Sample records for ammonia recycle percolation

  1. Bioethanol production from ammonia percolated wheat straw

    Microsoft Academic Search

    Minhee Han; Se-Kwon Moon; Yule Kim; Youngran Kim; Bongwoo Chung; Gi-Wook Choi

    2009-01-01

    This study examined the effectiveness of ammonia percolation pretreatment of wheat straw for ethanol production. Ground wheat\\u000a straw at a 10% (w\\/v) loading was pretreated with a 15% (v\\/v) ammonia solution. The experiments were performed at treatment\\u000a temperature of 50?170°C and residence time of 10?150 min. The solids treated with the ammonia solution showed high lignin\\u000a degradation and sugar availability.

  2. Pretreatment of lignocellulosic biomass by autohydrolysis and aqueous ammonia percolation

    Microsoft Academic Search

    Hyon Hee Yoon

    1998-01-01

    A two-stage biomass pretreatment process-a combination of autohydrolysis and aqueous ammonia percolation-was experimentally\\u000a studied as a method to remove and recover hemicellulose from lignocellulosic biomass. Hemicellulose was completely separated\\u000a from the biomass after 1 hr of autohydrolysis at 200‡C. As reaction temperature and\\/or time of autohydrolysis was increased\\u000a in the range of 170-200‡C and 1–2.5 hr, respectively, the amount of

  3. Ammonia recycling enables sustainable operation of bioelectrochemical systems.

    PubMed

    Cheng, Ka Yu; Kaksonen, Anna H; Cord-Ruwisch, Ralf

    2013-09-01

    Ammonium (NH4(+)) migration across a cation exchange membrane is commonly observed during the operation of bioelectrochemical systems (BES). This often leads to anolyte acidification (pH <5.5) and complete inactivation of biofilm electroactivity. Without using conventional pH controls (dosage of alkali or pH buffers), the present study revealed that anodic biofilm activity (current) could be sustained if recycling of ammonia (NH3) was implemented. A simple gas-exchange apparatus was designed to enable continuous recycling of NH3 (released from the catholyte at pH >10) from the cathodic headspace to the acidified anolyte. Results indicated that current (110 mA or 688 Am(-3) net anodic chamber volume) was sustained as long as the NH3 recycling path was enabled, facilitating continuous anolyte neutralization with the recycled NH3. Since the microbial current enabled NH4(+) migration against a strong concentration gradient (~10-fold), a novel way of ammonia recovery from wastewaters could be envisaged. PMID:23774293

  4. Recycled aqueous ammonia expansion (RAAE) pretreatment to improve enzymatic digestibility of corn stalks.

    PubMed

    Zhang, Chao; Pang, Feng; Li, Bing; Xue, Shulin; Kang, Yong

    2013-06-01

    A novel lignocellulose pretreatment method using aqueous ammonia for biofuel production was proposed in this study, which named recycled aqueous ammonia expansion (RAAE). Effects of temperature, pretreatment time, water to dry corn stalks loading and flow rate of aqueous ammonia on substrate enzymatic digestibility and sugar yield were investigated. Pretreatment temperature and time are important factors that affect RAAE process. Recirculation process could improve biomass digestibility and sugar yield compared with batch experiment. After RAAE pretreatment, about 70% of the lignin was removed, while more than 90% of the cellulose was preserved in the solids, the substrate crystallinity also increased because of the removal of amorphous portion. The maximum glucan enzymatic digestibility of pretreated biomass was 85.70%, which was obtained at 85°C, 11 min, 80% water to dry corn stalks loading and 1.5L/min aqueous ammonia flow rate. PMID:23624049

  5. AMMONIA

    EPA Science Inventory

    This document summarizes the available information on ammonia as it relates to its effects on man and his environment. Ammonia is a ubiquitous substance and is known widely as a household cleaning agent and as a fertilizer. It plays an important role in the nitrogen cycle--in the...

  6. Process modeling of an advanced NH? abatement and recycling technology in the ammonia-based CO? capture process.

    PubMed

    Li, Kangkang; Yu, Hai; Tade, Moses; Feron, Paul; Yu, Jingwen; Wang, Shujuan

    2014-06-17

    An advanced NH3 abatement and recycling process that makes great use of the waste heat in flue gas was proposed to solve the problems of ammonia slip, NH3 makeup, and flue gas cooling in the ammonia-based CO2 capture process. The rigorous rate-based model, RateFrac in Aspen Plus, was thermodynamically and kinetically validated by experimental data from open literature and CSIRO pilot trials at Munmorah Power Station, Australia, respectively. After a thorough sensitivity analysis and process improvement, the NH3 recycling efficiency reached as high as 99.87%, and the NH3 exhaust concentration was only 15.4 ppmv. Most importantly, the energy consumption of the NH3 abatement and recycling system was only 59.34 kJ/kg CO2 of electricity. The evaluation of mass balance and temperature steady shows that this NH3 recovery process was technically effective and feasible. This process therefore is a promising prospect toward industrial application. PMID:24850444

  7. Recycling

    NSDL National Science Digital Library

    sgp0002

    2010-03-27

    You will be learning all about recycling and asking questions as you learn more about recycling. Afterward, you will be making recycling bins that we will use in our classroom. Click on each of the different links and research about recycling. Find out what recycling is, what can be recycled, and why we should recycle. As you find information, add it to the "describing wheel" that is given to you by Ms. Pollak. Answer the main question: What is recycling? Come ...

  8. Recycling

    NSDL National Science Digital Library

    Miss Sykes

    2005-10-20

    Let\\'s learn how to reduce, reuse and recycle waste! BUILDING YOUR KNOWLEDGE ABOUT RECYCLING 1. Learn the abc\\'s of recycling found here A is for Air. Be sure to click on each letter of the alphabet and read what it stands for. 2. Read the Adventures of the Garbage Gremlin in this Comic Book. 3. Steel is used to build cars, household appliances and cans. Read ...

  9. Elimination of phenols, ammonia and cyanide in wash water from biomass gasification, and nitrogen recycling using planted trickling filters.

    PubMed

    Graber, Andreas; Skvarc, Robert; Junge-Berberovi?, Ranka

    2009-01-01

    Trickling filters were used to treat wash water from a wood gasifier. This wash water contained toxic substances such as ammonium, cyanide, phenols, and PAH. The goal was to develop a system that degraded toxic substances, and achieved full nitrification of ammonia. A 1 kW model wood gasifier plant delivered wash water for the experiments, which was standardised to a conductivity of 3 mS/cm by dilution. Toxicity was assessed by bacterial luminescence detection, germination test with cress (Lepidium sativum), and pot plants cultivated in a hydroponic setup irrigated continuously with the wastewater. Treatment experiments were done in both planted and unplanted trickling filters. Plant yield was similar to conventional hydroponic production systems. The trickling filters achieved complete detoxification of phenol, PAH and cyanide as well as full nitrification. The specific elimination rates were 100 g m(-3) Leca d(-1) for phenols and 90 g m(-3) Leca d(-1) for ammonium in planted systems. In unplanted trickling filters circulated for 63 h, phenol concentration decreased from 83.5 mg/L to 2.5 mg/L and cyanide concentration from 0.32 mg/L to 0.02 mg/L. PAH concentrations were reduced from 3,050 microg/L to 0.89 microg/L within 68 days. The assays demonstrated the feasibility of using the technique to construct a treatment system in a partially closed circulation for gasifier wash water. The principal advantage is to convert toxic effluents from biomass gasifiers into a non-toxic, nitrogen-rich fertiliser water, enabling subsequent use in plant production and thus income generation. However, the questions of long-term performance and possible accumulation of phenols and heavy metals in the produce still have to be studied. PMID:19955650

  10. Percolation Hamiltonians

    Microsoft Academic Search

    Peter Müller; Peter Stollmann

    2010-01-01

    \\u000a There has been quite some activity and progress concerning spectral asymptotics of random operators that are defined on percolation\\u000a subgraphs of different types of graphs. In this short survey we record some of these results and explain the necessary background\\u000a coming from different areas in mathematics: graph theory, group theory, probability theory and random operators.

  11. Explosive Percolation in Directed Networks

    E-print Network

    Anlage, Steven

    Explosive Percolation in Directed Networks Diego Alcala and Katherine Sytwu With Shane Squires ­ Directed and undirected networks ­ Percolation ­ Explosive percolation · Methodology · Results · Conclusion, infrastructure, etc. · Grow by the addition of links · New class of transitions: "explosive percolation" Taken

  12. Biotreatment of ammonia and butanal containing waste gases

    Microsoft Academic Search

    B. M. Weckhuysen; L. Vriens; H. Verachtert

    1994-01-01

    Abstract:The biological removal of ammonia and butanal in contaminated air was investigated by using, respectively, a laboratory-scale filter and a scrubber-filter combination. It was shown that ammonia can be removed with an elimination efficiency of 83% at a volumetric load of 100 m3·m–2·h–1 with 4–16?ppm of ammonia. During the experiment percolates were analysed for nitrate, nitrite, ammonium and pH. It

  13. Percolating under one roof

    E-print Network

    Miller, Joel C

    2015-01-01

    Many different concepts of percolation exist for networks. We show that bond percolation, site percolation, $k$-core percolation, and bootstrap percolation are all special cases of the Watts Threshold model. We show that the "heterogeneous $k$-core" and a corresponding heterogeneous bootstrap model are equivalent to one another and the Watts Threshold Model. A more recent model of a "Generalized Epidemic Process" is also shown to be a special case. Finally, we show that a natural generalization of the Watts Threshold Model is a special case of the Watts Threshold Model, and thus it is equivalent to the Watts Threshold Model as well.

  14. Ammonia Synthesis

    Microsoft Academic Search

    Noorhana Yahya; Poppy Puspitasari; Krzysztof Koziol; Pavia Guiseppe

    \\u000a Ammonia production is a very energy- and capital-intensive industry as it requires high temperature (400–500°C) and also high\\u000a pressure (150–300 bar) for its daily operations. Two moles of ammonia are obtained by reacting one mole of nitrogen and three\\u000a moles of hydrogen gases in the presence of conventional catalyst which is magnetite. The process to produce ammonia is known\\u000a as

  15. Ammonia Monitor

    NASA Technical Reports Server (NTRS)

    Sauer, Richard L. (Inventor); Akse, James R. (Inventor); Thompson, John O. (Inventor); Atwater, James E. (Inventor)

    1999-01-01

    Ammonia monitor and method of use are disclosed. A continuous, real-time determination of the concentration of ammonia in an aqueous process stream is possible over a wide dynamic range of concentrations. No reagents are required because pH is controlled by an in-line solid-phase base. Ammonia is selectively transported across a membrane from the process stream to an analytical stream to an analytical stream under pH control. The specific electrical conductance of the analytical stream is measured and used to determine the concentration of ammonia.

  16. PERCOLATION ON PENROSE TILINGS

    Microsoft Academic Search

    A. Hof

    ABSTRACT. In Bernoulli site percolation on Penrose tilings there are two natural definitions of the critical probability. This paper shows that they are equal on almost all Penrose tilings. It also shows that for almost all Penrose tilings the number,of infinite clusters is almost surely 0 or 1. The results generalize to percolation on a large class of aperiodic tilings

  17. Ammonia Test

    MedlinePLUS

    ... diagnose the cause of a coma of unknown origin or to help support the diagnosis of Reye's ... clearing them. Normal concentrations of ammonia do not rule out hepatic encephalopathy . Other wastes can contribute to ...

  18. Ammonia - blood

    MedlinePLUS

    ... is most commonly used to diagnose and monitor hepatic encephalopathy , a severe liver disease. Ammonia (NH3) is ... Elsevier; 2011:chap 149. Nevah MI, Fallon MB. Hepatic encephalopathy, hepatorenal syndrome, hepatopulmonary syndrome, and systemic complications ...

  19. Fat fractal percolation and k-fractal percolation Erik Bromana

    E-print Network

    Meester, Ronald

    Fat fractal percolation and k-fractal percolation Erik Bromana Tim van de Brugb Federico Camiab fractal percolation model. In the k-fractal percolation model, the d-dimensional unit cube is divided . This is analogous to the result of Falconer and Grimmett in [8] that the critical value for Mandelbrot fractal

  20. Development of Vapor-Phase Catalytic Ammonia Removal System

    NASA Technical Reports Server (NTRS)

    Flynn, Michael; Fisher, John; Kiss, Mark; Borchers, Bruce; Tleimat, Badawi; Tleimat, Maher; Quinn, Gregory; Fort, James; Nalette, Tim; Baker, Gale; Genovese, Joseph

    2007-01-01

    A report describes recent accomplishments of a continuing effort to develop the vapor-phase catalytic ammonia removal (VPCAR) process for recycling wastewater for consumption by humans aboard a spacecraft in transit to Mars.

  1. Percolation on Sparse Networks

    NASA Astrophysics Data System (ADS)

    Karrer, Brian; Newman, M. E. J.; Zdeborová, Lenka

    2014-11-01

    We study percolation on networks, which is used as a model of the resilience of networked systems such as the Internet to attack or failure and as a simple model of the spread of disease over human contact networks. We reformulate percolation as a message passing process and demonstrate how the resulting equations can be used to calculate, among other things, the size of the percolating cluster and the average cluster size. The calculations are exact for sparse networks when the number of short loops in the network is small, but even on networks with many short loops we find them to be highly accurate when compared with direct numerical simulations. By considering the fixed points of the message passing process, we also show that the percolation threshold on a network with few loops is given by the inverse of the leading eigenvalue of the so-called nonbacktracking matrix.

  2. Price percolation model

    NASA Astrophysics Data System (ADS)

    Kanai, Yasuhiro; Abe, Keiji; Seki, Yoichi

    2015-06-01

    We propose a price percolation model to reproduce the price distribution of components used in industrial finished goods. The intent is to show, using the price percolation model and a component category as an example, that percolation behaviors, which exist in the matter system, the ecosystem, and human society, also exist in abstract, random phenomena satisfying the power law. First, we discretize the total potential demand for a component category, considering it a random field. Second, we assume that the discretized potential demand corresponding to a function of a finished good turns into actual demand if the difficulty of function realization is less than the maximum difficulty of the realization. The simulations using this model suggest that changes in a component category's price distribution are due to changes in the total potential demand corresponding to the lattice size and the maximum difficulty of realization, which is an occupation probability. The results are verified using electronic components' sales data.

  3. Evaluation of a chemical scrubber for the removal of gaseous contaminants from recycled air

    Microsoft Academic Search

    E. V. Jeszenka; W. J. White; C. M. Lang; H. C. Hughes

    1981-01-01

    A chemical scrubber was evaluated for its ability to remove two gases with differing water solubilities from recycled air. Operating parameters of the scrubber were also evaluated and included effect on air temperature and humidity. Ammonia, which has a high water solubility, was completely removed from the recycled air. Even when ammonia was continuously infused into the isolator at the

  4. Hanford recycling

    SciTech Connect

    Leonard, I.M.

    1996-09-01

    This paper is a study of the past and present recycling efforts on the Hanford site and options for future improvements in the recycling program. Until 1996, recycling goals were voluntarily set by the waste generators: this year, DOE has imposed goals for all its sites to accomplish by 1999. Hanford is presently meeting the voluntary site goals, but may not be able to meet all the new DOE goals without changes to the program. Most of these new DOE goals are recycling goals: * Reduce the generation of radioactive (low-level) waste from routine operations 50 percent through source reduction and recycling. * Reduce the generation of low-level mixed waste from routine operations 50 percent through source reduction and recycling. * Reduce the generation of hazardous waste from routine operations 50 percent through source reduction and recycling. * Recycle 33 percent of the sanitary waste from all operations. * Increase affirmative procurement of EPA-designated recycled items to 100 percent. The Hanford recycling program has made great strides-there has been a 98 percent increase in the amount of paper recycled since its inception in 1990. Hanford recycles paper, chemicals cardboard, tires, oil, batteries, rags, lead weights, fluorescent tubes, aerosol products, concrete, office furniture, computer software, drums, toner cartridges, and scrap metal. Many other items are recycled or reused by individual groups on a one time basis without a formal contract. Several contracts are closed-loop contracts which involve all parts of the recycle loop. Considerable savings are generated from recycling, and much more is possible with increased attention and improvements to this program. General methods for improving the recycling program to ensure that the new goals can be met are: a Contract and financial changes 0 Tracking database and methods improvements 0 Expanded recycling efforts. Specifically, the Hanford recycling program would be improved by: 0 Establishing one overall DOE recycling contract at the Hanford site and a central group to control the contract. 0 Using a BOA or MTS contract as a way to get proceeds from recycling back to site facilities to provide incentives for recycling. . Upgrading tracking mechanisms to track and recycle construction waste which is presently buried in onsite pits. . Establishing contract performance measures which hold each project accountable for specific waste reduction goals. * Recycling and reusing any material or equipment possible as buildings are dismantled.

