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Sample records for change material integrated

  1. Micro-encapsulated phase-change materials integrated into construction materials

    Energy Technology Data Exchange (ETDEWEB)

    Schossig, P.; Henning, H.-M.; Gschwander, S. [Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstr. 2, 79110 Freiburg (Germany); Haussmann, T. [PSE GmbH-Forschung, Entwicklung, Marketing Solar Info Center, 79072 Freiburg (Germany)

    2005-11-15

    The idea of improving the thermal comfort of lightweight buildings by integrating phase-change materials (PCMs) into the building structure has been investigated in various research projects over several decades. Most of these attempts applied macro-capsules or direct immersion processes, which both turned out to present several drawbacks. Due to these problems, none of these PCM products was successful in the wider market. The new option to micro-encapsulate PCMs, a key technology which overcomes many of these problems, may make PCM products accessible for the building industry. This paper describes the work done at Fraunhofer ISE within a German government-funded project over the last 5 years, extending from building simulations to first measurements of full-size rooms equipped with PCM. The first products are now available on the market. (author) [Phase change material; Passive cooling; Energy efficient building; Microencapsulation].

  2. Thermal Vacuum Test of Ice as a Phase Change Material Integrated with a Radiator

    Science.gov (United States)

    Lee, Steve A.; Leimkuehler, Thomas O.; Stephan, Ryan; Le, Hung V.

    2010-01-01

    Water may be used as radiation shielding for Solar Particle Events (SPE) to protect crewmembers in the Lunar Electric Rover (LER). Because the water is already present for radiation protection, it could also provide a mass efficient solution to the vehicle's thermal control system. This water can be frozen by heat rejection from a radiator and used as a Phase Change Material (PC1V1) for thermal storage. Use of this water as a PCM can eliminate the need for a pumped fluid loop thermal control system as well as reduce the required size of the radiator. This paper describes the testing and analysis performed for the Rover Engineering Development Unit (REDU), a scaled-down version of a water PCM heat sink for the LER. The REDU was tested in a thermal-vacuum chamber at environmental temperatures similar to those of a horizontal radiator panel on the lunar surface. Testing included complete freeze and melt cycles along with scaled transient heat load profiles simulating a 24-hour day for the rover.

  3. Nanoscale phase change memory materials.

    Science.gov (United States)

    Caldwell, Marissa A; Jeyasingh, Rakesh Gnana David; Wong, H-S Philip; Milliron, Delia J

    2012-08-01

    Phase change memory materials store information through their reversible transitions between crystalline and amorphous states. For typical metal chalcogenide compounds, their phase transition properties directly impact critical memory characteristics and the manipulation of these is a major focus in the field. Here, we discuss recent work that explores the tuning of such properties by scaling the materials to nanoscale dimensions, including fabrication and synthetic strategies used to produce nanoscale phase change memory materials. The trends that emerge are relevant to understanding how such memory technologies will function as they scale to ever smaller dimensions and also suggest new approaches to designing materials for phase change applications. Finally, the challenges and opportunities raised by integrating nanoscale phase change materials into switching devices are discussed.

  4. Heat Storage Performance of the Prefabricated Hollow Core Concrete Deck Element with Integrated Microencapsulated Phase Change Material

    DEFF Research Database (Denmark)

    Pomianowski, Michal Zbigniew; Heiselberg, Per; Jensen, Rasmus Lund

    2012-01-01

    of thermal properties of standard concrete material and pure PCM. Consequently, the numerical models of the decks were updated with the experimentally determined thermal properties of PCM concrete after these two materials have been combined into one material. Finally, the heat storage of the decks......The paper presents the numerically calculated dynamic heat storage capacity of the prefabricated hollow core concrete deck element with and without microencapsulated phase change material (PCM). The reference deck is the ordinary deck made of standard concrete material and that is broadly used...... in many emerging buildings. The new concrete deck with microencapsulated PCM is the standard deck on which one more layer with PCM concrete was added and at the same time the latent heat storage was introduced to the construction. The challenge to simulate the performance of the new deck with PCM concrete...

  5. Effect of Phase Change Materials (PCMs Integrated into a Concrete Block on Heat Gain Prevention in a Hot Climate

    Directory of Open Access Journals (Sweden)

    Ahmad Hasan

    2016-10-01

    Full Text Available In the current study, a phase change material (PCM contained in an insulated concrete block is tested in extremely hot weather in the United Arab Emirates (UAE to evaluate its cooling performance. An insulated chamber is constructed behind the block containing PCM to mimic a scaled down indoor space. The effect of placement of the PCM layer on heat gain indoors is studied at two locations: adjacent to the outer as well as the inner concrete layer. The inclusion of PCM reduced heat gain through concrete blocks compared to blocks without PCM, yielding a drop in cooling load indoors. The placement of PCM and insulation layers adjacent to indoors exhibited better cooling performance compared to that adjacent to the outdoors. In the best case, a temperature drop of 8.5% and a time lag of 2.6 h are achieved in peak indoor temperature, rendering a reduction of 44% in the heat gain. In the tested hot climate, the higher ambient temperature and the lower wind speed hampered heat dissipation and PCM re-solidification by natural ventilation. The findings recommend employing a mechanical ventilation in hot climates to enhance regeneration of the PCM to solid state for its optimal performance.

  6. Development, Implementation, and Assessment of Climate Curricular Materials for Introductory Undergraduates: Lessons Learned from the InTeGrate Project's Climate of Change Module

    Science.gov (United States)

    Walker, B.; Fadem, C. M.; Shellito, L. J.

    2014-12-01

    Designing climate change curricular materials suitable for wide adoption across institutions and academic disciplines (including those outside of the geosciences) requires collaboration among faculty at different types of institutions and consideration of a variety of student populations, learning styles, and course formats. The Interdisciplinary Teaching of Geoscience for a Sustainable Future (InTeGrate) project, an NSF STEP Center program, provides opportunities for faculty to develop 2-3 week teaching modules to engage students in understanding the intersections between geoscience topics and societal issues. From 2012-2014, a team of 3 faculty from a liberal arts college, comprehensive university, and community college developed, implemented, assessed, and revised a 2-3 week module for introductory undergraduates entitled "Climate of change: interactions and feedbacks between water, air, and ice". The module uses authentic atmosphere, ocean, and cryosphere data from several regions to illustrate how climate impacts human societies and that the climate system has interacting components complicated by feedbacks, uncertainties, and human behavioral decisions. Students also consider past and present human adaptations to climate fluctuations. The module was piloted in introductory geology, meteorology, and oceanography courses during the 2012-2013 academic year, during which time formative and summative assessments were administered and used to modify the curricular materials. We will provide an overview of the module's content, instructional strategies involved in implementing the module, and methods of formative and summative assessment. We will also report on lessons learned during the development, piloting, revision, and publishing process, the importance of fostering partnerships between faculty from different institution types, and design approaches that promote widespread adoption of climate curricular materials.

  7. The Changing Materiality of Music

    DEFF Research Database (Denmark)

    Bødker, Henrik

    . Against the backdrop of recent discussions of popular music as material culture it is argued that emergent usages must be seen in relation to accumulations of different materialities and that such a perspective highlights issues related to both aesthetic reflexivity and agency. Keywords: cultural......A great deal of effort has gone into discussing issues of copyright in relation to the new materialities of the digital distribution of popular music; there has, however, been less focus on the changes that these new developments may invoke with respect to the cultural and social usages of music...... commodity, materiality, reflexivity, music, MP3...

  8. Transitional Phenomena on Phase Change Materials

    Directory of Open Access Journals (Sweden)

    Wójcik Tadeusz M.

    2014-03-01

    Full Text Available One of the most significant problem with technology development is transferring of large heat fluxes, which requires constant heat transfer temperature (in the specified temperature range. This problem concern mainly the nuclear energetics, space technologies, military technologies and most of all electronics containing integrated circuits with very large scale of integrations. Intensive heat transfer and thermal energy storage are possible by the use of phase change materials (PCMs. In the paper there are presented preliminary results of research on the use of liquid-gas (L-G PCMs and solid-solid phase change materials (S-S PCMs. For L-G PCMs the boiling characteristics were determined by increasing and decreasing the heat flux, which for certain sets of structural parameters of the heating surface and the physical properties of the liquid induce a variety of forms of transitional phenomena. Thermal energy storage is much more effective when using PCMs than sensible heat.

  9. Polymers in phase change materials

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, M.C.; Brites, M.J.; Alexandre, J.H. [National Lab. for Energy and Geology, Lisbon (Portugal)

    2010-07-01

    Phase Change Materials (PCMs) which are the core of latent heat thermal energy storage systems are currently an area of investigation of increasing interest. Several substances differing in physical and chemical characteristics as well as in thermal behavior have been studied as PCMS{sup 1-3}. In order to meet the requisites of particular systems, auxiliary materials are often used with specific functions. This bibliographic survey shows that polymeric materials have been proposed either as the PCM itself in solid-liquid or solid-solid transitions or to perform auxiliary functions of shape stabilisation and microencapsulation for solid-liquid PCMs. The PCMs have an operating temperature ranging from around 0 C (for the system water/polyacrilamid) to around 127 C (for crosslinked HDPE). (orig.)

  10. Materials and integration schemes for above-IC integrated optics

    NARCIS (Netherlands)

    Schmitz, Jurriaan; Rangarajan, Balaji; Kovalgin, Alexey Yu

    2014-01-01

    A study is presented on silicon oxynitride material for waveguides and germanium-silicon alloys for p-i-n diodes. The materials are manufactured at low, CMOS-backend compatible temperatures, targeting the integration of optical functions on top of CMOS chips. Low-temperature germanium-silicon deposi

  11. Material platforms for integrated quantum photonics

    CERN Document Server

    Bogdanov, Simeon; Boltasseva, Alexandra; Shalaev, Vladimir M

    2016-01-01

    On-chip integration of quantum optical systems could be a major factor enabling photonic quantum technologies. Unlike the case of electronics, where the essential device is a transistor and the dominant material is silicon, the toolbox of elementary devices required for both classical and quantum photonic integrated circuits is vast. Therefore, many material platforms are being examined to host the future quantum photonic computers and network nodes. We discuss the pros and cons of several platforms for realizing various elementary devices, compare the current degrees of integration achieved in each platform and review several composite platform approaches.

  12. Advanced materials for integrated optical waveguides

    CERN Document Server

    Tong Ph D, Xingcun Colin

    2014-01-01

    This book provides a comprehensive introduction to integrated optical waveguides for information technology and data communications. Integrated coverage ranges from advanced materials, fabrication, and characterization techniques to guidelines for design and simulation. A concluding chapter offers perspectives on likely future trends and challenges. The dramatic scaling down of feature sizes has driven exponential improvements in semiconductor productivity and performance in the past several decades. However, with the potential of gigascale integration, size reduction is approaching a physical limitation due to the negative impact on resistance and inductance of metal interconnects with current copper-trace based technology. Integrated optics provides a potentially lower-cost, higher performance alternative to electronics in optical communication systems. Optical interconnects, in which light can be generated, guided, modulated, amplified, and detected, can provide greater bandwidth, lower power consumption, ...

  13. Integrated modelling in materials and process technology

    DEFF Research Database (Denmark)

    Hattel, Jesper Henri

    2008-01-01

    processes from the viewpoint of combined materials and process modelling are presented: solidification of thin walled ductile cast iron, integrated modelling of spray forming and multiphysics modelling of friction stir welding. The fourth example describes integrated modelling applied to a failure analysis...... of premature rupture of a stellite weld on a P91 valve used in a power plant. For all four examples, the focus is put on modelling results rather than describing the models in detail. Proper comparison with experimental work is given in all examples for model validation as well as relevant references...

  14. PCM Concrete. [Phase Change Materials

    Energy Technology Data Exchange (ETDEWEB)

    Juul Andersen, T. [Danish Technological Institute, Taastrup (Denmark); Poulsen, H.-H. [BASF A/S, Roedekro (Denmark); Passov, F. [Spaencom A/S, Hedehusene (Denmark); Heiselberg, P. [Aalborg Univ..Aalborg (Denmark)

    2013-04-01

    PCM-Concrete was a research and development project launched in 2009 and finished in 2012. The project, which was funded by The Danish National Advanced Technology Foundation, had a total budget of 1.7 million Euros and included 4 partners: Danish Technological Institute (project manager), Aalborg University, BASF A/S and Spaencom A/S. The overall vision of the project was to reduce energy consumption for heating and cooling in buildings by developing high-performance concrete structures microencapsulated Phase Change Materials (PCM). The PCM used in the project was Micronal produced by BASF A/S. Micronal is small capsules with an acrylic shell and inside a wax with a melting point at approx. 23 deg. C equal to a comfortable indoor temperature. During the melting process thermal energy is transferred to chemical reaction (melting/solidification) depending on PCM being heated up or cooled down. Adding Micronal to concrete would theoretically increase the thermal mass of the concrete and improve the diurnal heat capacity which is the amount of energy that can be stored and released during 24 hours. Nevertheless, it is a relatively new technology that has not received much attention, yet. In the PCM-Concrete project 5 main investigations were carried out: 1) Development of concrete mix design with PCM. 2) Investigation of thermal properties of the PCM concrete: thermal conductivity, specific heat capacity, density. 3) Up-scaling the research to industrial production of PCM-concrete structures. 4) Testing energy efficiency in full scale. 5) Confronting aesthetic and acoustic barriers to full exploitation of the potential of PCM-concrete structures. The results from the test program showed: 1) That the diurnal heat storage capacity is higher for all 4 hollow core decks with tiles attached compared to the reference hollow core deck. 2) The hollow core decks with concrete tiles without PCM performs slightly better than the tiles with PCM. 3) That is was impossible to

  15. Active materials for integrated optic applications

    Science.gov (United States)

    Hayden, Joseph S.; Funk, David S.; Veasey, David L.; Peters, Philip M.; Sanford, Norman A.

    1999-11-01

    The ability to engineer glass properties through the selection and adjustment of chemical composition continues to make glass a leading material in both active and passive applications. The development of optimal glass compositions for integrated optical applications requires a number of considerations that are often at variance with one another. Of critical importance is that the glass offers compatibility with standard ion exchange technologies, allowing fabrication of guided wave structures. In addition, for application as an active material, the resultant structures must be characterized by absence of inclusions and low absorption at the lasing wavelength, putting demands on both the selection and identity of the raw materials used to prepare the glass. We report on the development of an optimized glass composition for integrated optic applications that combines good laser properties with good chemical durability allowing for a wide range of chemical processing steps to be employed without substrate deterioration. In addition, care was taken during the development of this glass to insure that the selected composition was consistent with manufacturing technology for producing high optical quality glass. We present the properties of the resultant glasses, including results of detailed chemical and laser properties, for use in the design and modeling of active waveguides prepared with these glasses.

  16. PHASE CHANGE MATERIALS IN FLOOR TILES FOR THERMAL ENERGY STORAGE

    Energy Technology Data Exchange (ETDEWEB)

    Douglas C. Hittle

    2002-10-01

    Passive solar systems integrated into residential structures significantly reduce heating energy consumption. Taking advantage of latent heat storage has further increased energy savings. This is accomplished by the incorporation of phase change materials into building materials used in passive applications. Trombe walls, ceilings and floors can all be enhanced with phase change materials. Increasing the thermal storage of floor tile by the addition of encapsulated paraffin wax is the proposed topic of research. Latent heat storage of a phase change material (PCM) is obtained during a change in phase. Typical materials use the latent heat released when the material changes from a liquid to a solid. Paraffin wax and salt hydrates are examples of such materials. Other PCMs that have been recently investigated undergo a phase transition from one solid form to another. During this process they will release heat. These are known as solid-state phase change materials. All have large latent heats, which makes them ideal for passive solar applications. Easy incorporation into various building materials is must for these materials. This proposal will address the advantages and disadvantages of using these materials in floor tile. Prototype tile will be made from a mixture of quartz, binder and phase change material. The thermal and structural properties of the prototype tiles will be tested fully. It is expected that with the addition of the phase change material the structural properties will be compromised to some extent. The ratio of phase change material in the tile will have to be varied to determine the best mixture to provide significant thermal storage, while maintaining structural properties that meet the industry standards for floor tile.

  17. Research on microcapsules of phase change materials

    Institute of Scientific and Technical Information of China (English)

    DAI Xia; SHEN Xiaodong

    2006-01-01

    Microcapsule technology is a kind of technology wrapping the solid or liquid into minute-sized particles within the field of micrometer or millimeter with film forming materials. This thesis introduces microcapsule technology of phase change materials and its main functions and the structural composition, preparation methods and characterization technology of microcapsule of phase change materials. The microcapsule of phase change materials is small in size and its temperature remains unchanged during the process of heat absorption and heat release. It is of great value in research and application prospect due to these characteristics.

  18. Integrated Charge Transfer in Organic Ferroelectrics for Flexible Multisensing Materials.

    Science.gov (United States)

    Xu, Beibei; Ren, Shenqiang

    2016-09-01

    The ultimate or end point of functional materials development is the realization of strong coupling between all energy regimes (optical, electronic, magnetic, and elastic), enabling the same material to be utilized for multifunctionalities. However, the integration of multifunctionalities in soft materials with the existence of various coupling is still in its early stage. Here, the coupling between ferroelectricity and charge transfer by combining bis(ethylenedithio)tetrathiafulvalene-C60 charge-transfer crystals with ferroelectric polyvinylidene fluoride polymer matrix is reported, which enables external stimuli-controlled polarization, optoelectronic and magnetic field sensing properties. Such flexible composite films also display a superior strain-dependent capacitance and resistance change with a giant piezoresistance coefficient of 7.89 × 10(-6) Pa(-1) . This mutual coupled material with the realization of enhanced couplings across these energy domains opens up the potential for multisensing applications.

  19. High Temperature Integrated Thermoelectric Ststem and Materials

    Energy Technology Data Exchange (ETDEWEB)

    Mike S. H. Chu

    2011-06-06

    The final goal of this project is to produce, by the end of Phase II, an all ceramic high temperature thermoelectric module. Such a module design integrates oxide ceramic n-type, oxide ceramic p-type materials as thermoelectric legs and oxide ceramic conductive material as metalizing connection between n-type and p-type legs. The benefits of this all ceramic module are that it can function at higher temperatures (> 700 C), it is mechanically and functionally more reliable and it can be scaled up to production at lower cost. With this all ceramic module, millions of dollars in savings or in new opportunities recovering waste heat from high temperature processes could be made available. A very attractive application will be to convert exhaust heat from a vehicle to reusable electric energy by a thermoelectric generator (TEG). Phase I activities were focused on evaluating potential n-type and p-type oxide compositions as the thermoelectric legs. More than 40 oxide ceramic powder compositions were made and studied in the laboratory. The compositions were divided into 6 groups representing different material systems. Basic ceramic properties and thermoelectric properties of discs sintered from these powders were measured. Powders with different particles sizes were made to evaluate the effects of particle size reduction on thermoelectric properties. Several powders were submitted to a leading thermoelectric company for complete thermoelectric evaluation. Initial evaluation showed that when samples were sintered by conventional method, they had reasonable values of Seebeck coefficient but very low values of electrical conductivity. Therefore, their power factors (PF) and figure of merits (ZT) were too low to be useful for high temperature thermoelectric applications. An unconventional sintering method, Spark Plasma Sintering (SPS) was determined to produce better thermoelectric properties. Particle size reduction of powders also was found to have some positive benefits

  20. Selective Integration in the Material-Point Method

    DEFF Research Database (Denmark)

    Andersen, Lars; Andersen, Søren; Damkilde, Lars

    2009-01-01

    The paper deals with stress integration in the material-point method. In order to avoid parasitic shear in bending, a formulation is proposed, based on selective integration in the background grid that is used to solve the governing equations. The suggested integration scheme is compared...... to a traditional material-point-method computation in which the stresses are evaluated at the material points. The deformation of a cantilever beam is analysed, assuming elastic or elastoplastic material behaviour....

  1. Interaction, Change, and Wholeness of Material Things

    CERN Document Server

    Semyonov, Oleg G

    2007-01-01

    Interaction is the mode of being of material things amid other material things an the driving force of change and wholeness. Through mutual influence, changes of interacting things become interdependent and their properties interrelated, which leads to formation of ensembles - material wholes of correlated things, where the mode of being of a particular component depends on the modes of being of all other components and vice versa. Every ensemble attains its wholeness and becomes a physical body through togetherness of interrelated components coexisting as a collective being with mutually restrained internal motion. Properties of ensembles on all structural levels of matter composition emerge through the collective being of components.

  2. Integration of advanced nuclear materials separation processes

    Energy Technology Data Exchange (ETDEWEB)

    Jarvinen, G.D.; Worl, L.A.; Padilla, D.D.; Berg, J.M.; Neu, M.P.; Reilly, S.D.; Buelow, S.

    1998-12-31

    This is the final report of a two-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). This project has examined the fundamental chemistry of plutonium that affects the integration of hydrothermal technology into nuclear materials processing operations. Chemical reactions in high temperature water allow new avenues for waste treatment and radionuclide separation.Successful implementation of hydrothermal technology offers the potential to effective treat many types of radioactive waste, reduce the storage hazards and disposal costs, and minimize the generation of secondary waste streams. The focus has been on the chemistry of plutonium(VI) in solution with carbonate since these are expected to be important species in the effluent from hydrothermal oxidation of Pu-containing organic wastes. The authors investigated the structure, solubility, and stability of the key plutonium complexes. Installation and testing of flow and batch hydrothermal reactors in the Plutonium Facility was accomplished. Preliminary testing with Pu-contaminated organic solutions gave effluent solutions that readily met discard requirements. A new effort in FY 1998 will build on these promising initial results.

  3. Integration mockup and process material management system

    Science.gov (United States)

    Verble, Adas James, Jr.

    1992-01-01

    Work to define and develop a full scale Space Station Freedom (SSF) mockup with the flexibility to evolve into future designs, to validate techniques for maintenance and logistics and verify human task allocations and support trade studies is described. This work began in early 1985 and ended in August, 1991. The mockups are presently being used at MSFC in Building 4755 as a technology and design testbed, as well as for public display. Micro Craft also began work on the Process Material Management System (PMMS) under this contract. The PMMS simulator was a sealed enclosure for testing to identify liquids, gaseous, particulate samples, and specimen including, urine, waste water, condensate, hazardous gases, surrogate gasses, liquids, and solids. The SSF would require many trade studies to validate techniques for maintenance and logistics and verify system task allocations; it was necessary to develop a full scale mockup which would be representative of current SSF design with the ease of changing those designs as the SSF design evolved and changed. The tasks defined for Micro Craft were to provide the personnel, services, tools, and materials for the SSF mockup which would consist of four modules, nodes, interior components, and part task mockups of MSFC responsible engineering systems. This included the Engineering Control and Life Support Systems (ECLSS) testbed. For the initial study, the mockups were low fidelity, soft mockups of graphics art bottle, and other low cost materials, which evolved into higher fidelity mockups as the R&D design evolved, by modifying or rebuilding, an important cost saving factor in the design process. We designed, fabricated, and maintained the full size mockup shells and support stands. The shells consisted of cylinders, end cones, rings, longerons, docking ports, crew airlocks, and windows. The ECLSS required a heavier cylinder to support the ECLSS systems test program. Details of this activity will be covered. Support stands were

  4. Integration of bulk piezoelectric materials into microsystems

    Science.gov (United States)

    Aktakka, Ethem Erkan

    Bulk piezoelectric ceramics, compared to deposited piezoelectric thin-films, provide greater electromechanical coupling and charge capacity, which are highly desirable in many MEMS applications. In this thesis, a technology platform is developed for wafer-level integration of bulk piezoelectric substrates on silicon, with a final film thickness of 5-100microm. The characterized processes include reliable low-temperature (200°C) AuIn diffusion bonding and parylene bonding of bulk-PZT on silicon, wafer-level lapping of bulk-PZT with high-uniformity (+/-0.5microm), and low-damage micro-machining of PZT films via dicing-saw patterning, laser ablation, and wet-etching. Preservation of ferroelectric and piezoelectric properties is confirmed with hysteresis and piezo-response measurements. The introduced technology offers higher material quality and unique advantages in fabrication flexibility over existing piezoelectric film deposition methods. In order to confirm the preserved bulk properties in the final film, diaphragm and cantilever beam actuators operating in the transverse-mode are designed, fabricated and tested. The diaphragm structure and electrode shapes/sizes are optimized for maximum deflection through finite-element simulations. During tests of fabricated devices, greater than 12microm PP displacement is obtained by actuation of a 1mm2 diaphragm at 111kHz with management IC, which incorporates a supply-independent bias circuitry, an active diode for low-dropout rectification, a bias-flip system for higher efficiency, and a trickle battery charger. The overall system does not require a pre-charged battery, and has power consumption of sleep-mode (simulated). Under lg vibration at 155Hz, a 70mF ultra-capacitor is charged from OV to 1.85V in 50 minutes.

  5. Thermal Energy Storage with Phase Change Material

    Directory of Open Access Journals (Sweden)

    Lavinia Gabriela SOCACIU

    2012-08-01

    Full Text Available Thermal energy storage (TES systems provide several alternatives for efficient energy use and conservation. Phase change materials (PCMs for TES are materials supplying thermal regulation at particular phase change temperatures by absorbing and emitting the heat of the medium. TES in general and PCMs in particular, have been a main topic in research for the last 30 years, but although the information is quantitatively enormous, it is also spread widely in the literature, and difficult to find. PCMs absorb energy during the heating process as phase change takes place and release energy to the environment in the phase change range during a reverse cooling process. PCMs possesses the ability of latent thermal energy change their state with a certain temperature. PCMs for TES are generally solid-liquid phase change materials and therefore they need encapsulation. TES systems using PCMs as a storage medium offers advantages such as high TES capacity, small unit size and isothermal behaviour during charging and discharging when compared to the sensible TES.

  6. Phase change material thermal capacitor clothing

    Science.gov (United States)

    Buckley, Theresa M. (Inventor)

    2005-01-01

    An apparatus and method for metabolic cooling and insulation of a user in a cold environment. In its preferred embodiment the apparatus is a highly flexible composite material having a flexible matrix containing a phase change thermal storage material. The apparatus can be made to heat or cool the body or to act as a thermal buffer to protect the wearer from changing environmental conditions. The apparatus may also include an external thermal insulation layer and/or an internal thermal control layer to regulate the rate of heat exchange between the composite and the skin of the wearer. Other embodiments of the apparatus also provide 1) a path for evaporation or direct absorption of perspiration from the skin of the wearer for improved comfort and thermal control, 2) heat conductive pathways within the material for thermal equalization, 3) surface treatments for improved absorption or rejection of heat by the material, and 4) means for quickly regenerating the thermal storage capacity for reuse of the material. Applications of the composite materials are also described which take advantage of the composite's thermal characteristics. The examples described include a diver's wet suit, ski boot liners, thermal socks, gloves and a face mask for cold weather activities, and a metabolic heating or cooling blanket useful for treating hypothermia or fever patients in a medical setting and therapeutic heating or cooling orthopedic joint supports.

  7. Enhancing the performance of BICPV systems using phase change materials

    Science.gov (United States)

    Sharma, Shivangi; Sellami, Nazmi; Tahir, Asif; Reddy, K. S.; Mallick, Tapas K.

    2015-09-01

    Building Integrated Concentrated Photovoltaic (BICPV) systems have three main benefits for integration into built environments, namely, (i) generating electricity at the point of use (ii) allowing light efficacy within the building envelope and (iii) providing thermal management. In this work, to maintain solar cell operating temperature and improve its performance, a phase change material (PCM) container has been designed, developed and integrated with the BICPV system. Using highly collimated continuous light source, an indoor experiment was performed. The absolute electrical power conversion efficiency for the module without PCM cooling resulted in 7.82% while using PCM increased it to 9.07%, thus showing a relative increase by 15.9% as compared to a non- PCM system. A maximum temperature reduction of 5.2°C was also observed when the BICPV module was integrated with PCM containment as compared to the BICPV system without any PCM containment.

  8. Integrating Sustainable Construction Materials to Achieve Green Building

    Directory of Open Access Journals (Sweden)

    Abdelmajeed H. Kasassbeh

    2015-07-01

    Full Text Available Green buildings integrate building materials and methods that promote environmental quality, economic vitality and social benefits through the design, construction and operation of the built environment. This study demonstrates potential actions including material selection that can be implemented to achieve green building. Also, we discuss the importance and environmental impact of sustainable material, the selection criteria of these materials and the different types of sustainable materials in the buildings construction in Jordan.

  9. Towards an integrated materials characterization toolbox

    DEFF Research Database (Denmark)

    Robertson, Ian M.; Schuh, Christopher A.; Vetrano, John S.

    2011-01-01

    The material characterization toolbox has recently experienced a number of parallel revolutionary advances, foreshadowing a time in the near future when material scientists can quantify material structure evolution across spatial and temporal space simultaneously. This will provide insight...... to reaction dynamics in four-dimensions, spanning multiple orders of magnitude in both temporal and spatial space. This study presents the authors' viewpoint on the material characterization field, reviewing its recent past, evaluating its present capabilities, and proposing directions for its future...... development. Electron microscopy; atom probe tomography; x-ray, neutron and electron tomography; serial sectioning tomography; and diffraction-based analysis methods are reviewed, and opportunities for their future development are highlighted. Advances in surface probe microscopy have been reviewed recently...

  10. Integrating the stabilization of nuclear materials

    Energy Technology Data Exchange (ETDEWEB)

    Dalton, H.F. [Department of Energy, Washington, DC (United States)

    1996-05-01

    In response to Recommendation 94-1 of the Defense Nuclear Facilities Safety Board, the Department of Energy committed to stabilizing specific nuclear materials within 3 and 8 years. These efforts are underway. The Department has already repackaged the plutonium at Rocky Flats and metal turnings at Savannah River that had been in contact with plastic. As this effort proceeds, we begin to look at activities beyond stabilization and prepare for the final disposition of these materials. To describe the plutonium materials being stabilize, Figure 1 illustrates the quantities of plutonium in various forms that will be stabilized. Plutonium as metal comprises 8.5 metric tons. Plutonium oxide contains 5.5 metric tons of plutonium. Plutonium residues and solutions, together, contain 7 metric tons of plutonium. Figure 2 shows the quantity of plutonium-bearing material in these four categories. In this depiction, 200 metric tons of plutonium residues and 400 metric tons of solutions containing plutonium constitute most of the material in the stabilization program. So, it is not surprising that much of the work in stabilization is directed toward the residues and solutions, even though they contain less of the plutonium.

  11. Towards an integrated materials characterization toolbox

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, Ian M [University of Illinois, Chicago; Schuh, Christopher A. [Massachusetts Institute of Technology (MIT); Vetrano, John S [Office of Basic Energy Sciences, U.S. Dept. of Energy, Washington DC; Browning, Nigel D. [University of California, Davis; Field, D P [Washington State University; Jensen, D J [Riso National Laboratory, Roskilde, Denmark; Miller, Michael K [ORNL; Baker, Ian [Dartmouth College; Dunand, D C [Northwestern University, Evanston; Dunin-Borkowski, R [Technical University of Denmark; Kabius, B [Argonne National Laboratory (ANL); Kelly, T. F. [Imago Scientific Instruments, Madison, WI; Lozano-Perez, S [University of Oxford; Misra, A [Los Alamos National Laboratory (LANL); Rohrer, A [Carnegie Mellon University; Rollett, A [Carnegie Mellon University; Taheri, M [Drexel University; Thompson, G. B. [University of Alabama, Tuscaloosa; Uchic, M [Air Force Research Laboratory, Wright-Patterson AFB, OH; Wang, Xun-Li [ORNL; Was, G [University of Michigan

    2011-01-01

    The material characterization toolbox has recently experienced a number of parallel revolutionary advances, foreshadowing a time in the near future when material scientists can quantify material structure evolution across spatial and temporal space simultaneously. This will provide insight to reaction dynamics in four-dimensions, spanning multiple orders of magnitude in both temporal and spatial space. This study presents the authors viewpoint on the material characterization field, reviewing its recent past, evaluating its present capabilities, and proposing directions for its future development. Electron microscopy; atom probe tomography; x-ray, neutron and electron tomography; serial sectioning tomography; and diffraction-based analysis methods are reviewed, and opportunities for their future development are highlighted. Advances in surface probemicroscopy have been reviewed recently and, therefore, are not included [D.A.Bonnell et al.: Rev.Modern Phys. in Review]. In this study particular attention is paid to studies that have pioneered the synergetic use of multiple techniques to provide complementary views of a single structure or process; several of these studies represent the state-of-the-art in characterization and suggest a trajectory for the continued development of the field. Based on this review, a set of grand challenges for characterization science is identified, including suggestions for instrumentation advances, scientific problems in microstructure analysis, and complex structure evolution problems involving material damage. The future of microstructural characterization is proposed to be one not only where individual techniques are pushed to their limits, but where the community devises strategies of technique synergy to address complex multiscale problems in materials science and engineering.

  12. Towards an integrated materials characterization toolbox

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, Ian M.; Schuh, Christopher A.; Vetrano, John S.; Browning, Nigel; Field, David P.; Jensen, Dorte J.; Miller, Michael K.; Baker, Ian; Dunand, David C.; Dunin-Borkowski, Rafal; Kabius, Bernd C.; Kelly, Tom; Lozano-Perez, Sergio; Misra, Amit; Rohrer, Gregory S.; Rollett, D.; Taheri, Mitra L.; Thompson, Greg B.; Uchic, Michael; Wang, Xun-Li; Was, Gary S.

    2011-06-14

    The material characterization toolbox has recently experienced a number of parallel revolutionary advances, foreshadowing a time in the near future when material scientists can quantify material structure evolution across spatial and temporal space simultaneously. This will provide insight to reaction dynamics in four-dimensions, spanning multiple orders of magnitude in both temporal and spatial space. This study presents the authors’ viewpoint on the material characterization field, reviewing its recent past, evaluating its present capabilities, and proposing directions for its future development. Electron microscopy; atom probe tomography; x-ray, neutron and electron tomography; serial sectioning tomography; and diffraction-based analysis methods are reviewed, and opportunities for their future development are highlighted. Advances in surface probemicroscopy have been reviewed recently and, therefore, are not included [D.A.Bonnell et al.: Rev.Modern Phys. in Review]. In this study particular attention is paid to studies that have pioneered the synergetic use of multiple techniques to provide complementary views of a single structure or process; several of these studies represent the stateof- the-art in characterization and suggest a trajectory for the continued development of the field. Based on this review, a set of grand challenges for characterization science is identified, including suggestions for instrumentation advances, scientific problems in microstructure analysis, and complex structure evolution problems involving material damage. The future of microstructural characterization is proposed to be one not only where individual techniques are pushed to their limits, but where the community devises strategies of technique synergy to address complex multiscale problems in materials science and engineering.

  13. Towards an integrated materials characterization toolbox.

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, I. M.; Schuh, C. A.; Vetrano, J. S.; Browning, N. D.; Field, D. P.; Jensen, D. J.; Miller, M. K.; Baker, I.; Dunand, D. C.; Dunin-Borkowski, R.; KABIUS, B.; Kelly, T.; Lozano-Perez, S.; Misra, A.; Rohrer, G. S.; Rollett, A. D.; Taheri, M. L.; Thompson, G. B.; Uchic, M.; Wang, X-L.; Was, G. (Materials Science Division); (Univ. Illinois-Urbana); (Massachusetts Inst. Tech.); (US DOE); (Univ. California-Davis); (Lawrence Livermore Nat. Lab.); (Washington State Univ.); (Tech. Univ. Denmark); (Oak Ridge Nat. Lab.); (Dartmouth College); (Northwestern Univ.); (Cameca Instruments Corp.); (Univ. Oxford); (Los Alamos Nat. Lab.); (Carnegie Mellon Univ.); (Drexel Univ.)

    2011-06-01

    The material characterization toolbox has recently experienced a number of parallel revolutionary advances, foreshadowing a time in the near future when material scientists can quantify material structure evolution across spatial and temporal space simultaneously. This will provide insight to reaction dynamics in four-dimensions, spanning multiple orders of magnitude in both temporal and spatial space. This study presents the authors viewpoint on the material characterization field, reviewing its recent past, evaluating its present capabilities, and proposing directions for its future development. Electron microscopy; atom probe tomography; x-ray, neutron and electron tomography; serial sectioning tomography; and diffraction-based analysis methods are reviewed, and opportunities for their future development are highlighted. Advances in surface probe microscopy have been reviewed recently and, therefore, are not included [D.A. Bonnell et al.: Rev. Modern Phys. in Review]. In this study particular attention is paid to studies that have pioneered the synergetic use of multiple techniques to provide complementary views of a single structure or process; several of these studies represent the state-of-the-art in characterization and suggest a trajectory for the continued development of the field. Based on this review, a set of grand challenges for characterization science is identified, including suggestions for instrumentation advances, scientific problems in microstructure analysis, and complex structure evolution problems involving material damage. The future of microstructural characterization is proposed to be one not only where individual techniques are pushed to their limits, but where the community devises strategies of technique synergy to address complex multiscale problems in materials science and engineering.

  14. Climate Change: Integrating Science and Economics

    Science.gov (United States)

    Prinn, R. G.

    2008-12-01

    The world is facing an ever-growing conflict between environment and development. Climate change is a century-scale threat requiring a century-long effort in science, technology and policy analysis, and institutions that can sustain this effort over generations. To inform policy development and implementation there is urgent need for better integration of the diverse components of the problem. Motivated by this challenge, we have developed the Integrated Global System Model (IGSM) at MIT. It comprises coupled sub- models of economic development, atmospheric chemistry, climate dynamics and ecosystems. The results of a recent uncertainty analysis involving hundreds of runs of the IGSM imply that, without mitigation policies, the global average surface temperature may rise much faster than previously estimated. Polar temperatures are projected to rise even faster than the average rate with obvious great risks for high latitude ecosystems and ice sheets at the high end of this range. Analysis of policies for climate mitigation, show that the greatest effect of these policies is to lower the probability of extreme changes as opposed to lowering the medians. Faced with the above estimated impacts, the long lifetimes of most greenhouse gases in the atmosphere, the long delay in ultimate warming due to ocean heat uptake, and the capital-intensive global energy infrastructure, the case is strong for concerted action now. Results of runs of the IGSM indicate the need for transformation of the global energy industry on a very large scale to mitigate climate change. Carbon sequestration, renewable energy sources, and nuclear present new economic, technological, and environmental challenges when implemented at the needed scales. Economic analyses using the IGSM indicate that global implementation of efficient policies could allow the needed transformations at bearable costs.

  15. Integrated nuclear techniques to detect illicit materials

    Energy Technology Data Exchange (ETDEWEB)

    DeVolpi, A.

    1997-10-01

    This paper discusses the problem of detecting explosives in the context of an object being transported for illicit purposes. The author emphasizes that technologies developed for this particular application have payoffs in many related problem areas. The author discusses nuclear techniques which can be applied to this detection problem. These include: x-ray imaging; neutronic interrogation; inelastic neutron scattering; fieldable neutron generators. He discusses work which has been done on the applications of these technologies, including results for detection of narcotics. He also discusses efforts to integrate these techniques into complementary systems which offer improved performance.

  16. Heterogeneous Monolithic Integration of Single-Crystal Organic Materials.

    Science.gov (United States)

    Park, Kyung Sun; Baek, Jangmi; Park, Yoonkyung; Lee, Lynn; Hyon, Jinho; Koo Lee, Yong-Eun; Shrestha, Nabeen K; Kang, Youngjong; Sung, Myung Mo

    2017-02-01

    Manufacturing high-performance organic electronic circuits requires the effective heterogeneous integration of different nanoscale organic materials with uniform morphology and high crystallinity in a desired arrangement. In particular, the development of high-performance organic electronic and optoelectronic devices relies on high-quality single crystals that show optimal intrinsic charge-transport properties and electrical performance. Moreover, the heterogeneous integration of organic materials on a single substrate in a monolithic way is highly demanded for the production of fundamental organic electronic components as well as complex integrated circuits. Many of the various methods that have been designed to pattern multiple heterogeneous organic materials on a substrate and the heterogeneous integration of organic single crystals with their crystal growth are described here. Critical issues that have been encountered in the development of high-performance organic integrated electronics are also addressed.

  17. Bond strength of W-Cu/CuCr integrated material

    Institute of Scientific and Technical Information of China (English)

    范志康; 梁淑华; 薛旭

    2001-01-01

    The bond strength of W-Cu/CuCr integrated material was investigated. The results show that the fracture of W-Cu/CuCr integrated material often takes place at W-Cu/CuCr interface. Some alloying elements enhance the bond of W and CuCr alloy, which results in the increase of the strength of the W-Cu/CuCr interface. And the fracture of the WCu/CuCr integrated material occurs in the CuCr alloy part, not at the W-Cu/CuCr interface. Chromium in CuCr alloy part of the integrated material can improve Cr diffusing from the CuCr alloy to W-Cu composite and can be alloyed (near the W-Cu/CuCr interface) in the W-Cu composite. Thus the strength of W-Cu/CuCr interface is also increased.

  18. Phase Change Material Thermal Power Generator

    Science.gov (United States)

    Jones, Jack A.

    2013-01-01

    An innovative modification has been made to a previously patented design for the Phase Change Material (PCM) Thermal Generator, which works in water where ocean temperature alternatively melts wax in canisters, or allows the wax to re-solidify, causing high-pressure oil to flow through a hydraulic generator, thus creating electricity to charge a battery that powers the vehicle. In this modification, a similar thermal PCM device has been created that is heated and cooled by the air and solar radiation instead of using ocean temperature differences to change the PCM from solid to liquid. This innovation allows the device to use thermal energy to generate electricity on land, instead of just in the ocean.

  19. Material Engineering for Phase Change Memory

    Science.gov (United States)

    Cabrera, David M.

    As semiconductor devices continue to scale downward, and portable consumer electronics become more prevalent there is a need to develop memory technology that will scale with devices and use less energy, while maintaining performance. One of the leading prototypical memories that is being investigated is phase change memory. Phase change memory (PCM) is a non-volatile memory composed of 1 transistor and 1 resistor. The resistive structure includes a memory material alloy which can change between amorphous and crystalline states repeatedly using current/voltage pulses of different lengths and magnitudes. The most widely studied PCM materials are chalcogenides - Germanium-Antimony-Tellerium (GST) with Ge2Sb2Te3 and Germanium-Tellerium (GeTe) being some of the most popular stochiometries. As these cells are scaled downward, the current/voltage needed to switch these materials becomes comparable to the voltage needed to sense the cell's state. The International Roadmap for Semiconductors aims to raise the threshold field of these devices from 66.6 V/mum to be at least 375 V/mum for the year 2024. These cells are also prone to resistance drift between states, leading to bit corruption and memory loss. Phase change material properties are known to influence PCM device performance such as crystallization temperature having an effect on data retention and litetime, while resistivity values in the amorphous and crystalline phases have an effect on the current/voltage needed to write/erase the cell. Addition of dopants is also known to modify the phase change material parameters. The materials G2S2T5, GeTe, with dopants - nitrogen, silicon, titanium, and aluminum oxide and undoped Gallium-Antimonide (GaSb) are studied for these desired characteristics. Thin films of these compositions are deposited via physical vapor deposition at IBM Watson Research Center. Crystallization temperatures are investigated using time resolved x-ray diffraction at Brookhaven National Laboratory

  20. Integrating uncertainties for climate change mitigation

    Science.gov (United States)

    Rogelj, Joeri; McCollum, David; Reisinger, Andy; Meinshausen, Malte; Riahi, Keywan

    2013-04-01

    The target of keeping global average temperature increase to below 2°C has emerged in the international climate debate more than a decade ago. In response, the scientific community has tried to estimate the costs of reaching such a target through modelling and scenario analysis. Producing such estimates remains a challenge, particularly because of relatively well-known, but ill-quantified uncertainties, and owing to limited integration of scientific knowledge across disciplines. The integrated assessment community, on one side, has extensively assessed the influence of technological and socio-economic uncertainties on low-carbon scenarios and associated costs. The climate modelling community, on the other side, has worked on achieving an increasingly better understanding of the geophysical response of the Earth system to emissions of greenhouse gases (GHG). This geophysical response remains a key uncertainty for the cost of mitigation scenarios but has only been integrated with assessments of other uncertainties in a rudimentary manner, i.e., for equilibrium conditions. To bridge this gap between the two research communities, we generate distributions of the costs associated with limiting transient global temperature increase to below specific temperature limits, taking into account uncertainties in multiple dimensions: geophysical, technological, social and political. In other words, uncertainties resulting from our incomplete knowledge about how the climate system precisely reacts to GHG emissions (geophysical uncertainties), about how society will develop (social uncertainties and choices), which technologies will be available (technological uncertainty and choices), when we choose to start acting globally on climate change (political choices), and how much money we are or are not willing to spend to achieve climate change mitigation. We find that political choices that delay mitigation have the largest effect on the cost-risk distribution, followed by

  1. Integrated Assessment Systems for Chemical Warfare Material

    Energy Technology Data Exchange (ETDEWEB)

    A. M. Snyder; D. A. Verrill; G. L. Thinnes; K. D. Watts; R. J. McMorland

    1999-05-27

    The US Army must respond to a variety of situations involving suspect discovered, recovered, stored, and buried chemical warfare materiel (CWM). In some cases, the identity of the fill materiel and the status of the fusing and firing train cannot be visually determined due to aging of the container, or because the item is contained in an over-pack. In these cases, non-intrusive assessments are required to provide information to allow safe handling, storage, and disposal of the materiel. This paper will provide an overview of the integrated mobile and facility-based CWM assessment system prototypes that have been, and are being developed, at the Idaho National Engineering and Environmental Laboratory (INEEL) for the US Army Non-Stockpile Chemical Materiel Project. In addition, this paper will discuss advanced sensors being developed to enhance the capability of the existing and future assessment systems. The Phase I Mobile Munitions Assessment System (MMAS) is currently being used by the Army's Technical Escort Unit (TEU) at Dugway Proving Ground, Utah. This system includes equipment for non-intrusively identifying the munitions fill materiel and for assessing the condition and stability of the fuzes, firing trains, and other potential safety hazards. The system provides a self-contained, integrated command post including an on-board computer system, communications equipment, video and photographic equipment, weather monitoring equipment, and miscellaneous safety-related equipment. The Phase II MMAS is currently being tested and qualified for use by the INEEL and the US Army. The Phase II system contains several new assessment systems that significantly enhance the ability to assess CWM. A facility-based munitions assessment system prototype is being developed for the assessment of CWM stored in igloos at Pine Bluff Arsenal, Arkansas. This system is currently in the design and fabrication stages. Numerous CWM advanced sensors are being developed and tested, and

  2. Integrating Material on the Internment into Anthropology and Women's Studies.

    Science.gov (United States)

    Sacks, Karen B.

    1993-01-01

    Describes plans to use material from a seminar on integrating material about the Japanese-American internment in World War II into the curriculum of the University of California Los Angeles. Describes efforts to develop a unit on the gender and racial dimensions of internment for a women's studies course. (SLD)

  3. Phase Change Materials for Thermal Management of IC Packages

    Directory of Open Access Journals (Sweden)

    P. Fiala

    2007-06-01

    Full Text Available This paper deals with the application of phase change materials (PCM for thermal management of integrated circuits as a viable alternative to active forced convection cooling systems. The paper presents an analytical description and solution of heat transfer, melting and freezing process in 1D which is applied to inorganic crystalline salts. There are also results of numerical simulation of a real 3D model. These results were obtained by means of the finite element method (FEM. Results of 3D numerical solutions were verified experimentally.

  4. Electrical transport in crystalline phase change materials

    Energy Technology Data Exchange (ETDEWEB)

    Woda, Michael

    2012-01-06

    In this thesis, the electrical transport properties of crystalline phase change materials are discussed. Phase change materials (PCM) are a special class of semiconducting and metallic thin film alloys, typically with a high amount of the group five element antimony or the group six element tellurium, such as Ge{sub 2}Sb{sub 2}Te{sub 5}. The unique property portfolio of this material class makes it suitable for memory applications. PCMs reveal fast switching between two stable room-temperature phases (amorphous and crystalline) realized by optical laser or electrical current pulses in memory devices. Additionally, a pronounced property contrast in form of optical reflectivity and electrical conductivity between the amorphous and crystalline phase is the characteristic fingerprint of PCMs. The emerging electrical solid state memory PCRAM is a very promising candidate to replace Flash memory in the near future or to even become a universal memory, which is non-volatile and shows the speed and cyclability of DRAM. One of the main technological challenges is the switching process into the amorphous state, which is the most power demanding step. In order to reduce the switching power, the crystalline resistivity needs to be increased at a given voltage. Thus understanding and tayloring of this property is mandatory. In this work, first the technological relevance, i.e. optical and electrical memory concepts based on PCMs are introduced. Subsequently a description of the physical properties of PCMs in four categories is given. Namely, structure, kinetics, optical properties and electrical properties are discussed. Then important recent developments such as the identification of resonant bonding in crystalline PCMs and a property predicting coordination scheme are briefly reviewed. The following chapter deals with the theoretical background of electrical transport, while the next chapter introduces the experimental techniques: Sputtering, XRR, XRD, DSC, thermal annealing

  5. "Responding to Climate Change" Course: Research Integration

    Science.gov (United States)

    Pfirman, S. L.; Bowman, J. S.

    2015-12-01

    The "Responding to Climate Change" Barnard/Columbia course integrates current research as well as hands-on research-based activities modified for a classroom environment. The course covers the major response themes of adaptation, mitigation and communication. In the spring of 2015 the course was oriented around Arctic and Antarctic case studies. Each week a different theme is addressed, such as the physical setting, changing ecosystems, governance issues, perspectives of residents and indigenous peoples, geoengineering, commercial interests, security, and health and developmental issues. Frequent guest lectures from thematic experts keep the course grounded in realities and present the students with cutting edge issues. Activities match the weekly theme, for example during the week on Arctic development, students engage with the marine spatial planning simulation Arctic SMARTIC (Strategic Management of Resources in Times of Change) based on research on Arctic sea ice trends and projections coupled with current and projected developmental interests of stakeholders. Created under the Polar Learning and Responding: PoLAR Climate Change Education Partnership (thepolarhub.org), a complete set of SMARTIC resources is available on line for use by others (http://www.camelclimatechange.org/view/article/175297/). The Responding to Climate Change course is designed to be current and respond to events. For the Arctic case study, students developed proposals for the US State Department as the upcoming Chair of the Arctic Council. Student evaluations indicated that they appreciated the opportunity to connect science with policy and presentation of preliminary proposals in a workshop format was valued as a way to develop and hone their ideas. An additional finding was that students were surprisingly tolerant of technical issues when guest lecturers were linked in via Skype, allowing interaction with thematic experts across the US. Students commented positively on this exposure to

  6. Implicit integration of plasticity models for granular materials

    DEFF Research Database (Denmark)

    Ahadi, A.; Krenk, Steen

    2003-01-01

    A stress integration algorithm for granular materials based on fully implicit integration with explicit updating is presented. In the implicit method the solution makes use of the gradient to the potential surface at the final stress state which is unknown. The final stress and hardening parameters...... are determined solving the non-linear equations iteratively so that the stress increment fulfills the consistency condition. The integration algorithm is applicable for models depending on all the three stress invariants and it is applied to a characteristic state model for granular material. Since tensile...... of the integration algorithm are illustrated by simulating both drained and undrained triaxial tests on sand. The algorithm is developed in a standard format which can be implemented in several general purpose finite element codes. It has been implemented as an ABAQUS subroutine, and a traditional geotechnical...

  7. Integrated Photonic Devices Incorporating Low-Loss Fluorinated Polymer Materials

    Directory of Open Access Journals (Sweden)

    Hyung-Jong Lee

    2011-06-01

    Full Text Available Low-loss polymer materials incorporating fluorinated compounds have been utilized for the investigation of various functional optical devices useful for optical communication and optical sensor systems. Since reliability issues concerning the polymer device have been resolved, polymeric waveguide devices have been gradually adopted for commercial application systems. The two most successfully commercialized polymeric integrated optic devices, variable optical attenuators and digital optical switches, are reviewed in this paper. Utilizing unique properties of optical polymers which are not available in other optical materials, novel polymeric optical devices are proposed including widely tunable external cavity lasers and integrated optical current sensors.

  8. Accelerating the design of biomimetic materials by integrating RNA-seq with proteomics and materials science.

    Science.gov (United States)

    Guerette, Paul A; Hoon, Shawn; Seow, Yiqi; Raida, Manfred; Masic, Admir; Wong, Fong T; Ho, Vincent H B; Kong, Kiat Whye; Demirel, Melik C; Pena-Francesch, Abdon; Amini, Shahrouz; Tay, Gavin Z; Ding, Dawei; Miserez, Ali

    2013-10-01

    Efforts to engineer new materials inspired by biological structures are hampered by the lack of genomic data from many model organisms studied in biomimetic research. Here we show that biomimetic engineering can be accelerated by integrating high-throughput RNA-seq with proteomics and advanced materials characterization. This approach can be applied to a broad range of systems, as we illustrate by investigating diverse high-performance biological materials involved in embryo protection, adhesion and predation. In one example, we rapidly engineer recombinant squid sucker ring teeth proteins into a range of structural and functional materials, including nanopatterned surfaces and photo-cross-linked films that exceed the mechanical properties of most natural and synthetic polymers. Integrating RNA-seq with proteomics and materials science facilitates the molecular characterization of natural materials and the effective translation of their molecular designs into a wide range of bio-inspired materials.

  9. Phase Change Material Heat Exchanger Life Test

    Science.gov (United States)

    Lillibridge, Sean; Stephan, Ryan

    2009-01-01

    Low Lunar Orbit (LLO) poses unique thermal challenges for the orbiting space craft, particularly regarding the performance of the radiators. The IR environment of the space craft varies drastically from the light side to the dark side of the moon. The result is a situation where a radiator sized for the maximal heat load in the most adverse situation is subject to freezing on the dark side of the orbit. One solution to this problem is to implement Phase Change Material (PCM) Heat Exchangers. PCM Heat Exchangers act as a "thermal capacitor," storing thermal energy when there is too much being produced by the space craft to reject to space, and then feeding that energy back into the thermal loop when conditions are more favorable. Because they do not use an expendable resource, such as the feed water used by sublimators and evaporators, PCM Heat Exchangers are ideal for long duration LLO missions. In order to validate the performance of PCM Heat Exchangers, a life test is being conducted on four n-Pentadecane, carbon filament heat exchangers. Fluid loop performance, repeatability, and measurement of performance degradation over 2500 melt-freeze cycles will be performed.

  10. EDDA: integrated simulation of debris flow erosion, deposition and property changes

    OpenAIRE

    Chen, H. X.; Zhang, L. M.

    2014-01-01

    Debris flow material properties change during the initiation, transportation and deposition processes, which influences the runout characteristics of the debris flow. A quasi-three-dimensional depth-integrated numerical model, EDDA, is presented in this paper to simulate debris flow erosion, deposition and induced material property changes. The model considers changes in debris flow density, yield stress and dynamic viscosity during the flow process. The yie...

  11. EDDA 1.0: integrated simulation of debris flow erosion, deposition and property changes

    OpenAIRE

    Chen, H. X.; Zhang, L. M.

    2015-01-01

    Debris flow material properties change during the initiation, transportation and deposition processes, which influences the runout characteristics of the debris flow. A quasi-three-dimensional depth-integrated numerical model, EDDA (Erosion–Deposition Debris flow Analysis), is presented in this paper to simulate debris flow erosion, deposition and induced material property changes. The model considers changes in debris flow density, yield stress and dynamic viscosity during ...

  12. Structural integrity of materials in nuclear service: a bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Heddleson, F.A.

    1977-06-07

    This report contains 679 abstracts from the Nuclear Safety Information Center (NSIC) computer file dated 1973 through 1976 covering material properties with respect to structural integrity. All materials important to the nuclear industry (except concrete) are covered for mechanical properties, chemical properties, corrosion, fracture or failure, radiation damage, creep, cracking, and swelling. Keyword, author, and permuted-title indexes are included for the convenience of the user.

  13. Materials integration issues for high performance fusion power systems.

    Energy Technology Data Exchange (ETDEWEB)

    Smith, D. L.

    1998-01-14

    One of the primary requirements for the development of fusion as an energy source is the qualification of materials for the frost wall/blanket system that will provide high performance and exhibit favorable safety and environmental features. Both economic competitiveness and the environmental attractiveness of fusion will be strongly influenced by the materials constraints. A key aspect is the development of a compatible combination of materials for the various functions of structure, tritium breeding, coolant, neutron multiplication and other special requirements for a specific system. This paper presents an overview of key materials integration issues for high performance fusion power systems. Issues such as: chemical compatibility of structure and coolant, hydrogen/tritium interactions with the plasma facing/structure/breeder materials, thermomechanical constraints associated with coolant/structure, thermal-hydraulic requirements, and safety/environmental considerations from a systems viewpoint are presented. The major materials interactions for leading blanket concepts are discussed.

  14. Integrating Methods and Materials: Developing Trainees' Reading Skills.

    Science.gov (United States)

    Jarvis, Jennifer

    1987-01-01

    Explores issues arising from a research project which studied ways of meeting the reading needs of trainee primary school teachers (from Malawi and Tanzania) of English as a foreign language. Topics discussed include: the classroom teaching situation; teaching "quality"; and integration of materials and methods. (CB)

  15. Multi-Scale Material and Technology for Heterogeneous Integration

    NARCIS (Netherlands)

    Poelma, R.H.

    2016-01-01

    This thesis describes a series of experiments and fabrication methods on high-aspect-ratio 3D microstructures for wafer level packaging and 3D heterogeneous system integration (3D-HSI) using novel materials such as carbon nanotubes and thick-film photo-resists. Furthermore, theoretical and experimen

  16. Integrating CAD/CAM in Automation and Materials Handling

    Science.gov (United States)

    Deal, Walter F.; Jones, Catherine E.

    2012-01-01

    Humans by their very nature are users of tools, materials, and processes as a part of their survival and existence. As humans have progressed over time, their civilizations and societies have changed beyond imagination and have moved from hunters and gatherers of food and materials for survival to sophisticated societies with complex social and…

  17. Defense Nuclear Material Stewardship Integrated Inventory Information Management System (IIIMS).

    Energy Technology Data Exchange (ETDEWEB)

    Aas, Christopher A.; Lenhart, James E.; Bray, Olin H.; Witcher, Christina Jenkin

    2004-11-01

    Sandia National Laboratories was tasked with developing the Defense Nuclear Material Stewardship Integrated Inventory Information Management System (IIIMS) with the sponsorship of NA-125.3 and the concurrence of DOE/NNSA field and area offices. The purpose of IIIMS was to modernize nuclear materials management information systems at the enterprise level. Projects over the course of several years attempted to spearhead this modernization. The scope of IIIMS was broken into broad enterprise-oriented materials management and materials forecasting. The IIIMS prototype was developed to allow multiple participating user groups to explore nuclear material requirements and needs in detail. The purpose of material forecasting was to determine nuclear material availability over a 10 to 15 year period in light of the dynamic nature of nuclear materials management. Formal DOE Directives (requirements) were needed to direct IIIMS efforts but were never issued and the project has been halted. When restarted, duplicating or re-engineering the activities from 1999 to 2003 is unnecessary, and in fact future initiatives can build on previous work. IIIMS requirements should be structured to provide high confidence that discrepancies are detected, and classified information is not divulged. Enterprise-wide materials management systems maintained by the military can be used as overall models to base IIIMS implementation concepts upon.

  18. Ultrafast laser inscribed integrated photonics: material science to device development

    Directory of Open Access Journals (Sweden)

    Gross S.

    2013-11-01

    Full Text Available Detailed studies of intense light – material interactions has led to new insights into fs laser induced refractive index change in a range of glass types. This body of knowledge enables the development of advanced processing methodologies, resulting in novel planar and 3D guided wave devices. We will review the chemistry and morphology associated with fs laser induced refractive index change in multi-component glasses such as ZBLAN, phosphates and silicates, and discuss how these material changes inform our research programs developing a range of active and passive lightwave systems.

  19. Integrating UNESCO ICT-Based Instructional Materials in Chemistry Lessons

    Directory of Open Access Journals (Sweden)

    CHARLIE P. NACARIO

    2014-08-01

    Full Text Available This study determined the effectiveness of the lessons in Chemistry integrating UNESCO ICT-based instructional material on the achievement of Chemistry students at Central Bicol State University of Agriculture. It aimed to identify lessons that may be developed integrating UNESCO ICT-based instructional materials, determine the effect of the developed lessons using the material on: conceptual understanding; science process skills; and attitude towards chemistry and gather insights from the experiences of the students and teacher. The study used the single group pretest and posttest experimental design. Descriptive, quantitative and qualitative techniques were also utilized. Quantitative data were taken from the pretest-posttest results on the Test on Conceptual Understanding, Science Process Skills and Chemistry Attitudinaire. Qualitative data were drawn from the experts’ assessment of the developed lessons and research instruments, and the insights of students and teacher. The developed lessons integrating UNESCO ICT-based instructional materials were Atomic Model and Structure, Periodic Table of Elements, Chemical Bonding, and Balancing Chemical Equation. These lessons increased the conceptual understanding of the students by topic and skill from very low mastery to average mastery level. The students have slightly improved along the different science process skills. After teaching the lessons, the students’ attitude also improved. The students became more motivated and interested in Chemistry and the lessons were student centered and entailed teacher’s competence and flexibility in computer use.

  20. Development of integrated platform for computational material design

    Energy Technology Data Exchange (ETDEWEB)

    Kiyoshi, Matsubara; Kumi, Itai; Nobutaka, Nishikawa; Akifumi, Kato [Center for Computational Science and Engineering, Fuji Research Institute Corporation (Japan); Hideaki, Koike [Advance Soft Corporation (Japan)

    2003-07-01

    The goal of our project is to design and develop a problem-solving environment (PSE) that will help computational scientists and engineers develop large complicated application software and simulate complex phenomena by using networking and parallel computing. The integrated platform, which is designed for PSE in the Japanese national project of Frontier Simulation Software for Industrial Science, is defined by supporting the entire range of problem solving activity from program formulation and data setup to numerical simulation, data management, and visualization. A special feature of our integrated platform is based on a new architecture called TASK FLOW. It integrates the computational resources such as hardware and software on the network and supports complex and large-scale simulation. This concept is applied to computational material design and the project 'comprehensive research for modeling, analysis, control, and design of large-scale complex system considering properties of human being'. Moreover this system will provide the best solution for developing large and complicated software and simulating complex and large-scaled phenomena in computational science and engineering. A prototype has already been developed and the validation and verification of an integrated platform will be scheduled by using the prototype in 2003. In the validation and verification, fluid-structure coupling analysis system for designing an industrial machine will be developed on the integrated platform. As other examples of validation and verification, integrated platform for quantum chemistry and bio-mechanical system are planned.

  1. Reconstruction of Complex Materials by Integral Geometric Measures

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The goal of much research in computational materials science is to quantify necessary morphological information and then to develop stochastic models which both accurately reflect the material morphology and allow one to estimate macroscopic physical properties. A novel method of characterizing the morphology of disordered systems is presented based on the evolution of a family of integral geometric measures during erosion and dilation operations.The method is used to determine the accuracy of model reconstructions of random systems. It is shown that the use of erosion/dilation operations on the original image leads to a more accurate discrimination of morphology than previous methods.

  2. Organic Materials for Time-Temperature Integrator Devices.

    Science.gov (United States)

    Cavallini, Massimiliano; Melucci, Manuela

    2015-08-12

    Time-temperature integrators (TTIs) are devices capable of recording the thermal history of a system. They have an enormous impact in the food and pharmaceutical industries. TTIs exploit several irreversible thermally activated transitions such as recrystallization, dewetting, smoothening, chemical decomposition, and polymorphic transitions, usually considered drawbacks for many technological applications. The aim of this article is to sensitize research groups working in organic synthesis and surface science toward TTI devices, enlarging the prospects of many new materials. We reviewed the principal applications highlighting the need and criticisms of TTIs, which offer a new opportunity for the development of many materials.

