WorldWideScience

Sample records for geopolymer column wrapping

  1. Nde of Frp Wrapped Columns Using Infrared Thermography

    Science.gov (United States)

    Halabe, Udaya B.; Dutta, Shasanka Shekhar; GangaRao, Hota V. S.

    2008-02-01

    This paper investigates the feasibility of using Infrared Thermography (IRT) for detecting debonds in Fiber Reinforced Polymer (FRP) wrapped columns. Laboratory tests were conducted on FRP wrapped concrete cylinders of size 6″×12″ (152.4 mm×304.8 mm) in which air-filled and water-filled debonds of various sizes were placed underneath the FRP wraps. Air-filled debonds were made by cutting plastic sheets into the desired sizes whereas water-filled debonds were made by filling water in custom made polyethylene pouches. Both carbon and glass fiber reinforced wraps were considered in this study. Infrared tests were conducted using a fully radiometric digital infrared camera which was successful in detecting air-filled as well as water-filled subsurface debonds. In addition to the laboratory testing, two field trips were made to Moorefield, West Virginia for detecting subsurface debonds in FRP wrapped timber piles of a railroad bridge using infrared testing. The results revealed that infrared thermography can be used as an effective nondestructive evaluation tool for detecting subsurface debonds in structural components wrapped with carbon or glass reinforced composite fabrics.

  2. Masonry Columns Confined by Steel Fiber Composite Wraps

    Directory of Open Access Journals (Sweden)

    Marco Corradi

    2011-01-01

    Full Text Available The application of steel fiber reinforced polymer (SRP as a means of increasing the capacity of masonry columns is investigated in this study. The behavior of 23 solid-brick specimens that are externally wrapped by SRP sheets in low volumetric ratios is presented. The specimens are subjected to axial monotonic load until failure occurs. Two widely used types of masonry columns of differing square cross-sections were tested in compression (square and octagonal cross-sections. It is concluded that SRP-confined masonry behaves very much like fiber reinforced polymers (FRP-confined masonry. Confinement increases both the load-carrying capacity and the deformability of masonry almost linearly with average confining stress. A comparative analysis between experimental and theoretical values computed in compliance with the Italian Council of Research (CNR was also developed.

  3. Behavior and Three-Dimensional Finite Element Modeling of Circular Concrete Columns Partially Wrapped with FRP Strips

    Directory of Open Access Journals (Sweden)

    Junjie Zeng

    2018-03-01

    Full Text Available Fiber-reinforced polymer (FRP jacketing/wrapping has become an attractive strengthening technique for concrete columns. Wrapping an existing concrete column with continuous FRP jackets with the fiber in the jacket being oriented in the hoop direction is referred to as FRP full wrapping strengthening technique. In practice, however, strengthening concrete columns with vertically discontinuous FRP strips is also favored and this technique is referred to as FRP partial wrapping strengthening technique. Existing research has demonstrated that FRP partial wrapping strengthening technique is a promising and economical alternative to the FRP full wrapping strengthening technique. Although extensive experimental investigations have hitherto been conducted on partially FRP-confined concrete columns, the confinement mechanics of confined concrete in partially FRP-confined circular columns remains unclear. In this paper, an experimental program consisting of fifteen column specimens was conducted and the test results were presented. A reliable three-dimensional (3D finite element (FE approach for modeling of partially FRP-confined circular columns was established. In the proposed FE approach, an accurate plastic-damage model for concrete under multiaxial compression is employed. The accuracy of the proposed FE approach was verified by comparisons between the numerical results and the test results. Numerical results from the verified FE approach were then presented to gain an improved understanding of the behavior of confined concrete in partially FRP-confined concrete columns.

  4. A Study on Load Carrying Capacity of Fly Ash Based Polymer Concrete Columns Strengthened Using Double Layer GFRP Wrapping

    Directory of Open Access Journals (Sweden)

    S. Nagan

    2014-01-01

    Full Text Available This paper investigates the suitability of glass fiber reinforced polymer (GFRP sheets in strengthening of fly ash based polymer members under compression. Experimental results revealed that load carrying capacity of the confined columns increases with GFRP sheets wrapping. Altogether 18 specimens of M30 and G30 grade short columns were fabricated. The G30 specimens were prepared separately in 8 molarity and 12 molarity of sodium hydroxide concentration. Twelve specimens for low calcium fly ash based reinforced polymer concrete and six specimens of ordinary Portland cement reinforced concrete were cast. Three specimens from each molarity fly ash based reinforced polymer concrete and ordinary Portland cement reinforced concrete were wrapped with double layer of GFRP sheets. The load carrying capacity of fly ash based polymer concrete was tested and compared with control specimens. The results show increase in load carrying capacity and ductility index for all strengthened elements. The maximum increase in load carrying capacity was 68.53% and is observed in strengthened G30 specimens.

  5. Hot-pressed geopolymer

    DEFF Research Database (Denmark)

    Ranjbar, Navid; Mehrali, Mohammad; Maheri, Mahmoud R.

    2017-01-01

    This research explores the use of simultaneous heating and pressing techniques in order to enhance the mechanical properties of fly ash (FA) based geopolymer under relatively low temperature conditions to ensure minimum-porosity. Four effective parameters of pressing force, alkali activator...

  6. Geopolymer Nanoceramic Mortar Liner System for Corrosion Protection and Rehabilitation of Stormwater Piping: Final Report on Project F14 AR05

    Science.gov (United States)

    2017-07-01

    wrapping with plastic and burlap or immersed in water. If a sample is immersed, it should be taken out of the water one day prior to testing (samples...implementation to ultimately recommend use of geopolymer liners for DoD stormwater and wastewater infrastructure. A new Unified Facilities Guide...reference request was created for UFGS 33 40 00 Storm Drainage Utilities. Caution is advised, however, for using a geopolymer liner in extremely acidic

  7. Behavior of concrete cylinders confined by a ferro-geopolymer jacket in axial compression

    Directory of Open Access Journals (Sweden)

    Kothay Heng

    2017-06-01

    Full Text Available It is beneficial to utilize geopolymers for their potential properties to rehabilitate concrete structures. These properties include high adhesion to Ordinary Portland Cement (OPC concrete even at low degrees of interfacial roughness, high durability and good fire resistance. This paper introduces use of a ferro-geopolymer jacket to strengthen concrete columns. It is a kind of jacket constructed with a geopolymer mortar reinforced with a wire mesh. This study was conducted to investigate the behavior of concrete cylinders confined with a ferro-geopolymer jacket in axial compression. OPC concrete cylinders with 100 mm diameter and 200 mm height were fabricated. High calcium fly ash-based geopolymer mortar, activated with sodium hydroxide (NaOH and sodium silicate (Na2SiO3, cured at a temperature of 25 ºC was used. Ferro-geopolymer jackets with a25 mm thickness, were reinforced with 1, 2 and 3 layers of expanded metal mesh and cast around concrete cylinders. The study results revealed that the compressive load carrying capacity and axial stiffness of concrete cylinders were improved. A monolithic failure mode was obtained as a result of a strong adhesion between the geopolymer and the concrete core. Enhancement of compressive load carrying capacity of the jacketed concrete cylinders was caused by a combination of a confinement effect and the compressive load resistance of the jacket transferred from concrete core through bonding.

  8. Geopolymer obtained from coal ash

    International Nuclear Information System (INIS)

    Conte, V.; Bissari, E.S.; Uggioni, E.; Bernardin, A.M.

    2011-01-01

    Geopolymers are three-dimensional alumino silicates that can be rapidly formed at low temperature from naturally occurring aluminosilicates with a structure similar to zeolites. In this work coal ash (Tractebel Energy) was used as source of aluminosilicate according a full factorial design in eight formulations with three factors (hydroxide type and concentration and temperature) and two-levels. The ash was dried and hydroxide was added according type and concentration. The geopolymer was poured into cylindrical molds, cured (14 days) and subjected to compression test. The coal ash from power plants belongs to the Si-Al system and thus can easily form geopolymers. The compression tests showed that it is possible to obtain samples with strength comparable to conventional Portland cement. As a result, temperature and molarity are the main factors affecting the compressive strength of the obtained geopolymer. (author)

  9. Strength of Geopolymer Cement Curing at Ambient Temperature by Non-Oven Curing Approaches: An Overview

    Science.gov (United States)

    Wattanachai, Pitiwat; Suwan, Teewara

    2017-06-01

    At the present day, a concept of environmentally friendly construction materials has been intensively studying to reduce the amount of releasing greenhouse gases. Geopolymer is one of the cementitious binders which can be produced by utilising pozzolanic wastes (e.g. fly ash or furnace slag) and also receiving much more attention as a low-CO2 emission material. However, to achieve excellent mechanical properties, heat curing process is needed to apply to geopolymer cement in a range of temperature around 40 to 90°C. To consume less oven-curing energy and be more convenience in practical work, the study on geopolymer curing at ambient temperature (around 20 to 25°C) is therefore widely investigated. In this paper, a core review of factors and approaches for non-oven curing geopolymer has been summarised. The performance, in term of strength, of each non-oven curing method, is also presented and analysed. The main aim of this review paper is to gather the latest study of ambient temperature curing geopolymer and to enlarge a feasibility of non-oven curing geopolymer development. Also, to extend the directions of research work, some approaches or techniques can be combined or applied to the specific properties for in-field applications and embankment stabilization by using soil-cement column.

  10. Geopolymer resin materials, geopolymer materials, and materials produced thereby

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Dong-Kyun; Medpelli, Dinesh; Ladd, Danielle; Mesgar, Milad

    2018-01-09

    A product formed from a first material including a geopolymer resin material, a geopolymer material, or a combination thereof by contacting the first material with a fluid and removing at least some of the fluid to yield a product. The first material may be formed by heating and/or aging an initial geopolymer resin material to yield the first material before contacting the first material with the fluid. In some cases, contacting the first material with the fluid breaks up or disintegrates the first material (e.g., in response to contact with the fluid and in the absence of external mechanical stress), thereby forming particles having an external dimension in a range between 1 nm and 2 cm.

  11. Geopolymer resin materials, geopolymer materials, and materials produced thereby

    Science.gov (United States)

    Seo, Dong-Kyun; Medpelli, Dinesh; Ladd, Danielle; Mesgar, Milad

    2016-03-29

    A product formed from a first material including a geopolymer resin material, a geopolymer resin, or a combination thereof by contacting the first material with a fluid and removing at least some of the fluid to yield a product. The first material may be formed by heating and/or aging an initial geopolymer resin material to yield the first material before contacting the first material with the fluid. In some cases, contacting the first material with the fluid breaks up or disintegrates the first material (e.g., in response to contact with the fluid and in the absence of external mechanical stress), thereby forming particles having an external dimension in a range between 1 nm and 2 cm.

  12. Geopolymers and Their Uses: Review

    Science.gov (United States)

    Burduhos Nergis, D. D.; Abdullah, M. M. A. B.; Vizureanu, P.; Tahir, M. F. M.

    2018-06-01

    Outlining the past-present history of the study of alumino-silicate materials, it is well known that geopolymers are inorganic polymers obtained from chemical reaction, also known as geopolymerisation, between an alkaline solution and a solid reach in aluminium and silicone. There is still some controversy surrounding the alkaline activators used to create geopolymer concrete, because homogeneous mixture composed of two (NaOH and Na2SO3) or more chemical in varying proportions are usually highly corrosive and hard to handle. In order to overcome Portland cement many wastes have been used in recent studies to create “friendly” cements by geopolymerisation. In this short review we present basic information’s about how to create and use geopolymers, alkaline activators and raw materials that can be used and conclusions. One question that needs to be asked: Can those materials replace on large scale Portland cement?

  13. Manufacturing of Fire Resistance Geopolymer: A Review

    Directory of Open Access Journals (Sweden)

    Aziz Ikmal Hakem

    2016-01-01

    Full Text Available Protection against fire using inorganic polymer is a new application of engineering technology. Even though, there are varieties of fire-protection materials, there is always a need for the development of new materials with improved thermophysical properties and low cost. Geopolymer composites materials are promising from this point of view. Granulated blast furnace slag, boiler ash and fly ash have been used as the prime materials for forming geopolymers composites. Geopolymers have been studied due to its unique properties such as a good fire resistance. Geopolymer offers an innovative for application associated with the high thermal application. This paper summarizes on the potential of alkaliactivated materials over the past decades along with outlines of the manufacturing of geopolymer composites for fire resistance application.

  14. Cementation of Nuclear Graphite Using Geopolymers

    International Nuclear Information System (INIS)

    Girke, N.A.; Steinmetz, H-J.; Bukaemsky, A.; Bosbach, D.; Hermann, E.; Griebel, I.

    2016-01-01

    Geopolymers are solid aluminosilicate materials usually formed by alkali hydroxide or alkali silicate activation of solid precursors such as coal fly ash, calcined clay and/or metallurgical slag. Today the primary application of geopolymer technology is in the development of alternatives to Portland-based cements. Variations in the ratio of aluminium to silicon, and alkali to silicon or addition of structure support, produce geopolymers with different physical and mechanical properties. These materials have an amorphous three-dimensional structure that gives geopolymers certain properties, such as fire and acid resistance, low leach rate, which make them an ideal substitute for ordinary Portland cement (OPC) in a wide range of applications especially in conditioning and storage of radioactive waste. Therefore investigations have been initiated on how and to which amount graphite as a hydrophobic material can be mixed with cement or concrete to form stable waste products and which concretes fulfil the necessary specifications best. As a result, geopolymers have been identified as a promising matrix for graphite containing nuclear wastes. With geopolymers, both favourable properties in the cementation process and a high long time structural stability of the products can be achieved. Investigations include: • direct mixing of graphite with geopolymers with or without sand as a mechanically stabilizing medium; • production of cement-graphite granulates as intermediate products and embedding of these granulates in geopolymer; • coating of formed graphite pieces with geopolymer.The report shows that carbon in the form of graphite can both be integrated with different grain size spectra as well as shaped in the hydraulic binder geopolymer and meets the requirements for a stable long-term immobilisation. (author)

  15. Alkaline Activator Impact on the Geopolymer Binders

    Science.gov (United States)

    Błaszczyński, Tomasz Z.; Król, Maciej R.

    2017-10-01

    Concrete structures are constantly moving in the direction of improving the durability. Durability depends on many factors, which are the composition of concrete mix, the usage of additives and admixtures and the place, where material will work and carry the load. The introduction of new geopolymer binders for geopolymer structures adds a new aspect that is type of used activator. This substance with strongly alkaline reaction is divided because of the physical state, the alkaline degree and above all the chemical composition. Taking into account, that at present the geopolymer binders are made essentially from waste materials or by-products from the combustion of coal or iron ore smelting, unambiguous determination of the effect of the activator on the properties of the geopolymer material requires a number of trials, researches and observation. This paper shows the influence of the most alkaline activators on the basic parameters of the durability of geopolymer binders. In this study there were used highly alkaline hydroxides, water glasses and granules, which are waste materials in a variety of processes taking place in chemical plants. As the substrate of geopolymer binders there were used fly ash which came from coal and high calcareous ash from the burning of lignite.

  16. Identity as wrapping up

    DEFF Research Database (Denmark)

    Nickelsen, Niels Christian Mossfeldt

    2015-01-01

    The aim of this paper is to provide an understanding of cross-professional collaboration and to develop a notion of professional identity based in practice. The background of the paper is science and technology studies and more precisely actor network theory. The method used: The empirical analysis...... in close relation to the making of a report concerning the cross-professional collaboration. Findings are that “Identity as wrapping up” points to the way in which certain actors, by other actors, are maneuvered into certain pockets in a network. Identity as wrapping up is emphasized as a way...... of participating, which is closely connected to the intention to control the relation towards the other. Thus identity as wrapping up is argued to be a strategy to optimize the situation of one’s own profession. Conclusion: This articulation of identity contributes to the actor network literature as well...

  17. Non-Traditional Wraps

    Science.gov (United States)

    Owens, Buffy

    2009-01-01

    This article presents a recipe for non-traditional wraps. In this article, the author describes how adults and children can help with the recipe and the skills involved with this recipe. The bigger role that children can play in the making of the item the more they are apt to try new things and appreciate the texture and taste.

  18. Plaster-Wrap Dragons

    Science.gov (United States)

    Vance, Shelly

    2012-01-01

    In this article, the author describes how her students constructed a three-dimensional sculpture of a dragon using plaster wrap and other materials. The dragons were formed from modest means--using only a toilet-paper tube, newsprint, tape and wire.

  19. Review of Dolomite as Precursor of Geopolymer Materials

    Directory of Open Access Journals (Sweden)

    Azimi E.A.

    2016-01-01

    Full Text Available Geopolymer is an environmentally friendly cementitious binder that does not require the existence of ordinary Portland cement (OPC. Geopolymer has many excellent advantages, including high early strength, low shrinkage, good thermal resistance and good chemical resistance. Previous commonly used materials include fly ash, clay and slag. The used of dolomite as precursor material in geopolymer field is still new and at the early stage of study. Only a few researchers have done studies on dolomite in geopolymer. Dolomite (CaMg(CO32 is abundant and generally inexpensive natural minerals. The possible use of these bulk calcium carbonate materials in improving the mechanical properties of geopolymers will therefore be of great interest. This paper summarizes some research outcomes on dolomite in geopolymer along with the potential of dolomite as geopolymer composites.

  20. Mechanical properties on geopolymer brick: A review

    Science.gov (United States)

    Deraman, L. M.; Abdullah, M. M. A.; Ming, L. Y.; Ibrahim, W. M. W.; Tahir, M. F. M.

    2017-09-01

    Bricks has stand for many years as durable construction substantial, especially in the area of civil engineering to construct buildings. Brick commonly used in the structure of buildings as a construction wall, cladding, facing perimeter, paving, garden wall and flooring. The contribution of ordinary Portland cement (OPC) in cement bricks production worldwide to greenhouse gas emissions. Due to this issue, some researchers have done their study with other materials to produce bricks, especially as a by-product material. Researchers take effort in this regard to synthesizing from by-product materials such as fly ash, bottom ash and kaolin that are rich in silicon and aluminium in the development of inorganic alumina-silicate polymer, called geopolymer Geopolymer is a polymerization reaction between various aluminosilicate oxides with silicates solution or alkali hydroxide solution forming polymerized Si-O-Al-O bonds. This paper summarized some research finding of mechanical properties of geopolymer brick using by-product materials.

  1. Development of rubberized geopolymer interlocking bricks

    Directory of Open Access Journals (Sweden)

    Bashar S Mohammed

    2018-06-01

    Full Text Available Waste tires contribute badly to the environment on a huge scale as they are bulky, non-biodegradable, and prone to fire and being a shelter for mosquitos and other insects. This paper reports on a novel approach towards the development of rubberized brick by utilizing crumb rubber as the sole fine aggregate in the production of geopolymer interlocking bricks. The response surface methodology (RSM from Design Experts software has been used to determine the numbers of trial mixes and their corresponding ingredients. A total of thirteen trial mixes were carried out and tested for compressive strength and the RSM model was developed to predict the design mix based on the targeted compressive strength. The mix design was obtained to be an 18 M for NaOH and 0.8 solution to fly ash ratio. The geopolymer interlocking rubberized bricks were then produced and tested for compressive strength, dimension, modulus of rupture, water absorption, initial rate of absorption, and efflorescence. The geopolymer interlocking rubberised bricks presented a low compressive and flexural strength and a high-water absorption capacity. The bricks were rated as non-effloresced and classified as 3rd class bricks which can be used as non-load bearing material. It is recommended to utilize nano silica in order to increase the strength of the brick. Keywords: Rubberized bricks, Crumb rubber, Interlocking bricks, Geopolymer, Response surface methodology

  2. Thermal characterization of metakaolin-based geopolymer

    Czech Academy of Sciences Publication Activity Database

    Samal, Sneha Manjaree; Thanh, N.P.; Marvalová, B.; Petrikova, I.

    2017-01-01

    Roč. 69, č. 12 (2017), s. 2480-2484 ISSN 1047-4838 Institutional support: RVO:68378271 Keywords : thermal * characterization * geopolymer Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 1.860, year: 2016

  3. Alkali-Activated Geopolymers: A Literature Review

    Science.gov (United States)

    2010-07-01

    strength and reasonable toughness, while adding short basalt fibers reduced the strength of tested specimens and drastically improved the work of fracture...27 6.3.1. Fiber Reinforcement...characteristics  Mineralogical and microstructural analysis of products  Chemical and thermal resistance properties of geopolymer matrices  Fiber

  4. Determination of anisotropy and multimorphology in fly ash based geopolymers

    Energy Technology Data Exchange (ETDEWEB)

    Khan, M. Irfan, E-mail: mirfanwazir@gmail.com; Azizli, Khairun, E-mail: khairun-azizli@petronas.com.my; Sufian, Suriati, E-mail: suriati@petronas.com.my; Man, Zakaria, E-mail: zakaman@petronas.com.my; Siyal, Ahmer Ali, E-mail: ahmersiyal@gmail.com; Ullah, Hafeez, E-mail: Hafeez-wazir@yahoo.com [Department of Chemical Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750, Tronoh, Perak (Malaysia)

    2015-07-22

    In this study, Malaysian coal fly ash-based geopolymers were investigated for its morphology and chemical composition using scanning electron microscopy coupled with energy dispersive X-rays (SEM-EDX). Geopolymer was synthesized using sodium hydroxide as activator. SEM studies revealed multiphasous structure of the material, composed of geopolymeric gel, partially reacted fly ashparticles and selectively leached particles. EDX analysis confirmed the chemical composition of different regions. Infra red spectroscopic studies supported the SEM-EDX analysis by confirming presence of unreacted quartzite and mullite in geopolymers. It is concluded that geopolymers possese a non uniform chemistry through out the structure.

  5. Wrapped Multilayer Insulation

    Science.gov (United States)

    Dye, Scott A.

    2015-01-01

    New NASA vehicles, such as Earth Departure Stage (EDS), Orion, landers, and orbiting fuel depots, need improved cryogenic propellant transfer and storage for long-duration missions. Current cryogen feed line multilayer insulation (MLI) performance is 10 times worse per area than tank MLI insulation. During each launch, cryogenic piping loses approximately 150,000 gallons (equivalent to $300,000) in boil-off during transfer, chill down, and ground hold. Quest Product Development Corp., teaming with Ball Aerospace, developed an innovative advanced insulation system, Wrapped MLI (wMLI), to provide improved thermal insulation for cryogenic feed lines. wMLI is high-performance multilayer insulation designed for cryogenic piping. It uses Quest's innovative discrete-spacer technology to control layer spacing/ density and reduce heat leak. The Phase I project successfully designed, built, and tested a wMLI prototype with a measured heat leak 3.6X lower than spiral-wrapped conventional MLI widely used for piping insulation. A wMLI prototype had a heat leak of 7.3 W/m2, or 27 percent of the heat leak of conventional MLI (26.7 W/m2). The Phase II project is further developing wMLI technology with custom, molded polymer spacers and advancing the product toward commercialization via a rigorous testing program, including developing advanced vacuuminsulated pipe for ground support equipment.

  6. In situ monitoring of the hydration process of K-PS geopolymer cement with ESEM

    International Nuclear Information System (INIS)

    Sun Wei; Zhang Yunsheng; Lin Wei; Liu Zhiyong

    2004-01-01

    Environmental scanning electron microscope (ESEM) was used to in situ quantitatively study the hydration process of K-PS geopolymer cement under an 80% RH environment. An energy dispersion X-ray analysis (EDXA) was also employed to distinguish the chemical composition of hydration product. The ESEM micrographs showed that metakaolin particles pack loosely at 10 min after mixing, resulting in the existence of many large voids. As hydration proceeds, a lot of gels were seen and gradually precipitated on the surfaces of these particles. At later stage, these particles were wrapped by thick gel layers and their interspaces were almost completely filled. The corresponding EDXA results illustrated that the molar ratios of K/Al increase while Si/Al decrease with the development of hydration. As a result, the molar ratios of K/Al and Si/Al of hydration products at an age of 4 h amounted to 0.99 and 1.49, respectively, which were close to the theoretical values (K/Al=1.0, Si/Al=1.0 for K-PS geopolymer cement paste). In addition, well-developed crystals could not been found at any ages; instead, spongelike amorphous gels were always been observed

  7. Cost and Ductility Effectiveness of Concrete Columns Strengthened with CFRP and SFRP Sheets

    Directory of Open Access Journals (Sweden)

    Khaled Abdelrahman

    2014-05-01

    Full Text Available Recently, steel fibre reinforced polymers (SFRP sheets have been introduced for the repair and rehabilitation of concrete structures. Few researchers studied the behaviour of the concrete columns wrapped with SFRP sheets; however, several critical parameters such as the cost and ductility effectiveness of the SFRP wrapped concrete columns have been lightly addressed. Thus, the main objective of this paper is to study the cost and ductility effectiveness of SFRP wrapped concrete columns and compare the results with the conventionally used carbon FRP (CFRP wrapped concrete columns. In addition, an analytical procedure to predict the cost effectiveness of SFRP wrapped concrete columns is also suggested, from which, a parametric study was conducted. The parametric study investigated the effect of the concrete strength, the number of SFRP layers, and the size and slenderness effects on the cost effectiveness of the concrete columns wrapped with SFRP sheets. The results from the cost and ductility effectiveness study indicated that the SFRP wrapped concrete columns showed enhanced performance over the CFRP wrapped concrete columns. The suggested analytical procedure proved to be a reliable and accurate method to predict the cost effectiveness parameter of SFRP wrapped concrete columns. The parametric study showed the significant impact of the investigated parameters on the cost effectiveness of concrete columns wrapped with SFRP sheets.

  8. Workability enhancement of geopolymer concrete through the use of retarder

    Science.gov (United States)

    Umniati, B. Sri; Risdanareni, Puput; Zein, Fahmi Tarmizi Zulfikar

    2017-09-01

    Geopolymer concrete is a type of concrete manufactured without the addition of cement. In geopolymer concrete, along with an activator, cement as the concrete binder can be replaced by the fly ash. This will reduce global demand on cement, and therefore will reduce CO2 emission due to cement production. Thus, geopolymer concrete is commonly known as an eco-friendly concrete. Geopolymer concrete also offers a solution concerning with the utilization of the fly ash waste. However, despite of its environmental advantages, geopolymer concrete has a drawback, namelygeopolymer concrete set quickly, thus reducing its workability. This research aimed to increase the workability of geopolymer concrete by using retarder admixture (Plastocrete RT6 Plus). Retarder used varies within 0.2%, 0.4% and 0.6% of fly ash mass. As a control, geopolymer concrete without retarder (0%) were also made. Activator used in this research was Na2SiO3 mixed with NaOH 10 M solution, with ratio of 1:5. The results showed an optimum composition of geopolymer concrete with 0.6% retarder, where initial setting time occured after 6.75 hours, and the final setting time reached after 9.5 hours. Moreover, the slump of the geopolymer concrete was 8.8 cm, and the slump flow was 24 cm. The compressive strength of the geopolymer concrete at 28 days was 47.21 MPa. The experiment showed that the more retarder added, the setting time of the geopolymer concrete will be increased, thus increasing its workability.

  9. Wrap Spinning: Principles and Development

    CSIR Research Space (South Africa)

    Brydon, AG

    1986-02-01

    Full Text Available A wrap yarn is a composite structure comprising a core of twisted or twisted fibres bound by a yarn or continuous filament. The term wrap yarn therefore include yarns produced by the hollow spindle method as well as similar structure such as selfil...

  10. Screening coal combustion fly ashes for application in geopolymers

    NARCIS (Netherlands)

    Valcke, S.L.A.; Pipilikaki, P.; Sarabér, A.J.; Fischer, H.R.; Nugteren, H.W.

    2013-01-01

    Driven by cost and sustainability, secondary resource materials such as fly ash, blast furnace slag, and bottom ash are increasingly used for alternative types of concrete binders, such as geopolymers. Because secondary resources may be highly variable from the perspective of geopolymers, it is

  11. Asian-Style Chicken Wraps

    Science.gov (United States)

    ... https://medlineplus.gov/recipe/asianstylechickenwraps.html Asian-Style Chicken Wraps To use the sharing features on this ... Tbsp lime juice (or about 2 limes) For chicken: 1 Tbsp peanut oil or vegetable oil 1 ...

  12. The Effect of Corrosive Environment on Geopolymer Concrete Tensile Strength

    Directory of Open Access Journals (Sweden)

    Bayuaji Ridho

    2017-01-01

    Full Text Available This study has the purpose to explore the potential of geopolymer concrete tensile strength in particular on the effects of corrosive environments. Geopolymer concrete, concrete technology used no OPC that has advantages, one of which is durability, especially for corrosive seawater environment. In addition, geopolymer concrete with polymerization mechanism does not require large energy consumption or an environmentally friendly concept. Geopolymer concrete in this study is using a type C fly ash from PT. International Power Mitsui Operation & Maintenence Indonesia (IPMOMI Paiton. The type of alkaline activator used NaOH (14 molar and Na2SiO3. Coarse and fine aggregate used are local aggregate. Geopolymer concrete molded test specimen with dimensions of (10 × 20 cm cylinder, further heating and without heating, then maintained at room temperature and seawater up to 28 days. Then to determine the mechanical properties, the tensile strength testing is done with reference. This result of study indicates the curing of geopolymer concrete at 60 ° C for 24 hours to raise the tensile strength of geopolymer concrete.

  13. Effect of fire exposure on cracking, spalling and residual strength of fly ash geopolymer concrete

    International Nuclear Information System (INIS)

    Sarker, Prabir Kumar; Kelly, Sean; Yao, Zhitong

    2014-01-01

    Highlights: • Fire endurance of fly ash geopolymer concrete has been studied. • No spalling in geopolymer concrete cylinders up to 1000 °C fire. • Less cracking and better fire endurance of geopolymer concrete than OPC concrete. • Geopolymer microstructure remained stable up to 1000 °C fire. - Abstract: Fly ash based geopolymer is an emerging alternative binder to cement for making concrete. The cracking, spalling and residual strength behaviours of geopolymer concrete were studied in order to understand its fire endurance, which is essential for its use as a building material. Fly ash based geopolymer and ordinary portland cement (OPC) concrete cylinder specimens were exposed to fires at different temperatures up to 1000 °C, with a heating rate of that given in the International Standards Organization (ISO) 834 standard. Compressive strength of the concretes varied in the range of 39–58 MPa. After the fire exposures, the geopolymer concrete specimens were found to suffer less damage in terms of cracking than the OPC concrete specimens. The OPC concrete cylinders suffered severe spalling for 800 and 1000 °C exposures, while there was no spalling in the geopolymer concrete specimens. The geopolymer concrete specimens generally retained higher strength than the OPC concrete specimens. The Scanning Electron Microscope (SEM) images of geopolymer concrete showed continued densification of the microstructure with the increase of fire temperature. The strength loss in the geopolymer concrete specimens was mainly because of the difference between the thermal expansions of geopolymer matrix and the aggregates

  14. Formulation of caesium based and caesium containing geo-polymers

    Energy Technology Data Exchange (ETDEWEB)

    Berger, S.; Joussot-Dubien, C.; Frizon, F. [CEA Valrho, Dir. de l' Energie Nucleaire, DEN, Decontamination and Conditioning Department, DEN/DTCD/SPDE/L2ED, 30 - Marcoule (France)

    2009-10-15

    Cement encapsulation is widely used as a low- and intermediate level radioactive waste immobilisation process. Among these wastes, caesium ions are poorly immobilised by Portland cement based materials. This work consists of an experimental investigation into the ability of geo-polymers to effectively encapsulate this chemical species and to determine the impact of caesium incorporation on the geo-polymer properties. Geo-polymers were synthesised with several compositions based on the activation of metakaolin with an alkali hydroxide solution containing caesium. The setting time, mineralogy, porosity and mechanical properties of the samples were examined for one month. Leach tests were conducted during the same period to determine the immobilisation efficiency. The results depend to a large extent on the composition of the activation solution in terms of soluble silica content and alkali used. These parameters determine both the degree of condensation and the geo-polymer composition. (authors)

  15. The solidification of aluminum production waste in geopolymer matrix

    Czech Academy of Sciences Publication Activity Database

    Perná, Ivana; Hanzlíček, Tomáš

    2014-01-01

    Roč. 84, DEC 1 (2014), s. 657-662 ISSN 0959-6526 Institutional support: RVO:67985891 Keywords : aluminum waste * solidification * recycling * geopolymer Subject RIV: DM - Solid Waste and Recycling Impact factor: 3.844, year: 2014

  16. Formulation of caesium based and caesium containing geo-polymers

    International Nuclear Information System (INIS)

    Berger, S.; Joussot-Dubien, C.; Frizon, F.

    2009-01-01

    Cement encapsulation is widely used as a low- and intermediate level radioactive waste immobilisation process. Among these wastes, caesium ions are poorly immobilised by Portland cement based materials. This work consists of an experimental investigation into the ability of geo-polymers to effectively encapsulate this chemical species and to determine the impact of caesium incorporation on the geo-polymer properties. Geo-polymers were synthesised with several compositions based on the activation of metakaolin with an alkali hydroxide solution containing caesium. The setting time, mineralogy, porosity and mechanical properties of the samples were examined for one month. Leach tests were conducted during the same period to determine the immobilisation efficiency. The results depend to a large extent on the composition of the activation solution in terms of soluble silica content and alkali used. These parameters determine both the degree of condensation and the geo-polymer composition. (authors)

  17. Physicochemical Characterization of Geopolymer Binders and Foams Made from Tunisian Clay

    Directory of Open Access Journals (Sweden)

    Imen Ben Messaoud

    2018-01-01

    Full Text Available Illito-kaolinitic clay rich in hematite from south Tunisia was investigated in view of producing geopolymer materials. Geopolymers with two different densities were elaborated: cement and foam. The effects of activator concentrations on compressive strength, water absorption (durability, open porosity, and bulk density of geopolymers cement were examined, in order to assure optimal geopolymerization conditions. Geopolymer cements aged 28 days with optimum performances were achieved for 13 M of alkaline solution concentration. At these conditions, the compressive strength of prepared geopolymer reaches 27.8 MPa. The addition of silica fume to reactant geopolymer mixture induces modification of geopolymer density and decrease in the compressive strength of the final product. Geopolymer materials based on calcined Tunisian clay can be suggested as sustainable and cost-effective cement that may be applied to alternate Portland cement in many construction applications.

  18. Effect of Alkali Concentration on Fly Ash Geopolymers

    Science.gov (United States)

    Fatimah Azzahran Abdullah, Siti; Yun-Ming, Liew; Bakri, Mohd Mustafa Al; Cheng-Yong, Heah; Zulkifly, Khairunnisa; Hussin, Kamarudin

    2018-03-01

    This paper presents the effect of NaOH concentration on fly ash geopolymers with compressive up to 56 MPa at 12M. The physical and mechanical on fly ash geopolymer are investigated. Test results show that the compressive strength result complied with bulk density result whereby the higher the bulk density, the higher the strength. Thus, the lower water absorption and porosity due to the increasing of NaOH concentration.

  19. Cementation of nuclear graphite using geo-polymers

    International Nuclear Information System (INIS)

    Girke, N.A.; Steinmetz, H.J.; Bukaemsky, A.; Bosbach, D.; Hermann, E.; Griebel, I.

    2012-01-01

    Geo-polymers are solid aluminosilicate materials usually formed by alkali hydroxide or alkali silicate activation of solid precursors such as coal fly ash, calcined clay and/or metallurgical slag. Today the primary application of geo-polymer technology is in the development of alternatives to Portland-based cements. Variations in the ratio of aluminium to silicon, and alkali to silicon or addition of structure support, produce geo-polymers with different physical and mechanical properties. These materials have an amorphous three-dimensional structure that gives geo-polymers certain properties, such as fire and acid resistance, low leach rate, which make them an ideal substitute for ordinary Portland cement (OPC) in a wide range of applications especially in conditioning and storage of radioactive waste. Therefore investigations have been initiated about how and to which amount graphite as a hydrophobic material can be mixed with cement or concrete to form stable waste products and which concretes fulfill the specifications at best. As result geo-polymers have been identified as a promising matrix for graphite containing nuclear wastes. With geo-polymers both favorable properties in the cementation process and a high long time structural stability of the products can be achieved. (authors)

  20. Morphology and Properties of Geopolymer Coatings on Glass Fibre-Reinforced Epoxy (GRE pipe

    Directory of Open Access Journals (Sweden)

    Shahedan Noor Fifinatasha

    2016-01-01

    Full Text Available Geopolymer coatings were coated on glass fibre-reinforced epoxy (GRE pipe by using kaolin, white clay and silica sand as source materials and sodium hydroxide (NaOH and sodium silicate (Na2SiO3 as alkaline solution. The microstructure and mechanical property of geopolymer coating on GRE pipe were methodically investigated through morphology analysis, and flexural strength test. The result indicates the microstructure and interfacial layer between geopolymer coating and GRE pipe significantly influence the mechanical property of geopolymer coating. However, different source materials gave different microstructure and property in geopolymer coating.

  1. WRAP 2A product specification

    International Nuclear Information System (INIS)

    Parker, K.E.

    1993-01-01

    WRAP-2A will process mixed and low-level waste (MLLW) for disposal. The final treatment processes selected for use in WRAP-2A consist of stabilization using cementitious materials and immobilization using thermosetting polymers. Modifications or additions to these processes may be made as technology improvements become known. Knowledge of the diverse waste forms that must be processed will be important to the effective exploration of process technologies that may be available. This document is a compilation of the current knowledge of the waste and process methods specified for each type of waste. As the uncertainties associated with the waste and methods of processing are addressed and resolved, revisions to this document will be made. This document is broken down by feed stream, source of the waste, waste codes, radiological characterization and recommended final forms of the waste for each stream

  2. Effect of Grinding Fineness of Fly Ash on the Properties of Geopolymer Foam

    Directory of Open Access Journals (Sweden)

    Szabó R.

    2017-06-01

    Full Text Available Present paper deals with the development of geopolymer foam prepared from ground F class power station fly ash. The effect of the fly ash fineness on the rheology of the geopolymer paste and the foam properties have been investigated. The raw fly ash was ground in a ball mill for various duration, 5, 10, 20, 30, 60 and 120 min. Geopolymer paste was prepared from the raw and ground fly ash with NaOH – sodium silicate mixture as alkaline activator. Geopolymer foam production was made using H2O2 as foaming agent. Additionally, the geopolymer material structure was investigated by Fourier transform infrared spectrometer, the foam cell structure was monitored using optical microscopy. The rheological behaviour of the geopolymer paste changed due to the grinding of fly ash (from Bingham plastic to Newtonian liquid. Grinding of fly ash has a significant effect on the physical properties as well as on the cell structure of the geopolymer foam.

  3. Branes wrapped on coassociative cycles

    International Nuclear Information System (INIS)

    Hernandez, Rafael

    2001-06-01

    We obtain a supergravity solution arising when D6-branes are wrapped on coassociative four-cycles of constant curvature in seven manifolds of G 2 holonomy. The solutions preserve two supercharges and thus represent supergravity duals of three dimensional Yang-Mills with N=1 supersymmetry. When uplifted to eleven dimensions our solution describes M-theory on the background of an eight manifold with Spin(7) holonomy. (author)

  4. Characterisation of irradiation effect on geo-polymers

    International Nuclear Information System (INIS)

    Chupin, Frederic

    2015-01-01

    This study aims to improve knowledge about the radiation effect on geo-polymer behavior in terms of dihydrogen release and general strength in order to consider them as an alternative to usual nuclear waste cementitious coating matrices. Using various characterization techniques (nitrogen adsorption, low temperature DSC, FTIR and 1 H NMR spectroscopy) and by means of simulation irradiations (gamma, heavy ions), it has been shown that all the water present in the geo-polymer could be radiolyzed and that there was a confinement effect on the water radiolysis under low LET irradiation, probably due to efficient energy transfers from the solid matrix to the interstitial solution. Three dihydrogen production rates have been identified with the absorbed dose, depending on the concentration of dissolved dioxygen and the dihydrogen accumulation in the geo-polymer matrix. The good mechanical strength of the geo-polymer has been shown up to 9 MGy under gamma irradiation and is due to its high stability under irradiation. This could be explained by the fast recombination of the defects observed by EPR spectroscopy. However, phase crystallization was revealed during irradiation with heavy ions, which may induce some weakening of the geo-polymer network under alpha irradiation. The overall results helped to understand the phenomenology in a waste package under storage conditions. (author) [fr

  5. Encapsulation of aluminium in geopolymers produced from metakaolin

    Energy Technology Data Exchange (ETDEWEB)

    Kuenzel, C. [Department of Civil and Environmental Engineering, Imperial College London (United Kingdom); Centre for Advanced Structural Ceramics, Department of Materials, Imperial College London (United Kingdom); Neville, T.P. [Centre for CO_2 Technology, Department of Chemical Engineering, University College London (United Kingdom); Omakowski, T. [Flowcrete, Group Ltd., Cheshire (United Kingdom); Vandeperre, L. [Centre for Advanced Structural Ceramics, Department of Materials, Imperial College London (United Kingdom); Boccaccini, A.R. [Institute of Biomaterials, University of Erlangen-Nuremberg (Germany); Bensted, J.; Simons, S.J.R. [Centre for CO_2 Technology, Department of Chemical Engineering, University College London (United Kingdom); Cheeseman, C.R., E-mail: c.cheeseman@imperial.ac.uk [Department of Civil and Environmental Engineering, Imperial College London (United Kingdom)

    2014-04-01

    Magnox swarf contaminated with trace levels of Al metal is an important UK legacy waste originated from the fuel rod cladding system used in Magnox nuclear power stations. Composite cements made from Portland cement and blast furnace slag form a potential encapsulation matrix. However the high pH of this system causes the Al metal to corrode causing durability issues. Geopolymers derived from metakaolin are being investigated as an alternative encapsulation matrix for Magnox swarf waste and the corrosion kinetics and surface interactions of Al with metakaolin geopolymer are reported in this paper. It is shown that the pH of the geopolymer paste can be controlled by the selection of metakaolin and the sodium silicate solution used to form the geopolymer. A decrease in pH of the activation solution reduces corrosion of the Al metal and increases the stability of bayerite and gibbsite layers formed on the Al surface. The bayerite and gibbsite act as a passivation layer which inhibits further corrosion and mitigates H{sub 2} generation. The research shows that optimised metakaolin geopolymers have potential to be used to encapsulate legacy Magnox swarf wastes.

  6. Compressive strength and hydrolytic stability of fly ash based geopolymers

    Directory of Open Access Journals (Sweden)

    Nikolić Irena

    2013-01-01

    Full Text Available The process of geopolymerization involves the reaction of solid aluminosilicate materials with highly alkaline silicate solution yielding an aluminosilicate inorganic polymer named geopolymer, which may be successfully applied in civil engineering as a replacement for cement. In this paper we have investigated the influence of synthesis parameters: solid to liquid ratio, NaOH concentration and the ratio of Na2SiO3/NaOH, on the mechanical properties and hydrolytic stability of fly ash based geopolymers in distilled water, sea water and simulated acid rain. The highest value of compressive strength was obtained using 10 mol dm-3 NaOH and at the Na2SiO3/NaOH ratio of 1.5. Moreover, the results have shown that mechanical properties of fly ash based geopolymers are in correlation with their hydrolytic stability. Factors that increase the compressive strength also increase the hydrolytic stability of fly ash based geopolymers. The best hydrolytic stability of fly ash based geopolymers was shown in sea water while the lowest stability was recorded in simulated acid rain. [Projekat Ministarstva nauke Republike Srbije, br. 172054 i Nanotechnology and Functional Materials Center, funded by the European FP7 project No. 245916

  7. Strength Performance of Blended Ash Based Geopolymer Mortar

    Science.gov (United States)

    Zahib, Zaidahtulakmal M.; Kamaruddin, Kartini; Saman, Hamidah M.

    2018-03-01

    Geopolymer is a based on inorganic alumino-silicate binder system. Geopolymeric materials are formed using materials that containing silica and aluminium such as fly ash and rice husk ash, which activated by alkaline solution. This paper presents the study on the effect of replacement of SSA in RHA based geopolymer, types of curing and different molarity of NaOH used on the strength of Sewage Sludge Ash (SSA) and Rice Husk Ash (RHA) based geopolymer mortar incorporating with three (3) different mix proportions. Based geopolymer mortar was synthesized from treated sewage sludge and rice husk undergoing incineration process in producing ashes, activated with sodium silicate and sodium hydroxide solution by ratio of 2.5:1 and solution to ash ratio of 1:1. Molarity of 8M and 10M NaOH were used. The percentages of SSA replacement were 0%, 10% and 20% by weight. Compressive strength was conducted at age 7, 14 and 28 days to see the development of strength with two curing regimes, which are air curing and oven curing (60°C for 24 hours). From the research conducted, the ultimate compressive strength (6.28MPa) was obtained at zero replacement of SSA taken at 28 days of oven curing with 10M of NaOH. This shows that RHA, which is rich in silica content is enough to enhance the strength of geopolymer mortar especially with high molarity of NaOH.

  8. Performance of steel wool fiber reinforced geopolymer concrete

    Science.gov (United States)

    Faris, Meor Ahmad; Abdullah, Mohd Mustafa Al Bakri; Ismail, Khairul Nizar; Muniandy, Ratnasamy; Ariffin, Nurliayana

    2017-09-01

    In this paper, performance of geopolymer concrete was studied by mixing of Class F fly ash from Manjung power station, Lumut, Perak, Malaysia with alkaline activator which are combination of sodium hydroxide and sodium silicate. Steel wool fiber were added into the geopolymer concrete as reinforcement with different weight percentage vary from 0 % - 5 %. Chemical compositions of Malaysian fly ash was first analyzed by using X-ray fluorescence. All geopolymer concrete reinforced with steel wool fiber with different weight percentage were tested in terms of density, workability, and compression. Result shows Malaysian fly ash identified by using XRF was class F. Density of geopolymer concrete close to density of OPC which is approximately 2400 kg/m3 and the density was increase gradually with the additions of steel fiber. However, the inclusions of steel fibers also shows some reduction to the workability of geopolymer concrete. Besides, the compressive strength was increased with the increasing of fibers addition until maximum of 18.6 % improvement at 3 % of steel fibers.

  9. TiO₂-Based Photocatalytic Geopolymers for Nitric Oxide Degradation.

    Science.gov (United States)

    Strini, Alberto; Roviello, Giuseppina; Ricciotti, Laura; Ferone, Claudio; Messina, Francesco; Schiavi, Luca; Corsaro, Davide; Cioffi, Raffaele

    2016-06-24

    This study presents an experimental overview for the development of photocatalytic materials based on geopolymer binders as catalyst support matrices. Particularly, geopolymer matrices obtained from different solid precursors (fly ash and metakaolin), composite systems (siloxane-hybrid, foamed hybrid), and curing temperatures (room temperature and 60 °C) were investigated for the same photocatalyst content (i.e., 3% TiO₂ by weight of paste). The geopolymer matrices were previously designed for different applications, ranging from insulating (foam) to structural materials. The photocatalytic activity was evaluated as NO degradation in air, and the results were compared with an ordinary Portland cement reference. The studied matrices demonstrated highly variable photocatalytic performance depending on both matrix constituents and the curing temperature, with promising activity revealed by the geopolymers based on fly ash and metakaolin. Furthermore, microstructural features and titania dispersion in the matrices were assessed by scanning electron microscopy (SEM) and energy dispersive X-ray (EDS) analyses. Particularly, EDS analyses of sample sections indicated segregation effects of titania in the surface layer, with consequent enhancement or depletion of the catalyst concentration in the active sample region, suggesting non-negligible transport phenomena during the curing process. The described results demonstrated that geopolymer binders can be interesting catalyst support matrices for the development of photocatalytic materials and indicated a large potential for the exploitation of their peculiar features.

  10. Toy models for wrapping effects

    International Nuclear Information System (INIS)

    Penedones, Joao; Vieira, Pedro

    2008-01-01

    The anomalous dimensions of local single trace gauge invariant operators in N = 4 supersymmetric Yang-Mills theory can be computed by diagonalizing a long range integrable Hamiltonian by means of a perturbative asymptotic Bethe ansatz. This formalism breaks down when the number of fields of the composite operator is smaller than the range of the Hamiltonian which coincides with the order in perturbation theory at study. We analyze two spin chain toy models which might shed some light on the physics behind these wrapping effects. One of them, the Hubbard model, is known to be closely related to N = 4 SYM. In this example, we find that the knowledge of the effective spin chain description is insufficient to reconstruct the finite size effects of the underlying electron theory. We compute the wrapping corrections for generic states and relate them to a Luscher like approach. The second toy models are long range integrable Hamiltonians built from the standard algebraic Bethe ansatz formalism. This construction is valid for any symmetry group. In particular, for non-compact groups it exhibits an interesting relation between wrapping interactions and transcendentality.

  11. Modèle de confinement pour les colonnes de section circulaire en béton armé confiné avec des enveloppes en polymère renforcé de fibres de carbone Confinement model for circular RC columns wrapped with CFRP composite

    Directory of Open Access Journals (Sweden)

    Benzaid R.

    2012-09-01

    Full Text Available Un programme experimental comprenant des essais sur 30 cylindres 160×320 mm a ete mene en vue de determiner le gain de resistance et de ductilite du beton confine par collage externe de tissu de polymere renforce de fibres de carbone (PRFC. Les variables etudiees sont la resistance a la compression du beton non confine f’co, le niveau de confinement, exprime par le nombre de plis de PRFC applique aux eprouvettes. La deformation circonferentielle a la rupture du composite PRF et l’feffet de la pression de confinement laterale effective de l’fenveloppe composite ont ete egalement etudies. Pour l’fensemble des specimens testes, l’faugmentation de la rigidite du confinement entraine a la fois une augmentation significative de la resistance a la compression axiale et de la ductilite des specimens en beton confine avec des PRFC par rapport aux specimens en beton non confine. Base sur les resultats experimentaux, un modele de confinement pratique est propose pour predire la resistance a la compression maximale du beton confine avec des materiaux composites (f’cc et la deformation axiale correspondante (εcc. The present paper deals with the analysis of experimental results, in terms of load carrying capacity and strains, obtained from tests on plain- and reinforced- concrete (RC cylinder, strengthened with external carbon-fiber-reinforced polymer (CFRP. The parameters considered are the number of composite layers, the compressive strength of unconfined concrete. The effective circumferential FRP failure strain and the effect of the effective lateral confining pressure were investigated. Totally thirty cylinders (160×320 mm were subjected to axial compression which includes control specimens. All the test specimens were loaded to failure in axial compression and the behaviour of the specimens in the axial and transverse directions was investigated. Test results shown that the CFRP wrap increases the strength and ductility of reinforced

  12. Durability of Bricks Coated with Red mud Based Geopolymer Paste

    Science.gov (United States)

    Singh, Smita; Basavanagowda, S. N.; Aswath, M. U.; Ranganath, R. V.

    2016-09-01

    The present study is undertaken to assess the durability of concrete blocks coated with red mud - fly ash based geopolymer paste. Concrete blocks of size 200 x 200 x 100mm were coated with geopolymer paste synthesized by varying the percentages of red mud and fly ash. Uncoated concrete blocks were also tested for the durability for comparison. In thermal resistance test, the blocks were subjected to 600°C for an hour whereas in acid resistance test, they were kept in 5% sulphuric acid solution for 4 weeks. The specimens were thereafter studied for surface degradation, strength loss and weight loss. Pastes with red mud percentage greater than 50% developed lot of shrinkage cracks. The blocks coated with 30% and 50% red mud paste showed better durability than the other blocks. The use of blocks coated with red mud - fly ash geopolymer paste improves the aesthetics, eliminates the use of plaster and improves the durability of the structure.

  13. Chemical composition and strength of dolomite geopolymer composites

    Science.gov (United States)

    Aizat, E. A.; Al Bakri, A. M. M.; Liew, Y. M.; Heah, C. Y.

    2017-09-01

    The chemical composition of dolomite and the compressive strength of dolomite geopolymer composites were studied. The both composites prepared with mechanical mixer manufactured by with rotor speed of 350 rpm and curing in the oven for 24 hours at 80˚C. XRF analysis showThe dolomite raw materials contain fewer amounts of Si and Al but high Ca in its composition. Dolomite geopolymer composites with 20M of NaOH shows greater and optimum compressive strength compared to dolomite geopolymer with other NaOH molarity. This indicated better interaction of dolomite raw material and alkaline activator need high molarity of NaOH in order to increase the reactivity of dolomite.

  14. Durability of Geopolymer Lightweight Concrete Infilled LECA in Seawater Exposure

    Science.gov (United States)

    Razak, R. A.; Abdullah, M. M. A. B.; Yahya, Z.; Hamid, M. S. A.

    2017-11-01

    This paper describes a development of lightweight concrete using lightweight expanded clay aggregate (LECA) in fly ash (FA) based geopolymer immersed in seawater. The objective of this research is to compare the performance of geopolymer concrete (GPC) with ordinary Portland cement (OPC) concrete infilled lightweight expanded clay aggregate (LECA) in seawater exposure. Geopolymer concrete is produced by using alkaline activator to activate the raw material, FA. The highest compressive strength of this study is 42.0 MPa at 28 days and 49.8 MPa at 60 days. The density for this concrete is in the range of 1580 kg/m3 to 1660 kg/m3. The result for water absorption is in the range of 6.82% to 14.72%. However, the test results of weight loss is in the range between 0.30% to 0.43%.

  15. POROUS MICROSTRUCTURE OF THE INTERFACIAL TRANSITION ZONE IN GEOPOLYMER COMPOSITES

    Directory of Open Access Journals (Sweden)

    Steinerová M.

    2013-12-01

    Full Text Available The study deals with a comparison of the differences in the structure, composition and micromechanical properties of a metakaolinite geopolymer composite matrix, inside and outside of the interfacial transition zone (ITZ with quartz grains of added silica sand. The microstructure is investigated by a measurement of the mercury porosimetry, microscopy and by a measurement in SEM and AFM, completed by Raman spectroscopy. Weaker mechanical properties, micropores in the ITZ, a higher concentration of Al atoms and hydroxyl groups than in the ambient matrix were detected. The water transport is probably the reason for the micropore formation, caused by disequilibrium in the course of solid-phase building from geopolymer dispersion.

  16. Immobilization of simulated radionuclide 133Cs{sup +} by fly ash-based geopolymer

    Energy Technology Data Exchange (ETDEWEB)

    Li, Qin; Sun, Zengqing; Tao, Dejing; Xu, Yan; Li, Peiming; Cui, Hao; Zhai, Jianping, E-mail: jpzhai@nju.edu.cn

    2013-11-15

    Highlights: • Fly ash-based geopolymer was used to immobilize 133Cs{sup +}, with cement as comparison. • Less Cs{sup +} was leached out from geopolymer in deionized water, acid and salt solutions. • Geopolymer showed more excellent acid resistance than cement blocks. • Geopolymer maintained superior mechanical strength to cement matrices. • Geopolymer showed good freeze–thaw and high-temperature performances. -- Abstract: The recent nuclear leak in Japan once again attracted people's attention to nuclear safety problems. Because of their poor thermal stability, those low-cost materials such as cement and asphalt cannot be used for the solidification of the radioactive wastes. In this work, the solidification behavior of 133Cs{sup +} by fly ash-based geopolymer was investigated. Leaching tests (carried out in deionized water, sulfuric acid and magnesium sulfate solutions) revealed that the geopolymer solidification had lower cumulative fraction leaching concentration (CFLC) of 133Cs{sup +} than that of cemented form. The thermal stability (high-temperature and freeze–thaw resistance) and acid-resistance of the geopolymer were also both better than that of cement. The geopolymer solidification block can acquire a compressive strength up to 30 MPa after 2 h calcination at 1000 °C. The morphology and mineral phases of the geopolymer and the geopolymer solidification block were characterized by SEM and XRD, and EDX analysis indicated that most of Cs associated with the amorphous geopolymer gel. These results gave encouragement for the idea that the fly ash-based geopolymer could be used as a low-cost and high-efficiency material for the immobilization of radioactive wastes.

  17. ''Geopolymers": same basic chemistry, different microstructures

    Directory of Open Access Journals (Sweden)

    Palomo, A.

    2004-09-01

    Full Text Available The present paper describes the effect of certain working variables on the microstructural evolution of oven-dried, alkali-activated fly ash. The results show that the main reaction product in the activation process (in all the systems studied is an amorphous aluminosilicate gel with a three-dimensional structure. Nonetheless, the type and concentration of the activator used as well as the natural ageing of the materials and origin of the prime materials were also found to have a substantial impact on microstructural development in the "geopolymers " synthesised, particularly from the morphological standpoint.

    Este trabajo describe el efecto de determinadas variables de trabajo sobre la evolución microestructural de sistemas basados en cenizas volantes térmica y alcalínamente activadas. Los resultados demuestran que el principal producto de reacción en el proceso de activación (en todos los sistemas estudiados es un aluminosilicato amorfo con características de gel y con estructura tridimensional. Sin embargo el tipo y la concentración del activador usado, así como el envejecimiento natural de los materiales y el origen diferente de las materias primas han demostrado también ser variables que afectan sustancialmente al desarrollo microestructural de los ''geopolimeros" sintetizados, especialmente desde el punto de vista morfológico.

  18. Alkali-activated fly ash-based geopolymers with zeolite or bentonite as additives

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Mingyu; Zhu, Xiaomin; Long, Fumei [Nanchang University, Nanchang (China). College of Civil Engineering

    2009-11-15

    Geopolymers were synthesized by using fly ash as the main starting material, zeolite or bentonite as supplementary materials, and NaOH and CaO together as activator. An orthogonal array testing protocol was used to analyze the influence of the mix proportion on the properties of the geopolymers. The results indicate that the concentration of NaOH solution and the CaO content play an important role on the strength of the materials. Especially, with zeolite as additive, the fly ash-based geopolymer shows the highest strength and the best sulfate resistance. Infrared spectroscopy, X-ray, and SEM-EDX demonstrate that supplementary zeolite may involve the process of geopolymerization to form a stable zeolitic structure and improve the properties of the geopolymer. Bentonite simply acts as a filler to make the geopolymer more compact, but shows no improvement on the compositions and the microstructures of the geopolymer.

  19. Geopolymers and their potential applications in the nuclear waste management field. A bibliographical study

    International Nuclear Information System (INIS)

    Cantarel, Vincent; Motooka, Takafumi; Yamagishi, Isao

    2017-06-01

    After a necessary decay time, the zeolites used for the water decontamination will eventually be conditioned for their long-term storage. Geopolymer is considered as a potential matrix to manage radioactive cesium and strontium containing waste. For such applications, a correct comprehension of the binder structure, its macroscopic properties, its interactions with the waste and the physico-chemical phenomena occurring in the wasteform is needed to be able to judge of the soundness and viability of the material. Although the geopolymer is a young binder, a lot of research has been carried out over the last fifty years and our understanding of this matrix and its potential applications is progressing fast. This review aims at gathering the actual knowledge on geopolymer studies about geopolymer composites, geopolymer as a confinement matrix for nuclear wastes and geopolymer under irradiation. This information will finally provide guidance for the future studies and experiments. (author)

  20. Geopolymer Composites for Potential Applications in Cultural Heritage

    Directory of Open Access Journals (Sweden)

    Laura Ricciotti

    2017-12-01

    Full Text Available A new class of geopolymer composites, as materials alternative to traditional binders, was synthesized and its potentialities as restoration material in Cultural Heritage has been explored. This material has been prepared through a co-reticulation reaction in mild conditions of a metakaolin-based geopolymer inorganic matrix and a commercial epoxy resin. The freshly prepared slurry displays a consistency, workability and thixotropic behavior that make it suitable to be spread on different substrates in restoration, repair and reinforcement actions, even on walls and ceilings. Applicability and compatibility tests on tuff and concrete substrates were carried out and the microstructure of the samples in correspondence of the transition zone was analyzed by means of scanning electron microscope (SEM observations and energy dispersive spectroscopy (EDS mapping. Our studies pointed out the formation of a continuous phase between the geopolymer composite and tuff and concrete substrates, highlighting a high compatibility of the geopolymer binder with different kinds of materials. These features indicate a large potential for applications of these materials in Cultural Heritage.

  1. Self-compacting geopolymer concrete-a review

    Science.gov (United States)

    Ukesh Praveen, P.; Srinivasan, K.

    2017-11-01

    In this construction world, Geopolymer concrete is a special concrete which doesn’t requires the Ordinary Portland Cement and also reduces the emission of carbon-dioxide. The Geopolymer Concrete is made up of industrial by-products (which contains more Silica and Alumina) and activated with the help of Alkaline solution (combination of sodium hydroxide & sodium silicate or potassium hydroxide & potassium silicate). The high viscosity nature of Geopolymer Concrete had the ability to fail due to lack of compaction. In improvising the issue, Self Compacting Geopolymer Concrete has been introduced. The SCGC doesn’t require any additional compaction it will flow and compacted by its own weight. This concrete is made up of industrial by-products like Fly ash, GGBFS and Silica Fume and activated with alkaline solution. The earlier research was mostly on Fly ash based SCGC. In few research works Fly ash was partially replaced with GGBS and Silica Fume. They evaluated the compressive strength of concrete with varying molarities of NaOH; curing time and curing temperature. The flexural behaviour of the concrete also examined. The Fly ash based SCGC was got high compressive strength in heat curing as well as low compressive strength in ambient curing. The presence of GGBS improves the strength in ambient curing. For aiming the high strength in ambient curing Fly ash will be completely replace and examine with different mineral admixtures.

  2. Development of Abaca Fiber-reinforced Foamed Fly Ash Geopolymer

    Directory of Open Access Journals (Sweden)

    Janne Pauline S. Ngo

    2018-01-01

    Full Text Available The growing environmental and economic concerns have led to the need for more sustainable construction materials. The development of foamed geopolymer combines the benefit of reduced environmental footprint and attractive properties of geopolymer technology with foam concrete’s advantages of being lightweight, insulating and energy-saving. In this study, alkali-treated abaca fiber-reinforced geopolymer composites foamed with H2O2 were developed using fly ash as the geopolymer precursor. The effects of abaca fiber loading, foaming agent dosage, and curing temperature on mechanical strength were evaluated using Box-Behken design of experiment with three points replicated. Volumetric weight of samples ranged from 1966 kg/m3 to 2249 kg/m3. Measured compressive strength and flexural ranged from 19.56 MPa to 36.84 MPa, and 2.41 MPa to 6.25 MPa, respectively. Results suggest enhancement of compressive strength by abaca reinforcement and elevated temperature curing. Results, however, indicate a strong interaction between curing temperature and foaming agent dosage, which observably caused the composite’s compressive strength to decline when simultaneously set at high levels. Foaming agent dosage was the only factor detected to significantly affect flexural strength.

  3. Geopolymers as potential repair material in tiles conservation

    Science.gov (United States)

    Geraldes, Catarina F. M.; Lima, Augusta M.; Delgado-Rodrigues, José; Mimoso, João Manuel; Pereira, Sílvia R. M.

    2016-03-01

    The restoration materials currently used to fill gaps in historical architectural tiles (e.g. lime or organic resin pastes) usually show serious drawbacks in terms of compatibility, effectiveness or durability. The existing solutions do not fully protect Portuguese faïence tiles ( azulejos) in outdoor conditions and frequently result in further deterioration. Geopolymers can be a potential solution for tile lacunae infill, given the chemical-mineralogical similitude to the ceramic body, and also the durability and versatile range of physical properties that can be obtained through the manipulation of their formulation and curing conditions. This work presents and discusses the viability of the use of geopolymeric pastes to fill lacunae in tiles or to act as "cold" cast ceramic tile surrogates reproducing missing tile fragments. The formulation of geopolymers, namely the type of activators, the alumino-silicate source, the quantity of water required for adequate workability and curing conditions, was studied. The need for post-curing desalination was also considered envisaging their application in the restoration of outdoor historical architectural tiles frequently exposed to adverse environmental conditions. The possible advantages and disadvantages of the use of geopolymers in the conservation of tiles are also discussed. The results obtained reveal that geopolymers pastes are a promising material for the restoration of tiles, when compared to other solutions currently in use.

  4. Advances in 27Al MAS NMR studies of geopolymers

    Czech Academy of Sciences Publication Activity Database

    Brus, Jiří; Abbrent, Sabina; Kobera, Libor; Urbanová, Martina; Cuba, P.

    2016-01-01

    Roč. 88, č. 2016 (2016), s. 79-147 ISSN 0066-4103 R&D Projects: GA ČR(CZ) GA13-24155S; GA MŠk(CZ) LO1507 Institutional support: RVO:61389013 Keywords : geopolymers * aluminosilicates * solid-state NMR Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.600, year: 2016

  5. The Experience on Geopolymer Technology in Semi-Industrial Production

    Czech Academy of Sciences Publication Activity Database

    Boura, P.; Ertl, Z.; Hanzlíček, Tomáš; Perná, Ivana

    2012-01-01

    Roč. 2, č. 4 (2012), s. 300-305 ISSN 2161-6221 Institutional research plan: CEZ:AV0Z30460519 Keywords : geopolymer * semi-industrial * production Subject RIV: JI - Composite Materials http://davidpublishing.org/journals_show_abstract.html?5272-0

  6. Synthesis of geopolymer from biomass-coal ash blends

    Science.gov (United States)

    Samadhi, Tjokorde Walmiki; Wulandari, Winny; Prasetyo, Muhammad Iqbal; Fernando, Muhammad Rizki; Purbasari, Aprilina

    2017-09-01

    Geopolymer is an environmentally attractive Portland cement substitute, owing to its lower carbon footprint and its ability to consume various aluminosilicate waste materials as its precursors. This work describes the development of geopolymer formulation based on biomass-coal ash blends, which is predicted to be the prevalent type of waste when biomass-based thermal energy production becomes mainstream in Indonesia. The ash blends contain an ASTM Class F coal fly ash (FA), rice husk ash (RHA), and coconut shell ash (CSA). A mixture of Na2SiO3 and concentrated KOH is used as the activator solution. A preliminary experiment identified the appropriate activator/ash mass ratio to be 2.0, while the activator Na2SiO3/KOH ratio varies from 0.8 to 2.0 with increasing ash blend Si/Al ratio. Both non-blended FA and CSA are able to produce geopolymer mortars with 7-day compressive strength exceeding the Indonesian national SNI 15-2049-2004 standard minimum value of 2.0 MPa stipulated for Portland cement mortars. Ash blends have to be formulated with a maximum RHA content of approximately 50 %-mass to yield satisfactory 7-day strength. No optimum ash blend composition is identified within the simplex ternary ash blend compositional region. The strength decreases with Si/Al ratio of the ash blends due to increasing amount of unreacted silicate raw materials at the end of the geopolymer hardening period. Overall, it is confirmed that CSA and blended RHA are feasible raw materials for geopolymer production..

  7. Fracture behaviour of heat cured fly ash based geopolymer concrete

    International Nuclear Information System (INIS)

    Sarker, Prabir K.; Haque, Rashedul; Ramgolam, Karamchand V.

    2013-01-01

    Highlights: ► Fly ash geopolymer (GPC) can help reduce carbon footprint of concrete. ► Fracture behaviour of GPC as compared to OPC concrete was studied. ► Fracture energy of GPC was similar to that of OPC concrete. ► GPC showed higher fracture toughness than OPC concrete. ► Higher bond strength resulted in higher crack resistance of GPC. -- Abstract: Use of fly ash based geopolymer as an alternative binder can help reduce CO 2 emission of concrete. The binder of geopolymer concrete (GPC) is different from that of ordinary Portland cement (OPC) concrete. Thus, it is necessary to study the effects of the geopolymer binder on the behaviour of concrete. In this study, the effect of the geopolymer binder on fracture characteristics of concrete has been investigated by three point bending test of RILEM TC 50 – FMC type notched beam specimens. The peak load was generally higher in the GPC specimens than the OPC concrete specimens of similar compressive strength. The failure modes of the GPC specimens were found to be more brittle with relatively smooth fracture planes as compared to the OPC concrete specimens. The post-peak parts of the load–deflection curves of GPC specimens were steeper than that of OPC concrete specimens. Fracture energy calculated by the work of fracture method was found to be similar in both types of concrete. Available equations for fracture energy of OPC concrete yielded conservative estimations of fracture energy of GPC. The critical stress intensity factor of GPC was found to be higher than that of OPC concrete. The different fracture behaviour of GPC is mainly because of its higher tensile strength and bond strength than OPC concrete of the same compressive strength.

