WorldWideScience

Sample records for evacuated aerogel glazings

  1. Evacuated aerogel glazings

    DEFF Research Database (Denmark)

    Schultz, Jørgen Munthe; Jensen, Karsten Ingerslev

    2008-01-01

    This paper describes the main characteristics of monolithic silica aerogel and its application in evacuated superinsulating aerogel glazing including the evacuation and assembling process. Furthermore, the energetic benefit of aerogel glazing is quantified. In evacuated aerogel glazing the space ......) combined with a solar energy transmittance above 0.75.......This paper describes the main characteristics of monolithic silica aerogel and its application in evacuated superinsulating aerogel glazing including the evacuation and assembling process. Furthermore, the energetic benefit of aerogel glazing is quantified. In evacuated aerogel glazing the space...... between the glass panes is filled with monolithic silica aerogel evacuated to a rough vacuum of approximately 1-10 hPa. The aerogel glazing does not depend on use of low emissive coatings that have the drawback of absorbing a relatively large part of the solar radiation that otherwise could reduce...

  2. Evacuation and assembly of aerogel glazings

    DEFF Research Database (Denmark)

    Jensen, Karsten Ingerslev

    1999-01-01

    The application of monolithic silica aerogel as transparent insulation material for windows has been investigated for some years. It has been realised that a major problem of an industrial production of aerogel glazings will be the time for evacuation of the aerogel material. However, in a previous...... process, it can be considered as semi-online, and especially the capital cost is significantly lower for this method in comparison with a true online process. So hereby, a major obstacle is overcome with respect to a first industrial production of aerogel glazings.The apparatus has been constructed...

  3. Monolithic Silica aerogel in superinsulating glazings

    DEFF Research Database (Denmark)

    Duer, Karsten; Svendsen, Sv Aa Højgaard

    1988-01-01

    . This phenomenon is considered being the main obstacle to incorporate the material in clear glazings but a significant improvement of the optical quality of aerogel has been observed during the last five years. A number of prototypical evacuated 500x500x28 mm aerogel double glazed units employing a new edge seal...... competetion in heating dominated climates....

  4. Super insulating aerogel glazing

    DEFF Research Database (Denmark)

    Schultz, Jørgen Munthe; Jensen, Karsten Ingerslev; Kristiansen, Finn Harken

    2004-01-01

    form the weakest part of the thermal envelope with respect to heat loss coefficient, but on the other hand also play an important role for passive solar energy utilisation. For window orientations other than south, the net energy balance will be close to or below zero. However, the properties......Monolithic silica aerogel offers the possibility of combining super insulation and high solar energy transmittance, which has been the background for a previous and a current EU project on research and development of monolithic silica aerogel as transparent insulation in windows. Generally, windows...... of aerogel glazing will allow for a positive net energy gain even for north facing vertical windows in a Danish climate during the heating season. This means that high quality daylight can be obtained even with additional energy gain. On behalf of the partners of the two EU projects, results related...

  5. Super insulating aerogel glazing

    DEFF Research Database (Denmark)

    Schultz, Jørgen Munthe; Jensen, Karsten Ingerslev; Kristiansen, Finn Harken

    2005-01-01

    of the glass and a heat-treatment of the aerogel increases the visible quality and the solar energy transmittance. A low-conductive rim seal solution with the required vacuum barrier properties has been developed along with a reliable assembly and evacuation process. The prototypes have a centre heat loss...

  6. Development of windows based on highly insulating aerogel glazings

    DEFF Research Database (Denmark)

    Jensen, Karsten Ingerslev; Schultz, Jørgen Munthe; Kristiansen, Finn Harken

    2004-01-01

    of buildings, the window area is the weakest part with respect to the heat loss, but at the same time, it also provides e.g. solar energy gain. Glazing prototypes have been made of aerogel tiles of about 55 cm sq. (elaborated within the projects). Those tiles are quickly evacuated and easily sealed between two...... glass panes and a specific rim seal. A heat treatment phase (after the supercritical CO2 drying) of the aerogel is currently being developed in order to improve its optical quality. This step increases the solar transmittance about 6 percent points. For glazing prototypes with an aerogel thickness...... of approx. 15 mm, a centre heat loss coefficient of below 0.7 W/m² K and a solar transmittance of 76% have been obtained. The research is funded in part by the European Commission within the frameworks of the Non-Nuclear Energy Programme – JOULE III and the Energy, Environment and Sustainable Development...

  7. Properties of aerogels in glazings

    DEFF Research Database (Denmark)

    Schultz, Jørgen Munthe

    1998-01-01

    This report describes the final tests carried out on an advanced apparatus for measurement of thermal conductivity of materials at atmospheric pressure and different levels of evacuation. The apparatus was designed and constructed in the phase 1 of the project. Difficulties with the control system...... have been solved and measurements have been carried out on common polystyrene foam insulation at atmospheric pressure. The measurements have been compared with results from reference measurements and a difference of only 0.3% was found in measured thermal conductivity. Measurements on monolithic silica...... aerogel were performed at 5 different pressure levels in the range 0.2 - 1000 hPa. The measured equivalent thermal conductivity is in the range 8.9 - 16.4 mW/(m K) which corresponds very well with results obtained by institutes in Germany and France....

  8. Complex multimaterial insulating frames for windows with evacuated glazing

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Yueping; Eames, Philip C.; Hyde, Trevor J. [Centre for Sustainable Technologies, School of the Built Environment, University of Ulster, Newtownabbey, N. Ireland BT37 0QB (United Kingdom); Norton, Brian [Dublin Institute of Technology, Aungier Street, Dublin 2 (Ireland)

    2005-09-01

    The thermal performance of a complex multimaterial frame consisting of an exoskeleton framework and cavities filled with insulant materials enclosing an evacuated glazing was simulated using a two-dimensional finite element model and the results were validated experimentally using a guarded hot box calorimeter. The analysed 0.5m by 0.5m evacuated glazing consisted of two low-emittance film coated glass panes supported by an array of 0.32mm diameter pillars spaced 25mm apart, contiguously sealed by a 10mm wide metal edge seal. Thermal performance of windows employing evacuated glazing set in various complex multimaterial frames were analysed in detail. Very good agreement was found between simulations and experimental measurements of surface temperatures of the evacuated glazing window system. The heat loss from a window with an evacuated glazing and a complex multimaterial frame is about 80% of that for a window comprised of an evacuated glazing set in a single material solid frame. (author)

  9. Complex multimaterial insulating frames for windows with evacuated glazing

    Energy Technology Data Exchange (ETDEWEB)

    Yueping Fang; Eames, P.C.; Hyde, T.J. [University of Ulster, Newtonabbey (United Kingdom). Centre for Sustainable Technologies; Norton, B. [Dublin Institute of Technology, Dublin (Ireland)

    2005-09-01

    The thermal performance of a complex multimaterial frame consisting of an exoskeleton framework and cavities filled with insulant materials enclosing an evacuated glazing was simulated using a two-dimensional finite element model and the results were validated experimentally using a guarded hot box calorimeter. The analysed 0.5 m by 0.5 m evacuated glazing consisted of two low-emittance film coated glass panes supported by an array of 0.32 mm diameter pillars spaced 25 mm apart, contiguously sealed by a 10 mm wide metal edge seal. Thermal performance of windows employing evacuated glazing set in various complex multimaterial frames were analysed in detail. Very good agreement was found between simulations and experimental measurements of surface temperatures of the evacuated glazing window system. The heat loss from a window with an evacuated glazing and a complex multimaterial frame is about 80% of that for a window comprised of an evacuated glazing set in a single material solid frame. (author)

  10. Highly Insulating and Light Transmitting Aerogel Glazing for Super Insulating Windows (HILIT+)

    DEFF Research Database (Denmark)

    Jensen, Karsten Ingerslev; Kristiansen, Finn Harken; Schultz, Jørgen Munthe

    2005-01-01

    to 1000 m²/g), the material is proposed to serve as substrate for catalytic materials. • The special pore structure of aerogel could be used for gas filters in the 20 to 100 nm region. • The sound velocity within aerogel is in the range of 100 to 300 m/s, which should be one of the lowest for an inorganic......-free nano-structured aerogel materials through a reasonably fast and reproducible process. The applicative part of this project aimed at elaborating, studying and optimising “state-of-the-art” (0.5 W/m2 K) aerogel glazings for windows. An important issue was the risk of outside condensation and rime and its....... No other known glazing exhibits such an excellent combination of solar transmittance and heat loss coefficient. The annual energy savings compared to triple low energy glazing is in the range of 10 – 20% depending on type of building. Beside the application in glazing production the HILIT+ aerogel material...

  11. Highly Insulating and Light Transmitting Aerogel Glazing for Super Insulating Windows (HILIT+)

    DEFF Research Database (Denmark)

    Jensen, Karsten Ingerslev

    2005-01-01

    batch. Furthermore the production time has been reduced to 1/3 of the initial production time through detailed theoretical and experimental analyses of especially the supercritical washing step included in the drying phase. At the same time the production plant have been modified to recycle most...... insulation purposes. The edge seal solution shows only a very limited thermal bridge effect. The final glazing has a total solar energy transmittance above 85% and a U-value of 0.7 W/m2 K for about 14 mm aerogel thickness, which for a 20 mm thickness corresponds to a U-value of approximately 0.5 W/m2K...

  12. Transparent aerogel Windows

    DEFF Research Database (Denmark)

    Jensen, Karsten Ingerslev; Schultz, Jørgen Munthe

    the supercritical washing step included in the drying phase. At the same time the production plant have been modified to recycle most of the chemicals involved in the production process. A large number of aerogel glazing prototypes have been made with partly evacuated aerogel in between two layers of low iron...... and anti reflection treated glass panes with an airtight edge seal solution based on multi-layered plastic foil developed for vacuum insulation purposes. The edge seal solution shows only a very limited thermal bridge effect. The final glazing has a total solar energy transmittance about 87% and a U...

  13. Aerogel

    Indian Academy of Sciences (India)

    Aerogel, a material not much denser than air on a foggy morning ... between a liquid and a gas, leading to minimum effect on surface ... approached by the French Government to design a method to ... catalysts. • Aerogel dust in grain and seed stocks was found to kill insects by mere ... radiation detectors in nuclear reactors.

  14. Full scale investigation on aerogel windows exposed to real climatic conditions

    DEFF Research Database (Denmark)

    Schultz, Jørgen Munthe; Nielsen, Lars Thomsen

    -filling and hard low-emissivity coatings. The energy saving is reached without significant change in the indoor thermal comfort level.Highly insulating glazing types as aerogel glazings and triple-layered low-energy glazings lead to outside surface temperatures on the glazing that often are below the dew point...

  15. Glazed Concrete

    DEFF Research Database (Denmark)

    Bache, Anja Margrethe

    2010-01-01

    Why glazed concrete? Concrete hardens and finds its strength at room temperature whereas clay products must first be fired before they achieve this strength. They are stronger and three times as durable as clay products, which is a weighty reason for choosing concrete.5 Another reason, which....... If this succeeds, it will be possible to manufacture thin, large-scale glazed concrete panels comparable in size to concrete sandwich construction and larger which, with or without back-casting, can work as load-bearing construction elements....

  16. B1 Aerogels

    DEFF Research Database (Denmark)

    Duer, Karsten; Svendsen, Sv Aa Højgaard

    1996-01-01

    , engineering and architectural basis which will support the appropriate use of aerogels in windows, solar collectors and passive solar applications, with the aim of saving or producing thermal energy for use in buildings".This objective is in very good agreement with the general scope of task 18 but where Task...... of aerogel as a material for window applications3. Construction of an aerogel DGU and measurement of key performance parameters. The goal for the aerogel DGU was to reach a Total Solar Energy Transmittance above 0.75 and a U-value below 0.5 W/m²K. These are values that can not be simultaneously reached......The report summarizes the work that has been carried out within the project "B1 AEROGELS" as a part of the IEA SH&CP Task 18 "Advanced Glazing and Associated Materials For Solar And Building Applications".By providing at the same time thermal insulation and transparency the silica aerogel is a very...

  17. Aerogels: transparent and super-insulating materials; Les aerogels: isolants transparent-super isolants

    Energy Technology Data Exchange (ETDEWEB)

    Melka, S.; Rigacci, A.; Achard, P.; Bezian, J.J. [Ecole des Mines de Paris, 06 - Sophia-Antipolis (France); Sallee, H.; Chevalier, B. [Centre des Sciences et Techniques du Batiment, 38 - Saint-Martin-d`Heres (France)

    1996-12-31

    Recent studies have demonstrated the super-insulating properties of silica aerogel in its monolithic or finely divided state. In its monolithic state, this material conciliates excellent thermal insulation performances, a good transmission of visible light and interesting acoustic properties. Also its amazing structural characteristics (lightness, high global porosity, small diameter of pores) are particularly interesting for its use in double glazing windows as transparent insulating spacer. The aim of the work carried out by the Energetic Centre of the Ecole des Mines of Paris is to understand the thermal transfer phenomena in all forms of silica aerogel. In this paper, the main steps of the synthesis process of monolithic silica aerogel is presented with the thermal conductivities obtained. Then, a model is built to describe the thermal transfer mechanisms in finely divided aerogel beds. Finally, the hot wire thermal characterization method is presented and the results obtained on silica aerogels are discussed. (J.S.) 16 refs.

  18. Fabricate-On-Demand Vacuum Insulating Glazings

    Energy Technology Data Exchange (ETDEWEB)

    McCamy, James W. [PPG Industries, Inc., Pittsburgh, PA (United States)

    2017-09-19

    PPG proposed to design a fabricate-on-demand manufacturing process to overcome the cost and supply chain issues preventing widespread adoption of vacuum insulated glazing (VIG) units. To do so, we focused on improving three areas of VIG manufacturing that drive high costs and limit the ability for smaller manufacturers to enter the market: edge sealing, pillar design/placement, and evacuating the VIG.

  19. Graphene aerogels

    Science.gov (United States)

    Pauzauskie, Peter J; Worsley, Marcus A; Baumann, Theodore F; Satcher, Jr., Joe H; Biener, Juergen

    2015-03-31

    Graphene aerogels with high conductivity and surface areas including a method for making a graphene aerogel, including the following steps: (1) preparing a reaction mixture comprising a graphene oxide suspension and at least one catalyst; (2) curing the reaction mixture to produce a wet gel; (3) drying the wet gel to produce a dry gel; and (4) pyrolyzing the dry gel to produce a graphene aerogel. Applications include electrical energy storage including batteries and supercapacitors.

  20. Carbon aerogels

    International Nuclear Information System (INIS)

    Berthon-Fabry, S.; Achard, P.

    2003-06-01

    The carbon aerogel is a nano-porous material at open porosity, electrical conductor. The aerogels morphology is variable in function of the different synthesis parameters. This characteristic offers to the aerogels a better adaptability to many applications: electrodes (super condensers, fuel cells). The author presents the materials elaboration and their applications. It provides also the research programs: fundamental research, realization of super-condenser electrodes, fuel cells electrodes, gas storage materials and opaque materials for thermal insulation. (A.L.B.)

  1. Measurements of scattering, transmittance/reflectance, IR-transmittance and thermal conductivity of small aerogel samples

    DEFF Research Database (Denmark)

    Duer, Karsten; Svendsen, Sv Aa Højgaard

    1997-01-01

    By providing at the same time thermal insulation and transparency the silica aerogel is a very attractive material for the purpose of improving the thermal performance of windows. Nevertheless a lot of problems have to be solved on the way from concept to the developed product. The B1 Aerogels...... project deals with some of these problems.This report summarizes the work that has been carried out on the subject of characterizing the optical and thermal performance of different types of aerogels and aerogel-like materials for the purpose of using aerogel in clear glazings.All measurements presented...

  2. LARGE SCALE GLAZED

    DEFF Research Database (Denmark)

    Bache, Anja Margrethe

    2010-01-01

    OF SELECTED EXISTING BUILDINGS IN AND AROUND COPENHAGEN COVERED WITH MOSAIC TILES, UNGLAZED OR GLAZED CLAY TILES. ITS BUILDINGS WHICH HAVE QUALITIES THAT I WOULD LIKE APPLIED, PERHAPS TRANSFORMED OR MOST PREFERABLY, INTERPRETED ANEW, FOR THE LARGE GLAZED CONCRETE PANELS I AM DEVELOPING. KEYWORDS: COLOR, LIGHT...

  3. Spectrally selective glazings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-08-01

    Spectrally selective glazing is window glass that permits some portions of the solar spectrum to enter a building while blocking others. This high-performance glazing admits as much daylight as possible while preventing transmission of as much solar heat as possible. By controlling solar heat gains in summer, preventing loss of interior heat in winter, and allowing occupants to reduce electric lighting use by making maximum use of daylight, spectrally selective glazing significantly reduces building energy consumption and peak demand. Because new spectrally selective glazings can have a virtually clear appearance, they admit more daylight and permit much brighter, more open views to the outside while still providing the solar control of the dark, reflective energy-efficient glass of the past. This Federal Technology Alert provides detailed information and procedures for Federal energy managers to consider spectrally selective glazings. The principle of spectrally selective glazings is explained. Benefits related to energy efficiency and other architectural criteria are delineated. Guidelines are provided for appropriate application of spectrally selective glazing, and step-by-step instructions are given for estimating energy savings. Case studies are also presented to illustrate actual costs and energy savings. Current manufacturers, technology users, and references for further reading are included for users who have questions not fully addressed here.

  4. Triple vacuum glazing: Heat transfer and basic mechanical design constraints

    Energy Technology Data Exchange (ETDEWEB)

    Manz, H.; Brunner, S.; Wullschleger, L. [Swiss Federal Laboratories for Materials Testing and Research (EMPA), Laboratory for Applied Physics in Building, Ueberlandstrasse 129, CH-8600 Duebendorf (Switzerland)

    2006-12-15

    Given the major role played by windows with regard to energy losses from buildings in cold climates, low thermal transmittance is an indispensable property of glazing in low-energy buildings. Evacuation offers the only means of achieving negligible gaseous conduction in glazing cavities. Application of low-emittance coatings to glass sheet surfaces inside the cavity reduces the radiative heat transfer. The feasibility of double vacuum glazing using arrays of support pillars between the glass sheets has been shown by other authors. This type of glazing is commercially manufactured today. Based on these achievements, our study set out to investigate heat transfer in triple vacuum glazing by means of (i) an analytical thermal network model and (ii) a numerical finite difference model. The study focused on the impact of the following parameters on thermal transmittance: emittances of glass sheet surfaces inside the cavity, support pillar radius, support pillar separation and thermal conductivity of support pillar material. The design procedure for triple vacuum glazing taking into account not only thermal but also mechanical stresses due to atmospheric pressure, i.e., to enable identification of favourable parameter sets, is presented. Our findings suggest that use of the triple vacuum glazing concept can significantly reduce the thermal transmittances achieved by the best insulation glazing units currently on the market. E.g., a centre-of-glazing thermal transmittance of less than 0.2Wm{sup -2}K{sup -1} is achievable using stainless steel support pillars, 6mm/4mm/6mm sheets of untempered soda-lime glass and four low-emittance coatings ({epsilon}=0.03). (author)

  5. Aerogels Handbook

    CERN Document Server

    Aegerter, Michel A; Koebel, Matthias M

    2011-01-01

    Aerogels are the lightest solids known. Up to 1000 times lighter than glass and with a density as low as only four times that of air, they show very high thermal, electrical and acoustic insulation values and hold many entries in Guinness World Records. Originally based on silica, R&D efforts have extended this class of materials to non-silicate inorganic oxides, natural and synthetic organic polymers, carbon, metal and ceramic materials, etc. Composite systems involving polymer-crosslinked aerogels and interpenetrating hybrid networks have been developed and exhibit remarkable mechanical strength and flexibility. Even more exotic aerogels based on clays, chalcogenides, phosphides, quantum dots, and biopolymers such as chitosan are opening new applications for the construction, transportation, energy, defense and healthcare industries. Applications in electronics, chemistry, mechanics, engineering, energy production and storage, sensors, medicine, nanotechnology, military and aerospace, oil and gas recove...

  6. Development of vacuum glazing with advanced thermal properties - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Koebel, M.; Manz, H.

    2009-03-15

    Windows constitute a weak link in the building envelope and hence contribute significantly to the total heating energy demand in buildings. By evacuating the glazing cavity a vacuum glazing is created and heat transfer can be significantly reduced. This project was designed to build knowledge and technology necessary to fabricate vacuum glazing with advanced thermal properties. More specifically, various strategies for improvement of conventional technology were investigated. Of central importance was the development of a novel edge sealing approach which can in theory circumvent the main limitation of conventional glass soldering technology. This approach which is rapid, low temperature, low cost and completely vacuum compatible was filed for patenting in 2008. With regards to thermal insulation performance and glazing deflection, numerical studies were performed demonstrating the importance of nonlinear behavior with glazing size and the results published. A detailed service life prediction model was elaborated which defines a set of parameters necessary to keep the expected pressure increase below a threshold value of 0.1 Pa after 30 years. The model takes into account four possible sources of pressure increase and a getter material which acts as a sink. For the production of 0.5 m by 0.5 m glazing assembly prototypes, a high vacuum chamber was constructed and a first sealing prototype realized therein. The manufacture of improved prototypes and optimization of the anodic bonding edge sealing technology with emphasis on process relevant aspects is the goal of a follow-up project. (authors)

  7. Aerogel sorbents

    Energy Technology Data Exchange (ETDEWEB)

    Begag, Redouane; Rhine, Wendell E.; Dong, Wenting

    2018-04-03

    The current invention describes methods and compositions of various sorbents based on aerogels of various silanes and their use as sorbent for carbon dioxide. Methods further provide for optimizing the compositions to increase the stability of the sorbents for prolonged use as carbon dioxide capture matrices.

  8. Evacuation exercise

    CERN Multimedia

    AUTHOR|(CDS)2094367

    2017-01-01

    In the event of an emergency, it is important that staff and visitors are evacuated safely and efficiently. Hence CERN organises regularly emergency response and evacuation exercise (also known as an ‘evacuation drill’) in different buildings across the sites.

  9. Carbon aerogels; Les aerogels de carbone

    Energy Technology Data Exchange (ETDEWEB)

    Berthon-Fabry, S.; Achard, P

    2003-06-15

    The carbon aerogel is a nano-porous material at open porosity, electrical conductor. The aerogels morphology is variable in function of the different synthesis parameters. This characteristic offers to the aerogels a better adaptability to many applications: electrodes (super condensers, fuel cells). The author presents the materials elaboration and their applications. It provides also the research programs: fundamental research, realization of super-condenser electrodes, fuel cells electrodes, gas storage materials and opaque materials for thermal insulation. (A.L.B.)

  10. Ambient Dried Aerogels

    Science.gov (United States)

    Jones, Steven M.; Paik, Jong-Ah

    2013-01-01

    A method has been developed for creating aerogel using normal pressure and ambient temperatures. All spacecraft, satellites, and landers require the use of thermal insulation due to the extreme environments encountered in space and on extraterrestrial bodies. Ambient dried aerogels introduce the possibility of using aerogel as thermal insulation in a wide variety of instances where supercritically dried aerogels cannot be used. More specifically, thermoelectric devices can use ambient dried aerogel, where the advantages are in situ production using the cast-in ability of an aerogel. Previously, aerogels required supercritical conditions (high temperature and high pressure) to be dried. Ambient dried aerogels can be dried at room temperature and pressure. This allows many materials, such as plastics and certain metal alloys that cannot survive supercritical conditions, to be directly immersed in liquid aerogel precursor and then encapsulated in the final, dried aerogel. Additionally, the metalized Mylar films that could not survive the previous methods of making aerogels can survive the ambient drying technique, thus making multilayer insulation (MLI) materials possible. This results in lighter insulation material as well. Because this innovation does not require high-temperature or high-pressure drying, ambient dried aerogels are much less expensive to produce. The equipment needed to conduct supercritical drying costs many tens of thousands of dollars, and has associated running expenses for power, pressurized gasses, and maintenance. The ambient drying process also expands the size of the pieces of aerogel that can be made because a high-temperature, high-pressure system typically has internal dimensions of up to 30 cm in diameter and 60 cm in height. In the case of this innovation, the only limitation on the size of the aerogels produced would be in the ability of the solvent in the wet gel to escape from the gel network.

  11. Mill Glaze: Myth or Reality?

    Science.gov (United States)

    Mark Knaebe

    2013-01-01

    Since the mid-1980s, a condition called “mill glaze” (also called planer’s glaze) has sometimes been blamed for the failure of a coating on smooth flat-grained siding and some other wood products. The exact cause of this problem has been a subject of controversy. Many people believe that the coating fails as a result of the planing and/or drying processes. They...

  12. Aerogel nanocomposite materials

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, A.J.; Ayers, M.; Cao, W. [Lawrence Berkeley Laboratory, CA (United States)] [and others

    1995-05-01

    Aerogels are porous, low density, nanostructured solids with many unusual properties including very low thermal conductivity, good transparency, high surface area, catalytic activity, and low sound velocity. This research is directed toward developing new nanocomposite aerogel materials for improved thermal insulation and several other applications. A major focus of the research has been to further increase the thermal resistance of silica aerogel by introducing infrared opacification agents into the aerogel to produce a superinsulating composite material. Opacified superinsulating aerogel permit a number of industrial applications for aerogel-based insulation. The primary benefits from this recently developed superinsulating composite aerogel insulation are: to extend the range of applications to higher temperatures, to provide a more compact insulation for space sensitive-applications, and to lower costs of aerogel by as much as 30%. Superinsulating aerogels can replace existing CFC-containing polyurethane in low temperature applications to reduce heat losses in piping, improve the thermal efficiency of refrigeration systems, and reduce energy losses in a variety of industrial applications. Enhanced aerogel insulation can also replace steam and process pipe insulation in higher temperature applications to substantially reduce energy losses and provide much more compact insulation.

  13. Technical applications of aerogels

    International Nuclear Information System (INIS)

    Hrubesh, L.W.

    1997-01-01

    Aerogel materials posses such a wide variety of exceptional properties that a striking number of applications have developed for them. Many of the commercial applications of aerogels such as catalysts, thermal insulation, windows, and particle detectors are still under development and new application as have been publicized since the ISA4 Conference in 1994: e.g.; supercapacitors, insulation for heat storage in automobiles, electrodes for capacitive deionization, etc. More applications are evolving as the scientific and engineering community becomes familiar with the unusual and exceptional physical properties of aerogels, there are also scientific and technical application, as well. This paper discusses a variety of applications under development at Lawrence Livermore National Laboratory for which several types of aerogels are formed in custom sizes and shapes. Particular discussions will focus on the uses of aerogels for physics experiments which rely on the exceptional, sometimes unique, properties of aerogels

  14. Flexible Carbon Aerogels

    Directory of Open Access Journals (Sweden)

    Marina Schwan

    2016-09-01

    Full Text Available Carbon aerogels are highly porous materials with a large inner surface area. Due to their high electrical conductivity they are excellent electrode materials in supercapacitors. Their brittleness, however, imposes certain limitations in terms of applicability. In that context, novel carbon aerogels with varying degree of flexibility have been developed. These highly porous, light aerogels are characterized by a high surface area and possess pore structures in the micrometer range, allowing for a reversible deformation of the aerogel network. A high ratio of pore size to particle size was found to be crucial for high flexibility. For dynamic microstructural analysis, compression tests were performed in-situ within a scanning electron microscope allowing us to directly visualize the microstructural flexibility of an aerogel. The flexible carbon aerogels were found to withstand between 15% and 30% of uniaxial compression in a reversible fashion. These findings might stimulate further research and new application fields directed towards flexible supercapacitors and batteries.

  15. Polyolefin-Based Aerogels

    Science.gov (United States)

    Lee, Je Kyun; Gould, George

    2012-01-01

    An organic polybutadiene (PB) rubberbased aerogel insulation material was developed that will provide superior thermal insulation and inherent radiation protection, exhibiting the flexibility, resiliency, toughness, and durability typical of the parent polymer, yet with the low density and superior insulation properties associated with the aerogels. The rubbery behaviors of the PB rubber-based aerogels are able to overcome the weak and brittle nature of conventional inorganic and organic aerogel insulation materials. Additionally, with higher content of hydrogen in their structure, the PB rubber aerogels will also provide inherently better radiation protection than those of inorganic and carbon aerogels. Since PB rubber aerogels also exhibit good hydrophobicity due to their hydrocarbon molecular structure, they will provide better performance reliability and durability as well as simpler, more economic, and environmentally friendly production over the conventional silica or other inorganic-based aerogels, which require chemical treatment to make them hydrophobic. Inorganic aerogels such as silica aerogels demonstrate many unusual and useful properties. There are several strategies to overcoming the drawbacks associated with the weakness and brittleness of silica aerogels. Development of the flexible fiber-reinforced silica aerogel composite blanket has proven one promising approach, providing a conveniently fielded form factor that is relatively robust toward handling in industrial environments compared to silica aerogel monoliths. However, the flexible silica aerogel composites still have a brittle, dusty character that may be undesirable, or even intolerable, in certain applications. Although the cross-linked organic aerogels such as resorcinol-formaldehyde (RF), polyisocyanurate, and cellulose aerogels show very high impact strength, they are also very brittle with little elongation (i.e., less rubbery). Also, silica and carbon aerogels are less efficient

  16. Solar Glazing Tips for School Construction

    Science.gov (United States)

    Smith, Jonathan

    2012-01-01

    Glazing can be optimized to enhance passive solar heating and daylight harvesting by exceeding the prescriptive limits of the energy code. This savings can be garnered without the high cost of external overhangs or expensive glazing products. The majority of savings from solar glazing are attributable to the increase in solar heating and…

  17. Melamine-formaldehyde aerogels

    Science.gov (United States)

    Pekala, Richard Walter

    1992-01-01

    Organic aerogels that are transparent and essentially colorless are prepa from the aqueous, sol-gel polymerization of melamine with formaldehyde. The melamine-formaldehyde (MF) aerogels have low densities, high surface areas, continuous porsity, ultrafine cell/pore sizes, and optical clarity.

  18. Aerogel / Polymer Composite Materials

    Science.gov (United States)

    Williams, Martha K. (Inventor); Smith, Trent M. (Inventor); Fesmire, James E. (Inventor); Roberson, Luke B. (Inventor); Clayton, LaNetra M. (Inventor)

    2017-01-01

    The invention provides new composite materials containing aerogels blended with thermoplastic polymer materials at a weight ratio of aerogel to thermoplastic polymer of less than 20:100. The composite materials have improved thermal insulation ability. The composite materials also have better flexibility and less brittleness at low temperatures than the parent thermoplastic polymer materials.

  19. Silica aerogel Cerenkov counter

    International Nuclear Information System (INIS)

    Yasumi, S.; Masaike, A.; Yamamoto, A.; Yoshimura, Y.; Kawai, H.

    1984-03-01

    In order to obtain silica aerogel radiators of good quality, the prescription used by Saclay group has been developed. We have done several experiments using beams from KEK.PS to test the performance of a Cerenkov counter with aerogel modules produced in KEK. It turned out that these modules had excellent quality. The production rate of silica aerogel in KEK is 15 -- 20 litres a week. Silica aerogel modules of 20 x 10 x 3 cm 3 having the refractive index of 1.058 are successfully being used by Kyoto University group in the KEK experiment E92 (Σ). Methodes to produce silica aerogel with higher refractive index than 1.06 has been investigated both by heating an module with the refractive index of 1.06 and by hydrolyzing tetraethyl silicate. (author)

  20. Epoxy Crosslinked Silica Aerogels (X-Aerogels)

    Science.gov (United States)

    fabrizio, Eve; Ilhan, Faysal; Meador, Mary Ann; Johnston, Chris; Leventis, Nicholas

    2004-01-01

    NASA is interested in the development of strong lightweight materials for the dual role of thermal insulator and structural component for space vehicles; freeing more weight for useful payloads. Aerogels are very-low density materials (0.010 to 0.5 g/cc) that, due to high porosity (meso- and microporosity), can be, depending on the chemical nature of the network, ideal thermal insulators (thermal conductivity approx. 15 mW/mK). However, aerogels are extremely fragile. For practical application of aerogels, one must increase strength without compromising the physical properties attributed to low density. This has been achieved by templated growth of an epoxy polymer layer that crosslinks the "pearl necklace" network of nanoparticles: the framework of a typical silica aerogel. The requirement for conformal accumulation of the epoxy crosslinker is reaction both with the surface of silica and with itself. After cross-linking, the strength of a typical aerogel monolith increases by a factor of 200, in the expense of only a 2-fold increase in density. Strength is increased further by coupling residual unreacted epoxides with diamine.

  1. Climate and energy use in glazed spaces

    Energy Technology Data Exchange (ETDEWEB)

    Wall, M.

    1996-11-01

    One objective of the thesis has been to elucidate the relationship between building design and the climate, thermal comfort and energy requirements in different types of glazed spaces. Another object has been to study the effect of the glazed spaces on energy requirements in adjacent buildings. It has also been the object to develop a simple calculation method for the assessment of temperatures and energy requirements in glazed spaces. The research work has mainly comprised case studies of existing buildings with glazed spaces and energy balance calculations using both the developed steady-state method and a dynamic building energy simulation program. Parameters such as the geometry of the building, type of glazing, orientation, thermal inertia, airtightness, ventilation system and sunshades have been studied. These parameters are of different importance for each specific type of glazed space. In addition, the significance of each of these parameters varies for different types of glazed spaces. The developed calculation method estimates the minimum and mean temperature in glazed spaces and the energy requirements for heating and cooling. The effect of the glazed space on the energy requirement of the surrounding buildings can also be estimated. It is intended that the method should be applied during the preliminary design stage so that the effect which the design of the building will have on climate and energy requirement may be determined. The method may provide an insight into how glazed spaces behave with regard to climate and energy. 99 refs

  2. Highly stretchable carbon aerogels.

    Science.gov (United States)

    Guo, Fan; Jiang, Yanqiu; Xu, Zhen; Xiao, Youhua; Fang, Bo; Liu, Yingjun; Gao, Weiwei; Zhao, Pei; Wang, Hongtao; Gao, Chao

    2018-02-28

    Carbon aerogels demonstrate wide applications for their ultralow density, rich porosity, and multifunctionalities. Their compressive elasticity has been achieved by different carbons. However, reversibly high stretchability of neat carbon aerogels is still a great challenge owing to their extremely dilute brittle interconnections and poorly ductile cells. Here we report highly stretchable neat carbon aerogels with a retractable 200% elongation through hierarchical synergistic assembly. The hierarchical buckled structures and synergistic reinforcement between graphene and carbon nanotubes enable a temperature-invariable, recoverable stretching elasticity with small energy dissipation (~0.1, 100% strain) and high fatigue resistance more than 10 6 cycles. The ultralight carbon aerogels with both stretchability and compressibility were designed as strain sensors for logic identification of sophisticated shape conversions. Our methodology paves the way to highly stretchable carbon and neat inorganic materials with extensive applications in aerospace, smart robots, and wearable devices.

  3. Development of ceramic glaze with photocatalytic activity

    International Nuclear Information System (INIS)

    Tezza, V.B.; Uggioni, E.; Carrera, A.A. Duran; Bernardin, A.M.

    2011-01-01

    Glazes were developed by adding anatase in commercial ceramic plates as an agent of photocatalysis. The glazes were coated on ceramic tiles, which were fired between 800 and 1000°C. The formulations were characterized (SEM, XRD), and the wettability was determined by measuring the water contact angle. The microstructural analysis (SEM) showed that the anatase particles can disperse properly in the glaze matrix. The X-ray diffraction shows that from 1000°C, the glaze becomes very reactive, and particles of anatase are transformed into titanite or rutile, depending on the glaze used. The determination of the contact angle shows the clear influence of the glaze type and sintering temperature on the wettability characteristics of the obtained layer. (author)

  4. Retrofit electrochromic glazing in a UK office

    Directory of Open Access Journals (Sweden)

    Ruth Kelly Waskett

    2014-12-01

    Full Text Available Electrochromic (EC glazing is now considered a viable alternative to fixed transmittance glazing. It has the potential to enable occupants to control daylight glare and solar heat gain without the use of blinds or external shading devices, giving users more access to daylight with all its inherent benefits. Furthermore, EC glazing can reduce energy consumption by decreasing cooling loads and electric lighting usage. Most research to date has studied the effects of EC glazing in scale models, computer simulations and full scale test rooms, and some of these studies have included human participants. However, there is a general lack of understanding regarding the performance and suitability of EC glazing in real-world working environments. A case study of the first UK retrofit application of EC glazing is being conducted in two adjacent offices in a university campus building. The offices are occupied by administration staff and have large southeastfacing windows. The existing double glazed units were replaced with commercially-available EC glazed units in 2012. Over a period of more than 18 months, the rooms were monitored intensively to record the effect of the EC glazing on both the physical room environment and the occupants themselves. A large amount of data from the monitoring programme is currently undergoing detailed analysis. Initial findings emerging from the installation and post-installation period are described in this paper.

  5. Establishing the value of advanced glazings

    Energy Technology Data Exchange (ETDEWEB)

    Lee, E; Selkowitz, S.

    1999-01-01

    Numerous glazing technologies are under development worldwide to improve the performance of building facades. High-performance glazings can provide substantial energy and related environmental benefits, but often at greatly increased first cost when compared to conventional design solutions. To increase market viability, we discuss strategies to reduce the actual and owner-perceived costs associated with developing and producing advanced window systems, specifically switchable electrochromic glazings, and we also suggest marketing strategies designed to appeal to early adopter and mainstream purchasers. These strategies may be applicable to a broad range of advanced glazing materials.

  6. Zirconia-based colors for ceramic glazes

    International Nuclear Information System (INIS)

    Eppler, R.A.

    1977-01-01

    The history of color development for use in ceramic glazes is outlined. The most significant modern development is based on zirconia and zircon. These materials have gained increasing acceptance in the industry since their introduction in the late 1950's and early 1960's, due to their superior stability during firing of the glaze

  7. Mathematical modeling of optical glazing performance

    NARCIS (Netherlands)

    Nijnatten, van P.A.; Wittwer, V.; Granqvist, C.G.; Lampert, C.M.

    1994-01-01

    Mathematical modelling can be a powerful tool in the design and optimalization of glazing. By calculation, the specifications of a glazing design and the optimal design parameters can be predicted without building costly prototypes first. Furthermore, properties which are difficult to measure, like

  8. Topographic characterization of glazed surfaces

    International Nuclear Information System (INIS)

    Froeberg, Linda; Hupa, Leena

    2008-01-01

    Detailed characterization of surface microstructure, i.e. phase composition and surface geometry, has become an important criterion of glazed ceramics. Topographic characterization is an important parameter in, e.g. estimating the influence of additional films on the average roughness of a surface. Also, the microscaled and nanoscaled roughnesses correlate with the cleanability and the self-cleaning properties of the surfaces. In this work the surface geometry of several matte glazes were described by topography and roughness as given by whitelight confocal microscopy and atomic force microscopy. Different measuring parameters were compared to justify the usefulness of the techniques in giving a comprehensive description of the surface microstructure. The results suggest that confocal microscopy is well suited for giving reliable topographical parameters for matte surfaces with microscaled crystals in the surfaces. Atomic force microscopy was better suited for smooth surfaces or for describing the local topographic parameters of closely limited areas, e.g. the surroundings of separate crystals in the surface

  9. Topographic characterization of glazed surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Froeberg, Linda [Process Chemistry Centre, Abo Akademi University, FI-20500 Turku (Finland)], E-mail: lfroberg@abo.fi; Hupa, Leena [Process Chemistry Centre, Abo Akademi University, FI-20500 Turku (Finland)

    2008-01-15

    Detailed characterization of surface microstructure, i.e. phase composition and surface geometry, has become an important criterion of glazed ceramics. Topographic characterization is an important parameter in, e.g. estimating the influence of additional films on the average roughness of a surface. Also, the microscaled and nanoscaled roughnesses correlate with the cleanability and the self-cleaning properties of the surfaces. In this work the surface geometry of several matte glazes were described by topography and roughness as given by whitelight confocal microscopy and atomic force microscopy. Different measuring parameters were compared to justify the usefulness of the techniques in giving a comprehensive description of the surface microstructure. The results suggest that confocal microscopy is well suited for giving reliable topographical parameters for matte surfaces with microscaled crystals in the surfaces. Atomic force microscopy was better suited for smooth surfaces or for describing the local topographic parameters of closely limited areas, e.g. the surroundings of separate crystals in the surface.

  10. Coated Aerogel Beads

    Science.gov (United States)

    Littman, Howard (Inventor); Plawsky, Joel L. (Inventor); Paccione, John D. (Inventor)

    2014-01-01

    Methods and apparatus for coating particulate material are provided. The apparatus includes a vessel having a top and a bottom, a vertically extending conduit having an inlet in the vessel and an outlet outside of the vessel, a first fluid inlet in the bottom of the vessel for introducing a transfer fluid, a second fluid inlet in the bottom of the vessel for introducing a coating fluid, and a fluid outlet from the vessel. The method includes steps of agitating a material, contacting the material with a coating material, and drying the coating material to produce a coated material. The invention may be adapted to coat aerogel beads, among other materials. A coated aerogel bead and an aerogel-based insulation material are also disclosed.

  11. Aerogel for FARICH detector

    Energy Technology Data Exchange (ETDEWEB)

    Barnyakov, A.Yu. [Budker Institute of Nuclear Physics, Lavrentieva 11, Novosibirsk 630090 (Russian Federation); Barnyakov, M.Yu. [Budker Institute of Nuclear Physics, Lavrentieva 11, Novosibirsk 630090 (Russian Federation); Novosibirsk State Technical University, Karl Marks 20, Novosibirsk 630073 (Russian Federation); Bobrovnikov, V.S.; Buzykaev, A.R.; Gulevich, V.V. [Budker Institute of Nuclear Physics, Lavrentieva 11, Novosibirsk 630090 (Russian Federation); Danilyuk, A.F. [Boreskov Institute of Catalysis, Lavrentieva 5, Novosibirsk 630090 (Russian Federation); Kononov, S.A.; Kravchenko, E.A. [Budker Institute of Nuclear Physics, Lavrentieva 11, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, Pirogova 2, Novosibirsk 630090 (Russian Federation); Kuyanov, I.A. [Budker Institute of Nuclear Physics, Lavrentieva 11, Novosibirsk 630090 (Russian Federation); Lopatin, S.A. [Boreskov Institute of Catalysis, Lavrentieva 5, Novosibirsk 630090 (Russian Federation); Onuchin, A.P.; Ovtin, I.V.; Podgornov, N.A. [Budker Institute of Nuclear Physics, Lavrentieva 11, Novosibirsk 630090 (Russian Federation); Novosibirsk State Technical University, Karl Marks 20, Novosibirsk 630073 (Russian Federation); Porosev, V.V. [Budker Institute of Nuclear Physics, Lavrentieva 11, Novosibirsk 630090 (Russian Federation); Predein, A.Yu.; Protsenko, R.S. [Boreskov Institute of Catalysis, Lavrentieva 5, Novosibirsk 630090 (Russian Federation)

    2014-12-01

    We present our current experience in preparation of focusing aerogels for the Focusing Aerogel RICH detector. Multilayer focusing aerogel tiles have been produced in Novosibirsk by a collaboration of the Budker Institute of Nuclear Physics and Boreskov Institute of Catalysis since 2004. We have obtained 2–3–4-layer blocks with the thickness of 30–45 mm. In 2012, the first samples of focusing blocks with continuous density (refractive index) gradient along thickness were produced. This technology can significantly reduce the contribution from the geometric factor of the radiator thickness to the resolution of the measured Cherenkov angle in the FARICH detector. The special installation was used for automatic control of reagents ratio during the synthesis process. The first samples were tested using the digital radiography method and on the electron beam with the FARICH prototype.

  12. Hurricane Evacuation Routes

    Data.gov (United States)

    Department of Homeland Security — Hurricane Evacuation Routes in the United States A hurricane evacuation route is a designated route used to direct traffic inland in case of a hurricane threat. This...

  13. Aerogels in Chemical Engineering: Strategies Toward Tailor-Made Aerogels.

    Science.gov (United States)

    Smirnova, Irina; Gurikov, Pavel

    2017-06-07

    The present review deals with recent advances in the rapidly growing field of aerogel research and technology. The major focus of the review lies in approaches that allow tailoring of aerogel properties to meet application-driven requirements. The decisive properties of aerogels are discussed with regard to existing and potential application areas. Various tailoring strategies, such as modulation of the pore structure, coating, surface modification, and post-treatment, are illustrated by results of the last decade. In view of commercialization of aerogel-based products, a panorama of current industrial aerogel suppliers is given, along with a discussion of possible alternative sources for raw materials and precursors. Finally, growing points and perspectives of the aerogel field are summarized.

  14. Ancient Wall Tiles – The Importance of the Glaze/Ceramic Interface in Glaze Detachment

    Directory of Open Access Journals (Sweden)

    Marisa COSTA

    2014-04-01

    Full Text Available One of the most severe pathologies suffered by early industrially produced tiles in Portugal in late nineteenth century is glaze detachment in wall tiles placed in the lower part of the façade. It is known that salts crystallize provoking the glaze detachment, destroying the waterproofing and the beauty of the wall tile and this is one of the crucial factors towards this occurrence. The present work questions the importance of the thickness of glaze/ceramic body interface, in what concerns glaze detachment provoked by salt crystallization. SEM-EDS was used to perform all the observations that lead to the conclusion that the exuberance of the interface between glaze and ceramic body has no influence in the resistance of the glaze to salt crystallization though time, being the porous network more determinant. DOI: http://dx.doi.org/10.5755/j01.ms.20.1.3815

  15. Mechanically Strong, Polymer Cross-linked Aerogels (X-Aerogels)

    Science.gov (United States)

    Leventis, Nicholas

    2006-01-01

    Aerogels comprise a class of low-density, high porous solid objects consisting of dimensionally quasi-stable self-supported three-dimensional assemblies of nanoparticles. Aerogels are pursued because of properties above and beyond those of the individual nanoparticles, including low thermal conductivity, low dielectric constant and high acoustic impedance. Possible applications include thermal and vibration insulation, dielectrics for fast electronics, and hosting of functional guests for a wide variety of optical, chemical and electronic applications. Aerogels, however, are extremely fragile materials, hence they have found only limited application in some very specialized environments, for example as Cerenkov radiation detectors in certain types of nuclear reactors, aboard spacecraft as collectors of hypervelocity particles (refer to NASA's Stardust program) and as thermal insulators on planetary vehicles on Mars (refer to Sojourner Rover in 1997 and Spirit and Opportunity in 2004). Along these lines, the X-Aerogel is a new NASA-developed strong lightweight material that has resolved the fragility problem of traditional (native) aerogels. X-Aerogels are made by applying a conformal polymer coating on the surfaces of the skeletal nanoparticles of native aerogels (see Scanning Electron Micrographs). Since the relative amounts of the polymeric crosslinker and the backbone are comparable, X-Aerogels can be viewed either as aerogels modified by the templated accumulation of polymer on the skeletal nanoparticles, or as nanoporous polymers made by remplated casting of polymer on a nanostructured framework. The most striking feature of X-Aerogels is that for a nominal 3-fold increase in density (still a ultralighweight material), the mechanical strength can be up to 300 times higher than the strength of the underlying native aerogel. Thus, X-Aerogels combine a multiple of the specific compressive strength of steel, with the the thermal conductivity of styrofoam. X-Aerogels

  16. Evacuation of Children

    DEFF Research Database (Denmark)

    Larusdottir, Aldis Run

    is to provide new data and information on children’s evacuation, which is a step towards including children in evacuation models and calculations. Little is known about children’s evacuation characteristics in fire compared to other parts of the population. In recent years there has been more focus on children’s...... evacuation which is reflected in a rising number of publications on the topic. This thesis comprises evacuation experiments in daycares for children 0-6 years old and elementary schools for children aged 6-15 years. Full scale evacuations were filmed allowing detailed data analysis. Findings and results...... to isolate single factors and findings. Although an engineering approach fits best to the measurable parameters, the other areas are at least equally important when investigating or predicting children’s evacuation. The key findings of the thesis are: Children are very dependent on adults for initiating...

  17. Aerogels in Aerospace: An Overview

    Directory of Open Access Journals (Sweden)

    Nadiir Bheekhun

    2013-01-01

    Full Text Available Aerogels are highly porous structures prepared via a sol-gel process and supercritical drying technology. Among the classes of aerogels, silica aerogel exhibits the most remarkable physical properties, possessing lower density, thermal conductivity, refractive index, and dielectric constant than any solids. Its acoustical property is such that it can absorb the sound waves reducing speed to 100 m/s compared to 332 m/s for air. However, when it comes to commercialization, the result is not as expected. It seems that mass production, particularly in the aerospace industry, has dawdled behind. This paper highlights the evolution of aerogels in general and discusses the functions and significances of silica aerogel in previous astronautical applications. Future outer-space applications have been proposed as per the current research trend. Finally, the implementation of conventional silica aerogel in aeronautics is argued with an alternative known as Maerogel.

  18. Advanced connection systems for architectural glazing

    CERN Document Server

    Afghani Khoraskani, Roham

    2015-01-01

    This book presents the findings of a detailed study to explore the behavior of architectural glazing systems during and after an earthquake and to develop design proposals that will mitigate or even eliminate the damage inflicted on these systems. The seismic behavior of common types of architectural glazing systems are investigated and causes of damage to each system, identified. Furthermore, depending on the geometrical and structural characteristics, the ultimate horizontal load capacity of glass curtain wall systems is defined based on the stability of the glass components. Detailed attention is devoted to the incorporation of advanced connection devices between the structure of the building and the building envelope system in order to minimize the damage to glazed components. An innovative new connection device is introduced that results in a delicate and functional system easily incorporated into different architectural glazing systems, including those demanding maximum transparency.

  19. Analytical investigations of glazed Islamic pottery

    International Nuclear Information System (INIS)

    Pernicka, E.; Krejsa, P.

    1977-11-01

    The composition of the glazes of 14 fragments of medieval ceramics from Sistan in the south-west of Afghanistan has been determined quantitatively by means of electron probe microanalysis. The results were compared with materials and recipes, which are described in a Persian treatise on the manufacutre of glazed ceramic objects dated 1300 A.D. The mineral ''muzzarad'' which was used for the black underglaze painting, could be identified as chromite. The light blue colouring of the glaze was accomplished by admixtue of Cu, while Co was used for the dark blue painting. Most probably the Co pigment originated from Kashan in Persia. Only two glazes Pb was found, one of which contained also Sn. Based on the results of the quantitative analyses, a frit composition was calculated, which agrees with the medieval description of one identifies another so far unknown material mentioned in the treatise (qamsari) as dolomitic sandstone. (author)

  20. Photoactive glazed polymer-cement composite

    Science.gov (United States)

    Baltes, Liana; Patachia, Silvia; Tierean, Mircea; Ekincioglu, Ozgur; Ozkul, Hulusi M.

    2018-04-01

    Macro defect free cements (MDF), a kind of polymer-cement composites, are characterized by remarkably high mechanical properties. Their flexural strengths are 20-30 times higher than those of conventional cement pastes, nearly equal to that of an ordinary steel. The main drawback of MDF cements is their sensitivity to water. This paper presents a method to both diminish the negative impact of water on MDF cements mechanical properties and to enlarge their application by conferring photoactivity. These tasks were solved by glazing MDF cement with an ecological glaze containing nano-particles of TiO2. Efficiency of photocatalytic activity of this material was tested against methylene blue aqueous solution (4.4 mg/L). Influence of the photocatalyst concentration in the glaze paste and of the contact time on the photocatalysis process (efficiency and kinetic) was studied. The best obtained photocatalysis yield was of 97.35%, after 8 h of exposure to 254 nm UV radiation when used an MDF glazed with 10% TiO2 in the enamel paste. Surface of glazed material was characterized by optic microscopy, scratch test, SEM, XRD, and EDS. All these properties were correlated with the aesthetic aspect of the glazed surface aiming to propose using of this material for sustainable construction development.

  1. Large Scale Glazed Concrete Panels

    DEFF Research Database (Denmark)

    Bache, Anja Margrethe

    2010-01-01

    Today, there is a lot of focus on concrete surface’s aesthitic potential, both globally and locally. World famous architects such as Herzog De Meuron, Zaha Hadid, Richard Meyer and David Chippenfield challenge the exposure of concrete in their architecture. At home, this trend can be seen...... in the crinkly façade of DR-Byen (the domicile of the Danish Broadcasting Company) by architect Jean Nouvel and Zaha Hadid’s Ordrupgård’s black curved smooth concrete surfaces. Furthermore, one can point to initiatives such as “Synlig beton” (visible concrete) that can be seen on the website www.......synligbeton.dk and spæncom’s aesthetic relief effects by the designer Line Kramhøft (www.spaencom.com). It is my hope that the research-development project “Lasting large scale glazed concrete formwork,” I am working on at DTU, department of Architectural Engineering will be able to complement these. It is a project where I...

  2. Protective Skins for Aerogel Monoliths

    Science.gov (United States)

    Leventis, Nicholas; Johnston, James C.; Kuczmarski, Maria A.; Meador, Ann B.

    2007-01-01

    A method of imparting relatively hard protective outer skins to aerogel monoliths has been developed. Even more than aerogel beads, aerogel monoliths are attractive as thermal-insulation materials, but the commercial utilization of aerogel monoliths in thermal-insulation panels has been inhibited by their fragility and the consequent difficulty of handling them. Therefore, there is a need to afford sufficient protection to aerogel monoliths to facilitate handling, without compromising the attractive bulk properties (low density, high porosity, low thermal conductivity, high surface area, and low permittivity) of aerogel materials. The present method was devised to satisfy this need. The essence of the present method is to coat an aerogel monolith with an outer polymeric skin, by painting or spraying. Apparently, the reason spraying and painting were not attempted until now is that it is well known in the aerogel industry that aerogels collapse in contact with liquids. In the present method, one prevents such collapse through the proper choice of coating liquid and process conditions: In particular, one uses a viscous polymer precursor liquid and (a) carefully controls the amount of liquid applied and/or (b) causes the liquid to become cured to the desired hard polymeric layer rapidly enough that there is not sufficient time for the liquid to percolate into the aerogel bulk. The method has been demonstrated by use of isocyanates, which, upon exposure to atmospheric moisture, become cured to polyurethane/polyurea-type coats. The method has also been demonstrated by use of commercial epoxy resins. The method could also be implemented by use of a variety of other resins, including polyimide precursors (for forming high-temperature-resistant protective skins) or perfluorinated monomers (for forming coats that impart hydrophobicity and some increase in strength).

  3. Next generation structural silicone glazing

    Directory of Open Access Journals (Sweden)

    Charles D. Clift

    2015-06-01

    Full Text Available This paper presents an advanced engineering evaluation, using nonlinear analysis of hyper elastic material that provides significant improvement to structural silicone glazing (SSG design in high performance curtain wall systems. Very high cladding wind pressures required in hurricane zones often result in bulky SSG profile dimensions. Architectural desire for aesthetically slender curtain wall framing sight-lines in combination with a desire to reduce aluminium usage led to optimization of silicone material geometry for better stress distribution.To accomplish accurate simulation of predicted behaviour under structural load, robust stress-strain curves of the silicone material are essential. The silicone manufacturer provided physical property testing via a specialized laboratory protocol. A series of rigorous curve fit techniques were then made to closely model test data in the finite element computer analysis that accounts for nonlinear strain of hyper elastic silicone.Comparison of this advanced design technique to traditional SSG design highlights differences in stress distribution contours in the silicone material. Simplified structural engineering per the traditional SSG design method does not provide accurate forecasting of material and stress optimization as shown in the advanced design.Full-scale specimens subject to structural load testing were performed to verify the design capacity, not only for high wind pressure values, but also for debris impact per ASTM E1886 and ASTM E1996. Also, construction of the test specimens allowed development of SSG installation techniques necessitated by the unique geometry of the silicone profile. Finally, correlation of physical test results with theoretical simulations is made, so evaluation of design confidence is possible. This design technique will introduce significant engineering advancement to the curtain wall industry.

  4. Auditory evacuation beacons

    NARCIS (Netherlands)

    Wijngaarden, S.J. van; Bronkhorst, A.W.; Boer, L.C.

    2005-01-01

    Auditory evacuation beacons can be used to guide people to safe exits, even when vision is totally obscured by smoke. Conventional beacons make use of modulated noise signals. Controlled evacuation experiments show that such signals require explicit instructions and are often misunderstood. A new

  5. Optimal crowd evacuation

    NARCIS (Netherlands)

    Hoogendoorn, S.P.; Daamen, W.; Duives, D.C.; Van Wageningen-Kessels, F.L.M.

    2013-01-01

    This paper deals with the optimal allocation of routes, destination, and departure times to members of a crowd, for instance in case of an evacuation or another hazardous situation in which the people need to leave the area as quickly as possible. The generic approach minimizes the evacuation times,

  6. Effect of window glazing on colour quality of transmitted daylight

    NARCIS (Netherlands)

    Dangol, R.; Kruisselbrink, T.W.; Rosemann, A.L.P.

    2017-01-01

    In this study, the colour quality of the daylight transmitted through different window glazing types is evaluated. The analysis considered four different types of window glazing: laminated, monolithic, coated and applied film glazing ranging in luminous transmittance from around 0.97 to <0.1. The

  7. Aerogels: II. Applications in catalysis

    Directory of Open Access Journals (Sweden)

    Orlović Aleksandar M.

    2002-01-01

    Full Text Available Sol-gel synthesis, and the resulting materials (xerogels and aerogels are finding increasing application in the synthesis of catalysts, due to their unique characteristics. The most important features of the sol-gel process are: the ability to achieve homogeneity at the molecular level, the introduction of several species in only one step and the ability to stabilize metastable phases. The supercritical drying process produces aerogels with structural features quite different to conventional materials. Some of these characteristics of aerogels can make them very effective catalysts.

  8. Evacuation dynamics of children

    DEFF Research Database (Denmark)

    Larusdottir, Aldis Run; Dederichs, Anne

    2010-01-01

    higher walking speeds in spiral stairs when the children are familiar with the evacuation path. Higher per-son densities and faster flow through doors were obtained among the children than found in literature on adults. Children in the younger age group are generally slower than the older children....... The children walk slower in horizontal plan than adults, however they are keen to run during evacuations, in the latter case their travel speed increases and exceeds the adults’. Since the evacuation characte-ristics of children differ in many ways from those of adults, nowadays models badly comprehend...

  9. Dynamics of capillary condensation in aerogels.

    Science.gov (United States)

    Nomura, R; Miyashita, W; Yoneyama, K; Okuda, Y

    2006-03-01

    Dynamics of capillary condensation of liquid 4He in various density silica aerogels was investigated systematically. Interfaces were clearly visible when bulk liquid was rapidly sucked into the aerogel. Time evolution of the interface positions was consistent with the Washburn model and their effective pore radii were obtained. Condensation was a single step in a dense aerogel and two steps in a low density aerogel. Crossover between the two types of condensation was observed in an intermediate density aerogel. Variety of the dynamics may be the manifestation of the fractal nature of aerogels which had a wide range of distribution of pore radii.

  10. Vacuum window glazings for energy-efficient buildings

    Energy Technology Data Exchange (ETDEWEB)

    Benson, D.K.; Smith, L.K.; Tracy, C.E.; Potter, T.; Christensen, C. (Solar Energy Research Inst., Golden, CO (USA)); Soule, D.E. (Western Illinois Univ., Macomb, IL (USA))

    1990-05-01

    The technical feasibility of a patented, laser-welded, evacuated insulating window was studied. The window has two edge-sealed sheets of glass separated by 0.5-mm glass spheres spaced 30 mm apart in a regular array. A highly insulating frame is required and several designs were analyzed. The vacuum window's combination of high solar transmittance and low thermal conductance makes it superior to many other windows in cold climates. In the US Pacific Northwest, the vacuum window could save about 6 MJ of heating energy annually per square meter of window in comparison to conventional, double-glazed windows. A large, vacuum laser-welding facility was designed and installed to conduct glass welding experiments and to fabricate full-sized vacuum windows. Experiments confirmed the feasibility of laser-sealing glass in vacuum but identified two difficulties. Under some circumstances, bubbles of dissolved gases form during welding and weaken the seal. Glass also vaporizes and contaminates the laser beam steering mirror. A novel moving metal foil mirror was developed to circumvent the contamination problem, but it has not yet been used to complete welding experiments and fabricate full-sized vacuum windows. 63 refs., 53 figs., 19 tabs.

  11. Glazed Tiles as Floor Finish in Nigeria

    Directory of Open Access Journals (Sweden)

    Toyin Emmanuel AKINDE

    2013-09-01

    Full Text Available Tile is no doubt rich in antiquity; its primordial  show, came as mosaic with primary prospect in sacred floor finish before its oblivion, courtesy of, later consciousness towards wall finish in banquets, kitchens, toilets, restaurants and even bars. Today, its renaissance as floor finish is apparent in private and public architectural structures with prevalence in residential, recreational, commercial, governmental and other spaces. In Nigeria, the use of glazed tiles as floor finish became apparent, supposedly in mid-twentieth century; and has since, witnessed ever increasing demands from all sundry; a development that is nascent and has necessitated its mass  production locally with pockets of firms in the country. The latter however, is a resultant response to taste cum glazed tiles affordability, whose divergent sophistication in design, colour, size and shape is believed preferred to terrazzo, carpet and floor flex tile. Accessible as glazed tile and production is, in recent times; its dearth of a holistic literature in Nigeria is obvious. In the light of the latter, this paper examine glazed tiles as floor finish in Nigeria, its advent, usage, production, challenge, benefit and prospect with the hope of opening further frontier in discipline specifics.

  12. A systematization of glaze spalling in azulejos

    Directory of Open Access Journals (Sweden)

    João Manuel Mimoso

    2016-01-01

    Full Text Available The detachment of the glaze in azulejos is the ultimate form of decay, since it leads to the loss of the pictorial content. The detachment is usually considered in a diffuse way, however a close observation allows recognizing several types, often related to crazing, which this paper proposes to systematize.

  13. 49 CFR 238.421 - Glazing.

    Science.gov (United States)

    2010-10-01

    ... in this paragraph; (ii) The name of the manufacturer; and (iii) The type or brand identification of...; and (C) The type or brand identification of the material. (d) Glazing securement. Each exterior window... words conveying that meaning, in letters at least 3/8 of an inch high. [64 FR 25660, May 12, 1999, as...

  14. Simulated Evacuations Into Water

    National Research Council Canada - National Science Library

    McLean, Garnet

    2004-01-01

    .... Actual emergency data to support ditching certification are not available; there have been questions as to whether evacuation flow rates onto land are appropriate for use in ditching-related flotation time computations...

