WorldWideScience

Sample records for wind-made ice sculpture

  1. Ice sculpture in the Martian outflow channels

    Science.gov (United States)

    Lucchitta, B. K.

    1982-01-01

    Viking Orbiter and terrestrial satellite images are examined at similar resolution to compare features of the Martian outflow channels with features produced by the movement of ice on earth, and many resemblances are found. These include the anastomoses, sinuosities, and U-shaped cross profiles of valleys; hanging valleys; linear scour marks on valley walls; grooves and ridges on valley floors; and the streamlining of bedrock highs. Attention is given to the question whether ice could have moved in the Martian environment. It is envisaged that springs or small catastrophic outbursts discharged fluids from structural outlets or chaotic terrains. These fluids built icings that may have grown into substantial masses and eventually flowed like glaciers down preexisting valleys. An alternative is that the fluids formed rivers or floods that in turn formed ice jams and consolidated into icy masses in places where obstacles blocked their flow.

  2. Kinetic sculpture

    OpenAIRE

    Joneta Witabora; Jonata Witabora

    2014-01-01

    Kinetic Sculpture was born from a long process of searching new approach in sculpture. The artists tried to escape from 'static' paradigm and tried to implement movement into their works: a sculpture that is mobile. Movement is always a fascinating phenomenon to eyes. Kinetic sculpture strength lies in its unique character in combining science and art. Kinetic Sculptures are really interesting pieces of art. It succeeds to fascinate human everytime. 

  3. Relief Sculpture

    Science.gov (United States)

    Lawrence, Trudy

    2005-01-01

    Relief sculpture is an art form that is midway between painting and sculpture in the round. It is a process in which the subject stands out or projects a surface from the background. The surface has several levels. It can be low relief or high relief (deep or almost round) or anywhere in between. The most common example of low relief is a coin…

  4. Telling Stories through Sculpture.

    Science.gov (United States)

    Greenman, Geri

    2000-01-01

    Describes an art activity that incorporates storytelling with sculpture. Intermediate-level sculpture students create a sculpture that represents a family story, memory, or event. Describes the process and provides four examples, including stories and sculptures. (CMK)

  5. Digital Sculpture Installations

    Science.gov (United States)

    Sherwood, Catherine

    2006-01-01

    This author relates how she came upon the idea of using an image-editing program to virtually install monumental sculptures into real-life landscapes in her desire to bring technology and sculpture together in her art class. In this article, she describes how she made her class create tabletop-sized sculptures and photographs of digital…

  6. Self-Portrait Sculpture.

    Science.gov (United States)

    Gorberg, Sharon

    2002-01-01

    Describes a project where eighth-grade girls create self-portrait sculptures made out of papier-mache and other materials. Explains that the sculptures serve as an outlet for the students to express something about their own personal identities. Discusses in detail the process of creating the sculptures. (CMK)

  7. Structures in sculptures

    DEFF Research Database (Denmark)

    Vanggaard, Ole

    the different concepts and find a final synthesis, but the problem is known. Large sculptures represent structural challenges. The design of the supports inside the structures reveals often a very different world from the outside view of the sculpture. The piece of art and its structure may have two very...... different lives. A sculpture of today may be very dissimilar from what we have seen earlier. The structure becomes sometimes a visual part of the art. Ultimately, there may not be any distinction between structure and art. The technical demand, the durability and the safety are just as important for a large...... sculpture as in all other structures. The problem presented by the artist involves sometimes quite new structural themes. The dialog between the engineer and the artist brings the engineer close into the creative work of the artist. Neither the artist nor the engineer can rely upon any tradition...

  8. Sculpture Sketches in Bloom

    Science.gov (United States)

    DiJulio, Betsy

    2009-01-01

    The best artistic challenges open students' eyes, hearts, and minds by combining both formal and conceptual concerns. In this article, the author describes a project inspired by a temporary exhibition of African Shona sculpture entitled "Mutambo! (Celebrate!)" at the Norfolk Botanical Gardens in Norfolk, Virginia. (Contains 2 online…

  9. Wood Sculpture Characters

    Science.gov (United States)

    Hubbert, Beth

    2006-01-01

    Whenever possible, the author tries to incorporate the work of artists who are included in the collection of nearby museums. The school is close to the Dallas area and visiting the Dallas Museum of Arts (DMA) is in the realm possibility. The DMA has a sculpture in their collection by artist David Bates called "Seated Man #4." The fact…

  10. Sculpture Versus Architecture?

    Directory of Open Access Journals (Sweden)

    Alexander Rappaport

    2007-07-01

    Full Text Available Many critics consider Richard Serra the leading sculptor of the 20th century. He is famous not only for inventing something new in sculpture (abstract sculpture compositions existed before him, having been opened by constructivist vanguard of the beginning of the 20th century. Material selections by Vladimir Tatlin and sculptures by Osip Tsadkin, as well as compositions by Henry Moor appeared before Serra. Serra is famous for transferring his works' accent from the works as they are, which could be installed in any place, to their environment. That is he saw in the sculpture a key to understanding the urban space. His crude metal sheets and profiles, rectangular and curvilinear, exceeding regular scale of sculpture, come closer to architecture. Richard Serra places them near architectural constructions as checkpoints of intermediate scale category of space located between so-called «street furniture» – lamp posts, stalls, fountains and benches – and buildings, especially huge modern ones.But the matter is not only in the scale. Serra's sculptures are not only abstract compositions that harmoniously add to the space with their spacious scale. They have some mystery, some implicit sense appearing before a pedestrian as an enigma. Their mystique opposes both street furniture and architecture. But first of all it opposes the historical sculpture with its enigma always overshadowed by historical or biographical topic. Krylov's sculpture in the Summer Garden or Minin and Pozharsky's monument on the Red Square do not strike us, because we know that those monuments are erected IN COMMEMORATION of prominent people, as fellow citizens' tribute to their great contribution to the national history. But the crude metal sheets welded at different angles – what are they for? Who needs them?As an art critic, Edward Goldman, said, fame came to Richard Serra in 1989, when the sculpture composition Tilted Arc erected eight years before it was demolished by

  11. Chihuly-Inspired Balloon Sculptures

    Science.gov (United States)

    Morice, Erin

    2009-01-01

    When the glass artist Dale Chihuly exhibited his work at the Missouri Botanical Garden, the author took a class of fourth-grade students to view the artist's extraordinary sculptures. Just as the author predicted, the students were in awe of Chihuly's organic three-dimensional sculptures. Before taking the field trip to the Missouri Botanical…

  12. Sculpturing Surfaces with Cartan Ribbons

    DEFF Research Database (Denmark)

    Raffaelli, Matteo; Bohr, Jakob; Markvorsen, Steen

    2016-01-01

    Using the concepts of Cartan development and rolling from differential geometry we develop a method for sculpturing any surface with the use of Cartan ribbons.......Using the concepts of Cartan development and rolling from differential geometry we develop a method for sculpturing any surface with the use of Cartan ribbons....

  13. Machining of Complex Sculptured Surfaces

    CERN Document Server

    2012-01-01

    The machining of complex sculptured surfaces is a global technological topic in modern manufacturing with relevance in both industrialized and emerging in countries particularly within the moulds and dies sector whose applications include highly technological industries such as the automotive and aircraft industry. Machining of Complex Sculptured Surfaces considers new approaches to the manufacture of moulds and dies within these industries. The traditional technology employed in the manufacture of moulds and dies combined conventional milling and electro-discharge machining (EDM) but this has been replaced with  high-speed milling (HSM) which has been applied in roughing, semi-finishing and finishing of moulds and dies with great success. Machining of Complex Sculptured Surfaces provides recent information on machining of complex sculptured surfaces including modern CAM systems and process planning for three and five axis machining as well as explanations of the advantages of HSM over traditional methods ra...

  14. Sanguibacter gelidistatuariae sp. nov., a novel psychrotolerant anaerobe from an ice sculpture in Antarctica, and emendation of descriptions of the family Sanguibacteraceae, the genus Sanguibacter and species S. antarcticus, S. inulinus, S. kedieii, S. marinus, S. soli and S. suarezii.

    Science.gov (United States)

    Pikuta, Elena V; Lyu, Zhe; Williams, Melissa D; Patel, Nisha B; Liu, Yuchen; Hoover, Richard B; Busse, Hans-Jürgen; Lawson, Paul A; Whitman, William B

    2017-05-01

    A novel psychrotolerant bacterium, strain ISLP-3T, was isolated from a sample of naturally formed ice sculpture on the shore of Lake Podprudnoye in Antarctica. Cells were motile, stained Gram-positive, non-spore-forming, straight or slightly curved rods with the shape of a baseball bat. The new isolate was facultatively anaerobic and catalase-positive. Growth occurred at 3-35 °C with an optimum at 22-24 °C, 0-2 % (w/v) NaCl with an optimum at 0.3 % and pH 6.2-9.5 with an optimum at pH 7.5. Strain ISLP-3T grew on several carbon sources, with the best growth on cellobiose. The isolate possessed ureolytic activity but growth was inhibited by urea. The strain was sensitive to: ampicillin, gentamycin, kanamycin rifampicin, tetracycline and chloramphenicol. Major fatty acids were: anteiso-C15 : 0, iso-C16 : 0, C16 : 0, C14 : 0 and iso-C15 : 0. The predominant menaquinone was MK-9(H4). The genomic G+C content was 69.5 mol%. The 16S rRNA gene showed 99 % sequence similarity to that of Sanguibacter suarezii ST-26T, but their recA genes shared ≤91 % sequence similarity, suggesting that this new isolate represents a novel species within the genus Sanguibacter. This conclusion was supported by average nucleotide identity, which was ≤91 % to the most closely related strain. The name Sanguibacter gelidistatuariae sp. nov. is proposed for the novel species with the type strain ISLP-3T=ATCC TSD-17T=DSM 100501T=JCM 30887T). The complete genome draft sequence of ISLP-3T was deposited under IMG OID 2657245272. Emendments to the descriptions of related taxa have been made based on experimental data from our comparative analysis.

  15. African Traditional Sculpture and Aesthetic Realism | Mangiri ...

    African Journals Online (AJOL)

    Traditional African sculpture which is one of the essences of modern art movements in the world of art has not been attributed with that aesthetic identity. However, a close look at the traditional African sculpture reveals the artistic and aesthetic qualities. African traditional sculpture was regarded as mere objects or crafts.

  16. The Sculpture, man and word

    OpenAIRE

    Madjar, Neda

    2016-01-01

    In the diploma work entitled The Sculpture, Man and Word I explore the practices of the modern and the contemporary art. The theoretical part begins with sculpture, wire and iron as materials and with the artists that have been active within this particular field. These artists are Picasso, Gonzalez and Calder in the 1920s and 1930s, and David Smith at the turn of the century. I continue by taking a look at the following practices: readymade, fluxus, performance and conceptual art. These a...

  17. Eurasia International Sculpture Biennale, Kazakhstan

    OpenAIRE

    Heywood, Anthony

    2017-01-01

    The first Eurasia International Sculpture Biennale was held from 4 July to 4 August 2017 in the atrium of the Palace of Peace and Reconciliation as one of the most important events of the cultural program EXPO-2017, commissioned by the Ministry of Culture and Sports of the Republic of Kazakhstan.

  18. Three-Dimensional Utah: 100 Years of Sculpture

    OpenAIRE

    Nora Eccles Harrison Museum of Art

    1996-01-01

    Three-Dimensional Utah: 100 Years of Sculpture began as a series of conversations about sculptors and sculpture nearly six years ago. Specific development of the exhibition began three years ago during the process of creating a national inventory of outdoor sculpture for a program called Save Outdoor Sculpture (SOS)! Utah is home to more than 200 pieces of outdoor sculpture.

  19. The Iberian sculpture from Fabara (Zaragoza

    Directory of Open Access Journals (Sweden)

    Ignacio Simón Cornago

    2017-12-01

    Full Text Available The aim of this paper is to study again the Iberian sculpture from Fabara, because it was catalogued as a lion, while in fact it seems to be a horse. It’s one of few stone sculptures that have been documented in the northern part of the Iberian areas in the Peninsula, because the vast majority of Iberian stone sculptures are found in the South.

  20. Walter Pater and the Language of Sculpture

    DEFF Research Database (Denmark)

    Østermark-Johansen, Lene

    Walter Pater and the Language of Sculpture is the first monograph to discuss the Victorian critic Walter Pater's attitude to sculpture. It brings together Pater's aesthetic theories with his theories on language and writing, to demonstrate how his ideas of the visual and written language...... are closely linked. Going beyond Pater's views on sculpture as an art form, this study traces the notion of relief (rilievo) and hybrid form in Pater, and his view of the writer as sculptor, a carver in language. Alongside her treatment of rilievo as a pervasive trope, Lene Østermark-Johansen also employs...... the idea of rivalry (paragone) more broadly, examining Pater's concern with positioning himself as an art critic in the late Victorian art world. Situating Pater within centuries of European aesthetic theories as never before done, Walter Pater and the Language of Sculpture throws new light...

  1. Ceramics And Sculpture Interface With Architecture.

    OpenAIRE

    Peters Edem E.; Henry Asante

    2015-01-01

    This work is an inter-disciplinary discourse that examines the role that their collective efforts it properly harassed can play in the development of modern architecture to meet the quest for safe and comfortable homes. The paper aims at assessing how much presence there are sculpture and ceramics in architecture. Sculpture and ceramics are disciplines in fine art and industrial art respectively. The paper identifies the specific contributions each discipline gives to the making of modern arc...

  2. Structural aspects of Imbrium sculpture, part G

    Science.gov (United States)

    Scott, D. H.

    1972-01-01

    Apollo 16 metric photographs taken at low to high sun angles provided the first stereographic coverage of the distinctive landforms collectively referred to as Imbrium sculpture. The sculpture consists of a series of nearly linear ridges and troughs extending radially outward for more than 1000 km from the rim of the Imbrium Basin. The origin of the ridges and troughs, whether by deposition and impact scoring by fluidized clouds of ejecta from the Imbrium Basin or by faulting and volcanism during and subsequent to basin formation, is controversial. Evidence indicative of the mode of origin of Imbrium sculpture is summarized as follows. Evidence of volcano-tectonic mode of origin is favored by: (1) wide variation in relative age of parts of the sculpture; (2) furrows without rims; (3) absence of ballistic shielding; (4) asymmetry of sculpture; (5) absence of randomly oriented clusters; and (6) association with other features of structural origin. An origin by ejecta scoring and deposition is favored by the gradational ejecta with a Fra Mauro-type texture. Features that are ambiguous as to mode or origin are furrows made of coalesced crater chains and prominent rims on furrows.

  3. EDXRF analysis of sculptures on polychrome wood

    International Nuclear Information System (INIS)

    Felix, Valter de Souza; Calza, Cristiane; Lopes, Ricardo Tadeu; Freitas, Renato P.

    2015-01-01

    In the last years, the analysis of sacred sculptures, belonging to museums, churches and private collectors has gained an increasing interest. This kind of analysis can be extremely valuable to conservation and restoration treatments; it can also supply important information that makes possible to identify an artist, to date a sculpture and to identify forgeries. By means of techniques such as XRF, PIXE or XRD, is possible to identify the composition of materials employed in the manufacturing of the pieces, pigments used in the polychromy and also the presence of ancient or modern retouchings. However, the fact that every artwork is a unique piece emphasizes the necessity of working with non-destructive techniques. This work reports the analysis of two sacred images on polychrome wood - portraying Our Lady (XIX century) and Saint Anthony (XVIII century) - using EDXRF. The analyses were performed with a portable system, consisting of Amptek 123-SDD detector and Mini-X X-Ray tube, with W anode, operating at 30 kV and 40 μA. The analysis of the sculpture of Our Lady revealed the use of the following pigments: lead white, lithopone, vermilion, red ochre, umber and Prussian blue. The analysis of Saint Anthony revealed: lead white, vermilion, brown ochre, bone black and Prussian blue. In both sculptures the use of gold foils for gilding was proved by the presence of Au in the spectra. These results were used to assist the restoration procedures of the sculptures. (author)

  4. EDXRF analysis of sculptures on polychrome wood

    Energy Technology Data Exchange (ETDEWEB)

    Felix, Valter de Souza; Calza, Cristiane; Lopes, Ricardo Tadeu, E-mail: ccalza@lin.ufrj.br, E-mail: ricardo@lin.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil); Freitas, Renato P., E-mail: renato.freitas@ifrj.edu.br, E-mail: valter.felix@ifrj.edu.br [Instituto Federal do Rio de Janeiro (IFRJ), Paracambi, RJ (Brazil)

    2015-07-01

    In the last years, the analysis of sacred sculptures, belonging to museums, churches and private collectors has gained an increasing interest. This kind of analysis can be extremely valuable to conservation and restoration treatments; it can also supply important information that makes possible to identify an artist, to date a sculpture and to identify forgeries. By means of techniques such as XRF, PIXE or XRD, is possible to identify the composition of materials employed in the manufacturing of the pieces, pigments used in the polychromy and also the presence of ancient or modern retouchings. However, the fact that every artwork is a unique piece emphasizes the necessity of working with non-destructive techniques. This work reports the analysis of two sacred images on polychrome wood - portraying Our Lady (XIX century) and Saint Anthony (XVIII century) - using EDXRF. The analyses were performed with a portable system, consisting of Amptek 123-SDD detector and Mini-X X-Ray tube, with W anode, operating at 30 kV and 40 μA. The analysis of the sculpture of Our Lady revealed the use of the following pigments: lead white, lithopone, vermilion, red ochre, umber and Prussian blue. The analysis of Saint Anthony revealed: lead white, vermilion, brown ochre, bone black and Prussian blue. In both sculptures the use of gold foils for gilding was proved by the presence of Au in the spectra. These results were used to assist the restoration procedures of the sculptures. (author)

  5. Trends in Owo traditional sculpture: 1995-2010 | Aseniserare ...

    African Journals Online (AJOL)

    This study probes into the origin, style and patronage of the traditional sculptures in Owo kingdom between 1950 and 2010. It examines comparatively the sculpture of the people and its affinity with Benin and Ife before and during the period in question with a view to predicting the future of the sculptural arts of the people in ...

  6. Atomic Oxygen Cleaning of Unpainted Plaster Sculptures

    Science.gov (United States)

    Banks, Bruce A.; Miller, Sharon K.

    2017-01-01

    Atomic oxygen erosion of polymers has been found to be a threat to spacecraft in low Earth orbit. As a result ground facilities have been developed to identify coatings to protect polymers such as used for solar array blankets. As a result of extensive laboratory testing, it was discovered that soot and other organic contamination on paintings could be readily removed by atomic oxygen interactions with minimal damage to the artwork. No method, other than dusting, has been found to be effective in the cleaning of unpainted plaster sculptures This presentation discusses the atomic oxygen interaction processes and how effective they are for cleaning soot damaged unpainted plaster sculptures.

  7. Ceramics And Sculpture Interface With Architecture.

    Directory of Open Access Journals (Sweden)

    Peters Edem E.

    2015-08-01

    Full Text Available This work is an inter-disciplinary discourse that examines the role that their collective efforts it properly harassed can play in the development of modern architecture to meet the quest for safe and comfortable homes. The paper aims at assessing how much presence there are sculpture and ceramics in architecture. Sculpture and ceramics are disciplines in fine art and industrial art respectively. The paper identifies the specific contributions each discipline gives to the making of modern architecture and offers suggestions for future improvement that will lead to entrepreneurial skill and its development.

  8. Walter Pater and the Language of Sculpture

    DEFF Research Database (Denmark)

    Østermark-Johansen, Lene

    are closely linked. Going beyond Pater's views on sculpture as an art form, this study traces the notion of relief (rilievo) and hybrid form in Pater, and his view of the writer as sculptor, a carver in language. Alongside her treatment of rilievo as a pervasive trope, Lene Østermark-Johansen also employs...... the idea of rivalry (paragone) more broadly, examining Pater's concern with positioning himself as an art critic in the late Victorian art world. Situating Pater within centuries of European aesthetic theories as never before done, Walter Pater and the Language of Sculpture throws new light...

  9. HINTS IN OMABE BASED SCULPTURE INSTALLATIONS ...

    African Journals Online (AJOL)

    ASOGWA IFEANYI

    2017-02-02

    Feb 2, 2017 ... refractive gaze approach, was developed and used, in realizing the conceptual forms in sculpture ... Introduction. Contemporary trends in art academia tend to be shifting in favour of multiple or collaborative approaches, where cultural perceptions and ..... as part and parcel of him, in his course of action.

  10. Instructional Resources: Issues in Public Sculpture.

    Science.gov (United States)

    Hill, Julie Lasater; And Others

    1988-01-01

    Presents four lesson plans for teaching K-12 students about public sculpture and contemporary sculptors. Highlights the following works: "Playscapes" by Isamu Noguchi, "The Dallas Piece" by Henry Moore, "Old Glory" by Mark di Suvero, and "Face of the Earth" by Vito Acconci. Includes background information on…

  11. The Joy of Creating Virtual Mathematical Sculptures.

    Science.gov (United States)

    Chuan, Jen-chung

    The process of turning symbols into a mathematical sculpture has never been easier. A copy of Maple V release five and a Web browser configured with a VRML plug-in such as the Cosmo Player is necessary to do these activities. Maple V furnishes the computing environment with the capability of allowing for concentration on the mathematical…

  12. Some Call It Stone: Teaching Abstract Sculpture

    Science.gov (United States)

    Asher, Rikki

    2004-01-01

    Abstract visual art is not for everybody. Some people find it threatening, uncomfortable, and often, inaccessible. Understandably, this can result in a lack of attention paid to nonrepresentational works of art in the visual arts curriculum. This article describes an experiential, hands-on, field trip that sought to demystify abstract sculpture,…

  13. Sandscape - engaging people in Met Office science through sand sculpture

    Science.gov (United States)

    Liggins, Felicity; Dowell, Ellen; Wardley, Jamie; Jamieson, Claire

    2017-04-01

    In 2015, the Met Office's award-winning outreach programme, designed to inspire the next generation of scientists and engineers, delivered one of its most ambitious and creative activities to date. It explored how scientists and artists can come together to create an engaging experience for young people and families. This activity was called Sandscape. Sandscape is an interactive sand sculpture workshop exploring how weather and climate affect our health. Budding sand sculptors are shown how to fashion elaborate structures from sand and water - creating a landscape with bridges, skyscrapers, forests and factories. As they work, participants are encouraged by the scientists delivering the activity to reflect on what makes a healthy city, considering how the natural and built environments influence air quality and circulation and how this impacts our health. Topics discussed include urban heat islands, air pollution and dispersion modelling, pollen forecasting and predicting the wind-borne spread of animal diseases. Each hour long workshop culminates in a dramatic demonstration that uses dry ice to represent clean air circulating from mountains, along rivers and into cities. Here we present an overview of Sandscape, identify the strengths and challenges of such a collaborative, innovative and playful approach to public engagement and share the results of our evaluation. Sandscape was originally supported by the Met Office and the Wellcome Trust, and produced by Einstein's Garden in collaboration with the Met Office, scientists from the University of Exeter and sand sculptors from Sand in Your Eye. It was first presented in Einstein's Garden at Green Man festival 2015, an independent music and arts festival held annually in Wales, and has since been invited to run at the 2015 Bournemouth Arts By the Sea Festival and Teignmouth's TRAIL Sculpture Festival in the summer of 2016.

  14. The StorySpinner Sculptural Reader

    OpenAIRE

    Hooper, Clare; Weal, Mark

    2005-01-01

    This demo is of a hypertext reading system called StorySpinner. It follows the sculptural hypertext methodology and has been used as a test bed for experimenting with the authoring of narrative flow in automatically generated stories. Readers are able to select and read one of two available stories. Reading a story involves selecting tarot cards which are mapped to chunks of story text based on possible interpretations of the cards and information concerning current story state.

  15. ' "Life is Movement": Vernon Lee and Sculpture'

    DEFF Research Database (Denmark)

    Østermark-Johansen, Lene

    2018-01-01

    How do living, breathing human bodies respond to the inert bodies of sculpture? This article examines some of the art-theoretical and psychological writings of Violet Paget (‘Vernon Lee’) and Clementina Anstruther-Thomson of the 1880s and 1890s in an attempt to map the evolution of their formalist...... from Lee’s early essays in Belcaro: Being Essays on Sundry Aesthetical Questions (1881) to the late collaborative volume Art and Man (1924)....

  16. Beauty and ugliness in Olmec monumental sculpture

    OpenAIRE

    Baudez, Claude-François

    2015-01-01

    Beauty and ugliness in Olmec monumental sculpture. Since our Western art tradition has put such a prize on naturalism, we tend to think that other civilizations valued it as much as we did and do. I contend that Olmec monumental art illustrates the opposite, and suggest that the Olmecs most appreciated the anthropomorphic statues that incorporated feline features, and disliked the very naturalistic style of the colossal heads. The latter represented the severed heads of opponents who probably...

  17. Visual Identity of Malaysian Modern Sculpture

    Directory of Open Access Journals (Sweden)

    Abdul Halim Husain

    2014-10-01

    Full Text Available An artwork is the manifestation of an artist’s utilization of a variety of approaches, which is closely related to the idea of an artist, media and technique. The manipulation of an artwork is based on the relationship of an artist, idea and media, through formalistic approaches and the surrounding community. Understanding of the visual identity is related to other disciplines in fine art, such as painting, printing and drawing, and new media because of the nature of its context, which is based on the physical form and space. The aim of this research is to generate knowledge on visual identity through sculpture. The research explores the forms and the symbolic meanings based on the influence of the local community and social system. This study employs the cultural concept as a system to create an understanding framework to the process of creating artwork. The qualitative approach is used as the methodology framework, which is deemed as suitable to the problem of investigating the visual identity in sculptures. The findings uncover that Malaysian sculptures synergize harmoniously the value system with modern expression, through belief, surroundings, needs and social requirements. These findings contribute to the knowledge of art, generally, that can be used in other fields of art in the process of creation and appreciation.

  18. Seed sculpture of Polish species of the genus Plantago L.

    Directory of Open Access Journals (Sweden)

    Małgorzata Klimko

    2011-01-01

    Full Text Available The paper presents results of research on seed sculpture of Plantago major, P. intermedia, P. media, P. coronopus subsp. coronopus, P. maritima subsp. maritima, P. atrata subsp. carpatica, P. lanceolata and P. arenaria. Special attention was paid to the sculpture of the external layer of the testa. Observations were made under a light microscope and a scanning electron microscope. The sculpture typical for each species was presented in micrographs. The results indicate that seed sculpture is a very good interspecific identification feature. The study also confirmed that P. maritima should not be assigned to the section Coronopus DC., but to a separate section Maritima Rahn.

  19. Review of the research on “structural bionic” method of large sculpture

    Science.gov (United States)

    Yin, Jiang; Yang, Wenchang

    2017-09-01

    This paper presented the basic concept of bionic sculpture and summarized the application status of “structural bionic”theory in large bionic sculpture field. Introduced the development trend and challenges of large bionic sculpture and pointed out that the sculpture's “structural bionic” can bring higher mechanical performance of the new structure and system, The evaluation method and structure design for large bionic sculpture are urgently needed.Finally prospected the market of the large bionic sculpture.

  20. Virtual Steel Connection Sculpture--Student Learning Assessment

    Science.gov (United States)

    Chou, Karen C.; Moaveni, Saeed; Drane, Denise

    2016-01-01

    A Virtual Steel Connection Sculpture was developed through a grant from the National Science Foundation. The Virtual Sculpture is an interactive tool that shows students and anyone interested in connections how steel members are connected. This tool is created to complement students' steel design courses. The features of this educational tool,…

  1. The Sculptural Elements in Kwagh-Hir Popular Theatre: The ...

    African Journals Online (AJOL)

    Moreover, recent study has registered an increasing (influence of globalization) on aspects of Kwagh-hir sculpturing and themes. This paper attempts a scrutiny of the sculptural element in Kwagh-hir theatre as a complement to its other features, identifying and tracing its growth from its beginning to its current stage within ...

  2. Shaping space: facial asymmetries in fifth-century Greek sculpture

    NARCIS (Netherlands)

    Hochscheid, H.; Hamel, R.; Wootton, W.; Russell, B.; Libonati, E.

    2015-01-01

    The phenomenon of optical correction in Classical Greek sculpture has been attested by both ancient authors and modern scholars. Despite the apparent normalcy of optical correction in sculpture, however, there are no obvious reasons for it and how such correction worked in statues is a question

  3. Apical Shell Sculpture of some African Freshwater Limpets ...

    African Journals Online (AJOL)

    A Scanning Electron Microscope has been used to describe in detail the apical shell sculpture of sevenAfrican species (three genera) of freshwater limpet snails (Ancylidae). The apical sculpture of Ancylus fluviatilis (? syn. strigatus and ? brondeli) is striate, but quite different in basic pattern from the other three striate ...

  4. Mother goddesses with boat motifs on stone sculptures from Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Kerkar, R.; Gaur, A.S.

    to assign a particular date for these sculptures on the style basis as they belong local folk tradition. However, there state of present condition and comparison with modern sculpture indicate that these could be much older which need to be debated...

  5. Making Sense: Interactive Sculptures as Tangible Design Material

    DEFF Research Database (Denmark)

    Jensen, Mads Vedel; Stienstra, Marcelle

    2007-01-01

    is experienced. The exercise utilizes the designer’s own bodily experiences in the design of new tangible interfaces. The design exercise was done with a group of design students. We asked them to design interactive sculptures to convey the interaction qualities they had extracted from video material....... The interactive sculptures served as a physical reflective tool that allowed the students to test and experience the qualities of interaction they wanted to bring into a new design, before they moved on to designing the actual product. We conclude that interactive sculptures serve as a rich design material...

  6. Handedness, Hinduism and sculpture: searching for evidence of lateralisation.

    Science.gov (United States)

    Bhushan, Braj; Rai Sapru, Shikha

    2008-07-01

    The majority of people throughout the world show extreme preference for the right hand. We studied lateral bias depicted in ancient Indian sculptures dating between the 7th and 9th centuries ad. A total of 288 sculptures were selected from various excavation sites/museums and the frequencies were computed on 13 different criteria in order to see the preferential bias for hand depicted in sculptures of male and female figures. The findings are discussed in the light of Hindu mythology and rituals.

  7. 4D Visualization of Painted Sculpture and Murals

    Science.gov (United States)

    Ai, M. Y.; Tong, H.; Shen, L.; Wang, R. X.; Zhang, F.; Zhang, Z. C.; Hu, Q. W.; Zhu, Y. X.; Zhang, H.

    2015-08-01

    Most cultural heritage applications address visualization with using various media or platforms: desktop-based multimedia presentations, museum kiosks, or videos produced with computer animation. However, these techniques can not directly reveal or show the course that the colorful surface of painted sculpture and murals becomes faint along with the change of the climate and time. Most current techniques just preserve the current appearance and disseminate the current situation of the painted sculpture and murals. The course how these forms of cultural heritage change along the time has not been visualized. In this paper we developed an approach to modelling of painted sculpture and murals that has undergone changes over the years. Different hypotheses has also be given if there is uncertainty. A painted sculpture of Mogao Grottoes is used to demonstate this approach.

  8. Photogeology: Part G: structural aspects of Imbrium sculpture

    Science.gov (United States)

    Scott, David H.

    1972-01-01

    Apollo 16 metric photographs taken at low to high Sun angles (from approximately 7° to 40°) provide the first stereographic coverage of the distinctive landforms collectively referred to as "Imbrium sculpture" (refs. 29-40 and 29-41). The sculpture consists of a series of nearly linear ridges and troughs extending radially outward for more than 1000 km from the rim of the Imbrium Basin. The sculpture is particularly well developed in the highlands southwest of the basin, where individual segments have lengths measured in tens of kilometers. THe origin of the ridges and troughs, whether by deposition and impact scoring by fluidized clouds of ejecta from the Imbrium Basin or by faulting and volcanism during and subsequent to basin formation, is controversial. Similar appearing features occur around other large basins on both the near and far sides of the Moon; thus, information leading to a better interpretation of Imbrium sculpture has significance throughout the Moon.

  9. Cross Sectional Attitudes of Public Sculpture Matrix in Southwestern Nigeria

    Directory of Open Access Journals (Sweden)

    Moses Akintunde Akintonde

    2016-06-01

    Full Text Available Public outdoor sculpture practice in the Southwestern Nigeria entails different types of attitudes. These attitudes are discernable from the stage of commissioning of work, its conceptualization to the display and uses in the public sphere generated diverse fundamental, constant technical issues. Some are explicitly alluring while others are absurd, fleeting and injurious to the practice. However, whatever attitude advanced in the public outdoor sculpture practice, it has not been discussed cross sectionally. The inadequate scholarship attention on the attitudinal issues in outdoor sculpture certainly created art historical gap apt to make the study of contemporary Nigeria art incoherent. Apparently, attitudinal studies certainly involve psychological measurement - a type of instrument that does not required descriptive survey. For this reason, the study was based on qualitative methods. The study categorised various attitudes in outdoor sculpture practice in the studied area into pre-unveiling, unveiling and post unveiling stages and critically examined them. Some attitudes in the practice of the art were observed to be stimulant for advancement; invariably others are clearly incongruous to the spirit of typical Yoruba societal value orientation in orderliness, therefore degrading and detrimental to the development of the outdoor sculpture in the public sphere.Keywords: Art patron; cross sectional attitude; outdoor sculpture; post-unveiling; pre-unveiling; public art; Southwestern Nigeria; unveiling.

  10. The thinker: opposing directionality of lighting bias within sculptural artwork

    Science.gov (United States)

    Sedgewick, Jennifer R.; Weiers, Bradley; Stewart, Aaron; Elias, Lorin J.

    2015-01-01

    Individuals tend to perceive the direction of light to come from above and slightly from the left; it has been speculated that this phenomenon is also producing similar lighting preferences within 2-dimensional artworks (e.g., paintings, advertisements). The purpose of the present study was to address if lighting bias was present in the 3-dimensional medium of sculpture by implementing a virtual art gallery lighting paradigm. Thirty-nine participants completed a computer task that consisted of 48 galleries each containing one sculpture (24 original sculptures, 24 mirror-reversed) which was surrounded by eight lights (above/below, left/right, front/back). Participants would select one light source to illuminate the sculpture in a manner they perceived to be the most aesthetically pleasing. The results indicated a significant preference for lights positioned from above and from the right, a finding that is contradictory to previous lighting bias research examining artworks. An interpretation for the rightward bias applies the perceptual concept of subjective lighting equality. Objects illuminated from the left typically appear brighter in comparison to right-side lighting; in sculpture, however, increased luminosity can reduce the sculptural detail, and may have been compensated via right-side lighting choices within the lighting task. PMID:25999840

  11. Shaving a Shell: Effect of Manipulated Sculpture and Feeding on Shell Growth and Sculpture Development in Nucella lamellosa (Muricidae: Ocenebrinae).

    Science.gov (United States)

    Webster, Nicole B; Palmer, A Richard

    2016-02-01

    Gastropod shell sculpture offers a novel tool for studying morphological patterning. Existing shell features may be manipulated experimentally to test how alteration affects subsequent shell growth and form. Axial sculpture occurs in many gastropod groups, and spacing of sculpture may be regular or irregular. But how gastropods control sculpture placement during shell growth is unknown. We studied the growth and positioning of axial lamellae in the muricid Nucella lamellosa, and compared these to the superficially similar axial varices seen in other muricids. First, we tested whether the feeding rate had any effect on the rate of addition or positioning of new lamellae. Second, we tested what effect previous shell sculpture had on lamellar placement, and shell growth in general, by removing all shell sculpture and allowing snails to grow over the "shaved" shell surface. Lamellar growth appeared to be relatively plastic; spacing was highly variable both within and among individual snails, and 1-2 weeks were required to complete the addition of a new lamella. Body growth rate was the primary determinant of lamellar growth; past lamellae had no effect on placement of new lamellae or rate of shell length increase. Feeding rate and body size affected only growth in shell length, and had no direct effect on spacing or on the rate of addition of new lamellae. The growth of axial lamellae in N. lamellosa differed from that of varices by exhibiting neither a) regular spacing nor b) a growth hiatus after completion of a lamella. Significantly, despite the obvious impediment of previous sculpture to future shell growth, removal of this sculpture had no observable effect on the rate of body growth or on any aspect of subsequent lamellar growth. © 2016 Marine Biological Laboratory.

  12. Microanalysis of pictorial layers in polychrome sculptures

    International Nuclear Information System (INIS)

    Mendoza Cuevas, Ariadna

    2008-01-01

    Cross section samples from polychrome wood sculpture are analyzed by optical microscopy, the nuclear techniques: micro X Ray Fluorescence, micro Proton induced Xray Emission coupled with Rutherford Backscattering and the traditional method by Scanning Electronic Microscopy with Energy Dispersive Xray fluorescence detection (SEMEDX) microanalytical methods. Special emphasis is dedicated to mXRF, a novel advanced technique developed thanks to the last achievements of the Xray optics that can be available by modifying conventional laboratory XRF spectrometer, representing an alternative to the traditional and expensive SEMEDX stratigraphic analysis of pictorial works. The results are compared with respect to spatial resolution to differentiate pictorial layer structure and elemental sensitivity. Number of layer, relative position of layer, layer thickness and chemical composition of pigments are determined in the characterization of valuable polychromes of once church San Juan de Letrán in order to obtain information about their “material history” that should contribute to its provenance and attribution research. The pigments used in this artistic works were identified by their characteristic elements. The elemental distribution maps obtained by the used nuclear techniques precisely reproduced microphotographies obtained by means of Light Microscopy. (author)

  13. Sub-wavelength antireflection coatings from nanostructure sculptured thin films

    International Nuclear Information System (INIS)

    Schubert, E.

    2007-01-01

    Nanostructure sculptured thin films from SiO 2 are grown on quartz substrates by ion beam sputter deposition using rotating substrate motion accommodated to an oblique angle of incidence for the particle flux. Structural peculiarities of sculptured thin films have an intriguing impact on the optical response upon reflection of light with different wavelengths. The reflectivity of quartz substrates coated with SiO 2 sub-wavelength nanostructures is simulated by means of effective medium theory and antireflection is predicted for the deep ultraviolet spectral region. Spectroscopic ellipsometry and reflectivity measurements are performed on SiO 2 sculptured thin films and antireflection near λ = 193 nm is found. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  14. Waiting for Art: The Experience of Real Time in Sculpture

    Directory of Open Access Journals (Sweden)

    Elizabeth Buhe

    2011-05-01

    Full Text Available Why and how does some contemporary art make us wait, and why does the beholder choose to stay? This study seeks to answer this question by exploring what happens to the viewer while waiting in front of a “time sculpture,” a term coined here to mean a three-dimensional artwork that is dynamic over a set period of time. Through an analysis of select works by artists Anish Kapoor, Amelia Whitelaw, Michael Sailstorfer, and Roman Signer, the article posits that while in front of these time sculptures, the viewer experiences an anxiety of waiting and temporal confusion that glues him to the spot. Ultimately, by drawing upon Henri Bergson’s concept of duration, the essay suggests that the viewership of time sculpture allows for a heightened state of perception. Normal 0 false false false EN-US X-NONE X-NONE

  15. THE DANCING SCULPTURES OF THE 19TH CENTURY EUROPEAN ART

    Directory of Open Access Journals (Sweden)

    Sibel ALMELEK ISMAN

    2015-04-01

    Full Text Available Dance has been an indispensable element of human life for centuries. Painters and sculptors have created the dynamism of dance steps either on the canvas or stone with the same excitement. Charits, Nymphs, Bacchantes and Satyrs, the Greek and Roman mythological figures who attract attention with their dances have been a source of inspiration for artists. In this research, the dancing sculptures of the 19th century which is an interesting period in European art because of its witnessing of long term styles like Neoclassicism and Romanticism and short term movements such as Realism and Impressionism are examined. Examples of sculptures which brings dance to life before and after the 19th century have also been mentioned. The likenesses as well as dissimilarities in the way the arts of painting and sculpture approach to the theme of dance has been briefly evaluated.

  16. A Virtual Steel Sculpture for Structural Engineering Education: Development and Initial Findings

    Science.gov (United States)

    Dib, Hazar Nicholas; Adamo-Villani, Nicoletta

    2016-01-01

    We describe the development and evaluation of a virtual steel sculpture for engineering education. A good connection design requires the engineer to have a solid understanding of the mechanics and steel behavior. To help students better understand various connection types, many schools have acquired steel sculptures. A steel sculpture is a…

  17. Sculpture africaine. Blessures et altérité

    Directory of Open Access Journals (Sweden)

    Gaetano Speranza

    2009-03-01

    Full Text Available Au delà de la notion de “blessure” relative à l’objet, l’auteur s’attache aux traumatismes culturels résultant de la rencontre entre la sculpture africaine et le monde occidental. Un exemple particulier est celui des instruments de musique ethnographiques, dont la restauration est souvent tributaire des conceptions occidentales.Beyond the notion of « injury » for the object, the author dwells on cultural traumatisms resulting from the meeting between African sculpture and the western world. A particular example is the one of ethnographical musical instruments for which restoration is often tributary of western conceptions.

  18. Effects of Photography on Acquisition of Sculpture Skills among ...

    African Journals Online (AJOL)

    The study investigated the effects of photography on acquisition of sculpture skills among Junior Secondary School Students in Osun State. Forty students were randomly selected from two schools. The two schools were purposefully selected from fifty secondary schools in Ife Central Local Government Council Area of Osun ...

  19. The Eco-Sculpture Assignment: Using Art to Scaffold Metacognition

    Science.gov (United States)

    Polegato, Rosemary

    2014-01-01

    The Eco-Sculpture Assignment demonstrates that art may be used as a conduit to scaffold metacognition in marketing courses. Theoretical underpinnings are drawn from the literature on pedagogy used in general, marketing, and art education contexts. The assignment is described in detail, followed by examples of learner response that illustrate…

  20. Sculpture: Creative Designs with Modern Materials (Tentative Course Outline).

    Science.gov (United States)

    Dubocq, Edward R.

    This document reports on a course in comprehension and application of various techniques of sculpture and collage, using a contemporary point of view. Students will work with contemporary materials such as wood, metals, plaster, plastics, styrofoam, and many other cardboard basic materials suitable for creative design products. This unit will…

  1. 37 CFR 202.10 - Pictorial, graphic, and sculptural works.

    Science.gov (United States)

    2010-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Pictorial, graphic, and... Pictorial, graphic, and sculptural works. (a) In order to be acceptable as a pictorial, graphic, or... utility or design patent will not affect the registrability of a claim in an original work of pictorial...

  2. Afterword: Victorian Sculpture for the Twenty-First Century

    Directory of Open Access Journals (Sweden)

    David J. Getsy

    2016-06-01

    Full Text Available Commenting on the directions proposed by this issue of '19', the afterword discusses the broad trends in twenty-first century studies of Victorian sculpture and the opportunity for debate arising from the first attempt at a comprehensive exhibition.

  3. Ken Okoli's absracted landscape sculptures: The Zaria influence ...

    African Journals Online (AJOL)

    In art history scholarship the study of landscape has always been focused on the representation of beautiful sceneries in painting. Most of the attempt to represent landscape in relief sculpture has also been centered on the representation of human figures, animal forms, and generally on decorative patterns which form the ...

  4. NATURE AND SCULPTURE IN THE CREATION OF AFRICAN ...

    African Journals Online (AJOL)

    sculptural images of African gods and other handicrafts have also been quite vocal. The combination of these .... architectural perspective, or as the representation of domicile structures, we may say those types of setting .... Nigerian theatre had evolved three noticeable genres with the full influence of European technical ...

  5. TRENDS IN OWO TRADITIONAL SCULPTURES: 1995 – 2010 ...

    African Journals Online (AJOL)

    HON DEJI

    techniques and styles of Owo traditional sculptures, their resemblances and relationship with. Benin and Ife ... titles, socials, cults, street names, music, dance and royal costumes etcetera propelled, rekindled and influenced the ... These trees are very good for various types of carving such as veranda posts, doors, pillars ...

  6. The Golden Beauty: Brain Response to Classical and Renaissance Sculptures

    Science.gov (United States)

    Di Dio, Cinzia; Macaluso, Emiliano; Rizzolatti, Giacomo

    2007-01-01

    Is there an objective, biological basis for the experience of beauty in art? Or is aesthetic experience entirely subjective? Using fMRI technique, we addressed this question by presenting viewers, naïve to art criticism, with images of masterpieces of Classical and Renaissance sculpture. Employing proportion as the independent variable, we produced two sets of stimuli: one composed of images of original sculptures; the other of a modified version of the same images. The stimuli were presented in three conditions: observation, aesthetic judgment, and proportion judgment. In the observation condition, the viewers were required to observe the images with the same mind-set as if they were in a museum. In the other two conditions they were required to give an aesthetic or proportion judgment on the same images. Two types of analyses were carried out: one which contrasted brain response to the canonical and the modified sculptures, and one which contrasted beautiful vs. ugly sculptures as judged by each volunteer. The most striking result was that the observation of original sculptures, relative to the modified ones, produced activation of the right insula as well as of some lateral and medial cortical areas (lateral occipital gyrus, precuneus and prefrontal areas). The activation of the insula was particularly strong during the observation condition. Most interestingly, when volunteers were required to give an overt aesthetic judgment, the images judged as beautiful selectively activated the right amygdala, relative to those judged as ugly. We conclude that, in observers naïve to art criticism, the sense of beauty is mediated by two non-mutually exclusive processes: one based on a joint activation of sets of cortical neurons, triggered by parameters intrinsic to the stimuli, and the insula (objective beauty); the other based on the activation of the amygdala, driven by one's own emotional experiences (subjective beauty). PMID:18030335

  7. a Target Aware Texture Mapping for Sculpture Heritage Modeling

    Science.gov (United States)

    Yang, C.; Zhang, F.; Huang, X.; Li, D.; Zhu, Y.

    2017-08-01

    In this paper, we proposed a target aware image to model registration method using silhouette as the matching clues. The target sculpture object in natural environment can be automatically detected from image with complex background with assistant of 3D geometric data. Then the silhouette can be automatically extracted and applied in image to model matching. Due to the user don't need to deliberately draw target area, the time consumption for precisely image to model matching operation can be greatly reduced. To enhance the function of this method, we also improved the silhouette matching algorithm to support conditional silhouette matching. Two experiments using a stone lion sculpture of Ming Dynasty and a potable relic in museum are given to evaluate the method we proposed. The method we proposed in this paper is extended and developed into a mature software applied in many culture heritage documentation projects.

  8. ARTISTIC AND PRODUCTION FEATURES OF PORCELAIN SCULPTURE BY AUGUST SPIESS

    Directory of Open Access Journals (Sweden)

    Екатерина Сергеевна Хмельницкая

    2014-02-01

    Full Text Available The article deals with the identification and attribution of artistic production and features of porcelain sculpture created by the chief scultor of the Imperial Porcelain Factory in St. Petersburg August K. Spiess . Porcelain through creativity of Spies become so amazingly diverse, as it used to be in the XVIII century . Creative heritage of A. Spiess could be identified as a phenomenon that naturally associated with the broader social and cultural processes , typical for Russian art of the second half of the XIX century. However , in contrast to the next generation of sculptors , Spies activity does not go beyond the existence of porcelain production , and the sculptor has not sought to create works that can approve a porcelain sculpture in the eyes of a higher status.DOI: http://dx.doi.org/10.12731/2218-7405-2014-1-6

  9. Typical conservation problems of polychrome wooden sculptures in Slovenia

    Directory of Open Access Journals (Sweden)

    Martina Vuga

    2015-01-01

    Full Text Available The Slovene ethnic territory lies at the contact of Italian and German cultural influences, which can also be traced in gilded works of art. The majority of wooden Gothic art heritage has been lost for good, but a great number of wooden "golden altars" from the 17th century and large 18th century baroque altarpieces with outstanding sculptures survive. Conservators-restorers face great problems resulting from repeated restoration interventions of a great deal of these works of art. The paper describes a recent treatment undertaken at the National Gallery of Slovenia of an 18th century water gilded sculpture from no more existing altar, which was subsequently and typically overpainted several times. The case study is used to illustrate the problems encountered in overpaint removal from gilded areas.

  10. Metal corrosion in polychrome baroque lead sculptures: a case study

    OpenAIRE

    Faria,Dalva L. A. de; Puglieri,Thiago S.; Souza,Luiz Antonio C.

    2013-01-01

    Polychrome lead sculptures from Oratory Museum in Ouro Preto (Minas Gerais, Brazil) kept inside a glass showcase were severely degraded. The formed corrosion products were analyzed by X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray fluorescence (EDX) and Raman microscopy and proved to be mostly Pb carbonates and formates. Although carbonate is a very common finding in Pb atmospheric corrosion, Pb formates ...

  11. Rock Engravings and Sculptures of North Guwahati, Assam

    Directory of Open Access Journals (Sweden)

    Dwipen Bezbaruah

    2016-02-01

    Full Text Available Evidences of rock engravings and sculptures, in Assam, are predominantly found to occur in the vicinity of the temples. Incidence of images of Gods and Goddesses, faunal and floral motif are invariably more. Apart from these, some geometric designs are also perceived. Such tangible archaeological heritages are considered important evidences for understanding the past in a more meaningful way. Therefore, it is pertinent to systematically document these sites and the remains before natural and anthropogenic obliteration. The objective of the present paper is to record and document the rock engravings and sculptures observed in the archaeological sites, namely Dirgheswari, Aswakranta, Manikarneswar, Rudreswar and Kanai Boroshi bowa of North Guwahati in Kamrup district, Assam, which are protected and preserved by the Directorate of Archaeology, Assam and to understand the archaeological context of the sites and their remains. The data for the present paper have been collected through field visit and Exploration was conducted in dry and winter season. The findings of the present work comprises of some sculptures of Ganesa, Yama, Sage, Kali, deities, bull without head, human figures, broken piece of a tiger, remains of door frame or pillar and shrines. Series of dot marks, cut marks, inscription, image of Shiva, foot impression, chess board, square, bow, signs, female figurine, and elephant engravings constitute the rock engravings observed in the area.

  12. External-beam PIXE analysis of small sculptures

    Energy Technology Data Exchange (ETDEWEB)

    Gyodi, I.; Demeter, I.; Hollos-Nagy, K.; Kovacs, I.; Szokefalvi-Nagy, Z. E-mail: sznagy@rmki.kfki.hu

    1999-04-02

    Non-destructive analysis of precious art objects is an important tool to solve provenance problems or to facilitate restoration. External beam PIXE analysis is one of the most powerful and popular methods used in this respect. The paper summarises the external beam PIXE set-up at the Accelerator Laboratory in Budapest, and two selected applications are described. Different parts of a small Cambodian metal sculpture probably made in the 11th century were analysed. It was observed that the sculpture was composed of an iron core and an outer bronze shell. This sculptural technique was well known in the Middle-East but no indication has been found about its use in the Far-East, yet. Before its restoration paint traces on a wooden relief of St. Jerome made by an unknown artist in about 1600 were analysed. Different white and red paints were distinguished at selected points and the presence of titanium on a certain part of the relief was attributed to a repainting in modern times.

  13. Introduction to British Sculpture Abroad in the 1960s

    Directory of Open Access Journals (Sweden)

    Jon Wood

    2016-07-01

    Full Text Available In the 1960s, British sculpture enjoyed a complex transitional life, taking on a new, bold, and increasingly internationalized profile, at the very same time that its forms and meanings were being challenged and contested. Both in Britain and beyond its shores, sculpture experienced substantial reorientation at the same time as it developed a rich and complicated “import” and “export” life, conceptually, commercially, and curatorially. When “Sculpture” was “British” and “Abroad”, its “abroad-ness” was not always so explicitly visible, since its forms and concerns frequently chimed with sensibilities and approaches that were emerging elsewhere too, whether they were figurative or abstract, Constructivist or Pop. At the same time, when sculpture was being displayed in Britain, whether in terms of groups, schools, and/or recent tendencies, it was increasingly described as “British Sculpture”. Visual evidence of foreign impact and exchange gradually emerged at the same time as this national and generational trope became a cultural identifier on a broader cultural landscape.

  14. Moving into Uncertainty: Sculpture with Three- to Five-Year-Olds

    Science.gov (United States)

    Wien, Carol Anne

    2008-01-01

    This article describes a six-month emergent curriculum project on sculpture in a Reggio-inspired program and the thinking behind teachers' decisions in supporting the children's developing ideas. ["Moving into Uncertainty: Sculpture with Three- to Five-Year-Olds" was written with Bobbi-Lynn Keating, Annette Coates, and Barbara Bigelow.

  15. Analysis of a Brazilian baroque sculpture using Raman spectroscopy and FT-IR.

    Science.gov (United States)

    Freitas, Renato P; Ribeiro, Iohanna M; Calza, Cristiane; Oliveira, Ana L; Felix, Valter S; Ferreira, Douglas S; Pimenta, André R; Pereira, Ronaldo V; Pereira, Marcelo O; Lopes, Ricardo T

    2016-02-05

    In this study, samples were taken from the sculpture of Our Lady of Sorrows and analyzed by Raman spectroscopy and FT-IR. This sculpture has been dated to the early eighteenth century. Samples were also examined using optical microscopy and Energy Dispersive Spectroscopy (EDS). Based on chemical analysis, the pigments vermilion [HgS], massicot [PbO] and azurite [Cu3(CO3)2(OH)2]were found in the sculpture polychrome. The results indicate that the green polychrome of the sculpture's mantle comes from the blending of massicot and azurite. Because the literature reports that the mantle of the Our Lady of Sorrows sculpture is blue, the mixing of these pigments results from a production error. The results also indicate the presence of Au in the sculpture, which indicates the originality of the piece. The results from this study helped restorers to choose the appropriate procedures for intervening in the sculpture and contributed to the knowledge about the manufacturing process of Brazilian baroque sculptures. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Analysis of a Brazilian baroque sculpture using Raman spectroscopy and FT-IR

    Science.gov (United States)

    Freitas, Renato P.; Ribeiro, Iohanna M.; Calza, Cristiane; Oliveira, Ana L.; Felix, Valter S.; Ferreira, Douglas S.; Pimenta, André R.; Pereira, Ronaldo V.; Pereira, Marcelo O.; Lopes, Ricardo T.

    2016-02-01

    In this study, samples were taken from the sculpture of Our Lady of Sorrows and analyzed by Raman spectroscopy and FT-IR. This sculpture has been dated to the early eighteenth century. Samples were also examined using optical microscopy and Energy Dispersive Spectroscopy (EDS). Based on chemical analysis, the pigments vermilion [HgS], massicot [PbO] and azurite [Cu3(CO3)2(OH)2] were found in the sculpture polychrome. The results indicate that the green polychrome of the sculpture's mantle comes from the blending of massicot and azurite. Because the literature reports that the mantle of the Our Lady of Sorrows sculpture is blue, the mixing of these pigments results from a production error. The results also indicate the presence of Au in the sculpture, which indicates the originality of the piece. The results from this study helped restorers to choose the appropriate procedures for intervening in the sculpture and contributed to the knowledge about the manufacturing process of Brazilian baroque sculptures.

  17. Stone sculptures of goddesses on the boats from Goa, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Gaur, A; Kerkar, R.

    goddess panels. A few sculptures reflect influence of folk art traditions in Goa. On the basis of lion figures in a few sculptured panels indicate that these boat motifs must have been engraved during the Kadamba period (10 th - 13 th) when Goa witnessed...

  18. Go with the flow: conservation of a floating sculpture from 1961 made from glass fibre-reinforced polyester resin

    NARCIS (Netherlands)

    Beerkens, L.; Stigter, S.; van Oosten, T.; van Keulen, H.; Keneghan, B.; Egan, L.

    2008-01-01

    Marta Pan’s Sculpture flottante, Otterlo was commissioned by the Kröller-Müller Museum for a pond at the entrance of the new sculpture garden that opened in June 1961. The floating sculpture is made from glass fibre-reinforced polyester resin and is now coated with white paint layers. The top is

  19. 25 CFR 309.20 - What are examples of sculpture, carving, and pipes that are Indian products?

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false What are examples of sculpture, carving, and pipes that... INTERIOR PROTECTION OF INDIAN ARTS AND CRAFTS PRODUCTS § 309.20 What are examples of sculpture, carving, and pipes that are Indian products? (a) Sculpture, carving, and pipes made by an Indian, including...