  8. Effects of delayed wrapping of baled silage

    Science.gov (United States)

    Use of baled silage allows greater flexibility for harvest management when weather does not allow drying and harvesting forage as dry hay. However, timely wrapping on the day of baling can be difficult if significant numbers of bales need to be wrapped, or if a mechanical breakdown occurs. Researc...

  9. Microstructural analysis of geopolymer developed from wood fly ash, post-mortem doloma refractory and metakaolin

    International Nuclear Information System (INIS)

    Moura, Jailes de Santana; Mafra, Marcio Paulo de Araujo; Rabelo, Adriano Alves; Fagury, Renata Lilian Ribeiro Portugal; Fagury Neto, Elias

    2016-01-01

    Geopolymers are one of the widely discussed topics of materials science in recent times due to its vast potential as an alternative binder material to cement. This work aimed to evaluate the microstructure of geopolymers developed from wood fly ash, post-mortem doloma refractory and metakaolin. A preliminary study has been completed and achieved significant results compressive strength: the best formulation of geopolymer paste obtained approximately 25 MPa. Microstructural analysis by scanning electron microscopy, the geopolymer paste, allowed to verify the homogeneity, distribution of components, and providing evidence of raw materials that do not respond if there was crystalline phase, porosity and density of the structure. (author)

  10. Experimental Evaluation of Geopolymer and ‘Lunamer’ Binders as Radioactive Shielding Materials for Space Applications

    Data.gov (United States)

    National Aeronautics and Space Administration — Geopolymers are inorganic cementitious binders produced by polymeric reaction between an aluminosilica rich material and an alkali metal hydroxide/silicate liquid,...

  11. Effect of glass microfibre addition on the mechanical performances of fly ash-based geopolymer composites

    Directory of Open Access Journals (Sweden)

    Thamer Alomayri

    2017-09-01

    Full Text Available In the present study, various amounts of glass microfibres were introduced into a geopolymer for reinforcement purposes. The influence of these microfibres on the performance of the geopolymer composites was investigated. Results show that the appropriate addition of glass microfibres can improve the mechanical properties of geopolymer composites. In particular, the flexural strength, flexural modulus and impact strength increase at an optimum fibre content of 2 wt%. Further, adding glass microfibres to a plain geopolymer matrix has a significant effect on the pre-cracking behaviour. It substantially enhances the post-cracking response.

  12. Earthquake Response of Reinforced Concrete Building Retrofitted with Geopolymer Concrete and X-shaped Metallic Damper

    Science.gov (United States)

    Madheswaran, C. K.; Prakash vel, J.; Sathishkumar, K.; Rao, G. V. Rama

    2017-06-01

    A three-storey half scale reinforced concrete (RC) building is fixed with X-shaped metallic damper at the ground floor level, is designed and fabricated to study its seismic response characteristics. Experimental studies are carried out using the (4 m × 4 m) tri-axial shake-table facility to evaluate the seismic response of a retrofitted RC building with open ground storey (OGS) structure using yielding type X-shaped metallic dampers (also called as Added Damping and Stiffness-ADAS elements) and repairing the damaged ground storey columns using geopolymer concrete composites. This elasto-plastic device is normally incorporated within the frame structure between adjacent floors through chevron bracing, so that they efficiently enhance the overall energy dissipation ability of the seismically deficient frame structure under earthquake loading. Free vibration tests on RC building without and with yielding type X-shaped metallic damper is carried out. The natural frequencies and mode shapes of RC building without and with yielding type X-shaped metallic damper are determined. The retrofitted reinforced concrete building is subjected to earthquake excitations and the response from the structure is recorded. This work discusses the preparation of test specimen, experimental set-up, instrumentation, method of testing of RC building and the response of the structure. The metallic damper reduces the time period of the structure and displacement demands on the OGS columns of the structure. Nonlinear time history analysis is performed using structural analysis package, SAP2000.

  13. KVP meter errors induced by plastic wrap

    International Nuclear Information System (INIS)

    Jefferies, D.; Morris, J.W.; White, V.P.

    1991-01-01

    The purpose of this study was to determine whether erroneous kVp meter readings, induced by plastic wrap, affected the actual kVp (output) of a dental X-ray machine. To evaluate the effect of plastic wrap on dental X-ray machine kVp meters, a radiation output device was used to measure output in mR/ma.s. An intraoral dental X-ray unit (S.S. White Model number-sign 90W) was used to make the exposures. First, the kVp meter was not covered with plastic wrap and output readings were recorded at various kVp settings with the milliamperage and time held constant. Secondly, the same kVp settings were selected before the plastic wrap was placed. Milliamperage and time were again held to the same constant. The X-ray console was then covered with plastic wrap prior to measuring the output for each kVp. The wrap possessed a static charge. This charge induced erroneous kVp meter readings. Out-put readings at the various induced kVp settings were then recorded. A kVp of 50 with no wrap present resulted in the same output as a kVp of 50 induced to read 40 or 60 kVp by the presence of wrap. Similar results were obtained at other kVp settings. This indicates that the plastic wrap influences only the kVp meter needle and not the actual kilovoltage of the X-ray machine. Dental X-ray machine operators should select kVp meter readings prior to placing plastic wrap and should not adjust initial settings if the meter is deflected later by the presence of wrap. The use of such a procedure will result in proper exposures, fewer retakes, and less patient radiation. If plastic wrap leads to consistent exposure errors, clinicians may wish to use a 0.5% sodium hypochlorite disinfectant as an alternative to the barrier technique

  14. Wrapping Our Brains around Sustainability

    Directory of Open Access Journals (Sweden)

    Mary Ann Curran

    2009-03-01

    Full Text Available As many of us begin to embrace the concept of sustainability, we realize that it is not simply something that we ‘do.’ Rather, sustainability is a destination that we aspire to reach with the selection of the sustainable pathways that we choose as we proceed along the journey. We are embarking on a new journey with the creation of Sustainability, an on-line, open access journal. As stated on the journal’s website, Sustainability is an international and cross-disciplinary scholarly journal of environmental, cultural, economic and social sustainability of human beings, which provides an advanced forum for studies that are related to sustainability and sustainable development. To genuinely wrap our brains around the impact that our actions have on the sustainability of our planet, we must first understand something of the big picture and have a firm grasp of the terminology. To help further clarify the elusive term ‘sustainability,’ without attempting to provide an exact definition, this paper outlines various, inter-related concepts and basic practices and approaches that are being used in the name of sustainability, including: traditional end-of-pipe control strategies, life cycle, environmental sustainability, urban sustainability, industrial ecology, business sustainability, sustainable supply chain systems, sustainability indicators and metrics, green chemistry and green engineering, design for the environment, sustainable buildings, eco-tourism, and renewable and sustainable energy and fuels.

  15. An Investigation of Bond Strength of Reinforcing Bars in Fly Ash and GGBS Based Geopolymer Concrete

    Directory of Open Access Journals (Sweden)

    Boopalan C.

    2017-01-01

    Full Text Available Geopolymers are amorphous aluminosilicate materials. Geopolymers are binders formed by alkali activation of Geopolymer Source Materials (GSM using an alkaline activator solution. Concretes made using Geopolymer binders are excellent alternative to the Ordinary Portland Cement concretes from strength, durability, and ecological considerations. Especially, usage of industrial waste materials such as Fly Ash and Slags as GSMs considerably lower the carbon footprint of concrete and mitigate the damage due to the unscientific dumping/disposal of these materials. To use the Geopolymer concrete (GPC for reinforced structural members, the composite action of reinforcing bars with Geopolymer concrete i.e. the bond behaviour should be well understood. This paper describes the bond behaviour of 12mm and 16mm dia. bars embedded in Fly ash and GGBS based Geopolymer concrete and conventional Portland Pozzolana cement concrete specimens investigated using the pull-out tests as per Indian Standard Code IS:2770(Part-I; the bond stresses and corresponding slips were found out. The bond stress increased with increase in compressive strength. The peak bond stress was found to be 4.3 times more than the design bond stress as per IS:456-2000. The Geopolymer concretes possess higher bond strength compared to the conventional cement concretes.

  16. The influence of Pb addition on the properties of fly ash-based geopolymers.

    Science.gov (United States)

    Nikolić, Violeta; Komljenović, Miroslav; Džunuzović, Nataša; Miladinović, Zoran

    2018-05-15

    Preventing or reducing negative effects on the environment from the waste landfilling is the main goal defined by the European Landfill Directive. Generally geopolymers can be considered as sustainable binders for immobilization of hazardous wastes containing different toxic elements. In this paper the influence of addition of high amount of lead on structure, strength, and leaching behavior (the effectiveness of Pb immobilization) of fly ash-based geopolymers depending on the geopolymer curing conditions was investigated. Lead was added during the synthesis of geopolymers in the form of highly soluble salt - lead-nitrate. Structural changes of geopolymers as a result of lead addition/immobilization were assessed by means of XRD, SEM/EDS, and 29 Si MAS NMR analysis. Investigated curing conditions significantly influenced structure, strength and leaching behavior of geopolymers. High addition of lead caused a sizeable decrease in compressive strength of geopolymers and promoted formation of aluminum-deficient aluminosilicate gel (depolymerization of aluminosilicate gel), regardless of the curing conditions investigated. According to the EUWAC limitations, 4% of lead was successfully immobilized by fly ash-based geopolymers cured for 28 days in a humid chamber at room temperature. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. Solidification/stabilisation of liquid oil waste in metakaolin-based geopolymer

    Energy Technology Data Exchange (ETDEWEB)

    Cantarel, V.; Nouaille, F.; Rooses, A.; Lambertin, D., E-mail: david.lambertin@cea.fr; Poulesquen, A.; Frizon, F.

    2015-09-15

    Highlights: • Formulation with 20 vol.% of oil in a geopolymer have been successful tested. • Oil waste is encapsulated as oil droplets in metakaolin-based geopolymer. • Oil/geopolymer composite present good mechanical performance. • Carbon lixiviation of oil/geopolymer composite is very low. - Abstract: The solidification/stabilisation of liquid oil waste in metakaolin based geopolymer was studied in the present work. The process consists of obtaining a stabilised emulsion of oil in a water-glass solution and then adding metakaolin to engage the setting of a geopolymer block with an oil emulsion stabilised in the material. Geopolymer/oil composites have been made with various oil fraction (7, 14 and 20 vol.%). The rigidity and the good mechanical properties have been demonstrated with compressive strength tests. Leaching tests evidenced the release of oil from the composite material is very limited whereas the constitutive components of the geopolymer (Na, Si and OH{sup −}) are involved into diffusion process.

  18. A comparative study of geopolymers synthesized from OXY-combustion and chemical looping combustion bottom ashes

    CSIR Research Space (South Africa)

    Nkuna, CN

    2017-04-01

    Full Text Available silicate (Na2SiO2) and sodium hydroxide solutions (5M, 10M and 15M) and the pastes were cured at 60°C for 10days. The properties of the geopolymers were characterized using: TGA, FTIR and SEM-EDX techniques. TGA analysis showed that FBC geopolymer with 5M...

  19. Incorporation of cement bypass flue dust in fly ash and blast furnace slag-based geopolymer

    Directory of Open Access Journals (Sweden)

    Mohamed E. Sultan

    2018-06-01

    Full Text Available This work utilizes cement kiln dust in fly ash and blast furnace slag-based geopolymer. Geopolymer cement was produced using different compositions of ground, granulated blast furnace slag with fly ash and cement bypass flue dust. Crystalline sodium metasilicate pentahydrate was used as an activator at 10, 15 and 20% (by weight of the geopolymer source materials. The geopolymer is formed in the solid state like ordinary Portland cement. The mechanical and chemical properties of the geopolymeric materials were examined. Measuring of mechanical properties by compressive strength of the hardened geopolymer pastes at different curing ages; microstructure was evaluated by X-ray diffraction (XRD and scanning electron microscope (SEM; thermal properties were estimated by thermogravimetry analysis (TGA and derivative thermogravimetric analysis (DTG. The results indicate that the compressive strength of the geopolymer pastes is increased with higher Na2SiO3.5H2O content. The geopolymeric properties were enhanced by higher pH, which helps in the dissolution of geopolymer source materials during geopolymerization. SEM showed that mixes containing 15 and 20% sodium metasilicate had more compact and dense structures. On the other hand, GGBFS mix (G-20 exhibits more hydration and geopolymeric products during TGA/DTG compared with other mixes which contain FA with/without GGBFS. Keywords: Cement bypass flue dust, Geopolymer, Ground granulated blast furnace, Fly ash

  20. Study on The Geopolymer Concrete Properties Reinforced with Hooked Steel Fiber

    Science.gov (United States)

    Abdullah, M. M. A. B.; Tahir, M. F. M.; Tajudin, M. A. F. M. A.; Ekaputri, J. J.; Bayuaji, R.; Khatim, N. A. M.

    2017-11-01

    In this research, Class F fly ash and a mixture of alkaline activators and different amount of hooked steel fiber were used for preparing geopolymer concrete. In order to analyses the effect of hooked steel fiber on the geopolymer concrete, the analysis such as chemical composition of fly ash, workability of fresh geopolymer, water absorption, density, compressive strength of hardened geopolymer concrete have been carried out. Mixtures were prepared with fly ash to alkaline liquid ratio of 2.0 with hooked steel fibers were added to the mix with different amounts which are 1%, 3%, 5% and 7% by the weight of the concrete. Experimental results showed that the compressive strength of geopolymer concrete increases as the hooked steel fibers increases. The optimum compressive strength obtained was up to 87.83 MPa on the 14th day. The density of geopolymer concrete are in the range between 2466 kg/m3 to 2501 kg/m3. In addition, the workability value of geopolymer without hooked steel fibers is 100 mm while the workability value of geopolymer with hooked steel fibers are between 60 mm to 30 mm.

  1. Some Durability Aspects of Ambient Cured Bottom Ash Geopolymer Concrete

    Directory of Open Access Journals (Sweden)

    Saravanakumar R.

    2017-09-01

    Full Text Available The present study examines some durability aspects of ambient cured bottom ash geopolymer concrete (BA GPC due to accelerated corrosion, sorptivity, and water absorption. The bottom ash geopolymer concrete was prepared with sodium based alkaline activators under ambient curing temperatures. The sodium hydroxide used concentration was 8M. The performance of BA GPC was compared with conventional concrete. The test results indicate that BA GPC developes a strong passive layer against chloride ion diffusion and provides better protection against corrosion. Both the initial and final rates of water absorption of BA GPC were about two times less than those of conventional concrete. The BA GPC significantly enhanced performance over equivalent grade conventional concrete (CC.

  2. Rheological characterization of geopolymer binder modified by organic resins

    Science.gov (United States)

    Cekalová, M.; Kovárík, T.; Rieger, D.

    2017-01-01

    The purpose of this study is going to investigate properties of alkali-activated powder (calcined kaoilinitic clay and granulated blast furnace slag) prepared as a geopolymer paste and modified by various amount of organic resin. Hybrid organic-inorganic binders were prepared as a mix of organic resin and geopolymer inorganic paste under vacuum conditions. The process of solidification was investigated by measurements of storage (G’) and loss modulus ( G’) in torsion. The measurement was conducted in oscillatory mode by constant strain of 0.01 %. This strain is set in linear visco-elastic region for minimization influence of paste structure. The effect of organic resin is presented and determined by changes of viscosity (‘n*), modules in torsion and tangent of loss angle (tan 8). Results indicate that addition of organic resin significantly affects the initial viscosity and hardening kinetics.

  3. Hydrogen formation under gamma and heavy ions irradiation of geopolymers

    International Nuclear Information System (INIS)

    Chupin, F.; Dannoux-Papin, A.; D'Espinose de Lacaillerie, J.B.; Ngono Ravache, Y.

    2015-01-01

    This study examines the behavior under irradiation of geo-polymer which is not yet well known and attempts to highlight the importance of water radiolysis. For their use as embedding matrices, stability under ionizing radiation as well as low hydrogen gas released must be demonstrated. Different formulations of geo-polymers have been irradiated either with γ-rays ( 60 Co sources) or 75 MeV 36 Ar ions beams and the production of hydrogen released has been quantified. This paper presents the results of gas analysis in order to identify important structural parameters that influence confined water radiolysis. Indeed, a correlation between pore size, water content on one side, and the hydrogen production radiolytic yield (G(H 2 )) on the other side, has been demonstrated. For the 75 MeV 36 Ar ions irradiation, the effect of porosity has not been well emphasized. For both, the results have revealed the water content influence. (authors)

  4. Lightweight geopolymer composites as structural elements with improved insulation capacity

    Directory of Open Access Journals (Sweden)

    Kakali Glikeria

    2018-01-01

    Full Text Available This study concerns the development of lightweight fly ash based geopolymers which can be applied as alternatives to the traditional lightweight concrete. Different kinds of expanded polystyrene were used as lightweight agents. The results showed that lightweight geopolymers were successfully prepared, exhibiting compressive strength and density in the range 7.70 – 29.57 MPa and 0.97 – 1.57 g/cm3, respectively. The product containing 3% w/w of commercial expanded polystyrene possesses low thermal conductivity (0.16 W/mK combined with sufficient mechanical strengths (11 MPa, excellent stability and fire resistance while its water absorption is comparable to that of conventional construction materials (cement mortars, concrete.

  5. Method of Construction for Geopolymer Soil Stabilized Platforms

    Science.gov (United States)

    2017-12-20

    Department of Defense. Vickers, L., A. van Riessen, and W.D.A. Rickard. 2015. Fire - Resistant Geopolymers: Role of Fibres and Fillers to Enhance Thermal...tension fabric structures. However, this type of structure requires a solid base, which is often made of concrete and when left behind, it creates real...such as engineered tension fabric structures. The tensioned fabric and the support frame form a single integral struc- tural unit that is low in cost

  6. Experimental Study on Flexural Strength of Reinforced Geopolymer Concrete Beams

    OpenAIRE

    Khoa Tan Nguyen; Tuan Anh Le; Kihak Lee

    2016-01-01

    This paper presents the flexural response of Reinforced Geopolymer Concrete (RGPC) beams. A commercial finite element (FE) software ABAQUS has been used to perform a structural behavior of RGPC beams. Using parameters such: stress, strain, Young’s modulus, and Poisson’s ratio obtained from experimental results, a beam model has been simulated in ABAQUS. The results from experimental tests and ABAQUS simulation were compared. Due to friction forces at the supports and loading rollers; slip occ...

  7. COBRA-IV wire wrap data comparisons

    International Nuclear Information System (INIS)

    Donovan, T.E.; George, T.L.; Wheeler, C.L.

    1979-02-01

    Thermal hydraulic analyses of hexagonally packed wire-wrapped fuel assemblies are complicated by the induced crossflow between adjacent subchannels. The COBRA-IV computer code simultaneously solves the hydrodynamics and thermodynamics of fuel assemblies. The modifications and the results are presented which are predicted by the COBRA-IV calculation. Comparisons are made with data measured in five experimental models of a wire-wrapped fuel assembly

  8. Flow properties of MK-based geopolymer pastes. A comparative study with standard Portland cement pastes.

    Science.gov (United States)

    Favier, Aurélie; Hot, Julie; Habert, Guillaume; Roussel, Nicolas; d'Espinose de Lacaillerie, Jean-Baptiste

    2014-02-28

    Geopolymers are presented in many studies as alternatives to ordinary Portland cement. Previous studies have focused on their chemical and mechanical properties, their microstructures and their potential applications, but very few have focussed on their rheological behaviour. Our work highlights the fundamental differences in the flow properties, which exist between geopolymers made from metakaolin and Ordinary Portland Cement (OPC). We show that colloidal interactions between metakaolin particles are negligible and that hydrodynamic effects control the rheological behaviour. Metakaolin-based geopolymers can then be described as Newtonian fluids with the viscosity controlled mainly by the high viscosity of the suspending alkaline silicate solution and not by the contribution of direct contacts between metakaolin grains. This fundamental difference between geopolymers and OPC implies that developments made in cement technology to improve rheological behaviour such as plasticizers will not be efficient for geopolymers and that new research directions need to be explored.

  9. Effect on mechanical properties of glass reinforced epoxy (GRE) pipe filled with different geopolymer filler molarity for piping application

    Science.gov (United States)

    Hashim, M. F. Abu; Abdullah, M. M. A.; Ghazali, C. M. R.; Hussin, K.; Binhussain, M.

    2017-04-01

    This study investigated the use of a novel white clay geopolymer as a filler to produce high strength glass reinforced epoxy pipe. It was found that using white clay geopolymer as filler gives better compressive strength to the glass reinforced epoxy pipe. The disadvantages of current glass reinforced epoxy pipes such low compressive strength which can be replaced by the composite pipes. Geopolymerization is an innovative technology that can transform several aluminosilicate materials into useful products called geopolymers or inorganic polymers. A series of glass reinforced epoxy pipe and glass reinforced epoxy pipe filled with 10 - 40 weight percentages white clay geopolymer filler with 4 Molarity and 8 Molarity were prepared. Morphology of white clay geopolymer filler surface was indicates using scanning electron microscopy. The additions of white clay geopolymer filler for both 4 Molarity and 8 Molarity show higher compressive strength than glass reinforced epoxy pipe without any geopolymer filler. The compressive test of these epoxy geopolymer pipe samples was determined using Instron Universal Testing under compression mode. Nonetheless, the compressive strength of glass reinforced epoxy pipe with white clay geopolymer filler continues to drop when added to 40 wt% of the geopolymer filler loading for both 4 Molarity and 8 Molarity. These outcomes showed that the mixing of geopolymer materials in epoxy system can be attained in this research.

  10. Physicochemical characterization of pulverized phyllite rocks to geopolymer resin synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Melo, L.G.A. [Instituto Militar de Enegenharia (IME), Rio de Janeiro, RJ (Brazil); Pires, E.F.C. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Pereira, R.A.; Silva, F.J. [Instituto Federal de Educacao, Ciencia e Tecnologia do Rio de Raneiro (IFRJ), RJ (Brazil)

    2016-07-01

    Full text: Geopolymeric materials have common properties considered unique, such as: early-high compressive strength, durability, high chemical resistance to acids and sulfates attacks, ability to immobilize toxic and radioactive compounds, low porosity, low permeability, and resistance to high temperatures. Together with its environmental benefits, such as low energy consumption and low carbon dioxide emissions during production, these inorganic polymers are strategic materials for sustainable development and a good alternative to Portland cement. The main objective for introducing alternative materials is to lower the associated costs of its industrial process. Thus, the use of phyllite as the geopolymer precursor, is encouraged by its abundance, low cost, and the fact that it already is applied to the ceramic industries as kaolin substitute. This paper presents a physical characterization using TEM, SEM, XRD and XRF techniques of two pulverized phyllite rocks used as geopolymer precursors for refractory applications. It was found that both phyllite rocks studied have a high quartz content of approximately 50% that can be explored as 'filler' function in the microstructure, which stabilizes residual tensions after curing. Kaolinite and muscovite minerals are present up to 40% and are responsible for the high strengths in the geopolymer resins, as determined by compressive strength tests. (author)

  11. A novel method to produce dry geopolymer cement powder

    Directory of Open Access Journals (Sweden)

    H.A. Abdel-Gawwad

    2016-04-01

    Full Text Available Geopolymer cement is the result of reaction of two materials containing aluminosilicate and concentrated alkaline solution to produce an inorganic polymer binder. The alkali solutions are corrosive and often viscous solutions which are not user friendly, and would be difficult to use for bulk production. This work aims to produce one-mix geopolymer mixed water that could be an alternative to Portland cement by blending with dry activator. Sodium hydroxide (SH was dissolved in water and added to calcium carbonate (CC then dried at 80 °C for 8 h followed by pulverization to a fixed particle size to produce the dry activator consisting of calcium hydroxide (CH, sodium carbonate (SC and pirssonite (P. This increases their commercial availability. The dry activator was blended with granulated blast-furnace slag (GBFS to produce geopolymer cement powder and by addition of water; the geopolymerization process is started. The effect of W/C and SH/CC ratio on the physico-mechanical properties of slag pastes was studied. The results showed that the optimum percent of activator and CC content is 4% SH and 5% CC, by the weight of slag, which give the highest physico-mechanical properties of GBFS. The characterization of the activated slag pastes was carried out using TGA, DTG, IR spectroscopy and SEM techniques.

  12. Production of lightweight Geopolymer concrete using artificial local lightweight aggregate

    Directory of Open Access Journals (Sweden)

    Abbas Waleed

    2018-01-01

    Full Text Available Due to the rapid depletion of natural resources, the use of waste materials and by-products from different industries of building construction has been gaining increased attention. Geopolymer concrete based on Pozzolana is a new material that does not need the presence of Portland cement as a binder. The main focus of this research is to produce lightweight geopolymer concrete (LWGPC using artificial coarse lightweight aggregate which produced from locally available bentonite clays. In this investigation, the binder is low calcium fly ash (FA and the alkali activator is sodium hydroxide and sodium silicate in different molarities. The experimental tests including workability, fresh density, also, the compressive strength, splitting tensile strength, flexural strength, water absorption and ultrasonic pulse velocity at the age of 7, 28 and 56 days were studied. The oven dry density and thermal conductivity at 28 days age are investigated. The results show that it is possible to produce high strength lightweight geopolymer concrete successfully used as insulated structural lightweight concrete. The 28-day compressive strength, tensile strength, flexural strength, dry density, and thermal conductivity of the produced LWGPC are 35.8 MPa, 2.6MPa, 5.5 MPa, 1835kg/m3, and 0.9567 W/ (m. K, respectively.

  13. Evaluation of Geopolymer Concrete for Rocket Test Facility Flame Deflectors

    Science.gov (United States)

    Allgood, Daniel C.; Montes, Carlos; Islam, Rashedul; Allouche, Erez

    2014-01-01

    The current paper presents results from a combined research effort by Louisiana Tech University (LTU) and NASA Stennis Space Center (SSC) to develop a new alumina-silicate based cementitious binder capable of acting as a high performance refractory material with low heat ablation rate and high early mechanical strength. Such a binder would represent a significant contribution to NASA's efforts to develop a new generation of refractory 'hot face' liners for liquid or solid rocket plume environments. This project was developed as a continuation of on-going collaborations between LTU and SSC, where test sections of a formulation of high temperature geopolymer binder were cast in the floor and walls of Test Stand E-1 Cell 3, an active rocket engine test stand flame trench. Additionally, geopolymer concrete panels were tested using the NASA-SSC Diagnostic Test Facility (DTF) thruster, where supersonic plume environments were generated on a 1ft wide x 2ft long x 6 inch deep refractory panel. The DTF operates on LOX/GH2 propellants producing a nominal thrust of 1,200 lbf and the combustion chamber conditions are Pc=625psig, O/F=6.0. Data collected included high speed video of plume/panel area and surface profiles (depth) of the test panels measured on a 1-inch by 1-inch giving localized erosion rates during the test. Louisiana Tech conducted a microstructure analysis of the geopolymer binder after the testing program to identify phase changes in the material.

  14. Production of refractory chamotte particle-reinforced geopolymer composite

    Science.gov (United States)

    Kovářík, T.; Kullová, L.; Rieger, D.

    2016-04-01

    Geopolymer resins are obtained by alkaline activation of aluminosilicate sources where raw calcined clays are one of the suitable potentialities. Besides the fact that chemical composition has an essential effect on final properties of the geopolymer binder, the type of filler strongly affected resulting properties of such granular composite. However, very few comparative studies have been done on detail description of composite systems: binder - granular filler, in relation to aggregate gradation design and rheology properties of the mixture. The aim of this work is to develop and describe granular composite concerning workability of the mixture and kinetics of geopolymerization/polycondensation through flow behaviour. The rheological measurements indicated that initial viscosities of the mixtures and their evolution are different for various proportions of the filler. Moreover, it was demonstrated that increase in complex viscosity responds to the creation of chemical bonds and the formation of structural network. Finally, a correlation of the mechanism of geopolymer formation was carried out by differential scanning calorimetry (DSC).

  15. Strength and Density of Geopolymer Mortar Cured at Ambient Temperature for Use as Repair Material

    Science.gov (United States)

    Warid Wazien, A. Z.; Bakri Abdullah, Mohd Mustafa Al; Abd. Razak, Rafiza; Mohd Remy Rozainy, M. A. Z.; Faheem Mohd Tahir, Muhammad

    2016-06-01

    Geopolymers produced by synthesizing aluminosilicate source materials with an alkaline activator solution promised an excellent properties akin to the existing construction material. This study focused on the effect of various binder to sand ratio on geopolymer mortar properties. Mix design of geopolymer mortar was produced using NaOH concentration of 12 molars, ratio of fly ash/alkaline activator and ratio Na2SiO3/NaOH of 2.0 and 2.5 respectively. Samples subsequently ware cured at ambient temperature. The properties of geopolymer mortar were analysed in term of compressive strength and density at different period which are on the 3rd and 7th day of curing. Experimental results revealed that the addition of sand slightly increase the compressive strength of geopolymer. The optimum compressive strength obtained was up to 31.39 MPa on the 7th day. The density of geopolymer mortar was in the range between 2.0 g/cm3 to 2.23 g/cm3. Based on this findings, the special properties promoted by geopolymer mortar display high potential to be implemented in the field of concrete patch repair.

  16. The relationship between vickers microhardness and compressive strength of functional surface geopolymers

    Science.gov (United States)

    Subaer, Ekaputri, Januari Jaya; Fansuri, Hamzah; Abdullah, Mustafa Al Bakri

    2017-09-01

    An experimental study to investigate the relationship between Vickers microhardness and compressive strength of geopolymers made from metakaolin has been conducted. Samples were prepared by using metakaolin activated with a sodium silicate solution at a different ratio of Si to Al and Na to Al and cured at 70oC for one hour. The resulting geopolymers were stored in an open air for 28 days before conducting any measurement. Bulk density and apparent porosity of the samples were measured by using Archimedes's method. Vickers microhardness measurements were performed on a polished surface of geopolymers with a load ranging from 0.3 - 1.0 kg. The topographic of indented samples were examined by using scanning electron microscopy (SEM). Compressive strength of the resulting geopolymers was measured on the cylindrical samples with a ratio of height to the diameter was 2:1. The results showed that the molar ratios of geopolymers compositions play important roles in the magnitude of bulk density, porosity, Vickers's microhardness as well as the compressive strength. The porosity reduced exponentially the magnitude of the strength of geopolymers. It was found that the relationship between Vickers microhardness and compressive strength was linear. At the request of all authors and with the approval of the proceedings editor, article 020188 titled, "The relationship between vickers microhardness and compressive strength of functional surface geopolymers," is being retracted from the public record due to the fact that it is a duplication of article 020170 published in the same volume.

  17. Compressive strength and microstructural analysis of fly ash/palm oil fuel ash based geopolymer mortar

    International Nuclear Information System (INIS)

    Ranjbar, Navid; Mehrali, Mehdi; Behnia, Arash; Alengaram, U. Johnson; Jumaat, Mohd Zamin

    2014-01-01

    Highlights: • Results show POFA is adaptable as replacement in FA based geopolymer mortar. • The increase in POFA/FA ratio delay of the compressive development of geopolymer. • The density of POFA based geoploymer is lower than FA based geopolymer mortar. - Abstract: This paper presents the effects and adaptability of palm oil fuel ash (POFA) as a replacement material in fly ash (FA) based geopolymer mortar from the aspect of microstructural and compressive strength. The geopolymers developed were synthesized with a combination of sodium hydroxide and sodium silicate as activator and POFA and FA as high silica–alumina resources. The development of compressive strength of POFA/FA based geopolymers was investigated using X-ray florescence (XRF), X-ray diffraction (XRD), Fourier transform infrared (FTIR), and field emission scanning electron microscopy (FESEM). It was observed that the particle shapes and surface area of POFA and FA as well as chemical composition affects the density and compressive strength of the mortars. The increment in the percentages of POFA increased the silica/alumina (SiO 2 /Al 2 O 3 ) ratio and that resulted in reduction of the early compressive strength of the geopolymer and delayed the geopolymerization process

  18. Correlation between hardness and water absorption properties of Saudi kaolin and white clay geopolymer coating

    Science.gov (United States)

    Ramasamy, Shamala; Abdullah, Mohd Mustafa Al Bakri; Huang, Yue; Hussin, Kamarudin; Wang, Jin; Shahedan, Noor Fifinatasha

    2017-09-01

    Geopolymer is an uprising technology that is being studied worldwide. Geopolymer raw materials are basically aluminosilicate source materials. However, this technology is yet to infiltrate into pipelines and coating industries which initiated our research idea. The idea of creating universal geopolymer based coating material is mainly to help oil and gas industry reduce its maintenance cost. Kaolin based geopolymer paste was coated on glass reinforced epoxy (GRE) substrates which are majorly used as pipeline material in the oil and gas industry at Saudi Arabia. Kaolin and white clay was chosen as raw material to study the possibilities of utilizing underused aluminosilicate raw materials for geopolymer coating. To obtain suitable formulation, Na2SiO3/NaOH ratio was varied from 0.40 untill 0.60 while other parameters such as solid/liquid ratio and NaOH molarity were kept constant at values as per previous works. Geopolymer coated GRE substrates were then subjected to water absorption, flexural strength and hardness test to validate our findings. Water absorption is a crucial test as for coating materials which justifies the pratical usability of the coating product. Upon testing, kaolin and white clay based geopolymer coating each shows promising properties at Na2SiO3/NaOH ratio of 0.45 and 0.50 each.

  19. Utilisation of steel furnace slag coarse aggregate in a low calcium fly ash geopolymer concrete

    International Nuclear Information System (INIS)

    Khan, M.S.H.; Castel, Arnaud; Akbarnezhad, A.; Foster, Stephen J.; Smith, Marc

    2016-01-01

    This paper evaluates the performance of steel furnace slag (SFS) coarse aggregate in blended slag and low calcium fly ash geopolymer concrete (GPC). The geopolymer binder is composed of 90% of low calcium fly ash and 10% of ground granulated blast furnace slag (GGBFS). Mechanical and physical properties, shrinkage, and detailed microstructure analysis were carried out. The results showed that geopolymer concrete with SFS aggregate offered higher compressive strength, surface resistivity and pulse velocity than that of GPC with traditional aggregate. The shrinkage results showed no expansion or swelling due to delayed calcium oxide (CaO) hydration after 320 days. No traditional porous interfacial transition zone (ITZ) was detected using scanning electron microscopy, indicating a better bond between SFS aggregate and geopolymer matrix. Energy dispersive spectroscopy results further revealed calcium (Ca) diffusion at the vicinity of ITZ. Raman spectroscopy results showed no new crystalline phase formed due to Ca diffusion. X-ray fluorescence result showed Mg diffusion from SFS aggregate towards geopolymer matrix. The incorporation of Ca and Mg into the geopolymer structure and better bond between SFS aggregate and geopolymer matrix are the most likely reasons for the higher compressive strength observed in GPC with SFS aggregate.

  20. Effect of nanoclay on durability and mechanical properties of flax fabric reinforced geopolymer composites

    Directory of Open Access Journals (Sweden)

    H. Assaedi

    2017-03-01

    Full Text Available The main concern of using natural fibres as reinforcement in geopolymer composites is the durability of the fibres. Geopolymers are alkaline in nature because of the alkaline solution that is required for activating the geopolymer reaction. The alkalinity of the matrix, however, is the key reason of the degradation of natural fibres. The purpose of this study is to determine the effect of nanoclay (NC loading on the mechanical properties and durability of flax fabric (FF reinforced geopolymer composites. The durability of composites after 4 and 32 weeks at ambient temperature is presented. The microstructure of geopolymer matrices was investigated using X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR and scanning electron microscopy (SEM. The results showed that the incorporation of NC has a positive impact on the physical properties, mechanical performance, and durability of FF reinforced geopolymer composites. The presence of NC has a positive impact through accelerating the geopolymerization, reducing the alkalinity of the system and increasing the geopolymer gel.

  1. Performance characterization of geopolymer composites for hot sodium exposed sacrificial layer in fast breeder reactors

    Energy Technology Data Exchange (ETDEWEB)

    Haneefa, K. Mohammed, E-mail: mhkolakkadan@gmail.com [Department of Civil Engineering, IIT Madras, Chennai (India); Santhanam, Manu [Department of Civil Engineering, IIT Madras, Chennai (India); Parida, F. C. [Radiological Safety Division, Indira Gandhi Centre for Atomic Research, Kalpakkam (India)

    2013-12-15

    Highlights: • Performance evaluation of geopolymers subjected to hot liquid sodium is performed. • Apart from mechanical properties, micro-analytical techniques are used for material characterization. • The geopolymer composite showed comparatively lesser damage than conventional cement composites. • Geopolymer technology can emerge as a new choice for sacrificial layer in SCFBRs. - Abstract: A sacrificial layer of concrete is used in sodium cooled fast breeder reactors (SCFBRs) to mitigate thermo-chemical effect of accidentally spilled sodium at and above 550 °C on structural concrete. Performance of this layer is governed by thermo-chemical stability of the ingredients of sacrificial layer concrete. Concrete with limestone aggregate is generally used as a sacrificial layer. Conventional cement based systems exhibit instability in hot liquid sodium environment. Geo-polymer composites are well known to perform excellently at elevated temperatures compared to conventional cement systems. This paper discusses performance of such composites subjected to exposure of hot liquid sodium in air. The investigation includes comprehensive evaluation of various geo-polymer composites before any exposure, after heating to 550 °C in air, and after immersing in hot liquid sodium initially heated to 550 °C in air. Results from the current study indicate that hot liquid sodium produces less damage to geopolymer composites than to the existing conventional cement based system. Hence, the geopolymer technology has potential application in mitigating the degrading effects of sodium fires and can emerge as a new choice for sodium exposed sacrificial layer in SCFBRs.

  2. Tests on coatings made of plastic wraps

    Energy Technology Data Exchange (ETDEWEB)

    Radomil, M; Boubela, L

    1980-01-01

    Testing is a necessity to evaluate the quality of plastic wrappings used as pipe coatings. Many foreign producers indicate the quality of their products by specifying the physical properties of either insulating wraps (their fracture propagation, water-vapor penetrability, electrical resistance, etc.) or the primer with reference to a relevant foreign standard. In principle, therefore none of the insulating materials available are proved with regard to the actual operating properties of the entire insulating system - the corresponding primer and the laminated polyethylene wrap. Because of the need for total system testing, the Fuel Research Institute cooperated with Transitni Plynovod in determining the optimum system to recommend for insulation mechanically applied in the field.

  3. WRAP: a water reactor analysis package

    International Nuclear Information System (INIS)

    Anderson, M.M.

    1977-06-01

    The modular computational system known as the Water Reactor Analysis Package (WRAP) has been developed at the Savannah River Laboratory. WRAP is essentially a reprogrammed version of the RELAP4 computer code with an extensively restructured input format, a dynamic dimensioning capability and additional computational capabilities such as an automatic steady-state option for pressurized water reactors and an automatic restart capability with provision for renodalization. The report describes the capabilities of WRAP at its current stage of development. The addition of new capabilities (e.g., a BWR steady-state capability), the inclusion of improved models (e.g., models in RELAP4/M0D8) and the development of improved numerical techniques to reduce execution time are being planned at this time

  4. Investigating the Nanoporous Structure of Aluminosilicate Geopolymers with Small Angle Scattering and Imaging Techniques

    International Nuclear Information System (INIS)

    Maitland, C.F.; Buckley, C.E.; O'Connor, B.H.; Rowles, M.R.; Hart, R.D.; Gilbert, E.P.; Connolly, J.

    2005-01-01

    Full text: Rowles and O'Connor optimised the compressive strength of a geopolymer produced by sodium silicate-activation of metakaolinite, and found that this material may have a greater compressive strength than ordinary Portland cement. It has been observed that similar metakaolin-based geopolymers have a multiscale structure that consists of partially dissolved metakaolinite embedded in a nanoporous matrix. The characteristics of the nanostructure within this matrix influence the physical properties of the geopolymer. An investigation, using small-angle neutron scattering and imaging techniques, into how the matrix nanostructure varies with chemical composition of the starting material has been undertaken. The results of this investigation will be reported. (authors)

  5. Effect of hydrated lime on compressive strength mortar of fly ash laterite soil geopolymer mortar

    Science.gov (United States)

    Wangsa, F. A.; Tjaronge, M. W.; Djamaluddin, A. R.; Muhiddin, A. B.

    2017-11-01

    This paper explored the suitability of fly ash, hydrated lime, and laterite soil with several activator (sodium hydroxide and sodium tiosulfate) to produce geopolymer mortar. Furthermore, the heat that released by hydrated lime was used instead of oven curing. In order to produce geopolymer mortar without oven curing, three variations of curing condition has been applied. Based on the result, all the curing condition showed that the hardener mortar can be produced and exhibited the increasing of compressive strength of geopolymer mortar from 3 days to 7 days without oven curing.

  6. Technical Assessment: WRAP 1 HVAC Passive Shutdown

    International Nuclear Information System (INIS)

    Ball, D.E.; Nash, C.R.; Stroup, J.L.

    1993-01-01

    As the result of careful interpretation of DOE Order 6430.lA and other DOE Orders, the HVAC system for WRAP 1 has been greatly simplified. The HVAC system is now designed to safely shut down to Passive State if power fails for any reason. The fans cease functioning, allowing the Zone 1 and Zone 2 HVAC Confinement Systems to breathe with respect to atmospheric pressure changes. Simplifying the HVAC system avoided overdesign. Construction costs were reduced by eliminating unnecessary equipment. This report summarizes work that was done to define the criteria, physical concepts, and operational experiences that lead to the passive shutdown design for WRAP 1 confinement HVAC systems

  7. Fabrication of FFTF fuel pin wire wrap

    International Nuclear Information System (INIS)

    Epperson, E.M.

    1980-06-01

    Lateral spacing between FFTF fuel pins is required to provide a passageway for the sodium coolant to flow over each pin to remove heat generated by the fission process. This spacing is provided by wrapping each fuel pin with type 316 stainless steel wire. This wire has a 1.435mm (0.0565 in.) to 1.448mm (0.0570 in.) diameter, contains 17 +- 2% cold work and was fabricated and tested to exacting RDT Standards. About 500 kg (1100 lbs) or 39 Km (24 miles) of fuel pin wrap wire is used in each core loading. Fabrication procedures and quality assurance tests are described

  8. Nanofiber reinforcement of a geopolymer matrix for improved composite materials mechanical performance

    Science.gov (United States)

    Rahman, AKM Samsur

    Geopolymers have the potential to cross the process performance gap between polymer matrix and ceramic matrix composites (CMC), enabling high temperature capable composites that are manufactured at relatively low temperatures. Unfortunately, the inherently low toughness of these geopolymers limits the performance of the resulting fiber reinforced geopolymer matrix composites. Toughness improvements in composites can be addressed through the adjustments in the fiber/matrix interfacial strength and through the improvements in the inherent toughness of the constituent materials. This study investigates the potential to improve the inherent toughness of the geopolymer matrix material through the addition of nanofillers, by considering physical dimensions, mechanical properties, reinforcing capability and interfacial bond strength effects. A process optimization study was first undertaken to develop the ability to produce consistent, neat geopolymer samples, a critical precursor to producing nano-filled geopolymer for toughness evaluation. After that, single edge notched bend beam fracture toughness and un-notched beam flexural strength were evaluated for silicon carbide, alumina and carbon nanofillers reinforced geopolymer samples treated at various temperatures in reactive and inert environments. Toughness results of silicon carbide and carbon nanofillers reinforced geopolymers suggested that with the improved baseline properties, high aspect ratio nanofillers with high interfacial bond strength are the most capable in further improving the toughness of geopolymers. Among the high aspect ratio nanofillers i.e. nanofibers, 2vol% silicon carbide whicker (SCW) showed the highest improvement in fracture toughness and flexural strength of ~164% & ~185%, respectively. After heat treatment at 650 °C, SCW reinforcement was found to be effective, with little reduction in the performance, while the performance of alumina nanofiber (ANF) reinforced geopolymer significantly

  9. Study of the geopolymer restructuration by impulse rheology

    International Nuclear Information System (INIS)

    Rouyer, J.; Frizon, F.; Poulesquen, A.

    2015-01-01

    The aim of the study is to describe the evolution of the microstructure during the setting process of the geo-polymer using an original rheological method named Optimal Fourier Rheology (OFR). The alkali activation of meta-kaolin enables physicochemical transformation from a fresh paste to a hard meso-porous matrix. Classically, oscillatory rheology technique provides viscoelastic moduli spectrum and enables to determine rheological comportment of the material under investigation. However the duration to perform a complete spectrum (more than 2.5 h) makes useless this technique in the case of changing material. The OFR technique decreases the measurement duration under 10 minutes and enables to perform several snapshots of the evolving rheological behaviour. Contrary to monochromatic iterations, here the applied stress takes the form of a chirp function which contains the full usable bandwidth. Interpretations of spectrums provide efficient access to structural evolution along the setting. Results show that the number of oligomers increases into the solution due to the dissolution of the meta-kaolin leading to a constant increase of the viscoelastic parameters until the gradual appearance of the percolating networks. The gelling time was rigorously assessed by using the Winter and Chambon criterion. A fractal percolating network is formed inside the material after a reaction time depending on the formulation parameters; corresponding fractal dimensions were established. After the gel point, the viscoelastic moduli grow rapidly until geo-polymers reach a classic viscoelastic state. Structural unit size were determined using moduli curves crossover and equalled to 2.1 nm in the case of Na geo-polymer; this value fits extremely well with value previously obtained by SAXS. Finally, the elasticity becomes constant in a large frequency range and the viscous parameter strongly decreases which means that the solid porous network is under formation. In conclusion, this

  10. Geopolymer based catalysts-New group of catalytic materials

    Czech Academy of Sciences Publication Activity Database

    Sazama, Petr; Bortnovsky, O.; Dědeček, Jiří; Tvarůžková, Zdenka; Sobalík, Zdeněk

    2011-01-01

    Roč. 164, č. 1 (2011), s. 92-99 ISSN 0920-5861. [Joint International Conference /1./ of the Tokyo Conference on Advanced Catalytic Science and Technology /11./ Asia Pacific Congress on Catalysis /5./. Sapporo, 18.07.2010-23.07.2010] R&D Projects: GA MPO FT-TA4/068; GA AV ČR KAN100400702 Institutional research plan: CEZ:AV0Z40400503 Keywords : geopolymers * redox catalysis * SCR-NOx Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.407, year: 2011

  11. Wrap-Attack Pack: Product Packaging Exercise

    Science.gov (United States)

    Lee, Seung Hwan; Hoffman, K. Douglas

    2016-01-01

    Although many marketing courses discuss traditional concepts pertaining to product strategy, concepts specifically relating to packaging are often glossed over. This exercise, "Wrap-Attack Pack," teaches students about the utilitarian and hedonic design elements of packaging. More specifically, the primary objective is to creatively…

  12. WRAP Module 1 waste characterization plan

    International Nuclear Information System (INIS)

    Mayancsik, B.A.

    1995-01-01

    The purpose of this document is to present the characterization methodology for waste generated, processed, or otherwise the responsibility of the Waste Receiving and Processing (WRAP) Module 1 facility. The scope of this document includes all solid low level waste (LLW), transuranic (TRU), mixed waste (MW), and dangerous waste. This document is not meant to be all-inclusive of the waste processed or generated within WRAP Module 1, but to present a methodology for characterization. As other streams are identified, the method of characterization will be consistent with the other streams identified in this plan. The WRAP Module 1 facility is located in the 200 West Area of the Hanford Site. The facility's function is two-fold. The first is to verify/characterize, treat and repackage contact handled (CH) waste currently in retrievable storage in the LLW Burial Grounds, Hanford Central Waste Complex, and the Transuranic Storage and Assay Facility (TRUSAF). The second is to verify newly generated CH TRU waste and LLW, including MW. The WRAP Module 1 facility provides NDE and NDA of the waste for both drums and boxes. The NDE is used to identify the physical contents of the waste containers to support waste characterization and processing, verification, or certification. The NDA results determine the radioactive content and distribution of the waste

  13. Partial strengthening of R.C square columns using CFRP

    Directory of Open Access Journals (Sweden)

    Ahmed Shaban Abdel-Hay

    2014-12-01

    An experimental program was undertaken testing ten square columns 200 × 200 × 2000 mm. One of them was a control specimen and the other nine specimens were strengthened with CFRP. The main parameters studied in this research were the compressive strength of the upper part, the height of the upper poor concrete part, and the height of CFRP wrapped part of column. The experimental results including mode of failure, ultimate load, concrete strain, and fiber strains were analyzed. The main conclusion of this research was, partial strengthening of square column using CFRP can be permitted and gives good results of the column carrying capacity.

  14. PULSE COLUMN

    Science.gov (United States)

    Grimmett, E.S.

    1964-01-01

    This patent covers a continuous countercurrent liquidsolids contactor column having a number of contactor states each comprising a perforated plate, a layer of balls, and a downcomer tube; a liquid-pulsing piston; and a solids discharger formed of a conical section at the bottom of the column, and a tubular extension on the lowest downcomer terminating in the conical section. Between the conical section and the downcomer extension is formed a small annular opening, through which solids fall coming through the perforated plate of the lowest contactor stage. This annular opening is small enough that the pressure drop thereacross is greater than the pressure drop upward through the lowest contactor stage. (AEC)

  15. Testing a Novel Geopolymer Binder as a Refractory Material for Rocket Plume Environments at SSC Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The project involved the development and testing of a new alumina-silicate based multi-purpose, cost-effective, ‘green’ cementitious binder (geopolymer)...

  16. Coal fly ash-slag-based geopolymers: microstructure and metal leaching.

    Science.gov (United States)

    Izquierdo, Maria; Querol, Xavier; Davidovits, Joseph; Antenucci, Diano; Nugteren, Henk; Fernández-Pereira, Constantino

    2009-07-15

    This study deals with the use of fly ash as a starting material for geopolymeric matrices. The leachable concentrations of geopolymers were compared with those of the starting fly ash to evaluate the retention of potentially harmful elements within the geopolymer matrix. Geopolymer matrices give rise to a leaching scenario characterised by a highly alkaline environment, which inhibits the leaching of heavy metals but may enhance the mobilization of certain oxyanionic species. Thus, fly ash-based geopolymers were found to immobilize a number of trace pollutants such as Be, Bi, Cd, Co, Cr, Cu, Nb, Ni, Pb, Sn, Th, U, Y, Zr and rare earth elements. However, the leachable levels of elements occurring in their oxyanionic form such as As, B, Mo, Se, V and W were increased after geopolymerization. This suggests that an optimal dosage, synthesis and curing conditions are essential in order to obtain a long-term stable final product that ensures an efficient physical encapsulation.

  17. Geopolymer obtained from coal ash; Geopolimeros obtidos a partir de cinzas de carvao mineral

    Energy Technology Data Exchange (ETDEWEB)

    Conte, V.; Bissari, E.S.; Uggioni, E.; Bernardin, A.M., E-mail: amb@unesc.net [Universidade do Extremo Sul Catarinense (UNESC), Criciuma, SC (Brazil). Grupo de Materiais Ceramicos e Vitreos

    2011-07-01

    Geopolymers are three-dimensional alumino silicates that can be rapidly formed at low temperature from naturally occurring aluminosilicates with a structure similar to zeolites. In this work coal ash (Tractebel Energy) was used as source of aluminosilicate according a full factorial design in eight formulations with three factors (hydroxide type and concentration and temperature) and two-levels. The ash was dried and hydroxide was added according type and concentration. The geopolymer was poured into cylindrical molds, cured (14 days) and subjected to compression test. The coal ash from power plants belongs to the Si-Al system and thus can easily form geopolymers. The compression tests showed that it is possible to obtain samples with strength comparable to conventional Portland cement. As a result, temperature and molarity are the main factors affecting the compressive strength of the obtained geopolymer. (author)

  18. Numerical simulation of mechanical properties tests of tungsten mud waste geopolymer

    Science.gov (United States)

    Paszek, Natalia; Krystek, Małgorzata

    2018-03-01

    Geopolymers are believed to become in the future an environmental friendly alternative for the concrete. The low CO2 emission during the production process and the possibility of ecological management of the industrial wastes are mentioned as main advantages of geopolymers. The main drawback, causing problems with application of geopolymers as a building material is the lack of the theoretical material model. Indicated problem is being solved now by the group of scientists from the Silesian University of Technology. The series of laboratory tests are carried out within the European research project REMINE. The paper introduces the numerical analyses of tungsten mud waste geopolymer samples which have been performed in the Atena software on the basis of the laboratory tests. Numerical models of bended and compressed samples of different shapes are presented in the paper. The results obtained in Atena software were compared with results obtained in Abaqus and Mafem3D software.

  19. Coal fly ash-slag-based geopolymers: Microstructure and metal leaching

    Energy Technology Data Exchange (ETDEWEB)

    Izquierdo, Maria, E-mail: mariaizq@ija.csic.es [Institute of Earth Sciences ' Jaume Almera' -CSIC, Lluis Sole Sabaris s/n 08028 Barcelona (Spain); Querol, Xavier [Institute of Earth Sciences ' Jaume Almera' -CSIC, Lluis Sole Sabaris s/n 08028 Barcelona (Spain); Davidovits, Joseph [Cordi-Geopolymere, Espace Creatis, Z.A. Bois de la Chocque 02100 Saint-Quentin (France); Antenucci, Diano [Institut Scientifique de Service Public (ISSeP) 200, rue du Chera, B-4000 Liege (Belgium); Nugteren, Henk [Delft University of Technology, Faculty of Applied Sciences, DelftChemTech, Particle Technology Group, Julianalaan 136, 2628 BL Delft (Netherlands); Fernandez-Pereira, Constantino [University of Seville, School of Industrial Engineering, Department of Chemical and Environmental Engineering, Camino de los Descubrimientos s/n, 41092 Seville (Spain)

    2009-07-15

    This study deals with the use of fly ash as a starting material for geopolymeric matrices. The leachable concentrations of geopolymers were compared with those of the starting fly ash to evaluate the retention of potentially harmful elements within the geopolymer matrix. Geopolymer matrices give rise to a leaching scenario characterised by a highly alkaline environment, which inhibits the leaching of heavy metals but may enhance the mobilization of certain oxyanionic species. Thus, fly ash-based geopolymers were found to immobilise a number of trace pollutants such as Be, Bi, Cd, Co, Cr, Cu, Nb, Ni, Pb, Sn, Th, U, Y, Zr and rare earth elements. However, the leachable levels of elements occurring in their oxyanionic form such as As, B, Mo, Se, V and W were increased after geopolymerization. This suggests that an optimal dosage, synthesis and curing conditions are essential in order to obtain a long-term stable final product that ensures an efficient physical encapsulation.

  20. Coal fly ash-slag-based geopolymers: Microstructure and metal leaching

    International Nuclear Information System (INIS)

    Izquierdo, Maria; Querol, Xavier; Davidovits, Joseph; Antenucci, Diano; Nugteren, Henk; Fernandez-Pereira, Constantino

    2009-01-01

    This study deals with the use of fly ash as a starting material for geopolymeric matrices. The leachable concentrations of geopolymers were compared with those of the starting fly ash to evaluate the retention of potentially harmful elements within the geopolymer matrix. Geopolymer matrices give rise to a leaching scenario characterised by a highly alkaline environment, which inhibits the leaching of heavy metals but may enhance the mobilization of certain oxyanionic species. Thus, fly ash-based geopolymers were found to immobilise a number of trace pollutants such as Be, Bi, Cd, Co, Cr, Cu, Nb, Ni, Pb, Sn, Th, U, Y, Zr and rare earth elements. However, the leachable levels of elements occurring in their oxyanionic form such as As, B, Mo, Se, V and W were increased after geopolymerization. This suggests that an optimal dosage, synthesis and curing conditions are essential in order to obtain a long-term stable final product that ensures an efficient physical encapsulation.

  1. An investigation of waste glass-based geopolymers supplemented with alumina

    Science.gov (United States)

    Christiansen, Mary U.

    An increased consideration of sustainability throughout society has resulted in a surge of research investigating sustainable alternatives to existing construction materials. A new binder system, called a geopolymer, is being investigated to supplement ordinary portland cement (OPC) concrete, which has come under scrutiny because of the CO2 emissions inherent in its production. Geopolymers are produced from the alkali activation of a powdered aluminosilicate source by an alkaline solution, which results in a dense three-dimensional matrix of tetrahedrally linked aluminosilicates. Geopolymers have shown great potential as a building construction material, offering similar mechanical and durability properties to OPC. Additionally, geopolymers have the added value of a considerably smaller carbon footprint than OPC. This research considered the compressive strength, microstructure and composition of geopolymers made from two types of waste glass with varying aluminum contents. Waste glass shows great potential for mainstream use in geopolymers due to its chemical and physical homogeneity as well as its high content of amorphous silica, which could eliminate the need for sodium silicate. However, the lack of aluminum is thought to negatively affect the mechanical performance and alkali stability of the geopolymer system. 39 Mortars were designed using various combinations of glass and metakaolin or fly ash to supplement the aluminum in the system. Mortar made from the high-Al glass (12% Al2O3) reached over 10,000 psi at six months. Mortar made from the low-Al glass (use in geopolymers, when care is given to consider the compositional and physical properties of the glass in mixture design.

  2. Experimental study on workability of alkali activated fly ash and slag-based geopolymer concretes

    NARCIS (Netherlands)

    Arbi, K.A.; Nedeljkovic, M.; Zuo, Y.; Grunewald, S.; Keulen, A.; Ye, G.

    2015-01-01

    This paper presents an investigation on workability and strength of geopolymer concrete made of fly ash (FA), blast furnace slag (BFS) and a multicompound activator of Na2SiO3 and NaOH solutions. The FA/BFS ratios were 100:0, 70:30, 60:40, 50:50, 40:60, 30:70 and 0:100. The workability of geopolymer

  3. Alkali-activated binders/geopolymer and an application to environmental engineering

    OpenAIRE

    Nida Chaimoon; Krit Chaimoon

    2014-01-01

    For environmental reason, new binders that can be used as Portland cement replacement materials are being needed. Recently, alkali-activated binders (AAB) and geopolymer have found increasing interest. As several research reports have showed that the two new binders are likely to have high potential to be developed and become an alternative to OPC. However, confusion in the classification of both binders is still there. This paper reviews knowledge about AAB and geopolymer including historica...

  4. Reduction of metal leaching in brown coal fly ash using geopolymers

    International Nuclear Information System (INIS)

    Bankowski, P.; Zou, L.; Hodges, R.

    2004-01-01

    Current regulations classify fly ash as a prescribed waste and prohibit its disposal in regular landfill. Treatment of the fly ash can reduce the leach rate of metals, and allow it to be disposed in less prescribed landfill. A geopolymer matrix was investigated as a potential stabilisation method for brown coal fly ash. Precipitator fly ash was obtained from electrostatic precipitators and leached fly ash was collected from ash disposal ponds, and leaching tests were conducted on both types of geopolymer stabilised fly ashes. The ratio of fly ash to geopolymer was varied to determine the effects of different compositions on leaching rates. Fourteen metals and heavy metals were targeted during the leaching tests and the results indicate that a geopolymer is effective at reducing the leach rates of many metals from the fly ash, such as calcium, arsenic, selenium, strontium and barium. The major element leachate concentrations obtained from leached fly ash were in general lower than that of precipitator fly ash. Conversely, heavy metal leachate concentrations were lower in precipitator fly ash than leached pond fly ash. The maximum addition of fly ash to this geopolymer was found to be 60 wt% for fly ash obtained from the electrostatic precipitators and 70 wt% for fly ash obtained from ash disposal ponds. The formation of geopolymer in the presence of fly ash was studied using 29Si MAS-NMR and showed that a geopolymer matrix was formed. X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) imaging showed the interaction of the fly ash with the geopolymer, which was related to the leachate data and also the maximum percentage fly ash addition

  5. Performance of fly ash based geopolymer incorporating palm kernel shell for lightweight concrete

    Science.gov (United States)

    Razak, Rafiza Abd; Abdullah, Mohd Mustafa Al Bakri; Yahya, Zarina; Jian, Ang Zhi; Nasri, Armia

    2017-09-01

    A concrete which cement is totally replaced by source material such as fly ash and activated by highly alkaline solutions is known as geopolymer concrete. Fly ash is the most common source material for geopolymer because it is a by-product material, so it can get easily from all around the world. An investigation has been carried out to select the most suitable ingredients of geopolymer concrete so that the geopolymer concrete can achieve the desire compressive strength. The samples were prepared to determine the suitable percentage of palm kernel shell used in geopolymer concrete and cured for 7 days in oven. After that, other samples were prepared by using the suitable percentage of palm kernel shell and cured for 3, 14, 21 and 28 days in oven. The control sample consisting of ordinary Portland cement and palm kernel shell and cured for 28 days were prepared too. The NaOH concentration of 12M, ratio Na2SiO3 to NaOH of 2.5, ratio fly ash to alkaline activator solution of 2.0 and ratio water to geopolymer of 0.35 were fixed throughout the research. The density obtained for the samples were 1.78 kg/m3, water absorption of 20.41% and the compressive strength of 14.20 MPa. The compressive strength of geopolymer concrete is still acceptable as lightweight concrete although the compressive strength is lower than OPC concrete. Therefore, the proposed method by using fly ash mixed with 10% of palm kernel shell can be used to design geopolymer concrete.

  6. Synthesis and characterization of palm oil fuel ash (POFA) and metakaolin based geopolymer for possible application in nanocoating

    Science.gov (United States)

    Khan, Ihsan Ullah; Bhat, A. H.; Masset, Patrick J.; Khan, Farman Ullah; Rehman, Wajid Ur

    2016-11-01

    The main aim of this study was to synthesize and characterize highly amorphous geopolymer from palm oil fuel ash (POFA) and metakaolin, to be used as nanocoating. Geopolymers are man-made aluminosilicate materials that are amorphous analogues of zeolites. The geopolymers were made by condensing a mixture of raw materials metakaolin and palm oil fuel ash (POFA) with alkaline activator at a fixed ratio at room temperature. The kaolin type clay was calcined at 700 °C for 4hrs to transform it into amorphous metakaolin which is more reactive precursor for geopolymer formation. The characteristics of metakaolin and geopolymers (metakaolin and palm oil fuel ash based geopolymers) were analyzed by using x-ray fluorescence (XRF), Fourier transform infra-red spectrometry (FTIR), Thermogravimetric analysis (TG/DTA) and scanning electron microscopy with energy dispersive x-ray analysis (SEM-EDX). FTIR revealed the presence of Al-O and Si-O stretching vibrations of amorphous alumino-silicate structure for metakaolin, palm oil fuel ash and geopolymers. SEM-EDX images showed the presence of reaction product complementary to NASH (N = Na2O, A = Al2O3, S = SiO2, H = H2O) solid. The resulting geopolymers that were synthesized with NaOH/Na2SiO3 solution cured at 60 °C for 3 days. The results demonstrated the suitability of metakaolin and palm oil fuel ash (POFA) for synthesis of geopolymer at room temperatures.

  7. Application-Oriented Chemical Optimization of a Metakaolin Based Geopolymer.

    Science.gov (United States)

    Ferone, Claudio; Colangelo, Francesco; Roviello, Giuseppina; Asprone, Domenico; Menna, Costantino; Balsamo, Alberto; Prota, Andrea; Cioffi, Raffaele; Manfredi, Gaetano

    2013-05-10

    In this study the development of a metakaolin based geopolymeric mortar to be used as bonding matrix for external strengthening of reinforced concrete beams is reported. Four geopolymer formulations have been obtained by varying the composition of the activating solution in terms of SiO₂/Na₂O ratio. The obtained samples have been characterized from a structural, microstructural and mechanical point of view. The differences in structure and microstructure have been correlated to the mechanical properties. A major issue of drying shrinkage has been encountered in the high Si/Al ratio samples. In the light of the characterization results, the optimal geopolymer composition was then applied to fasten steel fibers to reinforced concrete beams. The mechanical behavior of the strengthened reinforced beams was evaluated by four-points bending tests, which were performed also on reinforced concrete beams as they are for comparison. The preliminary results of the bending tests point out an excellent behavior of the geopolymeric mixture tested, with the failure load of the reinforced beams roughly twice that of the control beam.

  8. Application-Oriented Chemical Optimization of a Metakaolin Based Geopolymer

    Directory of Open Access Journals (Sweden)

    Raffaele Cioffi

    2013-05-01

    Full Text Available In this study the development of a metakaolin based geopolymeric mortar to be used as bonding matrix for external strengthening of reinforced concrete beams is reported. Four geopolymer formulations have been obtained by varying the composition of the activating solution in terms of SiO2/Na2O ratio. The obtained samples have been characterized from a structural, microstructural and mechanical point of view. The differences in structure and microstructure have been correlated to the mechanical properties. A major issue of drying shrinkage has been encountered in the high Si/Al ratio samples. In the light of the characterization results, the optimal geopolymer composition was then applied to fasten steel fibers to reinforced concrete beams. The mechanical behavior of the strengthened reinforced beams was evaluated by four-points bending tests, which were performed also on reinforced concrete beams as they are for comparison. The preliminary results of the bending tests point out an excellent behavior of the geopolymeric mixture tested, with the failure load of the reinforced beams roughly twice that of the control beam.

  9. Effect of scopoletin on fascia-wrapped diced cartilage grafts

    African Journals Online (AJOL)

    Surgically wrapped diced cartilages exhibit various degrees of resorption; thus, it has been recommended that fascia be used to wrap diced cartilages. However, few surgeons suggest the use of AlloDerm for wrapping because the harvesting of fascia may cause hematoma and alopecia [17]. Additionally, block grafts have a.

  10. Sulphuric Acid Resistant of Self Compacted Geopolymer Concrete Containing Slag and Ceramic Waste

    Directory of Open Access Journals (Sweden)

    Shafiq I.

    2017-01-01

    Full Text Available Malaysia is a one of the developing countries where the constructions of infrastructure is still ongoing, resulting in a high demand for concrete. In order to gain sustainability factors in the innovations for producing concrete, geopolymer concrete containing granulated blast-furnace slag and ceramics was selected as a cement replacement in concrete for this study. Since Malaysia had many ceramic productions and uses, the increment of the ceramic waste will also be high. Thus, a new idea to reuse this waste in construction materials have been tested by doing research on this waste. Furthermore, a previous research stated that Ordinary Portland Cement concrete has a lower durability compared to the geopolymer concrete. Geopolymer binders have been reported as being acid resistant and thus are a promising and alternative binder for sewer pipe manufacture. Lack of study regarding the durability of the geopolymer self-compacting concrete was also one of the problems. The waste will be undergoing a few processes in the laboratory in order to get it in the best form before undergoing the next process as a binder in geopolymer concrete. This research is very significant in order to apply the concept of sustainability in the construction field. In addition, the impact of this geopolymer binder is that it emits up to nine times less CO2 than Portland Cement.

  11. Influence of inert fillers on shrinkage cracking of meta-kaolin geo-polymers

    International Nuclear Information System (INIS)

    Kuenzel, C.; Boccaccini, A.R.

