Sample records for build body shells

  1. 41 CFR 102-85.120 - What is shell Rent?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false What is shell Rent? 102... GSA SPACE Rent Charges § 102-85.120 What is shell Rent? Shell Rent is that portion of GSA Rent charged for the building envelope and land. (See § 102-85.35 for the definition of building shell.) ...

  2. Building Atoms Shell by Shell.

    ERIC Educational Resources Information Center

    Sussman, Beverly

    1993-01-01

    Describes an atom-building activity where students construct three-dimensional models of atoms using a styrofoam ball as the nucleus and pom-poms, gum drops, minimarshmallows, or other small items of two different colors to represent protons and neutrons attached. Rings of various sizes with pom-poms attached represent electron shells and…

  3. ControlShell: A real-time software framework

    NASA Technical Reports Server (NTRS)

    Schneider, Stanley A.; Chen, Vincent W.; Pardo-Castellote, Gerardo

    1994-01-01

    The ControlShell system is a programming environment that enables the development and implementation of complex real-time software. It includes many building tools for complex systems, such as a graphical finite state machine (FSM) tool to provide strategic control. ControlShell has a component-based design, providing interface definitions and mechanisms for building real-time code modules along with providing basic data management. Some of the system-building tools incorporated in ControlShell are a graphical data flow editor, a component data requirement editor, and a state-machine editor. It also includes a distributed data flow package, an execution configuration manager, a matrix package, and an object database and dynamic binding facility. This paper presents an overview of ControlShell's architecture and examines the functions of several of its tools.

  4. Deriving the nuclear shell model from first principles

    NASA Astrophysics Data System (ADS)

    Barrett, Bruce R.; Dikmen, Erdal; Vary, James P.; Maris, Pieter; Shirokov, Andrey M.; Lisetskiy, Alexander F.

    2014-09-01

    The results of an 18-nucleon No Core Shell Model calculation, performed in a large basis space using a bare, soft NN interaction, can be projected into the 0 ℏω space, i.e., the sd -shell. Because the 16 nucleons in the 16O core are frozen in the 0 ℏω space, all the correlations of the 18-nucleon system are captured by the two valence, sd -shell nucleons. By the projection, we obtain microscopically the sd -shell 2-body effective interactions, the core energy and the sd -shell s.p. energies. Thus, the input for standard shell-model calculations can be determined microscopically by this approach. If the same procedure is then applied to 19-nucleon systems, the sd -shell 3-body effective interactions can also be obtained, indicating the importance of these 3-body effective interactions relative to the 2-body effective interactions. Applications to A = 19 and heavier nuclei with different intrinsic NN interactions will be presented and discussed. The results of an 18-nucleon No Core Shell Model calculation, performed in a large basis space using a bare, soft NN interaction, can be projected into the 0 ℏω space, i.e., the sd -shell. Because the 16 nucleons in the 16O core are frozen in the 0 ℏω space, all the correlations of the 18-nucleon system are captured by the two valence, sd -shell nucleons. By the projection, we obtain microscopically the sd -shell 2-body effective interactions, the core energy and the sd -shell s.p. energies. Thus, the input for standard shell-model calculations can be determined microscopically by this approach. If the same procedure is then applied to 19-nucleon systems, the sd -shell 3-body effective interactions can also be obtained, indicating the importance of these 3-body effective interactions relative to the 2-body effective interactions. Applications to A = 19 and heavier nuclei with different intrinsic NN interactions will be presented and discussed. Supported by the US NSF under Grant No. 0854912, the US DOE under Grants Nos. DESC0008485 and DE-FG02-87ER40371, the Higher Education Council of Turkey(YOK), and the Ministry of Education and Science of Russian Fed. under contracts P521 and 14.v37.21.1297.

  5. 65. SAC Minuteman Missile "shell", mounted for permanent display in ...

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

    65. SAC Minuteman Missile "shell", mounted for permanent display in front lawn, building 500, looking east - Offutt Air Force Base, Strategic Air Command Headquarters & Command Center, Headquarters Building, 901 SAC Boulevard, Bellevue, Sarpy County, NE

  6. Multiple lead seal assembly for a liquid-metal-cooled fast-breeder nuclear reactor

    DOEpatents

    Hutter, Ernest; Pardini, John A.

    1977-03-15

    A reusable multiple lead seal assembly provides leak-free passage of stainless-steel-clad instrument leads through the cover on the primary tank of a liquid-metal-cooled fast-breeder nuclear reactor. The seal isolates radioactive argon cover gas and sodium vapor within the primary tank from the exterior atmosphere and permits reuse of the assembly and the stainless-steel-clad instrument leads. Leads are placed in flutes in a seal body, and a seal shell is then placed around the seal body. Circumferential channels in the body and inner surface of the shell are contiguous and together form a conduit which intersects each of the flutes, placing them in communication with a port through the wall of the seal shell. Liquid silicone rubber sealant is injected into the flutes through the port and conduit; the sealant fills the space in the flutes not occupied by the leads themselves and dries to a rubbery hardness. A nut, threaded onto a portion of the seal body not covered by the seal shell, jacks the body out of the shell and shears the sealant without damage to the body, shell, or leads. The leads may then be removed from the body. The sheared sealant is cleaned from the body, leads, and shell and the assembly may then be reused with the same or different leads.

  7. Off-energy-shell p-p scattering at sub-Coulomb energies via the Trojan horse method

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tumino, A.; Dipartimento di Metodologie Fisiche e Chimiche per l'Ingegneria, Universita di Catania, Catania; Universita Kore di Enna, Enna

    2008-12-15

    Two-proton scattering at sub-Coulomb energies has been measured indirectly via the Trojan horse method applied to the p + d{yields}p + p + n reaction to investigate off-energy shell effects for scattering processes. The three-body experiment was performed at 5 and 4.7 MeV corresponding to a p-p relative energy ranging from 80 to 670 keV. The free p-p cross section exhibits a deep minimum right within this relative energy region due to Coulomb plus nuclear destructive interference. No minimum occurs instead in the Trojan horse p-p cross section, which was extracted by employing a simple plane-wave impulse approximation. A detailedmore » formalism was developed to build up the expression of the theoretical half-off-shell p-p cross section. Its behavior agrees with the Trojan horse data and in turn formally fits the n-n, n-p, and nuclear p-p cross sections given the fact that in its expression the Coulomb amplitude is negligible with respect to the nuclear one. These results confirm the Trojan horse suppression of the Coulomb amplitude for scattering due to the off-shell character of the process.« less

  8. Revisiting chameleon gravity: Thin-shell and no-shell fields with appropriate boundary conditions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tamaki, Takashi; Department of Physics, Rikkyo University, Toshima, Tokyo 171-8501; Tsujikawa, Shinji

    2008-10-15

    We derive analytic solutions of a chameleon scalar field {phi} that couples to a nonrelativistic matter in the weak gravitational background of a spherically symmetric body, paying particular attention to a field mass m{sub A} inside of the body. The standard thin-shell field profile is recovered by taking the limit m{sub A}r{sub c}{yields}{infinity}, where r{sub c} is a radius of the body. We show the existence of 'no-shell' solutions where the field is nearly frozen in the whole interior of the body, which does not necessarily correspond to the 'zero-shell' limit of thin-shell solutions. In the no-shell case, under themore » condition m{sub A}r{sub c}>>1, the effective coupling of {phi} with matter takes the same asymptotic form as that in the thin-shell case. We study experimental bounds coming from the violation of equivalence principle as well as solar-system tests for a number of models including f(R) gravity and find that the field is in either the thin-shell or the no-shell regime under such constraints, depending on the shape of scalar-field potentials. We also show that, for the consistency with local gravity constraints, the field at the center of the body needs to be extremely close to the value {phi}{sub A} at the extremum of an effective potential induced by the matter coupling.« less

  9. Quartetting in even-even and odd-odd N=Z nuclei

    NASA Astrophysics Data System (ADS)

    Sambataro, M.; Sandulescu, N.

    2018-02-01

    We report on a microscopic description of even-even N = Z nuclei in a formalism of quartets. Quartets are four-body correlated structures characterized by isospin T and angular momentum J. We show that the ground state correlations induced by a realistic shell model interaction can be well accounted for in terms of a restricted set of T = 0 low-J quartets, the J = 0 one playing by far a leading role among them. A conceptually similar description of odd-odd self-conjugate nuclei is given in terms of two distinct families of building blocks, one formed by the same T = 0 quartets employed for the even-even systems and the other by collective pairs with either T = 0 or T = 1. Some applications of this formalism are discussed for nuclei in the sd shell.

  10. Biometric studies on the bivalves Astarte elliptica, A. borealis and A. montagui in Kiel Bay (Western Baltic Sea)

    NASA Astrophysics Data System (ADS)

    Schaefer, R.; Trutschler, K.; Rumohr, H.

    1985-09-01

    The three Astarte species were studied in June 1983 at two sites in Kiel Bay, “Süderfahrt” and “Schleimünde”, at 20 m depth. Shell length to live wet weight correlations are given for all three species; for A. elliptica also shell-free dry weight, shell dry weight, ash-free dry weight of the soft body and ash-free dry weight of the shell are recorded as functions of the shell length. In the logarithmic length/weight regression analysis the coefficients of slope for A. elliptica and A. borealis are 3. For A. montagui, that coefficient is significantly greater than 3. Weight conversion factors, calculated for A. elliptica, revealed a mean weight composition of 31.5 % water in the mantle cavity and tissue water, 64.5 % shell ash, 2.1 % organic content of shell, 1.7 % organic content of the soft body and 0.4 % ash of the soft body. An isometric growth of shell length and shell breadth is confirmed for A. borealis, while A. montagui exhibits positive allometric shell growth and changes its shape during life.

  11. Assembly of Robust Bacterial Microcompartment Shells Using Building Blocks from an Organelle of Unknown Function

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lassila, JK; Bernstein, SL; Kinney, JN

    Bacterial microconnpartnnents (BMCs) sequester enzymes from the cytoplasmic environment by encapsulation inside a selectively permeable protein shell. Bioinformatic analyses indicate that many bacteria encode BMC clusters of unknown function and with diverse combinations of shell proteins. The genome of the halophilic myxobacterium Haliangium ochraceum encodes one of the most atypical sets of shell proteins in terms of composition and primary structure. We found that microconnpartnnent shells could be purified in high yield when all seven H. ochraceum BMC shell genes were expressed from a synthetic operon in Escherichia coll. These shells differ substantially from previously isolated shell systems in thatmore » they are considerably smaller and more homogeneous, with measured diameters of 39 2 nm. The size and nearly uniform geometry allowed the development of a structural model for the shells composed of 260 hexagonal units and 13 hexagons per icosahedral face. We found that new proteins could be recruited to the shells by fusion to a predicted targeting peptide sequence, setting the stage for the use of these remarkably homogeneous shells for applications such as three-dimensional scaffolding and the construction of synthetic BMCs. Our results demonstrate the value of selecting from the diversity of BMC shell building blocks found in genomic sequence data for the construction of novel compartments. (C) 2014 Elsevier Ltd. All rights reserved.« less

  12. Microscopic Shell Model Calculations for sd-Shell Nuclei

    NASA Astrophysics Data System (ADS)

    Barrett, Bruce R.; Dikmen, Erdal; Maris, Pieter; Shirokov, Andrey M.; Smirnova, Nadya A.; Vary, James P.

    Several techniques now exist for performing detailed and accurate calculations of the structure of light nuclei, i.e., A ≤ 16. Going to heavier nuclei requires new techniques or extensions of old ones. One of these is the so-called No Core Shell Model (NCSM) with a Core approach, which involves an Okubo-Lee-Suzuki (OLS) transformation of a converged NCSM result into a single major shell, such as the sd-shell. The obtained effective two-body matrix elements can be separated into core and single-particle (s.p.) energies plus residual two-body interactions, which can be used for performing standard shell-model (SSM) calculations. As an example, an application of this procedure will be given for nuclei at the beginning ofthe sd-shell.

  13. A software architecture for automating operations processes

    NASA Technical Reports Server (NTRS)

    Miller, Kevin J.

    1994-01-01

    The Operations Engineering Lab (OEL) at JPL has developed a software architecture based on an integrated toolkit approach for simplifying and automating mission operations tasks. The toolkit approach is based on building adaptable, reusable graphical tools that are integrated through a combination of libraries, scripts, and system-level user interface shells. The graphical interface shells are designed to integrate and visually guide a user through the complex steps in an operations process. They provide a user with an integrated system-level picture of an overall process, defining the required inputs and possible output through interactive on-screen graphics. The OEL has developed the software for building these process-oriented graphical user interface (GUI) shells. The OEL Shell development system (OEL Shell) is an extension of JPL's Widget Creation Library (WCL). The OEL Shell system can be used to easily build user interfaces for running complex processes, applications with extensive command-line interfaces, and tool-integration tasks. The interface shells display a logical process flow using arrows and box graphics. They also allow a user to select which output products are desired and which input sources are needed, eliminating the need to know which program and its associated command-line parameters must be executed in each case. The shells have also proved valuable for use as operations training tools because of the OEL Shell hypertext help environment. The OEL toolkit approach is guided by several principles, including the use of ASCII text file interfaces with a multimission format, Perl scripts for mission-specific adaptation code, and programs that include a simple command-line interface for batch mode processing. Projects can adapt the interface shells by simple changes to the resources configuration file. This approach has allowed the development of sophisticated, automated software systems that are easy, cheap, and fast to build. This paper will discuss our toolkit approach and the OEL Shell interface builder in the context of a real operations process example. The paper will discuss the design and implementation of a Ulysses toolkit for generating the mission sequence of events. The Sequence of Events Generation (SEG) system provides an adaptable multimission toolkit for producing a time-ordered listing and timeline display of spacecraft commands, state changes, and required ground activities.

  14. 9. Historic American Buildings Survey E. W. Russell, Photographer, February ...

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

    9. Historic American Buildings Survey E. W. Russell, Photographer, February 28, 1935 MAIN BUILDING (ADMINISTRATION) WEST - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

  15. Body size evolution of a shell-brooding cichlid fish from Lake Tanganyika.

    PubMed

    Takahashi, T; Ota, K

    2016-12-01

    The substrate-brooding cichlid fish Telmatochromis temporalis in Lake Tanganyika demonstrates a simple example of ecological speciation between normal and dwarf morphs through divergent natural selection on body size. The dwarf morph most likely evolved from the ancestral normal morph; therefore, elucidating the evolution of its small body size is a key to understanding this ecological speciation event. Previous studies suggest that the small body size of the dwarf morph is an adaptation to the use of empty snail shells as shelters (males) and spawning sites (females), but this idea has not been fully evaluated. Combining original and previously published information, this study compared likelihood values to determine the primary factor that would be responsible for regulating the body size of the dwarf morph. Male body size is most likely regulated by the ability to turn within shells, which may influence the predation avoidance of adult fish. Females are smaller than males, and their body size is most likely regulated by the ability to lay eggs in the small spaces within shells close to the shell apices where predation risk on eggs is lower. This study provides new evidence supporting the hypothesis that different natural selection factors affected body size of the different sexes of the dwarf morph, which has not been reported in other animal species. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

  16. Vibrio cholerae Colonization of Soft-Shelled Turtles

    PubMed Central

    Wang, Jiazheng; Yan, Meiying; Gao, He; Lu, Xin

    2017-01-01

    ABSTRACT Vibrio cholerae is an important human pathogen and environmental microflora species that can both propagate in the human intestine and proliferate in zooplankton and aquatic organisms. Cholera is transmitted through food and water. In recent years, outbreaks caused by V. cholerae-contaminated soft-shelled turtles, contaminated mainly with toxigenic serogroup O139, have been frequently reported, posing a new foodborne disease public health problem. In this study, the colonization by toxigenic V. cholerae on the body surfaces and intestines of soft-shelled turtles was explored. Preferred colonization sites on the turtle body surfaces, mainly the carapace and calipash of the dorsal side, were observed for the O139 and O1 strains. Intestinal colonization was also found. The colonization factors of V. cholerae played different roles in the colonization of the soft-shelled turtle's body surface and intestine. Mannose-sensitive hemagglutinin (MSHA) of V. cholerae was necessary for body surface colonization, but no roles were found for toxin-coregulated pili (TCP) or N-acetylglucosamine-binding protein A (GBPA). Both TCP and GBPA play important roles for colonization in the intestine, whereas the deletion of MSHA revealed only a minor colonization-promoting role for this factor. Our study demonstrated that V. cholerae can colonize the surfaces and the intestines of soft-shelled turtles and indicated that the soft-shelled turtles played a role in the transmission of cholera. In addition, this study showed that the soft-shelled turtle has potential value as an animal model in studies of the colonization and environmental adaption mechanisms of V. cholerae in aquatic organisms. IMPORTANCE Cholera is transmitted through water and food. Soft-shelled turtles contaminated with Vibrio cholerae (commonly the serogroup O139 strains) have caused many foodborne infections and outbreaks in recent years, and they have become a foodborne disease problem. Except for epidemiological investigations, no experimental studies have demonstrated the colonization by V. cholerae on soft-shelled turtles. The present studies will benefit our understanding of the interaction between V. cholerae and the soft-shelled turtle. We demonstrated the colonization by V. cholerae on the soft-shelled turtle's body surface and in the intestine and revealed the different roles of major V. cholerae factors for colonization on the body surface and in the intestine. Our work provides experimental evidence for the role of soft-shelled turtles in cholera transmission. In addition, this study also shows the possibility for the soft-shelled turtle to serve as a new animal model for studying the interaction between V. cholerae and aquatic hosts. PMID:28600312

  17. Vibrio cholerae Colonization of Soft-Shelled Turtles.

    PubMed

    Wang, Jiazheng; Yan, Meiying; Gao, He; Lu, Xin; Kan, Biao

    2017-07-15

    Vibrio cholerae is an important human pathogen and environmental microflora species that can both propagate in the human intestine and proliferate in zooplankton and aquatic organisms. Cholera is transmitted through food and water. In recent years, outbreaks caused by V. cholerae -contaminated soft-shelled turtles, contaminated mainly with toxigenic serogroup O139, have been frequently reported, posing a new foodborne disease public health problem. In this study, the colonization by toxigenic V. cholerae on the body surfaces and intestines of soft-shelled turtles was explored. Preferred colonization sites on the turtle body surfaces, mainly the carapace and calipash of the dorsal side, were observed for the O139 and O1 strains. Intestinal colonization was also found. The colonization factors of V. cholerae played different roles in the colonization of the soft-shelled turtle's body surface and intestine. Mannose-sensitive hemagglutinin (MSHA) of V. cholerae was necessary for body surface colonization, but no roles were found for toxin-coregulated pili (TCP) or N -acetylglucosamine-binding protein A (GBPA). Both TCP and GBPA play important roles for colonization in the intestine, whereas the deletion of MSHA revealed only a minor colonization-promoting role for this factor. Our study demonstrated that V. cholerae can colonize the surfaces and the intestines of soft-shelled turtles and indicated that the soft-shelled turtles played a role in the transmission of cholera. In addition, this study showed that the soft-shelled turtle has potential value as an animal model in studies of the colonization and environmental adaption mechanisms of V. cholerae in aquatic organisms. IMPORTANCE Cholera is transmitted through water and food. Soft-shelled turtles contaminated with Vibrio cholerae (commonly the serogroup O139 strains) have caused many foodborne infections and outbreaks in recent years, and they have become a foodborne disease problem. Except for epidemiological investigations, no experimental studies have demonstrated the colonization by V. cholerae on soft-shelled turtles. The present studies will benefit our understanding of the interaction between V. cholerae and the soft-shelled turtle. We demonstrated the colonization by V. cholerae on the soft-shelled turtle's body surface and in the intestine and revealed the different roles of major V. cholerae factors for colonization on the body surface and in the intestine. Our work provides experimental evidence for the role of soft-shelled turtles in cholera transmission. In addition, this study also shows the possibility for the soft-shelled turtle to serve as a new animal model for studying the interaction between V. cholerae and aquatic hosts. Copyright © 2017 American Society for Microbiology.

  18. 15. Historic American Buildings Survey E. W. Russell, Photographer, May ...

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

    15. Historic American Buildings Survey E. W. Russell, Photographer, May 8, 1936 CLOSE-UP OF CORNICE ON REAR OF BUILDING - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

  19. Applications to car bodies - Generalized layout design of three-dimensional shells

    NASA Technical Reports Server (NTRS)

    Fukushima, Junichi; Suzuki, Katsuyuki; Kikuchi, Noboru

    1993-01-01

    We shall describe applications of the homogenization method, formulated in Part 1, to design layout of car bodies represented by three-dimensional shell structures based on a multi-loading optimization.

  20. Flexible configuration-interaction shell-model many-body solver

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Johnson, Calvin W.; Ormand, W. Erich; McElvain, Kenneth S.

    BIGSTICK Is a flexible configuration-Interaction open-source shell-model code for the many-fermion problem In a shell model (occupation representation) framework. BIGSTICK can generate energy spectra, static and transition one-body densities, and expectation values of scalar operators. Using the built-in Lanczos algorithm one can compute transition probabflity distributions and decompose wave functions into components defined by group theory.

  1. Requirements for Weatherproofing Thin Shell Concrete Roofs. Proceedings of the Conference of Building Research Institute, Division of Engineering and Industrial Research (Spring 1961).

    ERIC Educational Resources Information Center

    National Academy of Sciences - National Research Council, Washington, DC.

    Topics discussed include--(1) requirements for weatherproofing and sealant materials for thin shell concrete roof, (2) effect of physical factors on weatherproofing of thin shell concrete roofs, (3) problems and limitations imposed by thin shell concrete roofs and their effect on weatherproofing and sealant materials, and (4) properties and uses…

  2. 1. Historic American Buildings Survey COPIED E. W. Russell, ...

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

    1. Historic American Buildings Survey COPIED - E. W. Russell, Photographer, August 31, 1936 75TH ANNIVERSARY YEARBOOK (NOT COPYRIGHT) - VIEW OF ORIGINAL BUILDING - Spring Hill College, Original Building, Old Shell Road, Spring Hill, Mobile County, AL

  3. Multibody dynamic analysis using a rotation-free shell element with corotational frame

    NASA Astrophysics Data System (ADS)

    Shi, Jiabei; Liu, Zhuyong; Hong, Jiazhen

    2018-03-01

    Rotation-free shell formulation is a simple and effective method to model a shell with large deformation. Moreover, it can be compatible with the existing theories of finite element method. However, a rotation-free shell is seldom employed in multibody systems. Using a derivative of rigid body motion, an efficient nonlinear shell model is proposed based on the rotation-free shell element and corotational frame. The bending and membrane strains of the shell have been simplified by isolating deformational displacements from the detailed description of rigid body motion. The consistent stiffness matrix can be obtained easily in this form of shell model. To model the multibody system consisting of the presented shells, joint kinematic constraints including translational and rotational constraints are deduced in the context of geometric nonlinear rotation-free element. A simple node-to-surface contact discretization and penalty method are adopted for contacts between shells. A series of analyses for multibody system dynamics are presented to validate the proposed formulation. Furthermore, the deployment of a large scaled solar array is presented to verify the comprehensive performance of the nonlinear shell model.

  4. 33. Historic American Buildings Survey E. W. Russell, Photographer, May ...

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

    33. Historic American Buildings Survey E. W. Russell, Photographer, May 7, 1936 VIEW OF STAIR FROM 2nd STORY HALL, W. END OF BUILDING - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

  5. Optimizing Distributed Energy Resources and building retrofits with the strategic DER-CAModel

    DOE PAGES

    Stadler, M.; Groissböck, M.; Cardoso, G.; ...

    2014-08-05

    The pressuring need to reduce the import of fossil fuels as well as the need to dramatically reduce CO 2 emissions in Europe motivated the European Commission (EC) to implement several regulations directed to building owners. Most of these regulations focus on increasing the number of energy efficient buildings, both new and retrofitted, since retrofits play an important role in energy efficiency. Overall, this initiative results from the realization that buildings will have a significant impact in fulfilling the 20/20/20-goals of reducing the greenhouse gas emissions by 20%, increasing energy efficiency by 20%, and increasing the share of renewables tomore » 20%, all by 2020. The Distributed Energy Resources Customer Adoption Model (DER-CAM) is an optimization tool used to support DER investment decisions, typically by minimizing total annual costs or CO 2 emissions while providing energy services to a given building or microgrid site. This document shows enhancements made to DER-CAM to consider building retrofit measures along with DER investment options. Specifically, building shell improvement options have been added to DER-CAM as alternative or complementary options to investments in other DER such as PV, solar thermal, combined heat and power, or energy storage. The extension of the mathematical formulation required by the new features introduced in DER-CAM is presented and the resulting model is demonstrated at an Austrian Campus building by comparing DER-CAM results with and without building shell improvement options. Strategic investment results are presented and compared to the observed investment decision at the test site. Results obtained considering building shell improvement options suggest an optimal weighted average U value of about 0.53 W/(m 2K) for the test site. This result is approximately 25% higher than what is currently observed in the building, suggesting that the retrofits made in 2002 were not optimal. Furthermore, the results obtained with DER-CAM illustrate the complexity of interactions between DER and passive measure options, showcasing the need for a holistic optimization approach to effectively optimize energy costs and CO 2 emissions. Lastly, the simultaneous optimization of building shell improvements and DER investments enables building owners to take one step further towards nearly zero energy buildings (nZEB) or nearly zero carbon emission buildings (nZCEB), and therefore support the 20/20/20 goals.« less

  6. Optimizing Distributed Energy Resources and building retrofits with the strategic DER-CAModel

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Stadler, M.; Groissböck, M.; Cardoso, G.

    The pressuring need to reduce the import of fossil fuels as well as the need to dramatically reduce CO 2 emissions in Europe motivated the European Commission (EC) to implement several regulations directed to building owners. Most of these regulations focus on increasing the number of energy efficient buildings, both new and retrofitted, since retrofits play an important role in energy efficiency. Overall, this initiative results from the realization that buildings will have a significant impact in fulfilling the 20/20/20-goals of reducing the greenhouse gas emissions by 20%, increasing energy efficiency by 20%, and increasing the share of renewables tomore » 20%, all by 2020. The Distributed Energy Resources Customer Adoption Model (DER-CAM) is an optimization tool used to support DER investment decisions, typically by minimizing total annual costs or CO 2 emissions while providing energy services to a given building or microgrid site. This document shows enhancements made to DER-CAM to consider building retrofit measures along with DER investment options. Specifically, building shell improvement options have been added to DER-CAM as alternative or complementary options to investments in other DER such as PV, solar thermal, combined heat and power, or energy storage. The extension of the mathematical formulation required by the new features introduced in DER-CAM is presented and the resulting model is demonstrated at an Austrian Campus building by comparing DER-CAM results with and without building shell improvement options. Strategic investment results are presented and compared to the observed investment decision at the test site. Results obtained considering building shell improvement options suggest an optimal weighted average U value of about 0.53 W/(m 2K) for the test site. This result is approximately 25% higher than what is currently observed in the building, suggesting that the retrofits made in 2002 were not optimal. Furthermore, the results obtained with DER-CAM illustrate the complexity of interactions between DER and passive measure options, showcasing the need for a holistic optimization approach to effectively optimize energy costs and CO 2 emissions. Lastly, the simultaneous optimization of building shell improvements and DER investments enables building owners to take one step further towards nearly zero energy buildings (nZEB) or nearly zero carbon emission buildings (nZCEB), and therefore support the 20/20/20 goals.« less

  7. 17. Historic American Buildings Survey E. W. Russell, Photographer, May ...

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

    17. Historic American Buildings Survey E. W. Russell, Photographer, May 7, 1936 GENERAL VIEW OF PORTICO (OR ARCADE) LOOKING WEST, 1st FLOOR OF ADMINISTRATION BUILDING - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

  8. 41. Historic American Buildings Survey E. W. Russell, Photographer, May ...

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

    41. Historic American Buildings Survey E. W. Russell, Photographer, May 7, 1936 CORNICE AROUND ROTUNDA WALL, THIRD FLOOR - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

  9. 3. Historic American Buildings Survey E. W. Russell, Photographer, May ...

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

    3. Historic American Buildings Survey E. W. Russell, Photographer, May 7, 1936 NORTH ELEVATION (FRONT) LOOKING SOUTH EAST - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

  10. 35. Historic American Buildings Survey E. W. Russell, Photographer, May ...

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

    35. Historic American Buildings Survey E. W. Russell, Photographer, May 7, 1936 ROTUNDA, THIRD FLOOR, LOOKING W. FROM E. HALLWAY - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

  11. 25. Historic American Buildings Survey E. W. Russell, Photographer, May ...

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

    25. Historic American Buildings Survey E. W. Russell, Photographer, May 7, 1936 FRONT ENTRANCE DOOR TO WEST OF MAIN ENTRANCE - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

  12. 39. Historic American Buildings Survey E. W. Russell, Photographer, May ...

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

    39. Historic American Buildings Survey E. W. Russell, Photographer, May 7, 1936 CLOSE-UP OF ROTUNDA BALUSTRADE, THIRD FLOOR - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

  13. 21. Historic American Buildings Survey E. W. Russell, Photographer, May ...

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

    21. Historic American Buildings Survey E. W. Russell, Photographer, May 7, 1936 CLOSE-UP OF IRON COLUMN CAP, SOUTH PORTICO - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

  14. 36. Historic American Buildings Survey E. W. Russell, Photographer, May ...

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

    36. Historic American Buildings Survey E. W. Russell, Photographer, May 7, 1936 ROTUNDA, 3rd FLOOR, SHOWING N. HALL - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

  15. 24. Historic American Buildings Survey E. W. Russell, Photographer, May ...

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

    24. Historic American Buildings Survey E. W. Russell, Photographer, May 7, 1936 N. DOOR OPENING ON PORTICO (OR ARCADE) - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

  16. 6. Historic American Buildings Survey E. W. Russell, Photographer, May ...

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

    6. Historic American Buildings Survey E. W. Russell, Photographer, May 8, 1936 SOUTH ELEVATION OF W END WING (REAR) - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

  17. Ray Solutions to Sound Scattering by Complex Bodies: Application to Zooplankton.

    DTIC Science & Technology

    2000-02-14

    marine snail that swims (elastic shelled body), and (c) siphonophore , a gas- bearing animal (fluid-like tissue containing gas). From Ref. 1...1- LU -100 ^/Vyvv -100 EUPHAUSIID GASTROPOD SIPHONOPHORE 400 500 600 700 800 400 500 600 700 800 FREQUENCY (kHz) FIGURE 2 Target...whose bodies consist of an irregular elastic shell with an opening, and a siphonophore whose body is mostly a fluid-like tissue that contains a

  18. 2. Historic American Buildings Survey Copied by E. W. Russell, ...

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

    2. Historic American Buildings Survey Copied by E. W. Russell, Photographer, August 31, 1936 75TH ANNIVERSARY YEARBOOK (NOT COPYRIGHT) - REAR OF BUILDING BEFORE REINFORCED CONCRETE BALCONIES WERE ADDED - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

  19. 1. Historic American Buildings Survey Copied by E. W. Russell, ...

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

    1. Historic American Buildings Survey Copied by E. W. Russell, Photographer, August 31, 1936 75TH ANNIVERSARY YEARBOOK (NOT COPYRIGHT) - FRONT OF MAIN BUILDING BEFORE CLOISTER ARCADE WAS ADDED - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

  20. 30. Historic American Buildings Survey E. W. Russell, Photographer, May ...

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

    30. Historic American Buildings Survey E. W. Russell, Photographer, May 8, 1936 STAIR IN HALL TOWARDS REAR, W. EXTENSION, 1st FLOOR - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

  1. 20. Historic American Buildings Survey E. W. Russell, Photographer, May ...

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

    20. Historic American Buildings Survey E. W. Russell, Photographer, May 7, 1936 CLOSE-UP OF STUCCO PORTICO COLUMN (SOUTH) FIRST FLOOR - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

  2. 22. Historic American Buildings Survey E. W. Russell, Photographer, May ...

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

    22. Historic American Buildings Survey E. W. Russell, Photographer, May 7, 1936 BASE OF IRON COLUMN TO PORTICO (SOUTH) FIRST FLOOR - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

  3. 18. Historic American Buildings Survey E. W. Russell, Photographer, May ...

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

    18. Historic American Buildings Survey E. W. Russell, Photographer, May 7, 1936 VIEW OF PORTICO COLUMNS LOOKING N. E., 1st FLOOR - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

  4. 5. Historic American Buildings Survey E. W. Russell, Photographer, February ...

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

    5. Historic American Buildings Survey E. W. Russell, Photographer, February 28, 1935 REAR VIEW OF MAIN BLDG. S.W. (REAR FACES S.) - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

  5. van der Waals three-body force shell model (VTSM) for the lattice dynamical studies of thallous bromide

    NASA Astrophysics Data System (ADS)

    Tiwari, Sarvesh K.; Pandey, L. K.; Shukla, Lal Ji; Upadhyaya, K. S.

    2009-12-01

    The van der Waals three-body force shell model (VTSM) has been developed by modifying the three-body force shell model (TSM) for the lattice dynamics of ionic crystals with cesium chloride (CsCl) structure. This new model incorporates van der Waals interactions along with long-range Coulomb interactions, three-body interactions and short-range second neighbour interactions in the framework of a rigid shell model (RSM). In the present paper, VTSM has been used to study the lattice dynamics of thallous bromide (TlBr), from which adequacy of VTSM has been established. A comparative study of the dynamical behaviour of TlBr has also been done between the present model and TSM, the model over which modification has been made to obtain the present model VTSM. Good agreement has been observed between the theoretical and experimental results, which give confidence that it is an appropriate model for the complete description of ionic crystals with CsCl structure.

  6. Invertebrates and Plants :: NOAA Fisheries

    Science.gov Websites

    from Latin as "stomach foot." Mollusks are soft-bodied animals that may have a hard external shell (composed by secreting calcium carbonate), a hard internal shell, or no shell at all. Mollusks are

  7. 7. Detail view west of Arctic Chamber wind tunnel shell ...

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

    7. Detail view west of Arctic Chamber wind tunnel shell (typical) in east elevation. - Natick Research & Development Laboratories, Climatic Chambers Building, U.S. Army Natick Research, Development & Engineering Center (NRDEC), Natick, Middlesex County, MA

  8. Uptake Kinetics and Trophic Transfer of Tungsten from Cabbage to a Herbivorous Animal Model

    DOE PAGES

    Lindsay, James H.; Kennedy, Alan J.; Seiter-Moser, Jennifer M.; ...

    2017-10-20

    This paper builds on previous studies on military-relevant tungsten (W) to more thoroughly explore environmental pathways and bioaccumulation kinetics during direct soil exposure versus trophic transfer and elucidate its relative accumulation and speciation in different snail organs. The modeled steady-state concentration and bioaccumulation factor (BAF) of W from soil into cabbage were 302 mg/kg and 0.55, respectively. Steady-state concentrations (34 mg/kg) and BAF values (0.05) obtained for the snail directly exposed to contaminated soil were lower than trophic transfer by consumption of W-contaminated cabbage (tissue concentration of 86 mg/kg; BAF of 0.36). Thus, consumption of contaminated food is the mostmore » important pathway for W mobility in this food chain. The highest concentrations of W compartmentalization were in the snail’s hepatopancreas based on wet chemistry and synchrotron-based investigations. Chemical speciation via inductively couple plasma mass spectrometry showed a higher degree of polytungstate partitioning in the hepatopancreas relative to the rest of the body. Based on synchrotron analysis, W was incorporated into the shell matrix during exposure, particularly during the regeneration of damaged shell. Finally, this offers the potential for application of the shell as a longer-term biomonitoring and forensics tool for historic exposure.« less

  9. Uptake Kinetics and Trophic Transfer of Tungsten from Cabbage to a Herbivorous Animal Model

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lindsay, James H.; Kennedy, Alan J.; Seiter-Moser, Jennifer M.

    This paper builds on previous studies on military-relevant tungsten (W) to more thoroughly explore environmental pathways and bioaccumulation kinetics during direct soil exposure versus trophic transfer and elucidate its relative accumulation and speciation in different snail organs. The modeled steady-state concentration and bioaccumulation factor (BAF) of W from soil into cabbage were 302 mg/kg and 0.55, respectively. Steady-state concentrations (34 mg/kg) and BAF values (0.05) obtained for the snail directly exposed to contaminated soil were lower than trophic transfer by consumption of W-contaminated cabbage (tissue concentration of 86 mg/kg; BAF of 0.36). Thus, consumption of contaminated food is the mostmore » important pathway for W mobility in this food chain. The highest concentrations of W compartmentalization were in the snail’s hepatopancreas based on wet chemistry and synchrotron-based investigations. Chemical speciation via inductively couple plasma mass spectrometry showed a higher degree of polytungstate partitioning in the hepatopancreas relative to the rest of the body. Based on synchrotron analysis, W was incorporated into the shell matrix during exposure, particularly during the regeneration of damaged shell. Finally, this offers the potential for application of the shell as a longer-term biomonitoring and forensics tool for historic exposure.« less

  10. 26. BUILDING NO. 271I, LEAD AZIDE PRIMER BUILDING, WESTERN CORNER ...

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

    26. BUILDING NO. 271-I, LEAD AZIDE PRIMER BUILDING, WESTERN CORNER OF BUILDING SHOWING DOORS TO MIXING ROOM NO. 4. HAND CRANK VISIBLE AT RIGHT ROTATED SMALL POTS (CONTAINING LEAD AZIDE) IN MIXING ROOMS. - Picatinny Arsenal, 200 Area, Shell Component Loading, State Route 15 near I-80, Dover, Morris County, NJ

  11. Ocean life breaking rules by building shells in acidic extremes.

    PubMed

    Doubleday, Zoë A; Nagelkerken, Ivan; Connell, Sean D

    2017-10-23

    Rising levels of carbon dioxide (CO 2 )from fossil fuel combustion is acidifying our oceans [1,2]. This acidification is expected to have negative effects on calcifying animals because it affects their ability to build shells [3,4]. However, the effects of ocean acidification in natural environments, subject to ecological and evolutionary processes (such as predation, competition, and adaptation), is uncertain [5,6]. These processes may buffer, or even reverse, the direct, short-term effects principally measured in laboratory experiments (for example, [6]). Here we describe the discovery of marine snails living at a shallow-water CO 2 vent in the southwest Pacific, an environment 30 times more acidic than normal seawater (Figure 1). By measuring the chemical fingerprints locked within the shell material, we show that these snails have a restricted range of movement, which suggests that they live under these conditions for their entire lives. The existence of these snails demonstrates that calcifying animals can build their shells under the acidic and corrosive conditions caused by extreme CO 2 enrichment. This unforeseen capacity, whether driven by ecological or adaptive processes, is key to understanding whether calcifying life may survive a high-CO 2 future. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. 28. Historic American Buildings Survey E. W. Russell, Photographer, May ...

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

    28. Historic American Buildings Survey E. W. Russell, Photographer, May 7, 1936 INTERIOR VIEW OF MAIN ENTRANCE TO MAIN HALL, 1st FLOOR - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

  13. 23. Historic American Buildings Survey E. W. Russell, Photographer, May ...

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

    23. Historic American Buildings Survey E. W. Russell, Photographer, May 8, 1936 EXTERIOR VIEW OF DOOR IN N. WALL (FRONT) 1st FLOOR - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

  14. 27. Historic American Buildings Survey E. W. Russell, Photographer, May ...

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

    27. Historic American Buildings Survey E. W. Russell, Photographer, May 7, 1936 EXTERIOR VIEW OF REAR DOOR TO MAIN HALLWAY, 1st FLOOR - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

  15. 19. Historic American Buildings Survey E. W. Russell, Photographer, May ...

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

    19. Historic American Buildings Survey E. W. Russell, Photographer, May 7, 1936 SOUTH ELEVATION (REAR) SHOWING ROUND IRON COLUMN AND SQUARE STUCCO COLUMN - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

  16. 26. Historic American Buildings Survey E. W. Russell, Photographer, May ...

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

    26. Historic American Buildings Survey E. W. Russell, Photographer, May 7, 1936 EXTERIOR VIEW OF WINDOW IN REAR S. WALL, 1st FLOOR - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

  17. 14. Historic American Buildings Survey E. W. Russell, Photographer, May ...

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

    14. Historic American Buildings Survey E. W. Russell, Photographer, May 8, 1936 GENERAL VIEW OF S. ELEVATION (REAR) FROM 3rd STORY REAR PORCH - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

  18. 34. Historic American Buildings Survey E. W. Russell, Photographer, May ...

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

    34. Historic American Buildings Survey E. W. Russell, Photographer, May 8, 1936 VIEW OF STAIR FROM REAR (SOUTH) OF HALL, 2nd FLOOR - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

  19. Improving the In-Medium Similarity Renormalization Group via approximate inclusion of three-body effects

    NASA Astrophysics Data System (ADS)

    Morris, Titus; Bogner, Scott

    2016-09-01

    The In-Medium Similarity Renormalization Group (IM-SRG) has been applied successfully to the ground state of closed shell finite nuclei. Recent work has extended its ability to target excited states of these closed shell systems via equation of motion methods, and also complete spectra of the whole SD shell via effective shell model interactions. A recent alternative method for solving of the IM-SRG equations, based on the Magnus expansion, not only provides a computationally feasible route to producing observables, but also allows for approximate handling of induced three-body forces. Promising results for several systems, including finite nuclei, will be presented and discussed.

  20. Path correction of free flight projectiles by cross firing of subsidiary projectiles

    NASA Astrophysics Data System (ADS)

    Stroem, L.

    1982-10-01

    Terminal guidance of gun-fired shells is described. The path is corrected by shooting out throw-bodies from the shell casing. The drawbacks of the method, e.g., casing deformation, were eliminated. Using deflagrating substances instead of explosives, higher impulses were obtained, and at lower pressure levels. At acceleration distances of only 10 to 15 mm throw-body speeds of 400 to 500 m/sec were noted, allowing this method to be applied to rotation-stabilized shells.

  1. Fabrication of precision glass shells by joining glass rods

    DOEpatents

    Gac, Frank D.; Blake, Rodger D.; Day, Delbert E.; Haggerty, John S.

    1988-01-01

    A method for making uniform spherical shells. The present invention allows niform hollow spheres to be made by first making a void in a body of material. The material is heated so that the viscosity is sufficiently low so that the surface tension will transform the void into a bubble. The bubble is allowed to rise in the body until it is spherical. The excess material is removed from around the void to form a spherical shell with a uniform outside diameter.

  2. 37. Historic American Buildings Survey E. W. Russell, Photographer, May ...

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

    37. Historic American Buildings Survey E. W. Russell, Photographer, May 7, 1936 ROTUNDA, 3rd FLOOR, SHOWING E. HALL BETWEEN ROOMS ON N. AND E. - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

  3. 2. Historic American Buildings Survey Copied by E. W. Russell, ...

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

    2. Historic American Buildings Survey Copied by E. W. Russell, Photographer, August 31, 1936 75TH ANNIVERSARY YEARBOOK (NOT COPYRIGHT) - RUINS OF OLD COLLEGE AFTER FIRE OF 1869 - Spring Hill College, Original Building, Old Shell Road, Spring Hill, Mobile County, AL

  4. 38. Historic American Buildings Survey E. W. Russell, Photographer, May ...

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

    38. Historic American Buildings Survey E. W. Russell, Photographer, May 7, 1936 N. W. SIDE OF ROTUNDA, 3rd FLOOR, SHOWING W. AND N. HALLS AND STAIR OPENING - Spring Hill College, Main Building, Old Shell Road, Spring Hill, Mobile County, AL

  5. The effect of growth rate and ageing on colour variation of European pond turtles.

    PubMed

    Ibáñez, Alejandro; Martín, José; Marzal, Alfonso; Bertolero, Albert

    2017-06-01

    Many chelonians have colourful dots, patches and stripes throughout their body that are made up, at least in part, of carotenoids. Therefore, turtles are very suitable models to study the evolution and functionality of carotenoid-based colouration. Recent studies suggested a close link between colouration and immune system in these taxa. However, more research is needed to understand the role of these colourful stripes and patches in turtle visual signalling. The purpose of this study was to explore the relationship between growth rate and colouration in European pond turtles. In particular, we wanted to answer the question of whether there is a trade-off between growth and colour expression. We also aimed to explore the effect of body size and age on colour variation. Turtles from a reintroduction-breeding program were recaptured, weighed and measured over an 8-year period to estimate their growth rates and age. We also measured with a spectrometer the reflectance of colour patches in two different body parts: shell and forelimb. We found that turtles with a faster growth rate had brighter limb stripes independently of their age. On the other hand, shell colouration was related to body size with larger turtles having brighter shell stripes and higher values of carotenoid chroma. Our results suggest that fast-growers may afford to express intense colourful limb stripes likely due to their higher intake of carotenoids that would modulate both growth and colour expression. However, shell colouration was related to body size probably due to ontogenetic differences in the diet, as juveniles are strictly carnivorous while adults are omnivorous. Alternatively, shell colouration might be involved in crypsis as the shell is visually exposed to predators.

  6. The effect of growth rate and ageing on colour variation of European pond turtles

    NASA Astrophysics Data System (ADS)

    Ibáñez, Alejandro; Martín, José; Marzal, Alfonso; Bertolero, Albert

    2017-06-01

    Many chelonians have colourful dots, patches and stripes throughout their body that are made up, at least in part, of carotenoids. Therefore, turtles are very suitable models to study the evolution and functionality of carotenoid-based colouration. Recent studies suggested a close link between colouration and immune system in these taxa. However, more research is needed to understand the role of these colourful stripes and patches in turtle visual signalling. The purpose of this study was to explore the relationship between growth rate and colouration in European pond turtles. In particular, we wanted to answer the question of whether there is a trade-off between growth and colour expression. We also aimed to explore the effect of body size and age on colour variation. Turtles from a reintroduction-breeding program were recaptured, weighed and measured over an 8-year period to estimate their growth rates and age. We also measured with a spectrometer the reflectance of colour patches in two different body parts: shell and forelimb. We found that turtles with a faster growth rate had brighter limb stripes independently of their age. On the other hand, shell colouration was related to body size with larger turtles having brighter shell stripes and higher values of carotenoid chroma. Our results suggest that fast-growers may afford to express intense colourful limb stripes likely due to their higher intake of carotenoids that would modulate both growth and colour expression. However, shell colouration was related to body size probably due to ontogenetic differences in the diet, as juveniles are strictly carnivorous while adults are omnivorous. Alternatively, shell colouration might be involved in crypsis as the shell is visually exposed to predators.

  7. Building Fossils in the Elementary School and Writing about Them Using Computers.

    ERIC Educational Resources Information Center

    Schlenker, Richard M.; Yoshida, Sarah

    This material describes a fossil-building activity using sea shells, chicken bones, and plaster for grade one through three students. Related process skills, vocabulary, computer principles, time requirements, and materials are listed. Two methods of building the fossils are discussed. After building the fossils, classes may be divided into pairs…

  8. The influence of diet on the δ 13C of shell carbon in the pulmonate snail Helix aspersa

    NASA Astrophysics Data System (ADS)

    Stott, Lowell D.

    2002-02-01

    The influence of diet and atmospheric CO 2 on the carbon isotope composition of shell aragonite and shell-bound organic carbon in the pulmonate snail Helix aspersa raised in the laboratory was investigated. Three separate groups of snails were raised on romaine lettuce (C3 plant, δ 13C=-25.8‰), corn (C4 plant, δ 13C=-10.5‰), and sour orange ( 12C-enriched C3 plant, δ 13C=-39.1‰). The isotopic composition of body tissues closely tracked the isotopic composition of the snail diet as demonstrated previously. However, the isotopic composition of the acid insoluble organic matrix extracted from the aragonite shells does not track diet in all groups. In snails that were fed corn the isotopic composition of the organic matrix was more negative than the body by as much as 5‰ whereas the matrix was approximately 1‰ heavier than the body tissues in snails fed a diet of C3 plant material. These results indicate that isotopic composition of the organic matrix carbon cannot be used as an isotopic substrate for paleodietary reconstructions without first determining the source of the carbon and any associated fractionations. The isotopic composition of the shell aragonite is offset from the body tissues by 12.3‰ in each of the culture groups. This offset was not influenced by the consumption of carbonate and is not attributable to the diffusion of atmospheric CO 2 into the hemolymph. The carbon isotopic composition of shell aragonite is best explained in terms of equilibrium fractionations associated with exchange between metabolic CO 2 and HCO 3 in the hemolymph and the fractionation associated with carbonate precipitation. These results differ from previous studies, based primarily on samples collected in the field, that have suggested atmospheric carbon dioxide contributes significantly to the shell δ 13C. The culture results indicate that the δ 13C of aragonite is a good recorder of the isotopic composition of the snail body tissue, and therefore a better recorder of diet than is the insoluble shell organic carbon. Because the systematic fractionation of carbon isotopes within the snail is temperature dependent, the δ 13C of the shell could provide an independent technique for estimating paleotemperature changes.

  9. 2 CFR 200.436 - Depreciation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... three general components of a building: building shell (including construction and design costs... from asset use. The non-Federal entity may be compensated for the use of its buildings, capital... considered as the acquisition cost. Such assets may be depreciated or claimed as matching but not both. For...

  10. 5. LOOKING NORTH TOWARD BARRICADES AROUND BUILDING NO. 230, PRIMER ...

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

    5. LOOKING NORTH TOWARD BARRICADES AROUND BUILDING NO. 230, PRIMER AND DETONATOR LOADING BUILDING. BARRICADES DIRECT FORCE OF BLAST UPWARD IN THE EVENT OF AN EXPLOSION. - Picatinny Arsenal, 200 Area, Shell Component Loading, State Route 15 near I-80, Dover, Morris County, NJ

  11. Bulge formed cooling channels with a variable lead helix on a hollow body of revolution

    NASA Technical Reports Server (NTRS)

    McAninch, Michael D. (Inventor); Holbrook, Richard L. (Inventor); Lacount, Dale F. (Inventor); Kawashige, Chester M. (Inventor); Crapuchettes, John M. (Inventor); Scala, James (Inventor)

    1993-01-01

    A method of constructing a nozzle having cooling channels comprises a shell and a liner which are formed into a body of revolution having an axis of revolution. Helical welds are formed to hold the liner and shell to each other with a channel position being defined between each pair of helical welds. Pressurized fluid which may be a gas or a liquid, is introduced between the weld pairs to outwardly bulge the material of at least one of the liner and shell to define the channels.

  12. Evaluating the Health of Your House.

    ERIC Educational Resources Information Center

    Berthold-Bond, Annie; Dadd, Debra Lynn

    1993-01-01

    Presents a framework from which individuals can evaluate the health environment in their homes. Questions are arranged to examine the general location of the house, the house's immediate surroundings and building shell, and the finishings. Provides a resource directory for air filters, building consultants, and building supplies. (MDH)

  13. Roles of NN-interaction components in shell-structure evolution

    NASA Astrophysics Data System (ADS)

    Umeya, Atsushi; Muto, Kazuo

    2016-11-01

    Since the importance of the monopole interaction was first emphasized in 1960s, roles of monopole strengths of two-body nucleon-nucleon interaction in shell structure have been discussed. Through the monopole strengths, we study the roles in shell-structure evolution, starting from explicit forms of the interaction. For the tensor component of the interaction, we show the derivation of the relation, (2j> + 1)Vjj> + (2j< + 1)Vjj< = 0, with a detailed manipulation. We show that one-body spin-orbit term appears in the multipole expansion of two-body spin-orbit interaction. Only the spin-orbit components can affect the spin-orbit energy splitting between spin-orbit partners, when the spin-orbit partner orbits are fully occupied.

  14. 30. BUILDING NO.S 271K AND 271L, VIEW LOOKING SOUTH AT ...

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

    30. BUILDING NO.S 271-K AND 271-L, VIEW LOOKING SOUTH AT BACK OF BUILDING NO. 271-L (LEFT), 271-K (MIDDLE) AND ROOF OF BUILDING NO. 271-I (VISIBLE OVER WALKWAY ON RIGHT). - Picatinny Arsenal, 200 Area, Shell Component Loading, State Route 15 near I-80, Dover, Morris County, NJ

  15. Quantified Gamow shell model interaction for p s d -shell nuclei

    NASA Astrophysics Data System (ADS)

    Jaganathen, Y.; Betan, R. M. Id; Michel, N.; Nazarewicz, W.; Płoszajczak, M.

    2017-11-01

    Background: The structure of weakly bound and unbound nuclei close to particle drip lines is one of the major science drivers of nuclear physics. A comprehensive understanding of these systems goes beyond the traditional configuration interaction approach formulated in the Hilbert space of localized states (nuclear shell model) and requires an open quantum system description. The complex-energy Gamow shell model (GSM) provides such a framework as it is capable of describing resonant and nonresonant many-body states on equal footing. Purpose: To make reliable predictions, quality input is needed that allows for the full uncertainty quantification of theoretical results. In this study, we carry out the optimization of an effective GSM (one-body and two-body) interaction in the p s d f -shell-model space. The resulting interaction is expected to describe nuclei with 5 ≤A ≲12 at the p -s d -shell interface. Method: The one-body potential of the 4He core is modeled by a Woods-Saxon + spin-orbit + Coulomb potential, and the finite-range nucleon-nucleon interaction between the valence nucleons consists of central, spin-orbit, tensor, and Coulomb terms. The GSM is used to compute key fit observables. The χ2 optimization is performed using the Gauss-Newton algorithm augmented by the singular value decomposition technique. The resulting covariance matrix enables quantification of statistical errors within the linear regression approach. Results: The optimized one-body potential reproduces nucleon-4He scattering phase shifts up to an excitation energy of 20 MeV. The two-body interaction built on top of the optimized one-body field is adjusted to the bound and unbound ground-state binding energies and selected excited states of the helium, lithium, and beryllium isotopes up to A =9 . A very good agreement with experimental results was obtained for binding energies. First applications of the optimized interaction include predictions for two-nucleon correlation densities and excitation spectra of light nuclei with quantified uncertainties. Conclusion: The new interaction will enable comprehensive and fully quantified studies of structure and reactions aspects of nuclei from the p s d region of the nuclear chart.

  16. Quantified Gamow shell model interaction for p s d -shell nuclei

    DOE PAGES

    Jaganathen, Y.; Betan, R. M. Id; Michel, N.; ...

    2017-11-20

    Background: The structure of weakly bound and unbound nuclei close to particle drip lines is one of the major science drivers of nuclear physics. A comprehensive understanding of these systems goes beyond the traditional configuration interaction approach formulated in the Hilbert space of localized states (nuclear shell model) and requires an open quantum system description. The complex-energy Gamow shell model (GSM) provides such a framework as it is capable of describing resonant and nonresonant many-body states on equal footing. Purpose: To make reliable predictions, quality input is needed that allows for the full uncertainty quantification of theoretical results. In thismore » study, we carry out the optimization of an effective GSM (one-body and two-body) interaction in the psdf-shell-model space. The resulting interaction is expected to describe nuclei with 5 ≤ A ≲ 12 at the p-sd-shell interface. Method: The one-body potential of the 4He core is modeled by a Woods-Saxon + spin-orbit + Coulomb potential, and the finite-range nucleon-nucleon interaction between the valence nucleons consists of central, spin-orbit, tensor, and Coulomb terms. The GSM is used to compute key fit observables. The χ 2 optimization is performed using the Gauss-Newton algorithm augmented by the singular value decomposition technique. The resulting covariance matrix enables quantification of statistical errors within the linear regression approach. Results: The optimized one-body potential reproduces nucleon- 4He scattering phase shifts up to an excitation energy of 20 MeV. The two-body interaction built on top of the optimized one-body field is adjusted to the bound and unbound ground-state binding energies and selected excited states of the helium, lithium, and beryllium isotopes up to A = 9 . A very good agreement with experimental results was obtained for binding energies. First applications of the optimized interaction include predictions for two-nucleon correlation densities and excitation spectra of light nuclei with quantified uncertainties. In conclusion: The new interaction will enable comprehensive and fully quantified studies of structure and reactions aspects of nuclei from the psd region of the nuclear chart.« less

  17. Core excitations across the neutron shell gap in 207Tl

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wilson, E.; Podolyák, Zs.; Grawe, H.

    2015-05-05

    The single closed-neutron-shell, one proton–hole nucleus 207Tl was populated in deep-inelastic collisions of a 208Pb beam with a 208Pb target. The yrast and near-yrast level scheme has been established up to high excitation energy, comprising an octupole phonon state and a large number of core excited states. Based on shell-model calculations, all observed single core excitations were established to arise from the breaking of the N=126 neutron core. While the shell-model calculations correctly predict the ordering of these states, their energies are compressed at high spins. It is concluded that this compression is an intrinsic feature of shell-model calculations usingmore » two-body matrix elements developed for the description of two-body states, and that multiple core excitations need to be considered in order to accurately calculate the energy spacings of the predominantly three-quasiparticle states.« less

  18. Ab initio many-body perturbation theory and no-core shell model

    NASA Astrophysics Data System (ADS)

    Hu, B. S.; Wu, Q.; Xu, F. R.

    2017-10-01

    In many-body perturbation theory (MBPT) we always introduce a parameter N shell to measure the maximal allowed major harmonic-oscillator (HO) shells for the single-particle basis, while the no-core shell model (NCSM) uses N maxℏΩ HO excitation truncation above the lowest HO configuration for the many-body basis. It is worth comparing the two different methods. Starting from “bare” and Okubo-Lee-Suzuki renormalized modern nucleon-nucleon interactions, NNLOopt and JISP16, we show that MBPT within Hartree-Fock bases is in reasonable agreement with NCSM within harmonic oscillator bases for 4He and 16O in “close” model space. In addition, we compare the results using “bare” force with the Okubo-Lee-Suzuki renormalized force. Supported by National Key Basic Research Program of China (2013CB834402), National Natural Science Foundation of China (11235001, 11320101004, 11575007) and the CUSTIPEN (China-U.S. Theory Institute for Physics with Exotic Nuclei) funded by the U.S. Department of Energy, Office of Science (DE-SC0009971)

  19. 1. VIEW SOUTHWEST FROM CORNER OF EAST MAIN AND SHELL ...

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

    1. VIEW SOUTHWEST FROM CORNER OF EAST MAIN AND SHELL STREETS, LOOKING TOWARD BUILDINGS BEHIND WHICH M/V 'FOX' LIES. SEE FIGURE 4 ON PAGE 6 OF DATA PAGES FOR MAP. - Motorized Sailing Vessel "Fox", Beached on East Bank ofBayou Lafourche, Larose, Lafourche Parish, LA

  20. Improving the In-Medium Similarity Renormalization Group via approximate inclusion of three-body effects

    NASA Astrophysics Data System (ADS)

    Morris, Titus; Bogner, Scott

    2015-10-01

    The In-Medium Similarity Renormalization Group (IM-SRG) has been applied successfully not only to several closed shell finite nuclei, but has recently been used to produce effective shell model interactions that are competitive with phenomenological interactions in the SD shell. A recent alternative method for solving of the IM-SRG equations, called the Magnus expansion, not only provides a computationally feasible route to producing observables, but also allows for approximate handling of induced three-body forces. Promising results for several systems, including finite nuclei, will be presented and discussed.

  1. Repeated crossing of two concentric spherical thin-shells with charge

    NASA Astrophysics Data System (ADS)

    Mazharimousavi, S. Habib; Halilsoy, M.

    Interaction/collision of two concentric spherical thin-shells of linear fluid resulting in collapse has been considered recently. We show that addition of finely tuned electric charges on the shells apart from the cosmological constant serves to delay the collapse indefinitely, yielding an ever colliding system of two concentric fluid shells. Given the finely tuned charges, this provides an example of a perpetual two-body motion in general relativity.

  2. Simulation Analysis of Temperature Field in the Heat Transfer Process of Shell

    NASA Astrophysics Data System (ADS)

    Zhang, Di; Luo, Zhen; Xuan, Wenbo

    Sea temperature is the key factors that determines whether shellfish can maintain normal growth development and survival, as protective film, the shell is a very important part of structure of shellfish, so the research of heat transfer characteristics become very important. In this paper, we firstly make a comprehensive analysis on the appearance of the shell, for the next simulation builds a good foundation, and based on the large general finite element analysis software ANSYS, we analyze the thermodynamics of shells, study the effect of the shell thickness and structure on heat transfer time. And through apply different temperature load, analyze the heat transfer characteristics and temperature distribution of the shells, It is expected that the results is useful at the biological heat transfer of shellfish.

  3. About mechanisms of tetonic activity of the satellites

    NASA Astrophysics Data System (ADS)

    Barkin, Yu. V.

    2003-04-01

    ABOUT MECHANISMS OF TECTONIC ACTIVITY OF THE SATELLITES Yu.V. Barkin Sternberg Astronomical Institute, Moscow, Russia, barkin@sai.msu.ru Due to attraction of the central planet and others external bodies satellite is subjected by tidal and non-tidal deformations. Elastic energy is changed in dependence from mutual position and motion of celestial bodies and as result the tensional state of satellite and its tectonic (endogenous) activity also is changed. Satellites of the planets have the definite shell’s structure and due to own rotation these shells are characterized by different oblatenesses. Gravitational interaction of the satellite and its mother planet generates big additional mechanical forces (and moments) between the neighboring non-spherical shells of the satellite (mantle, core and crust). These forces and moments are cyclic functions of time, which are changed in the different time-scales. They generate corresponding cyclic perturbations of the tensional state of the shells, their deformations, small relative transnational displacements and slow rotation of the shells and others. In geological period of time it leads to a fundamental tectonic reconstruction of the body. Definite contribution to discussed phenomena are caused by classical tidal mechanism. of planet-satellite interaction. But in this report we discuss in first the new mechanisms of endogenous activity of celestial bodies. They are connected with differential gravitational attraction of non-spherical satellite shells by the external celestial bodies which leads: 1) to small relative rotation (nutations) of the shells; 2) to small relative translational motions of the shells (displacements of their center of mass); 3) to relative displacements and rotations of the shells due to eccentricity of their center of mass positions; 4) to viscous elastic deformations of the shells and oth. (Barkin, 2001). For higher evaluations of the power of satellite endogenous activities were obtained analytical formulae. Obtained theoretical evaluations of the force and power characteristics are in good agreement with observational date and in particular they explain some from the well known problems of planetology. The following phenomena obtain an explanation: 1. Higher endogenous activity of Io; 2. Europe crack systems; 3. high endogenous activity of Ganimede, Titan, Miranda, Enceladus, Ariel. Well known relations of tectonic activity between satellites: Ariel and Umbriel, Reiha and Diona, Titania and Oberon have been explained in terms of numerical values of force and energy characteristics. Conclusion about high endogenous activity of Titan also presents important interest. The work was accepted and financed by RFBR grant N 02-05-64176 and by grant SAB2000-0235 of Ministry of Education of Spain (Secretaria de Estado de Educacion y Universidades).

  4. High pressure electrical insulated feed thru connector

    DOEpatents

    Oeschger, Joseph E.; Berkeland, James E.

    1979-11-13

    A feed-thru type hermetic electrical connector including at least one connector pin feeding through an insulator block within the metallic body of the connector shell. A compression stop arrangement coaxially disposed about the insulator body is brazed to the shell, and the shoulder on the insulator block bears against this top in a compression mode, the high pressure or internal connector being at the opposite end of the shell. Seals between the pin and an internal bore at the high pressure end of the insulator block and between the insulator block and the metallic shell at the high pressure end are hermetically brazed in place, the first of these also functioning to transfer the axial compressive load without permitting appreciable shear action between the pin and insulator block.

  5. Full f-p Shell Calculation of {sup 51}Ca and {sup 51}Sc

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Novoselsky, A.; Vallieres, M.; Laadan, O.

    The spectra and the electromagnetic transitions of the nuclei {sup 51}Ca and {sup 51}Sc with 11 nucleons in the {ital f-p} shell are described in the nuclear shell-model approach by using two different two-body effective interactions. The full {ital f-p} shell basis functions are used with no truncation. The new parallel shell-model computer code DUPSM (Drexel University parallel shell model), that we recently developed, has been used. The calculations have been done on the MOSIX parallel machine at the Hebrew University of Jerusalem. {copyright} {ital 1997} {ital The American Physical Society}

  6. The limits of hamiltonian structures in three-dimensional elasticity, shells, and rods

    NASA Astrophysics Data System (ADS)

    Ge, Z.; Kruse, H. P.; Marsden, J. E.

    1996-01-01

    This paper uses Hamiltonian structures to study the problem of the limit of three-dimensional (3D) elastic models to shell and rod models. In the case of shells, we show that the Hamiltonian structure for a three-dimensional elastic body converges, in a sense made precise, to that for a shell model described by a one-director Cosserat surface as the thickness goes to zero. We study limiting procedures that give rise to unconstrained as well as constrained Cosserat director models. The case of a rod is also considered and similar convergence results are established, with the limiting model being a geometrically exact director rod model (in the framework developed by Antman, Simo, and coworkers). The resulting model may or may not have constraints, depending on the nature of the constitutive relations and their behavior under the limiting procedure. The closeness of Hamiltonian structures is measured by the closeness of Poisson brackets on certain classes of functions, as well as the Hamiltonians. This provides one way of justifying the dynamic one-director model for shells. Another way of stating the convergence result is that there is an almost-Poisson embedding from the phase space of the shell to the phase space of the 3D elastic body, which implies that, in the sense of Hamiltonian structures, the dynamics of the elastic body is close to that of the shell. The constitutive equations of the 3D model and their behavior as the thickness tends to zero dictates whether the limiting 2D model is a constrained or an unconstrained director model. We apply our theory in the specific case of a 3D Saint Venant-Kirchhoff material and derive the corresponding limiting shell and rod theories. The limiting shell model is an interesting Kirchhoff-like shell model in which the stored energy function is explicitly derived in terms of the shell curvature. For rods, one gets (with an additional inextensibility constraint) a one-director Kirchhoff elastic rod model, which reduces to the well-known Euler elastica if one adds an additional single constraint that the director lines up with the Frenet frame.

  7. A concept of technology for freight wagons modernization

    NASA Astrophysics Data System (ADS)

    Pɫaczek, M.; Wróbel, A.; Buchacz, A.

    2016-11-01

    Rail transport is a very important part of the modern economy, one of the components determining its dynamic development. It is therefore important to conduct research and taking action aimed at the development and refinement of this branch of industry. Such actions directly translate into an increase in its effectiveness, safety, reduction of burden on the environment and society. Nowadays numerous studies are conducted, aimed at introducing new technologies and solutions, both in terms of railway infrastructure and logistics management systems, as well as in traction vehicles themselves. Introduction of modern technology helps eliminate or reduce nuisance problems associated with the implementation of any kind of transport or the operation of the used technical means. Presented paper concerns an issue of freight wagon modernization using composite materials. It presents a part of a research project that aim is to develop a technology of freight wagons modernization during their periodic repair. The main problem during exploitation of concerned types of freight wagons designed for coal transport is corrosion of the wagon's body shell. The goal of the project is to elongate the period between periodic repairs (by better corrosion protection) and improve conditions of exploitation of modernized freight wagons (for example easier unloading during winter conditions - no freezes of the charge to the freight wagon body shell). One of elements of the project is also to develop a system for diagnosing the technical condition of the modernized shell of wagon body during operation. For this purpose the use of non-destructive testing methods of technical state of constructions will be used, including methods that use the analysis of dynamic response of the object. Application of the composite panels to the freight wagon's body shell was proposed as the solution that can solve mentioned problems during exploitation of freight wagons. The composite panels composed of fiberglass and epoxy resin were proposed. They will be mounted on the body shell using blind rivet nuts. What is more the body shell of the modernized freight wagon will be painted using an anticorrosion agent. The research project is realized by a consortium composed by research units and industry and supported by the Polish National Centre for Research and Development.