  15. Feasibility of evacuation

    International Nuclear Information System (INIS)

    1988-01-01

    The main question is whether evacuation of people is feasible in case of accidents with a nuclear power plant. The limiting conditions of this question are extracted from other studies. This study is therefore focused on a postulated accident in a newly built nuclear power plant with an electric capacity of 1000 Megawatt and a source term of one percent. In this particular case an evacuation should take place within the period between the accident and the emission of nuclear materials. Initial focus is on the administrative-organizational aspects of evacuation. Then bottlenecks in the technical implementation of evacuation are determined. An analysis is made for each potential Dutch location (Borssele, Eemshaven, Maasvlakte, Moerdijk and Westelijke Noordoostpolderdijk) of a nuclear power plant. By means of a model the following question is examined: can the population leave the danger area or be evacuated on time, under certain circumstances. It is concluded that preventive evacuation of the population from the planned locations is feasible, but at Moerdijk complications may occur because of the presence of some homes for the elderly and a nursing home. 18 refs.; 7 figs.; 2 tabs

  16. THE EFFECT OF OPACIFIERS ON SURFACE ROUGHNESS OFCERAMIC GLAZES

    Directory of Open Access Journals (Sweden)

    R. Sarjahani

    2016-03-01

    Full Text Available Surface smoothness of ceramic glazes is always an important characteristic of ceramic glazes as a point of surface engineering studies. Surface roughness affects chemical resistivity, glossiness and stainabiliy of glazes. In fact, less surface roughness improves cleanability of the surface by the least usage amount of detergents. In this investigation, surface topography of two common opaque glazes, zirconia and titania-based, has been investigated. Crystallinity of the surface has been studied from SEM images, and comparison of EDS elemental results with phase analysis results of XRD. Surface roughness profile measured by Marsurf M300, shows that titania-based glaze is almost 24% percentage more smooth than zirconia based glaze. Surface smoothness is in relation with crystallinity of glaze surface, crystal type and crystal distribution in amorphous matrix phase

  17. Refractive index dispersion law of silica aerogel

    International Nuclear Information System (INIS)

    Bellunato, T.; Calvi, M.; Matteuzzi, C.; Musy, M.; Perego, D.L.; Storaci, B.

    2007-01-01

    This paper presents measurements of the refractive index of a hygroscopic silica aerogel block at several wavelengths. The measurements, performed with a monochromator, have been compared with different parameterisations for n(λ), in order to determine the best chromaticity law for the aerogel. This is an important input for design and operation of RICH detectors with silica aerogel radiator. (orig.)

  18. Polyurea-Based Aerogel Monoliths and Composites

    Science.gov (United States)

    Lee, Je Kyun

    2012-01-01

    aerogel insulation material was developed that will provide superior thermal insulation and inherent radiation protection for government and commercial applications. The rubbery polyureabased aerogel exhibits little dustiness, good flexibility and toughness, and durability typical of the parent polyurea polymer, yet with the low density and superior insulation properties associated with aerogels. The thermal conductivity values of polyurea-based aerogels at lower temperature under vacuum pressures are very low and better than that of silica aerogels. Flexible, rubbery polyurea-based aerogels are able to overcome the weak and brittle nature of conventional inorganic and organic aerogels, including polyisocyanurate aerogels, which are generally prepared with the one similar component to polyurethane rubber aerogels. Additionally, with higher content of hydrogen in their structures, the polyurea rubber-based aerogels will also provide inherently better radiation protection than those of inorganic and carbon aerogels. The aerogel materials also demonstrate good hydrophobicity due to their hydrocarbon molecular structure. There are several strategies to overcoming the drawbacks associated with the weakness and brittleness of silica aerogels. Development of the flexible fiber-reinforced silica aerogel composite blanket has proven to be one promising approach, providing a conveniently fielded form factor that is relatively robust in industrial environments compared to silica aerogel monoliths. However, the flexible, silica aerogel composites still have a brittle, dusty character that may be undesirable, or even intolerable, in certain application environments. Although the cross - linked organic aerogels, such as resorcinol- formaldehyde (RF), polyisocyanurate, and cellulose aerogels, show very high impact strength, they are also very brittle with little elongation (i.e., less rubbery). Also, silica and carbon aerogels are less efficient radiation shielding materials due

  19. Indoor Climate of Large Glazed Spaces

    DEFF Research Database (Denmark)

    Hendriksen, Ole Juhl; Madsen, Christina E.; Heiselberg, Per

    In recent years large glazed spaces has found increased use both in connection with renovation of buildings and as part of new buildings. One of the objectives is to add an architectural element, which combines indoor- and outdoor climate. In order to obtain a satisfying indoor climate it is crui...... it is cruicial at the design stage to be able to predict the performance regarding thermal comfort and energy consumption. This paper focus on the practical implementation of Computational Fluid Dynamics (CFD) and the relation to other simulation tools regarding indoor climate.......In recent years large glazed spaces has found increased use both in connection with renovation of buildings and as part of new buildings. One of the objectives is to add an architectural element, which combines indoor- and outdoor climate. In order to obtain a satisfying indoor climate...

  20. Surface Abrasion of Glazed Ceramic Tiles

    Directory of Open Access Journals (Sweden)

    Esposito, L.

    2000-02-01

    Full Text Available The characteristics of the proper surface of glazed ceramic tiles have a considerable influence on their mechanical response to the various stresses coming from the environment. In this regard, one of the most important parameters to define the correct use of these products is the wear behaviour of the proper surface. Since the glaze layer is the physical interface between the environment and ceramic body, its characteristics also determine the service life of the tile. The objective of the research reported here was to assess the influence of hardness, fracture toughness and porosity of the glaze layer on the wear behaviour of the proper surface of glazed ceramic tiles. The results obtained show a clear relationship between the characteristics of the glaze layer and the material removal in the form of normalised weight loss, which can be considered a useful tool to predict the wear behaviour of these products.

    Las características de la propia superficie de los azulejos cerámicos esmaltados tiene una influencia considerable en la respuesta mecánica de éstos a las distintas tensiones provenientes del entorno. De acuerdo con esto, uno de los parámetros más importantes que definen la correcta utilización de estos productos es el comportamiento ante el desgaste de la propia superficie. Debido a que la capa de esmalte es la conexión física entre el entorno y el cuerpo cerámico, sus características también determinan vida útil del azulejo. El objetivo de la investigación de la que damos cuenta aquí fue calcular la influencia de la dureza, resistencia a la fractura y porosidad de la capa de esmalte en el comportamiento ante el desgaste de la propia superficie de los azulejos cerámicos esmaltados. Los resultados obtenidos muestran una clara relación entre las características de la capa de esmalte y la eliminación del material en forma de pérdida de peso normalizada, que puede ser considerada como una herramienta útil para

  1. Silica aerogel and space astrophysics

    International Nuclear Information System (INIS)

    Koch-Miramond, L.

    1985-09-01

    Silica aerogels have been produced in large and transparent blocks for space astrophysics experiments since the beginning of the 1970's. They were used in cosmic ray experiments on board balloons by the Saclay group. A new space venture where aerogel Cerenkov radiators will play a decisive role is currently being prepared by a large collaboration of European and US Institutes. It will be part of the so-called International Solar Polar Mission (ISPM) which will explore the heliosphere over the full range of solar latitudes from the ecliptic (equatorial) plane to the magnetic poles of the sun. Comments on properties and long term behaviour of silica aerogel cerenkov radiators in space environment are given

  2. Polyimide Cellulose Nanocrystal Composite Aerogels

    Science.gov (United States)

    Nguyen, Baochau N.; Meador, Mary Ann; Rowan, Stuart; Cudjoe, Elvis; Sandberg, Anna

    2014-01-01

    Polyimide (PI) aerogels are highly porous solids having low density, high porosity and low thermal conductivity with good mechanical properties. They are ideal for various applications including use in antenna and insulation such as inflatable decelerators used in entry, decent and landing operations. Recently, attention has been focused on stimuli responsive materials such as cellulose nano crystals (CNCs). CNCs are environmentally friendly, bio-renewable, commonly found in plants and the dermis of sea tunicates, and potentially low cost. This study is to examine the effects of CNC on the polyimide aerogels. The CNC used in this project are extracted from mantle of a sea creature called tunicates. A series of polyimide cellulose nanocrystal composite aerogels has been fabricated having 0-13 wt of CNC. Results will be discussed.

  3. Evacuating populations with special needs

    Science.gov (United States)

    2009-04-01

    Evacuation operations are conducted under the authority of, and based on decisions by, local and state authorities. The purpose of this primer, Evacuating Populations with Special Needs, is to provide local and state emergency managers, government of...

  4. Evacuation drill at CMS

    CERN Multimedia

    Niels Dupont-Sagorin and Christoph Schaefer

    2012-01-01

    Training personnel, including evacuation guides and shifters, checking procedures, improving collaboration with the CERN Fire Brigade: the first real-life evacuation drill at CMS took place on Friday 3 February from 12p.m. to 3p.m. in the two caverns located at Point 5 of the LHC.   CERN personnel during the evacuation drill at CMS. Evacuation drills are required by law and have to be organized periodically in all areas of CERN, both above and below ground. The last drill at CMS, which took place in June 2007, revealed some desiderata, most notably the need for a public address system. With this equipment in place, it is now possible to broadcast audio messages from the CMS control room to the underground areas.   The CMS Technical Coordination Team and the GLIMOS have focused particularly on preparing collaborators for emergency situations by providing training and organizing regular safety drills with the HSE Unit and the CERN Fire Brigade. This Friday, the practical traini...

  5. Use of a new borate raw material for glaze formulation

    International Nuclear Information System (INIS)

    Gomez-Tena, M. P.; Moreno, A.; Bou, E.; Cook, S.; Galindo, M.

    2010-01-01

    The Rio Tinto Minerals company has developed a new borate (E-4972), which can be used in glaze formulation (patent WO 2007/148101). This new borate, synthesised by low-temperature calcination, fundamentally contributes five oxides: silicon oxide (SiO 2 ), aluminium oxide (Al 2 O 3 ), boron oxide (B 2 O 3 ), calcium oxide (CaO), and sodium oxide (Na 2 O), its content in B 2 O 3 being between 10 and 11% by weight. It is largely amorphous, and quartz is the major crystalline phase present. The characteristics of this new borate, such as its low solubility and ability readily to form glassy phase, enable it to be used as a raw material in glaze compositions. Its suitability for glaze formulation has been the result of several years research in collaboration with the Instituto de Tecnologia Ceramica. In this paper, the feasibility has been studied of fabricating ceramic glazes by using a new synthetic borate raw material that contributes boron to the glaze composition without this needing to be done in fritted form. It has been possible to obtain fired glazes with similar technical and aesthetics characteristics to those obtained from industrial glaze compositions that contain typical frits in their compositions, thus enabling glazes to be formulated by using the new synthetic boron raw material. The results obtained show that this new raw material (E-4972) is particularly appropriate for use in producing glazes with low gloss at high temperature. (Author) 15 refs.

  6. A stationary evacuated collector with integrated concentrator

    Energy Technology Data Exchange (ETDEWEB)

    Snail, K.A.; O' Gallagher, J.J.; Winston, R.

    1984-01-01

    A comprehensive set of experimental tests and detailed optical and thermal models are presented for a newly developed solar thermal collector. The new collector has an optical efficiency of 65 per cent and achieves thermal efficiencies of better than 50 per cent at fluid temperatures of 200/sup 0/C without tracking the sun. The simultaneous features of high temperature operation and a fully stationary mount are made possible by combining vacuum insulation, spectrally selective coatings, and nonimaging concentration in a novel way. These 3 design elements are ''integrated'' together in a self containe unit by shaping the outer glass envelope of a conventional evacuated tube into the profile of a nonimaging CPC-type concentrator. This permits the use of a first surface mirror and eliminates the need for second cover glazing. The new collector has been given the name ''Integrated Stationary Evacuated Concentrator'', or ISEC collector. Not only is the peak thermal efficiency of the ISEC comparable to that of commercial tracking parabolic troughs, but projections of the average yearly energy delivery also show competitive performance with a net gain for temperatures below 200/sup 0/C. In addition, the ISEC is less subject to exposure induced degradation and could be mass produced with assembly methods similar to those used with fluorescent lamps. Since no tracking or tilt adjustments are ever required and because its sensitive optical surfaces are protected from the environment, the ISEC collector provides a simple, easily maintained solar thermal collector for the range 100-300/sup 0/C which is suitable for most climates and atmospheric conditions. Potential applications include space heating, air conditioning, and industrial process heat.

  7. Low-cost solar collectors using thin-film plastics absorbers and glazings

    Energy Technology Data Exchange (ETDEWEB)

    Wilhelm, W.G.

    1980-01-01

    The design, fabrication, performance, cost, and marketing of flat plate solar collectors using plastic absorbers and glazings are described. Manufacturing cost breakdowns are given for single-glazed and double-glazed collectors. (WHK)

  8. Behavior-based evacuation planning

    KAUST Repository

    Rodriguez, Samuel

    2010-05-01

    In this work, we present a formulation of an evacuation planning problem that is inspired by motion planning and describe an integrated behavioral agent-based and roadmap-based motion planning approach to solve it. Our formulation allows users to test the effect on evacuation of a number of different environmental factors. One of our main focuses is to provide a mechanism to investigate how the interaction between agents influences the resulting evacuation plans. Specifically, we explore how various types of control provided by a set of directing agents effects the overall evacuation planning strategies of the evacuating agents. ©2010 IEEE.

  9. Behavior-based evacuation planning

    KAUST Repository

    Rodriguez, Samuel; Amato, Nancy M

    2010-01-01

    In this work, we present a formulation of an evacuation planning problem that is inspired by motion planning and describe an integrated behavioral agent-based and roadmap-based motion planning approach to solve it. Our formulation allows users to test the effect on evacuation of a number of different environmental factors. One of our main focuses is to provide a mechanism to investigate how the interaction between agents influences the resulting evacuation plans. Specifically, we explore how various types of control provided by a set of directing agents effects the overall evacuation planning strategies of the evacuating agents. ©2010 IEEE.

  10. Influence of alumina characteristics on glaze properties

    Directory of Open Access Journals (Sweden)

    Arrufat, S.

    2010-10-01

    Full Text Available Aluminium oxide is a synthetic raw material manufactured from bauxite by the Bayer process, whose Al2O3 content typically exceeds 99%. Four main types of alumina can be defined, depending on the processing used: hydrargillite Al(OH3, boehmite AlOOH, transition aluminas (calcined at low temperatures, 1000 °C, with an intermediary crystallographic structure between hydrates and alpha alumina, and α-Al2O3 (calcined at high temperatures, >1100 °C. In glaze manufacturing, α-Al2O3 is the main type of alumina used. This raw material acts as a matting agent: the matt effect depends on alumina particle size and content in the glaze. This study examines the effect of the degree of alumina calcination on glaze technical and aesthetic properties. For this purpose, aluminas with different degrees of calcination were added to a glaze formulated with a transparent frit and kaolin, in order to simplify the system to be studied. The results show that, depending on the degree of calcination, alumina particles can react with the glaze components (SiO2, CaO, and ZnO to form new crystalline phases (anorthite and gahnite. Both crystallisations extract CaO and ZnO from the glassy phase, increasing glassy phase viscosity. The variation in crystalline phases and glassy phase viscosity yields glazes with different technical and aesthetic properties.

    El óxido de aluminio es una materia prima sintética fabricada a partir de la bauxita por medio del proceso Bayer, cuyo contenido de Al2O3 supera, por regla general, el 99%. Se pueden definir cuatro tipos de alúmina, en función del tipo de proceso usado: hidrargilita Al(OH3, boehmita AlOOH, alúminas de transición (calcinadas a bajas temperaturas, 1000 °C, con una estructura cristalográfica intermedia entre los hidratos y la alfa alúmina, y la α-Al2O3 (calcinada a

  11. Faraday rotation measurements in maghemite-silica aerogels

    International Nuclear Information System (INIS)

    Taboada, E.; Real, R.P. del; Gich, M.; Roig, A.; Molins, E.

    2006-01-01

    Faraday rotation measurements have been performed on γ-Fe 2 O 3 /SiO 2 nanocomposite aerogels which are light, porous and transparent magnetic materials. The materials have been prepared by sol-gel polymerization of a silicon alkoxide, impregnation of the intermediate silica gel with a ferrous salt and supercritical drying of the gels. During supercritical evacuation of the solvent, spherical nanoparticles of iron oxide, with a mean particle diameter of 8.1±2.0 nm, are formed and are found to be homogenously distributed within the silica matrix. The specific Faraday rotation of the composite was measured at 0.6 T using polarized light of 810 nm, being 29.6 deg./cm. The changes in the plane of polarization of the transmitted light and the magnetization of the material present similar magnetic field dependencies and are characteristic of a superparamagnetic system

  12. 77 FR 37477 - Federal Motor Vehicle Safety Standards; Glazing Materials

    Science.gov (United States)

    2012-06-21

    ... items of glazing are also defined according to their construction characteristics. For example, item 1... a boil and a bake test to determine whether safety glazing can withstand exposure to high... (150[emsp14][deg]F) water for three minutes and then placed in boiling water for three hours. The bake...

  13. 24 CFR 3280.113 - Glass and glazed openings.

    Science.gov (United States)

    2010-04-01

    ... glazing material is considered to be any glazing material capable of passing the requirements of Safety... URBAN DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Planning Considerations § 3280.113... shall meet the requirements of § 3280.403 the “Standard for Windows and Sliding Glass Doors Used in...

  14. Study on 95 alumina ceramic metallizing and glazing technique

    International Nuclear Information System (INIS)

    Zhou Qun; Wang Wei

    2007-12-01

    Electric heater is a component of pressurizer in NPP. So the connector of heater must suit for special requirement with high reliability. It need join 95% alumina ceramic and special metal together. Traditional technique is to glazing ceramic at first, then sintering metal powder on ceramic. It result in melting glaze when metallizing at high temperature. The research on high temperature glaze hasn't got ideal result. In another way, the experiments prove low temperature metallizing couldn't get enough strength. Base on present conditions, a new technique is introduced. It is first metallizing then glazing. It can not only provide high strength with high temperature metallizing , but also avoid melting glaze at high temperature. Compared with other ways, the experiments prove it is feasible. The test data can satisfy requirement. This research has been put into production. (authors)

  15. Sorption Properties of Aerogel in Liquid Nitrogen

    Science.gov (United States)

    Johnson, Wesley L.

    2006-01-01

    Aerogel products are now available as insulation materials of the future. The Cryogenics Test Laboratory at the NASA Kennedy Space Center is developing aerogel-based thermal insulation systems for space launch applications. Aerogel beads (Cabot Nanogel ) and aerogel blankets (Aspen Aerogels Spaceloft ) have outstanding ambient pressure thermal performance that makes them useful for applications where sealing is not possible. Aerogel beads are open-celled silicone dioxide and have tiny pores that run throughout the body of the bead. It has also recently been discovered that aerogel beads can be used as a filtering device for aqueous compounds at room temperature. With their hydrophobic covering, the beads absorb any non-polar substance and they can be chemically altered to absorb hot gases. The combination of the absorption and cryogenic insulating properties of aerogel beads have never been studied together. For future cryogenic insulation applications, it is crucial to know how the beads react while immersed in cryogenic liquids, most notably liquid nitrogen. Aerogel beads in loose-fill situation and aerogel blankets with composite fiber structure have been tested for absorption properties. Depending on the type of aerogel used and the preparation, preliminary results show the material can absorb up to seven times its own weight of liquid nitrogen, corresponding to a volumetric ratio of 0.70 (unit volume nitrogen per unit volume aerogel). These tests allow for an estimate on how much insulation is needed in certain situations. The theory behind the different processes of sorption is necessary for a better understanding of the preparation of the beads before they are used in an insulation system.

  16. Environmental assessment of electrochromic glazing production

    International Nuclear Information System (INIS)

    Syrrakou, E.; Papaefthimiou, S.; Yianoulis, P.

    2005-01-01

    The life cycle analysis method was used to determine the environmental impacts associated with the production of an electrochromic (EC) glazing (called ECD). This paper describes the inventory analysis for all the basic materials used during the manufacture of the ECD, i.e. K-Glass, tungsten oxide (WO 3 ), poly-methyl methacrylate (PMMA), propylene carbonate (PC), lithium perchlorate (LiClO 4 ) and acetic silicone sealant. K-Glass, PC and PMMA account for the 98% of the total device mass and the CO 2 emissions during their production processes are 810 g. The total embodied energy was estimated to be 49 MJ/ECD, with 32.1 MJ/unit of them derived from the K-Glass. The comparison of the total embodied energies of the ECD and various insulating glass units concluded that mass-produced EC glazings could easily compete with them in terms of environmental performance, anticipating cost attenuation and overall thermal and optical behavior. The above analysis could be implemented for the reduction of the embodied energy of the ECD life cycle, since it is proposed as an energy saving device. (Author)

  17. Radioactivity Measurements on Glazed Ceramic Surfaces.

    Science.gov (United States)

    Hobbs, T G

    2000-01-01

    A variety of commonly available household and industrial ceramic items and some specialty glass materials were assayed by alpha pulse counting and ion chamber voltage measurements for radioactivity concentrations. Identification of radionuclides in some of the items was performed by gamma spectroscopy. The samples included tableware, construction tiles and decorative tiles, figurines, and other products with a clay based composition. The concentrations of radioactivity ranged from near background to about four orders of magnitude higher. Almost every nuclide identification test demonstrated some radioactivity content from one or more of the naturally occurring radionuclide series of thorium or uranium. The glazes seemed to contribute most of the activity, although a sample of unglazed pottery greenware showed some activity. Samples of glazing paints and samples of deliberately doped glass from the World War II era were included in the test, as was a section of foam filled poster board. A glass disc with known (232)Th radioactivity concentration was cast for use as a calibration source. The results from the two assay methods are compared, and a projection of sensitivity from larger electret ion chamber devices is presented.

  18. Analytical investigations of glazed Islamic pottery

    International Nuclear Information System (INIS)

    Pernicka, E.; Krejsa, P.

    1978-08-01

    42 fragments of medieval glazed pottery from seven sites in Iran, Afghanistan and India were analyzed by instrumental neutron activation analysis (INAA). In addition a secondary clay standard and some samples were analyzed by X-ray fluorescence for their main components. The results of the trace analysis formed the basis for cluster analysis using the graphtheoretical method of the minimum spanning tree. The samples were partitioned into five clusters, which were compared with the provenance of their respective members. Preliminary results indicate that pottery from the north of Afganistan can be differentiated from the southern one, while the southern ware seems to be homogeneous over a large area from Herat to Ghazni. Some of the pottery samples from Sistan have a different composition, which is due to a different production technique. The mass probably consisted of a 4 : 1 mixture of quartz and clay or a 15 : 4 : 1 mixture of quartz, clay and frit for the glaze. A similar recipe is described by Abu'l-Quasim, a medieval Persian potter. (author)

  19. Basic science of new aerogels. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-08-01

    Feasibility of making monolithic composite aerogels containing silica and natural clay minerals, synthetic clay minerals or zeolites has been demonstrated, using two different processes; up to 30 wt% of the mineral phase has been successfully added. Addition of natural and synthetic clay minerals or zeolites to silica aerosols was shown to retard densification. Composite silica aerogels showed significant surface area still present after sintering at 800 or 1000 C. For most samples, 1 wt% of the second phase is equally effective in retarding densification as 10 wt%. Composite aerogels, in general, had lower hardness values than pure silica. Hardness values were inversely proportional to aerogel pore radius.

  20. Hydrogen storage property of nanoporous carbon aerogels

    International Nuclear Information System (INIS)

    Shen Jun; Liu Nianping; Ouyang Ling; Zhou Bin; Wu Guangming; Ni Xingyuan; Zhang Zhihua

    2011-01-01

    Carbon aerogels were prepared from resorcinol and formaldehyde via sol-gel process, high temperature carbonization and atmospheric pressure drying technology with solvent replacement. By changing the resorcinol-sodium carbonate molar ratio and the mass fraction of the reactants,resorcinol and formaldehyde, the pore structure of carbon aerogels can be controlled and the palladium-doped carbon aerogels were prepared.By transmission electron microscopy (TEM), X-ray diffraction (XRD) spectra, it is confirmed that the Pd exists in the skeleton structure of carbon aerogels as a form of nano simple substance pellet. The specific surface area is successfully raised by 2 times, and palladium-doped carbon aerogels with a specific surface area of 1 273 m 2 /g have been obtained by carrying out the activation process as the post-processing to the doped carbon aerogels. The hydrogen adsorption results show that the saturated hydrogen storage mass fraction of the carbon aerogels with the specific surface area of 3 212 m 2 /g is 3% in the condition of 92 K, 3.5 MPa, and 0.84% in the condition of 303 K, 3.2 MPa. In addition, the hydrogen adsorption test of palladium-doped carbon aerogels at room temperature (303 K) shows that the total hydrogen storage capacity of doped carbon aerogels is declined due to the relative small specific surface, but the hydrogen storage of unit specific surface area is enhanced. (authors)

  1. The monolithic carbon aerogels and aerogel composites for electronics and thermal protection applications

    Science.gov (United States)

    Lu, Sheng; Guo, Hui; Zhou, Yugui; Liu, Yuanyuan; Jin, Zhaoguo; Liu, Bin; Zhao, Yingmin

    2017-09-01

    Monolithic carbon aerogels have been prepared by condensation polymerization and high temperature pyrolysis. The morphology of carbon aerogels are characterized by SEM. The pore structure is characterized by N2 adsorption-desorption technique. Monolithic carbon aerogels are mesoporous nanomaterials. Carbon fiber reinforced carbon aerogel composites are prepared by in-situ sol-gel process. Fiber reinforced carbon aerogel composites are of high mechanical strength. The thermal response of the fiber reinforced aerogel composite samples are tested in an arc plasma wind tunnel. Carbon aerogel composites show good thermal insulation capability and high temperature resistance in inert atmosphere even at ultrahigh temperature up to 1800 °C. The results show that they are suitable for applications in electrodes for supercapacitors/ Lithium-ion batteries and aerospace thermal protection area.

  2. Indoor guided evacuation: TIN for graph generation and crowd evacuation

    Directory of Open Access Journals (Sweden)

    Mengchao Xu

    2016-05-01

    Full Text Available This paper presents two complementary methods: an approach to compute a network data-set for indoor space of a building by using its two-dimensional (2D floor plans and limited semantic information, combined with an optimal crowd evacuation method. The approach includes three steps: (1 generate critical points in the space, (2 connect neighbour points to build up the network, and then (3 run the optimal algorithm for optimal crowd evacuation from a room to the exit gates of the building. Triangulated Irregular Network (TIN is used in the first two steps. The optimal evacuation crowd is not based on the nearest evacuation gate for a person but relies on optimal sorting of the waiting lists at each gate of the room to be evacuated. As an example case, a rectangular room with 52 persons with two gates is evacuated in 102 elementary interval times (one interval corresponds to the time for one step for normal velocity walking, whereas it would have been evacuated in not less than 167 elementary steps. The procedure for generating the customized network involves the use of 2D floor plans of a building and some common Geographic Information System (GIS functions. This method combined with the optimal sorting lists will be helpful for guiding crowd evacuation during any emergency.

  3. CHARACTERIZATION OF THE INTERACTION BETWEEN GLAZES AND CERAMIC BODIES

    Directory of Open Access Journals (Sweden)

    Maria Kavanova

    2017-07-01

    Full Text Available The paper presents the study of stress relations of ceramic body - glaze systems of model and real, both historical and contemporary ceramics. The systems were characterized in terms of chemical composition, linear thermal coefficients and degradation effects. The results show that calculation of stress relations between ceramic body and glaze is affected predominantly by the difference in values of thermal expansion coefficients. Calculated results provide relevant information about the accordance of the glaze - ceramic body and for the characterization of surface defects.

  4. Optical And Environmental Properties Of NCAP Glazing Products

    Science.gov (United States)

    van Konynenburg, Peter; Wipfler, Richard T.; Smith, Jerry L.

    1989-07-01

    The first large area, commercially available, electrically-controllable glazing products sold under the tradename VARILITETM are based on a new liquid crystal film technology called NCAP. The glazing products can be switched in milliseconds between a highly translucent state (for privacy and glare control) to a transparent state (for high visibility) with the application of an AC voltage. The optical and environmental properties are demonstrated to meet the general requirements for architectural glazing use. The first qualified indoor product is described in detail.

  5. A new liquid-phase-separation glaze containing neodymium oxide

    International Nuclear Information System (INIS)

    Jing, S.; Xianque, C.; Luxing, K.; Pentecost, J.L.

    1986-01-01

    A color-changeable opaque glaze containing neodymium oxide was investigated. Results show that the glaze is a new example of the liquid-phase-separation type. The discrete phase droplets are from 50 to 500 nm in size. They are rich in Nd, Zn, Ca, and Mg and the continuous phase is rich in Si, Al, and K. The concentration of the discrete phase is approx. =45%. The large number of discrete droplets and the zinc oxide in the glaze increase its opacity to cover the selective light absorption and scattering of the neodymium ion and reduce the opalescence effect

  6. Electrospinning of polymer-aerogel composite fibres

    DEFF Research Database (Denmark)

    Christiansen, Lasse; Fojan, Peter

    En poster om produktion af polymer-aerogel kompositfibre ved hjælp af elektrospinning. Fiberne er produceret fra en opløsning af aerogel og polyethylene oxide i vand, som er elektrospundet gennem en enkeltnålsprocess....

  7. Development of aerogel Cherenkov detectors at Novosibirsk

    International Nuclear Information System (INIS)

    Barnyakov, A.Yu.; Barnyakov, M.Yu.; Baehr, J.; Bellunato, T.; Beloborodov, K.I.; Bobrovnikov, V.S.; Buzykaev, A.R.; Calvi, M.; Danilyuk, A.F.; Djordjadze, V.; Golubev, V.B.; Kononov, S.A.; Kravchenko, E.A.; Lipka, D.; Matteuzzi, C.; Musy, M.; Onuchin, A.P.; Perego, D.; Rodiakin, V.A.; Savinov, G.A.; Serednyakov, S.I.; Shamov, A.G.; Stephan, F.; Tayursky, V.A.; Vorobiov, A.I.

    2005-01-01

    The development of aerogel Cherenkov counters with the light collection using a wavelength shifter is described. 80 counters of this type are working in the KEDR detector. A project of similar counters for the SND detector based on 'heavy' aerogel with n=1.13 has been developed. Aerogel with a refractive index of 1.006-1.13 and dimensions of blocks up to 200x200x50mm 3 is produced by the Novosibirsk group for use in Cherenkov counters of different types. The Novosibirsk group is participating in the development of LHCb RICH as well as a beam diagnostics for a photo-injector test facility at DESY-Zeuthen. Recently we started development of RICH based on focusing aerogel (FARICH) for the endcap of the SuperBaBar. For the first time in the world the focusing aerogel with layers of different refractive indices has been produced

  8. Getting passengers out : evacuation behaviours

    NARCIS (Netherlands)

    Boer, L.C.

    2003-01-01

    When disaster strikes, mass transportation means mass evacuation. The issue is especially urgent if, despite precautions, a train comes to a stop in a tunnel and there is a fire. Adequate behaviour of passengers is a major success factor of an evacuation. Passengers should replace their original

  9. Chromogenic switchable glazing: Towards the development of the smart window

    Energy Technology Data Exchange (ETDEWEB)

    Lampert, C.M.

    1995-06-01

    The science and technology of chromogenic materials for switchable glazings in building applications is discussed. These glazings can be used for dynamic control of solar and visible energy. Currently many researchers and engineers are involved with the development of products in this field. A summary of activities in Japan, Europe, Australia, USA and Canada is made. The activities of the International Energy Agency are included. Both non-electrically activated and electrically activated glazings are discussed. Technologies covered in the first category are photochromics, and thermochromics and thermotropics. A discussion of electrically activated chromogenic glazings includes dispersed liquid crystals, dispersed particles and electrochromics. A selection of device structures and performance characteristics are compared. A discussion of transparent conductors is presented. Technical issues concerning large-area development of smart windows are discussed.

  10. Advanced evacuated tube collectors

    Science.gov (United States)

    Schertz, W. W.; Hull, J. R.; Winston, R.; Ogallagher, J.

    1985-04-01

    The essence of the design concept for these new collectors is the integration of moderate levels of nonimaging concentration inside the evacuated tube itself. This permanently protects the reflection surfaces and allows the use of highly reflecting front surface mirrors with reflectances greater than 95%. Previous fabrication and long term testing of a proof-of-concept prototype has established the technical success of the concept. Present work is directed toward the development of a manufacturable unit that will be suitable for the widest possible range of applications. Design alternatives include scaling up the original prototype's tube diameter from 5 cm to 10 cm, using an internal shaped metal concentrating reflector, using a variety of profile shapes to minimize so-called gap losses and accommodate both single ended and double-ended flow geometries, and allowing the use of heat pipes for the absorber tube.

  11. Evacuation modeling trends

    CERN Document Server

    Abreu, Orlando; Alvear, Daniel

    2016-01-01

    This book presents an overview of modeling definitions and concepts, theory on human behavior and human performance data, available tools and simulation approaches, model development, and application and validation methods. It considers the data and research efforts needed to develop and incorporate functions for the different parameters into comprehensive escape and evacuation simulations, with a number of examples illustrating different aspects and approaches. After an overview of basic modeling approaches, the book discusses benefits and challenges of current techniques. The representation of evacuees is a central issue, including human behavior and the proper implementation of representational tools. Key topics include the nature and importance of the different parameters involved in ASET and RSET and the interactions between them. A review of the current literature on verification and validation methods is provided, with a set of recommended verification tests and examples of validation tests. The book c...

  12. Aerogel Projects Ongoing in MSFC's Engineering Directorate

    Science.gov (United States)

    Shular, David A.; Smithers, Gweneth A.; Plawsky, Joel L.; Whitaker, Ann F. (Technical Monitor)

    2000-01-01

    When we speak of an aerogel material, we are referring more to process and structure am to a specific substance. Aerogel, considered the lightest solid material, has been made from silica for seventy years. Resorcinol-formaldehyde, organic aerogels have been developed more recently. However, aerogel can be made from almost any type of substance, even lead. Because an aerogel is mostly air (about 99 %), the solid substance used will affect the weight very little. The term "aerogel" connotes the sol-gel process used to manufacture the material. The aerogel begins as a liquid "sol," becomes a solid "alcogel," and is then dried to become an "aerogel." The final product has a unique structure, useful for exploitation. It is an "open pore" system with nano-sized particles and pores, has very high surface area, and is highly interconnected. Besides low weight, aerogels have ultimate (lowest) values in other properties: thermal conductivity, refractive index, sound speed, and dielectric constant. Aerogels were first prepared in 1931 by Steven Kistler, who used a supercritical drying step to replace the liquid in a gel with air, preserving the structure (1). Kistler's procedure involved a water-to-alcohol exchange step; in the 1970's, this step was eliminated when a French investigator introduced the use of tetramethylorthosilicate. Still, alcohol drying involved dangerously high temperatures and pressures. In the 1980's, the Microstructured Materials Group at Berkeley Laboratory found that the alcohol in the gel could be replaced with liquid carbon dioxide before supercritical drying, which greatly improved safety (2). 'Me most recent major contribution has been that of Deshpande, Smith and Brinker in New Mexico, who are working to eliminate the supercritical drying step (3). When aerogels were first being developed, they were evaporatively dried. However, the wet gel, when dried, underwent severe shrinkage and cracking; this product was termed "xerogel." When the

  13. Calcium in ancient glazes and glasses: a XAFS study

    Energy Technology Data Exchange (ETDEWEB)

    Veiga, J.P. [New University of Lisbon, CENIMAT, Materials Science Dept., Caparica (Portugal); Figueiredo, M.O. [New University of Lisbon, CENIMAT, Materials Science Dept., Caparica (Portugal); Crystallography and Mineralogy Centre, IICT, and INETI/IGM, Dept. Min. Resources, Alfragide (Portugal)

    2008-07-15

    Ceramic tiles used to manufacture artistic panels during the XVI to the XVIII centuries were decorated with high-lead soda-lime glazes, incorporating a diversity of chromophore cations, as ascertained by SRXRF (synchrotron radiation X-ray fluorescence). Previous X-ray absorption spectroscopy (XAS) studies have shown that sodium and lead are hosted by the glassy matrix in those glazes. However, the possible role of calcium as a modifier of the tetrahedral silica network is not fully clarified, despite being recognized that calcium cations alter some fundamental properties of glazes, namely transparency. An X-ray absorption fine structure (XAFS) study of glazes with varied colorings was therefore undertaken at Ca K- and L-edges. Well crystallized oxide minerals were used to model distinct coordination environments by oxygen atoms - close to octahedral geometry in calcite and dodecahedral in gypsum - while fluorite was chosen to mimic ideal cubic coordination. A first XAS approach suggested a minor variation in the energy separation between L{sub 2}-L{sub 3} absorption edges when comparing blue and yellow glazes, irrespective of the period of manufacture. A further study on the X-ray absorption near-edge structure (XANES) carried out at the K-edge corroborated this difference and, along with the theoretical spectra modeling performed with the FEFF code, allowed interpreting of the Ca 1s absorption spectra of glazes as arising from a non-regular high-coordination environment within the silica matrix. (orig.)

  14. Effect of Window Glazing on Colour Quality of Transmitted Daylight

    Directory of Open Access Journals (Sweden)

    Rajendra Dangol

    2017-12-01

    Full Text Available In this study, the colour quality of the daylight transmitted through different window glazing types is evaluated. The analysis considered four different types of window glazing: laminated, monolithic, coated and applied film glazing ranging in luminous transmittance from around 0.97 to <0.1. The spectral transmittance data of different window glazing types are taken from the International Glazing Data Base (IGDB, which is maintained by Lawrence Berkeley National Laboratories (LBNL. The study showed that the CIE CRI does not always seem to be the suitable method to predict the colour quality of daylight in building for particular situations. However, in the context of this study, the prediction of colour rendering properties of window glazing by other metrics such as Colour Quality Scale (version 9, Memory CRI, Ra,D65 (adjusted CRI metric with D65 as the reference illuminant performed better. For most of the daylit situations inside the building, the chromaticity difference criterion was not met. Judging the colour quality of such situations requires different method.

  15. 49 CFR 571.205(a) - Glazing equipment manufactured before September 1, 2006 and glazing materials used in vehicles...

    Science.gov (United States)

    2010-10-01

    ... injuries resulting from impact to glazing surfaces, to ensure a necessary degree of transparency in motor... material that will minimize the loss of transparency, and instructions for removing frost and ice, and, at...

  16. Aerogels from Chitosan Solutions in Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Gonzalo Santos-López

    2017-12-01

    Full Text Available Chitosan aerogels conjugates the characteristics of nanostructured porous materials, i.e., extended specific surface area and nano scale porosity, with the remarkable functional properties of chitosan. Aerogels were obtained from solutions of chitosan in ionic liquids (ILs, 1-butyl-3-methylimidazolium acetate (BMIMAc, and 1-ethyl-3-methyl-imidazolium acetate (EMIMAc, in order to observe the effect of the solvent in the structural characteristics of this type of materials. The process of elaboration of aerogels comprised the formation of physical gels through anti-solvent vapor diffusion, liquid phase exchange, and supercritical CO2 drying. The aerogels maintained the chemical identity of chitosan according to Fourier transform infrared spectrophotometer (FT-IR spectroscopy, indicating the presence of their characteristic functional groups. The internal structure of the obtained aerogels appears as porous aggregated networks in microscopy images. The obtained materials have specific surface areas over 350 m2/g and can be considered mesoporous. According to swelling experiments, the chitosan aerogels could absorb between three and six times their weight of water. However, the swelling and diffusion coefficient decreased at higher temperatures. The structural characteristics of chitosan aerogels that are obtained from ionic liquids are distinctive and could be related to solvation dynamic at the initial state.

  17. Development of aerogel Cherenkov counters at Novosibirsk

    International Nuclear Information System (INIS)

    Barnyakov, A.Yu.; Barnyakov, M.Yu.; Baehr, J.; Bellunato, T.; Beloborodov, K.I.; Bobrovnikov, V.S.; Buzykaev, A.R.; Calvi, M.; Danilyuk, A.F.; Djordjadze, V.; Golubev, V.B.; Kononov, S.A.; Kravchenko, E.A.; Lipka, D.; Matteuzzi, C.; Musy, M.; Onuchin, A.P.; Perego, D.; Rodiakin, V.A.; Savinov, G.A.; Serednyakov, S.I.; Shamov, A.G.; Stephan, F.; Tayursky, V.A.; Vorobiov, A.I.

    2006-01-01

    The work on aerogel Cherenkov counters was started in Novosibirsk in 1986. Production of aerogels with refractive indices of 1.006-1.13 and thicknesses of blocks up to 50mm was developed. The light absorption length at 400nm is 5-7m, the scattering length is 4-5cm. By these parameters, the Novosibirsk aerogel is one of the best in the world. The ASHIPH Cherenkov counters with light collection on wavelength shifters have been developed. The ASHIPH system of the KEDR detector contains 1000l of aerogel. The π/K separation is 4.5σ. A project of ASHIPH counters for the SND detector has been developed. Aerogel RICH for LHCb gives a possibility to identify hadrons in the momentum range of 2-10GeV/c. The Novosibirsk group is developing an aerogel RICH for the endcap for the SuperBaBar project. Calculations performed by a group of physicists from Novosibirsk and DESY-Zeuthen have shown that aerogel radiators enable to achieve time resolution up to 20fs

  18. Carbon aerogel electrodes for direct energy conversion

    Science.gov (United States)

    Mayer, Steven T.; Kaschmitter, James L.; Pekala, Richard W.

    1997-01-01

    A direct energy conversion device, such as a fuel cell, using carbon aerogel electrodes, wherein the carbon aerogel is loaded with a noble catalyst, such as platinum or rhodium and soaked with phosphoric acid, for example. A separator is located between the electrodes, which are placed in a cylinder having plate current collectors positioned adjacent the electrodes and connected to a power supply, and a pair of gas manifolds, containing hydrogen and oxygen positioned adjacent the current collectors. Due to the high surface area and excellent electrical conductivity of carbon aerogels, the problems relative to high polarization resistance of carbon composite electrodes conventionally used in fuel cells are overcome.

  19. Determination of critical breakage conditions for double glazing in fire

    International Nuclear Information System (INIS)

    Wang, Yu; Li, Ke; Su, Yanfei; Lu, Wei; Wang, Qingsong; Sun, Jinhua; He, Linghui; Liew, K.M.

    2017-01-01

    Highlights: • Critical heat fluxes of exposed and ambient panes are 6 kW/m"2 and 25 kW/m"2. • Critical temperature difference of fire side pane is around 60 °C. • The ambient pane survives three times longer due to radiation filter and air gap. • Heat transfer in double glazing is revealed by a heat flux based theoretical model. - Abstract: Double glazing unit normally demonstrates better fire resistance than single glazing, but the knowledge on its thermal behavior and heat transfer mechanism during fire is limited. In this work, nine double glazing units were heated by a 500 × 500 mm"2 pool fire. The incident heat flux, temperature on four surfaces, breakage time and cracking behavior were obtained. The critical breakage conditions for interior and exterior panes were determined through gradually decreasing the glass-burner distance from 750 mm to 450 mm. It is established that in double glazing the pane at ambient side can withstand significantly more time than the pane exposed to fire. The critical temperature difference for interior pane is 60 °C; the critical temperature of exterior pane breakage is much higher due to no frame-covered area. In addition, the heat flux at the time of crack initiation is 6 kW/m"2 for the pane at fire side, while more than 25 kW/m"2 for ambient side pane. To reveal the heat transfer mechanism in glazing-air-glazing, theoretical and numerical investigations are also performed, which agrees well with the experimental results.

  20. Chemical Agents: Facts about Evacuation

    Science.gov (United States)

    ... What CDC is Doing Blog: Public Health Matters Chemical Agents: Facts About Evacuation Format: Select One PDF [ ... on Facebook Tweet Share Compartir Some kinds of chemical accidents or attacks, such as a train derailment ...

  1. Building Evacuation with Mobile Devices

    OpenAIRE

    Merkel, Sabrina

    2014-01-01

    The rapidly growing world population and increasingly dense settlements demand ever-larger and more complex buildings from today's engineers. In comparison to this technological progress, a building's equipment for emergency evacuation has been hardly developed further. This work presents a concept for a building evacuation system based on mobile devices. Furthermore, various algorithms for route planning with mobile devices and for indoor localization of mobile devices are addressed.

  2. Thin Films for Advanced Glazing Applications

    Directory of Open Access Journals (Sweden)

    Ann-Louise Anderson

    2016-09-01

    Full Text Available Functional thin films provide many opportunities for advanced glazing systems. This can be achieved by adding additional functionalities such as self-cleaning or power generation, or alternately by providing energy demand reduction through the management or modulation of solar heat gain or blackbody radiation using spectrally selective films or chromogenic materials. Self-cleaning materials have been generating increasing interest for the past two decades. They may be based on hydrophobic or hydrophilic systems and are often inspired by nature, for example hydrophobic systems based on mimicking the lotus leaf. These materials help to maintain the aesthetic properties of the building, help to maintain a comfortable working environment and in the case of photocatalytic materials, may provide external pollutant remediation. Power generation through window coatings is a relatively new idea and is based around the use of semi-transparent solar cells as windows. In this fashion, energy can be generated whilst also absorbing some solar heat. There is also the possibility, in the case of dye sensitized solar cells, to tune the coloration of the window that provides unheralded external aesthetic possibilities. Materials and coatings for energy demand reduction is highly desirable in an increasingly energy intensive world. We discuss new developments with low emissivity coatings as the need to replace scarce indium becomes more apparent. We go on to discuss thermochromic systems based on vanadium dioxide films. Such systems are dynamic in nature and present a more sophisticated and potentially more beneficial approach to reducing energy demand than static systems such as low emissivity and solar control coatings. The ability to be able to tune some of the material parameters in order to optimize the film performance for a given climate provides exciting opportunities for future technologies. In this article, we review recent progress and challenges in

  3. Fibrous-Ceramic/Aerogel Composite Insulating Tiles

    Science.gov (United States)

    White, Susan M.; Rasky, Daniel J.

    2004-01-01

    Fibrous-ceramic/aerogel composite tiles have been invented to afford combinations of thermal-insulation and mechanical properties superior to those attainable by making tiles of fibrous ceramics alone or aerogels alone. These lightweight tiles can be tailored to a variety of applications that range from insulating cryogenic tanks to protecting spacecraft against re-entry heating. The advantages and disadvantages of fibrous ceramics and aerogels can be summarized as follows: Tiles made of ceramic fibers are known for mechanical strength, toughness, and machinability. Fibrous ceramic tiles are highly effective as thermal insulators in a vacuum. However, undesirably, the porosity of these materials makes them permeable by gases, so that in the presence of air or other gases, convection and gas-phase conduction contribute to the effective thermal conductivity of the tiles. Other disadvantages of the porosity and permeability of fibrous ceramic tiles arise because gases (e.g., water vapor or cryogenic gases) can condense in pores. This condensation contributes to weight, and in the case of cryogenic systems, the heat of condensation undesirably adds to the heat flowing to the objects that one seeks to keep cold. Moreover, there is a risk of explosion associated with vaporization of previously condensed gas upon reheating. Aerogels offer low permeability, low density, and low thermal conductivity, but are mechanically fragile. The basic idea of the present invention is to exploit the best features of fibrous ceramic tiles and aerogels. In a composite tile according to the invention, the fibrous ceramic serves as a matrix that mechanically supports the aerogel, while the aerogel serves as a low-conductivity, low-permeability filling that closes what would otherwise be the open pores of the fibrous ceramic. Because the aerogel eliminates or at least suppresses permeation by gas, gas-phase conduction, and convection, the thermal conductivity of such a composite even at

  4. A saxs study of silica aerogels

    International Nuclear Information System (INIS)

    Craievich, A.F.

    1986-01-01

    Aerogels produced by hypercritical drying of gels from hydrolysis of TMOS (Tetramethoxysilane) in various pH conditions and subjected to a densification process were studied by SAXS using LURE synchrotron facility. The evaluation of scattering data combined with BET measurements leads to a model of aerogels consisting of a light density matrix in which meso-and macro-pores are embedded. (Author) [pt

  5. Study of ageing effects in aerogel

    International Nuclear Information System (INIS)

    Bellunato, T.; Calvi, M.; Coluzza, C.; Longo, G.; Matteuzzi, C.; Musy, M.; Negri, P.; Perego, D.L.

    2004-01-01

    Ageing effects on aerogel due to irradiation and absorption of humidity have been investigated. Aerogel tiles have been exposed to γ radiation from a 60 Co source and to proton and neutron high intensity beams. The transmittance has been monitored in the wavelength range between 200 and 800 nm, determining the clarity factor C as a function of the increasing dose of irradiation. The index of refraction n was also measured

  6. Study of ageing effects in aerogel

    CERN Document Server

    Bellunato, T F; Coluzza, C; Longo, G; Matteuzzi, C; Musy, M; Negri, P; Perego, D L

    2004-01-01

    Ageing effects on aerogel due to irradiation and absorption of humidity have been investigated. Aerogel tiles have been exposed to gamma radiation from a 60-Co source and to proton and neutron high intensity beams. The transmittance has been monitored in the wavelength range between 200 nm and 800 nm, determining the clarity factor C as a function of the increasing dose of irradiation. The index of refraction n was also measured.

  7. Aerogels Materials as Space Debris Collectors

    Directory of Open Access Journals (Sweden)

    Thierry Woignier

    2013-01-01

    Full Text Available Material degradation due to the specific space environment becomes a key parameter for space missions. The use of large surface of brittle materials on satellites can produce, if impacted by hypervelocity particles, ejected volumes of mater 100 times higher than the impacting one. The presented work is devoted to the use of silica aerogels as passive detectors. Aerogels have been exposed to the low earth orbit of the ISS for 18 months. The study describes the aerogels process and the choice of synthesis parameters in such a way to get expected features in terms of porosity, mechanical properties, internal stresses, and transparency. Low-density aerogels (0.09 g·cm−3 have been prepared. The control of transparency necessary to see and identify particles and fragments collected is obtained using a base catalysis during gel synthesis. After return to earth, the aerogels samples have been observed using optical microscopy to detect and quantify craters on the exposed surface. First results obtained on a small part of the aerogels indicate a large number of debris collected in the materials.

  8. Influence of Aerogel Morphology and Reinforcement Architecture on Gas Convection in Aerogel Composites

    Science.gov (United States)

    Hurwitz, Frances I.; Meyer, Matthew; Guo, Haiquan; Rogers, Richard B.; DeMange, Jeffrey J.; Richardson, Hayley

    2016-01-01

    A variety of thermal protection applications require lightweight insulation capable of withstanding temperatures well above 900 C. Aerogels offer extremely low-density thermal insulation due to their mesoporous structure, which inhibits both gas convection and solid conduction. Silica aerogel systems are limited to use temperatures of 600-700 C, above which they sinter. Alumina aerogels maintain a porous structure to higher temperatures than silica, before transforming to -alumina and densifying. We have synthesized aluminosilicate aerogels capable of maintaining higher surface areas at temperatures above 1100 C than an all-alumina aerogel using -Boehmite as the aluminum source and tetraethoxysilane (TEOS) as the silicon source. The pore structure of these aerogels varies with thermal exposure temperature and time, as the aluminosilicate undergoes a variety of phase changes to form transition aluminas. Transformation to -alumina is inhibited by incorporation of silica into the alumina lattice. The aerogels are fragile, but can be reinforced using a large variety of ceramic papers, felts or fabrics. The objective of the current study is to characterize the influence of choice of reinforcement and architecture on gas permeability of the aerogel composites in both the as fabricated condition and following thermal exposure, as well as understand the effects of incorporating hydrophobic treatments in the composites.

  9. Synthesis and characterization of a nanocrystalline diamond aerogel

    Energy Technology Data Exchange (ETDEWEB)

    Pauzauskie, Peter J.; Crowhurst, Jonathan C.; Worsley, Marcus A.; Laurence, Ted A.; Kilcoyne, A. L. David; Wang, Yinmin; Willey, Trevor M.; Visbeck, Kenneth S.; Fakra, Sirine C.; Evans, William J.; Zaug, Joseph M.; Satcher, Jr., Joe H.

    2011-07-06

    Aerogel materials have myriad scientific and technological applications due to their large intrinsic surface areas and ultralow densities. However, creating a nanodiamond aerogel matrix has remained an outstanding and intriguing challenge. Here we report the high-pressure, high-temperature synthesis of a diamond aerogel from an amorphous carbon aerogel precursor using a laser-heated diamond anvil cell. Neon is used as a chemically inert, near-hydrostatic pressure medium that prevents collapse of the aerogel under pressure by conformally filling the aerogel's void volume. Electron and X-ray spectromicroscopy confirm the aerogel morphology and composition of the nanodiamond matrix. Time-resolved photoluminescence measurements of recovered material reveal the formation of both nitrogen- and silicon- vacancy point-defects, suggesting a broad range of applications for this nanocrystalline diamond aerogel.

  10. Durable polymer-aerogel based superhydrophobic coatings, a composite material

    Science.gov (United States)

    Kissel, David J; Brinker, Charles Jeffrey

    2014-03-04

    Provided are polymer-aerogel composite coatings, devices and articles including polymer-aerogel composite coatings, and methods for preparing the polymer-aerogel composite. The exemplary article can include a surface, wherein the surface includes at least one region and a polymer-aerogel composite coating disposed over the at least one region, wherein the polymer-aerogel composite coating has a water contact angle of at least about 140.degree. and a contact angle hysteresis of less than about 1.degree.. The polymer-aerogel composite coating can include a polymer and an ultra high water content catalyzed polysilicate aerogel, the polysilicate aerogel including a three dimensional network of silica particles having surface functional groups derivatized with a silylating agent and a plurality of pores.

  11. Durable polymer-aerogel based superhydrophobic coatings: a composite material

    Science.gov (United States)

    Kissel, David J.; Brinker, Charles Jeffrey

    2016-02-02

    Provided are polymer-aerogel composite coatings, devices and articles including polymer-aerogel composite coatings, and methods for preparing the polymer-aerogel composite. The exemplary article can include a surface, wherein the surface includes at least one region and a polymer-aerogel composite coating disposed over the at least one region, wherein the polymer-aerogel composite coating has a water contact angle of at least about 140.degree. and a contact angle hysteresis of less than about 1.degree.. The polymer-aerogel composite coating can include a polymer and an ultra high water content catalyzed polysilicate aerogel, the polysilicate aerogel including a three dimensional network of silica particles having surface functional groups derivatized with a silylating agent and a plurality of pores.

  12. Study on the energy performance of glazing surfaces

    Directory of Open Access Journals (Sweden)

    Ligia MOGA

    2014-12-01

    Full Text Available A proper thermal design of the building envelope represents an important factor for the energy economics. Glazing surfaces represent one of the important elements in the hygrothermal design activity of a building envelope. The window’s thermal performance has also a strong influence on the thermal performance of the opaque area of the wall. This fact imposed the research of the real interaction, of cooperation and of mutual influences of the characteristics between the two components of the wall of the building envelope, respectively the opaque and the glazing area. Optimal constructive details for the opaque and glazing area of the wall need to be properly designed in order to achieve the required thermal and energy performances imposed for new types of buildings, e.g. passive houses, zero energy buildings.

  13. Glass-ceramics frits for high mechanical resistance glazes

    International Nuclear Information System (INIS)

    Gajek, M.; Lis, J.; Partyka, J.; Wojczyk, M.

    2004-01-01

    The obtaining and application of glass-ceramics frits for glazes were discussed by many authors. This glazes are characterized by raised mechanical parameters and chemical resistance. Factors, that determines crystallization process are initial composition, heat treatment and nucleation agents. The kind of crystalline phases, crystal habit and the content of residual glass phase play the decisive role in the strengthening of the glaze. In this paper are shown results of investigation over controlled crystallization in the ternary systems; Li 2 O-Al 2 O 3 -SiO 2 , CaO-Al 2 O 3 -SiO 2 , ZnO-Al 2 O 3 -SiO 2 , MgO-Al 2 O 3 -SiO 2 , with or without nucleation agents. (author)

  14. Solar distillation between a simple and double-glazing

    Directory of Open Access Journals (Sweden)

    Abderrahmane KHECHEKHOUCHE

    2017-12-01

    Full Text Available The south-east region of Algeria suffers from a great socio-economic problem that affects a large population. Faced with the unavailability of drinking water, solar distillation; which appears to be a suitable and inexpensive solution; was adopted by local researchers. Improving the productivity of a solar greenhouse distiller is the subject of several researches in the world. As it is well known, distiller with simple glazing is wildly studied but unfortunately has feeble efficiency. Double glazing is a method that increases the efficiency of a flat solar collector. The idea is to use the same technique on a single-slope solar distiller (50 x 50 cm. Two glass plates separated by 1 cm between them air is trapped. Experience shows that this technique has a negative effect on the productivity of the distiller with a rate of 88.63%; it means 9 times. So double glazing is not recommended in the single slope solar distiller.

  15. Design and evaluation of daylighting applications of holographic glazings

    Energy Technology Data Exchange (ETDEWEB)

    Papamichael, K.; Ehrlich, C.; Ward, G.

    1996-12-01

    According to the contractual agreement, BTP would develop a computer model of the POC holographic structures and then simulate the performance of alternative designs using the RADIANCE lighting and rendering computer program [Ward 1990]. The RADIANCE model would then be used to evaluate the daylight performance of alternative designs of holographic glazings in a prototypical office space. The simulation process would be validated against actual photometric measurements of holographic glazing samples developed by POC. The results would be used to evaluate the potential for increased electric lighting savings through increased daylight illuminance levels at distances more than 15 ft--20 ft (4.6 m--6.1 m ) from the window wall.

  16. The provenance study of Chinese ancient architectonical colored glaze by INAA

    International Nuclear Information System (INIS)

    Cheng Lin; Feng Songlin; Li Rongwu; Lue Zhirong; Li Guoxia

    2008-01-01

    The colored glazes are very popular and famous in Chinese ancient architectures. In order to exactly locate the provenance of ancient architectonical colored glazes, 196 pieces of ancient colored glaze bodies and porcelain bodies fired in Xiyue Temple and Lidipo kiln are analyzed by INAA. The results of factor analysis and some archaeological questions are reported and discussed in this paper

  17. The provenance study of Chinese ancient architectonical colored glaze by INAA

    Energy Technology Data Exchange (ETDEWEB)

    Cheng Lin [Key Laboratory of Beam Technology and Material Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Radiation Center, Beijing Normal University, Beijing 100875 (China); Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)], E-mail: chenglin@bnu.edu.cn; Feng Songlin [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Li Rongwu [Department of Physics, Beijing Normal University, Beijing 100049 (China); Lue Zhirong [Shan' xi Provincial Institute of Cultural Relics and Archaeology, Xi' an 710054 (China); Li Guoxia [Institute of Physical Engineering, Zhengzhou University, Zhengzhou 450052 (China)

    2008-12-15

    The colored glazes are very popular and famous in Chinese ancient architectures. In order to exactly locate the provenance of ancient architectonical colored glazes, 196 pieces of ancient colored glaze bodies and porcelain bodies fired in Xiyue Temple and Lidipo kiln are analyzed by INAA. The results of factor analysis and some archaeological questions are reported and discussed in this paper.

  18. Bluedec in product design : Isolatiemateriaal op basis van aerogel

    NARCIS (Netherlands)

    Beurden, van K.M.M. (Karin); Goselink, E.A. (Erik)

    2014-01-01

    Aerogel is een zeer kostbaar voor de ruimtevaart ontwikkeld basismateriaal. Bluedec is een isolatiemateriaal bestaande uit een non woven kunststof dat met deze aerogel geïmpregneerd is. Hierdoor ontstaat een zeer goed isolerend materiaal dat goedkoper is dan aerogel. De

  19. City evacuations an interdisciplinary approach

    CERN Document Server

    Binner, Jane; Branicki, Layla; Galla, Tobias; Jones, Nick; King, James; Kolokitha, Magdalini; Smyrnakis, Michalis

    2015-01-01

    Evacuating a city is a complex problem that involves issues of governance, preparedness education, warning, information sharing, population dynamics, resilience and recovery. As natural and anthropogenic threats to cities grow, it is an increasingly pressing problem for policy makers and practitioners.   The book is the result of a unique interdisciplinary collaboration between researchers in the physical and social sciences to consider how an interdisciplinary approach can help plan for large scale evacuations.  It draws on perspectives from physics, mathematics, organisation theory, economics, sociology and education.  Importantly it goes beyond disciplinary boundaries and considers how interdisciplinary methods are necessary to approach a complex problem involving human actors and increasingly complex communications and transportation infrastructures.   Using real world case studies and modelling the book considers new approaches to evacuation dynamics.  It addresses questions of complexity, not only ...

  20. Dose reduction in evacuation proctography

    International Nuclear Information System (INIS)

    Hare, C.; Halligan, S.; Bartram, C.I.; Gupta, R.; Walker, A.E.; Renfrew, I.

    2001-01-01

    The goal of this study was to reduce the patient radiation dose from evacuation proctography. Ninety-eight consecutive adult patients referred for proctography to investigate difficult rectal evacuation were studied using a digital imaging system with either a standard digital program for barium examinations, a reduced dose digital program (both with and without additional copper filtration), or Video fluoroscopy. Dose-area products were recorded for each examination and the groups were compared. All four protocols produced technically acceptable examinations. The low-dose program with copper filtration (median dose 382 cGy cm 2 ) and Video fluoroscopy (median dose 705 cGy cm 2 ) were associated with significantly less dose than other groups (p < 0.0001). Patient dose during evacuation proctography can be reduced significantly without compromising the diagnostic quality of the examination. A digital program with added copper filtration conveyed the lowest dose. (orig.)

  1. Microscopic observation of laser glazed yttria-stabilized zirconia coatings

    Science.gov (United States)

    Morks, M. F.; Berndt, C. C.; Durandet, Y.; Brandt, M.; Wang, J.

    2010-08-01

    Thermal barrier coatings (TBCs) are frequently used as insulation system for hot components in gas-turbine, combustors and power plant industries. The corrosive gases which come from combustion of low grade fuels can penetrate into the TBCs and reach the metallic components and bond coat and cause hot corrosion and erosion damage. Glazing the top coat by laser beam is advanced approach to seal TBCs surface. The laser beam has the advantage of forming a dense thin layer composed of micrograins. Plasma-sprayed yttria-stabilized zirconia (YSZ) coating was glazed with Nd-YAG laser at different operating conditions. The surface morphologies, before and after laser treatment, were investigated by scanning electron microscopy. Laser beam assisted the densification of the surface by remelting a thin layer of the exposed surface. The laser glazing converted the rough surface of TBCs into smooth micron-size grains with size of 2-9 μm and narrow grain boundaries. The glazed surfaces showed higher Vickers hardness compared to as-sprayed coatings. The results revealed that the hardness increases as the grain size decreases.

  2. [Adhesion of oral microorganisms on dental porcelain polished and glazed].

    Science.gov (United States)

    Wang, Yi-ning; Wen, Guo-jiang; Shi, Bin; Pan, Xin-hua

    2003-09-01

    This study compared the roughness of porcelain polished or glazed surfaces and the adhesion of oral streptococcus mutans to them in vitro. 30 porcelain samples were made. Porcelain samples in group A were polished with diamond paste. Porcelain samples were glazed in group B and were polished with Al2O3 (240#) bur in group C. Their roughness values were measured by profilometer. Standardized cell suspensions were incubated with test samples for one hour at 37 degrees C, then retained cells were counted by image analysis (percentage area of a microscopic field covered by cells). Roughness values of group A, B, C were respectively (0.1987 +/- 0.057) microm, (0.1990 +/- 0.091) microm, (0.4260 +/- 0.174) microm. There was no significantly difference between group A and group B. The roughness samples in group C were significantly rougher than that in the other groups. The amount of retained cells in group A, group B, group C was respectively (15.92 +/- 4.37)%, (16.39 +/- 6.31)% and (41.48 +/- 12.1)%. There was no significant difference between the cell adhesion on porcelain surface glazed and polished, but more bacteria adhered on the porcelain surface in group C. Porcelain surface polished treatment was clinically acceptable compared with its glazed. They all exhibited the least amount of bacteria adhesion. The more porcelain surface was rough, the more bacteria adhered on it.