    2012-01-01

    Geo-polymers contain a network of tetrahedral coordinated aluminate and silicate, and are potential materials to immobilize/encapsulate nuclear wastes. They can exhibit shrinkage cracking when water is removed by drying, and in order to use geo-polymers for waste encapsulation this effect needs to be investigated and controlled. In this study, six different fillers were mixed with meta-kaolin and sodium silicate solution at high pH to form geo-polymers, and the influence of filler addition on mechanical properties has been determined. The fillers used were Fe 2 O 3 , Al 2 O 3 , CaCO 3 , sand, glass and rubber and these do not react during geo-polymerisation reactions. Geo-polymers were prepared containing 30 weight percent of filler. The mechanical properties of the geo-polymers were influenced by the type of filler, with low density fillers increasing mortar viscosity. Geo-polymer samples containing fine filler particles exhibited shrinkage cracking on drying. This was not observed when coarser particles were added and these samples also had significantly improved mechanical properties. (authors)

  12. Development of a geopolymer solidification method for radioactive wastes by compression molding and heat curing

    International Nuclear Information System (INIS)

    Shimoda, Chiaki; Matsuyama, Kanae; Okabe, Hirofumi; Kaneko, Masaaki; Miyamoto, Shinya

    2017-01-01

    Geopolymer solidification is a good method for managing waste because of it is inexpensive as compared with vitrification and has a reduced risk of hydrogen generation. In general, when geopolymers are made, water is added to the geopolymer raw materials, and then the slurry is mixed, poured into a mold, and cured. However, it is difficult to control the reaction because, depending on the types of materials, the viscosity can immediately increase after mixing. Slurries of geopolymers easily attach to the agitating wing of the mixer and easily clog the plumbing during transportation. Moreover, during long-term storage of solidified wastes containing concentrated radionuclides in a sealed container without vents, the hydrogen concentration in the container increases over time. Therefore, a simple method using as little water as possible is needed. In this work, geopolymer solidification by compression molding was studied. As compared with the usual methods, it provides a simple and stable method for preparing waste for long-term storage. From investigations performed before and after solidification by compression molding, it was shown that the crystal structure changed. From this result, it was concluded that the geopolymer reaction proceeded during compression molding. This method (1) reduces the energy needed for drying, (2) has good workability, (3) reduces the overall volume, and (4) reduces hydrogen generation. (author)

  13. Effect of nano-clay on mechanical and thermal properties of geopolymer

    Directory of Open Access Journals (Sweden)

    H. Assaedi

    2016-03-01

    Full Text Available The effect of nano-clay platelets (Cloisite 30B on the mechanical and thermal properties of fly ash geopolymer has been investigated in this paper. The nano-clay platelets are added to reinforce the geopolymer at loadings of 1.0%, 2.0%, and 3.0% by weight. The phase composition and microstructure of geopolymer nano-composites are also investigated using X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR and scanning electron microscope (SEM techniques. Results show that the mechanical properties of geopolymer nano-composites are improved due to addition of nano-clay. It is found that the addition of 2.0 wt% nano-clay decreases the porosity and increases the nano-composite's resistance to water absorption significantly. The optimum 2.0 wt% nano-clay addition exhibited the highest flexural and compressive strengths, flexural modulus and hardness. The microstructural analysis results indicate that the nano-clay behaves not only as a filler to improve the microstructure, but also as an activator to facilitate the geopolymeric reaction. The geopolymer nano-composite also exhibited better thermal stability than its counterpart pure geopolymer.

  14. Resilient modulus characteristics of soil subgrade with geopolymer additive in peat

    Science.gov (United States)

    Zain, Nasuhi; Hadiwardoyo, Sigit Pranowo; Rahayu, Wiwik

    2017-06-01

    Resilient modulus characteristics of peat soil are generally very low with high potential of deformation and low bearing capacity. The efforts to improve the peat subgrade resilient modulus characteristics is required, one among them is by adding the geopolymer additive. Geopolymer was made as an alternative to replace portland cement binder in the concrete mix in order to promote environmentally friendly, low shrinkage value, low creep value, and fire resistant material. The use of geopolymer to improve the mechanical properties of peat as a road construction subgrade, hence it becomes important to identify the effect of geopolymer addition on the resilient modulus characteristics of peat soil. This study investigated the addition of 0% - 20% geopolymer content on peat soil derived from Ogan Komering Ilir, South Sumatera Province. Resilient modulus measurement was performed by using cyclic triaxial test to determine the resilience modulus model as a function of deviator stresses and radial stresses. The test results showed that an increase in radial stresses did not necessarily lead to an increase in modulus resilient, and on the contrary, an increase in deviator stresses led to a decrease in modulus resilient. The addition of geopolymer in peat soil provided an insignificant effect on the increase of resilient modulus value.

  15. Effect of Alkaline Activator to Fly Ash Ratio for Geopolymer Stabilized Soil

    Directory of Open Access Journals (Sweden)

    Abdullah Muhammad Sofian

    2017-01-01

    Full Text Available Geopolymer technology have been developed and explored especially in the construction material field. However, lack of research related to geopolymer stabilized soil. In this research, the utilization of geopolymer has been investigated to stabilize the soil including the factors that affecting the geopolymerization process. Unconfined compressive test (UCT used as indicator to the strength development and hence evaluating the performance of geopolymer stabilized soil. This paper focusing on the effect of fly ash/alkaline activator ratio, Na2SiO3/NaOH ratio and curing time on geopolymer stabilized soil. A various mix design at different fly ash/alkaline activator ratio, Na2SiO3/NaOH ratio were prepared and cured for 7 and 28 days. Molarity and the percentage of geopolymer to soil were fixed at 10 molar and 8 percent respectively. Then, the UCT tests were carried out on 38mm diameter x 76mm height specimens. The highest strength obtained at the fly ash/alkaline activator ratio 2.5 and Na2SiO3/NaOH ratio 2.0 at 28 days curing time.

  16. The Mechanical Properties and Microstructure Characters of Hybrid Composite Geopolymers-Pineapple Fiber Leaves (PFL)

    Science.gov (United States)

    Amalia, N.; Hidayatullah, S.; Nurfadilla; Subaer

    2017-03-01

    The objective of this research is to study the influence of organic fibers on the mechanical properties and microstructure characters of hybrid composite geopolymers-pineapple fibers (PFL). Geopolymers were synthesized by using alkali activated of class C-fly ash added manually with short pineapple fiber leaves (PFL) and then cured at 60°C for 1 hour. The resulting composites were stored in open air for 28 days prior to mechanical and microstructure characterizations. The samples were subjected to compressive and flexural strength measurements, heat resistance as well as acid attack (1M H2SO4 solution). The microstructure of the composites were examined by using Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS). The measurement showed that the addition of pineapple fibers was able to improve the compressive and flexural strength of geopolymers. The resulting hybrid composites were able to resist fire to a maximum temperature of 1500°C. SEM examination showed the presence of good bond between geopolymer matrix and pineapple fibers. It was also found that there were no chemical constituents of geopolymers leached out during acid liquid treatment. It is concluded that hybrid composite geopolymers-pineapple fibers are potential composites for wide range applications.

  17. Effect of aging and alkali activator on the porous structure of a geo-polymer

    International Nuclear Information System (INIS)

    Steins, Prune; Poulesquen, Arnaud; Frizon, Fabien; Lambertin, David; Jestin, Jacques; Rossignol, Sylvie

    2014-01-01

    Nitrogen sorption and small- and wide-angle X-ray and neutron scattering techniques were used to study the porous structure of geo-polymers, inorganic polymers synthesized by reaction of a strongly alkaline solution and an aluminosilicate source (metakaolin). The effects of aging and the use of alkali activators (Na"+, K"+) of different sizes were investigated at room temperature. The influence of aging time on the microstructure of both geo-polymer matrixes was verified in terms of pore volume and specific surface area. The results suggested a refinement of the porosity and therefore a reduction in the pore volume over time. Regardless of the age considered, some characteristics of the porous network such as pore size, shape and distribution depend on the alkali activator used. Whatever the technique considered, the potassium geo-polymer has a greater specific surface area than the sodium geo-polymer. According to the scattering results, the refinement of the porosity can be associated with, first, a densification of the solid network and, secondly, a partial closure of the porosity at the nanometer scale. The kinetics are much slower for the sodium geo-polymer than for the potassium geo-polymer in the six months of observation. (authors)

  18. Solidification/stabilization of ash from medical waste incineration into geopolymers.

    Science.gov (United States)

    Tzanakos, Konstantinos; Mimilidou, Aliki; Anastasiadou, Kalliopi; Stratakis, Antonis; Gidarakos, Evangelos

    2014-10-01

    In the present work, bottom and fly ash, generated from incinerated medical waste, was used as a raw material for the production of geopolymers. The stabilization (S/S) process studied in this paper has been evaluated by means of the leaching and mechanical properties of the S/S solids obtained. Hospital waste ash, sodium hydroxide, sodium silicate solution and metakaolin were mixed. Geopolymers were cured at 50°C for 24h. After a certain aging time of 7 and 28 days, the strength of the geopolymer specimens, the leachability of heavy metals and the mineralogical phase of the produced geopolymers were studied. The effects of the additions of fly ash and calcium compounds were also investigated. The results showed that hospital waste ash can be utilized as source material for the production of geopolymers. The addition of fly ash and calcium compounds considerably improves the strength of the geopolymer specimens (2-8 MPa). Finally, the solidified matrices indicated that geopolymerization process is able to reduce the amount of the heavy metals found in the leachate of the hospital waste ash. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Wetland Resources Action Planning (WRAP) toolkit

    DEFF Research Database (Denmark)

    Bunting, Stuart W.; Smith, Kevin G.; Lund, Søren

    2013-01-01

    The Wetland Resources Action Planning (WRAP) toolkit is a toolkit of research methods and better management practices used in HighARCS (Highland Aquatic Resources Conservation and Sustainable Development), an EU-funded project with field experiences in China, Vietnam and India. It aims to communi......The Wetland Resources Action Planning (WRAP) toolkit is a toolkit of research methods and better management practices used in HighARCS (Highland Aquatic Resources Conservation and Sustainable Development), an EU-funded project with field experiences in China, Vietnam and India. It aims...... to communicate best practices in conserving biodiversity and sustaining ecosystem services to potential users and to promote the wise-use of aquatic resources, improve livelihoods and enhance policy information....

  20. Encapsulation of Mg-Zr alloy in metakaolin-based geo-polymer

    International Nuclear Information System (INIS)

    Rooses, Adrien; Steins, Prune; Dannoux-Papin, Adeline; Lambertin, David; Poulesquen, Arnaud; Frizon, Fabien

    2013-01-01

    Investigations were carried out to propose a suitable material for the encapsulation of Mg-Zr alloy wastes issued from fuel cladding of the first generation nuclear reactors. Stability over time, good mechanical properties and low gas production are the main requirements that embedding matrices must comply with in order to be suitable for long run storage. One of the main issues encapsulating Mg-Zr alloy in mineral binder is the hydrogen production related to Mg-Zr alloys corrosion and water radiolysis process. In this context, metakaolin geo-polymers offer an interesting outlook: corrosion densities of Mg-Zr alloys are significantly lower than in Portland cement. This work firstly presents the hydrogen production of Mg-Zr alloy embedded in geo-polymers prepared from different the activation solution (NaOH or KOH). The effect of addition of fluorine on the magnesium corrosion in geo-polymer has been investigated too. The results point out that sodium geo-polymer is a suitable binder for Mg-Zr alloy encapsulation with respect to magnesium corrosion resistance. Furthermore the presence of fluorine reduces significantly the hydrogen release. Then, the impact of fluorine on the geo-polymer network formation was studied by rheological, calorimetric and 19 F NMR measurements. No direct effect resulting from the addition of fluorine has been shown on the geo-polymer binder. Secondly, the formulation of the encapsulation matrix has been adjusted to fulfil the expected physical and mechanical properties. Observations, dimensional evolutions and compressive strengths demonstrated that addition of sand to the geo-polymer binder is efficient to meet the storage criteria. Consequently, a matrix formulation compatible with Mg-Zr alloy encapsulation has been proposed. Finally, irradiation tests have been carried out to assess the hydrogen radiolytic yield of the matrix under exposure to γ radiation. (authors)

  1. Impact of activator type on the immobilisation of lead in fly ash-based geopolymer

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sujeong [Mineral Resources Research Division, Korea Institute of Geoscience and Mineral Resources, Daejeon 305-350 (Korea, Republic of); University of Science and Technology, Daejeon 305-350 (Korea, Republic of); Riessen, Arie van, E-mail: A.VanRiessen@curtin.edu.au [Curtin University, Perth, Western Australia 6845 (Australia); Chon, Chul-Min [Mineral Resources Research Division, Korea Institute of Geoscience and Mineral Resources, Daejeon 305-350 (Korea, Republic of); Kang, Nam-Hee [University of Science and Technology, Daejeon 305-350 (Korea, Republic of); Jou, Hyeong-Tae [Maritime Security Research Center, Korea Institute of Ocean Science and Technology, Ansan 426-744 (Korea, Republic of); Kim, Youn-Joong [Division of Electron Microscopic Research, Korea Basic Science Institute, Daejeon 305-333 (Korea, Republic of)

    2016-03-15

    Highlights: • The type of alkaline activator critically influences the lead immobilisation capability. • Aluminate-activated geopolymers are more suitable for binding lead in the gel. • When a greater amount of Al contributes to the localized negative charge the tight lead is more tightly bound. • Lead disperses randomly forming no specific chemical compound with silicon. - Abstract: Immobilisation of heavy metals in geopolymers has attracted attention as a potential means of treating toxic wastes. Lead is known to be effectively immobilised in a geopolymer matrix, but detailed explanation for the mechanisms involved and the specific chemical form of lead are not fully understood. To reveal the effect of the activator types on the immobilisation of lead in geopolymers, 0.5 and 1.0 wt% lead in the form of lead nitrate was mixed with fly ash and alkaline activators. Different alkaline activators (either combined sodium hydroxide and sodium silicate or sodium aluminate) were used to achieve the target Si:Al ratios 2.0 and 5.0 in geopolymers. Zeolite was formed in aluminate-activated geopolymers having a Si:Al ratio of 2.0, but the zeolite crystallization was suppressed as lead content increased. No specific crystalline phase of lead was detected by X-ray diffraction, electron diffraction or FT-IR spectrometry. In fact, double Cs corrected TEM analysis revealed that lead was evenly distributed with no evidence of formation of a specific lead compound. A sequential extraction procedure for fractionation of lead showed that lead did not exist as an exchangeable ion in geopolymers, regardless of activator type used. Aluminate activation is shown to be superior in the immobilisation of lead because about 99% of extracted lead existed in the oxidizing and residual fractions.

  2. Novel porous fly-ash containing geopolymer monoliths for lead adsorption from wastewaters

    Energy Technology Data Exchange (ETDEWEB)

    Novais, Rui M., E-mail: ruimnovais@ua.pt; Buruberri, L.H.; Seabra, M.P.; Labrincha, J.A.

    2016-11-15

    Highlights: • Porous fly ash containing-geopolymer monoliths for lead adsorption were developed. • Geopolymers’ porosity and pH of the ion solution controls the adsorption capacity. • Lead adsorption by the geopolymer monoliths up to 6.34 mg/g was observed. • These novel adsorbents can be used in packed beds that are easily collected. • The reuse of biomass fly ash wastes as raw material ensures waste valorization. - Abstract: In this study novel porous biomass fly ash-containing geopolymer monoliths were produced using a simple and flexible procedure. Geopolymers exhibiting distinct total porosities (ranging from 41.0 to 78.4%) and low apparent density (between 1.21 and 0.44 g/cm{sup 3}) were fabricated. Afterwards, the possibility of using these innovative materials as lead adsorbents under distinct conditions was evaluated. Results demonstrate that the geopolymers’ porosity and the pH of the ion solution strongly affect the lead adsorption capacity. Lead adsorption by the geopolymer monoliths ranged between 0.95 and 6.34 mg{sub lead}/g{sub geopolymer}. More porous geopolymers presented better lead removal efficiency, while higher pH in the solution reduced their removal ability, since metal precipitation is enhanced. These novel geopolymeric monoliths can be used in packed beds that are easily collected when exhausted, which is a major advantage in comparison with the use of powdered adsorbents. Furthermore, their production encompasses the reuse of biomass fly-ash, mitigating the environmental impact associated with this waste disposal, while decreasing the adsorbents production costs.

  3. Properties of geopolymer binders prepared from milled pond ash

    Directory of Open Access Journals (Sweden)

    J. Temuujin

    2017-09-01

    Full Text Available Alkali-activated materials were prepared from pond ash from the Darkhan city (Mongolia thermal power station. This ash contains about 60 wt % X-ray amorphous material in addition to quartz, mullite, hematite and magnesioferrite, and presents significant storage problems since it is accumulating in large amounts and is a hazardous waste, containing 90–100 ppm of the heavy metals As, Pb and Cr, and about 800 ppm Sr. Alkali-activated materials synthesized from the as-received pond ash achieved compressive strengths of only 3.25 MPa. Reduction of the particle size by mechanical milling for up to 30 min progressively increases the compressive strength of the resulting alkali-activated geopolymer up to 15.4 MPa. Leaching tests indicate that the combination of milling and alkali treatment does not cause the release of the hazardous heavy metals from the product, making it suitable for construction applications.

  4. Basalt fiber reinforced porous aggregates-geopolymer based cellular material

    Science.gov (United States)

    Luo, Xin; Xu, Jin-Yu; Li, Weimin

    2015-09-01

    Basalt fiber reinforced porous aggregates-geopolymer based cellular material (BFRPGCM) was prepared. The stress-strain curve has been worked out. The ideal energy-absorbing efficiency has been analyzed and the application prospect has been explored. The results show the following: fiber reinforced cellular material has successively sized pore structures; the stress-strain curve has two stages: elastic stage and yielding plateau stage; the greatest value of the ideal energy-absorbing efficiency of BFRPGCM is 89.11%, which suggests BFRPGCM has excellent energy-absorbing property. Thus, it can be seen that BFRPGCM is easy and simple to make, has high plasticity, low density and excellent energy-absorbing features. So, BFRPGCM is a promising energy-absorbing material used especially in civil defense engineering.

  5. Fire Related Temperature Resistance of Fly Ash Based Geopolymer Mortar

    Directory of Open Access Journals (Sweden)

    Jeyalakshmi R.

    2017-01-01

    Full Text Available The study presented in this paper is on the effect of heat treatment on fly ash based geopolymer mortar synthesized from fly ash (Class F –Low lime using alkaline binary activator solution containing sodium hydroxide (18 M and sodium silicate solution (MR 2.0, cured at 80oC for 24 h. 7 days aged specimen heated at elevated temperature (200°C, 400°C, 600°C and 800°C for the sustained period of 2hrs. The TGA/DTA analysis and thermal conductivity measurement as per ASTM C113 were carried out besides the compressive strengths. The thermal stability of the fly ash mortar at elevated temperature was found to be high as reflected in the observed value of f800°C/f30°C being more than 1 and this ratio was raised to about 1.3 with the addition of 2% Zirconium di oxide (ZrO2. No visible cracks were found on the specimens with and without ZrO2 when 800°C was sustained for 4 hrs in smaller specimens of size: 50 mm diameter x 100 mm height and in also bigger size specimens: 22 cm × 11 cm × 7 cm specimens. TGA/DTA analysis of the geopolymer paste showed that the retention of mass was around 90%. The addition of ZrO2 improved thermal resistance. The micro structure of the matrix found to be intact even at elevated temperature that was evident from the FESEM studies.

  6. The Influence of Salt Water on Chloride Penetration in Geopolymer Concrete

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    Halim Like Novia

    2017-01-01

    Full Text Available This paper presents the influence of chloride ion penetration in geopolymer concrete. Fly ash as based material for geopolymer concrete was used in this mixture. Fly ash was mixed with sodium hydroxide (NaOH 8 M and sodium silicate (Na2SiO3 as the alkali solution. The sizes of cylindrical specimens were prepared with a diameter of 100 mm and 200 mm high. Some specimens were immersed in salt water at a concentration of 3.5%, and other control specimens were cured in tap water for 30, 60, 90, and 120 days. The mechanical properties were determined with compressive test which was conducted at 28, 30, 60, 90 and 120 days. Some durability tests were performed for porosity, chloride penetration, and pH measurement. It was found that geopolymer concrete has higher compressive strength than concrete made with Ordinary Portland cement (OPC. However, chloride penetration in geopolymer concrete is higher than OPC. The pH measurement showed that geopolymer concrete has less pH than OPC concrete. The porosity of concrete has been found to influence chloride penetration and pH of concrete.

  7. Ceramic-like open-celled geopolymer foam as a porous substrate for water treatment catalyst

    Science.gov (United States)

    Kovářík, T.; Křenek, T.; Pola, M.; Rieger, D.; Kadlec, J.; Franče, P.

    2017-02-01

    This paper presents results from experimental study on microstructural and mechanical properties of geopolymer-based foam filters. The process for making porous ceramic-like geopolymer body was experimentally established, consists of (a) geopolymer paste synthesis, (b) ceramic filler incorporation, (c) coating of open-celled polyurethane foam with geopolymer mixture, (d) rapid setting procedure, (e) thermal treatment. Geopolymer paste was based on potassium silicate solution n(SiO2)/n(K2O)=1.6 and powder mixture of calcined kaolin and precipitated silica. Various types of ceramic granular filler (alumina, calcined schistous clay and cordierite) were tested in relation to aggregate gradation design and particle size distribution. The small amplitude oscillatory rheometry in strain controlled regime 0.01% with angular frequency 10 rad/s was applied for determination of rheology behavior of prepared mixtures. Thermal treatment conditions were applied in the temperature range 1100 - 1300 °C. The developed porous ceramic-like foam effectively served as a substrate for highly active nanoparticles of selected Fe+2 spinels. Such new-type of nanocomposite was tested as a heterogeneous catalyst for technological process of advanced oxidative degradation of resistive antibiotics occurring in waste waters.

  8. Development of heat resistant geopolymer-based materials from red mud and rice husk ash

    Science.gov (United States)

    Thang, Nguyen Hoc; Nhung, Le Thuy; Quyen, Pham Vo Thi Ha; Phong, Dang Thanh; Khe, Dao Thanh; Van Phuc, Nguyen

    2018-04-01

    Geopolymer is an inorganic polymer composite developed by Joseph Davidovits in 1970s. Such material has potentials to replace Ordinary Portland Cement (OPC)-based materials in the future because of its lower energy consumption, minimal CO2 emissions and lower production cost as it utilizes industrial waste resources. Hence, geopolymerization and the process to produce geopolymers for various applications like building materials can be considered as green industry. Moreover, in this study, red mud and rice husk ash were used as raw materials for geopolymeric production, which are aluminum industrial and agricultural wastes that need to be managed to reduce their negative impact to the environment. The red mud and rice husk ash were mixed with sodium silicate (water glass) solution to form geopolymer paste. The geopolymer paste was filled into 5-cm cube molds according to ASTM C109/C109M 99, and then cured at room temperature for 28 days. These products were then tested for compressive strength and volumetric weight. Results indicated that the material can be considered lightweight with a compressive strength at 28 days that are in the range of 6.8 to 15.5 MPa. Moreover, the geopolymer specimens were also tested for heat resistance at a temperature of 1000oC for 2 hours. Results suggest high heat resistance with an increase of compressive strength from 262% to 417% after exposed at high temperature.

  9. Geopolymers with a high percentage of bottom ash for solidification/immobilization of different toxic metals.

    Science.gov (United States)

    Boca Santa, Rozineide A Antunes; Soares, Cíntia; Riella, Humberto Gracher

    2016-11-15

    Geopolymers are produced using alkali-activated aluminosilicates, either as waste or natural material obtained from various sources. This study synthesized geopolymers from bottom ash and metakaolin (BA/M) in a 2:1wt ratio to test the solidification/immobilization (S/I) properties of heavy metals in geopolymer matrices, since there is very little research using BA in this type of matrices. Therefore, a decision was made to use more than 65% of BA in geopolymer synthesis with and without the addition of heavy metals. The S/I tests with metals used 10, 15 and 30ml of a waste solution after pickling of printed circuit boards containing metals, including Pb, Cr, Cu, Fe, Sn, As and Ni, in different proportions. As alkali activator, the NaOH and KOH were used in the concentrations of 8 and 12M in the composition of Na2SiO3 in 1:2vol ratios. To test S/I efficiency, tests were conducted to obtain the leached and solubilized extract. The analysis was carried out through X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Scanning Electron Microscope (SEM), Energy-Dispersive X-Ray Spectroscopy (EDS) and compressive strength tests. The geopolymer showed a high degree of S/I of the metals; in some samples, the results reached nearly 100%. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Studying the effect of thermal and acid exposure on alkali activated slag Geopolymer

    Directory of Open Access Journals (Sweden)

    Khater H.M.

    2014-04-01

    Full Text Available This article reports a study about thermal stability as well as acid resistance of geopolymer materials prepared from Ground Granulated Blast Furnace Slag (GGBFS, Air Cooled Slag (ACS, Silica fume (SF and cement kiln dust (CKD using 6% (weight of equal mix from alkaline sodium hydroxide and sodium silicate activators. Study of addition of ACS, SF and CKD as partial replacement of GGBFS is investigated so as to improve the mechanical and microstructural properties of geopolymer mixes. Compressive strength and SEM were utilized in these studies. Materials were prepared using water/binder of 0.30 at 38°C and 100% RH. Results showed that geopolymer materials prepared using alkali activated slag exhibit large changes in compressive strength with increasing the firing temperature from 300 to 1000°C and exhibit an enhancement in thermal stability as compared to concrete specimens. Materials prepared by replacing GGBFS by 15% ACS resist thermal deterioration up to 1000°C. It was suggested to be suitable for refractory insulation applications as well as for production of nuclear concrete reactors. On the other hand, geopolymer mixes exhibit low stability upon subjecting to different concentration from the mix of nitric and hydrochloric acid in equal ratio (1:1. Current studies of geopolymer microstructure were focused on the morphology as well as the relationship between compositions and mechanical properties.

  11. Tensile behaviour of geopolymer-based materials under medium and high strain rates

    Science.gov (United States)

    Menna, Costantino; Asprone, Domenico; Forni, Daniele; Roviello, Giuseppina; Ricciotti, Laura; Ferone, Claudio; Bozza, Anna; Prota, Andrea; Cadoni, Ezio

    2015-09-01

    Geopolymers are a promising class of inorganic materials typically obtained from an alluminosilicate source and an alkaline solution, and characterized by an amorphous 3-D framework structure. These materials are particularly attractive for the construction industry due to mechanical and environmental advantages they exhibit compared to conventional systems. Indeed, geopolymer-based concretes represent a challenge for the large scale uses of such a binder material and many research studies currently focus on this topic. However, the behaviour of geopolymers under high dynamic loads is rarely investigated, even though it is of a fundamental concern for the integrity/vulnerability assessment under extreme dynamic events. The present study aims to investigate the effect of high dynamic loading conditions on the tensile behaviour of different geopolymer formulations. The dynamic tests were performed under different strain rates by using a Hydro-pneumatic machine and a modified Hopkinson bar at the DynaMat laboratory of the University of Applied Sciences of Southern Switzerland. The results are processed in terms of stress-strain relationships and strength dynamic increase factor at different strain-rate levels. The dynamic increase factor was also compared with CEB recommendations. The experimental outcomes can be used to assess the constitutive laws of geopolymers under dynamic load conditions and implemented into analytical models.

  12. Synergetic use of lignite fly ash and metallurgical converter slag in geopolymer concrete

    Directory of Open Access Journals (Sweden)

    Gábor Mucsi

    2014-08-01

    Full Text Available The application and utilization of the industrial wastes and by-products in the construction industry is a key issue from an environmental and economic point of view. The increased use of lignite has substantially increased the available quantities of lignite fired power plant fly ash, which can be mainly classified as class C fly ash. The utilization of such raw material however has some difficulties. In the present paper lignite fired power station fly ash and metallurgical converter slag were used for the production of geopolymer concrete. The fly ash was used as a geopolymer based binder material, and a converter slag as aggregate, thus created a geopolymer concrete which contains mainly industrial wastes. As preliminary test experimental series were carried out using andesite as aggregate. The optimal aggregate/binder ratio was determined. The effect of the amount of alkaline activator solution in the binder, the aggregate type on the geopolymer concretes’ compressive strength and density was investigated. Furthermore, the physical properties - freeze-thaw resistance and particle size distribution - of the applied aggregates were measured as well. As a result of the experiments it was found that physical properties of the andesite and converter slag aggregate was close. Therefore andesite can be replaced by converter slag in the concrete mixture. Additionally, geopolymer concrete with nearly 20 MPa compressive strength was produced from class C fly ash and converter slag.

  13. TiO2-Based Photocatalytic Geopolymers for Nitric Oxide Degradation

    Science.gov (United States)

    Strini, Alberto; Roviello, Giuseppina; Ricciotti, Laura; Ferone, Claudio; Messina, Francesco; Schiavi, Luca; Corsaro, Davide; Cioffi, Raffaele

    2016-01-01

    This study presents an experimental overview for the development of photocatalytic materials based on geopolymer binders as catalyst support matrices. Particularly, geopolymer matrices obtained from different solid precursors (fly ash and metakaolin), composite systems (siloxane-hybrid, foamed hybrid), and curing temperatures (room temperature and 60 °C) were investigated for the same photocatalyst content (i.e., 3% TiO2 by weight of paste). The geopolymer matrices were previously designed for different applications, ranging from insulating (foam) to structural materials. The photocatalytic activity was evaluated as NO degradation in air, and the results were compared with an ordinary Portland cement reference. The studied matrices demonstrated highly variable photocatalytic performance depending on both matrix constituents and the curing temperature, with promising activity revealed by the geopolymers based on fly ash and metakaolin. Furthermore, microstructural features and titania dispersion in the matrices were assessed by scanning electron microscopy (SEM) and energy dispersive X-ray (EDS) analyses. Particularly, EDS analyses of sample sections indicated segregation effects of titania in the surface layer, with consequent enhancement or depletion of the catalyst concentration in the active sample region, suggesting non-negligible transport phenomena during the curing process. The described results demonstrated that geopolymer binders can be interesting catalyst support matrices for the development of photocatalytic materials and indicated a large potential for the exploitation of their peculiar features. PMID:28773634

  14. TiO2-Based Photocatalytic Geopolymers for Nitric Oxide Degradation

    Directory of Open Access Journals (Sweden)

    Alberto Strini

    2016-06-01

    Full Text Available This study presents an experimental overview for the development of photocatalytic materials based on geopolymer binders as catalyst support matrices. Particularly, geopolymer matrices obtained from different solid precursors (fly ash and metakaolin, composite systems (siloxane-hybrid, foamed hybrid, and curing temperatures (room temperature and 60 °C were investigated for the same photocatalyst content (i.e., 3% TiO2 by weight of paste. The geopolymer matrices were previously designed for different applications, ranging from insulating (foam to structural materials. The photocatalytic activity was evaluated as NO degradation in air, and the results were compared with an ordinary Portland cement reference. The studied matrices demonstrated highly variable photocatalytic performance depending on both matrix constituents and the curing temperature, with promising activity revealed by the geopolymers based on fly ash and metakaolin. Furthermore, microstructural features and titania dispersion in the matrices were assessed by scanning electron microscopy (SEM and energy dispersive X-ray (EDS analyses. Particularly, EDS analyses of sample sections indicated segregation effects of titania in the surface layer, with consequent enhancement or depletion of the catalyst concentration in the active sample region, suggesting non-negligible transport phenomena during the curing process. The described results demonstrated that geopolymer binders can be interesting catalyst support matrices for the development of photocatalytic materials and indicated a large potential for the exploitation of their peculiar features.

  15. Synthesis of geopolymer composites from a mixture of volcanic scoria and metakaolin

    Directory of Open Access Journals (Sweden)

    J.N.Y. Djobo

    2014-12-01

    Full Text Available The aim of this work is to valorize volcanic scoria by using them as starting material for geopolymers production. Nevertheless, volcanic scoria possesses low reactivity. Various amounts of metakaolin (5%, 10%, 15%, 20% and 25% were added into two volcanic scoria (ZD and ZG in order to improve their reactivity. Two alkaline solutions were used to activate the aluminosilicate materials. The starting materials were characterized by particle size distribution, specific surface area, chemical and mineralogical composition. The geopolymers were characterized by the setting time, XRD, FTIR, SEM and compressive strength. The results indicated that volcanic scoria have low specific surface area (2.3 m2/g for ZD, 15.7 m2/g for ZG, high average particle size (d50 = 13.08 μm and 10.68 μm for ZD and for ZG respectively and low glass phase contents. Metakaolin have a smaller average particle size (d50 = 9.95 μm and high specific surface (20.5 m2/g. The compressive strength of geopolymers increased in the ranges of 23–68 MPa and 39–64 MPa for geopolymers from ZD–MK and ZG–MK respectively. This study shows that despite the low reactivity of volcanic scoria it can still be used to synthesize geopolymers with good physical and mechanical properties.

  16. The Properties of Nano Silver (Ag-Geopolymer as Antibacterial Composite for Functional Surface Materials

    Directory of Open Access Journals (Sweden)

    Armayani. M

    2017-01-01

    Full Text Available The purpose of this research was to produce and characterize nano silver (Ag-geopolymer composite for functional surface materials. Geopolymer matrix was synthesized through alkali activation of metakaolin and nano silver was added into geopolymers paste with a mass of 0, 0.5 g, 1 g, 1.5 g and 2 g keeping the mass of metakaolin constant. The mixture was cured at 70°C/1 hour and stored for 7 days before conducting any measurements. The structure of the resulting composite was examined by using Rigaku Mini Flex II x-ray diffraction (XRD. Scanning Electron Microscopy (SEM coupled with Energy Dispersive Spectroscopy (EDS was used to examine the morphology of the composite surface as well as the capability of the composite to isolate the growth of bacteria. The thermal properties of composites in terms of their working temperature and enthalpy were examined by using Perkin Elmer Differential Scanning Calorimetry (DSC. The heat resistance of composite was observed through calcination at 750°C for 18 hours. The results indicate that the resulting composites were able resist up 750°C. SEM examinations showed that nano Ag-geopolymer composites were effectively restraining the growth of bacteria. It is suggested that nano Ag-geopolymer composites are suitable for functional surface applications such as floor and wall, kitchen ware utensils, hospital instruments, art and decoration materials.

  17. The sentence wrap-up dogma.

    Science.gov (United States)

    Stowe, Laurie A; Kaan, Edith; Sabourin, Laura; Taylor, Ryan C

    2018-03-30

    Current sentence processing research has focused on early effects of the on-line incremental processes that are performed at each word or constituent during processing. However, less attention has been devoted to what happens at the end of the clause or sentence. More specifically, over the last decade and a half, a lot of effort has been put into avoiding measuring event-related brain potentials (ERPs) at the final word of a sentence, because of the possible effects of sentence wrap-up. This article reviews the evidence on how and when sentence wrap-up impacts behavioral and ERP results. Even though the end of the sentence is associated with a positive-going ERP wave, thus far this effect has not been associated with any factors hypothesized to affect wrap-up. In addition, ERP responses to violations have not been affected by this positivity. "Sentence-final" negativities reported in the literature are not unique to sentence final positions, nor do they obscure or distort ERP effects associated with linguistic manipulations. Finally, the empirical evidence used to argue that sentence-final ERPs are different from those recorded at sentence-medial positions is weak at most. Measuring ERPs at sentence-final positions is therefore certainly not to be avoided at all costs, especially not in cases where the structure of the language under investigation requires it. More importantly, researchers should follow rigorous method in their experimental design, avoid decision tasks which may induce ERP confounds, and ensure all other possible explanations for results are considered. Although this article is directed at a particular dogma from a particular literature, this review shows that it is important to reassess what is regarded as "general knowledge" from time to time. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Biological data integration: wrapping data and tools.

    Science.gov (United States)

    Lacroix, Zoé

    2002-06-01

    Nowadays scientific data is inevitably digital and stored in a wide variety of formats in heterogeneous systems. Scientists need to access an integrated view of remote or local heterogeneous data sources with advanced data accessing, analyzing, and visualization tools. Building a digital library for scientific data requires accessing and manipulating data extracted from flat files or databases, documents retrieved from the Web as well as data generated by software. We present an approach to wrapping web data sources, databases, flat files, or data generated by tools through a database view mechanism. Generally, a wrapper has two tasks: it first sends a query to the source to retrieve data and, second builds the expected output with respect to the virtual structure. Our wrappers are composed of a retrieval component based on an intermediate object view mechanism called search views mapping the source capabilities to attributes, and an eXtensible Markup Language (XML) engine, respectively, to perform these two tasks. The originality of the approach consists of: 1) a generic view mechanism to access seamlessly data sources with limited capabilities and 2) the ability to wrap data sources as well as the useful specific tools they may provide. Our approach has been developed and demonstrated as part of the multidatabase system supporting queries via uniform object protocol model (OPM) interfaces.

  19. Preparation and Characterization of New Geopolymer-Epoxy Resin Hybrid Mortars

    Directory of Open Access Journals (Sweden)

    Raffaele Cioffi

    2013-07-01

    Full Text Available The preparation and characterization of metakaolin-based geopolymer mortars containing an organic epoxy resin are presented here for the first time. The specimens have been prepared by means of an innovative in situ co-reticulation process, in mild conditions, of commercial epoxy based organic resins and geopolymeric slurry. In this way, geopolymer based hybrid mortars characterized by a different content of normalized sand (up to 66% in weight and by a homogeneous dispersion of the organic resin have been obtained. Once hardened, these new materials show improved compressive strength and toughness in respect to both the neat geopolymer and the hybrid pastes since the organic polymer provides a more cohesive microstructure, with a reduced amount of microcracks. The microstructural characterization allows to point out the presence of an Interfacial Transition Zone similar to that observed in cement based mortars and concretes. A correlation between microstructural features and mechanical properties has been studied too.

  20. Metakaolin-Based Geopolymer with Added TiO2 Particles: Physicomechanical Characteristics

    Directory of Open Access Journals (Sweden)

    Luis A. Guzmán-Aponte

    2017-12-01

    Full Text Available The effect of the TiO2 addition on the physicomechanical properties of a geopolymer system based on metakaolin (MK and hydroxide and potassium silicate as activators is presented in this article. Three different liquid-solid systems (0.35, 0.40, and 0.45 and two titanium additions were investigated (5% and 10% of the cement content. The flowability, setting time, and mechanical strength of the geopolymer mixtures and their microstructural characteristics were evaluated using techniques such as X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, and scanning electron microscopy (SEM. It was concluded that a percentage of up to 10% TiO2 does not affect the mechanical properties of the geopolymer, although it does reduce the fluidity and setting times of the mixture.

  1. Properties and Behavior of Geopolymer Concrete Subjected to Explosive Air Blast Loading: A Review

    Directory of Open Access Journals (Sweden)

    Mohd Mortar Nurul Aida

    2017-01-01

    Full Text Available The severe damage to civilian buildings, public area, jet aircraft impact and defense target under explosive blast loading can cause a huge property loss. Most of researcher discusses the topics on design the concrete material model to sustain againts the explosive detonation. The implementation of modern reinforcement steels and fibres in ordinary Portland cement (OPC concrete matrix can reduce the extreme loading effects. However, most researchers have proved that geopolymer concrete (GPC has better mechanical properties towards high performance concrete, compared to OPC. GPC has the high early compressive strength and high ability to resist the thermal energy from explosive detonation. In addition, OPC production is less environmental friendly than geopolymer cement. Geopolymer used can lead to environmental protection besides being improved in mechanical properties. Thus, this paper highlighted on an experimental, numerical and the analytical studies cause of the explosive detonation impact to concrete structures.

  2. Innovative Fly Ash Geopolymer-Epoxy Composites: Preparation, Microstructure and Mechanical Properties

    Directory of Open Access Journals (Sweden)

    Giuseppina Roviello

    2016-06-01

    Full Text Available The preparation and characterization of composite materials based on geopolymers obtained from fly ash and epoxy resins are reported for the first time. These materials have been prepared through a synthetic method based on the concurrent reticulation of the organic and inorganic components that allows the formation of hydrogen bonding between the phases, ensuring a very high compatibility between them. These new composites show significantly improved mechanical properties if compared to neat geopolymers with the same composition and comparable performances in respect to analogous geopolymer-based composites obtained starting from more expensive raw material such as metakaolin. The positive combination of an easy synthetic approach with the use of industrial by-products has allowed producing novel low cost aluminosilicate binders that, thanks to their thixotropicity and good adhesion against materials commonly used in building constructions, could be used within the field of sustainable building.

  3. A Comprehensive Study of the Polypropylene Fiber Reinforced Fly Ash Based Geopolymer

    DEFF Research Database (Denmark)

    Ranjbar, Navid; Mehrali, Mehdi; Behnia, Arash

    2016-01-01

    and long term impacts of different volume percentages of polypropylene fiber (PPF) reinforcement on fly ash based geopolymer composites. Different characteristics of the composite were compared at fresh state by flow measurement and hardened state by variation of shrinkage over time to assess the response...... of composites under flexural and compressive load conditions. The fiber-matrix interface, fiber surface and toughening mechanisms were assessed using field emission scan electron microscopy (FESEM) and atomic force microscopy (AFM). The results show that incorporation of PPF up to 3 wt % into the geopolymer......As a cementitious material, geopolymers show a high quasi-brittle behavior and a relatively low fracture energy. To overcome such a weakness, incorporation of fibers to a brittle matrix is a well-known technique to enhance the flexural properties. This study comprehensively evaluates the short...

  4. Geopolymers with a high percentage of bottom ash for solidification/immobilization of different toxic metals

    Energy Technology Data Exchange (ETDEWEB)

    Boca Santa, Rozineide A. Antunes, E-mail: roosebs@gmail.com; Soares, Cíntia; Riella, Humberto Gracher

    2016-11-15

    Highlights: • Geopolymers from bottom ash and metakaolin (BA/M). • Solidification/immobilization (S/I) waste of heavy metals. • Activators: Sodium hydroxide (NaOH), potassium hydroxide (KOH) and sodium silicate (Na{sub 2}SiO{sub 3}). - Abstract: Geopolymers are produced using alkali-activated aluminosilicates, either as waste or natural material obtained from various sources. This study synthesized geopolymers from bottom ash and metakaolin (BA/M) in a 2:1 wt ratio to test the solidification/immobilization (S/I) properties of heavy metals in geopolymer matrices, since there is very little research using BA in this type of matrices. Therefore, a decision was made to use more than 65% of BA in geopolymer synthesis with and without the addition of heavy metals. The S/I tests with metals used 10, 15 and 30 ml of a waste solution after pickling of printed circuit boards containing metals, including Pb, Cr, Cu, Fe, Sn, As and Ni, in different proportions. As alkali activator, the NaOH and KOH were used in the concentrations of 8 and 12 M in the composition of Na{sub 2}SiO{sub 3} in 1:2 vol ratios. To test S/I efficiency, tests were conducted to obtain the leached and solubilized extract. The analysis was carried out through X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Scanning Electron Microscope (SEM), Energy-Dispersive X-Ray Spectroscopy (EDS) and compressive strength tests. The geopolymer showed a high degree of S/I of the metals; in some samples, the results reached nearly 100%.

  5. Geopolymers with a high percentage of bottom ash for solidification/immobilization of different toxic metals

    International Nuclear Information System (INIS)

    Boca Santa, Rozineide A. Antunes; Soares, Cíntia; Riella, Humberto Gracher

    2016-01-01

    Highlights: • Geopolymers from bottom ash and metakaolin (BA/M). • Solidification/immobilization (S/I) waste of heavy metals. • Activators: Sodium hydroxide (NaOH), potassium hydroxide (KOH) and sodium silicate (Na 2 SiO 3 ). - Abstract: Geopolymers are produced using alkali-activated aluminosilicates, either as waste or natural material obtained from various sources. This study synthesized geopolymers from bottom ash and metakaolin (BA/M) in a 2:1 wt ratio to test the solidification/immobilization (S/I) properties of heavy metals in geopolymer matrices, since there is very little research using BA in this type of matrices. Therefore, a decision was made to use more than 65% of BA in geopolymer synthesis with and without the addition of heavy metals. The S/I tests with metals used 10, 15 and 30 ml of a waste solution after pickling of printed circuit boards containing metals, including Pb, Cr, Cu, Fe, Sn, As and Ni, in different proportions. As alkali activator, the NaOH and KOH were used in the concentrations of 8 and 12 M in the composition of Na 2 SiO 3 in 1:2 vol ratios. To test S/I efficiency, tests were conducted to obtain the leached and solubilized extract. The analysis was carried out through X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Scanning Electron Microscope (SEM), Energy-Dispersive X-Ray Spectroscopy (EDS) and compressive strength tests. The geopolymer showed a high degree of S/I of the metals; in some samples, the results reached nearly 100%.

  6. Geopolymers based on the valorization of Municipal Solid Waste Incineration residues

    Science.gov (United States)

    Giro-Paloma, J.; Maldonado-Alameda, A.; Formosa, J.; Barbieri, L.; Chimenos, J. M.; Lancellotti, I.

    2017-10-01

    The proper management of Municipal Solid Waste (MSW) has become one of the main environmental commitments for developed countries due to the uncontrolled growth of waste caused by the consumption patterns of modern societies. Nowadays, municipal solid waste incineration (MSWI) is one of the most feasible solutions and it is estimated to increase in Europe where the accessibility of landfill is restricted. Bottom ash (BA) is the most significant by-product from MSWI as it accounts for 85 - 95 % of the solid product resulting from combustion, which is classified as a non-hazardous residue that can be revalorized as a secondary aggregate in road sub-base, bulk lightweight filler in construction. In this way, revalorization of weathered BA (WBA) for the production of geopolymers may be a good alternative to common reuse as secondary aggregate material; however, the chemical process to obtain these materials involves several challenges that could disturb the stability of the material, mainly from the environmental point of view. Accordingly, it is necessary that geopolymers are able to stabilize heavy metals contained in the WBA in order to be classified as non-hazardous materials. In this regard, the SiO2/Al2O3 ratio plays an important role for the encapsulation of heavy metals and other toxic elements. The aim of this research is to formulate geopolymers starting from the 0 - 2 mm particle size fraction of WBA, as a unique raw material used as aluminumsilicate precursor. Likewise, leaching tests of the geopolymers formulated were performed to assess their environmental impact. The findings show that it is possible to formulate geopolymers using 100 % WBA as precursor, although more investigations are needed to sustain that geopolymer obtained can be considered as non-hazardous materials.

  7. Preparation of geopolymer-based inorganic membrane for removing Ni{sup 2+} from wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Yuanyuan; Yuan, Yuan; Wang, Kaituo; He, Yan; Cui, Xuemin, E-mail: cui-xm@tsinghua.edu.cn

    2015-12-15

    Highlights: • A type free-sintering geopolymer membrane for waste water treatment was fabricated. • The geopolymer inorganic membrane held good strength and appropriate water flux. • The mechanism of removing Ni{sup 2+} combined actions of the adsorption and rejection. • The geopolymer membrane is a promising way to remove heavy metal ions in industry. - Abstract: A type of novel free-sintering and self-supporting inorganic membrane for wastewater treatment was fabricated in this study. This inorganic membrane was synthesised using metakaolin and sodium silicate solutions moulded according to a designed molar ratio (SiO{sub 2}/Al{sub 2}O{sub 3} = 2.96, Na{sub 2}O/Al{sub 2}O{sub 3} = 0.8 and H{sub 2}O/Na{sub 2}O = 19) which formed a homogenous structure and had a relative concentration pore size distribution, via scanning electron microscopy (SEM) and Brunauer–Emmett–Teller (BET) analyses. In this work, the Ni{sup 2+} removal effect of geopolymer inorganic membrane was studied under different pH value, initial concentration of Ni{sup 2+} solutions and initial operation temperature. Results showed that geopolymer inorganic membrane efficiently removes Ni{sup 2+} from wastewater because of the combined actions of the adsorption and rejection of this membrane on Ni{sup 2+} during membrane separation. Therefore, geopolymer inorganic membrane may have positive potential applications in removing Ni{sup 2+} or other heavy metal ions from aqueous industrial wastewater.

  8. A Novel MK-based Geopolymer Composite Activated with Rice Husk Ash and KOH: Performance at High Temperature

    International Nuclear Information System (INIS)

    Villaquirán-Caicedo, M.A.; Mejía de Gutiérrez, R.; Gallego, N.C.

    2017-01-01

    Geopolymers were produced using an environmentally friendly alkali activator (based on Rice Husk Ash and potassium hydroxide). Aluminosilicates particles, carbon and ceramic fibres were used as reinforcement materials. The effects of reinforcement materials on the flexural strength, linear-shrinkage, thermophysical properties and microstructure of the geopolymers at room and high temperature (1200 °C) were studied. The results indicated that the toughness of the composites is increased 110.4% for geopolymer reinforced by ceramic fibres (G-AF) at room temperature. The presence of particles improved the flexural behaviour 265% for geopolymer reinforced by carbon fibres and particles after exposure to 1200 .C. Linear-shrinkage for geopolymer reinforced by ceramic fibres and particles and the geopolymer G-AF compared with reference sample (without fibres and particles) is improved by 27.88% and 7.88% respectively at 900 °C. The geopolymer materials developed in this work are porous materials with low thermal conductivity and good mechanical properties with potential thermal insulation applications for building applications. [es

  9. A Novel MK-based Geopolymer Composite Activated with Rice Husk Ash and KOH: Performance at High Temperature

    Directory of Open Access Journals (Sweden)

    M. A. Villaquirán-Caicedo

    2017-02-01

    Full Text Available Geopolymers were produced using an environmentally friendly alkali activator (based on Rice Husk Ash and potassium hydroxide. Aluminosilicates particles, carbon and ceramic fibres were used as reinforcement materials. The effects of reinforcement materials on the flexural strength, linear-shrinkage, thermophysical properties and microstructure of the geopolymers at room and high temperature (1200 ÅãC were studied. The results indicated that the toughness of the composites is increased 110.4% for geopolymer reinforced by ceramic fibres (G-AF at room temperature. The presence of particles improved the flexural behaviour 265% for geopolymer reinforced by carbon fibres and particles after exposure to 1200 .C. Linear-shrinkage for geopolymer reinforced by ceramic fibres and particles and the geopolymer G-AF compared with reference sample (without fibres and particles is improved by 27.88% and 7.88% respectively at 900 ÅãC. The geopolymer materials developed in this work are porous materials with low thermal conductivity and good mechanical properties with potential thermal insulation applications for building applications.

  10. Geopolymers in Construction / Zastosowanie Geopolimerów W Budownictwie

    Science.gov (United States)

    Błaszczyński, Tomasz Z.; Król, Maciej R.

    2015-03-01

    Within the framework of quests of supplementary and "healthier" binders to the production of concrete followed the development of geopolymers in construction. However the practical application of these materials is still very limited. The production of each ton of cement introduces one ton of CO2 into the atmosphere. According to various estimations, the synthesis of geopolymers absorbs 2-3 times less energy than the Portland cement and causes a generation of 4-8 times less of CO2. Geopolymeric concretes possess a high compressive strength, very small shrinkage and small creep, and they possess a high resistance to acid and sulphate corrosion. These concretes are also resistant to carbonate corrosion and possess a very high fire resistance and also a high resistance to UV radiation. W ramach poszukiwania zastępczych i "zdrowszych" spoiw do produkcji betonu nastąpił rozwój geopolimerów w budownictwie. Jednakże praktyczne zastosowanie tych materiałów jest jeszcze nadal bardzo ograniczone. Produkcja każdej tony cementu wprowadza do atmosfery tonę CO2. Według różnych szacunków, synteza geopolimerów pochłania 2-3 razy mniej energii, niż cementu portlandzkiego oraz powoduje wydzielenie 4-8 razy mniejszej ilości CO2. Do tego betony geopolimerowe posiadają wysoką wytrzymałość na ściskanie, bardzo mały skurcz i małe pełzanie oraz dają wysoką odporność na korozję kwasową i siarczanową. Betony te są także odporne na korozję węglanową i posiadają bardzo wysoką odporność ogniową, a także wysoką odporność na promieniowanie UV.

  11. Aqueous dissolution of sodium aluminosilicate geopolymers derived from metakaolin

    Energy Technology Data Exchange (ETDEWEB)

    Aly, Z., E-mail: zaynab.aly@ansto.gov.au [Institute of Materials Engineering, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); Vance, E.R. [Institute of Materials Engineering, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); Perera, D.S. [School of Materials Science, University of NSW, Kensington, NSW 2052 (Australia)

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer In dilute solutions, Na, Al and Si releases were not sensitive to pH in range 4-10. Black-Right-Pointing-Pointer On heating from 18 to 90 Degree-Sign C in DIW, Na dissolution rate increased by a factor of {approx}4. Black-Right-Pointing-Pointer Elemental extractions in DIW at 18 Degree-Sign C increased linearly with time over 1-7 days. Black-Right-Pointing-Pointer Na release kinetics in DIW followed a pseudo-second-order kinetic model. Black-Right-Pointing-Pointer Contact with KCl, KHCO{sub 3} and phthalate buffers (pH6 and 10) resulted in Na{sup +} {r_reversible} K{sup +} exchange. - Abstract: In dilute aqueous solutions, the elemental releases of Na, Al and Si from a metakaolin-based sodium aluminosilicate geopolymer were not very sensitive to pH in the range of 4-10 but increased outside this range, particularly on the acidic side. To minimise pH drifts, experiments were carried out using small amounts of graded powders in relatively large volumes of water. In deionised water, the Na dissolution rate in 7 days was dominant and increased by at least a factor of {approx}4 on heating from 18 to 90 Degree-Sign C, with greater increases in the extractions of Al and Si. At 18 Degree-Sign C the elemental extractions in deionised water increased approximately linearly with time over the 1-7 days period. Further exposure led to a slower extraction into solution for Na and Si, with a decrease in extraction of Al. It was deduced that framework dissolution was important in significantly acidic or alkaline solutions, but that contributions from water transfer from pores to elemental extractions were present, even at low temperatures in neutral solutions. It was also deduced from the Na release data that the Na leaching kinetics of geopolymer in deionised water (dilute solutions) followed the pseudo-second-order kinetic model and the pseudo-second-order rate constant evaluated. Contact with KCl, KHCO{sub 3}, and pH {approx}6 and 10

  12. Waste Receiving and Processing Facility (WRAP) Drawing List

    International Nuclear Information System (INIS)

    WEIDERT, J.R.

    1999-01-01

    This supporting document delineates the process of identification, categorization, and/or classification of the WRAP facility drawings used to support facility operations and maintenance. This document provides a listing of those essential or safety related drawings which have been identified to date. All other WRAP facility drawings have been classified as general

  13. 9 CFR 327.9 - Burlap wrapping for foreign meat.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Burlap wrapping for foreign meat. 327... AGRICULTURE AGENCY ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION IMPORTED PRODUCTS § 327.9 Burlap wrapping for foreign meat. Burlap shall not be...

  14. Structural Behaviors of Reinforced Concrete Piers Rehabilitated with FRP Wraps

    Directory of Open Access Journals (Sweden)

    Junsuk Kang

    2017-01-01

    Full Text Available The use of fiber-reinforced polymer (FRP wraps to retrofit and strengthen existing structures such as reinforced concrete piers is becoming popular due to the higher tensile strength, durability, and flexibility gained and the method’s ease of handling and low installation and maintenance costs. As yet, however, few guidelines have been developed for determining the optimum thicknesses of the FRP wraps applied to external surfaces of concrete or masonry structures. In this study, nonlinear pushover finite element analyses were utilized to analyze the complex structural behaviors of FRP-wrapped reinforced rectangular piers. Design parameters such as pier section sizes, pier heights, pier cap lengths, compressive strengths of concrete, and the thicknesses of the FRP wraps used were thoroughly tested under incremental lateral and vertical loads. The results provide useful guidelines for analyzing and designing appropriate FRP wraps for existing concrete piers.

  15. Sulfate resistance of fly ash-based geopolymer mortar

    Science.gov (United States)

    Saloma, Iqbal, Maulid Muhammad; Aqil, Ibnu

    2017-09-01

    This paper presents sulfuric acid attack of fly ash-based geopolymer mortar. Precursor used in this study was fly ash, and activator used was NaOH and Na2SiO3. The ratio of activator/precursor, ratio of Na2SiO3/NaOH, and ratio of fine aggregate/precursor is 0.42, 2.00, and 2.00, respectively. The molar concentration of NaOH which was used were 8, 10, 12, 14, and 16 M. This study used cube specimen with 5 cm x 5 cm x 5 cm. The results showed that the higher the molar concentration of NaOH, the lower the weight loss. Maximum percentage of weight loss is 3.54% occured for the specimen with molar concentration of NaOH 8 M. The compressive strength for all specimens decreased due to the longer duration of immersion in sulfuric acid solution. However, this percentage of decreasing for compressive strength will be as lower as increasing the molar concentration of NaOH used. The maximum percentage of decreasing is 35.49% for specimen with NaOH 8 M with 90 days of immersion.

  16. Characteristics of alkali activated material (geopolymer) in sulfuric acid solution

    Science.gov (United States)

    Simatupang, Partogi H.

    2017-09-01

    Alkali Activated Material (AAM) or Geopolymer is a solid material which made by mixing rich silica alumina material with alkaline activator. AAM is a well known candidate to replace cement based material. Many researches have claimed that AAM has better durability compared to cement based material in agressive environment. However, there was rare paper presented the direct comparison of material characteristics between Class F fly ash based AAM and Class C fly ash based AAM in such aggresive environment. Because of that, this paper present material characteristics of Class F fly ash based AAM and Class C fly ash based AAM if the materials were immersed in 10% sulfuric acid solution for 65 days. Material characteristics evaluated were (1) weight loss, (2) mineral of the material which evaluated by XRD (X-Ray Diffraction), (3) morphology and oxide compounds of material which evaluated by SEM/EDXA (Scanning Electron Microscopic/Energy Dispersive X-Ray Analyzer) and (4) compound bond which evaluated by FTIR (Fourier Transform Infra Red) Spectroscopy Testing. Alkali Activated Material used were Class F fly ash based AAM Mortar and Class C fly ash based AAM Mortar. The result is a quite difference of material characteristics between Class F fly ash based AAM and Class C fly ash based AAM.

  17. Effect of delayed wrapping and wrapping source on nitrogen balance and blood urea nitrogen in gestating sheep offered alfalfa silage

    Science.gov (United States)

    Exposing ensiled forage to oxygen can result in DM deterioration and reduce silage intake by animals. This study was conducted to investigate the effects of 2 different wrapping sources and time intervals between baling and wrapping on N balance and blood urea N in gestating sheep offered alfalfa si...

  18. Micostructural and mechanical properties of geopolymers synthesised from three coal fly ashes from South Africa

    CSIR Research Space (South Africa)

    Dludlu, MK

    2017-01-01

    Full Text Available In this study, coal fly ashes (CFAs) from three different boiler sites in South Africa, Eskom (E coal fly ash), George Mukhari Academic Hospital (GMH coal fly ash), and KarboChem (KBC coal fly ash), were used to produce geopolymers. The coal fly...

  19. Reuse of Coconut Shell, Rice Husk, and Coal Ash Blends in Geopolymer Synthesis

    Science.gov (United States)

    Walmiki Samadhi, Tjokorde; Wulandari, Winny; Prasetyo, Muhammad Iqbal; Rizki Fernando, Muhammad

    2017-10-01

    Mixtures of biomass and coal ashes are likely to be produced in increasing volume as biomass-based energy production is gaining importance in Indonesia. This work highlights the reuse of coconut shell ash (CSA), rice husk ash (RHA), and coal fly ash (FA) for geopolymer synthesis by an activator solution containing concentrated KOH and Na2SiO3. Ash blend compositions are varied according to a simplex-centroid mixture experimental design. Activator to ash mass ratios are varied from 0.8 to 2.0, the higher value being applied for ash compositions with higher Si/Al ratio. The impact of ash blend composition on early strength is adequately modeled by an incomplete quadratic mixture model. Overall, the ashes can produce geopolymer mortars with an early strength exceeding the Indonesian SNI 15-2049-2004 standard minimum value of 2.0 MPa. Good workability of the geopolymer is indicated by their initial setting times which are longer than the minimum value of 45 mins. Geopolymers composed predominantly of RHA composition exhibit poor strength and excessive setting time. FTIR spectroscopy confirms the geopolymerization of the ashes by the shift of the Si-O-Si/Al asymmetric stretching vibrational mode. Overall, these results point to the feasibility of geopolymerization as a reuse pathway for biomass combustion waste.

  20. Inclusion of geopolymers derivate from fly ash and pumice in reinforced concrete

    Science.gov (United States)

    Montaño, A. M.; González, C. P.; Castro, D.; Gualdron, G.; Atencio, R.

    2017-12-01

    This paper presents results of a research project related to the development of alkali-activated geopolymers, synthesized from alumina-silicate minerals (fly ash and pumice) which are added to concrete. Alkali sources used in geopolymer synthesis were sodium hydroxide and sodium silicate solution. New materials were structurally characterized by Infra-Red spectroscopy (IR) and X-Ray Diffraction (XRD). Concretes obtained after geopolymers addition as Portland cement substitutes at 10%, 20% and 30%, were mechanically analysed by compression resistance at 7, 14, 28 and 90 drying days. Results were referred to standard (concrete of Portland cement) allows to know cementitious characteristics of geopolymers are lower than those for standard, but it keeps growing at longer drying time than Portland cement. By Electrochemical Impedance Spectroscopy (EIS) it is found that this new material shows high electrical resistance and have been proved as a protection agent against corrosion in reinforced concrete exhibiting anticorrosive properties higher than those showed by the conventional concrete mixture.

  1. FT-IR and 29 Si-NMR for evaluating aluminium silicate precursors for geopolymers

    NARCIS (Netherlands)

    Valcke, S.L.A.; Pipilikaki, P.; Fischer, H.R.; Verkuijlen, M.H.W.; Eck, E.R.H.

    2014-01-01

    Geopolymers are systems of inorganic binders that can be used for sustainable, cementless concrete and are formed by alkali activation of an aluminium–silicate precursor (often secondary resources like fly ash or slag). The type of aluminium– silicate precursor and its potential variations within

  2. FREEZE-THAW AND FIRE RESISTANCE OF GEOPOLYMER MORTAR BASED ON NATURAL AND WASTE POZZOLANS

    Directory of Open Access Journals (Sweden)

    F.Nurhayat Degirmenci

    2017-12-01

    Full Text Available The purpose of this research was to investigate the resistance of pozzolan-based geopolymer mortars subjected to high temperatures and freeze-thaw cycles. Low calcium fly ash and granulated blast furnace slag as waste pozzolans and natural zeolite as a natural pozzolan were used as base materials for producing geopolymer mortar. The other purpose the research was to study the effect of alkaline activator ratio (Na₂SiO₃/NaOH on the performance of pozzolan-based geopolymer mortar specimens subjected to extreme temperatures. The influence of high temperatures on the properties of mortars was investigated at 300°C, 600°C, and 900°C. Fire and freeze-thaw and resistance of mortars were investigated in terms of visual appearance, weight loss and residual compressive strength. The minimal values of the residual compressive strength were obtained at 900°C for all mixtures. The residual compressive strength of all specimens was lower than the values obtained for specimens not subjected to any freeze-thaw resistance test, except those containing GGBS. The Na₂SiO₃/NaOH ratios of the alkaline activator solution used to prepare the geopolymer mortars have an effect on the weight losses and residual compressive strengths of the specimens subjected to high temperatures and freeze-thaw cycles. As the Na2SiO3/NaOH ratios increased, the weight and strength losses decreased.

  3. Effect of the rate of calcination of kaolin on the properties of metakaolin-based geopolymers

    Directory of Open Access Journals (Sweden)

    B.B. Kenne Diffo

    2015-03-01

    Full Text Available Kaolin samples of the same mass were treated at 700 °C for the same duration of 30 min by varying the rate of calcination (1, 2.5, 5, 10, 15 and 20 °C/min in order to obtain metakaolins which were used to produce geopolymers. Depending on the nature of each type of material, kaolin, metakaolins and geopolymers were characterized using thermal analysis, chemical analysis, XRD, FTIR, particle size distribution, specific surface area, bulk density, setting time and compressive strength. FTIR and XRD analyses showed that metakaolins except at 1 °C/min contained residual kaolinite whose quantity increased with the rate of calcination of kaolin and which influenced the characteristics of geopolymers. Thus as the rate of calcination of kaolin increased, the setting time increased (226 min (rate of 1 °C/min–773 min (rate of 20 °C/min while the compressive strength reduced (49.4 MPa (rate of 1 °C/min–20.8 MPa (rate of 20 °C/min. From the obtained results the production of geopolymers having high compressive strength along with low setting time requires that the calcination of kaolin be carried out at a low rate.

  4. Characterization of Zeolite in Zeolite-Geopolymer Hybrid Bulk Materials Derived from Kaolinitic Clays

    Directory of Open Access Journals (Sweden)

    Hayami Takeda

    2013-05-01

    Full Text Available Zeolite-geopolymer hybrid materials have been formed when kaolin was used as a starting material. Their characteristics are of interest because they can have a wide pore size distribution with micro- and meso-pores due to the zeolite and geopolymer, respectively. In this study, Zeolite-geopolymer hybrid bulk materials were fabricated using four kinds of kaolinitic clays (a halloysite and three kinds of kaolinite. The kaolinitic clays were first calcined at 700 °C for 3 h to transform into the amorphous aluminosilicate phases. Alkali-activation treatment of the metakaolin yielded bulk materials with different amounts and types of zeolite and different compressive strength. This study investigated the effects of the initial kaolinitic clays on the amount and types of zeolite in the resultant geopolymers as well as the strength of the bulk materials. The kaolinitic clays and their metakaolin were characterized by XRD analysis, chemical composition, crystallite size, 29Si and 27Al MAS NMR analysis, and specific surface area measurements. The correlation between the amount of zeolite formed and the compressive strength of the resultant hybrid bulk materials, previously reported by other researchers was not positively observed. In the studied systems, the effects of Si/Al and crystalline size were observed. When the atomic ratio of Si/Al in the starting kaolinitic clays increased, the compressive strength of the hybrid bulk materials increased. The crystallite size of the zeolite in the hybrid bulk materials increased with decreasing compressive strength of the hybrid bulk materials.

  5. Influence of water on stability of geopolymers investigated by NMR solid state spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Kobera, Libor; Brus, Jiří; Urbanová, Martina; Slavík, R.

    2008-01-01

    Roč. 33, - (2008), s. 86 ISSN 1896-2203. [Mid-European Clay Conference MECC 08 /4./. 22.09.2008-27.09.2008, Zakopane] R&D Projects: GA AV ČR IAA400500602 Institutional research plan: CEZ:AV0Z40500505 Keywords : stability * NMR * solid state spectroscopy * geopolymer Subject RIV: CD - Macromolecular Chemistry

  6. Development of Coconut Trunk Fiber Geopolymer Hybrid Composite for Structural Engineering Materials

    Science.gov (United States)

    Amalia, F.; Akifah, N.; Nurfadilla; Subaer

    2017-03-01

    A research on the influence of coconut fiber trunk on mechanical properties based on fly ash has been conducted. The aims of this study was to examine the mechanical properties of geopolymer composites by varrying the concentration of coconut trunk fiber. Geopolymer synthesized by alkali activated (NaOH+H2O+Na2O.3SiO2) and cured at the temperature 700C for one hour. Specimens were synthesized into 5 different mass of fiber 0 g, 0.25 g, 0.50 g, 0.75 g, and 1.00 g keeping fly ash constant. The highest compressive strength was 89.44 MPa for specimen added with 0.50 g of fiber. The highest flexural strength was 7.64 MPa for the same sample. The interfacial transition zone (ITZ) between the matrix of geopolymers and coconut fiber was conducted by using Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS). The chemical composition of the specimen was examined by using X-Ray Diffraction (XRD). The thermal properties of coconut fiber trunk was analyzed using Differential Scanning Calorimetry (DSC). It was found that coconut fiber was able to improve the mechanical and microstructure properties of geopolymers composites.

  7. Influence of Kaolin in Fly Ash Based Geopolymer Concrete: Destructive and Non-Destructive Testing

    Science.gov (United States)

    Yahya, Z.; Abdullah, M. M. A. B.; Ramli, N. Mohd; Burduhos-Nergis, D. D.; Razak, R. Abd

    2018-06-01

    Development of geopolymer concrete is mainly to reduce the production of ordinary Portland cement (OPC) that adverse the natural effect. Fly ash is a by-product collected from electrical generating power plant which resulted from burning pulverized coal. Since fly ash is waste materials, it can be recycled for future advantages particularly as pozzolanic materials in construction industry. This study focused on the feasibility of fly ash based geopolymer concrete to which kaolin has been added. The main constituents of geopolymer production for this study were class F fly ash, sodium silicate and sodium hydroxide (NaOH) solution. The concentration of NaOH solution was fixed at 12 Molar, ratio of fly ash/alkaline activator and sodium silicate/NaOH fixed at 1.5 and 2.5, respectively. Kaolin was added in range 5% to 15% from the mass of fly ash and all the samples were cured at room temperature. Destructive and non-destructive test were performed on geopolymer concrete to evaluate the best mix proportions that yield the highest strength as well as the quality of the concrete. Compressive strength, flexural strength, rebound hammer and ultrasonic pulse velocity (UPV) result have been obtained. It shown that 5% replacement of kaolin contributed to maximum compressive strength and flexural strength of 40.4 MPa and 12.35 MPa at 28 days. These result was supported by non-destructive test for the same mix proportion.