  20. From “The New Sculpture” to Garden Statuary: the suppression of Abstract Expressionist sculpture

    Directory of Open Access Journals (Sweden)

    Meghan Bissonnette

    2015-12-01

    Full Text Available In the 1940s, David Smith, David Hare, Herbert Ferber, Ibram Lassaw, Seymour Lipton and Theodore Roszak were part of a new generation of sculptors working in New York who used welding and other direct-metal techniques to make abstract sculpture. In the 1950s, Abstract Expressionist sculpture was praised for its vitality and inventiveness, yet beginning in the 1960s these works gradually fell out of favour. The sole exception is David Smith, who has been upheld as the only sculptor of merit from this period. This study will contend that the suppression of Abstract Expressionist sculpture is largely due to Clement Greenberg and the lasting impact of his writings. Furthermore, his critique of the new sculpture has shaped subsequent assessments by Michael Leja, Kirk Varnedoe, and Edward Lucie-Smith. It has also contributed to the belief, still current today, that Abstract Expressionism is a movement of painters with no comparable counterparts in sculpture.

  1. Interlocked by nanoscale sculpturing: pure aluminum copper contacts (Conference Presentation)

    Science.gov (United States)

    Gerngross-Baytekin, Melike; Gerngross, Mark Daniel; Carstensen, Jürgen; Adelung, Rainer

    2017-06-01

    Connecting metals reliable with different corrosion potential is a well-known challenge. An extreme example are copper aluminum contacts. Galvanic corrosion occurs if the two different metals are in contact with each other and an electrolyte, the aluminum becomes susceptible to corrosion under current flow. Usually, antioxidant pastes containing metals are employed but create difficulties e.g. for fatigue resistant power electronic connections. The recently described process of nanoscale sculpturing [1] offers an alternative. Usually, if the surface of metals like aluminium are prepared they are just arbitrary cuts through the bulk. There is no optimization of the surface grain structure towards stability at all. Neither the crystalline facets in the grains are in their most stable orientation nor is the protective oxide shell the most stable one. The nanoscale sculpturing approach is carving out the most stable grains and planes by chemical or electrochemical treatment. The decisive trick is that the chemistry is targeting towards the instable oxide and not the metal. Aluminium sample surfaces including alloys like AA575 exhibit afterwards single crystalline surface facets covered with nanoscale stable oxide films. Galvanically deposited copper forms extremely reliable interlocked connections on top, even allowing for soldering on top of their surface.

  2. Vapor and liquid optical monitoring with sculptured Bragg microcavities

    Science.gov (United States)

    Oliva-Ramirez, Manuel; Gil-Rostra, Jorge; López-Santos, Maria Carmen; González-Elipe, Agustín R.; Yubero, Francisco

    2017-10-01

    Sculptured porous Bragg microcavities (BMs) formed by the successive stacking of columnar SiO2 and TiO2 thin films with a zig-zag columnar microstructure are prepared by glancing angle deposition. These BMs act as wavelength-dependent optical retarders. This optical behavior is attributed to a self-structuration of the stacked layers involving the lateral association of nanocolumns in the direction perpendicular to the main flux of particles during the multilayer film growth, as observed by focused ion beam scanning electron microscopy. The retardance of these optically active BMs can be modulated by dynamic infiltration of their open porosity with vapors, liquids, or solutions with different refractive indices. The tunable birefringence of these nanostructured photonic systems has been successfully simulated with a simple model that assumes that each layer within the BMs stack has uniaxial birefringence. The sculptured BMs have been incorporated as microfluidic chips for optical transduction for label-free vapor and liquid sensing. Several examples of the detection performance of these chips, working either in reflection or transmission configuration, for the optical monitoring of vapor and liquids of different refractive indices and aqueous solutions of glucose flowing through the microfluidic chips are described.

  3. Three dimensional computerized microtomography in the analysis of sculpture.

    Science.gov (United States)

    Badde, Aurelia; Illerhaus, Bernhard

    2008-01-01

    The Alte Nationalgalerie, Staatliche Museen zu Berlin (SMB) and the Federal Institute for Materials Research and Testing (BAM) tested the accomplishment of the three dimensional computerized microtomography (3D-microCT)-a new flat panel detector computerized tomography (CT) system at the BAM with extended energy range, with high voltage X-ray tubes (330 and 225 kV), with micrometer focal spot size and micrometer resolution and enlarged object size (up to 70 cm diameter)-for examining plaster statues. The high spatial and density resolution of the tomograph enable detailed insights into the individual work processes of the investigated cast plaster statues. While initiated in support of the conservation process, computed tomography (CT) analysis has assisted in revealing relative chronologies within the series of the cast works of art, thus serving as a valuable tool in the art-historical appraisal of the oeuvres. The image-processing systems visualize the voids and cracks within and the cuts through the original cast works. Internal structures, armoring, sculptural reworking as well as restorative interventions are virtually reconstructed. The authors are currently employing the 3D-microCT systems at the BAM into the detection of defects in Carrara marble sculpture. Microcracks, fractures, and material flaws are visualized at spatial resolution down to 10 microm. Computerized reconstruction of ultrasound tomography is verified by analyzing correlations in the results obtained from the complementary application of these two non-destructive testing (NDT) methods of diagnosis.

  4. Socio-Psychological Impact of Outdoor Sculptures in Nigeria Urban Cities

    Directory of Open Access Journals (Sweden)

    Allan Francis Ebunola Oladugbagbe

    2016-06-01

    Full Text Available One major element that finds expression at road intersections, parks, gardens, square and open spaces in the urban landscape are outdoor sculptures. Of great significance is the historical information they disseminate, the visual impressions they convey and the aesthetic value they add to the quality of the city. From 1960s and after the civil war, the uses of sculptures for embellishments in public places have increased tremendously in Nigeria. However, outdoor sculpture for the purpose of recreation and relaxation in our built environment has not been adequately addressed scholastically in Nigeria. This paper, therefore, focuses on the social values derivable from the use of sculpture in urban design and the losses that could accrue to the social system if not adequately managed. The values of these sculptures to the socio-psychological development of Nigerians and the beautification of the urban environment are equally emphasized. The study shows that incorporating sculptures into public places without doubt will heighten public appreciation and aesthetic perception and make Nigerian cities unique and vibrant.Keywords: Nigeria urban cities; socio-psychological impact; outdoor sculptures.

  5. Ice Sheets & Ice Cores

    DEFF Research Database (Denmark)

    Mikkelsen, Troels Bøgeholm

    Since the discovery of the Ice Ages it has been evident that Earth’s climate is liable to undergo dramatic changes. The previous climatic period known as the Last Glacial saw large oscillations in the extent of ice sheets covering the Northern hemisphere. Understanding these oscillations known...

  6. Applications of petrography and electron microprobe analysis to the study of Indian stone sculpture

    International Nuclear Information System (INIS)

    Newman, R.

    1992-01-01

    Examples of research on ancient Indian stone artefacts utilizing petrographic examination coupled with qualitative and quantitative electron beam microprobe analysis of specific minerals are described. Types of artefacts discussed include Gandharan schist sculptures, Pala dynasty phyllite and schist objects from eastern India. Hoysala sculptures from Karnataka state (southern India), and sandstone objects from northern India. In spite of the rich history of stone sculpture in the Indian subcontinent, characterization studies to date have been limited in scope, typically involving unprovenanced artefacts. The examples described point to areas in which more extensive research could produce useful information for the provenancing of artefacts. (author)

  7. Stèles et sculptures protohistoriques du Languedoc occidental

    OpenAIRE

    Gailledrat, Éric

    2017-01-01

    Fig. 1 : Carte de situation des sites mentionnés dans le texte Au regard d’autres régions méridionales, et plus précisément la Provence et le Languedoc oriental, l’ensemble culturellement cohérent que forment à l’âge du Fer les terres comprises entre les vallées de l’Hérault et du Lez au Nord, les Pyrénées au Sud, se caractérise par la relative indigence des documents matériels évoquant cultes et croyances situés hors de la sphère domestique (fig. 1). Le corpus des stèles, sculptures et autr...

  8. Reconstruction of sculpture from its profiles with unknown camera positions.

    Science.gov (United States)

    Wong, Kwan-Yee Kenneth; Cipolla, Roberto

    2004-03-01

    Profiles of a sculpture provide rich information about its geometry, and can be used for shape recovery under known camera motion. By exploiting correspondences induced by epipolar tangents on the profiles, a successful solution to motion estimation from profiles has been developed in the special case of circular motion. The main drawbacks of using circular motion alone, namely the difficulty in adding new views and part of the object always being invisible, can be overcome by incorporating arbitrary general views of the object and registering its new profiles with the set of profiles resulted from the circular motion. In this paper, we describe a complete and practical system for producing a three-dimensional (3-D) model from uncalibrated images of an arbitrary object using its profiles alone. Experimental results on various objects are presented, demonstrating the quality of the reconstructions using the estimated motion.

  9. [Model creation in art therapy. A sculpture project at a psychiatric clinic].

    Science.gov (United States)

    Erazo, N; van der Lee, T; Greil, W

    2000-01-01

    Therapeutic modelling has found little attention in the literature. For the first time, the present article reports about sculptural work in psychiatric art therapy. Since 1994 the Psychiatric Hospital Kilchberg/Zürich is carrying out a sculpture project, in which about 30 patients work with sand- or limestone for 2 1/2 hours daily, cared for by eight therapists and protected by detailed safety regulations. At the beginning and the end of each afternoon the patients stand in a circle to communicate inner mood and ideas about the work. An exposition at the end of the project gives the opportunity to demonstrate the sculptures to family, friends and clinical staff. Until now there have been only positive experiences, which speak in favour of a wider use of sculpture in psychiatric art therapy. Sculptural work stimulates the vitality of the patients, who are challenged to use their willpower adaptedly and rhythmically. Especially on patients with autodestructive tendencies sculptural work seems to exert a beneficial influence.

  10. Restitution of sculptural groups using 3D scanners.

    Science.gov (United States)

    Merchán, Pilar; Salamanca, Santiago; Adán, Antonio

    2011-01-01

    Imagine for a moment that you have to solve a 3D jigsaw of which you have lost several pieces. You have also lost the original box-top showing the final picture, and as if that were not enough, some of the pieces you do have may belong to some other jigsaw. This is in essence the sort of challenge that we faced in the novel project that we shall be describing in this paper. The final aim of the project was, with the help of 3D scanners, to digitalize and reconstruct multi-piece classical sculptures. Particularly, we tackle the restitution of the so-called "Aeneas Group", a famous iconographic reference during the Roman Empire. We have undertaken this ambitious project in collaboration with the research department of the Spanish National Museum of Roman Art (MNAR). This paper summarizes the real problems that arose and had to be solved, the innovations, and the main results of the work that we have carried out over these recent years.

  11. Suture techniques in nasal tip sculpture: current concepts.

    Science.gov (United States)

    Lo, S; Rowe-Jones, J

    2007-08-01

    The three-dimensional anatomy and conspicuous location of the nasal tip makes it one of the most challenging sites of facial plastic surgery. This article reviews literature on nasal tip sculpture using suture techniques, as well as the authors' own experience. A search was conducted using Pubmed, the Google internet search engine and the authors' files, using the keywords 'nasal tip', 'suture', 'rhinoplasty' and 'septorhinoplasty'. Common nasal tip suture techniques and suture algorithms are presented, along with a summary of the indications and side effects of each technique. Predictable long-term results are more likely to occur with minimal local tissue excision. Suture techniques remodel the shape of the nasal tip by altering the configuration of, and the relationship between, the tip cartilages and their supporting structures; they also preserve nasal tip anatomy and limit resection. Intra-operatively, the effects are immediately visible, and can be adjusted or reversed. Tip sutures should therefore be considered instead of tissue excision whenever possible.

  12. Restitution of Sculptural Groups Using 3D Scanners

    Science.gov (United States)

    Merchán, Pilar; Salamanca, Santiago; Adán, Antonio

    2011-01-01

    Imagine for a moment that you have to solve a 3D jigsaw of which you have lost several pieces. You have also lost the original box-top showing the final picture, and as if that were not enough, some of the pieces you do have may belong to some other jigsaw. This is in essence the sort of challenge that we faced in the novel project that we shall be describing in this paper. The final aim of the project was, with the help of 3D scanners, to digitalize and reconstruct multi-piece classical sculptures. Particularly, we tackle the restitution of the so-called “Aeneas Group”, a famous iconographic reference during the Roman Empire. We have undertaken this ambitious project in collaboration with the research department of the Spanish National Museum of Roman Art (MNAR). This paper summarizes the real problems that arose and had to be solved, the innovations, and the main results of the work that we have carried out over these recent years. PMID:22164088

  13. PIXE analysis of museum soapstone sculptures from Esie, south west Nigeria

    International Nuclear Information System (INIS)

    Olabanji, S.O.; Olarewaju, V.O.; Onabajo, O.

    1989-05-01

    The PIXE technique was employed for the study of Esie museum stone sculptures using 2.55 MeV protons from the 3 MeV tandem accelerator (NEC 3 UDH) in Lund, coupled with the geological and archaeological findings. The aim is to elucidate and decipher the prodigious but rather enigmatic and bewildering stone sculptures. PIXE results show that the composition of the stone sculptures are 40.69% talc-tremolite schist, 30.88% talc-chlorite schist, 15.20% talc-tremolite-anthophyllite schist and 13.24% talc-amphibolite schist. Thus the composition of Esie sculptures are found to be the same with the locally available talc-schists present around Esie. The geological evidence (mineralogical results) corroborated this as there was no textural or mineralogical difference between the talc-bearing country rock (outcrop) in Esie and the museum soapstone samples studied. Consequently, there is a very high probability that the sculptures were carved using the locally available talc-schists. (author). 7 refs, 4 figs, 2 tabs

  14. Effects of sculpture based art therapy in dementia patients-A pilot study.

    Science.gov (United States)

    Seifert, Kathrin; Spottke, Annika; Fliessbach, Klaus

    2017-11-01

    Art and art therapy open up interesting possibilities for dementia patients. However, it has not been evaluated scientifically so far, whether the art of sculpting has any benefits. In this non-randomized pilot study with twelve participants, we investigated the feasibility and acceptance of sculptural activity in patients with dementia and the effects on their well-being. A questionnaire was custom-designed to investigate five key aspects of well-being: mental state and concentration, corporeal memory, self-reliance, self-esteem and physicality. Remarkable improvements were seen in several subscales in the sculptural activity group, but not the control group: Mental state and concentration (nine of thirteen key aspects), self-reliance (four of five), self-esteem (one of one) and physicality (two of two). The results of this pilot study indicate the multidimensional effects of sculptural activity on patients living with dementia. The field would benefit greatly from further research.

  15. Henry Moore’s Public Sculpture in the US: The Collaborations with I. M. Pei

    Directory of Open Access Journals (Sweden)

    Alex Potts

    2016-07-01

    Full Text Available The many commissions Henry Moore received for public sculpture in the United States provided the occasion for several quite distinctive works. While not site specific, these were unique, and their final form, scale, and disposition was elaborated with a particular setting in mind. This aspect of Moore’s work in the US, which began with the monumental piece he designed for the Lincoln Center in New York in 1963–65, is examined here by focusing on the productive relationship he forged with the architect I. M. Pei in the 1970s. The sculptures Moore produced in collaboration with Pei respond in suggestive ways to the spatial environments created in American cities by late modern architectural developments. They also realize an oddly effective combination of the biomorphic and abstract that differs both from the bodily conception of Moore’s earlier work and the non-figurative character of much public sculpture of the time.

  16. A few words about the founder of the Macedonian modern sculpture

    Directory of Open Access Journals (Sweden)

    Marković Kamenko M.

    2016-01-01

    Full Text Available This paper discusses the life and work of Dima Todorovski, the founder of the Macedonian modern sculpture. Dimo Todorovski was born in Thessaloniki in 1910. He finished the Art School, the sculpture department, in Belgrade in 1935. He lived and worked in Skopje from 1942 until his death in 1983. During his career, he made an impressive number of sculptures among which are portraits, lovely female nudes, figures of men in motion, and other pieces related to the WWII. His best pieces include: The Portrait of the Artist's Mother, A Peasant Woman Portrait, The Pit, The Macedonian Pieta, A Girl, A monument in honour of Koco Racin, The Miladinov Brothers, St. Kliment Ohridski.

  17. Ice Cores

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Records of past temperature, precipitation, atmospheric trace gases, and other aspects of climate and environment derived from ice cores drilled on glaciers and ice...

  18. Ancient ice

    Science.gov (United States)

    2009-11-01

    Simon Belt, Guillaume Massé and colleagues rammed their way through sheets of ice, spotting some polar bears on the way, in their attempt to reconstruct Arctic sea-ice records covering thousands of years.

  19. Examinations of wooden sculptures from the altar of Veit Stoss in Cracow

    Energy Technology Data Exchange (ETDEWEB)

    Braziewicz, J. [Institute of Physics, Swietokrzyska, Academy in Kielce, Swietokrzyska 15, 25-406 Kielce (Poland)]. E-mail: janusz.braziewicz@pu.kielce.pl; Dudzik, R. [Institute of Physics, Swietokrzyska, Academy in Kielce, Swietokrzyska 15, 25-406 Kielce (Poland); JaskoIa, M. [The Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland); Kubala-Kukus, A. [Institute of Physics, Swietokrzyska, Academy in Kielce, Swietokrzyska 15, 25-406 Kielce (Poland); Kretschmer, W. [Physikalisches Institut, Universitaet Erlangen-Nuernberg, D-91058 Erlangen (Germany); Rutkowski, J. [Faculty of Conservation and Restoration of Works of Art, Academy of Fine Arts, 31-108 Cracow (Poland); Semaniak, J. [Institute of Physics, Swietokrzyska, Academy in Kielce, Swietokrzyska 15, 25-406 Kielce (Poland); Scharf, A. [Physikalisches Institut, Universitaet Erlangen-Nuernberg, D-91058 Erlangen (Germany); Stankiewicz, M. [Institute of Physics, Jagiellonian University, 30-059 Cracow (Poland); Uhl, T. [Physikalisches Institut, Universitaet Erlangen-Nuernberg, D-91058 Erlangen (Germany)

    2005-10-15

    The AMS facility at Erlangen University was used for dating samples from a wooden coping of the Veit Stoss's altar, one taken from its component originating from the 15th century and another one taken from its newer renovated part. The XRF method has been used to investigate trace element distribution inwards the sculptures. Concentrations of some elements, including Cl and Pb, show systematic increase while approaching the front or back side of the sculptures. The measured distributions are discussed in the context of history of the altar, in particular renovation and restoration procedures it underwent over the years.

  20. Examinations of wooden sculptures from the altar of Veit Stoss in Cracow

    International Nuclear Information System (INIS)

    Braziewicz, J.; Dudzik, R.; JaskoIa, M.; Kubala-Kukus, A.; Kretschmer, W.; Rutkowski, J.; Semaniak, J.; Scharf, A.; Stankiewicz, M.; Uhl, T.

    2005-01-01

    The AMS facility at Erlangen University was used for dating samples from a wooden coping of the Veit Stoss's altar, one taken from its component originating from the 15th century and another one taken from its newer renovated part. The XRF method has been used to investigate trace element distribution inwards the sculptures. Concentrations of some elements, including Cl and Pb, show systematic increase while approaching the front or back side of the sculptures. The measured distributions are discussed in the context of history of the altar, in particular renovation and restoration procedures it underwent over the years

  1. Politics of Participation in Benoît Maubrey’s Speaker Sculptures

    DEFF Research Database (Denmark)

    Keylin, Vadim

    Speaker Sculptures is a series of works by Benoît Maubrey, created in 1983-2015. All of them are large-scale architecture-like constructions (often modelled after existing historical buildings or building types) built of recycled loudspeakers. The public could connect to the work by calling...... Sculptures connect the public space to the electronic media, subverting their antagonism and creating a single space of social interactions. This offers a possibility of political presence in public space to those, who are unable to do so in person due to physical or mental disabilities, or other personal...

  2. SMALL ARCHITECTURAL AND SCULPTURAL FORMS ARE IN DESIGN OF INTERIORS OF AIR TERMINALS

    Directory of Open Access Journals (Sweden)

    B.А. Зеленкова

    2012-10-01

    Full Text Available  Determination of small forms is considered in architecture and in a sculpture. Certainly difference between national and international style in a design. Their use is considered in the design of interiors of passenger spaces of air terminals on existent examples. Connection is analysed between architectural small forms and by the sculpture of small forms, which consists in the transmission of the general semantic and aesthetically beautiful loading on a man, namely to create feeling of comfort, national self-esteem, national pride, and but to consciousness

  3. The history of the "Virgin with Child" sculpture (Ottaviano, Naples, southern Italy)

    DEFF Research Database (Denmark)

    Balassone, Giuseppina; Toscano, Maria; Cavazzini, Giancarlo

    2014-01-01

    historical context. Historical documents testify that the sculpture was a property of the cadet branch of noble Tuscan family of the Medici, the Medici of Ottaviano. A multianalytical approach has been used to try to indicate the supply area of the white marble of the studied sculpture. Considering the whole......A life-size whitish marble statue of a "Virgin with Child" has been recently rediscovered in the St.Rosario church located in Ottaviano, a small town near Naples (southern Italy). This artwork shows stylistic features of the Tuscan-Roman school of the 16th century, and is framed in an intriguing...

  4. Ice Cream

    NARCIS (Netherlands)

    Scholten, E.

    2014-01-01

    Ice cream is a popular dessert, which owes its sensorial properties (mouth feel) to its complex microstructure. The microstructure is a result of the combination of the ingredients and the production process. Ice cream is produced by simultaneous freezing and shearing of the ice cream mix, which

  5. Acid rain attack on outdoor sculpture in perspective

    Science.gov (United States)

    Livingston, Richard A.

    2016-12-01

    A major concern motivating research in acid rain materials effects has been the potential for damage to cultural heritage, particularly outdoor marble and bronze sculpture. However, a combination of field and laboratory studies has failed to show a correlation between rain pH and loss of materials. In order to understand this counterintuitive lack of acid rain effect, an aqueous geochemical modeling approach was used to analyze rain runoff chemistry for the relative importance of acid rain neutralization, dry deposition, and in the case of marble, natural carbonate dissolution. This approach involved the development of pH - SO42- phase diagrams for marble (calcium carbonate) and bronze (copper) under ambient environmental conditions. This then enabled reaction path modeling of the acid neutralization process using the pH range typically found in wet deposition (3.5-6). The results were for marble that the theoretical maximum amount of Ca2+ ion that could be lost due acid rain neutralization would be 0.158 mmol/l compared to 10.5 mmol/l by dry deposition, and for bronze, the Cu2+ ion losses would be 0.21 mmol/l and 47.3 mmol/l respectively. Consequently dry deposition effects on these materials have the potential to dominate over wet deposition effects. To test these predictions the geochemical models were applied to examples of data sets from mass balance (runoff vs rainfall) studies on a marble statue in New York City and some bronze memorial plaques at Gettysburg PA. Although these data sets were collected in the early 1980s they remain valid for demonstrating the mass balance method. For the marble statue, the mean Ca2+ losses by dry deposition was about 69% of the total compared 0.3% for acid rain neutralization, which was less than the natural carbonate dissolution losses of 0.8%. For the bronze, the mean Cu2+ losses were 70.6% by SO42- dry deposition and 23% by NO3- dry deposition compared to 6.4% by acid rain neutralization. Thus for both cases the wet

  6. Legal Ice?

    DEFF Research Database (Denmark)

    Strandsbjerg, Jeppe

    The idealised land|water dichotomy is most obviously challenged by ice when ‘land practice’ takes place on ice or when ‘maritime practice’ is obstructed by ice. Both instances represent disparity between the legal codification of space and its social practice. Logically, then, both instances call...... for alternative legal thought and practice; in the following I will emphasise the former and reflect upon the relationship between ice, law and politics. Prior to this workshop I had worked more on the relationship between cartography, geography and boundaries than specifically on ice. Listening to all...

  7. Study of Italian Renaissance sculptures using an external beam nuclear microprobe

    International Nuclear Information System (INIS)

    Zucchiatti, A.; Bouquillon, A.; Moignard, B.; Salomon, J.; Gaborit, J.R.

    2000-01-01

    The use of an extracted proton micro-beam for the PIXE analysis of glazes is discussed in the context of the growing interest in the creation of an analytical database on Italian Renaissance glazed terracotta sculptures. Some results concerning the frieze of an altarpiece of the Louvre museum, featuring white angels and cherubs heads, are presented

  8. From Postmodernism to Milk Cartons: Junk Art Sculptures and Pre-Service Teachers' Philosophies of Schooling

    Science.gov (United States)

    McDermott, Morna

    2008-01-01

    This essay focuses of an arts-informed inquiry performed by sixteen pre-service teachers who created sculptures to explore their teaching philosophies. Through this creative process changes occurred in their assumptions and expectations about what is of value in teaching and relationships between themselves, their students, and the community. The…

  9. Stereoscan electron microscope observations on opisthobranch radulae and shell-sculpture

    NARCIS (Netherlands)

    Thompson, T.E.; Hinton, H.E.

    1968-01-01

    Traditional methods of observation applied to the sculpture of tectibranch shells and to the radulae of gastropods in general, have yielded a great deal of information regarding the structure of these organs, which are so important in taxonomy. In the genus Philine, for instance, the numerous

  10. Dress Fashion in Feminist and Child Rights Campaigns in Ghanaian Public Sculptures of the 1990s

    Science.gov (United States)

    Essel, Osuanyi Quaicoo; Opoku-Mensah, Isaac

    2017-01-01

    This article examines how dress fashion in outdoor sculptures of the 1990s in the Accra cityscape accentuated feminist activism, sensitised child right campaigns, and encouraged girl-child education in support of governmental efforts and activism of civil society organisations in Ghana. It gives attention to how dress fashion of the time was used…

  11. Nature and sculpture in the creation of African theatre scenery | Iwuh ...

    African Journals Online (AJOL)

    The meaning of space is defined by the images contained in that space. Creating scenery for the theatre as an indoor activity involves either the creation of imaginary forms or the replication of existing images around the creator's environment. These imported items include natural vegetation, architecture, sculpture and ...

  12. Chronologies in wood and resin: AMS 14C dating of pre-Hispanic Caribbean Wood Sculpture

    Science.gov (United States)

    Joanna Ostapkowicz; Christopher Bronk-Ramsey; Fiona Brock; Tom Higham; Alex C. Wiedenhoeft; Erika Ribechini; Jeannette J. Lucejko; Samuel. Wilson

    2012-01-01

    This paper establishes a chronological framework for selected pieces of Caribbean (Tafno/Lucayan) wooden sculpture, enabling previously ahistoric artefacts to fit back into the wider corpus of pre-colonial material culture. Seventy-two 14C AMS determinations from 56 artefacts held in museum collections are reported, including 32 ceremonial

  13. A likely cranial osteodystrophy (Paget's disease of bone) in a Precolumbian, Mesoamerican stone sculpture.

    Science.gov (United States)

    Toni, R; Ceglia, L

    2017-07-01

    This short note illustrates facial and head features found in a stone sculpture of the ancient, Precolumbian period in a temple of the Mayan city of Copan (Honduras). The authors believe that this observation may support paleoanthropological evidence of Paget's disease of bone, an osteodystrophy described in the Mesoamerican Indian populations before the first millennium A.D.

  14. Three-Dimensional Interpretation of Sculptural Heritage with Digital and Tangible 3D Printed Replicas

    Science.gov (United States)

    Saorin, José Luis; Carbonell-Carrera, Carlos; Cantero, Jorge de la Torre; Meier, Cecile; Aleman, Drago Diaz

    2017-01-01

    Spatial interpretation features as a skill to acquire in the educational curricula. The visualization and interpretation of three-dimensional objects in tactile devices and the possibility of digital manufacturing with 3D printers, offers an opportunity to include replicas of sculptures in teaching and, thus, facilitate the 3D interpretation of…

  15. Analysis of the body mass index and leg profiles of Asian women after total leg sculpture.

    Science.gov (United States)

    Tsai, Feng-Chou; Chen, Chien-Hao; Lin, Chan-Yi; Ho, Li-Yung

    2009-08-01

    In addition to the conventional methods used to improve leg contours, total leg sculpture, including liposuction, selective neurectomy, and transilluminated powered phlebectomy, provides a one-time solution of leg contour problems, which is a major aesthetic concern among Asian women. The authors present the postoperative results of total leg sculpture and determine any significance and correlation between the leg variables and body mass index by statistical analysis. Thirty female patients who underwent total leg sculpture between 2005 and 2008 were included in the study, and prospective analysis of the patients' data was performed during a follow-up period of 1 year. Local measurement variables and body mass index were recorded, and the correlation between them was determined by Pearson's correlation and regression analysis. A paired t test was used to compare the postoperative outcomes. Subjectively, all patient results were satisfactory. There were significant differences between preoperative and postoperative measurements for all variables for total leg sculpture. Body mass index was strongly correlated with all leg indexes, and there was a significant positive correlation between the index and variables related to the buttocks and upper thigh. The satisfactory postoperative leg variables were buttocks circumference (87.85 cm), thigh circumference (T60, 44.20 cm), maximal calf circumference (32.24 cm), and calf ratio (0.78). Each preoperative body mass index increment represents a 0.3 percent circumference improvement around the buttocks after surgery. No obvious morbidities or long-term hospital stays were noted. Total leg sculpture provides a combined aesthetic solution for improving limb contours with minimal morbidity. Patients with larger body mass index values exhibit better aesthetic improvement than those with smaller values.

  16. Roman period portrait habit in the funerary sculpture of northern Jordan: Local and foreign influences and their implications

    DEFF Research Database (Denmark)

    Lichtenberger, Achim; Raja, Rubina

    Funerary portraiture in the Near East has become a topic of discussion in the last years’ of scholarship once again. However, the funerary sculpture of Northern Jordan has received little attention in this connection. There are several reasons for that. For one the sculpture, often in the shape...... of funerary busts, are not of what we perceive as a high quality and secondly it has not been collected in a corpus and thirdly a strict typology and chronology of the sculpture does not exist. Nonetheless this portraiture, which it was, no matter the quality, deserves attention as a group of its own...

  17. Sea Ice

    Science.gov (United States)

    Perovich, D.; Gerland, S.; Hendricks, S.; Meier, Walter N.; Nicolaus, M.; Richter-Menge, J.; Tschudi, M.

    2013-01-01

    During 2013, Arctic sea ice extent remained well below normal, but the September 2013 minimum extent was substantially higher than the record-breaking minimum in 2012. Nonetheless, the minimum was still much lower than normal and the long-term trend Arctic September extent is -13.7 per decade relative to the 1981-2010 average. The less extreme conditions this year compared to 2012 were due to cooler temperatures and wind patterns that favored retention of ice through the summer. Sea ice thickness and volume remained near record-low levels, though indications are of slightly thicker ice compared to the record low of 2012.

  18. Ice Surfaces

    Science.gov (United States)

    Shultz, Mary Jane

    2017-05-01

    Ice is a fundamental solid with important environmental, biological, geological, and extraterrestrial impact. The stable form of ice at atmospheric pressure is hexagonal ice, Ih. Despite its prevalence, Ih remains an enigmatic solid, in part due to challenges in preparing samples for fundamental studies. Surfaces of ice present even greater challenges. Recently developed methods for preparation of large single-crystal samples make it possible to reproducibly prepare any chosen face to address numerous fundamental questions. This review describes preparation methods along with results that firmly establish the connection between the macroscopic structure (observed in snowflakes, microcrystallites, or etch pits) and the molecular-level configuration (detected with X-ray or electron scattering techniques). Selected results of probing interactions at the ice surface, including growth from the melt, surface vibrations, and characterization of the quasi-liquid layer, are discussed.

  19. From Soft Sculpture to Soft Robotics: Retracing a Physical Aesthetics of Bio-Morphic Softness

    DEFF Research Database (Denmark)

    Jørgensen, Jonas

    2017-01-01

    the soft sculpture that started proliferating in the late 1960s. Critical descriptions of these works, interestingly, frequently emphasize their similarities with living organisms and bodies as a central tenet of their aesthetics. The paper seeks to articulate aspects of a contiguity between softness...... science. Recently, soft robotics technology has also started to make its way into art, design, and architecture. This paper attempts to think an aesthetics of softness and the life-like through an artistic tradition deeply imbricated with an interrogation of softness and its physical substrates, namely...... and the life-like in these works through readings that draw on concepts from technical soft robotics research and the description of life in physics (via entropy). It is argued, that fractions of soft sculpture anticipate central interests and notions present in contemporary technical soft robotics research....

  20. Glancing angle deposition of sculptured thin metal films at room temperature

    Science.gov (United States)

    Liedtke, S.; Grüner, Ch; Lotnyk, A.; Rauschenbach, B.

    2017-09-01

    Metallic thin films consisting of separated nanostructures are fabricated by evaporative glancing angle deposition at room temperature. The columnar microstructure of the Ti and Cr columns is investigated by high resolution transmission electron microscopy and selective area electron diffraction. The morphology of the sculptured metallic films is studied by scanning electron microscopy. It is found that tilted Ti and Cr columns grow with a single crystalline morphology, while upright Cr columns are polycrystalline. Further, the influence of continuous substrate rotation on the shaping of Al, Ti, Cr and Mo nanostructures is studied with view to surface diffusion and the shadowing effect. It is observed that sculptured metallic thin films deposited without substrate rotation grow faster compared to those grown with continuous substrate rotation. A theoretical model is provided to describe this effect.

  1. High Rise Building: The Mega Sculpture Made Of Steel, Concrete and Glass

    Science.gov (United States)

    Stefańska, Alicja; Załuski, Daniel

    2017-10-01

    High rise building has transformed from providing not only the expansion of floor space but functioning as mega sculpture in the city. The shift away from economic efficiency driven need is only expected to grow in the future. Based on literature studies; after analysing planning documents and case studies, it was examined whether the presumption that gaining the maximum amount of usable area is the only driving factor; or if the need for the creation of an image for the city provided a supplementary reason. The results showed that forming high rise buildings as three-dimensional sculptures is influenced not only by aesthetics, but also marketing. Visual distinction in the city skyline is economically beneficial for investors gaining not only functionality but art, enriching the cultural landscape. Organizing architectural competitions, public debates and following the latest art trends is therefore possible due to large budgets of such projects.

  2. Legal Ice?

    DEFF Research Database (Denmark)

    Strandsbjerg, Jeppe

    for alternative legal thought and practice; in the following I will emphasise the former and reflect upon the relationship between ice, law and politics. Prior to this workshop I had worked more on the relationship between cartography, geography and boundaries than specifically on ice. Listening to all...... the interesting conversations during the workshop, however, made me think that much of the concern with the Polar Regions in general, and the presence of ice in particular, reverberates around the question of how to accommodate various geographical presences and practices within the regulatory framework that we...

  3. PIXE and μ-PIXE analysis of glazes from terracotta sculptures of the della Robbia workshop

    International Nuclear Information System (INIS)

    Zucchiatti, Alessandro; Bouquillon, Anne; Lanterna, Giancarlo; Franco, Lucarelli; Mando, Pier Andrea; Prati, Paolo; Salomon, Joseph; Vaccari, Maria Grazia

    2002-01-01

    A series of PIXE analyses has been performed on glazes from terracotta sculptures of the Italian Renaissance and on reference standards. The problems related to the investigation of such heterogeneous materials are discussed and the experimental uncertainties are evaluated, for each element, from the PIXE analysis of standard glasses. Some examples from artefacts coming from Italian collections are given. This research has been conducted in the framework of the COST-G1 European action

  4. Local Treatment for Monochrome Outdoor Painted Metal Sculptures: Assessing the suitability of conservation paints for retouching

    OpenAIRE

    van Basten, Nikki; Defeyt, Catherine; Rivenc, Rachel

    2015-01-01

    When outdoor painted sculptures get chipped, scratched or abraded, conservators might consider local retouching treatments as an option that would protect the exposed metal substrate and restore the aesthetic integrity, thus postponing a very costly and invasive overall repainting. Unfortunately, matching colour gloss and texture on large monochrome surfaces is always challenging. This paper reports on research undertaken to investigate some of the materials and application techniques that co...

  5. Visiting Richard Serra's "Promenade" sculpture improves postural control and judgment of subjective visual vertical.

    Science.gov (United States)

    Kapoula, Zoï; Lang, Alexandre; Lê, Thanh-Thuan; Adenis, Marie-Sarah; Yang, Qing; Lipede, Gabi; Vernet, Marine

    2014-01-01

    Body sway while maintaining an upright quiet stance reflects an active process of balance based on the integration of visual, vestibular, somatosensory, and proprioceptive inputs. Richard Serra's Promenade sculpture featured in the 2008 Monumenta exhibition at the Grand Palais in Paris, France is herein hypothesized to have stimulated the body's vertical and longitudinal axes as it showcased five monumental rectangular solids pitched at a 1.69(°) angle. Using computerized dynamic posturography we measured the body sway of 23 visitors when fixating a cross, or when observing the artwork (fixating it or actively exploring it with eye movements) before and after walking around and alongside the sculpture (i.e., before and after a promenade). A first fixation at the sculpture increased medio-lateral stability (in terms of spectral power of body sway). Eye movement exploration in the depth of the sculpture increased antero-posterior stability [in terms of spectral power and canceling time (CT) of body sway] at the expense of medio-lateral stability (in terms of CT). Moreover, a medio-lateral instability associated with eye movement exploration before the promenade (in terms of body sway sensu stricto) was canceled after the promenade. Finally, the overall medio-lateral stability (in terms of spectral power) increased after the promenade. Fourteen additional visitors were asked to stand in a dark room and adjust a luminous line to what they considered to be the earth-vertical axis. The promenade executed within the sculpted environment afforded by Serra's monumental statuary works resulted in significantly improved performances on the subjective visual vertical test. We attribute these effects to the sculpted environment provided by the exhibition which may have acted as a kind of physiologic "training ground" thereby improving the visitors' overall sense of visual perspective, equilibrium, and gravity.

  6. Visiting Richard Serra’s Promenade sculpture improves postural control and judgment of subjective visual vertical.

    Directory of Open Access Journals (Sweden)

    Zoï eKapoula

    2014-12-01

    Full Text Available Body sway while maintaining an upright quiet stance reflects an active process of balance based on the integration of visual, vestibular, somatosensory and proprioceptive inputs. Richard Serra’s Promenade sculpture featured in the 2008 Monumenta exhibition at the Grand Palais in Paris, France is herein hypothesised to have stimulated the body’s vertical and longitudinal axes as it showcased 5 monumental rectangular solids pitched at a 1.69° angle.Using computerised dynamic posturography we measured the body sway of 23 visitors when fixating a cross, or when observing the artwork (fixating it or actively exploring it with eye movements before and after walking around and alongside the sculpture (i.e., before and after a promenade. A first fixation at the sculpture increased medio-lateral stability (in terms of spectral power of body sway. Eye movement exploration in the depth of the sculpture increased antero-posterior stability (in terms of spectral power and cancelling time of body sway at the expense of medio-lateral stability (in terms of cancelling time. Moreover, a medio-lateral instability associated with eye movement exploration before the promenade (in terms of body sway sensu stricto was cancelled after the promenade. Finally, the overall medio-lateral stability (in terms of spectral power increased after the promenade.Fourteen additional visitors were asked to sit in a dark room and adjust a luminous line to what they considered to be the earth-vertical axis. The promenade executed within the sculpted environment afforded by Serra’s monumental statuary works resulted in significantly improved performances on the subjective visual vertical test.We attribute these effects to the sculpted environment provided by the exhibition which may have acted as a kind of physiologic training ground thereby improving the visitors’ overall sense of visual perspective, equilibrium and gravity.

  7. Wildlife art and illustration: stone sculpture and painting - some experiments in Auroville, Tamil Nadu, India

    Directory of Open Access Journals (Sweden)

    M.E. Ramanujam

    2014-09-01

    Full Text Available The métier of combining granite stone carving with painting of wildlife subjects in Pitchandikulam at Auroville International Township has been rather innovative, and some works are described and analyzed. The basic history of stone carving, and especially of those sculptures with animal motifs, is recounted, and the applications, especially in the context of enhancing landscape architecture, are discussed and highlighted.

  8. The microbial community characteristics of ancient painted sculptures in Maijishan Grottoes, China.

    Science.gov (United States)

    Duan, Yulong; Wu, Fasi; Wang, Wanfu; He, Dongpeng; Gu, Ji-Dong; Feng, Huyuan; Chen, Tuo; Liu, Guangxiu; An, Lizhe

    2017-01-01

    In this study, a culture-independent Illumina MiSeq sequencing strategy was applied to investigate the microbial communities colonizing the ancient painted sculptures of the Maijishan Grottoes, a famous World Cultural Heritage site listed by UNESCO in China. Four mixed samples were collected from Cave 4-4 of the Maijishan Grottoes, the so-called Upper Seven Buddha Pavilion, which was built during the Northern Zhou Dynasty (557-581AD). The 16/18S rRNA gene-based sequences revealed a rich bacterial diversity and a relatively low fungal abundance, including the bacterial groups Actinobacteria, Acidobacteria, Bacteroidetes, Cyanobacteria, Chloroflexi, Firmicutes, Proteobacteria and Verrucomicrobia and the fungal groups Ascomycota, Basidiomycota and Chytridiomycota. Among them, the bacteria genera of Pseudonocardia and Rubrobacter and unclassified fungi in the order of Capnodiales were dominant. The relative abundance of Pseudonocardia in the painted layer samples was higher than that in the dust sample, while Cyanobacteria dominated in the dust sample. Many of them have been discovered at other cultural heritage sites and associated with the biodeterioration of cultural relics. The presence and activity of these pioneering microorganisms may lead to an unexpected deterioration of the painted sculptures that are preserved in this heritage site. Thus, proper management strategies and potential risk monitoring should be used in the Maijishan Grottoes to improve the conservation of these precious painted sculptures.

  9. Photographs of Sculpture: Greek Slave’s ‘complex polyphony’, 1847–77

    Directory of Open Access Journals (Sweden)

    Patrizia Di Bello

    2016-06-01

    Full Text Available This article explores some of the representations, iterations, and appearances of Hiram Powers’s 'Greek Slave' in London in the decades after its first exhibition in 1845, years in which a variety of new ‘engines of the fine arts’ were fuelling a widening market for art objects of all kinds, and popular culture could turn statues into celebrities appearing everywhere — exhibitions, photographers’ studios, newspapers, 'tableau-vivant' shows, even confectionery shops. The article’s focus is on how sculpture was used in the reception and understanding of photography as a new medium of reproduction, and how the materiality of specific photographic ‘objects’ — daguerreotypes, paper prints, and stereographs — interacted with that of sculpture to affect the viewer, at a time when sculptural objects themselves blurred the boundaries between original and reproduction. The article ends with an analysis of stereoscopic cards of 'Greek Slave', as the first photographic reproductions that could really compete with wood engravings and statuettes in the dissemination and circulation of statues, arguing for their pleasurable interactivity as key to their success.

  10. 3D Reconstruction and Restoration Monitoring of Sculptural Artworks by a Multi-Sensor Framework

    Directory of Open Access Journals (Sweden)

    Sandro Barone

    2012-12-01

    Full Text Available Nowadays, optical sensors are used to digitize sculptural artworks by exploiting various contactless technologies. Cultural Heritage applications may concern 3D reconstructions of sculptural shapes distinguished by small details distributed over large surfaces. These applications require robust multi-view procedures based on aligning several high resolution 3D measurements. In this paper, the integration of a 3D structured light scanner and a stereo photogrammetric sensor is proposed with the aim of reliably reconstructing large free form artworks. The structured light scanner provides high resolution range maps captured from different views. The stereo photogrammetric sensor measures the spatial location of each view by tracking a marker frame integral to the optical scanner. This procedure allows the computation of the rotation-translation matrix to transpose the range maps from local view coordinate systems to a unique global reference system defined by the stereo photogrammetric sensor. The artwork reconstructions can be further augmented by referring metadata related to restoration processes. In this paper, a methodology has been developed to map metadata to 3D models by capturing spatial references using a passive stereo-photogrammetric sensor. The multi-sensor framework has been experienced through the 3D reconstruction of a Statue of Hope located at the English Cemetery in Florence. This sculptural artwork has been a severe test due to the non-cooperative environment and the complex shape features distributed over a large surface.

  11. DOUBLE BOSS SCULPTURED DIAPHRAGM EMPLOYED PIEZORESISTIVE MEMS PRESSURE SENSOR WITH SILICON-ON-INSULATOR (SOI

    Directory of Open Access Journals (Sweden)

    D. SINDHANAISELVI

    2017-07-01

    Full Text Available This paper presents the detailed study on the measurement of low pressure sensor using double boss sculptured diaphragm of piezoresistive type with MEMS technology in flash flood level measurement. The MEMS based very thin diaphragms to sense the low pressure is analyzed by introducing supports to achieve linearity. The simulation results obtained from Intellisuite MEMS CAD design tool show that very thin diaphragms with rigid centre or boss give acceptable linearity. Further investigations on very thin diaphragms embedded with piezoresistor for low pressure measurement show that it is essential to analyse the piezoresistor placement and size of piezoresistor to achieve good sensitivity. A modified analytical modelling developed in this study for double boss sculptured diaphragm results were compared with simulated results. Further the enhancement of sensitivity is analyzed using non uniform thickness diaphragm and Silicon-On-Insulator (SOI technique. The simulation results indicate that the double boss square sculptured diaphragm with SOI layer using 0.85μm thickness yields the higher voltage sensitivity, acceptable linearity with Small Scale Deflection.

  12. Comparing Compositions of Modern Cast Bronze Sculptures: Optical Emission Spectroscopy Versus x-Ray Fluorescence Spectroscopy

    Science.gov (United States)

    Young, M. L.; Dunand, D. C.

    2015-07-01

    Bulk elemental compositions of 74 modern cast bronze sculptures from the collection at the Art Institute of Chicago, the Philadelphia Museum of Art, and the Rodin Museum (Philadelphia, PA) were determined using inductively coupled plasma-optical emission spectroscopy (ICP-OES) and a handheld x-ray fluorescence (XRF) spectrometer. The elemental compositions of the cast sculptures as measured previously by ICP-OES and presently by XRF are compared: A good match is found between the two methods for the base metal (Cu) and the two majority alloying elements (Zn and Sn). For both ICP-OES and XRF data, when the Zn composition is plotted versus the Sn composition, three discernable clusters are found that are related to the artist, foundry, casting date, and casting method; they consist of (A) high-zinc brass, (B) low-zinc, low-tin brass, and (C) low-zinc, tin bronze. Thus, our study confirms that the relatively fast, nondestructive XRF spectrometry can be used effectively over slower and invasive, but more accurate, ICP-OES to help determine a sculpture's artist, foundry, date of creation, date of casting, and casting method.

  13. Micro-analytical study of a rare papier-mâché sculpture.

    Science.gov (United States)

    Manso, Marta; Bidarra, Ana; Longelin, Stéphane; Pessanha, Sofia; Ferreira, Adriana; Guerra, Mauro; Coroado, João; Carvalho, Luísa

    2015-02-01

    The analysis of a Portuguese "papier-mâché" sculpture depicting Saint Anthony is presented in this case study. Several questions were addressed such as the characteristics of the support, pigments used, and artistic technique in order to establish a possible timeline for its production. Qualitative analyses of the cross-sections and of the paper support were performed by optical microscopy using reflected light. Two polychrome layers from different periods and a rag pulped support were identified on the sculpture. The use of micro X-ray fluorescence and Raman microscopy techniques enabled the differentiation of coloring materials used in both polychromies. Semi-quantitative analyses of the gilded samples were also performed by scanning electron microscopy in combination with energy-dispersive spectroscopy allowing the determination of a common Au-Ag-Cu alloy with differences in the purity of the gold. The identified coloring materials lead us to believe that the sculpture was produced in the 19th century, being overpainted in the first half of the 20th century.

  14. "Lesbians are not women": feminine and lesbian sensibilities in Harmony Hammond's late-1970s sculpture.

    Science.gov (United States)

    Thompson, Margo Hobbs

    2008-01-01

    Harmony Hammond's wrapped fabric sculptures are placed in context of the theories of gender and sexuality that circulated among lesbian and straight feminists at the time they were made, the late 1970s. Hammond has cited in particular Monique Wittig's novels, such as The Lesbian Body, and her essays including "The Straight Mind" where Wittig concludes that the lesbian is not a woman. The critique to which Wittig's lesbian separatism has been subjected by Judith Butler in her consideration of the appeal and limitations of essentialism also applies to Hammond's art. Hammond's use of vaginal imagery was instrumental to visualizing a lesbian sensibility, but the proposition of such a sensibility established a new problematic: a new essential category. The article concludes that because Hammond's work was produced in the context of a complex set of discourses, lesbian, feminist, and aesthetic, it resisted reduction to a singular meaning. Her sculptures avoided the pitfall of substituting one essence for another, lesbian for feminine sensibility, but activated both. The sculptures effectively queered vaginal imagery: When Hammond used vaginal imagery to represent lesbian sensibility, she subverted the equation of sex and gender and the essentialist notion of feminine sensibility.

  15. Pride and memory: perceptions of individuality in Iberian sculpture around 1400

    Directory of Open Access Journals (Sweden)

    Javier Martínez de Aguirre

    2017-12-01

    Full Text Available In the Iberian kingdoms of Castile-Leon and Navarre, the development of individualized sculptural representations at the beginning of fifteenth-century was directly conditioned by the interest of patrons. Castilian kings and many nobles of the most powerful lineages gave no importance to the commissioning of funerary statues. On the other hand, King Charles the Noble of Navarre and some prelates and nobles, raised to the highest positions because of their services to the monarchs, felt more attracted by the idea of leaving a memory including their physical appearance. The depiction of physical likeness depended, secondly, on the training and ability of the artists, as well as on the existence or not of the sitter at the time the work was executed. In Navarra, sculptural fidelity to facial features enjoyed wide acceptance, while the contemporary literature showed no signs of interest in these personality traits. In Castile, however, writers of classical training had provided physical descriptions of the main characters in history since the 14th century, while sculptural depiction of individualized features came later.

  16. Archaeometric characterization and provenance determination of sculptures and architectural elements from Gerasa, Jordan

    Science.gov (United States)

    Al-Bashaireh, Khaled

    2018-02-01

    This study aims at the identification of the provenance of white marble sculptures and architectural elements uncovered from the archaeological site of Gerasa and neighboring areas, north Jordan. Most of the marbles are probably of the Roman or Byzantine periods. Optical microscopy, X-ray diffraction, and mass spectrometry were used to investigate petrographic, mineralogical and isotopic characteristics of the samples, respectively. Analytical results were compared with the main reference databases of known Mediterranean marble quarries exploited in antiquity. The collected data show that the most likely main sources of the sculptures were the Greek marble quarries of Paros-2 (Lakkoi), Penteli (Mount Pentelikon, Attica), and Thasos-3 (Thasos Island, Cape Vathy, Aliki); the Asia Minor marble quarries of Proconessus-1 (Marmara) and Aphrodisias (Aphrodisias); and the Italian quarry of Carrara (Apuan Alps). Similarly, the Asia Minor quarries of the fine-grained Docimium (Afyon) and the coarse-grained Proconessus-1 (Marmara) and Thasos-3 are the most likely sources of the architectural elements. The results agree with published data on the wide use of these marbles for sculpture and architectural elements.

  17. Toward a new concept of the "cultural elite state": Cultural capital and the urban sculpture planning authority in elite coalition in Shanghai

    OpenAIRE

    Zheng, Jane

    2016-01-01

    The emergence of an attractive public art scene in urban public areas (termed urban sculpture in the Chinese context) is a recent phenomenon in Shanghai. The role of the local state in urban sculpture planning and development has not been critically examined. This article proposes a model entitled "cultural elite state" to conceptualize the characteristics of urban sculpture authority. The main argument is that the cultural capital held by individual political and social eli...

  18. A spongy icing model for aircraft icing

    Directory of Open Access Journals (Sweden)

    Li Xin

    2014-02-01

    Full Text Available Researches have indicated that impinging droplets can be entrapped as liquid in the ice matrix and the temperature of accreting ice surface is below the freezing point. When liquid entrapment by ice matrix happens, this kind of ice is called spongy ice. A new spongy icing model for the ice accretion problem on airfoil or aircraft has been developed to account for entrapped liquid within accreted ice and to improve the determination of the surface temperature when entering clouds with supercooled droplets. Different with conventional icing model, this model identifies icing conditions in four regimes: rime, spongy without water film, spongy with water film and glaze. By using the Eulerian method based on two-phase flow theory, the impinging droplet flow was investigated numerically. The accuracy of the Eulerian method for computing the water collection efficiency was assessed, and icing shapes and surface temperature distributions predicted with this spongy icing model agree with experimental results well.

  19. The Materials and Techniques of Polychrome Baroque Wooden Sculpture: Three Works From Baião, Portugal

    Directory of Open Access Journals (Sweden)

    C. Barata

    2010-03-01

    Full Text Available Three polychrome wooden sculptures, made between the last quarter of the 17th century and the first half of the 18th century, from a monastery in Northern Portugal, representing an episode of the Passion of Christ, were analysed with three aims: to identify the materials and techniques employed; to clarify the relationship between the three sculptures; to reveal previous restorations. Techniques such as radiography, energy dispersive X-ray spectrometry, optical and polarized light microscopy and Fourier Transform infrared spectroscopy were employed. White lead, vermillion, umber, carbon black, gypsum, anhydride and chalk were identified as pigments and fillers. These materials and the layer structure led to the conclusion that sculptures 1 and 2 were treated as a pair of sculptures and that they underwent at least two restorations: the first was probably done in the workshop where they were made. During the second restoration, the heads were replaced. Sculpture 3 is not restored and its poorer style seems to have correspondence to materials of lower quality.

  20. The great beauty: a neuroaesthetic study by neuroelectric imaging during the observation of the real Michelangelo's Moses sculpture.

    Science.gov (United States)

    Babiloni, F; Cherubino, P; Graziani, I; Trettel, A; Bagordo, G M; Cundari, C; Borghini, G; Arico, P; Maglione, A G; Vecchiato, G

    2014-01-01

    Recent studies have been showed as the perception of real or displayed masterpieces by ancient or modern painters generate stable neuroelectrical correlates in humans. In this study, we collected the neuroelectrical brain activity correlated with the observation of the real sculpture of Michelangelo's Moses within the church where it is actually installed in a group of healthy subjects. In addition to the cerebral activity also the heart rate (HR) and the galvanic skin response (GSR) were collected simultaneously, to assess the emotional engage of the investigated population. The Moses sculpture was observed by the group from three different point of views, each one revealing different details of the sculpture. In addition, in each location the light conditions related to the specific observation of the sculpture were explicitly changed. Results showed that cerebral activity of the subjects varied significantly across the three different views and for light condition against no light condition (psculpture could be easily grab by the eyes. Results suggested how the perception of the sculpture depends critically by the point of view of the observers and how such point of view can produce separate emotional and cerebral responses.

  1. Soluble salt sources in medieval porous limestone sculptures: A multi-isotope (N, O, S) approach

    Energy Technology Data Exchange (ETDEWEB)

    Kloppmann, W., E-mail: w.kloppmann@brgm.fr [BRGM, Direction des Laboratoires, Unité Isotopes, BP 6009, F-45060 Orléans cedex 2 (France); Rolland, O., E-mail: olivierrolland@wanadoo.fr [Montlouis-sur-Loire (France); Proust, E.; Montech, A.T. [BRGM, Direction des Laboratoires, Unité Isotopes, BP 6009, F-45060 Orléans cedex 2 (France)

    2014-02-01

    The sources and mechanisms of soluble salt uptake by porous limestone and the associated degradation patterns were investigated for the life-sized 15th century “entombment of Christ” sculpture group located in Pont-à-Mousson, France, using a multi-isotope approach on sulphates (δ{sup 34}S and δ{sup 18}O) and nitrates (δ{sup 15}N and δ{sup 18}O). The sculpture group, near the border of the Moselle River, is within the potential reach of capillary rise from the alluvial aquifer. Chemical analyses show a vertical zonation of soluble salts with a predominance of sulphates in the lower parts of the statues where crumbling and blistering prevail, and higher concentrations of nitrates and chloride in the high parts affected by powdering and efflorescence. Isotope fingerprints of sulphates suggest a triple origin: (1) the lower parts are dominated by capillary rise of dissolved sulphate from the Moselle water with characteristic Keuper evaporite signatures that progressively decreases with height; (2) in the higher parts affected by powdering the impact of atmospheric sulphur becomes detectable; and (3) locally, plaster reparations impact the neighbouring limestone through dissolution and re-precipitation of gypsum. Nitrogen and oxygen isotopes suggest an organic origin of nitrates in all samples. N isotope signatures are compatible with those measured in the alluvial aquifer of the Moselle River further downstream. This indicates contamination by sewage or organic fertilisers. Significant isotopic contrasts are observed between the different degradation features depending on the height and suggest historical changes of nitrate sources. - Highlights: • We use S, N and O isotopes to distinguish salt sources in limestone sculptures. • Vertical zonation of degradation is linked to capillary rise and air pollution. • Sulphate salts in lower parts are derived from river/groundwater. • Sulphate salts in higher parts show signature of air pollution. • Nitrates

  2. Nondestructive insights into composition of the sculpture of Egyptian Queen Nefertiti with CT.

    Science.gov (United States)

    Huppertz, Alexander; Wildung, Dietrich; Kemp, Barry J; Nentwig, Tanja; Asbach, Patrick; Rasche, Franz Maximilian; Hamm, Bernd

    2009-04-01

    To assess the conservation status of, to gain information on the creation of, and to provide surface reformations of the core and the surface of the bust of the pharaoh-queen Nefertiti, considered to be one of the greatest treasures of ancient Egyptian art, with computed tomography (CT). Multisection CT was performed with 0.6-mm section thickness. Two- and three-dimensional reformations were made to depict the core and the surface separately. The stucco layer on the face and the ears was very thin, a maximum of 1-2 mm thick. The rear part of the reconstructed crown showed two thick stucco layers of different attenuation values, indicating that a multistep process was used to create the sculpture. Within the stucco, a great number of air-equivalent hypoattenuating areas, filamentous fissures parallel to the surface, and an inhomogeneous bonding between the layers were delineated. Nefertiti's inner face was not anonymous, but rather delicately sculpted by the royal sculptor Thutmose. The comparison to the outer face revealed differences, including the angles of the eyelids, creases around the corners of the mouth on the limestone surface, and a slight bump on the ridge of the nose. According to the beauty ideals of the Amarna period, the differences had positive and negative effects and can be read as signs of individualization of the sculpture. The potential material-related weaknesses of the sculpture that were revealed at imaging necessitate careful handling, with the avoidance of any focal pressure and shearing forces in the crown and the shoulders. CT imaging revealed construction techniques in Nefertiti's bust that had implications for conservation, as well as for an understanding of the artistic methods used in the creation of this masterpiece of art of the 18th dynasty.

