space and loss or eject matters to space through its flying in the space around the Sun. The source of the rising in the global sea level is not closed in global warming and icebergs, but the outer space is the additional important source for this rising. The Earth eats waters from space in unknown mechanism. The mass of the Earth become greater in November i.e. before transit apoapsis two months, and become latter in February i.e. after transit apoapsis to two months.

  4. 砂土中刚性挡墙不同主动变位模式任意位移土压力计算%EARTH PRESSURES ON RIGID RETAINING WALLS IN SANDY SOIL WITH DIFFERENT ACTIVE MOVEMENT MODES UNDER ARBITRARRY DEFORMATION

    Institute of Scientific and Technical Information of China (English)

    应宏伟; 郑贝贝

    2012-01-01

    已有模型实验及现场实测表明,刚性挡墙随着变位模式和位移量的变化,主动土压力合力和分布均发生改变,有时甚至与经典理论的线性分布有很大不同。采用中间状态系数定义非极限状态,提出了砂土中刚性挡墙不同主动位移模式下非极限状态土压力合力系数的计算公式;将墙后士体简化为连续非线性弹簧和刚塑性体的组合体作用在挡墙上,得到了不同位移模式任意位移的土压力分布和合力作用点高度。与已有理论方法和实验结果对比表明,该文方法在三种典型位移模式下与实验数据吻合更好。研究还发现,平动模式土压力呈线性分布,其合力随挡墙位移量的增大易趋于稳定并到达极限状态;绕墙底和绕墙顶转动模式下土压力合力随着位移增大只能接近极限状态且呈非线性分布。绕底转动时,土压力分布曲线逐渐向上凹,合力作用点高度趋于降低;绕顶转动时,分布曲线则逐渐向上凸,合力作用点高度趋于升高,墙顶附近表现出明显的土拱效应。%Previous experimental and monitored results on earth pressures had shown that the resultant and distribution of active earth pressures on rigid retaining wails varied with modes and magnitudes of wall movement. The distribution of earth pressures sometimes differed obviously from a linear distribution according to classical earth pressure theories. A middle-state coefficient was adopted to define the non-limit state, and the formulae of the coefficients of the resultant earth pressures on rigid retaining walls in sandy backfills at a non-limit state with different deformations were proposed. The soil behind the wall was simplified as the combination of nonlinear springs and a rigid plasticity object which applied on the wall, and the unit active pressure and the heights of points of application of pressures were obtained. The comparisons among the

  5. 基于离散元颗粒抗转模型的平移刚性挡墙被动土压力分析%Distinct element simulation of passive earth pressure against a translating rigid wall using a rolling resistance contact model

    Institute of Scientific and Technical Information of China (English)

    蒋明镜; 贺洁; 刘芳

    2012-01-01

    A model considering rolling resistance in particles is introduced into the distinct element method (DEM) for analyzing the earth pressure against a rigid wall subjected to translation movements in the passive state. The evolution of earth pressure with the wall displacement is analyzed together with micro mechanical parameters by comparing the cases with and without considering the rolling resistance of particles in the granular backfill. Results show that the earth pressure increases linearly with the increase of the wall depth regardless of the effect of rolling resistance; and the total thrust acts at approximately one third of the wall height from the base of the wall in both cases. The increase of the resultant earth pressure with displacement is more prominent in the case considering rolling resistance than that neglecting the rolling resistance. The result considering rolling resistance is more close to the classic Coulomb's solution. According to the field of average pure rotation rate, the velocity of soil particles adjacent to the base of the rigid wall is larger, implying a quick energy dissipation taking place at that region, and it becomes even larger in the case considering the rolling resistance than that in the case without considering the rolling resistance.%将颗粒抗转动模型引入离散元程序中,模拟了砂性填土刚性挡土墙平移过程中的被动土压力发展过程,对比分析了考虑和不考虑抗转两种情况下墙后土压力随位移的变化规律及墙后填土微观物理量的变化规律,揭示了颗粒抗转动能力对墙后土压力大小和分布的影响.研究结果表明,不管是否考虑颗粒抗转动作用,被动土压力沿墙深基本呈线性分布,且合力作用点维持在距墙底1/3墙高处,但考虑颗粒抗转动作用时总土压力随位移量增大的幅度更加明显,且模拟结果更接近Coulomb 理论解.平均纯转动率的分析结果表明,挡墙平移时墙底处颗粒转动

  6. Seismic design of earth-retaining structures and foundations

    OpenAIRE

    Choudhury, Deepankar; Sitharam, TG; Rao, Subba KS

    2004-01-01

    Earthquake-resistant design of earth retaining structures like retaining walls, earth dams and foundations are very important problems to minimize the devastating effect of earthquake hazards. In this paper a comprehensive review for different methods to calculate seismic earth pressures and their point of applications is shown. Numerical example shows the merit of a displacement-based analysis over force-based analysis by considering a permissible displacement of the wall.Modification of IS ...

  7. Earth materials and earth dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, K; Shankland, T. [and others

    2000-11-01

    In the project ''Earth Materials and Earth Dynamics'' we linked fundamental and exploratory, experimental, theoretical, and computational research programs to shed light on the current and past states of the dynamic Earth. Our objective was to combine different geological, geochemical, geophysical, and materials science analyses with numerical techniques to illuminate active processes in the Earth. These processes include fluid-rock interactions that form and modify the lithosphere, non-linear wave attenuations in rocks that drive plate tectonics and perturb the earth's surface, dynamic recrystallization of olivine that deforms the upper mantle, development of texture in high-pressure olivine polymorphs that create anisotropic velocity regions in the convecting upper mantle and transition zone, and the intense chemical reactions between the mantle and core. We measured physical properties such as texture and nonlinear elasticity, equation of states at simultaneous pressures and temperatures, magnetic spins and bonding, chemical permeability, and thermal-chemical feedback to better characterize earth materials. We artificially generated seismic waves, numerically modeled fluid flow and transport in rock systems and modified polycrystal plasticity theory to interpret measured physical properties and integrate them into our understanding of the Earth. This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL).

  8. Falling walls

    CERN Multimedia

    It was 20 years ago this week that the Berlin wall was opened for the first time since its construction began in 1961. Although the signs of a thaw had been in the air for some time, few predicted the speed of the change that would ensue. As members of the scientific community, we can take a moment to reflect on the role our field played in bringing East and West together. CERN’s collaboration with the East, primarily through links with the Joint Institute for Nuclear Research, JINR, in Dubna, Russia, is well documented. Less well known, however, is the role CERN played in bringing the scientists of East and West Germany together. As the Iron curtain was going up, particle physicists on both sides were already creating the conditions that would allow it to be torn down. Cold war historian Thomas Stange tells the story in his 2002 CERN Courier article. It was my privilege to be in Berlin on Monday, the anniversary of the wall’s opening, to take part in a conference entitled &lsquo...

  9. Wall to Wall Optimal Transport

    CERN Document Server

    Hassanzadeh, Pedram; Doering, Charles R

    2013-01-01

    The calculus of variations is employed to find steady divergence-free velocity fields that maximize transport of a tracer between two parallel walls held at fixed concentration for one of two constraints on flow strength: a fixed value of the kinetic energy or a fixed value of the enstrophy. The optimizing flows consist of an array of (convection) cells of a particular aspect ratio Gamma. We solve the nonlinear Euler-Lagrange equations analytically for weak flows and numerically (and via matched asymptotic analysis in the fixed energy case) for strong flows. We report the results in terms of the Nusselt number Nu, a dimensionless measure of the tracer transport, as a function of the Peclet number Pe, a dimensionless measure of the energy or enstrophy of the flow. For both constraints the maximum transport Nu_{MAX}(Pe) is realized in cells of decreasing aspect ratio Gamma_{opt}(Pe) as Pe increases. For the fixed energy problem, Nu_{MAX} \\sim Pe and Gamma_{opt} \\sim Pe^{-1/2}, while for the fixed enstrophy scen...

  10. Snowball Earth

    OpenAIRE

    2016-01-01

    In the ongoing quest to better understand where life may exist elsewhere in the Universe, important lessons may be gained from our own planet. In particular, much can be learned from planetary glaciation events that Earth suffered ∼600 million years ago, so-called `Snowball Earth' episodes. I begin with an overview of how the climate works. This helps to explain how the ice-albedo feedback effect can destabilise a planet's climate. The process relies on lower temperatures causing more ice to ...

  11. Digital Earth - A sustainable Earth

    Science.gov (United States)

    Mahavir

    2014-02-01

    All life, particularly human, cannot be sustainable, unless complimented with shelter, poverty reduction, provision of basic infrastructure and services, equal opportunities and social justice. Yet, in the context of cities, it is believed that they can accommodate more and more people, endlessly, regardless to their carrying capacity and increasing ecological footprint. The 'inclusion', for bringing more and more people in the purview of development is often limited to social and economic inclusion rather than spatial and ecological inclusion. Economic investment decisions are also not always supported with spatial planning decisions. Most planning for a sustainable Earth, be at a level of rural settlement, city, region, national or Global, fail on the capacity and capability fronts. In India, for example, out of some 8,000 towns and cities, Master Plans exist for only about 1,800. A chapter on sustainability or environment is neither statutorily compulsory nor a norm for these Master Plans. Geospatial technologies including Remote Sensing, GIS, Indian National Spatial Data Infrastructure (NSDI), Indian National Urban Information Systems (NUIS), Indian Environmental Information System (ENVIS), and Indian National GIS (NGIS), etc. have potential to map, analyse, visualize and take sustainable developmental decisions based on participatory social, economic and social inclusion. Sustainable Earth, at all scales, is a logical and natural outcome of a digitally mapped, conceived and planned Earth. Digital Earth, in fact, itself offers a platform to dovetail the ecological, social and economic considerations in transforming it into a sustainable Earth.

  12. Comparative study of Trombe wall, water wall and trans wall

    Energy Technology Data Exchange (ETDEWEB)

    Sodha, M.S.; Bansal, N.K.; Singh, S.; Ram, S.; Annamalai, M.; Iyer, M.V.; Nirmala, K.A.; Venkatesh, P.; Prasad, C.R.; Subramani, C.

    1982-01-01

    The thermal performances of three systems viz. Trombe wall: (1) without; and (2) with vents (forced air circulation), water wall and Transwall have been studied analytically interms of heat flux entering the living space (Maintained at 20/sup 0/C) corresponding to the meteriological data on January 19, 1981 at New Delhi (India), a typical cold winter day. Subsequent parametric studies using the simulation indicated that the Transwall system is the more efficient system for the passive heating of buildings.

  13. 库什塔依水电站冬季施工的碾压式土石坝沥青混凝土心墙配合比试验研究%Experimental Study on the Mix Proportion of the Asphalt Concrete Core Wall of Rolled Earth-rock Dam in Winter Construction of Cush Kobita Bea Hydropower Station

    Institute of Scientific and Technical Information of China (English)

    张庆春

    2014-01-01

    库什塔依水电站位于寒冷地区,沥青混凝土心墙施工期较短,为加快工程施工进度,提前发挥发电效益,对其沥青混凝土心墙冬季低温施工的配合比进行了试验研究,并通过模拟试验验证了-25℃低温条件下的施工工艺。主要包括确定适合冬季低温施工的配合比,冬季施工沥青混凝土的分离度、层间结合性能、压实效果、接合面渗透性及沥青混凝土的力学特性。试验成果表明,沥青混凝土的各项性能均满足设计要求。%Cush Kobita Bea Hydropower Station is located in cold region of Xinjiang ,which leaves shorter time for the construction of asphalt concrete core wall of the rolled earth-rock dam .In order to shorten the construction time and make it possible for the station to operate in advance ,the mix propotion of asphalt concrete core wall were studied for winter low temperature construction .The construction process were simulated at -25℃ to test for resolution ,performance be-tween the layers ,compaction effect ,permeability of contact face and physical-mechanical properties of the asphalt con-crete .The results indicate that the properties of the asphalt concrete can meet the design requirements .

  14. Study on Seepage Stability Mechanism of an Inclined-wall Earth and Rockfill Dam Based on Muddy Water Seepage Theory%基于浑水渗流理论的某斜心墙土石坝渗流稳定机理研究

    Institute of Scientific and Technical Information of China (English)

    姚锋杰

    2012-01-01

    The seepage stability of a medium-sized reservoir with seepage is studied herein. Based on steady seepage theory and combining with the muddy water seepage theory, the seepage of filter layer of the inclined-wall earth and rockfill dam is calculated by the finite element software Geo-Studio, in which, the permeability coefficient of dam material itself is taken as the initial parameters, and the variation law of permeability coefficient by indoor muddy water tests is considered. The calculation shows that the unreasonable design of filter layer is the main cause of piping failure and inclined-wall collapse. It is suggested that increasing the thickness of impervious body and setting protective layer should be considered as the primary means for the reinforcement of dam.%以某中型水库为研究对象,基于稳定渗流理论,结合浑水渗流理论,以材料本身的渗透系数为初始参数,考虑室内试验所得的浑水作用的渗透系数变化规律,采用有限元软件Geo-Studio进行反滤层渗流计算,对其破坏形式及破坏结果进行分析.计算结果表明,斜墙反滤层设计不合理是发生管涌破坏并在斜墙产生塌坑的主要原因,建议除险加固从加大防渗体厚度和设置保护层入手.

  15. Sulfur Earth

    Science.gov (United States)

    de Jong, B. H.

    2007-12-01

    Variations in surface tension affect the buoyancy of objects floating in a liquid. Thus an object floating in water will sink deeper in the presence of dishwater fluid. This is a very minor but measurable effect. It causes for instance ducks to drown in aqueous solutions with added surfactant. The surface tension of liquid iron is very strongly affected by the presence of sulfur which acts as a surfactant in this system varying between 1.9 and 0.4 N/m at 10 mass percent Sulfur (Lee & Morita (2002), This last value is inferred to be the maximum value for Sulfur inferred to be present in the liquid outer core. Venting of Sulfur from the liquid core manifests itself on the Earth surface by the 105 to 106 ton of sulfur vented into the atmosphere annually (Wedepohl, 1984). Inspection of surface Sulfur emission indicates that venting is non-homogeneously distributed over the Earth's surface. The implication of such large variation in surface tension in the liquid outer core are that at locally low Sulfur concentration, the liquid outer core does not wet the predominantly MgSiO3 matrix with which it is in contact. However at a local high in Sulfur, the liquid outer core wets this matrix which in the fluid state has a surface tension of 0.4 N/m (Bansal & Doremus, 1986), couples with it, and causes it to sink. This differential and diapiric movement is transmitted through the essentially brittle mantle (1024 Pa.s, Lambeck & Johnson, 1998; the maximum value for ice being about 1030 Pa.s at 0 K, in all likely hood representing an upper bound of viscosity for all materials) and manifests itself on the surface by the roughly 20 km differentiation, about 0.1 % of the total mantle thickness, between topographical heights and lows with concomitant lateral movement in the crust and upper mantle resulting in thin skin tectonics. The brittle nature of the medium though which this movement is transmitted suggests that the extremes in topography of the D" layer are similar in range to

  16. Domain Walls on Singularities

    CERN Document Server

    Halyo, Edi

    2009-01-01

    We describe domain walls that live on $A_2$ and $A_3$ singularities. The walls are BPS if the singularity is resolved and non--BPS if it is deformed and fibered. We show that these domain walls may interpolate between vacua that support monopoles and/or vortices.

  17. The Lamportian cell wall

    Energy Technology Data Exchange (ETDEWEB)

    Keiliszewski, M.; Lamport, D. (Michigan State Univ. Plant Research Lab., East Lansing (United States))

    1991-05-01

    The Lamportian Warp-Weft hypothesis suggests a cellulose-extensin interpenetrating network where extensin mechanically couples the load-bearing cellulose microfibrils in a wall matrix that is best described as a microcomposite. This model is based on data gathered from the extensin-rich walls of tomato and sycamore cell suspension culture, wherein extensin precursors are insolubilized into the wall by undefined crosslinks. The authors recent work with cell walls isolated from intact tissue as well as walls from suspension cultured cells of the graminaceous monocots maize and rice, the non-graminaceous monocot asparagus, the primitive herbaceous dicot sugar beet, and the gymnosperm Douglas Fir indicate that although extensins are ubiquitous to all plant species examined, they are not the major structural protein component of most walls examined. Amino acid analyses of intact and HF-treated walls shows a major component neither an HRGP, nor directly comparable to the glycine-rich wall proteins such as those associated with seed coat walls or the 67 mole% glycine-rich proteins cloned from petunia and soybean. Clearly, structural wall protein alternatives to extensin exist and any cell wall model must take that into account. If we assume that extracellular matrices are a priori network structures, then new Hypless' structural proteins in the maize cell wall raise questions about the sort of network these proteins create: the kinds of crosslinks involved; how they are formed; and the roles played by the small amounts of HRGPs.

  18. Halogenation of microcapsule walls

    Science.gov (United States)

    Davis, T. R.; Schaab, C. K.; Scott, J. C.

    1972-01-01

    Procedure for halogenation of confining walls of both gelatin and gelatin-phenolic resin capsules is similar to that used for microencapsulation. Ten percent halogen content renders capsule wall nonburning; any higher content enhances flame-retardant properties of selected internal phase material. Halogenation decreases permeability of wall material to encapsulated materials.

  19. Abdominal wall fat pad biopsy

    Science.gov (United States)

    Amyloidosis - abdominal wall fat pad biopsy; Abdominal wall biopsy; Biopsy - abdominal wall fat pad ... method of taking an abdominal wall fat pad biopsy . The health care provider cleans the skin on ...

  20. Liquid Wall Chambers

    Energy Technology Data Exchange (ETDEWEB)

    Meier, W R

    2011-02-24

    The key feature of liquid wall chambers is the use of a renewable liquid layer to protect chamber structures from target emissions. Two primary options have been proposed and studied: wetted wall chambers and thick liquid wall (TLW) chambers. With wetted wall designs, a thin layer of liquid shields the structural first wall from short ranged target emissions (x-rays, ions and debris) but not neutrons. Various schemes have been proposed to establish and renew the liquid layer between shots including flow-guiding porous fabrics (e.g., Osiris, HIBALL), porous rigid structures (Prometheus) and thin film flows (KOYO). The thin liquid layer can be the tritium breeding material (e.g., flibe, PbLi, or Li) or another liquid metal such as Pb. TLWs use liquid jets injected by stationary or oscillating nozzles to form a neutronically thick layer (typically with an effective thickness of {approx}50 cm) of liquid between the target and first structural wall. In addition to absorbing short ranged emissions, the thick liquid layer degrades the neutron flux and energy reaching the first wall, typically by {approx}10 x x, so that steel walls can survive for the life of the plant ({approx}30-60 yrs). The thick liquid serves as the primary coolant and tritium breeding material (most recent designs use flibe, but the earliest concepts used Li). In essence, the TLW places the fusion blanket inside the first wall instead of behind the first wall.

  1. Solar heating wall

    Energy Technology Data Exchange (ETDEWEB)

    Schoenfelder, J.L.

    1983-08-16

    A solar heating wall is disclosed including a water pipe circulation system having a plurality of separate tubes, each formed as a loop, connected between a water supply and a return. The separate tubes are arranged in a single vertical plane at the approximate center of the wall. The wall is formed within a frame which is packed with a material suited for use as a thERMAL RESERVOIR, SUCH AS concrete. The frame provides extra support by having a series of horizontally disposed cross supports on one surface of the wall and a series of vertically disposed cross supports on the opposite surface A pressure relief valve may be provided between the water supply to the separate tubes and the water supply to the building or structure containing the solar wall, so that the solar wall can be adapted for use with a city water system.

  2. Earth architecture in north of Portugal: case study from vernacular to contemporary

    OpenAIRE

    Mendonça, Paulo

    2014-01-01

    This paper refers to earth solutions in Portugal, covering from a synthesis of vernacular examples to a contemporary approach suggested by the author. This approach consists on a non structural earth wall solution, using a conventional steel reinforced concrete structure in order to permit earth walls to be used both in single-storey as in multi-storey buildings and be accepted in fulfilling contemporary demands of structural and functional performance. A thermal zoning strategy with two dist...

  3. First Exploratory Study on the Ageing of Rammed Earth Material.

    Science.gov (United States)

    Bui, Quoc-Bao; Morel, Jean-Claude

    2014-12-23

    Rammed earth (RE) is attracting renewed interest throughout the world thanks to its "green" characteristics in the context of sustainable building. In this study, the ageing effects on RE material are studied on the walls which have been constructed and exposed for 22 years to natural weathering. First, mechanical characteristics of the "old" walls were determined by two approaches: in-situ dynamic measurements on the walls; laboratory tests on specimens which had been cut from the walls. Then, the walls' soil was recycled and reused for manufacturing of new specimens which represented the initial state. Comparison between the compressive strength, the Young modulus of the walls after 22 years on site and that of the initial state enables to assess the ageing of the studied walls.

  4. Cell Wall Proteome

    OpenAIRE

    Boudart, Georges; Minic, Zoran; Albenne, Cécile; Canut, Hervé; Jamet, Elisabeth; Pont-Lezica, Rafael F

    2007-01-01

    In this chapter, we will focus on the contribution of proteomics to the identification and determination of the structure and function of CWPs as well as discussing new perspectives in this area. The great variety of proteins found in the plant cell wall is described. Some families, such as glycoside hydrolases, proteases, lectins, and inhibitors of cell wall modifying enzymes, are discussed in detail. Examples of the use of proteomic techniques to elucidate the structure of various cell wall...

  5. Staggered domain wall fermions

    CERN Document Server

    Hoelbling, Christian

    2016-01-01

    We construct domain wall fermions with a staggered kernel and investigate their spectral and chiral properties numerically in the Schwinger model. In some relevant cases we see an improvement of chirality by more than an order of magnitude as compared to usual domain wall fermions. Moreover, we present first results for four-dimensional quantum chromodynamics, where we also observe significant reductions of chiral symmetry violations for staggered domain wall fermions.

  6. Green walls in Vancouver

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, R. [Sharp and Diamond Landscape Architecture Inc., Vancouver, BC (Canada)

    2007-07-01

    With the renewed interest in design for microclimate control and energy conservation, many cities are implementing clean air initiatives and sustainable planning policies to mitigate the effects of urban climate and the urban heat island effect. Green roofs, sky courts and green walls must be thoughtfully designed to withstand severe conditions such as moisture stress, extremes in temperature, tropical storms and strong desiccating winds. This paper focused on the installation of green wall systems. There are 2 general types of green walls systems, namely facade greening and living walls. Green facades are trellis systems where climbing plants can grow vertically without attaching to the surface of the building. Living walls are part of a building envelope system where plants are actually planted and grown in a wall system. A modular G-SKY Green Wall Panel was installed at the Aquaquest Learning Centre at the Vancouver Aquarium in Stanley Park in September 2006. This green wall panel, which was originally developed in Japan, incorporates many innovative features in the building envelope. It provides an exterior wall covered with 8 species of plants native to the Coastal Temperate Rain Forest. The living wall is irrigated by rainwater collected from the roof, stored in an underground cistern and fed through a drip irrigation system. From a habitat perspective, the building imitates an escarpment. Installation, support systems, irrigation, replacement of modules and maintenance are included in the complete wall system. Living walls reduce the surface temperature of buildings by as much as 10 degrees C when covered with vegetation and a growing medium. The project team is anticipating LEED gold certification under the United States-Canada Green Building Council. It was concluded that this technology of vegetated building envelopes is applicable for acoustical control at airports, biofiltration of indoor air, greywater treatment, and urban agriculture and vertical

  7. Rare Earth Market Review

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Oversupply of rare earths led to the significant price drop of rare earth mineral products and separated products in Chinese domestic market. To stabilize the price, prevent waste of resources, further improve regulation capability on domestic rare earth market and rare earth price and maintain sustaining and healthy development of rare earth industry, partial rare earth producers in Baotou and Jiangxi province projected to cease the production for one month.

  8. International Divider Walls

    NARCIS (Netherlands)

    Kruis, A.; Sneller, A.C.W.(L.)

    2013-01-01

    The subject of this teaching case is the Enterprise Resource Planning (ERP) system implementation at International Divider Walls, the world market leader in design, production, and sales of divider walls. The implementation in one of the divisions of this multinational company had been successful, a

  9. Domain wall filters

    CERN Document Server

    Bär, O; Neuberger, H; Witzel, O; Baer, Oliver; Narayanan, Rajamani; Neuberger, Herbert; Witzel, Oliver

    2007-01-01

    We propose using the extra dimension separating the domain walls carrying lattice quarks of opposite handedness to gradually filter out the ultraviolet fluctuations of the gauge fields that are felt by the fermionic excitations living in the bulk. This generalization of the homogeneous domain wall construction has some theoretical features that seem nontrivial.

  10. Thin Wall Iron Castings

    Energy Technology Data Exchange (ETDEWEB)

    J.F. Cuttino; D.M. Stefanescu; T.S. Piwonka

    2001-10-31

    Results of an investigation made to develop methods of making iron castings having wall thicknesses as small as 2.5 mm in green sand molds are presented. It was found that thin wall ductile and compacted graphite iron castings can be made and have properties consistent with heavier castings. Green sand molding variables that affect casting dimensions were also identified.

  11. International Divider Walls

    NARCIS (Netherlands)

    Kruis, A.; Sneller, A.C.W.(L.)

    2013-01-01

    The subject of this teaching case is the Enterprise Resource Planning (ERP) system implementation at International Divider Walls, the world market leader in design, production, and sales of divider walls. The implementation in one of the divisions of this multinational company had been successful,

  12. The thermal performance of earth buildings

    Directory of Open Access Journals (Sweden)

    Heathcote, K.

    2011-09-01

    Full Text Available This paper examines the theoretical basis for the thermal performance of earth walls and links it to some test results on buildings constructed by the author, and to their predicted performance using a sophisticated computer modelling program. The analysis shows that for all earth walls the steady state thermal resistance is low but that for walls greater than about 450 mm thick the cyclic thermal resistance is high and increases exponentially. Whilst the steady state resistance of all thickness walls is low and results in higher than normal average temperatures in summer and lower than normal in winter the ability of thick earth walls to even out the swings in temperature is thought to be responsible for the materials reputation. The paper notes that good passive design principles (such as providing internal thermal mass and large areas of glazing for winter performance will greatly improve the performance of earth buildings with thin walls, but it is the author’s opinion that external earth walls should be at least 450 mm thick to gain the full benefit of thermal mass.

    Este artículo examina la base teórica del comportamiento térmico de las paredes de tierra y la relaciona con varios resultados de test realizados sobre edificios construidos por el autor, y con su comportamiento previsto utilizando un sofisticado programa de modelado por ordenador. El análisis muestra que la resistencia térmica constante es baja para todas las paredes de tierra, pero que para muros con un grosor mayor que 450 mm la resistencia térmica cíclica es alta y se incrementa exponencialmente. Mientras que la resistencia térmica constante de las paredes de cualquier grosor es baja y se traduce en temperaturas más altas que la media en verano y más bajas que la media en invierno, la capacidad de las paredes gruesas de tierra para amortiguar las variaciones de temperatura es la responsable de la reputación de los materiales. El artículo señala que los

  13. Hard and soft walls

    CERN Document Server

    Milton, Kimball A

    2011-01-01

    In a continuing effort to understand divergences which occur when quantum fields are confined by bounding surfaces, we investigate local energy densities (and the local energy-momentum tensor) in the vicinity of a wall. In this paper, attention is largely confined to a scalar field. If the wall is an infinite Dirichlet plane, well known volume and surface divergences are found, which are regulated by a temporal point-splitting parameter. If the wall is represented by a linear potential in one coordinate $z$, the divergences are softened. The case of a general wall, described by a potential of the form $z^\\alpha$ for $z>0$ is considered. If $\\alpha>2$, there are no surface divergences, which in any case vanish if the conformal stress tensor is employed. Divergences within the wall are also considered.

  14. Earth from Above

    Science.gov (United States)

    Stahley, Tom

    2006-01-01

    Google Earth is a free online software that provides a virtual view of Earth. Using Google Earth, students can view Earth by hovering over features and locations they preselect or by serendipitously exploring locations that catch their fascination. Going beyond hovering, they can swoop forward and even tilt images to make more detailed…

  15. Rare Earth Resolution

    Institute of Scientific and Technical Information of China (English)

    Mei Xinyu

    2012-01-01

    BEFORE the early 1970s, China had no rare earth exports, and the world rare earth market was dominated by the United States, Europe and Japan. In the 1970s, China began to enter the world rare earth market and its share has picked up sharply in the following decades. Today, having the monopoly over global rare earth production, China must improve the benefits from rare earth production, not only from producing individual rare earth products, but also from mastering the intensive processing of rare earth products.

  16. "I Climbed the Great Wall"

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    I finally climbed the Great Wall, A dream of my childhood; my heart is filled with pleasure at the indescribable beauty of the Wall. China’s ancient civilization is best documented by the grandeur of the Wall.

  17. Feasibility of Integrated Insulation in Rammed Earth

    Science.gov (United States)

    Stone, C.; Balintova, M.; Holub, M.

    2015-11-01

    Building Codes in Europe stipulate strict thermal performance criteria which any traditional rammed earth recipe cannot meet. This does not infer that the material itself is inferior; it has many other face saving attributes such as low embodied energy, high workability, sound insulation, fire resistance, aesthetics, high diffusivity and thermal accumulation properties. Integrated insulation is experimented with, to try achieve a 0.22 [W/(m2.K)] overall coefficient of heat transfer for walls required by 2015 Slovak standards, without using external insulation or using technologically complex interstitial insulation. This has the added aesthetic benefit of leaving the earth wall exposed to the external environment. Results evaluate the feasibility of this traditional approach.

  18. First Exploratory Study on the Ageing of Rammed Earth Material

    Directory of Open Access Journals (Sweden)

    Quoc-Bao Bui

    2014-12-01

    Full Text Available Rammed earth (RE is attracting renewed interest throughout the world thanks to its “green” characteristics in the context of sustainable building. In this study, the ageing effects on RE material are studied on the walls which have been constructed and exposed for 22 years to natural weathering. First, mechanical characteristics of the “old” walls were determined by two approaches: in-situ dynamic measurements on the walls; laboratory tests on specimens which had been cut from the walls. Then, the walls’ soil was recycled and reused for manufacturing of new specimens which represented the initial state. Comparison between the compressive strength, the Young modulus of the walls after 22 years on site and that of the initial state enables to assess the ageing of the studied walls.

  19. Advanced walling systems

    CSIR Research Space (South Africa)

    De Villiers, A

    2010-01-01

    Full Text Available The question addressed by this chapter is: How should advanced walling systems be planned, designed, built, refurbished, and end their useful lives, to classify as smart, sustainable, green or eco-building environments?...

  20. Effect of plastic soil on a retaining wall subjected to surcharge loading

    Directory of Open Access Journals (Sweden)

    Al-Juari Khawla

    2016-01-01

    Full Text Available The seasonal variation and climatic changes play a significant role that affects the stresses exerted on a retaining wall, and the state of stresses in the soil mass behind the wall especially for highly expansive soil. These stresses resulted in the wall moving either away or towards the soil. In this study, a laboratory physical model of the retaining wall formed of a box having (950×900×600 mm dimensions with one side representing the wall being developed. After the soil being laid out in the box in specified layers, specified conditions of saturation and normal stresses were applied. The wall is allowed to move horizontally in several distances (0.1, 0.2, 0.3, 0.6, 0.8, 1.0 , 2.0, 3.0 and 4.0 mm, and the stresses being measured, then the vertical loading was released. The main measured variables during the tests are; the active and passive earth pressures, vertical movement of the soil, total suction and time. Results showed that the lateral earth pressure along the depth of the wall largely decreased when wall moved away from the soil. Total suction was slightly affected during wall’s movement. At unloading stage, the lateral earth pressure decreased at the upper half of wall height, but increased at the other wall part. Total suction was increased at all depths during this stage.

  1. Conducting Wall Hall Thrusters

    Science.gov (United States)

    Goebel, Dan M.; Hofer, Richard R.; Mikellides, Ioannis G.; Katz, Ira; Polk, James E.; Dotson, Brandon

    2013-01-01

    A unique configuration of the magnetic field near the wall of Hall thrusters, called Magnetic Shielding, has recently demonstrated the ability to significantly reduce the erosion of the boron nitride (BN) walls and extend the life of Hall thrusters by orders of magnitude. The ability of magnetic shielding to minimize interactions between the plasma and the discharge chamber walls has for the first time enabled the replacement of insulating walls with conducting materials without loss in thruster performance. The boron nitride rings in the 6 kW H6 Hall thruster were replaced with graphite that self-biased to near the anode potential. The thruster efficiency remained over 60% (within two percent of the baseline BN configuration) with a small decrease in thrust and increase in Isp typical of magnetically shielded Hall thrusters. The graphite wall temperatures decreased significantly compared to both shielded and unshielded BN configurations, leading to the potential for higher power operation. Eliminating ceramic walls makes it simpler and less expensive to fabricate a thruster to survive launch loads, and the graphite discharge chamber radiates more efficiently which increases the power capability of the thruster compared to conventional Hall thruster designs.

  2. The Lifeworld Earth and a Modelled Earth

    Science.gov (United States)

    Juuti, Kalle

    2014-01-01

    The goal of this paper is to study the question of whether a phenomenological view of the Earth could be empirically endorsed. The phenomenological way of thinking considers the Earth as a material entity, but not as an object as viewed in science. In the learning science tradition, tracking the process of the conceptual change of the shape of the…

  3. The Lifeworld Earth and a Modelled Earth

    Science.gov (United States)

    Juuti, Kalle

    2014-01-01

    The goal of this paper is to study the question of whether a phenomenological view of the Earth could be empirically endorsed. The phenomenological way of thinking considers the Earth as a material entity, but not as an object as viewed in science. In the learning science tradition, tracking the process of the conceptual change of the shape of the…

  4. Silica hollow spheres with nano-macroholes like diatomaceous earth.

    Science.gov (United States)

    Fujiwara, Masahiro; Shiokawa, Kumi; Sakakura, Ikuko; Nakahara, Yoshiko

    2006-12-01

    Artificial synthesis of hollow cell walls of diatoms is an ultimate target of nanomaterial science. The addition of some water-soluble polymers such as sodium polymethacrylate to a solution of water/oil/water emulsion system, which is an essential step of the simple synthetic procedure of silica hollow spheres (microcapsules), led to the formation of silica hollow spheres with nano-macroholes (>100 nm) in their shell walls, the morphologies of which are analogous to those of diatom earth.

  5. EarthKAM

    Data.gov (United States)

    National Aeronautics and Space Administration — Sponsored by NASA, EarthKAM (Earth Knowledge Acquired by Middle School Students) is an educational outreach program allowing middle school students to take pictures...

  6. Earth on the Move.

    Science.gov (United States)

    Naturescope, 1987

    1987-01-01

    Provides background information on the layers of the earth, the relationship between changes on the surface of the earth and its insides, and plate tectonics. Teaching activities are included, with some containing reproducible worksheets and handouts to accompany them. (TW)

  7. NASA Earth Exchange (NEX)

    Data.gov (United States)

    National Aeronautics and Space Administration — The NASA Earth Exchange (NEX) represents a new platform for the Earth science community that provides a mechanism for scientific collaboration and knowledge sharing....

  8. Where are the Walls?

    CERN Document Server

    Olive, Keith A; Peterson, Adam J

    2012-01-01

    The reported spatial variation in the fine-structure constant at high redshift, if physical, could be due to the presence of dilatonic domains, and one or more domain walls inside our horizon. An absorption spectrum of an object in a different domain from our own would be characterized by a different value of alpha. We show that while a single wall solution is statically comparable to a dipole fit, and is a big improvement over a weighted mean (despite adding 3 parameters), a two-wall solution is a far better fit (despite adding 3 parameters over the single wall solution). We derive a simple model accounting for the two-domain wall solution. The goodness of these fits is however dependent on the extra random error which was argued to account for the large scatter in most of the data. When this error is omitted, all the above solutions are poor fits to the data. When included, the solutions that exhibit a spatial dependence agree with the data much more significantly than the Standard Model; however, the Stand...

  9. Rammed earth construction: effect of the relative humidity on the stability and resistance of earth wall

    OpenAIRE

    Palazón Juncos, Lucía

    2016-01-01

    El objetivo del proyecto es analizar la influencia de la humedad relativa en la estabilidad y resistencia de una estructura construida con tierra compactada. Esta técnica consiste en compactar sucesivas capas de suelo dentro de un molde. La compactación puede ser manual o bien, mecánica. Como es sabido, esta técnica requiere una cuidadosa ejecución debido a la fuerte influencia de las condiciones climáticas en las prestaciones de la construcción, debido a que la transferencia de la humeda...

  10. Mouse bladder wall injection.

    Science.gov (United States)

    Fu, Chi-Ling; Apelo, Charity A; Torres, Baldemar; Thai, Kim H; Hsieh, Michael H

    2011-07-12

    Mouse bladder wall injection is a useful technique to orthotopically study bladder phenomena, including stem cell, smooth muscle, and cancer biology. Before starting injections, the surgical area must be cleaned with soap and water and antiseptic solution. Surgical equipment must be sterilized before use and between each animal. Each mouse is placed under inhaled isoflurane anesthesia (2-5% for induction, 1-3% for maintenance) and its bladder exposed by making a midline abdominal incision with scissors. If the bladder is full, it is partially decompressed by gentle squeezing between two fingers. The cell suspension of interest is intramurally injected into the wall of the bladder dome using a 29 or 30 gauge needle and 1 cc or smaller syringe. The wound is then closed using wound clips and the mouse allowed to recover on a warming pad. Bladder wall injection is a delicate microsurgical technique that can be mastered with practice.

  11. Axion domain wall baryogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Daido, Ryuji; Kitajima, Naoya [Department of Physics, Tohoku University,Sendai 980-8578 (Japan); Takahashi, Fuminobu [Department of Physics, Tohoku University,Sendai 980-8578 (Japan); Kavli IPMU, TODIAS, University of Tokyo,Kashiwa 277-8583 (Japan)

    2015-07-28

    We propose a new scenario of baryogenesis, in which annihilation of axion domain walls generates a sizable baryon asymmetry. Successful baryogenesis is possible for a wide range of the axion mass and decay constant, m≃10{sup 8}–10{sup 13} GeV and f≃10{sup 13}–10{sup 16} GeV. Baryonic isocurvature perturbations are significantly suppressed in our model, in contrast to various spontaneous baryogenesis scenarios in the slow-roll regime. In particular, the axion domain wall baryogenesis is consistent with high-scale inflation which generates a large tensor-to-scalar ratio within the reach of future CMB B-mode experiments. We also discuss the gravitational waves produced by the domain wall annihilation and its implications for the future gravitational wave experiments.

  12. Capturing Near Earth Objects

    OpenAIRE

    Baoyin, Hexi; CHEN Yang; Li, Junfeng

    2011-01-01

    Recently, Near Earth Objects (NEOs) have been attracting great attention, and thousands of NEOs have been found to date. This paper examines the NEOs' orbital dynamics using the framework of an accurate solar system model and a Sun-Earth-NEO three-body system when the NEOs are close to Earth to search for NEOs with low-energy orbits. It is possible for such an NEO to be temporarily captured by Earth; its orbit would thereby be changed and it would become an Earth-orbiting object after a small...

  13. Congenital Abdominal Wall Defects

    DEFF Research Database (Denmark)

    Risby, Kirsten; Jakobsen, Marianne Skytte; Qvist, Niels

    2016-01-01

    complications were seen in five (15%) children: four had detachment of the mesh and one patient developed abdominal compartment syndrome. Mesh related clinical infection was observed in five children. In hospital mortality occurred in four cases (2 gastroschisis and 2 omphalocele) and was not procedure......OBJECTIVE: To evaluate the clinical utility of GORE® DUALMESH (GDM) in the staged closure of large congenital abdominal wall defects. MATERIALS AND METHODS: Data of patients with congenital abdominal wall defects managed with GDM was analyzed for outcome regarding complete fascial closure; mesh...

  14. Timber frame walls

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place; Brandt, Erik

    2010-01-01

    A ventilated cavity is usually considered good practice for removing moisture behind the cladding of timber framed walls. Timber frame walls with no cavity are a logical alternative as they are slimmer and less expensive to produce and besides the risk of a two-sided fire behind the cladding....... It was found that the specific damages made to the vapour barrier as part of the test did not have any provable effect on the moisture content. In general elements with an intact vapour barrier did not show a critical moisture content at the wind barrier after four years of exposure....

  15. A Report of Contemporary Rammed Earth Construction and Research in North America

    OpenAIRE

    Arno Schmidt; Bly Windstorm

    2013-01-01

    Contemporary stabilized rammed earth (SRE) draws upon traditional rammed earth (RE) methods and materials, often incorporating reinforcing steel and rigid insulation, enhancing the structural and energy performance of the walls while satisfying building codes. SRE structures are typically engineered by licensed Structural Engineers using the Concrete Building Code or the Masonry Building Code. The construction process of SRE creates structural walls of relatively high compressive strength app...