  8. Gravitational mechanism of active life of the Earth, planets and satellites

    NASA Astrophysics Data System (ADS)

    Barkin, Yury

    2010-05-01

    From positions of geodynamic model of the forced gravitational swing, wobble and displacements of shells of a planet are studied and fundamental problems of geodynamics, geology, geophysics, planetary sciences are solved etc.: 1) The mechanism of cyclic variations of activity of natural processes in various time scales. 2) The power of endogenous activity of planetary natural processes on planets and satellites. 3) The phenomenon of polar inversion of natural processes on planets and satellites. 4) Spasmodic and catastrophic changes of activity of natural processes. 5) The phenomenon of twisting of hemispheres (latitude zones or belts) of celestial bodies. 6) Formation of the pear-shaped form of celestial bodies and the mechanism of its change. 7) The ordered planetary structures of geological formations. 8) The phenomena of bipolarity of celestial bodies and antipodality of geology formations. Mechanism. The fundamental feature of a structure of celestial bodies is their shell structure. The most investigated is the internal structure of the Earth. For the Moon and wide set of other bodies of solar system models of an internal structure have been constructed on the basis of the data of observations obtained at studying of their gravitational fields as a result of realization of the appropriate space missions. The basic components for the majority of celestial bodies are the core, the mantle and the crust. To other shells we concern atmospheres (for example, at Venus, Mars, the Titan etc.) and oceanic shells (the Titan, the Earth, Enceladus etc.). Shells are the complex (composite) formations. Planets and satellites are not spherical celestial bodies. The centers of mass of shells of the given planet (or the satellite) and their appropriate principal axes of inertia do not coincide. Accordingly, all their shells are characterized by the certain dynamic oblatenesses. Differences of dynamical oblatenesses results in various forced influences of external celestial bodies on shells of the given body. Dynamical oblatenesses of shells, thus, characterize the endogenous activity of a planet by external celestial bodies. Other important factor of endogenous activity of a planet is a eccentric position of the centers of mass of the shells (for example, of the core and the mantle). The eccentricity of the shells is inherited during geological evolution of a planet as system of shells (Barkin, 2002). Consequences of exitation of the Earth system. The new tides (Barkin, 2005) are caused by relative displacements of the core and mantle. These displacements are reflected in variations of many natural processes due to gravitational action of the core. The displacing core causes deformations of all layers of viscous-elastic mantle. In the given work from more general positions the mechanisms of excitation of a system of shells of the Earth under action of a gravitational attraction of the Sun, the Moon and planets, the phenomena of their relative swings, translational displacements and turns relatively from each other, and the wide list geodynamical consequences of the specified excitation of the Earth are studied. At once we shall emphasize, that the developed geodynamic model has allowed to carry out the important dynamic researches of displacements of shells of the Earth, their deformations and changes, and variations of its natural processes and for the first time to explain the nature of such fundamental phenomena and processes in geodynamics, geology and geophysics as: cyclicity of natural processes and its mechanism; power of processes in various time scales; unity of cyclic processes and universality of their frequency bases; synchronism of geodynamic, geophysical, biophysical and social events; inversion, contrast and opposite directed changes of activity of natural processes in opposite hemispheres of the Earth; step-by-step variations of natural processes, sawtooth course of activity of natural processes in various time scales; orderliness in an distribution of geological formations on the Earth, planets and satellites; existence of antipodal formations on planets and satellites; the phenomenon of twisting of hemispheres of bodies of solar system, twisting of layers and latitudinal zones of shells of celestial bodies including inner layers and shells, etc. All the specified phenomena from the resulted list to some extent are discussed in the given work and illustrated on the basis of modern researches in Earth's sciences and the researches executed by means of space missions. In a complex, the executed researches have shown universality of discussed mechanisms and their important role in dynamics and geoevolution of planets and satellites in other planetary systems, and also stars and pulsars with the systems of planets (Barkin, 2009). Cyclicity. The excitation on the part of external celestial bodies of the system core-mantle depends from relative positions of external celestial bodies, from particularities of their perturbed orbital motions and from rotary motion of the planet. The specified motions have a cyclic nature which is shown in various time scales. Hence, and excitation of shells and their layers will have also cyclic character and to be shown in various time scales. Hence, cyclic variations of all planetary natural processes in all the variety widely should be observed, as takes place in reality. The periods of variations are characterized by extremely wide range - from hours up to tens and hundreds millions years. If the core makes slow secular drift relatively to the mantle all layers and shells of the Earth test secular deformation, thermodynamic and other changes. The cavity of the core and its flows are changed slowly that results in secular variations of a magnetic field (Barkin, 2002, 2009). Inversion and asymmetry of cyclic and secular variations of natural processes. The essence of it rather wide distributed phenomena is, that activity of natural processes varies in an antiphase in opposite hemispheres of the Earth (first of all in northern and southern hemispheres). Told concerns to all geodynamic and geophysical processes, to variations of physical fields, to tectonic and geodetic reorganizations of layers of the Earth, to redistributions of atmospheric, oceanic and other fluid masses of the Earth. The certain asymmetry of displays of processes in northern and southern hemispheres on the other hand is marked. So secular trends of some processes are contrast in northern and southern hemispheres, i.e. velocities of secular changes are essentially different. All described phenomena are caused first of all by cyclic oscillations and secular drift of the core to the north (in present epoch). In longer time scales the similar phenomena of inversion, dissymmetry also have place and determine a nature and style of displacements of continents and lithospheric plates, planetary magmatic activity and plume tectonics as a whole, formation of mountains, elevations and depressions, systems of lineaments and cracks, regressions and transgressions of sea level (Barkin, 2002). Synchronous steps of activity of natural processes. 'For an explanation of observably step-by-step variations of geodynamic and geophysical processes the mechanism of sharp sporadic relative displacements of the core and the mantle and deformations of the mantle in the certain periods of time (the phenomenon of "galloping of the core') is offered.

  9. Building Strong Literacy Foundations, Birth to Three Years

    ERIC Educational Resources Information Center

    Makin, Laurie

    2005-01-01

    SHELLS (Support at Home for Early Language and LiteracieS) is a program designed for families with children from birth to three years of age. It has operated in Australia since 1998. Partnerships are at the heart of SHELLS. Parents know their children, their community, and what is culturally appropriate. Facilitators know the community, have…

  10. ControlShell - A real-time software framework

    NASA Technical Reports Server (NTRS)

    Schneider, Stanley A.; Ullman, Marc A.; Chen, Vincent W.

    1991-01-01

    ControlShell is designed to enable modular design and impplementation of real-time software. It is an object-oriented tool-set for real-time software system programming. It provides a series of execution and data interchange mechansims that form a framework for building real-time applications. These mechanisms allow a component-based approach to real-time software generation and mangement. By defining a set of interface specifications for intermodule interaction, ControlShell provides a common platform that is the basis for real-time code development and exchange.

  11. Shape-assisted body reorientation enhances trafficability through cluttered terrain

    NASA Astrophysics Data System (ADS)

    Li, Chen; Pullin, Andrew; Haldane, Duncan; Fearing, Ronald; Full, Robert

    2014-11-01

    Many birds and fishes have slender, streamlined bodies that reduce fluid dynamic drag and allow fast and efficient locomotion. Similarly, numerous terrestrial animals run through cluttered terrain where 3-D, multi-component obstacles like grass, bushes, trees, walls, doors, and pillars also resist motion, but it is unknown whether their body shape plays a major role. Here, we challenged discoid cockroaches that possess a rounded, thin, nearly ellipsoidal body to run through tall, narrowly spaced, grass-like beams. The animals primarily rolled their body to the side to maneuver through the obstacle gaps. Reduction of body roundness by artificial shells inhibited this side roll maneuver, resulting in a lower traversal probability and a longer traversal time (P < 0.001, ANOVA). Inspired by this discovery, we added a cockroach-like, rounded exoskeleton shell to a legged robot of a nearly cuboidal body. The rounded shell enabled the robot to use passive side rolling to maneuver through beams. To explain the mechanism, we developed a simple physics model to construct an energy landscape of the body-terrain interaction, which allowed estimation of body forces and torques exerted by the beams. Our model revealed that, by passive interaction with the terrain, a rounded body (ellipsoid) rolled more easily than an angular body (cuboid) to access energy valleys between energy barriers caused by obstacles. Our study is the first to demonstrate that a terradynamically ``streamlined'' shape can reduce terrain resistance and enhance trafficability by assisting body reorientation.

  12. Atypicality of Most Few-Body Observables

    NASA Astrophysics Data System (ADS)

    Hamazaki, Ryusuke; Ueda, Masahito

    2018-02-01

    The eigenstate thermalization hypothesis (ETH), which dictates that all diagonal matrix elements within a small energy shell be almost equal, is a major candidate to explain thermalization in isolated quantum systems. According to the typicality argument, the maximum variations of such matrix elements should decrease exponentially with increasing the size of the system, which implies the ETH. We show, however, that the typicality argument does not apply to most few-body observables for few-body Hamiltonians when the width of the energy shell decreases at most polynomially with increasing the size of the system.

  13. Hierarchically Enhanced Impact Resistance of Bioinspired Composites.

    PubMed

    Gu, Grace X; Takaffoli, Mahdi; Buehler, Markus J

    2017-07-01

    An order of magnitude tougher than nacre, conch shells are known for being one of the toughest body armors in nature. However, the complexity of the conch shell architecture creates a barrier to emulating its cross-lamellar structure in synthetic materials. Here, a 3D biomimetic conch shell prototype is presented, which can replicate the crack arresting mechanisms embedded in the natural architecture. Through an integrated approach combining simulation, additive manufacturing, and drop tower testing, the function of hierarchy in conch shell's multiscale microarchitectures is explicated. The results show that adding the second level of cross-lamellar hierarchy can boost impact performance by 70% and 85% compared to a single-level hierarchy and the stiff constituent, respectively. The overarching mechanism responsible for the impact resistance of conch shell is the generation of pathways for crack deviation, which can be generalized to the design of future protective apparatus such as helmets and body armor. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Composite shell spacecraft seat

    NASA Technical Reports Server (NTRS)

    Barackman, Victor J. (Inventor); Pulley, John K. (Inventor); Simon, Xavier D. (Inventor); McKee, Sandra D. (Inventor)

    2008-01-01

    A two-part seat (10) providing full body support that is specific for each crew member (30) on an individual basis. The two-part construction for the seat (10) can accommodate many sizes and shapes for crewmembers (30) because it is reconfigurable and therefore reusable for subsequent flights. The first component of the two-part seat construction is a composite shell (12) that surrounds the crewmember's entire body and is generically fitted to their general size in height and weight. The second component of the two-part seat (10) is a cushion (20) that conforms exactly to the specific crewmember's entire body and gives total body support in more complex environment.

  15. Ultra-large supramolecular coordination cages composed of endohedral Archimedean and Platonic bodies

    NASA Astrophysics Data System (ADS)

    Byrne, Kevin; Zubair, Muhammad; Zhu, Nianyong; Zhou, Xiao-Ping; Fox, Daniel S.; Zhang, Hongzhou; Twamley, Brendan; Lennox, Matthew J.; Düren, Tina; Schmitt, Wolfgang

    2017-05-01

    Pioneered by Lehn, Cram, Peterson and Breslow, supramolecular chemistry concepts have evolved providing fundamental knowledge of the relationships between the structures and reactivities of organized molecules. A particular fascinating class of metallo-supramolecular molecules are hollow coordination cages that provide cavities of molecular dimensions promoting applications in diverse areas including catalysis, enzyme mimetics and material science. Here we report the synthesis of coordination cages with exceptional cross-sectional diameters that are composed of multiple sub-cages providing numerous distinctive binding sites through labile coordination solvent molecules. The building principles, involving Archimedean and Platonic bodies, renders these supramolecular keplerates as a class of cages whose composition and topological aspects compare to characteristics of edge-transitive {Cu2} MOFs with A3X4 stoichiometry. The nature of the cavities in these double-shell metal-organic polyhedra and their inner/outer binding sites provide perspectives for post-synthetic functionalizations, separations and catalysis. Transmission electron microscopy studies demonstrate that single molecules are experimentally accessible.

  16. Ultra-large supramolecular coordination cages composed of endohedral Archimedean and Platonic bodies

    PubMed Central

    Byrne, Kevin; Zubair, Muhammad; Zhu, Nianyong; Zhou, Xiao-Ping; Fox, Daniel S.; Zhang, Hongzhou; Twamley, Brendan; Lennox, Matthew J.; Düren, Tina; Schmitt, Wolfgang

    2017-01-01

    Pioneered by Lehn, Cram, Peterson and Breslow, supramolecular chemistry concepts have evolved providing fundamental knowledge of the relationships between the structures and reactivities of organized molecules. A particular fascinating class of metallo-supramolecular molecules are hollow coordination cages that provide cavities of molecular dimensions promoting applications in diverse areas including catalysis, enzyme mimetics and material science. Here we report the synthesis of coordination cages with exceptional cross-sectional diameters that are composed of multiple sub-cages providing numerous distinctive binding sites through labile coordination solvent molecules. The building principles, involving Archimedean and Platonic bodies, renders these supramolecular keplerates as a class of cages whose composition and topological aspects compare to characteristics of edge-transitive {Cu2} MOFs with A3X4 stoichiometry. The nature of the cavities in these double-shell metal-organic polyhedra and their inner/outer binding sites provide perspectives for post-synthetic functionalizations, separations and catalysis. Transmission electron microscopy studies demonstrate that single molecules are experimentally accessible. PMID:28485392

  17. Core-Shell Particles as Building Blocks for Systems with High Duality Symmetry

    NASA Astrophysics Data System (ADS)

    Rahimzadegan, Aso; Rockstuhl, Carsten; Fernandez-Corbaton, Ivan

    2018-05-01

    Material electromagnetic duality symmetry requires a system to have equal electric and magnetic responses. Intrinsically dual materials that meet the duality conditions at the level of the constitutive relations do not exist in many frequency bands. Nevertheless, discrete objects like metallic helices and homogeneous dielectric spheres can be engineered to approximate the dual behavior. We exploit the extra degrees of freedom of a core-shell dielectric sphere in a particle optimization procedure. The duality symmetry of the resulting particle is more than 1 order of magnitude better than previously reported nonmagnetic objects. We use T -matrix-based multiscattering techniques to show that the improvement is transferred onto the duality symmetry of composite objects when the core-shell particle is used as a building block instead of homogeneous spheres. These results are relevant for the fashioning of systems with high duality symmetry, which are required for some technologically important effects.

  18. Alignment and Distortion-Free Integration of Lightweight Mirrors into Meta-Shells for High-Resolution Astronomical X-Ray Optics

    NASA Technical Reports Server (NTRS)

    Chan, Kai-Wing; Zhang, William W.; Schofield, Mark J.; Numata, Ai; Mazzarella, James R.; Saha, Timo T.; Biskach, Michael P.; McCelland, Ryan S.; Niemeyer, Jason; Sharpe, Marton V.; hide

    2016-01-01

    High-resolution, high throughput optics for x-ray astronomy requires fabrication of well-formed mirror segments and their integration with arc-second level precision. Recently, advances of fabrication of silicon mirrors developed at NASA/Goddard prompted us to develop a new method of mirror integration. The new integration scheme takes advantage of the stiffer, more thermally conductive, and lower-CTE silicon, compared to glass, to build a telescope of much lighter weight. In this paper, we address issues of aligning and bonding mirrors with this method. In this preliminary work, we demonstrated the basic viability of such scheme. Using glass mirrors, we demonstrated that alignment error of 1" and bonding error 2" can be achieved for mirrors in a single shell. We will address the immediate plan to demonstrate the bonding reliability and to develop technology to build up a mirror stack and a whole "meta-shell".

  19. Does Your Facility Promote Educational Success?

    ERIC Educational Resources Information Center

    McGovern, Matthew

    2000-01-01

    Explains that schools must be maintained to ensure children have a good environment in which to learn and explores the following three components affecting a learning environment: site improvements; building shell; and interior spaces and systems. A building assessment form is included. (GR)

  20. Terradynamically streamlined shapes in animals and robots enhance traversability through densely cluttered terrain.

    PubMed

    Li, Chen; Pullin, Andrew O; Haldane, Duncan W; Lam, Han K; Fearing, Ronald S; Full, Robert J

    2015-06-22

    Many animals, modern aircraft, and underwater vehicles use fusiform, streamlined body shapes that reduce fluid dynamic drag to achieve fast and effective locomotion in air and water. Similarly, numerous small terrestrial animals move through cluttered terrain where three-dimensional, multi-component obstacles like grass, shrubs, vines, and leaf litter also resist motion, but it is unknown whether their body shape plays a major role in traversal. Few ground vehicles or terrestrial robots have used body shape to more effectively traverse environments such as cluttered terrain. Here, we challenged forest-floor-dwelling discoid cockroaches (Blaberus discoidalis) possessing a thin, rounded body to traverse tall, narrowly spaced, vertical, grass-like compliant beams. Animals displayed high traversal performance (79 ± 12% probability and 3.4 ± 0.7 s time). Although we observed diverse obstacle traversal strategies, cockroaches primarily (48 ± 9% probability) used a novel roll maneuver, a form of natural parkour, allowing them to rapidly traverse obstacle gaps narrower than half their body width (2.0 ± 0.5 s traversal time). Reduction of body roundness by addition of artificial shells nearly inhibited roll maneuvers and decreased traversal performance. Inspired by this discovery, we added a thin, rounded exoskeletal shell to a legged robot with a nearly cuboidal body, common to many existing terrestrial robots. Without adding sensory feedback or changing the open-loop control, the rounded shell enabled the robot to traverse beam obstacles with gaps narrower than shell width via body roll. Such terradynamically 'streamlined' shapes can reduce terrain resistance and enhance traversability by assisting effective body reorientation via distributed mechanical feedback. Our findings highlight the need to consider body shape to improve robot mobility in real-world terrain often filled with clutter, and to develop better locomotor-ground contact models to understand interaction with 3D, multi-component terrain.

  1. 86. ARAIII. GCRE reactor building (ARA608) showing mechanical loop pit ...

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

    86. ARA-III. GCRE reactor building (ARA-608) showing mechanical loop pit after building shell had been erected. Beyond pit are demineralized water surge tank and heat exchanger. Camera facing northeast. December 22, 1958. Ineel photo no. 58-6427. Photographer: Ken Mansfield. - Idaho National Engineering Laboratory, Army Reactors Experimental Area, Scoville, Butte County, ID

  2. 17. Perimeter acquisition radar building room #105, mechanical equipment room ...

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

    17. Perimeter acquisition radar building room #105, mechanical equipment room no. 1; sign reads: Heat exchangers (shell and tube type). Provide precise temperature control of water for cooling critical electronic equipment - Stanley R. Mickelsen Safeguard Complex, Perimeter Acquisition Radar Building, Limited Access Area, between Limited Access Patrol Road & Service Road A, Nekoma, Cavalier County, ND

  3. Biomineral repair of abalone shell apertures.

    PubMed

    Cusack, Maggie; Guo, Dujiao; Chung, Peter; Kamenos, Nicholas A

    2013-08-01

    The shell of the gastropod mollusc, abalone, is comprised of nacre with an outer prismatic layer that is composed of either calcite or aragonite or both, depending on the species. A striking characteristic of the abalone shell is the row of apertures along the dorsal margin. As the organism and shell grow, new apertures are formed and the preceding ones are filled in. Detailed investigations, using electron backscatter diffraction, of the infill in three species of abalone: Haliotis asinina, Haliotis gigantea and Haliotis rufescens reveals that, like the shell, the infill is composed mainly of nacre with an outer prismatic layer. The infill prismatic layer has identical mineralogy as the original shell prismatic layer. In H. asinina and H. gigantea, the prismatic layer of the shell and infill are made of aragonite while in H. rufescens both are composed of calcite. Abalone builds the infill material with the same high level of biological control, replicating the structure, mineralogy and crystallographic orientation as for the shell. The infill of abalone apertures presents us with insight into what is, effectively, shell repair. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Specialized morphology corresponds to a generalist diet: linking form and function in smashing mantis shrimp crustaceans.

    PubMed

    deVries, Maya S; Stock, Brian C; Christy, John H; Goldsmith, Gregory R; Dawson, Todd E

    2016-10-01

    Many animals are considered to be specialists because they have feeding structures that are fine-tuned for consuming specific prey. For example, "smasher" mantis shrimp have highly specialized predatory appendages that generate forceful strikes to break apart hard-shelled prey. Anecdotal observations suggest, however, that the diet of smashers may include soft-bodied prey as well. Our goal was to examine the diet breadth of the smasher mantis shrimp, Neogonodactylus bredini, to determine whether it has a narrow diet of hard-shelled prey. We combined studies of prey abundance, feeding behavior, and stable isotope analyses of diet in both seagrass and coral rubble to determine if N. bredini's diet was consistent across different habitat types. The abundances of hard-shelled and soft-bodied prey varied between habitats. In feeding experiments, N. bredini consumed both prey types. N. bredini consumed a range of different prey in the field as well and, unexpectedly, the stable isotope analysis demonstrated that soft-bodied prey comprised a large proportion (29-53 %) of the diet in both habitats. Using a Bayesian mixing model framework (MixSIAR), we found that this result held even when we used uninformative, or generalist, priors and informative priors reflecting a specialist diet on hard-shelled prey and prey abundances in the field. Thus, contrary to expectation, the specialized feeding morphology of N. bredini corresponds to a broad diet of both hard-shelled and soft-bodied prey. Using multiple lines of study to describe the natural diets of other presumed specialists may demonstrate that specialized morphology often broadens rather than narrows diet breadth.

  5. Charge symmetry breaking in light Λ hypernuclei

    NASA Astrophysics Data System (ADS)

    Gal, Avraham; Gazda, Daniel

    2018-02-01

    Charge symmetry breaking (CSB) is particularly strong in the A = 4 mirror hypernuclei {}14\\text{H}-Λ 4\\text{He}. Recent four-body no-core shell model calculations that confront this CSB by introducing Λ-Σ0 mixing to leading-order chiral effective field theory hyperon-nucleon potentials are reviewed, and a shell-model approach to CSB in p-shell Λ hypernuclei is outlined.

  6. The Strength of Shell Bodies : Theory and Practice

    NASA Technical Reports Server (NTRS)

    Ebner, H

    1937-01-01

    The monocoque form of airplane construction has introduced a number of new problems to the stress calculator and the designer. The problems for the stress calculator fall into two groups: the determination of the stress condition (shell statics) and the determination of the failing strength (shell strength). The present report summarizes the most important theoretical and experimental results on this subject.

  7. Swimming of a Sea Butterfly with an Elongated Shell

    NASA Astrophysics Data System (ADS)

    Karakas, Ferhat; Maas, Amy E.; Murphy, David W.

    2017-11-01

    Sea butterflies (pteropods) are small, zooplanktonic marine snails which swim by flapping highly flexible parapodia. Previous studies show that the swimming hydrodynamics of Limacina helicina, a polar pteropod with a spiraled shell, is similar to tiny insect flight aerodynamics and that forward-backward pitching is key for lift generation. However, swimming by diverse pteropod species with different shell shapes has not been examined. We present measurements of the swimming of Cuvierina columnella, a warm water species with an elongated non-spiraled shell collected off the coast of Bermuda. With a body length of 9 mm, wing beat frequency of 4-6 Hz and swimming speed of 35 mm/s, these organisms swim at a Reynolds number of approximately 300, larger than that of L. helicina. High speed 3D kinematics acquired via two orthogonal cameras reveals that the elongated shell correlates with reduced body pitching and that the wings bend approximately 180 degrees in each direction, overlapping at the end of each half-stroke. Time resolved 2D flow measurements collected with a micro-PIV system reveal leading edge vortices present in both power and recovery strokes. Interactions between the overlapping wings and the shell also likely play a role in lift generation.

  8. Numerical Simulation of the Layer-Bylayer Destruction of Cylindrical Shells Under Explosive Loading

    NASA Astrophysics Data System (ADS)

    Abrosimov, N. A.; Novoseltseva, N. A.

    2015-09-01

    A technique of numerical analysis of the influence of reinforcement structure on the nature of the dynamic response and the process of layer-by-layer destruction of layered fiberglass cylindrical shells under an axisymmetric internal explosive loading is elaborated. The kinematic model of deformation of the laminate package is based on a nonclassical theory of shells. The geometric dependences are based on simple quadratic relations of the nonlinear theory of elasticity. The relationship between the stress and strain tensors are established by using Hooke's law for orthotropic bodies with account of degradation of stiffness characteristics of the multilayer composite due to the local destruction of some its elementary layers. An energetically consistent system of dynamic equations for composite cylindrical shells is obtained by minimizing the functional of total energy of the shell as a three-dimensional body. The numerical method for solving the formulated initial boundary-value problem is based on an explicit variational-difference scheme. Results confirming the reliability of the method used to analyze the influence of reinforcement structure on the character of destruction and the bearing capacity of pulse-loaded cylindrical shells are presented.

  9. Interacting shells in AdS spacetime and chaos

    NASA Astrophysics Data System (ADS)

    Brito, Richard; Cardoso, Vitor; Rocha, Jorge V.

    2016-07-01

    We study the simplest two-body problem in asymptotically anti-de Sitter spacetime: two, infinitely thin, concentric spherical shells of matter. We include only gravitational interaction between the two shells, but we show that the dynamics of this system is highly nontrivial. We observe prompt collapse to a black hole, delayed collapse and even perpetual oscillatory motion, depending on the initial location of the shells (or their energy content). The system exhibits critical behavior, and we show strong hints that it is also chaotic.

  10. Effects of egg shell quality and washing on Salmonella Infantis penetration.

    PubMed

    Samiullah; Chousalkar, K K; Roberts, J R; Sexton, M; May, D; Kiermeier, A

    2013-07-15

    The vast majority of eggs in Australia are washed prior to packing to remove dirt and fecal material and to reduce the microbial contamination of the egg shell. The egg contents can be an ideal growth medium for microorganisms which can result in human illness if eggs are stored improperly and eaten raw or undercooked, and it is estimated that egg-related salmonellosis is costing Australia $44 million per year. Egg shell characteristics such as shell thickness, amount of cuticle present, and thickness of individual egg shell layers can affect the ease with which bacteria can penetrate the egg shell and washing could partially or completely remove the cuticle layer. The current study was conducted to investigate the effects of egg washing on cuticle cover and effects of egg shell quality and cuticle cover on Salmonella Infantis penetration of the egg shell. A higher incidence of unfavorable ultrastructural variables of the mammillary layer such as late fusion, type B bodies, type A bodies, poor cap quality, alignment, depression, erosion and cubics were recorded in Salmonella penetrated areas of egg shells. The influence of egg washing on the ability of Salmonella Infantis on the egg shell surface to enter the egg internal contents was also investigated using culture-based agar egg penetration and real-time qPCR based experiments. The results from the current study indicate that washing affected cuticle cover. There were no significant differences in Salmonella Infantis penetration of washed or unwashed eggs. Egg shell translucency may have effects on Salmonella Infantis penetration of the egg shell. The qPCR assay was more sensitive for detection of Salmonella Infantis from egg shell wash and internal contents than traditional microbiological methods. The agar egg and whole egg inoculation experiments indicated that Salmonella Infantis penetrated the egg shells. Egg washing not only can be highly effective at removing Salmonella Infantis from the egg shell surface, but also allows subsequent trans-shell and trans-membrane penetration into the egg. Consequently, it is important to prevent recontamination of the egg after washing. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Water-soluble pH-responsive dendritic core-shell nanocarriers for polar dyes based on poly(ethylene imine).

    PubMed

    Xu, Shangjie; Luo, Ying; Haag, Rainer

    2007-08-07

    A simple general synthetic concept to build dendritic core-shell architectures with pH-labile linkers based on hyperbranched PEI cores and biocompatible PEG shells is presented. Using these dendritic core-shell architectures as nanocarriers, the encapsulation and transport of polar dyes of different sizes is studied. The results show that the acid-labile nanocarriers exhibit much higher transport capacities for dyes than unfunctionalized hyperbranched PEI. The cleavage of imine bonds and controlled release of the polar dyes revealed that weak acidic condition (pH approximately 5.0) could cleave the imine bonds linker and release the dyes up to five times faster than neutral conditions (pH = 7.4).

  12. Mathematical Modeling of Electrodynamics Near the Surface of Earth and Planetary Water Worlds

    NASA Technical Reports Server (NTRS)

    Tyler, Robert H.

    2017-01-01

    An interesting feature of planetary bodies with hydrospheres is the presence of an electrically conducting shell near the global surface. This conducting shell may typically lie between relatively insulating rock, ice, or atmosphere, creating a strong constraint on the flow of large-scale electric currents. All or parts of the shell may be in fluid motion relative to main components of the rotating planetary magnetic field (as well as the magnetic fields due to external bodies), creating motionally-induced electric currents that would not otherwise be present. As such, one may expect distinguishing features in the types of electrodynamic processes that occur, as well as an opportunity for imposing specialized mathematical methods that efficiently address this class of application. The purpose of this paper is to present and discuss such specialized methods. Specifically, thin-shell approximations for both the electrodynamics and fluid dynamics are combined to derive simplified mathematical formulations describing the behavior of these electric currents as well as their associated electric and magnetic fields. These simplified formulae allow analytical solutions featuring distinct aspects of the thin-shell electrodynamics in idealized cases. A highly efficient numerical method is also presented that is useful for calculations under inhomogeneous parameter distributions. Finally, the advantages as well as limitations in using this mathematical approach are evaluated. This evaluation is presented primarily for the generic case of bodies with water worlds or other thin spherical conducting shells. More specific discussion is given for the case of Earth, but also Europa and other satellites with suspected oceans.

  13. Body shape helps legged robots climb and turn in complex 3-D terrains

    NASA Astrophysics Data System (ADS)

    Han, Yuanfeng; Wang, Zheliang; Li, Chen

    Analogous to streamlined shapes that reduce drag in fluids, insects' ellipsoid-like rounded body shapes were recently discovered to be ``terradynamically streamlined'' and enhance locomotion in cluttered terrain by facilitating body rolling. Here, we hypothesize that there exist more terradynamic shapes that facilitate other modes of locomotion like climbing and turning in complex 3-D terrains by facilitating body pitching and yawing. To test our hypothesis, we modified the body shape of a legged robot by adding an elliptical and a rectangular shell and tested how it negotiated with circular and square vertical pillars. With a rectangular shell the robot always pitched against square pillars in an attempt to climb, whereas with an elliptical shell it always yawed and turned away from circular pillars given a small initial lateral displacement. Square / circular pillars facilitated pitching / yawing, respectively. To begin to reveal the contact physics, we developed a locomotion energy landscape model. Our model revealed that potential energy barriers to transition from pitching to yawing are high for angular locomotor and obstacle shapes (rectangular / square) but vanish for rounded shapes (elliptical / circular). Our study supports the plausibility of locomotion energy landscapes for understanding the rich locomotor transitions in complex 3-D terrains.

  14. Modeling the Electrostatics of Hollow Shell Suspensions: Ion Distribution, Pair Interactions, and Many-Body Effects.

    PubMed

    Hallez, Yannick; Meireles, Martine

    2016-10-11

    Electrostatic interactions play a key role in hollow shell suspensions as they determine their structure, stability, thermodynamics, and rheology and also the loading capacity of small charged species for nanoreservoir applications. In this work, fast, reliable modeling strategies aimed at predicting the electrostatics of hollow shells for one, two, and many colloids are proposed and validated. The electrostatic potential inside and outside a hollow shell with a finite thickness and a specific permittivity is determined analytically in the Debye-Hückel (DH) limit. An expression for the interaction potential between two such hollow shells is then derived and validated numerically. It follows a classical Yukawa form with an effective charge depending on the shell geometry, permittivity, and inner and outer surface charge densities. The predictions of the Ornstein-Zernike (OZ) equation with this pair potential to determine equations of state are then evaluated by comparison to results obtained with a Brownian dynamics algorithm coupled to the resolution of the linearized Poisson-Boltzmann and Laplace equations (PB-BD simulations). The OZ equation based on the DLVO-like potential performs very well in the dilute regime as expected, but also quite well, and more surprisingly, in the concentrated regime in which full spheres exhibit significant many-body effects. These effects are shown to vanish for shells with small thickness and high permittivity. For highly charged hollow shells, we propose and validate a charge renormalization procedure. Finally, using PB-BD simulations, we show that the cell model predicts the ion distribution inside and outside hollow shells accurately in both electrostatically dilute and concentrated suspensions. We then determine the shell loading capacity as a function of salt concentration, volume fraction, and surface charge density for nanoreservoir applications such as drug delivery, sensing, or smart coatings.

  15. Axisymmetric bluff-body flow: A vortex solver for thin shells

    NASA Astrophysics Data System (ADS)

    Strickland, J. H.

    1992-05-01

    A method which is capable of solving the axisymmetric flow field over bluff bodies consisting of thin shells such as disks, partial spheres, rings, and other such shapes is presented in this report. The body may be made up of several shells whose edges are separated by gaps. The body may be moved axially according to arbitrary velocity time histories. In addition, the surfaces may possess axial and radial degrees of flexibility such that points on the surfaces may be allowed to move relative to each other according to some specified function of time. The surfaces may be either porous or impervious. The present solution technique is based on the axisymmetric vorticity transport equation. Physically, this technique simulates the generation of vorticity at body surfaces in the form of discrete ring vortices which are subsequently diffused and convected into the boundary layers and wake of the body. Relatively large numbers of vortices (1000 or more) are required to obtain good simulations. Since the direct calculation of perturbations from large numbers of ring vortices is computationally intensive, a fast multipole method was used to greatly reduce computer processing time. Several example calculations are presented for disks, disks with holes, hemispheres, and vented hemispheres. These results are compared with steady and unsteady experimental data.

  16. Nonobservable nature of the nuclear shell structure: Meaning, illustrations, and consequences

    NASA Astrophysics Data System (ADS)

    Duguet, T.; Hergert, H.; Holt, J. D.; Somà, V.

    2015-09-01

    Background: The concept of single-nucleon shells constitutes a basic pillar of our understanding of nuclear structure. Effective single-particle energies (ESPEs) introduced by French [Proceedings of the International School of Physics "Enrico Fermi," Course XXXVI, Varenna 1965, edited by C. Bloch (Academic Press, New York, 1966)] and Baranger [Nucl. Phys. A 149, 225 (1970), 10.1016/0375-9474(70)90692-5] represent the most appropriate tool to relate many-body observables to a single-nucleon shell structure. As briefly discussed in Duguet and Hagen [Phys. Rev. C 85, 034330 (2012), 10.1103/PhysRevC.85.034330], the dependence of ESPEs on one-nucleon transfer probability matrices makes them purely theoretical quantities that "run" with the nonobservable resolution scale λ employed in the calculation. Purpose: Given that ESPEs provide a way to interpret the many-body problem in terms of simpler theoretical ingredients, the goal is to specify the terms, i.e., the exact sense and conditions, in which this interpretation can be conducted meaningfully. Methods: While the nuclear shell structure is both scale and scheme dependent, the present study focuses on the former. A detailed discussion is provided to illustrate the scale (in)dependence of observables and nonobservables and the reasons why ESPEs, i.e., the shell structure, belong to the latter category. State-of-the-art multireference in-medium similarity renormalization group and self-consistent Gorkov Green's function many-body calculations are employed to corroborate the formal analysis. This is done by comparing the behavior of several observables and of nonobservable ESPEs (and spectroscopic factors) under (quasi) unitary similarity renormalization group transformations of the Hamiltonian parametrized by the resolution scale λ . Results: The formal proofs are confirmed by the results of ab initio many-body calculations in their current stage of implementation. In practice, the unitarity of the similarity transformations is broken owing to the omission of induced many-body interactions beyond three-body operators and to the nonexact treatment of the many-body Schrödinger equation. The impact of this breaking is first characterized by quantifying the artificial running of observables over a (necessarily) finite interval of λ values. Then the genuine running of ESPEs is characterized and shown to be convincingly larger than the one of observables (which would be zero in an exact calculation). Conclusions: The nonobservable nature of the nuclear shell structure, i.e., the fact that it constitutes an intrinsically theoretical object with no counterpart in the empirical world, must be recognized and assimilated. Indeed, the shell structure cannot be determined uniquely from experimental data and cannot be talked about in an absolute sense as it depends on the nonobservable resolution scale employed in the theoretical calculation. It is only at the price of fixing arbitrarily (but conveniently) such a scale that one can establish correlations between observables and the shell structure. To some extent, fixing the resolution scale provides ESPEs (and spectroscopic factors) with a quasi-observable character. Eventually, practitioners can refer to nuclear shells and spectroscopic factors in their analyses of nuclear phenomena if, and only if, they use consistent structure and reaction theoretical schemes based on a fixed resolution scale they have agreed on prior to performing their analysis and comparisons.

  17. Evaluation of 18F-labeled targeted perfluorocarbon-filled albumin microbubbles as a probe for microUS and microPET in tumor-bearing mice.

    PubMed

    Liao, Ai-Ho; Wu, Shih-Yen; Wang, Hsin-Ell; Weng, Chien-Hsiu; Wu, Ming-Fang; Li, Pai-Chi

    2013-02-01

    In this study, albumin-shelled, targeted MBs (tMBs) were first demonstrated with the expectation of visualization of biodistribution of albumin-shelled tMBs. The actual biodistribution of albumin-shelled tMBs is of vital importance either for molecular imaging or for drug delivery. Recently, albumin microbubbles (MBs) have been studied for drug and gene delivery in vitro and in vivo through cavitation. Targeted lipid-shelled MBs have been applied for ultrasound molecular imaging and conjugated with radiolabeled antibodies for whole-body biodistribution evaluations. The novelty of the work is that, in addition to the lipid tMBs, the albumin tMBs was also applied in biodistribution detection. Multimodality albumin-shelled, (18)F-SFB-labeled VEGFR2 tMBs were synthesized, and their characteristics in mice bearing MDA-MB-231 human breast cancer were investigated with micro-positron-emission tomography (microPET) and high-frequency ultrasound (microUS). Albumin-shelled MBs can be labeled with (18)F-SFB directly and conjugated with antibodies for dual molecular imaging. The albumin-shelled tMBs show a lifetime in 30min in the blood pool and a highly specific adherence to tumor vessels in mice bearing human breast cancer. From the evaluations of whole-body biodistribution, the potential of the dual molecular imaging probe for drug or gene delivery in animal experiments with albumin shelled MBs has been investigated. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Classrooms Offer Quiet Academic Environment

    ERIC Educational Resources Information Center

    Garbrecht, Marilyn

    1977-01-01

    A building shell at Southern Illinois University has partitions that can be repositioned to suit changing needs. Silencing, heating, and cooling equipment received close attention to eliminate noise. The University of Minnesota has a new underground building housing a bookstore and offices that does not require heating. (Author/MLF)

  19. Extend MANPADS M&S Capabilities to Include Energetic Materials, Fragmentation Effects, and Wing Flutter Response

    DTIC Science & Technology

    2005-12-31

    MANPADS missile is modeled using LSDYNA . It has 187600 nodes, 52802 shell elements with 13 shell materials, 112200 solid elements with 1804 solid...model capability that includes impact, detonation, penetration, and wing flutter response. This work extends an existing body on body missile model...the missile as well as the expansion of the surrounding fluids was modeled in the Eulerian domain. The Jones-Wilkins-Lee (JWL) equation of state was

  20. Body Build Satisfaction and the Congruency of Body Build Perceptions.

    ERIC Educational Resources Information Center

    Hankins, Norman E.; Bailey, Roger C.

    1979-01-01

    Females were administered the somatotype rating scale. Satisfied subjects showed greater congruency between their own and wished-for body build, and greater congruency between their own and friend/date body builds, but less congruency between their own body build and the female stereotype. (Author/BEF)

  1. Vitellogenesis in Archigetes sieboldi Leuckart, 1878 (Cestoda, Caryophyllidea, Caryophyllaeidae), an intestinal parasite of carp (Cyprinus carpio L.).

    PubMed

    Brunanská, M; Mackiewicz, J S; Nebesárová, J

    2012-12-01

    Vitellogenesis in the caryophyllidean tapeworm Archigetes sieboldi Leuckart, 1878, from carp Cyprinus carpio L. in Slovakia, has been examined using transmission electron microscopy and cytochemical staining with periodic acid-thiosemicarbazide-silver proteinate (PA-TSC-SP) for glycogen. Vitelline follicles extend in two lateral bands in the medullary parenchyma along both sides of the monozoic body. They are surrounded by an external basal lamina and contain vitellocytes and an interstitial tissue. The general pattern of vitellogenesis is essentially like that of other caryophyllideans. It involves four stages: immature, early maturing, advanced maturing cells and mature vitellocytes. During vitellogenesis, a continuous increase in cell volume is accompanied by an extensive development of cell components engaged in shell globule formation, e.g. granular endoplasmic reticulum and Golgi. Shell globule clusters are membrane-bound. Nuclear and nucleolar transformation are associated with formation and storage of large amounts of intranuclear glycogen, a very specific feature of the Caryophyllidea. For the first time, (a) additional vitelline material in Archigetes is represented by lamellar bodies and (b) lipid droplets are described in the mature vitellocytes from vitelline follicles and vitelloduct of the Caryophyllidea. Our results indicate that there may be a double origin of lamellar bodies: either from the endoplasmic reticulum or through transformation of shell globule/shell globule clusters. Lamellar body clusters and some single lamellar bodies appear to have a membrane. Other ultrastructural features of vitellogenesis and/or vitellocyte in A. sieboldi from its vertebrate (fish) and invertebrate (oligochaete) hosts are briefly compared and contrasted with those in other caryophyllideans and/or Neodermata.

  2. Combining protein-shelled platinum nanoparticles with graphene to build a bionanohybrid capacitor.

    PubMed

    San, Boi Hoa; Kim, Jang Ah; Kulkarni, Atul; Moh, Sang Hyun; Dugasani, Sreekantha Reddy; Subramani, Vinod Kumar; Thorat, Nanasaheb D; Lee, Hyun Ho; Park, Sung Ha; Kim, Taesung; Kim, Kyeong Kyu

    2014-12-23

    The electronic properties of biomolecules and their hybrids with inorganic materials can be utilized for the fabrication of nanoelectronic devices. Here, we report the charge transport behavior of protein-shelled inorganic nanoparticles combined with graphene and demonstrate their possible application as a bionanohybrid capacitor. The conductivity of PepA, a bacterial aminopeptidase used as a protein shell (PS), and the platinum nanoparticles (PtNPs) encapsulated by PepA was measured using a field effect transistor (FET) and a graphene-based FET (GFET). Furthermore, we confirmed that the electronic properties of PepA-PtNPs were controlled by varying the size of the PtNPs. The use of two poly(methyl methacrylate) (PMMA)-coated graphene layers separated by PepA-PtNPs enabled us to build a bionanohybrid capacitor with tunable properties. The combination of bioinorganic nanohybrids with graphene is regarded as the cornerstone for developing flexible and biocompatible bionanoelectronic devices that can be integrated into bioelectric circuits for biomedical purposes.

  3. An easy-to-use diagnostic system development shell

    NASA Technical Reports Server (NTRS)

    Tsai, L. C.; Ross, J. B.; Han, C. Y.; Wee, W. G.

    1987-01-01

    The Diagnostic System Development Shell (DSDS), an expert system development shell for diagnostic systems, is described. The major objective of building the DSDS is to create a very easy to use and friendly environment for knowledge engineers and end-users. The DSDS is written in OPS5 and CommonLisp. It runs on a VAX/VMS system. A set of domain independent, generalized rules is built in the DSDS, so the users need not be concerned about building the rules. The facts are explicitly represented in a unified format. A powerful check facility which helps the user to check the errors in the created knowledge bases is provided. A judgement facility and other useful facilities are also available. A diagnostic system based on the DSDS system is question driven and can call or be called by other knowledge based systems written in OPS5 and CommonLisp. A prototype diagnostic system for diagnosing a Philips constant potential X-ray system has been built using the DSDS.

  4. Normal Modes of Vibration of the PHALANX Gun

    DTIC Science & Technology

    1993-06-01

    Clamps Bricks, Thin Shells, Rigid Elements Mid-Barrel Clamps Bricks, Rigid Elements Barrels Beams with tubular cross-section Stub Rotor Bricks, Thin...Shells Rotor Bricks Needle Bearing Bricks, Springs Casing Thin Shells Thrust Bearing Bricks, Springs Recoil Adapters Bricks, Rigid Elements, Springs... rigid elements were used to connect the barrels to the clamps and stub rotor and the recoil adapter springs to 48 the gun body. "End release codes

  5. Computer Modeling of the Dynamic Strength of Metal-Plastic Cylindrical Shells Under Explosive Loading

    NASA Astrophysics Data System (ADS)

    Abrosimov, N. A.; Novosel'tseva, N. A.

    2017-05-01

    A technique for numerically analyzing the dynamic strength of two-layer metal-plastic cylindrical shells under an axisymmetric internal explosive loading is developed. The kinematic deformation model of the layered package is based on a nonclassical theory of shells. The geometric relations are constructed using relations of the simplest quadratic version of the nonlinear elasticity theory. The stress and strain tensors in the composite macrolayer are related by Hooke's law for an orthotropic body with account of degradation of the stiffness characteristics of the multilayer package due to local failure of some its elementary layers. The physical relations in the metal layer are formulated in terms of a differential theory of plasticity. An energy-correlated resolving system of dynamic equations for the metal-plastic cylindrical shells is derived by minimizing the functional of total energy of the shells as three-dimensional bodies. The numerical method for solving the initial boundary-value problem formulated is based on an explicit variational-difference scheme. The reliability of the technique considered is verified by comparing numerical results with experimental data. An analysis of the ultimate strains and strength of one-layer basalt-and glass-fiber-reinforced plastic and two-layer metalplastic cylindrical shells is carried out.

  6. Chronic suppression of μ-opioid receptor signaling in the nucleus accumbens attenuates development of diet-induced obesity in rats.

    PubMed

    Lenard, N R; Zheng, H; Berthoud, H-R

    2010-06-01

    To test the hypothesis that micro-opioid receptor signaling in the nucleus accumbens contributes to hedonic (over)eating and obesity. To investigate the effects of chronic micro-opioid antagonism in the nucleus accumbens core or shell on intake of a palatable diet, and the development of diet-induced obesity in rats. Chronic blockade of micro-opioid receptor signaling in the nucleus accumbens core or shell was achieved by means of repeated injections (every 4-5 days) of the irreversible receptor antagonist beta-funaltrexamine (BFNA) over 3-5 weeks. The diet consisted of either a choice of high-fat chow, chocolate-flavored Ensure and regular chow (each nutritionally complete) or regular chow only. Intake of each food item, body weight and body fat mass were monitored throughout the study. The BFNA injections aimed at either the core or shell of the nucleus accumbens resulted in significantly attenuated intake of palatable diet, body weight gain and fat accretion, compared with vehicle control injections. The injection of BFNA in the core did not significantly change these parameters in chow-fed control rats. The injection of BFNA in the core and shell differentially affected intake of the two palatable food items: in the core, BFNA significantly reduced the intake of high-fat, but not of Ensure, whereas in the shell, it significantly reduced the intake of Ensure, but not of high-fat, compared with vehicle treatment. Endogenous micro-opioid receptor signaling in the nucleus accumbens core and shell is necessary for palatable diet-induced hyperphagia and obesity to fully develop in rats. Sweet and non-sweet fatty foods may be differentially processed in subcomponents of the ventral striatum.

  7. Nesting environment may drive variation in eggshell structure and egg characteristics in the Testudinata.

    PubMed

    Deeming, D Charles

    2018-05-14

    Testudines exhibit considerable variation in the degree of eggshell calcification, which affects eggshell conductance, water physiology of the embryos, and calcium metabolism of embryos. However, the underlying reason for different shell types has not been explored. Phylogenetically controlled analyses examined relationships between egg size, shell mass, and clutch size in ∼200 turtle species from a range of body sizes and assigned by family as laying either rigid- or pliable-shelled eggs. Shell type affected egg breadth relative to pelvic dimensions, egg mass, and relative shell mass but did not affect size, mass, or total shell mass of the clutch. These results suggest that calcium availability may be a function of body size and the type of shell may reflect in part the interplay between clutch size and egg size. It was further concluded that the eggshell probably evolved as a means of physical protection. Differences in shell calcification may not primarily reflect reproductive parameters but rather correlate with the acidity of a species' nesting environment. Low pH environments may have thicker calcareous layer to counteract the erosion caused by the soil and maintain the integrity of the physical barrier. Limited calcium availability may constrain clutch size. More neutral nesting substrates expose eggshells to less erosion so calcification per egg can be reduced and this allows larger clutch sizes. This pattern is also reflected in thick, calcified crocodilian eggs. Further research is needed to test whether eggshell calcification in the testudines correlates with nest pH in order to verify this relationship. © 2018 Wiley Periodicals, Inc.

  8. Comparison of different building shells - life cycle assessment.

    PubMed

    Rixrath, Doris; Wartha, Christian

    2016-07-01

    The Renewable Energy and Efficiency Action (REACT) project is a European Union-funded cross-border cooperative venture featuring the participation of companies and researchers from the Austrian state of Burgenland and western Slovakia that is developing zero-energy concepts for newly built single-family homes. A variety of building structures are defined for family houses, and the different impacts they have on the environment are evaluated over the entire life cycle. This paper aims to compare the environmental impacts of different building shells during both the construction and the demolition phases. However, the operation phase of the building is not evaluated. One of the findings of the project thus far is that the demolition and disposal of building materials should be included in any such evaluation. For some environmental impact assessment categories, both demolition and disposal are important. The environmental impacts of various end-of-life scenarios can differ greatly based on the disposal method (e.g., landfill, incineration, recycling) chosen and on the proportion of recycled content. Furthermore, the results show that manufacturing building materials from renewable resources can have strong environmental impacts, particularly when substantial amounts of fossil fuel are required in their production. Integr Environ Assess Manag 2016;12:437-444. © 2016 SETAC. © 2016 SETAC.

  9. On-shell constrained M 2 variables with applications to mass measurements and topology disambiguation

    NASA Astrophysics Data System (ADS)

    Cho, Won Sang; Gainer, James S.; Kim, Doojin; Matchev, Konstantin T.; Moortgat, Filip; Pape, Luc; Park, Myeonghun

    2014-08-01

    We consider a class of on-shell constrained mass variables that are 3+1 dimensional generalizations of the Cambridge M T2 variable and that automatically incorporate various assumptions about the underlying event topology. The presence of additional on-shell constraints causes their kinematic distributions to exhibit sharper endpoints than the usual M T2 distribution. We study the mathematical properties of these new variables, e.g., the uniqueness of the solution selected by the minimization over the invisible particle 4-momenta. We then use this solution to reconstruct the masses of various particles along the decay chain. We propose several tests for validating the assumed event topology in missing energy events from new physics. The tests are able to determine: 1) whether the decays in the event are two-body or three-body, 2) if the decay is two-body, whether the intermediate resonances in the two decay chains are the same, and 3) the exact sequence in which the visible particles are emitted from each decay chain.

  10. Deployment of Large-Size Shell Constructions by Internal Pressure

    NASA Astrophysics Data System (ADS)

    Pestrenin, V. M.; Pestrenina, I. V.; Rusakov, S. V.; Kondyurin, A. V.

    2015-11-01

    A numerical study on the deployment pressure (the minimum internal pressure bringing a construction from the packed state to the operational one) of large laminated CFRP shell structures is performed using the ANSYS engineering package. The shell resists both membrane and bending deformations. Structures composed of shell elements whose median surface has an involute are considered. In the packed (natural) states of constituent elements, the median surfaces coincide with their involutes. Criteria for the termination of stepwise solution of the geometrically nonlinear problem on determination of the deployment pressure are formulated, and the deployment of cylindrical, conical (full and truncated cones), and large-size composite shells is studied. The results obtained are shown by graphs illustrating the deployment pressure in relation to the geometric and material parameters of the structure. These studies show that large pneumatic composite shells can be used as space and building structures, because the deployment pressure in them only slightly differs from the excess pressure in pneumatic articles made from films and soft materials.

  11. Design and Analysis of Tow-Steered Composite Shells Using Fiber Placement

    NASA Technical Reports Server (NTRS)

    Wu, K. Chauncey

    2008-01-01

    In this study, a sub-scale advanced composite shell design is evaluated to determine its potential for use on a future aircraft fuselage. Two composite shells with the same nominal 8-ply [+/-45/+/-Theta](sub s) layup are evaluated, where Theta indicates a tow-steered ply. To build this shell, a fiber placement machine would be used to steer unidirectional prepreg tows as they are placed around the circumference of a 17-inch diameter right circular cylinder. The fiber orientation angle varies continuously from 10 degrees (with respect to the shell axis of revolution) at the crown, to 45 degrees on the side, and back to 10 degrees on the keel. All 24 tows are placed at each point on every fiber path in one structure designated as the shell with overlaps. The resulting pattern of tow overlaps causes the laminate thickness to vary between 8 and 16 plies. The second shell without tow overlaps uses the capability of the fiber placement machine to cut and add tows at any point along the fiber paths to fabricate a shell with a nearly uniform 8-ply laminate thickness. Issues encountered during the design and analysis of these shells are presented and discussed. Static stiffness and buckling loads of shells with tow-steered layups are compared with the performance of a baseline quasi-isotropic shell using both finite element analyses and classical strength of materials theory.

  12. The role of feeding morphology and competition in governing the diet breadth of sympatric stomatopod crustaceans.

    PubMed

    deVries, Maya S

    2017-04-01

    Competition for food drives divergence and specialization in feeding morphology. Stomatopod crustaceans have two kinds of highly specialized feeding appendages: either elongate spear-like appendages ( spearers ) used to ambush soft-bodied evasive prey or hammer-like appendages ( smashers ) that produce extremely high forces used both to break hard-shelled prey and to capture evasive prey. To evaluate associations between appendage type and feeding ecology, the diet of two small smasher and spearer species (size range: 21-27 mm) that co-occur were compared. Stable isotope analysis and the Bayesian mixing model MixSIAR were used to estimate the proportional contributions of prey types to the diet. Both species had relatively wide diets that included hard-shelled and soft-bodied prey, albeit in different proportions; the smasher consumed a greater proportion of hard-shelled prey, and the spearer consumed mostly soft-bodied prey. Appendage kinematics in stomatopods is known to scale linearly across species. These two small species may produce similar kinematics allowing them both to capture evasive prey and hammer hard-shelled prey, thereby widening their diets. Yet, the spearer species is more highly adept at capturing evasive prey, indicating that small spearers are stronger competitors for soft-bodied prey. These findings suggest that a smasher's ability to access hard prey reduced competition for soft prey, and therefore conferred an important benefit favouring the evolution of the impressive smashing strike. © 2017 The Author(s).

  13. Simulation of Double-Seaming in a Two-piece Aluminum Can

    NASA Astrophysics Data System (ADS)

    Romanko, Anne; Berry, Dale; Fox, David

    2004-06-01

    The aluminum can industry in the United States and Canada manufactures over 100 billion cans per year. Two-piece aluminum cans are commonly used to seal and deliver foodstuffs such as soft drinks, beer, pet food, and other perishable items. In order to ensure product safety and performance, the double seam between the can body and lid is a critical component of the package. Double-seaming is a method by which the flange of the can body and the curl of the end are folded over together such that the final joint is composed of five metal thicknesses. There are a number of design challenges involved with the art of double seaming, especially with the push to lightweight. Although the requirements vary by product, the typical beer package must be able to hold pressures in excess of 90psi. In addition, in production, double seaming is a high-speed operation with speeds as high as 3000 cans/minute on an 18-spindle seamer. For this high volume, low cost industry, understanding and optimizing the seaming process can advance the industry as well as help prevent various manufacturing problems that produce a poor seal between the two pieces of the can. To aid in understanding the mechanics of the can parts during double-seaming, a simulation procedure was developed and carried out on a 202 diameter beverage can and lid. Simulations were run with the explicit dynamics solver ABAQUS/Explicit using the continuum shell element technology available in the ABAQUS general purpose FEA program. The continuum shell is a shear-deformable shell element with the topology of an eight node brick. The element's formulation allows continuously varying, solution-dependent shell thickness and through-thickness pinching stress. One important advantage of using the continuum shell as opposed to a traditional shell element is that true contact interactions at the top and bottom surfaces of the can body and lid can be accurately modeled. With a conventional shell element, contact is performed at the shell mid-surface or at an offset point representing where the top or bottom surface is expected to be. This paper discusses this new simulation technique and provides an example of its use.

  14. A Project to Design and Build Compact Heat Exchangers

    ERIC Educational Resources Information Center

    Davis, Richard A.

    2005-01-01

    Students designed and manufactured compact, shell-and-tube heat exchangers in a project-based learning exercise integrated with our heat transfer course. The heat exchangers were constructed from common building materials available at home improvement centers. The cost of materials for a device was less than $20. The project gave students…

  15. Contact solution algorithms

    NASA Technical Reports Server (NTRS)

    Tielking, John T.

    1989-01-01

    Two algorithms for obtaining static contact solutions are described in this presentation. Although they were derived for contact problems involving specific structures (a tire and a solid rubber cylinder), they are sufficiently general to be applied to other shell-of-revolution and solid-body contact problems. The shell-of-revolution contact algorithm is a method of obtaining a point load influence coefficient matrix for the portion of shell surface that is expected to carry a contact load. If the shell is sufficiently linear with respect to contact loading, a single influence coefficient matrix can be used to obtain a good approximation of the contact pressure distribution. Otherwise, the matrix will be updated to reflect nonlinear load-deflection behavior. The solid-body contact algorithm utilizes a Lagrange multiplier to include the contact constraint in a potential energy functional. The solution is found by applying the principle of minimum potential energy. The Lagrange multiplier is identified as the contact load resultant for a specific deflection. At present, only frictionless contact solutions have been obtained with these algorithms. A sliding tread element has been developed to calculate friction shear force in the contact region of the rolling shell-of-revolution tire model.

  16. Strategies Toward Well-Defined Polymer Nanoparticles Inspired by Nature: Chemistry versus Versatility

    PubMed Central

    Elsabahy, Mahmoud; Wooley, Karen L.

    2014-01-01

    Polymeric nanoparticles are promising delivery platforms for various biomedical applications. One of the main challenges toward the development of therapeutic nanoparticles is the premature disassembly and release of the encapsulated drug. Among the different strategies to enhance the kinetic stability of polymeric nanoparticles, shell- and core-crosslinking have been shown to provide robust character, while creating a suitable environment for encapsulation of a wide range of therapeutics, including hydrophilic, hydrophobic, metallic, and small and large biomolecules, with gating of their release as well. The versatility of shell- and core-crosslinked nanoparticles is driven from the ease by which the structures of the shell- and core-forming polymers and crosslinkers can be modified. In addition, postmodification with cell-recognition moieties, grafting of antibiofouling polymers, or chemical degradation of the core to yield nanocages allow the use of these robust nanostructures as “smart” nanocarriers. The building principles of these multifunctional nanoparticles borrow analogy from the synthesis, supramolecular assembly, stabilization, and dynamic activity of the naturally driven biological nanoparticles such as proteins, lipoproteins, and viruses. In this review, the chemistry involved during the buildup from small molecules to polymers to covalently stabilized nanoscopic objects is detailed, with contrast of the strategies of the supramolecular assembly of polymer building blocks followed by intramicellar stabilization into shell-, core-, or core–shell-crosslinked knedel-like nanoparticles versus polymerization of polymers into nanoscopic molecular brushes followed by further intramolecular covalent stabilization events. The rational design of shell-crosslinked knedel-like nanoparticles is then elaborated for therapeutic packaging and delivery, with emphasis on the polymer chemistry aspects to accomplish the synthesis of such nanoparticulate systems. PMID:25574072

  17. Shock Waves Mitigation at Blunt Bodies Using Needles and Shells Against a Supersonic Flow

    NASA Technical Reports Server (NTRS)

    Gilinsky, M.; Blankson, I. M.; Sakharov, V. I.; Shvets, A. I.

    2004-01-01

    The paper contains some experimental and numerical simulation test results on cylindrical blunt body drag reduction using thin spikes or shell mounted in front of a body against a supersonic flow. Experimental tests were conducted using the Aeromechanics and Gas Dynamics Laboratory facilities at the Institute of Mechanics of Moscow State University (IMMSU). Numerical simulations utilizing NASA and IM/MSU codes were conducted at the Hampton University Fluid Mechanics and Acoustics Laboratory. The main purpose of this research is to examine the efficiency of application of multiple spikes for drag reduction and flow stability at the front of a blunt body in different flight conditions, i.e. Mach number, angle of attack, etc. The principal conclusions of these test results are: multiple spike/needle application leads to decrease of drag reduction benefits by comparison with the case of one central mounted needle at the front of a blunt body, but increase lift benefits.

  18. Effective operators in a single-j orbital

    NASA Astrophysics Data System (ADS)

    Derbali, E.; Van Isacker, P.; Tellili, B.; Souga, C.

    2018-03-01

    We present an analysis of effective operators in the shell model with up to three-body interactions in the Hamiltonian and two-body terms in electromagnetic transition operators when the nucleons are either neutrons or protons occupying a single-j orbital. We first show that evidence for an effective three-body interaction exists in the N = 50 isotones and in the lead isotopes but that the separate components of such interaction are difficult to obtain empirically. We then determine higher-order terms on more microscopic grounds. The starting point is a realistic two-body interaction in a large shell-model space together with a standard one-body transition operator, which, after restriction to the dominant orbital and with use of stationary perturbation theory, are transformed into effective versions with higher-order terms. An application is presented for the lead isotopes with neutrons in the 1{g}9/2 orbital.

  19. 42 CFR 52b.2 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... of, or the completion of shell space in, existing buildings (including the installation of fixed... Health. Modernization means the alteration, renovation, remodeling, improvement, expansion, and/or repair...

  20. 42 CFR 52b.2 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... of, or the completion of shell space in, existing buildings (including the installation of fixed... Health. Modernization means the alteration, renovation, remodeling, improvement, expansion, and/or repair...

  1. 42 CFR 52b.2 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... of, or the completion of shell space in, existing buildings (including the installation of fixed... Health. Modernization means the alteration, renovation, remodeling, improvement, expansion, and/or repair...

  2. Reconfigurable Polymer Shells on Shape-Anisotropic Gold Nanoparticle Cores.

    PubMed

    Kim, Juyeong; Song, Xiaohui; Kim, Ahyoung; Luo, Binbin; Smith, John W; Ou, Zihao; Wu, Zixuan; Chen, Qian

    2018-05-03

    Reconfigurable hybrid nanoparticles made by decorating flexible polymer shells on rigid inorganic nanoparticle cores can provide a unique means to build stimuli-responsive functional materials. The polymer shell reconfiguration has been expected to depend on the local core shape details, but limited systematic investigations have been undertaken. Here, two literature methods are adapted to coat either thiol-terminated polystyrene (PS) or polystyrene-poly(acrylic acid) (PS-b-PAA) shells onto a series of anisotropic gold nanoparticles of shapes not studied previously, including octahedron, concave cube, and bipyramid. These core shapes are complex, rendering shell contours with nanoscale details (e.g., local surface curvature, shell thickness) that are imaged and analyzed quantitatively using the authors' customized analysis codes. It is found that the hybrid nanoparticles based on the chosen core shapes, when coated with the above two polymer shells, exhibit distinct shell segregations upon a variation in solvent polarity or temperature. It is demonstrated for the PS-b-PAA-coated hybrid nanoparticles, the shell segregation is maintained even after a further decoration of the shell periphery with gold seeds; these seeds can potentially facilitate subsequent deposition of other nanostructures to enrich structural and functional diversity. These synthesis, imaging, and analysis methods for the hybrid nanoparticles of anisotropically shaped cores can potentially aid in their predictive design for materials reconfigurable from the bottom up. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Strain-induced structural defects and their effects on the electrochemical performances of silicon core/germanium shell nanowire heterostructures

    DOE PAGES

    Lin, Yung-Chen; Kim, Dongheun; Li, Zhen; ...

    2016-12-14

    Here we report on strain-induced structural defect formation in core Si nanowire of Si/Ge core/shell nanowire heterostructure and influences of the structural defects on the electrochemical performances in lithium-ion battery anodes based on Si/Ge core/shell nanowire heterostructures. The induced structural defects consisting of stacking faults and dislocations in the core Si nanowire were observed for the first time. The generation of stacking faults in Si/Ge core/shell nanowire heterostructure is observed to prefer settling in either only Ge shell region or in both Ge shell and Si core regions and is associated with the increase of the shell volume fraction. Themore » relax of misfit strain in [112] oriented core/shell nanowire heterostructure leads to subsequent gliding of Shockley partial dislocations, preferentially forming the twins. The observation of cross-over defect formation is of great importance for the understanding of heteroepitaxy in radial heterostructures at nanoscale and building the three dimensional heterostructures for the various applications. In addition, the effect of the defect formation on nanomaterial’s functionality is investigated by electrochemical performance test. The Si/Ge core/shell nanowire heterostructures enhance the gravimetric capacity of lithium ion battery anodes under fast charging/discharging rates compared to Si nanowires. However, the induced structural defects hamper lithiation of the Si/Ge core/shell nanowire heterostructure.« less

  4. Strain-induced structural defects and their effects on the electrochemical performances of silicon core/germanium shell nanowire heterostructures

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lin, Yung-Chen; Kim, Dongheun; Li, Zhen

    Here we report on strain-induced structural defect formation in core Si nanowire of Si/Ge core/shell nanowire heterostructure and influences of the structural defects on the electrochemical performances in lithium-ion battery anodes based on Si/Ge core/shell nanowire heterostructures. The induced structural defects consisting of stacking faults and dislocations in the core Si nanowire were observed for the first time. The generation of stacking faults in Si/Ge core/shell nanowire heterostructure is observed to prefer settling in either only Ge shell region or in both Ge shell and Si core regions and is associated with the increase of the shell volume fraction. Themore » relax of misfit strain in [112] oriented core/shell nanowire heterostructure leads to subsequent gliding of Shockley partial dislocations, preferentially forming the twins. The observation of cross-over defect formation is of great importance for the understanding of heteroepitaxy in radial heterostructures at nanoscale and building the three dimensional heterostructures for the various applications. In addition, the effect of the defect formation on nanomaterial’s functionality is investigated by electrochemical performance test. The Si/Ge core/shell nanowire heterostructures enhance the gravimetric capacity of lithium ion battery anodes under fast charging/discharging rates compared to Si nanowires. However, the induced structural defects hamper lithiation of the Si/Ge core/shell nanowire heterostructure.« less

  5. Elevated CO2 affects shell dissolution rate but not calcification rate in a marine snail.

    PubMed

    Nienhuis, Sarah; Palmer, A Richard; Harley, Christopher D G

    2010-08-22

    As CO(2) levels increase in the atmosphere, so too do they in the sea. Although direct effects of moderately elevated CO(2) in sea water may be of little consequence, indirect effects may be profound. For example, lowered pH and calcium carbonate saturation states may influence both deposition and dissolution rates of mineralized skeletons in many marine organisms. The relative impact of elevated CO(2) on deposition and dissolution rates are not known for many large-bodied organisms. We therefore tested the effects of increased CO(2) levels--those forecast to occur in roughly 100 and 200 years--on both shell deposition rate and shell dissolution rate in a rocky intertidal snail, Nucella lamellosa. Shell weight gain per day in live snails decreased linearly with increasing CO(2) levels. However, this trend was paralleled by shell weight loss per day in empty shells, suggesting that these declines in shell weight gain observed in live snails were due to increased dissolution of existing shell material, rather than reduced production of new shell material. Ocean acidification may therefore have a greater effect on shell dissolution than on shell deposition, at least in temperate marine molluscs.

  6. 12. BUILDING 621, INTERIOR, GROUND FLOOR, LOOKING NORTHWEST AT SCREENING ...

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

    12. BUILDING 621, INTERIOR, GROUND FLOOR, LOOKING NORTHWEST AT SCREENING MACHINE THAT REMOVES SHELL FRAGMENTS. METALLIC DUST REMOVED BY MAGNETIC SEPERATOR UNDERNEATH SCREEN. SAWDUST IS RETURNED TO SAWDUST HOPPER BY ELEVATOR. HOODS OVER SCREENING MACHINE AT WORKBENCH REMOVE FINE SAWDUST. - Picatinny Arsenal, 600 Area, Test Areas District, State Route 15 near I-80, Dover, Morris County, NJ

  7. Hollow spherical shell manufacture

    DOEpatents

    O'Holleran, T.P.

    1991-11-26

    A process is disclosed for making a hollow spherical shell of silicate glass composition in which an aqueous suspension of silicate glass particles and an immiscible liquid blowing agent is placed within the hollow spherical cavity of a porous mold. The mold is spun to reduce effective gravity to zero and to center the blowing agent, while being heated so as to vaporize the immiscible liquid and urge the water carrier of the aqueous suspension to migrate into the body of the mold, leaving a green shell compact deposited around the mold cavity. The green shell compact is then removed from the cavity, and is sintered for a time and a temperature sufficient to form a silicate glass shell of substantially homogeneous composition and uniform geometry. 3 figures.

  8. Hollow spherical shell manufacture

    DOEpatents

    O'Holleran, Thomas P.

    1991-01-01

    A process for making a hollow spherical shell of silicate glass composition in which an aqueous suspension of silicate glass particles and an immiscible liquid blowing agent is placed within the hollow spherical cavity of a porous mold. The mold is spun to reduce effective gravity to zero and to center the blowing agent, while being heated so as to vaporize the immiscible liquid and urge the water carrier of the aqueous suspension to migrate into the body of the mold, leaving a green shell compact deposited around the mold cavity. The green shell compact is then removed from the cavity, and is sintered for a time and a temperature sufficient to form a silicate glass shell of substantially homogeneous composition and uniform geometry.