  3. SPECIFIC FEATURES OF THE PORTRAIT IN NATIONAL PAINTING AND SCULPTURE (1945-1960

    Directory of Open Access Journals (Sweden)

    LOZOVANU VLADIMIR

    2016-12-01

    Full Text Available The present article is devoted to the peculiarities of the portrait in national painting and sculpture in the period of the 1950s. The text refl ects the creation of prominent artists who have realized the most famous portrait works. The author presents examples of representative portraits and they are analysed in the context of the period we refer to. He identifies both the methods, techniques, the ideas and aspiration of plastic artists who have practised portrait art. the presented information is useful to artists and teachers working in the fi eld of visual arts and to students who are interested in portrait painting.

  4. On Penelope Curtis’ Patio and Pavilion: The Place of Sculpture in Modern Architecture

    Directory of Open Access Journals (Sweden)

    Brian Hatton

    2014-02-01

    Full Text Available This is more of an engagement with Curtis’ classic text than a book review, its author being more concerned with expanding on the significance of some of the points made in Patio and Pavilion. Hatton explores the relationship between the artwork (mostly examples of sculpture and its architectural container (that is, the pavilion, museum or gallery, and way in which that binary is deconstructed in the work of a number of architect-artists from Mies van der Rohe through to Dan Graham, where the pavilion itself becomes the object of display.

  5. Teachingless spray-painting of sculptured surface by an industrial robot

    OpenAIRE

    Asakawa, Naoki; Takeuchi, Yoshimi

    1997-01-01

    The study deals with the automatic spray-painting by a 6-DOF industrial robot equipped with an air spray gun. Since the robot control commands generation for the spray-painting is manually performed by skilled workers using a teaching-playback function of a robot controller, the time, experience and patience are required. The study aims at making robot control commands without any special knowledge on spray-painting, in the case of bumpers of a car as an example of sculptured surfaces. The sy...

  6. Study of the laser cleaning on plaster sculptures. The effect of laser irradiation on the surfaces

    Science.gov (United States)

    Pelosi, C.; Fodaro, D.; Sforzini, L.; Rubino, A. R.; Falqui, A.

    2013-06-01

    The focus of this paper is to study the effects caused by the laser irradiation on nineteenth and twentieth century plaster sculptures. Before applying the laser cleaning on the sculptures, it was tested on samples prepared in laboratory according to the results of the scientific investigation carried out on the selected works of art. The characterization of the surface finishing materials of the sculptures was performed by Fourier Transform Infrared spectrometry (FTIR), X-ray Fluorescence spectroscopy (XRF), UV fluorescence photography, and internal micro stratigraphic analysis. Regarding the finishing materials, shellac, zinc white, siccative oil and proteins were found on the surfaces. The results of the scientific investigation, together with the examination of the ancient technical manuals, were used to create the laboratory samples to carry out the irradiation tests with laser. The laser irradiation and cleaning tests were carried out with a Q-switched Nd:YAG system. The irradiated surfaces were analyzed before and after the laser tests with the aid of a video microscope and a reflectance spectrophotometer, in order to evaluate the color changes of the surfaces. The possible morphological modifications caused by laser irradiation were also investigated by Scanning Electron Microscopy (SEM) together with ancillary Energy Dispersive Spectroscopy (EDS) elemental analysis. Concerning the laser cleaning test on the samples, in general little color changes were observed both with the 532 and 1064 nm wavelength. Total color changes, expressed as Δ E*, are always small apart from the samples made of shellac and zinc white in linseed oil, as finishing layer. As regards these samples the surface irradiated with the laser greyed lightly, corresponding to a decrease of L* parameter (lightness). SEM imaging of the treated and not-treated samples, both at low and high magnification, does not show evidence of significant morphological differences due to the laser beam

  7. Origin and implications of non-radial Imbrium Sculpture on the Moon.

    Science.gov (United States)

    Schultz, Peter H; Crawford, David A

    2016-07-21

    Rimmed grooves, lineations and elongate craters around Mare Imbrium shape much of the nearside Moon. This pattern was coined the Imbrium Sculpture, and it was originally argued that it must have been formed by a giant oblique (~30°) impact, a conclusion echoed by later studies. Some investigators, however, noticed that many elements of the Imbrium Sculpture are not radial to Imbrium, thereby implicating an endogenic or structural origin. Here we use these non-radial trends to conclude that the Imbrium impactor was a proto-planet (half the diameter of Vesta), once part of a population of large proto-planets in the asteroid belt. Such independent constraints on the sizes of the Imbrium and other basin-forming impactors markedly increase estimates for the mass in the asteroid belt before depletion caused by the orbital migration of Jupiter and Saturn. Moreover, laboratory impact experiments, shock physics codes and the groove widths indicate that multiple fragments (up to 2% of the initial diameter) from each oblique basin-forming impactor, such as the one that formed Imbrium, should have survived planetary collisions and contributed to the heavy impact bombardment between 4.3 and 3.8 billion years ago.

  8. Étude et restauration de deux sculptures de jardin en terre cuite

    Directory of Open Access Journals (Sweden)

    Sabrina Vétillard

    2012-06-01

    Full Text Available L’étude et la restauration de deux sphynges en terre cuite, particulièrement dégradées par leur installation en extérieur, ont permis d’approfondir la connaissance des techniques d’estampage, de caractériser les propriétés des terres cuites et les mécanismes de dégradation liés au gel. Les différentes techniques mises en oeuvre ont été l’occasion de réfléchir aux limites d’intervention pour des sculptures de jardin.The study and the restoration of two sphynges in terra-cotta, particularly degraded by their outdoor installation, allowed to deepen the knowledge of stamping techniques, to characterize the properties of terra-cottas and mechanisms of degradation bound to the frost. The different techniques used were the opportunity to think about limits of intervention for garden installed sculptures.

  9. Model Making and Anti-Competitive Practices in the Late Eighteenth-Century London Sculpture Trade

    Directory of Open Access Journals (Sweden)

    Craske, Matthew

    2014-03-01

    Full Text Available This article concerns the generation of anti-competitive practices, and the associated discontents, that rose to the fore in the London sculpture trade in the late eighteenth century (1770-1799. It charts the business strategies and technical procedures of the most economically successful practitioners, whose workshops had some of the characteristics of manufactories, and whose critics accused them of conducting a "monopoly" trade. Small-scale practitioners lost out in the competition for great public contracts on account of their design processes and their inability to represent any manifestation of "establishment". A combination of three factors increased the gap between a handful of powerful "manufacturers" and the rest of the trade: the foundation of the Royal Academy, shifts in the ways designs were evaluated, and a growing number of very lucrative contracts for public sculpture. I conclude that such were the discontents within the London trade that by the 1790s, there was a marked tendency for practitioners who were not manufacturers to be attracted to democratic political movements, to the Wilkite call for liberty and the rise of civic radicalism in the merchant population of London.

  10. Soluble salt sources in medieval porous limestone sculptures: a multi-isotope (N, O, S) approach.

    Science.gov (United States)

    Kloppmann, W; Rolland, O; Proust, E; Montech, A T

    2014-02-01

    The sources and mechanisms of soluble salt uptake by porous limestone and the associated degradation patterns were investigated for the life-sized 15th century "entombment of Christ" sculpture group located in Pont-à-Mousson, France, using a multi-isotope approach on sulphates (δ(34)S and δ(18)O) and nitrates (δ(15)N and δ(18)O). The sculpture group, near the border of the Moselle River, is within the potential reach of capillary rise from the alluvial aquifer. Chemical analyses show a vertical zonation of soluble salts with a predominance of sulphates in the lower parts of the statues where crumbling and blistering prevail, and higher concentrations of nitrates and chloride in the high parts affected by powdering and efflorescence. Isotope fingerprints of sulphates suggest a triple origin: (1) the lower parts are dominated by capillary rise of dissolved sulphate from the Moselle water with characteristic Keuper evaporite signatures that progressively decreases with height; (2) in the higher parts affected by powdering the impact of atmospheric sulphur becomes detectable; and (3) locally, plaster reparations impact the neighbouring limestone through dissolution and re-precipitation of gypsum. Nitrogen and oxygen isotopes suggest an organic origin of nitrates in all samples. N isotope signatures are compatible with those measured in the alluvial aquifer of the Moselle River further downstream. This indicates contamination by sewage or organic fertilisers. Significant isotopic contrasts are observed between the different degradation features depending on the height and suggest historical changes of nitrate sources. © 2013.

  11. Alison Gill – "To See a World", an exhibition of new sculpture and works on paper

    CERN Multimedia

    2013-01-01

    Wednesday, 11 December 2013 from 4 p.m. to 5 p.m. in the Library, bldg. 52 1-052 "Sculpture stories and invisible things" How might the presence of an artist influence the CMS experiment? And how does the LHC change the artist and the work they make? Over the last two decades, I have worked with a wide range of media to create both sculpture and drawing. The interdisciplinary approach that I have taken has often involved engagement and dialogues with scientists. Through my art, I explore the stories we tell to make sense of things that seem beyond our conscious grasp, taking familiar objects and materials and re-purposing, casting or altering the meaning. Underlying themes have included folklore, beliefs and methods used in the pursuit of transcendence. Knots, Klein bottles and Möbius strips have also been used for their topological, emotive and metaphysical associations. I try to scrutinise the world around me to find hidden meanings and use humour to provoke thought, elicit c...

  12. Sea ice - Multiyear cycles and white ice

    Science.gov (United States)

    Ledley, T. S.

    1985-01-01

    The multiyear thickness cycles represent one of the interesting features of the sea ice studies performed by Semtner (1976) and Washington et al. (1976) with simple thermodynamic models of sea ice. In the present article, a description is given of results which show that the insulating effect of snow on the surface of the sea ice is important in producing these multiyear cycles given the physics included in the model. However, when the formation of white ice is included, the cycles almost disappear. White ice is the ice which forms at the snow-ice interface when the snow layer becomes thick enough to depress the ice below the water level. Water infiltrates the snow by coming through the ice at leads and generally freezes there, forming white ice.

  13. Joep van Lieshout's Mobile Home for Kröller-Müller: outdoor polyester sculpture in transit

    NARCIS (Netherlands)

    Stigter, S.; Beerkens, L.; Schellen, H.L.; Kuperholc, S.; Bridgland, J.

    2008-01-01

    The nature and condition of the large scale glass fibre reinforced polyester resin outdoor sculpture by Dutch artist Joep van Lieshout: Mobile Home for Kröller-Müller (1995) is challenging traditional conservation ethics. Chemists, physicists, art historians, conservators specialised in different

  14. Ars Moriendi Tradition and Visualization of Death in Roman Baroque Sculpture: Death Education in the Seventeenth Century.

    Science.gov (United States)

    Westin, Robert H.

    1980-01-01

    The tradition of the Ars Moriendi influenced art by creating a new reality in which the dead could appear eternally alive. A good death was seen as an act of faith. The literature of Ars Moriendi influenced baroque sculpture which today is viewed as almost bizarre. (JAC)

  15. Photographer: NASA Ames On 20 December 1989, Ames buried a time capsule and unveiled a sculpture at

    Science.gov (United States)

    1989-01-01

    Photographer: NASA Ames On 20 December 1989, Ames buried a time capsule and unveiled a sculpture at the spot where, fifty years earlier, Russel Robinson had turned the first spade of dirt for the Ames construction shack: Robinson (left) Ames Director Dale Compton (center) and Ames Deputy Director Sy Syvertson (right)

  16. Spines vs. microspines: an overview of the sculpture exine in selected basal and derived Asteraceae with focus on Asteroideae.

    Science.gov (United States)

    Tellería, María C

    2017-11-01

    This study presents a detailed examination of the echinate and microechinate sculpturing in relation to the size of pollen grains in 31 selected species of Asteraceae belonging to the subfamilies Barnadesioideae, Mutisioideae, Carduoideae and Asteroideae. The aims were to recognize sculpturing patterns, under LM and SEM, within large and small pollen of both basal and derived species and to explore the features that could have taxonomic value to apply in palynological disciplines. The detailed examination of the exine surface showed both the relevance and limits of sculptural patterns for taxonomy. Under LM, the microechinate sculpture gave little taxonomic information, whereas in the echinate sculpture, three exine types and two subtypes were recognized. Type I included microechinate exine, which is commonly present in large pollen grains of the basal lineages. Types II (subtypes IIa and IIb) and III included echinate and smaller pollen grains. In these types, spines were always regularly arranged and, were characterized by the length, shape, tip, perforations and distribution. Type IIa included more or less conical spines usually with a distended base, less than 4 µm in length, present in species of different tribes like Astereae, Eupatorieae, Helenieae, Gnaphalieae, Senecioideae and Heliantheae to a lesser extent. Type IIb includes slender spines with narrower bases, longer than 4 µm, present in species of Coreopsideae, Heliantheae, Tageteae and Eupatorieae to a lesser extent. Type III included spines with swollen base, blunt tip and perforations over their entire surface. This type was present in only one of the basal species-Carduus thoermeri-and in one species of the derived tribe Helenieae, Gaillardia megapotamica. Probably, this is due to evolutionary convergence.

  17. Great Lakes Ice Charts

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Charts show ice extent and concentration three times weekly during the ice season, for all lakes except Ontario, from the 1973/74 ice season through the 2001/2002...

  18. A highly sensitive multiplasmonic sensor using hyperbolic chiral sculptured thin films

    Science.gov (United States)

    Abbas, Farhat; Faryad, Muhammad

    2017-11-01

    Surface plasmon-polariton (SPP) waves guided by an interface of a metal and a hyperbolic chiral sculptured thin film (STF) were theoretically investigated for optical sensing of an analyte. The chiral STF was infiltrated with the analyte to be sensed, and the resulting change in the incidence angle of excitation of the SPP waves in the prism-coupled configuration was computed. The results indicated the potential of this configuration for a plasmonic sensor with sensitivity up to 6000 degrees per refractive index units of the infiltrating fluid in the angular investigation scheme, with multiple SPP waves of the same frequency but different phase speeds, spatial profiles, and sensitivities. The enhancement in the sensitivity is attributed to the high field strength of the SPP waves near the interface. A multiplasmonic sensor is advantageous because of its potential for higher confidence in the measurement of the same analyte.

  19. Non-exhibition of Bragg phenomenon by chevronic sculptured thin films

    Science.gov (United States)

    Vepachedu, Vikas; McAtee, Patrick D.; Lakhtakia, Akhlesh

    2017-08-01

    The unit cell of a chevronic sculptured thin film (ChevSTF) comprises two identical columnar thin films (CTFs) except that the nanocolumns of the first are oriented at an angle Χ and nanocolumns of the second are oriented at an angle π - χ with respect to the interface of the two CTFs. A ChevSTF containing 10 unit cells was fabricated and its planewave reflectance and transmittance spectrums of this ChevSTF were measured. Despite its structural periodicity, the ChevSTF did not exhibit the Bragg phenomenon. Theoretical calculations with the CTFs modeled as biaxial dielectric materials indicated that the Bragg phenomenon would not be manifested for normal and near-normal incidence, but vestigial manifestation was possible for sufficiently oblique incidence.

  20. Homogeneity analysis of sculptured thin films deposited in symmetric style through glancing angle deposition technique

    International Nuclear Information System (INIS)

    Wang Bin; Qi Hong-Ji; Sun Wei; He Jun; Zhao Jiao-Ling; Wang Hu; Hou Yong-Qiang

    2014-01-01

    The symmetric deposition technique is often used to improve the uniformity of sculptured thin film (STF). In this paper, optical properties of STF with the columnar angles ±β are analyzed theoretically, based on the characteristic matrix method for extraordinary waves. Then, the transmittances of uniformity monolayer and bilayer STF in symmetrical style are calculated to show the effect of the bilayer structure on the optical properties of STF. The inhomogeneity of STF is involved in analyzing the differences in transmittance and phase retardation between monolayer and bilayer STF deposited in symmetric style. The results show that optical homogeneity of STF can be improved by depositing in symmetric style at the normal incidence, but it is not the same case as the oblique incidence. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  1. Using Soft Sculpture Microfossils and Other Crafted Models to Teach Geoscience

    Science.gov (United States)

    Spinak, N. R.

    2017-12-01

    For the past 5 years, the International Ocean Discovery Program (IODP) has been using the author's sewn models of microfossils to help learners understand the shapes and design of these tiny fossils. These tactile objects make the study of ancient underwater life more tangible. Multiple studies have shown that interactive models can help many learners understand science. The Montessori and Waldorf education programs are based in large part on earlier insights into meeting these needs. The act of drawing has been an essential part of medical education. The STEAM (Science, Technology, Engineering, Arts and Math) movement has advocated for STEM supporters to recognize the inseparability of science and art. This presentation describes how the author's knitted or sewn models of microfossils incorporate art and design into geoscience education. The geoscience research and art processes used in developing and creating these educational soft sculptures will be described. In multiple entry points to science study, specific reciprocal benefits to boundary crossing among the arts and sciences for those who have primary talents in a particular area of study will be discussed. Geoscience education can benefit from using art and craft items such as models. Many websites now offer soft sculptures for biology study such as organs and germs (e.g. (https://www.giantmicrobes.com/us/main/nasty-germs). The Wortheim project involving community and crochet is another approach (http://crochetcoralreef.org/). These tactile artifacts give learners an entry-level experience with biology. Three dimensional models are multisensory. The enlarged manipulative microfossil models invite learners to make comparisons and gain insights when microscopes are not available or appropriate for the audience. Adding the physical involvement of creating a microfossil yourself increases the multi-sensory experience even further. Learning craft skills extends the cross-cutting concepts of the NGSS to a mutual

  2. Forecasting Turbine Icing Events

    DEFF Research Database (Denmark)

    Davis, Neil; Hahmann, Andrea N.; Clausen, Niels-Erik

    2012-01-01

    In this study, we present a method for forecasting icing events. The method is validated at two European wind farms in with known icing events. The icing model used was developed using current ice accretion methods, and newly developed ablation algorithms. The model is driven by inputs from the WRF...... mesoscale model, allowing for both climatological estimates of icing and short term icing forecasts. The current model was able to detect periods of icing reasonably well at the warmer site. However at the cold climate site, the model was not able to remove ice quickly enough leading to large ice...... accumulations, which have not been seen in observations. In addition to the model evaluation we were able to investigate the potential occurrence of ice induced power loss at two wind parks in Europe using observed data. We found that the potential loss during an icing event is large even when the turbine...

  3. Ice sheet margins and ice shelves

    Science.gov (United States)

    Thomas, R. H.

    1984-01-01

    The effect of climate warming on the size of ice sheet margins in polar regions is considered. Particular attention is given to the possibility of a rapid response to warming on the order of tens to hundreds of years. It is found that the early response of the polar regions to climate warming would be an increase in the area of summer melt on the ice sheets and ice shelves. For sufficiently large warming (5-10C) the delayed effects would include the breakup of the ice shelves by an increase in ice drainage rates, particularly from the ice sheets. On the basis of published data for periodic changes in the thickness and melting rates of the marine ice sheets and fjord glaciers in Greenland and Antarctica, it is shown that the rate of retreat (or advance) of an ice sheet is primarily determined by: bedrock topography; the basal conditions of the grounded ice sheet; and the ice shelf condition downstream of the grounding line. A program of satellite and ground measurements to monitor the state of ice sheet equilibrium is recommended.

  4. Ice Lithography for Nanodevices

    DEFF Research Database (Denmark)

    Han, Anpan; Kuan, A.; Wang, J.

    Water vapor is condensed onto a cold sample, coating it with a thin-film of ice. The ice is sensitive to electron beam lithography exposure. 10 nm ice patterns are transferred into metals by “melt-off”. Non-planar samples are coated with ice, and we pattern on cantilevers, AFM tips, and suspended...

  5. Thin-section microscopy of decayed crystalline marble from the garden sculptures of Schoenbrunn Palace in Vienna

    International Nuclear Information System (INIS)

    Weber, J.; Beseler, S.; Sterflinger, K.

    2007-01-01

    Sterzing marble, a crystalline white marble used in the late-Baroque garden sculptures of Schoenbrunn Palace in Vienna, was studied by means of thin-section and scanning electron microscopy in order to obtain a better understanding of its surface decay caused by atmospheric weathering. Following the classification of distinct phenomena of deterioration by visual on-site inspection, the microstructural features including surface erosion, micro-cracking, soiling, black crust formation, and microbiological infestation are exemplified by microscopical images and are briefly discussed. The results proved useful for evaluating and understanding the various types of marble decay for creating a safer basis for establishing the procedural principles aimed at conservation and maintenance of the sculptures

  6. Painted Fiberglass-Reinforced Contemporary Sculpture: Investigating Composite Materials, Techniques and Conservation Using a Multi-Analytical Approach.

    Science.gov (United States)

    Salvadori, Barbara; Cantisani, Emma; Colombini, Maria Perla; Tognon, Cecilia Gaia Rachele

    2016-01-01

    A multi-analytical approach was used to study the constituent materials, manufacturing technique, and state of conservation of a contemporary sculpture. This sculpture, entitled Nuredduna, was created by Aligi Sassu in 1995 and is located in the "Bellariva garden" in Florence (Italy). Fourier transform infrared spectroscopy (FT-IR), optical and electronic microscopy (OM and SEM-EDS), X-ray diffraction (XRD), and portable X-ray fluorescence (XRF) highlighted the multi-layered structure of the statue: fiberglass and an overlay of different layers (gel coat) applied with an unsaturated polyester resin added with aggregate materials and bromine compounds. A top-coat in acrylic black varnish, used as a finish, was also found. The combination of these materials with their different compositions, environmental impact, and even vandalism have negatively affected the state of conservation of Nuredduna, causing the loss of strata in its lower parts (legs and feet). © The Author(s) 2015.

  7. The conservation treatment of a contemporary collaged sculpture by Jiří Kolář (1914-2002

    Directory of Open Access Journals (Sweden)

    Jessica Crann

    2010-11-01

    Full Text Available Une sculpture représentant une pomme réalisée par collage de l’artiste tchèque Jiří Kolář et datant de 1972, a été soumise à un traitement de conservation-restauration. La sculpture présentait des dommages structurels causés par des facteurs externes ainsi que des surfaces encrassées. Les interrogations déontologiques soulevées lors de la restauration d’une œuvre d’art contemporain ont représenté un aspect important de l’étude. Par conséquent, la majeure partie des recherches a été dévolue à  la compréhension du matériau et de la structure, celle des intentions de l’artiste,tout comme du concept et de la signification de l’œuvre. Ce travail a été étayé par une recherche scientifique ayant pour but d’évaluer l’efficacité du Triammonium citrate comme agent de nettoyage à base aqueuse, ainsi que par une analyse de la construction en trois dimensions de l’œuvre d’art.A collaged sculpture of an apple by the Czech artist Jiří Kolář, dated 1972 was presented for conservation. The sculpture suffered from structural damage caused by external factors and ingrained surface dirt. The ethical implications raised in conserving a contemporary artwork were an important aspect and subsequently an understanding of the materials and structure, the artist’s intentions, concept and meaning of the artwork formed a large part of the research. Combined with this was scientific research into the effectiveness of Tri-ammonium Citrate as an aqueous surface cleaning agent and analysing construction of 3-Dimensional artworks.

  8. Visiting Richard Serra’s “Promenade” sculpture improves postural control and judgment of subjective visual vertical

    Science.gov (United States)

    Kapoula, Zoï; Lang, Alexandre; Lê, Thanh-Thuan; Adenis, Marie-Sarah; Yang, Qing; Lipede, Gabi; Vernet, Marine

    2014-01-01

    Body sway while maintaining an upright quiet stance reflects an active process of balance based on the integration of visual, vestibular, somatosensory, and proprioceptive inputs. Richard Serra’s Promenade sculpture featured in the 2008 Monumenta exhibition at the Grand Palais in Paris, France is herein hypothesized to have stimulated the body’s vertical and longitudinal axes as it showcased five monumental rectangular solids pitched at a 1.69° angle. Using computerized dynamic posturography we measured the body sway of 23 visitors when fixating a cross, or when observing the artwork (fixating it or actively exploring it with eye movements) before and after walking around and alongside the sculpture (i.e., before and after a promenade). A first fixation at the sculpture increased medio-lateral stability (in terms of spectral power of body sway). Eye movement exploration in the depth of the sculpture increased antero-posterior stability [in terms of spectral power and canceling time (CT) of body sway] at the expense of medio-lateral stability (in terms of CT). Moreover, a medio-lateral instability associated with eye movement exploration before the promenade (in terms of body sway sensu stricto) was canceled after the promenade. Finally, the overall medio-lateral stability (in terms of spectral power) increased after the promenade. Fourteen additional visitors were asked to stand in a dark room and adjust a luminous line to what they considered to be the earth-vertical axis. The promenade executed within the sculpted environment afforded by Serra’s monumental statuary works resulted in significantly improved performances on the subjective visual vertical test. We attribute these effects to the sculpted environment provided by the exhibition which may have acted as a kind of physiologic “training ground” thereby improving the visitors’ overall sense of visual perspective, equilibrium, and gravity. PMID:25566107

  9. Treasures ... of black wood, brilliantly polished : five examples of Taino sculpture from the tenth-sixteenth century Caribbean.

    Science.gov (United States)

    Joanna Ostapkowicz; Alex Wiedenhoeft; Christopher Bronk Ramsey; Erika Ribechini; Samuel Wilson; Fiona Brock; Tom Higham

    2011-01-01

    Five wooden sculptures from the pre-contact Caribbean, long held in museum collections, are here dated and given a context for the first time. The examples studied were made from dense Guaiacum wood, carved, polished and inlaid with shell fastened with resin. Dating the heartwood, sapwood and resins takes key examples of ‘Classic’ Ta´ýno art back to the tenth century...

  10. FTIR spectroscopy of woods: A new approach to study the weathering of the carving face of a sculpture.

    Science.gov (United States)

    Emmanuel, Vartanian; Odile, Barres; Céline, Roque

    2015-02-05

    Fourier transform infrared spectroscopy (FTIR), a useful method to study woods, has been applied in order to measure an eventual gradient of water absorbed (more precisely, hydroxyl groups, OH) between the surface and the inner part of an ancient and a modern wooden sculptures. The methodology adopted has consisted in comparing FTIR bands within two spectral ranges, one corresponding to the OH content in the wood (around 3400cm(-1)) and the other to the lignin molecules (aromatic CC, around 1610cm(-1)). The ratio between the intensities of the peaks leads to a self-normalization of the measurements which avoids the effects of some experimental parameters (such as sample preparation). The results obtained show that there is a significant and progressive penetration of OH groups from the surface to the inside part of the ancient sculpture (more OH on the surface than inside the wood, due to the aging of the surface and the creation of sites which are able to fix OH groups). In contrary, for the modern one, we measure an increase of OH contents from the surface to the inner part of the sculpture. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Petrographic characterization and provenance determination of the white marbles used in the Roman sculptures of Forum Sempronii (Fossombrone, Marche, Italy)

    Science.gov (United States)

    Antonelli, Fabrizio; Columbu, Stefano; Lezzerini, Marco; Miriello, Domenico

    2014-06-01

    The Roman municipium of Forum Sempronii (Fossombrone, Marche) was located along the `Via Consolare Flaminia', in the stretch of road where it ran along the final sector of the valley of the River Metauro ( Mataurus). The ancient colony of Forum Sempronii, which is cited by Strabo, Pliny, and Ptolemy, was found in the second century BC, probably on the site of an earlier community and its activity continued until the end of the fifth century AD. During ancient and more recent archaeological excavations, many fragments of coloured stones and marbles, and some white marble sculptures have been unearthed. In this paper, we report the results of the provenance identification of the white marbles used for the sculptures found in the archaeological site of Forum Sempronii and now displayed at the local archaeological museum. The determination of the source origin of the white marbles used for the sculptures has been established by mineralogical-petrographic and geochemical analyses. Microscopic study of thin sections together with carbon and oxygen stable isotope ratios indicate that more than one type of white marbles was used: Pentelikon, Lunense, and Thasian.

  12. Incompatible building materials within the stereotomic Avalos sculptures of the Valley of Fallen (Madrid, Spain

    Directory of Open Access Journals (Sweden)

    García-Guinea, J.

    2013-03-01

    Full Text Available The examination of the recently open pit in top of head of the La Piety sculpture of Avalos confirms that the external outer of Black Limestone Calatorao (BLC composite is made by slabs 20 cm thick joined with gypsum mortars without aggregates. The analyses of these mortars samples performed by optical microscopy (OM, X-ray diffraction (XRD and Environmental Scanning Electron Microscopy with Energies Dispersive Spectrometry (ESEM-EDS techniques show hydrous admixtures composed by portlandite, mirabilite, ettringite, thaumasite and gypsum, all of them are well-know dangerous phases for a suitable preservation of the architectural heritage. The huge stereotomic structures have open access to the raining waters reaching the internal core of the sculptures made by concrete with weathered alkali-feldspar aggregates providing sodium to the surrounding sulfated environment facilitating the formation of hydrous calcium and sodium sulfates such as ettringite and mirabilite which reduces the inter-grains adherence.

    El estudio de un boquete abierto recientemente en la cabeza de la escultura de la Piedad de Avalos confirma que está recubierta por placas caliza negra de Calatorao (CNC de unos 20 cm de espesor sujetas con morteros de yeso sin áridos. El análisis de estas muestras de morteros mediante microscopía óptica (MO, difracción de rayos X (DRX y Microscopía Electrónica de Barrido Ambiental con Espectroscopia de Dispersión de Energías dispersivas de rayos X (MEBA-EDS muestra mezclas de portlandita, mirabilita, etringita, taumasita y yeso, es decir, fases hidratadas bien conocidas por ser peligrosas para una adecuada preservación del patrimonio arquitectónico. Las gigantescas estructuras estereotómicas de Avalos están abiertas a las aguas de lluvia llegando a alcanzar sus núcleos de hormigón, que tienen áridos de granitos con feldespatos alcalinos alterados que están aportando sodio al ambiente sulfatado formando nuevos sulfatos

  13. Dye sensitized solar cells based on nanowire sculptured thin film titanium dioxide photoanodes

    Science.gov (United States)

    Pursel, Sean M.

    Energy harvested from the sun using photovoltaics (PVs) is a renewable resource in high demand. Photovoltaics convert photons into electron-hole pairs which are then separated and used for electrical power. 75 TW of energy arrives from the sun every year onto US soil. Harvesting it all would provide enough energy to power the entire world for more than five years. It is this abundance of energy that makes PVs an attractive alternative to fossil fuels. PVs currently produce 0.15% of the energy consumed in the US. Production needs to grow as the worldwide demand for energy is projected to almost double by 2050. Fundamental and device based PV research have made steady efficiency gains in silicon based devices and thin film devices have started to become commercially viable. However, less expensive devices with suitable efficiency have not been fully developed. Dye sensitized solar cells (DSSCs) are one such device which has been optimized using standard components. However, device efficiency has not increased significantly since DSSCs were first conceived in 1991. Interestingly, none of the standard components are optimized, but act in a synergistic way in the most efficient devices. This research, along with other parallel research, attempts to optimize a single component of DSSCs with the goal of combining efforts to produce a device with increased efficiency. This research attempts to optimize the TiO2 photoanode used in DSSCs in terms of electron collection, dye coverage, light harvesting, and novel electrolyte infiltration by replacing the standard colloidal structure with nanowires deposited using physical vapor deposition at an oblique angle to form sculptured thin films. The results are quantified through standard photovoltaic testing, electrochemical impedance spectroscopy, UV-Vis-NIR spectroscopy, and general materials characterization techniques. The nanowire photoanodes are engineered during deposition using reactive evaporation, substrate heating

  14. Stochastic ice stream dynamics.

    Science.gov (United States)

    Mantelli, Elisa; Bertagni, Matteo Bernard; Ridolfi, Luca

    2016-08-09

    Ice streams are narrow corridors of fast-flowing ice that constitute the arterial drainage network of ice sheets. Therefore, changes in ice stream flow are key to understanding paleoclimate, sea level changes, and rapid disintegration of ice sheets during deglaciation. The dynamics of ice flow are tightly coupled to the climate system through atmospheric temperature and snow recharge, which are known exhibit stochastic variability. Here we focus on the interplay between stochastic climate forcing and ice stream temporal dynamics. Our work demonstrates that realistic climate fluctuations are able to (i) induce the coexistence of dynamic behaviors that would be incompatible in a purely deterministic system and (ii) drive ice stream flow away from the regime expected in a steady climate. We conclude that environmental noise appears to be crucial to interpreting the past behavior of ice sheets, as well as to predicting their future evolution.

  15. Sea Ice Ecosystems

    Science.gov (United States)

    Arrigo, Kevin R.

    2014-01-01

    Polar sea ice is one of the largest ecosystems on Earth. The liquid brine fraction of the ice matrix is home to a diverse array of organisms, ranging from tiny archaea to larger fish and invertebrates. These organisms can tolerate high brine salinity and low temperature but do best when conditions are milder. Thriving ice algal communities, generally dominated by diatoms, live at the ice/water interface and in recently flooded surface and interior layers, especially during spring, when temperatures begin to rise. Although protists dominate the sea ice biomass, heterotrophic bacteria are also abundant. The sea ice ecosystem provides food for a host of animals, with crustaceans being the most conspicuous. Uneaten organic matter from the ice sinks through the water column and feeds benthic ecosystems. As sea ice extent declines, ice algae likely contribute a shrinking fraction of the total amount of organic matter produced in polar waters.

  16. Ross Ice Shelf, Antarctic Ice and Clouds

    Science.gov (United States)

    1991-01-01

    In this view of Antarctic ice and clouds, (56.5S, 152.0W), the Ross Ice Shelf of Antarctica is almost totally clear, showing stress cracks in the ice surface caused by wind and tidal drift. Clouds on the eastern edge of the picture are associated with an Antarctic cyclone. Winds stirred up these storms have been known to reach hurricane force.

  17. Artificial immune algorithm implementation for optimized multi-axis sculptured surface CNC machining

    Science.gov (United States)

    Fountas, N. A.; Kechagias, J. D.; Vaxevanidis, N. M.

    2016-11-01

    This paper presents the results obtained by the implementation of an artificial immune algorithm to optimize standard multi-axis tool-paths applied to machine free-form surfaces. The investigation for its applicability was based on a full factorial experimental design addressing the two additional axes for tool inclination as independent variables whilst a multi-objective response was formulated by taking into consideration surface deviation and tool path time; objectives assessed directly from computer-aided manufacturing environment A standard sculptured part was developed by scratch considering its benchmark specifications and a cutting-edge surface machining tool-path was applied to study the effects of the pattern formulated when dynamically inclining a toroidal end-mill and guiding it towards the feed direction under fixed lead and tilt inclination angles. The results obtained form the series of the experiments were used for the fitness function creation the algorithm was about to sequentially evaluate. It was found that the artificial immune algorithm employed has the ability of attaining optimal values for inclination angles facilitating thus the complexity of such manufacturing process and ensuring full potentials in multi-axis machining modelling operations for producing enhanced CNC manufacturing programs. Results suggested that the proposed algorithm implementation may reduce the mean experimental objective value to 51.5%

  18. Ancient lenses in art and sculpture and the objects viewed through them, dating back 4500 years

    Science.gov (United States)

    Enoch, Jay M.

    1998-07-01

    The early history of lenses is controversial. The author has sought to address the problem by identifying lens elements (mainly convex/plano) which remain associated with objects intended to be viewed through them (i.e., in their original context). These are found in museums in sculptures, rings, pendants, etc. A number of outstanding examples will be illustrated in the talk; these sophisticated pieces of art are certainly not first constructs. Most are of rock crystal, rose quartz, or glass. Lenses have origin among artisans rather than scientists. Clearly, skills were often lost and rediscovered. Early lens-like objects have been found broadly in the eastern Mediterranean area/Middle East, in France, in Italy (Rome), and possibly in Peru and Scandinavia, etc. To date, the earliest lenses identified in context are from the IV/V Dynasties of Egypt, dating back to about 4500 years ago (e.g., the superb `Le Scribe Accroupi' and `the Kai' in the Louvre; added fine examples are located in the Cairo Museum). Latter examples have been found in Knossos (Minoan [Herakleion Museum]; ca. 3500 years ago); others had origin in Greece (examples in the Athens National Archeological Museum and the British Museum equals BM), in Rome (Metropolitan Museum, NY; BM; Vatican Museums; Bologna Archeological Museum), etc. Also. of great interest is the study of possible lens applications. This is a fascinating scientific, artistic and intellectual project.

  19. Stereoscopic CAD and Environmental Sculpture: Enhancement of the Design Process in the Visual Arts

    Science.gov (United States)

    Fisher, Robert N.; Bandini, Pier L.

    1989-09-01

    In this paper, co-authors Robert Fisher and Pier Luigi Bandini describe their personal observations concerning stereo enhancements of computer graphics images employed in their research. in Part One, Robert Fisher, a professional sculptor, Professor and Artist-in-Residence in the College of Engineering at Penn State, cites three recent environmental sculpture projects: "See-scape," "A Page from the Book of Skies," and an as yet untitled work. Wireframe images, interior views of architectural spaces, and complex imagery are rendered comprehensible by stereo 3-D. In Part Two, Pier L. Bandini, Associate Professor of Architecture and Director of the Architecture CAD Lab at Penn State, describes the virtues of the stereo-enhanced wireframe model--the benefits of the "see-through coupled with a complete awareness of the whole space." The final example, of a never-realized XVIII-century project, suggests a new and profound application of stereo 3-D to historical inquiry, namely, the experience of ancient spaces and structures that are no longer existing or that were never constructed.

  20. Nonexhibition of Bragg phenomenon by chevronic sculptured thin films: experiment and theory

    Science.gov (United States)

    Vepachedu, Vikas; McAtee, Patrick D.; Lakhtakia, Akhlesh

    2017-07-01

    The unit cell of a chevronic sculptured thin film (ChevSTF) comprises two identical columnar thin films (CTFs) except that the nanocolumns of the first are oriented at an angle χ and nanocolumns of the second are oriented at an angle π-χ with respect to the interface of the two CTFs. A ChevSTF containing 10 unit cells was fabricated using resistive-heating physical vapor deposition of zinc selenide. Planewave reflectance and transmittance spectrums of this ChevSTF were measured for a wide variety of incidence conditions over the 500- to 900-nm range of the free-space wavelength. Despite its structural periodicity, the ChevSTF did not exhibit the Bragg phenomenon. Theoretical calculations with the CTFs modeled as biaxial dielectric materials indicated that the Bragg phenomenon would not be manifested for normal and near-normal incidence, but vestigial manifestation was possible for sufficiently oblique incidence. Thus, structural periodicity does not always lead to electromagnetic periodicity that underlies the exhibition of the Bragg phenomenon.

  1. Antarctic Ice Velocity Data

    Data.gov (United States)

    National Aeronautics and Space Administration — This compilation of recent ice velocity data of the Antarctic ice sheet is intended for use by the polar scientific community. The data are presented in tabular form...

  2. Current Icing Product

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Current Icing Product (CIP) is an automatically-generated index suitable for depicting areas of potentially hazardous airframe icing. The CIP algorithm combines...

  3. Aircraft Icing Handbook. (Update)

    Science.gov (United States)

    1993-01-01

    pp. 68-69, 1947. Speranza, F., OThe Formation of Ice,a Rivista di Meteorologia Aeronautics, 1(2), pp. 19-30, 1937. Steiner, R. 0., "The Icing of...Deposits of Ice on Airplane Carburetors,8 (Translation) Rivista di Meteorologia Aeronautica, 4(2), pp. 38-47, 1940. Von Glahn, U. H.; Renner, C. E

  4. Technology for Ice Rinks

    Science.gov (United States)

    1983-01-01

    Ron Urban's International Ice Shows set up portable ice rinks for touring troupes performing on temporary rinks at amusement parks, sports arenas, dinner theaters, shopping malls and civic centers. Key to enhanced rink portability, fast freezing and maintaining ice consistency is a mat of flexible tubing called ICEMAT, an offshoot of a solar heating system developed by Calmac, Mfg. under contract with Marshall.

  5. Determination of weathering and conservation of sculptured stone by use of the laser method

    International Nuclear Information System (INIS)

    Aaberg, G.; Stijfhoorn, D.E.

    1996-09-01

    Weathering and deterioration of sculptured stone and masonry is a natural process which stars at the same moment the stone is quarried and exposed to exogenous conditions. This process of natural decay has, however, been accelerated due to the emission of different man-made pollutants, domestic and industrial, local and global. The ISOLASER project is based on the laser microprobe technique for determining the depth of natural and induced weathering and the effect of conservation measures of cultural objects of carbonaceous sandstone and marble/limestone. The purpose of the project is to determine the depth of weathering and depth of penetration of conservation agents in unweathered calcite-cemented stone and the weathering profile in linseed oil-treated stone after accelerated weathering cycles in a climatic chamber. The analytical results show that even after such a short period as five weeks of exposure the effect of SO 2 , NO 2 and elevated humidity on Gotland sandstone can be easily observed in a change of the δ 13 C values in the outermost 2 mm of the stone. Treating the sample with linseed oil has a preserving effect on the rock and hinders the deteriorating effect of SO 2 and NO 2 . The oil treatment even preserves the signature of previously incorporated organic carbon. Compilation of a questionnaire representing a broad field within natural sciences in cultural heritage research in Europe, shows an overwhelming positive approach to the project as such. The questioned researchers consider the laser method particularly useful as a complementary method in other investigations and states that the method can without doubt give new dimensions to the analysis of important cultural objects. 2 refs., 6 figs

  6. Documentation and dissemination of the sculptural elements of Canada's Parliamentary Buildings: Methodology development and evolution, a case study

    Directory of Open Access Journals (Sweden)

    C. Ouimet

    2015-08-01

    Full Text Available Parliament Hill consists of four historic gothic revival buildings, which form part of the Parliament Buildings National Historic Site of Canada in the National Capital of Ottawa. There are more than 2000 masonry sculptural elements throughout the four buildings. Three of the buildings are in the middle of multi-year rehabilitation projects. Extensive Heritage Documentation is being undertaken to support various activities and conservation teams throughout the interior and exterior of the buildings while also serving as a key posterity records. One of the significant heritage documentation projects is the 3D digitization of the 2000+ heritage character defining sculptural elements. The Heritage Conservation Directorate (HCD of Public Works and Government Services Canada (PWGSC was tasked by the Parliamentary Precinct Branch (PPB of PWGSC to document these character defining elements. The sculptures vary in size from as small as 100mm in width to up to 2 meters in size. This project is in its third year and much has been learned and researched about the most appropriate and efficient means by which to document these elements. Although a methodology was in place to document the sculptures at the inception of the project, it has gone through several iterations in order to improve the gathered data, and in turn increase the efficiency, quality and speed of data acquisition. This paper will describe the evolution of the methodology, as well as the rationale for the alterations in technique. With over 600 of the approximate 2000 (heritage character defining sculptural elements captured to date, the project is entering a critical phase where an efficient and effective method for sharing and disseminating the information to a wide audience is being explored and evaluated. The end result is intended to allow the client (PPB and the general public a way to look at and interactively manipulate the viewpoint of each digital model. This will provide a unique

  7. Documentation and dissemination of the sculptural elements of Canada's Parliamentary Buildings: Methodology development and evolution, a case study

    Science.gov (United States)

    Ouimet, C.; Gregg, J.; Kretz, S.; Chandler, C.; Hayes, J.

    2015-08-01

    Parliament Hill consists of four historic gothic revival buildings, which form part of the Parliament Buildings National Historic Site of Canada in the National Capital of Ottawa. There are more than 2000 masonry sculptural elements throughout the four buildings. Three of the buildings are in the middle of multi-year rehabilitation projects. Extensive Heritage Documentation is being undertaken to support various activities and conservation teams throughout the interior and exterior of the buildings while also serving as a key posterity records. One of the significant heritage documentation projects is the 3D digitization of the 2000+ heritage character defining sculptural elements. The Heritage Conservation Directorate (HCD) of Public Works and Government Services Canada (PWGSC) was tasked by the Parliamentary Precinct Branch (PPB) of PWGSC to document these character defining elements. The sculptures vary in size from as small as 100mm in width to up to 2 meters in size. This project is in its third year and much has been learned and researched about the most appropriate and efficient means by which to document these elements. Although a methodology was in place to document the sculptures at the inception of the project, it has gone through several iterations in order to improve the gathered data, and in turn increase the efficiency, quality and speed of data acquisition. This paper will describe the evolution of the methodology, as well as the rationale for the alterations in technique. With over 600 of the approximate 2000 (heritage character defining) sculptural elements captured to date, the project is entering a critical phase where an efficient and effective method for sharing and disseminating the information to a wide audience is being explored and evaluated. The end result is intended to allow the client (PPB) and the general public a way to look at and interactively manipulate the viewpoint of each digital model. This will provide a unique opportunity

  8. Arctic ice management

    Science.gov (United States)

    Desch, Steven J.; Smith, Nathan; Groppi, Christopher; Vargas, Perry; Jackson, Rebecca; Kalyaan, Anusha; Nguyen, Peter; Probst, Luke; Rubin, Mark E.; Singleton, Heather; Spacek, Alexander; Truitt, Amanda; Zaw, Pye Pye; Hartnett, Hilairy E.

    2017-01-01

    As the Earth's climate has changed, Arctic sea ice extent has decreased drastically. It is likely that the late-summer Arctic will be ice-free as soon as the 2030s. This loss of sea ice represents one of the most severe positive feedbacks in the climate system, as sunlight that would otherwise be reflected by sea ice is absorbed by open ocean. It is unlikely that CO2 levels and mean temperatures can be decreased in time to prevent this loss, so restoring sea ice artificially is an imperative. Here we investigate a means for enhancing Arctic sea ice production by using wind power during the Arctic winter to pump water to the surface, where it will freeze more rapidly. We show that where appropriate devices are employed, it is possible to increase ice thickness above natural levels, by about 1 m over the course of the winter. We examine the effects this has in the Arctic climate, concluding that deployment over 10% of the Arctic, especially where ice survival is marginal, could more than reverse current trends of ice loss in the Arctic, using existing industrial capacity. We propose that winter ice thickening by wind-powered pumps be considered and assessed as part of a multipronged strategy for restoring sea ice and arresting the strongest feedbacks in the climate system.

  9. Dead-ice environments

    DEFF Research Database (Denmark)

    Krüger, Johannes; Kjær, Kurt H.; Schomacker, Anders

    2010-01-01

    Kötlujökull transports considerable amounts of supraglacial debris at its snout because of frontal oscillations with frequent ice advances followed by ice-margin stagnation. Kötlujökull provides suitable conditions of studying dead-ice melting and landscape formation in a debris-charged lowland...... glacier environment. The scientific challenges are to answer the key questions. What are the conditions for dead-ice formation? From which sources does the sediment cover originate? Which melting and reworking processes act in the ice-cored moraines? What is the rate of de-icing in the ice-cored moraines...... under humid, sub-polar conditions? Does this rate differ from rates reported from polar environments of dry continental nature? How will the sedimentary architecture appear in the geological record? How will the final landsystem appear? These key questions are answered in a review of research...

  10. Autonomous Aerial Ice Observation for Ice Defense

    Directory of Open Access Journals (Sweden)

    Joakim Haugen

    2014-10-01

    Full Text Available One of the tasks in ice defense is to gather information about the surrounding ice environment using various sensor platforms. In this manuscript we identify two monitoring tasks known in literature, namely dynamic coverage and target tracking, and motivate how these tasks are relevant in ice defense using RPAS. An optimization-based path planning concept is outlined for solving these tasks. A path planner for the target tracking problem is elaborated in more detail and a hybrid experiment, which consists of both a real fixed-wing aircraft and simulated objects, is included to show the applicability of the proposed framework.

  11. Pigment identification on "Pietà" of Barletta, example of Renaissance Apulian sculpture: a Raman microscopy study.

    Science.gov (United States)

    Marano, D; Catalano, I M; Monno, A

    2006-08-01

    A study of the original painting layer of the "Pietà" of Barletta, a polychrome statue, important example of Renaissance Apulian sculpture, was performed by mu-Raman spectroscopy. Vermilion was identified in the original layer of the blood drops on Jesus knee. Lazurite was identified as the original blue pigment on Our Lady's veil and lace, currently a yellow ochre-like color. The use of lazurite demonstrates the historical-artistic importance of this polychrome statue, and supports the hypothesis that this artwork was probably commissioned by Our Lady's devotees to itinerant artists inspired by the more precious Vesperbilder model.

  12. Land Ice: Greenland & Antarctic ice mass anomaly

    Data.gov (United States)

    National Aeronautics and Space Administration — Data from NASA's Grace satellites show that the land ice sheets in both Antarctica and Greenland are losing mass. The continent of Antarctica (left chart) has been...

  13. Ice cream structure modification by ice-binding proteins.

    Science.gov (United States)

    Kaleda, Aleksei; Tsanev, Robert; Klesment, Tiina; Vilu, Raivo; Laos, Katrin

    2018-04-25

    Ice-binding proteins (IBPs), also known as antifreeze proteins, were added to ice cream to investigate their effect on structure and texture. Ice recrystallization inhibition was assessed in the ice cream mixes using a novel accelerated microscope assay and the ice cream microstructure was studied using an ice crystal dispersion method. It was found that adding recombinantly produced fish type III IBPs at a concentration 3 mg·L -1 made ice cream hard and crystalline with improved shape preservation during melting. Ice creams made with IBPs (both from winter rye, and type III IBP) had aggregates of ice crystals that entrapped pockets of the ice cream mixture in a rigid network. Larger individual ice crystals and no entrapment in control ice creams was observed. Based on these results a model of ice crystals aggregates formation in the presence of IBPs was proposed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Fabrication of graded helical square tower-like Mn sculptured thin films and investigation of their electrical properties: comparison with perturbation theory

    Science.gov (United States)

    Fakharpour, Mahsa; Savaloni, Hadi

    2017-06-01

    Mn sculptured thin films were fabricated in form of graded helical square tower-like terraced sculptured Mn thin films (GHSTTS) using oblique angle deposition together with rotation of substrate about its surface normal with fixed rotation angle (90°) and a shadowing block which was fixed at the centre of the substrate holder. The anisotropy of the samples was examined by resistivity measurements at two orthogonal angles. Direct relationship is obtained between resistivity and the anisotropy of the produced samples which showed that both of these parameters increase with decreasing distance from the edge of the shadowing block. Simulation work using the perturbation theory produced results consistent with the experimental observations.

  15. "Petit Granit": a Belgian limestone used in heritage, construction and sculpture.

    Science.gov (United States)

    Pereira, Dolores; Touneur, Francis; Bernáldez, Lorenzo; García Blázguez, Ana

    2014-05-01

    "Petit Granit" is a Lower Carboniferous (Tournaisian) grey-bluish crinoidal limestone that becomes shiny black when polished. The rock is known under several other names like Pierre Bleue (Blue Stone), but at the same time it should not be confused with other natural stones having a similar commercial name (e.g. Chinese Bluestone or Irish Bluestone) which are superficially similar limestones. It consists of around 96% microcrystalline calcite and a high proportion of fossils, mainly crinoids. In addition some dolomite, quartz, pyrite, marcasite and fluorite are present. Around fifteen quarries are active these days, employing almost one thousand people and thus is an important part of the natural stone economy in Belgium. "Petit Granit" has an Appellation d'Origine Locale (Local Appellation of Origin) designation since 1999. It has been extracted in several regions of South Belgium since the Middle Ages. In a sense the name is misleading because it is not an igneous rock and therefore not a true granite, but it derives from the profusion of numerous white fossil fragments in a dark carbonaceous matrix which look similar to feldspar crystals in a granitic background. The stone characterizes many façades of the urban architecture of Brussels and other Belgian cities, and since the second half of the 19th century it has been used in various countries in Europe and overseas. Its high density and uniformity mean that it takes an excellent polish and thus has versatile use as a dimension stone. "Petit Granit" has also been used widely in sculpture and architecture by several well known artists (e.g. Mateo Hernández, Michel Smolders, Tom Blatt, Elise Delbrassinne, Benoît Luyckx, Santiago Calatrava, among others). However, deterioration has been observed when it has been used for exterior purposes, and appropriate measures need to be taken to prevent this. This stone can be considered as Global Heritage Stone Resource in Europe, for both its use in construction and for

  16. The materials and techniques used in a baroque sculpture representing Saint Dominic from the Museum of Santa Maria de Lamas

    Directory of Open Access Journals (Sweden)

    Carolina Barata

    2007-01-01

    Full Text Available A polychrome wooden sculpture from the Museum of Santa Maria de Lamas (Northern Portugal, representing the image of Saint Dominic, produced in the first half of the 18th century, was studied for the identification of the materials and techniques employed in its fine modelling. Radiography was used for the study of the construction details of the wooden support, optical microscopy (OM and polarized light microscopy (PLM for the characterization of the paint layers and energy dispersive X-ray spectrometry (EDXRF, Fourier transform infrared spectroscopy (FTIR and microchemical tests for the identification of pigments and fillers.The identified materials were common to the period when the sculpture was made: gypsum, gold leaf, bole,white lead, brown ochre, vermillion, a black pigment made of carbon (possibly mixed with verdigris, used as a drier, a red lake and a calcium compound used as filler. However, regarding the techniques employed, and probably due to economic reasons, it seems that the recommended practice in art treatises and working contracts was not completely followed in what concerns the ground layers. Similar reasons appear to have caused the use of white lead mixed with a calcium compound, as a filler, in the less expressive areas, and should explain the fact that the estofado techniques (simulation of brocaded vestment have been limited to the visible areas at the front.

  17. Can AFLP genome scans detect small islands of differentiation? The case of shell sculpture variation in the periwinkle Echinolittorina hawaiiensis.

    Science.gov (United States)

    Tice, K A; Carlon, D B

    2011-08-01

    Genome scans have identified candidate regions of the genome undergoing selection in a wide variety of organisms, yet have rarely been applied to broadly dispersing marine organisms experiencing divergent selection pressures, where high recombination rates can reduce the extent of linkage disequilibrium (LD) and the ability to detect genomic regions under selection. The broadly dispersing periwinkle Echinolittorina hawaiiensis exhibits a heritable shell sculpture polymorphism that is correlated with environmental variation. To elucidate the genetic basis of phenotypic variation, a genome scan using over 1000 AFLP loci was conducted on smooth and sculptured snails from divergent habitats at four replicate sites. Approximately 5% of loci were identified as outliers with Dfdist, whereas no outliers were identified by BayeScan. Closer examination of the Dfdist outliers supported the conclusion that these loci were false positives. These results highlight the importance of controlling for Type I error using multiple outlier detection approaches, multitest corrections and replicate population comparisons. Assuming shell phenotypes have a genetic basis, our failure to detect outliers suggests that the life history of the target species needs to be considered when designing a genome scan. © 2011 The Authors. Journal of Evolutionary Biology © 2011 European Society For Evolutionary Biology.