  16. Geochemistry of Rare Earth Elements in Aktishikan Gold Deposit, Xinjiang

    Institute of Scientific and Technical Information of China (English)

    袁峰; 周涛发; 岳书仓

    2002-01-01

    The characteristics and the models of rare earth elements in the geolo gical bodies and the hydrothermal water balanced with the adamellite were compre h ensively studied in Aktishikan gold deposit,Nurt area of Altay,Xinjiang.And th e behavior of rare earth elements during metasomatic alteration was discussed by using the isocon method of Grant.The results show that the rare earth elements a re inert during metasomatic alteration,the hydrothermal water has no relation t o the magmatic water,and the gold material sources mainly stem from the wall rock.

  17. Moisture Research - Optimizing Wall Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Arena, Lois [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Mantha, Pallavi [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States)

    2013-05-01

    In this project, the Consortium for Advanced Residential Buildings (CARB) team evaluated several different configurations of wall assemblies to determine the accuracy of moisture modeling and make recommendations to ensure durable, efficient assemblies. WUFI and THERM were used to model the hygrothermal and heat transfer characteristics of these walls. Wall assemblies evaluated included code minimum walls using spray foam insulation and fiberglass batts, high R-value walls at least 12 in. thick (R-40 and R-60 assemblies), and brick walls with interior insulation.

  18. The Earth's Magnetic Field

    OpenAIRE

    Edda Lína Gunnarsdóttir 1988

    2012-01-01

    The Earth's magnetic field is essential for life on Earth, as we know it, to exist. It forms a magnetic shield around the planet, protecting it from high energy particles and radiation from the Sun, which can cause damage to life, power systems, orbiting satellites, astronauts and spacecrafts. This report contains a general overview of the Earth's magnetic field. The different sources that contribute to the total magnetic field are presented and the diverse variations in the field are describ...

  19. Uderstanding Snowball Earth Deglaciation

    Science.gov (United States)

    Abbot, D. S.

    2012-12-01

    Earth, a normally clement planet comfortably in its star's habitable zone, suffered global or nearly global glaciation at least twice during the Neoproterozoic era (at about 635 and 710 million years ago). Viewed in the context of planetary evolution, these pan-global glaciations (Snowball Earth events) were extremely rapid, lasting only a few million years. The dramatic effect of the Snowball Earth events on the development of the planet can be seen through their link to rises in atmospheric oxygen and evolutionary innovations. These potential catastrophes on an otherwise clement planet can be used to gain insight into planetary habitability more generally. Since Earth is not currently a Snowball, a sound deglaciation mechanism is crucial for the viability of the Snowball Earth hypothesis. The traditional deglaciation mechanism is a massive build up of CO2 due to reduced weathering during Snowball Earth events until tropical surface temperatures reach the melting point. Once initiated, such a deglaciation might happen on a timescale of only dozens of thousands of years and would thrust Earth from the coldest climate in its history to the warmest. Therefore embedded in Snowball Earth events is an even more rapid and dramatic environmental change. Early global climate model simulations raised doubt about whether Snowball Earth deglaciation could be achieved at a CO2 concentration low enough to be consistent with geochemical data, which represented a potential challenge to the Snowball Earth hypothesis. Over the past few years dust and clouds have emerged as the essential missing additional processes that would allow Snowball Earth deglaciation at a low enough CO2 concentration. I will discuss the dust and cloud mechanisms and the modeling behind these ideas. This effort is critical for the broader implications of Snowball Earth events because understanding the specific deglaciation mechanism determines whether similar processes could happen on other planets.

  20. High-R Walls for Remodeling: Wall Cavity Moisture Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Wiehagen, J.; Kochkin, V.

    2012-12-01

    The focus of the study is on the performance of wall systems, and in particular, the moisture characteristics inside the wall cavity and in the wood sheathing. Furthermore, while this research will initially address new home construction, the goal is to address potential moisture issues in wall cavities of existing homes when insulation and air sealing improvements are made.

  1. High-R Walls for Remodeling. Wall Cavity Moisture Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Wiehagen, J. [NAHB Research Center Industry Partnership, Upper Marlboro, MD (United States); Kochkin, V. [NAHB Research Center Industry Partnership, Upper Marlboro, MD (United States)

    2012-12-01

    The focus of the study is on the performance of wall systems, and in particular, the moisture characteristics inside the wall cavity and in the wood sheathing. Furthermore, while this research will initially address new home construction, the goal is to address potential moisture issues in wall cavities of existing homes when insulation and air sealing improvements are made.

  2. The Earth's early evolution.

    Science.gov (United States)

    Bowring, S A; Housh, T

    1995-09-15

    The Archean crust contains direct geochemical information of the Earth's early planetary differentiation. A major outstanding question in the Earth sciences is whether the volume of continental crust today represents nearly all that formed over Earth's history or whether its rates of creation and destruction have been approximately balanced since the Archean. Analysis of neodymium isotopic data from the oldest remnants of Archean crust suggests that crustal recycling is important and that preserved continental crust comprises fragments of crust that escaped recycling. Furthermore, the data suggest that the isotopic evolution of Earth's mantle reflects progressive eradication of primordial heterogeneities related to early differentiation.

  3. Near Earth Objects

    DEFF Research Database (Denmark)

    Wolff, Stefan

    2006-01-01

    , Near Earth Objects: Asteroids and comets following paths that bring them near the Earth. NEOs have collided with the Earth since its formation, some causing local devastation, some causing global climate changes, yet the threat from a collision with a near Earth object has only recently been recognised...... of starlight by the Sun, and therefore directly observe the structure of space-time. This thesis explores several aspects of the observation of NEOs with Gaia, emphasising detection of NEOs and the quality of orbits computed from Gaia observations. The main contribution is the work on motion detection...

  4. Capturing near-Earth asteroids around Earth

    Science.gov (United States)

    Hasnain, Zaki; Lamb, Christopher A.; Ross, Shane D.

    2012-12-01

    The list of detected near-Earth asteroids (NEAs) is constantly growing. NEAs are likely targets for resources to support space industrialization, as they may be the least expensive source of certain needed raw materials. The limited supply of precious metals and semiconducting elements on Earth may be supplemented or even replaced by the reserves floating in the form of asteroids around the solar system. Precious metals make up a significant fraction NEAs by mass, and even one metallic asteroid of ˜1km size and fair enrichment in platinum-group metals would contain twice the tonnage of such metals already harvested on Earth. There are ˜1000 NEAs with a diameter of greater than 1 km. Capturing these asteroids around the Earth would expand the mining industry into an entirely new dimension. Having such resources within easy reach in Earth's orbit could provide an off-world environmentally friendly remedy for impending terrestrial shortages, especially given the need for raw materials in developing nations. In this paper, we develop and implement a conceptually simple algorithm to determine trajectory characteristics necessary to move NEAs into capture orbits around the Earth. Altered trajectories of asteroids are calculated using an ephemeris model. Only asteroids of eccentricity less than 0.1 have been studied and the model is restricted to the ecliptic plane for simplicity. We constrain the time of retrieval to be 10 years or less, based on considerations of the time to return on investment. For the heliocentric phase, constant acceleration is assumed. The acceleration required for transporting these asteroids from their undisturbed orbits to the sphere of influence of the Earth is the primary output, along with the impulse or acceleration necessary to effect capture to a bound orbit once the Earth's sphere of influence is reached. The initial guess for the constant acceleration is provided by a new estimation method, similar in spirit to Edelbaum's. Based on the

  5. Occupy Wall Street

    DEFF Research Database (Denmark)

    Jensen, Michael J.; Bang, Henrik

    2013-01-01

    This article analyzes the political form of Occupy Wall Street on Twitter. Drawing on evidence contained within the profiles of over 50,000 Twitter users, political identities of participants are characterized using natural language processing. The results find evidence of a traditional oppositio......This article analyzes the political form of Occupy Wall Street on Twitter. Drawing on evidence contained within the profiles of over 50,000 Twitter users, political identities of participants are characterized using natural language processing. The results find evidence of a traditional...... oppositional social movement alongside a legitimizing countermovement, but also a new notion of political community as an ensemble of discursive practices that are endogenous to the constitution of political regimes from the “inside out.” These new political identities are bound by thin ties of political...

  6. Timber frame walls

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place; Brandt, Erik

    2010-01-01

    A ventilated cavity is usually considered good practice for removing moisture behind the cladding of timber framed walls. Timber frame walls with no cavity are a logical alternative as they are slimmer and less expensive to produce and besides the risk of a two-sided fire behind the cladding...... were removed in some of the elements to simulate damaged vapour barriers. The condition of the wind barriers of elements with intact vapour barriers was inspected from the inside after four years of exposure. This paper presents results with emphasis on the moisture conditions behind the wind barrier....... It was found that the specific damages made to the vapour barrier as part of the test did not have any provable effect on the moisture content. In general elements with an intact vapour barrier did not show a critical moisture content at the wind barrier after four years of exposure....

  7. Space, composition, vertical wall ...

    OpenAIRE

    Despot, Katerina; Sandeva, Vaska

    2016-01-01

    The space in which it is an integral segment of our life is nourished with many functional and decorative elements. One aspect for consideration of vertical walls or The vertical gardens and their aesthetic impact in space called function. Vertical gardens bordering the decoration to totally functional garden in areas where there is little oxygen and space, ideal for residential buildings and public spaces where missing greenery, special place occupies in interior design where their expres...

  8. Scalable Resolution Display Walls

    KAUST Repository

    Leigh, Jason

    2013-01-01

    This article will describe the progress since 2000 on research and development in 2-D and 3-D scalable resolution display walls that are built from tiling individual lower resolution flat panel displays. The article will describe approaches and trends in display hardware construction, middleware architecture, and user-interaction design. The article will also highlight examples of use cases and the benefits the technology has brought to their respective disciplines. © 1963-2012 IEEE.

  9. Wall Street som kreationistisk forkynder

    DEFF Research Database (Denmark)

    Ekman, Susanne

    2016-01-01

    Artiklen gennemgår Karen Hos etnografi om Wall Street: "Liquidated: An ethnography of Wall Street" set i lyset af den offentlige debat vedrørende Goldman Sachs opkøb af Dong......Artiklen gennemgår Karen Hos etnografi om Wall Street: "Liquidated: An ethnography of Wall Street" set i lyset af den offentlige debat vedrørende Goldman Sachs opkøb af Dong...

  10. Light shining through walls

    Energy Technology Data Exchange (ETDEWEB)

    Redondo, Javier [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Max-Planck-Institut fuer Physik, Muenchen (Germany); Ringwald, Andreas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2010-11-15

    Shining light through walls? At first glance this sounds crazy. However, very feeble gravitational and electroweak effects allow for this exotic possibility. Unfortunately, with present and near future technologies the opportunity to observe light shining through walls via these effects is completely out of question. Nevertheless there are quite a number of experimental collaborations around the globe involved in this quest. Why are they doing it? Are there additional ways of sending photons through opaque matter? Indeed, various extensions of the standard model of particle physics predict the existence of new particles called WISPs - extremely weakly interacting slim particles. Photons can convert into these hypothetical particles, which have no problems to penetrate very dense materials, and these can reconvert into photons after their passage - as if light was effectively traversing walls. We review this exciting field of research, describing the most important WISPs, the present and future experiments, the indirect hints from astrophysics and cosmology pointing to the existence of WISPs, and finally outlining the consequences that the discovery of WISPs would have. (orig.)

  11. Molded Concrete Center Mine Wall

    Science.gov (United States)

    Lewis, E. V.

    1987-01-01

    Proposed semiautomatic system forms concrete-foam wall along middle of coal-mine passage. Wall helps support roof and divides passage into two conduits needed for ventilation of coal face. Mobile mold and concrete-foam generator form sections of wall in place.

  12. Cell Wall Biology: Perspectives from Cell Wall Imaging

    Institute of Scientific and Technical Information of China (English)

    Kieran J.D.Lee; Susan E.Marcus; J.Paul Knox

    2011-01-01

    Polysaccharide-rich plant cell walls are important biomaterials that underpin plant growth,are major repositories for photosynthetically accumulated carbon,and,in addition,impact greatly on the human use of plants. Land plant cell walls contain in the region of a dozen major polysaccharide structures that are mostly encompassed by cellulose,hemicelluloses,and pectic polysaccharides. During the evolution of land plants,polysaccharide diversification appears to have largely involved structural elaboration and diversification within these polysaccharide groups. Cell wall chemistry is well advanced and a current phase of cell wall science is aimed at placing the complex polysaccharide chemistry in cellular contexts and developing a detailed understanding of cell wall biology. Imaging cell wall glycomes is a challenging area but recent developments in the establishment of cell wall molecular probe panels and their use in high throughput procedures are leading to rapid advances in the molecular understanding of the spatial heterogeneity of individual cell walls and also cell wall differences at taxonomic levels. The challenge now is to integrate this knowledge of cell wall heterogeneity with an understanding of the molecular and physiological mechanisms that underpin cell wall properties and functions.

  13. Canal Wall Reconstruction Mastoidectomy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective To investigate the advantages of canal wall reconstruction (CWR) mastoidectomy, a single-stage technique for cholesteatoma removal and posterior external canal wall reconstruction, over the open and closed procedures in terms of cholesteatoma recurrence. Methods: Between June 2002 and December 2005, 38 patients (40 ears) with cholesteatoma were admited to Sun Yat-Sen Memorial Hospital and received surgical treatments. Of these patients, 25 were male with ages ranging between 11 and 60 years (mean = 31.6 years) and 13 were female with ages ranging between 20 and 65 years (mean = 38.8 years). Canal wall reconstruction (CWR)mastoidectomy was performed in 31 ears and canal wall down (CWD) mastoidectomy in 9 ears. Concha cartilage was used for ear canal wall reconstruction in 22 of the 31 CWR procedures and cortical mastoid bone was used in the remaining 9 cases. Results At 0.5 to 4 years follow up, all but one patients remained free of signs of cholesteatoma recurrence, i.e., no retraction pocket or cholesteatoma matrix. One patient, a smoker, needed revision surgery due to cholesteatoma recurrence 1.5 year after the initial operation. The recurrence rate was therefore 3.2% (1/31). Cholesteatoma recurrence was monitored using postoperative CT scans whenever possible. In the case that needed a revision procedure, a retraction pocket was identified by otoendoscopy in the pars flacida area that eventually evolved into a cholesteatoma. A pocket extending to the epitympanum filled with cholesteatoma matrix was confirmed during the revision operation, A decision to perform a modified mastoidectomy was made as the patient refused to quit smoking. The mean air-bone gap in pure tone threshold was 45 dB before surgery and 25 dB after (p < 0.05). There was no difference between using concha cartilage and cortical mastoid bone for the reconstruction regarding air-bone gap improvement, CT findings and otoendoscopic results. Conclusion CWR mastoidectomy can be used for

  14. Introducing Earth's Orbital Eccentricity

    Science.gov (United States)

    Oostra, Benjamin

    2015-01-01

    Most students know that planetary orbits, including Earth's, are elliptical; that is Kepler's first law, and it is found in many science textbooks. But quite a few are mistaken about the details, thinking that the orbit is very eccentric, or that this effect is somehow responsible for the seasons. In fact, the Earth's orbital eccentricity is…

  15. The Earth's Core.

    Science.gov (United States)

    Jeanloz, Raymond

    1983-01-01

    The nature of the earth's core is described. Indirect evidence (such as that determined from seismological data) indicates that it is an iron alloy, solid toward its center but otherwise liquid. Evidence also suggests that it is the turbulent flow of the liquid that generates the earth's magnetic field. (JN)

  16. Left ventricular wall stress compendium.

    Science.gov (United States)

    Zhong, L; Ghista, D N; Tan, R S

    2012-01-01

    Left ventricular (LV) wall stress has intrigued scientists and cardiologists since the time of Lame and Laplace in 1800s. The left ventricle is an intriguing organ structure, whose intrinsic design enables it to fill and contract. The development of wall stress is intriguing to cardiologists and biomedical engineers. The role of left ventricle wall stress in cardiac perfusion and pumping as well as in cardiac pathophysiology is a relatively unexplored phenomenon. But even for us to assess this role, we first need accurate determination of in vivo wall stress. However, at this point, 150 years after Lame estimated left ventricle wall stress using the elasticity theory, we are still in the exploratory stage of (i) developing left ventricle models that properly represent left ventricle anatomy and physiology and (ii) obtaining data on left ventricle dynamics. In this paper, we are responding to the need for a comprehensive survey of left ventricle wall stress models, their mechanics, stress computation and results. We have provided herein a compendium of major type of wall stress models: thin-wall models based on the Laplace law, thick-wall shell models, elasticity theory model, thick-wall large deformation models and finite element models. We have compared the mean stress values of these models as well as the variation of stress across the wall. All of the thin-wall and thick-wall shell models are based on idealised ellipsoidal and spherical geometries. However, the elasticity model's shape can vary through the cycle, to simulate the more ellipsoidal shape of the left ventricle in the systolic phase. The finite element models have more representative geometries, but are generally based on animal data, which limits their medical relevance. This paper can enable readers to obtain a comprehensive perspective of left ventricle wall stress models, of how to employ them to determine wall stresses, and be cognizant of the assumptions involved in the use of specific models.

  17. Solid Earth: Introduction

    Science.gov (United States)

    Rummel, R.

    1991-10-01

    The principles of the solid Earth program are introduced. When considering the study of solid Earth from space, satellites are used as beacons, inertial references, free fall probes and carrying platforms. The phenomenon measured by these satellites and the processes which can be studied as a result of these measurements are tabulated. The NASA solid Earth program focusses on research into surface kinematics, Earth rotation, land, ice, and ocean monitoring. The ESA solid Earth program identifies as its priority the Aristoteles mission for determining the gravity and magnetic field globally, with high spatial resolution and high accuracy. The Aristoteles mission characteristics and goals are listed. The benefits of the improved gravity information that will be provided by this mission are highlighted. This information will help in the following research: geodesy, orbit mechanics, geodynamics, oceanography, climate sea level, and the atmosphere.

  18. Strengthening of Shear Walls

    DEFF Research Database (Denmark)

    Hansen, Christian Skodborg

    -plane loaded walls and disks is however not included in any guidelines, and only a small fraction of scientists have initiated research within this topic. Furthermore, studies of the principal behavior and response of a strengthened disk has not yet been investigated satisfactorily, and this is the principal...... be altered to fit the surrounding boundary conditions. The effective cohesive law will then become a function of the investigated structural geometry. A simplified approach for the latter topic was used to predict the load capacity of concrete beams in shear. Results obtained were acceptable, but the model...

  19. Axions from wall decay

    Energy Technology Data Exchange (ETDEWEB)

    Chang, S; Hagmann, C; Sikivie, P

    2001-01-08

    The authors discuss the decay of axion walls bounded by strings and present numerical simulations of the decay process. In these simulations, the decay happens immediately, in a time scale of order the light travel time, and the average energy of the radiated axions is {approx_equal} 7m{sub a} for v{sub a}/m{sub a} {approx_equal} 500. is found to increase approximately linearly with ln(v{sub a}/m{sub a}). Extrapolation of this behavior yields {approx_equal} 60 m{sub a} in axion models of interest.

  20. Abdominal wall endometriosis.

    Science.gov (United States)

    Upadhyaya, P; Karak, A K; Sinha, A K; Kumar, B; Karki, S; Agarwal, C S

    2010-01-01

    Endometriosis of abdominal wall scar following operation on uterus and tubes is extremely rare. The late onset of symptoms after surgery is the usual cause of misdiagnosis. Scar endometriosis is a rare disease which is difficult to diagnose and should always be considered as a differential diagnosis of painful abdominal masses in women. The diagnosis is made only after excision and histopathology of the lesion. Preoperative differentials include hernia, lipoma, suture granuloma or abscess. Hence an awareness of the entity avoids delay in diagnosis, helps clinicians to a more tailored treatment and also avoids unnecessary referrals. We report a case of abdominal endometriosis. The definitive diagnosis of which was established by histopathological studies.

  1. Earth as art three

    Science.gov (United States)

    ,

    2010-01-01

    For most of us, deserts, mountains, river valleys, coastlines even dry lakebeds are relatively familiar features of the Earth's terrestrial environment. For earth scientists, they are the focus of considerable scientific research. Viewed from a unique and unconventional perspective, Earth's geographic attributes can also be a surprising source of awe-inspiring art. That unique perspective is space. The artists for the Earth as Art Three exhibit are the Landsat 5 and Landsat 7 satellites, which orbit approximately 705 kilometers (438 miles) above the Earth's surface. While studying the images these satellites beam down daily, researchers are often struck by the sheer beauty of the scenes. Such images inspire the imagination and go beyond scientific value to remind us how stunning, intricate, and simply amazing our planet's features can be. Instead of paint, the medium for these works of art is light. But Landsat satellite sensors don't see light as human eyes do; instead, they see radiant energy reflected from Earth's surface in certain wavelengths, or bands, of red, green, blue, and infrared light. When these different bands are combined into a single image, remarkable patterns, colors, and shapes emerge. The Earth as Art Three exhibit provides fresh and inspiring glimpses of different parts of our planet's complex surface. The images in this collection were chosen solely based on their aesthetic appeal. Many of the images have been manipulated to enhance color variations or details. They are not intended for scientific interpretation only for your viewing pleasure. Enjoy!

  2. Sun-Earth Days

    Science.gov (United States)

    Thieman, J.; Ng, C.; Lewis, E.; Cline, T.

    2010-08-01

    Sun-Earth Day is a well-coordinated series of programs, resources and events under a unique yearly theme highlighting the fundamentals of heliophysics research and missions. A menu of activities, conducted throughout the year, inspire and educate participants. Sun-Earth Day itself can vary in date, but usually is identified by a celebration on or near the spring equinox. Through the Sun-Earth Day framework we have been able to offer a series of coordinated events that promote and highlight the Sun, its connection to Earth and the other planets. Sun-Earth Day events are hosted by educators, museums, amateur astronomers and scientists and occur at schools, community groups, parks, planetaria and science centers around the globe. Sun-Earth Day raises the awareness and knowledge of formal and informal education audiences concerning space weather and heliophysics. By building on the success of Sun-Earth Day yearly celebrations, we seek to affect people of all backgrounds and ages with the wonders of heliophysics science, discovery, and exploration in ways that are both tangible and meaningful to their lives.

  3. Accretion of the Earth.

    Science.gov (United States)

    Canup, Robin M

    2008-11-28

    The origin of the Earth and its Moon has been the focus of an enormous body of research. In this paper I review some of the current models of terrestrial planet accretion, and discuss assumptions common to most works that may require re-examination. Density-wave interactions between growing planets and the gas nebula may help to explain the current near-circular orbits of the Earth and Venus, and may result in large-scale radial migration of proto-planetary embryos. Migration would weaken the link between the present locations of the planets and the original provenance of the material that formed them. Fragmentation can potentially lead to faster accretion and could also damp final planet orbital eccentricities. The Moon-forming impact is believed to be the final major event in the Earth's accretion. Successful simulations of lunar-forming impacts involve a differentiated impactor containing between 0.1 and 0.2 Earth masses, an impact angle near 45 degrees and an impact speed within 10 per cent of the Earth's escape velocity. All successful impacts-with or without pre-impact rotation-imply that the Moon formed primarily from material originating from the impactor rather than from the proto-Earth. This must ultimately be reconciled with compositional similarities between the Earth and the Moon.

  4. Earth Science Informatics - Overview

    Science.gov (United States)

    Ramapriyan, H. K.

    2017-01-01

    Over the last 10-15 years, significant advances have been made in information management, there are an increasing number of individuals entering the field of information management as it applies to Geoscience and Remote Sensing data, and the field of informatics has come to its own. Informatics is the science and technology of applying computers and computational methods to the systematic analysis, management, interchange, and representation of science data, information, and knowledge. Informatics also includes the use of computers and computational methods to support decision making and applications. Earth Science Informatics (ESI, a.k.a. geoinformatics) is the application of informatics in the Earth science domain. ESI is a rapidly developing discipline integrating computer science, information science, and Earth science. Major national and international research and infrastructure projects in ESI have been carried out or are on-going. Notable among these are: the Global Earth Observation System of Systems (GEOSS), the European Commissions INSPIRE, the U.S. NSDI and Geospatial One-Stop, the NASA EOSDIS, and the NSF DataONE, EarthCube and Cyberinfrastructure for Geoinformatics. More than 18 departments and agencies in the U.S. federal government have been active in Earth science informatics. All major space agencies in the world, have been involved in ESI research and application activities. In the United States, the Federation of Earth Science Information Partners (ESIP), whose membership includes over 180 organizations (government, academic and commercial) dedicated to managing, delivering and applying Earth science data, has been working on many ESI topics since 1998. The Committee on Earth Observation Satellites (CEOS)s Working Group on Information Systems and Services (WGISS) has been actively coordinating the ESI activities among the space agencies.

  5. Earth Science Informatics - Overview

    Science.gov (United States)

    Ramapriyan, H. K.

    2017-01-01

    Over the last 10-15 years, significant advances have been made in information management, there are an increasing number of individuals entering the field of information management as it applies to Geoscience and Remote Sensing data, and the field of informatics has come to its own. Informatics is the science and technology of applying computers and computational methods to the systematic analysis, management, interchange, and representation of science data, information, and knowledge. Informatics also includes the use of computers and computational methods to support decision making and applications. Earth Science Informatics (ESI, a.k.a. geoinformatics) is the application of informatics in the Earth science domain. ESI is a rapidly developing discipline integrating computer science, information science, and Earth science. Major national and international research and infrastructure projects in ESI have been carried out or are on-going. Notable among these are: the Global Earth Observation System of Systems (GEOSS), the European Commissions INSPIRE, the U.S. NSDI and Geospatial One-Stop, the NASA EOSDIS, and the NSF DataONE, EarthCube and Cyberinfrastructure for Geoinformatics. More than 18 departments and agencies in the U.S. federal government have been active in Earth science informatics. All major space agencies in the world, have been involved in ESI research and application activities. In the United States, the Federation of Earth Science Information Partners (ESIP), whose membership includes over 180 organizations (government, academic and commercial) dedicated to managing, delivering and applying Earth science data, has been working on many ESI topics since 1998. The Committee on Earth Observation Satellites (CEOS)s Working Group on Information Systems and Services (WGISS) has been actively coordinating the ESI activities among the space agencies.The talk will present an overview of current efforts in ESI, the role members of IEEE GRSS play, and discuss

  6. Earth before life.

    Science.gov (United States)

    Marzban, Caren; Viswanathan, Raju; Yurtsever, Ulvi

    2014-01-09

    A recent study argued, based on data on functional genome size of major phyla, that there is evidence life may have originated significantly prior to the formation of the Earth. Here a more refined regression analysis is performed in which 1) measurement error is systematically taken into account, and 2) interval estimates (e.g., confidence or prediction intervals) are produced. It is shown that such models for which the interval estimate for the time origin of the genome includes the age of the Earth are consistent with observed data. The appearance of life after the formation of the Earth is consistent with the data set under examination.

  7. Whole-Earth Decompression Dynamics

    OpenAIRE

    Herndon, J. Marvin

    2005-01-01

    The principles of Whole-Earth Decompression Dynamics are disclosed leading to a new way to interpret whole-Earth dynamics. Whole-Earth Decompression Dynamics incorporates elements of and unifies the two seemingly divergent dominant theories of continential displacement, plate tectonics theory and Earth expansion theory. Whole-Earth decompression is the consequence of Earth formation from within a Jupiter-like protoplanet with subsequent loss of gases and ices and concomitant rebounding. The i...

  8. Earth rotation and geodynamics

    Science.gov (United States)

    Bogusz, Janusz; Brzezinski, Aleksander; Kosek, Wieslaw; Nastula, Jolanta

    2015-12-01

    This paper presents the summary of research activities carried out in Poland in 2011-2014 in the field of Earth rotation and geodynamics by several Polish research institutions. It contains a summary of works on Earth rotation, including evaluation and prediction of its parameters and analysis of the related excitation data as well as research on associated geodynamic phenomena such as geocentre motion, global sea level change and hydrological processes. The second part of the paper deals with monitoring of geodynamic phenomena. It contains analysis of geodynamic networks of local, and regional scale using space (GNSS and SLR) techniques, Earth tides monitoring with gravimeters and water-tube hydrostatic clinometer, and the determination of secular variation of the Earth' magnetic field.

  9. Earth science: Extraordinary world

    Science.gov (United States)

    Day, James M. D.

    2016-09-01

    The isotopic compositions of objects that formed early in the evolution of the Solar System have been found to be similar to Earth's composition -- overturning notions of our planet's chemical distinctiveness. See Letters p.394 & p.399

  10. Gambling with the earth

    CERN Multimedia

    Muir, H

    2000-01-01

    The probability that dangerous Earth-devouring particles will be born at a new accelerator in the US may be tiny, but scientists have played down the devastating potential costs in their risk assessments according to a physicist (1 page).

  11. Astronomy: Earth's seven sisters

    Science.gov (United States)

    Snellen, Ignas A. G.

    2017-02-01

    Seven small planets whose surfaces could harbour liquid water have been spotted around a nearby dwarf star. If such a configuration is common in planetary systems, our Galaxy could be teeming with Earth-like planets. See Letter p.456

  12. Rare Earth Market Review

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ July 20~31 Rare earth market still went downward, which was mainly led by sluggish demand for didymium products. Weak demand by domestic NdFeB market was attributed to continuous price falling of didymium mischmetal.

  13. Analyzing earth's surface data

    Science.gov (United States)

    Barr, D. J.; Elifrits, C. D.

    1979-01-01

    Manual discusses simple inexpensive image analysis technique used to interpret photographs and scanner of data of Earth's surface. Manual is designed for those who have no need for sophisticated computer-automated analysis procedures.

  14. Managing Planet Earth.

    Science.gov (United States)

    Clark, William C.

    1989-01-01

    Discusses the human use of the planet earth. Describes the global patterns and the regional aspects of change. Four requirements for the cultivation of leadership and institutional competence are suggested. Lists five references for further reading. (YP)

  15. Earliest life on earth

    CERN Document Server

    Golding, Suzanne D

    2010-01-01

    This volume integrates the latest findings on earliest life forms, identified and characterized in some of the oldest rocks on Earth. It places emphasis on the integration of analytical methods with observational techniques and experimental simulations.

  16. Earth/Lands

    OpenAIRE

    2011-01-01

    Earth is an essentially original and misunderstood raw material with great potential, from the positive environmental and energy ratio, to its admirable capacity to integrate other materials such as stone, wood, brick, lime, vegetable fibres, etc., capable also of constituting the sole material for whole buildings in climactical and geographically extreme situations. Earth offers a great capacity to respond to the housing needs of millions of human beings, not only quantitative needs compa...

  17. Earth rotation and geodynamics

    OpenAIRE

    Bogusz Janusz; Brzezinski Aleksander; Kosek Wieslaw; Nastula Jolanta

    2015-01-01

    This paper presents the summary of research activities carried out in Poland in 2011-2014 in the field of Earth rotation and geodynamics by several Polish research institutions. It contains a summary of works on Earth rotation, including evaluation and prediction of its parameters and analysis of the related excitation data as well as research on associated geodynamic phenomena such as geocentre motion, global sea level change and hydrological processes. The second part of the paper deals wit...

  18. Abdominal wall blocks in adults

    DEFF Research Database (Denmark)

    Børglum, Jens; Gögenür, Ismail; Bendtsen, Thomas F

    2016-01-01

    Purpose of review Abdominal wall blocks in adults have evolved much during the last decade; that is, particularly with the introduction of ultrasound-guided (USG) blocks. This review highlights recent advances of block techniques within this field and proposes directions for future research.......  Recent findings Ultrasound guidance is now considered the golden standard for abdominal wall blocks in adults, even though some landmark-based blocks are still being investigated. The efficiency of USG transversus abdominis plane blocks in relation to many surgical procedures involving the abdominal wall...... been introduced with success. Future research should also investigate the effect of specific abdominal wall blocks on neuroendocrine and inflammatory stress response after surgery.  Summary USG abdominal wall blocks in adults are commonplace techniques today. Most abdominal wall blocks are assigned...

  19. Structure of axionic domain walls

    Science.gov (United States)

    Huang, M. C.; Sikivie, P.

    1985-09-01

    The structure of axionic domain walls is investigated using the low-energy effective theory of axions and pions. We derive the spatial dependence of the phases of the Peccei-Quinn scalar field and the QCD quark-antiquark condensates inside an axionic domain wall. Thence an accurate estimate of the wall surface energy density is obtained. The equations of motion for axions, photons, leptons, and baryons in the neighborhood of axionic domain walls are written down and estimates are given for the wall reflection and transmission coefficients of these particles. Finally, we discuss the energy dissipation by axionic domain walls oscillating in the early universe due to the reflection of particles in the primordial soup.

  20. Structure of axionic domain walls

    Energy Technology Data Exchange (ETDEWEB)

    Huang, M.C.; Sikivie, P.

    1985-09-15

    The structure of axionic domain walls is investigated using the low-energy effective theory of axions and pions. We derive the spatial dependence of the phases of the Peccei-Quinn scalar field and the QCD quark-antiquark condensates inside an axionic domain wall. Thence an accurate estimate of the wall surface energy density is obtained. The equations of motion for axions, photons, leptons, and baryons in the neighborhood of axionic domain walls are written down and estimates are given for the wall reflection and transmission coefficients of these particles. Finally, we discuss the energy dissipation by axionic domain walls oscillating in the early universe due to the reflection of particles in the primordial soup.

  1. Toward other Earths

    Science.gov (United States)

    Hatzes, Artie P.

    2016-04-01

    How common are habitable Earth-like planets? This is a key question that drives much of current research in exoplanets. To date, we have discovered over one thousand exoplanets, mostly through the transit method. Among these are Earth-size planets, but these orbit very close to the star (semi-major axis approximately 0.01 Astronomical Units). Potentially rocky planets have also been discovered in a star's habitable zone, but these have approximately twice the radius of the Earth. These certainly do not qualify as Earth "twins". Several hundreds of multi-planet systems have also been discovered, but these are mostly ultra-compact systems with up to seven planets all with orbital distances less than that of Mercury in our solar system. The detection of a planetary system that is the direct analog of our solar system still eludes us. After an overview of the current status of exoplanet discoveries I will discuss the prospects and challenges of finding such Earth analogs from the ground and from future space missions like PLATO. After over two decades of searching, we may well be on the brink of finding other Earths.

  2. Asymptotic Dynamics of Monopole Walls

    CERN Document Server

    Cross, R

    2015-01-01

    We determine the asymptotic dynamics of the U(N) doubly periodic BPS monopole in Yang-Mills-Higgs theory, called a monopole wall, by exploring its Higgs curve using the Newton polytope and amoeba. In particular, we show that the monopole wall splits into subwalls when any of its moduli become large. The long-distance gauge and Higgs field interactions of these subwalls are abelian, allowing us to derive an asymptotic metric for the monopole wall moduli space.

  3. Dynamical domain wall and localization

    Directory of Open Access Journals (Sweden)

    Yuta Toyozato

    2016-03-01

    Full Text Available Based on the previous works (Toyozato et al., 2013 [24]; Higuchi and Nojiri, 2014 [25], we investigate the localization of the fields on the dynamical domain wall, where the four-dimensional FRW universe is realized on the domain wall in the five-dimensional space–time. Especially we show that the chiral spinor can localize on the domain wall, which has not been succeeded in the past works as the seminal work in George et al. (2009 [23].

  4. An Analog Earth Climate Model

    Science.gov (United States)

    Varekamp, J. C.

    2010-12-01

    The earth climate is broadly governed by the radiative power of the sun as well as the heat retention and convective cooling of the atmosphere. I have constructed an analog earth model for an undergraduate climate class that simulates mean climate using these three parameters. The ‘earth’ is a hollow, black, bronze sphere (4 cm diameter) mounted on a thin insulated rod, and illuminated by two opposite optic fibers, with light focused on the sphere by a set of lenses. The sphere is encased in a large double-walled aluminum cylinder (34 cm diameter by 26 cm high) with separate water cooling jackets at the top, bottom, and sides. The cylinder can be filled with a gas of choice at a variety of pressures or can be run in vacuum. The exterior is cladded with insulation, and the temperature of the sphere, atmosphere and walls is monitored with thermocouples. The temperature and waterflow of the three cooling jackets can be monitored to establish the energy output of the whole system; the energy input is the energy yield of the two optic fibers. A small IR transmissive lens at the top provides the opportunity to hook up the fiber of a hyper spectrometer to monitor the emission spectrum of the black ‘earth’ sphere. A pressure gauge and gas inlet-outlet system for flushing of the cell completes it. The heat yield of the cooling water at the top is the sum of the radiative and convective components, whereas the bottom jacket only carries off the radiative heat of the sphere. Undergraduate E&ES students at Wesleyan University have run experiments with dry air, pure CO2, N2 and Ar at 1 atmosphere, and a low vacuum run was accomplished to calibrate the energy input. For each experiment, the lights are flipped on, the temperature acquisition routine is activated, and the sphere starts to warm up until an equilibrium temperature has been reached. The lights are then flipped off and the cooling sequence towards ambient is registered. The energy input is constant for a given

  5. The earth's hydrological cycle

    CERN Document Server

    Bonnet, R-M; Calisto, M; Destouni, G; Gurney, R; Johannessen, J; Kerr, Y; Lahoz, WA; Rast, M

    2014-01-01

    This book gives a comprehensive presentation of our present understanding of the Earth's Hydrological cycle and the problems, consequences and impacts that go with this topic. Water is a central component in the Earth's system. It is indispensable for life on Earth in its present form and influences virtually every aspect of our planet's life support system. On relatively short time scales, atmospheric water vapor interacts with the atmospheric circulation and is crucial in forming the Earth's climate zones. Water vapor is the most powerful of the greenhouse gases and serves to enhance the tropospheric temperature. The dominant part of available water on Earth resides in the oceans. Parts are locked up in the land ice on Greenland and Antarctica and a smaller part is estimated to exist as groundwater. If all the ice over the land and all the glaciers were to melt, the sea level would rise by some 80 m. In comparison, the total amount of water vapor in the atmosphere is small; it amounts to ~ 25 kg/m2, or the ...

  6. The Sun and Earth

    Science.gov (United States)

    Gopalswamy, Natchimuthuk

    2012-01-01

    Thus the Sun forms the basis for life on Earth via the black body radiation it emits. The Sun also emits mass in the form of the solar wind and the coronal mass ejections (CMEs). Mass emission also occurs in the form of solar energetic particles (SEPs), which happens during CMEs and solar flares. Both the mass and electromagnetic energy output of the Sun vary over a wide range of time scales, thus introducing disturbances on the space environment that extends from the Sun through the entire heliosphere including the magnetospheres and ionospheres of planets and moons of the solar system. Although our habitat is located in the neutral atmosphere of Earth, we are intimately connected to the non-neutral space environment starting from the ionosphere to the magnetosphere and to the vast interplanetary space. The variability of the solar mass emissions results in the interaction between the solar wind plasma and the magnetospheric plasma leading to huge disturbances in the geospace. The Sun ionizes our atmosphere and creates the ionosphere. The ionosphere can be severely disturbed by the transient energy input from solar flares and the solar wind during geomagnetic storms. The complex interplay between Earth's magnetic field and the solar magnetic field carried by the solar wind presents varying conditions that are both beneficial and hazardous to life on earth. This seminar presents some of the key aspects of this Sun-Earth connection that we have learned since the birth of space science as a scientific discipline some half a century ago.

  7. Modeling the earth system

    Energy Technology Data Exchange (ETDEWEB)

    Ojima, D. [ed.

    1992-12-31

    The 1990 Global Change Institute (GCI) on Earth System Modeling is the third of a series organized by the Office for Interdisciplinary Earth Studies to look in depth at particular issues critical to developing a better understanding of the earth system. The 1990 GCI on Earth System Modeling was organized around three themes: defining critical gaps in the knowledge of the earth system, developing simplified working models, and validating comprehensive system models. This book is divided into three sections that reflect these themes. Each section begins with a set of background papers offering a brief tutorial on the subject, followed by working group reports developed during the institute. These reports summarize the joint ideas and recommendations of the participants and bring to bear the interdisciplinary perspective that imbued the institute. Since the conclusion of the 1990 Global Change Institute, research programs, nationally and internationally, have moved forward to implement a number of the recommendations made at the institute, and many of the participants have maintained collegial interactions to develop research projects addressing the needs identified during the two weeks in Snowmass.

  8. Diplopia and orbital wall fractures

    NARCIS (Netherlands)

    Boffano, P.; Roccia, F.; Gallesio, C.; Karagozoglu, K.H.; Forouzanfar, T.