  5. RECYCLING TODAY

    NSDL National Science Digital Library

    Miss Smith

    2010-12-03

    We have probably heard of recycling but what is it really and why is it so improtant to do? Please answer the questions below as well as visiting the different websites to explore what recycling really is. Form groups of 4 and explore the following websites as well as answer the questions which follow. The first website is of Recycle City where you will be exploring the City and how they recycle. Recyle City Why Recycling is Important Now please answer the following questions on paper. 1. What are the 3 R's? Explain in further ...

  6. Electrical Percolation Based Biosensors

    PubMed Central

    Bruck, Hugh Alan; Yang, Minghui; Kostov, Yordan; Rasooly, Avraham

    2013-01-01

    A new approach to label free biosensing has been developed based on the principle of “electrical percolation”. In electrical percolation, long-range electrical connectivity is formed in randomly oriented and distributed systems of discrete elements. By applying this principle to biological interactions, it is possible to measure biological components both directly and electronically. The main element for electrical percolation biosensor is the biological semiconductor (BSC) which is a multi-layer 3-D carbon nanotube-antibody network. In the BSC, molecular interactions, such as binding of antigens to the antibodies, disrupt the network continuity causing increased resistance of the network. BSCs can be fabricated by immobilizing conducting elements, such as pre-functionalized single-walled carbon nanotubes (SWNTs)-antibody complex, directly onto a substrate, such as a Poly(methyl methacrylate) (PMMA) surface (also known as plexi-glass or Acrylic). BSCs have been demonstrated for direct (label-free) electronic measurements of antibody-antigen binding using SWNTs. If the concentration of the SWNT network is slightly above the electrical percolation threshold, then binding of a specific antigen to the pre-functionalized SWNT dramatically increases the electrical resistance due to changes in the tunneling between the SWNTs. Using anti-Staphylococcal enterotoxin B (SEB) IgG as a “gate” and SEB as an “actuator”, it was demonstrated that the BSC was able to detect SEB at concentrations of 1 ng/ml. Based on this concept, an automated configuration for BSCs is described here that enables real time continuous detection. The new BSC configuration may permit assembly of multiple sensors on the same chip to create “Biological Central Processing Units (CPUs)” with multiple biological elements, capable of processing and sorting out information on multiple analytes simultaneously. PMID:24041756

  7. Space-filling percolation.

    PubMed

    Chakraborty, Abhijit; Manna, S S

    2014-03-01

    A region of two-dimensional space has been filled randomly with a large number of growing circular disks allowing only a "slight" overlapping among them just before their growth stops. More specifically, each disk grows from a nucleation center that is selected at a random location within the uncovered region. The growth rate ? is a continuously tunable parameter of the problem which assumes a specific value while a particular pattern of disks is generated. When a growing disk overlaps for the first time with at least one other disk, its growth is stopped and is said to be frozen. In this paper we study the percolation properties of the set of frozen disks. Using numerical simulations we present evidence for the following: (i) The order parameter appears to jump discontinuously at a certain critical value of the area coverage; (ii) the width of the window of the area coverage needed to observe a macroscopic jump in the order parameter tends to vanish as ??0; and on the contrary (iii) the cluster size distribution has a power-law-decaying functional form. While the first two results are the signatures of a discontinuous transition, the third result is indicative of a continuous transition. Therefore we refer to this transition as a sharp but continuous transition similar to what has been observed in the recently introduced Achlioptas process of explosive percolation. It is also observed that in the limit of ??0, the critical area coverage at the transition point tends to unity, implying that the limiting pattern is space filling. In this limit, the fractal dimension of the pore space at the percolation point has been estimated to be 1.42(10) and the contact network of the disk assembly is found to be a scale-free network. PMID:24730786

  8. Mean quantum percolation

    E-print Network

    Charles Bordenave; Arnab Sen; Balint Virag

    2013-08-17

    We study the spectrum of adjacency matrices of random graphs. We develop two techniques to lower bound the mass of the continuous part of the spectral measure or the density of states. As an application, we prove that the spectral measure of bond percolation in the two dimensional lattice contains a non-trivial continuous part in the supercritical regime. The same result holds for the limiting spectral measure of a supercritical Erdos-Renyi graph and for the spectral measure of a unimodular random tree with at least two ends. We give examples of random graphs with purely continuous spectrum.

  9. Gas percolation through sand

    NASA Astrophysics Data System (ADS)

    Proud, W. G.

    2014-05-01

    Previous research has determined the shock properties of quartz sand. The effect of the physical processes occurring with varying moisture content and particle size were shock presented. In this study the same quartz sand, in a column is subjected to blast waves over a range of pressure. The diagnostics used are pressure sensors and high-speed photography. The effect of grain size on propagation time and the effect of moisture content are determined. Aspects of particle and liquid movement are also discussed. While the velocity of the percolation through the bed is primarily controlled by grain size the effect of moisture and liquids reveals a more complex dependence.

  10. Scaling theory of percolation clusters

    Microsoft Academic Search

    D. Stauffer

    1979-01-01

    For beginners: This review tries to explain percolation through the cluster properties; it can also be used as an introduction to critical phenomena at other phase transitions for readers not familiar with scaling theory. In percolation each site of a periodic lattice is randomly occupied with probability p or empty with probability 1-p. An s-cluster is a group of s

  11. Weak percolation on multiplex networks.

    PubMed

    Baxter, Gareth J; Dorogovtsev, Sergey N; Mendes, José F F; Cellai, Davide

    2014-04-01

    Bootstrap percolation is a simple but nontrivial model. It has applications in many areas of science and has been explored on random networks for several decades. In single-layer (simplex) networks, it has been recently observed that bootstrap percolation, which is defined as an incremental process, can be seen as the opposite of pruning percolation, where nodes are removed according to a connectivity rule. Here we propose models of both bootstrap and pruning percolation for multiplex networks. We collectively refer to these two models with the concept of "weak" percolation, to distinguish them from the somewhat classical concept of ordinary ("strong") percolation. While the two models coincide in simplex networks, we show that they decouple when considering multiplexes, giving rise to a wealth of critical phenomena. Our bootstrap model constitutes the simplest example of a contagion process on a multiplex network and has potential applications in critical infrastructure recovery and information security. Moreover, we show that our pruning percolation model may provide a way to diagnose missing layers in a multiplex network. Finally, our analytical approach allows us to calculate critical behavior and characterize critical clusters. PMID:24827287

  12. Is inhaled ammonia

    Microsoft Academic Search

    Kaye H. Kilburn

    Describes how a large ammonia release exposed about 150 nearby residents to this irritating gas and sent seven to hospital emergency rooms. Six weeks later the 41 most symptomatic people completed questionnaires and had physical examinations. The 12 most impaired had subsequent neurobehavioral testing to see if exogenous ammonia was toxic to the brain as is endogenous ammonia in hepatic

  13. Self Healing Percolation

    NASA Astrophysics Data System (ADS)

    Scala, Antonio

    2015-03-01

    We introduce the concept of self-healing in the field of complex networks modelling; in particular, self-healing capabilities are implemented through distributed communication protocols that exploit redundant links to recover the connectivity of the system. Self-healing is a crucial in implementing the next generation of smart grids allowing to ensure a high quality of service to the users. We then map our self-healing procedure in a percolation problem and analyse the interplay between redundancies and topology in improving the resilience of networked infrastructures to multiple failures. We find exact results both for planar lattices and for random lattices, hinting the role of duality in the design of resilient networks. Finally, we introduce a cavity method approach to study the recovery of connectivity after damage in self-healing networks. CNR-PNR National Project ``Crisis-Lab,'' EU HOME/2013/CIPS/AG/4000005013 project CI2C and EU FET project MULTIPLEX nr.317532.

  14. Ideas: Recycling.

    ERIC Educational Resources Information Center

    Chessin, Debby A.; And Others

    1994-01-01

    Presents classroom ideas focusing on connections among mathematics, concern for the environment, and conservation of natural resources, including decomposition, water conservation, packaging materials, use of manufactured cans, and recycling. Includes reproducible student worksheets. (MKR)

  15. Recycle City

    NSDL National Science Digital Library

    Recycling made fun. The Environmental Protection Agency's Recycle City Web site offers students an interactive way to learn how recycling can affect their environment. Users can click any part of the cartoon drawing of the city to learn about that particular building or site and what can be done to decrease waste. The site also contains a more involved exercise called the Dumptown game, where visitors click on City Hall to view various recycling programs and choose the program(s) the city will implement. Once implemented, that activity can be seen taking place in Dumptown. Although the Dumptown exercise may require the help of a teacher to navigate for younger students, both exercises are excellent for K-12 teachers and students.

  16. Extreme Recycling

    E-print Network

    Hacker, Randi

    2009-01-14

    Broadcast Transcript: Singing the recycling blues because you have to separate your chipboard from your newspaper, your steel from your aluminum, your #1 from your #2 plastic? Pantywaists! The residents of Kamikatsu, Japan have no fewer than 34...

  17. Recycled Towers

    NSDL National Science Digital Library

    Integrated Teaching and Learning Program,

    Students learn about material reuse by designing and building the strongest and tallest towers they can, using only recycled materials. They follow design constraints and build their towers to withstand earthquake and high wind simulations.

  18. Glass recycling

    SciTech Connect

    Dalmijn, W.L.; Houwelingen, J.A. van [Delft Univ. of Technology (Netherlands). Faculty of Mining and Petroleum Engineering

    1995-12-31

    Glass recycling in the Netherlands has grown from 10,000 to 300,000 tonnes per annum. The various advantages and problems of the glass cycle with reference to the state of the art in the Netherlands is given. Special attention is given to new technologies for the automated sorting of cullet with detection systems. In Western Europe the recycling of glass has become a success story. Because of this, the percentage of glass cullet used in glass furnaces has increased. To meet the quality demands of the glass industry, automated sorting for the removal of stones, non-ferrous metals and other impurities had to be developed and incorporated in glass recycling plants. In Holland, Germany and other countries, the amount of glass collected has reached a level that color-sorting becomes necessary to avoid market saturation with mixed cullet. Recently, two systems for color-sorting have been developed and tested for the separation of bottles and cullet in the size range of 20--50 mm. With the increased capacity of the new glass recycling plants, 120,000--200,000 tpy, the quality systems have also to be improved and automated. These quality control systems are based on the automated sorting technology developed earlier for the glass recycling plants. The data obtained are automatically processed and printed. The sampling system and its relation to the theory of Gy will be described. Results of both developments in glass recycling plants will be described.

  19. Stacked triangular lattice: Percolation properties

    NASA Astrophysics Data System (ADS)

    Schrenk, K. J.; Araújo, N. A. M.; Herrmann, H. J.

    2013-03-01

    The stacked triangular lattice has the shape of a triangular prism. In spite of being considered frequently in solid-state physics and materials science, its percolation properties have received little attention. We investigate several nonuniversal percolation properties on this lattice using Monte Carlo simulation. We show that the percolation threshold is pcbond=0.18602±0.00002 for bonds and pcsite=0.26240±0.00005 for sites. The number of clusters at the threshold per site is ncbond=0.28458±0.00005 and ncsite=0.03998±0.00005. The stacked triangular lattice is a convenient choice to study the RGB model [Schrenk , Sci. Rep.10.1038/srep00751 2, 751 (2012)]. We present results on this model and its scaling behavior at the percolation threshold.

  20. Rigid-floppy percolation threshold.

    PubMed

    Avramov, I

    2009-05-27

    The mathematical limits for the percolation of rigid and floppy clusters throughout continuous networks are considered. Results are compared to the previous prediction of Thorpe based on the assumption that the threshold condition is the equality of degrees of freedom and the number of constraints. It is demonstrated that, in two-dimensional systems, the thresholds values predicted here and in the Thorpe model are relatively close. Our investigation demonstrates that, in 3D, there is a range of strong bond concentrations in which both floppy and rigid clusters percolate simultaneously. Depending on the particular property, either the rigid or the floppy cluster plays the key role. This explains the existence of solid electrolytes. They are solid because of the percolating rigid skeleton and at the same time have high conductivity controlled by the floppy cluster that also percolates. PMID:21825548

  1. Predicting percolation thresholds in networks

    NASA Astrophysics Data System (ADS)

    Radicchi, Filippo

    2015-01-01

    We consider different methods, which do not rely on numerical simulations of the percolation process, to approximate percolation thresholds in networks. We perform a systematic analysis on synthetic graphs and a collection of 109 real networks to quantify their effectiveness and reliability as prediction tools. Our study reveals that the inverse of the largest eigenvalue of the nonbacktracking matrix of the graph often provides a tight lower bound for true percolation threshold. However, in more than 40 % of the cases, this indicator is less predictive than the naive expectation value based solely on the moments of the degree distribution. We find that the performance of all indicators becomes worse as the value of the true percolation threshold grows. Thus, none of them represents a good proxy for the robustness of extremely fragile networks.

  2. Sharp thresholds in Bootstrap percolation

    NASA Astrophysics Data System (ADS)

    Balogh, József; Bollobás, Béla

    2003-08-01

    In the standard bootstrap percolation on the d-dimensional grid Gnd, in the initial position each of the nd sites is occupied with probability p and empty with probability 1- p, independently of the state of every other site. Once a site is occupied, it remains occupied for ever, while an empty site becomes occupied if at least two of its neighbours are occupied. If at the end of the process every site is occupied, we say that the (initial) configuration percolates. By making use of a theorem of Friedgut and Kalai (Proc. Amer. Math. Soc. 124 (1996) 2993), we shall show that the threshold function of the percolation is sharp. We shall prove similar results for three other models of bootstrap percolation as well.

  3. Toxicity of ammonia in pore-water and in the water column to freshwater benthic invertebrates

    SciTech Connect

    Whiteman, F.W.; Kahl, M.D.; Rau, D.M.; Balcer, M.D. [Univ. of Wisconsin, Superior, WI (United States). Lake Superior Research Inst.; Ankley, G.T. [Environmental Protection Agency, Duluth, MN (United States)

    1994-12-31

    Ammonia has been mentioned as both a primary toxicant and a factor that can produce false positive results in laboratory sediment tests using benthic invertebrates. This study developed a sediment dosing system that percolates an ammonia solution through sediment to achieve target porewater ammonia concentrations that remain stable over four and ten day spiked sediment tests. Ten day flow-through water-only tests and ten day spiked sediment tests were used to determine the toxicity of ammonia in the water column and in the sediment pore-water to the oligochaete Lumbriculus variegatus and the midge Chironomus tentans. Four-day tests were run with the amphipod Hyalella azteca. The relationship between water column ammonia toxicity and sediment pore-water ammonia toxicity is influenced by the organism`s association with the sediment. For Lumbriculus variegatus and Chironomus tentans that burrow into the sediment and are in direct contact with the porewater, the pore-water LC50 for ammonia is 30--40% higher than the water-only LC50 for each species. Hyalella azteca is epibenthic and avoids ammonia spiked sediment, thus ammonia in the water column is considerably more toxic than the pore-water ammonia with the porewater LC50 about 800% higher than the water only LC50.