  18. Ice and ocean velocity in the Arctic marginal ice zone: Ice roughness and momentum transfer

    Directory of Open Access Journals (Sweden)

    Sylvia T. Cole

    2017-09-01

    Full Text Available The interplay between sea ice concentration, sea ice roughness, ocean stratification, and momentum transfer to the ice and ocean is subject to seasonal and decadal variations that are crucial to understanding the present and future air-ice-ocean system in the Arctic. In this study, continuous observations in the Canada Basin from March through December 2014 were used to investigate spatial differences and temporal changes in under-ice roughness and momentum transfer as the ice cover evolved seasonally. Observations of wind, ice, and ocean properties from four clusters of drifting instrument systems were complemented by direct drill-hole measurements and instrumented overhead flights by NASA operation IceBridge in March, as well as satellite remote sensing imagery about the instrument clusters. Spatially, directly estimated ice-ocean drag coefficients varied by a factor of three with rougher ice associated with smaller multi-year ice floe sizes embedded within the first-year-ice/multi-year-ice conglomerate. Temporal differences in the ice-ocean drag coefficient of 20–30% were observed prior to the mixed layer shoaling in summer and were associated with ice concentrations falling below 100%. The ice-ocean drag coefficient parameterization was found to be invalid in September with low ice concentrations and small ice floe sizes. Maximum momentum transfer to the ice occurred for moderate ice concentrations, and transfer to the ocean for the lowest ice concentrations and shallowest stratification. Wind work and ocean work on the ice were the dominant terms in the kinetic energy budget of the ice throughout the melt season, consistent with free drift conditions. Overall, ice topography, ice concentration, and the shallow summer mixed layer all influenced mixed layer currents and the transfer of momentum within the air-ice-ocean system. The observed changes in momentum transfer show that care must be taken to determine appropriate parameterizations

  19. Sea Ice Index, Version 3

    Data.gov (United States)

    National Aeronautics and Space Administration — The Sea Ice Index provides a quick look at Arctic- and Antarctic-wide changes in sea ice. It is a source for consistent, up-to-date sea ice extent and concentration...

  20. Non-destructive Investigation of "The Violinist" a Lead Sculpture by Pablo Gargallo, Using the Neutron Imaging Facility NEUTRA in the Paul Scherrer Institute

    Science.gov (United States)

    Masalles, Alex; Lehmann, Eberhard; Mannes, David

    The Violinist (1920), the only sculpture made by Gargallo using lead sheet and wood, is being corroded by carbonation, most probably due to the organic vapours released by the wood inside, a material not chemically compatible with lead. Hydrogen plasma has been tested and proved to be an effective treatment meaning that the sculpture has to be dismantled in order to give the plasma gas access to the lead carbonate crusts on the inner surface of the lead sheet. Prior to dismantling, a complete exploration and diagnosis of this lead sculpture has been carried out through neutron imaging at the Paul Scherrer Institute. This non-destructive technique has produced different sets of images including radiography, tomography and 3D reconstruction. Despite the presence of a core made of an organic material such as wood, the digital processing of the images and their in depth visual analysis have yielded new three-dimensional information of inaccessible details of the sculpture, allowing us to assess its present state of conservation and the manufacturing technique and materials used by the artist. The results presented in this article highlight how information from neutron imaging can be of great value when it comes to set the strategies for future conservation treatment

  1. Review of ‘Sculpture Victorious: Art in an Age of Invention, 1837–1901’ at Tate Britain, 25 February to 25 May 2015

    Directory of Open Access Journals (Sweden)

    Clare Walker Gore

    2016-06-01

    Full Text Available This article reviews the exhibition ‘Sculpture Victorious’, which ran at Tate Britain from 25 February to 25 May 2015. It describes the exhibition, considers the curators’ approach in the wider context of nineteenth-century studies, and assesses its implications for the field.

  2. Computer Instructional Approach and Students' Creative Ability in Sculpture Education in Nigeria Universities: Obafemi Awolowo University as a Case Study

    Science.gov (United States)

    Abass, Bada Tayo

    2011-01-01

    This paper assessed the use of computer assisted instruction in enhancing students' creative ability in sculpture education in Obafemi Awolowo University, Ile-Ife. The study adopted non- randomized pretest, posttest control group. Data were analyzed using mean, standard deviation and analysis of Covariance (ANCOVA). The mean score were used in…

  3. Beating the wavelength limit: three-dimensional imaging of buried subwavelength fractures in sculpture and construction materials by terahertz time-domain reflection spectroscopy.

    Science.gov (United States)

    Schwerdtfeger, M; Castro-Camus, E; Krügener, K; Viöl, W; Koch, M

    2013-01-20

    We use reflection terahertz spectroscopy to locate and produce three-dimensional images of air gaps between stones that resemble fractures, even of subwavelength thicknesses. This technique is found to be promising tool for sculpture and building damage evaluation as well as structural quality control in other dielectric materials.

  4. Rheology of glacier ice

    Science.gov (United States)

    Jezek, K. C.; Alley, R. B.; Thomas, R. H.

    1985-01-01

    A new method for calculating the stress field in bounded ice shelves is used to compare strain rate and deviatoric stress on the Ross Ice Shelf, Antarctica. The analysis shows that strain rate (per second) increases as the third power of deviatoric stress (in newtons/sq meter), with a constant of proportionality equal to 2.3 x 10 to the -25th.

  5. Sputtering of water ice

    DEFF Research Database (Denmark)

    Baragiola, R.A.; Vidal, R.A.; Svendsen, W.

    2003-01-01

    We present results of a range of experiments of sputtering of water ice together with a guide to the literature. We studied how sputtering depends on the projectile energy and fluence, ice growth temperature, irradiation temperature and external electric fields. We observed luminescence from...

  6. Academic Airframe Icing Perspective

    Science.gov (United States)

    Bragg, Mike; Rothmayer, Alric; Thompson, David

    2009-01-01

    2-D ice accretion and aerodynamics reasonably well understood for engineering applications To significantly improve our current capabilities we need to understand 3-D: a) Important ice accretion physics and modeling not well understood in 3-D; and b) Aerodynamics unsteady and 3-D especially near stall. Larger systems issues important and require multidisciplinary team approach

  7. Making an Ice Core.

    Science.gov (United States)

    Kopaska-Merkel, David C.

    1995-01-01

    Explains an activity in which students construct a simulated ice core. Materials required include only a freezer, food coloring, a bottle, and water. This hands-on exercise demonstrates how a glacier is formed, how ice cores are studied, and the nature of precision and accuracy in measurement. Suitable for grades three through eight. (Author/PVD)

  8. Ice sheet in peril

    DEFF Research Database (Denmark)

    Hvidberg, Christine Schøtt

    2016-01-01

    Earth's large ice sheets in Greenland and Antarctica are major contributors to sea level change. At present, the Greenland Ice Sheet (see the photo) is losing mass in response to climate warming in Greenland (1), but the present changes also include a long-term response to past climate transitions...

  9. Sunlight, Sea Ice, and the Ice Albedo Feedback in a Changing Arctic Sea Ice Cover

    Science.gov (United States)

    2015-09-30

    Figure 1). When the ice is snow covered there is little difference in albedo and partitioning between first year and multiyear ice. Once the snow melts...1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Sunlight, Sea Ice, and the Ice Albedo Feedback in a...and iv) onset dates of melt and freeze up. 4. Assess the magnitude of the contribution from ice- albedo feedback to the observed decrease of sea ice

  10. Sunlight, Sea Ice, and the Ice Albedo Feedback in a Changing Artic Sea Ice Cover

    Science.gov (United States)

    2015-11-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. SUNLIGHT, SEA ICE , AND THE ICE ALBEDO FEEDBACK IN A...iv) onset dates of melt and freeze up. 4. Assess the magnitude of the contribution from ice - albedo feedback to the observed decrease of sea ice in... sea ice prediction and modeling community to improve the treatment of solar radiation and the ice - albedo feedback. This transfer will take the form of

  11. GLERL Radiation Transfer Through Freshwater Ice

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Radiation transmittance (ratio of transmitted to incident radiation) through clear ice, refrozen slush ice and brash ice, from ice surface to ice-water interface in...

  12. Modelling snow ice and superimposed ice on landfast sea ice in Kongsfjorden, Svalbard

    Directory of Open Access Journals (Sweden)

    Caixin Wang

    2015-08-01

    Full Text Available Snow ice and superimposed ice formation on landfast sea ice in a Svalbard fjord, Kongsfjorden, was investigated with a high-resolution thermodynamic snow and sea-ice model, applying meteorological weather station data as external forcing. The model shows that sea-ice formation occurs both at the ice bottom and at the snow/ice interface. Modelling results indicated that the total snow ice and superimposed ice, which formed at the snow/ice interface, was about 14 cm during the simulation period, accounting for about 15% of the total ice mass and 35% of the total ice growth. Introducing a time-dependent snow density improved the modelled results, and a time-dependent oceanic heat flux parameterization yielded reasonable ice growth at the ice bottom. Model results suggest that weather conditions, in particular air temperature and precipitation, as well as snow thermal properties and surface albedo are the most critical factors for the development of snow ice and superimposed ice in Kongsfjorden. While both warming air and higher precipitation led to increased snow ice and superimposed ice forming in Kongsfjorden in the model runs, the processes were more sensitive to precipitation than to air temperature.

  13. Co-occurrence of linear and circular dichroism in chiral sculptured ZrO2 thin films

    Science.gov (United States)

    Muhammad, Zahir; Wali, Faiz; Song, Li

    2018-01-01

    Three dimensional chiral metamaterials, have unique helical shaped morphologies and periodically varying permittivity, possess inherent fascinatingly chiroptical activity in developing potential photonic applications. Herein, we demonstrate a systemic simulations of optical activity in chiral sculptured thin films (CSTFs) made of ZrO2 . In particular, a circular dichroism (CD) and linear dichroism (LD) are scrutinized for the proposed ZrO2 CSTFs. From the calculated differential absorption, LD and CD spectrum is computed using linear and circular polarized light beams respectively. The signated mode of different peaks for LD and CD is observed at different sweep angles with a large LD effect. Moreover, the CD diminishes at large sweep angle. This finding strongly indicates high potential of our proposed helical ZrO2 nanostructures as a perfect polarization converter. Simultaneously, optical remittance of different helical nanostructures are also compared.

  14. Surface enhanced Raman spectroscopy and structural characterization of Ag/Cu chiral nano-flower sculptured thin films

    International Nuclear Information System (INIS)

    Savaloni, Hadi; Babaei, Reza

    2013-01-01

    Silver chiral nano-flower sculptured thin films with 3-, 4- and 5-fold symmetry were produced on copper substrates using oblique angle deposition method in conjunction with rotation of sample holder with different speeds at different sectors of each revolution corresponding to symmetry order of the acquired nano-flower. Atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM) were employed to obtain morphologies and nano-structure of the films. Raman spectroscopy was performed on all samples that were subject to impregnation by 4,4′-bipyridine (C 10 H 8 N 2 ) solution. A high degree of enhancement of the main bands at 1610, 1297, and 1009 cm −1 that can be assigned to the C=C stretching mode, aromatic ring stretching ring and in-plane ring mode of 4,4′-bipyridine, is achieved.

  15. Surface enhanced Raman spectroscopy and structural characterization of Ag/Cu chiral nano-flower sculptured thin films

    Energy Technology Data Exchange (ETDEWEB)

    Savaloni, Hadi, E-mail: savaloni@khayam.ut.ac.ir [Department of Physics, University of Tehran, North-Kargar Street, Tehran (Iran, Islamic Republic of); Babaei, Reza, E-mail: reza_babaee_62@yahoo.com [Department of Physics, Islamic Azad University, Science and Research Branch, Tehran (Iran, Islamic Republic of)

    2013-09-01

    Silver chiral nano-flower sculptured thin films with 3-, 4- and 5-fold symmetry were produced on copper substrates using oblique angle deposition method in conjunction with rotation of sample holder with different speeds at different sectors of each revolution corresponding to symmetry order of the acquired nano-flower. Atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM) were employed to obtain morphologies and nano-structure of the films. Raman spectroscopy was performed on all samples that were subject to impregnation by 4,4′-bipyridine (C{sub 10}H{sub 8}N{sub 2}) solution. A high degree of enhancement of the main bands at 1610, 1297, and 1009 cm{sup −1} that can be assigned to the C=C stretching mode, aromatic ring stretching ring and in-plane ring mode of 4,4′-bipyridine, is achieved.

  16. Terracotta polychrome sculptures examined before and after their conservation work: contributions from non-invasive in situ analytical techniques.

    Science.gov (United States)

    Colombo, C; Bevilacqua, F; Brambilla, L; Conti, C; Realini, M; Striova, J; Zerbi, G

    2011-08-01

    The potential of non-invasive in situ analytical techniques such as portable Raman, portable X-ray fluorescence, portable optical microscope and fibre optics reflectance spectroscopy has been shown studying painted layers of Renaissance terracotta polychrome sculptures belonging to the statuary of Santo Sepolcro Church in Milan. The results obtained allowed pointing out the contribution of these techniques to the compositional diagnostic, providing complete information, in some cases, better than micro-destructive techniques, on the kind of pigments used on the external painted layers. Moreover, a comparison with the results obtained before the last conservation work (2009) with micro-destructive techniques allowed ascertaining the removal of the external painted layers during the conservation operations.

  17. High Speed Ice Friction

    Science.gov (United States)

    Seymour-Pierce, Alexandra; Sammonds, Peter; Lishman, Ben

    2014-05-01

    Many different tribological experiments have been run to determine the frictional behaviour of ice at high speeds, ostensibly with the intention of applying results to everyday fields such as winter tyres and sports. However, experiments have only been conducted up to linear speeds of several metres a second, with few additional subject specific studies reaching speeds comparable to these applications. Experiments were conducted in the cold rooms of the Rock and Ice Physics Laboratory, UCL, on a custom built rotational tribometer based on previous literature designs. Preliminary results from experiments run at 2m/s for ice temperatures of 271 and 263K indicate that colder ice has a higher coefficient of friction, in accordance with the literature. These results will be presented, along with data from further experiments conducted at temperatures between 259-273K (in order to cover a wide range of the temperature dependent behaviour of ice) and speeds of 2-15m/s to produce a temperature-velocity-friction map for ice. The effect of temperature, speed and slider geometry on the deformation of ice will also be investigated. These speeds are approaching those exhibited by sports such as the luge (where athletes slide downhill on an icy track), placing the tribological work in context.

  18. Synchronizing ice cores from the Renland and Agassiz ice caps to the Greenland Ice Core Chronology

    DEFF Research Database (Denmark)

    Vinther, Bo Møllesøe; Clausen, Henrik Brink; Fischer, D. A.

    2008-01-01

    Four ice cores from the Agassiz ice cap in the Canadian high arctic and one ice core from the Renland ice cap in eastern Greenland have been synchronized to the Greenland Ice Core Chronology 2005 (GICC05) which is based on annual layer counts in the DYE-3, GRIP and NGRIP ice cores. Volcanic....... Annual layer thicknesses in the Agassiz ice cores point to a well-developed Raymond bump in the Agassiz ice cap....... reference horizons, seen in electrical conductivity measurements (ECM) have been used to carry out the synchronization throughout the Holocene. The Agassiz ice cores have been matched to the NGRIP ice core ECM signal, while the Renland core has been matched to the GRIP ice core ECM signal, thus tying...

  19. Initial Cooling Experiment (ICE)

    CERN Multimedia

    Photographic Service; CERN PhotoLab

    1978-01-01

    In 1977, in a record-time of 9 months, the magnets of the g-2 experiment were modified and used to build a proton/antiproton storage ring: the "Initial Cooling Experiment" (ICE). It served for the verification of the cooling methods to be used for the "Antiproton Project". Stochastic cooling was proven the same year, electron cooling followed later. Also, with ICE the experimental lower limit for the antiproton lifetime was raised by 9 orders of magnitude: from 2 microseconds to 32 hours. For its previous life as g-2 storage ring, see 7405430. More on ICE: 7711282, 7809081, 7908242.

  20. Wave-ice Interaction and the Marginal Ice Zone

    Science.gov (United States)

    2015-09-30

    single buoys that were moved from place to place. These new data, obtained within the comprehensive set of ocean, ice and atmosphere sensors and remote...1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Wave- ice interaction and the Marginal Ice Zone Prof...between ocean waves and a sea ice cover, in terms, of scattering, attenuation, and mechanical effect of the waves on the ice . OBJECTIVES The

  1. Creep of ice: further studies

    International Nuclear Information System (INIS)

    Heard, H.C.; Durham, W.B.; Kirby, S.H.

    1987-01-01

    Detailed studies have been done of ice creep as related to the icy satellites, Ganymede and Callisto. Included were: (1) the flow of high-pressure water ices II, III, and V, and (2) frictional sliding of ice I sub h. Work was also begun on the study of the effects of impurities on the flow of ice. Test results are summarized

  2. Vortex ice in nanostructured superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Reichhardt, Charles [Los Alamos National Laboratory; Reichhardt, Cynthia J [Los Alamos National Laboratory; Libal, Andras J [Los Alamos National Laboratory

    2008-01-01

    We demonstrate using numerical simulations of nanostructured superconductors that it is possible to realize vortex ice states that are analogous to square and kagome ice. The system can be brought into a state that obeys either global or local ice rules by applying an external current according to an annealing protocol. We explore the breakdown of the ice rules due to disorder in the nanostructure array and show that in square ice, topological defects appear along grain boundaries, while in kagome ice, individual defects appear. We argue that the vortex system offers significant advantages over other artificial ice systems.

  3. Web life: Ice Flows

    Science.gov (United States)

    2016-11-01

    Computer and video gamers of a certain vintage will have fond memories of Lemmings, a game in which players must shepherd pixelated, suicidal rodents around a series of obstacles to reach safety. At first glance, Ice Flows is strikingly similar.

  4. Ice Engineering Research Area

    Data.gov (United States)

    Federal Laboratory Consortium — Refrigerated Physical Modeling of Waterways in a Controlled EnvironmentThe Research Area in the Ice Engineering Facility at the Cold Regions Research and Engineering...

  5. Islands in the ice

    DEFF Research Database (Denmark)

    Jørgensen, Tina; Kjær, Kurt H.; Haile, James Seymour

    2012-01-01

    Nunataks are isolated bedrocks protruding through ice sheets. They vary in age, but represent island environments in 'oceans' of ice through which organism dispersals and replacements can be studied over time. The J.A.D. Jensen's Nunataks at the southern Greenland ice sheet are the most isolated...... nunataks on the northern hemisphere - some 30 km from the nearest biological source. They constitute around 2 km(2) of ice-free land that was established in the early Holocene. We have investigated the changes in plant composition at these nunataks using both the results of surveys of the flora over...... the last 130 years and through reconstruction of the vegetation from the end of the Holocene Thermal Maximum (5528 ± 75 cal year BP) using meta-barcoding of plant DNA recovered from the nunatak sediments (sedaDNA). Our results show that several of the plant species detected with sedaDNA are described from...

  6. Dead-ice environments

    DEFF Research Database (Denmark)

    Krüger, Johannes; Kjær, Kurt H.; Schomacker, Anders

    2010-01-01

    Kötlujökull transports considerable amounts of supraglacial debris at its snout because of frontal oscillations with frequent ice advances followed by ice-margin stagnation. Kötlujökull provides suitable conditions of studying dead-ice melting and landscape formation in a debris-charged lowland...... under humid, sub-polar conditions? Does this rate differ from rates reported from polar environments of dry continental nature? How will the sedimentary architecture appear in the geological record? How will the final landsystem appear? These key questions are answered in a review of research...... and conclusions on dead-ice melting and landscape formation from Kötlujökull. Processes and landform-sediment associations are linked to the current climate and glacier–volcano interaction....

  7. Global ice sheet modeling

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, T.J.; Fastook, J.L. [Univ. of Maine, Orono, ME (United States). Institute for Quaternary Studies

    1994-05-01

    The University of Maine conducted this study for Pacific Northwest Laboratory (PNL) as part of a global climate modeling task for site characterization of the potential nuclear waste respository site at Yucca Mountain, NV. The purpose of the study was to develop a global ice sheet dynamics model that will forecast the three-dimensional configuration of global ice sheets for specific climate change scenarios. The objective of the third (final) year of the work was to produce ice sheet data for glaciation scenarios covering the next 100,000 years. This was accomplished using both the map-plane and flowband solutions of our time-dependent, finite-element gridpoint model. The theory and equations used to develop the ice sheet models are presented. Three future scenarios were simulated by the model and results are discussed.

  8. Global ice sheet modeling

    International Nuclear Information System (INIS)

    Hughes, T.J.; Fastook, J.L.

    1994-05-01

    The University of Maine conducted this study for Pacific Northwest Laboratory (PNL) as part of a global climate modeling task for site characterization of the potential nuclear waste respository site at Yucca Mountain, NV. The purpose of the study was to develop a global ice sheet dynamics model that will forecast the three-dimensional configuration of global ice sheets for specific climate change scenarios. The objective of the third (final) year of the work was to produce ice sheet data for glaciation scenarios covering the next 100,000 years. This was accomplished using both the map-plane and flowband solutions of our time-dependent, finite-element gridpoint model. The theory and equations used to develop the ice sheet models are presented. Three future scenarios were simulated by the model and results are discussed

  9. Ice Cream Stick Math.

    Science.gov (United States)

    Paddock, Cynthia

    1992-01-01

    Described is a teaching technique which uses the collection of ice cream sticks as a means of increasing awareness of quantity in a self-contained elementary special class for students with learning disabilities and mild mental retardation. (DB)

  10. Electrical Properties of Ice

    Science.gov (United States)

    1993-08-01

    carriers in ice. T U] P2 P3 PU4 (00C (m2 V s) (m21V S) (M21V s) (m2/V s) Method used Reference -13 to -36 (1.1±O..1)xl0𔄁 Analysis of Kunst and...Chapter 18. In Ice, 2nd ed., vol. 2. Amsterdam: North Holland Publishing Co., p. 783-7 99 . Kunst , M. and J. Warnan (1983) Nanosecond time-resolved

  11. Her Excellency Mrs Sarah Gillett Her Majesty's Ambassador to the Swiss Confederation United Kingdom of Great Britain and Northern Ireland on the occasion of the Antony Gormley sculpture unveiling ceremony Wednesday 7th December 2011

    CERN Multimedia

    Maximilien Brice

    2011-01-01

    Her Excellency Mrs Sarah Gillett Her Majesty's Ambassador to the Swiss Confederation United Kingdom of Great Britain and Northern Ireland on the occasion of the Antony Gormley sculpture unveiling ceremony Wednesday 7th December 2011

  12. Ice slurry accumulation

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, K.G.; Kauffeld, M.

    1998-06-01

    More and more refrigeration systems are designed with secondary loops, thus reducing the refrigerant charge of the primary refrigeration plant. In order not to increase energy consumption by introducing a secondary refrigerant, alternatives to the well established single phase coolants (brines) and different concepts of the cooling plant have to be evaluated. Combining the use of ice-slurry - mixture of water, a freezing point depressing agent (antifreeze) and ice particles - as melting secondary refrigerant and the use of a cool storage makes it possible to build plants with secondary loops without increasing the energy consumption and investment. At the same time the operating costs can be kept at a lower level. The accumulation of ice-slurry is compared with other and more traditional storage systems. The method is evaluated and the potential in different applications is estimated. Aspects of practically use of ice-slurry has been examined in the laboratory at the Danish Technological Institute (DTI). This paper will include the final conclusions from this work concerning tank construction, agitator system, inlet, outlet and control. The work at DTI indicates that in some applications systems with ice-slurry and accumulation tanks have a great future. These applications are described by a varying load profile and a process temperature suiting the temperature of ice-slurry (-3 - -8/deg. C). (au)

  13. Ice recrystallization inhibition in ice cream by propylene glycol monostearate.

    Science.gov (United States)

    Aleong, J M; Frochot, S; Goff, H D

    2008-11-01

    The effectiveness of propylene glycol monostearate (PGMS) to inhibit ice recrystallization was evaluated in ice cream and frozen sucrose solutions. PGMS (0.3%) dramatically reduced ice crystal sizes in ice cream and in sucrose solutions frozen in a scraped-surface freezer before and after heat shock, but had no effect in quiescently frozen solutions. PGMS showed limited emulsifier properties by promoting smaller fat globule size distributions and enhanced partial coalescence in the mix and ice cream, respectively, but at a much lower level compared to conventional ice cream emulsifier. Low temperature scanning electron microscopy revealed highly irregular crystal morphology in both ice cream and sucrose solutions frozen in a scraped-surface freezer. There was strong evidence to suggest that PGMS directly interacts with ice crystals and interferes with normal surface propagation. Shear during freezing may be required for its distribution around the ice and sufficient surface coverage.

  14. PATHOS – the bodies of Christ on the Cross. Rhetoric of suffering in wooden sculpture found in Portugal, twelfth-fourteenth centuries. A few examples

    Directory of Open Access Journals (Sweden)

    Fernandes, Carla Varela

    2013-11-01

    Full Text Available In Portuguese medieval art, freestanding wooden sculptures representing Christ on the Cross are among the less studied typologies. For this reason, it is important to discuss and question some of the most representative works of aesthetic values and/or iconographic models that characterised this European production between the twelfth and fourteenth centuries. The option for the Christus patiens typology is justified by the fact that it includes a large number of sculptures, some still requiring analysis and reflection, with the possibility of bringing to light new elements through fresh comparisons or using laboratory-based findings. The examples analysed here demonstrate the existence of artistic models reflecting the importance offoreign formal and iconographic references, which in turn raise the issues of the import and/or reinterpretation by Portuguese sculptors of these ideas, and of the itinerancy of foreign sculptors through Portugal, locating this corpus within an international historiographical discussion.

  15. Characteristics of ice, needed for ice loadings determination

    Directory of Open Access Journals (Sweden)

    Polit’ko Valentin Aleksandrovich

    2015-12-01

    Full Text Available In order to determine ice loads on the offshore oil and gas structures different ice information is required as an input data. At the present moment there is no unified generally recognized methodology for estimating ice loads and set the main ice parameters. In this relation there appears a question of the ice parameters which need to be investigated. The article attempts to analyze a variety of sources, including standards, on the subject of collection of ice information, required and sufficient for the calculation of ice loads. The article presents the basic steps in the planning of ice information collection, the list of main characteristics and parameters of ice, modern methods of observations and direct measurements of the ice, as well as the ways in which the field tests data of physical and mechanical properties of ice is processed. Particular attention is paid to the anisotropy of ice, integrated assessment of the strength of the ice field, as well as the variability of meteorological conditions.

  16. Ice flow Modelling of the Greenland Ice Sheet

    DEFF Research Database (Denmark)

    Nielsen, Lisbeth Tangaa

    Models of ice flow have a range of application in glaciology, including investigating the large-scale response of ice sheets to changes in climate, assimilating data to estimate unknown conditions beneath the ice sheet, and in interpreting proxy records obtained from ice cores, among others. In t...... a steady state with respect to the reference climate at the end of the simulation and that the mass balance of the ice sheet at this time was more sensitive to recent climate fluctuations than the temperature forcing in the early or mid-Holocene.......Models of ice flow have a range of application in glaciology, including investigating the large-scale response of ice sheets to changes in climate, assimilating data to estimate unknown conditions beneath the ice sheet, and in interpreting proxy records obtained from ice cores, among others....... In this PhD project, the use of ice flow models for the interpretation of the age-structure of the Greenland ice sheet, i.e. the depth within the ice, at which ice deposited at given times are found at present day. Two different observational data sets of this archive were investigated. Further, paleo...

  17. Pyro-expanded black slate in sculptural art Ardósia piroexpandida em arte escultórica

    Directory of Open Access Journals (Sweden)

    J. C. e Costa

    2013-03-01

    Full Text Available Black slate transformed through a pyroplastic process named pyro-expansion or exfoliation has been explored in the present work in order to be used as sculptural material. Black slate is a highly fissile, fine grained and organic matter rich rock that is the product of the action of low-grade regional metamorphism on black shale (a sedimentary clay and organic matter rich, also fissile and fine grained rock. Black slate if fired at an adequate firing rate up to the temperature range 1000 ºC-1240 ºC shows great potential for the manufacture of sculptural pieces. The technical possibilities of the shaping or conformation of pyro-expanded black slate have also been studied, including the reactions that take place when two different black slate pieces are closely associated with each other, or when black slate pieces are closely associated to other materials, such as metals and ceramics. These interactions, while associating different materials that react with each other, emphasize the unique characteristics of new sculptural compositions increasing the plastic capacities of the pyro-expanded black slate. Some examples of the associations referred to will be shown, which highlight the close functional relationship between art and science; research involves the approach to new techniques and materials, looking at the development of unique plastic configurations.No presente artigo são divulgados os resultados da investigação do comportamento para fins escultóricos da ardósia (rocha de cor negra, granularidade fina e clivagem fina que resulta da acção de metamorfismo regional de baixo grau sobre rocha sedimentar, argilito laminado rico em matéria orgânica transformada piroplasticamente. O material resultante é denominado ardósia piro-expandida ou exfoliada, depois da ardósia natural ser tratada termicamente a temperaturas até 1000 °C-1240 ºC. A investigação subjacente fez uso e desenvolveu conhecimentos do domínio da geologia, mais

  18. EDXRF portable system used in the analysis of altars, sculptures and paintings from XVII and XVIII centuries in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, R.P. [Nuclear Instrumentation Laboratory, COPPE/UFRJ, Rio de Janeiro, RJ (Brazil); CEFETEQ, Rio de Janeiro, RJ (Brazil); Calza, C.; Lopes, R.T., E-mail: ccalza@lin.ufrj.br [Nuclear Instrumentation Laboratory, COPPE/UFRJ, Rio de Janeiro, RJ (Brazil); Santos, R.O. [RG Conservation and Restoration, Rio de Janeiro, RJ (Brazil)

    2011-07-01

    Full text: The preservation of cultural heritage has acquired increasing interest in the last decades and many scientific techniques have been employed to analyze paintings, manuscripts, ceramics, glasses, statues, coins and metal artifacts in order to solve problems related to restoration, conservation, dating and attribution of artworks. There is also an increasing trend for non-destructive investigations since most of the samples are unique and precious objects of art and archaeology. X-Ray fluorescence (XRF) is the most widely used investigative technique in the field of archaeometry, due to a number of favorable analytical characteristics, such as multielemental and non-destructive analysis, high sensitivity and applicability to a wide range of samples. In this work, XRF was used to analyze altars, sculptures and paintings in the Saint Anthony Convent (Rio de Janeiro, Brazil). The cornerstone of this convent was launched in 1608, by the Franciscan friars, and the construction of the church was finished in 1620. The Saint Anthony sculpture in the main altar is one of the few remaining pieces from the XVII century in Rio de Janeiro. The splendid Baroque carvings of the chapel, covered with integral gilding, in the national Portuguese style, dates from 1716 to 1719. The results obtained during the analyses have been used in the meticulous process of restoration, developed in the last two years, in order to recover the original splendour of this important piece of our cultural heritage. The analyses were carried out with an EDXRF portable system developed in the Nuclear Instrumentation Laboratory, consisting of an X-ray tube Oxford TF3005 with W anode, operating at 25 kV and 100 {mu}A, and a Si-PIN XR-100CR detector from Amptek. In each sample were obtained several spectra, with an acquisition time of 300 s and a beam collimation of 1.5 and 2 mm. The spectra were analyzed using the software QXAS-AXIL from IAEA. The analysis of the golden carvings of the altars, in

  19. IDEOLOGICALLY CHALLENGING ENTERTAINMENT (ICE

    Directory of Open Access Journals (Sweden)

    Dana Lori Chalmers

    2015-09-01

    Full Text Available Ideologically Challenging Entertainment (ICE is entertainment that challenges ‘us vs. them’ ideologies associated with radicalization, violent conflict and terrorism. ICE presents multiple perspectives on a conflict through mainstream entertainment. This article introduces the theoretical underpinnings of ICE, the first ICE production and the audience responses to it. The first ICE production was Two Merchants: The Merchant of Venice adapted to challenge ideologies of the Arab-Israeli Conflict. A mixed-methods study of audience responses explored whether this production inspired audiences to shift their ideological views. Each performance included two versions of the adaptation: a Jewish dominated society with an Arab Muslim minority, contrasted with an Arab Muslim dominated society and a Jewish minority. A mixed-methods study of audience responses explored whether this production inspired audiences to shift their ideological views to become more tolerant of differences away from ideological radicalization. Of audience members who did not initially agree with the premise of the production, 40% reconsidered their ideological views, indicating increased tolerance, greater awareness of and desire to change their own prejudices. In addition, 86% of the audience expressed their intention to discuss the production with others, thereby encouraging critical engagement with, and broader dissemination of the message. These outcomes suggest that high quality entertainment – as defined by audience responses to it - can become a powerful tool in the struggle against radicalised ideologies.

  20. Data archaeology at ICES

    Science.gov (United States)

    Dooley, Harry D.

    1992-01-01

    This paper provides a brief overview of the function of the International Council for the Exploration of the Sea (ICES), both past and present, in particular in the context of its interest in compiling oceanographic data sets. Details are provided of the procedures it adopted to ensure adequate internationally collaborative marine investigations during the first part of the century, such as how it provided a forum for action by its member states, how it coordinated and published the results of scientific programs, and how it provided a foundation, through scientists employed in the ICES Office, for the establishment of the original oceanographic marine databases and associated products, and the scientific interpretation of the results. The growth and expansion of this area of ICES activity is then traced, taking into account the changing conditions for oceanographic data management resulting from the establishment of the National Data Centres, as well as the World Data Centres for Oceanography, which were created to meet the needs of the International Geophysical Year (IGY). Finally, there is a discussion of the way in which the very existence of ICES has proved to be a valuable source of old data, some of which have not yet been digitized, but which can be readily retrieved because they have been very carefully documented throughout the years. Lessons from this activity are noted, and suggestions are made on how the past experiences of ICES can be utilized to ensure the availability of marine data to present and future generations of scientists.

  1. The Sculptured Hills of the Taurus Highlands: Implications for the relative age of Serenitatis, basin chronologies and the cratering history of the Moon

    Science.gov (United States)

    Spudis, P.D.; Wilhelms, D.E.; Robinson, M.S.

    2011-01-01

    New images from the Lunar Reconnaissance Orbiter Camera show the distribution and geological relations of the Sculptured Hills, a geological unit widespread in the highlands between the Serenitatis and Crisium basins. The Sculptured Hills shows knobby, undulating, radially textured, and plains-like morphologies and in many places is indistinguishable from the similarly knobby Alpes Formation, a facies of ejecta from the Imbrium basin. The new LROC image data show that the Sculptured Hills in the Taurus highlands is Imbrium ejecta and not directly related to the formation of the Serenitatis basin. This occurrence and the geological relations of this unit suggests that the Apollo 17 impact melts may not be not samples of the Serenitatis basin-forming impact, leaving their provenance undetermined and origin unexplained. If the Apollo 17 melt rocks are Serenitatis impact melt, up to half of the basin and large crater population of the Moon was created within a 30 Ma interval around 3.8 Ga in a global impact "cataclysm." Either interpretation significantly changes our view of the impact process and history of the Earth-Moon system. Copyright 2011 by the American Geophysical Union.

  2. IceBridge PARIS L2 Ice Thickness V001

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains contains Greenland ice thickness measurements acquired using the Pathfinder Advanced Radar Ice Sounder (PARIS).The data were collected as part...

  3. EASE-Grid Sea Ice Age

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides weekly estimates of sea ice age for the Arctic Ocean from remotely sensed sea ice motion and sea ice extent. The ice age data are derived from...

  4. Thin ice and storms: Sea ice deformation from buoy arrays deployed during N-ICE2015

    OpenAIRE

    Itkin, Polona; Spreen, Gunnar; Cheng, Bin; Doble, Martin; Girard-Ardhuin, Fanny; Haapala, Jari; Hughes, Nick; Kaleschke, Lars; Nicolaus, Marcel; Wilkinson, Jeremy

    2017-01-01

    Arctic sea ice has displayed significant thinning as well as an increase in drift speed in recent years. Taken together this suggests an associated rise in sea ice deformation rate. A winter and spring expedition to the sea ice covered region north of Svalbard – the Norwegian young sea ICE 2015 expedition (N-ICE2015) - gave an opportunity to deploy extensive buoy arrays and to monitor the deformation of the first- and second-year ice now common in the majority of the Arctic Basin. During the ...

  5. Dry Ice Etches Terrain

    Science.gov (United States)

    2007-01-01

    [figure removed for brevity, see original site] Figure 1 Every year seasonal carbon dioxide ice, known to us as 'dry ice,' covers the poles of Mars. In the south polar region this ice is translucent, allowing sunlight to pass through and warm the surface below. The ice then sublimes (evaporates) from the bottom of the ice layer, and carves channels in the surface. The channels take on many forms. In the subimage shown here (figure 1) the gas from the dry ice has etched wide shallow channels. This region is relatively flat, which may be the reason these channels have a different morphology than the 'spiders' seen in more hummocky terrain. Observation Geometry Image PSP_003364_0945 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on 15-Apr-2007. The complete image is centered at -85.4 degrees latitude, 104.0 degrees East longitude. The range to the target site was 251.5 km (157.2 miles). At this distance the image scale is 25.2 cm/pixel (with 1 x 1 binning) so objects 75 cm across are resolved. The image shown here has been map-projected to 25 cm/pixel . The image was taken at a local Mars time of 06:57 PM and the scene is illuminated from the west with a solar incidence angle of 75 degrees, thus the sun was about 15 degrees above the horizon. At a solar longitude of 219.6 degrees, the season on Mars is Northern Autumn.

  6. Submesoscale Sea Ice-Ocean Interactions in Marginal Ice Zones

    Science.gov (United States)

    Manucharyan, Georgy E.; Thompson, Andrew F.

    2017-12-01

    Signatures of ocean eddies, fronts, and filaments are commonly observed within marginal ice zones (MIZs) from satellite images of sea ice concentration, and in situ observations via ice-tethered profilers or underice gliders. However, localized and intermittent sea ice heating and advection by ocean eddies are currently not accounted for in climate models and may contribute to their biases and errors in sea ice forecasts. Here, we explore mechanical sea ice interactions with underlying submesoscale ocean turbulence. We demonstrate that the release of potential energy stored in meltwater fronts can lead to energetic submesoscale motions along MIZs with spatial scales O(10 km) and Rossby numbers O(1). In low-wind conditions, cyclonic eddies and filaments efficiently trap the sea ice and advect it over warmer surface ocean waters where it can effectively melt. The horizontal eddy diffusivity of sea ice mass and heat across the MIZ can reach O(200 m2 s-1). Submesoscale ocean variability also induces large vertical velocities (order 10 m d-1) that can bring relatively warm subsurface waters into the mixed layer. The ocean-sea ice heat fluxes are localized over cyclonic eddies and filaments reaching about 100 W m-2. We speculate that these submesoscale-driven intermittent fluxes of heat and sea ice can contribute to the seasonal evolution of MIZs. With the continuing global warming and sea ice thickness reduction in the Arctic Ocean, submesoscale sea ice-ocean processes are expected to become increasingly prominent.

  7. Ice cores and palaeoclimate

    International Nuclear Information System (INIS)

    Krogh Andersen, K.; Ditlevsen, P.; Steffensen, J.P.

    2001-01-01

    Ice cores from Greenland give testimony of a highly variable climate during the last glacial period. Dramatic climate warmings of 15 to 25 deg. C for the annual average temperature in less than a human lifetime have been documented. Several questions arise: Why is the Holocene so stable? Is climatic instability only a property of glacial periods? What is the mechanism behind the sudden climate changes? Are the increased temperatures in the past century man-made? And what happens in the future? The ice core community tries to attack some of these problems. The NGRIP ice core currently being drilled is analysed in very high detail, allowing for a very precise dating of climate events. It will be possible to study some of the fast changes on a year by year basis and from this we expect to find clues to the sequence of events during rapid changes. New techniques are hoped to allow for detection of annual layers as far back as 100,000 years and thus a much improved time scale over past climate changes. It is also hoped to find ice from the Eemian period. If the Eemian layers confirm the GRIP sequence, the Eemian was actually climatically unstable just as the glacial period. This would mean that the stability of the Holocene is unique. It would also mean, that if human made global warming indeed occurs, we could jeopardize the Holocene stability and create an unstable 'Eemian situation' which ultimately could start an ice age. Currenlty mankind is changing the composition of the atmosphere. Ice cores document significant increases in greenhouse gases, and due to increased emissions of sulfuric and nitric acid from fossil fuel burning, combustion engines and agriculture, modern Greenland snow is 3 - 5 times more acidic than pre-industrial snow (Mayewski et al., 1986). However, the magnitude and abruptness of the temperature changes of the past century do not exceed the magnitude of natural variability. It is from the ice core perspective thus not possible to attribute the

  8. Vacancy Concentration in Ice

    DEFF Research Database (Denmark)

    Mogensen, O. E.; Eldrup, Morten Mostgaard

    1977-01-01

    Based on the diffusion constant for self-diffusion in ice, which is believed to take place by a vacancy mechanism, we estimate the relative vacancy concentration near the melting point to be at least ∼ 10−6, i.e. much higher than previous estimates of about 10−10.......Based on the diffusion constant for self-diffusion in ice, which is believed to take place by a vacancy mechanism, we estimate the relative vacancy concentration near the melting point to be at least ∼ 10−6, i.e. much higher than previous estimates of about 10−10....

  9. IOMASA SEA ICE DEVELOPMENTS

    DEFF Research Database (Denmark)

    Andersen, Søren; Tonboe, Rasmus; Heygster, Georg

    2005-01-01

    and determine the circumstances that may lead to anomalous sea ice concentration retrieval as well as to assess and possibly minimize the sensitivities of the retrieval system. Through an active partnership with the SAF on Ocean and Sea Ice, a prototype system will be implemented as an experimental product...... chain in order to shorten the loop from development to operational processing. The presentation will present the developments and examples of the new retrievals and finally give an outlook to the future perspectives of the system....

  10. Safety hazard of aircraft icing

    Science.gov (United States)

    Mclean, J. C., Jr.

    1979-01-01

    The problem of aircraft icing is reported as well as the type of aircraft affected, the pilots involved, and an identification of the areas where reduction in icing accidents are readily accomplished.

  11. ICE Online Detainee Locator System

    Data.gov (United States)

    Department of Homeland Security — The Online Detainee Locator datasets provide the location of a detainee who is currently in ICE custody, or who was release from ICE custody for any reason with the...

  12. Ice recrystallization inhibition in ice cream as affected by ice structuring proteins from winter wheat grass.

    Science.gov (United States)

    Regand, A; Goff, H D

    2006-01-01

    Ice recrystallization in quiescently frozen sucrose solutions that contained some of the ingredients commonly found in ice cream and in ice cream manufactured under commercial conditions, with or without ice structuring proteins (ISP) from cold-acclimated winter wheat grass extract (AWWE), was assessed by bright field microscopy. In sucrose solutions, critical differences in moisture content, viscosity, ionic strength, and other properties derived from the presence of other ingredients (skim milk powder, corn syrup solids, locust bean gum) caused a reduction in ice crystal growth. Significant ISP activity in retarding ice crystal growth was observed in all solutions (44% for the most complex mix) containing 0.13% total protein from AWWE. In heat-shocked ice cream, ice recrystallization rates were significantly reduced 40 and 46% with the addition of 0.0025 and 0.0037% total protein from AWWE. The ISP activity in ice cream was not hindered by its inclusion in mix prior to pasteurization. A synergistic effect between ISP and stabilizer was observed, as ISP activity was reduced in the absence of stabilizer in ice cream formulations. A remarkably smoother texture for ice creams containing ISP after heat-shock storage was evident by sensory evaluation. The efficiency of ISP from AWWE in controlling ice crystal growth in ice cream has been demonstrated.

  13. “TEMPORIBUS DOMINI IOHANNIS EPISCOPI...” – On the Beginnings of Pre-Romanesque Sculpture in Boka Kotorska

    Directory of Open Access Journals (Sweden)

    Meri Zornija

    2016-01-01

    Full Text Available This paper focuses on a series of pre-Romanesque fragments found in Kotor and several other localities in Boka Kotorska, which can be linked to an early phase in the formation of the pre-Romanesque style. Chronological orientation points provided by the triple mention of Bishop Ivan, who was present at the Second Council of Nicaea in 787, have served as a framework dating the fragments to the last quarter of the 8th and the early 9th century. They are considered to be work of a highly skilful stonemason workshop, for which the name Stonemason Workshop from the Time of Bishop Ivan of Kotor has been proposed. The reliefs have been compared to analogous sculptural decoration adorning the cathedrals of other cities in the Eastern Adriatic based on similar stylistic and iconographic features,as well as masterful stonemasonry in high-quality marble. These analogies indicate a common visual language used by the masters active in the broad belt stretching from Istria to Boka Kotorska, who brought to our coast the spirit of new, pre-Romanesque art at the turn of the 9th century.

  14. Reflection and transmission of obliquely incident light by chiral sculptured thin films fabricated using asymmetric serial-bideposition technique

    Science.gov (United States)

    McAtee, Patrick D.; Lakhtakia, Akhlesh

    2017-10-01

    Chiral sculptured thin films (STFs) were grown using the asymmetric serial-bideposition (ASBD) technique, whereby (i) two subdeposits of unequal heights are separated by a substrate rotation of 180 deg about the central normal axis, and (ii) consecutive subdeposit pairs are separated by a small substrate rotation δ on the order of a few degrees. Eight samples were prepared with subdeposit heights in ratios of 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 5:1, 7:1, and 9:1. A finely ambichiral STF was also grown. All nine samples were grown with the same vapor flux direction and to have 10 periods with the same thickness. The spectrums of all eight circular remittances of every sample were measured over a wide range of incidence angle θinc. Redshifting and narrowing of the circular Bragg regime was observed with increasing subdeposit-height ratio for all values of θinc, arriving at a limit with the 9:1 sample. The finely ambichiral sample has a circular Bragg regime similar to that of the 9:1 sample, but the latter exhibits much better discrimination between incident left circularly polarized light and right circularly polarized light than the former for θinc larger than about 20 deg.

  15. Data-Driven Analysis of Virtual 3D Exploration of a Large Sculpture Collection in Real-World Museum Exhibitions

    KAUST Repository

    Agus, Marco

    2018-01-29

    We analyze use of an interactive system for the exploration of highly detailed three-dimensional (3D) models of a collection of protostoric Mediterranean sculptures. In this system, when the object of interest is selected, its detailed 3D model and associated information are presented at high resolution on a large display controlled by a touch-enabled horizontal surface at a suitable distance. The user interface combines an object-Aware interactive camera controller with an interactive point-ofinterest selector and is implemented within a scalable implementation based on multiresolution structures shared between the rendering and user interaction subsystems. The system was installed in several temporary and permanent exhibitions and was extensively used by tens of thousands of visitors. We provide a data-driven analysis of usage experience based on logs gathered during a 27-month period at four exhibitions in archeological museums for a total of more than 75K exploration sessions. We focus on discerning the main visitor behaviors during 3D exploration by employing tools for deriving interest measures on surfaces and tools for clustering and knowledge discovery from high-dimensional data. The results highlight the main trends in visitor behavior during the interactive sessions. These results provide useful insights for the design of 3D exploration user interfaces in future digital installations.© 2017 ACM 1556-4673/2017/12-ART2 $15.00.

  16. Polar Stereographic Valid Ice Masks Derived from National Ice Center Monthly Sea Ice Climatologies, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — These valid ice masks provide a way to remove spurious ice caused by residual weather effects and land spillover in passive microwave data. They are derived from the...

  17. Analysis on ice resistance and ice response of ships sailing in brash ice

    Directory of Open Access Journals (Sweden)

    WANG Chao

    2018-02-01

    Full Text Available [Objectives] In order to explore the interaction between a hull and crushed ice, [Methods] a discrete element model is combined with Euler multiphase flow. The force of a hull under different speeds and different ice levels is calculated, and the motion response of ice during ship-ice interaction discussed. The reasons for ice resistance and movement change are explained intuitively. [Results] The ice resistance of the hull is obtained, mainly due to the friction and collision of the crushed ice and hull surface, which increases with the increase of the speed, but when the speed increases to a certain value, the crushing resistance no longer increases and even reduces the trend. [Conclusions] This provides a reference for the optimization of ship type for ice zones, as well as propeller design.

  18. IceCube SWIRP

    Science.gov (United States)

    Wu, Dongliang L.

    2017-01-01

    Clouds, ice clouds in particular, are a major source of uncertainty in climate models. Submm-wave sensors fill the sensitivity gap between MW and IR.Cloud microphysical properties (particle size and shape) account for large (200 and 40) measurement uncertainty.

  19. Ecology under lake ice

    NARCIS (Netherlands)

    Hampton, Stephanie E.; Galloway, Aaron W. E.; Powers, Stephen M.; Ozersky, Ted; Woo, Kara H.; Batt, Ryan D.; Labou, Stephanie G.; O'Reilly, Catherine M.; Sharma, Sapna; Lottig, Noah R.; Stanley, Emily H.; North, Rebecca L.; Stockwell, Jason D.; Adrian, Rita; Weyhenmeyer, Gesa A.; Arvola, Lauri; Baulch, Helen M.; Bertani, Isabella; Bowman, Larry L., Jr.; Carey, Cayelan C.; Catalan, Jordi; Colom-Montero, William; Domine, Leah M.; Felip, Marisol; Granados, Ignacio; Gries, Corinna; Grossart, Hans-Peter; Haberman, Juta; Haldna, Marina; Hayden, Brian; Higgins, Scott N.; Jolley, Jeff C.; Kahilainen, Kimmo K.; Kaup, Enn; Kehoe, Michael J.; MacIntyre, Sally; Mackay, Anson W.; Mariash, Heather L.; Mckay, Robert M.; Nixdorf, Brigitte; Noges, Peeter; Noges, Tiina; Palmer, Michelle; Pierson, Don C.; Post, David M.; Pruett, Matthew J.; Rautio, Milla; Read, Jordan S.; Roberts, Sarah L.; Ruecker, Jacqueline; Sadro, Steven; Silow, Eugene A.; Smith, Derek E.; Sterner, Robert W.; Swann, George E. A.; Timofeyev, Maxim A.; Toro, Manuel; Twiss, Michael R.; Vogt, Richard J.; Watson, Susan B.; Whiteford, Erika J.; Xenopoulos, Marguerite A.

    Winter conditions are rapidly changing in temperate ecosystems, particularly for those that experi-ence periods of snow and ice cover. Relatively little is known of winter ecology in these systems,due to a historical research focus on summer ‘growing seasons’. We executed the first global

  20. User's guide for ICE

    International Nuclear Information System (INIS)

    Fraley, S.K.

    1976-07-01

    ICE is a cross-section mixing code which will accept cross sections from an AMPX working library and produce mixed cross sections in the AMPX working library format, ANISN format, and the group-independent ANISN format. User input is in the free-form or fixed-form FIDO structure. The code is operable as a module in the AMPX system

  1. Melting ice, growing trade?

    Directory of Open Access Journals (Sweden)

    Sami Bensassi

    2016-05-01

    Full Text Available Abstract Large reductions in Arctic sea ice, most notably in summer, coupled with growing interest in Arctic shipping and resource exploitation have renewed interest in the economic potential of the Northern Sea Route (NSR. Two key constraints on the future viability of the NSR pertain to bathymetry and the future evolution of the sea ice cover. Climate model projections of future sea ice conditions throughout the rest of the century suggest that even under the most “aggressive” emission scenario, increases in international trade between Europe and Asia will be very low. The large inter-annual variability of weather and sea ice conditions in the route, the Russian toll imposed for transiting the NSR, together with high insurance costs and scarce loading/unloading opportunities, limit the use of the NSR. We show that even if these obstacles are removed, the duration of the opening of the NSR over the course of the century is not long enough to offer a consequent boost to international trade at the macroeconomic level.

  2. Ice shelf fracture parameterization in an ice sheet model

    Directory of Open Access Journals (Sweden)

    S. Sun

    2017-11-01

    Full Text Available Floating ice shelves exert a stabilizing force onto the inland ice sheet. However, this buttressing effect is diminished by the fracture process, which on large scales effectively softens the ice, accelerating its flow, increasing calving, and potentially leading to ice shelf breakup. We add a continuum damage model (CDM to the BISICLES ice sheet model, which is intended to model the localized opening of crevasses under stress, the transport of those crevasses through the ice sheet, and the coupling between crevasse depth and the ice flow field and to carry out idealized numerical experiments examining the broad impact on large-scale ice sheet and shelf dynamics. In each case we see a complex pattern of damage evolve over time, with an eventual loss of buttressing approximately equivalent to halving the thickness of the ice shelf. We find that it is possible to achieve a similar ice flow pattern using a simple rule of thumb: introducing an enhancement factor ∼ 10 everywhere in the model domain. However, spatially varying damage (or equivalently, enhancement factor fields set at the start of prognostic calculations to match velocity observations, as is widely done in ice sheet simulations, ought to evolve in time, or grounding line retreat can be slowed by an order of magnitude.

  3. Autonomous Ice Mass Balance Buoys for Seasonal Sea Ice

    Science.gov (United States)

    Whitlock, J. D.; Planck, C.; Perovich, D. K.; Parno, J. T.; Elder, B. C.; Richter-Menge, J.; Polashenski, C. M.

    2017-12-01

    The ice mass-balance represents the integration of all surface and ocean heat fluxes and attributing the impact of these forcing fluxes on the ice cover can be accomplished by increasing temporal and spatial measurements. Mass balance information can be used to understand the ongoing changes in the Arctic sea ice cover and to improve predictions of future ice conditions. Thinner seasonal ice in the Arctic necessitates the deployment of Autonomous Ice Mass Balance buoys (IMB's) capable of long-term, in situ data collection in both ice and open ocean. Seasonal IMB's (SIMB's) are free floating IMB's that allow data collection in thick ice, thin ice, during times of transition, and even open water. The newest generation of SIMB aims to increase the number of reliable IMB's in the Arctic by leveraging inexpensive commercial-grade instrumentation when combined with specially developed monitoring hardware. Monitoring tasks are handled by a custom, expandable data logger that provides low-cost flexibility for integrating a large range of instrumentation. The SIMB features ultrasonic sensors for direct measurement of both snow depth and ice thickness and a digital temperature chain (DTC) for temperature measurements every 2cm through both snow and ice. Air temperature and pressure, along with GPS data complete the Arctic picture. Additionally, the new SIMB is more compact to maximize deployment opportunities from multiple types of platforms.

  4. Ice particle collisions

    Science.gov (United States)

    Sampara, Naresh; Turnbull, Barbara; Hill, Richard; Swift, Michael

    2017-04-01

    Granular interactions of ice occur in a range of geophysical, astrophysical and industrial applications. For example, Saturn's Rings are composed of icy particles from micrometers to kilometres in size - inertial and yet too small to interact gravitationally. In clouds, ice crystals are smashed to pieces before they re-aggregate to for snow floccules in a process that is very much open to interpretation. In a granular flow of ice particles, the energy spent in collisions can lead to localized surface changes and wetting, which in turn can promote aggregation. To understand the induced wetting and its effects, we present two novel experimental methods which provide snippets of insight into the collisional behaviour of macroscopic ice particles. Experiment 1: Microgravity experiments provide minute details of the contact between the ice particles during the collision. A diamagnetic levitation technique, as alternative to the parabolic flight or falling tower experiments, was used to understand the collisional behaviour of individual macroscopic icy bodies. A refrigerated cylinder, that can control ambient conditions, was inserted into the bore of an 18 Tesla superconducting magnet and cooled to -10°C. Initial binary collisions were created, where one 4 mm ice particle was levitated in the magnet bore whilst another particle was dropped vertically from the top of the bore. The trajectories of both particles were captured by high speed video to provide the three-dimensional particle velocities and track the collision outcome. Introducing complexity, multiple particles were levitated in the bore and an azimuthal turbulent air flow introduced, allowing the particles to collide with other particles within a coherent fluid structure (mimicking Saturn's rings, or an eddy in a cloud). In these experiments, a sequence of collisions occur, each one different to the previous one due to the changes in surface characteristics created by the collisions themselves. Aggregation

  5. Icing Research Tunnel

    Science.gov (United States)

    Chennault, Jonathan

    2004-01-01

    The Icing Research Tunnel in Building 11 at the NASA Glenn Research Center is committed to researching the effects of in flight icing on aircraft and testing ways to stop the formation of hazardous icing conditions on planes. During this summer, I worked here with Richard DelRosa, the lead engineer for this area. address one of the major concerns of aviation: icing conditions. During the war, many planes crashed (especially supply planes going over the.Himalayas) because ice built up in their wings and clogged the engines. To this day, it remains the largest ice tunnel in the world, with a test section that measures 6 feet high, 9 feet long, and 20 feet wide. It can simulate airspeeds from 50 to 300 miles per hour at temperatures as low as -50 Fahrenheit. Using these capabilities, IRT can simulate actual conditions at high altitudes. The first thing I did was creating a cross reference in Microsoft Excel. It lists commands for the DPU units that control the pressure and temperature variations in the tunnel, as well as the type of command (keyboard, multiplier, divide, etc). The cross reference also contains the algorithm for every command, and which page it is listed in on the control sheet (visual Auto-CAD graphs, which I helped to make). I actually spent most of the time on the computer using Auto-CAD. I drew a diagram of the entire icing tunnel and then drew diagrams of its various parts. Between my mentor and me, we have drawings of every part of it, from the spray bars to the thermocouples, power cabinets, input-output connectors for power systems, and layouts of various other machines. I was also responsible for drawing schematics for the Escort system (which controls the spray bars), the power system, DPUs, and other electrical systems. In my spare time, I am attempting to build and program the "toddler". Toddler is a walking robot that I have to program in PBASIC language. When complete, it should be able to walk on level terrain while avoiding obstacles in

  6. Improved ice loss estimate of the northwestern Greenland ice sheet

    DEFF Research Database (Denmark)

    Kjeldsen, Kristian Kjellerup; Khan, Shfaqat Abbas; Wahr, J.