    2014-01-01

    Diplopia is a symptom that is frequently associated with orbital wall fractures. The aim of this article was to present the incidence and patterns of diplopia after orbital wall blow-out fractures in 2 European centers, Turin and Amsterdam, and to identify any correlation between this symptom and su

  9. Domain Walls in SU(5)

    CERN Document Server

    Poghosian, L E; Pogosian, Levon; Vachaspati, Tanmay

    2000-01-01

    We consider the Grand Unified SU(5) model with a small or vanishing cubic term in the adjoint scalar field in the potential. This gives the model an approximate or exact Z$_2$ symmetry whose breaking leads to domain walls. The simplest domain wall has the structure of a kink across which the Higgs field changes sign ($\\Phi \\to -\\Phi$) and inside which the full SU(5) is restored. The kink is shown to be perturbatively unstable for all parameters. We then construct a domain wall solution that is lighter than the kink and show it to be perturbatively stable for a range of parameters. The symmetry in the core of this domain wall is smaller than that outside. The interactions of the domain wall with magnetic monopole is discussed and it is shown that magnetic monopoles with certain internal space orientations relative to the wall pass through the domain wall. Magnetic monopoles in other relative internal space orientations are likely to be swept away on collision with the domain walls, suggesting a scenario where ...

  10. Solar Walls in tsbi3

    DEFF Research Database (Denmark)

    Wittchen, Kim Bjarne

    tsbi3 is a user-friendly and flexible computer program, which provides support to the design team in the analysis of the indoor climate and the energy performance of buildings. The solar wall module gives tsbi3 the capability of simulating solar walls and their interaction with the building. This...

  11. Control of Wall Mounting Robot

    DEFF Research Database (Denmark)

    Sloth, Christoffer; Pedersen, Rasmus

    2017-01-01

    This paper presents a method for designing controllers for trajectory tracking with actuator constraints. In particular, we consider a joystick-controlled wall mounting robot called WallMo. In contrast to previous works, a model-free approach is taken to the control problem, where the path...

  12. The "Brick Wall" Graphic Organizer

    Science.gov (United States)

    Matteson, Shirley M.

    2016-01-01

    A brick wall provides a fitting description of what happens when teachers try to teach a concept for which students are unprepared. When students are unsuccessful academically, their foundational knowledge may be missing, incomplete, or incorrect. As a result, students "hit a brick wall," and their academic progress stops because they do…

  13. Diplopia and orbital wall fractures

    NARCIS (Netherlands)

    Boffano, P.; Roccia, F.; Gallesio, C.; Karagozoglu, K.H.; Forouzanfar, T.

    2014-01-01

    Diplopia is a symptom that is frequently associated with orbital wall fractures. The aim of this article was to present the incidence and patterns of diplopia after orbital wall blow-out fractures in 2 European centers, Turin and Amsterdam, and to identify any correlation between this symptom and

  14. Moisture Research - Optimizing Wall Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Arena, L.; Mantha, P.

    2013-05-01

    The Consortium for Advanced Residential Buildings (CARB) evaluated several different configurations of wall assemblies to determine the accuracy of moisture modeling and make recommendations to ensure durable, efficient assemblies. WUFI and THERM were used to model the hygrothermal and heat transfer characteristics of these walls.

  15. Domain wall description of superconductivity

    CERN Document Server

    Brito, F A; Silva, J C M

    2012-01-01

    In the present work we shall address the issue of electrical conductivity in superconductors in the perspective of superconducting domain wall solutions in the realm of field theory. We take our set up made out of a dynamical complex scalar field coupled to gauge field to be responsible for superconductivity and an extra scalar real field that plays the role of superconducting domain walls. The temperature of the system is interpreted as the parameter to move type I to type II domain walls. Alternatively, this means that the domain wall surface is suffering an acceleration as one goes from one type to another. On the other hand, changing from type I to type II state means a formation of a condensate what is in perfect sense of lowering the temperature around the superconductor. One can think of this scenario as an analog of holographic scenarios where this set up is replaced by a black hole near the domain wall.

  16. Better Than Earth

    CERN Document Server

    Heller, René

    2015-01-01

    Do We Inhabit The Best O All Possible Worlds? German mathematician Gottfried Leibniz thought so, writing in 1710 that our planet, warts and all, must be the most optimal one imaginable. Leibniz's idea was roundly scorned as unscientific wishful thinking, most notably by French author Voltaire in his magnum opus, Candide. Yet Leibniz might find sympathy from at least one group of scientists - the astronomers who have for decades treated Earth as a golden standard as they search for worlds beyond our own solar system. Because earthlings still know of just one living world - our own - it makes some sense to use Earth as a template in the search for life elsewhere, such as in the most Earth-like regions of Mars or Jupiter's watery moon Europa. Now, however, discoveries of potentially habitable planets orbiting stars other than our sun - exoplanets, that is - are challenging that geocentric approach.

  17. Better Than Earth

    Science.gov (United States)

    Heller, René

    2015-01-01

    Do we inhabit the best of all possible worlds? German mathematician Gottfried Leibniz thought so, writing in 1710 that our planet, warts and all, must be the most optimal one imaginable. Leibniz's idea was roundly scorned as unscientific wishful thinking, most notably by French author Voltaire in his magnum opus, Candide. Yet Leibniz might find sympathy from at least one group of scientists - the astronomers who have for decades treated Earth as a golden standard as they search for worlds beyond our own solar system. Because earthlings still know of just one living world - our own - it makes some sense to use Earth as a template in the search for life elsewhere, such as in the most Earth-like regions of Mars or Jupiter's watery moon Europa. Now, however, discoveries of potentially habitable planets orbiting stars other than our sun - exoplanets, that is - are challenging that geocentric approach.

  18. Geoneutrino and Hydridic Earth model

    CERN Document Server

    Bezrukov, Leonid

    2013-01-01

    Uranium, Thorium and Potassium-40 abundances in the Earth were calculated in the frame of Hydridic Earth model. Terrestrial heat producton from U, Th and K40 decays was calculated also. We must admit the existance of Earth expansion process to understand the obtained large value of terrestrial heat producton. The geoneutrino detector with volume more than 5 kT (LENA type) must be constructed to definitely separate between Bulk Silicat Earth model and Hydridic Earth model.

  19. How Big is Earth?

    Science.gov (United States)

    Thurber, Bonnie B.

    2015-08-01

    How Big is Earth celebrates the Year of Light. Using only the sunlight striking the Earth and a wooden dowel, students meet each other and then measure the circumference of the earth. Eratosthenes did it over 2,000 years ago. In Cosmos, Carl Sagan shared the process by which Eratosthenes measured the angle of the shadow cast at local noon when sunlight strikes a stick positioned perpendicular to the ground. By comparing his measurement to another made a distance away, Eratosthenes was able to calculate the circumference of the earth. How Big is Earth provides an online learning environment where students do science the same way Eratosthenes did. A notable project in which this was done was The Eratosthenes Project, conducted in 2005 as part of the World Year of Physics; in fact, we will be drawing on the teacher's guide developed by that project.How Big Is Earth? expands on the Eratosthenes project by providing an online learning environment provided by the iCollaboratory, www.icollaboratory.org, where teachers and students from Sweden, China, Nepal, Russia, Morocco, and the United States collaborate, share data, and reflect on their learning of science and astronomy. They are sharing their information and discussing their ideas/brainstorming the solutions in a discussion forum. There is an ongoing database of student measurements and another database to collect data on both teacher and student learning from surveys, discussions, and self-reflection done online.We will share our research about the kinds of learning that takes place only in global collaborations.The entrance address for the iCollaboratory is http://www.icollaboratory.org.

  20. Channel Wall Landslides

    Science.gov (United States)

    2005-01-01

    [figure removed for brevity, see original site] The multiple landslides in this VIS image occur along a steep channel wall. Note the large impact crater in the context image. The formation of the crater may have initially weakened that area of the surface prior to channel formation. Image information: VIS instrument. Latitude -2.7, Longitude 324.8 East (35.2 West). 19 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  1. Alkaline earth metal thioindates

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov-Ehmin, B.N.; Ivlieva, V.I.; Filatenko, L.A.; Zajtsev, B.E.; Kaziev, G.Z.; Sarabiya, M.G.

    1984-08-01

    Alkaline earth metal thioindates of MIn/sub 2/S/sub 4/ composition were synthesized by interaction of alkaline earth metal oxoindates with hydrogen sulfide during heating. Investigation into the compounds by X-ray analysis showed that calcium compound crystallizes in cubic crystal system and strontium and barium compounds in rhombic crystal system. Lattice parameters and the number of formula units were determined. Thioindates of M/sub 3/In/sub 2/S/sub 6/ composition were synthesized, their individuality was shown.

  2. Rare (Earth Elements [score

    Directory of Open Access Journals (Sweden)

    Camilo Méndez

    2014-12-01

    Full Text Available Rare (Earth Elements is a cycle of works for solo piano. The cycle was inspired by James Dillon’s Book of Elements (Vol. I-V. The complete cycle will consist of 14 pieces; one for each selected rare (earth element. The chosen elements are Neodymium, Erbium, Tellurium, Hafnium, Tantalum, Technetium, Indium, Dysprosium, Lanthanium, Cerium, Europium, Terbium, Yttrium and Darmstadtium. These elements were selected due to their special atomic properties that in many cases make them extremely valuable for the development of new technologies, and also because of their scarcity. To date, only 4 works have been completed Yttrium, Technetium, Indium and Tellurium.

  3. Teaching earth science

    Science.gov (United States)

    Alpha, Tau Rho; Diggles, M.F.

    1998-01-01

    This CD-ROM contains 17 teaching tools: 16 interactive HyperCard 'stacks' and a printable model. They are separated into the following categories: Geologic Processes, Earthquakes and Faulting, and Map Projections and Globes. A 'navigation' stack, Earth Science, is provided as a 'launching' place from which to access all of the other stacks. You can also open the HyperCard Stacks folder and launch any of the 16 stacks yourself. In addition, a 17th tool, Earth and Tectonic Globes, is provided as a printable document. Each of the tools can be copied onto a 1.4-MB floppy disk and distributed freely.

  4. Quantizing Earth surface deformations

    Directory of Open Access Journals (Sweden)

    C. O. Bowin

    2015-03-01

    Full Text Available The global analysis of Bowin (2010 used the global 14 absolute Euler pole set (62 Myr history from Gripp and Gordon (1990 and demonstrated that plate tectonics conserves angular momentum. We herein extend that analysis using the more detailed Bird (2003 52 present-day Euler pole set (relative to a fixed Pacific plate for the Earth's surface, after conversion to absolute Euler poles. Additionally, new analytical results now provide new details on upper mantle mass anomalies in the outer 200 km of the Earth, as well as an initial quantizing of surface deformations.

  5. IR and the Earth

    DEFF Research Database (Denmark)

    Corry, Olaf; Stevenson, Hayley

    2017-01-01

    , in the end, one finite interconnected space. Together these two starting points make for the basic conundrum of Inter- national Relations and the Earth: how does a divided world live on a single globe? This introduction first provides an overview of the recent rise of ‘the environment’ in international......, ‘what has the environment ever done for IR?’, before the plan for the rest of the book sketches the content and direction of the ensuing chapters that explore the problematique of International Relations and the Earth....

  6. Wall Shear Stress, Wall Pressure and Near Wall Velocity Field Relationships in a Whirling Annular Seal

    Science.gov (United States)

    Morrison, Gerald L.; Winslow, Robert B.; Thames, H. Davis, III

    1996-01-01

    The mean and phase averaged pressure and wall shear stress distributions were measured on the stator wall of a 50% eccentric annular seal which was whirling in a circular orbit at the same speed as the shaft rotation. The shear stresses were measured using flush mounted hot-film probes. Four different operating conditions were considered consisting of Reynolds numbers of 12,000 and 24,000 and Taylor numbers of 3,300 and 6,600. At each of the operating conditions the axial distribution (from Z/L = -0.2 to 1.2) of the mean pressure, shear stress magnitude, and shear stress direction on the stator wall were measured. Also measured were the phase averaged pressure and shear stress. These data were combined to calculate the force distributions along the seal length. Integration of the force distributions result in the net forces and moments generated by the pressure and shear stresses. The flow field inside the seal operating at a Reynolds number of 24,000 and a Taylor number of 6,600 has been measured using a 3-D laser Doppler anemometer system. Phase averaged wall pressure and wall shear stress are presented along with phase averaged mean velocity and turbulence kinetic energy distributions located 0.16c from the stator wall where c is the seal clearance. The relationships between the velocity, turbulence, wall pressure and wall shear stress are very complex and do not follow simple bulk flow predictions.

  7. Bioreactor rotating wall vessel

    Science.gov (United States)

    2001-01-01

    The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators. Cell constructs grown in a rotating bioreactor on Earth (left) eventually become too large to stay suspended in the nutrient media. In the microgravity of orbit, the cells stay suspended. Rotation then is needed for gentle stirring to replenish the media around the cells.

  8. Bioreactor rotating wall vessel

    Science.gov (United States)

    2001-01-01

    The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators. Cell constructs grown in a rotating bioreactor on Earth (left) eventually become too large to stay suspended in the nutrient media. In the microgravity of orbit, the cells stay suspended. Rotation then is needed for gentle stirring to replenish the media around the cells.

  9. Diplopia and orbital wall fractures.

    Science.gov (United States)

    Boffano, Paolo; Roccia, Fabio; Gallesio, Cesare; Karagozoglu, K Hakki; Forouzanfar, Tymour

    2014-01-01

    Diplopia is a symptom that is frequently associated with orbital wall fractures. The aim of this article was to present the incidence and patterns of diplopia after orbital wall blow-out fractures in 2 European centers, Turin and Amsterdam, and to identify any correlation between this symptom and such fractures. This study is based on 2 databases that have continuously recorded data of patients hospitalized with maxillofacial fractures between 2001 and 2010. On the whole, 447 patients (334 males, 113 females) with pure blow-out orbital wall fractures were included. The most frequently involved orbital site was the floor (359 fractures), followed by medial wall (41 fractures) and lateral wall (5 fractures). At presentation, 227 patients (50.7%) had evidence of diplopia. In particular, in most patients, a diplopia in all directions was referred (78 patients). Statistically significant associations were found between diplopia on eye elevation and orbital floor fractures (P diplopia and medial wall fractures (P diplopia on eye elevation and horizontal diplopia at presentation could be useful clinical indicators orbital floor and medial wall fractures, respectively.

  10. Green towers and green walls

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, R. [Sharp and Diamond Landscape Architecture and Planning, Vancouver, BC (Canada)

    2006-07-01

    North American cities face many major environmental and health issues such as urban heat island effect, the intensity of storms, microclimate around buildings, imperviousness of sites, poor air quality and increases in respiratory disease. Several new technologies are starting to address global impacts and community level issues as well as the personal health and comfort of building occupants. These include green towers, living walls, vegetated rooftops and ecological site developments. This paper examined these forms of eco-development and presented their benefits. It discussed green walls in Japan; green towers in Malaysia, Singapore and Great Britain; green facades of climbing plants; active living walls in Canada; and passive living walls in France and Canada. It also discussed thermal walls; thematic walls; vertical gardens and structured wildlife habitat. Last, it presented testing, monitoring, research and conclusions. The Centre for the Advancement of Green Roof Technology is setting up a program to test thermal performance, to assess plant survival and to monitor green walls at the British Columbia Institute of Technology in Vancouver, Canada as much of the research out of Japan is only available in Japanese script. It was concluded that green architecture can provide shade, food, rainwater, shelter for wildlife and mimic natural systems. 15 refs.

  11. Bones of the Earth

    Science.gov (United States)

    Correa, Jose Miguel

    2014-01-01

    The film "Bones of the Earth" (Riglin, Cunninham & Correa, 2014) is an experience in collective inquiry and visual creation based on arts-based research. Starting from the meeting of different subjectivities and through dialogue, planning, shooting and editing, an audiovisual text that reconstructs a reflexive process of collective…

  12. Earth as art 4

    Science.gov (United States)

    ,

    2016-03-29

    Landsat 8 is the latest addition to the long-running series of Earth-observing satellites in the Landsat program that began in 1972. The images featured in this fourth installment of the Earth As Art collection were all acquired by Landsat 8. They show our planet’s diverse landscapes with remarkable clarity.Landsat satellites see the Earth as no human can. Not only do they acquire images from the vantage point of space, but their sensors record infrared as well as visible wavelengths of light. The resulting images often reveal “hidden” details of the Earth’s land surface, making them invaluable for scientific research.As with previous Earth As Art exhibits, these Landsat images were selected solely for their aesthetic appeal. Many of the images have been manipulated to enhance color variations or details. They are not intended for scientific interpretation—only for your viewing pleasure. What do you see in these unique glimpses of the Earth’s continents, islands, and coastlines?

  13. DIORAMA Earth Terrain Model

    Energy Technology Data Exchange (ETDEWEB)

    Werley, Kenneth Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-03-10

    When simulating near-surface nuclear detonations, the terrain of the Earth can have an effect on the observed outputs. The critical parameter is called the “height of burst”. In order to model the effect of terrain on the simulations we have incorporated data from multiple sources to give 9 km resolution data with global coverage.

  14. Magnetic rare earth superlattices

    DEFF Research Database (Denmark)

    Majkrzak, C.F.; Kwo, J.; Hong, M.;

    1991-01-01

    Advances in molecular beam epitaxy deposition techniques have recently made it possible to grow, an atomic plane at a time, single crystalline superlattices composed of alternating layers of a magnetic rare earth, such as Gd, Dy, Ho, or Er, and metallic Y, which has an identical chemical structure...

  15. Google Earth Science

    Science.gov (United States)

    Baird, William H.; Padgett, Clifford W.; Secrest, Jeffery A.

    2015-01-01

    Google Earth has made a wealth of aerial imagery available online at no cost to users. We examine some of the potential uses of that data in illustrating basic physics and astronomy, such as finding the local magnetic declination, using landmarks such as the Washington Monument and Luxor Obelisk as gnomons, and showing how airport runways get…

  16. Understanding Earth's Albedo Effect

    Science.gov (United States)

    Fidler, Chuck

    2012-01-01

    Earth and space science in the middle school classroom are composed of intricately intertwined sets of conceptual systems (AAAS 1993; NRC 1996). Some systems of study, such as the water and rock cycles, are quite explicit and often found as stand-alone middle school science units. Other phenomena are not so apparent, yet they play an extremely…

  17. Olympus and Earth Day

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Let your gaze rest upon the poster for Earth Day on April 22. A small polar bear clings tightly to the stem of an aero-vane. Staring at the vanishing floating ice on the wild sea, his eyes are full of panic and fear.

  18. Google Earth Science

    Science.gov (United States)

    Baird, William H.; Padgett, Clifford W.; Secrest, Jeffery A.

    2015-01-01

    Google Earth has made a wealth of aerial imagery available online at no cost to users. We examine some of the potential uses of that data in illustrating basic physics and astronomy, such as finding the local magnetic declination, using landmarks such as the Washington Monument and Luxor Obelisk as gnomons, and showing how airport runways get…

  19. Rare Earth Market Review

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    @@ Rare earth market continued drop tendency.There was not much transaction of didymium oxide and the alloy. Affected by reduced order of NdFeB magnetic materials and inactive dealings of didymium mischmetal,price of didymium mischmetal had dropped from RMB ¥95,000~98,000/ton to RMBY 93,000~95,000/ton currently.

  20. Cosmic rays on earth

    Energy Technology Data Exchange (ETDEWEB)

    Allkofer, O.C.; Grieder, P.K.F.

    1984-01-01

    A data collection is presented that covers cosmic rays on earth. Included are all relevant data on flux and intensity measurements, energy spectra, and related data of all primary and secondary components of the cosmic radiation at all levels in the atmosphere, at sea level and underground. In those cases where no useful experimental data have been available, theoretical predictions were substituted.

  1. "Galileo Calling Earth..."

    Science.gov (United States)

    National Aeronautics and Space Administration, Washington, DC.

    This guide presents an activity for helping students understand how data from the Galileo spacecraft is sent to scientists on earth. Students are asked to learn about the concepts of bit-rate and resolution and apply them to the interpretation of images from the Galileo Orbiter. (WRM)

  2. Earth flyby anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Nieto, Michael Martin [Los Alamos National Laboratory; Anderson, John D [PROPULSION LAB.

    2009-01-01

    In the planet-centric system, a spacecraft should have the same initial and final energies, even though its energy and angular momentum will change in the barycenter of the solar system. However, without explanation, a number of earth flybys have yielded small energy changes.

  3. Protect the Earth

    Institute of Scientific and Technical Information of China (English)

    张永兴

    2011-01-01

    The earth, a blue globe, is very beautiful. It is the home to all the living things. But the environment around us is becoming worse and worse. People cut down trees to build houses and throw about litter. The air pollution is almost everywhere in the world!

  4. Citizens of Planet Earth

    DEFF Research Database (Denmark)

    Frisk, Kristian

    2015-01-01

    The inability of the nation-state system to handle contemporary environmental issues comprehensively has spurred greater cooperation between religious and secular civil society actors. An empirical analysis of the Alliance of Religions and Conservation (ARC) contributes to knowledge about this pr...... (2010a) have termed Terrapolitan Earth Religion....

  5. Upper bound seismic rotational stability analysis of gravity retaining walls considering embedment depth

    Institute of Scientific and Technical Information of China (English)

    刘杰; 黄达; 杨超; 孙莎

    2015-01-01

    Stability analysis of gravity retaining wall was currently based on the assumption that the wall had no embedment depth. The effect of earth berm was usually neglected. The present work highlighted the importance of embedment depth when assessing the seismic stability of gravity retaining walls with the pattern of pure rotation. In the framework of upper bound theorem of limit analysis, pseudo-static method was applied into two groups of parallel rigid soil slices methods in order to account for the effect of embedment depth on evaluating the critical acceleration of wall-soil system. The present analytical solution is identical to the results obtained from using limit equilibrium method, and the two methods are based on different theory backgrounds. Parameter analysis indicates that the critical acceleration increases slowly when the ratio of the embedment depth to the total height of the wall is from 0 to 0.15 and increases drastically when the ratio exceeds 0.15.

  6. Effects of Antimony and Wall Thickness on Graphite Morphology in Ductile Iron Castings

    Science.gov (United States)

    Glavas, Zoran; Strkalj, Anita; Maldini, Kresimir

    2016-08-01

    Effects of Sb additions on the graphite morphology of ductile iron castings in different wall thicknesses (3, 12, 25, 38, 50, 75, and 100 mm) were analyzed in this paper. In the wall thicknesses of 3, 12, and 25 mm, low contents of rare earth (RE) elements showed a beneficial effect on nodule count and nodularity. Nodularity >80 pct and a high nodule count were achieved without the addition of Sb. In the wall thicknesses of 38, 50, 75, and 100 mm, nodularity >80 pct was not achieved without the use of the chill or proper content of Sb. Excess of RE elements was neutralized with the addition of proper amount of Sb to the wall thickness. Addition of 0.01 wt pct Sb (ratio of RE/Sb = 0.34, ratio of RE/SE = 0.105) was sufficient to achieve nodularity >80 pct in the wall thicknesses of 38, 50, 75, and 100 mm.

  7. Whole-Earth Decompression Dynamics

    CERN Document Server

    Herndon, J M

    2005-01-01

    The principles of Whole-Earth Decompression Dynamics are disclosed leading to a new way to interpret whole-Earth dynamics. Whole-Earth Decompression Dynamics incorporates elements of and unifies the two seemingly divergent dominant theories of continential displacement, plate tectonics theory and Earth expansion theory. Whole-Earth decompression is the consequence of Earth formation from within a Jupiter-like protoplanet with subsequent loss of gases and ices and concomitant rebounding. The initial whole-Earth decompression is expected to result in a global system of major primary decompression cracks appearing in the rigid crust which persist as the basalt feeders for the global, mid-oceanic ridge system. As the Earth subsequently decompresses, the area of the Earth's surface increases by the formation of secondary decompression cracks, often located near the continental margins, presently identified as oceanic trenches. These secondary decompression cracks are subsequently in-filled with basalt, extruded fr...

  8. Use of geosynthetics for performance enhancement of earth structures in cold regions

    Institute of Scientific and Technical Information of China (English)

    Jie Han; Yan Jiang

    2013-01-01

    Earth structures, such as roadways, embankments and slopes, and earth retaining walls, have been commonly used in cold regions for transportation and other applications. In addition to typical design considerations for earth structures at normal temperature, a design must also consider the unique problems associated with low temperature, such as frost heave, lateral expansion, thaw settlement and weakening, and degradation of material properties. Geosynthetics have been used in cold regions to stabilize earth structures during construction and mitigate potential problems during their service at low tem-perature. This paper provides a state of practice review of the use of geosynthetics for performance enhancement of earth structures in cold regions. This paper starts with basic information on available geosynthetic products and their functions, evaluates properties and behavior of geosynthetics and soil-geosynthetic systems at low temperature, and discusses past studies and their key results on the use of geosynthetics to enhance the performance of roadways, embankments, and earth retaining walls in cold regions. This review reveals that geosynthetics at low temperature have higher tensile strength and stiffness, lower creep rate, and lower elongation at failure. The effect of temperature becomes significant when nonwoven geotextiles are subjected to moistening and soil intrusion at subfreezing temperature. Freeze-thaw cycles may degrade hydraulic and mechanical properties of geosynthetic-soil systems. The inclusion of geosynthetics in soil provides drainage and/or barrier to water flow, retains mechanical properties, and reduces frost heave during and after freeze-thaw cycles. Effectiveness of geosynthetics has been confirmed in the field in bridging over voids, stabilizing roadways over temper-ature-susceptible soils during thaw, and proving drainage and barrier to temperature-susceptible soils before freeze. To avoid frost heave and lateral expansion of backfill

  9. The Earth's Biosphere

    Science.gov (United States)

    2002-01-01

    In the last five years, scientists have been able to monitor our changing planet in ways never before possible. The Sea-viewing Wide Field-of-View Sensor (SeaWiFS), aboard the OrbView-2 satellite, has given researchers an unprecedented view of the biological engine that drives life on Earth-the countless forms of plants that cover the land and fill the oceans. 'There is no question the Earth is changing. SeaWiFS has enabled us, for the first time, to monitor the biological consequences of that change-to see how the things we do, as well as natural variability, affect the Earth's ability to support life,' said Gene Carl Feldman, SeaWiFS project manager at NASA's Goddard Space Flight Center, Greenbelt, Md. SeaWiFS data, based on continuous daily global observations, have helped scientists make a more accurate assessment of the oceans' role in the global carbon cycle. The data provide a key parameter in a number of ecological and environmental studies as well as global climate-change modeling. The images of the Earth's changing land, ocean and atmosphere from SeaWiFS have documented many previously unrecognized phenomena. The image above shows the global biosphere from June 2002 measured by SeaWiFS. Data in the oceans is chlorophyll concentration, a measure of the amount of phytoplankton (microscopic plants) living in the ocean. On land SeaWiFS measures Normalized Difference Vegetation Index, an indication of the density of plant growth. For more information and images, read: SeaWiFS Sensor Marks Five Years Documenting Earth'S Dynamic Biosphere Image courtesy SeaWiFS project and copyright Orbimage.

  10. OTVE combustor wall condition monitoring

    Science.gov (United States)

    Szemenyei, Brian; Nelson, Robert S.; Barkhoudarian, S.

    1989-01-01

    Conventional ultrasonics, eddy current, and electromagnetic acoustic transduction (EMAT) technologies were evaluated to determine their capability of measuring wall thickness/wear of individual cooling channels in test specimens simulating conditions in the throat region of an OTVE combustion chamber liner. Quantitative results are presented for the eddy current technology, which was shown to measure up to the optimum 20-mil wall thickness with near single channel resolution. Additional results demonstrate the capability of the conventional ultrasonics and EMAT technologies to detect a thinning or cracked wall. Recommendations for additional eddy current and EMAT development tests are presented.

  11. Economics of abdominal wall reconstruction.

    Science.gov (United States)

    Bower, Curtis; Roth, J Scott

    2013-10-01

    The economic aspects of abdominal wall reconstruction are frequently overlooked, although understandings of the financial implications are essential in providing cost-efficient health care. Ventral hernia repairs are frequently performed surgical procedures with significant economic ramifications for employers, insurers, providers, and patients because of the volume of procedures, complication rates, the significant rate of recurrence, and escalating costs. Because biological mesh materials add significant expense to the costs of treating complex abdominal wall hernias, the role of such costly materials needs to be better defined to ensure the most cost-efficient and effective treatments for ventral abdominal wall hernias.

  12. Earth: A Ringed Planet?

    Science.gov (United States)

    Hancock, L. O.; Povenmire, H.

    2010-12-01

    Among the most beautiful findings of the Space Age have been the discoveries of planetary rings. Not only Saturn but also Jupiter, Uranus and Neptune have rings; Saturn’s ring system has structures newly discovered; even Saturn's moon Rhea itself has a ring. All these are apparently supplied by material from the planetary moons (Rhea's ring by Rhea itself). The question naturally arises, why should the Earth not have a ring, and on the other hand, if it does, why has it not been observed? No rings have yet been observed in the inner solar system, but after all, rings in the inner solar system might simply tend to be fainter and more transient than those of the outer solar system: the inner solar system is more affected by the solar wind, and the Sun’s perturbing gravitational influence is greater. J.A. O’Keefe first suggested (1980) that Earth might have a ring system of its own. An Earth ring could account for some climate events. O’Keefe remarked that formation or thickening of a ring system in Earth’s equatorial plane could drive glaciation by deepening the chill of the winter hemisphere. (It is very well established that volcanic dust is an effective agent for the extinction of sunlight; this factor can be overwhelmingly apparent in eclipse observations.) O’Keefe died in 2000 and the speculation was not pursued, but the idea of an Earth ring has a prima facie reasonableness that calls for its renewed consideration. The program of this note is to hypothesize that, as O’Keefe proposed: (a) an Earth ring system exists; (b) it affects Earth's weather and climate; (c) the tektite strewn fields comprise filaments of the ring fallen to Earth's surface on various occasions of disturbance by comets or asteroids. On this basis, and drawing on the world's weather records, together with the Twentieth Century Reanalysis by NCEP/CIRES covering the period 1870-2010 and the geology of the tektite strewn fields, we herein propose the hypothesized Earth ring

  13. Space vehicle with artificial gravity and earth-like environment

    Science.gov (United States)

    Gray, V. H. (Inventor)

    1973-01-01

    A space vehicle adapted to provide an artificial gravity and earthlike atmospheric environment for occupants is disclosed. The vehicle comprises a cylindrically shaped, hollow pressure-tight body, one end of which is tapered from the largest diameter of the body, the other end is flat and transparent to sunlight. The vehicle is provided with thrust means which rotates the body about its longitudinal axis, generating an artificial gravity effect upon the interior walls of the body due to centrifugal forces. The walls of the tapered end of the body are maintained at a temperature below the dew point of water vapor in the body and lower than the temperature near the transparent end of the body. The controlled environment and sunlight permits an earth like environment to be maintained wherein the CO2/O2 is balanced, and food for the travelers is supplied through a natural system of plant life grown on spacecraft walls where soil is located.

  14. Rotation and magnetism of Earth`s inner core

    Energy Technology Data Exchange (ETDEWEB)

    Glatzmaier, G.A. [Los Alamos National Lab., NM (United States); Roberts, P.H. [Univ. of California, Los Angeles, CA (United States)

    1996-12-13

    Three-dimensional numerical simulations of the geodynamo suggest that a super-rotation of Earth`s solid inner core relative to the mantle is maintained by magnetic coupling between the inner core and an eastward thermal wind in the fluid outer core. This mechanism, which is analogous to a synchronous motor, also plays a fundamental role in the generation of Earth`s magnetic field. 18 refs., 6 figs.

  15. Intrinsic Evaporative Cooling by Hygroscopic Earth Materials

    Directory of Open Access Journals (Sweden)

    Alexandra R. Rempel

    2016-08-01

    Full Text Available The phase change of water from liquid to vapor is one of the most energy-intensive physical processes in nature, giving it immense potential for cooling. Diverse evaporative cooling strategies have resulted worldwide, including roof ponds and sprinklers, courtyard fountains, wind catchers with qanats, irrigated green roofs, and fan-assisted evaporative coolers. These methods all require water in bulk liquid form. The evaporation of moisture that has been sorbed from the atmosphere by hygroscopic materials is equally energy-intensive, however, yet has not been examined for its cooling potential. In arid and semi-arid climates, hygroscopic earth buildings occur widely and are known to maintain comfortable indoor temperatures, but evaporation of moisture from their walls and roofs has been regarded as unimportant since water scarcity limits irrigation and rainfall; instead, their cool interiors are attributed to well-established mass effects in delaying the transmission of sensible gains. Here, we investigate the cooling accomplished by daily cycles of moisture sorption and evaporation which, requiring only ambient humidity, we designate as “intrinsic” evaporative cooling. Connecting recent soil science to heat and moisture transport studies in building materials, we use soils, adobe, cob, unfired earth bricks, rammed earth, and limestone to reveal the effects of numerous parameters (temperature and relative humidity, material orientation, thickness, moisture retention properties, vapor diffusion resistance, and liquid transport properties on the magnitude of intrinsic evaporative cooling and the stabilization of indoor relative humidity. We further synthesize these effects into concrete design guidance. Together, these results show that earth buildings in diverse climates have significant potential to cool themselves evaporatively through sorption of moisture from humid night air and evaporation during the following day’s heat. This finding

  16. Juyongguan on the Great Wall

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Juyongguan Pass on the Great Wall,one ofthe most important strategic passes of the oldcapital Beijing,is now repaired and a goodplace for tourists to see ancient Chinesemilitary and cultural facilities,as well asbeautiful local scenery.

  17. Statistical characteristics of simulated walls

    CERN Document Server

    Demianski, M; Müller, V; Turchaninov, V I

    2000-01-01

    The large scale matter distribution in three different simulations of CDM models is investigated and compared with corresponding results of the Zel'dovich theory of nonlinear gravitational instability. We show that the basic characteristics of wall-like structure elements are well described by this theory, and that they can be expressed by the cosmological parameters and a few spectral moments of the perturbation spectrum. Therefore the characteristics of such elements provide reasonable estimates of these parameters. We show that the compressed matter is relaxed and gravitationally confined, what manifests itself in the existence of walls as (quasi)stationary structure elements with life time restricted by their disruption into high density clouds. The matter distribution is investigated both in the real and redshift spaces. In both cases almost the same particles form the walls, and we estimate differences in corresponding wall characteristics. The same methods are applied to several mock catalogues of 'gal...

  18. Earth Science Multimedia Theater

    Science.gov (United States)

    Hasler, A. F.

    1998-01-01

    The presentation will begin with the latest 1998 NASA Earth Science Vision for the next 25 years. A compilation of the 10 days of animations of Hurricane Georges which were supplied daily on NASA to Network television will be shown. NASA's visualizations of Hurricane Bonnie which appeared in the Sept 7 1998 issue of TIME magazine. Highlights will be shown from the NASA hurricane visualization resource video tape that has been used repeatedly this season on network TV. Results will be presented from a new paper on automatic wind measurements in Hurricane Luis from 1 -min GOES images that will appear in the October BAMS. The visualizations are produced by the Goddard Visualization & Analysis Laboratory, and Scientific Visualization Studio, as well as other Goddard and NASA groups using NASA, NOAA, ESA, and NASDA Earth science datasets. Visualizations will be shown from the "Digital-HyperRes-Panorama" Earth Science ETheater'98 recently presented in Tokyo, Paris and Phoenix. The presentation in Paris used a SGI/CRAY Onyx Infinite Reality Super Graphics Workstation at 2560 X 1024 resolution with dual synchronized video Epson 71 00 projectors on a 20ft wide screen. Earth Science Electronic Theater '999 is being prepared for a December 1 st showing at NASA HQ in Washington and January presentation at the AMS meetings in Dallas. The 1999 version of the Etheater will be triple wide with at resolution of 3840 X 1024 on a 60 ft wide screen. Visualizations will also be featured from the new Earth Today Exhibit which was opened by Vice President Gore on July 2, 1998 at the Smithsonian Air & Space Museum in Washington, as well as those presented for possible use at the American Museum of Natural History (NYC), Disney EPCOT, and other venues. New methods are demonstrated for visualizing, interpreting, comparing, organizing and analyzing immense Hyperimage remote sensing datasets and three dimensional numerical model results. We call the data from many new Earth sensing satellites

  19. Visualizing Earth Materials

    Science.gov (United States)

    Cashman, K. V.; Rust, A.; Stibbon, E.; Harris, R.

    2016-12-01

    Earth materials are fundamental to art. They are pigments, they are clay, they provide form and color. Earth scientists, however, rarely attempt to make the physical properties of Earth materials visible through art, and similarly many artists use Earth materials without fully understanding their physical and chemical properties. Here we explore the intersection between art and science through study of the physical properties of Earth materials as characterized in the laboratory, and as transferred to paper using different techniques and suspending media. One focus of this collaboration is volcanic ash. Ash is interesting scientifically because its form provides information on the fundamental processes that drive volcanic eruptions, and determines its transport properties, and thus its potential to affect populations far downwind of the volcano. Ash properties also affect its behavior as an art material. From an aesthetic point of view, ash lends a granular surface to the image; it is also uncontrollable, and thus requires engagement between artist and medium. More fundamentally, using ash in art creates an exchange between the medium and the subject matter, and imparts something of the physical, visceral experience of volcanic landscapes to the viewer. Another component of this work uses powdered rock as a printing medium for geologic maps. Because different types of rock create powders with different properties (grain size distributions and shapes), the geology is communicated not only as color, but also by the physical characteristics of the material as it interacts with the paper. More importantly, the use of actual rocks samples as printing material for geologic maps not only makes a direct connection between the map and the material it represents, but also provides an emotional connection between the map, the viewer and the landscape, its colors, textures and geological juxtapositions. Both case studies provide examples not only of ways in which artists can

  20. Towards earth AntineutRino TomograpHy (EARTH)

    NARCIS (Netherlands)

    De Meijer, R. J.; Smit, F. D.; Brooks, F. D.; Fearick, R. W.; Wortche, H. J.; Mantovani, F.

    2006-01-01

    The programme Earth AntineutRino TomograpHy (EARTH) proposes to build ten underground facilities each hosting a telescope. Each telescope consists of many detector modules, to map the radiogenic heat sources deep in the interior of the Earth by utilising direction sensitive geoneutrino detection.

  1. Nano magnetic vortex wall guide

    Directory of Open Access Journals (Sweden)

    H. Y. Yuan

    2015-11-01

    Full Text Available A concept of nano magnetic vortex wall guide is introduced. Two architectures are proposed. The first one is properly designed superlattices while the other one is bilayer nanostrips. The concept is verified by micromagnetic simulations. Both guides can prevent the vortex core in a magnetic vortex wall from colliding with sample surface so that the information stored in the vortex core can be preserved during its transportation from one location to another one through the guides.

  2. Actinomycosis - Left Post Chest Wall

    Directory of Open Access Journals (Sweden)

    Kafil Akhtar, M. Naim, S. Shamshad Ahmad, Nazoora Khan, Uroos Abedi, A.H. Khan*

    2008-01-01

    Full Text Available A forty year old female of weak body built presented with recurring small hard lumps in let posteriorchest wall for 3 years and discharging ulcers for 3 months duration. Clinically, the provisional diagnosiswas malignancy with secondary infection. FNAC showed features suggestive of dysplasia buthistopathology confirmed the diagnosis as actinomycosis. The present case is reported due to rare incidenceof actinomycosis at post chest wall with muscle involvement.

  3. CHEST WALL HAMARTOMA : Case Report

    OpenAIRE

    Gülden DİNİZ; Ortaç, Ragıp; Aktaş, Safiye; TEMİR, Günyüz; HOŞGÖR, Münevver; Karaca, İrfan

    2005-01-01

    A case of four-month – old girl diagnosed as chest wall hamartoma is presented. This entity is an extremely rare but characteristic lesion of the ribs usually presenting in the neonate or infant with a mass or respiratory symptoms. Complete sponraneous regression of the lesion has been reported. Recently conservative management of asymptomatic childiren was recommended. Although rare, this condition ought to be kept in mind while dealing with infantile chest wall masses to avoid an errone...

  4. CHEST WALL HAMARTOMA : Case Report

    OpenAIRE

    Gülden DİNİZ; Ortaç, Ragıp; Aktaş, Safiye; HOŞGÖR, Günyüz TEMİR2Münevver; Karaca, İrfan

    2005-01-01

    A case of four-month – old girl diagnosed as chest wall hamartoma is presented. This entity is an extremely rare but characteristic lesion of the ribs usually presenting in the neonate or infant with a mass or respiratory symptoms. Complete sponraneous regression of the lesion has been reported. Recently conservative management of asymptomatic childiren was recommended. Although rare, this condition ought to be kept in mind while dealing with infantile chest wall masses to avoid...

  5. Permeable conformal walls and holography

    Science.gov (United States)

    Bachas, Constantin; de Boer, Jan; Dijkgraaf, Robbert; Ooguri, Hirosi

    2002-06-01

    We study conformal field theories in two dimensions separated by domain walls, which preserve at least one Virasoro algebra. We develop tools to study such domain walls, extending and clarifying the concept of `folding' discussed in the condensed-matter literature. We analyze the conditions for unbroken supersymmetry, and discuss the holographic duals in AdS3 when they exist. One of the interesting observables is the Casimir energy between a wall and an anti-wall. When these separate free scalar field theories with different target-space radii, the Casimir energy is given by the dilogarithm function of the reflection probability. The walls with holographic duals in AdS3 separate two sigma models, whose target spaces are moduli spaces of Yang-Mills instantons on T4 or K3. In the supergravity limit, the Casimir energy is computable as classical energy of a brane that connects the walls through AdS3. We compare this result with expectations from the sigma-model point of view.