  8. The identification of geopolymer affinity in specific cases of clay materials

    Czech Academy of Sciences Publication Activity Database

    Perná, Ivana; Hanzlíček, Tomáš; Šupová, Monika

    2014-01-01

    Roč. 102, December (2014), s. 213-219 ISSN 0169-1317 R&D Projects: GA MPO FR-TI2/390 Institutional support: RVO:67985891 Keywords : geopolymer * raw material * infrared spectroscopy * shale Subject RIV: JI - Composite Materials Impact factor: 2.467, year: 2014

  9. The Manufacture of the Grinding Wheels Based on the Ca–K Geopolymer Matrix

    Czech Academy of Sciences Publication Activity Database

    Perná, Ivana; Hanzlíček, Tomáš; Boura, P.; Lučaník, A.

    2016-01-01

    Roč. 31, č. 5 (2016), s. 667-672 ISSN 1042-6914 Institutional support: RVO:67985891 Keywords : geopolymer * grinding * wheel * low-temperature * industrial * manufacturing * technology Subject RIV: DM - Solid Waste and Recycling Impact factor: 2.274, year: 2016

  10. Microstructural characterization of the geopolymer obtained from iron-rich metakaolin

    International Nuclear Information System (INIS)

    Vassalo, Erica Antunes de S.; Aguilar, Maria Teresa P.; Gumieri, Adriana Guerra

    2014-01-01

    Geopolymer is a material derived from precursors rich in SiO_2 and Al_2O_3, activated in an alkaline solution by means of a polymerization process. In this process, units of tetrahedral aluminosilicate structures are organized in repetitions that share oxygen. One of the precursors most commonly used to obtain geopolymer is metakaolin. Recent studies have reported iron enhancement in a partial replacement of the aluminium present in metakaolin. This paper presents the microstructural characterization and analysis of a geopolymer obtained by means of the activation of iron-rich metakaolin with sodium hydroxide at 12, 15 and 18 mol, both at room temperature and in an oven at 85±3°C. The geopolymers obtained were classified and analysed using X-ray fluorescence testing (EDX-720), a scanning electron microscope (SEM) and a Fourier transform infrared spectroscopy (FTIR). The results enabled an assessment of their physical-chemical and microstructural characteristics, as well as their reactive potential. (author)

  11. Rice husk (RH) as additive in fly ash based geopolymer mortar

    Science.gov (United States)

    Yahya, Zarina; Razak, Rafiza Abd; Abdullah, Mohd Mustafa Al Bakri; Rahim, Mohd Azrin Adzhar; Nasri, Armia

    2017-09-01

    In recent year, the Ordinary Portland Cement (OPC) concrete is vastly used as main binder in construction industry which lead to depletion of natural resources in order to manufacture large amount of OPC. Nevertheless, with the introduction of geopolymer as an alternative binder which is more environmental friendly due to less emission of carbon dioxide (CO2) and utilized waste materials can overcome the problems. Rice husk (RH) is an agricultural residue which can be found easily in large quantity due to production of paddy in Malaysia and it's usually disposed in landfill. This paper investigated the effect of rice husk (RH) content on the strength development of fly ash based geopolymer mortar. The fly ash is replaced with RH by 0%, 5%, 10%, 15% and 20% where the sodium silicate and sodium hydroxide was used as alkaline activator. A total of 45 cubes were casted and their compressive strength, density and water absorption were evaluated at 1, 3, and 7 days. The result showed compressive strength decreased when the percentage of RH increased. At 5% replacement of RH, the maximum strength of 17.1MPa was recorded at day 7. The geopolymer has lowest rate of water absorption (1.69%) at 20% replacement of RH. The density of the sample can be classified as lightweight geopolymer concrete.

  12. Mix design and mechanical performance of geopolymer binder for sustainable construction and building material

    Science.gov (United States)

    Saeli, Manfredi; Novais, Rui M.; Seabra, Maria Paula; Labrincha, João A.

    2017-11-01

    Sustainability in construction is a major concern worldwide, due to the huge volume of materials and energy consumed by this sector. Associated supplementing industries (e.g. Portland cement production) constitute a significant source of CO2 emissions and global warming. Valorisation and reuse of industrial wastes and by-products make geopolymers a solid and sustainable via to be followed as a valid alternative to Portland cement. In this work the mix design of a green fly ash-based geopolymer is evaluated as an environmentally friendly construction material. In the pursuit of sustainability, wastes from a regional kraft pulp industry are exploited for the material processing. Furthermore, a simple, reproducible, and low-cost manufacture is used. The mix design is hence optimised in order to improve the desirable mechanical performance of the material intended for structural applications in construction. Tests indicate that geopolymers may efficiently substitute the ordinary Portland cement as a mortar/concrete binder. Furthermore, valorisation and reuse of wastes in geopolymers is a suboptimal way of gaining financial surplus for the involved industrial players, while contributes for the implementation of a desirable circular economy.

  13. Effect of silica fume on the characterization of the geopolymer materials

    Science.gov (United States)

    Khater, Hisham M.

    2013-12-01

    The influence of silica fume (SF) addition on properties of geopolymer materials produced from alkaline activation of alumino-silicates metakaolin and waste concrete produced from demolition works has been studied through the measurement of compressive strength, Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy (SEM) analysis. Alumino-silicate materials are coarse aggregate included waste concrete and fired kaolin (metakaolin) at 800°C for 3 h, both passing a sieve of 90 μm. Mix specimens containing silica fume were prepared at water/binder ratios in a range of 0.30 under water curing. The used activators are an equal mix of sodium hydroxide and silicate in the ratio of 3:3 wt.%. The control geopolymer mix is composed of metakaolin and waste concrete in an equal mix (50:50, wt.%). Waste concrete was partially replaced by silica fume by 1 to 10 wt.%. The results indicated that compressive strengths of geopolymer mixes incorporating SF increased up to 7% substitution and then decreased up to 10% but still higher than that of the control mix. Results indicated that compressive strengths of geopolymer mixes incorporating SF increases up to 7% substitution and then decreases up to 10% but still higher than the control mix, where 7% SF-digested calcium hydroxide (CH) crystals, decreased the orientation of CH crystals, reduced the crystal size of CH gathered at the interface, and improved the interface more effectively.

  14. The effect of steam curing on chloride penetration in geopolymer concrete

    Directory of Open Access Journals (Sweden)

    Jaya Ekaputri Januarti

    2017-01-01

    Full Text Available In this paper, we present the result of our study on the effect of steam curing to chloride ion penetration in geopolymer concrete. Class F fly ash was activated using sodium hydroxide (NaOH and sodium silicate (Na2SiO3. The concrete specimens were then steam-cured at 40°C, 60°C, 80°C and room temperature at 24 hours. The treatment was followed by wet curing for 28 days, and then followed by immersion of all specimens in salt water for the durations of 30, 60, and 90 days. Cylindrical specimens were then prepared for compressive strength, chloride ion penetration, pH, and porosity tests. A 16 mm-steel bar was fixed at the center of the specimen concrete blocks (specimen size: 10cm × 10cm × 15cm. Corrosion probability was determined by conducting Half Cell Potential test. Our result showed that increasing the curing temperature to 80°C induced chloride ion penetration into the concrete’s effective pores, despite improvements in compressive strength. We also found that chloride ingress on the geopolymer concrete increases commensurately with the increase of the curing temperature. The corrosion potential measurement of geopolymer concrete was higher than OPC concrete even if corrosion was not observed in reinforcing. Based on our result, we suggest that the corrosion categorization for geopolymer concretes needs to be adjusted.

  15. MICROSTRUCTURE, MINERALOGY AND PHYSICAL PROPERTIES OF GROUND FLY ASH BASED GEOPOLYMERS

    Directory of Open Access Journals (Sweden)

    Ferenc Madai

    2015-03-01

    Full Text Available This paper is focused on the utilization of deposited fly ash as a main component of geopolymer. After determination of particle size distribution, moisture content, real and bulk density and specific surface area of the raw fly ash, mechanical activation was performed by laboratory scale ball mill. This step is introduced for improving the reactivity of raw material. Then test specimens were produced by geopoliomerisation using a caustic spent liquor (NaOH. Compressive strength was determined on cilindrical specimens. Finally, samples of the ground fly ash based geopolymer specimens were analyzed by X-ray diffraction, optical and scanning electron microscopy. Results prove that geopolymer production with proper strength from the investigated F-type deposited fly ash is possible. The uniaxial compressive strength of obtained composites strongly depends on the fineness of the ground fly ash. XRD results show that comparing the crystalline components for different geopolymer samples, zeolite-A appears and its amount increases gradually from 0T sample till 30T and then decreases for 60T sample. The same trend holds for sodalite type structure phases, however its amount is much lower than for zeolite-A. SEM+EDS investigation revealed that Na-content is elevated in the interstitial fine-grained matrix, especially for the 30T sample when highest strength was observed. Si and Al are abundant mainly in anhedral and spherical grains and in rarely occurring grains resembling some crystal shape.

  16. THE INFLUENCE OF PHOSPHORUS SLAG ADDITION ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF METAKAOLIN-BASED GEOPOLYMER PASTES

    Directory of Open Access Journals (Sweden)

    M. A. SOLEIMANI

    2013-03-01

    Full Text Available In this study, metakaolin plus different weight percent of phosphorus slag (10-100 wt. % were used in preparation of geopolymer. The compressive strength, phase analysis and microstructure changes were compared with a metakaolin based geopolymer control sample. Results showed that the substitution of slag up to 40 wt. % instead of metakaolin increase the 28 days compressive strength (14.5 % compared with control sample. This enhancement of strength is related to coexistence of geopolymeric gel and C‒S‒H gel or C‒A‒S‒H phase by XRD and FTIR study. In slag containing geopolymer samples some microcracks were observed at microstructure that established by volume change during formation of new phase or mismatching of unreacted particle with geopolymeric gel. These microcrack can dominate at high content of slag (above 40 wt. % substitution and decrease the strength of samples. These results show that it is possible to produce geopolymer cement from waste phosphorus slages.

  17. Optimum Mix for Pervious Geopolymer Concrete (GEOCRETE Based on Water Permeability and Compressive Strength

    Directory of Open Access Journals (Sweden)

    Abdulsalam Arafa Salaheddin

    2017-01-01

    Full Text Available The production of ordinary Portland cement (OPC consumes considerable natural resources and energy, and it also affects the emission of a significant quantity of CO2 in the atmosphere. This pervious geopolymer concrete study aims to explore an alternative binder without OPC. Pervious geopolymer concretes were prepared from fly ash (FA, sodium silicate (NaSiO3, sodium hydroxide (NaOH solution, and coarse aggregate (CA. The effects of pervious geopolymer concrete parameters that affect water permeability and compressive strength are evaluated. The FA to CA ratios of 1:6, 1:7,1:8, and 1:9 by weight, CA sizes of 5–10, 10–14, and 14–20 mm, constant NaSiO3/NaOH ratio of 2.5, alkaline liquid to fly ash (AL/FA ratios of 0.4, 0.5, and 0.6, and NaOH concentrations of 8, 10, and 12 M were the pervious geopolymer concrete mix proportions. The curing temperature of 80 °C for 24 h was used. The results showed that a pervious geopolymer concrete with CA of 10 mm achieved water permeability of 2.3 cm/s and compressive strength of 20 MPa with AL/FA ratio of 0.5, NaOH concentration of 10 M, and FA:CA of 1:7. GEOCRETE is indicated to have better engineering properties than does pervious concrete that is made of ordinary Portland cement.

  18. Engineering properties of lightweight geopolymer synthesized from coal bottom ash and rice husk ash

    Science.gov (United States)

    Thang, Nguyen Hoc; Hoa, Nguyen Ngoc; Quyen, Pham Vo Thi Ha; Tuyen, Nguyen Ngoc Kim; Anh, Tran Vu Thao; Kien, Pham Trung

    2018-04-01

    Geopolymer technology was developed by Joseph Davidovits in 1970s based on reactions among alumino-silicate resources in high alkaline conditions. Geopolymer has been recently gaining attention as an alternative binder for Ordinary Portland cement (OPC) due to its low energy and CO2 burden. The raw materials used for geopolymerization normally contain high SiO2 and Al2O3 in the chemical compositions such as meta-kaoline, rice husk ash, fly ash, bottom ash, blast furnace slag, red mud, and others. Moreover, in this paper, coal bottom ash (CBA) and rice husk ash (RHA), which are industrial and agricultural wastes, respectively, were used as raw materials with high alumino-silicate resources. Both CBA and RHA were mixed with sodium hydroxide (NaOH) solution for 20 minutes to obtain the geopolymer pastes. The pastes were filled in 5-cm cube molds according to ASTM C109/C109M 99, and then cured at room condition for hardening of the geopolymer specimens. After 24 hours, the specimens were removed out of the molds and continuously cured at room condition for 27 days. The geopolymer-based materials were then tested for engineering properties such as compressive strength (MPa), volumetric weight (kg/m3), and water absorption (kg/m3). Results indicated that the material can be considered lightweight with volumetric weight from 1192 to 1425 kg/m3; compressive strength at 28 days is in the range of 12.38 to 37.41 MPa; and water absorption is under 189.92 kg/m3.

  19. Environmental, physical and structural characterisation of geopolymer matrixes synthesised from coal (co-)combustion fly ashes

    International Nuclear Information System (INIS)

    Alvarez-Ayuso, E.; Querol, X.; Plana, F.; Alastuey, A.; Moreno, N.; Izquierdo, M.; Font, O.; Moreno, T.; Diez, S.; Vazquez, E.; Barra, M.

    2008-01-01

    The synthesis of geopolymer matrixes from coal (co-)combustion fly ashes as the sole source of silica and alumina has been studied in order to assess both their capacity to immobilise the potentially toxic elements contained in these coal (co-)combustion by-products and their suitability to be used as cement replacements. The geopolymerisation process has been performed using (5, 8 and 12 M) NaOH solutions as activation media and different curing time (6-48 h) and temperature (40-80 o C) conditions. Synthesised geopolymers have been characterised with regard to their leaching behaviour, following the DIN 38414-S4 [DIN 38414-S4, Determination of leachability by water (S4), group S: sludge and sediments. German standard methods for the examination of water, waste water and sludge. Institut fuer Normung, Berlin, 1984] and NEN 7375 [NEN 7375, Leaching characteristics of moulded or monolithic building and waste materials. Determination of leaching of inorganic components with the diffusion test. Netherlands Normalisation Institute, Delft, 2004] procedures, and to their structural stability by means of compressive strength measurements. In addition, geopolymer mineralogy, morphology and structure have been studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR), respectively. It was found that synthesised geopolymer matrixes were only effective in the chemical immobilisation of a number of elements of environmental concern contained in fly ashes, reducing (especially for Ba), or maintaining their leachable contents after the geopolymerisation process, but not for those elements present as oxyanions. Physical entrapment does not seem either to contribute in an important way, in general, to the immobilisation of oxyanions. The structural stability of synthesised geopolymers was mainly dependent on the glass content of fly ashes, attaining at the optimal activation conditions (12 M NaOH, 48 h, 80 o C

  20. Laparoscopic redo fundoplication for intrathoracic migration of wrap

    Directory of Open Access Journals (Sweden)

    Maheshkumar G

    2007-01-01

    Full Text Available Laparoscopic fundoplication is fast emerging as the treatment of choice of gastro-esophageal reflux disease. However, a complication peculiar to laparoscopic surgery for this disease is the intrathoracic migration of the wrap. This article describes a case of a male patient who developed this particular complication after laparoscopic total fundoplication. Following a trauma, wrap migration occurred. The typical history and symptomatology is described. The classical Barium swallow picture is enclosed. Laparoscopic redo fundoplication was carried out. The difficulties encountered are described. Postoperative wrap migration can be suspected clinically by the presence of a precipitating event and typical symptomatology. Confirmation is by a Barium swallow. Treatment is by redo surgery.

  1. IIA/B, Wound and Wrapped

    International Nuclear Information System (INIS)

    Danielsson, Ulf H.; Guijosa, Alberto; Kruczenski, Martin

    2000-01-01

    We examine the T-duality relation between 1+1 NCOS and the DLCQ limit of type IIA string theory. We show that, as long as there is a compact dimension, one can meaningfully define an 'NCOS' limit of IIB/A string theory even in the absence of D-branes (and even if there is no B-field). This yields a theory of closed strings with strictly positive winding, which is T-dual to DLCQ IIA/B without any D-branes. We call this the Type IIB/A Wound String Theory. The existence of decoupled sectors can be seen directly from the energy spectrum, and mirrors that of the DLCQ theory. It becomes clear then that all of the different p+1 NCOS theories are simply different states of this single Wound IIA/B theory which contain D-branes. We study some of the properties of this theory. In particular, we show that upon toroidal compactification, Wound string theory is U-dual to various Wrapped Brane theories which contain OM theory and the ODp theories as special states. (author)

  2. Fly Ash-based Geopolymer Lightweight Concrete Using Foaming Agent

    Directory of Open Access Journals (Sweden)

    Rafiza Abdul Razak

    2012-06-01

    Full Text Available In this paper, we report the results of our investigation on the possibility of producing foam concrete by using a geopolymer system. Class C fly ash was mixed with an alkaline activator solution (a mixture of sodium silicate and NaOH, and foam was added to the geopolymeric mixture to produce lightweight concrete. The NaOH solution was prepared by dilute NaOH pellets with distilled water. The reactives were mixed to produce a homogeneous mixture, which was placed into a 50 mm mold and cured at two different curing temperatures (60 °C and room temperature, for 24 hours. After the curing process, the strengths of the samples were tested on days 1, 7, and 28. The water absorption, porosity, chemical composition, microstructure, XRD and FTIR analyses were studied. The results showed that the sample which was cured at 60 °C (LW2 produced the maximum compressive strength for all tests, (11.03 MPa, 17.59 MPa, and 18.19 MPa for days 1, 7, and 28, respectively. Also, the water absorption and porosity of LW2 were reduced by 6.78% and 1.22% after 28 days, respectively. The SEM showed that the LW2 sample had a denser matrix than LW1. This was because LW2 was heat cured, which caused the geopolymerization rate to increase, producing a denser matrix. However for LW1, microcracks were present on the surface, which reduced the compressive strength and increased water absorption and porosity.

  3. Mechanical properties of geopolymer lightweight brick with styrofoam pellet

    Science.gov (United States)

    Abdullah, Mohd Mustafa Al Bakri; Tahir, Muhammad Faheem Mohd; Kadir, Aeslina Abdul; Hussin, Kamarudin; Samson, W. Saiful Iskandar W.

    2017-09-01

    The utilization of fly ash in brick as partial replacement of cement is gaining immense importance today, mainly on account of the improvement in the long-term durability of brick combined with ecological benefits. In this research, the lightweight brick was produced by using fly ash (class F) as a main material to replace Ordinary Portland Cement (OPC) in the composition of brick. Class F Fly Ash was mixed with an alkaline activator solution (a mixture of sodium silicate and NaOH), and styrofoam pellet was added to the geopolymer mixture to produce lightweight brick. The brick was prepared in two methods that is wet method and dry method due to different brick composition which is dry method for composition with sand and wet method for composition without sand. The bricks were cured in room temperature at 7 aging days. After 7 days, the compressive strength, water absorption, and density of the brick were investigated, where the optimum ratio for the best bricks has been determined from the lightweight density and has compressive strength more than minimum standard requirement. The best bricks are further produce for curing at 60°C in oven at 28 aging days. Those bricks also were characterized using optical microscope to measure the distribution of styrofoam in brick structure. From the result obtained, the brick that cured at 60°C in oven at 28 aging days has high strength compare to brick that cured in room temperature and at 7 day cured. The water absorption is decreasing as the curing temperature and aging days increased whereas density is increasing.

  4. EFFECT OF SODIUM SILICATE TO SODIUM HYDROXIDE RATIOS ON DURABILITY OF GEOPOLYMER MORTARS CONTAINING NATURAL AND ARTIFICIAL POZZOLANS

    Directory of Open Access Journals (Sweden)

    F. Nurhayat Degirmenci

    2017-09-01

    Full Text Available This study aims to provide the experimental data on the sulphate and acid performance of geopolymer mortar containing pozzolanic materials such as fly ash (FA, ground granulated blast furnace slag (GGBS and natural zeolite (NZ. The alkaline solution was the combination of sodium silicate and sodium hydroxide solution with the ratio (Na ₂SiO₃/NaOH of 1.0, 2.0 and 3.0. The molarity of sodium hydroxide was fixed as 10. The performances of geopolymer mortar were measured in terms of sodium and magnesium sulphate resistance and sulphuric and hydrochlorich acid resistance with 5% and 10 % concentration after 24 weeks. The evaluations were measured as visual observation, measurement of weight change and residual compressive strength. It has been observed that Na ₂SiO₃/NaOH ratio is effective on residual compressive strength of geopolymer mortar in both sulphate and acid exposure. The higher ratio of Na ₂SiO₃/NaOH results in a higher residual compressive strength. The GGBS based geopolymer mortar has a very good resistance in acid media in terms of weight loss and residual compressive strength. The inclusion of FA in the GGBS based geopolymer mixture was found to be a suitable base of geopolymer mortar under ambient curing conditions.

  5. Development of wire wrapping technology for FBR fuel pin

    International Nuclear Information System (INIS)

    Nogami, Tetsuya; Seki, Nobuo; Sawayama, Takeo; Ishibashi, Takashi

    1991-01-01

    For the FBR fuel assembly, the spacer wire is adopted to maintain the space between fuel pins. The developments have been carried out to achieve automatically wire wrapping with high precision. Based on the fundamental technology developed through the mock-up test operation, Joyo 'MK-I', fuel pin fabrication was started using partially mechanized wire wrapping machine in 1973. In 1978, an automated wire wrapping machine for Joyo 'MK-II' was developed by the adoption of some improvements for the wire inserting system to end plug hole and the precision of wire pitch. On the bases of these experiences, fully automated wire wrapping machine for 'Monju' fuel pin was installed at Plutonium Fuel Production Facility (PFPF) in 1987. (author)

  6. Thermal hydraulic evaluation of advanced wire-wrapped assemblies

    International Nuclear Information System (INIS)

    Wei, J.P.

    1975-01-01

    The thermal-hydraulic analyses presented in this report are based on application of the subchannel concept in association with the use of bulk parameters for coolant velocity and coolant temperature within a subchannel. The interactions between subchannels are due to turbulent interchange, pressure-induced diversion crossflow, directed sweeping crossflow induced by the helical wire wrap, and transverse thermal conduction. The FULMIX-II computer program was successfully developed to perform the steady-state temperature predictions for LMFBR fuel assemblies with the reference straight-start design and the advanced wire-wrap designs. Predicted steady-state temperature profiles are presented for a typical CRBRP 217-rod wire-wrapped assembly with the selected wire-wrap designs

  7. Waste Receiving and Processing (WRAP) Weight Scale Analysis Results

    International Nuclear Information System (INIS)

    JOHNSON, M.D.

    2000-01-01

    Fairbanks Weight Scales are used at the Waste Receiving and Processing (WRAP) facility to determine the weight of waste drums as they are received, processed, and shipped. Due to recent problems, discovered during calibration, the WRAP Engineering Department has completed this document which outlines both the investigation of the infeed conveyor scale failure in September of 1999 and recommendations for calibration procedure modifications designed to correct deficiencies in the current procedures

  8. Assessment of SFR Wire Wrap Simulation Uncertainties

    Energy Technology Data Exchange (ETDEWEB)

    Delchini, Marc-Olivier G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Reactor and Nuclear Systems Division; Popov, Emilian L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Reactor and Nuclear Systems Division; Pointer, William David [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Reactor and Nuclear Systems Division; Swiler, Laura P. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-09-30

    Predictive modeling and simulation of nuclear reactor performance and fuel are challenging due to the large number of coupled physical phenomena that must be addressed. Models that will be used for design or operational decisions must be analyzed for uncertainty to ascertain impacts to safety or performance. Rigorous, structured uncertainty analyses are performed by characterizing the model’s input uncertainties and then propagating the uncertainties through the model to estimate output uncertainty. This project is part of the ongoing effort to assess modeling uncertainty in Nek5000 simulations of flow configurations relevant to the advanced reactor applications of the Nuclear Energy Advanced Modeling and Simulation (NEAMS) program. Three geometries are under investigation in these preliminary assessments: a 3-D pipe, a 3-D 7-pin bundle, and a single pin from the Thermal-Hydraulic Out-of-Reactor Safety (THORS) facility. Initial efforts have focused on gaining an understanding of Nek5000 modeling options and integrating Nek5000 with Dakota. These tasks are being accomplished by demonstrating the use of Dakota to assess parametric uncertainties in a simple pipe flow problem. This problem is used to optimize performance of the uncertainty quantification strategy and to estimate computational requirements for assessments of complex geometries. A sensitivity analysis to three turbulent models was conducted for a turbulent flow in a single wire wrapped pin (THOR) geometry. Section 2 briefly describes the software tools used in this study and provides appropriate references. Section 3 presents the coupling interface between Dakota and a computational fluid dynamic (CFD) code (Nek5000 or STARCCM+), with details on the workflow, the scripts used for setting up the run, and the scripts used for post-processing the output files. In Section 4, the meshing methods used to generate the THORS and 7-pin bundle meshes are explained. Sections 5, 6 and 7 present numerical results

  9. Deflection hardening behaviour of short fibre reinforced fly ash based geopolymer composites

    International Nuclear Information System (INIS)

    Shaikh, F.U.A.

    2013-01-01

    Highlights: • Deflection hardening behaviour is achieved in the DFRGC similar to that observed in DFRCC. • The first crack load or in other word the limit of proportionality (LOP) of DFRGC is similar to that of DFRCC. • The DFRGC also exhibited higher deflection at peak load than DFRCC. • The toughness at peak load of DFRGC is also high than that of DFRCC. • The ductility of DFRGC is also higher than that of DFRCC. - Abstract: This paper reports the newly developed ductile fibre reinforced geopolymer composite (DFRGC) exhibiting deflection hardening and multiple cracking behaviour. The binder of the above composite is different from that used in conventional cement based system. The class F fly ash is used instead of Portland cement in DFRGC and is activated by alkaline liquids (sodium hydroxide and sodium silicate). In this study, two types of fibres namely steel (ST) and polyvinyl alcohol (PVA) fibres are used in mono as well as in ST–PVA hybrid form, with a total volume fraction of 2%. The deflection hardening behaviour of newly developed DFRGC is also compared with that of conventional ductile fibre reinforced cementitious composites (DFRCC). The effects of two different sizes of sand (1.18 mm, and 0.6 mm) and sand/binder ratios of 0.5 and 0.75 on the deflection hardening and multiple cracking behaviour of both DFRGC and DFRCC are also evaluated. Results revel that the deflection hardening and multiple cracking behaviour is achieved in geopolymer based DFRGC similar to that of cement based system. For a given sand size and sand content, comparable deflection hardening behaviour, ultimate flexural strength and the deflection at peak load are observed in both cement and geopolymer based composites irrespective of fibre types and combination. The deflection hardening behaviour of DFRGC is also confirmed by the calculated toughness index values of I 20 > 20. The scanning electron microscope (SEM) study shows no degradation of PVA and steel fibres in the

  10. Modeling Stone Columns.

    Science.gov (United States)

    Castro, Jorge

    2017-07-11

    This paper reviews the main modeling techniques for stone columns, both ordinary stone columns and geosynthetic-encased stone columns. The paper tries to encompass the more recent advances and recommendations in the topic. Regarding the geometrical model, the main options are the "unit cell", longitudinal gravel trenches in plane strain conditions, cylindrical rings of gravel in axial symmetry conditions, equivalent homogeneous soil with improved properties and three-dimensional models, either a full three-dimensional model or just a three-dimensional row or slice of columns. Some guidelines for obtaining these simplified geometrical models are provided and the particular case of groups of columns under footings is also analyzed. For the latter case, there is a column critical length that is around twice the footing width for non-encased columns in a homogeneous soft soil. In the literature, the column critical length is sometimes given as a function of the column length, which leads to some disparities in its value. Here it is shown that the column critical length mainly depends on the footing dimensions. Some other features related with column modeling are also briefly presented, such as the influence of column installation. Finally, some guidance and recommendations are provided on parameter selection for the study of stone columns.

  11. PERFORMANCE EVALUATION OF AN INNOVATIVE FIBER REINFORCED GEOPOLYMER SPRAY-APPLIED MORTAR FOR LARGE DIAMETER WASTEWATER MAIN REHABILITATION IN HOUSTON, TX

    Science.gov (United States)

    This report describes the performance evaluation of a fiber reinforced geopolymer spray-applied mortar, which has potential as a structural alternative to traditional open cut techniques used in large-diameter sewer pipes. Geopolymer is a sustainable green material that incorpor...

  12. THE CHARACTERIZATION OF THE Ca-K GEOPOLYMER/SOLIDIFIED FLUID FLY-ASH INTERLAYER

    Directory of Open Access Journals (Sweden)

    Ivana Perna

    2016-12-01

    Full Text Available A Ca-K geopolymer matrix based on clay material and blast-furnace slag was filled with aggregates, ash pellets made from fluid fly ash, and the interlayer formed between the two components was studied. The scanning electron-microscopy investigation of the inseparable interlayer demonstrated that the pellets were not only enveloped in a geopolymer matrix but also incorporated through a thin, yet identifiable, surface pellet layer. The migration of calcium and potassium ions was detected and that changes in the quantity of these ions arise from their mobility. The interlayer on the edges of ash pellets was also studied by infrared analysis, which in this layer proved bands belonging to both participants, the matrix and the pellets. Based on the results, two different materials prepared from wastes could be used for the preparation of a new composite material and thus facilitate waste-material disposal.

  13. INVESTIGATING THE EFFECTS OF OIL PALM ASH IN METAKAOLIN BASED GEOPOLYMER

    Directory of Open Access Journals (Sweden)

    Hawa A.

    2013-12-01

    Full Text Available This research reports on the microstructure, compressive strength, drying shrinkage and sulfate expansion of metakaolin (MK based geopolymers produced by partially replacing MK by oil palm ash (OPA in proportions of 0 %, 5 %, 10 % and 15 % by weight. The specimens were cured at a temperature of 80°C for 1, 2 and 4 hours, and compressive strength test were conducted at ambient temperature at 2, 6, 24 hours, 7 and 28 day. The testing results revealed that the geopolymer with 5 % OPA gave the highest compressive strength. Scanning electron microscopy (SEM indicated that the 5 % OPA sample had a dense-compact matrix and less unreacted raw materials which contributed to the higher compressive strength. In the X-ray diffraction (XRD patterns, the change of the crystalline phase for higher strength was easily detectable compared lower strength.

  14. The relationship between compressive strength and flexural strength of pavement geopolymer grouting material

    Science.gov (United States)

    Zhang, L.; Han, X. X.; Ge, J.; Wang, C. H.

    2018-01-01

    To determine the relationship between compressive strength and flexural strength of pavement geopolymer grouting material, 20 groups of geopolymer grouting materials were prepared, the compressive strength and flexural strength were determined by mechanical properties test. On the basis of excluding the abnormal values through boxplot, the results show that, the compressive strength test results were normal, but there were two mild outliers in 7days flexural strength test. The compressive strength and flexural strength were linearly fitted by SPSS, six regression models were obtained by linear fitting of compressive strength and flexural strength. The linear relationship between compressive strength and flexural strength can be better expressed by the cubic curve model, and the correlation coefficient was 0.842.

  15. Characterization of bauxite mud of Alumar to be used as a geopolymer

    International Nuclear Information System (INIS)

    Soares, A.F.B.; Cartaxo, J.M.; Sousa, B.V.; Menezes, R.R.

    2011-01-01

    The process of Geopolymerization aluminium-siliceous materials has prompted several scientific works to develop materials with interesting thermomechanical properties. Currently, one of the problems encountered by the industries responsible for the production of aluminum is the waste from the Bayer process, known as mud bauxite. In our study, the characterization of bauxite (fresh) and residue from two different lakes company ALUMAR to be applied in obtaining geopolymers. Through the results of analysis by X-ray fluorescence (EDX) was observed after the Bayer process, the presence of oxides of sodium, silicon, aluminum and iron in larger quantities. It was found through a combination of diffraction and vibration obtained by infrared spectrometry the presence of silicates and aluminate groups. Thus, the analyzed material will be activated and tested as geopolymer. (author)

  16. Synthesis and Characterization of Functional Composite Carbon-Geopolymers for Precast Panel Application

    Directory of Open Access Journals (Sweden)

    Noor Afifah Kharisma

    2017-01-01

    Full Text Available The purpose of this study is to examine the influence of carbon (C particles as filler (aggregate in the production of geopolymers functional composite for possible precast panel application. Geopolymers was synthesized through alkali activation of metakaolin added with carbon particles relative to the mass of metakaolin. The mixture was cured at 70°C for 2 hours and the resulting composites were stored in open air for 28 days. The bulk density and the apparent porosity of the composites were measured by using Archimedes method. The thermal properties of the samples was examined by using thermal conductivity measurement and differential scanning calorimetry (DSC. The microstructure characterization of the samples were performed by using x-ray diffraction (XRD and Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS.

  17. High tensile strength fly ash based geopolymer composite using copper coated micro steel fiber

    DEFF Research Database (Denmark)

    Ranjbar, Navid; Mehrali, Mehdi; Mehrali, Mohammad

    2016-01-01

    -matrix interaction. In this present study, effects of micro steel fibers (MSF) incorporation on mechanical properties of fly ash based geopolymer was investigated at different volume ratio of matrix. Various properties of the composite were compared in terms of fresh state by flow measurement and hardened state......As a ceramic-like material, geopolymers show a high quasi-brittle behavior and relatively low fracture energy. To overcome this, the addition of fibers to a brittle matrix is a well-known method to improve the flexural strength. Moreover, the success of the reinforcements is dependent on the fiber...... by variation of shrinkage over time to assess performance of the composites subjected to flexural and compressive load. The fiber-matrix interface, fiber surface and toughening mechanisms were assessed using field emission scan electron microscopy (FESEM) and atomic force microscopy (AFM) through a period...

  18. The characterization of the Ca–K geopolymer/solidified fluid fly-ash interlayer

    Czech Academy of Sciences Publication Activity Database

    Perná, Ivana; Šupová, Monika; Hanzlíček, Tomáš

    2017-01-01

    Roč. 61, č. 1 (2017), s. 26-33 ISSN 0862-5468 Institutional support: RVO:67985891 Keywords : fluid fly ash * blast-furnace slag * geopolymer * interlayer * recycling Subject RIV: DM - Solid Waste and Recycling OBOR OECD: Composites (including laminates, reinforced plastics, cermets, combined natural and synthetic fibre fabrics Impact factor: 0.439, year: 2016 https://www.irsm.cas.cz/materialy/cs_content/2016_doi/Perna_CS_2016_0056.pdf

  19. Investigation into Suitability of Geopolymers (Illite & Metakaolin) for the Space Environment

    Science.gov (United States)

    2012-09-13

    TML Total mass loss ULE Ultra low expansion (glass) UV Ultraviolet VOC Volatile organic compound VUV Vacuum ultraviolet XPS X-ray photoelectron...hour time period at 125 deg C and less than 5 x 10 -5 torr. CVCM is the amount of volatiles that will condense on a collector plate controlled to...complex shapes (such as parabolic solids) can be made by pouring the uncured material over a mold. Additionally, geopolymers have an adhesive quality

  20. Contributions to the study of porosity in fly ash-based geopolymers. Relationship between degree of reaction, porosity and compressive strength

    Directory of Open Access Journals (Sweden)

    Y. Luna-Galiano

    2016-09-01

    Full Text Available The main contribution of this paper relates to the development of a systematic study involving a set of parameters which could potentially have an impact on geopolymer properties: curing temperature, type of activating solution, alkali metal in solution, incorporation of slag (Ca source and type of slag used. The microstructures, degrees of reaction, porosities and compressive strengths of geopolymers have been evaluated. Geopolymers prepared with soluble silicate presented a more compacted and closed structure, a larger amount of gel, lower porosity and greater compressive strength than those prepared with hydroxides. On the other hand, Na-geopolymers were more porous but more resistant than K-geopolymers. Although there is an inverse relation between degree of reaction and porosity, between compressive strength and porosity it is not always inversely proportional and could, in some cases, be masked by changes produced in other influencing parameters.

  1. Influence of formulation parameters on the texturing and and the structural evolution of geo-polymers

    International Nuclear Information System (INIS)

    Steins, Prune

    2014-01-01

    In the context of conditioning of nuclear waste, geo-polymers represent a potential alternative to conventional hydraulic binders. Currently, it is recognized that the formation of geo-polymer proceeds according to a mechanism of dissolution - restructuring - polymerization resulting in a solid material. Despite the availability of many studies to understand these mechanisms, the precise relationship between the chemical nature of the activating solution, the geo-polymerization process and the final microstructure should be determined from the point of view of the texturing and the structural evolution of the material. In this work, several parameters were studied: the nature of the alkali activator, the silica concentration and the addition of an aluminum source. It appears that the chemical environment of the silicate or aluminosilicate precursors is controlled by the activating solution composition. During the consolidation of the geo-polymer network, these precursors play an important role on the dissolution rate of meta kaolin, the size, the rearrangement and the aggregation of aluminosilicate oligomers involved in the porous solid network formation. Subsequently, some characteristics of the porous network which are controlled by the size and the rearrangement of oligomers vary slightly over time. The refinement of the porosity associated to first, a densification of the solid network, and secondly, a partial closure of the porosity at the nanometer scale leads to an increase in the pore size and a decrease of the pore volume. (author) [fr

  2. Superplasticizer Addition to Carbon Fly Ash Geopolymers Activated at Room Temperature.

    Science.gov (United States)

    Carabba, Lorenza; Manzi, Stefania; Bignozzi, Maria Chiara

    2016-07-18

    Present concerns about global warming due to the greenhouse emissions in the atmosphere have pushed the cement industry to research alternatives to ordinary Portland cement (OPC). Geopolymer binder may constitute a possible breakthrough in the development of sustainable materials: understanding the effectiveness and the influences of superplasticizers on geopolymer systems is one of the essential requirements for its large-scale implementation. This study aims to investigate the possibility of using commercially available chemical admixtures designed for OPC concrete, to improve fresh properties of fly ash-based geopolymers and mortars. A special emphasis is laid upon evaluating their influence on mechanical and microstructural characteristics of the hardened material realized under room-temperature curing conditions. Results indicate that the addition of a polycarboxylic ether-based superplasticizer, in the amount of 1.0 wt. % by mass of fly ash, promotes an improvement in workability without compromising the final strength of the hardened material. Moreover, the addition of the polycarboxylic ether- and acrylic-based superplasticizers induces a refinement in the pore structure of hardened mortar leading to a longer water saturation time.

  3. Hybrid optical-fibre/geopolymer sensors for structural health monitoring of concrete structures

    Science.gov (United States)

    Perry, M.; Saafi, M.; Fusiek, G.; Niewczas, P.

    2015-04-01

    In this work, we demonstrate hybrid optical-fibre/geopolymer sensors for monitoring temperature, uniaxial strain and biaxial strain in concrete structures. The hybrid sensors detect these measurands via changes in geopolymer electrical impedance, and via optical wavelength measurements of embedded fibre Bragg gratings. Electrical and optical measurements were both facilitated by metal-coated optical fibres, which provided the hybrid sensors with a single, shared physical path for both voltage and wavelength signals. The embedded fibre sensors revealed that geopolymer specimens undergo 2.7 mɛ of shrinkage after one week of curing at 42 °C. After curing, an axial 2 mɛ compression of the uniaxial hybrid sensor led to impedance and wavelength shifts of 7 × 10-2 and -2 × 10-4 respectively. The typical strain resolution in the uniaxial sensor was 100 μ \\varepsilon . The biaxial sensor was applied to the side of a concrete cylinder, which was then placed under 0.6 mɛ of axial, compressive strain. Fractional shifts in impedance and wavelength, used to monitor axial and circumferential strain, were 3 × 10-2 and 4 × 10-5 respectively. The biaxial sensor’s strain resolution was approximately 10 μ \\varepsilon in both directions. Due to several design flaws, the uniaxial hybrid sensor was unable to accurately measure ambient temperature changes. The biaxial sensor, however, successfully monitored local temperature changes with 0.5 °C resolution.

  4. SORPTION OF CESIUM USING KZnFc ON PHOSPHORIC ACID-BASED GEOPOLYMER

    Directory of Open Access Journals (Sweden)

    Li-Ching Chuang

    2015-06-01

    Full Text Available The adsorbent was synthesized from the acid-base reaction between metal ferrocyanide and acidic phosphate at room temperature. The metal ferrocyanide granular inorganic adsorbent based on phosphate geopolymer for the removal of cesium in either batch or packed-bed operation has been developed in this study. In this work, the compressive strength of granular inorganic adsorbent was investigated under different liquid-to-solid, metal ferrocyanide-to-geopolymer and MgO-to-KH2PO4 ratios. The result showed that the compressive strength of the adsorbent increased with the increase of MgO-to- KH2PO4 ratio. It was found that the optimization of metal ferrocyanide-to-geopolymer and MgO-to- KH2PO4 ratios was important in improving both the compressive strength and the adsorption capacity of the adsorbent. The metal ferrocyanide granular inorganic adsorbent prepared were characterized by analysis such as XRD, TGA, FTIR and SEM spectra. In this study, the synthesized granular inorganic adsorbent has demonstrated a Cs removal efficiency of over 99 % and an adsorption capacity of 1.7-1.8 meq.g-1 in simulation wastewater containing 2000 ppm Cs under adsorbent dose of 0.0067 g.ml-1.

  5. Low-reactive circulating fluidized bed combustion (CFBC) fly ashes as source material for geopolymer synthesis

    International Nuclear Information System (INIS)

    Xu Hui; Li Qin; Shen Lifeng; Zhang Mengqun; Zhai Jianping

    2010-01-01

    In this contribution, low-reactive circulating fluidized bed combustion (CFBC) fly ashes (CFAs) have firstly been utilized as a source material for geopolymer synthesis. An alkali fusion process was employed to promote the dissolution of Si and Al species from the CFAs, and thus to enhance the reactivity of the ashes. A high-reactive metakaolin (MK) was also used to consume the excess alkali needed for the fusion. Reactivities of the CFAs and MK were examined by a series of dissolution tests in sodium hydroxide solutions. Geopolymer samples were prepared by alkali activation of the source materials using a sodium silicate solution as the activator. The synthesized products were characterized by mechanical testing, scanning electron microscopy (SEM), X-ray diffractography (XRD), as well as Fourier transform infrared spectroscopy (FTIR). The results of this study indicate that, via enhancing the reactivity by alkali fusion and balancing the Na/Al ratio by additional aluminosilicate source, low-reactive CFAs could also be recycled as an alternative source material for geopolymer production.

  6. Waste Foundry Sand Usage for Building Material Production: A First Geopolymer Record in Material Reuse

    Directory of Open Access Journals (Sweden)

    Neslihan Doğan-Sağlamtimur

    2018-01-01

    Full Text Available In order to bring a solution to the problem of waste foundry sand (WFS in the foundry sector and achieve its reuse, geopolymer building material (as a cementless technology was produced from the WFS for the first time in the literature in this study. The physical and mechanical characteristics of this material were determined. In the first part of the experimental step, the sieve analysis, loose/tight unit weight, and loss of ignition of the WFS were obtained as well as the ultimate analysis. In the second step, the water absorption percentage, porosity, unit weight, and compressive strength tests were conducted on the WFS-based geopolymer specimens activated by chemical binders (sodium hydroxide: NaOH and sodium silicate: Na2SiO3. As the unit weights of all the produced samples were lower than 1.6 g/cm3, they may be considered as lightweight building materials. The minimum compressive strength value for building wall materials was accepted as 2.5 MPa by national standards. In this study, the maximum compressive strength value was measured as 12.3 MPa for the mixture incorporation of 30% Na2SiO3 at the curing temperature of 200°C in 28 days. It was concluded that this geopolymer material is suitable for using as a building wall material.

  7. Elasticity and expansion test performance of geopolymer as oil well cement

    Science.gov (United States)

    Ridha, S.; Hamid, A. I. Abd; Halim, A. H. Abdul; Zamzuri, N. A.

    2018-04-01

    History has shown that geopolymer cement provides high compressive strength as compared to Class G cement. However, the research had been done at ambient temperature, not at elevated condition which is the common oil well situation. In this research, the physical and mechanical properties performance of the oil well cement were investigated by laboratory work for two types of cement that are geopolymer and Class G cement. The cement samples were produced by mixing the cement according to the API standards. Class C fly ash was used in this study. The alkaline solution was prepared by mixing sodium silicate with NaOH solution. The NaOH solution was prepared by diluting NaOH pellets with distilled water to 8M. The cement samples were cured at a pressure of 3000 psi and a temperature of 130 °C to simulate the downhole condition. After curing, the physical properties of the cement samples were investigated using OYO Sonic Viewer to determine their elastic properties. Autoclave expansion test and compressive strength tests were conducted to determine the expansion value and the strength of the cement samples, respectively. The results showed that the geopolymer cement has a better physical and mechanical properties as compared with Class G cement at elevated condition.

  8. Optimum mix for fly ash geopolymer binder based on workability and compressive strength

    Science.gov (United States)

    Arafa, S. A.; Ali, A. Z. M.; Awal, A. S. M. A.; Loon, L. Y.

    2018-04-01

    The request of concrete is increasing every day for sustaining the necessity of development of structure. The production of OPC not only consumes big amount of natural resources and energy, but also emit significant quantity of CO2 to the atmosphere. Therefore, it is necessary to find alternatives like Geopolymer to make the concrete environment friendly. Geopolymer is an inorganic alumino-silicate compound, produced from fly ash. This paper describes the experimental work conducted by casting 40 geopolymer paste mixes, and was cured at 80°C for 24 h to evaluate the effect of various parameters affecting the workability and compressive strength. Alkaline solution to fly ash ratio and sodium hydroxide (NaOH) concentration were chosen as the key parameters of strength and workability. Laboratory investigation with different percentage of sodium hydroxide concentration and different alkaline liquid to fly ash ratio reveals that the optimum ratios are 10 M, AL/FA=0.5. It has generally been found that the workability decreased and the compressive strength increased with an increase in the concentration of sodium hydroxide solution. However, workability was increased and the compressive strength was decreased with the increase in the ratio of fly ash to alkaline solution.

  9. A Study of Hybrid Composite Hydroxyapatite (HA-Geopolymers as a Material for Biomedical Application

    Directory of Open Access Journals (Sweden)

    Saleha

    2017-01-01

    Full Text Available The main purpose of this research is to study the physical properties and microstructure characters of hybrid composites HA-geopolymers as a material for biomedical application. Hybrid composite HA–geopolymers were produced through alkaline activation method of metakaolin as a matrix and HA as the filler. HA was synthesized from eggshell particles by using a precipitation method. The addition of HA in metakaolin paste was varied from 0.5%, 1.0%, 1.5%, and 2.0% relative the weight of metakaolin. FTIR was used to examine the absorption bands the composites. X-ray diffraction (XRD was used to study the crystal structure of the starting and the resulting materials. Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS was used to investigate the surface morphology of the composites. The thermal properties of the samples was examined by means of Differential Scanning Calorimetry (DSC. Capacitance measurement was conducted to investigate the bioactive properties of HA. The study results suggest that hybrid composite HA-geopolymers has a potential to be applied as a biomedical such as biosensor material.

  10. A Comprehensive Study of the Polypropylene Fiber Reinforced Fly Ash Based Geopolymer.

    Directory of Open Access Journals (Sweden)

    Navid Ranjbar

    Full Text Available As a cementitious material, geopolymers show a high quasi-brittle behavior and a relatively low fracture energy. To overcome such a weakness, incorporation of fibers to a brittle matrix is a well-known technique to enhance the flexural properties. This study comprehensively evaluates the short and long term impacts of different volume percentages of polypropylene fiber (PPF reinforcement on fly ash based geopolymer composites. Different characteristics of the composite were compared at fresh state by flow measurement and hardened state by variation of shrinkage over time to assess the response of composites under flexural and compressive load conditions. The fiber-matrix interface, fiber surface and toughening mechanisms were assessed using field emission scan electron microscopy (FESEM and atomic force microscopy (AFM. The results show that incorporation of PPF up to 3 wt % into the geopolymer paste reduces the shrinkage and enhances the energy absorption of the composites. While, it might reduce the ultimate flexural and compressive strength of the material depending on fiber content.

  11. ( Anogeissus leiocarpus ) timber columns

    African Journals Online (AJOL)

    A procedure for designing axially loaded Ayin (Anogeissus leiocarpus) wood column or strut has been investigated. Instead of the usual categorization of columns into short, intermediate and slender according to the value of slenderness ratio, a continuous column formula representing the three categories was derived.

  12. Column Liquid Chromatography.

    Science.gov (United States)

    Majors, Ronald E.; And Others

    1984-01-01

    Reviews literature covering developments of column liquid chromatography during 1982-83. Areas considered include: books and reviews; general theory; columns; instrumentation; detectors; automation and data handling; multidimensional chromatographic and column switching techniques; liquid-solid chromatography; normal bonded-phase, reversed-phase,…

  13. WRAP module 1 DMS/PCS interface definition document

    International Nuclear Information System (INIS)

    Weidert, J.R.

    1994-01-01

    This document has been developed to define the computer software interfaces between Waste Receiving ampersand Processing Module 1 (WRAP 1) computer systems. The interfaces include those data interfaces which exist between the Plant Control System (PCS) and Data Management System (DMS), between the DMS and Non-Destructive Assay (NDA) equipment, and between the DMS and Boxed Waste Assay System (BWAS) equipment. In addition to the data interfaces between the various WRAP computer systems; there are also a number of control functions between WRAP 1 equipment. These control function interfaces have been specified in WRAP Construction specification 13462 and the associated equipment specifications. The PCS vendor has been listed in the equipment specifications as the responsible party for establishing the final control system interface between the PCS and Non-Destructive Examination (NDE) Equipment, the PCS and Non-Destructive Assay (NDA) Equipment, and the PCS and BWAS equipment. The primary interface requirements between these systems are addressed in Specification Sections 13462, 13532, 13533, 13026, 13537, and 13538. Additional requirements may be found in other specification sections such as the Automatic Stacker Retriever System (AS/RS) Technical Specification 14520 and the WRAP 1 Data Management System Software Requirements Specification

  14. High calcium fly ash geopolymer stabilized lateritic soil and granulated blast furnace slag blends as a pavement base material.

    Science.gov (United States)

    Phummiphan, Itthikorn; Horpibulsuk, Suksun; Rachan, Runglawan; Arulrajah, Arul; Shen, Shui-Long; Chindaprasirt, Prinya

    2018-01-05

    Granulated Blast Furnace Slag (GBFS) was used as a replacement material in marginal lateritic soil (LS) while class C Fly Ash (FA) was used as a precursor for the geopolymerization process to develop a low-carbon pavement base material at ambient temperature. Unconfined Compression Strength (UCS) tests were performed to investigate the strength development of geopolymer stabilized LS/GBFS blends. Scanning Electron Microscopy and X-ray Diffraction analysis were undertaken to examine the role of the various influencing factors on UCS development. The influencing factors studied included GBFS content, Na 2 SiO 3 :NaOH ratio (NS:NH) and curing time. The 7-day soaked UCS of FA geopolymer stabilized LS/GBFS blends at various NS:NH ratios tested was found to satisfy the specifications of the Thailand national road authorities. The GBFS replacement was found to be insignificant for the improvement of the UCS of FA geopolymer stabilized LS/GBFS blends at low NS:NH ratio of 50:50. Microstructural analysis indicated the coexistence of Calcium Silicate Hydrate (CSH) and Sodium Alumino Silicate Hydrate products in FA geopolymer stabilized LS/GBFS blends. This research enables GBFS, which is traditionally considered as a waste material, to be used as a replacement and partially reactive material in FA geopolymer pavement applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Synthesis of a one-part geopolymer system for soil stabilizer using fly ash and volcanic ash

    Directory of Open Access Journals (Sweden)

    Tigue April Anne S.

    2018-01-01

    Full Text Available A novel approach one-part geopolymer was employed to investigate the feasibility of enhancing the strength of in-situ soil for possible structural fill application in the construction industry. Geopolymer precursors such as fly ash and volcanic ash were utilized in this study for soil stabilization. The traditional geopolymer synthesis uses soluble alkali activators unlike in the case of ordinary Portland cement where only water is added to start the hydration process. This kind of synthesis is an impediment to geopolymer soil stabilizer commercial viability. Hence, solid alkali activators such as sodium silicate (SS, sodium hydroxide (SH, and sodium aluminate (SA were explored. The influence of amount of fly ash (15% and 25%, addition of volcanic ash (0% and 12.5%, and ratio of alkali activator SS:SH:SA (50:50:0, 33:33:33, 50:20:30 were investigated. Samples cured for 28 days were tested for unconfined compressive strength (UCS. To evaluate the durability, sample yielding highest UCS was subjected to sulfuric acid resistance test for 28 days. Analytical techniques such as X-ray fluorescence (XRF, X-ray diffraction (XRD, and scanning electron microscope/energy-dispersive X-ray spectroscopy (SEM/EDX were performed to examine the elemental composition, mineralogical properties, and microstructure of the precursors and the geopolymer stabilized soil.

  16. Comparative Study on the Performance of Blended and Nonblended Fly Ash Geopolymer Composites as Durable Construction Materials

    Directory of Open Access Journals (Sweden)

    Debabrata Dutta

    2018-01-01

    Full Text Available This article represents that the mechanical and microstructural properties and durability of fly ash-based geopolymers blended with silica fume and borax are better than those of conventional fly ash-based geopolymers. Fly ash itself contains the sources of silica and alumina which are required for geopolymerisation. But a sufficient amount of high-reactive silica is able to rapidly initiate geopolymerisation with activation. Pure potassium hydroxide pellets and sodium silicate solution were used for preparation of alkaline activator solution. Fly ash geopolymer paste exhibited better mechanical properties in the presence of silica fume with slight portion of borax. The effect of silica fume-blended geopolymer paste on temperature fluctuation (heating and cooling cycle at certain temperatures showed better performance than nonblended fly ash-based specimens. Durability property was evaluated by immersion of geopolymer specimens in 10% magnesium sulfate solution for a period of one year. The change in weight, strength, and microstructure was studied and compared. In the magnesium sulfate solution, a significant drop of strength to around 37.26% occurred after one year for nonblended fly ash-based specimens. It is evident that specimens prepared incorporating silica fume had the best performance in terms of their properties.

  17. The Properties of Nano TiO2-Geopolymer Composite as a Material for Functional Surface Application

    Directory of Open Access Journals (Sweden)

    Syamsidar D.

    2017-01-01

    Full Text Available The aim of this study is to examine the properties of Nano TiO2-geopolymer as a material for functional surface applications such as walls, floors, bench top, arts and decoration materials. Class-C fly ash and metakaolin were used as raw materials to produce geopolymers pastes (binder. Geopolymers were synthesized through alkali activation method cured at 50°C for 2 hours using molar oxide ratios of SiO2/Al2O3 = 3.0, Na2O/SiO2 = 0.2, and H2O/Na2O = 10. Nano TiO2 was added into geopolymers paste at different concentration namely 0 wt%, 5wt%, 10wt% and 15wt % relative the weight of fly ash or metakaolin. The measurements were commenced after the samples aged 7 days. The samples made from fly ash were immersed in 1 M H2SO4 solution for 3 days for acid resistance examination. The self-cleaning properties of the composites were observed by immersing the sample into red clays solution. The X-Ray Diffraction (XRD was performed to examine the structure and phase of the samples before and after acid resistance measurement. Scanning Electron Microscopy (SEM was performed to examine the surface morphology of the resulting composites. The measurements results showed that Nano TiO2–geopolymers composite can be applied as functionally surface materials.

  18. Mechanical behavior of confined self-compacting reinforced concrete circular columns under concentric axial loading

    Directory of Open Access Journals (Sweden)

    Fouad Khairallah

    2013-12-01

    Full Text Available While there is abundant research information on ordinary confined concrete, there are little data on the behavior of Self-Compacting Concrete (SCC under such condition. Due to higher shrinkage and lower coarse aggregate content of SCC compared to that of Normal Concrete (NC, its composite performance under confined conditions needs more investigation. This paper has been devoted to investigate and compare the mechanical behavior of confined concrete circular columns cast with SCC and NC under concentric axial loading. The parameters affecting are including concrete compressive strength and confinement configuration. Twenty column specimens were casted and confined using four confinement techniques, CFRP wrap, FRP tube, GFRP wrap, and spiral steel hoops. The performance of the tested column specimens is evaluated based on mode of failure, load–displacement curve, stress–strain characteristics, ultimate strength, ductility, and degree of confinement.

  19. Development of geopolymers as candidate materials for low/intermediate level highly alkaline nuclear waste

    International Nuclear Information System (INIS)

    Perera, D.S.; Vance, E.R.; Kiyama, S.; Aly, Z.; Yee, P.

    2006-01-01

    Full text: Geopolymers have been studied for many years as a possible improvement on cement in respect of compressive strength, resistance to fire, heat and acidity, and as a medium for the encapsulation of hazardous or low/ intermediate level radioactive waste. They are made by adding aluminosilicates to concentrated alkali solutions and the application of heat at 0 Cfor subsequent polymerisation. In this work we studied them as suitable candidate materials to incorporate NaOH/NaA10 2 containing waste with low levels of Cs, Sr and Nd. Geopolymers were produced by incorporating the highly alkaline solution as part of the composition with added metakaolinite, fumed silica and extra NaOH, such that the overall geopolymer composition was of molar ratios Si/Al = 2 and Na/Al = 1. The simulated waste contained Na2SO 4 , therefore Ba(OH) 2 was also added to precipitate the SO 4 x 2 as BaSO 4 . Three geoplymers of the same composition containing simulated wastes were leach tested in triplicate after heating at 400 0 Cfor 1 h (to remove -98% of free and interstitial water) under the PCT-B test protocol at 90 0 Cfor 7 days and their results are listed in Table 1. The Cs, Sr and Nd normalised leach rates were low. The Na leach rate was ∼ 4 g/L thus passing the PCT-B test protocol value of 13.5 g/L for EA glass. The X-ray diffraction and scanning electron microscopy showed that BaS04 did precipitate, however all the S did not appear to have precipitated. The ANSI/ANS-16.1-2003 test was carried out on the above geopolymer composition for 5 days. The ANSI Leachability Index D (diffusivity of 10''cm sec'') for the elements released are listed in Table 2. A Portland cement was also tested for comparison and the Leachability index values are 11, 8 and 10 for Al, Na and Ca respectively. Both passed the test protocol insofar as they were > 6. Geopolymers thus passing the tests for high level nuclear waste glass (PCT-B) and for low level nuclear waste (ANSI) show promising potential

  20. A study on hardness behavior of geopolymer paste in different condition

    Science.gov (United States)

    Zainal, Farah Farhana; Hussin, Kamarudin; Rahmat, Azmi; Abdullah, Mohd Mustafa Al Bakri; Shamsudin, Shaiful Rizam

    2016-07-01

    This study has been conducted to understand the hardness behavior of geopolymer paste in different conditions; with and without being immersed in water. Geopolymer paste has been used nowadays as an alternative way to reduce global warming pollution by carbon dioxide (CO2) released to the air caused from the production of Ordinary Portland Cement (OPC). Geopolymer has many advantages such as high compressive strength, lower water absorption and lower porosity. Geopolymer paste in this study was made from a mixture of fly ash and alkaline activators. The alkaline activators that have been used were sodium hydroxide (NaOH) solution and sodium silicate (Na2SiO3) solution. Then the mixture was allowed to harden for 24hrs at ambient temperature and then placed in the oven for 24hrs with 60°C for the curing process. The hardness testing was conducted after a few months when the samples already achieved the optimum design. The samples were divided to two conditions; without immersion which was placed at ambient temperature (S1) and immersed in water for one week (S2). The samples then are divided into two at the center and testing was conducted into 4 parts which are part 1, part 2, part 3 and part 4. Various methods of non-destructively testing concrete and mortar have been in use for many years such as Vickers hardness test, Rockwell hardness test, Brinell hardness test and many more. The Rockwell hardness test method as defined in ASTM E-18 is the most commonly used hardness test method which is also used in this study. From the results, S1 has higher hardness value than S2 for all parts with the maximum value of S1 is 118.6 and the minimum value is 71.8. The maximum value of S2 is 114.4 and the minimum value is 0. The central part of the geopolymer paste also showed greater hardness values than the edge area of the samples.

  1. Waste Receiving and Processing (WRAP) facility engineering study

    International Nuclear Information System (INIS)

    Christie, M.A.; Cammann, J.W.; McBeath, R.S.; Rode, H.H.

    1985-01-01

    A new Hanford waste management facility, the Waste Receiving and Processing (WRAP) facility (planned to be operational by FY 1994) will receive, inspect, process, and repackage contact-handled transuranic (CH-TRU) contaminated solid wastes. The wastes will be certified according to the waste acceptance criteria for disposal at the Waste Isolation Pilot Plant (WIPP) geologic repository in southeast New Mexico. Three alternatives which could cost effectively be applied to certify Hanford CH-TRU waste to the WIPP Waste Acceptance Criteria (WIPP-WAC) have been examined in this updated engineering study. The alternatives differed primarily in the reference processing systems used to transform nonconforming waste into an acceptable, certified waste form. It is recommended to include the alternative of shredding and immobilizing nonconforming wastes in cement (shred/grout processing) in the WRAP facility. Preliminary capital costs for WRAP in mid-point-of-construction (FY 1991) dollars were estimated at $45 million for new construction and $37 million for modification and installation in an existing Hanford surplus facility (231-Z Building). Operating, shipping, and decommissioning costs in FY 1986 dollars were estimated at $126 million, based on a 23-y WRAP life cycle (1994 to 2017). During this period, the WRAP facility will receive an estimated 38,000 m 3 (1.3 million ft 3 ) of solid CH-TRU waste. The study recommends pilot-scale testing and evaluation of the processing systems planned for WRAP and advises further investigation of the 231-Z Building as an alternative to new facility construction

  2. Selected durability studies of geopolymer concrete with respect to carbonation, elevated temperature, and microbial induced corrosion

    Science.gov (United States)

    Badar, Mohammad Sufian

    This thesis reports a comprehensive study related to the experimental evaluation of carbonation in reinforced geopolymer concrete, the evaluation of geopolymer concretes at elevated temperature, and the resistance of geopolymer concrete to microbial induced corrosion (MIC). Carbonation: Reinforced concretes, made of geopolymer, prepared from two class F fly ashes and one class C fly ash, were subjected to accelerated carbonation treatment for a period of 450 days. Electrochemical, microstructure and pore structure examinations were performed to evaluate the effect of corrosion caused due to carbonation. GPC specimens prepared from class F fly ash exhibited lower corrosion rates by a factor of 21, and higher pH values (pH>12) when compared with concrete specimens prepared from class C Fly ash (GPCMN). Microstructure and pore characterization of GPC prepared using class F fly ash revealed lower porosity by a factor of 2.5 as compared with thier counterparts made using GPC-MN. The superior performace of GPC prepared with the class F fly ash could be attributed to the dense pore structure and formation of the protective layer of calcium and sodium alumino silicate hydrates (C/N-A-S-H) geopolymeric gels around the steel reinforcement. Elevated Temperature: Geopolymers are an emerging class of cementitious binders which possess a potential for high temperature resistance that could possibly be utilized in applications such as nozzles, aspirators and refractory linings. This study reports on the results of an investigation into the performance of a fly ash based geopolymer binder in high temperature environments. Geopolymer concrete (GPC) was prepared using eleven types of fly ashes obtained from four countries. High content alumina and silica sand was used in the mix for preparing GPC. GPC was subjected to thermal shock tests following ASTM C 1100-88. The GPC samples prepared with tabular alumina were kept at 1093° C and immediately quenched in water. GPC specimens

  3. Leachability of heavy metals in geopolymer-based materials synthesized from red mud and rice husk ash

    Science.gov (United States)

    Nguyen, Hoc Thang; Pham, Vo Thi Ha Quyen; Dang, Thanh Phong; Dao, Thanh Khe

    2018-04-01

    Red mud is an industrial waste generated during aluminum production from bauxite whereas rice husk ash is an agricultural waste from burning of rice husk that could cause negative impact on the environment if not properly managed. This study demonstrates the utilization of red mud in combination with rice husk ash to form a geopolymer-based material which can be used as bricks or replacement for traditional cement materials. The focus of this study is on the leachability of heavy metals in the raw materials and the geopolymer as this would be significant in assessing the environmental impact of the product. Leachability of metals such as Cu, Zn, Cd, Pb, Fe, and Cr was evaluated based on European (EN 124572-2 EU CEN TC292/ CEN TC 308) standard with pH value 7. Results indicate that the leachability of these metals in the geopolymer matrix is lower than that of the raw materials.

  4. The Effect of Alkaline Activator Ratio on the Compressive Strength of Fly Ash-Based Geopolymer Paste

    Science.gov (United States)

    Lăzărescu, A. V.; Szilagyi, H.; Baeră, C.; Ioani, A.

    2017-06-01

    Alkaline activation of fly ash is a particular procedure in which ash resulting from a power plant combined with a specific alkaline activator creates a solid material when dried at a certain temperature. In order to obtain desirable compressive strengths, the mix design of fly ash based geopolymer pastes should be explored comprehensively. To determine the preliminary compressive strength for fly ash based geopolymer paste using Romanian material source, various ratios of Na2SiO3 solution/ NaOH solution were produced, keeping the fly ash/alkaline activator ratio constant. All the mixes were then cured at 70 °C for 24 hours and tested at 2 and 7 days, respectively. The aim of this paper is to present the preliminary compressive strength results for producing fly ash based geopolymer paste using Romanian material sources, the effect of alkaline activators ratio on the compressive strength and studying the directions for future research.

  5. Effect of mixing geopolymer and peat on bearing capacity in Ogan Komering Ilir (OKI) by California bearing ratio (CBR) test

    Science.gov (United States)

    Raharja, Danang S.; Hadiwardoyo, Sigit P.; Rahayu, Wiwik; Zain, Nasuhi

    2017-06-01

    Geopolymer is binder material that consists of solid material and the activator solution. Geopolymer material has successfully replaced cement in the manufacture of concrete with aluminosilicate bonding system. Geopolymer concrete has properties similar to cement concrete with high compressive strength, low shrinkage value, relatively low creep value, as well as acid-resistant. Based on these, the addition of polymers in peat soils is expected to improve the bearing capacity of peat soils. A study on the influence of geopolymer addition in peat soils was done by comparing before and after the peat soil was mixed with geopolymer using CBR (California Bearing Ratio) test in unsoaked and soaked conditions. 10% mixture content of the peat dry was used, weighted with a variety of curing time 4 hours, 5 days, and 10 days. There were two methods of mixing: first, peat was mixed with fly ash geopolymer activators and mixed solution (waterglass, NaOH, water), and second, peat was mixed with fly ash and mixed geopolymer (waterglass, NaOH, water, fly ash). Changes were observed in specific gravity, dry density, acidity (pH), and the microscopic structure with Scanning Electron Microscope (SEM). Curing time did not significantly affect the CBR value. It even shows a tendency to decline with longer curing time. The first type mixture obtained CBR value of: 5.4% for 4 hours curing, 4.6% for 5 days curing and 3.6% for 10 days curing. The second type mixture obtained CBR value of: 6.1% for 4 hours curing, 5.2% for 5 days curing and 5.2% for 10 days curing. Furthermore, the specific gravity value, dry density, pH near neutral and swelling percentage increased. From both variants, the second type mixture shows better results than the first type mixture. The results of SEM (Scanning Electron Microscopy) show the structure of the peat which became denser with the fly ash particles filling the peat microporous. Also, the reaction of fly ash with geopolymer is indicated by the solid

  6. Fabrication details for wire wrapped fuel assembly components

    International Nuclear Information System (INIS)

    Bosy, B.J.

    1978-09-01

    Extensive hydraulic testing of simulated LMFBR blanket and fuel assemblies is being carried out under this MIT program. The fabrication of these test assemblies has involved development of manufacturing procedures involving the wire wrapped pins and the flow housing. The procedures are described in detail in the report

  7. Waste Receiving and Processing (WRAP) Module 1 Hazards Assessment

    International Nuclear Information System (INIS)

    CAMPBELL, L.R.