    2013-01-01

    We estimate ice volume change rates in the northwest Greenland drainage basin during 2003–2009 using Ice, Cloud and land Elevation Satellite (ICESat) laser altimeter data. Elevation changes are often reported to be largest near the frontal portion of outlet glaciers. To improve the volume change...... a significant acceleration in mass loss at elevations above 1200 m. Both the improved mass loss estimate along the ice sheet margin and the acceleration at higher elevations have implications for predictions of the elastic adjustment of the lithosphere caused by present-day ice mass changes. Our study shows...... change. Our results show that adding Airborne Topographic Mapper and Land, Vegetation and Ice Sensor data to the ICESat data increases the catchment-wide estimate of ice volume loss by 11%, mainly due to an improved volume loss estimate along the ice sheet margin. Furthermore, our results show...

  7. Ice Caps and Ice Belts: The Effects of Obliquity on Ice-Albedo Feedback

    Science.gov (United States)

    Rose, Brian E. J.; Cronin, Timothy W.; Bitz, Cecilia M.

    2017-09-01

    Planetary obliquity determines the meridional distribution of the annual mean insolation. For obliquity exceeding 55°, the weakest insolation occurs at the equator. Stable partial snow and ice cover on such a planet would be in the form of a belt about the equator rather than polar caps. An analytical model of planetary climate is used to investigate the stability of ice caps and ice belts over the widest possible range of parameters. The model is a non-dimensional diffusive Energy Balance Model, representing insolation, heat transport, and ice-albedo feedback on a spherical planet. A complete analytical solution for any obliquity is given and validated against numerical solutions of a seasonal model in the “deep-water” regime of weak seasonal ice line migration. Multiple equilibria and unstable transitions between climate states (ice-free, Snowball, or ice cap/belt) are found over wide swaths of parameter space, including a “Large Ice-Belt Instability” and “Small Ice-Belt Instability” at high obliquity. The Snowball catastrophe is avoided at weak radiative forcing in two different scenarios: weak albedo feedback and inefficient heat transport (favoring stable partial ice cover), or efficient transport at high obliquity (favoring ice-free conditions). From speculative assumptions about distributions of planetary parameters, three-fourths to four-fifths of all planets with stable partial ice cover should be in the form of Earth-like polar caps.

  8. The Influence of Platelet Ice and Snow on Antarctic Land-fast Sea Ice

    OpenAIRE

    Hoppmann, Mario; Nicolaus, Marcel

    2011-01-01

    Sea ice fastened to coasts, icebergs and ice shelves is of crucial importance for climate- and ecosystems. Near Antarctic ice shelves, this land-fast sea ice exhibits two unique characteristics that distinguish it from most other sea ice: 1) Ice platelets form and grow in super-cooled water, which originates from ice shelf cavities. The crystals accumulate beneath the solid sea-ice cover and are incorporated into the sea-ice fabric, contributing between 10 and 60% to the mas...

  9. Multiscale Models of Melting Arctic Sea Ice

    Science.gov (United States)

    2013-09-30

    2, 2013, entitled, ``Sense of Scale, Measure by Color: Art , Science, and Mathematics of Planet Earth,’’ featuring paintings and sculpture by Per...Lecture, co-hosted by the Department of Mathematics and the Bowdoin College Museum of Art , coinciding with a museum exhibition April 4, 2013 - June

  10. Analysis of sea ice dynamics

    Science.gov (United States)

    Zwally, J.

    1988-01-01

    The ongoing work has established the basis for using multiyear sea ice concentrations from SMMR passive microwave for studies of largescale advection and convergence/divergence of the Arctic sea ice pack. Comparisons were made with numerical model simulations and buoy data showing qualitative agreement on daily to interannual time scales. Analysis of the 7-year SMMR data set shows significant interannual variations in the total area of multiyear ice. The scientific objective is to investigate the dynamics, mass balance, and interannual variability of the Arctic sea ice pack. The research emphasizes the direct application of sea ice parameters derived from passive microwave data (SMMR and SSMI) and collaborative studies using a sea ice dynamics model. The possible causes of observed interannual variations in the multiyear ice area are being examined. The relative effects of variations in the large scale advection and convergence/divergence within the ice pack on a regional and seasonal basis are investigated. The effects of anomolous atmospheric forcings are being examined, including the long-lived effects of synoptic events and monthly variations in the mean geostrophic winds. Estimates to be made will include the amount of new ice production within the ice pack during winter and the amount of ice exported from the pack.

  11. Experimental provocation of 'ice-cream headache' by ice cubes and ice water.

    Science.gov (United States)

    Mages, Stephan; Hensel, Ole; Zierz, Antonia Maria; Kraya, Torsten; Zierz, Stephan

    2017-04-01

    Background There are various studies on experimentally provoked 'ice-cream headache' or 'headache attributed to ingestion or inhalation of a cold stimulus' (HICS) using different provocation protocols. The aim of this study was to compare two provocation protocols. Methods Ice cubes pressed to the palate and fast ingestion of ice water were used to provoke HICS and clinical features were compared. Results The ice-water stimulus provoked HICS significantly more often than the ice-cube stimulus (9/77 vs. 39/77). Ice-water-provoked HICS had a significantly shorter latency (median 15 s, range 4-97 s vs. median 68 s, range 27-96 s). There was no difference in pain localisation. Character after ice-cube stimulation was predominantly described as pressing and after ice-water stimulation as stabbing. A second HICS followed in 10/39 (26%) of the headaches provoked by ice water. Lacrimation occurred significantly more often in volunteers with than in those without HICS. Discussion HICS provoked by ice water was more frequent, had a shorter latency, different pain character and higher pain intensity than HICS provoked by ice cubes. The finding of two subsequent HICS attacks in the same volunteers supports the notion that two types of HICS exist. Lacrimation during HICS indicates involvement of the trigeminal-autonomic reflex.

  12. An ethical lesson learned from the equestrian sculpture, "The Torch Bearers," at the University of Madrid Dental School.

    Science.gov (United States)

    Christen, Arden G; Christen, Joan A

    2007-01-01

    As dental professionals, we continue to learn ethical lessons throughout our careers and beyond. We may experience them in our day-to-day involvements with peers and patients, or they may present themselves under more unusual circumstances. In October, 1974, at the University of Madrid Dental School, the senior author had a deeply impressionable experience minutes before he helped to present a course to Spanish dentists in operative dentistry. His co-presenter was Dr. Miles R. Markley of Denver, Colorado, a National Consultant in Restorative Dentistry for the U.S. Air Force. Their ethics teacher that day was Dr. Gerardo Zabalo, Dean of the dental school. His object lesson was delivered at the base of an equestrian, aluminum, larger-than-life sculpture, "The Torch Bearers" which faced the school. The sculptor shows an old, wrinkled man, lying prostrate, with only enough strength left to raise a lighted torch upward. Reaching down to receive the torch is a robust, energized young man, who is sitting upon a sturdy stallion. The lesson which Dean Zabalo taught that day was simple but profound. The lit torch of ethics, learning and values is essentially transmitted from generation to generation, as young students learn from their elders, accept the torch from their retiring leaders, keep the torch brightly lit as they mature in their profession, and, then in turn, hand it over to those young professionals who will replace them. This process will continue, age after age. Thus the torch of learning and thinking is passed on. In the world of education, human contact and the continued sanctity of the scientific written word must be paramount. Students must be taught how to read, learn and think. Computer technology used exclusively as a mode of teaching and learning can never become a viable substitute for our traditional interactive methods which emphasize human to human interaction.

  13. Mars, earth, and ice

    International Nuclear Information System (INIS)

    Cordell, B.M.

    1986-01-01

    Possible mechanisms to explain the global ice covering of Mars, and previous ice ages on the earth, are considered. Evidence for the Milankovitch effect is found in the close correspondence of earth's past climate with its orbital variations, as recorded principally in ocean sediments, and the role of CO 2 is discussed. Mars' range of obliquity, 10 times that of the earth, and orbital eccentricity, fluctuating over a range 2 1/2 times that of the earth, could produce an important climate-driving cycle. Mathematical models of the Martian surface and atmosphere based on Viking data suggest that escaped CO 2 could create a surface pressure of 1-3 bars. Other factors such as the effect of continental drift, the increased brightness of the sun, and planetary reversals of magnetic field polarity are discussed, and the questions of where Martian water and CO 2 have gone are considered

  14. Animals and ICE

    DEFF Research Database (Denmark)

    van Hemmen, J Leo; Christensen-Dalsgaard, Jakob; Carr, Catherine E

    2016-01-01

    experimental and mathematical foundation, it is known that there is a low-frequency regime where the internal time difference (iTD) as perceived by the animal may well be 2-5 times higher than the external ITD, the interaural time difference, and that there is a frequency plateau over which the fraction i......TD/ITD is constant. There is also a high-frequency regime where the internal level (amplitude) difference iLD as perceived by the animal is much higher than the interaural level difference ILD measured externally between the two ears. The fundamental tympanic frequency segregates the two regimes. The present special...... issue devoted to "internally coupled ears" provides an overview of many aspects of ICE, be they acoustic, anatomical, auditory, mathematical, or neurobiological. A focus is on the hotly debated topic of what aspects of ICE animals actually exploit neuronally to localize a sound source....

  15. Skating on slippery ice

    Directory of Open Access Journals (Sweden)

    J. M. J. van Leeuwen

    2017-12-01

    Full Text Available The friction of a stationary moving skate on smooth ice is investigated, in particular in relation to the formation of a thin layer of water between skate and ice. It is found that the combination of ploughing and sliding gives a friction force that is rather insensitive for parameters such as velocity and temperature. The weak dependence originates from the pressure adjustment inside the water layer. For instance, high velocities, which would give rise to high friction, also lead to large pressures, which, in turn, decrease the contact zone and so lower the friction. The theory is a combination and completion of two existing but conflicting theories on the formation of the water layer.

  16. Sports: Ice -Doping Time

    OpenAIRE

    Barys Tasman

    2013-01-01

    In 2013 the systematic degradation of Belarusian sports continued, which was most vivid in the mass and most popular kinds of sports – soccer, hockey, track and field athletics, and also in the traditional Olympic disciplines – cycling, boxing, weight-lifting. The national ice hockey team lost the qualification tournament and failed to get to the Olympic Games in Sochi. The football national team took the last place in the qualifying group tournament at the 2014 World Cup. At the World Forum ...

  17. Car engine breather icing

    OpenAIRE

    Horoufi, Aryan

    2012-01-01

    Icing in an engine breather system can block the engine breather pipe, cause excessive crankcase pressure and degrade the engine performance. In this project, a numerical study, experimental tests and CFD analysis are employed in order to understand condensation and the extent of freezing inside a vertical pipe, a horizontal pipe and a T-joint pipe which are exposed to an external convective cooling. The pipe internal flow is assumed to be a vapour/air mixture. This study has l...

  18. Helicopter Icing Review.

    Science.gov (United States)

    1980-09-01

    on the ground or could be injurious to per- sons on the ground. Ice on the rotor hub and fuselage may become critical in a flight transitioning from...0 uE -4- c -) U. c-j -- 0- CL) - lCA AC) O C-)) 41 4J 4- -C -I Q -. x 0 s- =U. A S (U C C -- () : -) -_ __ _r__ . -( ___ 4)a -)r ’ ) - 0 n - 1 3092

  19. Ice condenser experimental plan

    International Nuclear Information System (INIS)

    Kannberg, L.D.; Piepel, G.F.; Owczarski, P.C.; Liebetrau, A.M.

    1986-01-01

    An experimental plan is being developed to validate the computer code ICEDF. The code was developed to estimate the extent of aerosol retention in the ice compartments of pressurized water reactor ice condenser containment systems during severe accidents. The development of the experimental plan began with review of available information on the conditions under which the code will be applied. Computer-generated estimates of thermohydraulic and aerosol conditions entering the ice condenser were evaluated and along with other information, used to generate design criteria. The design criteria have been used for preliminary test assembly design and for generation of statistical test designs. Consideration of the phenomena to be evaluated in the testing program, as well as equipment and measurement limitations, have led to changes in the design criteria and to subsequent changes in the test assembly design and statistical test design. The overall strategy in developing the experimental plan includes iterative generation and evaluation of candidate test designs using computer codes for statistical test design and ICEDF for estimation of experimental results. Estimates of experimental variability made prior to actual testing will be verified by replicate testing at preselected design points

  20. Using ice melting and ice rolling technologies to remove ice from sub-transmission and transmission lines at Manitoba Hydro

    International Nuclear Information System (INIS)

    Farias, A. R.

    1999-01-01

    Development of an of an Ice Storm Management program by Manitoba Hydro to reduce ice storm damage to its 8 kV feeders to 115 kV transmission lines, is discussed. The program consists of the de-icing of overhead lines, either by ice melting, or ice rolling. Ice melting involves the placement of a three-phase short at a calculated point. The term ice rolling denotes a process of mechanically stripping the ice from conductors. The most recent major ice storm experienced by Manitoba Hydro was in the winter of 1997/1998. During the period from February 6 to February 17, 1998, a total of 83 'ice melt' procedures were performed to melt the ice from 2,628 km of overhead line (7,883 km of conductor), in addition to 'ice rolling'. This paper describes Manitoba Hydro's 25-years' experience with ice melting and it also describes the advantages and disadvantages of both ice melting and ice rolling. Although not a panacea to combat the effects of ice storms, ice melting was found to be the most effective way of removing ice from overhead transmission and sub-transmission lines. Ice rolling was also found to be effective. Other tools that have been found to be useful by various utilities in combating ice storm damage include improved structure and line design, system design that provide more redundancies and emergency sources, and standby generators at critical load points

  1. Prosthetically guided bone sculpturing for a maxillary complete-arch implant-supported monolithic zirconia fixed prosthesis based on a digital smile design: A clinical report.

    Science.gov (United States)

    Rojas-Vizcaya, Fernando

    2017-11-01

    A digital smile design was used to create an average smile and to develop a removable interim restoration for an edentulous patient with a high smile line and different bone levels in the maxilla. The interim restoration was used as a guide to perform bone sculpturing to create space for the biological width and to restore a monolithic zirconia implant-supported fixed restoration. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  2. Modelling ice-ocean interaction in ice shelf crevasses

    Science.gov (United States)

    Jordan, J. R.; Holland, P.; Piggott, M. D.; Jenkins, A.; Kimura, S.

    2013-12-01

    Ocean freezing within ice shelf basal crevasses could potentially act as a stabilising influence on ice shelves, however ice-ocean interaction and ocean dynamics within these crevasses are as yet poorly understood. To this end, an idealised two-dimensional model of an ice shelf basal crevasse has been developed using Fluidity-ICOM, a finite element ocean model using an unstructured mesh. A model of frazil ice formation and deposition has been incorporated into Fluidity-ICOM to better represent the freezing process. Model results show that freezing at the top of crevasses leads to the formation of an unstable overturning circulation due to the rejection of dense, salty water. The strength of this circulation, which is increased by the formation of frazil ice, is found to be the dominant factor influencing the total freezing rate. Frazil ice precipitation is found to be responsible for roughly one sixth of ice formation on the top of the basal crevasse, with direct freezing, enhanced by the complex dynamics of the overturning circulation, responsible for the rest. Increasing the frazil crystal radii used in the model has little impact on the amount of frazil ice deposition but does increase the amount of direct freezing. Significant melting and freezing was found to occur on the walls of the crevasse due to the strong overturning circulation. With previous modelling approaches it has not been possible to simulate this strong circulation, with water rising up one side of the crevasse and down the other.

  3. IceCube systematic errors investigation: Simulation of the ice

    Energy Technology Data Exchange (ETDEWEB)

    Resconi, Elisa; Wolf, Martin [Max-Planck-Institute for Nuclear Physics, Heidelberg (Germany); Schukraft, Anne [RWTH, Aachen University (Germany)

    2010-07-01

    IceCube is a neutrino observatory for astroparticle and astronomy research at the South Pole. It uses one cubic kilometer of Antartica's deepest ice (1500 m-2500 m in depth) to detect Cherenkov light, generated by charged particles traveling through the ice, with an array of phototubes encapsulated in glass pressure spheres. The arrival time as well as the charge deposited of the detected photons represent the base measurements that are used for track and energy reconstruction of those charged particles. The optical properties of the deep antarctic ice vary from layer to layer. Measurements of the ice properties and their correct modeling in Monte Carlo simulation is then of primary importance for the correct understanding of the IceCube telescope behavior. After a short summary about the different methods to investigate the ice properties and to calibrate the detector, we show how the simulation obtained by using this information compares to the measured data and how systematic errors due to uncertain ice properties are determined in IceCube.

  4. Ice blockage of water intakes

    International Nuclear Information System (INIS)

    Carey, K.L.

    1978-12-01

    The ice blockage of water intake structures can pose serious threats to the availability of cooling water at thermal power plants. Using information gained from a literature search and general knowledge of the problem, ice blockage difficulties are described as they may occur in rivers, lakes, reservoirs, and estuaries, and as they may affect intakes either at the surface or submerged. To further enable understanding of these problems, characteristics of both surface sheet ice and frazil ice are examined, namely, formational processes, sizes, thicknesses, movement or mobility, and modes of blockage or adhesion. Case histories of incidents of ice blockage of intakes are given by means of excerpts from the technical literature. Lastly, a brief overview is provided on the matter of solving ice blockage problems, either through original design, post-construction modification, or revised operational techniques

  5. Diffuse scattering in Ih ice

    International Nuclear Information System (INIS)

    Wehinger, Björn; Krisch, Michael; Bosak, Alexeï; Chernyshov, Dmitry; Bulat, Sergey; Ezhov, Victor

    2014-01-01

    Single crystals of ice Ih, extracted from the subglacial Lake Vostok accretion ice layer (3621 m depth) were investigated by means of diffuse x-ray scattering and inelastic x-ray scattering. The diffuse scattering was identified as mainly inelastic and rationalized in the frame of ab initio calculations for the ordered ice XI approximant. Together with Monte-Carlo modelling, our data allowed reconsidering previously available neutron diffuse scattering data of heavy ice as the sum of thermal diffuse scattering and static disorder contribution. (paper)

  6. Modelling the Early Weichselian Eurasian Ice Sheets: role of ice shelves and influence of ice-dammed lakes

    Directory of Open Access Journals (Sweden)

    V. Peyaud

    2007-07-01

    Full Text Available During the last glaciation, a marine ice sheet repeatedly appeared in Eurasia. The floating part of this ice sheet was essential to its rapid extension over the seas. During the earliest stage (90 kyr BP, large ice-dammed lakes formed south of the ice sheet. These lakes are believed to have cooled the climate at the margin of the ice. Using an ice sheet model, we investigated the role of ice shelves during the inception and the influence of ice-dammed lakes on the ice sheet evolution. Inception in Barents sea seems due to thickening of a large ice shelf. We observe a substantial impact of the lakes on the evolution of the ice sheets. Reduced summer ablation enhances ice extent and thickness, and the deglaciation is delayed by 2000 years.

  7. Ice storm `98

    Energy Technology Data Exchange (ETDEWEB)

    Soulard, F.; Trant, D.; Filoso, J.; Van Wesenbeeck, P. [Statistics Canada, Ottawa, ON (Canada). Environment Statistics Program

    1998-12-31

    As much as 100 millimeters of freezing rain fell on central and eastern Canada between January 4 to 10, 1998. This study concentrates on Canada`s St. Lawrence River Valley where total precipitation exceeded 73 mm in Kingston, 85 mm in Ottawa and 100 mm in areas south of Montreal. By comparison, the largest previously recorded ice storms left between 30 and 40 mm of ice. A state of emergency was declared for the affected regions. 56 per cent of Quebec`s population and 11 per cent of Ontario`s population were affected by the storm. Over 1000 power transmission towers collapsed and more than 30,000 wooden utility poles were brought down. In Quebec, nearly 1.4 million customers were left without electricity. In Ontario that number was about 230,000. While some manufacturers benefited directly from the storm, including makers of hydro and telephone poles, batteries and specialized electrical equipment, the overall economic losses for Montreal and Ottawa were high as estimates run to $585 million and $114 million, respectively. Almost 5 million sugar maple taps in Quebec and Ontario were located and suffered some damage in the affected areas. Nearly one-quarter (274,000) of all dairy cows were also located in the affected areas. Since in the absence of electricity they could not be milked, many of them suffered from mastitis. Many succumbed, others that survived may never attain their former level of productivity. As of June 1998, over 600,000 insurance claims totaling one billion dollars had been filed by Canadian households and businesses from the area affected by the ice storm.1 fig.

  8. Improved ice loss estimate of the northwestern Greenland ice sheet

    NARCIS (Netherlands)

    Kjeldsen, K.K.; Khan, S.A.; van den Broeke, M.R.; van Angelen, J.H.

    2013-01-01

    We estimate ice volume change rates in the northwest Greenland drainage basin during 2003–2009 using Ice, Cloud and land Elevation Satellite (ICESat) laser altimeter data. Elevation changes are often reported to be largest near the frontal portion of outlet glaciers. To improve the volume change

  9. Eulerian method for ice crystal icing in turbofan engines

    NARCIS (Netherlands)

    Norde, Ellen

    2017-01-01

    The newer generations of high-bypass-ratio engines are susceptible to the ingestion of small ice crystals which may cause engine power loss or damage. The research presented in this thesis focusses on the development of a computational method for in-engine ice crystal accretion. The work has been

  10. Ice Ages-Periodic Ice Coverings on the Earth

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 8. Ice Ages - Periodic Ice Coverings on the Earth. J Srinivasan. General Article Volume 4 Issue 8 August 1999 pp 25-35. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/004/08/0025-0035 ...

  11. Wave-Ice and Air-Ice-Ocean Interaction During the Chukchi Sea Ice Edge Advance

    Science.gov (United States)

    2015-09-30

    Chukchi Sea in the late summer have potentially changed the impact of fall storms by creating wave fields in the vicinity of the advancing ice edge. A...related to variability in storm and wave activity and changes in ice type and set the historical context for the Sea State field observations. Work...Doble Wave Climate and Wave Mixing in the Marginal Ice Zones of Arctic Seas: Observations and Modeling Babanin Storm Flux: Heat and Momentum

  12. recurrent ice ages

    Directory of Open Access Journals (Sweden)

    Andrei Korobeinikov

    2001-01-01

    Full Text Available Rapid and dramatic changes in climate and glacial conditions have taken place during the last 2.5 million years of the earth's history. Huge ice sheets expanded and contracted periodically, at times covering large areas of North America and Europe. Global sea levels dropped and rose 100 m to 150 m in response to the growth and melting of glaciers, causing continental coast lines to move far into present sea areas and then retreated again. We will use a simple conceptual model to demonstrate that these climate and glacier fluctuations can be a consequence of a supercritical Hopf bifurcation in models of the “ocean-land-atmosphere” system.

  13. Ice-driven CO2 feedback on ice volume

    Directory of Open Access Journals (Sweden)

    W. F. Ruddiman

    2006-01-01

    Full Text Available The origin of the major ice-sheet variations during the last 2.7 million years is a long-standing mystery. Neither the dominant 41 000-year cycles in δ18O/ice-volume during the late Pliocene and early Pleistocene nor the late-Pleistocene oscillations near 100 000 years is a linear ('Milankovitch' response to summer insolation forcing. Both responses must result from non-linear behavior within the climate system. Greenhouse gases (primarily CO2 are a plausible source of the required non-linearity, but confusion has persisted over whether the gases force ice volume or are a positive feedback. During the last several hundred thousand years, CO2 and ice volume (marine δ18O have varied in phase at the 41 000-year obliquity cycle and nearly in phase within the ~100 000-year band. This timing rules out greenhouse-gas forcing of a very slow ice response and instead favors ice control of a fast CO2 response. In the schematic model proposed here, ice sheets responded linearly to insolation forcing at the precession and obliquity cycles prior to 0.9 million years ago, but CO2 feedback amplified the ice response at the 41 000-year period by a factor of approximately two. After 0.9 million years ago, with slow polar cooling, ablation weakened. CO2 feedback continued to amplify ice-sheet growth every 41 000 years, but weaker ablation permitted some ice to survive insolation maxima of low intensity. Step-wise growth of these longer-lived ice sheets continued until peaks in northern summer insolation produced abrupt deglaciations every ~85 000 to ~115 000 years. Most of the deglacial ice melting resulted from the same CO2/temperature feedback that had built the ice sheets. Several processes have the northern geographic origin, as well as the requisite orbital tempo and phasing, to be candidate mechanisms for ice-sheet control of CO2 and their own feedback.

  14. The health of Antarctic ice shelves

    Science.gov (United States)

    Gagliardini, Olivier

    2018-01-01

    The thinning of floating ice shelves around Antarctica enhances upstream ice flow, contributing to sea-level rise. Ice-shelf thinning is now shown to influence glacial movement over much larger distances than previously thought.

  15. Great Lakes Ice Charts, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — These charts show ice extent and concentration three times weekly during the ice season, for all lakes except Ontario, from the 1973/74 ice season through the...

  16. Arctic Sea Ice Freeboard and Thickness

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides measurements of sea ice freeboard and sea ice thickness for the Arctic region. The data were derived from measurements made by from the Ice,...

  17. Elucidation of molecular and elementary composition of organic and inorganic substances involved in 19th century wax sculptures using an integrated analytical approach

    International Nuclear Information System (INIS)

    Regert, M.; Langlois, J.; Laval, E.; Le Ho, A.-S.; Pages-Camagna, S.

    2006-01-01

    Wax sculptures contain several materials from both organic and inorganic nature. These works of art are particularly fragile. Determining their chemical composition is thus of prime importance for their preservation. The identification of the recipes of waxy pastes used through time also provides valuable information in the field of art history. The aim of the present research was to develop a convenient analytical strategy, as non-invasive as possible, that allows to identify the wide range of materials involved in wax sculptures. A multi-step analytical methodology, based on the use of complementary techniques, either non- or micro-destructive, was elaborated. X-ray fluorescence and micro-Raman spectroscopy were used in a non-invasive way to identify inorganic pigments, opacifiers and extenders. The combination of structural and separative techniques, namely infrared spectroscopy, direct inlet electron ionisation mass spectrometry and high temperature gas chromatography, was shown to be appropriate for unravelling the precise composition of the organic substances. A micro-chemical test was also performed for the detection of starch. From this study it has been possible to elucidate the composition of the waxy pastes used by three different sculptors at the end of the 19th century. Complex and elaborated recipes, in which a large range of natural substances were combined, were highlighted

  18. Ion implantation in ices

    International Nuclear Information System (INIS)

    Strazzulla, G.; Baratta, G.A.; Palumbo, M.E.; Satorre, M.A.

    2000-01-01

    We have studied, by in situ infrared spectroscopy, some effects due to ion implantation in frozen ices. In particular mixtures containing C, N and O atoms (e.g., N 2 :H 2 O:CH 4 ) have been irradiated with unreactive (noble gases) ions: the resulting alteration of the frozen sample induces the formation of other molecules (e.g., CO 2 , R- - -OCN, CO and HCN) and of a refractory organic residue. Similar products are formed when mixtures containing only C and O atoms (e.g., H 2 O:CH 4 ) are irradiated with N ions, i.e. molecular species that include the projectile are formed. These results are important, in particular for their applications to planetary physics. In planetary environments ice thickness is usually much larger than the penetration depth of the relevant ion populations (solar wind ions, magnetospheric particles, etc.) and ion implantation phenomena are expected. Our results indicate that some molecular species observed on icy planetary surfaces could not be native of that object but formed by ion irradiation and/or by implantation of reactive ions

  19. Ice hockey injuries.

    Science.gov (United States)

    Benson, Brian W; Meeuwisse, Willem H

    2005-01-01

    This article reviews the distribution and determinants of injuries reported in the pediatric ice hockey literature, and suggests potential injury prevention strategies and directions for further research. Thirteen electronic databases, the ISI Web of Science, and 'grey literature' databases were searched using a combination of Medical Subject Headings and text words to identify potentially relevant articles. The bibliographies of selected studies were searched to identify additional articles. Studies were selected for review based on predetermined inclusion and exclusion criteria. A comparison between studies on this topic area was difficult due to the variability in research designs, definition of injury, study populations, and measurements used to assess injury. The majority of injuries were sustained during games compared with practices. The two most commonly reported injuries were sprains/strains and contusions. Players competing at the Minor hockey, High School, and Junior levels of competition sustained most of their injuries to the upper extremity, head, and lower extremity, respectively. The primary mechanism of injury was body checking, followed by stick and puck contact. The frequency of catastrophic eye injuries has been significantly reduced with the world-wide mandation of full facial protection for all Minor hockey players. Specific hockey-related injury risk factors are poorly delineated and rarely studied among pediatric ice hockey players leaving large gaps in the knowledge of appropriate prevention strategies. Risk management strategies should be focused at avoiding unnecessary foreseeable risk, and controlling the risks inherent to the sport. Suggestions for injury prevention and future research are discussed.

  20. Snow, ice and solar radiation

    NARCIS (Netherlands)

    Kuipers Munneke, P.

    2009-01-01

    The snow-covered ice sheets of Antarctica and Greenland reflect most of the incoming solar radiation. The reflectivity, commonly called the albedo, of snow on these ice sheets has been observed to vary in space and time. In this thesis, temporal and spatial changes in snow albedo is found to depend

  1. The physics of ice cream

    Science.gov (United States)

    Clarke, Chris

    2003-05-01

    Almost everybody likes ice cream, so it can provide an excellent vehicle for discussing and demonstrating a variety of physical phenomena, such as Newton's law of cooling, Boyle's law and the relationship between microstructure and macroscopic properties (e.g. Young's modulus). Furthermore, a demonstration of freezing point depression can be used to make ice cream in the classroom!

  2. Ice as a Construction Material

    Science.gov (United States)

    Zuppero, Anthony; Lewis, Joseph

    1998-01-01

    The use of ice as a construction material is discussed. A model of an ice tire torus space ship, which slowly spins to produce artificial gravity is proposed. The size of the ship, needed to support a given number of people and the required envelope mass is presented.

  3. Upper-Tropospheric Cloud Ice from IceCube

    Science.gov (United States)

    Wu, D. L.

    2017-12-01

    Cloud ice plays important roles in Earth's energy budget and cloud-precipitation processes. Knowledge of global cloud ice and its properties is critical for understanding and quantifying its roles in Earth's atmospheric system. It remains a great challenge to measure these variables accurately from space. Submillimeter (submm) wave remote sensing has capability of penetrating clouds and measuring ice mass and microphysical properties. In particular, the 883-GHz frequency is a highest spectral window in microwave frequencies that can be used to fill a sensitivity gap between thermal infrared (IR) and mm-wave sensors in current spaceborne cloud ice observations. IceCube is a cubesat spaceflight demonstration of 883-GHz radiometer technology. Its primary objective is to raise the technology readiness level (TRL) of 883-GHz cloud radiometer for future Earth science missions. By flying a commercial receiver on a 3U cubesat, IceCube is able to achieve fast-track maturation of space technology, by completing its development, integration and testing in 2.5 years. IceCube was successfully delivered to ISS in April 2017 and jettisoned from the International Space Station (ISS) in May 2017. The IceCube cloud-ice radiometer (ICIR) has been acquiring data since the jettison on a daytime-only operation. IceCube adopted a simple design without payload mechanism. It makes maximum utilization of solar power by spinning the spacecraft continuously about the Sun vector at a rate of 1.2° per second. As a result, the ICIR is operated under the limited resources (8.6 W without heater) and largely-varying (18°C-28°C) thermal environments. The spinning cubesat also allows ICIR to have periodical views between the Earth (atmosphere and clouds) and cold space (calibration), from which the first 883-GHz cloud map is obtained. The 883-GHz cloud radiance, sensitive to ice particle scattering, is proportional to cloud ice amount above 10 km. The ICIR cloud map acquired during June 20-July 2

  4. The IceProd Framework

    DEFF Research Database (Denmark)

    Aartsen, M.G.; Abbasi, R.; Ackermann, M.

    2015-01-01

    IceCube is a one-gigaton instrument located at the geographic South Pole, designed to detect cosmic neutrinos, iden- tify the particle nature of dark matter, and study high-energy neutrinos themselves. Simulation of the IceCube detector and processing of data require a significant amount...... of computational resources. IceProd is a distributed management system based on Python, XML-RPC and GridFTP. It is driven by a central database in order to coordinate and admin- ister production of simulations and processing of data produced by the IceCube detector. IceProd runs as a separate layer on top of other...... middleware and can take advantage of a variety of computing resources, including grids and batch systems such as CREAM, Condor, and PBS. This is accomplished by a set of dedicated daemons that process job submission in a coordinated fashion through the use of middleware plugins that serve to abstract...

  5. Ice storms and forest impacts.

    Science.gov (United States)

    Irland, L C

    2000-11-15

    Ice storms, or icing events, are important meteorological disturbances affecting forests over a surprisingly large portion of the USA. A broad belt extending from east Texas to New England experiences major ice storms at least once a decade; and truly major events occur in the heart of this belt once or twice a century. In the areas most affected, icing events are a factor that shapes stand composition, structure, and condition over wide areas. Impacts of individual storms are highly patchy and variable, and depend on the nature of the storm. Impacts also depend on how (or if) forest managers conduct subsequent salvage cuttings. Important research needs remain to be considered by the forest ecology and meteorology communities. At present, how ice storm frequency and severity may change with future climate change is unknown.

  6. Ice sheet hydrology from observations

    Energy Technology Data Exchange (ETDEWEB)

    Jansson, Peter (Dept. of Physical Geography and Quaternary Geology, Stockholm Univ-, Stockholm (Sweden))

    2010-11-15

    The hydrological systems of ice sheets are complex. Our view of the system is split, largely due to the complexity of observing the systems. Our basic knowledge of processes have been obtained from smaller glaciers and although applicable in general to the larger scales of the ice sheets, ice sheets contain features not observable on smaller glaciers due to their size. The generation of water on the ice sheet surface is well understood and can be satisfactorily modeled. The routing of water from the surface down through the ice is not complicated in terms of procat has been problematic is the way in which the couplings between surface and bed has been accomplished through a kilometer of cold ice, but with the studies on crack propagation and lake drainage on Greenland we are beginning to understand also this process and we know water can be routed through thick cold ice. Water generation at the bed is also well understood but the main problem preventing realistic estimates of water generation is lack of detailed information about geothermal heat fluxes and their geographical distribution beneath the ice. Although some average value for geothermal heat flux may suffice, for many purposes it is important that such values are not applied to sub-regions of significantly higher fluxes. Water generated by geothermal heat constitutes a constant supply and will likely maintain a steady system beneath the ice sheet. Such a system may include subglacial lakes as steady features and reconfiguration of the system is tied to time scales on which the ice sheet geometry changes so as to change pressure gradients in the basal system itself. Large scale re-organization of subglacial drainage systems have been observed beneath ice streams. The stability of an entirely subglacially fed drainage system may hence be perturbed by rapid ice flow. In the case of Antarctic ice streams where such behavior has been observed, the ice streams are underlain by deformable sediments. It is

  7. The IceProd (IceCube Production) Framework

    International Nuclear Information System (INIS)

    Díaz-Vélez, J C

    2014-01-01

    IceProd is a data processing and management framework developed by the IceCube Neutrino Observatory for processing of Monte Carlo simulations and data. IceProd runs as a separate layer on top of middleware or cluster job schedulers and can take advantage of a variety of computing resources including grids such as EGI, OSG, and NorduGrid as well as local clusters running batch systems like HT Condor, PBS, and SGE. This is accomplished by a set of dedicated daemons which process job submission in a coordinated fashion through the use of middleware plug-ins that serve to abstract the details of job submission and job management. IceProd can also manage complex workflow DAGs across distributed computing grids in order to optimize usage of resources. We describe several aspects of IceProd's design and it's applications in collaborative computing environments. We also briefly discuss design aspects of a second generation IceProd, currently being tested in IceCube.

  8. Recycled Paper Beam Sculpture

    Science.gov (United States)

    Keller, Kristin; Tabacchi, Jo

    2011-01-01

    As art department budgets across the country continue to shrink, art teachers are increasingly on the lookout for inexpensive materials that can be used to teach a range of concepts. In this article, the authors describe a newspaper beam tower project inspired by the book, "The Wonderful Towers of Watts" by Patricia Zelver. There are many more…

  9. Self-generated etchant for synthetic sculpturing of Cu 2O-Au, Cu 2O@Au, Au/Cu 2O, and 3D-Au nanostructures

    KAUST Repository

    Pang, Maolin

    2012-10-09

    Structures of Gold: A simple transformative method for nanoscale sculpturing has been developed. Five different types of complex nanocomposites of cuprite and gold have been formed by using this self-etching approach (see figure). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Arctic sea-ice ridges—Safe heavens for sea-ice fauna during periods of extreme ice melt?

    Science.gov (United States)

    Gradinger, Rolf; Bluhm, Bodil; Iken, Katrin

    2010-01-01

    The abundances and distribution of metazoan within-ice meiofauna (13 stations) and under-ice fauna (12 stations) were investigated in level sea ice and sea-ice ridges in the Chukchi/Beaufort Seas and Canada Basin in June/July 2005 using a combination of ice coring and SCUBA diving. Ice meiofauna abundance was estimated based on live counts in the bottom 30 cm of level sea ice based on triplicate ice core sampling at each location, and in individual ice chunks from ridges at four locations. Under-ice amphipods were counted in situ in replicate ( N=24-65 per station) 0.25 m 2 quadrats using SCUBA to a maximum water depth of 12 m. In level sea ice, the most abundant ice meiofauna groups were Turbellaria (46%), Nematoda (35%), and Harpacticoida (19%), with overall low abundances per station that ranged from 0.0 to 10.9 ind l -1 (median 0.8 ind l -1). In level ice, low ice algal pigment concentrations (Turbellaria, Nematoda and Harpacticoida also were observed in pressure ridges (0-200 ind l -1, median 40 ind l -1), although values were highly variable and only medians of Turbellaria were significantly higher in ridge ice than in level ice. Median abundances of under-ice amphipods at all ice types (level ice, various ice ridge structures) ranged from 8 to 114 ind m -2 per station and mainly consisted of Apherusa glacialis (87%), Onisimus spp. (7%) and Gammarus wilkitzkii (6%). Highest amphipod abundances were observed in pressure ridges at depths >3 m where abundances were up to 42-fold higher compared with level ice. We propose that the summer ice melt impacted meiofauna and under-ice amphipod abundance and distribution through (a) flushing, and (b) enhanced salinity stress at thinner level sea ice (less than 3 m thickness). We further suggest that pressure ridges, which extend into deeper, high-salinity water, become accumulation regions for ice meiofauna and under-ice amphipods in summer. Pressure ridges thus might be crucial for faunal survival during periods of

  11. Ice-clad volcanoes

    Science.gov (United States)

    Waitt, Richard B.; Edwards, B.R.; Fountain, Andrew G.; Huggel, C.; Carey, Mark; Clague, John J.; Kääb, Andreas

    2015-01-01

    An icy volcano even if called extinct or dormant may be active at depth. Magma creeps up, crystallizes, releases gas. After decades or millennia the pressure from magmatic gas exceeds the resistance of overlying rock and the volcano erupts. Repeated eruptions build a cone that pokes one or two kilometers or more above its surroundings - a point of cool climate supporting glaciers. Ice-clad volcanic peaks ring the northern Pacific and reach south to Chile, New Zealand, and Antarctica. Others punctuate Iceland and Africa (Fig 4.1). To climb is irresistible - if only “because it’s there” in George Mallory’s words. Among the intrepid ascents of icy volcanoes we count Alexander von Humboldt’s attempt on 6270-meter Chimborazo in 1802 and Edward Whymper’s success there 78 years later. By then Cotopaxi steamed to the north.

  12. INITIAL COOLING EXPERIMENT (ICE)

    CERN Multimedia

    CERN PhotoLab

    1979-01-01

    ICE was built in 1977, using the modified bending magnets of the g-2 muon storage ring (see 7405430). Its purpose was to verify the validity of stochastic and electron cooling for the antiproton project. Stochastic cooling proved a resounding success early in 1978 and the antiproton project could go ahead, now entirely based on stochastic cooling. Electron cooling was experimented with in 1979. The 26 kV equipment is housed in the cage to the left of the picture, adjacent to the "e-cooler" located in a straight section of the ring. With some modifications, the cooler was later transplanted into LEAR (Low Energy Antiproton Ring) and then, with further modifications, into the AD (Antiproton Decelerator), where it cools antiprotons to this day (2006). See also: 7711282, 7802099, 7809081.

  13. Ice-skating injuries.

    Science.gov (United States)

    Williamson, D M; Lowdon, I M

    1986-05-01

    The range of injuries sustained at an ice-rink and presented to an Accident Service department is described. A total of 203 patients with 222 injuries presented themselves during a 2-month period. There were 103 noteworthy injuries, including 61 fractures, 2 dislocations and 2 severed tendons, but the commonest injuries were wounds, sprains and bruises. Beginners appear to be more prone to injury than experienced skaters. In addition to using well-fitting skate-boots to protect the ankle, some injuries could be avoided by wearing elbow and knee pads, and a thick pair of gloves. The number of injuries compared with the total number of skaters was small but produced a noteworthy increase in the workload of the Accident Service.

  14. Initial Cooling Experiment (ICE)

    CERN Multimedia

    CERN PhotoLab

    1978-01-01

    ICE was built in 1977, in a record time of 9 months, using the modified bending magnets of the g-2 muon storage ring. Its purpose was to verify the validity of stochastic and electron cooling for the antiproton project, to be launched in 1978. Already early in 1978, stochastic cooling proved a resounding success, such that the antiproton (p-pbar)project was entirely based on it. Tests of electron cooling followed later: protons of 46 MeV kinetic energy were cooled with an electron beam of 26 kV and 1.3 A. The cage seen prominently in the foreground houses the HV equipment, adjacent to the "cooler" installed in a straight section of the ring. With some modifications, the cooler was later transplanted into LEAR (Low Energy Antiproton Ring) and then, with further modifications, into the AD (Antiproton Decelerator), where it cools antiprotons to this day (2006). See also: 7711282, 7802099, 7908242.

  15. City under the Ice

    DEFF Research Database (Denmark)

    Nielsen, Kristian Hvidtfelt

    conflict that gave impetus to the camp’s construction. Presented to the public as a scientific station and a technologically-advanced, under-ice extension of the American way of life, while situated in the titanic struggle between West and East, Camp Century took on a number of closed-world meanings...... military conflicts are taking place. Studying the wealth of public representations of Camp Century, established 1959-60 by the US Army 128 miles east of the Thule Air Base and often referred to as the “City under the Ice”, we find a sharp contrast between the domesticated interior and the superpower......: The public image of Camp Century was one of technological comfort and military-scientific control. Amidst the raging Cold War and up against the harsh environment, the construction of the camp would prove to the public that the combined forces of the US military-technology-science complex would prevail...

  16. IceCube deep core

    Energy Technology Data Exchange (ETDEWEB)

    Resconi, Elisa; Gross, Andreas; Schulz, Olaf; Sestayo, Yolanda [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Euler, Sebastian; Huelss, Jan-Patrick; Wiebusch, Christopher [RWTH Aachen, III Physikalisches Institut B, Aachen (Germany)

    2008-07-01

    The IceCube neutrino telescope has been designed to obtain the best performances in the energy region above few TeV. This will make IceCube sensitive to the co-called PeVatrons, i.e. sources of cosmic rays around the 'knee'. Recent observations of galactic sources from ground-based Cherenkov telescopes indicate a softening or cut-off at energies slightly lower than expected for the PeVatrons. Some of these sources could be also neutrino emitters, producing neutrinos at energies below the optimal range for IceCube. At even lower energies, the study of neutrino oscillations could become accessible as well as indirect dark matter search. Currently, a design study for the construction of a compact core inside IceCube called IceCube deep core is undergoing. IceCube deep core will significantly improve IceCube performances below 1 TeV and open the field of view to the southern hemisphere. We report in this talk the preliminary results of this design study including preliminary sensitivities.

  17. The fabrication and hydrophobic property of micro-nano patterned surface on magnesium alloy using combined sparking sculpture and etching route

    International Nuclear Information System (INIS)

    Wu, Yunfeng; Wang, Yaming; Liu, Hao; Liu, Yan; Guo, Lixin; Jia, Dechang; Ouyang, Jiahu; Zhou, Yu

    2016-01-01

    Highlights: • A hydrophobic micro-nano roughness surface on magnesium was fabricated. • Micro-nano structure derives from duplicating ‘over growth’ regions by MAO. • 7–9 μm micro-scale big pores insetting with nano-scale fine pores were fabricated. • Hydrophobicity of micro-nano surface was improved by chemical decoration and stearic treatment. - Abstract: Magnesium alloy with micro-nano structure roughness surface, can serve as the loading reservoirs of medicine capsule and industrial lubricating oil, or mimic ‘lotus leaf’ hydrophobic surface, having the potential applications in medical implants, automobile, aerospace and electronic products, etc. Herein, we propose a novel strategy to design a micro-nano structure roughness surface on magnesium alloy using combined microarc sparking sculpture and etching in CrO 3 aqueous solution. A hydrophobic surface (as an applied example) was further fabricated by chemical decorating on the obtained patterned magnesium alloy surface to enhance the corrosion resistance. The results show that the combined micro-nano structure of 7–9 μm diameter big pores insetting with nano-scale fine pores was duplicated after etched the sparking sculptured ‘over growth’ oxide regions towards the magnesium substrate. The micro-nano structure surface was chemically decorated using AgNO 3 and stearic acid, which enables the contact angle increased from 60° to 146.8°. The increasing contact angle is mainly attributed to the micro-nano structure and the chemical composition. The hydrophobic surface of magnesium alloy improved the corrosion potential from −1.521 V of the bare magnesium to −1.274 V. Generally, the sparking sculpture and then etching route demonstrates a low-cost, high-efficacy method to fabricate a micro-nano structure hydrophobic surface on magnesium alloy. Furthermore, our research on the creating of micro-nano structure roughness surface and the hydrophobic treatment can be easily extended to the

  18. The fabrication and hydrophobic property of micro-nano patterned surface on magnesium alloy using combined sparking sculpture and etching route

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yunfeng [Institute for Advanced Ceramics, Harbin Institute of Technology, Harbin 150001 (China); Wang, Yaming, E-mail: wangyaming@hit.edu.cn [Institute for Advanced Ceramics, Harbin Institute of Technology, Harbin 150001 (China); Liu, Hao [Institute for Advanced Ceramics, Harbin Institute of Technology, Harbin 150001 (China); Liu, Yan [Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022 (China); Guo, Lixin; Jia, Dechang; Ouyang, Jiahu; Zhou, Yu [Institute for Advanced Ceramics, Harbin Institute of Technology, Harbin 150001 (China)

    2016-12-15

    Highlights: • A hydrophobic micro-nano roughness surface on magnesium was fabricated. • Micro-nano structure derives from duplicating ‘over growth’ regions by MAO. • 7–9 μm micro-scale big pores insetting with nano-scale fine pores were fabricated. • Hydrophobicity of micro-nano surface was improved by chemical decoration and stearic treatment. - Abstract: Magnesium alloy with micro-nano structure roughness surface, can serve as the loading reservoirs of medicine capsule and industrial lubricating oil, or mimic ‘lotus leaf’ hydrophobic surface, having the potential applications in medical implants, automobile, aerospace and electronic products, etc. Herein, we propose a novel strategy to design a micro-nano structure roughness surface on magnesium alloy using combined microarc sparking sculpture and etching in CrO{sub 3} aqueous solution. A hydrophobic surface (as an applied example) was further fabricated by chemical decorating on the obtained patterned magnesium alloy surface to enhance the corrosion resistance. The results show that the combined micro-nano structure of 7–9 μm diameter big pores insetting with nano-scale fine pores was duplicated after etched the sparking sculptured ‘over growth’ oxide regions towards the magnesium substrate. The micro-nano structure surface was chemically decorated using AgNO{sub 3} and stearic acid, which enables the contact angle increased from 60° to 146.8°. The increasing contact angle is mainly attributed to the micro-nano structure and the chemical composition. The hydrophobic surface of magnesium alloy improved the corrosion potential from −1.521 V of the bare magnesium to −1.274 V. Generally, the sparking sculpture and then etching route demonstrates a low-cost, high-efficacy method to fabricate a micro-nano structure hydrophobic surface on magnesium alloy. Furthermore, our research on the creating of micro-nano structure roughness surface and the hydrophobic treatment can be easily

  19. VT Ice Damage Assessment from the 1998 Ice Storm

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) This dataset (ICEDAMAG98) depicts the extent and severity of tree damage caused by the 1998 ice storm, which resulted in extensive tree damage in...

  20. Nenana Ice Classic: Tanana River Ice Annual Breakup Dates

    Data.gov (United States)

    National Aeronautics and Space Administration — The Nenana river in the Interior of Alaska usually freezes over during October and November. The ice continues to grow throughout the winter accumulating an average...

  1. Modelling the Antarctic Ice Sheet

    DEFF Research Database (Denmark)

    Pedersen, Jens Olaf Pepke; Holm, A.

    2015-01-01

    Science) Antarctic Ice Sheet (DAIS) model (Shaffer 2014) is forced by reconstructed time series of Antarctic temperature, global sea level and ocean subsurface temperature over the last two glacial cycles. In this talk a modelling work of the Antarctic ice sheet over most of the Cenozoic era using...... the DAIS model will be presented. G. Shaffer (2014) Formulation, calibration and validation of the DAIS model (version 1), a simple Antarctic ice sheet model sensitive to variations of sea level and ocean subsurface temperature, Geosci. Model Dev., 7, 1803‐1818...

  2. Continuous Chemistry in Ice Cores

    DEFF Research Database (Denmark)

    Kjær, Helle Astrid

    corrections. Further the method successfully identified volcanic eruptions as well as the underlying anthropogenic signal related to the industrial pollution peaking in the 1970’s. The pH method was also applied on the Antarctic RICE ice core and proved useful, contrary to both the ECM and melt water...... into the ice due to scattering by individual snow grains at the very surface and by air bubbles in the upper part of the ice. However light is produced in situ by Cherenkov radiation from cosmic rays. As part of this thesis the penetration of light on surface layers of snow at NEEM was determined andthe 1/e...

  3. Influence of winter sea-ice motion on summer ice cover in the Arctic

    Directory of Open Access Journals (Sweden)

    Noriaki Kimura

    2013-11-01

    Full Text Available Summer sea-ice cover in the Arctic varies largely from year to year owing to several factors. This study examines one such factor, the relationship between interannual difference in winter ice motion and ice area in the following summer. A daily-ice velocity product on a 37.5-km resolution grid is prepared using the satellite passive microwave sensor Advanced Microwave Scanning Radiometer—Earth Observing System data for the nine years of 2003–2011. Derived daily-ice motion reveals the dynamic modification of the winter ice cover. The winter ice divergence/convergence is strongly related to the summer ice cover in some regions; the correlation coefficient between the winter ice convergence and summer ice area ranges between 0.5 and 0.9 in areas with high interannual variability. This relation implies that the winter ice redistribution controls the spring ice thickness and the summer ice cover.

  4. Ice911 Research: Preserving and Rebuilding Multi-Year Ice

    Science.gov (United States)

    Field, L. A.; Chetty, S.; Manzara, A.

    2013-12-01

    A localized surface albedo modification technique is being developed that shows promise as a method to increase multi-year ice using reflective floating materials, chosen so as to have low subsidiary environmental impact. Multi-year ice has diminished rapidly in the Arctic over the past 3 decades (Riihela et al, Nature Climate Change, August 4, 2013) and this plays a part in the continuing rapid decrease of summer-time ice. As summer-time ice disappears, the Arctic is losing its ability to act as the earth's refrigeration system, and this has widespread climatic effects, as well as a direct effect on sea level rise, as oceans heat, and once-land-based ice melts into the sea. We have tested the albedo modification technique on a small scale over five Winter/Spring seasons at sites including California's Sierra Nevada Mountains, a Canadian lake, and a small man-made lake in Minnesota, using various materials and an evolving array of instrumentation. The materials can float and can be made to minimize effects on marine habitat and species. The instrumentation is designed to be deployed in harsh and remote locations. Localized snow and ice preservation, and reductions in water heating, have been quantified in small-scale testing. Climate modeling is underway to analyze the effects of this method of surface albedo modification in key areas on the rate of oceanic and atmospheric temperature rise. We are also evaluating the effects of snow and ice preservation for protection of infrastructure and habitat stabilization. This paper will also discuss a possible reduction of sea level rise with an eye to quantification of cost/benefit. The most recent season's experimentation on a man-made private lake in Minnesota saw further evolution in the material and deployment approach. The materials were successfully deployed to shield underlying snow and ice from melting; applications of granular materials remained stable in the face of local wind and storms. Localized albedo

  5. Wave-Ice interaction in the Marginal Ice Zone: Toward a Wave-Ocean-Ice Coupled Modeling System

    Science.gov (United States)

    2015-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Wave-Ice interaction in the Marginal Ice Zone: Toward a...scattering of waves by interaction with ice in the Marginal Ice Zone (MIZ). The wave model physics developed here will later be part of an operational...10.5670/oceanog.2014.73. Liu, A.K., B. Holt, and P.W. Vachon, 1991: Wave propagation in the Marginal Ice Zone: Model predictions and comparisons

  6. Ice Accretion on Wind Turbine Blades

    DEFF Research Database (Denmark)

    Hudecz, Adriána; Koss, Holger; Hansen, Martin Otto Laver

    2013-01-01

    forces were monitored as ice was building up on the airfoil for glaze, rime and mixed ice. In the first part of the numerical analysis, the resulted ice profiles of the wind tunnel tests were compared to profiles estimated by using the 2D ice accretion code TURBICE. In the second part, Ansys Fluent...

  7. Amorphization of ice under mechanical stresses

    Science.gov (United States)

    Bordonskii, G. S.; Krylov, S. D.

    2017-11-01

    The dielectric parameters of freshly produced freshwater ice in the microwave range are investigated. It is established that this kind of ice contains a noticeable amount of amorphous ice. Its production is associated with plastic deformation under mechanical stresses. An assessment of the dielectric-permeability change caused by amorphous ice in the state of a slowly flowing medium is given.

  8. Rivers under ice: fluvial erosion beneath decaying ice sheets

    Science.gov (United States)

    Jansen, John D.; Codilean, Alexandru T.; Stroeven, Arjen P.; Fabel, Derek; Hättestrand, Clas; Kleman, Johan; Harbor, Jon M.; Heyman, Jakob; Kubik, Peter W.; Xu, Sheng

    2014-05-01

    The century-long debate over the origins of inner gorges cut within larger valleys that were repeatedly covered by Quaternary glaciers hinges upon whether the gorges are fluvial forms eroded by subaerial rivers, or subglacial forms cut beneath ice. We apply cosmogenic nuclide exposure dating to seven inner gorges along ~500 km of the former Fennoscandia ice sheet margin in combination with a new deglaciation isochron map. We show that the timing of bedrock exposure matches the advent of ice-free conditions, strongly suggesting that inner gorges were cut by channelised subglacial meltwater while simultaneously being shielded from cosmic rays by overlying ice. Given the exceptional hydraulic efficiency required for subglacial meltwater channels to erode bedrock and evacuate debris, we deduce that inner gorges are the product of ice sheets undergoing intense surface melting akin to that currently occurring on the Greenland ice sheet. The lack of postglacial river erosion in our seven inner gorges leads us to propose that channelised subglacial meltwater-boosted possibly by abrupt supraglacial lake drainage-may be a key driver of valley deepening on the Baltic Shield over multiple glacial cycles.