  6. Permeable conformal walls and holography

    CERN Document Server

    Bachas, C P; Dijkgraaf, R; Ooguri, H

    2002-01-01

    We study conformal field theories in two dimensions separated by domain walls, which preserve at least one Virasoro algebra. We develop tools to study such domain walls, extending and clarifying the concept of `folding' discussed in the condensed-matter literature. We analyze the conditions for unbroken supersymmetry, and discuss the holographic duals in AdS3 when they exist. One of the interesting observables is the Casimir energy between a wall and an anti-wall. When these separate free scalar field theories with different target-space radii, the Casimir energy is given by the dilogarithm function of the reflection probability. The walls with holographic duals in AdS3 separate two sigma models, whose target spaces are moduli spaces of Yang-Mills instantons on T4 or K3. In the supergravity limit, the Casimir energy is computable as classical energy of a brane that connects the walls through AdS3. We compare this result with expectations from the sigma-model point of view.

  7. Wall force produced during disruptions

    Science.gov (United States)

    Strauss, H.; Paccagnella, R.; Breslau, J.

    2009-11-01

    The study of disruptions is of great importance for ITER. Previous work on disruptions [1] is extended to compute toroidally asymmetric wall force in ITER, using the M3D code. The disruptions are produced by n = 1 resistive wall modes or external kink modes. A thin wall resistive boundary model is used to calculate the wall forces. The symmetric wall force, produced by a VDE, and the asymmetric wall force, produced by n = 1 modes, are comparable in magnitude. It is found that the asymmetric and axisymmetric forces scale with the growth rate of the instability multiplied by the square of the current divided by magnetic field. A similar scaling was reported for VDEs in JET [2]. Numerically, the study of disruptions is very challenging. In the M3D extended MHD code, dealiasing was applied in the toroidal direction. Advection terms were treated with a numerical upwind method. These techniques provided sufficient numerical stability to simulate entire disruption events. [4pt] [1] R. Paccagnella, H. R. Strauss, and J. Breslau, Nucl. Fusion (2009) 49 035003. [2] V. Riccardo, T. C. Hender, P. J. Lomas, et al., Plasma Phys. Control. Fusion (2004)

  8. China Rare Earth Market Review

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ February, 2010 Rare earth separation plants and downstream producers like NdFeB magnetic materials and phosphor materials successively ceased production due to Spring Festival, Chinese New Year. Transactions in rare earth market were few affected by public holidays.

  9. Mirador - Earth Surface and Interior

    Data.gov (United States)

    National Aeronautics and Space Administration — Earth Science data access made simple. The goal of the Earth Surface and Interior focus area is to assess, mitigate and forecast the natural hazards that affect...

  10. China Rare Earth Market Review

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ Active demands from downstream industry drove the price rise of rare earth products in Chinese domestic marketrecently, particularly didymium and dysprosium products. Prices of other rare earth products remained stable.

  11. China rare earth market review

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Rare earth market fluctuated slightly recently and the transactions remained sluggish. Environment control was strengthened in southern China and many rare earth plants had gone out of production. Some traders were considering selling commodities at low p

  12. NASA Benefits Earth

    Science.gov (United States)

    Robinson, Julie A.

    2009-01-01

    This slide presentation reviews several ways in which NASA research has benefited Earth and made life on Earth better. These innovations include: solar panels, recycled pavement, thermometer pill, invisible braces for straightening teeth, LASIK, aerodynamic helmets and tires for bicycles, cataract detection, technology that was used to remove Anthrax spores from mail handling facilities, study of atomic oxygen erosion of materials has informed the restoration of artwork, macroencapsulation (a potential mechanism to deliver anti cancer drugs to specific sites), and research on a salmonella vaccine. With research on the International Space Station just beginning, there will be opportunities for entrepreneurs and other government agencies to access space for their research and development. As well as NASA continuing its own research on human health and technology development.

  13. Life Before Earth

    CERN Document Server

    Sharov, Alexei A

    2013-01-01

    An extrapolation of the genetic complexity of organisms to earlier times suggests that life began before the Earth was formed. Life may have started from systems with single heritable elements that are functionally equivalent to a nucleotide. The genetic complexity, roughly measured by the number of non-redundant functional nucleotides, is expected to have grown exponentially due to several positive feedback factors: gene cooperation, duplication of genes with their subsequent specialization, and emergence of novel functional niches associated with existing genes. Linear regression of genetic complexity on a log scale extrapolated back to just one base pair suggests the time of the origin of life 9.7 billion years ago. This cosmic time scale for the evolution of life has important consequences: life took ca. 5 billion years to reach the complexity of bacteria; the environments in which life originated and evolved to the prokaryote stage may have been quite different from those envisaged on Earth; there was no...

  14. Heat-pipe Earth.

    Science.gov (United States)

    Moore, William B; Webb, A Alexander G

    2013-09-26

    The heat transport and lithospheric dynamics of early Earth are currently explained by plate tectonic and vertical tectonic models, but these do not offer a global synthesis consistent with the geologic record. Here we use numerical simulations and comparison with the geologic record to explore a heat-pipe model in which volcanism dominates surface heat transport. These simulations indicate that a cold and thick lithosphere developed as a result of frequent volcanic eruptions that advected surface materials downwards. Declining heat sources over time led to an abrupt transition to plate tectonics. Consistent with model predictions, the geologic record shows rapid volcanic resurfacing, contractional deformation, a low geothermal gradient across the bulk of the lithosphere and a rapid decrease in heat-pipe volcanism after initiation of plate tectonics. The heat-pipe Earth model therefore offers a coherent geodynamic framework in which to explore the evolution of our planet before the onset of plate tectonics.

  15. Testing MOND on Earth

    CERN Document Server

    Ignatiev, A Yu

    2014-01-01

    MOND is one of the most popular alternatives to Dark Matter (DM). While efforts to directly detect DM in laboratories have been steadily pursued over the years, the proposed Earth-based tests of MOND are still in their infancy. Some proposals recently appeared in the literature are briefly reviewed, and it is argued that collaborative efforts of theorists and experimenters are needed to move forward in this exciting new area. Possible future directions are outlined.

  16. Superhydrophobic diatomaceous earth

    Science.gov (United States)

    Simpson, John T [Clinton, TN; D& #x27; Urso, Brian R [Clinton, TN

    2012-07-10

    A superhydrophobic powder is prepared by coating diatomaceous earth (DE) with a hydrophobic coating on the particle surface such that the coating conforms to the topography of the DE particles. The hydrophobic coating can be a self assembly monolayer of a perfluorinated silane coupling agent. The DE is preferably natural-grade DE where organic impurities have been removed. The superhydrophobic powder can be applied as a suspension in a binder solution to a substrate to produce a superhydrophobic surface on the substrate.

  17. Why Earth aurorae shine?

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ By using the data obtained from three satellites of the Cluster mission launched by the European Space Agency (ESA), CAO Jinbin from the CAS Center for Space Science and Applied Research (CSSAR) and his US and European co-workers have clarified why Earth's aurorae shine.Their work entitled Joint Observations by Cluster Satellites of Bursty Bulk Flows in the Magnetotail was published in a recent issue of Journal of Geophysical Research.

  18. Life Before Earth

    OpenAIRE

    Sharov, Alexei A; Gordon, Richard

    2013-01-01

    An extrapolation of the genetic complexity of organisms to earlier times suggests that life began before the Earth was formed. Life may have started from systems with single heritable elements that are functionally equivalent to a nucleotide. The genetic complexity, roughly measured by the number of non-redundant functional nucleotides, is expected to have grown exponentially due to several positive feedback factors: gene cooperation, duplication of genes with their subsequent specialization,...

  19. Mission to Planet Earth

    Science.gov (United States)

    Tilford, Shelby G.; Wilson, Gregory S.; Backlund, Peter W.

    1991-01-01

    The NASA program described is an international study to predict changes in the earth's environment by means of multidisciplinary remote sensing from satellites. An international consortium dedicates satellites with advanced sensors to data collection, and a data processing system is described to collect and analyze a large amount of terrestrial data. The program requires international multidisciplinary involvement to collect and interpret the data and thereby manage and preserve the global environment.

  20. Earth Abides Arsenic Biotransformations

    OpenAIRE

    Zhu, Yong-Guan; Yoshinaga, Masafumi; Zhao, Fang-Jie; Rosen, Barry P.

    2014-01-01

    Arsenic is the most prevalent environmental toxic element and causes health problems throughout the world. The toxicity, mobility, and fate of arsenic in the environment are largely determined by its speciation, and arsenic speciation changes are driven, at least to some extent, by biological processes. In this article, biotransformation of arsenic is reviewed from the perspective of the formation of Earth and the evolution of life, and the connection between arsenic geochemistry and biology ...

  1. Earth before life

    OpenAIRE

    Marzban, Caren; Viswanathan, Raju; Yurtsever, Ulvi

    2014-01-01

    Background A recent study argued, based on data on functional genome size of major phyla, that there is evidence life may have originated significantly prior to the formation of the Earth. Results Here a more refined regression analysis is performed in which 1) measurement error is systematically taken into account, and 2) interval estimates (e.g., confidence or prediction intervals) are produced. It is shown that such models for which the interval estimate for the time origin of the genome i...

  2. Hunan Rare Earth Group Approved

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    <正>Following Guangdong,Guangxi,Fujian and Jiangxi,Hunan announced that it would consolidate its rare earth resources-the consolidation plan of Hunan Rare Earth Group has been approved. Consolidation of the rare earth industry of south China is in full swing.According to "Several Opinions of the State Council on Promoting the Sustainable and Healthy Development of Rare Earth Industry"(hereinafter referred to as "Several Opinions")released in 2011,

  3. China Rare Earth Market Review

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    September 20-30, 2011 Rare earth market remained steady recently. Quoted prices of didymium products by separation and smelting plants kept stable. Some rare earth industrial zones in Baotou, Sichuan and Ganzhou had suspended production with the intensified environmental protection control and consolidation of rare earth industry. Persons in the industry hold a positive attitude toward the rare earth market after the National Day' s holiday in China. The market will develop healthily and orderly in the future.

  4. Characterising Super-Earths

    Directory of Open Access Journals (Sweden)

    Valencia D.

    2011-02-01

    Full Text Available The era of Super-Earths has formally begun with the detection of transiting low-mass exoplanets CoRoT-7b and GJ 1214b. In the path of characterising super-Earths, the first step is to infer their composition. While the discovery data for CoRoT-7b, in combination with the high atmospheric mass loss rate inferred from the high insolation, suggested that it was a rocky planet, the new proposed mass values have widened the possibilities. The combined mass range 1−10 M⊕ allows for a volatile-rich (and requires it if the mass is less than 4 M⊕ , an Earth-like or a super-Mercury-like composition. In contrast, the radius of GJ 1214b is too large to admit a solid composition, thus it necessarily to have a substantial gas layer. Some evidence suggests that within this gas layer H/He is a small but non-negligible component. These two planets are the first of many transiting low-mass exoplanets expected to be detected and they exemplify the limitations faced when inferring composition, which come from the degenerate character of the problem and the large error bars in the data.

  5. EARTH ROADS ARE EASY

    Directory of Open Access Journals (Sweden)

    David O. Whitten

    2000-01-01

    Full Text Available The earliest European immigrants in America traveled on waterways and on pathways worn into the earth by animals and Native Americans. Once their communities began to thrive, settlers widened paths and cleared new roads and streets then began experimenting with inexpensive surfacing to reduce dust in dry weather and mud in wet. “Earth Roads Are Easy” investigates materials and techniques used to maintain primitive thoroughfares with a minimum of effort and expense. The options range from the mundane—clay, sand, gravel, calcium chloride, oil, and tar—to the extraordinary—water glass, adobe clay, beet juice, and carpeting.There is no more dfficult problem confronting highway engineers than that of properly constructing and maintaining an earth road. The work may be less spectacular than the construction and maintenance of hard-surfaced roads, but there is greater latitude in location, methods of construction and choice of materials, consequently there is more scope for the exercise of sound judgment on the part of the engineer.1

  6. The Active Solid Earth

    Science.gov (United States)

    Ebinger, Cynthia

    2016-04-01

    Dynamic processes in Earth's crust, mantle and core shape Earth's surface and magnetic field over time scales of seconds to millennia, and even longer time scales as recorded in the ca. 4 Ga rock record. Our focus is the earthquake-volcano deformation cycles that occur over human time scales, and their comparison with time-averaged deformation studies, with emphasis on mantle plume provinces where magma and volatile release and vertical tectonics are readily detectable. Active deformation processes at continental and oceanic rift and back arc zones provide critical constraints on mantle dynamics, the role of fluids (volatiles, magma, water), and plate rheology. For example, recent studies of the East African rift zone, which formed above one of Earth's largest mantle upwellings reveal that magma production and volatile release rates are comparable to those of magmatic arcs, the archetypal zones of continental crustal creation. Finite-length faults achieve some plate deformation, but magma intrusion in the form of dikes accommodates extension in continental, back-arc, and oceanic rifts, and intrusion as sills causes permanent uplift that modulates the local time-space scales of earthquakes and volcanoes. Volatile release from magma intrusion may reduce fault friction and permeability, facilitating aseismic slip and creating magma pathways. We explore the implications of active deformation studies to models of the time-averaged structure of plume and extensional provinces in continental and oceanic plate settings.

  7. Earth System Monitoring, Introduction

    Science.gov (United States)

    Orcutt, John

    This section provides sensing and data collection methodologies, as well as an understanding of Earth's climate parameters and natural and man-made phenomena, to support a scientific assessment of the Earth system as a whole, and its response to natural and human-induced changes. The coverage ranges from climate change factors and extreme weather and fires to oil spill tracking and volcanic eruptions. This serves as a basis to enable improved prediction and response to climate change, weather, and natural hazards as well as dissemination of the data and conclusions. The data collection systems include satellite remote sensing, aerial surveys, and land- and ocean-based monitoring stations. Our objective in this treatise is to provide a significant portion of the scientific and engineering basis of Earth system monitoring and to provide this in 17 detailed articles or chapters written at a level for use by university students through practicing professionals. The reader is also directed to the closely related sections on Ecological Systems, Introduction and also Climate Change Modeling Methodology, Introduction as well as Climate Change Remediation, Introduction to. For ease of use by students, each article begins with a glossary of terms, while at an average length of 25 print pages each, sufficient detail is presented for use by professionals in government, universities, and industries. The chapters are individually summarized below.

  8. Afganistan and rare earths

    Directory of Open Access Journals (Sweden)

    Emilian M. Dobrescu

    2013-05-01

    Full Text Available On our planet, over a quarter of new technologies for the economic production of industrial goods, are using rare earths, which are also called critical minerals and industries that rely on these precious items being worth of an estimated nearly five trillion dollars, or 5 percent of world gross domestic product. In the near future, competition will increase for the control of rare earth minerals embedded in high-tech products. Rare minerals are in the twenty-first century what oil accounted for in the twentieth century and coal in the nineteenth century: the engine of a new industrial revolution. Future energy will be produced increasingly by more sophisticated technological equipment based not just on steel and concrete, but incorporating significant quantities of metals and rare earths. Widespread application of these technologies will result in an exponential increase in demand for such minerals, and what is worrying is that minerals of this type are almost nowhere to be found in Europe and in other industrialized countries in the world, such as U.S. and Japan, but only in some Asian countries, like China and Afghanistan.

  9. Sun, Earth and Sky

    CERN Document Server

    Lang, Kenneth R

    2006-01-01

    This Second Edition of Sun, Earth and Sky updates the popular text by providing comprehensive accounts of the most recent discoveries made by five modern solar spacecraft during the past decade. Their instruments have used sound waves to peer deep into the Sun’s inner regions and measure the temperature of its central nuclear reactor, and extended our gaze far from the visible Sun to record energetic outbursts that threaten Earth. Breakthrough observations with the underground Sudbury Neutrino Observatory are also included, which explain the new physics of ghostly neutrinos and solve the problematic mismatch between the predicted and observed amounts of solar neutrinos. This new edition of Sun, Earth and Sky also describes our recent understanding of how the Sun’s outer atmosphere is heated to a million degrees, and just where the Sun’s continuous winds come from. As humans we are more intimately linked with our life-sustaining Sun than with any other astronomical object, and the new edition therefore p...

  10. Mineral remains of early life on Earth? On Mars?

    Science.gov (United States)

    Iberall, Robbins E.; Iberall, A.S.

    1991-01-01

    The oldest sedimentary rocks on Earth, the 3.8-Ga Isua Iron-Formation in southwestern Greenland, are metamorphosed past the point where organic-walled fossils would remain. Acid residues and thin sections of these rocks reveal ferric microstructures that have filamentous, hollow rod, and spherical shapes not characteristic of crystalline minerals. Instead, they resemble ferric-coated remains of bacteria. Because there are no earlier sedimentary rocks to study on Earth, it may be necessary to expand the search elsewhere in the solar system for clues to any biotic precursors or other types of early life. A study of morphologies of iron oxide minerals collected in the southern highlands during a Mars sample return mission may therefore help to fill in important gaps in the history of Earth's earliest biosphere. -from Authors

  11. China Rare Earth Market Review

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ Supply of rare earth concentrate remained tight recently. Rare earth market exhibited rising tendency holistically Affected by tight supply of rare earth concentrate, many plants were operated under the capacity. Supply of didymium oxide got tighter and the price was on rising.

  12. Strategy for earth explorers in global earth sciences

    Science.gov (United States)

    1988-01-01

    The goal of the current NASA Earth System Science initiative is to obtain a comprehensive scientific understanding of the Earth as an integrated, dynamic system. The centerpiece of the Earth System Science initiative will be a set of instruments carried on polar orbiting platforms under the Earth Observing System program. An Earth Explorer program can open new vistas in the earth sciences, encourage innovation, and solve critical scientific problems. Specific missions must be rigorously shaped by the demands and opportunities of high quality science and must complement the Earth Observing System and the Mission to Planet Earth. The committee believes that the proposed Earth Explorer program provides a substantial opportunity for progress in the earth sciences, both through independent missions and through missions designed to complement the large scale platforms and international research programs that represent important national commitments. The strategy presented is intended to help ensure the success of the Earth Explorer program as a vital stimulant to the study of the planet.

  13. The Layer Cake Walls of Valles Marineris

    Science.gov (United States)

    2007-01-01

    This image of the northern wall of Coprates Chasma, in Valles Marineris, was taken by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) at 1227 UTC (8:27 a.m. EDT) on June 16, 2007, near 13.99 degrees south latitude, 303.09 degrees east longitude. CRISM's image was taken in 544 colors covering 0.36-3.92 micrometers, and shows features as small as 20 meters (66 feet) across. The region covered is just over 10 kilometers (6.2 miles) wide at its narrowest point. Valles Marineris is a large canyon system straddling Mars' equator, with a total size approximating the Mediterranean Sea emptied of water. It is subdivided into several interconnected 'chasmata' each hundreds of kilometers wide and, in some cases, thousands of kilometers long. The walls of several of the chasmata, including Coprates Chasma, expose a section of Mars' upper crust about 5 kilometers (3 miles) in depth. Exposures like these show the layers of rock that record the formation of Mars' crust over geologic time, much as the walls of the Grand Canyon on Earth show part of our planet's history. The upper panel of this montage shows the location of the CRISM image on a mosaic from the Mars Odyssey spacecraft's Thermal Emission Imaging System (THEMIS), taken in longer infrared wavelengths than measured by CRISM. The CRISM image samples the base of Coprates Chasma's wall, including a conspicuous horizontal band that continues along the wall for tens of kilometers to the east and west, and a topographic shelf just above that. The middle two panels show the CRISM image in visible and infrared light. In the middle left panel, the red, green, and blue image planes show brightness at 0.59, 0.53, and 0.48 microns, similar to what the human eye would see. Color variations are subdued by the presence of dust on all exposed surfaces. In the middle right panel, the red, green, and blue image planes show brightness at 2.53, 1.51, and 1.08 microns. These three infrared wavelengths are the 'usual' set

  14. Effects of the flexibility of the arterial wall on the wall shear stresses and wall tension in Abdominal Aortic Aneurysms.

    Science.gov (United States)

    Salsac, Anne-Virginie; Fernandez, Miguel; Chomaz, Jean-Marc

    2005-11-01

    As an abdominal aortic aneurysm develops, large changes occur in the composition and structure of the arterial wall, which result in its stiffening. So far, most studies, whether experimental or numerical, have been conducted assuming the walls to be rigid. A numerical simulation of the fluid structure interactions is performed in different models of aneurysms in order to analyze the effects that the wall compliance might have on the flow topology. Both symmetric and non-symmetric models of aneurysms are considered, all idealistic in shape. The wall mechanical properties are varied in order to simulate the progressive stiffening of the walls. The spatial and temporal distributions of wall tension are calculated for the different values of the wall elasticity and compared to the results for the rigid walls. In the case of rigid walls, the calculation of the wall shear stresses and pressure compare very well with experimental results.

  15. Parametric study of cantilever walls subjected to seismic loading

    Science.gov (United States)

    Comina, Cesare; Corigliano, Mirko; Foti, Sebastiano; Lai, Carlo G.; Lancellotta, Renato; Leuzzi, Francesco; Nicosia, Giovanni Li Destri; Paolucci, Roberto; Pettiti, Alberto; Psarropoulos, Prodromos N.; Zanoli, Omar

    2008-07-01

    The design of flexible earth retaining structures under seismic loading is a challenging geotechnical problem, the dynamic soil-structure interaction being of paramount importance for this kind of structures. Pseudo-static approaches are often adopted but do not allow a realistic assessment of the performance of the structure subjected to the seismic motions. The present paper illustrates a numerical parametric study aimed at estimating the influence of the dynamic soil-structure interaction in the design. A series of flexible earth retaining walls have been preliminary designed according to the requirements of Eurocode 7 and Eurocode 8—Part 5; their dynamic behaviour has been then evaluated by means of dynamic numerical simulations in terms of bending moments, accelerations and stress state. The results obtained from dynamic analyses have then been compared with those determined using the pseudo-static approach.

  16. The thick left ventricular wall of the giraffe heart normalises wall tension, but limits stroke volume and cardiac output

    DEFF Research Database (Denmark)

    Smerup, Morten Holdgaard; Damkjær, Mads; Brøndum, Emil

    2016-01-01

    cavity and a relatively thick ventricular wall, allowing for generation of high arterial pressures at normal left ventricular wall tension. In nine anaesthetized giraffes (495±38 kg), we determined in vivo ventricular dimensions using echocardiography along with intraventricular and aortic pressures......Giraffes--the tallest extant animals on Earth--are renowned for their high central arterial blood pressure, which is necessary to secure brain perfusion. Arterial pressure may exceed 300 mmHg and has historically been attributed to an exceptionally large heart. Recently, this has been refuted...... by several studies demonstrating that the mass of giraffe heart is similar to that of other mammals when expressed relative to body mass. It thus remains unexplained how the normal-sized giraffe heart generates such massive arterial pressures. We hypothesized that giraffe hearts have a small intraventricular...

  17. Isolation of the Cell Wall.

    Science.gov (United States)

    Canut, Hervé; Albenne, Cécile; Jamet, Elisabeth

    2017-01-01

    This chapter describes a method allowing the purification of the cell wall for studying both polysaccharides and proteins. The plant primary cell wall is mainly composed of polysaccharides (90-95 % in mass) and of proteins (5-10 %). At the end of growth, specialized cells may synthesize a lignified secondary wall composed of polysaccharides (about 65 %) and lignin (about 35 %). Due to its composition, the cell wall is the cellular compartment having the highest density and this property is used for its purification. It plays critical roles during plant development and in response to environmental constraints. It is largely used in the food and textile industries as well as for the production of bioenergy. All these characteristics and uses explain why its study as a true cell compartment is of high interest. The proposed method of purification can be used for large amount of material but can also be downscaled to 500 mg of fresh material. Tools for checking the quality of the cell wall preparation, such as protein analysis and microscopy observation, are also provided.

  18. Identifying early Earth microfossils in unsilicified sediments

    Science.gov (United States)

    Javaux, Emmanuelle J.; Asael, Dan; Bekker, Andrey; Debaille, Vinciane; Derenne, Sylvie; Hofmann, Axel; Mattielli, Nadine; Poulton, Simon

    2013-04-01

    The search for life on the early Earth or beyond Earth requires the definition of biosignatures, or "indices of life". These traditionally include fossil molecules, isotopic fractionations, biosedimentary structures and morphological fossils interpreted as remnants of life preserved in rocks. This research focuses on traces of life preserved in unsilicified siliciclastic sediments. Indeed, these deposits preserve well sedimentary structures indicative of past aqueous environments and organic matter, including the original organic walls of microscopic organisms. They also do not form in hydrothermal conditions which may be source of abiotic organics. At our knowledge, the only reported occurrence of microfossils preserved in unsilicified Archean sediments is a population of large organic-walled vesicles discovered in shales and siltstones of the 3.2 Ga Moodies Group, South Africa. (Javaux et al, Nature 2010). These have been interpreted as microfossils based on petrographic and geochemical evidence for their endogenicity and syngeneity, their carbonaceous composition, cellular morphology and ultrastructure, occurrence in populations, taphonomic features of soft wall deformation, and the geological context plausible for life, as well as lack of abiotic explanation falsifying a biological origin. Demonstrating that carbonaceous objects from Archaean rocks are truly old and truly biological is the subject of considerable debate. Abiotic processes are known to produce organics and isotopic signatures similar to life. Spheroidal pseudofossils may form as self-assembling vesicles from abiotic CM, e.g. in prebiotic chemistry experiments (Shoztak et al, 2001), from meteoritic lipids (Deamer et al, 2006), or hydrothermal fluids (Akashi et al, 1996); by artifact of maceration; by migration of abiotic or biotic CM along microfractures (VanZuilen et al, 2007) or along mineral casts (Brasier et al, 2005), or around silica spheres formed in silica-saturated water (Jones and

  19. Bones of the Earth

    Directory of Open Access Journals (Sweden)

    Jose Miguel Correa

    2014-06-01

    Full Text Available The film Bones of the Earth (Riglin, Cunninham & Correa, 2014 is an experience in collective inquiry and visual creation based on arts-based research. Starting from the meeting of different subjectivities and through dialogue, planning, shooting and editing, an audiovisual text that reconstructs a reflexive process of collective creation is built. A sense of community, on-going inquiry, connections and social commitment inform the creative process. As a result, the video’s nearly five intense minutes are a metaphor for the search for personal meaning, connection with nature and intersubjective positioning in a world that undergoes constant change.

  20. The earth's gravitational field

    Digital Repository Service at National Institute of Oceanography (India)

    Ramprasad, T.

    of the tides) have a very small effect on the apparent strength of Earth's gravity, depending on their relative positions; typical variations are 2 µm/s² (0.2 mGal) over the course of a day. Gravity measurements at sea The gravity measurements at sea... quoted as an acceleration, which in SI units is measured in m/s 2 (metres per second per second, equivalently written as m·s −2 ). It has an approximate value of 9.8 m/s 2 , which means that, ignoring air resistance, the speed of an object falling...

  1. Solid Earth: The priorities

    Science.gov (United States)

    Paquet, P.

    1991-10-01

    The European Space Agency's strategy concerning the solid Earth program is reviewed. Improvement of current knowledge of the global geopotential fields, both gravity and magnetic, was stressed as the highest priority. It was agreed that the objectives and goals of the planned Aristoteles mission correspond to this priority, and the need to realize this part of the program was stated. The interdisciplinary links of the program were identified, and it was decided that this program could make substantial contributions to research of oceans, climate and global change, atmosphere, ice and land surfaces.

  2. Japanese Rare Earth Market

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Since China cancelled export rebate in May this year,prices of magnetic materials related rare earth productscontinuously rose. Increasing production cost is largelyattributed to investment in environmental protectionequipments. Prices of Nd and Dy metals rose 20~30% over thebeginning of this year.Price of Nd was USD 11.5 - 12/Kg from USD 9/Kg at theend of 2004, up 30%. Price of Dy rose to USD 65- 70/Kg fromUSD 50/Kg early this year, up 20%. Price of Pr climbed to USD13.5 - 14/Kg from USD 11/Kg, up 30%. Pri...

  3. Abdominal wall hernia and pregnancy

    DEFF Research Database (Denmark)

    Jensen, K K; Henriksen, N A; Jorgensen, L N

    2015-01-01

    PURPOSE: There is no consensus as to the treatment strategy for abdominal wall hernias in fertile women. This study was undertaken to review the current literature on treatment of abdominal wall hernias in fertile women before or during pregnancy. METHODS: A literature search was undertaken in Pub......Med and Embase in combination with a cross-reference search of eligible papers. RESULTS: We included 31 papers of which 23 were case reports. In fertile women undergoing sutured or mesh repair, pain was described in a few patients during the last trimester of a subsequent pregnancy. Emergency surgery...... of incarcerated hernias in pregnant women, as well as combined hernia repair and cesarean section appears as safe procedures. No major complications were reported following hernia repair before or during pregnancy. The combined procedure of elective cesarean section and abdominal wall hernia repair was reported...

  4. Catalysts of plant cell wall loosening

    OpenAIRE

    Cosgrove, Daniel J.

    2016-01-01

    The growing cell wall in plants has conflicting requirements to be strong enough to withstand the high tensile forces generated by cell turgor pressure while selectively yielding to those forces to induce wall stress relaxation, leading to water uptake and polymer movements underlying cell wall expansion. In this article, I review emerging concepts of plant primary cell wall structure, the nature of wall extensibility and the action of expansins, family-9 and -12 endoglucanases, family-16 xyl...

  5. Diffusion-damped domain wall dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Varga, R; Infante, G [Inst. Phys., Fac. Sci., UPJS, Park Angelinum 9, 04154 Kosice (Slovakia); Badini-Confalonieri, G A; Vazquez, M, E-mail: rvarga@upjs.s [Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, 28049, Madrid (Spain)

    2010-01-01

    In the given work, the influence of diffusional damping on the domain wall dynamics of heat treated FeSiBP microwires is presented. Two regions of the domain wall dynamics have been found. At low applied fields diffusion damping prevails, keeping the domain wall velocity and mobility low. At higher fields, the diffusional effects are overcomed and domain wall velocity increases steeply and so does the domain wall mobility.

  6. 努尔加水库碾压式土石坝沥青混凝土心墙酸性砂砾石料的配合比试验研究%Experiment on mix proportion of acidic gravel stone for asphalt concrete core wall of rolled earth rockfill dam in Nulga reservoir

    Institute of Scientific and Technical Information of China (English)

    张庆春

    2014-01-01

    努尔加水库周围天然砂砾石料丰富,而碱性岩石料源距离坝址较远,为节省工程投资,对碾压式土石坝沥青混凝土心墙采用酸性砂砾石料进行了配合比试验研究,主要包括抗剥落剂的选型和沥青混凝土的水稳定试验,并对所推荐配合比的沥青混凝土进行了压缩、拉伸、弯曲、静三轴和渗透试验。结果表明:推荐配合比的沥青混凝土其各项物理力学性能均满足设计要求。%The natural material of gravel stone around Nulga reservoir is rich but the material of rock stone is far from dam area , in order to save the engineering investment , the paper researched mix propor-tion about asphalt concrete core wall which adopted acidic gravel stone of rolled fill dam in Nulga reser -voir.The work mainly included the selection of antistripping agent and water stability test of asphalt con -crete.It also carried out compression , stretching, bending, static triaxial and penetration test for asphalt concrete of recommended mix proportion .The results show that the various physical and mechanical prop-erties of asphalt concrete of recommended mix proportion can satisfy the requirement of design .

  7. The DEMO wall load challenge

    Science.gov (United States)

    Wenninger, R.; Albanese, R.; Ambrosino, R.; Arbeiter, F.; Aubert, J.; Bachmann, C.; Barbato, L.; Barrett, T.; Beckers, M.; Biel, W.; Boccaccini, L.; Carralero, D.; Coster, D.; Eich, T.; Fasoli, A.; Federici, G.; Firdaouss, M.; Graves, J.; Horacek, J.; Kovari, M.; Lanthaler, S.; Loschiavo, V.; Lowry, C.; Lux, H.; Maddaluno, G.; Maviglia, F.; Mitteau, R.; Neu, R.; Pfefferle, D.; Schmid, K.; Siccinio, M.; Sieglin, B.; Silva, C.; Snicker, A.; Subba, F.; Varje, J.; Zohm, H.

    2017-04-01

    For several reasons the challenge to keep the loads to the first wall within engineering limits is substantially higher in DEMO compared to ITER. Therefore the pre-conceptual design development for DEMO that is currently ongoing in Europe needs to be based on load estimates that are derived employing the most recent plasma edge physics knowledge. An initial assessment of the static wall heat load limit in DEMO infers that the steady state peak heat flux limit on the majority of the DEMO first wall should not be assumed to be higher than 1.0 MW m-2. This compares to an average wall heat load of 0.29 MW m-2 for the design {\\tt {EU}}{\\tt {~}}{\\tt {DEMO1}}{\\tt {~2015}} assuming a perfect homogeneous distribution. The main part of this publication concentrates on the development of first DEMO estimates for charged particle, radiation, fast particle (all static) and disruption heat loads. Employing an initial engineering wall design with clear optimization potential in combination with parameters for the flat-top phase (x-point configuration), loads up to 7 MW m-2 (penalty factor for tolerances etc not applied) have been calculated. Assuming a fraction of power radiated from the x-point region between 1/5 and 1/3, peaks of the total power flux density due to radiation of 0.6-0.8 MW m-2 are found in the outer baffle region. This first review of wall loads, and the associated limits in DEMO clearly underlines a significant challenge that necessitates substantial engineering efforts as well as a considerable consolidation of the associated physics basis.

  8. Wall conditioning of JET with the ITER-Like Wall

    NARCIS (Netherlands)

    Douai, D.; Brezinsek, S.; Esser, H. G.; Joffrin, E.; Keenan, T.; Knipe, S.; Kogut, D.; Lomas, P. J.; Marsen, S.; Nunes, I.; Philipps, V.; Pitts, R.A.; Shimada, M.; P. de Vries,

    2013-01-01

    The initial conditioning cycle of \\{JET\\} İLW\\} is analysed and compared with restart and operation in 2008 with a carbon dominated wall. Comparable water and oxygen decay times are observed during bake-out in both cases. Despite a 2 × 10−3 mbar l/s leak rate duri

  9. [Structure of the interalveolar wall].

    Science.gov (United States)

    Senelar, R

    1975-01-01

    The wall, which unites as well as separates two contiguous pulmonary alveoli is composed of: - a conjuntival partition, the veritable skeleton of the wall, which is occupied, to the largest extent, by capillary blood vessels. Between the capillaries, conjunctival cells are dispursed: fibrocytes, fibroblasts and histiocytes, of which some can be mobilised, transformed into macrophages, and penetrate into the alveolar lumen; - modified epithelial cells, whose very thin, vast expansions cover the conjunctival partition; - a liquid film, 0.2 mu in thickness, which separates the epithelial cells, or pneumocytes from the alveolar air. Numerous physiological implications result from this organisation.

  10. Domain wall description of superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Brito, F.A. [Departamento de Física, Universidade Federal de Campina Grande, Caixa Postal 10071, 58109-970 Campina Grande, Paraíba (Brazil); Freire, M.L.F. [Departamento de Física, Universidade Estadual da Paraíba, 58109-753 Campina Grande, Paraíba (Brazil); Mota-Silva, J.C. [Departamento de Física, Universidade Federal de Campina Grande, Caixa Postal 10071, 58109-970 Campina Grande, Paraíba (Brazil); Departamento de Física, Universidade Federal da Paraíba, Caixa Postal 5008, 58051-970 João Pessoa, Paraíba (Brazil)

    2014-01-20

    In the present work we shall address the issue of electrical conductivity in superconductors in the perspective of superconducting domain wall solutions in the realm of field theory. We take our set up made out of a dynamical complex scalar field coupled to gauge field to be responsible for superconductivity and an extra scalar real field that plays the role of superconducting domain walls. The temperature of the system is interpreted through the fact that the soliton following accelerating orbits is a Rindler observer experiencing a thermal bath.

  11. Landslides on Earth, Mars, Moon and Mercury

    Science.gov (United States)

    Brunetti, Maria Teresa; Xiao, Zhiyong; Komatsu, Goro; Peruccacci, Silvia; Fiorucci, Federica; Cardinali, Mauro; Santangelo, Michele; Guzzetti, Fausto

    2015-04-01

    Landslides play an important role in the evolution of landscapes on Earth and on other solid planets of the Solar System. On Earth, landslides have been recognized in all continents, and in subaerial and submarine environments. The spatial and temporal range of the observed slope failures is extremely large on Earth. Surface gravity is the main factor driving landslides in solid planets. Comparison of landslide characteristics, e.g. the landslide types and sizes (area, volume, fall height, length) on various planetary bodies may help in understanding the effect of surface gravity on failure initiation and propagation. In the last decades, planetary exploration missions have delivered an increasing amount of high-resolution imagery, which enables to resolve and identify morphologic structures on planetary surfaces in great detail. Here, we present three geomorphological inventories of extraterrestrial landslides on Mars, Moon and Mercury. To recognize and map the landslides on the three Solar System bodies, we adopt the same visual criteria commonly used by geomorphologists to identify terrestrial slope failures in aerial photographs or satellite images. Landslides are classified based on the morphological similarity with terrestrial ones. In particular, we focus on rock slides mapped in Valles Marineris, Mars, and along the internal walls of impact craters on the Moon and Mercury. We exploit the three inventories to study the statistical distributions of the failure sizes (e.g., area, volume, fall height, length), and we compare the results with similar distributions obtained for terrestrial landslides. We obtain indications on the effect of the different surface gravity on landslides on Earth and Mars through the relationship between the landslide area and volume on the two planets. From the analysis of the area, we hypothesize that the lack of medium size landslides on Mars is due to the absence of erosive processes, which are induced on Earth chiefly by water

  12. Modeling Earth Albedo for Satellites in Earth Orbit

    DEFF Research Database (Denmark)

    Bhanderi, Dan; Bak, Thomas

    2005-01-01

    Many satellite are influences by the Earthøs albedo, though very few model schemes exist.in order to predict this phenomenon. Earth albedo is often treated as noise, or ignored completely. When applying solar cells in the attitude hardware, Earth albedo can cause the attitude estimate to deviate...... with as much as 20 deg. Digital Sun sensors with Earth albedo correction in hardware exist, but are expensive. In addition, albedo estimates are necessary in thermal calculations and power budgets. We present a modeling scheme base4d on Eartht reflectance, measured by NASA's Total Ozone Mapping Spectrometer......, in which the Earth Probe Satellite has recorded reflectivity data daily since mid 1996. The mean of these data can be used to calculate the Earth albedo given the positions of the satellite and the Sun. Our results show that the albedo varies highly with the solar angle to the satellite's field of view...

  13. Supercurrent enhancement in Bloch domain walls.

    Science.gov (United States)

    Robinson, J W A; Chiodi, F; Egilmez, M; Halász, Gábor B; Blamire, M G

    2012-01-01

    Conventional spin-singlet Cooper pairs convert into spin-triplet pairs in ferromagnetic Josephson junctions in which the superconductor/ferromagnet interfaces (S/F) are magnetically inhomogeneous. Although much of the theoretical work describing this triplet proximity effect has considered ideal junctions with magnetic domain walls (DW) at the interfaces, in practice it is not easily possible to isolate a DW and propagate a supercurrent through it. The rare-earth magnet Gd can form a field-tuneable in-plane Bloch DW if grown between non-co-linearly aligned ferromagnets. Here we report supercurrents through magnetic Ni-Gd-Ni nanopillars: by field annealing at room temperature, we are able to modify the low temperature DW-state in Gd and this result has a striking effect on the junction supercurrent at 4.2 K. We argue that this result can only be explained in terms of the interconversion of triplet and singlet pairs, the efficiency of which depends on the magnetic helicity of the structure.

  14. Osteocytes Mechanosensing in NASA Rotating Wall Bioreactor

    Science.gov (United States)

    Spatz, Jordan; Sibonga, Jean; Wu, Honglu; Barry, Kevin; Bouxsein, Mary; Pajevic, Paola Divieti

    2010-01-01

    Osteocyte cells are the most abundant (90%) yet least understood bone cell type in the human body. Osteocytes are theorized to be the mechanosensors and transducers of mechanical load for bones, yet the biological mechanism of this action remains elusive. However, recent discoveries in osteocyte cell biology have shed light on their importance as key mechanosensing cells regulating bone remodeling and phosphate homeostasis. The aim of this project was to characterize gene expression patterns and protein levels following exposure of MLO-Y4, a very well characterized murine osteocyte-like cell line, to simulated microgravity using the NASA Rotating Wall Vessel (RWV) Bioreactor. To determine mechanistic pathways of the osteocyte's gravity sensing ability, we evaluated in vitro gene and protein expression of osteocytes exposed to simulated microgravity. Improved understanding of the fundamental mechanisms of mechano transduction at the osteocyte cellular level may lead to revolutionary treatment otions to mitigate the effects of bone loss encountered by astronauts on long duration space missions and provide tailored treatment options for maintaining bone strength of immobilized/partially paralyzed patients here on Earth.