  4. Utility of Recycled Bedding for Laboratory Rodents

    PubMed Central

    Miyamoto, Toru; Li, Zhixia; Kibushi, Tomomi; Okano, Shinya; Yamasaki, Nakamichi; Kasai, Noriyuki

    2009-01-01

    Animal facilities generate a large amount of used bedding containing excrement as medical waste. We developed a recycling system for used bedding that involves soft hydrothermal processing. In this study, we examined the effects of bedding type on growth, hematologic and serum biochemical values, and organ weights of female and male mice reared on either recycled or fresh bedding from 3 to 33 wk of age. Neither growth nor physiology differed between mice housed on recycled bedding compared with fresh bedding. When 14-wk-old mice were bred, litter size and total number of weaned pups showed no significant differences between animals raised on recycled or fresh bedding. Because bedding type influences the environment within cages and animal rooms, we evaluated particulate and ammonia data from cages and animal rooms. Values were significantly lower from cages and rooms that used recycled bedding than from those using fresh bedding, thus indicating that recycled bedding has the potential to improve the environment within both cages and animal rooms. Overall, this study revealed that recycled bedding is an excellent material for use in housing laboratory rodents. Specifically, recycled bedding may reduce medical waste and maintain healthy environments within cages and animal rooms. PMID:19653951

  5. Tire Recycling

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Cryopolymers, Inc. tapped NASA expertise to improve a process for recycling vehicle tires by converting shredded rubber into products that can be used in asphalt road beds, new tires, hoses, and other products. In conjunction with the Southern Technology Applications Center and Stennis Space Center, NASA expertise in cryogenic fuel-handling needed for launch vehicle and spacecraft operations was called upon to improve the recycling concept. Stennis advised Cryopolymers on the type of equipment required, as well as steps to reduce the amount of liquid nitrogen used in the process. They also guided the company to use more efficient ways to control system hardware. It is estimated that more than 300 million tires nationwide are produced per year. Cryopolymers expects to reach a production rate of 5,000 tires recycled per day.

  6. Development of ammonia synthesis

    Microsoft Academic Search

    Poppy Puspitasari; Noorhana Yahya

    2011-01-01

    Ammonia production is a high energy and capital-intensive industry as it obliges high temperature (400–500°C) and also high pressure (150–300 bar) for its daily processes. Two moles of ammonia are obtained by reacting one mole of nitrogen and three moles of hydrogen gases in the existence of conventional catalyst which are magnetite (Fe3O4). The process to produce ammonia is known

  7. Endocytic recycling

    Microsoft Academic Search

    Frederick R. Maxfield; Timothy E. McGraw

    2004-01-01

    After endocytosis, most membrane proteins and lipids return to the cell surface, but some membrane components are delivered to late endosomes or the Golgi. We now understand that the pathways taken by internalized molecules that eventually recycle to the cell surface can be surprisingly complex and can involve a series of sorting events that occur in several organelles. The molecular

  8. Steel Recycling Institute (SRI)

    NSDL National Science Digital Library

    1998-01-01

    The Steel Recycling Institute (SRI) provides information and statistics on steel recycling; it was founded by a group of steel companies and the American Iron and Steel Institute (AISI). Originally a grassroots effort focused only on the recycling of steel cans, the SRI now promotes the recycling of all steel products. The SRI homepage provides online access to its three publications, The Dockside Recycler, The Recycling Magnet, and The Appliance Recycler. Recycling information is divided into four categories: cans, cars, appliances, and construction material. Users can use the recycling database to find the nearest steel recycling location. Links provides a large list of both commercial and non-commercial steel sites.

  9. ParadigmParadigm Concrete RecyclingConcrete Recycling

    E-print Network

    ParadigmParadigm Concrete RecyclingConcrete Recycling #12;Recycled ConcreteRecycled Concrete the recycle mix #12;Uses of Recycled ConcreteUses of Recycled Concrete 1.1. Aggregate BaseAggregate Base 2Two Lift Construction #12;II--35, Oklahoma35, Oklahoma ­­ Payne CountyPayne County Recycled Concrete MixRecycled

  10. Precipitation Recycling

    NASA Technical Reports Server (NTRS)

    Eltahir, Elfatih A. B.; Bras, Rafael L.

    1996-01-01

    The water cycle regulates and reflects natural variability in climate at the regional and global scales. Large-scale human activities that involve changes in land cover, such as tropical deforestation, are likely to modify climate through changes in the water cycle. In order to understand, and hopefully be able to predict, the extent of these potential global and regional changes, we need first to understand how the water cycle works. In the past, most of the research in hydrology focused on the land branch of the water cycle, with little attention given to the atmospheric branch. The study of precipitation recycling which is defined as the contribution of local evaporation to local precipitation, aims at understanding hydrologic processes in the atmospheric branch of the water cycle. Simply stated, any study on precipitation recycling is about how the atmospheric branch of the water cycle works, namely, what happens to water vapor molecules after they evaporate from the surface, and where will they precipitate?

  11. Nonlocal product rules for percolation

    NASA Astrophysics Data System (ADS)

    Reis, Saulo D. S.; Moreira, André A.; Andrade, José S., Jr.

    2012-04-01

    Despite original claims of a first-order transition in the product rule model proposed by Achlioptas [ScienceSCIEAS0036-807510.1126/science.1167782 323, 1453 (2009)], recent studies indicate that this percolation model, in fact, displays a continuous transition. The distinctive scaling properties of the model at criticality, however, strongly suggest that it should belong to a different universality class than ordinary percolation. Here we introduce a generalization of the product rule that reveals the effect of nonlocality on the critical behavior of the percolation process. Precisely, pairs of unoccupied bonds are chosen according to a probability that decays as a power law of their Manhattan distance, and only that bond connecting clusters whose product of their sizes is the smallest becomes occupied. Interestingly, our results for two-dimensional lattices at criticality shows that the power-law exponent of the product rule has a significant influence on the finite-size scaling exponents for the spanning cluster, the conducting backbone, and the cutting bonds of the system. In all three cases, we observe a clear transition from ordinary to (nonlocal) explosive percolation exponents.

  12. Molecular Structure of Ammonia

    NSDL National Science Digital Library

    2006-05-02

    Ammonia is a non-ionic colorless gas at ambient temperatures and a hydrogen bonding liquid at 240 Kelvin that has the remarkable ability to dissolve alkali metals. Ammonia is a Lewis base and is readily absorbed by water to form small amounts of ammonium hydroxide (pKb = 4.74). Naturally, ammonia has its sources in the biosphere (the nitrogen cycle) and is a trace gas in air and a source of ammonium ions in rain and atmospheric aerosols. Ammonia is prepared industrially by the Haber-Bosch process in quantities exceeding 120 million metric tons per year. In this process, ammonia gas is formed when hydrogen and nitrogen (3:1) are compressed to pressures of 200 atm and passed over an iron catalyst at 380-450 degrees C. Much of the ammonia produced this way (85%) is used as fertilizers on crops, a significant portion of which leaches from croplands into streams causing nitrate pollution and eutrophication of waterways (e.g., dead-zone in the Gulf of Mexico). Other sources of ammonia include combustion (coal and biomass burning) and from bacterial decomposition of animal excreta.

  13. Percolation in models of thin film depositions.

    PubMed

    Lebovka, N I; Manna, S S; Tarafdar, S; Teslenko, N

    2002-12-01

    We have studied the percolation behavior of deposits for different (2+1)-dimensional models of surface layer formation. The mixed model of deposition was used, where particles were deposited selectively according to the random (RD) and ballistic (BD) deposition rules. In the mixed one-component models with deposition of only conducting particles, the mean height of the percolation layer (measured in monolayers) grows continuously from 0.898 32 for the pure RD model to 2.605 for the pure BD model, but the percolation transition belongs to the same universality class, as in the two-dimensional (2D) random percolation problem. In two-component models with deposition of conducting and isolating particles, the percolation layer height approaches infinity as concentration of the isolating particles becomes higher than some critical value. The crossover transition from 2D to 3D percolation was observed with increase of the percolation layer height. PMID:12513374

  14. Percolation in models of thin film depositions

    NASA Astrophysics Data System (ADS)

    Lebovka, N. I.; Manna, S. S.; Tarafdar, S.; Teslenko, N.

    2002-12-01

    We have studied the percolation behavior of deposits for different (2+1)-dimensional models of surface layer formation. The mixed model of deposition was used, where particles were deposited selectively according to the random (RD) and ballistic (BD) deposition rules. In the mixed one-component models with deposition of only conducting particles, the mean height of the percolation layer (measured in monolayers) grows continuously from 0.898 32 for the pure RD model to 2.605 for the pure BD model, but the percolation transition belongs to the same universality class, as in the two-dimensional (2D) random percolation problem. In two-component models with deposition of conducting and isolating particles, the percolation layer height approaches infinity as concentration of the isolating particles becomes higher than some critical value. The crossover transition from 2D to 3D percolation was observed with increase of the percolation layer height.

  15. Combustion Byproducts Recycling Consortium

    SciTech Connect

    Ziemkiewicz, Paul; Vandivort, Tamara; Pflughoeft-Hassett, Debra; Chugh, Y Paul; Hower, James

    2008-08-31

    Each year, over 100 million tons of solid byproducts are produced by coal-burning electric utilities in the United States. Annual production of flue gas desulfurization (FGD) byproducts continues to increase as the result of more stringent sulfur emission restrictions. In addition, stricter limits on NOx emissions mandated by the 1990 Clean Air Act have resulted in utility burner/boiler modifications that frequently yield higher carbon concentrations in fly ash, which restricts the use of the ash as a cement replacement. Controlling ammonia in ash is also of concern. If newer, “clean coal” combustion and gasification technologies are adopted, their byproducts may also present a management challenge. The objective of the Combustion Byproducts Recycling Consortium (CBRC) is to develop and demonstrate technologies to address issues related to the recycling of byproducts associated with coal combustion processes. A goal of CBRC is that these technologies, by the year 2010, will lead to an overall ash utilization rate from the current 34% to 50% by such measures as increasing the current rate of FGD byproduct use and increasing in the number of uses considered “allowable” under state regulations. Another issue of interest to the CBRC would be to examine the environmental impact of both byproduct utilization and disposal. No byproduct utilization technology is likely to be adopted by industry unless it is more cost-effective than landfilling. Therefore, it is extremely important that the utility industry provide guidance to the R&D program. Government agencies and privatesector organizations that may be able to utilize these materials in the conduct of their missions should also provide input. The CBRC will serve as an effective vehicle for acquiring and maintaining guidance from these diverse organizations so that the proper balance in the R&D program is achieved.

  16. Ammonia Release on ISS

    NASA Technical Reports Server (NTRS)

    Macatangay, Ariel

    2009-01-01

    Crew: Approximately 53% metabolic load Product of protein metabolism Limit production of ammonia by external regulation NOT possbile Payloads Potential source Scientific experiments Thorough safety review ensures sufficient levels of containment

  17. Ammonia and sediment toxicity

    SciTech Connect

    Ogle, R.S.; Hansen, S.R. [S.R. Hansen and Associates, Concord, CA (United States)

    1994-12-31

    Ammonia toxicity to aquatic organisms has received considerable study, with most of these studies focusing on water column organisms. However, with the development and implementation of sediment (and pore water) toxicity tests, the toxicity of ammonia to benthic infauna and other sediment toxicity test organisms has become important, especially since sediment/porewater ammonia occurs at higher concentrations than in the water column. Unfortunately, there has been very little of this type information, especially for marine/estuarine organisms. This laboratory determined the toxicity of ammonia to three key marine/estuarine test organisms: the amphipod Eohaustorius estuarius, the bivalve Mytilus edulis, and the echinoderm Strongylocentrotus purpuratus. Because sediment/porewater pH can differ substantially from typical seawater pH, the toxicity evaluations covered a range of pH levels (6, 7, 8, and 9). Eohaustorius results indicate that while Total Ammonia increased in toxicity (measured as EC50) as pH increased (from 460 mg/L at pH 6, to 13 mg/L at pH 9), unionized ammonia toxicity decreased from 0.13 mg/L at pH 6 to 2.8 mg/L at pH 9. The amphipod was much less sensitive to ammonia than were the bivalve and echinoderm, with an unionized ammonia EC50 at pH 8 of 2.14 mg/L relative to 0.43 mg/L for the mussel and 0.13 mg/L for the purple urchin. These results are discussed with respect to design and interpretation of sediment toxicity test results, including an interpretation approach based on partitioning of Toxic Units (TU).

  18. Ammonia Clouds on Jupiter

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [figure removed for brevity, see original site] Click on the image for movie of Ammonia Ice Clouds on Jupiter

    In this movie, put together from false-color images taken by the New Horizons Ralph instrument as the spacecraft flew past Jupiter in early 2007, show ammonia clouds (appearing as bright blue areas) as they form and disperse over five successive Jupiter 'days.' Scientists noted how the larger cloud travels along with a small, local deep hole.

  19. Titan's Ammonia Feature

    NASA Technical Reports Server (NTRS)

    Smythe, W.; Nelson, R.; Boryta, M.; Choukroun, M.

    2011-01-01

    NH3 has long been considered an important component in the formation and evolution of the outer planet satellites. NH3 is particularly important for Titan, since it may serve as the reservoir for atmospheric nitrogen. A brightening seen on Titan starting in 2004 may arise from a transient low-lying fog or surface coating of ammonia. The spectral shape suggests the ammonia is anhydrous, a molecule that hydrates quickly in the presence of water.

  20. Continuum percolation in macromolecular fluids

    NASA Astrophysics Data System (ADS)

    Chatterjee, Avik P.

    2000-11-01

    A heuristic treatment of the connectedness Ornstein-Zernike equation is developed for macromolecular fluids within the framework of the polymer reference interaction site model (PRISM). Results are presented for the critical volume fraction at the percolation threshold and for the mean number of interchain contacts per molecule for athermal rodlike and Gaussian coil-like particles. The results for rodlike particles are in qualitative agreement with prior investigations based on fully numerical solutions of the PRISM equations, and with computer simulations of ellipsoids. The method proposed here leads to the physically reasonable result that the percolation threshold for direct connectivity on the length scale of the molecular dimensions is closely related to the semidilute crossover concentration as usually defined, and can be generalized directly to multicomponent systems.

  1. Asymmetrically Coupled Directed Percolation Systems

    NASA Astrophysics Data System (ADS)

    Noh, Jae Dong; Park, Hyunggyu

    2005-04-01

    We introduce a dynamical model of coupled directed percolation systems with two particle species. The two species A and B are coupled asymmetrically in that A particles branch B particles, whereas B particles prey on A particles. This model may describe epidemic spreading controlled by reactive immunization agents. We study nonequilibrium phase transitions with attention focused on the multicritical point where both species undergo the absorbing phase transition simultaneously. In one dimension, we find that the inhibitory coupling from B to A is irrelevant and the model belongs to the unidirectionally coupled directed percolation class. On the contrary, a mean-field analysis predicts that the inhibitory coupling is relevant and a new universality appears with a variable dynamic exponent. Numerical simulations on small-world networks confirm our predictions.

  2. Percolation in implanted Si film

    NASA Astrophysics Data System (ADS)

    Hiraiwa, Atsushi; Kobayashi, Takashi

    1991-07-01

    The conductivity degradation of implanted Si film has been characterized by nuclear-deposited energy independently of implant conditions. The conductivity decreases as a result of the carrier density change for the nuclear-deposited energy En ? 1 × 1023 eV/cm3, and becomes zero with mobility for En = 2.5 × 1024 eV/cm3. These results have been investigated by the percolation theory with the assistance of the Kinchin-Pease theory. The decrease in carrier density is a result of carrier trapping by vacancy-related defects. The mobility becomes zero when the nondamaged Si cluster is localized by a heavy implantation. The calculation using the site percolation is in good agreement with the experiments, where 0.428 is assumed as the percolation threshold, and 2 as the conductivity exponent. The Si displacement energy obtained is 25 eV by comparing the theory with the experiments. The experimental results suggest that microscopically conductive domains exist even in films that are macroscopically insulating.