  9. Caracterização através de análise química da escultura portuguesa sobre madeira de produção erudita e de produção popular da época barroca Characterization by chemical analysis of portuguese baroque polychrome wooden sculptures with erudite and popular features

    Directory of Open Access Journals (Sweden)

    Carolina Barata

    2013-01-01

    Full Text Available Making use of several analytical techniques, four erudite and four popular Portuguese baroque wooden sculptures were studied. The materials and techniques employed were identified and the relationship between their artistic quality and the materials used was investigated. In general, the pigments were common at the time, but one pigment discovered in the beginning of the 18th century and two rare arsenic pigments were also identified. In popular sculptures cost-saving was detected, particularly concerning the gold leaf. Regarding some technical procedures identified, recommendations found in historical documents did not seem to have been entirely followed, neither in erudite nor in popular sculptures.

  10. Loss of sea ice in the Arctic.

    Science.gov (United States)

    Perovich, Donald K; Richter-Menge, Jacqueline A

    2009-01-01

    The Arctic sea ice cover is in decline. The areal extent of the ice cover has been decreasing for the past few decades at an accelerating rate. Evidence also points to a decrease in sea ice thickness and a reduction in the amount of thicker perennial sea ice. A general global warming trend has made the ice cover more vulnerable to natural fluctuations in atmospheric and oceanic forcing. The observed reduction in Arctic sea ice is a consequence of both thermodynamic and dynamic processes, including such factors as preconditioning of the ice cover, overall warming trends, changes in cloud coverage, shifts in atmospheric circulation patterns, increased export of older ice out of the Arctic, advection of ocean heat from the Pacific and North Atlantic, enhanced solar heating of the ocean, and the ice-albedo feedback. The diminishing Arctic sea ice is creating social, political, economic, and ecological challenges.

  11. Charge Transfer Scheme for Atmospheric Ice Sensing

    Directory of Open Access Journals (Sweden)

    Umair Najeeb MUGHAL

    2015-01-01

    Full Text Available The atmospheric icing parameters are being measured nowadays with the aid of more customized yet limited commercial equipment. The parameters include atmospheric ice detection, icing load and icing rate. The robustness of such equipment is usually under scrutiny when it comes to cold/harsh environment operations. This phenomenon was experienced consistently by the atmospheric Icing Research Team at Narvik University College during data retrieval exercises from its atmospheric icing stations installed at Fargnesfjellet during 2012-13. In this paper it is aimed to address the potential feasibility to produce a robust hardware addressing the icing measurements signals, which includes instrumentation hardware giving icing indications, icing type and de- icing rate measurements in a single platform (not commercially available till date.

  12. Holocene accumulation and ice flow near the West Antarctic Ice Sheet Divide ice core site

    Science.gov (United States)

    Koutnik, Michelle R.; Fudge, T. J.; Conway, Howard; Waddington, Edwin D.; Neumann, Thomas A.; Cuffey, Kurt M.; Buizert, Christo; Taylor, Kendrick C.

    2016-05-01

    The West Antarctic Ice Sheet Divide Core (WDC) provided a high-resolution climate record from near the Ross-Amundsen Divide in Central West Antarctica. In addition, radar-detected internal layers in the vicinity of the WDC site have been dated directly from the ice core to provide spatial variations in the age structure of the region. Using these two data sets together, we first infer a high-resolution Holocene accumulation-rate history from 9.2 kyr of the ice-core timescale and then confirm that this climate history is consistent with internal layers upstream of the core site. Even though the WDC was drilled only 24 km from the modern ice divide, advection of ice from upstream must be taken into account. We evaluate histories of accumulation rate by using a flowband model to generate internal layers that we compare to observed layers. Results show that the centennially averaged accumulation rate was over 20% lower than modern at 9.2 kyr before present (B.P.), increased by 40% from 9.2 to 2.3 kyr B.P., and decreased by at least 10% over the past 2 kyr B.P. to the modern values; these Holocene accumulation-rate changes in Central West Antarctica are larger than changes inferred from East Antarctic ice-core records. Despite significant changes in accumulation rate, throughout the Holocene the regional accumulation pattern has likely remained similar to today, and the ice-divide position has likely remained on average within 5 km of its modern position. Continent-scale ice-sheet models used for reconstructions of West Antarctic ice volume should incorporate this accumulation history.

  13. Sticking properties of ice grains

    Directory of Open Access Journals (Sweden)

    Jongmanns M.

    2017-01-01

    Full Text Available We study the size dependence of pull-off forces of water ice in laboratory experiments and numerical simulations. To determine the pull-off force in our laboratory experiments, we use a liquid nitrogen cooled centrifuge. Depending on its rotation frequency, spherical ice grains detach due to the centrifugal force which is related to the adhesive properties. Numerical simulations are conducted by means of molecular dynamics simulations of hexagonal ice using a standard coarse-grained water potential. The pull-off force of a single contact between two spherical ice grains is measured due to strain controlled simulations. Both, the experimental study and the simulations reveal a dependence between the pull-off force and the (reduced particle radii, which differ significantly from the linear dependence of common contact theories.

  14. Microfabricated Ice-Detection Sensor

    National Research Council Canada - National Science Library

    DeAnna, Russell

    1997-01-01

    .... The sensor is capable of distinguishing between an ice covered and a clean surface. It employs a bulk micromachined wafer with a 7 micrometers thick, boron doped, silicon diaphragm which serves as one plate of a parallel plate capacitor...

  15. Radiative properties of ice clouds

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, D.L.; Koracin, D.; Carter, E. [Desert Research Institute, Reno, NV (United States)

    1996-04-01

    A new treatment of cirrus cloud radiative properties has been developed, based on anomalous diffraction theory (ADT), which does not parameterize size distributions in terms of an effective radius. Rather, is uses the size distribution parameters directly, and explicitly considers the ice particle shapes. There are three fundamental features which characterize this treatment: (1) the ice path radiation experiences as it travels through an ice crystal is parameterized, (2) only determines the amount of radiation scattered and absorbed, and (3) as in other treatments, the projected area of the size distribution is conserved. The first two features are unique to this treatment, since it does not convert the ice particles into equivalent volume or area spheres in order to apply Mie theory.

  16. Sticking properties of ice grains

    Science.gov (United States)

    Jongmanns, M.; Kumm, M.; Wurm, G.; Wolf, D. E.; Teiser, J.

    2017-06-01

    We study the size dependence of pull-off forces of water ice in laboratory experiments and numerical simulations. To determine the pull-off force in our laboratory experiments, we use a liquid nitrogen cooled centrifuge. Depending on its rotation frequency, spherical ice grains detach due to the centrifugal force which is related to the adhesive properties. Numerical simulations are conducted by means of molecular dynamics simulations of hexagonal ice using a standard coarse-grained water potential. The pull-off force of a single contact between two spherical ice grains is measured due to strain controlled simulations. Both, the experimental study and the simulations reveal a dependence between the pull-off force and the (reduced) particle radii, which differ significantly from the linear dependence of common contact theories.

  17. 2006 Program of Study: Ice

    National Research Council Canada - National Science Library

    Balmforth, Neil J; Wettlaufer, John S; Worster, Grae

    2007-01-01

    .... Towards the end of Grae's lectures, we also held the 2006 GFD Public Lecture. This was given by Greg Dash of the University of Washington, on matters of ice physics and a well known popularization...

  18. Greenland Ice Sheet Mass Balance

    Science.gov (United States)

    Reeh, N.

    1984-01-01

    Mass balance equation for glaciers; areal distribution and ice volumes; estimates of actual mass balance; loss by calving of icebergs; hydrological budget for Greenland; and temporal variations of Greenland mass balance are examined.

  19. Images of Antarctic Ice Shelves

    Data.gov (United States)

    National Aeronautics and Space Administration — Recent changes in the extent and stability of ice shelves in the Antarctic Peninsula prompted NSIDC to begin a monitoring program using data from the AVHRR Polar 1...

  20. Let's Make Metric Ice Cream

    Science.gov (United States)

    Zimmerman, Marianna

    1975-01-01

    Describes a classroom activity which involved sixth grade students in a learning situation including making ice cream, safety procedures in a science laboratory, calibrating a thermometer, using metric units of volume and mass. (EB)

  1. Multiscale Models of Melting Arctic Sea Ice

    Science.gov (United States)

    2014-09-30

    Sea ice reflectance or albedo , a key parameter in climate modeling, is primarily determined by melt pond and ice floe configurations. Ice - albedo ...determine their albedo - a key parameter in climate modeling. Here we explore the possibility of a conceptual sea ice climate model passing through a...bifurcation points. Ising model for melt ponds on Arctic sea ice Y. Ma, I. Sudakov, and K. M. Golden Abstract: The albedo of melting

  2. Marginal Ice Zone: Biogeochemical Sampling with Gliders

    Science.gov (United States)

    2015-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Marginal Ice Zone: Biogeochemical Sampling with Gliders...under the ice and in the marginal ice zone. The project specific goals are to develop biogeochemical and optical proxies for glider optics; to use the...water, in the marginal ice zone, and under the ice; to use glider optical measurements to compute fields of rates of photosynthetic carbon fixation

  3. Ice sheet hydrology - a review

    International Nuclear Information System (INIS)

    Jansson, Peter; Naeslund, Jens-Ove; Rodhe, Lars

    2007-03-01

    This report summarizes the theoretical knowledge on water flow in and beneath glaciers and ice sheets and how these theories are applied in models to simulate the hydrology of ice sheets. The purpose is to present the state of knowledge and, perhaps more importantly, identify the gaps in our understanding of ice sheet hydrology. Many general concepts in hydrology and hydraulics are applicable to water flow in glaciers. However, the unique situation of having the liquid phase flowing in conduits of the solid phase of the same material, water, is not a commonly occurring phenomena. This situation means that the heat exchange between the phases and the resulting phase changes also have to be accounted for in the analysis. The fact that the solidus in the pressure-temperature dependent phase diagram of water has a negative slope provides further complications. Ice can thus melt or freeze from both temperature and pressure variations or variations in both. In order to provide details of the current understanding of water flow in conjunction with deforming ice and to provide understanding for the development of ideas and models, emphasis has been put on the mathematical treatments, which are reproduced in detail. Qualitative results corroborating theory or, perhaps more often, questioning the simplifications made in theory, are also given. The overarching problem with our knowledge of glacier hydrology is the gap between the local theories of processes and the general flow of water in glaciers and ice sheets. Water is often channelized in non-stationary conduits through the ice, features which due to their minute size relative to the size of glaciers and ice sheets are difficult to incorporate in spatially larger models. Since the dynamic response of ice sheets to global warming is becoming a key issue in, e.g. sea-level change studies, the problems of the coupling between the hydrology of an ice sheet and its dynamics is steadily gaining interest. New work is emerging

  4. Ice sheet hydrology - a review

    Energy Technology Data Exchange (ETDEWEB)

    Jansson, Peter; Naeslund, Jens-Ove [Dept. of Physical Geography and Quaternary Geology, Stockholm Univ., Stockholm (Sweden); Rodhe, Lars [Geological Survey of Sweden, Uppsala (Sweden)

    2007-03-15

    This report summarizes the theoretical knowledge on water flow in and beneath glaciers and ice sheets and how these theories are applied in models to simulate the hydrology of ice sheets. The purpose is to present the state of knowledge and, perhaps more importantly, identify the gaps in our understanding of ice sheet hydrology. Many general concepts in hydrology and hydraulics are applicable to water flow in glaciers. However, the unique situation of having the liquid phase flowing in conduits of the solid phase of the same material, water, is not a commonly occurring phenomena. This situation means that the heat exchange between the phases and the resulting phase changes also have to be accounted for in the analysis. The fact that the solidus in the pressure-temperature dependent phase diagram of water has a negative slope provides further complications. Ice can thus melt or freeze from both temperature and pressure variations or variations in both. In order to provide details of the current understanding of water flow in conjunction with deforming ice and to provide understanding for the development of ideas and models, emphasis has been put on the mathematical treatments, which are reproduced in detail. Qualitative results corroborating theory or, perhaps more often, questioning the simplifications made in theory, are also given. The overarching problem with our knowledge of glacier hydrology is the gap between the local theories of processes and the general flow of water in glaciers and ice sheets. Water is often channelized in non-stationary conduits through the ice, features which due to their minute size relative to the size of glaciers and ice sheets are difficult to incorporate in spatially larger models. Since the dynamic response of ice sheets to global warming is becoming a key issue in, e.g. sea-level change studies, the problems of the coupling between the hydrology of an ice sheet and its dynamics is steadily gaining interest. New work is emerging

  5. ICE CONTROL - Towards optimizing wind energy production during icing events

    Science.gov (United States)

    Dorninger, Manfred; Strauss, Lukas; Serafin, Stefano; Beck, Alexander; Wittmann, Christoph; Weidle, Florian; Meier, Florian; Bourgeois, Saskia; Cattin, René; Burchhart, Thomas; Fink, Martin

    2017-04-01

    Forecasts of wind power production loss caused by icing weather conditions are produced by a chain of physical models. The model chain consists of a numerical weather prediction model, an icing model and a production loss model. Each element of the model chain is affected by significant uncertainty, which can be quantified using targeted observations and a probabilistic forecasting approach. In this contribution, we present preliminary results from the recently launched project ICE CONTROL, an Austrian research initiative on measurements, probabilistic forecasting, and verification of icing on wind turbine blades. ICE CONTROL includes an experimental field phase, consisting of measurement campaigns in a wind park in Rhineland-Palatinate, Germany, in the winters 2016/17 and 2017/18. Instruments deployed during the campaigns consist of a conventional icing detector on the turbine hub and newly devised ice sensors (eologix Sensor System) on the turbine blades, as well as meteorological sensors for wind, temperature, humidity, visibility, and precipitation type and spectra. Liquid water content and spectral characteristics of super-cooled water droplets are measured using a Fog Monitor FM-120. Three cameras document the icing conditions on the instruments and on the blades. Different modelling approaches are used to quantify the components of the model-chain uncertainties. The uncertainty related to the initial conditions of the weather prediction is evaluated using the existing global ensemble prediction system (EPS) of the European Centre for Medium-Range Weather Forecasts (ECMWF). Furthermore, observation system experiments are conducted with the AROME model and its 3D-Var data assimilation to investigate the impact of additional observations (such as Mode-S aircraft data, SCADA data and MSG cloud mask initialization) on the numerical icing forecast. The uncertainty related to model formulation is estimated from multi-physics ensembles based on the Weather Research

  6. On the nature of the dirty ice at the bottom of the GISP2 ice core

    Science.gov (United States)

    Bender, Michael L.; Burgess, Edward; Alley, Richard B.; Barnett, Bruce; Clow, Gary D.

    2010-11-01

    We present data on the triple Ar isotope composition in trapped gas from clean, stratigraphically disturbed ice between 2800 and 3040 m depth in the GISP2 ice core, and from basal dirty ice from 3040 to 3053 m depth. We also present data for the abundance and isotopic composition of O 2 and N 2, and abundance of Ar, in the basal dirty ice. The Ar/N 2 ratio of dirty basal ice, the heavy isotope enrichment (reflecting gravitational fractionation), and the total gas content all indicate that the gases in basal dirty ice originate from the assimilation of clean ice of the overlying glacier, which comprises most of the ice in the dirty bottom layer. O 2 is partly to completely depleted in basal ice, reflecting active metabolism. The gravitationally corrected ratio of 40Ar/ 38Ar, which decreases with age in the global atmosphere, is compatible with an age of 100-250 ka for clean disturbed ice. In basal ice, 40Ar is present in excess due to injection of radiogenic 40Ar produced in the underlying continental crust. The weak depth gradient of 40Ar in the dirty basal ice, and the distribution of dirt, indicate mixing within the basal ice, while various published lines of evidence indicate mixing within the overlying clean, disturbed ice. Excess CH 4, which reaches thousands of ppm in basal dirty ice at GRIP, is virtually absent in overlying clean disturbed ice, demonstrating that mixing of dirty basal ice into the overlying clean ice, if it occurs at all, is very slow. Order-of-magnitude estimates indicate that the mixing rate of clean ice into dirty ice is sufficient to maintain a steady thickness of dirty ice against thinning from the mean ice flow. The dirty ice appears to consist of two or more basal components in addition to clean glacial ice. A small amount of soil or permafrost, plus preglacial snow, lake or ground ice could explain the observations.

  7. On the nature of the dirty ice at the bottom of the GISP2 ice core

    Science.gov (United States)

    Bender, Michael L.; Burgess, Edward; Alley, Richard B.; Barnett, Bruce; Clow, Gary D.

    2010-01-01

    We present data on the triple Ar isotope composition in trapped gas from clean, stratigraphically disturbed ice between 2800 and 3040m depth in the GISP2 ice core, and from basal dirty ice from 3040 to 3053m depth. We also present data for the abundance and isotopic composition of O2 and N2, and abundance of Ar, in the basal dirty ice. The Ar/N2 ratio of dirty basal ice, the heavy isotope enrichment (reflecting gravitational fractionation), and the total gas content all indicate that the gases in basal dirty ice originate from the assimilation of clean ice of the overlying glacier, which comprises most of the ice in the dirty bottom layer. O2 is partly to completely depleted in basal ice, reflecting active metabolism. The gravitationally corrected ratio of 40Ar/38Ar, which decreases with age in the global atmosphere, is compatible with an age of 100-250ka for clean disturbed ice. In basal ice, 40Ar is present in excess due to injection of radiogenic 40Ar produced in the underlying continental crust. The weak depth gradient of 40Ar in the dirty basal ice, and the distribution of dirt, indicate mixing within the basal ice, while various published lines of evidence indicate mixing within the overlying clean, disturbed ice. Excess CH4, which reaches thousands of ppm in basal dirty ice at GRIP, is virtually absent in overlying clean disturbed ice, demonstrating that mixing of dirty basal ice into the overlying clean ice, if it occurs at all, is very slow. Order-of-magnitude estimates indicate that the mixing rate of clean ice into dirty ice is sufficient to maintain a steady thickness of dirty ice against thinning from the mean ice flow. The dirty ice appears to consist of two or more basal components in addition to clean glacial ice. A small amount of soil or permafrost, plus preglacial snow, lake or ground ice could explain the observations.

  8. How Cubic Can Ice Be?

    Science.gov (United States)

    Amaya, Andrew J; Pathak, Harshad; Modak, Viraj P; Laksmono, Hartawan; Loh, N Duane; Sellberg, Jonas A; Sierra, Raymond G; McQueen, Trevor A; Hayes, Matt J; Williams, Garth J; Messerschmidt, Marc; Boutet, Sébastien; Bogan, Michael J; Nilsson, Anders; Stan, Claudiu A; Wyslouzil, Barbara E

    2017-07-20

    Using an X-ray laser, we investigated the crystal structure of ice formed by homogeneous ice nucleation in deeply supercooled water nanodrops (r ≈ 10 nm) at ∼225 K. The nanodrops were formed by condensation of vapor in a supersonic nozzle, and the ice was probed within 100 μs of freezing using femtosecond wide-angle X-ray scattering at the Linac Coherent Light Source free-electron X-ray laser. The X-ray diffraction spectra indicate that this ice has a metastable, predominantly cubic structure; the shape of the first ice diffraction peak suggests stacking-disordered ice with a cubicity value, χ, in the range of 0.78 ± 0.05. The cubicity value determined here is higher than those determined in experiments with micron-sized drops but comparable to those found in molecular dynamics simulations. The high cubicity is most likely caused by the extremely low freezing temperatures and by the rapid freezing, which occurs on a ∼1 μs time scale in single nanodroplets.

  9. STABLE ISOTOPE GEOCHEMISTRY OF MASSIVE ICE

    Directory of Open Access Journals (Sweden)

    Yurij K. Vasil’chuk

    2016-01-01

    Full Text Available The paper summarises stable-isotope research on massive ice in the Russian and North American Arctic, and includes the latest understanding of massive-ice formation. A new classification of massive-ice complexes is proposed, encompassing the range and variabilityof massive ice. It distinguishes two new categories of massive-ice complexes: homogeneousmassive-ice complexes have a similar structure, properties and genesis throughout, whereasheterogeneous massive-ice complexes vary spatially (in their structure and properties andgenetically within a locality and consist of two or more homogeneous massive-ice bodies.Analysis of pollen and spores in massive ice from Subarctic regions and from ice and snow cover of Arctic ice caps assists with interpretation of the origin of massive ice. Radiocarbon ages of massive ice and host sediments are considered together with isotope values of heavy oxygen and deuterium from massive ice plotted at a uniform scale in order to assist interpretation and correlation of the ice.

  10. Momentum Exchange Near Ice Keels in the Under Ice Ocean Boundary Layer

    National Research Council Canada - National Science Library

    Bleidorn, John C

    2008-01-01

    .... Understanding ice-ocean momentum exchange is important for accurate predictive ice modeling. Due to climate change, increased naval presence in the Arctic region is anticipated and ice models will become necessary for tactical and safety reasons...

  11. The IceCube Neutrino Observatory VI: Neutrino Oscillations, Supernova Searches, Ice Properties

    OpenAIRE

    The IceCube Collaboration

    2011-01-01

    Atmospheric neutrino oscillations with DeepCore; Supernova detection with IceCube and beyond; Study of South Pole ice transparency with IceCube flashers; Submitted papers to the 32nd International Cosmic Ray Conference, Beijing 2011.

  12. Canadian Ice Service Arctic Regional Sea Ice Charts in SIGRID-3 Format

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Canadian Ice Service (CIS) produces digital Arctic regional sea ice charts for marine navigation, climate research, and input to the Global Digital Sea Ice Data...

  13. Canadian Ice Service Arctic Regional Sea Ice Charts in SIGRID-3 Format, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — The Canadian Ice Service (CIS) produces digital Arctic regional sea ice charts for marine navigation, climate research, and input to the Global Digital Sea Ice Data...

  14. Videos of Basal Ice in Boreholes on the Kamb Ice Stream in West Antarctica, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set is a collection of video data of basal ice taken in a borehole on the Kamb Ice Stream in West Antarctica. Ice streams are an expression of the inherent...

  15. IceBridge HiCARS 1 L2 Geolocated Ice Thickness

    Data.gov (United States)

    National Aeronautics and Space Administration — The NASA IceBridge HiCARS 1 Level-2 Geolocated Ice Thickness (IR1HI2) data set contains Ice Thickness, Surface Elevations, and Bed Elevation measurements taken over...

  16. IceAge: Chemical Evolution of Ices during Star Formation

    Science.gov (United States)

    McClure, Melissa; Bailey, J.; Beck, T.; Boogert, A.; Brown, W.; Caselli, P.; Chiar, J.; Egami, E.; Fraser, H.; Garrod, R.; Gordon, K.; Ioppolo, S.; Jimenez-Serra, I.; Jorgensen, J.; Kristensen, L.; Linnartz, H.; McCoustra, M.; Murillo, N.; Noble, J.; Oberg, K.; Palumbo, M.; Pendleton, Y.; Pontoppidan, K.; Van Dishoeck, E.; Viti, S.

    2017-11-01

    Icy grain mantles are the main reservoir for volatile elements in star-forming regions across the Universe, as well as the formation site of pre-biotic complex organic molecules (COMs) seen in our Solar System. We propose to trace the evolution of pristine and complex ice chemistry in a representative low-mass star-forming region through observations of a: pre-stellar core, Class 0 protostar, Class I protostar, and protoplanetary disk. Comparing high spectral resolution (R 1500-3000) and sensitivity (S/N 100-300) observations from 3 to 15 um to template spectra, we will map the spatial distribution of ices down to 20-50 AU in these targets to identify when, and at what visual extinction, the formation of each ice species begins. Such high-resolution spectra will allow us to search for new COMs, as well as distinguish between different ice morphologies,thermal histories, and mixing environments. The analysis of these data will result in science products beneficial to Cycle 2 proposers. A newly updated public laboratory ice database will provide feature identifications for all of the expected ices, while a chemical model fit to the observed ice abundances will be released publically as a grid, with varied metallicity and UV fields to simulate other environments. We will create improved algorithms to extract NIRCAM WFSS spectra in crowded fields with extended sources as well as optimize the defringing of MIRI LRS spectra in order to recover broad spectral features. We anticipate that these resources will be particularly useful for astrochemistry and spectroscopy of fainter, extended targets like star forming regions of the SMC/LMC or more distant galaxies.

  17. Acquisition of Ice Thickness and Ice Surface Characteristics in the Seasonal Ice Zone by CULPIS-X during the US Coast Guard’s Arctic Domain Awareness Program

    Science.gov (United States)

    2014-09-30

    OBJECTIVES • What is the volume of sea ice in the Beaufort Sea Seasonal Ice Zone (SIZ) and how does this evolve during summer as the ice edge...retreats? Recent observations suggest that the remaining ice in the Beaufort Sea is younger and thinner in recent years in part because even the oldest...surrounding ice . Recent analyses have indicated that ponds on thinner ice are often darker, accelerating the ice - albedo feedback over thin ice in summer

  18. On Wave-Ice Interaction in the Arctic Marginal Ice Zone: Dispersion, Attenuation, and Ice Response

    Science.gov (United States)

    2016-06-01

    36 FIGURE 9 THE SPECTRAL ATTENUATION RATES AS A FUNCTION OF WAVE PERIOD. THE LIGHT COLORED LINES ARE THE INDIVIDUAL...ice surfaces, which is currently being investigated as a new mechanism contributing to ice melting and reduced wave transmission [Skene et al., 2015...is a transmission coefficient and the critical strain is assumed, = 3 × 10−5. Given the length of time step and the zero-crossing wave

  19. Dynamics of Under Ice Boundary Layers Below Floating Ice Shelves

    Science.gov (United States)

    Shaw, W. J.; Stanton, T. P.

    2016-02-01

    Pine Island Glacier (PIG), a major outlet stream of the Western Antarctic Ice Sheet, has dramatically thinned and accelerated in recent decades. It is believed that a weakening of the floating portion of the glacier, known as the ice shelf, due to increased ocean thermal forcing is a primary cause of the observed increasing discharge of PIG. In order to better understand the controls on the exchange of heat between the PIG shelf and the underlying ocean cavity, a numerical model, MITgcm, has been configured to study the dynamics of the sloping, meltwater-forced, buoyant boundary layer below the ice shelf A 2-D approximation allows for high vertical resolution that resolves well the under shelf ocean boundary layer. We are particularly interested in the dynamical balance between buoyancy along the sloping ice shelf base, drag, and entrainment/detrainment and the associated feedback of basal melting of the ice shelf. Numerical results will be compared to in-situ observations obtained through a field campaign in 2013.

  20. Response timescales for martian ice masses and implications for ice flow on Mars

    DEFF Research Database (Denmark)

    Koutnik, Michelle Rebecca; Waddington, E.D.; Winebrener, D.P.

    2013-01-01

    ice-flow rates were more significant than today. A plausible range of near-basal ice temperatures and ice-flow enhancement factors can generate the characteristic geometry of an ice mass that has been shaped by flow over reasonable volume-response timescales. All plausible ice-flow scenarios require......On Earth and on Mars, ice masses experience changes in precipitation, temperature, and radiation. In a new climate state, flowing ice masses will adjust in length and in thickness, and this response toward a new steady state has a characteristic timescale. However, a flowing ice mass has...

  1. Airborne Tomographic Swath Ice Sounding Processing System

    Science.gov (United States)

    Wu, Xiaoqing; Rodriquez, Ernesto; Freeman, Anthony; Jezek, Ken

    2013-01-01

    Glaciers and ice sheets modulate global sea level by storing water deposited as snow on the surface, and discharging water back into the ocean through melting. Their physical state can be characterized in terms of their mass balance and dynamics. To estimate the current ice mass balance, and to predict future changes in the motion of the Greenland and Antarctic ice sheets, it is necessary to know the ice sheet thickness and the physical conditions of the ice sheet surface and bed. This information is required at fine resolution and over extensive portions of the ice sheets. A tomographic algorithm has been developed to take raw data collected by a multiple-channel synthetic aperture sounding radar system over a polar ice sheet and convert those data into two-dimensional (2D) ice thickness measurements. Prior to this work, conventional processing techniques only provided one-dimensional ice thickness measurements along profiles.

  2. What Determines the Ice Polymorph in Clouds?

    Science.gov (United States)

    Hudait, Arpa; Molinero, Valeria

    2016-07-20

    Ice crystals in the atmosphere nucleate from supercooled liquid water and grow by vapor uptake. The structure of the ice polymorph grown has strong impact on the morphology and light scattering of the ice crystals, modulates the amount of water vapor in ice clouds, and can impact the molecular uptake and reactivity of atmospheric aerosols. Experiments and molecular simulations indicate that ice nucleated and grown from deeply supercooled liquid water is metastable stacking disordered ice. The ice polymorph grown from vapor has not yet been determined. Here we use large-scale molecular simulations to determine the structure of ice that grows as a result of uptake of water vapor in the temperature range relevant to cirrus and mixed-phase clouds, elucidate the molecular mechanism of the formation of ice at the vapor interface, and compute the free energy difference between cubic and hexagonal ice interfaces with vapor. We find that vapor deposition results in growth of stacking disordered ice only under conditions of extreme supersaturation, for which a nonequilibrium liquid layer completely wets the surface of ice. Such extreme conditions have been used to produce stacking disordered frost ice in experiments and may be plausible in the summer polar mesosphere. Growth of ice from vapor at moderate supersaturations in the temperature range relevant to cirrus and mixed-phase clouds, from 200 to 260 K, produces exclusively the stable hexagonal ice polymorph. Cubic ice is disfavored with respect to hexagonal ice not only by a small penalty in the bulk free energy (3.6 ± 1.5 J mol(-1) at 260 K) but also by a large free energy penalty at the ice-vapor interface (89.7 ± 12.8 J mol(-1) at 260 K). The latter originates in higher vibrational entropy of the hexagonal-terminated ice-vapor interface. We predict that the free energy penalty against the cubic ice interface should decrease strongly with temperature, resulting in some degree of stacking disorder in ice grown from

  3. Mixed ice accretion on aircraft wings

    Science.gov (United States)

    Janjua, Zaid A.; Turnbull, Barbara; Hibberd, Stephen; Choi, Kwing-So

    2018-02-01

    Ice accretion is a problematic natural phenomenon that affects a wide range of engineering applications including power cables, radio masts, and wind turbines. Accretion on aircraft wings occurs when supercooled water droplets freeze instantaneously on impact to form rime ice or runback as water along the wing to form glaze ice. Most models to date have ignored the accretion of mixed ice, which is a combination of rime and glaze. A parameter we term the "freezing fraction" is defined as the fraction of a supercooled droplet that freezes on impact with the top surface of the accretion ice to explore the concept of mixed ice accretion. Additionally we consider different "packing densities" of rime ice, mimicking the different bulk rime densities observed in nature. Ice accretion is considered in four stages: rime, primary mixed, secondary mixed, and glaze ice. Predictions match with existing models and experimental data in the limiting rime and glaze cases. The mixed ice formulation however provides additional insight into the composition of the overall ice structure, which ultimately influences adhesion and ice thickness, and shows that for similar atmospheric parameter ranges, this simple mixed ice description leads to very different accretion rates. A simple one-dimensional energy balance was solved to show how this freezing fraction parameter increases with decrease in atmospheric temperature, with lower freezing fraction promoting glaze ice accretion.

  4. Ice nucleation activity of polysaccharides

    Science.gov (United States)

    Bichler, Magdalena; Felgitsch, Laura; Haeusler, Thomas; Seidl-Seiboth, Verena; Grothe, Hinrich

    2015-04-01

    Heterogeneous ice nucleation is an important process in the atmosphere. It shows direct impact on our climate by triggering ice cloud formation and therefore it has much influence on the radiation balance of our planet (Lohmann et al. 2002; Mishchenko et al. 1996). The process itself is not completely understood so far and many questions remain open. Different substances have been found to exhibit ice nucleation activity (INA). Due to their vast differences in chemistry and morphology it is difficult to predict what substance will make good ice nuclei and which will not. Hence simple model substances must be found and be tested regarding INA. Our work aims at gaining to a deeper understanding of heterogeneous ice nucleation. We intend to find some reference standards with defined chemistry, which may explain the mechanisms of heterogeneous ice nucleation. A particular focus lies on biological carbohydrates in regards to their INA. Biological carbohydrates are widely distributed in all kingdoms of life. Mostly they are specific for certain organisms and have well defined purposes, e.g. structural polysaccharides like chitin (in fungi and insects) and pectin (in plants), which has also water-binding properties. Since they are widely distributed throughout our biosphere and mostly safe to use for nutrition purposes, they are well studied and easily accessible, rendering them ideal candidates as proxies. In our experiments we examined various carbohydrates, like the already mentioned chitin and pectin, as well as their chemical modifications. Lohmann U.; A Glaciation Indirect Aerosol Effect Caused by Soot Aerosols; J. Geoph. Res.; Vol. 24 No.4; pp 11-1 - 11-4; 2002 Mishchenko M.I., Rossow W.B., Macke A., Lacis A. A.; Sensitivity of Cirrus Cloud Albedo, Bidirectional Reflectance and Optical Thickness Retrieval Accuracy to Ice Particle Shape, J. Geoph. Res.; Vol. 101, No D12; pp. 16,973 - 16,985; 1996

  5. Sensitivity of open-water ice growth and ice concentration evolution in a coupled atmosphere-ocean-sea ice model

    Science.gov (United States)

    Shi, Xiaoxu; Lohmann, Gerrit

    2017-09-01

    A coupled atmosphere-ocean-sea ice model is applied to investigate to what degree the area-thickness distribution of new ice formed in open water affects the ice and ocean properties. Two sensitivity experiments are performed which modify the horizontal-to-vertical aspect ratio of open-water ice growth. The resulting changes in the Arctic sea-ice concentration strongly affect the surface albedo, the ocean heat release to the atmosphere, and the sea-ice production. The changes are further amplified through a positive feedback mechanism among the Arctic sea ice, the Atlantic Meridional Overturning Circulation (AMOC), and the surface air temperature in the Arctic, as the Fram Strait sea ice import influences the freshwater budget in the North Atlantic Ocean. Anomalies in sea-ice transport lead to changes in sea surface properties of the North Atlantic and the strength of AMOC. For the Southern Ocean, the most pronounced change is a warming along the Antarctic Circumpolar Current (ACC), owing to the interhemispheric bipolar seasaw linked to AMOC weakening. Another insight of this study lies on the improvement of our climate model. The ocean component FESOM is a newly developed ocean-sea ice model with an unstructured mesh and multi-resolution. We find that the subpolar sea-ice boundary in the Northern Hemisphere can be improved by tuning the process of open-water ice growth, which strongly influences the sea ice concentration in the marginal ice zone, the North Atlantic circulation, salinity and Arctic sea ice volume. Since the distribution of new ice on open water relies on many uncertain parameters and the knowledge of the detailed processes is currently too crude, it is a challenge to implement the processes realistically into models. Based on our sensitivity experiments, we conclude a pronounced uncertainty related to open-water sea ice growth which could significantly affect the climate system sensitivity.

  6. Sea Ice Concentration and Extent

    Science.gov (United States)

    Comiso, Josefino C.

    2014-01-01

    Among the most seasonal and most dynamic parameters on the surface of the Earth is sea ice which at any one time covers about 3-6% of the planet. In the Northern Hemisphere, sea ice grows in extent from about 6 x 10(exp 6) sq km to 16 x 10(exp 6) sq km, while in the Southern Hemisphere, it grows from about 3 x 10(exp 6) sq km to about 19 x 10(exp 6) sq km (Comiso, 2010; Gloersen et al., 1992). Sea ice is up to about 2-3 m thick in the Northern Hemisphere and about 1 m thick in the Southern Hemisphere (Wadhams, 2002), and compared to the average ocean depth of about 3 km, it is a relatively thin, fragile sheet that can break due to waves and winds or melt due to upwelling of warm water. Being constantly advected by winds, waves, and currents, sea ice is very dynamic and usually follows the directions of the many gyres in the polar regions. Despite its vast expanse, the sea ice cover was previously left largely unstudied and it was only in recent years that we have understood its true impact and significance as related to the Earths climate, the oceans, and marine life.

  7. Ice-condenser aerosol tests

    International Nuclear Information System (INIS)

    Ligotke, M.W.; Eschbach, E.J.; Winegardner, W.K.

    1991-09-01

    This report presents the results of an experimental investigation of aerosol particle transport and capture using a full-scale height and reduced-scale cross section test facility based on the design of the ice compartment of a pressurized water reactor (PWR) ice-condenser containment system. Results of 38 tests included thermal-hydraulic as well as aerosol particle data. Particle retention in the test section was greatly influenced by thermal-hydraulic and aerosol test parameters. Test-average decontamination factor (DF) ranged between 1.0 and 36 (retentions between ∼0 and 97.2%). The measured test-average particle retentions for tests without and with ice and steam ranged between DF = 1.0 and 2.2 and DF = 2.4 and 36, respectively. In order to apparent importance, parameters that caused particle retention in the test section in the presence of ice were steam mole fraction (SMF), noncondensible gas flow rate (residence time), particle solubility, and inlet particle size. Ice-basket section noncondensible flows greater than 0.1 m 3 /s resulted in stable thermal stratification whereas flows less than 0.1 m 3 /s resulted in thermal behavior termed meandering with frequent temperature crossovers between flow channels. 10 refs., 66 figs., 16 tabs

  8. Ice-condenser aerosol tests

    Energy Technology Data Exchange (ETDEWEB)

    Ligotke, M.W.; Eschbach, E.J.; Winegardner, W.K. (Pacific Northwest Lab., Richland, WA (United States))

    1991-09-01

    This report presents the results of an experimental investigation of aerosol particle transport and capture using a full-scale height and reduced-scale cross section test facility based on the design of the ice compartment of a pressurized water reactor (PWR) ice-condenser containment system. Results of 38 tests included thermal-hydraulic as well as aerosol particle data. Particle retention in the test section was greatly influenced by thermal-hydraulic and aerosol test parameters. Test-average decontamination factor (DF) ranged between 1.0 and 36 (retentions between {approximately}0 and 97.2%). The measured test-average particle retentions for tests without and with ice and steam ranged between DF = 1.0 and 2.2 and DF = 2.4 and 36, respectively. In order to apparent importance, parameters that caused particle retention in the test section in the presence of ice were steam mole fraction (SMF), noncondensible gas flow rate (residence time), particle solubility, and inlet particle size. Ice-basket section noncondensible flows greater than 0.1 m{sup 3}/s resulted in stable thermal stratification whereas flows less than 0.1 m{sup 3}/s resulted in thermal behavior termed meandering with frequent temperature crossovers between flow channels. 10 refs., 66 figs., 16 tabs.

  9. Recrystallization inhibition in ice due to ice binding protein activity detected by nuclear magnetic resonance.

    Science.gov (United States)

    Brown, Jennifer R; Seymour, Joseph D; Brox, Timothy I; Skidmore, Mark L; Wang, Chen; Christner, Brent C; Luo, Bing-Hao; Codd, Sarah L

    2014-09-01

    Liquid water present in polycrystalline ice at the interstices between ice crystals results in a network of liquid-filled veins and nodes within a solid ice matrix, making ice a low porosity porous media. Here we used nuclear magnetic resonance (NMR) relaxation and time dependent self-diffusion measurements developed for porous media applications to monitor three dimensional changes to the vein network in ices with and without a bacterial ice binding protein (IBP). Shorter effective diffusion distances were detected as a function of increased irreversible ice binding activity, indicating inhibition of ice recrystallization and persistent small crystal structure. The modification of ice structure by the IBP demonstrates a potential mechanism for the microorganism to enhance survivability in ice. These results highlight the potential of NMR techniques in evaluation of the impact of IBPs on vein network structure and recrystallization processes; information useful for continued development of ice-interacting proteins for biotechnology applications.

  10. Ice lollies: An ice particle generated in supercooled conveyor belts

    Science.gov (United States)

    Keppas, S. Ch.; Crosier, J.; Choularton, T. W.; Bower, K. N.

    2017-05-01

    On 21 January 2009, a maturing low-pressure weather system approached the UK along with several associated frontal systems. As a part of the Aerosol Properties, PRocesses And InfluenceS on the Earth's climate-Clouds project, an observational research flight took place in southern England, sampling the leading warm front of this system. During the flight, a distinctive hydrometeor type was repeatedly observed which has not been widely reported in previous studies. We refer to the hydrometeors as "drizzle-rimed columnar ice" or "ice lollies" for short due to their characteristic shape. We discuss the processes that led to their formation using in situ and remote sensing data.

  11. Winter sea ice export from the Laptev Sea preconditions the local summer sea ice cover

    Science.gov (United States)

    Krumpen, T.; Haas, C.; Itkin, P.

    2016-12-01

    Interannual variability and trends in sea ice export out of the Laptev Sea were investigated using a combination of observations and satellite data. The Laptev Sea shows a statistically positive trend in ice area export that is likely associated to an increase in ice drift velocity being the consequence of a thinning ice cover further north. Moreover, we could show that there is a high statistical connection of the late winter (Jan-May) sea ice export and ice formation in Laptev Sea polynyas to the summer sea ice concentration. By means of a sensitivity study using a coupled sea ice-ocean model (MITgcm), we could highlight the importance of winter sea ice processes for summer sea ice conditions in the Laptev Sea and likewise in the adjacent Siberian Seas. Years of high ice export have a thinning effect on the ice cover, which in turn preconditions early fast ice break up, pack ice melt and the occurrence of negative sea ice extent anomalies in summer. Our model simulation also indicate that observed increase in the sea ice export from the Laptev Sea is accompanied by an increase in the volume export, which is important for the Arctic sea ice budget.

  12. Open-Source Python Modules to Estimate Level Ice Thickness from Ice Charts

    Science.gov (United States)

    Geiger, C. A.; Deliberty, T. L.; Bernstein, E. R.; Helfrich, S.

    2012-12-01

    A collaborative research effort between the University of Delaware (UD) and National Ice Center (NIC) addresses the task of providing open-source translations of sea ice stage-of-development into level ice thickness estimates on a 4km grid for the Interactive Multisensor Snow and Ice Mapping System (IMS). The characteristics for stage-of-development are quantified from remote sensing imagery with estimates of level ice thickness categories originating from World Meteorological Organization (WMO) egg coded ice charts codified since the 1970s. Conversions utilize Python scripting modules which transform electronic ice charts with WMO egg code characteristics into five level ice thickness categories, in centimeters, (0-10, 10-30, 30-70, 70-120, >120cm) and five ice types (open water, first year pack ice, fast ice, multiyear ice, and glacial ice with a reserve slot for deformed ice fractions). Both level ice thickness categories and ice concentration fractions are reported with uncertainties propagated based on WMO ice stage ranges which serve as proxy estimates for standard deviation. These products are in preparation for use by NCEP, CMC, and NAVO by 2014 based on their modeling requirements for daily products in near-real time. In addition to development, continuing research tests the value of these estimated products against in situ observations to improve both value and uncertainty estimates.

  13. Compression experiments on artificial, alpine and marine ice: implications for ice-shelf/continental interactions

    Science.gov (United States)

    Dierckx, Marie; Goossens, Thomas; Samyn, Denis; Tison, Jean-Louis

    2010-05-01

    Antarctic ice shelves are important components of continental ice dynamics, in that they control grounded ice flow towards the ocean. As such, Antarctic ice shelves are a key parameter to the stability of the Antarctic ice sheet in the context of global change. Marine ice, formed by sea water accretion beneath some ice shelves, displays distinct physical (grain textures, bubble content, ...) and chemical (salinity, isotopic composition, ...) characteristics as compared to glacier ice and sea ice. The aim is to refine Glen's flow relation (generally used for ice behaviour in deformation) under various parameters (temperature, salinity, debris, grain size ...) to improve deformation laws used in dynamic ice shelf models, which would then give more accurate and / or realistic predictions on ice shelf stability. To better understand the mechanical properties of natural ice, deformation experiments were performed on ice samples in laboratory, using a pneumatic compression device. To do so, we developed a custom built compression rig operated by pneumatic drives. It has been designed for performing uniaxial compression tests at constant load and under unconfined conditions. The operating pressure ranges from about 0.5 to 10 Bars. This allows modifying the experimental conditions to match the conditions found at the grounding zone (in the 1 Bar range). To maintain the ice at low temperature, the samples are immersed in a Silicone oil bath connected to an external refrigeration system. During the experiments, the vertical displacement of the piston and the applied force is measured by sensors which are connected to a digital acquisition system. We started our experiments with artificial ice and went on with continental ice samples from glaciers in the Alps. The first results allowed us to acquire realistic mechanical data for natural ice. Ice viscosity was calculated for different types of artificial ice, using Glen's flow law, and showed the importance of impurities

  14. Thermodynamic and Dynamic Aspects of Ice Nucleation

    Science.gov (United States)

    Barahona, Donifan

    2018-01-01

    It is known that ice nucleating particles (INP) immersed within supercooled droplets promote the formation of ice. Common theoretical models used to represent this process assume that the immersed particle lowers the work of ice nucleation without significantly affecting the dynamics of water in the vicinity of the particle. This is contrary to evidence showing that immersed surfaces significantly affect the viscosity and diffusivity of vicinal water. To study how this may affect ice formation this work introduces a model linking the ice nucleation rate to the modification of the dynamics and thermodynamics of vicinal water by immersed particles. It is shown that INP that significantly reduce the work of ice nucleation also pose strong limitations to the growth of the nascent ice germs. This leads to the onset of a new ice nucleation regime, called spinodal ice nucleation, where the dynamics of ice germ growth instead of the ice germ size determines the nucleation rate. Nucleation in this regime is characterized by an enhanced sensitivity to particle area and cooling rate. Comparison of the predicted ice nucleation rate against experimental measurements for a diverse set of species relevant to cloud formation suggests that spinodal ice nucleation may be common in nature.

  15. Proceedings of the 19. IAHR international symposium on ice : using new technology to understand water-ice interaction

    International Nuclear Information System (INIS)

    Jasek, M.; Andrishak, R.; Siddiqui, A.

    2008-01-01

    This conference provided a venue for scientists, engineers and researchers an opportunity to expand their knowledge of water-ice interactions with reference to water resources, river and coastal hydraulics, risk analysis, energy and the environment. The the theme of new technology falls into 3 basic groups, notably measurement and instrumentation; remote sensing; and numerical simulation. The thermal regime of rivers was discussed along with ice mechanics, ice hydraulics, ice structures and modelling ice phenomena. The titles of the sessions were: river ice, glaciers and climate change; freeze-up processes on rivers and oceans; river ice-structure interactions; numerical simulations in ice engineering; river-ice break-up and ice jam formation; ice measurement; Grasse River ice evaluation; evaluation of structural ice control alternatives; remote sensing; hydropower and dam decommissioning; mechanical behaviour of river ice, ice covered flow and thermal modelling; mathematical and computer model formulations for ice friction and sea ice; ice bergs and ice navigation; ice crushing processes; sea ice and shore/structure interactions; ice properties, testing and physical modelling; ice actions on compliant structures; oil spills in ice; desalination, ice thickness and climate change; and, sea ice ridges. The conference featured 123 presentations, of which 20 have been catalogued separately for inclusion in this database. refs., tabs., figs

  16. Disorder and Quantum Spin Ice

    Science.gov (United States)

    Martin, N.; Bonville, P.; Lhotel, E.; Guitteny, S.; Wildes, A.; Decorse, C.; Ciomaga Hatnean, M.; Balakrishnan, G.; Mirebeau, I.; Petit, S.

    2017-10-01

    We report on diffuse neutron scattering experiments providing evidence for the presence of random strains in the quantum spin-ice candidate Pr2Zr2O7 . Since Pr3 + is a non-Kramers ion, the strain deeply modifies the picture of Ising magnetic moments governing the low-temperature properties of this material. It is shown that the derived strain distribution accounts for the temperature dependence of the specific heat and of the spin-excitation spectra. Taking advantage of mean-field and spin-dynamics simulations, we argue that the randomness in Pr2Zr2O7 promotes a new state of matter, which is disordered yet characterized by short-range antiferroquadrupolar correlations, and from which emerge spin-ice-like excitations. Thus, this study gives an original research route in the field of quantum spin ice.

  17. Disorder and Quantum Spin Ice

    Directory of Open Access Journals (Sweden)

    N. Martin

    2017-10-01

    Full Text Available We report on diffuse neutron scattering experiments providing evidence for the presence of random strains in the quantum spin-ice candidate Pr_{2}Zr_{2}O_{7}. Since Pr^{3+} is a non-Kramers ion, the strain deeply modifies the picture of Ising magnetic moments governing the low-temperature properties of this material. It is shown that the derived strain distribution accounts for the temperature dependence of the specific heat and of the spin-excitation spectra. Taking advantage of mean-field and spin-dynamics simulations, we argue that the randomness in Pr_{2}Zr_{2}O_{7} promotes a new state of matter, which is disordered yet characterized by short-range antiferroquadrupolar correlations, and from which emerge spin-ice-like excitations. Thus, this study gives an original research route in the field of quantum spin ice.

  18. PU-ICE Summary Information.

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Michael [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-05-01

    The Generator Knowledge Report for the Plutonium Isentropic Compression Experiment Containment Systems (GK Report) provides information for the Plutonium Isentropic Compression Experiment (Pu- ICE) program to support waste management and characterization efforts. Attachment 3-18 presents generator knowledge (GK) information specific to the eighteenth Pu-ICE conducted in August 2015, also known as ‘Shot 18 (Aug 2015) and Pu-ICE Z-2841 (1).’ Shot 18 (Aug 2015) was generated on August 28, 2015 (1). Calculations based on the isotopic content of Shot 18 (Aug 2015) and the measured mass of the containment system demonstrate the post-shot containment system is low-level waste (LLW). Therefore, this containment system will be managed at Sandia National Laboratory/New Mexico (SNL/NM) as LLW. Attachment 3-18 provides documentation of the TRU concentration and documents the concentration of any hazardous constituents.

  19. Heavy Metal Presence in Two Different Types of Ice Cream: Artisanal Ice Cream (Italian Gelato) and Industrial Ice Cream.

    Science.gov (United States)

    Conficoni, D; Alberghini, L; Bissacco, E; Ferioli, M; Giaccone, V

    2017-03-01

    Ice cream, a popular product worldwide, is usually a milk-based product with other types of ingredients (fruit, eggs, cocoa, dried fruit, additives, and others). Different materials are used to obtain the desired taste, texture, consistency, and appearance of the final product. This study surveyed ice cream products available in Italy for heavy metals (lead, cadmium, chromium, tin, and arsenic). The differences between artisanal and industrial ice cream were also investigated because of the importance in the Italian diet and the diffusion of this ready-to-eat food. Ice cream sampling was performed between October 2010 and February 2011 in the northeast of Italy. A total of 100 samples were randomly collected from different sources: 50 industrial samples produced by 19 different brands were collected in coffee bars and supermarkets; 50 artisanal ice cream samples were gathered at nine different artisanal ice cream shops. Ten wooden sticks of industrial ice cream were analyzed in parallel to the ice cream. All samples were negative for arsenic and mercury. None of the artisanal ice cream samples were positive for lead and tin; 18% of the industrial ice cream samples were positive. All positive lead samples were higher than the legal limit stated for milk (0.02 mg/kg). All industrial ice cream samples were negative for cadmium, but cadmium was present in 10% of the artisanal ice cream samples. Chromium was found in 26% of the artisanal and in 58% of the industrial ice cream samples. The heavy metals found in the wooden sticks were different from the corresponding ice cream, pointing out the lack of cross-contamination between the products. Considering the results and the amount of ice cream consumed during the year, contamination through ice cream is a low risk for the Italian population, even though there is need for further analysis.

  20. Changes on the ice plain of Ice Stream B and Ross Ice Shelf

    Science.gov (United States)

    Shabtaie, Sion

    1993-01-01

    During the 1970's and 1980's, nearly 200 stations from which accurate, three dimensional position fixes have been obtained from TRANSIT satellites were occupied throughout the Ross Ice Shelf. We have transformed the elevations obtained by satellite altimetry to the same geodetic datum, and then applied a second transformation to reduce the geodetic heights to elevations above mean sea level using the GEM-10C geoidal height. On the IGY Ross Ice Shelf traverse between Oct. 1957 and Feb. 1958, an accurate method of barometric altimetry was used on a loop around the ice shelf that was directly tied to the sea at both ends of the travel route, thus providing absolute elevations. Comparisons of the two sets of data at 32 station pairs on floating ice show a mean difference of 0 +/- 1 m. The elevation data were also compared with theoretical values of elevations for a hydrostatically floating ice shelf. The mean difference between theoretical and measured values of elevations is -2 +/- 1 m.

  1. Airfields on Antarctic Glacier Ice

    Science.gov (United States)

    1989-12-01

    meteorites behind on the surface. excellent friction for tires, to the extent that rubber can be burned off the tire if the wheel locks at high Blue-ice areas...scattered stones are not likely to affect aircraft just a thin layer (about cobblestone thickness) ly- operations, or to cause problems for ice-planing ing...Challenger, tinations. Some sites, e.g. Pegasus site and Casey which has a novel rubber -belt track system, is S-1, are final destinations, intended to

  2. Arctic Landfast Sea Ice 1953-1998

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The files in this data set contain landfast sea ice data (monthly means) gathered from both Russian Arctic and Antarctic Research Institute (AARI) and Canadian Ice...

  3. RIDES: Raman Icing Detection System, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Inflight icing of engines and airframe presents a significant hazard to air transport, especially at lower flight elevations during take-off or on approach. Ice...

  4. Monthly snow/ice averages (ISCCP)

    Data.gov (United States)

    National Aeronautics and Space Administration — September Arctic sea ice is now declining at a rate of 11.5 percent per decade, relative to the 1979 to 2000 average. Data from NASA show that the land ice sheets in...

  5. IceBridge Mission Flight Reports

    Data.gov (United States)

    National Aeronautics and Space Administration — The IceBridge Mission Flight Reports data set contains flight reports from NASA Operation IceBridge Greenland, Arctic, Antarctic, and Alaska missions. Flight reports...

  6. ROV dives under Great Lakes ice

    Science.gov (United States)

    Bolsenga, S.J.; Gannon, John E.; Kennedy, Gregory; Norton, D.C.; Herdendorf, Charles E.

    1989-01-01

    Observations of the underside of ice have a wide variety of applications. Severe under-ice roughness can affect ice movements, rough under-ice surfaces can scour the bottom disturbing biota and man-made structures such as pipelines, and the flow rate of rivers is often affected by under-ice roughness. A few reported observations of the underside of an ice cover have been made, usually by cutting a large block of ice and overturning it, by extensive boring, or by remote sensing. Such operations are extremely labor-intensive and, in some cases, prone to inaccuracies. Remotely operated vehicles (ROV) can partially solve these problems. In this note, we describe the use, performance in a hostile environment, and results of a study in which a ROV was deployed under the ice in Lake Erie (North American Great Lakes).

  7. Greenland Radar Ice Sheet Thickness Measurements

    Data.gov (United States)

    National Aeronautics and Space Administration — Two 150-MHz coherent radar depth sounders were developed and flown over the Greenland ice sheet to obtain ice thickness measurements in support of PARCA...

  8. Global Lake and River Ice Phenology Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Global Lake and River Ice Phenology Database contains freeze and thaw/breakup dates as well as other descriptive ice cover data for 865 lakes and rivers in the...

  9. Ice nucleation and overseeding of ice in volcanic clouds

    Science.gov (United States)

    Durant, A. J.; Shaw, R. A.; Rose, W. I.; Mi, Y.; Ernst, G. G. J.

    2008-05-01

    Water is the dominant component of volcanic gas emissions, and water phase transformations, including the formation of ice, can be significant in the dynamics of volcanic clouds. The effectiveness of volcanic ash particles as ice-forming nuclei (IN) is poorly understood and the sparse data that exist for volcanic ash IN have been interpreted in the context of meteorological, rather than volcanic clouds. In this study, single-particle freezing experiments were carried out to investigate the effect of ash particle composition and surface area on water drop freezing temperature. Measured freezing temperatures show only weak correlations with ash IN composition and surface area. Our measurements, together with a review of previous volcanic ash IN measurements, suggest that fine-ash particles (equivalent diameters between approximately 1 and 1000 μm) from the majority of volcanoes will exhibit an onset of freezing between ˜250-260 K. In the context of explosive eruptions where super-micron particles are plentiful, this result implies that volcanic clouds are IN-rich relative to meteorological clouds, which typically are IN-limited, and therefore should exhibit distinct microphysics. We can expect that such "overseeded" volcanic clouds will exhibit enhanced ice crystal concentrations and smaller average ice crystal size, relative to dynamically similar meteorological clouds, and that glaciation will tend to occur over a relatively narrow altitude range.