  9. Implementation of Free-Formulation-Based Flat Shell Elements into NASA Comet Code and Development of Nonlinear Shallow Shell Element

    NASA Technical Reports Server (NTRS)

    Barut, A.; Madenci, Erdogan; Tessler, A.

    1997-01-01

    This study presents a transient nonlinear finite element analysis within the realm of a multi-body dynamics formulation for determining the dynamic response of a moderately thick laminated shell undergoing a rapid and large rotational motion and nonlinear elastic deformations. Nonlinear strain measure and rotation, as well as 'the transverse shear deformation, are explicitly included in the formulation in order to capture the proper motion-induced stiffness of the laminate. The equations of motion are derived from the virtual work principle. The analysis utilizes a shear deformable shallow shell element along with the co-rotational form of the updated Lagrangian formulation. The shallow shell element formulation is based on the Reissner-Mindlin and Marguerre theory.

  10. Department of the Army Justification of Estimates for Fiscal Year 1985. Procurement Appropriations-Construction Program Submitted to Congress February 1984. DD Forms 1391.

    DTIC Science & Technology

    1984-02-01

    REQUIREMENT FOR CONSTRUCTION PROJECT: These buildings house electronic equipment, irreplaceable rocket motor design and performance records, a...consists of five subprojects which are to provide modern facilities designed for rocket motor production. These production efficient buildings will...replace facilities which were designed and built in 1930-1942 for artillery shell loading. Four of the sub- projects are for buildings while the fifth

  11. Design and Fabrication of a Ring-Stiffened Graphite-Epoxy Corrugated Cylindrical Shell

    NASA Technical Reports Server (NTRS)

    Johnson, R., Jr.

    1978-01-01

    Design and fabrication of supplement test panels that represent key portions of the cylinder are described, as are supporting tests of coupons, sample joints, and stiffening ring elements. The cylindrical shell is a ring-stiffened, open corrugation design that uses T300/5208 graphite-epoxy tape as the basic material for the shell wall and stiffening rings. The test cylinder is designed to withstand bending loads producing the relatively low maximum load intensity in the shell wall of 1,576 N/cm. The resulting shell wall weight, including stiffening rings and fasteners, is 0.0156 kg/m. The shell weight achieved in the graphite-epoxy cylinder represents a weight saving of approximately 23 percent, compared to a comparable aluminum shell. A unique fabrication approach was used in which the cylinder wall was built in three flat segments, which were then wrapped to the cylindrical shape. Such an approach, made possible by the flexibility of the thin corrugated wall in a radial direction, proved to be a simple approach to building the test cylinder. Based on tooling and fabrication methods in this program, the projected costs of a production run of 100 units are reported.

  12. The Effect of Body Build and BMI on Aerobic Test Performance in School Children (10-15 Years)

    PubMed Central

    Slinger, Jantine; Verstappen, Frans; Breda, Eric Van; Kuipers, Harm

    2006-01-01

    Body Mass Index (BMI) has often questionably been used to define body build. In the present study body build was defined more specifically using fat free mass index (FFMI = fat free mass normalised to the stature) and fat mass index (FMI = fat mass normalised to stature). The body build of an individual is ‘solid’ in individuals with a high FFMI for their FMI and is ‘slender’ in individuals with a low FFMI relative to their FMI. The aim of the present study was to investigate the association between aerobic test performance and body build defined as solid, average or slender in 10 to 15 year old children. Five-hundred-and-two children (53% boys) aged 10 to 15 years of age were included in the study. Aerobic test performance was estimated with an incremental cycle ergometer protocol and a shuttle run test. BMI and percentage fat (by skin folds) were determined to calculate FMI and FFMI. After adjustment for differences in age, gender and body mass the solid group achieved a significantly higher maximal power output (W) and power output relative to body mass (W/kg) during the cycle test (p < 0.05) and a higher shuttle-run score (p < 0.05) compared to the slender group. The power output relative to FFM (W/kg FFM) was comparable (p > 0.05) between different body build groups. This study showed that body build is an important determinant of the aerobic test performance. In contrast, there were no differences in aerobic test performance per kilogramme FFM over the body build groups. This suggests that the body build may be determined by genetic predisposition. Key Points Children with a solid body build perform better in aerobic exercise tests than slender children. The power output relative to fat free mass was comparable in the solid, slender and average group. Besides body composition, body build should be considered related to other performance measurements. PMID:24357967

  13. Ab initio Bogoliubov coupled cluster theory for open-shell nuclei

    DOE PAGES

    Signoracci, Angelo J.; Duguet, Thomas; Hagen, Gaute; ...

    2015-06-29

    Background: Ab initio many-body methods have been developed over the past 10 yr to address closed-shell nuclei up to mass A≈130 on the basis of realistic two- and three-nucleon interactions. A current frontier relates to the extension of those many-body methods to the description of open-shell nuclei. Several routes to address open-shell nuclei are currently under investigation, including ideas that exploit spontaneous symmetry breaking. Purpose: Singly open-shell nuclei can be efficiently described via the sole breaking of U(1) gauge symmetry associated with particle-number conservation as a way to account for their superfluid character. While this route was recently followed withinmore » the framework of self-consistent Green's function theory, the goal of the present work is to formulate a similar extension within the framework of coupled cluster theory. Methods: We formulate and apply Bogoliubov coupled cluster (BCC) theory, which consists of representing the exact ground-state wave function of the system as the exponential of a quasiparticle excitation cluster operator acting on a Bogoliubov reference state. Equations for the ground-state energy and the cluster amplitudes are derived at the singles and doubles level (BCCSD) both algebraically and diagrammatically. The formalism includes three-nucleon forces at the normal-ordered two-body level. The first BCC code is implemented in m scheme, which will permit the treatment of doubly open-shell nuclei via the further breaking of SU(2) symmetry associated with angular momentum conservation. Results: Proof-of-principle calculations in an N max=6 spherical harmonic oscillator basis for 16,18O and 18Ne in the BCCD approximation are in good agreement with standard coupled cluster results with the same chiral two-nucleon interaction, while 20O and 20Mg display underbinding relative to experiment. The breaking of U(1) symmetry, monitored by computing the variance associated with the particle-number operator, is relatively constant for all five nuclei, in both the Hartree-Fock-Bogoliubov and BCCD approximations. Conclusions: The newly developed many-body formalism increases the potential span of ab initio calculations based on single-reference coupled cluster techniques tremendously, i.e., potentially to reach several hundred additional midmass nuclei. The new formalism offers a wealth of potential applications and further extensions dedicated to the description of ground and excited states of open-shell nuclei. Short-term goals include the implementation of three-nucleon forces at the normal-ordered two-body level. Midterm extensions include the approximate treatment of triples corrections and the development of the equation-of-motion methodology to treat both excited states and odd nuclei. Long-term extensions include exact restoration of U(1) and SU(2) symmetries.« less

  14. Generic element processor (application to nonlinear analysis)

    NASA Technical Reports Server (NTRS)

    Stanley, Gary

    1989-01-01

    The focus here is on one aspect of the Computational Structural Mechanics (CSM) Testbed: finite element technology. The approach involves a Generic Element Processor: a command-driven, database-oriented software shell that facilitates introduction of new elements into the testbed. This shell features an element-independent corotational capability that upgrades linear elements to geometrically nonlinear analysis, and corrects the rigid-body errors that plague many contemporary plate and shell elements. Specific elements that have been implemented in the Testbed via this mechanism include the Assumed Natural-Coordinate Strain (ANS) shell elements, developed with Professor K. C. Park (University of Colorado, Boulder), a new class of curved hybrid shell elements, developed by Dr. David Kang of LPARL (formerly a student of Professor T. Pian), other shell and solid hybrid elements developed by NASA personnel, and recently a repackaged version of the workhorse shell element used in the traditional STAGS nonlinear shell analysis code. The presentation covers: (1) user and developer interfaces to the generic element processor, (2) an explanation of the built-in corotational option, (3) a description of some of the shell-elements currently implemented, and (4) application to sample nonlinear shell postbuckling problems.

  15. Zoology: Molluscs All Beneath the Sun, One Shell, Two Shells, More, or None.

    PubMed

    Sigwart, Julia D

    2017-07-24

    One great remaining problem in evolutionary biology is to understand which common ancestor could have given rise to descendants as different as giant squid and microscopic pea clams. Two new papers provide important insights into molluscan body plan disparity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. 46 CFR 67.3 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., cultivating, catching, taking, or harvesting fish, shellfish, marine animals, pearls, shells, or marine... which would commit them to use in the building of a vessel. Officer in Charge, Marine Inspection (OCMI...

  17. 46 CFR 67.3 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., cultivating, catching, taking, or harvesting fish, shellfish, marine animals, pearls, shells, or marine... which would commit them to use in the building of a vessel. Officer in Charge, Marine Inspection (OCMI...

  18. The draft genomes of soft-shell turtle and green sea turtle yield insights into the development and evolution of the turtle-specific body plan.

    PubMed

    Wang, Zhuo; Pascual-Anaya, Juan; Zadissa, Amonida; Li, Wenqi; Niimura, Yoshihito; Huang, Zhiyong; Li, Chunyi; White, Simon; Xiong, Zhiqiang; Fang, Dongming; Wang, Bo; Ming, Yao; Chen, Yan; Zheng, Yuan; Kuraku, Shigehiro; Pignatelli, Miguel; Herrero, Javier; Beal, Kathryn; Nozawa, Masafumi; Li, Qiye; Wang, Juan; Zhang, Hongyan; Yu, Lili; Shigenobu, Shuji; Wang, Junyi; Liu, Jiannan; Flicek, Paul; Searle, Steve; Wang, Jun; Kuratani, Shigeru; Yin, Ye; Aken, Bronwen; Zhang, Guojie; Irie, Naoki

    2013-06-01

    The unique anatomical features of turtles have raised unanswered questions about the origin of their unique body plan. We generated and analyzed draft genomes of the soft-shell turtle (Pelodiscus sinensis) and the green sea turtle (Chelonia mydas); our results indicated the close relationship of the turtles to the bird-crocodilian lineage, from which they split ∼267.9-248.3 million years ago (Upper Permian to Triassic). We also found extensive expansion of olfactory receptor genes in these turtles. Embryonic gene expression analysis identified an hourglass-like divergence of turtle and chicken embryogenesis, with maximal conservation around the vertebrate phylotypic period, rather than at later stages that show the amniote-common pattern. Wnt5a expression was found in the growth zone of the dorsal shell, supporting the possible co-option of limb-associated Wnt signaling in the acquisition of this turtle-specific novelty. Our results suggest that turtle evolution was accompanied by an unexpectedly conservative vertebrate phylotypic period, followed by turtle-specific repatterning of development to yield the novel structure of the shell.

  19. Mesoporous TiO2 Yolk-Shell Microspheres for Dye-sensitized Solar Cells with a High Efficiency Exceeding 11%

    PubMed Central

    Li, Zhao-Qian; Chen, Wang-Chao; Guo, Fu-Ling; Mo, Li-E; Hu, Lin-Hua; Dai, Song-Yuan

    2015-01-01

    Yolk-shell TiO2 microspheres were synthesized via a one-pot template-free solvothermal method building on the aldol condensation reaction of acetylacetone. This unique structure shows superior light scattering ability resulting in power conversion efficiency as high as 11%. This work provided a new synthesis system for TiO2 microspheres from solid to hollow and a novel material platform for high performance solar cells. PMID:26384004

  20. Blended-Wing-Body (BWB) Fuselage Structural Design for Weight Reduction

    NASA Technical Reports Server (NTRS)

    Mukhopadhyay, V.

    2005-01-01

    Structural analysis and design of efficient pressurized fuselage configurations for the advanced Blended-Wing-Body (BWB) flight vehicle is a challenging problem. Unlike a conventional cylindrical pressurized fuselage, stress level in a box type BWB fuselage is an order of magnitude higher, because internal pressure primarily results in bending stress instead of skin-membrane stress. In addition, resulting deformation of aerodynamic surface could significantly affect performance advantages provided by lifting body. The pressurized composite conformal multi-lobe tanks of X-33 type space vehicle also suffered from similar problem. In the earlier BWB design studies, Vaulted Ribbed Shell (VLRS), Flat Ribbed Shell (FRS); Vaulted shell Honeycomb Core (VLHC) and Flat sandwich shell Honeycomb Core (FLHC) concepts were studied. The flat and vaulted ribbed shell concepts were found most efficient. In a recent study, a set of composite sandwich panel and cross-ribbed panel were analyzed. Optimal values of rib and skin thickness, rib spacing, and panel depth were obtained for minimal weight under stress and buckling constraints. In addition, a set of efficient multi-bubble fuselage (MBF) configuration concept was developed. The special geometric configuration of this concept allows for balancing internal cabin pressure load efficiently, through membrane stress in inner-stiffened shell and inter-cabin walls, while the outer-ribbed shell prevents buckling due to external resultant compressive loads. The initial results from these approximate finite element analyses indicate progressively lower maximum stresses and deflections compared to the earlier study. However, a relative comparison of the FEM weight per unit floor area of the segment unit indicates that the unit weights are still relatively higher that the conventional B777 type cylindrical or A380 type elliptic fuselage design. Due to the manufacturing concern associated with multi-bubble fuselage, a Y braced box-type fuselage alternative with special resin-film injected (RFI) stitched carbon composite with foam-core was designed by Boeing under a NASA research contract for the 480 passenger version. It is shown that this configuration can be improved to a modified multi-bubble fuselage which has better stress distribution, for same material and dimension.

  1. On sound transmission into a stiffened cylindrical shell with rings and stringers treated as discrete elements

    NASA Technical Reports Server (NTRS)

    Koval, L. R.

    1980-01-01

    In the context of the transmission of airborne noise into an aircraft fuselage, a mathematical model is presented for the transmission of an oblique plane sound wave into a finite cylindrical shell stiffened by stringers and ring frames. The rings and stringers are modeled as discrete structural elements. The numerical case studied was typical of a narrow-bodied jet transport fuselage. The numerical results show that the ring-frequency dip in the transmission loss curve that is present for a monocoque shell is still present in the case of a stiffened shell. The ring frequency effect is a result of the cylindrical geometry of the shell. Below the ring frequency, stiffening does not appear to have any significant effect on transmission loss, but above the ring frequency, stiffeners can enhance the transmission loss of a cylindrical shell.

  2. Bioluminescent signals spatially amplified by wavelength-specific diffusion through the shell of a marine snail.

    PubMed

    Deheyn, Dimitri D; Wilson, Nerida G

    2011-07-22

    Some living organisms produce visible light (bioluminescence) for intra- or interspecific visual communication. Here, we describe a remarkable bioluminescent adaptation in the marine snail Hinea brasiliana. This species produces a luminous display in response to mechanical stimulation caused by encounters with other motile organisms. The light is produced from discrete areas on the snail's body beneath the snail's shell, and must thus overcome this structural barrier to be viewed by an external receiver. The diffusion and transmission efficiency of the shell is greater than a commercial diffuser reference material. Most strikingly, the shell, although opaque and pigmented, selectively diffuses the blue-green wavelength of the species bioluminescence. This diffusion generates a luminous display that is enlarged relative to the original light source. This unusual shell thus allows spatially amplified outward transmission of light communication signals from the snail, while allowing the animal to remain safely inside its hard protective shell.

  3. Influence of particle size and shell thickness of core-shell packing materials on optimum experimental conditions in preparative chromatography.

    PubMed

    Horváth, Krisztián; Felinger, Attila

    2015-08-14

    The applicability of core-shell phases in preparative separations was studied by a modeling approach. The preparative separations were optimized for two compounds having bi-Langmuir isotherms. The differential mass balance equation of chromatography was solved by the Rouchon algorithm. The results show that as the size of the core increases, larger particles can be used in separations, resulting in higher applicable flow rates, shorter cycle times. Due to the decreasing volume of porous layer, the loadability of the column dropped significantly. As a result, the productivity and economy of the separation decreases. It is shown that if it is possible to optimize the size of stationary phase particles for the given separation task, the use of core-shell phases are not beneficial. The use of core-shell phases proved to be advantageous when the goal is to build preparative column for general purposes (e.g. for purification of different products) in small scale separations. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. 46 CFR 67.3 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., catching, taking, or harvesting fish, shellfish, marine animals, pearls, shells, or marine vegetation in... commit them to use in the building of a vessel. Officer in Charge, Marine Inspection (OCMI) means the...

  5. 46 CFR 67.3 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., catching, taking, or harvesting fish, shellfish, marine animals, pearls, shells, or marine vegetation in... commit them to use in the building of a vessel. Officer in Charge, Marine Inspection (OCMI) means the...

  6. 46 CFR 67.3 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., catching, taking, or harvesting fish, shellfish, marine animals, pearls, shells, or marine vegetation in... commit them to use in the building of a vessel. Officer in Charge, Marine Inspection (OCMI) means the...

  7. Effect of vertebral shell on injection pressure and intravertebral pressure in vertebroplasty.

    PubMed

    Baroud, Gamal; Vant, Christianne; Giannitsios, Demetri; Bohner, Marc; Steffen, Thomas

    2005-01-01

    An experimental biomechanical study conducted on osteoporotic cadaveric vertebrae. 1) To measure the intravertebral shell pressure and injection pressure; and 2) to determine the effect of the vertebral shell on the intravertebral shell pressure and on the injection pressure. Forces that govern cement flow are an essential component of the cement injection process in vertebroplasty. The vertebral shell may play a significant role in confining the flow of cement in the vertebral body and thereby affecting the intravertebral pressure and injection pressure. A small fenestration was created in the left lateral vertebral shell of 14 vertebrae. A valve to open and close the fenestration and a sensor to measure the intravertebral pressure were attached to the opening. A closed fenestration simulated an intact shell, whereas an open fenestration represented a vented shell. Injection pressure and intravertebral pressure at the shell were recorded during a controlled injection. A closed fenestration resulted in a significant increase in the intravertebral pressure at the shell. During the injection, the shell pressure increased on average to approximately 3.54 +/- 2.91 kPa. Conversely, an open fenestration resulted in an instant relaxation of the shell pressure to the ambient pressure of 0 kPa. Additionally, the injection pressure was approximately 97 times higher than the shell pressure. The presence of vertebral shell seems to be important for intravertebral pressure. However, the intravertebral shell pressure adds very little to the injection pressure.

  8. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jaganathen, Y.; Betan, R. M. Id; Michel, N.

    Background: The structure of weakly bound and unbound nuclei close to particle drip lines is one of the major science drivers of nuclear physics. A comprehensive understanding of these systems goes beyond the traditional configuration interaction approach formulated in the Hilbert space of localized states (nuclear shell model) and requires an open quantum system description. The complex-energy Gamow shell model (GSM) provides such a framework as it is capable of describing resonant and nonresonant many-body states on equal footing. Purpose: To make reliable predictions, quality input is needed that allows for the full uncertainty quantification of theoretical results. In thismore » study, we carry out the optimization of an effective GSM (one-body and two-body) interaction in the psdf-shell-model space. The resulting interaction is expected to describe nuclei with 5 ≤ A ≲ 12 at the p-sd-shell interface. Method: The one-body potential of the 4He core is modeled by a Woods-Saxon + spin-orbit + Coulomb potential, and the finite-range nucleon-nucleon interaction between the valence nucleons consists of central, spin-orbit, tensor, and Coulomb terms. The GSM is used to compute key fit observables. The χ 2 optimization is performed using the Gauss-Newton algorithm augmented by the singular value decomposition technique. The resulting covariance matrix enables quantification of statistical errors within the linear regression approach. Results: The optimized one-body potential reproduces nucleon- 4He scattering phase shifts up to an excitation energy of 20 MeV. The two-body interaction built on top of the optimized one-body field is adjusted to the bound and unbound ground-state binding energies and selected excited states of the helium, lithium, and beryllium isotopes up to A = 9 . A very good agreement with experimental results was obtained for binding energies. First applications of the optimized interaction include predictions for two-nucleon correlation densities and excitation spectra of light nuclei with quantified uncertainties. In conclusion: The new interaction will enable comprehensive and fully quantified studies of structure and reactions aspects of nuclei from the psd region of the nuclear chart.« less

  9. The Swimming Ammonite: How Computed Tomography can Address Questions of Functional Morphology

    NASA Astrophysics Data System (ADS)

    Lemanis, Robert; Hoffmann, Rene; Zachow, Stefan

    2014-05-01

    The external shell of the ammonite is a readily recognized and iconic fossil yet the function of this structure remain contested. The shell is divided into the phragmocone, comprised of a series of mostly gas filled chambers separated by septa, and the body chamber where the animal would have resided. Quantitative studies of the functional morphology of the shell have relied on geometric simplifications and mathematical models which limit accuracy and invite controversy. Past work has used simplified models which showed adult ammonites as negatively buoyant and were the basis for arguments of a benthic mode of life for adult ammonites. Many palaeobiologists however argue ammonites lived in the water column, if this is true then the shell must possess neutral/positive buoyancy to allow the animal to live in the water column without expending energy to stay afloat. Using exceptionally preserved hollow ammonite fossils and the shells of modern cephalopods: the external shell of Nautilus pompilius and the internal shell of Spirula spirula, we employ micro-CT, nano-CT and synchrotron x-ray tomography techniques to construct 3D models that are used to evaluate the buoyant properties of the cephalopod phragmocone. This method is applied to the Nautilus to evaluate the accuracy of the method and demonstrates the utility of CT data in volumetric analyses. The phragmocone of a hatchling Spirula seems to be capable of supporting the body in the water column with a single chamber, however difficulties in estimating the volume of the soft body create divergent developments of the buoyant properties through ontogeny. Further investigation of the hatchling ammonite Cadoceras show that it was capable of achieving neutral/positive buoyancy provided the phragmocone possess three or more chambers. Using this technique we are able to reconstruct the ability of the Nautilus and Spirula to maintain a position in the water column by exploiting the buoyancy of the phragmocone. This method has strong potential to address the controversial life-habits of adult ammonites through the study of the buoyant properties of the phragmocone and the structural properties of the shell. The implications for palaeobiology are clear, however the understanding of ammonite life-habits is also important for utilization as archives for palaeoenvironmetal/geochemical data.

  10. Old and New Magic Numbers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Talmi, Igal

    2008-11-11

    The discovery of magic numbers led to the shell model. They indicated closure of major shells and are robust: proton magic numbers are rather independent of the occupation of neutron orbits and vice versa. Recently the magic property became less stringent and we hear a lot about the discovery of new magic numbers. These, however, indicate sub-shell closures and strongly depend on occupation numbers and hence, may be called quasi-magic numbers. Some of these have been known for many years and the mechanism for their appearance as well as disappearance, was well understood within the simple shell model. The situationmore » will be illustrated by a few examples which demonstrate the simple features of the shell model. Will this simplicity emerge from the complex computations of nuclear many-body theory?.« less

  11. Polar wander of an ice shell on Europa

    NASA Technical Reports Server (NTRS)

    Ojakangas, Gregory W.; Stevenson, David J.

    1989-01-01

    The present consideration of a hypothesized ice shell around Europa, which is decoupled from the silicate core by a liquid water layer and possesses a spatially varying thermal equilibrium thickness profile, proceeds through the development of equations for variations in the inertia tensor of a body when second-harmonic-degree topography is added to the crustal base. Attention is given to a realistic model in which the shell and ocean are assumed to undergo reorientations as a single entity independently of the core, but subject to viscous dissipation within the shell. Shell friction is in this case noted to preclude polar wander, unless a low conductivity regolith increases the near-surface temperature by a few tens of degrees C; the ice beneath the regolith would then behave viscously on the time-scale of polar wander.

  12. Passion fruit-like nano-architectures: a general synthesis route

    NASA Astrophysics Data System (ADS)

    Cassano, D.; David, J.; Luin, S.; Voliani, V.

    2017-03-01

    Noble metal nanostructures have demonstrated a number of intriguing features for both medicine and catalysis. However, accumulation issues have prevented their clinical translation, while their use in catalysis has shown serious efficiency and stability hurdles. Here we introduce a simple and robust synthetic protocol for passion fruit-like nano-architectures composed by a silica shell embedding polymeric arrays of ultrasmall noble metal nanoparticles. These nano-architectures show interesting features for both oncology and catalysis. They avoid the issue of persistence in organism thanks to their fast biodegradation in renal clearable building blocks. Furthermore, their calcination results in yolk-shell structures composed by naked metal or alloy nanospheres shielded from aggregation by a silica shell.

  13. PST and PARR: Plan specification tools and a planning and resource reasoning shell for use in satellite mission planning

    NASA Technical Reports Server (NTRS)

    Mclean, David; Yen, Wen

    1989-01-01

    Plan Specification Tools (PST) are tools that allow the user to specify satellite mission plans in terms of satellite activities, relevent orbital events, and targets for observation. The output of these tools is a set of knowledge bases and environmental events which can then be used by a Planning And Resource Reasoning (PARR) shell to build a schedule. PARR is a reactive planning shell which is capable of reasoning about actions in the satellite mission planning domain. Each of the PST tools and PARR are described as well as the use of PARR for scheduling computer usage in the multisatellite operations control center at Goddard Space Flight Center.

  14. Passion fruit-like nano-architectures: a general synthesis route

    PubMed Central

    Cassano, D.; David, J.; Luin, S.; Voliani, V.

    2017-01-01

    Noble metal nanostructures have demonstrated a number of intriguing features for both medicine and catalysis. However, accumulation issues have prevented their clinical translation, while their use in catalysis has shown serious efficiency and stability hurdles. Here we introduce a simple and robust synthetic protocol for passion fruit-like nano-architectures composed by a silica shell embedding polymeric arrays of ultrasmall noble metal nanoparticles. These nano-architectures show interesting features for both oncology and catalysis. They avoid the issue of persistence in organism thanks to their fast biodegradation in renal clearable building blocks. Furthermore, their calcination results in yolk-shell structures composed by naked metal or alloy nanospheres shielded from aggregation by a silica shell. PMID:28256565

  15. Analysis, Design and Optimization of Non-Cylindrical Fuselage for Blended-Wing-Body (BWB) Vehicle

    NASA Technical Reports Server (NTRS)

    Mukhopadhyay, V.; Sobieszczanski-Sobieski, J.; Kosaka, I.; Quinn, G.; Charpentier, C.

    2002-01-01

    Initial results of an investigation towards finding an efficient non-cylindrical fuselage configuration for a conceptual blended-wing-body flight vehicle were presented. A simplified 2-D beam column analysis and optimization was performed first. Then a set of detailed finite element models of deep sandwich panel and ribbed shell construction concepts were analyzed and optimized. Generally these concepts with flat surfaces were found to be structurally inefficient to withstand internal pressure and resultant compressive loads simultaneously. Alternatively, a set of multi-bubble fuselage configuration concepts were developed for balancing internal cabin pressure load efficiently, through membrane stress in inner-stiffened shell and inter-cabin walls. An outer-ribbed shell was designed to prevent buckling due to external resultant compressive loads. Initial results from finite element analysis appear to be promising. These concepts should be developed further to exploit their inherent structurally efficiency.

  16. Health impact assessment in multinationals: A case study of the Royal Dutch/Shell Group

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Birley, Martin

    2005-10-15

    Health impact assessment is part of the risk management process of multinational corporations/companies. Sexually transmitted infections, including HIV/AIDS, and the 'paradox of plenty' are used as examples of the challenges they face. The 'business case' for impact assessment is explained. The policies, procedures, standards, and activities used by Shell to manage such risks are described. An approach to capacity building and competency development is presented that applies to both company staff and external contractors.

  17. Ultrasonic Device Would Open Pipe Bombs

    NASA Technical Reports Server (NTRS)

    El-Raheb, Michael S.; Adams, Marc A.; Zwissler, James G.

    1991-01-01

    Piezoelectric ultrasonic transducer, energized by frequency generator and power supply, vibrates shell of pipe bomb while hardly disturbing explosive inner material. Frequency-control circuitry senses resonance in shell and holds generator at that frequency to induce fatigue cracking in threads of end cap. In addition to disarming bombs, ultrasonically induced fatigue may have other applications. In manufacturing, replaces some machining and cutting operations. In repair of equipment, cleanly and quickly disassembles corroded parts. In demolition of buildings used to dismember steel framework safely and controllably.

  18. Hydrazine Catalyst Production: Sustaining S-405 Technology

    NASA Technical Reports Server (NTRS)

    Wucherer, E. J.; Cook, Timothy; Stiefel, Mark; Humphries, Randy, Jr.; Parker, Janet

    2003-01-01

    The development of the iridium-based Shell 405 catalyst for spontaneous decomposition of hydrazine was one of the key enabling technologies for today's spacecraft and launch vehicles. To ensure that this crucial technology was not lost when Shell elected to exit the business, Aerojet, supported by NASA, has developed a dedicated catalyst production facility that will supply catalyst for future spacecraft and launch vehicle requirements. We have undertaken a program to transfer catalyst production from Shell Chemical USA (Houston, TX) to Aerojet's Redmond, WA location. This technology transition was aided by Aerojet's 30 years of catalyst manufacturing experience and NASA diligence and support in sustaining essential technologies. The facility has produced and tested S-405 catalyst to existing Shell 405 specifications and standards. Our presentation will describe the technology transition effort including development of the manufacturing facility, capture of the manufacturing process, test equipment validation, initial batch build and final testing.

  19. Numerical simulation of deformation and fracture of space protective shell structures from concrete and fiber concrete under pulse loading

    NASA Astrophysics Data System (ADS)

    Radchenko, P. A.; Batuev, S. P.; Radchenko, A. V.; Plevkov, V. S.

    2015-11-01

    This paper presents results of numerical simulation of interaction between aircraft Boeing 747-400 and protective shell of nuclear power plant. The shell is presented as complex multilayered cellular structure comprising layers of concrete and fiber concrete bonded with steel trusses. Numerical simulation was held three-dimensionally using the author's algorithm and software taking into account algorithms for building grids of complex geometric objects and parallel computations. The dynamics of stress-strain state and fracture of structure were studied. Destruction is described using two-stage model that allows taking into account anisotropy of elastic and strength properties of concrete and fiber concrete. It is shown that wave processes initiate destruction of shell cellular structure—cells start to destruct in unloading wave, originating after output of compression wave to the free surfaces of cells.

  20. Comparative study of the shell development of hard- and soft-shelled turtles

    PubMed Central

    Nagashima, Hiroshi; Shibata, Masahiro; Taniguchi, Mari; Ueno, Shintaro; Kamezaki, Naoki; Sato, Noboru

    2014-01-01

    The turtle shell provides a fascinating model for the investigation of the evolutionary modifications of developmental mechanisms. Different conclusions have been put forth for its development, and it is suggested that one of the causes of the disagreement could be the differences in the species of the turtles used – the differences between hard-shelled turtles and soft-shelled turtles. To elucidate the cause of the difference, we compared the turtle shell development in the two groups of turtle. In the dorsal shell development, these two turtle groups shared the gene expression profile that is required for formation, and shared similar spatial organization of the anatomical elements during development. Thus, both turtles formed the dorsal shell through a folding of the lateral body wall, and the Wnt signaling pathway appears to have been involved in the development. The ventral portion of the shell, on the other hand, contains massive dermal bones. Although expression of HNK-1 epitope has suggested that the trunk neural crest contributed to the dermal bones in the hard-shelled turtles, it was not expressed in the initial anlage of the skeletons in either of the types of turtle. Hence, no evidence was found that would support a neural crest origin. PMID:24754673

  1. Comparative study of the shell development of hard- and soft-shelled turtles.

    PubMed

    Nagashima, Hiroshi; Shibata, Masahiro; Taniguchi, Mari; Ueno, Shintaro; Kamezaki, Naoki; Sato, Noboru

    2014-07-01

    The turtle shell provides a fascinating model for the investigation of the evolutionary modifications of developmental mechanisms. Different conclusions have been put forth for its development, and it is suggested that one of the causes of the disagreement could be the differences in the species of the turtles used - the differences between hard-shelled turtles and soft-shelled turtles. To elucidate the cause of the difference, we compared the turtle shell development in the two groups of turtle. In the dorsal shell development, these two turtle groups shared the gene expression profile that is required for formation, and shared similar spatial organization of the anatomical elements during development. Thus, both turtles formed the dorsal shell through a folding of the lateral body wall, and the Wnt signaling pathway appears to have been involved in the development. The ventral portion of the shell, on the other hand, contains massive dermal bones. Although expression of HNK-1 epitope has suggested that the trunk neural crest contributed to the dermal bones in the hard-shelled turtles, it was not expressed in the initial anlage of the skeletons in either of the types of turtle. Hence, no evidence was found that would support a neural crest origin. © 2014 Anatomical Society.

  2. Oceanography: A sea butterfly flaps its wings

    NASA Astrophysics Data System (ADS)

    Ries, Justin B.

    2012-12-01

    Ocean acidification is predicted to harm the ocean's shell-building organisms over the coming centuries. Sea butterflies, an ecologically important group of molluscs in the Arctic and Southern oceans, are already suffering the effects.

  3. Photocopy of drawing. SPACECRAFT INDUSTRIAL AREA, O&C BUILDING, A&T AREA, ...

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

    Photocopy of drawing. SPACECRAFT INDUSTRIAL AREA, O&C BUILDING, A&T AREA, ALTITUDE CHAMBER “L”. NASA, John F. Kennedy Space Center, Florida. Drawing 79K00213, U.S. Army Corps of Engineers, no date. SHELL PENETRATION SCHEDULE. Sheet 4 - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  4. Photocopy of drawing. SPACECRAFT INDUSTRIAL AREA, O&C BUILDING, A&T AREA, ...

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

    Photocopy of drawing. SPACECRAFT INDUSTRIAL AREA, O&C BUILDING, A&T AREA, ALTITUDE CHAMBER “L”. NASA, John F. Kennedy Space Center, Florida. Drawing 79K00213, U.S. Army Corps of Engineers, no date. SHELL PENETRATION LAYOUT. Sheet 3 - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  5. Analysis of nematode mechanics by piezoresistive displacement clamp

    PubMed Central

    Park, Sung-Jin; Goodman, Miriam B.; Pruitt, Beth L.

    2007-01-01

    Studying animal mechanics is critical for understanding how signals in the neuromuscular system give rise to behavior and how force-sensing organs and sensory neurons work. Few techniques exist to provide forces and displacements appropriate for such studies. To address this technological gap, we developed a metrology using piezoresistive cantilevers as force–displacement sensors coupled to a feedback system to apply and maintain defined load profiles to micrometer-scale animals. We show that this system can deliver forces between 10−8 and 10−3 N across distances of up to 100 μm with a resolution of 12 nN between 0.1 Hz and 100 kHz. We use this new metrology to show that force–displacement curves of wild-type nematodes (Caenorhabditis elegans) are linear. Because nematodes have approximately cylindrical bodies, this finding demonstrates that nematode body mechanics can be modeled as a cylindrical shell under pressure. Little is known about the relative importance of hydrostatic pressure and shell mechanics, however. We show that dissipating pressure by cuticle puncture or decreasing it by hyperosmotic shock has only a modest effect on stiffness, whereas defects in the dpy-5 and lon-2 genes, which alter body shape and cuticle proteins, decrease and increase stiffness by 25% and 50%, respectively. This initial analysis of C. elegans body mechanics suggests that shell mechanics dominates stiffness and is a first step in understanding how body mechanics affect locomotion and force sensing. PMID:17962419

  6. Controlled Synthesis and Utilization of Metal and Oxide Hybrid Nanoparticles

    NASA Astrophysics Data System (ADS)

    Crane, Cameron

    This dissertation reports the development of synthetic methods concerning rationally-designed, hybrid, and multifunctional nanomaterials. These methods are based on a wet chemical, solution phase approach that utilizes the knowledge of synthetic organic and inorganic chemistry to generate building blocks in solution for the growth of nanocrystals and hybrid nanostructures. This work builds on the prior knowledge of shape-controlled synthesis of noble metal nanocrystals and expands into the challenging realm of the more reactive first row transition metals. Specifically, a microemulsion sol-gel method was developed to synthesize Au-SiO2 dimers as precursors for the synthesis of segmented heterostructures of noble metals that can be used for catalysis. This microemulsion sol-gel method was modified to synthesize an aqueous suspension of oxidation-resistant Cu-SiO2 core-shell nanoparticles that can be used for sensing and catalysis. A thermal decomposition approach was developed, wherein zero-valence metal precursor complexes in the presence of seed nanoparticles produced metal-metal oxide core-shell structures with well-controlled shell thickness. This method was demonstrated on AuCu 3-Fe3O4, AuCu3-NiO, and AuCu3 -MnO core-shell systems. Switching the core from AuCu3 alloy to pure Cu, this method could extend to Cu-Fe3O4 and Cu-MnO systems. Further etching the Cu core in these core-shell structures led to the formation of the hollow metal oxides which provides a versatile route to hollow nanostructures of metal oxides. This work develops the synthetic library of tools for the production of hybrid nanostructures with multiple functionalities.

  7. Origin and diversity of testate amoebae shell composition: Example of Bullinularia indica living in Sphagnum capillifolium.

    PubMed

    Delaine, Maxence; Bernard, Nadine; Gilbert, Daniel; Recourt, Philippe; Armynot du Châtelet, Eric

    2017-06-01

    Testate amoebae are free-living shelled protists that build a wide range of shells with various sizes, shapes, and compositions. Recent studies showed that xenosomic testate amoebae shells could be indicators of atmospheric particulate matter (PM) deposition. However, no study has yet been conducted to assess the intra-specific mineral, organic, and biologic grain diversity of a single xenosomic species in a natural undisturbed environment. This study aims at providing new information about grain selection to develop the potential use of xenosomic testate amoebae shells as bioindicators of the multiple-origin mineral/organic diversity of their proximal environment. To fulfil these objectives, we analysed the shell content of 38 Bullinularia indica individuals, a single xenosomic testate amoeba species living in Sphagnum capillifolium, by scanning electron microscope (SEM) coupled with X-ray spectroscopy. The shells exhibited high diversities of mineral, organic, and biomineral grains, which confirms their capability to recycle xenosomes. Mineral grain diversity and size of B. indica matched those of the atmospheric natural mineral PM deposited in the peatbog. Calculation of grain size sorting revealed a discrete selection of grains agglutinated by B. indica. These results are a first step towards understanding the mechanisms of particle selection by xenosomic testate amoebae in natural conditions. Copyright © 2017 Elsevier GmbH. All rights reserved.

  8. Scallop-Inspired Shell Engineering of Microparticles for Stable and High Volumetric Capacity Battery Anodes.

    PubMed

    Zhang, Xinghao; Guo, Ruiying; Li, Xianglong; Zhi, Linjie

    2018-06-01

    Building stable and efficient electron and ion transport pathways are critically important for energy storage electrode materials and systems. Herein, a scallop-inspired shell engineering strategy is proposed and demonstrated to confine high volume change silicon microparticles toward the construction of stable and high volumetric capacity binder-free lithium battery anodes. As for each silicon microparticle, the methodology involves an inner sealed but adaptable overlapped graphene shell, and an outer open hollow shell consisting of interconnected reduced graphene oxide, mimicking the scallop structure. The inner closed shell enables simultaneous stabilization of the interfaces of silicon with both carbon and electrolyte, substantially facilitates efficient and rapid transport of both electrons and lithium ions from/to silicon, the outer open hollow shell creates stable and robust transport paths of both electrons and lithium ions throughout the electrode without any sophisticated additives. The resultant self-supported electrode has achieved stable cycling with rapidly increased coulombic efficiency in the early stage, superior rate capability, and remarkably high volumetric capacity upon a facile pressing process. The rational design and engineering of graphene shells of the silicon microparticles developed can provide guidance for the development of a wide range of other high capacity but large volume change electrochemically active materials. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Metal coated colloidosomes as carriers for an antibiotic

    NASA Astrophysics Data System (ADS)

    Sun, Qian; Zhao, Ziyan; Hall, Elizabeth A. H.; Routh, Alexander F.

    2018-06-01

    Colloidosomes are polymer shell microcapsules. They are stable and easy to prepare and have been used to encapsulate drugs for release at specific areas in the body. Traditional polymer shell capsules cannot totally seal drugs, since they are porous and small molecules diffuse through the polymer shell. In this paper, we report a method for encapsulating an antibiotic kanamycin using gold or silver coated colloidosomes. The colloidosomes are impermeable and can be triggered using ultrasound. To investigate the application of the capsules in a biological system, Escherichia Coli (E.coli) was chosen as a model organism. After triggering, the released antibiotic, as well as the metal shell fragments, kill E.coli. Both the silver and gold shells colloidosomes are toxic to this bacterial system and the gold coated colloidosomes can load a higher concentration of kanamycin.

  10. The Acoustical Properties of the Polyurethane Concrete Made of Oyster Shell Waste Comparing Other Concretes as Architectural Design Components

    NASA Astrophysics Data System (ADS)

    Setyowati, Erni; Hardiman, Gagoek; Purwanto

    2018-02-01

    This research aims to determine the acoustical properties of concrete material made of polyurethane and oyster shell waste as both fine aggregate and coarse aggregate comparing to other concrete mortar. Architecture needs aesthetics materials, so the innovation in architectural material should be driven through the efforts of research on materials for building designs. The DOE methods was used by mixing cement, oyster shell, sands, and polyurethane by composition of 160 ml:40 ml:100 ml: 120 ml respectively. Refer to the results of previous research, then cement consumption is reduced up to 20% to keep the concept of green material. This study compared three different compositions of mortars, namely portland cement concrete with gravel (PCG), polyurethane concrete of oyster shell (PCO) and concrete with plastics aggregate (PCP). The methods of acoustical tests were conducted refer to the ASTM E413-04 standard. The research results showed that polyurethane concrete with oyster shell waste aggregate has absorption coefficient 0.52 and STL 63 dB and has a more beautiful appearance when it was pressed into moulding. It can be concluded that polyurethane concrete with oyster shell aggregate (PCO) is well implemented in architectural acoustics-components.

  11. Scrape on Endeavour's robotic arm during oxygen leak repairs

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- A piece of the honeycomb shell around Endeavour's robotic arm has been cut to inspect the arm. A scrape of the shell occurred while work platforms were being installed to gain access to repair the oxygen leak in the Shuttle's mid-body. Launch of Endeavour on mission STS-113 has been postponed until no earlier than Nov. 22.

  12. An intelligent planning and scheduling system for the HST servicing missions

    NASA Technical Reports Server (NTRS)

    Johnson, Jay; Bogovich, Lynn; Tuchman, Alan; Kispert, Andrew; Page, Brenda; Burkhardt, Christian; Littlefield, Ronald; Mclean, David; Potter, William; Ochs, William

    1993-01-01

    A new, intelligent planning and scheduling system has been delivered to NASA-Goddard Space Flight Center (GSFC) to provide support for the up-coming Hubble Space Telescope (HST) Servicing Missions. This new system is the Servicing Mission Planning and Replanning Tool (SM/PART). SM/PART is written in C and runs on a UNlX-based workstation (IBM RS/6000) under Motif. SM/PART effectively automates the complex task of building or rebuilding integrated timelines and command plans which are required by HST Servicing Mission personnel at their consoles during the missions. SM/PART is able to quickly build or rebuild timelines based on information stored in a Knowledge Base (KB) by using an Artificial Intelligence (AI) tool called the Planning And Resource Reasoning (PARR) shell. After a timeline has been built in the batch mode, it can be displayed and edited in an interactive mode with help from the PARR shell. Finally a detailed command plan is generated. The capability to quickly build or rebuild timelines and command plans provides an additional safety factor for the HST, Shuttle and Crew.

  13. The draft genomes of soft–shell turtle and green sea turtle yield insights into the development and evolution of the turtle–specific body plan

    PubMed Central

    Niimura, Yoshihito; Huang, Zhiyong; Li, Chunyi; White, Simon; Xiong, Zhiqiang; Fang, Dongming; Wang, Bo; Ming, Yao; Chen, Yan; Zheng, Yuan; Kuraku, Shigehiro; Pignatelli, Miguel; Herrero, Javier; Beal, Kathryn; Nozawa, Masafumi; Li, Qiye; Wang, Juan; Zhang, Hongyan; Yu, Lili; Shigenobu, Shuji; Wang, Junyi; Liu, Jiannan; Flicek, Paul; Searle, Steve; Wang, Jun; Kuratani, Shigeru; Yin, Ye; Aken, Bronwen; Zhang, Guojie; Irie, Naoki

    2014-01-01

    The unique anatomical features of turtles have raised unanswered questions about the origin of their unique body plan. We generated and analyzed draft genomes of the soft-shell turtle (Pelodiscus sinensis) and the green sea turtle (Chelonia mydas); our results indicated the close relationship of the turtles to the bird-crocodilian lineage, from which they split ~267.9–248.3 million years ago (Upper Permian to Triassic). We also found extensive expansion of olfactory receptor genes in these turtles. Embryonic gene expression analysis identified an hourglass-like divergence of turtle and chicken embryogenesis, with maximal conservation around the vertebrate phylotypic period, rather than at later stages that show the amniote-common pattern. Wnt5a expression was found in the growth zone of the dorsal shell, supporting the possible co-option of limb-associated Wnt signaling in the acquisition of this turtle-specific novelty. Our results suggest that turtle evolution was accompanied by an unexpectedly conservative vertebrate phylotypic period, followed by turtle-specific repatterning of development to yield the novel structure of the shell. PMID:23624526

  14. Fabrication and photoluminescence properties of graphite fiber/ZnO nanorod core-shell structures.

    PubMed

    Liu, Xianbin; Du, Hejun; Liu, Bo; Wang, Jianxiong; Sun, Xiao Wei; Sun, Handong

    2011-08-01

    Graphite fiber/ZnO nanorod core-shell structures were synthesized by thermal evaporation process. The core-shell hybrid architectures were comprised of ZnO nanorods grown on the surface of graphite fiber. In addition, Hollow ZnO hierarchical structure can be obtained by oxidizing the graphite fiber. Room temperature photoluminescence (PL) of the as-made graphite fiber/ZnO nanorod structures shows two UV peaks at around 3.274 eV and 3.181 eV. The temperature-dependent photoluminescence spectra demonstrate the two UV emissions are attributed to the intrinsic optical transitions and extrinsic defect-related emissions in ZnO. These hybrid structures may be used as the building block for fabrication of nanodevices.

  15. Hierarchically assembled theranostic nanostructures for siRNA delivery and imaging applications.

    PubMed

    Shrestha, Ritu; Elsabahy, Mahmoud; Luehmann, Hannah; Samarajeewa, Sandani; Florez-Malaver, Stephanie; Lee, Nam S; Welch, Michael J; Liu, Yongjian; Wooley, Karen L

    2012-10-24

    Dual functional hierarchically assembled nanostructures, with two unique functions of carrying therapeutic cargo electrostatically and maintaining radiolabeled imaging agents covalently within separate component building blocks, have been developed via the supramolecular assembly of several spherical cationic shell cross-linked nanoparticles clustered around a central anionic shell cross-linked cylinder. The shells of the cationic nanoparticles and the hydrophobic core domain of the anionic central cylindrical nanostructure of the assemblies were utilized to complex negatively charged nucleic acids (siRNA) and to undergo radiolabeling, respectively, for potential theranostic applications. The assemblies exhibited exceptional cell transfection and radiolabeling efficiencies, providing an overall advantage over the individual components, which could each facilitate only one or the other of the functions.

  16. A diagnostic expert system for aircraft generator control unit (GCU)

    NASA Astrophysics Data System (ADS)

    Ho, Ting-Long; Bayles, Robert A.; Havlicsek, Bruce L.

    The modular VSCF (variable-speed constant-frequency) generator families are described as using standard modules to reduce the maintenance cost and to improve the product's testability. A general diagnostic expert system shell that guides troubleshooting of modules or line replaceable units (LRUs) is introduced. An application of the diagnostic system to a particular LRU, the generator control unit (GCU) is reported. The approach to building the diagnostic expert system is first to capture general diagnostic strategy in an expert system shell. This shell can be easily applied to different devices or LRUs by writing rules to capture only additional device-specific diagnostic information from expert repair personnel. The diagnostic system has the necessary knowledge embedded in its programs and exhibits expertise to troubleshoot the GCU.

  17. Experiments on shells under base excitation

    NASA Astrophysics Data System (ADS)

    Pellicano, Francesco; Barbieri, Marco; Zippo, Antonio; Strozzi, Matteo

    2016-05-01

    The aim of the present paper is a deep experimental investigation of the nonlinear dynamics of circular cylindrical shells. The specific problem regards the response of circular cylindrical shells subjected to base excitation. The shells are mounted on a shaking table that furnishes a vertical vibration parallel to the cylinder axis; a heavy rigid disk is mounted on the top of the shells. The base vibration induces a rigid body motion, which mainly causes huge inertia forces exerted by the top disk to the shell. In-plane stresses due to the aforementioned inertias give rise to impressively large vibration on the shell. An extremely violent dynamic phenomenon suddenly appears as the excitation frequency varies up and down close to the linear resonant frequency of the first axisymmetric mode. The dynamics are deeply investigated by varying excitation level and frequency. Moreover, in order to generalise the investigation, two different geometries are analysed. The paper furnishes a complete dynamic scenario by means of: (i) amplitude frequency diagrams, (ii) bifurcation diagrams, (iii) time histories and spectra, (iv) phase portraits and Poincaré maps. It is to be stressed that all the results presented here are experimental.

  18. DOE Zero Energy Ready Home Case Study: Transformations, Inc., Production House, Devens, Massachusetts

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    none,

    2013-09-01

    A collaboration with Building America team Building Science Corporation helped this builder win a 2013 Housing Innovation Award in 2013—a 2,508-ft2 home built on speculation in the Devens, MA, subdivision. For the above-grade walls, the super-insulated building shell starts with 12 inch thick double walls composed of two 2x4 16-inch on-center walls spaced 5 inches apart. The space between the walls is filled with low-density (open-cell) spray foam for an insulation value of R-45.

  19. The gastropod shell has been co-opted to kill parasitic nematodes.

    PubMed

    Rae, R

    2017-07-06

    Exoskeletons have evolved 18 times independently over 550 MYA and are essential for the success of the Gastropoda. The gastropod shell shows a vast array of different sizes, shapes and structures, and is made of conchiolin and calcium carbonate, which provides protection from predators and extreme environmental conditions. Here, I report that the gastropod shell has another function and has been co-opted as a defense system to encase and kill parasitic nematodes. Upon infection, cells on the inner layer of the shell adhere to the nematode cuticle, swarm over its body and fuse it to the inside of the shell. Shells of wild Cepaea nemoralis, C. hortensis and Cornu aspersum from around the U.K. are heavily infected with several nematode species including Caenorhabditis elegans. By examining conchology collections I show that nematodes are permanently fixed in shells for hundreds of years and that nematode encapsulation is a pleisomorphic trait, prevalent in both the achatinoid and non-achatinoid clades of the Stylommatophora (and slugs and shelled slugs), which diverged 90-130 MYA. Taken together, these results show that the shell also evolved to kill parasitic nematodes and this is the only example of an exoskeleton that has been co-opted as an immune system.

  20. Altitude Wind Tunnel Drive Motor Installation

    NASA Image and Video Library

    1943-07-21

    Construction workers install the drive motor for the Altitude Wind Tunnel (AWT) in the Exhauster Building at the National Advisory Committee for Aeronautics (NACA) Aircraft Engine Research Laboratory. The AWT was capable of operating full-scale engines in air density, speed, and temperature similar to that found at high altitudes. The tunnel could produce wind speeds up to 500 miles per hour through a 20-foot-diameter test section at the standard operating altitude of 30,000 feet. The airflow was created by a large wooden fan near the tunnel’s southeast corner. This photograph shows the installation of the 18,000-horsepower drive motor inside the adjoining Exhauster Building in July 1943. The General Electric motor, whose support frame is seen in this photograph, connected to a drive shaft that extended from the building, through the tunnel shell, and into a 12-bladed, 31-foot-diameter spruce wood fan. Flexible couplings on the shaft allowed for the movement of the shell. The corner of the Exhauster Building was built around the motor after its installation. The General Electric induction motor could produce 10 to 410 revolutions per minute and create wind speeds up to 500 miles per hour, or Mach 0.63, at 30,000 feet. The AWT became operational in January 1944 and tested piston, turbojet and ramjet engines for nearly 20 years.

  1. Comparative analysis of early ontogeny in Bursatella leachii and Aplysia californica

    PubMed Central

    Vue, Zer; Capo, Thomas R.; Bardales, Ana T.

    2014-01-01

    Opisthobranch molluscs exhibit fascinating body plans associated with the evolution of shell loss in multiple lineages. Sea hares in particular are interesting because Aplysia californica is a well-studied model organism that offers a large suite of genetic tools. Bursatella leachii is a related tropical sea hare that lacks a shell as an adult and therefore lends itself to comparative analysis with A. californica. We have established an enhanced culturing procedure for B. leachii in husbandry that enabled the study of shell formation and loss in this lineage with respect to A. californica life staging. PMID:25538871

  2. Some Implications of Body Build Stereotypes for the Development of Body Concept and Interpersonal Relations.

    ERIC Educational Resources Information Center

    Lerner, Richard M.

    In this paper the author tries to indicate, through a review of his research, that the scope of the study of body build stereotypes has been broadened to address the larger issues involved in assessing some of the implications of body build stereotypes for the development of body concept and interpersonal relations. Among the topics discussed are:…

  3. KSC-02pd1741

    NASA Image and Video Library

    2002-11-15

    KENNEDY SPACE CENTER, FLA. -- An ultrasound device is held at the site where the honeycomb shell around Endeavour's robotic arm has been cut to inspect the arm. A scrape of the shell occurred while work platforms were being installed to gain access to repair the oxygen leak in the Shuttle's mid-body. Launch of Endeavour on mission STS-113 has been postponed until no earlier than Nov. 22.

  4. Superficial shell insulation in resting and exercising men in cold water.

    PubMed

    Veicsteinas, A; Ferretti, G; Rennie, D W

    1982-06-01

    From measurements of subcutaneous fat temperature (Tsf) at known depths below the surface, skin surface temperature (Tsk), and direct skin heat flux (H), the superficial shell isulation (Iss) of the thigh (fat + skin) was calculated as Iss (degrees C.m2.w-1) = (Tsf - Tsk)/H in nine male subjects immersed head out in a well-stirred water bath. Also, at critical water temperature (CWT = 28-33 degrees C), eight of the subjects rested for 3 h, enabling overall maximal tissue insulation (It,max) to be calculated as It,max (degrees C.m2.W-1) = (Tre - Tw)/(0.92 M +/- delta S), where Tre is rectal temperature, Tw is water temperature, M is metabolic rate, and s is loss or gain of body heat. Five subjects performed up to 2 h of mild leg cycling, preceded and followed by 60 min of rest, and both thigh Iss and overall It were measured during exercise. Iss increased from minimal values in Tw greater than 33 degrees C to maximal values (Iss,max) at CWT or below. Iss,max was linearly related to tissue thickness (d) in millimeters of fat plus skin, Iss,max (degrees C.m2.W-1) = 0.0048d-0.0052; r = 0.95, n = 37, and was not influenced by leg exercise up to a metabolic rate of 150 W.m-2 in CWT despite large increases in Tsf and H and large decreases in overall It. The slope of Iss,max vs. depth, 0.0048 degrees C.m2.W-1.mm-1, is almost identical to thermal resistivity of fat in vitro, suggesting that the superficial shell is unperfused in CWT at rest or during mild exercise. When maximal superficial shell insulation (It,ss,max) for the whole body was calculated with allowance for differing fat thicknesses and surface areas of body regions, it could account for only 10-15% of overall It,max at rest and 35-40% of overall It in mild exercise. We suggest that the poorly perfused muscle shell plays a more important role as a defense against cooling at CWT than does the superficial shell (fat + skin), particularly at rest.

  5. Baculite 3D Modeling: a New Method for Computing Buoyancy, Stability, and Orientation with Implications for Ectocochleate Cephalopod Hydrostatics

    NASA Astrophysics Data System (ADS)

    Peterman, D. J.; Barton, C. C.

    2017-12-01

    Ectocochleate (external) cephalopod shells are comprised of a body chamber which houses the organism's soft parts and the phragmocone which consists of a series of progressively larger chambers (camerae) divided by septa. The phragmocone is used as a passive gas float for buoyancy regulation. The soft body and the mineralized shell are denser than water and are negatively buoyant while the phragmocone is positively buoyant due to some fraction of gas in its chambers. This provides a neutrally buoyant condition when the total mass of the organism is equal to the mass of the displaced water. The static orientation of the organism occurs when the centers of buoyancy and mass are vertically aligned and stability is determined by their degree of separation. Three-dimensional modeling of a specimen of Baculites compressus (which has a straight conical shell) was performed using Autodesk Meshmixer, Netfabb ®, Blender 2.78, and MeshLab. The initial 3D mesh shapefile was created by Autodesk ReCap 360™ photogrammetry software. The specimen requirements for the models include: an external shell (ideally complete, otherwise approximated), a septum showing lower order frilling, and a suture pattern to reconstruct the higher order septal frilling (for complex septa). Volumes and centers of mass/buoyancy were calculated with MeshLab in order to determine neutrality, stability, and orientation. Our method can be used to investigate the influence of morphological features on these hydrostatic properties of ectocochleate cephalopods and also the paleoecological implications of different morphotypes. Baculites compressus, is found to assume relatively stable vertical orientations when the shell is positively or neutrally buoyant. By arbitrarily flooding all chambers, the ammonite becomes negatively buoyant, and the centers of buoyancy and mass virtually coincide. This reduces stability but allows the living ammonite to assume a larger range of orientations, including horizontal, possibly by the active use of its hyponome (funnel used for jet propulsion). The geometry of the shell and amount of cameral gas, relative to the soft body and cameral liquid, have the greatest influence on the hydrostatic properties of ectocochleate cephalopods due to their large differences in density relative to that of seawater.

  6. Hybrid Wing-Body Pressurized Fuselage and Bulkhead, Design and Optimization

    NASA Technical Reports Server (NTRS)

    Mukhopadhyay, Vivek

    2013-01-01

    The structural weight reduction of a pressurized Hybrid Wing-Body (HWB) fuselage is a serious challenge. Hence, research and development are presently being continued at NASA under the Environmentally Responsible Aviation (ERA) and Subsonic Fixed Wing (SFW) projects in collaboration with the Boeing Company, Huntington Beach and Air Force Research Laboratory (AFRL). In this paper, a structural analysis of the HWB fuselage and bulkhead panels is presented, with the objectives of design improvement and structural weight reduction. First, orthotropic plate theories for sizing, and equivalent plate analysis with appropriate simplification are considered. Then parametric finite-element analysis of a fuselage section and bulkhead are conducted using advanced stitched composite structural concepts, which are presently being developed at Boeing for pressurized HWB flight vehicles. With this advanced stiffened-shell design, structural weights are computed and compared to the thick sandwich, vaulted-ribbed-shell, and multi-bubble stiffened-shell structural concepts that had been studied previously. The analytical and numerical results are discussed to assess the overall weight/strength advantages.

  7. C++ Planning and Resource Reasoning (PARR) shell

    NASA Technical Reports Server (NTRS)

    Mcintyre, James; Tuchman, Alan; Mclean, David; Littlefield, Ronald

    1994-01-01

    This paper describes a generic, C++ version of the Planning and Resource Reasoning (PARR) shell which has been developed to supersede the C-based versions of PARR that are currently used to support AI planning and scheduling applications in flight operations centers at Goddard Space Flight Center. This new object-oriented version of PARR can be more easily customized to build a variety of planning and scheduling applications, and C++ PARR applications can be more easily ported to different environments. Genetic classes, constraints, strategies, and paradigms are described along with two types of PARR interfaces.

  8. On the viability of exploiting L-shell fluorescence for X-ray polarimetry

    NASA Technical Reports Server (NTRS)

    Weisskopf, M. C.; Sutherland, P. G.; Elsner, R. F.; Ramsey, B. D.

    1985-01-01

    It has been suggested that one may build an X-ray polarimeter by exploiting the polarization dependence of the angular distribution of L-shell fluorescence photons. In this paper the sensitivity of this approach to polarimetry is examined theoretically. The calculations are applied to several detection schemes using imaging proportional counters that would have direct application in X-ray astronomy. It is found, however, that the sensitivity of this method for measuring X-ray polarization is too low to be of use for other than laboratory applications.

  9. Improving X-ray Optics Through Differential Deposition

    NASA Technical Reports Server (NTRS)

    Ramsey, Brian; Kilaru, Kiranmayee; Atkins, Carolyn; Gubarev, Mikhail V.; Gaskin, Jessica A.; O'Dell, Steve; Weisskopf, Martin; Zhang, William; Romaine, Suzanne

    2012-01-01

    The differential deposition technique can in theory correct shell figures to approximate arcsecond value. We have received APRA funding and are building two custom system to demonstrate the technique on full shell and segmented optics. We hope to be able to demonstrate < 5 arcsec performance in < 2 years. To go beyond this, (arcsecond level) is very difficult to judge as we have not yet discovered the problems. May necessitate in-situ metrology, stress reduction investigations, correcting for gravity effects, correcting for temperature effects. Some of this will become obvious in early parts of the investigation.

  10. Differences in Body Build in Children of Different Ethnic Groups and their Impact on the Prevalence of Stunting, Thinness, Overweight, and Obesity.

    PubMed

    Poh, Bee Koon; Wong, Jyh Eiin; Norimah, A Karim; Deurenberg, Paul

    2016-03-01

    The prevalence of stunting, thinness, overweight, and obesity among children differs by ethnicity. It is not known whether differences in body build across the ethnic groups influence the interpretation of nutritional parameters. To explore the differences in body build across the 5 main ethnic groups in Malaysia and to determine whether differences in body build have an impact on the interpretation of nutrition indicators. A total of 3227 children aged 2.0 to 12.9 years who participated in the South East Asian Nutrition Surveys (SEANUTS) in Malaysia were included in this analysis. Body weight, height, sitting height, wrist and knee breadths, and biceps and subscapular skinfolds were measured, and relative leg length, slenderness index, and sum of skinfolds were calculated. Z scores for height-for-age (HAZ) and body mass index-for-age (BAZ) were calculated using the World Health Organization (WHO) 2007 growth standards. Differences in relative leg length and slenderness across the ethnic groups were correlated with HAZ and BAZ. Correction for differences in body build did, in some ethnic groups, have significant impact on the prevalence of stunting, thinness, overweight, and obesity, and the pattern of prevalence across ethnic groups changed. At the population level, corrections for body build had only minor and mostly nonsignificant effects on prevalence, but at an individual level, corrections for body build placed a substantial number of children in different height or weight categories. Whether these misclassifications warrant additional assessment of body build in clinical practice will need further investigation. © The Author(s) 2016.

  11. A Complete Structural Inventory of the Mycobacterial Microcompartment Shell Proteins Constrains Models of Global Architecture and Transport*

    PubMed Central

    Mallette, Evan

    2017-01-01

    Bacterial microcompartments are bacterial analogs of eukaryotic organelles in that they spatially segregate aspects of cellular metabolism, but they do so by building not a lipid membrane but a thin polyhedral protein shell. Although multiple shell protein structures are known for several microcompartment types, additional uncharacterized components complicate systematic investigations of shell architecture. We report here the structures of all four proteins proposed to form the shell of an uncharacterized microcompartment designated the Rhodococcus and Mycobacterium microcompartment (RMM), which, along with crystal interactions and docking studies, suggests possible models for the particle's vertex and edge organization. MSM0272 is a typical hexameric β-sandwich shell protein thought to form the bulk of the facet. MSM0273 is a pentameric β-barrel shell protein that likely plugs the vertex of the particle. MSM0271 is an unusual double-ringed bacterial microcompartment shell protein whose rings are organized in an offset position relative to all known related proteins. MSM0275 is related to MSM0271 but self-organizes as linear strips that may line the facet edge; here, the presence of a novel extendable loop may help ameliorate poor packing geometry of the rigid main particle at the angled edges. In contrast to previously characterized homologs, both of these proteins show closed pores at both ends. This suggests a model where key interactions at the vertex and edges are mediated at the inner layer of the shell by MSM0271 (encircling MSM0273) and MSM0275, and the facet is built from MSM0272 hexamers tiling in the outer layer of the shell. PMID:27927988

  12. A Complete Structural Inventory of the Mycobacterial Microcompartment Shell Proteins Constrains Models of Global Architecture and Transport.

    PubMed

    Mallette, Evan; Kimber, Matthew S

    2017-01-27

    Bacterial microcompartments are bacterial analogs of eukaryotic organelles in that they spatially segregate aspects of cellular metabolism, but they do so by building not a lipid membrane but a thin polyhedral protein shell. Although multiple shell protein structures are known for several microcompartment types, additional uncharacterized components complicate systematic investigations of shell architecture. We report here the structures of all four proteins proposed to form the shell of an uncharacterized microcompartment designated the Rhodococcus and Mycobacterium microcompartment (RMM), which, along with crystal interactions and docking studies, suggests possible models for the particle's vertex and edge organization. MSM0272 is a typical hexameric β-sandwich shell protein thought to form the bulk of the facet. MSM0273 is a pentameric β-barrel shell protein that likely plugs the vertex of the particle. MSM0271 is an unusual double-ringed bacterial microcompartment shell protein whose rings are organized in an offset position relative to all known related proteins. MSM0275 is related to MSM0271 but self-organizes as linear strips that may line the facet edge; here, the presence of a novel extendable loop may help ameliorate poor packing geometry of the rigid main particle at the angled edges. In contrast to previously characterized homologs, both of these proteins show closed pores at both ends. This suggests a model where key interactions at the vertex and edges are mediated at the inner layer of the shell by MSM0271 (encircling MSM0273) and MSM0275, and the facet is built from MSM0272 hexamers tiling in the outer layer of the shell. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  13. Controlled Formation of Radial Core-Shell Si/Metal Silicide Crystalline Heterostructures.

    PubMed

    Kosloff, Alon; Granot, Eran; Barkay, Zahava; Patolsky, Fernando

    2018-01-10

    The highly controlled formation of "radial" silicon/NiSi  core-shell nanowire heterostructures has been demonstrated for the first time. Here, we investigated the "radial" diffusion of nickel atoms into crystalline nanoscale silicon pillar 11 cores, followed by nickel silicide phase formation and the creation of a well-defined shell structure. The described approach is based on a two-step thermal process, which involves metal diffusion at low temperatures in the range of 200-400 °C, followed by a thermal curing step at a higher temperature of 400 °C. In-depth crystallographic analysis was performed by nanosectioning the resulting silicide-shelled silicon nanopillar heterostructures, giving us the ability to study in detail the newly formed silicide shells. Remarkably, it was observed that the resulting silicide shell thickness has a self-limiting behavior, and can be tightly controlled by the modulation of the initial diffusion-step temperature. In addition, electrical measurements of the core-shell structures revealed that the resulting shells can serve as an embedded conductive layer in future optoelectronic applications. This research provides a broad insight into the Ni silicide "radial" diffusion process at the nanoscale regime, and offers a simple approach to form thickness-controlled metal silicide shells in the range of 5-100 nm around semiconductor nanowire core structures, regardless the diameter of the nanowire cores. These high quality Si/NiSi core-shell nanowire structures will be applied in the near future as building blocks for the creation of utrathin highly conductive optically transparent top electrodes, over vertical nanopillars-based solar cell devices, which may subsequently lead to significant performance improvements of these devices in terms of charge collection and reduced recombination.

  14. Valve assembly for use with high temperature and high pressure fluids

    DOEpatents

    De Feo, Angelo

    1982-01-01

    The valve assembly for use with high temperature and high pressure fluids has inner and outer spaced shells and a valve actuator support of inner and outer spaced members which are connected at their end portions to the inner and outer shells, respectively, to extend substantially normal to the longitudinal axis of the inner shell. A layer of resilient heat insulating material covers the outer surfaces of the inner shell and the inner actuator support member and is of a thickness to only occupy part of the spaces between the inner and outer shells and inner and outer actuator support members. The remaining portion of the space between the inner and outer shells and the space between the inner and outer members is substantially filled with a body of castable, rigid refractory material. A movable valve member is disposed in the inner shell. A valve actuator assembly is supported in the valve actuator support to extend into the inner shell for connection with the movable valve member for movement of the movable valve member to positions from a fully open to a fully closed position to control flow of fluid through the inner shell. An anchor mneans is disposed adjacent opposite sides of the axis of the valve actuator support and attached to the inner shell so that relative radial movement between the inner and outer shell is permitted by the layer of resilient heat insulating material and relative longitudinal movement of the inner shell to the outer shell is permitted in opposite directions from the anchor means to thereby maintain the functional integrity of the movable valve member by providing an area of the inner shell surrounding the movable valve member longitdinally stationary, but at the same time allowing radial movement.