  15. Preliminary reference Earth model

    Science.gov (United States)

    Dziewonski, Adam M.; Anderson, Don L.

    1981-06-01

    A large data set consisting of about 1000 normal mode periods, 500 summary travel time observations, 100 normal mode Q values, mass and moment of inertia have been inverted to obtain the radial distribution of elastic properties, Q values and density in the Earth's interior. The data set was supplemented with a special study of 12 years of ISC phase data which yielded an additional 1.75 × 10 6 travel time observations for P and S waves. In order to obtain satisfactory agreement with the entire data set we were required to take into account anelastic dispersion. The introduction of transverse isotropy into the outer 220 km of the mantle was required in order to satisfy the shorter period fundamental toroidal and spheroidal modes. This anisotropy also improved the fit of the larger data set. The horizontal and vertical velocities in the upper mantle differ by 2-4%, both for P and S waves. The mantle below 220 km is not required to be anisotropic. Mantle Rayleigh waves are surprisingly sensitive to compressional velocity in the upper mantle. High S n velocities, low P n velocities and a pronounced low-velocity zone are features of most global inversion models that are suppressed when anisotropy is allowed for in the inversion. The Preliminary Reference Earth Model, PREM, and auxiliary tables showing fits to the data are presented.

  16. Earth's surface heat flux

    Directory of Open Access Journals (Sweden)

    J. H. Davies

    2009-11-01

    Full Text Available We present a revised estimate of Earth's surface heat flux that is based upon a heat flow data-set with 38 347 measurements, which is 55% more than used in previous estimates. Our methodology, like others, accounts for hydrothermal circulation in young oceanic crust by utilising a half-space cooling approximation. For the rest of Earth's surface, we estimate the average heat flow for different geologic domains as defined by global digital geology maps; and then produce the global estimate by multiplying it by the total global area of that geologic domain. The averaging is done on a polygon set which results from an intersection of a 1 degree equal area grid with the original geology polygons; this minimises the adverse influence of clustering. These operations and estimates are derived accurately using methodologies from Geographical Information Science. We consider the virtually un-sampled Antarctica separately and also make a small correction for hot-spots in young oceanic lithosphere. A range of analyses is presented. These, combined with statistical estimates of the error, provide a measure of robustness. Our final preferred estimate is 47±2 TW, which is greater than previous estimates.

  17. Active Near Earth Asteroids

    Science.gov (United States)

    Jenniskens, Peter

    2015-08-01

    Past activity from Near Earth Asteroids is recorded in the meteoroid streams that cause our meteor showers. Automated meteoroid orbit surveys by photographic, low-light video, specular radar, and head-echo radar reflections are providing the first maps of meteor shower activity at different particle sizes. There are distinct differences in particle size distributions among streams. The underlaying mechanisms that created these streams are illuminated: fragmentation from spin-up or thermal stresses, meteoroid ejection by water vapor drag, and ejection of icy particles by CO and CO2 sublimation. The distribution of the meteoroid orbital elements probe the subsequent evolution by planetary perturbations and sample the range of dynamical processes to which Near Earth Asteroids are exposed. The non-stream "sporadic" meteors probe early stages in the evolution from meteoroid streams into the zodiacal dust cloud. We see that the lifetime of large meteoroids is generally not limited by collisions. Results obtained by the CAMS video survey of meteoroid orbits are compared to those from other orbit surveys. Since October 2010, over 200,000 meteoroid orbits have been measured. First results from an expansion into the southern hemisphere are also presented, as are first results from the measurement of main element compositions. Among the many streams detected so far, the Geminid and Sextantid showers stand out by having a relatively high particle density and derive from parent bodies that appear to have originated in the main belt.

  18. Copernicus Earth observation programme

    Science.gov (United States)

    Žlebir, Silvo

    European Earth observation program Copernicus is an EU-wide programme that integrates satellite data, in-situ data and modeling to provide user-focused information services to support policymakers, researchers, businesses and citizens. Land monitoring service and Emergency service are fully operational already, Atmosphere monitoring service and Marine environment monitoring service are preoperational and will become fully operational in the following year, while Climate change service and Security service are in an earlier development phase. New series of a number of dedicated satellite missions will be launched in the following years, operated by the European Space Agency and EUMETSAT, starting with Sentinel 1A satellite early this year. Ground based, air-borne and sea-borne in-situ data are provided by different international networks and organizations, EU member states networks etc. European Union is devoting a particular attention to secure a sustainable long-term operational provision of the services. Copernicus is also stated as a European Union’s most important contribution to Global Earth Observation System of Systems (GEOSS). The status and the recent development of the Copernicus programme will be presented, together with its future perspective. As Copernicus services have already demonstrated their usability and effectiveness, some interesting cases of their deployment will be presented. Copernicus free and open data policy, supported by a recently adopted EU legislative act, will also be presented.

  19. School, Earth and Imagination

    Science.gov (United States)

    Merlini, Anna; Grieco, Giovanni; Oneta, Cristina

    2015-04-01

    Geology needs to be explained and narrated to the people, focusing on the goal of making that big change of mindset that will allow individuals and the entire community to tune into the timing and the ways in which the Earth evolves. In order to achieve these important goals it is necessary to educate children from an early age so that they learn to live an environmentally friendly life. With the project "School, Earth and imagination" we introduce, with a fun and new way, notions and topics in geological and environmental sciences in schools at all levels with the final goal of improving both knowledge and sensibility for these topics into the community. Through this project we start from the children (kindergarten and primary school, ages between 3 and 8 years) because they are the foundation of our society, and without foundations nothing can be built. The "School, Earth and imagination" project wants to give the children a real opportunity to approach reality and in general the surrounding environment, for the first time even before the traditional scholastic experience, with a scientific point of view, experimenting some basic physical concepts like temperature, weight, hardness and so on directly through their body. The project is structured and developed in modules that provide a high flexibility in order to meet needs and requirements of different schools in different situations. Each module is part of the journey of Mariolino, a character that represents a very curious child who introduces basic concepts associating them to geological processes. The Journey of Mariolino, as each module, follows an insistent scheme that starts from the presentation of the problem, follows with its discussion through direct questions and ends with experimentation of the hypotheses that children have proposed to validate the solution of the problem. Each module is independent and never ends without giving children a solution and is always structured with a practical activity

  20. Cosmic Rays at Earth

    Science.gov (United States)

    Grieder, P. K. F.

    In 1912 Victor Franz Hess made the revolutionary discovery that ionizing radiation is incident upon the Earth from outer space. He showed with ground-based and balloon-borne detectors that the intensity of the radiation did not change significantly between day and night. Consequently, the sun could not be regarded as the sources of this radiation and the question of its origin remained unanswered. Today, almost one hundred years later the question of the origin of the cosmic radiation still remains a mystery. Hess' discovery has given an enormous impetus to large areas of science, in particular to physics, and has played a major role in the formation of our current understanding of universal evolution. For example, the development of new fields of research such as elementary particle physics, modern astrophysics and cosmology are direct consequences of this discovery. Over the years the field of cosmic ray research has evolved in various directions: Firstly, the field of particle physics that was initiated by the discovery of many so-called elementary particles in the cosmic radiation. There is a strong trend from the accelerator physics community to reenter the field of cosmic ray physics, now under the name of astroparticle physics. Secondly, an important branch of cosmic ray physics that has rapidly evolved in conjunction with space exploration concerns the low energy portion of the cosmic ray spectrum. Thirdly, the branch of research that is concerned with the origin, acceleration and propagation of the cosmic radiation represents a great challenge for astrophysics, astronomy and cosmology. Presently very popular fields of research have rapidly evolved, such as high-energy gamma ray and neutrino astronomy. In addition, high-energy neutrino astronomy may soon initiate as a likely spin-off neutrino tomography of the Earth and thus open a unique new branch of geophysical research of the interior of the Earth. Finally, of considerable interest are the biological

  1. Comparison of Low Earth Orbit and Geosynchronous Earth Orbits

    Science.gov (United States)

    Drummond, J. E.

    1980-01-01

    The technological, environmental, social, and political ramifications of low Earth orbits as compared to geosynchronous Earth orbits for the solar power satellite (SPS) are assessed. The capital cost of the transmitting facilities is dependent on the areas of the antenna and rectenna relative to the requirement of high efficiency power transmission. The salient features of a low orbit Earth orbits are discussed in terms of cost reduction efforts.

  2. Geochemistry of Rare Earth Elements in Aktishikan Gold Deposit,Xinjiang

    Institute of Scientific and Technical Information of China (English)

    袁峰; 周涛发; 等

    2002-01-01

    The characteristics and the models of rare earth elements in the geological bodies and the hydrothermal water balancel with the adamellite were comprehensivealy studied in Aktishikan gold deposit,Nurt area of Altay,Xinjiang,And the behavior of rare earth elements during metasomatic alteration was discussed by using the isocon method of Grant,The results show that the rare earth elements are inert during metasomatic alteration,the hydrotheraml water has no relation to the magmatic water,and the gold material sources mainly stem from the wall rock.

  3. Model test on sand retaining wall reinforced with denti-strip inclusions

    Institute of Scientific and Technical Information of China (English)

    ZHANG MengXi; ZHOU Huai

    2008-01-01

    In conventional reinforced soil structures, the reinforcements are often laid hori-zontally in the soil. In this paper, a new concept of soil reinforced with denti-strip inclusions was proposed and a series of laboratory model tests were carried out on sand retaining wall reinforced with denti-strip inclusions. Besides the horizontal displacements of the facing, the lateral earth pressures acting on vertical elements were measured. A microscopic measurement was performed to investigate the deformation and progressive failure of the sand within model retaining wall. Based on the image analytical technique, the bearing capability and interaction mecha-nism of reinforced sand retaining wall were analyzed. The model of the initial shear failure and potential failure surface were also put forward. From the ex-perimental results, it is shown that denti-strip inclusions can increase the bearing capability of retaining wall significantly and restrict the facing displacements effi-ciently, as compared with conventional horizontal reinforcement.

  4. New Bricks in the Wall

    Institute of Scientific and Technical Information of China (English)

    RONG JIAOJIAO

    2007-01-01

    @@ Whenever a newcomer enters the classroom, he points at the wall. "Look at that!" says Li Shunye, indicating a picture of something that looks a bit like a pink furry fox, only with an oversized tail. "It's a squirrel," says the 9-year-old. "I made it."

  5. Designing a Sound Reducing Wall

    Science.gov (United States)

    Erk, Kendra; Lumkes, John; Shambach, Jill; Braile, Larry; Brickler, Anne; Matthys, Anna

    2015-01-01

    Acoustical engineers use their knowledge of sound to design quiet environments (e.g., classrooms and libraries) as well as to design environments that are supposed to be loud (e.g., concert halls and football stadiums). They also design sound barriers, such as the walls along busy roadways that decrease the traffic noise heard by people in…

  6. Solar Walls for concrete renovation

    DEFF Research Database (Denmark)

    Gramkow, Lotte; Vejen, Niels Kristian; Olsen, Lars

    1996-01-01

    This repport gives a short presentation of three full-scale testing solar walls, the construction including the architectural design, materials and components, transportation and storage of solar enegy, the effect on the construction behind, statics and practical experience.The results...

  7. Overlap/Domain-wall reweighting

    CERN Document Server

    Fukaya, H; Cossu, G; Hashimoto, S; Kaneko, T; Noaki, J

    2013-01-01

    We investigate the eigenvalues of nearly chiral lattice Dirac operators constructed with five-dimensional implementations. Allowing small violation of the Ginsparg-Wilson relation, the HMC simulation is made much faster while the eigenvalues are not significantly affected. We discuss the possibility of reweighting the gauge configurations generated with domain-wall fermions to those of exactly chiral lattice fermions.

  8. Wary Eyes Monitoring Wall Street

    Science.gov (United States)

    Jacobson, Linda

    2008-01-01

    School business officials kept a close watch on the financial markets this week--and on district investment portfolios and teacher-retirement funds--as stock prices gyrated and once-sound institutions got government bailouts or crumbled into bankruptcy. While financial observers said it was too soon to predict how Wall Street's upheaval might…

  9. Solar Walls for concrete renovation

    DEFF Research Database (Denmark)

    Gramkow, Lotte; Vejen, Niels Kristian; Olsen, Lars

    1996-01-01

    This repport gives a short presentation of three full-scale testing solar walls, the construction including the architectural design, materials and components, transportation and storage of solar enegy, the effect on the construction behind, statics and practical experience.The results of the mea...

  10. Fandom and the fourth wall

    Directory of Open Access Journals (Sweden)

    Jenna Kathryn Ballinger

    2014-09-01

    Full Text Available I use the Teen Wolf fandom as an example to examine the ways social media has created a more complicated, nuanced relationship with fans. The collapse of the fourth wall between fans and The Powers That Be can have both positive and negative impacts, depending on the willingness of participants to maintain mutual respect and engage in meaningful dialogue.

  11. Shear wall ultimate drift limits

    Energy Technology Data Exchange (ETDEWEB)

    Duffey, T.A. [Duffy, (T.A.) Tijeras, NM (United States); Goldman, A. [Goldman, (A.), Sandia, Los Alamos, NM (United States); Farrar, C.R. [Los Alamos National Lab., NM (United States)

    1994-04-01

    Drift limits for reinforced-concrete shear walls are investigated by reviewing the open literature for appropriate experimental data. Drift values at ultimate are determined for walls with aspect ratios ranging up to a maximum of 3.53 and undergoing different types of lateral loading (cyclic static, monotonic static, and dynamic). Based on the geometry of actual nuclear power plant structures exclusive of containments and concerns regarding their response during seismic (i.e.,cyclic) loading, data are obtained from pertinent references for which the wall aspect ratio is less than or equal to approximately 1, and for which testing is cyclic in nature (typically displacement controlled). In particular, lateral deflections at ultimate load, and at points in the softening region beyond ultimate for which the load has dropped to 90, 80, 70, 60, and 50 percent of its ultimate value, are obtained and converted to drift information. The statistical nature of the data is also investigated. These data are shown to be lognormally distributed, and an analysis of variance is performed. The use of statistics to estimate Probability of Failure for a shear wall structure is illustrated.

  12. Wary Eyes Monitoring Wall Street

    Science.gov (United States)

    Jacobson, Linda

    2008-01-01

    School business officials kept a close watch on the financial markets this week--and on district investment portfolios and teacher-retirement funds--as stock prices gyrated and once-sound institutions got government bailouts or crumbled into bankruptcy. While financial observers said it was too soon to predict how Wall Street's upheaval might…

  13. Designing a Sound Reducing Wall

    Science.gov (United States)

    Erk, Kendra; Lumkes, John; Shambach, Jill; Braile, Larry; Brickler, Anne; Matthys, Anna

    2015-01-01

    Acoustical engineers use their knowledge of sound to design quiet environments (e.g., classrooms and libraries) as well as to design environments that are supposed to be loud (e.g., concert halls and football stadiums). They also design sound barriers, such as the walls along busy roadways that decrease the traffic noise heard by people in…

  14. Statistical characteristics of simulated walls

    Science.gov (United States)

    Demiański, M.; Doroshkevich, A. G.; Müller, V.; Turchaninov, V.

    2000-11-01

    The large-scale matter distribution in three different simulations of CDM models is investigated and compared with corresponding results of the Zel'dovich theory of non-linear gravitational instability. We show that the basic characteristics of wall-like structure elements are well described by this theory, and that they can be expressed by the cosmological parameters and a few spectral moments of the perturbation spectrum. Therefore the characteristics of such elements provide reasonable estimates of these parameters. We show that the compressed matter is relaxed and gravitationally confined and manifests itself in the existence of walls as (quasi-)stationary structure elements with a lifetime restricted by their disruption into high-density clouds. The matter distribution is investigated in both real and redshift spaces. In both cases almost the same particles form the walls, and we estimate differences in corresponding wall characteristics. The same methods are applied to several mock catalogues of `galaxies', which allows us to characterize a large-scale bias between the spatial distribution of dark matter and of simulated `galaxies'.

  15. Partial domain wall partition functions

    CERN Document Server

    Foda, O

    2012-01-01

    We consider six-vertex model configurations on a rectangular lattice with n (N) horizontal (vertical) lines, and "partial domain wall boundary conditions" defined as 1. all 2n arrows on the left and right boundaries point inwards, 2. n_u (n_l) arrows on the upper (lower) boundary, such that n_u + n_l = N - n, also point inwards, 3. all remaining n+N arrows on the upper and lower boundaries point outwards, and 4. all spin configurations on the upper and lower boundaries are summed over. To generate (n-by-N) "partial domain wall configurations", one can start from A. (N-by-N) configurations with domain wall boundary conditions and delete n_u (n_l) upper (lower) horizontal lines, or B. (2n-by-N) configurations that represent the scalar product of an n-magnon Bethe eigenstate and an n-magnon generic state on an N-site spin-1/2 chain, and delete the n lines that represent the Bethe eigenstate. The corresponding "partial domain wall partition function" is computed in construction {A} ({B}) as an N-by-N (n-by-n) det...

  16. The Influence of Wall Binders

    DEFF Research Database (Denmark)

    Rose, Jørgen

    1997-01-01

    This report is an analysis of the thermal bridge effects that occur in wall binders in masonry buildings. The effects are analyzed using a numerical calculation programme.The results are compared to the values given in the danish standard, DS418....

  17. Chuck Close: "Off the Wall."

    Science.gov (United States)

    Gardner, Michael

    2001-01-01

    Describes the planning and design process of "Off the Wall," a student-developed CD-ROM multimedia project about the life and work of artist Chuck Close-the product of a studio-based course in Learning Experiments Design at the University of Georgia. The design includes an element of gaming; text is kept sparse; navigational elements are rendered…

  18. Rethinking China's new great wall

    National Research Council Canada - National Science Library

    Ma, Zhijun; Melville, David S; Liu, Jianguo; Chen, Ying; Yang, Hongyan; Ren, Wenwei; Zhang, Zhengwang; Piersma, Theunis; Li, Bo

    2014-01-01

    ... enclosed by thousands of kilometers of seawalls, whose length exceeds that of China’s famous ancient “Great Wall” (see photos and map). This new “Great Wall,” covering 60% of the total length of coast-line along mainland China...

  19. Thin Wall Austempered Ductile Iron (TWADI

    Directory of Open Access Journals (Sweden)

    M. Górny

    2009-07-01

    Full Text Available In this paper the analysis of thin walled castings made of ductile iron is considered. It is shown that thin wall austempered ductile iron can be obtained by means of short-term heat treatment of thin wall castings without addition of alloying elements. Metallographic examinations of 2 mm thin walled castings along with casting with thicker wall thickness (20x28 mm after different austempring conditions are presented. It has been proved that short-term heat treatment amounted 20 minutes of austenitizing at 880 oC followed by holding at 400 oC for 5 minutes causes ausferrite matrix in 2 mm wall thickness castings, while casting with thicker wall thickness remain untransformed and martensite is still present in a matrix. Finally there are shown that thin wall ductile iron is an excellent base material for austempering heat treatments. As a result high mechanical properties received in thin wall plates made of austempered ductile iron.

  20. Structural Responses and Finite Element Modeling of Hakka Tulou Rammed Earth Structures

    Science.gov (United States)

    Sranislawski, Daniel

    Hakka Tulous are rammed earth structures that have survived the effects of aging and natural elements upwards of even over a thousand years. These structures have housed the Hakka people of the Fujian Province, China in natural yet modern housing that has provided benefits over newer building materials. The key building material, rammed earth, which is used for the walls of the Hakka Tulou structures, has provided structural stability along with thermal comfort to the respective inhabitants of the Hakka Tulous. Through material testing and analysis this study has examined how the Tulou structures have maintained their structural stability while also providing thermal comfort. Reports of self healing cracks in the rammed earth walls were also analyzed for their validity in this study. The study has found that although the story of the self healing crack cannot be validated, there is reason to believe that with the existence of lime, some type of autogenous healing could occur on a small scale. The study has also found, through the use of nondestructive testing, that both the internal wooden systems (flooring, roof, and column support) and the rammed earth walls, are still structurally sound. Also, rammed earth's high thermal mass along with the use of sufficient shading has allowed for a delay release of heat energy from the walls of the Tulous, thus providing thermal comfort that can be felt during both night and day temperatures. The Hakka Tulou structures have been found to resist destruction from natural disasters such as strong earthquakes even when more modern construction has not. Through finite element modeling, this study has shown that the high volume of rammed earth used in the construction of the Hakka Tulous helps dissipate lateral force energy into much lower stresses for the rammed earth wall. This absorption of lateral force energy allows the rammed earth structures to survive even the strongest of earthquakes experienced in the region. The Hakka

  1. PPOOLEX experiments on wall condensation

    Energy Technology Data Exchange (ETDEWEB)

    Laine, J.; Puustinen, M. (Lappeenranta Univ. of Technology, Nuclear Safety Research Unit (Finland))

    2009-08-15

    This report summarizes the results of the wall condensation experiments carried out in December 2008 and January 2009 with the scaled down PPOOLEX test facility designed and constructed at Lappeenranta University of Technology. Steam was blown into the dry well compartment and from there through a DN200 blowdown pipe to the condensation pool. Altogether five experiments, each consisting of several blows, were carried out. The main purpose of the experiment series was to study wall condensation phenomenon inside the dry well compartment while steam is discharged through it into the condensation pool and to produce comparison data for CFD calculations at VTT. The PPOOLEX test facility is a closed stainless steel vessel divided into two compartments, dry well and wet well. For the wall condensation experiments the test facility was equipped with a system for collecting and measuring the amount of condensate from four different wall segments of the dry well compartment. A thermo graphic camera was used in a couple of experiments for filming the outside surface of the dry well wall. The effect of the initial temperature level of the dry well structures and of the steam flow rate for the accumulation of condensate was studied. The initial temperature level of the dry well structures varied from 23 to 99 deg. C. The steam flow rate varied from 90 to 690 g/s and the temperature of incoming steam from 115 to 160 deg. C. During the initial phase of steam discharge the accumulation of condensate was strongly controlled by the temperature level of the dry well structures; the lower the initial temperature level was the more condensate was accumulated. As the dry well structural temperatures increased the condensation process slowed down. Most of the condensate usually accumulated during the first 200 seconds of the discharge. However, the condensation process never completely stopped because a small temperature difference remained between the dry well atmosphere and inner wall

  2. China rare earth market review

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    June 20-30 2012 Affected by a sustained slump in the demand from downstream industries, rare earth market remained flat recently. There were not many inquiries for rare earth products in the spot market. Consumers lacked of confidence in the future market. As for the downstream industries, the market of NdFeB magnetic materials and phosphors were in the doldrums. Ceramic, catalyst and polishing powder industries maintained weak. Affected by the global economy, export market of rare earth was weak.

  3. Cosmic rays and Earth's climate

    DEFF Research Database (Denmark)

    Svensmark, Henrik

    2000-01-01

    During the last solar cycle the Earth's cloud cover underwent a modulation in phase with the cosmic ray flux. Assuming that there is a causal relationship between the two, it is expected and found that the Earth's temperature follows more closely decade variations in cosmic ray flux than other...... solar activity parameters. If the relationship is real the state of the Heliosphere affects the Earth's climate....

  4. China rare earth market review

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Rare earth market remained weak recently. Dealings of light and heavy rare earth products were sluggish. Demand for didymium and dysprosium related products was soft and purchasers were not interested in replenishing their stocks. The market of NdFeB magnetic materials and phosphors remained inactive. Meanwhile, ceramic, catalyst and polishing powder industries were weak. Affected by global economical recession, export market of rare earth remained weak.

  5. China rare earth market review

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Rare earth market was weak recently. There was still no sign of recovery in NdFeB magnetic materials and phosphors market. The market of ceramic, catalyst and polishing powder were in the doldrums. Rare earth deep processing enterprisers hesitated to purchase rare earth products and considered that there was room for further price reduction. Global economy slowed down and there was no sign of improvement yet. The export market was sluggish and transactions were inactive.

  6. China Rare Earth Market Review

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Rare earth market was relatively stable recently. There was not much change to the quotations by suppliers. Inquiries for most products increased in spot market and so did to the transactions. Recently, rare earth special invoices attracted the attention in the industry again. It is likely to result in price rise of many rare earth products if the special invoice system can put into effect in the near term.

  7. China rare earth market review

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    November 1-10, 2012 Some key rare earth producers had paused production since the last ten day period of October in order to retain normal production and market order and stabilize rare earth prices. The production suspension measure by the plants together with severe cracking down on illegal mining by the government had some influence on sluggish market recently. Data showed rapid price increase of major rare earth products after sharp decline previously.

  8. Earth's early biosphere

    Science.gov (United States)

    Des Marais, D. J.

    1998-01-01

    Understanding our own early biosphere is essential to our search for life elsewhere, because life arose on Earth very early and rocky planets shared similar early histories. The biosphere arose before 3.8 Ga ago, was exclusively unicellular and was dominated by hyperthermophiles that utilized chemical sources of energy and employed a range of metabolic pathways for CO2 assimilation. Photosynthesis also arose very early. Oxygenic photosynthesis arose later but still prior to 2.7 Ga. The transition toward the modern global environment was paced by a decline in volcanic and hydrothermal activity. These developments allowed atmospheric O2 levels to increase. The O2 increase created new niches for aerobic life, most notably the more advanced Eukarya that eventually spawned the megascopic fauna and flora of our modern biosphere.

  9. Earth Abides Arsenic Biotransformations

    Science.gov (United States)

    Zhu, Yong-Guan; Yoshinaga, Masafumi; Zhao, Fang-Jie; Rosen, Barry P.

    2014-05-01

    Arsenic is the most prevalent environmental toxic element and causes health problems throughout the world. The toxicity, mobility, and fate of arsenic in the environment are largely determined by its speciation, and arsenic speciation changes are driven, at least to some extent, by biological processes. In this article, biotransformation of arsenic is reviewed from the perspective of the formation of Earth and the evolution of life, and the connection between arsenic geochemistry and biology is described. The article provides a comprehensive overview of molecular mechanisms of arsenic redox and methylation cycles as well as other arsenic biotransformations. It also discusses the implications of arsenic biotransformation in environmental remediation and food safety, with particular emphasis on groundwater arsenic contamination and arsenic accumulation in rice.

  10. Earth Abides Arsenic Biotransformations

    Science.gov (United States)

    Zhu, Yong-Guan; Yoshinaga, Masafumi; Zhao, Fang-Jie; Rosen, Barry P.

    2015-01-01

    Arsenic is the most prevalent environmental toxic element and causes health problems throughout the world. The toxicity, mobility, and fate of arsenic in the environment are largely determined by its speciation, and arsenic speciation changes are driven, at least to some extent, by biological processes. In this article, biotransformation of arsenic is reviewed from the perspective of the formation of Earth and the evolution of life, and the connection between arsenic geochemistry and biology is described. The article provides a comprehensive overview of molecular mechanisms of arsenic redox and methylation cycles as well as other arsenic biotransformations. It also discusses the implications of arsenic biotransformation in environmental remediation and food safety, with particular emphasis on groundwater arsenic contamination and arsenic accumulation in rice. PMID:26778863

  11. One Day on Earth

    CERN Multimedia

    2011-01-01

    In collaboration with the CineGlobe Film Festival, the One Day on Earth global film project invites you to share your story of scientific inspiration, scientific endeavors and technological advancement on 11 November 2011 (11.11.11).   Technology in the 21st century continuously inspires us to re-imagine the world. From outer-space to cyberspace, new ideas that we hope will improve the lives of future generations keep us in a state of change. However, these new technologies may alter the nature of our shared existence in ways not yet known. On 11.11.11, we invite you to record the exciting ways that science is a part of your life, together with people around the world who will be documenting their lives on this day of global creation. See www.onedayonearth.org for details on how to participate.

  12. Earth Gravitational Model 2020

    Science.gov (United States)

    Barnes, D.; Factor, J. K.; Holmes, S. A.; Ingalls, S.; Presicci, M. R.; Beale, J.; Fecher, T.

    2015-12-01

    The National Geospatial-Intelligence Agency [NGA], in conjunction with its U.S. and international partners, has begun preliminary work on its next Earth Gravitational Model, to replace EGM2008. The new 'Earth Gravitational Model 2020' [EGM2020] has an expected public release date of 2020, and will likely retain the same harmonic basis and resolution as EGM2008. As such, EGM2020 will be essentially an ellipsoidal harmonic model up to degree (n) and order (m) 2159, but will be released as a spherical harmonic model to degree 2190 and order 2159. EGM2020 will benefit from new data sources and procedures. Updated satellite gravity information from the GOCE and GRACE mission, will better support the lower harmonics, globally. Multiple new acquisitions (terrestrial, airborne and shipborne) of gravimetric data over specific geographical areas, will provide improved global coverage and resolution over the land, as well as for coastal and some ocean areas. Ongoing accumulation of satellite altimetry data as well as improvements in the treatment of this data, will better define the marine gravity field, most notably in polar and near-coastal regions. NGA and partners are evaluating different approaches for optimally combining the new GOCE/GRACE satellite gravity models with the terrestrial data. These include the latest methods employing a full covariance adjustment. NGA is also working to assess systematically the quality of its entire gravimetry database, towards correcting biases and other egregious errors where possible, and generating improved error models that will inform the final combination with the latest satellite gravity models. Outdated data gridding procedures have been replaced with improved approaches. For EGM2020, NGA intends to extract maximum value from the proprietary data that overlaps geographically with unrestricted data, whilst also making sure to respect and honor its proprietary agreements with its data-sharing partners.

  13. Theory of Earth

    Science.gov (United States)

    Anderson, D. L.

    2014-12-01

    Earth is an isolated, cooling planet that obeys the 2nd law. Interior dynamics is driven from the top, by cold sinking slabs. High-resolution broad-band seismology and geodesy has confirmed that mantle flow is characterized by narrow downwellings and ~20 broad slowly rising updrafts. The low-velocity zone (LVZ) consists of a hot melange of sheared peridotite intruded with aligned melt-rich lamellae that are tapped by intraplate volcanoes. The high temperature is a simple consequence of the thermal overshoot common in large bodies of convecting fluids. The transition zone consists of ancient eclogite layers that are displaced upwards by slabs to become broad passive, and cool, ridge feeding updrafts of ambient mantle. The physics that is overlooked in canonical models of mantle dynamics and geochemistry includes; the 2nd law, convective overshoots, subadiabaticity, wave-melt interactions, Archimedes' principle, and kinetics (rapid transitions allow stress-waves to interact with melting and phase changes, creating LVZs; sluggish transitions in cold slabs keep eclogite in the TZ where it warms up by extracting heat from mantle below 650 km, creating the appearance of slab penetration). Canonical chemical geodynamic models are the exact opposite of physics and thermodynamic based models and of the real Earth. A model that results from inverting the assumptions regarding initial and boundary conditions (hot origin, secular cooling, no external power sources, cooling internal boundaries, broad passive upwellings, adiabaticity and whole-mantle convection not imposed, layering and self-organization allowed) results in a thick refractory-yet-fertile surface layer, with ancient xenoliths and cratons at the top and a hot overshoot at the base, and a thin mobile D" layer that is an unlikely plume generation zone. Accounting for the physics that is overlooked, or violated (2nd law), in canonical models, plus modern seismology, undermines the assumptions and conclusions of these

  14. Sun, Earth and Sky

    Science.gov (United States)

    Lang, Kenneth R.

    1995-01-01

    The Sun is enveloped by a hot, tenuous million-degree corona that expands to create a continuous solar wind that sweeps past all the planets and fills the heliosphere. The solar wind is modulated by strong gusts that are initiated by powerful explosions on the Sun, including solar flares and coronal mass ejections. This dynamic, invisible outer atmosphere of the Sun is currently under observation with the soft X-ray telescope aboard the Yohkoh spacecraft, whose results are presented. We also show observations from the Ulysses spacecraft that is now passing over the solar pole, sampling the solar wind in this region for the first time. Two other spacecraft, Voyager 1 and 2, have recently detected the outer edge of the invisible heliosphere, roughly halfway to the nearest star. Magnetic solar activity, the total radiative output from the Sun, and the Earth's mean global surface temperature all vary with the 11-year sunspot cycle in which the total number of sunspots varies from a maximum to a minimum and back to a maximum again in about 11 years. The terrestrial magnetic field hollows out a protective magnetic cavity, called the magnetosphere, within the solar wind. This protection is incomplete, however, so the Sun feeds an unseen world of high-speed particles and magnetic fields that encircle the Earth in space. These particles endanger spacecraft and astronauts, and also produce terrestrial aurorae. An international flotilla of spacecraft is now sampling the weak points in this magnetic defense. Similar spacecraft have also discovered a new radiation belt, in addition to the familiar Van Allen belts, except fed by interstellar ions instead of electrons and protons from the Sun.

  15. China rare earth market review

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    October 21-31,2012 Recently, dealings of rare earth remained stagnant. Consumers hesitated to increase their stocks for the fear of further decline in rare earth prices. It was difficult for suppliers to sell products and they had reduced quotations to attract buyers. It did not show demand from end users could rebound in short terms. Dealings of rare earth products in spot market were few. The market of NdFeB magnetic materials, phosphors, catalysts, polishing powders and ceramics remained sluggish. There was no sign of picking up in world economy. Export market of rare earths maintained inactive.

  16. The earth and the moon

    CERN Document Server

    Elkins-Tanton, Linda T

    2010-01-01

    The moon is the only body in the solar system outside of the Earth that has been visited by humans. More than 440 pounds of lunar material are brought by NASA and Soviet space missions to Earth for study. The information gleaned about the moon from this relatively small pile of rocks is mind-boggling and stands as the greatest proof that Martian planetary science would be greatly enhanced by returning samples to Earth. Compositional studies of lunar rocks show that the moon and the Earth are made of similar material, and because lunar material has not been reworked through erosion and plate te

  17. China Rare Earth Market Review

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Rare earth market remained sluggish and quiet holistically recently. Didymium-related market was quiet and the consumers were hesitating in replenishing their inventories. Inquiries for dysprosium-related products were few and the transactions were inactive, Demand for europium oxide (99.99%) was weak and the trade was far from brisk. Baogang Rare Earth suspended production, which has a positive effect in stabilizing the whole rare earth market. But prices of rare earth products did not go up rapidly. This means there were still large inventories in the market.

  18. The thick left ventricular wall of the giraffe heart normalises wall tension, but limits stroke volume and cardiac output.

    Science.gov (United States)

    Smerup, Morten; Damkjær, Mads; Brøndum, Emil; Baandrup, Ulrik T; Kristiansen, Steen Buus; Nygaard, Hans; Funder, Jonas; Aalkjær, Christian; Sauer, Cathrine; Buchanan, Rasmus; Bertelsen, Mads Frost; Østergaard, Kristine; Grøndahl, Carsten; Candy, Geoffrey; Hasenkam, J Michael; Secher, Niels H; Bie, Peter; Wang, Tobias

    2016-02-01

    Giraffes--the tallest extant animals on Earth--are renowned for their high central arterial blood pressure, which is necessary to secure brain perfusion. Arterial pressure may exceed 300 mmHg and has historically been attributed to an exceptionally large heart. Recently, this has been refuted by several studies demonstrating that the mass of giraffe heart is similar to that of other mammals when expressed relative to body mass. It thus remains unexplained how the normal-sized giraffe heart generates such massive arterial pressures. We hypothesized that giraffe hearts have a small intraventricular cavity and a relatively thick ventricular wall, allowing for generation of high arterial pressures at normal left ventricular wall tension. In nine anaesthetized giraffes (495±38 kg), we determined in vivo ventricular dimensions using echocardiography along with intraventricular and aortic pressures to calculate left ventricular wall stress. Cardiac output was also determined by inert gas rebreathing to provide an additional and independent estimate of stroke volume. Echocardiography and inert gas-rebreathing yielded similar cardiac outputs of 16.1±2.5 and 16.4±1.4 l min(-1), respectively. End-diastolic and end-systolic volumes were 521±61 ml and 228±42 ml, respectively, yielding an ejection fraction of 56±4% and a stroke volume of 0.59 ml kg(-1). Left ventricular circumferential wall stress was 7.83±1.76 kPa. We conclude that, relative to body mass, a small left ventricular cavity and a low stroke volume characterizes the giraffe heart. The adaptations result in typical mammalian left ventricular wall tensions, but produce a lowered cardiac output.

  19. Through-the-wall radar imaging

    CERN Document Server

    Amin, Moeness G

    2011-01-01

    Wall Attenuation and Dispersion, A. Hussein Muqaibel, M.A. Alsunaidi, Nuruddeen M. Iya, and A. Safaai-JaziAntenna Elements, Arrays, and Systems for Through-the-Wall Radar Imaging, A. Hoorfar and A. FathyBeamforming for Through-the-Wall Radar Imaging, G. Alli and D. DiFilippoImage and Localization of Behind-the-Wall Targets Using Collocated and Distributed Apertures, Y.D. Zhang and A. HuntConventional and Emerging Waveforms for Detection and Imaging of Targets behind Walls, F. Ahmad and R.M. NarayananInverse Scattering Approaches in Through-the-Wall Imaging, K. Sarabandi, M. Thiel, M. Dehmollai

  20. Uplink Power Control For Earth/Satellite/Earth Communication

    Science.gov (United States)

    Chakraborty, Dayamoy

    1994-01-01

    Proposed control subsystem adjusts power radiated by uplink transmitter in Earth station/satellite relay station/ Earth station communication system. Adjustments made to compensate for anticipated changes in attenuation by rain. Raw input is a received downlink beacon singal, amplitude of which affected not only by rain fade but also by scintillation, attenuation in atmospheric gases, and diurnal effects.

  1. Near-wall behavior of turbulent wall-bounded flows

    Energy Technology Data Exchange (ETDEWEB)

    Buschmann, Matthias H. [Institut fuer Luft- und Kaeltetechnik Dresden, Bertolt-Brecht-Allee 20, 01309 Dresden (Germany)], E-mail: Matthias.Buschmann@ilkdresden.de; Indinger, Thomas [Technische Universitaet Muenchen, Institute of Aerodynamics, Boltzmannstr., 15, 85748 Garching (Germany); Gad-el-Hak, Mohamed [Virginia Commonwealth University, Richmond, VA 23284-3015 (United States)

    2009-10-15

    A data base compiling a large number of results from direct numerical simulations and physical experiments is used to explore the properties of shear and normal Reynolds stresses very close to the wall of turbulent channel/pipe flows and boundary layers. Three types of scaling are mainly investigated, classical inner, standard mixed, and pure outer scaling. The study focuses on the wall behavior, the location and the value of the peak Reynolds shear stress and the three normal stresses. A primary observation is that all of these parameters show a significant Karman number dependence. None of the scalings investigated works in an equal manner for all parameters. It is found that the respective first-order Taylor series expansion satisfactorily represents each stress only in a surprisingly thin layer very close to the wall. In some cases, a newly introduced scaling based on u{sub {tau}}{sup 3/2}u{sub e}{sup 1/2} offers a remedy.

  2. China's rare-earth industry

    Science.gov (United States)

    Tse, Pui-Kwan

    2011-01-01

    Introduction China's dominant position as the producer of over 95 percent of the world output of rare-earth minerals and rapid increases in the consumption of rare earths owing to the emergence of new clean-energy and defense-related technologies, combined with China's decisions to restrict exports of rare earths, have resulted in heightened concerns about the future availability of rare earths. As a result, industrial countries such as Japan, the United States, and countries of the European Union face tighter supplies and higher prices for rare earths. This paper briefly reviews China's rare-earth production, consumption, and reserves and the important policies and regulations regarding the production and trade of rare earths, including recently announced export quotas. The 15 lanthanide elements-lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium (atomic numbers 57-71)-were originally known as the rare earths from their occurrence in oxides mixtures. Recently, some researchers have included two other elements-scandium and yttrium-in their discussion of rare earths. Yttrium (atomic number 39), which lies above lanthanum in transition group III of the periodic table and has a similar 3+ ion with a noble gas core, has both atomic and ionic radii similar in size to those of terbium and dysprosium and is generally found in nature with lanthanides. Scandium (atomic number 21) has a smaller ionic radius than yttrium and the lanthanides, and its chemical behavior is intermediate between that of aluminum and the lanthanides. It is found in nature with the lanthanides and yttrium. Rare earths are used widely in high-technology and clean-energy products because they impart special properties of magnetism, luminescence, and strength. Rare earths are also used in weapon systems to obtain the same properties.