  3. An integrated web medicinal materials DNA database: MMDBD (Medicinal Materials DNA Barcode Database

    Directory of Open Access Journals (Sweden)

    But Paul

    2010-06-01

    Full Text Available Abstract Background Thousands of plants and animals possess pharmacological properties and there is an increased interest in using these materials for therapy and health maintenance. Efficacies of the application is critically dependent on the use of genuine materials. For time to time, life-threatening poisoning is found because toxic adulterant or substitute is administered. DNA barcoding provides a definitive means of authentication and for conducting molecular systematics studies. Owing to the reduced cost in DNA authentication, the volume of the DNA barcodes produced for medicinal materials is on the rise and necessitates the development of an integrated DNA database. Description We have developed an integrated DNA barcode multimedia information platform- Medicinal Materials DNA Barcode Database (MMDBD for data retrieval and similarity search. MMDBD contains over 1000 species of medicinal materials listed in the Chinese Pharmacopoeia and American Herbal Pharmacopoeia. MMDBD also contains useful information of the medicinal material, including resources, adulterant information, medical parts, photographs, primers used for obtaining the barcodes and key references. MMDBD can be accessed at http://www.cuhk.edu.hk/icm/mmdbd.htm. Conclusions This work provides a centralized medicinal materials DNA barcode database and bioinformatics tools for data storage, analysis and exchange for promoting the identification of medicinal materials. MMDBD has the largest collection of DNA barcodes of medicinal materials and is a useful resource for researchers in conservation, systematic study, forensic and herbal industry.

  4. Energy efficiency of buildings with phase-change materials

    Directory of Open Access Journals (Sweden)

    Lukić Predrag

    2012-01-01

    Full Text Available The construction of energy efficient buildings using innovative building materials such as phase change materials, in addition to improving indoor comfort, energy savings and costs, can be achieved by increasing their market value. Because of its ability to absorb and release energy at predictable temperatures, phase change materials are effective in controlling and maintaining the thermal environment in the building. The use of phase changing materials, materials stored latent energy storage is an effective form of heat. [Projekat Ministarstva nauke Republike Srbije, br. TR36016: Experimental and theoretical investigation of frames and plates with semi-rigid connections from the view of the second order theory and stability analysis

  5. Thin-film perovskites-ferroelectric materials for integrated optics

    Energy Technology Data Exchange (ETDEWEB)

    Walker, F.J. [Univ. of Tennessee, Knoxville, TN (United States)]|[Oak Ridge National Lab., TN (United States); McKee, R.A. [Oak Ridge National Lab., TN (United States)

    1995-12-31

    Optical guided wave (OGW) devices, based on LiNbO{sub 3} or GaAs. are commercially available products with established markets and applications. While LiNbO{sub 3} presently dominates the commercial applications, there are several drivers for the development of improved electro-optic (EO) materials. If the appropriate crystal quality could be obtained for thin-film BaTiO{sub 3} supported on MgO for example, or for an integrated BaTiO{sub 3}/Mg0 structure on silicon or GaAs, then the optimum OGW device structure might be realized. We report on our results for the growth of optical quality, epitaxial BaTiO{sub 3} and SrTiO{sub 3} on single-crystal MgO substrates using source shuttering molecular beam epitaxy (MBE) techniques. We also discuss how these materials can be integrated onto silicon. Our MBE studies show that, for this important class of perovskite oxides, heteroepitaxy between the perovskites and alkaline earth oxides is dominated by interfacial electrostatics at the first atomic layers. We have been able to demonstrate that a layer-by-layer energy minimization associated with interfacial electrostatics leads to the growth of high quality thin films of these materials. We have fabricated waveguides from these materials, and the optical clarity and loss coefficients have been characterized and found to be comparable to in-diffused waveguide structures typically represented by Ti drifted LiNbO{sub 3}.

  6. Drag material change in hot runner injection molding

    Institute of Scientific and Technical Information of China (English)

    蒋炳炎; 黄伯云

    2001-01-01

    Quick material change is often encountered for the different colors or kinds of polymer in hot runner injecting molding process. Time-costing and incompleteness of material change process often affects the quality and productivity of products. In the practical production, multi-injection or white material as the transition material is often adopted for quick material change. Based on the rheological behavior of the new and the previous plastic melt, the researches on the related problems were carried out. The concept of drag material change was originally presented. The physical and mathematical model on the simultaneous flow process of the new and the previous plastic melt in hot runner were built up, which can well explain the influence of the injection speed, pressure, viscosity difference, temperature and mold structure on the drag material change efficiency. When temperature in different position in the mold was increased and adjusted, the viscosity difference between the two kinds of melt can be controlled. Therefore the material change ability can be greatly improved during the whole material change process, getting rid of more and more difficult changing in the late stage.

  7. Toward an integrative perspective on resistance to change.

    Science.gov (United States)

    Arkowitz, Hal

    2002-02-01

    This article presents an integrative perspective on resistance. The phenomena of resistance can be seen at the behavioral, interpersonal, cognitive, and affective levels. A set of integrative working assumptions is proposed in which resistance reflects meaningful information about clients' conflicts among various aspects of their selves relating to change. In this view, resistance is determined by intrapersonal and interpersonal factors and can occur with or without conscious awareness. Integrative approaches to working with these conflicts are described.

  8. Structural integrity of engineering composite materials: a cracking good yarn.

    Science.gov (United States)

    Beaumont, Peter W R; Soutis, Costas

    2016-07-13

    Predicting precisely where a crack will develop in a material under stress and exactly when in time catastrophic fracture of the component will occur is one the oldest unsolved mysteries in the design and building of large-scale engineering structures. Where human life depends upon engineering ingenuity, the burden of testing to prove a 'fracture safe design' is immense. Fitness considerations for long-life implementation of large composite structures include understanding phenomena such as impact, fatigue, creep and stress corrosion cracking that affect reliability, life expectancy and durability of structure. Structural integrity analysis treats the design, the materials used, and figures out how best components and parts can be joined, and takes service duty into account. However, there are conflicting aims in the complete design process of designing simultaneously for high efficiency and safety assurance throughout an economically viable lifetime with an acceptable level of risk. This article is part of the themed issue 'Multiscale modelling of the structural integrity of composite materials'.

  9. Subscale Water Based Phase Change Material Heat Exchanger Development

    Science.gov (United States)

    Sheth, Rubik; Hansen, Scott

    2016-01-01

    Supplemental heat rejection devices are required in many spacecraft as the radiators are not sized to meet the full heat rejection demand. One means of obtaining additional heat rejection is through the use of phase change material heat exchangers (PCM HX's). PCM HX's utilize phase change to store energy in unfavorable thermal environments (melting) and reject the energy in favorable environments (freezing). Traditionally, wax has been used as a PCM on spacecraft. However, water is an attractive alternative because it is capable of storing about 40% more energy per unit mass due to its higher latent heat of fusion. The significant problem in using water as a PCM is its expansion while freezing, leading to structural integrity concerns when housed in an enclosed heat exchanger volume. Significant investigation and development has taken place over the past five years to understand and overcome the problems associated with water PCM HX's. This paper reports on the final efforts by Johnson Space Center's Thermal Systems Branch to develop a water based PCM HX. The test article developed and reported on is a subscale version of the full-scale water-based PCM HX's constructed by Mezzo Technologies. The subscale unit was designed by applying prior research on freeze front propagation and previous full-scale water PCM HX development. Design modifications to the subscale unit included use of urethane bladder, decreased aspect ratio, perforated protection sheet, and use of additional mid-plates. Testing of the subscale unit was successful and 150 cycles were completed without fail.

  10. Integrated Climate Change Impacts Assessment in California

    Science.gov (United States)

    Cayan, D. R.; Franco, G.; Meyer, R.; Anderson, M.; Bromirski, P. D.

    2014-12-01

    This paper summarizes lessons learned from an ongoing series of climate change assessments for California, conducted by the scientific community and State and local agencies. A series of three Assessments have considered vulnerability and adaptation issues for both managed and natural systems. California's vulnerability is many faceted, arising because of an exceptionally drought prone climate, open coast and large estuary exposure to sea level rise, sensitive ecosystems and complex human footprint and economy. Key elements of the assessments have been a common set of climate and sea-level rise scenarios, based upon IPCC GCM simulations. Regionalized and localized output from GCM projections was provided to research teams investigating water supply, agriculture, coastal resources, ecosystem services, forestry, public health, and energy demand and hydropower generation. The assessment results are helping to investigate the broad range of uncertainty that is inherent in climate projections, and users are becoming better equipped to process an envelope of potential climate and impacts. Some projections suggest that without changes in California's present fresh-water delivery system, serious water shortages would take place, but that technical solutions are possible. Under a warmer climate, wildfire vulnerability is heightened markedly in some areas--estimated increases in burned area by the end of the 21st Century exceed 100% of the historical area burned in much of the forested areas of Northern California Along California coast and estuaries, projected rise in mean sea level will accelerate flooding occurrences, prompting the need for better education and preparedness. Many policymakers and agency personnel in California are factoring in results from the assessments and recognize the need for a sustained assessment process. An ongoing challenge, of course, is to achieve more engagement with a broader community of decision makers, and notably with the private sector.

  11. Integrated safeguards & security for material protection, accounting, and control.

    Energy Technology Data Exchange (ETDEWEB)

    Duran, Felicia Angelica; Cipiti, Benjamin B.

    2009-10-01

    Traditional safeguards and security design for fuel cycle facilities is done separately and after the facility design is near completion. This can result in higher costs due to retrofits and redundant use of data. Future facilities will incorporate safeguards and security early in the design process and integrate the systems to make better use of plant data and strengthen both systems. The purpose of this project was to evaluate the integration of materials control and accounting (MC&A) measurements with physical security design for a nuclear reprocessing plant. Locations throughout the plant where data overlap occurs or where MC&A data could be a benefit were identified. This mapping is presented along with the methodology for including the additional data in existing probabilistic assessments to evaluate safeguards and security systems designs.

  12. Material Protection, Accounting, and Control Technologies (MPACT) Advanced Integration Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Mike [Idaho National Lab. (INL), Idaho Falls, ID (United States); Cipiti, Ben [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Demuth, Scott Francis [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Durkee, Jr., Joe W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Fallgren, Andrew James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Jarman, Ken [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Li, Shelly [Idaho National Lab. (INL), Idaho Falls, ID (United States); Meier, Dave [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Osburn, Laura Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pereira, Candido [Argonne National Lab. (ANL), Argonne, IL (United States); Dasari, Venkateswara Rao [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ticknor, Lawrence O. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Yoo, Tae-Sic [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2017-01-30

    The development of sustainable advanced nuclear fuel cycles is a long-term goal of the Office of Nuclear Energy’s (DOE-NE) Fuel Cycle Technologies program. The Material Protection, Accounting, and Control Technologies (MPACT) campaign is supporting research and development (R&D) of advanced instrumentation, analysis tools, and integration methodologies to meet this goal (Miller, 2015). This advanced R&D is intended to facilitate safeguards and security by design of fuel cycle facilities. The lab-scale demonstration of a virtual facility, distributed test bed, that connects the individual tools being developed at National Laboratories and university research establishments, is a key program milestone for 2020. These tools will consist of instrumentation and devices as well as computer software for modeling, simulation and integration.

  13. Material Protection, Accounting, and Control Technologies (MPACT) Advanced Integration Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    Durkee, Joe W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Cipiti, Ben [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Demuth, Scott Francis [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Fallgren, Andrew James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Jarman, Ken [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Li, Shelly [Argonne National Lab. (ANL), Argonne, IL (United States); Meier, Dave [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Miller, Mike [Argonne National Lab. (ANL), Argonne, IL (United States); Osburn, Laura Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pereira, Candido [Argonne National Lab. (ANL), Argonne, IL (United States); Dasari, Venkateswara Rao [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ticknor, Lawrence O. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Yoo, Tae-Sic [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-09-30

    The development of sustainable advanced nuclear fuel cycles is a long-term goal of the Office of Nuclear Energy’s (DOE-NE) Fuel Cycle Technologies program. The Material Protection, Accounting, and Control Technologies (MPACT) campaign is supporting research and development (R&D) of advanced instrumentation, analysis tools, and integration methodologies to meet this goal (Miller, 2015). This advanced R&D is intended to facilitate safeguards and security by design of fuel cycle facilities. The lab-scale demonstration of a virtual facility, distributed test bed, that connects the individual tools being developed at National Laboratories and university research establishments, is a key program milestone for 2020. These tools will consist of instrumentation and devices as well as computer software for modeling, simulation and integration.

  14. Wafer Fusion for Integration of Semiconductor Materials and Devices

    Energy Technology Data Exchange (ETDEWEB)

    Choquette, K.D.; Geib, K.M.; Hou, H.Q.; Allerman, A.A.; Kravitz, S.; Follstaedt, D.M.; Hindi, J.J.

    1999-05-01

    We have developed a wafer fusion technology to achieve integration of semiconductor materials and heterostructures with widely disparate lattice parameters, electronic properties, and/or optical properties for novel devices not now possible on any one substrate. Using our simple fusion process which uses low temperature (400-600 C) anneals in inert N{sub 2} gas, we have extended the scope of this technology to examine hybrid integration of dissimilar device technologies. As a specific example, we demonstrate wafer bonding vertical cavity surface emitting lasers (VCSELs) to transparent AlGaAs and GaP substrates to fabricate bottom-emitting short wavelength VCSELs. As a baseline fabrication technology applicable to many semiconductor systems, wafer fusion will revolutionize the way we think about possible semiconductor devices, and enable novel device configurations not possible by epitaxial growth.

  15. A New Kind of Shape-stabilized Phase Change Materials

    Institute of Scientific and Technical Information of China (English)

    XIAO Liguang; DING Rui; SUN Hao; WANG Fujun

    2011-01-01

    Based on the lowest melting point and Schroeder's theoretical calculation formula, nanomodified organic composite phase change materials (PCMs) were prepared. The phase transition temperature and the latent heat of the materials were 24 ℃ and 172 J/g, respectively. A new shape-stabilized phase change materials were prepared, using high density polyethylene as supporting material. The PCM kept the shape when temperature was higher than melting point. Thus, it can directly contact with heat transfer media. The structure,morphology and thermal behavior of PCM were analyzed by FTIR, SEM and DSC.

  16. Influence of thermal stress on marginal integrity of restorative materials

    Directory of Open Access Journals (Sweden)

    Maximiliano Sérgio Cenci

    2008-04-01

    Full Text Available The aim of this study was to evaluate the influence of thermal stress on the marginal integrity of restorative materials with different adhesive and thermal properties. Three hundred and sixty Class V cavities were prepared in buccal and lingual surfaces of 180 bovine incisors. Cervical and incisal walls were located in dentin and enamel, respectively. Specimens were restored with resin composite (RC; glass ionomer (GI or amalgam (AM, and randomly assigned to 18 groups (n=20 according to the material, number of cycles (500 or 1,000 cycles and dwell time (30 s or 60 s. Dry and wet specimens served as controls Specimens were immersed in 1% basic fuchsine solution (24 h, sectioned, and microleakage was evaluated under x40 magnification. Data were analyzed by Kruskal-Wallis and Mann-Whitney tests: Thermal cycling regimens increased leakage in all AM restorations (p<0.05 and its effect on RC and GI restorations was only significant when a 60-s dwell time was used (p<0.05. Marginal integrity was more affected in AM restorations under thermal cycling stress, whereas RC and GI ionomer restoration margins were only significantly affected only under longer dwell times.

  17. Generation IV Reactors Integrated Materials Technology Program Plan: Focus on Very High Temperature Reactor Materials

    Energy Technology Data Exchange (ETDEWEB)

    Corwin, William R [ORNL; Burchell, Timothy D [ORNL; Katoh, Yutai [ORNL; McGreevy, Timothy E [ORNL; Nanstad, Randy K [ORNL; Ren, Weiju [ORNL; Snead, Lance Lewis [ORNL; Wilson, Dane F [ORNL

    2008-08-01

    the structural materials needed to ensure their safe and reliable operation. The focus of this document will be the overall range of DOE's structural materials research activities being conducted to support VHTR development. By far, the largest portion of material's R&D supporting VHTR development is that being performed directly as part of the Next-Generation Nuclear Plant (NGNP) Project. Supplementary VHTR materials R&D being performed in the DOE program, including university and international research programs and that being performed under direct contracts with the American Society for Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, will also be described. Specific areas of high-priority materials research that will be needed to deploy the NGNP and provide a basis for subsequent VHTRs are described, including the following: (1) Graphite: (a) Extensive unirradiated materials characterization and assessment of irradiation effects on properties must be performed to qualify new grades of graphite for nuclear service, including thermo-physical and mechanical properties and their changes, statistical variations from billot-to-billot and lot-to-lot, creep, and especially, irradiation creep. (b) Predictive models, as well as codification of the requirements and design methods for graphite core supports, must be developed to provide a basis for licensing. (2) Ceramics: Both fibrous and load-bearing ceramics must be qualified for environmental and radiation service as insulating materials. (3) Ceramic Composites: Carbon-carbon and SiC-SiC composites must be qualified for specialized usage in selected high-temperature components, such as core stabilizers, control rods, and insulating covers and ducting. This will require development of component-specific designs and fabrication processes, materials characterization, assessment of environmental and irradiation effects, and establishment of codes and standards for materials testing and design

  18. Materials integration for high-performance photovoltaics by wafer bonding

    Science.gov (United States)

    Zahler, James Michael

    The fundamental efficiency limit for state of the art triple-junction photovoltaic devices is being approached. By allowing integration of non-lattice-matched materials in monolithic structures, wafer bonding enables novel photovoltaic devices that have a greater number of subcells to improve the discretization of the solar spectrum, thus extending the efficiency limit of the devices. Additionally, wafer bonding enables the integration of non-lattice-matched materials with foreign substrates to confer desirable properties associated with the handle substrate on the solar cell structure, such as reduced mass, increased thermal conductivity, and improved mechanical toughness. This thesis outlines process development and characterization of wafer bonding integration technologies essential for transferring conventional triple-junction solar cell designs to potentially lower cost Ge/Si epitaxial templates. These epitaxial templates consist of a thin film of single-crystal Ge on a Si handle substrate. Additionally, a novel four-junction solar cell design consisting of non-lattice matched subcells of GaInP, GaAs, InGaAsP, and InGaAs based on InP/Si wafer-bonded epitaxial templates is proposed and InP/Si template fabrication and characterization is pursued. In this thesis the detailed-balance theory of the thermodynamic limiting performance of solar cell efficiency is applied to several device designs enabled by wafer bonding and layer exfoliation. The application of the detailed-balance theory to the novel four-junction cell described above shows that operating under 100 suns at 300 K a maximum efficiency of 54.9% is achievable with subcell bandgaps of 1.90, 1.42, 1.02, and 0.60 eV, a material combination achievable by integrating two wide-bandgap subcells lattice matched to GaAs and two narrow-bandgap subcells lattice matched to InP. Wafer bonding and layer transfer processes with sufficient quality to enable subsequent material characterization are demonstrated for both

  19. INTEGRATED DEVELOPMENT OF CHEMICAL TEACHING MATERIALS ON MATERIAL BASED THERMOCHEMICAL SOFT SKILLS FOR VOCATIONAL STUDENTS

    Directory of Open Access Journals (Sweden)

    S. D. Purnawan

    2015-11-01

    Full Text Available Business and industrial field need workers who have not only good academic achievement but also the ability of hard skills and soft skills.  In order to prepare students who have a good academic skills, hard skills, soft skills it has to be done in all subjects including chemistry expertise to integrate the competencies of Motorcycle Engineering.  The research design uses One Group Pretest Posttest Design imposed on students in class XI SMK 1 Kedung TSM. Validator assessment results indicate that teaching materials developed very feasible for use in learning chemistry.  The result show that the learning device by using the integrated chemistry materials can increase students understanding of the thermo chemistry material with the acquisition of N-gain is at 0.63 or in the medium category.  Group of high-achieving students have the score of N-gain of 0.65, while the medium-achieving students get 0.63 and low-achieving students get 0.61, all have medium category.  Percentage  of students who passes the mastery learning  if mastery learning (KKM > 75 or reach 87 %.  The percentage of students’ soft skills in at least good criteria is at 87.10 %.  Students gave positive responses  90.71 % towards the learning material that is developed.

  20. The material politics of waste disposal - decentralization and integrated systems

    Directory of Open Access Journals (Sweden)

    Penelope Harvey

    2012-12-01

    Full Text Available This article and the previous «Convergence and divergence between the local and regional state around solid waste management. An unresolved problem in the Sacred Valley» from Teresa Tupayachi are published as complementary accounts on the management of solid waste in the Vilcanota Valley in Cusco. Penelope Harvey and Teresa Tupayachi worked together on this theme. The present article explores how discontinuities across diverse instances of the state are experienced and understood. Drawing from an ethnographic study of the Vilcanota Valley in Cusco, the article looks at the material politics of waste disposal in neoliberal times. Faced with the problem of how to dispose of solid waste, people from Cusco experience a lack of institutional responsibility and call for a stronger state presence. The article describes the efforts by technical experts to design integrated waste management systems that maximise the potential for re-cycling, minimise toxic contamination, and turn ‘rubbish’ into the altogether more economically lively category of ‘solid waste’. However while the financialization of waste might appear to offer an indisputable public good, efforts to instigate a viable waste disposal business in a decentralizing political space elicit deep social tensions and contradictions. The social discontinuities that decentralization supports disrupt ambitions for integrated solutions as local actors resist top-down models and look not just for alternative solutions, but alternative ways of framing the problem of urban waste, and by extension their relationship to the state.

  1. An Integrated Analysis of Changes in Water Stress in Europe

    DEFF Research Database (Denmark)

    Henrichs, T.; Lehner, B.; Alcamo, J.

    2002-01-01

    that today high water stress exists in one-fifth of European river basin area. Under a scenario projection, increases in water use throughout Eastern Europe are accompanied by decreases in water availability in most of Southern Europe--combining these trends leads to a marked increase in water stress......Future changes in water availability with climate change and changes in water use due to socio-economic development are to occur in parallel. In an integrated analysis we bring together these aspects of global change in a consistent manner, and analyse the water stress situation in Europe. We find...

  2. Constraints on the Adiabatic Temperature Change in Magnetocaloric Materials

    DEFF Research Database (Denmark)

    Nielsen, Kaspar Kirstein; Bahl, Christian Robert Haffenden; Smith, Anders

    2010-01-01

    The thermodynamics of the magnetocaloric effect implies constraints on the allowed variation in the adiabatic temperature change for a magnetocaloric material. An inequality for the derivative of the adiabatic temperature change with respect to temperature is derived for both first- and second...

  3. Phase change materials and the perception of wetness

    NARCIS (Netherlands)

    Bergmann Tiest, W.M.; Kosters, N.D.; Kappers, A.M.L.; Daanen, H.A.M.

    2012-01-01

    Phase change materials (PCMs) are increasingly incorporated in textiles in order to serve as a thermal buffer when humans change from a hot to a cold environment and the reverse. Due to the absence of wetness sensors in the skin, cooling of the skin may be perceived as a sensation of wetness instead

  4. Temperature reduction due to the application of phase change materials

    Energy Technology Data Exchange (ETDEWEB)

    Voelker, Conrad; Kornadt, Oliver [Department of Building Physics, Bauhaus-University Weimar, Coudraystrasse 11a, 99423 Weimar (Germany); Ostry, Milan [Faculty of Civil Engineering, Brno University of Technology, Department of Building Structures, Veveri 95, 602 00 Brno (Czech Republic)

    2008-07-01

    Overheating is a major problem in many modern buildings due to the utilization of lightweight constructions with low heat storing capacity. A possible answer to this problem is the emplacement of phase change materials (PCM), thereby increasing the thermal mass of a building. These materials change their state of aggregation within a defined temperature range. Useful PCM for buildings show a phase transition from solid to liquid and vice versa. The thermal mass of the materials is increased by the latent heat. A modified gypsum plaster and a salt mixture were chosen as two materials for the study of their impact on room temperature reduction. For realistic investigations, test rooms were erected where measurements were carried out under different conditions such as temporary air change, alternate internal heat gains or clouding. The experimental data was finally reproduced by dint of a mathematical model. (author)

  5. Thermal energy storage using phase change materials fundamentals and applications

    CERN Document Server

    Fleischer, Amy S

    2015-01-01

    This book presents a comprehensive introduction to the use of solid‐liquid phase change materials to store significant amounts of energy in the latent heat of fusion. The proper selection of materials for different applications is covered in detail, as is the use of high conductivity additives to enhance thermal diffusivity. Dr. Fleischer explores how applications of PCMS have expanded over the past 10 years to include the development of high efficiency building materials to reduce heating and cooling needs, smart material design for clothing, portable electronic systems thermal management, solar thermal power plant design and many others. Additional future research directions and challenges are also discussed.

  6. Vibration damping and heat transfer using material phase changes

    Science.gov (United States)

    Kloucek, Petr (Inventor); Reynolds, Daniel R. (Inventor)

    2009-01-01

    A method and apparatus wherein phase changes in a material can dampen vibrational energy, dampen noise and facilitate heat transfer. One embodiment includes a method for damping vibrational energy in a body. The method comprises attaching a material to the body, wherein the material comprises a substrate, a shape memory alloy layer, and a plurality of temperature change elements. The method further comprises sensing vibrations in the body. In addition, the method comprises indicating to at least a portion of the temperature change elements to provide a temperature change in the shape memory alloy layer, wherein the temperature change is sufficient to provide a phase change in at least a portion of the shape memory alloy layer, and further wherein the phase change consumes a sufficient amount of kinetic energy to dampen at least a portion of the vibrational energy in the body. In other embodiments, the shape memory alloy layer is a thin film. Additional embodiments include a sensor connected to the material.

  7. A 63 K phase change unit integrating with pulse tube cryocoolers

    Science.gov (United States)

    Chunhui, Kong; Liubiao, Chen; Sixue, Liu; Yuan, Zhou; Junjie, Wang

    2017-02-01

    This article presents the design and computer model results of an integrated cooler system which consists of a single stage pulse tube cryocooler integrated with a small amount of a phase change material. A cryogenic thermal switch was used to thermally connect the phase change unit to the cold end of the cryocooler. During heat load operation, the cryogenic thermal switch is turned off to avoid vibrations. The phase change unit absorbs heat loads by melting a substance in a constant pressure-temperature-volume process. Once the substance has been melted, the cryogenic thermal turned on, the cryocooler can then refreeze the material. Advantages of this type of cooler are no vibrations during sensor operations; the ability to absorb increased heat loads; potentially longer system lifetime; and a lower mass, volume and cost. A numerical model was constructed from derived thermodynamic relationships for the cooling/heating and freezing/melting processes.

  8. Changing Donor Funding and the Challenges of Integrated HIV Treatment.

    Science.gov (United States)

    Nattrass, Nicoli; Hodes, Rebecca; Cluver, Lucie

    2016-07-01

    Donor financing for HIV prevention and treatment has shifted from supporting disease-specific ("vertical") programs to health systems strengthening ("horizontal") programs intended to integrate all aspects of care. We examine the consequences of shifting resources from three perspectives: first, through a broad analysis of the changing policy context of health care financing; second, through an account of changing priorities for HIV treatment in South Africa; and third, through a description of some clinical consequences that the authors observed in a research study examining adherence to antiretroviral therapy (ART) and sexual health among adolescents. We note that AIDS responses are neither completely vertical nor horizontal but rather increasingly diagonal, as disease-specific protocols operate alongside integrated supply chain management, human resource development, and preventive screening. We conclude that health care programs are better conceived of as networks of policies requiring different degrees of integration into communities.

  9. Integrating Biopsychosocial Intervention Research in a Changing Health Care Landscape

    Science.gov (United States)

    Ell, Kathleen; Oh, Hyunsung; Wu, Shinyi

    2016-01-01

    Objective: Safety net care systems are experiencing unprecedented change from the "Affordable Care Act," Patient-Centered Medical Home (PCMH) uptake, health information technology application, and growing of mental health care integration within primary care. This article provides a review of previous and current efforts in which social…

  10. Differentiation and Integration: Guiding Principles for Analyzing Cognitive Change

    Science.gov (United States)

    Siegler, Robert S.; Chen, Zhe

    2008-01-01

    Differentiation and integration played large roles within classic developmental theories but have been relegated to obscurity within contemporary theories. However, they may have a useful role to play in modern theories as well, if conceptualized as guiding principles for analyzing change rather than as real-time mechanisms. In the present study,…

  11. Social Integration and Health Behavioral Change in San Luis, Honduras

    Science.gov (United States)

    McQuestion, Michael J.; Calle, Ana Quijano; Drasbek, Christopher; Harkins, Thomas; Sagastume, Lourdes J.

    2010-01-01

    This study explores the effects of social integration on behavioral change in the course of an intensive, community-based public health intervention. The intervention trained volunteers and mobilized local organizations to promote 16 key family health practices in rural San Luis, Honduras, during 2004 to 2006. A mixed methods approach is used.…

  12. National Call for Organizational Change from Sheltered to Integrated Employment

    Science.gov (United States)

    Rogan, Patricia; Rinne, Susan

    2011-01-01

    Our purpose in this article is to contend that organizational change from sheltered to integrated employment is not only possible but necessary, and a federal Employment First agenda must be advanced. Findings are reported from interviews with senior managers from 10 organizations that have shifted their service delivery to community employment,…

  13. Climate change and coastal vulnerability assessment: Scenarios for integrated assessment

    Science.gov (United States)

    Nicholls, R.J.; Wong, P.P.; Burkett, V.; Woodroffe, C.D.; Hay, J.

    2008-01-01

    Coastal vulnerability assessments still focus mainly on sea-level rise, with less attention paid to other dimensions of climate change. The influence of non-climatic environmental change or socio-economic change is even less considered, and is often completely ignored. Given that the profound coastal changes of the twentieth century are likely to continue through the twenty-first century, this is a major omission, which may overstate the importance of climate change, and may also miss significant interactions of climate change with other non-climate drivers. To better support climate and coastal management policy development, more integrated assessments of climatic change in coastal areas are required, including the significant non-climatic changes. This paper explores the development of relevant climate and non-climate drivers, with an emphasis on the non-climate drivers. While these issues are applicable within any scenario framework, our ideas are illustrated using the widely used SRES scenarios, with both impacts and adaptation being considered. Importantly, scenario development is a process, and the assumptions that are made about future conditions concerning the coast need to be explicit, transparent and open to scientific debate concerning their realism and likelihood. These issues are generic across other sectors. ?? Integrated Research System for Sustainability Science and Springer 2008.

  14. Confined crystals of the smallest phase-change material.

    Science.gov (United States)

    Giusca, Cristina E; Stolojan, Vlad; Sloan, Jeremy; Börrnert, Felix; Shiozawa, Hidetsugu; Sader, Kasim; Rümmeli, Mark H; Büchner, Bernd; Silva, S Ravi P

    2013-09-11

    The demand for high-density memory in tandem with limitations imposed by the minimum feature size of current storage devices has created a need for new materials that can store information in smaller volumes than currently possible. Successfully employed in commercial optical data storage products, phase-change materials, that can reversibly and rapidly change from an amorphous phase to a crystalline phase when subject to heating or cooling have been identified for the development of the next generation electronic memories. There are limitations to the miniaturization of these devices due to current synthesis and theoretical considerations that place a lower limit of 2 nm on the minimum bit size, below which the material does not transform in the structural phase. We show here that by using carbon nanotubes of less than 2 nm diameter as templates phase-change nanowires confined to their smallest conceivable scale are obtained. Contrary to previous experimental evidence and theoretical expectations, the nanowires are found to crystallize at this scale and display amorphous-to-crystalline phase changes, fulfilling an important prerequisite of a memory element. We show evidence for the smallest phase-change material, extending thus the size limit to explore phase-change memory devices at extreme scales.

  15. Optimization of a phase change material wallboard for building use

    Energy Technology Data Exchange (ETDEWEB)

    Kuznik, Frederic; Virgone, Joseph [Thermal Sciences Center of Lyon, CNRS, UMR 5008, INSA de Lyon, Universite Lyon 1, Bat Freyssinet, 40 Rue des Arts, 69621 Villeurbanne Cedex (France); Noel, Jean [Free-lance Scientific Software Developer, 15 Place Carnot, 69002 Lyon (France)

    2008-08-15

    In construction, the use of phase change materials (PCM) allows the storage/release of energy from the solar radiation and/or internal loads. The application of such materials for lightweight construction (e.g., a wood house) makes it possible to improve thermal comfort and reduce energy consumption. A wallboard composed of a new PCM material is investigated in this paper to enhance the thermal behavior of a lightweight internal partition wall. The paper focuses on the optimization of phase change material thickness. The in-house software CODYMUR is used to optimize the PCM wallboard by the means of numerical simulations. The results show that an optimal PCM thickness exists. The optimal PCM thickness value is then calculated for use in construction. (author)

  16. Parametric Integral Equations Systems Method In Solving Unsteady Heat Transfer Problems For Laser Heated Materials

    Directory of Open Access Journals (Sweden)

    Sawicki Dominik

    2015-09-01

    Full Text Available One of the most popular applications of high power lasers is heating of the surface layer of a material, in order to change its properties. Numerical methods allow an easy and fast way to simulate the heating process inside of the material. The most popular numerical methods FEM and BEM, used to simulate this kind of processes have one fundamental defect, which is the necessity of discretization of the boundary or the domain. An alternative to avoid the mentioned problem are parametric integral equations systems (PIES, which do not require classical discretization of the boundary and the domain while being numerically solved. PIES method was previously used with success to solve steady-state problems, as well as transient heat transfer problems. The purpose of this paper is to test the efficacy of the PIES method with time discretization in solving problem of laser heating of a material, with different pulse shape approximation functions.

  17. Lightweight Phase-Change Material For Solar Power

    Science.gov (United States)

    Stark, Philip

    1993-01-01

    Lightweight panels containing phase-change materials developed for use as heat-storage elements of compact, lightweight, advanced solar dynamic power system. During high insolation, heat stored in panels via latent heat of fusion of phase-change material; during low insolation, heat withdrawn from panels. Storage elements consist mainly of porous carbon-fiber structures imbued with germanium. Developed for use aboard space station in orbit around Earth, also adapted to lightweight, compact, portable solar-power systems for use on Earth.

  18. Preparation of Firefighting Hood for Cooling for Phase Change Materials

    Directory of Open Access Journals (Sweden)

    Shu Hwa Lin

    2016-10-01

    Full Text Available There are two types of Phase Change Materials (PCMs which have been developed and adopted in textiles: heat (energy released and cool (energy absorbed. This paper discusses current PCM applications and explores future applications in firefighting gear. Phase change materials are considered latent heat storage units because as they change phase from solid to liquid, liquid to gas and vice versa, energy in the form of heat is absorbed or released. The goal of PCM textiles is to create reusable energy to maintain body temperature, as well as to optimize the performance of protective wear such as hoods. When the wearer’s body temperature increases or decreases, the PCMs applied to the fabric will change state helping to regulate the wearer’s body temperature by providing warmth or cooling. Maintaining a stable body temperature can improve working conditions and comfort.

  19. Preparation of Firefighting Hood for Cooling For Phase Change Materials

    Directory of Open Access Journals (Sweden)

    Shu Hwa Lin

    2016-10-01

    Full Text Available There are two types of Phase Change Materials (PCMs which have been developed and adopted in textiles: heat (energy released and cool (energy absorbed. This paper discusses current PCM applications and explores future applications in firefighting gear. Phase change materials are considered latent heat storage units because as they change phase from solid to liquid, liquid to gas and vice versa, energy in the form of heat is absorbed or released. The goal of PCM textiles is to create reusable energy to maintain body temperature, as well as to optimize the performance of protective wear such as hoods. When the wearer’s body temperature increases or decreases, the PCMs applied to the fabric will change state helping to regulate the wearer’s body temperature by providing warmth or cooling. Maintaining a stable body temperature can improve working conditions and comfort.

  20. The socio-materiality of designing organizational change

    DEFF Research Database (Denmark)

    Stang Våland, Marianne; Georg, Susse

    2014-01-01

    Purpose – The purpose of this paper is to examine the managerial implications of adopting a design attitude to organizational change. Design/methodology/approach – Based on an ethnographic study of a merger, the paper investigates the intricate interplay between architectural design...... and organizational change in the context of physically relocating an organization to a new office building. Emphasis is given to the socio-materiality of this double design process. Findings – The data suggests that taking a design attitude toward managing organizational change can allow different actors...... to participate in organizational design processes, releasing management from its traditional role as the keeper of the design solution. Research limitations/implications – Although based on a single case, the paper provides insights into the socio-materiality of organizational change that is relevant in other...

  1. 75 FR 69078 - Workshop To Review Draft Materials for the Lead (Pb) Integrated Science Assessment (ISA)

    Science.gov (United States)

    2010-11-10

    ... AGENCY Workshop To Review Draft Materials for the Lead (Pb) Integrated Science Assessment (ISA) AGENCY... a workshop to evaluate initial draft materials for the Pb Integrated Science Assessment (ISA) is... the scientific content of initial draft materials or sections for the draft ISA. Workshop...

  2. Integrated Performance Testing Workshop - Supplemental Materials (Scripts and Procedures)

    Energy Technology Data Exchange (ETDEWEB)

    Baum, Gregory A.

    2014-02-01

    A variety of performance tests are described relating to: Material Transfers; Emergency Evacuation; Alarm Response Assessment; and an Enhanced Limited Scope Performance Test (ELSPT). Procedures are given for: nuclear material physical inventory and discrepancy; material transfers; and emergency evacuation.

  3. Thermal Performance of Microencapsulated Phase Change Material Survey

    Science.gov (United States)

    2008-03-01

    ER D C TR -0 8 -4 Basic Research/Military Construction Thermal Performance of Microencapsulated Phase Change Material Slurry Jorge L...distribution is unlimited. Basic Research/Military Construction ERDC TR-08-4 March 2008 Thermal Performance of Microencapsulated Phase Change... microencapsulated PCM (MPCM) slurries is enhanced significantly, even when using low volume fractions. MPCM slurries have potential to decrease costs and improve

  4. Thermal Performance of Microencapsulated Phase Change Material Slurry

    Science.gov (United States)

    2008-03-01

    ER D C TR -0 8 -4 Basic Research/Military Construction Thermal Performance of Microencapsulated Phase Change Material Slurry Jorge L...distribution is unlimited. Basic Research/Military Construction ERDC TR-08-4 March 2008 Thermal Performance of Microencapsulated Phase Change... microencapsulated PCM (MPCM) slurries is enhanced significantly, even when using low volume fractions. MPCM slurries have potential to decrease costs and improve

  5. Multimedia integration of cartographic source materials for researching and presenting phenomena from economic history

    Science.gov (United States)

    Lorek, Dariusz

    2016-12-01

    The article presents a framework for integrating historical sources with elements of the geographical space recorded in unique cartographic materials. The aim of the project was to elaborate a method of integrating spatial data sources that would facilitate studying and presenting the phenomena of economic history. The proposed methodology for multimedia integration of old materials made it possible to demonstrate the successive stages of the transformation which was characteristic of the 19th-century space. The point of reference for this process of integrating information was topographic maps from the first half of the 19th century, while the research area comprised the castle complex in Kórnik together with the small town - the pre-industrial landscape in Wielkopolska (Greater Poland). On the basis of map and plan transformation, graphic processing of the scans of old drawings, texture mapping of the facades of historic buildings, and a 360° panorama, the source material collected was integrated. The final product was a few-minute-long video, composed of nine sequences. It captures the changing form of the castle building together with its facades, the castle park, and its further topographic and urban surroundings, since the beginning of the 19th century till the present day. For a topographic map sheet dating back to the first half of the 19th century, in which the hachuring method had been used to present land relief, a terrain model was generated. The transition from parallel to bird's-eye-view perspective served to demonstrate the distinctive character of the pre-industrial landscape.

  6. Integrated Decision Support for Global Environmental Change Adaptation

    Science.gov (United States)

    Kumar, S.; Cantrell, S.; Higgins, G. J.; Marshall, J.; VanWijngaarden, F.

    2011-12-01

    Environmental changes are happening now that has caused concern in many parts of the world; particularly vulnerable are the countries and communities with limited resources and with natural environments that are more susceptible to climate change impacts. Global leaders are concerned about the observed phenomena and events such as Amazon deforestation, shifting monsoon patterns affecting agriculture in the mountain slopes of Peru, floods in Pakistan, water shortages in Middle East, droughts impacting water supplies and wildlife migration in Africa, and sea level rise impacts on low lying coastal communities in Bangladesh. These environmental changes are likely to get exacerbated as the temperatures rise, the weather and climate patterns change, and sea level rise continues. Large populations and billions of dollars of infrastructure could be affected. At Northrop Grumman, we have developed an integrated decision support framework for providing necessary information to stakeholders and planners to adapt to the impacts of climate variability and change at the regional and local levels. This integrated approach takes into account assimilation and exploitation of large and disparate weather and climate data sets, regional downscaling (dynamic and statistical), uncertainty quantification and reduction, and a synthesis of scientific data with demographic and economic data to generate actionable information for the stakeholders and decision makers. Utilizing a flexible service oriented architecture and state-of-the-art visualization techniques, this information can be delivered via tailored GIS portals to meet diverse set of user needs and expectations. This integrated approach can be applied to regional and local risk assessments, predictions and decadal projections, and proactive adaptation planning for vulnerable communities. In this paper we will describe this comprehensive decision support approach with selected applications and case studies to illustrate how this

  7. Subthreshold electrical transport in amorphous phase-change materials

    Science.gov (United States)

    Le Gallo, Manuel; Kaes, Matthias; Sebastian, Abu; Krebs, Daniel

    2015-09-01

    Chalcogenide-based phase-change materials play a prominent role in information technology. In spite of decades of research, the details of electrical transport in these materials are still debated. In this article, we present a unified model based on multiple-trapping transport together with 3D Poole-Frenkel emission from a two-center Coulomb potential. With this model, we are able to explain electrical transport both in as-deposited phase-change material thin films, similar to experimental conditions in early work dating back to the 1970s, and in melt-quenched phase-change materials in nanometer-scale phase-change memory devices typically used in recent studies. Experimental measurements on two widely different device platforms show remarkable agreement with the proposed mechanism over a wide range of temperatures and electric fields. In addition, the proposed model is able to seamlessly capture the temporal evolution of the transport properties of the melt-quenched phase upon structural relaxation.

  8. Phase change thermal control materials, method and apparatus

    Science.gov (United States)

    Buckley, Theresa M. (Inventor)

    2001-01-01

    An apparatus and method for metabolic cooling and insulation of a user in a cold environment. In its preferred embodiment the apparatus is a highly flexible composite material having a flexible matrix containing a phase change thermal storage material. The apparatus can be made to heat or cool the body or to act as a thermal buffer to protect the wearer from changing environmental conditions. The apparatus may also include an external thermal insulation layer and/or an internal thermal control layer to regulate the rate of heat exchange between the composite and the skin of the wearer. Other embodiments of the apparatus also provide 1) a path for evaporation or direct absorption of perspiration from the skin of the wearer for improved comfort and thermal control, 2) heat conductive pathways within the material for thermal equalization, 3) surface treatments for improved absorption or rejection of heat by the material, and 4) means for quickly regenerating the thermal storage capacity for reuse of the material. Applications of the composite materials are also described which take advantage of the composite's thermal characteristics. The examples described include a diver's wet suit, ski boot liners, thermal socks, gloves and a face mask for cold weather activities, and a metabolic heating or cooling blanket useful for treating hypothermia or fever patients in a medical setting and therapeutic heating or cooling orthopedic joint supports.

  9. Development of Latent Heat Storage Phase Change Material Containing Plaster

    Directory of Open Access Journals (Sweden)

    Diana BAJARE

    2016-05-01

    Full Text Available This paper reviews the development of latent heat storage Phase Change Material (PCM containing plaster as in passive application. Due to the phase change, these materials can store higher amounts of thermal energy than traditional building materials and can be used to add thermal inertia to lightweight constructions. It was shown that the use of PCMs have advantages stabilizing the room temperature variations during summer days, provided sufficient night ventilation is allowed. Another advantage of PCM usage is stabilized indoor temperature on the heating season. The goal of this study is to develop cement and lime based plaster containing microencapsulated PCM. The plaster is expected to be used for passive indoor applications and enhance the thermal properties of building envelope. The plaster was investigated under Scanning Electron Microscope and the mechanical, physical and thermal properties of created plaster samples were determined.

  10. Round-Robin Test of Paraffin Phase-Change Material

    Science.gov (United States)

    Vidi, S.; Mehling, H.; Hemberger, F.; Haussmann, Th.; Laube, A.

    2015-11-01

    A round-robin test between three institutes was performed on a paraffin phase-change material (PCM) in the context of the German quality association for phase-change materials. The aim of the quality association is to define quality and test specifications for PCMs and to award certificates for successfully tested materials. To ensure the reproducibility and comparability of the measurements performed at different institutes using different measuring methods, a round-robin test was performed. The sample was unknown. The four methods used by the three participating institutes in the round-robin test were differential scanning calorimetry, Calvet calorimetry and three-layer calorimetry. Additionally, T-history measurements were made. The aim of the measurements was the determination of the enthalpy as a function of temperature. The results achieved following defined test specifications are in excellent agreement.

  11. Integrating climate change into agricultural research for development in Africa

    Energy Technology Data Exchange (ETDEWEB)

    Chambwera, Muyeye; Anderson, Simon

    2011-09-15

    African agriculture is already struggling to meet increasing demand for food. Climate change, which will alter agroecological conditions and looks set to arrest and decrease agricultural yields on the continent, will make it even harder to achieve food security. Boosting agricultural productivity in Africa, especially in the face of climate change, cannot be achieved without the benefits of cutting edge science. Advances in technology development and transfer, capacity building and policy research must be harnessed by developing and disseminating relevant strategies and technologies, and improving policy environments. The European Initiative for Agricultural Research for Development (EIARD), which facilitates and coordinates European policy and support for agricultural research for development, must integrate climate change into its activities and ensure that agricultural research for development and climate change adaptation are not disjointed. This demands a more strategic and coordinated approach from the initiative — one that reflects African realities, responds to African priorities for adaptation and development, and makes the best use of limited resources.

  12. An Integrated, Probabilistic Framework for Requirement Change Impact Analysis

    Directory of Open Access Journals (Sweden)

    Simon Lock

    1999-05-01

    Full Text Available Impact analysis is an essential part of change management. Without adequate analysis it is not possible to confidently determine the extent, complexity and cost of proposed changes to a software system. This diminishes the ability of a developer or maintainer to make informed decisions regarding the inclusion or rejection of proposed changes. The lack of coherent impact analysis can also hinder the process of ensuring that all system components affected by a change are updated. The abstract nature of requirement level entities has meant that current impact analysis techniques have focused largely on design and code level artifacts. This paper proposes a novel approach which integrates traditional impact analysis with experience based techniques to extend current approaches to support requirement level impact analysis. Central to this approach is the use of probability to assist in the combination and presentation of predicted impact propagation paths. An Auto Teller Machine (ATM example is used to illustrate the approach.

  13. Production integrated nondestructive testing of composite materials and material compounds – an overview

    Science.gov (United States)

    Straß, B.; Conrad, C.; Wolter, B.

    2017-03-01

    Composite materials and material compounds are of increasing importance, because of the steadily rising relevance of resource saving lightweight constructions. Quality assurance with appropriate Nondestructive Testing (NDT) methods is a key aspect for reliable and efficient production. Quality changes have to be detected already in the manufacturing flow in order to take adequate corrective actions. For materials and compounds the classical NDT methods for defectoscopy, like X-ray and Ultrasound (US) are still predominant. Nevertheless, meanwhile fast, contactless NDT methods, like air-borne ultrasound, dynamic thermography and special Eddy-Current techniques are available in order to detect cracks, voids, pores and delaminations but also for characterizing fiber content, distribution and alignment. In Metal-Matrix Composites US back-scattering can be used for this purpose. US run-time measurements allow the detection of thermal stresses at the metal-matrix interface. Another important area is the necessity for NDT in joining. To achieve an optimum material utilization and product safety as well as the best possible production efficiency, there is a need for NDT methods for in-line inspection of the joint quality while joining or immediately afterwards. For this purpose EMAT (Electromagnetic Acoustic Transducer) technique or Acoustic Emission testing can be used.

  14. Effects on electrochemical performances for host material caused by structure change of modifying material.

    Science.gov (United States)

    Zhang, Yantao; Zhou, Enlou; Song, Dawei; Shi, Xixi; Wang, Xiaoqing; Guo, Jian; Zhang, Lianqi

    2014-09-01

    High ionic conductive lithium niobium oxides were selected as the modifying material to investigate the effects on the electrochemical performances for host material LiNi1/3Co1/3Mn1/3O2 caused by the structure change of the modifying material at various calcination temperatures and modifying amounts. X-ray diffraction (XRD) studies revealed that the structure of the modifying material was single LiNbO3 phase after being calcined at 500 °C and changed to LiNbO3-Li3NbO4 mixture phases at 600 and 700 °C, and further changed to single Li3NbO4 phase at 800 °C. Electrochemical tests displayed that both LiNbO3 and Li3NbO4 phases of modifying material could contribute to the improvement of the cycle performances for the host material, but the improvement degree of Li3NbO4 phase was more evident. The cycle performances and high rate performances of the modified host material (calcined at 700 °C) electrodes were improved with the right modifying amount.

  15. Integrated Assessment and the Relation Between Land-Use Change and Climate Change

    Science.gov (United States)

    Dale, V. H.

    1994-10-07

    Integrated assessment is an approach that is useful in evaluating the consequences of global climate change. Understanding the consequences requires knowledge of the relationship between land-use change and climate change. Methodologies for assessing the contribution of land-use change to atmospheric CO{sub 2} concentrations are considered with reference to a particular case study area: south and southeast Asia. The use of models to evaluate the consequences of climate change on forests must also consider an assessment approach. Each of these points is discussed in the following four sections.

  16. Integrated assessment and the relation between land-use change and climate change

    Energy Technology Data Exchange (ETDEWEB)

    Dale, V.H.

    1994-10-07

    Integrated assessment is an approach that is useful in evaluating the consequences of global climate change. Understanding the consequences requires knowledge of the relationship between land-use change and climate change. Methodologies for assessing the contribution of land-use change to atmospheric CO{sub 2} concentrations are considered with reference to a particular case study area: south and southeast Asia. The use of models to evaluate the consequences of climate change on forests must also consider an assessment approach. Each of these points is discussed in the following four sections.

  17. Effects of solar UV and climate change on materials.

    Science.gov (United States)

    Andrady, A L; Hamid, H; Torikai, A

    2011-02-01

    Increased solar ultraviolet radiation (UV) reaches the surface of the Earth as a consequence of a depleted stratospheric ozone layer and changes in factors such as cloud cover, land-use patterns and aerosols. Climate change is expected to result in a 1.1-6.4 °C increase in average temperature by the end of this century, depending on location. Increased levels of UV radiation, especially at high ambient temperatures, are well-known to accelerate the degradation of plastics, rubber and wood materials, thereby reducing their useful lifetimes in outdoor applications. Plastics used routinely outdoors are generally light-stabilized using chemical additives to ensure their useful lifetimes. Wood products are coated for resistance to UV radiation, since photodamage results in enhanced water-susceptibility and their consequent biodegradation under outdoor exposure. The increased damage to materials due to an increased UV-B (280-315 nm) component in solar radiation reaching the Earth likely can be countered using light-stabilization technologies, surface coatings or, in most instances, by substituting the materials in question with greater UV radiation-resistant materials. However, even if these options could be used with all common materials affected, they will invariably result in higher costs. Reliable estimates of the incremental costs involved depend on the anticipated damage and the effectiveness of mitigation strategies employed. We summarize and assess recent findings on light-induced damage to plastic materials, including wood-plastics composites and nanocomposites. The combined effect of increased UV-B radiation and ambient temperature is of special interest, since these two factors represent particularly harsh environmental conditions for most materials. Advances in approaches to light stabilization of materials are also assessed.

  18. Phase-change material as a thermal storage media

    Energy Technology Data Exchange (ETDEWEB)

    El Chazly, Nihad M; Khattab, Nagwa M [Dokki, Cairo (Egypt)

    2000-07-01

    Heat storage based on the sensible heating of media such as water, rock and earth represent the first generation of solar energy storage subsystems and technology for their utilization. However, recently the heat storage based on the latent heat associated with a change in phase of a material offers many advantages over sensible heat storage. The most important characteristic of such a subsystem is its a sufficient storage capacity. An idealized model visualizing a thermal capacitor using a phase change material is constructed and subjected to simulated solar system environmental conditions. The proposed model is of a flat plate geometry consisting of two panels compartments forming the body of the capacitor containing the paraffin, leaving at their inner surfaces a thin passage allowing the water flow. The whole structure was assumed to be insulated to minimize heat loss. An analysis of the model is conducted using Goodman technique to generate data about the temperature distribution, the melt thickness, and the heat stored in the PCM under conditions of: ( i ) constant mass flow rate tests for various water inlet temperatures and ( ii ) constant water inlet temperature for various mass flow rate. A FORTRAN computer program was constructed to perform the analysis. It was found the water outlet temperature increases with time until it becomes nearly equals to the inlet temperature. Increasing the mass flow rate for a given inlet temperature, decreases the time required for outlet temperature to reach a given value. Increasing inlet temperature for a given mass flow rate gives a very rapid decrease in the time required for the outlet water temperature to reach a given value. Instantaneous rate of heat storage was determined from the inlet-to- exit temperature differential and measured flow rate. This rate was then integrated numerically to determine the cumulative total energy stored as a function of time. It was found that the instantaneous rate of heat storage

  19. Multiscale paradigms in integrated computational materials science and engineering materials theory, modeling, and simulation for predictive design

    CERN Document Server

    Runge, Keith; Muralidharan, Krishna

    2016-01-01

    This book presents cutting-edge concepts, paradigms, and research highlights in the field of computational materials science and engineering, and provides a fresh, up-to-date perspective on solving present and future materials challenges. The chapters are written by not only pioneers in the fields of computational materials chemistry and materials science, but also experts in multi-scale modeling and simulation as applied to materials engineering. Pedagogical introductions to the different topics and continuity between the chapters are provided to ensure the appeal to a broad audience and to address the applicability of integrated computational materials science and engineering for solving real-world problems.

  20. The Partnership between Project Management and Organizational Change: Integrating Change Management with Change Leadership

    Science.gov (United States)

    Griffith-Cooper, Barber; King, Karyl

    2007-01-01

    The nature of project management is change. Even though all knowledge areas in the Project Management Body of Knowledge (PMBOK) are rooted in controlling change, none of these areas specifically addresses the human elements of change. There is a significant distinction between directly controlling change relative to the nonhuman aspects of a…

  1. Toward an Evolutive and Tightly Integrated Information System for Nuclear Materials Management

    Energy Technology Data Exchange (ETDEWEB)

    Dessoude, O. [Euriware (Areva Group), 25 avenue de Tourville, Equeurdreville, 50100 (France)

    2009-06-15

    From a nuclear materials management standpoint, spent-fuel recycling is considered a very challenging activity. This challenge has its positive counterpart as a lot has been learned from confronting a large variety of nuclear materials, complex material transfers and transformations. Since the inception of its computerized nuclear materials management system, AREVA NC La Hague has relied upon its IT subsidiary EURIWARE for software design and development. In 2003, the founding milestone was the implementation of the new GMP software package (Gestion des Matieres et des Produits - Materials and Products Management). GMP was underpinned by the following principles: reliability, transparency and close integration with the process control layer, so as to mitigate human errors and keep the management process smooth and efficient. In 2005, another major milestone was reached with CMNR (Comptabilite des Matieres Nucleaires Reglementaire - Regulatory Nuclear Materials Accountancy), a system in charge of local accounting and multi-site consolidation at corporate level. In spite of an auspicious start, GMP came up against the same stumbling block as many information systems: the multiplication of interfaces and technologies (entropy increasing over time). For the sake of maintenance, evolutions and performance, AREVA has decided a progressive modernization of its Nuclear Materials Management (NMM) information system. The underlying principle is a clear separation between the main functions: - Physical Follow-up, performed at the plant-level, - Regulatory Accountancy (for IRSN, EURATOM and IAEA safeguards), offering consolidation at the corporate level, - Patrimonial Accountancy (allocation of materials and conditioned wastes to AREVA's customers). The pivotal piece of this multi-year programme is the implementation of a dedicated data repository. We describe its main building blocks and demonstrate how it helps in managing changes to regulation, products, customers and

  2. New ways of integrating material knowledge into the design process

    DEFF Research Database (Denmark)

    Højris, Anders; Nielsen, Louise Møller

    2013-01-01

    Throughout resent years a constantly growing number of new materials have been developed, presenting improved abilities or entirely new features. In the design studio context, this has led to the emergence of physical material libraries, some for internal use and others entirely for external use ...... and not on the materials’ technical data. One of the cases further illustrates three types of material search strategies, which the designers apply in the early phases of the design process....... in order to help clients to find the right material among hundreds of samples. Furthermore a number of material libraries have also been developed into online database, which provides detailed information about new material and makes the information accessible from almost everywhere. The access to material...

  3. Domestic change in the face of European Integration and Globalization

    DEFF Research Database (Denmark)

    Lynggaard, Kennet

    2011-01-01

    Before the early 2000s, research on Europeanization and globalization developed largely independently of each other. Since then a limited, yet increasing, number of studies have shown an interest in investigating and differentiating between the domestic implications of European integration - known...... as Europeanization - and trends which are usually seen as having a broader global application including market liberalization, the construction of global institutions and policies. While research concerned with domestic change in the face of European integration and globalization in itself is a reaction to pressing...... epistemological concerns within the Europeanization literature, this in-the-making research agenda is also faced with a number of methodological challenges. This article deals with some of the most pressing methodological challenges we face when conducting empirical research and moving towards more comprehensive...

  4. A Gibbs Formulation for Reactive Materials with Phase Change

    Science.gov (United States)

    Stewart, D. Scott

    2015-11-01

    A large class of applications have pure, condensed phase constituents that come into contact, chemically react and simultaneously undergo phase change. Phase change in a given molecular material has often been considered to be separate from chemical reaction. Continuum modelers of phase change often use a phase field model whereby an indicator function is allowed to change from one value to another in regions of phase change, governed by evolutionary (Ginzburg-Landau) equations, whereas classic chemical kinetics literally count species concentrations and derive kinetics evolution equations based on species mass transport. We argue the latter is fundamental and is the same as the former, if all species, phase or chemical are treated as distinct chemical species. We pose a self-consistent continuum, thermo-mechanical model to account for significant energetic quantities with correct molecular and continuum limits in the mixture. A single stress tensor, and a single temperature is assumed for the mixture with specified Gibbs potentials for all relevant species, and interaction energies. We discuss recent examples of complex reactive material modeling, drawn from thermitic and propellant combustion that use this new model. DSS supported by DTRA, ONR and AFOSR.

  5. Ultrafast response of phase-change memory materials

    Science.gov (United States)

    Lindenberg, Aaron

    2015-03-01

    We describe recent experiments probing the first steps in the amorphous-to-crystalline transition that underlies the behavior of phase-change materials, examining both electric-field-driven and optically-driven responses in GeSbTe and AgInSbTe alloys. First measurements using femtosecond x-ray pulses at the Linac Coherent Light Source will be described which enable direct snapshots of these transitions and associated intermediate states. We will also describe studies using single-cycle terahertz pulses as an all-optical means of biasing phase-change materials on femtosecond time-scales in order to examine the threshold-switching response on microscopically relevant time-scales. These studies indicate nonlinear scaling with the applied electric field and field-induced crystallization as evidenced by ultrafast optical reflectivity and conductivity measurements, from which a mechanistic understanding of these phase transitions can be obtained.

  6. Materials Characterization and Microelectronic Implementation of Metal-insulator Transition Materials and Phase Change Materials

    Science.gov (United States)

    2015-03-26

    Transition MM Metamaterial MO Molecular Orbital MRAM Magnetic Random Access Memory MTFET Mott Transition Field-effect Transistor NA Numerical... Memory Devices Based on Free-standing VO2/TiO2 Microstructures Driven by Joule Heating," Adv. Mater., vol. 24, pp. 2929-2934, 2012. [57] R...Change Memory Devices," in IEEE, 2009. [98] M. Boniardi, A. Redaelli, A. Pirovano, I. Tortorelli, D. Ielmini and F. Pellizzer, "A physics- based

  7. Generation IV Reactors Integrated Materials Technology Program Plan: Focus on Very High Temperature Reactor Materials

    Energy Technology Data Exchange (ETDEWEB)

    Corwin, William R [ORNL; Burchell, Timothy D [ORNL; Katoh, Yutai [ORNL; McGreevy, Timothy E [ORNL; Nanstad, Randy K [ORNL; Ren, Weiju [ORNL; Snead, Lance Lewis [ORNL; Wilson, Dane F [ORNL

    2008-08-01

    the structural materials needed to ensure their safe and reliable operation. The focus of this document will be the overall range of DOE's structural materials research activities being conducted to support VHTR development. By far, the largest portion of material's R&D supporting VHTR development is that being performed directly as part of the Next-Generation Nuclear Plant (NGNP) Project. Supplementary VHTR materials R&D being performed in the DOE program, including university and international research programs and that being performed under direct contracts with the American Society for Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, will also be described. Specific areas of high-priority materials research that will be needed to deploy the NGNP and provide a basis for subsequent VHTRs are described, including the following: (1) Graphite: (a) Extensive unirradiated materials characterization and assessment of irradiation effects on properties must be performed to qualify new grades of graphite for nuclear service, including thermo-physical and mechanical properties and their changes, statistical variations from billot-to-billot and lot-to-lot, creep, and especially, irradiation creep. (b) Predictive models, as well as codification of the requirements and design methods for graphite core supports, must be developed to provide a basis for licensing. (2) Ceramics: Both fibrous and load-bearing ceramics must be qualified for environmental and radiation service as insulating materials. (3) Ceramic Composites: Carbon-carbon and SiC-SiC composites must be qualified for specialized usage in selected high-temperature components, such as core stabilizers, control rods, and insulating covers and ducting. This will require development of component-specific designs and fabrication processes, materials characterization, assessment of environmental and irradiation effects, and establishment of codes and standards for materials testing and design

  8. Study of Phase Change Materials Applied to CPV Receivers

    Directory of Open Access Journals (Sweden)

    Zun-Hao Shih

    2015-01-01

    Full Text Available There are lots of factors which can directly affect output efficiency of photovoltaic device. One of them is high temperature which would cause adverse effect to solar cell. When solar cell is operated in high temperature, the cell’s output efficiency will become low. Therefore, improving thermal spreading of solar cell is an important issue. In this study, we focused on finding new materials to enhance the thermal dispreading and keep the temperature of solar cell as low as possible. The new materials are different from conventional metal ones; they are called “phase change materials (PCMs” which are mainly applied to green buildings. We chose two kinds of PSMs to study their thermal dispreading ability and to compare them with traditional aluminum material. These two kinds of PCMs are wax and lauric acid. We made three aluminum-based cuboids as heat sinking units and two of them were designed with hollow space to fill in the PCMs. We applied electric forward bias on solar cells to simulate the heat contributed from the concentrated sunlight. Then we observed the thermal distribution of these three kinds of thermal spreading materials. Two levels of forward biases were chosen to test the samples and analyze the experiment results.

  9. Scalability of Phase Change Materials in Nanostructure Template

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    2015-01-01

    Full Text Available The scalability of In2Se3, one of the phase change materials, is investigated. By depositing the material onto a nanopatterned substrate, individual In2Se3 nanoclusters are confined in the nanosize pits with well-defined shape and dimension permitting the systematic study of the ultimate scaling limit of its use as a phase change memory element. In2Se3 of progressively smaller volume is heated inside a transmission electron microscope operating in diffraction mode. The volume at which the amorphous-crystalline transition can no longer be observed is taken as the ultimate scaling limit, which is approximately 5 nm3 for In2Se3. The physics for the existence of scaling limit is discussed. Using phase change memory elements in memory hierarchy is believed to reduce its energy consumption because they consume zero leakage power in memory cells. Therefore, the phase change memory applications are of great importance in terms of energy saving.

  10. Complex Nonlinearity Chaos, Phase Transitions, Topology Change and Path Integrals

    CERN Document Server

    Ivancevic, Vladimir G

    2008-01-01

    Complex Nonlinearity: Chaos, Phase Transitions, Topology Change and Path Integrals is a book about prediction & control of general nonlinear and chaotic dynamics of high-dimensional complex systems of various physical and non-physical nature and their underpinning geometro-topological change. The book starts with a textbook-like expose on nonlinear dynamics, attractors and chaos, both temporal and spatio-temporal, including modern techniques of chaos–control. Chapter 2 turns to the edge of chaos, in the form of phase transitions (equilibrium and non-equilibrium, oscillatory, fractal and noise-induced), as well as the related field of synergetics. While the natural stage for linear dynamics comprises of flat, Euclidean geometry (with the corresponding calculation tools from linear algebra and analysis), the natural stage for nonlinear dynamics is curved, Riemannian geometry (with the corresponding tools from nonlinear, tensor algebra and analysis). The extreme nonlinearity – chaos – corresponds to th...