  15. Ocean Warming, More than Acidification, Reduces Shell Strength in a Commercial Shellfish Species during Food Limitation

    PubMed Central

    Mackenzie, Clara L.; Ormondroyd, Graham A.; Curling, Simon F.; Ball, Richard J.; Whiteley, Nia M.; Malham, Shelagh K.

    2014-01-01

    Ocean surface pH levels are predicted to fall by 0.3–0.4 pH units by the end of the century and are likely to coincide with an increase in sea surface temperature of 2–4°C. The combined effect of ocean acidification and warming on the functional properties of bivalve shells is largely unknown and of growing concern as the shell provides protection from mechanical and environmental challenges. We examined the effects of near-future pH (ambient pH –0.4 pH units) and warming (ambient temperature +4°C) on the shells of the commercially important bivalve, Mytilus edulis when fed for a limited period (4–6 h day−1). After six months exposure, warming, but not acidification, significantly reduced shell strength determined as reductions in the maximum load endured by the shells. However, acidification resulted in a reduction in shell flex before failure. Reductions in shell strength with warming could not be explained by alterations in morphology, or shell composition but were accompanied by reductions in shell surface area, and by a fall in whole-body condition index. It appears that warming has an indirect effect on shell strength by re-allocating energy from shell formation to support temperature-related increases in maintenance costs, especially as food supply was limited and the mussels were probably relying on internal energy reserves. The maintenance of shell strength despite seawater acidification suggests that biomineralisation processes are unaffected by the associated changes in CaCO3 saturation levels. We conclude that under near-future climate change conditions, ocean warming will pose a greater risk to shell integrity in M. edulis than ocean acidification when food availability is limited. PMID:24489785

  16. Ocean warming, more than acidification, reduces shell strength in a commercial shellfish species during food limitation.

    PubMed

    Mackenzie, Clara L; Ormondroyd, Graham A; Curling, Simon F; Ball, Richard J; Whiteley, Nia M; Malham, Shelagh K

    2014-01-01

    Ocean surface pH levels are predicted to fall by 0.3-0.4 pH units by the end of the century and are likely to coincide with an increase in sea surface temperature of 2-4 °C. The combined effect of ocean acidification and warming on the functional properties of bivalve shells is largely unknown and of growing concern as the shell provides protection from mechanical and environmental challenges. We examined the effects of near-future pH (ambient pH -0.4 pH units) and warming (ambient temperature +4 °C) on the shells of the commercially important bivalve, Mytilus edulis when fed for a limited period (4-6 h day(-1)). After six months exposure, warming, but not acidification, significantly reduced shell strength determined as reductions in the maximum load endured by the shells. However, acidification resulted in a reduction in shell flex before failure. Reductions in shell strength with warming could not be explained by alterations in morphology, or shell composition but were accompanied by reductions in shell surface area, and by a fall in whole-body condition index. It appears that warming has an indirect effect on shell strength by re-allocating energy from shell formation to support temperature-related increases in maintenance costs, especially as food supply was limited and the mussels were probably relying on internal energy reserves. The maintenance of shell strength despite seawater acidification suggests that biomineralisation processes are unaffected by the associated changes in CaCO3 saturation levels. We conclude that under near-future climate change conditions, ocean warming will pose a greater risk to shell integrity in M. edulis than ocean acidification when food availability is limited.

  17. Body build classes as a method for systematization of age-related anthropometric changes in girls aged 7-8 and 17-18 years.

    PubMed

    Kasmel, Jaan; Kaarma, Helje; Koskel, Säde; Tiit, Ene-Margit

    2004-03-01

    A total of 462 schoolgirls aged 7-8 and 17-18 years were examined anthropometrically (45 body measurements and 10 skinfolds) in a cross-sectional study. The data were processed in two age groups: 7-8-year-olds (n = 205) and 17-18-year-olds (n = 257). Relying on average height and weight in the groups, both groups were divided into five body build classes: small, medium, large, pyknomorphous and leptomorphous. In these classes, the differences in all other body measurements were compared, and in both age groups, analogous systematic differences were found in length, width and depth measurements and circumferences. This enabled us to compare proportional changes in body measurements during ten years, using for this ratios of averages of basic measurements and measurement groups in the same body build classes. Statistical analysis by the sign test revealed statistically significant differences between various body build classes in the growth of averages. Girls belonging to the small class differed from the girls of the large class by an essentially greater increase in their measurements. Our results suggest that the growth rate of body measurements of girls with different body build can be studied by the help of body build classification.

  18. External and internal shell formation in the ramshorn snail Marisa cornuarietis are extremes in a continuum of gradual variation in development

    PubMed Central

    2013-01-01

    Background Toxic substances like heavy metals can inhibit and disrupt the normal embryonic development of organisms. Exposure to platinum during embryogenesis has been shown to lead to a “one fell swoop” internalization of the shell in the ramshorn snail Marisa cornuarietis, an event which has been discussed to be possibly indicative of processes in evolution which may result in dramatic changes in body plans. Results Whereas at usual cultivation temperature, 26°C, platinum inhibits the growth of both shell gland and mantle edge during embryogenesis leading to an internalization of the mantle and, thus, also of the shell, higher temperatures induce a re-start of the differential growth of the mantle edge and the shell gland after a period of inactivity. Here, developing embryos exhibit a broad spectrum of shell forms: in some individuals only the ventral part of the visceral sac is covered while others develop almost “normal” shells. Histological studies and scanning electron microscopy images revealed platinum to inhibit the differential growth of the shell gland and the mantle edge, and elevated temperature (28 - 30°C) to mitigate this platinum effect with varying efficiency. Conclusion We could show that the formation of internal, external, and intermediate shells is realized within the continuum of a developmental gradient defined by the degree of differential growth of the embryonic mantle edge and shell gland. The artificially induced internal and intermediate shells are first external and then partly internalized, similar to internal shells found in other molluscan groups. PMID:23682742

  19. Radar attenuation in Europa's ice shell: Obstacles and opportunities for constraining the shell thickness and its thermal structure

    NASA Astrophysics Data System (ADS)

    Kalousová, Klára; Schroeder, Dustin M.; Soderlund, Krista M.

    2017-03-01

    Young surface and possible recent endogenic activity make Europa one of the most exciting solar system bodies and a primary target for spacecraft exploration. Future Europa missions are expected to carry ice-penetrating radar instruments designed to investigate its subsurface thermophysical structure. Several authors have addressed the radar sounders' performance at icy moons, often ignoring the complex structure of a realistic ice shell. Here we explore the variation in two-way radar attenuation for a variety of potential thermal structures of Europa's shell (determined by reference viscosity, activation energy, tidal heating, surface temperature, and shell thickness) as well as for low and high loss temperature-dependent attenuation model. We found that (i) for all investigated ice shell thicknesses (5-30 km), the radar sounder will penetrate between 15% and 100% of the total thickness, (ii) the maximum penetration depth varies laterally, with deepest penetration possible through cold downwellings, (iii) direct ocean detection might be possible for shells of up to 15 km thick if the signal travels through cold downwelling ice or the shell is conductive, (iv) even if the ice/ocean interface is not directly detected, penetration through most of the shell could constrain the deep shell structure through returns from deep non-ocean interfaces or the loss of signal itself, and (v) for all plausible ice shells, the two-way attenuation to the eutectic point is ≲30 dB which shows a robust potential for longitudinal investigation of the ice shell's shallow thermophysical structure.

  20. Program Analysis and Design Requirements for tne National Science Center

    DTIC Science & Technology

    1991-02-01

    shell of an old exposition building with secondhand furniture to display exhibit items, to the Ontario Science Center, which is a more modem building...Storage Area Pigeonhole storage cabinets for children’s school books , coats, and boots are provided at the Indianapolis Center. The Ontario center...used shopping carts for school groups to store their coats and books . They do not work well according to center staff and are cumbersome and unsightly

  1. Charge carrier dynamics investigation of CuInS2 quantum dots films using injected charge extraction by linearly increasing voltage (i-CELIV): the role of ZnS Shell

    NASA Astrophysics Data System (ADS)

    Bi, Ke; Sui, Ning; Zhang, Liquan; Wang, Yinghui; Liu, Qinghui; Tan, Mingrui; Zhou, Qiang; Zhang, Hanzhuang

    2016-12-01

    The role of ZnS shell on the photo-physical properties within CuInS2/ZnS quantum dots (QDs) is carefully studied in optoelectronic devices. Linearly increasing voltage technique has been employed to investigate the charge carrier dynamics of both CuInS2 and CuInS2/ZnS QDs films. This study shows that charge carriers follow a similar behavior of monomolecular recombination in this film, with their charge transfer rate correlates to the increase of applied voltage. It turns out that the ZnS shell could affect the carrier diffusion process through depressing the trapping states and would build up a potential barrier.

  2. Coaxial metal-oxide-semiconductor (MOS) Au/Ga2O3/GaN nanowires.

    PubMed

    Hsieh, Chin-Hua; Chang, Mu-Tung; Chien, Yu-Jen; Chou, Li-Jen; Chen, Lih-Juann; Chen, Chii-Dong

    2008-10-01

    Coaxial metal-oxide-semiconductor (MOS) Au-Ga2O3-GaN heterostructure nanowires were successfully fabricated by an in situ two-step process. The Au-Ga2O3 core-shell nanowires were first synthesized by the reaction of Ga powder, a mediated Au thin layer, and a SiO2 substrate at 800 degrees C. Subsequently, these core-shell nanowires were nitridized in ambient ammonia to form a GaN coating layer at 600 degrees C. The GaN shell is a single crystal, an atomic flat interface between the oxide and semiconductor that ensures that the high quality of the MOS device is achieved. These novel 1D nitride-based MOS nanowires may have promise as building blocks to the future nitride-based vertical nanodevices.

  3. Three-Dimensional Solution of the Free Vibration Problem for Metal-Ceramic Shells Using the Method of Sampling Surfaces

    NASA Astrophysics Data System (ADS)

    Kulikov, G. M.; Plotnikova, S. V.

    2017-03-01

    The possibility of using the method of sampling surfaces (SaS) for solving the free vibration problem of threedimensional elasticity for metal-ceramic shells is studied. According to this method, in the shell body, an arbitrary number of SaS parallel to its middle surface are selected in order to take displacements of these surfaces as unknowns. The SaS pass through the nodes of a Chebyshev polynomial, which improves the convergence of the SaS method significantly. As a result, the SaS method can be used to obtain analytical solutions of the vibration problem for metal-ceramic plates and cylindrical shells that asymptotically approach the exact solutions of elasticity as the number of SaS tends to infinity.

  4. Dynamic model of open shell structures buried in poroelastic soils

    NASA Astrophysics Data System (ADS)

    Bordón, J. D. R.; Aznárez, J. J.; Maeso, O.

    2017-08-01

    This paper is concerned with a three-dimensional time harmonic model of open shell structures buried in poroelastic soils. It combines the dual boundary element method (DBEM) for treating the soil and shell finite elements for modelling the structure, leading to a simple and efficient representation of buried open shell structures. A new fully regularised hypersingular boundary integral equation (HBIE) has been developed to this aim, which is then used to build the pair of dual BIEs necessary to formulate the DBEM for Biot poroelasticity. The new regularised HBIE is validated against a problem with analytical solution. The model is used in a wave diffraction problem in order to show its effectiveness. It offers excellent agreement for length to thickness ratios greater than 10, and relatively coarse meshes. The model is also applied to the calculation of impedances of bucket foundations. It is found that all impedances except the torsional one depend considerably on hydraulic conductivity within the typical frequency range of interest of offshore wind turbines.

  5. Research on soundproof properties of cylindrical shells of generalized phononic crystals

    NASA Astrophysics Data System (ADS)

    Liu, Ru; Shu, Haisheng; Wang, Xingguo

    2017-04-01

    Based on the previous studies, the concept of generalized phononic crystals (GPCs) is further introduced into the cylindrical shell structures in this paper. And a type of cylindrical shells of generalized phononic crystals (CS-GPCs) is constructed, the structural field and acoustic-structural coupled field of the composite cylindrical shells are examined respectively. For the structural field, the transfer matrix method of mechanical state vector is adopted to build the transfer matrix of radial waves propagating from inside to outside. For the acoustic-structural coupled field, the expressions of the acoustic transmission/reflection coefficients and the sound insulation of acoustic waves with the excitation of center line sound source are set up. And the acoustic transmission coefficient and the frequency response of sound insulation in this mode were numerical calculated. Furthermore, the theoretical analysis results are verified by using the method of combining the numerical calculation and finite element simulation. Finally, the effects of inner and outer fluid parameters on the transmission/reflection coefficients of CS-GPCs are analyzed in detail.

  6. Dynamics of a suspension of interacting yolk-shell particles

    DOE PAGES

    Sánchez Díaz, L. E.; Cortes-Morales, E. C.; Li, X.; ...

    2014-12-01

    In this work we study the self-diusion properties of a liquid of hollow spherical particles (shells) bearing a smaller solid sphere in their interior (yolks). We model this system using purely repulsive hard-body interactions between all (shell and yolk) particles, but assume the presence of a background ideal solvent such that all the particles execute free Brownian motion between collisions, characterized by short-time self-diusion coecients D0 s for the shells and D0 y for the yolks. Using a softened version of these interparticle potentials we perform Brownian dynamics simulations to determine the mean squared displacement and intermediate scattering function ofmore » the yolk-shell complex. These results can be understood in terms of a set of eective Langevin equations for the N interacting shell particles, pre-averaged over the yolks' degrees of freedom, from which an approximate self-consistent description of the simulated self-diusion properties can be derived. Here we compare the theoretical and simulated results between them, and with the results for the same system in the absence of yolks. We nd that the yolks, which have no eect on the shell-shell static structure, in uence the dynamic properties in a predictable manner, fully captured by the theory.« less

  7. Combustion in the Wake as a Means of Body-Drag Reduction as Determined from Free-Flight Tests of 40-Millimeter Shells

    NASA Technical Reports Server (NTRS)

    Welsh, Clement J.

    1952-01-01

    The results of free-flight drag tests of 40-millimeter shells conducted by the National Advisory Committee for Aeronautics for the Ballistic Research Laboratories, Ordnance Department, U. S. Army, are presented. A drag reduction at supersonic speeds of approximately 20 percent of the projectile's drag was obtained by combustion in the wake of the projectile in flight.

  8. Scrape on Endeavour's robotic arm during oxygen leak repairs

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- An ultrasound device is held at the site where the honeycomb shell around Endeavour's robotic arm has been cut to inspect the arm. A scrape of the shell occurred while work platforms were being installed to gain access to repair the oxygen leak in the Shuttle's mid-body. Launch of Endeavour on mission STS-113 has been postponed until no earlier than Nov. 22.

  9. Scrape on Endeavour's robotic arm during oxygen leak repairs

    NASA Technical Reports Server (NTRS)

    2002-01-01

    KENNEDY SPACE CENTER, FLA. -- The opening shown here is the site where the honeycomb shell around Endeavour's robotic arm has been cut to inspect the arm. A scrape of the shell occurred while work platforms were being installed to gain access to repair the oxygen leak in the Shuttle's mid-body. Launch of Endeavour on mission STS-113 has been postponed until no earlier than Nov. 22.

  10. 49 CFR 178.358-2 - Materials of construction and other requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... any joint in the shell. (e) Vent holes 5 mm (0.2-inch) diameter must be drilled in the outer shell to... Society Codes B-3.0 and D-1.0 (IBR, see § 171.7 of this subchapter). Body seams and joints for the liner... 14 cm (5.5-inch) minimum thickness of foam must be provided over the entire liner except where: (1...

  11. Approximate method for calculating a thickwalled cylinder with rigidly clamped ends

    NASA Astrophysics Data System (ADS)

    Andreev, Vladimir

    2018-03-01

    Numerous papers dealing with the calculations of cylindrical bodies [1 -8 and others] have shown that analytic and numerical-analytical solutions in both homogeneous and inhomogeneous thick-walled shells can be obtained quite simply, using expansions in Fourier series on trigonometric functions, if the ends are hinged movable (sliding support). It is much more difficult to solve the problem of calculating shells with builtin ends.

  12. Simulation and analysis of light scattering by multilamellar bodies present in the human eye

    PubMed Central

    Méndez-Aguilar, Emilia M.; Kelly-Pérez, Ismael; Berriel-Valdos, L. R.; Delgado-Atencio, José A.

    2017-01-01

    A modified computational model of the human eye was used to obtain and compare different probability density functions, radial profiles of light pattern distributions, and images of the point spread function formed in the human retina under the presence of different kinds of particles inside crystalline lenses suffering from cataracts. Specifically, this work uses simple particles without shells and multilamellar bodies (MLBs) with shells. The emergence of such particles alters the formation of images on the retina. Moreover, the MLBs change over time, which affects properties such as the refractive index of their shell. Hence, this work not only simulates the presence of such particles but also evaluates the incidence of particle parameters such as particle diameter, particle thickness, and shell refractive index, which are set based on reported experimental values. In addition, two wavelengths (400 nm and 700 nm) are used for light passing through the different layers of the computational model. The effects of these parameters on light scattering are analyzed using the simulation results. Further, in these results, the effects of light scattering on image formation can be seen when single particles, early-stage MLBs, or mature MLBs are incorporated in the model. Finally, it is found that particle diameter has the greatest impact on image formation. PMID:28663924

  13. Outer Electrospun Polycaprolactone Shell Induces Massive Foreign Body Reaction and Impairs Axonal Regeneration through 3D Multichannel Chitosan Nerve Guides

    PubMed Central

    Behrens, Peter; Wienecke, Soenke; Chakradeo, Tanmay; Glasmacher, Birgit

    2014-01-01

    We report on the performance of composite nerve grafts with an inner 3D multichannel porous chitosan core and an outer electrospun polycaprolactone shell. The inner chitosan core provided multiple guidance channels for regrowing axons. To analyze the in vivo properties of the bare chitosan cores, we separately implanted them into an epineural sheath. The effects of both graft types on structural and functional regeneration across a 10 mm rat sciatic nerve gap were compared to autologous nerve transplantation (ANT). The mechanical biomaterial properties and the immunological impact of the grafts were assessed with histological techniques before and after transplantation in vivo. Furthermore during a 13-week examination period functional tests and electrophysiological recordings were performed and supplemented by nerve morphometry. The sheathing of the chitosan core with a polycaprolactone shell induced massive foreign body reaction and impairment of nerve regeneration. Although the isolated novel chitosan core did allow regeneration of axons in a similar size distribution as the ANT, the ANT was superior in terms of functional regeneration. We conclude that an outer polycaprolactone shell should not be used for the purpose of bioartificial nerve grafting, while 3D multichannel porous chitosan cores could be candidate scaffolds for structured nerve grafts. PMID:24818158

  14. Outer electrospun polycaprolactone shell induces massive foreign body reaction and impairs axonal regeneration through 3D multichannel chitosan nerve guides.

    PubMed

    Duda, Sven; Dreyer, Lutz; Behrens, Peter; Wienecke, Soenke; Chakradeo, Tanmay; Glasmacher, Birgit; Haastert-Talini, Kirsten

    2014-01-01

    We report on the performance of composite nerve grafts with an inner 3D multichannel porous chitosan core and an outer electrospun polycaprolactone shell. The inner chitosan core provided multiple guidance channels for regrowing axons. To analyze the in vivo properties of the bare chitosan cores, we separately implanted them into an epineural sheath. The effects of both graft types on structural and functional regeneration across a 10 mm rat sciatic nerve gap were compared to autologous nerve transplantation (ANT). The mechanical biomaterial properties and the immunological impact of the grafts were assessed with histological techniques before and after transplantation in vivo. Furthermore during a 13-week examination period functional tests and electrophysiological recordings were performed and supplemented by nerve morphometry. The sheathing of the chitosan core with a polycaprolactone shell induced massive foreign body reaction and impairment of nerve regeneration. Although the isolated novel chitosan core did allow regeneration of axons in a similar size distribution as the ANT, the ANT was superior in terms of functional regeneration. We conclude that an outer polycaprolactone shell should not be used for the purpose of bioartificial nerve grafting, while 3D multichannel porous chitosan cores could be candidate scaffolds for structured nerve grafts.

  15. Simulation and analysis of light scattering by multilamellar bodies present in the human eye.

    PubMed

    Méndez-Aguilar, Emilia M; Kelly-Pérez, Ismael; Berriel-Valdos, L R; Delgado-Atencio, José A

    2017-06-01

    A modified computational model of the human eye was used to obtain and compare different probability density functions, radial profiles of light pattern distributions, and images of the point spread function formed in the human retina under the presence of different kinds of particles inside crystalline lenses suffering from cataracts. Specifically, this work uses simple particles without shells and multilamellar bodies (MLBs) with shells. The emergence of such particles alters the formation of images on the retina. Moreover, the MLBs change over time, which affects properties such as the refractive index of their shell. Hence, this work not only simulates the presence of such particles but also evaluates the incidence of particle parameters such as particle diameter, particle thickness, and shell refractive index, which are set based on reported experimental values. In addition, two wavelengths (400 nm and 700 nm) are used for light passing through the different layers of the computational model. The effects of these parameters on light scattering are analyzed using the simulation results. Further, in these results, the effects of light scattering on image formation can be seen when single particles, early-stage MLBs, or mature MLBs are incorporated in the model. Finally, it is found that particle diameter has the greatest impact on image formation.

  16. Early post-mortem formation of carbonate concretions around tusk-shells over week-month timescales

    NASA Astrophysics Data System (ADS)

    Yoshida, Hidekazu; Ujihara, Atsushi; Minami, Masayo; Asahara, Yoshihiro; Katsuta, Nagayoshi; Yamamoto, Koshi; Sirono, Sin-Iti; Maruyama, Ippei; Nishimoto, Shoji; Metcalfe, Richard

    2015-09-01

    Carbonate concretions occur in sedimentary rocks of widely varying geological ages throughout the world. Many of these concretions are isolated spheres, centered on fossils. The formation of such concretions has been variously explained by diffusion of inorganic carbon and organic matter in buried marine sediments. However, details of the syn-depositional chemical processes by which the isolated spherical shape developed and the associated carbon sources are little known. Here we present evidence that spherical carbonate concretions (diameters φ : 14 ~ 37 mm) around tusk-shells (Fissidentalium spp.) were formed within weeks or months following death of the organism by the seepage of fatty acid from decaying soft body tissues. Characteristic concentrations of carbonate around the mouth of a tusk-shell reveal very rapid formation during the decay of organic matter from the tusk-shell. Available observations and geochemical evidence have enabled us to construct a ‘Diffusion-growth rate cross-plot’ that can be used to estimate the growth rate of all kinds of isolated spherical carbonate concretions identified in marine formations. Results shown here suggest that isolated spherical concretions that are not associated with fossils might also be formed from carbon sourced in the decaying soft body tissues of non-skeletal organisms with otherwise low preservation potential.

  17. The origin and loss of periodic patterning in the turtle shell.

    PubMed

    Moustakas-Verho, Jacqueline E; Zimm, Roland; Cebra-Thomas, Judith; Lempiäinen, Netta K; Kallonen, Aki; Mitchell, Katherine L; Hämäläinen, Keijo; Salazar-Ciudad, Isaac; Jernvall, Jukka; Gilbert, Scott F

    2014-08-01

    The origin of the turtle shell over 200 million years ago greatly modified the amniote body plan, and the morphological plasticity of the shell has promoted the adaptive radiation of turtles. The shell, comprising a dorsal carapace and a ventral plastron, is a layered structure formed by basal endochondral axial skeletal elements (ribs, vertebrae) and plates of bone, which are overlain by keratinous ectodermal scutes. Studies of turtle development have mostly focused on the bones of the shell; however, the genetic regulation of the epidermal scutes has not been investigated. Here, we show that scutes develop from an array of patterned placodes and that these placodes are absent from a soft-shelled turtle in which scutes were lost secondarily. Experimentally inhibiting Shh, Bmp or Fgf signaling results in the disruption of the placodal pattern. Finally, a computational model is used to show how two coupled reaction-diffusion systems reproduce both natural and abnormal variation in turtle scutes. Taken together, these placodal signaling centers are likely to represent developmental modules that are responsible for the evolution of scutes in turtles, and the regulation of these centers has allowed for the diversification of the turtle shell. © 2014. Published by The Company of Biologists Ltd.

  18. Antihalo effects on reaction cross sections for C14,15,16 isotopes

    NASA Astrophysics Data System (ADS)

    Matsumoto, Takuma; Yahiro, Masanobu

    2014-10-01

    We study antihalo effects on reaction cross sections σR for C14,15,16 scattering from a C12 target at 83 MeV/nucleon, using the g-matrix double-folding model. C15 is described by the 14C+n two-body model that reproduces the measured large s-wave spectroscopic factor, i.e., the shell inversion that the 1s1/2 orbital is lower than the 0d5/2 orbital in energy. C16 is described by the 14C+n+n three-body model with the phenomenological three-body force (3BF) that explains the measured small s-wave spectroscopic factor. The 3BF allows the single-particle energies of the 14C+n subsystem to depend on the position r of the second neutron from the center of mass of the subsystem. The 1s1/2 orbital is lower than the 0d5/2 orbital for large r, but the shell inversion is restored for small r. Antihalo effects due to the "partial shell inversion" make σR for C16 smaller than that for C15. We also investigate projectile breakup effects on the mass-number dependence of σR with the continuum-discretized coupled-channel method.

  19. Investigation into the development of computer aided design software for space based sensors

    NASA Technical Reports Server (NTRS)

    Pender, C. W.; Clark, W. L.

    1987-01-01

    The described effort is phase one of the development of a Computer Aided Design (CAD) software to be used to perform radiometric sensor design. The software package will be referred to as SCAD and is directed toward the preliminary phase of the design of space based sensor system. The approach being followed is to develop a modern, graphic intensive, user friendly software package using existing software as building blocks. The emphasis will be directed toward the development of a shell containing menus, smart defaults, and interfaces, which can accommodate a wide variety of existing application software packages. The shell will offer expected utilities such as graphics, tailored menus, and a variety of drivers for I/O devices. Following the development of the shell, the development of SCAD is planned as chiefly selection and integration of appropriate building blocks. The phase one development activities have included: the selection of hardware which will be used with SCAD; the determination of the scope of SCAD; the preliminary evaluation of a number of software packages for applicability to SCAD; determination of a method for achieving required capabilities where voids exist; and then establishing a strategy for binding the software modules into an easy to use tool kit.

  20. Tubular House - Form Follows Technology, Concrete Shell Structure with Inner Thermal Insulation

    NASA Astrophysics Data System (ADS)

    Idem, Robert; Kleczek, Paweł; Pawłowski, Krzysztof; Chudoba, Piotr

    2017-10-01

    The aim of this paper is the theoretical analysis of the possibilities and limitations of using an unconventional technology and the original architectural form stemming from it - the building with external construction and internal insulation. In Central European climatic conditions, the traditional solution for the walls of heated buildings relies on using external thermal insulation. This stems from building physics: it prevents interstitial condensation of water vapour in the wall. Internal insulation is used exceptionally. This is done e.g. in historical buildings undergoing thermal modernization (due to the impossibility of interfering with facade). In such cases, a thermal insulation layer is used on the internal wall surface, along with an additional layer of vapour barrier. The concept of building concerns the intentional usage of an internal insulation. In this case, the construction is a tight external reinforced concrete shell. The architectural form of such building is strongly interrelated with the technology, which was used to build it. The paper presents the essence of this concept in descriptive and drawing form. The basic elements of such building are described (the external construction, the internal insulation and ventilation). As a case study, authors present a project of a residential building along with the description of the applied materials and installation solutions, and the results obtained from thermal, humidity and energetic calculations. The discussion presents the advantages and disadvantages of the proposed concept. The basic advantage of this solution is potentially low building cost. This stems from minimizing the ground works, the simplicity of the joints and the outer finish, as well as from the possibility of prefabrication of the elements. The continuity of the thermal insulation allows to reduce the amount of thermal bridges. The applied technology and form are applicable most of all for small buildings, due to limited possibilities of lighting the interior. The disadvantage of this technology is low heat accumulation of walls. A building in the proposed technology requires constant, forced ventilation. Further theoretical and practical research towards applying this concept would be necessary.

  1. Why are reproductively parasitic fish males so small?—influence of tactic-specific selection

    NASA Astrophysics Data System (ADS)

    Ota, Kazutaka; Kohda, Masanori; Sato, Tetsu

    2010-12-01

    Despite the wide prevalence of alternative reproductive tactics, little attention has been paid to why reproductively parasitic males are so small. In this study, we tackled this issue in a shell-brooding fish Lamprologus callipterus. Sneaky `dwarf males' of this fish remain much smaller than bourgeois conspecifics throughout their life and employ a unique parasitic tactic, i.e. entering into a gastropod shell where a female is spawning, passing through the space between the female and shell wall and staying behind her to ejaculate throughout the spawning event. Here, we tested the prediction that they remain small to get past her through the shell spaces by interpopulation comparison. We showed, across populations, a negative allometry for sexual size dimorphism, an exponential increase of female size with an increase in shell size and a negative correlation between the magnitude of sexual size dimorphism and shell size. These results suggest that the inner spaces strongly regulate dwarf male size. We conclude that the small bodies of dwarf males arise from adaptation to their unique reproductive behaviour.

  2. Tunable Encapsulation Structure of Block Copolymer Coated Single-Walled Carbon Nanotubes in Aqueous Solution

    DOE PAGES

    Han, Youngkyu; Ahn, Suk-Kyun; Zhang, Zhe; ...

    2015-05-15

    The nano-sized and shape-tunable molecular building blocks can provide great opportunities for the fabrication of precisely controlled nanostructures. In this work, we have fabricated a molecular building block of single-walled carbon nanotubes (SWNTs) coated by PPO-PEO-PPO block copolymers whose encapsulation structure can be controlled via temperature or addition of small molecules. The structure and optical properties of SWNT-block copolymers have been investigated by small angle neutron scattering (SANS), ultraviolet-visible (UV-vis) spectroscopy, atomic force microscopy (AFM), and molecular dynamics (MD) simulation. The structure of the hydrated block copolymer layer surrounding SWNT can be controlled reversibly by varying temperature as well asmore » by irreversibly adding 5-methylsalicylic acid (5MS). Increasing hydrophobicity of the polymers with temperature and strong tendency of 5MS to interact with both block copolymers and orbitals of the SWNTs are likely to be responsible for the significant structural change of the block copolymer encapsulation layer, from loose corona shell to tightly encapsulating compact shell. These result shows an efficient and simple way to fabricate and manipulate carbon-based nano building blocks in aqueous systems with tunable structure.« less

  3. Building "Bob": A Project Exploring the Human Body at Western Illinois University Preschool Center

    ERIC Educational Resources Information Center

    Brouette, Scott

    2008-01-01

    When the children at Western Illinois University Preschool Center embarked on a study of human bodies, they decided to build a life-size model of a body, organ by organ from the inside out, to represent some of the things they were learning. This article describes the building of "Bob," the human body model, highlighting the children's…

  4. Numerical Solution for Navier-Stokes Equations

    NASA Technical Reports Server (NTRS)

    Warsi, Z. U. A.; Weed, R. A.; Thompson, J. F.

    1982-01-01

    Carefully selected blend of computational techniques solves complete set of equations for viscous, unsteady, hypersonic flow in general curvilinear coordinates. New algorithm has tested computation of axially directed flow about blunt body having shape similar to that of such practical bodies as wide-body aircraft or artillery shells. Method offers significant computational advantages because of conservation-law form of equations and because it reduces amount of metric data required.

  5. Sea Hare Aplysia punctata (Mollusca: Gastropoda) Can Maintain Shell Calcification under Extreme Ocean Acidification.

    PubMed

    Carey, Nicholas; Dupont, Sam; Sigwart, Julia D

    2016-10-01

    Ocean acidification is expected to cause energetic constraints upon marine calcifying organisms such as molluscs and echinoderms, because of the increased costs of building or maintaining shell material in lower pH. We examined metabolic rate, shell morphometry, and calcification in the sea hare Aplysia punctata under short-term exposure (19 days) to an extreme ocean acidification scenario (pH 7.3, ∼2800 μatm pCO 2 ), along with a group held in control conditions (pH 8.1, ∼344 μatm pCO 2 ). This gastropod and its congeners are broadly distributed and locally abundant grazers, and have an internal shell that protects the internal organs. Specimens were examined for metabolic rate via closed-chamber respirometry, followed by removal and examination of the shell under confocal microscopy. Staining using calcein determined the amount of new calcification that occurred over 6 days at the end of the acclimation period. The width of new, pre-calcified shell on the distal shell margin was also quantified as a proxy for overall shell growth. Aplysia punctata showed a 30% reduction in metabolic rate under low pH, but calcification was not affected. This species is apparently able to maintain calcification rate even under extreme low pH, and even when under the energetic constraints of lower metabolism. This finding adds to the evidence that calcification is a largely autonomous process of crystallization that occurs as long as suitable haeomocoel conditions are preserved. There was, however, evidence that the accretion of new, noncalcified shell material may have been reduced, which would lead to overall reduced shell growth under longer-term exposures to low pH independent of calcification. Our findings highlight that the chief impact of ocean acidification upon the ability of marine invertebrates to maintain their shell under low pH may be energetic constraints that hinder growth of supporting structure, rather than maintenance of calcification.

  6. Comparing Efficiency Projections (released in AEO2010)

    EIA Publications

    2010-01-01

    Realized improvements in energy efficiency generally rely on a combination of technology and economics. The figure below illustrates the role of technology assumptions in the Annual Energy Outlook 2010 projections for energy efficiency in the residential and commercial buildings sector. Projected energy consumption in the Reference case is compared with projections in the Best Available Technology, High Technology, and 2009 Technology cases and an estimate based on an assumption of no change in efficiency for building shells and equipment.

  7. Multilayered silica-biopolymer nanocapsules with a hydrophobic core and a hydrophilic tunable shell thickness

    NASA Astrophysics Data System (ADS)

    Vecchione, Raffaele; Luciani, Giuseppina; Calcagno, Vincenzo; Jakhmola, Anshuman; Silvestri, Brigida; Guarnieri, Daniela; Belli, Valentina; Costantini, Aniello; Netti, Paolo A.

    2016-04-01

    Stable, biocompatible, multifunctional and multicompartment nanocarriers are much needed in the field of nanomedicine. Here, we report a simple, novel strategy to design an engineered nanocarrier system featuring an oil-core/hybrid polymer/silica-shell. Silica shells with a tunable thickness were grown in situ, directly around a highly mono-disperse and stable oil-in-water emulsion system, stabilized by a double bio-functional polyelectrolyte heparin/chitosan layer. Such silica showed a complete degradation in a physiological medium (SBF) in a time frame of three days. Moreover, the outer silica shell was coated with polyethyleneglycol (PEG) in order to confer antifouling properties to the final nanocapsule. The outer silica layer combined its properties (it is an optimal bio-interface for bio-conjugations and for the embedding of hydrophilic drugs in the porous structure) with the capability to stabilize the oil core for the confinement of high payloads of lipophilic tracers (e.g. CdSe quantum dots, Nile Red) and drugs. In addition, polymer layers - besides conferring stability to the emulsion while building the silica shell - can be independently exploited if suitably functionalized, as demonstrated by conjugating chitosan with fluorescein isothiocyanate. Such numerous features in a single nanocarrier system make it very intriguing as a multifunctional platform for smart diagnosis and therapy.Stable, biocompatible, multifunctional and multicompartment nanocarriers are much needed in the field of nanomedicine. Here, we report a simple, novel strategy to design an engineered nanocarrier system featuring an oil-core/hybrid polymer/silica-shell. Silica shells with a tunable thickness were grown in situ, directly around a highly mono-disperse and stable oil-in-water emulsion system, stabilized by a double bio-functional polyelectrolyte heparin/chitosan layer. Such silica showed a complete degradation in a physiological medium (SBF) in a time frame of three days. Moreover, the outer silica shell was coated with polyethyleneglycol (PEG) in order to confer antifouling properties to the final nanocapsule. The outer silica layer combined its properties (it is an optimal bio-interface for bio-conjugations and for the embedding of hydrophilic drugs in the porous structure) with the capability to stabilize the oil core for the confinement of high payloads of lipophilic tracers (e.g. CdSe quantum dots, Nile Red) and drugs. In addition, polymer layers - besides conferring stability to the emulsion while building the silica shell - can be independently exploited if suitably functionalized, as demonstrated by conjugating chitosan with fluorescein isothiocyanate. Such numerous features in a single nanocarrier system make it very intriguing as a multifunctional platform for smart diagnosis and therapy. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr01192f

  8. Fabrication of Fe3O4@mSiO2 Core-Shell Composite Nanoparticles for Drug Delivery Applications

    NASA Astrophysics Data System (ADS)

    Uribe Madrid, Sergio I.; Pal, Umapada; Kang, Young Soo; Kim, Junghoon; Kwon, Hyungjin; Kim, Jungho

    2015-05-01

    We report the synthesis of Fe3O4@mSiO2 nanostructures of different meso-silica (mSiO2) shell thickness, their biocompatibility and behaviors for loading and release of a model drug ibuprofen. The composite nanostructures have superparamagnetic magnetite cores of 208 nm average size and meso-silica shells of 15 to 40 nm thickness. A modified Stöber method was used to grow the meso-silica shells over the hydrothermally grown monodispersed magnetite particles. The composite nanoparticles show very promising drug holding and releasing behaviors, which depend on the thickness of meso-silica shell. The biocompatibility of the meso-silica-coated and uncoated magnetite nanoparticles was tested through cytotoxicity assay on breast cancer (MCF-7), ovarian cancer (SKOV3), normal human lung fibroblasts MRC-5, and IMR-90 cells. The high drug holding capacity and reasonable biocompatibility of the nanostructures make them ideal agents for targeted drug delivery applications in human body.

  9. Structure models: From shell model to ab initio methods. A brief introduction to microscopic theories for exotic nuclei

    NASA Astrophysics Data System (ADS)

    Bacca, Sonia

    2016-04-01

    A brief review of models to describe nuclear structure and reactions properties is presented, starting from the historical shell model picture and encompassing modern ab initio approaches. A selection of recent theoretical results on observables for exotic light and medium-mass nuclei is shown. Emphasis is given to the comparison with experiment and to what can be learned about three-body forces and continuum properties.

  10. MicroShell Minimalist Shell for Xilinx Microprocessors

    NASA Technical Reports Server (NTRS)

    Werne, Thomas A.

    2011-01-01

    MicroShell is a lightweight shell environment for engineers and software developers working with embedded microprocessors in Xilinx FPGAs. (MicroShell has also been successfully ported to run on ARM Cortex-M1 microprocessors in Actel ProASIC3 FPGAs, but without project-integration support.) Micro Shell decreases the time spent performing initial tests of field-programmable gate array (FPGA) designs, simplifies running customizable one-time-only experiments, and provides a familiar-feeling command-line interface. The program comes with a collection of useful functions and enables the designer to add an unlimited number of custom commands, which are callable from the command-line. The commands are parameterizable (using the C-based command-line parameter idiom), so the designer can use one function to exercise hardware with different values. Also, since many hardware peripherals instantiated in FPGAs have reasonably simple register-mapped I/O interfaces, the engineer can edit and view hardware parameter settings at any time without stopping the processor. MicroShell comes with a set of support scripts that interface seamlessly with Xilinx's EDK tool. Adding an instance of MicroShell to a project is as simple as marking a check box in a library configuration dialog box and specifying a software project directory. The support scripts then examine the hardware design, build design-specific functions, conditionally include processor-specific functions, and complete the compilation process. For code-size constrained designs, most of the stock functionality can be excluded from the compiled library. When all of the configurable options are removed from the binary, MicroShell has an unoptimized memory footprint of about 4.8 kB and a size-optimized footprint of about 2.3 kB. Since MicroShell allows unfettered access to all processor-accessible memory locations, it is possible to perform live patching on a running system. This can be useful, for instance, if a bug is discovered in a routine but the system cannot be rebooted: Shell allows a skilled operator to directly edit the binary executable in memory. With some forethought, MicroShell code can be located in a different memory location from custom code, permitting the custom functionality to be overwritten at any time without stopping the controlling shell.

  11. Computation of transonic flow past projectiles at angle of attack

    NASA Technical Reports Server (NTRS)

    Reklis, R. P.; Sturek, W. B.; Bailey, F. R.

    1978-01-01

    Aerodynamic properties of artillery shell such as normal force and pitching moment reach peak values in a narrow transonic Mach number range. In order to compute these quantities, numerical techniques have been developed to obtain solutions to the three-dimensional transonic small disturbance equation about slender bodies at angle of attack. The computation is based on a plane relaxation technique involving Fourier transforms to partially decouple the three-dimensional difference equations. Particular care is taken to assure accurate solutions near corners found in shell designs. Computed surface pressures are compared to experimental measurements for circular arc and cone cylinder bodies which have been selected as test cases. Computed pitching moments are compared to range measurements for a typical projectile shape.

  12. DYNA3D: A computer code for crashworthiness engineering

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hallquist, J.O.; Benson, D.J.

    1986-09-01

    A finite element program with crashworthiness applications has been developed at LLNL. DYNA3D, an explicit, fully vectorized, finite deformation structural dynamics program, has four capabilities that are critical for the efficient and realistic modeling crash phenomena: (1) fully optimized nonlinear solid, shell, and beam elements for representing a structure; (2) a broad range of constitutive models for simulating material behavior; (3) sophisticated contact algorithms for impact interactions; (4) a rigid body capability to represent the bodies away from the impact region at a greatly reduced cost without sacrificing accuracy in the momentum calculations. Basic methodologies of the program are brieflymore » presented along with several crashworthiness calculations. Efficiencies of the Hughes-Liu and Belytschko-Tsay shell formulations are considered.« less

  13. Criteria for applicability of the impulse approach to collisions

    NASA Astrophysics Data System (ADS)

    Sharma, Ramesh D.; Bakshi, Pradip M.; Sindoni, Joseph M.

    1990-06-01

    Using an exact formulation of impulse approach (IA) to atom-diatom collisions, we assess its internal consistency. By comparing the cross sections in the forward and reverse directions for the vibrational-rotational inelastic processes, using the half-on-the-shell (post and prior) models of the two-body t matrix, we show that in both cases the IA leads to a violation of the semidetailed balance (SDB) condition for small scattering angles. An off-shell model for the two-body t matrix, which preserves SDB, is shown to have other serious shortcomings. The cross sections are studied quantitatively as a function of the relative translational energy and the mass of the incident particle, and criteria discussed for the applicability of IA.

  14. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sharma, R.D.; Bakshi, P.M.; Sindoni, J.M.

    Using an exact formulation of impulse approach (IA) to atom-diatom collisions, we assess its internal consistency. By comparing the cross sections in the forward and reverse directions for the vibrational-rotational inelastic processes, using the half-on-the-shell (post and prior) models of the two-body {ital t} matrix, we show that in both cases the IA leads to a violation of the semidetailed balance (SDB) condition for small scattering angles. An off-shell model for the two-body {ital t} matrix, which preserves SDB, is shown to have other serious shortcomings. The cross sections are studied quantitatively as a function of the relative translational energymore » and the mass of the incident particle, and criteria discussed for the applicability of IA.« less

  15. 7. Photograph is copy of historic photo (original print located ...

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

    7. Photograph is copy of historic photo (original print located in Ogden Air Logistics Center, Hill Air Force Base, Utah). Photographer unknown. - Ogden Arsenal, Primer Loading Building for 37mm Shell Loading, 7726 North Carolina Way, Layton, Davis County, UT

  16. Change Is Good...Wrong!

    ERIC Educational Resources Information Center

    Hill, Franklin

    2000-01-01

    Change must be personally relevant, beneficial, clearly defined and believed to be achievable. To renovate school facilities, several steps are necessary: identifying future trends and making them personally applicable, establishing a realistic vision, creating functional facility goals, seeing the building as an empty shell, and considering…

  17. Tidal synchronization of an anelastic multi-layered body: Titan's synchronous rotation

    NASA Astrophysics Data System (ADS)

    Folonier, Hugo A.; Ferraz-Mello, Sylvio

    2017-12-01

    Tidal torque drives the rotational and orbital evolution of planet-satellite and star-exoplanet systems. This paper presents one analytical tidal theory for a viscoelastic multi-layered body with an arbitrary number of homogeneous layers. Starting with the static equilibrium figure, modified to include tide and differential rotation, and using the Newtonian creep approach, we find the dynamical equilibrium figure of the deformed body, which allows us to calculate the tidal potential and the forces acting on the tide generating body, as well as the rotation and orbital elements variations. In the particular case of the two-layer model, we study the tidal synchronization when the gravitational coupling and the friction in the interface between the layers is added. For high relaxation factors (low viscosity), the stationary solution of each layer is synchronous with the orbital mean motion ( n) when the orbit is circular, but the rotational frequencies increase if the orbital eccentricity increases. This behavior is characteristic in the classical Darwinian theories and in the homogeneous case of the creep tide theory. For low relaxation factors (high viscosity), as in planetary satellites, if friction remains low, each layer can be trapped in different spin-orbit resonances with frequencies n/2,n,3n/2,2n,\\ldots . When the friction increases, attractors with differential rotations are destroyed, surviving only commensurabilities in which core and shell have the same velocity of rotation. We apply the theory to Titan. The main results are: (i) the rotational constraint does not allow us to confirm or reject the existence of a subsurface ocean in Titan; and (ii) the crust-atmosphere exchange of angular momentum can be neglected. Using the rotation estimate based on Cassini's observation (Meriggiola et al. in Icarus 275:183-192, 2016), we limit the possible value of the shell relaxation factor, when a deep subsurface ocean is assumed, to γ _s≲ 10^{-9} s^{-1}, which corresponds to a shell's viscosity η _s≳ 10^{18} Pa s, depending on the ocean's thickness and viscosity values. In the case in which a subsurface ocean does not exist, the maximum shell relaxation factor is one order of magnitude smaller and the corresponding minimum shell's viscosity is one order higher.

  18. Modeling of fracture of protective concrete structures under impact loads

    NASA Astrophysics Data System (ADS)

    Radchenko, P. A.; Batuev, S. P.; Radchenko, A. V.; Plevkov, V. S.

    2015-10-01

    This paper presents results of numerical simulation of interaction between a Boeing 747-400 aircraft and the protective shell of a nuclear power plant. The shell is presented as a complex multilayered cellular structure consisting of layers of concrete and fiber concrete bonded with steel trusses. Numerical simulation was performed three-dimensionally using the original algorithm and software taking into account algorithms for building grids of complex geometric objects and parallel computations. Dynamics of the stress-strain state and fracture of the structure were studied. Destruction is described using a two-stage model that allows taking into account anisotropy of elastic and strength properties of concrete and fiber concrete. It is shown that wave processes initiate destruction of the cellular shell structure; cells start to destruct in an unloading wave originating after the compression wave arrival at free cell surfaces.

  19. Experimental evaluation of drying characteristics of sewage sludge and hazelnut shell mixtures

    NASA Astrophysics Data System (ADS)

    Pehlivan, Hüseyin; Ateş, Asude; Özdemir, Mustafa

    2016-11-01

    In this study the drying behavior of organic and agricultural waste mixtures has been experimentally investigated. The usability of sewage sludge as an organic waste and hazelnut shell as an agricultural waste was assessed in different mixture range. The paper discusses the applicability of these mixtures as a recovery energy source. Moisture content of mixtures has been calculated in laboratory and plant conditions. Indoor and outdoor solar sludge drying plants were constructed in pilot scale for experimental purposes. Dry solids and climatic conditions were constantly measured. A total more than 140 samples including for drying has been carried out to build up results. Indoor and outdoor weather conditions are taken into consideration in winter and summer. The most effective drying capacity is obtained in mixture of 20 % hazelnut shell and 80 % sewage sludge.

  20. Review of coal bottom ash and coconut shell in the production of concrete

    NASA Astrophysics Data System (ADS)

    Faisal, S. K.; Mazenan, P. N.; Shahidan, S.; Irwan, J. M.

    2018-04-01

    Concrete is the main construction material in the worldwide construction industry. High demand of sand in the concrete production have been increased which become the problems in industry. Natural sand is the most common material used in the construction industry as natural fine aggregate and it caused the availability of good quality of natural sand keep decreasing. The need for a sustainable and green construction building material is required in the construction industry. Hence, this paper presents utilization of coal bottom ash and coconut shell as partial sand replacement in production of concrete. It is able to save cost and energy other than protecting the environment. In summary, 30% usage of coal bottom ash and 25% replacement of coconut shell as aggregate replacement show the acceptable and satisfactory strength of concrete.

  1. Validity of total and segmental impedance measurements for prediction of body composition across ethnic population groups.

    PubMed

    Deurenberg, P; Deurenberg-Yap, M; Schouten, F J M

    2002-03-01

    To test the impact of body build factors on the validity of impedance-based body composition predictions across (ethnic) population groups and to study the suitability of segmental impedance measurements. Cross-sectional observational study. Ministry of Health and School of Physical Education, Nanyang Technological University, Singapore. A total of 291 female and male Chinese, Malays and Indian Singaporeans, aged 18-69, body mass index (BMI) 16.0-40.2 kg/ m2. Anthropometric parameters were measured in addition to impedance (100 kHz) of the total body, arms and legs. Impedance indexes were calculated as height2/impedance. Arm length (span) and leg length (sitting height), wrist and knee width were measured from which body build indices were calculated. Total body water (TBW) was measured using deuterium oxide dilution. Extra cellular water (ECW) was measured using bromide dilution. Body fat percentage was determined using a chemical four-compartment model. The bias of TBW predicted from total body impedance index (bias: measured minus predicted TBW) was different among the three ethnic groups, TBW being significantly underestimated in Indians compared to Chinese and Malays. This bias was found to be dependent on body water distribution (ECW/TBW) and parameters of body build, mainly relative (to height) arm length. After correcting for differences in body water distribution and body build parameters the differences in bias across the ethnic groups disappeared. The impedance index using total body impedance was better correlated with TBW than the impedance index of arm or leg impedance, even after corrections for body build parameters. The study shows that ethnic-specific bias of impedance-based prediction formulas for body composition is due mainly to differences in body build among the ethnic groups. This means that the use of 'general' prediction equations across different (ethnic) population groups without prior testing of their validity should be avoided. Total body impedance has higher predictive value than segmental impedance.

  2. ISOLATION, CHARACTERIZATION AND IMMUNOCHEMICAL STUDIES ON FIBROUS PROTEINS FROM COWRY SHELL (CYPRAEA MONETA, LINNAEUS)

    PubMed Central

    Togun, R.A.; Balogun, R. O.; Adeyemi, D.O.; Esan, T.A.; Oyatogun, G.M; Oziegbe, E.O; Okonji, R. E.; Kuku, A.

    2017-01-01

    Background: Biomaterials are non-drug substances used to treat, enhance or replace functions of body tissues or organs. Natural sources of biomaterials have recently become the focus of several research activities. Cowry shell constitutes one of the most promising natural sources of biomaterials because of its chemical stability, biodegradability and biocompatibility in the body. However, its applications may be limited due to immunogenic and toxic responses that may occur following implantation, hence this study. Materials and Methods: Crude fibrous protein extracted with citrate buffer from pulverised cowry shells (Cypraea moneta (L)), was resolved into two components (CSP1 and CSP2) by gel filtration. Immunological studies were performed with antisera obtained from rabbits by double immunodiffusion and immunoelectrophoresis techniques. Mice treated with the proteins were observed for signs of toxicity and their liver, kidney, lungs and spleen were processed histologically. Results: The native molecular weight of CSP1 and CSP2 determined by gel filtration were 91kDa and 33kDa respectively. CSP1 and CSP2 displayed single bands on SDS-PAGE with subunit molecular weight values of 19kDa and 19.5kDa respectively. Antisera obtained from rabbits immunised with the crude citrate buffer extracts precipitated the antigen in double immunodiffusion tests. Histopathological examinations revealed a dose-dependent damaging effect of the shell proteins on liver, kidney, lung and spleen tissues of the treated mice. Conclusion: This study showed that cowry shells contain fibrous proteins which are immunogenic and toxic in mice at relatively high concentrations, causing visible organ damage without concurrent physical manifestations. PMID:28480388

  3. High-Performance One-Body Core/Shell Nanowire Supercapacitor Enabled by Conformal Growth of Capacitive 2D WS2 Layers.

    PubMed

    Choudhary, Nitin; Li, Chao; Chung, Hee-Suk; Moore, Julian; Thomas, Jayan; Jung, Yeonwoong

    2016-12-27

    Two-dimensional (2D) transition-metal dichalcogenides (TMDs) have emerged as promising capacitive materials for supercapacitor devices owing to their intrinsically layered structure and large surface areas. Hierarchically integrating 2D TMDs with other functional nanomaterials has recently been pursued to improve electrochemical performances; however, it often suffers from limited cyclic stabilities and capacitance losses due to the poor structural integrity at the interfaces of randomly assembled materials. Here, we report high-performance core/shell nanowire supercapacitors based on an array of one-dimensional (1D) nanowires seamlessly integrated with conformal 2D TMD layers. The 1D and 2D supercapacitor components possess "one-body" geometry with atomically sharp and structurally robust core/shell interfaces, as they were spontaneously converted from identical metal current collectors via sequential oxidation/sulfurization. These hybrid supercapacitors outperform previously developed any stand-alone 2D TMD-based supercapacitors; particularly, exhibiting an exceptional charge-discharge retention over 30,000 cycles owing to their structural robustness, suggesting great potential for unconventional energy storage technologies.

  4. Spike-Nosed Bodies and Forward Injected Jets in Supersonic Flow

    NASA Technical Reports Server (NTRS)

    Gilinsky, M.; Washington, C.; Blankson, I. M.; Shvets, A. I.

    2002-01-01

    The paper contains new numerical simulation and experimental test results of blunt body drag reduction using thin spikes mounted in front of a body and one- or two-phase jets injected against a supersonic flow. Numerical simulations utilizing the NASA CFL3D code were conducted at the Hampton University Fluid Mechanics and Acoustics Laboratory (FM&AL) and experimental tests were conducted using the facilities of the IM/MSU Aeromechanics and Gas Dynamics Laboratory. Previous results were presented at the 37th AIAA/ASME/SAE/ASEE Joint Propulsion Conference. Those results were based on some experimental and numerical simulation tests for supersonic flow around spike-nosed or shell-nosed bodies, and numerical simulations were conducted only for a single spike-nosed or shell-nosed body at zero attack angle, alpha=0. In this paper, experimental test results of gas, liquid and solid particle jet injection against a supersonic flow are presented. In addition, numerical simulation results for supersonic flow around a multiple spike-nosed body with non-zero attack angles and with a gas and solid particle forward jet injection are included. Aerodynamic coefficients: drag, C(sub D), lift, C(sub L), and longitudinal momentum, M(sub z), obtained by numerical simulation and experimental tests are compared and show good agreement.

  5. Spike-Nosed Bodies and Forward Injected Jets in Supersonic Flow

    NASA Technical Reports Server (NTRS)

    Gilinsky, M.; Washington, C.; Blankson, I. M.; Shvets, A. I.

    2002-01-01

    The paper contains new numerical simulation and experimental test results of blunt body drag reduction using thin spikes mounted in front of a body and one- or two-phase jets injected against a supersonic flow. Numerical simulations utilizing the NASA CFL3D code were conducted at the Hampton University Fluid Mechanics and Acoustics Laboratory (FM&AL) and experimental tests were conducted using the facilities of the IM/MSU Aeromechanics and Gas Dynamics Laboratory. Previous results were presented at the 37th AIAA/ASME/SAE/ASEE Joint Propulsion Conference. Those results were based on some experimental and numerical simulation tests for supersonic flow around spike-nosed or shell-nosed bodies, and numerical simulations were conducted only for a single spike-nosed or shell-nosed body at zero attack angle, alpha = 0 degrees. In this paper, experimental test results of gas, liquid and solid particle jet injection against a supersonic flow are presented. In addition, numerical simulation results for supersonic flow around a multiple spike-nosed body with non-zero attack angles and with a gas and solid particle forward jet injection are included. Aerodynamic coefficients: drag, C (sub D), lift, C(sub L), and longitudinal momentum, M(sub z), obtained by numerical simulation and experimental tests are compared and show good agreement.

  6. A change in stripes for cholesteric shells via modulated anchoring

    NASA Astrophysics Data System (ADS)

    Tran, Lisa; Lavrentovich, Maxim; Durey, Guillaume; Darmon, Alexandre; Haase, Martin; Li, Ningwei; Lee, Daeyeon; Stebe, Kathleen; Kamien, Randall; Lopez-Leon, Teresa

    Many of the patterns found in biological systems are also found to self-assemble into cholesteric liquid crystal (CLC) systems. In this work, we probe the effect of varying the perpendicular anchoring strength of a CLC that is confined to a spherical shell. The shell geometry gives the confinement and curvature conditions for the formation of a rich array of meta-stable states, revealing an unexplored region between degenerate parallel anchoring and strong perpendicular anchoring. We modulate the anchoring strength in experiments with two methods: by adjusting the surfactant concentration or, interestingly, by varying the temperature. We find two states not previously reported for CLC shells: a Bouligand arches state, where larger, lateral stripes on the shell can be filled with smaller, longitudinal substripes, and a focal conic domain (FCD) state, where thin stripes wrap into at least two, topologically required, double spirals. We use a Landau-de Gennes model of the CLC to simulate the director configurations of these states. This work identifies the Bouligand arches state in CLC shells and builds upon the existing knowledge of cholesteric FCDs, structures that not only have potential for use as intricate, self-assembly blueprints but are pervasive in biological systems. UPENN MRSEC NSF DMR11-20901; ANR Grant 13-JS08-0006-01; IPGG Program ANR-10-IDEX 0001-02 PSL and ANR-10-EQPX-31.

  7. Synthesis of Engineered Zeolitic Materials: From Classical Zeolites to Hierarchical Core-Shell Materials.

    PubMed

    Masoumifard, Nima; Guillet-Nicolas, Rémy; Kleitz, Freddy

    2018-04-01

    The term "engineered zeolitic materials" refers to a class of materials with a rationally designed pore system and active-sites distribution. They are primarily made of crystalline microporous zeolites as the main building blocks, which can be accompanied by other secondary components to form composite materials. These materials are of potential importance in many industrial fields like catalysis or selective adsorption. Herein, critical aspects related to the synthesis and modification of such materials are discussed. The first section provides a short introduction on classical zeolite structures and properties, and their conventional synthesis methods. Then, the motivating rationale behind the growing demand for structural alteration of these zeolitic materials is discussed, with an emphasis on the ongoing struggles regarding mass-transfer issues. The state-of-the-art techniques that are currently available for overcoming these hurdles are reviewed. Following this, the focus is set on core-shell composites as one of the promising pathways toward the creation of a new generation of highly versatile and efficient engineered zeolitic substances. The synthesis approaches developed thus far to make zeolitic core-shell materials and their analogues, yolk-shell, and hollow materials, are also examined and summarized. Finally, the last section concisely reviews the performance of novel core-shell, yolk-shell, and hollow zeolitic materials for some important industrial applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Temperature-induced plasticity in morphology and relative shell weight in the invasive apple snail Pomacea canaliculata.

    PubMed

    Tamburi, Nicolás E; Seuffert, María E; Martín, Pablo R

    2018-05-01

    Temperature has a great influence on the life-history traits of freshwater snails. In this study we investigated the long term effects of a range of temperatures on shell morphology of the apple snail Pomacea canaliculata, a highly invasive species and an important pest of rice. Analysis of shells using geometric morphometrics showed that the main source of morphological variation was allometry, which was detected in males but not in females. This intersexual divergence in allometric trajectories generates much of the morphological variation evidenced. In females, the monotonic relationship with temperature produced narrower shells in the snails reared at lower temperatures, and more expanded apertures, relatively bigger than the body whorl, at higher temperatures. We also found an inverse relationship between relative shell weight, a proxy for shell thickness, and temperature. The differences in shape and relative shell weight are attributable to the different growth rates associated with different temperatures. Temperature fluctuation around a mean of 23.2 °C seemed to have no influence in shell shape and relative weight when is compared with a constant temperature of 25 °C. Information on the influence of temperature on freshwater snails is important for understanding and predicting changes in the face of global climatic change, especially in traits exhibiting great plasticity, such as shell shape and thickness. This work showed that higher temperatures could result in a relatively thinner shell, implying a greater significance of corrosion in flowing waters and a lower resistance to crushing by predators, especially in low latitude areas. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Evolution of large body size in abalones (Haliotis): Patterns and implications

    USGS Publications Warehouse

    Estes, J.A.; Lindberg, D.R.; Wray, C.

    2005-01-01

    Kelps and other fleshy macroalgae - dominant reef-inhabiting organisms in cool - seasmay have radiated extensively following late Cenozoic polar cooling, thus triggering a chain of evolutionary change in the trophic ecology of nearshore temperate ecosystems. We explore this hypothesis through an analysis of body size in the abalones (Gastropoda; Haliotidae), a widely distributed group in modern oceans that displays a broad range of body sizes and contains fossil representatives from the late Cretaceous (60-75 Ma). Geographic analysis of maximum shell length in living abalones showed that small-bodied species, while most common in the Tropics, have a cosmopolitan distribution, whereas large-bodied species occur exclusively in cold-water ecosystems dominated by kelps and other macroalgae. The phylogeography of body size evolution in extant abalones was assessed by constructing a molecular phylogeny in a mix of large and small species obtained from different regions of the world. This analysis demonstrates that small body size is the plesiomorphic state and largeness has likely arisen at least twice. Finally, we compiled data on shell length from the fossil record to determine how (slowly or suddenly) and when large body size arose in the abalones. These data indicate that large body size appears suddenly at the Miocene/Pliocene boundary. Our findings support the view that fleshy-algal dominated ecosystems radiated rapidly in the coastal oceans with the onset of the most recent glacial age. We conclude with a discussion of the broader implications of this change. ?? 2005 The Paleontological Society. All rights reserved.

  10. 27. BUILDING NO. 271I, INTERIOR OF LEAD AZIDE MIXING ROOM. ...

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

    27. BUILDING NO. 271-I, INTERIOR OF LEAD AZIDE MIXING ROOM. HERE, TWO POUNDS (MAXIMUM) OF LEAD AZIDE WAS MIXED IN SEVEN SMALL POTS EACH SEPARATED FROM THE OTHERS BY THE STEEL WALLS PICTURED HERE. THE POTS ARE ALL FIXED TO A COMMON SHAFT WHICH IS ROTATED BY A HAND CRANK OUTSIDE OF ROOM (SEE HAER NJ-36A-26). - Picatinny Arsenal, 200 Area, Shell Component Loading, State Route 15 near I-80, Dover, Morris County, NJ

  11. Nano-functionalization of protein microspheres

    NASA Astrophysics Data System (ADS)

    Yoon, Sungkwon; Nichols, William T.

    2014-08-01

    Protein microspheres are promising building blocks for the assembly of complex functional materials. Here we demonstrate a set of three techniques that add functionality to the surface of protein microspheres. In the first technique, a positive surface charge on the protein spheres is deposited by electrostatic adsorption. Negatively charged silica and gold nanoparticle colloids can then electrostatically bind reversibly to the microsphere surface. In the second technique, nanoparticles are covalently anchored to the protein shell using a simple one-pot process. The strong covalent bond between sulfur groups in cysteine in the protein shell irreversibly binds to the gold nanoparticles. In the third technique, surface morphology of the protein microsphere is tuned through hydrodynamic instability at the water-oil interface. This is accomplished through the degree of solubility of the oil phase in water. Taken together these three techniques form a platform to create nano-functionalized protein microspheres, which can then be used as building blocks for the assembly of more complex macroscopic materials.

  12. Energy data sourcebook for the US residential sector

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wenzel, T.P.; Koomey, J.G.; Sanchez, M.

    Analysts assessing policies and programs to improve energy efficiency in the residential sector require disparate input data from a variety of sources. This sourcebook, which updates a previous report, compiles these input data into a single location. The data provided include information on end-use unit energy consumption (UEC) values of appliances and equipment efficiency; historical and current appliance and equipment market shares; appliances and equipment efficiency and sales trends; appliance and equipment efficiency standards; cost vs. efficiency data for appliances and equipment; product lifetime estimates; thermal shell characteristics of buildings; heating and cooling loads; shell measure cost data for newmore » and retrofit buildings; baseline housing stocks; forecasts of housing starts; and forecasts of energy prices and other economic drivers. This report is the essential sourcebook for policy analysts interested in residential sector energy use. The report can be downloaded from the Web at http://enduse.lbl. gov/Projects/RED.html. Future updates to the report, errata, and related links, will also be posted at this address.« less

  13. Translation between representation languages

    NASA Technical Reports Server (NTRS)

    Vanbaalen, Jeffrey

    1994-01-01

    A capability for translating between representation languages is critical for effective knowledge base reuse. A translation technology for knowledge representation languages based on the use of an interlingua for communicating knowledge is described. The interlingua-based translation process consists of three major steps: translation from the source language into a subset of the interlingua, translation between subsets of the interlingua, and translation from a subset of the interlingua into the target language. The first translation step into the interlingua can typically be specified in the form of a grammar that describes how each top-level form in the source language translates into the interlingua. In cases where the source language does not have a declarative semantics, such a grammar is also a specification of a declarative semantics for the language. A methodology for building translators that is currently under development is described. A 'translator shell' based on this methodology is also under development. The shell has been used to build translators for multiple representation languages and those translators have successfully translated nontrivial knowledge bases.

  14. Structure and dynamics of the hydration shells of the Al3+ ion

    NASA Astrophysics Data System (ADS)

    Bylaska, Eric J.; Valiev, Marat; Rustad, James R.; Weare, John H.

    2007-03-01

    First principles simulations of the hydration shells surrounding Al3+ ions are reported for temperatures near 300°C. The predicted six water molecules in the octahedral first hydration shell were found to be trigonally coordinated via hydrogen bonds to 12s shell water molecules in agreement with the putative structure used to analyze the x-ray data, but in disagreement with the results reported from conventional molecular dynamics using two-and three-body potentials. Bond lengths and angles of the water molecules in the first and second hydration shells and the average radii of these shells also agreed very well with the results of the x-ray analysis. Water transfers into and out of the second solvation shell were observed to occur on a picosecond time scale via a dissociative mechanism. Beyond the second shell the bonding pattern substantially returned to the tetrahedral structure of bulk water. Most of the simulations were done with 64 solvating water molecules (20ps). Limited simulations with 128 water molecules (7ps) were also carried out. Results agreed as to the general structure of the solvation region and were essentially the same for the first and second shell. However, there were differences in hydrogen bonding and Al-O radial distribution function in the region just beyond the second shell. At the end of the second shell a nearly zero minimum in the Al-O radial distribution was found for the 128 water system. This minimum is less pronounced minimum found for the 64 water system, which may indicate that sizes larger than 64 may be required to reliably predict behavior in this region.

  15. On growth and form of irregular coiled-shell of a terrestrial snail: Plectostoma concinnum (Fulton, 1901) (Mollusca: Caenogastropoda: Diplommatinidae).

    PubMed

    Liew, Thor-Seng; Kok, Annebelle C M; Schilthuizen, Menno; Urdy, Severine

    2014-01-01

    The molluscan shell can be viewed as a petrified representation of the organism's ontogeny and thus can be used as a record of changes in form during growth. However, little empirical data is available on the actual growth and form of shells, as these are hard to quantify and examine simultaneously. To address these issues, we studied the growth and form of a land snail that has an irregularly coiled and heavily ornamented shell-Plectostoma concinnum. The growth data were collected in a natural growth experiment and the actual form changes of the aperture during shell ontogeny were quantified. We used an ontogeny axis that allows data of growth and form to be analysed simultaneously. Then, we examined the association between the growth and the form during three different whorl growing phases, namely, the regular coiled spire phase, the transitional constriction phase, and the distortedly-coiled tuba phase. In addition, we also explored the association between growth rate and the switching between whorl growing mode and rib growing mode. As a result, we show how the changes in the aperture ontogeny profiles in terms of aperture shape, size and growth trajectory, and the changes in growth rates, are associated with the different shell forms at different parts of the shell ontogeny. These associations suggest plausible constraints that underlie the three different shell ontogeny phases and the two different growth modes. We found that the mechanism behind the irregularly coiled-shell is the rotational changes of the animal's body and mantle edge with respect to the previously secreted shell. Overall, we propose that future study should focus on the role of the mantle and the columellar muscular system in the determination of shell form.

  16. 0ħω MEC effect on M1 properties of middle pf-shell nuclei

    NASA Astrophysics Data System (ADS)

    Nakada, H.; Sebe, T.