  3. Characterization of glazes, enamels and oxides by XRF

    International Nuclear Information System (INIS)

    Mbarek, Iheb

    2009-01-01

    The purpose of this work is to control the technique of X-ray fluorescence, both in qualitative and quantitative characterization for ceramic glazes, enamels and oxides. it's a recent subject of investigation, its purpose is to discover the presence of toxic substances (Pb, Cd, Sn, As ..) and their quantities if it exists in the manufacturing materials.

  4. Characterization of the interaction between glazes and ceramic bodies

    Czech Academy of Sciences Publication Activity Database

    Kavanová, M.; Kloužková, A.; Kloužek, Jaroslav

    2017-01-01

    Roč. 61, č. 3 (2017), s. 267-275 ISSN 0862-5468 Institutional support: RVO:67985891 Keywords : glazes * ceramic s * thermal analysis * coefficients of the thermal expansion * dilatometry Subject RIV: JH - Ceramic s, Fire-Resistant Materials and Glass OBOR OECD: Ceramic s Impact factor: 0.439, year: 2016

  5. Preparation and characterization of phloroglucinol-formaldehyde aerogel

    International Nuclear Information System (INIS)

    Huang Changgang; China Academy of Engineering Physics, Mianyang; Tang Yongjian; Wang Chaoyang; Yan Hongmei

    2006-01-01

    Phloroglucinol-formaldehyde (PF) aerogels and carbonized PF (CPF) aerogels were prepared from Phloroglucinol (P) and Formaldehyde (F) by sol-gel, solvent exchanging, supercritical drying and carbonization processes. The aerogel has a large specific surface area, continuous nano-network and porous structure. The density and mean porosity radius will enlarge after being carbonized, while the specific surface area will be influenced little. The micro-structure and density of aerogel are controlled by concentration of total reactants and catalyzer, respectively. Aerogels with different micro-structure and different density fit for ICF targets can be prepared by optimizing synthesis conditions. (authors)

  6. An Integrated Approach to Modeling Evacuation Behavior

    Science.gov (United States)

    2011-02-01

    A spate of recent hurricanes and other natural disasters have drawn a lot of attention to the evacuation decision of individuals. Here we focus on evacuation models that incorporate two economic phenomena that seem to be increasingly important in exp...

  7. Evacuation transportation management : task five : operational concept.

    Science.gov (United States)

    2009-06-26

    Much of what is known about evacuations is based on preparations for incidents, such as hurricanes, for which there is advance warning. With advance warning, evacuations can be planned and managed using procedures and systems that have been developed...

  8. Evacuation transportation management. Task five, Operational concept

    Science.gov (United States)

    2006-01-01

    Much of what is known about evacuations is based on preparations for incidents, such as hurricanes, for which there is advance warning. With advance warning, evacuations can be planned and managed using procedures and systems that have been developed...

  9. Evacuation Shelters - MDC_HurricaneShelter

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — A label feature class of Miami-Dade County Hurricane Evacuation Shelters (HEC) including Special Need Evacuation Centers (SNEC) and Medical Management Facilities...

  10. Evacuation of bedridden occupants: experimental research outcomes

    OpenAIRE

    Strating, N.; van Herpen, R.; Zeiler, W.

    2017-01-01

    Bedridden building occupants in hospitals and nursing homes who are not able to rescue themselves in case of a fire emergency require assistance during an evacuation. A building emergency team usually fulfils this function and will have to remove the occupants from the room. The speed at which such an evacuation is conducted however is unknown. Experiments in practice were conducted in hospitals to obtain insight in the evacuation speed and absolute evacuation times required. Furthermore, a s...

  11. Hospital evacuation; planning, assessment, performance and evaluation

    OpenAIRE

    Nero C Wabo; P Örtenwall; A Khorram-Manesh

    2012-01-01

    Objective: Malfunction in hospitals' complex internal systems, or extern threats, may result in a hospital evacuation. Factors contributing to such evacuation must be identified, analyzed and action plans should be prepared. Our aims in this study were 1) to evaluate the use of risk and vulnerability analysis as a basis for hospital evacuation plan, 2) to identify risks/hazards triggering an evacuation and evaluate the respond needed and 3) to propose a template with main key points for plann...

  12. High strength air-dried aerogels

    Science.gov (United States)

    Coronado, Paul R.; Satcher, Jr., Joe H.

    2012-11-06

    A method for the preparation of high strength air-dried organic aerogels. The method involves the sol-gel polymerization of organic gel precursors, such as resorcinol with formaldehyde (RF) in aqueous solvents with R/C ratios greater than about 1000 and R/F ratios less than about 1:2.1. Using a procedure analogous to the preparation of resorcinol-formaldehyde (RF) aerogels, this approach generates wet gels that can be air dried at ambient temperatures and pressures. The method significantly reduces the time and/or energy required to produce a dried aerogel compared to conventional methods using either supercritical solvent extraction. The air dried gel exhibits typically less than 5% shrinkage.

  13. Aerogel Cerenkov counters at DESY

    International Nuclear Information System (INIS)

    Poelz, G.

    1984-11-01

    In high energy physics it is common to identify a charged particle and its kinematical parameters by the measurement of its momentum and its velocity. Cerenkov detectors have developed into a standard tool because they operate in the γ = (1-β 2 )sup(-1/2) range from about 1 to 100 which is not easily accessible by other devices. Pions, kaons and protons in present high energy experiments reach energies of several GeV. Threshold Cerenkov detectors for these particles need indices of refraction below 1.1 which are often produced with gases under high pressure. The design for chambers operating in this region was drasticly simplified when porous materials serving as Cerenkov radiators were invented. These chambers complement the time-of-flight counters, which cover the low energy region. Aerogel of silica is up to now the only porous substance with sufficient optical transparency. Its quality has been improved substantially in recent times so that large size detectors can be constructed. (orig.)

  14. Refractive index inhomogeneity within an aerogel block

    International Nuclear Information System (INIS)

    Bellunato, T.; Calvi, M.; Da Silva Costa, C.F.; Matteuzzi, C.; Musy, M.; Perego, D.L.

    2006-01-01

    Evaluating local inhomogeneities of the refractive index inside aerogel blocks to be used as Cherenkov radiator is important for a high energy physics experiment where angular resolution is crucial. Two approaches are described and compared. The first one is based on the bending of a laser beam induced by refractive index gradients along directions normal to the unperturbed optical path. The second method exploits the Cherenkov effect itself by shooting an ultra-relativistic collimated electron beam through different points of the aerogel surface. Local refractive index variations result in sizable differences in the Cherenkov photons distribution

  15. Performance of aerogel as Cherenkov radiator

    International Nuclear Information System (INIS)

    Bellunato, T.; Calvi, M.; Matteuzzi, C.; Musy, M.; Negri, P.; Braem, A.; Chesi, E.; Hansen, C.; Liko, D.; Joram, C.; Neufeld, N.; Seguinot, J.; Weilhammer, P.; Buzykaev, A.R.; Kravchenko, E.A.; Onuchin, A.P.; Danilyuk, A.F.; Easo, S.; Wotton, S.; Jolly, S.

    2004-01-01

    Aerogel with index of refraction around 1.03 has been studied as Cherenkov radiator in a test at CERN PS using a π - and a mixed π + /p beam of momenta between 6 and 10 GeV/c. The Cherenkov photons were detected by means of four large HPD tubes designed and constructed at CERN. Results on the photoelectron yield, the Cherenkov angle and its resolution, and the π/p separation are obtained. The performances measured demonstrate that a RICH with aerogel is a viable detector for experiments with high multiplicity of particles in the final state

  16. Test of aerogel as Cherenkov radiator

    CERN Document Server

    Alemi, M; Calvi, M; Matteuzzi, C; Negri, P; Paganoni, M; Liko, D; Neufeld, N; Chesi, Enrico Guido; Joram, C; Séguinot, Jacques; Ypsilantis, Thomas

    2001-01-01

    Two different stacks of aerogel were tested in a pion/proton beam of momentum between 3 and 10 GeV/c. The optical characteristics of the aerogel samples were different: one sample was hygroscopic while the other was hydrophobic. Two HPD tubes were used as photodetectors, and different thicknesses of the stacks were used, in order to determine the photoelectron yield, the Cherenkov angle and its precision. Pion/proton separation has been demonstrated at momenta up to 10 GeV/c.

  17. Tsunami evacuation buildings and evacuation planning in Banda Aceh, Indonesia.

    Science.gov (United States)

    Yuzal, Hendri; Kim, Karl; Pant, Pradip; Yamashita, Eric

    Indonesia, a country of more than 17,000 islands, is exposed to many hazards. A magnitude 9.1 earthquake struck off the coast of Sumatra, Indonesia, on December 26, 2004. It triggered a series of tsunami waves that spread across the Indian Ocean causing damage in 11 countries. Banda Aceh, the capital city of Aceh Province, was among the most damaged. More than 31,000 people were killed. At the time, there were no early warning systems nor evacuation buildings that could provide safe refuge for residents. Since then, four tsunami evacuation buildings (TEBs) have been constructed in the Meuraxa subdistrict of Banda Aceh. Based on analysis of evacuation routes and travel times, the capacity of existing TEBs is examined. Existing TEBs would not be able to shelter all of the at-risk population. In this study, additional buildings and locations for TEBs are proposed and residents are assigned to the closest TEBs. While TEBs may be part of a larger system of tsunami mitigation efforts, other strategies and approaches need to be considered. In addition to TEBs, robust detection, warning and alert systems, land use planning, training, exercises, and other preparedness strategies are essential to tsunami risk reduction.

  18. An emerging platform for drug delivery: aerogel based systems.

    Science.gov (United States)

    Ulker, Zeynep; Erkey, Can

    2014-03-10

    Over the past few decades, advances in "aerogel science" have provoked an increasing interest for these materials in pharmaceutical sciences for drug delivery applications. Because of their high surface areas, high porosities and open pore structures which can be tuned and controlled by manipulation of synthesis conditions, nanostructured aerogels represent a promising class of materials for delivery of various drugs as well as enzymes and proteins. Along with biocompatible inorganic aerogels and biodegradable organic aerogels, more complex systems such as surface functionalized aerogels, composite aerogels and layered aerogels have also been under development and possess huge potential. Emphasis is given to the details of the aerogel synthesis and drug loading methods as well as the influence of synthesis parameters and loading methods on the adsorption and release of the drugs. Owing to their ability to increase the bioavailability of low solubility drugs, to improve both their stability and their release kinetics, there are an increasing number of research articles concerning aerogels in different drug delivery applications. This review presents an up to date overview of the advances in all kinds of aerogel based drug delivery systems which are currently under investigation. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Pedestrian and Evacuation Dynamics 2005

    CERN Document Server

    Gattermann, Peter; Knoflacher, Hermann; Schreckenberg, Michael

    2007-01-01

    Due to an increasing number of reported catastrophes all over the world, the safety especially of pedestrians today, is a dramatically growing field of interest, both for practitioners as well as scientists from various disciplines. The questions arising mainly address the dynamics of evacuating people and possible optimisations of the process by changing the architecture and /or the procedure. This concerns not only the case of ships, stadiums or buildings, all with restricted geometries, but also the evacuation of complete geographical regions due to natural disasters. Furthermore, also ‘simple’ crowd motion in ‘relaxed’ situations poses new questions with respect to higher comfort and efficiency since the number of involved persons at large events is as high as never before. In addition, as a new research topic in this field, collective animal behaviour is attracting increasing attention. All this was in the scope of the conference held in Vienna, September 28–30, 2005, the third one in a series ...

  20. Aerogel as Cherenkov radiator for RICH detectors

    International Nuclear Information System (INIS)

    Bellunato, T.; Braem, A.; Buzykaev, A.R.; Calvi, M.; Chesi, E.; Danilyuk, A.F.; Easo, S.; Hansen, C.; Jolly, S.; Joram, C.; Kravchenko, E.A.; Liko, D.; Matteuzzi, C.; Musy, M.; Negri, P.; Neufeld, N.; Onuchin, A.P.; Seguinot, J.; Weilhammer, P.; Wotton, S.

    2003-01-01

    We present here the results obtained using silica aerogel as Cherenkov radiator for the separation and identification of particles in the momentum range from 6 to 10 GeV/c. Photoelectron yield and Cherenkov ring resolution were studied under different experimental conditions and compared to the simulation

  1. Fireplace insert and its parameters depend on the used glazing

    Science.gov (United States)

    Papučík, Štefan; Čaja, Alexander

    2016-06-01

    The contribution deals with the analysis of the impact of using double glass to change the performance and emission parameters of the fireplace insert. Conventional fireplace inserts are equipped with heat-resistant glass, which is resistant to high temperatures. For this type of inserts are required to be radiant constituent maximized. Prevailing part of heat is into the interior gets just by radiation through the glazed part. The hot water fireplace inserts is the requirement that the radiant constituent to the environment to a minimum. Therefore, instead of a single glass using double glazing which is intended to reduce this part of heat transfer. The temperature in the furnace is increased, and transmitted most of the heat into the water.

  2. Evacuation exercise at the Kindergarten

    CERN Multimedia

    2001-01-01

    Every year fire evacuation exercises are organized through out CERN and our facility's Kindergarten is no exception. Just a few weeks ago, a fire simulation was carried out in the Kindergarten kitchen facility using synthetic smoke. The purpose of the exercise was to teach staff to react in a disciplined and professional manner when in the presence of danger. The simulation is always carried out at a random time so as to ensure that people in the area under the test are not aware of the exercise. For the Kindergarten the exercise was held early in the school year so as to train those who are new to the establishment. The evacuation was a complete success and all went as it was supposed to. When the children and teachers smelt smoke they followed the prescribed evacuation routes and left the building immediately. Once outside the situation was revealed as an exercise and everyone went back to business as usual, everyone that is, except the fire brigade and fire inspector.  The fire brigade checked t...

  3. Fourier analysis of conductive heat transfer for glazed roofing materials

    Energy Technology Data Exchange (ETDEWEB)

    Roslan, Nurhana Lyana; Bahaman, Nurfaradila; Almanan, Raja Noorliyana Raja; Ismail, Razidah [Faculty of Computer and Mathematical Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); Zakaria, Nor Zaini [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia)

    2014-07-10

    For low-rise buildings, roof is the most exposed surface to solar radiation. The main mode of heat transfer from outdoor via the roof is conduction. The rate of heat transfer and the thermal impact is dependent on the thermophysical properties of roofing materials. Thus, it is important to analyze the heat distribution for the various types of roofing materials. The objectives of this paper are to obtain the Fourier series for the conductive heat transfer for two types of glazed roofing materials, namely polycarbonate and polyfilled, and also to determine the relationship between the ambient temperature and the conductive heat transfer for these materials. Ambient and surface temperature data were collected from an empirical field investigation in the campus of Universiti Teknologi MARA Shah Alam. The roofing materials were installed on free-standing structures in natural ventilation. Since the temperature data are generally periodic, Fourier series and numerical harmonic analysis are applied. Based on the 24-point harmonic analysis, the eleventh order harmonics is found to generate an adequate Fourier series expansion for both glazed roofing materials. In addition, there exists a linear relationship between the ambient temperature and the conductive heat transfer for both glazed roofing materials. Based on the gradient of the graphs, lower heat transfer is indicated through polyfilled. Thus polyfilled would have a lower thermal impact compared to polycarbonate.

  4. Novel bioactive materials: silica aerogel and hybrid silica aerogel/pseudowollastonite

    Directory of Open Access Journals (Sweden)

    Reséndiz-Hernández, P. J.

    2014-10-01

    Full Text Available Silica aerogel and hybrid silica aerogel/pseudowollastonite materials were synthesized by controlled hydrolysis of tetraethoxysilane (TEOS using also methanol (MeOH and pseudowollastonite particles. The gels obtained were dried using a novel process based on an ambient pressure drying. Hexane and hexamethyl-disilazane (HMDZ were the solvents used to chemically modify the surface. In order to assess bioactivity, aerogels, without and with pseudowollastonite particles, were immersed in simulated body fluid (SBF for 7 and 14 days. The hybrid silica aerogel/pseudowollastonite showed a higher bioactivity than that observed for the single silica aerogel. However, as in both cases a lower bioactivity was observed, a biomimetic method was also used to improve it. In this particular method, samples of both materials were immersed in SBF for 7 days followed by their immersion in a more concentrated solution (1.5 SBF for 14 days. A thick and homogeneous bonelike apatite layer was formed on the biomimetically treated materials. Thus, bioactivity was successfully improved even on the aerogel with no pseudowollastonite particles. As expected, the hybrid silica aerogel/pseudowollastonite particles showed a higher bioactivity.Se sintetizaron aerogel de sílice y aerogel híbrido de sílice/partículas de pseudowollastonita por hidrólisis controlada de tetraetoxisilano (TEOS usando metanol (MeOH y partículas de pseudowollastonita. Los geles obtenidos se secaron utilizando un novedoso proceso basado en una presión de secado ambiental. Hexano y hexametil-disilazano fueron los solventes usados para modificar químicamente la superficie. Para evaluar la bioactividad, los aerogeles con y sin partículas de pseudowollastonita se sumergieron en un fluido fisiológico simulado (SBF por 7 y 14 días. El aerogel híbrido de sílice/partículas de pseudowollastonita mostró más alta bioactividad que la observada por el aerogel solo. Sin embargo, en ambos casos, se

  5. Impact of polishing on the light scattering at aerogel surface

    International Nuclear Information System (INIS)

    Barnyakov, A.Yu.; Barnyakov, M.Yu.; Bobrovnikov, V.S.; Buzykaev, A.R.; Danilyuk, A.F.; Katcin, A.A.; Kononov, S.A.; Kirilenko, P.S.; Kravchenko, E.A.; Kuyanov, I.A.; Onuchin, A.P.; Ovtin, I.V.; Predein, A.Yu.; Protsenko, R.S.

    2016-01-01

    Particle identification power of modern aerogel RICH detectors strongly depends on optical quality of radiators. It was shown that wavelength dependence of aerogel tile transparency after polishing cannot be described by the standard Hunt formula. The Hunt formula has been modified to describe scattering in a thin layer of silica dust on the surface of aerogel tile. Several procedures of polishing of aerogel tile have been tested. The best result has been achieved while using natural silk tissue. The resulting block has optical smooth surfaces. The measured decrease of aerogel transparency due to surface scattering is about few percent. This result could be used for production of radiators for the Focusing Aerogel RICH detectors.

  6. Flexible aerogel composite for mechanical stability and process of fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Coronado, P.R.; Poco, J.F.

    1999-10-26

    A flexible aerogel and process of fabrication are disclosed. An aerogel solution is mixed with fibers in a mold and allowed to gel. The gel is then processed by supercritical extraction, or by air drying, to produce a flexible aerogel formed to the shape of the mold. The flexible aerogel has excellent thermal and acoustic properties, and can be utilized in numerous applications, such as for energy absorption, insulation (temperature and acoustic), to meet the contours of aircraft shapes, and where space is limited since an inch of aerogel is a 4--5 times better insulator than an inch of fiberglass. The flexible aerogel may be of an inorganic (silica) type or an organic (carbon) type, but containing fibers, such as glass or carbon fibers.

  7. Flexible aerogel composite for mechanical stability and process of fabrication

    Science.gov (United States)

    Coronado, Paul R.; Poco, John F.

    1999-01-01

    A flexible aerogel and process of fabrication. An aerogel solution is mixed with fibers in a mold and allowed to gel. The gel is then processed by supercritical extraction, or by air drying, to produce a flexible aerogel formed to the shape of the mold. The flexible aerogel has excellent thermal and acoustic properties, and can be utilized in numerous applications, such as for energy absorption, insulation (temperature and acoustic), to meet the contours of aircraft shapes, and where space is limited since an inch of aerogel is a 4-5 times better insulator than an inch of fiberglass. The flexible aerogel may be of an inorganic (silica) type or an organic (carbon) type, but containing fibers, such as glass or carbon fibers.

  8. Flexible aerogel composite for mechanical stability and process of fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Coronado, P.R.; Poco, J.F.

    2000-07-11

    A flexible aerogel and process of fabrication are disclosed. An aerogel solution is mixed with fibers in a mold and allowed to gel. The gel is then processed by supercritical extraction, or by air drying, to produce a flexible aerogel formed to the shape of the mold. The flexible aerogel has excellent thermal and acoustic properties, and can be utilized in numerous applications, such as for energy absorption, insulation (temperature and acoustic), to meet the contours of aircraft shapes, and where space is limited since an inch of aerogel is a 4--5 times better insulator than an inch of fiberglass. The flexible aerogel may be of an inorganic (silica) type or an organic (carbon) type, but containing fibers, such as glass or carbon fibers.

  9. Comparative Study of Single-glazed and Double-glazed Windows in Terms of Energy Efficiency and Economic Expenses

    Directory of Open Access Journals (Sweden)

    Samaneh Forughian

    2017-06-01

    Full Text Available Saving fossil fuels and the use of clean sources of energy lead to reduce in building operating costs, protect the environment and people's health. Windows are the most vulnerable part of building where energy loss occurs. Double-glazed windows are very effective in keeping inside temperature isolated from outside; thereby, saving electrical and thermal energy. The current study estimates the numerical changes in cooling and heating load in case of replacement double-glazed window with single-glazed window and calculates saving level for this replacement. In this context, this paper presents a model of real samples taken in Mashhad climate. To ensure the accuracy of the simulation results, real results were compared with electricity and gas bills. To calculate energy related parameters such as cooling load, heating load, the consumption of gas and electricity, the energy simulation software (Design Builder was used. The research method was a quantitative analysis based on energy consumption modeling, associated with building windows which comes in four sections. The field study was also used to compare with real electricity and gas bills. As the first stage, samples of the plan were identified, based on the observation of climate models and library studies. Then, simulation parameters such as window materials and internal and external walls were considered. The simulation was performed based software’s parameters and model limitations were determined based on thermal, lighting, climatic and architectural parameters. Finally, the experimental and practical data were used to determine the validity of the model under Mashhad climate conditions. Overall, the results indicated that double-glazed windows could save 50% of entire building loads, 0.2% on power consumption, 16.2% on gas and 12.4% on overall households’ energy consumption.

  10. Bluedec in product design: Isolatiemateriaal op basis van aerogel

    OpenAIRE

    Beurden, van, K.M.M. (Karin); Goselink, E.A. (Erik)

    2014-01-01

    Aerogel is een zeer kostbaar voor de ruimtevaart ontwikkeld basismateriaal. Bluedec is een isolatiemateriaal bestaande uit een non woven kunststof dat met deze aerogel geïmpregneerd is. Hierdoor ontstaat een zeer goed isolerend materiaal dat goedkoper is dan aerogel. De warmtegeleidingscoëfficiënt van Bluedec in de basisuitvoering is 0,0135 W/m*K . Dat is lager dan conventionele isolatiematerialen, zie ook pagina 4. Voordeel hiervan is dat vergelijkbare of betere warmte-isolati...

  11. Synthesis of aerogel tiles with high light scattering length

    CERN Document Server

    Danilyuk, A F; Okunev, A G; Onuchin, A P; Shaurman, S A

    1999-01-01

    The possibility of aerogel tiles production for RICH detectors is described. Monolithic blocks of silica aerogel were synthesized by two-step sol-gel processing of tetraethoxysilane Si(OEt) sub 4 followed by high temperature supercritical drying with organic solvent. The important characteristic of aerogel is the light scattering length. In the wide range of refraction indexes the light scattering length exceeds 4 cm at 400 nm.

  12. Mechanically Strong Lightweight Materials for Aerospace Applications (x-aerogels)

    Science.gov (United States)

    Leventis, Nicholas

    2005-01-01

    The X-Aerogel is a new NASA-developed strong lightweight material made by reacting the mesoporous surfaces of 3-D networks of inorganic nanoparticles with polymeric crosslinkers. Since the relative amount of the crosslinker and the backbone are comparable, X-Aerogels can be viewed either as aerogels modified by templated accumulation of polymer on the skeletal nanoparticles, or as nanoporous polymers made by templated casting of polymeric precursors on a nanostructured framework. The most striking feature of X-Aerogels is that for a nominal 3-fold increase in density (still a ultralightweight material), the mechanical strength can be up to 300 times higher than the strength of the underlying native aerogel. Thus, X-Aerogels combine a multiple of the specific compressive strength of steel, with the thermal conductivity of styrofoam. XAerogels have been demonstrated with several polymers such as polyurethanes/polyureas, epoxies and polyolefins, while crosslinking of approximately 35 different oxide aerogels yields a wide variety of dimensionally stable, porous lightweight materials with interesting structural, magnetic and optical properties. X-Aerogels are evaluated for cryogenic rocket fuel storage tanks and for Advanced EVA suits, where they will play the dual role of the thermal insulator/structural material. Along the same lines, major impact is also expected by the use of X-Aerogels in structural components/thermal protection for small satellites, spacecrafts, planetary vehicles and habitats.

  13. Nitrogen-doped carbon aerogels for electrical energy storage

    Science.gov (United States)

    Campbell, Patrick; Montalvo, Elizabeth; Baumann, Theodore F.; Biener, Juergen; Merrill, Matthew; Reed, Eric W.; Worsley, Marcus A.

    2017-10-03

    Disclosed here is a method for making a nitrogen-doped carbon aerogel, comprising: preparing a reaction mixture comprising formaldehyde, at least one nitrogen-containing resorcinol analog, at least one catalyst, and at least one solvent; curing the reaction mixture to produce a wet gel; drying the wet gel to produce a dry gel; and thermally annealing the dry gel to produce the nitrogen-doped carbon aerogel. Also disclosed is a nitrogen-doped carbon aerogel obtained according to the method and a supercapacitor comprising the nitrogen-doped carbon aerogel.

  14. Thermal performance of a room with a double glazing window using glazing available in Mexican market

    International Nuclear Information System (INIS)

    Aguilar, J.O.; Xamán, J.; Olazo-Gómez, Y.; Hernández-López, I.; Becerra, G.; Jaramillo, O.A.

    2017-01-01

    Highlights: • Thermal evaluation of a Room coupled with different types of Double Glazing Window (DGW) is analyzed. • Four cases were simulated: Case 1: DGW (clear); Case 2: DGW (absorbent), Case 3: DGW (Low-e) and Case 4: DGW (reflective). • Case 4 presents the better energy saving of all cases analyzed, ∼73% lower than Case 1. • Cases 2 and 3 have a similar thermal behavior, almost 34% less than Case 1. • The global balance costs indicate that Case 4 is the better option for energy saving in warm climate. • Case 4 allows us to save up to $20.29 USD per kW h in a year in comparison to Case 1. - Abstract: A thermal evaluation of a four configurations of double glass window (DGW) coupling to a room is presented. The DGW consists of two vertical semitransparent walls separated by a 12 mm air gap. The effect of varying the ambient temperature and the incident solar radiation in the warm climate conditions in México is analyzed. Numerical simulations were conducted for four configurations; Case 1: clear glass + air gap + clear glass (Reference); Case 2: clear glass + air gap + absorbent glass; Case 3: clear glass + air gap + Low-e glass; and Case 4: clear glass + air gap + reflective glass. Optical transmittance and specular reflectance were measured individually and in one sample piece for each case. The results showed that Case 4 reduces the heat flux to the indoors by up to 73%, with respect to Case 1. Moreover, Cases 2 and 3 had a similar behavior, obtaining a reduction of indoor heat flow close to 33.5% with respect to Case 1. Case 4 is the best option for energy savings in a warm climate, where it is possible to save up to $20.29 USD per kW h per year, in comparison to Case 1. In addition, the payback period for Case 4 is 3.7 years. Therefore, the use of reflective double pane window is highly recommended in Mexican warm climates.

  15. Evacuation decision-making: process and uncertainty

    International Nuclear Information System (INIS)

    Mileti, D.; Sorensen, J.; Bogard, W.

    1985-09-01

    The purpose was to describe the processes of evacuation decision-making, identify and document uncertainties in that process and discuss implications for federal assumption of liability for precautionary evacuations at nuclear facilities under the Price-Anderson Act. Four major categories of uncertainty are identified concerning the interpretation of hazard, communication problems, perceived impacts of evacuation decisions and exogenous influences. Over 40 historical accounts are reviewed and cases of these uncertainties are documented. The major findings are that all levels of government, including federal agencies experience uncertainties in some evacuation situations. Second, private sector organizations are subject to uncertainties at a variety of decision points. Third, uncertainties documented in the historical record have provided the grounds for liability although few legal actions have ensued. Finally it is concluded that if liability for evacuations is assumed by the federal government, the concept of a ''precautionary'' evacuation is not useful in establishing criteria for that assumption. 55 refs., 1 fig., 4 tabs

  16. Routes to effective evacuation planning primer series : evacuating populations with special needs.

    Science.gov (United States)

    2009-04-01

    Evacuation operations are conducted under the authority of, and based on decisions by, local and state authorities. The purpose of this primer, Evacuating Populations with Special Needs, is to provide local and state emergency managers, government of...

  17. Alternative evacuation strategies for nuclear power accidents

    International Nuclear Information System (INIS)

    Hammond, Gregory D.; Bier, Vicki M.

    2015-01-01

    In the U.S., current protective-action strategies to safeguard the public following a nuclear power accident have remained largely unchanged since their implementation in the early 1980s. In the past thirty years, new technologies have been introduced, allowing faster computations, better modeling of predicted radiological consequences, and improved accident mapping using geographic information systems (GIS). Utilizing these new technologies, we evaluate the efficacy of alternative strategies, called adaptive protective action zones (APAZs), that use site-specific and event-specific data to dynamically determine evacuation boundaries with simple heuristics in order to better inform protective action decisions (rather than relying on pre-event regulatory bright lines). Several candidate APAZs were developed and then compared to the Nuclear Regulatory Commission’s keyhole evacuation strategy (and full evacuation of the emergency planning zone). Two of the APAZs were better on average than existing NRC strategies at reducing either the radiological exposure, the population evacuated, or both. These APAZs are especially effective for larger radioactive plumes and at high population sites; one of them is better at reducing radiation exposure, while the other is better at reducing the size of the population evacuated. - Highlights: • Developed framework to compare nuclear power accident evacuation strategies. • Evacuation strategies were compared on basis of radiological and evacuation risk. • Current strategies are adequate for smaller scale nuclear power accidents. • New strategies reduced radiation exposure and evacuation size for larger accidents

  18. Injuries in air transport emergency evacuations.

    Science.gov (United States)

    1979-02-01

    Twelve air transport evacuations are reviewed. Injuries are discussed with emphasis on configurational and procedural contributing factors. Recommendations and information about possible methods of reducing injuries are provided.

  19. Routine ultrasound guided evacuation of first trimester missed abortion versus blind evacuation

    OpenAIRE

    Mostafa Abdulla Elsayed

    2014-01-01

    Background: The clinical management of miscarriage has changed little over the years and many women undergo surgical uterine evacuation. Surgical evacuation of the uterine contents in missed abortion is a challenge to the obstetrician as it is done blindly. The current study recommends the use of ultrasound guided surgical evacuation. It serves two important advantages; the first is to complete evacuation without the need of additional step. The second is to protect against uterine perforatio...

  20. Aerogel-Based Multilayer Insulation with Micrometeoroid Protection

    Science.gov (United States)

    Begag, Redouane; White, Shannon

    2013-01-01

    Ultra-low-density, highly hydrophobic, fiber-reinforced aerogel material integrated with MLI (aluminized Mylar reflectors and B4A Dacron separators) offers a highly effective insulation package by providing unsurpassed thermal performance and significant robustness, delivering substantial MMOD protection via the addition of a novel, durable, external aerogel layer. The hydrophobic nature of the aerogel is an important property for maintaining thermal performance if the material is exposed to the environment (i.e. rain, snow, etc.) during ground installations. The hybrid aerogel/MLI/MMOD solution affords an attractive alternative because it will perform thermally in the same range as MLI at all vacuum levels (including high vacuum), and offers significant protection from micrometeoroid damage. During this effort, the required low-density and resilient aerogel materials have been developed that are needed to optimize the thermal performance for space (high vacuum) cryotank applications. The proposed insulation/MMOD package is composed of two sections: a stack of interleaved aerogel layers and MLI intended for cryotank thermal insulation, and a 1.5- to 1-in. (.2.5- to 3.8- cm) thick aerogel layer (on top of the insulation portion) for MMOD protection. Learning that low-density aerogel cannot withstand the hypervelocity impact test conditions, the innovators decided during the course of the program to fabricate a high-density and strong material based on a cross-linked aerogel (X-aerogel; developed elsewhere by the innovators) for MMOD protection. This system has shown a very high compressive strength that is capable of withstanding high-impact tests if a proper configuration of the MMOD aerogel layer is used. It was learned that by stacking two X-aerogel layers [1.5-in. (.3.8-cm) thick] separated by an air gap, the system would be able to hold the threat at a speed of 5 km/s and gpass h the test. The first aerogel panel stopped the projectile from damaging the second

  1. Preparation of silica aerogel for Cerenkov counters

    International Nuclear Information System (INIS)

    Poelz, G.; Riethmueller, R.

    1981-09-01

    Aerogel of silica was produced with an index of refraction of n = 1.024 to equip the TASSO Cerenkov detector with 1700 litres of this radiator medium. In the production process, which is described in detail, different parameters were varied to determine their influence on the shape and the optical quality of the aerogel samples. With the present equipment samples with a size of 17 x 17 x 2.3 cm 3 were manufactured at a rate of 144 pieces per week. A production efficiency of about 90% was obtained. The index of refraction for all samples around n = 1.024 is distributed with sigmasub(n) = 1.3 x 10 -3 . They have an optical transmission length of Λ = 2.64 cm at a wavelength lambda = 438 nm with sigmasub(Λ) = 0.22 cm. For samples with n = 1.017, Λ is found to be about 30% higher. (orig.) [de

  2. Bioinspired Synthesis of Monolithic and Layered Aerogels.

    Science.gov (United States)

    Han, Xiao; Hassan, Khalil T; Harvey, Alan; Kulijer, Dejan; Oila, Adrian; Hunt, Michael R C; Šiller, Lidija

    2018-04-25

    Aerogels are the least dense and most porous materials known to man, with potential applications from lightweight superinsulators to smart energy materials. To date their use has been seriously hampered by their synthesis methods, which are laborious and expensive. Taking inspiration from the life cycle of the damselfly, a novel ambient pressure-drying approach is demonstrated in which instead of employing low-surface-tension organic solvents to prevent pore collapse during drying, sodium bicarbonate solution is used to generate pore-supporting carbon dioxide in situ, significantly reducing energy, time, and cost in aerogel production. The generic applicability of this readily scalable new approach is demonstrated through the production of granules, monoliths, and layered solids with a number of precursor materials. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Particle identification system based on dense aerogel

    Energy Technology Data Exchange (ETDEWEB)

    Barnyakov, A.Yu. [Budker Institute of Nuclear Physics, 11, akademika Lavrentieva prospect, Novosibirsk 630090 (Russian Federation); Barnyakov, M.Yu. [Budker Institute of Nuclear Physics, 11, akademika Lavrentieva prospect, Novosibirsk 630090 (Russian Federation); Novosibirsk State Technical University, 20, Karl Marx prospect, Novosibirsk, 630092 (Russian Federation); Beloborodov, K.I., E-mail: K.I.Beloborodov@inp.nsk.su [Budker Institute of Nuclear Physics, 11, akademika Lavrentieva prospect, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, 2, Pirogova Street, Novosibirsk 630090 (Russian Federation); Bobrovnikov, V.S.; Buzykaev, A.R. [Budker Institute of Nuclear Physics, 11, akademika Lavrentieva prospect, Novosibirsk 630090 (Russian Federation); Danilyuk, A.F. [Boreskov Institute of Catalysis, 5, akademika Lavrentieva prospect, Novosibirsk 630090 (Russian Federation); Golubev, V.B. [Budker Institute of Nuclear Physics, 11, akademika Lavrentieva prospect, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, 2, Pirogova Street, Novosibirsk 630090 (Russian Federation); Gulevich, V.V. [Budker Institute of Nuclear Physics, 11, akademika Lavrentieva prospect, Novosibirsk 630090 (Russian Federation); Kononov, S.A.; Kravchenko, E.A. [Budker Institute of Nuclear Physics, 11, akademika Lavrentieva prospect, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, 2, Pirogova Street, Novosibirsk 630090 (Russian Federation); Onuchin, A.P.; Martin, K.A. [Budker Institute of Nuclear Physics, 11, akademika Lavrentieva prospect, Novosibirsk 630090 (Russian Federation); Novosibirsk State Technical University, 20, Karl Marx prospect, Novosibirsk, 630092 (Russian Federation); Serednyakov, S.I. [Budker Institute of Nuclear Physics, 11, akademika Lavrentieva prospect, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, 2, Pirogova Street, Novosibirsk 630090 (Russian Federation); and others

    2013-12-21

    A threshold Cherenkov counter based on dense aerogel with refraction index n=1.13 is described. This counter is used for kaon identification at momenta below 1 GeV/c in the SND detector, which takes data at the VEPP-2000 e{sup +}e{sup −} collider. The results of measurements of the counter efficiency using electrons, muons, pions, and kaons produced in e{sup +}e{sup −} annihilation are presented.

  4. Orthodontic bracket bonding to glazed full-contour zirconia

    Directory of Open Access Journals (Sweden)

    Ji-Young Kwak

    2016-05-01

    Full Text Available Objectives This study evaluated the effects of different surface conditioning methods on the bond strength of orthodontic brackets to glazed full-zirconia surfaces. Materials and Methods Glazed zirconia (except for the control, Zirkonzahn Prettau disc surfaces were pre-treated: PO (control, polishing; BR, bur roughening; PP, cleaning with a prophy cup and pumice; HF, hydrofluoric acid etching; AA, air abrasion with aluminum oxide; CJ, CoJet-Sand. The surfaces were examined using profilometry, scanning electron microscopy, and electron dispersive spectroscopy. A zirconia primer (Z-Prime Plus, Z or a silane primer (Monobond-S, S was then applied to the surfaces, yielding 7 groups (PO-Z, BR-Z, PP-S, HF-S, AA-S, AA-Z, and CJ-S. Metal bracket-bonded specimens were stored in water for 24 hr at 37℃, and thermocycled for 1,000 cycles. Their bond strengths were measured using the wire loop method (n = 10. Results Except for BR, the surface pre-treatments failed to expose the zirconia substructure. A significant difference in bond strengths was found between AA-Z (4.60 ± 1.08 MPa and all other groups (13.38 ± 2.57 - 15.78 ± 2.39 MPa, p < 0.05. For AA-Z, most of the adhesive remained on the bracket. Conclusions For bracket bonding to glazed zirconia, a simple application of silane to the cleaned surface is recommended. A zirconia primer should be used only when the zirconia substructure is definitely exposed.

  5. Flexible edge seal for vacuum insulating glazing units

    Science.gov (United States)

    Bettger, Kenneth J.; Stark, David H.

    2012-12-11

    A flexible edge seal is provided for a vacuum insulating glazing unit having a first glass pane and a second glass pane spaced-apart from the first. The edge seal comprises a seal member formed of a hermetically bondable material and having a first end, a second end and a center section disposed therebetween. The first end is hermetically bondable to a first glass pane. The second end is hermetically bondable to a second glass pane. The center section comprises a plurality of convolutes.

  6. Electro-desalination of glazed tile panels - discussion of possibilities

    DEFF Research Database (Denmark)

    Dias-Ferreira, Célia; Ottosen, Lisbeth M.; Ribeiro, Alexandra B.

    2016-01-01

    . In the few experiments conducted on tiles with attached mortar, the mortar was desalinated to a higher degree than the biscuit and successful desalination of the biscuit through the mortar requires further research. In-situ pilot scale tests were performed on highly salt-contaminated walls without tiles...... by placing electrodes at the same side of the wall. Thus it may be possible to desalinate tile panels, without any physical damage of the fragile glaze, by placing electrodes on the back of the wall or by removing some tiles, placing electrodes in their spaces, and extracting the salts from there before...... the tiles are placed back again....

  7. Intelligent Glazed Facades for Fulfilment of Future Energy Regulations

    DEFF Research Database (Denmark)

    Winther, Frederik Vildbrad; Heiselberg, Per; Jensen, Rasmus Lund

    2010-01-01

    This project aims at testing technologies for control of heat transfer, irradiation, mass transport and energy storage in order to investigate the potential of a intelligent dynamic glazed facade. Furthermore a development of algorithms for control of the technologies included in the facade......, for use in the design phase, is done. The methods used are initially based on thermal building calculations. This analysis shows that a dynamic adaptive facade is the only way in which future office buildings can fulfil the energy regulations. By designing the facade according to the usage...

  8. Carbon aerogels by pyrolysis of TEMPO-oxidized cellulose

    Science.gov (United States)

    Zhang, Sizhao; Feng, Jian; Feng, Junzong; Jiang, Yonggang; Ding, Feng

    2018-05-01

    Although carbon aerogels derived from naturally occurring materials have been developed extensively, a reasonable synthetic approach using cellulose-resource remains unclear. Here, we report a strategy to prepare carbon aerogels originated from cellulose position-selectively oxidized by TEMPO-oxidized process. Contrary to non-TEMPO-oxidized cellulose-derived carbon aerogels (NCCA) with relative loose structure, TEMPO-oxidized cellulose-derived carbon aerogels (TCCA) with tight fibrillar-continuous network are monitored, suggesting the importance of TEMPO-oxidized modification towards creating the architecture of subsequently produced carbon aerogels. TCCA endows a higher BET area despite owning slightly dense bulk density comparing with that of NCCA. The structural texture of TCCA could be maintained in a way in comparison to TEMPO-oxidized cellulose-derived aerogel, due to the integration and aggregation effect by losing the electric double layer repulsion via ionization of the surface carboxyl groups. FTIR and XPS analyses signify the evidence of non-functionalized carbon-skeleton network formation in terms of TCCA. Further, the mechanism concerning the creation of carbon aerogels is also established. These findings not only provide new insights into the production of carbon aerogels but also open up a new opportunity in the field of functional carbon materials.

  9. Aerogel and xerogel composites for use as carbon anodes

    Science.gov (United States)

    Cooper, John F [Oakland, CA; Tillotson, Thomas M [Tracy, CA; Hrubesh, Lawrence W [Pleasanton, CA

    2008-08-12

    Disclosed herein are aerogel and xerogel composite materials suitable for use as anodes in fuel cells and batteries. Precursors to the aerogel and xerogel compounds are infused with inorganic polymeric materials or carbon particles and then gelled. The gels are then pyrolyzed to form composites with internal structural support.

  10. The RICH with Aerogel for the LHCb Experiment

    CERN Document Server

    Bellunato, T; Matteuzzi, C; Musy, M; Negri, P; Perego, D L

    2006-01-01

    We report on the status of the art of the aerogel project for LHCb, from the production, in terms of specifications and achieved quality, to the optical and beam tests performed to qualify the material as a Cherenkov radiator. A brief summary of the ageing and radiation tolerance tests performed on some aerogel tiles is also given.

  11. The RICH with Aerogel for the LHCb Experiment

    International Nuclear Information System (INIS)

    Bellunato, T.; Calvi, M.; Matteuzzi, C.; Musy, M.; Negri, P.; Perego, D.L.

    2006-01-01

    We report on the status of the art of the aerogel project for LHCb, from the production, in terms of specifications and achieved quality, to the optical and beam tests performed to qualify the material as a Cherenkov radiator. A brief summary of the ageing and radiation tolerance tests performed on some aerogel tiles is also given

  12. Highly porous ceramic oxide aerogels having improved flexibility

    Science.gov (United States)

    Meador, Mary Ann B. (Inventor); Nguyen, Baochau N. (Inventor); Guo, Haiquan (Inventor)

    2012-01-01

    Ceramic oxide aerogels having improved flexibility are disclosed. Preferred embodiments exhibit high modulus and other strength properties despite their improved flexibility. The gels may be polymer cross-linked via organic polymer chains to further improve strength properties, without substantially detracting from the improved flexibility. Methods of making such aerogels are also disclosed.

  13. Chemical modification of graphene aerogels for electrochemical capacitor applications.

    Science.gov (United States)

    Hong, Jin-Yong; Wie, Jeong Jae; Xu, Yu; Park, Ho Seok

    2015-12-14

    Graphene aerogel is a relatively new type of aerogel that is ideal for energy storage applications because of its large surface area, high electrical conductivity and good chemical stability. Also, three dimensional interconnected macropores offer many advantages such as low density, fast ion and mass transfer, and easy access to storage sites. Such features allow graphene aerogels to be intensively applied for electrochemical capacitor applications. Despite the growing interest in graphene aerogel-based electrochemical capacitors, however, the graphene aerogels still suffer from their low capacitive performances and high fragility. Both relatively low capacitance and brittleness of physically crosslinked graphene aerogels remain a critical challenge. Until now, a number of alternative attempts have been devoted to overcome these shortcomings. In this perspective, we summarize the recent research progress towards the development of advanced graphene aerogel-based electrochemical capacitors according to the different approaches (e.g. porosity, composition and structure controls). Then, the recently proposed chemical strategies to improve the capacitive performances and mechanical durability of graphene aerogels for practical applications are highlighted. Finally, the current challenges and perspectives in this emerging material are also discussed.

  14. Evacuation a serious game for preparation

    NARCIS (Netherlands)

    Kolen, B.; Thonus, B.; van Zuilekom, Kasper M.; de Romph, E.

    2011-01-01

    Mass evacuation is a measure to reduce possible loss of life in the case of potential disasters. Planning for mass evacuation is only useful if these plans are tested and evaluated by government and the public in reality or in simulated events. As a result, any prior experience is likely to be

  15. Cleanability evaluation of ceramic glazes with nanometer far-infrared materials using contact angle measurement.

    Science.gov (United States)

    Wang, Lijuan; Liang, Jinsheng; Di, Xingfu; Tang, Qingguo

    2014-05-01

    The cleanability of easy-to-clean ceramic glazes doped with nanometer far-infrared materials was compared with that of some high-quality household ceramic glazes from the market. The cleanability was evaluated by the contact angle measurement using a sessile drop method with a Dataphysics OCA-30 contact angle analyzer. The results showed that the difference of contact angles of water on the glazes before soiling and after cleaning could be used as a parameter for evaluating the cleanability of the glazes. The relationship between cleanability and surface properties, such as surface free energy and surface topography, was investigated. The surface free energy of the samples and their components were calculated using van Oss acid-base approach. By measuring advancing and receding contact angles, the contact angle hysteresis of the ceramic glazes due to the surface topography was investigated. It was shown that the cleanability of ceramic glazes containing nanometer far-infrared materials (NFIM) is better than that of household ceramic glazes from market, due to a higher ratio of electron-acceptor parameter to electron-donor parameter, which led to the effect of water hydration as well as better hydrophilic property and increased smoothness. The contact angle measurement not only accurately evaluates the cleanability of the ceramic glazes, but also has a contribution to the study of cleanability theory. Moreover, this method is simple, convenient and less sample-consumption.

  16. Experimental investigation of flame impingement on vertical and inclined glazing facades

    Directory of Open Access Journals (Sweden)

    Quinn Michael

    2013-11-01

    Full Text Available Breakage and fallout of glazing systems create openings in an enclosure that affect the fire growth and the development of post flashover flames emerging outside of the openings. The behaviour of glazing is the result of its thermally induced stress response to the heat fluxes from the fire in an enclosure. In recent times building façade designs have evolved and now incorporate many different shapes, orientations and materials. The conventional single and double glazing panels have been surpassed by composite type glazing systems which include glazing and transparent resins. This paper presents experimental testing of these composite glazing panels subjected to localized fires, which have the same fire load. The effect of localized fire on the materials tested as seen in the final char patterns on both glazing systems is note-worthy. The paper also includes details of comparative calculations with EN 1991-1-2. Furthermore, results of detailed material analysis testing of the intermediate transparent resin within the glazing sandwich panels are included.

  17. Gothic green glazed tile from Malbork Castle: Multi-analytical study

    Czech Academy of Sciences Publication Activity Database

    Svorová Pawełkowicz, S.; Rohanová, D.; Svora, Petr

    2017-01-01

    Roč. 5, č. 1 (2017), č. článku 27. ISSN 2050-7445 Institutional support: RVO:61388980 Keywords : Antimony-doped tin oxide (ATO) * Green glazed tile * Malbork Castle * Medieval technology * Opacifiers * Silica-lead glaze Subject RIV: CA - Inorganic Chemistry OBOR OECD: Inorganic and nuclear chemistry

  18. Portuguese tin-glazed earthenware from the 16th century: A spectroscopic characterization of pigments, glazes and pastes

    International Nuclear Information System (INIS)

    Vieira Ferreira, L.F.; Ferreira Machado, I.; Ferraria, A.M.; Casimiro, T.M.; Colomban, Ph.

    2013-01-01

    Sherds representative of the Portuguese faience production of the early-16th century from the “Mata da Machada” kiln and from an archaeological excavation on a small urban site in the city of Aveiro (from late 15th to early 16th century) were studied with the use of non-invasive spectroscopies, namely: ground state diffuse reflectance absorption (GSDR), micro-Raman, Fourier-transform infrared (FT-IR) and proton induced X-ray (PIXE). These results were compared with the ones obtained for two Spanish productions, from Valencia and Seville, both from same period (late 15th century and 16th century), since it is well know that Portugal imported significant quantities of those goods from Spain at that time. The obtained results evidence a clear similarity in the micro-Raman spectrum in the glaze and clays of Portuguese pottery produced at “Mata da Machada” and sherds found at the mediaeval house of Homem Cristo Filho (HCF) street at Aveiro. The blue pigment in the sample from the household of Aveiro is a cobalt oxide that exists in the silicate glassy matrix in small amounts, which did not allow the formation of detectable cobalt silicate microcrystals. White glaze from Mata da Machada and Aveiro evidence tin oxide micro-Raman signatures superimposed on the bending and stretching bands of SiO 2 . All these are quite different from the Spanish products under study (Seville and Valencia), pointing to an earlier production of tin glaze earthenware in Portugal than the mid 16th century, as commonly assumed.

  19. Portuguese tin-glazed earthenware from the 16th century: A spectroscopic characterization of pigments, glazes and pastes

    Energy Technology Data Exchange (ETDEWEB)

    Vieira Ferreira, L.F., E-mail: LuisFilipeVF@ist.utl.pt [CQFM – Centro de Química-Física Molecular and IN-Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, Universidade Técnica de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Ferreira Machado, I. [CQFM – Centro de Química-Física Molecular and IN-Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, Universidade Técnica de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Department of Technology and Design, School of Technology and Management, Polytechnic Institute of Portalegre, P-7300-110 Portalegre (Portugal); Ferraria, A.M. [CQFM – Centro de Química-Física Molecular and IN-Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, Universidade Técnica de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Casimiro, T.M. [Instituto de Arqueologia e Paleociências da Universidade Nova de Lisboa, Departamento de História, Avenida de Berna 26-C, 1069-061 Lisboa (Portugal); Colomban, Ph. [Laboratoire de Dynamique, Interaction et Réactivité, UMR7075 CNRS-Université Pierre et Marie-Curie, Paris 6, 4 Place Jussieu, C49 batF, 75252 Paris Cedex 05 (France)

    2013-11-15

    Sherds representative of the Portuguese faience production of the early-16th century from the “Mata da Machada” kiln and from an archaeological excavation on a small urban site in the city of Aveiro (from late 15th to early 16th century) were studied with the use of non-invasive spectroscopies, namely: ground state diffuse reflectance absorption (GSDR), micro-Raman, Fourier-transform infrared (FT-IR) and proton induced X-ray (PIXE). These results were compared with the ones obtained for two Spanish productions, from Valencia and Seville, both from same period (late 15th century and 16th century), since it is well know that Portugal imported significant quantities of those goods from Spain at that time. The obtained results evidence a clear similarity in the micro-Raman spectrum in the glaze and clays of Portuguese pottery produced at “Mata da Machada” and sherds found at the mediaeval house of Homem Cristo Filho (HCF) street at Aveiro. The blue pigment in the sample from the household of Aveiro is a cobalt oxide that exists in the silicate glassy matrix in small amounts, which did not allow the formation of detectable cobalt silicate microcrystals. White glaze from Mata da Machada and Aveiro evidence tin oxide micro-Raman signatures superimposed on the bending and stretching bands of SiO{sub 2}. All these are quite different from the Spanish products under study (Seville and Valencia), pointing to an earlier production of tin glaze earthenware in Portugal than the mid 16th century, as commonly assumed.

  20. Quantitative analysis of silica aerogel-based thermal insulation coatings

    DEFF Research Database (Denmark)

    Kiil, Søren

    2015-01-01

    containing intact hollow glass or polymer spheres showed that silica aerogel particles are more efficient in an insulation coating than hollow spheres. In a practical (non-ideal) comparison, the ranking most likely cannot be generalized. A parameter study demonstrates how the model can be used, qualitatively......A mathematical heat transfer model for a silica aerogel-based thermal insulation coating was developed. The model can estimate the thermal conductivity of a two-component (binder-aerogel) coating with potential binder intrusion into the nano-porous aerogel structure. The latter is modelled using...... a so-called core–shell structure representation. Data from several previous experimental investigations with silica aerogels in various binder matrices were used for model validation. For some relevant cases with binder intrusion, it was possible to obtain a very good agreement between simulations...

  1. Monolithic silica aerogel - material design on the nano-scale

    DEFF Research Database (Denmark)

    Jensen, Karsten Ingerslev; Schultz, Jørgen Munthe; Kristiansen, Finn Harken

    structure of aerogel could be used for gas filters in the 20 to 100 nm region. - The sound velocity within aerogel is in the range of 100 to 300 m/s, which should be one of lowest for an inorganic material. Due to the low density, low acoustic impedance of aerogel could help boost the efficiency...... of piezoelectric transducers. - Other applications could be; waste encapsulation, spacers for vacuum insulation panels, membranes, etc. Department of Civil Engineering is co-ordinator of a current EU FP5 research project1, which deals with the application of aerogel as transparent insulation materials in windows....... Due to the excellent optical and thermal properties of aerogel, it is possible to develop windows with both high insulation and high transmittance, which is impossible applying the conventional window techniques, i.e. extra layers of glass, low-e coatings and gas fillings. It can be shown...

  2. [Chemical composition and chromaticity characteristic of Jilan glaze of Ming and Qing official kilns].

    Science.gov (United States)

    Wu, Jun-ming; Zhang, Mao-lin; Li, Qi-jiang; Wu, Juan; Quan, Kui-shan; Cao, Jian-wen

    2012-08-01

    Color glazes of Ming and Qing official kilns are excellent representatives of the famous ancient Chinese porcelains. The study of official ware with Jilan glaze has been an important topic. But it made slow progress due to the rarity of samples with strict production management and using system. The recipes, chemical composition and chromaticity characteristic of the Jilan samples excavated from official kilns in the Ming and Qing dynasties were first discussed by systematical testing with the energy dispersive X-ray fluorescence (EDXRF) and color difference meter. The results showed that the porcelain stone content in Jilan bodies of official kiln in the Ming dynasty is higher than the samples of the Qing dynasty. The manganese content in Jilan glazes of the Ming dynasty is higher than that in the Qing dynasty, while the glaze ash addition and the lightness value in the glaze are opposite.

  3. PIXE analysis of Moroccan architectural glazed ceramics of 14th-18th centuries

    International Nuclear Information System (INIS)

    Zucchiatti, A.; Azzou, A.; El Amraoui, M.; Haddad, M.; Bejjit, L.; Ait Lyazidi, S.

    2009-01-01

    The PIXE analysis of glazes and ceramic bodies of a set of architectural glazed ceramics (mostly the zellige mosaics), sampled from seven Moroccan monuments from the 14th to the 18th century AD, has been performed. We have identified high lead glazes, opacified with tin-oxide, laid over a calciferous body to produce hard tiles easy to chisel as required by the zellige technique. The analysis has revealed significant differences between the monuments examined: in particular in the formulation of the base glass and in the use of stains to produce coloured glazes. We observed the peculiarity of materials used in Marrakech and we could distinguish, both in terms of glazes and ceramic bodies, the two almost contemporary Madersas dedicated to the sultan Bou Inan, one in Meknes the other in Fez. The PIXE measurements integrate a broad range of spectrometric investigations performed in the past few years. (author)

  4. Analytical analysis of solar thermal collector with glass and Fresnel lens glazing

    Science.gov (United States)

    Zulkifle, Idris; Ruslan, Mohd Hafidz Hj; Othman, Mohd Yusof Hj; Ibarahim, Zahari

    2018-04-01

    Solar thermal collector is a system that converts solar radiation to heat. The heat will raise the temperature higher than the ambient temperature. Absorber and glazing are two important components in order to increase the temperature of the collector. The thermal absorber will release heat by convection and as radiation to the surrounding. These losses will be reduced by glazing. Other than that, glazing is beneficial for protecting the collector from dust and water. This study discusses about modelling of solar thermal collector effects of different mass flow rates with different glazing for V-groove flat plate solar collectors. The glazing used was the glass and linear Fresnel lens. Concentration ratio in this modelling was 1.3 for 0.1m solar collector thickness. Results show that solar collectors with linear Fresnel lens has the highest efficiency value of 71.18% compared to solar collectors with glass which has efficiency 54.10% with same operation conditions.

  5. A preliminary study on Fe valence of porcelain glaze by XAFS

    International Nuclear Information System (INIS)

    Zhang Maolin; Wang Changsui; Jin Pujun; Wei Shiqiang; Xu Wei; Chen Dongliang; Wu Ziyu

    2008-01-01

    Ru ware was a famous celadon in Song dynasty, whose structure analysis of glaze had always been a difficulty in scientifically analysis of ancient porcelains. The X-ray absorption fine structure spectrum (XAFS) of Fe element in glaze of Ru ware excavated in Qingliang temple was obtained. Fe valence state in porcelain glaze samples was stud/ed by Principle Component Analysis (PCA) along with linear combination fitting method. The main wavelength of the samples was also obtained by color/meter. The results show that the cyan glaze samples have great Fe 2+ /Fe 3+ , while the yellow glaze samples have small Fe 2+ /Fe 3+ . The work also showed that X-ray absorption fine structure spectrum was very suitable in nondestructive analysis of ancient ceramics. (authors)

  6. Pedestrian and Evacuation Dynamics 2012

    CERN Document Server

    Kirsch, Uwe; Schreckenberg, Michael

    2014-01-01

    The 6th International Conference on Pedestrian and Evacuation Dynamics conference (PED2012) showcased research on human locomotion. This book presents the proceedings of PED2012. Humans have walked for eons; our drive to settle the globe began with a walk out of Africa. However, much remains to discover. As the world moves toward sustainability while racing to assess and accommodate climate change, research must provide insight on the physical requirements of walking, the dynamics of pedestrians on the move and more. We must understand, predict and simulate pedestrian behaviour, to avoid dangerous situations, to plan for emergencies, and not least, to make walking more attractive and enjoyable. PED2012 offered 70 presentations and keynotes and 70 poster presentations covering new and improved mathematical models, describing new insights on pedestrian behaviour in normal and emergency cases and presenting research based on sensors and advanced observation methods. These papers offer a starting point for innova...

  7. Silver-Loaded Aluminosilicate Aerogels As Iodine Sorbents

    Energy Technology Data Exchange (ETDEWEB)

    Riley, Brian J. [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Kroll, Jared O. [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Peterson, Jacob A. [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Matyáš, Josef [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Olszta, Matthew J. [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Li, Xiaohong [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Vienna, John D. [Pacific Northwest National Laboratory, Richland, Washington 99354, United States

    2017-09-14

    This paper discusses the development of aluminosilicates aerogels as scaffolds for Ag0 nanoparticles used for chemisorption of I2(g). The starting materials for these scaffolds included both Na-Al-Si-O and Al-Si-O aerogels, both synthesized from metal alkoxides. The Ag0 particles are added by soaking the aerogels in AgNO3 followed by drying and flowing under H2/Ar to reduce Ag+ → Ag0. In some cases, samples were soaked in 3-(mercaptopropyl)trimethoxysilane under supercritical CO2 to add –SH tethers to the aerogel surfaces for more effective binding of Ag+. During the Ag+-impregnation steps, for the Na-Al-Si-O aerogels, Na was replaced with Ag, and for the Al-Si-O aerogel, Si was replaced with Ag. The Ag-loading of thiolated versus non-thiolated Na-Al-Si-O aerogels was comparable at ~35 at% whereas the Ag-loading in unthiolated Al-Si-O aerogels was significantly lower at ~ 7 at% after identical treatment. Iodine loadings in both thiolated and unthiolated Ag0-functionalized Na-Al-Si-O aerogels were > 0.5 g g-1 showing almost complete utilization of the Ag through chemisorption to form AgI. Iodine loading in the thiolated Al-Si-O aerogel was 0.31 g g-1. The control of Ag uptake over solution residence time and [AgNO3] demonstrates the ability to customize the Ag-loading in the base sorbent to regulate the capacity of iodine chemisorption. Consolidation experimental results are also presented.

  8. Comfort Study of Office Buildings with Large Glazed Areas

    Directory of Open Access Journals (Sweden)

    Violeta Motuzienė

    2017-09-01

    Full Text Available In the buildings with large glazed areas the biggest problem is the space overheating during the warm season. This causes increased energy demand for cooling. The survey was carried out during the warm and cold seasons in two office buildings with large glazed areas. The methodology was prepared for evaluating indoor climate parameters using objective and subjective evaluation. The measurements have shown that there are problems with lighting in workplaces of both buildings during both the warm and cold seasons. The biggest problem is too dry air during the cold period, an acceptable temperature is also not always in the building No. 2. The survey has shown that some employees are dissatisfied with the indoor climate in the workplace, the bigger dissatisfaction is in building No. 2. Assessing according to the O. Fanger methodology was obtained that the number of PPD is in the normal range during the cold period, whereas close to the limit when the building can not be operated in the warm period.

  9. Basaltic scorias from Romania - complex building material us for concrete, glazing tiles, ceramic glazes, glass ceramics, mineral wool

    Energy Technology Data Exchange (ETDEWEB)

    Marica, S.; Cetean, V. [PROCEMA S.A., Bucharest (Romania)

    2002-07-01

    The most spectacular deposit of basaltic scoria from Romania is the Heghes Hill from Racos, locality situated in the central part of country. This deposit emerged as grains of various dimensions, as volcanic ash with specific porosity up to 30% and vacuolar basaltic rocks. All types of basaltic scorias have specific vacuolar appearance, red- brick or blackish - grey coloured, scoria textures and similar chemical composition with others basalts of the world. The physical and mechanical characteristics determined included the scorias in the Heghes Hill in the following categories : light rocks (2,98 g/ dmc), porous(11,04%), similar to expanded slag, slightly absorbing rocks (3,86%), with low compression strengths (1700 daN/cmp). Basaltic scoria from Heghes is a very good row material for the manufacture of concrete, for obtain decorative cutting tiles glazing with ceramic and basaltic glazes (up to 40%) varied the range of colours and for obtaining glass ceramic, mineral wool, crushing sand for road maintenance, heat -insulating bricks and shid -proof material. (orig.)