  3. ORIGINAL ARTICLE Sonographic gallbladder wall thickness in ...

    African Journals Online (AJOL)

    gallbladder wall thickness and the subjects' age, sex, height and weight .... sex distributions and mean height and weights were calculated. Results were expressed .... establishing of a population-based US gallbladder wall thickness so that.

  4. Teaching Waves with Google Earth

    Science.gov (United States)

    Logiurato, Fabrizio

    2012-01-01

    Google Earth is a huge source of interesting illustrations of various natural phenomena. It can represent a valuable tool for science education, not only for teaching geography and geology, but also physics. Here we suggest that Google Earth can be used for introducing in an attractive way the physics of waves. (Contains 9 figures.)

  5. Introductory mathematics for earth scientists

    CERN Document Server

    Yang, Xin-She

    2009-01-01

    Any quantitative work in earth sciences requires mathematical analysis and mathematical methods are essential to the modelling and analysis of the geological, geophysical and environmental processes involved. This book provides an introduction to the fundamental mathematics that all earth scientists need.

  6. Polar Misunderstandings: Earth's Dynamic Dynamo

    Science.gov (United States)

    DiSpezio, Michael A.

    2011-01-01

    This article discusses the movement of Earth's north and south poles. The Earth's poles may be a bit more complex and dynamic than what many students and teachers believe. With better understanding, offer them up as a rich landscape for higher-level critical analysis and subject integration. Possible curriculum tie-ins include magnets, Earth…

  7. Teaching Waves with Google Earth

    Science.gov (United States)

    Logiurato, Fabrizio

    2012-01-01

    Google Earth is a huge source of interesting illustrations of various natural phenomena. It can represent a valuable tool for science education, not only for teaching geography and geology, but also physics. Here we suggest that Google Earth can be used for introducing in an attractive way the physics of waves. (Contains 9 figures.)

  8. Brick Walls on the Brane

    CERN Document Server

    Medved, A J M

    2002-01-01

    The so-called ``brick-wall model'' is a semi-classical approach that has been used to explain black hole entropy in terms of thermal matter fields. Here, we apply the brick-wall formalism to thermal bulk fields in a Randall-Sundrum brane world scenario. In this case, the black hole entity is really a string-like object in the anti-de Sitter bulk, while appearing as a Schwarzchild black hole to observers living on the brane. In spite of these exotic circumstances, we establish that the Bekenstein-Hawking entropy law is preserved. Although a similar calculation was recently considered in the literature, this prior work invoked a simplifying assumption (which we avoid) that can not be adequately justified.

  9. Brick walls on the brane

    Energy Technology Data Exchange (ETDEWEB)

    Medved, A J M [Department of Physics and Theoretical Physics Institute, University of Alberta, Edmonton (Canada)

    2002-01-21

    The so-called 'brick-wall model' is a semiclassical approach that has been used to explain black hole entropy in terms of thermal matter fields. Here, we apply the brick-wall formalism to thermal bulk fields in a Randall-Sundrum brane world scenario. In this case, the black hole entity is really a string-like object in the anti-de Sitter bulk, while appearing as a Schwarzchild black hole to observers living on the brane. In spite of these exotic circumstances, we establish that the Bekenstein-Hawking entropy law is preserved. Although a similar calculation was recently considered in the literature, this prior study invoked a simplifying assumption (which we avoid) that cannot be adequately justified.

  10. Creating universes with thick walls

    CERN Document Server

    Ulvestad, Andrew

    2012-01-01

    We study the dynamics of a spherically symmetric false vacuum bubble embedded in a true vacuum region separated by a "thick wall", which is generated by a scalar field in a quartic potential. We study the "Farhi-Guth-Guven" (FGG) quantum tunneling process by constructing numerical solutions relevant to this process. The ADM mass of the spacetime is calculated, and we show that there is a lower bound that is a significant fraction of the scalar field mass. We argue that the zero mass solutions used to by some to argue against the physicality of the FGG process are artifacts of the thin wall approximation used in earlier work. We argue that the zero mass solutions should not be used to question the viability of the FGG process.

  11. Low Earth Orbiter: Terminal

    Science.gov (United States)

    Kremer, Steven E.; Bundick, Steven N.

    1999-01-01

    In response to the current government budgetary environment that requires the National Aeronautics and Space Administration (NASA) to do more with less, NASA/Goddard Space Flight Center's Wallops Flight Facility has developed and implemented a class of ground stations known as a Low Earth Orbiter-Terminal (LEO-T). This development thus provides a low-cost autonomous ground tracking service for NASA's customers. More importantly, this accomplishment provides a commercial source to spacecraft customers around the world to purchase directly from the company awarded the NASA contract to build these systems. A few years ago, NASA was driven to provide more ground station capacity for spacecraft telemetry, tracking, and command (TT&C) services with a decreasing budget. NASA also made a decision to develop many smaller, cheaper satellites rather than a few large spacecraft as done in the past. In addition, university class missions were being driven to provide their own TT&C services due to the increasing load on the NASA ground-tracking network. NASA's solution for this ever increasing load was to use the existing large aperture systems to support those missions requiring that level of performance and to support the remainder of the missions with the autonomous LEO-T systems. The LEO-T antenna system is a smaller, cheaper, and fully autonomous unstaffed system that can operate without the existing NASA support infrastructure. The LEO-T provides a low-cost, reliable space communications service to the expanding number of low-earth orbiting missions around the world. The system is also fostering developments that improve cost-effectiveness of autonomous-class capabilities for NASA and commercial space use. NASA has installed three LEO-T systems. One station is at the University of Puerto Rico, the second system is installed at the Poker Flat Research Range near Fairbanks, Alaska, and the third system is installed at NASA's Wallops Flight Facility in Virginia. This paper

  12. Thermodynamics of the Earth

    Energy Technology Data Exchange (ETDEWEB)

    Stacey, Frank D [CSIRO Exploration and Mining, PO Box 883, Kenmore, Qld. 4069 (Australia)], E-mail: Frank.Stacey@csiro.au

    2010-04-15

    Applications of elementary thermodynamic principles to the dynamics of the Earth lead to robust, quantitative conclusions about the tectonic effects that arise from convection. The grand pattern of motion conveys deep heat to the surface, generating mechanical energy with a thermodynamic efficiency corresponding to that of a Carnot engine operating over the adiabatic temperature gradient between the heat source and sink. Referred to the total heat flux derived from the Earth's silicate mantle, the efficiency is 24% and the power generated, 7.7 x 10{sup 12} W, causes all the material deformation apparent as plate tectonics and the consequent geological processes. About 3.5% of this is released in seismic zones but little more than 0.2% as seismic waves. Even major earthquakes are only localized hiccups in this motion. Complications that arise from mineral phase transitions can be used to illuminate details of the motion. There are two superimposed patterns of convection, plate subduction and deep mantle plumes, driven by sources of buoyancy, negative and positive respectively, at the top and bottom of the mantle. The patterns of motion are controlled by the viscosity contrasts (>10{sup 4} : 1) at these boundaries and are self-selected as the least dissipative mechanisms of heat transfer for convection in a body with very strong viscosity variation. Both are subjects of the thermodynamic efficiency argument. Convection also drives the motion in the fluid outer core that generates the geomagnetic field, although in that case there is an important energy contribution by compositional separation, as light solute is rejected by the solidifying inner core and mixed into the outer core, a process referred to as compositional convection. Uncertainty persists over the core energy balance because thermal conduction is a drain on core energy that has been a subject of diverse estimates, with attendant debate over the need for radiogenic heat in the core. The geophysical

  13. Walled-off pancreatic necrosis

    Institute of Scientific and Technical Information of China (English)

    Michael; Stamatakos; Charikleia; Stefanaki; Konstantinos; Kontzoglou; Spyros; Stergiopoulos; Georgios; Giannopoulos; Michael; Safioleas

    2010-01-01

    Walled-off pancreatic necrosis (WOPN), formerly known as pancreatic abscess is a late complication of acute pancreatitis. It can be lethal, even though it is rare. This critical review provides an overview of the continually expanding knowledge about WOPN, by review of current data from references identified in Medline and PubMed, to September 2009, using key words, such as WOPN, infected pseudocyst, severe pancreatitis, pancreatic abscess, acute necrotizing pancreatitis (ANP), pancreas, inflammation and al...

  14. Droplets Evaporation on Heated Wall

    Directory of Open Access Journals (Sweden)

    Misyura S. Y.

    2015-01-01

    Full Text Available Various modes of evaporation in a wide range of droplet sizes and wall temperatures have been investigated in the present work. For any initial drop size there are three typical boiling regime: 1 the nucleate boiling; 2 the transitional regime; 3 the film boiling. The width of the transition region of boiling crisis increases with increasing the initial volume V0. Evaporation of large droplets at high superheat depends on the initial droplet shape.

  15. Statistical characteristics of simulated walls

    OpenAIRE

    Demianski, M.; Doroshkevich, A. G.; V.; Mueller; Turchaninov, V.

    2000-01-01

    The large scale matter distribution in three different simulations of CDM models is investigated and compared with corresponding results of the Zel'dovich theory of nonlinear gravitational instability. We show that the basic characteristics of wall-like structure elements are well described by this theory, and that they can be expressed by the cosmological parameters and a few spectral moments of the perturbation spectrum. Therefore the characteristics of such elements provide reasonable esti...

  16. Phase stable rare earth garnets

    Energy Technology Data Exchange (ETDEWEB)

    Kuntz, Joshua D.; Cherepy, Nerine J.; Roberts, Jeffery J.; Payne, Stephen A.

    2013-06-11

    A transparent ceramic according to one embodiment includes a rare earth garnet comprising A.sub.hB.sub.iC.sub.jO.sub.12, where h is 3.+-.10%, i is 2.+-.10%, and j is 3.+-.10%. A includes a rare earth element or a mixture of rare earth elements, B includes at least one of aluminum, gallium and scandium, and C includes at least one of aluminum, gallium and scandium, where A is at a dodecahedral site of the garnet, B is at an octahedral site of the garnet, and C is at a tetrahedral site of the garnet. In one embodiment, the rare earth garment has scintillation properties. A radiation detector in one embodiment includes a transparent ceramic as described above and a photo detector optically coupled to the rare earth garnet.

  17. Intrinsic Hydrophobicity of Rammed Earth

    Science.gov (United States)

    Holub, M.; Stone, C.; Balintova, M.; Grul, R.

    2015-11-01

    Rammed earth is well known for its vapour diffusion properties, its ability to regulate humidity within the built environment. Rammed earth is also an aesthetically iconic material such as marble or granite and therefore is preferably left exposed. However exposed rammed earth is often coated with silane/siloxane water repellents or the structure is modified architecturally (large roof overhangs) to accommodate for the hydrophilic nature of the material. This paper sets out to find out optimal hydrophobicity for rammed earth based on natural composite fibres and surface coating without adversely affecting the vapour diffusivity of the material. The material is not required to be waterproof, but should resist at least driving rain. In order to evaluate different approaches to increase hydrophobicity of rammed earth surface, peat fibres and four types of repellents were used.

  18. Tube wall thickness measurement apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Lagasse, P.R.

    1985-06-21

    An apparatus for measuring the thickness of a tube's wall for the tube's entire length and radius by determining the deviation of the tube wall thickness from the known thickness of a selected standard item. The apparatus comprises a base and a first support member having first and second ends. The first end is connected to the base and the second end is connected to a spherical element. A second support member is connected to the base and spaced apart from the first support member. A positioning element is connected to and movable relative to the second support member. An indicator is connected to the positioning element and is movable to a location proximate the spherical element. The indicator includes a contact ball for first contacting the selected standard item and holding it against the spherical element. The contact ball then contacts the tube when the tube is disposed about the spherical element. The indicator includes a dial having a rotatable needle for indicating the deviation of the tube wall thickness from the thickness of the selected standard item.

  19. Tube wall thickness measurement apparatus

    Science.gov (United States)

    Lagasse, P.R.

    1985-06-21

    An apparatus for measuring the thickness of a tube's wall for the tube's entire length and radius by determining the deviation of the tube wall thickness from the known thickness of a selected standard item. The apparatus comprises a base and a first support member having first and second ends. The first end is connected to the base and the second end is connected to a spherical element. A second support member is connected to the base and spaced apart from the first support member. A positioning element is connected to and movable relative to the second support member. An indicator is connected to the positioning element and is movable to a location proximate the spherical element. The indicator includes a contact ball for first contacting the selected standard item and holding it against the spherical element. The contact ball then contacts the tube when the tube is disposed about the spherical element. The indicator includes a dial having a rotatable needle for indicating the deviation of the tube wall thickness from the thickness of the selected standard item.

  20. Tube wall thickness measurement apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Lagasse, Paul R. (Santa Fe, NM)

    1987-01-01

    An apparatus for measuring the thickness of a tube's wall for the tube's entire length and circumference by determining the deviation of the tube wall thickness from the known thickness of a selected standard item. The apparatus comprises a base and a first support member having first and second ends. The first end is connected to the base and the second end is connected to a spherical element. A second support member is connected to the base and spaced apart from the first support member. A positioning element is connected to and movable relative to the second support member. An indicator is connected to the positioning element and is movable to a location proximate the spherical element. The indicator includes a contact ball for first contacting the selected standard item and holding it against the spherical element. The contact ball then contacts the tube when the tube is disposed about the spherical element. The indicator includes a dial having a rotatable needle for indicating the deviation of the tube wall thickness from the thickness of the selected standard item.

  1. Thermal insulation properties of walls

    Directory of Open Access Journals (Sweden)

    Zhukov Aleksey Dmitrievich

    2014-05-01

    Full Text Available Heat-protective qualities of building structures are determined by the qualities of the used materials, adequate design solutions and construction and installation work of high quality. This rule refers both to the structures made of materials similar in their structure and nature and mixed, combined by a construction system. The necessity to ecaluate thermal conductivity is important for a product and for a construction. Methods for evaluating the thermal protection of walls are based on the methods of calculation, on full-scale tests in a laboratory or on objects. At the same time there is a reason to believe that even deep and detailed calculation may cause deviation of the values from real data. Using finite difference method can improve accuracy of the results, but it doesn’t solve all problems. The article discusses new approaches to evaluating thermal insulation properties of walls. The authors propose technique of accurate measurement of thermal insulation properties in single blocks and fragments of walls and structures.

  2. Computational Hypersonic Aerodynamics with Emphasis on Earth Reentry Capsules

    Directory of Open Access Journals (Sweden)

    Mihai Leonida NICULESCU

    2016-09-01

    Full Text Available The temperature in the front region of a hypersonic vehicle nose can be extremely high, for example, reaching approximately 11 000 K at a Mach number of 36 (Apollo reentry due to the bow shock wave. In this case, accurate prediction of temperature behind the shock wave is necessary in order to precisely estimate the wall heat flux. A better prediction of wall heat flux leads to smaller safety coefficient for thermal shield of space reentry vehicle; therefore, the size of thermal shield decreases and the payload could increase. However, the accurate prediction of temperature behind the bow shock wave implies the use of a precise chemical model whose partial differential equations are added to Navier-Stokes equations. This second order partial differential system is very difficult to be numerically integrated. For this reason, the present paper deals with the computational hypersonic aerodynamics with chemical reactions with the aim of supporting Earth reentry capsule design.

  3. Google Earth 101

    Science.gov (United States)

    Bailey, J. E.; Sfraga, M.

    2008-12-01

    For the Spring 2008 semester the University of Alaska Fairbanks (UAF) Geography Department developed a new 3-credit course entitled "Exploring the Virtual Earth". The goal of the course was to introduce students to neogeography tools such as Virtual Globes, Google SketchUp and Second Life, and demonstrating how these applications can be used to visualize geoscience datasets. The classes were a combination of lectures, demonstrations and practical exercises, with a particular emphasis on teaching students to author Keyhole Markup Language (KML) files. The assessment of grades included scores based on attendance, KML exercises, a SketchUp modeling project and exams. In addition, all students had to create and present a KML-based project, preferably using their own original geospatial data where available. Some of the more successful students even presented this work to the university community and invited guests at a one-day workshop "KML in the North". By AGU's Fall 2008 meeting, the course will have be taught again, with a syllabus that has been refined based on feedback from students in the Spring. We present the positive and negative lessons learnt, and other insights garnered from a year of teaching this original and unique course.

  4. Uncovering Earth's virome.

    Science.gov (United States)

    Paez-Espino, David; Eloe-Fadrosh, Emiley A; Pavlopoulos, Georgios A; Thomas, Alex D; Huntemann, Marcel; Mikhailova, Natalia; Rubin, Edward; Ivanova, Natalia N; Kyrpides, Nikos C

    2016-08-25

    Viruses are the most abundant biological entities on Earth, but challenges in detecting, isolating, and classifying unknown viruses have prevented exhaustive surveys of the global virome. Here we analysed over 5 Tb of metagenomic sequence data from 3,042 geographically diverse samples to assess the global distribution, phylogenetic diversity, and host specificity of viruses. We discovered over 125,000 partial DNA viral genomes, including the largest phage yet identified, and increased the number of known viral genes by 16-fold. Half of the predicted partial viral genomes were clustered into genetically distinct groups, most of which included genes unrelated to those in known viruses. Using CRISPR spacers and transfer RNA matches to link viral groups to microbial host(s), we doubled the number of microbial phyla known to be infected by viruses, and identified viruses that can infect organisms from different phyla. Analysis of viral distribution across diverse ecosystems revealed strong habitat-type specificity for the vast majority of viruses, but also identified some cosmopolitan groups. Our results highlight an extensive global viral diversity and provide detailed insight into viral habitat distribution and host–virus interactions.

  5. Earth Science Imagery Registration

    Science.gov (United States)

    LeMoigne, Jacqueline; Morisette, Jeffrey; Cole-Rhodes, Arlene; Johnson, Kisha; Netanyahu, Nathan S.; Eastman, Roger; Stone, Harold; Zavorin, Ilya

    2003-01-01

    The study of global environmental changes involves the comparison, fusion, and integration of multiple types of remotely-sensed data at various temporal, radiometric, and spatial resolutions. Results of this integration may be utilized for global change analysis, as well as for the validation of new instruments or for new data analysis. Furthermore, future multiple satellite missions will include many different sensors carried on separate platforms, and the amount of remote sensing data to be combined is increasing tremendously. For all of these applications, the first required step is fast and automatic image registration, and as this need for automating registration techniques is being recognized, it becomes necessary to survey all the registration methods which may be applicable to Earth and space science problems and to evaluate their performances on a large variety of existing remote sensing data as well as on simulated data of soon-to-be-flown instruments. In this paper we present one of the first steps toward such an exhaustive quantitative evaluation. First, the different components of image registration algorithms are reviewed, and different choices for each of these components are described. Then, the results of the evaluation of the corresponding algorithms combining these components are presented o n several datasets. The algorithms are based on gray levels or wavelet features and compute rigid transformations (including scale, rotation, and shifts). Test datasets include synthetic data as well as data acquired over several EOS Land Validation Core Sites with the IKONOS and the Landsat-7 sensors.

  6. The cell wall of Fusarium oxysporum

    NARCIS (Netherlands)

    Schoffelmeer, EAM; Klis, FM; Sietsma, JH; Cornelissen, BJC

    1999-01-01

    Sugar analysis of isolated cell walls from three formae speciales of Fusarium oxysporum showed that they contained not only glucose and (N-acetyl)-glucosamine, but also mannose, galactose, and uronic acids, presumably originating from cell wall glycoproteins. Cell wall glycoproteins accounted for

  7. The cell wall of Fusarium oxysporum

    NARCIS (Netherlands)

    Schoffelmeer, EAM; Klis, FM; Sietsma, JH; Cornelissen, BJC

    1999-01-01

    Sugar analysis of isolated cell walls from three formae speciales of Fusarium oxysporum showed that they contained not only glucose and (N-acetyl)-glucosamine, but also mannose, galactose, and uronic acids, presumably originating from cell wall glycoproteins. Cell wall glycoproteins accounted for 50

  8. To detect anomalies in diaphragm walls

    NARCIS (Netherlands)

    Spruit, R.

    2015-01-01

    Diaphragm walls are potentially ideal retaining walls for deep excavations in densely built-up areas, as they cause no vibrations during their construction and provide structural elements with high strength and stiffness. In the recent past, however, several projects using diaphragm walls as soil an

  9. Static domain wall in braneworld gravity

    Energy Technology Data Exchange (ETDEWEB)

    Abdalla, M.C.B.; Carlesso, P.F. [UNESP, Universidade Estadual Paulista, Instituto de Fisica Teiorica, Rua Dr. Bento Teobaldo Ferraz 271, Bloco II, Barra-Funda, Caixa Postal 70532-2, Sao Paulo, SP (Brazil); Hoff da Silva, J.M. [UNESP, Universidade Estadual Paulista, Departamento de Fisica e Quimica, Guaratingueta, SP (Brazil)

    2014-01-15

    In this paper we consider a static domain wall inside a 3-brane. Different from the standard achievement obtained in General Relativity, the analysis performed here gives a consistency condition for the existence of static domain walls in a braneworld gravitational scenario. Also the behavior of the domain wall's gravitational field in the newtonian limit is shown. (orig.)

  10. Methods & Strategies: Put Your Walls to Work

    Science.gov (United States)

    Jackson, Julie; Durham, Annie

    2016-01-01

    This column provides ideas and techniques to enhance your science teaching. This month's issue discusses planning and using interactive word walls to support science and reading instruction. Many classrooms have word walls displaying vocabulary that students have learned in class. Word walls serve as visual scaffolds to support instruction. To…

  11. Personal Inquiry in the Earth Sciences.

    Science.gov (United States)

    Kaufman, W. Paul

    Designed as a basic workbook using the inquiry process or as a supplementary text in the classroom, this 129 page booklet is divided into five units: Moving in on the Earth From Space, The Earth's Great Bodies of Water, Composition of the Solid Earth, The Earth's Crust is Constantly Changing, and Studying the Earth's History. The exercises are…

  12. Fourteen Times the Earth

    Science.gov (United States)

    2004-08-01

    ESO HARPS Instrument Discovers Smallest Ever Extra-Solar Planet Summary A European team of astronomers [1] has discovered the lightest known planet orbiting a star other than the sun (an "exoplanet"). The new exoplanet orbits the bright star mu Arae located in the southern constellation of the Altar. It is the second planet discovered around this star and completes a full revolution in 9.5 days. With a mass of only 14 times the mass of the Earth, the new planet lies at the threshold of the largest possible rocky planets, making it a possible super Earth-like object. Uranus, the smallest of the giant planets of the Solar System has a similar mass. However Uranus and the new exoplanet differ so much by their distance from the host star that their formation and structure are likely to be very different. This discovery was made possible by the unprecedented accuracy of the HARPS spectrograph on ESO's 3.6-m telescope at La Silla, which allows radial velocities to be measured with a precision better than 1 m/s. It is another clear demonstration of the European leadership in the field of exoplanet research. PR Photo 25a/04: The HARPS Spectrograph and the 3.6m Telescope PR Photo 25b/04: Observed Velocity Variation of mu Arae (3.6m/HARPS, 1.2m Swiss/CORALIE, AAT/UCLES) PR Photo 25c/04: Velocity Variation of mu Arae Observed by HARPS (3.6m/HARPS) PR Photo 25d/04: "Velocity Curve" of mu Arae A unique planet hunting machine ESO PR Photo 25a/04 ESO PR Photo 25a/04 The HARPS Spectrograph and the 3.6m Telescope [Preview - JPEG: 602 x 400 pix - 211k] [Normal - JPEG: 1202 x 800 pix - 645k] Caption: ESO PR Photo 25a/04 represents a montage of the HARPS spectrograph and the 3.6m telescope at La Silla. The upper left shows the dome of the telescope, while the upper right illustrates the telescope itself. The HARPS spectrograph is shown in the lower image during laboratory tests. The vacuum tank is open so that some of the high-precision components inside can be seen. Since the first

  13. AN APPROXIMATION TO LATERAL EARTH PRESSURES FOR K0 CONDITION

    Directory of Open Access Journals (Sweden)

    M. Arslan TEKİNSOY

    1999-01-01

    Full Text Available In this study, the determination of lateral earth pressures of soils or Ko parameter is considered. For this effect, the deformation and the variations in the shear stresses of the soils placed in an oedometer set up were investigated. Based on this data, a general method which can be used in the calculation of lateral pressures of soils has been proposed. The study was carried out on a cohesive soil having two different group symbol and sandy soils with different relative densities. The lateral pressure values measured by thin wall oedometer technique are in very good agreement with those obtained by calculation. In conclusion, lateral earth pressures or the Ko values are depend upon the distribution of the samples, their relative density and consistancy, the magnitude of the pre-consolidation pressure. The proposed method is a simple and economic technique as regards to the approximation and experimentation.

  14. Magnetic field of the Earth

    Science.gov (United States)

    Popov, Aleksey

    2013-04-01

    The magnetic field of the Earth has global meaning for a life on the Earth. The world geophysical science explains: - occurrence of a magnetic field of the Earth it is transformation of kinetic energy of movements of the fused iron in the liquid core of Earth - into the magnetic energy; - the warming up of a kernel of the Earth occurs due to radioactive disintegration of elements, with excretion of thermal energy. The world science does not define the reasons: - drift of a magnetic dipole on 0,2 a year to the West; - drift of lithospheric slabs and continents. The author offers: an alternative variant existing in a world science the theories "Geodynamo" - it is the theory « the Magnetic field of the Earth », created on the basis of physical laws. Education of a magnetic field of the Earth occurs at moving the electric charge located in a liquid kernel, at rotation of the Earth. At calculation of a magnetic field is used law the Bio Savara for a ring electric current: dB = . Magnetic induction in a kernel of the Earth: B = 2,58 Gs. According to the law of electromagnetic induction the Faradey, rotation of a iron kernel of the Earth in magnetic field causes occurrence of an electric field Emf which moves electrons from the center of a kernel towards the mantle. So of arise the radial electric currents. The magnetic field amplifies the iron of mantle and a kernel of the Earth. As a result of action of a radial electric field the electrons will flow from the center of a kernel in a layer of an electric charge. The central part of a kernel represents the field with a positive electric charge, which creates inverse magnetic field Binv and Emfinv When ?mfinv = ?mf ; ?inv = B, there will be an inversion a magnetic field of the Earth. It is a fact: drift of a magnetic dipole of the Earth in the western direction approximately 0,2 longitude, into a year. Radial electric currents a actions with the basic magnetic field of a Earth - it turn a kernel. It coincides with laws

  15. Processing of rare earth concentrates

    Institute of Scientific and Technical Information of China (English)

    Pamela Alex; R. C. Hubli; A.K. Suri

    2005-01-01

    The paper describes process details for extraction of rare earths from an intermediate grade concentrate of Madhya Pradesh region in India and a South African slag. The xenotime concentrate obtained from the former place was an intermediate grade (47%) rare earth phosphate containing both monazite and xenotime. The South African slag was a low-grade waste product typically containing only 4% of rare earths. The rare earth resource concentrates have been treated individually by different methods such as alkali fusion and alkali leaching to convert them into their mixed oxides. Both types of materials have been processed and greater than 98% solubilization of metal values has been achieved in the intermediate grade xenotime and 80% from the South African slag. The residue of xenotime hydroxide has been washed thoroughly to collect the sodium phosphate, as by-product and the slurry pH have been adjusted to separate rare earths from thorium effectively. Other impurities such as uranium and iron have been removed by precipitation of rare earths by oxalic acid. It has been possible to recover >95% yttrium along with other rare earth oxides.

  16. Our Sustainable Earth

    Science.gov (United States)

    Orbach, Raymond L.

    2013-03-01

    Recent evidence demonstrates that the Earth has been warming monotonically since 1980. Transient to equilibrium temperature changes take centuries to develop, as the upper levels of the ocean are slow to respond to atmospheric temperature changes. Atmospheric CO2 concentrations, from ice core and observatory measurements, display consistent increases from historical averages, beginning in about 1880. They can be associated with the use of coal ecause of the spread of the industrial revolution from Great Britain to the European continent and beyond. The climactic consequence of this human-dominated increase in atmospheric CO2 has been suggested to define a geologic epoch, termed the ``Anthropocene.'' This could be a short term, relatively minor change in global climate, or an extreme deviation that lasts for thousands of years. In order to stabilize global temperatures, sharp reductions in CO2 emissions are required: an 80% reduction beginning in 2050. U.S. emissions have declined sharply recently because of market conditions leading to the substitution of natural gas for coal for electricity generation. Whether this is the best use for this resource may be questioned, but it nevertheless reduces CO2 production by 67% from a coal-fired power plant, well on the way to the 80% reduction required for global temperature stabilization. Current methods for CO2 capture and storage are not cost effective, and have been slow (if not absent) to introduce at scale. This paper describes research into some potentially economically feasible approaches: cost-effective capture and storage of CO2 from injection of flue gas into subterranean methane-saturated aquifers at the surface; fuels from sunlight without CO2 production; and large-scale electrical energy storage for intermittent (and even constant) electricity generating sources.

  17. Other Worlds, Other Earths

    Science.gov (United States)

    Sunbury, Susan; Gould, R. R.

    2011-05-01

    The Harvard-Smithsonian Center for Astrophysics is developing a two-to-three week NSF-funded program for middle and high school students using telescope-based investigations of real world cutting edge scientific questions. The goal is to reveal and enhance students' understanding of core concepts in the physical sciences as well as to develop their proficiency in the practice of scientific inquiry. Specifically, students and teachers are joining scientists in the search for habitable worlds by exploring transiting exoplanets. Using robotic telescopes, image processing software and simulations, students take images and then measure the brightness of their target star to create a portrait of a transiting planet including how large it is; the tilt of its orbit; how far it is from its star and what its environment might be like. Once classes collect and analyze their own data, they can begin to compare, combine, and communicate their findings with others in the community. Interactive models help students predict what they might expect to find and interpret what they do find. During the past two years, the Center for Astrophysics has tested the concept in fifty middle-and high-school classrooms, enrichment classes and after school science clubs in 13 states across the United States. To date, astronomy, earth science, and physics students have successfully detected Jupiter-sized planets transiting stars such as TRES-3, HATP-10, and HATP-12. Preliminary results indicate that learning of core concept did occur. Gains in content were most significant in middle school students as this project delivered new information to them while it served primarily as a review of concepts and application of skills for advanced placement classes. A significant change also occurred in students’ self reported knowledge of exoplanets. There was also an increase in students’ awareness of exoplanets and attitudes about science after participating in this project.

  18. Thin Wall Austempered Ductile Iron (TWADI)

    OpenAIRE

    M. Górny; E. Fraś

    2009-01-01

    In this paper the analysis of thin walled castings made of ductile iron is considered. It is shown that thin wall austempered ductile iron can be obtained by means of short-term heat treatment of thin wall castings without addition of alloying elements. Metallographic examinations of 2 mm thin walled castings along with casting with thicker wall thickness (20x28 mm) after different austempring conditions are presented. It has been proved that short-term heat treatment amounted 20 minutes of a...

  19. Applications to particle transport in the Earth`s aurora

    Energy Technology Data Exchange (ETDEWEB)

    Jasperse, J.R.

    1994-12-31

    The visual display of light called the aurora borealis occurs when energetic (1 to 100-keV) electrons, protons, and hydrogen atoms from the Earth`s magnetosphere enter the Earth`s upper atmosphere and collide with the ambient neutral particles. Two kinds of auroras occur in nature: those excited by incident electrons and those excited by incident protons and hydrogen atoms. In this paper, we consider only the latter. The proton-hydrogen aurora may be divided into two altitude regions: high altitudes ({approximately}250 to {approximately}600 km) where charge-changing collisions dominate and energy-loss collisions may be neglected and low altitudes ({approximately}100 to {approximately}250 km) where energy-loss collisions also become important and cause rapid energy degradation. The focus of this review is on the high-altitude region where the one-group approximation is valid.

  20. Heat transport within the Earth

    CERN Document Server

    Herndon, J Marvin

    2011-01-01

    Numerous attempts have been made to interpret Earth's dynamic processes based upon heat transport concepts derived from ordinary experience. But, ordinary experience can be misleading, especially when underlain by false assumptions. Geodynamic considerations traditionally have embraced three modes of heat transport: conduction, convection, and radiation. Recently, I introduced a fourth, "mantle decompression thermal tsunami" that, I submit, is responsible for emplacing heat at the base of the Earth's crust. Here, I review thermal transport within the Earth and speculate that there might be a fifth mode: "heat channeling", involving heat transport from the core to "hot-spots" such as those that power the Hawaiian Islands and Iceland.

  1. China rare earth market review

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Rare earth market remained stagnant recently. The buyers did not show willingness to replenish raw materials affected by weak demand. Most persons in rare earth circle were not confident with the short-term rare earth market. Demand for didymium mischmetal was soft recently. The market of dysprosium related products was quiet and NdFeB magnet producers were inactive in the purchase. Phosphor market was stagnant as well. Buyers were cautious on replenishing the material. There were few inquiries for europium oxide (99.9%) in spot market and transactions were difficult.

  2. The earth's shape and gravity

    CERN Document Server

    Garland, G D; Wilson, J T

    2013-01-01

    The Earth's Shape and Gravity focuses on the progress of the use of geophysical methods in investigating the interior of the earth and its shape. The publication first offers information on gravity, geophysics, geodesy, and geology and gravity measurements. Discussions focus on gravity measurements and reductions, potential and equipotential surfaces, absolute and relative measurements, and gravity networks. The text then elaborates on the shape of the sea-level surface and reduction of gravity observations. The text takes a look at gravity anomalies and structures in the earth's crust; interp

  3. Seismic displacement of gravity retaining walls

    Directory of Open Access Journals (Sweden)

    Kamal Mohamed Hafez Ismail Ibrahim

    2015-08-01

    Full Text Available Seismic displacement of gravity walls had been studied using conventional static methods for controlled displacement design. In this study plain strain numerical analysis is performed using Plaxis dynamic program where prescribed displacement is applied at the bottom boundary of the soil to simulate the applied seismic load. Constrained absorbent side boundaries are introduced to prevent any wave reflection. The studied soil is chosen dense granular sand and modeled as elasto-plastic material according to Mohr–Column criteria while the gravity wall is assumed elastic. By comparing the resulted seismic wall displacements calculated by numerical analysis for six historical ground motions with that calculated by the pseudo-static method, it is found that numerical seismic displacements are either equal to or greater than corresponding pseudo-static values. Permissible seismic wall displacement calculated by AASHTO can be used for empirical estimation of seismic displacement. It is also found that seismic wall displacement is directly proportional with the positive angle of inclination of the back surface of the wall, soil flexibility and with the earthquake maximum ground acceleration. Seismic wall sliding is dominant and rotation is negligible for rigid walls when the ratio between the wall height and the foundation width is less than 1.4, while for greater ratios the wall becomes more flexible and rotation (rocking increases till the ratio reaches 1.8 where overturning is susceptible to take place. Cumulative seismic wall rotation increases with dynamic time and tends to be constant at the end of earthquake.

  4. Hygrothermal analysis of a stabilised rammed earth test building in the UK

    Energy Technology Data Exchange (ETDEWEB)

    Allinson, David [Department of Civil and Building Engineering, Loughborough University, Leicestershire LE11 3TU (United Kingdom); Hall, Matthew [Nottingham Centre for Geomechanics, Division of Materials, Mechanics and Structures, Faculty of Engineering, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom)

    2010-06-15

    This paper describes the analysis of the hygrothermal behaviours of stabilised rammed earth (SRE) walls used in a building in the UK. The analysis was achieved by computer simulation using WUFI Plus v1.2 whole building hygrothermal analysis software. To validate the model, an unoccupied test room in an unheated SRE building was monitored for 10 months. The hygrothermal properties of the SRE material were measured in the laboratory. It is shown that the SRE walls significantly reduced the amplitude of relative humidity fluctuations in the room air and reduced the frequency of high humidity periods at the wall surface. By adapting the model to represent an occupied and conditioned space, it is demonstrated that SRE walls have the potential to reduce the energy demand for humidification/dehumidification plant. (author)

  5. Mechanism of bubble detachment from vibrating walls

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dongjun; Park, Jun Kwon, E-mail: junkeun@postech.ac.kr; Kang, Kwan Hyoung [Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-dong, Pohang 790-784 (Korea, Republic of); Kang, In Seok [Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-dong, Pohang 790-784 (Korea, Republic of)

    2013-11-15

    We discovered a previously unobserved mechanism by which air bubbles detach from vibrating walls in glasses containing water. Chaotic oscillation and subsequent water jets appeared when a wall vibrated at greater than a critical level. Wave forms were developed at water-air interface of the bubble by the wall vibration, and water jets were formed when sufficiently grown wave-curvatures were collapsing. Droplets were pinched off from the tip of jets and fell to the surface of the glass. When the solid-air interface at the bubble-wall attachment point was completely covered with water, the bubble detached from the wall. The water jets were mainly generated by subharmonic waves and were generated most vigorously when the wall vibrated at the volume resonant frequency of the bubble. Bubbles of specific size can be removed by adjusting the frequency of the wall's vibration.

  6. Pulmonary complications of abdominal wall defects.

    Science.gov (United States)

    Panitch, Howard B

    2015-01-01

    The abdominal wall is an integral component of the chest wall. Defects in the ventral abdominal wall alter respiratory mechanics and can impair diaphragm function. Congenital abdominal wall defects also are associated with abnormalities in lung growth and development that lead to pulmonary hypoplasia, pulmonary hypertension, and alterations in thoracic cage formation. Although infants with ventral abdominal wall defects can experience life-threatening pulmonary complications, older children typically experience a more benign respiratory course. Studies of lung and chest wall function in older children and adolescents with congenital abdominal wall defects are few; such investigations could provide strategies for improved respiratory performance, avoidance of respiratory morbidity, and enhanced exercise ability for these children.

  7. POROUS WALL, HOLLOW GLASS MICROSPHERES

    Energy Technology Data Exchange (ETDEWEB)

    Sexton, W.

    2012-06-30

    Hollow Glass Microspheres (HGM) is not a new technology. All one has to do is go to the internet and Google{trademark} HGM. Anyone can buy HGM and they have a wide variety of uses. HGM are usually between 1 to 100 microns in diameter, although their size can range from 100 nanometers to 5 millimeters in diameter. HGM are used as lightweight filler in composite materials such as syntactic foam and lightweight concrete. In 1968 a patent was issued to W. Beck of the 3M{trademark} Company for 'Glass Bubbles Prepared by Reheating Solid Glass Particles'. In 1983 P. Howell was issued a patent for 'Glass Bubbles of Increased Collapse Strength' and in 1988 H. Marshall was issued a patent for 'Glass Microbubbles'. Now Google{trademark}, Porous Wall, Hollow Glass Microspheres (PW-HGMs), the key words here are Porous Wall. Almost every article has its beginning with the research done at the Savannah River National Laboratory (SRNL). The Savannah River Site (SRS) where SRNL is located has a long and successful history of working with hydrogen and its isotopes for national security, energy, waste management and environmental remediation applications. This includes more than 30 years of experience developing, processing, and implementing special ceramics, including glasses for a variety of Department of Energy (DOE) missions. In the case of glasses, SRS and SRNL have been involved in both the science and engineering of vitreous or glass based systems. As a part of this glass experience and expertise, SRNL has developed a number of niches in the glass arena, one of which is the development of porous glass systems for a variety of applications. These porous glass systems include sol gel glasses, which include both xerogels and aerogels, as well as phase separated glass compositions, that can be subsequently treated to produce another unique type of porosity within the glass forms. The porous glasses can increase the surface area compared to &apos

  8. Tube wall thickness measurement apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Lagasse, P.R.

    1987-01-06

    An apparatus is described for measuring the thickness of a tube's wall for the tube's entire length and circumference by determining the deviation of the tube wall thickness from the known thickness of a selected standard item, the apparatus comprising: a. a base; b. a first support member having first and second ends, the first end being connected to the base, the first support member having a sufficiently small circumference that the tube can be slid over the first support member; c. a spherical element, the spherical element being connected to the second end of the first support member. The spherical element has a sufficiently small circumference at its equator that the tube can be slid over the spherical element, the spherical element having at its equator a larger circumference than the first support member; d. a second support member having first and second ends, the first end being connected to the base, the second support member being spaced apart form the first support member; e. a positioning element connected to and moveable relative to the second support member; and f. an indicator connected to the positioning element and being moveable thereby to a location proximate the spherical element. The indicator includes a contact ball for contacting the selected standard item and holding it against the spherical element, the contact ball contacting the tube when the tube is disposed about the spherical element. The indicator includes a dial having a rotatable needle for indicating the deviation of the tube wall thickness from the thickness of the selected standard item, the rotatable needle being operatively connected to and responsive to the position of the contact ball.

  9. Water Walls for Life Support

    Science.gov (United States)

    Flynn, Michael T. (Inventor); Gormly, Sherwin J. (Inventor); Hammoudeh, Mona (Inventor); Richardson, Tra-My Justine (Inventor)

    2017-01-01

    A method and associated system for processing waste gases, liquids and solids, produced by human activity, to separate (i) liquids suitable for processing to produce potable water, (ii) solids and liquids suitable for construction of walls suitable for enclosing a habitat volume and for radiation shielding, and (iii) other fluids and solids that are not suitable for processing. A forward osmosis process and a reverse osmosis process are sequentially combined to reduce fouling and to permit accumulation of different processable substances. The invention may be used for long term life support of human activity.