    1994-09-01

    M1 properties of middle pf-shell nuclei are studied within the framework of a large-scale shell-model calculation, by including two-body operators originating from the MEC effect within the 0ħω space. This MEC effect tends to enhance the M1 matrix elements slightly. However, the 0ħω MEC effect does not change the previous results so much, which have shown notable quenching in the magnetic moments of 55Co and 57Ni due to the 0ħω CP effect, while the 0ħω MEC effect should be kept track of in discussing the M1 properties with ⪅ 10% accuracy.

  17. Layout optimization using the homogenization method

    NASA Technical Reports Server (NTRS)

    Suzuki, Katsuyuki; Kikuchi, Noboru

    1993-01-01

    A generalized layout problem involving sizing, shape, and topology optimization is solved by using the homogenization method for three-dimensional linearly elastic shell structures in order to seek a possibility of establishment of an integrated design system of automotive car bodies, as an extension of the previous work by Bendsoe and Kikuchi. A formulation of a three-dimensional homogenized shell, a solution algorithm, and several examples of computing the optimum layout are presented in this first part of the two articles.

  18. Hen genetic strain and extended cold storage influence on physical egg quality from cage-free aviary housing system.

    PubMed

    Jones, D R; Karcher, D M; Regmi, P; Robison, C O; Gast, R K

    2018-04-02

    In the United States, there is an increase in need for cage-free eggs in retail and food manufacturing sectors. Understanding the impact of cage-free systems and the corresponding management on egg quality is pertinent as the U.S. industry adapts existing housing and builds new cage-free housing structures. A study was conducted comparing 2 brown shell and 2 white shell hen strains housed in a cage-free aviary system. Each set of eggs were placed in cold storage and assessed at 0, 2, 4, 8, and 12 wk. Eggs were collected at 21, 31, 42, and 60 wk of hen age. A full profile of physical quality measurements was conducted on up to 18 intact eggs for each hen strain/egg storage/hen age combination. Egg weight increased approximately 10 g for brown shell and 14 g for white shell eggs as hens aged. Many of the properties monitored were significantly impacted by all 3 main effects (hen strain, egg storage, and hen age) resulting in 3-way interactions. A brown and a white shell strain had stronger shells (44 N; P < 0.0001) than the remaining brown and white shell strains (42 N and 39 N, respectively). The current study also determined volume of shell, total length, maximum width, and percent length at maximum width to more accurately indicate egg shape than shape index. One brown shell strain produced eggs with the most consistent shape characteristics over the hen ages monitored. White shell eggs from the cage-free aviary housing produced the highest whole-egg total solids between 31 to 60 wk of hen age, whereas brown shell eggs resulted in the most consistent level of whole-egg total solids (22-23.5%). The brown and white shell strains in the current study produce cage-free aviary eggs with distinctive physical quality attributes. The outcomes from this study can be utilized by the U.S. egg industry in planning management strategies and market placement of cage-free eggs.

  19. Building blocks for subleading helicity operators

    DOE PAGES

    Kolodrubetz, Daniel W.; Moult, Ian; Stewart, Iain W.

    2016-05-24

    On-shell helicity methods provide powerful tools for determining scattering amplitudes, which have a one-to-one correspondence with leading power helicity operators in the Soft-Collinear Effective Theory (SCET) away from singular regions of phase space. We show that helicity based operators are also useful for enumerating power suppressed SCET operators, which encode subleading amplitude information about singular limits. In particular, we present a complete set of scalar helicity building blocks that are valid for constructing operators at any order in the SCET power expansion. In conclusion, we also describe an interesting angular momentum selection rule that restricts how these building blocks canmore » be assembled.« less

  20. Hepatocyte growth factor is crucial for development of the carapace in turtles

    PubMed Central

    Kawashima-Ohya, Yoshie; Narita, Yuichi; Nagashima, Hiroshi; Usuda, Ryo; Kuratani, Shigeru

    2011-01-01

    Turtles are characterized by their shell, composed of a dorsal carapace and a ventral plastron. The carapace first appears as the turtle-specific carapacial ridge (CR) on the lateral aspect of the embryonic flank. Accompanying the acquisition of the shell, unlike in other amniotes, hypaxial muscles in turtle embryos appear as thin threads of fibrous tissue. To understand carapacial evolution from the perspective of muscle development, we compared the development of the muscle plate, the anlage of hypaxial muscles, between the Chinese soft-shelled turtle, Pelodiscus sinensis, and chicken embryos. We found that the ventrolateral lip (VLL) of the thoracic dermomyotome of P. sinensis delaminates early and produces sparse muscle plate in the lateral body wall. Expression patterns of the regulatory genes for myotome differentiation, such as Myf5, myogenin, Pax3, and Pax7 have been conserved among amniotes, including turtles. However, in P. sinensis embryos, the gene hepatocyte growth factor (HGF), encoding a regulatory factor for delamination of the dermomyotomal VLL, was uniquely expressed in sclerotome and the lateral body wall at the interlimb level. Implantation of COS-7 cells expressing a HGF antagonist into the turtle embryo inhibited CR formation. We conclude that the de novo expression of HGF in the turtle mesoderm would have played an innovative role resulting in the acquisition of the turtle-specific body plan. PMID:21535464

  1. Body weight of hypersonic aircraft, part 1

    NASA Technical Reports Server (NTRS)

    Ardema, Mark D.

    1988-01-01

    The load bearing body weight of wing-body and all-body hypersonic aircraft is estimated for a wide variety of structural materials and geometries. Variations of weight with key design and configuration parameters are presented and discussed. Both hot and cool structure approaches are considered in isotropic, organic composite, and metal matrix composite materials; structural shells are sandwich or skin-stringer. Conformal and pillow-tank designs are investigated for the all-body shape. The results identify the most promising hypersonic aircraft body structure design approaches and their weight trends. Geometric definition of vehicle shapes and structural analysis methods are presented in appendices.

  2. The argonaut shell: gas-mediated buoyancy control in a pelagic octopus.

    PubMed

    Finn, Julian K; Norman, Mark D

    2010-10-07

    Argonauts (Cephalopoda: Argonautidae) are a group of rarely encountered open-ocean pelagic octopuses with benthic ancestry. Female argonauts inhabit a brittle 'paper nautilus' shell, the role of which has puzzled naturalists for millennia. The primary role attributed to the shell has been as a receptacle for egg deposition and brooding. Our observations of wild argonauts have revealed that the thin calcareous shell also functions as a hydrostatic structure, employed by the female argonaut to precisely control buoyancy at varying depths. Female argonauts use the shell to 'gulp' a measured volume of air at the sea surface, seal off the captured gas using flanged arms and forcefully dive to a depth where the compressed gas buoyancy counteracts body weight. This process allows the female argonaut to attain neutral buoyancy at depth and potentially adjust buoyancy to counter the increased (and significant) weight of eggs during reproductive periods. Evolution of this air-capture strategy enables this negatively buoyant octopus to survive free of the sea floor. This major shift in life mode from benthic to pelagic shows strong evolutionary parallels with the origins of all cephalopods, which attained gas-mediated buoyancy via the closed-chambered shells of the true nautiluses and their relatives.

  3. Curvature-driven morphing of non-Euclidean shells

    NASA Astrophysics Data System (ADS)

    Pezzulla, Matteo; Stoop, Norbert; Jiang, Xin; Holmes, D. P.

    2017-05-01

    We investigate how thin structures change their shape in response to non-mechanical stimuli that can be interpreted as variations in the structure's natural curvature. Starting from the theory of non-Euclidean plates and shells, we derive an effective model that reduces a three-dimensional stimulus to the natural fundamental forms of the mid-surface of the structure, incorporating expansion, or growth, in the thickness. Then, we apply the model to a variety of thin bodies, from flat plates to spherical shells, obtaining excellent agreement between theory and numerics. We show how cylinders and cones can either bend more or unroll, and eventually snap and rotate. We also study the nearly isometric deformations of a spherical shell and describe how this shape change is ruled by the geometry of a spindle. As the derived results stem from a purely geometrical model, they are general and scalable.

  4. Helmet of a laminate construction of polycarbonate and polysulfone polymeric material

    NASA Technical Reports Server (NTRS)

    Kosmo, Joseph J. (Inventor); Dawn, Frederic S. (Inventor)

    1991-01-01

    An article of laminate construction is disclosed which is comprised of an underlayer of polycarbonate polymer material to which is applied a chemically resistant outer layer of polysulfone. The layers which are joined by compression-heat molding, are molded to form the shape of a body protective shell such as a space helmet comprising a shell of polycarbonate, polysulfone laminate construction attached at its open end to a sealing ring adapted for connection to a space suit. The front portion of the shell provides a transparent visor for the helmet. An outer visor of polycarbonate polysulfone laminate construction is pivotally mounted to the sealing ring for covering the transparent visor portion of the shell during extravehicular activities. The polycarbonate under layer of the outer visor is coated on its inner surface with a vacuum deposit of gold to provide additional thermal radiation resistance.

  5. Ascorbic-acid-assisted growth of high quality M@ZnO: a growth mechanism and kinetics study.

    PubMed

    Yang, Yun; Han, Shuhua; Zhou, Guangju; Zhang, Lijie; Li, Xingliang; Zou, Chao; Huang, Shaoming

    2013-12-07

    We present a general route for synthesizing M@ZnO nanoparticles (NPs) by using ascorbic acid (AA) to induce deposition of ZnO on various shaped and structured cationic-surfactant-capped NP surfaces (noble, magnetic, semiconductor, rod-like, spherical, cubic, dendrite, alloy, core@shell). The results show that the complexing (AA and Zn(2+)) and cooperative effects (AA and CTAB) play important roles in the formation of polycrystalline ZnO shells. Besides, the growth kinetics of M@ZnO was systematically studied. It was found that the slow growth rate favors the successful formation of uniform core@ZnO NPs with relatively loose shells. An appropriate growth rate allows achieving high quality M@ZnO NPs with dense shells. However, very fast growth causes significant additional nucleation and the formation of pure ZnO NPs. This general method is suitable for preparing M@ZnO using seed NPs prepared in both water and organic phases. It might be an alternative route for functionalizing NPs for bioapplications (ZnO is biocompatible), modulating material properties as designed, or synthesizing template materials for building other nanostructures.

  6. Structure formation beyond shell-crossing: nonperturbative expansions and late-time attractors

    NASA Astrophysics Data System (ADS)

    Pietroni, Massimo

    2018-06-01

    Structure formation in 1+1 dimensions is considered, with emphasis on the effects of shell-crossing. The breakdown of the perturbative expansion beyond shell-crossing is discussed, and it is shown, in a simple example, that the perturbative series can be extended to a transseries including nonperturbative terms. The latter converges to the exact result well beyond the range of validity of perturbation theory. The crucial role of the divergences induced by shell-crossing is discussed. They provide constraints on the structure of the transseries and act as a bridge between the perturbative and the nonperturbative sectors. Then, we show that the dynamics in the deep multistreaming regime is governed by attractors. In the case of simple initial conditions, these attractors coincide with the asymptotic configurations of the adhesion model, but in general they may differ. These results are applied to a cosmological setting, and an algorithm to build the attractor solution starting from the Zel'dovich approximation is developed. Finally, this algorithm is applied to the search of `haloes' and the results are compared with those obtained from the exact dynamical equations.

  7. 85. Neg. No. F51, Apr 13, 1930, INTERIORASSEMBLY BUILDING, BODY ...

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

    85. Neg. No. F-51, Apr 13, 1930, INTERIOR-ASSEMBLY BUILDING, BODY AND CUSHION LINE - Ford Motor Company Long Beach Assembly Plant, Assembly Building, 700 Henry Ford Avenue, Long Beach, Los Angeles County, CA

  8. 79. Neg. No. F61A, Apr 13, 1930, INTERIORASSEMBLY BUILDING, BODY ...

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

    79. Neg. No. F-61A, Apr 13, 1930, INTERIOR-ASSEMBLY BUILDING, BODY CONSTRUCTION - Ford Motor Company Long Beach Assembly Plant, Assembly Building, 700 Henry Ford Avenue, Long Beach, Los Angeles County, CA

  9. 86. Neg. No. F64, Apr 13, 1930, INTERIORASSEMBLY BUILDING, BODY ...

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

    86. Neg. No. F-64, Apr 13, 1930, INTERIOR-ASSEMBLY BUILDING, BODY STORAGE CONVEYOR - Ford Motor Company Long Beach Assembly Plant, Assembly Building, 700 Henry Ford Avenue, Long Beach, Los Angeles County, CA

  10. Brain-Building Math Games.

    ERIC Educational Resources Information Center

    Jung, Loretta Welk

    1983-01-01

    Index cards, masking tape, pizza shells, golf tees, and empty soda bottles can be used to make manipulative objects to be used in children's mathematics games. Twenty-two games that provide practice in number drills and problem solving are described, along with instructions for making objects needed for the games. (PP)

  11. TEx-Sys Model for Building Intelligent Tutoring Systems

    ERIC Educational Resources Information Center

    Stankov, Slavomir; Rosic, Marko; Zitko, Branko; Grubisic, Ani

    2008-01-01

    Special classes of asynchronous e-learning systems are the intelligent tutoring systems which represent an advanced learning and teaching environment adaptable to individual student's characteristics. Authoring shells have an environment that enables development of the intelligent tutoring systems. In this paper we present, in entirety, for the…

  12. Geometric Electron Models.

    ERIC Educational Resources Information Center

    Nika, G. Gerald; Parameswaran, R.

    1997-01-01

    Describes a visual approach for explaining the filling of electrons in the shells, subshells, and orbitals of the chemical elements. Enables students to apply the principles of atomic electron configuration while using manipulatives to model the building up of electron configurations as the atomic numbers of elements increase on the periodic…

  13. A new freshwater snail genus (Hydrobiidae, Gastropoda) from Montenegro, with a discussion on gastropod diversity and endemism in Skadar Lake

    PubMed Central

    Pešić, Vladimir; Glöer, Peter

    2013-01-01

    Abstract Karucia sublacustrina a new species of freshwater snails (Hydrobiidae, Gastropoda) is described based on material collected from Skadar Lake (Montenegro, Albania). The new species belongs to monotypic genus Karucia gen. n. The shell morphology and body shape of the new genus resembles Radomaniola Szarowska, 2006 and Grossuana Radoman, 1973, from which it differs in the larger shells with relatively slim and a slightly, but clearly shouldered body whorl. The number of gastropods from Skadar Lake basin tallies now 50 species. The adjusted rate of gastropod endemicity for Skadar Lake basin is estimated to be 38%. By compiling faunal and taxonomic data we also aim to provide information of relevance as to conservation efforts. PMID:23794834

  14. Food composition and feeding habits of some fresh water fishes in various water systems at Abbassa, Egypt, with special reference to snails transmitting diseases.

    PubMed

    El Gamal, Abd El-Rahman A; Ismail, Nahed M M

    2005-08-01

    Study of feeding habits of freshwater fishes collected from ponds at World Fish Center (ICLARM) showed that the African catfish, Clarias gariepinus and Forskal catfish, Bagras bayad had the highest proportion of full stomachs (31-58% & 44-45% respectively). In cichlid fishes, the rate of full stomachs was much lower, being 0.0-12.5% and showed higher incidence of empty stomachs that varied from 37.5% for Oreochromis niloticus to 78.3% for Sarotherodon galilaeus. Food items were analyzed by the percentage of point assessment (P%), abundance (N%) and frequency of occurrence (F%). Results of the three methods of analyses (Index of relative importance, I.R.I) emphasized the importance of plants (1214.7) as a major food resource in the stomach of Nile tilapia, O. niloticus followed by shell fragments (628.5), whereas, snail soft bodies were the main food category in the diet of hybrid tilapia O. niloticus x O. aureus (2539.3). Shell fragments (652) and snail soft bodies (296.9) were the 1st in relative importance as foods of O. aurea. In case of S. galillae, shell fragments (338) came 2nd in I.R.I. after plants (559). Present investigation shows that shell fragments were represented by 11.1% and 15.1% in the diet of African catfish, C. gariepinus by (N%) and (P%) methods, however, they came as the second food item in its diet by I.R.I (1237.3). According to F% method, both shell fragments and Crustacea were present in the diet of C. gariepinus considerable proportions each of 47.4%. Shell fragments were represented by low proportions in the diet of B. bayad 3.9, 2.1 and 22.2 by N%, P% and F% respectively.

  15. Electronic structure of CdSe-ZnS 2D nanoplatelets

    NASA Astrophysics Data System (ADS)

    Cruguel, Hervé; Livache, Clément; Martinez, Bertille; Pedetti, Silvia; Pierucci, Debora; Izquierdo, Eva; Dufour, Marion; Ithurria, Sandrine; Aubin, Hervé; Ouerghi, Abdelkarim; Lacaze, Emmanuelle; Silly, Mathieu G.; Dubertret, Benoit; Lhuillier, Emmanuel

    2017-04-01

    Among colloidal nanocrystals, 2D nanoplatelets (NPLs) made of cadmium chalcogenides have led to especially well controlled optical features. However, the growth of core shell heterostructures has so far been mostly focused on CdS shells, while more confined materials will be more promising to decouple the emitting quantum states of the core from their external environment. Using k.p simulation, we demonstrate that a ZnS shell reduces by a factor 10 the leakage of the wavefunction into the surrounding medium. Using X-ray photoemission (XPS), we confirm that the CdSe active layer is indeed unoxidized. Finally, we build an effective electronic spectrum for these CdSe/ZnS NPLs on an absolute energy scale which is a critical set of parameters for the future integration of this material into optoelectronic devices. We determine the work function (WF) to be 4.47 eV while the material is behaving as an n-type semiconductor.

  16. Engineering the Bacterial Microcompartment Domain for Molecular Scaffolding Applications

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Young, Eric J.; Burton, Rodney; Mahalik, Jyoti P.

    As synthetic biology advances the intricacy of engineered biological systems, the importance of spatial organization within the cellular environment must not be marginalized. Increasingly, biological engineers are investigating means to control spatial organization within the cell, mimicking strategies used by natural pathways to increase flux and reduce cross-talk. A modular platform for constructing a diverse set of defined, programmable architectures would greatly assist in improving yields from introduced metabolic pathways and increasing insulation of other heterologous systems. Here, we review recent research on the shell proteins of bacterial microcompartments and discuss their potential application as “building blocks” for a rangemore » of customized intracellular scaffolds. As a result, we summarize the state of knowledge on the self-assembly of BMC shell proteins and discuss future avenues of research that will be important to realize the potential of BMC shell proteins as predictively assembling and programmable biological materials for bioengineering.« less

  17. Engineering the Bacterial Microcompartment Domain for Molecular Scaffolding Applications

    DOE PAGES

    Young, Eric J.; Burton, Rodney; Mahalik, Jyoti P.; ...

    2017-07-31

    As synthetic biology advances the intricacy of engineered biological systems, the importance of spatial organization within the cellular environment must not be marginalized. Increasingly, biological engineers are investigating means to control spatial organization within the cell, mimicking strategies used by natural pathways to increase flux and reduce cross-talk. A modular platform for constructing a diverse set of defined, programmable architectures would greatly assist in improving yields from introduced metabolic pathways and increasing insulation of other heterologous systems. Here, we review recent research on the shell proteins of bacterial microcompartments and discuss their potential application as “building blocks” for a rangemore » of customized intracellular scaffolds. As a result, we summarize the state of knowledge on the self-assembly of BMC shell proteins and discuss future avenues of research that will be important to realize the potential of BMC shell proteins as predictively assembling and programmable biological materials for bioengineering.« less

  18. Engineering the Bacterial Microcompartment Domain for Molecular Scaffolding Applications

    PubMed Central

    Young, Eric J.; Burton, Rodney; Mahalik, Jyoti P.; Sumpter, Bobby G.; Fuentes-Cabrera, Miguel; Kerfeld, Cheryl A.; Ducat, Daniel C.

    2017-01-01

    As synthetic biology advances the intricacy of engineered biological systems, the importance of spatial organization within the cellular environment must not be marginalized. Increasingly, biological engineers are investigating means to control spatial organization within the cell, mimicking strategies used by natural pathways to increase flux and reduce cross-talk. A modular platform for constructing a diverse set of defined, programmable architectures would greatly assist in improving yields from introduced metabolic pathways and increasing insulation of other heterologous systems. Here, we review recent research on the shell proteins of bacterial microcompartments and discuss their potential application as “building blocks” for a range of customized intracellular scaffolds. We summarize the state of knowledge on the self-assembly of BMC shell proteins and discuss future avenues of research that will be important to realize the potential of BMC shell proteins as predictively assembling and programmable biological materials for bioengineering. PMID:28824573

  19. Modeling of fracture of protective concrete structures under impact loads

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Radchenko, P. A., E-mail: radchenko@live.ru; Batuev, S. P.; Radchenko, A. V.

    This paper presents results of numerical simulation of interaction between a Boeing 747-400 aircraft and the protective shell of a nuclear power plant. The shell is presented as a complex multilayered cellular structure consisting of layers of concrete and fiber concrete bonded with steel trusses. Numerical simulation was performed three-dimensionally using the original algorithm and software taking into account algorithms for building grids of complex geometric objects and parallel computations. Dynamics of the stress-strain state and fracture of the structure were studied. Destruction is described using a two-stage model that allows taking into account anisotropy of elastic and strength propertiesmore » of concrete and fiber concrete. It is shown that wave processes initiate destruction of the cellular shell structure; cells start to destruct in an unloading wave originating after the compression wave arrival at free cell surfaces.« less

  20. 87. Neg. No. F74A, Jun 14, 1930, INTERIORASSEMBLY BUILDING, BODY ...

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

    87. Neg. No. F-74A, Jun 14, 1930, INTERIOR-ASSEMBLY BUILDING, BODY STORAGE CONVEYORS - Ford Motor Company Long Beach Assembly Plant, Assembly Building, 700 Henry Ford Avenue, Long Beach, Los Angeles County, CA

  1. Cinderella's helping pigeons of the microbial world: The potential of testate amoebae for identifying cryptotephra.

    PubMed

    Delaine, Maxence; Fernández, Leonardo D; Armynot du Châtelet, Eric; Recourt, Philippe; Potdevin, Jean-Luc; Mitchell, Edward A D; Bernard, Nadine

    2016-09-01

    Cryptotephra (particles <125μm) is a key record for monitoring past and current volcanic activity. However, its extraction from the host sediment and analysis is often long and difficult because of its small size. Finding a simple method to extract cryptotephra from environmental samples would therefore make its analysis much easier. We hypothesized that arcellinid testate amoebae may hold such a potential. These free-living shelled protists are among the earliest microorganisms to colonize volcanic tephra, and build their shell by agglutinating minerals from their environment. We analyzed by X-ray Spectrometry the mineral signature of tephra from the 2011 Puyehue-Cordon Caulle Volcanic Complex (Chile) eruption ash fallout and compared it to that of the shells of 51 individual testate amoebae (three individuals from each of 17 species) from 13 samples collected at different distances from the active vent. The mineral composition of particles within shells closely matched that of similar size class particles from their environment. The capacity of testate amoebae to randomly use mineral grains from their environment makes it possible to use their shells to assess the mineral composition of cryptotephra from soil, peat or sediment samples. Testate amoebae therefore represent the microbial world's version of Cinderella's helping pigeons. Copyright © 2016 Elsevier GmbH. All rights reserved.

  2. Mechanisms of Earth activity forsed by external celestial bodies:energy budjet and nature of cyclicity

    NASA Astrophysics Data System (ADS)

    Barkin, Yu. V.; Ferrandiz, J. M.

    2003-04-01

    In given report we discuss tidal and non-tidal mechanisms of forced tectonic (endogenous) activity of the Earth caused by gravitational attraction of the Moon, Sun and the planets. On the base of the classical solution of the problem of elasticity for model of the Earth with concentric mass distribution the evaluations of the tidal energy and power of Earth lunar-solar deformations, including their joint effect, were obtained. Important role of the joint energetic effect of rotational deformation of the Earth with lunar and solar tides was illustrated. Gravitational interaction of the Moon and Sun with non-spherical, non-homogeneous shells of the Earth generates big additional mechanical forces and moments of the interaction of the neighboring shells (rigid core, liquid core, mantle, lithosphere and separate plates). Acting of these forces and moments in the different time scales on the corresponding sells generates cyclic perturbations of the tensional state of the shells, their deformations, small relative translational displacements and small relative rotational oscillations of the shells. In geological period of time it leads to a fundamental tectonic reconstruction of the Earth. These additional forces and moments of the cyclic celestial-mechanical nature produce cyclic deformations of the all layers of the body and organize and control practically all natural processes. The additional force between mantle and core is cyclic and characterized by the wide basis of frequencies typical for orbital motions (of the Sun, Moon and planets), for rotational motion of the Earth, Moon and Sun and for many from observed natural processes. The problem about small relative translatory-rotary motion of the two shells separated by the thin viscous-elastic layer is studied. The differential equations of motion were obtained and have been studied in particular cases (plane motion of system; case of two axisymmetrical interacting shells and oth.) by approximate methods of small parameter and methods of averaging. Some regimes of the relative translatory-rotary motions of the shells were described in analytical form. Wide set observed geodynamical and geophysical phenomena can be illustrated as results or as reflections of the small and slow relative displacements of the shells in corresponding time-scales. Barkin's work was accepted and financed by RFBR grant 02-05-64176 and by grant SAB2000-0235 of Ministry of Education of Spain (Secretaria de Estado de Educacion y Universidades).

  3. Geometrically nonlinear analysis of laminated elastic structures

    NASA Technical Reports Server (NTRS)

    Reddy, J. N.

    1984-01-01

    Laminated composite plates and shells that can be used to model automobile bodies, aircraft wings and fuselages, and pressure vessels among many other were analyzed. The finite element method, a numerical technique for engineering analysis of structures, is used to model the geometry and approximate the solution. Various alternative formulations for analyzing laminated plates and shells are developed and their finite element models are tested for accuracy and economy in computation. These include the shear deformation laminate theory and degenerated 3-D elasticity theory for laminates.

  4. Geodynamic Modeling of Planetary Ice-Oceans: Evolution of Ice-Shell Thickness in Convecting Two-Phase Systems

    NASA Astrophysics Data System (ADS)

    Allu Peddinti, D.; McNamara, A. K.

    2016-12-01

    Along with the newly unveiled icy surface of Pluto, several icy planetary bodies show indications of an active surface perhaps underlain by liquid oceans of some size. This augments the interest to explore the evolution of an ice-ocean system and its surface implications. The geologically young surface of the Jovian moon Europa lends much speculation to variations in ice-shell thickness over time. Along with the observed surface features, it suggests the possibility of episodic convection and conduction within the ice-shell as it evolved. What factors would control the growth of the ice-shell as it forms? If and how would those factors determine the thickness of the ice-shell and consequently the heat transfer? Would parameters such as tidal heating or initial temperature affect how the ice-shell grows and to what significance? We perform numerical experiments using geodynamical models of the two-phase ice-water system to study the evolution of planetary ice-oceans such as that of Europa. The models evolve self-consistently from an initial liquid ocean as it cools with time. The effects of presence, absence and magnitude of tidal heating on ice-shell thickness are studied in different models. The vigor of convection changes as the ice-shell continues to thicken. Initial modeling results track changes in the growth rate of the ice-shell as the vigor of the convection changes. The magnitude and temporal location of the rate change varies with different properties of tidal heating and values of initial temperature. A comparative study of models is presented to demonstrate how as the ice-shell is forming, its growth rate and convection are affected by processes such as tidal heating.

  5. On growth and form of irregular coiled-shell of a terrestrial snail: Plectostoma concinnum (Fulton, 1901) (Mollusca: Caenogastropoda: Diplommatinidae)

    PubMed Central

    Kok, Annebelle C.M.; Schilthuizen, Menno; Urdy, Severine

    2014-01-01

    The molluscan shell can be viewed as a petrified representation of the organism’s ontogeny and thus can be used as a record of changes in form during growth. However, little empirical data is available on the actual growth and form of shells, as these are hard to quantify and examine simultaneously. To address these issues, we studied the growth and form of a land snail that has an irregularly coiled and heavily ornamented shell–Plectostoma concinnum. The growth data were collected in a natural growth experiment and the actual form changes of the aperture during shell ontogeny were quantified. We used an ontogeny axis that allows data of growth and form to be analysed simultaneously. Then, we examined the association between the growth and the form during three different whorl growing phases, namely, the regular coiled spire phase, the transitional constriction phase, and the distortedly-coiled tuba phase. In addition, we also explored the association between growth rate and the switching between whorl growing mode and rib growing mode. As a result, we show how the changes in the aperture ontogeny profiles in terms of aperture shape, size and growth trajectory, and the changes in growth rates, are associated with the different shell forms at different parts of the shell ontogeny. These associations suggest plausible constraints that underlie the three different shell ontogeny phases and the two different growth modes. We found that the mechanism behind the irregularly coiled-shell is the rotational changes of the animal’s body and mantle edge with respect to the previously secreted shell. Overall, we propose that future study should focus on the role of the mantle and the columellar muscular system in the determination of shell form. PMID:24883245

  6. Characterization and hypoglycemic activity of a β-pyran polysaccharides from bamboo shoot (Leleba oldhami Nakal) shells.

    PubMed

    Zheng, Yafeng; Zhang, Shuai; Wang, Qi; Lu, Xu; Lin, Liangmei; Tian, Yuting; Xiao, Jianbo; Zheng, Baodong

    2016-06-25

    The bamboo shoot (Leleba oldhami Nakal) shell is a by-product during bamboo shoot processing. It is a cheap and available resource for dietary polysaccharides. Herein, a novel polysaccharide BSSP2a was isolated and characterized from the bamboo shoot shell polysaccharides, and it was identified as a homogeneous highly-branched beta type pyran polysaccharide with a molecular weight of 1.63×10(4)kDa, which consisted of arabinose, xylose, mannose, glucose and galactose at a molar ratio of 20.4:4.9:1:3.4:20.6. The crude polysaccharides (BSSP) from the bamboo shoots shell showed hypoglycemic activity on the high fat diet and streptozotocin induced diabetic mice in a dose-dependent manner. The administration of high dose BSSP (400mg/kg) improved body weight loss and serum insulin loss, and significantly decreased the blood glucose level, serum triglycerides as well as total cholesterol levels by 48.7%, 34.8% and 26.5%, respectively. The results highlight the potential of the bamboo shoot shell polysaccharides as a natural anti-diabetic agent. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. A rapidly evolving secretome builds and patterns a sea shell

    PubMed Central

    Jackson, Daniel J; McDougall, Carmel; Green, Kathryn; Simpson, Fiona; Wörheide, Gert; Degnan, Bernard M

    2006-01-01

    Background Instructions to fabricate mineralized structures with distinct nanoscale architectures, such as seashells and coral and vertebrate skeletons, are encoded in the genomes of a wide variety of animals. In mollusks, the mantle is responsible for the extracellular production of the shell, directing the ordered biomineralization of CaCO3 and the deposition of architectural and color patterns. The evolutionary origins of the ability to synthesize calcified structures across various metazoan taxa remain obscure, with only a small number of protein families identified from molluskan shells. The recent sequencing of a wide range of metazoan genomes coupled with the analysis of gene expression in non-model animals has allowed us to investigate the evolution and process of biomineralization in gastropod mollusks. Results Here we show that over 25% of the genes expressed in the mantle of the vetigastropod Haliotis asinina encode secreted proteins, indicating that hundreds of proteins are likely to be contributing to shell fabrication and patterning. Almost 85% of the secretome encodes novel proteins; remarkably, only 19% of these have identifiable homologues in the full genome of the patellogastropod Lottia scutum. The spatial expression profiles of mantle genes that belong to the secretome is restricted to discrete mantle zones, with each zone responsible for the fabrication of one of the structural layers of the shell. Patterned expression of a subset of genes along the length of the mantle is indicative of roles in shell ornamentation. For example, Has-sometsuke maps precisely to pigmentation patterns in the shell, providing the first case of a gene product to be involved in molluskan shell pigmentation. We also describe the expression of two novel genes involved in nacre (mother of pearl) deposition. Conclusion The unexpected complexity and evolvability of this secretome and the modular design of the molluskan mantle enables diversification of shell strength and design, and as such must contribute to the variety of adaptive architectures and colors found in mollusk shells. The composition of this novel mantle-specific secretome suggests that there are significant molecular differences in the ways in which gastropods synthesize their shells. PMID:17121673

  8. Assessing the Potential for Bioremediation through Formation and Fate of Metal Rich Granules in the Terrestrial Environment

    DTIC Science & Technology

    2011-05-01

    laboratory ► biochemistry and analytical laboratories BUILDING STRONG® Impacts of Lead (Pb) • Most common metal contaminant on US Army small arms...Diffraction (XRD): Crystalline phase identification through fingerprinting Tungsten and Calcium in Snail Shell W Identificati on of Selenium and

  9. ADVANCED INSULATIONS FOR REFRIGERATOR/FREEZERS: THE POTENTIAL FOR NEW SHELL DESIGNS INCORPORATING POLYMER BARRIER CONSTRUCTION

    EPA Science Inventory

    The report examines domestic refrigerator/freezer (R/F) design alternatives which may offer greater increase in thermal performance than is possible with panel/foam composites. (NOTE: Current efforts to design and build R/Fs with high performance insulation technology are directe...

  10. The Voice of the Turtle Dove.

    ERIC Educational Resources Information Center

    Terkel, Amelia S.

    1985-01-01

    Suggests using ring doves in the classroom for observing behavior patterns and the entire reproductive cycle. Requirements for space, food, and care are minimal and easily obtained. Students can observe: male participation in nest-building; care of young; and (using candlelight) embryos and heartbeats because of the thin egg shells these birds…

  11. What determines sclerobiont colonization on marine mollusk shells?

    PubMed

    Ochi Agostini, Vanessa; Ritter, Matias do Nascimento; José Macedo, Alexandre; Muxagata, Erik; Erthal, Fernando

    2017-01-01

    Empty mollusk shells may act as colonization surfaces for sclerobionts depending on the physical, chemical, and biological attributes of the shells. However, the main factors that can affect the establishment of an organism on hard substrates and the colonization patterns on modern and time-averaged shells remain unclear. Using experimental and field approaches, we compared sclerobiont (i.e., bacteria and invertebrate) colonization patterns on the exposed shells (internal and external sides) of three bivalve species (Anadara brasiliana, Mactra isabelleana, and Amarilladesma mactroides) with different external shell textures. In addition, we evaluated the influence of the host characteristics (mode of life, body size, color alteration, external and internal ornamentation and mineralogy) of sclerobionts on dead mollusk shells (bivalve and gastropod) collected from the Southern Brazilian coast. Finally, we compared field observations with experiments to evaluate how the biological signs of the present-day invertebrate settlements are preserved in molluscan death assemblages (incipient fossil record) in a subtropical shallow coastal setting. The results enhance our understanding of sclerobiont colonization over modern and paleoecology perspectives. The data suggest that sclerobiont settlement is enhanced by (i) high(er) biofilm bacteria density, which is more attracted to surfaces with high ornamentation; (ii) heterogeneous internal and external shell surface; (iii) shallow infaunal or attached epifaunal life modes; (iv) colorful or post-mortem oxidized shell surfaces; (v) shell size (<50 mm2 or >1,351 mm2); and (vi) calcitic mineralogy. Although the biofilm bacteria density, shell size, and texture are considered the most important factors, the effects of other covarying attributes should also be considered. We observed a similar pattern of sclerobiont colonization frequency over modern and paleoecology perspectives, with an increase of invertebrates occurring on textured bivalve shells. This study demonstrates how bacterial biofilms may influence sclerobiont colonization on biological hosts (mollusks), and shows how ecological relationships in marine organisms may be relevant for interpreting the fossil record of sclerobionts.

  12. What determines sclerobiont colonization on marine mollusk shells?

    PubMed Central

    José Macedo, Alexandre; Muxagata, Erik; Erthal, Fernando

    2017-01-01

    Empty mollusk shells may act as colonization surfaces for sclerobionts depending on the physical, chemical, and biological attributes of the shells. However, the main factors that can affect the establishment of an organism on hard substrates and the colonization patterns on modern and time-averaged shells remain unclear. Using experimental and field approaches, we compared sclerobiont (i.e., bacteria and invertebrate) colonization patterns on the exposed shells (internal and external sides) of three bivalve species (Anadara brasiliana, Mactra isabelleana, and Amarilladesma mactroides) with different external shell textures. In addition, we evaluated the influence of the host characteristics (mode of life, body size, color alteration, external and internal ornamentation and mineralogy) of sclerobionts on dead mollusk shells (bivalve and gastropod) collected from the Southern Brazilian coast. Finally, we compared field observations with experiments to evaluate how the biological signs of the present-day invertebrate settlements are preserved in molluscan death assemblages (incipient fossil record) in a subtropical shallow coastal setting. The results enhance our understanding of sclerobiont colonization over modern and paleoecology perspectives. The data suggest that sclerobiont settlement is enhanced by (i) high(er) biofilm bacteria density, which is more attracted to surfaces with high ornamentation; (ii) heterogeneous internal and external shell surface; (iii) shallow infaunal or attached epifaunal life modes; (iv) colorful or post-mortem oxidized shell surfaces; (v) shell size (<50 mm2 or >1,351 mm2); and (vi) calcitic mineralogy. Although the biofilm bacteria density, shell size, and texture are considered the most important factors, the effects of other covarying attributes should also be considered. We observed a similar pattern of sclerobiont colonization frequency over modern and paleoecology perspectives, with an increase of invertebrates occurring on textured bivalve shells. This study demonstrates how bacterial biofilms may influence sclerobiont colonization on biological hosts (mollusks), and shows how ecological relationships in marine organisms may be relevant for interpreting the fossil record of sclerobionts. PMID:28902894

  13. 19. VIEW LOOKING SOUTHWEST TOWARDS THE ANCILLARY BUILDINGS. FROM LEFT ...

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

    19. VIEW LOOKING SOUTHWEST TOWARDS THE ANCILLARY BUILDINGS. FROM LEFT TO RIGHT BACKGROUND, RETORT BUILDING, STORAGE, SMELTER BUILDING, GARAGE. THE NORTHWEST CORNER OF THE VANNER ROOM IS IN THE FOREGROUND AND LEFT. A 2000 DODGE GRAND CARAVAN IS IN THE FOREGROUND CENTER. THEIR USE OF THE SHED TO THE REAR OF THE AUTOMOBILE IS UNCERTAIN, ALTHOUGH IT IS CONNECTED TO THE MILL AT THE BASE OF THE WEST SIDE OF THE AMALGAMATING PANS ROOM. - Standard Gold Mill, East of Bodie Creek, Northeast of Bodie, Bodie, Mono County, CA

  14. Limacina retroversa's response to combined effects of ocean acidification and sea water freshening

    NASA Astrophysics Data System (ADS)

    Manno, C.; Morata, N.; Primicerio, R.

    2012-11-01

    Anthropogenic carbon dioxide emissions induce ocean acidification, thereby reducing carbonate ion concentration, which may affect the ability of calcifying organisms to build shells. Pteropods, the main planktonic producers of aragonite in the worlds' oceans, may be particularly vulnerable to changes in sea water chemistry. The negative effects are expected to be most severe at high-latitudes, where natural carbonate ion concentrations are low. In this study we investigated the combined effects of ocean acidification and freshening on Limacina retroversa, the dominant pteropod in sub polar areas. Living L. retroversa, collected in Northern Norwegian Sea, were exposed to four different pH values ranging from the pre-industrial level to the forecasted end of century ocean acidification scenario. Since over the past half-century the Norwegian Sea has experienced a progressive freshening with time, each pH level was combined with a salinity gradient in two factorial, randomized experiments investigating shell degradation, swimming behavior and survival. In addition, to investigate shell degradation without any physiologic influence, one perturbation experiments using only shells of dead pteropods was performed. Lower pH reduced shell mass whereas shell dissolution increased with pCO2. Interestingly, shells of dead organisms had a higher degree of dissolution than shells of living individuals. Mortality of Limacina retroversa was strongly affected only when both pH and salinity reduced simultaneously. The combined effects of lower salinity and lower pH also affected negatively the ability of pteropods to swim upwards. Results suggest that the energy cost of maintaining ion balance and avoiding sinking (in low salinity scenario) combined with the extra energy cost necessary to counteract shell dissolution (in high pCO2 scenario), exceed the available energy budget of this organism causing the pteropods to change swimming behavior and begin to collapse. Since L. retroversa play an important role in the transport of carbonates to the deep oceans these findings have significant implications for the mechanisms influencing the inorganic carbon cycle in the sub-polar area.

  15. In-depth proteomic analysis of a mollusc shell: acid-soluble and acid-insoluble matrix of the limpet Lottia gigantea

    PubMed Central

    2012-01-01

    Background Invertebrate biominerals are characterized by their extraordinary functionality and physical properties, such as strength, stiffness and toughness that by far exceed those of the pure mineral component of such composites. This is attributed to the organic matrix, secreted by specialized cells, which pervades and envelops the mineral crystals. Despite the obvious importance of the protein fraction of the organic matrix, only few in-depth proteomic studies have been performed due to the lack of comprehensive protein sequence databases. The recent public release of the gastropod Lottia gigantea genome sequence and the associated protein sequence database provides for the first time the opportunity to do a state-of-the-art proteomic in-depth analysis of the organic matrix of a mollusc shell. Results Using three different sodium hypochlorite washing protocols before shell demineralization, a total of 569 proteins were identified in Lottia gigantea shell matrix. Of these, 311 were assembled in a consensus proteome comprising identifications contained in all proteomes irrespective of shell cleaning procedure. Some of these proteins were similar in amino acid sequence, amino acid composition, or domain structure to proteins identified previously in different bivalve or gastropod shells, such as BMSP, dermatopontin, nacrein, perlustrin, perlucin, or Pif. In addition there were dozens of previously uncharacterized proteins, many containing repeated short linear motifs or homorepeats. Such proteins may play a role in shell matrix construction or control of mineralization processes. Conclusions The organic matrix of Lottia gigantea shells is a complex mixture of proteins comprising possible homologs of some previously characterized mollusc shell proteins, but also many novel proteins with a possible function in biomineralization as framework building blocks or as regulatory components. We hope that this data set, the most comprehensive available at present, will provide a platform for the further exploration of biomineralization processes in molluscs. PMID:22540284

  16. Simulations of mechanical failure in ice: Implications of terrestrial fracture models as applied to they icy satellites of the outer solar system

    NASA Astrophysics Data System (ADS)

    Walker, C. C.; Bassis, J. N.

    2011-12-01

    At the South Pole of Enceladus, a small icy moon orbiting Saturn, is a heavily fractured ice plain surrounded by a nearly-circular mountain range. Remarkably, the Cassini orbiter detected jets of water emanating from the icy shell and into space, originating from 4 parallel "tiger stripe" rifts within the center of the ice plain. The tiger stripes imaged on Enceladus are morphologically similar to rifts observed to form under extensional stress regimes in terrestrial ice shelves; the putative subsurface ocean hypothesized beneath the icy shell strengthens the analogy that their formation may have similar mechanical origins. Past studies have also suggested that the tiger stripes are the result of a process similar to that of mid-ocean ridge spreading on the Earth, but it remains to be seen whether or not such motion is consistent with the mountainous features seen at the circular cliff-like boundary of the region. In an attempt to understand the formation of these tiger stripes and their relationship to the observed mountain chains, we apply a conceptual model in which the ice is considered to be less like a continuous fluid body and, instead, behaves like a granular material made up of discrete blocks of ice. The tidal forces on the small moon tug on the shell enough that it has been cracked many times over, motivating the assumption that the ice exists in a continuum between wholly intact ice and highly pre-fractured ice. We employ several experimental setups with the intention of mapping the deformation of the south polar segment of the shell, to determine the processes that may contribute to its observed morphological state. These setups range from large scale topographical models, e.g., simulating the build up of mountains and processes that lead to overall elevation differences in the region, to small-scale, and focus on the more detailed level of fracturing. We explore our ice-shelf rifting analogy by modeling both icy moon fracturing and ice shelf rifting to compare and contrast the failure modes that we observe, results that bolster both our comparative platform and, importantly, our understanding of fracture in ice shelves on the Earth as well. A similar approach could be applied to the chaos regions of Europa, where fractures are prevalent and whose underlying causes are not well understood.

  17. A long-term, integrated impact assessment of alternative building energy code scenarios in China

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yu, Sha; Eom, Jiyong; Evans, Meredydd

    2014-04-01

    China is the second largest building energy user in the world, ranking first and third in residential and commercial energy consumption. Beginning in the early 1980s, the Chinese government has developed a variety of building energy codes to improve building energy efficiency and reduce total energy demand. This paper studies the impact of building energy codes on energy use and CO2 emissions by using a detailed building energy model that represents four distinct climate zones each with three building types, nested in a long-term integrated assessment framework GCAM. An advanced building stock module, coupled with the building energy model, ismore » developed to reflect the characteristics of future building stock and its interaction with the development of building energy codes in China. This paper also evaluates the impacts of building codes on building energy demand in the presence of economy-wide carbon policy. We find that building energy codes would reduce Chinese building energy use by 13% - 22% depending on building code scenarios, with a similar effect preserved even under the carbon policy. The impact of building energy codes shows regional and sectoral variation due to regionally differentiated responses of heating and cooling services to shell efficiency improvement.« less

  18. Size matters: relationships between body size and body mass of common coastal, aquatic invertebrates in the Baltic Sea

    PubMed Central

    Austin, Åsa; Bergström, Ulf; Donadi, Serena; Eriksson, Britas D.H.K.; Hansen, Joakim; Sundblad, Göran

    2017-01-01

    Background Organism biomass is one of the most important variables in ecological studies, making biomass estimations one of the most common laboratory tasks. Biomass of small macroinvertebrates is usually estimated as dry mass or ash-free dry mass (hereafter ‘DM’ vs. ‘AFDM’) per sample; a laborious and time consuming process, that often can be speeded up using easily measured and reliable proxy variables like body size or wet (fresh) mass. Another common way of estimating AFDM (one of the most accurate but also time-consuming estimates of biologically active tissue mass) is the use of AFDM/DM ratios as conversion factors. So far, however, these ratios typically ignore the possibility that the relative mass of biologically active vs. non-active support tissue (e.g., protective exoskeleton or shell)—and therefore, also AFDM/DM ratios—may change with body size, as previously shown for taxa like spiders, vertebrates and trees. Methods We collected aquatic, epibenthic macroinvertebrates (>1 mm) in 32 shallow bays along a 360 km stretch of the Swedish coast along the Baltic Sea; one of the largest brackish water bodies on Earth. We then estimated statistical relationships between the body size (length or height in mm), body dry mass and ash-free dry mass for 14 of the most common taxa; five gastropods, three bivalves, three crustaceans and three insect larvae. Finally, we statistically estimated the potential influence of body size on the AFDM/DM ratio per taxon. Results For most taxa, non-linear regression models describing the power relationship between body size and (i) DM and (ii) AFDM fit the data well (as indicated by low SE and high R2). Moreover, for more than half of the taxa studied (including the vast majority of the shelled molluscs), body size had a negative influence on organism AFDM/DM ratios. Discussion The good fit of the modelled power relationships suggests that the constants reported here can be used to quickly estimate organism dry- and ash-free dry mass based on body size, thereby freeing up considerable work resources. However, the considerable differences in constants between taxa emphasize the need for taxon-specific relationships, and the potential dangers associated with ignoring body size. The negative influence of body size on the AFDM/DM ratio found in a majority of the molluscs could be caused by increasingly thicker shells with organism age, and/or spawning-induced loss of biologically active tissue in adults. Consequently, future studies utilizing AFDM/DM (and presumably also AFDM/wet mass) ratios should carefully assess the potential influence of body size to ensure more reliable estimates of organism body mass. PMID:28149685

  19. Size matters: relationships between body size and body mass of common coastal, aquatic invertebrates in the Baltic Sea.

    PubMed

    Eklöf, Johan; Austin, Åsa; Bergström, Ulf; Donadi, Serena; Eriksson, Britas D H K; Hansen, Joakim; Sundblad, Göran

    2017-01-01

    Organism biomass is one of the most important variables in ecological studies, making biomass estimations one of the most common laboratory tasks. Biomass of small macroinvertebrates is usually estimated as dry mass or ash-free dry mass (hereafter 'DM' vs. 'AFDM') per sample; a laborious and time consuming process, that often can be speeded up using easily measured and reliable proxy variables like body size or wet (fresh) mass. Another common way of estimating AFDM (one of the most accurate but also time-consuming estimates of biologically active tissue mass) is the use of AFDM/DM ratios as conversion factors. So far, however, these ratios typically ignore the possibility that the relative mass of biologically active vs. non-active support tissue (e.g., protective exoskeleton or shell)-and therefore, also AFDM/DM ratios-may change with body size, as previously shown for taxa like spiders, vertebrates and trees. We collected aquatic, epibenthic macroinvertebrates (>1 mm) in 32 shallow bays along a 360 km stretch of the Swedish coast along the Baltic Sea; one of the largest brackish water bodies on Earth. We then estimated statistical relationships between the body size (length or height in mm), body dry mass and ash-free dry mass for 14 of the most common taxa; five gastropods, three bivalves, three crustaceans and three insect larvae. Finally, we statistically estimated the potential influence of body size on the AFDM/DM ratio per taxon. For most taxa, non-linear regression models describing the power relationship between body size and (i) DM and (ii) AFDM fit the data well (as indicated by low SE and high R 2 ). Moreover, for more than half of the taxa studied (including the vast majority of the shelled molluscs), body size had a negative influence on organism AFDM/DM ratios. The good fit of the modelled power relationships suggests that the constants reported here can be used to quickly estimate organism dry- and ash-free dry mass based on body size, thereby freeing up considerable work resources. However, the considerable differences in constants between taxa emphasize the need for taxon-specific relationships, and the potential dangers associated with ignoring body size. The negative influence of body size on the AFDM/DM ratio found in a majority of the molluscs could be caused by increasingly thicker shells with organism age, and/or spawning-induced loss of biologically active tissue in adults. Consequently, future studies utilizing AFDM/DM (and presumably also AFDM/wet mass) ratios should carefully assess the potential influence of body size to ensure more reliable estimates of organism body mass.

  20. Safety studies conducted on pecan shell fiber, a food ingredient produced from ground pecan shells.

    PubMed

    Dolan, Laurie; Matulka, Ray; Worn, Jeffrey; Nizio, John

    2016-01-01

    Use of pecan shell fiber in human food is presently limited, but could increase pending demonstration of safety. In a 91-day rat study, pecan shell fiber was administered at dietary concentrations of 0 (control), 50 000, 100 000 or 150 000 ppm. There was no effect of the ingredient on body weight of males or females or food consumption of females. Statistically significant increases in food consumption were observed throughout the study in 100 000 and 150 000 ppm males, resulting in intermittent decreases in food efficiency (150 000 ppm males only) that were not biologically relevant. All animals survived and no adverse clinical signs or functional changes were attributable to the test material. There were no toxicologically relevant changes in hematology, clinical chemistry or urinalysis parameters or organ weights in rats ingesting pecan shell fiber. Any macroscopic or microscopic findings were incidental, of normal variation and/or of minimal magnitude for test substance association. Pecan shell fiber was non-mutagenic in a bacterial reverse mutation test and non-clastogenic in a mouse peripheral blood micronucleus test. Based on these results, pecan shell fiber has an oral subchronic (13-week) no observable adverse effect level (NOAEL) of 150 000 ppm in rats and is not genotoxic at the doses analyzed.

  1. Common Low-cost IM Explosive Program. Development of Next Generation Insensitive Munitions: A Success Story

    DTIC Science & Technology

    2011-11-30

    fuze separating from the shell body preventing high order detonations thus saving the lives of the Soldiers. Unit’s SPC Alan Ng  with his father Peter...Sensitive If not fully compliant, must show improvement over Baseline explosive Affordable Artillery Cost Drivers = Steel Body Material & Explosive Fill...Mortar Cost Drivers = Steel Body Material, Fuze & Propelling Charges Producible within the National Technology and Industrial Base Infrastructure

  2. Development of pressure-sensitive dosage forms with a core liquefying at body temperature.

    PubMed

    Wilde, Lisa; Bock, Mona; Wolf, Marieke; Glöckl, Gunnar; Garbacz, Grzegorz; Weitschies, Werner

    2014-04-01

    Pressure-sensitive dosage forms have been developed that are intended for pulsatile delivery of drugs to the proximal small intestine. The novel dosage forms are composed of insoluble shell and either a hard fat W32 or polyethylene glycol (PEG) 1000 core that are both liquidizing at body temperature. The release is triggered by predominant pressure waves such as contractions of the pylorus causing rupture of the shell and an immediate emptying of the liquefied filling containing the active ingredient. In consequence immediately after the trigger has been effective the total amount of the drug is intended to be available for absorption in the upper small intestine. Both core types were coated with a cellulose acetate film that creates a pressure-sensitive shell in which mechanical resistance is depending on the coating thickness. Results of the texture analysis confirmed a correlation between the polymer load of the coating and the mechanical resistance. The dissolution test performed under conditions of physiological meaningful mechanical stress showed that the drug release is triggered by pressure waves of ⩾300 mbar which are representing the maximal pressure occurring during the gastric emptying. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Field study of exhaust fans for mitigating indoor air quality problems: Final report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Grimsrud, D.T.; Szydlowski, R.F.; Turk, B.H.

    1986-09-01

    Residential ventilation in the United States housing stock is provided primarily by infiltration, the natural leakage of outdoor air into a building through cracks and holes in the building shell. Since ventilation is the dominant mechanism for control of indoor pollutant concentrations, low infiltration rates caused fluctuation in weather conditions may lead to high indoor pollutant concentrations. Supplemental mechanical ventilation can be used to eliminate these periods of low infiltration. This study examined effects of small continuously-operating exhaust fan on pollutant concentrations and energy use in residences.

  4. Signature of Europa's Ocean Density on Gravity Data

    NASA Astrophysics Data System (ADS)

    Castillo, J. C.; Rambaux, N.

    2015-12-01

    Observations by the Galileo mission at Europa and Cassini-Huygens mission at Europa, Ganymede, Callisto, Enceladus, and Titan have found deep oceans at these objects with evidence for the presence of salts. Salt compounds are the products of aqueous alteration of the rock phase under hydrothermal conditions and have been predicted theoretically for these objects per analogy with carbonaceous chondrite parent bodies. Evidence for salt enrichment comes from magnetometer measurements (Galilean satellites), direct detection in the case of Enceladus, and inversion of the gravity data obtained at Titan. While there is direct detection for the presence of chlorides in icy grains ejected from Enceladus, the chemistry of the oceans detected so far, or even their densities, remain mostly unconstrained. However the increased ocean density impacts the interpretation of the tidal Love number k2and this may introduce confusion in the inference of the icy shell thickness from that parameter. We will present estimates of k2for a range of assumptions on Europa's hydrospheric structure that build on geophysical observations obtained by the Galileo mission combined with new models of Europa's interior. These models keep track of the compositions of the hydrated core and oceanic composition in a self-consistent manner. We will also estimate the electrical conductivity corresponding to the modeled oceanic composition. Finally we will explore how combining electromagnetic, topographic, and gravity data can decouple the signatures of the shell thickness and ocean composition on these geophysical observations. Acknowledgement: This work is being carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract to NASA. Government sponsorship acknowledged.

  5. Ab initio treatment of fully open-shell medium-mass nuclei with the IM-SRG

    NASA Astrophysics Data System (ADS)

    Stroberg, Ragnar; Calci, Angelo; Holt, Jason; Navratil, Petr; Bogner, Scott; Hergert, Heiko; Roth, Robert; Schwenk, Achim

    2016-09-01

    The in-medium similarity renormalization group (IM-SRG) is a recently-developed theoretical many-body framework which - like the coupled cluster and the self-consistent Green's function approaches - allows for the treatment of medium-mass nuclei using interactions fit at the few-body level. I will give a brief overview of how the IM-SRG may be used to decouple a shell-model type valence space. I will then describe a recent development for the approximate treatment of residual 3N forces in the valence space which extends the reach of IM-SRG to essentially all medium-mass nuclei, and I will present some selected results spanning isotopic chains from beryllium (Z=4) to nickel (Z=28). Finally, I will discuss the consistent treatment of transition operators, highlighting the potential for future applications in electroweak physics.

  6. Alternative Reproductive Tactics in the Shell-Brooding Lake Tanganyika Cichlid Neolamprologus brevis

    PubMed Central

    Ota, Kazutaka; Aibara, Mitsuto; Morita, Masaya; Awata, Satoshi; Hori, Michio; Kohda, Masanori

    2012-01-01

    Alternative reproductive tactics (ARTs) are found in several Lake Tanganyika shell-brooding cichlids. Field studies were conducted in the Wonzye population to examine reproductive ecology and ARTs in the Lake Tanganyika shell-brooding cichlid Neolamprologus brevis. We discovered that this fish occurred in both rocky- and sandy-bottom habitats, but in rocky habitats, brood-caring females exclusively occurred in shell-patches that another cichlid species created. All N. brevis of both sexes in the patches were sexually mature, whereas immature males and females with unripe eggs were found frequently in sandy-bottom habitats. Males in sandy-bottom habitats were smaller, but fed more frequently and were in better somatic condition than males in the patches. Similar tendency was found in females. This indicates that N. brevis uses different habitats depending on the stage of its life history, with migration from sandy-bottom habitats to the shell-patches for reproduction. Males in the patches exhibited different behavior patterns: floating above the patches and lying in the patches. The former was larger, more aggressive, and invested less in gonads (relative to body size) than the latter. These results accord with those of other shell-brooding Lake Tanganyika cichlids with ARTs, and they therefore suggest the presence of ARTs in N. brevis. PMID:22888463

  7. The argonaut shell: gas-mediated buoyancy control in a pelagic octopus

    PubMed Central

    Finn, Julian K.; Norman, Mark D.

    2010-01-01

    Argonauts (Cephalopoda: Argonautidae) are a group of rarely encountered open-ocean pelagic octopuses with benthic ancestry. Female argonauts inhabit a brittle ‘paper nautilus’ shell, the role of which has puzzled naturalists for millennia. The primary role attributed to the shell has been as a receptacle for egg deposition and brooding. Our observations of wild argonauts have revealed that the thin calcareous shell also functions as a hydrostatic structure, employed by the female argonaut to precisely control buoyancy at varying depths. Female argonauts use the shell to ‘gulp’ a measured volume of air at the sea surface, seal off the captured gas using flanged arms and forcefully dive to a depth where the compressed gas buoyancy counteracts body weight. This process allows the female argonaut to attain neutral buoyancy at depth and potentially adjust buoyancy to counter the increased (and significant) weight of eggs during reproductive periods. Evolution of this air-capture strategy enables this negatively buoyant octopus to survive free of the sea floor. This major shift in life mode from benthic to pelagic shows strong evolutionary parallels with the origins of all cephalopods, which attained gas-mediated buoyancy via the closed-chambered shells of the true nautiluses and their relatives. PMID:20484241

  8. Selective cytotoxicity of PAMAM G5 core–PAMAM G2.5 shell tecto-dendrimers on melanoma cells

    PubMed Central

    Schilrreff, Priscila; Mundiña-Weilenmann, Cecilia; Romero, Eder Lilia; Morilla, Maria Jose

    2012-01-01

    Background The controlled introduction of covalent linkages between dendrimer building blocks leads to polymers of higher architectural order known as tecto-dendrimers. Because of the few simple steps involved in their synthesis, tecto-dendrimers could expand the portfolio of structures beyond commercial dendrimers, due to the absence of synthetic drawbacks (large number of reaction steps, excessive monomer loading, and lengthy chromatographic separations) and structural constraints of high-generation dendrimers (reduction of good monodispersity and ideal dendritic construction due to de Gennes dense-packing phenomenon). However, the biomedical uses of tecto-dendrimers remain unexplored. In this work, after synthesizing saturated shell core–shell tecto-dendrimers using amine-terminated polyamidoamine (PAMAM) generation 5 (G5) as core and carboxyl-terminated PAMAM G2.5 as shell (G5G2.5 tecto-dendrimers), we surveyed for the first time the main features of their interaction with epithelial cells. Methods Structural characterization of G5G2.5 was performed by polyacrylamide gel electrophoresis, matrix-assisted laser desorption time-of-flight mass spectrometry, and microscopic techniques; their hydrodynamic size and Z-potential was also determined. Cellular uptake by human epidermal keratinocytes, colon adenocarcinoma, and epidermal melanoma (SK-Mel-28) cells was determined by flow cytometry. Cytotoxicity was determined by mitochondrial activity, lactate dehydrogenase release, glutathione depletion, and apoptosis/necrosis measurement. Results The resultant 60%–67% saturated shell, 87,000-dalton G5G2.5 (mean molecular weight) interacted with cells in a significantly different fashion in comparison to their building blocks and to its closest counterpart, PAMAM G6.5. After being actively taken up by epithelial cells, G5G2.5 caused cytotoxicity only on SK-Mel-28 cells, including depletion of intracellular glutathione and fast necrosis that was manifested above 5 μM G5G2.5. It cannot be discounted that traces of LiCl within G5G2.5 were involved in such deleterious effects. Conclusion These preliminary results suggest that at concentrations that do not damage healthy keratinocytes, G5G2.5 could display antimelanoma activity. PMID:22904625

  9. A feasibility study of altered spatial distribution of losses induced by eddy currents in body composition analysis

    PubMed Central

    2010-01-01

    Background Tomographic imaging has revealed that the body mass index does not give a reliable state of overall fitness. However, high measurement costs make the tomographic imaging unsuitable for large scale studies or repeated individual use. This paper reports an experimental investigation of a new electromagnetic method and its feasibility for assessing body composition. The method is called body electrical loss analysis (BELA). Methods The BELA method uses a high-Q parallel resonant circuit to produce a time-varying magnetic field. The Q of the resonator changes when the sample is placed in its coil. This is caused by induced eddy currents in the sample. The new idea in the BELA method is the altered spatial distribution of the electrical losses generated by these currents. The distribution of losses is varied using different excitation frequencies. The feasibility of the method was tested using simplified phantoms. Two of these phantoms were rough estimations of human torso. One had fat in the middle of its volume and saline solution in the outer shell volume. The other had reversed conductivity distributions. The phantoms were placed in the resonator and the change in the losses was measured. Five different excitation frequencies from 100 kHz to 200 kHz were used. Results The rate of loss as a function of frequency was observed to be approximately three times larger for a phantom with fat in the middle of its volume than for one with fat in its outer shell volume. Conclusions At higher frequencies the major signal contribution can be shifted toward outer shell volume. This enables probing the conductivity distribution of the subject by weighting outer structural components. The authors expect that the loss changing rate over frequency can be a potential index for body composition analysis. PMID:21047441

  10. [Thermal tolerance, diel variation of body temperature, and thermal dependence of locomotor performance of hatchling soft-shelled turtles, Trionyx sinensis].

    PubMed

    Sun, Pingyue; Xu, Xiaoyin; Chen, Huili; Ji, Xiang

    2002-09-01

    The thermal tolerance, body temperature, and influence of temperature on locomotor performance of hatchling soft-shelled turtles (Trionyx sinensis) were studied under dry and wet conditions, and the selected body temperature of hatchlings was 28.0 and 30.3 degrees C, respectively. Under wet condition, the critical thermal maximum and minimum averaged 40.9 and 7.8 degrees C, respectively. In the environments without thermal gradients, the diel variation of body temperature was highly consistent with the variation of both air and water temperatures, and the body temperature was more directly affected by water temperature than by air temperature, which implied that the physiological thermoregulation of hatchling T. sinensis was very weak. In the environments with thermal gradients, hatchling turtles could maintain relatively high and constant body temperatures, primarily through behavioral thermoregulation. The locomotor performance of hatchling turtles was highly dependent on their body temperature. Within a certain range, the locomotor performance increased with increasing body temperature. In our study, the optimal body temperature for locomotor performance was 31.5 degrees C, under which, the maximum continuous running distance, running distance per minute, and number of stops per minute averaged 1.87 m, 4.92 m.min-1, and 6.2 times.min-1, respectively. The correspondent values at 33.0 degrees C averaged 1.30 m, 4.28 m.min-1, and 7.7 times.min-1, respectively, which indicated that the locomotor performance of hatchling turtles was impaired at 33.0 degrees C. Therefore, extremely high body temperatures might have an adverse effect on locomotor performance of hatchling turtles.

  11. Food Supply and Seawater pCO2 Impact Calcification and Internal Shell Dissolution in the Blue Mussel Mytilus edulis

    PubMed Central

    Melzner, Frank; Stange, Paul; Trübenbach, Katja; Thomsen, Jörn; Casties, Isabel; Panknin, Ulrike; Gorb, Stanislav N.; Gutowska, Magdalena A.

    2011-01-01

    Progressive ocean acidification due to anthropogenic CO2 emissions will alter marine ecosytem processes. Calcifying organisms might be particularly vulnerable to these alterations in the speciation of the marine carbonate system. While previous research efforts have mainly focused on external dissolution of shells in seawater under saturated with respect to calcium carbonate, the internal shell interface might be more vulnerable to acidification. In the case of the blue mussel Mytilus edulis, high body fluid pCO2 causes low pH and low carbonate concentrations in the extrapallial fluid, which is in direct contact with the inner shell surface. In order to test whether elevated seawater pCO2 impacts calcification and inner shell surface integrity we exposed Baltic M. edulis to four different seawater pCO2 (39, 142, 240, 405 Pa) and two food algae (310–350 cells mL−1 vs. 1600–2000 cells mL−1) concentrations for a period of seven weeks during winter (5°C). We found that low food algae concentrations and high pCO2 values each significantly decreased shell length growth. Internal shell surface corrosion of nacreous ( = aragonite) layers was documented via stereomicroscopy and SEM at the two highest pCO2 treatments in the high food group, while it was found in all treatments in the low food group. Both factors, food and pCO2, significantly influenced the magnitude of inner shell surface dissolution. Our findings illustrate for the first time that integrity of inner shell surfaces is tightly coupled to the animals' energy budget under conditions of CO2 stress. It is likely that under food limited conditions, energy is allocated to more vital processes (e.g. somatic mass maintenance) instead of shell conservation. It is evident from our results that mussels exert significant biological control over the structural integrity of their inner shell surfaces. PMID:21949698

  12. Radar attenuation in Europa's ice shell: obstacles and opportunities for constraining shell thickness and thermal structure

    NASA Astrophysics Data System (ADS)

    Kalousova, Klara; Schroeder, Dustin M.; Soderlund, Krista M.; Sotin, Christophe

    2016-10-01

    With its strikingly young surface and possibly recent endogenic activity, Europa is one of the most exciting bodies within our Solar System and a primary target for spacecraft exploration. Future missions to Europa are expected to carry ice penetrating radar instruments which are powerful tools to investigate the subsurface thermophysical structure of its ice shell.Several authors have addressed the 'penetration depth' of radar sounders at icy moons, however, the concept and calculation of a single value penetration depth is a potentially misleading simplification since it ignores the thermal and attenuation structure complexity of a realistic ice shell. Here we move beyond the concept of a single penetration depth by exploring the variation in two-way radar attenuation for a variety of potential thermal structures of Europa's ice shell as well as for a low loss and high loss temperature-dependent attenuation model. The possibility to detect brines is also investigated.Our results indicate that: (i) for all ice shell thicknesses investigated (5-30 km), a nominal satellite-borne radar sounder will penetrate between 15% and 100% of the total thickness, (ii) the maximum penetration depth strongly varies laterally with the deepest penetration possible through the cold downwellings, (iii) the direct detection of the ice/ocean interface might be possible for shells of up to 15 km if the radar signal travels through the cold downwelling, (iv) even if the ice/ocean interface is not detected, the penetration through most of the shell could constrain the deep shell structure through the loss of signal, and (v) for all plausible ice shells the two-way attenuation to the eutectic point is ≤30 dB which shows a robust potential for longitudinal investigation of the ice shell's shallow structure.Part of this work has been performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract to NASA. K.K. acknowledges support by the Grant Agency of the Czech Republic through project 15-14263Y.