  10. Novel polybenzoxazine-based carbon aerogel electrode for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Katanyoota, Porawee [Petroleum and Petrochemical College and National Center of Excellence for Petroleum, Petrochemicals and Advanced Materials, Chulalongkorn University, Bangkok 10330 (Thailand); Chaisuwan, Thayanlak, E-mail: thanyalak.c@hotmail.co [Petroleum and Petrochemical College and National Center of Excellence for Petroleum, Petrochemicals and Advanced Materials, Chulalongkorn University, Bangkok 10330 (Thailand); Wongchaisuwat, Atchana [Department of Chemistry, Kasetsart University, Bangkok 10900 (Thailand); Wongkasemjit, Sujitra, E-mail: dsujitra@chula.ac.t [Petroleum and Petrochemical College and National Center of Excellence for Petroleum, Petrochemicals and Advanced Materials, Chulalongkorn University, Bangkok 10330 (Thailand)

    2010-02-25

    In this study, polybenzoxazine, a new high performance thermosetting resin, was used to prepare carbon aerogels used as an electrode for supercapacitors. Two types of polybenzoxazines, derived from two different amines, aniline and triethylenetetramine, and denoted as BA-a and BA-teta, respectively, were chosen as the reactants for the organic precursor preparation. The surface area of carbon aerogels from both BA-a and BA-teta was 391 and 368 m{sup 2}/g, respectively. The pore size of each carbon aerogel was in the range of 2-5 nm, which is a suitable pore size for use as electrodes in electrochemical applications. The electrochemical properties of the obtained carbon aerogels showed good performance for supercapacitor applications with a specific capacitance of 55.78 and 20.53 F/g for BA-teta and BA-a, respectively. At low voltage scanning, 1 and 5 mV/s, the cyclic voltammogram of the carbon aerogel derived from BA-teta gave a better rectangular shape than that of the other carbon aerogel. The impedance spectra of both carbon aerogels confirmed the results of the capacitance and the cyclic voltammogram analyses.

  11. Novel polybenzoxazine-based carbon aerogel electrode for supercapacitors

    International Nuclear Information System (INIS)

    Katanyoota, Porawee; Chaisuwan, Thayanlak; Wongchaisuwat, Atchana; Wongkasemjit, Sujitra

    2010-01-01

    In this study, polybenzoxazine, a new high performance thermosetting resin, was used to prepare carbon aerogels used as an electrode for supercapacitors. Two types of polybenzoxazines, derived from two different amines, aniline and triethylenetetramine, and denoted as BA-a and BA-teta, respectively, were chosen as the reactants for the organic precursor preparation. The surface area of carbon aerogels from both BA-a and BA-teta was 391 and 368 m 2 /g, respectively. The pore size of each carbon aerogel was in the range of 2-5 nm, which is a suitable pore size for use as electrodes in electrochemical applications. The electrochemical properties of the obtained carbon aerogels showed good performance for supercapacitor applications with a specific capacitance of 55.78 and 20.53 F/g for BA-teta and BA-a, respectively. At low voltage scanning, 1 and 5 mV/s, the cyclic voltammogram of the carbon aerogel derived from BA-teta gave a better rectangular shape than that of the other carbon aerogel. The impedance spectra of both carbon aerogels confirmed the results of the capacitance and the cyclic voltammogram analyses.

  12. MOLECULAR DESCRIPTION OF ELECTROLYTE SOLUTION IN A CARBON AEROGEL ELECTRODE

    Directory of Open Access Journals (Sweden)

    A.Kovalenko

    2003-01-01

    Full Text Available We develop a molecular theory of aqueous electrolyte solution sorbed in a nanoporous carbon aerogel electrode, based on the replica reference interaction site model (replica RISM for realistic molecular quenched-annealed systems. We also briefly review applications of carbon aerogels for supercapacitor and electrochemical separation devices, as well as theoretical and computer modelling of disordered porous materials. The replica RISM integral equation theory yields the microscopic properties of the electrochemical double layer formed at the surface of carbon aerogel nanopores, with due account of chemical specificities of both sorbed electrolyte and carbon aerogel material. The theory allows for spatial disorder of aerogel pores in the range from micro- to macroscopic size scale. We considered ambient aqueous solution of 1 M sodium chloride sorbed in two model nanoporous carbon aerogels with carbon nanoparticles either arranged into branched chains or randomly distributed. The long-range correlations of the carbon aerogel nanostructure substantially affect the properties of the electrochemical double layer formed by the solution sorbed in nanopores.

  13. Factors associated with high-rise evacuation: qualitative results from the World Trade Center Evacuation Study.

    Science.gov (United States)

    Gershon, Robyn R M; Qureshi, Kristine A; Rubin, Marcie S; Raveis, Victoria H

    2007-01-01

    Due to the fact that most high-rise structures (i.e., >75 feet high, or eight to ten stories) are constructed with extensive and redundant fire safety features, current fire safety procedures typically only involve limited evacuation during minor to moderate fire emergencies. Therefore, full-scale evacuation of high-rise buildings is highly unusual and consequently, little is known about how readily and rapidly high-rise structures can be evacuated fully. Factors that either facilitate or inhibit the evacuation process remain under-studied. This paper presents results from the qualitative phase of the World Trade Center Evacuation Study, a three-year, five-phase study designed to improve our understanding of the individual, organizational, and environmental factors that helped or hindered evacuation from the World Trade Center (WTC) Towers 1 and 2, on 11 September 2001. Qualitative data from semi-structured, in-depth interviews and focus groups involving WTC evacuees were collected and analyzed. On the individual level, factors that affected evacuation included perception of risk (formed largely by sensory cues), preparedness training, degree of familiarity with the building, physical condition, health status, and footwear. Individual behavior also was affected by group behavior and leadership. At the organizational level, evacuation was affected by worksite preparedness planning, including the training and education of building occupants, and risk communication. The environmental conditions affecting evacuation included smoke, flames, debris, general condition and degree of crowdedness on staircases, and communication infrastructure systems (e.g., public address, landline, cellular and fire warden's telephones). Various factors at the individual, organizational, and environmental levels were identified that affected evacuation. Interventions that address the barriers to evacuation may improve the full-scale evacuation of other high-rise buildings under extreme

  14. Synthesis and Characterization Carbon Nanotubes Doped Carbon Aerogels

    Science.gov (United States)

    Xu, Yuelong; Yan, Meifang; Liu, Zhenfa

    2017-12-01

    Polycondensation of phloroglucinol, resorcinol and formaldehyde with carbon nanotube (CNT) as the additives, using sodium carbonate as the catalyst, leads to the formation of CNT - doped carbon aerogels. The structure of carbon aerogels (CAs) with carbon nanotubes (CNTs) were characterized by X-ray diffraction and scanning electron microscopy. The specific surface area, pore size distribution and pore volume were measured by surface area analyzer. The results show that when the optimum doping dosage is 5%, the specific surface area of CNT - doped carbon aerogel is up to 665 m2 g-1 and exhibit plentiful mesoporous.

  15. Evacuation decision-making: process and uncertainty

    Energy Technology Data Exchange (ETDEWEB)

    Mileti, D.; Sorensen, J.; Bogard, W.

    1985-09-01

    The purpose was to describe the processes of evacuation decision-making, identify and document uncertainties in that process and discuss implications for federal assumption of liability for precautionary evacuations at nuclear facilities under the Price-Anderson Act. Four major categories of uncertainty are identified concerning the interpretation of hazard, communication problems, perceived impacts of evacuation decisions and exogenous influences. Over 40 historical accounts are reviewed and cases of these uncertainties are documented. The major findings are that all levels of government, including federal agencies experience uncertainties in some evacuation situations. Second, private sector organizations are subject to uncertainties at a variety of decision points. Third, uncertainties documented in the historical record have provided the grounds for liability although few legal actions have ensued. Finally it is concluded that if liability for evacuations is assumed by the federal government, the concept of a ''precautionary'' evacuation is not useful in establishing criteria for that assumption. 55 refs., 1 fig., 4 tabs.

  16. ARKTOS full-scale evacuation tests

    Energy Technology Data Exchange (ETDEWEB)

    Seligman, B.; Hatfield, P. [ARKTOS Developments Ltd., Surrey, BC (Canada); Bercha, F. [Bercha Group, Calgary, AB (Canada)

    2008-09-15

    The ARKTOS amphibious vehicle can be used for evacuation operations in both open water and ice conditions. It is approved as an evacuation system by various regulators, such as the United States Coast Guard, and is operational in several marine cold regions as an escape, evacuation, and rescue (EER) system. An EER research project was performed in 2006 that provided a general reliability evaluation of the ARKTOS system. However, the project did not have the benefit of detailed full-scale tests in order to validate the associated computer model in drill or non-life threatening evacuation conditions. This paper described a follow-up set of full-scale evacuation tests designed to provide more detailed information and validation data for the reliability that the computer model described in the 2006 research project. A description and photographic illustrations of the ARKTOS system were presented. The tests and subsequent analyses were described. Specifically, the paper described the observations, and presented the statistical results from the data collected, and compared observed results with predicted results of a probabilistic EER simulation computer model. Conclusions and recommendations for reliability improvements were also provided. It was concluded that under the benign conditions, the drill performance was satisfactory in all aspects, both in the evacuation activities and the rescue or de-boarding activities. 3 refs., 1 tab., 17 figs.

  17. Study of the components of evacuation times

    International Nuclear Information System (INIS)

    Mills, G.S.; Neuhauser, K.S.; Smith, J.D.

    1997-11-01

    The magnitudes of accident dose risks calculated by the RADTRAN code depend directly on the time span between an accidental release and evacuation of the affected area surrounding potential radionuclide releases. In a previous study of truck and rail transportation accidents, and other incidents requiring evacuations, a lognormal distribution of evacuation times (time span from decision to evacuate until complete) was developed, which provided a better model for this parameter than the practice of using a highly conservative value of 24 hours. However, the distribution did not account for time required for responders to arrive on the scene, to evaluate the hazards to surrounding population and to initiate an evacuation. Data from US Department of Transportation (DOT) accident statistics have been collected and their distribution functions determined. The separate distribution functions were combined into a single, comprehensive distribution which may be sampled to supply values of the RADTRAN input parameter, EVACUATION. A sample RADTRAN calculation illustrating the effect on risks of using the distribution versus the original (24 hour), conservative point-estimate are also presented

  18. Study of the components of evacuation times

    International Nuclear Information System (INIS)

    Mills, G.S.; Neuhauser, K.S.; Smith, J.D.

    1998-01-01

    The magnitudes of accident dose-risks calculated by the RADTRAN code depend directly on the time span between an accidental release and evacuation of the affected area surrounding potential radionuclide releases. In a previous study of truck and rail transportation accidents, and other incidents requiring evacuations (Mills et al., 1995) a lognormal distribution of evacuation times (time span from decision to evacuate until complete) was developed, which provided a better model for this parameter than the practice of using a highly conservative value of 24 hours. However, the distribution did not account for time required for responders to arrive on the scene, to evaluate the hazards to surrounding population and to initiate an evacuation. Data from U.S. Department of Transportation (DOT) accident statistics have been collected and their distribution functions determined. The separate distribution functions were combined into a single, comprehensive distribution which may be sampled to supply values of the RADTRAN input parameter, EVACUATION. A sample RADTRAN calculation illustrating the effect on risks of using the distribution versus the original (24 hours), conservative point-estimate are also presented. (authors)

  19. Nonlinear hydrodynamic equations for superfluid helium in aerogel

    International Nuclear Information System (INIS)

    Brusov, Peter N.; Brusov, Paul P.

    2003-01-01

    Aerogel in superfluids is studied very intensively during last decade. The importance of these systems is connected to the fact that this allows to investigate the influence of impurities on superfluidity. We have derived for the first time nonlinear hydrodynamic equations for superfluid helium in aerogel. These equations are generalization of McKenna et al. equations for nonlinear hydrodynamics case and could be used to study sound propagation phenomena in aerogel-superfluid system, in particular--to study sound conversion phenomena. We have obtained two alternative sets of equations, one of which is a generalization of a traditional set of nonlinear hydrodynamics equations for the case of an aerogel-superfluid system and, the other one represents a la Putterman equations (equation for v→ s is replaced by equation for A→=((ρ n )/(ρσ))w→, where w→=v→ n -v→ s )

  20. Hexadecane trapped in nano-pores of silica-aerogel

    International Nuclear Information System (INIS)

    Slavikova, B.; Jesenak, K.; Iskrova, M.; Majernik, V.; Sausa, O.; Kristiak, J.

    2009-01-01

    Ways of filling of the high-porous silica-aerogel with hydrocarbon C 16 H 34 and its efficient removal from the pores by physical method of the Positron Annihilation Spectroscopy were studied. As the most effective way to fill the SiO 2 aerogel appears through the implementation of a liquid phase, while the most appropriate way of removing of hexadecane is firing at an elevated temperature. Molecular system of hexadecane closed in nano-pores of silica-aerogel behaves otherwise than volume system of the same molecules. In the case of pure hexadecane phase transition was observed at 291 K, while solidification process is gradual with decrease of temperature in cetane trapped in pores of silica-aerogel. The results of the periods of life of o-Ps indicate greater turbidity in the pores of the molecular system compared to the volume sample of hexadecane.

  1. Refractive index of silica aerogel: Uniformity and dispersion law

    International Nuclear Information System (INIS)

    Bellunato, T.; Calvi, M.; Matteuzzi, C.; Musy, M.; Perego, D.L.; Storaci, B.

    2008-01-01

    Two methods for the measurement of the uniformity of the refractive index n within a single block of silica aerogel are described. One is based on the deflection of a laser beam induced by transverse index gradients. The second exploits the Cherenkov effect, measuring the emission angle of photons radiated by 500 MeV electrons traversing the aerogel. The beam can scan the full aerogel surface providing information on point to point variations of n. The measurement of the dispersion law n(λ) is also reported. An Xe lamp coupled to a diffraction grating provides the monochromatic source. The index for each λ is measured by the prism method at a corner of an aerogel sample. A Sellmeier functional form for n(λ) is assumed, and the parameters best fitting the experimental data are given

  2. Aerogel Antennas Communications Study Using Error Vector Magnitude Measurements

    Science.gov (United States)

    Miranda, Felix A.; Mueller, Carl H.; Meador, Mary Ann B.

    2014-01-01

    This presentation discusses an aerogel antennas communication study using error vector magnitude (EVM) measurements. The study was performed using 2x4 element polyimide (PI) aerogel-based phased arrays designed for operation at 5 GHz as transmit (Tx) and receive (Rx) antennas separated by a line of sight (LOS) distance of 8.5 meters. The results of the EVM measurements demonstrate that polyimide aerogel antennas work appropriately to support digital communication links with typically used modulation schemes such as QPSK and 4 DQPSK. As such, PI aerogel antennas with higher gain, larger bandwidth and lower mass than typically used microwave laminates could be suitable to enable aerospace-to- ground communication links with enough channel capacity to support voice, data and video links from CubeSats, unmanned air vehicles (UAV), and commercial aircraft.

  3. Multifunctional Aerogel Thermal Protection Systems for Hypersonic Vehicles, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The overall objective of the Phase II project is to develop lightweight reinforced aerogel materials for use as the core structural insulation material in...

  4. Aerogel Antennas Communications Study Using Error Vector Magnitude Measurements

    Science.gov (United States)

    Miranda, Felix A.; Mueller, Carl H.; Meador, Mary Ann B.

    2014-01-01

    This paper discusses an aerogel antennas communication study using error vector magnitude (EVM) measurements. The study was performed using 4x2 element polyimide (PI) aerogel-based phased arrays designed for operation at 5 GHz as transmit (Tx) and receive (Rx) antennas separated by a line of sight (LOS) distance of 8.5 meters. The results of the EVM measurements demonstrate that polyimide aerogel antennas work appropriately to support digital communication links with typically used modulation schemes such as QPSK and pi/4 DQPSK. As such, PI aerogel antennas with higher gain, larger bandwidth and lower mass than typically used microwave laminates could be suitable to enable aerospace-to-ground communication links with enough channel capacity to support voice, data and video links from cubesats, unmanned air vehicles (UAV), and commercial aircraft.

  5. Effects of Microgravity on the Formation of Aerogels

    Science.gov (United States)

    Hunt, A. J.; Ayers, M. R.; Sibille, L.; Cronise, R. J.; Noever, D. A.

    1999-01-01

    This paper describes research to investigate fundamental aspects of the effects of microgravity on the formation of the microstructure of metal oxide alcogels and aerogels. We are studying the role of gravity on pore structure and gel uniformity in collaboration with Marshall Space Flight Center (MSFC) on gelling systems under microgravity conditions. While this project was just initiated in May 1998, related research performed earlier is described along with the plans and rationale for the current microgravity investigation to provide background and describe newly developing techniques that should be useful for the current gellation studies. The role of gravity in materials processing must be investigated through the study of well-mastered systems. Sol-gel processed materials are near-perfect candidates to determine the effect of gravity on the formation and growth of random clusters from hierarchies of aggregated units. The processes of hydrolysis, condensation, aggregation and gellation in the formation of alcogels are affected by gravity and therefore provide a rich system to study under microgravity conditions. Supercritical drying of the otherwise unstable wet alcogel preserves the alcogel structure produced during sol-gel processing as aerogel. Supercritically dried aerogel provides for the study of material microstructures without interference from the effects of surface tension, evaporation, and solvent flow. Aerogels are microstructured, low density open-pore solids. They have many unusual properties including: transparency, excellent thermal resistance, high surface area, very low refractive index, a dielectric constant approaching that of air, and extremely low sound velocity. Aerogels are synthesized using sol-gel processing followed by supercritical solvent extraction that leaves the original gel structure virtually intact. These studies will elucidate the effects of microgravity on the homogeneity of the microstructure and porosity of aerogel. The

  6. Elemental oxides analysis of the medieval period glazed ware from Gogha, Gulf of Khambhat, Gujarat, India

    Digital Repository Service at National Institute of Oceanography (India)

    Gaur, A.S.; Khedekar, V.; Rao, B.R.

    for elemental oxides using scanning electron microscope and energy dispersive spectrum. The results indicate that silicon oxide content of the glazed sherds varies between approx. 73 and 77%, forming three-fourths of the total composition, while it ranges from...

  7. Infrared reflecting glazing for automotive application. New developments to improve fuel efficiency and thermal comfort

    Energy Technology Data Exchange (ETDEWEB)

    Thielsch, R.; Wahl, A.; Kleinhempel, R. [Southwall Europe GmbH, Grossroehrsdorf (Germany); Coda, M.; Boman, L. [Southwall Technologies Inc., Palo Alto, CA (United States)

    2011-04-15

    Solar control coatings in automotive glazing improve the thermal comfort for passengers, degrease solar irradiation into the cabin and reduce fading of materials. In IRR glazing solar radiation reduction is performed by silver based low-e-stacks with high visual transmittance and high near infrared reflectance. The proposed ARB regulation for Califormia published 2009 demanded for reduced total solartransmittance Tts of <50% of automotive glazing in new cars from 2012 on and of <40% starting 2016. Unfortunately, the regulation was ceased last minute and of March 2010 due to some technical concerns related to proper operation of electronic communication devices. Nevertheless, the technical goals regarding the total solar energy transmittance became a widely accepted performance target for solar heat protection glazing in upcoming new car models for the next years. In order to achieve the challenging new Tts target <40% major steps forward in coating design and optimization of layer properties are required. (orig.)

  8. The provenance study of Chinese ancient color glaze from Shanxi by INAA and factor analysis

    International Nuclear Information System (INIS)

    Cheng, L.; Ding, X.L.; Feng, S.L.; Feng, X.Q.; Lu, Z.R.

    2005-01-01

    This paper reports the results of the provenance study of Chinese ancient color glaze in Shanxi. The minor and trace elements of body of color glaze in different dynasty from Xiyue temper kiln and that of Lidipo kiln in Ming Dynasty determined by INAA, some of ancient porcelain from Lidipo kiln were measured, also. The factor analysis showed that provenances of the ancient color glazes from Xiyue Temple that were produced during Song Dynasty to the early Qing Dynasty were in the place of the Xiyue kiln, and body material of ancient color have little been changed, on the other hand, that of Later Qing Dynasty were-produced from Lidipo kiln. Different color glazes were measured by SRXRF and it proved the colored elements were Fe and Cu.

  9. Directional and hemispherical solar energy transmittance of single and double glazing

    NARCIS (Netherlands)

    Nijnatten, van P.A.; Hugot-Le Goff, le A; Granqvist, C.-G.; Lampert, C.M.

    1992-01-01

    Solar and visual light transmittance, color appearance, thermal emissivity, and other optical properties of architectural glazing are in general angular dependent. Realistic computation of solar properties, therefore, requires the angular behavior to be known. Determination of these properties for

  10. A RICH with aerogel: a study of refractive index uniformity

    CERN Document Server

    Alemi, M; Calvi, M; Matteuzzi, C; Musy, M; Perego, D L; Easo, S

    2004-01-01

    The use of aerogel as a radiator in the RICH detectors of LHCb is a challenge due to the hot environment of the hadron collider LHC. Large size tiles of silica aerogel were recently produced with unprecedented optical quality for such dimensions. Results of laboratory measurements and beam tests are briefly reported. A description of a method to measure the uniformity of the index of refraction within the tile is given.

  11. Polyimide-Foam/Aerogel Composites for Thermal Insulation

    Science.gov (United States)

    Williams, Martha; Fesmire, James; Sass, Jared; Smith, Trent; Weoser. Erol

    2009-01-01

    Composites of specific types of polymer foams and aerogel particles or blankets have been proposed to obtain thermal insulation performance superior to those of the neat polyimide foams. These composites have potential to also provide enhanced properties for vibration dampening or acoustic attenuation. The specific type of polymer foam is denoted "TEEK-H", signifying a series, denoted H, within a family of polyimide foams that were developed at NASA s Langley Research Center and are collectively denoted TEEK (an acronym of the inventors names). The specific types of aerogels include Nanogel aerogel particles from Cabot Corporation in Billerica, MA. and of Spaceloft aerogel blanket from Aspen Aerogels in Northborough, MA. The composites are inherently flame-retardant and exceptionally thermally stable. There are numerous potential uses for these composites, at temperatures from cryogenic to high temperatures, in diverse applications that include aerospace vehicles, aircraft, ocean vessels, buildings, and industrial process equipment. Some low-temperature applications, for example, include cryogenic storage and transfer or the transport of foods, medicines, and chemicals. Because of thermal cycling, aging, and weathering most polymer foams do not perform well at cryogenic temperatures and will undergo further cracking over time. The TEEK polyimides are among the few exceptions to this pattern, and the proposed composites are intended to have all the desirable properties of TEEK-H foams, plus improved thermal performance along with enhanced vibration or acoustic-attenuation performance. A composite panel as proposed would be fabricated by adding an appropriate amount of TEEK friable balloons into a mold to form a bottom layer. A piece of flexible aerogel blanket material, cut to the desired size and shape, would then be placed on the bottom TEEK layer and sandwiched between another top layer of polyimide friable balloons so that the aerogel blanket would become

  12. Optical sensing of triethylamine using CdSe aerogels

    International Nuclear Information System (INIS)

    Yao Qinghong; Brock, Stephanie L

    2010-01-01

    The photoluminescence (PL) response of highly porous CdSe aerogels to triethylamine (TEA) is investigated and compared to results from prior studies on single crystals and nanoparticle-polymer composites. As-prepared CdSe aerogels show significant and reversible enhancement of luminescence intensity upon exposure to TEA relative to the intensity in pure argon carrier gas. The enhancement in the PL response is dependent on the concentration and linear over the range of TEA concentration studied (4.7 x 10 3 -75 x 10 3 ppm). The sensing response of previously tested samples exhibits saturation behavior that is modeled using Langmuir adsorption isotherms, yielding adsorption equilibrium constants in the range 300-380 atm -1 . The response is sensitively affected by the surface characteristics of the aerogel; when the wet gels are treated with pyridine prior to aerogel formation, the response to TEA is diminished, and when as-prepared aerogels are heated in a vacuum, no subsequent response is observed. Deactivation is attributed to an increase in surface oxide (SeO 2 ) and decrease in surface Cd 2+ Lewis acid sites. Sensing runs of approximately one hour have little impact on the morphology or crystallinity of the aerogels, but do result in partial removal of residual thiolate ligands left over from the gelation process.

  13. Modeling silica aerogel optical performance by determining its radiative properties

    Science.gov (United States)

    Zhao, Lin; Yang, Sungwoo; Bhatia, Bikram; Strobach, Elise; Wang, Evelyn N.

    2016-02-01

    Silica aerogel has been known as a promising candidate for high performance transparent insulation material (TIM). Optical transparency is a crucial metric for silica aerogels in many solar related applications. Both scattering and absorption can reduce the amount of light transmitted through an aerogel slab. Due to multiple scattering, the transmittance deviates from the Beer-Lambert law (exponential attenuation). To better understand its optical performance, we decoupled and quantified the extinction contributions of absorption and scattering separately by identifying two sets of radiative properties. The radiative properties are deduced from the measured total transmittance and reflectance spectra (from 250 nm to 2500 nm) of synthesized aerogel samples by solving the inverse problem of the 1-D Radiative Transfer Equation (RTE). The obtained radiative properties are found to be independent of the sample geometry and can be considered intrinsic material properties, which originate from the aerogel's microstructure. This finding allows for these properties to be directly compared between different samples. We also demonstrate that by using the obtained radiative properties, we can model the photon transport in aerogels of arbitrary shapes, where an analytical solution is difficult to obtain.

  14. Key design features of multi-vacuum glazing for windows: A review

    Directory of Open Access Journals (Sweden)

    Ali Hassan

    2017-01-01

    Full Text Available The use of vacuum glazed windows is increasing due to their application in mod-ern building design. Among various types of vacuum glazed windows reported in literature, thermal transmittance of single glass sheet (conventional window i. e 6 W/m2k is reduced by 66 and 77% using air filled double glazed and air filled triple glazed windows, respectively. Using low emittance coatings thermal transmittance of double glazed windows is reduced by 53%, however it offsets the visibility by reduc-ing light transmittance by 5%. Stresses due to temperature/pressure gradients if not eliminated may lead to reduction in service life of vacuum glazed windows. Vacuum created between the glass sheets is used to reduce conductive heat transfer. Degrada-tion in the vacuum is caused by number of factors such as, permeation of gaseous molecules through glass sheets, leakage through sealing, thermal/optical desorption, and photo-fragmentation of organic species have been critically reviewed and future trends are outlined.

  15. Evaluation of green tea extract as a glazing material for shrimp frozen by cryogenic freezing.

    Science.gov (United States)

    Sundararajan, Srijanani; Prudente, Alfredo; Bankston, J David; King, Joan M; Wilson, Paul; Sathivel, Subramaniam

    2011-09-01

    Solutions of green tea (Camellia sinensis) extract (GTE) in distilled water were evaluated as a glazing material for shrimp frozen by cryogenic freezing. Total of 2%, 3%, and/or 5% GTE solutions (2GTE, 3GTE, 5GTE) were used for glazing. Distilled water glazed (GDW) and nonglazed shrimp (NG) served as controls. The GTE was characterized by measuring color, pH, (o) Brix, total phenols, and % antiradical activity. Individual catechins were identified by HPLC. The freezing time, freezing rate, and energy removal rate for freezing shrimp by cryogenic freezing process were estimated. The frozen shrimp samples were stored in a freezer at -21 °C for 180 d. Samples were analyzed for pH, moisture content, glazing yield, thaw yield, color, cutting force, and thiobarbituric acid reactive substances (TBARS) after 1, 30, 90, and 180 d. The HPLC analysis of GTE revealed the presence of catechins and their isomers and the total polyphenol content was 148.10 ± 2.49 g/L. The freezing time (min) and energy removal rate (J/s) were 48.67 ± 2.3 and 836.67 ± 78.95, respectively. Glazed samples had higher moisture content compared to NG shrimp after 180 d storage. GTE was effective in controlling the lipid oxidation in shrimp. Glazing with GTE affected a* and b* color values, but had no significant effect on the L* values of shrimp. © 2011 Institute of Food Technologists®

  16. Energy efficient glazed office buildings with double skin facades in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, Bo; Blomsterberg, Aake (WSP Environmental (Sweden)). e-mail: bo.eriksson@wspgroup.se

    2009-07-01

    Many modern office buildings have highly glazed facades. Their energy efficiency and indoor climate are, however, being questioned. Therefore more and more of these buildings are being built with double skin facades, which can provide improvements: A project BESTFACADE, with participants from Austria, Germany, Greece, Portugal (France) and Sweden, was therefore funded by the European Commission (IEE) to actively promote well-performing concepts of double skin facades. Included were best practice guidelines, which included the determination of the energy use and thermal comfort by simulations for warm, mild and cold climates. The main conclusion is that the choice of glazing properties such as glazing area, U-value (thermal transmittance) of the glazing and its profiles, g-value (the total solar energy transmittance) of the glazing and type of solar shading are crucial for the energy and indoor climate performance of an office. The choice of control strategies for ventilation of the cavity and operation of solar shading are crucial. The above choices are very dependant on the climate. Choices which are optimal in a cold climate, will not work very well in a warm climate, and vice versa. From an energy and indoor climate point of view a highly glazed office with a double skin facade is often preferred to a single

  17. Floor tile glass-ceramic glaze for improvement of the resistance to surface abrasion

    Energy Technology Data Exchange (ETDEWEB)

    Gajek, M; Lis, J; Partyka, J; Wojczyk, M, E-mail: mgajek@agh.edu.pl [AGH University of Science and Technology, Faculty of Materials Science and Ceramic, al. Mickiewicza 30, 30-059 Cracow (Poland)

    2011-10-29

    The results of research aimed at the study on frits and glass-ceramic glazes for floor tiles, based on compositions located in the primary field of cordierite crystallization within the system MgO-Al{sub 2}O{sub 3}-SiO{sub 2}, have been presented. The results comprise investigations on the frits crystallization abilities, stability of the crystallizing phase under conditions of single-stage a fast firing cycle (time below 60 minutes) depending on their chemical composition and the influence of the nucleation agents. The influence of the nucleating agents namely TiO{sub 2}, ZrO{sub 2}, V{sub 2}O{sub 5} on phase composition of obtained crystalline glazes, mechanical parameters and microstructure, has been examined. The strength tests proved increased mechanical resistance of crystalline glazes. Obtained glazes are characterized by high microhardness in range 6{approx}8 GPa, as well as the increased wear resistance measured by the loss of weight below 100 mg / 55 cm{sup 2} (PN-EN ISO 10545-7). Significant increase of these parameters as compared with non-crystalline glazes, where micro-hardness values range between 5{approx}6 GPa and the wear resistance values range from 120 to 200 mg, has been proved. Starting glasses (frits) and glazes of the ternary system MgO-SiO{sub 2}-Al{sub 2}O{sub 3}, were examined with use of DTA, XRD and SEM methods.

  18. Floor tile glass-ceramic glaze for improvement of the resistance to surface abrasion

    Science.gov (United States)

    Gajek, M.; Lis, J.; Partyka, J.; Wójczyk, M.

    2011-10-01

    The results of research aimed at the study on frits and glass-ceramic glazes for floor tiles, based on compositions located in the primary field of cordierite crystallization within the system MgO-Al2O3-SiO2, have been presented. The results comprise investigations on the frits crystallization abilities, stability of the crystallizing phase under conditions of single-stage a fast firing cycle (time below 60 minutes) depending on their chemical composition and the influence of the nucleation agents. The influence of the nucleating agents namely TiO2, ZrO2, V2O5 on phase composition of obtained crystalline glazes, mechanical parameters and microstructure, has been examined. The strength tests proved increased mechanical resistance of crystalline glazes. Obtained glazes are characterized by high microhardness in range 6~8 GPa, as well as the increased wear resistance measured by the loss of weight below 100 mg / 55 cm2 (PN-EN ISO 10545-7). Significant increase of these parameters as compared with non-crystalline glazes, where micro-hardness values range between 5~6 GPa and the wear resistance values range from 120 to 200 mg, has been proved. Starting glasses (frits) and glazes of the ternary system MgO-SiO2-Al2O3, were examined with use of DTA, XRD and SEM methods.

  19. Floor tile glass-ceramic glaze for improvement of the resistance to surface abrasion

    International Nuclear Information System (INIS)

    Gajek, M; Lis, J; Partyka, J; Wojczyk, M

    2011-01-01

    The results of research aimed at the study on frits and glass-ceramic glazes for floor tiles, based on compositions located in the primary field of cordierite crystallization within the system MgO-Al 2 O 3 -SiO 2 , have been presented. The results comprise investigations on the frits crystallization abilities, stability of the crystallizing phase under conditions of single-stage a fast firing cycle (time below 60 minutes) depending on their chemical composition and the influence of the nucleation agents. The influence of the nucleating agents namely TiO 2 , ZrO 2 , V 2 O 5 on phase composition of obtained crystalline glazes, mechanical parameters and microstructure, has been examined. The strength tests proved increased mechanical resistance of crystalline glazes. Obtained glazes are characterized by high microhardness in range 6∼8 GPa, as well as the increased wear resistance measured by the loss of weight below 100 mg / 55 cm 2 (PN-EN ISO 10545-7). Significant increase of these parameters as compared with non-crystalline glazes, where micro-hardness values range between 5∼6 GPa and the wear resistance values range from 120 to 200 mg, has been proved. Starting glasses (frits) and glazes of the ternary system MgO-SiO 2 -Al 2 O 3 , were examined with use of DTA, XRD and SEM methods.

  20. Hybrid aerogels and bioactive aerogels under uniaxial compression: an in situ SAXS study

    Directory of Open Access Journals (Sweden)

    Esquivias, L.

    2010-12-01

    Full Text Available The complex structure of hybrid organic/inorganic aerogels is composed by an inorganic phase covalently bonded to an organic chain forming a copolymer. Conventional hybrid aerogels were studied as well as bioactive hybrid aerogels, that is, aerogels with a calcium active phase added. In this work, the relationship between mechanical response and nanostructure was studied, using a specifically designed sample-holder for in situ uniaxial compression obtaining at the same time the small-angle X-ray pattern from synchrotron radiation (SAXS. Structural elements can be described as a particulated silica core surrounded by the organic chains. These chains are compressed on the direction parallel to the load, and a relationship between macroscopic uniaxial compression and particle and pore deformations can be established.

    La compleja estructura de los aerogeles híbridos orgánico/inorgánicos está compuesta por una fase inorgánica de sílice, unida mediante enlaces covalentes a una red de cadenas orgánicas. Se han estudiado composites híbridos convencionales y bioactivos, esto es, con una fase activa de calcio añadida. En este trabajo se ha investigado la relación entre la respuesta mecánica y la nanoestructura, con ayuda de un portamuestras específicamente diseñado para el estudio in situ de muestras bajo compresión uniaxial, a la vez que se obtiene el espectro de rayos-X a bajo-ángulo de radiación sincrotrón (SAXS. Los elementos estructurales se pueden describir como núcleos particulados de sílice rodeados de las cadenas orgánicas. Estas, se comprimen en la dirección paralela a la carga pudiéndose establecer una relación entre la compresión uniaxial macroscópica y la deformación de las partículas y poros que forman la estructura.

  1. Pedestrian evacuation modeling to reduce vehicle use for distant tsunami evacuations in Hawaiʻi

    Science.gov (United States)

    Wood, Nathan J.; Jones, Jamie; Peters, Jeff; Richards, Kevin

    2018-01-01

    Tsunami waves that arrive hours after generation elsewhere pose logistical challenges to emergency managers due to the perceived abundance of time and inclination of evacuees to use vehicles. We use coastal communities on the island of Oʻahu (Hawaiʻi, USA) to demonstrate regional evacuation modeling that can identify where successful pedestrian-based evacuations are plausible and where vehicle use could be discouraged. The island of Oʻahu has two tsunami-evacuation zones (standard and extreme), which provides the opportunity to examine if recommended travel modes vary based on zone. Geospatial path distance models are applied to estimate population exposure as a function of pedestrian travel time and speed out of evacuation zones. The use of the extreme zone triples the number of residents, employees, and facilities serving at-risk populations that would be encouraged to evacuate and slightly reduces the percentage of residents (98–76%) that could evacuate in less than 15 min at a plausible speed (with similar percentages for employees). Areas with lengthy evacuations are concentrated in the North Shore region for the standard zone but found all around the Oʻahu coastline for the extreme zone. The use of the extreme zone results in a 26% increase in the number of hotel visitors that would be encouraged to evacuate, and a 76% increase in the number of them that may require more than 15 min. Modeling can identify where pedestrian evacuations are plausible; however, there are logistical and behavioral issues that warrant attention before localized evacuation procedures may be realistic.

  2. Monolithic three-dimensional electrochemical energy storage system on aerogel or nanotube scaffold

    Science.gov (United States)

    Farmer, Joseph C; Stadermann, Michael

    2013-11-12

    A monolithic three-dimensional electrochemical energy storage system is provided on an aerogel or nanotube scaffold. An anode, separator, cathode, and cathodic current collector are deposited on the aerogel or nanotube scaffold.

  3. Evaluation of supercritical CO2 dried cellulose aerogels as nano-biomaterials

    Science.gov (United States)

    Lee, Sinah; Kang, Kyu-Young; Jeong, Myung-Joon; Potthast, Antje; Liebner, Falk

    2017-10-01

    Cellulose is the renewable, biodegradable and abundant resource and is suggested as an alternative material to silica due to the high price and environmental load of silica. The first step for cellulose aerogel production is to dissolve cellulose, and hydrated calcium thiocyanate molten salt is one of the most effective solvents for preparing porous material. Cellulose aerogels were prepared from dissolved cellulose samples of different degree of polymerization (DP) and drying methods, and tested with shrinkage, density and mechanical strength. Supercritical CO2 dried cellulose aerogels shrank less compared to freeze-dried cellulose aerogels, whereas the densities were increased according to the DP increases in both cellulose aerogels. Furthermore, scanning electron microscope (SEM) images showed that the higher DP cellulose aerogels were more uniform with micro-porous structure. Regarding the mechanical strength of cellulose aerogels, supercritical CO2 dried cellulose aerogels with higher molecular weight were much more solid.

  4. A method of emotion contagion for crowd evacuation

    Science.gov (United States)

    Cao, Mengxiao; Zhang, Guijuan; Wang, Mengsi; Lu, Dianjie; Liu, Hong

    2017-10-01

    The current evacuation model does not consider the impact of emotion and personality on crowd evacuation. Thus, there is large difference between evacuation results and the real-life behavior of the crowd. In order to generate more realistic crowd evacuation results, we present a method of emotion contagion for crowd evacuation. First, we combine OCEAN (Openness, Extroversion, Agreeableness, Neuroticism, Conscientiousness) model and SIS (Susceptible Infected Susceptible) model to construct the P-SIS (Personalized SIS) emotional contagion model. The P-SIS model shows the diversity of individuals in crowd effectively. Second, we couple the P-SIS model with the social force model to simulate emotional contagion on crowd evacuation. Finally, the photo-realistic rendering method is employed to obtain the animation of crowd evacuation. Experimental results show that our method can simulate crowd evacuation realistically and has guiding significance for crowd evacuation in the emergency circumstances.

  5. Aerogel Cherenkov Counters of the KEDR Detector

    CERN Document Server

    Ovtin, I V; Barnyakov, M Y; Bobrovnikov, V S; Buzykaev, A R; Danilyuk, A F; Katcin, A A; Kononov, S A; Kravchenko, E A; Kuyanov, I A; Onuchin, A P; Rodiakin, V A

    2017-01-01

    The particle identification system of the KEDR detector is based on aerogel threshold Cherenkov counters called ASHIPH counters. The system consists of 160 counters arranged in two layers. An event reconstruction program for the ASHIPH system was developed. The position of each counter relative to the tracking system was determined using cosmic muons and Bhabha events. The geometric efficiency of the ASHIPH system was verified with Bhabha events. The efficiency of relativistic particle detection was measured with cosmic muons. A π/K separation of 4δ in the momentum range 0.95 −1.45 GeV/c was confirmed. A simulation program for the ASHIPH counters has been developed.

  6. Reinforced plastics and aerogels by nanocrystalline cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Leung, Alfred C. W.; Lam, Edmond; Chong, Jonathan; Hrapovic, Sabahudin; Luong, John H. T., E-mail: john.luong@cnrc-nrc.gc.ca [National Research Council Canada (Canada)

    2013-05-15

    Nanocrystalline cellulose (NCC), a rigid rod-like nanoscale material, can be produced from cellulosic biomass in powder, liquid, or gel forms by acid and chemical hydrolysis. Owing to its unique and exceptional physicochemical properties, the incorporation of a small amount of NCC into plastic enhances the mechanical strength of the latter by several orders of magnitudes. Carbohydrate-based NCC poses no serious environmental concerns, providing further impetus for the development and applications of this green and renewable biomaterial to fabricate lightweight and biodegradable composites and aerogels. Surface functionalization of NCC remains the main focus of NCC research to tailor its properties for dispersion in hydrophilic or hydrophobic media. It is of uttermost importance to develop tools and protocols for imaging of NCC in a complex matrix and quantify its reinforcement effect.

  7. Neutron activation analysis of the arovenance relation of tang tri-color glazed potteryies of huangye kiln and yaozhou kiln

    International Nuclear Information System (INIS)

    Li Guoxia; Zhao Weijuan; Gao Zhengyao; Xie Jianzhong; Guo Min

    2006-01-01

    The technique of neutron activation analysis (NAA) has been employed to measure the content of 29 kinds of elements in the Tang Tri-color glazed potteryies of Huangye kiln and Yaozhou kiln. Then a fuzzy cluster analysis has been conducted to the NAA data. The results indicate that the places of origin of raw materials of body samples in the Tang Tri-color glazed potteryies of Huangye kiln are very concentrated, and that the places of origin of raw materials of body and glaze samples are scattered the places of origin of raw materials of the body and glaze raw material cover that of the body raw material. The source of raw materials of samples in the Tang Tri-color glazed potteryies of Huangye kiln is obviously different from that of samples in the Tang Tri-color glazed potteryies of Yaozhou kiln. (authors)

  8. Characteristics of ancient Egyptian glazed ceramic objects from Fatimid and Mamluk periods as revealed by ion beam analysis

    International Nuclear Information System (INIS)

    Sadek, Hamada; Abd El Hady M M

    2012-01-01

    Ion beam analysis (PIXE, μPIXE) has been successfully applied in analysis of archaeological materials, it has many advantages. In this work Ion Beam Analysis (IBA) used in analysis of ancient Egyptian glazed ceramic from 10th to the 16th centuries (Fatimid and Mamluk periods). Glazed ceramic samples from Al-Fustat Excavation store have been chosen to represent different colours (green, blue, brown, black ...etc), the colours of glaze depend on many factors such as oxides present in the glaze layer, fluxes and the conditions in which objects had been manufactured in the past. Ion Beam allows the identification of elemental composition of the glaze layer i.e., the information about colorants used in glaze, which is of great importance for compositional data play a key role in solving questions concerning dating, provenance, technology, use and the relationship between ancient cultures with the environment.

  9. The glass-like glazed coating made of cathode-ray tube faceplates cullet

    Directory of Open Access Journals (Sweden)

    N.І. Zavgorodnya

    2016-05-01

    Full Text Available The tendency of the current time is to find ways of expedient municipal solid waste recycling as a secondary raw material with similar physicochemical and mechanical characteristics for the purpose of efficient use of resources and reduction of harmful impact on the environment. Due to the termination the production of monitors and television sets with cathode-ray tubes, a significant part of them is grow out of use in the form of dimensional waste. Kinescopes of these electric devices contain valuable components including the screen and conical glass and cathode-luminophors. Existing trends in the world of CRT faceplates cullet recycling argue for reasonability of recycling ways of this valuable secondary raw materials. Aim: The aim of researches is to determine the impact of the full replacement of quartz sand by faceplates cullet and using the zinc sulfide, reconstituted of used cathode-luminophors, as a secondary raw material in the production of glass-like glaze on the basic properties of color glaze. Materials and Methods: Cathode-ray tube faceplates are cut off during removal process, washed from dirt, dried, crushed by press, milled in a cheek grinder and finally crushed in a barrel mill. The slurried impurity (clay, dyes of desired color, including ZnS, water are added to this powder. The received mix is processed of wet grinding for slip production. Slip is surfaced on glass-ceramic tile, dried up, burned at maximum temperature of 900ºС. Results: Experimental research has shown that glass-forming, modifying and intermediate oxides of inorganic substances are added to the glaze with the CRT faceplates cullet. The Chasiv Yar clay belongs to the group with significant gas emission. The water vapor arising during the clay dehydration plays role of the "carrier" of heavy non-volatile components, considerably accelerates gas processes and increases activity of gas components. Zinc sulphide, dissolved in the silicate glaze melts when heated

  10. Comparison of calculation and simulation of evacuation in real buildings

    Science.gov (United States)

    Szénay, Martin; Lopušniak, Martin

    2018-03-01

    Each building must meet requirements for safe evacuation in order to prevent casualties. Therefore methods for evaluation of evacuation are used when designing buildings. In the paper, calculation methods were tested on three real buildings. The testing used methods of evacuation time calculation pursuant to Slovak standards and evacuation time calculation using the buildingExodus simulation software. If calculation methods have been suitably selected taking into account the nature of evacuation and at the same time if correct values of parameters were entered, we will be able to obtain almost identical times of evacuation in comparison with real results obtained from simulation. The difference can range from 1% to 27%.

  11. Application of large-area chromogenics to architectural glazings

    Science.gov (United States)

    Selkowitz, Stephen E.

    1990-03-01

    Glass plays a significant role in the design of building envelopes today. Since its emergence during the last century as a major building material, glass has evolved into an ubiquitous and versatile building design element, performing functions today that would have been unimaginable a few years ago. The optical clarity and transparency of glass that we take for granted is one of its most unique features. Glass windows keep out the cold wind and rain without blocking the view, but also perform many more complex functions which require variable properties and tradeoffs between conflicting conditions. The glazing that provides view must also provide visual privacy at other times and must sometimes become totally opaque (for audiovisual shows, for example). Transparent glass admits daylight, providing good color rendition and offsetting electric lighting energy needs, but it can also create discomfort and disability glare conditions. The sun provides desirable warmth in winter but its heat is unwelcome in summer when it contributes to thermal discomfort and cooling energy requirements. And glass is an important element in the appearance and aesthetics of a building, both interior and exterior.

  12. Aerogel as a Sample Collector and Sample Mount for Transmission XRD Analysis

    Science.gov (United States)

    Bish, D. L.; Vaniman, D. T.; Chipera, S. J.; Yen, A. S.; Jones, S. M.

    2001-01-01

    Silica aerogel can be used for dust collection and in situ X-ray analysis. Aerogels can be less absorbing than Be, and it is feasible to obtain X-ray transmission factors >50% using typical aerogels together with a 100-micrometer Be backing foil. Additional information is contained in the original extended abstract.

  13. Evacuation of the NET vacuum chamber

    International Nuclear Information System (INIS)

    Muller, R.A.

    1987-01-01

    Parametric calculations of the evacuation process were carried out for the NET-vacuum chamber involving two blanket designs. The results show that with an acceptable vacuum pumping capacity the required start vacuum conditions can be realized within reasonable time. The two blanket concepts do not differ remarkably in their evacuation behaviour. The remaining large pressure differences between the different locations of the vacuum chamber can be reduced if approximately 30% of the total gas flow is extracted from the heads of the blanket replacement ports

  14. Evacuation of the NET vacuum chamber

    International Nuclear Information System (INIS)

    Mueller, R.

    1986-01-01

    Parametric calculations of the evacuation process were carried out for the NET-vacuum chamber involving two blanket designs. The results show that with an acceptable vacuum pumping capacity the required start vacuum conditions can be realized within reasonable time. The two blanket concepts do not differ remarkably in their evacuation behaviour. The remaining large pressure differences between the different locations of the vacuum chamber can be reduced if approximately 30% of the total gas flow is extracted from the heads of the blanket replacement ports. (author)

  15. Optically Transparent Thermally Insulating Silica Aerogels for Solar Thermal Insulation.

    Science.gov (United States)

    Günay, A Alperen; Kim, Hannah; Nagarajan, Naveen; Lopez, Mateusz; Kantharaj, Rajath; Alsaati, Albraa; Marconnet, Amy; Lenert, Andrej; Miljkovic, Nenad

    2018-04-18

    Rooftop solar thermal collectors have the potential to meet residential heating demands if deployed efficiently at low solar irradiance (i.e., 1 sun). The efficiency of solar thermal collectors depends on their ability to absorb incoming solar energy and minimize thermal losses. Most techniques utilize a vacuum gap between the solar absorber and the surroundings to eliminate conduction and convection losses, in combination with surface coatings to minimize reradiation losses. Here, we present an alternative approach that operates at atmospheric pressure with simple, black, absorbing surfaces. Silica based aerogels coated on black surfaces have the potential to act as simple and inexpensive solar thermal collectors because of their high transmission to solar radiation and low transmission to thermal radiation. To demonstrate their heat-trapping properties, we fabricated tetramethyl orthosilicate-based silica aerogels. A hydrophilic aerogel with a thickness of 1 cm exhibited a solar-averaged transmission of 76% and thermally averaged transmission of ≈1% (at 100 °C). To minimize unwanted solar absorption by O-H groups, we functionalized the aerogel to be hydrophobic, resulting in a solar-averaged transmission of 88%. To provide a deeper understanding of the link between aerogel properties and overall efficiency, we developed a coupled radiative-conductive heat transfer model and used it to predict solar thermal performance. Instantaneous solar thermal efficiencies approaching 55% at 1 sun and 80 °C were predicted. This study sheds light on the applicability of silica aerogels on black coatings for solar thermal collectors and offers design priorities for next-generation solar thermal aerogels.

  16. Pedestrian collective motion in competitive room evacuation.

    Science.gov (United States)

    Garcimartín, A; Pastor, J M; Martín-Gómez, C; Parisi, D; Zuriguel, I

    2017-09-07

    When a sizable number of people evacuate a room, if the door is not large enough, an accumulation of pedestrians in front of the exit may take place. This is the cause of emerging collective phenomena where the density is believed to be the key variable determining the pedestrian dynamics. Here, we show that when sustained contact among the individuals exists, density is not enough to describe the evacuation, and propose that at least another variable -such as the kinetic stress- is required. We recorded evacuation drills with different degrees of competitiveness where the individuals are allowed to moderately push each other in their way out. We obtain the density, velocity and kinetic stress fields over time, showing that competitiveness strongly affects them and evidencing patterns which have been never observed in previous (low pressure) evacuation experiments. For the highest competitiveness scenario, we detect the development of sudden collective motions. These movements are related to a notable increase of the kinetic stress and a reduction of the velocity towards the door, but do not depend on the density.

  17. Uncertainty in a spatial evacuation model

    Science.gov (United States)

    Mohd Ibrahim, Azhar; Venkat, Ibrahim; Wilde, Philippe De

    2017-08-01

    Pedestrian movements in crowd motion can be perceived in terms of agents who basically exhibit patient or impatient behavior. We model crowd motion subject to exit congestion under uncertainty conditions in a continuous space and compare the proposed model via simulations with the classical social force model. During a typical emergency evacuation scenario, agents might not be able to perceive with certainty the strategies of opponents (other agents) owing to the dynamic changes entailed by the neighborhood of opponents. In such uncertain scenarios, agents will try to update their strategy based on their own rules or their intrinsic behavior. We study risk seeking, risk averse and risk neutral behaviors of such agents via certain game theory notions. We found that risk averse agents tend to achieve faster evacuation time whenever the time delay in conflicts appears to be longer. The results of our simulations also comply with previous work and conform to the fact that evacuation time of agents becomes shorter once mutual cooperation among agents is achieved. Although the impatient strategy appears to be the rational strategy that might lead to faster evacuation times, our study scientifically shows that the more the agents are impatient, the slower is the egress time.

  18. Evacuation of bedridden occupants : experimental research outcomes

    NARCIS (Netherlands)

    Strating, N.; van Herpen, R.; Zeiler, W.

    2017-01-01

    Bedridden building occupants in hospitals and nursing homes who are not able to rescue themselves in case of a fire emergency require assistance during an evacuation. A building emergency team usually fulfils this function and will have to remove the occupants from the room. The speed at which such

  19. Evacuation Risks: a tentative approach for quantification

    International Nuclear Information System (INIS)

    Bastien, M.C.; Dumas, M.; Laporte, J; Parmentier, N.

    1985-01-01

    This study tries to assess the risk of deaths and injuries from motor vehicle accidents associated with an evacuation of population groups in case of nuclear plant accidents. The risk per person-km is evaluated using: (a) data from previous evacuation: information from Soufriere evacuation (Guadeloupe Island 1976) and Mississauga (1979), added to Hans and Sell's data: no road accident occurred for a sample of 1,500,000 persons; (b) national recording system for motor vehicle accident: the rates of 2.2 10 -8 deaths per person-km and 32 10 -8 injuries per person-km is calculated as an average. These last rates in France overestimate the number of casualties. A reasonable hypothesis is to assume that the probability of road accident occurrence follows a Poisson distribution, as these events are independent and unfrequent, as no accident was observed in a sample of 1,500,000 persons the probability is between 0 and an upper value of 0.24 10 -8 deaths per person-km and 3.29 10 -8 injuries per person-km. The average and maximum population involved within different radii around French and U.S. Nuclear power sites are taken as a sample size in order to study the total risk of deaths and injuries in the hypothesis of an evacuation being necessary to protect the populations

  20. Aeromedical Evacuation: Validating Civil Reserve Air Fleet

    Science.gov (United States)

    2009-02-25

    flight nurses and three medical technicians) is added for AE missions. The aeromedical evacuation crew (AEC) may be pared and tailored as required in... Biosecurity and Bioterrorism: Biodefense Strategy, Practice and Science, Volume 5, Number 4, 2007: 319-325. 34 IAT.R 0554 General Accounting Office

  1. An adaptive simulation tool for evacuation scenarios

    NARCIS (Netherlands)

    Formolo, Daniel; van der Wal, C. Natalie

    2017-01-01

    Building useful and efficient models and tools for a varied audience, such as evacuation simulators for scientists, engineers and crisis managers, can be tricky. Even good models can fail in providing information when the user’s tools for the model are scarce of resources. The aim of this work is to

  2. Evacuating the Area of a Hurricane

    Centers for Disease Control (CDC) Podcasts

    2006-08-10

    If a hurricane warning is issued for your area, or authorities tell you to evacuate, take only essential items. If you have time, turn off gas, electricity, and water and disconnect appliances.  Created: 8/10/2006 by Emergency Communications System.   Date Released: 10/10/2007.

  3. Diffusion of gases in metal containing carbon aerogels

    Energy Technology Data Exchange (ETDEWEB)

    Marques, L.M.; Conceicao, F.L.; Carrott, M.M.L. Ribeiro; Carrott, P.J.M. [Evora Univ. (Portugal). Centro de Quimica de Evora

    2011-02-15

    Carbon aerogels containing Fe, Ni, Cu or no metal were prepared by carbonisation of polymer aerogels synthesised from 2,4-dihydroxybenzoic acid and formaldehyde and modified by CVD of benzene. Uptakes and diffusion coefficients of CO{sub 2}, CH{sub 4}, N{sub 2} and O{sub 2} were measured and the results compared with those obtained using a commercial carbon molecular sieve. The results indicated that the diffusion of light gas molecules in carbon aerogels cannot be interpreted solely on the basis of micropore diffusion, but that the very high mesopore volumes of the aerogel monoliths exert a strong influence on the kinetics of diffusion in these materials. The mesoporosity is decreased when the % solids used during synthesis of the polymer precursor increases and this resulted in kinetic behaviour which was more similar to that predicted by Fickian or LDF models. Increasing % solids was also accompanied by generally slower diffusion rates and generally lower uptakes. The single gas uptakes and diffusion coefficients could be altered by varying the % solids used during synthesis of the polymer precursor, by introducing different metals into the polymer hydrogel by ion exchange, or by CVD of benzene on the carbon aerogel. (author)

  4. Efficiently dense hierarchical graphene based aerogel electrode for supercapacitors

    Science.gov (United States)

    Wang, Xin; Lu, Chengxing; Peng, Huifen; Zhang, Xin; Wang, Zhenkun; Wang, Gongkai

    2016-08-01

    Boosting gravimetric and volumetric capacitances simultaneously at a high rate is still a discrepancy in development of graphene based supercapacitors. We report the preparation of dense hierarchical graphene/activated carbon composite aerogels via a reduction induced self-assembly process coupled with a drying post treatment. The compact and porous structures of composite aerogels could be maintained. The drying post treatment has significant effects on increasing the packing density of aerogels. The introduced activated carbons play the key roles of spacers and bridges, mitigating the restacking of adjacent graphene nanosheets and connecting lateral and vertical graphene nanosheets, respectively. The optimized aerogel with a packing density of 0.67 g cm-3 could deliver maximum gravimetric and volumetric capacitances of 128.2 F g-1 and 85.9 F cm-3, respectively, at a current density of 1 A g-1 in aqueous electrolyte, showing no apparent degradation to the specific capacitance at a current density of 10 A g-1 after 20000 cycles. The corresponding gravimetric and volumetric capacitances of 116.6 F g-1 and 78.1 cm-3 with an acceptable cyclic stability are also achieved in ionic liquid electrolyte. The results show a feasible strategy of designing dense hierarchical graphene based aerogels for supercapacitors.

  5. Diffusion of gases in metal containing carbon aerogels

    International Nuclear Information System (INIS)

    Marques, L.M.; Conceicao, F.L.; Carrott, M.M.L. Ribeiro; Carrott, P.J.M.

    2011-01-01

    Carbon aerogels containing Fe, Ni, Cu or no metal were prepared by carbonisation of polymer aerogels synthesised from 2,4-dihydroxybenzoic acid and formaldehyde and modified by CVD of benzene. Uptakes and diffusion coefficients of CO 2 , CH 4 , N 2 and O 2 were measured and the results compared with those obtained using a commercial carbon molecular sieve. The results indicated that the diffusion of light gas molecules in carbon aerogels cannot be interpreted solely on the basis of micropore diffusion, but that the very high mesopore volumes of the aerogel monoliths exert a strong influence on the kinetics of diffusion in these materials. The mesoporosity is decreased when the % solids used during synthesis of the polymer precursor increases and this resulted in kinetic behaviour which was more similar to that predicted by Fickian or LDF models. Increasing % solids was also accompanied by generally slower diffusion rates and generally lower uptakes. The single gas uptakes and diffusion coefficients could be altered by varying the % solids used during synthesis of the polymer precursor, by introducing different metals into the polymer hydrogel by ion exchange, or by CVD of benzene on the carbon aerogel. (author)

  6. Modeling silica aerogel optical performance by determining its radiative properties

    Directory of Open Access Journals (Sweden)

    Lin Zhao

    2016-02-01

    Full Text Available Silica aerogel has been known as a promising candidate for high performance transparent insulation material (TIM. Optical transparency is a crucial metric for silica aerogels in many solar related applications. Both scattering and absorption can reduce the amount of light transmitted through an aerogel slab. Due to multiple scattering, the transmittance deviates from the Beer-Lambert law (exponential attenuation. To better understand its optical performance, we decoupled and quantified the extinction contributions of absorption and scattering separately by identifying two sets of radiative properties. The radiative properties are deduced from the measured total transmittance and reflectance spectra (from 250 nm to 2500 nm of synthesized aerogel samples by solving the inverse problem of the 1-D Radiative Transfer Equation (RTE. The obtained radiative properties are found to be independent of the sample geometry and can be considered intrinsic material properties, which originate from the aerogel’s microstructure. This finding allows for these properties to be directly compared between different samples. We also demonstrate that by using the obtained radiative properties, we can model the photon transport in aerogels of arbitrary shapes, where an analytical solution is difficult to obtain.

  7. Van der Waal Interactions in Ultrafine Nanocellulose Aerogels

    Science.gov (United States)

    Fritch, Byron; Bradley, Derek; Kidd, Tim

    Nanocellulose aerogels have shown an ability to be used in many different applications ranging from oil sponges to conductive materials to possibly a low calorie food substitute. Not much is known about the structural and physical property changes that occur when the composition of the aerogel changes. We studied what properties change when the aerogel amounts change, as well as how sticky the aerogels are and how strong they are. The higher concentrations appeared to have more plate-like structures while the lower concentrations had a more fibrous material. These fibers in the low concentrations had a smaller diameter than a human hair. Only the low concentration aerogels were able to stick to a glass surface in the adhesion test, but were able to support a mass much larger than their own. These low concentrations also would stick to your finger when lightly touched. Preliminary tests show that a concentration that is not too low, but not too high, is best for tensile strength. All concentrations were able to hold many times their own mass. Cellulose should be studied more because it is a renewable material and is easily accessed. Nanocellulose is also not environmentally dangerous allowing it to be used in applications involving humans and the environment like noted above. National Science Foundation Grant DMR-1410496.

  8. Optimal control and performance of photovoltachromic switchable glazing for building integration in temperate climates

    International Nuclear Information System (INIS)

    Favoino, Fabio; Fiorito, Francesco; Cannavale, Alessandro; Ranzi, Gianluca; Overend, Mauro

    2016-01-01

    Highlights: • The features and properties of photovoltachromic switchable glazing are presented. • The different possible control strategies for the switchable glazing are presented. • Thermal and daylight performance are co-simulated for rule-based and optimal control. • A novel building performance simulation framework is developed for this aim. • Switchable glazing performance is compared for different controls and climates. - Abstract: The development of adaptive building envelope technologies, and particularly of switchable glazing, can make significant contributions to decarbonisation targets. It is therefore essential to quantify their effect on building energy use and indoor environmental quality when integrated into buildings. The evaluation of their performance presents new challenges when compared to conventional “static” building envelope systems, as they require design and control aspects to be evaluated together, which are also mutually interrelated across thermal and visual physical domains. This paper addresses these challenges by presenting a novel simulation framework for the performance evaluation of responsive building envelope technologies and, particularly, of switchable glazing. This is achieved by integrating a building energy simulation tool and a lighting simulation one, in a control optimisation framework to simulate advanced control of adaptive building envelopes. The performance of a photovoltachromic glazing is evaluated according to building energy use, Useful Daylight Illuminance, glare risk and load profile matching indicators for a sun oriented office building in different temperate climates. The original architecture of photovoltachromic cell provides an automatic control of its transparency as a function of incoming solar irradiance. However, to fully explore the building integration potential of photovoltachromic technology, different control strategies are evaluated, from passive and simple rule based controls, to

  9. FIRE EVACUATION FROM HIGH-RISE BUILDINGS

    Directory of Open Access Journals (Sweden)

    Korol'chenko Aleksandr Yakovlevich

    2012-10-01

    Full Text Available The authors argue that no collapse of structures is likely in the event of a fire emergency in multistoried buildings, rather, other fire-related factors may endanger the lives of people inside high-rise buildings exposed to the fire emergency, including open fire, sparks, high ambient temperature, smoke and toxic combustion products, reduced concentration of oxygen, and combined influence of various factors. In case of fire, the temperature inside buildings reaches 1100 °С. It exceeds the temperature of the ambient air acceptable for humans by far (70 °С. The experiments demonstrate that combustion products contain hundreds of toxic chemical compounds. The most hazardous of them include carbon oxide, carbon dioxide, chloride and cyanic hydrogen, aldehydes and acrolein. The author provides the pattern of their influence on the human body. The smoke consists of unburned particles of carbon and aerosols. The size of particles fluctuates within 0.05-50 MMK. Smoke produces a physiological and psychological impact on human beings. It has been proven that dangerous fire factors emerge within the first five to ten minutes of the emergency situation. Evacuation is the principal method of safety assurance. However, the velocity of propagation of smoke and heat is so high that even if the fire prevention system is in operation, people may be blocked both on the floors that are exposed to the fire and those that escape its propagation. New evacuation and rescue methods are recommended by the author. Various ways and methods of use of life-saving facilities are also provided. Safe evacuation is feasible from buildings where the number of stories does not exceed 10- 12. During evacuation, high density human streams are formed inside buildings, therefore, the period of stay in a burning building is increased. The calculations have proven that a two-minute delay of evacuation converts into a safe evacuation of only 13-15% of people. Low reliability of

  10. Information of the Home Office for the planning of evacuations

    International Nuclear Information System (INIS)

    1983-01-01

    This information contains the legal basis, scope and jurisdiction for evacuations in cases of accident. The general evacuation plan must schedule the following: private and public transport, information equipment, supply and care services, evacuation routes and traffic control checkpoints, etc. Particular evacuation plans must be established e.g. for nuclear plants and barrages. The planning is based on a survey of measures represented by a flowchart or a checklist. (HSCH) [de

  11. The effect of glazing and aging on the surface properties of CAD/CAM resin blocks.

    Science.gov (United States)

    Tekçe, Neslihan; Fidan, Sinan; Tuncer, Safa; Kara, Dilan; Demirci, Mustafa

    2018-02-01

    To investigate the effect of accelerated aging on surface properties of glazed CAD/CAM resin blocks using a 2D surface profilometer and a 3D non-contact optical profilometer. Three types of CAD/CAM resin restorative materials, LAVA Ultimate (3M ESPE, St Paul, MN, USA), VITA Enamic (Vita Zahnfabrik H. Rauter, Bad Säckingen, Germany), and Cerasmart (GC Corparation, Tokyo, Japan) were used for this study. CAD/CAM blocks were cut in 3-mm thickness slabs and divided into three groups; Group 1: control group (specimens polished with 600 grit SCI paper); Group 2: specimens sandblasted, silanized, and glazed with Optiglaze Color (GC); Group 3: glazed specimens subjected to 5000 thermocycles (n=15). The surface roughness (R a and R z ) was evaluated using a profilometer and a 3D scanning instrument. Data were analyzed using two-way ANOVA and Tukey's post-hoc test ( P .05). For VITA and Cerasmart, the specimens in Group 1 exhibited significantly higher R a values than Group 2 ( P .05). Glaze material Optiglaze Color makes CAD/CAM resin surfaces smooth and glazed CAD/CAM surfaces seem resistant to deterioration under 5000 thermocycles.