  11. Surface modification of a POSS-nanocomposite material to enhance cellular integration of a synthetic bioscaffold.

    Science.gov (United States)

    Crowley, Claire; Klanrit, Poramate; Butler, Colin R; Varanou, Aikaterini; Platé, Manuela; Hynds, Robert E; Chambers, Rachel C; Seifalian, Alexander M; Birchall, Martin A; Janes, Sam M

    2016-03-01

    Polyhedral oligomeric silsesquioxane poly(carbonate-urea) urethane (POSS-PCU) is a versatile nanocomposite biomaterial with growing applications as a bioscaffold for tissue engineering. Integration of synthetic implants with host tissue can be problematic but could be improved by topographical modifications. We describe optimization of POSS-PCU by dispersion of porogens (sodium bicarbonate (NaHCO3), sodium chloride (NaCl) and sucrose) onto the material surface, with the principle aim of increasing surface porosity, thus providing additional opportunities for improved cellular and vascular ingrowth. We assess the effect of the porogens on the material's mechanical strength, surface chemistry, wettability and cytocompatibilty. Surface porosity was characterized by scanning electron microscopy (SEM). There was no alteration in surface chemistry and wettability and only modest changes in mechanical properties were detected. The size of porogens correlated well with the porosity of the construct produced and larger porogens improved interconnectivity of spaces within constructs. Using primary human bronchial epithelial cells (HBECs) we demonstrate moderate in vitro cytocompatibility for all surface modifications; however, larger pores resulted in cellular aggregation. These cells were able to differentiate on POSS-PCU scaffolds. Implantation of the scaffold in vivo demonstrated that larger pore sizes favor cellular integration and vascular ingrowth. These experiments demonstrate that surface modification with large porogens can improve POSS-PCU nanocomposite scaffold integration and suggest the need to strike a balance between the non-porous surfaces required for epithelial coverage and the porous structure required for integration and vascularization of synthetic scaffolds in future construct design.

  12. The Study of the Thermoelectric Properties of Phase Change Materials

    Science.gov (United States)

    Yin, Ming; Abdi, Mohammed; Noimande, Zibusisu; Mbamalu, Godwin; Alameeri, Dheyaa; Datta, Timir

    We study thermoelectric property that is electrical phenomena occurring in conjunction with the flow of heat of phase-change materials (PCM) in particular GeSbTe (GST225). From given sets of material parameters, COMSOL Multiphysics heat-transfer module is used to compute maps of temperature and voltage distribution in the PCM samples. These results are used to design an apparatus including the variable temperature sample holder set up. An Arbitrary/ Function generator and a circuit setup is also designed to control the alternation of heaters embedded on the sample holder in order to ensure sequential back and forward flow of heat current from both sides of the sample. Accurate values of potential differences and temperature distribution profiles are obtained in order to compute the Seebeck coefficient of the sample. The results of elemental analysis and imaging studies such as XRD, UV-VIS, EDEX and SEM of the sample are obtained. Factors affecting the thermoelectric properties of phase change memory are also discussed. NNSA/ DOD Consortium for Materials and Energy Studies.

  13. A phenomenological approach of solidification of polymeric phase change materials

    Science.gov (United States)

    Bahrani, Seyed Amir; Royon, Laurent; Abou, Bérengère; Osipian, Rémy; Azzouz, Kamel; Bontemps, André

    2017-01-01

    Phase Change Materials (PCMs) are widely used in thermal energy storage and thermal management systems due to their small volume for a given stored energy and their capability for maintaining nearly constant temperatures. However, their performance is limited by their low thermal conductivity and possible leaks while in the liquid phase. One solution is to imprison the PCM inside a polymer mesh to create a Polymeric Phase Change Material (PPCM). In this work, we have studied the cooling and solidification of five PPCMs with different PCMs and polymer fractions. To understand the heat transfer mechanisms involved, we have carried out micro- and macrorheological measurements in which Brownian motion of tracers embedded in PPCMs has been depicted and viscoelastic moduli have been measured, respectively. Beyond a given polymer concentration, it was shown that the Brownian motion of the tracers is limited by the polymeric chains and that the material exhibits an elastic behavior. This would suggest that heat transfer essentially occurs by conduction, instead of convection. Experiments were conducted to measure temperature variation during cooling of the five samples, and a semi-empirical model based on a phenomenological approach was proposed as a practical tool to choose and size PPCMs.

  14. Silicon integrated circuits advances in materials and device research

    CERN Document Server

    Kahng, Dawon

    1981-01-01

    Silicon Integrated Circuits, Part B covers the special considerations needed to achieve high-power Si-integrated circuits. The book presents articles about the most important operations needed for the high-power circuitry, namely impurity diffusion and oxidation; crystal defects under thermal equilibrium in silicon and the development of high-power device physics; and associated technology. The text also describes the ever-evolving processing technology and the most promising approaches, along with the understanding of processing-related areas of physics and chemistry. Physicists, chemists, an

  15. Porous MgO material with ultrahigh surface area as the matrix for phase change composite

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Yonggan; Shao, Xiankun; Liu, Tongxuan [School of Materials Science and Engineering, Anhui University of Science and Technology, Huainan, Anhui 232001 (China); Li, Benxia, E-mail: libx@mail.ustc.edu.cn [School of Materials Science and Engineering, Anhui University of Science and Technology, Huainan, Anhui 232001 (China); Nie, Shibin, E-mail: nsb@mail.ustc.edu.cn [School of Energy Resources and Safety, Anhui University of Science and Technology, Huainan, Anhui 232001 (China)

    2015-03-20

    Highlights: • Porous MgO material with ultrahigh surface area was synthesized. • A composite PCM was prepared from PEG-1000 and the porous MgO. • The phase change temperatures and enthalpy of the composite were measured. • The composite PCM performed good shape-stabilized property. - Abstract: Mesoporous magnesium oxide (MgO) material was synthesized using an integration of the evaporation-induced surfactant assembly and magnesium nitrate pyrolysis. The as-prepared MgO material is well crystalline, and possesses three-dimensional interconnected mesopores and a surface area as high as 596 m{sup 2}/g. Using the porous MgO as a matrix and polyethylene glycol (PEG-1000) as the functional phase for heat energy storage, a shape-stabilized phase change composite of PEG/MgO was fabricated by an easy impregnation method. In the composite, mesoporous MgO material provides structural strength and prevents the leakage of the molten PEG during the phase change process. The compositions and microstructures of the PEG/MgO composite were determined by Fourier transformation infrared spectroscope (FT-IR), X-ray diffractometer (XRD), scanning electronic microscope (SEM) and thermogravimetric analyzer (TGA), respectively. The phase change properties of the PEG/MgO composite were determined by differential scanning calorimeter (DSC). The high heat-energy storage capability and good thermal stability of the composite enable it extensive applications in the future.

  16. Pickering Emulsification to Mass Produce Nanoencapsulated Phase-change-material

    Science.gov (United States)

    Wang, Xuezhen; Zhang, Lecheng; Yu, Yi-Hsien; Mannan, S. Sam; Chen, Ying; Cheng, Zhengdong; Cheng's Group Team, Dr.

    2015-03-01

    Phase changing materials (PCM) have useful applications in thermal management. However, mass production of micro and nano encapsulated PCM has been a challenge. Here, we present a simple and scalable method via a two-step Pickering emulsification method. We have developed interface active nanoplates by asymmetric modification of nanoplates of layered crystal materials. Nanoencapsulated PCM is realized with exfoliated monolayer nanoplates surfactants using very little energy input for emulsification. Further chemical reactions are performed to convert the emulsions into core-shell structures. The resulted capsules are submicron in size with remarkable uniformity in size distribution. DSC characterization showed that the capsulation efficiency of NEPCM was 58.58% and were thermal stable which was characterized by the DSC data for the sample after 200 thermal cycling.

  17. Review on phase change materials for building applications

    Directory of Open Access Journals (Sweden)

    Lavinia SOCACIU

    2014-11-01

    Full Text Available In nowadays, the Phase Change Material (PCM is a viable alternative for reducing the energy consumption and for increase the thermal comfort in buildings. The use of PCM in building applications provides the potential to increase the indoor thermal comfort for occupants due to the reduced indoor temperature fluctuations and lower global energy consumption. The possibility to incorporate the PCM into the material of construction for cooling and heating the buildings gained the interest of researchers from all the world because the PCM have a high heat of fusion, meaning it is capable to storing and release large amounts of energy in the form of heat during its melting and solidifying process at a specific temperature.

  18. Microencapsulated Phase Change Composite Materials for Energy Efficient Buildings

    Science.gov (United States)

    Thiele, Alexander

    This study aims to elucidate how phase change material (PCM)-composite materials can be leveraged to reduce the energy consumption of buildings and to provide cost savings to ratepayers. Phase change materials (PCMs) can store thermal energy in the form of latent heat when subjected to temperatures exceeding their melting point by undergoing a phase transition from solid to liquid state. Reversibly, PCMs can release this thermal energy when the system temperature falls below their solidification point. The goal in implementing composite PCM walls is to significantly reduce and time-shift the maximum thermal load on the building in order to reduce and smooth out the electricity demand for heating and cooling. This Ph.D. thesis aims to develop a set of thermal design methods and tools for exploring the use of PCM-composite building envelopes and for providing design rules for their practical implementation. First, detailed numerical simulations were used to show that the effective thermal conductivity of core-shell-matrix composites depended only on the volume fraction and thermal conductivity of the constituent materials. The effective medium approximation reported by Felske (2004) was in very good agreement with numerical predictions of the effective thermal conductivity. Second, a carefully validated transient thermal model was used to simulate microencapsulated PCM-composite walls subjected to diurnal or annual outdoor temperature and solar radiation flux. It was established that adding microencapsulated PCM to concrete walls both substantially reduced and delayed the thermal load on the building. Several design rules were established, most notably, (i) increasing the volume fraction of microencapsulated PCM within the wall increases the energy savings but at the potential expense of mechanical properties [1], (ii) the phase change temperature leading to the maximum energy and cost savings should equal the desired indoor temperature regardless of the climate

  19. Energy harvesting: an integrated view of materials, devices and applications.

    Science.gov (United States)

    Radousky, H B; Liang, H

    2012-12-21

    Energy harvesting refers to the set of processes by which useful energy is captured from waste, environmental, or mechanical sources and is converted into a usable form. The discipline of energy harvesting is a broad topic that includes established methods and materials such as photovoltaics and thermoelectrics, as well as more recent technologies that convert mechanical energy, magnetic energy and waste heat to electricity. This article will review various state-of-the-art materials and devices for direct energy conversion and in particular will include multistep energy conversion approaches. The article will highlight the nano-materials science underlying energy harvesting principles and devices, but also include more traditional bulk processes and devices as appropriate and synergistic. Emphasis is placed on device-design innovations that lead to higher efficiency energy harvesting or conversion technologies ranging from the cm/mm-scale down to MEMS/NEMS (micro- and nano-electromechanical systems) devices. Theoretical studies are reviewed, which address transport properties, crystal chemistry, thermodynamic analysis, energy transfer, system efficiency and device operation. New developments in experimental methods; device design and fabrication; nanostructured materials fabrication; materials properties; and device performance measurement techniques are discussed.

  20. Thermal performance of sodium acetate trihydrate thickened with different materials as phase change energy storage material

    Energy Technology Data Exchange (ETDEWEB)

    Cabeza, L.F. [Universitat de Lleida (Spain); Svensson, G.; Hiebler, S.; Mehling, H. [ZAE Bayern, Garching (Germany)

    2003-09-01

    The use of phase change materials (PCMs) in energy storage has the advantage of high energy density and isothermal operation. Although the use of only non-segregating PCMs is a good commercial approach, some desirable PCM melting points do not seem attainable with non-segregating salt hydrates at a reasonable price. The addition of gellants and thickeners can avoid segregation of these materials. In this paper, sodium acetate trihydrate is successfully thickened with bentonite and starch. Cellulose gives an even better thickened PCM, but temperatures higher than 65 {sup o}C give phase separation. The mixtures would show a similar thermal behavior as the salt hydrate, with the same melting point and an enthalpy decrease between 20% and 35%, depending on the type and amount of thickening material used. (Author)

  1. Electric-field-assisted crystallisation in phase-change materials

    Energy Technology Data Exchange (ETDEWEB)

    Kohary, Krisztian; Diosdado, Jorge A.V.; Ashwin, Peter; Wright, C. David [College of Engineering, Mathematics, and Physical Sciences, University of Exeter (United Kingdom)

    2012-10-15

    Phase-change materials are of intense research interest due mainly to their use in phase-change memory (PCM) devices that are emerging as a promising technology for future non-volatile, solid-state, electrical storage. Electrically driven transitions from the amorphous to the crystalline phase in such devices exhibit characteristic threshold switching. Several alternative electronic explanations for the origins of this characteristic behaviour have been put forward, for example Poole-Frenkel effects, delocalisation of tail states, field emission processes and space charge limited currents [for a full discussion, see Radielli et al., J. Appl. Phys. 103, 111101 (2008) and Simon et al., MRS Proc. 1251, H01-H011 (2010)]. However, an alternative to these conventional electronic models of threshold switching is based on electric field induced lowering of the system free energy, leading to the field induced nucleation of conducting crystal filaments. In this paper we investigate this alternative view. We present a detailed kinetics study of crystallisation in the presence of an electric field for the phase-change material Ge{sub 2}Sb{sub 2}Te{sub 5}. We derive quantitative crystallisation maps to show the effects of both temperature and electric field on crystallisation and we identify field ranges and parameter values where the electric field might play a significant role. Then we carry out physically realistic simulations of the threshold switching process in typical phase-change device structures, both with and without electric field dependent energy contributions to the system free energy. Our results show that threshold switching can be obtained by a mechanism driven purely by electric field induced nucleation, but the fields so required are large, of the order of 300 MV m{sup -1}, and significantly larger than the experimentally measured threshold fields. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. Design, Fabrication, Characterization and Modeling of Integrated Functional Materials

    Science.gov (United States)

    2012-10-01

    purpose of this project is to develop the novel science base both in the areas of multi-scale dimensional integration as well as multiple functional...iron oxide nanoparticles have been widely explored because of their potential applications in various fields, including storage media, environmental... Wold , J. Solid State Chem. 1972, 5, 136. 44. A. A. Gippius, K.S. Okhotnikov, M. Baeritz, A. V. Shevelkov, Solid State Phenomena 2009, 152, 287. 45. C

  3. A THIRD WAY: ONLINE LABS INTEGRATED WITH PRINT MATERIALS

    Directory of Open Access Journals (Sweden)

    Roger Falmer

    2012-07-01

    Full Text Available Abstract: The use of ICT in language education to enhance classroom-based instruction is examined in reference to blended learning. A blended model of integrating technological advances via an online lab with a face-to-face classroom environment is presented. The example of this operating in practice is iZone, a four-level print-digital series designed with the online component called MyiZoneLab at its heart, forming a cohesive and inseparable whole with its accompanying texts. Overcoming the limitations of classroom-only instruction is a particular strength of advances in computer technology. Delivering a unified body of content through different mediums is in effect a third way, neither just online nor simply in class, and this newer model has the capability to fully exploit and reinforce the advantages of each separate medium. Online access via a web browser may make good on the promise of studying whenever the learner desires, wherever they happen to be. To this movement towards flexibility in time and place is added a further ingredient, that of choice in self-study or learning with others, and of matching the time the individual spends on tasks to their needs. Integration and inseparability are inherent in this blended model, unleashing the potentiality of technological developments in language education while seeking to transcend the either online or face-to-face learning dichotomy. Keywords: ICT (Information and Communications Technology, blended learning; online labs, F2F (face-to-face, integration

  4. Sb-Te Phase-change Materials under Nanoscale Confinement

    Science.gov (United States)

    Ihalawela, Chandrasiri A.

    Size, speed and efficiency are the major challenges of next generation nonvolatile memory (NVM), and phase-change memory (PCM) has captured a great attention due to its promising features. The key for PCM is rapid and reversible switching between amorphous and crystalline phases with optical or electrical excitation. The structural transition is associated with significant contrast in material properties which can be utilized in optical (CD, DVD, BD) and electronic (PCRAM) memory applications. Importantly, both the functionality and the success of PCM technology significantly depend on the core material and its properties. So investigating PC materials is crucial for the development of PCM technology to realized enhanced solutions. In regards to PC materials, Sb-Te binary plays a significant role as a basis to the well-known Ge-Sb-Te system. Unlike the conventional deposition methods (sputtering, evaporation), electrochemical deposition method is used due to its multiple advantages, such as conformality, via filling capability, etc. First, the controllable synthesis of Sb-Te thin films was studied for a wide range of compositions using this novel deposition method. Secondly, the solid electrolytic nature of stoichiometric Sb2Te3 was studied with respect to precious metals. With the understanding of 2D thin film synthesis, Sb-Te 1D nanowires (18 - 220 nm) were synthesized using templated electrodeposition, where nanoporous anodic aluminum oxide (AAO) was used as a template for the growth of nanowires. In order to gain the controllability over the deposition in high aspect ratio structures, growth mechanisms of both the thin films and nanowires were investigated. Systematic understanding gained thorough previous studies helped to formulate the ultimate goal of this dissertation. In this dissertation, the main objective is to understand the size effect of PC materials on their phase transition properties. The reduction of effective memory cell size in conjunction with

  5. Geometric space-time integration of ferromagnetic materials

    NARCIS (Netherlands)

    Frank, J.E.

    2003-01-01

    The Landau-Lifshitz equation (LLE) governing the flow of magnetic spin in a ferromagnetic material is a PDE with a noncanonical Hamiltonian structure. In this paper we derive a number of new formulations of the LLE as a partial differential equation on a multisymplectic structure. Using this form we

  6. Geometric space-time integration of ferromagnetic materials

    NARCIS (Netherlands)

    Frank, J.E.

    2004-01-01

    The Landau-Lifshitz equation (LLE) governing the flow of magnetic spin in a ferromagnetic material is a PDE with a noncanonical Hamiltonian structure. In this paper we derive a number of new formulations of the LLE as a partial differential equation on a multisymplectic structure. Using this form we

  7. Maintenance modeling and optimization integrating human and material resources

    Energy Technology Data Exchange (ETDEWEB)

    Martorell, S., E-mail: smartore@iqn.upv.e [Dpto. Ingenieria Quimica y Nuclear, Universidad Politecnica Valencia (Spain); Villamizar, M.; Carlos, S. [Dpto. Ingenieria Quimica y Nuclear, Universidad Politecnica Valencia (Spain); Sanchez, A. [Dpto. Estadistica e Investigacion Operativa Aplicadas y Calidad, Universidad Politecnica Valencia (Spain)

    2010-12-15

    Maintenance planning is a subject of concern to many industrial sectors as plant safety and business depend on it. Traditionally, the maintenance planning is formulated in terms of a multi-objective optimization (MOP) problem where reliability, availability, maintainability and cost (RAM+C) act as decision criteria and maintenance strategies (i.e. maintenance tasks intervals) act as the only decision variables. However the appropriate development of each maintenance strategy depends not only on the maintenance intervals but also on the resources (human and material) available to implement such strategies. Thus, the effect of the necessary resources on RAM+C needs to be modeled and accounted for in formulating the MOP affecting the set of objectives and constraints. In this paper RAM+C models to explicitly address the effect of human resources and material resources (spare parts) on RAM+C criteria are proposed. This extended model allows accounting for explicitly how the above decision criteria depends on the basic model parameters representing the type of strategies, maintenance intervals, durations, human resources and material resources. Finally, an application case is performed to optimize the maintenance plan of a motor-driven pump equipment considering as decision variables maintenance and test intervals and human and material resources.

  8. An Integrated Tool for Estimation of Material Model Parameters (PREPRINT)

    Science.gov (United States)

    2010-04-01

    images were processed using Vic- 3D, and approximately 60,000 data points per load step were analyzed. The Bunge -Euler angles, Φ1, Ψ and Φ2, were used...be useful. Second, for small values of Bunge -Euler angles, σ2 and σ3 are non-zero in the material coordinate system but of very small magnitude

  9. Performance Evaluation of Neutron Absorption Materials with Temperature Change

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hae Sun; Jeong, Hyo Joon; Kim, Eun Han; Han, Moon Hee; Hwang, Won Tae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    Some of these facilities are operated at higher than room temperature, thus the neutron absorption material can be directly affected by the surrounding environment where the temperature is not maintained in a constant condition. Meanwhile, a nucleus in an atom is continuously vibrated with the thermal energy, after which there arises a range of relative speeds between a neutron and the nucleus, even for a fixed neutron speed. At higher temperature, the random motion of the nucleus reproduces new resonance with a lower and broader peak, i.e., Doppler broadening of a resonance, and the capture cross section of neutron is revised. Therefore, the performance of neutron absorption materials may vary with a change of temperature. In this study, the absorption abilities of three kinds of neutron absorbers generally used in the reactor core were analyzed at a range of temperatures from 293.6K to 584K. As a result, the neutron absorption abilities for B{sup 4}C and Ag-In-Cd do not vary with the change of temperature, while that for Gd{sup 2}O{sup 3} absorbers was shown to be decreased approximately 3% with reference to that at 293.6K in the temperature range between the 293.6K and 584K. This phenomenon of the Gd{sup 2}O{sup 3} absorber seems to be caused by the Doppler broadening of the neutron absorption cross-section. Therefore, it is expected that the effect of material temperature on the neutron absorption performance is needed to be considered in the design of nuclear reactor and the analysis of radiation shielding.

  10. Electronic transport in amorphous phase-change materials

    Energy Technology Data Exchange (ETDEWEB)

    Luckas, Jennifer Maria

    2012-09-14

    Phase change materials combine a pronounced contrast in resistivity and reflectivity between their disordered amorphous and ordered crystalline state with very fast crystallization kinetics. Due to this exceptional combination of properties phase-change materials find broad application in non-volatile optical memories such as CD, DVD or Bluray Disc. Furthermore, this class of materials demonstrates remarkable electrical transport phenomena in their disordered state, which have shown to be crucial for their application in electronic storage devices. The threshold switching phenomenon denotes the sudden decrease in resistivity beyond a critical electrical threshold field. The threshold switching phenomenon facilitates the phase transitions at practical small voltages. Below this threshold the amorphous state resistivity is thermally activated and is observed to increase with time. This effect known as resistance drift seriously hampers the development of multi-level storage devices. Hence, understanding the physical origins of threshold switching and resistance drift phenomena is crucial to improve non-volatile phase-change memories. Even though both phenomena are often attributed to localized defect states in the band gap, the defect state density in amorphous phase-change materials has remained poorly studied. Starting from a brief introduction of the physics of phase-change materials this thesis summarizes the most important models behind electrical switching and resistance drift with the aim to discuss the role of localized defect states. The centerpiece of this thesis is the investigation of defects state densities in different amorphous phase-change materials and electrical switching chalcogenides. On the basis of Modulated Photo Current (MPC) Experiments and Photothermal Deflection Spectroscopy, a sophisticated band model for the disordered phase of the binary phase-change alloy GeTe has been developed. By this direct experimental approach the band-model for a

  11. An investigation on phase change materials to reduce summer overheating

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, S.; Kornadt, O. [Bauhaus-University Weimar, Weimar (Germany). Dept. of Building Physics

    2006-07-01

    The overheating problem in office buildings can be partially attributed to modern architectural constructions with high glazing facades and light-weight constructions. One way to solve the problem is to use phase change materials (PCMs) which are heat accumulators that store and release heat during the phase change process. PCMs increase the thermal mass in buildings and help reduce peak temperatures during summer hot spells. This study examined the heat storing effect of PCMs and their potential use in the building sector. In particular, 2 PCMs were examined in full scale experiments at the Bauhaus-University Weimar. The study examined the effects of PCMs placed on the surface of inner partitioning, ceilings or floors that could be numerically treated as a separate layer with room-side heat transfer one side and heat conduction to the next layers on the other side. Experimental results led to the development of a numerical description of the phase change process with and without super-cooling. The numerical description was based on temperature dependent functions for heat capacity and thermal conductivity. This presentation described the validation, stability and accuracy of the model and proposed recommendations. Simulation results of PCM-plaster with micro-encapsulated paraffin show the potential of a marketable material. In addition to optimizing the melting temperature and layer thickness, an important criterion for PCM efficiency is the number of overheating hours that can be reduced. For a European climate, a 3 cm layer thick PCM plaster with optimized peak temperature can reduce overheating hours by 25 to 50 per cent. 15 refs., 1 tab., 8 figs.

  12. Electrochemical materials and processes in Si integrated circuit technology

    Energy Technology Data Exchange (ETDEWEB)

    Dubin, V.M. [Intel Corp., Components Research, Hillsboro, OR 97124 (United States)]. E-mail: valery.m.dubin@intel.com; Akolkar, R. [Intel Corp., Components Research, Hillsboro, OR 97124 (United States); Cheng, C.C. [Intel Corp., Components Research, Hillsboro, OR 97124 (United States); Chebiam, R. [Intel Corp., Components Research, Hillsboro, OR 97124 (United States); Fajardo, A. [Intel Corp., Components Research, Hillsboro, OR 97124 (United States); Gstrein, F. [Intel Corp., Components Research, Hillsboro, OR 97124 (United States)

    2007-02-10

    Various technical issues related to feature scaling and recent electrochemical technologies advances for on-chip copper interconnects at Intel are reviewed. Effects of additives on electroplating, as well as performance of novel Cu direct plating on ruthenium liner are discussed. An electroless cobalt capping layer of Cu lines, which led to increased electromigration resistance, has been characterized. The potential application of carbon nanotubes as future interconnects materials, their properties and controlled placement by using dielectrophoresis are also reviewed.

  13. Tonpilz Underwater Acoustic Transducer Integrating Lead-free Piezoelectric Material

    Science.gov (United States)

    Rouffaud, Rémi; Granger, Christian; Hladky-Hennion, Anne-Christine; Thi, Mai Pham; Levassort, Franck

    A Tonpilz transducer based on lead-free piezoelectric material was fabricated, modeled and characterized. The stack is composed of two rings of doped BaTiO3. This composition was initially chosen due to good electromechanical performance (kt at 40%) and high mechanical quality factor (Qm over 500). Comparison of the displacement at the center of the head mass was performed with a PZT-based Tonpilz with the same design for a center frequency at 22 kHz.

  14. Integrating Simulation and Data for Materials in Extreme Environments

    Science.gov (United States)

    Germann, Timothy

    2014-03-01

    We are using large-scale molecular dynamics (MD) simulations to study the response of nanocrystalline metals such as tantalum to uniaxial (e.g., shock) compression. With modern petascale-class platforms, we are able to model sample sizes with edge lengths over one micrometer, which match the length and time scales experimentally accessible at Argonne's Advanced Photon Source (APS) and SLAC's Linac Coherent Light Source (LCLS). I will describe our simulation predictions and their recent verification at LCLS, as well as outstanding challenges in modeling the response of materials to extreme mechanical and radiation environments, and our efforts to tackle these as part of the multi-institutional, multi-disciplinary Exascale Co-design Center for Materials in Extreme Environments (ExMatEx). ExMatEx has initiated an early and deep collaboration between domain (computational materials) scientists, applied mathematicians, computer scientists, and hardware architects, in order to establish the relationships between algorithms, software stacks, and architectures needed to enable exascale-ready materials science application codes within the next decade. We anticipate that we will be able to exploit hierarchical, heterogeneous architectures to achieve more realistic large-scale simulations with adaptive physics refinement, and are using tractable application scale-bridging proxy application testbeds to assess new approaches and requirements. The current scale-bridging strategies accumulate (or recompute) a distributed response database from fine-scale calculations, in a top-down rather than bottom-up multiscale approach. I will demonstrate this approach and our initial assessments, using the newly emerging capabilities at new 4th generation synchrotron light sources as an experimental driver.

  15. Fundamentals of Materials Science and Engineering: An Integrated Approach, 2nd Edition

    Science.gov (United States)

    Callister, William D., Jr.

    2004-04-01

    This Second Edition of Fundamentals of Materials Science and Engineering continues to take an integrated approach to the topic organization. One specific structure, characteristic, or property type at a time is discussed for all three basic material types--metals, ceramics, and polymeric materials. This order of presentation allows for early introduction of non-metals and supports the engineer's role of choosing a material based on its characteristics. New copies of this text include a CD at no additional charge. The CD is an integral part of the text package and features animated software modules and the last five text chapters in .pdf format.

  16. Improved data for integrated modeling of global environmental change

    Science.gov (United States)

    Lotze-Campen, Hermann

    2011-12-01

    The assessment of global environmental changes, their impact on human societies, and possible management options requires large-scale, integrated modeling efforts. These models have to link biophysical with socio-economic processes, and they have to take spatial heterogeneity of environmental conditions into account. Land use change and freshwater use are two key research areas where spatial aggregation and the use of regional average numbers may lead to biased results. Useful insights can only be obtained if processes like economic globalization can be consistently linked to local environmental conditions and resource constraints (Lambin and Meyfroidt 2011). Spatially explicit modeling of environmental changes at the global scale has a long tradition in the natural sciences (Woodward et al 1995, Alcamo et al 1996, Leemans et al 1996). Socio-economic models with comparable spatial detail, e.g. on grid-based land use change, are much less common (Heistermann et al 2006), but are increasingly being developed (Popp et al 2011, Schneider et al 2011). Spatially explicit models require spatially explicit input data, which often constrains their development and application at the global scale. The amount and quality of available data on environmental conditions is growing fast—primarily due to improved earth observation methods. Moreover, systematic efforts for collecting and linking these data across sectors are on the way (www.earthobservations.org). This has, among others, also helped to provide consistent databases on different land cover and land use types (Erb et al 2007). However, spatially explicit data on specific anthropogenic driving forces of global environmental change are still scarce—also because these cannot be collected with satellites or other devices. The basic data on socio-economic driving forces, i.e. population density and wealth (measured as gross domestic product per capita), have been prepared for spatially explicit analyses (CIESIN, IFPRI

  17. Integration of Magneto-Optical Materials for Novel Optical Devices & Magnetophotonic Crystals Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This work proposes to capitalize on our Phase I success in monolithically integrating magneto-optic and magnetic materials with semiconductor platforms in order to...

  18. Preliminary Design and Investigation of Integrated Compressor with Composite Material Wheel

    Science.gov (United States)

    Wang, Jifeng; Müller, Norbert

    2012-06-01

    An integrated water vapor compressor with composite material wheel is developed and strength analysis using FEM is presented. The design of wound composite material allows for integrating all rotating parts of the drive that may simply reduce to only the rotor of the electrical motor, since no drive shaft is required anymore. This design can reduce the number of parts and mass, which is convenient for engineers to maintain the compressor. The electrical motors are brushless DC motors operating through a frequency drive and apply a torque on the wheels through the materials bonded in the wheel shrouds. This system allows a large amount of compression to be produced in a multi-stage compression setup. To determine the stress and vibration characteristics of this integrated compressor, numerical analysis is carried out using FEM. The simulation result shows that the integrated compressor with composite material wheel can be used in a chiller system where water as a refrigerant.

  19. Electronic transport in amorphous phase-change materials

    Energy Technology Data Exchange (ETDEWEB)

    Luckas, Jennifer Maria

    2012-09-14

    Phase change materials combine a pronounced contrast in resistivity and reflectivity between their disordered amorphous and ordered crystalline state with very fast crystallization kinetics. Due to this exceptional combination of properties phase-change materials find broad application in non-volatile optical memories such as CD, DVD or Bluray Disc. Furthermore, this class of materials demonstrates remarkable electrical transport phenomena in their disordered state, which have shown to be crucial for their application in electronic storage devices. The threshold switching phenomenon denotes the sudden decrease in resistivity beyond a critical electrical threshold field. The threshold switching phenomenon facilitates the phase transitions at practical small voltages. Below this threshold the amorphous state resistivity is thermally activated and is observed to increase with time. This effect known as resistance drift seriously hampers the development of multi-level storage devices. Hence, understanding the physical origins of threshold switching and resistance drift phenomena is crucial to improve non-volatile phase-change memories. Even though both phenomena are often attributed to localized defect states in the band gap, the defect state density in amorphous phase-change materials has remained poorly studied. Starting from a brief introduction of the physics of phase-change materials this thesis summarizes the most important models behind electrical switching and resistance drift with the aim to discuss the role of localized defect states. The centerpiece of this thesis is the investigation of defects state densities in different amorphous phase-change materials and electrical switching chalcogenides. On the basis of Modulated Photo Current (MPC) Experiments and Photothermal Deflection Spectroscopy, a sophisticated band model for the disordered phase of the binary phase-change alloy GeTe has been developed. By this direct experimental approach the band-model for a

  20. Structure of covalently bonded materials: From the Peierls distortion to Phase-Change Materials

    Science.gov (United States)

    Gaspard, Jean-Pierre

    2016-03-01

    The relation between electronic structure and cohesion of materials has been a permanent quest of Jacques Friedel and his school. He developed simple models that are of great value as guidelines in conjunction with ab initio calculations. His local approach of bonding has both the advantages of a large field of applications including non-crystalline materials and a common language with chemists. Along this line, we review some fascinating behaviors of covalent materials, most of them showing a Peierls (symmetry breaking) instability mechanism, even in liquid and amorphous materials. We analyze the effect of external parameters such as pressure and temperature. In some temperature ranges, the Peierls distortion disappears and a negative thermal expansion is observed. In addition, the Peierls distortion plays a central role in Phase-Change Materials, which are very promising non-volatile memories. Son approche locale de la liaison chimique s'applique à un vaste champ de systèmes, incluant les matériaux non cristallins et permis un langage commun avec les chimistes. Dans cet axe nous passons en revue quelques comportements fascinants des matériaux covalents, la plupart d'entre eux présentant un mécanisme d'instabilité de Peierls (brisure de symétrie), même les liquides et les amorphes, étonnamment. Nous analysons aussi l'effet de parame'tres externes tels que la pression et la température. Dans un certain domaine de température, la distorsion de Peierls disparaît et une dilatation thermique négative est observée. Enfin, la distorsion de Peierls joue un rôle central dans les matériaux à changement de phase (PC materials), qui sont très prometteurs pour la réalisation de mémoires non volatiles.

  1. Enhancing heat capacity of colloidal suspension using nanoscale encapsulated phase-change materials for heat transfer.

    Science.gov (United States)

    Hong, Yan; Ding, Shujiang; Wu, Wei; Hu, Jianjun; Voevodin, Andrey A; Gschwender, Lois; Snyder, Ed; Chow, Louis; Su, Ming

    2010-06-01

    This paper describes a new method to enhance the heat-transfer property of a single-phase liquid by adding encapsulated phase-change nanoparticles (nano-PCMs), which absorb thermal energy during solid-liquid phase changes. Silica-encapsulated indium nanoparticles and polymer-encapsulated paraffin (wax) nanoparticles have been made using colloid method, and suspended into poly-alpha-olefin (PAO) and water for potential high- and low-temperature applications, respectively. The shells prevent leakage and agglomeration of molten phase-change materials, and enhance the dielectric properties of indium nanoparticles. The heat-transfer coefficients of PAO containing indium nanoparticles (30% by mass) and water containing paraffin nanoparticles (10% by mass) are 1.6 and 1.75 times higher than those of corresponding single-phase fluids. The structural integrity of encapsulation allows repeated use of such nanoparticles for many cycles in high heat generating devices.

  2. Feasibility study for pseudoscopic problem in integral imaging using negative refractive index materials.

    Science.gov (United States)

    Zhang, JianLei; Wang, XiaoRui; Chen, YuJiao; Zhang, QiPing; Yu, Shuo; Yuan, Ying; Guo, BingTao

    2014-08-25

    To solve the pseudoscopic problem, we propose a one-step integral imaging system with negative refractive index materials, which can avoid the deterioration in resolution inherent to the optical or digital two-step processes. Specifically, the proposed method is based on the novel feature of negative refractive index materials, bending light to a negative angle relative to the surface normal. The pseudoscopic imaging property of the negative refractive index material slab is theoretically investigated. For formation of orthoscopic reconstructed images, the matching condition of the negative index lens array and the positive index lens array is deduced. Two types of conceptual prototypes of integral imaging system with negative refractive index materials are designed. Experimental results show the validity of the proposed method. To the best of our knowledge, this is the first time to explore the application of negative index materials in eliminating the pseudoscopic effect in integral imaging.

  3. Cooling of mobile electronic devices using phase change materials

    Energy Technology Data Exchange (ETDEWEB)

    Tan, F.L.; Tso, C.P. [Nanyang Technological University (Singapore). School of Mechanical and Production Engineering

    2004-02-01

    An experimental study is conducted on the cooling of mobile electronic devices, such as personal digital assistants (PDAs) and wearable computers, using a heat storage unit (HSU) filled with the phase change material (PCM) of n-eicosane inside the device. The high latent heat of n-eicosane in the HSU absorbs the heat dissipation from the chips and can maintain the chip temperature below the allowable service temperature of 50{sup o}C for 2 h of transient operations of the PDA. The heat dissipation of the chips inside a PDA and the orientation of the HSU are experimentally investigated in this paper. It was found that different orientation of the HSU inside the PDA could affect significantly the temperature distribution. (author)

  4. Plastic phase change material and articles made therefrom

    Science.gov (United States)

    Abhari, Ramin

    2016-04-19

    The present invention generally relates to a method for manufacturing phase change material (PCM) pellets. The method includes providing a melt composition, including paraffin and a polymer. The paraffin has a melt point of between about 10.degree. C. and about 50.degree. C., and more preferably between about 18.degree. C. and about 28.degree. C. In one embodiment, the melt composition includes various additives, such as a flame retardant. The method further includes forming the melt composition into PCM pellets. The method further may include the step of cooling the melt to increase the melt viscosity before pelletizing. Further, PCM compounds are provided having an organic PCM and a polymer. Methods are provided to convert the PCM compounds into various form-stable PCMs. A method of coating the PCMs is included to provide PCMs with substantially no paraffin seepage and with ignition resistance properties.

  5. Water Based Phase Change Material Heat Exchanger Development

    Science.gov (United States)

    Hansen, Scott W.; Sheth, Ribik B.; Atwell, Matt; Cheek, Ann; Agarwal, Muskan; Hong, Steven; Patel, Aashini,; Nguyen, Lisa; Posada, Luciano

    2014-01-01

    In a cyclical heat load environment such as low Lunar orbit, a spacecraft’s radiators are not sized to reject the full heat load requirement. Traditionally, a supplemental heat rejection device (SHReD) such as an evaporator or sublimator is used to act as a “topper” to meet the additional heat rejection demands. Utilizing a Phase Change Material (PCM) heat exchanger (HX) as a SHReD provides an attractive alternative to evaporators and sublimators as PCM HXs do not use a consumable, thereby leading to reduced launch mass and volume requirements. Studies conducted in this paper investigate utilizing water’s high latent heat of formation as a PCM, as opposed to traditional waxes, and corresponding complications surrounding freezing water in an enclosed volume. Work highlighted in this study is primarily visual and includes understanding ice formation, freeze front propagation, and the solidification process of water/ice. Various test coupons were constructed of copper to emulate the interstitial pin configuration (to aid in conduction) of the proposed water PCM HX design. Construction of a prototypic HX was also completed in which a flexible bladder material and interstitial pin configurations were tested. Additionally, a microgravity flight was conducted where three copper test articles were frozen continuously during microgravity and 2-g periods and individual water droplets were frozen during microgravity.

  6. Phase Change Material Heat Sink for an ISS Flight Experiment

    Science.gov (United States)

    Quinn, Gregory; Stieber, Jesse; Sheth, Rubik; Ahlstrom, Thomas

    2015-01-01

    A flight experiment is being constructed to utilize the persistent microgravity environment of the International Space Station (ISS) to prove out operation of a microgravity compatible phase change material (PCM) heat sink. A PCM heat sink can help to reduce the overall mass and volume of future exploration spacecraft thermal control systems (TCS). The program is characterizing a new PCM heat sink that incorporates a novel phase management approach to prevent high pressures and structural deformation that often occur with PCM heat sinks undergoing cyclic operation in microgravity. The PCM unit was made using brazed aluminum construction with paraffin wax as the fusible material. It is designed to be installed into a propylene glycol and water cooling loop, with scaling consistent with the conceptual designs for the Orion Multipurpose Crew Vehicle. This paper reports on the construction of the PCM heat sink and on initial ground test results conducted at UTC Aerospace Systems prior to delivery to NASA. The prototype will be tested later on the ground and in orbit via a self-contained experiment package developed by NASA Johnson Space Center to operate in an ISS EXPRESS rack.

  7. Effect of water-ice phase change on thermal performance of building materials

    Science.gov (United States)

    Kočí, Václav; Černý, Robert

    2016-07-01

    The effect of water ice-phase change on thermal performance of integrated building material is investigated in this paper. As a characteristic construction, simple external wall made of aerated autoclaved concrete was assumed which was exposed to dynamic climatic condition of Šerák, Czech Republic. The computational modelling of hygrothermal performance was carried out using computer codes HEMOT and SIFEL that work on the basis of finite element method. The effect of phase change was taken into account by fixed-domain method, when experimentally determined effective specific heat capacity was used as a material parameter. It comprises also the effect of heat consumption and heat release that accompany the water-ice phase change. Comparing to the results with specific heat capacity, the effect of phase change on thermal performance could be quantified. The results showed that temperature fields can differ more than 6 °C. Additionally, the amount energy transported through the wall may be higher up to 4 %. This confirmed, that the effect water-ice phase change should be included in all the relevant energy calculations.

  8. Materials aspects of integrated high-Tc dc-SQUID magnetometer fabrication

    NARCIS (Netherlands)

    Hilgenkamp, J.W.M.; IJsselsteijn, R.P.J.; Rijnders, A.J.H.M.; Tavares, P.A.C.; Flokstra, J.; Rogalla, H.

    1993-01-01

    An integrated high Tc dc-SQUID magnetometer is being developed. It has in total 10 layers of five different materials. Various materials aspects of the fabrication process will be discussed, especially the smoothness of the films and the techniques to obtain smooth edges. Cross-overs and superconduc

  9. Smart interface materials integrated with microfluidics for on-demand local capture and release of cells.

    Science.gov (United States)

    Gurkan, Umut Atakan; Tasoglu, Savas; Akkaynak, Derya; Avci, Oguzhan; Unluisler, Sebnem; Canikyan, Serli; Maccallum, Noah; Demirci, Utkan

    2012-09-01

    Stimuli responsive, smart interface materials are integrated with microfluidic technologies creating new functions for a broad range of biological and clinical applications by controlling the material and cell interactions. Local capture and on-demand local release of cells are demonstrated with spatial and temporal control in a microfluidic system.

  10. A changing climate: impacts on human exposures to O3 using an integrated modeling methodology

    Science.gov (United States)

    Predicting the impacts of changing climate on human exposure to air pollution requires future scenarios that account for changes in ambient pollutant concentrations, population sizes and distributions, and housing stocks. An integrated methodology to model changes in human exposu...

  11. Research on phase-change material building mass applied in the air-conditioning field

    Institute of Scientific and Technical Information of China (English)

    YANQuanying

    2003-01-01

    Phase-change material building mass contains phase-change matenals. It can decrease air-conditioning load and indoor temperature fluctuations, and improve comfort degree in summer because of thermal storage property of phase-change material. Thereby, the scale, initial investment and operational cost of air-conditioning system decrease effectively. The indoor surroundings improve. In this paper, suitable phase-change material used in architecture and combination mode between phase change material and architectural material were studied. By considering the properties of materials, such as phase-change temperature, phase-change latent heat, thermal conductivity and expansion coefficient, phase-change materials were selected and evaluated. Combination mode between phase-change material and architectural material were provided. The influence of phase-change material structure on thermal performance in room and energy-saving effect were analyzed and compared with traditional structure without phase-change material. It is proved that phase-change material structure is feasible in the practical engineenng. These provide the basis for developing phase-change material building mass.

  12. Lorenzo Lotto's painting materials: an integrated diagnostic approach

    Science.gov (United States)

    Amadori, Maria Letizia; Poldi, Gianluca; Barcelli, Sara; Baraldi, Pietro; Berzioli, Michela; Casoli, Antonella; Marras, Susanna; Pojana, Giulio; Villa, Giovanni C. F.

    2016-07-01

    This paper presents the results of a comprehensive diagnostic investigation carried out on five paintings (three wood panels and two paintings on canvas) by Lorenzo Lotto, one of the most significant artists of the Italian Renaissance in the first half of 16th century. The paintings considered belong to 1508-1522 period, corresponding to the most significant years of Lotto's evolution. A wide array of non-invasive (reflectance spectrometry and X-ray fluorescence) and micro-invasive analytical techniques (optical microscopy, scanning electron microscopy with energy dispersive spectroscopy, micro-FTIR spectroscopy, micro-Raman spectroscopy, gas chromatography coupled with mass spectrometry and high performance liquid chromatography coupled with photodiode array detection and mass spectrometry) were applied in order to provide a large set of significant data, limiting as much as possible the sampling. This study has proved that Lotto's painting palette was typical of Venetian practice of that period, but some significant peculiarities emerged: the use of two kinds of red lakes, the addition of calcium carbonate and colourless powdered glass, the latter frequently found in pictorial and ground layers. Moreover, the integrated investigation showed that Lotto's technique was sometimes characterized by the use of coloured priming and multi-layer sequences with complex mixtures. Chromatographic analyses allowed to identify in all specimens: azelaic, palmitic and stearic acids, generally referring to the presence of drying oils. The extension of additional non-invasive examination to about 50 paintings by the same author, spanning from 1505 to around 1556, helped to verify the evolution in the use of some pigments, such as the yellow ones, where Pb-Sb yellow was used alongside Pb-Sn yellow.

  13. Integration, Identity and Participation in a Changing Europe

    Directory of Open Access Journals (Sweden)

    Marius Tătar

    2010-12-01

    Full Text Available The paper analyzes the prospects of building European identity in the changing environment of the EU enlargements. Drawing on data from Eurobarometer surveys, the study specifically looks at citizens’ perceptions and images of EU and their availability to participate in European affairs. The article points out different views about the meanings and expectations regarding the EU project. Although both national and international contexts play a significant role in fostering specific representations of EU, there is no clear-cut divide between the citizens of “old” and “new” Member States (MS. Instead, one can notice a more complex picture in terms of identification with the EU. In general, people from different MS tend to feel on average more attachment to their country (and sometimes to their own village/town/city than to the EU. Moreover, individuals from “old” MS do not necessarily have higher levels of attachment to the symbols of EU than those living in “new” MS. In addition, the level of effective knowledge on how EU actually works remains at relatively low rates throughout Europe, regardless of a country’s date of accession to the EU. Consequently, the socialization effects of the European integration process seem to remain weak in terms of fostering the emergence of European identity.

  14. The application of J integral to measure cohesive laws in materials undergoing large scale yielding

    DEFF Research Database (Denmark)

    Sørensen, Bent F.; Goutianos, Stergios

    2015-01-01

    We explore the possibility of determining cohesive laws by the J-integral approach for materials having non-linear stress-strain behaviour (e.g. polymers and composites) by the use of a DCB sandwich specimen, consisting of stiff elastic beams bonded to the non-linear test material, loaded with pure...... bending moments. For a wide range of parameters of the non-linear material, the plastic unloading during crack extension is small, resulting in J integral values (fracture resistance) that deviate maximum 15% from the work of the cohesive traction. Thus the method can be used to extract the cohesive laws...... directly from experiments without any presumption about their shape. Finally, the DCB sandwich specimen was also analysed using the I integral to quantify the overestimation of the steady-state fracture resistance obtained using the J integral based method....

  15. Optimization on microlattice materials for sound absorption by an integrated transfer matrix method.

    Science.gov (United States)

    Cai, Xiaobing; Yang, Jun; Hu, Gengkai

    2015-04-01

    Materials with well-defined microlattice structures are superlight, stable, and thus bear great potential in sound absorption. An integrated transfer matrix method (TMM) is proposed to evaluate the sound absorbing efficiency of these lattice materials, in which a massive number of micropores are densely placed. A comparison between integrated TMM and conventional TMM reveals that the proposed approach offers better predictions on sound absorption of microlattice. This approach is then employed to optimize the microlattice material to determine the best pore and porosity that lead to maximum absorbing efficiency capability and minimum required thickness to attain a target sound absorption.

  16. Phase Change Material Based Accumulation Panels in Combination with Renewable Energy Sources and Thermoelectric Cooling

    Directory of Open Access Journals (Sweden)

    Jan Skovajsa

    2017-01-01

    Full Text Available The article deals with the use of modern materials and technologies that can improve the thermal comfort in buildings. The article describes the design and usage of a special accumulation device, which is composed of thermal panels based on phase change materials (PCMs. The thermal panels have an integrated tube heat exchanger and heating foils. The technology can be used as a passive or active system for heating and cooling. It is designed as a “green technology”, so it is able to use renewable energy sources, e.g., photovoltaic (PV panels, solar thermal collectors and heat pumps. Moreover, an interesting possibility is the ability to use thermoelectric coolers. In the research, measurements of the different operating modes were made, and the results are presented in the text. The measurement approves that the technology improves the thermal capacity of the building, and it is possible to use it for active heating and cooling.

  17. Atomistic simulation study of the effect of martensitic transformation volume change on crack-tip material evolution and fracture toughness

    Energy Technology Data Exchange (ETDEWEB)

    Grujicic, M. [Clemson Univ., SC (United States). Dept. of Mechanical Engineering; Lai, S.G. [Clemson Univ., SC (United States). Dept. of Mechanical Engineering; Gumbsch, P. [Max Planck-Institut fur Metallforshung Institut fuer Werstoffwissenshaft, Seestrasse 92, D-7000 Stuttgart I (Germany)

    1997-07-15

    The effect of the sign of the F.C.C.{yields}B.C.C. martensitic transformation volume change in Fe-20Ni on material evolution in a region surrounding the crack tip and the accompanying change in the fracture resistance of the material have been investigated using molecular dynamics simulations. The interaction between atoms has been modeled using the embedded atom method (EAM) interatomic potentials. To obtain both the positive and the negative values of the transformation volume change, small adjustments had to be made in the EAM functions. These changes did not significantly affect of the key materials properties, such as the relative thermodynamic stability of the F.C.C. and B.C.C. structures, elastic constants, (11 anti 2){sub bcc} twin boundary energy, (10 anti 1){sub fcc}/(1 anti 21){sub bcc} interfacial energy, etc. The simulation results show that the sign of the transformation volume change has a profound effect on the material evolution and the path of the advancing crack. When the volume change is negative, the region ahead of the crack tip undergoes the transformation only after the other regions around the crack tip have already transformed. The crack tip undergoes a significant blunting and tends to stay on the original crack plane. In sharp contrast, when the volume change is positive, the region ahead of the crack tip transforms first and significant decohesion along the F.C.C./B.C.C. interfaces takes place. Consequently the crack tends to branch out. The effect of material evolution at the crack tip on the ability of the material to withstand further fracture has been quantified by calculating the Eshelby`s F{sub 1} conservation integral. The sign of the transformation volume change is found to have a major effect on the change of the F{sub 1} integral with the simulation time. (orig.)

  18. Hybrid materials science: a promised land for the integrative design of multifunctional materials

    Science.gov (United States)

    Nicole, Lionel; Laberty-Robert, Christel; Rozes, Laurence; Sanchez, Clément

    2014-05-01

    For more than 5000 years, organic-inorganic composite materials created by men via skill and serendipity have been part of human culture and customs. The concept of ``hybrid organic-inorganic'' nanocomposites exploded in the second half of the 20th century with the expansion of the so-called ``chimie douce'' which led to many collaborations between a large set of chemists, physicists and biologists. Consequently, the scientific melting pot of these very different scientific communities created a new pluridisciplinary school of thought. Today, the tremendous effort of basic research performed in the last twenty years allows tailor-made multifunctional hybrid materials with perfect control over composition, structure and shape. Some of these hybrid materials have already entered the industrial market. Many tailor-made multiscale hybrids are increasingly impacting numerous fields of applications: optics, catalysis, energy, environment, nanomedicine, etc. In the present feature article, we emphasize several fundamental and applied aspects of the hybrid materials field: bioreplication, mesostructured thin films, Lego-like chemistry designed hybrid nanocomposites, and advanced hybrid materials for energy. Finally, a few commercial applications of hybrid materials will be presented.

  19. Hybrid materials science: a promised land for the integrative design of multifunctional materials.

    Science.gov (United States)

    Nicole, Lionel; Laberty-Robert, Christel; Rozes, Laurence; Sanchez, Clément

    2014-06-21

    For more than 5000 years, organic-inorganic composite materials created by men via skill and serendipity have been part of human culture and customs. The concept of "hybrid organic-inorganic" nanocomposites exploded in the second half of the 20th century with the expansion of the so-called "chimie douce" which led to many collaborations between a large set of chemists, physicists and biologists. Consequently, the scientific melting pot of these very different scientific communities created a new pluridisciplinary school of thought. Today, the tremendous effort of basic research performed in the last twenty years allows tailor-made multifunctional hybrid materials with perfect control over composition, structure and shape. Some of these hybrid materials have already entered the industrial market. Many tailor-made multiscale hybrids are increasingly impacting numerous fields of applications: optics, catalysis, energy, environment, nanomedicine, etc. In the present feature article, we emphasize several fundamental and applied aspects of the hybrid materials field: bioreplication, mesostructured thin films, Lego-like chemistry designed hybrid nanocomposites, and advanced hybrid materials for energy. Finally, a few commercial applications of hybrid materials will be presented.

  20. A change of scale formula for Wiener integrals on abstract Wiener spaces

    Directory of Open Access Journals (Sweden)

    Il Yoo

    1994-01-01

    Full Text Available In this paper we obtain a change of scale formula for Wiener integrals on abstract Wiener spaces. This formula is shown to hold for many classes of functions of interest in Feynman integration theory and quantum mechanics.

  1. Continued Water-Based Phase Change Material Heat Exchanger Development

    Science.gov (United States)

    Hansen, Scott W.; Sheth, Rubik B.; Poynot, Joe; Giglio, Tony; Ungar, Gene K.

    2015-01-01

    In a cyclical heat load environment such as low Lunar orbit, a spacecraft's radiators are not sized to meet the full heat rejection demands. Traditionally, a supplemental heat rejection device (SHReD) such as an evaporator or sublimator is used to act as a "topper" to meet the additional heat rejection demands. Utilizing a Phase Change Material (PCM) heat exchanger (HX) as a SHReD provides an attractive alternative to evaporators and sublimators as PCM HX's do not use a consumable, thereby leading to reduced launch mass and volume requirements. In continued pursuit of water PCM HX development two full-scale, Orion sized water-based PCM HX's were constructed by Mezzo Technologies. These HX's were designed by applying prior research on freeze front propagation to a full-scale design. Design options considered included bladder restraint and clamping mechanisms, bladder manufacturing, tube patterns, fill/drain methods, manifold dimensions, weight optimization, and midplate designs. Two units, Units A and B, were constructed and differed only in their midplate design. Both units failed multiple times during testing. This report highlights learning outcomes from these tests and are applied to a final sub-scale PCM HX which is slated to be tested on the ISS in early 2017.

  2. Experimental Investigation of Ice Phase Change Material Heat Exchangers

    Science.gov (United States)

    Leimkuehler, Thomas O.; Stephan, Ryan A.

    2012-01-01

    Phase change materials (PCM) may be useful for spacecraft thermal control systems that involve cyclical heat loads or cyclical thermal environments. Thermal energy can be stored in the PCM during peak heat loads or in adverse thermal environments. The stored thermal energy can then be released later during minimum heat loads or in more favorable thermal environments. This can result in a decreased turndown ratio for the radiator and a reduced system mass. The use of water as a PCM rather than the more traditional paraffin wax has the potential for significant mass reduction since the latent heat of formation of water is approximately 70% greater than that of wax. One of the potential drawbacks of using ice as a PCM is its potential to rupture its container as water expands upon freezing. In order to develop a space qualified ice PCM heat exchanger, failure mechanisms must first be understood. Therefore, a methodical experimental investigation has been undertaken to demonstrate and document specific failure mechanisms due to ice expansion in the PCM. A number of ice PCM heat exchangers were fabricated and tested. Additionally, methods for controlling void location in order to reduce the risk of damage due to ice expansion were investigated. This paper presents an overview of the results of this investigation from the past three years.

  3. Thermal analysis of a building brick containing phase change material

    Energy Technology Data Exchange (ETDEWEB)

    Alawadhi, E.M. [Kuwait Univ., Safat (Kuwait). Dept. of Mechanical Engineering

    2008-07-01

    This paper presents the thermal analysis of a building brick containing phase change material (PCM) to be used in hot climates. The objective of using the PCM is to utilize its high latent heat of fusion to reduce the heat gain by absorbing the heat in the bricks through the melting process before it reaches the indoor space. The considered model consists of bricks with cylindrical holes filled with PCM. The problem is solved in a two-dimensional space using the finite element method. The thermal effectiveness of the proposed brick-PCM system is evaluated by comparing the heat flux at the indoor surface to a wall without the PCM during typical working hours. A paramedic study is conducted to assess the effect of different design parameters, such as the PCM's quantity, type, and location in the brick. The results indicate that the heat gain is significantly reduced when the PCM is incorporated into the brick, and increasing the quantity of the PCM has a positive effect. PCM cylinders located at the centerline of the bricks shows the best performance. (author)

  4. Free-cooling of buildings with phase change materials

    Energy Technology Data Exchange (ETDEWEB)

    Zalba, B.; Marin, J.M. [Universidad de Zaragoza Maria de Luna (Spain). Departamento de Ingenieria Mecanica; Cabeza, L.F. [Universitat de Lleida (Spain). Departamento d' Informatica i Eng. Industrial; Mehling, H. [ZAE Bayern, Abt. 1 Energy Conversion and Storage, Garching (Germany)

    2004-12-01

    In this paper, the application of phase change materials (PCM) in free-cooling systems is studied. Free-cooling is understood as a means to store outdoors coolness during the night, to supply indoors cooling during the day. The use of PCMs is suitable because of the small temperature difference between day indoors and night outdoors. An installation that allows testing the performance of PCMs in such systems was designed and constructed. The main influence parameters like ratio of energy/volume in the encapsulates, load/unload rate of the storage, and cost of the installation were determined, and experiments were performed following the design of experiments strategy. The statistical analysis showed that the effects with significant influence in the solidification process are the thickness of the encapsulation, the inlet temperature of the air, the air flow, and the interaction thickness x temperature. For the melting process the same holds, but the inlet air temperature had a higher influence than the thickness of the encapsulation. With the empirical model developed in this work, a real free-cooling system was designed and economically evaluated. (author)

  5. An integrated computational materials engineering method for woven carbon fiber composites preforming process

    Science.gov (United States)

    Zhang, Weizhao; Ren, Huaqing; Wang, Zequn; Liu, Wing K.; Chen, Wei; Zeng, Danielle; Su, Xuming; Cao, Jian

    2016-10-01

    An integrated computational materials engineering method is proposed in this paper for analyzing the design and preforming process of woven carbon fiber composites. The goal is to reduce the cost and time needed for the mass production of structural composites. It integrates the simulation methods from the micro-scale to the macro-scale to capture the behavior of the composite material in the preforming process. In this way, the time consuming and high cost physical experiments and prototypes in the development of the manufacturing process can be circumvented. This method contains three parts: the micro-scale representative volume element (RVE) simulation to characterize the material; the metamodeling algorithm to generate the constitutive equations; and the macro-scale preforming simulation to predict the behavior of the composite material during forming. The results show the potential of this approach as a guidance to the design of composite materials and its manufacturing process.

  6. Integrating climate change into governance at the municipal scale

    DEFF Research Database (Denmark)

    Wejs, Anja

    2014-01-01

    traditions and perceptions. This article examines dif- ferent approaches to CC governance and the institutional dynamics that occur in the integration process within eight Danish municipalities in the initial phase of integrating CC. The results show three different governance approaches related to climate...

  7. Study of improving the thermal response of a construction material containing a phase change material

    Science.gov (United States)

    Laaouatni, A.; Martaj, N.; Bennacer, R.; Elomari, M.; El Ganaoui, M.

    2016-09-01

    The use of phase change materials (PCMs) for improving the thermal comfort in buildings has become an attractive application. This solution contributes to increasing the thermal inertia of the building envelope and reducing power consumption. A building element filled with a PCM and equipped with ventilation tubes is proposed, both for increasing inertia and contributing to refreshing building envelope. A numerical simulation is conducted by the finite element method in COMSOL Multiphysics, which aims to test the thermal behaviour of the developed solution. An experimental study is carried out on a concrete block containing a PCM with ventilation tubes. The objective is to see the effect of PCM coupled with ventilation on increasing the inertia of the block. The results show the ability of this new solution to ensure an important thermal inertia of a building.

  8. Integrated energy planning: Strategies to mitigate climate change

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, Johnny N; Sheffield, John W [University of Missouri-Rolla (United States)

    1997-07-01

    The framework convention on climate change, signed by more than 150 governments worldwide in June 1992, calls on parties to the convention undertaken inventories of national sources and sinks of greenhouse gases and to develop plans for responding to climate change. The energy sector is comprised of the major energy demand sectors (industry, residential and commercial, transport and agriculture), and the energy supply sector, which consists of resource extraction, conversion, and delivery of energy products. Greenhouse Gas (GHG) emissions occur at various points in the sector, from resource extraction to end use application, and accordingly, options for mitigation exist at various points. In most countries, will be a major focus of GHG mitigation analysis. The primary focus of this paper is on the identification of strategies that can mitigate climate changes on the basis of integrated energy planing analysis. The overall approach follows a methodology developed by the U.S. Country Studies Program under the framework of the Convention's commitments. It involves the development of scenarios based on energy uses and evaluation of specific technologies that can satisfy demands for energy services. One can compare technologies based on their relative cost to achieve a unit of GHG reduction and other features of interest. This approach gives equal weight to both energy supply and energy demand options. A variety of screening criteria including indicators of cost-effectiveness as well as non-economic analysis concerns, can be used to identify and assess promising options, which can then be combined to create one or more scenarios. Mitigation scenarios are evaluated against the backdrop of a baseline scenario, which simulates assumed to take place in the absence of mitigation efforts. Mitigation scenarios can be designed to meet specific emission reduction targets or to simulate the effect of specific policy inventions. The paper ends with an application using a

  9. Interdisciplinary Climate Change Curriculum Materials based on the Next Generation Science Standards and The Earth Charter

    Science.gov (United States)

    Barbosa, A.; Robertson, W. H.

    2013-12-01

    In the 2012, the National Research Council (NRC) of the National Academies' reported that one of the major issues associated with the development of climate change curriculum was the lack of interdisciplinary materials that also promoted a correlation between science standards and content. Therefore, in order to respond to this need, our group has developed an interdisciplinary climate change curriculum that has had as its fundamental basis the alignment with the guidelines presented by the Next Generation Science Standards (NGSS) and the ones presented by the international document entitled The Earth Charter. In this regards, while the alignment with NGSS disciplinary core ideas, cross-concepts and students' expectations intended to fulfill the need for the development of climate change curriculum activities that were directly associated with the appropriate set of NGSS guidelines, the alignment with The Earth Charter document intended to reinforce the need the for the integration of sociological, philosophical and intercultural analysis of the theme 'climate change'. Additionally, our curriculum was also developed as part of a collaborative project between climate scientists and engineers, who are responsible for the development of a Regional Arctic Simulation Model (RASM). Hence, another important curriculum constituent was the feedback, suggestions and reviews provided by these professionals, who have also contributed to these pedagogical materials' scientific accuracy by facilitating the integration of datasets and visualizations developed by RASM. Furthermore, our group has developed a climate change curriculum for two types of audience: high school and early undergraduate students. Each curriculum unit is divided into modules and each module contains a set of lesson plans. The topics selected to compose each unit and module were designated according to the surveys conducted with scientists and engineers involved with the development of the climate change

  10. Diamond as a material for monolithically integrated optical and optomechanical devices

    CERN Document Server

    Rath, Patrik; Nebel, Christoph; Pernice, Wolfram H P

    2016-01-01

    Diamond provides superior optical and mechanical material properties, making it a prime candidate for the realization of integrated optomechanical circuits. Because diamond sub- strates have matured in size, efficient nanostructuring methods can be used to realize full-scale integrated devices. Here we review optical and mechanical resonators fab- ricated from polycrystalline as well as single crystalline diamond. We present relevant material properties with respect to implementing optomechanical devices and compare them with other material systems. We give an overview of diamond integrated optomechanical circuits and present the optical readout mechanism and the actuation via optical or electrostatic forces that have been implemented to date. By combining diamond nanophotonic circuits with superconducting nanowires single photons can be efficiently detected on such chips and we outline how future single photon optomechanical circuits can be realized on this platform.