  13. Food supply and seawater pCO2 impact calcification and internal shell dissolution in the blue mussel Mytilus edulis.

    PubMed

    Melzner, Frank; Stange, Paul; Trübenbach, Katja; Thomsen, Jörn; Casties, Isabel; Panknin, Ulrike; Gorb, Stanislav N; Gutowska, Magdalena A

    2011-01-01

    Progressive ocean acidification due to anthropogenic CO(2) emissions will alter marine ecosystem processes. Calcifying organisms might be particularly vulnerable to these alterations in the speciation of the marine carbonate system. While previous research efforts have mainly focused on external dissolution of shells in seawater under saturated with respect to calcium carbonate, the internal shell interface might be more vulnerable to acidification. In the case of the blue mussel Mytilus edulis, high body fluid pCO(2) causes low pH and low carbonate concentrations in the extrapallial fluid, which is in direct contact with the inner shell surface. In order to test whether elevated seawater pCO(2) impacts calcification and inner shell surface integrity we exposed Baltic M. edulis to four different seawater pCO(2) (39, 142, 240, 405 Pa) and two food algae (310-350 cells mL(-1) vs. 1600-2000 cells mL(-1)) concentrations for a period of seven weeks during winter (5°C). We found that low food algae concentrations and high pCO(2) values each significantly decreased shell length growth. Internal shell surface corrosion of nacreous ( = aragonite) layers was documented via stereomicroscopy and SEM at the two highest pCO(2) treatments in the high food group, while it was found in all treatments in the low food group. Both factors, food and pCO(2), significantly influenced the magnitude of inner shell surface dissolution. Our findings illustrate for the first time that integrity of inner shell surfaces is tightly coupled to the animals' energy budget under conditions of CO(2) stress. It is likely that under food limited conditions, energy is allocated to more vital processes (e.g. somatic mass maintenance) instead of shell conservation. It is evident from our results that mussels exert significant biological control over the structural integrity of their inner shell surfaces.

  14. VIEW OF A BODY COUNTING ROOM IN BUILDING 122. BODY ...

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

    VIEW OF A BODY COUNTING ROOM IN BUILDING 122. BODY COUNTING MEASURES RADIOACTIVE MATERIAL IN THE BODY. DESIGNED TO MINIMIZE EXTERNAL SOURCES OF RADIATION, BODY COUNTING ROOMS ARE CONSTRUCTED OF PRE-WORLD WAR II (WWII) STEEL. PRE-WWII STEEL, WHICH HAS NOT BEEN AFFECTED BY NUCLEAR FALLOUT, IS LOWER IS RADIOACTIVITY THAN STEEL CREATED AFTER WWII. (10/25/85) - Rocky Flats Plant, Emergency Medical Services Facility, Southwest corner of Central & Third Avenues, Golden, Jefferson County, CO

  15. Porter-Thomas distribution in unstable many-body systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Volya, Alexander

    We use the continuum shell model approach to explore the resonance width distribution in unstable many-body systems. The single-particle nature of a decay, the few-body character of the interaction Hamiltonian, and the collectivity that emerges in nonstationary systems due to the coupling to the continuum of reaction states are discussed. Correlations between the structures of the parent and daughter nuclear systems in the common Fock space are found to result in deviations of decay width statistics from the Porter-Thomas distribution.

  16. Adolescent Attractiveness Standards for Self and Significant Other.

    ERIC Educational Resources Information Center

    Papini, Dennis R.

    Previous research investigating the relationship between body build and personality stereotypes found that the mesomorphic build was attributed positive qualities while the endomorph and ectomorph were assigned negative qualities by both males and females. More recent research has revealed a potential shift in body build preferences as standards…

  17. Skirmishing around Carlisle - 1863,

    DTIC Science & Technology

    1986-04-01

    planned to accompany the column, was held up at Brioqepr,-t most of the day by the uniil ingness of the I lth Heavu Artillery e ,. US_ Volunteers to join...34 enough to have their property struck by a shell later placed small metal plaques or, their buildings that read., "July 1, 1863." At Carlisle Barracks

  18. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Reidel, Stephen P.; Chamness, Mickie A.

    This data package discusses the geology of the single-shell tank (SST) farms and the geologic history of the area. The purpose of this report is to provide the most recent geologic information available for the SST farms. This report builds upon previous reports on the tank farm geology and Integrated Disposal Facility geology with information available after those reports were published.

  19. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Reidel, Steve P.; Chamness, Mickie A.

    This data package discusses the geology of the single-shell tank (SST) farms and the geologic history of the area. The focus of this report is to provide the most recent geologic information available for the SST farms. This report builds upon previous reports on the tank farm geology and Integrated Disposal Facility geology with information available after those reports were published.

  20. Singlet-paired coupled cluster theory for open shells

    NASA Astrophysics Data System (ADS)

    Gomez, John A.; Henderson, Thomas M.; Scuseria, Gustavo E.

    2016-06-01

    Restricted single-reference coupled cluster theory truncated to single and double excitations accurately describes weakly correlated systems, but often breaks down in the presence of static or strong correlation. Good coupled cluster energies in the presence of degeneracies can be obtained by using a symmetry-broken reference, such as unrestricted Hartree-Fock, but at the cost of good quantum numbers. A large body of work has shown that modifying the coupled cluster ansatz allows for the treatment of strong correlation within a single-reference, symmetry-adapted framework. The recently introduced singlet-paired coupled cluster doubles (CCD0) method is one such model, which recovers correct behavior for strong correlation without requiring symmetry breaking in the reference. Here, we extend singlet-paired coupled cluster for application to open shells via restricted open-shell singlet-paired coupled cluster singles and doubles (ROCCSD0). The ROCCSD0 approach retains the benefits of standard coupled cluster theory and recovers correct behavior for strongly correlated, open-shell systems using a spin-preserving ROHF reference.

  1. Synthesis of core-shell iron nanoparticles via a new (novel) approach

    NASA Astrophysics Data System (ADS)

    Chaudhary, Rakesh P.; Koymen, Ali R.

    2014-03-01

    Carbon-encapsulated iron (Fe) nanoparticles were synthesized by a newly developed method in toluene. Transmission Electron Microscopy (TEM) and High Resolution Transmission Electron Microscopy (HRTEM) of the as prepared sample reveal that core-shell nanostructures have been formed with Fe as core and graphitic carbon as shell. Fe nanoparticles with diameter 11nm to 102 nm are encapsulated by 6-8 nm thick graphitic carbon layers. There was no iron carbide formation observed between the Fe core and the graphitic shell. The Fe nanoparticles have body centered cubic (bcc) crystal structure. The magnetic hysteresis loop of the as synthesized powder at room temperature showed a saturation magnetization of 9 Am2 kg-1. After thermal treatment crystalline order of the samples improved and hence saturation magnetization increased to 24 Am2kg-1. We foresee that the carbon-encapsulated Fe nanoparticles are biologically friendly and could have potential applications in Magnetic Resonance Imaging (MRI) and Photothermal cancer therapy.

  2. Symbolic use of marine shells and mineral pigments by Iberian Neandertals

    PubMed Central

    Zilhão, João; Angelucci, Diego E.; Badal-García, Ernestina; d’Errico, Francesco; Daniel, Floréal; Dayet, Laure; Douka, Katerina; Higham, Thomas F. G.; Martínez-Sánchez, María José; Montes-Bernárdez, Ricardo; Murcia-Mascarós, Sonia; Pérez-Sirvent, Carmen; Roldán-García, Clodoaldo; Vanhaeren, Marian; Villaverde, Valentín; Wood, Rachel; Zapata, Josefina

    2010-01-01

    Two sites of the Neandertal-associated Middle Paleolithic of Iberia, dated to as early as approximately 50,000 years ago, yielded perforated and pigment-stained marine shells. At Cueva de los Aviones, three umbo-perforated valves of Acanthocardia and Glycymeris were found alongside lumps of yellow and red colorants, and residues preserved inside a Spondylus shell consist of a red lepidocrocite base mixed with ground, dark red-to-black fragments of hematite and pyrite. A perforated Pecten shell, painted on its external, white side with an orange mix of goethite and hematite, was abandoned after breakage at Cueva Antón, 60 km inland. Comparable early modern human-associated material from Africa and the Near East is widely accepted as evidence for body ornamentation, implying behavioral modernity. The Iberian finds show that European Neandertals were no different from coeval Africans in this regard, countering genetic/cognitive explanations for the emergence of symbolism and strengthening demographic/social ones. PMID:20080653

  3. Empirical calibration of shell chemistry of Cyprideis torosa (Jones, 1850) (Crustacea: Ostracoda)

    NASA Astrophysics Data System (ADS)

    Marco-Barba, J.; Ito, E.; Carbonell, E.; Mesquita-Joanes, F.

    2012-09-01

    Cyprideis torosa is a species of ostracode that inhabits a wide range of aquatic habitats in which its low Alk/Ca requirement is met. Its fossil remains are widely used in palaeoecological studies of coastal environments and inland salt lakes. We collected C. torosa from 20 water bodies near Valencia, Spain. Temperature, chlorophyll a concentration, electrical conductivity, and the concentration of major ions and oxygen isotopes were measured at each site. Between 2 and 20 live individuals of C. torosa were collected per site, their instar stage and sex determined and their shell chemistry (Mg/Ca, Sr/Ca and carbon and oxygen isotope composition) analyzed. Three of these sites were sampled monthly for one year, and ostracode population structure and shell chemistry (20-40 shells) were analyzed. The water chemistry varied widely between sites. TDS (total dissolved solids) ranged from 0.5 to 71.8 g/L but chloride was always the dominant anion. There is a significant positive relationship between ostracode and water δ18O except at high TDS (>20 g/L) when shell δ18O values are lower than expected. No effect of either temperature or water Mg/Ca is observed on the Mg/Ca in the ostracode calcite in waters with Mg/Ca < 6 (molar ratio). Ostracode shell Sr/Ca is strongly and significantly related to water Sr/Ca. δ13C values in C. torosa shells are ˜2‰ lower than observed δ13CDIC. These results provide new and more accurate quantification tools to reconstruct past hydrochemistry from C. torosa shells.

  4. Health-hazard evaluation report HETA 91-298-2182, Gibson Flatiron, Erica Shell Manufacturing, Bozeman, Montana

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    McCammon, C.S.

    1992-02-01

    In response to a request from the Montana State Health Department, an evaluation was undertaken of exposures to wood dust and lacquer vapors at the Gibson Flatiron/Erica Shell Manufacturing Companies (SIC-3931), Bozeman, Montana. Gibson Flatiron manufactured mandolins and banjoes. Erica Shell Manufacturing Company cuts and grinds abalone and other sea shells into small pieces to be used in designs inlayed into mandolins and banjos. Measured wood dust levels ranged from 0.8 to 32mg/cu m with an 8 hour time weighted average (TWA) of 1.2 to 30mg/cu m. Rib construction and assembly, and planing bulk ebony wood had TWA exposures abovemore » the OSHA permissible exposure limit of 5mg/cu m for wood dust. Application of dyes and finishes resulted in low exposures to acetone (67641), toluene (108883), xylene (1330207), and butyl-acetate (123864). No solvent air concentrations were above 10% of their respective PELs. The author concludes that a health hazard existed for exposure to wood dusts. The author recommends the establishment of a respiratory protection program and a hearing conservation program. Emergency egress routes should be marked in the buildings.« less

  5. ScienceCast 38: The Great Lakes of Europa

    NASA Image and Video Library

    2011-11-23

    Scientists studying data from NASA's Galileo probe have discovered what appears to be a body of liquid water the volume of the North American Great Lakes locked inside the icy shell of Jupiter's moon Europa.

  6. Hollow-Wall Heat Shield for Fuel Injector Component

    NASA Technical Reports Server (NTRS)

    Hanson, Russell B. (Inventor)

    2018-01-01

    A fuel injector component includes a body, an elongate void and a plurality of bores. The body has a first surface and a second surface. The elongate void is enclosed by the body and is integrally formed between portions of the body defining the first surface and the second surface. The plurality of bores extends into the second surface to intersect the elongate void. A process for making a fuel injector component includes building an injector component body having a void and a plurality of ports connected to the void using an additive manufacturing process that utilizes a powdered building material, and removing residual powdered building material from void through the plurality of ports.

  7. Secondary ion mass spectra of gold super clusters up to 140000 Dalton

    NASA Astrophysics Data System (ADS)

    Feld, H.; Leute, A.; Rading, D.; Benninghoven, A.; Schmid, G.

    1990-03-01

    The bombardment of a two-shell gold complex (Au55(PPh3)12Cl6) with 10 keV Xe+-ions results in the formation of secondary ion masses up to 140000 u. These are by far the largest secondary ions observed under primary particle bombardment. The detection and identification of these ions with a Time-Of-Flight Secondary Ion Mass Spectrometer (TOF-SIMS) gives important information about the behavior of naked full-shell clusters. Au13 particles, generated from the Au55 cluster, serve as building blocks for a series of super-clusters up to (Au13)55. The results for keV-ion bombardment are compared to those for MeV-ion bombardment.

  8. Electrostatics-driven shape transitions in soft shells.

    PubMed

    Jadhao, Vikram; Thomas, Creighton K; Olvera de la Cruz, Monica

    2014-09-02

    Manipulating the shape of nanoscale objects in a controllable fashion is at the heart of designing materials that act as building blocks for self-assembly or serve as targeted drug delivery carriers. Inducing shape deformations by controlling external parameters is also an important way of designing biomimetic membranes. In this paper, we demonstrate that electrostatics can be used as a tool to manipulate the shape of soft, closed membranes by tuning environmental conditions such as the electrolyte concentration in the medium. Using a molecular dynamics-based simulated annealing procedure, we investigate charged elastic shells that do not exchange material with their environment, such as elastic membranes formed in emulsions or synthetic nanocontainers. We find that by decreasing the salt concentration or increasing the total charge on the shell's surface, the spherical symmetry is broken, leading to the formation of ellipsoids, discs, and bowls. Shape changes are accompanied by a significant lowering of the electrostatic energy and a rise in the surface area of the shell. To substantiate our simulation findings, we show analytically that a uniformly charged disc has a lower Coulomb energy than a sphere of the same volume. Further, we test the robustness of our results by including the effects of charge renormalization in the analysis of the shape transitions and find the latter to be feasible for a wide range of shell volume fractions.

  9. Petrology and geochemistry of the orbicular granitoid of Caldera, northern Chile. Models and hypotheses on the formation of radial orbicular textures

    NASA Astrophysics Data System (ADS)

    Díaz-Alvarado, Juan; Rodríguez, Natalia; Rodríguez, Carmen; Fernández, Carlos; Constanzo, Ítalo

    2017-07-01

    The orbicular granitoid of Caldera, located at the northern part of the Chilean Coastal Range, is a spectacular example of radial textures in orbicular structures. The orbicular body crops out as a 375 m2 tabular to lensoidal intrusive sheet emplaced in the Lower Jurassic Relincho pluton. The orbicular structures are 3-7 cm in diameter ellipsoids hosted in a porphyritic matrix. The orbicules are comprised by a Qtz-dioritic core (3-5 cm in diameter) composed by Pl + Hbl + Qtz + Bt ± Kfs with equiaxial textures and a gabbroic shell (2-3 cm in diameter) characterized by feathery and radiate textures with a plagioclase + hornblende paragenesis. The radial shell crystals are rooted and orthogonally disposed in the irregular contact with the core. The radial shell, called here inner shell, is in contact with the granodioritic equiaxial interorbicular matrix through a 2-3 mm wide poikilitic band around the orbicule (outer shell). The outer shell and the matrix surrounding the orbicules are characterized by the presence of large hornblende and biotite oikocrystals that include fine-grained rounded plagioclase and magnetite. The oikocrystals of both the outer shell and the matrix have a circumferential arrangement around the orbicule, i.e. orthogonal to the radial inner shell. The coarse-grained granodioritic interorbicular matrix present pegmatitic domains with large acicular hornblende and K-feldspar megacrysts. This work presents a review of the textural characteristics of the orbicules and a complete new mineral and whole-rock geochemical study of the different parts of the orbicular granitoid, together with thermobarometric and crystallographic data, and theoretical modeling of the crystallization and element partitioning processes. We propose a model for the formation of the orbicular radial textures consisting of several processes that are suggested to occur fast and consecutively: superheating, volatile exsolution, undercooling, geochemical fractionation and columnar and equiaxial crystallization. According to the obtained results, the formation of the orbicular granitoid of Caldera may have initiated 1) during the generation of a magmatic fracture in the crystallization front of the Relincho pluton, where the water released by the host crystal mush was dissolved in the new batch of dioritic magma. 2) The high influx of water-rich liquids induced superheating conditions in the newly intruding magma that became a depolymerized liquid, where the only solid particules were the small irregular fragments of the host mush dragged from the fracture walls. 3) Volatile exsolution promoted crystallization under undercooling conditions. 4) Undercooling and nucleation around the core (cold germs) involved the physical and geochemical fractionation between two sub-systems: a gabbroic sub-system that comprises the solid paragénesis with a residual water-rich liquid and a granodioritic sub-system. 5) The orbicules, including core and inner shell, behaved as viscous bodies (crystals + residual liquid) floating in the granodioritic magma. 6) Higher undercooling rates occurred at the starting stage, close to the liquidus, promoting columnar crystallization around the cores and formation of the shells. Conversely, in the granodioritic matrix sub-system, equiaxial crystallization was promoted by low relative crystallization rates. 7) The rest of the crystallization process evolved later in the outer shell and the matrix, as suggested by the poikilitic textures observed in both sides of the orbicule contact, and under conditions close to the solidus of both sub-systems (shell and matrix). The water-rich residual liquid expelled during the orbicular shell crystallization was mingled with the partially crystallized matrix magma, generating the pegmatitic domains with large Kfs megacrysts.

  10. Vanishing Clams on an Iberian Beach: Local Consequences and Global Implications of Accelerating Loss of Shells to Tourism

    PubMed Central

    Kowalewski, Michał; Domènech, Rosa; Martinell, Jordi

    2014-01-01

    Multi-decadal increase in shell removal by tourists, a process that may accelerate degradation of natural habitats, was quantified via two series of monthly surveys, conducted thirty years apart (1978–1981 and 2008–2010) in one small embayment on the Mediterranean coast of the Iberian Peninsula. Over the last three decades, the local tourist arrivals have increased almost three-fold (2.74), while the area has remained unaffected by urban encroachment and commercial fisheries. During the same time interval the abundance of mollusk shells along the shoreline decreased by a comparable factor (2.62) and was significantly and negatively correlated with tourist arrivals (r = −0.52). The strength of the correlation increased when data were restricted to months with high tourist arrivals (r = −0.72). In contrast, the maximum monthly wave energy (an indirect proxy for changes in rate of onshore shell transport) was not significantly correlated with shell abundance (r = 0.10). Similarly, rank dominance of common species, drilling predation intensity, and body size-frequency distribution patterns have all remained stable over recent decades. A four-fold increase in global tourist arrivals over the last 30 years may have induced a comparable worldwide acceleration in shell removal from marine shorelines, resulting in multiple, currently unquantifiable, habitat changes such as increased beach erosion, changes in calcium carbonate recycling, and declines in diversity and abundance of organisms, which are dependent on shell availability. PMID:24421895

  11. Vanishing clams on an Iberian beach: local consequences and global implications of accelerating loss of shells to tourism.

    PubMed

    Kowalewski, Michał; Domènech, Rosa; Martinell, Jordi

    2014-01-01

    Multi-decadal increase in shell removal by tourists, a process that may accelerate degradation of natural habitats, was quantified via two series of monthly surveys, conducted thirty years apart (1978-1981 and 2008-2010) in one small embayment on the Mediterranean coast of the Iberian Peninsula. Over the last three decades, the local tourist arrivals have increased almost three-fold (2.74), while the area has remained unaffected by urban encroachment and commercial fisheries. During the same time interval the abundance of mollusk shells along the shoreline decreased by a comparable factor (2.62) and was significantly and negatively correlated with tourist arrivals (r = -0.52). The strength of the correlation increased when data were restricted to months with high tourist arrivals (r = -0.72). In contrast, the maximum monthly wave energy (an indirect proxy for changes in rate of onshore shell transport) was not significantly correlated with shell abundance (r = 0.10). Similarly, rank dominance of common species, drilling predation intensity, and body size-frequency distribution patterns have all remained stable over recent decades. A four-fold increase in global tourist arrivals over the last 30 years may have induced a comparable worldwide acceleration in shell removal from marine shorelines, resulting in multiple, currently unquantifiable, habitat changes such as increased beach erosion, changes in calcium carbonate recycling, and declines in diversity and abundance of organisms, which are dependent on shell availability.

  12. Phase field modeling of brittle fracture for enhanced assumed strain shells at large deformations: formulation and finite element implementation

    NASA Astrophysics Data System (ADS)

    Reinoso, J.; Paggi, M.; Linder, C.

    2017-06-01

    Fracture of technological thin-walled components can notably limit the performance of their corresponding engineering systems. With the aim of achieving reliable fracture predictions of thin structures, this work presents a new phase field model of brittle fracture for large deformation analysis of shells relying on a mixed enhanced assumed strain (EAS) formulation. The kinematic description of the shell body is constructed according to the solid shell concept. This enables the use of fully three-dimensional constitutive models for the material. The proposed phase field formulation integrates the use of the (EAS) method to alleviate locking pathologies, especially Poisson thickness and volumetric locking. This technique is further combined with the assumed natural strain method to efficiently derive a locking-free solid shell element. On the computational side, a fully coupled monolithic framework is consistently formulated. Specific details regarding the corresponding finite element formulation and the main aspects associated with its implementation in the general purpose packages FEAP and ABAQUS are addressed. Finally, the applicability of the current strategy is demonstrated through several numerical examples involving different loading conditions, and including linear and nonlinear hyperelastic constitutive models.

  13. Determination on the chemical composition of Ammonia beccarii shell using SEM and EDX: Preliminary study of benthic foraminifera capacity in response to anthropogenic metal contamination in coastal areas

    NASA Astrophysics Data System (ADS)

    Rositasari, R.; Suratno; Yogaswara, D.

    2018-02-01

    The use of single-celled and shelled biota, such as foraminifera that lives as benthic, in coastal environmental monitoring activity is very efficient. Several species of the Ammonia have been used as a proxy of various aquatic environmental monitoring activities. Chemical constituents screening in foraminiferal shell is a step ahead to identify the capacity of benthic foraminifera in responding to anthropogenic metal contamination in coastal water areas. The initial hypothesis of this study is the calcite test of Ammonia beccarii binds the anthropogenic metal in its shell structure and triggers the deformation test. The normal and abnormal shells of Ammonia specimens from Jakarta Bay and Batam waters are used in this study. The Ponar grab was used to sample surface sediment in Jakarta Bay and Batam waters in 2015, and the short core was used to acquire substratum sediment in Jakarta Bay in 2011.The Ammonia beccarii shell was analyzed using SEM and EDX detectors (Scanning Electron Microscope and Energy Dispersive X-ray). The shooting was performed three times in each test, i.e. in the first chamber (proloculus), the last chamber and the chamber between the two. The main building blocks of the foraminifera test are oxygen with an average weight range of 42.86 - 58.79% and carbon with an average weight range of 17.69 - 26.32%. There is a tendency for low levels of C and O elements in the abnormal tests.

  14. Nanoscale semiconductor-insulator-metal core/shell heterostructures: facile synthesis and light emission

    NASA Astrophysics Data System (ADS)

    Li, Gong Ping; Chen, Rui; Guo, Dong Lai; Wong, Lai Mun; Wang, Shi Jie; Sun, Han Dong; Wu, Tom

    2011-08-01

    Controllably constructing hierarchical nanostructures with distinct components and designed architectures is an important theme of research in nanoscience, entailing novel but reliable approaches of bottom-up synthesis. Here, we report a facile method to reproducibly create semiconductor-insulator-metal core/shell nanostructures, which involves first coating uniform MgO shells onto metal oxide nanostructures in solution and then decorating them with Au nanoparticles. The semiconductor nanowire core can be almost any material and, herein, ZnO, SnO2 and In2O3 are used as examples. We also show that linear chains of short ZnO nanorods embedded in MgO nanotubes and porous MgO nanotubes can be obtained by taking advantage of the reduced thermal stability of the ZnO core. Furthermore, after MgO shell-coating and the appropriate annealing treatment, the intensity of the ZnO near-band-edge UV emission becomes much stronger, showing a 25-fold enhancement. The intensity ratio of the UV/visible emission can be increased further by decorating the surface of the ZnO/MgO nanowires with high-density plasmonic Au nanoparticles. These heterostructured semiconductor-insulator-metal nanowires with tailored morphologies and enhanced functionalities have great potential for use as nanoscale building blocks in photonic and electronic applications.Controllably constructing hierarchical nanostructures with distinct components and designed architectures is an important theme of research in nanoscience, entailing novel but reliable approaches of bottom-up synthesis. Here, we report a facile method to reproducibly create semiconductor-insulator-metal core/shell nanostructures, which involves first coating uniform MgO shells onto metal oxide nanostructures in solution and then decorating them with Au nanoparticles. The semiconductor nanowire core can be almost any material and, herein, ZnO, SnO2 and In2O3 are used as examples. We also show that linear chains of short ZnO nanorods embedded in MgO nanotubes and porous MgO nanotubes can be obtained by taking advantage of the reduced thermal stability of the ZnO core. Furthermore, after MgO shell-coating and the appropriate annealing treatment, the intensity of the ZnO near-band-edge UV emission becomes much stronger, showing a 25-fold enhancement. The intensity ratio of the UV/visible emission can be increased further by decorating the surface of the ZnO/MgO nanowires with high-density plasmonic Au nanoparticles. These heterostructured semiconductor-insulator-metal nanowires with tailored morphologies and enhanced functionalities have great potential for use as nanoscale building blocks in photonic and electronic applications. Electronic supplementary information (ESI) available: Representative SEM and TEM images of 700 °C annealed ZnO/MgO core/shell NWs, a TEM image of an individual MgO nanocrystal inside the MgO NTs and SEM images of SnO2 NP chains embedded in MgO NTs and comb-shaped MgO hollow nanostructures. See DOI: 10.1039/c1nr10352k

  15. Fetal programming of body dimensions and percentage body fat measured in prepubertal children with a 4-component model of body composition, dual-energy X-ray absorptiometry, deuterium dilution, densitometry, and skinfold thicknesses.

    PubMed

    Elia, Marinos; Betts, Peter; Jackson, Diane M; Mulligan, Jean

    2007-09-01

    Intrauterine programming of body composition [percentage body fat (%BF)] has been sparsely examined with multiple independent reference techniques in children. The effects on and consequences of body build (dimensions, mass, and length of body segments) are unclear. The study examined whether percentage fat and relation of percentage fat to body mass index (BMI; in kg/m2) in prepubertal children are programmed during intrauterine development and are dependent on body build. It also aimed to examine the extent to which height can be predicted by parental height and birth weight. Eighty-five white children (44 boys, 41 girls; aged 6.5-9.1 y) had body composition measured with a 4-component model (n = 58), dual-energy X-ray absorptiometry (n = 84), deuterium dilution (n = 81), densitometry (n = 62), and skinfold thicknesses (n = 85). An increase in birth weight of 1 SD was associated with a decrease of 1.95% fat as measured by the 4-component model (P = 0.012) and 0.82-2.75% by the other techniques. These associations were independent of age, sex, socioeconomic status, physical activity, BMI, and body build. Body build did not decrease the strength of the associations. Birth weight was a significantly better predictor of height than was self-reported midparental height, accounting for 19.4% of the variability at 5 y of age and 10.3% at 7.8 y of age (17.8% and 8.8% of which were independent of parental height at these ages, respectively). Consistent trends across body-composition measurement techniques add strength to the suggestion that percentage fat in prepubertal children is programmed in utero (independently of body build and BMI). It also suggests birth weight is a better predictor of prepubertal height than is self-reported midparental height.

  16. Monodisperse Metal-Organic Framework Nanospheres with Encapsulated Core-Shell Nanoparticles Pt/Au@Pd@{Co2(oba)4(3-bpdh)2}4H2O for the Highly Selective Conversion of CO2 to CO.

    PubMed

    Zhao, Xi; Xu, Haitao; Wang, XiaoXiao; Zheng, Zhizhong; Xu, Zhenliang; Ge, Jianping

    2018-05-02

    A new microporous metal-organic framework (MOF) with formula {Co 2 (oba) 4 (3-bpdh) 2 }4H 2 O [oba = 4,4'-oxybis(benzoic acid); 3-bpdh = N, N'-bis-(1-pyridine-3-yl-ethylidene)-hydrazine] was assembled, and its morphology was found to undergo a microrod-to-nanosphere transformation with temperature variation. Core-shell Au@Pd functional nanoparticles (NPs) were successfully encapsulated in the center of the monodisperse nanospheres, and Pt NPs were well-dispersed and fully immobilized on the surface of Au@Pd@1Co to build the Pt/Au@Pd@1Co composites, which exhibited NPs catalytic activity for the reverse water gas shift reaction. The core-shell Au@Pd NPs in MOF significantly enchanced the CO selectivity of the catalyst, and the Pt NP loading on the surface of the nanosphere afforded a desirable CO 2 conversion.

  17. Off-shell supergravity in five dimensions and supersymmetric brane world scenarios

    NASA Astrophysics Data System (ADS)

    Zucker, M.

    2003-09-01

    We review the construction of off-shell Poincaré supergravity in five dimensions. We describe in detail the minimal multiplet, which is the basic building block, containing the propagating fields of supergravity. All matter multiplets containing (8 + 8) components, being the smallest matter multiplets in five dimensions, are constructed. Using these multiplets the complete tensor calculus for supergravity is developed. As expected it turns out, that there exist three distinct minimal (i.e. containing (48 + 48) field components) off-shell supergravities. The lagrangians for these theories and their gauged variants are given explicitly. These results are used in the second part to develop a tensor calculus on the orbifold . Gauged supergravity on the orbifold with additional cosmological constants at the fixpoints, is constructed. This generalizes the work of Randall-Sundrum to local supersymmetry. The developed tensor calculus is used to extend this model to include matter located at the fixpoints. Chiral and super Yang-Mills multiplets at the fixpoints are considered.

  18. Geometric Nonlinear Computation of Thin Rods and Shells

    NASA Astrophysics Data System (ADS)

    Grinspun, Eitan

    2011-03-01

    We develop simple, fast numerical codes for the dynamics of thin elastic rods and shells, by exploiting the connection between physics, geometry, and computation. By building a discrete mechanical picture from the ground up, mimicking the axioms, structures, and symmetries of the smooth setting, we produce numerical codes that not only are consistent in a classical sense, but also reproduce qualitative, characteristic behavior of a physical system----such as exact preservation of conservation laws----even for very coarse discretizations. As two recent examples, we present discrete computational models of elastic rods and shells, with straightforward extensions to the viscous setting. Even at coarse discretizations, the resulting simulations capture characteristic geometric instabilities. The numerical codes we describe are used in experimental mechanics, cinema, and consumer software products. This is joint work with Miklós Bergou, Basile Audoly, Max Wardetzky, and Etienne Vouga. This research is supported in part by the Sloan Foundation, the NSF, Adobe, Autodesk, Intel, the Walt Disney Company, and Weta Digital.

  19. Embedded random matrix ensembles from nuclear structure and their recent applications

    NASA Astrophysics Data System (ADS)

    Kota, V. K. B.; Chavda, N. D.

    Embedded random matrix ensembles generated by random interactions (of low body rank and usually two-body) in the presence of a one-body mean field, introduced in nuclear structure physics, are now established to be indispensable in describing statistical properties of a large number of isolated finite quantum many-particle systems. Lie algebra symmetries of the interactions, as identified from nuclear shell model and the interacting boson model, led to the introduction of a variety of embedded ensembles (EEs). These ensembles with a mean field and chaos generating two-body interaction generate in three different stages, delocalization of wave functions in the Fock space of the mean-field basis states. The last stage corresponds to what one may call thermalization and complex nuclei, as seen from many shell model calculations, lie in this region. Besides briefly describing them, their recent applications to nuclear structure are presented and they are (i) nuclear level densities with interactions; (ii) orbit occupancies; (iii) neutrinoless double beta decay nuclear transition matrix elements as transition strengths. In addition, their applications are also presented briefly that go beyond nuclear structure and they are (i) fidelity, decoherence, entanglement and thermalization in isolated finite quantum systems with interactions; (ii) quantum transport in disordered networks connected by many-body interactions with centrosymmetry; (iii) semicircle to Gaussian transition in eigenvalue densities with k-body random interactions and its relation to the Sachdev-Ye-Kitaev (SYK) model for majorana fermions.

  20. A systematic review of animal predation creating pierced shells: implications for the archaeological record of the Old World

    PubMed Central

    Rosin, Zuzanna M.; Tryjanowski, Piotr

    2017-01-01

    Background The shells of molluscs survive well in many sedimentary contexts and yield information about the diet of prehistoric humans. They also yield evidence of symbolic behaviours through their use as beads for body adornments. Researchers often analyse the location of perforations in shells to make judgements about their use as symbolic objects (e.g., beads), the assumption being that holes attributable to deliberate human behaviour are more likely to exhibit low variability in their anatomical locations, while holes attributable to natural processes yield more random perforations. However, there are non-anthropogenic factors that can cause perforations in shells and these may not be random. The aim of the study is compare the variation in holes in shells from archaeological sites from the Old World with the variation of holes in shells pierced by mollusc predators. Methods Three hundred and sixteen scientific papers were retrieved from online databases by using keywords, (e.g., ‘shell beads’; ‘pierced shells’; ‘drilling predators’); 79 of these publications enabled us to conduct a systematic review to qualitatively assess the location of the holes in the shells described in the published articles. In turn, 54 publications were used to assess the location of the holes in the shells made by non-human predators. Results Almost all archaeological sites described shells with holes in a variety of anatomical locations. High variation of hole-placement was found within the same species from the same site, as well as among sites. These results contrast with research on predatory molluscs, which tend to be more specific in where they attacked their prey. Gastropod and bivalve predators choose similar hole locations to humans. Discussion Based on figures in the analysed articles, variation in hole-location on pierced shells from archaeological sites was similar to variation in the placement of holes created by non-human animals. Importantly, we found that some predators choose similar hole locations to humans. We discuss these findings and identify factors researchers might want to consider when interpreting shells recovered from archaeological contexts. PMID:28123913

  1. Analysis of magnetite crystals and inclusion bodies inside magnetotactic bacteria from different environmental locations

    NASA Astrophysics Data System (ADS)

    Oestreicher, Z.; Lower, B.; Lower, S.; Bazylinski, D. A.

    2011-12-01

    Biomineralization occurs throughout the living world; a few common examples include iron oxide in chiton teeth, calcium carbonate in mollusk shells, calcium phosphate in animal bones and teeth, silica in diatom shells, and magnetite crystals inside the cells of magnetotactic bacteria. Biologically controlled mineralization is characterized by biominerals that have species-specific properties such as: preferential crystallographic orientation, consistent particle size, highly ordered spatial locations, and well-defined composition and structure. It is well known that magnetotactic bacteria synthesize crystals of magnetite inside of their cells, but how they mineralize the magnetite is poorly understood. Magnetosomes have a species-specific morphology that is due to specific proteins involved in the mineralization process. In addition to magnetite crystals, magnetotactic bacteria also produce inclusion bodies or granules that contain different elements, such as phosphorus, calcium, and sulfur. In this study we used the transmission electron microscope to analyze the structure of magnetite crystals and inclusion bodies from different species of magnetotactic bacteria in order to determine the composition of the inclusion bodies and to ascertain whether or not the magnetite crystals contain elements other than iron and oxygen. Using energy dispersive spectroscopy we found that different bacteria from different environments possess inclusion bodies that contain different elements such as phosphorus, calcium, barium, magnesium, and sulfur. These differences may reflect the conditions of the environment in which the bacteria inhabit.

  2. Non-invasive imaging methods applied to neo- and paleo-ontological cephalopod research

    NASA Astrophysics Data System (ADS)

    Hoffmann, R.; Schultz, J. A.; Schellhorn, R.; Rybacki, E.; Keupp, H.; Gerden, S. R.; Lemanis, R.; Zachow, S.

    2014-05-01

    Several non-invasive methods are common practice in natural sciences today. Here we present how they can be applied and contribute to current topics in cephalopod (paleo-) biology. Different methods will be compared in terms of time necessary to acquire the data, amount of data, accuracy/resolution, minimum/maximum size of objects that can be studied, the degree of post-processing needed and availability. The main application of the methods is seen in morphometry and volumetry of cephalopod shells. In particular we present a method for precise buoyancy calculation. Therefore, cephalopod shells were scanned together with different reference bodies, an approach developed in medical sciences. It is necessary to know the volume of the reference bodies, which should have similar absorption properties like the object of interest. Exact volumes can be obtained from surface scanning. Depending on the dimensions of the study object different computed tomography techniques were applied.

  3. Applications of Shell-Model Techniques to N = 50 Nuclei.

    NASA Astrophysics Data System (ADS)

    Ji, Xiangdong

    Traditional shell-model techniques, which involve setting up and diagonalizing model Hamiltonians in a finite Hilbert space, have been used to treat the N = 50 isotones. A model space with active f_{5over 2}, p_{3over 2}, p_{1over 2} and g_{9over 2} proton orbits is used to simulate the low-lying excitations of these isotones. An effective Hamiltonian which consists of one-body and two-body interactions is obtained by varying a total of 69 parameters to fit over 140 experimental energy levels in nuclei ranging from ^{82 }Ge to ^{96}Pd. The structures of the model wavefunctions calculated with the empirical model Hamiltonian are analyzed and compared with experimental measurements. It is found that the overall level systematics of N = 50 nuclei are well described by the model treatment. In particular, for the nuclei heavier than ^{88}Sr, the present results are not essentially different from those obtained in the p_{1over 2}-g_ {9over 2} model space, and for those lighter than ^{88}Sr, the wavefunctions are dominated by f_{5 over 2}-p_{3over 2}-p _{1over2} configurations. The model predictions for very proton-deficient, very unstable nuclei are presented for further experimental verification. Spectroscopic factors for single-proton-transfer reactions and M1 and E2 transition rates and moments are calculated using these model wavefunctions. Effective strengths of electromagnetic operators are adjusted in order to achieve the best agreement between the model predictions and experimental data. The effective proton charge is determined to be 1.9 e. The spin g-factor is found to be quenched by 16 percent for the fp shell orbits and by 29 percent for the g_{9over 2 } orbit. A new shell-model code which is capable of performing shell-model calculations in a general LS -coupling basis has been constructed. The code can be implemented with shell-model truncation schemes for both the LS -coupling limit and the seniority limit. Examples from the Ni isotopes are used to illustrate applications of the code.

  4. Acharan sulfate, the new glycosaminoglycan from Achatina fulica Bowdich 1822. Structural heterogeneity, metabolic labeling and localization in the body, mucus and the organic shell matrix.

    PubMed

    Vieira, Tuane C R G; Costa-Filho, Adilson; Salgado, Norma C; Allodi, Silvana; Valente, Ana-Paula; Nasciutti, Luiz E; Silva, Luiz-Claudio F

    2004-02-01

    Acharan sulfate, a recently discovered glycosaminoglycan isolated from Achatina fulica, has a major disaccharide repeating unit of -->4)-2-acetyl,2-deoxy-alpha-d-glucopyranose(1-->4)-2-sulfo-alpha-l-idopyranosyluronic acid (1-->, making it structurally related to both heparin and heparan sulfate. It has been suggested that this glycosaminoglycan is polydisperse, with an average molecular mass of 29 kDa and known minor disaccharide sequence variants containing unsulfated iduronic acid. Acharan sulfate was found to be located in the body of this species using alcian blue staining and it was suggested to be the main constituent of the mucus. In the present work, we provide further information on the structure and compartmental distribution of acharan sulfate in the snail body. Different populations of acharan sulfate presenting charge and/or molecular mass heterogeneities were isolated from the whole body, as well as from mucus and from the organic shell matrix. A minor glycosaminoglycan fraction susceptible to degradation by nitrous acid was also purified from the snail body, suggesting the presence of N-sulfated glycosaminoglycan molecules. In addition, we demonstrate the in vivo metabolic labeling of acharan sulfate in the snail body after a meal supplemented with [35S]free sulfate. This simple approach might be applied to the study of acharan sulfate biosynthesis. Finally, we developed histochemical assays to localize acharan sulfate in the snail body by metachromatic staining and by histoautoradiography following metabolic radiolabeling with [35S]sulfate. Our results show that acharan sulfate is widely distributed among several organs.

  5. Multifunctional Core–Shell Nanoparticles: Discovery of Previously Invisible Biomarkers

    PubMed Central

    2011-01-01

    Many low-abundance biomarkers for early detection of cancer and other diseases are invisible to mass spectrometry because they exist in body fluids in very low concentrations, are masked by high-abundance proteins such as albumin and immunoglobulins, and are very labile. To overcome these barriers, we created porous, buoyant, core–shell hydrogel nanoparticles containing novel high affinity reactive chemical baits for protein and peptide harvesting, concentration, and preservation in body fluids. Poly(N-isopropylacrylamide-co-acrylic acid) nanoparticles were functionalized with amino-containing dyes via zero-length cross-linking amidation reactions. Nanoparticles functionalized in the core with 17 different (12 chemically novel) molecular baits showed preferential high affinities (KD < 10–11 M) for specific low-abundance protein analytes. A poly(N-isopropylacrylamide-co-vinylsulfonic acid) shell was added to the core particles. This shell chemistry selectively prevented unwanted entry of all size peptides derived from albumin without hindering the penetration of non-albumin small proteins and peptides. Proteins and peptides entered the core to be captured with high affinity by baits immobilized in the core. Nanoparticles effectively protected interleukin-6 from enzymatic degradation in sweat and increased the effective detection sensitivity of human growth hormone in human urine using multiple reaction monitoring analysis. Used in whole blood as a one-step, in-solution preprocessing step, the nanoparticles greatly enriched the concentration of low-molecular weight proteins and peptides while excluding albumin and other proteins above 30 kDa; this achieved a 10,000-fold effective amplification of the analyte concentration, enabling mass spectrometry (MS) discovery of candidate biomarkers that were previously undetectable. PMID:21999289

  6. Radially Symmetric Motions of Nonlinearly Viscoelastic Bodies Under Live Loads

    NASA Astrophysics Data System (ADS)

    Stepanov, Alexey B.; Antman, Stuart S.

    2017-12-01

    This paper treats radially symmetric motions of nonlinearly viscoelastic circular-cylindrical and spherical shells subjected to the live loads of centrifugal force and (time-dependent) hydrostatic pressures. The governing equations are exact versions of those for 3-dimensional continuum mechanics (so shell does not connote an approximate via some shell theory). These motions are governed by quasilinear third-order parabolic-hyperbolic equations having but one independent spatial variable. The principal part of such a partial differential equation is determined by a general family of nonlinear constitutive equations. The presence of strains in two orthogonal directions requires a careful treatment of constitutive restrictions that are physically natural and support the analysis. The interaction of geometrically exact formulations, the compatible use of general constitutive equations for material response, and the presence of live loads show how these factors play crucial roles in the behavior of solutions. In particular, for different kinds of live loads there are thresholds separating materials that produce qualitatively different dynamical behavior. The analysis (using classical methods) covers infinite-time blowup for cylindrical shells subject to centrifugal forces, infinite-time blowup for cylindrical shells subject to steady and time-dependent hydrostatic pressures, finite-time blowup for spherical shells subject to steady and time-dependent hydrostatic pressures, and the preclusion of total compression. This paper concludes with a sketch (using some modern methods) of the existence of regular solutions until the time of blowup.

  7. Fishing and bottom water temperature as drivers of change in maximum shell length in Atlantic surfclams (Spisula solidissima)

    NASA Astrophysics Data System (ADS)

    Munroe, D. M.; Narváez, D. A.; Hennen, D.; Jacobson, L.; Mann, R.; Hofmann, E. E.; Powell, E. N.; Klinck, J. M.

    2016-03-01

    Maximum shell length of Atlantic surfclams (Spisula solidissima) on the Middle Atlantic Bight (MAB) continental shelf, obtained from federal fishery survey data from 1982-present, has decreased by 15-20 mm. Two potential causes of this decreasing trend, fishery removal of large animals and stress due to warming bottom temperatures, were investigated using an individual-based model for post-settlement surfclams and a fifty-year hindcast of bottom water temperatures on the MAB. Simulations showed that fishing and/or warming bottom water temperature can cause decreases in maximum surfclam shell length (body size) equivalent to those observed in the fished stock. Independently, either localized fishing rates of 20% or sustained bottom temperatures that are 2 °C warmer than average conditions generate the observed decrease in maximum shell length. However, these independent conditions represent extremes and are not sustained in the MAB. The combined effects of fishing and warmer temperatures can generate simulated length decreases that are similar to observed decreases. Interannual variability in bottom water temperatures can also generate fluctuations in simulated shell length of up to 20 mm over a period of 10-15 years. If the change in maximum size is not genotypic, simulations also suggest that shell size composition of surfclam populations can recover if conditions change; however, that recovery could take a decade to become evident.

  8. Solar radiation stress in climbing snails: behavioural and intrinsic features define the Hsp70 level in natural populations of Xeropicta derbentina (Pulmonata).

    PubMed

    Di Lellis, Maddalena A; Seifan, Merav; Troschinski, Sandra; Mazzia, Christophe; Capowiez, Yvan; Triebskorn, Rita; Köhler, Heinz-R

    2012-11-01

    Ectotherms from sunny and hot environments need to cope with solar radiation. Mediterranean land snails of the superfamily Helicoidea feature a behavioural strategy to escape from solar radiation-induced excessive soil heating by climbing up vertical objects. The height of climbing, and also other parameters like shell colouration pattern, shell orientation, shell size, body mass, actual internal and shell surface temperature, and the interactions between those factors may be expected to modulate proteotoxic effects in snails exposed to solar radiation and, thus, their stress response. Focussing on natural populations of Xeropicta derbentina, we conducted a 'snapshot' field study using the individual Hsp70 level as a proxy for proteotoxic stress. In addition to correlation analyses, an IT-model selection approach based on Akaike's Information Criterion was applied to evaluate a set of models with respect to their explanatory power and to assess the relevance of each of the above-mentioned parameters for individual stress, by model averaging and parameter estimation. The analysis revealed particular importance of the individuals' shell size, height above ground, the shell colouration pattern and the interaction height × orientation. Our study showed that a distinct set of behavioural traits and intrinsic characters define the Hsp70 level and that environmental factors and individual features strongly interact.

  9. Hollow Pollen Shells to Enhance Drug Delivery

    PubMed Central

    Diego-Taboada, Alberto; Beckett, Stephen T.; Atkin, Stephen L.; Mackenzie, Grahame

    2014-01-01

    Pollen grain and spore shells are natural microcapsules designed to protect the genetic material of the plant from external damage. The shell is made up of two layers, the inner layer (intine), made largely of cellulose, and the outer layer (exine), composed mainly of sporopollenin. The relative proportion of each varies according to the plant species. The structure of sporopollenin has not been fully characterised but different studies suggest the presence of conjugated phenols, which provide antioxidant properties to the microcapsule and UV (ultraviolet) protection to the material inside it. These microcapsule shells have many advantageous properties, such as homogeneity in size, resilience to both alkalis and acids, and the ability to withstand temperatures up to 250 °C. These hollow microcapsules have the ability to encapsulate and release actives in a controlled manner. Their mucoadhesion to intestinal tissues may contribute to the extended contact of the sporopollenin with the intestinal mucosa leading to an increased efficiency of delivery of nutraceuticals and drugs. The hollow microcapsules can be filled with a solution of the active or active in a liquid form by simply mixing both together, and in some cases operating a vacuum. The active payload can be released in the human body depending on pressure on the microcapsule, solubility and/or pH factors. Active release can be controlled by adding a coating on the shell, or co-encapsulation with the active inside the shell. PMID:24638098

  10. In-medium similarity renormalization group for closed and open-shell nuclei

    NASA Astrophysics Data System (ADS)

    Hergert, H.

    2017-02-01

    We present a pedagogical introduction to the in-medium similarity renormalization group (IMSRG) framework for ab initio calculations of nuclei. The IMSRG performs continuous unitary transformations of the nuclear many-body Hamiltonian in second-quantized form, which can be implemented with polynomial computational effort. Through suitably chosen generators, it is possible to extract eigenvalues of the Hamiltonian in a given nucleus, or drive the Hamiltonian matrix in configuration space to specific structures, e.g., band- or block-diagonal form. Exploiting this flexibility, we describe two complementary approaches for the description of closed- and open-shell nuclei: the first is the multireference IMSRG (MR-IMSRG), which is designed for the efficient calculation of nuclear ground-state properties. The second is the derivation of non-empirical valence-space interactions that can be used as input for nuclear shell model (i.e., configuration interaction (CI)) calculations. This IMSRG+shell model approach provides immediate access to excitation spectra, transitions, etc, but is limited in applicability by the factorial cost of the CI calculations. We review applications of the MR-IMSRG and IMSRG+shell model approaches to the calculation of ground-state properties for the oxygen, calcium, and nickel isotopic chains or the spectroscopy of nuclei in the lower sd shell, respectively, and present selected new results, e.g., for the ground- and excited state properties of neon isotopes.

  11. 13. BUILDING NO. 621, INTERIOR, TOP OF BLASTING TUB UNDERNEATH ...

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

    13. BUILDING NO. 621, INTERIOR, TOP OF BLASTING TUB UNDERNEATH SAWDUST HOPPER. BLASTING TUB HAS DOUBLE WALLS OF 3/4' THICK STEEL ARMOR PLATE. CHARGE TO BE TESTED IS BURIED IN SAWDUST WITH FLAME RESISTANT CHEMICALS. ELEVATOR BEHIND TUB CARRIES SAWDUST BACK TO TOP OF SAWDUST HOPPER AFTER TEST IS COMPLETED AND SAWDUST IN BLASTING TUB HAS BEEN SIFTED FOR SHELL FRAGMENTS. LOUVERS IN WALLS ARE HINGED FREELY SO THEY OPEN TO RELIEVE BLAST PRESSURE DURING A TEST. - Picatinny Arsenal, 600 Area, Test Areas District, State Route 15 near I-80, Dover, Morris County, NJ

  12. On the Half Shell: An Introduction to Oysters and Their Unique Structures and Function

    ERIC Educational Resources Information Center

    Frederick, J. Adam; Haines, Sarah; Romano, Christina; Takacs, Jacqueline

    2017-01-01

    The eastern oyster, "Crassostrea virginica," is an ecologically and economically important species in Chesapeake Bay. Oysters are ecologically unique in the Chesapeake Bay because they build a structure known as a bar or reef by attaching to one another over a 45 long period of time. They have been coined the "Ecological Engineers…

  13. 7 CFR 56.76 - Minimum facility and operating requirements for shell egg grading and packing plants.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... or rodents. (3) Buildings shall be of sound construction so as to prevent, insofar as practicable... cleaned at the end of each operating day. (5) The floors, walls, ceilings, partitions, and other parts of... reflection of light that interfere with, or prohibit the accurate quality determination of eggs in the...

  14. 7 CFR 56.76 - Minimum facility and operating requirements for shell egg grading and packing plants.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... or rodents. (3) Buildings shall be of sound construction so as to prevent, insofar as practicable... cleaned at the end of each operating day. (5) The floors, walls, ceilings, partitions, and other parts of... reflection of light that interfere with, or prohibit the accurate quality determination of eggs in the...

  15. 7 CFR 56.76 - Minimum facility and operating requirements for shell egg grading and packing plants.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... or rodents. (3) Buildings shall be of sound construction so as to prevent, insofar as practicable... cleaned at the end of each operating day. (5) The floors, walls, ceilings, partitions, and other parts of... reflection of light that interfere with, or prohibit the accurate quality determination of eggs in the...

  16. 7 CFR 56.76 - Minimum facility and operating requirements for shell egg grading and packing plants.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... or rodents. (3) Buildings shall be of sound construction so as to prevent, insofar as practicable... cleaned at the end of each operating day. (5) The floors, walls, ceilings, partitions, and other parts of... reflection of light that interfere with, or prohibit the accurate quality determination of eggs in the...

  17. 7 CFR 56.76 - Minimum facility and operating requirements for shell egg grading and packing plants.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... or rodents. (3) Buildings shall be of sound construction so as to prevent, insofar as practicable... cleaned at the end of each operating day. (5) The floors, walls, ceilings, partitions, and other parts of... reflection of light that interfere with, or prohibit the accurate quality determination of eggs in the...

  18. 50 CFR 32.24 - California.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... accompany one adult hunter. 2. You may only possess approved nontoxic shot while in the field (see § 32.2(k... nontoxic shot while in the field (see § 32.2(k)). 2. Each hunter may not possess more than 25 shells while... field. 6. You may possess only approved nontoxic shot while in the field. 7. No person may build or...

  19. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Reidel, Stephen P.

    This chapter summarizes the geology of the single-shell tank (SST) farms in the context of the region’s geologic history. This chapter is based on the information in the geology data package for the SST waste management areas and SST RFI Appendix E, which builds upon previous reports on the tank farm geology and Integrated Disposal Facility geology with information available after those reports were published.

  20. Swimming of a Tiny Subtropical Sea Butterfly with Coiled Shell

    NASA Astrophysics Data System (ADS)

    Murphy, David; Karakas, Ferhat; Maas, Amy

    2017-11-01

    Sea butterflies, also known as pteropods, include a variety of small, zooplanktonic marine snails. Thecosomatous pteropods possess a shell and swim at low Reynolds numbers by beating their wing-like parapodia in a manner reminiscent of insect flight. In fact, previous studies of the pteropod Limacina helicina have shown that pteropod swimming hydrodynamics and tiny insect flight aerodynamics are dynamically similar. Studies of L. helicina swimming have been performed in polar (0 degrees C) and temperate conditions (12 degrees C). Here we present measurements of the swimming of Heliconoides inflatus, a smaller yet morphologically similar pteropod that lives in warm Bermuda seawater (21 degrees C) with a viscosity almost half that of the polar seawater. The collected H. inflatus have shell sizes less than 1.5 mm in diameter, beat their wings at frequencies up to 11 Hz, and swim upwards in sawtooth trajectories at speeds up to approximately 25 mm/s. Using three-dimensional wing and body kinematics collected with two orthogonal high speed cameras and time-resolved, 2D flow measurements collected with a micro-PIV system, we compare the effects of smaller body size and lower water viscosity on the flow physics underlying flapping-based swimming by pteropods and flight by tiny insects.

  1. Wooden shell of M2-F1 being assembled at El Mirage

    NASA Technical Reports Server (NTRS)

    1962-01-01

    Wooden shell of the M2-F1 being assembled at El Mirage, CA. While Flight Research Center technicians built the internal steel structure of the M2-F1, sailplane builder Gus Briegleb built the vehicle's outer wooden shell. Its skin was 3/32-inch mahogany plywood, with 1/8-inch mahogany rib sections reinforced with spruce. The wingless, lifting body aircraft design was initially conceived as a means of landing an aircraft horizontally after atmospheric reentry. The absence of wings would make the extreme heat of re-entry less damaging to the vehicle. In 1962, Dryden management approved a program to build a lightweight, unpowered lifting body as a prototype to flight test the wingless concept. It would look like a 'flying bathtub,' and was designated the M2-F1, the 'M' referring to 'manned' and 'F' referring to 'flight' version. It featured a plywood shell placed over a tubular steel frame crafted at Dryden. Construction was completed in 1963. The first flight tests of the M2-F1 were over Rogers Dry Lake at the end of a tow rope attached to a hopped-up Pontiac convertible driven at speeds up to about 120 mph. This vehicle needed to be able to tow the M2-F1 on the Rogers Dry Lakebed adjacent to NASA's Flight Research Center (FRC) at a minimum speed of 100 miles per hour. To do that, it had to handle the 400-pound pull of the M2-F1. Walter 'Whitey' Whiteside, who was a retired Air Force maintenance officer working in the FRC's Flight Operations Division, was a dirt-bike rider and hot-rodder. Together with Boyden 'Bud' Bearce in the Procurement and Supply Branch of the FRC, Whitey acquired a Pontiac Catalina convertible with the largest engine available. He took the car to Bill Straup's renowned hot-rod shop near Long Beach for modification. With a special gearbox and racing slicks, the Pontiac could tow the 1,000-pound M2-F1 110 miles per hour in 30 seconds. It proved adequate for the roughly 400 car tows that got the M2-F1 airborne to prove it could fly safely and to train pilots before they were towed behind a C-47 aircraft and released. These initial car-tow tests produced enough flight data about the M2-F1 to proceed with flights behind the C-47 tow plane at greater altitudes. The C-47 took the craft to an altitude of 12,000 where free flights back to Rogers Dry Lake began. Pilot for the first series of flights of the M2-F1 was NASA research pilot Milt Thompson. Typical glide flights with the M2-F1 lasted about two minutes and reached speeds of 110 to l20 mph. A small solid landing rocket, referred to as the 'instant L/D rocket,' was installed in the rear base of the M2-F1. This rocket, which could be ignited by the pilot, provided about 250 pounds of thrust for about 10 seconds. The rocket could be used to extend the flight time near landing if needed. More than 400 ground tows and 77 aircraft tow flights were carried out with the M2-F1. The success of Dryden's M2-F1 program led to NASA's development and construction of two heavyweight lifting bodies based on studies at NASA's Ames and Langley research centers--the M2-F2 and the HL-10, both built by the Northrop Corporation, and the U.S. Air Force's X-24 program, with an X-24A and -B built by Martin. The Lifting Body program also heavily influenced the Space Shuttle program. The M2-F1 program demonstrated the feasibility of the lifting body concept for horizontal landings of atmospheric entry vehicles. It also demonstrated a procurement and management concept for prototype flight test vehicles that produced rapid results at very low cost (approximately $50,000, excluding salaries of government employees assigned to the project).

  2. Planetary Ice-Oceans: Numerical Modeling Study of Ice-Shell Growth in Convecting Two-Phase Systems

    NASA Astrophysics Data System (ADS)

    Allu Peddinti, Divya; McNamara, Allen

    2017-04-01

    Several icy bodies in the Solar system such as the icy moons Europa and Enceladus exhibit signs of subsurface oceans underneath an ice-shell. For Europa, the geologically young surface, the presence of surface features and the aligned surface chemistry pose interesting questions about formation of the ice-shell and its interaction with the ocean below. This also ties in with its astrobiological potential and implications for similar ice-ocean systems elsewhere in the cosmos. The overall thickness of the H2O layer on Europa is estimated to be 100-150 km while the thickness of the ice-shell is debated. Additionally, Europa is subject to tidal heating due to interaction with Jupiter's immense gravity field. It is of interest to understand how the ice-shell thickness varies in the presence of tidal internal heating and the localization of heating in different regions of the ice-shell. Thus this study aims to determine the effect of tidal internal heating on the growth rate of the ice-shell over time. We perform geodynamic modeling of the ice-ocean system in order to understand how the ice-shell thickness changes with time. The convection code employs the ice Ih-water phase diagram in order to model the two-phase convecting ice-ocean system. All the models begin from an initial warm thick ocean that cools from the top. The numerical experiments analyze three cases: case 1 with no tidal internal heating in the system, case 2 with constant tidal internal heating in the ice and case 3 with viscosity-dependent tidal internal heating in the ice. We track the ice-shell thickness as a function of time as the system cools. Modeling results so far have identified that the shell growth rate changes substantially at a point in time that coincides with a change in the planform of ice-convection cells. Additionally, the velocity vs depth plots indicate a shift from a conduction dominant to a convection dominant ice regime. We compare the three different cases to provide a comprehensive understanding of the temporal variation in the ice-shell thickness due to the addition of heating in the ice.

  3. On the control of a robot ball using two omniwheels

    NASA Astrophysics Data System (ADS)

    Ivanov, Alexander P.

    2015-07-01

    We discuss the dynamics of a balanced body of spherical shape on a rough plane, controlled by the movement of a built-in shell. These two shells are set in relative motion due to rotation of the two symmetrical omniwheels. It is shown that the ball can be moved to any point on the plane along a straight or (in the case of the initial degeneration) polygonal line. Moreover, any prescribed curvilinear trajectory of the ball center can be followed by an appropriate control strategy as far as the diameter connecting both wheels is nonvertical.

  4. 49 CFR 661.11 - Rolling stock procurements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Devices; (21) Car Axle Counters; (22) Communication Based Train Control (CBTC). (u) Communication... components of a bus. This list is not all-inclusive. Car body shells, egines, transmissions, front axle... assemblies, air compressor and pneumatic systems, generator/alternator and electrical systems, steering...

  5. 49 CFR 661.11 - Rolling stock procurements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Devices; (21) Car Axle Counters; (22) Communication Based Train Control (CBTC). (u) Communication... components of a bus. This list is not all-inclusive. Car body shells, egines, transmissions, front axle... assemblies, air compressor and pneumatic systems, generator/alternator and electrical systems, steering...

  6. Voids and superstructures: correlations and induced large-scale velocity flows

    NASA Astrophysics Data System (ADS)

    Lares, Marcelo; Luparello, Heliana E.; Maldonado, Victoria; Ruiz, Andrés N.; Paz, Dante J.; Ceccarelli, Laura; Garcia Lambas, Diego

    2017-09-01

    The expanding complex pattern of filaments, walls and voids build the evolving cosmic web with material flowing from underdense on to high density regions. Here, we explore the dynamical behaviour of voids and galaxies in void shells relative to neighbouring overdense superstructures, using the Millenium simulation and the main galaxy catalogue in Sloan Digital Sky Survey data. We define a correlation measure to estimate the tendency of voids to be located at a given distance from a superstructure. We find voids-in-clouds (S-types) preferentially located closer to superstructures than voids-in-voids (R-types) although we obtain that voids within ˜40 h-1 Mpc of superstructures are infalling in a similar fashion independently of void type. Galaxies residing in void shells show infall towards the closest superstructure, along with the void global motion, with a differential velocity component depending on their relative position in the shell with respect to the direction to the superstructure. This effect is produced by void expansion and therefore is stronger for R-types. We also find that galaxies in void shells facing the superstructure flow towards the overdensities faster than galaxies elsewhere at the same relative distance to the superstructure. The results obtained for the simulation are also reproduced for the Sky Survey Data Release data with a linearized velocity field implementation.

  7. Nanoclusters as a new family of high temperature superconductors (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Halder, Avik; Kresin, Vitaly V.

    2017-03-01

    Electrons in metal clusters organize into quantum shells, akin to atomic shells in the periodic table. Such nanoparticles are referred to as "superatoms". The electronic shell levels are highly degenerate giving rise to sharp peaks in the density of states, which can enable exceptionally strong electron pairing in certain clusters containing tens to hundreds of atoms. A spectroscopic investigation of size - resolved aluminum nanoclusters has revealed a sharp rise in the density of states near the Fermi level as the temperature decreases towards 100 K. The effect is especially prominent in the closed-shell "magic" cluster Al66 [1, 2]. The characteristics of this behavior are fully consistent with a pairing transition, implying a high temperature superconducting state with Tc < 100K. This value exceeds that of bulk aluminum by two orders of magnitude. As a new class of high-temperature superconductors, such metal nanocluster particles are promising building blocks for high-Tc materials, devices, and networks. ---------- 1. Halder, A., Liang, A., Kresin, V. V. A novel feature in aluminum cluster photoionization spectra and possibility of electron pairing at T 100K. Nano Lett 15, 1410 - 1413 (2015) 2. Halder, A., Kresin, V. V. A transition in the density of states of metal "superatom" nanoclusters and evidence for superconducting pairing at T 100K. Phys. Rev. B 92, 214506 (2015).

  8. Monolithic photonic crystals created by partial coalescence of core-shell particles.

    PubMed

    Lee, Joon-Seok; Lim, Che Ho; Yang, Seung-Man; Kim, Shin-Hyun

    2014-03-11

    Colloidal crystals and their derivatives have been intensively studied and developed during the past two decades due to their unique photonic band gap properties. However, complex fabrication procedures and low mechanical stability severely limit their practical uses. Here, we report stable photonic structures created by using colloidal building blocks composed of an inorganic core and an organic shell. The core-shell particles are convectively assembled into an opal structure, which is then subjected to thermal annealing. During the heat treatment, the inorganic cores, which are insensitive to heat, retain their regular arrangement in a face-centered cubic lattice, while the organic shells are partially fused with their neighbors; this forms a monolithic structure with high mechanical stability. The interparticle distance and therefore stop band position are precisely controlled by the annealing time; the distance decreases and the stop band blue shifts during the annealing. The composite films can be further treated to give a high contrast in the refractive index. The inorganic cores are selectively removed from the composite by wet etching, thereby providing an organic film containing regular arrays of air cavities. The high refractive index contrast of the porous structure gives rise to pronounced structural colors and high reflectivity at the stop band position.

  9. Curvature-Induced Instabilities of Shells

    NASA Astrophysics Data System (ADS)

    Pezzulla, Matteo; Stoop, Norbert; Steranka, Mark P.; Bade, Abdikhalaq J.; Holmes, Douglas P.

    2018-01-01

    Induced by proteins within the cell membrane or by differential growth, heating, or swelling, spontaneous curvatures can drastically affect the morphology of thin bodies and induce mechanical instabilities. Yet, the interaction of spontaneous curvature and geometric frustration in curved shells remains poorly understood. Via a combination of precision experiments on elastomeric spherical shells, simulations, and theory, we show how a spontaneous curvature induces a rotational symmetry-breaking buckling as well as a snapping instability reminiscent of the Venus fly trap closure mechanism. The instabilities, and their dependence on geometry, are rationalized by reducing the spontaneous curvature to an effective mechanical load. This formulation reveals a combined pressurelike term in the bulk and a torquelike term in the boundary, allowing scaling predictions for the instabilities that are in excellent agreement with experiments and simulations. Moreover, the effective pressure analogy suggests a curvature-induced subcritical buckling in closed shells. We determine the critical buckling curvature via a linear stability analysis that accounts for the combination of residual membrane and bending stresses. The prominent role of geometry in our findings suggests the applicability of the results over a wide range of scales.

  10. First fossil gravid turtle provides insight into the evolution of reproductive traits in turtles.

    PubMed

    Zelenitsky, Darla K; Therrien, Franc Ois; Joyce, Walter G; Brinkman, Donald B

    2008-12-23

    Here we report on the first discovery of shelled eggs inside the body cavity of a fossil turtle and on an isolated egg clutch, both referable to the Cretaceous turtle Adocus. These discoveries provide a unique opportunity to gain insight into the reproductive traits of an extinct turtle and to understand the evolution of such traits among living turtles. The gravid adult and egg clutch indicate that Adocus laid large clutches of rigid-shelled spherical eggs and established their nests near rivers, traits that are shared by its closest living relatives, the soft-shelled turtles. Adocus eggshell, however, was probably more rigid than that of living turtles, based on its great thickness and structure, features that may represent unique adaptations to intense predation or to arid nest environments. In light of the reproductive traits observed in Adocus, the distribution of reproductive traits among turtles reveals that large clutches of rigid-shelled eggs are primitive for hidden-necked turtles (cryptodirans) and that spherical eggs may have evolved independently within this group.

  11. Prospects For Earth-Based Measurements Of Europa's Librations

    NASA Astrophysics Data System (ADS)

    Margot, Jean-Luc; Campbell, D. B.; Peale, S. J.

    2010-10-01

    The exploration of Europa is of great interest because it may be hospitable to certain life forms [1]. Several lines of evidence suggest that a subsurface ocean exists beneath an icy shell [2,3], but there is debate about the thickness of the shell [4], which impacts Europa's astrobiological potential. As in the case of Mercury, it may be possible to determine whether an outer shell is decoupled from the interior and to evaluate the shell thickness by measuring the amplitude of forced longitude librations [5,6]. In the simplest configuration of a rigid shell decoupled from a spherically symmetric interior, the libration amplitude is amplified from the nominal value of 18" by C/Cs, where C is the polar moment of inertia of the body and Cs is that of the outer shell that participates in the librations. For a 100-km thick shell, the libration amplitude would reach 200", an estimate that remains valid even in the presence of gravitational coupling between asymmetrical layers [7]. If there are significant departures from rigid behavior, the shell may deform with the ocean underneath and exhibit a libration amplitude of 52" [8]. Europa reaches closest approach in October 2011, offering a once-in-a-decade opportunity to measure spin rate variations by tracking radar speckles, as advocated by Holin [9,10]. Librations of a rigid shell thinner than 100 km would be detectable. We will describe the experimental design and expected sensitivity. References: [1] NRC, Europa Science Strategy, 1999. [2,3] Kivelson et al, Greeley et al, in Jupiter, CUP, 2004. [4] Greenberg, Unmasking Europa, Praxis, 2008. [5] Peale, Nature 262, 1976. [6] Margot et al, Science 316, 2007. [7] van Hoolst et al, Icarus 195, 2008. [8] Goldreich and Mitchell, Icarus, in press. [9] Green, in Radar Astronomy, McGraw-Hill, 1968. [10] Holin, Radiophys. Quant. Elec. 31, 1988.