  10. Ice sheet anisotropy measured with polarimetric ice sounding radar

    DEFF Research Database (Denmark)

    Dall, Jørgen

    2010-01-01

    For polar ice sheets, valuable stress and strain information can be deduced from crystal orientation fabrics (COF) and their prevailing c-axis alignment. Polarimetric radio echo sounding is a promising technique to measure the anisotropic electromagnetic propagation and reflection properties asso...

  11. Delicious ice cream, why does salt thaw ice?

    Science.gov (United States)

    Bagnoli, Franco

    2016-03-01

    Plain Awful is an imaginary valley on the Andes populated by a highly-imitative, cubical people for which the most criminal offence is to exhibit round objects. The duck family (Scrooge, Donald and nephews) are teaming against Scrooge's worst enemy, Flintheart Glomgold, trying to buy the famous Plain Awful square eggs. Inadvertently, Scrooge violates the taboo, showing his Number One Dime, and is imprisoned in the stone quarries. He can be released only after the presentation of an ice cream soda to the President of Plain Awful. Donald and his nephews fly with Flintheart to deliver it, but Scrooge's enemy, of course, betrays the previous agreement after getting the ice cream, forcing the ducks into making an emergence replacement on the spot. Using dried milk, sugar and chocolate from their ration packs, plus some snow and salt for cooling they are able make the ice cream, and after dressing it with the carbonated water from a fire extinguisher they finally manage to produce the desired dessert. This comic may serve as an introduction to the "mysterious" phenomenon that added salt melts the ice and, even more surprising, does it by lowering the temperature of the mixture.

  12. Passive Polarimetric Remote Sensing of Snow and Ice

    Science.gov (United States)

    1997-09-30

    ice and snow, we proposed to measure the Stokes parameters, as a function of incidence angle, for growing ice, desalinated ice, new snow, and...orientation of ice crystals, brine channels and air pockets. Although the CRREL facility is well equipped to artificially generate ice (via refrigeration of...calibration and early growth phase of new ice (See figure 2) 26-Feb Growth phase of new ice 26-Feb Old, desalinated ice (See figure 3) Slight surface

  13. The last British-Irish Ice Sheet: A data-rich environment for ice sheet modelling

    Science.gov (United States)

    Ely, Jeremy; Clark, Chris; Hindmarsh, Richard; Bradley, Sarah

    2017-04-01

    In order to simulate the future dynamics of the Greenland and Antarctic ice sheets, robust numerical models validated by observations of past ice sheet behaviour are required. The extent and dynamics of contemporary ice sheets have been observed at a decadal scale. But a much longer record of ice sheet behaviour (10 ka) can be collated by studying the evidence left behind by palaeo-ice sheets. Extensive geomorphological and geochronological evidence for the past behaviour of the last British-Irish Ice Sheet has been gathered through over 150 years of research and BRITICE-CHRONO, a recent consortium project. This large volume of empirical evidence makes the last British-Irish Ice Sheet one of the best constrained palaeo-ice sheets in the world, and a data-rich environment for ice sheet modelling experiments. Yet, integrating this data and its associated uncertainty and abstraction into ice sheet modelling experiments remains challenging. Here we summarise the available geomorphological and geochronological data and discuss how this will be integrated into ice sheet modelling experiments. Several packages of data, each with its own associated level of interpretation (ranging from raw data to empirically reconstructed ice sheet margins), will be made available to the ice-sheet modelling community. Furthermore, we demonstrate our approach to simulating the empirically reconstructed behaviour of the British-Irish Ice Sheet through a series of ice sheet modelling experiments which account for relative sea level change, and uncertainty in empirically reconstructed ice sheet extent.

  14. Acquisition of Ice Thickness and Ice Surface Characteristics In the Seasonal Ice Zone by CULPIS-X During the US Coast Guards Arctic Domain Awareness Program

    Science.gov (United States)

    2015-09-30

    ponds on thinner ice are often darker, accelerating the ice - albedo feedback over thin ice in summer. During winter, leads and very thin ice are centers...1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Acquisition of Ice Thickness and Ice Surface...Characteristics In the Seasonal Ice Zone by CULPIS-X During the US Coast Guard’s Arctic Domain Awareness Program PI: Mark A. Tschudi University of

  15. Research destruction ice under dynamic loading. Part 1. Modeling explosive ice cover into account the temperature

    Directory of Open Access Journals (Sweden)

    Bogomolov Gennady N.

    2017-01-01

    Full Text Available In the research, the behavior of ice under shock and explosive loads is analyzed. Full-scale experiments were carried out. It is established that the results of 2013 practically coincide with the results of 2017, which is explained by the temperature of the formation of river ice. Two research objects are considered, including freshwater ice and river ice cover. The Taylor test was simulated numerically. The results of the Taylor test are presented. Ice is described by an elastoplastic model of continuum mechanics. The process of explosive loading of ice by emulsion explosives is numerically simulated. The destruction of the ice cover under detonation products is analyzed in detail.

  16. Development of a Capacitive Ice Sensor to Measure Ice Growth in Real Time

    Directory of Open Access Journals (Sweden)

    Xiang Zhi

    2015-03-01

    Full Text Available This paper presents the development of the capacitive sensor to measure the growth of ice on a fuel pipe surface in real time. The ice sensor consists of pairs of electrodes to detect the change in capacitance and a thermocouple temperature sensor to examine the ice formation situation. In addition, an environmental chamber was specially designed to control the humidity and temperature to simulate the ice formation conditions. From the humidity, a water film is formed on the ice sensor, which results in an increase in capacitance. Ice nucleation occurs, followed by the rapid formation of frost ice that decreases the capacitance suddenly. The capacitance is saturated. The developed ice sensor explains the ice growth providing information about the icing temperature in real time.

  17. Development of a capacitive ice sensor to measure ice growth in real time.

    Science.gov (United States)

    Zhi, Xiang; Cho, Hyo Chang; Wang, Bo; Ahn, Cheol Hee; Moon, Hyeong Soon; Go, Jeung Sang

    2015-03-19

    This paper presents the development of the capacitive sensor to measure the growth of ice on a fuel pipe surface in real time. The ice sensor consists of pairs of electrodes to detect the change in capacitance and a thermocouple temperature sensor to examine the ice formation situation. In addition, an environmental chamber was specially designed to control the humidity and temperature to simulate the ice formation conditions. From the humidity, a water film is formed on the ice sensor, which results in an increase in capacitance. Ice nucleation occurs, followed by the rapid formation of frost ice that decreases the capacitance suddenly. The capacitance is saturated. The developed ice sensor explains the ice growth providing information about the icing temperature in real time.

  18. 21 CFR 135.160 - Water ices.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Water ices. 135.160 Section 135.160 Food and Drugs... CONSUMPTION FROZEN DESSERTS Requirements for Specific Standardized Frozen Desserts § 135.160 Water ices. (a) Description. Water ices are the foods each of which is prepared from the same ingredients and in the same...

  19. CICE, The Los Alamos Sea Ice Model

    Energy Technology Data Exchange (ETDEWEB)

    2017-05-12

    The Los Alamos sea ice model (CICE) is the result of an effort to develop a computationally efficient sea ice component for a fully coupled atmosphere–land–ocean–ice global climate model. It was originally designed to be compatible with the Parallel Ocean Program (POP), an ocean circulation model developed at Los Alamos National Laboratory for use on massively parallel computers. CICE has several interacting components: a vertical thermodynamic model that computes local growth rates of snow and ice due to vertical conductive, radiative and turbulent fluxes, along with snowfall; an elastic-viscous-plastic model of ice dynamics, which predicts the velocity field of the ice pack based on a model of the material strength of the ice; an incremental remapping transport model that describes horizontal advection of the areal concentration, ice and snow volume and other state variables; and a ridging parameterization that transfers ice among thickness categories based on energetic balances and rates of strain. It also includes a biogeochemical model that describes evolution of the ice ecosystem. The CICE sea ice model is used for climate research as one component of complex global earth system models that include atmosphere, land, ocean and biogeochemistry components. It is also used for operational sea ice forecasting in the polar regions and in numerical weather prediction models.

  20. Anti-icing performance of superhydrophobic surfaces

    Science.gov (United States)

    Farhadi, S.; Farzaneh, M.; Kulinich, S. A.

    2011-05-01

    This article studies the anti-ice performance of several micro/nano-rough hydrophobic coatings with different surface chemistry and topography. The coatings were prepared by spin-coating or dip coating and used organosilane, fluoropolymer or silicone rubber as a top layer. Artificially created glaze ice, similar to the naturally accreted one, was deposited on the nanostructured surfaces by spraying supercooled water microdroplets (average size ˜80 μm) in a wind tunnel at subzero temperature (-10 °C). The ice adhesion strength was evaluated by spinning the samples in a centrifuge at constantly increasing speed until ice delamination occurred. The results show that the anti-icing properties of the tested materials deteriorate, as their surface asperities seem to be gradually broken during icing/de-icing cycles. Therefore, the durability of anti-icing properties appears to be an important point for further research. It is also shown that the anti-icing efficiency of the tested superhydrophobic surfaces is significantly lower in a humid atmosphere, as water condensation both on top and between surface asperities takes place, leading to high values of ice adhesion strength. This implies that superhydrophobic surfaces may not always be ice-phobic in the presence of humidity, which can limit their wide use as anti-icing materials.

  1. The Last Arctic Sea Ice Refuge

    Science.gov (United States)

    Pfirman, S. L.; Tremblay, B.; Newton, R.; Fowler, C.

    2010-12-01

    Summer sea ice may persist along the northern flank of Canada and Greenland for decades longer than the rest of the Arctic, raising the possibility of a naturally formed refugium for ice-associated species. Observations and models indicate that some ice in this region forms locally, while some is transported to the area by winds and ocean currents. Depending on future changes in melt patterns and sea ice transport rates, both the central Arctic and Siberian shelf seas may be sources of ice to the region. An international system of monitoring and management of the sea ice refuge, along with the ice source regions, has the potential to maintain viable habitat for ice-associated species, including polar bears, for decades into the future. Issues to consider in developing a strategy include: + the likely duration and extent of summer sea ice in this region based on observations, models and paleoenvironmental information + the extent and characteristics of the “ice shed” contributing sea ice to the refuge, including its dynamics, physical and biological characteristics as well as potential for contamination from local or long-range sources + likely assemblages of ice-associated species and their habitats + potential stressors such as transportation, tourism, resource extraction, contamination + policy, governance, and development issues including management strategies that could maintain the viability of the refuge.

  2. On the origin of the ice ages

    NARCIS (Netherlands)

    Oerlemans, J.

    1984-01-01

    Ice sheet dynamics provide a possible explanation for the 100 kyr power in climatic records. Some numerical experiments presented here show that even the transition from an essentially ice-free earth to a glacial can be produced by a northern hemisphere ice-sheet model, provided that a

  3. Balance of the West Antarctic Ice Sheet

    Science.gov (United States)

    2002-01-01

    For several decades, measurements of the West Antarctic Ice Sheet showed it to be retreating rapidly. But new data derived from satellite-borne radar sensors show the ice sheet to be growing. Changing Antarctic ice sheets remains an area of high scientific interest, particularly in light of recent global warming concerns. These new findings are significant because scientists estimate that sea level would rise 5-6 meters (16-20 feet) if the ice sheet collapsed into the sea. Do these new measurements signal the end of the ice sheet's 10,000-year retreat? Or, are these new satellite data simply much more accurate than the sparse ice core and surface measurements that produced the previous estimates? Another possibility is that the ice accumulation may simply indicate that the ice sheet naturally expands and retreats in regular cycles. Cryologists will grapple with these questions, and many others, as they examine the new data. The image above depicts the region of West Antarctica where scientists measured ice speed. The fast-moving central ice streams are shown in red. Slower tributaries feeding the ice streams are shown in blue. Green areas depict slow-moving, stable areas. Thick black lines depict the areas that collect snowfall to feed their respective ice streams. Reference: Ian Joughin and Slawek Tulaczyk Science Jan 18 2002: 476-480. Image courtesy RADARSAT Antarctic Mapping Project

  4. Tree recovery from ice storm injury

    Science.gov (United States)

    Kevin T. Smith

    2015-01-01

    Ice storms are part of nature, particularly in northeastern North America. The combination of air and surface temperatures, precipitation, and wind that result in damaging layers of ice is very specific, occurring infrequently at any given location. Across the region however, damaging ice is formed in fragmented areas every year. Occasionally as in December 2013 and...

  5. Arctic Ice Algae Distribution as Function of Large Scale Sea Ice Variables

    Science.gov (United States)

    Flores, H.; Castellani, G.; Lange, B. A.; David, C.; Katlein, C.; Peeken, I.; Nicolaus, M.; Losch, M. J.; van Franeker, J. A.

    2016-02-01

    One of the most pronounced impacts of climate change is the declining sea ice cover in the Arctic Ocean, which has implications for sea-ice associated ecosystems that are strongly dependent on carbon produced by ice algae. In order to understand these ecosystems there is a need to understand the interaction between the physical and biological components of sea ice. Our current understanding of Arctic sea ice algae is based on observations with limited spatial coverage. Therefore, we aim to model the spatial distribution of ice-algae on a basin scale. Current sea-ice-ocean models do allow the representation of sea-ice variability on a scale of few km. Large scale characteristics of sea ice such as age, deformation, and snow cover, do affect the small scale ice properties, such as salinity, porosity, light transmission. The latter directly affect the sea ice algae content, but to what extent is not yet well understood. In this work we present a new parameterization for the sea-ice algae content developed with the aim to model the algae content and variability based on large scale sea-ice characteristics. This parameterization is tuned with data collected during a ship-based campaign to the Eastern Central Arctic in summer 2012. Sea-ice thickness and under-ice spectral surveys over different sea ice regimes were conducted with a Surface and Under Ice Trawl (SUIT) and a Remote Operated Vehicle (ROV). In addition, ice cores were extracted at several sites for chl a analysis. We use a coupled sea-ice-ocean model with a spatial scale of 10 km and we show here the results for the temporal evolution of algae content in sea ice.

  6. Response of passive microwave sea ice concentration algorithms to thin ice

    DEFF Research Database (Denmark)

    Heygster, Georg; Huntemann, Marcus; Ivanova, Natalia

    2014-01-01

    The influence of sea ice thickness brightness temperatures and ice concentrations retrieved from passive microwave observations is quantified, using horizontally homogeneous sea ice thickness retrievals from ESA's SMOS sensor observations at high incidence angles. Brightness temperatures...... are influenced by thickness below 18 cm (89GHz) and 50 cm (1.4 GHz). Ice concentration retrievals reduced by ice thickness below 0.17 m and 0.33 m, with higher frequency algorithms being less influenced....

  7. Development of a Capacitive Ice Sensor to Measure Ice Growth in Real Time

    OpenAIRE

    Zhi, Xiang; Cho, Hyo Chang; Wang, Bo; Ahn, Cheol Hee; Moon, Hyeong Soon; Go, Jeung Sang

    2015-01-01

    This paper presents the development of the capacitive sensor to measure the growth of ice on a fuel pipe surface in real time. The ice sensor consists of pairs of electrodes to detect the change in capacitance and a thermocouple temperature sensor to examine the ice formation situation. In addition, an environmental chamber was specially designed to control the humidity and temperature to simulate the ice formation conditions. From the humidity, a water film is formed on the ice sensor, which...

  8. Women of Ice and Fire

    DEFF Research Database (Denmark)

    The anthology offers 11 original contributions about the women in GoT, the transmedial universe of George R.R. Martin's book series A Song of Ice and Fire, the HBO TV series Game of Thrones, computer games and online fan activities. The anthology examines the representation of women, and activity...

  9. Medical ice slurry production device

    Science.gov (United States)

    Kasza, Kenneth E [Palos Park, IL; Oras, John [Des Plaines, IL; Son, HyunJin [Naperville, IL

    2008-06-24

    The present invention relates to an apparatus for producing sterile ice slurries for medical cooling applications. The apparatus is capable of producing highly loaded slurries suitable for delivery to targeted internal organs of a patient, such as the brain, heart, lungs, stomach, kidneys, pancreas, and others, through medical size diameter tubing. The ice slurry production apparatus includes a slurry production reservoir adapted to contain a volume of a saline solution. A flexible membrane crystallization surface is provided within the slurry production reservoir. The crystallization surface is chilled to a temperature below a freezing point of the saline solution within the reservoir such that ice particles form on the crystallization surface. A deflector in the form of a reciprocating member is provided for periodically distorting the crystallization surface and dislodging the ice particles which form on the crystallization surface. Using reservoir mixing the slurry is conditioned for easy pumping directly out of the production reservoir via medical tubing or delivery through other means such as squeeze bottles, squeeze bags, hypodermic syringes, manual hand delivery, and the like.

  10. Women of Ice and Fire

    DEFF Research Database (Denmark)

    George R.R. Martin's acclaimed seven-book fantasy series A Song of Ice and Fire is unique for its strong and multi-faceted female protagonists, from teen queen Daenerys, scheming Queen Cersei, child avenger Arya, knight Brienne, Red Witch Melisandre, and many more. The Game of Thrones universe...

  11. Facility for testing ice drills

    Science.gov (United States)

    Nielson, Dennis L.; Delahunty, Chris; Goodge, John W.; Severinghaus, Jeffery P.

    2017-05-01

    The Rapid Access Ice Drill (RAID) is designed for subsurface scientific investigations in Antarctica. Its objectives are to drill rapidly through ice, to core samples of the transition zone and bedrock, and to leave behind a borehole observatory. These objectives required the engineering and fabrication of an entirely new drilling system that included a modified mining-style coring rig, a unique fluid circulation system, a rod skid, a power unit, and a workshop with areas for the storage of supplies and consumables. An important milestone in fabrication of the RAID was the construction of a North American Test (NAT) facility where we were able to test drilling and fluid processing functions in an environment that is as close as possible to that expected in Antarctica. Our criteria for site selection was that the area should be cold during the winter months, be located in an area of low heat flow, and be at relatively high elevation. We selected a site for the facility near Bear Lake, Utah, USA. The general design of the NAT well (NAT-1) started with a 27.3 cm (10.75 in.) outer casing cemented in a 152 m deep hole. Within that casing, we hung a 14 cm (5.5 in.) casing string, and, within that casing, a column of ice was formed. The annulus between the 14 and 27.3 cm casings provided the path for circulation of a refrigerant. After in-depth study, we chose to use liquid CO2 to cool the hole. In order to minimize the likelihood of the casing splitting due to the volume increase associated with freezing water, the hole was first cooled and then ice was formed in increments from the bottom upward. First, ice cubes were placed in the inner liner and then water was added. Using this method, a column of ice was incrementally prepared for drilling tests. The drilling tests successfully demonstrated the functioning of the RAID system. Reproducing such a facility for testing of other ice drilling systems could be advantageous to other research programs in the future.

  12. The Rapidly Shrinking Arctic Multiyear Ice Cover

    Science.gov (United States)

    Comiso, Josefino C.

    2010-01-01

    Among the most dramatic changes in the Arctic in recent years was the precipitous decline in the perennial ice cover. In 2007, the perennial ice area was 37% lower than climatological average and 28% lower than the previous low established in 2005. In 2008, the perennial ice recovered somewhat because of colder global temperatures but by only about 6% of average value. The trend in the ice area covered by perennial ice is now -12.5% per decade using data from 1979 to 2009 which compared to a previous report of -9% per decade derived from 1979 to 2000 data indicates an accelerated decline. To gain insight into the phenomenon, we studied the mUltiyear ice cover as detected by satellite sensor in winter. The multiyear ice as detected in winter represents ice that has generally survived two summers and therefore the thicker component of the perennial ice cover. Analysis of the thicker multiyear ice types indicates an even more rapid decline of 17% per decade. Such decline in the thick component of the Arctic ice cover that normally survives the summer means an even more vulnerable perennial ice cover. Much of the decline occurred in the western region of the Arctic Basin (Le., Chukchi and Beaufort Seas) where the open water area has been increasing by about 35% per decade. Such increase in low albedo ice free region causes the absorption of considerably more solar heat in the Arctic basin. This causes further decline in the ice cover in a process called ice-albedo feedback. A manifestation of such process is the observed trend in SST in the basin of about 0.5 + 0.2 degrees Celsius per decade as derived from satellite data

  13. Ice formation and growth shape bacterial community structure in Baltic Sea drift ice.

    Science.gov (United States)

    Eronen-Rasimus, Eeva; Lyra, Christina; Rintala, Janne-Markus; Jürgens, Klaus; Ikonen, Vilma; Kaartokallio, Hermanni

    2015-02-01

    Drift ice, open water and under-ice water bacterial communities covering several developmental stages from open water to thick ice were studied in the northern Baltic Sea. The bacterial communities were assessed with 16S rRNA gene terminal-restriction fragment length polymorphism and cloning, together with bacterial abundance and production measurements. In the early stages, open water and pancake ice were dominated by Alphaproteobacteria and Actinobacteria, which are common bacterial groups in Baltic Sea wintertime surface waters. The pancake ice bacterial communities were similar to the open-water communities, suggesting that the parent water determines the sea-ice bacterial community in the early stages of sea-ice formation. In consolidated young and thick ice, the bacterial communities were significantly different from water bacterial communities as well as from each other, indicating community development in Baltic Sea drift ice along with ice-type changes. The thick ice was dominated by typical sea-ice genera from classes Flavobacteria and Gammaproteobacteria, similar to those in polar sea-ice bacterial communities. Since the thick ice bacterial community was remarkably different from that of the parent seawater, results indicate that thick ice bacterial communities were recruited from the rarer members of the seawater bacterial community. © FEMS 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. Modeling the formation and deposition of frazil ice beneath Filchner-Ronne Ice Shelf

    Science.gov (United States)

    Bombosch, Andreas; Jenkins, Adrian

    1995-04-01

    Large areas of the Filchner-Ronne Ice Shelf are underlain by layers of marine ice, which form when supercooled seawater circulating beneath the ice shelf freezes. The freezing process initially produces a suspension of disc-shaped frazil ice crystals, and these are subs quently deposited onto the ice shelf base in areas where the flow of water is slack enough. This has been modeled assuming that the freezing takes place within buoyant plumes of Ice Shelf Water ascending the ice shelf base from source regions near the grounding lines of the major inlet glaciers. The deposition of the majority of the suspended frazil ice is found to occur in spatially discrete bursts, where peak rates of accumulation at the ice shelf base exceed 1 m yr-1 of solid ice. There is a good correlation between the location of the zones of crystal deposition and the position of the upstream limits of the marine ice layers. The high rates of localized accumulation account for the rapid buildup observed in the layer thickness, which then gradually declines as the marine ice is carried downstream with the flow of the ice shelf. Model results also suggest an origin for the ice platelets observed at depth in the water column near the Filchner Ice Shelf.

  15. Inner Phases of Colloidal Hexagonal Spin Ice

    Science.gov (United States)

    Libál, A.; Nisoli, C.; Reichhardt, C. J. O.; Reichhardt, C.

    2018-01-01

    Using numerical simulations that mimic recent experiments on hexagonal colloidal ice, we show that colloidal hexagonal artificial spin ice exhibits an inner phase within its ice state that has not been observed previously. Under increasing colloid-colloid repulsion, the initially paramagnetic system crosses into a disordered ice regime, then forms a topologically charge ordered state with disordered colloids, and finally reaches a threefold degenerate, ordered ferromagnetic state. This is reminiscent of, yet distinct from, the inner phases of the magnetic kagome spin ice analog. The difference in the inner phases of the two systems is explained by their difference in energetics and frustration.

  16. NASA/FAA Tailplane Icing Program Overview

    Science.gov (United States)

    Ratvasky, Thomas P.; VanZante, Judith Foss; Riley, James T.

    1999-01-01

    The effects of tailplane icing were investigated in a four-year NASA/FAA Tailplane Icing, Program (TIP). This research program was developed to improve the understanding, of iced tailplane aeroperformance and aircraft aerodynamics, and to develop design and training aides to help reduce the number of incidents and accidents caused by tailplane icing. To do this, the TIP was constructed with elements that included icing, wind tunnel testing, dry-air aerodynamic wind tunnel testing, flight tests, and analytical code development. This paper provides an overview of the entire program demonstrating the interconnectivity of the program elements and reports on current accomplishments.

  17. Comparison between GPR measurements and ultrasonic tomography with different inversion algorithms: an application to the base of an ancient Egyptian sculpture

    International Nuclear Information System (INIS)

    Sambuelli, L; Bohm, G; Capizzi, P; Cosentino, P; Cardarelli, E

    2011-01-01

    By late 2008 one of the most important pieces of the 'Museo delle Antichità Egizie' of Turin, the sculpture of the Pharaoh with god Amun, was planned to be one of the masterpieces of a travelling exhibition in Japan. The 'Fondazione Museo delle Antichità Egizie di Torino', who manages the museum, was concerned with the integrity of the base of the statue which actually presents visible signs of restoration dating back to the early 19th century. It was required to estimate the persistence of the visible fractures, to search for unknown ones and to provide information about the overall mechanical strength of the base. To tackle the first question a GPR reflection survey along three sides of the base was performed and the results were assembled in a 3D rendering. As far as the second question is concerned, two parallel, horizontal ultrasonic 2D tomograms across the base were made. We acquired, for each section, 723 ultrasonic signals corresponding to different transmitter and receiver positions. The tomographic data were inverted using four different software packages based upon different algorithms. The obtained velocity images were then compared each other, with the GPR results and with the visible fractures in the base. A critical analysis of the comparisons is finally presented

  18. Vapor deposited sculptured nano-porous titania films by glancing angle deposition for efficiency enhancement in dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Wong, Ming-Show; Lee, Ming-Fu; Chen, Ching-Lun; Huang, Chia-Hua

    2010-01-01

    Sculptured porous titania films as photoanode in dye-sensitized solar cell (DSSC) were prepared using an electron-beam evaporation system with glancing angle deposition (GLAD) method. By controlling the substrate rotation rate and the incident angle of evaporant, titania films of various thicknesses were prepared on ITO glasses. The as-deposited nano-porous films are comprised of helical nano-columns and assembled in an orderly manner with gaps or pores in between, which offer large internal surface area for dye adsorption and direct electron transfer path. There is a positive correlation between the film thickness, film effective surface area, amount of absorbed dye and cell efficiency. The nano-porous films provide a synergistic effect of high surface area, effective route for electron transfer, tight interfaces, and enhanced light trapping, which are all beneficial for higher cell efficiency. The DSSC consisting of a 6 μm titania film, deposited at substrate rotating rate 0.17 rpm and incident angle 73 o , gave a cell efficiency of 6.1%.

  19. Using the glacial geomorphology of palaeo-ice streams to understand mechanisms of ice sheet collapse

    Science.gov (United States)

    Stokes, Chris R.; Margold, Martin; Clark, Chris; Tarasov, Lev

    2017-04-01

    Processes which bring about ice sheet deglaciation are critical to our understanding of glacial-interglacial cycles and ice sheet sensitivity to climate change. The precise mechanisms of deglaciation are also relevant to our understanding of modern-day ice sheet stability and concerns over global sea level rise. Mass loss from ice sheets can be broadly partitioned between melting and a 'dynamic' component whereby rapidly-flowing ice streams/outlet glaciers transfer ice from the interior to the oceans. Surface and basal melting (e.g. of ice shelves) are closely linked to atmospheric and oceanic conditions, but the mechanisms that drive dynamic changes in ice stream discharge are more complex, which generates much larger uncertainties about their future contribution to ice sheet mass loss and sea level rise. A major problem is that observations of modern-day ice streams typically span just a few decades and, at the ice-sheet scale, it is unclear how the entire drainage network of ice streams evolves during deglaciation. A key question is whether ice streams might increase and sustain rates of mass loss over centuries or millennia, beyond those expected for a given ocean-climate forcing. To address this issue, numerous workers have sought to understand ice stream dynamics over longer time-scales using their glacial geomorphology in the palaeo-record. Indeed, our understanding of their geomorphology has grown rapidly in the last three decades, from almost complete ignorance to a detailed knowledge of their geomorphological products. Building on this body of work, this paper uses the glacial geomorphology of 117 ice streams in the North American Laurentide Ice Sheet to reconstruct their activity during its deglaciation ( 22,000 to 7,000 years ago). Ice stream activity was characterised by high variability in both time and space, with ice streams switching on and off in different locations. During deglaciation, we find that their overall number decreased, they occupied a

  20. There goes the sea ice: following Arctic sea ice parcels and their properties.

    Science.gov (United States)

    Tschudi, M. A.; Tooth, M.; Meier, W.; Stewart, S.

    2017-12-01

    Arctic sea ice distribution has changed considerably over the last couple of decades. Sea ice extent record minimums have been observed in recent years, the distribution of ice age now heavily favors younger ice, and sea ice is likely thinning. This new state of the Arctic sea ice cover has several impacts, including effects on marine life, feedback on the warming of the ocean and atmosphere, and on the future evolution of the ice pack. The shift in the state of the ice cover, from a pack dominated by older ice, to the current state of a pack with mostly young ice, impacts specific properties of the ice pack, and consequently the pack's response to the changing Arctic climate. For example, younger ice typically contains more numerous melt ponds during the melt season, resulting in a lower albedo. First-year ice is typically thinner and more fragile than multi-year ice, making it more susceptible to dynamic and thermodynamic forcing. To investigate the response of the ice pack to climate forcing during summertime melt, we have developed a database that tracks individual Arctic sea ice parcels along with associated properties as these parcels advect during the summer. Our database tracks parcels in the Beaufort Sea, from 1985 - present, along with variables such as ice surface temperature, albedo, ice concentration, and convergence. We are using this database to deduce how these thousands of tracked parcels fare during summer melt, i.e. what fraction of the parcels advect through the Beaufort, and what fraction melts out? The tracked variables describe the thermodynamic and dynamic forcing on these parcels during their journey. This database will also be made available to all interested investigators, after it is published in the near future. The attached image shows the ice surface temperature of all parcels (right) that advected through the Beaufort Sea region (left) in 2014.

  1. Initiation of secondary ice production in clouds

    Science.gov (United States)

    Sullivan, Sylvia C.; Hoose, Corinna; Kiselev, Alexei; Leisner, Thomas; Nenes, Athanasios

    2018-02-01

    Disparities between the measured concentrations of ice-nucleating particles (INPs) and in-cloud ice crystal number concentrations (ICNCs) have led to the hypothesis that mechanisms other than primary nucleation form ice in the atmosphere. Here, we model three of these secondary production mechanisms - rime splintering, frozen droplet shattering, and ice-ice collisional breakup - with a six-hydrometeor-class parcel model. We perform three sets of simulations to understand temporal evolution of ice hydrometeor number (Nice), thermodynamic limitations, and the impact of parametric uncertainty when secondary production is active. Output is assessed in terms of the number of primarily nucleated ice crystals that must exist before secondary production initiates (NINP(lim)) as well as the ICNC enhancement from secondary production and the timing of a 100-fold enhancement. Nice evolution can be understood in terms of collision-based nonlinearity and the phasedness of the process, i.e., whether it involves ice hydrometeors, liquid ones, or both. Ice-ice collisional breakup is the only process for which a meaningful NINP(lim) exists (0.002 up to 0.15 L-1). For droplet shattering and rime splintering, a warm enough cloud base temperature and modest updraft are the more important criteria for initiation. The low values of NINP(lim) here suggest that, under appropriate thermodynamic conditions for secondary ice production, perturbations in cloud concentration nuclei concentrations are more influential in mixed-phase partitioning than those in INP concentrations.

  2. Multi-decadal Arctic sea ice roughness.

    Science.gov (United States)

    Tsamados, M.; Stroeve, J.; Kharbouche, S.; Muller, J. P., , Prof; Nolin, A. W.; Petty, A.; Haas, C.; Girard-Ardhuin, F.; Landy, J.

    2017-12-01

    The transformation of Arctic sea ice from mainly perennial, multi-year ice to a seasonal, first-year ice is believed to have been accompanied by a reduction of the roughness of the ice cover surface. This smoothening effect has been shown to (i) modify the momentum and heat transfer between the atmosphere and ocean, (ii) to alter the ice thickness distribution which in turn controls the snow and melt pond repartition over the ice cover, and (iii) to bias airborne and satellite remote sensing measurements that depend on the scattering and reflective characteristics over the sea ice surface topography. We will review existing and novel remote sensing methodologies proposed to estimate sea ice roughness, ranging from airborne LIDAR measurement (ie Operation IceBridge), to backscatter coefficients from scatterometers (ASCAT, QUICKSCAT), to multi angle maging spectroradiometer (MISR), and to laser (Icesat) and radar altimeters (Envisat, Cryosat, Altika, Sentinel-3). We will show that by comparing and cross-calibrating these different products we can offer a consistent multi-mission, multi-decadal view of the declining sea ice roughness. Implications for sea ice physics, climate and remote sensing will also be discussed.

  3. Solar radiation interactions with seasonal sea ice

    Science.gov (United States)

    Ehn, Jens Kristian

    Presently, the Arctic Ocean is undergoing an escalating reduction in sea ice and a transition towards a seasonal sea ice environment. This warrants detailed investigations into improving our understanding of the seasonal evolution of sea ice and snow covers, and their representation in climate models. The interaction of solar radiation with sea ice is an important process influencing the energy balance and biological activity in polar seas, and consequently plays a key role in the earth's climate system. This thesis focuses on characterization of the optical properties---and the underlying physical properties that determine them---of seasonal sea ice during the fall freeze-up and the spring melt periods. Both periods display high spatial heterogeneity and rapid temporal changes in sea ice properties, and are therefore poorly understood. Field data were collected in Amundsen Gulf/Franklin Bay (FB), southern-eastern Beaufort Sea, in Oct.-Nov. 2003 and Apr. 2004 and in Button Bay (BB), western Hudson Bay, in Mar.-May 2005 to address (1) the temporal and spatial evolution of surface albedo and transmittance, (2) how radiative transfer in sea ice is controlled by its physical nature, and (3) the characteristics of the bottom ice algae community and its effect on the optical properties. The fall study showed the importance of surface features such as dry or slushy bare ice, frost flowers and snow cover in determining the surface albedo. Ice thickness was also important, however, mostly because surface features were associated with thickness. For example, nilas (brine skim layer on the surface, while surface conditions on thicker ice types were cold and dry enough to support a snow cover. In general, the surface albedo increased exponentially with an ice thickness increase, however, variability within ice thickness types were very large. It is apparent that a more complete treatment of brine movement towards the surface ice of the ice cover and the formation of surface

  4. ICESat: Ice, Cloud and Land Elevation Satellite

    Science.gov (United States)

    Zwally, Jay; Shuman, Christopher

    2002-01-01

    Ice exists in the natural environment in many forms. The Earth dynamic ice features shows that at high elevations and/or high latitudes,snow that falls to the ground can gradually build up tu form thick consolidated ice masses called glaciers. Glaciers flow downhill under the force of gravity and can extend into areas that are too warm to support year-round snow cover. The snow line, called the equilibrium line on a glacier or ice sheet, separates the ice areas that melt on the surface and become show free in summer (net ablation zone) from the ice area that remain snow covered during the entire year (net accumulation zone). Snow near the surface of a glacier that is gradually being compressed into solid ice is called firm.

  5. Evidence for radionuclide transport by sea ice

    International Nuclear Information System (INIS)

    Meese, D.A.; Tucker, W.B.; Gow, A.J.; Reimnitz, E.; Bischof, J.; Darby, D.

    1997-01-01

    Ice and ice-borne sediments were collected across the Arctic Basin during the Arctic Ocean Section, 1994 (AOS-94), a recent US/Canada trans-Arctic expedition. Sediments were analysed for 137 Cs, clay mineralogy and carbon. Concentrations of 137 Cs ranged from 5 to 73 Bq kg -1 in the ice-borne sediments. Concentrations of ice samples without sediment were all less than 1 Bq m -3 . The sediment sample with the highest 137 Cs concentration (73 Bq kg -1 ) was collected in the Beaufort Sea. This concentration was significantly higher than in bottom sediments collected in the same area, indicating an ice transport mechanism from an area with correspondingly higher concentrations. Recent results from the application of ice transport models and sediment analyses indicate that it is very likely that sediments are transported by ice, from the Siberian shelf areas to the Beaufort Sea

  6. Observed ices in the Solar System

    Science.gov (United States)

    Clark, Roger N.; Grundy, Will; Carlson, Robert R.; Noll, Keith; Gudipati, Murthy; Castillo-Rogez, Julie C.

    2013-01-01

    Ices have been detected and mapped on the Earth and all planets and/or their satellites further from the sun. Water ice is the most common frozen volatile observed and is also unambiguously detected or inferred in every planet and/or their moon(s) except Venus. Carbon dioxide is also extensively found in all systems beyond the Earth except Pluto although it sometimes appears to be trapped rather than as an ice on some objects. The largest deposits of carbon dioxide ice is on Mars. Sulfur dioxide ice is found in the Jupiter system. Nitrogen and methane ices are common beyond the Uranian system. Saturn’s moon Titan probably has the most complex active chemistry involving ices, with benzene (C6H6) and many tentative or inferred compounds including ices of Cyanoacetylene (HC3N), Toluene (C7H8), Cyanogen (C2N2), Acetonitrile (CH3CN), H2O, CO2, and NH3. Confirming compounds on Titan is hampered by its thick smoggy atmosphere. Ammonia was predicted on many icy moons but is notably absent among the definitively detected ices with the possible exception of Enceladus. Comets, storehouses of many compounds that could exist as ices in their nuclei, have only had small amounts of water ice definitively detected on their surfaces. Only one asteroid has had a direct detection of surface water ice, although its presence can be inferred in others. This chapter reviews some of the properties of ices that lead to their detection, and surveys the ices that have been observed on solid surfaces throughout the Solar System.

  7. EBSD in Antarctic and Greenland Ice

    Science.gov (United States)

    Weikusat, Ilka; Kuiper, Ernst-Jan; Pennock, Gill; Sepp, Kipfstuhl; Drury, Martyn

    2017-04-01

    Ice, particularly the extensive amounts found in the polar ice sheets, impacts directly on the global climate by changing the albedo and indirectly by supplying an enormous water reservoir that affects sea level change. The discharge of material into the oceans is partly controlled by the melt excess over snow accumulation, partly by the dynamic flow of ice. In addition to sliding over bedrock, an ice body deforms gravitationally under its own weight. In order to improve our description of this flow, ice microstructure studies are needed that elucidate the dominant deformation and recrystallization mechanisms involved. Deformation of hexagonal ice is highly anisotropic: ice is easily sheared in the basal plane and is about two orders of magnitude harder parallel to the c-axis. As dislocation creep is the dominant deformation mechanism in polar ice this strong anisotropy needs to be understood in terms of dislocation activity. The high anisotropy of the ice crystal is usually ascribed to a particular behaviour of dislocations in ice, namely the extension of dislocations into partials on the basal plane. Analysis of EBSD data can help our understanding of dislocation activity by characterizing subgrain boundary types thus providing a tool for comprehensive dislocation characterization in polar ice. Cryo-EBSD microstructure in combination with light microscopy measurements from ice core material from Antarctica (EPICA-DML deep ice core) and Greenland (NEEM deep ice core) are presented and interpreted regarding substructure identification and characterization. We examined one depth for each ice core (EDML: 656 m, NEEM: 719 m) to obtain the first comparison of slip system activity from the two ice sheets. The subgrain boundary to grain boundary threshold misorientation was taken to be 3-5° (Weikusat et al. 2011). EBSD analyses suggest that a large portion of edge dislocations with slip systems basal gliding on the basal plane were indeed involved in forming subgrain

  8. Arctic sea ice decline and ice export in the CMIP5 historical simulations

    Science.gov (United States)

    Langehaug, H. R.; Geyer, F.; Smedsrud, L. H.; Gao, Y.

    2013-11-01

    Arctic sea ice properties and Fram Strait ice export from six CMIP5 Global Climate and Earth System Models are evaluated and investigated for the period 1957-2005. Over the last decades most ensemble members simulate a decreasing September sea ice area and a slow, general thinning of the sea ice cover. While the different ensemble members both under- and overestimate the decline in observed September sea ice area, none of the members reproduce the observed thinning. This study is a first attempt to evaluate the Fram Strait ice area export in the CMIP5 models, and the role it has played for Arctic sea ice area and thickness. Five of the six models evaluated reproduce the seasonal cycle and the inter-annual variance of the ice area export in the Fram Strait reasonably well. The simulated southward export of sea ice in the Fram Strait constitutes a major fraction of the Arctic sea ice in these five models; 10-18% of the sea ice covered Arctic Basin is annually exported. For the same models the year-to-year variability in Fram Strait ice volume export carries 35% of the year-to-year variability in the Arctic Basin sea ice volume. We have found low but significant correlations on inter-annual timescales between the Fram Strait ice export, both in terms of area and volume, and the Arctic Basin sea ice thickness. All six models show that an increase in ice area export leads a decrease in the sea ice thickness. This inverse relationship also holds when considering the long-term trends; the larger the increase in Fram Strait ice area export, the larger the thinning of the Arctic Basin sea ice cover and the larger the loss in the September sea ice area. The different ensemble members show both negative and positive ice export trends. Focusing on the model with the largest number of ensemble members (10), we have been able to quantify the effect of the ice area export on the Arctic Basin sea ice for this particular model. For this model an increase of the ice area export

  9. Ice stratigraphy at the Pakitsoq ice margin, West Greenland, derived from gas records

    DEFF Research Database (Denmark)

    Schaefer, H.; Petrenko, V. V.; Brook, E. J.

    2009-01-01

    Horizontal ice-core sites, where ancient ice is exposed at the glacier surface, offer unique opportunities for paleo-studies of trace components requiring large sample volumes. Following previous work at the Pakitsoq ice margin in West Greenland, we use a combination of geochemical parameters...... measured in the ice matrix (delta O-18(ice)) and air occlusions (delta O-18(atm), delta N-15 of N-2 and methane concentration) to date ice layers from specific climatic intervals. The data presented here expand our understanding of the stratigraphy and three-dimensional structure of ice layers outcropping...... at Pakitsoq. Sections containing ice from every distinct climatic interval during Termination I, including Last Glacial Maximum, Bolling/Allerod, Younger Dryas and the early Holocene, are identified. In the early Holocene, we find evidence for climatic fluctuations similar to signals found in deep ice cores...

  10. Sea ice and pollution-modulated changes in Greenland ice core methanesulfonate and bromine

    Science.gov (United States)

    Maselli, Olivia J.; Chellman, Nathan J.; Grieman, Mackenzie; Layman, Lawrence; McConnell, Joseph R.; Pasteris, Daniel; Rhodes, Rachael H.; Saltzman, Eric; Sigl, Michael

    2017-01-01

    Reconstruction of past changes in Arctic sea ice extent may be critical for understanding its future evolution. Methanesulfonate (MSA) and bromine concentrations preserved in ice cores have both been proposed as indicators of past sea ice conditions. In this study, two ice cores from central and north-eastern Greenland were analysed at sub-annual resolution for MSA (CH3SO3H) and bromine, covering the time period 1750-2010. We examine correlations between ice core MSA and the HadISST1 ICE sea ice dataset and consult back trajectories to infer the likely source regions. A strong correlation between the low-frequency MSA and bromine records during pre-industrial times indicates that both chemical species are likely linked to processes occurring on or near sea ice in the same source regions. The positive correlation between ice core MSA and bromine persists until the mid-20th century, when the acidity of Greenland ice begins to increase markedly due to increased fossil fuel emissions. After that time, MSA levels decrease as a result of declining sea ice extent but bromine levels increase. We consider several possible explanations and ultimately suggest that increased acidity, specifically nitric acid, of snow on sea ice stimulates the release of reactive Br from sea ice, resulting in increased transport and deposition on the Greenland ice sheet.

  11. The future of ice sheets and sea ice: between reversible retreat and unstoppable loss.

    Science.gov (United States)

    Notz, Dirk

    2009-12-08

    We discuss the existence of cryospheric "tipping points" in the Earth's climate system. Such critical thresholds have been suggested to exist for the disappearance of Arctic sea ice and the retreat of ice sheets: Once these ice masses have shrunk below an anticipated critical extent, the ice-albedo feedback might lead to the irreversible and unstoppable loss of the remaining ice. We here give an overview of our current understanding of such threshold behavior. By using conceptual arguments, we review the recent findings that such a tipping point probably does not exist for the loss of Arctic summer sea ice. Hence, in a cooler climate, sea ice could recover rapidly from the loss it has experienced in recent years. In addition, we discuss why this recent rapid retreat of Arctic summer sea ice might largely be a consequence of a slow shift in ice-thickness distribution, which will lead to strongly increased year-to-year variability of the Arctic summer sea-ice extent. This variability will render seasonal forecasts of the Arctic summer sea-ice extent increasingly difficult. We also discuss why, in contrast to Arctic summer sea ice, a tipping point is more likely to exist for the loss of the Greenland ice sheet and the West Antarctic ice sheet.

  12. Evidence for middle Eocene Arctic sea ice from diatoms and ice-rafted debris.

    Science.gov (United States)

    Stickley, Catherine E; St John, Kristen; Koç, Nalân; Jordan, Richard W; Passchier, Sandra; Pearce, Richard B; Kearns, Lance E

    2009-07-16

    Oceanic sediments from long cores drilled on the Lomonosov ridge, in the central Arctic, contain ice-rafted debris (IRD) back to the middle Eocene epoch, prompting recent suggestions that ice appeared in the Arctic about 46 million years (Myr) ago. However, because IRD can be transported by icebergs (derived from land-based ice) and also by sea ice, IRD records are restricted to providing a history of general ice-rafting only. It is critical to differentiate sea ice from glacial (land-based) ice as climate feedback mechanisms vary and global impacts differ between these systems: sea ice directly affects ocean-atmosphere exchanges, whereas land-based ice affects sea level and consequently ocean acidity. An earlier report assumed that sea ice was prevalent in the middle Eocene Arctic on the basis of IRD, and although somewhat preliminary supportive evidence exists, these data are neither comprehensive nor quantified. Here we show the presence of middle Eocene Arctic sea ice from an extraordinary abundance of a group of sea-ice-dependent fossil diatoms (Synedropsis spp.). Analysis of quartz grain textural characteristics further supports sea ice as the dominant transporter of IRD at this time. Together with new information on cosmopolitan diatoms and existing IRD records, our data strongly suggest a two-phase establishment of sea ice: initial episodic formation in marginal shelf areas approximately 47.5 Myr ago, followed approximately 0.5 Myr later by the onset of seasonally paced sea-ice formation in offshore areas of the central Arctic. Our data establish a 2-Myr record of sea ice, documenting the transition from a warm, ice-free environment to one dominated by winter sea ice at the start of the middle Eocene climatic cooling phase.

  13. Hydrogen ICE Vehicle Testing Activities

    Energy Technology Data Exchange (ETDEWEB)

    J. Francfort; D. Karner

    2006-04-01

    The Advanced Vehicle Testing Activity teamed with Electric Transportation Applications and Arizona Public Service to develop and monitor the operations of the APS Alternative Fuel (Hydrogen) Pilot Plant. The Pilot Plant provides 100% hydrogen, and hydrogen and compressed natural gas (H/CNG)-blended fuels for the evaluation of hydrogen and H/CNG internal combustion engine (ICE) vehicles in controlled and fleet testing environments. Since June 2002, twenty hydrogen and H/CNG vehicles have accumulated 300,000 test miles and 5,700 fueling events. The AVTA is part of the Department of Energy’s FreedomCAR and Vehicle Technologies Program. These testing activities are managed by the Idaho National Laboratory. This paper discusses the Pilot Plant design and monitoring, and hydrogen ICE vehicle testing methods and results.

  14. Grain boundary melting in ice

    OpenAIRE

    Thomson, E. S.; Hansen-Goos, Hendrik; Wilen, L. A.; Wettlaufer, J. S.

    2012-01-01

    We describe an optical scattering study of grain boundary premelting in water ice. Ubiquitous long ranged attractive polarization forces act to suppress grain boundary melting whereas repulsive forces originating in screened Coulomb interactions and classical colligative effects enhance it. The liquid enhancing effects can be manipulated by adding dopant ions to the system. For all measured grain boundaries this leads to increasing premelted film thickness with increasing electrolyte concentr...

  15. Population structure of ice-breeding seals.

    Science.gov (United States)

    Davis, Corey S; Stirling, Ian; Strobeck, Curtis; Coltman, David W

    2008-07-01

    The development of population genetic structure in ice-breeding seal species is likely to be shaped by a combination of breeding habitat and life-history characteristics. Species that return to breed on predictable fast-ice locations are more likely to exhibit natal fidelity than pack-ice-breeding species, which in turn facilitates the development of genetic differentiation between subpopulations. Other aspects of life history such as geographically distinct vocalizations, female gregariousness, and the potential for polygynous breeding may also facilitate population structure. Based on these factors, we predicted that fast-ice-breeding seal species (the Weddell and ringed seal) would show elevated genetic differentiation compared to pack-ice-breeding species (the leopard, Ross, crabeater and bearded seals). We tested this prediction using microsatellite analysis to examine population structure of these six ice-breeding species. Our results did not support this prediction. While none of the Antarctic pack-ice species showed statistically significant population structure, the bearded seal of the Arctic pack ice showed strong differentiation between subpopulations. Again in contrast, the fast-ice-breeding Weddell seal of the Antarctic showed clear evidence for genetic differentiation while the ringed seal, breeding in similar habitat in the Arctic, did not. These results suggest that the development of population structure in ice-breeding phocid seals is a more complex outcome of the interplay of phylogenetic and ecological factors than can be predicted on the basis of breeding substrate and life-history characteristics.

  16. Trend analysis of Arctic sea ice extent

    Science.gov (United States)

    Silva, M. E.; Barbosa, S. M.; Antunes, Luís; Rocha, Conceição

    2009-04-01

    The extent of Arctic sea ice is a fundamental parameter of Arctic climate variability. In the context of climate change, the area covered by ice in the Arctic is a particularly useful indicator of recent changes in the Arctic environment. Climate models are in near universal agreement that Arctic sea ice extent will decline through the 21st century as a consequence of global warming and many studies predict a ice free Arctic as soon as 2012. Time series of satellite passive microwave observations allow to assess the temporal changes in the extent of Arctic sea ice. Much of the analysis of the ice extent time series, as in most climate studies from observational data, have been focussed on the computation of deterministic linear trends by ordinary least squares. However, many different processes, including deterministic, unit root and long-range dependent processes can engender trend like features in a time series. Several parametric tests have been developed, mainly in econometrics, to discriminate between stationarity (no trend), deterministic trend and stochastic trends. Here, these tests are applied in the trend analysis of the sea ice extent time series available at National Snow and Ice Data Center. The parametric stationary tests, Augmented Dickey-Fuller (ADF), Phillips-Perron (PP) and the KPSS, do not support an overall deterministic trend in the time series of Arctic sea ice extent. Therefore, alternative parametrizations such as long-range dependence should be considered for characterising long-term Arctic sea ice variability.

  17. The role of ice stream dynamics in deglaciation

    Science.gov (United States)

    Robel, Alexander A.; Tziperman, Eli

    2016-08-01

    Since the mid-Pleistocene transition, deglaciation has occurred only after ice sheets have grown large while experiencing several precession and obliquity cycles, indicating that large ice sheets are more sensitive to Milankovitch forcing than small ice sheets are. Observations and model simulations suggest that the development of ice streams in the Laurentide Ice Sheet played an as yet unknown role in deglaciations. In this study, we propose a mechanism by which ice streams may enhance deglaciation and render large ice sheets more sensitive to Milankovitch forcing. We use an idealized configuration of the Parallel Ice Sheet Model that permits the formation of ice streams. When the ice sheet is large and ice streams are sufficiently developed, an upward shift in equilibrium line altitude, commensurate with Milankovitch forcing, results in rapid deglaciation, while the same shift applied to an ice sheet without fully formed ice streams results in continued ice sheet growth or slower deglaciation. Rapid deglaciation in ice sheets with significant streaming behavior is caused by ice stream acceleration and the attendant enhancement of calving and surface melting at low elevations. Ice stream acceleration is ultimately the result of steepening of the ice surface and increased driving stresses in ice stream onset zones, which come about due to the dependence of surface mass balance on elevation. These ice sheet simulations match the broad features of geomorphological observations and add ice stream dynamics that are missing from previous model studies of deglaciation.

  18. ICE-DIP kicks off

    CERN Multimedia

    CERN Bulletin

    2013-01-01

    Last month, Marie Curie Actions* added a new member to its ranks: ICE-DIP (the Intel-CERN European Doctorate Industrial Program). The programme held its kick-off meeting on 18-19 February in Leixlip near Dublin, Ireland, at Intel’s premises.   Building on CERN’s long-standing relationship with Intel in the CERN openlab project, ICE-DIP brings together CERN and industrial partners, Intel and Xena Networks, to train five Early Stage ICT Researchers. These researchers will be funded by the European Commission and granted a CERN Fellow contract while enrolled in the doctoral programmes at partner universities Dublin City University and National University of Ireland Maynooth. The researchers will go on extended secondments to Intel Labs Europe locations across Europe during their three-year training programme. The primary focus of the ICE-DIP researchers will be the development of techniques for acquiring and processing data that are relevant for the trigger a...

  19. Ice Nuclei Production in Volcanic Clouds

    Science.gov (United States)

    Few, A. A.

    2012-12-01

    The paper [Durant et al., 2008] includes a review of research on ice nucleation in explosive volcanic clouds in addition to reporting their own research on laboratory measurements focused on single-particle ice nucleation. Their research as well as the research they reviewed were concerned with the freezing of supercooled water drops (250 to 260 K) by volcanic ash particles acting as ice freezing nuclei. Among their conclusions are: Fine volcanic ash particles are very efficient ice freezing nuclei. Volcanic clouds likely contain fine ash concentrations 104 to 105 times greater than found in meteorological clouds. This overabundance of ice nuclei will produce a cloud with many small ice crystals that will not grow larger as they do in meteorological clouds because the cloud water content is widely distributed among the numerous small ice crystals. The small ice crystals have a small fall velocity, thus volcanic clouds are very stable. The small ice crystals are easily lofted into the stratosphere transporting water and adsorbed trace gasses. In this paper we examine the mechanism for the production of the small ice nuclei and develop a simple model for calculating the size of the ice nuclei based upon the distribution of magma around imbedded bubbles. We also have acquired a volcanic bomb that exhibits bubble remnants on its entire surface. The naturally occurring fragments from the volcanic bomb reveal a size distribution consistent with that predicted by the simple model. Durant, A. J., R. A. Shaw, W. I. Rose, Y. Mi, and G. G. J. Ernst (2008), Ice nucleation and overseeding of ice in volcanic clouds, J. Geophys. Res., 113, D09206, doi:10.1029/2007JD009064.

  20. Early Student Support to Investigate the Role of Sea Ice-Albedo Feedback in Sea Ice Predictions

    Science.gov (United States)

    2014-09-30

    Ice - Albedo Feedback in Sea Ice Predictions Cecilia M. Bitz Atmospheric Sciences MS351640 University of Washington Seattle, WA 98196-1640 phone...TERM GOALS The overarching goals of this project are to understand the role of sea ice - albedo feedback on sea ice predictability, to improve how...sea- ice albedo is modeled and how sea ice predictions are initialized, and then to evaluate how these improvements influence inherent sea ice

  1. On the Predictability of Sea Ice

    Science.gov (United States)

    Blanchard-Wrigglesworth, Edward

    We investigate the persistence and predictability of sea ice in numerical models and observations. We first use the 3rd generation Community Climate System Model (CCSM3) General Circulation Model (GCM) to investigate the inherent persistence of sea-ice area and thickness. We find that sea-ice area anomalies have a seasonal decay timescale, exhibiting an initial decorrelation similar to a first order auto-regressive (AR1, or red noise) process. Beyond this initial loss of memory, there is a re-emergence of memory at certain times of the year. There are two distinct modes of re-emergence in the model, one driven by the seasonal coupling of area and thickness anomalies in the summer, the other by the persistence of upper ocean temperature anomalies that originate from ice anomalies in the melt season and then influence ice anomalies in the growth season. Comparison with satellite observations where available indicate these processes appear in nature. We then use the 4th generation CCSM (CCSM4) to investigate the partition of Arctic sea-ice predictability into its initial-value and boundary forced components under present day forcing conditions. We find that initial-value predictability lasts for 1-2 years for sea-ice area, and 3-4 years for sea-ice volume. Forced predictability arises after just 4-5 years for both area and volume. Initial-value predictability of sea-ice area during the summer hinges on the coupling between thickness and area anomalies during that season. We find that the loss of initial-value predictability with time is not uniform --- there is a rapid loss of predictability of sea-ice volume during the late spring early summer associated with snow melt and albedo feedbacks. At the same time, loss of predictability is not uniform across different regions. Given the usefulness of ice thickness as a predictor of summer sea-ice area, we obtain a hindcast of September sea-ice area initializing the GCM on May 1with an estimate of observed sea-ice thickness

  2. Ice matters. Arctic and Antarctic under-ice communities linking sea ice with the pelagic food web

    OpenAIRE

    Flores, Hauke; van Franeker, Jan Andries; Lange, Benjamin; Siegel, Volker; Kruse, Svenja; Hunt, Brian; Pakhomov, E. A.