  3. Roots at the percolation threshold.

    PubMed

    Kroener, Eva; Ahmed, Mutez Ali; Carminati, Andrea

    2015-04-01

    The rhizosphere is the layer of soil around the roots where complex and dynamic interactions between plants and soil affect the capacity of plants to take up water. The physical properties of the rhizosphere are affected by mucilage, a gel exuded by roots. Mucilage can absorb large volumes of water, but it becomes hydrophobic after drying. We use a percolation model to describe the rewetting of dry rhizosphere. We find that at a critical mucilage concentration the rhizosphere becomes impermeable. The critical mucilage concentration depends on the radius of the soil particle size. Capillary rise experiments with neutron radiography prove that for concentrations below the critical mucilage concentration water could easily cross the rhizosphere, while above the critical concentration water could no longer percolate through it. Our studies, together with former observations of water dynamics in the rhizosphere, suggest that the rhizosphere is near the percolation threshold, where small variations in mucilage concentration sensitively alter the soil hydraulic conductivity. Is mucilage exudation a plant mechanism to efficiently control the rhizosphere conductivity and the access to water? PMID:25974526

  4. "Explosive Percolation" Transition is Actually Continuous

    E-print Network

    R. A. da Costa; S. N. Dorogovtsev; A. V. Goltsev; J. F. F. Mendes

    2010-09-15

    The basic notion of percolation in physics assumes the emergence of a giant connected (percolation) cluster in a large disordered system when the density of connections exceeds some critical value. Until recently, the percolation phase transitions were believed to be continuous, however, in 2009, a remarkably different, discontinuous phase transition was reported in a new so-called "explosive percolation" problem. Each link in this problem is established by a specific optimization process. Here, employing strict analytical arguments and numerical calculations, we find that in fact the "explosive percolation" transition is continuous though with an uniquely small critical exponent of the percolation cluster size. These transitions provide a new class of critical phenomena in irreversible systems and processes.

  5. Optimal percolation of disordered segregated composites.

    PubMed

    Johner, Niklaus; Grimaldi, Claudio; Maeder, Thomas; Ryser, Peter

    2009-02-01

    We evaluate the percolation threshold values for a realistic model of continuum segregated systems, where random spherical inclusions forbid the percolating objects, modeled by hardcore spherical particles surrounded by penetrable shells, to occupy large regions inside the composite. We find that the percolation threshold is generally a nonmonotonous function of segregation, and that an optimal (i.e., minimum) critical concentration exists well before maximum segregation is reached. We interpret this feature as originating from a competition between reduced available volume effects and enhanced concentrations needed to ensure percolation in the highly segregated regime. The relevance with existing segregated materials is discussed. PMID:19391696

  6. Optimal percolation of disordered segregated composites

    NASA Astrophysics Data System (ADS)

    Johner, Niklaus; Grimaldi, Claudio; Maeder, Thomas; Ryser, Peter

    2009-02-01

    We evaluate the percolation threshold values for a realistic model of continuum segregated systems, where random spherical inclusions forbid the percolating objects, modeled by hardcore spherical particles surrounded by penetrable shells, to occupy large regions inside the composite. We find that the percolation threshold is generally a nonmonotonous function of segregation, and that an optimal (i.e., minimum) critical concentration exists well before maximum segregation is reached. We interpret this feature as originating from a competition between reduced available volume effects and enhanced concentrations needed to ensure percolation in the highly segregated regime. The relevance with existing segregated materials is discussed.

  7. WASTE DESCRIPTION RECYCLED OR

    E-print Network

    WASTE DESCRIPTION REDUCED, REUSED, RECYCLED OR CONSERVED POUNDS REDUCED, REUSED, RECYCLED OR CONSERVED IN 2000 WASTE TYPE POTENTIAL COSTS FOR TREATMENT & DISPOSAL COST OF RECYCLE, PREVENTION ESTIMATED and recycled approximately 1.6 liters of mercury rather than disposing of the mercury as hazardous waste

  8. Preventing Theft of Anhydrous Ammonia 

    E-print Network

    Smith, David

    2004-09-16

    Anhydrous ammonia is widely used as a fertilizer. The theft of anhydrous ammonia for use in producing illegal drugs is a growing problem. This publication describes how thieves operate and how farmers and agricultural dealers can protect themselves...

  9. Liberation of ammonia by cyanobacteria

    SciTech Connect

    Newton, J.W.

    1986-04-01

    Photoheterotrophic nitrogen-fixing cyanobacteria release ammonia when treated with methionine sulfoximine (MSX) to inhibit nitrogen incorporation into protein. This released ammonia can be derived from recently fixed nitrogen (nitrogen atmosphere) or endogenous reserves (argon atmosphere). Anaerobic ammonia release requires light and is stimulated by the photosystem II herbicides DCMU and Atrazine, regardless of the source of ammonia. As much as one quarter of the total cellular nitrogen can be released as ammonia by cyanbacteria treated with MSX and DCMU under argon in light. Chromatography of cell extracts indicates that virtually all cellular proteins are degraded. DCMU and Atrazine, at very low concentration, inhibit sustained uptake of the ammonia analog /sup 14/C methylamine. These data indicate that the herbicides interrupt ammonia uptake and retention by the cells, and support a role for photosystem II in ammonia metabolism.

  10. The Chemistry of Liquid Ammonia.

    ERIC Educational Resources Information Center

    Lagowski, J. J.

    1978-01-01

    The solvent and chemical properties of liquid ammonia are presented. In a certain sense, ammonia is a more versatile solvent than is water because of its ability to solubilize, without reaction, highly negative or reducing species. (Author/BB)

  11. The Ammonia-Soda Process.

    ERIC Educational Resources Information Center

    Tingle, M.

    1979-01-01

    This article is a condensed version of a commentary written to accompany a set of slides which describes the ammonia-soda process used by the ammonia-soda plant at Northwich of the United Kingdom. (HM)

  12. 5, 25052540, 2008 Modeling ammonia

    E-print Network

    Paris-Sud XI, Université de

    BGD 5, 2505­2540, 2008 Modeling ammonia interactions with measured leaf wetness in grassland J of atmospheric ammonia and other trace gases with measured leaf surface wetness in a managed grassland canopy J, 2505­2540, 2008 Modeling ammonia interactions with measured leaf wetness in grassland J. Burkhardt et

  13. Polaron Percolation in Diluted Magnetic Semiconductors

    Microsoft Academic Search

    A. Kaminski; S. Das Sarma

    2002-01-01

    We theoretically study the development of spontaneous magnetization in diluted magnetic semiconductors as arising from a percolation of bound magnetic polarons. Within the framework of a generalized percolation theory we derive analytic expressions for the Curie temperature and the magnetization in the limit of low carrier density, obtaining excellent quantitative agreement with Monte Carlo simulation results and good qualitative agreement

  14. Free percolation and seepage flows from watercourses

    Microsoft Academic Search

    K. N. Anakhaev

    2004-01-01

    Free percolation and seepage flows from natural and artificial watercourses with curvilinear profiles are considered. The rigorous hydrodynamic solution of the problem of free percolation and seepage flow from a watercourse is obtained by representing the watercourse profiles in the plane of the Joukowski variable by means of the equation of a family of lemniscates and using the conformal mapping

  15. Crossover from Isotropic to Directed Percolation

    NASA Astrophysics Data System (ADS)

    Fröjdh, Per; den Nijs, Marcel

    1997-03-01

    Directed percolation is one of the generic dynamic universality classes. We study the crossover from isotropic to directed percolation by representing the combined problem as a random cluster model. A parameter r controls the spontaneous birth of new forest fires. We obtain the exact crossover exponent yDP = yT-1 at r = 1 using Coulomb gas methods. Isotropic percolation is stable in 2D. Our numerical finite-size scaling results confirm this. An intuitive argument suggests that directed percolation at r = 0 does not change stability for D>=3. It remains unstable, such that forest fires at 0percolation all dimensions.

  16. Ammonia Anabolism in Ruminants

    Microsoft Academic Search

    Sadao Hoshino; Katsuharu Sarumaru; Kazuwo Morimoto

    1966-01-01

    Ruminal concentrations of ammonia, alpha-ketoglutaric acid, glntamic acid, and glutamine were determined in two feeding periods (alfalfa pellet only and alfalfa pellet + urea) by using fistulated Cor- riedal sheep. By addition of urea, the am- monia concentration exhibited significant increases. Glutamic acid decreased in con- trast to glutamine in concentration, but the differences between the rations were not significant.

  17. Fusion algebra of critical percolation

    E-print Network

    Jorgen Rasmussen; Paul A. Pearce

    2007-08-08

    We present an explicit conjecture for the chiral fusion algebra of critical percolation considering Virasoro representations with no enlarged or extended symmetry algebra. The representations we take to generate fusion are countably infinite in number. The ensuing fusion rules are quasi-rational in the sense that the fusion of a finite number of these representations decomposes into a finite direct sum of these representations. The fusion rules are commutative, associative and exhibit an sl(2) structure. They involve representations which we call Kac representations of which some are reducible yet indecomposable representations of rank 1. In particular, the identity of the fusion algebra is a reducible yet indecomposable Kac representation of rank 1. We make detailed comparisons of our fusion rules with the recent results of Eberle-Flohr and Read-Saleur. Notably, in agreement with Eberle-Flohr, we find the appearance of indecomposable representations of rank 3. Our fusion rules are supported by extensive numerical studies of an integrable lattice model of critical percolation. Details of our lattice findings and numerical results will be presented elsewhere.

  18. Rigidity percolation on aperiodic lattices

    E-print Network

    A. Losev; F. Babalievski

    1997-10-14

    We studied the rigidity percolation (RP) model for aperiodic (quasi-crystal) lattices. The RP thresholds (for bond dilution) were obtained for several aperiodic lattices via computer simulation using the "pebble game" algorithm. It was found that the (two rhombi) Penrose lattice is always floppy in view of the RP model. The same was found for the Ammann's octagonal tiling and the Socolar's dodecagonal tiling. In order to impose the percolation transition we used so c. "ferro" modification of these aperiodic tilings. We studied as well the "pinwheel" tiling which has "infinitely-fold" orientational symmetry. The obtained estimates for the modified Penrose, Ammann and Socolar lattices are respectively: $p_{cP} =0.836\\pm 0.002$, $p_{cA} = 0.769\\pm0.002$, $p_{cS} = 0.938\\pm0.001$. The bond RP threshold of the pinwheel tiling was estimated to $p_c = 0.69\\pm0.01$. It was found that these results are very close to the Maxwell (the mean-field like) approximation for them.

  19. Optical properties of nanocomposites: Percolation films, nanowires, and nanoholes

    Microsoft Academic Search

    Viktor Anatolyevich Podolskiy

    2002-01-01

    The optical properties of percolation films, nanowires, nanowire composites, and nanoholes composites were studied theoretically. Developed theory predicts the existence of localized plasmon modes in metal-dielectric percolation films when the metal concentration is close to the percolation threshold. Due to the plasmon localization local fields, local field fluctuations are extremely enhanced on the surface of percolation composite. This explains enormous

  20. Sharp metastability threshold for an anisotropic bootstrap percolation model

    E-print Network

    for an anisotropic bootstrap percolation model. 1 Introduction 1.1 Statement of the theorem Bootstrap percolationSharp metastability threshold for an anisotropic bootstrap percolation model H. Duminil-Copin, A. C. D. Van Enter October 2010 Abstract Bootstrap percolation models have been extensively studied during

  1. Recovery of ammonia nitrogen in livestock and industrial wastes using gas permeable membranes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    New waste management methods are needed that can protect the environment and allow manure management to switch back to a recycling view of manure handling. We investigated the use of gas-permeable membranes as components of new processes to capture and recover the ammonia in the liquid manures or in...

  2. Connectivity percolation of polydisperse anisotropic nanofillers

    NASA Astrophysics Data System (ADS)

    Otten, Ronald H. J.; van der Schoot, Paul

    2011-03-01

    We present a generalized connectedness percolation theory reduced to a compact form for a large class of anisotropic particle mixtures with variable degrees of connectivity. Even though allowing for an infinite number of components, we derive a compact yet exact expression for the mean cluster size of connected particles. We apply our theory to rodlike particles taken as a model for carbon nanotubes and find that the percolation threshold is sensitive to polydispersity in length, diameter, and the level of connectivity, which may explain large variations in the experimental values for the electrical percolation threshold in carbon-nanotube composites. The calculated connectedness percolation threshold depends only on a few moments of the full distribution function. If the distribution function factorizes, then the percolation threshold is raised by the presence of thicker rods, whereas it is lowered by any length polydispersity relative to the one with the same average length and diameter. We show that for a given average length, a length distribution that is strongly skewed to shorter lengths produces the lowest threshold relative to the equivalent monodisperse one. However, if the lengths and diameters of the particles are linearly correlated, polydispersity raises the percolation threshold and more so for a more skewed distribution toward smaller lengths. The effect of connectivity polydispersity is studied by considering nonadditive mixtures of conductive and insulating particles, and we present tentative predictions for the percolation threshold of graphene sheets modeled as perfectly rigid, disklike particles.

  3. Authorization Recycling in RBAC Systems

    E-print Network

    Authorization Recycling in RBAC Systems 1Laboratory for Education and Research in Secure Systems ·motivation ·recycling approach recycling algorithms experimental evaluations summary & future work #12 issued before (precise recycling) #12;6 Laboratory for Education and Research in Secure Systems

  4. Oceanic emissions of ammonia

    NASA Astrophysics Data System (ADS)

    Paulot, F.; Jacob, D. J.; Johnson, M.; Bell, T. G.; Stock, C. A.; Doney, S. C.

    2013-12-01

    Half of natural ammonia (NH3) emissions is thought to originate from the oceans. Such large emissions have implications for the global budget of N and the acidity of marine aerosols. We develop two new inventories of oceanic NH3 emissions based on simulated monthly NH3 seawater concentrations from the GFDL-COBALT and the CESM-BEC ocean models. These new inventories explicitly account for the effect of temperature on the water-atmosphere exchange of NH3. We evaluate these inventory using cruise observations of gas-phase ammonia (AMT cruises) and ammonium (NOAA cruises) as well as seawater measurement of NHx. Implications of atmospheric NHx observations for the exchange of N between ocean and land and ocean N/P limitations are discussed.

  5. Recycling overview in Sweden

    SciTech Connect

    Not Available

    1989-07-01

    This article discusses the recycling programs currently in use in Sweden. Recycling of newspapers, batteries, plastics are all mentioned in this report by the Swedish Association of Public Cleansing and Solid Waste Management.

  6. Federal Recycling Program Printed on recycled paper.

    E-print Network

    Hoddle, Mark S.

    #12;Federal Recycling Program Printed on recycled paper. The Forest Health Technology Enterprise hibiscus mealybug. Photo by Jeffrey W. Lotz, Florida Department of Agriculture, Conservation Service (www.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis

  7. Roots at the Percolation Threshold

    NASA Astrophysics Data System (ADS)

    Kroener, E.; Ahmed, M. A.; Kaestner, A.; Vontobel, P.; Zarebanadkouki, M.; Carminati, A.

    2014-12-01

    Much of the carbon assimilated by plants during photosynthesis is lost to the soil via rhizodepositions. One component of rhizopdeposition is mucilage, a hydrogel that dramatically alters the soil physical properties. Mucilage was assumed to explain unexpectedly low rhizosphere rewetting rates during irrigation (Carminati et al. 2010) and temporarily water repellency in the rhizosphere after severe drying (Moradi et al. 2012).Here, we present an experimental and theoretical study for the rewetting behaviour of a soil mixed with mucilage, which was used as an analogue of the rhizosphere. Our samples were made of two layers of untreated soils separated by a thin layer (ca. 1 mm) of soil treated with mucilage. We prepared soil columns of varying particle size, mucilage concentration and height of the middle layer above the water table. The dry soil columns were re-wetted by capillary rise from the bottom.The rewetting of the middle layer showed a distinct dual behavior. For mucilage concentrations lower than a certain threshold, water could cross the thin layer almost immediately after rewetting of bulk soil. At slightly higher mucilage concentrations, the thin layer was almost impermeable. The mucilage concentration at the threshold strongly depended on particle size: the smaller the particle size the larger the soil specific surface and the more mucilage was needed to cover the entire particle surface and to induce water repellency.We applied a classic pore network model to simulate the experimental observations. In the model a certain fraction of nodes were randomly disconnected to reproduce the effect of mucilage in temporarily blocking the flow. The percolation model could qualitatively reproduce well the threshold characteristics of the experiments. Our experiments, together with former observations of water dynamics in the rhizosphere, suggest that the rhizosphere is near the percolation threshold, where small variations in mucilage concentration sensitively alter the soil hydraulic conductivity. Is mucilage exudation a plant mechanism to efficiently control the rhizosphere conductivity and the access to water?