  11. Integrated Computational Materials Engineering (ICME) for Third Generation Advanced High-Strength Steel Development

    Energy Technology Data Exchange (ETDEWEB)

    Savic, Vesna; Hector, Louis G.; Ezzat, Hesham; Sachdev, Anil K.; Quinn, James; Krupitzer, Ronald; Sun, Xin

    2015-06-01

    This paper presents an overview of a four-year project focused on development of an integrated computational materials engineering (ICME) toolset for third generation advanced high-strength steels (3GAHSS). Following a brief look at ICME as an emerging discipline within the Materials Genome Initiative, technical tasks in the ICME project will be discussed. Specific aims of the individual tasks are multi-scale, microstructure-based material model development using state-of-the-art computational and experimental techniques, forming, toolset assembly, design optimization, integration and technical cost modeling. The integrated approach is initially illustrated using a 980 grade transformation induced plasticity (TRIP) steel, subject to a two-step quenching and partitioning (Q&P) heat treatment, as an example.

  12. 47 CFR 1.5006 - Procedure for notifying Commission of material change in facts.

    Science.gov (United States)

    2010-10-01

    ... change in facts. 1.5006 Section 1.5006 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL... material change in facts. If there is any material change in facts that may affect an ETC's eligibility for..., within 30 days of the change in fact, either: (a) Apply to the Commission for a new determination of...

  13. Insights from the 3rd World Congress on Integrated Computational Materials Engineering

    Science.gov (United States)

    Howe, D.; Goodlet, B.; Weaver, J.; Spanos, G.

    2016-05-01

    The 3rd World Congress on Integrated Computational Materials Engineering (ICME) was a forum for presenting the "state-of-the-art" in the ICME discipline, as well as for charting a path for future community efforts. The event concluded with in an interactive panel-led discussion that addressed such topics as integrating efforts between experimental and computational scientists, uncertainty quantification, and identifying the greatest challenges for future workforce preparation. This article is a summary of this discussion and the thoughts presented.

  14. Ultrafast characterization of phase-change material crystallization properties in the melt-quenched amorphous phase.

    Science.gov (United States)

    Jeyasingh, Rakesh; Fong, Scott W; Lee, Jaeho; Li, Zijian; Chang, Kuo-Wei; Mantegazza, Davide; Asheghi, Mehdi; Goodson, Kenneth E; Wong, H-S Philip

    2014-06-11

    Phase change materials are widely considered for application in nonvolatile memories because of their ability to achieve phase transformation in the nanosecond time scale. However, the knowledge of fast crystallization dynamics in these materials is limited because of the lack of fast and accurate temperature control methods. In this work, we have developed an experimental methodology that enables ultrafast characterization of phase-change dynamics on a more technologically relevant melt-quenched amorphous phase using practical device structures. We have extracted the crystallization growth velocity (U) in a functional capped phase change memory (PCM) device over 8 orders of magnitude (10(-10) programmed PCM devices at very high heating rates (>10(8) K/s), which reveals the extreme fragility of Ge2Sb2Te5 in its supercooled liquid phase. Furthermore, these crystallization properties were studied as a function of device programming cycles, and the results show degradation in the cell retention properties due to elemental segregation. The above experiments are enabled by the use of an on-chip fast heater and thermometer called as microthermal stage (MTS) integrated with a vertical phase change memory (PCM) cell. The temperature at the PCM layer can be controlled up to 600 K using MTS and with a thermal time constant of 800 ns, leading to heating rates ∼10(8) K/s that are close to the typical device operating conditions during PCM programming. The MTS allows us to independently control the electrical and thermal aspects of phase transformation (inseparable in a conventional PCM cell) and extract the temperature dependence of key material properties in real PCM devices.

  15. Integrated earth system studies. Joint research efforts of global change

    Energy Technology Data Exchange (ETDEWEB)

    McKeown, R.; Kittel, T.G.F.; Schimel, D.S. [National Center for Atmospheric Research, Boulder, CO (United States)] [and others

    1995-06-01

    Analysis of changes to ecosystem C and N pools and fluxes from different natural and managed ecosystems across the continental US was conducted using the CENTURY ecosystem model. Ecosystem dynamics in responses to climate or land use changes do not immediately equilibrate to new environmental conditions. A variety of inherent properties of a biological system has built-in resistance to change in the environment. This includes pools of soil organic matter that resist changes in short-term climate signals, plant components related to ecosystem structure or biogeochemical properties. As climate changes, these pools serve as buffers against immediate changes in the biogeochemical response of the system. Our analysis indicate that certain of the managed ecosystems are more buffered to changes in the climate system than the natural systems; while others appear to be equally sensitive to these changes in rainfall and temperature.

  16. Model of Integration of Material Flow Control System with MES/ERP System via Cloud Computing

    Directory of Open Access Journals (Sweden)

    Peter Peniak

    2014-05-01

    Full Text Available This article deals with a model of application gateway for integration of Material Flow Control System with ERP/MES systems, which are provided by Cloud Computing and Software as Service delivery model. The developed gateway interface is supposed to cover fundamental requirements of production systems for customization and real-time control of material flow within manufacturing processes. Designed solution has been tested and evaluated for High Bay Storage system in a real production environment

  17. Socio-materiality as lens to study IT driven change

    DEFF Research Database (Denmark)

    Carugati, Andrea; Morelli, Chiara; Giangreco, Antonio

    2010-01-01

    This paper reports the findings of a research into change during the constitution of an IT Group. Our main findings show that when an IT company acquires two similar companies, IT becomes a central part of the change program, differing from other change cases where IT is considered a peripheral...

  18. Integrated energy planning: Strategies to mitigate climate change

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, Johnny N; Sheffield, John W [University of Missouri-Rolla (United States)

    1997-07-01

    The framework convention on climate change, signed by more than 150 governments worldwide in June 1992, calls on parties to the convention undertaken inventories of national sources and sinks of greenhouse gases and to develop plans for responding to climate change. The energy sector is comprised of the major energy demand sectors (industry, residential and commercial, transport and agriculture), and the energy supply sector, which consists of resource extraction, conversion, and delivery of energy products. Greenhouse Gas (GHG) emissions occur at various points in the sector, from resource extraction to end use application, and accordingly, options for mitigation exist at various points. In most countries, will be a major focus of GHG mitigation analysis. The primary focus of this paper is on the identification of strategies that can mitigate climate changes on the basis of integrated energy planing analysis. The overall approach follows a methodology developed by the U.S. Country Studies Program under the framework of the Convention's commitments. It involves the development of scenarios based on energy uses and evaluation of specific technologies that can satisfy demands for energy services. One can compare technologies based on their relative cost to achieve a unit of GHG reduction and other features of interest. This approach gives equal weight to both energy supply and energy demand options. A variety of screening criteria including indicators of cost-effectiveness as well as non-economic analysis concerns, can be used to identify and assess promising options, which can then be combined to create one or more scenarios. Mitigation scenarios are evaluated against the backdrop of a baseline scenario, which simulates assumed to take place in the absence of mitigation efforts. Mitigation scenarios can be designed to meet specific emission reduction targets or to simulate the effect of specific policy inventions. The paper ends with an application using a

  19. Integrating Materials, Manufacturing, Design and Validation for Sustainability in Future Transport Systems

    Science.gov (United States)

    Price, M. A.; Murphy, A.; Butterfield, J.; McCool, R.; Fleck, R.

    2011-05-01

    The predictive methods currently used for material specification, component design and the development of manufacturing processes, need to evolve beyond the current `metal centric' state of the art, if advanced composites are to realise their potential in delivering sustainable transport solutions. There are however, significant technical challenges associated with this process. Deteriorating environmental, political, economic and social conditions across the globe have resulted in unprecedented pressures to improve the operational efficiency of the manufacturing sector generally and to change perceptions regarding the environmental credentials of transport systems in particular. There is a need to apply new technologies and develop new capabilities to ensure commercial sustainability in the face of twenty first century economic and climatic conditions as well as transport market demands. A major technology gap exists between design, analysis and manufacturing processes in both the OEMs, and the smaller companies that make up the SME based supply chain. As regulatory requirements align with environmental needs, manufacturers are increasingly responsible for the broader lifecycle aspects of vehicle performance. These include not only manufacture and supply but disposal and re-use or re-cycling. In order to make advances in the reduction of emissions coupled with improved economic efficiency through the provision of advanced lightweight vehicles, four key challenges are identified as follows: Material systems, Manufacturing systems, Integrated design methods using digital manufacturing tools and Validation systems. This paper presents a project which has been designed to address these four key issues, using at its core, a digital framework for the creation and management of key parameters related to the lifecycle performance of thermoplastic composite parts and structures. It aims to provide capability for the proposition, definition, evaluation and demonstration of

  20. Explaining Changing Suicide Rates in Norway 1948-2004: The Role of Social Integration

    Science.gov (United States)

    Barstad, Anders

    2008-01-01

    Using Norway 1948-2004 as a case, I test whether changes in variables related to social integration can explain changes in suicide rates. The method is the Box-Jenkins approach to time-series analysis. Different aspects of family integration contribute significantly to the explanation of Norwegian suicide rates in this period. The estimated effect…

  1. Welded joints integrity analysis and optimization for fiber laser welding of dissimilar materials

    Science.gov (United States)

    Ai, Yuewei; Shao, Xinyu; Jiang, Ping; Li, Peigen; Liu, Yang; Liu, Wei

    2016-11-01

    Dissimilar materials welded joints provide many advantages in power, automotive, chemical, and spacecraft industries. The weld bead integrity which is determined by process parameters plays a significant role in the welding quality during the fiber laser welding (FLW) of dissimilar materials. In this paper, an optimization method by taking the integrity of the weld bead and weld area into consideration is proposed for FLW of dissimilar materials, the low carbon steel and stainless steel. The relationships between the weld bead integrity and process parameters are developed by the genetic algorithm optimized back propagation neural network (GA-BPNN). The particle swarm optimization (PSO) algorithm is taken for optimizing the predicted outputs from GA-BPNN for the objective. Through the optimization process, the desired weld bead with good integrity and minimum weld area are obtained and the corresponding microstructure and microhardness are excellent. The mechanical properties of the optimized joints are greatly improved compared with that of the un-optimized welded joints. Moreover, the effects of significant factors are analyzed based on the statistical approach and the laser power (LP) is identified as the most significant factor on the weld bead integrity and weld area. The results indicate that the proposed method is effective for improving the reliability and stability of welded joints in the practical production.

  2. Integrated Floodplain Management, Environmental Change, and Geomorphology: Problems and Prospects

    NARCIS (Netherlands)

    Hudson, Paul F; Middelkoop, Hans

    2015-01-01

    Recognition of the failure of old perspectives on river management and the need to enhance environmental sustainability has stimulated a new approach to river management over the past couple of decades. The manner that river restoration and integrated management are implemented, however, requires a

  3. How well do integrated assessment models simulate climate change?

    NARCIS (Netherlands)

    van Vuuren, D.P.; Lowe, J.; Stehfest, E.; Gohar, L.; Hof, Andries; Hope, C.; Warren, R.; Meinshausen, M.; Plattner, G.K.

    2011-01-01

    Integrated assessment models (IAMs) are regularly used to evaluate different policies of future emissions reductions. Since the global costs associated with these policies are immense, it is vital that the uncertainties in IAMs are quantified and understood. We first demonstrate the significant spre

  4. Task-Based Learning and Content and Language Integrated Learning Materials Design: Process and Product

    Science.gov (United States)

    Moore, Pat; Lorenzo, Francisco

    2015-01-01

    Content and language integrated learning (CLIL) represents an increasingly popular approach to bilingual education in Europe. In this article, we describe and discuss a project which, in response to teachers' pleas for materials, led to the production of a significant bank of task-based primary and secondary CLIL units for three L2s (English,…

  5. Effects of the Integrated Online Advance Organizer Teaching Materials on Students' Science Achievement and Attitude

    Science.gov (United States)

    Korur, Fikret; Toker, Sacip; Eryilmaz, Ali

    2016-01-01

    This two-group quasi-experimental study investigated the effects of the Online Advance Organizer Concept Teaching Material (ONACOM) integrated with inquiry teaching and expository teaching methods. Grade 7 students' posttest performances on the light unit achievement and light unit attitude tests controlled for gender, previous semester science…

  6. Exploring the Nutrient Release Potential of Organic Materials as Integrated Soil Fertility Management Components Using SAFERNAC

    NARCIS (Netherlands)

    Maro, G.P.; Mrema, J.P.; Msanya, B.M.; Janssen, B.H.; Teri, J.M.

    2014-01-01

    The aim of this study was to establish the nutrient release potential of different organic materials and assess their role in integrated soil fertility management for coffee using the new coffee yield model SAFERNAC. It involved an incubation experiment conducted at TaCRI Lyamungu Screenhouse for 18

  7. Integrating Molecular Computation and Material Production in an Artificial Subcellular Matrix

    DEFF Research Database (Denmark)

    Fellermann, Harold; Hadorn, Maik; Bönzli, Eva

    compartmentalized re- action compartments that interact and get delivered through vesicle trafficking. The European Commission funded project MatchIT (Matrix for Chemical IT) aims at creating an artificial cellular matrix that seamlessly integrates infor- mation processing and material production in much the same...

  8. Wettability changes in polyether impression materials subjected to immersion disinfection

    Directory of Open Access Journals (Sweden)

    Shweta Shetty

    2013-01-01

    Conclusion: Within the limitations of the study, 2% glutaraldehyde proved safe for 10 min of immersion disinfection while 0.05% iodophor holds promise as an effective disinfectant without affecting the wettability of the material.

  9. Experimental Investigation of Thermal Conductivity of Concrete Containing Micro-Encapsulated Phase Change Materials

    DEFF Research Database (Denmark)

    Pomianowski, Michal Zbigniew; Heiselberg, Per; Jensen, Rasmus Lund

    2011-01-01

    The aim of increasing the building internal heat storage capacity is to be able to store excessive heat gains and by that reduce indoor high temperature peaks and at the same time shift high heat loads to the low heat loads hours and to decrease cooling energy need. The concept presented in this ......The aim of increasing the building internal heat storage capacity is to be able to store excessive heat gains and by that reduce indoor high temperature peaks and at the same time shift high heat loads to the low heat loads hours and to decrease cooling energy need. The concept presented...... in this article utilizes integration of the concrete and the microencapsulated Phase Change Material (PCM). PCM has the ability to absorb and release significant amounts of heat at a specific temperature range. As a consequence of admixing PCM to the concrete, new thermal properties like thermal conductivity...

  10. Thermophysical and Mechanical Properties of Hardened Cement Paste with Microencapsulated Phase Change Materials for Energy Storage

    Directory of Open Access Journals (Sweden)

    Hongzhi Cui

    2014-12-01

    Full Text Available In this research, structural-functional integrated cement-based materials were prepared by employing cement paste and a microencapsulated phase change material (MPCM manufactured using urea-formaldehyde resin as the shell and paraffin as the core material. The encapsulation ratio of the MPCM could reach up to 91.21 wt%. Thermal energy storage cement pastes (TESCPs incorporated with different MPCM contents (5%, 10%, 15%, 20% and 25% by weight of cement were developed, and their thermal and mechanical properties were studied. The results showed that the total energy storage capacity of the hardened cement specimens with MPCM increased by up to 3.9-times compared with that of the control cement paste. The thermal conductivity at different temperature levels (35–36 °C, 55–56 °C and 72–74 °C decreased with the increase of MPCM content, and the decrease was the highest when the temperature level was 55–56 °C. Moreover, the compressive strength, flexural strength and density of hardened cement paste decreased with the increase in MPCM content linearly. Among the evaluated properties, the compressive strength of TESCPs had a larger and faster degradation with the increase of MPCM content.

  11. EDDA 1.0: integrated simulation of debris flow erosion, deposition and property changes

    Science.gov (United States)

    Chen, H. X.; Zhang, L. M.

    2015-03-01

    Debris flow material properties change during the initiation, transportation and deposition processes, which influences the runout characteristics of the debris flow. A quasi-three-dimensional depth-integrated numerical model, EDDA (Erosion-Deposition Debris flow Analysis), is presented in this paper to simulate debris flow erosion, deposition and induced material property changes. The model considers changes in debris flow density, yield stress and dynamic viscosity during the flow process. The yield stress of the debris flow mixture determined at limit equilibrium using the Mohr-Coulomb equation is applicable to clear water flow, hyper-concentrated flow and fully developed debris flow. To assure numerical stability and computational efficiency at the same time, an adaptive time stepping algorithm is developed to solve the governing differential equations. Four numerical tests are conducted to validate the model. The first two tests involve a one-dimensional debris flow with constant properties and a two-dimensional dam-break water flow. The last two tests involve erosion and deposition, and the movement of multi-directional debris flows. The changes in debris flow mass and properties due to either erosion or deposition are shown to affect the runout characteristics significantly. The model is also applied to simulate a large-scale debris flow in Xiaojiagou Ravine to test the performance of the model in catchment-scale simulations. The results suggest that the model estimates well the volume, inundated area, and runout distance of the debris flow. The model is intended for use as a module in a real-time debris flow warning system.

  12. EDDA: integrated simulation of debris flow erosion, deposition and property changes

    Directory of Open Access Journals (Sweden)

    H. X. Chen

    2014-11-01

    Full Text Available Debris flow material properties change during the initiation, transportation and deposition processes, which influences the runout characteristics of the debris flow. A quasi-three-dimensional depth-integrated numerical model, EDDA, is presented in this paper to simulate debris flow erosion, deposition and induced material property changes. The model considers changes in debris flow density, yield stress and dynamic viscosity during the flow process. The yield stress of debris flow mixture is determined at limit equilibrium using the Mohr–Coulomb equation, which is applicable to clear water flow, hyper-concentrated flow and fully developed debris flow. To assure numerical stability and computational efficiency at the same time, a variable time stepping algorithm is developed to solve the governing differential equations. Four numerical tests are conducted to validate the model. The first two tests involve a one-dimensional dam-break water flow and a one-dimensional debris flow with constant properties. The last two tests involve erosion and deposition, and the movement of multi-directional debris flows. The changes in debris flow mass and properties due to either erosion or deposition are shown to affect the runout characteristics significantly. The model is also applied to simulate a large-scale debris flow in Xiaojiagou Ravine to test the performance of the model in catchment-scale simulations. The results suggest that the model estimates well the volume, inundated area, and runout distance of the debris flow. The model is intended for use as a module in a real-time debris flow warning system.

  13. EDDA: integrated simulation of debris flow erosion, deposition and property changes

    Science.gov (United States)

    Chen, H. X.; Zhang, L. M.

    2014-11-01

    Debris flow material properties change during the initiation, transportation and deposition processes, which influences the runout characteristics of the debris flow. A quasi-three-dimensional depth-integrated numerical model, EDDA, is presented in this paper to simulate debris flow erosion, deposition and induced material property changes. The model considers changes in debris flow density, yield stress and dynamic viscosity during the flow process. The yield stress of debris flow mixture is determined at limit equilibrium using the Mohr-Coulomb equation, which is applicable to clear water flow, hyper-concentrated flow and fully developed debris flow. To assure numerical stability and computational efficiency at the same time, a variable time stepping algorithm is developed to solve the governing differential equations. Four numerical tests are conducted to validate the model. The first two tests involve a one-dimensional dam-break water flow and a one-dimensional debris flow with constant properties. The last two tests involve erosion and deposition, and the movement of multi-directional debris flows. The changes in debris flow mass and properties due to either erosion or deposition are shown to affect the runout characteristics significantly. The model is also applied to simulate a large-scale debris flow in Xiaojiagou Ravine to test the performance of the model in catchment-scale simulations. The results suggest that the model estimates well the volume, inundated area, and runout distance of the debris flow. The model is intended for use as a module in a real-time debris flow warning system.

  14. Therapeutic Enactment: Integrating Individual and Group Counseling Models for Change

    Science.gov (United States)

    Westwood, Marvin J.; Keats, Patrice A.; Wilensky, Patricia

    2003-01-01

    The purpose of this article is to introduce the reader to a group-based therapy model known as therapeutic enactment. A description of this multimodal change model is provided by outlining the relevant background information, key concepts related to specific change processes, and the differences in this model compared to earlier psychodrama…

  15. Driving behavioural change towards ecodesign integration: Nudging experiment in industry

    DEFF Research Database (Denmark)

    Brones, Fabien; Gyldendal Melberg, Morten; Monteiro de Carvalho, Marly

    2014-01-01

    of the current ecodesign programme, which may contribute to turn change strategies more effectively in complex business and human organisational situations, where management styles evolve and rely on more autonomous individuals and teams. Further research and application on sustainable changes should...... systemically consider individuals’ engagement, including behavioural aspects, interaction with project teams and higher level business organisations....

  16. Integrating ICT in Teacher Colleges - A Change Process

    Directory of Open Access Journals (Sweden)

    Noga Magen- Nagar

    2016-06-01

    Full Text Available The National Israeli Information and Communication Technology (ICT Program that called for the “adaption of the educational system to the 21st century”, has been implemented in Israel since 2010. The program’s purpose intended to introduce an ‘ICT culture’ in the educational system – pre-schools and lower-level schools, as well as in higher education institutions, including teachers colleges. Following this call, the current study is aimed at examining the integration of ICT in a teaching training college in the north of Israel, in the context of a technological-pedagogic setting, the ICT culture in the college, and how educators’ metaphorical sensations contribute to their use of ICT tools and to student training in an ICT environment. The second aim of the research was to identify the operating factors in the course of educators’ professional development that impact on the integration of advanced technologies in teaching. This mixed-methods study involved 120 educators. Through structural equation modelling, the findings show that educators’ familiarity and mastery of ICT tools influence use for teaching purposes, more so than personal feelings, the ICT culture, and the availability of the tools. Findings emphasize the need for promoting the integration of technology in teachers colleges as a learning organization, from a systemic view, which emphasizes the teacher educator’s personal-professional development.

  17. Integrating Media Production By Students Into Climate Change Education: Within and Beyond the Classroom

    Science.gov (United States)

    Rooney-Varga, J. N.; Brisk, A. A.; Grogan, M.; Ledley, T. S.

    2012-12-01

    Through the Climate Education in an Age of Media (CAM) Project (http://cleanet.org/cced_media/), we have developed approaches to integrate media production by students into climate change education in ways that are engaging, empowering, and can be readily adopted in a wide range of instructional environments. These approaches can be used to overcome many of the challenges that climate change education presents and provide a means to evoke experiential, affective, and social learning pathways. Video production combines many key twenty-first century literacy skills, including content research, writing, an understanding of the power of images and sounds, the ability to use that power, and the ability to manipulate, transform, and distribute digital media. Through collaboration, reflection, and visual expression of concepts, video production facilitates a deeper understanding of material and, potentially, shifts in mental models about climate change. Equally importantly, it provides a means to bridge formal and informal learning by enabling students to educate those beyond the classroom. We have piloted our approach in two intensive summer programs (2011 and 2012) for high school students, during which students learned about climate change science content in lessons that were paired with the production of short media pieces including animations, public service announcements, person-on-the-street interviews, mock trailers, mock news programs, and music videos. Two high school teachers were embedded in the program during the second year, providing feedback and assessment of the feasibility, accessibility, and utility of the approach. The programs culminated with students presenting and discussing their work at public screening events. The media lessons and climate change science content examples used in these programs form the backbone of a toolkit and professional development workshops for middle and high school teachers, in which teachers learn how to incorporate

  18. Integrated Methodology for Information System Change Control Based on Enterprise Architecture Models

    Directory of Open Access Journals (Sweden)

    Pirta Ruta

    2015-12-01

    Full Text Available The information system (IS change management and governance, according to the best practices, are defined and described in several international methodologies, standards, and frameworks (ITIL, COBIT, ValIT etc.. These methodologies describe IS change management aspects from the viewpoint of their particular enterprise resource management area. The areas are mainly viewed in a partly isolated environment, and the integration of the existing methodologies is insufficient for providing unified and controlled methodological support for holistic IS change management. In this paper, an integrated change management methodology is introduced. The methodology consists of guidelines for IS change control by integrating the following significant resource management areas – information technology (IT governance, change management and enterprise architecture (EA change management. In addition, the methodology includes lists of controls applicable at different phases. The approach is based on re-use and fusion of principles used by related methodologies as well as on empirical observations about typical IS change management mistakes in enterprises.

  19. Nastic Actuation: Electroosmotic Pumping for Shape-Changing Materials

    Science.gov (United States)

    2012-02-23

    G. E. Collins, "Integrated microfluidic device for solid-phase extraction coupled to micellar electrokinetic chromatography separation," Anal. Chem...pores. They were originally developed for lab-on-a-chip devices, with applications in chromatography [1-5] and solid phase extraction [6-8]. They...grafted monolithic columns for cation exchange chromatography of proteins and peptides," J. Chromatog. A, vol. 1216, pp. 6824-6830, 2009. [3] D. Lee

  20. Integral Transforms on a Function Space with Change of Scales Using Multivariate Normal Distributions

    Directory of Open Access Journals (Sweden)

    Dong Hyun Cho

    2016-01-01

    Full Text Available Using simple formulas for generalized conditional Wiener integrals on a function space which is an analogue of Wiener space, we evaluate two generalized analytic conditional Wiener integrals of a generalized cylinder function which is useful in Feynman integration theories and quantum mechanics. We then establish various integral transforms over continuous paths with change of scales for the generalized analytic conditional Wiener integrals. In these evaluation formulas and integral transforms we use multivariate normal distributions so that the orthonormalization process of projection vectors which are needed to establish the conditional Wiener integrals can be removed in the existing change of scale transforms. Consequently the transforms in the present paper can be expressed in terms of the generalized cylinder function itself.

  1. Offensive Speech in Educational Materials: Changing Words without Censorship

    Science.gov (United States)

    McGough, Sarah M.

    2007-01-01

    Background/Context: Diane Ravitch has focused on the extensive censorship occurring within the publication of school textbook and testing materials in her book, "The Language Police" (2003). This book, indicative of conservative frustrations with minority special interest groups, raises several key issues echoed throughout the larger educational…

  2. Entrainment of bed material by Earth-surface mass flows: review and reformulation of depth-integrated theory

    Science.gov (United States)

    Iverson, Richard M.; Chaojun Ouyang,

    2015-01-01

    Earth-surface mass flows such as debris flows, rock avalanches, and dam-break floods can grow greatly in size and destructive potential by entraining bed material they encounter. Increasing use of depth-integrated mass- and momentum-conservation equations to model these erosive flows motivates a review of the underlying theory. Our review indicates that many existing models apply depth-integrated conservation principles incorrectly, leading to spurious inferences about the role of mass and momentum exchanges at flow-bed boundaries. Model discrepancies can be rectified by analyzing conservation of mass and momentum in a two-layer system consisting of a moving upper layer and static lower layer. Our analysis shows that erosion or deposition rates at the interface between layers must in general satisfy three jump conditions. These conditions impose constraints on valid erosion formulas, and they help determine the correct forms of depth-integrated conservation equations. Two of the three jump conditions are closely analogous to Rankine-Hugoniot conditions that describe the behavior of shocks in compressible gasses, and the third jump condition describes shear traction discontinuities that necessarily exist across eroding boundaries. Grain-fluid mixtures commonly behave as compressible materials as they undergo entrainment, because changes in bulk density occur as the mixtures mobilize and merge with an overriding flow. If no bulk density change occurs, then only the shear-traction jump condition applies. Even for this special case, however, accurate formulation of depth-integrated momentum equations requires a clear distinction between boundary shear tractions that exist in the presence or absence of bed erosion.

  3. Computer aided process planning system based on workflow technology and integrated bill of material tree

    Institute of Scientific and Technical Information of China (English)

    LU Chun-guang; MENG Li-li

    2006-01-01

    It is extremely important for procedure of process design and management of process data for product life cycle in Computer Aided Process Planning (CAPP) system,but there are many shortcomings with traditional CAPP system in these respects.To solve these questions,application of workflow technology in CAPP system based on web-integrated Bill of Material (BOM) tree is discussed,and a concept of integrated BOM tree was brought forward.Taking integrated BOM as the thread,CAPP systematic technological process is analyzed.The function,system architecture,and implementation mechanism of CAPP system based on Browser/Server and Customer/Server model are expatiated.Based on it,the key technologies of workflow management device were analyzed.Eventually,the implementation mechanism of integrated BOM tree was analyzed from viewpoints of material information encoding,organization node design of integrated BOM tree,transformation from Engineering BOM (EBOM)to Process BOM (PBOM),and the programming implementation technology.

  4. Material derivatives of boundary integral operators in electromagnetism and application to inverse scattering problems

    Science.gov (United States)

    Ivanyshyn Yaman, Olha; Le Louër, Frédérique

    2016-09-01

    This paper deals with the material derivative analysis of the boundary integral operators arising from the scattering theory of time-harmonic electromagnetic waves and its application to inverse problems. We present new results using the Piola transform of the boundary parametrisation to transport the integral operators on a fixed reference boundary. The transported integral operators are infinitely differentiable with respect to the parametrisations and simplified expressions of the material derivatives are obtained. Using these results, we extend a nonlinear integral equations approach developed for solving acoustic inverse obstacle scattering problems to electromagnetism. The inverse problem is formulated as a pair of nonlinear and ill-posed integral equations for the unknown boundary representing the boundary condition and the measurements, for which the iteratively regularized Gauss-Newton method can be applied. The algorithm has the interesting feature that it avoids the numerous numerical solution of boundary value problems at each iteration step. Numerical experiments are presented in the special case of star-shaped obstacles.

  5. Hygrothermal Fracture Analysis of Orthotropic Functionally Graded Materials Using Jk-Integral-Based Methods

    Directory of Open Access Journals (Sweden)

    Serra Topal

    2013-01-01

    Full Text Available This paper puts forward two different Jk-integral-based methods, which can be used to perform mixed-mode fracture analysis of orthotropic functionally graded materials subjected to hygrothermal stresses. The first method requires the evaluation of both components of Jk-integral, whereas the second method employs the first component J1 and the asymptotic crack tip displacement fields. Plane orthotropic hygrothermoelasticity is the basic theory behind the Jk-integral formulation, which is carried out by assuming that all material properties are functions of the spatial coordinates. Developed procedures are implemented by means of the finite element method and integrated into a general purpose finite element analysis software. Temperature and specific moisture concentration fields needed in the fracture analyses are also computed through finite element analysis. Each of the developed methods is utilized in conjunction with the superposition technique to calculate the hygrothermal fracture parameters. An inclined crack located in a hygrothermally loaded orthotropic functionally graded layer is examined in parametric analyses. Comparisons of the results generated by the proposed methods do indicate that both methods lead to numerical results of high accuracy and that the developed form of the Jk-integral is domain independent. Further results are presented so as to illustrate the influences of crack inclination angle, crack length, and crack location upon the modes I and II stress intensity factors.

  6. Simulation of a high temperature thermal energy storage system employing several families of phase-change storage material

    Energy Technology Data Exchange (ETDEWEB)

    Adebiyi, G.A. [Mississippi State Univ., MS (United States)

    1989-03-01

    Previous work by the author entailed modeling of the Packed Bed Thermal Energy Storage System, utilizing Phase-Change Materials, and a performance evaluation of the system based on the Second Law of thermodynamics. A principal conclusion reached is that the use of a single family of phase-change storage material may not in fact produce a thermodynamically superior system relative to one utilizing sensible heat storage material. This prompted us to modify our model so that we could investigate whether or not a significantly improved performance may be achieved via the use of multiple families of phase-change materials instead. Other factors investigated in the present work include the effect on system performance due to the thermal mass of the containment vessel wall, varying temperature and mass flow rate of the flue gas entering the packed bed during the storage process, and thermal radiation which could be a significant factor at high temperature levels. The resulting model is intended to serve as an integral part of a real-time simulation of the application of a high temperature regenerator in a periodic brick plant. This paper describes the more comprehensive model of the high temperature thermal energy storage system and presents results indicating that improved system performance could be achieved via a judicious choice of multiple families of phase-change materials.

  7. Integrated ion sensor device applications based on printed hybrid material systems (Conference Presentation)

    Science.gov (United States)

    List-Kratochvil, Emil J. W.

    2016-09-01

    Comfortable, wearable sensors and computers will enhance every person's awareness of his or her health condition, environment, chemical pollutants, potential hazards, and information of interest. In agriculture and in the food industry there is a need for a constant control of the condition and needs of plants, animals, and farm products. Yet many of these applications depend upon the development of novel, cheap devices and sensors that are easy to implement and to integrate. Organic semiconductors as well as several inorganic materials and hybrid material systems have proven to combine a number of intriguing optical and electronic properties with simple processing methods. As it will be reviewed in this contribution, these materials are believed to find their application in printed electronic devices allowing for the development of smart disposable devices in food-, health-, and environmental monitoring, diagnostics and control, possibly integrated into arrays of sensor elements for multi-parameter detection. In this contribution we review past and recent achievements in the field. Followed by a brief introduction, we will focus on two topics being on the agenda recently: a) the use of electrolyte-gated organic field-effect transistor (EGOFET) and ion-selective membrane based sensors for in-situ sensing of ions and biological substances and b) the development of hybrid material based resistive switches and their integration into fully functional, printed hybrid crossbar sensor array structures.

  8. Cohesive fracture of elastically heterogeneous materials: An integrative modeling and experimental study

    Science.gov (United States)

    Wang, Neng; Xia, Shuman

    2017-01-01

    A combined modeling and experimental effort is made in this work to examine the cohesive fracture mechanisms of heterogeneous elastic solids. A two-phase laminated composite, which mimics the key microstructural features of many tough engineering and biological materials, is selected as a model material system. Theoretical and finite element analyses with cohesive zone modeling are performed to study the effective fracture resistance of the heterogeneous material associated with unstable crack propagation and arrest. A crack-tip-position controlled algorithm is implemented in the finite element analysis to overcome the inherent instability issues resulting from crack pinning and depinning at local heterogeneities. Systematic parametric studies are carried out to investigate the effects of various material and geometrical parameters, including the modulus mismatch ratio, phase volume fraction, cohesive zone size, and cohesive law shape. Concurrently, a novel stereolithography-based three-dimensional (3D) printing system is developed and used for fabricating heterogeneous test specimens with well-controlled structural and material properties. Fracture testing of the specimens is performed using the tapered double-cantilever beam (TDCB) test method. With optimal material and geometrical parameters, heterogeneous TDCB specimens are shown to exhibit enhanced effective fracture energy and effective fracture toughness than their homogeneous counterparts, which is in good agreement with the modeling predictions. The integrative computational and experimental study presented here provides a fundamental mechanistic understanding of the fracture mechanisms in brittle heterogeneous materials and sheds light on the rational design of tough materials through patterned heterogeneities.

  9. The changing role of the National Laboratories in materials research

    Energy Technology Data Exchange (ETDEWEB)

    Wadsworth, J.; Fluss, M.

    1995-06-02

    The role of the National Laboratories is summarized from the era of post World War II to the present time. The U.S. federal government policy for the National Laboratories and its influence on their materials science infrastructure is reviewed with respect to: determining overall research strategies, various initiatives to interact with industry (especially in recent years), building facilities that serve the nation, and developing leading edge research in the materials sciences. Despite reductions in support for research in the U.S. in recent years, and uncertainties regarding the specific policies for R&D in the U.S., there are strong roles for materials research at the National Laboratories. These roles will be centered on the abilities of the National Laboratories to field multidisciplinary teams, the use of unique cutting edge facilities, a focus on areas of strength within each of the labs, increased teaming and partnerships, and the selection of motivated research areas. It is hoped that such teaming opportunities will include new alliances with China, in a manner similar, perhaps, to those recently achieved between the U.S. and other countries.

  10. Integrated Climate Change Information for Resilient Adaptation Planning

    Science.gov (United States)

    Awareness is growing that some air, water, and ecosystem impacts from climate change are inevitable due to the long residence times of key greenhouse gases (GHGs), including carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), which are in...

  11. Analysis of writing and erasing behaviours in phase change materials

    Energy Technology Data Exchange (ETDEWEB)

    Hyot, B. E-mail: bhyot@cea.fr; Poupinet, L.; Gehanno, V.; Desre, P.J

    2002-09-01

    An understanding of the process involved in writing and erasing of phase-change optical recording media is vital to the development of new, and the improvement of existing, products. The present work investigates both experimental and theoretical laser-induced fast structural transformations of GeSbTe thin films. Optical and microstructural changes are correlated using both a static tester and transmission electron microscopy. In the second part of this paper we try to elucidate the physics underlying the amorphous-to-crystalline phase transformation under short-pulse laser excitation. Both thermal and thermodynamical behaviours must be taken into account to illustrate real processes.

  12. A Multi-Index Integrated Change detection method for updating the National Land Cover Database

    Science.gov (United States)

    Jin, Suming; Yang, Limin; Xian, George Z.; Danielson, Patrick; Homer, Collin G.

    2010-01-01

    Land cover change is typically captured by comparing two or more dates of imagery and associating spectral change with true thematic change. A new change detection method, Multi-Index Integrated Change (MIIC), has been developed to capture a full range of land cover disturbance patterns for updating the National Land Cover Database (NLCD). Specific indices typically specialize in identifying only certain types of disturbances; for example, the Normalized Burn Ratio (NBR) has been widely used for monitoring fire disturbance. Recognizing the potential complementary nature of multiple indices, we integrated four indices into one model to more accurately detect true change between two NLCD time periods. The four indices are NBR, Normalized Difference Vegetation Index (NDVI), Change Vector (CV), and a newly developed index called the Relative Change Vector (RCV). The model is designed to provide both change location and change direction (e.g. biomass increase or biomass decrease). The integrated change model has been tested on five image pairs from different regions exhibiting a variety of disturbance types. Compared with a simple change vector method, MIIC can better capture the desired change without introducing additional commission errors. The model is particularly accurate at detecting forest disturbances, such as forest harvest, forest fire, and forest regeneration. Agreement between the initial change map areas derived from MIIC and the retained final land cover type change areas will be showcased from the pilot test sites.

  13. Material and energy recovery in integrated waste management systems. An evaluation based on life cycle assessment.

    Science.gov (United States)

    Giugliano, Michele; Cernuschi, Stefano; Grosso, Mario; Rigamonti, Lucia

    2011-01-01

    This paper reports the environmental results, integrated with those arising from mass and energy balances, of a research project on the comparative analysis of strategies for material and energy recovery from waste, funded by the Italian Ministry of Education, University and Research. The project, involving the cooperation of five University research groups, was devoted to the optimisation of material and energy recovery activities within integrated municipal solid waste (MSW) management systems. Four scenarios of separate collection (overall value of 35%, 50% without the collection of food waste, 50% including the collection of food waste, 65%) were defined for the implementation of energetic, environmental and economic balances. Two sizes of integrated MSW management system (IWMS) were considered: a metropolitan area, with a gross MSW production of 750,000 t/year and an average province, with a gross MSW production of 150,000 t/year. The environmental analysis was conducted using Life Cycle Assessment methodology (LCA), for both material and energy recovery activities. In order to avoid allocation we have used the technique of the expansion of the system boundaries. This means taking into consideration the impact on the environment related to the waste management activities in comparison with the avoided impacts related to the saving of raw materials and primary energy. Under the hypotheses of the study, both for the large and for the small IWMS, the energetic and environmental benefits are higher than the energetic and environmental impacts for all the scenarios analysed in terms of all the indicators considered: the scenario with 50% separate collection in a drop-off scheme excluding food waste shows the most promising perspectives, mainly arising from the highest collection (and recycling) of all the packaging materials, which is the activity giving the biggest energetic and environmental benefits. Main conclusions of the study in the general field of the

  14. Driving behavioural change towards ecodesign integration: Nudging experiment in industry

    OpenAIRE

    Brones, Fabien; Gyldendal Melberg, Morten; Monteiro de Carvalho, Marly; Pigosso, Daniela Cristina Antelmi; McAloone, Tim C.

    2014-01-01

    This paper describes a research study conducted at Natura, a large Brazilian cosmetic company, in order to stimulate more systematic sustainable innovation practices by means of behavioural change. Within the “soft side” of ecodesign implementation, “nudging” is a novel approach brought from social sciences and policy making. An empirical experiment identified and tested employee motivations in combination with behavioural influences, in order to positively affect employees’ intention to prac...

  15. Materials Integration and Doping of Carbon Nanotube-based Logic Circuits

    Science.gov (United States)

    Geier, Michael

    Over the last 20 years, extensive research into the structure and properties of single- walled carbon nanotube (SWCNT) has elucidated many of the exceptional qualities possessed by SWCNTs, including record-setting tensile strength, excellent chemical stability, distinctive optoelectronic features, and outstanding electronic transport characteristics. In order to exploit these remarkable qualities, many application-specific hurdles must be overcome before the material can be implemented in commercial products. For electronic applications, recent advances in sorting SWCNTs by electronic type have enabled significant progress towards SWCNT-based integrated circuits. Despite these advances, demonstrations of SWCNT-based devices with suitable characteristics for large-scale integrated circuits have been limited. The processing methodologies, materials integration, and mechanistic understanding of electronic properties developed in this dissertation have enabled unprecedented scales of SWCNT-based transistor fabrication and integrated circuit demonstrations. Innovative materials selection and processing methods are at the core of this work and these advances have led to transistors with the necessary transport properties required for modern circuit integration. First, extensive collaborations with other research groups allowed for the exploration of SWCNT thin-film transistors (TFTs) using a wide variety of materials and processing methods such as new dielectric materials, hybrid semiconductor materials systems, and solution-based printing of SWCNT TFTs. These materials were integrated into circuit demonstrations such as NOR and NAND logic gates, voltage-controlled ring oscillators, and D-flip-flops using both rigid and flexible substrates. This dissertation explores strategies for implementing complementary SWCNT-based circuits, which were developed by using local metal gate structures that achieve enhancement-mode p-type and n-type SWCNT TFTs with widely separated and

  16. 2006/07 Field Testing of Cellulose Fiber Insulation Enhanced with Phase Change Material

    Energy Technology Data Exchange (ETDEWEB)

    Kosny, Jan [ORNL; Yarbrough, David W [ORNL; Miller, William A [ORNL; Petrie, Thomas [ORNL; Childs, Phillip W [ORNL; Syed, Azam M [ORNL

    2008-12-01

    Most recent improvements in building envelope technologies suggest that in the near future, residences will be routinely constructed to operate with very low heating and cooling loads. In that light, the application of novel building materials containing active thermal components (e.g., phase change materials [PCMs,] sub-venting, radiant barriers, and integrated hydronic systems) is like a final step in achieving relatively significant heating and cooling energy savings from technological improvements in the building envelope. It is expected that optimized building envelope designs using PCMs for energy storage can effectively bring notable savings in energy consumption and reductions in peak hour power loads. During 2006/07, a research team at Oak Ridge National Laboratory (ORNL) performed a series of laboratory and field tests of several wall and roof assemblies using PCM-enhanced cellulose insulation. This report summarizes the test results from the perspective of energy performance. The ORNL team is working on both inorganic and organic PCMs; this report discusses only paraffinic PCMs. A limited economical analysis also is presented. PCMs have been tested as a thermal mass component in buildings for at least 40 years. Most of the research studies found that PCMs enhanced building energy performance. In the case of the application of organic PCMs, problems such as high initial cost and PCM leaking (surface sweating) have hampered widespread adoption. Paraffinic hydrocarbon PCMs generally performed well, with the exception that they increased the flammability of the building envelope.

  17. Integration of Networks of Sensors and Electronics for Structural Health Monitoring of Composite Materials

    Directory of Open Access Journals (Sweden)

    Fabrizia Ghezzo

    2010-01-01

    Full Text Available The low-cost, widespread availability and robust nature of current electronic devices suggest the feasibility of creating a composite structure with integrated networked sensors to monitor in real time the life of civil and aerospace structures while in service conditions. For structures that need to survive to high number of life cycles under varying load-environmental conditions, it is of crucial importance that the strength, stiffness, endurance, and general load-bearing capabilities of the composite not to be severely degraded by the integrated networked components. Therefore, design tools must be developed to achieve optimized, safe, and reliable structures. High values of stress concentrations due to the presence of a rigid device within a highly anisotropic material can trigger the initiation of microcracks in the resin matrix. To quantify these effects, the acoustic emission technique is used to characterize the initiation of microfailures within laminated composites with integrated electronics.

  18. Thermophysical properties and behavioral characteristics of phase-change materials

    Energy Technology Data Exchange (ETDEWEB)

    Cantor, S

    1977-01-01

    The primary and near-term objective of the project is to compile a handbook of compounds and mixtures that melt in the range of 90 to 250/sup 0/C and which are suitable for isothermal heat storage. Organic compounds have been screened according to bulk price, thermal stability, and safety. Compounds were selected for further consideration if they cost less than $1.10/kg and if encyclopedia articles or handbooks indicated that they were reasonably stable chemically and were not toxic or otherwise hazardous. Of seven compounds thus selected, four (urea, phthalimide, adipic acid, phthalic anhydride) have been examined by DSC and other methods. The differential scanning calorimeter was used with two fairly well-characterized PCM's to test its applicability for rapidly evaluating thermal decomposition and supercooling. With Na/sub 2/SO/sub 4/ . 10H/sub 2/O, DSC data indicated (a) decrease in heat of transition with thermal cycling, and (b) considerable supercooling; with 3 to 6 percent borax added, supercooling was greatly lessened but not entirely eliminated. Measurements with paraffin wax showed that this material does not supercool nor does it degrade in thermal performance with cycling. The DSC results with these two materials confirmed (and extended) thermal performance characteristics obtained by other means. However, studies of supercooling in urea and in phthalimide suggested that DSC techniques may magnify the extent of supercooling at elevated temperatures.

  19. Integrated Cognitive-neuroscience Architectures for Understanding Sensemaking (ICArUS): Overview of Test and Evaluation Materials

    Science.gov (United States)

    2014-11-01

    Integrated Cognitive- neuroscience Architectures for Understanding Sensemaking (ICArUS): Overview of Test and Evaluation Materials Kevin...00-2014 to 00-00-2014 4. TITLE AND SUBTITLE Integrated Cognitive- neuroscience Architectures for Understanding Sensemaking (ICArUS): A...14. ABSTRACT The IARPA (Intelligence Advanced Research Projects Activity) program ICArUS (Integrated Cognitive- neuroscience Architectures for

  20. Integrating comparative functional response experiments into global change research.

    Science.gov (United States)

    O'Gorman, Eoin J

    2014-05-01

    There is a growing appreciation for the importance of non-consumptive effects in predator-prey interaction research, which can often outweigh the importance of direct feeding. Barrios-O'Neill et al. (2014) report a novel method to characterize such effects by comparing the functional response of native and introduced intermediate consumers in the presence and absence of a higher predator. The invader exhibited stronger direct feeding and was also more resistant to intimidation by the higher predator. This experimental framework may be incorporated into mainstream global change research, for example, to quantify the importance of non-consumptive effects for the success or failure of biological invasions.

  1. Changing Personal Epistemologies in Early Childhood Pre-Service Teachers Using an Integrated Teaching Program

    Science.gov (United States)

    Brownlee, Jo; Petriwskyj, Anne; Thorpe, Karen; Stacey, Phillip; Gibson, Megan

    2011-01-01

    This study investigated changes in pre-service teachers' personal epistemologies as they engaged in an integrated teaching program. Personal epistemology refers to individual beliefs about the nature of knowing and knowledge and has been shown to influence teaching practice. An integrated approach to teaching, based on both an "implicit" and…

  2. Changing Personal Epistemologies in Early Childhood Pre-Service Teachers Using an Integrated Teaching Program

    Science.gov (United States)

    Brownlee, Jo; Petriwskyj, Anne; Thorpe, Karen; Stacey, Phillip; Gibson, Megan

    2011-01-01

    This study investigated changes in pre-service teachers' personal epistemologies as they engaged in an integrated teaching program. Personal epistemology refers to individual beliefs about the nature of knowing and knowledge and has been shown to influence teaching practice. An integrated approach to teaching, based on both an "implicit"…

  3. Policy Change Implication Toward Integrated Wonorejo Zone as A Strategic Economic Development Zone

    Directory of Open Access Journals (Sweden)

    Akbar Pandu Dwinugraha

    2014-04-01

    Full Text Available Integrated Wonorejo Zone is one of the development zone in Lumajang Regency with significant goals to improve potensial condition in three aspect namely tourism, agriculture and SMEs. Based on RTRW in 2008-2028, which was established in 2008, the development strategy of this zone is change. Integrated Wonorejo Zone was mentioned as a Strategic Economic Development Zone. This research describe and analyse about how the implication of policy change toward Integrated Wonorejo Zone. This research using method of descriptive research with qualitative approach as well as analysis of data by John Seidel about QDA (qualitative data analysis. The result of this research explain that the policy change implication, from description, implementation and implication point of view did not give significant expectation. Key Words: Policy Change, Integrated Wonorejo Zone, Strategic Economic Development Zone.

  4. Fracture and fatigue analysis of functionally graded and homogeneous materials using singular integral equation approach

    Science.gov (United States)

    Zhao, Huaqing

    There are two major objectives of this thesis work. One is to study theoretically the fracture and fatigue behavior of both homogeneous and functionally graded materials, with or without crack bridging. The other is to further develop the singular integral equation approach in solving mixed boundary value problems. The newly developed functionally graded materials (FGMs) have attracted considerable research interests as candidate materials for structural applications ranging from aerospace to automobile to manufacturing. From the mechanics viewpoint, the unique feature of FGMs is that their resistance to deformation, fracture and damage varies spatially. In order to guide the microstructure selection and the design and performance assessment of components made of functionally graded materials, in this thesis work, a series of theoretical studies has been carried out on the mode I stress intensity factors and crack opening displacements for FGMs with different combinations of geometry and material under various loading conditions, including: (1) a functionally graded layer under uniform strain, far field pure bending and far field axial loading, (2) a functionally graded coating on an infinite substrate under uniform strain, and (3) a functionally graded coating on a finite substrate under uniform strain, far field pure bending and far field axial loading. In solving crack problems in homogeneous and non-homogeneous materials, a very powerful singular integral equation (SEE) method has been developed since 1960s by Erdogan and associates to solve mixed boundary value problems. However, some of the kernel functions developed earlier are incomplete and possibly erroneous. In this thesis work, mode I fracture problems in a homogeneous strip are reformulated and accurate singular Cauchy type kernels are derived. Very good convergence rates and consistency with standard data are achieved. Other kernel functions are subsequently developed for mode I fracture in

  5. The role of organizational structure in readiness for change: A conceptual integration.

    Science.gov (United States)

    Benzer, Justin K; Charns, Martin P; Hamdan, Sami; Afable, Melissa

    2017-02-01

    The purpose of this review is to extend extant conceptualizations of readiness for change as an individual-level phenomenon. This review-of-reviews focuses on existing conceptual frameworks from the dissemination, implementation, quality improvement, and organizational transformation literatures in order to integrate theoretical rationales for how organization structure, a key dimension of the organizational context, may impact readiness for change. We propose that the organization structure dimensions of differentiation and integration impact readiness for change at the individual level of analysis by influencing four key concepts of relevance, legitimacy, perceived need for change, and resource allocation. We identify future research directions that focus on these four key concepts.

  6. Thermal performance of a pcm [phase change material] storage unit

    Energy Technology Data Exchange (ETDEWEB)

    Ismail, K.A.R.; Goncalves, M.M. [Depto de Engenharia Termica e de Fluidos-FEM-UNICAMP (Brazil)

    1999-10-01

    This paper presents a two-dimensional model for the phase change, conduction based heat transfer problem around a tube immersed in the pcm. The energy equation is written in the enthalpy form, and the heat and flow problems are coupled by an energy balance on the fluid element flowing inside the tube. The numerical solution is based upon the average control volume technique and the ADI finite difference representation. The results obtained show the effects of the variation of the ratio of the radius of the inner to the outer tube, Biot number, Stefan number and the working fluid inlet temperature on the solidified mass fraction, NTU and effectiveness. (author)

  7. Integrated firn elevation change model for glaciers and ice caps

    Science.gov (United States)

    Saß, Björn; Sauter, Tobias; Braun, Matthias

    2016-04-01

    We present the development of a firn compaction model in order to improve the volume to mass conversion of geodetic glacier mass balance measurements. The model is applied on the Arctic ice cap Vestfonna. Vestfonna is located on the island Nordaustlandet in the north east of Svalbard. Vestfonna covers about 2400 km² and has a dome like shape with well-defined outlet glaciers. Elevation and volume changes measured by e.g. satellite techniques are becoming more and more popular. They are carried out over observation periods of variable length and often covering different meteorological and snow hydrological regimes. The elevation change measurements compose of various components including dynamic adjustments, firn compaction and mass loss by downwasting. Currently, geodetic glacier mass balances are frequently converted from elevation change measurements using a constant conversion factor of 850 kg m-³ or the density of ice (917 kg m-³) for entire glacier basins. However, the natural conditions are rarely that static. Other studies used constant densities for the ablation (900 kg m-³) and accumulation (600 kg m-³) areas, whereby density variations with varying meteorological and climate conditions are not considered. Hence, each approach bears additional uncertainties from the volume to mass conversion that are strongly affected by the type and timing of the repeat measurements. We link and adapt existing models of surface energy balance, accumulation and snow and firn processes in order to improve the volume to mass conversion by considering the firn compaction component. Energy exchange at the surface is computed by a surface energy balance approach and driven by meteorological variables like incoming short-wave radiation, air temperature, relative humidity, air pressure, wind speed, all-phase precipitation, and cloud cover fraction. Snow and firn processes are addressed by a coupled subsurface model, implemented with a non-equidistant layer discretisation. On

  8. Integrated design and synthesis of smart material systems: an overview of the ARPA SPICES program

    Science.gov (United States)

    Jacobs, Jack H.

    1995-05-01

    The Synthesis and Processing of Intelligent Cost Effective Structures (SPICES) program is comprised of a consortium of industrial, academic and government labs to develop cost effective material processing and synthesis technologies to enable new products using active vibration suppression and control devices to be brought to market. Each team member possesses a specialty in the area of smart structures which has been focused towards the development of several actively controlled smart material systems. Since smart structures involve the integration of multiple engineering disciplines, it is the objective of the consortium to establish cost effective design processes between this multiorganizational team for future incorporation of this new technology into each members respective product lines. To accomplish this task, the disciplines of materials, manufacturing, analytical modeling, actuation, sensing, signal processing, and control had to be synthesized into a unified approach between all ten consortium members. The process developed for intelligent structural systems can truly be classified as multiorganization/multidiciplined Integrated Product Development. This process is described in detail as it applies to the SPICES development articles and smart material fabrication in general.

  9. Methods of saving energy and materials in the manufacture of integrated aircraft structure components

    Energy Technology Data Exchange (ETDEWEB)

    Sturm, J.C.; Welschof, K.; Janssen, W.; Mahlke, M.; Sprangers, W.; Binding, J.

    1987-11-01

    In the framework of a special research unit, methods for saving energy and raw materials are investigated for selected production processes. Integral construction components of the aircraft industry which today are mostly produced by metal-cutting processes, are the basis of the joint research work of six of the total of nineteen participating projects. Research is carried out on the possibilities for reducing the expenditure of material and energy by the application of alternative production processes in the field of primary shaping, deforming and joining as well as by structural optimization. By means of a computer-aided evaluation of the possible production methods, the alternatives can be compared with regard to their energy and raw material requirements.

  10. Non-von Neumann computing using plasmon particles interacting with phase change materials (Conference Presentation)

    Science.gov (United States)

    Saiki, Toshiharu

    2016-09-01

    Control of localized surface plasmon resonance (LSPR) excited on metal nanostructures has drawn attention for applications in dynamic switching of plasmonic devices. As a reversible active media for LSPR control, chalcogenide phase-change materials (PCMs) such as GeSbTe (GST) are promising for high-contrast robust plasmonic switching. Owing to the plasticity and the threshold behavior during both amorphization and crystallization of PCMs, PCM-based LSPR switching elements possess a dual functionality of memory and processing. Integration of LSPR switching elements so that they interact with each other will allow us to build non-von-Neumann computing devices. As a specific demonstration, we discuss the implementation of a cellular automata (CA) algorithm into interacting LSPR switching elements. In the model we propose, PCM cells, which can be in one of two states (amorphous and crystalline), interact with each other by being linked by a AuNR, whose LSPR peak wavelength is determined by the phase of PCM cells on the both sides. The CA program proceeds by irradiating with a light pulse train. The local rule set is defined by the temperature rise in the PCM cells induced by the LSPR of the AuNR, which is subject to the intensity and wavelength of the irradiating pulse. We also investigate the possibility of solving a problem analogous to the spin-glass problem by using a coupled dipole system, in which the individual coupling strengths can be modified to optimize the system so that the exact solution can be easily reached. For this algorithm, we propose an implementation based on an idea that coupled plasmon particles can create long-range spatial correlations, and the interaction of this with a phase-change material allows the coupling strength to be modified.

  11. Modelling of phase change materials in the Toronto SUI net zero energy house using TRNSYS

    Energy Technology Data Exchange (ETDEWEB)

    Siddiqui, O.; Fung, A.; Zhang, D. [Ryerson Polytechnic Univ., Toronto, ON (Canada). Dept. of Mechanical and Industrial Engineering

    2008-08-15

    In the context of building applications, phase change materials (PCM), can be defined as any heat storage material that can absorb a large amount of thermal energy while undergoing a change in phase, such as from a solid to a liquid phase. The incorporation of PCM into the building envelope can enhance occupant comfort through the reduction of indoor temperature fluctuations. It has also been shown to cause a decrease in the overall energy consumption associated with the heating and cooling of buildings. This paper extended the analysis of the impact of using PCM, which has traditionally focused on homes of ordinary construction, to incorporate low to zero energy homes using a model of the Toronto net zero energy house developed in TRNSYS. The paper provided a description of the TRNSYS model/methodology, with reference to the wall layer used in the net zero energy house, and model of the layout of the net zero energy house in TRYNSYS. The TRYNSYS/type 204 PCM component was also presented along with the simulation results in terms of the temperature profile of the third floor of the net zero energy house on a typical winter day with varying PCM concentrations; the temperature profile of the third floor of the net zero energy house on a typical summer day with varying PCM concentrations; yearly heating/cooling load requirements of the net zero energy house for a variety of thermal mass used; temperature profile of the third floor of the net zero energy house on a typical summer day when PCM and concrete slab was used; yearly temperature profile of the third floor of the net zero energy house, illustrating the impact of using PCM; and the yearly heating/cooling load of the net zero energy house as the concentration of PCM was varied. It was concluded that the use of building integrated PCM can reduce temperature fluctuations considerably in the summer but only slightly in the winter. 16 refs., 1 tab., 8 figs.

  12. Integrated hydrological SVAT model for climate change studies in Denmark

    Science.gov (United States)

    Mollerup, M.; Refsgaard, J.; Sonnenborg, T. O.

    2010-12-01

    In a major Danish funded research project (www.hyacints.dk) a coupling is being established between the HIRHAM regional climate model code from Danish Meteorological Institute and the MIKE SHE distributed hydrological model code from DHI. The linkage between those two codes is a soil vegetation atmosphere transfer scheme, which is a module of MIKE SHE. The coupled model will be established for the entire country of Denmark (43,000 km2 land area) where a MIKE SHE based hydrological model already exists (Henriksen et al., 2003, 2008). The present paper presents the MIKE SHE SVAT module and the methodology used for parameterising and calibrating the MIKE SHE SVAT module for use throughout the country. As SVAT models previously typically have been tested for research field sites with comprehensive data on energy fluxes, soil and vegetation data, the major challenge lies in parameterisation of the model when only ordinary data exist. For this purpose annual variations of vegetation characteristics (Leaf Area Index (LAI), Crop height, Root depth and the surface albedo) for different combinations of soil profiles and vegetation types have been simulated by use of the soil plant atmosphere model Daisy (Hansen et al., 1990; Abrahamsen and Hansen, 2000) has been applied. The MIKE SHE SVAT using Daisy generated surface/soil properties model has been calibrated against existing data on groundwater heads and river discharges. Simulation results in form of evapotranspiration and percolation are compared to the existing MIKE SHE model and to observations. To analyse the use of the SVAT model in climate change impact assessments data from the ENSEMBLES project (http://ensembles-eu.metoffice.com/) have been analysed to assess the impacts on reference evapotranspiration (calculated by the Makkink and the Penmann-Monteith equations) as well as on the individual elements in the Penmann-Monteith equation (radiation, wind speed, humidity and temperature). The differences on the

  13. Effect of microencapsulated phase change material in sandwich panels

    Energy Technology Data Exchange (ETDEWEB)

    Castellon, Cecilia; Medrano, Marc; Roca, Joan; Cabeza, Luisa F. [GREA Innovacio Concurrent, Edifici CREA, Universitat de Lleida, Pere de Cabrera s/n, 25001 Lleida (Spain); Navarro, Maria E.; Fernandez, Ana I. [Departamento de Ciencias de los Materiales e Ingenieria Metalurgica, Universitat de Barcelona, Marti i Franques 1, 08028 Barcelona (Spain); Lazaro, Ana; Zalba, Belen [Instituto de Investigacion en Ingenieria de Aragon, I3A, Grupo de Ingenieria Termica y Sistemas Energeticos (GITSE), Dpto. Ingenieria Mecanica, Area de Maquinas y Motores Termicos, Universidad de Zaragoza, Campus Politecnico Rio Ebro, Edificio ' ' Agustin de Betancourt,' ' Maria de Luna s/n, 50018 Zaragoza (Spain)

    2010-10-15

    Sandwich panels are a good option as building materials, as they offer excellent characteristics in a modular system. The goal of this study was to demonstrate the feasibility of using the microencapsulated PCM (Micronal BASF) in sandwich panels to increase their thermal inertia and to reduce the energy demand of the final buildings. In this paper, to manufacture the sandwich panel with microencapsulated PCM three different methods were tested. In case 1, the PCM was added mixing the microencapsulated PCM with one of the components of the polyurethane. In the other two cases, the PCM was added either a step before (case 2) or a step after (case 3) to the addition of the polyurethane to the metal sheets. The results show that in case 1 the effect of PCM was overlapped by a possible increase in thermal conductivity, but an increase of thermal inertia was found in case 3. In case 2, different results were obtained due to the poor distribution of the PCM. Some samples showed the effect of the PCM (higher thermal inertia), and other samples results were similar to the conventional sandwich panel. In both cases (2 and 3), it is required to industrialize the process to improve the results. (author)

  14. Change of Scale Formulas for Wiener Integrals Related to Fourier-Feynman Transform and Convolution

    Directory of Open Access Journals (Sweden)

    Bong Jin Kim

    2014-01-01

    Full Text Available Cameron and Storvick discovered change of scale formulas for Wiener integrals of functionals in Banach algebra S on classical Wiener space. Yoo and Skoug extended these results for functionals in the Fresnel class F(B and in a generalized Fresnel class FA1,A2 on abstract Wiener space. We express Fourier-Feynman transform and convolution product of functionals in S as limits of Wiener integrals. Moreover we obtain change of scale formulas for Wiener integrals related to Fourier-Feynman transform and convolution product of these functionals.