  12. Ceramic glaze analysis by simultaneous in-beam PGAA and XRFS

    International Nuclear Information System (INIS)

    Anderson, D.L.

    1995-01-01

    Twenty-one ready-to-use hobby glazes, of which 18 were labeled 'safe for food containers' (SFFC), were analyzed for Al, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, Gd, Hf, K, Mn, Na, Pb, Si, Sm, Sr, Ti, Zn, and Zr by neutron capture prompt γ-ray activation analysis (PGAA). Simultaneously, Pb was also determined by X-ray fluorescence spectrometry (XRFS) using Pb K X-rays induced by the γ-ray component of the neutron beam. The XRFS limits of detection were 200-400 μg Pb x g -1 (dry weight), a factor of ∼100 better than those for PGAA. Pb concentrations (by dry weight: with weight losses ranging from 28 to 49% after air-drying) found were 0.16-27.2% in the SFFC glazes and 0.86-32% in the other glazes. The SFFC glazes contained from -1 , and Co, Cr and Cu (elements which may enhance Pb leaching from fired glazes) were found in concentrations up to 1.2, 2.7, and 5.6%, respectively. Method accuracy was demonstrated with the analysis of soil, fly ash, and glass standard reference materials. (author) 13 refs.; 2 figs.; 3 tabs

  13. Aircraft industry workers in evacuation: conditions of life of evacuated plants' workers in 1941-1945

    Directory of Open Access Journals (Sweden)

    Михаил Юрьевич Мухин

    2010-09-01

    Full Text Available The article is devoted to the work of the factories in 1941-1945 in the evacuation. The author analyzes the living conditions of workers in evacuated aviation plants, their daily life, maintenance, etc. The author concludes that in the early years of the War the conditions of life of the aviation industry's workers were very difficult, and the welfare and financial situation improved in 1944, the sure sign of fracture in the Second world war.

  14. 21 CFR 888.4220 - Cement monomer vapor evacuator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cement monomer vapor evacuator. 888.4220 Section... (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.4220 Cement monomer vapor evacuator. (a) Identification. A cement monomer vapor evacuator is a device intended for use during surgery to contain or remove...

  15. 21 CFR 876.4370 - Gastroenterology-urology evacuator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Gastroenterology-urology evacuator. 876.4370... (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4370 Gastroenterology-urology evacuator. (a) Identification. A gastroenterology-urology evacuator is a device used to remove...

  16. Preparation of sponge-reinforced silica aerogels from tetraethoxysilane and methyltrimethoxysilane for oil/water separation

    Science.gov (United States)

    Li, Ming; Jiang, Hongyi; Xu, Dong

    2018-04-01

    Polyurethane sponge-reinforced silica aerogels based on tetraethoxysilane (TEOS) and methyltrimethoxysilane (MTMS) were fabricated by a facile method through sol-gel reaction followed by ambient pressure drying. In sponge-reinforced silica aerogels, nanoporous aerogel aggregates fill in the pores of polyurethane sponge. The sponge-reinforced aerogels are hydrophobic and oleophilic and show extremely high absorption for machine oil (10.6 g g‑1 for TEOS-based aerogel and 9.2 g g‑1 for MTMS-based aerogel). In addition, the sponge-reinforced aerogel composites exhibit notable improvements with regards to mechanical properties. The compressive strength was enhanced obviously up to about 349 KPa for TEOS-based aerogel and 60 KPa for MTMS-based aerogel. Specially, sponge-reinforced silica aerogels based on MTMS drastically shrank upon loading and then recovered to the original size when unloaded. The property differences of the sponge-reinforced silica aerogels caused by the two precursors were discussed in terms of morphologies, pore size distributions and chemical structure.

  17. Synthesis of nano-Au doped SiO2 aerogels by seeding method

    International Nuclear Information System (INIS)

    Ren Hongbo; Wan Xiaobo; Zhang Lin; Du Aiming; Xiu Peng

    2006-01-01

    A new approach to synthesize gold nano cluster doped aerogel on the basis of surface-catalyzed reduction of metal ions was described. Au nano particles were formed in a silica aerogel matrix by hydroxylamine seeding method of reducing gold ions on the silica colloidal surface. Subsequently, the pH value of system was adjusted to about 7-8, the gel formed within 2 h. After aging for 2 d, the gels were washed in aceton, and then dried supercritically (from CO 2 ) to yield aerogels. The reduction process was attributed to hydroxylamine-induced surface catalysis. Au clusters in the aerogel monoliths were characterized with optical adsorption, transmission electron microscopy. These techniques have shown the cluster size and weight content in the aerogels. Brunauer-emmett-teller surface area measurements show that the specific surface area of silica aerogels and doped aerogels are higher than 800 m 2 /g. (authors)

  18. A Special Material or a New State of Matter: A Review and Reconsideration of the Aerogel

    Directory of Open Access Journals (Sweden)

    Jun Shen

    2013-03-01

    Full Text Available The ultrahighly nanoporous aerogel is recognized as a state of matter rather than as a functional material, because of its qualitative differences in bulk properties, transitional density and enthalpy between liquid and gas, and diverse chemical compositions. In this review, the characteristics, classification, history and preparation of the aerogel were introduced. More attention was paid to the sol-gel method for preparing different kinds of aerogels, given its important role on bridging the synthetic parameters with the properties. At last, preparation of a novel single-component aerogel, design of a composite aerogel and industrial application of the aerogel were regarded as the research tendency of the aerogel state in the near future.

  19. Effect of catalyst on melamine-formaldehyde organic aerogel

    International Nuclear Information System (INIS)

    Sun Zhipeng; Yang Xi; Fu Zhibing; Zhong Minglong; Wang Chaoyang; Ma Kangfu; Huang Xiaoli; Chang Lijuan

    2013-01-01

    A series of melamine-formaldehyde(MF) organic aerogel templates were prepared with different categories and concentration of catalyst. Their molecular structure, thermal stability and pore structure were tested by Fourier transform infrared spectroscopy, thermogravimetric analysis and nitrogen adsorption. It is indicated that the type and concentration of catalyst do not affect molecular structure and thermal stability of the MF organic aerogel template. The specific surface area and pore volume of the MF organic aerogel template using Na 2 CO 3 as catalyst are higher than those using NaOH, NaHCO 3 as catalyst. When the ratio of the concentration of melamine to that of catalyst is 500, the specific surface area is maximized. (authors)

  20. Trapping and aerogelation of nanoparticles in negative gravity hydrocarbon flames

    International Nuclear Information System (INIS)

    Chakrabarty, Rajan K.; Novosselov, Igor V.; Beres, Nicholas D.; Moosmüller, Hans; Sorensen, Christopher M.; Stipe, Christopher B.

    2014-01-01

    We report the experimental realization of continuous carbon aerogel production using a flame aerosol reactor by operating it in negative gravity (−g; up-side-down configuration). Buoyancy opposes the fuel and air flow forces in −g, which eliminates convectional outflow of nanoparticles from the flame and traps them in a distinctive non-tipping, flicker-free, cylindrical flame body, where they grow to millimeter-size aerogel particles and gravitationally fall out. Computational fluid dynamics simulations show that a closed-loop recirculation zone is set up in −g flames, which reduces the time to gel for nanoparticles by ≈10 6  s, compared to positive gravity (upward rising) flames. Our results open up new possibilities of one-step gas-phase synthesis of a wide variety of aerogels on an industrial scale.

  1. Trapping and aerogelation of nanoparticles in negative gravity hydrocarbon flames

    Energy Technology Data Exchange (ETDEWEB)

    Chakrabarty, Rajan K., E-mail: rajan.chakrabarty@gmail.com [Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130 (United States); Laboratory for Aerosol Science, Spectroscopy, and Optics, Desert Research Institute, Nevada System of Higher Education, Reno, Nevada 89512 (United States); Novosselov, Igor V. [Department of Mechanical Engineering, University of Washington, Seattle, Washington 98195 (United States); Enertechnix Inc., Maple Valley, Washington 98068 (United States); Beres, Nicholas D.; Moosmüller, Hans [Laboratory for Aerosol Science, Spectroscopy, and Optics, Desert Research Institute, Nevada System of Higher Education, Reno, Nevada 89512 (United States); Sorensen, Christopher M. [Condensed Matter Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas 66506 (United States); Stipe, Christopher B. [TSI Incorporated, 500 Cardigan Rd, Shoreview, Minnesota 55126 (United States)

    2014-06-16

    We report the experimental realization of continuous carbon aerogel production using a flame aerosol reactor by operating it in negative gravity (−g; up-side-down configuration). Buoyancy opposes the fuel and air flow forces in −g, which eliminates convectional outflow of nanoparticles from the flame and traps them in a distinctive non-tipping, flicker-free, cylindrical flame body, where they grow to millimeter-size aerogel particles and gravitationally fall out. Computational fluid dynamics simulations show that a closed-loop recirculation zone is set up in −g flames, which reduces the time to gel for nanoparticles by ≈10{sup 6} s, compared to positive gravity (upward rising) flames. Our results open up new possibilities of one-step gas-phase synthesis of a wide variety of aerogels on an industrial scale.

  2. Aerogel Hybrid Composite Materials: Designs and Testing for Multifunctional Applications

    Science.gov (United States)

    Williams, Martha K.; Fesmire, James E.

    2016-01-01

    This webinar will introduce the broad spectrum of aerogel composites and their diverse performance properties such as reduced heat transfer to energy storage, and expands specifically on the aerogel/fiber laminate systems and testing methodologies. The multi-functional laminate composite system, AeroFiber, and its construction is designed by varying the type of fiber (e.g. polyester, carbon, Kevlar®, Spectra® or Innegral(TradeMark) and combinations thereof), the aerogel panel type and thickness, and overall layup configuration. The combination and design of materials may be customized and tailored to achieve a range of desired properties in the resulting laminate system. Multi-functional properties include structural strength, impact resistance, reduction in heat transfer, increased fire resistance, mechanical energy absorption, and acoustic energy dampening. Applications include aerospace, aircraft, automotive, boating, building and construction, lightweight portable structures, liquefied natural gas, cryogenics, transportation and energy, sporting equipment, and military protective gear industries.

  3. Aerogel-Based Insulation for Industrial Steam Distribution Systems

    Energy Technology Data Exchange (ETDEWEB)

    John Williams

    2011-03-30

    Thermal losses in industrial steam distribution systems account for 977 trillion Btu/year in the US, more than 1% of total domestic energy consumption. Aspen Aerogels worked with Department of Energy’s Industrial Technologies Program to specify, develop, scale-up, demonstrate, and deliver Pyrogel XT®, an aerogel-based pipe insulation, to market to reduce energy losses in industrial steam systems. The product developed has become Aspen’s best selling flexible aerogel blanket insulation and has led to over 60 new jobs. Additionally, this product has delivered more than ~0.7 TBTU of domestic energy savings to date, and could produce annual energy savings of 149 TBTU by 2030. Pyrogel XT’s commercial success has been driven by it’s 2-4X better thermal performance, improved durability, greater resistance to corrosion under insulation (CUI), and faster installation times than incumbent insulation materials.

  4. Determination of levels of polychlorinated biphenyls (PCBs) present in caulk and window glazing material samples from older buildings

    Science.gov (United States)

    Levels of polychlorinated biphenyls (PCBs) in caulk and window glazing material samples from older buildings were determined, using a method developed for this purpose. This method was evaluated by analyzing a combination of 47 samples of caulk, glazing materials, including quali...

  5. System and method for 3D printing of aerogels

    Science.gov (United States)

    Worsley, Marcus A.; Duoss, Eric; Kuntz, Joshua; Spadaccini, Christopher; Zhu, Cheng

    2016-03-08

    A method of forming an aerogel. The method may involve providing a graphene oxide powder and mixing the graphene oxide powder with a solution to form an ink. A 3D printing technique may be used to write the ink into a catalytic solution that is contained in a fluid containment member to form a wet part. The wet part may then be cured in a sealed container for a predetermined period of time at a predetermined temperature. The cured wet part may then be dried to form a finished aerogel part.

  6. Ultrasound propagation in dense aerogels filled with liquid 4He

    International Nuclear Information System (INIS)

    Matsumoto, K; Ohmori, K; Abe, S; Kanamori, K; Nakanishi, K

    2012-01-01

    Longitudinal ultrasound propagation was studied in dense aerogels filled with liquid 4 He. Sound velocity and attenuation were measured at the frequency of 6 MHz in both normal and superfluid phases. Pressure dependence of velocity and attenuation were also studied. Studied aerogels had porosities about 85%. They had two different types of structure, tangled strand structure and aggregated particles structure. The pore size distributions were narrow. Reduction of superfluid transition temperature mainly depended on not porosity but mean pore size. The structure of gel played an important role in sound velocity and attenuation.

  7. Formation and pore structure of boron nitride aerogels

    International Nuclear Information System (INIS)

    Lindquist, D.H.; Borek, T.T.; Kramer, S.J.; Kramer, S.J.; Naruta, C.K.; Johnson, G.; Schaeffer, R.; Smith, D.M.; Paine, R.T.

    1990-01-01

    This paper reports gels containing a poly(borazinyl amine) and tetrahydrofuran processed by CO 2 supercritical drying techniques followed by pyrolysis. The resulting BN ceramic aerogels are highly porous, and the microstructure, porosity, and surface area characteristics have been examined. The aerogels show excellent thermal stability exhibiting surface areas in excess of 350 m 2 /g and porosities greater than 0.8 even when heated in argon at 1500 degrees C for 8 h. By removing solvent via evaporation before supercritical drying, the mean pore radius can be varied between 3.6 and 10 nm

  8. Using of Aerogel to Improve Thermal Insulating Properties of Windows

    Science.gov (United States)

    Valachova, Denisa; Zdrazilova, Nada; Panovec, Vladan; Skotnicova, Iveta

    2018-06-01

    For the best possible thermal-technical properties of building structures it is necessary to use materials with very low thermal conductivity. Due to the increasing thermal-technical requirements for building structures, the insulating materials are developed. One of the modern thermal insulating materials is so-called aerogel. Unfortunately, this material is not used in the field of external thermal insulation composite systems because of its price and its properties. The aim of this paper is to present possibilities of using this insulating material in the civil engineering - specifically a usage of aerogel in the production of windows.

  9. Soft tissue adhesion of polished versus glazed lithium disilicate ceramic for dental applications.

    Science.gov (United States)

    Brunot-Gohin, C; Duval, J-L; Azogui, E-E; Jannetta, R; Pezron, I; Laurent-Maquin, D; Gangloff, S C; Egles, C

    2013-09-01

    Ceramics are widely used materials for prosthesis, especially in dental fields. Despite multiple biomedical applications, little is known about ceramic surface modifications and the resulting cell behavior at its contact. The aim of this study is to evaluate the biological response of polished versus glazed surface treatments on lithium disilicate dental ceramic. We studied a lithium disilicate ceramic (IPS e.max(®) Press, Ivoclar Vivadent) with 3 different surface treatments: raw surface treatment, hand polished surface treatment, and glazed surface treatment (control samples are Thermanox(®), Nunc). In order to evaluate the possible modulation of cell response at the surface of ceramic, we compared polished versus glazed ceramics using an organotypic culture model of chicken epithelium. Our results show that the surface roughness is not modified as demonstrated by equivalent Ra measurements. On the contrary, the contact angle θ in water is very different between polished (84°) and glazed (33°) samples. The culture of epithelial tissues allowed a very precise assessment of histocompatibility of these interfaces and showed that polished samples increased cell adhesion and proliferation as compared to glazed samples. Lithium disilicate polished ceramic provided better adhesion and proliferation than lithium disilicate glazed ceramic. Taken together, our results demonstrate for the first time, how it is possible to use simple surface modifications to finely modulate the adhesion of tissues. Our results will help dental surgeons to choose the most appropriate surface treatment for a specific clinical application, in particular for the ceramic implant collar. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  10. Environmental, economic and energy analysis of double glazing with a circulating water chamber in residential buildings

    International Nuclear Information System (INIS)

    Gil-Lopez, Tomas; Gimenez-Molina, Carmen

    2013-01-01

    Highlights: ► Glazed façade area is the part that produces greatest energy losses and gains. ► A potential for energy savings has been detected in residential buildings. ► Active glazing comprising two laminated glass panels with a circulating water chamber. ► Analysis of energy performance, economic viability and impact on carbon footprint. ► Natural gas condensing boilers is the less contaminating and more efficient option. -- Abstract: In general, the glazed façade area of a building is the part that produces the greatest energy losses and gains. The basic aim of this work is to achieve a more efficient heat control in closed spaces. To this end, an exhaustive study has been made of active glazing comprising two laminated glass panels with a circulating water chamber. Not only has the energy consumption been analysed but also the energy efficiency according to fuel type, the amount of CO 2 emitted into the atmosphere and the economic cost. The results of this study, from the points of view of economic feasibility and energy efficiency, show that the solution of double glazing with a circulating water chamber is a less polluting and more efficient option than the systems currently used. This solution is able to reduce the energy losses and gains that are produced through the glazed façade of a building by 18.26% for calorific and frigorific energy compared to the total consumption of the building. The layout of the proposed installation facilitates its integration into any type of residential building, either under construction or being renovated. Moreover, its zero visual impact means it can even be implemented in places with strict town-planning regulations.

  11. Effect of self-glazing on reducing the radioactivity levels of red mud based ceramic materials

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Shuo [College of Material Science and Engineering, Guilin University of Technology, Guilin, Guangxi 541004 (China); Wu, Bolin, E-mail: wubolin3211@gmail.com [College of Material Science and Engineering, Guilin University of Technology, Guilin, Guangxi 541004 (China)

    2011-12-30

    Graphical abstract: Self-glazing red mud based ceramic materials (RMCM) were produced by normal pressure sintering process using the main raw materials of red mud. The properties of the RMCM samples were investigated by the measurements of mechanical properties, radiation measurement, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that the self-glazing RMCM have good mechanical properties (water absorption and apparent porosity approached zero; bulk density, 2.94 g/cm{sup 3}; compressive strength, 78.12 MPa). The radiation level has clear change regularity that the radioactivity levels of red mud (6360 Bq) are obvious declined, and can be reduced to that of the natural radioactive background of Guilin Karst landform, China (3600 Bq). It will not only consume large quantities of red mud, but also decrease the production cost of self-glazing RMCM. And the statement of this paper will offer effective ways to reduce the radioactivity level of red mud. Highlights: Black-Right-Pointing-Pointer The self-glazing phenomenon in red mud system was first discovered in our research. Black-Right-Pointing-Pointer Radiation levels of red mud can be reduced efficiently by self-glazing layer. Black-Right-Pointing-Pointer Red mud based ceramic materials will not cause harm to environment and humans. Black-Right-Pointing-Pointer This research possesses important economic significances to aluminum companies. - Abstract: Self-glazing red mud based ceramic materials (RMCM) were produced by normal pressure sintering process using the main raw materials of red mud. The properties of the RMCM samples were investigated by the measurements of mechanical properties, radiation measurement, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that the self-glazing RMCM have good mechanical properties (water absorption and apparent porosity approached zero; bulk density, 2.94 g/cm{sup 3}; compressive strength, 78.12 MPa). The radiation

  12. PV-PCM integration in glazed building. Co-simulation and genetic optimization study

    DEFF Research Database (Denmark)

    Elarga, Hagar; Dal Monte, Andrea; Andersen, Rune Korsholm

    2017-01-01

    . An exploratory step has also been considered prior to the optimization algorithm: it evaluates the energy profiles before and after the application of PCM to PV module integrated in glazed building. The optimization analysis investigate parameters such as ventilation flow rates and time schedule to obtain......The study describes a multi-objective optimization algorithm for an innovative integration of forced ventilated PV-PCM modules in glazed façade buildings: the aim is to identify and optimize the parameters that most affect thermal and energy performances. 1-D model, finite difference method FDM...

  13. Highly insulating glazing in new multi-storey buildings; Hoejisolerende glaspartier i nye etageboliger

    Energy Technology Data Exchange (ETDEWEB)

    Engelund Thomsen, K.; Schmidt, H.; Aggerholm, S.

    2001-07-01

    The purpose of this report is to illustrate how highly insulating types of glazing can be used in multi-storey buildings for housing in new ways. These are energy efficient and provide good indoor climate and also satisfy requirements to high architectural quality. The project has resulted in a number of design proposal demonstrating how new types of glazing can be fitted into multi-storey buildings and how new facade expressions, space and lighting effects can be obtained by using highly insulating glass areas. The project is collaboration between the architects Boje Lundgaard and Lene Tranberg's Tegnestue, KAB Bygge og Boligadministration and Danish Building and Urban Research. Calculations of heat demand suggest that it is possible to meet the targets outlined in the Danish Government's action plan for energy. Energy 21 by using new types of highly insulating glazing in new buildings. Another 33% reduction of the heating demand is targeted in relation to existing requirements in the Danish Building Regulations 1995 (BR 95) and the Danish Building Regulations for Small Dwellings 1998 (BR-S 98). The project builds on experience gained from 'High-insulated Glass House' (Wittchen and Aggerholm, 1999) built on the housing estage Egebjerggaard in Ballerup, a suburb of Copenhagen. Examples of existing multi-storey buildings with glass facades show extensive use of glazing as early as 1830 in Spain. Walls preceding the curtain wall were built from wood and glass and rested on stone corbels at about 1 m from the load-bearing facade. The first multi-storey buildings with facades entirely made from glass date from the 1920s. The architect Le Corbusier was the first to create a building system that facilitated the construction of non-loadbearing facades. Various conditions must be especially considered at the design of facades with highly insulating glass areas, i.a. type of glass and glazing, solar shadings, frame constructions and airtightness

  14. Study on sources of colored glaze of Xiyue Temple in Shanxi province by INAA and multivariable statistical analysis

    International Nuclear Information System (INIS)

    Cheng Lin; Feng Songlin

    2005-01-01

    The major, minor and trace elements in the bodies of ancient colored glazes which came from the site of Xiyue Temple and Lidipo kiln in Shanxi province, and were unearthed from the stratums of Song, Yuan, Ming, Early Qing and Late Qing dynasty were analyzed by instrumental neutron activation analysis (INAA). The results of multivariable statistical analyses show that the chemical compositions of the colored glaze bodies are steady from Song to Early Qing dynasty, but distinctly different from that in Late Qing. Probably, the sources of fired material of ancient colored glaze from Song to Early Qing came from the site of Xiyue Temple. The chemical compositions of three pieces of colored glazes in Ming dynasty and that in Late Qing are similar to that of Lidipo kiln. From this, authors could conclude that the sources of the materials of ancient coloured glazes of Xiyue Temple in Late Qing dynasty were fired in Lidipo kiln. (authors)

  15. Intelligent Transportation and Evacuation Planning A Modeling-Based Approach

    CERN Document Server

    Naser, Arab

    2012-01-01

    Intelligent Transportation and Evacuation Planning: A Modeling-Based Approach provides a new paradigm for evacuation planning strategies and techniques. Recently, evacuation planning and modeling have increasingly attracted interest among researchers as well as government officials. This interest stems from the recent catastrophic hurricanes and weather-related events that occurred in the southeastern United States (Hurricane Katrina and Rita). The evacuation methods that were in place before and during the hurricanes did not work well and resulted in thousands of deaths. This book offers insights into the methods and techniques that allow for implementing mathematical-based, simulation-based, and integrated optimization and simulation-based engineering approaches for evacuation planning. This book also: Comprehensively discusses the application of mathematical models for evacuation and intelligent transportation modeling Covers advanced methodologies in evacuation modeling and planning Discusses principles a...

  16. Evacuation of Bed-bound Patients-STEPS Simulations

    DEFF Research Database (Denmark)

    Madsen, Anne; Dederichs, Anne Simone

    2016-01-01

    Fires in hospitals occur, and evacuation of bed-bound patients might be necessary in case of emergency. The current study concerns the evacuation of bed-bound patients from a fire section in a hospital using hospital porters. The simulations are performed using the STEPS program. The aim...... of the study is to investigate the evacuation time of bed-bound hospital patients using different walking speeds from the literature, and the influence of the number of hospital porters on the total evacuation times of bed-bound patients. Different scenarios were carried out with varying staff......-to-patient ratios that simulate the horizontal evacuation of 40 bed-bound patients into a different fire section. It was found that the staff-to-patient-ratio affects the total evacuation times. However, the total evacuation times do not decrease linearly and a saturation effect is seen at a staff-to-patient ratio...

  17. Flexible, highly graphitized carbon aerogels based on bacterial cellulose/lignin: Catalyst-free synthesis and its application in energy storage devices

    KAUST Repository

    Xu, Xuezhu; Zhou, Jian; Nagaraju, Doddahalli H.; Jiang, Long; Marinov, Val R.; Lubineau, Gilles; Alshareef, Husam N.; Oh, Myungkeun

    2015-01-01

    Currently, most carbon aerogels are based on carbon nanotubes (CNTs) or graphene, which are produced through a catalyst-assisted chemical vapor deposition method. Biomass based organic aerogels and carbon aerogels, featuring low cost, high

  18. Evacuation behavior and Three Mile Island.

    Science.gov (United States)

    Cutter, S; Barnes, K

    1982-06-01

    The responses of the residents to the nuclear power plant arcident at Three Mile Island, Pennsylvania illustrate the factors influencing pre-impact coping responses of populations exposed to technological hazards. Confusion itnd ambiguous information influenced both the decision to evaluate and to remain in place. Proximity to the facility, stage in life cycle and the actions of friends and neighbors influenced the decision to evacuate.

  19. Thermal Simulation of a Zero Energy Glazed Pavilion in Sofia, Bulgaria. New Strategies for Energy Management by Means of Water Flow Glazing

    Science.gov (United States)

    del Ama Gonzalo, Fernando; Hernandez Ramos, Juan A.; Moreno, Belen

    2017-10-01

    The building sector is primarily responsible for a major part of total energy consumption. The European Energy Performance of Buildings Directives (EPBD) emphasized the need to reduce the energy consumption in buildings, and put forward the rationale for developing Near to Zero Energy Buildings (NZEB). Passive and active strategies help architects to minimize the use of active HVAC systems, taking advantage of the available natural resources such as solar radiation, thermal variability and daylight. The building envelope plays a decisive role in passive and active design strategies. The ideal transparent façade would be one with optical properties, such as Solar Heat Gain Coefficient (SHGC) and Visible Transmittance (VT), that could readily adapt in response to changing climatic conditions or occupant preferences. The aim of this article consists of describing the system to maintain a small glazed pavilion located in Sofia (Bulgaria) at the desired interior temperature over a whole year. The system comprises i) the use of Water Flow Glazing facades (WFG) and Radiant Interior Walls (RIW), ii) the use of free cooling devices along with traditional heat pump connected to photo-voltaic panels and iii) the use of a new Energy Management System that collects data and acts accordingly by controlling all components. The effect of these strategies and the use of active systems, like Water Flow Glazing, are analysed by means of simulating the prototype over one year. Summer and Winter energy management strategies are discussed in order to change the SHGC value of the Water Flow Glazing and thus, reduce the required energy to maintain comfort conditions.

  20. Evacuation exercise at the CERN Kindergarten

    CERN Document Server

    2001-01-01

    Every year fire evacuation exercises are organized through out CERN and our facility's Kindergarten is no exception. Just a few weeks ago, a fire simulation was carried out in the Kindergarten kitchen facility using synthetic smoke. The purpose of the exercise was to teach staff to react in a disciplined and professional manner when in the presence of danger. The simulation is always carried out at a random time so as to ensure that people in the area under the test are not aware of the exercise. For the Kindergarten the exercise was held early in the school year so as to train those who are new to the establishment. The evacuation was a complete success and all went as it was supposed to. When the children and teachers smelt smoke they followed the prescribed evacuation routes and left the building immediately. Once outside the situation was revealed as an exercise and everyone went back to business as usual, everyone that is, except the fire brigade and fire inspector. The fire brigade checked that the buil...

  1. Nuclear criticality evacuation with telemonitoring and microprocessors

    International Nuclear Information System (INIS)

    Fergus, R.W.; Moe, H.J. Sr.

    1979-01-01

    At Argonne National Laboratory, criticality alarms are required at widely separated locations to evacuate personnel in case of accident while emergency teams or maintenance personnel respond from a central location. The system functions have been divided in a similar manner. The alarm site hardware can independently detect a criticality and sound the evacuation signal while general monitoring and routine tests are handled by a communication link to a central monitoring station. The radiation detectors and evacuation sounders at each site are interconnected by a common two conductor cable in a unique telemonitoring format. This format allows both control and data information to be received or transmitted at any point on the cable which can be up to 3000 meters total length. The site microprocessor maintains a current data table, detects several faults, drives a printer, and communicates with the central telemonitoring station. The radiation detectors are made with plastic scintillators and photomultiplier tubes operated in a constant current mode with a 4 decade measurement range. The detectors also respond within microseconds to the criticality radiation burst. These characteristics can be tested with an internal light emitting diode either completely with a manual procedure or routinely with a system test initiated by the central monitoring station. Although the system was developed for a criticality alarm which requires reliable and redundant features, the basic techniques are useable for other monitoring and instrumentation applications

  2. Green synthesis of hybrid graphene oxide/microcrystalline cellulose aerogels and their use as superabsorbents

    International Nuclear Information System (INIS)

    Wei, Xiao; Huang, Ting; Yang, Jing-hui; Zhang, Nan; Wang, Yong; Zhou, Zuo-wan

    2017-01-01

    Highlights: • Hybrid GO/MCC aerogels were prepared using LiBr aqueous solution as the solvent. • GO was exfoliated by MCC through the strong interaction between them. • The adsorption ability of GO per unit mass in the hybrid aerogels was greatly enhanced. - Abstract: In this work, we developed a green synthesis method to prepare the hybrid aerogels containing graphene oxide (GO) and microcrystalline cellulose (MCC) using lithium bromide (LiBr) aqueous solution as the solvent, which insured the complete dissolution of MCC. The interaction between GO and MCC was investigated through different methods The results demonstrate that there is a strong interaction between GO and MCC molecules, which promotes the exfoliation of GO in the hybrid aerogels. The hybrid GO/MCC aerogels exhibit typical three dimensional porous structure and the pore morphology can be well adjusted by changing the content of GO. The adsorption ability of the hybrid aerogels was measured using methylene blue (MB) as an adsorbate. The results show that the adsorption ability of GO per unit mass is greatly enhanced compared with the pure GO aerogel, especially at relatively low GO content the adsorption amount of GO per unit mass is enhanced up to 2630 mg/g. Further results demonstrate that the hybrid GO/MCC aerogels still obey the pseudo-second-order adsorption model, which is similar to that of the pure GO aerogel. The mechanism for the amplified adsorption ability of GO in the hybrid GO/MCC aerogels is then analyzed.

  3. Synthesis of ZnO-CuO Nanocomposite Aerogels by the Sol-Gel Route

    Directory of Open Access Journals (Sweden)

    Rula M. Allaf

    2014-01-01

    Full Text Available The epoxide addition sol-gel method has been utilized to synthesize porous zinc-copper composite aerogels in the zinc-to-copper molar ratios of 50 : 50 to 90 : 10. A two-step mixing approach has been employed to produce aerogels composed of nano- to micrometer sized particles. The aerogels were characterized by ultrahigh resolution scanning electron microscopy, transmission electron microscopy, and powder X-ray diffraction. The as-synthesized aerogels had a thin flake- or petal-like microstructure comprised of clustered flakes on two size scales; they were identified as being crystalline with the crystalline species identified as copper nitrate hydroxide, zinc hydroxide chloride hydrate, and zinc hydroxide nitrate hydrate. Annealing of the aerogel materials at a relatively low temperature (400°C resulted in a complete phase transition of the material to give highly crystalline ZnO-CuO aerogels; the aerogels consisted of networked nanoparticles in the ~25–550 nm size range with an average crystallite size of ~3 nm and average crystallinity of 98%. ZnO-CuO aerogels are of particular interest due to their particular catalytic and sensing properties. This work emphasizes the versatility of this sol-gel route in synthesizing aerogels; this method offers a possible route for the fabrication of aerogels of different metal oxides and their composites.

  4. Green synthesis of hybrid graphene oxide/microcrystalline cellulose aerogels and their use as superabsorbents

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Xiao; Huang, Ting; Yang, Jing-hui; Zhang, Nan; Wang, Yong, E-mail: yongwang1976@163.com; Zhou, Zuo-wan

    2017-08-05

    Highlights: • Hybrid GO/MCC aerogels were prepared using LiBr aqueous solution as the solvent. • GO was exfoliated by MCC through the strong interaction between them. • The adsorption ability of GO per unit mass in the hybrid aerogels was greatly enhanced. - Abstract: In this work, we developed a green synthesis method to prepare the hybrid aerogels containing graphene oxide (GO) and microcrystalline cellulose (MCC) using lithium bromide (LiBr) aqueous solution as the solvent, which insured the complete dissolution of MCC. The interaction between GO and MCC was investigated through different methods The results demonstrate that there is a strong interaction between GO and MCC molecules, which promotes the exfoliation of GO in the hybrid aerogels. The hybrid GO/MCC aerogels exhibit typical three dimensional porous structure and the pore morphology can be well adjusted by changing the content of GO. The adsorption ability of the hybrid aerogels was measured using methylene blue (MB) as an adsorbate. The results show that the adsorption ability of GO per unit mass is greatly enhanced compared with the pure GO aerogel, especially at relatively low GO content the adsorption amount of GO per unit mass is enhanced up to 2630 mg/g. Further results demonstrate that the hybrid GO/MCC aerogels still obey the pseudo-second-order adsorption model, which is similar to that of the pure GO aerogel. The mechanism for the amplified adsorption ability of GO in the hybrid GO/MCC aerogels is then analyzed.

  5. Fabrication and characterization of Aerogel-Polydimethyl siloxane (PDMS) Insulation Film

    Science.gov (United States)

    Noh, Yeoung ah; Song, Sinae; Taik Kim, Hee

    2018-03-01

    The building has a large impact on the space heating demand and the indoor environment is affected by climate or daylight. Hence, silica aerogel has generally used as a film to reduce the coefficient of the window in the building. Silica aerogel is a suitable material to apply for insulation material with lower thermal conductivity than that of air to save interior energy. However expensive precursor and drying process were the main issue of the silica aerogel synthesis and practical usage. We attempt to fabricate aerogel insulation film for energy saving through the economic process under ambient pressure. Silica aerogel was synthesized from rice husk ash, which was an agricultural waste to be able to recycle. Taguchi design was used to optimize the parameters (amount of rice husk ash, pH, aging time) controlling the surface area of silica aerogel. The silica aerogel is prepared by sol-gel processing through acidic treatment and aging. The silica aerogel was obtained by modification of silica hydrogel surface and dry at ambient pressure. Finally, aerogel film was respectively fabricated by the different content of aerogel in polydimethylsiloxane (PDMS). Silica aerogel obtained 21 – 24nm average particle size was analyzed by SEM and silica aerogel with high surface area (832.26 m2/g), pore size ( 3.30nm ) was characterized by BET. Then silica Aerogel – PDMS insulation film with thermal conductivity (0.002 W/mK) was analyzed by thermal wave system. The study demonstrates an eco-friendly and low-cost route toward silica – PDMS insulation film with low thermal conductivity (0.002 W/mK).

  6. Aerogel-Based Insulation for High-Temperature Industrial Processes

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Owen Evans

    2011-10-13

    Under this program, Aspen Aerogels has developed an industrial insulation called Pyrogel HT, which is 4-5 times more thermally efficient than current non-aerogel technology. Derived from nanoporous silica aerogels, Pyrogel HT was specifically developed to address a high temperature capability gap not currently met with Aspen Aerogels{trademark} flagship product, Pyrogel XT. Pyrogel XT, which was originally developed on a separate DOE contract (DE-FG36-06GO16056), was primarily optimized for use in industrial steam processing systems, where application temperatures typically do not exceed 400 C. At the time, further improvements in thermal performance above 400 C could not be reasonably achieved for Pyrogel XT without significantly affecting other key material properties using the current technology. Cumulative sales of Pyrogel HT into domestic power plants should reach $125MM through 2030, eventually reaching about 10% of the total insulation market share in that space. Global energy savings would be expected to scale similarly. Over the same period, these sales would reduce domestic energy consumption by more than 65 TBtu. Upon branching out into all industrial processes in the 400 C-650 C regime, Pyrogel HT would reach annual sales levels of $150MM, with two-thirds of that being exported.

  7. Titania aerogel prepared by low temperature supercritical drying

    Czech Academy of Sciences Publication Activity Database

    Štengl, Václav; Bakardjieva, Snejana; Šubrt, Jan; Szatmáry, Lórant

    2006-01-01

    Roč. 91, 1-3 (2006), s. 1-6 ISSN 1387-1811 R&D Projects: GA MŠk(CZ) 1M0577 Institutional research plan: CEZ:AV0Z40320502 Keywords : aerogels * titanium oxide * supercritical drying Subject RIV: CA - Inorganic Chemistry Impact factor: 2.796, year: 2006

  8. Flexible Supercapacitors Based on Polyaniline Arrays Coated Graphene Aerogel Electrodes.

    Science.gov (United States)

    Yang, Yu; Xi, Yunlong; Li, Junzhi; Wei, Guodong; Klyui, N I; Han, Wei

    2017-12-01

    Flexible supercapacitors(SCs) made by reduced graphene oxide (rGO)-based aerogel usually suffer from the low energy density, short cycle life and bad flexibility. In this study, a new, synthetic strategy was developed for enhancing the electrochemical performances of rGO aerogel-based supercapacitor via electrodeposition polyaniline arrays on the prepared ultralight rGO aerogel. The novel hybrid composites with coated polyaniline (PANI) arrays growing on the rGO surface can take full advantage of the rich open-pore and excellent conductivity of the crosslinking framework structure of 3D rGO aerogel and high capacitance contribution from the PANI. The obtained hybrid composites exhibit excellent electrochemical performance with a specific capacitance of 432 F g -1 at the current density of 1 A g -1 , robust cycling stability to maintain 85% after 10,000 charge/discharge cycles and high energy density of 25 W h kg -1 . Furthermore, the flexible all-solid-state supercapacitor have superior flexibility and outstanding stability under different bending states from the straight state to the 90° status. The high-performance flexible all-solid-state SCs together with the lighting tests demonstrate it possible for applications in portable electronics.

  9. Aerogel-Based Antennas for Aerospace and Terrestrial Applications

    Science.gov (United States)

    Meador, Mary Ann (Inventor); Miranda, Felix (Inventor); Van Keuls, Frederick (Inventor)

    2016-01-01

    Systems and methods for lightweight, customizable antenna with improved performance and mechanical properties are disclosed. In some aspects, aerogels can be used, for example, as a substrate for antenna fabrication. The reduced weight and expense, as well as the increased ability to adapt antenna designs, permits a systems to mitigate a variety of burdens associated with antennas while providing added benefits.

  10. Synthesis and Properties of Cross-Linked Polyamide Aerogels

    Science.gov (United States)

    Williams, Jarrod C.; Meador, Mary Ann; McCorkle, Linda

    2015-01-01

    We report the first synthesis of cross-linked polyamide aerogels through step growth polymerization using a combination of diamines, diacid chloride and triacid chloride. Polyamide oligomers endcapped with amines are prepared as stable solutions in N-methylpyrrolidinone from several different diamine precursors and 1,3-benzenedicarbonyl dichloride. Addition of 1,3,5-benzenetricarbonyl trichloride yields gels which form in under five minutes according to the scheme shown. Solvent exchange of the gels into ethanol, followed by drying using supercritical CO2 extraction gives colorless aerogels with densities around 0.1 to 0.2 gcm3. Thicker monolithes of the polyamide aerogels are stiff and strong, while thin films of certain formulations are highly flexible, durable, and even translucent. These materials may have use as insulation for deployable space structures, rovers, habitats or extravehicular activity suits as well as in many terrestrial applications. Strucure property relationships of the aerogels, including surface area, mechanical properties, and thermal conductivity will be discussed.

  11. Thin Aerogel as a Spacer in Multilayer Insulation

    Science.gov (United States)

    Moroz, Nancy

    2015-01-01

    Cryogenic fluid management is a critical technical area that is needed for future space exploration. A key challenge is the storability of liquid hydrogen (LH2), liquid methane (LCH4), and liquid oxygen (LOX) propellants for long-duration missions. The storage tanks must be well-insulated to prevent over-pressurization and venting, which can lead to unacceptable propellant losses for long-duration missions to Mars and beyond. Aspen Aerogels had validated the key process step to enable the fabrication of thin, low-density aerogel materials. The multilayer aerogel insulation (MLAI) system prototypes were prepared using sheets of aerogel materials with superior thermal performance exceeding current state-of-the-art insulation for space applications. The exceptional properties of this system include a new breakthrough in high-vacuum cryogenic thermal insulation, providing a durable material with excellent thermal performance at a reduced cost when compared to longstanding state-of-the-art multilayer insulation systems. During the Phase II project, further refinement and qualification/system-level testing of the MLAI system will be performed for use in cryogenic storage applications. Aspen has been in discussions with United Launch Alliance, LLC; NASA's Kennedy Space Center; and Yetispace, Inc., to test the MLAI system on rea-lworld tanks such as Vibro-Acoustic Test Article (VATA) or the Cryogenic Orbital Testbed (CRYOTE).

  12. Experimental study on occupant evacuation in narrow seat aisle

    Science.gov (United States)

    Huang, Shenshi; Lu, Shouxiang; Lo, Siuming; Li, Changhai; Guo, Yafei

    2018-07-01

    Narrow seat aisle is an important area in the train car interior due to the large passenger population, however evacuation therein has not gained enough concerns. In this experimental study, the occupant evacuation of the narrow seat aisle area is investigated, with the aisle width of 0.4-0.6 m and the evacuation direction of forward and backward. The evacuation behaviors are analyzed based on the video record, and the discussion is carried out in the aspect of evacuation time, crowdedness, evacuation order, and aisle conflicts. The result shows that with the increasing aisle width, total evacuation time and the average specific evacuation rate decrease. The aisle is crowded for some time, with a large linear occupant densities. The evacuation order of each occupant is mainly related to the seat position. Moreover, it is found that the aisle conflicts can be well described by Burstedde's model. This study gives a useful benchmark for evacuation simulation of narrow seat aisle, and provides reference to safety design of seat area in train cars.

  13. Dual effects of guide-based guidance on pedestrian evacuation

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Yi, E-mail: yima23-c@my.cityu.edu.hk; Lee, Eric Wai Ming; Shi, Meng

    2017-06-15

    This study investigates the effects of guide-based guidance on the pedestrian evacuation under limited visibility via the simulations based on an extended social force model. The results show that the effects of guides on the pedestrian evacuation under limited visibility are dual, and related to the neighbor density within the visual field. On the one hand, in many cases, the effects of guides are positive, particularly when the neighbor density within the visual field is moderate; in this case, a few guides can already assist the evacuation effectively and efficiently. However, when the neighbor density within the visual field is particularly small or large, the effects of guides may be adverse and make the evacuation time longer. Our results not only provide a new insight into the effects of guides on the pedestrian evacuation under limited visibility, but also give some practical suggestions as to how to assign guides to assist the evacuation under different evacuation conditions. - Highlights: • Extended social force model is used to simulate guided pedestrian evacuation. • Effects of guides on pedestrian evacuation under limited visibility are dual. • Effects of guides on pedestrian evacuation under limited visibility are related to neighbor density within visual field.

  14. Predictive value of impaired evacuation at proctography in diagnosing anismus.

    Science.gov (United States)

    Halligan, S; Malouf, A; Bartram, C I; Marshall, M; Hollings, N; Kamm, M A

    2001-09-01

    We aimed to determine the positive predictive value of impaired evacuation during evacuation proctography for the subsequent diagnosis of anismus. Thirty-one adults with signs of impaired evacuation (defined as the inability to evacuate two thirds of a 120 mL contrast enema within 30 sec) during evacuation proctography underwent subsequent anorectal physiologic testing for anismus. A physiologic diagnosis of anismus was based on a typical clinical history of the condition combined with impaired rectal balloon expulsion or abnormal surface electromyogram. Twenty-eight (90%) of the 31 patients with impaired proctographic evacuation were found to have anismus at subsequent physiologic testing. Among the 28 were all 10 patients who evacuated no contrast medium and all 11 patients with inadequate pelvic floor descent, giving evacuation proctography a positive predictive value of 90% for the diagnosis of anismus. A prominent puborectal impression was seen in only three subjects during proctography, one of whom subsequently showed no physiologic sign of anismus. Impaired evacuation during evacuation proctography is highly predictive for diagnosis of anismus.

  15. Optimization of Evacuation Warnings Prior to a Hurricane Disaster

    Directory of Open Access Journals (Sweden)

    Dian Sun

    2017-11-01

    Full Text Available The key purpose of this paper is to demonstrate that optimization of evacuation warnings by time period and impacted zone is crucial for efficient evacuation of an area impacted by a hurricane. We assume that people behave in a manner consistent with the warnings they receive. By optimizing the issuance of hurricane evacuation warnings, one can control the number of evacuees at different time intervals to avoid congestion in the process of evacuation. The warning optimization model is applied to a case study of Hurricane Sandy using the study region of Brooklyn. We first develop a model for shelter assignment and then use this outcome to model hurricane evacuation warning optimization, which prescribes an evacuation plan that maximizes the number of evacuees. A significant technical contribution is the development of an iterative greedy heuristic procedure for the nonlinear formulation, which is shown to be optimal for the case of a single evacuation zone with a single evacuee type case, while it does not guarantee optimality for multiple zones under unusual circumstances. A significant applied contribution is the demonstration of an interface of the evacuation warning method with a public transportation scheme to facilitate evacuation of a car-less population. This heuristic we employ can be readily adapted to the case where response rate is a function of evacuation number in prior periods and other variable factors. This element is also explored in the context of our experiment.

  16. On the improvement of mechanical properties of monolithic silica aerogels (for transparent insulating material); Silica aerogel (tomei dannetsu zairyo) kyodo no kaizen ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Tajiri, K; Igarashi, K; Tanemura, S [National Industrial Research Institute of Nagoya, Nagoya (Japan)

    1997-11-25

    Study was made on improvement of the strength of silica aerogel as transparent insulating material. Silica aerogel is a low-density porous material with high heat insulation and transparency. To develop a insulating material with high transparency, monolithic silica aerogel was studied. For direct use of it for windows, its strength improvement was attempted. The aerogel was prepared by supercritical drying (alcohol or CO2) of silica wet gel obtained by hydrolysis and condensation of silicon alkoxide solution. To prepare the aerogel bonded on plate glass for strength improvement, the aerogel was bonded to alkoxide by exposing active silanol radical through F-etching of plate glass surface. However, to obtain the practical large-area bonded aerogel, shrinkage control of the aerogel in supercritical drying was necessary. Addition of Laponite into a silica network for strength improvement by polymer increased the bending strength by 50%. Although some reduction of its transparency was observed because of clouding, its heat insulation was stable. Further strength improvement is necessary for its practical use. 5 figs., 1 tab.

  17. Measurement of the total solar energy transmittance (g-value) for conventional glazings

    DEFF Research Database (Denmark)

    Duer, Karsten

    1998-01-01

    Three different glazings have been investigated in the Danish experimental setup METSET. (A device for calorimetric measurement of total solar energy transmittance - g-value).The purpose of the measurements is to increase the confidence in the calorimetric measurements. This is done by comparison...

  18. Measurement of the total solar energy transmittance (g-value) for complex glazings

    DEFF Research Database (Denmark)

    Duer, Karsten

    1999-01-01

    Four different complex glazings have been investigated in the Danish experimental setup METSET.The purpose of the measurements is to increase the confidence in the calorimetric measurements and to perform measurements and corrections according to a method developed in the ALTSET project...

  19. The use of micro-XRD for the study of glaze color decorations

    Energy Technology Data Exchange (ETDEWEB)

    Pradell, T.; Molina, G. [Universitat Politecnica de Catalunya, Dpt. Fisica i Enginyeria Nuclear, Castelldefels (Spain); Molera, J.; Pla, J. [Universitat de Vic, GRTD, Escola Politecnica Superior, Vic (Spain); Labrador, A. [BM16-ESRF, LLS, BP 220, Grenoble Cedex (France); Lund University, MAX IV Laboratory, Lund (Sweden)

    2013-04-15

    The compounds responsible for the colors and decorations in glass and glazed ceramics include: coloring agents (transition-metal ions), pigments (micro- and nanoprecipitates of compounds that either do not dissolve or recrystallize in the glassy matrix) and opacifiers (microcrystalline compounds with high light scattering capability). Their composition, structure and range of stability are highly dependent not only on the composition but also on the procedures followed to obtain them. Chemical composition of the colorants and crystallites may be obtained by means of SEM-EDX and WDX. Synchrotron radiation micro-X-ray diffraction (SR-micro-XRD) has a small beam size adequate (10 to 50 microns footprint size) to obtain the structural information of crystalline compounds and high brilliance, optimal for determining the crystallites even when present in low amounts. In addition, in glass decorations the crystallites often appear forming thin layers (from 10 to 100 micrometers thick) and they show a depth-dependent composition and crystal structure. Their nature and distribution across the glass/glaze decorations gives direct information on the technology of production and stability and may be related to the color and appearance. A selection of glass and glaze coloring agents and decorations are studied by means of SR-micro-XRD and SEM-EDX including: manganese brown, antimony yellow, red copper lusters and cobalt blue. The selection includes Medieval (Islamic, and Hispano Moresque) and Renaissance tin-glazed ceramics from the 10th to the 17th century AD. (orig.)

  20. New milarite/osumilite-type phase formed during ancient glazing of an Egyptian scarab

    Science.gov (United States)

    Artioli, G.; Angelini, I.; Nestola, F.

    2013-02-01

    A scarab found in grave 25 of the Monte Prama necropolis, near Cabras, Oristano, Sardinia, is of special importance for the archaeological interpretation and dating of this important archaeological site. The object has been misinterpreted in the past as composed by bone: recent archaeometric analyses showed that it is a glazed steatite of Egyptian origin and that the altered surface contains interesting phases crystallized during the high-temperature interaction of the Mg-rich talc core with the alkali-rich glass used for glazing. A novel single crystal X-ray diffraction analysis of one of the phases indicates that it is a new compound having the milarite-osumilite structure type, with a peculiar composition close to (Na1.52K0.12□0.36)(Mg3)(Mg1.72Cu0.16Fe0.12)(Si11.4Al0.6)O30, not reported for naturally occurring minerals. The structural and crystal chemical features of the compound, together with the known high-temperature stability of the series, allow a complete interpretation of the glazing process and conditions, based on direct application of the glaze on the steatite core with subsequent treatment at temperatures above 1000 °C.

  1. The characterisation of the daylighting properties of special glazings and solar shading devices

    NARCIS (Netherlands)

    Dijk, H.A.L. van; Bakker, L.G.

    1998-01-01

    Within the EU DGXII R&D Programme JOULE a project, called REVIS. started in 1998 and will be completed within 2.5 years, with the objective to develop detailed daylight product information of novel products of glazings and solar shading devices. This involves a test procedure, definition of product

  2. Modelling the optical and thermal properties of advanced glazing overview of recent developments

    NARCIS (Netherlands)

    Rosenfeld, J.L.J.; Platzer, W.J.; Dijk, H.A.L. van; Maccari, A.

    2001-01-01

    The recently completed ALTSET project was part of the European Commission's Standards, Measurement and Testing programme. Its objective was the development of European standard test procedures for the determination of angular-dependent light and total solar energy transmittance for complex glazings

  3. Permanent transparent color-warming glazes for dimmable and non-dimmable LED bulbs

    Science.gov (United States)

    Spanard, Jan-Marie A.

    2014-02-01

    Illuminant metameric failure is frequently experienced when viewing material samples under LED generated light vs. traditional incandescent light. LED light temperatures can be improved with phosphor coatings, but long-wave red light is still generally absent in LED "warm-white" light, resulting in metameric failure of orange-to-red objects. Drawing on techniques developed for the architectural restoration of stained glass, we find that transparent, heat-resistant, permanent, pigmented coatings can be applied to any glass, aluminum or plastic surface of an LED bulb, including the phosphor plate, dome or envelope, to produce warmer visible light than in current warm-light LED bulbs. These glazes can be applied in combination with existing technologies to better tune the LED emitted light or they may be used alone. These pigmented coatings include, but are not limited to, those made by suspending inorganic materials in potassium silicates or durable transparent pigmented resins. The pigmented resin glazes may be produced in either a clear gloss vehicle or an iridescent, light diffusing transparent base. Further, a graduated density of the tinted glazes on dimmable bulbs allow the light to change color as wattage is diminished. The glazes may be applied in the manufacturing of the bulb or marketed to current bulb owners as an after-market product to better tune the thousands of LED light bulbs currently in use.

  4. Energy Labelling of Glazings and Windows in Denmark: Calculated and Measured Values

    DEFF Research Database (Denmark)

    Duer, Karsten; Svendsen, Svend; Mogensen, Morten Møller

    2002-01-01

    The influence of windows on the energy consumption in buildings is well known and in order to encourage the development and the appropriate use of high performance glazings and windows in Denmark, an Energy Labelling and Rating system is being developed. During this work a need for establishing...

  5. Oil and the Translucent. Varnishing and glazing in practice, recipes and historiography, 1100-1600

    NARCIS (Netherlands)

    Bol, M.A.H.

    2012-01-01

    This dissertation studies for the first time the history of varnishing and glazing in relation to the use of drying oils in the workshop of the medieval painter until the late sixteenth century. Results from technical research and historical reconstructions will be combined with an analysis of

  6. Wear characteristics of polished and glazed lithium disilicate ceramics opposed to three ceramic materials.

    Science.gov (United States)

    Saiki, Osamu; Koizumi, Hiroyasu; Akazawa, Nobutaka; Kodaira, Akihisa; Okamura, Kentaro; Matsumura, Hideo

    2016-01-01

    This study compared the wear characteristics of a heat-pressed lithium disilicate ceramic material opposed to feldspathic porcelain, a lithium disilicate glass ceramic, and zirconia materials. Ceramic plate specimens were prepared from feldspathic porcelain (EX-3 nA1B), lithium disilicate glass ceramics (e.max CAD MO1/C14), and zirconia (Katana KT 10) and then ground or polished. Rounded rod specimens were fabricated from heat-pressed lithium disilicate glass ceramic (e.max press LT A3) and then glazed or polished. A sliding wear testing apparatus was used for wear testing. Wear of glazed rods was greater than that of polished rods when they were abraded with ground zirconia, ground porcelain, polished porcelain, or polished lithium disilicate ceramics. For both glazed and polished rods, wear was greater when the rods were abraded with ground plates. The findings indicate that application of a polished surface rather than a glazed surface is recommended for single restorations made of heat-pressed lithium disilicate material. In addition, care must be taken when polishing opposing materials, especially those used in occlusal contact areas. (J Oral Sci 58, 117-123, 2016).

  7. Robust superhydrophobic bridged silsesquioxane aerogels with tunable performances and their applications.

    Science.gov (United States)

    Wang, Zhen; Wang, Dong; Qian, Zhenchao; Guo, Jing; Dong, Haixia; Zhao, Ning; Xu, Jian

    2015-01-28

    Aerogels are a family of highly porous materials whose applications are commonly restricted by poor mechanical properties. Herein, thiol-ene chemistry is employed to synthesize a series of novel bridged silsesquioxane (BSQ) precursors with various alkoxy groups. On the basis of the different hydrolyzing rates of the methoxy and ethoxy groups, robust superhydrophobic BSQ aerogels with tailorable morphology and mechanical performances have been prepared. The flexible thioether bridge contributes to the robustness of the as-formed aerogels, and the property can be tuned on the basis of the distinct combinations of alkoxy groups with the density of the aerogels almost unchanged. To the best of our knowledge, the lowest density among the ambient pressure dried aerogels is obtained. Further, potential application of the aerogels for oil/water separation and acoustic materials has also been presented.

  8. Methods for controlling pore morphology in aerogels using electric fields and products thereof

    Science.gov (United States)

    Worsley, Marcus A.; Baumann, Theodore F.; Satcher, Jr., Joe H.; Olson, Tammy Y.; Kuntz, Joshua D.; Rose, Klint A.

    2017-12-16

    In one embodiment, an aerogel or xerogel includes column structures of a material having minor pores therein and major pores devoid of the material positioned between the column structures, where longitudinal axes of the major pores are substantially parallel to one another. In another embodiment, a method includes heating a sol including aerogel or xerogel precursor materials to cause gelation thereof to form an aerogel or xerogel and exposing the heated sol to an electric field, wherein the electric field causes orientation of a microstructure of the sol during gelation, which is retained by the aerogel or xerogel. In one approach, an aerogel has elongated pores extending between a material arranged in column structures having structural characteristics of being formed from a sol exposed to an electric field that causes orientation of a microstructure of the sol during gelation which is retained by the elongated pores of the aerogel.

  9. Spray freeze-dried nanofibrillated cellulose aerogels with thermal superinsulating properties.

    Science.gov (United States)

    Jiménez-Saelices, Clara; Seantier, Bastien; Cathala, Bernard; Grohens, Yves

    2017-02-10

    Nanofibrillated cellulose (NFC) aerogels were prepared by spray freeze-drying (SFD). Their structural, mechanical and thermal insulation properties were compared to those of NFC aerogels prepared by conventional freeze-drying (CFD). The purpose of this investigation is to develop superinsulating bioaerogels by reducing their pore size. Severe reduction of the aerogel pore size and skeleton architecture were observed by SEM, aerogels prepared by SFD method show a fibril skeleton morphology, which defines a mesoporous structure. BET analyses confirm the appearance of a new organization structure with pores of nanometric sizes. As a consequence, the thermal insulation properties were significantly improved for SFD materials compared to CFD aerogel, reaching values of thermal conductivity as low as 0.018W/(mK). Moreover, NFC aerogels have a thermal conductivity below that of air in ambient conditions, making them one of the best cellulose based thermal superinsulating material. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Surface characterization of polymers used in fabrication of interim prostheses after treatment with photopolymerized glaze

    International Nuclear Information System (INIS)

    Santos, Daniela Micheline dos; Commar, Betina Chiarelo; Rocha Bonatto, Liliane da; Freitas da Silva, Emily Vivianne; Sônego, Mariana Vilela; Rangel, Elidiane Cipriano; Pesqueira, Aldieris Alves; Goiato, Marcelo Coelho

    2017-01-01

    The material used for interim prostheses fabrication must present excellent physical properties for greater longevity in the face of environmental conditions, which can occur in the oral cavity. The purpose of this study was to evaluate the effect of a photopolymerized glaze on the physical and mechanical properties of polymers used for the fabrication of interim prostheses, before and after thermocycling and immersion in staining solutions. One hundred samples of composite and acrylic resins were fabricated: Dencor chemically activated acrylic resin (CAAR) (n = 20) and heat-polymerized acrylic resin (HPAR) (n = 20), Charisma (n = 20), Structur (n = 20), and Protemp (n = 20). A mechanical polishing was performed on half of the samples, and a chemical polishing was performed on the remaining samples. Subsequently, all samples were submitted to thermocycling and immersion in coffee staining solution for 21 days. Analysis of color and microhardness, as well as atomic force microscopy (AFM), scanning electron microscopy (SEM), and energy dispersive x-ray spectrometry (EDS) were performed. The data were submitted to repeated-measures analysis of variance (ANOVA), followed by the Tukey test (α = 0.05) and the Student t-test (α = 0.05). It was verified that the glaze decreased the chromatic alteration values, and increased the microhardness values of the samples, with the exception of the Charisma resin. The samples that did not receive chemical polishing had the greatest number of surface irregularities. This study concluded that the groups with glaze presented less color alteration. In addition, Charisma and Structur resins exhibited the greatest chromatic stability. As to the microhardness, the values were greater when the samples were treated with the glaze, with the exception of the Charisma group. - Highlights: • Polymers used in fabrication of interim prostheses were analyzed. • The influence of a chemical polishing on these polymers was analyzed.

  11. Changes to Glazed Dental Ceramic Shade, Roughness, and Microhardness after Bleaching and Simulated Brushing.

    Science.gov (United States)

    Rodrigues, Carlos Roberto Teixeira; Turssi, Cecilia Pedroso; Amaral, Flávia Lucisano Botelho; Basting, Roberta Tarkany; França, Fabiana Mantovani Gomes

    2017-09-05

    To evaluate shade stability, surface roughness, microhardness, and compressive strength of a glazed feldspathic ceramic subjected to bleaching and simulated brushing. Eighty-eight glazed feldspathic ceramic specimens were made from microparticulate leucite and divided into eight groups (n = 10). The whitening products used were: Opalescence Trèswhite Supreme (Ultradent), Opalescence®\\ PF 15% (Ultradent), and Oral-B 3D White Whitestrips. All substances for whitening were used for 4 hours/day for a period of 14 days; the control group was not bleached. Next, half of the specimens were individually brushed. Microhardness and surface roughness data were subjected to three-way ANOVA and Tukey test. The diametrical tensile strength data were subjected to two-way ANOVA. The shade change data were analyzed using Kruskal-Wallis, Mann-Whitney, and the Student-Newman-Keuls test. The significance level was set at 5%. Glazed feldspathic ceramic surface microhardness was significantly affected by bleaching agents (p = 0.007). Initially, glazed ceramic microhardness was significantly higher than that observed after contact with the bleaching agents, whether or not brushing was performed. The specimens submitted to bleaching in preloaded trays presented lower surface roughness values after brushing (p = 0.037). The surface roughness was significantly lower in the brushed specimens (p = 0.044). The diametrical tensile strength was not significantly affected by the application of bleaching agents (p = 0.563) or by brushing (p = 0.477). When the specimens were brushed, however, shade change was significantly influenced by the bleaching agent used (p = 0.041). Bleaching agents associated with brushing cycles can alter surface properties and shade stability of glazed feldspathic ceramics, though such findings may not reflect the performance of unglazed feldspathic ceramics. © 2017 by the American College of Prosthodontists.