  12. ShopGirls Shine in Eco-Marathon

    ERIC Educational Resources Information Center

    Stowell, Shante

    2011-01-01

    The ShopGirls of Granite Falls (WA) High School are the first-ever all-female team to successfully design, build, and race a prototype diesel car in the Shell Eco-marathon. The team took first place in the diesel fuel-efficiency category with a vehicle that achieved 470 miles per gallon! The idea for the ShopGirls came when Vervia Gabriel, career…

  13. DOE Zero Energy Ready Home Case Study: Alliance Green Builders, Casa Aguila

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pacific Northwest National Laboratory

    Alliance Green Builders built this 3,129-ft2 home in the hills above Ramona, California, to the high-performance criteria of the DOE Zero Energy Ready Home (ZERH) program. The home should perform far better than net zero thanks to a super-efficient building shell, a wind turbine, three suntracking solar photovoltaic arrays, and solar thermal water heating.

  14. Programming your way out of the past: ISIS and the META Project

    NASA Technical Reports Server (NTRS)

    Birman, Kenneth P.; Marzullo, Keith

    1989-01-01

    The ISIS distributed programming system and the META Project are described. The ISIS programming toolkit is an aid to low-level programming that makes it easy to build fault-tolerant distributed applications that exploit replication and concurrent execution. The META Project is reexamining high-level mechanisms such as the filesystem, shell language, and administration tools in distributed systems.

  15. Flowfield Analysis of a Small Entry Probe (SPRITE) Tested in an Arc Jet

    NASA Technical Reports Server (NTRS)

    Prabhu, Dinesh K.

    2012-01-01

    A novel concept of small size (diameter less than 15 inches) entry probes named SPRITE (Small Probe Re-entry Investigation for TPS Engineering) has been developed at NASA Ames Research Center (ARC). These flight probes have on-board data acquisition systems that have also been developed in parallel at NASA ARC by Greg Swanson1. Flight probes of this size facilitate testing over a wide range of conditions in arc jets available at NASA ARC, thereby fulfilling a 'test what you fly' paradigm. As indicated by the acronym, these probes, with suitably tailored trajectories, are primarily meant to be robotic flight test beds for TPS materials, although the design is flexible enough to accommodate additional objectives of flight-testing other vehicle subsystems. A first step towards establishing the feasibility of the SPRITE concept is to arc-jet test fully instrumented models at flight scale. In a follow-on to the Large-Scale Article Tests (LSAT2) performed in the 60 MW Interaction Heating Facility (IHF) in late 2008/early 2009, a full-scale model of Deep Space-2 (DS23) made of red oak was tested in the 20 MW Aerodynamic Heating Facility (AHF). There were no issues with mass capture by the diffuser for blunt bodies of roughly 15 inches diameter tested in the 18-inch nozzle of the AHF. Building on this initial success, two identical test articles - SPRITE-T1-1 and SPRITE-T1-2 (T1 indicating the choice of back shell geometry) - were fabricated, and one of them, SPRITE-T1-1, was tested in the AHF recently. Both these test articles, 14 inches in diameter, have a 45deg sphere-cone (like DS2) made of PICA bonded on to a 1/8th inch thick aluminum shell using RTV. The aft portion of the test article is a conical frustum (15deg cone angle) with LI-2200 bonded on to the aluminum shell. Each model is fully instrumented with: (a) thermocouples imbedded in plugs in the heat shield, (b) thermocouples bonded to the aluminum substructure; the thermocouples are distributed over the entire shell, and (c) a few strain gages. Data from some of the thermocouples and gages are acquired by the on-board data acquisition system (DAS), while data from the others are routed to the facility-provided DAS, thereby enabling a cross check on the in situ measurement capability. as inputs to v2.6.1 of the in-house materials thermal response code, FIAT

  16. Mg isotopes in biocarbonates: new insight into vital effects associated to echinoderms and bivalves calcification

    NASA Astrophysics Data System (ADS)

    Planchon, F.; Hermans, J.; Borremans, C.; Dubois, P.; Poulain, C.; Paulet, Y.; Andre, L.

    2007-12-01

    Mg isotopes can be helpful tracers to reveal the fundamental pathways of Mg incorporation during biomineralisation. We report in this study a detailed characterisation of the Mg isotopic signatures of different biominerals: high magnesium calcitic skeletons of selected echinoderms (sea urchins and starfish) and low magnesium aragonitic shells of a bivalve species (clam). State of the art analytical procedures were applied including sample purification step followed by high precision measurements using MC-ICP-MS (Nu instrument) in dry plasma conditions. 26Mg/24Mg and 25Mg/24Mg are expressed as per mil deviations from the DSM3 (Dead Sea Metal 3) reference standard in delta notation (d26Mg and d25Mg). For echinoderms, we considered: (a) adult specimens of six starfish species (Asteria r., Marthasterias g., Anseropoda p., Asterina g., Echinaster s. and Henricia o.), sampled in Brittany (France); (b) a sea urchin species (Paracentrotus lividus) with field samples (Mediterranean Sea, Marseille, France) and culture specimen under T and S controlled conditions. In vivo endoskeletons display negative, but different d26Mg values of -3.06 for starfish (with uniform interspecies signatures) and -2.65 for sea urchin. Relative to seawater signature (-0.82), all echinoderms favour the incorporation of light isotopes during biocalcification. The d26Mg depletion is lower than theoretically expected from a inorganic calcite precipitation from seawater (at -3.5). These differences suggest that on its route from seawater to the shell, Mg isotopes are partly biologically fractionationated through "vital effects" leaving heavier Mg isotopic signatures. Taken into account that calcification in echinoderms is an intra- cellular process involving transient amorphous calcium carbonate (ACC) phase, the observed bio-fractionation factors can be related to: (1) changes in the isotopic composition of the precipitating intracellular fluids due to active pumping in and out of the cell; (2) a specific control of isotopic exchange by ACC. For bivalves, we considered one clam species (Ruditapes Philippinarum) from two different sampling sites in the gulf of Morbihan (Brittany, France). One site (Locmariaquer, Loc) is coastal and marine while the other (Le bono, BO) located upstream in the Auray river. For each site and specimen, we considered all reservoirs involved in the shell build-up: seawater, internal fluids with hemolymph (H) and extrapaleal fluid (EPF), soft tissues with mantle, muscle and remaining part (R) and finally aragonitic shells. Water d26Mg are -0.82 at Loc and -0.79 at BO and appear to be highly similar to internal fluids values (EPF and H), -0.6 for Loc and -0.8 for BO. The soft tissues with mean values of -2.7 (Mantle), -2.1 (Muscle), -2.8 (R) at both sites, show pronounced enrichments in the light isotopic fraction of Mg. The shells display the widest range of Mg isotopic signatures with -1.9 at Loc and -4.2 at BO suggesting that different routes of fractionation are acting. The shell signature at Loc similar to aragonitic coral (-1.9) suggests that moderate biological effects have influenced the shell composition at this site. In contrast, at BO, the very light signature of the shell suggests that a significant fraction of Mg has been internally recycled by the clam and used for the building of the shell.

  17. [Age-related changes of somatotype and body mass components in girls].

    PubMed

    Tambovtseva, R V; Zhukova, S G

    2005-01-01

    The longitudinal and transverse studies of girls aged 7 to 17 years living in Moscow and the town of Yelabuga were performed to monitor the dynamics of their growth processes, parameters of ectomorphism, mesomorphism and endomorphism depending on the type of body build. Anthropometric, anthroposcopic metods and cluster analysis were used to evaluate the type of body build according to V.G. Shtefko and A.G. Ostrovskiy (1928). Quantitative assessment of parameters of endo-, meso- and ectomorphism was performed using Heath-Carter method (1980). It was shown that the age-related variability of the types of body build appeared in association with the developmental heterochronism, which resulted from the uneven growth rate of different body components. The least variable parameters were found in the girls of digestive and asthenoid types of body build, while in girls of muscular and thoracic types these parameters changed more frequently. The critical periods during which the significant changes of somatotype were increased in number, were defined as 9 to 10 years and puberty period--11 to 14 years. Most sensitive time points in the time-course of somatotype establishment in girls are the ages of 12 and 14 years.

  18. Dissolution Dominating Calcification Process in Polar Pteropods Close to the Point of Aragonite Undersaturation

    PubMed Central

    Bednaršek, Nina; Tarling, Geraint A.; Bakker, Dorothee C. E.; Fielding, Sophie; Feely, Richard A.

    2014-01-01

    Thecosome pteropods are abundant upper-ocean zooplankton that build aragonite shells. Ocean acidification results in the lowering of aragonite saturation levels in the surface layers, and several incubation studies have shown that rates of calcification in these organisms decrease as a result. This study provides a weight-specific net calcification rate function for thecosome pteropods that includes both rates of dissolution and calcification over a range of plausible future aragonite saturation states (Ωar). We measured gross dissolution in the pteropod Limacina helicina antarctica in the Scotia Sea (Southern Ocean) by incubating living specimens across a range of aragonite saturation states for a maximum of 14 days. Specimens started dissolving almost immediately upon exposure to undersaturated conditions (Ωar∼0.8), losing 1.4% of shell mass per day. The observed rate of gross dissolution was different from that predicted by rate law kinetics of aragonite dissolution, in being higher at Ωar levels slightly above 1 and lower at Ωar levels of between 1 and 0.8. This indicates that shell mass is affected by even transitional levels of saturation, but there is, nevertheless, some partial means of protection for shells when in undersaturated conditions. A function for gross dissolution against Ωar derived from the present observations was compared to a function for gross calcification derived by a different study, and showed that dissolution became the dominating process even at Ωar levels close to 1, with net shell growth ceasing at an Ωar of 1.03. Gross dissolution increasingly dominated net change in shell mass as saturation levels decreased below 1. As well as influencing their viability, such dissolution of pteropod shells in the surface layers will result in slower sinking velocities and decreased carbon and carbonate fluxes to the deep ocean. PMID:25285916

  19. Dissolution dominating calcification process in polar pteropods close to the point of aragonite undersaturation.

    PubMed

    Bednaršek, Nina; Tarling, Geraint A; Bakker, Dorothee C E; Fielding, Sophie; Feely, Richard A

    2014-01-01

    Thecosome pteropods are abundant upper-ocean zooplankton that build aragonite shells. Ocean acidification results in the lowering of aragonite saturation levels in the surface layers, and several incubation studies have shown that rates of calcification in these organisms decrease as a result. This study provides a weight-specific net calcification rate function for thecosome pteropods that includes both rates of dissolution and calcification over a range of plausible future aragonite saturation states (Ω(ar)). We measured gross dissolution in the pteropod Limacina helicina antarctica in the Scotia Sea (Southern Ocean) by incubating living specimens across a range of aragonite saturation states for a maximum of 14 days. Specimens started dissolving almost immediately upon exposure to undersaturated conditions (Ω(ar) ∼ 0.8), losing 1.4% of shell mass per day. The observed rate of gross dissolution was different from that predicted by rate law kinetics of aragonite dissolution, in being higher at Ω(ar) levels slightly above 1 and lower at Ω(ar) levels of between 1 and 0.8. This indicates that shell mass is affected by even transitional levels of saturation, but there is, nevertheless, some partial means of protection for shells when in undersaturated conditions. A function for gross dissolution against Ω(ar) derived from the present observations was compared to a function for gross calcification derived by a different study, and showed that dissolution became the dominating process even at Ω(ar) levels close to 1, with net shell growth ceasing at an Ω(ar) of 1.03. Gross dissolution increasingly dominated net change in shell mass as saturation levels decreased below 1. As well as influencing their viability, such dissolution of pteropod shells in the surface layers will result in slower sinking velocities and decreased carbon and carbonate fluxes to the deep ocean.

  20. M2-F1 in flight on tow line

    NASA Technical Reports Server (NTRS)

    1964-01-01

    The M2-F1 Lifting Body is seen here under tow at the Flight Research Center (later redesignated the Dryden Flight Research Center), Edwards, California. The wingless, lifting-body aircraft design was initially concieved as a means of landing an aircraft horizontally after atmospheric reentry. The absence of wings would make the extreme heat of re-entry less damaging to the vehicle. In 1962, Flight Research Center management approved a program to build a lightweight, unpowered lifting body as a prototype to flight test the wingless concept. It would look like a 'flying bathtub,' and was designated the M2-F1, the 'M' referring to 'manned' and 'F' referring to 'flight' version. It featured a plywood shell placed over a tubular steel frame crafted at Dryden. Construction was completed in 1963. The M2-F1 project had limited goals. They were to show that a piloted lifting body could be built, that it could not only fly but be controlled in flight, and that it could make a successful landing. While the M2-F1 did prove the concept, with a wooden fuselage and fixed landing gear, it was far from an operational spacecraft. The next step in the lifting-body development was to build a heavyweight, rocket-powered vehicle that was more like an operational lifting body, albeit one without the thermal protection system that would be needed for reentry into the atmosphere from space at near-orbital speeds. The first flight tests of the M2-F1 were over Rogers Dry Lake at the end of a tow rope attached to a hopped-up Pontiac convertible driven at speeds up to about 120 mph. These initial tests produced enough flight data about the M2-F1 to proceed with flights behind a NASA C-47 tow plane at greater altitudes. The C-47 took the craft to an altitude of 12,000 where free flights back to Rogers Dry Lake began. Pilot for the first series of flights of the M2-F1 was NASA research pilot Milt Thompson. Typical glide flights with the M2-F1 lasted about two minutes and reached speeds of 110 to l20 mph. More than 400 ground tows and 77 aircraft tow flights were carried out with the M2-F1. The success of Dryden's M2-F1 program led to NASA's development and construction of two heavyweight lifting bodies based on studies at NASA's Ames and Langley research centers--the M2-F2 and the HL-10, both built by the Northrop Corporation, and the U.S. Air Force's X-24 program. The Lifting Body program also heavily influenced the Space Shuttle program. The M2-F1 program demonstrated the feasibility of the lifting body concept for horizontal landings of atmospheric entry vehicles. It also demonstrated a procurement and management concept for prototype flight test vehicles that produced rapid results at very low cost (approximately $50,000, excluding salaries of government employees assigned to the project).

  1. Spontaneous Fission Barriers Based on a Generalized Liquid Drop Model

    NASA Astrophysics Data System (ADS)

    Guo, Shu-Qing; Bao, Xiao-Jun; Li, Jun-Qing; Zhang, Hong-Fei

    2014-05-01

    The barrier against the spontaneous fission has been determined within the Generalized Liquid Drop Model (GLDM) including the mass and charge asymmetry, and the proximity energy. The shell correction of the spherical parent nucleus is calculated by using the Strutinsky method, and the empirical shape-dependent shell correction is employed during the deformation process. A quasi-molecular shape sequence has been defined to describe the whole process from one-body shape to two-body shape system, and a two-touching-ellipsoid is adopted when the superdeformed one-body system reaches the rupture point. On these bases the spontaneous fission barriers are systematically studied for nuclei from 230Th to 249Cm for different possible exiting channels with the different mass and charge asymmetries. The double, and triple bumps are found in the fission potential energy in this region, which roughly agree with the experimental results. It is found that at around Sn-like fragment the outer fission barriers are lower, while the partner of the Sn-like fragment is in the range near 108Ru where the ground-state mass is lowered by allowing axially symmetric shapes. The preferable fission channels are distinctly pronounced, which should be corresponding to the fragment mass distributions.

  2. Genetic parameters of egg defects and egg quality in layer chickens.

    PubMed

    Wolc, A; Arango, J; Settar, P; O'Sullivan, N P; Olori, V E; White, I M S; Hill, W G; Dekkers, J C M

    2012-06-01

    Genetic parameters were estimated for egg defects, egg production, and egg quality traits. Eggs from 11,738 purebred brown-egg laying hens were classified as salable or as having one of the following defects: bloody, broken, calcium deposit, dirty, double yolk, misshapen, pee-wee, shell-less, and soft shelled. Egg quality included albumen height, egg weight, yolk weight, and puncture score. Body weight, age at sexual maturity, and egg production were also recorded. Heritability estimates of liability to defects using a threshold animal model were less than 0.1 for bloody and dirty; between 0.1 and 0.2 for pee-wee, broken, misshapen, soft shelled, and shell-less; and above 0.2 for calcium deposit and double yolk. Quality and production traits were more heritable, with estimates ranging from 0.29 (puncture score) to 0.74 (egg weight). High-producing hens had a lower frequency of egg defects. High egg weight and BW were associated with an increased frequency of double yolks, and to a lesser extent, with more shell quality defects. Estimates of genetic correlations among defect traits that were related to shell quality were positive and moderate to strong (0.24-0.73), suggesting that these could be grouped into one category or selection could be based on the trait with the highest heritability or that is easiest to measure. Selection against defective eggs would be more efficient by including egg defect traits in the selection criterion, along with egg production rate of salable eggs and egg quality traits.

  3. Effects of low pH stress on shell traits and proteomes of the dove snail, Anachis misera inhabiting shallow vent environments off Kueishan Islet, Taiwan

    NASA Astrophysics Data System (ADS)

    Chen, Y. J.; Wu, J. Y.; Chen, C. T. A.; Liu, L. L.

    2014-12-01

    The effects of naturally acidified seawater on a snail species, Anachis misera (Family: Columbellidae) were quantified in five shallow vent-based environments off Kueishan Islet, Taiwan. An absence of Anachis snails was observed in the most acidic North site (pH 7.22), and the size structure differed among the remaining East, South, Southwest and Northwest sites. If a positive correlation between shell length and shell width or total weight existed, the coefficient of determination (R2) of the equations was low, i.e., 0.207-0.444. Snails from the Northwest site (pH 7.33) exhibited a more globular shape than those of the South ones (pH 7.80). Standardized shell thickness T1 (thickness of body whorl : shell length) and T2 (thickness of penultimate whorl : shell length) from the Northwest site showed a decrease of 6.3 and 9.4%, respectively, compared to the South ones. In a similar vein, based on the 16 examined protein spots, protein expression profiles of snails in the South were distinct. With further characterization by principle component analysis, the separation was mainly contributed by the first (i.e., spots 8, 1, 15, and 12) and second (i.e., spots 15, 13, 12, 1, and 11) principal-components. As a whole, the shallow vent-based findings provide new information from subtropics on the effects of ocean acidification on gastropod snails in natural environments.

  4. Navier-Stokes predictions of pitch damping for axisymmetric shell using steady coning motion

    NASA Technical Reports Server (NTRS)

    Weinacht, Paul; Sturek, Walter B.; Schiff, Lewis B.

    1991-01-01

    Previous theoretical investigations have proposed that the side force and moment acting on a body of revolution in steady coning motion could be related to the pitch-damping force and moment. In the current research effort, this approach is applied to produce predictions of the pitch damping for axisymmetric shell. The flow fields about these projectiles undergoing steady coning motion are successfully computed using a parabolized Navier-Stokes computational approach which makes use of a rotating coordinate frame. The governing equations are modified to include the centrifugal and Coriolis force terms due to the rotating coordinate frame. From the computed flow field, the side moments due to coning motion, spinning motion, and combined spinning and coning motion are used to determine the pitch-damping coefficients. Computations are performed for two generic shell configurations, a secant-ogive-cylinder and a secant-ogive-cylinder-boattail.

  5. Does Height to Width Ratio Correlate with Mean Volume in Gastropods?

    NASA Astrophysics Data System (ADS)

    Barriga, R.; Seixas, G.; Payne, J.

    2012-12-01

    Marine organisms' shell shape and size show important biological information. For example, shape and size can dictate how the organism ranges for food and escapes predation. Due to lack of data and analysis, the evolution of shell size in marine gastropods (snails) remains poorly known. In this study, I attempt to find the relationship between height to width ratio and mean volume. I collected height and width measurements from primary literature sources and calculated volume from these measurements. My results indicate that there was no correlation between height to width ratio and mean volume between 500 to 200 Ma, but there was a correlation between 200 Ma to present where there is a steady increase in both height to width ratio and mean volume. This means that shell shape was not an important factor at the beginning of gastropod evolution but after 200 Ma body size evolution was increasingly driven by the height to width ratio.

  6. The endoskeletal origin of the turtle carapace

    PubMed Central

    Hirasawa, Tatsuya; Nagashima, Hiroshi; Kuratani, Shigeru

    2013-01-01

    The turtle body plan, with its solid shell, deviates radically from those of other tetrapods. The dorsal part of the turtle shell, or the carapace, consists mainly of costal and neural bony plates, which are continuous with the underlying thoracic ribs and vertebrae, respectively. Because of their superficial position, the evolutionary origins of these costo-neural elements have long remained elusive. Here we show, through comparative morphological and embryological analyses, that the major part of the carapace is derived purely from endoskeletal ribs. We examine turtle embryos and find that the costal and neural plates develop not within the dermis, but within deeper connective tissue where the rib and intercostal muscle anlagen develop. We also examine the fossils of an outgroup of turtles to confirm that the structure equivalent to the turtle carapace developed independently of the true osteoderm. Our results highlight the hitherto unravelled evolutionary course of the turtle shell. PMID:23836118

  7. A developmental and energetic basis linking larval oyster shell formation to acidification sensitivity

    NASA Astrophysics Data System (ADS)

    Waldbusser, George G.; Brunner, Elizabeth L.; Haley, Brian A.; Hales, Burke; Langdon, Christopher J.; Prahl, Frederick G.

    2013-05-01

    Acidified waters are impacting commercial oyster production in the U.S. Pacific Northwest, and favorable carbonate chemistry conditions are predicted to become less frequent. Within 48 h of fertilization, unshelled Pacific oyster (Crassostrea gigas) larvae precipitate roughly 90% of their body weight as calcium carbonate. We measured stable carbon isotopes in larval shell and tissue and in algal food and seawater dissolved inorganic carbon in a longitudinal study of larval development and growth. Using these data and measured biochemical composition of larvae, we show that sensitivity of initial shell formation to ocean acidification results from diminished ability to isolate calcifying fluid from surrounding seawater, a limited energy budget and a strong kinetic demand for calcium carbonate precipitation. Our results highlight an important link between organism physiology and mineral kinetics in larval bivalves and suggest the consideration of mineral kinetics may improve understanding winners and losers in a high CO2 world.

  8. Efficacy of the SU(3) scheme for ab initio large-scale calculations beyond the lightest nuclei

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dytrych, T.; Maris, Pieter; Launey, K. D.

    2016-06-09

    We report on the computational characteristics of ab initio nuclear structure calculations in a symmetry-adapted no-core shell model (SA-NCSM) framework. We examine the computational complexity of the current implementation of the SA-NCSM approach, dubbed LSU3shell, by analyzing ab initio results for 6Li and 12C in large harmonic oscillator model spaces and SU(3)-selected subspaces. We demonstrate LSU3shell's strong-scaling properties achieved with highly-parallel methods for computing the many-body matrix elements. Results compare favorably with complete model space calculations and signi cant memory savings are achieved in physically important applications. In particular, a well-chosen symmetry-adapted basis a ords memory savings in calculations ofmore » states with a fixed total angular momentum in large model spaces while exactly preserving translational invariance.« less

  9. The Names of Heavenly Bodies and Luminaries as a Basis for Word-building and Metaphorical Application in the Poetry of Misak Metzarents

    NASA Astrophysics Data System (ADS)

    Arakelyan, Karine; Santryan, Liana

    2016-12-01

    The metaphorical applications of heavenly bodies and luminaries in the poetry of the famous Western Armenian poet Missak Metsarents are very diverse and of great variety. The poet admired the beauty of nature and the greater parts of his poems are devoted to representation of nature, where heavenly bodies and phenomena are of special interest. They often help to reveal one's inner life, emotions, expectations, and feelings. Many times these units are bases for word-building; new, also poetical words building and they create unique beauty.

  10. Responses to two-way selection on growth in mass-spawned F1 progeny of Argopecten irradians concentricus (Say)

    NASA Astrophysics Data System (ADS)

    Wang, Hui; Liu, Jin; Li, Yanhong; Zhu, Xiaowen; Liu, Zhigang

    2014-03-01

    In the present study, the effect of one-generation divergent selection on the growth and survival of the bay scallop ( Argopecten irradians concentricus) was examined to evaluate the efficacy of a selection program currently being carried out in Beibu Bay in the South China Sea. A total of 146 adult scallops were randomly selected from the same cultured population of A. i. concentricus, and divided into two groups in shell length (anterior-posterior measurement): large (4.91-6.02 cm, n=74) and small (3.31-4.18 cm, n=72). At the same time, a control group was also randomly sampled (4.21-4.88 cm, n =80). Mass-spawned F 1 progenies from the three size groups were obtained and reared under identical conditions at all growth phases. The effects of two-way (or upward-downward) selection on fertilization rate, hatching rate, survival rate, daily growth in shell length and body weight were assessed in the three size groups. Results show that significant differences ( P<0.01) were found in hatching rate, survival rate and daily growth of F1 progenies, but not in fertilization rate ( P>0.05), among the three groups. The hatching rate, survival rate and daily growth of the progeny of large-sized parents were greater than those of the control group ( P<0.05), which in turn were larger than those of small-sized group ( P<0.05). Responses to selection by shell length and body weight were 0.32 ± 0.04 cm and 2.18 ± 0.05 g, respectively, for the upward selection, and -0.14 ± 0.03 cm and -2.77 ± 0.06 g, respectively, for the downward selection. The realized heritability estimates of shell length and body weight were 0.38 ± 0.06 cm and 0.22 ± 0.07 g for the upward selection, and 0.24 ± 0.06 cm and 0.37 ± 0.09 g for the downward selection, respectively. The change in growth by bidirectional selection suggests that high genetic variation may be present in the cultured bay scallop population in China.

  11. Comparative uptake from sea water and tissue distribution of 60Co in marine mollusks

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Carvalho, F.P.

    Five different species of marine mollusks, Mytilus galloprovincialis Lmk., Tapes decussatus L., Cerastoderma (Cardium) edule (L.), Donax vittatus (da Costa) and Patella vulgata L., were exposed to /sup 60/Co-labelled sea water under laboratory conditions. After a 1-mo exposure, tested species reached different whole-body /sup 60/Co concentration factors (CF) over radioactive sea water of 73 +/- 27, 22 +/- 10, 84 +/- 25, 6.3 +/- 1.4 and 31 +/- 10, respectively, which are not dependent upon the size of mollusks. Equations for the experimental uptake curves, obtained using a multi-exponential model, indicate that /sup 60/Co uptake by mollusks involves two ormore » three compartments, according to the species. In all species, the larger compartments turn over with long biological half-lives, dependent upon species. At the beginning of the experiment, /sup 60/CoCl2 added to sea water was mainly in cationic forms. These forms were progressively converted into anionic plus neutral forms most likely due to complex formation with organic ligands. With time this physico-chemical evolution had a lowering effect on /sup 60/Co bioaccumulation by mollusks. Analysis of /sup 60/Co in tissues revealed that Donax shell and mantle do not accumulate the radionuclide in great quantities, generating the low whole-body concentration factor found. In contrast, shell and mantle from all other species displayed variable but high CFs. Shell by itself accounts for more than half of the /sup 60/Co whole-body burden. Among soft tissues, gills and viscera displayed the highest CF and muscle the lowest. From these experiments, one may conclude that significant differences among species do exist regarding Co bioaccumulation potential.« less

  12. Very Facile Polarity Umpolung and Noncovalent Functionalization of Inorganic Nanoparticles: A Tool Kit for Supramolecular Materials Chemistry.

    PubMed

    Zeininger, Lukas; Petzi, Stefanie; Schönamsgruber, Jörg; Portilla, Luis; Halik, Marcus; Hirsch, Andreas

    2015-09-28

    The facile assembly of shell-by-shell (SbS)-coated nanoparticles [TiO2-PAC16]@shell 1-7 (PAC16 = hexadecylphosphonic acid), which are soluble in water and can be isolated as stable solids, is reported. In these functional architectures, an umpolung of dispersibility (organic apolar versus water) was accomplished by the noncovalent binding of ligands 1-7 to titania nanoparticles [TiO2-PAC16] containing a first covalent coating with PAC16. Ligands 1-7 are amphiphilic and form the outer second shell of [TiO2-PAC16]@shell 1-7. The tailor-designed dendritic building blocks 3-5 contain negative and positive charges in the same molecule, and ligands 6 and 7 contain a perylenetetracarboxylic acid dimide (PDI) core (6/7) as a photoactive reporter component. In the redox and photoactive system [TiO2-PAC16]@shell 7, electronic communication between the inorganic core to the PDI ligands was observed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Accurate structure, thermodynamics and spectroscopy of medium-sized radicals by hybrid Coupled Cluster/Density Functional Theory approaches: the case of phenyl radical

    PubMed Central

    Barone, Vincenzo; Biczysko, Malgorzata; Bloino, Julien; Egidi, Franco; Puzzarini, Cristina

    2015-01-01

    The CCSD(T) model coupled with extrapolation to the complete basis-set limit and additive approaches represents the “golden standard” for the structural and spectroscopic characterization of building blocks of biomolecules and nanosystems. However, when open-shell systems are considered, additional problems related to both specific computational difficulties and the need of obtaining spin-dependent properties appear. In this contribution, we present a comprehensive study of the molecular structure and spectroscopic (IR, Raman, EPR) properties of the phenyl radical with the aim of validating an accurate computational protocol able to deal with conjugated open-shell species. We succeeded in obtaining reliable and accurate results, thus confirming and, partly, extending the available experimental data. The main issue to be pointed out is the need of going beyond the CCSD(T) level by including a full treatment of triple excitations in order to fulfil the accuracy requirements. On the other hand, the reliability of density functional theory in properly treating open-shell systems has been further confirmed. PMID:23802956

  14. Single-fabrication-step Ge nanosphere/SiO2/SiGe heterostructures: a key enabler for realizing Ge MOS devices

    NASA Astrophysics Data System (ADS)

    Liao, P. H.; Peng, K. P.; Lin, H. C.; George, T.; Li, P. W.

    2018-05-01

    We report channel and strain engineering of self-organized, gate-stacking heterostructures comprising Ge-nanosphere gate/SiO2/SiGe-channels. An exquisitely-controlled dynamic balance between the concentrations of oxygen, Si, and Ge interstitials was effectively exploited to simultaneously create these heterostructures in a single oxidation step. Process-controlled tunability of the channel length (5–95 nm diameters for the Ge-nanospheres), gate oxide thickness (2.5–4.8 nm), as well as crystal orientation, chemical composition and strain engineering of the SiGe-channel was achieved. Single-crystalline (100) Si1‑x Ge x shells with Ge content as high as x = 0.85 and with a compressive strain of 3%, as well as (110) Si1‑x Ge x shells with Ge content of x = 0.35 and corresponding compressive strain of 1.5% were achieved. For each crystal orientation, our high Ge-content, highly-stressed SiGe shells feature a high degree of crystallinity and thus, provide a core ‘building block’ required for the fabrication of Ge-based MOS devices.

  15. Core–shell grain structures and ferroelectric properties of Na0.5K0.5NbO3–LiTaO3–BiScO3 piezoelectric ceramics

    PubMed Central

    Zhu, Fangyuan; Ward, Michael B.; Li, Jing-Feng; Milne, Steven J.

    2015-01-01

    Legislation arising from health and environmental concerns has intensified research into finding suitable alternatives to lead-based piezoceramics. Recently, solid solutions based on sodium potassium niobate (K,Na)NbO3 (KNN) have become one of the globally-important lead-free counterparts, due to their favourable dielectric and piezoelectric properties. This data article provides information on the ferroelectric properties and core–shell grain structures for the system, (1−y)[(1−x)Na0.5K0.5NbO3 – xLiTaO3] – yBiScO3 (x=0–0.1, y=0.02, abbreviated as KNN–xLT–2BS). We show elemental analysis with aid of TEM spot-EDX to identify three-type grain-types in the KNN–LT–BS ternary system. Melting behaviour has been assessed using a tube furnace with build-in camera. Details for the ferroelectric properties and core–shell chemical segregation are illustrated. PMID:26217758

  16. Single-fabrication-step Ge nanosphere/SiO2/SiGe heterostructures: a key enabler for realizing Ge MOS devices.

    PubMed

    Liao, P H; Peng, K P; Lin, H C; George, T; Li, P W

    2018-05-18

    We report channel and strain engineering of self-organized, gate-stacking heterostructures comprising Ge-nanosphere gate/SiO 2 /SiGe-channels. An exquisitely-controlled dynamic balance between the concentrations of oxygen, Si, and Ge interstitials was effectively exploited to simultaneously create these heterostructures in a single oxidation step. Process-controlled tunability of the channel length (5-95 nm diameters for the Ge-nanospheres), gate oxide thickness (2.5-4.8 nm), as well as crystal orientation, chemical composition and strain engineering of the SiGe-channel was achieved. Single-crystalline (100) Si 1-x Ge x shells with Ge content as high as x = 0.85 and with a compressive strain of 3%, as well as (110) Si 1-x Ge x shells with Ge content of x = 0.35 and corresponding compressive strain of 1.5% were achieved. For each crystal orientation, our high Ge-content, highly-stressed SiGe shells feature a high degree of crystallinity and thus, provide a core 'building block' required for the fabrication of Ge-based MOS devices.

  17. Methodologies for Verification and Validation of Space Launch System (SLS) Structural Dynamic Models

    NASA Technical Reports Server (NTRS)

    Coppolino, Robert N.

    2018-01-01

    Responses to challenges associated with verification and validation (V&V) of Space Launch System (SLS) structural dynamics models are presented in this paper. Four methodologies addressing specific requirements for V&V are discussed. (1) Residual Mode Augmentation (RMA), which has gained acceptance by various principals in the NASA community, defines efficient and accurate FEM modal sensitivity models that are useful in test-analysis correlation and reconciliation and parametric uncertainty studies. (2) Modified Guyan Reduction (MGR) and Harmonic Reduction (HR, introduced in 1976), developed to remedy difficulties encountered with the widely used Classical Guyan Reduction (CGR) method, are presented. MGR and HR are particularly relevant for estimation of "body dominant" target modes of shell-type SLS assemblies that have numerous "body", "breathing" and local component constituents. Realities associated with configuration features and "imperfections" cause "body" and "breathing" mode characteristics to mix resulting in a lack of clarity in the understanding and correlation of FEM- and test-derived modal data. (3) Mode Consolidation (MC) is a newly introduced procedure designed to effectively "de-feature" FEM and experimental modes of detailed structural shell assemblies for unambiguous estimation of "body" dominant target modes. Finally, (4) Experimental Mode Verification (EMV) is a procedure that addresses ambiguities associated with experimental modal analysis of complex structural systems. Specifically, EMV directly separates well-defined modal data from spurious and poorly excited modal data employing newly introduced graphical and coherence metrics.

  18. Understanding valence-shell electron-pair repulsion (VSEPR) theory using origami molecular models

    NASA Astrophysics Data System (ADS)

    Endah Saraswati, Teguh; Saputro, Sulistyo; Ramli, Murni; Praseptiangga, Danar; Khasanah, Nurul; Marwati, Sri

    2017-01-01

    Valence-shell electron-pair repulsion (VSEPR) theory is conventionally used to predict molecular geometry. However, it is difficult to explore the full implications of this theory by simply drawing chemical structures. Here, we introduce origami modelling as a more accessible approach for exploration of the VSEPR theory. Our technique is simple, readily accessible and inexpensive compared with other sophisticated methods such as computer simulation or commercial three-dimensional modelling kits. This method can be implemented in chemistry education at both the high school and university levels. We discuss the example of a simple molecular structure prediction for ammonia (NH3). Using the origami model, both molecular shape and the scientific justification can be visualized easily. This ‘hands-on’ approach to building molecules will help promote understanding of VSEPR theory.

  19. Three-cluster dynamics within an ab initio framework

    DOE PAGES

    Quaglioni, Sofia; Romero-Redondo, Carolina; Navratil, Petr

    2013-09-26

    In this study, we introduce a fully antisymmetrized treatment of three-cluster dynamics within the ab initio framework of the no-core shell model/resonating-group method. Energy-independent nonlocal interactions among the three nuclear fragments are obtained from realistic nucleon-nucleon interactions and consistent ab initio many-body wave functions of the clusters. The three-cluster Schrödinger equation is solved with bound-state boundary conditions by means of the hyperspherical-harmonic method on a Lagrange mesh. We discuss the formalism in detail and give algebraic expressions for systems of two single nucleons plus a nucleus. Using a soft similarity-renormalization-group evolved chiral nucleon-nucleon potential, we apply the method to amore » 4He+n+n description of 6He and compare the results to experiment and to a six-body diagonalization of the Hamiltonian performed within the harmonic-oscillator expansions of the no-core shell model. Differences between the two calculations provide a measure of core ( 4He) polarization effects.« less

  20. Exocomet Signatures Around the A-shell Star Phi Leonis

    NASA Technical Reports Server (NTRS)

    Eiroa, C.; Rebollido, I.; Montesinos, B.; Villaver, E.; Absil, O.; Henning, Th.; Bayo, A.; Canovas, H.; Carmona, A.; Chen, Ch.; hide

    2016-01-01

    We present an intensive monitoring of high-resolution spectra of the Ca II K line in the A7IV shell star Phi Leonis at very short (minutes, hours), short (night to night), and medium (weeks, months) timescales. The spectra show remarkable variable absorptions on timescales of hours, days, and months. The characteristics of these sporadic events are very similar to most that are observed toward the debris disk host star Beta Pictoris, which are commonly interpreted as signs of the evaporation of solid, comet-like bodies grazing or falling onto the star. Therefore, our results suggest the presence of solid bodies around Phi Leonis. To our knowledge, with the exception of Beta Pictoris, our monitoring has the best time resolution at the mentioned timescales for a star with events attributed to exocomets. Assuming the cometary scenario and considering the timescales of our monitoring, our results indicate that Phi Leonis presents the richest environment with comet-like events known to date, second only to Beta Pictoris.

  1. Redescription of the females of Hystrignathus rigidus Leidy, 1850 (Nematoda: Hystrignathidae), parasites of Odontotaenius disjunctus (Coleoptera: Passalidae) from eastern USA.

    PubMed

    Morffe, Jans; García, Nayla; Davis, Andrew K

    2015-03-30

    The female of Hystrignathus rigidus Leidy, 1850 (Nematoda: Hystrignathidae) is redescribed on the basis of new material from Odontotaenius disjunctus (Coleoptera: Passalidae) from Athens, Georgia, USA; which also constitutes a new locality record. SEM images are provided for the first time for the species. It is also first shown that H. rigidus presents ridged-shelled eggs. A differential diagnosis is provided. H. rigidus can be differentiated from the rest of the species of this genus by having a short, non inflated first cephalic annule; spines that surpass the level of the oesophagus, an absence of lateral alae, ridged-shelled eggs and its length of the body and tail. The material from the present study differs from a previous redescription by Christie (1934) by its shorter body (2.125-2.950 vs. 2.130-4.200), first cephalic annule (0.003-0.005 vs. 0.012) and oesophagus (0.350-0.430 vs. 0.650-0.670).

  2. Research and implementation on 3D modeling of geological body

    NASA Astrophysics Data System (ADS)

    Niu, Lijuan; Li, Ligong; Zhu, Renyi; Huang, Man

    2017-10-01

    This study based on GIS thinking explores the combination of the mixed spatial data model and GIS model to build three-dimensional(3d) model of geological bodies in the Arc Engine platform, describes the interface and method used in the construction of 3d geological body in Arc Engine component platform in detail, and puts forward an indirect method which constructs a set of geological grid layers through Rigging interpolation by the borehole data and then converts it into the geological layers of TIN, which improves the defect in building the geological layers of TIN directly and makes it better to complete the simulation of the real geological layer. This study makes a useful attempt to build 3d model of the geological body based on the GIS, and provides a certain reference value for simulating geological bodies in 3d and constructing the digital system of underground space.

  3. Effects of Age and Sex on the Development of Personal Space Schemata Towards Body Build

    ERIC Educational Resources Information Center

    Lerner, Richard M.; And Others

    1975-01-01

    This study assessed personal space schemata of children towards stimulus figures representing male and female body build stereotypes. Greater spatial distances were used towards the Endomorph than other physique types and significant sex differences were found. (GO)

  4. [Wound ballistics of extremely short-range shotguns].

    PubMed

    Rabl, W; Eller, W

    1993-01-01

    A 45-year-old man died from a homicidal shotgun wound of the neck. The autopsy showed that the plastic shell retaining cup had entered the body after the mass of the shot; the dispersion of the individual pellets was about 12 cm already. The perpetrator had used a conventional signal pistol equipped with a hand-made steel barrel, gauge 12, length 20 cm, and ammunition with 3 mm pellets (shot no. 5). By means of experimental shots with a similar weapon it could be proved that the entire shot including the plastic shell retaining cup can penetrate the skin at a muzzle-victim range of less than 2 m.

  5. The mechanism of translational displacements of the core of the Earth at inversion molten and solidification of substance at core-mantle boundary in opposite hemispheres

    NASA Astrophysics Data System (ADS)

    Barkin, Yu. V.

    2009-04-01

    Shell dynamics. "The Earth represents system of non-spherical eccentric shells (the core, the mantle, a rigid core etc.) which have various structure and distribution of density. Their moments of inertia and dynamic oblatenesses are various. From the point of view of the mechanics it means, that external celestial bodies (the Moon and the Sun) on miscellaneous (differentially) gravitationally act on the separate shells. They try to cause various accelerations to the centers of masses of shells and various angular accelerations to their rotary motions. It the most external celestial bodies put shells of forced body in difficult state, forcing them to push each other to prevent each other and to struggle with each other. That is between shells there are powerful force interactions: additional forces, and more significant on value, than tidal forces, and the huge moments of forces which all time aspire to turn one of shells relatively to another. The external influence is stronger, the shells are pressed more strongly or taken away. If external action weakens, also shells mutually exist more quietly. External influence depends on position of perturbing celestial bodies. But the last vary cyclically in various time scales. It means, that interactions of shells with each other also are cyclic with the set of frequencies being a derivative from basic frequencies of orbital motions of celestial bodies (coincide with basic frequencies or are their various combinations). Clearly, that the specified mechanical interactions are as though primary which generate then a sequence of every possible interactions of all layers of shells, geodynamic and geophysical processes (which are naturally also cyclic). Elastic layers will test deformations, thus absorbing, and then returning a mechanical energy of translatory - rotary motion of shells and their relative swing. Plastic properties of layers of shells will result in absorption of mechanical energy and to its transformation to thermal energy. The directed mechanical influences of the bottom shell on top (of the core on the mantle) on geological intervals of time will result in enormous additional variations of the tension state of the top shell, also ordered in space and time (besides in various time scales). This influence will be transferred to all natural processes which will have similar properties of cyclicity and orderliness. Thermodynamic stimulation of layer D " by the relative displacements of the core and mantle will result in formation of ascending mantle streams - plumes. Relative oscillations of the top shells of the Earth with boundaries on depths of 670 km, 430 km and oth. will generate the fluid formations (lenses and chambers) from a magmatic materials and fusions. Ascending fluid streams in the top mantle on system of breaks and cracks move in the top layers and on a surface of the Earth. So magmatic and volcanic activity of the Earth is realized. Over this activity again "supervise" mutually - displaced and deformed shells of the Earth. The last, in turn, are in strict "submission" at the Moon and the Sun and «are sensitively listen» to the slightest changes of their orbital motions." (Barkin, 2002, pp. 45, 46). "The powerful impacts repeating cyclically, on zones of a congestion of fluid masses (astenosphere lenses, magmatic chambers etc.) result in their growth and expansion, and at significant subsequent impacts to a effects of wedging of the top layers of lithosphere and the crust, i.e. to formation of new or to stimulation and expansion of old cracks and lineaments. Subsequent or more powerful impacts (influences) of the bottom shell on a direction of wedging will result in transport of molten mantle substances from the bottom layers in top, including outpourings of magmas and other fluids on a surface of a planet (the Earth). " (Barkin, 2002, with. 47). The mechanism of formation of plums and hot spots. "The most significant displacements of the centers of mass of shells of the Earth result in the most significant variations of the intense condition of a transitive layer between the core and the mantle and overlying layers of the mantle. A capacity of layer D", covering makes a liquid nucleus about 250 km. It, apparently, is determined by extreme displacements of a liquid core relatively to the mantle (original active sphere of its influence). The appropriate relative displacements of the centers of mass of the core and the mantle (certainly, on geological intervals of time) thus can achieve kilometers. Cyclic displacements of a liquid core with various amplitudes and frequencies result to heating of all layer D" (or the certain zones of this layer) and to downturn of its density. Layer D" passes as though in the excited state. Its temperature raises its thickness and surpluses of heated masses under an impact of the bottom shell (the core), apparently, is increased start to rise along the weakened radial zones in the top levels of standing. To formation of the similar weakened zones is promoted also by mechanical influence of the bottom shell of the mantle. Thus the plums are formed, bringing heated substance to the uppermost layers of the mantle. At catastrophic interactions of shells the plums promote carrying out of magmas directly on a surface of the Earth. Actually the theoretical illustration here is given to known representation, that layer D" is "kitchen of inner plate magmatism» (Zonenshain, Kuzmin, 1993). Similar processes occur on boundaries of other shells of the Earth. The intensification of interactions of shells on boundaries of 430 km, 670 km and even in more high levels results in formation of zones of fusions, astenosphere lenses and to that of similar formations which promote volcanic activity of the Earth. At the intensive swing of shells the top layers of the Earth (of lithosphere) are exposed by hydraulic wedging (Khain, Lomise, 1995). As a result of the specified long process there is a formation of system of cracks and breaks, hot spots and their systems on the Earth surface etc. It is natural, that by virtue of the ordered cyclic displacements of shells the specified geological structures also will have properties of orderliness (Barkin, 2000)." (Barkin, 2002, p. 78). The thermodynamic mechanism. In the report the new thermodynamic mechanism of the contrast phenomena of fusion of a frontier layer of a sole of the mantle (in northern hemisphere) to which the core is forced to be displaced, and solidification of zones of a liquid core from the opposite side (in a southern hemisphere) is discussed. This mechanism is hypothetical, but it rather logically explains observably contrast temperature modes of hemispheres in modern and the last geological epoch, the source of plume material which moves specifies (is redistributed) to the top layers and a surface of the Earth, i.e. the mechanism of plume-tectonic activity of the Earth. Plum-tectonic activity of the core drifting and varying with a wide spectrum of frequencies relatively to the mantle, in a long time scale results in contrast variations of geodynamic conditions in N/S hemispheres. The specified polar oscillations of the core and mantle during geoevolution have left after themselves geological certificates on a surface of the Earth about inversion changes of geodynamic and geological conditions in opposite hemispheres (Bozhko, 1992). Such huge bodies as the core and mantle of the Earth as a result of oscillations, deformations and relative displacements easily transformed a face of the Earth: formed N/S orientated rifting structures, resulted in the directed and organized motions of lithosphere plates, more intensively warmed up that southern northern hemispheres, operated by ocean, deforming its bottom and raising or lowering its mean level due to the tide from a displaced core. The specified processes are long and occur, including, in a geological time scale. It means that the fundamental tectonic process of formation of supercontinents also has a polar orientation, is cyclic. Our modeling researches have shown, that relative oscillations of the core and mantle arise even at absence of strongly pronounced thermodynamic transformations of a material on CMB due to viscous elastic properties of all layers of the mantle (Barkin, Vilke, 2004). The formulated positions require detailed study from positions of the mechanics and thermodynamics. It is possible to assume, that action of this mechanism precisely should be shown and in a short time scale, for example, at annual and monthly oscillations of the core. It means that cyclic variations of thermal flows from the Earth with the specified periods, and with contrast thermal flows in relation to northern and southern hemispheres should be observed. The core trend also should be displayed in contrast secular changes of thermal flows and in variations of temperatures at a surface of the Earth and in various layers of ocean and an atmosphere. Confirmations to these preliminary conclusions in particular is yielded with results of modern researches of temperature changes in an atmosphere and a stratosphere (Fred Singer, 2001 [2]; Douglass, Pearson, Fred Singer, Knappenberger, Michaals, 2008). References Singer S.F. (2001) Disparity of temperature trends (1979-99) of atmosphere and surface. 12th Symposium on Global Climate Variations. 14-19 Jan. 2001, Albuquerque. Barkin Yu.V. (2002) An explanation of endogenous activity of planets and satellites and its cyclisity. Isvestia sekcii nauk o Zemle Rossiiskoi akademii ectestvennykh nauk. Vyp. 9, M., VINITI, pp. 45-97. In Russian.

  6. Synthesis and Characterization of Microencapsulated Phase Change Materials with Poly(urea-urethane) Shells Containing Cellulose Nanocrystals.

    PubMed

    Yoo, Youngman; Martinez, Carlos; Youngblood, Jeffrey P

    2017-09-20

    The main objective of this study is to develop microencapsulation technology for thermal energy storage incorporating a phase change material (PCM) in a composite wall shell, which can be used to create a stable environment and allow the PCM to undergo phase change without any outside influence. Surface modification of cellulose nanocrystals (CNCs) was conducted by grafting poly(lactic acid) oligomers and oleic acid to improve the dispersion of nanoparticles in a polymeric shell. A microencapsulated phase change material (methyl laurate) with poly(urea-urethane) (PU) composite shells containing the hydrophobized cellulose nanocrystals (hCNCs) was fabricated using an in situ emulsion interfacial polymerization process. The encapsulation process of the PCMs with subsequent interfacial hCNC-PU to form composite microcapsules as well as their morphology, composition, thermal properties, and release rates was examined in this study. Oil soluble Sudan II dye solution in methyl laurate was used as a model hydrophobic fill, representing other latent fills with low partition coefficients, and their encapsulation efficiency as well as dye release rates were measured spectroscopically in a water medium. The influence of polyol content in the PU polymer matrix of microcapsules was investigated. An increase in polyol contents leads to an increase in the mean size of microcapsules but a decrease in the gel content (degree of cross-linking density) and permeability of their shell structure. The encapsulated PCMs for thermal energy storage demonstrated here exhibited promising performance for possible use in building or paving materials in terms of released heat, desired phase transformation temperature, chemical and physical stability, and concrete durability during placement.

  7. Ageing and exercise: building body capital in old age.

    PubMed

    Bergland, Astrid; Fougner, Marit; Lund, Anne; Debesay, Jonas

    2018-01-01

    Research that provides better understanding of the motivational processes in older age to maintain a healthy and active lifestyle is sought after. We apply theoretical approaches to cultural capital, active and healthy aging health to shed light on the women's experiences in maintaining physical capabilities through an active lifestyle, and thereby facilitating their own inclusion in society. Thus, the aim of this paper is to explore why older home dwelling women over the age of 70 years or more spend time in physical exercise and their experiences about the importance of participating in group exercise for their daily life.This paper reports on a qualitative study based on interviews with 16 older women aged 70 years or more and regularly attending group exercise classes in the community at an established workout center. The data were analyzed the data using an inductive content analysis approach. Three overreaching and interrelated themes emerged from the interviews: "Building body capital for independence", "Building body capital to maintain vitality and being in control" and "Building resources for social interaction". The findings suggest that group exercise is important for building body capital. The group exercise helped the women in building bodily ability to manage everyday life, maintain vitality, being in control, pursue social interaction and live independently. These body resources were important for these older women's experience of the manageability and meaningfulness of daily life. This study has provided insights into older women's understanding and experiences of the challenges of everyday life within a theoretical framework of cultural capital and health. The women acquired cultural health capital, and more specifically body capital, by participating in the group exercise classes. The women's investment in body capital through regular physical activity created resources which facilitated social participation. Therefore professionals need to be aware of this when performing group exercise.

  8. Sea shell diversity and rapidly evolving secretomes: insights into the evolution of biomineralization.

    PubMed

    Kocot, Kevin M; Aguilera, Felipe; McDougall, Carmel; Jackson, Daniel J; Degnan, Bernard M

    2016-01-01

    An external skeleton is an essential part of the body plan of many animals and is thought to be one of the key factors that enabled the great expansion in animal diversity and disparity during the Cambrian explosion. Molluscs are considered ideal to study the evolution of biomineralization because of their diversity of highly complex, robust and patterned shells. The molluscan shell forms externally at the interface of animal and environment, and involves controlled deposition of calcium carbonate within a framework of macromolecules that are secreted from the dorsal mantle epithelium. Despite its deep conservation within Mollusca, the mantle is capable of producing an incredible diversity of shell patterns, and macro- and micro-architectures. Here we review recent developments within the field of molluscan biomineralization, focusing on the genes expressed in the mantle that encode secreted proteins. The so-called mantle secretome appears to regulate shell deposition and patterning and in some cases becomes part of the shell matrix. Recent transcriptomic and proteomic studies have revealed marked differences in the mantle secretomes of even closely-related molluscs; these typically exceed expected differences based on characteristics of the external shell. All mantle secretomes surveyed to date include novel genes encoding lineage-restricted proteins and unique combinations of co-opted ancient genes. A surprisingly large proportion of both ancient and novel secreted proteins containing simple repetitive motifs or domains that are often modular in construction. These repetitive low complexity domains (RLCDs) appear to further promote the evolvability of the mantle secretome, resulting in domain shuffling, expansion and loss. RLCD families further evolve via slippage and other mechanisms associated with repetitive sequences. As analogous types of secreted proteins are expressed in biomineralizing tissues in other animals, insights into the evolution of the genes underlying molluscan shell formation may be applied more broadly to understanding the evolution of metazoan biomineralization.

  9. The Mind-Body Building Equation.

    ERIC Educational Resources Information Center

    Dryfoos, Joy

    2000-01-01

    Full-service community schools combine three concepts--mind, body, and building--into an integrated approach placing quality education and comprehensive support services at one site. The DeWitt Wallace-Reader's Digest Fund is helping schools and communities replicate 4 such programs at 60 sites in 20 U.S. cities. (MLH)

  10. Hypersonic research engine project. Phase 2: Aerothermodynamic integration model development

    NASA Technical Reports Server (NTRS)

    Jilly, L. F. (Editor)

    1971-01-01

    The fabrication of the various components of the HRE AIM was completed. The purge system necessary for the cavity bounded by the outer shell assembly and the outer cowl body was studied. Preparations were begun for establishing a format for test data acquisition and reduction.

  11. PRSEUS Pressure Cube Test Data and Response

    NASA Technical Reports Server (NTRS)

    Lovejoy, Andrew E.

    2013-01-01

    NASA s Environmentally Responsible Aviation (ERA) Program is examining the hybrid wing body (HWB) aircraft, among others, in an effort to increase the fuel efficiency of commercial aircraft. The HWB design combines features of a flying wing with features of conventional transport aircraft, and has the advantage of simultaneously increasing both fuel efficiency and payload. Recent years have seen an increased focus on the structural performance of the HWB. The key structural challenge of a HWB airframe is the ability to create a cost and weight efficient, non-circular, pressurized shell. Conventional round fuselage sections react cabin pressure by hoop tension. However, the structural configuration of the HWB subjects the majority of the structural panels to bi-axial, in-plane loads in addition to the internal cabin pressure, which requires more thorough examination and analysis than conventional transport aircraft components having traditional and less complex load paths. To address this issue, while keeping structural weights low, extensive use of advanced composite materials is made. This report presents the test data and preliminary conclusions for a pressurized cube test article that utilizes Boeing's Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS), and which is part of the building block approach used for HWB development.

  12. Clumped isotope paleothermometry of eggshells as an indicator of vertebrate endothermy

    NASA Astrophysics Data System (ADS)

    Canavan, R. R.; Field, D. J.; Therrien, F.; Zelenitsky, D.; Affek, H. P.

    2014-12-01

    Isotopic analyses of the calcite or aragonite shells of aquatic organisms are often used in the study of the environmental conditions in which they grow; however, this approach is less straightforward in the terrestrial realm, where environments may be more heterogeneous. In such terrestrial localities, the bioapatite of vertebrate teeth comprises the typical archival material for isotopic analyses. The calcitic eggshells of birds and other reptiles may provide suitable material for isotopic analyses that are aimed at studying their physiology and ecology. Here we apply a novel thermometer, carbonate clumped isotopes (Δ47), to test for endothermy in extinct non-avian dinosaurs in the context provided by eggs of modern reptiles and birds. These Δ47-derived temperatures should reflect the temperature of shell formation, which in endothermic animals such as birds should represent the mother's internal body temperature. In ectothermic animals, the same is true although their body temperatures are more affected by the external environment and thus Δ47 temperatures could more accurately describe local environmental temperatures during eggshell formation. Fossil eggshells represent appropriate material for reconstructing internal body temperatures of extinct non-avian dinosaurs since they mineralized within the mother's body, and fragments of eggshell are commonly recovered from dinosaur-bearing fossil deposits. The dimensions of these fragments provide sufficient material for the relatively large sample required for clumped isotope analysis (~20mg). Fossil eggshell samples from several taxa of Late Cretaceous non-avian dinosaurs were analyzed using Δ47 paleothermometry. Textural inspection was used as a first test for diagenetic alteration of the original calcite, and histological indicators were used for broad taxonomic identifications. Preliminary results of Δ47-derived body temperature estimates from eggshells are consistent with previous body temperatures estimates from bioapatite Δ47 analyses performed on non-avian dinosaur teeth.

  13. Nanoscale semiconductor-insulator-metal core/shell heterostructures: facile synthesis and light emission.

    PubMed

    Li, Gong Ping; Chen, Rui; Guo, Dong Lai; Wong, Lai Mun; Wang, Shi Jie; Sun, Han Dong; Wu, Tom

    2011-08-01

    Controllably constructing hierarchical nanostructures with distinct components and designed architectures is an important theme of research in nanoscience, entailing novel but reliable approaches of bottom-up synthesis. Here, we report a facile method to reproducibly create semiconductor-insulator-metal core/shell nanostructures, which involves first coating uniform MgO shells onto metal oxide nanostructures in solution and then decorating them with Au nanoparticles. The semiconductor nanowire core can be almost any material and, herein, ZnO, SnO(2) and In(2)O(3) are used as examples. We also show that linear chains of short ZnO nanorods embedded in MgO nanotubes and porous MgO nanotubes can be obtained by taking advantage of the reduced thermal stability of the ZnO core. Furthermore, after MgO shell-coating and the appropriate annealing treatment, the intensity of the ZnO near-band-edge UV emission becomes much stronger, showing a 25-fold enhancement. The intensity ratio of the UV/visible emission can be increased further by decorating the surface of the ZnO/MgO nanowires with high-density plasmonic Au nanoparticles. These heterostructured semiconductor-insulator-metal nanowires with tailored morphologies and enhanced functionalities have great potential for use as nanoscale building blocks in photonic and electronic applications. This journal is © The Royal Society of Chemistry 2011

  14. Pharmaceutical 3D printing: Design and qualification of a single step print and fill capsule.

    PubMed

    Smith, Derrick M; Kapoor, Yash; Klinzing, Gerard R; Procopio, Adam T

    2018-06-10

    Fused deposition modeling (FDM) 3D printing (3DP) has a potential to change how we envision manufacturing in the pharmaceutical industry. A more common utilization for FDM 3DP is to build upon existing hot melt extrusion (HME) technology where the drug is dispersed in the polymer matrix. However, reliable manufacturing of drug-containing filaments remains a challenge along with the limitation of active ingredients which can sustain the processing risks involved in the HME process. To circumvent this obstacle, a single step FDM 3DP process was developed to manufacture thin-walled drug-free capsules which can be filled with dry or liquid drug product formulations. Drug release from these systems is governed by the combined dissolution of the FDM capsule 'shell' and the dosage form encapsulated in these shells. To prepare the shells, the 3D printer files (extension '.gcode') were modified by creating discrete zones, so-called 'zoning process', with individual print parameters. Capsules printed without the zoning process resulted in macroscopic print defects and holes. X-ray computed tomography, finite element analysis and mechanical testing were used to guide the zoning process and printing parameters in order to manufacture consistent and robust capsule shell geometries. Additionally, dose consistencies of drug containing liquid formulations were investigated in this work. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Dual shell-like magnetic clusters containing Ni(II) and Ln(III) (Ln = La, Pr, and Nd) ions.

    PubMed

    Kong, Xiang-Jian; Ren, Yan-Ping; Long, La-Sheng; Zheng, Zhiping; Nichol, Gary; Huang, Rong-Bin; Zheng, Lan-Sun

    2008-04-07

    Dual shell-like nanoscopic magnetic clusters featuring a polynuclear nickel(II) framework encapsulating that of lanthanide ions (Ln = La, Pr, and Nd) were synthesized using Ni(NO3)(2).6H2O, Ln(NO3)(3).6H2O, and iminodiacetic acid (IDA) under hydrothermal conditions. Structurally established by crystallographic studies, these clusters are [La20Ni30(IDA)30(CO3)6(NO3)6(OH)30(H2O)12](CO3)(6).72H2O (1), [Ln20Ni21(C4H5NO4)21(OH)24(C2H2O3)6(C2O4)3(NO3)9(H2O)12](NO3)9.nH2O [C2H2O3 is the alkoxide form of glycolate; Ln = Pr (2), n = 42; Nd (3), n = 50], and {[La4Ni5Na(IDA)5(CO3)(NO3)4(OH)5(H2O)5][CO3].10H2O} infinity (4). Carbonate, oxalate, and glycolate are products of hydrothermal decomposition of IDA. Compositions of these compounds were confirmed by satisfactory elemental analyses. It has been found that the cluster structure is dependent on the identity of the lanthanide ion as well as the starting Ln/Ni/IDA ratio. The cationic cluster of 1 features a core of the Keplerate type with an outer icosidodecahedron of Ni(II) ions encaging a dodecahedral kernel of La(III). Clusters 2 and 3, distinctly different from 1, are isostructural, possessing a core of an outer shell of 21 Ni(II) ions encapsulating an inner shell of 20 Ln(III) ions. Complex 4 is a three-dimensional assembly of cluster building blocks connected by units of Na(NO3)/La(NO3)3; the structure of the building block resembles closely that of 1, with a hydrated La(III) ion internalized in the decanuclear cage being an extra feature. Magnetic studies indicated ferromagnetic interactions in 1, while overall antiferromagnetic interactions were revealed for 2 and 3. The polymeric, three-dimensional cluster network 4 displayed interesting ferrimagnetic interactions.

  16. Penecontemporaneous metamorphism, fragmentation, and reassembly of ordinary chondrite parent bodies

    NASA Technical Reports Server (NTRS)

    Grimm, R. E.

    1985-01-01

    The thermal histories of ordinary chondrites and the canonical internal heating or onion shell models, which predict an inverse relation between the petrologic type of chondrites and the metallographic cooling rate, are reviewed. The thermal and accretional requirements of the 'metamorphosed planetesimal' model proposed by Scott and Rajan (1981) are analyzed, and an alternative model consistent with the metallographic cooling rate constraints is suggested in which ordinary chondrite parent bodies are collisionally fragmented and then rapidly reassembled before metamorphic heat has been dissipated.

  17. Inhalation Exposure to Jet Fuel (JP8) Among U.S. Air Force Personnel

    DTIC Science & Technology

    2010-10-01

    less Ihan 25 ft > grrater tlulII 25 I t). primary job (entranl > (IIItlldomirum.er/jireglloro > Oil /side IWllgar), (HId performillg I"Orious tasks...collect vapor samples on coconut shell chareoal in tWQ.scction (100 mg/50 mg) glass sorbcnt tubes (Anasorb; SKC Inc .. Eighty Four. Pa.) at a now...dermal JP8 exposure study (~) assessed three body surfaces, additional body regions were not assessed in this study to minimize the burden Oil study

  18. Shell feature: a new radiomics descriptor for predicting distant failure after radiotherapy in non-small cell lung cancer and cervix cancer

    NASA Astrophysics Data System (ADS)

    Hao, Hongxia; Zhou, Zhiguo; Li, Shulong; Maquilan, Genevieve; Folkert, Michael R.; Iyengar, Puneeth; Westover, Kenneth D.; Albuquerque, Kevin; Liu, Fang; Choy, Hak; Timmerman, Robert; Yang, Lin; Wang, Jing

    2018-05-01

    Distant failure is the main cause of human cancer-related mortalities. To develop a model for predicting distant failure in non-small cell lung cancer (NSCLC) and cervix cancer (CC) patients, a shell feature, consisting of outer voxels around the tumor boundary, was constructed using pre-treatment positron emission tomography (PET) images from 48 NSCLC patients received stereotactic body radiation therapy and 52 CC patients underwent external beam radiation therapy and concurrent chemotherapy followed with high-dose-rate intracavitary brachytherapy. The hypothesis behind this feature is that non-invasive and invasive tumors may have different morphologic patterns in the tumor periphery, in turn reflecting the differences in radiological presentations in the PET images. The utility of the shell was evaluated by the support vector machine classifier in comparison with intensity, geometry, gray level co-occurrence matrix-based texture, neighborhood gray tone difference matrix-based texture, and a combination of these four features. The results were assessed in terms of accuracy, sensitivity, specificity, and AUC. Collectively, the shell feature showed better predictive performance than all the other features for distant failure prediction in both NSCLC and CC cohorts.

  19. Drill Holes and Predation Traces versus Abrasion-Induced Artifacts Revealed by Tumbling Experiments

    PubMed Central

    Gorzelak, Przemysław; Salamon, Mariusz A.; Trzęsiok, Dawid; Niedźwiedzki, Robert

    2013-01-01

    Drill holes made by predators in prey shells are widely considered to be the most unambiguous bodies of evidence of predator-prey interactions in the fossil record. However, recognition of traces of predatory origin from those formed by abiotic factors still waits for a rigorous evaluation as a prerequisite to ascertain predation intensity through geologic time and to test macroevolutionary patterns. New experimental data from tumbling various extant shells demonstrate that abrasion may leave holes strongly resembling the traces produced by drilling predators. They typically represent singular, circular to oval penetrations perpendicular to the shell surface. These data provide an alternative explanation to the drilling predation hypothesis for the origin of holes recorded in fossil shells. Although various non-morphological criteria (evaluation of holes for non-random distribution) and morphometric studies (quantification of the drill hole shape) have been employed to separate biological from abiotic traces, these are probably insufficient to exclude abrasion artifacts, consequently leading to overestimate predation intensity. As a result, from now on, we must adopt more rigorous criteria to appropriately distinguish abrasion artifacts from drill holes, such as microstructural identification of micro-rasping traces. PMID:23505530

  20. Heterozygosity and fitness: No strong association in Great Lakes populations of the zebra mussel, Dreissena Polymorpha (Pallas)

    USGS Publications Warehouse

    Lewis, K.M.; Feder, J.L.; Horvath, T.G.; Lamberti, G.A.

    2000-01-01

    A number of studies have found positive associations between allozyme heterozygosity and fitness surrogates (e.g., body size and growth rate) for marine molluscs. We investigated whether similar relationships exist for freshwater populations of the zebra mussel, Dreissena polymorpha. Only one significant correlation between multi-locus heterozygosity and shell length was observed for a total of 22 D. polymorpha populations surveyed from midwestern U.S.A. lakes and streams, and the result was not significant on a table-wide basis. Meta-analysis revealed a significant common correlation coefficient (effect magnitude) between multi-locus heterozygosity and shell length across all 22 sites (rc = 0.052, P = 0.019, 1557 df). However, the variance in shell length explained by multi-locus heterozygosity was small (rc2 = 0.0027), implying a weak causal relationship if any. Also, we saw no relationship between heterozygosity and growth rate in a one-year field enclosure experiment. A significant heterozygosity-shell length correlation previously reported for a zebra mussel population at Put-in-Bay, Lake Erie, Ohio, may have been the product of unique population dynamics, rather than natural selection. Similar demographic considerations may contribute to inconsistencies in heterozygosity-fitness correlations seen for other molluscs.

  1. Fireworks type, injury pattern, and permanent impairment following severe fireworks-related injuries.

    PubMed

    Sandvall, Brinkley K; Jacobson, Lauren; Miller, Erin A; Dodge, Ryan E; Alex Quistberg, D; Rowhani-Rahbar, Ali; Vavilala, Monica S; Friedrich, Jeffrey B; Keys, Kari A

    2017-10-01

    There is a paucity of clinical data on severe fireworks-related injuries, and the relationship between firework types, injury patterns, and magnitude of impairment is not well understood. Our objective was to describe the relationship between fireworks type, injury patterns, and impairment. Retrospective case series (2005-2015) of patients who sustained consumer fireworks-related injuries requiring hospital admission and/or an operation at a Level 1 Trauma/Burn Center. Fireworks types, injury patterns (body region, injury type), operation, and permanent impairment were examined. Data from 294 patients 1 to 61years of age (mean 24years) were examined. The majority (90%) were male. 119 (40%) patients were admitted who did not undergo surgery, 163 (55%) patients required both admission and surgery, and 12 (5%) patients underwent outpatient surgery. The greatest proportion of injuries was related to shells/mortars (39%). There were proportionally more rocket injuries in children (44%), more homemade firework injuries in teens (34%), and more shell/mortar injuries in adults (86%). Brain, face, and hand injuries were disproportionately represented in the shells/mortars group. Seventy percent of globe-injured patients experienced partial or complete permanent vision loss. Thirty-seven percent of hand-injured patients required at least one partial or whole finger/hand amputation. The greatest proportion of eye and hand injuries resulting in permanent impairment was in the shells/mortars group, followed by homemade fireworks. Two patients died. Severe fireworks-related injuries from homemade fireworks and shells/mortars have specific injury patterns. Shells/mortars disproportionately cause permanent impairment from eye and hand injury. Published by Elsevier Inc.