  15. Dielectric Characteristics of Microstructural Changes and Property Evolution in Engineered Materials

    Science.gov (United States)

    Clifford, Jallisa Janet

    Heterogeneous materials are increasingly used in a wide range of applications such as aerospace, civil infrastructure, fuel cells and many others. The ability to take properties from two or more materials to create a material with properties engineered to needs is always very attractive. Hence heterogeneous materials are evolving into more complex formulations in multiple disciplines. Design of microstructure at multiple scales control the global functional properties of these materials and their structures. However, local microstructural changes do not directly cause a proportional change to the global properties (such as strength and stiffness). Instead, local changes follow an evolution process including significant interactions. Therefore, in order to understand property evolution of engineered materials, microstructural changes need to be effectively captured. Characterizing these changes and representing them by material variables will enable us to further improve our material level understanding. In this work, we will demonstrate how microstructural features of heterogeneous materials can be described quantitatively using broadband dielectric spectroscopy (BbDS). The frequency dependent dielectric properties can capture the change in material microstructure and represent these changes in terms of material variables, such as complex permittivity. These changes in terms of material properties can then be linked to a number of different conditions, such as increasing damage due to impact or fatigue. Two different broadband dielectric spectroscopy scanning modes are presented: bulk measurements and continuous scanning to measure dielectric property change as a function of position across the specimen. In this study, we will focus on ceramic materials and fiber reinforced polymer matrix composites as test bed material systems. In the first part of the thesis, we will present how different micro-structural design of porous ceramic materials can be captured

  16. Identity: empirical contribution. Changes in the identity integration of adolescents in treatment for personality disorders.

    Science.gov (United States)

    Feenstra, Dine J; Hutsebaut, Joost; Verheul, Roel; van Limbeek, Jacques

    2014-02-01

    A renewed interest in identity as one of the core markers of personality disorders has been introduced by the DSM-5 Level of Personality Functioning Scale. However, little is known about the utility of the construct of identity in children and adolescents. This study aimed to broaden the knowledge of identity integration as a core component of personality functioning in adolescents. The authors investigated levels of identity integration, as measured by the Severity Indices of Personality Problems (SIPP-118; Verheul et al., 2008), in adolescents in both normal (n = 406) and clinical populations (n = 285). Furthermore, changes in levels of identity integration during treatment were investigated in a clinical subsample (n = 76). Levels of identity integration were not associated with age. They were, however, associated with the absence or presence of personality pathology. Most adolescents receiving inpatient psychotherapy gradually changed toward more healthy levels of identity integration; a significant number, however, remained at maladaptive levels of identity functioning after intensive psychotherapy.

  17. Assessing climate change impact by integrated hydrological modelling

    Science.gov (United States)

    Lajer Hojberg, Anker; Jørgen Henriksen, Hans; Olsen, Martin; der Keur Peter, van; Seaby, Lauren Paige; Troldborg, Lars; Sonnenborg, Torben; Refsgaard, Jens Christian

    2013-04-01

    Future climate may have a profound effect on the freshwater cycle, which must be taken into consideration by water management for future planning. Developments in the future climate are nevertheless uncertain, thus adding to the challenge of managing an uncertain system. To support the water managers at various levels in Denmark, the national water resources model (DK-model) (Højberg et al., 2012; Stisen et al., 2012) was used to propagate future climate to hydrological response under considerations of the main sources of uncertainty. The DK-model is a physically based and fully distributed model constructed on the basis of the MIKE SHE/MIKE11 model system describing groundwater and surface water systems and the interaction between the domains. The model has been constructed for the entire 43.000 km2 land area of Denmark only excluding minor islands. Future climate from General Circulation Models (GCM) was downscaled by Regional Climate Models (RCM) by a distribution-based scaling method (Seaby et al., 2012). The same dataset was used to train all combinations of GCM-RCMs and they were found to represent the mean and variance at the seasonal basis equally well. Changes in hydrological response were computed by comparing the short term development from the period 1990 - 2010 to 2021 - 2050, which is the time span relevant for water management. To account for uncertainty in future climate predictions, hydrological response from the DK-model using nine combinations of GCMs and RCMs was analysed for two catchments representing the various hydrogeological conditions in Denmark. Three GCM-RCM combinations displaying high, mean and low future impacts were selected as representative climate models for which climate impact studies were carried out for the entire country. Parameter uncertainty was addressed by sensitivity analysis and was generally found to be of less importance compared to the uncertainty spanned by the GCM-RCM combinations. Analysis of the simulations

  18. Integration of Landsat TM and SPOT HRG Images for Vegetation Change Detection in the Brazilian Amazon.

    Science.gov (United States)

    Lu, Dengsheng; Batistella, Mateus; Moran, Emilio

    2008-01-01

    Traditional change detection approaches have been proven to be difficult in detecting vegetation changes in the moist tropical regions with multitemporal images. This paper explores the integration of Landsat Thematic Mapper (TM) and SPOT High Resolution Geometric (HRG) instrument data for vegetation change detection in the Brazilian Amazon. A principal component analysis was used to integrate TM and HRG panchromatic data. Vegetation change/non-change was detected with the image differencing approach based on the TM and HRG fused image and the corresponding TM image. A rule-based approach was used to classify the TM and HRG multispectral images into thematic maps with three coarse land-cover classes: forest, non-forest vegetation, and non-vegetation lands. A hybrid approach combining image differencing and post-classification comparison was used to detect vegetation change trajectories. This research indicates promising vegetation change techniques, especially for vegetation gain and loss, even if very limited reference data are available.

  19. Field experiments on the use of phase changing materials, insulation materials and passive solar radiation in the built environment

    NARCIS (Netherlands)

    Entrop, A.G.; Brouwers, H.J.H.; Reinders, A.H.M.E.

    2008-01-01

    This paper describes the development of an experimental research facility to assess the effectiveness of Phase Change Materials (PCM), that can be used for passive solar heating. Four test boxes are constructed representing the conventional and future Dutch building practices regarding insulation an

  20. [Modification changes of the genetic material in Saccharomyces yeasts].

    Science.gov (United States)

    Repnevskaia, M V; Kashkin, P K; Inge-Vechtomov, S G

    1989-03-01

    The problem of mating-type switches in heterothallic yeast cells was investigated. In selective system for cytoduction in alpha x alpha crosses alpha-cytoductants were predominantly obtained. Thus matings in alpha x alpha crosses can proceed through non-heritable changes (modifications) of the mating type alpha----a. The frequency of alpha-cytoductants after UV-irradiation of the recipient cells exceeded the control value 50-90 times. The extra copy of MAT alpha dramatically decreased the frequency of cytoductants in alpha x alpha crosses, either spontaneously or after UV-irradiation. The rad18 recipient defective in postreplication repair had 70-times increased level of mating-type modifications, as compared with isogenic Rad+ strain. An explanation consistent with these data is that mating-type modifications are due to phenotypic expression of primary lesions of MAT alpha locus. Such lesions might be expressed as transient a-mating type. After the mating event, these lesions can be repaired or turned to true mutations within the MAT locus. In fact, approximately half of non-mating cytoductants from alpha x alpha crosses had the phenotype of mat alpha 2 mutants.

  1. The integration of climate change, spatial dynamics, and habitat fragmentation: A conceptual overview.

    Science.gov (United States)

    Holyoak, Marcel; Heath, Sacha K

    2016-01-01

    A growing number of studies have looked at how climate change alters the effects of habitat fragmentation and degradation on both single and multiple species; some raise concern that biodiversity loss and its effects will be exacerbated. The published literature on spatial dynamics (such as dispersal and metapopulation dynamics), habitat fragmentation and climate change requires synthesis and a conceptual framework to simplify thinking. We propose a framework that integrates how climate change affects spatial population dynamics and the effects of habitat fragmentation in terms of: (i) habitat quality, quantity and distribution; (ii) habitat connectivity; and (iii) the dynamics of habitat itself. We use the framework to categorize existing autecological studies and investigate how each is affected by anthropogenic climate change. It is clear that a changing climate produces changes in the geographic distribution of climatic conditions, and the amount and quality of habitat. The most thorough published studies show how such changes impact metapopulation persistence, source-sink dynamics, changes in species' geographic range and community composition. Climate-related changes in movement behavior and quantity, quality and distribution of habitat have also produced empirical changes in habitat connectivity for some species. An underexplored area is how habitat dynamics that are driven by climatic processes will affect species that live in dynamic habitats. We end our discussion by suggesting ways to improve current attempts to integrate climate change, spatial population dynamics and habitat fragmentation effects, and suggest distinct areas of study that might provide opportunities for more fully integrative work.

  2. Understanding the effect of an in situ generated and integrated spinel phase on a layered Li-rich cathode material using a non-stoichiometric strategy.

    Science.gov (United States)

    Zhang, Jicheng; Gao, Rui; Sun, Limei; Li, Zhengyao; Zhang, Heng; Hu, Zhongbo; Liu, Xiangfeng

    2016-09-14

    Recently, spinel-layered integrated Li-rich cathode materials have attracted great interest due to the large enhancement of their electrochemical performances. However, the modification mechanism and the effect of the integrated spinel phase on Li-rich layered cathode materials are still not very clear. Herein, we have successfully synthesized the spinel-layered integrated Li-rich cathode material using a facile non-stoichiometric strategy (NS-LNCMO). The rate capability (84 mA h g(-1)vs. 28 mA h g(-1), 10 C), cycling stability (92.4% vs. 80.5%, 0.2 C), low temperature electrochemical capability (96.5 mA h g(-1)vs. 59 mA h g(-1), -20 °C), initial coulomb efficiency (92% vs. 79%) and voltage fading (2.77 V vs. 3.02 V, 200 cycles@1 C) of spinel-layered integrated Li-rich cathode materials have been significantly improved compared with a pure Li-rich phase cathode. Some new insights into the effect of the integrated spinel phase on a layered Li-rich cathode have been proposed through a comparison of the structure evolution of the integrated and Li-rich only materials before and after cycling. The Li-ion diffusion coefficient of NS-LNCMO has been enlarged by about 3 times and almost does not change even after 100 cycles indicating an enhanced structure stability. The integration of the spinel phase not only enhances the structure stability of the layered Li-rich phase during charging-discharging but also expands the interslab spacing of the Li-ion diffusion layer, and elongates TM-O covalent bond lengths, which lowers the activation barrier of Li(+)-transportation, and alleviates the structure strain during the cycling procedure.

  3. Program on ecosystem change and society: An international research strategy for integrated social-ecological systems

    NARCIS (Netherlands)

    Carpenter, S.R.; Folke, C.; Norström, A.V.; Olsson, O.; Schultz, L.; Agarwal, B.; Balvanera, P.; Campbell, B.; Castilla, J.C.; Cramer, W.; DeFries, R.; Eyzaguirre, P.; Hughes, T.P.; Polasky, S.; Sanusi, Z.A.; Scholes, R.J.; Spierenburg, M.J.

    2012-01-01

    The Program on Ecosystem Change and Society (PECS), a new initiative within the ICSU global change programs, aims to integrate research on the stewardship of social-ecological systems, the services they generate, and the relationships among natural capital, human wellbeing, livelihoods, inequality a

  4. Removing the Blinders: Toward an Integrative Model of Organizational Change in Sport and Physical Activity.

    Science.gov (United States)

    Cunningham, George B.

    2002-01-01

    Discusses the nature of the change process in physical education and sports, presenting a model to incorporate in studies of radical organizational change. The integration of four theories (institutionalism, population ecology, strategic choice, and resource dependence) provides the basis for the model. The paper offers a hypothetical example and…

  5. Influence of the material removal mechanisms on hole integrity in ultrasonic machining of structural ceramics.

    Science.gov (United States)

    Nath, Chandra; Lim, G C; Zheng, H Y

    2012-07-01

    Micro-chipping via micro-cracks, due to rapid mechanical indentations by abrasive grits, is the fundamental mechanism of material removal during ultrasonic machining (USM) of hard-brittle materials like ceramics and glass. This study aims mainly to investigate the adverse effects of this inherent removal phenomena on the hole integrity such as entrance chipping, wall roughness and subsurface damage. It also presents the material removal mechanism happens in the gap between the tool periphery and the hole wall (called 'lateral gap'). To do so, experiments were conducted for drilling holes on three advanced structural ceramics, namely, silicon carbide, zirconia, and alumina. Earlier published basic studies on the initiation of different crack modes and their growth characteristics are employed to explain the experimental findings in this USM study. It is realized that the radial and the lateral cracks formed due to adjacent abrasives, which are under the tool face, extends towards radial direction of the hole resulting in entrance chipping. Additionally, the angle penetration and the rolling actions of the abrasives, which are at the periphery of the tool, contribute to the entrance chipping. Later on, in the 'lateral gap', the sliding (or abrasion) and the rolling mechanisms by the larger abrasives take part to material removal. However, they unfavorably produce micro-cracks in the radial direction resulting in surface and subsurface damages, which are ultimately responsible for higher wall-surface roughness. Since the size of micro-cracks in brittle materials is grit size dependent according to the earlier studied physics, it is realized that such nature of the hole integrity during USM can only be minimized by employing smaller grit size, but cannot fully be eliminated.

  6. The role of material engineering within the concept of an integrated water resources management

    Science.gov (United States)

    Breiner, Raphael; Müller, Harald S.

    2016-09-01

    By means of a case study, the successful implementation of a rheologically optimised cement-based mortar for the construction as well as for the rehabilitation of rain water cisterns is presented in this paper. The material was developed within the scope of a German-Indonesian joint project ["Integrated Water Resources Management" (IWRM)], funded by the German Federal Ministry of Education and Research. Comprehensive rheological investigations are presented which provide the database for the optimization of the mortar with regard to its intended range of application. For the selection of the source materials, special emphasis was placed on the ready availability at low cost. The rheological properties of the fresh mortar allow an easy workability by hand while the hardened mortar shows a durable and tight appearance at the same time. The developed material can be used as a coating for walls, floors and ceilings of cisterns, for the local rehabilitation of damaged areas only or even as a construction material for complete new cisterns. The future multiplication of the IWRM project results within the region was assured by a local capacity development when the presented material concept was applied in practise in Indonesia for the construction of sustainable rain water cisterns in Gunung Kidul.

  7. Assessment of Disaster Risk Reduction and Climate Change Adaptation policy integration in Zambia

    Science.gov (United States)

    Pilli-Sihvola, K.; Väätäinen-Chimpuku, S.

    2015-12-01

    Integration of Disaster Risk Management (DRM) and Climate Change Adaptation (CCA) policies, their implementation measures and the contribution of these to development has been gaining attention recently. Due to the shared objectives of CCA and particularly Disaster Risk Reduction (DRR), a component of DRM, their integration provides many benefits. At the implementation level, DRR and CCA are usually integrated. Policy integration, however, is often lacking. This study presents a novel analysis of the policy integration of DRR and CCA by 1) suggesting a definition for their integration at a general and further at horizontal and vertical levels, 2) using an analysis framework for policy integration cycle, which separates the policy formulation and implementation processes, and 3) applying these to a case study in Zambia. Moreover, the study identifies the key gaps in the integration process, obtains an understanding of identified key factors for creating an enabling environment for the integration, and provides recommendations for further progress. The study is based on a document analysis of the relevant DRM, climate change (CC), agriculture, forestry, water management and meteorology policy documents and Acts, and 21 semi-structured interviews with key stakeholders. Horizontal integration has occurred both ways, as the revised DRM policy draft has incorporated CCA, and the new CC policy draft has incorporated DRR. This is not necessarily an optimal strategy and unless carefully implemented, it may create pressure on institutional structures and duplication of efforts in the implementation. Much less vertical integration takes place, and where it does, no guidance on how potential goal conflicts with sectorial and development objectives ought to be handled. The objectives of the instruments show convergence. At the programme stage, the measures are fully integrated as they can be classified as robust CCA measures, providing benefits in the current and future

  8. Chemically Integrated Inorganic-Graphene Two-Dimensional Hybrid Materials for Flexible Energy Storage Devices.

    Science.gov (United States)

    Peng, Lele; Zhu, Yue; Li, Hongsen; Yu, Guihua

    2016-12-01

    State-of-the-art energy storage devices are capable of delivering reasonably high energy density (lithium ion batteries) or high power density (supercapacitors). There is an increasing need for these power sources with not only superior electrochemical performance, but also exceptional flexibility. Graphene has come on to the scene and advancements are being made in integration of various electrochemically active compounds onto graphene or its derivatives so as to utilize their flexibility. Many innovative synthesis techniques have led to novel graphene-based hybrid two-dimensional nanostructures. Here, the chemically integrated inorganic-graphene hybrid two-dimensional materials and their applications for energy storage devices are examined. First, the synthesis and characterization of different kinds of inorganic-graphene hybrid nanostructures are summarized, and then the most relevant applications of inorganic-graphene hybrid materials in flexible energy storage devices are reviewed. The general design rules of using graphene-based hybrid 2D materials for energy storage devices and their current limitations and future potential to advance energy storage technologies are also discussed.

  9. Switching Characteristics of Phase Change Memory Cell Integrated with Metal-Oxide Semiconductor Field Effect Transistor

    Institute of Scientific and Technical Information of China (English)

    XU Cheng; CHEN Bomy; LIU Bo; CHEN Yi-Feng; LIANG Shuang; SONG Zhi-Tang; FENG Song-Lin; WAN Xu-Dong; YANG Zuo-Ya; XIE Joseph

    2008-01-01

    A Ge2Sb2Te5 based phase change memory device cell integrated with metal-oxide semiconductor field effect transistor (MOSFET) is fabricated using standard 0.18 μm complementary metal-oxide semiconductor process technology.It shows steady switching characteristics in the dc current-voltage measurement.The phase changing phenomenon from crystalline state to amorphous state with a voltage pulse altitude of 2.0 V and pulse width of 50 ns is also obtained.These results show the feasibility of integrating phase change memory cell with MOSFET.

  10. Matrix changes and side effects induced by electrokinetic treatment of porous and particulate materials

    DEFF Research Database (Denmark)

    Skibsted, Gry

    of porous stone materials to hinder decay. However, in addition to the removal of target ions in these systems, matrix changes may occur during the electrochemical treatment. For a broader implementation of the electrokinetic methods it is important to understand changes in the matrix composition...... for different types of materials. The overall aim of this PhD-project is to evaluate matrix changes and side effects induced by electrokinetic treatment of porous and particulate materials.During electro-remediation protons are produced at the anode and hydroxyl ions are produced at the cathode. The consequent...

  11. Structural Integrity Evaluation of Cold Neutron Laboratory Building by Design Change of Guide Shielding Room

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Sangik; Kim, Youngki; Kim, Harkrho

    2007-06-15

    This report summarizes the results of the structural integrity evaluation for the cold neutron laboratory building by design change of guide shielding room. The design of the guide shielding room was changed by making its structure members in normal concrete (2.3 g/cc) instead of heavy concrete (3.5 g/cc) because the heavy concrete could be not supplied to meet its design specification. Therefore, it was decided that the guide shielding room is made of the normal concrete. And, the shielding performance of the normal concrete was recalculated to confirm satisfying its design specification, which is of a 9000 zone according to HANARO radiation region classification. The change makes the shielding wall thicker than existing design, and then it is caused to qualify the structural integrity evaluation of the CNLB. Finally, the structural integrity of the CNLB was re-evaluated by considering the design change of the guide shielding room.

  12. Virtual Welded-Joint Design Integrating Advanced Materials and Processing Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Z.; Dong, P.; Liu, S.; Babu, S.; Olson, G.; DebRoy, T.

    2005-04-15

    The primary goal of this project is to increase the fatigue life of a welded-joint by 10 times and to reduce energy use by 25% through product performance and productivity improvements using an integrated modeling approach. The fatigue strength of a welded-joint is currently the bottleneck to design high performance and lightweight welded structures using advanced materials such as high strength steels. In order to achieve high fatigue strength in a welded-joint it is necessary to manage the weld bead shape for lower stress concentration, produce preferable residual stress distribution, and obtain the desired microstructure for improved material toughness and strength. This is a systems challenge that requires the optimization of the welding process, the welding consumable, the base material, as well as the structure design. The concept of virtual welded-joint design has been proposed and established in this project. The goal of virtual welded-joint design is to develop a thorough procedure to predict the relationship of welding process, microstructure, property, residual stress, and the ultimate weld fatigue strength by a systematic modeling approach. The systematic approach combines five sub-models: weld thermal-fluid model, weld microstructure model, weld material property model, weld residual stress model, and weld fatigue model. The systematic approach is thus based on interdisciplinary applied sciences including heat transfer, computational fluid dynamics, materials science, engineering mechanics, and material fracture mechanics. The sub-models are based on existing models with further development. The results from modeling have been validated with critical experiments. The systematic modeling approach has been used to design high fatigue resistant welds considering the combined effects of weld bead geometry, residual stress, microstructure, and material property. In particular, a special welding wire has been developed in this project to introduce

  13. Translucency changes of direct esthetic restorative materials after curing, aging and treatment.

    Science.gov (United States)

    Lee, Yong-Keun

    2016-11-01

    The purpose of this article was to review the changes in translucency of direct esthetic restorative materials after curing, aging and treatment. As a criterion for the evaluation of clinical translucency changes, visual perceptibility threshold in translucency parameter difference (ΔTP) of 2 was used. Translucency changes after curing were perceivable depending on experimental methods and products (largest ΔTP in resin composites = 15.9). Translucency changes after aging were reported as either relatively stable or showed perceivable changes by aging protocols (largest ΔTP in resin composites = -3.8). Translucency changes after curing, aging and treatment were perceivable in several products and experimental methods. Therefore, shade matching of direct esthetic materials should be performed considering these instabilities of translucency in direct esthetic materials.

  14. Integrating Climate Change Science and Sustainability in Environmental Science, Sociology, Philosophy and Business Courses.

    Science.gov (United States)

    Boudrias, M. A.; Cantzler, J.; Croom, S.; Huston, C.; Woods, M.

    2015-12-01

    Courses on sustainability can be taught from multiple perspectives with some focused on specific areas (environmental, socio-cultural, economic, ethics) and others taking a more integrated approach across areas of sustainability and academic disciplines. In conjunction with the Climate Change Education Program efforts to enhance climate change literacy with innovative approaches, resources and communication strategies developed by Climate Education Partners were used in two distinct ways to integrate climate change science and impacts into undergraduate and graduate level courses. At the graduate level, the first lecture in the MBA program in Sustainable Supply Chain Management is entirely dedicated to climate change science, local and global impacts and discussions about key messages to communicate to the business community. Basic science concepts are integrated with discussions about mitigation and adaptation focused on business leaders. The concepts learned are then applied to the semester-long business plan project for the students. At the undergraduate level, a new model of comprehensive integration across disciplines was implemented in Spring 2015 across three courses on Sustainability each with a specific lens: Natural Science, Sociology and Philosophy. All three courses used climate change as the 'big picture' framing concept and had similar learning objectives creating a framework where lens-specific topics, focusing on depth in a discipline, were balanced with integrated exercises across disciplines providing breadth and possibilities for integration. The comprehensive integration project was the creation of the climate action plan for the university with each team focused on key areas of action (water, energy, transportation, etc.) and each team built with at least one member from each class ensuring a natural science, sociological and philosophical perspective. The final project was presented orally to all three classes and an integrated paper included

  15. Experimental study of passive cooling of building facade using phase change materials to increase thermal comfort in buildings in hot humid areas

    Directory of Open Access Journals (Sweden)

    A. A. Madhumathi, B. M.C. Sundarraja

    2012-01-01

    Full Text Available Storage of cooler night temperatures using Phase Change Material (PCM energy storage technique, for cooling of ambient air during hot day times can be an alternate of current cooling techniques in building sector. This work presents the results of an experimental set-up to test energy saving potential of phase change materials with typical construction materials in building facade in Hot-Humid Climatic Regions in real conditions. The main objective of this research is to demonstrate experimentally that it is possible to improve the thermal comfort and reduce the energy consumption of a building without substantial increase in the weight of the construction materials with the inclusion of PCM. This research was conducted to study and evaluate the performance of the existing materials integrated with Organic PCM Polyethylene glycol (PEG E600. This research suggested that the heat gain is significantly reduced when the PCM is incorporated into the brick (conventional building material.

  16. Climate Change Education as an Integral Part of the United Nations Framework Convention on Climate Change

    Science.gov (United States)

    Journal of Education for Sustainable Development, 2012

    2012-01-01

    The United Nations Framework Convention on Climate Change (UNFCCC), through its Article 6, and the Convention's Kyoto Protocol, through its Article 10 (e), call on governments to develop and implement educational programmes on climate change and its effects. In particular, Article 6 of the Convention, which addresses the issue of climate…

  17. Integrating Water into an Economic Assessment of Climate Change Impacts on Egypt

    OpenAIRE

    Yates, D

    1996-01-01

    Recent research indicates that larger countries, with multiple agro-climatic zones, have the capacity to adjust to marginal climate changes which could occur over the next century. However, in countries with fewer adaptation options and with increasing dependency on imports to meet growing domestic demands, climate change might have significant impacts. To date, little has been done on assessing integrated impacts of climate change in developing countries. This motivates the need for imp...

  18. Multi-material additive manufacturing of robot components with integrated sensor arrays

    Science.gov (United States)

    Saari, Matt; Cox, Bryan; Galla, Matt; Krueger, Paul S.; Richer, Edmond; Cohen, Adam L.

    2015-06-01

    Fabricating a robotic component comprising 100s of distributed, connected sensors can be very difficult with current approaches. To address these challenges, we are developing a novel additive manufacturing technology to enable the integrated fabrication of robotic structural elements with distributed, interconnected sensors and actuators. The focus is on resistive and capacitive sensors and electromagnetic actuators, though others are anticipated. Anticipated applications beyond robotics include advanced prosthetics, wearable electronics, and defense electronics. This paper presents preliminary results for printing polymers and conductive material simultaneously to form small sensor arrays. Approaches to optimizing sensor performance are discussed.

  19. Integrated synthesis of poly(o-phenylenediamine)-derived carbon materials for high performance supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Hui; Wang, Xiaolei; Liu, Xuexia; Yang, Xiurong [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022 (China)

    2012-12-18

    Poly(o-phenylenediamine) (POPD)-derived functional carbon materials with excellent capacitive performance are successfully synthesized by means of an integrated one-step process, in which FeCl{sub 3} not only oxidizes the polymerization of the organic monomers but also activates the carbonization. Furthermore, extensive research has proved that this strategy to discover novel carbons is useful not only for capacitors but also for other energy storage/conversion devices. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Integration of III-V materials and Si-CMOS through double layer transfer process

    Science.gov (United States)

    Lee, Kwang Hong; Bao, Shuyu; Fitzgerald, Eugene; Tan, Chuan Seng

    2015-03-01

    A method to integrate III-V compound semiconductor and SOI-CMOS on a common Si substrate is demonstrated. The SOI-CMOS layer is temporarily bonded on a Si handle wafer. Another III-V/Si substrate is then bonded to the SOI-CMOS containing handle wafer. Finally, the handle wafer is released to realize the SOI-CMOS on III-V/Si hybrid structure on a common substrate. Through this method, high temperature III-V materials growth can be completed without the presence of the temperature sensitive CMOS layer, hence damage to the CMOS layer is avoided.

  1. Quantifying the effects of climate change and land use change on water resources in Denmark using an integrated watershed model

    DEFF Research Database (Denmark)

    Van Roosmalen, Lieke Petronella G; Sonnenborg, Torben; Jensen, Karsten Høgh

    2009-01-01

    This paper presents a quantitative comparison of plausible climate and land use change impacts on the hydrology of a large-scale agricultural catchment. An integrated, distributed hydrological model was used to simulate changes in the groundwater system and its discharge to rivers and drains...... to current values. Changing the land use from grass to forest had a minor effect on groundwater recharge, whereas CO2 effects on transpiration resulted in a relatively large increase in recharge. This study has shown that climate change has the most substantial effect on the hydrology in this catchment......, whereas other factors such as irrigation, CO2 effects on transpiration, and land use changes affect the water balance to a lesser extent....

  2. Experimental Investigation on the Effect of Phase Change Materials on Compressed Air Expansion in CAES Plants

    Directory of Open Access Journals (Sweden)

    Beatrice Castellani

    2015-07-01

    Full Text Available The integration of renewable energy in the electrical grid is challenging due to the intermittent and non-programmable generated electric power and to the transmission of peak power levels. Several energy storage technologies have been studied to find a solution to these issues. In particular, compressed air energy storage (CAES plants work by pumping and storing air into a vessel or in an underground cavern; then when energy is needed, the pressurized air is expanded in an expansion turbine. Several CAES configurations have been proposed: diabatic, adiabatic and isothermal. The isothermal process seems to be the most promising to improve the overall efficiency. It differs from conventional CAES approaches as it employs near-isothermal compression and expansion. Currently, there are no commercial isothermal CAES implementations worldwide, but several methods are under investigation. In this paper, the use of phase change materials (PCM for isothermal air expansion is discussed. Air expansion tests in presence of PCM were carried out in a high-pressure vessel in order to analyze the effect of PCM on the process. Results show that in presence of PCM near isothermal expansion conditions occur and therefore they affect positively the value of the obtainable expansion work.

  3. Emission energy control of semiconductor quantum dots using phase change material

    Science.gov (United States)

    Kanazawa, Shohei; Sato, Yu; Yamamura, Ariyoshi; Saiki, Toshiharu

    2015-03-01

    Semiconductor quantum dots have paid much attention as it is a promising candidate for quantum, optical devices, such as quantum computer and quantum dot laser. We propose a local emission energy control method of semiconductor quantum dots using applying strain by volume expansion of phase change material. Phase change material can change its phase crystalline to amorphous, and the volume expand by its phase change. This method can control energy shift direction and amount by amorphous religion and depth. Using this method, we matched emission energy of two InAs/InP quantum dots. This achievement can connect to observing superradiance phenomenon and quantum dot coupling effect.

  4. The role of vacancies and local distortions in the design of new phase-change materials.

    Science.gov (United States)

    Wuttig, Matthias; Lüsebrink, Daniel; Wamwangi, Daniel; Wełnic, Wojciech; Gillessen, Michael; Dronskowski, Richard

    2007-02-01

    Phase-change materials are of tremendous technological importance ranging from optical data storage to electronic memories. Despite this interest, many fundamental properties of phase-change materials, such as the role of vacancies, remain poorly understood. 'GeSbTe'-based phase-change materials contain vacancy concentrations around 10% in their metastable crystalline structure. By using density-functional theory, the origin of these vacancies has been clarified and we show that the most stable crystalline phases with rocksalt-like structures are characterized by large vacancy concentrations and local distortions. The ease by which vacancies are formed is explained by the need to annihilate energetically unfavourable antibonding Ge-Te and Sb-Te interactions in the highest occupied bands. Understanding how the interplay between vacancies and local distortions lowers the total energy helps to design novel phase-change materials as evidenced by new experimental data.

  5. Microencapsulation of butyl stearate as a phase change material by interfacial polycondensation in a polyurea system

    Energy Technology Data Exchange (ETDEWEB)

    Chen Liang [College of Material Science and Engineering, Nanjing University of Technology, Nanjing 210009 (China)], E-mail: doseng_1982@hotmail.com; Xu Lingling; Shang Hongbo; Zhang Zhibin [College of Material Science and Engineering, Nanjing University of Technology, Nanjing 210009 (China)

    2009-03-15

    For the last 20 years, microencapsulated phase change materials (MicroPCMs), which combine microencapsulation technology and phase change material, have been attracted more and more interest. By overcoming some limitations of the PCMs, the MicroPCMs improve the efficiency of PCMs and make it possible to apply PCMs in many areas. In this experiment, polyurea microcapsules containing phase change materials were prepared using interfacial polycondensation method. Toluene-2,4-diisocyanate (TDI) and ethylenediamine (EDA) were chosen as monomers. Butyl stearate was employed as a core material. The MicroPCMs' properties have been characterized by dry weight analysis, differential scanning calorimetry, Fourier transform IR spectra analysis and optical microscopy. The results show that the MicroPCMs were synthesized successfully and that, the phase change temperature was about 29 deg. C, the latent heat of fusion was about 80 J g{sup -1}, the particle diameter was 20-35 {mu}m.

  6. Microencapsulation of butyl stearate as a phase change material by interfacial polycondensation in a polyurea system

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Chen; Lingling, Xu; Hongbo, Shang; Zhibin, Zhang [College of Material Science and Engineering, Nanjing University of Technology, Nanjing 210009 (China)

    2009-03-15

    For the last 20 years, microencapsulated phase change materials (MicroPCMs), which combine microencapsulation technology and phase change material, have been attracted more and more interest. By overcoming some limitations of the PCMs, the MicroPCMs improve the efficiency of PCMs and make it possible to apply PCMs in many areas. In this experiment, polyurea microcapsules containing phase change materials were prepared using interfacial polycondensation method. Toluene-2,4-diisocyanate (TDI) and ethylenediamine (EDA) were chosen as monomers. Butyl stearate was employed as a core material. The MicroPCMs' properties have been characterized by dry weight analysis, differential scanning calorimetry, Fourier transform IR spectra analysis and optical microscopy. The results show that the MicroPCMs were synthesized successfully and that, the phase change temperature was about 29 C, the latent heat of fusion was about 80 J g{sup -1}, the particle diameter was 20-35 {mu}m. (author)

  7. HEAT STORAGE SYSTEM WITH PHASE CHANGE MATERIALS IN COGENERATION UNITS: STUDY OF PRELIMINARY MODEL

    Directory of Open Access Journals (Sweden)

    Claudio Caprara

    2008-12-01

    Full Text Available The continuous increase in the mechanization of farm activities, the rise in fuel prices and the environmental aspects concerning gas emissions are the main driving forces behind efforts toward more effective use of renewable energy sources and cogeneration systems even in agricultural and cattle farms. Nevertheless these systems are still not very suitable for this purpose because of their little flexibility in following the changing energy demand as opposed to the extremely various farm load curves, both in daytime and during the year. In heat recovery systems, the available thermal energy supply is always linked to power production, thus it does not usually coincide in time with the heat demand. Hence some form of thermal energy storage (TES is necessary in order to reach the most effective utilization of the energy source. This study deals with the modelling of a packed bed latent heat TES unit, integrating a cogeneration system made up of a reciprocating engine. The TES unit contains phase change materials (PCMs filled in spherical capsules, which are packed in an insulated cylindrical storage tank. Water is used as heat transfer fluid (HTF to transfer heat from the tank to the final uses, and exhausts from the engine are used as thermal source. PCMs are considered especially for their large heat storage capacity and their isothermal behaviour during the phase change processes. Despite their high energy storage density, most of them have an unacceptably low thermal conductivity, hence PCMs encapsulation technique is adopted in order to improve heat transfer. The special modular configuration of heat exchange tubes and the possibility of changing water flow through them allow to obtain the right amount of thermal energy from the tank, according to the hourly demand of the day. The model permits to choose the electrical load of the engine, the dimensions of the tank and the spheres, thickness and diameter of heat exchanger and the nature of

  8. Riemann integration via primitives for a new proof to the change of variable theorem

    CERN Document Server

    Pouso, Rodrigo López

    2011-01-01

    We approach the Riemann integral via generalized primitives to give a new proof for a general result on change of variable originally proven by Kestelman and Davies. Our proof is similar to Kestelman's, but we hope readers will find it clearer thanks to the use of a new test for the Riemann integrability (which we introduce in this paper) along with some ingredients from some other more recent proofs available in the literature. We also include a bibliographical review of related results and proofs. Although this paper emphasizes in the change of variable theorem, our contributions to the Riemann integration theory are of independent interest. For instance, we present a very simple proof to the fact that continuous functions are integrable which avoids the use of uniform continuity.

  9. A J integral based method to measure fracture resistance and cohesive laws in materials exhibiting large scale plasticity

    DEFF Research Database (Denmark)

    Sørensen, Bent F.; Goutianos, Stergios

    2014-01-01

    A method is developed to extract the fracture resistance and mode I cohesive law of nonlinear elastic-plastic materials using a Double Cantilever Beam (DCB) sandwich specimen loaded with pure bending moments. The method is based on the J integral which is valid for materials having a non-linear s......A method is developed to extract the fracture resistance and mode I cohesive law of nonlinear elastic-plastic materials using a Double Cantilever Beam (DCB) sandwich specimen loaded with pure bending moments. The method is based on the J integral which is valid for materials having a non...

  10. Ru/Al Multilayers Integrate Maximum Energy Density and Ductility for Reactive Materials.

    Science.gov (United States)

    Woll, K; Bergamaschi, A; Avchachov, K; Djurabekova, F; Gier, S; Pauly, C; Leibenguth, P; Wagner, C; Nordlund, K; Mücklich, F

    2016-01-01

    Established and already commercialized energetic materials, such as those based on Ni/Al for joining, lack the adequate combination of high energy density and ductile reaction products. To join components, this combination is required for mechanically reliable bonds. In addition to the improvement of existing technologies, expansion into new fields of application can also be anticipated which triggers the search for improved materials. Here, we present a comprehensive characterization of the key parameters that enables us to classify the Ru/Al system as new reactive material among other energetic systems. We finally found that Ru/Al exhibits the unusual integration of high energy density and ductility. For example, we measured reaction front velocities up to 10.9 (± 0.33) ms(-1) and peak reaction temperatures of about 2000 °C indicating the elevated energy density. To our knowledge, such high temperatures have never been reported in experiments for metallic multilayers. In situ experiments show the synthesis of a single-phase B2-RuAl microstructure ensuring improved ductility. Molecular dynamics simulations corroborate the transformation behavior to RuAl. This study fundamentally characterizes a Ru/Al system and demonstrates its enhanced properties fulfilling the identification requirements of a novel nanoscaled energetic material.

  11. Integrating global energy and climate governance: The changing role of the International Energy Agency

    OpenAIRE

    Heubaum, Harald; Biermann, Frank

    2015-01-01

    Despite the long-recognized interlinkages between global energy consumption and climate change, there has historically been only limited policy interaction, let alone integration, between the two fields. This compartmentalization is mirrored in scholarship, where much research has focused on the fragmentation of, respectively, global energy and global climate governance, but only little has been said about how these fields might be integrated. Our analysis of the International Energy Agency’s...

  12. Interface Characterization of Metals and Metal-nitrides to Phase Change Materials

    NARCIS (Netherlands)

    Roy, Deepu; Wolters, Rob A.M.

    2011-01-01

    We have investigated the interfacial contact properties of the CMOS compatible electrode materials W, TiW, Ta, TaN and TiN to doped-Sb2Te phase change material (PCM). This interface is characterized both in the amorphous and in the crystalline state of the doped-Sb2Te. The electrical nature of the i

  13. Application of shape changing smart materials in household appliances: A fragmented and inconsistent uptake

    NARCIS (Netherlands)

    Bin Kassim, A.; Horvath, I.; Gerritsen, B.H.M.

    2014-01-01

    Shape changing smart materials (SCSM) have a wide range of applications, supporting product functions through material features. Surprisingly, their application in consumer durables such as household appliances is not as expected. This phenomenon could be related to a possible SCSM knowledge gap amo

  14. China's Changing Economic Structure and Implications for Regional Patterns of Trade, Production and Integration

    Institute of Scientific and Technical Information of China (English)

    Kim Song Tan; Hoe Ee Khor

    2006-01-01

    Without intending to do so, China has in recent years played a major role in East Asia's economic integration. It has done so mainly through the production and supply chain networks it has spun across the region. This paper argues that given the developmental trends in the Chinese economy, the Chinese government should pursue a more active strategy towards a broader and more balanced economic integration with the region. The emergence of a multi-track production structure, increased importance of domestic consumption and the services sector, together with faster integration of the domestic economy,will fundamentally change China's trade and investment relationships with the rest of East Asia and necessitate a review of China's economic integration strategy. The paper also argues that ASEAN can play a useful role in facilitating the region-wide integration process.

  15. Does Integrated Water Resources Management Support Institutional Change? The Case of Water Policy Reform in Israel

    Directory of Open Access Journals (Sweden)

    Itay Fischhendler

    2010-03-01

    Full Text Available Many international efforts have been made to encourage integrated water resources management through recommendations from both the academic and the aid and development sectors. Recently, it has been argued that integrated water resources management can help foster better adaptation of management and policy responses to emerging water crises. Nevertheless, few empirical studies have assessed how this type of management works in practice and what an integrated water management system implies for institutional adaptation and change. Our assessment of the Israeli water sector provides one view of how they can be shaped by an integrated structure in the water sector. Our analysis of recent efforts to adapt Israel's water management system to new conditions and uncertainties reveals that the interconnectedness of the system and the consensus decision-making process, led by a dominant actor who coordinates and sets the policy agenda, tends to increase the complexity of negotiations. In addition, the physical integration of water management leads to sunk costs of large-scale physical infrastructure. Both these factors create a path dependency that empowers players who receive benefits from maintaining the existing system. This impedes institutional reform of the water management system and suggests that integrated water resources management creates policy and management continuity that may only be amenable to incremental changes. In contrast, real adaptation that requires reversibility and the ability to change management strategies in response to new information or monitoring of specific management outcomes.

  16. An integrated design of the payload for Chang'e 3 Lunar Rover

    Science.gov (United States)

    Zhouchangyi, Zhouchangyi

    Chang’e 3 detector is launched in China Xichang Satellite Launch Center on December 2, 2013. Its project task was a complete success. CE-3 detector achieved a soft landing and started its lunar exploration andinspection. It is composed of the lander and Rover (Yutu). This paper introduces an integrated designing payload of Chang’e 3 Lunar Rover. Chang’e 3 Lunar Rover is allocated with infrared imaging spectrometer,moon-measuring radar, Alpha Particle X-ray Spectrometer(APXS), panoramic camera and other payloads. The infrared spectrometer is used to analyse the infrared spectrum and take images of the patrolling areas, to analyse the mineral composition and distribution of the lunar surface, and to do a comprehensive study of the energy sources and mineral sources.The radar is used for inspecting the thickness and structure of the lunar soil on the patrolling path as well as probing the structure of the shallow lunar crust. The APXS will use the method of alpha-particle-induced X-ray fluorescence to study in detail the composition of soil in specific areas. The panoramic camera is for obtaining three-dimensional images of the lunar surface around the patrolling path, accomplishing the inspection of near landscapes and topographic analysis. Limited by the total weight, the Rover is equipped with a payload controller, through which an integrated design consisting of the power supply, data processing, electronic units, operating management and other functions of the payload is done, to realize the centralized power supply, centralized management, centralized data processing, centralized operating controlling and centralized interfaces with the integrated electronic system of the Rover.

  17. Investigations on the Impact of Material-Integrated Sensors with the Help of FEM-Based Modeling

    Directory of Open Access Journals (Sweden)

    Gerrit Dumstorff

    2015-01-01

    Full Text Available We present investigations on the impact of material-integrated sensors with the help of finite element-based modeling. A sensor (inlay integrated with a material (matrix is always a foreign body in the material, which can lead to a “wound effect”, that is degradation of the macroscopic behavior of a material. By analyzing the inlay’s impact on the material in terms of mechanical load, heat conduction, stress during integration and other impacts of integration, this wound effect is analyzed. For the mechanical load, we found out that the inlay has to be at least as stretchable and bendable as the matrix. If there is a high thermal load during integration, the coefficients of the thermal expansion of the inlay have to be matched to the matrix. In the case of a high thermal load during operation, the inlay has to be as thin as possible or its thermal conductivity has to be adapted to the thermal conductivity of the matrix. To have a general view of things, the results are dimensionless and independent of the geometry. In each section, the results are illustrated by examples. Based on all of the results, we present our idea for the fabrication of future material-integrated sensors.

  18. Review on thermal energy storage with phase change: materials, heat transfer analysis and applications

    Energy Technology Data Exchange (ETDEWEB)

    Zalba, Belen; Marin, Jose M. [Dpto. Ingenieria Mecanica, Campus Politecnico, Universidad de Zaragoza, EUITIZ ' EDIFICIO B.3' Maria de Luna 3 (Actur), 50015, Zaragoza (Spain); Cabeza, Luisa F. [Dpt.d' Informatica i Enginyeria Industrial, Escola, Universitaria Politecnica, Universitat de Lleida, CREA, Jaurne 11,69,25001, Lleida (Spain); Mehling, Harald [ZAE Bayem, Division 1: Energy Conversion and Storage, Walther-Meissner-Str. 6, 85748, Garching (Germany)

    2003-02-01

    Thermal energy storage in general, and phase change materials (PCMs) in particular, have been a main topic in research for the last 20 years, but although the information is quantitatively enormous, it is also spread widely in the literature, and difficult to find. In this work, a review has been carried out of the history of thermal energy storage with solid-liquid phase change. Three aspects have been the focus of this review: materials, heat transfer and applications. The paper contains listed over 150 materials used in research as PCMs, and about 45 commercially available PCMs. The paper lists over 230 references. (Author)

  19. Heat transfer and parametric studies of an encapsulated phase change material based cool thermal energy storage system

    Institute of Scientific and Technical Information of China (English)

    CHERALATHAN M.; VELRAJ R.; RENGANARAYANAN S.

    2006-01-01

    This work investigates the transient behaviour of a phase change material based cool thermal energy storage (CTES)system comprised of a cylindrical storage tank filled with encapsulated phase change materials (PCMs) in spherical container integrated with an ethylene glycol chiller plant. A simulation program was developed to evaluate the temperature histories of the heat transfer fluid (HTF) and the phase change material at any axial location during the charging period. The results of the model were validated by comparison with experimental results of temperature profiles of HTF and PCM. The model was also used to investigate the effect of porosity, Stanton number, Stefan number and Peclet number on CTES system performance. The results showed that increase in porosity contributes to a higher rate of energy storage. However, for a given geometry and heat transfer coefficient, the mass of PCM charged in the unit decreases as the increase in porosity. The St number as well as the Ste number is also influential in the performance of the unit. The model is a convenient and more suitable method to determine the heat transfer characteristics of CTES system. The results reported are much useful for designing CTES system.

  20. Integration of calcium and chemical looping combustion using composite CaO/CuO-based materials.

    Science.gov (United States)

    Manovic, Vasilije; Anthony, Edward J

    2011-12-15

    Calcium looping cycles (CaL) and chemical looping combustion (CLC) are two new, developing technologies for reduction of CO(2) emissions from plants using fossil fuels for energy production, which are being intensively examined. Calcium looping is a two-stage process, which includes oxy-fuel combustion for sorbent regeneration, i.e., generation of a concentrated CO(2) stream. This paper discuss the development of composite materials which can use copper(II)-oxide (CuO) as an oxygen carrier to provide oxygen for the sorbent regeneration stage of calcium looping. In other words, the work presented here involves integration of calcium looping and chemical looping into a new class of postcombustion CO(2) capture processes designated as integrated CaL and CLC (CaL-CLC or Ca-Cu looping cycles) using composite pellets containing lime (CaO) and CuO together with the addition of calcium aluminate cement as a binder. Their activity was tested in a thermogravimetric analyzer (TGA) during calcination/reduction/oxidation/carbonation cycles. The calcination/reduction typically was performed in methane (CH(4)), and the oxidation/carbonation stage was carried out using a gas mixture containing both CO(2) and O(2). It was confirmed that the material synthesized is suitable for the proposed cycles; with the very favorable finding that reduction/oxidation of the oxygen carrier is complete. Various schemes for the Ca-Cu looping process have been explored here that would be compatible with these new composite materials, along with some different possibilities for flow directions among carbonator, calciner, and air reactor.

  1. The use of lipids as phase change materials for thermal energy storage

    Science.gov (United States)

    Phase change materials (PCMs) are substances capable of absorbing and releasing large 2 amounts of thermal energy (heat or cold) as latent heat over constant temperature as they 3 undergo a change in state of matter (phase transition), commonly, between solid and 4 liquid phases. Since the late 194...

  2. Experimental data showing the thermal behavior of a flat roof with phase change material

    Directory of Open Access Journals (Sweden)

    Ayça Tokuç

    2015-12-01

    Full Text Available The selection and configuration of building materials for optimal energy efficiency in a building require some assumptions and models for the thermal behavior of the utilized materials. Although the models for many materials can be considered acceptable for simulation and calculation purposes, the work for modeling the real time behavior of phase change materials is still under development. The data given in this article shows the thermal behavior of a flat roof element with a phase change material (PCM layer. The temperature and energy given to and taken from the building element are reported. In addition the solid–liquid behavior of the PCM is tracked through images. The resulting thermal behavior of the phase change material is discussed and simulated in [1] A. Tokuç, T. Başaran, S.C. Yesügey, An experimental and numerical investigation on the use of phase change materials in building elements: the case of a flat roof in Istanbul, Build. Energy, vol. 102, 2015, pp. 91–104.

  3. Facilitative Project Management: Constructing A Model For Integrated Change Implementation By Utilizing Case Studies

    Directory of Open Access Journals (Sweden)

    Veronica Hodgson

    2003-11-01

    Full Text Available Change management theory is extensive, and organisations constantly adapt to and embrace change. In post-apartheid South Africa we are building a racially integrated business environment and society, and leverage its competitive re-entry into the world business arena. Research to date has found that the majority of change initiatives fail due to resistance caused by poor conceptualisation and planning, and the lack of proper integration of the people and business dimensions of change. The model to implement a successful change program will be designed using a combination of readily available skills and techniques. Its development and testing will take place within the context of three case studies. OpsommingDie teorie van veranderingsbestuur is omvattend. Organisasies moet op konstante wyse daarby aanpas en dit integreer. In Post-Apartheid Suid-Afrika bou ons tans ’n ras geïntegreerde besigheidsomgewing en gemeenskap, en benut dit maksimaal in ons toetrede tot die mededingende wêreld besigheidsarena. Huidige navorsing het bevind dat die meeste veranderingsinitiatiewe faal weens weerstand teen verandering wat deur swak konseptualisering en beplanning, en ’n gebrek aan behoorlike integrering van mense en die besigheidsdimensies van verandering veroorsaak is. Die model om ’n suksesvolle veranderingsprogram te implementeer, sal ontwerp word met geredelik beskikbare vaardighede en tegnieke. Die ontwikkeling en toetsing sal binne die konteks van drie gevallestudies plaasvind.

  4. Integrated assessment of vulnerability to climate change and options for adaptation in the Netherlands

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, K.; Kuikman, P.J.; Veraart, J.A.; Van Walsum, P.E.V.; Westein, E. [Alterra, Wageningen, and International Centre for Integrative Studies, Maastricht University, Maastricht (Netherlands); Verhagen, A. [Plant Research International, Wageningen (Netherlands); Daan, N. [Netherlands Institute for Fisheries Research RIVO, IJmuiden (Netherlands); Van Ierland, E.C.; Szoenyi, J. [Environmental Economics and Natural Resources Group, Wageningen UR, Wageningen (Netherlands); De Groot, R.S.; Van Vliet, A. [Environmental Systems Analysis Group, Wageningen UR, Wageningen (Netherlands); Martens, P.; Amelung, B.; Huynen, M. [International Centre for Integrative Studies, Maastricht (Netherlands)

    2002-06-01

    In recent decades it has become increasingly clear that the global climate is warming and that regional climates are changing. The changes include alterations in rainfall pattern and intensities, sea level, and the frequencies of extreme weather events. Climate changes will not just have global effects, they will also occur regionally. The consequences will be felt and dealt with in our own region. In addition to studies at the European level, a study entitled 'An integrated assessment of vulnerability to climate change and adaptation options in the Netherlands' was carried out.

  5. MSE-THERMO: Integrated computer system for application of chemical thermodynamics in materials science and engineering

    Energy Technology Data Exchange (ETDEWEB)

    Leitner, J.; Chuchvalec, P.; Vonka, P. [Inst. of Chemical Technology, Prague (Czech Republic)

    1995-08-01

    MSE-THERMO is an integrated computer system embodying thermochemical databases with sophisticated computational software for diverse thermodynamic calculations. It consists of a database MSE-DATA, where thermodynamic data for pure substances are stored, as well as programs for the calculation of thermodynamic functions of pure substances, changes of thermodynamic functions for chemical reactions, ternary phase diagrams in a subsolidus region, phase stability diagrams, and equilibrium composition of multicomponents and multiphases systems. Datafiles as well as computational software tools are at present intensively extended.

  6. Integrating Hazardous Materials Characterization and Assessment Tools to Guide Pollution Prevention in Electronic Products and Manufacturing

    Science.gov (United States)

    Lam, Carl

    Due to technology proliferation, the environmental burden attributed to the production, use, and disposal of hazardous materials in electronics have become a worldwide concern. The major theme of this dissertation is to develop and apply hazardous materials assessment tools to systematically guide pollution prevention opportunities in the context of electronic product design, manufacturing and end-of-life waste management. To this extent, a comprehensive review is first provided on describing hazard traits and current assessment methods to evaluate hazardous materials. As a case study at the manufacturing level, life cycle impact assessment (LCIA)-based and risk-based screening methods are used to quantify chemical and geographic environmental impacts in the U.S. printed wiring board (PWB) industry. Results from this industrial assessment clarify priority waste streams and States to most effectively mitigate impact. With further knowledge of PWB manufacturing processes, select alternative chemical processes (e.g., spent copper etchant recovery) and material options (e.g., lead-free etch resist) are discussed. In addition, an investigation on technology transition effects for computers and televisions in the U.S. market is performed by linking dynamic materials flow and environmental assessment models. The analysis forecasts quantities of waste units generated and maps shifts in environmental impact potentials associated with metal composition changes due to product substitutions. This insight is important to understand the timing and waste quantities expected and the emerging toxic elements needed to be addressed as a consequence of technology transition. At the product level, electronic utility meter devices are evaluated to eliminate hazardous materials within product components. Development and application of a component Toxic Potential Indicator (TPI) assessment methodology highlights priority components requiring material alternatives. Alternative

  7. Integration of Agricultural Waste in Local Building Materials for their Exploitation: Application with Rice Straw

    Directory of Open Access Journals (Sweden)

    D. Sow

    2014-04-01

    Full Text Available Through experiments, we have determined the mechanical and thermal properties of samples. This allowed us to determine the most optimal formulations. Therefore, we have prepared samples constituted by two basic materials, clay and laterite, mixed with rice straw. Thus, agriculture is among the economic sectors that produce more waste. The latter are mainly the straw of the three most-produced cereals in the world: wheat, corn and rice. Concerning rice straw, its high content of cellulose makes it difficult to digest. So, few animals are able to use it as food. Most of the straws are lost, buried, burned or used as litter. Moreover, clay and laterite formations represent the most abundant materials resources in Africa. So, this study has allowed us to show that the integration of rice straw in lateritic and clay soils for its use as building materials will allow, in addition to its recycling, to greatly reduce the social habitat cost and to improve the thermal comfort.

  8. New trends of thermal spray technique in materials recycling and integration

    Institute of Scientific and Technical Information of China (English)

    A.Ohmori; YE Fu-xing

    2004-01-01

    Thermal Spray was invented by Swiss scientist Max Ulrih Schoop in 1919s and became and industrial coating technology used to modify the surface of materials to make them more wear, corrosion or thermally resistant, or to let them have functional properties such as photocatalytic activity.In this lecture, new trends of thermal spray technique in materials recycling and integration are presented.The development status of thermal spray in Joining and Welding Research Institute at Osaka University are also given. The emphases will be made on the smart processing technique, the utilization of plastic materials, and also the special phenomena taking place in it such as implantation of particle to plastic substrate.Furthermore, the smart coating processes relating to the velocity, temperature and the reactive processes in composite powder or powder with plasma or flame are discussed in details. Moreover, the International Thermal Spray Conference & Exhibition open at Osake on May 2004 are introduced and the experience and success are shared.

  9. Material gain engineering in GeSn/Ge quantum wells integrated with an Si platform

    Science.gov (United States)

    Mączko, H. S.; Kudrawiec, R.; Gladysiewicz, M.

    2016-09-01

    It is shown that compressively strained Ge1‑xSnx/Ge quantum wells (QWs) grown on a Ge substrate with 0.1 ≤ x ≤ 0.2 and width of 8 nm ≤ d ≤ 14 nm are a very promising gain medium for lasers integrated with an Si platform. Such QWs are type-I QWs with a direct bandgap and positive transverse electric mode of material gain, i.e. the modal gain. The electronic band structure near the center of Brillouin zone has been calculated for various Ge1‑xSnx/Ge QWs with use of the 8-band kp Hamiltonian. To calculate the material gain for these QWs, occupation of the L valley in Ge barriers has been taken into account. It is clearly shown that this occupation has a lot of influence on the material gain in the QWs with low Sn concentrations (Sn  15%). However, for QWs with Sn > 20% the critical thickness of a GeSn layer deposited on a Ge substrate starts to play an important role. Reduction in the QW width shifts up the ground electron subband in the QW and increases occupation of the L valley in the barriers instead of the Γ valley in the QW region.

  10. Structural properties of the metastable state of phase change materials investigated by synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Merkelbach, Philipp; Eijk, Julia van; Wuttig, Matthias [I. Phys. Institut (IA), RWTH Aachen, 52056 Aachen (Germany); Braun, Carolin [Institut fuer Anorg. Chemie, CAU Kiel, 24098 Kiel (Germany)

    2008-07-01

    Phase change alloys are among the most promising materials for novel data storage devices. Since several years Phase Change Materials based on Ge-Sb-Te- alloys have been used in optical data storage solutions like rewriteable CDs and DVDs. Recently these alloys have been explored as potential candidates for fast nonvolatile electrical data storage devices in Phase Change Random Access Memory (PCRAM). Besides attracting considerable interest from the commercial point of view phase change materials are very interesting also due to their remarkable physical properties. They have the ability to be reversibly switched within a few nanoseconds between the amorphous and the crystalline phase, while changing their physical properties such as optical reflectivity and electrical resistivity significantly. Even though the electronic properties show a drastical contrast such fast transitions can only be caused by small atomic rearrangements. This behavior calls for a deeper understanding of the structural properties of the alloys. We have performed powder diffraction measurements of the crystal phase of various GeSbTe alloys, to determine the structural similarities and differences of several alloys. Understanding the crystal structure of phase change materials is a key to a deeper insight into the properties of these promising materials.

  11. Conceptual Change Text: A Supplementary Material To Facilitate Conceptual Change in Electrochemical Cell Concepts.

    Science.gov (United States)

    Yuruk, Nejla; Geban, Omer

    The main purpose of the study was to investigate the effectiveness of conceptual change text (CCT) oriented instruction over traditionally designed instruction on students' understanding of electrochemical (galvanic and electrolytic) cell concepts. The subjects of the study consisted of 64 students from the two classes of a high school in Turkey.…

  12. Integrated ocean management as a strategy to meet rapid climate change: the Norwegian case.

    Science.gov (United States)

    Hoel, Alf Håkon; Olsen, Erik

    2012-02-01

    The prospects of rapid climate change and the potential existence of tipping points in marine ecosystems where nonlinear change may result from them being overstepped, raises the question of strategies for coping with ecosystem change. There is broad agreement that the combined forces of climate change, pollution and increasing economic activities necessitates more comprehensive approaches to oceans management, centering on the concept of ecosystem-based oceans management. This article addresses the Norwegian experience in introducing integrated, ecosystem-based oceans management, emphasizing how climate change, seen as a major long-term driver of change in ecosystems, is addressed in management plans. Understanding the direct effects of climate variability and change on ecosystems and indirect effects on human activities is essential for adaptive planning to be useful in the long-term management of the marine environment.

  13. Coralline algae (Rhodophyta) in a changing world: integrating ecological, physiological, and geochemical responses to global change.

    Science.gov (United States)

    McCoy, Sophie J; Kamenos, Nicholas A

    2015-02-01

    Coralline algae are globally distributed benthic primary producers that secrete calcium carbonate skeletons. In the context of ocean acidification, they have received much recent attention due to the potential vulnerability of their high-Mg calcite skeletons and their many important ecological roles. Herein, we summarize what is known about coralline algal ecology and physiology, providing context to understand their responses to global climate change. We review the impacts of these changes, including ocean acidification, rising temperatures, and pollution, on coralline algal growth and calcification. We also assess the ongoing use of coralline algae as marine climate proxies via calibration of skeletal morphology and geochemistry to environmental conditions. Finally, we indicate critical gaps in our understanding of coralline algal calcification and physiology and highlight key areas for future research. These include analytical areas that recently have become more accessible, such as resolving phylogenetic relationships at all taxonomic ranks, elucidating the genes regulating algal photosynthesis and calcification, and calibrating skeletal geochemical metrics, as well as research directions that are broadly applicable to global change ecology, such as the importance of community-scale and long-term experiments in stress response.

  14. An integrated approach for evaluating coastal vulnerability in a changing climate

    OpenAIRE

    Harris, Erica; Allan, Jonathan; Ruggiero, Peter

    2010-01-01

    Coastal hazards such as flooding and erosion threaten many coastal communities and ecosystems. With documented increases in both storm frequency and intensity and projected acceleration of sea level rise, incorporating the impacts of climate change and variability into coastal vulnerability assessments is becoming a necessary, yet challenging task. We are developing an integrated approach to probabilistically incorporate the impacts of climate change into coastal vulnerability ass...

  15. An Integrated 3S and Historical Materials Analysis of the Keriya Paleoriver, NW China

    Science.gov (United States)

    Luo, Lei; Wang, Xinyuan; Cai, Heng

    2014-03-01

    Combining analysis of 3S (RS, GIS and GPS) and historical materials (historical records, ancient map and academic and literary writings) allows mapping of the Keriya Paleoriver of Southern Xinjiang, NW China. Keriya Paleoriver, one of the ancient Four Green Corridors which passes through the Taklimakan Desert from south to north in the Tarim Basin, recorded changes of the climate-environment in the ancient Silk Road of the region. According to the archaeological data, historical materials and paleoclimates information, its eco-environment and climate have had great changes since the 1.09Ma B.P., especially during the last 2,000 years, which has led to many famous ancient cities to be abandoned and the route of the ancient Silk Road to be moved southward. Using RS (optical and radar imagery), GIS (mapping and spatial analysis) and GPS (study area investigation), we mapped a major paleodrainage system of Keriya River, which have linked the Kunlun Mountains to the Tienshan Mountains through the Taklimakan Desert, possibly as far back as the early Pleistocene. This study illustrates the capability of the 3S and historical materials, in mapping the Keriya Paleoriver drainage networks and archaeological study on the ancient Silk Road.

  16. Integrated trend assessment of ecosystem changes in the Limfjord (Denmark): evidence of a recent regime shift?

    DEFF Research Database (Denmark)

    Tomczak, Maciej Tomasz; Dinesen, Grete E.; Hoffmann, Erik

    2012-01-01

    An integrated ecosystem assessment was carried out for the Limfjord over the period from 1984 to 2008 to describe changes in ecosystem structure and potentially important drivers. The Limfjord is an eutrophic transitional Danish fjord system with the main inflow from the North Sea in the west...

  17. Price effects of changing quantities supplied at the integrated european fish market

    DEFF Research Database (Denmark)

    Nielsen, Max; Smit, Jos; Guillen, Jordi

    2012-01-01

    This article analyses the effect that changes in the quantities supplied from EU fish stocks have on fish prices. As opposed to earlier studies, this one is European- wide, taking international market integration into account. Average own-price flexibilities for fresh captured fish are found...

  18. Integrating ecosystem services and climate change responses in coastal wetlands development plans for Bangladesh

    NARCIS (Netherlands)

    Sarwar, M.H.; Hein, L.G.; Rip, F.I.; Dearing, J.A.

    2015-01-01

    This study explores the integration of ecosystem services and climate change adaptation in development plans for coastal wetlands in Bangladesh. A new response framework for adaptation is proposed, based on an empirical analysis and consultations with stakeholders, using a modified version of the DP

  19. Crop modelling for integrated assessment of risk to food production from climate change

    DEFF Research Database (Denmark)

    Ewert, F.; Rötter, R.P.; Bindi, M.;

    2015-01-01

    The complexity of risks posed by climate change and possible adaptations for crop production has called for integrated assessment and modelling (IAM) approaches linking biophysical and economic models. This paper attempts to provide an overview of the present state of crop modelling to assess cli...

  20. Associative and Propositional Processes in Evaluation: An Integrative Review of Implicit and Explicit Attitude Change

    Science.gov (United States)

    Gawronski, Bertram; Bodenhausen, Galen V.