  8. Integrated optic ammonia sensor

    NASA Astrophysics Data System (ADS)

    Klein, Rainer; Voges, Edgar I.

    1993-05-01

    Most of the disadvantages that exist with electrochemical devices (e.g., short lifetimes, difficult to miniaturize, need of reference electrodes) can be avoided by using optical sensors. Smock et al. describe a device incorporating a ninhydrin coated fused silica rod that could detect ammonia vapor at concentrations below 100 ppb, however, the reaction is irreversible. Guiliani et al. describe a reversible sensor using a dye coated capillary tube. The dye utilized is oxazine perchlorate, a laser dye. They report that the presence of water vapor is an important factor in the detection of ammonia, and the concentration of water vapor must be controlled. Optical sensors built-up in integrated-optic technique with planar waveguide configurations allow the construction of optical sensor systems for a parallel detection of several chemical species, provide the generation of reference signals, and facilitate the problem of cross-sensitivities. Here, we report on integrated-optic sensors for ammonia detection with a sensitivity in the ppb-range. The reaction is reversible, and the response is independent of the water vapor concentration in the test gas.

  9. Recycling of automotive aluminum

    Microsoft Academic Search

    Jirang CUI; Hans J. ROVEN

    2010-01-01

    With the global warming of concern, the secondary aluminum stream is becoming an even more important component of aluminum production and is attractive because of its economic and environmental benefits. In this work, recycling of automotive aluminum is reviewed to highlight environmental benefits of aluminum recycling, use of aluminum alloys in automotive applications, automotive recycling process, and new technologies in

  10. Recycling and the automobile

    SciTech Connect

    Holt, D.J.

    1993-10-01

    This article examines the current status of automobile recycling and contains a summary of a survey which points out the major drivers and their impacts on automotive recycling. The topics of the article include computerized dismantling, polyurethane, sheet molding compound, polyester, thermoplastic polyester, recycling salvaged parts, vinyl and automotive shredder residue.

  11. Buying recycled helps market

    SciTech Connect

    Watts, G. [City of Thousand Oaks, CA (United States)

    1996-08-01

    The waste reduction and recycling program of Thousand Oaks, California is summarized. Descriptions of the program, market development for recycled products, business development, and economic development are provided. The emphasis of the program is on market development for recycled products. Procurement guidelines used by the city are reprinted in the paper.

  12. The Economics of Recycling.

    ERIC Educational Resources Information Center

    Bogert, Susan; Morris, Jeffrey

    1993-01-01

    Reports the findings of a study that documented 1992 costs of residential curbside recycling versus disposal systems in four Washington State cities: Seattle, Spokane, Bellingham, and Vancouver. Results indicated that recycling can be less expensive than disposal when the revenues obtained from selling recycled materials are considered. (MDH)

  13. Much Ado about Recycling.

    ERIC Educational Resources Information Center

    Elliot, Ian

    1993-01-01

    Discusses a solid waste recycling workshop for students and teachers sponsored by the Southwest Connecticut Regional Operating Committee (SWEROC), a consortium of 19 towns and cities organized to help implement a regional recycling program. The SWEROC workshop utilized games and team activities to teach students about recycling and the…

  14. Noise sensitivity of Boolean functions and percolation

    E-print Network

    Steif, Jeffrey

    Noise sensitivity of Boolean functions and percolation Christophe Garban1 Jeffrey E. Steif2 1 ENS, Kalai, Linial theorem . . . . . . . . . . . . . . . . . . . . . 12 5 Noise sensitivity and noise stability . . . . . . . . . . . . . . . . . . . . 14 6 The Benjamini, Kalai and Schramm noise sensitivity

  15. Percolation of secret correlations in a network

    E-print Network

    Raul, Garcia-Patron

    In this work, we explore the analogy between entanglement and secret classical correlations in the context of large networks—more precisely, the question of percolation of secret correlations in a network. It is known that ...

  16. Inverting the Achlioptas rule for explosive percolation

    E-print Network

    R. A. da Costa; S. N. Dorogovtsev; A. V. Goltsev; J. F. F. Mendes

    2015-04-24

    In the usual Achlioptas processes the smallest clusters of a few randomly chosen ones are selected to merge together at each step. The resulting aggregation process leads to the delayed birth of a giant cluster and the so-called explosive percolation transition showing a set of anomalous features. We explore a process with the opposite selection rule, in which the biggest clusters of the randomly chosen ones merge together. We develop a theory of this kind of percolation based on the Smoluchowski equation, find the percolation threshold, and describe the scaling properties of this continuous transition, namely, the critical exponents and amplitudes, and scaling functions. We show that, qualitatively, this transition is similar to the ordinary percolation one, though occurring in less connected systems.

  17. On how percolation threshold affects PSO performance

    E-print Network

    Cases, Blanca; Moujahid, Abdelmalik

    2012-01-01

    Statistical evidence of the influence of neighborhood topology on the performance of particle swarm optimization (PSO) algorithms has been shown in many works. However, little has been done about the implications could have the percolation threshold in determining the topology of this neighborhood. This work addresses this problem for individuals that, like robots, are able to sense in a limited neighborhood around them. Based on the concept of percolation threshold, and more precisely, the disk percolation model in 2D, we show that better results are obtained for low values of radius, when individuals occasionally ask others their best visited positions, with the consequent decrease of computational complexity. On the other hand, since percolation threshold is a universal measure, it could have a great interest to compare the performance of different hybrid PSO algorithms.

  18. Connectivity percolation in suspensions of hard platelets

    E-print Network

    Maneesh Mathew; Tanja Schilling; Martin Oettel

    2012-04-13

    We present a study on connectivity percolation in suspensions of hard platelets by means of Monte Carlo simulation. We interpret our results using a contact-volume argument based on an effective single--particle cell model. It is commonly assumed that the percolation threshold of anisotropic objects scales as their inverse aspect ratio. While this rule has been shown to hold for rod-like particles, we find that for hard plate-like particles the percolation threshold is non-monotonic in the aspect ratio. It exhibits a shallow minimum at intermediate aspect ratios and then saturates to a constant value. This effect is caused by the isotropic-nematic transition pre-empting the percolation transition. Hence the common strategy to use highly anisotropic, conductive particles as fillers in composite materials in order to produce conduction at low filler concentration is expected to fail for plate-like fillers such as graphene and graphite nanoplatelets.

  19. Continuum Percolation in the Relative Neighborhood Graph

    E-print Network

    Jean-Michel Billiot; Franck Corset; Eric Fontenas

    2010-04-29

    In the present study, we establish the existence of nontrivial site percolation threshold in the Relative Neighborhood Graph (RNG) for Poisson stationary point process with unit intensity in the plane.

  20. QUANTIFIED DETRIMENT OF AMMONIA TO BROILERS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ammonia levels in broiler houses can reduce bird performance, increase susceptibility to disease and increase subsequent mortality. House management, season, humidity, stocking density, and litter properties influence ammonia concentrations. Though it is widely known that ammonia is detrimental to p...

  1. Oriented Percolation in One-Dimensional 1/|x-y|^2 Percolation Models

    E-print Network

    D. H. U. Marchetti; V. Sidoravicius; M. E. Vares

    2013-04-25

    We consider independent edge percolation models on Z, with edge occupation probabilities p_ = p if |x-y| = 1, 1 - exp{- beta / |x-y|^2} otherwise. We prove that oriented percolation occurs when beta > 1 provided p is chosen sufficiently close to 1, answering a question posed in [Commun. Math. Phys. 104, 547 (1986)]. The proof is based on multi-scale analysis.

  2. A Percolation Model for Fracking

    NASA Astrophysics Data System (ADS)

    Norris, J. Q.; Turcotte, D. L.; Rundle, J. B.

    2014-12-01

    Developments in fracking technology have enabled the recovery of vast reserves of oil and gas; yet, there is very little publicly available scientific research on fracking. Traditional reservoir simulator models for fracking are computationally expensive, and require many hours on a supercomputer to simulate a single fracking treatment. We have developed a computationally inexpensive percolation model for fracking that can be used to understand the processes and risks associated with fracking. In our model, a fluid is injected from a single site and a network of fractures grows from the single site. The fracture network grows in bursts, the failure of a relatively strong bond followed by the failure of a series of relatively weak bonds. These bursts display similarities to micro seismic events observed during a fracking treatment. The bursts follow a power-law (Gutenburg-Richter) frequency-size distribution and have growth rates similar to observed earthquake moment rates. These are quantifiable features that can be compared to observed microseismicity to help understand the relationship between observed microseismicity and the underlying fracture network.

  3. Connectedness percolation in monodisperse rod systems: clustering effects

    NASA Astrophysics Data System (ADS)

    Chatterjee, Avik P.

    2011-09-01

    A model is presented that examines the impact of local clustering upon the percolation behaviour of interpenetrable rod-like particles. The percolation threshold, as well as percolation and backbone probabilities, are evaluated as functions of the particle aspect ratio and degree of clustering by way of an analogy to a lattice site percolation problem. The formation of local, physically connected cliques of particles is shown to raise the percolation threshold whilst reducing the percolation and backbone fractions for a fixed volume fraction of particles.

  4. Modeling of heat generation in ammonia-treated solid rocket propellant

    SciTech Connect

    Raun, R.L.; Isom, K.B. [Hercules, Inc., Magna, UT (United States)] [Hercules, Inc., Magna, UT (United States)

    1995-06-01

    With the end of the Cold War, safe, environmentally sound separation, recycling, and disposal of ingredients in solid rocket propellants and munitions has become a national priority. One approach to demilitarize solid rocket propellants is treatment with ammonia. Ammonia extracts the oxidizers ammonium perchlorate and HMX, yielding a solid reside that is more suitable for incineration and less sensitive to impact and other modes of accidental initiation. Ammonia treatment of nitroglycerin-containing propellants is complicated by an exothermic reaction between ammonia and nitroglycerin. If not removed, the heat generated by this reaction can cause propellant ignition. To help design safe treatment processes, a model for the ammonia-propellant reaction was developed, which integrates transient energy and species conservation equations to simulate ammonia diffusion, heat generation, and heat flow in a propellant and in the solid residue resulting from ammonia treatment. It was calibrated using residue thickness and thermocouple data for one propellant. The calibrated model was used to predict conditions leading to ignition of thin propellant strips. The results agree well with experimental observations.

  5. Analysis of a municipal recyclable material recycling program

    Microsoft Academic Search

    Pei-Hai Yu; Horng-Guang Leu; Sheng H. Lin

    1996-01-01

    The recyclable material recycling program organized and operated by a small town in northern Taiwan is investigated. Emphasis of the present study is placed on the operation, analysis of the annual amounts of recyclable material collection and on the operational cost-benefit analysis of the recycling program. Examination of the operational data reveals that the recycling program is in good financial

  6. St Andrews Recycling Points Recycling Points are situated locally to

    E-print Network

    St Andrews, University of

    St Andrews Recycling Points Recycling Points are situated locally to allow you to recycle the following materials: To find your nearest Recycling Point please visit www.fifedirect.org.uk/wasteaware or call the Recycling Helpline on 08451 55 00 22. R&A GOLF CLUB OLD COURSE HOTEL UNIVERSITY NORTH HAUGH

  7. Renal Ammonia Metabolism and Transport

    PubMed Central

    Weiner, I. David; Verlander, Jill W.

    2015-01-01

    Renal ammonia metabolism and transport mediates a central role in acid-base homeostasis. In contrast to most renal solutes, the majority of renal ammonia excretion derives from intrarenal production, not from glomerular filtration. Renal ammoniagenesis predominantly results from glutamine metabolism, which produces 2 NH4+ and 2 HCO3? for each glutamine metabolized. The proximal tubule is the primary site for ammoniagenesis, but there is evidence for ammoniagenesis by most renal epithelial cells. Ammonia produced in the kidney is either excreted into the urine or returned to the systemic circulation through the renal veins. Ammonia excreted in the urine promotes acid excretion; ammonia returned to the systemic circulation is metabolized in the liver in a HCO3?-consuming process, resulting in no net benefit to acid-base homeostasis. Highly regulated ammonia transport by renal epithelial cells determines the proportion of ammonia excreted in the urine versus returned to the systemic circulation. The traditional paradigm of ammonia transport involving passive NH3 diffusion, protonation in the lumen and NH4+ trapping due to an inability to cross plasma membranes is being replaced by the recognition of limited plasma membrane NH3 permeability in combination with the presence of specific NH3-transporting and NH4+-transporting proteins in specific renal epithelial cells. Ammonia production and transport are regulated by a variety of factors, including extracellular pH and K+, and by several hormones, such as mineralocorticoids, glucocorticoids and angiotensin II. This coordinated process of regulated ammonia production and transport is critical for the effective maintenance of acid-base homeostasis. PMID:23720285

  8. Recycling Service Learning Activity

    NSDL National Science Digital Library

    Renee Faatz

    The recycling project begins with students learning about waste and resources. They complete background assignments about the energy and materials required to manufacture paper, aluminum, etc. They study landfills and the issues related to space, pollution, etc. They look at what is different if these things are recycled. The students work in groups of two or three and adopt and academic building on campus. They educate the staff and faculty about recycling - what can be recycled and where. They arrange to pick-up paper from each office. My hope is that the college faculty, staff and students will eventually recycle paper at common bins and that our project will progress to adding other recyclables to our project.

  9. Percolation on Graphs with Four-Edges

    E-print Network

    Ojan Khatib Damavandi; Robert M. Ziff

    2015-06-19

    We study percolation on self-dual hypergraphs that contain square hyperedges, using two different four-vertex generators, each containing bonds with three distinct probabilities $p$, $r$, and $t$. We find explicit values of these probabilities that satisfy the self-duality conditions discussed by Bollob\\'as and Riordan. We consider these generators on two different hypergraphs, providing new examples of lattices where exact percolation critical points are known. We carry out Monte-Carlo simulations to confirm these values. For the case of the hypergraph and uniform generator studied by Wierman et al., we also determine the threshold $p = 0.441374\\pm 0.000001$, which falls within the tight bounds that they derived. We also study a four-vertex generator which exhibits three distinct criticality solutions ($p$, $r$, $t$). Furthermore, we consider a generator in which all or none of the vertices can connect, and find a soluble inhomogeneous percolation system that interpolates between site percolation on the union-jack lattice and bond percolation on the square lattice.

  10. Growth dominates choice in network percolation

    NASA Astrophysics Data System (ADS)

    Vijayaraghavan, Vikram S.; Noël, Pierre-André; Waagen, Alex; D'Souza, Raissa M.

    2013-09-01

    The onset of large-scale connectivity in a network (i.e., percolation) often has a major impact on the function of the system. Traditionally, graph percolation is analyzed by adding edges to a fixed set of initially isolated nodes. Several years ago, it was shown that adding nodes as well as edges to the graph can yield an infinite order transition, which is much smoother than the traditional second-order transition. More recently, it was shown that adding edges via a competitive process to a fixed set of initially isolated nodes can lead to a delayed, extremely abrupt percolation transition with a significant jump in large but finite systems. Here we analyze a process that combines both node arrival and edge competition. If started from a small collection of seed nodes, we show that the impact of node arrival dominates: although we can significantly delay percolation, the transition is of infinite order. Thus, node arrival can mitigate the trade-off between delay and abruptness that is characteristic of explosive percolation transitions. This realization may inspire new design rules where network growth can temper the effects of delay, creating opportunities for network intervention and control.