    1999-01-01

    This document establishes the technical basis in support of Emergency Planning activities for the WRAP Module 1 Facility on the Hanford Site. Through this document, the technical basis for the development of facility specific Emergency Action Levels and Emergency Planning Zone is demonstrated

  8. Implementation plan for WRAP Module 1 operational readiness review

    International Nuclear Information System (INIS)

    Irons, L.G.

    1994-01-01

    The Waste Receiving and Processing Module 1 (WRAP 1) will be used to receive, sample, treat, and ship contact-handled (CH) transuranic (TRU), low-level waste (LLW), and low-level mixed waste (LLMW) to storage and disposal sites both on the Hanford site and off-site. The primary mission of WRAP 1 is to characterize and certify CH waste in 55-gallon and 85-gallon drums; and its secondary function is to certify CH waste standard waste boxes (SWB) and boxes of similar size for disposal. The WRAP 1 will provide the capability for examination (including x-ray, visual, and contents sampling), limited treatment, repackaging, and certification of CH suspect-TRU waste in 55-gallon drums retrieved from storage, as well as newly generated CH LLW and CH TRU waste drums. The WRAP 1 will also provide examination (X-ray and visual only) and certification of CH LLW and CH TRU waste in small boxes. The decision to perform an Operational Readiness Review (ORR) was made in accordance with WHC-CM-5-34, Solid Waste Disposal Operations Administration, Section 1.4, Operational Readiness Activities. The ORR will ensure plant and equipment readiness, management and personnel readiness, and management programs readiness for the initial startup of the facility. This implementation plan is provided for defining the conduct of the WHC ORR

  9. Waste Receiving and Processing (WRAP) Module 1 Hazards Assessment

    Energy Technology Data Exchange (ETDEWEB)

    CAMPBELL, L.R.

    1999-09-29

    This document establishes the technical basis in support of Emergency Planning activities for the WRAP Module 1 Facility on the Hanford Site. Through this document, the technical basis for the development of facility specific Emergency Action Levels and Emergency Planning Zone is demonstrated.

  10. Operational readiness review phase-1 final report for WRAP-1

    Energy Technology Data Exchange (ETDEWEB)

    Bowen, W., Westinghouse Hanford

    1996-12-27

    This report documents the Operational Readiness Review for WRAP-1 Phase-1 operations. The report includes all criteria, lines of inquiry with resulting Findings and Observations. The review included assessing operational capability of the organization and the computer controlled process and facility systems.

  11. ROOM TEMPERATURE BULK SYNTHESIS OF SILVER NANOCABLES WRAPPED WITH POLYPYRROLE

    Science.gov (United States)

    Wet chemical synthesis of silver cables wrapped with polypyrrole is reported in aqueous media without use of any surfactant/capping agent and/or template. The method employs direct polymerization of pyrrole of an aqueous solution with AgNO3 as an oxidizing agent. The four probe c...

  12. DMS test summary report for the WRAP facility

    Energy Technology Data Exchange (ETDEWEB)

    Weidert, J.R.

    1997-11-04

    This report documents the functional and integration testing process performed to verify functionality of the Release 1.1, Release 2.0, Release 3.0 and Release 3.1 software for the Waste Receiving and Processing Facility (WRAP) Data Management Systems (DMS) Release 2.

  13. DMS test summary report for the WRAP facility

    International Nuclear Information System (INIS)

    Weidert, J.R.

    1997-01-01

    This report documents the functional and integration testing process performed to verify functionality of the Release 1.1, Release 2.0, Release 3.0 and Release 3.1 software for the Waste Receiving and Processing Facility (WRAP) Data Management Systems (DMS) Release 2

  14. Small Column Ion Exchange

    International Nuclear Information System (INIS)

    Huff, Thomas

    2010-01-01

    Small Column Ion Exchange (SCIX) leverages a suite of technologies developed by DOE across the complex to achieve lifecycle savings. Technologies are applicable to multiple sites. Early testing supported multiple sites. Balance of SRS SCIX testing supports SRS deployment. A forma Systems Engineering Evaluation (SEE) was performed and selected Small Column Ion Exchange columns containing Crystalline Silicotitanate (CST) in a 2-column lead/lag configuration. SEE considered use of Spherical Resorcinol-Formaldehyde (sRF). Advantages of approach at SRS include: (1) no new buildings, (2) low volume of Cs waste in solid form compared to aqueous strip effluent; and availability of downstream processing facilities for immediate processing of spent resin.

  15. Thermal-hydraulic analysis for wire-wrapped PWR cores

    Energy Technology Data Exchange (ETDEWEB)

    Diller, P. [General Electric Company, 3901 Castle Hayne Rd., Wilmington, NC 28401 (United States)], E-mail: pdiller@gmail.com; Todreas, N. [Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)], E-mail: todreas@mit.edu; Hejzlar, P. [Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2009-08-15

    This work focuses on the steady-state and transient thermal-hydraulic analyses for PWR cores using wire wraps in a hexagonal array with either U (45% w/o)-ZrH{sub 1.6} (referred to as U-ZrH{sub 1.6}) or UO{sub 2} fuels. Equivalences (thermal-hydraulic and neutronic) were created between grid spacer and wire wrap designs, and were used to apply results calculated for grid spacers to wire wrap designs. Design limits were placed on the pressure drop, critical heat flux (CHF), fuel and cladding temperature and vibrations. The vibrations limits were imposed for flow-induced vibrations (FIV) and thermal-hydraulic vibrations (THV). The transient analysis examined an overpower accident, loss of coolant accident (LOCA) and loss of flow accident (LOFA). The thermal-hydraulic performance of U-ZrH{sub 1.6} and UO{sub 2} were found very similar. Relative to grid spacer designs, wire wrap designs were found to have smaller fretting wear, substantially lower pressure drop and higher CHF. As a result, wire wrap cores were found to offer substantially higher maximum powers than grid spacer cores, allowing for a 25% power increase relative to the grid spacer uprate [Shuffler, C.A., Malen, J.A., Trant, J.M., Todreas, N.E., 2009a. Thermal-hydraulic analysis for grid supported and inverted fueled PWR cores. Nuclear Technology (this special issue devoted to hydride fuel in LWRs)] and a 58% power increase relative to the reference core.

  16. Review: Potential Strength of Fly Ash-Based Geopolymer Paste with Substitution of Local Waste Materials with High-Temperature Effect

    Science.gov (United States)

    Subekti, S.; Bayuaji, R.; Darmawan, M. S.; Husin, N. A.; Wibowo, B.; Anugraha, B.; Irawan, S.; Dibiantara, D.

    2017-11-01

    This research provided an overview of the potential fly ash based geopolymer paste for application in building construction. Geopolymer paste with various variations of fly ash substitution with local waste material and high-temperature influence exploited with the fresh and hardened condition. The local waste material which utilized for this study were sandblasting waste, carbide waste, shell powder, bagasse ash, rice husk and bottom ash. The findings of this study indicated that fly-based geopolymer paste with local waste material substitution which had high-temperature influence ash showed a similar nature of OPC binders potentially used in civil engineering applications.

  17. Total Measurement Uncertainty (TMU) for Nondestructive Assay of Transuranic (TRU) Waste at the WRAP Facility

    International Nuclear Information System (INIS)

    WILLS, C.E.

    1999-01-01

    This report examines the contributing factors to NDA measurement uncertainty at WRAP. The significance of each factor on the TMU is analyzed, and a final method is given for determining the TMU for NDA measurements at WRAP. As more data becomes available, and WRAP gains in operational experience, this report will be reviewed semi-annually and updated as necessary

  18. Mineral assemblage transformation of a metakaolin-based waste form after geopolymer encapsulation

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Benjamin D., E-mail: Benjamin.Williams@pnnl.gov [Pacific Northwest National Laboratory, PO Box 999, MSIN P7-54, Richland, WA 99352 (United States); Neeway, James J., E-mail: James.Neeway@pnnl.gov [Pacific Northwest National Laboratory, PO Box 999, MSIN P7-54, Richland, WA 99352 (United States); Snyder, Michelle M.V., E-mail: Michelle.ValentaSnyder@pnnl.gov [Pacific Northwest National Laboratory, PO Box 999, MSIN P7-54, Richland, WA 99352 (United States); Bowden, Mark E., E-mail: Mark.Bowden@pnnl.gov [Pacific Northwest National Laboratory, PO Box 999, MSIN P7-54, Richland, WA 99352 (United States); Amonette, James E., E-mail: Jim.Amonette@pnnl.gov [Pacific Northwest National Laboratory, PO Box 999, MSIN P7-54, Richland, WA 99352 (United States); Arey, Bruce W., E-mail: Bruce.Arey@pnnl.gov [Pacific Northwest National Laboratory, PO Box 999, MSIN P7-54, Richland, WA 99352 (United States); Pierce, Eric M., E-mail: pierceem@ornl.gov [Oak Ridge National Laboratory, PO Box 2008, MS-6035, Room 372, Oak Ridge, TN 37831 (United States); Brown, Christopher F., E-mail: Christopher.Brown@pnnl.gov [Pacific Northwest National Laboratory, PO Box 999, MSIN P7-54, Richland, WA 99352 (United States); Qafoku, Nikolla P., E-mail: Nik.Qafoku@pnnl.gov [Pacific Northwest National Laboratory, PO Box 999, MSIN P7-54, Richland, WA 99352 (United States)

    2016-05-15

    Mitigation of hazardous and radioactive waste can be improved through conversion of existing waste to a more chemically stable and physically robust waste form. One option for waste conversion is the fluidized bed steam reforming (FBSR) process. The resulting FBSR granular material was encapsulated in a geopolymer matrix referred to here as Geo-7. This provides mechanical strength for ease in transport and disposal. However, it is necessary to understand the phase assemblage evolution as a result of geopolymer encapsulation. In this study, we examine the mineral assemblages formed during the synthesis of the multiphase ceramic waste form. The FBSR granular samples were created from waste simulant that was chemically adjusted to resemble Hanford tank waste. Another set of samples was created using Savannah River Site Tank 50 waste simulant in order to mimic a blend of waste collected from 68 Hanford tank. Waste form performance tests were conducted using the product consistency test (PCT), the Toxicity Characteristic Leaching Procedure (TCLP), and the single-pass flow-through (SPFT) test. X-ray diffraction analyses revealed the structure of a previously unreported NAS phase and indicate that monolith creation may lead to a reduction in crystallinity as compared to the primary FBSR granular product. - Highlights: • Simulated Hanford waste was treated by the Fluidized Bed Steam Reformer (FBSR) process. • The FBSR granular product was encapsulated in a geopolymer monolith. • Leach tests were performed to examine waste form performance. • XRD revealed the structure of a previously unreported sodium aluminosilicate phase. • Monolithing of granular waste forms may lead to a reduction in crystallinity.

  19. JCE Feature Columns

    Science.gov (United States)

    Holmes, Jon L.

    1999-05-01

    The Features area of JCE Online is now readily accessible through a single click from our home page. In the Features area each column is linked to its own home page. These column home pages also have links to them from the online Journal Table of Contents pages or from any article published as part of that feature column. Using these links you can easily find abstracts of additional articles that are related by topic. Of course, JCE Online+ subscribers are then just one click away from the entire article. Finding related articles is easy because each feature column "site" contains links to the online abstracts of all the articles that have appeared in the column. In addition, you can find the mission statement for the column and the email link to the column editor that I mentioned above. At the discretion of its editor, a feature column site may contain additional resources. As an example, the Chemical Information Instructor column edited by Arleen Somerville will have a periodically updated bibliography of resources for teaching and using chemical information. Due to the increase in the number of these resources available on the WWW, it only makes sense to publish this information online so that you can get to these resources with a simple click of the mouse. We expect that there will soon be additional information and resources at several other feature column sites. Following in the footsteps of the Chemical Information Instructor, up-to-date bibliographies and links to related online resources can be made available. We hope to extend the online component of our feature columns with moderated online discussion forums. If you have a suggestion for an online resource you would like to see included, let the feature editor or JCE Online (jceonline@chem.wisc.edu) know about it. JCE Internet Features JCE Internet also has several feature columns: Chemical Education Resource Shelf, Conceptual Questions and Challenge Problems, Equipment Buyers Guide, Hal's Picks, Mathcad

  20. Fly ash/Kaolin based geopolymer green concretes and their mechanical properties

    Directory of Open Access Journals (Sweden)

    F.N. Okoye

    2015-12-01

    Full Text Available Geopolymer concrete mixes were cast using fly ash, kaolin, sodium hydroxide, potassium hydroxide, sodium silicate and aggregates. Portland cement concrete (M30 was used as a reference sample. The effect of silica fume, temperature (40 °C, 60 °C, 80 °C, 100 °C and 120 °C, sodium and potassium hydroxides and different superplasticizers on the compressive strength are reported [1]. Maximum strength was found at 100 °C and 14 M alkali solution [1].

  1. Characterization of geo-polymer porosity: temporal evolution and study of the confined water

    International Nuclear Information System (INIS)

    Benavent, Virginie

    2016-01-01

    In this study, we have investigated the porous network of geo-polymers. The first step consisted in characterizing the structure of the porous network by the means of both intrusive experimental techniques (water porosimetry, gas sorption and mercury intrusion) and non-intrusive techniques (small-angle X-ray and neutron scattering). By the same time, the evolutions of the porous structure as well as the mechanical properties were followed over time. The second step was to determine the structure, the thermodynamics and the dynamics of water confined in the porosity by differential scanning calorimetry, quasi-elastic neutron scattering and migration tests. Geo-polymer pore structure is a complex multi-scale porosity, a meso- and macroporous network, essentially open and connected. It consists in a vermicular meso-porous network which connects the macro-pores. The meso-pore characteristic size depends on the formulation of the geo-polymer paste and is ranged between about 4 and 10 nm. Geo-polymer have a total pore volume comprised between 40 and 50 %, the meso-porous volume represents between 7 and 15 % of the material global volume. The majority of the pore volume is then attributed to macro-pores. a slight closure of porosity was observed with time and was attributed to a dissolution-precipitation mechanism occurring at pore wall interfaces. The mechanical properties reach a maximum within 10 days, and then are stable over time when the samples were kept from drying and carbonation and at the temperature of 20 C. Besides, three kinds of water were highlighted inside the porosity: (i) an interfacial water linked at the pore surfaces, (ii) free water inside the meso-pores and (iii) free water inside macro-pores. at local time scale, the mobility of water was found close to the one of free water, and at the macroscopic scale, a decrease in diffusion coefficient of one order of magnitude was observed, together with an effect of meso-pore size. (author) [fr

  2. Application of a clay-slag geopolymer matrix for repairing damaged concrete: Laboratory and industrial-scale experiments

    Czech Academy of Sciences Publication Activity Database

    Perná, Ivana; Hanzlíček, Tomáš; Boura, P.; Lučaník, A.

    2017-01-01

    Roč. 59, č. 10 (2017), s. 929-937 ISSN 0025-5300 Institutional support: RVO:67985891 Keywords : blast-furnace slag * geopolymer * scanning electron microscopy (SEM) * damaged concrete repair * long-term monitoring Subject RIV: JJ - Other Materials OBOR OECD: Composites (including laminates, reinforced plastics, cermets, combined natural and synthetic fibre fabrics Impact factor: 0.418, year: 2016

  3. Red-clay ceramic powders as geopolymer precursors: Consideration of amorphous portion and CaO content

    Czech Academy of Sciences Publication Activity Database

    Keppert, M.; Vejmelková, E.; Bezdička, Petr; Doleželová, M.; Čáchová, M.; Scheinherrová, L.; Pokorný, J.; Vyšvařil, M.; Rovnaníková, P.; Černý, R.

    2018-01-01

    Roč. 161, SEP (2018), s. 82-89 ISSN 0169-1317 Institutional support: RVO:61388980 Keywords : Amorphous content * Calcium oxide * Composition * Geopolymers * Red-clay ceramics Subject RIV: CA - Inorganic Chemistry OBOR OECD: Inorganic and nuclear chemistry Impact factor: 3.101, year: 2016

  4. Influence of activating solution and the addition of NaF on metakaolin-based geopolymer physico-chemical properties

    International Nuclear Information System (INIS)

    Agullo, J.; Muzeau, B.; Trepy, N.; L'Hostis, V.; Lambertin, D.

    2015-01-01

    The technology of geo-polymerisation is attracting a lot of interest due to the wide variety of potential applications. Recently emerging and alternative cementitious systems based on geo-polymers have been reported in literature. Geo-polymer materials have been proposed as new binders for safe radioactive waste containment. Moreover, their good fluidity and fire resistance make them compatible with industrial processes for embedding wastes. The purpose of this work was to investigate the physico-chemical properties of meta-kaolin-based geo-polymer which could be used as mineral binder for encapsulation of metallic nuclear wastes. To improve the knowledge of this binder, its microstructure and its interstitial solution have been characterized during hydration (up to 28 days). Interstitial solutions were extracted at different hydration time and subsequent analyses allow us to determine their chemical composition. pH measurements confirm the high alkalinity of the interstitial pore solution. The influence of the activating solution (NaOH or KOH) and the addition of NaF as corrosion inhibitor in the geo-polymer composition were also studied. The nature of different crystalline phases was identified by X-ray diffraction. Water accessible porosity for these materials was estimated around 59%. The pore size distribution was determined by mercury intrusion porosity. Alkaline cations have proved to induce changes in the pore size distribution, these ones coming from whether the activating solution or the NaF addition. (authors)

  5. Effects of fiber length on mechanical properties and fracture behavior of short carbon fiber reinforced geopolymer matrix composites

    International Nuclear Information System (INIS)

    Lin Tiesong; Jia Dechang; He Peigang; Wang Meirong; Liang Defu

    2008-01-01

    A kind of sheet-like carbon fiber preform was developed using short fibers (2, 7 and 12 mm, respectively) as starting materials and used to strengthen a geopolymer. Mechanical properties, fracture behavior, microstructure and toughening mechanisms of the as-prepared composites were investigated by three-point bending test, optical microscope and scanning electron microscopy. The results show that the short carbon fibers disperse uniformly in geopolymer matrix. The C f /geopolymer composites exhibit apparently improved mechanical properties and an obvious noncatastrophic failure behavior. The composite reinforced by the carbon fibers of 7 mm in length shows a maximum flexural strength as well as the highest work of facture, which are nearly 5 times and more than 2 orders higher than that of the geopolymer matrix, respectively. The predominant strengthening and toughening mechanisms are attributed to the apparent fiber bridging and pulling-out effect based on the weak fiber/matrix interface as well as the sheet-like carbon fiber preform

  6. Impact of Blending on Strength Distribution of Ambient Cured Metakaolin and Palm Oil Fuel Ash Based Geopolymer Mortar

    Directory of Open Access Journals (Sweden)

    Taliat Ola Yusuf

    2014-01-01

    Full Text Available This paper investigates the influence of blending of metakaolin with silica rich palm oil fuel ash (POFA on the strength distribution of geopolymer mortar. The broadness of strength distribution of quasi-brittle to brittle materials depends strongly on the existence of flaws such as voids, microcracks, and impurities in the material. Blending of materials containing alumina and silica with the objective of improving the performance of geopolymer makes comprehensive characterization necessary. The Weibull distribution is used to study the strength distribution and the reliability of geopolymer mortar specimens prepared from 100% metakaolin, 50% and 70% palm and cured under ambient condition. Mortar prisms and cubes were used to test the materials in flexure and compression, respectively, at 28 days and the results were analyzed using Weibull distribution. In flexure, Weibull modulus increased with POFA replacement, indicating reduced broadness of strength distribution from an increased homogeneity of the material. Modulus, however, decreased with increase in replacement of POFA in the specimens tested under compression. It is concluded that Weibull distribution is suitable for analyses of the blended geopolymer system. While porous microstructure is mainly responsible for flexural failure, heterogeneity of reaction relics is responsible for the compression failure.

  7. The Effect of Sodium Hydroxide Molarity on Strength Development of Non-Cement Class C Fly Ash Geopolymer Mortar

    Science.gov (United States)

    Wardhono, A.

    2018-01-01

    The use of fly ash as cement replacement material can overcome the environmental issues, especially the global warming problem caused by the greenhouse effect. This is attributed to the CO2 gas produced during the cement manufacturing process, which 1 ton of cement is equivalent to 1 ton CO2. However, the major problem of fly ash is the requirement of activators to activate the polymer reactions. The most common activator used in non-cement or geopolymer material is the combination of sodium hydroxide (NaOH) and sodium silicate. This study aims to identify the effect of NaOH molarity as activator on strength development of non-cement class C fly ash geopolymer mortar. The molarity variations of NaOH were 6 Molar (M), 8M, 10M, 12M, 14M and 15M. The compressive strength test was performed at the age of 3, 7 and 28 days in accordance with ASTM standard, and the specimens were cured at room temperature. The results show that the highest compressive strength was achieved by geopolymer mortar with a molarity of 12M. It exhibits a higher strength to that normal mortar at 28 days. However, the use of NaOH molarity more than 12M tends to decrease the strength of non-cement geopolymer mortar specimens.

  8. The effect of heat treatment on the mechanical and structural properties of one-part geopolymer-zeolite composites

    NARCIS (Netherlands)

    Sturm, P.; Gluth, G.J.G.; Simon, S.; Brouwers, H.J.H.; Kühne, H.C.

    2016-01-01

    This contribution presents the results of structural and compressive strength investigations on cured and high-temperature treated silica-based one-part geopolymer-zeolite composites. The specimens were synthesized from two different silica sources, sodium aluminate and water. The phase content as

  9. Distillation Column Flooding Predictor

    Energy Technology Data Exchange (ETDEWEB)

    George E. Dzyacky

    2010-11-23

    The Flooding Predictor™ is a patented advanced control technology proven in research at the Separations Research Program, University of Texas at Austin, to increase distillation column throughput by over 6%, while also increasing energy efficiency by 10%. The research was conducted under a U. S. Department of Energy Cooperative Agreement awarded to George Dzyacky of 2ndpoint, LLC. The Flooding Predictor™ works by detecting the incipient flood point and controlling the column closer to its actual hydraulic limit than historical practices have allowed. Further, the technology uses existing column instrumentation, meaning no additional refining infrastructure is required. Refiners often push distillation columns to maximize throughput, improve separation, or simply to achieve day-to-day optimization. Attempting to achieve such operating objectives is a tricky undertaking that can result in flooding. Operators and advanced control strategies alike rely on the conventional use of delta-pressure instrumentation to approximate the column’s approach to flood. But column delta-pressure is more an inference of the column’s approach to flood than it is an actual measurement of it. As a consequence, delta pressure limits are established conservatively in order to operate in a regime where the column is never expected to flood. As a result, there is much “left on the table” when operating in such a regime, i.e. the capacity difference between controlling the column to an upper delta-pressure limit and controlling it to the actual hydraulic limit. The Flooding Predictor™, an innovative pattern recognition technology, controls columns at their actual hydraulic limit, which research shows leads to a throughput increase of over 6%. Controlling closer to the hydraulic limit also permits operation in a sweet spot of increased energy-efficiency. In this region of increased column loading, the Flooding Predictor is able to exploit the benefits of higher liquid

  10. Nuclear reactor control column

    International Nuclear Information System (INIS)

    Bachovchin, D.M.

    1982-01-01

    The nuclear reactor control column comprises a column disposed within the nuclear reactor core having a variable cross-section hollow channel and containing balls whose vertical location is determined by the flow of the reactor coolant through the column. The control column is divided into three basic sections wherein each of the sections has a different cross-sectional area. The uppermost section of the control column has the greatest crosssectional area, the intermediate section of the control column has the smallest cross-sectional area, and the lowermost section of the control column has the intermediate cross-sectional area. In this manner, the area of the uppermost section can be established such that when the reactor coolant is flowing under normal conditions therethrough, the absorber balls will be lifted and suspended in a fluidized bed manner in the upper section. However, when the reactor coolant flow falls below a predetermined value, the absorber balls will fall through the intermediate section and into the lowermost section, thereby reducing the reactivity of the reactor core and shutting down the reactor

  11. Multiple Surrogate Modeling for Wire-Wrapped Fuel Assembly Optimization

    International Nuclear Information System (INIS)

    Raza, Wasim; Kim, Kwang-Yong

    2007-01-01

    In this work, shape optimization of seven pin wire wrapped fuel assembly has been carried out in conjunction with RANS analysis in order to evaluate the performances of surrogate models. Previously, Ahmad and Kim performed the flow and heat transfer analysis based on the three-dimensional RANS analysis. But numerical optimization has not been applied to the design of wire-wrapped fuel assembly, yet. Surrogate models are being widely used in multidisciplinary optimization. Queipo et al. reviewed various surrogates based models used in aerospace applications. Goel et al. developed weighted average surrogate model based on response surface approximation (RSA), radial basis neural network (RBNN) and Krigging (KRG) models. In addition to the three basic models, RSA, RBNN and KRG, the multiple surrogate model, PBA also has been employed. Two geometric design variables and a multi-objective function with a weighting factor have been considered for this problem

  12. Wire-wrap bundle compression-characteristics study. Phase I

    International Nuclear Information System (INIS)

    Chertock, A.J.

    1974-06-01

    An analytical computer comparison was made of the compression characteristics of proposed wire-wrap bundles. The study included analysis of 7- and 37-rod straight-start bundles (base configuration), and softened 37-rod configurations. The softened configurations analyzed were: straight-start with distributed wireless fuel rods, and the staggered wire-wrap start angles of 0 0 -30 0 -60 0 and 0 0 -45 0 -90 0 . The compression of the bundle simulates the bundle-to-channel interference at end-of-life conditions at which high differential swelling between the channel and bundle has been predicted. The computer results do not include the so-called dispersion effects. The effects of other variables such as pitch length, creep, axial variations in swelling, and degree of swelling were not studied. These analytic studies give an indication of trends only. No credence should be given to specific quantitative load or deflection results quoted in this report

  13. Improvements in solvent extraction columns

    International Nuclear Information System (INIS)

    Aughwane, K.R.

    1987-01-01

    Solvent extraction columns are used in the reprocessing of irradiated nuclear fuel. For an effective reprocessing operation a solvent extraction column is required which is capable of distributing the feed over most of the column. The patent describes improvements in solvent extractions columns which allows the feed to be distributed over an increased length of column than was previously possible. (U.K.)

  14. Lightweight Heat Resistant Geopolymer-based Materials Synthesized from Red Mud and Rice Husk Ash Using Sodium Silicate Solution as Alkaline Activator

    Directory of Open Access Journals (Sweden)

    Hoc Thang Nguyen

    2017-01-01

    Full Text Available Geopolymer is an inorganic polymer composite with potentials to replace Ordinary Portland Cement (OPC-based materials in the future because of its lower energy consumption, minimal CO2 emissions and lower production cost as it utilizes industrial waste resources. Hence, geopolymerization and the process to produce geopolymers for various applications like building materials can be considered as green industry. Moreover, in our study, the raw materials we used are red mud and rice husk ash, which are are industrial and agricultural wastes that need to be managed to reduce their impact to the environment. The red mud and rice husk ash combined with sodium silicate (water glass solution were mixed to form geopolymer materials. Moreover, the geopolymer specimens were also tested for heat resistance at a temperature of 1000°C for 2 hours. Results suggest high heat resistance with an increase of compressive strength after exposed at high temperature.

  15. Some comments on N=1 gauge theories from wrapped branes

    International Nuclear Information System (INIS)

    Apreda, R.; Bigazzi, F.; Petrini, M.; Cotrone, A.L.; Zaffaroni, A.

    2001-12-01

    We discuss various aspects of gauge theories realized on the world-volume of wrapped branes. In particular we analyze the coupling of SYM operators to space-time fields both in N=1 and N=2 models and give a description of the gluino condensate in the Maldacena-Nunez N=1 solution. We also explore the seven dimensional BPS equations relevant for these solutions and their generalizations. (author)

  16. Thermal analysis methods for LMFBR wire wrapped bundles

    International Nuclear Information System (INIS)

    Todreas, N.E.

    1976-11-01

    A note is presented which was written to stimulate an awareness and discussion of the fundamental differences in the formulation of certain existing analysis codes for LMFBR wire wrap bundles. The contention of the note is that for those array types where data exists (one wire per pin, equal start angles), the ENERGY method results for coolant temperature under forced convection conditions provide benchmarks of reliability equal to the results of codes COBRA and TH1-3D

  17. CEL Working procedures for WRAP 2A formulation development test

    International Nuclear Information System (INIS)

    Duchsherer, M.J.

    1994-01-01

    The WRAP 2A facility will encapsulate retrieved, stored, and newly generated contact-handled mixed low level waste (MLLW) into 55-500 gal cementitous forms. Standardized test procedures will be required to facilitate this process. Cementitous specimens will be prepared from simulated drum wastes and will be tested in the Chemical Engineering Laboratory using the laboratory operating/working procedures encorporated into this document

  18. Patient-specific fibre-based models of muscle wrapping

    Science.gov (United States)

    Kohout, J.; Clapworthy, G. J.; Zhao, Y.; Tao, Y.; Gonzalez-Garcia, G.; Dong, F.; Wei, H.; Kohoutová, E.

    2013-01-01

    In many biomechanical problems, the availability of a suitable model for the wrapping of muscles when undergoing movement is essential for the estimation of forces produced on and by the body during motion. This is an important factor in the Osteoporotic Virtual Physiological Human project which is investigating the likelihood of fracture for osteoporotic patients undertaking a variety of movements. The weakening of their skeletons makes them particularly vulnerable to bone fracture caused by excessive loading being placed on the bones, even in simple everyday tasks. This paper provides an overview of a novel volumetric model that describes muscle wrapping around bones and other muscles during movement, and which includes a consideration of how the orientations of the muscle fibres change during the motion. The method can calculate the form of wrapping of a muscle of medium size and visualize the outcome within tenths of seconds on commodity hardware, while conserving muscle volume. This makes the method suitable not only for educational biomedical software, but also for clinical applications used to identify weak muscles that should be strengthened during rehabilitation or to identify bone stresses in order to estimate the risk of fractures. PMID:24427519

  19. Hot fuel examination facility element spacer wire-wrap machine

    International Nuclear Information System (INIS)

    Tobias, D.A.; Sherman, E.K.

    1989-01-01

    Nondestructive examinations of irradiated experimental fuel elements conducted in the Argonne National Laboratory Hot Fuel Examination Facility/North (HFEF/N) at the Idaho National Engineering Laboratory include laser and contact profilometry (element diameter measurements), electrical eddy-current testing for cladding and thermal bond defects, bow and length measurements, neutron radiography, gamma scanning, remote visual exam, and photography. Profilometry was previously restricted to spiral profilometry of the element to prevent interference with the element spacer wire wrapped in a helix about the Experimental Breeder Reactor II (EBR-II)-type fuel element from end to end. By removing the spacer wire prior to conducting profilometry examination, axial profilometry techniques may be used, which are considerably faster than spiral techniques and often result in data acquisition more important to experiment sponsors. Because the element must often be reinserted into the nuclear reactor (EBR-II) for additional irradiation, however, the spacer wire must be reinstalled on the highly irradiated fuel element by remote means after profilometry of the wireless elements. The element spacer wire-wrap machine developed at HFEF is capable of helically wrapping fuel elements with diameters up to 1.68 cm (0.660 in.) and 2.44-m (96-in.) lengths. The machine can accommodate almost any desired wire pitch length by simply inserting a new wrapper gear module

  20. Universal critical wrapping probabilities in the canonical ensemble

    Directory of Open Access Journals (Sweden)

    Hao Hu

    2015-09-01

    Full Text Available Universal dimensionless quantities, such as Binder ratios and wrapping probabilities, play an important role in the study of critical phenomena. We study the finite-size scaling behavior of the wrapping probability for the Potts model in the random-cluster representation, under the constraint that the total number of occupied bonds is fixed, so that the canonical ensemble applies. We derive that, in the limit L→∞, the critical values of the wrapping probability are different from those of the unconstrained model, i.e. the model in the grand-canonical ensemble, but still universal, for systems with 2yt−d>0 where yt=1/ν is the thermal renormalization exponent and d is the spatial dimension. Similar modifications apply to other dimensionless quantities, such as Binder ratios. For systems with 2yt−d≤0, these quantities share same critical universal values in the two ensembles. It is also derived that new finite-size corrections are induced. These findings apply more generally to systems in the canonical ensemble, e.g. the dilute Potts model with a fixed total number of vacancies. Finally, we formulate an efficient cluster-type algorithm for the canonical ensemble, and confirm these predictions by extensive simulations.

  1. WRAP Module 1 data management system (DMS) software design description (SDD)

    Energy Technology Data Exchange (ETDEWEB)

    Talmage, P.A.

    1995-03-17

    The Waste Receiving and Processing (WRAP) Module 1 Data Management System (DMS) System Design Description (SDD) describes the logical and physical architecture of the system. The WRAP 1 DMS SDD formally partitions the elements of the system described in the WRAP 1 DMS Software requirements specification into design objects and describes the key properties and relationships among the design objects and interfaces with external systems such as the WRAP Plant Control System (PCS). The WRAP 1 DMS SDD can be thought of as a detailed blueprint for implementation activities. The design descriptions contained within this document will describe, in detail, the software products that will be developed to assist the Project W-026, Waste Receiving and Processing Module 1, in their management functions. The WRAP 1 DMS is required to collect, store, and report data related to certification, tracking, packaging, repackaging, processing, and shipment of waste processed or stored at the WRAP 1 facility.

  2. WRAP Module 1 data management system (DMS) software design description (SDD)

    International Nuclear Information System (INIS)

    Talmage, P.A.

    1995-01-01

    The Waste Receiving and Processing (WRAP) Module 1 Data Management System (DMS) System Design Description (SDD) describes the logical and physical architecture of the system. The WRAP 1 DMS SDD formally partitions the elements of the system described in the WRAP 1 DMS Software requirements specification into design objects and describes the key properties and relationships among the design objects and interfaces with external systems such as the WRAP Plant Control System (PCS). The WRAP 1 DMS SDD can be thought of as a detailed blueprint for implementation activities. The design descriptions contained within this document will describe, in detail, the software products that will be developed to assist the Project W-026, Waste Receiving and Processing Module 1, in their management functions. The WRAP 1 DMS is required to collect, store, and report data related to certification, tracking, packaging, repackaging, processing, and shipment of waste processed or stored at the WRAP 1 facility

  3. DuraLith geopolymer waste form for Hanford secondary waste: Correlating setting behavior to hydration heat evolution

    International Nuclear Information System (INIS)

    Xu, Hui; Gong, Weiliang; Syltebo, Larry; Lutze, Werner; Pegg, Ian L.

    2014-01-01

    Highlights: • Quantitative correlations firstly established for cementitious waste forms. • Quantitative correlations firstly established for geopolymeric materials. • Ternary DuraLith geopolymer waste forms for Hanford radioactive wastes. • Extended setting times which improve workability for geopolymer waste forms. • Reduced hydration heat release from DuraLith geopolymer waste forms. - Abstract: The binary furnace slag-metakaolin DuraLith geopolymer waste form, which has been considered as one of the candidate waste forms for immobilization of certain Hanford secondary wastes (HSW) from the vitrification of nuclear wastes at the Hanford Site, Washington, was extended to a ternary fly ash-furnace slag-metakaolin system to improve workability, reduce hydration heat, and evaluate high HSW waste loading. A concentrated HSW simulant, consisting of more than 20 chemicals with a sodium concentration of 5 mol/L, was employed to prepare the alkaline activating solution. Fly ash was incorporated at up to 60 wt% into the binder materials, whereas metakaolin was kept constant at 26 wt%. The fresh waste form pastes were subjected to isothermal calorimetry and setting time measurement, and the cured samples were further characterized by compressive strength and TCLP leach tests. This study has firstly established quantitative linear relationships between both initial and final setting times and hydration heat, which were never discovered in scientific literature for any cementitious waste form or geopolymeric material. The successful establishment of the correlations between setting times and hydration heat may make it possible to efficiently design and optimize cementitious waste forms and industrial wastes based geopolymers using limited testing results

  4. Buckling of liquid columns

    NARCIS (Netherlands)

    Habibi, M.; Rahmani, Y.; Bonn, D.; Ribe, N.M.

    2010-01-01

    Under appropriate conditions, a column of viscous liquid falling onto a rigid surface undergoes a buckling instability. Here we show experimentally and theoretically that liquid buckling exhibits a hitherto unsuspected complexity involving three different modes—viscous, gravitational, and

  5. Microstructural analysis of geopolymer developed from wood fly ash, post-mortem doloma refractory and metakaolin; Analise microestrutural de geopolimero desenvolvido a partir de cinza de olaria, tijolo refratario dolomitico post-mortem e metacaulim

    Energy Technology Data Exchange (ETDEWEB)

    Moura, Jailes de Santana; Mafra, Marcio Paulo de Araujo; Rabelo, Adriano Alves; Fagury, Renata Lilian Ribeiro Portugal; Fagury Neto, Elias, E-mail: jailesmoura@hotmail.com, E-mail: fagury@unifesspa.edu.br [Universidade Federal do Sul e Sudeste do Para (UNIFESSPA), PA (Brazil). Faculdade de Engenharia de Materiais

    2016-07-01

    Geopolymers are one of the widely discussed topics of materials science in recent times due to its vast potential as an alternative binder material to cement. This work aimed to evaluate the microstructure of geopolymers developed from wood fly ash, post-mortem doloma refractory and metakaolin. A preliminary study has been completed and achieved significant results compressive strength: the best formulation of geopolymer paste obtained approximately 25 MPa. Microstructural analysis by scanning electron microscopy, the geopolymer paste, allowed to verify the homogeneity, distribution of components, and providing evidence of raw materials that do not respond if there was crystalline phase, porosity and density of the structure. (author)

  6. Enhancement Experiment on Cementitious Activity of Copper-Mine Tailings in a Geopolymer System

    Directory of Open Access Journals (Sweden)

    Lin Yu

    2017-12-01

    Full Text Available Copper-mine tailings are the residual products after the extraction of precious copper metal from copper ores, and their storage can create numerous environmental problems. Many researchers have used copper-mine tailings for the preparation of geopolymers. This paper studies the enhancement of the cementitious activity of copper-mine tailings in geopolymer systems. First, copper-mine tailings are activated through mechanical grinding activation. Then, the mechanically activated copper-mine tailings are further processed through thermal activation and alkaline-roasting activation. The cementitious activity index of copper-mine tailings is characterized through the degree of leaching concentration of Si and Al. It was observed that the Si and Al leaching concentration of mechanically activated tailings was increased by 26.03% and 93.33%, respectively. The concentration of Si and Al was increased by 54.19% and 119.92%, respectively. For alkaline-roasting activation, roasting time, temperature and the mass ratio of copper-mine tailings to NaOH (C/N ratio were evaluated through orthogonal tests, and the best condition for activation was 120 min at 600 °C with a C/N ratio of 5:1. In this study, scanning electron microscopy (SEM, X-ray diffraction (XRD and infra-red (IR analysis show that mechanical, thermal and alkaline-roasting activation could be used to improve the cementitious activity index of copper-mine tailings.

  7. Porous Geopolymer Insulating Core from a Metakaolin/Biomass Ash Composite

    Directory of Open Access Journals (Sweden)

    Annalisa Natali Murri

    2017-12-01

    Full Text Available Ashes derived from the combustion of vegetal and animal biomass still represent a mostly unexplored secondary raw material for the production of alkali-activated materials, given their peculiar chemical nature. In this work, calcium phosphate biomass ashes were successfully used as partially reactive fillers in a metakaolin-based geopolymer composite to produce, by direct foaming, sustainable and lightweight boards with thermal insulating properties. The investigated materials were obtained by activating a blend of metakaolin and biomass ash in a weight ratio of 1: 1 and foamed with the addition of H2O2 in measure of 5 wt. %, to maximize the volume of disposed ash and ensure adequate properties to the material at the same time. The obtained geopolymer composite was characterized by microstructural, chemical-physical, mechanical and thermal analysis: the obtained results showed that biomass ash and metakaolin well integrated in the microstructure of the final porous material, which was characterized by a density of about 310 kg/m3 and a thermal conductivity of 0.073 W/mK at a mean test temperature of 30 °C, coupled with an acceptable compressive strength of about 0.6 MPa. Dilatometric and thermogravimetric analysis, performed up to 1000 °C, highlighted the thermal stability of the composite, which could be regarded as a promising material for low-cost, self-bearing thermal insulating partitions or lightweight cores for thermostructural sandwich panels.

  8. The Application of PVA Fiber to Improve the Mechanical Properties of Geopolymer Concrete

    Directory of Open Access Journals (Sweden)

    Manfaluthy Muhammad Lutfi

    2017-01-01

    Full Text Available This paper presents an experimental investigation on the improvement of geopolymer concrete properties through the use of polyvinyl alcohol (PVA fibers mixed in the fresh concrete. For the purpose of obtaining the optimum mechanical properties, the volume fraction of PVA fibers was varied at 0%; 0.3%; 0.5%; ad 0.8%. All mixtures were cast by mixing fly ash, alkali activator, and aggregates. The activator used in this study was a combination of sodium silicate (Na2SiO3 and sodium hydroxide (NaOH. The mechanical properties of geopolymer concrete were obtained from the results of compressive strength, splitting strength, uniaxial tensile strength, elastic modulus, and flexural strength. It is found that the variation of 0.8% PVA fibers resulted in the highest strength for overall test. The utilization of 0.8% PVA fibers also contributed to increasing the direct tensile up to 50%. However, it is noticed that the elastic modulus was more prone to decrease as the fiber content in the mixture increased.

  9. Development of Nano TiO2–Geopolymer Functional Composite as Antifouling Bricks

    Directory of Open Access Journals (Sweden)

    Kusuma Wardani Nurul

    2017-01-01

    Full Text Available The purpose of study is to examine the ability of nano TiO2 – geopolymer functional composite as antifouling bricks. The samples were synthesized through alkali-activation method at 70°C for 1 hour by mixing metaclay with TiO2 nanoparticles and activated with sodium silicate solution. There were two series of samples produced, namely, GT_A with addition of 2% nanoTiO2 and GT_B with addition of 4% nano TiO2 relative to the mass of metaclay. The samples were immersed in water and in 1M H2SO4 solution for 4 days to examine the resistance of composites in hars environment. The x-ray diffraction (XRD was performed to examine the chemical compositions of the samples before and after environmental test. The morphology of the samples surfaces was examined by using Scanning Electron Microscopy (SEM coupled with energy dispersive spectroscopy (EDS. Based on this study, sample GT_A shows its excellent properties as antifouling bricks. The addition of nano TiO2 was found to improve the quality of geopolymers as a high performance bricks.

  10. Solvent extraction columns

    International Nuclear Information System (INIS)

    Middleton, P.; Smith, J.R.

    1979-01-01

    In pulsed columns for use in solvent extraction processes, e.g. the reprocessing of nuclear fuel, the horizontal perforated plates inside the column are separated by interplate spacers manufactured from metallic neutron absorbing material. The spacer may be in the form of a spiral or concentric circles separated by radial limbs, or may be of egg-box construction. Suitable neutron absorbing materials include stainless steel containing boron or gadolinium, hafnium metal or alloys of hafnium. (UK)

  11. Effect of Diagonal Belt to the Moment Capacity of the Precast Beam-Column Joint using CFRP Sheet

    OpenAIRE

    Djamaluddin, Rudy

    2017-01-01

    The FRP sheet has been applied in many fields of civil engineering structures. The study on the application has been spread out involving of precast concrete structures, such as the application on the connection of beam and column of precast concrete structures. Since the strength of the CFRP sheet is depend on the bonding capacity, it is necessary to apply a vertical U-wrap belt on the main sheet to increase its bonding strength. However, it was reported that the vertical U-wrap belt may cau...

  12. An Experimental Study on Hybrid Noncompression CF Bracing and GF Sheet Wrapping Reinforcement Method to Restore Damaged RC Structures

    Directory of Open Access Journals (Sweden)

    Kang Seok Lee

    2015-01-01

    Full Text Available We describe a novel technique for restoration of reinforced concrete (RC structures that have sustained damage during an earthquake. The reinforcement scheme described here is a hybrid seismic retrofitting technique that combines noncompression X-bracing using CF with externally bonded GF sheets to strengthen RC structures that have sustained damage following an earthquake. The GF sheet is used to improve the ductility of columns, and the noncompression CF X-bracing system, which consists of CF bracing and anchors to replace the conventional steel bracing and bolt connections, is used to increase the lateral strength of the framing system. We report seismic restoration capacity, which enables reuse of the damaged RC frames via the hybrid CF X-bracing and GF sheet wrapping system. Cyclic loading tests were carried out to investigate hysteresis of the lateral load-drift relations, as well as the ductility. The GF sheet significantly improved the ductility of columns, resulting in a change in failure mode. The strengthening effect of conventional CF sheets used in columns is not sufficient with respect to lateral strength and stiffness. However, this study results in a significant increase in the strength of the structure due to the use of CF X-bracing and inhibited buckling failure of the bracing. This result can be exploited to develop guidelines for the application of the reinforcement system to restore damaged RC structures.

  13. Assembly for connecting the column ends of two capillary columns

    International Nuclear Information System (INIS)

    Kolb, B.; Auer, M.; Pospisil, P.

    1984-01-01

    In gas chromatography, the column ends of two capillary columns are inserted into a straight capillary from both sides forming annular gaps. The capillary is located in a tee out of which the capillary columns are sealingly guided, and to which carrier gas is supplied by means of a flushing flow conduit. A ''straight-forward operation'' having capillary columns connected in series and a ''flush-back operation'' are possible. The dead volume between the capillary columns can be kept small

  14. WRAP Module 1 sampling strategy and waste characterization alternatives study

    Energy Technology Data Exchange (ETDEWEB)

    Bergeson, C.L.

    1994-09-30

    The Waste Receiving and Processing Module 1 Facility is designed to examine, process, certify, and ship drums and boxes of solid wastes that have a surface dose equivalent of less than 200 mrem/h. These wastes will include low-level and transuranic wastes that are retrievably stored in the 200 Area burial grounds and facilities in addition to newly generated wastes. Certification of retrievably stored wastes processing in WRAP 1 is required to meet the waste acceptance criteria for onsite treatment and disposal of low-level waste and mixed low-level waste and the Waste Isolation Pilot Plant Waste Acceptance Criteria for the disposal of TRU waste. In addition, these wastes will need to be certified for packaging in TRUPACT-II shipping containers. Characterization of the retrievably stored waste is needed to support the certification process. Characterization data will be obtained from historical records, process knowledge, nondestructive examination nondestructive assay, visual inspection of the waste, head-gas sampling, and analysis of samples taken from the waste containers. Sample characterization refers to the method or methods that are used to test waste samples for specific analytes. The focus of this study is the sample characterization needed to accurately identify the hazardous and radioactive constituents present in the retrieved wastes that will be processed in WRAP 1. In addition, some sampling and characterization will be required to support NDA calculations and to provide an over-check for the characterization of newly generated wastes. This study results in the baseline definition of WRAP 1 sampling and analysis requirements and identifies alternative methods to meet these requirements in an efficient and economical manner.

  15. WRAP Module 1 sampling strategy and waste characterization alternatives study

    International Nuclear Information System (INIS)

    Bergeson, C.L.

    1994-01-01

    The Waste Receiving and Processing Module 1 Facility is designed to examine, process, certify, and ship drums and boxes of solid wastes that have a surface dose equivalent of less than 200 mrem/h. These wastes will include low-level and transuranic wastes that are retrievably stored in the 200 Area burial grounds and facilities in addition to newly generated wastes. Certification of retrievably stored wastes processing in WRAP 1 is required to meet the waste acceptance criteria for onsite treatment and disposal of low-level waste and mixed low-level waste and the Waste Isolation Pilot Plant Waste Acceptance Criteria for the disposal of TRU waste. In addition, these wastes will need to be certified for packaging in TRUPACT-II shipping containers. Characterization of the retrievably stored waste is needed to support the certification process. Characterization data will be obtained from historical records, process knowledge, nondestructive examination nondestructive assay, visual inspection of the waste, head-gas sampling, and analysis of samples taken from the waste containers. Sample characterization refers to the method or methods that are used to test waste samples for specific analytes. The focus of this study is the sample characterization needed to accurately identify the hazardous and radioactive constituents present in the retrieved wastes that will be processed in WRAP 1. In addition, some sampling and characterization will be required to support NDA calculations and to provide an over-check for the characterization of newly generated wastes. This study results in the baseline definition of WRAP 1 sampling and analysis requirements and identifies alternative methods to meet these requirements in an efficient and economical manner

  16. Properties of fly ash and metakaolín based geopolymer panels under fire resistance tests

    Directory of Open Access Journals (Sweden)

    Luna-Galiano, Y.

    2015-09-01

    Full Text Available This paper presents the results of a study about the effect of fire on geopolymer paste composed of fly ashes, metakaolin and sodium silicate. 2 cm thick, 28 cm high and 18 cm wide panels were filled with the paste obtained. After 28 days of curing at 20 °C and 45% of relative humidity, different tests were carried out in the geopolymers: physico-chemical (density, water absorption, porosity, mechanical (flexural and compressive strength, fire resistance and environmental (leaching and radioactivity. The panels manufactured have been compared with other commercial panels in order to determine the recycling possibilities of fly ashes in manufacturing new fire-insulating geopolymers. The panels obtained can be utilized for the production of interior wall materials, with a good physical, mechanical, fire resistant properties without any environmental problem.Este documento presenta los resultados de un estudio sobre el efecto del fuego sobre pastas de geopolímeros compuestas de cenizas volantes, metacaolín y silicato sódico. Con la pasta obtenida se han rellenado paneles de dimensiones 2 cm de espesor, 28 cm de altura y 18 cm de ancho. Tras 28 días de curado a 20 °C y un 45% de humedad relativa, diferentes ensayos fueron realizados en los geopolímeros obtenidos: fisicoquímicos (densidad, absorción de agua, porosidad, mecánicos (resistencia a compresión y a flexión, de resistencia al fuego y medioambientales (lixiviación y radioactividad. Los paneles fabricados han sido comparados con paneles comerciales para determinar las posibilidades de reciclaje de las cenizas volantes para la fabricación de nuevos productos geopoliméricos con propiedades aislantes al fuego. Los paneles obtenidos pueden ser utilizados para la producción de paredes interiores, con buenas propiedades físicas, mecánicas y de resistencia al fuego sin ningún problema medioambiental.

  17. Natural pozzolan-and granulated blast furnace slag-based binary geopolymers

    Directory of Open Access Journals (Sweden)

    Robayo, R. A.

    2016-03-01

    Full Text Available This study describes the synthesis at ambient temperature (25±3 °C of binary geopolymer systems based on natural volcanic pozzolan and granulated blast furnace slag. Na2SiO3 and NaOH were used as alkaline activators. The effects of the SiO2/Al2O3, Na2O/Al2O3 ratio and the amount of slag added (from 0 to 30% on the reaction kinetics, compressive strength and microstructure of the final product were studied. To characterise the geopolymer pastes, techniques such as X-ray diffraction (XRD, infrared spectroscopy (FTIR and scanning electron microscopy (SEM were used. The results indicate the possibility of obtaining a geopolymer cement with a compressive strength of up to 48.11 MPa after 28 days of curing at ambient temperature whose characteristics are comparable to those of commercial portland cement.Este trabajo describe la síntesis a temperatura ambiente (25±3 °C de sistemas geopoliméricos de tipo binario basados en una puzolana natural de origen volcánico y escoria siderúrgica de alto horno usando activadores alcalinos basados en la combinación de Na2SiO3 y NaOH. Se estudió el efecto de la relación SiO2/Al2O3, Na2O/Al2O3 y la cantidad de escoria adicionada en niveles entre el 0 y 30% sobre la cinética de reacción, la resistencia a la compresión y la microestructura del producto final. Para la caracterización de las pastas geopoliméricas se utilizaron técnicas como difracción de rayos X (DRX, espectroscopia infrarroja (FTIR y microscopia electrónica de barrido (MEB. Los resultados conseguidos revelan la posibilidad de obtener un cementante geopolimérico con una resistencia a la compresión de hasta 48,11 MPa a los 28 días de curado a temperatura ambiente cuyas características son comparables a las de un cemento portland comercial.

  18. Status of thermohydraulic studies of wire-wrapped bundles

    International Nuclear Information System (INIS)

    Khairallah, A.; Leteinturier, D.; Skok, J.

    1979-01-01

    A status review is presented of the work undertaken in CEA to acquire good understanding and description of the single-phase thermal-hydraulic problems in LMFBR wire-wrapped bundles. Design-type and reference-type calculational tools developed for the study of forced convection in nominal and distorted bundle geometries are briefly presented. Local hot spots and mixed convection situations are discussed in some more details. Out-of-pile and in-pile experimental programs designed in support to code development are described. (author)

  19. Infinite volume of noncommutative black hole wrapped by finite surface

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Baocheng, E-mail: zhangbc.zhang@yahoo.com [School of Mathematics and Physics, China University of Geosciences, Wuhan 430074 (China); You, Li, E-mail: lyou@mail.tsinghua.edu.cn [State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084 (China)

    2017-02-10

    The volume of a black hole under noncommutative spacetime background is found to be infinite, in contradiction with the surface area of a black hole, or its Bekenstein–Hawking (BH) entropy, which is well-known to be finite. Our result rules out the possibility of interpreting the entropy of a black hole by counting the number of modes wrapped inside its surface if the final evaporation stage can be properly treated. It implies the statistical interpretation for the BH entropy can be independent of the volume, provided spacetime is noncommutative. The effect of radiation back reaction is found to be small and doesn't influence the above conclusion.

  20. Behavior of FRP-Confined Concrete-Filled Steel Tube Columns

    Directory of Open Access Journals (Sweden)

    Yiyan Lu

    2014-05-01

    Full Text Available This paper presents the results of an experimental study into the behavior of concrete-filled steel tube columns confined by fiber-reinforced polymer (FRP. Eleven columns were tested to investigate the effects of the FRP layer number, the thickness of the steel tube and concrete strength on their load capacity and axial deformation capacity. The experimental results indicated that the FRP wrap can effectively confine the concrete expansion and delay the local buckling of the steel tube. Both the load capacity and the axial deformation capacity of concrete-filled steel tube columns can be substantially enhanced with FRP confinement. A model is proposed to predict the load capacity of the FRP-confined concrete-filled steel tube columns. The predicted results are generally in good agreement with the experimental ones obtained in this study and in the literature.

  1. Waste receiving and processing (WRAP) module 1 hazards assessment. Revision 1

    International Nuclear Information System (INIS)

    Sutton, L.N.

    1997-01-01

    This report documents the hazards assessment for the Waste Receiving and Processing Module I (WRAP 1) located on the U.S. Department of Energy (DOE) Hanford Site. Operation of the WRAP 1 is the responsibility of Rust Federal Services Hanford (RFSH). This hazards assessment was conducted to provide the emergency planning technical basis for the WRAP 1. DOE Orders require an emergency planning hazards assessment for each facility that has the potential to reach or exceed the lowest level emergency classification

  2. New composites of nanoparticle Cu (I) oxide and titania in a novel inorganic polymer (geopolymer) matrix for destruction of dyes and hazardous organic pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Falah, Mahroo [MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington (New Zealand); MacKenzie, Kenneth J.D., E-mail: Kenneth.mackenzie@vuw.ac.nz [MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington (New Zealand); Knibbe, Ruth [Robinson Research Institute, Victoria University of Wellington (New Zealand); Page, Samuel J.; Hanna, John V. [Department of Physics, Warwick University, Coventry CV4 7AL (United Kingdom)

    2016-11-15

    Highlights: • Synthesis reported of new photoactive nano-oxide composites in a geopolymer matrix. • The novel aluminosilicate matrix is expanded with cetyltrimethylammonium bromide. • The photoactive component consists of a Cu(I) oxide and titania heterostructure. • Composites remove the model pollutant by both adsorption and photodegradation. • These new photocatalysts are extremely efficient and ecologically friendly. - Abstract: New photoactive composites to efficiently remove organic dyes from water are reported. These consist of Cu{sub 2}O/TiO{sub 2} nanoparticles in a novel inorganic geopolymer matrix modified by a large tertiary ammonium species (cetyltrimethylammonium bromide, CTAB) whose presence in the matrix is demonstrated by FTIR spectroscopy. The CTAB does not disrupt the tetrahedral geopolymer structural silica and alumina units as demonstrated by {sup 29}Si and {sup 27}Al MAS NMR spectroscopy. SEM/EDS, TEM and BET measurements suggest that the Cu{sub 2}O/TiO{sub 2} nanoparticles are homogenously distributed on the surface and within the geopolymer pores. The mechanism of removal of methylene blue (MB) dye from solution consists of a combination of adsorption (under dark conditions) and photodegradation (under UV radiation). MB adsorption in the dark follows pseudo second-order kinetics and is described by Freundlich-Langmuir type isotherms. The performance of the CTAB-modified geopolymer based composites is superior to composites based on unmodified geopolymer hosts, the most effective composite containing 5 wt% Cu{sub 2}O/TiO{sub 2} in a CTAB-modified geopolymer host. These composites constitute a new class of materials with excellent potential in environmental protection applications.

  3. Columns in Clay

    Science.gov (United States)

    Leenhouts, Robin

    2010-01-01

    This article describes a clay project for students studying Greece and Rome. It provides a wonderful way to learn slab construction techniques by making small clay column capitols. With this lesson, students learn architectural vocabulary and history, understand the importance of classical architectural forms and their influence on today's…

  4. Slender CRC Columns

    DEFF Research Database (Denmark)

    Aarup, Bendt; Jensen, Lars Rom; Ellegaard, Peter

    2005-01-01

    CRC is a high-performance steel fibre reinforced concrete with a typical compressive strength of 150 MPa. Design methods for a number of structural elements have been developed since CRC was invented in 1986, but the current project set out to further investigate the range of columns for which...

  5. Practical column design guide

    CERN Document Server

    Nitsche, M

    2017-01-01

    This book highlights the aspects that need to be considered when designing distillation columns in practice. It discusses the influencing parameters as well as the equations governing them, and presents several numerical examples. The book is intended both for experienced designers and for those who are new to the subject.

  6. Extending the shelf life of fresh sweet corn by shrink-wrapping, refrigeration, and irradiation

    International Nuclear Information System (INIS)

    Deak, T.

    1987-01-01

    Chemical, physical, sensory, and microbiological changes were monitored during storage of unwrapped and shrink-wrapped fresh sweet corn at 10 degree and 20 degree C. Wrapping essentially eliminated moisture loss and resulted in elevated carbon dioxide and decreased oxygen concentrations within packages. These effects, together with refrigeration markedly reduced the changes associated with senscence and post harvest deterioration, and hence resulted in at least a threefold extension in shelf life. The water-saturated atmosphere, however, enhanced microbial growth on shrink-wrapped corn. The initial microbial population was effectively decreased by treating the wrapped corn with 0.5 or 1.0 kGy (Co 60 ) irradiation

  7. In Situ Elevated Temperature Testing of Fly Ash Based Geopolymer Composites

    Science.gov (United States)

    Vickers, Les; Pan, Zhu; Tao, Zhong; van Riessen, Arie

    2016-01-01

    In situ elevated temperature investigations using fly ash based geopolymers filled with alumina aggregate were undertaken. Compressive strength and short term creep tests were carried out to determine the onset temperature of viscous flow. Fire testing using the standard cellulose curve was performed. Applying a load to the specimen as the temperature increased reduced the temperature at which viscous flow occurred (compared to test methods with no applied stress). Compressive strength increased at the elevated temperature and is attributed to viscous flow and sintering forming a more compact microstructure. The addition of alumina aggregate and reduction of water content reduced the thermal conductivity. This led to the earlier onset and shorter dehydration plateau duration times. However, crack formation was reduced and is attributed to smaller thermal gradients across the fire test specimen. PMID:28773568

  8. Synthesis of geopolymer from rice husk ash for biodiesel production of Calophyllum inophyllum seed oil

    Science.gov (United States)

    Saputra, E.; Nugraha, M. W.; Helwani, Z.; Olivia, M.; Wang, S.

    2018-04-01

    In this work, geopolymer was prepared from rice husk ash (RHA) made into sodium silicate then synthesized by reacting metakaolin, NaOH, and water. The catalyst was characterized using Scanning Electron Microscopy (SEM), Energy-dispersive X-Ray analysis (EDX), Brunaeur Emmet Teller (BET), and basic strength. Then, the catalyst used for transesterification of Calophyllum inophyllum seed oil in order to produce biodiesel. The variation of process variables conducted to assess the effect on the yield of biodiesel. The highest yield obtained 87.68% biodiesel with alkyl ester content 99.29%, density 866 kg/m3, viscosity 4.13 mm2/s, the acid number of 0.42 mg-KOH/g biodiesel and the flash point 140 °C. Generally, variations of %w/w catalyst provides a dominant influence on the yield response of biodiesel. The physicochemical properties of the produced biodiesel comply with ASTM standard specifications.

  9. Bond Strength Mechanism of Fly Ash Based Geopolymer Mortars: A Review

    Science.gov (United States)

    Zailani, W. W. A.; Abdullah, M. M. A. B.; Razak, R. A.; Zainol, M. R. R. M. A.; Tahir, M. F. M.

    2017-11-01

    Geopolymer possess many excellent properties such as high compressive and bond strength, long term durability, better acid resistance and also known as a “Sustainable Material” due to its low carbon emission and low energy consumption. Thus, it is a good opportunity to develop and explore not only for cement and concrete but also as geopolymeric repair materials. This reviews showed that good bonding properties between geopolymeric repair material and concrete substrate is important in order to acquire an enhanced resistance against penetration of harmful substances and avoiding respalling of the repair material by understanding the bonding behaviour. Bond strength depends to the properties of the repair materials itself and also the surface preparations of concrete substrate.

  10. In Situ Elevated Temperature Testing of Fly Ash Based Geopolymer Composites

    Directory of Open Access Journals (Sweden)

    Les Vickers

    2016-06-01

    Full Text Available In situ elevated temperature investigations using fly ash based geopolymers filled with alumina aggregate were undertaken. Compressive strength and short term creep tests were carried out to determine the onset temperature of viscous flow. Fire testing using the standard cellulose curve was performed. Applying a load to the specimen as the temperature increased reduced the temperature at which viscous flow occurred (compared to test methods with no applied stress. Compressive strength increased at the elevated temperature and is attributed to viscous flow and sintering forming a more compact microstructure. The addition of alumina aggregate and reduction of water content reduced the thermal conductivity. This led to the earlier onset and shorter dehydration plateau duration times. However, crack formation was reduced and is attributed to smaller thermal gradients across the fire test specimen.

  11. Pressure drop measurements in LMFBR wire wrapped blanket assemblies

    International Nuclear Information System (INIS)

    Chiu, C.; Hawley, J.; Rohsenow, W.M.; Todreas, N.E.

    1977-07-01

    In this experiment, measurements of subchannel static pressure for an interior and edge subchannel were taken at two elevations in two wire-wrapped 61-pin bundles. One of the bundles has geometric characteristics of P/D = 1.067 and H/D = 8.0 (4 inch lead length and 0.501 inch rod diameter) and the other bundle has geometric characteristics of P/D = 1.067 and H/D = 4.0 (2 inch lead length and 0.501 inch rod diameter). The bundle average friction factors as well as the local subchannel friction factors for both interior and edge subchannels were determined from the experimental static pressure data. The average subchannel flow rates for both edge and interior subchannels were determined in a separate experiment. Results show that two correlations suggested by Rehme and Novendstern for the bundle average friction factor cannot predict the data within the range of experimental error. The bundle average friction factors for both bundles under test were underestimated by Rehme's correlation and overestimated by Novendstern's correlation. The results of the local subchannel friction factors indicate the effect of the wire lead length is more pronounced in the interior subchannel friction factor than in the edge subchannel friction factor. As the wire wrap lead length decreases, both interior and edge subchannel friction factors increase

  12. Hairy Graphenes: Wrapping Nanocellulose Nets around Graphene Oxide Sheets.

    Science.gov (United States)

    Xiong, Rui; Kim, Ho Shin; Korolovych, Volodymyr F; Zhang, Shuaidi; Yingling, Yaroslava; Tsukruk, Vladimir V

    2018-04-17

    Constructing advanced functional nanomaterials with pre-designed organized morphologies from low-dimension synthetic and biological components is extremely challenging because of complex inter-component interactions, high-aspect ratios, flexible shapes, crumpling instabilities and limited common wet-chemistry processing conditions. Herein, we report an efficient and universal amphiphilicity-driven assembly strategy to construct "hairy" flexible hybrid nanosheets with the net of 1D cellulose nanofibers (CNFs) conformally wrapped around 2D graphene oxide (GO) monolayers. This interface-driven bio-synthetic assembly is facilitated by variable amphiphilic interfacial balance via tailoring the surface chemistry of flexible GO sheets as controllably pre-oxidized 2D template cores, resulting in individual sheets tightly surrounded by dense conformal nanocellulose network. These nanocellulose-net wrapped GO nanosheets demonstrate extremely high compressive elastic modulus above 180 GPa due to the strong bonding between nanofibers and GO sheets and arrest of the buckling events. This unique mechanical stability far exceeds the compressive instability limits of both individual components, 1D cellulose nanofibers and 2D graphene monolayers. Additionally, the presence of CNF reinforced nanocellulose network significantly enhances the wetting ability of initial hydrophobic reduced GO nanosheets, enabling the long-term stability of CNFs-rGO dispersion and allowing fast water transport combined with high filtration efficiency for CNFs-rGO membranes. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Pressure drop measurements in LMFBR wire wrapped blanket assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Chiu, C.; Hawley, J.; Rohsenow, W.M.; Todreas, N.E.

    1977-07-01

    In this experiment, measurements of subchannel static pressure for an interior and edge subchannel were taken at two elevations in two wire-wrapped 61-pin bundles. One of the bundles has geometric characteristics of P/D = 1.067 and H/D = 8.0 (4 inch lead length and 0.501 inch rod diameter) and the other bundle has geometric characteristics of P/D = 1.067 and H/D = 4.0 (2 inch lead length and 0.501 inch rod diameter). The bundle average friction factors as well as the local subchannel friction factors for both interior and edge subchannels were determined from the experimental static pressure data. The average subchannel flow rates for both edge and interior subchannels were determined in a separate experiment. Results show that two correlations suggested by Rehme and Novendstern for the bundle average friction factor cannot predict the data within the range of experimental error. The bundle average friction factors for both bundles under test were underestimated by Rehme's correlation and overestimated by Novendstern's correlation. The results of the local subchannel friction factors indicate the effect of the wire lead length is more pronounced in the interior subchannel friction factor than in the edge subchannel friction factor. As the wire wrap lead length decreases, both interior and edge subchannel friction factors increase.

  14. Optimizing and Characterizing Geopolymers from Ternary Blend of Philippine Coal Fly Ash, Coal Bottom Ash and Rice Hull Ash

    Directory of Open Access Journals (Sweden)

    Martin Ernesto Kalaw

    2016-07-01

    Full Text Available Geopolymers are inorganic polymers formed from the alkaline activation of amorphous alumino-silicate materials resulting in a three-dimensional polymeric network. As a class of materials, it is seen to have the potential of replacing ordinary Portland cement (OPC, which for more than a hundred years has been the binder of choice for structural and building applications. Geopolymers have emerged as a sustainable option vis-à-vis OPC for three reasons: (1 their technical properties are comparable if not better; (2 they can be produced from industrial wastes; and (3 within reasonable constraints, their production requires less energy and emits significantly less CO2. In the Philippines, the use of coal ash, as the alumina- and silica- rich geopolymer precursor, is being considered as one of the options for sustainable management of coal ash generation from coal-fired power plants. However, most geopolymer mixes (and the prevalent blended OPC use only coal fly ash. The coal bottom ash, having very few applications, remains relegated to dumpsites. Rice hull ash, from biomass-fired plants, is another silica-rich geopolymer precursor material from another significantly produced waste in the country with only minimal utilization. In this study, geopolymer samples were formed from the mixture of coal ash, using both coal fly ash (CFA and coal bottom ash (CBA, and rice hull ash (RHA. The raw materials used for the geopolymerization process were characterized using X-ray fluorescence spectroscopy (XRF for elemental and X-ray diffraction (XRD for mineralogical composition. The raw materials’ thermal stability and loss on ignition (LOI were determined using thermogravimetric analysis (TGA and reactivity via dissolution tests and inductively-coupled plasma mass spectrometry (ICP analysis. The mechanical, thermal and microstructural properties of the geopolymers formed were analyzed using compression tests, Fourier transform infra-red spectroscopy (FTIR

  15. Optimizing and Characterizing Geopolymers from Ternary Blend of Philippine Coal Fly Ash, Coal Bottom Ash and Rice Hull Ash.