    2006-01-01

    A central theme in recent research on attitudes is the distinction between deliberate, "explicit" attitudes and automatic, "implicit" attitudes. The present article provides an integrative review of the available evidence on implicit and explicit attitude change that is guided by a distinction between associative and propositional processes.…

  1. Development of a prototype thermoelectric space cooling system using phase change material to improve the performance

    Science.gov (United States)

    Zhao, Dongliang

    The thermoelectric cooling system has advantages over conventional vapor compression cooling devices, including compact in size, light in weight, high reliability, no mechanical moving parts, no refrigerant, being powered by direct current, and easily switching between cooling and heating modes. However, it has been long suffering from its relatively high cost and low energy efficiency, which has restricted its usage to niche applications, such as space missions, portable cooling devices, scientific and medical equipment, where coefficient of performance (COP) is not as important as reliability, energy availability, and quiet operation environment. Enhancement of thermoelectric cooling system performance generally relies on two methods: improving thermoelectric material efficiency and through thermoelectric cooling system thermal design. This research has been focused on the latter one. A prototype thermoelectric cooling system integrated with phase change material (PCM) thermal energy storage unit for space cooling has been developed. The PCM thermal storage unit used for cold storage at night, functions as the thermoelectric cooling system's heat sink during daytime's cooling period and provides relatively lower hot side temperature for the thermoelectric cooling system. The experimental test of the prototype system in a reduced-scale chamber has realized an average cooling COP of 0.87, with the maximum value of 1.22. Another comparison test for efficacy of PCM thermal storage unit shows that 35.3% electrical energy has been saved from using PCM for the thermoelectric cooling system. In general, PCM faces difficulty of poor thermal conductivity at both solid and liquid phases. This system implemented a finned inner tube to increase heat transfer during PCM charging (melting) process that directly impacts thermoelectric system's performance. A simulation tool for the entire system has been developed including mathematical models for a single thermoelectric module

  2. The Integration of Energy Efficiency, Renewable Energy, DemandResponse and Climate Change: Challenges and Opportunities for Evaluatorsand Planners

    Energy Technology Data Exchange (ETDEWEB)

    Vine, Edward

    2007-05-29

    This paper explores the feasibility of integrating energyefficiency program evaluation with the emerging need for the evaluationof programs from different "energy cultures" (demand response, renewableenergy, and climate change). The paper reviews key features andinformation needs of the energy cultures and critically reviews theopportunities and challenges associated with integrating these withenergy efficiency program evaluation. There is a need to integrate thedifferent policy arenas where energy efficiency, demand response, andclimate change programs are developed, and there are positive signs thatthis integration is starting to occur.

  3. Can integrative catchment management mitigate future water quality issues caused by climate change and socio-economic development?

    Science.gov (United States)

    Honti, Mark; Schuwirth, Nele; Rieckermann, Jörg; Stamm, Christian

    2017-03-01

    The design and evaluation of solutions for integrated surface water quality management requires an integrated modelling approach. Integrated models have to be comprehensive enough to cover the aspects relevant for management decisions, allowing for mapping of larger-scale processes such as climate change to the regional and local contexts. Besides this, models have to be sufficiently simple and fast to apply proper methods of uncertainty analysis, covering model structure deficits and error propagation through the chain of sub-models. Here, we present a new integrated catchment model satisfying both conditions. The conceptual iWaQa model was developed to support the integrated management of small streams. It can be used to predict traditional water quality parameters, such as nutrients and a wide set of organic micropollutants (plant and material protection products), by considering all major pollutant pathways in urban and agricultural environments. Due to its simplicity, the model allows for a full, propagative analysis of predictive uncertainty, including certain structural and input errors. The usefulness of the model is demonstrated by predicting future surface water quality in a small catchment with mixed land use in the Swiss Plateau. We consider climate change, population growth or decline, socio-economic development, and the implementation of management strategies to tackle urban and agricultural point and non-point sources of pollution. Our results indicate that input and model structure uncertainties are the most influential factors for certain water quality parameters. In these cases model uncertainty is already high for present conditions. Nevertheless, accounting for today's uncertainty makes management fairly robust to the foreseen range of potential changes in the next decades. The assessment of total predictive uncertainty allows for selecting management strategies that show small sensitivity to poorly known boundary conditions. The identification

  4. Effects of the Integrated Online Advance Organizer Teaching Materials on Students' Science Achievement and Attitude

    Science.gov (United States)

    Korur, Fikret; Toker, Sacip; Eryılmaz, Ali

    2016-08-01

    This two-group quasi-experimental study investigated the effects of the Online Advance Organizer Concept Teaching Material (ONACOM) integrated with inquiry teaching and expository teaching methods. Grade 7 students' posttest performances on the light unit achievement and light unit attitude tests controlled for gender, previous semester science grade, and pretest scores were analyzed. No significant treatment effects were found between the inquiry and expository approaches. However, both groups demonstrated significant pretest-posttest gains in achievement and attitude. Independent from the method used, ONACOM was judged effective in both groups as students demonstrated increased achievement and attitude scores. ONACOM has a social and semantic network-aided infrastructure that can be adapted to both methods to increase students' achievement and improve their attitude.

  5. On the role of solidification modelling in Integrated Computational Materials Engineering “ICME”

    Science.gov (United States)

    Schmitz, G. J.; Böttger, B.; Apel, M.

    2016-03-01

    Solidification during casting processes marks the starting point of the history of almost any component or product. Integrated Computational Materials Engineering (ICME) [1-4] recognizes the importance of further tracking the history of microstructure evolution along the subsequent process chain. Solidification during joining processes in general happens quite late during production, where the parts to be joined already have experienced a number of processing steps which affected their microstructure. Reliable modelling of melting and dissolution of these microstructures represents a key issue before eventually modelling ‘re’-solidification e.g. during welding or soldering. Some instructive examples of microstructure evolution during a joining process obtained on the basis of synthetic and simulated initial microstructures of an Al-Cu binary model system are discussed.

  6. Integrated safety management as a starting point for working environmental changes

    DEFF Research Database (Denmark)

    Pedersen, Louise Møller; Nielsen, Kent

    2013-01-01

    Organizations: The effective management of organizational change involves understanding and appreciating the complex interactions of technology, people, organizations, economical factors, legislation, and aspects of cultural, physical, and psychological context. The behavior based and culture based...... approach to safety management (DeJoy, 2005) based on a combination of a behavior-based ‘problem-solving process’ and a ‘culture change process’. The participatory problem-solving process and the culture change process require involvement and commitment from management and workers. The ‘problem...... approaches to safety are two seemingly incompatible approaches to creating organizational change in safety performance. However, combined, the two approaches may provide a new perspective on conducting effective and healthy organizational changes. Approach to change: DeJoy has proposed an integrative...

  7. Organizational change for services integration in public human service organizations: experiences in seven counties.

    Science.gov (United States)

    Packard, Thomas; Patti, Rino; Daly, Donna; Tucker-Tatlow, Jennifer

    2012-01-01

    This is a study of organizational change strategies employed in seven county human service agencies to improve the coordination of services through the structural integration of previously free standing organizations or the development of voluntary interagency collaborative service delivery systems. The central question involves the identification of organizational change tactics which contributed to the success of the organizational change initiatives. The literature on organizational change is reviewed, with particular attention to a framework developed by Fernandez and Rainey based on their extensive review and synthesis of the research on successful change strategies in the public and business sectors. Qualitative and quantitative data were gathered from over 250 individuals and from agency documents. Findings are compared with the success factors identified by Fernandez and Rainey, and refinements to their propositions are suggested. More precise methods for measuring successful and unsuccessful change initiatives are suggested. Implications for practice and research are presented.

  8. Integrated effects of air pollution and climate change on forests: a northern hemisphere perspective.

    Science.gov (United States)

    Bytnerowicz, Andrzej; Omasa, Kenji; Paoletti, Elena

    2007-06-01

    Many air pollutants and greenhouse gases have common sources, contribute to radiative balance, interact in the atmosphere, and affect ecosystems. The impacts on forest ecosystems have been traditionally treated separately for air pollution and climate change. However, the combined effects may significantly differ from a sum of separate effects. We review the links between air pollution and climate change and their interactive effects on northern hemisphere forests. A simultaneous addressing of the air pollution and climate change effects on forests may result in more effective research, management and monitoring as well as better integration of local, national and global environmental policies.

  9. Study on polyethylene glycol/epoxy resin composite as a form-stable phase change material

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Yutang; Kang, Huiying; Wang, Weilong; Liu, Hong; Gao, Xuenong [The Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education, South China University of Technology, Guangzhou 510640 (China)

    2010-12-15

    Form-stable polyethylene glycol (PEG)/epoxy resin (EP) composite as a novel phase change material (PCM) was prepared using casting molding method. In this new material, PEG acts as the latent heat storage material and EP polymer serves as the supporting material, which provides structural strength and prevents the leakage of the melted PEG. The structure and morphology of the novel composite were observed using Fourier transformation infrared spectroscope (FTIR) and scanning electronic microscope (SEM). The thermo-mechanical property and transition behavior were characterized by polarizing optical microscope (POM), static thermo-mechanical analysis (TMA) and differential scanning calorimeter (DSC). The experimental results show that, as a result of the physical tangled function of the epoxy resin carrier to the PEG segment, the composite macroscopically presents the solid-solid phase change characteristic. (author)

  10. Study on polyethylene glycol/epoxy resin composite as a form-stable phase change material

    Energy Technology Data Exchange (ETDEWEB)

    Fang Yutang, E-mail: ppytfang@scut.edu.c [Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education, South China University of Technology, Guangzhou 510640 (China); Kang Huiying; Wang Weilong; Liu Hong; Gao Xuenong [Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education, South China University of Technology, Guangzhou 510640 (China)

    2010-12-15

    Form-stable polyethylene glycol (PEG)/epoxy resin (EP) composite as a novel phase change material (PCM) was prepared using casting molding method. In this new material, PEG acts as the latent heat storage material and EP polymer serves as the supporting material, which provides structural strength and prevents the leakage of the melted PEG. The structure and morphology of the novel composite were observed using Fourier transformation infrared spectroscope (FTIR) and scanning electronic microscope (SEM). The thermo-mechanical property and transition behavior were characterized by polarizing optical microscope (POM), static thermo-mechanical analysis (TMA) and differential scanning calorimeter (DSC). The experimental results show that, as a result of the physical tangled function of the epoxy resin carrier to the PEG segment, the composite macroscopically presents the solid-solid phase change characteristic.

  11. Characterization of a lime-pozzolan plaster containing phase change material

    Energy Technology Data Exchange (ETDEWEB)

    Pavlíková, Milena; Pavlík, Zbyšek; Trník, Anton; Pokorný, Jaroslav; Černý, Robert [Department of Materials Engineering and Chemistry, Faculty of Civil Engineering, Czech Technical University in Prague, Thákurova 7, 166 29 Prague (Czech Republic)

    2015-03-10

    A PCM (Phase Change Material) modified lime-pozzolan plaster for improvement of thermal energy storage of building envelopes is studied in the paper. The investigated plaster is composed of lime hydrate, pozzolan admixture based on metakaolin and mudstone, silica sand, water and paraffin wax encapsulated in polymer capsule. The reference plaster without PCM application is studied as well. The analyzed materials are characterized by bulk density, matrix density, total open porosity, compressive strength and pore size distribution. The temperature of phase change, heat of fusion and crystallization are studied using DSC (Difference Scanning Calorimetry) analysis performed in air atmosphere. In order to get information on materials hygrothermal performance, determination of thermal and hygric properties is done in laboratory conditions. Experimental data reveal a substantial improvement of heat storage capacity of PCM-modified plaster as compared to the reference material without PCM.

  12. Changes in the Optical Properties of Materials Are Observed After 18 Months in Low Earth Orbit

    Science.gov (United States)

    Jaworske, Donald A.

    1999-01-01

    Materials located on the exterior of spacecraft in low Earth orbit are subjected to a number of environmental threats, including atomic oxygen, ultraviolet radiation, thermal cycling, and micrometeroid and debris impact. Atomic oxygen attacks materials vulnerable to oxidation. Ultraviolet radiation can break chemical bonds and cause undesirable changes in optical properties. Thermal cycling can cause cracking, and micrometeroid and debris impacts can damage protective coatings. Another threat is contamination. The outgassing of volatile chemicals can contaminate nearby surfaces, changing their thermal control properties. Contaminated surfaces may undergo further change as a result of atomic oxygen and ultraviolet radiation exposure. The Passive Optical Sample Assembly (POSA) experiment was designed as a risk mitigation experiment for the International Space Station. Samples were characterized before launch, exposed for 18 months on the exterior of Mir, and characterized upon their return. Lessons learned from POSA about the durability of material properties can be applied to the space station and other long-duration missions.

  13. Structural integrity of frontostriatal connections predicts longitudinal changes in self-esteem.

    Science.gov (United States)

    Chavez, Robert S; Heatherton, Todd F

    2017-06-01

    Diverse neurological and psychiatric conditions are marked by a diminished sense of positive self-regard, and reductions in self-esteem are associated with risk for these disorders. Recent evidence has shown that the connectivity of frontostriatal circuitry reflects individual differences in self-esteem. However, it remains an open question as to whether the integrity of these connections can predict self-esteem changes over larger timescales. Using diffusion magnetic resonance imaging and probabilistic tractography, we demonstrate that the integrity of white matter pathways linking the medial prefrontal cortex to the ventral striatum predicts changes in self-esteem 8 months after initial scanning in a sample of 30 young adults. Individuals with greater integrity of this pathway during the scanning session at Time 1 showed increased levels of self-esteem at follow-up, whereas individuals with lower integrity showed stifled or decreased levels of self-esteem. These results provide evidence that frontostriatal white matter integrity predicts the trajectory of self-esteem development in early adulthood, which may contribute to blunted levels of positive self-regard seen in multiple psychiatric conditions, including depression and anxiety.

  14. Thermal Analysis for Monitoring Effects of Shock-Induced Physical, Mechanical, and Chemical Changes in Materials

    Science.gov (United States)

    2015-01-19

    chemical reactions as a function of temperature. Since the DSC is at constant pressure, heat flow measured is equivalent to enthalpy changes: Here...mechanical activation; reactive materials; anaerobic reactions REPORT DOCUMENTATION PAGE 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 10. SPONSOR/MONITOR’S...be of benefit to our other DoD supported work on understanding of shock-activation leading to reactions in energetic/reactive materials. The thermal

  15. Simulated Aging and Characterization of Phase Change Materials for Thermal Management of Building Envelopes

    Science.gov (United States)

    2015-09-01

    Method B). West Conshohocken, PA: ASTM International. ———. 2009. Standard Method for Surface Burning Characteristics of Building Materials. ASTM E84-09...storage in buildings : A state of art. Renewable and Sustainable Energy Reviews 11(6):1146-1166 Yu, S., S. Jeong, C. Chyoung, and S. Kim. 2014. Bio-based...Simulated Aging and Characterization of Phase Change Materials for lhermal Management of Building Envelopes Elizabeth J. Gao, Jignesh Patel, Veera M. Boddu

  16. Energy Storage Properties of Phase Change Materials Prepared from PEG/CPP

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    New kinds of solid-solid phase change materials have been prepared in our laboratory.In these materials, the rigid polymer chlorinated polypropylene is taken as skeletons and the flexible polymer polyethylene glycol 6000 and polyethylene glycol 10000 are taken as functional chains. Results show that chlorinated polypropylene grafted by polyethylene glycol 10000 has greater enthalpy than chlorinated polypropylene grafted by polyethylene glycol 6000.

  17. An integrated spatial snap-shot monitoring method for identifying seasonal changes and spatial changes in surface water quality

    Science.gov (United States)

    Chittoor Viswanathan, Vidhya; Jiang, Yongjun; Berg, Michael; Hunkeler, Daniel; Schirmer, Mario

    2016-08-01

    Integrated catchment-scale management approaches in large catchments are often hindered due to the poor understanding of the spatially and seasonally variable pathways of pollutants. High-frequency monitoring of water quality at random locations in a catchment is resource intensive and challenging. A simplified catchment-scale monitoring approach is developed in this study, for the preliminary identification of water quality changes - Integrated spatial snap-shot monitoring (ISSM). This multi-parameter monitoring approach is applied using the isotopes of water (δ18O-H2O and δD) and nitrate (δ15N-NO3- and δ18O-NO3-) together with the fluxes of nitrate and other solutes, which are used as chemical markers. This method involves selection of few sampling stations, which are identified as the hotspots of water quality changes within the catchment. The study was conducted in the peri-alpine Thur catchment in Switzerland, with two snap-shot campaigns (representative of two widely varying hydrological conditions), in summer 2012 (low flow) and spring 2013 (high flow). Significant spatial (varying with elevation) and seasonal changes in the sources of water were observed between the two seasons. A spatial variation of the sources of nitrate and the solute loads was observed, in tandem with the land use changes in the Thur catchment. There is a seasonal shift in the sources of nitrate, it varies from a strong treated waste water signature during the low flow season to a mixture of other sources (like soil nitrogen derived from agriculture), in the high flow season. This demonstrates the influence of other sources that override the influence of waste water treatment plants (WWTPs) during high flow in the Thur River and its tributaries. This method is expected to be a cost-effective alternative, providing snap-shots, that can help in the preliminary identification of the pathways of solutes and their seasonal/spatial changes in catchments.

  18. The integration of facial and vocal cues during emotional change perception: EEG markers.

    Science.gov (United States)

    Chen, Xuhai; Pan, Zhihui; Wang, Ping; Yang, Xiaohong; Liu, Peng; You, Xuqun; Yuan, Jiajin

    2016-07-01

    The ability to detect emotional changes is of primary importance for social living. Though emotional signals are often conveyed by multiple modalities, how emotional changes in vocal and facial modalities integrate into a unified percept has yet to be directly investigated. To address this issue, we asked participants to detect emotional changes delivered by facial, vocal and facial-vocal expressions while behavioral responses and electroencephalogram were recorded. Behavioral results showed that bimodal emotional changes were detected with higher accuracy and shorter response latencies compared with each unimodal condition. Moreover, the detection of emotional change, regardless of modalities, was associated with enhanced amplitudes in the N2 and P3 component, as well as greater theta synchronization. More importantly, the P3 amplitudes and theta synchronization were larger for the bimodal emotional change condition than for the sum of the two unimodal conditions. The superadditive responses in P3 amplitudes and theta synchronization were both positively correlated with the magnitude of the bimodal superadditivity in accuracy. These behavioral and electrophysiological data consistently illustrated an effect of audiovisual integration during the detection of emotional changes, which is most likely mediated by the P3 activity and theta oscillations in brain responses.

  19. Modeling Sea-Level Change using Errors-in-Variables Integrated Gaussian Processes

    Science.gov (United States)

    Cahill, Niamh; Parnell, Andrew; Kemp, Andrew; Horton, Benjamin

    2014-05-01

    We perform Bayesian inference on historical and late Holocene (last 2000 years) rates of sea-level change. The data that form the input to our model are tide-gauge measurements and proxy reconstructions from cores of coastal sediment. To accurately estimate rates of sea-level change and reliably compare tide-gauge compilations with proxy reconstructions it is necessary to account for the uncertainties that characterize each dataset. Many previous studies used simple linear regression models (most commonly polynomial regression) resulting in overly precise rate estimates. The model we propose uses an integrated Gaussian process approach, where a Gaussian process prior is placed on the rate of sea-level change and the data itself is modeled as the integral of this rate process. The non-parametric Gaussian process model is known to be well suited to modeling time series data. The advantage of using an integrated Gaussian process is that it allows for the direct estimation of the derivative of a one dimensional curve. The derivative at a particular time point will be representative of the rate of sea level change at that time point. The tide gauge and proxy data are complicated by multiple sources of uncertainty, some of which arise as part of the data collection exercise. Most notably, the proxy reconstructions include temporal uncertainty from dating of the sediment core using techniques such as radiocarbon. As a result of this, the integrated Gaussian process model is set in an errors-in-variables (EIV) framework so as to take account of this temporal uncertainty. The data must be corrected for land-level change known as glacio-isostatic adjustment (GIA) as it is important to isolate the climate-related sea-level signal. The correction for GIA introduces covariance between individual age and sea level observations into the model. The proposed integrated Gaussian process model allows for the estimation of instantaneous rates of sea-level change and accounts for all

  20. Incorporation of Integral Fuel Burnable Absorbers Boron and Gadolinium into Zirconium-Alloy Fuel Clad Material

    Energy Technology Data Exchange (ETDEWEB)

    Sridharan, K.; Renk, T.J.; Lahoda, E.J.; Corradini, M.L

    2004-12-14

    Long-lived fuels require the use of higher enrichments of 235U or other fissile materials. Such high levels of fissile material lead to excessive fuel activity at the beginning of life. To counteract this excessive activity, integral fuel burnable absorbers (IFBA) are added to some rods in the fuel assembly. The two commonly used IFBA elements are gadolinium, which is added as gadolinium-oxide to the UO2 powder, and boron, which is applied as a zirconium-diboride coating on the UO2 pellets using plasma spraying or chemical vapor deposition techniques. The incorporation of IFBA into the fuel has to be performed in a nuclear-regulated facility that is physically separated from the main plant. These operations tend to be very costly because of their small volume and can add from 20 to 30% to the manufacturing cost of the fuel. Other manufacturing issues that impact cost and performance are maintaining the correct levels of dosing, the reduction in fuel melting point due to gadolinium-oxide additions, and parasitic neutron absorption at fuel's end-of-life. The goal of the proposed research is to develop an alternative approach that involves incorporation of boron or gadolinium into the outer surface of the fuel cladding material rather than as an additive to the fuel pellets. This paradigm shift will allow for the introduction of the IFBA in a non-nuclear regulated environment and will obviate the necessity of additional handling and processing of the fuel pellets. This could represent significant cost savings and potentially lead to greater reproducibility and control of the burnable fuel in the early stages of the reactor operation. The surface alloying is being performed using the IBEST (Ion Beam Surface Treatment) process developed at Sandia National Laboratories. IBEST involves the delivery of energetic ion beam pulses onto the surface of a material, near-surface melting, and rapid solidification. The non-equilibrium nature of such processing allows for

  1. Effect of Different Denture Base Materials and Changed Mouth Temperature on Dimensional Stability of Complete Dentures

    Directory of Open Access Journals (Sweden)

    Khalid A. O. Arafa

    2016-01-01

    Full Text Available Background. Type of materials used in fabrication of denture base has an effect on dimension during denture base material processing and other factors related to clinical use. Objective. The study aims were to assess the dimensional stability including thermal changes of three different denture base materials. Methods. Ninety patients were selected to construct complete dentures with different denture base materials. They were randomly divided into three groups: group 1, patients with cobalt chrome metallic base; group 2, patients with heat curing acrylic resin fabricated by injection moulding technique; and group 3, patients with denture bases fabricated by conventional heat curing acrylic resin. The dimensional changes were assessed using digital caliper. Results. After the twelfth month, injection moulding acrylic resin had significantly the highest dimensional change followed by the conventional heat curing acrylic resin. There were no significant differences in the dimensions between the three types of denture base materials at normal mouth temperature, while, after hot tea drinking at 45°C, the dimensional change was significantly the highest in cobalt chrome metallic denture base group. Conclusion. Cobalt chrome metallic denture base has stable dimension compared to denture bases fabricated of acrylic resin but it was more affected by altered mouth temperature. The study was registered in the International Standard Randomized Controlled Trials Number (ISRCTN registry with study ID (ISRCTN94238244.

  2. Development of phase change materials based microencapsulated technology for buildings: A review

    Energy Technology Data Exchange (ETDEWEB)

    Tyagi, V.V.; Kaushik, S.C. [Centre for Energy Studies, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016 (India); Tyagi, S.K. [School of Infrastructure Technology and Resource Management, Shri Mata Vaishno Devi University, Katra 182320, J and K (India); Akiyama, T. [Center for Advanced Research of Energy Conversion Materials, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Sapporo 060-86283 (Japan)

    2011-02-15

    Thermal energy storage (TES) systems using phase change material (PCM) have been recognized as one of the most advanced energy technologies in enhancing the energy efficiency and sustainability of buildings. Now the research is focus on suitable method to incorporate PCMs with building. There are several methods to use phase change materials (PCMs) in thermal energy storage (TES) for different applications. Microencapsulation is one of the well known and advanced technologies for better utilization of PCMs with building parts, such as, wall, roof and floor besides, within the building materials. Phase change materials based microencapsulation for latent heat thermal storage (LHTS) systems for building application offers a challenging option to be employed as effective thermal energy storage and a retrieval device. Since the particular interest in using microencapsulation PCMs for concrete and wall/wallboards, the specific research efforts on both subjects are reviewed separately. This paper presents an overview of the previous research work on microencapsulation technology for thermal energy storage incorporating the phase change materials (PCMs) in the building applications, along with few useful conclusive remarks concluded from the available literature. (author)

  3. An integrated material metabolism model for stocks of urban road system in Beijing, China.

    Science.gov (United States)

    Guo, Zhen; Hu, Dan; Zhang, Fuhua; Huang, Guolong; Xiao, Qiang

    2014-02-01

    Rapid urbanization has greatly altered the urban metabolism of material and energy. As a significant part of the infrastructure, urban roads are being rapidly developed worldwide. Quantitative analysis of metabolic processes on urban road systems, especially the scale, composition and spatial distribution of their stocks, could help to assess the resource appropriation and potential environmental impacts, as well as improve urban metabolism models. In this paper, an integrated model, which covered all types of roads, intersection structures and ancillary facilities, was built for calculating the material stocks of urban road systems. Based on a bottom-up method, the total stocks were disassembled into a number of stock parts rather than obtained by input-output data, which provided an approach promoting data availability and inner structure understanding. The combination with GIS enabled the model to tackle the complex structures of road networks and avoid double counting. In the case study of Beijing, the following results are shown: 1) The total stocks for the entire road system reached 159 million tons, of which nearly 80% was stored in roads, and 20% in ancillary facilities. 2) Macadam was the largest stock (111 million tons), while stone mastic asphalt, polyurethane plastics, and atactic polypropylene accounted for smaller components of the overall system. 3) The stock per unit area of pedestrian overcrossing was higher than that of the other stock units in the entire system, and its steel stocks reached 0.49 t/m(2), which was 10 times as high as that in interchanges. 4) The high stock areas were mainly distributed in ring-shaped and radial expressways, as well as in major interchanges. 5) Expressways and arterials were excessively emphasized, while minor roads were relatively ignored. However, the variation of cross-sectional thickness in branches and neighborhood roads will have a significant impact on the scale of material stocks in the entire road system.

  4. Effect of Changing Table Tennis Ball Material from Celluloid to Plastic on the Post-Collision Ball Trajectory

    Directory of Open Access Journals (Sweden)

    Inaba Yuki

    2017-01-01

    Full Text Available The official material used in table tennis balls was changed from celluloid to plastic, a material free of celluloid, in 2014. The purpose of this study was to understand the differences and similarities in the two types of ball materials by comparing their behavior upon collision with a table. The behavior of the balls before and after collision with a table, at various initial speeds ranging from 15 to 115 km/h, was captured using high-speed cameras. Velocities and spin rates before collision and velocities after collision were computed to calculate the coefficients of restitution and friction. Based on the computed variables, the post-collision trajectories of both balls were calculated by integrating the equation of motion of the ball for simulated service, smash and drive conditions with respect to time. The coefficients of restitution were higher for the plastic balls than the celluloid ones when the initial vertical velocities were higher. The coefficients of friction were higher for plastic balls when the initial horizontal contact point velocities were slower. Because of the differences in the material characteristics, the plastic ball trajectories of services with backspin and drives with great topspin were expected to be different from those of celluloid balls. Since the extent of differences between the two ball types varied depending on the initial conditions, testing at various initial conditions was suggested for comparing and understanding the characteristics of the balls.

  5. Embedded binary eutectic alloy nanostructures: a new class of phase change materials.

    Science.gov (United States)

    Shin, S J; Guzman, J; Yuan, C-W; Liao, Christopher Y; Boswell-Koller, Cosima N; Stone, P R; Dubon, O D; Minor, A M; Watanabe, Masashi; Beeman, Jeffrey W; Yu, K M; Ager, J W; Chrzan, D C; Haller, E E

    2010-08-11

    Phase change materials are essential to a number of technologies ranging from optical data storage to energy storage and transport applications. This widespread interest has given rise to a substantial effort to develop bulk phase change materials well suited for desired applications. Here, we suggest a novel and complementary approach, the use of binary eutectic alloy nanoparticles embedded within a matrix. Using GeSn nanoparticles embedded in silica as an example, we establish that the presence of a nanoparticle/matrix interface enables one to stabilize both nanobicrystal and homogeneous alloy morphologies. Further, the kinetics of switching between the two morphologies can be tuned simply by altering the composition.

  6. Quantification of the effect of hysteresis on the adiabatic temperature change in magnetocaloric materials

    DEFF Research Database (Denmark)

    von Moos, Lars; Bahl, Christian R.H.; Nielsen, Kaspar Kirstein

    2014-01-01

    We quantify the effect of hysteresis on the performance of the magnetocaloric first order material Gd5Si2Ge2 undergoing an ideal active magnetic regenerator (AMR) cycle. The material is carefully characterized through magnetometry (VSM) and calorimetry (DSC) in order to enable an accurate model...... description of the phase transition at varying magnetic fields and temperatures. Using detailed experimental property data, a Preisach type model is used to describe the thermal hysteresis effects and simulate the material under realistic working conditions. We find that the adiabatic temperature change...... is limited by a significant fraction of the thermal hysteresis....

  7. Integrating human responses to climate change into conservation vulnerability assessments and adaptation planning.

    Science.gov (United States)

    Maxwell, Sean L; Venter, Oscar; Jones, Kendall R; Watson, James E M

    2015-10-01

    The impact of climate change on biodiversity is now evident, with the direct impacts of changing temperature and rainfall patterns and increases in the magnitude and frequency of extreme events on species distribution, populations, and overall ecosystem function being increasingly publicized. Changes in the climate system are also affecting human communities, and a range of human responses across terrestrial and marine realms have been witnessed, including altered agricultural activities, shifting fishing efforts, and human migration. Failing to account for the human responses to climate change is likely to compromise climate-smart conservation efforts. Here, we use a well-established conservation planning framework to show how integrating human responses to climate change into both species- and site-based vulnerability assessments and adaptation plans is possible. By explicitly taking into account human responses, conservation practitioners will improve their evaluation of species and ecosystem vulnerability, and will be better able to deliver win-wins for human- and biodiversity-focused climate adaptation.

  8. Penn gap rule in phase-change memory materials: No clear evidence for resonance bonds

    Science.gov (United States)

    Shimakawa, K.; Střižik, L.; Wagner, T.; Frumar, M.

    2015-04-01

    Although a proposal of resonance bonds in crystalline phase-change materials based on the GeSbTe system has been provided, we do not find any clear evidence in favor of the proposal. The ellipsometric study demonstrates that a change in the high frequency dielectric constant ɛ∞ between the amorphous and crystalline phases is only scaled by the average bandgap (the Penn gap rule). Even for a pure antimony film, regarded as a prototype resonance bonding material, ɛ∞ was found to follow the Penn gap rule. Experimentally, we did not find any evidence of a significant change in the optical transition matrix element during the phase change, which is necessary to support the idea of resonance bonds.

  9. Penn gap rule in phase-change memory materials: No clear evidence for resonance bonds

    Directory of Open Access Journals (Sweden)

    K. Shimakawa

    2015-04-01

    Full Text Available Although a proposal of resonance bonds in crystalline phase-change materials based on the GeSbTe system has been provided, we do not find any clear evidence in favor of the proposal. The ellipsometric study demonstrates that a change in the high frequency dielectric constant ε∞ between the amorphous and crystalline phases is only scaled by the average bandgap (the Penn gap rule. Even for a pure antimony film, regarded as a prototype resonance bonding material, ε∞ was found to follow the Penn gap rule. Experimentally, we did not find any evidence of a significant change in the optical transition matrix element during the phase change, which is necessary to support the idea of resonance bonds.

  10. Modeling Phase Change Material in Micro-Foam Under Constant Temperature Condition (Postprint)

    Science.gov (United States)

    2014-01-01

    capture the phase change process in PCM /micro-foam systems, with the effective thermal conductivity derived from direct simulations and expressed as a...in PCM /micro-foam systems, with the effective thermal conductivity derived from direct simulations and expressed as a power law of porosity. Published...by Elsevier Ltd.1. Introduction Metal or graphite foams [1] filled with phase change materials ( PCM ) are attractive for thermal energy storage (TES

  11. Structured trajectory planning of collision-free lane change using the vehicle-driver integration data

    Institute of Scientific and Technical Information of China (English)

    WANG JiangFeng; ZHANG Qian; ZHANG ZhiQ; YAN XueDong

    2016-01-01

    In this paper,the structured trajectory planning of lane change in collision-free road environment is studied and validated using the vehicle-driver integration data,and a new trajectory planning model for lane change is proposed based on linear offset and sine function to balance driver comfort and vehicle dynamics.The trajectory curvature of the proposed model is continuous without mutation,and the zero-based curvature at the starting and end points during lane change assures the motion direction of end points in parallel with the lane line.The field experiment are designed to collect the vehicle-driver integration data,such as steering angle,brake pedal angel and accelerator pedal angel.The correction Correlation analysis of lane-changing maneuver and influencing variables is conducted to obtain the significant variables that can be used to calibrate and test the proposed model.The results demonstrate that vehicle velocity and Y-axis acceleration have significant effects on the lane-changing maneuver,so that the model recalibrated by the samples of different velocity ranges and Y-axis accelerations has better fitted performance compared with the model calibrated by the sample trajectory.In addition,the proposed model presents a decreasing tendency of the lane change trajectory fitted MAE with the increase of time span of calibrating samples at the starting stage.

  12. Gait changes following myofascial structural integration (Rolfing) observed in 2 children with cerebral palsy.

    Science.gov (United States)

    Hansen, Alexis B; Price, Karen S; Loi, Elizabeth C; Buysse, Christina A; Jaramillo, Theresa M; Pico, Elaine L; Feldman, Heidi M

    2014-10-01

    Children with spastic cerebral palsy experience difficulty with ambulation. Structural changes in muscle and fascia may play a role in abnormal gait. Myofascial structural integration (Rolfing) is a manual therapy that manipulates muscle and soft tissues to loosen fascia layers, reposition muscles, and facilitate alignment. This study aimed to document (1) gait characteristics of 2 children with cerebral palsy and (2) effects of myofascial structural integration on their gait. Children received 3 months of weekly therapy sessions by an experienced practitioner. Gait parameters were recorded at baseline and after treatment using an electronic walkway. Children with cerebral palsy demonstrated abnormal velocity and cadence, decreased step length and single support times, and increased double support time. After treatment, both children demonstrated improvement for 3 months in cadence and double support time. The objective gait analyses demonstrated temporary improvements after myofascial structural integration in children with spastic cerebral palsy.

  13. Integrated ground-based and remotely sensed data to support global studies of environmental change

    Energy Technology Data Exchange (ETDEWEB)

    Olson, R.J.; Turner, R.S.; Garten, C.T.

    1994-09-15

    Data centers routinely archive and distribute large databases of high quality and with rigorous documentation but, to meet the needs of global studies effectively and efficiently, data centers must go beyond these traditional roles. Global studies of environmental change require integrated databases of multiple data types that are accurately coordinated in terms of spatial, temporal and thematic properties. Such datasets must be designed and developed jointly by scientific researchers, computer specialists, and policy analysts. The presentation focuses on our approach for organizing data from ground-based research programs so that the data can be linked with remotely sensed data and other map data into integrated databases with spatial, temporal, and thematic characteristics relevant to global studies. The development of an integrated database for Net Primary Productivity is described to illustrate the process.

  14. Data integration of cost materials needs through a service oriented architecture (study case: pt x garment ungaran)

    OpenAIRE

    Erwien Christianto; Wiranto Utomo; Wiwin Sulistyo

    2015-01-01

    Data processing is an important part of a garment company. With increasingly complex and developing a garment company, data processing and integration became a very important requirement. The need for data integration in determining the cost of materials becomes a very important part in the garment industry. Data distribution or dissemination from one to another section gives results in data duplication, so that it may cause the data to be inconsistent. In addition, the efficiency of the proc...

  15. Description of the M-integral in an elastic plastic material

    Science.gov (United States)

    Tao, Huiyu; Gao, Cheng; Xu, Jinyong; Tang, Yan; Cai, Dayong; Huang, Ranran

    2017-01-01

    By use of finite element analysis method of elastic-plasticity, a calculation of M-integral for 7075 aluminum alloy plate containing different configuration defects was conducted. The effect of plastic energy on path independence of the M-integral is discussed, The variation of M-integral of the holes before and after coalescence under tension loading is studied. Analysis result indicates that M-integral will be path dependent when the plastic zone is passed through by the selected integration contours. There is a jump of the M-integral when coalescence of the holes in a plate occurs. The value of the M-integral is always configuration dependent.

  16. Advanced phase change materials and systems for solar passive heating and cooling of residential buildings

    Energy Technology Data Exchange (ETDEWEB)

    Salyer, I.O.; Sircar, A.K.; Dantiki, S.

    1988-01-01

    During the last three years under the sponsorship of the DOE Solar Passive Division, the University of Dayton Research Institute (UDRI) has investigated four phase change material (PCM) systems for utility in thermal energy storage for solar passive heating and cooling applications. From this research on the basis of cost, performance, containment, and environmental acceptability, we have selected as our current and most promising series of candidate phase change materials, C-15 to C-24 linear crystalline alkyl hydrocarbons. The major part of the research during this contract period was directed toward the following three objectives. Find, test, and develop low-cost effective phase change materials (PCM) that melt and freeze sharply in the comfort temperature range of 73--77{degree}F for use in solar passive heating and cooling of buildings. Define practical materials and processes for fire retarding plasterboard/PCM building products. Develop cost-effective methods for incorporating PCM into building construction materials (concrete, plasterboard, etc.) which will lead to the commercial manufacture and sale of PCM-containing products resulting in significant energy conservation.

  17. Dynamic integration of land use changes in a hydrologic assessment of a rapidly developing Indian catchment.

    Science.gov (United States)

    Wagner, Paul D; Bhallamudi, S Murty; Narasimhan, Balaji; Kantakumar, Lakshmi N; Sudheer, K P; Kumar, Shamita; Schneider, Karl; Fiener, Peter

    2016-01-01

    Rapid land use and land-cover changes strongly affect water resources. Particularly in regions that experience seasonal water scarcity, land use scenario assessments provide a valuable basis for the evaluation of possible future water shortages. The objective of this study is to dynamically integrate land use model projections with a hydrologic model to analyze potential future impacts of land use change on the water resources of a rapidly developing catchment upstream of Pune, India. For the first time projections from the urban growth and land use change model SLEUTH are employed as a dynamic input to the hydrologic model SWAT. By this means, impacts of land use changes on the water balance components are assessed for the near future (2009-2028) employing four different climate conditions (baseline, IPCC A1B, dry, wet). The land use change modeling results in an increase of urban area by +23.1% at the fringes of Pune and by +12.2% in the upper catchment, whereas agricultural land (-14.0% and -0.3%, respectively) and semi-natural area (-9.1% and -11.9%, respectively) decrease between 2009 and 2028. Under baseline climate conditions, these land use changes induce seasonal changes in the water balance components. Water yield particularly increases at the onset of monsoon (up to +11.0mm per month) due to increased impervious area, whereas evapotranspiration decreases in the dry season (up to -15.1mm per month) as a result of the loss of irrigated agricultural area. As the projections are made for the near future (2009-2028) land use change impacts are similar under IPCC A1B climate conditions. Only if more extreme dry years occur, an exacerbation of the land use change impacts can be expected. Particularly in rapidly changing environments an implementation of both dynamic land use change and climate change seems favorable to assess seasonal and gradual changes in the water balance.

  18. The behavior of self-compacting concrete containing micro-encapsulated Phase Change Materials

    NARCIS (Netherlands)

    Hunger, M.; Entrop, A.G.; Mandilaras, I.; Brouwers, H.J.H.; Founti, M.

    2009-01-01

    In order to come to a sustainable built environment the construction industry requires new energy saving concepts. One concept is to use Phase Change Materials (PCM), which have the ability to absorb and to release thermal energy at a specific temperature. This paper presents a set of experiments us

  19. Electromagnetic material changes for remote detection and monitoring: a feasibility study: Progress report

    Energy Technology Data Exchange (ETDEWEB)

    McCloy, John S.; Jordan, David V.; Kelly, James F.; McMakin, Douglas L.; Johnson, Bradley R.; Campbell, Luke W.

    2009-09-01

    A new concept for radiation detection is proposed, allowing a decoupling of the sensing medium and the readout. An electromagnetic material, such as a magnetic ceramic ferrite, is placed near a source to be tracked such as a shipping container. The electromagnetic material changes its properties, in this case its magnetic permeability, as a function of radiation. This change is evident as a change in reflection frequency and magnitude when probed using a microwave/millimeter-wave source. This brief report discusses modeling of radiation interaction of various candidate materials using a radiation detector modeling code Geant4, system design considerations for the remote readout, and some theory of the material interaction physics. The theory of radiation change in doped magnetic insulator ferrites such as yttrium iron garnet (YIG) seems well founded based on literature documentation of the photomagnetic effect. The literature also suggests sensitivity of permittivity to neutrons in some ferroelectrics. Research to date indicates that experimental demonstration of these effects in the context of radiation detection is warranted.

  20. Changes in the role of raw and processed materials in the economic future of industrialized countries

    Energy Technology Data Exchange (ETDEWEB)

    Santoprete, G.

    The author applies commodity science criteria to review the changes which have occured in the use and development of raw and processed materials. He evaluates the role that commodity consumption plays in influencing the economic growth of individual countries and provides an assessment of future global development and marketing trends.

  1. Optimal design variable considerations in the use of phase change materials in indirect evaporative cooling

    Science.gov (United States)

    Chilakapaty, Ankit Paul

    The demand for sustainable, energy efficient and cost effective heating and cooling solutions is exponentially increasing with the rapid advancement of computation and information technology. Use of latent heat storage materials also known as phase change materials (PCMs) for load leveling is an innovative solution to the data center cooling demands. These materials are commercially available in the form of microcapsules dispersed in water, referred to as the microencapsulated phase change slurries and have higher heat capacity than water. The composition and physical properties of phase change slurries play significant role in energy efficiency of the cooling systems designed implementing these PCM slurries. Objective of this project is to study the effect of PCM particle size, shape and volumetric concentration on overall heat transfer potential of the cooling systems designed with PCM slurries as the heat transfer fluid (HTF). In this study uniform volume heat source model is developed for the simulation of heat transfer potential using phase change materials in the form of bulk temperature difference in a fully developed flow through a circular duct. Results indicate the heat transfer potential increases with PCM volumetric concentration with gradually diminishing returns. Also, spherical PCM particles offer greater heat transfer potential when compared to cylindrical particles. Results of this project will aid in efficient design of cooling systems based on PCM slurries.

  2. Non-Toxic, Non-Flammable, -80 C Phase Change Materials

    Science.gov (United States)

    Cutbirth, J. Michael

    2013-01-01

    The objective of this effort was to develop a non-toxic, non-flammable, -80 C phase change material (PCM) to be used in NASA's ICEPAC capsules for biological sample preservation in flight to and from Earth orbit. A temperature of about -68 C or lower is a critical temperature for maintaining stable cell, tissue, and cell fragment storage.

  3. Audiovisual integration in near and far space: effects of changes in distance and stimulus effectiveness.

    Science.gov (United States)

    Van der Stoep, N; Van der Stigchel, S; Nijboer, T C W; Van der Smagt, M J

    2016-05-01

    A factor that is often not considered in multisensory research is the distance from which information is presented. Interestingly, various studies have shown that the distance at which information is presented can modulate the strength of multisensory interactions. In addition, our everyday multisensory experience in near and far space is rather asymmetrical in terms of retinal image size and stimulus intensity. This asymmetry is the result of the relation between the stimulus-observer distance and its retinal image size and intensity: an object that is further away is generally smaller on the retina as compared to the same object when it is presented nearer. Similarly, auditory intensity decreases as the distance from the observer increases. We investigated how each of these factors alone, and their combination, affected audiovisual integration. Unimodal and bimodal stimuli were presented in near and far space, with and without controlling for distance-dependent changes in retinal image size and intensity. Audiovisual integration was enhanced for stimuli that were presented in far space as compared to near space, but only when the stimuli were not corrected for visual angle and intensity. The same decrease in intensity and retinal size in near space did not enhance audiovisual integration, indicating that these results cannot be explained by changes in stimulus efficacy or an increase in distance alone, but rather by an interaction between these factors. The results are discussed in the context of multisensory experience and spatial uncertainty, and underline the importance of studying multisensory integration in the depth space.

  4. Water governance, resilience and global environmental change - a reassessment of integrated water resources management (IWRM).

    Science.gov (United States)

    Galaz, V

    2007-01-01

    Integrated Water Resource Management (IWRM) is gaining increased acceptance among water policy makers and researchers as a way to create more effective governance institutions, leading towards integrated water development solutions for poverty alleviation, while addressing social, economic and environmental aspects of water challenges. However, global environmental change poses fundamental challenges to water policy makers as it implies vast scientific, and hence, policy uncertainty; its implications for international water governance initiatives remain unspecified, effectively hindering dialogue on how current IWRM initiatives should be modified. This paper addresses the lag between our growing understanding of resilient interconnected freshwater resources (and their governance) and the reforms being promoted by policy makers. In particular, there is a need to rethink some of IWRM's key components to better tackle the challenges posed by the complex behaviour of interconnected social-ecological systems and global environmental change.

  5. A MATHEMATICAL MODEL OF OPTIMIZATION OF THE VOLUME OF MATERIAL FLOWS IN GRAIN PROCESSING INTEGRATED PRODUCTION SYSTEMS

    Directory of Open Access Journals (Sweden)

    Baranovskaya T. P.

    2014-06-01

    Full Text Available The article suggests a mathematical model of optimization of the volume of material flows: the model for the ideal conditions; the model for the working conditions; generalized model of determining the optimal input parameters. These models optimize such parameters of inventory management in technology-integrated grain production systems, as the number of cycles supply, the volume of the source material and financial flows. The study was carried out on the example of the integrated system of production, processing and sales of wheat (bread with the full technological cycle

  6. On entropy change measurements around first order phase transitions in caloric materials

    Science.gov (United States)

    Caron, Luana; Doan, Nguyen Ba; Ranno, Laurent

    2017-02-01

    In this work we discuss the measurement protocols for indirect determination of the isothermal entropy change associated with first order phase transitions in caloric materials. The magneto-structural phase transitions giving rise to giant magnetocaloric effects in Cu-doped MnAs and FeRh are used as case studies to exemplify how badly designed protocols may affect isothermal measurements and lead to incorrect entropy change estimations. Isothermal measurement protocols which allow correct assessment of the entropy change around first order phase transitions in both direct and inverse cases are presented.

  7. Integration and Typologies of Vulnerability to Climate Change: A Case Study from Australian Wheat Sheep Zones

    Science.gov (United States)

    Huai, Jianjun

    2016-09-01

    Although the integrated indicator methods have become popular for assessing vulnerability to climate change, their proliferation has introduced a confusing array of scales and indicators that cause a science-policy gap. I argue for a clear adaptation pathway in an “integrative typology” of regional vulnerability that matches appropriate scales, optimal measurements and adaptive strategies in a six-dimensional and multi-level analysis framework of integration and typology inspired by the “5W1H” questions: “Who is concerned about how to adapt to the vulnerability of what to what in some place (where) at some time (when)?” Using the case of the vulnerability of wheat, barley and oats to drought in Australian wheat sheep zones during 1978–1999, I answer the “5W1H” questions through establishing the “six typologies” framework. I then optimize the measurement of vulnerability through contrasting twelve kinds of vulnerability scores with the divergence of crops yields from their regional mean. Through identifying the socioeconomic constraints, I propose seven generic types of crop-drought vulnerability and local adaptive strategy. Our results illustrate that the process of assessing vulnerability and selecting adaptations can be enhanced using a combination of integration, optimization and typology, which emphasize dynamic transitions and transformations between integration and typology.

  8. An integrative mechanistic account of psychological distress, therapeutic change and recovery: the Perceptual Control Theory approach.

    Science.gov (United States)

    Higginson, Sally; Mansell, Warren; Wood, Alex M

    2011-03-01

    The exact nature and mechanisms of psychological change within psychological disorders remain unknown. This review aims to use a psychological framework known as Perceptual Control Theory (Powers, 1973, 2005; Powers, Clark, & McFarland, 1960) to integrate the diverse literature within psychotherapy research. The core principles of Perceptual Control Theory are explained, and key domains of psychotherapy are considered to explore how well they converge with these principles. The quantitative and qualitative empirical literature on the process of psychological change is reviewed to examine how it fits with predictions based on Perceptual Control Theory. Furthermore, the prerequisites for psychological change; client qualities, therapist qualities, the therapeutic alliance and the shifting of awareness, are also considered to examine their consistency within a Perceptual Control Theory account. Finally the strengths and limitations of a Perceptual Control Theory account in explaining the mechanism of psychological change are considered.

  9. Dynamic changes in protein functional linkage networks revealed by integration with gene expression data.

    Directory of Open Access Journals (Sweden)

    Shubhada R Hegde

    2008-11-01

    Full Text Available Response of cells to changing environmental conditions is governed by the dynamics of intricate biomolecular interactions. It may be reasonable to assume, proteins being the dominant macromolecules that carry out routine cellular functions, that understanding the dynamics of protein:protein interactions might yield useful insights into the cellular responses. The large-scale protein interaction data sets are, however, unable to capture the changes in the profile of protein:protein interactions. In order to understand how these interactions change dynamically, we have constructed conditional protein linkages for Escherichia coli by integrating functional linkages and gene expression information. As a case study, we have chosen to analyze UV exposure in wild-type and SOS deficient E. coli at 20 minutes post irradiation. The conditional networks exhibit similar topological properties. Although the global topological properties of the networks are similar, many subtle local changes are observed, which are suggestive of the cellular response to the perturbations. Some such changes correspond to differences in the path lengths among the nodes of carbohydrate metabolism correlating with its loss in efficiency in the UV treated cells. Similarly, expression of hubs under unique conditions reflects the importance of these genes. Various centrality measures applied to the networks indicate increased importance for replication, repair, and other stress proteins for the cells under UV treatment, as anticipated. We thus propose a novel approach for studying an organism at the systems level by integrating genome-wide functional linkages and the gene expression data.

  10. Integrating community based disaster risk reduction and climate change adaptation: examples from the Pacific

    Science.gov (United States)

    Gero, A.; Méheux, K.; Dominey-Howes, D.

    2011-01-01

    It is acknowledged by academics and development practitioners alike that many common strategies addressing community based disaster risk reduction and climate change adaptation duplicate each other. Thus, there is a strong push to integrate the two fields to enhance aid effectiveness and reduce confusion for communities. Examples of community based disaster risk reduction (DRR) and climate change adaptation (CCA) projects are presented to highlight some of the ways these issues are tackled in the Pacific. Various approaches are employed but all aim to reduce the vulnerability and enhance the resilience of local communities to the impacts of climate change and disasters. By focusing on three case studies, elements of best practice are drawn out to illustrate how DRR and CCA can be integrated for enhanced aid effectiveness, and also look at ways in which these two often overlapping fields can be better coordinated in ongoing and future projects. Projects that address vulnerability holistically, and target the overall needs and capacity of the community are found to be effective in enhancing the resilience of communities. By strategically developing a multi-stakeholder and multi-sector approach, community projects are likely to encapsulate a range of experience and skills that will benefit the community. Furthermore, by incorporating local knowledge, communities are far more likely to be engaged and actively participate in the project. From selected case studies, commonly occurring best practice methods to integrate DRR and CCA are identified and discussed and recommendations on how to overcome the common challenges also presented.

  11. Integrating community based disaster risk reduction and climate change adaptation: examples from the Pacific

    Directory of Open Access Journals (Sweden)

    A. Gero

    2011-01-01

    Full Text Available It is acknowledged by academics and development practitioners alike that many common strategies addressing community based disaster risk reduction and climate change adaptation duplicate each other. Thus, there is a strong push to integrate the two fields to enhance aid effectiveness and reduce confusion for communities. Examples of community based disaster risk reduction (DRR and climate change adaptation (CCA projects are presented to highlight some of the ways these issues are tackled in the Pacific. Various approaches are employed but all aim to reduce the vulnerability and enhance the resilience of local communities to the impacts of climate change and disasters. By focusing on three case studies, elements of best practice are drawn out to illustrate how DRR and CCA can be integrated for enhanced aid effectiveness, and also look at ways in which these two often overlapping fields can be better coordinated in ongoing and future projects. Projects that address vulnerability holistically, and target the overall needs and capacity of the community are found to be effective in enhancing the resilience of communities. By strategically developing a multi-stakeholder and multi-sector approach, community projects are likely to encapsulate a range of experience and skills that will benefit the community. Furthermore, by incorporating local knowledge, communities are far more likely to be engaged and actively participate in the project. From selected case studies, commonly occurring best practice methods to integrate DRR and CCA are identified and discussed and recommendations on how to overcome the common challenges also presented.

  12. 3D Printed Reversible Shape Changing Components with Stimuli Responsive Materials

    Science.gov (United States)

    Mao, Yiqi; Ding, Zhen; Yuan, Chao; Ai, Shigang; Isakov, Michael; Wu, Jiangtao; Wang, Tiejun; Dunn, Martin L.; Qi, H. Jerry

    2016-04-01

    The creation of reversibly-actuating components that alter their shapes in a controllable manner in response to environmental stimuli is a grand challenge in active materials, structures, and robotics. Here we demonstrate a new reversible shape-changing component design concept enabled by 3D printing two stimuli responsive polymers—shape memory polymers and hydrogels—in prescribed 3D architectures. This approach uses the swelling of a hydrogel as the driving force for the shape change, and the temperature-dependent modulus of a shape memory polymer to regulate the time of such shape change. Controlling the temperature and aqueous environment allows switching between two stable configurations – the structures are relatively stiff and can carry load in each – without any mechanical loading and unloading. Specific shape changing scenarios, e.g., based on bending, or twisting in prescribed directions, are enabled via the controlled interplay between the active materials and the 3D printed architectures. The physical phenomena are complex and nonintuitive, and so to help understand the interplay of geometric, material, and environmental stimuli parameters we develop 3D nonlinear finite element models. Finally, we create several 2D and 3D shape changing components that demonstrate the role of key parameters and illustrate the broad application potential of the proposed approach.

  13. Integrated Modelling of Climate Change Impacts in an Irrigated, Semi-arid Catchment

    Science.gov (United States)

    Haslauer, C. P.; von Gunten, D.; Wöhling, T.; Rudolph, D. L.; Cirpka, O. A.

    2015-12-01

    Predicting the impacts of climate change on hydrological processes is a central challenge for water management. Commonly, studies on climate-change effects focus on surface flow and feed-backs between surface and subsurface flows are neglected frequently. Furthermore, changes in hydrological processes are generally not distributed realistically. Integrated catchment models, based on partial-differential-equations, have the potential of overcoming these difficulties. However, these models are complicated to use in realistic settings, notably because of their long simulation time. In this presentation, we demonstrate a successful application of an integrated catchment model (HydroGeoSphere) in a semi-arid catchment in north-east Spain. The study area recently underwent a transition to irrigated agriculture, which is reflected in our model evaluations conducted under varying irrigation conditions. To accelerate model calibration, we developed a novel calibration method based on a hierarchy of computational grids. The climate scenarios for the region are based on four regional climate models, which are downscaled using a weather generator. These scenarios are used to estimate climate change impacts on hydrologic parameters in different irrigation settings. The effects of climate change strongly depend on the presence of irrigation. Water table depth and low flows are more sensitive to climate change when irrigation is present, while peak flows exhibit a more pronounced response to climate in scenarios without irrigation. In addition to the climatic means, we examined the impacts of changes in drought conditions. We compare the outcomes of droughts predicted by our hydrological model with simpler approaches based on drought indices. We show that drought indices oversimplify future hydrological impacts of droughts and can result in biased estimation of drought impacts, especially if drought indices do not take temperature changes into account.

  14. Preparation and Properties of Paraffin/TiO2/Active-carbon Composite Phase Change Materials

    Directory of Open Access Journals (Sweden)

    HAO Yong-gan

    2016-11-01

    Full Text Available A novel composite phase change materials (PCMs of paraffin/TiO2/active-carbon was prepared by a microemulsion method, where paraffin acted as a PCM and titanium dioxide (TiO2 as matrix material, and a small amount of active carbon was added to improve the thermal conductivity. The compositions, morphology and thermal properties of the paraffin/TiO2/active-carbon composite PCMs were characterized by XRD, SEM, TGA and DSC respectively. The shape stability during phase change process of this composite was also tested. The results show that paraffin is well encapsulated by TiO2 matrix, and thus exhibiting excellent shape-stabilized phase change feature. Besides, this composite PCM also presents superhydrophobic property. Therefore, these multifunctional features will endow PCMs with important application potential in energy efficient buildings.

  15. Electronic Structure and Spin Configuration Trends of Single Transition Metal Impurity in Phase Change Material

    Science.gov (United States)

    Li, H.; Pei, J.; Shi, L. P.

    2016-10-01

    Fe doped phase change material GexSbyTez has shown experimentally the ability to alter its magnetic properties by phase change. This engineered spin degree of freedom into the phase change material offers the possibility of logic devices or spintronic devices where they may enable fast manipulation of ferromagnetism by a phase change mechanism. The electronic structures and spin configurations of isolated transition metal dopant in phase change material (iTM-PCM) is important to understand the interaction between localized metal d states and the unique delocalized host states of phase change material. Identifying an impurity center that has, in isolation, a nonvanishing magnetic moment is the first step to study the collective magnetic ordering, which originates from the interaction among close enough individual impurities. Theoretical description of iTM-PCM is challenging. In this work, we use a screened exchange hybrid functional to study the single 3d transition metal impurity in crystalline GeTe and GeSb2Te4. By curing the problem of local density functional (LDA) such as over-delocalization of the 3d states, we find that Fe on the Ge/Sb site has its majority d states fully occupied while its minority d states are empty, which is different from the previously predicted electronic configuration by LDA. From early transition metal Cr to heavier Ni, the majority 3d states are gradually populated until fully occupied and then the minority 3d states begin to be filled. Interpretive orbital interaction pictures are presented for understanding the local and total magnetic moments.

  16. Yield asymmetry design of magnesium alloys by integrated computational materials engineering

    Energy Technology Data Exchange (ETDEWEB)

    Li, Dongsheng [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Joshi, Vineet [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lavender, Curt [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Khaleel, Mohammad [Qatar Foundation Research adn Development (Qatar); Ahzi, Said [Univ. of Strasbourg (France)

    2013-11-01

    Deformation asymmetry of magnesium alloys is an important factor on machine design in the automobile industry. Represented by the ratio of compressive yield stress (CYS) against tensile yield stress (TYS), deformation asymmetry is strongly related to texture and grain size. A polycrystalline viscoplasticity model, modified intermediate Φ-model, is used to predict the deformation behavior of magnesium alloys with different grain sizes. Validated with experimental results, integrated computational materials engineering is applied to find out the route in achieving desired asymmetry via thermomechanical processing. For example, CYS/TYS in rolled texture is smaller than 1 under different loading directions. In other textures, such as extruded texture, CYS/TYS is large along the normal direction. Starting from rolled texture, asymmetry will increase to close to 1 along the rolling direction after being compressed to a strain of 0.2. Our modified Φ-model also shows that grain refinement increases CYS/TYS. Along with texture control, grain refinement also can optimize the yield asymmetry. After the grain size decreases to a critical value, CYS/TYS reaches to 1 because CYS increases much faster than TYS. By tailoring the microstructure using texture control and grain refinement, it is achievable to optimize yield asymmetry in wrought magnesium alloys.

  17. Disposal of High-Temperature Slags: A Review of Integration of Heat Recovery and Material Recycling

    Science.gov (United States)

    Sun, Yongqi; Zhang, Zuotai

    2016-09-01

    Nowadays with the continuous urbanization in China, the carbon emission and resource shortage have been serious issues, for which the disposal of blast furnace slags (BFS) and steel slags (SS) discharged from the metallurgical industry make up a significant strategy. The output of crude steel reached 823 Mt in China in 2014 and the thermal heat in these slags was equivalent to ~18 Mt of standard coal. Herein, the recent advances were systemically reviewed and analyzed, mainly from two respects, i.e., integration of heat recovery and material recycling and crystallization control of the slags. It was first found that for the heat recovery from BFS, the most intensively investigated physical method and chemical method were centrifugal granulation and gasification reaction, respectively. Furthermore, a two-step approach could contribute to a promising strategy for the treatment of slags, i.e., the liquid slags were first granulated into small particles, and then other further treatment was performed such as gasification reaction. With regard to SS, the effective disposal could be achieved using a selective crystallization and phase separation (SCPS) method, and moreover, the solid solution of 2CaO·SiO2 and the target phases could act as a promising enriched phase to extract the valuable elements.

  18. Cep57, a NEDD1-binding pericentriolar material component, is essential for spindle pole integrity

    Institute of Scientific and Technical Information of China (English)

    Qixi Wu; Runsheng He; Haining Zhou; Albert CH Yu; Bo Zhang; Junlin Teng; Jianguo Chen

    2012-01-01

    Formation of a bipolar spindle is indispensable for faithful chromosome segregation and cell division.Spindle integrity is largely dependent on the centrosome and the microtubule network.Centrosome protein Cep57 can bundle microtubules in mammalian cells.Its related protein (Cep57R) in Xenopus was characterized as a stabilization factor for microtubule-kinetochore attachment.Here we show that Cep57 is a pericentriolar material (PCM) component.Its interaction with NEDD1 is necessary for the centrosome localization of Cep57.Depletion of Cep57 leads to unaligned chromosomes and a multipolar spindle,which is induced by PCM fragmentation.In the absence of Cep57,centrosome microtubule array assembly activity is weakened,and the spindle length and microtubule density decrease.As a spindle microtubule-binding protein,Cep57 is also responsible for the proper organization of the spindle microtubule and localization of spindle pole focusing proteins.Collectively,these results suggest that Cep57,as a NEDD1binding centrosome component,could function as a spindle pole- and microtubule-stabilizing factor for establishing robust spindle architecture.

  19. Integrity of the Pericentriolar Material Is Essential for Maintaining Centriole Association during M Phase.

    Directory of Open Access Journals (Sweden)

    Mi Young Seo

    Full Text Available A procentriole is assembled next to the mother centriole during S phase and remains associated until M phase. After functioning as a spindle pole during mitosis, the mother centriole and procentriole are separated at the end of mitosis. A close association of the centriole pair is regarded as an intrinsic block to the centriole reduplication. Therefore, deregulation of this process may cause a problem in the centriole number control, resulting in increased genomic instability. Despite its importance for faithful centriole duplication, the mechanism of centriole separation is not fully understood yet. Here, we report that centriole pairs are prematurely separated in cells whose cell cycle is arrested at M phase by STLC. Dispersal of the pericentriolar material (PCM was accompanied. This phenomenon was independent of the separase activity but needed the PLK1 activity. Nocodazole effectively inhibited centriole scattering in STLC-treated cells, possibly by reducing the microtubule pulling force around centrosomes. Inhibition of PLK1 also reduced the premature separation of centrioles and the PCM dispersal as well. These results revealed the importance of PCM integrity in centriole association. Therefore, we propose that PCM disassembly is one of the driving forces for centriole separation during mitotic exit.

  20. Architectural integration of energy solar collectors made with ceramic materials and suitable for the Mediterranean climate

    Directory of Open Access Journals (Sweden)

    J. Roviras

    2016-12-01

    Full Text Available The work presented here aims to demonstrate the technical, architectural and energy viability of solar thermal collectors made with ceramic materials and the Mediterranean climate suitable for the production of domestic hot water (DHW and for heating systems in buildings. The design of a ceramic shell formed by panels collectors and panels no sensors, which are part of the same building system that is capable of responding to the basic requirements of a building envelope and capture solar energy is proposed. Ceramics considerably reduced the final cost of the sensor system and offers the new system a variety of compositional and chromatic since, with reduced performance compared to a conventional metallic collector, can occupy the entire surface of front and get a high degree of architectural integration. A tool for assessing the new ceramic solar collector has been defined from a multi-criteria perspective: economic, environmental and social. The tool enables the comparison of the ceramic solar collector with solar collectors on the market under different climatic and demand conditions.