  11. Recycling of the continental crust

    Microsoft Academic Search

    Scott M. McLennan

    1988-01-01

    In order to understand the evolution of the crust-mantle system, it is important to recognize the role played by the recycling of continental crust. Crustal recycling can be considered as two fundamentally distinct processes: 1) intracrustal recycling and 2) crust-mantle recycling. Intracrustal recycling is the turnover of crustal material by processes taking place wholly within the crust and includes most

  12. Factors Influencing Household Recycling Behavior

    Microsoft Academic Search

    Stuart Oskamp; Maura J. Harrington; Todd C. Edwards; Deborah L. Sherwood; Shawn M. Okuda; Deborah C. Swanson

    1991-01-01

    To investigate factors encouraging or deterring recycling, telephone interviews were used to study recycling behavior, attitudes, and knowledge of 221 randomly selected adults in a suburban city that had begun a citywide curbside recycling program within the past year. Approximately 40% reported participation in the curbside recycling program, and nearly 20% more claimed that their household had been recycling in

  13. Announcing: All Recycling Reduce your

    E-print Network

    Papautsky, Ian

    Announcing: All Recycling Go Green! Reduce your contribution to the landfill, by choosing to voluntarily recycle acceptable items in the green All Recycling toters and containers around campus. ONLY THE ITEMS BELOW ARE ACCEPTED FOR ALL RECYCLING Please do not contaminate the recycling containers with trash

  14. Combustion Byproducts Recycling Consortium

    SciTech Connect

    Paul Ziemkiewicz; Tamara Vandivort; Debra Pflughoeft-Hassett; Y. Paul Chugh; James Hower

    2008-08-31

    Ashlines: To promote and support the commercially viable and environmentally sound recycling of coal combustion byproducts for productive uses through scientific research, development, and field testing.

  15. Connectedness percolation in fluids of persistent chains

    NASA Astrophysics Data System (ADS)

    Chatterjee, Avik P.

    2002-12-01

    An integral equation approach to understanding connectedness percolation in macromolecular fluids is extended to investigate semiflexible linear homopolymers. A coarse-grained threadlike approximation is developed for persistent chains. Results are presented for the percolation threshold, and number of intermolecular contacts at the threshold, as functions of the polymer stiffness. A substantial reduction of the percolation threshold is observed, and a dependence of this threshold on the contour length similar to that for rigid rodlike particles is found, even for large ratios of the contour to the persistence lengths provided the latter exceeds the range over which neighboring monomers are viewed as belonging to the same physical cluster. Accounting for chain stiffness leads to pair correlation functions which, at small separations, display features akin to those observed in fluids of rodlike particles, resulting in much lower critical volume fractions than for fully flexible molecules.

  16. Conformal invariance in three dimensional percolation

    E-print Network

    Gori, G

    2015-01-01

    The aim of the paper is to present numerical results supporting the presence of conformal invariance in three dimensional statistical mechanics models at criticality and to elucidate the geometric aspects of universality. As a case study we study three dimensional percolation at criticality in bounded domains. Both on discrete and continuous models of critical percolation, we test by numerical experiments the invariance of quantities in finite domains under conformal transformations focusing on crossing probabilities. Our results show clear evidence of the onset of conformal invariance in finite realizations especially for the continuum percolation models. Finally we propose a simple analytical function approximating the crossing probability among two spherical caps on the surface of a sphere and confront it with the numerical results.

  17. Factors influencing breath ammonia determination.

    PubMed

    Solga, Steven F; Mudalel, Matthew; Spacek, Lisa A; Lewicki, Rafal; Tittel, Frank; Loccioni, Claudio; Russo, Adolfo; Risby, Terence H

    2013-09-01

    Amongst volatile compounds (VCs) present in exhaled breath, ammonia has held great promise and yet it has confounded researchers due to its inherent reactivity. Herein we have evaluated various factors in both breath instrumentation and the breath collection process in an effort to reduce variability. We found that the temperature of breath sampler and breath sensor, mouth rinse pH, and mode of breathing to be important factors. The influence of the rinses is heavily dependent upon the pH of the rinse. The basic rinse (pH 8.0) caused a mean increase of the ammonia concentration by 410 ± 221 ppb. The neutral rinse (pH 7.0), slightly acidic rinse (pH 5.8), and acidic rinse (pH 2.5) caused a mean decrease of the ammonia concentration by 498 ± 355 ppb, 527 ± 198 ppb, and 596 ± 385 ppb, respectively. Mode of breathing (mouth-open versus mouth-closed) demonstrated itself to have a large impact on the rate of recovery of breath ammonia after a water rinse. Within 30 min, breath ammonia returned to 98 ± 16% that of the baseline with mouth open breathing, while mouth closed breathing allowed breath ammonia to return to 53 ± 14% of baseline. These results contribute to a growing body of literature that will improve reproducibly in ammonia and other VCs. PMID:23774041

  18. Ammonia Ice Clouds on Jupiter

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The top cloud layer on Jupiter is thought to consist of ammonia ice, but most of that ammonia 'hides' from spectrometers. It does not absorb light in the same way ammonia does. To many scientists, this implies that ammonia churned up from lower layers of the atmosphere 'ages' in some way after it condenses, possibly by being covered with a photochemically generated hydrocarbon mixture. The New Horizons Linear Etalon Imaging Spectral Array (LEISA), the half of the Ralph instrument that is able to 'see' in infrared wavelengths that are absorbed by ammonia ice, spotted these clouds and watched them evolve over five Jupiter days (about 40 Earth hours). In these images, spectroscopically identified fresh ammonia clouds are shown in bright blue. The largest cloud appeared as a localized source on day 1, intensified and broadened on day 2, became more diffuse on days 3 and 4, and disappeared on day 5. The diffusion seemed to follow the movement of a dark spot along the boundary of the oval region. Because the source of this ammonia lies deeper than the cloud, images like these can tell scientists much about the dynamics and heat conduction in Jupiter's lower atmosphere.

  19. Argon recovery from hydrogen depleted ammonia plant purge gas using a HARP Plant

    SciTech Connect

    Krishnamurthy, R.; Lerner, S.L.; Maclean, D.L.

    1987-01-01

    A number of ammonia plants employ membranes or cryogenic hydrogen recovery units to separate hydrogen contained in the purge gas for recycle to the ammonia synthesis loop. The resulting hydrogen depleted purge gas, which is usually used for fuel, is an attractive source of argon. This paper presents the novel features of a process which employs a combination of pressure swing adsorption (PSA) and cryogenic technology to separate the argon from this hydrogen depleted purge gas stream. This new proprietary Hybrid Argon Recovery Progress (HARP) plant is an effective alternative to a conventional all-cryogenic plant.

  20. Ammonia as efficient fuel for SOFC

    Microsoft Academic Search

    A. Fuerte; R. X. Valenzuela; M. J. Escudero; L. Daza

    2009-01-01

    Ammonia is a possible candidate as the fuel for SOFCs. In this work, the influence on the performance of a tubular SOFC running on ammonia is studied. Analysis of open circuit voltages (OCVs) on the cell indicated the oxidation of ammonia within a SOFC is a two-stage process: decomposition of the inlet ammonia into nitrogen and hydrogen, followed by oxidation

  1. ENGINEERING DESIGN CONFIGURATIONS FOR BIOLOGICAL AMMONIA REMOVAL

    EPA Science Inventory

    Many regions in the United States have excessive levels of nutrients including ammonia in their source waters. For example, farming and agricultural sources of ammonia in the Midwest contribute to relatively high levels of ammonia in many ground waters. Although ammonia in water ...

  2. Ammonia distribution and excretion in fish

    Microsoft Academic Search

    David J. Randall; Patricia A. Wright

    1987-01-01

    This paper reviews the literature concerning ammonia production, storage and excretion in fish. Ammonia is the end product of protein catabolism and is stored in the body of fish in high concentrations relative to basal excretion rates. Ammonia, if allowed to accumulate, is toxic and is converted to less toxic compounds or excreted. Like other weak acids and bases, ammonia

  3. Breath Ammonia Analysis: Clinical Application and Measurement

    Microsoft Academic Search

    Troy Hibbard; Anthony J. Killard

    2011-01-01

    This review covers in detail the complexity of human breath, how the body metabolizes ammonia, clinical conditions which are directly related to the regulation of ammonia concentration, and analysis of current techniques that are capable of detecting breath ammonia. Focusing on these areas provides the information needed to develop a breath ammonia sensor for monitoring dysfunction of the human body.

  4. Feedstock recycling of polymer wastes

    Microsoft Academic Search

    Arthur A. Garforth; Salmiaton Ali; Jesús Hernández-Martínez; Aaron Akah

    2004-01-01

    Current common polymer waste recycling methods, mechanical recycling and energy recovery, have drawbacks such as labour intensive sorting and atmospheric pollution. Feedstock recycling has emerged as an environmentally successful alternative for polymer waste management.

  5. Bootstrap percolation on homogeneous trees has 2 phase transitions

    E-print Network

    Schonmann, Roberto H.

    the right at pc and, only in the case = b, also from the left at pf . 1 Introduction Bootstrap percolationBootstrap percolation on homogeneous trees has 2 phase transitions L.R.G. Fontes R.H. Schonmann Abstract We study the threshold bootstrap percolation model on the homoge- neous tree with degree b + 1, 2

  6. Lattice trees, percolation and super-Brownian motion

    E-print Network

    Slade, Gordon

    Lattice trees, percolation and super-Brownian motion Gordon Slade April 2, 1999 Abstract This paper and the incipient infinite percolation cluster, in high dimen- sions. A potential extension to oriented percolation (ISE), a close relative of super-Brownian motion (SBM). SBM is a funda- mental example of a measure

  7. Percolating states in the topological Anderson insulator

    NASA Astrophysics Data System (ADS)

    Girschik, Adrian; Libisch, Florian; Rotter, Stefan

    2015-06-01

    We investigate the presence of percolating states in disordered two-dimensional topological insulators. In particular, we uncover a close connection between these states and the so-called topological Anderson insulator, which is a topologically nontrivial phase induced by the presence of disorder. The decay of this phase could previously be connected to a delocalization of bulk states with increasing disorder strength. We identify this delocalization to be the result of a percolation transition of states that circumnavigate the hills of the bulk disorder potential.

  8. AQUEOUS AMMONIA EQUILIBRIUM - TABULATION OF PERCENT UN-IONIZED AMMONIA

    EPA Science Inventory

    The percent of un-ionized ammonia as a function of pH and temperature in aqueous ammonia solutions of zero salinity is presented in tabular form over the following ranges: temperature 0.0 to 40.0 C in increments of 0.2 degree, and pH 5.00 to 12.00 in increments of 0.01 pH unit....

  9. Ammonia-mediated, large-scale synthesis of ammonia borane.

    PubMed

    Ramachandran, P Veeraraghavan; Mistry, Hitesh; Kulkarni, Ameya S; Gagare, Pravin D

    2014-11-28

    A simple, large-scale synthesis of ammonia borane from NaBH4 and (NH4)2SO4 at 0 °C-rt in THF containing 5% NH3 is described. The presence of ammonia is critical for the reaction to proceed and allows the reaction at high concentrations and ambient temperature without the need for anhydrous solvent or inert atmosphere. PMID:25274135

  10. Waste hydrocarbons recycling

    Microsoft Academic Search

    Brinkman

    1986-01-01

    During the 1970s, the U.S. supply of petroleum was predicted to be quickly vanishing. The price we would have to pay for what remained would be unprecedented. All alternatives would not only have to be explored, but exploited to their fullest potential. In that decade of recycling aluminum cans, glass bottles, and newspapers by the truckloads, the recycling of petroleum

  11. Wee Recyclers Resources.

    ERIC Educational Resources Information Center

    Wisconsin State Dept. of Natural Resources, Madison.

    Hands-on activities in this guide are designed to help preschool children (ages 3-5) understand that reducing, reusing, and recycling preserves natural resources and prolongs the life of landfills. Children sort, match and compare recyclable items and learn to separate some items by number and color. The 29 activities are divided into units that…

  12. Recycling and Composting

    NSDL National Science Digital Library

    2005-01-01

    In this lesson, students learn about the value of renewable resources. Using multimedia intractives, video, and classroom activities, they learn to identify examples of renewable resources and how humans use them, understand what recycling and conservation are, learn about composting, and identify food waste and household items that can be recycled or composted.

  13. Recycling into Art

    NSDL National Science Digital Library

    Debra Fioranelli

    2000-10-01

    This interdisciplinary unit weaves art and science together to help students appreciate the importance of recycling. In this engaging activity, students collected items worthy of recycling from home, and with the help of the art teacher, used a loom to cr

  14. Partnership: Recycling $/$ Outdoor Education.

    ERIC Educational Resources Information Center

    Weir, Phil

    1996-01-01

    The Ottawa Board of Education (Ontario, Canada) has committed revenues generated by a districtwide recycling program to help fund the MacSkimming Outdoor Education Centre. A partnership between recycling and outdoor education is valuable in developing an environmental ethic among students and in finding new ways to fund outdoor education. (LP)

  15. Carbon dioxide recycling

    EPA Science Inventory

    The recycling of carbon dioxide to methanol and dimethyl ether is seen to offer a substantial route to renewable and environmentally carbon neutral fuels. One of the authors has championed the ?Methanol Economy" in articles and a book. By recycling ambient CO2, the authors argue ...

  16. The Fermilab recycler ring

    SciTech Connect

    Martin Hu

    2001-07-24

    The Fermilab Recycler is a permanent magnet storage ring for the accumulation of antiprotons from the Antiproton Source, and the recovery and cooling of the antiprotons remaining at the end of a Tevatron store. It is an integral part of the Fermilab III luminosity upgrade. The following paper describes the design features, operational and commissioning status of the Recycler Ring.

  17. Fuel cell recycling system

    Microsoft Academic Search

    Sederquist

    1988-01-01

    This patent describes a fuel cell recycling system comprising: first fuel cells being adapted to electrochemically convert fuel into electricity and exhaust; second fuel cells being adapted to electrochemically convert fuel into electricity and exhaust; feed means for supplying fuel to the first fuel cells in parallel; exhaust means for receiving exhaust from the first fuel cells; recycling means for

  18. Percolation on Graphs with Four-Edges

    E-print Network

    Damavandi, Ojan Khatib

    2015-01-01

    We study percolation on self-dual hypergraphs that contain square hyperedges, using two different four-vertex generators, each containing bonds with three distinct probabilities $p$, $r$, and $t$. We find explicit values of these probabilities that satisfy the self-duality conditions discussed by Bollob\\'as and Riordan. We consider these generators on two different hypergraphs, providing new examples of lattices where exact percolation critical points are known. We carry out Monte-Carlo simulations to confirm these values. For the case of the hypergraph and uniform generator studied by Wierman et al., we also determine the threshold $p = 0.441374\\pm 0.000001$, which falls within the tight bounds that they derived. We also study a four-vertex generator which exhibits three distinct criticality solutions ($p$, $r$, $t$). Furthermore, we consider a generator in which all or none of the vertices can connect, and find a soluble inhomogeneous percolation system that interpolates between site percolation on the unio...

  19. Percolation on general trees and HIV modeling

    NASA Astrophysics Data System (ADS)

    Ahmed, E.; Agiza, H. N.

    1996-12-01

    Percolation on a general tree is studied. A general tree is used to model the transition from HIV infection into AIDS and to explain the large differences of the transition time from one patient to another. HIV has some autoimmune effects due to its low antigenic mutants. Fuzzy mathematics is used to explain these effects.