    Science.gov (United States)

    Kalaw, Martin Ernesto; Culaba, Alvin; Hinode, Hirofumi; Kurniawan, Winarto; Gallardo, Susan; Promentilla, Michael Angelo

    2016-07-15

    Geopolymers are inorganic polymers formed from the alkaline activation of amorphous alumino-silicate materials resulting in a three-dimensional polymeric network. As a class of materials, it is seen to have the potential of replacing ordinary Portland cement (OPC), which for more than a hundred years has been the binder of choice for structural and building applications. Geopolymers have emerged as a sustainable option vis-à-vis OPC for three reasons: (1) their technical properties are comparable if not better; (2) they can be produced from industrial wastes; and (3) within reasonable constraints, their production requires less energy and emits significantly less CO₂. In the Philippines, the use of coal ash, as the alumina- and silica- rich geopolymer precursor, is being considered as one of the options for sustainable management of coal ash generation from coal-fired power plants. However, most geopolymer mixes (and the prevalent blended OPC) use only coal fly ash. The coal bottom ash, having very few applications, remains relegated to dumpsites. Rice hull ash, from biomass-fired plants, is another silica-rich geopolymer precursor material from another significantly produced waste in the country with only minimal utilization. In this study, geopolymer samples were formed from the mixture of coal ash, using both coal fly ash (CFA) and coal bottom ash (CBA), and rice hull ash (RHA). The raw materials used for the geopolymerization process were characterized using X-ray fluorescence spectroscopy (XRF) for elemental and X-ray diffraction (XRD) for mineralogical composition. The raw materials' thermal stability and loss on ignition (LOI) were determined using thermogravimetric analysis (TGA) and reactivity via dissolution tests and inductively-coupled plasma mass spectrometry (ICP) analysis. The mechanical, thermal and microstructural properties of the geopolymers formed were analyzed using compression tests, Fourier transform infra-red spectroscopy (FTIR), scanning

  16. Recycling of Pre-Washed Municipal Solid Waste Incinerator Fly Ash in the Manufacturing of Low Temperature Setting Geopolymer Materials

    Directory of Open Access Journals (Sweden)

    Raffaele Cioffi

    2013-08-01

    Full Text Available In this work, three samples of municipal solid waste incinerators fly ash (MSWI-FA have been stabilized in systems containing coal fly ash to create geopolymers through a polycondensation reaction. Monolithic products have been obtained with both MSWI fly ash as received and after the partial removal of chloride and sulfate by water washing. The polycondensation products have been characterized qualitatively by means of Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy and quantitatively, through the determination of the volume of reacted water and silicate. Furthermore, the heavy metals and chloride releases together with the physico-mechanical properties have been evaluated on the hardened products. In conclusion, considering the technological and environmental performances of the obtained geopolymers, they could be suitable for many non-structural applications, such as backfilling of abandoned quarries, decorative materials or brick fireplaces, hearths, patios, etc.

  17. Recycling of Pre-Washed Municipal Solid Waste Incinerator Fly Ash in the Manufacturing of Low Temperature Setting Geopolymer Materials.

    Science.gov (United States)

    Ferone, Claudio; Colangelo, Francesco; Messina, Francesco; Santoro, Luciano; Cioffi, Raffaele

    2013-08-12

    In this work, three samples of municipal solid waste incinerators fly ash (MSWI-FA) have been stabilized in systems containing coal fly ash to create geopolymers through a polycondensation reaction. Monolithic products have been obtained with both MSWI fly ash as received and after the partial removal of chloride and sulfate by water washing. The polycondensation products have been characterized qualitatively by means of Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy and quantitatively, through the determination of the volume of reacted water and silicate. Furthermore, the heavy metals and chloride releases together with the physico-mechanical properties have been evaluated on the hardened products. In conclusion, considering the technological and environmental performances of the obtained geopolymers, they could be suitable for many non-structural applications, such as backfilling of abandoned quarries, decorative materials or brick fireplaces, hearths, patios, etc.

  18. Physical-chemistry of Nawangan’s phyropyllite and its prospective as environmental friendly geopolymer materials

    Science.gov (United States)

    Mutrofin, S.; Setyaningsih, T.; Wati, F. N.; Purwonugroho, D.

    2018-01-01

    The chemical composition and thermal behaviour of Nawangan-phyropyllite have been studied using XRF, powder XRD and FTIR. The fourier transfornation infrared was applied to analyze the phyropyllite after treating by calcinating at variuos temperature. Initial investigation has also been carried out by adding sodium hydroxide and potassium hydroxide to study the possiblity of phyropyllite as geopolymer materials. The phyropyllite contains Si(57.7% ), Al(16,7%), K (20.6%), Fe (2.47%) Ti (2.33%) and Cu (0.088%). Based on the XRD difractogram, peaks at 2 theta (9°, 20°, 21°, 26°, 34°, 36° and 39°) were characteristic for phyropyllite. While, infrared study showed that at 3630 cm-1, 756 cm-1 and 938 cm-1 are responsible for phyropyllite’s peaks. The hydroxyl bonded to alumina still existed under heating up to 400 °C and disappered at 600 °C. It indicted that covalent bond of Al-OH was broken. By heating at 600 °C, the peak at 1021 cm-1 splitted into two peaks, 990 cm-1 and 1049 cm-1. It may be due to the displacive transition. By adding NaOH 10 M, the peak intensity of Al-OH (3630 cm-1) reduced to 17% but the peak intensity of Al=O (1661 cm-1) incresed to 14% and the new peak (5%) emerged at 1387 cm-1(O-Al-O). The most reactive phyropyllite was obatained by adding KOH 5 M. The present of reactive functional groups (Al=O, O-Al-O and Al-OH) indicates that the local phyropyllite has a good change as geopolymer materials.

  19. Experimental Tests on Bending Behavior of Profiled Steel Sheeting Dry Board Composite Floor with Geopolymer Concrete Infill

    Directory of Open Access Journals (Sweden)

    Mohd Isa Jaffar

    Full Text Available Abstract Profiled Steel Sheet Dry Board (PSSDB system is a lightweight composite structure comprises Profiled Steel Sheeting and Dry Board connected by self-drilling and self-tapping screws. This study introduced geopolymer concrete, an eco-friendly material without cement content as an infill material in the PSSDB floor system to highlight its effect onto the PSSDB (with full and half-size dry boards floor system's stiffness and strength. Experimental tests on various full scale PSSDB floor specimens were conducted under uniformly distributed transverse loads. Results illustrate that the rigidity of the panel with geopolymer concrete infill with half-size dry board (HBGPC increases by 43% relative to that of the panel with normal concrete infill with full-size dry board (FBNC. The developed finite-element modeling (FEM successfully predicts the behavior of FBGPC model with 94.8% accuracy. Geopolymer concrete infill and dry board size influence the strength panel, infill contact stiffness, and mid-span deflection of the profiled steel sheeting/dry board (PSSDB flooring system.

  20. Basic Physical – Mechanical Properties of Geopolymers Depending on the Content of Ground Fly Ash and Fines of Sludge

    Directory of Open Access Journals (Sweden)

    Sičáková Alena

    2017-06-01

    Full Text Available The binding potential of fly ash (FA as a typical basic component of building mixtures can be improved in mechanical way, which unfolds new possibilities of its utilization. This paper presents the possibilities of preparing the geopolymer mixtures based on ground (dm = 31.0 μm FA, used in varying percentages to the original (unground; dm = 74.1 μm one. As a modification, fine-grain sludge from the process of washing the crushed aggregates was used as filler in order to obtain mortar-type material. The basic physical-mechanical properties of mixtures are presented and discussed in the paper, focusing on time dependence. The following standard tests were executed after 2, 7, 28, and 120 days: density, total water absorption, flexural strength, and compressive strength. Ground FA provided for positive effect in all tested parameters, while incorporation of fine portion of sludge into the geopolymer mixture does not offer a significant technical profit. On the other hand, it does not cause the decline in the properties, so the environmental effect (reduction of environmental burden can be applied through its incorporation into the geopolymer mixtures.

  1. Basic Physical - Mechanical Properties of Geopolymers Depending on the Content of Ground Fly Ash and Fines of Sludge

    Science.gov (United States)

    Sičáková, Alena; Števulová, Nadežda

    2017-06-01

    The binding potential of fly ash (FA) as a typical basic component of building mixtures can be improved in mechanical way, which unfolds new possibilities of its utilization. This paper presents the possibilities of preparing the geopolymer mixtures based on ground (dm = 31.0 μm) FA, used in varying percentages to the original (unground; dm = 74.1 μm) one. As a modification, fine-grain sludge from the process of washing the crushed aggregates was used as filler in order to obtain mortar-type material. The basic physical-mechanical properties of mixtures are presented and discussed in the paper, focusing on time dependence. The following standard tests were executed after 2, 7, 28, and 120 days: density, total water absorption, flexural strength, and compressive strength. Ground FA provided for positive effect in all tested parameters, while incorporation of fine portion of sludge into the geopolymer mixture does not offer a significant technical profit. On the other hand, it does not cause the decline in the properties, so the environmental effect (reduction of environmental burden) can be applied through its incorporation into the geopolymer mixtures.

  2. On The Physico-Mechanics, Thermal and Microstructure Properties of Hybrid Composite Epoxy-Geopolymer for Geothermal Pipe Application

    Directory of Open Access Journals (Sweden)

    Firawati Ira

    2017-01-01

    Full Text Available The objective of this study is to determine the effect of epoxy resin on the physico-mechanics, thermal and microstructure properties of geopolymers hybrid composites for geothermal pipe application. Hybrid composite epoxy-geopolymers pipes were produced through alkali activation method of class-C fly ash and epoxy resin. The mass of epoxy-resin was varied relative to the mass of fly ash namely 0% (SPG01, 5% (SPG02, 10% (SPG03, 15% (SPG04, and 20% (SPG05. The resulting materials were stored in open air for 28 days before conducting any measurements. The densities of the product composites were measured before and after the samples immersed in boiling water for 3 hours. The mechanical strength of the resulting geothermal pipes was measured by using splitting tensile measurement. The thermal properties of the pipes were measured by means of thermal conductivity measurement, differential scanning calorimetry (DSC and fire resistance measurements. The chemical resistance was measured by immersing the samples into 1M H2SO4 solution for 4 days. The microstructure properties of the resulting materials were examined by using x-ray diffraction (XRD and Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS. The results of this study showed that hybrid composite epoxy-geopolymers SPG02 and SPG03 are suitable to be applied as geothermal pipes.

  3. Optimization and influence of parameter affecting the compressive strength of geopolymer concrete containing recycled concrete aggregate: using full factorial design approach

    Science.gov (United States)

    Krishnan, Thulasirajan; Purushothaman, Revathi

    2017-07-01

    There are several parameters that influence the properties of geopolymer concrete, which contains recycled concrete aggregate as the coarse aggregate. In the present study, the vital parameters affecting the compressive strength of geopolymer concrete containing recycled concrete aggregate are analyzedby varying four parameters with two levels using full factorial design in statistical software Minitab® 17. The objective of the present work is to gain an idea on the optimization, main parameter effects, their interactions and the predicted response of the model generated using factorial design. The parameters such as molarity of sodium hydroxide (8M and 12M), curing time (6hrs and 24 hrs), curing temperature (60°C and 90°C) and percentage of recycled concrete aggregate (0% and 100%) are considered. The results show that the curing time, molarity of sodium hydroxide and curing temperature were the orderly significant parameters and the percentage of Recycled concrete aggregate (RCA) was statistically insignificant in the production of geopolymer concrete. Thus, it may be noticeable that the RCA content had negligible effect on the compressive strength of geopolymer concrete. The expected responses from the generated model showed a satisfactory and rational agreement to the experimental data with the R2 value of 97.70%. Thus, geopolymer concrete comprising recycled concrete aggregate can solve the major social and environmental concerns such as the depletion of the naturally available aggregate sources and disposal of construction and demolition waste into the landfill.

  4. Nine Words - Nine Columns

    DEFF Research Database (Denmark)

    Trempe Jr., Robert B.; Buthke, Jan

    2016-01-01

    This book records the efforts of a one-week joint workshop between Master students from Studio 2B of Arkitektskolen Aarhus and Master students from the Harbin Institute of Technology in Harbin, China. The workshop employed nine action words to instigate team-based investigation into the effects o...... as formwork for the shaping of wood veneer. The resulting columns ‘wear’ every aspect of this design pipeline process and display the power of process towards an architectural resolution....

  5. The Hanford Site solid waste treatment project; Waste Receiving and Processing (WRAP) Facility

    International Nuclear Information System (INIS)

    Roberts, R.J.

    1991-01-01

    The Waste Receiving and Processing (WRAP) Facility will provide treatment and temporary storage (consisting of in-process storage) for radioactive and radioactive/hazardous mixed waste. This facility must be constructed and operated in compliance with all appropriate US Department of Energy (DOE) orders and Resource Conservation and Recovery Act (RCRA) regulations. The WRAP Facility will examine and certify, segregate/sort, and treat for disposal suspect transuranic (TRU) wastes in drums and boxes placed in 20-yr retrievable storage since 1970; low-level radioactive mixed waste (RMW) generated and placed into storage at the Hanford Site since 1987; designated remote-handled wastes; and newly generated TRU and RMW wastes from high-level waste (HLW) recovery and processing operations. In order to accelerated the WRAP Project, a partitioning of the facility functions was done in two phases as a means to expedite those parts of the WRAP duties that were well understood and used established technology, while allowing more time to better define the processing functions needed for the remainder of WRAP. The WRAP Module 1 phase one, is to provide the necessary nondestructive examination and nondestructive assay services, as well as all transuranic package transporter (TRUPACT-2) shipping for both WRAP Project phases, with heating, ventilation, and air conditioning; change rooms; and administrative services. Phase two of the project, WRAP Module 2, will provide all necessary waste treatment facilities for disposal of solid wastes. 1 tab

  6. Effect of scopoletin on fascia-wrapped diced cartilage grafts | Zeng ...

    African Journals Online (AJOL)

    Purpose: To evaluate the effect of scopoletin (SL) on fascia-wrapped diced cartilage grafts in rhinoplasty surgery. Methods: Cartilage grafts (2 × 2 cm) from the ears of New Zealand rabbits were diced into sections (1 mm3) and then wrapped in muscle fascia taken from the right rear leg. Each graft was placed on the back of ...

  7. Technical safety requirements (TSR) for waste receiving and processing (WRAP) facility

    International Nuclear Information System (INIS)

    Weidert, J.R.

    1997-01-01

    The scope of this TSR document is based on the WRAP Final Safety Analysis Report (HNF-SD-W026-SAR-002) and supporting documents. The administrative controls set forth in this TSR document are derived from the WRAP Final Safety Analysis Report

  8. NMFS Water Column Sonar Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water column sonar data are an important component of fishery independent surveys, habitat studies and other research. NMFS water column sonar data are archived here.

  9. The first biopolymer-wrapped non-carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Shamsi, Mohtashim H; Geckeler, Kurt E [Laboratory of Applied Macromolecular Chemistry, Department of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), 261-Cheomdan-gwagiro, Buk-gu, Gwangju 500-712 (Korea, Republic of)], E-mail: keg@gist.ac.kr

    2008-02-20

    DNA-wrapped halloysite nanotubes were obtained by a mechanochemical reaction in the solid state. The characterization by scanning electron microscopy showed that the nanotubes were cut into shorter lengths and were completely covered with DNA. This resulted in a high aqueous solubility of the product with stability of the solution for about 6 weeks. The nanotubes were cut to different fractions with lengths of 200-400 nm (30-40%), 400-600 nm (10-20%) and 600-800 nm (5-10%) after ball milling. FTIR spectroscopic analysis shows that the DNA in the product remained intact. This straightforward technique for obtaining water-soluble halloysite nanotubes by a solid-state reaction has great potential for biomedical applications of nanotubes.

  10. The first biopolymer-wrapped non-carbon nanotubes

    International Nuclear Information System (INIS)

    Shamsi, Mohtashim H; Geckeler, Kurt E

    2008-01-01

    DNA-wrapped halloysite nanotubes were obtained by a mechanochemical reaction in the solid state. The characterization by scanning electron microscopy showed that the nanotubes were cut into shorter lengths and were completely covered with DNA. This resulted in a high aqueous solubility of the product with stability of the solution for about 6 weeks. The nanotubes were cut to different fractions with lengths of 200-400 nm (30-40%), 400-600 nm (10-20%) and 600-800 nm (5-10%) after ball milling. FTIR spectroscopic analysis shows that the DNA in the product remained intact. This straightforward technique for obtaining water-soluble halloysite nanotubes by a solid-state reaction has great potential for biomedical applications of nanotubes

  11. Realization, characterization and functionalization of lipidic wrapped carbon nanotubes

    International Nuclear Information System (INIS)

    Ciofani, Gianni; Obata, Yosuke; Sato, Izumi; Okamura, Yosuke; Raffa, Vittoria; Menciassi, Arianna; Dario, Paolo; Takeda, Naoya; Takeoka, Shinji

    2009-01-01

    Mass-produced carbon nanotubes (CNTs) are strongly aggregated and highly hydrophobic, and processes to make them water soluble are required for biological applications. Both covalent and non-covalent strategies are pursued for obtaining stable, highly concentrated CNT aqueous dispersions. Covalent functionalization has the great disadvantage of producing an irreversible chemical modification of nanotubes, thus alterating their mechanical, chemical and electric properties. On the other hand, non-covalent functionalization is often obtained by employing surfactants that sensibly affect cell viability. Moreover, derivatization with biological moieties is often impossible through non-covalent CNT dispersion. This paper proposes a non-covalent dispersion of multi-wall CNT based on a lipidic mixture that can guarantee high concentration and high stability as well as high cytocompatibility. Moreover, CNTs wrapped with a lipid membrane are realized to demonstrate that the proposed CNTs can be functionalised with a dodecapeptide that specifically recognizes activated platelets without chemical modification of the nanotube itself.

  12. Acoustic emission from fiber reinforced plastic damaged hoop wrapped cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Akhtar, A.; Kung, D.; Westbrook, D.R.

    2000-03-01

    Metal lined continuous fiber reinforced plastic (FRP) hoop wrapped cylinders with axial cuts to the FRP were modeled mathematically and tested experimentally. Steel lined and aluminum alloy lined glass FRP vessels were subjected to acoustic emission tests (AE) and hydraulic burst tests. The burst pressure decreased monotonically with the length of the axial cut. Acoustic emission increased initially with a decrease in burst pressure, and attained a maximum at an intermediate level of damage to the FRP. However, acoustic emission decreased when the level of damage was higher and the burst pressure was lower. Implications of the findings are discussed in the context of the search for an acoustic emission test method to inspect periodically the vessels used for the storage of compressed gaseous fuels on natural gas vehicles (NGV) and hydrogen vehicles.

  13. WRAP low level waste (LLW) glovebox acceptance test report

    International Nuclear Information System (INIS)

    Leist, K.J.

    1998-01-01

    In June 28, 1997, the Low Level Waste (LLW) glovebox was tested using glovebox acceptance test procedure 13031A-85. The primary focus of the glovebox acceptance test was to examine control system interlocks, display menus, alarms, and operator messages. Limited mechanical testing involving the drum ports, hoists, drum lifter, compacted drum lifter, drum tipper, transfer car, conveyors, lidder/delidder device and the supercompactor were also conducted. As of November 24, 1997, 2 of the 131 test exceptions that affect the LLW glovebox remain open. These items will be tracked and closed via the WRAP Master Test Exception Database. As part of Test Exception resolution/closure the responsible individual closing the Test Exception performs a retest of the affected item(s) to ensure the identified deficiency is corrected, and, or to test items not previously available to support testing. Test Exceptions are provided as appendices to this report

  14. Wrapping up the bad news – HIV assembly and release

    Directory of Open Access Journals (Sweden)

    Meng Bo

    2013-01-01

    Full Text Available Abstract The late Nobel Laureate Sir Peter Medawar once memorably described viruses as ‘bad news wrapped in protein’. Virus assembly in HIV is a remarkably well coordinated process in which the virus achieves extracellular budding using primarily intracellular budding machinery and also the unusual phenomenon of export from the cell of an RNA. Recruitment of the ESCRT system by HIV is one of the best documented examples of the comprehensive way in which a virus hijacks a normal cellular process. This review is a summary of our current understanding of the budding process of HIV, from genomic RNA capture through budding and on to viral maturation, but centering on the proteins of the ESCRT pathway and highlighting some recent advances in our understanding of the cellular components involved and the complex interplay between the Gag protein and the genomic RNA.

  15. WRAP low level waste (LLW) glovebox acceptance test report

    Energy Technology Data Exchange (ETDEWEB)

    Leist, K.J.

    1998-02-17

    In June 28, 1997, the Low Level Waste (LLW) glovebox was tested using glovebox acceptance test procedure 13031A-85. The primary focus of the glovebox acceptance test was to examine control system interlocks, display menus, alarms, and operator messages. Limited mechanical testing involving the drum ports, hoists, drum lifter, compacted drum lifter, drum tipper, transfer car, conveyors, lidder/delidder device and the supercompactor were also conducted. As of November 24, 1997, 2 of the 131 test exceptions that affect the LLW glovebox remain open. These items will be tracked and closed via the WRAP Master Test Exception Database. As part of Test Exception resolution/closure the responsible individual closing the Test Exception performs a retest of the affected item(s) to ensure the identified deficiency is corrected, and, or to test items not previously available to support testing. Test Exceptions are provided as appendices to this report.

  16. GFRP seismic strengthening and structural heath monitoring of Portage Creek Bridge concrete columns

    International Nuclear Information System (INIS)

    Huffman, S.; Bagchi, A.; Mufti, A.; Neale, K.; Sargent, D.; Rivera, E.

    2006-01-01

    Located in Victoria British Columbia (BC), Canada, the Portage Creek Bridge is a 124m long, three-span structure with a reinforced concrete piers and abutments on H piles. The bridge was designed prior to the introduction of current bridge seismic design codes and construction practices. Therefore it was not designed to resist the earthquake forces as required by today's standards. The bridge is on a route classified as a Municipal Disaster Route scheduled to be retrofitted to prevent collapse during a design seismic event, with a return period of 475 years (i.e., an event with 105 probability of exceedance in 50 years). Conventional materials and methods were used to retrofit most of the bridge. The dynamic analysis of the bridge predicted the two tall columns of Pier No. 1 will form plastic hinges under an earthquake resulting an additional shear to the short columns of Pier No. 2. A non-liner static pushover analysis indicated the short columns will not be able to form plastic hinges prior to failure in shear. The innovative solution of Fiber Reinforced Polymer wraps (FRPs) was chosen to strengthen the short columns for shear without increasing the moment capacity. The FRP wraps and the bridge were instrumented as one of 36 demonstration projects across Canada sponsored by ISIS (Intelligent Sensing for Innovative Structure) Canada, federally funded Network of Centers of Excellence, to access the performance of FRP and the use of FOS (Fiber Optic Sensors) for Structural Health Monitoring (SHM). The two columns of the bridge pier were strengthened with GFRP (Glass Fiber Reinforced Polymer) wraps with eight bi-directional rosette type strain gauges and four long gauge fiber optic sensors attached to the outer layer of the wraps. In addition, two 3-D Crossbow accelerometers are installed on the pier cap above the columns and a traffic web-cam mounted above the deck at the pier location. The data is collected through high sped internet line to an interactive web page

  17. Functionalization of surfactant wrapped graphenenanosheets with alkylazides for enhanced dispersibility

    Science.gov (United States)

    Vadukumpully, Sajini; Gupta, Jhinuk; Zhang, Yongping; Xu, Guo Qin; Valiyaveettil, Suresh

    2011-01-01

    A facile and simple approach for the covalent functionalization of surfactant wrapped graphene sheets is described. The approach involves functionalization of dispersible graphene sheets with various alkylazides and 11-azidoundecanoic acid proved the best azide for enhanced dispersibility. The functionalization was confirmed by infrared spectroscopy and scanning tunneling microscopy. The free carboxylic acidgroups can bind to gold nanoparticles, which were introduced as markers for the reactive sites. The interaction between gold nanoparticles and the graphene sheets was followed by UV-vis spectroscopy. The gold nanoparticle-graphene composite was characterized by transmission electron microscopy and atomic force microscopy, demonstrating the uniform distribution of gold nanoparticles all over the surface. Our results open the possibility to control the functionalization on graphene in the construction of composite nanomaterials.A facile and simple approach for the covalent functionalization of surfactant wrapped graphene sheets is described. The approach involves functionalization of dispersible graphene sheets with various alkylazides and 11-azidoundecanoic acid proved the best azide for enhanced dispersibility. The functionalization was confirmed by infrared spectroscopy and scanning tunneling microscopy. The free carboxylic acidgroups can bind to gold nanoparticles, which were introduced as markers for the reactive sites. The interaction between gold nanoparticles and the graphene sheets was followed by UV-vis spectroscopy. The gold nanoparticle-graphene composite was characterized by transmission electron microscopy and atomic force microscopy, demonstrating the uniform distribution of gold nanoparticles all over the surface. Our results open the possibility to control the functionalization on graphene in the construction of composite nanomaterials. Electronic Supplementary Information (ESI) available: Synthesis and characterization details of dodecylazide

  18. Looking for Holes in Sterile Wrapping: How Accurate Are We?

    Science.gov (United States)

    Rashidifard, Christopher H; Mayassi, Hani A; Bush, Chelsea M; Opalacz, Brian M; Richardson, Mark W; Muccino, Paul M; DiPasquale, Thomas G

    2018-05-01

    Defects in sterile surgical wrapping are identified by the presence of holes through which light can be seen. However, it is unknown how reliably the human eye can detect these defects. The purpose of this study was to determine (1) how often holes in sterile packaging of various sizes could be detected; and (2) whether differences in lighting, experience level of the observer, or time spent inspecting the packaging were associated with improved likelihood of detection of holes in sterile packaging. Thirty participants (10 surgical technicians, 13 operating room nurses, seven orthopaedic surgery residents) inspected sterile sheets for perforations under ambient operating room (OR) lighting and then again with a standard powered OR lamp in addition to ambient lighting. There were no additional criteria for eligibility other than willingness to participate. Each sheet contained one of nine defect sizes with four sheets allocated to each defect size. Ten wraps were controls with no defects. Participants were allowed as much time as necessary for inspection. Holes ≥ 2.5 mm were detected more often than holes ≤ 2 mm (87% [832 of 960] versus 7% [82 of 1200]; odds ratio, 88.6 [95% confidence interval, 66.2-118.6]; p < 0.001). There was no difference in detection accuracy between OR lamp and ambient lightning nor experience level. There was no correlation between inspection time and detection accuracy. Defects ≤ 2 mm were not reliably detected with respect to lighting, time, or level of experience. Future research is warranted to determine defect sizes that are clinically meaningful. Level II, diagnostic study.

  19. Comparison of three different prehospital wrapping methods for preventing hypothermia - a crossover study in humans

    Directory of Open Access Journals (Sweden)

    Zakariassen Erik

    2011-06-01

    Full Text Available Abstract Background Accidental hypothermia increases mortality and morbidity in trauma patients. Various methods for insulating and wrapping hypothermic patients are used worldwide. The aim of this study was to compare the thermal insulating effects and comfort of bubble wrap, ambulance blankets / quilts, and Hibler's method, a low-cost method combining a plastic outer layer with an insulating layer. Methods Eight volunteers were dressed in moistened clothing, exposed to a cold and windy environment then wrapped using one of the three different insulation methods in random order on three different days. They were rested quietly on their back for 60 minutes in a cold climatic chamber. Skin temperature, rectal temperature, oxygen consumption were measured, and metabolic heat production was calculated. A questionnaire was used for a subjective evaluation of comfort, thermal sensation, and shivering. Results Skin temperature was significantly higher 15 minutes after wrapping using Hibler's method compared with wrapping with ambulance blankets / quilts or bubble wrap. There were no differences in core temperature between the three insulating methods. The subjects reported more shivering, they felt colder, were more uncomfortable, and had an increased heat production when using bubble wrap compared with the other two methods. Hibler's method was the volunteers preferred method for preventing hypothermia. Bubble wrap was the least effective insulating method, and seemed to require significantly higher heat production to compensate for increased heat loss. Conclusions This study demonstrated that a combination of vapour tight layer and an additional dry insulating layer (Hibler's method is the most efficient wrapping method to prevent heat loss, as shown by increased skin temperatures, lower metabolic rate and better thermal comfort. This should then be the method of choice when wrapping a wet patient at risk of developing hypothermia in prehospital

  20. Elevator frames two columns

    OpenAIRE

    Marín Jiménez, Juan Francisco

    2015-01-01

    This project aims to solve the problem of vertical transport of charges raised by a company with the standard UNE 58-132-91/6. The purpose of this project is the industrial design of a system of load handling by a bi-columned lifting device, tractioned by flat belts and steel cables from a transport level to a different level in order to connect two different assembly lines situated at different heights. The goal of this project is lifting a 780 Kg load at a 2.400 mm height....

  1. Column: Every Last Byte

    Directory of Open Access Journals (Sweden)

    Simson Garfinkel

    2011-06-01

    Full Text Available Inheritance powder is the name that was given to poisons, especially arsenic, that were commonly used in the 17th and early 18th centuries to hasten the death of the elderly. For most of the 17th century, arsenic was deadly but undetectable, making it nearly impossible to prove that someone had been poisoned. The first arsenic test produced a gas—hardly something that a scientist could show to a judge. Faced with a growing epidemic of poisonings, doctors and chemists spent decades searching for something better.(see PDF for full column

  2. Annular pulse column development studies

    International Nuclear Information System (INIS)

    Benedict, G.E.

    1980-01-01

    The capacity of critically safe cylindrical pulse columns limits the size of nuclear fuel solvent extraction plants because of the limited cross-sectional area of plutonium, U-235, or U-233 processing columns. Thus, there is a need to increase the cross-sectional area of these columns. This can be accomplished through the use of a column having an annular cross section. The preliminary testing of a pilot-plant-scale annular column has been completed and is reported herein. The column is made from 152.4-mm (6-in.) glass pipe sections with an 89-mm (3.5-in.) o.d. internal tube, giving an annular width of 32-mm (1.25-in.). Louver plates are used to swirl the column contents to prevent channeling of the phases. The data from this testing indicate that this approach can successfully provide larger-cross-section critically safe pulse columns. While the capacity is only 70% of that of a cylindrical column of similar cross section, the efficiency is almost identical to that of a cylindrical column. No evidence was seen of any non-uniform pulsing action from one side of the column to the other

  3. Column-to-column packing variation of disposable pre-packed columns for protein chromatography.

    Science.gov (United States)

    Schweiger, Susanne; Hinterberger, Stephan; Jungbauer, Alois

    2017-12-08

    In the biopharmaceutical industry, pre-packed columns are the standard for process development, but they must be qualified before use in experimental studies to confirm the required performance of the packed bed. Column qualification is commonly done by pulse response experiments and depends highly on the experimental testing conditions. Additionally, the peak analysis method, the variation in the 3D packing structure of the bed, and the measurement precision of the workstation influence the outcome of qualification runs. While a full body of literature on these factors is available for HPLC columns, no comparable studies exist for preparative columns for protein chromatography. We quantified the influence of these parameters for commercially available pre-packed and self-packed columns of disposable and non-disposable design. Pulse response experiments were performed on 105 preparative chromatography columns with volumes of 0.2-20ml. The analyte acetone was studied at six different superficial velocities (30, 60, 100, 150, 250 and 500cm/h). The column-to-column packing variation between disposable pre-packed columns of different diameter-length combinations varied by 10-15%, which was acceptable for the intended use. The column-to-column variation cannot be explained by the packing density, but is interpreted as a difference in particle arrangement in the column. Since it was possible to determine differences in the column-to-column performance, we concluded that the columns were well-packed. The measurement precision of the chromatography workstation was independent of the column volume and was in a range of±0.01ml for the first peak moment and±0.007 ml 2 for the second moment. The measurement precision must be considered for small columns in the range of 2ml or less. The efficiency of disposable pre-packed columns was equal or better than that of self-packed columns. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

  4. Complete BWR--EM LOCA analysis using the WRAP--EM system

    International Nuclear Information System (INIS)

    Beckmeyer, R.R.; Gregory, M.V.; Buckner, M.R.

    1979-01-01

    The Water Reactor Analysis Package, Evaluation Model (WRAP--EM), provides a complete analysis of postulated loss-of-coolant accidents (LOCA's) in light--water nuclear power reactors. The system is being developed at the Savannah River Laboratory (SRL) for use by the Nuclear Regulatory Commission (NRC) to interpret and evaluate reactor vendor, evaluation model (EM) analyses. The initial version of the WRAP--EM system for analysis of boiling water reactors (BWR's) is operational. To demonstrate the complete capability of the WRAP--BWR--EM system, a LOCA analysis has been performed for the Hope Creek Plant

  5. Finite-Element Modeling of a Damaged Pipeline Repaired Using the Wrap of a Composite Material

    Science.gov (United States)

    Lyapin, A. A.; Chebakov, M. I.; Dumitrescu, A.; Zecheru, G.

    2015-07-01

    The nonlinear static problem of FEM modeling of a damaged pipeline repaired by a composite material and subjected to internal pressure is considered. The calculation is carried out using plasticity theory for the pipeline material and considering the polymeric filler and the composite wrap. The level of stresses in various zones of the structure is analyzed. The most widespread alloy used for oil pipelines is selected as pipe material. The contribution of each component of the pipeline-filler-wrap system to the level of stresses is investigated. The effect of the number of composite wrap layers is estimated. The results obtained allow one to decrease the costs needed for producing test specimens.

  6. Gamma radiation, cold and four different wrappings to preserve ginger rhizomes, Zingiber officinallis Roscoe

    International Nuclear Information System (INIS)

    Queirol, Marco Antonio P.; Neto, J.T.; Arthur, Valter; Wiendl, Frederico M.; Villavicencio, Anna Lucia C.H.

    2002-01-01

    After irradiating with a single dose of 50 Gy, ginger rhizomes were dipped into paraffin for coating, wrapped in a plastic film of low-density polyethylene, on perforated or non-perforated polivinyl chloride film, and compared with non-wrapping and non-irradiation as the controls. After treatments the rhizomes were maintained refrigerated at 13 deg. C and 80% relative humidity. As a main result it could be observed that dipping into paraffin and wrapping with plastics resulted in smaller weight loss of the rhizomes

  7. Column: File Cabinet Forensics

    Directory of Open Access Journals (Sweden)

    Simson Garfinkel

    2011-12-01

    Full Text Available Researchers can spend their time reverse engineering, performing reverse analysis, or making substantive contributions to digital forensics science. Although work in all of these areas is important, it is the scientific breakthroughs that are the most critical for addressing the challenges that we face.Reverse Engineering is the traditional bread-and-butter of digital forensics research. Companies like Microsoft and Apple deliver computational artifacts (operating systems, applications and phones to the commercial market. These artifacts are bought and used by billions. Some have evil intent, and (if society is lucky, the computers end up in the hands of law enforcement. Unfortunately the original vendors rarely provide digital forensics tools that make their systems amenable to analysis by law enforcement. Hence the need for reverse engineering.(see PDF for full column

  8. Non-metallic structural wrap systems for pipe

    International Nuclear Information System (INIS)

    Walker, R.H.; Wesley Rowley, C.

    2001-01-01

    The use of thermoplastics and reinforcing fiber has been a long-term application of non-metallic material for structural applications. With the advent of specialized epoxies and carbon reinforcing fiber, structural strength approaching and surpassing steel has been used in a wide variety of applications, including nuclear power plants. One of those applications is a NSWS for pipe and other structural members. The NSWS is system of integrating epoxies with reinforcing fiber in a wrapped geometrical configuration. This paper specifically addresses the repair of degraded pipe in heat removal systems used in nuclear power plants, which is typically caused by corrosion, erosion, or abrasion. Loss of structural material leads to leaks, which can be arrested by a NSWS for the pipe. The technical aspects of using thermoplastics to structurally improve degraded pipe in nuclear power plants has been addressed in the ASME B and PV Code Case N-589. Using the fundamentals described in that Code Case, this paper shows how this technology can be extended to pipe repair from the outside. This NSWS has already been used extensively in non-nuclear applications and in one nuclear application. The cost to apply this NSWS is typically substantially less than replacing the pipe and may be technically superior to replacing the pipe. (author)

  9. 12 loops and triple wrapping in ABJM theory from integrability

    International Nuclear Information System (INIS)

    Anselmetti, Lorenzo; Bombardelli, Diego; Cavaglià, Andrea; Tateo, Roberto

    2015-01-01

    Adapting a method recently proposed by C. Marboe and D. Volin for N=4 super-Yang-Mills, we develop an algorithm for a systematic weak coupling expansion of the spectrum of anomalous dimensions in the sl(2)-like sector of planar N=6 super-Chern-Simons. The method relies on the Quantum Spectral Curve formulation of the problem and the expansion is written in terms of the interpolating function h(λ), with coefficients expressible as combinations of Euler-Zagier sums with alternating signs. We present explicit results up to 12 loops (six nontrivial orders) for various twist-1 and twist-2 operators, corresponding to triple and double wrapping terms, respectively, which are beyond the reach of the Asymptotic Bethe Ansatz as well as Lüscher’s corrections. The algorithm works for generic states in this sector and in principle can be used to compute arbitrary orders of the weak coupling expansion. For the simplest operator with L=1 and spin S=1, the Padé extrapolation of the 12-loop result nicely agrees with the available Thermodynamic Bethe Ansatz data in a relatively wide range of values of the coupling. A Mathematica notebook with a selection of results is attached.

  10. Program evaluation: Weatherization Residential Assistance Partnership (WRAP) Program

    Energy Technology Data Exchange (ETDEWEB)

    1991-12-01

    The Connecticut low income weatherization program was developed in response to a 1987 rate docket order from the Connecticut Department of Public Utility Control (DPUC) to Connecticut Light Power Co., an operating subsidiary of Northeast Utilities (NU). (Throughout this report, NU is referred to as the operator of the program.) This program, known as the Weatherization Residential Assistance Partnership, or WRAP, was configured utilizing input from a collaborative group of interested parties to the docket. It was agreed that this program would be put forth by the electric utility, but would not ignore oil and gas savings (thus, it was to be fuel- blind''). The allocated cost of conservation services for each fuel source, however, should be cost effective. It was to be offered to those utility customers at or below 200 percent of the federal poverty levels, and provide a wide array of energy saving measures directed toward heating, water heating and lighting. It was felt by the collaborative group that this program would raise the level of expenditures per participant for weatherization services provided by the state, and by linking to and revising the auditing process for weatherization, would lower the audit unit cost. The program plans ranged from the offering of low-cost heating, water heating and infiltration measures, increased insulation levels, carpentry and plumbing services, to furnace or burner replacement. The program was configured to allow for very comprehensive weatherization and heating system servicing.

  11. Chlorinated paraffins wrapping of carbon nanotubes: A theoretical investigation

    Science.gov (United States)

    Ding, Qiuyue; Ding, Ning; Chen, Xiangfeng; Wu, Chi-Man Lawrence

    2018-04-01

    How nanomaterials interact with pollutants is the central for understanding their environmental behavior and practical application. In this work, molecular dynamics (MD) and density functional theoretical (DFT) methods were used to investigated the influence of carbon chain length, degree of chlorination, chain configuration, and chirality of chlorinated paraffin (CP) and diameter of single-walled carbon nanotubes (SWNTs) on the interaction between CPs and SWNTs. The simulation results demonstrated that CP chain length and chlorination degree played considerably important roles in determining interaction strength between SWNTs and CPs. The interaction energies increased with increasing chain length and chlorination degree. The chirality of SWNT exerted negligible influence on the interaction energy between SWNTs and CPs. On the contrary, interaction energy increased with increasing radius of SWNTs due to the surface curvatures. This result was rationalized by considering the decrease in SWNT curvature with increasing radius, which resulted in plane-like CNT wall. The negligible influence of CP chain configurations was attributed to relative flexibility of CP carbon chains, which can wrap on tubes through conformational changes with low-energy barriers. MD results indicated that CPs could adsorb on SWNT surface rapidly in aqueous environment. Charge transfer and electronic density results indicated that the interaction between CPs and SWNTs was physisorption in nature. This work provides fundamental information regarding SWNTs as sorbents for CPs extraction and adsorptive removal from environmental water system.

  12. EFFECTS OF BLAST-FURNACE SLAG ON NATURAL POZZOLAN-BASED GEOPOLYMER CEMENT

    Directory of Open Access Journals (Sweden)

    MAHSHAD YAZDANIPOUR

    2011-03-01

    Full Text Available A number of geopolymer cement mixes were designed and produced by alkali-activation of a pumice-type natural pozzolan. Effects of blast-furnace slag on basic engineering properties of the mixes were studied. Different engineering properties of the mixes such as setting times and 28-day compressive strength were studied at different amounts of blast-furnace slag, sodium oxide content, and water-to-cement ratio. The mix comprising of 5 wt.% blast-furnace slag and 8 wt.% Na2O with a water-to-dry binder ratio of 0.30 exhibits the highest 28-day compressive strength, i.e. 36 MPa. Mixes containing 5 wt.% of ground granulated blast furnace slag showed the least efflorescence or best soundness. Laboratory techniques of X-ray diffractometry (XRD, fourier transform infrared spectroscopy (FTIR, and scanning electron microscopy (SEM were utilized for characterizing a number of mixes and studying their molecular and micro-structure. Investigations done by scanning electron microscopy confirm that smaller blast-furnace slag particles react totally while the larger ones react partially with alkaline activators and contribute to the formation of a composite microstructure.

  13. Comparative study of illite clay and illite-based geopolymer products

    International Nuclear Information System (INIS)

    Sperberga, I; Sedmale, G; Zeila, K; Ulme, D; Stinkulis, G

    2011-01-01

    Quaternary (Q-clay) clayey deposits are one of the dominating parts of mineral raw materials of the sedimentary cover at present area of Latvia. These clays can be characterised by illite content up to 75-80 %. Two ways for use of illite clays were studied: conventional and geopolymers method. Purpose of the second mentioned method was showing the influence of alkali (KOH) on the transformation of Q-clay/illite structure. Obtained products were investigated by IR-spectroscopy, DTA and XRD, pore size distribution was determined as well. Some ceramic properties and compressive strength were determined and compared. IR-spectrum showed the effect of alkali on the transformation of Q-clay/illite structure in three main absorption bands: 3620-3415 cm -1 which is related to the vibrational modes of adsorbed water between SiO 4 and AlO 6 layers; new stronger absorption bands at 1635 cm -1 and 1435 cm -1 indicate on the appearance of vibrations in Q-KOH and are related to the K-O-Si bonds; the most essential changes are vibrations at 850 cm -1 showing the changes in the coordination number of Al from 6 to 4 for Q-KOH. Investigations of the bulk density in dependence on temperature showed the small increase of bulk density for Q-clay while - the relatively remarkable decrease for Q-clay/KOH. Mentioned values correlate with the compressive strength of Q-clay and Q-KOH products.

  14. Mechanical and Microstructural Evaluations of Lightweight Aggregate Geopolymer Concrete before and after Exposed to Elevated Temperatures.

    Science.gov (United States)

    Abdulkareem, Omar A; Abdullah, Mohd Mustafa Al Bakri; Hussin, Kamarudin; Ismail, Khairul Nizar; Binhussain, Mohammed

    2013-10-09

    This paper presents the mechanical and microstructural characteristics of a lightweight aggregate geopolymer concrete (LWAGC) synthesized by the alkali-activation of a fly ash source (FA) before and after being exposed to elevated temperatures, ranging from 100 to 800 °C. The results show that the LWAGC unexposed to the elevated temperatures possesses a good strength-to-weight ratio compared with other LWAGCs available in the published literature. The unexposed LWAGC also shows an excellent strength development versus aging times, up to 365 days. For the exposed LWAGC to the elevated temperatures of 100 to 800 °C, the results illustrate that the concretes gain compressive strength after being exposed to elevated temperatures of 100, 200 and 300 °C. Afterward, the strength of the LWAGC started to deteriorate and decrease after being exposed to elevated temperatures of 400 °C, and up to 800 °C. Based on the mechanical strength results of the exposed LWAGCs to elevated temperatures of 100 °C to 800 °C, the relationship between the exposure temperature and the obtained residual compressive strength is statistically analyzed and achieved. In addition, the microstructure investigation of the unexposed LWAGC shows a good bonding between aggregate and mortar at the interface transition zone (ITZ). However, this bonding is subjected to deterioration as the LWAGC is exposed to elevated temperatures of 400, 600 and 800 °C by increasing the microcrack content and swelling of the unreacted silicates.

  15. Effect of Alkaline Solution with Varying Mix Proportion on Geopolymer Mortar

    Science.gov (United States)

    Karuppuchamy, K.; Ananthkumar, M.; Raghavapriya, S. M.

    2018-02-01

    Cement production is attributed by emission of carbon dioxide which causes severe environmental impacts. This has led to the invention of special construction materials which can replace cement. On the other hand, these construction materials (like Fly ash, Metakaolin) also need to be inexpensive and should possess all the characteristics of cementitious materials. In this project, the effect of geopolymerization on the properties of the end product were studied with varying distillation of NaOH solution (10M, 12M and 15M) for different mix proportion (1:1, 1:2 and 1:3). Curing was done for 1 day at a temperature of 60°C and 80°C respectively. The densities, compressive strength, alkalinity, co-efficient of absorption were determined. As a result, the experiments showed the effect of factors such as mix proportion, curing temperature and curing day on the physical and mechanical properties such as mix proportion of the geopolymer concrete. Results of NaOH concentration of 12M concentration cured for 24 hours at 80°C and 60°C showed better mechanical performance than the rest of the concentrations.

  16. Compressive strength and microstructural characteristics of class C fly ash geopolymer

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Xiaolu; Shi, Huisheng; Dick, Warren A [Key Laboratory of Advanced Civil Engineering Materials (Tongji University), Shanghai (China)

    2010-02-15

    Geopolymers prepared from a class C fly ash (CFA) and a mixed alkali activator of sodium hydroxide and sodium silicate solution were investigated. A high compressive strength was obtained when the modulus of the activator viz., molar ratio of SiO{sub 2}/Na{sub 2}O was 1.5, and the proper content of this activator as evaluated by the mass proportion of Na{sub 2}O to CFA was 10%. The compressive strength of these samples was 63.4 MPa when they were cured at 75{sup o}C for 8 h followed by curing at 23{sup o}C for 28 d. In FTIR spectroscopy, the main peaks at 1036 and 1400 cm{sup -1} have been attributed to asymmetric stretching of Al-O/Si-O bonds, while those at 747 cm{sup -1} are due to the Si-O-Si/Si-O-Al bending band. The main geopolymeric gel and calcium silicate hydrate (C-S-H) gel co-exist and bond some remaining unreacted CFA spheres as observed in XRD and SEM-EXDA. The presence of gismondine (zeolite) was also observed in the XRD pattern.

  17. Stress State Analysis and Failure Mechanisms of Masonry Columns Reinforced with FRP under Concentric Compressive Load

    Directory of Open Access Journals (Sweden)

    Jiří Witzany

    2016-04-01

    Full Text Available The strengthening and stabilization of damaged compressed masonry columns with composites based on fabrics of high-strength fibers and epoxy resin, or polymer-modified cement mixtures, belongs to novel, partially non-invasive and reversible progressive methods. The stabilizing and reinforcing effect of these fabrics significantly applies to masonry structures under concentric compressive loading whose failure mechanism is characterized by the appearance and development of vertical tensile cracks accompanied by an increase in horizontal masonry strain. During the appearance of micro and hairline cracks (10−3 to 10−1 mm, the effect of non-pre-stressed wrapping composite is very small. The favorable effect of passive wrapping is only intensively manifested after the appearance of cracks (10−1 mm and bigger at higher loading levels. In the case of “optimum” reinforcement of a masonry column, the experimental research showed an increase in vertical displacements δy (up to 247%, horizontal displacements δx (up to 742% and ultimate load-bearing capacity (up to 136% compared to the values reached in unreinforced masonry columns. In the case of masonry structures in which no intensive “bed joint filler–masonry unit” interaction occurs, e.g., in regular coursed masonry with little differences in the mechanical characteristics of masonry units and the binder, the reinforcing effect of the fabric applies only partially.

  18. Compact electron beam focusing column

    Science.gov (United States)

    Persaud, Arun; Leung, Ka-Ngo; Reijonen, Jani

    2001-12-01

    A novel design for an electron beam focusing column has been developed at LBNL. The design is based on a low-energy spread multicusp plasma source which is used as a cathode for electron beam production. The focusing column is 10 mm in length. The electron beam is focused by means of electrostatic fields. The column is designed for a maximum voltage of 50 kV. Simulations of the electron trajectories have been performed by using the 2D simulation code IGUN and EGUN. The electron temperature has also been incorporated into the simulations. The electron beam simulations, column design and fabrication will be discussed in this presentation.

  19. Enhancing the Supercapacitor Performance of Graphene/MnO 2 Nanostructured Electrodes by Conductive Wrapping

    KAUST Repository

    Yu, Guihua; Hu, Liangbing; Liu, Nian; Wang, Huiliang; Vosgueritchian, Michael; Yang, Yuan; Cui, Yi; Bao, Zhenan

    2011-01-01

    suffer from poor electronic and ionic conductivities, resulting in their limited performance in power density and cycling. Here we developed a "conductive wrapping" method to greatly improve the supercapacitor performance of graphene/MnO2-based

  20. Waste Receiving and Processing (WRAP) Facility Final Safety Analysis Report (FSAR)

    International Nuclear Information System (INIS)

    TOMASZEWSKI, T.A.

    2000-01-01

    The Waste Receiving and Processing Facility (WRAP), 2336W Building, on the Hanford Site is designed to receive, confirm, repackage, certify, treat, store, and ship contact-handled transuranic and low-level radioactive waste from past and present U.S. Department of Energy activities. The WRAP facility is comprised of three buildings: 2336W, the main processing facility (also referred to generically as WRAP); 2740W, an administrative support building; and 2620W, a maintenance support building. The support buildings are subject to the normal hazards associated with industrial buildings (no radiological materials are handled) and are not part of this analysis except as they are impacted by operations in the processing building, 2336W. WRAP is designed to provide safer, more efficient methods of handling the waste than currently exist on the Hanford Site and contributes to the achievement of as low as reasonably achievable goals for Hanford Site waste management

  1. Wrapping interactions and the genus expansion of the 2-point function of composite operators

    International Nuclear Information System (INIS)

    Sieg, Christoph; Torrielli, Alessandro

    2005-01-01

    We perform a systematic analysis of wrapping interactions for a general class of theories with color degrees of freedom, including N=4 SYM. Wrapping interactions arise in the genus expansion of the 2-point function of composite operators as finite size effects that start to appear at a certain order in the coupling constant at which the range of the interaction is equal to the length of the operators. We analyze in detail the relevant genus expansions, and introduce a strategy to single out the wrapping contributions, based on adding spectator fields. We use a toy model to demonstrate our procedure, performing all computations explicitly. Although completely general, our treatment should be particularly useful for applications to the recent problem of wrapping contributions in some checks of the AdS/CFT correspondence

  2. Coaxial Thermoplastic Elastomer-Wrapped Carbon Nanotube Fibers for Deformable and Wearable Strain Sensors

    KAUST Repository

    Zhou, Jian; Xu, Xuezhu; Xin, Yangyang; Lubineau, Gilles

    2018-01-01

    performances in these design requirements. Here, achieving highly stretchable and sensitive strain sensors by using a coaxial structure, prepared via coaxial wet spinning of thermoplastic elastomer-wrapped carbon nanotube fibers, is proposed. The sensors attain

  3. Waste Receiving and Processing (WRAP) Facility Final Safety Analysis Report (FSAR)

    Energy Technology Data Exchange (ETDEWEB)

    TOMASZEWSKI, T.A.

    2000-04-25

    The Waste Receiving and Processing Facility (WRAP), 2336W Building, on the Hanford Site is designed to receive, confirm, repackage, certify, treat, store, and ship contact-handled transuranic and low-level radioactive waste from past and present U.S. Department of Energy activities. The WRAP facility is comprised of three buildings: 2336W, the main processing facility (also referred to generically as WRAP); 2740W, an administrative support building; and 2620W, a maintenance support building. The support buildings are subject to the normal hazards associated with industrial buildings (no radiological materials are handled) and are not part of this analysis except as they are impacted by operations in the processing building, 2336W. WRAP is designed to provide safer, more efficient methods of handling the waste than currently exist on the Hanford Site and contributes to the achievement of as low as reasonably achievable goals for Hanford Site waste management.

  4. Suffocation caused by plastic wrap covering the face combined with nitrous oxide inhalation

    DEFF Research Database (Denmark)

    Leth, Peter Mygind; Astrup, Birgitte Schmidt

    2017-01-01

    Suicide using a combination of a plastic bag over the head and inhalation of a non-irritating gas, such as helium, argon or nitrogen, has been reported in the literature. Here an unusual suicide method in a 17-year old man by suffocation from covering the face with household plastic wrap, combined....... The deceased was a 17-year old man who was found with the nose and mouth closed with a piece of kitchen plastic wrap. The plastic wrap had been removed prior to autopsy. Autopsy findings were suggestive of asphyxia, but were otherwise negative. Nitrous oxide was detected in the brain and lung tissue...... with headspace-gas chromatography-mass spectrometry (headspace-GCMS). The cause of death was assumed to be suffocation caused by plastic wrap covering the face, combined with nitrous oxide inhalation. Suicide was suspected because of a history of depression for several months. Nitrous oxide, also known...

  5. The setting time of a clay-slag geopolymer matrix: the influence of blast-furnace-slag addition and the mixing method

    Czech Academy of Sciences Publication Activity Database

    Perná, Ivana; Hanzlíček, Tomáš

    112, Part 1, JAN 20 (2016), s. 1150-1155 ISSN 0959-6526 Institutional support: RVO:67985891 Keywords : blast-furnace slag * geopolymer * setting time * mixing method * solidification * recycling Subject RIV: DM - Solid Waste and Recycling Impact factor: 5.715, year: 2016

  6. Simultaneous removal of Ni(II), As(III), and Sb(III) from spiked mine effluent with metakaolin and blast-furnace-slag geopolymers.

    Science.gov (United States)

    Luukkonen, Tero; Runtti, Hanna; Niskanen, Mikko; Tolonen, Emma-Tuulia; Sarkkinen, Minna; Kemppainen, Kimmo; Rämö, Jaakko; Lassi, Ulla

    2016-01-15

    The mining industry is a major contributor of various toxic metals and metalloids to the aquatic environment. Efficient and economical water treatment methods are therefore of paramount importance. The application of natural or low-cost sorbents has attracted a great deal of interest due to the simplicity of its process and its potential effectiveness. Geopolymers represent an emerging group of sorbents. In this study, blast-furnace-slag and metakaolin geopolymers and their raw materials were tested for simultaneous removal of Ni(II), As(III) and Sb(III) from spiked mine effluent. Blast-furnace-slag geopolymer proved to be the most efficient of the studied materials: the experimental maximum sorption capacities for Ni, As and, Sb were 3.74 mg/g, 0.52 mg/g, and 0.34 mg/g, respectively. Although the capacities were relatively low due to the difficult water matrix, 90-100% removal of Ni, As, and Sb was achieved when the dose of sorbent was increased appropriately. Removal kinetics fitted well with the pseudo-second-order model. Our results indicate that geopolymer technology could offer a simple and effective way to turn blast-furnace slag to an effective sorbent with a specific utilization prospect in the mining industry. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Determination of trace and minor elements in Mexican cigarette wrapping paper

    International Nuclear Information System (INIS)

    Iskander, F.Y.; Manzanares-Acuna, E.

    1999-01-01

    The concentration of 14 elements in cigarette wrapping papers used in manufacturing 21 different Mexican cigarette brands was measured using instrumental thermal neutron activation analysis. These elements are As, Ba, Ce, Co, Cr, Cs, Fe, K, Na, Rb, Sb, Sc, Sr, Th and Zn. The concentration of the elements was compared with the reported concentration in similar studies for elemental content in Pakistani, American, Chinese, Egyptian, Jordanian and Iranian cigarette wrapping papers. (author)

  8. Waste Receiving and Processing (WRAP) Facility Weight Scale Analysis Fairbanks Weight Scale Evaluation Results

    International Nuclear Information System (INIS)

    JOHNSON, M.D.

    1999-01-01

    Fairbanks Weight Scales are used at the Waste Receiving and Processing (WRAP) facility to determine the weight of waste drums as they are received, processed, and shipped. Due to recent problems, discovered during calibration, the WRAP Engineering Department has completed this document which outlines both the investigation of the infeed conveyor scale failure in September of 1999 and recommendations for calibration procedure modifications designed to correct deficiencies in the current procedures

  9. 279 Watt Metal-Wrap-Through module using industrial processes

    Energy Technology Data Exchange (ETDEWEB)

    Guillevin, N.; Heurtault, B.; Geerligs, L.J.; Anker, J.; Van Aken, B.B.; Bennett, I.J.; Jansen, M.J.; Berkeveld, L.D.; Weeber, A.W.; Bultman, J.H. [ECN Solar Energy, PO Box 1, 1755 ZG Petten (Netherlands); Wenchao, Zhao; Jianming, Wang; Ziqian, Wang; Yingle, Chen; Yanlong, Shen; Zhiyan, Hu; Gaofei, Li; Jianhui, Chen; Bo, Yu; Shuquan, Tian; Jingfeng, Xiong [Yingli Solar, 3399 Chaoyang North Street, Baoding (China)

    2012-09-15

    This paper describes results of metal wrap through (MWT) cells produced from n-type Czochralski silicon wafers, and modules produced from those cells. The use of n-type silicon as base material allows for high efficiencies: for front emitter contacted industrial cells, efficiencies up to 20% have been reported. MWT cells allow even higher cell efficiency due to reduced front metal coverage, and additionally full back-contacting of the MWT cells in a module results in reduced cell to module (CTM) fill factor losses. MWT cells were produced by industrial process technologies. The efficiency of the MWT cells reproducibly exceeds the efficiency of front contact cells based on the same technology by about 0.2-0.3%, and routes for further improvement are analyzed. 60-cell modules were produced from both types of cells (MWT and H-pattern front emitter). In a direct module performance comparison, the MWT module, based on integrated backfoil, produced 3% higher power output than the comparable tabbed front emitter contact module. CTM current differences arise from the higher packing density, and in this experiment from a lower reflectance of the backfoil, in MWT modules. CTM FF differences are related to resistive losses in copper circuitry on the backfoil versus tabs. The CTM FF loss of the MWT module was reduced by 2.2%abs compared to the tabbed front emitter contact module. Finally, simple process optimizations were tested to improve the n-type MWT cell and module efficiency. A module made using MWT cells of 19.6% average efficiency resulted in a power output of 279W. The cell and module results are analyzed and routes for improvements are discussed.

  10. Graphene-wrapped ZnO nanospheres as a photocatalyst for high performance photocatalysis

    International Nuclear Information System (INIS)

    Chen, Da; Wang, Dongfang; Ge, Qisheng; Ping, Guangxing; Fan, Meiqiang; Qin, Laishun; Bai, Liqun; Lv, Chunju; Shu, Kangying

    2015-01-01

    In this work, graphene-wrapped ZnO nanospheres (ZnO–graphene nanocomposites) were prepared by a simple facile lyophilization method, followed by thermal treatment process. ZnO nanospheres with the size of about 100–400 nm, composed of numerous nanocrystals with hexagonal wurtzite structure, were well separated from each other and wrapped with transparent graphene sheets. Compared to ZnO nanospheres, the ZnO–graphene nanocomposites showed a significant enhancement in the photodegradation of methylene blue. This enhanced photocatalytic activity could be attributed to their favorable dye-adsorption affinity and increased optical absorption as well as the efficient charge transfer of the photogenerated electrons in the conduction band of ZnO to graphene. Thus, this work could provide a facile and low-cost method for the development of graphene-based nanocomposites with promising applications in photocatalysis, solar energy conversion, sensing, and so on. - Highlights: • Graphene-wrapped ZnO nanospheres were prepared by a facile lyophilization method. • ZnO nanospheres were separated from each other and wrapped with 2D graphene sheets. • Graphene-wrapped ZnO nanospheres exhibited superior photocatalytic activities. • The photocatalytic mechanisms of graphene-wrapped ZnO nanospheres were discussed

  11. Graphene-wrapped ZnO nanospheres as a photocatalyst for high performance photocatalysis

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Da, E-mail: dchen_80@hotmail.com [College of Materials Science & Engineering, China Jiliang University, Hangzhou 310018 (China); Wang, Dongfang; Ge, Qisheng; Ping, Guangxing [College of Materials Science & Engineering, China Jiliang University, Hangzhou 310018 (China); Fan, Meiqiang, E-mail: fanmeiqiang@126.com [College of Materials Science & Engineering, China Jiliang University, Hangzhou 310018 (China); Qin, Laishun [College of Materials Science & Engineering, China Jiliang University, Hangzhou 310018 (China); Bai, Liqun [School of Sciences, Zhejiang Agriculture and Forestry University, Hangzhou 311300 (China); Lv, Chunju; Shu, Kangying [College of Materials Science & Engineering, China Jiliang University, Hangzhou 310018 (China)

    2015-01-01

    In this work, graphene-wrapped ZnO nanospheres (ZnO–graphene nanocomposites) were prepared by a simple facile lyophilization method, followed by thermal treatment process. ZnO nanospheres with the size of about 100–400 nm, composed of numerous nanocrystals with hexagonal wurtzite structure, were well separated from each other and wrapped with transparent graphene sheets. Compared to ZnO nanospheres, the ZnO–graphene nanocomposites showed a significant enhancement in the photodegradation of methylene blue. This enhanced photocatalytic activity could be attributed to their favorable dye-adsorption affinity and increased optical absorption as well as the efficient charge transfer of the photogenerated electrons in the conduction band of ZnO to graphene. Thus, this work could provide a facile and low-cost method for the development of graphene-based nanocomposites with promising applications in photocatalysis, solar energy conversion, sensing, and so on. - Highlights: • Graphene-wrapped ZnO nanospheres were prepared by a facile lyophilization method. • ZnO nanospheres were separated from each other and wrapped with 2D graphene sheets. • Graphene-wrapped ZnO nanospheres exhibited superior photocatalytic activities. • The photocatalytic mechanisms of graphene-wrapped ZnO nanospheres were discussed.

  12. Safety barriers and lighting columns.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1972-01-01

    Problems arising from the sitting of lighting columns on the central reserve are reviewed, and remedial measures such as break-away lighting supports and installation of safety fences on the central reserve on both sides of the lighting columns are examined.

  13. Influence of ties on the behavior of short reinforced concrete columns strengthened by external CFRP

    Directory of Open Access Journals (Sweden)

    Sarsam Kaiss

    2018-01-01

    Full Text Available An experimental study was carried out to investigate the behavior of normal strength reinforce concret (RC circular short column strengthned with “carbon fiber reinforced polymer (CFRP sheets”. Three series comprising totally of (15 specimens loaded until failure under concentric compresion load. Strengthening was varied by changing the number of CFRP strips, spacing and wrapping methods. The findings of this research can be summarized as follows: for the columns without CFRP, the influence of the tie spacing was significant: compared with 130 mm tie spacing, dropping the spacing to 100 mm and 70 mm increased the load carrying capacity by 18% and 26%, respectively. The columns with less internal confinement (lesser amount of ties were strengthened more significantly by the CFRP than the ones with greater amount of internal ties. As an example of the varying effectiveness of the fully wrapped CFRP, the column with ties at 130 mm was strengthened by 90% with the CFRP. In contrast, the ones with 70 mm spaced ties only increased in strength with CFRP by 66%. Compared with the control specimen (no CFRP, the same amount of CFRP when used as hoop strips led to more strengthening than using CFRP as a spiral strip- the former led to nearly 9% more strengthening than the latter in the case of 130 mm spaced internal steel ties. In the case of 100 mm internal steel ties, the difference (between the hoops & spiral CFRP strengthening is close to 4%. In contrast, there is no difference between the two methods of strengthening in the heavily tied columns (70 mm tied spacing.

  14. Mush Column Magma Chambers

    Science.gov (United States)

    Marsh, B. D.

    2002-12-01

    Magma chambers are a necessary concept in understanding the chemical and physical evolution of magma. The concept may well be similar to a transfer function in circuit or time series analysis. It does what needs to be done to transform source magma into eruptible magma. In gravity and geodetic interpretations the causative body is (usually of necessity) geometrically simple and of limited vertical extent; it is clearly difficult to `see' through the uppermost manifestation of the concentrated magma. The presence of plutons in the upper crust has reinforced the view that magma chambers are large pots of magma, but as in the physical representation of a transfer function, actual magma chambers are clearly distinct from virtual magma chambers. Two key features to understanding magmatic systems are that they are vertically integrated over large distances (e.g., 30-100 km), and that all local magmatic processes are controlled by solidification fronts. Heat transfer considerations show that any viable volcanic system must be supported by a vertically extensive plumbing system. Field and geophysical studies point to a common theme of an interconnected stack of sill-like structures extending to great depth. This is a magmatic Mush Column. The large-scale (10s of km) structure resembles the vertical structure inferred at large volcanic centers like Hawaii (e.g., Ryan et al.), and the fine scale (10s to 100s of m) structure is exemplified by ophiolites and deeply eroded sill complexes like the Ferrar dolerites of the McMurdo Dry Valleys, Antarctica. The local length scales of the sill reservoirs and interconnecting conduits produce a rich spectrum of crystallization environments with distinct solidification time scales. Extensive horizontal and vertical mushy walls provide conditions conducive to specific processes of differentiation from solidification front instability to sidewall porous flow and wall rock slumping. The size, strength, and time series of eruptive behavior

  15. Influence of Molarity and Chemical Composition on the Development of Compressive Strength in POFA Based Geopolymer Mortar

    Directory of Open Access Journals (Sweden)

    S. M. Alamgir Kabir

    2015-01-01

    Full Text Available The investigation concerns the use of the optimum mix proportion of two locally available pozzolanic waste materials, namely, ground granulated blast furnace slag (GGBS and palm oil fuel ash (POFA, together with metakaolin (MK as binders. In addition, another local waste material, manufactured sand (M-sand, was used as a replacement for conventional sand in the development of green geopolymer mortar. Twenty-four mortar mixtures were designed with varying binder contents and alkaline activators. The oven dry curing was also kept consistent for all the mix proportions at a temperature of 65°C for 24 hours. The highest 28-day compressive strength of about 48 MPa was obtained for the mortar containing 20% of MK, 35% of GGBS, and 45% of POFA. The increment of MK beyond 20% leads to reduction of the compressive strength. The GGBS replacement beyond 35% also reduced the compressive strength. The entire specimen achieved average 80% of the 28-day strength at the age of 3 days. The density decreased with the increase of POFA percentage. The finding of this research by using the combination of MK, GGBS, and POFA as binders to wholly replace conventional ordinary Portland cement would lead to alternate eco-friendly geopolymer matrix.

  16. Effect of silica fume on the fresh and hardened properties of fly ash-based self-compacting geopolymer concrete

    Science.gov (United States)

    Memon, Fareed Ahmed; Nuruddin, Muhd Fadhil; Shafiq, Nasir

    2013-02-01

    The effect of silica fume on the fresh and hardened properties of fly ash-based self-compacting geopolymer concrete (SCGC) was investigated in this paper. The work focused on the concrete mixes with a fixed water-to-geopolymer solid (W/Gs) ratio of 0.33 by mass and a constant total binder content of 400 kg/m3. The mass fractions of silica fume that replaced fly ash in this research were 0wt%, 5wt%, 10wt%, and 15wt%. The workability-related fresh properties of SCGC were assessed through slump flow, V-funnel, and L-box test methods. Hardened concrete tests were limited to compressive, splitting tensile and flexural strengths, all of which were measured at the age of 1, 7, and 28 d after 48-h oven curing. The results indicate that the addition of silica fume as a partial replacement of fly ash results in the loss of workability; nevertheless, the mechanical properties of hardened SCGC are significantly improved by incorporating silica fume, especially up to 10wt%. Applying this percentage of silica fume results in 4.3% reduction in the slump flow; however, it increases the compressive strength by 6.9%, tensile strength by 12.8% and flexural strength by 11.5%.