  12. Surface characterization of polymers used in fabrication of interim prostheses after treatment with photopolymerized glaze

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Daniela Micheline dos, E-mail: danielamicheline@foa.unesp.br [Department of Dental Materials and Prosthodontics, Aracatuba Dental School, Univ Estadual Paulista (UNESP), José Bonifácio St., 1193, Aracatuba, São Paulo 16015-050 (Brazil); Commar, Betina Chiarelo; Rocha Bonatto, Liliane da; Freitas da Silva, Emily Vivianne; Sônego, Mariana Vilela [Department of Dental Materials and Prosthodontics, Aracatuba Dental School, Univ Estadual Paulista (UNESP), José Bonifácio St., 1193, Aracatuba, São Paulo 16015-050 (Brazil); Rangel, Elidiane Cipriano [Technological Plasma Laboratory (LaPTec), Experimental Campus of Sorocaba, Univ Estadual Paulista (UNESP), Tres de Março Av., 511, Sorocaba, Sao Paulo, 18087-180 (Brazil); Pesqueira, Aldieris Alves; Goiato, Marcelo Coelho [Department of Dental Materials and Prosthodontics, Aracatuba Dental School, Univ Estadual Paulista (UNESP), José Bonifácio St., 1193, Aracatuba, São Paulo 16015-050 (Brazil)

    2017-02-01

    The material used for interim prostheses fabrication must present excellent physical properties for greater longevity in the face of environmental conditions, which can occur in the oral cavity. The purpose of this study was to evaluate the effect of a photopolymerized glaze on the physical and mechanical properties of polymers used for the fabrication of interim prostheses, before and after thermocycling and immersion in staining solutions. One hundred samples of composite and acrylic resins were fabricated: Dencor chemically activated acrylic resin (CAAR) (n = 20) and heat-polymerized acrylic resin (HPAR) (n = 20), Charisma (n = 20), Structur (n = 20), and Protemp (n = 20). A mechanical polishing was performed on half of the samples, and a chemical polishing was performed on the remaining samples. Subsequently, all samples were submitted to thermocycling and immersion in coffee staining solution for 21 days. Analysis of color and microhardness, as well as atomic force microscopy (AFM), scanning electron microscopy (SEM), and energy dispersive x-ray spectrometry (EDS) were performed. The data were submitted to repeated-measures analysis of variance (ANOVA), followed by the Tukey test (α = 0.05) and the Student t-test (α = 0.05). It was verified that the glaze decreased the chromatic alteration values, and increased the microhardness values of the samples, with the exception of the Charisma resin. The samples that did not receive chemical polishing had the greatest number of surface irregularities. This study concluded that the groups with glaze presented less color alteration. In addition, Charisma and Structur resins exhibited the greatest chromatic stability. As to the microhardness, the values were greater when the samples were treated with the glaze, with the exception of the Charisma group. - Highlights: • Polymers used in fabrication of interim prostheses were analyzed. • The influence of a chemical polishing on these polymers was analyzed.

  13. Assessment of total evacuation systems for tall buildings

    CERN Document Server

    Ronchi, Enrico

    2014-01-01

    This SpringerBrief focuses on the use of egress models to assess the optimal strategy for total evacuation in high-rise buildings. It investigates occupant relocation and evacuation strategies involving the exit stairs, elevators, sky bridges and combinations thereof. Chapters review existing information on this topic and describe case study simulations of a multi-component exit strategy. This review provides the architectural design, regulatory and research communities with a thorough understanding of the current and emerging evacuation procedures and possible future options. A model case study simulates seven possible strategies for the total evacuation of two identical twin towers linked with two sky-bridges at different heights. The authors present the layout of the building and the available egress components including both vertical and horizontal egress components, namely stairs, occupant evacuation elevators (OEEs), service elevators, transfer floors and sky-bridges. The evacuation strategies employ a ...

  14. Thermal Failure Analysis of Fiber-Reinforced Silica Aerogels under Liquid Nitrogen Thermal Shock

    Directory of Open Access Journals (Sweden)

    Ai Du

    2018-06-01

    Full Text Available Aerogel materials are recognized as promising candidates for the thermal insulator and have achieved great successes for the aerospace applications. However, the harsh environment on the exoplanet, especially for the tremendous temperature difference, tends to affect the tenuous skeleton and performances of the aerogels. In this paper, an evaluation method was proposed to simulate the environment of exoplanet and study the influence on the fiber-reinforced silica aerogels with different supercritical point drying (SPD technology. Thermal conductivity, mechanical property and the microstructure were characterized for understanding the thermal failure mechanism. It was found that structure and thermal property were significantly influenced by the adsorbed water in the aerogels under the thermal shocks. The thermal conductivity of CO2-SPD aerogel increased 35.5% after the first shock and kept in a high value, while that of the ethanol-SPD aerogel increased only 19.5% and kept in a relatively low value. Pore size distribution results showed that after the first shock the peak pore size of the CO2-SPD aerogel increased from 18 nm to 25 nm due to the shrinkage of the skeleton, while the peak pore size of the ethanol-SPD aerogel kept at ~9 nm probably induced by the spring-back effect. An 80 °C treatment under vacuum was demonstrated to be an effective way for retaining the good performance of ethanol-SPD aerogels under the thermal shock. The thermal conductivity increases of the ethanol-SPD aerogels after 5 shocks decreased from ~30 to ~0% via vacuum drying, while the increase of the CO2-SPD aerogels via the same treatments remains ~28%. The high-strain hardening and low-strain soften behaviors further demonstrated the skeleton shrinkage of the CO2-SPD aerogel.

  15. Bulkhead Door – Critical Evacuation States

    Directory of Open Access Journals (Sweden)

    Flizikowski Józef

    2017-03-01

    Full Text Available The article is a preliminary to a modification concept of the sliding watertight bulkhead door used on ships and vessels. Hydraulic or electro-hydraulic drives used to move these doors require complicated and extended pressure installations with large amounts of hydraulic fluid. Well-known operational drawbacks of these installations include high level of noise and possibility of various leaks in the hydraulic system. Being the first in a series, the present article describes and analyses critical states which can take place during evacuation of people through openings in the watertight bulkhead doors on seagoing ships and vessels.

  16. SINTESIS SILIKA AEROGEL DENGAN BAHAN DASAR ABU BAGASSE

    Directory of Open Access Journals (Sweden)

    Nazriati Nazriati

    2012-05-01

    Full Text Available SYNTHESIS OF SILICA AEROGEL FROM BAGASSE ASH. Synthesis of silica aerogel from bagasse ash was done by alkaline extraction followed by sol-gel. Bagasse ash was extracted with NaOH at its boiling temperature for one hour with continue stirring, to produce sodium silicate. Subsequently, sodium silicate was pass through ionic exchanger resin, to produces silicic acid (SA. Silicic acid solution was then added with TMCS and HMDS as surface modifier agent. In order to form gel pH must be adjusted to final pH of 8-9 by addition of NH4OH solution. The resulting gel then was aged and dried at ambient pressure and at a certain time and temperature. Characterization of products was done by measuring its pore volume, surface area, and hydrophobisity (contact angle. TMCS serves as water expeller from the pores and subsequently surface was modified by HMDS and TMCS. HMDS content will linearly increase surface area, pore volume, and the contact angle of the resulting silica aerogel. Characteristics of silica aerogel was generated by varying the composition of the SA:TMCS:HMDS resulting has a surface area of 50-488 m2/g, pore volume from 0.2 to 0.9 m3 /g, the contact angle of 48-119 and pore diameter ranging from 5.7-22.56 nm. Based on the resulting pore diameter, the synthesized of silica aerogel categorized as mesoporous.      Abstrak   Sintesis silika aerogel dari bahan dasar abu bagasse dilakukan dengan ekstraksi basa dan diikuti dengan sol-gel. Abu bagasse diekstrak dengan NaOH pada suhu didihnya sambil diaduk selama satu jam, menghasilkan sodium silikat. Selanjutnya, sodium silikat dilewatkan resin penukar ion, menghasilkan asam silicic (SA. Larutan asam silicic kemudian ditambahkan trimethy­l­chlorosilane (TMCS dan hexamethyldisilazane (HMDS sebagai agen pemodifikasi permukaan. Untuk terjadinya gel pH diatur hingga mencapai 8-9 dengan penambahan larutan NH4OH. Gel yang dihasilkan kemudian di-aging dan dikeringkan pada tekanan ambien pada suhu dan

  17. Magnetic and Mössbauer spectroscopy studies of nanocrystalline iron oxide aerogels

    DEFF Research Database (Denmark)

    Carpenter, E.E.; Long, J.W.; Rolison, D.R.

    2006-01-01

    A sol-gel synthesis was used to produce iron oxide aerogels. These nanocrystalline aerogels have a pore-solid structure similar to silica aerogels but are composed entirely of iron oxides. Mössbauer experiments and x-ray diffraction showed that the as-prepared aerogel is an amorphous or poorly...... crystalline iron oxide, which crystallized as a partially oxidized magnetite during heating in argon. After further heat treatment in air, the nanocrystallites are fully converted to maghemite. The particles are superparamagnetic at high temperatures, but the magnetic properties are strongly influenced...

  18. Structural properties and adsorption capacity of holocellulose aerogels synthesized from an alkali hydroxide-urea solution

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Gu-Joong; Kim, Dae-Young; Hwang, Jae-Hyun; Kang, Joo-Hyon [Dongguk University, Seoul (Korea, Republic of)

    2014-05-15

    A tulip tree was used to synthesize a holocellulose aerogel from an aqueous alkali hydroxide-urea solution with the substitution of an organic solvent followed by freeze-drying. For comparison, the synthesized holocellulose aerogels were divided into two groups according to the source of the hydrogel, an upper suspended layer and a bottom concentrated layer of the centrifuged solution of cellulose and NaOH/urea solvents. We investigated the effects of the temperature of the pre-cooled NaOH/urea solution (i.e., dissolution temperature) on the pore structure and the adsorption capacity of the holocellulose aerogel. A nano-fibrillar network structure of the holocellulose aerogel was observed, with little morphological difference in pore structure for different dissolution temperatures. Both micropores and mesopores were observed in the holocellulose aerogel. The specific surface area of the holocellulose aerogel was generally greater at lower dissolution temperatures. In a series of adsorption tests using methylene blue, the holocellulose aerogel showed the greatest adsorption capacity at the lowest dissolution temperature tested ( -2 .deg. C). However, the dissolution temperature generally had little effect on the adsorption capacity. The holocellulose aerogel produced from the upper suspended layer of the centrifuged hydrogel solution showed a greater porosity and adsorption capacity than the one produced from the bottom concentrated layer. Overall, the aerogel made by utilizing a delignified tulip tree display a high surface area and a high adsorption property, indicating its possible application in eco-friendly adsorption materials.

  19. Structural properties and adsorption capacity of holocellulose aerogels synthesized from an alkali hydroxide-urea solution

    International Nuclear Information System (INIS)

    Kwon, Gu-Joong; Kim, Dae-Young; Hwang, Jae-Hyun; Kang, Joo-Hyon

    2014-01-01

    A tulip tree was used to synthesize a holocellulose aerogel from an aqueous alkali hydroxide-urea solution with the substitution of an organic solvent followed by freeze-drying. For comparison, the synthesized holocellulose aerogels were divided into two groups according to the source of the hydrogel, an upper suspended layer and a bottom concentrated layer of the centrifuged solution of cellulose and NaOH/urea solvents. We investigated the effects of the temperature of the pre-cooled NaOH/urea solution (i.e., dissolution temperature) on the pore structure and the adsorption capacity of the holocellulose aerogel. A nano-fibrillar network structure of the holocellulose aerogel was observed, with little morphological difference in pore structure for different dissolution temperatures. Both micropores and mesopores were observed in the holocellulose aerogel. The specific surface area of the holocellulose aerogel was generally greater at lower dissolution temperatures. In a series of adsorption tests using methylene blue, the holocellulose aerogel showed the greatest adsorption capacity at the lowest dissolution temperature tested ( -2 .deg. C). However, the dissolution temperature generally had little effect on the adsorption capacity. The holocellulose aerogel produced from the upper suspended layer of the centrifuged hydrogel solution showed a greater porosity and adsorption capacity than the one produced from the bottom concentrated layer. Overall, the aerogel made by utilizing a delignified tulip tree display a high surface area and a high adsorption property, indicating its possible application in eco-friendly adsorption materials.

  20. APPROXIMATION OF THE TIME TO INITIATE THE EVACUATION

    Directory of Open Access Journals (Sweden)

    Jiří POKORNÝ

    2016-06-01

    Full Text Available One of the basic prerequisites for securing the safety of people at large group events is to ensure their evacuation in case of emergencies. This article deals with the approximations of time to initiate the evacuation of persons in case of a fire at large group events organized in outdoor spaces. The solution is based on the principles of determining the period to initiate the evacuation of persons in terms of international ISO standards. Considering the specificities of the given outdoor space and possible related security measures, the article recommends the relevant sufficient amount of time to initiate an evacuation.

  1. Evacuation routes performances and fire safety of buildings

    Directory of Open Access Journals (Sweden)

    Laban Mirjana Đ.

    2015-01-01

    Full Text Available Residential buildings, public and business facilities with large number of occupants are particularly exposed to the risk of event with catastrophic consequences, especially in case of fire. Evacuation routes must be separated fire compartments with surfaces made of non-combustible materials. Safe evacuation of building occupants in case of fire is a crucial requirement for the preservation of human life in building. In our engineering practice, calculation model is usually applied in order to determine the time required for evacuation (SRPS TP 21. However, evacuation simulation models are more present in research papers, contributing to better assessment of flow of evacuation in the real time. These models could provide an efficient way of testing the safety of a building in the face of fire and indicate critical points at the evacuation paths. Computer models enable the development and analysis of multiple various scenarios during a fire event, contributing to defining the measures for improving the safety of the building in case of fire. This paper analyses the fulfilment of technical requirements for the safe evacuation and proposes improvement measures based on a comparative analysis of the time required for occupants' evacuation from the building (Department of Civil Engineering and Geodesy in Novi Sad, obtained by calculation model and by using evacuation simulation software.

  2. Study on rapid evacuation in high-rise buildings

    Directory of Open Access Journals (Sweden)

    Xin Zhang

    2017-06-01

    Full Text Available More and more high rising buildings emerged in modern cities, but emergency evacuation of tall buildings has been a worldwide difficult problem. In this paper, a new evacuation device for high rising buildings in fire accident was proposed and studied. This device mainly consisted of special spiral slideway and shunt valve. People in this device could fast slide down to the first floor under gravity without any electric power and physical strength, which is suitable for various emergency evacuation including mobility-impaired persons. The plane simulation test has shown that human being in alternative clockwise and counterclockwise movement will not become dizzy. The evacuated people should wear protection pad, which can prevent slider from being injured by surface friction with the slide, and eliminate the friction coefficient difference caused by different clothes and slide surface. The calculation results show that the evacuation speed of the new device is much faster than traditional staircases. Moreover, such new evacuation device can also be used as a means of vertical transportation in high-rise buildings partly. People can take it from any floor to ground floor directly, which not only save time for waiting for the lifts but also save the power. The new evacuation system is of simple structure, easy to use, and suitable for evacuation and partly used as vertical downwards traffic, which shows light on solving world-wide difficulties on fast evacuation in high-rise buildings.

  3. A Simulation Tool for Hurricane Evacuation Planning

    Directory of Open Access Journals (Sweden)

    Daniel J. Fonseca

    2009-01-01

    Full Text Available Atlantic hurricanes and severe tropical storms are a serious threat for the communities in the Gulf of Mexico region. Such storms are violent and destructive. In response to these dangers, coastal evacuation may be ordered. This paper describes the development of a simulation model to analyze the movement of vehicles through I-65, a major US Interstate highway that runs north off the coastal City of Mobile, Alabama, towards the State of Tennessee, during a massive evacuation originated by a disastrous event such a hurricane. The constructed simulation platform consists of a primary and two secondary models. The primary model is based on the entry of vehicles from the 20 on-ramps to I-65. The two secondary models assist the primary model with related traffic events such as car breakdowns and accidents, traffic control measures, interarrival signaling, and unforeseen emergency incidents, among others. Statistical testing was performed on the data generated by the simulation model to indentify variation in relevant traffic variables affecting the timely flow of vehicles travelling north. The performed statistical analysis focused on the closing of alternative on-ramps throughout the Interstate.

  4. Pedestrian Dynamics Feedback Control of Crowd Evacuation

    CERN Document Server

    Kachroo, Pushkin P.E; Al-nasur, Sadeq J; Shende, Apoorva

    2008-01-01

    Effective evacuation of people from closed spaces is an extremely important topic, since it can save real lives in emergency situations that can be brought about by natural and human made disasters. Usually there are static maps posted at various places at buildings that illustrate routes that should be taken during emergencies. However, when disasters happen, some of these routes might not be valid because of structural problems due to the disaster itself and more importantly because of the distribution of congestion of people spread over the area. The average flow of traffic depends on the traffic density. Therefore, if all the people follow the same route, or follow a route without knowing the congestion situation, they can end up being part of the congestion which results in very low flow rate or worse a traffic jam. Hence it becomes extremely important to design evacuations that inform people how fast and in which direction to move based on real-time information obtained about the people distribution usi...

  5. Optimal nonimaging integrated evacuated solar collector

    Science.gov (United States)

    Garrison, John D.; Duff, W. S.; O'Gallagher, Joseph J.; Winston, Roland

    1993-11-01

    A non imaging integrated evacuated solar collector for solar thermal energy collection is discussed which has the lower portion of the tubular glass vacuum enveloped shaped and inside surface mirrored to optimally concentrate sunlight onto an absorber tube in the vacuum. This design uses vacuum to eliminate heat loss from the absorber surface by conduction and convection of air, soda lime glass for the vacuum envelope material to lower cost, optimal non imaging concentration integrated with the glass vacuum envelope to lower cost and improve solar energy collection, and a selective absorber for the absorbing surface which has high absorptance and low emittance to lower heat loss by radiation and improve energy collection efficiency. This leads to a very low heat loss collector with high optical collection efficiency, which can operate at temperatures up to the order of 250 degree(s)C with good efficiency while being lower in cost than current evacuated solar collectors. Cost estimates are presented which indicate a cost for this solar collector system which can be competitive with the cost of fossil fuel heat energy sources when the collector system is produced in sufficient volume. Non imaging concentration, which reduces cost while improving performance, and which allows efficient solar energy collection without tracking the sun, is a key element in this solar collector design.

  6. Evacuate or Shelter-in-place? The Role of Corporate Memory and Political Environment in Hospital-evacuation Decision Making.

    Science.gov (United States)

    Ricci, Karen A; Griffin, Anne R; Heslin, Kevin C; Kranke, Derrick; Dobalian, Aram

    2015-06-01

    Hospital-evacuation decisions are rarely straightforward in protracted advance-warning events. Previous work provides little insight into the decision-making process around evacuation. This study was conducted to identify factors that most heavily influenced the decisions to evacuate the US Department of Veterans Affairs (VA) New York Harbor Healthcare System's (NYHHS; New York USA) Manhattan Campus before Hurricane Irene in 2011 and before Superstorm Sandy in 2012. Semi-structured interviews with 11 senior leaders were conducted on the processes and factors that influenced the evacuation decisions prior to each event. The most influential factor in the decision to evacuate the Manhattan Campus before Hurricane Irene was New York City's (NYC's) hospital-evacuation mandate. As a federal facility, the Manhattan VA medical center (VAMC) was exempt from the city's order, but decision makers felt compelled to comply. In the case of Superstorm Sandy, corporate memory of a similar 1992 storm that crippled the Manhattan facility drove the decision to evacuate before the storm hit. Results suggest that hospital-evacuation decisions are confounded by political considerations and are influenced by past disaster experience. Greater shared situational awareness among at-risk hospitals, along with a more coordinated approach to evacuation decision making, could reduce pressure on hospitals to make these high-stakes decisions. Systematic mechanisms for collecting, documenting, and sharing lessons learned from past disasters are sorely needed at the institutional, local, and national levels.

  7. Development of Simplified and Dynamic Model for Double Glazing Unit Validated with Full-Scale Facade Element

    DEFF Research Database (Denmark)

    Liu, Mingzhe; Wittchen, Kim Bjarne; Heiselberg, Per

    2012-01-01

    The project aims at developing simplified calculation methods for the different features that influence energy demand and indoor environment behind “intelligent” glazed façades. This paper describes how to set up simplified model to calculate the thermal and solar properties (U and g value......) together with comfort performance (internal surface temperature of the glazing) of a double glazing unit. Double glazing unit is defined as 1D model with nodes representing different layers of material. Several models with different number of nodes and position of these are compared and verified in order...... to find a simplified method which can calculate the performance as accurately as possible. The calculated performance in terms of internal surface temperature is verified with experimental data collected in a full-scale façade element test facility at Aalborg University (DK). The advantage...

  8. Solar assisted biogas plants: Pt. 4. Optimum area for blackening and double glazing over a fixed-dome biogas plant

    Energy Technology Data Exchange (ETDEWEB)

    Jayashankar, B.C.; Kishor, J.; Goyal, I.C.; Sawhney, R.L.; Sodha, M.S.

    The economic analysis of a fixed-dome biogas plant of rated capacity 8 m/sup 3/, above which a part of the ground is blackened and doubly glazed in the cold climate of Srinagar is presented. Blackening and glazing of the ground cannot alone maintain the slurry temperature at 35/sup 0/C, which is the optimum temperature in the mesophilic range for the anaerobic digestion of cattle dung, and so a part of the biogas must be burnt. The electrical simulation experiments have been performed to determine the loss or gain of heat from the underground biodigestor to the ambient atmosphere through the ground if a part of the ground above is blackened and double glazed. Economic analysis of the system shows that the optimum area to be blackened and glazed would have a radius 1.5 times that of the biodigestor.

  9. Low dielectric constant and moisture-resistant polyimide aerogels containing trifluoromethyl pendent groups

    Science.gov (United States)

    Wu, Tingting; Dong, Jie; Gan, Feng; Fang, Yuting; Zhao, Xin; Zhang, Qinghua

    2018-05-01

    Conventional polyimide aerogels made from biphenyl-3,3‧,4,4‧-tetracarboxylic dianydride (BPDA) and 4,4‧-oxidianiline (ODA) exhibit poor resistance to moisture and mechanical properties. In this work, a versatile diamine, 2,2‧-bis-(trifluoromethyl)-4,4‧-diaminobiphenyl (TFMB), is introduced to BPDA/ODA backbone to modify the comprehensive performance of this aerogel. Among all formulations, the resulted polyimide aerogels exhibit the lowest shrinkage and density as well as highest porosity, at the ODA/TFMB molar ratio of 5/5. Dielectric constants and loss tangents of the aerogels fall in the range of 1.29-1.33 and 0.001-0.004, respectively, and more TFMB fractions results in a slightly decrease of dielectric constant and loss tangent. In addition, moisture-resistance of the aerogels are dramatically enhanced as the water absorption decreasing from 415% for BPDA/ODA to 13% for the polyimide aerogel at the ODA/TFMB molar ratio of 7/3, and even to 4% for the homo-BPDA/TFMB polyimide aerogel, showing a superhydrophobic characteristic, which is a great advantage for polyimide aerogels used as low dielectric materials. Meanwhile, all of formulations of aerogels exhibit high absorption capacities for oils and common organic solvents, indicating that these fluorinated polyimide aerogels are good candidates for the separation of oils/organic solvents and water. Mechanical properties and thermal stability of the polyimide aerogels are also raised to varying degrees due to the rigid-rod biphenyl structure introduced by TFMB.

  10. Strong-coupling effects in superfluid 3He in aerogel

    International Nuclear Information System (INIS)

    Aoyama, Kazushi; Ikeda, Ryusuke

    2007-01-01

    Effects of impurity scatterings on the strong-coupling (SC) contribution, stabilizing the ABM (axial) pairing state, to the quartic term of the Ginzburg-Landau free energy of superfluid 3 He are theoretically studied to examine recent observations suggestive of an anomalously small SC effect in superfluid 3 He in aerogels. To study the SC corrections, two approaches are used. One is based on a perturbation in the short-range repulsive interaction, and the other is a phenomenological approach used previously for the bulk liquid by Sauls and Serene [Phys. Rev. B 24, 183 (1981)]. It is found that the impurity scattering favors the BW pairing state and shrinks the region of the ABM pairing state in the T-P phase diagram. In the phenomenological approach, the resulting shrinkage of the ABM region is especially substantial and, if assuming an anisotropy over a large scale in aerogel, leads to justifying the phase diagrams determined experimentally

  11. Elimination of the dirty crust of white alterated glaze from excavated ceramics using the laser cleaning alternative

    OpenAIRE

    Aura Castro, Elvira; Saiz Mauleón, María Begoña; Domenech Carbo, Mª Teresa

    2006-01-01

    The laser technique has been applied to the cleaning process of glazed decorated ceramics from excavation sites. The use of this method arises as the only possible alternative in the process of cleaning pieces with crusts of dirt that are extremely hard and strongly stuck over altered and friable white glaze layers. The study carried out has allowed to fix the optimal laser parameters in the elimination of the dark dirty layer found on several fragments from different periods. The study has b...

  12. Childhood Blood Lead Reductions Following Removal of Leaded Ceramic Glazes in Artisanal Pottery Production: A Success Story

    OpenAIRE

    Donald E. Jones, MS; Mario Covarrubias Pérez; Bret Ericson; Daniel Estrada Sánchez; Sandra Gualtero; Andrea Smith-Jones, MS; Jack Caravanos, DrPH, CIH

    2013-01-01

    Background. Lead exposure within artisanal ceramics workshop communities in Mexico continues to be a major source of childhood lead poisoning. Artisanal ceramics workshops expose children through direct ingestion, contaminated soil, and food prepared in lead-glazed pottery. Conversion to non-lead glazes alone may not effectively reduce exposure. This paper describes a model comprehensive intervention and environmental remediation of an artisanal ceramics workshop in the state of Hidalgo, Mexi...

  13. Intrarectal pressures and balloon expulsion related to evacuation proctography.

    Science.gov (United States)

    Halligan, S; Thomas, J; Bartram, C

    1995-01-01

    Seventy four patients with constipation were examined by standard evacuation proctography and then attempted to expel a small, non-deformable rectal balloon, connected to a pressure transducer to measure intrarectal pressure. Simultaneous imaging related the intrarectal position of the balloon to rectal deformity. Inability to expel the balloon was associated proctographically with prolonged evacuation, incomplete evacuation, reduced anal canal diameter, and acute anorectal angulation during evacuation. The presence and size of rectocoele or intussusception was unrelated to voiding of paste or balloon. An independent linear combination of pelvic floor descent and evacuation time on proctography correctly predicted maximum intrarectal pressure in 74% of cases. No patient with both prolonged evacuation and reduced pelvic floor descent on proctography could void the balloon, as maximum intrarectal pressure was reduced in this group. A prolonged evacuation time on proctography, in combination with reduced pelvic floor descent, suggests defecatory disorder may be caused by inability to raise intrarectal pressure. A diagnosis of anismus should not be made on proctography solely on the basis of incomplete/prolonged evacuation, as this may simply reflect inadequate straining. PMID:7672656

  14. Clarifying evacuation options through fire behavior and traffic modeling

    Science.gov (United States)

    Carol L. Rice; Ronny J. Coleman; Mike. Price

    2011-01-01

    Communities are becoming increasingly concerned with the variety of choices related to wildfire evacuation. We used ArcView with Network Analyst to evaluate the different options for evacuations during wildfire in a case study community. We tested overlaying fire growth patterns with the road network and population characteristics to determine recommendations for...

  15. 14 CFR 121.570 - Airplane evacuation capability.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airplane evacuation capability. 121.570... REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Flight Operations § 121.570 Airplane evacuation capability. (a) No person may cause an airplane carrying passengers to be moved on the surface, take off, or...

  16. Theoretical and experimental investigation of REB interaction with aerogel targets

    Energy Technology Data Exchange (ETDEWEB)

    Efremov, V P; Fortov, V E [Russian Academy of scinces, Moscow (Russian Federation). High Energy Density Research Center; Demidov, B A; Ivonin, I A [Kurchatov Institute, Moscow (Russian Federation); Vorobev, O Yu [Institute of Chemical Physics, Chernogolovka (Russian Federation); Keeler, N

    1997-12-31

    Recent results of luminosity measurements of aerogel targets (with a density about 0.36 g/cc) irradiated with `KALMAR` beam are reported. The beam current was varied within the range of 10-20 kA, the pulse duration was 80-120 ns and the electron energy was from 200 keV to 290 keV. Absorbed energy distribution in the deposition zone was compared with the results of calculations. (author). 4 figs., 4 refs.

  17. Novel retrofit technologies incorporating silica aerogel for lower energy buildings

    OpenAIRE

    Dowson, Mark

    2012-01-01

    This thesis was submitted for the degree of Doctor of Engineering and was awarded by Brunel University. The aim of this Engineering Doctorate is to design, build and test novel environmental retrofit technologies to reduce energy consumption in existing buildings. Three contributions to knowledge are documented. The first contribution is the technical verification of a novel proof-of-principle prototype incorporating translucent silica aerogel granules to improve the thermal performance of...

  18. Computer simulation-based framework for transportation evacuation in major trip generator.

    Science.gov (United States)

    2009-01-01

    Since emergencies including both natural disasters and man-made incidents, are happening more and more : frequently, evacuation, especially transportation evacuation, is becoming a hot research focus in recent years. : Currently, transportation evacu...

  19. Selectively coated high efficiency glazing for solar-thermal flat-plate collectors

    International Nuclear Information System (INIS)

    Ehrmann, N.; Reineke-Koch, R.

    2012-01-01

    In order to increase the efficiency of solar-thermal flat-plate collectors at temperatures above 100 °C or with low solar irradiation, we implement a double glazing with a low-emitting (low-e) coating on the inner pane to improve the insulation of the transparent cover. Since commercially available low-e glazing provides only insufficient solar transmittance for the application in thermal flat-plate collectors we are developing a sputter-deposited low e-coating system based on transparent conductive oxides which provides a high solar transmittance of 85% due to additional antireflective coatings and the use of low-iron glass substrates. Durability tests of the developed coating system show that our low e-coating system is well suitable even at high temperatures, humidity and condensation.

  20. Measurement of natural radioactivity in commercial granites and glazing stones from Aswan area, Egypt

    International Nuclear Information System (INIS)

    Ahmad, F.; Shousha, H.A.

    2005-01-01

    Ornamental stones are considered as an important source of the mineral wealth in Egypt. These rocks have characteristics that enable them to be used in decoration as being hard, able to be polished and have low water absorption. A knowledge of radioactivity present in these natural rock samples helps to assess the possible radiological hazards to human health and hence take safety precautions if necessary. For the first time, the natural radioactivity of glazing stones used in granite possessing was measured. The concentration of natural radionuclides U-238, Th-232 and K-40 for eighteen ore and three processed granite samples from Aswan area have been determined using a shielded high purity germanium detector coupled to a computerized multichannel analyzer. Also, the gamma activities of 13 glazing stones, which are used in processing of granite, were measured. The average values of the measured activities for granite were 66.15 ± 4.48, 86.12 ± 5.43 and 1902.03 ± 50.64 Bq/kg and for glazing stones were 44.05 ± 3.54, 51.58 ± 4.44 and 87.55 ± 5.46 Bq/kg for U-238, Th-232 and K-40, respectively. The main absorbed dose rates were 167.04 ± 7.52 and 56.72 ± 7.00 n Gy/h at one meter above the ground level for granite and glazing stones, respectively. The average estimated radium equivalent was 335.75 ± 16.48 and 124.55 ± 11.36 Bq/kg for granite and glazing stones, respectively. This value is comparable with the reported values for many countries (370 Bq/kg). The external hazard index varied from 0.5 ± 0.02 to 1.79 ± 0.09 mGy/y for granite and from 0.042 ± 0.011 to 0.852 ± 0.080 mGy/y for glazing stones. Cs-137 concentration ranged from 0.15 ± 0.07 to 3.31 ± 0.29 Bq/kg for granite and from 0.29 ± 0.02 to 1.49 ± 0.010 Bq/kg for glazing stones. For glazing stones, the measured samples are acceptable for use and safe to the workers in granite processing. The radon exhalation rate for granite samples was calculated using nuclear track detector (CR-39). It was

  1. Partial Rarefaction as Way to Reduce Distortion Curve of double-glazed unit

    Science.gov (United States)

    Plotnikov, Alexander

    2017-10-01

    Use of Insulated Glass Units (IGU) as glazing on building façades causes optical distortions of mirrored images of neighboring buildings in glazed surfaces. Optical distortions are caused by varying distances between glass panes in IGUs as a result of climate factors. This paper examines available engineering solutions that reduce such distortions: use of more rigid outer glasses, encasing the building in a shell of single glass panes, known as the ‘double façade’, and use of vacuum IGUs. A new way is proposed to reduce optical distortions by installing additional pointed or linear supports and creating pre-stress with partial rarefaction inside the IGU. Overpressure that can cause IGU expansion and glass deformation was calculated. In the urban environment of Moscow, reduction of air pressure with simultaneous increase of air pressure inside the IGU during summer heat waves can be as high as 5%, and this figure determines the level of rarefaction.

  2. [Environmental lead poisoning from lead-glazed earthenware used for storing drinks].

    Science.gov (United States)

    Sabouraud, S; Coppéré, B; Rousseau, C; Testud, F; Pulce, C; Tholly, F; Blanc, M; Culoma, F; Facchin, A; Ninet, J; Chambon, P; Medina, B; Descotes, J

    2009-12-01

    Current unusual environmental sources of lead exposure mainly include traditional medicines, either ayurvedic remedies or others, traditional cosmetics (kohl, surma), and the use of traditional earthenware, for storage or cooking. We report two cases of lead poisoning in adults initially identified by paroxysmal abdominal pain or anemia. In both cases, the environmental investigation evidenced one main source of lead exposure, namely a lead-glazed earthenware jug in which a drink was stored, "kefir" in the first case, and "kombucha" tea in the second one. It is recommended to search for lead intoxication in patients with unexplained anemia. Environmental sources of lead can be multiple. Their relative importance has to be ranked during the environmental investigation and among these, lead-glazed earthenware must be considered as a source of high lead exposure when drinks are stored inside and thus can soak.

  3. Particle detection and identification through Cerenkov effect in silica aerogels

    International Nuclear Information System (INIS)

    Engelmann, J.J.; Cantin, M.

    1978-01-01

    Cerenkov counters are largely used in high energy physics and in nuclear astrophysics to identify the charge of high energy particles and to measure their velocity. Good velocity resolution is obtained only near the Cerenkov threshold, which is directly dependent on the refractive index of the radiator. It is therefore very important to dispose of materials of various refractive indices. The silica aerogel allows to cover a range of indices between 1.015 and 1.2 which is intermediate between the indices given by gas and liquids. The samples most often built until now are hexagonal blocks of 1.06 refractive index and 0.24 g/cm 3 density. Blocks of one liter in volume have been assembled to form a mosaic of large dimension. For lower refractive indices, 1.015 for instance, the material becomes too brittle. So we have been led to use an aerogel sand made of aerogel grains of controlled granulometry. Radiators of both types blocks and sand are used in the franco-danish experiment to be launched aboard the NASA satellite HEAO-C in July 1979 [fr

  4. Wet-Spun Superelastic Graphene Aerogel Millispheres with Group Effect.

    Science.gov (United States)

    Zhao, Xiaoli; Yao, Weiquan; Gao, Weiwei; Chen, Hao; Gao, Chao

    2017-09-01

    Graphene aerogel has attracted great attention due to its unique properties, such as ultralow density, superelasticity, and high specific surface area. It shows huge potential in energy devices, high-performance pressure sensors, contaminates adsorbents, and electromagnetic wave absorbing materials. However, there still remain some challenges to further promote the development and real application of graphene aerogel including cost-effective scalable fabrication and miniaturization with group effect. This study shows millimeter-scale superelastic graphene aerogel spheres (GSs) with group effect and multifunctionality. The GSs are continuously fabricated on a large scale by wet spinning of graphene oxide liquid crystals followed by facile drying and thermal annealing. Such GS has an unusual core-shell structure with excellent elasticity and specific strength. Significantly, both horizontally and vertically grouped spheres exhibit superelasticity comparable to individual spheres, enabling it to fully recover at 95% strain, and even after 1000 compressive cycles at 70% strain, paving the way to wide applications such as pressure-elastic and adsorbing materials. The GS shows a press-fly behavior with an extremely high jump velocity up to 1.2 m s -1 . For the first time, both free and oil-adsorbed GSs are remotely manipulated on water by electrostatic charge due to their ultralow density and hydrophobic properties. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Aerogel RICH for the Belle II forward PID

    Energy Technology Data Exchange (ETDEWEB)

    Nishida, S., E-mail: shohei.nishida@kek.jp [High Energy Accelerator Research Organization (KEK), Tsukuba (Japan); Adachi, I. [High Energy Accelerator Research Organization (KEK), Tsukuba (Japan); Hamada, N. [Toho University, Funabashi (Japan); Hara, K. [High Energy Accelerator Research Organization (KEK), Tsukuba (Japan); Iijima, T. [Nagoya University, Nagoya (Japan); Iwata, S.; Kakuno, H. [Tokyo Metropolitan University, Hachioji (Japan); Kawai, H. [Chiba University, Chiba (Japan); Korpar, S.; Krizan, P. [Jozef Stefan Institute, Ljubljana (Slovenia); Ogawa, S. [Toho University, Funabashi (Japan); Pestotnik, R.; Ŝantelj, L.; Seljak, A. [Jozef Stefan Institute, Ljubljana (Slovenia); Sumiyoshi, T. [Tokyo Metropolitan University, Hachioji (Japan); Tabata, M. [Japan Aerospace Exploration Agency (JAXA), Sagamihara (Japan); Tahirovic, E. [Jozef Stefan Institute, Ljubljana (Slovenia); Yoshida, K. [Tokyo Metropolitan University, Hachioji (Japan); Yusa, Y. [Niigata University, Niigata (Japan)

    2014-12-01

    The Belle II spectrometer, a follow up of the very successful Belle experiment, is under construction at the SuperKEKB electron–positron collider at KEK in Japan. For the PID system in the forward region of the spectrometer, a proximity focusing ring-imaging Cherenkov (RICH) counter with an aerogel radiator is being developed. The counter will provide a 4σ separation of pions and kaons up to momenta of 4 GeV/c. For the position sensitive photon sensor, a 144-channel Hybrid Avalanche Photo-Detector (HAPD) has been developed with Hamamatsu Photonics K.K. The readout electronics is based on the custom developed ASIC. The design of the components is currently being finalized and part of their mass production have already started. Herein, we report the final design of the counter and a prototype test conducted with test beams at DESY. - Highlights: • We are constructing a RICH counter with aerogel radiator for Belle II. • Beam test for the prototype Aerogel RICH shows its good performance. • The effect of the neutron irradiation of the photodetector is examined.

  6. Evacuation proctography - examination technique and method of evaluation

    International Nuclear Information System (INIS)

    Braunschweig, R.; Schott, U.; Starlinger, M.

    1993-01-01

    Evacuation proctography is the most important imaging technique to supplement findings of physical examination, manometry, and endoscopy in patients presenting with pathologies in anorectal morphology and function. Indications for evacuation proctography include obstructed defecation or incomplete evacuation, imaging of ileal pouches following excision of the rectum, and suspected anorectal fistulae. Evacuation proctography with thick barium sulfate is performed under fluoroscopy. Documentation of the study can either be done by single-shot X-rays, video recording, or imaging with a 100-mm spot-film camera. Evacuation proctography shows morphologic changes such as spastic pelvic floor, rectocele, enterocele, intussusception and anal prolapse. Measurements can be performed to obtain the anorectal angle, location and mobility of the pelvic floor, and size as well as importance of a rectocele. Qualitative and quantitative data can only be interpreted along with clinical and manometric data. (orig.) [de

  7. PIXE and {mu}-PIXE analysis of glazes from terracotta sculptures of the della Robbia workshop

    Energy Technology Data Exchange (ETDEWEB)

    Zucchiatti, Alessandro E-mail: zucc@ge.infn.it; Bouquillon, Anne; Lanterna, Giancarlo; Franco, Lucarelli; Mando, Pier Andrea; Prati, Paolo; Salomon, Joseph; Vaccari, Maria Grazia

    2002-04-01

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

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

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  9. Potential application of glazed transpired collectors to space heating in cold climates

    International Nuclear Information System (INIS)

    Gao, Lixin; Bai, Hua; Mao, Shufeng

    2014-01-01

    Highlights: • A mathematical model for glazed transpired collectors (GTC) is developed. • Glazing results in optical loss, but it decreases convective heat loss effectively. • Thermal performance of GTC shows considerable improvement on flat-plate collectors. • GTC using recirculated air is applicable to space heating in cold climates. - Abstract: Although unglazed transpired collectors (UTC) succeed in industrial ventilation applications, solar fraction is very low when they are used in space heating in cold climates due to the lower exit air temperature. Considering the potential for glazed transpired collectors (GTC) using recirculated air for space heating applications in cold climates, a mathematical model is developed for predicting the thermal performance of GTC. Simulation results show that although glazing results in optical loss, it could decrease convective heat loss resulted from high crosswind velocities effectively. For a solar radiation of 400 W/m 2 , an ambient temperature of −10 °C, and a suction velocity of 0.01 m/s, the exit air temperature of GTC is higher than that of UTC for crosswind velocities exceeding 3.0 m/s. By comparison with a conventional flat-plate solar air collector operating under the same conditions, the thermal performance of GTC shows a significant improvement. For a five-storey hotel building located in the severe cold climate zone of China, case study shows that the annual solar fraction of the GTC-based solar air heating system is about 20%, which is two times higher than that of the flat-plate collector-based system and nearly nine times higher than that of the UTC-based system respectively. Hence, an enormous amount of energy will be saved with the application of GTC to space heating in cold climates

  10. Research on evacuation planning as nuclear emergency preparedness

    International Nuclear Information System (INIS)

    Yamamoto, Kazuya

    2007-10-01

    The International Atomic Energy Agency (IAEA) has introduced new concepts of precautionary action zone (PAZ) and urgent protective action planning zone (UPZ) in 'Preparedness and Response for a Nuclear or Radiological Emergency' (GS-R-2 (2002)), in order to reduce substantially the risk of severe deterministic health effects. Open literature based research was made to reveal problems on evacuation planning and the preparedness for nuclear emergency arising from introduction of PAZ into Japan that has applied the emergency planning zone (EPZ) concept currently. In regard to application of PAZ, it should be noted that the requirements for preparedness and response for a nuclear or radiological emergency are not only dimensional but also timely. The principal issue is implementation of evacuation of precautionary decided area within several hours. The logic of evacuation planning for a nuclear emergency and the methods of advance public education and information in the U.S. is effective for even prompt evacuation to the outside of the EPZ. As concerns evacuation planning for a nuclear emergency in Japan, several important issues to be considered were found, that is, selection of public reception centers which are outside area of the EPZ, an unique reception center assigned to each emergency response planning area, public education and information of practical details about the evacuation plan in advance, and necessity of the evacuation time estimates. To establish a practical evacuation planning guide for nuclear emergencies, further researches on application of traffic simulation technology to evacuation time estimates and on knowledge of actual evacuation experience in natural disasters and chemical plant accidents are required. (author)

  11. Property control of graphene aerogels by in situ growth of silicone polymer

    Science.gov (United States)

    Zhou, Shuai; Zhou, Xiang; Hao, Gazi; Jiang, Wei; Wang, Tianhe

    2018-05-01

    Modulation of the density (from 3.5 to 64 mg cm-3), hydrophobicity and oil-uptake capability of graphene aerogels in extensive ranges were achieved by reacting (3-Mercaptopropyl)trimethoxysilane (MPS) with graphene oxide solutions under heating. The reaction allowed a characteristic silicone substructure to be formed on graphene and joint the graphene layers firmly together. With the increase of MPS concentrations (≤ca. 0.2 vol%), the nano silicone polymer grown on graphene functioned as a "linker" and "spacer", leading to a substantial decrease of the aerogel density. Because of the formation of silicone polymer and the characteristic nano-micro substructures on the backbones of graphene aerogels, the graphene aerogels exhibited a high hydrophobicity with the water contact angle consistently exceeding 142 degrees. Functionalized graphene aerogels with a density of 3.5 mg cm-3 were conveniently fabricated that displayed an extraordinary oil absorption capacity, 182 times for lubricating oil and 143 times for n-hexane of its own weight. Furthermore, the aerogels maintained their ultra-high absorption capability even after 20 absorption-distillation cycles, due to structural integrity held by the strong interfacial adhesion between graphene sheets and polymer chains of aerogels. This study offers a promising graphene aerogels and also provides a strategy for fabricating extra low dense functional materials.

  12. Simulation and Analysis of Mechanical Properties of Silica Aerogels: From Rationalization to Prediction

    Directory of Open Access Journals (Sweden)

    Hao Ma

    2018-01-01

    Full Text Available Silica aerogels are highly porous 3D nanostructures and have exhibited excellent physio-chemical properties. Although silica aerogels have broad potential in many fields, the poor mechanical properties greatly limit further applications. In this study, we have applied the finite volume method (FVM method to calculate the mechanical properties of silica aerogels with different geometric properties such as particle size, pore size, ligament diameter, etc. The FVM simulation results show that a power law correlation existing between relative density and mechanical properties (elastic modulus and yield stress of silica aerogels, which are consistent with experimental and literature studies. In addition, depending on the relative densities, different strategies are proposed in order to synthesize silica aerogels with better mechanical performance by adjusting the distribution of pore size and ligament diameter of aerogels. Finally, the results suggest that it is possible to synthesize silica aerogels with ultra-low density as well as high strength and stiffness as long as the textural features are well controlled. It is believed that the FVM simulation methodology could be a valuable tool to study mechanical performance of silica aerogel based materials in the future.

  13. Alumina/silica aerogel with zinc chloride as an alkylation catalyst

    Directory of Open Access Journals (Sweden)

    DEJAN U. SKALA

    2001-10-01

    Full Text Available The alumina/silica with zinc chloride aerogel alkylation catalyst was obtained using a one step sol-gel synthesis, and subsequent drying with supercritical carbon dioxide. The aerogel catalyst activity was found to be higher compared to the corresponding xerogel catalyst, as a result of the higher aerogel surface area, total pore volume and favourable pore size distribution. Mixed Al–O–Si bonds were present in both gel catalyst types. Activation by thermal treatment in air was needed prior to catalytic alkylation, due to the presence of residual organic groups on the aerogel surface. The optimal activation temperature was found to be in the range 185–225°C, while higher temperatures resulted in the removal of zinc chloride from the surface of the aerogel catalyst with a consequential decrease in the catalytic activity. On varying the zinc chloride content, the catalytic activity of the aerogel catalyst exhibited a maximum. High zinc chloride contents decreased the catalytic activity of the aerogel catalyst as the result of the pores of the catalyst being plugged with this compound, and the separation of the alumina/silica support into Al-rich and Si-rich phases. The surface area, total pore volume, pore size distribution and zinc chloride content had a similar influence on the activity of the aerogel catalyst as was the case of xerogel catalyst and supported zinc chloride catalysts.

  14. Simulation and Analysis of Mechanical Properties of Silica Aerogels: From Rationalization to Prediction.

    Science.gov (United States)

    Ma, Hao; Zheng, Xiaoyang; Luo, Xuan; Yi, Yong; Yang, Fan

    2018-01-30

    Silica aerogels are highly porous 3D nanostructures and have exhibited excellent physio-chemical properties. Although silica aerogels have broad potential in many fields, the poor mechanical properties greatly limit further applications. In this study, we have applied the finite volume method (FVM) method to calculate the mechanical properties of silica aerogels with different geometric properties such as particle size, pore size, ligament diameter, etc. The FVM simulation results show that a power law correlation existing between relative density and mechanical properties (elastic modulus and yield stress) of silica aerogels, which are consistent with experimental and literature studies. In addition, depending on the relative densities, different strategies are proposed in order to synthesize silica aerogels with better mechanical performance by adjusting the distribution of pore size and ligament diameter of aerogels. Finally, the results suggest that it is possible to synthesize silica aerogels with ultra-low density as well as high strength and stiffness as long as the textural features are well controlled. It is believed that the FVM simulation methodology could be a valuable tool to study mechanical performance of silica aerogel based materials in the future.

  15. Optimization of an aerogel cerenkov detector having a mirror light collection system

    International Nuclear Information System (INIS)

    Johansson, K.E.; Aakesson, T.; Norrby, J.

    1979-01-01

    Cerenkov detectors with silica aerogel of refractive indec 1.03 as the radiator have been tested in a particle beam at the CERN Proton Synchrotron. With a detector surface of 22 x 50 cm 2 and 9 cm thickness of aerogel, the number of photoelectrons was found to be 6.5 for β = 1 particles. (author)

  16. Preparation and characterization of silica aerogels from diatomite via ambient pressure drying

    Science.gov (United States)

    Wang, Baomin; Ma, Hainan; Song, Kai

    2014-07-01

    The silica aerogels were successfully fabricated under ambient pressure from diatomite. The influence of different dilution ratios of diatomite filtrate on physical properties of aerogels were studied. The microstructure, surface functional groups, thermal stability, morphology and mechanical properties of silica aerogels based on diatomite were investigated by BET adsorption, FT-IR, DTA-TG, FESEM, TEM, and nanoindentation methods. The results indicate that the filtrate diluted with distilled water in a proportion of 1: 2 could give silica aerogels in the largest size with highest transparency. The obtained aerogels with density of 0.122-0.203 g/m3 and specific surface area of 655.5-790.7 m2/g are crack free amorphous solids and exhibited a sponge-like structure. Moreover, the peak pore size resided at 9 nm. The initial aerogels were hydrophobic, when being heat-treated around 400°C, the aerogels were transformed into hydrophilic ones. The obtained aerogel has good mechanical properties.

  17. Functionalized silica aerogels for gas-phase purification, sensing, and catalysis: A review

    Energy Technology Data Exchange (ETDEWEB)

    Amonette, James E.; Matyáš, Josef

    2017-09-01

    Silica aerogels have a rich history and a unique, fascinating gas-phase chemistry that has lent them to many diverse applications. This review starts with a brief discussion of the fundamental issues driving the movement of gases in silica aerogels and then proceeds to provide an overview of the work that has been done with respect to the purification of gases, sensing of individual gases, and uses of silica aerogels as catalysts for gas-phase reactions. Salient features of the research behind these different applications are presented, and, where appropriate, critical aspects that affect the practical use of the aerogels are noted. Specific sections under the gas-purification category focus on the removal of airborne nanoparticles, carbon dioxide, volatile organic compounds, sulfur gases and radioactive iodine from gas streams. The use of silica aerogels as sensors for humidity, oxygen, hydrocarbons, volatile acids and bases, various non-ammoniacal nitrogen gases, and viral particles is discussed. With respect to catalysis, the demonstrated use of silica aerogels as supports for oxidation, Fischer-Tropsch, alkane isomerization, and hydrogenation reactions is reviewed, along with a section on untested catalytic formulations involving silica aerogels. A short section focuses on recent developments in thermomolecular Knudsen compressor pumps using silica aerogel membranes. The review continues with an overview of the production methods, locations of manufacturing facilities globally, and a brief discussion of the economics before concluding with a few remarks about the present and future trends revealed by the work presented.

  18. Low-temperature specific-heat and thermal-conductivity of silica aerogels

    DEFF Research Database (Denmark)

    Bernasconi, A.; Sleator, T.; Posselt, D.

    1992-01-01

    Specific heat, C(p), and thermal conductivity, lambda, have been measured on a series of base-catalyzed silica aerogels at temperatures between 0.05 and 20 K. Results for both C(p)(T) and lambda(T) confirm that the different length-scale regions observed in the aerogel structure are reflected...

  19. Study parameters process for production of red glazed ceramic plates with waste of stones

    International Nuclear Information System (INIS)

    Santos, J.C.; Taguchi, S.P.; Silva, A.C.

    2014-01-01

    The volume of fine waste's solid dimension stone industry has required a destination appropriate for them due to environmental and economic issues. The main goal of this work was to study the produce plates of glazed pottery with dimension stone waste. For analyzing the crystal structure, the test was conducted X-ray and X-ray fluorescence to determine the chemical composition of clay and the waste. Particle size was analysed too. Ceramic duo type (120x30x10mm) were sintered at 1280° C for 15 and 60 minutes. Characterized the samples for water absorption. The glaze had a strong anchorage in the ceramic base, but the high melting temperature caused cracks in the ceramic base, increasing the water absorption values. Thus, flux was added, based on the phase diagram Na_2O: CaO: SiO_2, which reduced the melting temperature of the glaze to 980 °C, enabling to produce the ceramic at 1100°C for 30 minutes, more uniform surface and best technological properties. (author)

  20. Analysis of Damage in Laminated Architectural Glazing Subjected to Wind Loading and Windborne Debris Impact

    Directory of Open Access Journals (Sweden)

    Daniel S. Stutts

    2013-05-01

    Full Text Available Wind loading and windborne debris (missile impact are the two primary mechanisms that result in window glazing damage during hurricanes. Wind-borne debris is categorized into two types: small hard missiles; such as roof gravel; and large soft missiles representing lumber from wood-framed buildings. Laminated architectural glazing (LAG may be used in buildings where impact resistance is needed. The glass plies in LAG undergo internal damage before total failure. The bulk of the published work on this topic either deals with the stress and dynamic analyses of undamaged LAG or the total failure of LAG. The pre-failure damage response of LAG due to the combination of wind loading and windborne debris impact is studied. A continuum damage mechanics (CDM based constitutive model is developed and implemented via an axisymmetric finite element code to study the failure and damage behavior of laminated architectural glazing subjected to combined loading of wind and windborne debris impact. The effect of geometric and material properties on the damage pattern is studied parametrically.

  1. 2004 Survey of United States architects on the subject of switchable glazings

    International Nuclear Information System (INIS)

    Sottile, G.M.

    2005-01-01

    The 21st century has ushered in an era marked by the growing integration of technology and other scientific advances into commercial buildings and residential homes. Of particular interest to many architects, developers and builders are 'switchable' glazing, a new category of technologically advanced glass and plastic building materials that can be used to control light, glare and heat entering an office or a home. Interest in switchable glazing technology is influenced by a variety of factors, including a growing movement to offer sustainable, energy-efficient building solutions, and the emerging desire by users to maintain greater control over their working and living environments. This paper examines the movement toward sustainable development and the end-user needs that are driving it. Further, it presents the results of a proprietary survey research study of United States architects on the subject of switchable glazing. This study includes an examination of the attributes most desired by architects regarding smart window technology, and provides additional insight into the potential application of this smart material to the building community

  2. Time-Dependent Effects of Glaze Ice on the Aerodynamic Characteristics of an Airfoil

    Directory of Open Access Journals (Sweden)

    Narges Tabatabaei

    2018-01-01

    Full Text Available The main objective of this study is to estimate the dynamic loads acting over a glaze-iced airfoil. This work studies the performance of unsteady Reynolds-averaged Navier-Stokes (URANS simulations in predicting the oscillations over an iced airfoil. The structure and size of time-averaged vortices are compared to measurements. Furthermore, the accuracy of a two-equation eddy viscosity turbulence model, the shear stress transport (SST model, is investigated in the case of the dynamic load analysis over a glaze-iced airfoil. The computational fluid dynamic analysis was conducted to investigate the effect of critical ice accretions on a 0.610 m chord NACA 0011 airfoil. Leading edge glaze ice accretion was simulated with flat plates (spoiler-ice extending along the span of the blade. Aerodynamic performance coefficients and pressure profiles were calculated and validated for the Reynolds number of 1.83 × 106. Furthermore, turbulent separation bubbles were studied. The numerical results confirm both time-dependent phenomena observed in previous similar measurements: (1 low-frequency mode, with a Strouhal number Sth≈0,013–0.02, and (2 higher frequency mode with a Strouhal number StL≈0,059–0.69. The higher frequency motion has the same characteristics as the shedding mode and the lower frequency motion has the flapping mode characteristics.

  3. Highly Porous, Rigid-Rod Polyamide Aerogels with Superior Mechanical Properties and Unusually High Thermal Conductivity.

    Science.gov (United States)

    Williams, Jarrod C; Nguyen, Baochau N; McCorkle, Linda; Scheiman, Daniel; Griffin, Justin S; Steiner, Stephen A; Meador, Mary Ann B

    2017-01-18

    We report here the fabrication of polyamide aerogels composed of poly-p-phenylene-terephthalamide, the same backbone chemistry as DuPont's Kevlar. The all-para-substituted polymers gel without the use of cross-linker and maintain their shape during processing-an improvement over the meta-substituted cross-linked polyamide aerogels reported previously. Solutions containing calcium chloride (CaCl 2 ) and para-phenylenediamine (pPDA) in N-methylpyrrolidinone (NMP) at low temperature are reacted with terephthaloyl chloride (TPC). Polymerization proceeds over the course of 5 min resulting in gelation. Removal of the reaction solvent via solvent exchange followed by extraction with supercritical carbon dioxide provides aerogels with densities ranging from 0.1 to 0.3 g/cm 3 , depending on the concentration of calcium chloride, the formulated number of repeat units, n, and the concentration of polymer in the reaction mixture. These variables were assessed in a statistical experimental study to understand their effects on the properties of the aerogels. Aerogels made using at least 30 wt % CaCl 2 had the best strength when compared to aerogels of similar density. Furthermore, aerogels made using 30 wt % CaCl 2 exhibited the lowest shrinkage when aged at elevated temperatures. Notably, whereas most aerogel materials are highly insulating (thermal conductivities of 10-30 mW/m K), the polyamide aerogels produced here exhibit remarkably high thermal conductivities (50-80 mW/(m K)) at the same densities as other inorganic and polymer aerogels. These high thermal conductivities are attributed to efficient phonon transport by the rigid-rod polymer backbone. In conjunction with their low cost, ease of fabrication with respect to other polymer aerogels, low densities, and high mass-normalized strength and stiffness properties, these aerogels are uniquely valuable for applications such as lightweighting in consumer electronics, automobiles, and aerospace where weight reduction is

  4. X-ray radiographic technique for measuring density uniformity of silica aerogel

    International Nuclear Information System (INIS)

    Tabata, Makoto; Hatakeyama, Yoshikiyo; Adachi, Ichiro; Morita, Takeshi; Nishikawa, Keiko

    2013-01-01

    This paper proposes a new X-ray radiographic technique for measuring density uniformity of silica aerogels used as radiator in proximity-focusing ring-imaging Cherenkov detectors. To obtain high performance in a large-area detector, a key characteristic of radiator is the density (i.e. refractive index) uniformity of an individual aerogel monolith. At a refractive index of n=1.05, our requirement for the refractive index uniformity in the transverse plane direction of an aerogel tile is |δ(n−1)/(n−1)|<4% in a focusing dual layer radiator (with different refractive indices) scheme. We applied the radiographic technique to evaluate the density uniformity of our original aerogels from a trial production and that of Panasonic products (SP-50) as a reference, and to confirm they have sufficient density uniformity within ±1% along the transverse plane direction. The measurement results show that the proposed technique can quantitatively estimate the density uniformity of aerogels.

  5. Supercritical methanol drying as a convenient route to phenolic-furfural aerogels

    Energy Technology Data Exchange (ETDEWEB)

    Albert, Donald F.; Bruno, Joseph W. [Department of Chemistry, Wesleyan University, 06459 Middletown, CT (United States); Andrews, Greg R.; Mendenhall, Robert S. [American Aerogel Corporation, 1000 Corporate Row, 06416 Cromwell, CT (United States)

    2001-12-01

    Organic aerogels are prepared by the acid catalyzed cross-linking of phenolic-furfural (PF) precursors in methanol solution, and the solvent is subsequently removed at high temperature as the supercritical fluid. The resulting aerogel is a brown opaque solid and has been prepared as 30 ml cylindrical monoliths exhibiting little or no shrinkage during formation. These solids, which are routinely available with a density as low as ca. 125mg/cm{sup 3}, have been characterized by chemical methods (infrared spectroscopy and CP-MAS 13C NMR spectrometry) and physical techniques (Brunauer-Emmet-Teller surface area, transmission and scanning electron microscopy). In addition, thermal conductivities have been determined, and show that the PF aerogels are excellent thermal insulators. These studies establish that the materials described herein exhibit chemical and physical properties very similar to those seen for organic aerogels prepared with low temperature processing techniques. The current method constitutes a convenient and rapid route to organic aerogels.

  6. Synthesis of Porous and Mechanically Compliant Carbon Aerogels Using Conductive and Structural Additives

    Directory of Open Access Journals (Sweden)

    Carlos Macias

    2016-01-01

    Full Text Available We report the synthesis of conductive and mechanically compliant monolithic carbon aerogels prepared by sol-gel polycondensation of melamine-resorcinol-formaldehyde (MRF mixtures by incorporating diatomite and carbon black additives. The resulting aerogels composites displayed a well-developed porous structure, confirming that the polymerization of the precursors is not impeded in the presence of either additive. The aerogels retained the porous structure after etching off the siliceous additive, indicating adequate cross-linking of the MRF reactants. However, the presence of diatomite caused a significant fall in the pore volumes, accompanied by coarsening of the average pore size (predominance of large mesopores and macropores. The diatomite also prevented structural shrinkage and deformation of the as-prepared monoliths upon densification by carbonization, even after removal of the siliceous framework. The rigid pristine aerogels became more flexible upon incorporation of the diatomite, favoring implementation of binderless monolithic aerogel electrodes.

  7. Reduced graphene oxide aerogel networks with soft interfacial template for applications in bone tissue regeneration

    Science.gov (United States)

    Asha, S.; Ananth, A. Nimrodh; Jose, Sujin P.; Rajan, M. A. Jothi

    2018-05-01

    Reduced Graphene Oxide aerogels (A-RGO), functionalized with chitosan, were found to induce and/or accelerate the mineralization of hydroxyapatite. The functionalized chitosan acts as a soft interfacial template on the surface of A-RGO assisting the growth of hydroxyapatite particles. The mineralization on these soft aerogel networks was performed by soaking the aerogels in simulated body fluid, relative to time. Polymer-induced mineralization exhibited an ordered arrangement of hydroxyapatite particles on reduced graphene oxide aerogel networks with a higher crystalline index (IC) of 1.7, which mimics the natural bone formation indicating the importance of the polymeric interfacial template. These mineralized aerogels which mimic the structure and composition of natural bone exhibit relatively higher rate of cell proliferation, osteogenic differentiation and osteoid matrix formation proving it to be a potential scaffold for bone tissue regeneration.