  20. Crossover from isotropic to directed percolation

    NASA Astrophysics Data System (ADS)

    Zhou, Zongzheng; Yang, Ji; Ziff, Robert M.; Deng, Youjin

    2012-08-01

    We generalize the directed percolation (DP) model by relaxing the strict directionality of DP such that propagation can occur in either direction but with anisotropic probabilities. We denote the probabilities as p?=ppd and p?=p(1-pd), with p representing the average occupation probability and pd controlling the anisotropy. The Leath-Alexandrowicz method is used to grow a cluster from an active seed site. We call this model with two main growth directions biased directed percolation (BDP). Standard isotropic percolation (IP) and DP are the two limiting cases of the BDP model, corresponding to pd=1/2 and pd=0,1 respectively. In this work, besides IP and DP, we also consider the 1/2percolation thresholds of the BDP model for pd=0.6 and 0.8, and determine various critical exponents. These exponents are found to be consistent with those for standard DP. We also determine the renormalization exponent associated with the asymmetric perturbation due to pd-1/2?0 near IP, and confirm that such an asymmetric scaling field is relevant at IP.

  1. Connectivity of Mandelbrot's Percolation Process Sunjay Cauligi

    E-print Network

    Morrow, James A.

    Percolation . . . . . . . . . . . . . . . . . . . . . . . 3 3 Analysis of Connectivity 5 3.1 Proof of Theorem, and if the plane is tiled with independently generated copies of the set, then there exists a critical probability taking place. Unfortunately, a discourse on probability measure is outside the scope of this paper, so we

  2. 75 FR 71003 - America Recycles Day, 2010

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-19

    ...our planet, participating in curbside recycling and community composting programs, and...of recyclable and recycled materials. Recycling not only preserves our environment by...workers nationwide, and evolving our recycling practices can help create green...

  3. Intracage Ammonia Levels in Static and Individually Ventilated Cages Housing C57BL/6 Mice on 4 Bedding Substrates

    PubMed Central

    Ferrecchia, Christie E; Jensen, Kelly; Andel, Roger Van

    2014-01-01

    The relationship among ammonia levels, cage-changing frequency, and bedding types is an important and potentially controversial topic in the laboratory animal science community. Some bedding options may not provide sufficient urine absorption and bacterial regulation to minimize ammonia production during the interval between cage changes. High intracage ammonia levels can cause subclinical degeneration and inflammation of nasal passages, rhinitis and olfactory epithelial necrosis in exposed mice. Here we sought to compare the effects of 4 commonly used bedding substrates (1/4-in. irradiated corncob, reclaimed wood pulp, aspen wood chips, and recycled newspaper) on ammonia generation when housing female C57BL/6 mice in static and individually ventilated caging. Intracage ammonia levels were measured daily for 1 wk (static cage experiment) or 2 wk (IVC experiment). The results of this study suggest that the corncob, aspen wood chip, and recycled newspaper beddings that we tested are suitable for once-weekly cage changing for static cages and for changing every 2 wk for IVC. However, ammonia levels were not controlled appropriately in cages containing reclaimed wood pulp bedding, and pathologic changes occurred within 1 wk in the nares of mice housed on this bedding in static cages. PMID:24602540

  4. Intracage ammonia levels in static and individually ventilated cages housing C57BL/6 mice on 4 bedding substrates.

    PubMed

    Ferrecchia, Christie E; Jensen, Kelly; Van Andel, Roger

    2014-03-01

    The relationship among ammonia levels, cage-changing frequency, and bedding types is an important and potentially controversial topic in the laboratory animal science community. Some bedding options may not provide sufficient urine absorption and bacterial regulation to minimize ammonia production during the interval between cage changes. High intracage ammonia levels can cause subclinical degeneration and inflammation of nasal passages, rhinitis and olfactory epithelial necrosis in exposed mice. Here we sought to compare the effects of 4 commonly used bedding substrates (1/4-in. irradiated corncob, reclaimed wood pulp, aspen wood chips, and recycled newspaper) on ammonia generation when housing female C57BL/6 mice in static and individually ventilated caging. Intracage ammonia levels were measured daily for 1 wk (static cage experiment) or 2 wk (IVC experiment). The results of this study suggest that the corncob, aspen wood chip, and recycled newspaper beddings that we tested are suitable for once-weekly cage changing for static cages and for changing every 2 wk for IVC. However, ammonia levels were not controlled appropriately in cages containing reclaimed wood pulp bedding, and pathologic changes occurred within 1 wk in the nares of mice housed on this bedding in static cages. PMID:24602540

  5. Reversible first-order transition in Pauli percolation

    NASA Astrophysics Data System (ADS)

    Maksymenko, Mykola; Moessner, Roderich; Shtengel, Kirill

    2015-06-01

    Percolation plays an important role in fields and phenomena as diverse as the study of social networks, the dynamics of epidemics, the robustness of electricity grids, conduction in disordered media, and geometric properties in statistical physics. We analyze a new percolation problem in which the first-order nature of an equilibrium percolation transition can be established analytically and verified numerically. The rules for this site percolation model are physical and very simple, requiring only the introduction of a weight W (n )=n +1 for a cluster of size n . This establishes that a discontinuous percolation transition can occur with qualitatively more local interactions than in all currently considered examples of explosive percolation; and that, unlike these, it can be reversible. This greatly extends both the applicability of such percolation models in principle and their reach in practice.

  6. On the relationship between rheology and percolation in the gelation of weakly attractive colloids: Beyond "snapshot" percolation

    E-print Network

    Luis A. Pugnaloni

    2004-06-29

    A discussion on the viscoelastic properties of weakly attractive colloids and the relation to a newly developed percolation theory is presented. The need for taking into account the particle-particle bond lifetime in order to compare rheological and percolation estimates of the sol-gel transition is stressed. Recent molecular dynamics simulations and generalised percolation theory that use a bond lifetime criterion in the definition of aggregates show that the percolation transition can be reconciled with the rheological sol-gel transition. The percolation concept is used here as a "measuring" tool to assess the viscoelastic behaviour of the system.

  7. Solvent recycle/recovery

    SciTech Connect

    Paffhausen, M.W.; Smith, D.L.; Ugaki, S.N.

    1990-09-01

    This report describes Phase I of the Solvent Recycle/Recovery Task of the DOE Chlorinated Solvent Substitution Program for the US Air Force by the Idaho National Engineering Laboratory, EG G Idaho, Inc., through the US Department of Energy, Idaho Operations Office. The purpose of the task is to identify and test recovery and recycling technologies for proposed substitution solvents identified by the Biodegradable Solvent Substitution Program and the Alternative Solvents/Technologies for Paint Stripping Program with the overall objective of minimizing hazardous wastes. A literature search to identify recycle/recovery technologies and initial distillation studies has been conducted. 4 refs.

  8. RETHINKING WASTE, RECYCLING, AND HOUSEKEEPING

    E-print Network

    Howitt, Ivan

    RETHINKING WASTE, RECYCLING, AND HOUSEKEEPING EFFICIENCY.EFFICIENCY. A l GA leaner Green #12 t R li Management Recycling Staff The Office of Waste Reduction & Recycling started in The Office of Waste Reduction & Recycling started in 1990, we have 14 full time staff positions. ·We collect over 40

  9. Nottingham Trent University Plastic Recycling

    E-print Network

    Evans, Paul

    5015/03/08 Nottingham Trent University Plastic Recycling Water and fizzy drinks bottles the caps from any bottles you recycle. Please rinse all plastic bottles and containers before putting them in the recycling bins. #12;5015/03/08 Nottingham Trent University Paper Recycling Office paper Catalogues

  10. RECYCLING RATE STUDY Prepared by

    E-print Network

    Laughlin, Robert B.

    NATIONAL RECYCLING RATE STUDY Prepared by: Smith, Bucklin and Associates, Inc. Market Research and Statistics Division Chicago, Illinois July 2003 PRINTED ON RECYCLED PAPER #12;BCI RECYCLING RATE STUDY TABLE ....................................................................................................1 II. METHODOLOGY A. Total Pounds of Lead Recycled from Batteries

  11. CHERRY: CHECKPOINTED EARLY RESOURCE RECYCLING

    E-print Network

    Torrellas, Josep

    1 2 3 CHERRY: CHECKPOINTED EARLY RESOURCE RECYCLING Jos´e F. Mart´inez1 , Jose Renau2 Michael C. Huang3 , Milos Prvulovic2 , and Josep Torrellas2 #12;Cherry: Checkpointed Early Resource Recycling: Decouple recycling from retirement #12;Cherry: Checkpointed Early Resource Recycling in Out

  12. Desulfurization in the reducing state and denitrification with ammonia injection in an FBC test facility

    Microsoft Academic Search

    Zhong Zhaoping; Lan Jixiang

    1998-01-01

    The second generation PFBC-CC, IGCC, and the technology of staged combustion to lower emissions of NOx raise questions about the desulfurization efficiency under reducing atmosphere. This paper describes desulfurization tests in reducing atmosphere in a fluidized bed combustor with the application of the fly-ash recycle and two-staged combustion technologies. Also, ammonia injection was carried out. Results show that desulfurization in

  13. A Practical Recycling Project . . .

    ERIC Educational Resources Information Center

    Durant, Raymond H.; Mikuska, James M.

    1973-01-01

    Descirbes a school district's recycling program of aluminum lunch trays that are collected after their use. The trays are used as scrap metal in industrial education workshop and used for sand castings. (PS)

  14. Making Recycled Paper

    NSDL National Science Digital Library

    American Chemical Society

    2011-01-01

    In this activity on page 11 of the PDF, learners follow simple steps to recycle old newspaper into new paper. Use this activity to introduce conservation as well as the chemistry of cellulose and how paper products are made.

  15. Reduce, Reuse, Recycle

    NSDL National Science Digital Library

    WGBH Educational Foundation

    2010-11-30

    In this media-rich lesson featuring LOOP SCOOPS videos, students consider how the concept of needs vs. wants can help them think about ways to protect Earth's natural resources by reducing, reusing, and recycling materials.

  16. Climate Kids: Recycle This!

    NSDL National Science Digital Library

    The site features an online game in which participants keep recyclable items out of the trash by guiding them into proper bins. Accompanying the game is a list of three categories of items that can be recycled, along with the benefits of doing so. This lesson is part of the Climate Kids website, a NASA education resource featuring articles, videos, images and games focused on the science of climate change.

  17. Recycling of composite materials

    Microsoft Academic Search

    M. Buggy; L. Farragher; W. Madden

    1995-01-01

    An economic survey of composite manufacturing was carried out to help to identify suitable fibre\\/resin systems for recycling trials. Three separate recycling strategies were also adopted. The first of these was the re-use of in-process polyester\\/glass prepreg offcuts, which were quantified and then reprocessed using a simple pressing technique. Three different panel types were pressed and subjected to comparative physical

  18. Recycling of PET

    Microsoft Academic Search

    Firas Awaja; Dumitru Pavel

    2005-01-01

    The recycling of post-consumer PET (POSTC-PET) as a technology is a cross-disciplinary practice with many fields of science involved. These include polymer chemistry and physics, process engineering and manufacturing engineering. This paper presents a concise background of the current state of knowledge with respect to POSTC-PET recycling covering the disciplines mentioned above. In the first section of this paper, a

  19. Recycling of nonmetallics

    USGS Publications Warehouse

    Amey, E.B.; Kelly, T.D.

    1996-01-01

    The first factor determining recyclability is the composition of the material itself. Metals, for example, can be reused with little or no loss in quality. Paper and rubber, by this criterion, are less recyclable. Each time paper is recycled, some cellulose fibers are broken. Shorter fibers can mean weaker paper of perceived lower quality and value. Vulcanizing is an irreversible chemical process that precludes recycling rubber in its original form. Both materials may be reused in other applications often of lower value than the original one. To be recyclable, the discarded material must have a collection infrastructure at the source of waste generation, at a central collection site, or at curbside. The recovered material must also have a market. If it is priced noncompetitively or no market exists, if it does not meet specifications, or if it requires special technology investments which cannot be recovered through future sales, the recovered material may be stockpiled or discarded rather than recycled. ?? 1996 International Association for Mathematical Geology.

  20. Cooperation percolation in spatial prisoner's dilemma game

    E-print Network

    Yang, Han-Xin; Wang, Wen-Xu

    2015-01-01

    The paradox of cooperation among selfish individuals still puzzles scientific communities. Although a large amount of evidence has demonstrated that cooperator clusters in spatial games are effective to protect cooperators against the invasion of defectors, we continue to lack the condition for the formation of a giant cooperator cluster that assures the prevalence of cooperation in a system. Here, we study the dynamical organization of cooperator clusters in spatial prisoner's dilemma game to offer the condition for the dominance of cooperation, finding that a phase transition characterized by the emergence of a large spanning cooperator cluster occurs when the initial fraction of cooperators exceeds a certain threshold. Interestingly, the phase transition belongs to different universality classes of percolation determined by the temptation to defect $b$. Specifically, on square lattices, $1percolation, whereas $3/2

  1. Abrupt percolation in small equilibrated networks

    NASA Astrophysics Data System (ADS)

    Matsoukas, Themis

    2015-05-01

    Networks can exhibit an abrupt transition in the form of a spontaneous self-organization of a sizable fraction of the population into a giant component of connected members. This behavior has been demonstrated in random graphs under suppressive rules that passively or actively attempt to delay the formation of the giant cluster. We show that suppressive rules are not a necessary condition for a sharp transition at the percolation threshold. Rather, a finite system with aggressive tendency to form a giant cluster may exhibit an instability at the percolation threshold that is relieved through an abrupt and discontinuous transition to the stable branch. We develop the theory for a class of equilibrated networks that produce this behavior and find that the discontinuous jump is especially pronounced in small networks but disappears when the size of the system is infinite.

  2. Precision calculation of elasticity for percolation

    NASA Astrophysics Data System (ADS)

    Zabolitzky, J. G.; Bergman, D. J.; Stauffer, D.

    1986-07-01

    Monte Carlo transfer matrix evaluation of the elastic constants at the percolation threshold of the random-bond honeycomb lattice, with widths of up to 96 and lengths of about two million lattice constants (roughly 200 hours CDC Cyber 205 vector computer time) gave a critical exponent T=3.96±0.04 with a logarithmic correction term. This exponent agrees well with the scaling hypothesis T=t+2v=3.97, relating T to the two-dimensional conductivity exponent.

  3. Conformal invariance in two-dimensional percolation

    Microsoft Academic Search

    Robert Langlands; Philippe Pouliot; Yvan Saint-Aubin

    1994-01-01

    The immediate purpose of the paper was neither to review the basic\\u000adefinitions of percolation theory nor to rehearse the general physical notions\\u000aof universality and renormalization (an important technique to be described in\\u000aPart Two). It was rather to describe as concretely as possible, although in\\u000ahypothetical form, the geometric aspects of universality, especially conformal\\u000ainvariance, in the context

  4. Arm exponents in high dimensional percolation

    E-print Network

    Gady Kozma; Asaf Nachmias

    2009-11-04

    We study the probability that the origin is connected to the sphere of radius r (an arm event) in critical percolation in high dimensions, namely when the dimension d is large enough or when d>6 and the lattice is sufficiently spread out. We prove that this probability decays like 1/r^2. Furthermore, we show that the probability of having k disjoint arms to distance r emanating from the vicinity of the origin is 1/r^2k.

  5. Molecular Mechanisms of Renal Ammonia Transport

    PubMed Central

    Weiner, I. David; Hamm, L. Lee

    2015-01-01

    Acid-base homeostasis to a great extent relies on renal ammonia metabolism. In the past several years, seminal studies have generated important new insights into the mechanisms of renal ammonia transport. In particular, the theory that ammonia transport occurs almost exclusively through nonionic NH3 diffusion and NH4+ trapping has given way to a model postulating that a variety of proteins specifically transport NH3 and NH4+ and that this transport is critical for normal ammonia metabolism. Many of these proteins transport primarily H+ or K+ but also transport NH4+. Nonerythroid Rh glycoproteins transport ammonia and may represent critical facilitators of ammonia transport in the kidney. This review discusses the underlying aspects of renal ammonia transport as well as specific proteins with important roles in renal ammonia transport. PMID:17002591

  6. Diethylamine and ammonia pretreatment of lignocellulose 

    E-print Network

    Holthus, Robert Earl

    1993-01-01

    to the diethylamine did not increase reactivity, but it allows the diethylamine to be recovered. In addition to the diethylamine experiments, ammonia was used to pretreat Coastal bermudagrass. This process involves soaking the cellulose fibers in liquid ammonia...