  10. Explosive Fragmentation of Dividing Walls

    Science.gov (United States)

    1981-07-01

    bloc~ks and the complexity of the molds that would have to be built, it was de- cided to use full-scale masonry blocks. The walls fabricated were 163...Z .y ,. ,- ;. -.. "COMBINED DISTRIBUTION FOR TESI SERIES 3W I o3 10 ’ I • I ’ ii i’i’I l’l ’ I ’-I"* I *1" PiiPl’ ’ 1 ’l i l• iT -7,62 cm Rs

  11. First Wall and Operational Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Lasnier, C; Allen, S; Boedo, J; Groth, M; Brooks, N; McLean, A; LaBombard, B; Sharpe, J; Skinner, C; Whyte, D; Rudakov, D; West, W; Wong, C

    2006-06-19

    In this chapter we review numerous diagnostics capable of measurements at or near the first wall, many of which contribute information useful for safe operation of a tokamak. There are sections discussing infrared cameras, visible and VUV cameras, pressure gauges and RGAs, Langmuir probes, thermocouples, and erosion and deposition measurements by insertable probes and quartz microbalance. Also discussed are dust measurements by electrostatic detectors, laser scattering, visible and IR cameras, and manual collection of samples after machine opening. In each case the diagnostic is discussed with a view toward application to a burning plasma machine such as ITER.

  12. Witten Index and Wall Crossing

    CERN Document Server

    Hori, Kentaro; Yi, Piljin

    2014-01-01

    We compute the Witten index of one-dimensional gauged linear sigma models with at least ${\\mathcal N}=2$ supersymmetry. In the phase where the gauge group is broken to a finite group, the index is expressed as a certain residue integral. It is subject to a change as the Fayet-Iliopoulos parameter is varied through the phase boundaries. The wall crossing formula is expressed as an integral at infinity of the Coulomb branch. The result is applied to many examples, including quiver quantum mechanics that is relevant for BPS states in $d=4$ ${\\mathcal N}=2$ theories.

  13. Earth analysis methods, subsurface feature detection methods, earth analysis devices, and articles of manufacture

    Science.gov (United States)

    West, Phillip B [Idaho Falls, ID; Novascone, Stephen R [Idaho Falls, ID; Wright, Jerry P [Idaho Falls, ID

    2012-05-29

    Earth analysis methods, subsurface feature detection methods, earth analysis devices, and articles of manufacture are described. According to one embodiment, an earth analysis method includes engaging a device with the earth, analyzing the earth in a single substantially lineal direction using the device during the engaging, and providing information regarding a subsurface feature of the earth using the analysis.

  14. Earth analysis methods, subsurface feature detection methods, earth analysis devices, and articles of manufacture

    Science.gov (United States)

    West, Phillip B.; Novascone, Stephen R.; Wright, Jerry P.

    2011-09-27

    Earth analysis methods, subsurface feature detection methods, earth analysis devices, and articles of manufacture are described. According to one embodiment, an earth analysis method includes engaging a device with the earth, analyzing the earth in a single substantially lineal direction using the device during the engaging, and providing information regarding a subsurface feature of the earth using the analysis.

  15. NASA's Earth Science Data Systems

    Science.gov (United States)

    Ramapriyan, H. K.

    2015-01-01

    NASA's Earth Science Data Systems (ESDS) Program has evolved over the last two decades, and currently has several core and community components. Core components provide the basic operational capabilities to process, archive, manage and distribute data from NASA missions. Community components provide a path for peer-reviewed research in Earth Science Informatics to feed into the evolution of the core components. The Earth Observing System Data and Information System (EOSDIS) is a core component consisting of twelve Distributed Active Archive Centers (DAACs) and eight Science Investigator-led Processing Systems spread across the U.S. The presentation covers how the ESDS Program continues to evolve and benefits from as well as contributes to advances in Earth Science Informatics.

  16. Encyclopedia of earth system science

    National Research Council Canada - National Science Library

    Nierenberg, William Aaron

    1992-01-01

    .... The very diversity of the articles attests to the complexity of earth system science as a unique interdisciplinary venture to place humanity in a position to move wisely to protect the global habitat...

  17. Measuring Earth's Magnetic Field Simply.

    Science.gov (United States)

    Stewart, Gay B.

    2000-01-01

    Describes a method for measuring the earth's magnetic field using an empty toilet paper tube, copper wire, clear tape, a battery, a linear variable resistor, a small compass, cardboard, a protractor, and an ammeter. (WRM)

  18. Earth Day Illustrated Haiku Contest

    Science.gov (United States)

    2007-02-01

    As part of their 2007 Chemists Celebrate Earth Day Celebration, the American Chemical Society is sponsoring an illustrated haiku contest for students in grades K 12 around the theme, Recycling—Chemistry Can!

  19. Bringing Education Down to Earth.

    Science.gov (United States)

    Harrington, Robert F.

    1996-01-01

    Argues for a curriculum based on the earth itself that could offer ideas and insights to help students as they mature. Explains that history, geography, literature, science, philosophy, and economics are enriched by the unifying concept of ecology. (DDR)

  20. Spontaneous Behaviors and Wall-Curvature Lead to Apparent Wall Preference in Planarian.

    Directory of Open Access Journals (Sweden)

    Yoshitaro Akiyama

    Full Text Available The planarian Dugesia japonica tends to stay near the walls of its breeding containers and experimental dishes in the laboratory, a phenomenon called "wall preference". This behavior is thought to be important for environmental adaptation, such as hiding by planarians in nature. However, the mechanisms regulating wall-preference behavior are not well understood, since this behavior occurs in the absence of any particular stimulation. Here we show the mechanisms of wall-preference behavior. Surprisingly, planarian wall-preference behavior was also shown even by the head alone and by headless planarians. These results indicate that planarian "wall-preference" behavior only appears to be a "preference" behavior, and is actually an outcome of spontaneous behaviors, rather than of brain function. We found that in the absence of environmental cues planarians moved basically straight ahead until they reached a wall, and that after reaching a wall, they changed their direction of movement to one tangential to the wall, suggesting that this spontaneous behavior may play a critical role in the wall preference. When we tested another spontaneous behavior, the wigwag movement of the planarian head, using computer simulation with various wigwag angles and wigwag intervals, large wigwag angle and short wigwag interval reduced wall-preference behavior. This indicated that wigwag movement may determine the probability of staying near the wall or leaving the wall. Furthermore, in accord with this simulation, when we tested planarian wall-preference behavior using several assay fields with different curvature of the wall, we found that concavity and sharp curvature of walls negatively impacted wall preference by affecting the permissible angle of the wigwag movement. Together, these results indicate that planarian wall preference may be involuntarily caused by the combination of two spontaneous planarian behaviors: moving straight ahead until reaching a wall and

  1. Lunar Return Reentry Thermal Analysis of a Generic Crew Exploration Vehicle Wall Structures

    Science.gov (United States)

    Ko, William L.; Tran, Van T.; Bowles, Jeff

    2007-01-01

    Thermostructural analysis was performed on generic crew exploration vehicle (GCEV) heat shielded wall structures subjected to reentry heating rates based on five potential lunar return reentry trajectories. The GCEV windward outer wall is fabricated with a graphite/epoxy composite honeycomb sandwich panel and the inner wall with an aluminum honeycomb sandwich panel. The outer wall is protected with an ablative Avcoat-5026-39H/CG thermal protection system (TPS). A virtual ablation method (a graphical approximation) developed earlier was further extended, and was used to estimate the ablation periods, ablation heat loads, and the TPS recession layer depths. It was found that up to 83 95 percent of the total reentry heat load was dissipated in the TPS ablation process, leaving a small amount (3-15 percent) of the remaining total reentry heat load to heat the virgin TPS and maintain the TPS surface at the ablation temperature, 1,200 F. The GCEV stagnation point TPS recession layer depths were estimated to be in the range of 0.280-0.910 in, and the allowable minimum stagnation point TPS thicknesses that could maintain the substructural composite sandwich wall at the limit temperature of 300 F were found to be in the range of 0.767-1.538 in. Based on results from the present analyses, the lunar return abort ballistic reentry was found to be quite attractive because it required less TPS weight than the lunar return direct, the lunar return skipping, or the low Earth orbit guided reentry, and only 11.6 percent more TPS weight than the low Earth orbit ballistic reentry that will encounter a considerable weight penalty to obtain the Earth orbit. The analysis also showed that the TPS weight required for the lunar return skipping reentry was much more than the TPS weight necessary for any of the other reentry trajectories considered.

  2. A Report of Contemporary Rammed Earth Construction and Research in North America

    Directory of Open Access Journals (Sweden)

    Arno Schmidt

    2013-01-01

    Full Text Available Contemporary stabilized rammed earth (SRE draws upon traditional rammed earth (RE methods and materials, often incorporating reinforcing steel and rigid insulation, enhancing the structural and energy performance of the walls while satisfying building codes. SRE structures are typically engineered by licensed Structural Engineers using the Concrete Building Code or the Masonry Building Code. The construction process of SRE creates structural walls of relatively high compressive strength appropriate for a broad range of heating and cooling climates. The incorporation of rigid insulation creates a high mass interior wythe that is thermally separated from the exterior, resulting in improved thermal performance. Modular aluminum reinforced formwork allows walls to be built without the use of through ties, common in concrete construction. The North American Rammed Earth Builders Association (NAREBA collaborated with Unisol Engineering Ltd. and the British Columbia Institute of Technology (BCIT on a battery of tests to obtain preliminary data to be used in support of engineering design. The tests included compressive strength comparisons, pull out rebar testing of both horizontally and vertically placed steel, simple beam tests, and the deflection of two composite wall columns with an insulation core and two types of reinforcing steel connections between the RE wythes.

  3. China Rare Earth Holdings Limited

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    China Rare Earth Holdings Limited is a large trans-area corporation and a public company listed in Hong Kong Stock Exchange (Name: China Rare Earth, Code: 0769), with headquarter in Hong Kong. Located on the bank of beautiful Taihu Lake, the subsidiary in Yinxing covers area of 200,000 m2. It has nearly 1,000 employees, 30% of whom are technical staffs. After self-administration and effort, the company passed ISO 9001: 2000 and ISO 14000 Certificaitons.

  4. Near Earth Object Survey Telescope

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The Near Earth Object Survey Telescope (NEOST), located at the Xuyi station of the Purple Mountain Observatory, is a telescope with the most powerful detection capacity, the highest efficiency and the best performance in the fields of near Earth object survey and optical imaging in China. NEOST is an 171.8 Schmidt type telescope with a 1.20 meter primary mirror and a 1.04 meter corrector,

  5. China Rare Earth Market Review

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Rare earth market remained depressed after the New Year affected by the weak demand. Purchaser preferred to consume inventories rather than increase the stockpile. There was a strong wait-and-see atmosphere in the market. Driven by the intense desire to sell out the commodities, traders further decreased their quoted price for rare earth products. Most persons in the market preferred to hold commodities and waited for a rise in the market after the Spring Festival.

  6. China rare earth market review

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    March 21-31,2012 Rare earth market rebounded holistically recently. Price of didymium products rose slightly after being stable for one month. There were also increases in the prices of europium oxide and terbium oxide, which led to a rush by phosphor plants. The market of yttrium-medium and europium-rich minerals remained stagnant though the rare earth market recovered. Price of the mineral was around RMB ¥210,000-250,000/ton.

  7. China Rare Earth Market Review

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    November 20-30.2011 Weak demand resulted in the slack rare market. Consumers did not intend to rep earth enish inventories yet and transactions of rare earth products were stagnant. The market of didymium-related products was in the doldrums. Demand for dysprosium-related products was sluggish. Inquiries for europium oxide (99.9%) were few and dealings of the product were difficult.

  8. Solar influence on Earth's climate

    DEFF Research Database (Denmark)

    Marsh, N.; Svensmark, Henrik

    2003-01-01

    An increasing number of studies indicate that variations in solar activity have had a significant influence on Earth's climate. However, the mechanisms responsible for a solar influence are still not known. One possibility is that atmospheric transparency is influenced by changing cloud properties...... and thereby influence the radiative properties of clouds. If the GCR-Cloud link is confirmed variations in galactic cosmic ray flux, caused by changes in solar activity and the space environment, could influence Earth's radiation budget....

  9. Earth observation for rangeland monitoring

    CSIR Research Space (South Africa)

    Ramoelo, Abel

    2012-10-01

    Full Text Available for the methodology is presented in Figure 1. Figure 1: Conceptual framework for the development of grass nutrient estimation models, using remote sensing at various scales Earth Observation for Rangeland Monitoring DR A RAMOELO, DR M CHO AND DR R MATHIEU CSIR... and canopy N conforms to the underlying geology (Figure 2). ACKNOWLEDGEMENT The authors would like to thank the Department of Science and Technology which contributed financially to this work through the grant ?Earth Observation Application Development...

  10. Next-generation Digital Earth.

    Science.gov (United States)

    Goodchild, Michael F; Guo, Huadong; Annoni, Alessandro; Bian, Ling; de Bie, Kees; Campbell, Frederick; Craglia, Max; Ehlers, Manfred; van Genderen, John; Jackson, Davina; Lewis, Anthony J; Pesaresi, Martino; Remetey-Fülöpp, Gábor; Simpson, Richard; Skidmore, Andrew; Wang, Changlin; Woodgate, Peter

    2012-07-10

    A speech of then-Vice President Al Gore in 1998 created a vision for a Digital Earth, and played a role in stimulating the development of a first generation of virtual globes, typified by Google Earth, that achieved many but not all the elements of this vision. The technical achievements of Google Earth, and the functionality of this first generation of virtual globes, are reviewed against the Gore vision. Meanwhile, developments in technology continue, the era of "big data" has arrived, the general public is more and more engaged with technology through citizen science and crowd-sourcing, and advances have been made in our scientific understanding of the Earth system. However, although Google Earth stimulated progress in communicating the results of science, there continue to be substantial barriers in the public's access to science. All these factors prompt a reexamination of the initial vision of Digital Earth, and a discussion of the major elements that should be part of a next generation.

  11. Helium in Earth's early core

    Science.gov (United States)

    Bouhifd, M. A.; Jephcoat, Andrew P.; Heber, Veronika S.; Kelley, Simon P.

    2013-11-01

    The observed escape of the primordial helium isotope, 3He, from the Earth's interior indicates that primordial helium survived the energetic process of planetary accretion and has been trapped within the Earth to the present day. Two distinct reservoirs in the Earth's interior have been invoked to account for variations in the 3He/4He ratio observed at the surface in ocean basalts: a conventional depleted mantle source and a deep, still enigmatic, source that must have been isolated from processing throughout Earth history. The Earth's iron-based core has not been considered a potential helium source because partitioning of helium into metal liquid has been assumed to be negligible. Here we determine helium partitioning in experiments between molten silicates and iron-rich metal liquids at conditions up to 16GPa and 3,000K. Analyses of the samples by ultraviolet laser ablation mass spectrometry yield metal-silicate helium partition coefficients that range between 4.7×10-3 and 1.7×10-2 and suggest that significant quantities of helium may reside in the core. Based on estimated concentrations of primordial helium, we conclude that the early core could have incorporated enough helium to supply deep-rooted plumes enriched in 3He throughout the age of the Earth.

  12. Greenhouse Earth: A Traveling Exhibition

    Energy Technology Data Exchange (ETDEWEB)

    Booth, W.H.; Caesar, S.

    1992-09-01

    The Franklin Institute Science Museum provided an exhibit entitled the Greenhouse Earth: A Traveling Exhibition. This 3500 square-foot exhibit on global climate change was developed in collaboration with the Association of Science-Technology Centers. The exhibit opened at The Franklin Institute on February 14, 1992, welcoming 291,000 visitors over its three-month stay. During its three-year tour, Greenhouse Earth will travel to ten US cities, reaching two million visitors. Greenhouse Earth aims to deepen public understanding of the scientific issues of global warming and the conservation measures that can be taken to slow its effects. The exhibit features hands-on exhibitry, interactive computer programs and videos, a theater production, a demonstration cart,'' guided tours, and lectures. supplemental educational programs at the Institute included a teachers preview, a symposium on climate change, and a satellite field trip.'' The development of Greenhouse Earth included front-end and formative evaluation procedures. Evaluation includes interviews with visitors, prototypes, and summative surveys for participating museums. During its stay in Philadelphia, Greenhouse Earth was covered by the local and national press, with reviews in print and broadcast media. Greenhouse Earth is the first large-scale museum exhibit to address global climate change.

  13. Anterior chest wall examination reviewed

    Directory of Open Access Journals (Sweden)

    F. Trotta

    2011-09-01

    Full Text Available Anterior chest wall involvement is not infrequently observed within inflammatory arthropaties, particularly if one considers seronegative spondiloarthritides and SAPHO syndrome. Physical examination is unreliable and conventional X-rays analysis is an unsatisfactory tool during diagnostic work-up of this region. Scintigraphic techniques yield informations both on the activity and on the anatomical extent of the disease while computerized tomography visualize the elementary lesions, such as erosions, which characterize the process. Moreover, when available, magnetic resonance imaging couple the ability to finely visualize such lesions with the possibility to show early alterations and to characterize the “activity” of the disease, presenting itself as a powerful tool both for diagnosis and follow-up. This review briefly shows the applications of imaging techniques for the evaluation of the anterior chest wall focusing on what has been done in the SAPHO syndrome which can be considered prototypical for this regional involvement since it is the osteo-articular target mainly affected by the disease.

  14. Beyond Earth: Using Google Earth to Visualize Other Planetary Bodies

    Science.gov (United States)

    Hancher, M.; Beyer, R.; Broxton, M.; Gorelick, N.; Kolb, E.; Weiss-Malik, M.

    2008-12-01

    Virtual globes have revolutionized the way we visualize and understand the Earth, but there are other planetary bodies that can be visualized as well. We will demonstrate the use of Google Earth, KML, and other modern mapping tools for visualizing data that's literally out of this world. Extra-terrestrial virtual globes are poised to revolutionize planetary science, bring an exciting new dimension to science education, and allow users to explore the increasingly breathtaking imagery being sent back to Earth by modern planetary science satellites. We will demonstrate several uses of the latest Google Earth and KML features to visualize planetary data. Global maps of planetary bodies---not just visible imagery maps, but also terrain maps, infra-red maps, minerological maps, and more---can be overlaid on the Google Earth globe using KML, and a number of sources are already making many such maps available. Coverage maps show the polygons that have been imaged by various satellite sensors, with links to the imagery and science data. High-resolution regionated ground overlays allow you to explore the most breathtaking imagery at full resolution, in its geological context, just as we have become accustomed to doing with Earth imagery. Panoramas from landed missions to the Moon and Mars can even be embedded, giving users a first-hand experience of other worlds. We will take you on a guided tour of how these features can best be used to visualize places other than the Earth, and provide pointers to KML from many sources---ourselves and others---that users can build on in constructing their own KML content of other planetary bodies. Using this paradigm for sharing geospatial data will not only enable planetary scientists to more easily build and share data within the scientific community, but will also provide an easy platform for public outreach and education efforts, and will easily allow anyone to layer geospatial information on top of planetary data.

  15. Immersion Refractometry of Isolated Bacterial Cell Walls

    Science.gov (United States)

    Marquis, Robert E.

    1973-01-01

    Immersion-refractometric and light-scattering measurements were adapted to determinations of average refractive indices and physical compactness of isolated bacterial cell walls. The structures were immersed in solutions containing various concentrations of polymer molecules that cannot penetrate into wall pores, and then an estimate was made of the polymer concentration or the refractive index of the polymer solution in which light scattering was reduced to zero. Because each wall preparation was heterogeneous, the refractive index of the medium for zero light scattering had to be estimated by extrapolation. Refractive indices for walls suspended in bovine serum albumin solutions ranged from 1.348 for walls of the rod form of Arthrobacter crystallopoietes to 1.382 for walls of the teichoic acid deficient, 52A5 strain of Staphylococcus aureus. These indices were used to calculate approximate values for solids content per milliliter, and the calculated values agreed closely with those estimated from a knowledge of dextran-impermeable volumes per gram, dry weight, of the walls. When large molecules such as dextrans or serum albumin were used for immersion refractometry, the refractive indices obtained were for entire walls, including both wall polymers and wall water. When smaller molecules that can penetrate wall pores to various extents were used with Micrococcus lysodeikticus walls, the average, apparent refractive index of the structures increased as the molecular size of probing molecules was decreased. It was possible to obtain an estimate of 1.45 to 1.46 for the refractive index of wall polymers, predominantly peptidoglycans in this case, by extrapolating the curve for refractive index versus molecular radius to a value of 0.2 nm, the approximate radius of a water molecule. This relatively low value for polymer refractive index was interpreted as evidence in favor of the amorphous, elastic model of peptidoglycan structure and against the crystalline, rigid

  16. Near wall flow parameters in the blade end-wall corner region

    Science.gov (United States)

    Bhargava, R. K.; Raj, R.

    The effects of secondary end-wall corner flows on near wall flow parameters in turbomachinary are studied. Important near wall flow parameters such as the wall shear stress vector, the mean wall pressure, the wall pressure fluctuations, and the correlation of the wall pressure fluctuation with the velocity fluctuation in three-dimensional turbulent flows are first experimentally investigated. The blade end-wall corner region is simulated by mounting airfoil section of symmetric blades on both sides of the flat plate with semicircular leading edge. Observed changes in the maximum values of the wall shear stress and its location from the corner line could be associated with the streching and attenuation of the horseshoe vortex. The values of wall pressure fluctuation intensity in the blade end-wall corner region are found to be influenced by the changes of the strength of the horseshoe vortex. The correlation of the wall pressure fluctuation with the velocity fluctuation indicated higher values of correlation coefficient in the inner region as compared to the outer region of the shear layer. The values of wall pressure-velocity correlation coefficient in the blade end-wall corner region also decrease in the streamwise direction while increasing in the presence of favorable and adverse pressure gradients.

  17. Determination of Time and Temperature Profiles in a Poured Earth Heat Transfer Process

    Directory of Open Access Journals (Sweden)

    Edgardo Jonathan Suarez-Dominguez

    2015-01-01

    Full Text Available Poured earth is a current alternative in architecture that could provide a solution for building in places with low -income populations because it uses earth located in the surrounding medium. There are several characteristics of the material that must be studied, including thermal conductivity, mainly atregions with extreme climates due to intervening in comfort levels of users. Because of this it is necessary to have mathematical models to predict the heat flux temperature and in turn along poured earth elements for further design. In this paper a non-stationary model for heat flow in a poured earth wall is proposed to describe non stationary flux in it. It was found that the model created engages over 95% for more representative case found at Mexico.

  18. Investigation on the Effect of Drained Strength when Designing Sheet Pile Walls

    DEFF Research Database (Denmark)

    Iversen, Kirsten Malte; Nielsen, Benjaminn Nordahl; Augustesen, Anders Hust

    Long sheet pile walls are constructed in the cities as an integrated part of deep excavations for e.g. parking lots, pumping stations, reservoirs, and cut and cover tunnels. To minimise costs, the strength of the soil needs to be determined in the best possible way. The drained strength of clay...... expressed by c and ϕ is often estimated as c 10% = 10%・cu, and found by estimations based on the soil describtion, respectively. However, due to possible slicken slides and tension cracks, c = 0 is used on the back side of the sheet pile wall. This reduces the strength significantly. A parametric study...... is made on the effective cohesion to investigate the influence of c when designing sheet pile walls. Aalborg Clay is used as a case material. The parametric study is made in both a commercial finite element program and by use of Brinch Hansen’s earth pressure theory. In both studies, the analyses are made...

  19. The effect of construction stage on the development of retaining wall

    Science.gov (United States)

    Ghazaly, Zuhayr Md; Rahim, Mustaqqim Abdul; Hiung, Voo Kien; Isa, Nur Fitriah; Sofri, Liyana Ahmad

    2017-04-01

    With the growing of population and density in metropolitan areas, especially for the narrow space areas, high rise buildings are the best choice to fulfil the demands for the lacking spaces for development. Hence, it seems deep excavation is necessary to construct underground spaces. Control of soil deformation is crucial for deep excavation in congested urban area to minimize its effect on adjacent structures. During excavation of the soil, retaining walls are required to retain the soil behind it. Therefore, an appropriate method or modelling is required to determine the movement of retaining wall due to lateral earth pressure acts behind it. Finite Element Method (FEM) utilizing computer program PLAXIS, was used to estimate the wall and ground deformation at each stage of excavation.

  20. Theoretical prediction of gold vein location in deposits originated by a wall magma intrusion

    Science.gov (United States)

    Martin, Pablo; Maass-Artigas, Fernando; Cortés-Vega, Luis

    2016-05-01

    The isotherm time-evolution resulting from the intrusion of a hot dike in a cold rock is analized considering the general case of nonvertical walls. This is applied to the theoretical prediction of the gold veins location due to isothermal evolution. As in previous treatments earth surface effects are considered and the gold veins are determined by the envelope of the isotherms. The locations of the gold veins in the Callao mines of Venezuela are now well predicted. The new treatment is now more elaborated and complex that in the case of vertical walls, performed in previous papers, but it is more adequated to the real cases as the one in El Callao, where the wall is not vertical.

  1. EarthLabs - Investigating Hurricanes: Earth's Meteorological Monsters

    Science.gov (United States)

    McDaris, J. R.; Dahlman, L.; Barstow, D.

    2007-12-01

    Earth science is one of the most important tools that the global community needs to address the pressing environmental, social, and economic issues of our time. While, at times considered a second-rate science at the high school level, it is currently undergoing a major revolution in the depth of content and pedagogical vitality. As part of this revolution, labs in Earth science courses need to shift their focus from cookbook-like activities with known outcomes to open-ended investigations that challenge students to think, explore and apply their learning. We need to establish a new model for Earth science as a rigorous lab science in policy, perception, and reality. As a concerted response to this need, five states, a coalition of scientists and educators, and an experienced curriculum team are creating a national model for a lab-based high school Earth science course named EarthLabs. This lab course will comply with the National Science Education Standards as well as the states' curriculum frameworks. The content will focus on Earth system science and environmental literacy. The lab experiences will feature a combination of field work, classroom experiments, and computer access to data and visualizations, and demonstrate the rigor and depth of a true lab course. The effort is being funded by NOAA's Environmental Literacy program. One of the prototype units of the course is Investigating Hurricanes. Hurricanes are phenomena which have tremendous impact on humanity and the resources we use. They are also the result of complex interacting Earth systems, making them perfect objects for rigorous investigation of many concepts commonly covered in Earth science courses, such as meteorology, climate, and global wind circulation. Students are able to use the same data sets, analysis tools, and research techniques that scientists employ in their research, yielding truly authentic learning opportunities. This month-long integrated unit uses hurricanes as the story line by

  2. Baltic Earth - Earth System Science for the Baltic Sea Region

    Science.gov (United States)

    Meier, Markus; Rutgersson, Anna; Lehmann, Andreas; Reckermann, Marcus

    2014-05-01

    The Baltic Sea region, defined as its river catchment basin, spans different climate and population zones, from a temperate, highly populated, industrialized south with intensive agriculture to a boreal, rural north. It encompasses most of the Scandinavian Peninsula in the west; most of Finland and parts of Russia, Belarus, and the Baltic states in the east; and Poland and small parts of Germany and Denmark in the south. The region represents an old cultural landscape, and the Baltic Sea itself is among the most studied sea areas of the world. Baltic Earth is the new Earth system research network for the Baltic Sea region. It is the successor to BALTEX, which was terminated in June 2013 after 20 years and two successful phases. Baltic Earth stands for the vision to achieve an improved Earth system understanding of the Baltic Sea region. This means that the research disciplines of BALTEX continue to be relevant, i.e. atmospheric and climate sciences, hydrology, oceanography and biogeochemistry, but a more holistic view of the Earth system encompassing processes in the atmosphere, on land and in the sea as well as in the anthroposphere shall gain in importance in Baltic Earth. Specific grand research challenges have been formulated, representing interdisciplinary research questions to be tackled in the coming years. A major means will be scientific assessments of particular research topics by expert groups, similar to the BACC approach, which shall help to identify knowledge gaps and develop research strategies. Preliminary grand challenges and topics for which Working Groups have been installed include: • Salinity dynamics in the Baltic Sea • Land-Sea biogeochemical feedbacks in the Baltic Sea region • Natural hazards and extreme events in the Baltic Sea region • Understanding sea level dynamics in the Baltic Sea • Understanding regional variability of water and energy exchange • Utility of Regional Climate Models • Assessment of Scenario Simulations

  3. NASA Earth Exchange: A Collaborative Earth Science Platform

    Science.gov (United States)

    Nemani, R. R.; Votava, P.; Michaelis, A.; Melton, F. S.; Hashimoto, H.; Milesi, C.; Wang, W.; Ganguly, S.

    2010-12-01

    The NASA Earth Exchange (NEX) is a collaboration platform for the Earth science community creating new ways for scientific interaction and knowledge sharing. Funded through ARRA, NEX combines state-of-the-art supercomputing, Earth system modeling, workflow management, NASA remote sensing data feeds, and a social networking platform to deliver a complete work environment in which users can explore and analyze large datasets, run modeling codes, collaborate on new or existing projects, and quickly share results among the Earth science communities. The work environment provides NEX members with community supported modeling, analysis and visualization software in conjunction with datasets that are common to the Earth systems science domain. By providing data, software, and large-scale computing power together in a flexible framework, NEX reduces the need for duplicated efforts in downloading data, developing pre-processing software tools, and expanding local compute infrastructures—while accelerating fundamental research, development of new applications, and reducing project costs. The social networking platform provides a forum for NEX members to efficiently share datasets, results, algorithms, codes, and expertise with other members. Since all members' work environments reside on the collaborative platform, sharing may be done without the transfer of large volumes of data or the porting of complex codes—making NEX an ideal platform for building upon and exchanging research, and fostering innovation. Architecture of NEX integrating social networking, super-computing and data center. The prototyping facility allows users to test their models, algorithms prior to deploying them on the super-computers when required.

  4. Cell Wall Assembly in Fucus Zygotes

    Science.gov (United States)

    Quatrano, Ralph S.; Stevens, Patricia T.

    1976-01-01

    Fertilization triggers the assembly of a cell wall around the egg cell of three brown algae, Fucus vesiculosus, F. distichus, and F. inflatus. New polysaccharide polymers are continually being added to the cell wall during the first 24 hours of synchronous embryo development. This wall assembly involves the extracellular deposition of fibrillar material by cytoplasmic vesicles fusing with the plasma membrane. One hour after fertilization a fragmented wall can be isolated free of cytoplasm and contains equal amounts of cellulose and alginic acid with no fucose-containing polymers (fucans) present. Birefringence of the wall caused by oriented cellulose microfibrils is not detected in all zygotes until 4 hours, at which time intact cell walls can be isolated that retain the shape of the zygote. These walls have a relatively low ratio of fucose to xylose and little sulfate when compared to walls from older embryos. When extracts of walls from 4-hour zygotes are subjected to cellulose acetate electrophoresis at pH 7, a single fucan (F1) can be detected. By 12 hours, purified cell walls are composed of fucans containing a relatively high ratio of fucose to xylose and high levels of sulfate, and contain a second fucan (F2) which is electrophoretically distinct from F1. F2 appears to be deposited in only a localized region of the wall, that which elongates to form the rhizoid cell. Throughout wall assembly, the polyuronide block co-polymer alginic acid did not significantly vary its mannuronic (M) to guluronic (G) acid ratio (0.33-0.55) or its block distribution (MG, 54%; GG, 30%; MM, 16%). From 6 to 24 hours of embryo development, the proportion of the major polysaccharide components found in purified walls is stable. Alginic acid is the major polymer and comprises about 60% of the total wall, while cellulose and the fucans each make-up about 20% of the remainder. During the extracellular assembly of this wall, the intracellular levels of the storage glucan laminaran

  5. Earth as an Extrasolar Planet: Earth Model Validation Using EPOXI Earth Observations

    Science.gov (United States)

    Robinson, Tyler D.; Meadows, Victoria S.; Crisp, David; Deming, Drake; A'Hearn, Michael F.; Charbonneau, David; Livengood, Timothy A.; Seager, Sara; Barry, Richard; Hearty, Thomas; hide

    2011-01-01

    The EPOXI Discovery Mission of Opportunity reused the Deep Impact flyby spacecraft to obtain spatially and temporally resolved visible photometric and moderate resolution near-infrared (NIR) spectroscopic observations of Earth. These remote observations provide a rigorous validation of whole disk Earth model simulations used to better under- stand remotely detectable extrasolar planet characteristics. We have used these data to upgrade, correct, and validate the NASA Astrobiology Institute s Virtual Planetary Laboratory three-dimensional line-by-line, multiple-scattering spectral Earth model (Tinetti et al., 2006a,b). This comprehensive model now includes specular reflectance from the ocean and explicitly includes atmospheric effects such as Rayleigh scattering, gas absorption, and temperature structure. We have used this model to generate spatially and temporally resolved synthetic spectra and images of Earth for the dates of EPOXI observation. Model parameters were varied to yield an optimum fit to the data. We found that a minimum spatial resolution of approx.100 pixels on the visible disk, and four categories of water clouds, which were defined using observed cloud positions and optical thicknesses, were needed to yield acceptable fits. The validated model provides a simultaneous fit to the Earth s lightcurve, absolute brightness, and spectral data, with a root-mean-square error of typically less than 3% for the multiwavelength lightcurves, and residuals of approx.10% for the absolute brightness throughout the visible and NIR spectral range. We extend our validation into the mid-infrared by comparing the model to high spectral resolution observations of Earth from the Atmospheric Infrared Sounder, obtaining a fit with residuals of approx.7%, and temperature errors of less than 1K in the atmospheric window. For the purpose of understanding the observable characteristics of the distant Earth at arbitrary viewing geometry and observing cadence, our validated

  6. Advancements in subsurface barrier wall technology

    Energy Technology Data Exchange (ETDEWEB)

    Mutch, R.D. Jr.; Ash, R.E. IV; Caputi, J.R. [Eckenfelder Inc., Mahwah, NJ (United States)

    1995-12-31

    Subsurface barrier walls have been an important component of site remediation efforts for nearly thirty years. However, until the last decade, limited design options were available for barrier wall construction. Most barrier walls were constructed using traditional technologies such as soil-bentonite slurry trench and, in some instances, conventional compacted clay. While other technologies certainly existed, such as vibrating beam and sheet pile walls, they represented a minor share of the remediation market. Today the remediation engineer considering a subsurface barrier wall-based remediation is confronted with a baffling array, of new technologies and permutations of these technologies. Moreover, new technologies are entering the marketplace seemingly on a monthly basis. A partial listing of available barrier wall technologies is presented.

  7. Shape dynamics of growing cell walls

    CERN Document Server

    Banerjee, Shiladitya; Dinner, Aaron R

    2015-01-01

    We introduce a general theoretical framework to study the shape dynamics of actively growing and remodeling surfaces. Using this framework we develop a physical model for growing bacterial cell walls and study the interplay of cell shape with the dynamics of growth and constriction. The model allows us to derive constraints on cell wall mechanical energy based on the observed dynamics of cell shape. We predict that exponential growth in cell size requires a constant amount of cell wall energy to be dissipated per unit volume. We use the model to understand and contrast growth in bacteria with different shapes such as spherical, ellipsoidal, cylindrical and toroidal morphologies. Coupling growth to cell wall constriction, we predict a discontinuous shape transformation, from partial constriction to cell division, as a function of the chemical potential driving cell-wall synthesis. Our model for cell wall energy and shape dynamics relates growth kinetics with cell geometry, and provides a unified framework to d...

  8. Hydrodynamics of ultra-relativistic bubble walls

    Directory of Open Access Journals (Sweden)

    Leonardo Leitao

    2016-04-01

    Full Text Available In cosmological first-order phase transitions, gravitational waves are generated by the collisions of bubble walls and by the bulk motions caused in the fluid. A sizeable signal may result from fast-moving walls. In this work we study the hydrodynamics associated to the fastest propagation modes, namely, ultra-relativistic detonations and runaway solutions. We compute the energy injected by the phase transition into the fluid and the energy which accumulates in the bubble walls. We provide analytic approximations and fits as functions of the net force acting on the wall, which can be readily evaluated for specific models. We also study the back-reaction of hydrodynamics on the wall motion, and we discuss the extrapolation of the friction force away from the ultra-relativistic limit. We use these results to estimate the gravitational wave signal from detonations and runaway walls.

  9. Repair, Evaluation, Maintenance, and Rehabilitation Research Program: Plastic Concrete Cutoff Walls for Earth Dams

    Science.gov (United States)

    1991-03-01

    Water content -- Oven- dry water content tests were performed on wet concrete to develop a correlation between calculated water content and oven dry ...form the batch. Oven dry water content tests were performed in accor- dance with ASTM standard D 2216 for soils. Typical values of oven dry water content...vet room or cure box) strain type of strain measuring system (gross deflection, compressometer, neoprene end caps) water post-test oven dry water content

  10. Off-the-Wall Project Brings Aerial Mapping down to Earth

    Science.gov (United States)

    Davidhazy, Andrew

    2008-01-01

    The technology of aerial photography, photogrametry, has widespread applications in mapping and aerial surveying. A multi-billion-dollar industry, aerial surveying and mapping is "big business" in both civilian and military sectors. While the industry has grown increasingly automated, employment opportunities still exist for people with a basic…

  11. Motional Effect on Wall Shear Stresses

    DEFF Research Database (Denmark)

    Kock, Samuel Alberg; Torben Fründ, Ernst; Yong Kim, Won

    Atherosclerosis is the leading cause of death and severe disability. Wall Shear Stress (WSS), the stress exerted on vessel walls by the flowing blood is a key factor in the development of atherosclerosis. Computational Fluid Dynamics (CFD) is widely used for WSS estimations. Most CFD simulations...... are based on static models to ease computational burden leading to inaccurate estimations. The aim of this work was to estimate the effect of vessel wall deformations (expansion and bending) on WSS levels....

  12. Transport and coherent structures in wall turbulence

    CERN Document Server

    Tardu, Sedat

    2014-01-01

    Wall bounded turbulent flows are of major importance in industrial and environmental fluid mechanics. The structure of the wall turbulence is intrinsically related to the coherent structures that play a fundamental role in the transport process. The comprehension of their regeneration mechanism is indispensable for the development of efficient strategies in terms of drag control and near wall turbulence management. This book provides an up-to-date overview on the progress made in this specific area in recent years.

  13. Electron-wall Interaction in Hall Thrusters

    Energy Technology Data Exchange (ETDEWEB)

    Y. Raitses; D. Staack; M. Keidar; N.J. Fisch

    2005-02-11

    Electron-wall interaction effects in Hall thrusters are studied through measurements of the plasma response to variations of the thruster channel width and the discharge voltage. The discharge voltage threshold is shown to separate two thruster regimes. Below this threshold, the electron energy gain is constant in the acceleration region and therefore, secondary electron emission (SEE) from the channel walls is insufficient to enhance electron energy losses at the channel walls. Above this voltage threshold, the maximum electron temperature saturates.

  14. Experimental investigations on dry stone masonry walls

    OpenAIRE

    2006-01-01

    Brick unreinforced masonry walls have been widely studied both from experimental and numerical point of view, but scarce experimental information is available for dry stone masonry walls that constitute the material more frequently used in the construction of ancient historical constructions. Therefore, the present work aims at increasing the insight about the behavior of typical ancient masonry walls under cyclic loading. To attain such goal, different experimental approaches are consi...

  15. Rectangular Blocks vs Polygonal Walls in Archaeoseismology

    Directory of Open Access Journals (Sweden)

    Klaus-G. Hinzen

    2017-07-01

    Full Text Available Collapsed or deformed walls in ancient structures constitute important evidence in archaeoseismology, where damage is interpreted in terms of earthquake ground motion. A large variety of wall types have been developed during the millennia in different cultural backgrounds. Often walls with polygonal-shaped building blocks are regarded as more earthquake-resistant than a wall consisting of rectangular elements and, as is sometimes speculated, that the irregular wall types were intentionally developed for that purpose. We use simply structured discrete element models of four walls with different block geometries, perfect rectangular, an Inka-type structure and two polygonal designs, to test their dynamic behavior. In addition to an analytic calculation of ground motion, we use measured strong motion signals as boundary conditions for the 3D wall models with varying height to width ratios. At peak ground accelerations between 1.0 and 9.0 m/s2 and major frequencies of 0.5 to 3 Hz, numeric experiments with the horizontally applied analytic ground motions result in clear differences in the resistance of the four wall types with the rectangular block wall being most vulnerable. For more complex measured 3D motions the Inka-type wall proves more stable than the rectangular block wall; however, height to width ratio still has equally strong influence on the stability. Internal deformation of non-collapsed walls shows some correlation with the parameters of the driving motion. For simple impulsive ground motions, a peak ground displacement threshold exists between toppling and remaining upright for all four models but peak acceleration cannot be reliably back calculated.