  2. Portable tomographic PIV measurements of swimming shelled Antarctic pteropods

    NASA Astrophysics Data System (ADS)

    Adhikari, Deepak; Webster, Donald R.; Yen, Jeannette

    2016-12-01

    A portable tomographic particle image velocimetry (tomographic PIV) system is described. The system was successfully deployed in Antarctica to study shelled Antarctic pteropods ( Limacina helicina antarctica)—a delicate organism with an unusual propulsion mechanism. The experimental setup consists of a free-standing frame assembled with optical rails, thus avoiding the need for heavy and bulky equipment (e.g. an optical table). The cameras, lasers, optics, and tanks are all rigidly supported within the frame assembly. The results indicate that the pteropods flap their parapodia (or "wings") downward during both power and recovery strokes, which is facilitated by the pitching of their shell. Shell pitching significantly alters the flapping trajectory, allowing the pteropod to move vertically and/or horizontally. The pronation and supination of the parapodia, together with the figure-eight motion during flapping, suggest similarities with insect flight. The volumetric velocity field surrounding the freely swimming pteropod reveals the generation of an attached vortex ring connecting the leading-edge vortex to the trailing-edge vortex during power stroke and a presence of a leading-edge vortex during recovery stroke. These vortex structures play a major role in accelerating the organism vertically and indicate that forces generated on the parapodia during flapping constitute both lift and drag. After completing each stroke, two vortex rings are shed into the wake of the pteropod. The complex combination of body kinematics (parapodia flapping, shell pitch, sawtooth trajectory), flow structures, and resulting force balance may be significantly altered by thinning of the pteropod shell, thus making pteropods an indicator of the detrimental effects of ocean acidification.

  3. Photovoltaic building sheathing element with anti-slide features

    DOEpatents

    Keenihan, James R.; Langmaid, Joseph A.; Lopez, Leonardo C.

    2015-09-08

    The present invention is premised` upon an assembly that includes at least a photovoltaic building sheathing element capable of being affixed on a building structure, the photovoltaic building sheathing element. The element including a photovoltaic cell assembly, a body portion attached to one or more portions of the photovoltaic cell assembly; and at feast a first and a second connector assembly capable of directly or indirectly electrically connecting the photovoltaic cell assembly to one or more adjoining devices; wherein the body portion includes one or more geometric features adapted to engage a vertically adjoining device before installation.

  4. Tectonics of icy satellites driven by melting and crystallization of water bodies inside their ice shells

    NASA Astrophysics Data System (ADS)

    Johnston, Stephanie Ann

    Enceladus and Europa are icy satellites that currently support bodies of liquid water in the outer solar system Additionally, they show signs of being geologically active. Developing numerical models informed by observations of these icy satellites allows for the development of additional constraints and an improved understanding of the tectonics and evolution of icy satellites. The formation mechanisms for both chaos and ridges on Europa are thought to involve water as albedo changes observed in association with them imply the deposition of salt-rich water near these features. Ridges are the most ubiquitous feature on Europa and are described as central troughs flanked by two raised edifices, range in height from tens to hundreds of meters. Europan ridges can extend hundreds of km continuously along strike but are only about 2 km across. A model of a crystallizing dike--like water intrusion is able to match the overall morphology of ridges, and is consistent the long continuous strike. However, the intrusion of a large volume of water is required to match the most common heights of the ridges. Chaos on Europa is defined as a large area of disrupted ice that contain blocks of pre-existing material separated by a hummocky matrix. A proposed mechanism for the formation of Chaos is that a region of heterogeneous ice within the shell is melted and then recrystallizes. Comparing the model results with the geology of Thera Macula, a region where it has been proposed that Chaos is currently forming, suggests that additional processes may be needed to fully understand the development of Chaos. Water-rich plumes erupt from the south pole of Enceladus, suggesting the presence of a pressurized water reservoir. If a pressurized sea is located beneath the south polar terrain, its geometry and size in the ice shell would contribute to the stress state in the ice shell. The geometry and location of such an ocean, as well as the boundary conditions and thickness of an ice shell have important implications for the faulting and tectonic deformation anticipated at the surface.

  5. Body Build Perceptions in Male and Female College Students.

    ERIC Educational Resources Information Center

    Bailey, Roger C.; Hankins, Norman E.

    1979-01-01

    Results from scores on the Somatotype Rating Scale (SRS) indicated that, while there was close agreement between males and females on the measures, females exhibited more dissatisfaction with their body build and greater congruency between their self-concept and their same-sex stereotype than did males. (Author)

  6. 29 CFR 782.6 - Mechanics.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    .... Hayes Freight Lines, 71 F. Supp. 755 (work of janitor and caretaker, carpentry work, body building.... 846 (body building, construction work, painting and lettering); Hutchinson v. Barry, 50 F. Supp. 292.... Tenn.), 1 Wage Hour Cases 920 (painter), reversed on other grounds 124 F. (2d) 549; Green v. Riss & Co...

  7. 6. VIEW LOOKING NORTHWEST FROM THE IMAGE LEFT TO THE ...

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

    6. VIEW LOOKING NORTHWEST FROM THE IMAGE LEFT TO THE IMAGE RIGHT IS THE CHARCOAL HOUSE, THE RETORT SHED IN THE BACKGROUND, THE MILL ANNEX, THE MACHINE SHOP, AND THE ELECTRIC MOTOR ROOM. THE MILL BUILDING IS IN THE BACKGROUND CENTER RIGHT AND ONE OF THE ORE DELIVERY TRESTLES EXTENDING FROM THE MILL BUILDING TO RIGHT IMAGE EDGE. - Standard Gold Mill, East of Bodie Creek, Northeast of Bodie, Bodie, Mono County, CA

  8. Ancient techniques for new materials

    NASA Technical Reports Server (NTRS)

    2000-01-01

    NASA is looking to biological techniques that are millions of years old to help it develop new materials and technologies for the 21st century. Sponsored by NASA, Jeffrey Brinker of the University of New Mexico is studying how multiple elements can assemble themselves into a composite material that is clear, tough, and impermeable. His research is based on the model of how an abalone builds the nacre, also called mother-of-pearl, inside its shell. The mollusk layers bricks of calcium carbonate (the main ingredient in classroom chalk) and mortar of biopolymer to form a new material (top and bottom left) that is twice as hard and 1,000 times as tough as either of the original building materials.

  9. Microgravity

    NASA Image and Video Library

    2000-12-15

    NASA is looking to biological techniques that are millions of years old to help it develop new materials and technologies for the 21st century. Sponsored by NASA, Jeffrey Brinker of the University of New Mexico is studying how multiple elements can assemble themselves into a composite material that is clear, tough, and impermeable. His research is based on the model of how an abalone builds the nacre, also called mother-of-pearl, inside its shell. The mollusk layers bricks of calcium carbonate (the main ingredient in classroom chalk) and mortar of biopolymer to form a new material (top and bottom left) that is twice as hard and 1,000 times as tough as either of the original building materials.

  10. Sexually dichromatic coloration reflects size and immunocompetence in female Spanish terrapins, Mauremys leprosa

    NASA Astrophysics Data System (ADS)

    Ibáñez, Alejandro; Marzal, Alfonso; López, Pilar; Martín, José

    2013-12-01

    Many studies have shown the importance of colorful ornamentation in mate choosiness or intrasexual conflict. However, research on color ornaments has focused mainly on birds, lizards or fish, but remains practically unknown in other animal groups such as turtles. In addition, female ornaments and their relation with sexual selection also remain almost unknown. Here, we measured the coloration of the shell and the limb stripes of male and female Spanish terrapins Mauremys leprosa and explored the existence of sexual dichromatism and the relation of color characteristics with body size and health state estimated from the immune response to the injection of an antigen (phytohaemagglutinin test). Our results showed that shell coloration, which could be constrained by natural selection to be cryptic, changed with body size, but did not differ between sexes. In contrast, females had brighter and less ultraviolet-saturated and more orange-saturated limb stripes than males. In females, interindividual variation in limb stripe coloration was related with body size and immune response suggesting that this coloration may inform honestly about multiple traits that could be important in sexual selection. In contrast, coloration of limb stripes of males was duller than in females, and was not related with any trait suggesting that coloration is not important in sexual selection for males.

  11. Houses need to breathe--right?

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sherman, Max H.

    2004-10-01

    Houses need to breathe, but we can no longer leave the important functions associated with ventilation to be met accidentally. A designed ventilation system must be considered as much a part of a home as its heating system. Windows are a key part of that system because they allow a quick increase in ventilation for unusual events, but neither they nor a leaky building shell can be counted on to provide minimum levels.

  12. Communication: Programmable self-assembly of thin-shell mesostructures

    DOE PAGES

    Halverson, Jonathan D.; Tkachenko, Alexei V.

    2017-10-13

    For this article, we study numerically the possibility of programmable self-assembly of various thin-shell architectures. They include clusters isomorphic to fullerenes C 20 and C 60, finite and infinite sheets, tube-shaped and toroidal mesostructures. Our approach is based on the recently introduced directionally functionalized nanoparticle platform, for which we employ a hybrid technique of Brownian dynamics with stochastic bond formation. By combining a number of strategies, we were able to achieve a near-perfect yield of the desired structures with a reduced “alphabet” of building blocks. Among those strategies are the following: the use of bending rigidity of the interparticle bondmore » as a control parameter, programming the morphology with a seed architecture, use of chirality-preserving symmetries for reduction of the particle alphabet, and the hierarchic approach.« less

  13. Combined Effects of Diurnal and Nonsynchronous Surface Stresses on Europa

    NASA Technical Reports Server (NTRS)

    Stempel, M. M.; Pappalardo, R. T.; Wahr, J.; Barr, A. C.

    2004-01-01

    To date, modeling of the surface stresses on Europa has considered tidal, nonsynchronous, and polar wander sources of stress. The results of such models can be used to match lineament orientations with candidate stress patterns. We present a rigorous surface stress model for Europa that will facilitate comparison of principal stresses to lineament orientation, and which will be available in the public domain. Nonsynchronous rotation and diurnal motion contribute to a stress pattern that deforms the surface of Europa. Over the 85-hour orbital period, the diurnal stress pattern acts on the surface, with a maximum magnitude of approximately 0.1 MPa. The nonsynchronous stress pattern sweeps over the surface due to differential rotation of the icy shell relative to the tidally locked interior of the moon. Nonsynchronous stress builds cumulatively with approximately 0.1 MPa per degree of shell rotation.

  14. Communication: Programmable self-assembly of thin-shell mesostructures

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Halverson, Jonathan D.; Tkachenko, Alexei V.

    For this article, we study numerically the possibility of programmable self-assembly of various thin-shell architectures. They include clusters isomorphic to fullerenes C 20 and C 60, finite and infinite sheets, tube-shaped and toroidal mesostructures. Our approach is based on the recently introduced directionally functionalized nanoparticle platform, for which we employ a hybrid technique of Brownian dynamics with stochastic bond formation. By combining a number of strategies, we were able to achieve a near-perfect yield of the desired structures with a reduced “alphabet” of building blocks. Among those strategies are the following: the use of bending rigidity of the interparticle bondmore » as a control parameter, programming the morphology with a seed architecture, use of chirality-preserving symmetries for reduction of the particle alphabet, and the hierarchic approach.« less

  15. Body Build Stereotypes and Self-Identification in Three Age Groups of Females.

    ERIC Educational Resources Information Center

    Brenner, David; Hinsdale, Gary

    1978-01-01

    Body build stereotypes of average-weight and heavy females, ages 6, 15, and 19, were studied through adjective checklists and drawings of endomorphs, ectomorphs, and mesomorphs. Mesomorph drawings were favored and the endomorphs least liked. But heavy subjects rejected for themselves behavioral stereotypes previously applied to the endomorph…

  16. Shell structure and distribution of Cloudina, a potential index fossil for the terminal Proterozoic

    NASA Technical Reports Server (NTRS)

    Grant, S. W.; Knoll, A. H. (Principal Investigator)

    1990-01-01

    Cloudina-bearing biosparites and biomicrites in the lower part of the Nama Group, Namibia, contain a wide morphological diversity of shell fragments that can all be attributed to the two named species C. hartmannae and C. riemkeae. The curved to sinuous tubular shells of Cloudina were multi-layered. Each shell layer was 8 to 50 micrometers thick and in the form of a slightly flaring tube with one end open and the other closed. Growth appears to have been periodic with successive shell layers forming within older layers. Each added layer was slightly elevated from the previous layer at the proximal end and was asymmetrically placed within the older layer so that only a portion of the new shell layer was fused to the previous layer. This type of growth left a relatively large unminerialized area between the shell layers which was often partially or fully occluded by early marine cements. The thin shell layers exhibit both plastic and brittle deformation and were likely formed of a rigid CaCO3-impregnated organic-rich material. Often the shell layers are preferentially dolomitized suggesting an original mineralogy of high-magnesian calcite. Both species in the Nama Group formed thickets, or perhaps bioherms, and this sedentary and gregarious habit suggests that Cloudina was probably a filter-feeding metazoan of at least a cnidarian grade of organization. The unusual shell structure of Cloudina gives rise to a characteristic suite of taphonomic and diagenetic features that can be used to identify Cloudina-bearing deposits within the Nama Group and in other terminal Proterozoic deposits around the world. Species of Cloudina occur in limestones from Brazil, Spain, China, and Oman in sequences consistent with a latest Proterozoic age assignment. In addition, supposed lower Cambrian, pre-trilobitic, shelly fossils from northwest Mexico and the White-Inyo Mountains in California and Nevada, including Sinotubulites, Nevadatubulus, and Wyattia, are all either closely related to or con-generic with Cloudina. Hence, it is probable that these outcrops are latest Proterozoic in age, and that Cloudina or Cloudina-like organisms were widely distributed at that time. It is possible, moreover, to suggest that metazoan biomineralization occurred on a global scale by the latest Proterozoic, at the same time that evidence for complex multicellularity and locomotion in animals appears in siliciclastic "Ediacaran" rocks in the form of body and trace fossils.

  17. Lewy Body Disease

    MedlinePlus

    Lewy body disease is one of the most common causes of dementia in the elderly. Dementia is the loss of mental ... to affect normal activities and relationships. Lewy body disease happens when abnormal structures, called Lewy bodies, build ...

  18. Casimir self-entropy of a spherical electromagnetic δ -function shell

    NASA Astrophysics Data System (ADS)

    Milton, Kimball A.; Kalauni, Pushpa; Parashar, Prachi; Li, Yang

    2017-10-01

    In this paper we continue our program of computing Casimir self-entropies of idealized electrical bodies. Here we consider an electromagnetic δ -function sphere ("semitransparent sphere") whose electric susceptibility has a transverse polarization with arbitrary strength. Dispersion is incorporated by a plasma-like model. In the strong-coupling limit, a perfectly conducting spherical shell is realized. We compute the entropy for both low and high temperatures. The transverse electric self-entropy is negative as expected, but the transverse magnetic self-entropy requires ultraviolet and infrared renormalization (subtraction), and, surprisingly, is only positive for sufficiently strong coupling. Results are robust under different regularization schemes. These rather surprising findings require further investigation.

  19. Continuum and three-nucleon force effects on Be 9 energy levels

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Langhammer, Joachim; Navrátil, Petr; Quaglioni, Sofia

    2015-02-05

    In this paper, we extend the recently proposed ab initio no-core shell model with continuum to include three-nucleon (3N) interactions beyond the few-body domain. The extended approach allows for the assessment of effects of continuum degrees of freedom as well as of the 3N force in ab initio calculations of structure and reaction observables of p- and lower-sd-shell nuclei. As a first application we concentrate on energy levels of the 9Be system for which all excited states lie above the n- 8Be threshold. For all energy levels, the inclusion of the continuum significantly improves the agreement with experiment, which wasmore » an issue in standard no-core shell model calculations. Furthermore, we find the proper treatment of the continuum indispensable for reliable statements about the quality of the adopted 3N interaction from chiral effective field theory. Finally, in particular, we find the 1/2 + resonance energy, which is of astrophysical interest, in good agreement with experiment.« less

  20. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gomez, John A.; Henderson, Thomas M.; Scuseria, Gustavo E.

    Restricted single-reference coupled cluster theory truncated to single and double excitations accurately describes weakly correlated systems, but often breaks down in the presence of static or strong correlation. Good coupled cluster energies in the presence of degeneracies can be obtained by using a symmetry-broken reference, such as unrestricted Hartree-Fock, but at the cost of good quantum numbers. A large body of work has shown that modifying the coupled cluster ansatz allows for the treatment of strong correlation within a single-reference, symmetry-adapted framework. The recently introduced singlet-paired coupled cluster doubles (CCD0) method is one such model, which recovers correct behavior formore » strong correlation without requiring symmetry breaking in the reference. Here, we extend singlet-paired coupled cluster for application to open shells via restricted open-shell singlet-paired coupled cluster singles and doubles (ROCCSD0). The ROCCSD0 approach retains the benefits of standard coupled cluster theory and recovers correct behavior for strongly correlated, open-shell systems using a spin-preserving ROHF reference.« less

  1. Commentary: The Feasibility of Subduction and Implications for Plate Tectonics on Jupiter's Moon Europa

    NASA Astrophysics Data System (ADS)

    Kattenhorn, Simon A.

    2018-03-01

    A new modeling-based study by Johnson et al. (2017, https://doi.org/10.1002/2017JE005370) lends support to the hypothesis that portions of Europa's surface may have been removed by the process of subduction, as suggested by Kattenhorn and Prockter (2014, https://doi.org/10.1038/NGEO2245). Using a simple 1-D model that tracks the thermal and density structure of a descending ice plate, Johnson et al. show that ice plates with 10% porosity and overall salt contents of 5%, which differ in salt content by 2.5% from the surrounding reference ice shell, are nonbuoyant and thus likely to sink through the underlying, convecting portion of the ice shell. The feasibility of subduction in an ice shell is critical to the existence of icy plate tectonics, which is hypothesized to exist at least locally on Europa, potentially making it the only other Solar System body other than Earth with a surface modified by plate tectonics.

  2. Quantification of eggshell microstructure using X-ray micro computed tomography

    PubMed Central

    Riley, A.; Sturrock, C. J.; Mooney, S. J.

    2014-01-01

    1. X-ray microcomputed tomography can be used to produce rapid, fully analysable, three-dimensional images of biological and other materials without the need for complex or tedious sample preparation and sectioning. We describe the use of this technique to visualise and analyse the microstructure of fragments of shell taken from three regions of chicken eggs (sharp pole, blunt pole and equatorial region). 2. Two- and three-dimensional images and data were obtained at a resolution of 1.5 microns. The images were analysed to provide measurements of shell thickness, the spacial density of mammillary bodies, the frequency, shape, volume and effective diameter of individual pore spaces, and the intrinsic sponginess (proportion of non-X-ray dense material formed by vesicles) of the shell matrix. Measurements of these parameters were comparable with those derived by traditional methods and reported in the literature. 3. The advantages of using this technology for the quantification of eggshell microstructural parameters and its potential application for commercial, research and other purposes are discussed. PMID:24875292

  3. Perfect fluid Lagrangian and its cosmological implications in theories of gravity with nonminimally coupled matter fields

    NASA Astrophysics Data System (ADS)

    Avelino, P. P.; Azevedo, R. P. L.

    2018-03-01

    In this paper we show that the on-shell Lagrangian of a perfect fluid depends on microscopic properties of the fluid, giving specific examples of perfect fluids with different on-shell Lagrangians but with the same energy-momentum tensor. We demonstrate that if the fluid is constituted by localized concentrations of energy with fixed rest mass and structure (solitons) then the average on-shell Lagrangian of a perfect fluid is given by Lm=T , where T is the trace of the energy-momentum tensor. We show that our results have profound implications for theories of gravity where the matter Lagrangian appears explicitly in the equations of motion of the gravitational and matter fields, potentially leading to observable deviations from a nearly perfect cosmic microwave background black body spectrum: n -type spectral distortions, affecting the normalization of the spectral energy density. Finally, we put stringent constraints on f (R ,Lm) theories of gravity using the COBE-FIRAS measurement of the spectral radiance of the cosmic microwave background.

  4. Biocompatible core-shell magnetic nanoparticles for cancer treatment

    NASA Astrophysics Data System (ADS)

    Sharma, Amit; Qiang, You; Meyer, Daniel; Souza, Ryan; Mcconnaughoy, Alan; Muldoon, Leslie; Baer, Donald

    2008-04-01

    Nontoxic magnetic nanoparticles (MNPs) have expanded treatment delivery options in the medical world. With a size range from 2to200nm, MNPs can be compiled with most of the small cells and tissues in the living body. Monodispersive iron-iron oxide core-shell nanoparticles were prepared by our novel cluster deposition system. This unique method of preparing core-shell MNPs gives the nanoparticles a very high magnetic moment. We tested the nontoxicity and uptake of MNPs coated with/without dextrin by incubating them with rat LX-1 small cell lung cancer cells. Since core iron enhances the heating effect [L. Baker, Q. Zeing, W. Li, and S. Sullivan, J. Appl. Phys. 99, 08H106 (2006)], the rate of oxidation of iron nanoparticles was also tested in de-ionized water at a certain time interval. Both coated and noncoated MNPs were successfully uptaken by the cells, indicating that the nanoparticles were not toxic. The stability of MNPs was verified by x-ray diffraction scan after 0, 24, 48, 96, and 204h. Due to the high magnetic moment offered by MNPs produced in our laboratory, we predict that even at low applied external alternating field, the desired temperature could be reached in cancer cells in comparison to the commercially available nanoparticles. Moreover our MNPs do not require additional transfection agent, providing a cost effective means of treatment with significantly lower dosage in the body in comparison to commercially available nanoparticles.

  5. A three-compartment thermometry model for the improved estimation of changes in body heat content.

    PubMed

    Jay, Ollie; Gariépy, Louise M; Reardon, Francis D; Webb, Paul; Ducharme, Michel B; Ramsay, Tim; Kenny, Glen P

    2007-01-01

    The aim of this study was to use whole body calorimetry to directly measure the change in body heat content (DeltaH(b)) during steady-state exercise and compare these values with those estimated using thermometry. The thermometry models tested were the traditional two-compartment model of "core" and "shell" temperatures, and a three-compartment model of "core," "muscle," and "shell" temperatures; with individual compartments within each model weighted for their relative influence upon DeltaH(b) by coefficients subject to a nonnegative and a sum-to-one constraint. Fifty-two participants performed 90 min of moderate-intensity exercise (40% of Vo(2 peak)) on a cycle ergometer in the Snellen air calorimeter, at regulated air temperatures of 24 degrees C or 30 degrees C and a relative humidity of either 30% or 60%. The "core" compartment was represented by temperatures measured in the esophagus (T(es)), rectum (T(re)), and aural canal (T(au)), while the "muscle" compartment was represented by regional muscle temperature measured in the vastus lateralis (T(vl)), triceps brachii (T(tb)), and upper trapezius (T(ut)). The "shell" compartment was represented by the weighted mean of 12 skin temperatures (T(sk)). The whole body calorimetry data were used to derive optimally fitting two- and three-compartment thermometry models. The traditional two-compartment model was found to be statistically biased, systematically underestimating DeltaH(b) by 15.5% (SD 31.3) at 24 degrees C and by 35.5% (SD 21.9) at 30 degrees C. The three-compartment model showed no such bias, yielding a more precise estimate of DeltaH(b) as evidenced by a mean estimation error of 1.1% (SD 29.5) at 24 degrees C and 5.4% (SD 30.0) at 30 degrees C with an adjusted R(2) of 0.48 and 0.51, respectively. It is concluded that a major source of error in the estimation of DeltaH(b) using the traditional two-compartment thermometry model is the lack of an expression independently representing the heat storage in muscle during exercise.

  6. Influence of riverine input on the growth of Glycymeris glycymeris in the Bay of Brest, North-West France

    PubMed Central

    2017-01-01

    A crossdated, replicated, chronology of 114 years (1901–2014) was developed from internal growth increments in the shells of Glycymeris glycymeris samples collected monthly from the Bay of Brest, France. Bivalve sampling was undertaken between 2014 and 2015 using a dredge. In total 401 live specimens and 243 articulated paired valves from dead specimens were collected, of which 38 individuals were used to build the chronology. Chronology strength, assessed as the Expressed Population Signal, was above 0.7 throughout, falling below the generally accepted threshold of 0.85 before 1975 because of reduced sample depth. Significant positive correlations were identified between the shell growth and the annual averages of rainfall (1975–2008; r = 0.34) and inflow from the river Elorn (1989–2009; r = 0.60). A significant negative correlation was identified between shell growth and the annual average salinity (1998–2014; r = -0.62). Analysis of the monthly averages indicates that these correlations are associated with the winter months (November–February) preceding the G. glycymeris growth season suggesting that winter conditions predispose the benthic environment for later shell growth. Concentration of suspended particulate matter within the river in February is also positively correlated with shell growth, leading to the conclusion that food availability is also important to the growth of G. glycymeris in the Bay of Brest. With the addition of principle components analysis, we were able to determine that inflow from the River Elorn, nitrite levels and salinity were the fundamental drivers of G. glycymeris growth and that these environmental parameters were all linked. PMID:29261749

  7. Shell worlds

    NASA Astrophysics Data System (ADS)

    Roy, Kenneth I.; Kennedy, Robert G., III; Fields, David E.

    2013-02-01

    The traditional concept of terraforming assumes ready availability of candidate planets with acceptable qualities: orbiting a star in its "Goldilocks zone", liquid water, enough mass, years longer than days, magnetic field, etc. But even stipulating affordable interstellar travel, we still might never find a good candidate elsewhere. Whatever we found likely would require centuries of heavy terraforming, just as Mars or Venus would here. Our increasing appreciation of the ubiquity of life suggests that any terra nova would already possess it. We would then face the dilemma of introducing alien life forms (us, our microbes) into another living world. Instead, we propose a novel method to create habitable environments for humanity by enclosing airless, sterile, otherwise useless planets, moons, and even large asteroids within engineered shells, which avoids the conundrum. These shells are subject to two opposing internal stresses: compression due to the primary's gravity, and tension from atmospheric pressure contained inside. By careful design, these two cancel each other resulting in zero net shell stress. Beneath the shell an Earth-like environment could be created similar in almost all respects to that of Home, except for gravity, regardless of the distance to the sun or other star. Englobing a small planet, moon, or even a dwarf planet like Ceres, would require astronomical amounts of material (quadrillions of tons) and energy, plus a great deal of time. It would be a quantum leap in difficulty over building Dyson Dots or industrializing our solar system, perhaps comparable to a mission across interstellar space with a living crew within their lifetime. But when accomplished, these constructs would be complete (albeit small) worlds, not merely large habitats. They could be stable across historic timescales, possibly geologic. Each would contain a full, self-sustaining ecology, which might evolve in curious directions over time. This has interesting implications for SETI as well.

  8. Characterization of an aluminum alloy hemispherical shell fabricated via direct metal laser melting

    DOE PAGES

    Holesinger, T. G.; Carpenter, J. S.; Lienert, T. J.; ...

    2016-01-11

    The ability of additive manufacturing to directly fabricate complex shapes provides characterization challenges for part qualification. The orientation of the microstructures produced by these processes will change relative to the surface normal of a complex part. In this work, the microscopy and x-ray tomography of an AlSi10Mg alloy hemispherical shell fabricated using powder bed metal additive manufacturing are used to illustrate some of these challenges. The shell was manufactured using an EOS M280 system in combination with EOS-specified powder and process parameters. The layer-by-layer process of building the shell with the powder bed additive manufacturing approach results in a position-dependentmore » microstructure that continuously changes its orientation relative to the shell surface normal. X-ray tomography was utilized to examine the position-dependent size and distribution of porosity and surface roughness in the 98.6% dense part. Optical and electron microscopy were used to identify global and local position-dependent structures, grain morphologies, chemistry, and precipitate sizes and distributions. The rapid solidification processes within the fusion zone (FZ) after the laser transit results in a small dendrite size. Cell spacings taken from the structure in the middle of the FZ were used with published relationships to estimate a cooling rate of ~9 × 10 5 K/s. Uniformly-distributed, nanoscale Si precipitates were found within the primary α-Al grains. A thin, distinct boundary layer containing larger α-Al grains and extended regions of the nanocrystalline divorced eutectic material surrounds the FZ. Moreover, subtle differences in the composition between the latter layer and the interior of the FZ were noted with scanning transmission electron microscopy (STEM) spectral imaging.« less

  9. Characterization of an Aluminum Alloy Hemispherical Shell Fabricated via Direct Metal Laser Melting

    NASA Astrophysics Data System (ADS)

    Holesinger, T. G.; Carpenter, J. S.; Lienert, T. J.; Patterson, B. M.; Papin, P. A.; Swenson, H.; Cordes, N. L.

    2016-03-01

    The ability of additive manufacturing to directly fabricate complex shapes provides characterization challenges for part qualification. The orientation of the microstructures produced by these processes will change relative to the surface normal of a complex part. In this work, the microscopy and x-ray tomography of an AlSi10Mg alloy hemispherical shell fabricated using powder bed metal additive manufacturing are used to illustrate some of these challenges. The shell was manufactured using an EOS M280 system in combination with EOS-specified powder and process parameters. The layer-by-layer process of building the shell with the powder bed additive manufacturing approach results in a position-dependent microstructure that continuously changes its orientation relative to the shell surface normal. X-ray tomography was utilized to examine the position-dependent size and distribution of porosity and surface roughness in the 98.6% dense part. Optical and electron microscopy were used to identify global and local position-dependent structures, grain morphologies, chemistry, and precipitate sizes and distributions. The rapid solidification processes within the fusion zone (FZ) after the laser transit results in a small dendrite size. Cell spacings taken from the structure in the middle of the FZ were used with published relationships to estimate a cooling rate of ~9 × 105 K/s. Uniformly-distributed, nanoscale Si precipitates were found within the primary α-Al grains. A thin, distinct boundary layer containing larger α-Al grains and extended regions of the nanocrystalline divorced eutectic material surrounds the FZ. Subtle differences in the composition between the latter layer and the interior of the FZ were noted with scanning transmission electron microscopy (STEM) spectral imaging.

  10. Efficient workflows for 3D building full-color model reconstruction using LIDAR long-range laser and image-based modeling techniques

    NASA Astrophysics Data System (ADS)

    Shih, Chihhsiong

    2005-01-01

    Two efficient workflow are developed for the reconstruction of a 3D full color building model. One uses a point wise sensing device to sample an unknown object densely and attach color textures from a digital camera separately. The other uses an image based approach to reconstruct the model with color texture automatically attached. The point wise sensing device reconstructs the CAD model using a modified best view algorithm that collects the maximum number of construction faces in one view. The partial views of the point clouds data are then glued together using a common face between two consecutive views. Typical overlapping mesh removal and coarsening procedures are adapted to generate a unified 3D mesh shell structure. A post processing step is then taken to combine the digital image content from a separate camera with the 3D mesh shell surfaces. An indirect uv mapping procedure first divide the model faces into groups within which every face share the same normal direction. The corresponding images of these faces in a group is then adjusted using the uv map as a guidance. The final assembled image is then glued back to the 3D mesh to present a full colored building model. The result is a virtual building that can reflect the true dimension and surface material conditions of a real world campus building. The image based modeling procedure uses a commercial photogrammetry package to reconstruct the 3D model. A novel view planning algorithm is developed to guide the photos taking procedure. This algorithm successfully generate a minimum set of view angles. The set of pictures taken at these view angles can guarantee that each model face shows up at least in two of the pictures set and no more than three. The 3D model can then be reconstructed with minimum amount of labor spent in correlating picture pairs. The finished model is compared with the original object in both the topological and dimensional aspects. All the test cases show exact same topology and reasonably low dimension error ratio. Again proving the applicability of the algorithm.

  11. Hollow spheres: crucial building blocks for novel nanostructures and nanophotonics

    NASA Astrophysics Data System (ADS)

    Zhong, Kuo; Song, Kai; Clays, Koen

    2018-03-01

    In this review, we summarize the latest developments in research specifically derived from the unique properties of hollow microspheres, in particular, hollow silica spheres with uniform shells. We focus on applications in nanosphere (colloidal) lithography and nanophotonics. The lithography from a layer of hollow spheres can result in nanorings, from a multilayer in unique nano-architecture. In nanophotonics, disordered hollow spheres can result in antireflection coatings, while ordered colloidal crystals (CCs) of hollow spheres exhibit unique refractive index enhancement upon infiltration, ideal for optical sensing. Furthermore, whispering gallery mode (WGM) inside the shell of hollow spheres has also been demonstrated to enhance light absorption to improve the performance of solar cells. These applications differ from the classical applications of hollow spheres, based only on their low density and large surface area, such as catalysis and chemical sensing. We provide a brief overview of the synthesis and self-assembly approaches of the hollow spheres. We elaborate on their unique optical features leading to defect mode lasing, optomicrofluidics, and the existence of WGMs inside shell for light management. Finally, we provide a perspective on the direction towards which future research relevant to hollow spheres might be directed.

  12. Structural Configuration Analysis of Crew Exploration Vehicle Concepts

    NASA Technical Reports Server (NTRS)

    Mukhopadhyay, V.

    2006-01-01

    Structural configuration modeling and finite element analysis of crew exploration vehicle (CEV) concepts are presented. In the structural configuration design approach, parametric solid models of the pressurized shell and tanks are developed. The CEV internal cabin pressure is same as in the International Space Station (ISS) to enable docking with the ISS without an intermediate airlock. Effects of this internal pressure load on the stress distribution, factor of safety, mass and deflections are investigated. Uniform 7 mm thick skin shell, 5 mm thick shell with ribs and frames, and isogrid skin construction options are investigated. From this limited study, the isogrid construction appears to provide most strength/mass ratio. Initial finite element analysis results on the service module tanks are also presented. These rapid finite element analyses, stress and factor of safety distribution results are presented as a part of lessons learned and to build up a structural mass estimation and sizing database for future technology support. This rapid structural analysis process may also facilitate better definition of the vehicles and components for rapid prototyping. However, these structural analysis results are highly conceptual and exploratory in nature and do not reflect current configuration designs being conducted at the program level by NASA and industry.

  13. Structural fluctuation governed dynamic diradical character in pentacene.

    PubMed

    Yang, Hongfang; Chen, Mengzhen; Song, Xinyu; Bu, Yuxiang

    2015-06-07

    We unravel intriguing dynamical diradical behavior governed by structural fluctuation in pentacene using ab initio molecular dynamics simulation. In contrast to static equilibrium configuration of pentacene with a closed-shell ground state without diradical character, due to structural fluctuation, some of its dynamical snapshot configurations exhibit an open-shell broken-symmetry singlet ground state with diradical character, and such diradical character presents irregular pulsing behavior in time evolution. Not all structural changes can lead to diradical character, only those involving the shortening of cross-linking C-C bonds and variations of the C-C bonds in polyacetylene chains are the main contributors. This scenario about diradicalization is distinctly different from that in long acenes. The essence is that structural distortion cooperatively raises the HOMO and lowers the LUMO, efficiently reducing the HOMO-LUMO and singlet-triplet energy gaps, which facilitate the formation of a broken-symmetry open-shell singlet state. The irregular pulsing behavior originates from the mixing of normal vibrations in pentacene. This fascinating behavior suggests the potential application of pentacene as a suitable building block in the design of new electronic devices due to its magnetism-controllability through energy induction. This work provides new insight into inherent electronic property fluctuation in acenes.

  14. Design of Ski Boots for Alpine Ski Racing Based on Leg Frame of the Skier

    NASA Astrophysics Data System (ADS)

    Suzuki, Soichiro; Hayashi, Sueyoshi

    A ski boot is important to make progress in ski turning technique as an interface between a skier and a ski. Especially in alpine ski races, suitability of design of the boots for racers becomes more important to achieve accurate and quick lean of the leg in ski turns. This study is aimed at building a new design concept of a ski boot that can improve the results of alpine ski races. In this paper, new design of an upper shell of a ski boot that was adjusted to the features of the frame of alpine ski racers was experimentally examined. As a result, it was demonstrated that a front and a rear part of the upper shell of a ski boot should be separately adjusted to the length of a shank of each player for well-balanced quick lean of the leg in the ski turn. Finally, the effect of new design of an upper shell was examined in giant slalom and slalom tests by Japanese alpine ski racers of the first rank. Consequently, the results showed that lean angle during turns was increased and finish time was shortened when the skiers wore the newly designed boots.

  15. Ultrasonic Apparatus and Method to Assess Compartment Syndrome

    NASA Technical Reports Server (NTRS)

    Yost, William T. (Inventor); Ueno, Toshiaki (Inventor); Hargens, Alan R. (Inventor)

    2009-01-01

    A process and apparatus for measuring pressure buildup in a body compartment that encases muscular tissue. The method includes assessing the body compartment configuration and identifying the effect of pulsatible components on compartment dimensions and muscle tissue characteristics. This process is used in preventing tissue necrosis, and in decisions of whether to perform surgery on the body compartment for prevention of Compartment Syndrome. An apparatus is used for measuring pressure build-up in the body compartment having components for imparting ultrasonic waves such as a transducer, placing the transducer to impart the ultrasonic waves, capturing the imparted ultrasonic waves, mathematically manipulating the captured ultrasonic waves and categorizing pressure build-up in the body compartment from the mathematical manipulations.

  16. Overcoming the fragility - X-ray computed micro-tomography elucidates brachiopod endoskeletons.

    PubMed

    Seidel, Ronald; Lüter, Carsten

    2014-01-01

    The calcareous shells of brachiopods offer a wealth of informative characters for taxonomic and phylogenetic investigations. In particular scanning electron microscopy (SEM) has been used for decades to visualise internal structures of the shell. However, to produce informative SEM data, brachiopod shells need to be opened after chemical removal of the soft tissue. This preparation occasionally damages the shell. Additionally, skeletal elements of taxonomic/systematic interest such as calcareous spicules which are loosely embedded in the lophophore and mantle connective tissue become disintegrated during the preparation process. Using a nondestructive micro-computed tomography (μCT) approach, the entire fragile endoskeleton of brachiopods is documented for the first time. New insights on the structure and position of tissue-bound skeletal elements (spicules) are given as add ons to existing descriptions of brachiopod shell anatomy, thereby enhancing the quality and quantity of informative characters needed for both taxonomic and phylogenetic studies. Here, we present five modern, articulated brachiopods (Rectocalathis schemmgregoryi n. gen., n. sp., Eucalathis sp., Gryphus vitreus, Liothyrella neozelanica and Terebratulina retusa) that were X-rayed using a Phoenix Nanotom XS 180 NF. We provide links to download 3D models of these species, and additional five species with spicules can be accessed in the Supplemental Material. In total, 17 brachiopod genera covering all modern articulated subgroups and 2 inarticulated genera were X-rayed for morphological analysis. Rectocalathis schemmgregoryi n. gen., n. sp. is fully described. Micro-CT is an excellent non-destructive tool for investigating calcified structures in the exo- and endoskeletons of brachiopods. With high quality images and interactive 3D models, this study provides a comprehensive description of the profound differences in shell anatomy, facilitates the detection of new delicate morphological characters of the endoskeleton and gives new insights into the body plan of modern brachiopods.

  17. Europa's Great Lakes

    NASA Astrophysics Data System (ADS)

    Schmidt, B. E.; Blankenship, D. D.; Patterson, G. W.; Schenk, P. M.

    2012-04-01

    Unique to the surface of Europa, chaos terrain is diagnostic of the properties and dynamics of its icy shell. While models have suggested that partial melt within a thick shell or melt-through of a thin shell may form chaos, neither model has been able to definitively explain all observations of chaos terrain. However, we present a new model that suggests large melt lenses form within the shell and that water-ice interactions above and within these lenses drive the production of chaos. Our analysis of the geomorphology of Conamara Chaos and Thera Macula, was used to infer and test a four-stage lens-collapse chaos formation model: 1) Thermal plumes of warm, pure ice ascend through the shell melting the impure brittle ice above, producing a lake of briny water and surface down draw due to volume reduction. 2) Surface deflection and driving force from the plume below hydraulically seals the water in place. 3) Extension of the brittle ice lid generates fractures from below, allowing brines to enter and fluidize the ice matrix. 4) As the lens and now brash matrix refreeze, thermal expansion creates domes and raises the chaos feature above the background terrain. This new "lense-collapse" model indicates that chaos features form in the presence of a great deal of liquid water, and that large liquid water bodies exist within 3km of Europa's surface comparable in volume to the North American Great Lakes. The detection of shallow subsurface "lakes" implies that the ice shell is recycling rapidly and that Europa may be currently active. In this presentation, we will explore environments on Europa and their analogs on Earth, from collapsing Antarctic ice shelves to to subglacial volcanos in Iceland. I will present these new analyses, and describe how this new perspective informs the debate about Europa's habitability and future exploration.

  18. Stretched proton-neutron configurations in fp-shell nuclei (II). Systematics

    NASA Astrophysics Data System (ADS)

    von Neumann-Cosel, P.; Fister, U.; Jahn, R.; Schenk, P.; Trelle, T. K.; Wenzel, D.; Wienands, U.

    1994-03-01

    The systematics of the binding energies of stretched proton-neutron configurations ( f{7}/{2}, g{9}/{2}) 8 -, ( p{3}/{2}, g{9}/{2}) 6 -, ( g{9}/{2}, p{3}/{2}) 6- and ( g{9}/{2}) 29 + are studied over a wide range of f p-shell nuclei. The effective proton-neutron interaction energies deduced from the data are nearly constant for ( p{3}/{2}, g{9}/{2}) 6 -and ( g{9}/{2}) 29 + states while the ( f{7}/{2}, g{9}/{2}) 8 - configuration reveals an additional repulsive term proportional to the partial filling of the f{7}/{2} orbit in the target ground state. Two-body matrix elements are extracted. A crude shell model, which predicts that the excitation energy of a stretched state is equal to the sum of the single-particle energies, works well for the 6 - and 9 + states, but fails for the 8 - levels due to neglect of the additional interactions described above. The physics underlying the empirically introduced basic assumptions of the crude shell model is discussed. The binding energies are found to be linearly dependent on the mass number A and the isospin Tz component and are well described by the weak-coupling model of Bansal and French. The derived parameters agree with averaged values of a similar analysis for the single-particle states in the corresponding odd-even neighbours. The data indicate a significant change of the particle-hole energies with closure of the proton f{7}/{2} shell.

  19. Lead poisoning: The invisible disease

    USGS Publications Warehouse

    Friend, Milton

    1989-01-01

    Lead poisoning is an intoxication resulting from absorption of hazardous levels of lead into body tissues. Lead pellets from shot shells, when ingested, are the most common source of lead poisoning in migratory birds. Other far less common sources include lead fishing sinkers, mine wastes, paint pigments, bullets, and other lead objects that are swallowed.

  20. Body burdens of heavy metals in Lake Michigan wetland turtles.

    PubMed

    Smith, Dayna L; Cooper, Matthew J; Kosiara, Jessica M; Lamberti, Gary A

    2016-02-01

    Tissue heavy metal concentrations in painted (Chrysemys picta) and snapping (Chelydra serpentina) turtles from Lake Michigan coastal wetlands were analyzed to determine (1) whether turtles accumulated heavy metals, (2) if tissue metal concentrations were related to environmental metal concentrations, and (3) the potential for non-lethal sampling techniques to be used for monitoring heavy metal body burdens in freshwater turtles. Muscle, liver, shell, and claw samples were collected from painted and snapping turtles and analyzed for cadmium, chromium, copper, iron, lead, magnesium, manganese, and zinc. Turtle tissues had measurable quantities of all eight metals analyzed. Statistically significant correlations between tissue metal concentrations and sediment metal concentrations were found for a subset of metals. Metals were generally found in higher concentrations in the larger snapping turtles than in painted turtles. In addition, non-lethal samples of shell and claw were found to be possible alternatives to lethal liver and muscle samples for some metals. Human consumption of snapping turtles presents potential health risks if turtles are harvested from contaminated areas. Overall, our results suggest that turtles could be a valuable component of contaminant monitoring programs for wetland ecosystems.

  1. Oviposition behaviour of the soil mite Pergamasus brevicornis (Acari: Parasitidae).

    PubMed

    Marquardt, Tomasz; Faleńczyk-Koziróg, Katarzyna; Kaczmarek, Sławomir

    2013-07-01

    We observed the oviposition behaviour of the soil mite Pergamasus brevicornis Berlese (Acari: Parasitidae) using continuous video-monitoring. Oviposition consisted of six sequential phases. The first phase (I) involved inspection of the substrate. In the second phase (II) there were rhythmic movements of the first pair of legs and slight reciprocating movements of the body. The third (III) was a resting phase. In the fourth phase (IV) the gnathosoma was lowered and the body was raised. In the next phase (V) there were two sub-phases. During the first (Va), the female held the egg below the gnathosoma. In the second sub-phase (Vb), the gnathosoma moved up holding the egg, which was then placed on the substrate. The last phase (VI) involved intense 'cleaning' movements of the chelicerae and palps. During Va a protective external eggshell structure is gradually formed, involving a phase where the egg shell is sticky. After moving the egg to the substrate, the female freed her palps and chelicerae from the sticky egg shell and cleaned her gnathosomal appendages. Phases II-V took on average 207 ± 69 s.

  2. Aflatoxin and sterigmatocystin contamination of pistachio nuts in orchards.

    PubMed Central

    Sommer, N F; Buchanan, J R; Fortlage, R J

    1976-01-01

    Aspergillus flavus and A. versicolor were both shown to be weak pathogens of developing pistachio fruits, producing aflatoxin and sterigmatocystin, respectively. Aflatoxin concentrations approached those reported in cereal and legume seeds. Fungus lesions on the first hulls were followed by invasion of seeds despite the sclerified shell. Infections and mycotoxins present before harvest would presumably lead to further build-up after harvest if drying was slow or storage was under high humidity. PMID:823868

  3. Science, Technical Innovation and Applications in Bioacoustics: Summary of a Workshop

    DTIC Science & Technology

    2004-07-01

    binaural processing have been neglected. From a signal-processing standpoint, we should avoid complex computational methods and instead use massively...design and/or build transducers or arrays with anywhere near the performance and, most importantly, environmental adaptability of animal binaural ...shell Small animal imaging Cardiac Imaging in Mice The Challenge Mouse heart • 7mm diameter • 8 beats /sec Mouse Heart L16-28MHzL5-10MHz Laptop

  4. The Shock and Vibration Digest. Volume 18, Number 5

    DTIC Science & Technology

    1986-05-01

    response. 16-1067 Seismic Analysis of Azisym metric Shells R.J. Jospin, E.M. Toledo, R.A. Feijoo Laboratorio de Computacao Cientifica, Rio de ...matrices for tapered beam elements, de - rived by various autbots are reviewed. Tapered member framing has been utilized in a variety of building frames of...sectional shape. Dynamic stiffness and consistent mass matrices [2,22] have been de - rived in explicit form for the beam element of closed box of

  5. Nature’s Palette: Characterization of Shared Pigments in Colorful Avian and Mollusk Shells

    PubMed Central

    Brennan, Patricia L. R.; Hanley, Daniel; Grim, Tomáš; Hauber, Mark E.; Holford, Mandë

    2015-01-01

    Pigment-based coloration is a common trait found in a variety of organisms across the tree of life. For example, calcareous avian eggs are natural structures that vary greatly in color, yet just a handful of tetrapyrrole pigment compounds are responsible for generating this myriad of colors. To fully understand the diversity and constraints shaping nature’s palette, it is imperative to characterize the similarities and differences in the types of compounds involved in color production across diverse lineages. Pigment composition was investigated in eggshells of eleven paleognath bird taxa, covering several extinct and extant lineages, and shells of four extant species of mollusks. Birds and mollusks are two distantly related, calcareous shell-building groups, thus characterization of pigments in their calcareous structures would provide insights to whether similar compounds are found in different phyla (Chordata and Mollusca). An ethylenediaminetetraacetic acid (EDTA) extraction protocol was used to analyze the presence and concentration of biliverdin and protoporphyrin, two known and ubiquitous tetrapyrrole avian eggshell pigments, in all avian and molluscan samples. Biliverdin was solely detected in birds, including the colorful eggshells of four tinamou species. In contrast, protoporphyrin was detected in both the eggshells of several avian species and in the shells of all mollusks. These findings support previous hypotheses about the ubiquitous deposition of tetrapyrroles in the eggshells of various bird lineages and provide evidence for its presence also across distantly related animal taxa. PMID:26650398

  6. Bathymetric patterns of body size: implications for deep-sea biodiversity

    NASA Astrophysics Data System (ADS)

    Rex, Michael A.; Etter, Ron J.

    1998-01-01

    The evolution of body size is a problem of fundamental interest, and one that has an important bearing on community structure and conservation of biodiversity. The most obvious and pervasive characteristic of the deep-sea benthos is the small size of most species. The numerous attempts to document and explain geographic patterns of body size in the deep-sea benthos have focused on variation among species or whole faunal components, and have led to conflicting and contradictory results. It is important to recognize that studying size as an adaptation to the deep-sea environment should include analyses within species using measures of size that are standardized to common growth stages. An analysis within eight species of deep-sea benthic gastropods presented here reveals a clear trend for size to increase with depth in both larval and adult shells. An ANCOVA with multiple comparison tests showed that, in general, size-depth relationships for both adult and larval shells are more pronounced in the bathyal region than in the abyss. This result reinforces the notion that steepness of the bathymetric selective gradient decreases with depth, and that the bathyal region is an evolutionary hotspot that promotes diversification. Bathymetric size clines in gastropods support neither the predictions of optimality models nor earlier arguments based on tradeoffs among scaling factors. As in other environments, body size is inversely related to both abundance and species density. We suggest that the decrease in nutrient input with depth may select for larger size because of its metabolic or competitive advantages, and that larger size plays a role in limiting diversity. Adaptation is an important evolutionary driving force of biological diversity, and geographic patterns of body size could help unify ecological and historical theories of deep-sea biodiversity.

  7. Association of myostatin variants with growth traits of Zhikong scallop ( Chlamys farreri)

    NASA Astrophysics Data System (ADS)

    Fu, Qiang; Guo, Huihui; Feng, Liying; Li, Xue; Zhang, Lingling; Wang, Shi; Hu, Xiaoli; Bao, Zhenmin

    2016-02-01

    Scallop is a popular sea food and an important aquaculture shellfish. Identification of genes and genetic variants relating to scallop growth could benefit high-yielding scallop breeding. Myostatin ( MSTN) is a conservative regulator of muscle growth, and has become one of the most important target genes for genetic improvement of the production of farmed animals. In this study, four single nucleotide polymorphisms (SNPs) were identified in the 5' flanking region of MSTN gene ( CfMSTN) in Zhikong scallop ( Chlamys farreri). The association of these SNPs with scallop growth traits, including shell length, shell height, body weight and striated muscle weight was analyzed. The SNP g-1162G

  8. A Preliminary Study on the Pattern, the Physiological Bases and the Molecular Mechanism of the Adductor Muscle Scar Pigmentation in Pacific Oyster Crassostrea gigas

    PubMed Central

    Yu, Wenchao; He, Cheng; Cai, Zhongqiang; Xu, Fei; Wei, Lei; Chen, Jun; Jiang, Qiuyun; Wei, Na; Li, Zhuang; Guo, Wen; Wang, Xiaotong

    2017-01-01

    The melanin pigmentation of the adductor muscle scar and the outer surface of the shell are among attractive features and their pigmentation patterns and mechanism still remains unknown in the Pacific oyster Crassostrea gigas. To study these pigmentation patterns, the colors of the adductor muscle scar vs. the outer surface of the shell on the same side were compared. No relevance was found between the colors of the adductor muscle scars and the corresponding outer surface of the shells, suggesting that their pigmentation processes were independent. Interestingly, a relationship between the color of the adductor muscle scars and the dried soft-body weight of Pacific oysters was found, which could be explained by the high hydroxyl free radical scavenging capacity of the muscle attached to the black adductor muscle scar. After the transcriptomes of pigmented and unpigmented adductor muscles and mantles were studied by RNAseq and compared, it was found that the retinol metabolism pathway were likely to be involved in melanin deposition on the adductor muscle scar and the outer surface of the shell, and that the different members of the tyrosinase or Cytochrome P450 gene families could play a role in the independent pigmentation of different organs. PMID:28955252

  9. Proposed Ames M2-F1, M1-L half-cone, and Langley lenticular bodies.

    NASA Technical Reports Server (NTRS)

    1962-01-01

    Dale Reed, who inaugurated the lifting-body flight research at NASA's Flight Research Center (later, Dryden Flight Research Center, Edwards, CA), originally proposed that three wooden outer shells be built. These would then be attached to the single internal steel structure. The three shapes were (viewer's left to right) the M2-F1, the M1-L, and a lenticular shape. Milt Thompson, who supported Reed's advocacy for a lifting-body research project, recommended that only the M2-F1 shell be built, believing that the M1-L shape was 'too radical,' while the lenticular one was 'too exotic.' Although the lenticular shape was often likened to that of a flying saucer, Reed's wife Donna called it the 'powder puff.' The wingless, lifting body aircraft design was initially conceived as a means of landing an aircraft horizontally after atmospheric reentry. The absence of wings would make the extreme heat of re-entry less damaging to the vehicle. In 1962, Dryden management approved a program to build a lightweight, unpowered lifting body as a prototype to flight test the wingless concept. It would look like a 'flying bathtub,' and was designated the M2-F1, the 'M' referring to 'manned' and 'F' referring to 'flight' version. It featured a plywood shell placed over a tubular steel frame crafted at Dryden. Construction was completed in 1963. The first flight tests of the M2-F1 were over Rogers Dry Lake at the end of a tow rope attached to a hopped-up Pontiac convertible driven at speeds up to about 120 mph. This vehicle needed to be able to tow the M2-F1 on the Rogers Dry Lakebed adjacent to NASA's Flight Research Center (FRC) at a minimum speed of 100 miles per hour. To do that, it had to handle the 400-pound pull of the M2-F1. Walter 'Whitey' Whiteside, who was a retired Air Force maintenance officer working in the FRC's Flight Operations Division, was a dirt-bike rider and hot-rodder. Together with Boyden 'Bud' Bearce in the Procurement and Supply Branch of the FRC, Whitey acquired a Pontiac Catalina convertible with the largest engine available. He took the car to Bill Straup's renowned hot-rod shop near Long Beach for modification. With a special gearbox and racing slicks, the Pontiac could tow the 1,000-pound M2-F1 110 miles per hour in 30 seconds. It proved adequate for the roughly 400 car tows that got the M2-F1 airborne to prove it could fly safely and to train pilots before they were towed behind a C-47 aircraft and released. These initial car-tow tests produced enough flight data about the M2-F1 to proceed with flights behind the C-47 tow plane at greater altitudes. The C-47 took the craft to an altitude of 12,000 where free flights back to Rogers Dry Lake began. Pilot for the first series of flights of the M2-F1 was NASA research pilot Milt Thompson. Typical glide flights with the M2-F1 lasted about two minutes and reached speeds of 110 to l20 mph. A small solid landing rocket, referred to as the 'instant L/D rocket,' was installed in the rear base of the M2-F1. This rocket, which could be ignited by the pilot, provided about 250 pounds of thrust for about 10 seconds. The rocket could be used to extend the flight time near landing if needed. More than 400 ground tows and 77 aircraft tow flights were carried out with the M2-F1. The success of Dryden's M2-F1 program led to NASA's development and construction of two heavyweight lifting bodies based on studies at NASA's Ames and Langley research centers--the M2-F2 and the HL-10, both built by the Northrop Corporation, and the U.S. Air Force's X-24 program, with an X-24A and -B built by Martin. The Lifting Body program also heavily influenced the Space Shuttle program. The M2-F1 program demonstrated the feasibility of the lifting body concept for horizontal landings of atmospheric entry vehicles. It also demonstrated a procurement and management concept for prototype flight test vehicles that produced rapid results at very low cost (approximately $50,000, excluding salaries of government employees assigned to the project).

  10. Modeling Tidal Stresses on Planetary Bodies Using an Enhanced SatStress GUI

    NASA Astrophysics Data System (ADS)

    Patthoff, D. A.; Pappalardo, R. T.; Tang, L.; Kay, J.; Kattenhorn, S. A.

    2014-12-01

    Icy and rocky satellites of our solar system display a wide range of structural deformation on their surfaces. Some surfaces are old and heavily cratered showing little evidence for recent tectonism while other surfaces are sparsely cratered and young, with some moons showing geologically very recent or present-day activity. The young deformation can take the form of small cracks in the surface, large double ridges that can extend for thousands of km, and mountain ranges that can reach heights of several kilometers. Many of the potential sources of stress that can deform the surfaces are likely tied to the diurnal tidal deformation of the moons as they orbit their parent planets. Other secular sources of global-scale stress include: volume change induced by the melting or freezing of a subsurface liquid layer, change in the orbital parameters of the moon, or rotation of the outer shell of the satellite relative to the rest of the body (nonsynchronous rotation or true polar wander). We turn to computer modeling to correlate observed structural features to the possible stresses that created them. A variety of modeling programs exist and generally assume a thin ice shell and/or a multi-layered viscoelastic satellite. The program SatStress, which was developed by Zane Crawford and documented by Wahr et al. (2009), computes tidal and nonsynchronous rotation stresses on a satellite. It was later modified into a more user-friendly version with a graphical user interface (SatStress GUI) by Kay and Kattenhorn (2010). This implementation assumes a 4-layer viscoelastic body and is able to calculate stresses resulting from diurnal tides, nonsynchronous rotation, and ice shell thickening. Here we illustrate our recent enhancements to SatStress GUI and compare modeled stresses to example features observed on the surfaces of Ganymede, Europa, and Enceladus. Kay and Kattenhorn (2010) 41st LPSC, abs # 2046. Wahr et al. (2009) Icarus, 200, 188-206.

  11. O (6 ) algebraic theory of three nonrelativistic quarks bound by spin-independent interactions

    NASA Astrophysics Data System (ADS)

    Dmitrašinović, V.; Salom, Igor

    2018-05-01

    We apply the newly developed theory of permutation-symmetric O (6 ) hyperspherical harmonics to the quantum-mechanical problem of three nonrelativistic quarks confined by a spin-independent three-quark potential. We use our previously derived results to reduce the three-body Schrödinger equation to a set of coupled ordinary differential equations in the hyper-radius R with coupling coefficients expressed entirely in terms of (i) a few interaction-dependent O (6 ) expansion coefficients and (ii) O (6 ) hyperspherical harmonics matrix elements that have been evaluated in our previous paper. This system of equations allows a solution to the eigenvalue problem with homogeneous three-quark potentials, the class of which includes a number of standard Ansätze for the confining potentials, such as the Y- and Δ -string ones. We present analytic formulas for the K =2 , 3, 4, 5 shell states' eigenenergies in homogeneous three-body potentials, which we then apply to the Y and Δ strings as well as the logarithmic confining potentials. We also present numerical results for power-law pairwise potentials with the exponent ranging between -1 and +2 . In the process, we resolve the 25-year-old Taxil and Richard vs Bowler et al. controversy regarding the ordering of states in the K =3 shell, in favor of the former. Finally, we show the first clear difference between the spectra of Δ - and Y-string potentials, which appears in K ≥3 shells. Our results are generally valid, not just for confining potentials but also for many momentum-independent permutation-symmetric homogenous potentials that need not be pairwise sums of two-body terms. The potentials that can be treated in this way must be square integrable under the O (6 ) hyperangular integral, the class of which, however, does not include the Dirac δ function.

  12. Rapid Return of Nitrogen but not Phosphorus to Ecosystem Nutrition During Decomposition of Quagga Mussel Tissue in Sand, Mud, or Water During Oxic or Anoxic Incubation: Implications for Phytoplankton Bioenergetics.

    NASA Astrophysics Data System (ADS)

    Cooney, E. M.; Cuhel, R. L.; Aguilar, C.

    2016-02-01

    In 2003 Quagga mussels were found to have invaded Lake Michigan. Their presence has changed the structure of the lake both ecologically (benthification) as well as chemically (oligotrophication). They consume large amounts of phytoplankton, which decreases the particulate nitrogen and phosphorous nutrients available to other consumers including zooplankton. As a result, fisheries productivity has decreased nearly 95%. Recently reaching the end of the first life cycle, in death they release a portion of these nutrients back into the freshwater system during decomposition. This work determined amounts of phosphorus and nitrogen nutrient recycling for several relevant sediment-water interface conditions: oxic vs anoxic in water, mud, or sand over a weeklong period. Concentrations of ammonium, soluble reactive phosphorus, and nitrate were used to analyze nutrient release as decomposition took place. In a short time up to 25% of tissue N was released as ammonia, and under oxic conditions in mud or sand, nitrification converted some of the ammonia to nitrate. Unexpectedly, mussels decaying in anoxic conditions released ammonium much more slowly. A slower rate of release in ammonium for the intact body with the shell (burial) was observed when compared to ground mussel tissue (detritivory). Nitrate was removed in anoxic incubations, indicating anaerobic denitrification. Phosphate release was initially higher under anoxic conditions than those decaying aerobically. There was no significant difference in the amount or rate of release of SRP between ground mussel and whole bodied with the shell. The anoxic treatment showed similar patterns of release for both ground mussel and intact body with shell. Most important, phosphate was subsequently removed in all treatments and diffusible nutrient was minimal (<100nM). The results link to nutrient assimilation patterns of deep phytoplankton communities, which can replace nitrate with ammonium as an N source.

  13. Electroformation of Janus and patchy capsules

    NASA Astrophysics Data System (ADS)

    Rozynek, Zbigniew; Mikkelsen, Alexander; Dommersnes, Paul; Fossum, Jon Otto

    2014-05-01

    Janus and patchy particles have designed heterogeneous surfaces that consist of two or several patches with different materials properties. These particles are emerging as building blocks for a new class of soft matter and functional materials. Here we introduce a route for forming heterogeneous capsules by producing highly ordered jammed colloidal shells of various shapes with domains of controlled size and composition. These structures combine the functionalities offered by Janus or patchy particles, and those given by permeable shells such as colloidosomes. The simple assembly route involves the synergetic action of electro-hydrodynamic flow and electro-coalescence. We demonstrate that the method is robust and straightforwardly extendable to production of multi-patchy capsules. This forms a starting point for producing patchy colloidosomes with domains of anisotropic chemical surface properties, permeability or mixed liquid-solid phase domains, which could be exploited to produce functional emulsions, light and hollow supra-colloidosome structures, or scaffolds.

  14. Nuclear component horizontal seismic restraint

    DOEpatents

    Snyder, Glenn J.

    1988-01-01

    A nuclear component horizontal seismic restraint. Small gaps limit horizontal displacement of components during a seismic occurrence and therefore reduce dynamic loadings on the free lower end. The reactor vessel and reactor guard vessel use thicker section roll-forged rings welded between the vessel straight shell sections and the bottom hemispherical head sections. The inside of the reactor guard vessel ring forging contains local vertical dovetail slots and upper ledge pockets to mount and retain field fitted and installed blocks. As an option, the horizontal displacement of the reactor vessel core support cone can be limited by including shop fitted/installed local blocks in opposing alignment with the reactor vessel forged ring. Beams embedded in the wall of the reactor building protrude into apertures in the thermal insulation shell adjacent the reactor guard vessel ring and have motion limit blocks attached thereto to provide to a predetermined clearance between the blocks and reactor guard vessel ring.

  15. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Friedman-Hill, Ernest

    Java Expert Shell System - Jess - is a rule engine and scripting environment written entirely in Sun's Java language, Jess was orginially inspired by the CLIPS expert system shell, but has grown int a complete, distinct JAVA-influenced environment of its own. Using Jess, you can build Java applets and applications that have the capacity to "reason" using knowledge you supply in the form of declarative rules. Jess is surprisingly fast, and for some problems is faster than CLIPS, in that many Jess scripts are valid CLIPS scripts and vice-versa. Like CLIPS, Jess uses the Rete algorithm to process rules,more » a very efficient mechanism for solving the difficult many-to-many matching problem. Jess adds many features to CLIPS, including backwards chaining and the ability to manipulate and directly reason about Java objects. Jess is also a powerful Java scripting environment, from which you can create Java objects and call Java methods without compiling any Java Code.« less

  16. Intelligent tutoring using HyperCLIPS

    NASA Technical Reports Server (NTRS)

    Hill, Randall W., Jr.; Pickering, Brad

    1990-01-01

    HyperCard is a popular hypertext-like system used for building user interfaces to databases and other applications, and CLIPS is a highly portable government-owned expert system shell. We developed HyperCLIPS in order to fill a gap in the U.S. Army's computer-based instruction tool set; it was conceived as a development environment for building adaptive practical exercises for subject-matter problem-solving, though it is not limited to this approach to tutoring. Once HyperCLIPS was developed, we set out to implement a practical exercise prototype using HyperCLIPS in order to demonstrate the following concepts: learning can be facilitated by doing; student performance evaluation can be done in real-time; and the problems in a practical exercise can be adapted to the individual student's knowledge.

  17. Plasmon Mapping in Au@Ag Nanocube Assemblies

    PubMed Central

    2014-01-01

    Surface plasmon modes in metallic nanostructures largely determine their optoelectronic properties. Such plasmon modes can be manipulated by changing the morphology of the nanoparticles or by bringing plasmonic nanoparticle building blocks close to each other within organized assemblies. We report the EELS mapping of such plasmon modes in pure Ag nanocubes, Au@Ag core–shell nanocubes, and arrays of Au@Ag nanocubes. We show that these arrays enable the creation of interesting plasmonic structures starting from elementary building blocks. Special attention will be dedicated to the plasmon modes in a triangular array formed by three nanocubes. Because of hybridization, a combination of such nanotriangles is shown to provide an antenna effect, resulting in strong electrical field enhancement at the narrow gap between the nanotriangles. PMID:25067991

  18. PML nuclear bodies: from architecture to function.

    PubMed

    Lallemand-Breitenbach, Valérie; de Thé, Hugues

    2018-06-01

    PML nuclear bodies are nucleated by the PML protein, which polymerizes into spherical shells where it concentrates many unrelated partner proteins. Emerging data has connected PML bodies to post-translational control, notably conjugation by SUMOs. High concentrations of SUMO-bound proteins were proposed to condense into liquid-like droplets and such phase transition may occur within NBs. Many stress pathways modulate NB formation and recent findings have directly implicated PML in oxidative stress response in vivo. PML may also undergo SUMO-dependent ubiquitination/degradation. We highlight recent advances linking PML to partner degradation and other adaptative post-translational modifications in the context of chromatin remodeling, telomere biology, senescence or viral infections. Copyright © 2018. Published by Elsevier Ltd.

  19. A mini review on the integration of resource recovery from wastewater into sustainability of the green building through phycoremediation

    NASA Astrophysics Data System (ADS)

    Yulistyorini, Anie

    2017-09-01

    Green building implementation is an important assessment for sustainable development to establish a good quality of the environment. To develop the future green building implementation, resource recovery from the building wastewater is significantly important to consider as a part of the green building development. Discharge of urban wastewater into water bodies trigger of eutrophication in the water catchment, accordingly need further treatment to recover the nutrient before it is reused or discharged into receiving water bodies. In this regard, integration of microalgae cultivation in closed photobioreactor as building façade is critically important to be considered in the implementation of the green building. Microalgae offer multi-function as bioremediation (phycoremediation) of the wastewater, production of the biofuels, and important algal bio-products. At the same time, algae façade boost the reduction of the operating cost in forms of light, thermal energy and add the benefit into the building for energy reduction and architecture function. It promises an environmental benefit to support green building spirit through nutrient recovery and wastewater reuse for algae cultivation and to enhance the aesthetic of the building façade.

  20. Intermediate energy proton-deuteron elastic scattering

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.

    1973-01-01

    A fully symmetrized multiple scattering series is considered for the description of proton-deuteron elastic scattering. An off-shell continuation of the experimentally known twobody amplitudes that retains the exchange symmeteries required for the calculation is presented. The one boson exchange terms of the two body amplitudes are evaluated exactly in this off-shell prescription. The first two terms of the multiple scattering series are calculated explicitly whereas multiple scattering effects are obtained as minimum variance estimates from the 146-MeV data of Postma and Wilson. The multiple scattering corrections indeed consist of low order partial waves as suggested by Sloan based on model studies with separable interactions. The Hamada-Johnston wave function is shown consistent with the data for internucleon distances greater than about 0.84 fm.

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