  8. Silica aerogel Cherenkov counter for the KEK B-factory experiment

    CERN Document Server

    Sumiyoshi, T; Enomoto, R; Iijima, T; Suda, R; Leonidopoulos, C; Marlow, D R; Prebys, E; Kawabata, R; Kawai, H; Ooba, T; Nanao, M; Suzuki, K; Ogawa, S; Murakami, A; Khan, M H R

    1999-01-01

    Low-refractive-index silica aerogel is a convenient radiator for threshold-type Cherenkov counters, which are used for particle identification in high-energy physics experiments. For the BELLE detector at the KEK B-Factory we have produced about 2 m sup 3 of hydrophobic silica aerogels of n=1.01-1.03 using a new production method. The particle identification capability of the aerogel Cherenkov counters was tested and 3 sigma pion/proton separation has been achieved at 3.5 GeV/c. Radiation hardness of the aerogels was confirmed up to 9.8 Mrad. The Aerogel Cherenkov counter system (ACC) was successfully installed in the BELLE just before this conference.

  9. The Relation between the Rheological Properties of Gels and the Mechanical Properties of Their Corresponding Aerogels

    Directory of Open Access Journals (Sweden)

    Mingze Sun

    2018-04-01

    Full Text Available A series of low density, highly porous clay/poly(vinyl alcohol composite aerogels, incorporating ammonium alginate, were fabricated via a convenient and eco-friendly freeze drying method. It is significant to understand rheological properties of precursor gels because they directly affect the form of aerogels and their processing behaviors. The introduction of ammonium alginate impacted the rheological properties of colloidal gels and improved the mechanical performance of the subject aerogels. The specific compositions and processing conditions applied to those colloidal gel systems brought about different aerogel morphologies, which in turn translated into the observed mechanical properties. The bridge between gel rheologies and aerogel structures are established in the present work.

  10. Plasmonic Aerogels as a Three-Dimensional Nanoscale Platform for Solar Fuel Photocatalysis.

    Science.gov (United States)

    DeSario, Paul A; Pietron, Jeremy J; Dunkelberger, Adam; Brintlinger, Todd H; Baturina, Olga; Stroud, Rhonda M; Owrutsky, Jeffrey C; Rolison, Debra R

    2017-09-19

    We use plasmonic Au-TiO 2 aerogels as a platform in which to marry synthetically thickened particle-particle junctions in TiO 2 aerogel networks to Au∥TiO 2 interfaces and then investigate their cooperative influence on photocatalytic hydrogen (H 2 ) generation under both broadband (i.e., UV + visible light) and visible-only excitation. In doing so, we elucidate the dual functions that incorporated Au can play as a water reduction cocatalyst and as a plasmonic sensitizer. We also photodeposit non-plasmonic Pt cocatalyst nanoparticles into our composite aerogels in order to leverage the catalytic water-reducing abilities of Pt. This Au-TiO 2 /Pt arrangement in three dimensions effectively utilizes conduction-band electrons injected into the TiO 2 aerogel network upon exciting the Au SPR at the Au∥TiO 2 interface. The extensive nanostructured high surface-area oxide network in the aerogel provides a matrix that spatially separates yet electrochemically connects plasmonic nanoparticle sensitizers and metal nanoparticle catalysts, further enhancing solar-fuels photochemistry. We compare the photocatalytic rates of H 2 generation with and without Pt cocatalysts added to Au-TiO 2 aerogels and demonstrate electrochemical linkage of the SPR-generated carriers at the Au∥TiO 2 interfaces to downfield Pt nanoparticle cocatalysts. Finally, we investigate visible light-stimulated generation of conduction band electrons in Au-TiO 2 and TiO 2 aerogels using ultrafast visible pump/IR probe spectroscopy. Substantially more electrons are produced at Au-TiO 2 aerogels due to the incorporated SPR-active Au nanoparticle, whereas the smaller population of electrons generated at Au-free TiO 2 aerogels likely originate at shallow traps in the high surface-area mesoporous aerogel.

  11. Illustration of compositional variations over time of Chinese porcelain glazes combining micro-X-ray Fluorescence spectrometry, multivariate data analysis and Seger formulas

    International Nuclear Information System (INIS)

    Van Pevenage, J.; Verhaeven, E.; Vekemans, B.; Lauwers, D.; Herremans, D.; De Clercq, W.; Vincze, L.; Moens, L.; Vandenabeele, P.

    2015-01-01

    In this research, the transparent glaze layers of Chinese porcelain samples were investigated. Depending on the production period, these samples can be divided into two groups: the samples of group A dating from the Kangxi period (1661–1722), and the samples of group B produced under emperor Qianlong (1735–1795). Due to the specific sample preparation method and the small spot size of the X-ray beam, investigation of the transparent glaze layers is enabled. Despite the many existing research papers about glaze investigations of ceramics and/or porcelain ware, this research reveals new insights into the glaze composition and structure of Chinese porcelain samples. In this paper it is demonstrated, using micro-X-ray Fluorescence (μ-XRF) spectrometry, multivariate data analysis and statistical analysis (Hotelling's T-Square test) that the transparent glaze layers of the samples of groups A and B are significantly different (95% confidence level). Calculation of the Seger formulas, enabled classification of the glazes. Combining all the information, the difference in composition of the Chinese porcelain glazes of the Kangxi period and the Qianlong period can be demonstrated. - Highlights: • Fully described methodology for the analysis of silicate glazes of Chinese porcelain samples • The combination of a semi-quantitative analysis of silicate glazes, multi-variate data and statistical analysis. • The use of Seger formula to understand better the composition of the glazes. • New insights into the glaze composition and structure of Chinese porcelain glazes of different time periods

  12. Illustration of compositional variations over time of Chinese porcelain glazes combining micro-X-ray Fluorescence spectrometry, multivariate data analysis and Seger formulas

    Energy Technology Data Exchange (ETDEWEB)

    Van Pevenage, J., E-mail: Raman@UGent.be [Department of Analytical Chemistry, Raman Spectroscopy Research Group, Ghent University, Krijgslaan 281, S12, B-9000 Ghent (Belgium); Verhaeven, E. [Department of Conservation and Restoration, University College Antwerp, Blindestraat 9, B-2000 Antwerp (Belgium); Vekemans, B. [Department of Analytical Chemistry, Ghent University, Krijgslaan 281, S12, B-9000 Ghent (Belgium); Lauwers, D., E-mail: Raman@UGent.be [Department of Analytical Chemistry, Raman Spectroscopy Research Group, Ghent University, Krijgslaan 281, S12, B-9000 Ghent (Belgium); Herremans, D.; De Clercq, W. [Department of Archaeology, Ghent University, Sint-Pietersnieuwstraat 35, B-9000 Ghent (Belgium); Vincze, L. [Department of Analytical Chemistry, Ghent University, Krijgslaan 281, S12, B-9000 Ghent (Belgium); Moens, L., E-mail: Raman@UGent.be [Department of Analytical Chemistry, Raman Spectroscopy Research Group, Ghent University, Krijgslaan 281, S12, B-9000 Ghent (Belgium); Vandenabeele, P. [Department of Archaeology, Ghent University, Sint-Pietersnieuwstraat 35, B-9000 Ghent (Belgium)

    2015-01-01

    In this research, the transparent glaze layers of Chinese porcelain samples were investigated. Depending on the production period, these samples can be divided into two groups: the samples of group A dating from the Kangxi period (1661–1722), and the samples of group B produced under emperor Qianlong (1735–1795). Due to the specific sample preparation method and the small spot size of the X-ray beam, investigation of the transparent glaze layers is enabled. Despite the many existing research papers about glaze investigations of ceramics and/or porcelain ware, this research reveals new insights into the glaze composition and structure of Chinese porcelain samples. In this paper it is demonstrated, using micro-X-ray Fluorescence (μ-XRF) spectrometry, multivariate data analysis and statistical analysis (Hotelling's T-Square test) that the transparent glaze layers of the samples of groups A and B are significantly different (95% confidence level). Calculation of the Seger formulas, enabled classification of the glazes. Combining all the information, the difference in composition of the Chinese porcelain glazes of the Kangxi period and the Qianlong period can be demonstrated. - Highlights: • Fully described methodology for the analysis of silicate glazes of Chinese porcelain samples • The combination of a semi-quantitative analysis of silicate glazes, multi-variate data and statistical analysis. • The use of Seger formula to understand better the composition of the glazes. • New insights into the glaze composition and structure of Chinese porcelain glazes of different time periods.

  13. Research on Evacuation Based on Social Force Model

    Science.gov (United States)

    Liu, W.; Deng, Z.; Li, W.; Lin, J.

    2017-09-01

    Crowded centers always cause personnel casualties in evacuation operations. Stampede events often occur by hit, squeeze and crush due to panic. It is of vital important to alleviate such situation. With the deepening of personnel evacuation research, more and more researchers are committed to study individual behaviors and self-organization phenomenon in evacuation process. The study mainly includes: 1, enrich the social force model from different facets such as visual, psychological, external force to descript more realistic evacuation; 2, research on causes and effects of self - organization phenomenon. In this paper, we focus on disorder motion that occurs in the crowded indoor publics, especially the narrow channel and safety exits and other special arteries. We put forward the improved social force model to depict pedestrians' behaviors, an orderly speed-stratification evacuation method to solve disorder problem, and shape-changed export to alleviate congestion. The result of this work shows an improvement of evacuation efficiency by 19.5 %. Guiding pedestrians' direction to slow down the influence of social forces has a guidance function in improving the efficiency of indoor emergency evacuation.

  14. Synthesis, Processing, and Characterization of Inorganic-Organic Hybrid Cross-Linked Silica, Organic Polyimide, and Inorganic Aluminosilicate Aerogels

    Science.gov (United States)

    Nguyen, Baochau N.; Guo, Haiquan N.; McCorkle, Linda S.

    2014-01-01

    As aerospace applications become ever more demanding, novel insulation materials with lower thermal conductivity, lighter weight and higher use temperature are required to fit the aerospace application needs. Having nanopores and high porosity, aerogels are superior thermal insulators, among other things. The use of silica aerogels in general is quite restricted due to their inherent fragility, hygroscopic nature, and poor mechanical properties, especially in extereme aerospace environments. Our research goal is to develop aerogels with better mechanical and environmental stability for a variety of aeronautic and space applications including space suit insulation for planetary surface missions, insulation for inflatable structures for habitats, inflatable aerodynamic decelerators for entry, descent and landing (EDL) operations, and cryotank insulation for advance space propulsion systems. Different type of aerogels including organic-inorganic polymer reinforced (hybrid) silica-based aerogels, polyimide aerogels and inorganic aluminosilicate aerogels have been developed and examined.

  15. Green synthesis of amphipathic graphene aerogel constructed by using the framework of polymer-surfactant complex for water remediation

    Science.gov (United States)

    Cao, Jingjing; Wang, Ziyuan; Yang, Xianhou; Tu, Jing; Wu, Ronglan; Wang, Wei

    2018-06-01

    Graphene aerogels have been extensively studied in water treatment and oil remediation. We report a mild and green method to prepare a 3D-columnar graphene aerogel. The aerogel was synthesized by using polyvinyl alcohol (PVA) and stearic acid (SA) as crosslinking agents to construct a framework of reduced graphene oxide (RGO). The interaction between PVA, SA, and stacked RGO sheets created a mechanically very robust aerogel. The aerogel possesses ultra-light performance with the destiny ranging from 4.9 to 10 mg cm-3. The aerogel also demonstrated ultrafast oil absorption, good fire-resistance, and excellent mechanical properties. The adsorptive capacities are in the range of 105-250 times of its original weight for various organic liquids after the absorption. The aerogel also exhibited a strong durability and reusability, and after ten cycles of absorbing-squeezing, the adsorptive capacity is nearly unchanged, indicating potential application in practical oil remediation.

  16. An analysis of evacuation options for nuclear accidents

    Energy Technology Data Exchange (ETDEWEB)

    Tawil, J J; Strenge, D L; Schultz, R W

    1987-11-01

    The threat of release of a hazardous substance into the atmosphere will sometimes require that the population at risk be evacuated. If the substance is particularly hazardous or the release is exceptionally large, then an extensive area may have to be evacuated at substantial cost. In this report we consider the threat posed by the accidental release of radionuclides from a nuclear power plant. The report's objective is to establish relationships between radiation dose and the cost of evacuation under a wide variety of conditions. The dose can almost always be reduced by evacuating the population from a larger area. However, extending the evacuation zone outward will cause evacuation costs to increase. The purpose of this analysis was to provide the Environmental Protection Agency (EPA) a data base for evaluating whether implementation costs and risks averted could be used to justify evacuation at lower doses than would be required based on acceptable risk of health effects alone. The procedures used and results of these analyses are being made available as background information for use by others. In this report we develop cost/dose relationships for 54 scenarios that are based upon the severity of the reactor accident, meteorological conditions during the release of radionuclides into the environment, and the angular width of the evacuation zone. The 54 scenarios are derived from combinations of three accident severity levels, six meteorological conditions and evacuation zone widths of 70 deg, 90 deg, and 180 deg. Appendix tables are provided to allow acceptable evaluation of the cost/dose relationships for a wide variety of scenarios. Guidance and examples are provided in the text to show how these tables can be used.

  17. Development and sensitivity study of a simplified and dynamic method for double glazing facade and verified by a full-scale façade element

    DEFF Research Database (Denmark)

    Liu, Mingzhe; Wittchen, Kim Bjarne; Heiselberg, Per

    2014-01-01

    The research aims to develop a simplified calculation method for double glazing facade to calculate its thermal and solar properties (U and g value) together with comfort performance (internal surface temperature of the glazing). Double glazing is defined as 1D model with nodes representing......, taking the thermal mass of the glazing into account. In addition, angle and spectral dependency of solar characteristic is also considered during the calculation. By using the method, it is possible to calculate whole year performance at different time steps, which makes it a time economical and accurate...

  18. Development of a simplified and dynamic method for double glazing façade with night insulation and validated by full-scale façade element

    DEFF Research Database (Denmark)

    Liu, Mingzhe; Wittchen, Kim Bjarne; Heiselberg, Per

    2013-01-01

    The study aims to develop a simplified calculation method to simulate the performance of double glazing fac¸ ade with night insulation. This paper describes the method to calculate the thermal properties (Uvalue) and comfort performance (internal surface temperature of glazing) of the double...... with night insulation is calculated and compared with that of the facade without the night insulation. Based on standards EN 410 and EN 673, the method takes the thermal mass of glazing and the infiltration between the insulation layer and glazing into account. Furthermore it is capable of implementing whole...

  19. Analysis of elemental maps from glaze to body of ancient Chinese Jun and Ru porcelain by micro-X-ray fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Cheng Lin [Key Laboratory of Beam Technology and Material Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing Radiation Center, Beijing 100875 (China)], E-mail: chenglin@bnu.edu.cn; Li Rongwu [Department of Physics, Beijing Normal University, Beijing 100049 (China); Pan Qiuli [Key Laboratory of Beam Technology and Material Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing Radiation Center, Beijing 100875 (China); Li Guoxia; Zhao Weijuan [Institute of Physical Engineering, Zhengzhou University, Zhengzhou 450052 (China); Liu Zhiguo [Key Laboratory of Beam Technology and Material Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing Radiation Center, Beijing 100875 (China)

    2009-01-15

    The reasons how the middle layer of Ru and Jun porcelain between the glaze and body came into being are still not completely understood. Here, elemental maps from the glaze to the body of pieces of ancient Chinese Ru and Jun porcelain were analyzed by micro-X-ray fluorescence. The results show the middle layer was probably formed by the chemical composition of the glaze turning into glassy states and undergoing complex physical-chemical reactions with the body. However, the middle layer of Jun porcelain was formed by the chemical composition of the glaze turning into glassy states and then infiltrating the body at high temperatures during the firing process.

  20. Analysis of elemental maps from glaze to body of ancient Chinese Jun and Ru porcelain by micro-X-ray fluorescence

    Science.gov (United States)

    Cheng, Lin; Li, Rongwu; Pan, Qiuli; Li, Guoxia; Zhao, Weijuan; Liu, Zhiguo

    2009-01-01

    The reasons how the middle layer of Ru and Jun porcelain between the glaze and body came into being are still not completely understood. Here, elemental maps from the glaze to the body of pieces of ancient Chinese Ru and Jun porcelain were analyzed by micro-X-ray fluorescence. The results show the middle layer was probably formed by the chemical composition of the glaze turning into glassy states and undergoing complex physical-chemical reactions with the body. However, the middle layer of Jun porcelain was formed by the chemical composition of the glaze turning into glassy states and then infiltrating the body at high temperatures during the firing process.

  1. Application of Catastrophe Risk Modelling to Evacuation Public Policy

    Science.gov (United States)

    Woo, G.

    2009-04-01

    The decision by civic authorities to evacuate an area threatened by a natural hazard is especially fraught when the population in harm's way is extremely large, and where there is considerable uncertainty in the spatial footprint, scale, and strike time of a hazard event. Traditionally viewed as a hazard forecasting issue, civil authorities turn to scientists for advice on a potentially imminent dangerous event. However, the level of scientific confidence varies enormously from one peril and crisis situation to another. With superior observational data, meteorological and hydrological hazards are generally better forecast than geological hazards. But even with Atlantic hurricanes, the track and intensity of a hurricane can change significantly within a few hours. This complicated and delayed the decision to call an evacuation of New Orleans when threatened by Hurricane Katrina, and would present a severe dilemma if a major hurricane were appearing to head for New York. Evacuation needs to be perceived as a risk issue, requiring the expertise of catastrophe risk modellers as well as geoscientists. Faced with evidence of a great earthquake in the Indian Ocean in December 2004, seismologists were reluctant to give a tsunami warning without more direct sea observations. Yet, from a risk perspective, the risk to coastal populations would have warranted attempts at tsunami warning, even though there was significant uncertainty in the hazard forecast, and chance of a false alarm. A systematic coherent risk-based framework for evacuation decision-making exists, which weighs the advantages of an evacuation call against the disadvantages. Implicitly and qualitatively, such a cost-benefit analysis is undertaken by civic authorities whenever an evacuation is considered. With the progress in catastrophe risk modelling, such an analysis can be made explicit and quantitative, providing a transparent audit trail for the decision process. A stochastic event set, the core of a

  2. Endoscopic burr hole evacuation of an acute subdural hematoma.

    Science.gov (United States)

    Codd, Patrick J; Venteicher, Andrew S; Agarwalla, Pankaj K; Kahle, Kristopher T; Jho, David H

    2013-12-01

    Acute subdural hematoma evacuations frequently necessitate large craniotomies with extended operative times and high relative blood loss, which can lead to additional morbidity for the patient. While endoscopic minimally invasive approaches to chronic subdural collections have been successfully demonstrated, this technique has not previously been applied to acute subdural hematomas. The authors report their experience with an 87-year-old patient presenting with a large acute right-sided subdural hematoma successfully evacuated via an endoscopic minimally invasive technique. The operative approach is outlined, and the literature on endoscopic subdural collection evacuation reviewed. Copyright © 2013. Published by Elsevier Ltd.

  3. Evacuation of children - movement on stairs and on Horizontal Plane

    DEFF Research Database (Denmark)

    Larusdottir, Aldis Run; Dederichs, Anne

    2012-01-01

    in full scale evacuation experiments where two age groups 0-2 years and 3-6 years were analyzed separately. It was found that flow through doors, walking speeds and densities were age-dependent and differed strongly from the data in existing literature. The results showed higher walking speeds in spiral...... slower in horizontal plane than adults, however they were keen to run during the evacuations, in the latter case their travel speed increased and exceeded the adults’. Since the evacuation characteristics of children differ in many ways from those of adults, nowadays models badly comprehend...

  4. Effect of form of obstacle on speed of crowd evacuation

    Science.gov (United States)

    Yano, Ryosuke

    2018-03-01

    This paper investigates the effect of the form of an obstacle on the time that a crowd takes to evacuate a room, using a toy model. Pedestrians are modeled as active soft matter moving toward a point with intended velocities. An obstacle is placed in front of the exit, and it has one of four shapes: a cylindrical column, a triangular prism, a quadratic prism, or a diamond prism. Numerical results indicate that the evacuation-completion time depends on the shape of the obstacle. Obstacles with a circular cylinder (C.C.) shape yield the shortest evacuation-completion time in the proposed model.

  5. The Variable Scale Evacuation Model (VSEM: a new tool for simulating massive evacuation processes during volcanic crises

    Directory of Open Access Journals (Sweden)

    J. M. Marrero

    2010-04-01

    Full Text Available Volcanic eruptions are among the most awesome and powerful displays of nature's force, constituting a major natural hazard for society (a single eruption can claim thousands of lives in an instant. Consequently, assessment and management of volcanic risk have become critically important goals of modern volcanology. Over recent years, numerous tools have been developed to evaluate volcanic risk and support volcanic crisis management: probabilistic analysis of future eruptions, hazard and risk maps, event trees, etc. However, there has been little improvement in the tools that may help Civil Defense officials to prepare Emergency Plans. Here we present a new tool for simulating massive evacuation processes during volcanic crisis: the Variable Scale Evacuation Model (VSEM. The main objective of the VSEM software is to optimize the evacuation process of Emergency Plans during volcanic crisis. For this, the VSEM allows the simulation of an evacuation considering different strategies depending on diverse impact scenarios. VSEM is able to calculate the required time for the complete evacuation taking into account diverse evacuation scenarios (number and type of population, infrastructure, road network, etc. and to detect high-risk or "blackspots" of the road network. The program is versatile and can work at different scales, thus being capable of simulating the evacuation of small villages as well as huge cities.

  6. Ambient pressure dried tetrapropoxysilane-based silica aerogels with high specific surface area

    Science.gov (United States)

    Parale, Vinayak G.; Han, Wooje; Jung, Hae-Noo-Ree; Lee, Kyu-Yeon; Park, Hyung-Ho

    2018-01-01

    In the present paper, we report the synthesis of tetrapropoxysilane (TPOS)-based silica aerogels with high surface area and large pore volume. The silica aerogels were prepared by a two-step sol-gel process followed by surface modification via a simple ambient pressure drying approach. In order to minimize drying shrinkage and obtain hydrophobic aerogels, the surface of the alcogels was modified using trichloromethylsilane as a silylating agent. The effect of the sol-gel compositional parameters on the polymerization of aerogels prepared by TPOS, one of the precursors belonging to the Si(OR)4 family, was reported for the first time. The oxalic acid and NH4OH concentrations were adjusted to achieve good-quality aerogels with high surface area, low density, and high transparency. Controlling the hydrolysis and condensation reactions of the TPOS precursor turned out to be the most important factor to determine the pore characteristics of the aerogel. Highly transparent aerogels with high specific surface area (938 m2/g) and low density (0.047 g/cm3) could be obtained using an optimized TPOS/MeOH molar ratio with appropriate concentrations of oxalic acid and NH4OH.

  7. The effect of glaze on the quality of frozen stored Alaska pollack (Theragra chalcogramma fillets under stable and unstable conditions

    Directory of Open Access Journals (Sweden)

    Peter Žoldoš

    2011-01-01

    Full Text Available Frozen fillets (n = 288 of Alaska pollack (Theragra chalcogramma were used to evaluate the effect of glaze on lipid oxidation and microbiological indicators during 6 months of freezing storage under stable (−18 °C and unstable temperature (varying from −5 to −18 °C conditions. The amount of glaze, moisture, fat and protein content were measured. Despite the low fat content in Alaska pollack, a positive effect of glazing and stable freezing conditions of storage on the range of oxidative changes of lipids expressed as thiobarbituric acid reactive substances was found. Total counts of viable cells slightly rose before the end of the storage period in both groups with commercially glazed fish. The average counts of psychrotrophs in each group ( were at the same level, ranging from 9.1 ×103 CFU·g-1 to 1.1 × 104 CFU·g-1. According to the microbiological results fillets stored under unstable conditions were considered to be acceptable, but sensory evaluation showed that at the end of frozen storage they could not be consumed because of rancidity. Based on our results, glaze application ranged from 10 to 15% guarantee of final quality, however, prevention of temperature fluctuation during storage is important to keep the quality of the frozen fillets. This is the first similar study in Alaska pollack.

  8. Nondestructive determination of lead, cadmium, tin, antimony, and barium in ceramic glazes by radioisotope X-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    Anderson, D.L.; Cunningham, W.C.

    1996-01-01

    Quantitation capabilities of radioisotope X-ray fluorescence spectrometry (RXRFS) for determining lead, cadmium, tin, antimony, and barium in ceramic glazes were investigated. Twenty-one air-dried glazes and 85 fired glazes on test tiles were analyzed by using 109 Cd and 57 Co excitation sources. Accurate Pb determinations, with limits of detection (LODs) of about 0.3 mg/cm 2 for 5 min counting times, were achieved by using the 75 keV Κ α1 X-ray photopeak and a Pb foil calibration procedure. Cd, Sn, Sb, and Ba concentrations were determined with LODs from about 0.5 to 1.5 mg/cm 2 . For Pb and Ba, results obtained by using absorption corrections based only on element concentrations determined by RXRFS and an iterative approach led to analytical biases of ≤4% relative to results obtained by using corrections based on known total element compositions. Biases were more severe for Cd, Sn, and Sb because lower X-ray energies were involved and sensitivities varied as a function of matrix Pb content. Pb concentrations were above LODs (1.3-40 mg/cm 2 ) in 39 of 47 fired open-quotes food-safeclose quotes glazes and in 33 of the other 38 fired glazes (0.4-39 mg/cm 2 ). 15 refs., 9 figs., 9 tabs

  9. Planning for spontaneous evacuation during a radiological emergency

    International Nuclear Information System (INIS)

    Johnson, J.H. Jr.

    1984-01-01

    The Federal Emergency Management Agency's (FEMA's) radiological emergency preparedness program ignores the potential problem of spontaneous evacuation during a nuclear reactor accident. To show the importance of incorporating the emergency spatial behaviors of the population at risk in radiological emergency preparedness and response plans, this article presents empirical evidence that demonstrates the potential magnitude and geographic extent of spontaneous evacuation in the event of an accident at the Long Island Lighting Company's Shoreham Nuclear Power Station. The results indicate that, on the average, 39% of the population of Long Island is likely to evacuate spontaneously and thus to cast an evacuation shadow extending at least 25 miles beyond the plant. On the basis of these findings, necessary revisions to FEMA's radiological emergency preparedness program are outlined

  10. Teaching case studies on emergency evacuation : final report

    Science.gov (United States)

    2011-02-15

    Through the development of four Harvard Kennedy School case studies, this project explored the policy and institutional dimensions of emergency evacuation planning and implementation in two major metropolitan areas Houston and New Orleans. By pro...

  11. Rhode Island Hurricane Evacuation Study Technical Data Report

    National Research Council Canada - National Science Library

    1995-01-01

    ... evacuation decision-making. To accomplish this, the study provides information on the extent and severity of potential flooding from hurricanes, the associated vulnerable population, capacities of existing public shelters...

  12. Multi-hazard evacuation route and shelter planning for buildings.

    Science.gov (United States)

    2014-06-01

    A bi-level, two-stage, binary stochastic program with equilibrium constraints, and three variants, are presented that : support the planning and design of shelters and exits, along with hallway fortification strategies and associated : evacuation pat...

  13. Coordination of IVI and transit signal priority on transit evacuations.

    Science.gov (United States)

    2011-02-01

    During an emergency evacuation, execution time is always critical to the evacuees who are : transit dependent. Transit Signal Priority (TSP) can speed up the transit services by prioritizing : the approaching bus at a signalized intersection. With th...

  14. Evacuation decision-making at three mile island

    International Nuclear Information System (INIS)

    Zeigler, Donald. J.; Johnson, James. H.

    1987-01-01

    The accident at the Three Mile Island nuclear power plant in 1979 provoked an unanticipated and unprecedented spontaneous evacuation of people living in the area. Following the accident, revised and upgraded emergency preparedness and response regulations were issued by the Nuclear Regulatory Commission (NRC) and the Federal Emergency Management Agency. (FEMA). This includes the assumption that public education and awareness will minimise the tendency of people to evacuate spontaneously from the vicinity of an accident. This assumption is challenged. Results of an empirical test of a casual model of emergency evacuation decision-making are given. This test was devised to aid understanding of the public behaviour at the time of the Three Mile Island incident. The emergency plans for the Sizewell-B reactor are subject to brief critical consideration. It is concluded that evacuation plans need to reflect people's natural inclinations to move away from a nuclear hazard. (UK)

  15. Vesicovaginal fistula complicating uterine evacuation: a case report ...

    African Journals Online (AJOL)

    Vesicovaginal fistula complicating uterine evacuation: a case report. MA Ijaiya, AP Aboyeji, GA Fawole, AAG Jimoh, OO Alabi, AO Olarinoye, OL Akintade, OK Ogah, DNC Nwachukwu, OA Alabi, SA Esuga, ZB Ijaiya ...

  16. Modelling gastric evacuation in gadoids feeding on crustaceans

    DEFF Research Database (Denmark)

    Andersen, Niels Gerner; Chabot, Denis; Couturier, C. S.

    2016-01-01

    A mechanistic, prey surface-dependent model was expanded to describe the course and rate of gastric evacuation in predatory fishes feeding on crustacean prey with robust exoskeletons. This was accomplished by adding a layer of higher resistance to the digestive processes outside the inner softer...... parts of a prey cylinder abstraction and splitting up the prey evacuation into two stages: an initial stage where the exoskeleton is cracked and a second where the prey remains are digested and evacuated. The model was parameterized for crustaceans with different levels of armour fed to Atlantic cod...... and Chionoecetes opilio. In accordance with the apparent intraspecific isometric relationship between exoskeleton mass and total body mass, the model described stage duration and rate of evacuation of the crustacean prey independently of meal and prey sizes. The duration of the first stage increased (0-33 h...

  17. Evacuation emergency response model coupling atmospheric release advisory capability output

    International Nuclear Information System (INIS)

    Rosen, L.C.; Lawver, B.S.; Buckley, D.W.; Finn, S.P.; Swenson, J.B.

    1983-01-01

    A Federal Emergency Management Agency (FEMA) sponsored project to develop a coupled set of models between those of the Lawrence Livermore National Laboratory (LLNL) Atmospheric Release Advisory Capability (ARAC) system and candidate evacuation models is discussed herein. This report describes the ARAC system and discusses the rapid computer code developed and the coupling with ARAC output. The computer code is adapted to the use of color graphics as a means to display and convey the dynamics of an emergency evacuation. The model is applied to a specific case of an emergency evacuation of individuals surrounding the Rancho Seco Nuclear Power Plant, located approximately 25 miles southeast of Sacramento, California. The graphics available to the model user for the Rancho Seco example are displayed and noted in detail. Suggestions for future, potential improvements to the emergency evacuation model are presented

  18. Solar Heating Systems with Evacuated Tubular Solar Collector

    DEFF Research Database (Denmark)

    Qin, Lin; Furbo, Simon

    1998-01-01

    Recently different designed evacuated tubular solar collectors were introduced on the market by different Chinese companies. In the present study, investigations on the performance of four different Chinese evacuated tubular collectors and of solar heating systems using these collectors were...... carried out, employing both laboratory test and theoretical calculations. The collectors were tested in a small solar domestic hot water (SDHW) system in a laboratory test facility under realistic conditions. The yearly thermal performance of solar heating systems with these evacuated tubular collectors......, as well as with normal flat-plate collectors was calculated under Danish weather conditions. It is found that, for small SDHW systems with a combi tank design, an increase of 25% -55% net utilized solar energy can be achieved by using these evacuated tubular collectors instead of normal flat...

  19. Study of evacuation times based on recent accident history

    International Nuclear Information System (INIS)

    Mills, G.S.; Neuhauser, K.S.

    1995-01-01

    A key parameter in the calculation of accident dose-risks by the RADTRAN 4 code is the time assigned for evacuation of the affected area surrounding the accident. Currently, in the interest of assured conservatism, this time is set at 24 hrs. Casual anecdotal evidence has indicated that this value is overly conservative and results in assignment of overly conservative estimates of accident dose-risk. Therefore, a survey of recent truck accidents involving various hazardous materials which required evacuation of surrounding populations reported in various news media was undertaken. Accounts of pertinent scenarios were gleaned from databases citing newspapers and other periodicals, and the local authorities involved in each were contacted to get details of the evacuation including time required. This paper presents the data obtained in the study and the resultant mean evacuation time plus limits and factors influencing specific results together with conclusions regarding the appropriate value to be used in the RADTRAN 4 code

  20. Analysis of community tsunami evacuation time: An overview

    Science.gov (United States)

    Yunarto, Y.; Sari, A. M.

    2018-02-01

    Tsunami in Indonesia is defined as local tsunami due to its occurrences which are within a distance of 200 km from the epicenter of the earthquake. A local tsunami can be caused by an earthquake, landslide, or volcanic eruption. Tsunami arrival time in Indonesia is generally between 10-60 minutes. As the estimated time of the tsunami waves to reach the coast is 30 minutes after the earthquake, the community should go to the vertical or horizontal evacuation in less than 30 minutes. In an evacuation, the city frequently does the evacuation after obtaining official directions from the authorities. Otherwise, they perform an independent evacuation without correct instructions from the authorities. Both of these ways have several strengths and limitations. This study analyzes these methods regarding time as well as the number of people expected to be saved.

  1. The effect of meal size on gastric evacuation in whiting

    DEFF Research Database (Denmark)

    Andersen, Niels Gerner

    1998-01-01

    Gastric evacuation experiments were performed on whiting Merlangius merlangus fed discrete meals of different sizes. Herring Clupea harengus, sandeel Ammodytes tobianus, common goby Pomatoschistus microps, and brown shrimp Crangon crangon were tested as prey. A simple power model to describe...

  2. Empirical study on social groups in pedestrian evacuation dynamics

    Science.gov (United States)

    von Krüchten, Cornelia; Schadschneider, Andreas

    2017-06-01

    Pedestrian crowds often include social groups, i.e. pedestrians that walk together because of social relationships. They show characteristic configurations and influence the dynamics of the entire crowd. In order to investigate the impact of social groups on evacuations we performed an empirical study with pupils. Several evacuation runs with groups of different sizes and different interactions were performed. New group parameters are introduced which allow to describe the dynamics of the groups and the configuration of the group members quantitatively. The analysis shows a possible decrease of evacuation times for large groups due to self-ordering effects. Social groups can be approximated as ellipses that orientate along their direction of motion. Furthermore, explicitly cooperative behaviour among group members leads to a stronger aggregation of group members and an intermittent way of evacuation.

  3. Effect of internal woven roller shade and glazing on the energy and daylighting performances of an office building in the cold climate of Shillong

    International Nuclear Information System (INIS)

    Singh, Ramkishore; Lazarus, I.J.; Kishore, V.V.N.

    2015-01-01

    Highlights: • We simulated a number of glazing and interior roller shade alternatives. • Office room has been simulated for three window-to-wall ratios in a cold climate. • Daylighting and energy performances have been assessed for each alternative. • Maximum energy savings have been estimated in the office with a 30% glazed area. • Energy saving decreases for larger glazed area and fabric transmittance. - Abstract: The energy and visual performances of the façades are defined by many parameters including façade size, properties of glazings and shadings, and their arrangements as well as control strategies. In this study, a number of combinations of internal woven roller shades and four double glazings have been proposed and assessed in integrated manner in order to improve the energy efficiency and visual comfort in new or existing office buildings. Office rooms facing south, east, north and west have been simulated for cold climate, by varying glazed areas and proposed glazing and shading alternatives. Results have been calculated, compared and analyzed in terms of the energy consumptions, energy saving potentials, daylight autonomy, useful daylight illuminance and discomfort glare free time, for each of the combinations. Simulation results show that the choice of glazing and shading alternatives can have substantial impact on energy and visual performances of the office space. Regardless of façade orientation, the maximum energy saving is achieved for a window-to-wall ratio (WWR) of 30%. Saving potential decreases significantly for larger glazed area and for each façade orientation. For all façade orientations and glazed areas (except for 30% WWR in the north wall), a bare low-e coated double glazing (U = 1.616 W/m"2 K, SHGC = 0.209, τ_v = 0.301) is found to be the most energy efficient choice. For 30% north glazing, the energy efficiency can be maximized with a different bare low-e coated double glazing (U = 1.628 W/m"2 K, SHGC = 0.370, τ_v = 0

  4. In vitro analysis of different properties of acrylic resins for ocular prosthesis submitted to accelerated aging with or without photopolymerized glaze

    International Nuclear Information System (INIS)

    Santos, Daniela Micheline dos; Nagay, Bruna Egumi; Freitas da Silva, Emily Vivianne; Bonatto, Liliane da Rocha; Sonego, Mariana Vilela; Moreno, Amália; Rangel, Elidiane Cipriano; Cruz, Nilson Cristino da; Goiato, Marcelo Coelho

    2016-01-01

    The effect of a photopolymerized glaze on different properties of acrylic resin (AR) for ocular prostheses submitted to accelerated aging was investigated. Forty discs were divided into 4 groups: N1 AR without glaze (G1); colorless AR without glaze (G2); N1 AR with glaze (G3); and colorless AR with glaze (G4). All samples were polished with sandpaper (240, 600 and 800-grit). In G1 and G2, a 1200-grit sandpaper was also used. In G3 and G4, samples were coated with MegaSeal glaze. Property analysis of color stability, microhardness, roughness, and surface energy, and assays of atomic force microscopy, scanning electron microscopy, and energy-dispersive spectroscopy were performed before and after the accelerated aging (1008 h). Data were submitted to the ANOVA and Tukey Test (p < 0.05). Groups with glaze exhibited statistically higher color change and roughness after aging. The surface microhardness significantly decreased in groups with glaze and increased in groups without glaze. The surface energy increased after the aging, independent of the polishing procedure. All groups showed an increase of surface irregularities. Photopolymerized glaze is an inadequate surface treatment for AR for ocular prostheses and it affected the color stability, roughness, and microhardness. The accelerated aging interfered negatively with the properties of resins. - Highlights: • We analyzed the influence of polishing on two acrylic resins for ocular prosthesis. • We performed different analyzes of esthetic, mechanical and physical properties. • The glaze is an inadequate surface treatment to ocular prosthesis acrylic resin.

  5. In vitro analysis of different properties of acrylic resins for ocular prosthesis submitted to accelerated aging with or without photopolymerized glaze

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Daniela Micheline dos, E-mail: danielamicheline@foa.unesp.br [Department of Dental Materials and Prosthodontics, Aracatuba Dental School, Sao Paulo State University (UNESP), Aracatuba, Sao Paulo (Brazil); Nagay, Bruna Egumi; Freitas da Silva, Emily Vivianne; Bonatto, Liliane da Rocha; Sonego, Mariana Vilela [Department of Dental Materials and Prosthodontics, Aracatuba Dental School, Sao Paulo State University (UNESP), Aracatuba, Sao Paulo (Brazil); Moreno, Amália [Department of Oral Surgery and Pathology, School of Dentistry, Federal University of Minas Gerais (UFMG), Belo Horizonte, Minas Gerais (Brazil); Rangel, Elidiane Cipriano; Cruz, Nilson Cristino da [Technological Plasma Laboratory (LaPTec), Experimental Campus of Sorocaba, UNESP, Sorocaba, Sao Paulo (Brazil); Goiato, Marcelo Coelho [Department of Dental Materials and Prosthodontics, Aracatuba Dental School, Sao Paulo State University (UNESP), Aracatuba, Sao Paulo (Brazil)

    2016-12-01

    The effect of a photopolymerized glaze on different properties of acrylic resin (AR) for ocular prostheses submitted to accelerated aging was investigated. Forty discs were divided into 4 groups: N1 AR without glaze (G1); colorless AR without glaze (G2); N1 AR with glaze (G3); and colorless AR with glaze (G4). All samples were polished with sandpaper (240, 600 and 800-grit). In G1 and G2, a 1200-grit sandpaper was also used. In G3 and G4, samples were coated with MegaSeal glaze. Property analysis of color stability, microhardness, roughness, and surface energy, and assays of atomic force microscopy, scanning electron microscopy, and energy-dispersive spectroscopy were performed before and after the accelerated aging (1008 h). Data were submitted to the ANOVA and Tukey Test (p < 0.05). Groups with glaze exhibited statistically higher color change and roughness after aging. The surface microhardness significantly decreased in groups with glaze and increased in groups without glaze. The surface energy increased after the aging, independent of the polishing procedure. All groups showed an increase of surface irregularities. Photopolymerized glaze is an inadequate surface treatment for AR for ocular prostheses and it affected the color stability, roughness, and microhardness. The accelerated aging interfered negatively with the properties of resins. - Highlights: • We analyzed the influence of polishing on two acrylic resins for ocular prosthesis. • We performed different analyzes of esthetic, mechanical and physical properties. • The glaze is an inadequate surface treatment to ocular prosthesis acrylic resin.

  6. Study of Evacuation Behavior of Coastal Gulf of Mexico Residents

    OpenAIRE

    Bhattacharjee, Sanjoy; Petrolia, Daniel R.; Hanson, Terrill R.

    2009-01-01

    In this study, we investigate the link between hurricane characteristics, demographics of the Coastal Gulf of Mexico residents, including their household location, and their respective evacuation behavior. Our study is significantly different from the previously made studies on hurricane evacuation behavior in two ways. At first, the research data is collected through recording responses to a series of hypothetical situations which are quite identical to the set of information that people are...

  7. Impact Verification of Aerogel Insulation Paint on Historic Brick Facades

    Science.gov (United States)

    Ganobjak, Michal; Kralova, Eva

    2017-10-01

    Increasing the sustainability of existing buildings is being motivated by reduction of their energy demands. It is the above all the building envelope and its refurbishment by substitution or addition of new materials that makes the opportunity for reduction of energy consumption. A special type of refurbishment is conservation of historical buildings. Preservation of historic buildings permits also application of innovative methods and materials in addition to the original materials if their effects are known and the gained experience ensures their beneficial effect. On the market, there are new materials with addition of silica aerogel in various forms of products. They are also potentially useful in conservation of monuments. However, the effects of aerogel application in these cases are not known. For refurbishment is commercially available additional transparent insulation paint - Nansulate Clear Coat which is containing aerogel and can be used for structured surfaces such as bricks. A series of experiments examined the thermo-physical manifestation of an ultra-thin insulation coating of Nansulate Clear Coat containing silica aerogel on a brick facade. The experiments of active and passive thermography have observed effects of application on the small-scale samples of the brick façade of a protected historical building. Through a series of experiments were measured thermal insulation effect and influence on the aesthetic characteristics such as change in colour and gloss. The treated samples were compared to a reference. Results have shown no thermal-insulating manifestation of the recommended three layers of insulation paint. The three layers recommended by the manufacturer did not significantly affect the appearance of the brick facade. Color and gloss were not significantly changed. Experiments showed the absence of thermal insulation effect of Nansulate transparent triple coating. The thermal insulation effect could likely be reached by more layers of

  8. Preparation and Characterization of a Calcium Carbonate Aerogel

    Directory of Open Access Journals (Sweden)

    Johann Plank

    2009-01-01

    Full Text Available We report on a facile method for the preparation of a calcium carbonate aerogel consisting of aggregated secondary vaterite particles with an approximate average diameter of 50 nm. It was synthesized via a sol-gel process by reacting calcium oxide with carbon dioxide in methanol and subsequent supercritical drying of the alcogel with carbon dioxide. The resulting monolith was opaque, brittle and had overall dimensions of 6×2×1 cm. It was characterized by X-ray powder diffraction, nitrogen adsorption method (BET, and scanning electron microscopy.

  9. Dual effects of pedestrian density on emergency evacuation

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Yi, E-mail: yima23-c@my.cityu.edu.hk [School of Transportation and Logistics, Southwest Jiaotong University, Chengdu (China); Department of Architecture and Civil Engineering, City University of Hong Kong, Kowloon (Hong Kong); Lee, Eric Wai Ming; Yuen, Richard Kwok Kit [Department of Architecture and Civil Engineering, City University of Hong Kong, Kowloon (Hong Kong)

    2017-02-05

    This paper investigates the effect of the pedestrian density in building on the evacuation dynamic with simulation method. In the simulations, both the visibility in building and the exit limit of building are taken into account. The simulation results show that the effect of the pedestrian density in building on the evacuation dynamics is dual. On the one hand, when the visibility in building is very large, the increased pedestrian density plays a negative effect. On the other hand, when the visibility in building is very small, the increased pedestrian density can play a positive effect. The simulation results also show that when both the exit width and visibility are very small, the varying of evacuation time with regard to the pedestrian density is non-monotonous and presents a U-shaped tendency. That is, in this case, too large or too small pedestrian density in building is disadvantageous to the evacuation process. Our findings provide a new insight about the effect of the pedestrian density in building on the evacuation dynamic. - Highlights: • Pedestrian density inside buildings has dual effects on evacuation. • Increased pedestrian density has a negative effect in cases of increased visibility. • Increased pedestrian density has a positive effect in cases of decreased visibility.

  10. Evacuation decision-making at Three Mile Island

    International Nuclear Information System (INIS)

    Zeigler, D.J.; Johnson, J.H. Jr.

    1987-01-01

    During the emergency at the Three Mile Island generating station in the United States, evacuation became a common adaptive response among the local population. The planning for nuclear emergencies in the US has proceeded as if there were no significant differences between nuclear and other types of disasters requiring evacuation. In the United Kingdom, emergency planning for a new generation of pressurized water reactors, about which there is legitimate safety concern, has been influenced not at all by the experience with the Three Mile Island PWR in 1979. The TMI accident has been the US's most serious experience with a nuclear plant accident and therefore is an appropriate analogy for predicting the evacuation response to future nuclear emergencies. In this light, the authors accept the need to develop models that will enable them to predict the magnitude of the evacuation shadow phenomenon around other nuclear power sites and estimate its impact on our plans to remove the threatened population from the hazard zone in the minimum amount of time. Rather than depend on education and information control to stifle evacuation response, the authors believe that evacuation plans need to build on people's natural behavioural inclinations to protect themselves in response to the nuclear hazard

  11. Tsunami evacuation mathematical model for the city of Padang

    International Nuclear Information System (INIS)

    Kusdiantara, R.; Hadianti, R.; Badri Kusuma, M. S.; Soewono, E.

    2012-01-01

    Tsunami is a series of wave trains which travels with high speed on the sea surface. This traveling wave is caused by the displacement of a large volume of water after the occurrence of an underwater earthquake or volcano eruptions. The speed of tsunami decreases when it reaches the sea shore along with the increase of its amplitudes. Two large tsunamis had occurred in the last decades in Indonesia with huge casualties and large damages. Indonesian Tsunami Early Warning System has been installed along the west coast of Sumatra. This early warning system will give about 10-15 minutes to evacuate people from high risk regions to the safe areas. Here in this paper, a mathematical model for Tsunami evacuation is presented with the city of Padang as a study case. In the model, the safe areas are chosen from the existing and selected high rise buildings, low risk region with relatively high altitude and (proposed to be built) a flyover ring road. Each gathering points are located in the radius of approximately 1 km from the ring road. The model is formulated as an optimization problem with the total normalized evacuation time as the objective function. The constraints consist of maximum allowable evacuation time in each route, maximum capacity of each safe area, and the number of people to be evacuated. The optimization problem is solved numerically using linear programming method with Matlab. Numerical results are shown for various evacuation scenarios for the city of Padang.

  12. Dual effects of pedestrian density on emergency evacuation

    International Nuclear Information System (INIS)

    Ma, Yi; Lee, Eric Wai Ming; Yuen, Richard Kwok Kit

    2017-01-01

    This paper investigates the effect of the pedestrian density in building on the evacuation dynamic with simulation method. In the simulations, both the visibility in building and the exit limit of building are taken into account. The simulation results show that the effect of the pedestrian density in building on the evacuation dynamics is dual. On the one hand, when the visibility in building is very large, the increased pedestrian density plays a negative effect. On the other hand, when the visibility in building is very small, the increased pedestrian density can play a positive effect. The simulation results also show that when both the exit width and visibility are very small, the varying of evacuation time with regard to the pedestrian density is non-monotonous and presents a U-shaped tendency. That is, in this case, too large or too small pedestrian density in building is disadvantageous to the evacuation process. Our findings provide a new insight about the effect of the pedestrian density in building on the evacuation dynamic. - Highlights: • Pedestrian density inside buildings has dual effects on evacuation. • Increased pedestrian density has a negative effect in cases of increased visibility. • Increased pedestrian density has a positive effect in cases of decreased visibility.

  13. Multi-objective evacuation routing optimization for toxic cloud releases

    International Nuclear Information System (INIS)

    Gai, Wen-mei; Deng, Yun-feng; Jiang, Zhong-an; Li, Jing; Du, Yan

    2017-01-01

    This paper develops a model for assessing the risks associated with the evacuation process in response to potential chemical accidents, based on which a multi-objective evacuation routing model for toxic cloud releases is proposed taking into account that the travel speed on each arc will be affected by disaster extension. The objectives of the evacuation routing model are to minimize travel time and individual evacuation risk along a path respectively. Two heuristic algorithms are proposed to solve the multi-objective evacuation routing model. Simulation results show the effectiveness and feasibility of the model and algorithms presented in this paper. And, the methodology with appropriate modification is suitable for supporting decisions in assessing emergency route selection in other cases (fires, nuclear accidents). - Highlights: • A model for assessing and visualizing the risks is developed. • A multi-objective evacuation routing model is proposed for toxic cloud releases. • A modified Dijkstra algorithm is designed to obtain an solution of the model. • Two heuristic algorithms have been developed as the optimization tool.

  14. Tsunami evacuation mathematical model for the city of Padang

    Energy Technology Data Exchange (ETDEWEB)

    Kusdiantara, R.; Hadianti, R.; Badri Kusuma, M. S.; Soewono, E. [Department of Mathematics Institut Teknologi Bandung, Bandung 40132 (Indonesia); Department of Civil Engineering Institut Teknologi Bandung, Bandung 40132 (Indonesia); Department of Mathematics Institut Teknologi Bandung, Bandung 40132 (Indonesia)

    2012-05-22

    Tsunami is a series of wave trains which travels with high speed on the sea surface. This traveling wave is caused by the displacement of a large volume of water after the occurrence of an underwater earthquake or volcano eruptions. The speed of tsunami decreases when it reaches the sea shore along with the increase of its amplitudes. Two large tsunamis had occurred in the last decades in Indonesia with huge casualties and large damages. Indonesian Tsunami Early Warning System has been installed along the west coast of Sumatra. This early warning system will give about 10-15 minutes to evacuate people from high risk regions to the safe areas. Here in this paper, a mathematical model for Tsunami evacuation is presented with the city of Padang as a study case. In the model, the safe areas are chosen from the existing and selected high rise buildings, low risk region with relatively high altitude and (proposed to be built) a flyover ring road. Each gathering points are located in the radius of approximately 1 km from the ring road. The model is formulated as an optimization problem with the total normalized evacuation time as the objective function. The constraints consist of maximum allowable evacuation time in each route, maximum capacity of each safe area, and the number of people to be evacuated. The optimization problem is solved numerically using linear programming method with Matlab. Numerical results are shown for various evacuation scenarios for the city of Padang.

  15. Tensile Bond Strength of Metal Bracket Bonding to Glazed Ceramic Surfaces With Different Surface Conditionings

    Directory of Open Access Journals (Sweden)

    M. Imani

    2011-12-01

    Full Text Available Objective: The objective of this study was to compare the tensile bond strength of metal brackets bonding to glazed ceramic surfaces using three various surface treatments.Materials and Methods: Forty two glazed ceramic disks were assigned to three groups. In the first and second groups the specimens were etched with 9.5% hydrofluoric acid (HFA. Subsequently in first group, ceramic primer and adhesive were applied, but in second group a bonding agent alone was used. In third group, specimens were treated with 35% phosphoric acid followed by ceramic primerand adhesive application. Brackets were bonded with light cure composites. The specimens were stored in distilled water in the room temperature for 24 hours and thermocycled 500 times between 5°C and 55°C. The universal testing machine was used to test the tensile bond strength and the adhesive remenant index scores between three groups was evaluated. The data were subjected to one-way ANOVA, Tukey and Kruskal-Wallis tests respectively.Results: The tensile bond strength was 3.69±0.52 MPa forfirst group, 2.69±0.91 MPa for second group and 3.60±0.41 MPa for third group. Group II specimens showed tensile strength values significantly different from other groups (P<0.01.Conclusion: In spite of limitations in laboratory studies it may be concluded that in application of Scotch bond multipurpose plus adhesive, phosphoric acid can be used instead of HFA for bonding brackets to the glazed ceramic restorations with enough tensile bond strength.

  16. Three-dimensional multichannel aerogel of carbon quantum dots for high-performance supercapacitors

    Science.gov (United States)

    Lv, Lingxiao; Fan, Yueqiong; Chen, Qing; Zhao, Yang; Hu, Yue; Zhang, Zhipan; Chen, Nan; Qu, Liangti

    2014-06-01

    A three-dimensional (3D) carbon quantum dot (CQD) aerogel has been prepared by in situ assembling CQDs in the sol-gel polymerization of resorcinol (R) and formaldehyde (F) and subsequently pyrolyzing the formed CQD gel. Compared to the supercapacitor based on the CQD-free aerogel, the supercapacitor fabricated with the CQD aerogel showed 20-fold higher specific capacitance (294.7 F g-1 at the current density of 0.5 A g-1) and an excellent stability over 1000 consecutive charge-discharge cycles.

  17. Dynamic properties of silica aerogels as deduced from specific-heat and thermal-conductivity measurements

    DEFF Research Database (Denmark)

    Bernasconi, A.; Sleator, T.; Posselt, D.

    1992-01-01

    The specific heat C(p) and the thermal conductivity lambda of a series of base-catalyzed silica aerogels have been measured at temperatures between 0.05 and 20 K. The results confirm that the different length-scale regions observed in the aerogel structure are reflected in the dynamic behavior of...... SiO2 are most likely not due to fractal behavior....... the possibility of two spectral dimensions characterizing the fracton modes. Our data imply important differences between the physical mechanisms dominating the low-temperature behavior of aerogels and dense glasses, respectively. From our analysis we also conclude that the low-temperature properties of amorphous...

  18. Robust Vacuum-/Air-Dried Graphene Aerogels and Fast Recoverable Shape-Memory Hybrid Foams.

    Science.gov (United States)

    Li, Chenwei; Qiu, Ling; Zhang, Baoqing; Li, Dan; Liu, Chen-Yang

    2016-02-17

    New graphene aerogels can be fabricated by vacuum/air drying, and because of the mechanical robustness of the graphene aerogels, shape-memory polymer/graphene hybrid foams can be fabricated by a simple infiltration-air-drying-crosslinking method. Due to the superelasticity, high strength, and good electrical conductivity of the as-prepared graphene aerogels, the shape-memory hybrid foams exhibit excellent thermotropical and electrical shape-memory properties, outperforming previously reported shape-memory polymer foams. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Assessment of five control strategies of an adjustable glazing at three different climate zones

    Directory of Open Access Journals (Sweden)

    Volker Ritter

    2015-11-01

    Full Text Available The energy demand for operating modern office spaces is often driven by either the annual heating demand, cooling demand or the demand for electrical lighting. The irradiation of the sun directly and indirectly affects the demand of all three. Consequently, the glazing of higher office buildings is often treated with coating that allows a fixed transmittance. Due to changing exterior conditions and interior needs, a fix-transmittance value is a compromise and most often doesn’t provide optimal thermal and visual conditions. The team in the research project named Fluidglass develops a new glazing in which the transmittance of the glazing can be adjusted. This is possible by colouring a fluid, which is circulated in chambers of the glazing. The concentration of the colorant can be infinitely adjusted. In addition, this window allows collecting heat in the exterior fluid and allows the interior fluid chamber to operate as heating panel. This paper presents a first assessment of different control strategies for adjusting the colorant concentration with a simplified model. The assessed control strategies result in considerably different overall energy demands. Certain control strategies have high potential for reducing the energy demand for heating and cooling depending on the locations (Munich 20–30% , Madrid 50–70% , Dubai 50–60%. However, certain control strategies increase the electricity demand for lighting, which needs to be considered in the further development. In general, control strategies that only consider the solar irradiation are less promising strategies in temperate climate than strategies that also take the interior temperature into account. The results of controls that also respect the thermal comfort based on a Predicted Mean Vote (PMV index can achieve low energy demand, presuming that a deviation from the highest level of comfort is acceptable. At this stage of research, none of the studied control strategies shows to be

  20. Study on the glaze ice accretion of wind turbine with various chord lengths

    Science.gov (United States)

    Liang, Jian; Liu, Maolian; Wang, Ruiqi; Wang, Yuhang

    2018-02-01

    Wind turbine icing often occurs in winter, which changes the aerodynamic characteristics of the blades and reduces the work efficiency of the wind turbine. In this paper, the glaze ice model is established for horizontal-axis wind turbine in 3-D. The model contains the grid generation, two-phase simulation, heat and mass transfer. Results show that smaller wind turbine suffers from more serious icing problem, which reflects on a larger ice thickness. Both the collision efficiency and heat transfer coefficient increase under smaller size condition.

  1. Conditions for industrial production

    DEFF Research Database (Denmark)

    Jensen, Karsten Ingerslev; Schultz, Jørgen Munthe; Brauer, H.

    1996-01-01

    The possibility of an industrial aerogel glazing production is discussed with respect to sample size, sales volume and prices. Different ways of an industrial assembling line is outlined and the total costs of a 1 square meter aerogel glazing is calculated.......The possibility of an industrial aerogel glazing production is discussed with respect to sample size, sales volume and prices. Different ways of an industrial assembling line is outlined and the total costs of a 1 square meter aerogel glazing is calculated....

  2. Study of the composition and viscosity of engobe and glazed from dimension stones wastes for application in red tile

    International Nuclear Information System (INIS)

    Hastenreiter, L.L. G.; Santos, J.C.; Taguchi, S.P.

    2014-01-01

    The dimension stones wastes has some constituents that may be employed in the ceramic. This work is about the production of engobe and glaze for ceramic coating. Chemical characterization of the residue and Clay (XRF) was performed. Several compositions were tested in order to decrease the melting temperature of the glaze to 980°C, enabling to produce the ceramic at 1100°C for 15 to 60 minutes, it presenting more uniform and better technological properties of the surface. The viscosities of some compositions of glaze and engobe were studied, to be applied on the red tile (100x100mm) to obtain the ceramic coating. These were analyzed for resistance to abrasion, according to NBR 13 818/1997 and it was found that the ceramic was classified as PEI 1 and may be used, eg in residential bathrooms and dormitories with no doors to the outside. (author)

  3. Inelastic scattering from liquid 4He in aerogel glass

    International Nuclear Information System (INIS)

    Snow, W.M.; Sokol, P.E.

    1988-01-01

    The physics of liquid and solid 4 He in restricted geometries has motivated a number of interesting experiments. Recent experiments include detailed measurements of the phase diagram for bulk liquid in vycor, showing a suppression of the superfluid transition and elevation of the melting pressure, and measurements of the superfluid fraction in vycor, aerogel, and zerogel glasses near the lambda point, in which critical exponents differ from the pure 4 He values have been observed. Many striking features in several of the experiments on helium in restricted geometries are poorly understood. We have performed inelastic neutron scattering measurements of liquid helium in aerogel glass above and below the superfluid transition for two samples of different porosities. The kinetic energy (KE) of the confined liquid is the same as that of the bulk liquid in the normal phase, but is clearly higher than the bulk values in the superfluid phase. The observed scattering in the superfluid phase is more peaked than in the normal phase: consistent with the presence of a Bose condensate. An estimate of the condensate fraction using a modification of a method due to Sears yields values consistent with those estimated for the bulk liquid. 7 refs., 2 figs., 1 tab

  4. The LHCb RICH silica aerogel performance with LHC data

    CERN Multimedia

    Perego, D L

    2010-01-01

    In the LHCb detector at the Large Hadron Collider, powerful charged particle identification is performed by Ring Imaging Cherenkov (RICH) technology. In order to cover the full geometric acceptance and the wide momentum range (1-100 GeV/c), two detectors with three Cherenkov radiators have been designed and installed. In the medium (10-40 GeV/c) and high (30-100 GeV/c) momentum range, gas radiators are used (C4F10 and CF4 respectively). In the low momentum range (1 to a few GeV/c) pion/kaon/proton separation will be done with photons produced in solid silica aerogel. A set of 16 tiles, with the large transverse dimensions ever (20x20 cm$^2$) and nominal refractive index 1.03 have been produced. The tiles have excellent optical properties and homogeneity of refractive index within the tile of ~1%. The first data collected at LHC are used to understand the behaviour of the RICH: preliminary results will be presented and discussed on the performance of silica aerogel and of the gas radiators C4F10 and CF4.

  5. Mechanical Properties and Brittle Behavior of Silica Aerogels

    Directory of Open Access Journals (Sweden)

    Thierry Woignier

    2015-12-01

    Full Text Available Sets of silica gels: aerogels, xerogels and sintered aerogels, have been studied in the objective to understand the mechanical behavior of these highly porous solids. The mechanical behaviour of gels is described in terms of elastic and brittle materials, like glasses or ceramics. The magnitude of the elastic and rupture modulus is several orders of magnitude lower compared to dense glass. The mechanical behaviours (elastic and brittle are related to the same kinds of gel characteristics: pore volume, silanol content and pore size. Elastic modulus depends strongly on the volume fraction of pores and on the condensation reaction between silanols. Concerning the brittleness features: rupture modulus and toughness, it is shown that pores size plays an important role. Pores can be considered as flaws in the terms of fracture mechanics and the flaw size is related to the pore size. Weibull’s theory is used to show the statistical nature of flaw. Moreover, stress corrosion behaviour is studied as a function of environmental conditions (water and alcoholic atmosphere and temperature.

  6. Social influence on evacuation behavior in real and virtual environments

    Directory of Open Access Journals (Sweden)

    Max Kinateder

    2016-07-01

    Full Text Available Virtual reality (VR is a promising tool to study evacuation behavior as it allows experimentally controlled, safe simulation of otherwise dangerous situations. However, validation studies comparing evacuation behavior in real and virtual environments are still scarce. We compare the decision to evacuate in response to a fire alarm in matched physical and virtual environments. 150 participants were tested individually in a one-trial experiment in one of three conditions. In the Control condition, the fire alarm sounded while the participant performed a bogus perceptual matching task. In the Passive bystander condition, the participant performed the task together with a confederate who ignored the fire alarm. In the Active bystander condition, the confederate left the room when the fire alarm went off. Half of the participants in each condition experienced the scenario in the real laboratory, and the other half in a matched virtual environment with a virtual bystander, presented in a head-mounted display. The active bystander group was more likely to evacuate, and the passive bystander group less likely to evacuate, than the control group. This pattern of social influence was observed in both the real and virtual environments, although the overall response to the virtual alarm was reduced; positive influence was comparable, whereas negative influence was weaker in VR. We found no reliable gender effects for the participant or the bystander. These findings extend the bystander effect to the decision to evacuate, revealing a positive as well as the previous negative social influence. The results support the ecological validity of VR as a research tool to study evacuation behavior in emergency situations, with the caveat that effect sizes may be smaller in VR.

  7. Agent-based Modeling with MATSim for Hazards Evacuation Planning

    Science.gov (United States)

    Jones, J. M.; Ng, P.; Henry, K.; Peters, J.; Wood, N. J.