  16. Suppression of Hydroxycinnamate Network Formation in Cell Walls of Rice Shoots Grown under Microgravity Conditions in Space.

    Science.gov (United States)

    Wakabayashi, Kazuyuki; Soga, Kouichi; Hoson, Takayuki; Kotake, Toshihisa; Yamazaki, Takashi; Higashibata, Akira; Ishioka, Noriaki; Shimazu, Toru; Fukui, Keiji; Osada, Ikuko; Kasahara, Haruo; Kamada, Motoshi

    2015-01-01

    Network structures created by hydroxycinnamate cross-links within the cell wall architecture of gramineous plants make the cell wall resistant to the gravitational force of the earth. In this study, the effects of microgravity on the formation of cell wall-bound hydroxycinnamates were examined using etiolated rice shoots simultaneously grown under artificial 1 g and microgravity conditions in the Cell Biology Experiment Facility on the International Space Station. Measurement of the mechanical properties of cell walls showed that shoot cell walls became stiff during the growth period and that microgravity suppressed this stiffening. Amounts of cell wall polysaccharides, cell wall-bound phenolic acids, and lignin in rice shoots increased as the shoot grew. Microgravity did not influence changes in the amounts of cell wall polysaccharides or phenolic acid monomers such as ferulic acid (FA) and p-coumaric acid, but it suppressed increases in diferulic acid (DFA) isomers and lignin. Activities of the enzymes phenylalanine ammonia-lyase (PAL) and cell wall-bound peroxidase (CW-PRX) in shoots also increased as the shoot grew. PAL activity in microgravity-grown shoots was almost comparable to that in artificial 1 g-grown shoots, while CW-PRX activity increased less in microgravity-grown shoots than in artificial 1 g-grown shoots. Furthermore, the increases in expression levels of some class III peroxidase genes were reduced under microgravity conditions. These results suggest that a microgravity environment modifies the expression levels of certain class III peroxidase genes in rice shoots, that the resultant reduction of CW-PRX activity may be involved in suppressing DFA formation and lignin polymerization, and that this suppression may cause a decrease in cross-linkages within the cell wall architecture. The reduction in intra-network structures may contribute to keeping the cell wall loose under microgravity conditions.

  17. Suppression of Hydroxycinnamate Network Formation in Cell Walls of Rice Shoots Grown under Microgravity Conditions in Space.

    Directory of Open Access Journals (Sweden)

    Kazuyuki Wakabayashi

    Full Text Available Network structures created by hydroxycinnamate cross-links within the cell wall architecture of gramineous plants make the cell wall resistant to the gravitational force of the earth. In this study, the effects of microgravity on the formation of cell wall-bound hydroxycinnamates were examined using etiolated rice shoots simultaneously grown under artificial 1 g and microgravity conditions in the Cell Biology Experiment Facility on the International Space Station. Measurement of the mechanical properties of cell walls showed that shoot cell walls became stiff during the growth period and that microgravity suppressed this stiffening. Amounts of cell wall polysaccharides, cell wall-bound phenolic acids, and lignin in rice shoots increased as the shoot grew. Microgravity did not influence changes in the amounts of cell wall polysaccharides or phenolic acid monomers such as ferulic acid (FA and p-coumaric acid, but it suppressed increases in diferulic acid (DFA isomers and lignin. Activities of the enzymes phenylalanine ammonia-lyase (PAL and cell wall-bound peroxidase (CW-PRX in shoots also increased as the shoot grew. PAL activity in microgravity-grown shoots was almost comparable to that in artificial 1 g-grown shoots, while CW-PRX activity increased less in microgravity-grown shoots than in artificial 1 g-grown shoots. Furthermore, the increases in expression levels of some class III peroxidase genes were reduced under microgravity conditions. These results suggest that a microgravity environment modifies the expression levels of certain class III peroxidase genes in rice shoots, that the resultant reduction of CW-PRX activity may be involved in suppressing DFA formation and lignin polymerization, and that this suppression may cause a decrease in cross-linkages within the cell wall architecture. The reduction in intra-network structures may contribute to keeping the cell wall loose under microgravity conditions.

  18. Recovery after abdominal wall reconstruction

    DEFF Research Database (Denmark)

    Jensen, Kristian Kiim

    2017-01-01

    was lacking. Study II was a case-control study of the effects of an enhanced recovery after surgery pathway for patients undergoing abdominal wall reconstruction for a giant hernia. Sixteen consecutive patients were included prospectively after the implementation of a new enhanced recovery after surgery...... pathway at the Digestive Disease Center, Bispebjerg Hospital, and compared to a control group of 16 patients included retrospectively in the period immediately prior to the implementation of the pathway. The enhanced recovery after surgery pathway included preoperative high-dose steroid, daily assessment...... of revised discharge criteria and an aggressive approach to restore bowel function (chewing gum and enema on postoperative day two). Patients who followed the enhanced recovery after surgery pathway reported low scores of pain, nausea and fatigue, and were discharged significantly faster than patients...

  19. Four ways across the wall

    CERN Document Server

    Pioline, Boris

    2011-01-01

    An important question in the study of N=2 supersymmetric string or field theories is to compute the jump of the BPS spectrum across walls of marginal stability in the space of parameters or vacua. I survey four apparently different answers for this problem, two of which are based on the mathematics of generalized Donaldson-Thomas invariants (the Kontsevich-Soibelman and the Joyce-Song formulae), while the other two are based on the physics of multi-centered black hole solutions (the Coulomb branch and the Higgs branch formulae, discovered in joint work with J. Manschot and A. Sen). Explicit computations indicate that these formulae are equivalent, though a combinatorial proof is currently lacking.

  20. Creating universes with thick walls

    Science.gov (United States)

    Ulvestad, Andrew; Albrecht, Andreas

    2012-05-01

    We study the dynamics of a spherically symmetric false vacuum bubble embedded in a true vacuum region separated by a “thick wall”, which is generated by a scalar field in a quartic potential. We study the “Farhi-Guth-Guven” (FGG) quantum tunneling process by constructing numerical solutions relevant to this process. The Arnowitt-Deser-Misner mass of the spacetime is calculated, and we show that there is a lower bound that is a significant fraction of the scalar field mass. We argue that the zero mass solutions used to by some to argue against the physicality of the FGG process are artifacts of the thin wall approximation used in earlier work. We argue that the zero mass solutions should not be used to question the viability of the FGG process.

  1. Virtual gap dielectric wall accelerator

    Science.gov (United States)

    Caporaso, George James; Chen, Yu-Jiuan; Nelson, Scott; Sullivan, Jim; Hawkins, Steven A

    2013-11-05

    A virtual, moving accelerating gap is formed along an insulating tube in a dielectric wall accelerator (DWA) by locally controlling the conductivity of the tube. Localized voltage concentration is thus achieved by sequential activation of a variable resistive tube or stalk down the axis of an inductive voltage adder, producing a "virtual" traveling wave along the tube. The tube conductivity can be controlled at a desired location, which can be moved at a desired rate, by light illumination, or by photoconductive switches, or by other means. As a result, an impressed voltage along the tube appears predominantly over a local region, the virtual gap. By making the length of the tube large in comparison to the virtual gap length, the effective gain of the accelerator can be made very large.

  2. ON WALL SHEAR STRESS OF ARTERY

    Institute of Scientific and Technical Information of China (English)

    Liu Zhao-rong; Liu Bao-yu; Qin Kai-rong

    2003-01-01

    In this paper, a method was proposed that the wall shear stress of artery could be determined by measuring the centerline axial velocity and radial motion of arterial wall simultaneously.The method is simple in application and can get higher precision when it is used to determine the shear stress of arterial wall in vivo.As an example, the shear stress distribution in periodic oscillatory flow of human carotid was calculated and discussed.The computed results show that the shear stress distribution at any given instant is almost uniform and will be zero at the centerline and tends to maximum at the vessel wall.

  3. Great attractor really a great wall

    Energy Technology Data Exchange (ETDEWEB)

    Stebbins, A.; Turner, M.S.

    1988-11-01

    Some of the cosmological consequences are discussed of a late time phase transition which produces light domain walls. The observed peculiar velocity field of the Universe and the observed isotropy of the microwave background radiation severely constrain the wall surface density in such a scenario. The most interesting consequence of such a phase transition is the possibility that the local, coherent streaming motion reported by the Seven Samurai could be explained by the repulsive effect of a relic domain wall with the Hubble volume (the Great Wall).

  4. Scaling analysis on filtered near wall turbulence

    Science.gov (United States)

    Mohan, Prakash; Moser, Robert

    2016-11-01

    Large Eddy Simulations (LES) directly represent larger scale turbulent motions and model the effects of small scale motions. However in the near wall region the large dynamically important eddies scale in viscous wall units, which makes resolving them in a high Reynolds number LES very expensive. This motivates the use of wall-modeled LES, in which these near-wall eddies are modeled. To aid in the development of new wall models, we pursue an asymptotic analysis of the filtered Navier-Stokes equations, in the limit in which the horizontal filter scale is large compared to the thickness of the wall layer. It will be shown that in this limit the filtered velocities u and subgrid stresses τ in the near-wall layer are determined to zeroth order by filtered velocities at the boundary of the wall layer. Further the asymptotics suggest that there is a scaled universal velocity profile f and subgrid stress profile g in the near-wall region. The validity of this result will be tested and the profiles f and g will be evaluated through analysis of DNS data from channel flow at Reτ = 5200 .

  5. Determination of arterial wall shear stress

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The arteries can remodel their structure and function to adapt themselves to the mechanical environment. In various factors that lead to vascular remodeling, the shear stress on the arterial wall induced by the blood flow is of great importance. However, there are many technique difficulties in measuring the wall shear stress directly at present. In this paper, through analyzing the pulsatile blood flow in arteries, a method has been proposed that can determine the wall shear stress quantitatively by measuring the velocity on the arterial axis, and that provides a necessary means to discuss the influence of arterial wall shear stress on vascular remodeling.

  6. Statistical analysis of silo wall pressures

    DEFF Research Database (Denmark)

    Ditlevsen, Ove Dalager; Berntsen, Kasper Nikolaj

    1998-01-01

    Previously published silo wall pressure measurements during plug flow of barley in alarge concrete silo are re-analysed under the hypothesis that the wall pressures are gamma-distributed.The fits of the gamma distribution type to the local pressure data from each measuring cell are satisfactory.......However, the estimated parameters of the gamma distributions turn out to be significantly inhomogeneous overthe silo wall surface. This inhomogeneity is attributed to the geometrical imperfections of the silo wall.Motivated by the engineering importance of the problem a mathematical model for constructing astochastic...

  7. Relevant surgical anatomy of the chest wall.

    Science.gov (United States)

    Naidu, Babu V; Rajesh, Pala B

    2010-11-01

    The chest wall, like other regional anatomy, is a remarkable fusion of form and function. Principal functions are the protection of internal viscera and an expandable cylinder facilitating variable gas flow into the lungs. Knowledge of the anatomy of the whole cylinder (ribs, sternum, vertebra, diaphragm, intercostal spaces, and extrathoracic muscles) is therefore not only important in the local environment of a specific chest wall resection but also in its relation to overall function. An understanding of chest wall kinematics might help define the loss of function after resection and the effects of various chest wall substitutes. Therefore, this article is not an exhaustive anatomic description but a focused summary and discussion.

  8. Fillability of Thin-Wall Steel Castings

    Energy Technology Data Exchange (ETDEWEB)

    Robert C. Voigt; Joseph Bertoletti; Andrew Kaley; Sandi Ricotta; Travis Sunday

    2002-07-30

    The use of steel components is being challenged by lighter nonferrous or cast iron components. The development of techniques for enhancing and ensuring the filability of thin-wall mold cavities is most critical for thinner wall cast steel production. The purpose of this research was to develop thin-wall casting techniques that can be used to reliably produce thin-wall castings from traditional gravity poured sand casting processes. The focus of the research was to enhance the filling behavior to prevent misrunds. Experiments were conducted to investigate the influence of various foundry variables on the filling of thin section steel castings. These variables include casting design, heat transfer, gating design, and metal fluidity. Wall thickness and pouring temperature have the greatest effect on casting fill. As wall thickness increases the volume to surface area of the casting increases, which increases the solidification time, allowing the metal to flow further in thicker sect ions. Pouring time is another significant variable affecting casting fill. Increases or decreases of 20% in the pouring time were found to have a significant effect on the filling of thin-wall production castings. Gating variables, including venting, pouring head height, and mold tilting also significantly affected thin-wall casting fill. Filters offer less turbulent, steadier flow, which is appropriate for thicker castings, but they do not enhance thin-wall casting fill.

  9. Skyrmions from Instantons inside Domain Walls

    CERN Document Server

    Eto, M; Ohashi, K; Tong, D; Eto, Minoru; Nitta, Muneto; Ohashi, Keisuke; Tong, David

    2005-01-01

    Some years ago, Atiyah and Manton described a method to construct approximate Skyrmion solutions from Yang-Mills instantons. Here we present a dynamical realization of this construction using domain walls in a five-dimensional gauge theory. The non-abelian gauge symmetry is broken in each vacuum but restored in the core of the domain wall, allowing instantons to nestle inside the wall. We show that the worldvolume dynamics of the wall is given by the Skyrme model, including the four-derivative term, and the instantons appear as Skyrmions.

  10. Microanalysis of Plant Cell Wall Polysaccharides

    Institute of Scientific and Technical Information of China (English)

    Nicolai Obel; Veronika Erben; Tatjana Schwarz; Stefan Kühne; Andrea Fodor; Markus Pauly

    2009-01-01

    Oligosaccharide Mass Profiling (OLIMP) allows a fast and sensitive assessment of cell wall polymer structure when coupled with Matrix Assisted Laser Desorption Ionisation Time Of Flight Mass Spectrometry (MALDI-TOF MS). The short time required for sample preparation and analysis makes possible the study of a wide range of plant organs, revealing a high degree of heterogeneity in the substitution pattern of wall polymers such as the cross-linking glycan xyloglucan and the pectic polysaccharide homogalacturonan. The high sensitivity of MALDI-TOF allows the use of small amounts of samples, thus making it possible to investigate the wall structure of single cell types when material is collected by such methods as laser micro-dissection. As an example, the analysis of the xyloglucan structure in the leaf cell types outer epidermis layer, entire epidermis cell layer, palisade mesophyll cells, and vascular bundles were investigated. OLIMP is amenable to in situ wall analysis, where wall polymers are analyzed on unprepared plant tissue itself without first iso-lating cell walls. In addition, OLIMP enables analysis of wall polymers in Golgi-enriched fractions, the location of nascent matrix polysaccharide biosynthesis, enabling separation of the processes of wall biosynthesis versus post-deposition apo-plastic metabolism. These new tools will make possible a semi-quantitative analysis of the cell wall at an unprecedented level.

  11. Molecular regulation of plant cell wall extensibility

    Science.gov (United States)

    Cosgrove, D. J.

    1998-01-01

    Gravity responses in plants often involve spatial and temporal changes in cell growth, which is regulated primarily by controlling the ability of the cell wall to extend. The wall is thought to be a cellulose-hemicellulose network embedded in a hydrated matrix of complex polysaccharides and a small amount of structural protein. The wall extends by a form of polymer creep, which is mediated by expansins, a novel group of wall-loosening proteins. Expansins were discovered during a molecular dissection of the "acid growth" behavior of cell walls. Expansin alters the rheology of plant walls in profound ways, yet its molecular mechanism of action is still uncertain. It lacks detectable hydrolytic activity against the major components of the wall, but it is able to disrupt noncovalent adhesion between wall polysaccharides. The discovery of a second family of expansins (beta-expansins) sheds light on the biological role of a major group of pollen allergens and implies that expansins have evolved for diverse developmental functions. Finally, the contribution of other processes to wall extensibility is briefly summarized.

  12. A hypothesis of earth quake

    CERN Document Server

    Tsai, Yeong-Shyeong

    2008-01-01

    Without a model, it is impossible for a geophysicist to study the possibility of forecasting earth quakes. In order to make a simple model, we make a hypothesis of earth quakes. The hypothesis is: (i) There are two kinds of earth quakes, one is the triggered breaking (earth quake), the other is spontaneous breaking (earth quake). (ii) Most major quakes in continental plates Eurasian Plate, North America Plate, South America Plate, Africa Plate and Australia Plate are triggered breaking. (iii) These triggered quakes are triggered by the movements of high pressure centers and low pressure centers of the atmosphere on continental plates. (iv) How can the movements of the high pressure centers trigger a quake? It depends on the extent of the high pressure center and the speed of the movement. Here, we stress high pressure center instead of low pressure center because it is dominated by high pressure center mostly. Of course, the boundary of the plates must have stored enough energy to have quakes, that is, near t...

  13. Electromagnetic approaches to wall characterization, wall mitigation, and antenna design for through-the-wall radar systems

    Science.gov (United States)

    Thajudeen, Christopher

    Through-the-wall imaging (TWI) is a topic of current interest due to its wide range of public safety, law enforcement, and defense applications. Among the various available technologies such as, acoustic, thermal, and optical imaging, which can be employed to sense and image targets of interest, electromagnetic (EM) imaging, in the microwave frequency bands, is the most widely utilized technology and has been at the forefront of research in recent years. The primary objectives for any Through-the-Wall Radar Imaging (TWRI) system are to obtain a layout of the building and/or inner rooms, detect if there are targets of interest including humans or weapons, determine if there are countermeasures being employed to further obscure the contents of a building or room of interest, and finally to classify the detected targets. Unlike conventional radar scenarios, the presence of walls, made of common construction materials such as brick, drywall, plywood, cinder block, and solid concrete, adversely affects the ability of any conventional imaging technique to properly image targets enclosed within building structures as the propagation through the wall can induce shadowing effects on targets of interest which may result in image degradation, errors in target localization, and even complete target masking. For many applications of TWR systems, the wall ringing signals are strong enough to mask the returns from targets not located a sufficient distance behind the wall, beyond the distance of the wall ringing, and thus without proper wall mitigation, target detection becomes extremely difficult. The results presented in this thesis focus on the development of wall parameter estimation, and intra-wall and wall-type characterization techniques for use in both the time and frequency domains as well as analysis of these techniques under various real world scenarios such as reduced system bandwidth scenarios, various wall backing scenarios, the case of inhomogeneous walls, presence

  14. Determination of strength behaviour of slope supported by vegetated crib walls using centrifuge model testing

    Science.gov (United States)

    Sudan Acharya, Madhu

    2010-05-01

    The crib retaining structures made of wooden/bamboo logs with live plants inside are called vegetative crib walls which are now becoming popular due to their advantages over conventional civil engineering walls. Conventionally, wooden crib walls were dimensioned based on past experiences. At present, there are several guidelines and design standards for machine finished wooden crib walls, but only few guidelines for the design and construction of vegetative log crib walls are available which are generally not sufficient for an economic engineering design of such walls. Analytical methods are generally used to determine the strength of vegetated crib retaining walls. The crib construction is analysed statically by satisfying the condition of static equilibrium with acceptable level of safety. The crib wall system is checked for internal and external stability using conventional monolithic and silo theories. Due to limitations of available theories, the exact calculation of the strength of vegetated wooden/bamboo crib wall cannot be made in static calculation. Therefore, experimental measurements are generally done to verify the static analysis. In this work, a model crib construction (1:20) made of bamboo elements is tested in the centrifuge machine to determine the strength behaviour of the slope supported by vegetated crib retaining wall. A geotechnical centrifuge is used to conduct model tests to study geotechnical problems such as the strength, stiffness and bearing capacity of different structures, settlement of embankments, stability of slopes, earth retaining structures etc. Centrifuge model testing is particularly well suited to modelling geotechnical events because the increase in gravitational force creates stresses in the model that are equivalent to the much larger prototype and hence ensures that the mechanisms of ground movements observed in the tests are realistic. Centrifuge model testing provides data to improve our understanding of basic mechanisms

  15. Development Trend of Rare Earth Standardion Work

    Institute of Scientific and Technical Information of China (English)

    Ma Jie; Lin Jirong; Zhao Fei; Zhang Xiuyan

    2004-01-01

    Rare earth standardization was developed along with rare earth industry.In recent decades, great advances have been made in China rare earth industry.This paper describes the status of rare earth standardization, problems existed and ways to perfect.Now the number of Chinese Rare Earth Standards has increased to 232 with expanding of the categories and covering scope of rare earth products.But the present standard system cannot be completely suited with rare earth production and trade, and not keep pace with the advance of technology.Standards are important rules in world trade and must be acted on.

  16. ESA's Earth Observation in Support of Geoscience

    Science.gov (United States)

    Liebig, Volker

    2016-04-01

    The intervention will present ESA's Earth Observation Programme and its contribution to Geoscience. ESA's Earth observation missions are mainly grouped into three categories: The Sentinel satellites in the context of the European Copernicus Programme, the scientific Earth Explorers and the meteorological missions. Developments, applications and scientific results for the different mission types will be addressed, along with overall trends and strategies. A special focus will be put on the Earth Explorers, who form the science and research element of ESA's Living Planet Programme and focus on the atmosphere, biosphere, hydrosphere, cryosphere and Earth's interior. In addition the operational Sentinel satellites have a huge potential for Geoscience. Earth Explorers' emphasis is also on learning more about the interactions between these components and the impact that human activity is having on natural Earth processes. The process of Earth Explorer mission selection has given the Earth science community an efficient tool for advancing the understanding of Earth as a system.

  17. Interconnections between cell wall polymers, wall mechanics, and cortical microtubules: Teasing out causes and consequences.

    Science.gov (United States)

    Xiao, Chaowen; Anderson, Charles T

    2016-09-01

    In plants, cell wall components including cellulose, hemicelluloses, and pectins interact with each other to form complex extracellular network structures that control cell growth and maintain cell shape. However, it is still not clear exactly how different wall polymers interact, how the conformations and interactions of cell wall polymers relate to wall mechanics, and how these factors impinge on intracellular structures such as the cortical microtubule cytoskeleton. Here, based on studies of Arabidopsis thaliana xxt1 xxt2 mutants, which lack detectable xyloglucan in their walls and display aberrant wall mechanics, altered cellulose patterning and biosynthesis, and reduced cortical microtubule stability, we discuss the potential relationships between cell wall biosynthesis, wall mechanics, and cytoskeletal dynamics in an effort to better understand their roles in controlling plant growth and morphogenesis.

  18. Magnetic domain wall induced ferroelectricity in double perovskites

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Hai Yang; Zhao, Hong Jian, E-mail: dielectric-hjzhao@126.com, E-mail: xmchen59@zju.edu.cn; Chen, Xiang Ming, E-mail: dielectric-hjzhao@126.com, E-mail: xmchen59@zju.edu.cn [Laboratory of Dielectric Materials, Department of Materials Science and Engineering, Zhejiang University, 38 Zheda Road, Hangzhou 310027 (China); Zhang, Wen Qing [Department of Physics, Shanghai University, 99 Shangda Road, Shanghai 200444 (China)

    2015-04-13

    Recently, a magnetically induced ferroelectricity occurring at magnetic domain wall of double perovskite Lu{sub 2}CoMnO{sub 6} has been reported experimentally. However, there exists a conflict whether the electric polarization is along b or c direction. Here, by first-principles calculations, we show that the magnetic domain wall (with ↑↑↓↓ spin configuration) can lead to the ferroelectric displacements of R{sup 3+}, Ni{sup 2+}, Mn{sup 4+}, and O{sup 2−} ions in double perovskites R{sub 2}NiMnO{sub 6} (R = rare earth ion) via exchange striction. The resulted electric polarization is along b direction with the P2{sub 1} symmetry. We further reveal the origin of the ferroelectric displacements as that: (1) on a structural point of view, such displacements make the two out-of-plane Ni-O-Mn bond angles as well as Ni-Mn distance unequal, and (2) on an energy point of view, such displacements weaken the out-of-plane Ni-Mn super-exchange interaction obviously. Finally, our calculations show that such a kind of ferroelectric order is general in ferromagnetic double perovskites.

  19. Cold Climate Foundation Retrofit Energy Savings: The Simulated Energy and Experimental Hygrothermal Performance of Cold Climate Foundation Wall Insulation Retrofit Measures -- Phase I, Energy Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, L. F.; Steigauf, B.

    2013-04-01

    A split simulation whole building energy/3-dimensional earth contact model (termed the BUFETS/EnergyPlus Model or BEM) capable of modeling the full range of foundation systems found in the target retrofit housing stock has been extensively tested. These foundation systems that include abovegrade foundation walls, diabatic floors or slabs as well as lookout or walkout walls, currently cannot be modeled within BEopt.

  20. Cold Climate Foundation Retrofit Energy Savings. The Simulated Energy and Experimental Hygrothermal Performance of Cold Climate Foundation Wall Insulation Retrofit Measures -- Phase I, Energy Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, Louise F. [NorthernSTAR Building America Partnership, Minneapolis, MN (United States); Steigauf, Brianna [NorthernSTAR Building America Partnership, Minneapolis, MN (United States)

    2013-04-01

    A split simulation whole building energy / 3-dimensional earth contact model (termed the BUFETS/EnergyPlus Model or BEM) capable of modeling the full range of foundation systems found in the target retrofit housing stock has been extensively tested. These foundation systems that include abovegrade foundation walls, diabatic floors or slabs as well as lookout or walkout walls, currently cannot be modeled within BEopt.

  1. Revolutions that made the earth

    CERN Document Server

    Lenton, Tim

    2013-01-01

    The Earth that sustains us today was born out of a few remarkable, near-catastrophic revolutions, started by biological innovations and marked by global environmental consequences. The revolutions have certain features in common, such as an increase in the complexity, energy utilization, and information processing capabilities of life. This book describes these revolutions, showing the fundamental interdependence of the evolution of life and its non-living environment. We would not exist unless these upheavals had led eventually to 'successful' outcomes - meaning that after each one, at length, a new stable world emerged. The current planet-reshaping activities of our species may be the start of another great Earth system revolution, but there is no guarantee that this one will be successful. This book explains what a successful transition through it might look like, if we are wise enough to steer such a course. This book places humanity in context as part of the Earth system, using a new scientific synthe...

  2. Earth's Heat Source - The Sun

    CERN Document Server

    Manuel, Oliver K

    2009-01-01

    The Sun encompasses planet Earth, supplies the heat that warms it, and even shakes it. The United Nation Intergovernmental Panel on Climate Change (IPCC) assumed that solar influence on our climate is limited to changes in solar irradiance and adopted the consensus opinion of a Hydrogen-filled Sun, the Standard Solar Model (SSM). They did not consider the alternative solar model and instead adopted another consensus opinion: Anthropogenic greenhouse gases play a dominant role in climate change. The SSM fails to explain the solar wind, solar cycles, and the empirical link of solar surface activity with Earth changing climate. The alternative solar model, that was molded from an embarrassingly large number of unexpected observations revealed by space-age measurements since 1959, explains not only these puzzles but also how closely linked interactions between the Sun and its planets and other celestial bodies induce turbulent cycles of secondary solar characteristics that significantly affect Earth climate.

  3. Rare Earth Separation in China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    During the last decade, China rare earth (RE) industry has made significant progress and become one of the most important producers in the world. In this paper, the recent developments in both fundamental research and industrial application are briefly reviewed: (1) the development and application of Theory of Countercurrent Extraction, (2) the novel solvent extraction process and its application in industry for separating heavy rare earth elements (Tm, Yb, Lu), yttrium (Y), and scandium (Sc), (3) the on-line analysis and automatic control of countercurrent extraction, (4) the eco-friendly process for RE/Th separation of bastnasite in Sichuan Province and electrochemical process for Eu/RE separation, and (5) the optimized flowcharts for typical rare earth minerals in China.

  4. Models of the earth's core

    Science.gov (United States)

    Stevenson, D. J.

    1981-01-01

    Combined inferences from seismology, high-pressure experiment and theory, geomagnetism, fluid dynamics, and current views of terrestrial planetary evolution lead to models of the earth's core with five basic properties. These are that core formation was contemporaneous with earth accretion; the core is not in chemical equilibrium with the mantle; the outer core is a fluid iron alloy containing significant quantities of lighter elements and is probably almost adiabatic and compositionally uniform; the more iron-rich inner solid core is a consequence of partial freezing of the outer core, and the energy release from this process sustains the earth's magnetic field; and the thermodynamic properties of the core are well constrained by the application of liquid-state theory to seismic and labroatory data.

  5. An Earth Penetrating Modeling Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Stokes, E; Yarrington, P; Glenn, L

    2005-06-21

    Documentation of a study to assess the capability of computer codes to predict lateral loads on earth penetrating projectiles under conditions of non-normal impact. Calculations simulated a set of small scale penetration tests into concrete targets with oblique faces at angles of 15 and 30 degrees to the line-of-flight. Predictive codes used by the various calculational teams cover a wide range of modeling approaches from approximate techniques, such as cavity expansion, to numerical methods, such as finite element codes. The modeling assessment was performed under the auspices of the Phenomenology Integrated Product Team (PIPT) for the Robust Nuclear Earth Penetrator Program (RNEP). Funding for the penetration experiments and modeling was provided by multiple earth penetrator programs.

  6. Diseases of the Earth's skin

    Science.gov (United States)

    The German Government's Scientific Advisory Council on Global Climate Change recently diagnosed a score of ailments of the “Earth's skin,” according to the German Research Service. Like numerous viral and bacterial diseases, many of the earthidermal diseases are named for the regions where scientists first discovered them. For some symptoms, the German Council has also recommended therapeutic treatments, such as terracing of slopes near rivers. It remains to be seen whether universities worldwide will start cranking out specialists in Earth dermatology. But judging by the condition of many regions of the world, it appears this field may offer great growth potential for the Earth sciences, which is welcome news in the current tight job market.

  7. When Walls are No Longer Barriers: Perception of Wall Height in Parkour

    OpenAIRE

    Taylor, J. Eric T.; Witt, Jessica; Sugovic, Mila

    2011-01-01

    Through training, skilled parkour athletes (traceurs) overcome everyday obstacles, such as walls, that are typically insurmountable. Traceurs and untrained novices estimated the height of walls and reported their anticipated ability to climb the wall. The traceurs perceived the walls as shorter than did novices. This result suggests that perception is scaled by the perceiver’s anticipated ability to act, and is consistent with the action-specific account of perception.

  8. Free oscillation of the Earth

    Directory of Open Access Journals (Sweden)

    Y. Abedini

    2000-06-01

    Full Text Available   This work is a study of the Earths free oscillations considering a merge of solid and liquid model. At the turn of 19th century Geophysicists presented the theory of the free oscillations for a self-gravitating, isotropic and compressible sphere. Assuming a steel structure for an Earth size sphere, they predicted a period of oscillation of about 1 hour. About 50 years later, the free oscillations of stars was studied by Cowling and others. They classified the oscillation modes of the stars into acoustic and gravity modes on the basis of their driving forces. These are pressure and buoyancy forces respectively. The earliest measurements for the period of the free oscillations of the Earth was made by Benyove from a study of Kamchathca earthquake. Since then, the Geophysicists have been trying to provide a theoretical basis for these measurements. Recently, the theory concerning oscillations of celestial fluids is extended by Sobouti to include the possible oscillations of the Earthlike bodies. Using the same technique, we study the free oscillations of a spherically symmetric, non-rotating and elastic model for the Earth.   We used the actual data of the Earths interior structure in our numerical calculations. Numerical results show that there exist three distinct oscillation modes namely acoustic, gravity and toroidal modes. These modes are driven by pressure, buoyancy and shear forces respectively. The shear force is due to the elastic properties of the solid part of the Earth. Our numerical results are consistent with the seismic data recorded from earthquake measurements.

  9. A Mission to Earth's Center

    Science.gov (United States)

    Olson, P.

    2016-12-01

    The last few decades have witnessed extraordinary progress on Earth's deep interior, particularly for Earth's core. Notable examples include seismic detection of fine structure and heterogeneity from the CMB to the depths of the inner core; improved constraints on the thermal regime and critical physical properties; direct experimental access to core pressures and temperatures; partial resolution of geomagnetic history into the deep past, new cosmochemical constraints on core formation, plus a first-order solution of the dynamo problem. Nevertheless, many fundamental questions about Earth's core remain unanswered, representing significant impediments to further understanding, not just of the Earth system, but also the interiors of other planets. A partial list of unsolved problems includes the composition of the core especially its light element inventory, the nature of heterogeneity in the core and its dynamical significance, quantifying heat and mass exchanges between core and mantle, the record of core evolution exemplified by inner core nucleation and the magnetic superchron cycle, and the role of core formation in governing Earth history. A more concerted and better-focused interdisciplinary effort is needed to resolve these long-standing problems, one that is comparable in its scale and structure to a planetary exploration mission. Such a Mission to Earth's Center would foster technological developments aimed specifically at these questions, such as seismic arrays designed for imaging the core, experimental capability for determining the phase diagram of the core, resolution of geomagnetic history into the deep past, plus next-generation dynamical models for the mantle, the core, and their interaction.

  10. External Insulation of Masonry Walls and Wood Framed Walls

    Energy Technology Data Exchange (ETDEWEB)

    Baker, P. [Building Science Corporation, Somerville, MA (United States)

    2013-01-01

    The use of exterior insulation on a building is an accepted and effective means to increase the overall thermal resistance of the assembly that also has other advantages of improved water management and often increased air tightness of building assemblies. For thin layers of insulation (1” to 1 ½”), the cladding can typically be attached directly through the insulation back to the structure. For thicker insulation layers, furring strips have been added as a cladding attachment location. This approach has been used in the past on numerous Building America test homes and communities (both new and retrofit applications), and has been proven to be an effective and durable means to provide cladding attachment. However, the lack of engineering data has been a problem for many designers, contractors, and code officials. This research project developed baseline engineering analysis to support the installation of thick layers of exterior insulation on existing masonry and frame walls. Furthermore, water management details necessary to integrate windows, doors, decks, balconies and roofs were created to provide guidance on the integration of exterior insulation strategies with other enclosure elements.

  11. External Insulation of Masonry Walls and Wood Framed Walls

    Energy Technology Data Exchange (ETDEWEB)

    Baker, P.

    2013-01-01

    The use of exterior insulation on a building is an accepted and effective means to increase the overall thermal resistance of the assembly that also has other advantages of improved water management and often increased air tightness of building assemblies. For thin layers of insulation (1" to 1 1/2"), the cladding can typically be attached directly through the insulation back to the structure. For thicker insulation layers, furring strips have been added as a cladding attachment location. This approach has been used in the past on numerous Building America test homes and communities (both new and retrofit applications), and has been proven to be an effective and durable means to provide cladding attachment. However, the lack of engineering data has been a problem for many designers, contractors, and code officials. This research project developed baseline engineering analysis to support the installation of thick layers of exterior insulation on existing masonry and frame walls. Furthermore, water management details necessary to integrate windows, doors, decks, balconies and roofs were created to provide guidance on the integration of exterior insulation strategies with other enclosure elements.

  12. Physical Processes Controlling Earth's Climate

    Science.gov (United States)

    Genio, Anthony Del

    2013-01-01

    As background for consideration of the climates of the other terrestrial planets in our solar system and the potential habitability of rocky exoplanets, we discuss the basic physics that controls the Earths present climate, with particular emphasis on the energy and water cycles. We define several dimensionless parameters relevant to characterizing a planets general circulation, climate and hydrological cycle. We also consider issues associated with the use of past climate variations as indicators of future anthropogenically forced climate change, and recent advances in understanding projections of future climate that might have implications for Earth-like exoplanets.

  13. Business earth stations for telecommunications

    Science.gov (United States)

    Morgan, Walter L.; Rouffet, Denis

    The current status of technology for small commercial satellite-communication earth stations is reviewed on the basis of an application study undertaken in the U.S. and Europe. Chapters are devoted to an overview of satellite communication networks, microterminal design and hardware implementation, microterminal applications, the advantages of microterminals, typical users, services provided, the U.S. market for small earth stations, network operators, and the economics of satellite and terrestrial communication services. Consideration is given to the operation of a microterminal network, standards and regulations, technological factors, space-segment requirements, and insurance aspects. Diagrams, graphs, tables of numerical data, and a glossary of terms are provided.

  14. China Rare Earth Market Review

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    August 20-31, 2011 Rare earth market did not show the sign of picking-up and remained stagnant recently. Most suppliers continued to decrease their quoted price, but leading producers in northern and southern China did not adjust their quoted price. Most rare earth plants in southern China had not yet resumed production. Quoted price of didymium products swung and the quoted prices of dysprosium-related products were slipping affected by weak demand. Inquiries for europium oxide were decreasing affected by the slow phosphor market.

  15. Early Earth(s) Across Time and Space

    Science.gov (United States)

    Mojzsis, S.

    2014-04-01

    The geochemical and cosmochemical record of our solar system is the baseline for exploring the question: "when could life appear on a world similar to our own?" Data arising from direct analysis of the oldest terrestrial rocks and minerals from the first 500 Myr of Earth history - termed the Hadean Eon - inform us about the timing for the establishment of a habitable silicate world. Liquid water is the key medium for life. The origin of water, and its interaction with the crust as revealed in the geologic record, guides our exploration for a cosmochemically Earth-like planets. From the time of primary planetary accretion to the start of the continuous rock record on Earth at ca. 3850 million years ago, our planet experienced a waning bolide flux that partially or entirely wiped out surface rocks, vaporized oceans, and created transient serpentinizing atmospheres. Arguably, "Early Earths" across the galaxy may start off as ice planets due to feeble insolation from their young stars, occasionally punctuated by steam atmospheres generated by cataclysmic impacts. Alternatively, early global environments conducive to life spanned from a benign surface zone to deep into crustal rocks and sediments. In some scenarios, nascent biospheres benefit from the exogenous delivery of essential bio-elements via leftovers of accretion, and the subsequent establishment of planetary-scale hydrothermal systems. If what is now known about the early dynamical regime of the Earth serves as any measure of the potential habitability of worlds across space and time, several key boundary conditions emerge. These are: (i) availability and long-term stability of liquid water; (ii) presence of energy resources; (iii) accessibility of organic raw materials; (iv) adequate inventory of radioisotopes to drive internal heating; (v) gross compositional parameters such as mantle/core mass ratio, and (vi) P-T conditions at or near the surface suitable for sustaining biological activity. Life could

  16. Nondestructive Evaluation of Historic Hakka Rammed Earth Structures

    Directory of Open Access Journals (Sweden)

    Yanhao Li

    2013-01-01

    Full Text Available The in-service Hakka rammed earth buildings, in the Fujian Province of China, are unique in design and performance. Their UNESCO’s inscription as World Heritage sites recognizes their artistic, cultural, social and historic significance. Sponsored by the National Science Foundation of the United States, the authors have examined the engineering values of these buildings in terms of comfortable living at low energy consumption, sustainability and durability. The objective of this study was to better understand the thermo-mechanical and aging responses of Hakka earth buildings under thermal and earthquake loads through nondestructive field evaluation, including full-scale roof truss and floor testing, laboratory testing of field samples and finite element modeling. This paper presents our observations and findings from the field nondestructive evaluations with emphasis on the integrity of the rammed earth outer walls and inner wood structures, as well as the thermal comfort of living in these buildings, while a second paper presents the results from the material characterization of field samples and the structural responses of a representative building under earthquake induced loads through finite element analysis.

  17. Results obtained during wall breaching research

    CSIR Research Space (South Africa)

    Hattingh, S

    2008-11-01

    Full Text Available the operator on the charge side of the building. Test walls (double and single brick walls) 3m wide by 2m height were used for testing different charges and their effects due to the different charges. The loop charge was found to be the most promising solution...

  18. Risk Assessment of Energy-Efficient Walls

    Energy Technology Data Exchange (ETDEWEB)

    Pallin, Simon B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hun, Diana E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jackson, Roderick K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kehrer, Manfred [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-12-01

    This multi-year project aims to provide the residential construction industry with energy-efficient wall designs that are moisture durable. The present work focused on the initial step of this project, which is to develop a moisture durability protocol that identifies energy efficient wall designs that have a low probability of experiencing moisture problems.

  19. Full size testing of sheet pile walls

    NARCIS (Netherlands)

    Kuilen, J.W.G. van de; Linden, M.L.R. van der; Katsma, H.; Stolle, P.

    1996-01-01

    Azobé (Lophira alata) is widely used in timber sheet pile walls in the Netherlands. The boards in these walls are coupled and therefore load-sharing can be expected. A simulation model based on the finite element method DIANA (DIANA, 1992) was developed and load-sharing could be calculated. To check

  20. Moduli of monopole walls and amoebas

    Science.gov (United States)

    Cherkis, Sergey A.; Ward, Richard S.

    2012-05-01

    We study doubly-periodic monopoles, also called monopole walls, determining their spectral data and computing the dimensions of their moduli spaces. Using spectral data we identify the moduli, and compare our results with a perturbative analysis. We also identify an SL(2, {Z}) action on monopole walls, in which the S transformation corresponds to the Nahm transform.