    2013-01-01

    In both Polar Regions, sea ice environments are undergoing rapid environmental change. Because sea ice constitutes an important habitat for numerous species, as well as an important carbon source during critical periods of the year, these changes impact significantly on ecosystem functioning, biodiversity, species distribution and population sizes, including commercially exploited fish stocks. Species dwelling at the ice-water interface (e.g. Antarctic krill and Arctic cod) play a key role in...

  3. Off-Ice Anaerobic Power Does Not Predict On-Ice Repeated Shift Performance in Hockey.

    Science.gov (United States)

    Peterson, Ben J; Fitzgerald, John S; Dietz, Calvin C; Ziegler, Kevin S; Baker, Sarah E; Snyder, Eric M

    2016-09-01

    Peterson, BJ, Fitzgerald, JS, Dietz, CC, Ziegler, KS, Baker, SE, and Snyder, EM. Off-ice anaerobic power does not predict on-ice repeated shift performance in hockey. J Strength Cond Res 30(9): 2375-2381, 2016-Anaerobic power is a significant predictor of acceleration and top speed in team sport athletes. Historically, these findings have been applied to ice hockey although recent research has brought their validity for this sport into question. As ice hockey emphasizes the ability to repeatedly produce power, single bout anaerobic power tests should be examined to determine their ability to predict on-ice performance. We tested whether conventional off-ice anaerobic power tests could predict on-ice acceleration, top speed, and repeated shift performance. Forty-five hockey players, aged 18-24 years, completed anthropometric, off-ice, and on-ice tests. Anthropometric and off-ice testing included height, weight, body composition, vertical jump, and Wingate tests. On-ice testing consisted of acceleration, top speed, and repeated shift fatigue tests. Vertical jump (VJ) (r = -0.42; r = -0.58), Wingate relative peak power (WRPP) (r = -0.32; r = -0.43), and relative mean power (WRMP) (r = -0.34; r = -0.48) were significantly correlated (p ≤ 0.05) to on-ice acceleration and top speed, respectively. Conversely, none of the off-ice tests correlated with on-ice repeated shift performance, as measured by first gate, second gate, or total course fatigue; VJ (r = 0.06; r = 0.13; r = 0.09), WRPP (r = 0.06; r = 0.14; r = 0.10), or WRMP (r = -0.10; r = -0.01; r = -0.01). Although conventional off-ice anaerobic power tests predict single bout on-ice acceleration and top speed, they neither predict the repeated shift ability of the player, nor are good markers for performance in ice hockey.

  4. Caterpillar-like ice motion in the ablation zone of the Greenland ice sheet

    Science.gov (United States)

    Ryser, C.; Lüthi, M. P.; Andrews, L. C.; Catania, G. A.; Funk, M.; Hawley, R.; Hoffman, M.; Neumann, T. A.

    2014-10-01

    Current understanding of ice dynamics predicts that increasing availability and variability of meltwater will have an impact on basal motion and therefore on the evolution and future behavior of the Greenland ice sheet. We present measurements of ice deformation, subglacial water pressure, and surface velocity that show periodic and episodic variations on several time scales (seasonal, multiday, and diurnal). These variations, observed with GPS and sensors at different depths throughout the ice column, are not synchronous but show delayed responses of ice deformation with increasing depth and basal water pressure in antiphase with surface velocity. With the help of a Full-Stokes ice flow model, these observations are explained as ice motion in a caterpillar-like fashion. Caused by patches of different basal slipperiness, horizontal stress transfer through the stiff central part of the ice body leads to spatially varying surface velocities and ice deformation patterns. Variation of this basal slipperiness induces characteristic patterns of ice deformation variability that explain the observed behavior. Ice flow in the ablation zone of the Greenland ice sheet is therefore controlled by activation of basal patches by varying slipperiness in the course of a melt season, leading to caterpillar-like ice motion superposed on the classical shear deformation.

  5. CO2 (dry ice) cleaning system

    Science.gov (United States)

    Barnett, Donald M.

    1995-01-01

    Tomco Equipment Company has participated in the dry ice (solid carbon dioxide, CO2) cleaning industry for over ten years as a pioneer in the manufacturer of high density, dry ice cleaning pellet production equipment. For over four years Tomco high density pelletizers have been available to the dry ice cleaning industry. Approximately one year ago Tomco introduced the DI-250, a new dry ice blast unit making Tomco a single source supplier for sublimable media, particle blast, cleaning systems. This new blast unit is an all pneumatic, single discharge hose device. It meters the insertion of 1/8 inch diameter (or smaller), high density, dry ice pellets into a high pressure, propellant gas stream. The dry ice and propellant streams are controlled and mixed from the blast cabinet. From there the mixture is transported to the nozzle where the pellets are accelerated to an appropriate blasting velocity. When directed to impact upon a target area, these dry ice pellets have sufficient energy to effectively remove most surface coatings through dry, abrasive contact. The meta-stable, dry ice pellets used for CO2 cleaning, while labeled 'high density,' are less dense than alternate, abrasive, particle blast media. In addition, after contacting the target surface, they return to their equilibrium condition: a superheated gas state. Most currently used grit blasting media are silicon dioxide based, which possess a sharp tetrahedral molecular structure. Silicon dioxide crystal structures will always produce smaller sharp-edged replicas of the original crystal upon fracture. Larger, softer dry ice pellets do not share the same sharp-edged crystalline structures as their non-sublimable counterparts when broken. In fact, upon contact with the target surface, dry ice pellets will plastically deform and break apart. As such, dry ice cleaning is less harmful to sensitive substrates, workers and the environment than chemical or abrasive cleaning systems. Dry ice cleaning system

  6. Duality of Ross Ice Shelf systems: crustal boundary, ice sheet processes and ocean circulation from ROSETTA-Ice surveys

    Science.gov (United States)

    Tinto, K. J.; Siddoway, C. S.; Padman, L.; Fricker, H. A.; Das, I.; Porter, D. F.; Springer, S. R.; Siegfried, M. R.; Caratori Tontini, F.; Bell, R. E.

    2017-12-01

    Bathymetry beneath Antarctic ice shelves controls sub-ice-shelf ocean circulation and has a major influence on the stability and dynamics of the ice sheets. Beneath the Ross Ice Shelf, the sea-floor bathymetry is a product of both tectonics and glacial processes, and is influenced by the processes it controls. New aerogeophysical surveys have revealed a fundamental crustal boundary bisecting the Ross Ice Shelf and imparting a duality to the Ross Ice Shelf systems, encompassing bathymetry, ocean circulation and ice flow history. The ROSETTA-Ice surveys were designed to increase the resolution of Ross Ice Shelf mapping from the 55 km RIGGS survey of the 1970s to a 10 km survey grid, flown over three years from New York Air National Guard LC130s. Radar, LiDAR, gravity and magnetic instruments provide a top to bottom profile of the ice shelf and the underlying seafloor, with 20 km resolution achieved in the first two survey seasons (2015 and 2016). ALAMO ocean-profiling floats deployed in the 2016 season are measuring the temperature and salinity of water entering and exiting the sub-ice water cavity. A significant east-west contrast in the character of the magnetic and gravity fields reveals that the lithospheric boundary between East and West Antarctica exists not at the base of the Transantarctic Mountains (TAM), as previously thought, but 300 km further east. The newly-identified boundary spatially coincides with the southward extension of the Central High, a rib of shallow basement identified in the Ross Sea. The East Antarctic side is characterized by lower amplitude magnetic anomalies and denser TAM-type lithosphere compared to the West Antarctic side. The crustal structure imparts a fundamental duality on the overlying ice and ocean, with deeper bathymetry and thinner ice on the East Antarctic side creating a larger sub-ice cavity for ocean circulation. The West Antarctic side has a shallower seabed, more restricted ocean access and a more complex history of

  7. Understanding Ice Shelf Basal Melting Using Convergent ICEPOD Data Sets: ROSETTA-Ice Study of Ross Ice Shelf

    Science.gov (United States)

    Bell, R. E.; Frearson, N.; Tinto, K. J.; Das, I.; Fricker, H. A.; Siddoway, C. S.; Padman, L.

    2017-12-01

    The future stability of the ice shelves surrounding Antarctica will be susceptible to increases in both surface and basal melt as the atmosphere and ocean warm. The ROSETTA-Ice program is targeted at using the ICEPOD airborne technology to produce new constraints on Ross Ice Shelf, the underlying ocean, bathymetry, and geologic setting, using radar sounding, gravimetry and laser altimetry. This convergent approach to studying the ice-shelf and basal processes enables us to develop an understanding of the fundamental controls on ice-shelf evolution. This work leverages the stratigraphy of the ice shelf, which is detected as individual reflectors by the shallow-ice radar and is often associated with surface scour, form close to the grounding line or pinning points on the ice shelf. Surface accumulation on the ice shelf buries these reflectors as the ice flows towards the calving front. This distinctive stratigraphy can be traced across the ice shelf for the major East Antarctic outlet glaciers and West Antarctic ice streams. Changes in the ice thickness below these reflectors are a result of strain and basal melting and freezing. Correcting the estimated thickness changes for strain using RIGGS strain measurements, we can develop decadal-resolution flowline distributions of basal melt. Close to East Antarctica elevated melt-rates (>1 m/yr) are found 60-100 km from the calving front. On the West Antarctic side high melt rates primarily develop within 10 km of the calving front. The East Antarctic side of Ross Ice Shelf is dominated by melt driven by saline water masses that develop in Ross Sea polynyas, while the melting on the West Antarctic side next to Hayes Bank is associated with modified Continental Deep Water transported along the continental shelf. The two sides of Ross Ice Shelf experience differing basal melt in part due to the duality in the underlying geologic structure: the East Antarctic side consists of relatively dense crust, with low amplitude

  8. A simulated Antarctic fast ice ecosystem

    Science.gov (United States)

    Arrigo, Kevin R.; Kremer, James N.; Sullivan, Cornelius W.

    1993-01-01

    A 2D numerical ecosystem model of Antarctic land fast ice is developed to elucidate the primary production with the Antarctic sea ice zone. The physical component employs atmospheric data to simulate congelation ice growth, initial brine entrapment, desalination, and nutrient flux. The biological component is based on the concept of a maximum temperature-dependent algal growth rate which is reduced by limitations imposed from insufficient light or nutrients, as well as suboptimal salinity. Preliminary simulations indicate that, during a bloom, microalgae are able to maintain their vertical position relative to the lower congelation ice margin and are not incorporated into the crystal matrix as the ice sheet thickens. It is inferred that land fast sea ice contains numerous microhabitats that are functionally distinct based upon the unique set of processes that control microalgal growth and accumulation within each.

  9. Recent State of Arctic Sea Ice

    Science.gov (United States)

    Nghiem, S. V.; Rigor, I. G.; Clemente-Colón, P.; Perovich, D. K.; Richter-Menge, J. A.; Chao, Y.; Neumann, G.; Ortmeyer, M.

    2008-12-01

    We present the recent state of Arctic sea ice including observations from 2008 in a context of a multi-decadal perspective. A new record has been set in the reduction of Arctic perennial sea ice extent this winter. As of 1 March 2008, the extent of perennial sea ice was reduced by one million km2 compared to that at the same time last year as observed by the NASA SeaWinds scatterometer on the QuikSCAT satellite (QSCAT). This decrease of perennial ice continues the precipitous declining trend observed in this decade. Furthermore, the perennial sea ice pattern change was deduced by buoy-based estimates with 50 years of data from drifting buoys and measurement camps to track sea ice movement around the Arctic Ocean. The combination of the satellite and surface data records confirms that the reduction of winter perennial ice extent broke the record in 2008 compared to data over the last half century. In the winter, the loss of perennial ice extent was driven by winds that compressed the ice and transported it out of the Fram Strait and Nares Strait to warmer ocean waters at lower latitudes, where the ice melted very effectively. Another historical fact is that the boundary of perennial sea ice already crossed the North Pole (NP) in February 2008, leaving the area around the NP occupied by seasonal sea ice. This is the first time, not only from the satellite data record but also in the history of sea ice charting at the National Ice Center since the 1970's, that observations indicate the seasonal ice migration into the NP area so early in winter. In the Bering Sea by 12 March 2008, the sea ice edge reached to an extent that coincided with the continental shelf break, indicating bathymetric effects on the distribution of water masses along the Aleutian North Slope, Bering Slope, Anadyr, and Kamchatka Currents that governed the pattern of sea ice formation in this region. Moreover, QSCAT observations showed that, in the 2008 winter, seasonal ice occupied the Northern Sea

  10. MODIS Snow and Sea Ice Products

    Science.gov (United States)

    Hall, Dorothy K.; Riggs, George A.; Salomonson, Vincent V.

    2004-01-01

    In this chapter, we describe the suite of Earth Observing System (EOS) Moderate-Resolution Imaging Spectroradiometer (MODIS) Terra and Aqua snow and sea ice products. Global, daily products, developed at Goddard Space Flight Center, are archived and distributed through the National Snow and Ice Data Center at various resolutions and on different grids useful for different communities Snow products include binary snow cover, snow albedo, and in the near future, fraction of snow in a 5OO-m pixel. Sea ice products include ice extent determined with two different algorithms, and sea ice surface temperature. The algorithms used to develop these products are described. Both the snow and sea ice products, available since February 24,2000, are useful for modelers. Validation of the products is also discussed.

  11. Seismic explosion sources on an ice cap

    DEFF Research Database (Denmark)

    Shulgin, Alexey; Thybo, Hans

    2015-01-01

    Controlled source seismic investigation of crustal structure below ice covers is an emerging technique. We have recently conducted an explosive refraction/wide-angle reflection seismic experiment on the ice cap in east-central Greenland. The data-quality is high for all shot points and a full...... as a strong ice wave. The ice cap leads to low transmission of energy into the crust such that charges need be larger than in conventional onshore experiments to obtain reliable seismic signals. The strong reflection coefficient at the base of the ice generates strong multiples which may mask for secondary...... phases. This effect may be crucial for acquisition of reflection seismic profiles on ice caps. Our experience shows that it is essential to use optimum depth for the charges and to seal the boreholes carefully....

  12. IceProd 2 Usage Experience

    Science.gov (United States)

    Delventhal, D.; Schultz, D.; Diaz Velez, J. C.

    2017-10-01

    IceProd is a data processing and management framework developed by the IceCube Neutrino Observatory for processing of Monte Carlo simulations, detector data, and data driven analysis. It runs as a separate layer on top of grid and batch systems. This is accomplished by a set of daemons which process job workflow, maintaining configuration and status information on the job before, during, and after processing. IceProd can also manage complex workflow DAGs across distributed computing grids in order to optimize usage of resources. IceProd has recently been rewritten to increase its scaling capabilities, handle user analysis workflows together with simulation production, and facilitate the integration with 3rd party scheduling tools. IceProd 2, the second generation of IceProd, has been running in production for several months now. We share our experience setting up the system and things we’ve learned along the way.

  13. Improving Arctic sea ice edge forecasts by assimilating high horizontal resolution sea ice concentration data into the US Navy's ice forecast systems

    Science.gov (United States)

    Posey, P. G.; Metzger, E. J.; Wallcraft, A. J.; Hebert, D. A.; Allard, R. A.; Smedstad, O. M.; Phelps, M. W.; Fetterer, F.; Stewart, J. S.; Meier, W. N.; Helfrich, S. R.

    2015-08-01

    This study presents the improvement in ice edge error within the US Navy's operational sea ice forecast systems gained by assimilating high horizontal resolution satellite-derived ice concentration products. Since the late 1980's, the ice forecast systems have assimilated near real-time sea ice concentration derived from the Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave/Imager (SSMI and then SSMIS). The resolution of the satellite-derived product was approximately the same as the previous operational ice forecast system (25 km). As the sea ice forecast model resolution increased over time, the need for higher horizontal resolution observational data grew. In 2013, a new Navy sea ice forecast system (Arctic Cap Nowcast/Forecast System - ACNFS) went into operations with a horizontal resolution of ~ 3.5 km at the North Pole. A method of blending ice concentration observations from the Advanced Microwave Scanning Radiometer (AMSR2) along with a sea ice mask produced by the National Ice Center (NIC) has been developed, resulting in an ice concentration product with very high spatial resolution. In this study, ACNFS was initialized with this newly developed high resolution blended ice concentration product. The daily ice edge locations from model hindcast simulations were compared against independent observed ice edge locations. ACNFS initialized using the high resolution blended ice concentration data product decreased predicted ice edge location error compared to the operational system that only assimilated SSMIS data. A second evaluation assimilating the new blended sea ice concentration product into the pre-operational Navy Global Ocean Forecast System 3.1 also showed a substantial improvement in ice edge location over a system using the SSMIS sea ice concentration product alone. This paper describes the technique used to create the blended sea ice concentration product and the significant improvements in ice edge forecasting in both of the

  14. Design of an airborne P-band ice sounding radar

    DEFF Research Database (Denmark)

    Dall, Jørgen; Skou, Niels; Kusk, Anders

    2006-01-01

    is to test new ice sounding techniques, e.g. polarimetry, synthetic aperture processing, and coherent clutter suppression. A system analysis involving ice scattering models confirms that it is feasible to detect the bedrock through 4 km of ice and to detect deep ice layers. The ice sounder design features...

  15. Ice Motion and Topography Near Margin Areas of Kamb Ice Stream, Antarctica, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes ice motion and topography measurements that were taken by measuring movement and altitude of poles set in the West Antarctic Ice Shelf. The...

  16. National Ice Center Arctic Sea Ice Charts and Climatologies in Gridded Format

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. National Ice Center (NIC) is an inter-agency sea ice analysis and forecasting center comprised of the Department of Commerce/NOAA, the Department of...

  17. Cook Inlet and Kenai Peninsula, Alaska ESI: ICE (Ice Extent Lines)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains locations of ice extent in Cook Inlet, Alaska. Vector lines in the data set represent 50 percent ice coverage. Location-specific type and...

  18. Multiple Isotope Analysis of Sulfate in the West Antarctic Ice Sheet Divide Ice Core, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains measurements of multiple sulfur and oxygen isotopes from sulfates, from an ice core drilled at the West Antarctic Ice Sheet (WAIS) Divide site...

  19. IceBridge Radar L3 Tomographic Ice Thickness V001

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains Level-3 tomographic ice thickness measurements derived from data captured by the Center for Remote Sensing of Ice Sheets (CReSIS) Multichannel...

  20. Arctic sea ice decline contributes to thinning lake ice trend in northern Alaska

    Science.gov (United States)

    Alexeev, Vladimir; Arp, Christopher D.; Jones, Benjamin M.; Cai, Lei

    2016-01-01

    Field measurements, satellite observations, and models document a thinning trend in seasonal Arctic lake ice growth, causing a shift from bedfast to floating ice conditions. September sea ice concentrations in the Arctic Ocean since 1991 correlate well (r = +0.69,p Research and Forecasting model output produced a 7% decrease in lake ice growth when 2007/08 sea ice was imposed on 1991/92 climatology and a 9% increase in lake ice growth for the opposing experiment. Here, we clearly link early winter 'ocean-effect' snowfall and warming to reduced lake ice growth. Future reductions in sea ice extent will alter hydrological, biogeochemical, and habitat functioning of Arctic lakes and cause sub-lake permafrost thaw.

  1. National Ice Center Arctic Sea Ice Charts and Climatologies in Gridded Format, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — The U.S. National Ice Center (NIC) is an inter-agency sea ice analysis and forecasting center comprised of the Department of Commerce/NOAA, the Department of...

  2. Ice Draft and Ice Velocity Data in the Beaufort Sea, 1990-2003, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides measurement of sea ice draft (m) and the movement of sea ice (cm/s) over the continental shelf of the Eastern Beaufort Sea. The data set spans...

  3. The ecophysiology of under-ice fauna

    OpenAIRE

    Aarset, Arne V.

    1991-01-01

    During exposure to low salinity, the under-ice amphipods Gammarus wilkitzkii and Onisimus glacialis appeared as euryhaline osmoregulators, displaying regulation of haemolymph concentrations of sodium and chloride. Free amino acids took part in the regulation. During freezing and brine formation, the amphipods were freeze-sensitive and did not tolerate being frozen into solid ice. However, they could stay in the vicinity of the ice, conforming osmotically to the ambient brine and thus lowering...

  4. On the origin of the ice ages

    OpenAIRE

    Oerlemans, J.

    1984-01-01

    Ice sheet dynamics provide a possible explanation for the 100 kyr power in climatic records. Some numerical experiments presented here show that even the transition from an essentially ice-free earth to a glacial can be produced by a northern hemisphere ice-sheet model, provided that a slow general cooling on the northern hemisphere continents is imposed. Such a cooling could for example be the result of continental drift.

  5. Biological darkening of ice: measurements and models

    Science.gov (United States)

    Cook, J.; Tedstone, A.; Hodson, A. J.; Williamson, C.; McCutcheon, J.; Tranter, M.

    2017-12-01

    Biological growth occurs in the ablation zones of glaciers and ice sheets, resulting in a reduction of the ice albedo. Given the critical role of albedo in determining the surface energy balance - and therefore melt rate - of a mass of ice, understanding and quantifying biological albedo reduction is fundamental to predicting future ice dynamics. This may be particularly important on ablating ice on the western Greenland Ice Sheet, where a `dark ice zone' of varying spatial extent may be partly or mostly explained by biological growth. However, our ability to quantify and predict the contribution of biological impurities to the overall energy balance of glacial systems is currently limited by a lack of understanding of the mechanisms of biological darkening, difficulties in determining the spatial extent of biological impurities and uncertainty in isolating biological from non-biological albedo reduction. Here, new spectral measurements are presented for ice containing varying amounts of biological impurities which were obtained on the ground using a field spectrometer and from the air using a purpose built UAV on the Greenland Ice Sheet in summer 2016 and 2017. Distinctive spectral signatures are identified and used to map the spatial extent of algal blooms on the ice surface. A new radiative transfer scheme (BioSNICAR) for predicting the albedo of snow or ice discolored by microbial life is also described, offering insight into the mechanisms of biological darkening. Together, these demonstrate the critical role played by pigmented algae in darkening ice surfaces and provide a framework for predicting biological albedo reduction in future climate scenarios.

  6. Boundary layer physics over snow and ice

    OpenAIRE

    Anderson, P. S.; Neff, W. D.

    2008-01-01

    Observations of the unique chemical environment over snow and ice in recent decades, particularly in the polar regions, have stimulated increasing interest in the boundary layer processes that mediate exchanges between the ice/snow interface and the atmosphere. This paper provides a review of the underlying concepts and examples from recent field studies in polar boundary layer meteorology, which will generally apply to atmospheric flow over snow and ice surfaces. It forms a companion paper t...

  7. Ice storms in a changing climate

    OpenAIRE

    McNitt, Jennifer M.

    2016-01-01

    Approved for public release; distribution is unlimited Ice storms can cause billions of dollars' worth of damage to energy infrastructure, towers, surrounding trees (that could further damage electrical structures), and transportation, and can cause deaths--either due to exposure to subfreezing temperatures or vehicular accidents. An increase in global temperatures, due to climate change, could affect the frequency, intensity, and geographic location of ice storms. Three known ice storm ca...

  8. 21 CFR 880.6050 - Ice bag.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ice bag. 880.6050 Section 880.6050 Food and Drugs....6050 Ice bag. (a) Identification. An ice bag is a device intended for medical purposes that is in the... the body. The device may include a holder that keeps the bag in place against an external area of the...

  9. Elevator deflections on the icing process

    Science.gov (United States)

    Britton, Randall K.

    1990-01-01

    The effect of elevator deflection of the horizontal stabilizer for certain icing parameters is investigated. Elevator deflection can severely change the lower and upper leading-edge impingement limits, and ice can accrete on the elevator itself. Also, elevator deflection had practically no effect on the maximum local collection efficiency. It is shown that for severe icing conditions (large water droplets), elevator deflections that increase the projected height of the airfoil can significantly increase the total collection efficiency of the airfoil.

  10. Swimming Three Ice Miles within Fifteen Hours.

    Science.gov (United States)

    Stjepanovic, Mirko; Nikolaidis, Pantelis T.; Knechtle, Beat

    2017-08-31

    Ice Mile swimming (1608 m in water of below 5 °Celsius) is becoming increasingly popular. This case study aimed to identify body core temperature and selected haematological and biochemical parameters before and after repeated Ice Miles. An experienced ice swimmer completed three consecutive Ice Miles within 15 h. Swim times, body core temperatures, and selected urinary and haematological parameters were recorded. Body core temperature reached its maximum between 5, 8 and 15 min after immersion (37.7°C, 38.1°C, and 38.0°C, respectively). The swimmer suffered hypothermia during the first Ice Mile (35.4°C) and body core temperature dropped furthermore to 34.5°C during recovery after the first Ice Mile. He developed a metabolic acidosis in both the first and the last Ice Mile (pH 7.31 and pH 7.34, respectively). We observed hyperkalaemia ([K⁺] > 5.5 mM) after the second Ice Mile (6.9 mM). This was followed by a drop in [K⁺] to3.7 mM after the third Ice Mile. Anticipatory thermogenesis (i.e. an initial increase of body core temperature after immersion in ice cold water) seems to be a physiological response in a trained athlete. The results suggest that swimming in ice-cold water leads to a metabolic acidosis, which the swimmer compensates with hyperventilation (i.e. leading to respiratory alkalosis). The shift of serum [K⁺] could increase the risk of a cardiac arrhythmia. Further studies addressing the physiology and potential risks of Ice Mile swimming are required to substantiate this finding.

  11. Greenland Ice Shelves and Ice Tongues

    DEFF Research Database (Denmark)

    Reeh, Niels

    2017-01-01

    literature and physical properties are reviewed. There exists a difference between: (1) Floating glaciers in northern Greenland (>77°N) which experience bottom melting as their dominant ablation mechanism and calve relatively thin, but large (km-sized) tabular icebergs (‘ice islands’), and (2) Grounded...... glaciers further south (iceberg calving provides the dominant ablation mechanism. The relatively smaller iceberg discharge in northern Greenland is closely related to the occurrence of extended floating glacier sections, allowing bottom melting estimated at up to 10 m year−1 for locations...

  12. Icing Branch Current Research Activities in Icing Physics

    Science.gov (United States)

    Vargas, Mario

    2009-01-01

    Current development: A grid block transformation scheme which allows the input of grids in arbitrary reference frames, the use of mirror planes, and grids with relative velocities has been developed. A simple ice crystal and sand particle bouncing scheme has been included. Added an SLD splashing model based on that developed by William Wright for the LEWICE 3.2.2 software. A new area based collection efficiency algorithm will be incorporated which calculates trajectories from inflow block boundaries to outflow block boundaries. This method will be used for calculating and passing collection efficiency data between blade rows for turbo-machinery calculations.

  13. Coupled regional climate-ice-sheet simulation shows limited Greenland ice loss during the Eemian

    OpenAIRE

    Helsen, M. M.; van de Berg, W. J.; van de Wal, R. S. W.; van den Broeke, M. R.; Oerlemans, J.

    2013-01-01

    During the last interglacial period (Eemian, 130–115 kyr BP) eustatic global sea level likely peaked at > 6 m above the present-day level, but estimates of the contribution of the Greenland Ice Sheet vary widely. Here we use an asynchronously two-way-coupled regional climate–ice-sheet model, which includes physically realistic feedbacks between the changing ice sheet topography and climate forcing. Our simulation results in a contribution from the Greenland Ice Sheet to the ...

  14. Windows in Arctic sea ice: Light transmission and ice algae in a refrozen lead

    Science.gov (United States)

    Kauko, Hanna M.; Taskjelle, Torbjørn; Assmy, Philipp; Pavlov, Alexey K.; Mundy, C. J.; Duarte, Pedro; Fernández-Méndez, Mar; Olsen, Lasse M.; Hudson, Stephen R.; Johnsen, Geir; Elliott, Ashley; Wang, Feiyue; Granskog, Mats A.

    2017-06-01

    The Arctic Ocean is rapidly changing from thicker multiyear to thinner first-year ice cover, with significant consequences for radiative transfer through the ice pack and light availability for algal growth. A thinner, more dynamic ice cover will possibly result in more frequent leads, covered by newly formed ice with little snow cover. We studied a refrozen lead (≤0.27 m ice) in drifting pack ice north of Svalbard (80.5-81.8°N) in May-June 2015 during the Norwegian young sea ICE expedition (N-ICE2015). We measured downwelling incident and ice-transmitted spectral irradiance, and colored dissolved organic matter (CDOM), particle absorption, ultraviolet (UV)-protecting mycosporine-like amino acids (MAAs), and chlorophyll a (Chl a) in melted sea ice samples. We found occasionally very high MAA concentrations (up to 39 mg m-3, mean 4.5 ± 7.8 mg m-3) and MAA to Chl a ratios (up to 6.3, mean 1.2 ± 1.3). Disagreement in modeled and observed transmittance in the UV range let us conclude that MAA signatures in CDOM absorption spectra may be artifacts due to osmotic shock during ice melting. Although observed PAR (photosynthetically active radiation) transmittance through the thin ice was significantly higher than that of the adjacent thicker ice with deep snow cover, ice algal standing stocks were low (≤2.31 mg Chl a m-2) and similar to the adjacent ice. Ice algal accumulation in the lead was possibly delayed by the low inoculum and the time needed for photoacclimation to the high-light environment. However, leads are important for phytoplankton growth by acting like windows into the water column.

  15. Possible Mechanisms for Turbofan Engine Ice Crystal Icing at High Altitude

    Science.gov (United States)

    Tsao, Jen-Ching; Struk, Peter M.; Oliver, Michael J.

    2016-01-01

    A thermodynamic model is presented to describe possible mechanisms of ice formation on unheated surfaces inside a turbofan engine compression system from fully glaciated ice crystal clouds often formed at high altitude near deep convective weather systems. It is shown from the analysis that generally there could be two distinct types of ice formation: (1) when the "surface freezing fraction" is in the range of 0 to 1, dominated by the freezing of water melt from fully or partially melted ice crystals, the ice structure is formed from accretion with strong adhesion to the surface, and (2) when the "surface melting fraction" is the range of 0 to 1, dominated by the further melting of ice crystals, the ice structure is formed from accumulation of un-melted ice crystals with relatively weak bonding to the surface. The model captures important qualitative trends of the fundamental ice-crystal icing phenomenon reported earlier (Refs. 1 and 2) from the research collaboration work by NASA and the National Research Council (NRC) of Canada. Further, preliminary analysis of test data from the 2013 full scale turbofan engine ice crystal icing test (Ref. 3) conducted in the NASA Glenn Propulsion Systems Laboratory (PSL) has also suggested that (1) both types of ice formation occurred during the test, and (2) the model has captured some important qualitative trend of turning on (or off) the ice crystal ice formation process in the tested engine low pressure compressor (LPC) targeted area under different icing conditions that ultimately would lead to (or suppress) an engine core roll back (RB) event.

  16. Ice, Ocean and Atmosphere Interactions in the Arctic Marginal Ice Zone

    Science.gov (United States)

    2015-09-30

    release; distribution is unlimited. DRI TECHNICAL PROGRAM: Emerging Dynamics Of The Marginal Ice Zone Ice, Ocean and Atmosphere Interactions in the...Arctic Marginal Ice Zone Year 4 Annual Report Jeremy Wilkinson British Antarctic Survey phone: 44 (0)1223 221489 fax: 44 (0) 1223...sams.ac.uk LONG-TERM GOALS This DRI TECHNICAL PROGRAM (Emerging Dynamics Of The Marginal Ice Zone) brings together a high-level

  17. Sea ice roughness: the key for predicting Arctic summer ice albedo

    Science.gov (United States)

    Landy, J.; Ehn, J. K.; Tsamados, M.; Stroeve, J.; Barber, D. G.

    2017-12-01

    Although melt ponds on Arctic sea ice evolve in stages, ice with smoother surface topography typically allows the pond water to spread over a wider area, reducing the ice-albedo and accelerating further melt. Building on this theory, we simulated the distribution of meltwater on a range of statistically-derived topographies to develop a quantitative relationship between premelt sea ice surface roughness and summer ice albedo. Our method, previously applied to ICESat observations of the end-of-winter sea ice roughness, could account for 85% of the variance in AVHRR observations of the summer ice-albedo [Landy et al., 2015]. Consequently, an Arctic-wide reduction in sea ice roughness over the ICESat operational period (from 2003 to 2008) explained a drop in ice-albedo that resulted in a 16% increase in solar heat input to the sea ice cover. Here we will review this work and present new research linking pre-melt sea ice surface roughness observations from Cryosat-2 to summer sea ice albedo over the past six years, examining the potential of winter roughness as a significant new source of sea ice predictability. We will further evaluate the possibility for high-resolution (kilometre-scale) forecasts of summer sea ice albedo from waveform-level Cryosat-2 roughness data in the landfast sea ice zone of the Canadian Arctic. Landy, J. C., J. K. Ehn, and D. G. Barber (2015), Albedo feedback enhanced by smoother Arctic sea ice, Geophys. Res. Lett., 42, 10,714-10,720, doi:10.1002/2015GL066712.

  18. Diversity of cultured bacteria from the perennial ice block of Scarisoara Ice Cave, Romania

    Directory of Open Access Journals (Sweden)

    Corina Iţcuş

    2016-01-01

    Full Text Available Cave ice ecosystems represent a poorly investigated glacial environment. Diversity of cave ice bacteria and their distribution in perennial ice deposits of this underground glacial habitat could constitute a proxy for microbial response to climatic and environmental changes. Scarisoara Ice Cave (Romania hosts one of the oldest and largest cave ice blocks worldwide. Here we report on cultured microbial diversity of recent, 400, and 900 years-old perennial ice from this cave, representing the first characterization of a chronological distribution of cave-ice bacteria. Total cell density measured by SYBR Green I epifluorescence microscopy varied in the 2.4 x 104 – 2.9 x 105 cells mL-1 range. The abundance of cultured bacteria (5 x 102 – 8 x 104 CFU mL-1 representing 0.3-52% of the total cell number decreased exponentially with the ice age, and was higher in organic rich ice sediments. Cultivation at 4˚C and 15˚C using BIOLOG EcoPlates revealed a higher functional diversity of cold-active bacteria, dependent on the age, sediment content and physicochemical properties of the ice. The composition dissimilarity of ice microbiota across the ice block was confirmed by growth parameter variations when cultivated in different liquid media at low and high temperatures. PCR-DGGE and sequencing of bacterial 16S rRNA gene fragments from the cultured ice samples led to the identification of 77 bacterial amplicons belonging to Gammaproteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria, showing variation in distribution across the ice layers. Several identified OTUs were homologous to those identified in other glacial and karst environments and showed partial conservation across the ice block. Moreover, our survey provided a glimpse on the cave-ice hosted bacteria as putative biomarkers for past climate and environmental changes.

  19. Determining the ice seasons severity during 1982-2015 using the ice extents sum as a new characteristic

    Science.gov (United States)

    Rjazin, Jevgeni; Pärn, Ove

    2016-04-01

    Sea ice is a key climate factor and it restricts considerably the winter navigation in sever seasons on the Baltic Sea. So determining ice conditions severity and describing ice cover behaviour at severe seasons interests scientists, engineers and navigation managers. The present study is carried out to determine the ice seasons severity degree basing on the ice seasons 1982 to 2015. A new integrative characteristic is introduced to describe the ice season severity. It is the sum of ice extents of the ice season id est the daily ice extents of the season are summed. The commonly used procedure to determine the ice season severity degree by the maximal ice extent is in this research compared to the new characteristic values. The remote sensing data on the ice concentrations on the Baltic Sea published in the European Copernicus Programme are used to obtain the severity characteristic values. The ice extents are calculated on these ice concentration data. Both the maximal ice extent of the season and a newly introduced characteristic - the ice extents sum are used to classify the winters with respect of severity. The most severe winter of the reviewed period is 1986/87. Also the ice seasons 1981/82, 1984/85, 1985/86, 1995/96 and 2002/03 are classified as severe. Only three seasons of this list are severe by both the criteria. They are 1984/85, 1985/86 and 1986/87. We interpret this coincidence as the evidence of enough-during extensive ice cover in these three seasons. In several winters, for example 2010/11 ice cover extended enough for some time, but did not endure. At few other ice seasons as 2002/03 the Baltic Sea was ice-covered in moderate extent, but the ice cover stayed long time. At 11 winters the ice extents sum differed considerably (> 10%) from the maximal ice extent. These winters yield one third of the studied ice seasons. The maximal ice extent of the season is simple to use and enables to reconstruct the ice cover history and to predict maximal ice

  20. Modeling interfacial liquid layers on environmental ices

    Directory of Open Access Journals (Sweden)

    M. H. Kuo

    2011-09-01

    Full Text Available Interfacial layers on ice significantly influence air-ice chemical interactions. In solute-containing aqueous systems, a liquid brine may form upon freezing due to the exclusion of impurities from the ice crystal lattice coupled with freezing point depression in the concentrated brine. The brine may be segregated to the air-ice interface where it creates a surface layer, in micropockets, or at grain boundaries or triple junctions.

    We present a model for brines and their associated liquid layers in environmental ice systems that is valid over a wide range of temperatures and solute concentrations. The model is derived from fundamental equlibrium thermodynamics and takes into account nonideal solution behavior in the brine, partitioning of the solute into the ice matrix, and equilibration between the brine and the gas phase for volatile solutes. We find that these phenomena are important to consider when modeling brines in environmental ices, especially at low temperatures. We demonstrate its application for environmentally important volatile and nonvolatile solutes including NaCl, HCl, and HNO3. The model is compared to existing models and experimental data from literature where available. We also identify environmentally relevant regimes where brine is not predicted to exist, but the QLL may significantly impact air-ice chemical interactions. This model can be used to improve the representation of air-ice chemical interactions in polar atmospheric chemistry models.

  1. Dynamics of colloidal particles in ice

    KAUST Repository

    Spannuth, Melissa

    2011-01-01

    We use x-ray photon correlation spectroscopy (XPCS) to probe the dynamics of colloidal particles in polycrystalline ice. During freezing, the dendritic ice morphology and rejection of particles from the ice created regions of high particle density, where some of the colloids were forced into contact and formed disordered aggregates. The particles in these high density regions underwent ballistic motion, with a characteristic velocity that increased with temperature. This ballistic motion is coupled with both stretched and compressed exponential decays of the intensity autocorrelation function. We suggest that this behavior could result from ice grain boundary migration. © 2011 American Institute of Physics.

  2. Polar Ice Sounding and Geomagnetics, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — Data addresses ice thickness and related geomagnetics generated during remote sensing flights over Antarctica and Greenland. Analog records are oscilloscope traces...

  3. Yield surface evolution for columnar ice

    Directory of Open Access Journals (Sweden)

    Zhiwei Zhou

    Full Text Available A series of triaxial compression tests, which has capable of measuring the volumetric strain of the sample, were conducted on columnar ice. A new testing approach of probing the experimental yield surface was performed from a single sample in order to investigate yield and hardening behaviors of the columnar ice under complex stress states. Based on the characteristic of the volumetric strain, a new method of defined the multiaxial yield strengths of the columnar ice is proposed. The experimental yield surface remains elliptical shape in the stress space of effective stress versus mean stress. The effect of temperature, loading rate and loading path in the initial yield surface and deformation properties of the columnar ice were also studied. Subsequent yield surfaces of the columnar ice have been explored by using uniaxial and hydrostatic paths. The evolution of the subsequent yield surface exhibits significant path-dependent characteristics. The multiaxial hardening law of the columnar ice was established experimentally. A phenomenological yield criterion was presented for multiaxial yield and hardening behaviors of the columnar ice. The comparisons between the theoretical and measured results indicate that this current model is capable of giving a reasonable prediction for the multiaxial yield and post-yield properties of the columnar ice subjected to different temperature, loading rate and path conditions. Keywords: Columnar ice, Multiaxial loading, Hardening rule, Path dependency, Yield criterion

  4. Allan Hills Pleistocene Ice Project (PIP)

    Science.gov (United States)

    Kurbatov, A.; Brook, E.; Campbell, S. W.; Conway, H.; Dunbar, N. W.; Higgins, J. A.; Iverson, N. A.; Kehrl, L. M.; McIntosh, W. C.; Spaulding, N. E.; Yan, Y.; Mayewski, P. A.

    2016-12-01

    A major international effort to identify at least 1.5 Ma old ice for paleoclimate reconstructions has successfully resulted in the selection of several potential drill sites in East Antarctica. At this point it is indisputable that the Antarctic ice sheet captures a continuous envinronmental record of the Earth that spans the Mid Pleistocene Transition (MPT). In addition to traditional ice coring approaches, the oldest ice can also be recovered in Antarctic Blue Ice Areas (BIA). We have already successfully demonstrated that the Allan Hills (AH) BIA captures a regional climate signal and robust record of 1Ma atmosphere that can be studied with a relatively uncomplicated logistical imprint and essentially unlimited sampling volume. The attractiveness of unlimited sampling of known age ice is the basis for the "ice park" concept proposed earlier by our research team. The idea is that, once the age of ice exposed along the flow line at the surface of BIA is mapped, it could be sampled for numerous research projects as needed. Here we propose an intermediate ( 1,150 m deep) ice core drill site, located only 240 km away from McMurdo base that will help to develop a, continuous, high quality regional paleoclimate record that is at least 1Ma old. We will introduce and discuss the glaciological settings, paleoclimate signals and possible limitations and advantages of the 1 Ma AH BIA regional paleoclimate record. The research was funded by NSF Division of Polar Programs.

  5. RIDES: Raman Icing Detection System, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Michigan Aerospace Corporation proposes to develop an integrated LIDAR instrument capable of identifying icing conditions while also providing air data sensing...

  6. [Reflectance of sea ice in Liaodong Bay].

    Science.gov (United States)

    Xu, Zhan-tang; Yang, Yue-zhong; Wang, Gui-fen; Cao, Wen-xi; Kong, Xiang-peng

    2010-07-01

    In the present study, the relationships between sea ice albedo and the bidirectional reflectance distribution in Liaodong Bay were investigated. The results indicate that: (1) sea ice albedo alpha(lambda) is closely related to the components of sea ice, the higher the particulate concentration in sea ice surface is, the lower the sea ice albedo alpha(lambda) is. On the contrary, the higher the bubble concentration in sea ice is, the higher sea ice albedo alpha(lambda) is. (2) Sea ice albedo alpha(lambda) is similar to the bidirectional reflectance factor R(f) when the probe locates at nadir. The R(f) would increase with the increase in detector zenith theta, and the correlation between R(f) and the detector azimuth would gradually increase. When the theta is located at solar zenith 63 degrees, the R(f) would reach the maximum, and the strongest correlation is also shown between the R(f) and the detector azimuth. (3) Different types of sea ice would have the different anisotropic reflectance factors.

  7. The IceCube Computing Infrastructure Model

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    Besides the big LHC experiments a number of mid-size experiments is coming online which need to define new computing models to meet the demands on processing and storage requirements of those experiments. We present the hybrid computing model of IceCube which leverages GRID models with a more flexible direct user model as an example of a possible solution. In IceCube a central datacenter at UW-Madison servers as Tier-0 with a single Tier-1 datacenter at DESY Zeuthen. We describe the setup of the IceCube computing infrastructure and report on our experience in successfully provisioning the IceCube computing needs.

  8. Viscosity of interfacial water regulates ice nucleation

    International Nuclear Information System (INIS)

    Li, Kaiyong; Chen, Jing; Zhang, Qiaolan; Zhang, Yifan; Xu, Shun; Zhou, Xin; Cui, Dapeng; Wang, Jianjun; Song, Yanlin

    2014-01-01

    Ice formation on solid surfaces is an important phenomenon in many fields, such as cloud formation and atmospheric icing, and a key factor for applications in preventing freezing. Here, we report temperature-dependent nucleation rates of ice for hydrophilic and hydrophobic surfaces. The results show that hydrophilic surface presents a lower ice nucleation rate. We develop a strategy to extract the thermodynamic parameters, J 0 and Γ, in the context of classical nucleation theory. From the extracted J 0 and Γ, we reveal the dominant role played by interfacial water. The results provide an insight into freezing mechanism on solid surfaces

  9. Linking scales in sea ice mechanics

    Science.gov (United States)

    Weiss, Jérôme; Dansereau, Véronique

    2017-02-01

    Mechanics plays a key role in the evolution of the sea ice cover through its control on drift, on momentum and thermal energy exchanges between the polar oceans and the atmosphere along cracks and faults, and on ice thickness distribution through opening and ridging processes. At the local scale, a significant variability of the mechanical strength is associated with the microstructural heterogeneity of saline ice, however characterized by a small correlation length, below the ice thickness scale. Conversely, the sea ice mechanical fields (velocity, strain and stress) are characterized by long-ranged (more than 1000 km) and long-lasting (approx. few months) correlations. The associated space and time scaling laws are the signature of the brittle character of sea ice mechanics, with deformation resulting from a multi-scale accumulation of episodic fracturing and faulting events. To translate the short-range-correlated disorder on strength into long-range-correlated mechanical fields, several key ingredients are identified: long-ranged elastic interactions, slow driving conditions, a slow viscous-like relaxation of elastic stresses and a restoring/healing mechanism. These ingredients constrained the development of a new continuum mechanics modelling framework for the sea ice cover, called Maxwell-elasto-brittle. Idealized simulations without advection demonstrate that this rheological framework reproduces the main characteristics of sea ice mechanics, including anisotropy, spatial localization and intermittency, as well as the associated scaling laws. This article is part of the themed issue 'Microdynamics of ice'.

  10. Partially ordered state of ice XV

    Science.gov (United States)

    Komatsu, K.; Noritake, F.; Machida, S.; Sano-Furukawa, A.; Hattori, T.; Yamane, R.; Kagi, H.

    2016-01-01

    Most ice polymorphs have order–disorder “pairs” in terms of hydrogen positions, which contributes to the rich variety of ice polymorphs; in fact, three recently discovered polymorphs— ices XIII, XIV, and XV—are ordered counter forms to already identified disordered phases. Despite the considerable effort to understand order–disorder transition in ice crystals, there is an inconsistency among the various experiments and calculations for ice XV, the ordered counter form of ice VI, i.e., neutron diffraction observations suggest antiferroelectrically ordered structures, which disagree with dielectric measurement and theoretical studies, implying ferroelectrically ordered structures. Here we investigate in-situ neutron diffraction measurements and density functional theory calculations to revisit the structure and stability of ice XV. We find that none of the completely ordered configurations are particular favored; instead, partially ordered states are established as a mixture of ordered domains in disordered ice VI. This scenario in which several kinds of ordered configuration coexist dispels the contradictions in previous studies. It means that the order–disorder pairs in ice polymorphs are not one-to-one correspondent pairs but rather have one-to-n correspondence, where there are n possible configurations at finite temperature. PMID:27375120

  11. Communication: Hypothetical ultralow-density ice polymorphs

    Science.gov (United States)

    Matsui, Takahiro; Hirata, Masanori; Yagasaki, Takuma; Matsumoto, Masakazu; Tanaka, Hideki

    2017-09-01

    More than 300 kinds of porous ice structures derived from zeolite frameworks and space fullerenes are examined using classical molecular dynamics simulations. It is found that a hypothetical zeolitic ice phase is less dense and more stable than the sparse ice structures reported by Huang et al. [Chem. Phys. Lett. 671, 186 (2017)]. In association with the zeolitic ice structure, even less dense structures, "aeroices," are proposed. It is found that aeroices are the most stable solid phases of water near the absolute zero temperature under negative pressure.

  12. Can Thermal Bending Fracture Ice Shelves?

    Science.gov (United States)

    MacAyeal, D. R.; Sergienko, O. V.; Banwell, A. F.; Willis, I.; Macdonald, G. J.; Lin, J.

    2017-12-01

    Visco-elastic plates will bend if the temperature on one side is cooled. If the plate is constrained to float, as for sea ice floes, this bending will lead to tensile stresses that can fracture the ice. The hydroacoustic regime below sea ice displays increased fracture-sourced noise when air temperatures above the ice cools with the diurnal cycle. The McMurdo Ice Shelf, Antarctica, also displays a massive increase in seismicity during the cooling phase of the diurnal cycle, and this motivates the question: Can surface cooling (or other forcing with thermal consequences) drive through-thickness fracture leading to iceberg calving? Past study of this question for sea ice gives an upper limit of ice-plate thickness (order meters) for which diurnal-scale thermal bending fracture can occur; but could cooling with longer time scales induce fracture of thicker ice plates? Given the seismic evidence of thermal bending fracture on the McMurdo Ice Shelf, the authors examine this question further.

  13. Bibliography of Ice Properties and Forecasting Related to Transportation in Ice-Covered Waters.

    Science.gov (United States)

    1980-09-01

    between duced. the above-water and underwater portions of an ice pressure ridge. Seasonal and spatial data from two Parmenter, Frances C., Spring ice...Glaciology and ice conditions in the Alaska, is mainly a series of braided channels that Weddell Sea, Servicio de Hydrografia Naval, Boetin freeze

  14. Deformation and failure of the ice bridge on the Wilkins Ice Shelf, Antarctica

    NARCIS (Netherlands)

    Humbert, A.; Gross, D.; Müller, R.; Braun, M.; van de Wal, R.S.W.; van den Broeke, M.R.; Vaughan, D.G.; van de Berg, W.J.

    2010-01-01

    A narrow bridge of floating ice that connected the Wilkins Ice Shelf, Antarctica, to two confining islands eventually collapsed in early April 2009. In the month preceding the collapse, we observed deformation of the ice bridge by means of satellite imagery and from an in situ GPS station.

  15. Bridge ice accretion and de- and anti-icing systems: A review

    DEFF Research Database (Denmark)

    Kleissl, Kenneth; Georgakis, Christos

    2010-01-01

    in turn lead to severe financial losses. This paper presents a review of the different de- and anti-icing techniques, already developed or in development, which could be applied to bridge cables or pylons. Furthermore, the fundamentals of icing caused by freezing precipitation and in-cloud icing...

  16. Inhibition of ice crystal growth in ice cream mix by gelatin hydrolysate.

    Science.gov (United States)

    Damodaran, Srinivasan

    2007-12-26

    The inhibition of ice crystal growth in ice cream mix by gelatin hydrolysate produced by papain action was studied. The ice crystal growth was monitored by thermal cycling between -14 and -12 degrees C at a rate of one cycle per 3 min. It is shown that the hydrolysate fraction containing peptides in the molecular weight range of about 2000-5000 Da exhibited the highest inhibitory activity on ice crystal growth in ice cream mix, whereas fractions containing peptides greater than 7000 Da did not inhibit ice crystal growth. The size distribution of gelatin peptides formed in the hydrolysate was influenced by the pH of hydrolysis. The optimum hydrolysis conditions for producing peptides with maximum ice crystal growth inhibitory activity was pH 7 at 37 degrees C for 10 min at a papain to gelatin ratio of 1:100. However, this may depend on the type and source of gelatin. The possible mechanism of ice crystal growth inhibition by peptides from gelatin is discussed. Molecular modeling of model gelatin peptides revealed that they form an oxygen triad plane at the C-terminus with oxygen-oxygen distances similar to those found in ice nuclei. Binding of this oxygen triad plane to the prism face of ice nuclei via hydrogen bonding appears to be the mechanism by which gelatin hydrolysate might be inhibiting ice crystal growth in ice cream mix.

  17. Do pelagic grazers benefit from sea ice? Insights from the Antarctic sea ice proxy IPSO25

    Science.gov (United States)

    Schmidt, Katrin; Brown, Thomas A.; Belt, Simon T.; Ireland, Louise C.; Taylor, Kyle W. R.; Thorpe, Sally E.; Ward, Peter; Atkinson, Angus

    2018-04-01

    Sea ice affects primary production in polar regions in multiple ways. It can dampen water column productivity by reducing light or nutrient supply, provide a habitat for ice algae and condition the marginal ice zone (MIZ) for phytoplankton blooms on its seasonal retreat. The relative importance of three different carbon sources (sea ice derived, sea ice conditioned, non-sea-ice associated) for the polar food web is not well understood, partly due to the lack of methods that enable their unambiguous distinction. Here we analysed two highly branched isoprenoid (HBI) biomarkers to trace sea-ice-derived and sea-ice-conditioned carbon in Antarctic krill (Euphausia superba) and relate their concentrations to the grazers' body reserves, growth and recruitment. During our sampling in January-February 2003, the proxy for sea ice diatoms (a di-unsaturated HBI termed IPSO25, δ13C = -12.5 ± 3.3 ‰) occurred in open waters of the western Scotia Sea, where seasonal ice retreat was slow. In suspended matter from surface waters, IPSO25 was present at a few stations close to the ice edge, but in krill the marker was widespread. Even at stations that had been ice-free for several weeks, IPSO25 was found in krill stomachs, suggesting that they gathered the ice-derived algae from below the upper mixed layer. Peak abundances of the proxy for MIZ diatoms (a tri-unsaturated HBI termed HBI III, δ13C = -42.2 ± 2.4 ‰) occurred in regions of fast sea ice retreat and persistent salinity-driven stratification in the eastern Scotia Sea. Krill sampled in the area defined by the ice edge bloom likewise contained high amounts of HBI III. As indicators for the grazer's performance we used the mass-length ratio, size of digestive gland and growth rate for krill, and recruitment for the biomass-dominant calanoid copepods Calanoides acutus and Calanus propinquus. These indices consistently point to blooms in the MIZ as an important feeding ground for pelagic grazers. Even though ice

  18. Results from IceCube

    Directory of Open Access Journals (Sweden)

    DeYoung Tyce

    2016-01-01

    Full Text Available Data from the IceCube Neutrino Observatory have revealed the existence of a flux of high energy neutrinos of extraterrestrial origin, which is observed in a number of analyses spanning different energy ranges, fields of view, and neutrino flavors. The current data are consistent with an isotropic, equal-flavor flux described by a simple power law spectrum, but deviations from this simple model cannot yet be constrained with high precision. The existing observations in this area are reviewed, along with recent results on dark matter searches and observations of cosmic rays.

  19. IceCube and ANTARES

    Directory of Open Access Journals (Sweden)

    Brunner Jürgen

    2013-06-01

    Full Text Available IceCube and ANTARES are neutrino detectors sensitive to energies from 20 GeV up to PeV. Both detectors have been completed and take data. Several years of data have been already analysed including periods with the partly assembled detectors. The primary goal of these two neutrino telescopes is the observation of astrophysical sources of neutrinos. Results from searches for such neutrinos with different strategies will be presented as well as measurements of atmospheric neutrinos which are an irreducible background for such searches, but they are an interesting study object by themselves.

  20. Ice Nuclei from Birch Trees

    Science.gov (United States)

    Felgitsch, Laura; Seifried, Teresa; Winkler, Philipp; Schmale, David, III; Grothe, Hinrich

    2017-04-01

    While the importance of heterogeneous ice nucleation in the atmosphere is known, we still know very little about the substances triggering these freezing events. Recent findings support the theory that biological ice nuclei (IN) exhibit the ability to play an important role in these processes. Huffman et al. (2013) showed a burst of biological IN over woodlands triggered by rain events. Birch pollen are known to release a high number of efficient IN if incubated in water (Pummer et al. 2012). Therefore birches are of interest in our research on this topic. Plants native to the timberline, such as birch trees, have to cope with very cold climatic conditions, rendering freezing avoidance impossible. These plants trigger freezing in their extracellular spaces to control the freezing process and avoid intracellular freezing, which would have lethal consequences. The plants hereby try to freeze at a temperature well above homogeneous freezing temperatures but still at temperatures low enough to not be effected by brief night frosts. To achieve this, IN are an important tool. The specific objective of our work was to study the potential sources and distribution of IN in birch trees. We collected leaves, fruit, bark, and trunk cores from a series of mature birch trees in Tyrol, Austria at different altitudes and sampling sites. We also collected samples from a birch tree in an urban park in Vienna, Austria. Our data show a sampling site dependence and the distribution of IN throughout the tree. Our data suggest that leaves, bark, and wood of birch can function as a source of IN, which are easily extracted with water. The IN are therefore not restricted to pollen. Hence, the amount of IN, which can be released from birch trees, is tremendous and has been underrated so far. Future work aims to elucidate the nature, contribution, and potential ecological roles of IN from birch trees in different habitats. Huffman, J.A., Prenni, A.J., DeMott, P.J., Pöhlker, C., Mason, R