  17. Experimental Study on Rise Husk Ash & Fly Ash Based Geo-Polymer Concrete Using M-Sand

    Science.gov (United States)

    Nanda Kishore, G.; Gayathri, B.

    2017-08-01

    Serious environmental problems by means of increasing the production of Ordinary Portland cement (OPC), which is conventionally used as the primary binder to produce cement concrete. An attempt has been made to reduce the use of ordinary Portland cement in cement concrete. There is no standard mix design of geo-polymer concrete, an effort has been made to know the physical, chemical properties and optimum mix of geo-polymer concrete mix design. Concrete cubes of 100 x 100 x 100 mm were prepared and cured under steam curing for about 24 hours at temperature range of 40°C to 60°C. Fly ash is replaced partially with rice husk ash at percentage of 10%, 15% and 25%. Sodium hydroxide and sodium silicate are of used as alkaline activators with 5 Molar and 10 Molar NaOH solutions. Natural sand is replaced with manufacture sand. Test results were compared with controlled concrete mix of grade M30. The results shows that as the percentage of rice husk ash and water content increases, compressive strength will be decreases and as molarity of the alkaline solution increases, strength will be increases.

  18. Secondary Waste Form Screening Test Results—THOR® Fluidized Bed Steam Reforming Product in a Geopolymer Matrix

    Energy Technology Data Exchange (ETDEWEB)

    Pires, Richard P.; Westsik, Joseph H.; Serne, R. Jeffrey; Mattigod, Shas V.; Golovich, Elizabeth C.; Valenta, Michelle M.; Parker, Kent E.

    2011-07-14

    Screening tests are being conducted to evaluate waste forms for immobilizing secondary liquid wastes from the Hanford Tank Waste Treatment and Immobilization Plant (WTP). Plans are underway to add a stabilization treatment unit to the Effluent Treatment Facility to provide the needed capacity for treating these wastes from WTP. The current baseline is to use a Cast Stone cementitious waste form to solidify the wastes. Through a literature survey, DuraLith alkali-aluminosilicate geopolymer, fluidized-bed steam reformation (FBSR) granular product encapsulated in a geopolymer matrix, and a Ceramicrete phosphate-bonded ceramic were identified both as candidate waste forms and alternatives to the baseline. These waste forms have been shown to meet waste disposal acceptance criteria, including compressive strength and universal treatment standards for Resource Conservation and Recovery Act (RCRA) metals (as measured by the toxicity characteristic leaching procedure [TCLP]). Thus, these non-cementitious waste forms should also be acceptable for land disposal. Information is needed on all four waste forms with respect to their capability to minimize the release of technetium. Technetium is a radionuclide predicted to be in the secondary liquid wastes in small quantities, but the Integrated Disposal Facility (IDF) risk assessment analyses show that technetium, even at low mass, produces the largest contribution to the estimated IDF disposal impacts to groundwater.

  19. Determination of Volatile Organic Compounds (VOCs from Wrapping Films and Wrapped PDO Italian Cheeses by Using HS-SPME and GC/MS

    Directory of Open Access Journals (Sweden)

    Sara Panseri

    2014-06-01

    Full Text Available Nowadays food wrapping assures attractive presentation and simplifies self-service shopping. Polyvinylchloride (PVC- and polyethylene (PE-based cling-films are widely used worldwide for wrapping cheeses. For this purpose, films used in retail possess suitable technical properties such as clinginess and unrolling capacity, that are achieved by using specific plasticizers during their manufacturing process. In the present study, the main VOCs of three cling-films (either PVC-based or PE-based for retail use were characterized by means of Solid-Phase Micro-Extraction and GC/MS. In addition, the effects of cling film type and contact time on the migration of VOCs from the films to four different PDO Italian cheeses during cold storage under light or dark were also investigated. Among the VOCs isolated from cling-films, PVC released 2-ethylhexanol and triacetin. These compounds can likely be considered as a “non-intentionally added substance”. These same compounds were also detected in cheeses wrapped in PVC films with the highest concentration found after 20 days storage. The PE cling-film was shown to possess a simpler VOC profile, lacking some molecules peculiar to PVC films. The same conclusions can be drawn for cheeses wrapped in the PE cling-film. Other VOCs found in wrapped cheeses were likely to have been released either by direct transfer from the materials used for the manufacture of cling-films or from contamination of the films. Overall, HS-SPME is shown to be a rapid and solvent free technique to screen the VOCs profile of cling-films, and to detect VOCs migration from cling-films to cheese under real retail storage conditions.

  20. Column-Oriented Database Systems (Tutorial)

    NARCIS (Netherlands)

    D. Abadi; P.A. Boncz (Peter); S. Harizopoulos

    2009-01-01

    textabstractColumn-oriented database systems (column-stores) have attracted a lot of attention in the past few years. Column-stores, in a nutshell, store each database table column separately, with attribute values belonging to the same column stored contiguously, compressed, and densely packed, as

  1. The Influence of a Padded Hand Wrap on Punching Force in Elite and Untrained Punchers

    Directory of Open Access Journals (Sweden)

    Andrew J. Galpin

    2015-10-01

    Full Text Available Punching is integral to success in combat sports, making it a frequent activity during practice/training. Improving safety of this activity benefits both the athlete and training partners. This study was designed to 1 test the precision and reliability of a commercially available striking device and 2 assess the influence of a novel padded hand wrap on punching force in elite and untrained punchers. Fourteen male professional boxers and mixed martial artists (PRO; age=29.2±5.6y; height=180.3±9.0cm; mass=87.1±17.9kg, winning %=73.8±13.8%, number of victories via knockout/technical knockout=35.6± 21.9% and 24 untrained male punchers (UNT; 27.6±6.9y, 177.6±18.3cm, 84.3±16.9kg wore a standardized boxing glove and performed 20 maximal punches (4 sets of 5 into a device designed to measure punching force. All participants performed, in a counterbalanced order, 2 sets of 5 with a standardized hand wrap and 2 sets of 5 with the same wrap plus an additional 1.2cm thick cylinder 4g foam-like pad (WRAP placed over the knuckles. PRO produced significantly more punching force than UNT, regardless of condition. Punching force was lower by 12.6% (p<0.05 for PRO and 8.9% (p<0.05 for UNT with WRAP (compared to no WRAP. These findings suggest WRAP significantly reduces punching force, which may be important for long-term safety of the puncher’s hand and/or the person receiving the strike. Keywords: safety, punching, striking, hitting, combat, pad

  2. Water Column Sonar Data Collection

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The collection and analysis of water column sonar data is a relatively new avenue of research into the marine environment. Primary uses include assessing biological...

  3. Quality changes of 'Sanguinello' oranges wrapped with different plastic films under simulated marketing conditions.

    Science.gov (United States)

    D'Aquino, S; Malinconico, M; Avella, M; Di Lorenzo, M L; Mura; Palma, A

    2013-01-01

    Chemical and eating quality of citrus fruit changes slowly after harvest, and quality alteration is mainly due to shrinkage, loss of firmness, excessive weight loss and decay rather than a reduction of nutritional value and taste features. Film wrapping may be a suitable means to reduce transpiration and preserve market quality provided film permeability to gases does not lead to: 1) a reduction of in-package O2 partial pressure at a point that would induce anaerobic respiration; 2) an increase of CO2 concentration to toxic levels. This experiment was carried out to study quality changes of 'Sanguinello' oranges treated or not treated with 500 mg/L imazalil (IMZ) and wrapped with continuous, macro- or micro-perforated polyolefinic films. Wrapped and no-wrapped fruit were stored at 20 degrees C and 60% RH for 20 or 30 days. In-package gas composition of the macro-perforated film showed no significant difference compared to air composition, while in-package partial pressure of CO2 and O2 ranged between 4 (continuous film) and 9.8 kPa (micro-perforated films), and 14.8 (continuous film) and 5 kPa (micro-perforated films), respectively. After 30 days of storage weight loss in fruit wrapped with the macro-perforated film was (4.3%) slightly lowerthan un-packed fruit (5%), while in all other packages weight loss never exceeded 0.7%.Quality changes were quite stable over storage in all treatments, although slight but significantly lower levels of total soluble solids and ascorbic acid were detected in micro-perforated films with the lowest degree of perforation. However, the sensory analysis denoted a remarkable decrease of firmness in un-wrapped or wrapped fruit with macro-perforated film, while a moderate build-up of off-flavour, which reduced the eating quality, developed in micro-perforated films. Decay ranged between 6 and 12% in not treated fruit, with the lowest incidence detected in un-wrapped fruit, whereas differences among the different films were not

  4. The metal wrap through solar cell. Developement and characterisation; Die metal wrap through Solarzelle. Entwicklung und Charakterisierung

    Energy Technology Data Exchange (ETDEWEB)

    Clement, Florian

    2009-03-20

    This work focuses on the development and the optimization of the metal wrap through (MWT) solar cell. Primary goal of this work has been the development of an appropriate process flow for MWT solar cells, which generates only insignificant extra costs compared to the conventional process flow, however, achieves a significant efficiency increase for MWT cells compared to conventionally processed cells. The latter was one of the main challenges of this work. For this purpose MWT solar cells have been studied and characterized in detail. Loss mechanisms have been detected and improvements evaluated as well as transferred to the cell process. Furthermore, the assembling process for MWT solar cells in the module has been optimized focusing on less series resistance losses. A comparison with the conventional module assembling process is presented. A process flow similar to the one for the conventional process has been developed for MWT solar cells. Merely two additional laser process steps for hole drilling and rear contact isolation as well as one screen printing step for the through connection turn out to be necessary. It is shown that the additional screen printing process can be omitted without significant efficiency losses, if the through connection and solder pad metallization is done in a single process step. Furthermore, a fast and reliable through connection process has been developed and characterized in detail. Moreover, a gauge mounting block for MWT solar cells has been constructed, analyzed and calibrated for current-voltage-characteristic measurements. With multi crystalline MWT silicon solar cells an efficiency gain up to 0.5% absolute has been achieved compared to conventionally processed solar cells - thereby reaching a maximum cell efficiency of more than 16.7%. Due to a novel MWT module technology developed in this work the efficiency compared to the conventional technology could be improved further by another 0.3% absolute. The primary loss

  5. Three-dimensional flow phenomena in a wire-wrapped 37-pin fuel bundle for SFR

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Jae Ho; Yoo, Jin; Lee, Kwi Lim; Ha, Kwi Seok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-08-15

    Three-dimensional flow phenomena in a wire-wrapped 37-pin fuel assembly mock-up of a Japanese loop-type sodium-cooled fast reactor, Monju, were investigated with a numerical analysis using a general-purpose commercial computational fluid dynamics code, CFX. Complicated and vortical flow phenomena in the wire-wrapped 37-pin fuel assembly were captured by a Reynolds-averaged Navier-Stokes flow simulation using a shear stress transport turbulence model. The main purpose of the current study is to understand the three-dimensional complex flow phenomena in a wire-wrapped fuel assembly to support the license issue for the core design. Computational fluid dynamics results show good agreement with friction factor correlation models. The secondary flow in the corner and edge subchannels is much stronger than that in an interior subchannel. The axial velocity averaged in the corner and edge subchannels is higher than that averaged in the interior subchannels. Three-dimensional multiscale vortex structures start to be formed by an interaction between secondary flows around each wire-wrapped pin. Behavior of the large-scale vortex structures in the corner and edge subchannels is closely related to the relative position between the hexagonal duct wall and the helically wrapped wire spacer. The small-scale vortex is axially developed in the interior subchannels. Furthermore, a driving force on each wire spacer surface is closely related to the relative position between the hexagonal duct wall and the wire spacer.

  6. Reduction in Wound Complications After Total Ankle Arthroplasty Using a Compression Wrap Protocol.

    Science.gov (United States)

    Schipper, Oliver N; Hsu, Andrew R; Haddad, Steven L

    2015-12-01

    The purpose of this study was to evaluate the clinical differences in wound complications after total ankle arthroplasty (TAA) between a cohort of patients that received a compression wrap protocol and a historical control group treated with cast immobilization. Patient charts and postoperative wound pictures were reviewed for 42 patients who underwent a compression wrap protocol and 50 patients who underwent circumferential casting after primary TAA from 2008 to 2013. A blinded reviewer graded each wound using a novel postoperative wound classification system, and recorded whether the wound was completely healed by or after 3 months. A second blinded review was performed to determine intraobserver reliability. Mean patient age was 55 years (range, 24-80) and all patients had at least 6-month follow-up. There were significantly more total wound complications (P = .02) and mild wound complications (P = .02) in the casted group compared to the compression wrap group. There were no significant differences in the number of moderate and severe complications between each group. A significantly higher proportion of TAA incisions took longer than 3 months to heal in the casted group (P = .02). Based on our clinical experience with postoperative wound care after TAA, use of a compression wrap protocol was safe and effective at reducing wound-related complications, and well tolerated by patients. Further prospective, randomized clinical trials are warranted to evaluate the utility and cost-effectiveness of a compression wrap protocol after TAA. © The Author(s) 2015.

  7. Cooking loss, tenderness, and sensory evaluation of chicken meat roasted after wrapping with edible films.

    Science.gov (United States)

    Küçüközet, Ahmet Oktay; Uslu, Mustafa Kemal

    2018-01-01

    In this study, edible films were produced from sodium caseinate and a sodium caseinate-starch mixture and with or without oleoresins (cumin and oregano oleoresin mixture). Chicken meat was wrapped in the respective films, stored at 4 ℃ for four days, and roasted at 200 ℃ for 30 min. The cooking loss, color changes, instrumental tenderness (shear force and energy) were measured. In addition, sensory evaluation was performed. All films effectively reduced cooking loss from chicken meat. The sodium caseinate-starch-based films were the most successful in preventing cooking loss. The average shear force and shear energy values of the wrapped samples were about 40% and 30% less than those of control samples, respectively. In sensory evaluation, chicken meat roasted after wrapping with the films was considered more tender and delicious than the control. Particularly, chicken meat wrapped with the films containing oleoresin mixture was assessed as the most delicious among the samples. It was shown that the cooking quality of the chicken meat could be significantly improved by pre-wrapping the meat with edible films.

  8. Quality changes of sea bass slices wrapped with gelatin film incorporated with lemongrass essential oil.

    Science.gov (United States)

    Ahmad, Mehraj; Benjakul, Soottawat; Sumpavapol, Punnanee; Nirmal, Nilesh Prakash

    2012-04-16

    Microbiological, chemical and physical changes of sea bass slices wrapped with gelatin film incorporated with 25% (w/w) lemongrass essential oil (LEO) during storage of 12 days at 4 °C were investigated. Sea bass slices wrapped with LEO film had the retarded growth of lactic acid bacteria (LAB), psychrophilic bacteria and spoilage microorganisms including H₂S-producing bacteria and Enterobacteriaceae throughout storage of 12 days in comparison with the control and those wrapped with gelatin film without LEO (G film) (P<0.05). Lowered changes of colour, K value, total volatile base nitrogen (TVB) and TBARS value were also found in LEO film wrapped samples, compared with those wrapped with G film and control, respectively. Therefore, the incorporation of LEO into gelatin film could enhance the antimicrobial and antioxidative properties of the film, thereby maintaining the qualities and extending the shelf-life of the sea bass slices stored at refrigerated temperature. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Nonlinear behaviors of FRP-wrapped tall trees subjected to high wind loads

    Science.gov (United States)

    Kang, J.; Yi, Z. Z.; Choi, S. G.

    2017-12-01

    This study investigated the mechanical stability of historical tall trees wrapped with fiber-reinforced polymer (FRP) laminates using finite element (FE) analysis. High wind loads are considered as external loading conditions as they are one of the major threats on the structural stability of tall old trees. There have been several traditional practices to enhance the stability of tall trees exposed to high windstorms such as tree supporters and anchorages. They, however, have been sometimes causing negative effects with their misuses as the application guidelines for those methods were not adequately studied or documented. Furthermore, the oldest known trees in the country should be protected from the damage of external surface as well as ruin of the landscape. The objective of this study was to evaluate the structural effects of FRP wraps applied to tall trees subjected to high wind loads. The anisotropic material properties of wood and FRP laminates were considered in the analysis in addition to geometrically nonlinear behaviors. This study revealed that FRP wrapping for tall trees could effectively reduce the deflections and maximum stresses of trees, which results in the enhanced stability of tall trees. The optimum geometry and thicknesses of FRP wraps proposed in this study would provide fundemental guidelines for designing and constructing the application of innovative FRP wraps on tall trees, which are structurally unstable or should be preserved nationally and historically.

  10. LIQUID-LIQUID EXTRACTION COLUMNS

    Science.gov (United States)

    Thornton, J.D.

    1957-12-31

    This patent relates to liquid-liquid extraction columns having a means for pulsing the liquid in the column to give it an oscillatory up and down movement, and consists of a packed column, an inlet pipe for the dispersed liquid phase and an outlet pipe for the continuous liquid phase located in the direct communication with the liquid in the lower part of said column, an inlet pipe for the continuous liquid phase and an outlet pipe for the dispersed liquid phase located in direct communication with the liquid in the upper part of said column, a tube having one end communicating with liquid in the lower part of said column and having its upper end located above the level of said outlet pipe for the dispersed phase, and a piston and cylinder connected to the upper end of said tube for applying a pulsating pneumatic pressure to the surface of the liquid in said tube so that said surface rises and falls in said tube.

  11. Column-Oriented Database Systems (Tutorial)

    OpenAIRE

    Abadi, D.; Boncz, Peter; Harizopoulos, S.

    2009-01-01

    textabstractColumn-oriented database systems (column-stores) have attracted a lot of attention in the past few years. Column-stores, in a nutshell, store each database table column separately, with attribute values belonging to the same column stored contiguously, compressed, and densely packed, as opposed to traditional database systems that store entire records (rows) one after the other. Reading a subset of a table’s columns becomes faster, at the potential expense of excessive disk-head s...

  12. Combined Transverse Steel-External FRP Confinement Model for Rectangular Reinforced Concrete Columns

    Directory of Open Access Journals (Sweden)

    Ahmed Al-Rahmani

    2016-02-01

    Full Text Available Recently, the need to increase the strength of reinforced concrete members has become a subject that civil engineers are interested in tackling. Of the many proposed solutions, fiber-reinforced polymer (FRP materials have attracted attention due to their superior properties, such as high strength-to-weight ratio, high energy absorption and excellent corrosion resistance. FRP wrapping of concrete columns is done to enhance the ultimate strength due to the confinement effect, which is normally induced by steel ties. The existence of the two confinement systems changes the nature of the problem, thus necessitating specialized nonlinear analysis to obtain the column’s ultimate capacity. Existing research focused on a single confinement system. Furthermore, very limited research on rectangular sections was found in the literature. In this work, a model to estimate the combined behavior of the two systems in rectangular columns is proposed. The calculation of the effective lateral pressure is based on the Lam and Teng model and the Mander model for FRP wraps and steel ties, respectively. The model then generates stress-strain diagrams for both the concrete core and the cover. The model was developed for the analysis in extreme load events, where all possible contributions to the column’s ultimate capacity should be accounted for without any margin of safety. The model was validated against experiments, and the results obtained showed good agreement with almost all of the available experimental data.

  13. Waste Receiving and Processing (WRAP) Facility Public Address System Review Findings

    International Nuclear Information System (INIS)

    HUMPHRYS, K.L.

    1999-01-01

    Public address system operation at the Waste Receiving and Processing (WRAP) facility was reviewed. The review was based on an Operational Readiness Review finding that public address performance was not adequate in parts of the WRAP facility. Several improvements were made to the WRAP Public Address (PA) system to correct the deficiencies noted. Speaker gain and position was optimized. A speech processor was installed to boost intelligibility in high noise areas. Additional speakers were added to improve coverage in the work areas. The results of this evaluation indicate that further PA system enhancements are not warranted. Additional speakers cannot compensate for the high background sound and high reverberation levels found in the work areas. Recommendations to improve PA system intelligibility include minor speaker adjustments, enhanced PA announcement techniques, and the use of sound reduction and abatement techniques where economically feasible

  14. On the effectiveness of XML schema validation for countering XML signature wrapping attacks

    DEFF Research Database (Denmark)

    Jensen, Meiko; Meyer, Christopher; Somorovsky, Juraj

    2011-01-01

    In the context of security of Web Services, the XML Signature Wrapping attack technique has lately received increasing attention. Following a broad range of real-world exploits, general interest in applicable countermeasures rises. However, few approaches for countering these attacks have been...... investigated closely enough to make any claims about their effectiveness. In this paper, we analyze the effectiveness of the specific countermeasure of XML Schema validation in terms of fending Signature Wrapping attacks. We investigate the problems of XML Schema validation for Web Services messages......, and discuss the approach of Schema Hardening, a technique for strengthening XML Schema declarations. We conclude that XML Schema validation with a hardened XML Schema is capable of fending XML Signature Wrapping attacks, but bears some pitfalls and disadvantages as well....

  15. Waste Analysis Plan for the Waste Receiving and Processing (WRAP) Facility

    International Nuclear Information System (INIS)

    TRINER, G.C.

    1999-01-01

    The purpose of this waste analysis plan (WAP) is to document the waste acceptance process, sampling methodologies, analytical techniques, and overall processes that are undertaken for dangerous, mixed, and radioactive waste accepted for confirmation, nondestructive examination (NDE) and nondestructive assay (NDA), repackaging, certification, and/or storage at the Waste Receiving and Processing Facility (WRAP). Mixed and/or radioactive waste is treated at WRAP. WRAP is located in the 200 West Area of the Hanford Facility, Richland, Washington. Because dangerous waste does not include source, special nuclear, and by-product material components of mixed waste, radionuclides are not within the scope of this documentation. The information on radionuclides is provided only for general knowledge

  16. Quality Assistance Objectives for Nondestructive Assay at the Waste Receiving and Processing (WRAP) Facility

    International Nuclear Information System (INIS)

    CANTALOUB, M.G.

    2000-01-01

    The Waste Receiving and Processing (WRAP) facility, located on the Word Site in southeast Washington, is a key link in the certification of transuranic (TRU) waste for shipment to the Waste Isolation Pilot Plant (WIPP). Waste characterization is one of the vital functions performed at WRAP, and nondestructive assay (NDA) measurements of TRU waste containers is one of two required methods used for waste characterization. The Waste Acceptance Criteria for the Waste Isolation Pilot Plant, DOE/WIPP-069 (WIPP-WAC) delineates the quality assurance objectives which have been established for NDA measurement systems. Sites must demonstrate that the quality assurance objectives can be achieved for each radioassay system over the applicable ranges of measurement. This report summarizes the validation of the WRAP NDA systems against the radioassay quality assurance objectives or QAOs. A brief description of the each test and significant conclusions are included. Variables that may have affected test outcomes and system response are also addressed

  17. Radiotracer Imaging of Sediment Columns

    Science.gov (United States)

    Moses, W. W.; O'Neil, J. P.; Boutchko, R.; Nico, P. S.; Druhan, J. L.; Vandehey, N. T.

    2010-12-01

    Nuclear medical PET and SPECT cameras routinely image radioactivity concentration of gamma ray emitting isotopes (PET - 511 keV; SPECT - 75-300 keV). We have used nuclear medical imaging technology to study contaminant transport in sediment columns. Specifically, we use Tc-99m (T1/2 = 6 h, Eγ = 140 keV) and a SPECT camera to image the bacteria mediated reduction of pertechnetate, [Tc(VII)O4]- + Fe(II) → Tc(IV)O2 + Fe(III). A 45 mL bolus of Tc-99m (32 mCi) labeled sodium pertechnetate was infused into a column (35cm x 10cm Ø) containing uranium-contaminated subsurface sediment from the Rifle, CO site. A flow rate of 1.25 ml/min of artificial groundwater was maintained in the column. Using a GE Millennium VG camera, we imaged the column for 12 hours, acquiring 44 frames. As the microbes in the sediment were inactive, we expected most of the iron to be Fe(III). The images were consistent with this hypothesis, and the Tc-99m pertechnetate acted like a conservative tracer. Virtually no binding of the Tc-99m was observed, and while the bolus of activity propagated fairly uniformly through the column, some inhomogeneity attributed to sediment packing was observed. We expect that after augmentation by acetate, the bacteria will metabolically reduce Fe(III) to Fe(II), leading to significant Tc-99m binding. Imaging sediment columns using nuclear medicine techniques has many attractive features. Trace quantities of the radiolabeled compounds are used (micro- to nano- molar) and the half-lives of many of these tracers are short (Image of Tc-99m distribution in a column containing Rifle sediment at four times.

  18. Performance evaluation of a rectifier column using gamma column scanning

    Directory of Open Access Journals (Sweden)

    Aquino Denis D.

    2017-12-01

    Full Text Available Rectifier columns are considered to be a critical component in petroleum refineries and petrochemical processing installations as they are able to affect the overall performance of these facilities. It is deemed necessary to monitor the operational conditions of such vessels to optimize processes and prevent anomalies which could pose undesired consequences on product quality that might lead to huge financial losses. A rectifier column was subjected to gamma scanning using a 10-mCi Co-60 source and a 2-inch-long detector in tandem. Several scans were performed to gather information on the operating conditions of the column under different sets of operating parameters. The scan profiles revealed unexpected decreases in the radiation intensity at vapour levels between trays 2 and 3, and between trays 4 and 5. Flooding also occurred during several scans which could be attributed to parametric settings.

  19. Upon local blockage formations in LMFBR fuel rod bundles with wire-wrapped spacers

    International Nuclear Information System (INIS)

    Minden, C. v.; Schultheiss, G.F.

    1982-01-01

    A theoretical and experimental study, to improve understanding of local particle depositions in a wire-wrapped LMFBR fuel bundle, has been performed. Theoretical considerations show, that a preferentially axial process of particle depositions occurs. The experiments confirm this and clarify that the blockages arise near the particle source and settle at the spatially arranged minimum gaps in the bundle. The results suggest that, considering flow reduction, cooling and DND-detection, such fuel particle blockages are less dangerous. With reference to these safety-relevant factors, wire-wrapped LMFBR fuel bundles seem to gain advantages compared to the grid design. (orig.) [de

  20. Develoment of pressure drop calculation modules for a wire-wrapped LMR subassembly

    International Nuclear Information System (INIS)

    Kim, Young Gyun; Lim, Hyun Jin; Kim, Won Seok; Kim, Young Il

    2000-06-01

    Pressure drop calculation modules for a wire-wrapped LMR subassembly was been developed. This report summarizes present information on pressure drop calculation modules for inlet hole, lower part and upper part of a wire-wrapped LMR subassembly which was developed using simple formulas of sudden expansion and sudden contraction. A case calculation study was done using design data of a KALIMER driver fuel subassembly. And the total pressure drop in the driver fuel subassembly, except for the bundle part, was calculated as 0.13 MPa, which is in the reasonable pressure drop range. The developed modules will be integrated in the total subassembly pressure drop calculation code with further improvements

  1. Investigating the effect of multiple layers of insulation with a bubble wrap experiment

    Science.gov (United States)

    Eggers, Dolores; Ruiz, Michael J.

    2018-03-01

    We provide a fun, inexpensive laboratory experiment for students to investigate the effects of multiple layers of insulation and observe diminishing values for additional layers using bubble wrap. This experiment provides an opportunity for students to learn about heat transfer through conduction using readily available materials. A water-ice pack is placed on top of five layers of bubble wrap. The temperature is taken between each layer periodically for at least 15 min. Students determine asymptotic temperatures for varying layers. This experiment also suggests a real world application.

  2. Transparently wrap-gated semiconductor nanowire arrays for studies of gate-controlled photoluminescence

    Energy Technology Data Exchange (ETDEWEB)

    Nylund, Gustav; Storm, Kristian; Torstensson, Henrik; Wallentin, Jesper; Borgström, Magnus T.; Hessman, Dan; Samuelson, Lars [Solid State Physics, Nanometer Structure Consortium, Lund University, Box 118, S-221 00 Lund (Sweden)

    2013-12-04

    We present a technique to measure gate-controlled photoluminescence (PL) on arrays of semiconductor nanowire (NW) capacitors using a transparent film of Indium-Tin-Oxide (ITO) wrapping around the nanowires as the gate electrode. By tuning the wrap-gate voltage, it is possible to increase the PL peak intensity of an array of undoped InP NWs by more than an order of magnitude. The fine structure of the PL spectrum reveals three subpeaks whose relative peak intensities change with gate voltage. We interpret this as gate-controlled state-filling of luminescing quantum dot segments formed by zincblende stacking faults in the mainly wurtzite NW crystal structure.

  3. Post column derivatisation analyses review. Is post-column derivatisation incompatible with modern HPLC columns?

    Science.gov (United States)

    Jones, Andrew; Pravadali-Cekic, Sercan; Dennis, Gary R; Shalliker, R Andrew

    2015-08-19

    Post Column derivatisation (PCD) coupled with high performance liquid chromatography or ultra-high performance liquid chromatography is a powerful tool in the modern analytical laboratory, or at least it should be. One drawback with PCD techniques is the extra post-column dead volume due to reaction coils used to enable adequate reaction time and the mixing of reagents which causes peak broadening, hence a loss of separation power. This loss of efficiency is counter-productive to modern HPLC technologies, -such as UHPLC. We reviewed 87 PCD methods published from 2009 to 2014. We restricted our review to methods published between 2009 and 2014, because we were interested in the uptake of PCD methods in UHPLC environments. Our review focused on a range of system parameters including: column dimensions, stationary phase and particle size, as well as the geometry of the reaction loop. The most commonly used column in the methods investigated was not in fact a modern UHPLC version with sub-2-micron, (or even sub-3-micron) particles, but rather, work-house columns, such as, 250 × 4.6 mm i.d. columns packed with 5 μm C18 particles. Reaction loops were varied, even within the same type of analysis, but the majority of methods employed loop systems with volumes greater than 500 μL. A second part of this review illustrated briefly the effect of dead volume on column performance. The experiment evaluated the change in resolution and separation efficiency of some weak to moderately retained solutes on a 250 × 4.6 mm i.d. column packed with 5 μm particles. The data showed that reaction loops beyond 100 μL resulted in a very serious loss of performance. Our study concluded that practitioners of PCD methods largely avoid the use of UHPLC-type column formats, so yes, very much, PCD is incompatible with the modern HPLC column. Copyright © 2015. Published by Elsevier B.V.

  4. Investigation of the sample preparation and curing treatment effects on mechanical properties and bioactivity of silica rich metakaolin geopolymer

    International Nuclear Information System (INIS)

    Catauro, M.; Bollino, F.; Papale, F.; Lamanna, G.

    2014-01-01

    In many biomedical applications both the biological and mechanical behaviours of implants are of relevant interest; in the orthopaedic field, for example, favourable bioactivity and biocompatibility capabilities are necessary, but at the same time the mechanical characteristics of the implants must be such as to allow one to support the body weight. In the present work, the authors have examined the application of geopolymers with composition H 24 AlK 7 Si 31 O 79 and ratio Si/Al = 31 to be used in biomedical field, considering two different preparation methods: one of the activators (KOH) has been added as pellets in the potassium silicate solution, in the other as a water solution with 8 M concentration. Moreover, a different water content was used and only some of the synthesized samples were heat treated. The chemical and microstructural characterizations of those materials have been carried out by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). Subsequently, the effects of the adopted preparation on the mechanical and biological properties have been studied: compressive strength tests have demonstrated that more fragile specimens were obtained when KOH was added as a solution. The bioactivity was successfully evaluated with the soaking of the samples in a simulated body fluid (SBF) for 3 weeks. The formation of a layer of hydroxyapatite on the surface of the materials has been shown both by SEM micrographs and EDS analyses. - Highlights: • Rich metakaolin geopolymer activated with KOH/K 2 SiO 3 and thermal treatment • Mechanical and bioactivity test to evaluate consolidation and bone bonding ability • Order of addition of reactants and thermal treatment influence mechanical properties

  5. Investigation of the sample preparation and curing treatment effects on mechanical properties and bioactivity of silica rich metakaolin geopolymer

    Energy Technology Data Exchange (ETDEWEB)

    Catauro, M., E-mail: michelina.catauro@unina2.it; Bollino, F.; Papale, F.; Lamanna, G.

    2014-03-01

    In many biomedical applications both the biological and mechanical behaviours of implants are of relevant interest; in the orthopaedic field, for example, favourable bioactivity and biocompatibility capabilities are necessary, but at the same time the mechanical characteristics of the implants must be such as to allow one to support the body weight. In the present work, the authors have examined the application of geopolymers with composition H{sub 24}AlK{sub 7}Si{sub 31}O{sub 79} and ratio Si/Al = 31 to be used in biomedical field, considering two different preparation methods: one of the activators (KOH) has been added as pellets in the potassium silicate solution, in the other as a water solution with 8 M concentration. Moreover, a different water content was used and only some of the synthesized samples were heat treated. The chemical and microstructural characterizations of those materials have been carried out by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). Subsequently, the effects of the adopted preparation on the mechanical and biological properties have been studied: compressive strength tests have demonstrated that more fragile specimens were obtained when KOH was added as a solution. The bioactivity was successfully evaluated with the soaking of the samples in a simulated body fluid (SBF) for 3 weeks. The formation of a layer of hydroxyapatite on the surface of the materials has been shown both by SEM micrographs and EDS analyses. - Highlights: • Rich metakaolin geopolymer activated with KOH/K{sub 2}SiO{sub 3} and thermal treatment • Mechanical and bioactivity test to evaluate consolidation and bone bonding ability • Order of addition of reactants and thermal treatment influence mechanical properties.

  6. Surface decoration of polyimide fiber with carbon nanotubes and its application for mechanical enhancement of phosphoric acid-based geopolymers

    Science.gov (United States)

    Yang, Tao; Han, Enlin; Wang, Xiaodong; Wu, Dezhen

    2017-09-01

    A new methodology to decorate the surface of polyimide (PI) fiber with carbon nanotubes (CNTs) has been developed in this study. This surface decoration was carried out through a surface alkali treatment, a carboxylation modification, surface functionalization with acyl chloride groups and then with amino groups, and a surface graft of CNTs onto PI fiber. Fourier-transform infrared and X-ray photoelectron spectroscopic characterizations confirmed that CNTs were chemically grafted onto the surface of PI fiber, and scanning electron microscopic observation demonstrated the fiber surface was uniformly and densely covered with CNTs. The surface energy and wettability of PI fiber were improved in the presence of CNTs on the fiber surface, which made a contribution to enhance the interfacial adhesion of PI fiber with other inorganic matrices when used as a reinforcing fiber. The application of CNTs-decorated PI fiber for the reinforcement of phosphoric acid-based geopolymers was investigated, and the results indicated that the geopolymeric composites gained a noticeable reinforcement. Compared to unreinforced geopolymer, the geopolymeric composites achieved a remarkable increase in compressive strength by 120% and in flexural strength by 283%. Fractography investigation demonstrated that the interaction adhesion between the fibers and matrix was enhanced due to the surface decoration of PI fiber with CNTs, which contributed to an improvement in fracture-energy dissipation by fiber pullout and fiber debonding from the matrix. As a result, a significant reinforcement effect on geopolymeric composites was achieved through a fiber-bridging mechanism. This study provided an effective methodology to improve the interracial bonding force for PI fiber and also proves a highly efficient application of CNTs-decorated PI fiber for the mechanical enhancement of geopolymeric composites.

  7. Microencapsulated phase change materials for enhancing the thermal performance of Portland cement concrete and geopolymer concrete for passive building applications

    International Nuclear Information System (INIS)

    Cao, Vinh Duy; Pilehvar, Shima; Salas-Bringas, Carlos; Szczotok, Anna M.; Rodriguez, Juan F.; Carmona, Manuel; Al-Manasir, Nodar; Kjøniksen, Anna-Lena

    2017-01-01

    Highlights: • Microencapsulated phase change materials give high energy storage capacity concrete. • Microcapsule addition increases the porosity of concrete. • Thermal and mechanical properties are linked to the enhanced concrete porosity. • Agglomerated microcapsules have strong impact on the concrete properties. • Microcapsules caused geopolymer to become more energy efficient than Portland cement. - Abstract: Concretes with a high thermal energy storage capacity were fabricated by mixing microencapsulated phase change materials (MPCM) into Portland cement concrete (PCC) and geopolymer concrete (GPC). The effect of MPCM on thermal performance and compressive strength of PCC and GPC were investigated. It was found that the replacement of sand by MPCM resulted in lower thermal conductivity and higher thermal energy storage, while the specific heat capacity of concrete remained practically stable when the phase change material (PCM) was in the liquid or solid phase. Furthermore, the thermal conductivity of GPC as function of MPCM concentration was reduced at a higher rate than that of PCC. The power consumption needed to stabilize a simulated indoor temperature of 23 °C was reduced after the addition of MPCM. GPC exhibited better energy saving properties than PCC at the same conditions. A significant loss in compressive strength was observed due to the addition of MPCM to concrete. However, the compressive strength still satisfies the mechanical European regulation (EN 206-1, compressive strength class C20/25) for concrete applications. Finally, MPCM-concrete provided a good thermal stability after subjecting the samples to 100 thermal cycles at high heating/cooling rates.

  8. NOx retention in scrubbing column

    International Nuclear Information System (INIS)

    Nakazone, A.K.; Costa, R.E.; Lobao, A.S.T.; Matsuda, H.T.; Araujo, B.F.

    1988-07-01

    During the UO 2 dissolution in nitric acid, some different species of NO x are released. The off gas can either be refluxed to the dissolver or be released and retained on special columns. The final composition of the solution is the main parameter to take in account. A process for nitrous gases retention using scubber columns containing H 2 O or diluted HNO 3 is presented. Chemiluminescence measurement was employed to NO x evalution before and after scrubbing. Gas flow, temperature, residence time are the main parameters considered in this paper. For the dissolution of 100g UO 2 in 8M nitric acid, a 6NL/h O 2 flow was the best condition for the NO/NO 2 oxidation with maximum adsorption in the scrubber columns. (author) [pt

  9. Fly-Ash-Based Geopolymers: How the Addition of Recycled Glass or Red Mud Waste Influences the Structural and Mechanical Properties

    Czech Academy of Sciences Publication Activity Database

    Toniolo, N.; Taveri, Gianmarco; Hurle, K.; Roether, J. A.; Ercole, P.; Dlouhý, Ivo; Boccaccini, A. R.

    2017-01-01

    Roč. 8, č. 3 (2017), s. 411-420 ISSN 2190-9385 EU Projects: European Commission(XE) 642557 - CoACH Institutional support: RVO:68081723 Keywords : Geopolymers * Fly ash * Red mud * Waste glass Subject RIV: JH - Ceramic s, Fire-Resistant Materials and Glass OBOR OECD: Ceramic s Impact factor: 1.220, year: 2016 https://www. ceramic -science.com/articles/all-articles.html?article_id=100566

  10. Why do males of the spider Pisaura mirabilis wrap their nuptial gifts in silk: Female preference or male control?

    DEFF Research Database (Denmark)

    Andersen, Tina; Bollerup, Kristine; Toft, Søren

    2008-01-01

    Males of the spider Pisaura mirabilis present a nuptial prey gift to the female during courtship as a mating effort. The gift is usually round and wrapped in white silk. It was suggested that the wrapped gift functions as a sensory trap by mimicking the female's eggsac implying that males exploit...

  11. The evolution of strength and crystalline phases for alkali-activated ground blast furnace slag and fly ash-based geopolymers

    KAUST Repository

    Oh, Jae Eun

    2010-02-01

    The increase in strength and evolution of crystalline phases in inorganic polymer cement, made by the alkali activation of slag, Class C and Class F fly ashes, was followed using compressive strength test and synchrotron X-ray diffraction. In order to increase the crystallinity of the product the reactions were carried out at 80 °C. We found that hydrotalcite formed in both the alkali-activated slag cements and the fly ash-based geopolymers. Hydroxycancrinite, one member of the ABC-6 family of zeolites, was found only in the fly ash geopolymers. Assuming that the predominantly amorphous geopolymer formed under ambient conditions relates to the crystalline phases found when the mixture is cured at high temperature, we propose that the structure of this zeolitic precursor formed in Na-based high alkaline environment can be regarded as a disordered form of the basic building unit of the ABC-6 group of zeolites which includes poly-types such as hydroxycancrinite, hydroxysodalite and chabazite-Na. © 2009 Elsevier Ltd.

  12. The evolution of strength and crystalline phases for alkali-activated ground blast furnace slag and fly ash-based geopolymers

    International Nuclear Information System (INIS)

    Oh, Jae Eun; Monteiro, Paulo J.M.; Jun, Ssang Sun; Choi, Sejin; Clark, Simon M.

    2010-01-01

    The increase in strength and evolution of crystalline phases in inorganic polymer cement, made by the alkali activation of slag, Class C and Class F fly ashes, was followed using compressive strength test and synchrotron X-ray diffraction. In order to increase the crystallinity of the product the reactions were carried out at 80 deg. C. We found that hydrotalcite formed in both the alkali-activated slag cements and the fly ash-based geopolymers. Hydroxycancrinite, one member of the ABC-6 family of zeolites, was found only in the fly ash geopolymers. Assuming that the predominantly amorphous geopolymer formed under ambient conditions relates to the crystalline phases found when the mixture is cured at high temperature, we propose that the structure of this zeolitic precursor formed in Na-based high alkaline environment can be regarded as a disordered form of the basic building unit of the ABC-6 group of zeolites which includes poly-types such as hydroxycancrinite, hydroxysodalite and chabazite-Na.

  13. CSER-98-002: Criticality analysis for the storage of special nuclear material sources and standards in the WRAP facility

    International Nuclear Information System (INIS)

    GOLDBERG, H.J.

    1999-01-01

    The Waste Receiving and Processing (WRAP) Facility will store uranium and transuranic (TRU) sources and standards for certification that WRAP meets the requirements of the Quality Assurance Program Plan (QAPP) for the Waste Isolation Pilot Plant (WIPP). In addition, WRAP must meet internal requirements for testing and validation of measuring instruments for nondestructive assay (NDA). In order to be certified for WIPP, WRAP will participate in the NDA Performance Demonstration Program (PDP). This program is a blind test of the NDA capabilities for TRU waste. It is intended to ensure that the NDA capabilities of this facility satisfy the requirements of the quality assurance program plan for the WIPP. The PDP standards have been provided by the Los Alamos National Laboratory (LANL) for this program. These standards will be used in the WRAP facility

  14. Decoration of multi-walled carbon nanotubes by polymer wrapping and its application in MWCNT/polyethylene composites.

    Science.gov (United States)

    Hsiao, An-En; Tsai, Shu-Ya; Hsu, Mei-Wen; Chang, Shinn-Jen

    2012-05-06

    We dispersed the non-covalent functionalization of multi-walled carbon nanotubes (CNTs) with a polymer dispersant and obtained a powder of polymer-wrapped CNTs. The UV-vis absorption spectrum was used to investigate the optimal weight ratio of the CNTs and polymer dispersant. The powder of polymer-wrapped CNTs had improved the drawbacks of CNTs of being lightweight and difficult to process, and it can re-disperse in a solvent. Then, we blended the polymer-wrapped CNTs and polyethylene (PE) by melt-mixing and produced a conductive masterbatch and CNT/PE composites. The polymer-wrapped CNTs showed lower surface resistivity in composites than the raw CNTs. The scanning electron microscopy images also showed that the polymer-wrapped CNTs can disperse well in composites than the raw CNTs.

  15. Input parameters to codes which analyze LMFBR wire-wrapped bundles

    International Nuclear Information System (INIS)

    Hawley, J.T.; Chan, Y.N.; Todreas, N.E.

    1980-12-01

    This report provides a current summary of recommended values of key input parameters required by ENERGY code analysis of LMFBR wire wrapped bundles. This data is based on the interpretation of experimental results from the MIT and other available laboratory programs

  16. Test Specifications and the Design of the Wire Wrapped 37-Pin Fuel Assembly for Hydrodynamic Experiments

    International Nuclear Information System (INIS)

    Chang, S. K.; Euh, D. J.; Bae, H.; Lee, H. Y.; Choi, S. R.

    2013-01-01

    Most influencing parameters on uncertainties and sensitivities of the CFD analyses are the friction coefficient and the mixing coefficient. The friction coefficient is related to the flow distribution in reactor sub-channels. The mixing coefficient is defined with the cross flow between neighboring sub-channels. The eventual purpose of the thermal hydraulic design considering these parameters is to guarantee the fuel cladding integrity as the design limit parameter. At the moment, the experimental program is being undertaken to quantify these friction and mixing parameters which characterize the flow distribution in sub-channels, and the wire wrapped 37-pin rod assembly and its hexagonal test rig have been designed and fabricated. The quantified thermal hydraulic experimental data from this program are utilized primarily to estimate the accuracy of the safety analysis codes and their thermal hydraulic model. A wire wrapped 37 pin fuel assembly has been designed for the measurements of the flow distribution, where the measurements are utilized to quantify the friction coefficient and the mixing coefficient. The test rig of the wire wrapped 37 pin fuel assembly has been fabricated considering the geometric and flow dynamic similarities. It comprises four components i. e., the upper plenum, the fuel housing, the lower plenum, and the wire wrapped 37 pin fuel assembly. At further works, the quantified friction and mixing coefficients through the experiments are going to be utilized for insuring the reliability of the CFD analysis results

  17. Influence of wraps over efectivity of logistic operations in distribution of non-alcoholic drinks

    OpenAIRE

    Radek Toušek; Jaroslava Pechová

    2008-01-01

    The article is focused on optimization of logistic operations in food stuff industry with emphasis on non-alcoholic drinks form the point of view of the usage of common applied wrapping technologies potential. Especially the attention is paid to the influence of used packages over the level of logistic costs including the influence of used packages over the transport intensity of logistic operations.

  18. Sport socks do not enhance calf muscle pump function but inelastic wraps do.

    Science.gov (United States)

    Partsch, H; Mosti, G

    2014-12-01

    Aim of the study was to measure the effect of elastic and inelastic compression on calf muscle pump function in healthy male athletes. This was an experimental study which included 21 healthy male athletes. The ejection fraction (EF) of the venous calf pump was measured comparing the effects of a variety of compression materials: 1) sport compression stockings; 2) light zinc paste bandages; 3) sport compression stockings with additional Velcro® wraps over the calf. The influence of sport stocking and wraps on the venous calibre at the largest calf circumference in the lying and standing position was investigated using MRI. Inelastic compression exerting a median pressure in the standing position of 37.5 mmHg (zinc paste) and 48 mmHg (loosely applied straps over a sport stocking) achieved a significant increase of EF up to 100%. Sport stockings alone with a standing pressure of 19-24 mmHg did not show a significant change of EF. MRI demonstrated some venous narrowing in the lying but not in the standing position. By wrapping inelastic straps over the stocking an emptying of the veins in the lying and a considerable narrowing in the standing position could be observed. Venous calf pump function in athletes is not influenced by elastic sport stockings, but inelastic wraps either alone or applied over sport stockings lead to a significant enhancement.

  19. Polymer Composite Wrapping and Cathodic Protection System for Reinforced Concrete Piles in Marine Applications

    Science.gov (United States)

    2013-06-01

    pile. The contractor was directed to design and develop a thermoset FRP pile wrapping system utilizing commercially available products. Contract re...Total anode weight in submerged/mud zone: 48 lb (net) ERDC/CERL TR-13-6 52 The anode configuration used for the project was 4 bulk zinc alloy anodes

  20. WRAP Module 1 data management system (DMS) software design description (SDD)

    International Nuclear Information System (INIS)

    Weidert, J.R.

    1996-01-01

    Revision 2 of the Waste Receiving and Processing (WRAP) Module 1 Data Management System (DMS) Preliminary Software Design Description (PSDD) provides a high-level design description of the system. The WRAP 1 DMS is required to collect, store, and report data related to certification, tracking, packaging, repackaging, processing, and shipment of waste processed or stored at the WRAP 1 facility. The WRAP 1 DMS SDD is used as the primary medium for communication software design information. This release provides design descriptions for the following process modules produced under Phase 1 of the development effort: Receiving Drum or Box Containers Process Routing and Picklists; Waste Inventory by Location and/or Container Relationships; LLW Process Glovebox Facility Radiologic Material Inventory Check (partial); Shipping (partial production); Drum or Box NDE Operations; and Drum or Box NDA Operations Data Review (partial production). In addition, design descriptions are included for the following process modules scheduled for development under Phases 2 and 3: Activity Comment; LLW RWM Glovebox Sample Management; TRU Process Glovebox; TRU RWM Glovebox; and TRUPACT Processing. Detailed design descriptions for Reports and Facility Metrics have also been provided for in Revision 2 of this document

  1. Dynamic investigation of DNA bending and wrapping by type II topoisomerases

    Science.gov (United States)

    Shao, Qing; Finzi, Laura; Dunlap, David

    2009-11-01

    Type II topoisomerases catalyze DNA decatenation and unwinding which is crucial for cell division, and therefore type II topoisomerases are some of the main targets of anti-cancer drugs. A recent crystal structure shows that, during the catalytic cycle, a yeast type II topoimerase can bend a 10 base pair DNA segment by up to 150 degrees. Bacterial gyrase, another type II topoisomerase, can wrap DNA into a tight 180 degree turn. Bending a stiff polymer like DNA requires considerable energy and could represent the rate limiting step in the catalytic (topological) cycle. Using modified deoxyribonucleotides in PCR reactions, stiffer DNA fragments have been produced and used as substrates for topoisomerase II-mediated relaxation of plectonemes introduced in single molecules using magnetic tweezers. The wrapping ability of gyrase decreases for diamino-purine-substituted DNA in which every base pair has three hydrogen-bonds. The overall rate of relaxation of plectonemes by recombinant human topoisomerase II alpha also decreases. These results reveal the dynamic properties of DNA bending and wrapping by type II topisomerases and suggest that A:T base pair melting is a rate determining step for bending and wrapping.

  2. AWWA C303-17 concrete pressure pipe, bar-wrapped, steel-cylinder type

    CERN Document Server

    2017-01-01

    This standard describes the manufacture of concrete pressure pipe, reinforced with a steel cylinder that is helically wrapped with mild steel bar reinforcement, in sizes ranging from 10 in. through 72 in. (250 mm through 1,830 mm), inclusive, and for working pressures up to 400 psi (2,760 kPa).

  3. QA Objectives for Nondestructive Assay at the Waste Receiving and Processing (WRAP) Facility

    International Nuclear Information System (INIS)

    WILLS, C.E.

    2000-01-01

    This report summarizes the validation of the WRAP NDA systems against the various QAOs. A brief description of each test and any significant conclusions is included. Variables which may have affected test outcomes are examined. This report will be reviewed semi-annually and updated as necessary

  4. Visual deterioration 1½ years after wrapping an un-clippable ...

    African Journals Online (AJOL)

    Objective: Optochiasmatic arachnoiditis (OCA) is a serious complication that can occur after wrapping of aneurysms in the proximity of the optic pathways. This paper seeks to illustrate one such case with a view to drawing attention to the dangers of this practice. Method: Single case report and review of the literature.

  5. Visual deterioration 1½ years after wrapping an un-clippable ...

    African Journals Online (AJOL)

    2005-09-02

    Sep 2, 2005 ... C/O Division of Neurosurgery, Department of Neurosciences,. University of the Witwatersrand, 7 York Rd. Parktown 2193,. Johannesburg, South Africa email: jmno@mweb.co.za. Visual deterioration 1½ years after wrapping an un-clippable anterior communicating artery aneurysm: report of a case and.

  6. Freedom of Contract in Click Wrap Agreements in Malaysia and the United States of America

    Directory of Open Access Journals (Sweden)

    Maryam Rafiei

    2011-06-01

    Full Text Available Technological advancement in the communications industry, particularly over the last decade, has given rise to consumers and commercial providers who want to form their own business or contractual agreements via the Internet. The mark of such technology can be seen in a new form of contract called “click wrap.”

  7. Membrane-Wrapping Contributions to Malaria Parasite Invasion of the Human Erythrocyte

    Science.gov (United States)

    Dasgupta, Sabyasachi; Auth, Thorsten; Gov, Nir S.; Satchwell, Timothy J.; Hanssen, Eric; Zuccala, Elizabeth S.; Riglar, David T.; Toye, Ashley M.; Betz, Timo; Baum, Jake; Gompper, Gerhard

    2014-01-01

    The blood stage malaria parasite, the merozoite, has a small window of opportunity during which it must successfully target and invade a human erythrocyte. The process of invasion is nonetheless remarkably rapid. To date, mechanistic models of invasion have focused predominantly on the parasite actomyosin motor contribution to the energetics of entry. Here, we have conducted a numerical analysis using dimensions for an archetypal merozoite to predict the respective contributions of the host-parasite interactions to invasion, in particular the role of membrane wrapping. Our theoretical modeling demonstrates that erythrocyte membrane wrapping alone, as a function of merozoite adhesive and shape properties, is sufficient to entirely account for the first key step of the invasion process, that of merozoite reorientation to its apex and tight adhesive linkage between the two cells. Next, parasite-induced reorganization of the erythrocyte cytoskeleton and release of parasite-derived membrane can also account for a considerable energetic portion of actual invasion itself, through membrane wrapping. Thus, contrary to the prevailing dogma, wrapping by the erythrocyte combined with parasite-derived membrane release can markedly reduce the expected contributions of the merozoite actomyosin motor to invasion. We therefore propose that invasion is a balance between parasite and host cell contributions, evolved toward maximal efficient use of biophysical forces between the two cells. PMID:24988340

  8. Super-energy wrap-up model for renovation of standard wooden houses in Greenland?

    DEFF Research Database (Denmark)

    Bjarløv, Søren Peter; Vladyková, Petra

    2012-01-01

    This paper is based on the developed theoretical practice of super-insulation solution for renovation of exiting standard wooden houses in Greenland built from 1950s until 2006, more than half the building stock in Arctic Greenland. From various perspectives, the wrap-up system is evaluated as a ...

  9. Influence of the stretch wrapping process on the mechanical behavior of a stretch film

    Science.gov (United States)

    Klein, Daniel; Stommel, Markus; Zimmer, Johannes

    2018-05-01

    Lightweight construction is an ongoing task in packaging development. Consequently, the stability of packages during transport is gaining importance. This study contributes to the optimization of lightweight packaging concepts regarding their stability. A very widespread packaging concept is the distribution of goods on a pallet whereas a Polyethylene (PE) stretch film stabilizes the lightweight structure during the shipment. Usually, a stretch wrapping machine applies this stretch film to the pallet. The objective of this study is to support packaging development with a method that predicts the result of the wrapping process, based on the mechanical characterization of the stretch film. This result is not only defined by the amount of stretch film, its spatial distribution on the pallet and its internal stresses that result in a containment force. More accurate, this contribution also considers the influence of the deformation history of the stretch film during the wrapping process. By focusing on similarities of stretch wrappers rather than on differences, the influence of generalized process parameters on stretch film mechanics and thereby on pallet stability can be determined experimentally. For a practical use, the predictive method is accumulated in an analytic model of the wrapping process that can be verified experimentally. This paves the way for experimental and numerical approaches regarding the optimization of pallet stability.

  10. Chromatographic properties PLOT multicapillary columns.

    Science.gov (United States)

    Nikolaeva, O A; Patrushev, Y V; Sidelnikov, V N

    2017-03-10

    Multicapillary columns (MCCs) for gas chromatography make it possible to perform high-speed analysis of the mixtures of gaseous and volatile substances at a relatively large amount of the loaded sample. The study was performed using PLOT MCCs for gas-solid chromatography (GSC) with different stationary phases (SP) based on alumina, silica and poly-(1-trimethylsilyl-1-propyne) (PTMSP) polymer as well as porous polymers divinylbenzene-styrene (DVB-St), divinylbenzene-vinylimidazole (DVB-VIm) and divinylbenzene-ethylene glycol dimethacrylate (DVB-EGD). These MCCs have the efficiency of 4000-10000 theoretical plates per meter (TP/m) and at a column length of 25-30cm can separate within 10-20s multicomponent mixtures of substances belonging to different classes of chemical compounds. The sample amount not overloading the column is 0.03-1μg and depends on the features of a porous layer. Examples of separations on some of the studied columns are considered. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Polyethylene versus cotton cap as an adjunct to body wrap in preterm infants.

    Science.gov (United States)

    Shafie, Hashim; Syed Zakaria, Syed Zulkifli; Adli, Ali; Shareena, Ishak; Rohana, Jaafar

    2017-07-01

    Occlusive body wrap using polyethylene plastic applied immediately after birth had been shown to reduce hypothermia among preterm infants. Various adjunct methods have been studied in an attempt to further reduce the incidence of hypothermia. This study was conducted to determine whether polyethylene cap is more effective than cotton cap as an adjunct to polyethylene occlusive body wrap in reducing hypothermia in preterm infants. The subjects consisted of preterm infants 24-34 weeks' gestation born at Universiti Kebangsaan Malaysia Medical Centre. Infants were randomly assigned to NeoCap or control groups. Infants in both groups were wrapped in polyethylene sheets from the neck downwards immediately after birth without prior drying. Infants in the control group had their heads dried and subsequently covered with cotton caps while infants in the NeoCap group had polyethylene caps put on without drying. Axillary temperature was measured on admission to the neonatal intensive care unit (NICU), and after having been stabilized in the incubator. Among the 80 infants recruited, admission hypothermia (axillary temperature <36.5°C) was present in 37 (92.5%) and in 40 (100%) in the NeoCap and control groups, respectively. There was no significant difference in mean temperature on NICU admission between the two groups (35.3 vs 35.1°C, P = 0.36). Mean post-stabilization temperature, however, was significantly higher in the NeoCap group (36.0 vs 35.5°C, P = 0.01). Combined use of polyethylene body wrap and polyethylene cap was associated with a significantly higher mean post-stabilization temperature compared with polyethylene body wrap and cotton cap. © 2017 Japan Pediatric Society.

  12. Extended storage of gamma-irradiated mango at tropical ambient temperature by film wrap packaging

    International Nuclear Information System (INIS)

    Janave, Machhindra T.; Sharma, A.

    2005-01-01

    Low dose gamma-irradiation of pre-climacteric mango (Mangifera indica L var.'Alphonso') fruits at 100 Gy extended the shelf-life at ambient temperature (28-32 degC) by 5-6 days. The extension of shelf-life was dose dependent, maximum being at 200 Gy by about 8-10 days. Wrapping the fruits in food grade Klin Wrap film resulted in more number of fruits remaining in semiripe condition after 21 days of storage as revealed by colour of the fruits, texture, TSS, pH, acidity and vitamin C content. The fruits retained about 40% of chlorophyll however, unwrapped fruits were complete yellow. Physiological weight loss (PWL) was reduced by 50% in Klin film wrapped fruits as compared to that in unwrapped fruits. More than 70-80% fruits remained as marketable fruits at the end of experiment when control fruits were slightly overripe. The shelf-life in Klin film wrapped irradiated mangoes was extended by about 10-15 days over irradiated unwrapped fruits resulting in total shelf-life of about 25-30 days at room temperature. In mangoes of variety 'Dasheri', gamma-irradiation extended the shelf-life by 4-5 days, which could be increased further, by another 7-10 days by Klin wrap packaging. These fruits also remained green at the end of experiment, confirming the observations with 'Alphonso' mango. These results show that low dose gamma-irradiation in combination with Klin film packaging delayed ripening as indicated by higher retention of fruit colour and reduction of PWL. (author)

  13. Characterization of geopolymer fly-ash based foams obtained with the addition of Al powder or H{sub 2}O{sub 2} as foaming agents

    Energy Technology Data Exchange (ETDEWEB)

    Ducman, V., E-mail: vilma.ducman@zag.si; Korat, L.

    2016-03-15

    Recent innovations in geopolymer technology have led to the development of various different types of geopolymeric products, including highly porous geopolymer-based foams, which are formed by the addition of foaming agents to a geopolymer fly-ash based matrix. These agents decompose, or react with the liquid matrix or oxygen in the matrix, resulting in the release of gases which form pores prior to the hardening of the gel. The hardened structure has good mechanical and thermal properties, and can therefore be used for applications in acoustic panels and in lightweight pre-fabricated components for thermal insulation purposes. This study presents the results of the pore-forming process in the case when two different foaming agents, i.e. aluminium powder amounting to 0.07, 0.13 and 0.20 mass. % and H{sub 2}O{sub 2} amounting to 0.5, 1.0, 1.5 and 2.0 mass. %, were added to a fly-ash geopolymer matrix. The physical, mechanical, and microstructural properties of the thus obtained foams, and the effects of the type and amount of the added foaming agent, are presented and discussed. Highly porous structures were obtained in the case of both of the investigated foaming agents, with overall porosities up to 59% when aluminium powder was added, and of up 48% when H{sub 2}O{sub 2} was added. In the latter case, when 2% of the H{sub 2}O{sub 2} foaming agent was added, finer pores (with diameters up to 500 μm) occurred in the structure, whereas somewhat larger pores (some had diameters greater than 1 mm) occurred when the same amount of aluminium powder was added. The mechanical properties of the investigated foams depended on their porosity. In the case of highly porous structures a compressive strength of 3.3 MPa was nevertheless achieved for the samples containing 0.2% of aluminium powder, and 3.7 MPa for those containing 2.0% of H{sub 2}O{sub 2}. - Highlights: • Preparation of geopolymer foams based on fly ash with the addition of Al powder or H{sub 2}O{sub 2} as

  14. Modeling of column apparatus processes

    CERN Document Server

    Boyadjiev, Christo; Boyadjiev, Boyan; Popova-Krumova, Petya

    2016-01-01

    This book presents a new approach for the modeling of chemical and interphase mass transfer processes in industrial column apparatuses, using convection-diffusion and average-concentration models. The convection-diffusion type models are used for a qualitative analysis of the processes and to assess the main, small and slight physical effects, and then reject the slight effects. As a result, the process mechanism can be identified. It also introduces average concentration models for quantitative analysis, which use the average values of the velocity and concentration over the cross-sectional area of the column. The new models are used to analyze different processes (simple and complex chemical reactions, absorption, adsorption and catalytic reactions), and make it possible to model the processes of gas purification with sulfur dioxide, which form the basis of several patents.

  15. Studies of column supported towers

    International Nuclear Information System (INIS)

    Chauvel, D.; Costaz, J.-L.

    1991-01-01

    As a result of a research and development programme into the civil engineering of cooling towers launched in 1978 by Electricite de France, very high cooling towers were built at Golfech and Chooz, in France, using column supports. This paper discusses the evolution of this new type of support from classical diagonal supports, presents some of the results of design calculations and survey measurements taken during construction of the shell and analyses the behaviour of the structure. (author)

  16. SPEEDUPtrademark ion exchange column model

    International Nuclear Information System (INIS)

    Hang, T.

    2000-01-01

    A transient model to describe the process of loading a solute onto the granular fixed bed in an ion exchange (IX) column has been developed using the SpeedUptrademark software package. SpeedUp offers the advantage of smooth integration into other existing SpeedUp flowsheet models. The mathematical algorithm of a porous particle diffusion model was adopted to account for convection, axial dispersion, film mass transfer, and pore diffusion. The method of orthogonal collocation on finite elements was employed to solve the governing transport equations. The model allows the use of a non-linear Langmuir isotherm based on an effective binary ionic exchange process. The SpeedUp column model was tested by comparing to the analytical solutions of three transport problems from the ion exchange literature. In addition, a sample calculation of a train of three crystalline silicotitanate (CST) IX columns in series was made using both the SpeedUp model and Purdue University's VERSE-LC code. All test cases showed excellent agreement between the SpeedUp model results and the test data. The model can be readily used for SuperLigtrademark ion exchange resins, once the experimental data are complete

  17. Two generalizations of column-convex polygons

    International Nuclear Information System (INIS)

    Feretic, Svjetlan; Guttmann, Anthony J

    2009-01-01

    Column-convex polygons were first counted by area several decades ago, and the result was found to be a simple, rational, generating function. In this work we generalize that result. Let a p-column polyomino be a polyomino whose columns can have 1, 2, ..., p connected components. Then column-convex polygons are equivalent to 1-convex polyominoes. The area generating function of even the simplest generalization, namely 2-column polyominoes, is unlikely to be solvable. We therefore define two classes of polyominoes which interpolate between column-convex polygons and 2-column polyominoes. We derive the area generating functions of those two classes, using extensions of existing algorithms. The growth constants of both classes are greater than the growth constant of column-convex polyominoes. Rather tight lower bounds on the growth constants complement a comprehensive asymptotic analysis.

  18. Reduced graphene oxide and Ag wrapped TiO2 photocatalyst for enhanced visible light photocatalysis

    International Nuclear Information System (INIS)

    Leong, Kah Hon; Sim, Lan Ching; Jang, Min; Ibrahim, Shaliza; Bahnemann, Detlef; Saravanan, Pichiah

    2015-01-01

    A well-organised reduced graphene oxide (RGO) and silver (Ag) wrapped TiO 2 nano-hybrid was successfully achieved through a facile and easy route. The inherent characteristics of the synthesized RGO-Ag/TiO 2 were revealed through crystalline phase, morphology, chemical composition, Raman scattering, UV-visible absorption, and photoluminescence analyses. The adopted synthesis route significantly controlled the uniform formation of silver nanoparticles and contributed for the absorption of light in the visible spectrum through localized surface plasmon resonance effects. The wrapped RGO nanosheets triggered the electron mobility and promoted visible light shift towards red spectrum. The accomplishment of synergised effect of RGO and Ag well degraded Bisphenol A under visible light irradiation with a removal efficiency of 61.9%

  19. Wrapped and unwrapped phase of radiation scattered by a discrete number of particles

    International Nuclear Information System (INIS)

    Watson, Stephen M; Ridley, Kevin D

    2007-01-01

    This paper investigates wrapped and unwrapped phase differences generated by a non-Gaussian scattering model: the two-dimensional random walk. Mean square values for these quantities are obtained for one and two scatterers, as well as the large scatterer limit when the field constitutes a circular complex Gaussian process. Numerical simulation is used to investigate the phase under more general fluctuation conditions, and reveals that the wrapped phase difference correlation converges rapidly to that result predicted for a Gaussian speckle field. Analytical results for the unwrapped phase indicate that this quantity transitions from a stationary process for one and two scatterers to a non-stationary process in the large scatterer limit. The nature of this transition is examined using numerical simulation for arbitrary scatterer number. Phase correlations are of consequence in various phase sensitive detection systems, and this paper examines both Gaussian and non-Gaussian fields

  20. User's guide to input for WRAP: a water reactor analysis package

    International Nuclear Information System (INIS)

    Gregory, M.V.

    1977-06-01

    The document describes the input records required to execute the Water Reactor Analysis Package (WRAP) for the analysis of thermal-hydraulic transients in primarily light water reactors. The card input required by RELAP4 has been significantly modified to broaden the code's input processing capabilities: (1) All input is in the form of templated, named records. (2) All components (volumes, junctions, etc.) are named rather than numbered, and system relationships are formed by defining associations between the names. (3) A hierarchical part structure is used which allows collections of components to be described as discrete parts (these parts may then be catalogued for use in a wide range of cases). A sample problem, the small break analysis of the Westinghouse Trojan Plant, is discussed and detailed, step-by-step instructions in setting up an input data base are presented. A master list of all input templates for WRAP is compiled

  1. Control characteristics for wrap-around fins on cruise missiles configurations

    Science.gov (United States)

    Sawyer, W. C.; Monta, W. J.; Carter, W. V.; Alexander, W. K.

    1981-01-01

    This paper presents selected results of a panel loads study conducted as part of the final phase of an extensive investigation of an air-breathing missile concept employing wrap-around aerodynamic surfaces. Typical results for M = 2.36 are presented for the fin load results, plus a brief review of basic results of the previously reported tests. Vapor screen results are also discussed. The present results indicate that the fin load characteristics are nearly identical for planar and curved fins having the same projected planform and would permit the use of planar-surface predictions for supersonic speeds in the preliminary design stages of missiles employing wrap-around curved fins.