  1. Material and energy recovery in integrated waste management systems: the potential for energy recovery.

    Science.gov (United States)

    Consonni, Stefano; Viganò, Federico

    2011-01-01

    This article is part of a set of six coordinated papers reporting the main findings of a research project carried out by five Italian universities on "Material and energy recovery in Integrated Waste Management Systems (IWMS)". An overview of the project and a summary of the most relevant results can be found in the introductory article of the series. This paper describes the work related to the evaluation of mass and energy balances, which has consisted of three major efforts (i) development of a model for quantifying the energy content and the elemental compositions of the waste streams appearing in a IWMS; (ii) upgrade of an earlier model to predict the performances of Waste-to-Energy (WtE) plants; (iii) evaluation of mass and energy balances of all the scenarios and the recovery paths considered in the project. Results show that not only the amount of material available for energy recovery is significantly higher than the Unsorted Residual Waste (URW) left after Separate Collection (SC), because selection and recycling generate significant amounts of residues, but its heating value is higher than that of the original, gross waste. Therefore, the energy potential of what is left after recycling is always higher than the complement to 100% of the Source Separation Level (SSL). Also, increasing SSL has marginal effects on the potential for energy recovery: nearly doubling SSL (from 35% to 65%) reduces the energy potential only by one fourth. Consequently, even at high SSL energy recovery is a fundamental step of a sustainable waste management system. Variations of SSL do bring about variations of the composition, heating value and moisture content of the material fed to WtE plants, but these variations (i) are smaller than one can expect; (ii) have marginal effects on the performances of the WtE plant. These considerations suggest that the mere value of SSL is not a good indicator of the quality of the waste management system, nor of its energy and environmental

  2. An investigation on the effects of phase change material on material components used for high temperature thermal energy storage system

    Science.gov (United States)

    Kim, Taeil; Singh, Dileep; Zhao, Weihuan; Yua, Wenhua; France, David M.

    2016-05-01

    The latent heat thermal energy storage (LHTES) systems for concentrated solar power (CSP) plants with advanced power cycle require high temperature phase change materials (PCMs), Graphite foams with high thermal conductivity to enhance the poor thermal conductivity of PCMs. Brazing of the graphite foams to the structural metals of the LHTES system could be a method to assemble the system and a method to protect the structural metals from the molten salts. In the present study, the LHTES prototype capsules using MgCl2-graphite foam composites were assembled by brazing and welding, and tested to investigate the corrosion attack of the PCM salt on the BNi-4 braze. The microstructural analysis showed that the BNi-4 braze alloy can be used not only for the joining of structure alloy to graphite foams but also for the protecting of structure alloy from the corrosion by PCM.

  3. Comparative Effectiveness of Different Phase Change Materials to Improve Cooling Performance of Heat Sinks for Electronic Devices

    Directory of Open Access Journals (Sweden)

    Ahmad Hasan

    2016-08-01

    Full Text Available This paper thermo-physically characterizes salt hydrate, paraffin wax and milk fat as phase change materials (PCMs. The three PCMs are compared in terms of improving heat sink (HS performance for cooling electronic packaging. An experimental study is carried out on commercially available finned HS with and without PCM under natural ventilation (NV and forced ventilation (FV at different heat loads (4 W to 10 W. The results indicate that integration of all of the PCMs into the HS improves its cooling performance; however, milk fat lags behind the other two PCMs in terms of cooling produced. A three-dimensional pressure-based conjugate heat transfer model has been developed and validated with experimental results. The model predicts the parametric influence of PCM melting range, thermal conductivity and density on HS thermal management performance. The HS cooling performance improves with increased density and conductivity while it deteriorates with the wider melting range of the PCMs.

  4. Integration

    DEFF Research Database (Denmark)

    Emerek, Ruth

    2004-01-01

    Bidraget diskuterer de forskellige intergrationsopfattelse i Danmark - og hvad der kan forstås ved vellykket integration......Bidraget diskuterer de forskellige intergrationsopfattelse i Danmark - og hvad der kan forstås ved vellykket integration...

  5. Optimization Using Metamodeling in the Context of Integrated Computational Materials Engineering (ICME)

    Energy Technology Data Exchange (ETDEWEB)

    Hammi, Youssef; Horstemeyer, Mark F; Wang, Paul; David, Francis; Carino, Ricolindo

    2013-11-18

    Predictive Design Technologies, LLC (PDT) proposed to employ Integrated Computational Materials Engineering (ICME) tools to help the manufacturing industry in the United States regain the competitive advantage in the global economy. ICME uses computational materials science tools within a holistic system in order to accelerate materials development, improve design optimization, and unify design and manufacturing. With the advent of accurate modeling and simulation along with significant increases in high performance computing (HPC) power, virtual design and manufacturing using ICME tools provide the means to reduce product development time and cost by alleviating costly trial-and-error physical design iterations while improving overall quality and manufacturing efficiency. To reduce the computational cost necessary for the large-scale HPC simulations and to make the methodology accessible for small and medium-sized manufacturers (SMMs), metamodels are employed. Metamodels are approximate models (functional relationships between input and output variables) that can reduce the simulation times by one to two orders of magnitude. In Phase I, PDT, partnered with Mississippi State University (MSU), demonstrated the feasibility of the proposed methodology by employing MSU?s internal state variable (ISV) plasticity-damage model with the help of metamodels to optimize the microstructure-process-property-cost for tube manufacturing processes used by Plymouth Tube Company (PTC), which involves complicated temperature and mechanical loading histories. PDT quantified the microstructure-property relationships for PTC?s SAE J525 electric resistance-welded cold drawn low carbon hydraulic 1010 steel tube manufacturing processes at seven different material states and calibrated the ISV plasticity material parameters to fit experimental tensile stress-strain curves. PDT successfully performed large scale finite element (FE) simulations in an HPC environment using the ISV plasticity

  6. The effects of microstructural changes caused by welding on microbiologically influenced corrosion: Material and process implications

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, D.W.; Willis, E.R.; Van Diepen, T. [California Polytechnic State Univ., San Luis Obispo, CA (United States). Materials Engineering Dept.

    1995-10-01

    The microbiologically influenced corrosion (MIC) susceptibility of a material is inextricably linked to its microstructure. The thermomechanical cycle associated with welding produces extensive microstructural change in the vicinity of the weld. This work tested the hypothesis that fabrication procedure would alter MIC susceptibility. This study examined the effect of systematic variation in the amounts of cerium, sulfur and silicon on the corrosion susceptibility of welded AISI 8630 material in aqueous, anaerobic solutions. Samples were exposed to both sterile and biologically solutions. Biologically active solutions were invariably more aggressive. The changes in corrosion susceptibility were correlated to the changes in the microstructure of the weld fusion zone, the partially melted zone (PMZ) and the base material, as affected by minor element content. Significant correlations between total numbers of pits/maximum pit depth and minor element content/location of attack were found in this study. The creation of extensive subgrain boundary coupled with solute redistribution in the fusion zone as well as extensive continuous grain boundary films in the partially melted zone foster MIC in these locations. Mitigation strategies treating material selection and weld process/procedure selection are discussed.

  7. Phase Change Material on Augmentation of Fresh Water Production Using Pyramid Solar Still

    Directory of Open Access Journals (Sweden)

    S. Ravishankara

    2013-10-01

    Full Text Available The augmentation of fresh water and increase in the solar still efficiency of a triangular pyramid is added with phase change material (PCM on the basin. Experimental studies were conducted and the effects of production of fresh water with and without PCM were investigated. Using paraffin as the PCM material, performance of the solar still were conducted on a hot, humid climate of Chennai (13°5′ 2" North, 80°16′ 12"East, India. The use of paraffin wax increases the latent heat storage so that the energy is stored in the PCM and in the absence of solar radiation it rejects its stored heat into the basin for further evaporation of water from the basin. Temperatures of water, Tw, Temperature of phase change material, TPCM, Temperature of cover, Tc were measured using thermocouple. Results show that there is an increase of maximum 20%, in productivity of fresh water with PCM. Keywords: fresh water production; PCM; thermal energy storage; phase change material

  8. Experimental investigation of performances of microcapsule phase change material for thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Li, H. [Department of Material Science and Engineering, Nanjing University, Nanjing (China); Liu, X.; Wu, S. [Department of Physics, Nanjing University, Nanjing (China); Fang, G.

    2010-02-15

    Performances of microcapsule phase change material (MPCM) for thermal energy storage are investigated. The MPCM for thermal energy storage is prepared by a complex coacervation method with gelatin and acacia as wall materials and paraffin as core material in an emulsion system. A scanning electron microscope (SEM) was used to study the microstructure of the MPCM. In thermal analysis, a differential scanning calorimeter (DSC) was employed to determine the melting temperature, melting latent heat, solidification temperature, and solidification latent heat of the MPCM for thermal energy storage. The SEM micrograph indicates that the MPCM has been successfully synthesized and that the particle size of the MPCM is about 81 {mu}m. The DSC output results show that the melting temperature of the MPCM is 52.05 C, the melting latent heat is 141.03 kJ/kg, the solidification temperature is 59.68 C, and the solidification latent heat is 121.59 kJ/kg. The results prove that the MPCM for thermal energy storage has a larger phase change latent heat and suitable phase change temperature, so it can be considered as an efficient thermal energy storage material for heat utilizing systems. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  9. Integrated assessment of vulnerability to climate change and adaptation options in the Netherlands

    Energy Technology Data Exchange (ETDEWEB)

    Van Ierland, E.C.; De Groot, R.S.; Kuikman, P.J.; Martens, P.; Amelung, B.; Daan, N.; Huynen, M.; Kramer, K.; Szoenyi, J.; Veraart, J.A.; Verhagen, A.; Van Vliet, A.; Van Walsum, P.E.V.; Westein, E. [Alterra, Wageningen, and International Centre for Integrative Studies, Maastricht University, Maastricht (Netherlands)

    2001-07-01

    In recent decades, it has become increasingly clear that the global climate is becoming warmer and that regional climates are changing. This report summarizes the results of an integrated assessment of vulnerability to climate change and adaptation options in the Netherlands carried out between July 2000 and July 2001 within the framework of the Dutch National Research Program on Global Air Pollution and Climate Change (NRP-2). The project's main aims were: - to provide an overview of scientific insights, expert judgements and stakeholders' perceptions of current and future impacts (positive and negative) of climate change for several economic sectors, human health, and natural systems in the Netherlands, considering various cross-sectoral interactions, - to develop a set of adaptation options for these sectors through a participatory process with the main stakeholders, - to perform an integrated assessment of cross-sectoral interactions of climate change impacts and adaptation options. Climate change impacts and adaptation options have been investigated for several important economic sectors (including agriculture, forestry, fisheries, industry, energy, transport, insurance and recreation and tourism), human health and natural systems (including soils, water and biodiversity issues).The results of this study are based on literature survey, a dialogue with experts and stakeholders. We are convinced that the report represents the most essential and relevant aspects of the impacts and adaptation options for climate change in the Netherlands, given the scenario setting of this study, the state of the art of current scientific knowledge, and today's expert and stakeholders' perceptions of the issues at stake. 215 refs.

  10. 76 FR 28336 - Domestic Licensing of Source Material-Amendments/Integrated Safety Analysis

    Science.gov (United States)

    2011-05-17

    ..., staff document entitled ``A Comparison of Integrated Safety Analysis and Probabilistic Risk Assessment... Integrated Safety Analysis (ISA) and Probabilistic Risk Assessment (PRA) for Fuel Cycle Facilities... Safety Analysis AGENCY: Nuclear Regulatory Commission. ACTION: Proposed rule. SUMMARY: The U.S....

  11. Effects of Microencapsulated Phase Change Material (MPCM) on Critical Heat Flux in Pool Boiling

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung Dae; Kim, Seong Man; Kang, Sarah; Lee, Seung Won; Seo, Han; Bang, In Cheol [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2011-10-15

    Thermal power is limited by critical heat flux (CHF) in the nuclear power plant. And the in-vessel retention by external reactor vessel cooling (IVR-ERVC) is applied in some nuclear power plants; AP600, AP1000, Loviisa and APR1400. The heat removal capacity of IVR-ERVC is also restricted by CHF. So, it is essential to get CHF margin to improve an economics and a safety of the plant. There are some typical approaches to enhance CHF: vibrating the heater or fluid, coating with porous media on the heater surface, applying an electric field. The recent study related to the CHF is focus on using the nanofluid. In this paper, the new approach was investigated by using the microencapsulated phase change material (MPCM). MPCM is the particles whose diameter is from 0.1{mu}m to 1000{mu}m. The MPCM consists of the core material and the shell material. The core material can be solid, liquid, gas or even the mixture. The solid paraffin is the best candidate as the core material due to its stable chemical and thermal properties. And the shell material is generally synthesized polymer of about several micrometers in thickness. The most interesting feature of the MPCM is that the latent heat associated with the solid-liquid phase change is related to the heat transfer. When the MPCM is dispersed into the carrier fluid, a kind of suspension named as microencapsulated phase change slurry (MPCS) is formed. The study on the MPCS was conducted in field of both the heat transfer fluids and energy storage media. It is inspired by the fact that the latent heat can serve distribution to the additional CHF margin. The purpose of this work is to confirm whether or not the CHF is enhanced

  12. The Digital Ageing Atlas: integrating the diversity of age-related changes into a unified resource.

    Science.gov (United States)

    Craig, Thomas; Smelick, Chris; Tacutu, Robi; Wuttke, Daniel; Wood, Shona H; Stanley, Henry; Janssens, Georges; Savitskaya, Ekaterina; Moskalev, Alexey; Arking, Robert; de Magalhães, João Pedro

    2015-01-01

    Multiple studies characterizing the human ageing phenotype have been conducted for decades. However, there is no centralized resource in which data on multiple age-related changes are collated. Currently, researchers must consult several sources, including primary publications, in order to obtain age-related data at various levels. To address this and facilitate integrative, system-level studies of ageing we developed the Digital Ageing Atlas (DAA). The DAA is a one-stop collection of human age-related data covering different biological levels (molecular, cellular, physiological, psychological and pathological) that is freely available online (http://ageing-map.org/). Each of the >3000 age-related changes is associated with a specific tissue and has its own page displaying a variety of information, including at least one reference. Age-related changes can also be linked to each other in hierarchical trees to represent different types of relationships. In addition, we developed an intuitive and user-friendly interface that allows searching, browsing and retrieving information in an integrated and interactive fashion. Overall, the DAA offers a new approach to systemizing ageing resources, providing a manually-curated and readily accessible source of age-related changes.

  13. A Super Cooled, Non-toxic, Non-flammable Phase Change Material Thermal Pack for Portable Life Support Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The continuation of concept development and test of a water-based, advanced Phase Change Material (PCM) heat sink is proposed. Utilizing a novel material choice for...

  14. A Super Cooled, Non-toxic, Non-flammable Phase Change Material Thermal Pack for Portable Life Support Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The concept development and test of a water-based, advanced Phase Change Material (PCM) heat sink is proposed. Utilizing a novel material choice for both an...

  15. Electrical properties of Cr-doped Sb2Te3 phase change material

    Science.gov (United States)

    Wang, Qing; Liu, Bo; Xia, Yangyang; Zheng, Yonghui; Song, Sannian; Cheng, Yan; Song, Zhitang; Feng, Songlin

    2016-10-01

    Phase Change Memory (PCM) is regarded as one of the most promising candidates for the next-generation nonvolatile memory. Its storage medium, phase change material, has attracted continuous exploration. Sb2Te3 is a high-speed phase change material matrix with low crystallization temperature. Cr-doped Sb2Te3 (CST) films with suitable composition have been studied and proved to be a promising novel phase change material with high speed and good thermal stability. In this paper, detailed Rs-T characteristics and Hall characteristics of the CST films are studied. We find that, when more parts of the film crystallizes into the ordered structure, the activation energy for electrical conduction (Eσ) decreases, indicating that the semiconductor property is weakened. And with the increase of Cr-dopants, Eσ of the As-deposited (As-de) amorphous CST films decreases, thus the thermal stability of resistance is improved. Hall results show that Sb2Te3 and CST films are all in P-type. For As-de amorphous films, with the increase of Cr-dopants, the carrier mobility decreases all along, while the carrier density decreases at first and then increases. For the crystalline films, with the increase of Cr-dopants, the carrier mobility decreases, while the carrier density increases.

  16. Numerical analysis of phase change materials for thermal control of power battery of high power dissipations

    Science.gov (United States)

    Xia, X.; Zhang, H. Y.; Deng, Y. C.

    2016-08-01

    Solid-fluid phase change materials have been of increasing interest in various applications due to their high latent heat with minimum volume change. In this work, numerical analysis of phase change materials is carried out for the purpose of thermal control of the cylindrical power battery cells for applications in electric vehicles. Uniform heat density is applied at the battery cell, which is surrounded by phase change material (PCM) of paraffin wax type and contained in a metal housing. A two-dimensional geometry model is considered due to the model symmetry. The effects of power densities, heat transfer coefficients and onset melting temperatures are examined for the battery temperature evolution. Temperature plateaus can be observed from the present numerical analysis for the pure PCM cases, with the temperature level depending on the power densities, heat transfer coefficients, and melting temperatures. In addition, the copper foam of high thermal conductivity is inserted into the copper foam to enhance the heat transfer. In the modeling, the local thermal non-equilibrium between the metal foam and the PCM is taken into account and the temperatures for the metal foam and PCM are obtained respectively.

  17. Change in color of a maxillofacial prosthetic silicone elastomer, following investment in molds of different materials

    Science.gov (United States)

    Sethi, Tania; Kheur, Mohit; Coward, Trevor; Patel, Naimesha

    2015-01-01

    Purpose: In the authors’ experience, the color of silicone elastomer following polymerization in molds made of gypsum products is slightly different from the color that was matched in the presence of the patient, before the silicone is packed. It is hypothesized that the investing materials and separating media have an effect on the color during the polymerization process of the silicone. Materials and Methods: This study compares and evaluates the change in color of silicone elastomer packed in three commonly used investing materials - Dental stone (white color), dental stone (green color), and die stone (orange color); coated with three different separating media – Alginate-based medium, soap solution and a resin-based die hardening material. Pigmented silicone samples of dimensions 1.5 cm × 2 cm × 0.5 cm were made from the elastomer in the above-mentioned mold materials using combinations of the mentioned separating media. These served as test group samples. Control group samples were made by packing a mix of the same pigmented elastomer in stainless steel molds. The L*, a*, b* values of the test and control group samples were determined using a spectrophotometer. The change in color (Delta E) was calculated between the control and test groups. Results: The mean L, a, b values for the control group were, 31.8, 26.2, and 36.3, respectively. Average values of change in color (Delta E) for samples packed utilizing alginate-based medium, die hardener, and soap solution, respectively in white dental stone (2.70, 2.74, and 2.88), green dental stone (2.19, 2.23, 2.42), and orange die stone (3.19, 2.72, 2.80) were tabulated. Conclusion: Among the investing materials studied, die stone showed the most color change (3.19), which was statistically significant. Among the separating media, die hardener showed the least color change (2.23). The best combination of an investing material and separating media as per this investigation is a dental stone (green) and alginate

  18. Melting of Nanoprticle-Enhanced Phase Change Material inside Shell and Tube Heat Exchanger

    Directory of Open Access Journals (Sweden)

    Seiyed Mohammad Javad Hosseini

    2013-01-01

    Full Text Available This paper presents a numerical study of melting of Nanoprticle-Enhanced phase change material (NEPCM inside a shell and tube heat exchanger using RT50 and copper particles as base material and nanoparticle, respectively. In this study, the effects of nanoparticles dispersion (, 0.03, and 0.05 on melting time, liquid fraction, and penetration length are investigated. The results show that the melting time decreases to 14.6% and the penetration length increases to 146% with increasing volume fraction of nanoparticle up to .

  19. Mathematical Modeling and Simulations of Phase Change Materials in Basic Orthogonal Coordinate Systems

    Energy Technology Data Exchange (ETDEWEB)

    Rousse, Daniel; Dutil, Yvan; Ben Salah, Nizar; Lassue, Stephane

    2010-09-15

    Energy storage components improve the energy efficiency of systems by reducing the mismatch between supply and demand. Phase change materials are attractive since they provide a high energy storage density at constant temperatures. Nevertheless, the incorporation of such materials in a particular application often calls for numerical analyses due to the non-linear nature of the problem. The review of the mathematical models will include selected results to enable one to start his/her research with an exhaustive overview of the subject. This overview also stresses the need to match experimental investigations with recent numerical analyses.

  20. Preparation and characterization of phase change material for thermal energy storage in buildings

    Science.gov (United States)

    Lo, Tommy Y.

    2016-04-01

    The paper presents the developing of novel form-stable composite phase change material (PCM) by incorporation of paraffin into lightweight aggregate through vacuum impregnation. The macro-encapsulated Paraffin-lightweight aggregate is a chemical compatible, thermal stable and thermal reliable PCM material for thermal energy storage applications in buildings. The 28 days compressive strength of NWAC using PCM-LWA is 33 - 53 MPa, which has an opportunity for structural purpose. Scanning electronic microscopic images indicated the paraffin can be held inside the porous structure of the aggregate. Thermal performance test showed that the cement paste panel with composite PCM can reduce the indoor temperature.

  1. Osteoblast integration of dental implant materials after challenge by sub-gingival pathogens : a co-culture study in vitro

    NARCIS (Netherlands)

    Zhao, Bingran; van der Mei, Henny C.; Rustema-Abbing, Minie; Busscher, Henk J.; Ren, Yijin

    2015-01-01

    Sub-gingival anaerobic pathogens can colonize an implant surface to compromise osseointegration of dental implants once the soft tissue seal around the neck of an implant is broken. In vitro evaluations of implant materials are usually done in monoculture studies involving either tissue integration

  2. Mechanical-property changes of polymeric and composite materials after low-temperature proton irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Snead, C.L. Jr.; Czajkowski, C.J.; Skaritka, J. [Brookhaven National Lab., Upton, NY (United States). Dept. of Advanced Technology; Morena, J. [Ace Inc., Stuart, FL (United States)

    1999-02-01

    The mechanical properties of polymeric and composite materials are known to be sensitive to ionizing radiation. Most of the existing data, however, is the result of near-room-temperature irradiations, most commonly with {sup 60}Co gamma irradiation. For use of these materials in applications such as for magnetic fusion magnets, where operation will be at cryogenic temperatures in sometimes severe radiation fields, knowledge of the materials` radiation response to low-temperature irradiations is required. This paper reports the results of mechanical-property-change measurements made at 4.2K on a number of potential magnet materials following 200-MeV-proton irradiation at temperatures below 20K. Standard three-point bend tests were performed at 4.2K for short-beam shear determinations in the laminate materials and for shear strength in the remainder of the specimens. Specimens were warmed to room temperature for one week prior to the mechanical testing in order to emulate the expected the expected mechanical state of the material assuming room-temperature cycling in the expected magnet applications. Data are presented in the form of yield stresses before and after irradiations with percentages of change. There were five specimens per test dose for each material. Data are presented for exposures ranging from nominally 10{sup 7} to 10{sup 9} rad. Results of the mechanical tests range from complete delamination and distortion of the specimens at 10{sup 9} rad to an increase in the yield stress of 63% after 10{sup 9} rad. The latter specimen did, however, evidence significant embrittlement. The phenomenon of irradiation-induced strengthening due to enhanced cross linking in undercured polymers was observed in some cases.

  3. ON IMPROVING AN INTEGRATED INVENTORY MODEL FOR A SINGLE VENDOR AND MULTIPLE BUYERS WITH A RELAXED MATERIAL ORDERING CYCLE POLICY

    Institute of Scientific and Technical Information of China (English)

    Yugang YU; Feng CHU; Haoxun CHEN

    2006-01-01

    In this paper, we propose a new model for improving the lot size obtained with the model of Woo, Hsu, and Wu (2001) proposed in their paper "An integrated inventory model for a single vendor and multiple buyers with ordering cost reduction" (Int. J. Production Economics 73 203-215). The new model can provide a lower or equal joint total cost as compared to Woo, Hsu, and Wu's model due to the relaxation of their integral multiple material ordering cycle policy to a fractional-integral multiple material ordering cycle policy. The proposed model is analyzed and an algorithm for calculating the optimal lot size of the model is developed. A numerical study based on the example used by Woo, Hsu, and Wu is presented.

  4. New Integration Period? Changing Tendencies of the Urban Network in South East Europe

    Directory of Open Access Journals (Sweden)

    Szilárd Rácz

    2014-09-01

    Full Text Available The past two decades have brought basic changes in the whole Balkan Peninsula, where spatial structures and settlement network were not devoid of changes either. Due to the change of the economic, political and social regime and the new borders spatial structures became differentiated along new factors. Cooperation programs of the Euro-Atlantic integration hold many new challenges and opportunities. Historical and political literature studying the single countries’ transformation is large and far reaching, however, a settlement network and spatial structure focused overview has been, so far, missing from the range of researches. The aim of this study is to examine the urban features and the spatial transition of the Balkan states.

  5. Integrating climate change adaptation in energy planning and decision-making - Key challenges and opportunities

    DEFF Research Database (Denmark)

    Olhoff, Anne; Olsen, Karen Holm

    2011-01-01

    Energy systems are significantly vulnerable to current climate variability and extreme events. As climate change becomes more pronounced, the risks and vulnerabilities will be exacerbated. To date, energy sector adaptation issues have received very limited attention. In this paper, a climate risk...... management framework is used as the basis for identifying key challenges and opportunities to enhance the integration of climate change adaptation in energy planning and decision-making. Given its importance for raising awareness and for stimulating action by planners and decision-makers, emphasis is placed...... on reviewing the current knowledge on risks and vulnerabilities of energy systems and on potential adaptation options. The paper finds that short and longer term action on climate risk management of energy systems strongly depends on: Strengthening the capacity to model and project climate change and its...

  6. Energy Saving Potentials of Phase Change Materials Applied to Lightweight Building Envelopes

    Directory of Open Access Journals (Sweden)

    Yoon-Bok Seong

    2013-10-01

    Full Text Available Phase change materials (PCMs have been considered as an innovative technology that can reduce the peak loads and heating, ventilating and air conditioning (HVAC energy consumption in buildings. Basically they are substances capable of storing or releasing thermal energy as latent heat. Because the amount of latent heat absorbed or released is much larger than the sensible heat, the application of PCMs in buildings has significant potential to reduce energy consumption. However, because each PCM has its own phase change temperature, which is the temperature at which latent heat is absorbed or released, it is important to use an appropriate PCM for the purpose of building envelope design. Therefore, this paper aims to investigate the energy saving potentials in buildings when various PCMs with different phase change temperatures are applied to a lightweight building envelope by analyzing the thermal load characteristics. As results, the annual heating load increased at every phase change temperature, but the peak heating load decreased by 3.19% with heptadecane (phase change temperature 21 °C, and the lowest indoor temperature increased by 0.86 °C with heptadecane (phase change temperature 21 °C. The annual cooling load decreased by 1.05% with dodecanol (phase change temperature 24 °C, the peak cooling load decreased by 1.30% with octadecane (phase change temperature 29 °C, and the highest indoor temperature dropped by 0.50 °C with octadecane (phase change temperature 29 °C. When the night ventilation was applied to the building HVAC system for better passive cooling performance, the annual cooling load decreased by 9.28% with dodecanol (phase change temperature 24 °C, the peak load decreased by 11.33% with octadecane (phase change temperature 29 °C, and the highest indoor temperature dropped by 0.85 °C with octadecane (phase change temperature 29 °C.

  7. Integrated monitoring and information systems for managing aquatic invasive species in a changing climate

    Science.gov (United States)

    Lee, Henry; Reusser, Deborah A.; Olden, Julian D.; Smith, Scott S.; Graham, Jim; Burkett, Virginia; Dukes, Jeffrey S.; Piorkowski, Robert J.; Mcphedran, John

    2008-01-01

    Changes in temperature, precipitation, and other climatic drivers and sea-level rise will affect populations of existing native and non-native aquatic species and the vulnerability of aquatic environments to new invasions. Monitoring surveys provide the foundation for assessing the combined effects of climate change and invasions by providing baseline biotic and environmental conditions, although the utility of a survey depends on whether the results are quantitative or qualitative, and other design considerations. The results from a variety of monitoring programs in the United States are available in integrated biological information systems, although many include only non-native species, not native species. Besides including natives, we suggest these systems could be improved through the development of standardized methods that capture habitat and physiological requirements and link regional and national biological databases into distributed Web portals that allow drawing information from multiple sources. Combining the outputs from these biological information systems with environmental data would allow the development of ecological-niche models that predict the potential distribution or abundance of native and non-native species on the basis of current environmental conditions. Environmental projections from climate models can be used in these niche models to project changes in species distributions or abundances under altered climatic conditions and to identify potential high-risk invaders. There are, however, a number of challenges, such as uncertainties associated with projections from climate and niche models and difficulty in integrating data with different temporal and spatial granularity. Even with these uncertainties, integration of biological and environmental information systems, niche models, and climate projections would improve management of aquatic ecosystems under the dual threats of biotic invasions and climate change

  8. An integrated model to simulate sown area changes for major crops at a global scale

    Institute of Scientific and Technical Information of China (English)

    SHIBASAKI; Ryosuke

    2008-01-01

    Dynamics of land use systems have attracted much attention from scientists around the world due to their ecological and socio-economic implications. An integrated model to dynamically simulate future changes in sown areas of four major crops (rice, maize, wheat and soybean) on a global scale is pre- sented. To do so, a crop choice model was developed on the basis of Multinomial Logit (Logit) model to model land users’ decisions on crop choices among a set of available alternatives with using a crop utility function. A GIS-based Environmental Policy Integrated Climate (EPIC) model was adopted to simulate the crop yields under a given geophysical environment and farming management conditions, while the International Food Policy and Agricultural Simulation (IFPSIM) model was utilized to estimate crop price in the international market. The crop choice model was linked with the GIS-based EPIC model and the IFPSIM model through data exchange. This integrated model was then validated against the FAO statistical data in 2001-2003 and the Moderate Resolution Imaging Spectroradiometer (MODIS) global land cover product in 2001. Both validation approaches indicated reliability of the model for ad- dressing the dynamics in agricultural land use and its capability for long-term scenario analysis. Finally, the model application was designed to run over a time period of 30 a, taking the year 2000 as baseline. The model outcomes can help understand and explain the causes, locations and consequences of land use changes, and provide support for land use planning and policy making.

  9. Changing Academic Medicine: Strategies Used by Academic Leaders of Integrative Medicine—A Qualitative Study

    Directory of Open Access Journals (Sweden)

    Claudia M. Witt

    2012-01-01

    Full Text Available In Western countries, complementary and alternative medicine (CAM is more and more provided by practitioners and family doctors. To base this reality of health care provision on an evidence-base, academic medicine needs to be included in the development. In the study we aimed to gain information on a structured approach to include CAM in academic health centers. We conducted a semistructured interview study with leading experts of integrative medicine to analyze strategies of existing academic institutions of integrative medicine. The study sample consisted of a purposive sample of ten leaders that have successfully integrated CAM into medical schools in the USA, Great Britain, and Germany and the Director of the National Center for Alternative and Complementary Medicine. Analysis was based on content analysis. The prerequisite to foster change in academic medicine was a strong educational and professional background in academic medicine and research methodologies. With such a skill set, the interviewees identified a series of strategies to align themselves with colleagues from conventional medicine, such as creating common goals, networking, and establishing well-functioning research teams. In addition, there must be a vision of what should be needed to be at the center of all efforts in order to implement successful change.

  10. Changing academic medicine: strategies used by academic leaders of integrative medicine-a qualitative study.

    Science.gov (United States)

    Witt, Claudia M; Holmberg, Christine

    2012-01-01

    In Western countries, complementary and alternative medicine (CAM) is more and more provided by practitioners and family doctors. To base this reality of health care provision on an evidence-base, academic medicine needs to be included in the development. In the study we aimed to gain information on a structured approach to include CAM in academic health centers. We conducted a semistructured interview study with leading experts of integrative medicine to analyze strategies of existing academic institutions of integrative medicine. The study sample consisted of a purposive sample of ten leaders that have successfully integrated CAM into medical schools in the USA, Great Britain, and Germany and the Director of the National Center for Alternative and Complementary Medicine. Analysis was based on content analysis. The prerequisite to foster change in academic medicine was a strong educational and professional background in academic medicine and research methodologies. With such a skill set, the interviewees identified a series of strategies to align themselves with colleagues from conventional medicine, such as creating common goals, networking, and establishing well-functioning research teams. In addition, there must be a vision of what should be needed to be at the center of all efforts in order to implement successful change.

  11. Distinguishing complex ideas about climate change: knowledge integration vs. specific guidance

    Science.gov (United States)

    Vitale, Jonathan M.; McBride, Elizabeth; Linn, Marcia C.

    2016-06-01

    We compared two forms of automated guidance to support students' understanding of climate change in an online inquiry science unit. For specific guidance, we directly communicated ideas that were missing or misrepresented in student responses. For knowledge integration guidance, we provided hints or suggestions to motivate learners to analyze features of their response and seek more information. We guided both student-constructed energy flow diagrams and short essays at total of five times across an approximately week-long curriculum unit. Our results indicate that while specific guidance typically produced larger accuracy gains on responses within the curriculum unit, knowledge integration guidance produced stronger outcomes on a novel essay at posttest. Closer analysis revealed an association between the time spent revisiting a visualization and posttest scores on this summary essay, only for those students in the knowledge integration condition. We discuss how these gains in knowledge integration extend laboratory results related to 'desirable difficulties' and show how autonomous inquiry can be fostered through automated guidance.

  12. Integrating the system dynamic and cellular automata models to predict land use and land cover change

    Science.gov (United States)

    Xu, Xiaoming; Du, Ziqiang; Zhang, Hong

    2016-10-01

    Land use and land cover change (LULCC) is a widely researched topic in related studies. A number of models have been established to simulate LULCC patterns. However, the integration of the system dynamic (SD) and the cellular automata (CA) model have been rarely employed in LULCC simulations, although it allows for combining the advantages of each approach and therefore improving the simulation accuracy. In this study, we integrated an SD model and a CA model to predict LULCC under three future development scenarios in Northern Shanxi province of China, a typical agro-pastoral transitional zone. The results indicated that our integrated approach represented the impacts of natural and socioeconomic factors on LULCC well, and could accurately simulate the magnitude and spatial pattern of LULCC. The modeling scenarios illustrated that different development pathways would lead to various LULCC patterns. This study demonstrated the advantages of the integration approach for simulating LULCC and suggests that LULCC is affected to a large degree by natural and socioeconomic factors.

  13. Ultrafast optical manipulation of atomic motion in multilayer Ge-Sb-Te phase change materials

    Directory of Open Access Journals (Sweden)

    Fons P.

    2013-03-01

    Full Text Available Phase change random access memory devices have evolved dramatically with the recent development of superlattice structure of Ge-Sb-Te material (GST-SL in terms of its low power consumption. The phase change in GST-SL is mainly characterized by the displacement of Ge atoms. Here we examine a new phase change method, that is the manipulation of Ge-Te bonds using linearly-polarized femtosecond near-infrared optical pulses. As a result, we found that the p-polarized pump pulse is more effective in inducing the reversible and irreversible displacement of Ge atoms along [111] direction in the local structure. This structural change would be induced by the anisotropic carrier-phonon interaction along the [111] direction created by the p-polarized pulse.

  14. Si1Sb2Te3 phase change material for chalcogenide random access memory

    Institute of Scientific and Technical Information of China (English)

    Zhang Ting; Song Zhi-Tang; Liu Bo; Liu Wei-Li; Feng Song-Lin; Chen Bomy

    2007-01-01

    This paper investigated phase change Si1Sb2Te3 material for application of chalcogenide random access memory.Current-voltage performance was conducted to determine threshold current of phase change from amorphous phase to polycrystalline phase.The film holds a threshold current about 0.155 mA,which is smaller than the value 0.31 mA of Ge2Sb2Te5 film.Amorphous Si1Sb2Te3 changes to face-centred-cubic structure at~180°C and changes to hexagonal structure at~270°C.Annealing temperature dependent electric resistivity of Si1Sb2Te3 film was studied by four-point probe method.Data retention of the films was characterized as well.

  15. From rice husk to high performance shape stabilized phase change materials for thermal energy storage

    DEFF Research Database (Denmark)

    Mehrali, Mohammad; Latibari, Sara Tahan; Rosen, Marc A.

    2016-01-01

    exceptional phase change behavior, having a desirable latent heat storage capacity of 175 kJ kg(-1). When exposed to high solar radiation intensities, the composites can absorb and store the thermal energy. An FTIR analysis of the SSPCMs indicated that there was no chemical interaction between the palmitic...... and excellent reversibility. The prepared SSPCMs with enhanced heat transfer and phase change properties provide a beneficial option for building energy conservation and solar energy applications owing to the low cost of raw materials and the simple synthetic technique....

  16. Review of Development Survey of Phase Change Material Models in Building Applications

    Directory of Open Access Journals (Sweden)

    Hussein J. Akeiber

    2014-01-01

    Full Text Available The application of phase change materials (PCMs in green buildings has been increasing rapidly. PCM applications in green buildings include several development models. This paper briefly surveys the recent research and development activities of PCM technology in building applications. Firstly, a basic description of phase change and their principles is provided; the classification and applications of PCMs are also included. Secondly, PCM models in buildings are reviewed and discussed according to the wall, roof, floor, and cooling systems. Finally, conclusions are presented based on the collected data.

  17. A Review On Free Cooling Through Heat Pipe by Using Phase Change Materials

    Directory of Open Access Journals (Sweden)

    A.S.Futane ,

    2011-06-01

    Full Text Available Thermal energy storage is renewable source of energy to develop energy storage system, which minimize environmental impact such as ozone depletion and global warming. Thermal energy can be stored as latent heat which is latter use when substance changes from one phase to another phase by either freezing or melting. Now a days need of refrigeration and air conditioning has been increased, which can be achieved by free cooling, for this various substances are use, depending upon required temperature. Phase change materials are one of the substances having low temperature of melting and solidification.

  18. Integrated assessment and changes of ecological environment in the Daning River Watershed

    Institute of Scientific and Technical Information of China (English)

    LIU Ruimin; SHEN Zhenyao

    2007-01-01

    Based on Remote Sensing (RS),Geographical Information Systems (GIS),and the Spatial Principal Component Analysis (SPCA) method,the integrated assessment and changes in the ecological environment of Daning River Watershed are studied in this paper.The watershed is located in the Three Gorge Area in China.The result of the integrated assessment showed that level 9 had the biggest proportion in the year 1990,which was about 40%.In the year 2000,however,there were no levels with a proportion significantly bigger than the others.By comparing the assessment results in 1990 and 2000,it is discovered that the ecological environment in Daning River Watershed in 1990 was better than that in 2000.

  19. Thermal Response Of An Aerated Concrete Wall With Micro-Encapsulated Phase Change Material

    Directory of Open Access Journals (Sweden)

    Halúzová Dušana

    2015-06-01

    Full Text Available For many years Phase Change Materials (PCM have attracted attention due to their ability to store large amounts of thermal energy. This property makes them a candidate for the use of passive heat storage. In many applications, they are used to avoid the overheating of the temperature of an indoor environment. This paper describes the behavior of phase change materials that are inbuilt in aerated concrete blocks. Two building samples of an aerated concrete wall were measured in laboratory equipment called “twin-boxes”. The first box consists of a traditional aerated concrete wall; the second one has additional PCM micro-encapsulated in the wall. The heat flux through the wall was measured and compared to simulation results modeled in the ESP-r program. This experimental measurement provides a foundation for a model that can be used to analyze further building constructions.

  20. Using multi-shell phase change materials layers for cooling a lithium-ion battery

    Directory of Open Access Journals (Sweden)

    Nasehi Ramin

    2016-01-01

    Full Text Available One of the cooling methods in engineering systems is usage of phase change materials. Phase change materials or PCMs, which have high latent heats, are usually used where high energy absorption in a constant temperature is required. This work presents a numerical analysis of PCMs effects on cooling Li-ion batteries and their decrease in temperature levels during intense discharge. In this study, three PCM shells with different thermo-physical specifications located around a battery pack is examined. The results of each possible arrangement are compared together and the best arrangement leading to the lowest battery temperature during discharge is identified. In addition, the recovery time for the system which is the time required for the PCMs to refreeze is investigated.

  1. Feasibility of using phase change materials to control the heat of hydration in massive concrete structures.

    Science.gov (United States)

    Choi, Won-Chang; Khil, Bae-Soo; Chae, Young-Seok; Liang, Qi-Bo; Yun, Hyun-Do

    2014-01-01

    This paper presents experimental results that can be applied to select a possible phase change material (PCM), such as a latent heat material (LHM), to control the hydration heat in mass concrete structures. Five experimental tests (microconduction, simplified adiabatic temperature rise, heat, and compressive strength tests) were conducted to select the most desirable LHM out of seven types of inorganic PCM used in cement mortar and to determine the most suitable mix design. The results of these experimental tests were used to assess the feasibility of using PCM to reduce hydration heat in mass concrete that was examined. The experimental results show that cement mortar containing barium- [Ba(OH)2 · 8H2O] based PCM has the lowest amount of total hydration heat of the cement pastes. The barium-based PCM provides good latent heat properties that help to prevent volume change and microcracks caused by thermal stress in mass concrete.

  2. Feasibility of Using Phase Change Materials to Control the Heat of Hydration in Massive Concrete Structures

    Directory of Open Access Journals (Sweden)

    Won-Chang Choi

    2014-01-01

    Full Text Available This paper presents experimental results that can be applied to select a possible phase change material (PCM, such as a latent heat material (LHM, to control the hydration heat in mass concrete structures. Five experimental tests (microconduction, simplified adiabatic temperature rise, heat, and compressive strength tests were conducted to select the most desirable LHM out of seven types of inorganic PCM used in cement mortar and to determine the most suitable mix design. The results of these experimental tests were used to assess the feasibility of using PCM to reduce hydration heat in mass concrete that was examined. The experimental results show that cement mortar containing barium- [Ba(OH2·8H2O] based PCM has the lowest amount of total hydration heat of the cement pastes. The barium-based PCM provides good latent heat properties that help to prevent volume change and microcracks caused by thermal stress in mass concrete.

  3. Empirical Validation of a Thermal Model of a Complex Roof Including Phase Change Materials

    CERN Document Server

    Guichard, Stéphane; Bigot, Dimitri; Malet-Damour, Bruno; Libelle, Teddy; Boyer, Harry

    2015-01-01

    This paper deals with the empirical validation of a building thermal model using a phase change material (PCM) in a complex roof. A mathematical model dedicated to phase change materials based on the heat apparent capacity method was implemented in a multi-zone building simulation code, the aim being to increase understanding of the thermal behavior of the whole building with PCM technologies. To empirically validate the model, the methodology is based both on numerical and experimental studies. A parametric sensitivity analysis was performed and a set of parameters of the thermal model have been identified for optimization. The use of a generic optimization program called GenOpt coupled to the building simulation code enabled to determine the set of adequate parameters. We first present the empirical validation methodology and main results of previous work. We then give an overview of GenOpt and its coupling with the building simulation code. Finally, once the optimization results are obtained, comparisons o...

  4. Heat Transfer Modeling of Phase Change Materials in Multiple Plates Heat Exchanger

    Directory of Open Access Journals (Sweden)

    M. Alipanah

    2013-12-01

    Full Text Available Nowadays, given the increasing importance of energy sources, the possibility of energy storage in the heat exchangers through the Phase Change Materials (PCM and releasing it when needed have been extremely essential. This study seeks to model the domestic water heat system in which the paraffin is as the phase change material and it stores the solar energy. The behavior of a PCM plate was studied by writing the governing equations and solving them as the one-dimensional, implicit method and through numerical calculation of the method equations. Given the confirmed accuracy of performed modeling by the results of similar studies for the complete melting and solidification of PCM, the application of this system seems appropriate for the solar domestic water heaters.

  5. Effect of residual stresses and metallographic stability on the over all performance of integral diaphragm material

    Energy Technology Data Exchange (ETDEWEB)

    Sen, Geetha [Liquid Propulsion System Centre, ISRO, Bangalore 560 008 (India); Sampathkumaran, P., E-mail: psampathkumar29@yahoo.com [Materials Technology Division, Central Power Research Institute, Bangalore 560 080, Karnadaka (India); Nadig, D.S.; Manjunatha, R. [Centre for Cryogenic Technology, Indian Institute of Science, Bangalore 560 012 (India); Seetharamu, S. [Materials Technology Division, Central Power Research Institute, Bangalore 560 080, Karnadaka (India)

    2009-08-20

    The integral diaphragm pressure transducer consists of a diaphragm machined from precipitation hardened martensitic (APX4) steel. Its performance is quite significant as it depends upon various factors such as mechanical properties including induced residual stress levels, metallurgical and physical parameters due to different stages of processing involved. Hence, the measurement and analysis of residual stress becomes very important from the point of in-service assessment of a component. In the present work, the stress measurements have been done using the X-ray diffraction (XRD) technique, which is a non-destructive test (NDT). This method is more reliable and widely used compared to the other NDT techniques. The metallurgical aspects have been studied by adopting the conventional metallographic practices including examination of microstructure using light microscope. The dimensional measurements have been carried out using dimensional gauge. The results of the present investigation reveals that the diaphragm material after undergoing series of realization processes has yielded good amount of retained austenite in it. Also, the presence of higher compressive stresses induced in the transducer results in non-linearity, zero shift and dimensional instability. The problem of higher retained austenite content and higher compressive stress have been overcome by adopting a new realization process involving machining and cold and hot stabilization soak which has brought down the retained austenite content to about 5-6% and acceptable level of compressive stress in the range -100 to -150 MPa with fine tempered martensitic phase structure and good dimensional stability. The new realization process seems to be quite effective in terms of controlling retained austenite content, residual stress, metallurgical phase as well as dimensional stability and this may result in minimum zero shift of the diaphragm system.

  6. Teaching about Climate Change and Energy with Online Materials and Workshops from On the Cutting Edge

    Science.gov (United States)

    Kirk, K. B.; Manduca, C. A.; Myers, J. D.; Loxsom, F.

    2009-12-01

    Global climate change and energy use are among the most relevant and pressing issues in today’s science curriculum, yet they are also complex topics to teach. The underlying science spans multiple disciplines and is quickly evolving. Moreover, a comprehensive treatment of climate change and energy use must also delve into perspectives not typically addressed in geosciences courses, such as public policy and economics. Thus, faculty attempting to address these timely issues face many challenges. To support faculty in teaching these subjects, the On the Cutting Edge faculty development program has created a series of websites and workshop opportunities to provide faculty with information and resources for teaching about climate and energy. A web-based collection of teaching materials was developed in conjunction with the On the Cutting Edge workshops “Teaching about Energy in Geoscience Courses: Current Research and Pedagogy.” The website is designed to provide faculty with examples, references and ideas for either incorporating energy topics into existing geoscience courses or for designing or refining a course about energy. The website contains a collection of over 30 classroom and lab activities contributed by faculty and covering such diverse topics as renewable energy, energy policy and energy conservation. Course descriptions and syllabi for energy courses address audiences ranging from introductory courses to advanced seminars. Other materials available on the website include a collection of visualizations and animations, a catalog of recommended books, presentations and related references from the teaching energy workshops, and ideas for novel approaches or new topics for teaching about energy in the geosciences. The Teaching Climate Change website hosts large collections of teaching materials spanning many different topics within climate change, climatology and meteorology. Classroom activities highlight diverse pedagogic approaches such as role

  7. Microencapsulation of coco fatty acid mixture for thermal energy storage with phase change material

    Energy Technology Data Exchange (ETDEWEB)

    Ozonur, Y.; Mazman, M.; Paksoy, H.O.; Evilya, H. [Cukurova University, Adana (Turkey). Dept. of Chemistry

    2005-07-01

    Thermal energy storage systems provide several alternatives for efficient energy use and energy conservation. Microcapsules of natural coco fatty acid mixture were prepared to be used as phase change materials for thermal energy storage. The coacervation technique was used for the microencapsulation process. Several alternatives for the capsule wall material were tried. The microcapsules were characterized according to their geometric profiles, phase transition temperatures, mean particle sizes, chemical stabilities, and their thermal cycling. The diameters of microcapsules prepared in this study were about 1 mm. Coco fatty acid mixtures have kept their geometrical profiles even after 50 thermal cycles for melting and freezing operations in temperature range from 22 to 34{sup o}C. It was found that gelatin+gum Arabic mixture was the best wall material for microencapsulating coco fatty acid mixtures. (author)

  8. A numerical study of latent thermal energy storage in a phase change material/carbon panel

    Science.gov (United States)

    Mekaddem, Najoua; Ali, Samia Ben; Mazioud, Atef; Hannachi, Ahmed

    2016-07-01

    To reduce the energetic dependence of building, it has become necessary to explore and develop new materials promoting energy conservation. Because of their high storage capacity, phase change materials (PCMs) are efficient to store thermal energy. In this paper, a 3D model was studied for simulation of energy storing cycles to predict the performances of PCM loaded panels. Carbon was used as supporting material for the PCM. The simulation was based on the enthalpy method using Ansys Fluent software. The panel was exposed to a daily heat flow including the effects of convection and radiation. The results show that the temperature decreased of approximately 2.5°C with a time shift about 2 hours. The steady state was reached after four cycles. Thus, after four cycles the PCM showed its effects on the temperature conditioning.

  9. New methodology developed for the differential scanning calorimetry analysis of polymeric matrixes incorporating phase change materials

    Science.gov (United States)

    Barreneche, Camila; Solé, Aran; Miró, Laia; Martorell, Ingrid; Inés Fernández, A.; Cabeza, Luisa F.

    2012-08-01

    Nowadays, thermal comfort needs in buildings have led to an increase in energy consumption of the residential and service sectors. For this reason, thermal energy storage is shown as an alternative to achieve reduction of this high consumption. Phase change materials (PCM) have been studied to store energy due to their high storage capacity. A polymeric material capable of macroencapsulating PCM was developed by the authors of this paper. However, difficulties were found while measuring the thermal properties of these materials by differential scanning calorimetry (DSC). The polymeric matrix interferes in the detection of PCM properties by DSC. To remove this interfering effect, a new methodology which replaces the conventional empty crucible used as a reference in the DSC analysis by crucibles composed of the polymeric matrix was developed. Thus, a clear signal from the PCM is obtained by subtracting the new full crucible signal from the sample signal.

  10. Challenges in Integrated Computational Structure - Material Modeling of High Strain-Rate Deformation and Failure in Heterogeneous Materials

    Science.gov (United States)

    2014-10-09

    author(s) and should not contrued as an official Department of the Army position, policy or decision, unless so designated by other documentation . 9...Structure Heterogeneous Material Models REPORT DOCUMENTATION PAGE 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 10. SPONSOR/MONITOR’S ACRONYM(S) ARO 8...Bronkhorst of LANL . This was followed by a 30 min. panel discussion. (iv) Plenary session # 2 on Probabilistic Modeling & Uncertainty

  11. INTERFACIAL CRACK ANALYSIS IN THREE-DIMENSIONAL TRANSVERSELY ISOTROPIC BI-MATERIALS BY BOUNDARY INTEGRAL EQUATION METHOD

    Institute of Scientific and Technical Information of China (English)

    ZHAO Ming-hao; LI Dong-xia; SHEN Ya-peng

    2005-01-01

    The integral-differential equations for three-dimensional planar interfacial cracks of arbitrary shape in transversely isotropic bimaterials were derived by virtue of the Somigliana identity and the fundamental solutions, in which the displacement discontinuities across the crack faces are the unknowns to be determined. The interface is parallel to both the planes of isotropy. The singular behaviors of displacement and stress near the crack border were analyzed and the stress singularity indexes were obtained by integral equation method. The stress intensity factors were expressed in terms of the displacement discontinuities. In the non-oscillatory case, the hyper-singular boundary integral-differential equations were reduced to hyper-singular boundary integral equations similar to those of homogeneously isotropie materials.

  12. Changes in white matter integrity before conversion from mild cognitive impairment to Alzheimer's disease.

    Directory of Open Access Journals (Sweden)

    Michaela Defrancesco

    Full Text Available Mild cognitive impairment (MCI may represent an early stage of dementia conferring a particularly high annual risk of 15-20% of conversion to Alzheimer's disease (AD. Recent findings suggest that not only gray matter (GM loss but also a decline in white matter (WM integrity may be associated with imminent conversion from MCI to AD.In this study we used Voxel-based morphometry (VBM to examine if gray matter loss and/or an increase of the apparent diffusion coefficient (ADC reflecting mean diffusivity (MD are an early marker of conversion from MCI to AD in a high risk population.Retrospective neuropsychological and clinical data were collected for fifty-five subjects (MCI converters n = 13, MCI non-converters n = 14, healthy controls n = 28 at baseline and one follow-up visit. All participants underwent diffusion weighted imaging (DWI and T1-weighted structural magnetic resonance imaging scans at baseline to analyse changes in GM density and WM integrity using VBM.At baseline MCI converters showed impaired performance in verbal memory and naming compared to MCI non-converters. Further, MCI converters showed decreased WM integrity in the frontal, parietal, occipital, as well as the temporal lobe prior to conversion to AD. Multiple regression analysis showed a positive correlation of gray matter atrophy with specific neuropsychological test results.Our results suggest that additionally to morphological changes of GM a reduced integrity of WM indicates an imminent progression from MCI stage to AD. Therefore, we suggest that DWI is useful in the early diagnosis of AD.

  13. Field Testing of Low-Cost Bio-Based Phase Change Material

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Kaushik [ORNL; Childs, Phillip W [ORNL; Atchley, Jerald Allen [ORNL

    2013-03-01

    A test wall built with phase change material (PCM)-enhanced loose-fill cavity insulation was monitored for a period of about a year in the warm-humid climate of Charleston, South Carolina. The test wall was divided into various sections, one of which contained only loose-fill insulation and served as a control for comparing and evaluating the wall sections with the PCM-enhanced insulation. This report summarizes the findings of the field test.

  14. Water solar distiller productivity enhancement using concentrating solar water heater and phase change material (PCM)

    OpenAIRE

    Miqdam T. Chaichan; Hussein A. Kazem

    2015-01-01

    This paper investigates usage of thermal energy storage extracted from concentrating solar heater for water distillation. Paraffin wax selected as a suitable phase change material, and it was used for storing thermal energy in two different insulated treasurers. The paraffin wax is receiving hot water from concentrating solar dish. This solar energy stored in PCM as latent heat energy. Solar energy stored in a day time with a large quantity, and some heat retrieved for later use. Water’s temp...

  15. Development of equations for differential and integral enthalpy change of adsorption for simulation studies.

    Science.gov (United States)

    Do, D D; Nicholson, D; Fan, Chunyan

    2011-12-06

    We present equations to calculate the differential and integral enthalpy changes of adsorption for their use in Monte Carlo simulation. Adsorption of a system of N molecules, subject to an external potential energy, is viewed as one of transferring these molecules from a reference gas phase (state 1) to the adsorption system (state 2) at the same temperature and equilibrium pressure (same chemical potential). The excess amount adsorbed is the difference between N and the hypothetical amount of gas occupying the accessible volume of the system at the same density as the reference gas. The enthalpy change is a state function, which is defined as the difference between the enthalpies of state 2 and state 1, and the isosteric heat is defined as the negative of the derivative of this enthalpy change with respect to the excess amount of adsorption. It is suitable to determine how the system behaves for a differential increment in the excess phase adsorbed under subcritical conditions. For supercritical conditions, use of the integral enthalpy of adsorption per particle is recommended since the isosteric heat becomes infinite at the maximum excess concentration. With these unambiguous definitions we derive equations which are applicable for a general case of adsorption and demonstrate how they can be used in a Monte Carlo simulation. We apply the new equations to argon adsorption at various temperatures on a graphite surface to illustrate the need to use the correct equation to describe isosteric heat of adsorption.

  16. Direct observation of titanium-centered octahedra in titanium-antimony-tellurium phase-change material.

    Science.gov (United States)

    Rao, Feng; Song, Zhitang; Cheng, Yan; Liu, Xiaosong; Xia, Mengjiao; Li, Wei; Ding, Keyuan; Feng, Xuefei; Zhu, Min; Feng, Songlin

    2015-11-27

    Phase-change memory based on Ti0.4Sb2Te3 material has one order of magnitude faster Set speed and as low as one-fifth of the Reset energy compared with the conventional Ge2Sb2Te5 based device. However, the phase-transition mechanism of the Ti0.4Sb2Te3 material remains inconclusive due to the lack of direct experimental evidence. Here we report a direct atom-by-atom chemical identification of titanium-centered octahedra in crystalline Ti0.4Sb2Te3 material with a state-of-the-art atomic mapping technology. Further, by using soft X-ray absorption spectroscopy and density function theory simulations, we identify in amorphous Ti0.4Sb2Te3 the titanium atoms preferably maintain the octahedral configuration. Our work may pave the way to more thorough understanding and tailoring of the nature of the Ti-Sb-Te material, for promoting the development of dynamic random access memory-like phase-change memory as an emerging storage-class memory to reform current memory hierarchy.

  17. Examination of a Size-Change Test for Photovoltaic Encapsulation Materials (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Miller, D. C.; Ji, L.; Kelly, G.; Gu, X.; Nickel, N.; Norum, P.; Shioda, T.; Tamizhmani, G.; Wohlgemuth, J. H.

    2012-08-01

    We examine a proposed test standard that can be used to evaluate the maximum representative change in linear dimensions of sheet encapsulation products for photovoltaic modules (resulting from their thermal processing). The proposed protocol is part of a series of material-level tests being developed within Working Group 2 of the Technical Committee 82 of the International Electrotechnical Commission. The characterization tests are being developed to aid module design (by identifying the essential characteristics that should be communicated on a datasheet), quality control (via internal material acceptance and process control), and failure analysis. Discovery and interlaboratory experiments were used to select particular parameters for the size-change test. The choice of a sand substrate and aluminum carrier is explored relative to other options. The temperature uniformity of +/- 5C for the substrate was confirmed using thermography. Considerations related to the heating device (hot-plate or oven) are explored. The time duration of 5 minutes was identified from the time-series photographic characterization of material specimens (EVA, ionomer, PVB, TPO, and TPU). The test procedure was revised to account for observed effects of size and edges. The interlaboratory study identified typical size-change characteristics, and also verified the absolute reproducibility of +/- 5% between laboratories.

  18. Examination of a Size-Change Test for Photovoltaic Encapsulation Materials: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Miller, D. C.; Wohlgemuth, J. H.; Gu, X.; Ji, L.; Kelly, G.; Gu, X.; Nickel, N.; Norum, P.; Shioda, T.; Tamizhmani, G.

    2012-08-01

    We examine a proposed test standard that can be used to evaluate the maximum representative change in linear dimensions of sheet encapsulation products for photovoltaic modules (resulting from their thermal processing). The proposed protocol is part of a series of material-level tests being developed within Working Group 2 of the Technical Committee 82 of the International Electrotechnical Commission. The characterization tests are being developed to aid module design (by identifying the essential characteristics that should be communicated on a datasheet), quality control (via internal material acceptance and process control), and failure analysis. Discovery and interlaboratory experiments were used to select particular parameters for the size-change test. The choice of a sand substrate and aluminum carrier is explored relative to other options. The temperature uniformity of +/- 5C for the substrate was confirmed using thermography. Considerations related to the heating device (hot-plate or oven) are explored. The time duration of 5 minutes was identified from the time-series photographic characterization of material specimens (EVA, ionomer, PVB, TPO, and TPU). The test procedure was revised to account for observed effects of size and edges. The interlaboratory study identified typical size-change characteristics, and also verified the absolute reproducibility of +/- 5% between laboratories.

  19. Nanoengineered materials for liquid-vapour phase-change heat transfer

    Science.gov (United States)

    Cho, H. Jeremy; Preston, Daniel J.; Zhu, Yangying; Wang, Evelyn N.

    2016-12-01

    Liquid-vapour phase change is a useful and efficient process to transfer energy in nature, as well as in numerous domestic and industrial applications. Relatively recent advances in altering surface chemistry, and in the formation of micro- and nanoscale features on surfaces, have led to exciting improvements in liquid-vapour phase-change performance and better understanding of the underlying science. In this Review, we present an overview of the surface, thermal and material science to illustrate how new materials and designs can improve boiling and condensation. There are many parallels between boiling and condensation, such as nucleation of a phase and its departure from a surface; however, the particular set of challenges associated with each phenomenon results in different material designs used in different manners. We also discuss alternative techniques, such as introducing heterogeneous surface chemistry or direct real-time manipulation of the phase-change process, which can offer further control of heat-transfer processes. Finally, long-term robustness is essential to ensure reliability and feasibility but remains a key challenge.

  20. Evaluating the Contribution of Soil Carbon to Global Climate Change Mitigation in an Integrated Assessment

    Science.gov (United States)

    Thomson, A. M.; Izaurralde, R. C.; Clarke, L. E.

    2006-12-01

    Assessing the contribution of terrestrial carbon sequestration to national and international climate change mitigation requires integration across scientific and disciplinary boundaries. In a study for the US Climate Change Technology Program, site based measurements and geographic data were used to develop a three- pool, first-order kinetic model of global agricultural soil carbon (C) stock changes over 14 continental scale regions. This model was then used together with land use scenarios from the MiniCAM integrated assessment model in a global analysis of climate change mitigation options. MiniCAM evaluated mitigation strategies within a set of policy environments aimed at achieving atmospheric CO2 stabilization by 2100 under a suite of technology and development scenarios. Adoption of terrestrial sequestration practices is based on competition for land and economic markets for carbon. In the reference case with no climate policy, conversion of agricultural land from conventional cultivation to no tillage over the next century in the United States results in C sequestration of 7.6 to 59.8 Tg C yr-1, which doubles to 19.0 to 143.4 Tg C yr-1 under the most aggressive climate policy. Globally, with no carbon policy, agricultural C sequestration rates range from 75.2 to 18.2 Tg C yr-1 over the century, with the highest rates occurring in the first fifty years. Under the most aggressive global climate change policy, sequestration in agricultural soils reaches up to 190 Tg C yr-1 in the first 15 years. The contribution of agricultural soil C sequestration is a small fraction of the total global carbon offsets necessary to reach the stabilization targets (9 to 20 Gt C yr-1) by the end of the century. This integrated assessment provides decision makers with science-based estimates of the potential magnitude of terrestrial C sequestration relative to other greenhouse gas mitigation strategies in all sectors of the global economy. It also provides insight into the

  1. Climate Change Science Teaching through Integration of Technology in Instruction and Research

    Science.gov (United States)

    Sriharan, S.; Ozbay, G.; Robinson, L.; Klimkowski, V.

    2015-12-01

    This presentation demonstrates the importance of collaborations between the institutions with common focus on offering the academic program on climate change science. Virginia State University (VSU) developed and established the course on climate change and adaptation, AGRI 350 for undergraduates, in cooperation with two HBCUs, Delaware State University (DSU) and Morgan State University (MSU). This program was developed to enhance the science curriculum with funding from the USDA NIFA. The hands-on research opportunities for students were supported by the NSF HBCU UP Supplement Grant at VSU. The technical guidance and lesson plans were available through the courtesy of the AMS and faculty/student team training at the NCAR. In the initial stages, the faculty members participated in faculty development workshops hosted by the AMS and NCAR. This contributed to trained faculty members developing the courses on Climate Change at VSU, DSU, and MSU. To create awareness of global climate change and exposure of students to international programs, seven students from VSU, MSU, and DSU participated in the Climate Change course (ENS 320) at the University of Sunshine Coast (USC), Australia. This international experience included faculty members in using SimCLIM for climate change data into decision-making with regard to potential changes to cropping systems and tree growth. The Climate Change program at VSU, DSU, and MSU is emerging into comprehensive academic program which includes use of case studies and exchange of students' reflections with their peers through discussion board and videoconferencing, hands-on research on water quality monitoring and mapping the study sites, and integration of geospatial technologies and i-Tree. In addition, the students' engagement in intensive research was conducted through hands-on experience with Scanning Electron Microscopy in the Marine Science Department, University of Hawaii at Hilo in summer 2015.

  2. Proceedings of the 3rd World Congress on Integrated Computational Materials Engineering (ICME 2015). Held in Colorado Springs, CO on May 31-June 4, 2015

    Science.gov (United States)

    2016-06-28

    information , including suggestions for reducing the burden, to Department of Defense, Washington Headquarters Services , Directorate for Information ...modeling programs to p redict the behavior of materials and integrate this information into the overall materials design process. The 3rd World Congress...computer modeling programs to predict the ’behavior of materials and integrate this information into the overall materials design ·process. The 3rd

  3. Does Integration Help Adapt to Climate Change? Case of Increased US Corn Yield Volatility

    Science.gov (United States)

    Verma, M.; Diffenbaugh, N. S.; Hertel, T. W.