    2015-12-01

    Hazard evacuation planning requires robust modeling tools and techniques, such as least cost distance or agent-based modeling, to gain an understanding of a community's potential to reach safety before event (e.g. tsunami) arrival. Least cost distance modeling provides a static view of the evacuation landscape with an estimate of travel times to safety from each location in the hazard space. With this information, practitioners can assess a community's overall ability for timely evacuation. More information may be needed if evacuee congestion creates bottlenecks in the flow patterns. Dynamic movement patterns are best explored with agent-based models that simulate movement of and interaction between individual agents as evacuees through the hazard space, reacting to potential congestion areas along the evacuation route. The multi-agent transport simulation model MATSim is an agent-based modeling framework that can be applied to hazard evacuation planning. Developed jointly by universities in Switzerland and Germany, MATSim is open-source software written in Java and freely available for modification or enhancement. We successfully used MATSim to illustrate tsunami evacuation challenges in two island communities in California, USA, that are impacted by limited escape routes. However, working with MATSim's data preparation, simulation, and visualization modules in an integrated development environment requires a significant investment of time to develop the software expertise to link the modules and run a simulation. To facilitate our evacuation research, we packaged the MATSim modules into a single application tailored to the needs of the hazards community. By exposing the modeling parameters of interest to researchers in an intuitive user interface and hiding the software complexities, we bring agent-based modeling closer to practitioners and provide access to the powerful visual and analytic information that this modeling can provide.

  8. Flexible transparent aerogels as window retrofitting films and optical elements with tunable birefringence

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Qingkun; Frazier, Allister W.; Zhao, Xinpeng; De La Cruz, Joshua A.; Hess, Andrew J.; Yang, Ronggui; Smalyukh, Ivan I.

    2018-06-01

    Experimental realization of optically transparent, mechanically robust and flexible aerogels has been a longstanding challenge, which limits their practical applications in energy-saving devices, such as thermally insulating films for enhancing energy efficiency of windows. The poor transparency precluded even hypothetical consideration of the possibility of birefringent aerogels. We develop birefringent and optically isotropic aerogels that combine properties of thermal super-insulation, mechanical robustness and flexibility, and transparency to visible-spectrum light. This unusual combination of physical properties is achieved by combining liquid crystalline self-organization of cellulose nanofibers with polysiloxane cross-linking and control of the nanoscale porosity to form hybrid organic-inorganic mesostructured aerogels. Potential applications of these inexpensive materials range from single pane window retrofitting to smart fabrics.

  9. Preparation and Characterization of Highly Spherical Silica-titania Aerogel Beads with High Surface Area

    Directory of Open Access Journals (Sweden)

    YU Yu-xi

    2017-02-01

    Full Text Available The silica-titania aerogel beads were synthesized through sol-gel reaction followed by supercritical drying, in which TEOS and TBT as co-precursors, EtOH as solvents, HAC and NH3·H2O as catalysts. The as-prepared aerogel beads were characterized by SEM,TEM,XRD,FT-IR,TG-DTA and nitrogen adsorption-desorption. The results indicate that the diameter distribution of beads are between 1-8mm, the average diameter of beads is 3.5mm. The aerogel beads have nanoporous network structure with high specific surface area of 914.5m2/g, and the TiO2 particles are distributed in the aerogel uniformly, which keep the anatase crystal under high temperature.

  10. Structural Modifications of Continuous Aerogel Films for Low-power, High Performance Sensing Capabilities

    Data.gov (United States)

    National Aeronautics and Space Administration — Recent work has found that TiO2 nanorods and nanowires can be grown from a high-surface area, highly porous TiO2 ambiently-dried aerogel structure through varying...

  11. Ultralight Graphene/Carbon Nanotubes Aerogels with Compressibility and Oil Absorption Properties

    Directory of Open Access Journals (Sweden)

    Da Zhao

    2018-04-01

    Full Text Available Graphene aerogels have many advantages, such as low density, high elasticity and strong adsorption. They are considered to be widely applicable in many fields. At present, the most valuable research area aims to find a convenient and effective way to prepare graphene aerogels with excellent properties. In this work graphene/carbon nanotube aerogels are prepared through hydrothermal reduction, freeze-drying and high temperature heat treatment with the blending of graphene oxide and carbon nanotubes. A new reducing agent-ascorbic acid is selected to explore the best preparation process. The prepared aerogels have compression and resilience and oil absorption properties due to the addition of carbon nanotubes as designed.

  12. Ignition capsules with aerogel-supported liquid DT fuel for the National Ignition Facility

    Directory of Open Access Journals (Sweden)

    Ho D.D.-M.

    2013-11-01

    Full Text Available For high repetition-rate fusion power plant applications, capsules with aerogel-supported liquid DT fuel can have much reduced fill time compared to β-layering a solid DT fuel layer. The melting point of liquid DT can be lowered once liquid DT is embedded in an aerogel matrix, and the DT vapor density is consequently closer to the desired density for optimal capsule design requirement. We present design for NIF-scale aerogel-filled capsules based on 1-D and 2-D simulations. An optimal configuration is obtained when the outer radius is increased until the clean fuel fraction is within 65 – 75% at peak velocity. A scan (in ablator and fuel thickness parameter space is used to optimize the capsule configurations. The optimized aerogel-filled capsule has good low-mode robustness and acceptable high-mode mix.

  13. Coupling between Solid 3He on Aerogel and Superfluid 3He in the Low Temperature Limit

    International Nuclear Information System (INIS)

    Bradley, D. I.; Fisher, S. N.; Guenault, A. M.; Haley, R. P.; Pickett, G. R.; Tsepelin, V.; Whitehead, R. C. V.; Skyba, P.

    2006-01-01

    We have cooled liquid 3He contained in a 98% open aerogel sample surrounded by bulk superfluid 3He-B at zero pressure to below 120 μK. The aerogel sample is placed in a quasiparticle blackbody radiator cooled by a Lancaster-style nuclear cooling stage to ∼200 μK. We monitor the temperature of the 3He inside the blackbody radiator using a vibrating wire resonator. We find that reducing the magnetic field on the aerogel sample causes substantial cooling of all the superfluid inside the blackbody radiator. We believe this is due to the demagnetization of the solid 3He layers on the aerogel strands. This system has potential for achieving extremely low temperatures in the confined fluid

  14. Cobalt sulfide aerogel prepared by anion exchange method with enhanced pseudocapacitive and water oxidation performances

    Science.gov (United States)

    Gao, Qiuyue; Shi, Zhenyu; Xue, Kaiming; Ye, Ziran; Hong, Zhanglian; Yu, Xinyao; Zhi, Mingjia

    2018-05-01

    This work introduces the anion exchange method into the sol-gel process for the first time to prepare a metal sulfide aerogel. A porous Co9S8 aerogel with a high surface area (274.2 m2 g‑1) and large pore volume (0.87 cm3 g‑1) has been successfully prepared by exchanging cobalt citrate wet gel in thioacetamide and subsequently drying in supercritical ethanol. Such a Co9S8 aerogel shows enhanced supercapacitive performance and catalytic activity toward oxygen evolution reaction (OER) compared to its oxide aerogel counterpart. High specific capacitance (950 F g‑1 at 1 A g‑1), good rate capability (74.3% capacitance retention from 1 to 20 A g‑1) and low onset overpotential for OER (220 mV) were observed. The results demonstrated here have implications in preparing various sulfide chalcogels.

  15. Readout ASICs and Electronics for the 144-channel HAPDs for the Aerogel RICH at Belle II

    Science.gov (United States)

    Nishida, S.; Adachi, I.; Ikeda, H.; Hara, K.; Iijima, T.; Iwata, S.; Korpar, S.; Križan, P.; Kuroda, E.; Pestotnik, R.; Seljak, A.; Sumiyoshi, T.; Takagaki, H.

    The particle identification (PID) device in the endcap of the Belle detector will be upgraded to a ring imaging Cherenkov counter (RICH) using aerogel as a radiator at the Belle II experiment. We develop the electronics to read out the 70,000 channels of hit information from the 144-channel hybrid avalanche photodetectors (HAPD), of the aerogel RICH detector. A readout ASIC is developed to digitize the HAPD signals, and was used in a beam test with the prototype detector. The performance and plan of the ASIC is reported in this study. We have also designed the readout electronics for the aerogel RICH, which consist of front-end boards with the ASICs merger boards to collect data from the front-end boards. A front-end board that fits in the actual available space for the aerogel RICH electronics was produced.

  16. Organic carbon aerogels from the sol-gel polymerization of phenolic-furfural mixtures

    Science.gov (United States)

    Pekala, R.W.

    1998-04-28

    The sol-gel polymerization of a phenolic-furfural mixture in dilute solution leads to a highly cross-linked network that can be supercritically dried to form a high surface area foam. These porous materials have cell/pore sizes {<=}1000 {angstrom}, and although they are dark brown in color, they can be classified as a new type of aerogel. The phenolic-furfural aerogel can be pyrolyzed in an inert atmosphere at 1050 C to produce carbon aerogels. This new aerogel may be used for thermal insulation, chromatographic packing, water filtration, ion-exchange, and carbon electrodes for energy storage devices, such as batteries and double-layer capacitors. 8 figs.

  17. Organic aerogels from the sol-gel polymerization of phenolic-furfural mixtures

    Science.gov (United States)

    Pekala, R.W.

    1995-12-19

    The sol-gel polymerization of a phenolic-furfural mixture in dilute solution leads to a highly cross-linked network that can be supercritically dried to form a high surface area foam. These porous materials have cell/pore sizes{<=}1000{angstrom}, and although they are dark brown in color, they can be classified as a new type of aerogel. The phenolic-furfural aerogel can be pyrolyzed in an inert atmosphere at 1050 C to produce carbon aerogels. This new aerogel may be used for thermal insulation, chromatographic packing, water filtration, ion-exchange, and carbon electrodes for energy storage devices, such as batteries and double-layer capacitors. 8 figs.

  18. Kinetically controlled synthesis of AuPt bi-metallic aerogels and their enhanced electrocatalytic performances

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Qiurong [School of Mechanical and Materials Engineering; Washington State University; Pullman; USA; Zhu, Chengzhou [School of Mechanical and Materials Engineering; Washington State University; Pullman; USA; Du, Dan [School of Mechanical and Materials Engineering; Washington State University; Pullman; USA; Key Laboratory of Pesticides and Chemical Biology; Bi, Cuixia [Institute of Crystal Materials; Shandong University; Jinan 250100; P. R. China; Xia, Haibing [Institute of Crystal Materials; Shandong University; Jinan 250100; P. R. China; Feng, Shuo [School of Mechanical and Materials Engineering; Washington State University; Pullman; USA; Engelhard, Mark H. [Environmental Molecular Sciences Laboratory; Pacific Northwest National Laboratory; Richland; USA; Lin, Yuehe [School of Mechanical and Materials Engineering; Washington State University; Pullman; USA

    2017-01-01

    Kinetically controlled synthesis of AuPtxbi-metallic hydrogels/aerogels was efficiently achieved for the first timeviatuning the reaction temperature or adding a surfactant.

  19. Method for producing metal oxide aerogels having densities less than 0. 02 g/cc

    Science.gov (United States)

    Tillotson, T.M.; Poco, J.F.; Hrubesh, L.W.; Thomas, I.M.

    1994-01-04

    A two-step method is described for making transparent aerogels which have a density of less than 0.003 g/cm[sup 3] to those with a density of more than 0.8 g/cm[sup 3], by a sol/gel process and supercritical extraction. Condensed metal oxide intermediate made with purified reagents can be diluted to produce stable aerogels with a density of less than 0.02 g/cm[sup 3]. High temperature, direct supercritical extraction of the liquid phase of the gel produces hydrophobic aerogels which are stable at atmospheric moisture conditions. Monolithic, homogeneous silica aerogels with a density of less than 0.02 to higher than 0.8 g/cm[sup 3], with high thermal insulation capacity, improved mechanical strength and good optical transparency, are described. 7 figures.

  20. Data in support of energy performance of double-glazed windows.

    Science.gov (United States)

    Shakouri, Mahmoud; Banihashemi, Saeed

    2016-06-01

    This paper provides the data used in a research project to propose a new simplified windows rating system based on saved annual energy ("Developing an empirical predictive energy-rating model for windows by using Artificial Neural Network" (Shakouri Hassanabadi and Banihashemi Namini, 2012) [1], "Climatic, parametric and non-parametric analysis of energy performance of double-glazed windows in different climates" (Banihashemi et al., 2015) [2]). A full factorial simulation study was conducted to evaluate the performance of 26 different types of windows in a four-story residential building. In order to generalize the results, the selected windows were tested in four climates of cold, tropical, temperate, and hot and arid; and four different main orientations of North, West, South and East. The accompanied datasets include the annual saved cooling and heating energy in different climates and orientations by using the selected windows. Moreover, a complete dataset is provided that includes the specifications of 26 windows, climate data, month, and orientation of the window. This dataset can be used to make predictive models for energy efficiency assessment of double glazed windows.

  1. Innovations for glazing of buildings; Innovationen fuer die Verglasung von Gebaeuden

    Energy Technology Data Exchange (ETDEWEB)

    Wittwer, V. [Fraunhofer-Inst. fuer Solare Energiesysteme, Freiburg (Germany). Abt. Thermische und Optische Systeme

    1998-02-01

    There are two main aspects in the development of new glazing. On the one hand, windows with extremely low thermal conductivity are wanted. On the other hand, solar irradiation should contribute to thermal gains during the heating season. A large number of different coatings and window systems is suited for many different applications. In particular for the prevention of overheating in the summer, there is a huge interest in glazing regulating the irradiation itself without additional mechanical devices. Indeed, innovations have sprung using several of these ideas. (orig.) [Deutsch] Bei der Entwicklung neuer Verglasungen spielen zwei Gesichtspunkte eine hervorragende Rolle. Zum einen ist man an Fenstern mit sehr geringen Waermeverlusten interessiert. Zum anderen soll aber auch die solare Einstrahlung waehrend der Heizperiode zu thermischen Gewinnen beitragen. Die Vielfalt der einsetzbaren Beschichtungen und Fenstersysteme ermoeglicht eine breite Palette von Anwendungsmoeglichkeiten. Insbesondere um Ueberhitzungsprobleme im Sommer auszuschliessen, ist man an Verglasungen interessiert, die die Einstrahlung selber, d.h. ohne mechanische Zusaetze, regeln. Tatsaechlich fuehren hierfuer verschiedene Ansaetze zu Neuentwicklungen. (orig.)

  2. Tensile bond strength of metal bracket bonding to glazed ceramic surfaces with different surface conditionings.

    Science.gov (United States)

    Akhoundi, Ms Ahmad; Kamel, M Rahmati; Hashemi, Sh Mahmood; Imani, M

    2011-01-01

    The objective of this study was to compare the tensile bond strength of metal brackets bonding to glazed ceramic surfaces using three various surface treatments. Forty two glazed ceramic disks were assigned to three groups. In the first and second groups the specimens were etched with 9.5% hydrofluoric acid (HFA). Subsequently in first group, ceramic primer and adhesive were applied, but in second group a bonding agent alone was used. In third group, specimens were treated with 35% phosphoric acid followed by ceramic primer and adhesive application. Brackets were bonded with light cure composites. The specimens were stored in distilled water in the room temperature for 24 hours and thermocycled 500 times between 5°C and 55°C. The universal testing machine was used to test the tensile bond strength and the adhesive remenant index scores between three groups was evaluated. The data were subjected to one-way ANOVA, Tukey and Kruskal-Wallis tests respectively. The tensile bond strength was 3.69±0.52 MPa forfirst group, 2.69±0.91 MPa for second group and 3.60±0.41 MPa for third group. Group II specimens showed tensile strength values significantly different from other groups (Ptensile bond strength.

  3. Glazed pottery of the South-Eastern Crimea from the excavations of the Tsarev settlement

    Directory of Open Access Journals (Sweden)

    Iudin Nikita I.

    2015-09-01

    Full Text Available The article deals with the findings of glazed ceramics produced in the South-Eastern Crimea, and then excavated at the Tsarev settlement. Their typology, chronology and topography are being introduced by the author. On the basis of the 165 analyzed fragments and whole vessels the author suggests a 4-level classification scheme, which includes the production center, functional purpose of the items, morphological characteristics and ornamentation of the vessels. Basic types and variations of vessels’ shapes are being described according to three major chronological periods: 1. Early 1300s, 2. 1330s, 3. The second half of the 14th century. Notably, the earliest findings of ceramics dated by the first two periods were located on the South-Eastern part of the Tsarev settlement. Most of all, its are the bowls on a circular underpan lacking ornamentation and covered with green transparent glazing. Since the second half of the 14th century the vessels from the South-Eastern Crimea had been widely spread on the entire area of the settlement. The assortment of vessels’ shapes used at this time along with jars and bowls, was now widened by aftobes and apothecary amphoras.

  4. Data in support of energy performance of double-glazed windows

    Directory of Open Access Journals (Sweden)

    Mahmoud Shakouri

    2016-06-01

    Full Text Available This paper provides the data used in a research project to propose a new simplified windows rating system based on saved annual energy (“Developing an empirical predictive energy-rating model for windows by using Artificial Neural Network” (Shakouri Hassanabadi and Banihashemi Namini, 2012 [1], “Climatic, parametric and non-parametric analysis of energy performance of double-glazed windows in different climates” (Banihashemi et al., 2015 [2]. A full factorial simulation study was conducted to evaluate the performance of 26 different types of windows in a four-story residential building. In order to generalize the results, the selected windows were tested in four climates of cold, tropical, temperate, and hot and arid; and four different main orientations of North, West, South and East. The accompanied datasets include the annual saved cooling and heating energy in different climates and orientations by using the selected windows. Moreover, a complete dataset is provided that includes the specifications of 26 windows, climate data, month, and orientation of the window. This dataset can be used to make predictive models for energy efficiency assessment of double glazed windows.

  5. Chemical behavior and spectroscopic properties of rare earth borates in glazes

    Energy Technology Data Exchange (ETDEWEB)

    Lezhnina, Marina M., E-mail: marina@fh-muenster.de [Muenster University of Applied Sciences, Department of Chemical Engineering, Stegerwaldstr. 39, 48565 Steinfurt (Germany); Kätker, Heike [Muenster University of Applied Sciences, Department of Chemical Engineering, Stegerwaldstr. 39, 48565 Steinfurt (Germany); Kaiser, Martin [Federal Institute for Materials Research and Testing (BAM), Richard-Willstätter-Straße 11, 12489 Berlin (Germany); Stegemann, Linda [University of Muenster, Physical Institute, Heisenbergstr. 11, 48149 Muenster (Germany); Voss, Eckhard [Wendel GmbH, Am Güterbahnhof 30, 35683 Dillenburg (Germany); Resch-Genger, Ute [Federal Institute for Materials Research and Testing (BAM), Richard-Willstätter-Straße 11, 12489 Berlin (Germany); Strassert, Cristian [University of Muenster, Physical Institute, Heisenbergstr. 11, 48149 Muenster (Germany); Kynast, Ulrich [Muenster University of Applied Sciences, Department of Chemical Engineering, Stegerwaldstr. 39, 48565 Steinfurt (Germany)

    2016-02-15

    Efficient Near UV excited materials (350<λ<400 nm) responding with green line emission are sparse in comparison to higher energy UV excited emitters (λ<350 nm), while corresponding red line emitters are more abundant, albeit typically also restricted to excitation wavelengths below 400 nm. This situation is disadvantageous for several important actual and potential applications. Among these, excitation with high power UV-LEDs and laser diodes are of particular interest. Here we present results on green emitting YBO{sub 3}:Ce, Tb, which can be excited with 370–380 nm radiation at quantum efficiencies of up to 60% and decay times in excess of 2 ms. Moreover, as powderous phosphors typically require stable matrices to be hosted in, we investigated low melting, lead- and fluoride-free glasses for their capability to accommodate the phosphor and yet retain its optical properties. In these, we even observed an increase of the quantum efficiencies of up to 70% at decay times approaching 3 ms. Finally, we characterized the thermal quenching behavior, which showed a clear advantage of the phosphors in glassy matrices. - Highlights: • YBO3:Ce, Tb revisited as a reference material for Near UV excitation. • Absolute quantum yields determined independently at different institutions. • Efficient luminescence from glazing YBO{sub 3}:Ce,Tb with glass forming compositions. • Glaze composites retain or surpass pure phosphor’s optical performance.

  6. Microstructure characteristics of vacuum glazing brazing joints using laser sealing technique

    Science.gov (United States)

    Liu, Sixing; Yang, Zheng; Zhang, Jianfeng; Zhang, Shanwen; Miao, Hong; Zhang, Yanjun; Zhang, Qi

    2018-05-01

    Two pieces of plate glass were brazed into a composite of glazing with a vacuum chamber using PbO-TiO2-SiO2-RxOy powder filler alloys to develop a new type of vacuum glazing. The brazing process was carried out by laser technology. The interface characteristics of laser brazed joints formed between plate glass and solder were investigated using optical microscope, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) techniques. The results show that the inter-diffusion of Pb/Ti/Si/O elements from the sealing solder toward the glass and O/Al/Si elements from the glass toward the solder, resulting in a reaction layer in the brazed joints. The microstructure phases of PbTiO3, AlSiO, SiO2 and PbO in the glass/solder interface were confirmed by XRD analysis. The joining of the sealing solder to the glass was realized by the reaction products like fibrous structures on interface, where the wetting layer can help improve the bonding performance and strength between the sealing solder and the plate glass during the laser brazing process.

  7. A preliminary study on coloring mechanism of Jun copper red glaze

    International Nuclear Information System (INIS)

    Tian Shibing; Liu Yuzhen; Zhang Maolin; Wang Lihua; Wang Cangsui; Xie Yaning

    2009-01-01

    The origin of a red color glazes decorated on the ancient Jun porcelain has been attributed to the presence of combined copper clusters and cuprous oxide, or cuprous oxide alone. For better understanding of the color-forming mechanism, X-ray absorption at the Cu-edge by the red area of a Jun porcelain shard was carried out. By comparing the XANFS spectra of the sample with metal copper and cubic Cu 2 O, we found that the spectra of the red layer of sample were similar to the spectrum combination of 37% Cu 2 O and 63% metal copper,while the spectra from surface of the red spot mainly resembled that of cubic Cu 2 O. The EXAFS results showed that monovalence copper cations were isolated in the glaze matrix, and copper atoms were formed to metallic copper clusters or mutimers dominantly distributed in the inner layer. These can be responsible to the optical properties of the red decoration with the presence of colloidal composition containing copper particles and the Cu + ions. In conclusion, a preliminary non-destructive elemental analysis using synchrotron radiation-induce X-ray fluorescence (SR-XRF) is demonstrated, and mechanism about the formation of the complicated structures is discussed. (authors)

  8. Effect of sodium dodecylbenzene sulfonate on the dispersion stability of ceramic glaze suspension

    Energy Technology Data Exchange (ETDEWEB)

    Satchawan, Suphapan; Naksata, Wimol; Rattanakawin, Chairoj; Thiansem, Sakdiphon; Arqueropanyo, Orn-anong [Chiang Mai University, Chiang Mai (Thailand); Panya, Preecha [Kamphaengphet Rajabhat University, Kamphaengphet (Thailand); Sooksamiti, Ponlayuth [The Office of Primary Industries and Mines Region 3, Chiang Mai (Thailand); Scales, Peter J. [The University of Melbourne, Parkville Victoria (Australia)

    2014-06-15

    Sodium dodecylbenzene sulfonate (SDBS) was used to render the stability of ceramic glaze dispersion which is composed of limestone, feldspar, quartz, kaolin and ferric oxide. The measured zeta potential showed negative values for the systems in deionized water and 0.001 M MgCl{sub 2} media at pH above 2, but a positive value was observed in 0.1M MgCl{sub 2} at pH higher than 6.7. Adsorption of SDBS in aqueous suspensions of ceramic glaze in deionized water and in 0.001 M MgCl{sub 2}, within the concentration range studied, followed both the Langmuir and Freundlich isotherms, but the Freundlich isotherm was more favored. Adsorption of SDBS in 0.1M MgCl{sub 2} corresponded to the Freundlich isotherm. From dispersion stability investigation, SDBS could render the suspension in deionized water and in 0.001 mM MgCl{sub 2} more than in 0.1 mM MgCl{sub 2}.

  9. Two dimensional finite element thermal model of laser surface glazing for H13 tool steel

    Science.gov (United States)

    Kabir, I. R.; Yin, D.; Naher, S.

    2016-10-01

    A two dimensional (2D) transient thermal model with line-heat-source was developed by Finite Element Method (FEM) for laser surface glazing of H13 tool steel using commercial software-ANSYS 15. The geometry of the model was taken as a transverse circular cross-section of cylindrical specimen. Two different power levels (300W, 200W) were used with 0.2mm width of laser beam and 0.15ms exposure time. Temperature distribution, heating and cooling rates, and the dimensions of modified surface were analysed. The maximum temperatures achieved were 2532K (2259°C) and 1592K (1319°C) for laser power 300W and 200W respectively. The maximum cooling rates were 4.2×107 K/s for 300W and 2×107 K/s for 200W. Depths of modified zone increased with increasing laser power. From this analysis, it can be predicted that for 0.2mm beam width and 0.15ms time exposer melting temperature of H13 tool steel is achieved within 200-300W power range of laser beam in laser surface glazing.

  10. Glazed ceramic roof tiles: influence of surface features in the solar reflectance index

    International Nuclear Information System (INIS)

    Bortoli, Leitcia Silva de; Stapait, Camila Cristina; Marinoski, Deivis Luis; Fredel, Marcio Celso; Schabbach, Luciana M.

    2016-01-01

    In this study the influence of surface features of ceramic roof tiles in the solar reflectance index were evaluated. Two glazed ceramic roof tiles (type stoneware) with the same color (ivory) but with different appearance (matte and brilliant) were the focus of the analysis. The Solar Reflectance Index (SRI) of the roofs tiles were determined by the solar reflectance values (UV-VIS-NIR) and emittance, measured in laboratory. The samples showed SRI> 39 in accordance with LEED certification criteria (Leadership in Energy and Environmental Design), contributing to minimizing the Heat Island Effects. Although the matte roof tile shows a slightly higher SRI value (82) than the brilliant one (78), the results for the variables that composes the SRI value (reflectance and emittance) were very similar. Analysis of XRD, SEM and EDS performed on the surfaces of the two roofs indicated for the matte glaze the presence of microcrystals (with barium and zinc) that can contribute to the slightly highest value of SRI. The roughness (optical interferometer white light) and the brightness (brightness meter) of the samples were also measured. (author)

  11. Effect of sodium dodecylbenzene sulfonate on the dispersion stability of ceramic glaze suspension

    International Nuclear Information System (INIS)

    Satchawan, Suphapan; Naksata, Wimol; Rattanakawin, Chairoj; Thiansem, Sakdiphon; Arqueropanyo, Orn-anong; Panya, Preecha; Sooksamiti, Ponlayuth; Scales, Peter J.

    2014-01-01

    Sodium dodecylbenzene sulfonate (SDBS) was used to render the stability of ceramic glaze dispersion which is composed of limestone, feldspar, quartz, kaolin and ferric oxide. The measured zeta potential showed negative values for the systems in deionized water and 0.001 M MgCl 2 media at pH above 2, but a positive value was observed in 0.1M MgCl 2 at pH higher than 6.7. Adsorption of SDBS in aqueous suspensions of ceramic glaze in deionized water and in 0.001 M MgCl 2 , within the concentration range studied, followed both the Langmuir and Freundlich isotherms, but the Freundlich isotherm was more favored. Adsorption of SDBS in 0.1M MgCl 2 corresponded to the Freundlich isotherm. From dispersion stability investigation, SDBS could render the suspension in deionized water and in 0.001 mM MgCl 2 more than in 0.1 mM MgCl 2

  12. SYNTHESIS AND CHARACTERIZATION OF CELLULOSE BASED BIO-POLYMER AEROGEL ISOLATED FROM WASTE OF BLUEBERRY TREE (VACCINIUM MYRTILLUS

    Directory of Open Access Journals (Sweden)

    Mehmet KAYA

    2016-09-01

    Full Text Available Cellulose aerogel (CA has highly porous structure, environmentally friendly, thermally stable and flame retardant properties. These properties in material worlds have attracted large interest as a potentially industrial material. In this paper, cellulose aerogel with flame retardant was produced from pruned branches and bushes of blueberries wastes (PBBW. Firstly, cellulose raw material these wastes was obtained and then, cellulose aerogel via freeze-drying, followed by cellulose hydrogel production. Our reports showed that three dimensionally network aerogel structure prepared from NaOH/Urea as scaffold solution. The present cellulose aerogel has excellent flame retardancy, which can extinguish within 140 s. By the way, it was inferred thermal stability performance of cellulose aerogel could be efficient potential thermal insulating material. Besides, this process are sustainable, easily available at low cost and suitable for industrial applications.

  13. Solar Energy Gain and Space-Heating Energy Supply Analyses for Solid-Wall Dwelling Retrofitted with the Experimentally Achievable U-value of Novel Triple Vacuum Glazing

    Directory of Open Access Journals (Sweden)

    Saim Memon

    2017-06-01

    Full Text Available A considerable effort is devoted to devising retrofit solutions for reducing space-heating energy in the domestic sector. Existing UK solid-wall dwellings, which have both heritage values and historic fabric, are being improved but they tend to have meagre thermal performance, partly, due to the heat-loss through glazings. This paper takes comparative analyses approach to envisage space-heating supply required in order to maintain thermal comfort temperatures and attainable solar energy gains to households with the retrofit of an experimentally achievable thermal performance of the fabricated sample of triple vacuum glazing to a UK solid-wall dwelling. 3D dynamic thermal models (timely regimes of heating, occupancy, ventilation and internal heat gains of an externally-insulated solid-wall detached dwelling with a range of existing glazing types along with triple vacuum glazings are modelled. A dramatic decrease of space-heating load and moderate increase of solar gains are resulted with the dwelling of newly achievable triple vacuum glazings (having centre-of-pane U-value of 0.33 Wm-2K-1 compared to conventional glazing types. The space-heating annual cost of single glazed dwellings was minimised to 15.31% (≈USD 90.7 with the retrofit of triple-vacuum glazings. An influence of total heat-loss through the fabric of solid-wall dwelling was analysed with steady-state calculations which indicates a fall of 10.23 % with triple vacuum glazings compared to single glazings.

  14. From Green Aerogels to Porous Graphite by Emulsion Gelation of Acrylonitrile

    Science.gov (United States)

    2012-01-01

    interparticle covalent bridging in the mechanical properties of aerogels,30 we have opted for a bottom-up process, whereas PAN aerogels are...series that employs the hanging pendant drop method, and data were analyzed using the Young−Laplace equation through the instrument software. Elemental...that the layer of the surfactant prevents intimate contact and efficient covalent bridging between the skeletal nanoparticles. Overall, our ability to

  15. Adsorption and desorption of cationic malachite green dye on cellulose nanofibril aerogels.

    Science.gov (United States)

    Jiang, Feng; Dinh, Darren M; Hsieh, You-Lo

    2017-10-01

    Ultra-light aerogels have been assembled from cellulose nanofibrils into hierarchically macroporous (several hundred μm) honeycomb cellular structure surrounded with mesoporous (8-60nm) thin walls. The high specific surface (193m 2 /g) and surface carboxyl content (1.29mmol/g) of these aerogels were demonstrated to be highly capable of removing cationic malachite green (MG) dye from aqueous media. The rapid MG adsorption was driven by electrostatic interactions and followed a pseudo-second-order adsorption kinetic and monolayer Langmuir adsorption isotherm. At a low 1:5mg/mL aerogel/MG ratio, both initial MG adsorption rate (2.3-59.8mgg -1 min -1 ) and equilibrium adsorption capacity (53.0-203.7mgg -1 ) increased with increasing initial MG concentrations from 10 to 200mg/L, reaching a maximum adsorption of 212.7mgg -1 . The excellent dye removal efficiency was demonstrated by complete MG removal through four repetitive adsorptions at a low 1:5mg/mL aerogel/MG ratio and 10mg/L dye concentration as well as 92% MG adsorption in a single batch at one order of magnitude higher10:5mg/mL aerogel/MG ratio and 100mg/L dye concentration. The adsorbed MG in aerogels could be desorbed in aqueous media by increasing ionic strength, demonstrating facile recovery of both dye and aerogel as well as the robust capability of this aerogel for repetitive applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Combining aerogels with honeycombs – a new stiff and flexible superinsulation

    OpenAIRE

    Schwan, Marina; Ratke, Lorenz; Milow, Barbara

    2014-01-01

    Saving energy is the most important issue in the 21st century. New high qualitative thermal insulation materials are of critical importance to energy-efficient building design, transportation and aircraft industry. We propose to combine aramid honeycombs with aerogels to manufacture such new types of advanced insulation materials. Aramid honeycombs produced from aramid fibers by the expansion method possess extremely high stiffness-to-weight ratio and are heat-resisting up to 550°C. Aerogels ...

  17. Preliminary study of silica aerogel as a gas-equivalent material in ionization chambers

    Science.gov (United States)

    Caresana, M.; Zorloni, G.

    2017-12-01

    Since about two decades, a renewed interest on aerogels has risen. These peculiar materials show fairly unique properties. Thus, they are under investigation for both scientific and commercial purposes and new optimized production processes are studied. In this work, the possibility of using aerogel in the field of radiation detection is explored. The idea is to substitute the gas filling in a ionization chamber with the aerogel. The material possesses a density about 100 times greater than ambient pressure air. Where as the open-pore structure should allow the charge carriers to move freely. Small hydrophobic silica aerogel samples were studied. A custom ionization chamber, capable of working both with aerogel or in the classic gas set up, was built. The response of the chamber in current mode was investigated using an X-ray tube. The results obtained showed, under proper conditions, an enhancement of about 60 times of the current signal in the aerogel configuration with respect to the classic gas one. Moreover, some unusual behaviours were observed, i.e. time inertia of the signal and super-/sub-linear current response with respect to the dose rate. While testing high electric fields, aerogel configuration seemed to enhance the Townsend's effects. In order to represent the observed trends, a trapping-detrapping model is proposed, which is capable to predict semi-empirically the steady state currents measured. The time evolution of the signal is semi-quantitatively represented by the same model. The coefficients estimated by the fits are in agreement with similar trapping problems in the literature. In particular, a direct comparison between the benchmark of the FET silica gates and aerogel case endorses the idea that the same type of phenomenon occurs in the studied case.

  18. Sprayable Aerogel Bead Compositions With High Shear Flow Resistance and High Thermal Insulation Value

    Science.gov (United States)

    Ou, Danny; Trifu, Roxana; Caggiano, Gregory

    2013-01-01

    A sprayable aerogel insulation has been developed that has good mechanical integrity and lower thermal conductivity than incumbent polyurethane spray-on foam insulation, at similar or lower areal densities, to prevent insulation cracking and debonding in an effort to eliminate the generation of inflight debris. This new, lightweight aerogel under bead form can be used as insulation in various thermal management systems that require low mass and volume, such as cryogenic storage tanks, pipelines, space platforms, and launch vehicles.

  19. Oxidation-mediated chitosan as additives for creation of chitosan aerogels with diverse three-dimensional interconnected skeletons

    International Nuclear Information System (INIS)

    Zhang, Sizhao; Feng, Jian; Feng, Junzong; Jiang, Yonggang

    2017-01-01

    Highlights: • A new synthetic method for controlling morphology of chitosan aerogels is proposed. • Chitosan aerogels with nanoflake-like and nanofiber-like were prepared. • Textures of chitosan aerogels are strongly dependent upon the oxidation pattern. - Abstract: Naturally occurring polymer-based aerogels have myriad practical utilizations due to environmentally benign and fruitful resources. However, engineering morphology-controllable biomass aerogels still represents a great challenge. Here we present a facile solution to synthesize chitosan aerogels having distinguished textures by reacting oxidized chitosan with formaldehyde and chitosan sol. In more detail, chitosan was chemically oxidized using two types of oxidation agents such as ammonium persulphate (SPD) and sodium periodate (APS) to obtain corresponding oxidized chitosan, subsequently cross-linked with chitosan solution containing formaldehyde to harvest SPD-oxidized chitosan aerogels (SCAs) and APS-SPD-oxidized ones (ASCAs) after aging, solvent exchange and supercritical drying processes. We found that the morphologies of as-prepared chitosan aerogels are strongly dependent upon the oxidation pattern towards chitosan. The structural textures of SCAs and ASCAs appear nanoflake-like and nanofiber-like structures, which may be related to spatial freedom of active groups located in chitosan. Selected area electron diffraction analysis reveals that the crystalline properties of chitosan aerogels generally appear the serious deterioration comparing to raw chitosan owing to their interconnected skeletal structure formation. The occurrence of characteristic groups displays cross-linked chain construction by using chemical state measurements such as FT-IR and XPS. Further, a plausible mechanism for controlling morphology of chitosan aerogels is also established. This new family of method for creation of chitosan aerogels may open up a perspective for biomass aerogels with controllable textures.

  20. Oxidation-mediated chitosan as additives for creation of chitosan aerogels with diverse three-dimensional interconnected skeletons

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Sizhao, E-mail: bule-soul@hotmail.com; Feng, Jian, E-mail: fengj@nudt.edu.cn; Feng, Junzong; Jiang, Yonggang

    2017-02-28

    Highlights: • A new synthetic method for controlling morphology of chitosan aerogels is proposed. • Chitosan aerogels with nanoflake-like and nanofiber-like were prepared. • Textures of chitosan aerogels are strongly dependent upon the oxidation pattern. - Abstract: Naturally occurring polymer-based aerogels have myriad practical utilizations due to environmentally benign and fruitful resources. However, engineering morphology-controllable biomass aerogels still represents a great challenge. Here we present a facile solution to synthesize chitosan aerogels having distinguished textures by reacting oxidized chitosan with formaldehyde and chitosan sol. In more detail, chitosan was chemically oxidized using two types of oxidation agents such as ammonium persulphate (SPD) and sodium periodate (APS) to obtain corresponding oxidized chitosan, subsequently cross-linked with chitosan solution containing formaldehyde to harvest SPD-oxidized chitosan aerogels (SCAs) and APS-SPD-oxidized ones (ASCAs) after aging, solvent exchange and supercritical drying processes. We found that the morphologies of as-prepared chitosan aerogels are strongly dependent upon the oxidation pattern towards chitosan. The structural textures of SCAs and ASCAs appear nanoflake-like and nanofiber-like structures, which may be related to spatial freedom of active groups located in chitosan. Selected area electron diffraction analysis reveals that the crystalline properties of chitosan aerogels generally appear the serious deterioration comparing to raw chitosan owing to their interconnected skeletal structure formation. The occurrence of characteristic groups displays cross-linked chain construction by using chemical state measurements such as FT-IR and XPS. Further, a plausible mechanism for controlling morphology of chitosan aerogels is also established. This new family of method for creation of chitosan aerogels may open up a perspective for biomass aerogels with controllable textures.

  1. Resident perception of volcanic hazards and evacuation procedures

    Directory of Open Access Journals (Sweden)

    D. K. Bird

    2009-02-01

    Full Text Available Katla volcano, located beneath the Mýrdalsjökull ice cap in southern Iceland, is capable of producing catastrophic jökulhlaup. The Icelandic Civil Protection (ICP, in conjunction with scientists, local police and emergency managers, developed mitigation strategies for possible jökulhlaup produced during future Katla eruptions. These strategies were tested during a full-scale evacuation exercise in March 2006. A positive public response during a volcanic crisis not only depends upon the public's knowledge of the evacuation plan but also their knowledge and perception of the possible hazards. To improve the effectiveness of residents' compliance with warning and evacuation messages it is important that emergency management officials understand how the public interpret their situation in relation to volcanic hazards and their potential response during a crisis and apply this information to the ongoing development of risk mitigation strategies. We adopted a mixed methods approach in order to gain a broad understanding of residents' knowledge and perception of the Katla volcano in general, jökulhlaup hazards specifically and the regional emergency evacuation plan. This entailed field observations during the major evacuation exercise, interviews with key emergency management officials and questionnaire survey interviews with local residents. Our survey shows that despite living within the hazard zone, many residents do not perceive that their homes could be affected by a jökulhlaup, and many participants who perceive that their homes are safe, stated that they would not evacuate if an evacuation warning was issued. Alarmingly, most participants did not receive an evacuation message during the exercise. However, the majority of participants who took part in the exercise were positive about its implementation. This assessment of resident knowledge and perception of volcanic hazards and the evacuation plan is the first of its kind in

  2. A Simple Evacuation Modeling and Simulation Tool for First Responders

    Energy Technology Data Exchange (ETDEWEB)

    Koch, Daniel B [ORNL; Payne, Patricia W [ORNL

    2015-01-01

    Although modeling and simulation of mass evacuations during a natural or man-made disaster is an on-going and vigorous area of study, tool adoption by front-line first responders is uneven. Some of the factors that account for this situation include cost and complexity of the software. For several years, Oak Ridge National Laboratory has been actively developing the free Incident Management Preparedness and Coordination Toolkit (IMPACT) to address these issues. One of the components of IMPACT is a multi-agent simulation module for area-based and path-based evacuations. The user interface is designed so that anyone familiar with typical computer drawing tools can quickly author a geospatially-correct evacuation visualization suitable for table-top exercises. Since IMPACT is designed for use in the field where network communications may not be available, quick on-site evacuation alternatives can be evaluated to keep pace with a fluid threat situation. Realism is enhanced by incorporating collision avoidance into the simulation. Statistics are gathered as the simulation unfolds, including most importantly time-to-evacuate, to help first responders choose the best course of action.

  3. Dual effects of pedestrian density on emergency evacuation

    Science.gov (United States)

    Ma, Yi; Lee, Eric Wai Ming; Yuen, Richard Kwok Kit

    2017-02-01

    This paper investigates the effect of the pedestrian density in building on the evacuation dynamic with simulation method. In the simulations, both the visibility in building and the exit limit of building are taken into account. The simulation results show that the effect of the pedestrian density in building on the evacuation dynamics is dual. On the one hand, when the visibility in building is very large, the increased pedestrian density plays a negative effect. On the other hand, when the visibility in building is very small, the increased pedestrian density can play a positive effect. The simulation results also show that when both the exit width and visibility are very small, the varying of evacuation time with regard to the pedestrian density is non-monotonous and presents a U-shaped tendency. That is, in this case, too large or too small pedestrian density in building is disadvantageous to the evacuation process. Our findings provide a new insight about the effect of the pedestrian density in building on the evacuation dynamic.

  4. Pedestrian evacuation at the subway station under fire

    Science.gov (United States)

    Xiao-Xia, Yang; Hai-Rong, Dong; Xiu-Ming, Yao; Xu-Bin, Sun

    2016-04-01

    With the development of urban rail transit, ensuring the safe evacuation of pedestrians at subway stations has become an important issue in the case of an emergency such as a fire. This paper chooses the platform of line 4 at the Beijing Xuanwumen subway station to study the emergency evacuation process under fire. Based on the established platform, effects of the fire dynamics, different initial pedestrian densities, and positions of fire on evacuation are investigated. According to simulation results, it is found that the fire increases the air temperature and the smoke density, and decreases pedestrians’ visibility and walking velocity. Also, there is a critical initial density at the platform if achieving a safe evacuation within the required 6 minutes. Furthermore, different positions of fire set in this paper have little difference on crowd evacuation if the fire is not large enough. The suggestions provided in this paper are helpful for the subway operators to prevent major casualties. Project supported by the National Natural Science Foundation of China (Grant Nos. 61322307 and 61233001).

  5. Fluid Line Evacuation and Freezing Experiments for Digital Radiator Concept

    Science.gov (United States)

    Berisford, Daniel F.; Birur, Gajanana C.; Miller, Jennifer R.; Sunada, Eric T.; Ganapathi, Gani B.; Stephan, Ryan; Johnson, Mark

    2011-01-01

    The digital radiator technology is one of three variable heat rejection technologies being investigated for future human-rated NASA missions. The digital radiator concept is based on a mechanically pumped fluid loop with parallel tubes carrying coolant to reject heat from the radiator surface. A series of valves actuate to start and stop fluid flow to di erent combinations of tubes, in order to vary the heat rejection capability of the radiator by a factor of 10 or more. When the flow in a particular leg is stopped, the fluid temperature drops and the fluid can freeze, causing damage or preventing flow from restarting. For this reason, the liquid in a stopped leg must be partially or fully evacuated upon shutdown. One of the challenges facing fluid evacuation from closed tubes arises from the vapor generated during pumping to low pressure, which can cause pump cavitation and incomplete evacuation. Here we present a series of laboratory experiments demonstrating fluid evacuation techniques to overcome these challenges by applying heat and pumping to partial vacuum. Also presented are results from qualitative testing of the freezing characteristics of several different candidate fluids, which demonstrate significant di erences in freezing properties, and give insight to the evacuation process.

  6. Aerogel Cherenkov detector for characterizing the intense flash x-ray source, Cygnus, spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y., E-mail: yhkim@lanl.gov; Herrmann, H. W.; McEvoy, A. M.; Young, C. S.; Hamilton, C. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Schwellenbach, D. D.; Malone, R. M.; Kaufman, M. I.; Smith, A. S. [National Security Technologies, LLC, Los Alamos, New Mexico 87544 (United States)

    2016-11-15

    An aerogel Cherenkov detector is proposed to measure the X-ray energy spectrum from the Cygnus—intense flash X-ray source operated at the Nevada National Security Site. An array of aerogels set at a variety of thresholds between 1 and 3 MeV will be adequate to map out the bremsstrahlung X-ray production of the Cygnus, where the maximum energy of the spectrum is normally around 2.5 MeV. In addition to the Cherenkov radiation from aerogels, one possible competing light-production mechanism is optical transition radiation (OTR), which may be significant in aerogels due to the large number of transitions from SiO{sub 2} clusters to vacuum voids. To examine whether OTR is a problem, four aerogel samples were tested using a mono-energetic electron beam (varied in the range of 1–3 MeV) at NSTec Los Alamos Operations. It was demonstrated that aerogels can be used as a Cherenkov medium, where the rate of the light production is about two orders magnitude higher when the electron beam energy is above threshold.

  7. Freeze-Casting Produces a Graphene Oxide Aerogel with a Radial and Centrosymmetric Structure.

    Science.gov (United States)

    Wang, Chunhui; Chen, Xiong; Wang, Bin; Huang, Ming; Wang, Bo; Jiang, Yi; Ruoff, Rodney S

    2018-05-14

    We report the assembly of graphene oxide (G-O) building blocks into a vertical and radially aligned structure by a bidirectional freeze-casting approach. The crystallization of water to ice assembles the G-O sheets into a structure, a G-O aerogel whose local structure mimics turbine blades. The centimeter-scale radiating structure in this aerogel has many channels whose width increases with distance from the center. This was achieved by controlling the formation of the ice crystals in the aqueous G-O dispersion that grew radially in the shape of lamellae during freezing. Because the shape and size of ice crystals is influenced by the G-O sheets, different additives (ethanol, cellulose nanofibers, and chitosan) that can form hydrogen bonds with H 2 O were tested and found to affect the interaction between the G-O and formation of ice crystals, producing ice crystals with different shapes. A G-O/chitosan aerogel with a spiral pattern was also obtained. After chemical reduction of G-O, our aerogel exhibited elasticity and absorption capacity superior to that of graphene aerogels with "traditional" pore structures made by conventional freeze-casting. This methodology can be expanded to many other configurations and should widen the use of G-O (and reduced G-O and "graphenic") aerogels.

  8. Synthesis and Characterization of Fibre Reinforced Silica Aerogel Blankets for Thermal Protection

    Directory of Open Access Journals (Sweden)

    S. Chakraborty

    2016-01-01

    Full Text Available Using tetraethoxysilane (TEOS as the source of silica, fibre reinforced silica aerogels were synthesized via fast ambient pressure drying using methanol (MeOH, trimethylchlorosilane (TMCS, ammonium fluoride (NH4F, and hexane. The molar ratio of TEOS/MeOH/(COOH2/NH4F was kept constant at 1 : 38 : 3.73 × 10−5 : 0.023 and the gel was allowed to form inside the highly porous meta-aramid fibrous batting. The wet gel surface was chemically modified (silylation process using various concentrations of TMCS in hexane in the range of 1 to 20% by volume. The fibre reinforced silica aerogel blanket was obtained subsequently through atmospheric pressure drying. The aerogel blanket samples were characterized by density, thermal conductivity, hydrophobicity (contact angle, and Scanning Electron Microscopy. The radiant heat resistance of the aerogel blankets was examined and compared with nonaerogel blankets. It has been observed that, compared to the ordinary nonaerogel blankets, the aerogel blankets showed a 58% increase in the estimated burn injury time and thus ensure a much better protection from heat and fire hazards. The effect of varying the concentration of TMCS on the estimated protection time has been examined. The improved thermal stability and the superior thermal insulation of the flexible aerogel blankets lead to applications being used for occupations that involve exposure to hazards of thermal radiation.

  9. Preparation of lignin-based carbon aerogels as biomaterials for nano-supercapacitor

    Science.gov (United States)

    Yang, Bong Suk; Kang, Kyu-Young; Jeong, Myung-Joon

    2017-10-01

    Kraft and organosolv lignins, generally produced in chemical pulping and bio-refinery processes of lignocellulosic biomass, were used to prepare lignin-based carbon aerogels for supercapacitors as raw materials. The difference between lignins and lignin-based aerogels were compared by analyzing physical and chemical properties, including molecular weight, polydispersity, and reactivity with formaldehyde. Also, density, shrinkage, Brunauer-Emmett-Teller (BET) surface area and scanning electron microscope (SEM) images of the lignin-based aerogel were investigated. Kraft lignin consisting of coniferyl alcohol (G) and p-coumaryl alcohol (H) increased the reactivity of formaldehyde, formed a hydrogel well (porosity > 0.45), and specific surface area higher than organosolv lignin. In the case of kraft lignin, there were irregular changes such as oxidation and condensation in the pulping process. However, reaction sites with aromatic rings in lignin impacted the production of aerogel and required a long gelation period. The molecular weight of lignin influences the gelation time in producing lignin-based aerogel, and lignin composition affects the BET surface area and pore structures of the lignin-based carbon aerogels.

  10. Transparent, Superflexible Doubly Cross-Linked Polyvinylpolymethylsiloxane Aerogel Superinsulators via Ambient Pressure Drying.

    Science.gov (United States)

    Zu, Guoqing; Shimizu, Taiyo; Kanamori, Kazuyoshi; Zhu, Yang; Maeno, Ayaka; Kaji, Hironori; Shen, Jun; Nakanishi, Kazuki

    2018-01-23

    Aerogels have many attractive properties but are usually costly and mechanically brittle, which always limit their practical applications. While many efforts have been made to reinforce the aerogels, most of the reinforcement efforts sacrifice the transparency or superinsulating properties. Here we report superflexible polyvinylpolymethylsiloxane, (CH 2 CH(Si(CH 3 )O 2/2 )) n , aerogels that are facilely prepared from a single precursor vinylmethyldimethoxysilane or vinylmethyldiethoxysilane without organic cross-linkers. The method is based on consecutive processes involving radical polymerization and hydrolytic polycondensation, followed by ultralow-cost, highly scalable, ambient-pressure drying directly from alcohol as a drying medium without any modification or additional solvent exchange. The resulting aerogels and xerogels show a homogeneous, tunable, highly porous, doubly cross-linked nanostructure with the elastic polymethylsiloxane network cross-linked with flexible hydrocarbon chains. An outstanding combination of ultralow cost, high scalability, uniform pore size, high surface area, high transparency, high hydrophobicity, excellent machinability, superflexibility in compression, superflexibility in bending, and superinsulating properties has been achieved in a single aerogel or xerogel. This study represents a significant progress of porous materials and makes the practical applications of transparent flexible aerogel-based superinsulators realistic.

  11. Capillary Condensation of Liquid 4He in Aerogel on Cooling Through λ Point

    International Nuclear Information System (INIS)

    Miyashita, W.; Yoneyama, K.; Kato, H.; Nomura, R.; Okuda, Y.

    2006-01-01

    Capillary condensation of liquid 4He in silica aerogel with a 90% porosity was investigated visually. The initial condition of the experiment was such that liquid 4He was present in the sample cell but not in the aerogel. This situation was realized by introducing the liquid into the cell at a fast rate to avoid liquefaction in the aerogel. The free surface of the liquid rose up in the cell with filling and eventually reached the bottom of the aerogel. Then, the aerogel absorbed the liquid by capillary condensation. The height of the liquid in the aerogel rose with time t roughly as t1/2 in the normal fluid phase. This behavior was consistent with the Washburn model. When the system was cooled through the λ point during the condensation, the liquid height started to rise faster in the superfluid phase with a constant velocity of about 0.3 mm/sec. The dynamics of capillary condensation was strongly dependent on whether the liquid 4He was in the normal or the superfluid phase

  12. Transparent Ethenylene-Bridged Polymethylsiloxane Aerogels: Mechanical Flexibility and Strength and Availability for Addition Reaction.

    Science.gov (United States)

    Shimizu, Taiyo; Kanamori, Kazuyoshi; Maeno, Ayaka; Kaji, Hironori; Doherty, Cara M; Nakanishi, Kazuki

    2017-05-09

    Transparent, low-density ethenylene-bridged polymethylsiloxane [Ethe-BPMS, O 2/2 (CH 3 )Si-CH═CH-Si(CH 3 )O 2/2 ] aerogels from 1,2-bis(methyldiethoxysilyl)ethene have successfully been synthesized via a sol-gel process. A two-step sol-gel process composed of hydrolysis under acidic conditions and polycondensation under basic conditions in a liquid surfactant produces a homogeneous pore structure based on cross-linked nanosized colloidal particles. Visible-light transmittance of the aerogels varies with the concentration of the base catalyst and reaches as high as 87% (at a wavelength of 550 nm for a 10 mm thick sample). Gelation and aging temperature strongly affect the deformation behavior of the resultant aerogels against uniaxial compression, and the obtained aerogels prepared at 80 °C show high elasticity after being unloaded. This highly resilient behavior is primarily derived from the rigidity of ethenylene groups, which is confirmed by a comparison with other aerogels with similar molecular structures, ethylene-bridged polymethylsiloxane and polymethylsilsesquioxane. Applicability of the addition reaction using a Diels-Alder reaction of benzocyclobutene has also been investigated, revealing that a successful addition takes place on the ethenylene linkings, which is verified using Raman and solid-state NMR spectroscopies. Insights into the effect of molecular structure on mechanical properties and the availability of surface functionalization provided in this study are important for realizing transparent aerogels with the desired functionality.

  13. A synthesis method for cobalt doped carbon aerogels with high surface area and their hydrogen storage properties

    Energy Technology Data Exchange (ETDEWEB)

    Tian, H.Y.; Buckley, C.E. [Department of Imaging and Applied Physics, Curtin University of Technology, GPO Box U 1987, Perth 6845, WA (Australia); CSIRO National Hydrogen Materials Alliance, CSIRO Energy Centre, 10 Murray Dwyer Circuit, Steel River Estate, Mayfield West, NSW 2304 (Australia); Sheppard, D.A.; Paskevicius, M. [Department of Imaging and Applied Physics, Curtin University of Technology, GPO Box U 1987, Perth 6845, WA (Australia); Hanna, N. [CSIRO Process Science and Engineering, Waterford, WA (Australia)

    2010-12-15

    Carbon aerogels doped with nanoscaled Co particles were prepared by first coating activated carbon aerogels using a wet-thin layer coating process. The resulting metal-doped carbon aerogels had a higher surface area ({proportional_to}1667 m{sup 2} g{sup -1}) and larger micropore volume ({proportional_to}0.6 cm{sup 3} g{sup -1}) than metal-doped carbon aerogels synthesised using other methods suggesting their usefulness in catalytic applications. The hydrogen adsorption behaviour of cobalt doped carbon aerogel was evaluated, displaying a high {proportional_to}4.38 wt.% H{sub 2} uptake under 4.6 MPa at -196 C. The hydrogen uptake capacity with respect to unit surface area was greater than for pure carbon aerogel and resulted in {proportional_to}1.3 H{sub 2} (wt. %) per 500 m{sup 2} g{sup -1}. However, the total hydrogen uptake was slightly reduced as compared to pure carbon aerogel due to a small reduction in surface area associated with cobalt doping. The improved adsorption per unit surface area suggests that there is a stronger interaction between the hydrogen molecules and the cobalt doped carbon aerogel than for pure carbon aerogel. (author)

  14. Evacuation of mixed populations from trains on bridges

    DEFF Research Database (Denmark)

    Kindler, C.; Sørensen, J.G.; Dederichs, A.S.

    2012-01-01

    An understanding of human evacuation dynamics and performance are important when designing complex buildings such as bridges and when applying performance-based codes in order to reduce the risk of exposing occupants to critical conditions in case of fire. The majority of previous studies deal....... The discussion of "equal access" is only followed slowly by the demand on "equal egress". However, the passengers on trains on bridges are rarely homogeneous mixture. At the same time equal egress is far from assured today. In this paper the evacuation of mixed populations from trains on bridges are considered....... The populations applied in the experiment are mixed according to a composition corresponding to the population of Denmark. The study has the following findings: the total evacuation times increase with a factor 1.5 when accounting for a mixed population comprehending a variety of age and impairments. The seating...

  15. Simulation of the shopping center 'Zona I' evacuation

    Directory of Open Access Journals (Sweden)

    Jevtić Radoje B.

    2014-01-01

    Full Text Available One of the most important and the most complex tasks in human protection and human safety in objects is the projecting of the object evacuation. There are many factors that could effect on the opportune living of object such as object assignment, arrangement of rooms, arrangement of furniture, arrangement of exits, occupant speed and many other that human lives and material properties depend on. This is very important for objects with great number of humans, such as high residential objects, shopping centers, schools, hospitals etc. This paper has written to show the possible evacuation situations and calculate minimal time for evacuation in case of the shopping center 'Zona I' in Niš.

  16. Effectiveness and risks associated with sheltering and evacuation

    International Nuclear Information System (INIS)

    Mohseni, A.; McKenna, T.

    1995-01-01

    The United States Nuclear Regulatory Commission (NRC) and the Environmental Protection Agency (EPA) have assessed the risks and benefits associated with evacuation and sheltering following a severe reactor accident. In the case of a severe accident and the associated uncertainties with the source term and containment behaviour, these assessments suggest that prompt evacuation of areas close to the plant offers the highest protection of the public against acute doses. Sheltering may be used as an alternative in special circumstances where evacuation may not be feasible. The source term associated with reactor accidents and containment failure mechanism affect the effectiveness of different protective measures. A comparison of different protective measures is made and results discussed. (Author). 9 refs., 4 figs., 2 tabs

  17. A fast atom bombardment study of the lead isotope ratios in early nineteenth century Niagara Peninsula pottery glazes

    International Nuclear Information System (INIS)

    Miller, J.M.; Jones, T.R.B.; Kenney, Tina; Rupp, D.W.

    1986-01-01

    The application of fast atom bombardment (FAB) mass spectrometry to the determination of lead isotope ratios in nineteenth century pottery glazes from the Niagara Peninsula has been investigated with the aim of determining the source of the lead used in the glazes. Methods of sampling have been compared, including direct analysis of glass chips, analysis of powdered glaze scrapings, analysis of acid extracts of the former, and simple acid leaching of the surface of a piece of pottery. The latter method gave the best results. The FAB data, as obtained on an older mass spectrometer, can distinguish lead from igneous vs. sedimentary deposits, but is not adequate to determine specific mining locations. Although newer FAB instrumentation can narrow this range, the overlap of data from the Niagara Peninsula and England precludes a simple answer to the archeological question as to English vs. Canadian origin of the lead used in the Jordan pottery glazes. However, the data do suggest that the potter used a local source for the lead

  18. CLEAR (Calculates Logical Evacuation And Response): A generic transportation network model for the calculation of evacuation time estimates

    International Nuclear Information System (INIS)

    Moeller, M.P.; Desrosiers, A.E.; Urbanik, T. II

    1982-03-01

    This paper describes the methodology and application of the computer model CLEAR (Calculates Logical Evacuation And Response) which estimates the time required for a specific population density and distribution to evacuate an area using a specific transportation network. The CLEAR model simulates vehicle departure and movement on a transportation network according to the conditions and consequences of traffic flow. These include handling vehicles at intersecting road segments, calculating the velocity of travel on a road segment as a function of its vehicle density, and accounting for the delay of vehicles in traffic queues. The program also models the distribution of times required by individuals to prepare for an evacuation. In order to test its accuracy, the CLEAR model was used to estimate evacuation times for the emergency planning zone surrounding the Beaver Valley Nuclear Power Plant. The Beaver Valley site was selected because evacuation time estimates had previously been prepared by the licensee, Duquesne Light, as well as by the Federal Emergency Management Agency and the Pennsylvania Emergency Management Agency. A lack of documentation prevented a detailed comparison of the estimates based on the CLEAR model and those obtained by Duquesne Light. However, the CLEAR model results compared favorably with the estimates prepared by the other two agencies. (author)

  19. SCALING AN URBAN EMERGENCY EVACUATION FRAMEWORK: CHALLENGES AND PRACTICES

    Energy Technology Data Exchange (ETDEWEB)

    Karthik, Rajasekar [ORNL; Lu, Wei [ORNL

    2014-01-01

    Critical infrastructure disruption, caused by severe weather events, natural disasters, terrorist attacks, etc., has significant impacts on urban transportation systems. We built a computational framework to simulate urban transportation systems under critical infrastructure disruption in order to aid real-time emergency evacuation. This framework will use large scale datasets to provide a scalable tool for emergency planning and management. Our framework, World-Wide Emergency Evacuation (WWEE), integrates population distribution and urban infrastructure networks to model travel demand in emergency situations at global level. Also, a computational model of agent-based traffic simulation is used to provide an optimal evacuation plan for traffic operation purpose [1]. In addition, our framework provides a web-based high resolution visualization tool for emergency evacuation modelers and practitioners. We have successfully tested our framework with scenarios in both United States (Alexandria, VA) and Europe (Berlin, Germany) [2]. However, there are still some major drawbacks for scaling this framework to handle big data workloads in real time. On our back-end, lack of proper infrastructure limits us in ability to process large amounts of data, run the simulation efficiently and quickly, and provide fast retrieval and serving of data. On the front-end, the visualization performance of microscopic evacuation results is still not efficient enough due to high volume data communication between server and client. We are addressing these drawbacks by using cloud computing and next-generation web technologies, namely Node.js, NoSQL, WebGL, Open Layers 3 and HTML5 technologies. We will describe briefly about each one and how we are using and leveraging these technologies to provide an efficient tool for emergency management organizations. Our early experimentation demonstrates that using above technologies is a promising approach to build a scalable and high performance urban

  20. Noble Metal Immersion Spectroscopy of Silica Alcogels and Aerogels

    Science.gov (United States)

    Smith, David D.; Sibille, Laurent; Cronise, Raymond J.; Noever, David A.

    1998-01-01

    We have fabricated aerogels containing gold and silver nanoparticles for gas catalysis applications. By applying the concept of an average or effective dielectric constant to the heterogeneous interlayer surrounding each particle, we extend the technique of immersion spectroscopy to porous or heterogeneous media. Specifically, we apply the predominant effective medium theories for the determination of the average fractional composition of each component in this inhomogeneous layer. Hence, the surface area of metal available for catalytic gas reaction is determined. The technique is satisfactory for statistically random metal particle distributions but needs further modification for aggregated or surfactant modified systems. Additionally, the kinetics suggest that collective particle interactions in coagulated clusters are perturbed during silica gelation resulting in a change in the aggregate geometry.