  2. Turbulent-flow split model and supporting experiments for wire-wrapped core assemblies

    International Nuclear Information System (INIS)

    Chiu, C.; Todreas, N.; Rohsenow, W.

    1978-04-01

    A flow split model for the turbulent flow in a wire-wrapped nuclear fuel rod assembly is developed taking the form drag and sweeping flow between subchannels into consideration. This model is applicable to the flow distribution between two types of subchannels, i.e., interior and edge subchannels. The constants in this model for each type of subchannel were determined using all experimental data in the literature and the results of two tests performed as part of this study to fill a gap in the available literature. These experiments to measure flow split were performed on two wire-wrapped 61 pin bundles of pin pitch to pin diameter ratio, P/D, equal to 1.063 and wire lead to pin diameter ratios, H/D, of 4 and 8. The predictions of this model match all experimental data in the literature within +- 5%

  3. Feasibility of using cling-wrap films as a packaging material for radiation processed foods

    International Nuclear Information System (INIS)

    Choudhari, Vilendra V.; Chatterjee, Suchandra; Variyar, Prasad S.; Sharma, Arun

    2005-01-01

    Effect of gamma radiation (2 and 10 kgGy) on the stability of commercially available cling-wrap films for minimally processed foods was investigated. Migration of additives from the films into diethyl ether and water was monitored by TLC and by GC/MS analysis of their acetylated derivatives. Diocytyl phthalate was identified in the ether extract as the major migrant accounting for 98% of the total constituents detected. Other migrants identified in the minor amounts ( t 32.29 min corresponding to 1,3- dichloro-2-propanol. These changes, however, had no significant effect of the sensory and physical quality of the film. Thus feasibility of the using cling-wrap films as a packaging material for radiation processed food has been established. (author)

  4. Wire-wrapped rod-bundle heat-transfer analysis for LMFBR

    International Nuclear Information System (INIS)

    Wong, C.N.C.; Todreas, N.E.

    1982-07-01

    Helical wire wraps are widely used in the LMFBR fuel and blanket assemblies to provide coolant mixing and maintain proper spacing between fuel pins. The presence of the helical wire, however, may possibly induce heat transfer problems, such as the uncertainty of the maximum clad temperature as a result of the contact between the wires and the pins. In this study, the detailed transient three dimensional velocity and temperature distributions for the coolant around the pin will be determined by solving the governing momentum and energy equation numerically. A computer code HEATRAN has been developed to perform this calculation. Before the computer code HEATRAN is applied to the wire wrapped rod bundle problem, it is used to analyze a wide range of fluid and heat transfer problem to verify its capabilities

  5. The survival of Teredo navalis L. in timber wrapped in TERRAM4000 and a plastic membrane

    DEFF Research Database (Denmark)

    Eriksen, Anne Marie; Gregory, D. J.; Botfeldt, Knud Bo

    2014-01-01

    had been confirmed, the blocks were removed and wrapped in either TERRAM4000 (polypropylene and polyethylene) or a proprietary plastic membrane (polyethylene), normally used on fishing piles or piers, as a protection against shipworm in Denmark. An optical oxygen sensor was packed together with each...... block to measure the amount of available oxygen around the wood. After one week the oxygen level around the test blocks wrapped in the plastic membrane had dropped drastically and lead to the death of all shipworms within the test blocks after one-four weeks. Although no new shipworm attacked the wood...... plastic materials (TERRAM4000 and a plastic membrane) to stop both initial attack by T. navalis and their effects on wood with active woodborer degradation. Blocks of pinewood were submerged in the southern part of the Kattegat in Denmark, where shipworm is known to be prolific. After settling and attack...

  6. Brachial artery protected by wrapped latissimus dorsi muscle flap in high voltage electrical injury

    Science.gov (United States)

    Gencel, E.; Eser, C.; Kokacya, O.; Kesiktas, E.; Yavuz, M.

    2016-01-01

    Summary High voltage electrical injury can disrupt the vascular system and lead to extremity amputations. It is important to protect main vessels from progressive burn necrosis in order to salvage a limb. The brachial artery should be totally isolated from the burned area by a muscle flap to prevent vessel disruption. In this study, we report the use of a wrap-around latissimus dorsi muscle flap to protect a skeletonized brachial artery in a high voltage electrical injury in order to salvage the upper extremity and restore function. The flap wrapped around the exposed brachial artery segment and luminal status of the artery was assessed using magnetic resonance angiography. No vascular intervention was required. The flap survived completely with good elbow function. Extremity amputation was not encountered. This method using a latissimus dorsi flap allows the surgeon to protect the main upper extremity artery and reconstruct arm defects, which contributes to restoring arm function in high voltage electrical injury. PMID:28149236

  7. 29 CFR 1926.755 - Column anchorage.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Column anchorage. 1926.755 Section 1926.755 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.755 Column anchorage. (a) General requirements for erection stability. (1) All columns shall be anchored by a minimum of 4 anchor...

  8. Adsorption columns for use in radioimmunoassays

    International Nuclear Information System (INIS)

    1976-01-01

    Adsorption columns are provided which can be utilized in radioimmunoassay systems such as those involving the separation of antibody-antigen complexes from free antigens. The preparation of the columns includes the treatment of retaining substrate material to render it hydrophilic, preparation and degassing of the separation material and loading the column

  9. Thermal process of an air column

    International Nuclear Information System (INIS)

    Lee, F.T.

    1994-01-01

    Thermal process of a hot air column is discussed based on laws of thermodynamics. The kinetic motion of the air mass in the column can be used as a power generator. Alternatively, the column can also function as a exhaust/cooler

  10. Radioactive Air Emmission Notice of Construction (NOC) for the Waste Receiving and Processing Facility (WRAP)

    Energy Technology Data Exchange (ETDEWEB)

    MENARD, N.M.

    2000-12-01

    This document serves as a notice of construction (NOC) pursuant to the requirements of Washington Administrative Code (WAC) 246-247-060, and as a request for approval to modify pursuant to 40 Code of Federal Regulations (CFR) 61.07 for the Waste Receiving and Processing (WRAP) Facility. The rewrite of this NOC incorporates all the approved revisions (Sections 5.0, 6.0, 8.0, and 9.0), a revised potential to emit (PTE) based on the revised maximally exposed individual (MEI) (Sections 8.0, 10.0, 11.0, 12.0, 13.0, 14.0, and 15.0), the results of a study on fugitive emissions (Sections 6.0, 10.0, and 15.0), and reflects the current operating conditions at the WRAP Facility (Section 5.0). This NOC replaces DOE/RL-93-15 and DOE/RL-93-16 in their entirety. The primary function of the WRAP Facility is to examine, assay, characterize, treat, verify, and repackage radioactive material and mixed waste. There are two sources of emissions from the WRAP Facility: stack emissions and fugitive emissions. The stack emissions have an unabated total effective dose equivalent (TEDE) estimate to the hypothetical offsite MEI of 1.13 E+02 millirem per year. The abated TEDE for the stack emissions is estimated at 5.63 E-02 millirem per year to the MEI. The fugitive emissions have an unabated TEDE estimate to the hypothetical offsite MEI of 5.87 E-04. There is no abatement for the fugitive emissions.

  11. Radioactive Air Emmission Notice of Construction (NOC) Application for the Waste Receiving and Processing Facility (WRAP)

    International Nuclear Information System (INIS)

    MENARD, N.M.

    2000-01-01

    This document serves as a notice of construction (NOC) pursuant to the requirements of Washington Administrative Code (WAC) 246-247-060, and as a request for approval to modify pursuant to 40 Code of Federal Regulations (CFR) 61.07 for the Waste Receiving and Processing (WRAP) Facility. The rewrite of this NOC incorporates all the approved revisions (Sections 5.0, 6.0, 8.0, and 9.0), a revised potential to emit (PTE) based on the revised maximally exposed individual (MEI) (Sections 8.0, 10.0, 11.0, 12.0, 13.0, 14.0, and 15.0), the results of a study on fugitive emissions (Sections 6.0, 10.0, and 15.0), and reflects the current operating conditions at the WRAP Facility (Section 5.0). This NOC replaces DOE/RL-93-15 and DOE/RL-93-16 in their entirety. The primary function of the WRAP Facility is to examine, assay, characterize, treat, verify, and repackage radioactive material and mixed waste. There are two sources of emissions from the WRAP Facility: stack emissions and fugitive emissions. The stack emissions have an unabated total effective dose equivalent (TEDE) estimate to the hypothetical offsite MEI of 1.13 E+02 millirem per year. The abated TEDE for the stack emissions is estimated at 5.63 E-02 millirem per year to the MEI. The fugitive emissions have an unabated TEDE estimate to the hypothetical offsite MEI of 5.87 E-04. There is no abatement for the fugitive emissions

  12. Suffocation caused by plastic wrap covering the face combined with nitrous oxide inhalation.

    Science.gov (United States)

    Leth, Peter Mygind; Astrup, Birgitte Schmidt

    2017-09-01

    Suicide using a combination of a plastic bag over the head and inhalation of a non-irritating gas, such as helium, argon or nitrogen, has been reported in the literature. Here an unusual suicide method in a 17-year old man by suffocation from covering the face with household plastic wrap, combined with nitrous oxide inhalation, is presented. The case was reviewed based on police, autopsy and hospital reports. A PubMed search for scientific literature related to nitrous oxide abuse and suicide by suffocation was performed and our findings discussed in relation to the scientific literature found. The deceased was a 17-year old man who was found with the nose and mouth closed with a piece of kitchen plastic wrap. The plastic wrap had been removed prior to autopsy. Autopsy findings were suggestive of asphyxia, but were otherwise negative. Nitrous oxide was detected in the brain and lung tissue with headspace-gas chromatography-mass spectrometry (headspace-GCMS). The cause of death was assumed to be suffocation caused by plastic wrap covering the face, combined with nitrous oxide inhalation. Suicide was suspected because of a history of depression for several months. Nitrous oxide, also known as laughing gas, has a euphoric effect and is used as a recreational inhalant drug that can be purchased legally. Deaths caused by recreational nitrous oxide abuse are rare but may occur if used in combination with a plastic bag over the head. This is the first report of suicide by suffocation by external obstruction combined with nitrous oxide inhalation.

  13. A miniature implantable coil that can be wrapped around a tubular organ within the human body

    Science.gov (United States)

    Mao, Shitong; Wang, Hao; Mao, Zhi-Hong; Sun, Mingui

    2018-05-01

    There are many tubular or rod-shaped organs and tissues within the human body. A miniature medical implant that wraps around such a biological structure can monitor or modulate its function. In order to provide the wrap-around implant with power, a solenoidal coil coupled wirelessly with a planar coil outside the human body can be used. Unfortunately, there is a serious practical problem that this configuration cannot be realized easily because the implantable solenoidal coil cannot be positioned around the tubular biological structure unless either the structure or the coil is cut and reconnected, which is impermissible in most cases. In addition, when a planner exterior coil is used for wireless power transfer and communication, its maximum magnetic coupling with the implanted solenoidal coil is achieved when the tubular structure is perpendicular to the surface of the body. However, in human anatomy, most tubular/rod structures are oriented horizontally. In order to solve these problems, we present a new flexible coil for the class of wrapped-around implantable devices. Our multilayer coil has specially designed windings in cross patterns. The new coil can be made conveniently in high precision at low cost on a flat substrate using the same technology for making the flexible multilayer printed circuit boards along with miniature sensors and electronic circuits. This allows the implant to be made in a flat form and then wrapped around the biostructure during surgery. We present the design of this new coil, perform theoretical analysis with respect to its wireless power transfer efficiency, discuss the effects of coil parameters, and conduct experiments using constructed miniature prototypes. Our results confirm the validity of the new coil.

  14. The Role of Wet Wrap Therapy in Skin Disorders - A literature Review

    DEFF Research Database (Denmark)

    Andersen, Rosa Marie; Thyssen, Jacob P; Maibach, Howard I

    2015-01-01

    Wet wrap therapy, based on skin application of a double layer of tubular bandages or gauze with a moist first inner layer and a dry second outer layer, is utilized to treat various pruritic conditions, in particular severe and refractory atopic dermatitis. This review, by literature search...... may trigger increased lamellar body secretion resulting in recovery of the damaged intercellular lipid laminar structure. Otherwise, little investigation on mechanisms exists....

  15. Thermal hydraulic calculation of wire-wrapped bundles using a finite element method. Thesee code

    International Nuclear Information System (INIS)

    Rouzaud, P.; Gay, B.; Verviest, R.

    1981-07-01

    The physical and mathematical models used in the THESEE code now under development by the CEA/CEN Cadarache are presented. The objective of this code is to predict the fine three-dimensional temperature field in the sodium in a wire-wrapped rod bundle. Numerical results of THESEE are compared with measurements obtained by Belgonucleaire in 1976 in a sodium-cooled seven-rod bundle

  16. Ceramic fiber blanket wrap for fire protection of cable trays and conduits

    International Nuclear Information System (INIS)

    Chaille, C.E.; Reiman, R.J.

    1980-01-01

    In some areas of nuclear power plants, cables of redundant electrical systems, which are necessary for the safe shutdown of the reactor, are in close proximity. If a fire should occur in one of these areas, both electrical systems could be destroyed before the fire is extinguished and control of the reactor may be lost. A ceramic fiber blanket was evaluated as a fire protective wrap around cable trays and conduits. 2 refs

  17. Natural wrapping paper from banana (Musa paradisiaca Linn) peel waste with additive essential oils

    Science.gov (United States)

    Widiastuti Agustina, E. S.; Elfi Susanti, V. H.

    2018-05-01

    The research aimed to produce natural wrapping paper from banana (Musa Paradisiaca Linn.) peel waste with additive essentials oils. The method used in this research was alkalization. The delignification process is done with the use of NaOH 4% at the temperature of 100°C for 1.5 hours. Additive materials in the form of essential oils are added as a preservative and aroma agent, namely cinnamon oil, lemon oil, clove oil and lime oil respectively 2% and 3%. Chemical and physical properties of the produced papers are tested included water content (dry-oven method SNI ISO 287:2010), pH (SNI ISO 6588-1.2010), grammage (SNI ISO 536:2010) and brightness (SNI ISO 2470:2010). Testing results of each paper were compared with commercial wrapping paper. The result shows that the natural paper from banana peel waste with additive essential oil meets the standard of ISO 6519:2016 about Basic Paper for Laminated Plastic Wrapping Paper within the parameter of pH and water content. The paper produced also meet the standard of ISO 8218:2015 about Food Paper and Cardboard within the grammage parameter (high-grade grammage), except the paper with 2% lemon oil. The paper which is closest to the characteristic of commercial wrapping paper is the paper with the additive of 2% cinnamon oil, with pH of 6.95, the water content of 7.14%, grammage of 347.6 gram/m2 and the brightness level of 24.68%.

  18. Batching alternatives for Phase I retrieval wastes to be processed in WRAP Module 1

    International Nuclear Information System (INIS)

    Mayancsik, B.A.

    1994-01-01

    During the next two decades, the transuranic (TRU) waste now stored in the 200 Area burial trenches and storage buildings is to be retrieved, processed in the Waste Receiving and Processing (WRAP) Module 1 facility, and shipped to a final disposal facility. The purpose of this document is to identify the criteria that can be used to batch suspect TRU waste, currently in retrievable storage, for processing through the WRAP Module 1 facility. These criteria are then used to generate a batch plan for Phase 1 Retrieval operations, which will retrieve the waste located in Trench 4C-04 of the 200 West Area burial ground. The reasons for batching wastes for processing in WRAP Module 1 include reducing the exposure of workers and the environment to hazardous material and ionizing radiation; maximizing the efficiency of the retrieval, processing, and disposal processes by reducing costs, time, and space throughout the process; reducing analytical sampling and analysis; and reducing the amount of cleanup and decontamination between process runs. The criteria selected for batching the drums of retrieved waste entering WRAP Module 1 are based on the available records for the wastes sent to storage as well as knowledge of the processes that generated these wastes. The batching criteria identified in this document include the following: waste generator; type of process used to generate or package the waste; physical waste form; content of hazardous/dangerous chemicals in the waste; radiochemical type and quantity of waste; drum weight; and special waste types. These criteria were applied to the waste drums currently stored in Trench 4C-04. At least one batching scheme is shown for each of the criteria listed above

  19. A miniature implantable coil that can be wrapped around a tubular organ within the human body

    Directory of Open Access Journals (Sweden)

    Shitong Mao

    2018-05-01

    Full Text Available There are many tubular or rod-shaped organs and tissues within the human body. A miniature medical implant that wraps around such a biological structure can monitor or modulate its function. In order to provide the wrap-around implant with power, a solenoidal coil coupled wirelessly with a planar coil outside the human body can be used. Unfortunately, there is a serious practical problem that this configuration cannot be realized easily because the implantable solenoidal coil cannot be positioned around the tubular biological structure unless either the structure or the coil is cut and reconnected, which is impermissible in most cases. In addition, when a planner exterior coil is used for wireless power transfer and communication, its maximum magnetic coupling with the implanted solenoidal coil is achieved when the tubular structure is perpendicular to the surface of the body. However, in human anatomy, most tubular/rod structures are oriented horizontally. In order to solve these problems, we present a new flexible coil for the class of wrapped-around implantable devices. Our multilayer coil has specially designed windings in cross patterns. The new coil can be made conveniently in high precision at low cost on a flat substrate using the same technology for making the flexible multilayer printed circuit boards along with miniature sensors and electronic circuits. This allows the implant to be made in a flat form and then wrapped around the biostructure during surgery. We present the design of this new coil, perform theoretical analysis with respect to its wireless power transfer efficiency, discuss the effects of coil parameters, and conduct experiments using constructed miniature prototypes. Our results confirm the validity of the new coil.

  20. Final safety analysis report (FSAR) for waste receiving and processing (WRAP) facility

    International Nuclear Information System (INIS)

    Weidert, J.R.

    1997-01-01

    This safety analysis report provides a summary description of the WRAP Facility, focusing on significant safety-related characteristics of the location and facility design. This report demonstrates that adherence to the safety basis wi11 ensure necessary operational safety considerations have been addressed sufficiently and justifies the adequacy of the safety basis in protecting the health and safety of the public, workers, and the environment

  1. A Wrapping Method for Inserting Titanium Micro-Mesh Implants in the Reconstruction of Blowout Fractures

    Directory of Open Access Journals (Sweden)

    Tae Joon Choi

    2016-01-01

    Full Text Available Titanium micro-mesh implants are widely used in orbital wall reconstructions because they have several advantageous characteristics. However, the rough and irregular marginal spurs of the cut edges of the titanium mesh sheet impede the efficacious and minimally traumatic insertion of the implant, because these spurs may catch or hook the orbital soft tissue, skin, or conjunctiva during the insertion procedure. In order to prevent this problem, we developed an easy method of inserting a titanium micro-mesh, in which it is wrapped with the aseptic transparent plastic film that is used to pack surgical instruments or is attached to one side of the inner suture package. Fifty-four patients underwent orbital wall reconstruction using a transconjunctival or transcutaneous approach. The wrapped implant was easily inserted without catching or injuring the orbital soft tissue, skin, or conjunctiva. In most cases, the implant was inserted in one attempt. Postoperative computed tomographic scans showed excellent placement of the titanium micro-mesh and adequate anatomic reconstruction of the orbital walls. This wrapping insertion method may be useful for making the insertion of titanium micro-mesh implants in the reconstruction of orbital wall fractures easier and less traumatic.

  2. Analytical Call Center Model with Voice Response Unit and Wrap-Up Time

    Directory of Open Access Journals (Sweden)

    Petr Hampl

    2015-01-01

    Full Text Available The last twenty years of computer integration significantly changed the process of service in a call center service systems. Basic building modules of classical call centers – a switching system and a group of humans agents – was extended with other special modules such as skills-based routing module, automatic call distribution module, interactive voice response module and others to minimize the customer waiting time and wage costs. A calling customer of a modern call center is served in the first stage by the interactive voice response module without any human interaction. If the customer requirements are not satisfied in the first stage, the service continues to the second stage realized by the group of human agents. The service time of second stage – the average handle time – is divided into a conversation time and wrap-up time. During the conversation time, the agent answers customer questions and collects its requirements and during the wrap-up time (administrative time the agent completes the task without any customer interaction. The analytical model presented in this contribution is solved under the condition of statistical equilibrium and takes into account the interactive voice response module service time, the conversation time and the wrap-up time.

  3. DOE final report phase one startup, Waste Receiving and Processing Facility (WRAP)

    International Nuclear Information System (INIS)

    Jasen, W.G.

    1998-01-01

    This document is to validate that the WRAP facility is physically ready to start up phase 1, and that the managers and operators are prepared to safely manage and operate the facility when all pre-start findings have been satisfactorily corrected. The DOE Readiness Assessment (RA) team spent a week on-site at Waste Receiving and Processing Module 1 (WRAP-1) to validate the readiness for phase 1 start up of facility. The Contractor and DOE staff were exceptionally cooperative and contributed significantly to the overall success of the RA. The procedures and Conduct of Operations areas had significant discrepancies, many of which should have been found by the contractor review team. In addition the findings of the contractor review team should have led the WRAP-1 management team to correcting the root causes of the findings prior to the DOE RA team review. The findings and observations include many issues that the team believes should have been found by the contractor review and corrective actions taken. A significantly improved Operational Readiness Review (ORR) process and corrective actions of root causes must be fully implemented by the contractor prior to the performance of the contractor ORR for phase 2 operations. The pre-start findings as a result of this independent DOE Readiness Assessment are presented

  4. Control of flow around a circular cylinder wrapped with a porous layer by magnetohydrodynamic

    Energy Technology Data Exchange (ETDEWEB)

    Bovand, M. [Department of Mechanical Engineering, Semnan Branch, Islamic Azad University, Semnan (Iran, Islamic Republic of); Rashidi, S. [Department of Mechanical Engineering, Ferdowsi University of Mashhad, Mashhad 91775-1111 (Iran, Islamic Republic of); Esfahani, J.A., E-mail: abolfazl@um.ac.ir [Department of Mechanical Engineering, Ferdowsi University of Mashhad, Mashhad 91775-1111 (Iran, Islamic Republic of); Saha, S.C.; Gu, Y.T. [School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, GPO Box 2434, Brisbane, QLD 4001 (Australia); Dehesht, M. [School of Mechanical Engineering, Semnan University, P.O. Box 35196-45399, Semnan (Iran, Islamic Republic of)

    2016-03-01

    The present study focuses on the analysis of two-dimensional Magnetohydrodynamic (MHD) flow past a circular cylinder wrapped with a porous layer in different laminar flow regimes. The Darcy-Brinkman-Forchheimer model has been used for simulating flow in porous medium using finite volume based software, Fluent 6.3. In order to analyze the MHD flow, the mean and instantaneous drag and lift coefficients and stream patterns are computed to elucidate the role of Stuart number, N and Darcy number, Da. It is revealed that the magnetic fields are capable to stabilize flow and suppress the vortex shedding of vortices. The N-Re plane shows the curves for separating steady and periodic flow regimes, N{sub cr} and disappearing of vortex, N{sub diss}. For validate the solution, the obtained C{sub D} and St are compared with available results of literature. - Highlights: • The value of interaction parameter, N{sub cr}, depends on the Reynolds number. • N{sub cr} for porous-wrapped solid cylinder is less than the value of solid cylinder. • The St number of porous-wrapped cylinder is less than that of the rigid one. • When Da is decreased, St also decreases.

  5. Oesophageal flap valvuloplasty and wrapping suturing prevent gastrooesophageal reflux disease in dogs after oesophageal anastomosis

    Science.gov (United States)

    Dai, Ji-Gang; Liu, Quan-Xing; Den, Xu-Feng; Min, Jia-Xin

    2014-01-01

    AIM: To examine the efficiency of oesophageal flap valvuloplasty and wrapping suturing technique in decreasing the rate of postoperative gastrooesophageal reflux disease in a dog model. METHODS: We operated on 10 dogs in this study. First, we resected a 5-cm portion of the distal oesophagus and then restored the continuity of the oesophageal and gastric walls by end-to-end anastomosis. A group of five dogs was subjected to the oesophageal flap valvuloplasty and wrapping suturing technique, whereas another group (control) of five dogs was subjected to the stapling technique after oesophagectomy. The symptom of gastrooesophageal reflux was recorded by 24-h pH oesophageal monitoring. Endoscopy and barium swallow examination were performed on all dogs. Anastomotic leakage was observed by X-ray imaging, whereas benign anastomotic stricture and mucosal damage were observed by endoscopy. RESULTS: None of the 10 dogs experienced anastomotic leakage after oesophagectomy. Four dogs in the new technology group resumed regular feeding, whereas only two of the dogs in the control group tolerated solid food intake. pH monitoring demonstrated that 25% of the dogs in the experimental group exhibited reflux and that none had mucosal damage consistent with reflux. Conversely, both reflux and mucosal damage were observed in all dogs in the control group. CONCLUSION: The oesophageal flap valvuloplasty and wrapping suturing technique can improve the postoperative quality of life through the long-term elimination of reflux oesophagitis and decreased stricture formation after primary oesophageal anastomosis. PMID:25516655

  6. Water-reuse risk assessment program (WRAP: a refinery case study

    Directory of Open Access Journals (Sweden)

    Maria Dian Kurnia Sari

    2017-06-01

    Full Text Available The key approach to manage and prevent potential hazards arising from specific contaminants in water networks is to consider water as the main product delivered. This new concept, addressed as water-reuse risk assessment program (WRAP, has been further developed from hazard analysis of critical control points (HACCP to illustrate the potential hazards which are the roots of hindering intra-facility water reuse strategies. For industrial sectors applying water reclamation and reuse schemes, it is paramount that the reclaimed water quality stays within the desired quality. The objective of WRAP is to establish a new methodology and knowledge, which will contribute to the sustainable development of industrial water management, and demonstrate its capabilities in identifying and addressing any potential hazards in the selected schemes adoption by the industries. A ‘what-if’ scenario was simulated using a refinery as a case study to show strategies on how to benefit reclaimed or reuse water based on reliable, applied and scientific research within the process integration area. In conclusion, the WRAP model will facilitate operators, consultants and decision makers to reuse water on a fit-for-use basis whilst avoiding contaminant accumulation in the overall system and production of sub-quality products from inadequate processes after several reuses.

  7. A comparative analysis on the shed vortices from the wake of finned, foam-wrapped cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Khashehchi, Morteza [Department of Agro-Technology, College of Aburaihan, University of Tehran, Tehran (Iran, Islamic Republic of); Ashtiani Abdi, Iman; Hooman, Kamel, E-mail: m.khashehchi@ut.ac.ir [School of Mechanical and mining Engineering, University of Queensland, Brisbane (Australia)

    2017-08-15

    The wake characteristics behind a finned and a foam-wrapped circular cylinder has been compared in a study (Khashehchi et al 2014 Exp. Therm. Fluid Sci. 52 328–38) done by the Authors. In this paper, the shed vortices from the wake of the same cylinders have been studied. Shedding in a bluff body has an important effect on increasing the pressure drop downstream of the object. Here, we have used particle image velocimetry to investigate the detached vortices from the wake behind a foam-wrapped and a finned cylinder. The standard case of cross-flow over a bare cylinder, i.e. no surface extension, has also been tested as a benchmark. The experiments have been performed for Reynolds numbers 2000 based on the mean air velocity and the cylinder’s outer diameter. To identify the features of each aforementioned case, linear stochastic estimation has been applied to the velocity fields. Results show that unlike the fin, adding foam to the cylinder surface increases the size of detached vortices and amplifies the core strength. Moreover, foam-wrapped cylinder in contrast to the finned one produces strong three-dimensionality. Interestingly, finned cylinder’s results show less three-dimensionality compared to the bare cylinder. (paper)

  8. Enhancing the Supercapacitor Performance of Graphene/MnO 2 Nanostructured Electrodes by Conductive Wrapping

    KAUST Repository

    Yu, Guihua

    2011-10-12

    MnO2 is considered one of the most promising pseudocapactive materials for high-performance supercapacitors given its high theoretical specific capacitance, low-cost, environmental benignity, and natural abundance. However, MnO2 electrodes often suffer from poor electronic and ionic conductivities, resulting in their limited performance in power density and cycling. Here we developed a "conductive wrapping" method to greatly improve the supercapacitor performance of graphene/MnO2-based nanostructured electrodes. By three-dimensional (3D) conductive wrapping of graphene/MnO2 nanostructures with carbon nanotubes or conducting polymer, specific capacitance of the electrodes (considering total mass of active materials) has substantially increased by ∼20% and ∼45%, respectively, with values as high as ∼380 F/g achieved. Moreover, these ternary composite electrodes have also exhibited excellent cycling performance with >95% capacitance retention over 3000 cycles. This 3D conductive wrapping approach represents an exciting direction for enhancing the device performance of metal oxide-based electrochemical supercapacitors and can be generalized for designing next-generation high-performance energy storage devices. © 2011 American Chemical Society.

  9. Phase diagrams and morphological evolution in wrapping of rod-shaped elastic nanoparticles by cell membrane: A two-dimensional study

    Science.gov (United States)

    Yi, Xin; Gao, Huajian

    2014-06-01

    A fundamental understanding of cell-nanomaterial interaction is essential for biomedical diagnostics, therapeutics, and nanotoxicity. Here, we perform a theoretical analysis to investigate the phase diagram and morphological evolution of an elastic rod-shaped nanoparticle wrapped by a lipid membrane in two dimensions. We show that there exist five possible wrapping phases based on the stability of full wrapping, partial wrapping, and no wrapping states. The wrapping phases depend on the shape and size of the particle, adhesion energy, membrane tension, and bending rigidity ratio between the particle and membrane. While symmetric morphologies are observed in the early and late stages of wrapping, in between a soft rod-shaped nanoparticle undergoes a dramatic symmetry breaking morphological change while stiff and rigid nanoparticles experience a sharp reorientation. These results are of interest to the study of a range of phenomena including viral budding, exocytosis, as well as endocytosis or phagocytosis of elastic particles into cells.

  10. Osiris wrapped with the skin of the celestial fawn: note on D. S. I 11.4

    Directory of Open Access Journals (Sweden)

    Jónatan Ortiz-García

    2017-09-01

    Full Text Available In this paper it is proposed an explanation for certain information transmitted by Diodorus Siculus, according to which the Egyptian god Osiris was wrapped with a fawn skin with stars.

  11. Hydraulic conductivity of indeformed soil columns determination by gamma ray transmission

    International Nuclear Information System (INIS)

    Moreira, Anderson Camargo; Moraes Cavalcante, Fabio Henrique de; Rocha, Marcos Correa da; Filho, Otavio Portezan; Quinones, Fernando Rodolfo Espinosa; Appoloni, Carlos Roberto

    2000-01-01

    The spatial variation of the soil structure influences the water movement through its porous geometry, which could cause problems in the development of agricultural cultures and also accelerate processes of soil erosion. The gamma ray transmission method has established efficiency for the non-destructive measurement of moisture temporal and space evolution, and consequently in the determination of the hydraulic conductivity of the soil, K(θ). Columns of undisturbed soil (approximately 0.11 x 0.06 x 0.60 m) were removed from a trench in the Campus of Londrina State University. The used soil was classified like distrophic dark red soil (LRd). The indeformed soil columns were wrapped up with paraffin and gauze and were fixed on the table of measurement. The water vertical infiltration in the soil was accomplished by maintaining a water layer of approximately 0.01 m over an area of soil of 75 x 10 -4 m 2 . Layers of filter papers and foam controlled the flow of water in the soil surface. After the conclusion of the infiltration, began the process of redistribution of the water in the soil column, with the objective to determine the function K(θ) in relation to the depth in the column. The moisture profiles θ(z,t) are obtained using a radioactive source of 241 Am (3.7 x 10 9 Bq; 0.0596 MeV), spectrometric electronic chain, a 2x2'' NaI(Tl) detector and a measurements table , which allows the sample to move vertically. The hydraulic conductivity function was determined, applying the Sisson model , at 10 levels in the soil column and the results exhibit an increase of K(θ) with depth. (author)

  12. Behaviour of fibre reinforced polymer confined reinforced concrete columns under fire condition

    Science.gov (United States)

    Chowdhury, Ershad Ullah

    In recent years, fibre reinforced polymer (FRP) materials have demonstrated enormous potential as materials for repairing and retrofitting concrete bridges that have deteriorated from factors such as electro-chemical corrosion and increased load requirements. However, concerns associated with fire remain an obstacle to applications of FRP materials in buildings and parking garages due to FRP's sensitivity to high temperatures as compared with other structural materials and to limited knowledge on their thermal and mechanical behaviour in fire. This thesis presents results from an ongoing study on the fire performance of FRP materials, fire insulation materials and systems, and FRP wrapped reinforced concrete columns. The overall goal of the study is to understand the fire behaviour of FRP materials and FRP strengthened concrete columns and ultimately, provide rational fire safety design recommendations and guidelines for FRP strengthened concrete columns. A combined experimental and numerical investigation was conducted to achieve the goals of this research study. The experimental work consisted of both small-scale FRP material testing at elevated temperatures and full-scale fire tests on FRP strengthened columns. A numerical model was developed to simulate the behaviour of unwrapped reinforced concrete and FRP strengthened reinforced concrete square or rectangular columns in fire. After validating the numerical model against test data available in literature, it was determined that the numerical model can be used to analyze the behaviour of concrete axial compressive members in fire. Results from this study also demonstrated that although FRP materials experience considerable loss of their mechanical and bond properties at temperatures somewhat below the glass transition temperature of the resin matrix, externally-bonded FRP can be used in strengthening concrete structural members in buildings, if appropriate supplemental fire protection system is provided over

  13. Strain Measurement during Stress Rupture of Composite Over-Wrapped Pressure Vessel with Fiber Bragg Gratings Sensors

    Science.gov (United States)

    Banks, Curtis E.; Grant, Joseph; Russell, Sam; Arnett, Shawn

    2008-01-01

    Fiber optic Bragg gratings were used to measure strain fields during Stress Rupture (SSM) test of Kevlar Composite Over-Wrapped Pressure Vessels (COPV). The sensors were embedded under the over-wrapped attached to the liner released from the Kevlar and attached to the Kevlar released from the liner. Additional sensors (foil gages and fiber bragg gratings) were surface mounted on the COPY liner.

  14. Pengaruh Penggunaan Plastic Wrap Terhadap Core Temperature Pasien Pediatrik 1-3 Tahun Yang Menjalani Operasi Palatoplasty

    OpenAIRE

    Mikhail Averoes; Suwarman; Eri Surahman

    2013-01-01

    The decrease rate of body temperature can be reduced by passive insulation by covering the body with certain materials which have poor heat conductivity (insulator). Insulator material which is wrapped on the body can prevent the process of convection, conduction and evaporation so that the degree of heat loss was reduced on average 30%. One material that can be used as an insulator is the plastic. This study was conducted to assess the effect of plastic wrap on the core temperature of pediat...

  15. Pengaruh Penggunaan Plastic Wrap Terhadap Core Temperature Pasien Pediatrik 1-3 Tahun Yang Menjalani Operasi Palatoplasty

    Directory of Open Access Journals (Sweden)

    Mikhail Averoes

    2013-04-01

    Full Text Available The decrease rate of body temperature can be reduced by passive insulation by covering the body with certain materials which have poor heat conductivity (insulator. Insulator material which is wrapped on the body can prevent the process of convection, conduction and evaporation so that the degree of heat loss was reduced on average 30%. One material that can be used as an insulator is the plastic. This study was conducted to assess the effect of plastic wrap on the core temperature of pediatric aged 1 to 3 years who underwent cleft palate surgery. The study was conducted on 30 pediatric patients, aged 1-3 years, with ASA I physical status who underwent cleft surgery with general anesthesia. Patients were divided into two groups. One group used plastic wrap to be wrapped on the body, and another is the control group. Rectal temperature was recorded during anesthesia. Research data was tested statistically by the Mann-Whitney test. The results of statistical calculation indicated that the average core temperature during anesthesia in plastic wrap group was higher than the control group with a significant result (p <0.001. The average core temperature in the plastic wrap is 36.17° C (0.31° C which is higher than the control group (35.88° C (0.43° C. It can be concluded that the use of plastic wrap causes temperature reduction degree to be lower than the control group. The degree in plastic wrap group is 0.8 °C while the degree in control group is 1.2°C in the control group (p <0.005.

  16. Performance and Behaviour of Ground Granulated Blast Furnace Slag Imparted to Geopolymer Concrete Structural Elements and Analyzed with ANSYS

    Directory of Open Access Journals (Sweden)

    Maria Rajesh Antonyamaladhas

    2016-01-01

    Full Text Available This paper deals with the behaviour of geopolymer concrete using ground granulated blast furnace slag and steel fibre to compare with M40 grade cement concrete. The cast GPC specimens were placed in a hot curing chamber at 60∘C temperature for 24 hours and tested after 1, 7, 14, and 28 days of ambient curing to find the strength and durability of hardened concrete. The optimum value of compressive strength was attained at 12 Molarities. Fly ash was replaced by GGBS in GPC with different proportions such as 0% to 60% at 5% interval; the optimum strength value was obtained on 40% replacement. From the test results, the compressive, split-tensile, and flexural strength of GPC specimens were 20%, 43%, and 53% higher than those of the control specimens. Based on the optimum strength mix proportion, the structural elements were cast to investigate the stress-strain relations. The GPC beam and L-section showed 33% and 16% higher value. From the results of acid and sulphate resistance tests, it was found that the strength and weight ratio of GPC were higher than the control specimens. From the simulations, it was found that the experimental test results were approximately equal to the ANSYS.

  17. EFFECT OF SODIUM HYDROXIDE CONCENTRATION ON FRESH PROPERTIES AND COMPRESSIVE STRENGTH OF SELF-COMPACTING GEOPOLYMER CONCRETE

    Directory of Open Access Journals (Sweden)

    FAREED AHMED MEMON

    2013-02-01

    Full Text Available This paper reports the results of the laboratory tests conducted to investigate the effect of sodium hydroxide concentration on the fresh properties and compressive strength of self-compacting geopolymer concrete (SCGC. The experiments were conducted by varying the concentration of sodium hydroxide from 8 M to 14 M. Test methods such as Slump flow, V-Funnel, L-box and J-Ring were used to assess the workability characteristics of SCGC. The test specimens were cured at 70°C for a period of 48 hours and then kept in room temperature until the day of testing. Compressive strength test was carried out at the ages of 1, 3, 7 and 28 days. Test results indicate that concentration variation of sodium hydroxide had least effect on the fresh properties of SCGC. With the increase in sodium hydroxide concentration, the workability of fresh concrete was slightly reduced; however, the corresponding compressive strength was increased. Concrete samples with sodium hydroxide concentration of 12 M produced maximum compressive strength.

  18. Effect of spice-incorporated starch edible film wrapping on shelf life of white shrimps stored at different temperatures.

    Science.gov (United States)

    Meenatchisundaram, Sivarajan; Chandrasekar, Chandra Mohan; Udayasoorian, Lalitha Priya; Kavindapadi Rajasekaran, Rakhavan; Kesavan, Radha Krishnan; Srinivasan, Babuskin; Muthusamy, Sukumar

    2016-09-01

    White shrimps (Litopenaeus vannamei) are a major aquaculture product in the world fishery market. The main aim of this study was to investigate the effect of clove- and cinnamon-assimilated starch edible films on the shelf life of white shrimps in terms of maintaining their freshness and other organoleptic properties. Physical, chemical, microbial and sensory qualities of edible film-wrapped white shrimps were studied until they reached their limit of acceptability during storage at different temperatures (10 and 4 °C). Shrimp samples wrapped with spice-assimilated edible films showed lower bacterial counts. Shelf life extension of edible film-wrapped white shrimps was estimated to be 14 and 12 days for storage at 10 and 4 °C respectively. Reduced lipid oxidation and release of nitrogen base compounds were noted for edible film-wrapped shrimp samples. Good consumer acceptance was noted for edible film-wrapped shrimp samples through sensory evaluation. The results of this study show that spice-fused edible films were effective in inhibiting the growth of microbial populations. Reductions in lipid oxidation and total volatile base nitrogen were also achieved through edible film wrapping of shrimps, which increased their consumer acceptance during sensory evaluation. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  19. Cadaver wrapping and arrival performance of adult flies in an oil palm plantation in northern Peninsular Malaysia.

    Science.gov (United States)

    Ahmad, Azwani; Ahmad, Abu Hassan; Dieng, Hamady; Satho, Tomomitsu; Ahmad, Hamdan; Aziz, Al Thbyani; Boots, Michael

    2011-11-01

    There is accumulating evidence that criminals wrap dead bodies in an attempt to conceal evidence. To anticipate the forensic implications of this phenomenon, we examined whether flies that are naturally associated with cadavers exhibit a delay in attendance or differ in species composition and abundance patterns because of the presence of wrapping material. Wrapped and exposed carcasses of dead monkeys placed in an oil plantation in Kedah, Malaysia, were visited over 50 d. On daily visits to each of the six carcasses, visiting adult flies were sampled using hand nets. Flies of 12 families were encountered. Calliphoridae (Chrysomya rufifacies Macquart and C. megacephala (F.) was the most prevalent family, followed by Sphaeroceridae. Some families tended to be more abundant in WRCs (i.e., Calliphoridae, Muscidae, and Phoridae), whereas others (i.e., Piophilidae, Sepsidae, and Psychodidae) were more prevalent in exposed carcasses. Wrapping delayed the arrival of all fly species encountered, with delays varying from 1 to 13 d depending on species. Wrapping did not affect species composition of flies, but prolong the occurrence of some species. The results of the current study emphasize the need to take into consideration the presence of a wrap when estimating postmortem interval.

  20. Evaluation of Packed Distillation Columns I - Atmospheric Pressure

    National Research Council Canada - National Science Library

    Reynolds, Thaine

    1951-01-01

    .... Four column-packing combinations of the glass columns and four column-packing combinations of the steel columns were investigated at atmospheric pressure using a test mixture of methylcyclohexane...

  1. Oscillating water column structural model

    Energy Technology Data Exchange (ETDEWEB)

    Copeland, Guild [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bull, Diana L [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jepsen, Richard Alan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gordon, Margaret Ellen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    An oscillating water column (OWC) wave energy converter is a structure with an opening to the ocean below the free surface, i.e. a structure with a moonpool. Two structural models for a non-axisymmetric terminator design OWC, the Backward Bent Duct Buoy (BBDB) are discussed in this report. The results of this structural model design study are intended to inform experiments and modeling underway in support of the U.S. Department of Energy (DOE) initiated Reference Model Project (RMP). A detailed design developed by Re Vision Consulting used stiffeners and girders to stabilize the structure against the hydrostatic loads experienced by a BBDB device. Additional support plates were added to this structure to account for loads arising from the mooring line attachment points. A simplified structure was designed in a modular fashion. This simplified design allows easy alterations to the buoyancy chambers and uncomplicated analysis of resulting changes in buoyancy.

  2. Detection of Cocoa Pod Borer Infestation Using Sex Pheromone Trap and its Control by Pod Wrapping

    Directory of Open Access Journals (Sweden)

    Dian Rahmawati

    2017-07-01

    Full Text Available Cocoa pod borer (CPB, Conopomorpha cramerella Snellen (Lepidoptera: Gracillariidae is a major pest of cocoa. Detection of the pest infestation using sex pheromone traps in the early growth and development of cocoa pods is important for an early warning system programme. In order to prevent the pest infestation the young pods were wrapped with plastic bags. A research to study the CPB incidence was conducted at cocoa plantations in Banjarharjo and Banjaroya villages, District of Kalibawang; Hargotirto and Hargowilis villages, District of Kokap; and Pagerharjo village, District of Samigaluh, Yogyakarta. The experiments design used RCBD with four treatments (sex pheromone trap, combination of sex pheromone trap and pod wrapping, pod wrapping, and control and five replications. As many as 6 units/ha pheromone traps were installed with a distance of 40 m in between. Results showed that one month prior to the trap installation in the experimental plots there were ripen cocoa pods as many as 9-13%, which were mostly infested by CPB. During the time period of introducting research on August to Desember 2016 there was not rambutan fruits as the CPB host, hence the CPB resource was from infested cocoa pods. The CPB moth trapped as many as 0−7 (1.13 ± 0.14 moths/6 traps/12 observations. The seed damage due to CPB larvae in the pheromone trap treatments (23.98% was relatively similar with the control (20.25%. Seed damage rate in combination treatment of pheromone trap and pod wrapping (0.59% was relatively the same with the pod wrapping (0.20%. The pheromone trap was more usefull for monitoring tool rather than for control, meanwhile pod wrapping was an effective control measure of CPB.   Intisari Penggerek Buah Kakao (PBK, Conopomorpha cramerella Snellen (Lepidoptera: Gracillariidae merupakan salah satu hama utama kakao. Deteksi serangan hama PBK dengan perangkap feromon seks pada awal pertumbuhan dan perkembangan buah kakao penting dilakukan sebagai

  3. MnO{sub 2}-wrapped hollow graphitized carbon nanosphere electrode for supercapacitor

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Jing; Yang, Xing; Zhou, Haiyan; Kang, Liping; Lei, Zhibin [Key Laboratory of Applied Surface and Colloid Chemistry (Shaanxi Normal University), Ministry of Education, Xi’an 710062 (China); School of Materials Science and Engineering, Shaanxi Normal University, Xi’an 710062 (China); Liu, Zong-Huai, E-mail: zhliu@snnu.edu.cn [Key Laboratory of Applied Surface and Colloid Chemistry (Shaanxi Normal University), Ministry of Education, Xi’an 710062 (China); School of Materials Science and Engineering, Shaanxi Normal University, Xi’an 710062 (China)

    2016-01-15

    Highlights: • MnO{sub 2}/HGC nanospheres are prepared by a cooperative template wrapping method. • MnO{sub 2}/HGC nanospheres possess large specific surface area. • MnO{sub 2}/HGC nanospheres are benefit for transmission of ions and electrons. • MnO{sub 2}/HGC electrodes exhibit a high specific capacitance. - Abstract: MnO{sub 2}-wrapped hollow graphitized carbon nanospheres (MnO{sub 2}/HGC) electrodes are prepared by a cooperative template wrapping method. hollow Graphitized carbon nanospheres (HGC) are firstly obtained by carbonizing phenolic resin followed by etching the SiO{sub 2} template, then the MnO{sub 2} ultrathin nanoplates are coated on the surfaces of the HGC nanospheres through a redox reaction between KMnO{sub 4} and HGC nanospheres. The as-prepared MnO{sub 2}/HGC hollow nanospheres possess porous structure and large specific surface area (∼230 m{sup 2} g{sup −1}). The specific capacitances of MnO{sub 2}/HGC nanosphere electrodes with different mass ratios of MnO{sub 2} to HGC are about 340–380 F g{sup −1} at a scan rate of 5 mV s{sup −1} in Na{sub 2}SO{sub 4} solution, and shows relative good cycling performance of the initial capacitance after 1000 cycles. The good specific capacitance is ascribed to the novel hollow nanosphere structure, which possesses high surface-to-volume ratio, and makes it easy for the mass diffusion of electrolyte and transmission of ions and electrons and also maintains the mechanical integrality.

  4. Camembert-type cheese ripening dynamics are changed by the properties of wrapping films.

    Science.gov (United States)

    Picque, D; Leclercq-Perlat, M N; Guillemin, H; Perret, B; Cattenoz, T; Provost, J J; Corrieu, G

    2010-12-01

    Four gas-permeable wrapping films exhibiting different degrees of water permeability (ranging from 1.6 to 500 g/m(2) per d) were tested to study their effect on soft-mold (Camembert-type) cheese-ripening dynamics compared with unwrapped cheeses. Twenty-three-day trials were performed in 2 laboratory-size (18L) respiratory-ripening cells under controlled temperature (6 ± 0.5°C), relative humidity (75 ± 2%), and carbon dioxide content (0.5 to 1%). The films allowed for a high degree of respiratory activity; no limitation in gas permeability was observed. The wide range of water permeability of the films led to considerable differences in cheese water loss (from 0.5 to 12% on d 23, compared with 15% for unwrapped cheeses), which appeared to be a key factor in controlling cheese-ripening progress. A new relationship between 2 important cheese-ripening descriptors (increase of the cheese core pH and increase of the cheese's creamy underrind thickness) was shown in relation to the water permeability of the wrapping film. High water losses (more than 10 to 12% on d 23) also were observed for unwrapped cheeses, leading to Camembert cheeses that were too dry and poorly ripened. On the other hand, low water losses (from 0.5 to 1% on d 23) led to over-ripening in the cheese underrind, which became runny as a result. Finally, water losses from around 3 to 6% on d 23 led to good ripening dynamics and the best cheese quality. This level of water loss appeared to be ideal in terms of cheese-wrapping film design. Copyright © 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  5. Design of the Waste Receiving and Processing (WRAP) 2A Facility

    International Nuclear Information System (INIS)

    Lamberd, D.L.; Weingardt, K.M.

    1994-07-01

    Radioactive and Hazardous Mixed Waste have accumulated at the US Department of Energy (DOE) Hanford Site in south-central Washington State. Future generated waste streams from planned facilities at the Hanford Site and off site will also generate solid wastes that contain both radiological and hazardous chemical components. Most of the low-level waste (LLW) in this category is generated in batches sized to be stored in smaller containers (mostly 55-gallon drums and boxes). To meet the Resource Conservation and Recovery Act (RCRA) Land Disposal Restrictions, most of this waste will need to be treated to meet disposal requirements. In general this treatment must include stabilization/solidification either as a sole method or as part of a treatment train. A planned DOE facility, the Waste Receiving and Processing (WRAP) Module 2A, Building 2337-W, is scoped to provide this required treatment for containerized contact-handle at sign d (CH), mixed low-level waste (MLLW) at the Hanford Site. The core processes in WRAP Module 2A include cement stabilization of particulate waste, polyethylene encapsulation (via extrusion) of particulate waste, and cement encapsulation (via vibratory infilling) of hard and soft debris. A conceptual design was prepared and issued in July 1992. Since that time, process development test activities and further design iterations have evolved into the optimized process and facility design presented in this paper. This paper will discuss the revised processing scheme, equipment configuration, and facility layout. The WRAP Module 2A will begin construction in 1996 after a detailed design effort and pilot testing activities

  6. Origins of the helical wrapping of phenyleneethynylene polymers about single-walled carbon nanotubes.

    Science.gov (United States)

    Von Bargen, Christopher D; MacDermaid, Christopher M; Lee, One-Sun; Deria, Pravas; Therien, Michael J; Saven, Jeffery G

    2013-10-24

    The highly charged, conjugated polymer poly[p-{2,5-bis(3-propoxysulfonicacidsodiumsalt)}phenylene]ethynylene (PPES) has been shown to wrap single-wall carbon nanotubes (SWNTs), adopting a robust helical superstructure. Surprisingly, PPES adopts a helical rather than a linear conformation when adhered to SWNTs. The complexes formed by PPES and related polymers upon helical wrapping of a SWNT are investigated using atomistic molecular dynamics (MD) simulations in the presence and absence of aqueous solvent. In simulations of the PPES/SWNT system in an aqueous environment, PPES spontaneously takes on a helical conformation. A potential of mean force, ΔA(ξ), is calculated as a function of ξ, the component of the end-to-end vector of the polymer chain projected on the SWNT axis; ξ is a monotonic function of the polymer's helical pitch. ΔA(ξ) provides a means to quantify the relative free energies of helical conformations of the polymer when wrapped about the SWNT. The aqueous system possesses a global minimum in ΔA(ξ) at the experimentally observed value of the helical pitch. The presence of this minimum is associated with preferred side chain conformations, where the side chains adopt conformations that provide van der Waals contact between the tubes and the aliphatic components of the side chains, while exposing the anionic sulfonates for aqueous solvation. The simulations provide a free energy estimate of a 0.2 kcal/mol/monomer preference for the helical over the linear conformation of the PPES/SWNT system in an aqueous environment.

  7. Picobubble enhanced column flotation of fine coal

    Energy Technology Data Exchange (ETDEWEB)

    Tao, D.; Yu, S.; Parekh, B.K. [University of Kentucky, Lexington, KY (United States). Mining Engineering

    2006-07-01

    The purpose is to study the effectiveness of picobubbles in the column flotation of -28 mesh fine coal particles. A flotation column with a picobubble generator was developed and tested for enhancing the recovery of ultrafine coal particles. The picobubble generator was designed using the hydrodynamic cavitation principle. A metallurgical and a steam coal were tested in the apparatus. The results show that the use of picobubbles in a 2in. flotation column increased the recovery of fine coal by 10 to 30%. The recovery rate varied with feed rate, collector dosage, and other column conditions. 40 refs., 8 figs., 2 tabs.

  8. Thermally stable dexsil-400 glass capillary columns

    International Nuclear Information System (INIS)

    Maskarinec, M.P.; Olerich, G.

    1980-01-01

    The factors affecting efficiency, thermal stability, and reproducibility of Dexsil-400 glass capillary columns for gas chromatography in general, and for polycyclic aromatic hydrocarbons (PAHs) in particular were investigated. Columns were drawn from Kimble KG-6 (soda-lime) glass or Kimox (borosilicate) glass. All silylation was carried out at 200 0 C. Columns were coated according to the static method. Freshly prepared, degassed solutions of Dexsil-400 in pentane or methylene chloride were used. Thermal stability of the Dexsil 400 columns with respect to gas chromatography/mass spectrometry (GC/MS) were tested. Column-to-column variability is a function of each step in the fabrication of the columns. The degree of etching, extent of silylation, and stationary phase film thickness must be carefully controlled. The variability in two Dexsil-400 capillary column prepared by etching, silylation with solution of hexa methyl disilazone (HMDS), and static coating is shown and also indicates the excellent selectivity of Dexsil-400 for the separation of alkylated aromatic compounds. The wide temperature range of Dexsil-400 and the high efficiency of the capillary columns also allow the analysis of complex mixtures with minimal prefractionation. Direct injection of a coal liquefaction product is given. Analysis by GC/MS indicated the presence of parent PAHs, alkylated PAHs, nitrogen and sulfur heterocycles, and their alkylated derivatives. 4 figures

  9. Laser surface wakefield in a plasma column

    International Nuclear Information System (INIS)

    Gorbunov, L.M.; Mora, P.; Ramazashvili, R.R.

    2003-01-01

    The structure of the wakefield in a plasma column, produced by a short intense laser pulse, propagating through a gas affected by tunneling ionization is investigated. It is shown that besides the usual plasma waves in the bulk part of the plasma column [see Andreev et al., Phys. Plasmas 9, 3999 (2002)], the laser pulse also generates electromagnetic surface waves propagating along the column boundary. The length of the surface wake wave substantially exceeds the length of the plasma wake wave and its electromagnetic field extends far outside the plasma column

  10. Dedicated Shift Wrap-up Time Does Not Improve Resident Sign-out Volume or Efficiency.

    Science.gov (United States)

    Jeanmonod, Rebecca K; Brook, Christopher; Winther, Mark; Pathak, Soma; Boyd, Molly

    2010-02-01

    Sign-out (SO) is a challenge to the emergency physician. Some training programs have instituted overlapping 9-hour shifts. The residents see patients for eight hours, and have one hour of wrap-up time. This hour helps them complete patient care, leaving fewer patients to sign-out. We examined whether this strategy impacts SO burden. This is a retrospective review of patients evaluated by emergency medicine (EM) residents working 9-hour (eight hours of patient care, one hour wrap-up time) and 12-hour shifts (12 hours patient care, no reserved time for wrap-up). Data were collected by reviewing the clinical tracker. A patient was assigned to the resident who initiated care and dictated the chart. SO was defined as any patient in the ED without disposition at change of shift. Patient turn-around-time (TAT) was also recorded. One-hundred sixty-one postgraduate-year-one resident (PGY1), 264 postgraduate-year-two resident (PGY2), and 193 postgraduate-year-three resident (PGY3) shifts were included. PGY1s signed out 1.9 patients per 12-hour shift. PGY2s signed out 2.3 patients on 12-hour shifts and 1.8 patients on 9-hour shifts. PGY3s signed out 2.1 patients on 12-hour shifts and 2.0 patients on 9-hour shifts. When we controlled for patients seen per hour, SO burden was constant by class regardless of shift length, with PGY2s signing out 18% of patients seen compared to 15% for PGY3s. PGY1s signed out 18% of patients seen. TAT for patients seen by PGY1s and PGY2s was similar, at 189 and 187 minutes, respectively. TAT for patients seen by PGY3s was significantly less at 175 minutes. The additional hour devoted to wrapping up patients in the ED had no affect on SO burden. The SO burden represented a fixed percentage of the total number of patients seen by the residents. PGY3s sign-out a smaller percentage of patients seen compared to other classes, and have faster TATs.

  11. Technical assessment of compliance with workplace air sampling requirements at WRAP

    International Nuclear Information System (INIS)

    HACKWORTH, M.F.

    1999-01-01

    The purpose of this Technical Assessment is to satisfy HSRCM-1, ''Hanford Site Radiological Control Manual'' Article 551.4 for a documented study of facility Workplace Air Monitoring (WAM) programs. HSRCM-1 is the primary guidance for radiological control at Waste Management Federal Services of Hanford, Inc. (WMH). The HSRCM-1 complies with Title 10. Part 835 of the Code of Federal Regulations (10CFR835). This document provides an evaluation of the compliance of the Waste Receiving and Processing facility (WRAP) WAM program to the criteria standards, requirements, and documents compliance with the requirements where appropriate. Where necessary, it also indicates changes needed to bring specific locations into compliance

  12. Capillary origami: spontaneous wrapping of a droplet with an elastic sheet.

    Science.gov (United States)

    Py, Charlotte; Reverdy, Paul; Doppler, Lionel; Bico, José; Roman, Benoît; Baroud, Charles N

    2007-04-13

    The interaction between elasticity and capillarity is used to produce three-dimensional structures through the wrapping of a liquid droplet by a planar sheet. The final encapsulated 3D shape is controlled by tailoring the initial geometry of the flat membrane. Balancing interfacial energy with elastic bending energy provides a critical length scale below which encapsulation cannot occur, which is verified experimentally. This length is found to depend on the thickness as h3/2, a scaling favorable to miniaturization which suggests a new way of mass production of 3D micro- or nanoscale objects.

  13. Coaxial Thermoplastic Elastomer-Wrapped Carbon Nanotube Fibers for Deformable and Wearable Strain Sensors

    KAUST Repository

    Zhou, Jian

    2018-01-22

    Highly conductive and stretchable fibers are crucial components of wearable electronics systems. Excellent electrical conductivity, stretchability, and wearability are required from such fibers. Existing technologies still display limited performances in these design requirements. Here, achieving highly stretchable and sensitive strain sensors by using a coaxial structure, prepared via coaxial wet spinning of thermoplastic elastomer-wrapped carbon nanotube fibers, is proposed. The sensors attain high sensitivity (with a gauge factor of 425 at 100% strain), high stretchability, and high linearity. They are also reproducible and durable. Their use as safe sensing components on deformable cable, expandable surfaces, and wearable textiles is demonstrated.

  14. Dedicated Shift Wrap-up Time Does Not Improve Resident Sign-out Volume or Efficiency

    Directory of Open Access Journals (Sweden)

    Jeanmonod, Rebecca K

    2010-02-01

    Full Text Available Objectives: Sign-out (SO is a challenge to the emergency physician. Some training programs have instituted overlapping 9-hour shifts. The residents see patients for eight hours, and have one hour of wrap-up time. This hour helps them complete patient care, leaving fewer patients to sign-out. We examined whether this strategy impacts SO burden.Methods: This is a retrospective review of patients evaluated by emergency medicine (EM residents working 9-hour (eight hours of patient care, one hour wrap-up time and 12-hour shifts (12 hours patient care, no reserved time for wrap-up. Data were collected by reviewing the clinical tracker. A patient was assigned to the resident who initiated care and dictated the chart. SO was defined as any patient in the ED without disposition at change of shift. Patient turn-around-time (TAT was also recorded.Results: One-hundred sixty-one postgraduate-year-one resident (PGY1, 264 postgraduate-year-two resident (PGY2, and 193 postgraduate-year-three resident (PGY3 shifts were included. PGY1s signed out 1.9 patients per 12-hour shift. PGY2s signed out 2.3 patients on 12-hour shifts and 1.8 patients on 9-hour shifts. PGY3s signed out 2.1 patients on 12-hour shifts and 2.0 patients on 9-hour shifts. When we controlled for patients seen per hour, SO burden was constant by class regardless of shift length, with PGY2s signing out 18% of patients seen compared to 15% for PGY3s. PGY1s signed out 18% of patients seen. TAT for patients seen by PGY1s and PGY2s was similar, at 189 and 187 minutes, respectively. TAT for patients seen by PGY3s was significantly less at 175 minutes.Conclusion: The additional hour devoted to wrapping up patients in the ED had no affect on SO burden. The SO burden represented a fixed percentage of the total number of patients seen by the residents. PGY3s sign-out a smaller percentage of patients seen compared to other classes, and have faster TATs. [West J Emerg Med. 2010; 11(1:35-39].

  15. [Constitutive correlations for wire-wrapped subchannel analysis under forced and mixed convection conditions]. Part II

    International Nuclear Information System (INIS)

    Cheng, S.K.; Todreas, N.E.

    1984-08-01

    A new version of the ENERGY series code, ENERGY-IV, was written for predicting coolant temperature distributions in wire-wrapped rod assemblies used in the Liquid Metal Fast Breeder Reactor. The ENERGY-IV Code is applicable to both steady-state forced and mixed convection operation for a single isolated assembly. (The SUPERENERGY Code, [Basehore (1980)] is applicable to core wide forced convection analysis.) ENERGY-IV is an empirical code designed to be fast running. Hence the core designer can use it as an inexpensive thermal hydraulic design or diagnosis tool

  16. Harmfulness Assessment of Moulding Sands with a Geopolymer Binder and a New Hardener, in An Aspect of the Emission of Substances from the Btex Group

    Directory of Open Access Journals (Sweden)

    Bobrowski A.

    2015-04-01

    Full Text Available The harmfulness assessment of moulding sands with a geopolymer binder and a new hardener, in an aspect of the emission of substances from the BTEX group, was performed. Within the expedience project the new series of hardeners for the inorganic GEOPOL binder was developed. Before the introduction of the new system of moulding sands it was necessary to estimate their influence on the environment. To this aim the gasses emission from moulding sands subjected to the influence of liquid cast iron was tested with regard to the content of the gases from the BTEX group (benzene, toluene, ethylbenzene and xylenes. For the comparison the analogous investigations of the up to now applied moulding sands with the geopolymer binder, were performed. It was found that both systems of moulding sands binding emit similar amounts of gases, as well as similar amounts of substances from the BTEX group. Moulding sands with the GEOPOL binder are much more environmentally friendly than moulding sands with organic binders. The content of the BTEX group substances in gases emitted from moulding sands with the GEOPOL binder was approximately 10-times lower than in case of the moulding sands with organic binders.

  17. Determination of the bulk modulus of hydroxycancrinite, a possible zeolitic precursor in geopolymers, by high-pressure synchrotron X-ray diffraction

    KAUST Repository

    Oh, Jae Eun

    2011-11-01

    Crystalline zeolitic materials, such as hydroxycancrinite, hydroxysodalite, herschelite and nepheline, are often synthesized from geopolymerization using fly-ash and solutions of NaOH at high temperatures. Comprised mainly of 6-membered aluminosilicate rings that act as basic building units, their crystal structures may provide insight into the reaction products formed in NaOH-activated fly ash-based geopolymers. Recent research indicates that the hydroxycancrinite and hydroxysodalite may play an important role as possible analogues of zeolitic precursor in geopolymers. Herein is reported a high pressure synchrotron study of the behavior of hydroxycancrinite exposed to pressures up to 6.1 GPa in order to obtain its bulk modulus. A refined equation of state for hydroxycancrinite yielded a bulk modulus of Ko = 46 ± 5 GPa (assuming Ko′ = 4.0) for a broad range of applied pressure. When low pressure values are excluded from the fit and only the range of 2.5 and 6.1 GPa is considered, the bulk modulus of hydroxycancrinite was found to be Ko = 46.9 ± 0.9 GPa (Ko′ = 4.0 ± 0.4, calculated). Comparison with the literature shows that all zeolitic materials possessing single 6-membered rings (i.e., hydroxycancrinite, sodalite and nepheline) have similar bulk moduli. © 2011 Elsevier Ltd. All rights reserved.

  18. Experimental study and modeling of gas diffusion through partially water saturated porous media. Application to Vycor glasses, geo-polymers and CEM V cement pastes

    International Nuclear Information System (INIS)

    Boher, C.

    2012-01-01

    This work documents the relationship that exists between the transfer properties of a material (pore size distribution, total porosity accessible to water, water saturation degree), and its diffusion coefficient. For this sake, materials having a quasi mono modal porosity are used: Vycor glasses and geo-polymers. We also use materials having a complex porosity: CEM V cement pastes. The use of Vycor glasses and geo-polymers allows quantifying the gas diffusion coefficient through materials having known pores size, as a function of their water saturation degree. The use of cement pastes allows checking if it is possible to decompose the diffusion coefficient of a complex porosity material, in an assembling of diffusion coefficients of quasi mono modal porosity materials. For this sake, the impact of pore network arrangement on the diffusion coefficient is studied in great details. This study is divided into three parts:1)Measurement of the geometric characteristics of materials porous network by means of the mercury intrusion porosimetry, water porosimetry, isotherms of nitrogen sorption / desorption, and water desorption tests. 2) Measurement of the materials diffusion coefficient, as a function of their relative humidity storage, and their water saturation degree. 3) Modeling the diffusion coefficient of the materials, and study the impact of the pore network (tortuosity, pores connection). (author) [fr

  19. The Role of Clay Swelling and Mineral Neoformation in the Stabilization of High Plasticity Soils Treated with the Fly Ash- and Metakaolin-Based Geopolymers

    Directory of Open Access Journals (Sweden)

    Mahmoud A. Mahrous

    2018-04-01

    Full Text Available In the southern U.S. states, expansive soils are frequently encountered, presenting an important hazard in geotechnical engineering. This research relies on mineralogical and geochemical clues to explain the swelling behavior of smectite-rich, high-plasticity soils, documented in a series of geomechanical swelling tests that were performed on the soils stabilized with the metakaolin (MKG and fly ash (FAG based geopolymers. These geopolymers were mixed with the soil at several concentration levels. The lowest swelling percentage was shown to correspond to the sample stabilized with 12% FAG and was attributed to the neoformation of calcium silicate hydrates that acted as a cementitious material, preventing the soil from expanding by occupying the pore space, thus binding the clay particles together. Conversely, the 12% MKG-stabilized soil exhibited enormous expansion, which was explained by montmorillonite swelling to the point that it gradually began to lose its structural periodicity. The relatively high abundance of the newly formed feldspathoids in MKG-treated samples is believed to have greatly contributed to the overall soil expansion. Finally, the cation exchange capacity tests showed that the percentage of Na+ and Ca2+, as well as the pH value, exercised strong control on the swelling behavior of smectitic soils.

  20. The Effect of Variation of Molarity of Alkali Activator and Fine Aggregate Content on the Compressive Strength of the Fly Ash: Palm Oil Fuel Ash Based Geopolymer Mortar

    Directory of Open Access Journals (Sweden)

    Iftekhair Ibnul Bashar

    2014-01-01

    Full Text Available The effect of molarity of alkali activator, manufactured sand (M-sand, and quarry dust (QD on the compressive strength of palm oil fuel ash (POFA and fly ash (FA based geopolymer mortar was investigated and reported. The variable investigated includes the quantities of replacement levels of M-sand, QD, and conventional mining sand (N-sand in two concentrated alkaline solutions; the contents of alkaline solution, water, POFA/FA ratio, and curing condition remained constant. The results show that an average of 76% of the 28-day compressive strength was found at the age of 3 days. The rate of strength development from 3 to 7 days was found between 12 and 16% and it was found much less beyond this period. The addition of 100% M-sand and QD shows insignificant strength reduction compared to mixtures with 100% N-sand. The particle angularity and texture of fine aggregates played a significant role in the strength development due to the filling and packing ability. The rough texture and surface of QD enables stronger bond between the paste and the fine aggregate. The concentration of alkaline solution increased the reaction rate and thus enhanced the development of early age strength. The use of M-sand and QD in the development of geopolymer concrete is recommended as the strength variation between these waste materials and conventional sand is not high.