    2012-12-01

    In absence of of new crop varieties or significant shifts in the geography of corn production, US national corn yields variation could double by the year 2040 as a result of climate change and without adaptation this could lead the variability in US corn prices to quadruple (Diffenbaugh et al. 2012). In addition to climate induced price changes, analysis of recent commodity price spikes suggests that interventionist trade policies are partly to blame. Assuming we cannot much influence the future climate outcome, what policies can we undertake to adapt better? Can we use markets to blunt this edge? Diffenbaugh et al. find that sale of corn- ethanol for use in liquid fuel, when governed by quotas such as US Renewable Fuel Standard (RFS), could make US corn prices even more variable; in contrast the same food-fuel market link (we refer to it as intersectoral link) may well dampen price volatility when the sale of corn to ethanol industry is driven by higher future oil prices. The latter however comes at the cost of exposing corn prices to the greater volatility in oil markets. Similarly intervention in corn trade can make US corn prices less or more volatile by distorting international corn price transmission. A negative US corn yield shock shows that domestic corn supply falls and domestic prices to go up irrespective of whether or not markets are integrated. How much the prices go up depends on how much demand adjusts to accommodate the supply shock. Based on the forgoing analysis, one should expect that demand would adjust more readily when markets are integrated and therefore reduce the resulting price fluctuation. Simulation results confirm this response of corn markets. In terms of relative comparisons however a policy driven intersectoral integration is least effective and prices rise much more. Similarly, a positive world oil price shock makes the US oil imports expensive and with oil being used to produce gasoline blends, it increases the price of gasoline

  4. Integrating Land Change Science and Savanna Fire Models in West Africa

    Directory of Open Access Journals (Sweden)

    Paul Laris

    2013-11-01

    Full Text Available Fire is a key component of many land use systems and a determinant of land change. There is a growing concern that climate change will cause more catastrophic fires, but in many areas the impacts will be mediated by human land use practices. In African savannas, for example, fires are frequent and research finds low inter-annual variability in burned areas in places with highly variable rainfall. This regularity of fire suggests that African regimes are humanized, meaning that they are governed by human practices more than climate variation. Although these fire regimes are stable, they vary greatly over space. This paper will determine the reasons for two distinctly different fire regimes in Mali by integrating land change and savanna fire science. The study takes a two pronged approach to examine the causes of fire regimes and the reasons they change. It tests the notion that land cover (not land use governs fire regimes by combining long term burn scar and vegetation analysis with local interviews. Results indicate that efforts to link fire and land change science, need to focus more on subtle differences in land cover, landscape pattern and human practices, than on drought, land use or fire policy.

  5. Evaluation of Ablation rate by the change of Sacrificial Material for PECS in EU-APR

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Do Hyun; Kim, Yong Soo; Lee, Keun Sung [KHNP-CRI, Daejeon (Korea, Republic of)

    2015-05-15

    EU-APR, modified and improved from its original design of APR1400, has been developed to comply with European Utility Requirements (EUR) and nuclear design requirements of the European countries. In EU-APR, Severe Accident Mitigation Systems are dedicated to providing an independent defense line from that of Engineered Safety Feature (ESF) and Diverse Safety Feature (DSF). They consist of Emergency Reactor Depressurization System (ERDS), Passive Ex-vessel corium retaining and Cooling System (PECS), Severe Accident Containment Spray System (SACSS), Hydrogen Mitigation System (HMS) and Containment Filtered Vent System (CFVS). The PECS, so called core catcher, was introduced to prevent the Molten Core Concrete Interaction (MCCI) after Reactor Vessel (RV) failure. The PECS has experienced a lot of changes from its original design. Recently, the most significant change was that as a SM, limestone concrete is installed on PECS's body wall instead of previous sacrificial material rich in Fe{sub 2}O{sub 3}. The main reason of this design change is to overcome the issue that the sacrificial material is ablated rather too fast when reacting with corium that contains a large fraction of Zr metal. Other changes in the geometry of PECS's wall and downcomer design are considered as minor ones. In this paper, the comparison of ablation rates between previous SM and limestone concrete is carried out using MAAP5 code with respective MCCI model according to the material. In this paper, major improvements of MAAP5 model for PECS in EU-APR are presented and the evaluation of ablation rate for the previous SM model and the new LC model is carried out by means of ablation depths with LBLOCA sequence. Two models have respective unique ablation process. The ablation of LC model proceeds at a constant rate regardless of water while the ablation of SM model proceeds at a faster rate before the arrival of cooling water for corium and SM mixture. The change of sacrificial material

  6. The Integration of EIS parameters and bulk matrix characterization in studying reinforced cement-based materials

    NARCIS (Netherlands)

    Koleva, D.A.; Van Breugel, K.

    2012-01-01

    Corrosion in reinforced concrete is a major and costly concern, arising from the higher complexity of involved phenomena on different levels of material science (e.g. electrochemistry, concrete material science) and material properties (macro/micro/ nano). Reinforced cement-based systems (e.g. reinf

  7. The integration of eis parameters and bulk matrix characteristics in studying reinforced cement-based materials

    NARCIS (Netherlands)

    Koleva, D.A.; Van Breugel, K.

    2011-01-01

    Corrosion in reinforced concrete is a major and costly concern, arising from the higher complexity of involved phenomena on different levels of material science (e.g. electrochemistry, concrete material science) and material properties (macro/micro/ nano). Reinforced cement-based systems (e.g. reinf

  8. Thermal cycling test of few selected inorganic and organic phase change materials

    Energy Technology Data Exchange (ETDEWEB)

    Shukla, Anant; Sawhney, R.L. [Thermal Energy Storage Laboratory, School of Energy and Environmental Studies, Devi Ahilya University, Takshashila Campus, Indore 452001, M.P. (India); Buddhi, D. [Green Hi-Tech Energy Pvt. Ltd., Bari Brahmmana, Adda Sarore, Jammu 180011, Jammu and Kashmir (India)

    2008-12-15

    Thermal cycling tests were performed to check the stability in thermal energy storage systems on some selected organic and inorganic phase change materials (PCMs). The possibility of using these PCMs in thermal energy storage systems were examined on the basis of thermal, chemical and kinetic criteria. Organic and inorganic PCMs were selected to check their thermal stability. Inorganic PCMs were not found suitable after some cycles while thermal cycling for organic PCMs were undertaken up to 1000 thermal cycles and has shown a gradual change in melting temperature and latent heat of fusion. The PCMs were then checked with differential scanning calorimeter (DSC) for their latent heat storage capacity and melting temperature change. (author)

  9. Application of Heat Balance Integral Methods to One-Dimensional Phase Change Problems

    Directory of Open Access Journals (Sweden)

    S. L. Mitchell

    2012-01-01

    Full Text Available We employ the Heat Balance Integral Method (HBIM to solve a number of thermal and phase change problems which occur in a multitude of industrial contexts. As part of our analysis, we propose a new error measure for the HBIM that combines the least-squares error with a boundary immobilisation method. We describe how to determine this error for three basic thermal problems and show how it can be used to determine an optimal heat balance formulation. We then show how the HBIM, with the new error measure, may be used to approximate the solution of an aircraft deicing problem. Finally we apply the new method to two industrially important phase change problems.

  10. Influence of degenerative changes of intervertebral disc on its material properties and pathology

    Institute of Scientific and Technical Information of China (English)

    WANG Yi; CHEN Hai-bin; ZHANG Ling; ZHANG Li-ying; LIU Jing-cheng; WANG Zheng-guo

    2012-01-01

    Objective: To investigate the material properties of normal and degenerated intervertebral discs (IVDs) and examine the effect of degenerative changes on IVD pathology.Methods: A computer-based online search was undertaken to identify English articles about material properties of IVDs published from January 1950 to 2011 in PubMed database.The retrieved keywords included material properties,intervertebral disc and degeneration.Based on the principles of reliability,advancement and efficiency,the obtained data were primarily examined,and the original source was retrieved to read the full-text.Repetitive articles were excluded.The data of material properties of normal and degenerated IVDs were summarized and analyzed by meta-analysis.Results: The data of Young's modulus,Poisson's ratio,shear modulus,hydraulic permeability and intradiscal pressure of normal and degenerated IVDs were obtained.Compared with normal IVDs,the Young's modulus and shear modulus of annulus fibrosus and nucleus pulposus were higher in degenerated IVDs,the Poisson's ratio was lower while the hydraulic permeability and intradiscal pressure were higher.Besides,the degeneration-related alterations in IVDs had an influence both on itself and other spinal structures,leading to diseases such as bulging disc,discogenic pain and spinal stenosis.Meanwhile,the heavy mechanical loading and injury indicated important pathways to IVD degeneration.Conclusions: To a certain extent,the degenerative changes of IVD influence its material properties.And the degeneration-related alterations of composition can cause structural failure of IVDs,leading to injuries and diseases.

  11. An Integrated Systems Approach to Designing Climate Change Adaptation Policy in Water Resources

    Science.gov (United States)

    Ryu, D.; Malano, H. M.; Davidson, B.; George, B.

    2014-12-01

    Climate change projections are characterised by large uncertainties with rainfall variability being the key challenge in designing adaptation policies. Climate change adaptation in water resources shows all the typical characteristics of 'wicked' problems typified by cognitive uncertainty as new scientific knowledge becomes available, problem instability, knowledge imperfection and strategic uncertainty due to institutional changes that inevitably occur over time. Planning that is characterised by uncertainties and instability requires an approach that can accommodate flexibility and adaptive capacity for decision-making. An ability to take corrective measures in the event that scenarios and responses envisaged initially derive into forms at some future stage. We present an integrated-multidisciplinary and comprehensive framework designed to interface and inform science and decision making in the formulation of water resource management strategies to deal with climate change in the Musi Catchment of Andhra Pradesh, India. At the core of this framework is a dialogue between stakeholders, decision makers and scientists to define a set of plausible responses to an ensemble of climate change scenarios derived from global climate modelling. The modelling framework used to evaluate the resulting combination of climate scenarios and adaptation responses includes the surface and groundwater assessment models (SWAT & MODFLOW) and the water allocation modelling (REALM) to determine the water security of each adaptation strategy. Three climate scenarios extracted from downscaled climate models were selected for evaluation together with four agreed responses—changing cropping patterns, increasing watershed development, changing the volume of groundwater extraction and improving irrigation efficiency. Water security in this context is represented by the combination of level of water availability and its associated security of supply for three economic activities (agriculture

  12. Age-related changes in the integration of gaze direction and facial expressions of emotion.

    Science.gov (United States)

    Slessor, Gillian; Phillips, Louise H; Bull, Rebecca

    2010-08-01

    Gaze direction influences younger adults' perception of emotional expressions, with direct gaze enhancing the perception of anger and joy, while averted gaze enhances the perception of fear. Age-related declines in emotion recognition and eye-gaze processing have been reported, indicating that there may be age-related changes in the ability to integrate these facial cues. As there is evidence of a positivity bias with age, age-related difficulties integrating these cues may be greatest for negative emotions. The present research investigated age differences in the extent to which gaze direction influenced explicit perception (e.g., anger, fear and joy; Study 1) and social judgments (e.g., of approachability; Study 2) of emotion faces. Gaze direction did not influence the perception of fear in either age group. In both studies, age differences were found in the extent to which gaze direction influenced judgments of angry and joyful faces, with older adults showing less integration of gaze and emotion cues than younger adults. Age differences were greatest when interpreting angry expressions. Implications of these findings for older adults' social functioning are discussed.

  13. The changing paradigm for integrated simulation in support of Command and Control (C2)

    Science.gov (United States)

    Riecken, Mark; Hieb, Michael

    2016-05-01

    Modern software and network technologies are on the verge of enabling what has eluded the simulation and operational communities for more than two decades, truly integrating simulation functionality into operational Command and Control (C2) capabilities. This deep integration will benefit multiple stakeholder communities from experimentation and test to training by providing predictive and advanced analytics. There is a new opportunity to support operations with simulation once a deep integration is achieved. While it is true that doctrinal and acquisition issues remain to be addressed, nonetheless it is increasingly obvious that few technical barriers persist. How will this change the way in which common simulation and operational data is stored and accessed? As the Services move towards single networks, will there be technical and policy issues associated with sharing those operational networks with simulation data, even if the simulation data is operational in nature (e.g., associated with planning)? How will data models that have traditionally been simulation only be merged in with operational data models? How will the issues of trust be addressed?

  14. Integrated assessment of climate change impact on surface runoff contamination by pesticides.

    Science.gov (United States)

    Gagnon, Patrick; Sheedy, Claudia; Rousseau, Alain N; Bourgeois, Gaétan; Chouinard, Gérald

    2016-07-01

    Pesticide transport by surface runoff depends on climate, agricultural practices, topography, soil characteristics, crop type, and pest phenology. To accurately assess the impact of climate change, these factors must be accounted for in a single framework by integrating their interaction and uncertainty. This article presents the development and application of a framework to assess the impact of climate change on pesticide transport by surface runoff in southern Québec (Canada) for the 1981-2040 period. The crop enemies investigated were: weeds for corn (Zea mays); and for apple orchard (Malus pumila), 3 insect pests (codling moth [Cydia pomonella], plum curculio [Conotrachelus nenuphar], and apple maggot [Rhagoletis pomonella]), 2 diseases (apple scab [Venturia inaequalis], and fire blight [Erwinia amylovora]). A total of 23 climate simulations, 19 sites, and 11 active ingredients were considered. The relationship between climate and phenology was accounted for by bioclimatic models of the Computer Centre for Agricultural Pest Forecasting (CIPRA) software. Exported loads of pesticides were evaluated at the edge-of-field scale using the Pesticide Root Zone Model (PRZM), simulating both hydrology and chemical transport. A stochastic model was developed to account for PRZM parameter uncertainty. Results of this study indicate that for the 2011-2040 period, application dates would be advanced from 3 to 7 days on average with respect to the 1981-2010 period. However, the impact of climate change on maximum daily rainfall during the application window is not statistically significant, mainly due to the high variability of extreme rainfall events. Hence, for the studied sites and crop enemies considered, climate change impact on pesticide transported in surface runoff is not statistically significant throughout the 2011-2040 period. Integr Environ Assess Managem 2016;12:559-571. © Her Majesty the Queen in Right of Canada 2015; Published 2015 SETAC.

  15. Numerical Study of Thermal Performance of Phase Change Material Energy Storage Floor in Solar Water Heating System

    Institute of Scientific and Technical Information of China (English)

    ZENG Ruo-lang; WANG Xin; ZHANG Yin-ping; DI Hong-fa; ZHANG Qun-li

    2009-01-01

    The conventional solar heating floor system contains a big water tank to store energy in the day time for heating at night,which takes much building space and is very heavy.In order to reduce the water tank velume even to cancel the tank,a novel structure of integrated water pipe floor heating system using shape-stabi-lized phase change materials (SSPCM) for thermal energy storage was developed.A numerical model was devel-oped to analyze the performance of SSPCM floor heating system under the intermittent heating condition,which was verified by our experimental data.The thermal performance of the heating system and the effects of various factors on it were analyzed numerically.The factors including phase transition temperature,heat of fusion,ther-real conductivity of SSPCM and thermal conductivity of the decoration material were analyzed.The results show that tm and kd are the most import influencing factors on the thermal performance of SSPCM floor heating sys-tem,since they determine the heat source temperature and thermal resistance between SSPCM plates and indoor air,respectively.Hm should be large to store enough thermal energy in the day time for nighttimes heating.The effects of KP can be ignored in this system.The SSPCM floor heating system has potential of making use of the daytime solar energy for heating at night efficiently in various climates when its structure is properly designed.

  16. Process Simulation Role in the Development of New Alloys Based on Integrated Computational Material Science and Engineering

    Energy Technology Data Exchange (ETDEWEB)

    Sabau, Adrian S [ORNL; Porter, Wallace D [ORNL; Roy, Shibayan [ORNL; Shyam, Amit [ORNL

    2014-01-01

    To accelerate the introduction of new materials and components, the development of metal casting processes requires the teaming between different disciplines, as multi-physical phenomena have to be considered simultaneously for the process design and optimization of mechanical properties. The required models for physical phenomena as well as their validation status for metal casting are reviewed. The data on materials properties, model validation, and relevant microstructure for materials properties are highlighted. One vehicle to accelerate the development of new materials is through combined experimental-computational efforts. Integrated computational/experimental practices are reviewed; strengths and weaknesses are identified with respect to metal casting processes. Specifically, the examples are given for the knowledge base established at Oak Ridge National Laboratory and computer models for predicting casting defects and microstructure distribution in aluminum alloy components.

  17. High resistivity iron-based, thermally stable magnetic material for on-chip integrated inductors

    Energy Technology Data Exchange (ETDEWEB)

    Deligianni, Hariklia; Gallagher, William J.; Mason, Maurice; O' Sullivan, Eugene J.; Romankiw, Lubomyr T.; Wang, Naigang

    2017-03-07

    An on-chip magnetic structure includes a palladium activated seed layer and a substantially amorphous magnetic material disposed onto the palladium activated seed layer. The substantially amorphous magnetic material includes nickel in a range from about 50 to about 80 atomic % (at. %) based on the total number of atoms of the magnetic material, iron in a range from about 10 to about 50 at. % based on the total number of atoms of the magnetic material, and phosphorous in a range from about 0.1 to about 30 at. % based on the total number of atoms of the magnetic material. The magnetic material can include boron in a range from about 0.1 to about 5 at. % based on the total number of atoms of the magnetic material.

  18. Numerical Model and Analysis of Peak Temperature Reduction in LiFePO4 Battery Packs Using Phase Change Materials

    DEFF Research Database (Denmark)

    Coman, Paul Tiberiu; Veje, Christian

    2013-01-01

    Numerical model and analysis of peak temperature reduction in LiFePO4 battery packs using phase change materials......Numerical model and analysis of peak temperature reduction in LiFePO4 battery packs using phase change materials...

  19. Integrated waste management as a climate change stabilisation wedge for the Maltese islands.

    Science.gov (United States)

    Falzon, Clyde; Fabri, Simon G; Frysinger, Steven

    2013-01-01

    The continuous increase in anthropogenic greenhouse gas emissions occurring since the Industrial Revolution is offering significant ecological challenges to Earth. These emissions are leading to climate changes which bring about extensive damage to communities, ecosystems and resources. The analysis in this article is focussed on the waste sector within the Maltese islands, which is the largest greenhouse gas emitter in the archipelago following the energy and transportation sectors. This work shows how integrated waste management, based on a life cycle assessment methodology, acts as an effective stabilisation wedge strategy for climate change. Ten different scenarios applicable to the Maltese municipal solid waste management sector are analysed. It is shown that the scenario that is most coherent with the stabilisation wedges strategy for the Maltese islands consists of 50% landfilling, 30% mechanical biological treatment and 20% recyclable waste export for recycling. It is calculated that 16.6 Mt less CO2-e gases would be emitted over 50 years by means of this integrated waste management stabilisation wedge when compared to the business-as-usual scenario. These scientific results provide evidence in support of policy development in Malta that is implemented through legislation, economic instruments and other applicable tools.

  20. Inline calculation tool for the determination of the changeover time for color and material changes in polymer processing

    Science.gov (United States)

    Burgfeld, Michael; Wortberg, Johannes

    2016-03-01

    A change of extruded plastic products into a different material or color is connected to a wasteful process, regarding the loss of material, energy and system availability. Because of this, plastic processing companies want to reduce the required time between the basic and the target product. In the extrusion processes there are two possibilities to change from one material to another. The first option is the manual cleaning of the extruder and extrusion die, which leads to with a production stop and a high personnel effort. The second option is to perform a direct material or color change. The disadvantage of this method are the produced rejects during the change. Further, it is difficult to detect the end of the changing process, based on the product color, without expert knowledge. The LabVIEW inline calculation tool allows to detect the progress of the material change dynamically and to predict the needed time to reach the end of the changing process. Therefore an inline color measurement system ACS 7000 by μEpsilon is used to analyze the continuous change of color of the extrudate. The color information is converted into the numerical L*a*b* -color system and is compared to reference data, which are stored in a material database for different target materials and/or colors. The result of this comparison can be expressed as so-called color distance ΔE, which is necessary to determine the end of the changing process. With increasing changing time, the color distance is decreasing. After reaching a specified color distance ΔE a difference between the extrudate color and the target color is not detectable for the human eye anymore. The color change is finished. By analyzing the measured color changing progress, the tool is also able to predict the needed changing time. The functional capability of the tool is proved by a color change experiment from blue to natural material on a laboratory extruder

  1. Review of the use of phase change materials (PCMs in buildings with reinforced concrete structures

    Directory of Open Access Journals (Sweden)

    Pons, O.

    2014-09-01

    Full Text Available Phase change materials are capable of storing and releasing energy in the form of heat in determined temperature ranges, so to increase a building’s thermal inertia, stabilize its indoor temperatures and reduce its energetic demand. Therefore, if we used these materials we could have more energetically efficient buildings. Nevertheless, are these materials most appropriate to be used in buildings? Could the incorporation of phase change materials in buildings with concrete structures be generalized? This article aims to carry out a review of these phase change materials from construction professionals’ points of view, study their applications for buildings with reinforced concrete structures and the key points for these applications, draw conclusions and provide recommendations useful for all professionals within the sector who are considering the application of these materials.Los materiales de cambio de fase son capaces de almacenar y liberar energía en forma de calor en un determinando rango de temperaturas, y así aumentar la inercia térmica de un edificio, estabilizar las temperaturas en el interior y reducir la demanda energética. En consecuencia, si utilizáramos estos materiales podríamos tener un parque de edificios más eficientes energéticamente. No obstante, ¿estos materiales son apropiados para usarse en edificios? ¿Se podría generalizar la incorporación de materiales de cambio de fase en edificios con estructuras de hormigón? Este artículo tiene como objetivos hacer una revisión del estado del arte de estos materiales de cambio de fase desde el punto de vista de los profesionales de la construcción, estudiar las aplicaciones en edificios con estructuras de hormigón armado y los puntos clave para estas aplicaciones, extraer conclusiones y recomendaciones útiles para los profesionales del sector que se planteen la utilización de estos materiales.

  2. Novel solid – solid phase change material based on polyethylene glycol and cellulose used for temperature stabilisation

    Directory of Open Access Journals (Sweden)

    Wojda Marta

    2014-01-01

    Full Text Available Thermal management is one of crucial issues in the development of modern electronic devices. In the recent years interest in phase change materials (PCMs as alternative cooling possibility has increased significantly. Preliminary results concerning the research into possibility of the use of solid-solid phase change materials (S-S PCMs for stabilisation temperature of electronic devices has been presented in the paper. Novel solid-solid phase change material based on polyethylene glycol and cellulose has been synthesized. Attempt to improve its thermal conductivity has been taken. Material has been synthesized for the purpose of stabilisation of temperature of electronic devices.

  3. An integrated model to simulate sown area changes for major crops at a global scale

    Institute of Scientific and Technical Information of China (English)

    WU WenBin; YANG Peng; MENG ChaoYing; SHIBASAKI Ryosuke; ZHOU QingBo; TANG HuaJun; SHI Yun

    2008-01-01

    Dynamics of land use systems have attracted much attention from scientists around the world due to their ecological and socio-economic implications. An integrated model to dynamically simulate future changes in sown areas of four major crops (rice, maize, wheat and soybean) on a global scale is presented. To do so, a crop choice model was developed on the basis of Multinomial Logit (Logit) model to model land users' decisions on crop choices among a set of available alternatives with using a crop utility function. A GIS-based Environmental Policy Integrated Climate (EPIC) model was adopted to simulate the crop yields under a given geophysical environment and farming management conditions,while the International Food Policy and Agricultural Simulation (IFPSIM) model was utilized to estimate crop price in the international market. The crop choice model was linked with the GIS-based EPIC model and the IFPSIM model through data exchange. This integrated model was then validated against the FAO statistical data in 2001-2003 and the Moderate Resolution Imaging Spectroradiometer (MODIS)global land cover product in 2001. Both validation approaches indicated reliability of the model for addressing the dynamics in agricultural land use and its capability for long-term scenario analysis. Finally,the model application was designed to run over a time period of 30 a, taking the year 2000 as baseline.The model outcomes can help understand and explain the causes, locations and consequences of land use changes, and provide support for land use planning and policy making.

  4. A review on phase-change materials: Mathematical modeling and simulations

    Energy Technology Data Exchange (ETDEWEB)

    Dutil, Yvan; Rousse, Daniel R. [Chaire de Recherche Industrielle T3E, Ecole de technologie superieure, Universite du Quebec, 801 Boul. Mgr, Bourget Levis, QC G6V 9V6 (Canada); Salah, Nizar Ben [Laboratoire MMP, Ecole Superieure des Sciences et Techniques de Tunis, 5 Avenue Taha Hussein, BP 56, Bab Manara, Tunis (Tunisia); Lassue, Stephane; Zalewski, Laurent [LAMTI, Faculte des sciences appliquees, Universite d' Artois, Technoparc Futura, 62400 Bethune (France)

    2011-01-15

    Energy storage components improve the energy efficiency of systems by reducing the mismatch between supply and demand. For this purpose, phase-change materials are particularly attractive since they provide a high-energy storage density at a constant temperature which corresponds to the phase transition temperature of the material. Nevertheless, the incorporation of phase-change materials (PCMs) in a particular application calls for an analysis that will enable the researcher to optimize performances of systems. Due to the non-linear nature of the problem, numerical analysis is generally required to obtain appropriate solutions for the thermal behavior of systems. Therefore, a large amount of research has been carried out on PCMs behavior predictions. The review will present models based on the first law and on the second law of thermodynamics. It shows selected results for several configurations, from numerous authors so as to enable one to start his/her research with an exhaustive overview of the subject. This overview stresses the need to match experimental investigations with recent numerical analyses since in recent years, models mostly rely on other models in their validation stages. (author)

  5. Experimental and Numerical Investigations of Thermal Ignition of a Phase Changing Energetic Material

    Directory of Open Access Journals (Sweden)

    Priyanka Shukla

    2016-04-01

    Full Text Available Fortuitous exposure to high temperatures initiates reaction in energetic materials and possibilities of such event are of great concern in terms of the safe and controlled usage of explosive devices. Experimental and numerical investigations on time to explosion and location of ignition of a phase changing polymer bonded explosive material (80 per cent RDX and 20 per cent binder, contained in a metallic confinement subjected to controlled temperature build-up on its surface, are presented. An experimental setup was developed in which the polymer bonded explosive material filled in a cylindrical confinement was provided with a precise control of surface heating rate. Temperature at various radial locations was monitored till ignition. A computational model for solving two dimensional unsteady heat transfer with phase change and heat generation due to multi-step chemical reaction was developed. This model was implemented using a custom field function in the framework of a finite volume method based standard commercial solver. Numerical study could simulate the transient heat conduction, the melting pattern of the explosive within the charge and also the thermal runaway. Computed values of temperature evolution at various radial locations and the time to ignition were closely agreeing with those measured in experiment. Results are helpful both in predicting the possibility of thermal ignition during accidents as well as for the design of safety systems.

  6. Geopolymer encapsulation of a chloride salt phase change material for high temperature thermal energy storage

    Science.gov (United States)

    Jacob, Rhys; Trout, Neil; Raud, Ralf; Clarke, Stephen; Steinberg, Theodore A.; Saman, Wasim; Bruno, Frank

    2016-05-01

    In an effort to reduce the cost and increase the material compatibility of encapsulated phase change materials (EPCMs) a new encapsulated system has been proposed. In the current study a molten salt eutectic of barium chloride (53% wt.), potassium chloride (28% wt.) and sodium chloride (19% wt.) has been identified as a promising candidate for low cost EPCM storage systems. The latent heat, melting point and thermal stability of the phase change material (PCM) was determined by DSC and was found to be in good agreement with results published in the literature. To cope with the corrosive nature of the PCM, it was decided that a fly-ash based geopolymer met the thermal and economic constraints for encapsulation. The thermal stability of the geopolymer shell was also tested with several formulations proving to form a stable shell for the chosen PCM at 200°C and/or 600°C. Lastly several capsules of the geopolymer shell with a chloride PCM were fabricated using a variety of methods with several samples remaining stable after exposure to 600°C testing.

  7. High-Temperature Phase Change Materials (PCM) Candidates for Thermal Energy Storage (TES) Applications

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, J. C.

    2011-09-01

    It is clearly understood that lower overall costs are a key factor to make renewable energy technologies competitive with traditional energy sources. Energy storage technology is one path to increase the value and reduce the cost of all renewable energy supplies. Concentrating solar power (CSP) technologies have the ability to dispatch electrical output to match peak demand periods by employing thermal energy storage (TES). Energy storage technologies require efficient materials with high energy density. Latent heat TES systems using phase change material (PCM) are useful because of their ability to charge and discharge a large amount of heat from a small mass at constant temperature during a phase transformation like melting-solidification. PCM technology relies on the energy absorption/liberation of the latent heat during a physical transformation. The main objective of this report is to provide an assessment of molten salts and metallic alloys proposed as candidate PCMs for TES applications, particularly in solar parabolic trough electrical power plants at a temperature range from 300..deg..C to 500..deg.. C. The physical properties most relevant for PCMs service were reviewed from the candidate selection list. Some of the PCM candidates were characterized for: chemical stability with some container materials; phase change transformation temperatures; and latent heats.

  8. Visualization of IOL Material-Induced Changes in Retinal Color Stimulus

    Directory of Open Access Journals (Sweden)

    Stephan Reiss

    2016-01-01

    Full Text Available Purpose. Different IOL materials, particularly blue-light filtering materials, have different spectral transmittance characteristics. The color stimuli, which influence retinal receptors objectively, have consequently implications for color perception. We report on the quantitative determination of IOL-specific transmittance characteristics and present a method visualizing the resultant changes in color stimulus. Methods. A setup was realized to quantify IOL-absorption in a range of 390–780 nm. To visualize the influence of the different spectral transmittance characteristics an algorithm was developed, which converts RGB-pixel values of images into spectra, which performs the corresponding transmittance correction, reconverts to RGB, and reconstructs the image. IOLs of hydrophobic acrylate and hydrophilic acrylate with a hydrophobic surface in each case with/without blue-light filter were examined. Results. Assessment of the reference images verifies the suitability of the pipeline. Evaluation of the transmittance spectra reveals differences of material- and manufacturer-specifics, which are capable of inducing considerable changes in color perception, particularly in the blue color range and mixed colors involving blue. Conclusions. The developed technique provides an approach for determining IOL-specific transmittance behavior and subsequently its influence on the retinal color stimulus. Problems of altered color perception are occasionally reported after cataract surgery and these become obvious with the visualization procedure developed here.

  9. High-field electrical transport in amorphous phase-change materials

    Science.gov (United States)

    Kaes, Matthias; Le Gallo, Manuel; Sebastian, Abu; Salinga, Martin; Krebs, Daniel

    2015-10-01

    Electrical transport in chalcogenide-based phase change materials is an active area of research owing to the prominent role played by these materials in the field of information technology. Here, we present transport measurements (IV curves) obtained on line-cells of as-deposited amorphous phase change materials (Ge2Sb2Te5, GeTe, Ag4In3Sb66Te27) over a wide voltage and temperature range (300 K to 160 K). The well defined geometry of our devices enables a description of the transport behavior in terms of conductivity vs. electric field. At higher temperatures (300 K ≥ T ≥ 220 K) and low to intermediate fields (F Poole-Frenkel emission from a two-center Coulomb potential. Based on this model, we observe a temperature dependence of the inter-trap distance, which we can relate to a temperature dependence in the occupation of the defect creating the Coulomb potential governing Poole-Frenkel emission. At higher fields and lower temperatures, the dependency of the IV curve on the electric field can be described by ln(I/I0) = (F/Fc)2. By combining this contribution with that of the Poole-Frenkel emission, we can show that the slope at high fields, Fc, is independent of temperature. We argue that models based on direct tunneling or thermally assisted tunneling from a single defect into the valence band cannot explain the observed behavior quantitatively.

  10. Earth science information: Planning for the integration and use of global change information

    Science.gov (United States)

    Lousma, Jack R.

    1992-01-01

    The Consortium for International Earth Science Information Network (CIESIN) was founded in 1989 as a non-profit corporation dedicated to facilitating access to, use and understanding of global change information worldwide. The Consortium was created to cooperate and coordinate with organizations and researchers throughout the global change community to further access the most advanced technology, the latest scientific research, and the best information available for critical environmental decision making. CIESIN study efforts are guided by Congressional mandates to 'convene key present and potential users to assess the need for investment in integration of earth science information,' to 'outline the desirable pattern of interaction with the scientific and policy community,' and to 'develop recommendations and draft plans to achieve the appropriate level of effort in the use of earth science data for research and public policy purposes.' In addition, CIESIN is tasked by NASA to develop a data center that would extend the benefits of Earth Observing System (EOS) to the users of global change information related to human dimensions issues. For FY 1991, CIESIN focused on two main objectives. The first addressed the identification of information needs of global change research and non-research user groups worldwide. The second focused on an evaluation of the most efficient mechanisms for making this information available in usable forms.

  11. Integrating Climate Change Resilience Features into the Incremental Refinement of an Existing Marine Park

    Science.gov (United States)

    Beckley, Lynnath E.; Kobryn, Halina T.; Lombard, Amanda T.; Radford, Ben; Heyward, Andrew

    2016-01-01

    Marine protected area (MPA) designs are likely to require iterative refinement as new knowledge is gained. In particular, there is an increasing need to consider the effects of climate change, especially the ability of ecosystems to resist and/or recover from climate-related disturbances, within the MPA planning process. However, there has been limited research addressing the incorporation of climate change resilience into MPA design. This study used Marxan conservation planning software with fine-scale shallow water (<20 m) bathymetry and habitat maps, models of major benthic communities for deeper water, and comprehensive human use information from Ningaloo Marine Park in Western Australia to identify climate change resilience features to integrate into the incremental refinement of the marine park. The study assessed the representation of benthic habitats within the current marine park zones, identified priority areas of high resilience for inclusion within no-take zones and examined if any iterative refinements to the current no-take zones are necessary. Of the 65 habitat classes, 16 did not meet representation targets within the current no-take zones, most of which were in deeper offshore waters. These deeper areas also demonstrated the highest resilience values and, as such, Marxan outputs suggested minor increases to the current no-take zones in the deeper offshore areas. This work demonstrates that inclusion of fine-scale climate change resilience features within the design process for MPAs is feasible, and can be applied to future marine spatial planning practices globally. PMID:27529820

  12. Towards an integrated economic assessment of climate change impacts on agriculture

    Science.gov (United States)

    Lotze-Campen, H.; Piontek, F.; Stevanovic, M.; Popp, A.; Bauer, N.; Dietrich, J.; Mueller, C.; Schmitz, C.

    2012-12-01

    For a detailed understanding of the effects of climate change on global agricultural production systems, it is essential to consider the variability of climate change patterns as projected by General Circulation Models (GCMs), their bio-physical impact on crops and the response in land-use patterns and markets. So far, approaches that account for the interaction of bio-physical and economic impacts are largely lacking. We present an integrative analysis by using a soft-coupled system of a biophysical impact model (LPJmL, Bondeau et al. 2007), an economically driven land use model (MAgPIE, Lotze-Campen et al. 2008) and an integrated assessment model (ReMIND-R, Leimbach et al. 2010) to study climate change impacts and economic damages in the agricultural sector. First, the dynamic global vegetation and hydrology model LPJmL is used to derive climate change impacts on crop yields for wheat, maize, soy, rice and other major crops. A range of different climate projections is used, taken from the dataset provided by the Intersectoral Impact Model Intercomparison Project (ISI-MIP, www.isi-mip.org), which bias-corrected the latest CMIP5 climate data (Taylor et al. 2011). Crop yield impacts cover scenarios with and without CO2 fertilization as well as different Representative Concentration Pathways (RCPs) and different GCMs. With increasing temperature towards the end of the century yields generally decrease in tropical and subtropical regions, while they tend to benefit in higher latitudes. LPJmL results have been compared to other global crop models in the Agricultural Model Intercomparison and Improvement Project (AgMIP, www.agmip.org). Second, changes in crop yields are analysed with the spatially explicit agro-economic model MAgPIE, which covers their interaction with economic development and changes in food demand. Changes in prices as well as welfare changes of producer and consumer surplus are taken as economic indicators. Due to climate-change related reductions in

  13. Discuss on Material Integrative Management%对物资一体化管理的探讨

    Institute of Scientific and Technical Information of China (English)

    王小兵

    2011-01-01

    Promote material integrative management, organizational structure, business process, management system, technical standard, performance standard, indexes system and information system. Implement " two -stage" materials purchasing and enhance the managemen%推进物资一体化管理、组织架构、业务流程、管理制度、技术标准、作业标准、指标体系、信息系统。实施“两级”物资采购,加强合同履约管理和逆向物流管理。

  14. Integrated Aerodynamic/Structural/Dynamic Analyses of Aircraft with Large Shape Changes

    Science.gov (United States)

    Samareh, Jamshid A.; Chwalowski, Pawel; Horta, Lucas G.; Piatak, David J.; McGowan, Anna-Maria R.

    2007-01-01

    The conceptual and preliminary design processes for aircraft with large shape changes are generally difficult and time-consuming, and the processes are often customized for a specific shape change concept to streamline the vehicle design effort. Accordingly, several existing reports show excellent results of assessing a particular shape change concept or perturbations of a concept. The goal of the current effort was to develop a multidisciplinary analysis tool and process that would enable an aircraft designer to assess several very different morphing concepts early in the design phase and yet obtain second-order performance results so that design decisions can be made with better confidence. The approach uses an efficient parametric model formulation that allows automatic model generation for systems undergoing radical shape changes as a function of aerodynamic parameters, geometry parameters, and shape change parameters. In contrast to other more self-contained approaches, the approach utilizes off-the-shelf analysis modules to reduce development time and to make it accessible to many users. Because the analysis is loosely coupled, discipline modules like a multibody code can be easily swapped for other modules with similar capabilities. One of the advantages of this loosely coupled system is the ability to use the medium-to high-fidelity tools early in the design stages when the information can significantly influence and improve overall vehicle design. Data transfer among the analysis modules are based on an accurate and automated general purpose data transfer tool. In general, setup time for the integrated system presented in this paper is 2-4 days for simple shape change concepts and 1-2 weeks for more mechanically complicated concepts. Some of the key elements briefly described in the paper include parametric model development, aerodynamic database generation, multibody analysis, and the required software modules as well as examples for a telescoping wing, a

  15. Consequences of stratospheric ozone depletion and climate change on the use of materials.

    Science.gov (United States)

    Andrady, A L; Torikai, A; Redhwi, H H; Pandey, K K; Gies, P

    2015-01-01

    Materials used in the exterior of buildings and in construction are routinely exposed to solar UV radiation. Especially in the case of wood and plastic building materials, the service life is determined by their weather-induced deterioration. Any further increase in ground-level solar UV radiation, UV-B radiation in particular, will therefore reduce the outdoor service life of these products. Any increase in ambient temperature due to climate change will also have the same effect. However, the existing light-stabilizer technologies are likely to be able to mitigate the additional damaging effects due to increased solar UV radiation and maintain the outdoor lifetimes of these materials at the present levels. These mitigation choices invariably increase the lifetime cost of these products. A reliable estimate of what this additional cost might be for different products is not available at the present time. Personal exposure to UV radiation is reduced both by clothing fabrics and glass windows used in buildings and automobiles. This assessment describes how the recent technical advances in degradation and stabilization techniques impact the lifetimes of plastics and wood products routinely exposed to solar UV radiation and the protection to humans offered by materials against solar UV radiation.

  16. Preparation of shape-stabilized phase change materials as temperature-adjusting powder

    Institute of Scientific and Technical Information of China (English)

    MIAO Chunyan; L(U) Gang; YAO Youwei; TANG Guoyi; WENG Duan

    2007-01-01

    The shape-stabilized phase change materials (PCMs)composed of paraffin wax and silica were prepared in O/W emulsion with cetyl trimethylamine bromide as emulsifier and n-pentanol as assist emulsifier.The paraffin wax(with melting temperature of 29℃,crystallizing temperature of 26℃ and latent heat of 142 J/g)served as latent heat storage material and the silica as supporting material,which prevented the leakage of the melted paraffin wax.Silica supporting material was formed in situ via hydrolysis and condensation from low-cost sodium silicate solution with chlorhydric acid and ammonium bicarbonate as neutralizing agent.The thermogravimetry(TG)curves show that the composite has a thermal stability superior to that of paraffin wax and that the content of paraffin wax in the composite is 65wt%.The maximum latent heat and its relevant melting point of composite are 95 J/g and 30℃,respectively.

  17. Toward High Performance Integrated Semiconductor Micro and Nano Lasers Enabled by Transparent Conducting Materials: from Thick Structure to Thin Film

    Science.gov (United States)

    Ou, Fang

    Integrated semiconductor lasers working at the wavelength around 1.3 microm and 1.55 microm are of great interest for the research of photonic integrated circuit (PIC) since they are the crucial components for optical communications and many other applications. To satisfy the requirement of the next generation optical communication and computing systems, integrated semiconductor lasers are expected to have high device performance like very low lasing threshold, high output powers, high speed and possibility of being integrated with electronics. This dissertation focuses on the design and realization of InP based high performance electrically pumped integrated semiconductor lasers. In the dissertation, we first design the tall structure based electrically pumped integrated micro-lasers. Those lasers are capable of giving >10 mW output power with a moderate low threshold current density (0.5--5 kA/cm 2). Besides, a new enhanced radiation loss based coupler design is demonstrated to realize single directional output for curvilinear cavities. Second, the thin film structure based integrated semiconductor laser designs are proposed. Both structures use the side conduction geometry to enable the electrical injection into the thin film laser cavity. The performance enhancement of the thin film structure based lasers is analyzed compared to the tall structure. Third, we investigate the TCO materials. CdO deposited by PLD and In 2O3 deposited by IAD are studied from aspects of their physical, optical and electrical properties. Those materials can give a wide range of tunability in their conductivity (1--5000 S/cm) and optical transparency (loss 200--5000 cm-1), which is of great interest in realizing novel nanophotonic devices. In addition, the electrical contact properties of those materials to InP are also studied. Experiment result shows that both CdO and In2O3 can achieve good ohmic contact to n-InP with contact resistance as low as 10-6O·cm 2. At last, we investigate

  18. Storage tank materials for biodiesel blends; the analysis of fuel property changes

    Directory of Open Access Journals (Sweden)

    Nurul Komariah Leily

    2017-01-01

    Full Text Available Fuel stability is one of major problem in biodiesel application. Some of the physical properties of biodiesel are commonly changed during storage. The change in physico-chemical properties is strongly correlated to the stability of the fuel. This study is objected to observe the potential materials for biodiesel storage. The test was conducted in three kinds of tank materials, such as glass, HDPE, and stainless steel. The fuel properties are monitored in 12 weeks, while the sample was analyzed every week. Biodiesel used is palm oil based. The storage tanks were placed in a confined indoor space with range of temperature 27–34 °C. The relative humidity and sunshine duration on the location was also evaluated. The observed properties of the fuel blends were density, viscosity and water content. During 12 weeks of storage, the average density of B20 was changed very slightly in all tanks, while the viscosity was tend to increase sharply, especially in polimerics tank. Water content of B20 was increased by the increase of storage time especially in HDPE tank. In short period of storage, the biodiesel blends is found more stable in glass tank due to its versatility to prohibit oxidation, degradation, and its chemical resistance.

  19. Integrated Data Collection Analysis (IDCA) Program - Mixing Procedures and Materials Compatibility

    Energy Technology Data Exchange (ETDEWEB)

    Olinger, Becky D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sandstrom, Mary M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Warner, Kirstin F. [Naval Surface Warfare Center (NSWC-IHD), Indian Head, MD (United States); Sorensen, Daniel N. [Naval Surface Warfare Center (NSWC-IHD), Indian Head, MD (United States); Remmers, Daniel L. [Naval Surface Warfare Center (NSWC-IHD), Indian Head, MD (United States); Moran, Jesse S. [Naval Surface Warfare Center (NSWC-IHD), Indian Head, MD (United States); Shelley, Timothy J. [Air Force Research Lab. (AFRL), Tyndall AFB, FL (United States); Whinnery, LeRoy L. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Hsu, Peter C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Whipple, Richard E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kashgarian, Michaele [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reynolds, John G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2011-01-14

    Three mixing procedures have been standardized for the IDCA proficiency test—solid-solid, solid-liquid, and liquid-liquid. Due to the variety of precursors used in formulating the materials for the test, these three mixing methods have been designed to address all combinations of materials. Hand mixing is recommended for quantities less than 10 grams and Jar Mill mixing is recommended for quantities over 10 grams. Consideration must also be given to the type of container used for the mixing due to the wide range of chemical reactivity of the precursors and mixtures. Eight web site sources from container and chemical manufacturers have been consulted. Compatible materials have been compiled as a resource for selecting containers made of materials stable to the mixtures. In addition, container materials used in practice by the participating laboratories are discussed. Consulting chemical compatibility tables is highly recommended for each operation by each individual engaged in testing the materials in this proficiency test.

  20. Formulation Changes Affect Material Properties and Cell Behavior in HA-Based Hydrogels

    Directory of Open Access Journals (Sweden)

    Thomas Lawyer

    2012-01-01

    Full Text Available To develop and optimize new scaffold materials for tissue engineering applications, it is important to understand how changes to the scaffold affect the cells that will interact with that scaffold. In this study, we used a hyaluronic acid- (HA- based hydrogel as a synthetic extracellular matrix, containing modified HA (CMHA-S, modified gelatin (Gtn-S, and a crosslinker (PEGda. By varying the concentrations of these components, we were able to change the gelation time, enzymatic degradation, and compressive modulus of the hydrogel. These changes also affected fibroblast spreading within the hydrogels and differentially affected the proliferation and metabolic activity of fibroblasts and mesenchymal stem cells (MSCs. In particular, PEGda concentration had the greatest influence on gelation time, compressive modulus, and cell spreading. MSCs appeared to require a longer period of adjustment to the new microenvironment of the hydrogels than fibroblasts. Fibroblasts were able to proliferate in all formulations over the course of two weeks, but MSCs did not. Metabolic activity changed for each cell type during the two weeks depending on the formulation. These results highlight the importance of determining the effect of matrix composition changes on a particular cell type of interest in order to optimize the formulation for a given application.

  1. Ternary mixture of fatty acids as phase change materials for thermal energy storage applications

    Directory of Open Access Journals (Sweden)

    Karunesh Kant

    2016-11-01

    Full Text Available The present study deals with the development of ternary mixtures of fatty acids for low temperature thermal energy storage applications. The commercial grade fatty acids such as Capric Acid (CA, Lauric Acid (LA, Palmitic Acid (PA and Stearic Acid (SA, have been used to prepare stable, solid–liquid phase change material (PCM for the same. In this regard, a series of ternary mixture i.e. CA–LA–SA (CLS and CA–PA–SA (CPS have been developed with different weight percentages. Thermal characteristics of these developed ternary mixture i.e. melting temperature and latent heat of fusion have been measured by using Differential Scanning Calorimeter (DSC technique. The synthesized materials are found to have melting temperature in the range of 14–21 °C (along with adequate amount of latent heat of fusion, which may be quite useful for several low temperature thermal energy storage applications.

  2. Ultrafast broadband tuning of resonant optical nanostructures using phase change materials

    CERN Document Server

    Rudé, Miquel; Cetin, Arif E; Miller, Timothy A; Carrilero, Albert; Wall, Simon; de Abajo, F Javier García; Altug, Hatice; Pruneri, Valerio

    2015-01-01

    The phenomenon of extraordinary optical transmission {EOT} through arrays of nanoholes patterned in a metallic film has emerged as a promising tool for a wide range of applications, including photovoltaics, nonlinear optics, and sensing. Designs and methods enabling the dynamic tuning of the optical resonances of these structures are essential to build efficient optical devices, including modulators, switches, filters, and biosensors. However, the efficient combination of EOT and dynamic tuning remains a challenge, mainly because of the lack of materials that can induce modulation over a broad spectral range at high speeds. Here, we demonstrate tuneable resonance wavelength shifts as large as 385 nm - an order of magnitude higher than previously reported - through the combination of phase change materials {PCMs}, which exhibit dramatic variations in optical properties upon transitions between amorphous and crystalline phases, with properly designed subwavelength nanohole metallic arrays. We further find throu...

  3. Design of a Protection Thermal Energy Storage Using Phase Change Material Coupled to a Solar Receiver

    Science.gov (United States)

    Verdier, D.; Falcoz, Q.; Ferrière, A.

    2014-12-01

    Thermal Energy Storage (TES) is the key for a stable electricity production in future Concentrated Solar Power (CSP) plants. This work presents a study on the thermal protection of the central receiver of CSP plant using a tower which is subject to considerable thermal stresses in case of cloudy events. The very high temperatures, 800 °C at design point, impose the use of special materials which are able to resist at high temperature and high mechanical constraints and high level of concentrated solar flux. In this paper we investigate a TES coupling a metallic matrix drilled with tubes of Phase Change Material (PCM) in order to store a large amount of thermal energy and release it in a short time. A numerical model is developed to optimize the arrangement of tubes into the TES. Then a methodology is given, based from the need in terms of thermal capacity, in order to help the choice of the geometry.

  4. High Temperature Phase Change Materials for Thermal Energy Storage Applications: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, J.; Glatzmaier, G. C.; Starace, A.; Turchi, C.; Ortega, J.

    2011-08-01

    To store thermal energy, sensible and latent heat storage materials are widely used. Latent heat thermal energy storage (TES) systems using phase change materials (PCM) are useful because of their ability to charge and discharge a large amount of heat from a small mass at constant temperature during a phase transformation. Molten salt PCM candidates for cascaded PCMs were evaluated for the temperatures near 320 degrees C, 350 degrees C, and 380 degrees C. These temperatures were selected to fill the 300 degrees C to 400 degrees C operating range typical for parabolic trough systems, that is, as one might employ in three-PCM cascaded thermal storage. Based on the results, the best candidate for temperatures near 320 degrees C was the molten salt KNO3-4.5wt%KCl. For the 350 degrees C and 380 degrees C temperatures, the evaluated molten salts are not good candidates because of the corrosiveness and the high vapor pressure of the chlorides.

  5. Artisticc: An Art and Science Integration Project to Enquire into Community Level Adaptation to Climate Change

    Science.gov (United States)

    Vanderlinden, J. P.; Baztan, J.

    2014-12-01

    The prupose of this paper is to present the "Adaptation Research a Transdisciplinary community and policy centered appoach" (ARTisticc) project. ARTisticc's goal is to apply innovative standardized transdisciplinary art and science integrative approaches to foster robust, socially, culturally and scientifically, community centred adaptation to climate change. The approach used in the project is based on the strong understanding that adaptation is: (a) still "a concept of uncertain form"; (b) a concept dealing with uncertainty; (c) a concept that calls for an analysis that goes beyond the traditional disciplinary organization of science, and; (d) an unconventional process in the realm of science and policy integration. The project is centered on case studies in France, Greenland, Russia, India, Canada, Alaska, and Senegal. In every site we jointly develop artwork while we analyzing how natural science, essentially geosciences can be used in order to better adapt in the future, how society adapt to current changes and how memories of past adaptations frames current and future processes. Artforms are mobilized in order to share scientific results with local communities and policy makers, this in a way that respects cultural specificities while empowering stakeholders, ARTISTICC translates these "real life experiments" into stories and artwork that are meaningful to those affected by climate change. The scientific results and the culturally mediated productions will thereafter be used in order to co-construct, with NGOs and policy makers, policy briefs, i.e. robust and scientifically legitimate policy recommendations regarding coastal adaptation. This co-construction process will be in itself analysed with the goal of increasing arts and science's performative functions in the universe of evidence-based policy making. The project involves scientists from natural sciences, the social sciences and the humanities, as well as artitis from the performing arts (playwriters

  6. Integrating research tools to support the management of social-ecological systems under climate change

    Directory of Open Access Journals (Sweden)

    Brian W. Miller

    2014-09-01

    Full Text Available Developing resource management strategies in the face of climate change is complicated by the considerable uncertainty associated with projections of climate and its impacts and by the complex interactions between social and ecological variables. The broad, interconnected nature of this challenge has resulted in calls for analytical frameworks that integrate research tools and can support natural resource management decision making in the face of uncertainty and complex interactions. We respond to this call by first reviewing three methods that have proven useful for climate change research, but whose application and development have been largely isolated: species distribution modeling, scenario planning, and simulation modeling. Species distribution models provide data-driven estimates of the future distributions of species of interest, but they face several limitations and their output alone is not sufficient to guide complex decisions for how best to manage resources given social and economic considerations along with dynamic and uncertain future conditions. Researchers and managers are increasingly exploring potential futures of social-ecological systems through scenario planning, but this process often lacks quantitative response modeling and validation procedures. Simulation models are well placed to provide added rigor to scenario planning because of their ability to reproduce complex system dynamics, but the scenarios and management options explored in simulations are often not developed by stakeholders, and there is not a clear consensus on how to include climate model outputs. We see these strengths and weaknesses as complementarities and offer an analytical framework for integrating these three tools. We then describe the ways in which this framework can help shift climate change research from useful to usable.

  7. Integration of study material in the problem-based learning method

    Directory of Open Access Journals (Sweden)

    S. Becker

    2003-05-01

    Full Text Available Throughout the world educators are starting to realise that integrated curricula reflect the “real world”. Students learn how to integrate theory appropriately with practice and it stimulates higher order thinking skills. Problem-based learning (PBL was used as a learning strategy in an integrated undergraduate programme. A quantatative non-experimental design, a survey, was used to determine how problem-based learning influences integration of learning by the students. Using a purposive sampling method all the first-year nursing students (43 at the University of the Free State participating in the programme were included in the study. Data was collected by means of a student perception questionnaire (SPQ.

  8. Phase Change Materials (PCM) fabricated in vertical structures for reconfigurable and tunable circuits

    Science.gov (United States)

    Barajas, Eduardo; Coutu, Ronald A.

    2014-03-01

    Germanium Telluride (GeTe) can be described as a non-volatile (latching state) phase change material (PCM) in memory applications. GeTe also exhibits a volatile (reversible state) region when heated and cooled between 100-180 °C. At temperatures higher than 185 °C the material crystallizes and "latches" until a temperature near to its melting point (725 °C) is reached and cooled rapidly (quenching). Germanium Antimony Telluride (GeSbTe) or also known as GST has similar characteristics as GeTe. GST also exhibits a volatile (reversible state) region when heated and cooled between 100-150 °C. GST crystallizes at 155 °C and its melting point is 600 °C. This paper demonstrates the feasibility of fabricating radio frequency (RF) devices of phase change materials (PCM) and it also presents a comparison between amorphous and crystalline PCMs in the RF spectrum. Previous work focuses on exploiting GeTe and GST as nonvolatile materials in memory applications, and also on characterizing them for their electrical and mechanical properties. The approach here focuses on fabricating RF devices and analyzing their responses. A simulation with resistor-capacitor (RC) and resistor-inductor (RL) circuits is presented to represent the response of the RF devices under testing. The fabrication process includes two-layer and four-layer devices on the Si wafer. PCMs are sputtered and the test pads are deposited using electron beam evaporation. Results show that these RF devices alone can serve as a low pass filter with a cutoff frequency of 10 MHz.

  9. Integrating Bill of Materials Data Into the Armys Enterprise Resource Planning Systems

    Science.gov (United States)

    2016-05-17

    Integration with SAP [Systems, Applications, and Products ] ERP, Simha R. Magal and Jeffrey B. Word describe service - oriented architecture (SOA) as a...required to build a product . In integrated ERP envi- ronments, such as the Logistics Mod- ernization Program, Global Combat Support System–Army (GCSS...enterprise-level BOM data, these organizations are AESIP and the Logistics Product Data Store (LPDS). Fielded in July 2015, GCSS–Army release 14.2

  10. Effect of expanded graphite on the phase change materials of high density polyethylene/wax blends

    Energy Technology Data Exchange (ETDEWEB)

    AlMaadeed, M.A., E-mail: m.alali@qu.edu.qa [Center for Advanced Materials, Qatar University, 2713 Doha (Qatar); Labidi, Sami [Center for Advanced Materials, Qatar University, 2713 Doha (Qatar); Krupa, Igor [QAPCO Polymer Chair, Center for Advanced Materials, Qatar University, P.O. Box 2713, Doha (Qatar); Karkri, Mustapha [Université Paris-Est CERTES, 61 avenue du Général de Gaulle, 94010 Créteil (France)

    2015-01-20

    Highlights: • Expanded graphite (EG) and low melting point (42.3 °C) wax were added to HDPE to form phase change material. • EG was well dispersed in the composites and did not affect the melting or crystallization of the HDPE matrix. • EG increased the thermal stability of the composites by reducing chain mobility and inhibiting degradation. • The addition of a relatively small quantity of EG enhances the heat conduction in the composite. • HDPE/40% RT42 that contained up to 15% EG demonstrated excellent mechanical and thermal properties and can be used as PCM. - Abstract: Phase change materials fabricated from high density polyethylene (HDPE) blended with 40 or 50 wt% commercial wax (melting point of 43.08 °C) and up to 15 wt% expanded graphite (EG) were studied. Techniques including scanning electron microscope (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and an experimental device to measure diffusivity and conductivity (DICO) were used to determine the microstructural, mechanical and thermal properties of the composites. The composites possessed good mechanical properties. Additionally, no leaching was observed during material processing or characterization. Although the Young’s modulus increased with the addition of EG, no significant changes in tensile strength were detected. The maximum Young’s modulus achieved was 650 MPa for the HDPE/40% wax composite with 15 wt% EG. The EG was well dispersed within the composites and did not affect the melting or crystallization of the HDPE matrix. The incorporation of EG increased the thermal stability of the composites by reducing chain mobility and inhibiting degradation. The intensification of thermal conductivity occurred with increasing fractions of EG, which was attributed to the high thermal conductivity of graphite. The maximum quantity of heat stored by latent heat was found for the HDPE/40% wax composite with EG. The addition of a relatively small quantity

  11. Nature of defects and gap states in GeTe model phase change materials

    Science.gov (United States)

    Huang, B.; Robertson, J.

    2012-03-01

    The electrical storage mechanism in GeSbTe phase change materials is discussed in terms of their gap states using GeTe as a model system. The lowest energy defect in crystalline rhombohedral GeTe phase is the Ge vacancy, because it reconstructs along the resonant bonding directions. The lowest energy in amorphous GeTe is the divalent Te atom, which creates overlapping band-tail states that pin Fermi level EF near midgap. In contrast, the lowest cost defect in disordered phase in GeSbTe superlattices is the Te interstitial whose negative correlation energy pins EF near midgap.

  12. Micromechanical modelling of the elastoplastic behaviour of metallic material under strain-path changes

    Science.gov (United States)

    Fajoui, Jamal; Gloaguen, David; Courant, Bruno; Guillén, Ronald

    2009-07-01

    A two-level homogenization approach is applied for the micromechanical modelling of the elastoplastic material behaviour during various strain-path changes. A mechanical description of the grain is developed through a micro-meso transition based on a modified elastoplastic self-consistent approach which takes into account the dislocation evolution. Next, a meso-macro transition using a self-consistent model is used to deduce the macroscopic behaviour of the polycrystal. A correct agreement is observed between the simulations and the experimental results at the mesoscopic and macroscopic levels.

  13. Analysis of Phase Change Material in Glazing Systems in Future Zero-Energy-Buildings

    DEFF Research Database (Denmark)

    Winther, Frederik Vildbrad; Heiselberg, Per; Jensen, Rasmus Lund

    2016-01-01

    the thermal storage capacity of the glazed facade by using phase change material (PCM), in the glazing cavity, reduces the cooling demand. When wanting to use this technology under colder weather conditions, the pane can potentially reduce the heat loss of the pane thereby minimizing energy demand for heating.......When designing glazed constructions, this often results in thermally light constructions, with a low time constant. In order for these buildings to improve the redistribution of loads between night and day, solutions such as active slabs and exposed concrete cores are often used. However...

  14. Numerical computation of solar heat storage in phase change material/concrete wall

    Directory of Open Access Journals (Sweden)

    Mustapha Faraji

    2014-01-01

    Full Text Available A one-dimensional mathematical model was developed in order to analyze and optimize the latent heat storage wall. Two layers of phase change material (PCM are sandwiched within a concrete wall. The governing equations for energy transport were developed by using the enthalpy method and discretized with volume control scheme. A series of numerical investigations were conducted. The effect of the melting temperature on the possibility of increasing the energy performance of the proposed heating system was analyzed. Results are obtained for thermal gain and temperature fluctuation. The charging/discharging process was also presented and analyzed.

  15. Low-power switching of phase-change materials with carbon nanotube electrodes.

    Science.gov (United States)

    Xiong, Feng; Liao, Albert D; Estrada, David; Pop, Eric

    2011-04-29

    Phase-change materials (PCMs) are promising candidates for nonvolatile data storage and reconfigurable electronics, but high programming currents have presented a challenge to realize low-power operation. We controlled PCM bits with single-wall and small-diameter multi-wall carbon nanotubes. This configuration achieves programming currents of 0.5 microampere (set) and 5 microamperes (reset), two orders of magnitude lower than present state-of-the-art devices. Pulsed measurements enable memory switching with very low energy consumption. Analysis of over 100 devices finds that the programming voltage and energy are highly scalable and could be below 1 volt and single femtojoules per bit, respectively.

  16. Simultaneous microscopic measurements of thermal and spectroscopic fields of a phase change material

    Science.gov (United States)

    Romano, M.; Ryu, M.; Morikawa, J.; Batsale, J. C.; Pradere, C.

    2016-05-01

    In this paper, simultaneous microscopic measurements of thermal and spectroscopic fields of a paraffin wax n-alkane phase change material are reported. Measurements collected using an original set-up are presented and discussed with emphasis on the ability to perform simultaneous characterization of the system when the proposed imaging process is used. Finally, this work reveals that the infrared wavelength contains two sets of important information. Furthermore, this versatile and flexible technique is well adapted to characterize many systems in which the mass and heat transfers effects are coupled.

  17. Melting of nanoparticles-enhanced phase change material (NEPCM) in vertical semicircle enclosure: numerical study

    Energy Technology Data Exchange (ETDEWEB)

    Jourabian, Mahmoud [University of Trieste, Piazzale (Italy); Farhadi, Mousa [Babol Noshirvani University of Technology, Shariati Avenue (Iran, Islamic Republic of)

    2015-09-15

    Convection melting of ice as a Phase change material (PCM) dispersed with Cu nanoparticles, which is encapsulated in a semicircle enclosure is studied numerically. The enthalpy-based Lattice Boltzmann method (LBM) combined with a Double distribution function (DDF) model is used to solve the convection-diffusion equation. The increase in solid concentration of nanoparticles results in the enhancement of thermal conductivity of PCM and the decrease in the latent heat of fusion. By enhancing solid concentration of nanoparticles, the viscosity of nanofluid increases and convective heat transfer dwindles. For all Rayleigh numbers investigated in this study, the insertion of nanoparticles in PCM has no effect on the average Nusselt number.

  18. Integration of phase change materials in compressed hydrogen gas systems: Modelling and parametric analysis

    DEFF Research Database (Denmark)

    Mazzucco, Andrea; Rothuizen, Erasmus; Jørgensen, Jens-Erik;

    2016-01-01

    temperature. Results show that a 10-mm-thick layer of paraffin wax can absorb enough heat to reduce the adiabatic temperature by 20 K when compared to a standard Type IV tank, but its influence on the hydrogen peak temperature that occurs at the end of refueling is modest. The heat transfer from the gas...

  19. A compressed hydrogen gas storage system with an integrated phase change material

    DEFF Research Database (Denmark)

    Mazzucco, Andrea; Rothuizen, Erasmus Damgaard; Jørgensen, Jens Erik;

    2015-01-01

    below the critical temperature of 85 °C, while filling the hydrogen at ambient temperature. Results show that a 10-mm-thick layer of paraffin wax can absorb enough heat to reduce the adiabatic temperature by 20 K when compared to a standard Type IV tank. The heat transfer from the gas to the phase...

  20. Integration of Phase Change Material in Furniture for Improvement of Building Energy Flexibility

    DEFF Research Database (Denmark)

    Johra, Hicham; Heiselberg, Per

    This report aims to review the different scientific publications and technical documentations which investigated the influence of furniture parts on indoor environment and the use of PCM for building energy applications.......This report aims to review the different scientific publications and technical documentations which investigated the influence of furniture parts on indoor environment and the use of PCM for building energy applications....