  7. Catalytic Organometallic Reactions of Ammonia

    PubMed Central

    Klinkenberg, Jessica L.

    2012-01-01

    Until recently, ammonia had rarely succumbed to catalytic transformations with homogeneous catalysts, and the development of such reactions that are selective for the formation of single products under mild conditions has encountered numerous challenges. However, recently developed catalysts have allowed several classes of reactions to create products with nitrogen-containing functional groups from ammonia. These reactions include hydroaminomethylation, reductive amination, alkylation, allylic substitution, hydroamination, and cross-coupling. This Minireview describes examples of these processes and the factors that control catalyst activity and selectivity. PMID:20857466

  8. Analogy and Difference between Gelation and Percolation Process

    E-print Network

    Kazumi Suematsu

    2004-10-06

    It has been verified that the theory of gelation with cyclization effects is in good accord with experimental observations of gel points and gel fractions. Encouraged by this success we scrutinize the prediction limit of the theory through the rigor of the bond percolation theory. Significant disparity is found between the prediction of the gelation theory and that of the percolation theory. To find the reason of the disparity, we re-examine the distribution function of bond animals; the analysis showing that the percolation process differs from real gelations in two points: (i) whereas the real gelation obeys the principle of equireactivity of functional units, the percolation process does not; (ii) the substantial reduction of functionality occurs through the percolation process. These make the lattice model intrinsically different from real chemical processes. As a result, one can not make use of the percolation theory for the purpose of examining the validity of the gelation theory.

  9. Continuum percolation of carbon nanotubes in polymeric and colloidal media

    PubMed Central

    Kyrylyuk, Andriy V.; van der Schoot, Paul

    2008-01-01

    We apply continuum connectedness percolation theory to realistic carbon nanotube systems and predict how bending flexibility, length polydispersity, and attractive interactions between them influence the percolation threshold, demonstrating that it can be used as a predictive tool for designing nanotube-based composite materials. We argue that the host matrix in which the nanotubes are dispersed controls this threshold through the interactions it induces between them during processing and through the degree of connectedness that must be set by the tunneling distance of electrons, at least in the context of conductivity percolation. This provides routes to manipulate the percolation threshold and the level of conductivity in the final product. We find that the percolation threshold of carbon nanotubes is very sensitive to the degree of connectedness, to the presence of small quantities of longer rods, and to very weak attractive interactions between them. Bending flexibility or tortuosity, on the other hand, has only a fairly weak impact on the percolation threshold. PMID:18550818

  10. Percolation in a Proton Exchange Membrane Fuel Cell Catalyst Layer

    SciTech Connect

    Stacy, Stephen; Allen, Jeffrey

    2012-07-01

    Water management in the catalyst layers of proton exchange membrane fuel cells (PEMFC) is confronted by two issues, flooding and dry out, both of which result in improper functioning of the fuel cell and lead to poor performance and degradation. At the present time, the data that has been reported about water percolation and wettability within a fuel cell catalyst layer is limited. A method and apparatus for measuring the percolation pressure in the catalyst layer has been developed based upon an experimental apparatus used to test water percolation in porous transport layers (PTL). The experimental setup uses a pseudo Hele-Shaw type testing where samples are compressed and a fluid is injected into the sample. Testing the samples gives percolation pressure plots which show trends in increasing percolation pressure with an increase in flow rate. A decrease in pressure was seen as percolation occurred in one sample, however the pressure only had a rising effect in the other sample.

  11. Cell Invasion in Collagen Scaffold Architectures Characterized by Percolation Theory

    E-print Network

    Ashworth, Jennifer C.; Mehr, Marco; Buxton, Paul G.; Best, Serena M.; Cameron, Ruth E.

    2015-04-16

    , Switzerland. Keywords: collagen scaffolds, cell invasion, scaffold characterization, interconnectivity, percolation Collagen scaffolds are biological templates for the regeneration of damaged or diseased tissues. Since cell invasion into these porous... Where ? is a percolation constant with value 0.88 for 3D systems.[26] Measurements of d were plotted as a function of 𝐿? 1 𝜈 to allow calculation of the intercept: the percolation diameter, dc. Cell Culture: Human periodontal ligament fibroblasts...

  12. AMMONIA CONCENTRATION IN SALTSTONE HEADSPACE SUMMARY REPORT

    Microsoft Academic Search

    J Zamecnik; A Alex Cozzi

    2008-01-01

    The Saltstone Facility Documented Safety Analysis (DSA) is under revision to accommodate changes in the Composite Lower Flammability Limit (CLFL) from the introduction of Isopar into Tank 50. Saltstone samples were prepared with an 'MCU' type salt solution spiked with ammonia. The ammonia released from the saltstone was captured and analyzed. The ammonia concentration found in the headspace of samples

  13. Using ammonia as a sustainable fuel

    Microsoft Academic Search

    C. Zamfirescu; I. Dincer

    2008-01-01

    In this study, ammonia is identified as a sustainable fuel for mobile and remote applications. Similar to hydrogen, ammonia is a synthetic product that can be obtained either from fossil fuels, biomass, or other renewable sources. Some advantages of ammonia with respect to hydrogen are less expensive cost per unit of stored energy, higher volumetric energy density that is comparable

  14. 7, 1413914169, 2007 Ammonia at Blodgett

    E-print Network

    Paris-Sud XI, Université de

    ACPD 7, 14139­14169, 2007 Ammonia at Blodgett Forest M. L. Fischer and D. Littlejohn Title Page Chemistry and Physics Discussions Ammonia at Blodgett Forest, Sierra Nevada, USA M. L. Fischer and D­14169, 2007 Ammonia at Blodgett Forest M. L. Fischer and D. Littlejohn Title Page Abstract Introduction

  15. Recycling of Reinforced Plastics

    NASA Astrophysics Data System (ADS)

    Adams, R. D.; Collins, Andrew; Cooper, Duncan; Wingfield-Digby, Mark; Watts-Farmer, Archibald; Laurence, Anna; Patel, Kayur; Stevens, Mark; Watkins, Rhodri

    2014-02-01

    This work has shown is that it is possible to recycle continuous and short fibre reinforced thermosetting resins while keeping almost the whole of the original material, both fibres and matrix, within the recyclate. By splitting, crushing hot or cold, and hot forming, it is possible to create a recyclable material, which we designate a Remat, which can then be used to remanufacture other shapes, examples of plates and tubes being demonstrated. Not only can remanufacturing be done, but it has been shown that over 50 % of the original mechanical properties, such as the E modulus, tensile strength, and interlaminar shear strength, can be retained. Four different forms of composite were investigated, a random mat Glass Fibre Reinforced Plastic (GFRP) bathroom component and boat hull, woven glass and carbon fibre cloth impregnated with an epoxy resin, and unidirectional carbon fibre pre-preg. One of the main factors found to affect composite recyclability was the type of resin matrix used in the composite. Thermoset resins tested were shown to have a temperature range around the Glass Transition Temperature (Tg) where they exhibit ductile behaviour, hence aiding reforming of the material. The high-grade carbon fibre prepreg was found to be less easy to recycle than the woven of random fibre laminates. One method of remanufacturing was by heating the Remat to above its glass transition temperature, bending it to shape, and then cooling it. However, unless precautions are taken, the geometric form may revert. This does not happen with the crushed material.

  16. Understanding and predicting deep percolation under surface irrigation

    NASA Astrophysics Data System (ADS)

    Bethune, M. G.; Selle, B.; Wang, Q. J.

    2008-12-01

    A lysimeter experiment was conducted in southeastern Australia to quantify the deep percolation response under irrigated pasture to different soil types, water table depths, and ponding times during surface irrigation. Deep percolation was governed by the final infiltration rate of the subsoil, the ponding time, the water table depth, and the amount of water stored in the rootzone between saturation and field capacity. These key variables were used to characterize both steady- and nonsteady-state percolation in a conceptual model of deep percolation. The conceptual model was found to provide an effective representation of deep percolation for both the lysimeter and field-scale water balance data. Steady-state percolation during irrigation was the dominant process contributing to deep percolation on most of the studied soils. Nonsteady-state percolation (redistribution) was very important for the sandiest soil type. The conceptual model provided better prediction of deep percolation than both data-based model (artificial neural network) and process-based modeling approach (1-D Richards' equation model).

  17. Leaf-excluded percolation in two and three dimensions

    NASA Astrophysics Data System (ADS)

    Zhou, Zongzheng; Xu, Xiao; Garoni, Timothy M.; Deng, Youjin

    2015-02-01

    We introduce the leaf-excluded percolation model, which corresponds to independent bond percolation conditioned on the absence of leaves (vertices of degree one). We study the leaf-excluded model on the square and simple-cubic lattices via Monte Carlo simulation, using a worm-like algorithm. By studying wrapping probabilities, we precisely estimate the critical thresholds to be 0.355 247 5 (8 ) (square) and 0.185 022 (3 ) (simple-cubic). Our estimates for the thermal and magnetic exponents are consistent with those for percolation, implying that the phase transition of the leaf-excluded model belongs to the standard percolation universality class.

  18. Ammonia excretion by Azobacter chroococcum

    Microsoft Academic Search

    N. Narula; K. Lakshminarayana; P. Tauro

    1981-01-01

    In recent years, research has focused attention on the development of biological systems for nitrogen fixation. In this report, two strains of Azotobacter chroococcum are identified which can excrete as much as 45 mg ammonia\\/ml of the culture broth in a sucrose supplemented synthetic medium.

  19. Hydrogen production using ammonia borane

    DOEpatents

    Hamilton, Charles W; Baker, R. Thomas; Semelsberger, Troy A; Shrestha, Roshan P

    2013-12-24

    Hydrogen ("H.sub.2") is produced when ammonia borane reacts with a catalyst complex of the formula L.sub.nM-X wherein M is a base metal such as iron, X is an anionic nitrogen- or phosphorus-based ligand or hydride, and L is a neutral ancillary ligand that is a neutral monodentate or polydentate ligand.

  20. Scrap tire recycling

    SciTech Connect

    Lula, J.W.; Bohnert, G.W.

    1997-03-01

    As the automobile tire technology has grown and met the need for safer and more durable tires, stronger reinforcement and more chemically resistant rubber compounds have made recycling tires more difficult. In an effort to resolve this problem, techniques and equipment were developed to grind tires into small pieces, and new markets were sought to utilize the crumb rubber product streams from ground tires. Industrial combustion processes were modified to accept scrap tires as fuel. These efforts have been beneficial, steadily increasing the percentage of scrap tires recycled to about 10% in 1985, and reaching 72% in 1995. By the end of 1997, fully 100% of tires generated in the U.S. are expected to be recycled.

  1. Chemical Recycling of Polyurethanes and Applications for the Recyclates

    Microsoft Academic Search

    K. K. You; D. T. Durocher; P. Ch. Kierkus; T. L. Fishback

    1998-01-01

    The recycling of thermoset materials, including polyurethane, has always posed unique challenges. Traditional approaches to recycling such materials include mechanical regrinding and the use of the regrind as filler. Chemical recycling of polyurethanes by such means as hydrolysis, aminolysis, and glycolysis, is for the most part considered economically uncompetitive compared to formulating with virgin raw materials. To protect our environment

  2. Recycled Aluminum Ornaments

    NSDL National Science Digital Library

    Wishart, Ray

    This lesson plan from ATEEC will explain the principles of recycling. The activity would be most appropriate for technology studies or high school science classes. In all, it would require 2-5 hours of class time to complete. The purpose of the lesson is to demonstrate how aluminum is recycled. This laboratory activity does require some special equipment including a heat source capable of melting aluminum and an outdoor work area. Extension activities are also provided. The lesson plan is available for download as a PDF; users must create a free, quick login with ATEEC to access the materials.

  3. Power recycling for an interferometric gravitational wave

    E-print Network

    Ejiri, Shinji

    THESIS Power recycling for an interferometric gravitational wave detector Masaki Ando Department . . . . . . . . . . . . . . 48 3.3 Power recycling . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 3.3.1 Principle of power recycling . . . . . . . . . . . . . . . . . 50 3.3.2 Recycling cavity

  4. Urban waste recycling in Taiwan

    Microsoft Academic Search

    Gordon C. C. Yang

    1995-01-01

    The urban waste recycling program in Taiwan is discussed. During the past few years, the quantity of urban waste generated in Taiwan has greatly increased, about 8–10% per year. Approx., 50 wt.% or more of the waste items in urban waste are found to be valuable and worth recycling. Recycling is of much significance to Taiwan because of a lack

  5. PITT RECYCLES! *Please empty cans!

    E-print Network

    Sibille, Etienne

    PITT RECYCLES! Steel Aluminum Tin cans *Please empty cans! *Please empty containers! *Plastic bags can be recycled at Giant Eagle and Trader Joe's. Look on the bottom or the side of the container NOT Recyclable... Food waste Lunch bags Coffee cups Cellophane Tissues Paper towels Carbon paper Styrofoam Metals

  6. Recycling Behavior: A Multidimensional Approach

    ERIC Educational Resources Information Center

    Meneses, Gonzalo Diaz; Palacio, Asuncion Beerli

    2005-01-01

    This work centers on the study of consumer recycling roles to examine the sociodemographic and psychographic profile of the distribution of recycling tasks and roles within the household. With this aim in mind, an empirical work was carried out, the results of which suggest that recycling behavior is multidimensional and comprises the undertaking…

  7. Antiproton stacking in the Recycler

    SciTech Connect

    Alexey Burov

    2003-06-23

    Possibilities to accumulate antiprotons in the Recycler are considered for three different cases: with current stochastic cooling, with upgraded stochastic cooling and with electron cooling. With stochastic cooling only, even upgraded, Recycler looks hardly useful. However, with electron cooling at its goal parameters and reasonably good vacuum in the Recycler, this machine would be efficient.

  8. Recycled concrete aggregates

    Microsoft Academic Search

    Nik. D. Oikonomou

    2005-01-01

    The subject of concrete recycling is regarded as very important in the general attempt for sustainable development in our times. In a parallel manner, it is directly connected with (a) increase of demolition structures past out of performance time, (b) demand for new structures and (c) results––especially in Greece––of destruction by natural phenomena (earthquakes, etc.). The present paper refers to

  9. Helium-Recycling Plant

    NASA Technical Reports Server (NTRS)

    Cook, Joseph

    1996-01-01

    Proposed system recovers and stores helium gas for reuse. Maintains helium at 99.99-percent purity, preventing water vapor from atmosphere or lubricating oil from pumps from contaminating gas. System takes in gas at nearly constant low back pressure near atmospheric pressure; introduces little or no back pressure into source of helium. Concept also extended to recycling of other gases.

  10. Recycling and Restoration

    NSDL National Science Digital Library

    KET

    2011-01-11

    This video explains how Bernheim Arboretum and Research Forest near Louisville, Kentucky used recycled cypress from pickle vats to build its visitor center and then “paid back” nature by creating a cypress-tupelo swamp at one end of a lake on the park grounds.

  11. RECYCLABILITY INDEX FOR AUTOMOBILES

    EPA Science Inventory

    The project's purpose is to create a rating system for the ecological impacts of vehicles at the end of their life based on recyclability, toxic material content, and ultimate disposal. Each year, 10-11 million vehicles are retired from service in the United States. The vehi...

  12. Computer Recycling Farm USA

    USGS Multimedia Gallery

    USGS conducted a study of plastic pollution at this rural US site in the Midwest.  The recycler was receiving computers from companies at a rate which greatly exceeded the capacity of the operation.  Approximately 50,000 computers remained outdoors on 15 acres for nearly a decade.  The site has sinc...

  13. Modied invasion percolation model for fracking

    NASA Astrophysics Data System (ADS)

    Norris, J.; Turcotte, D. L.; Rundle, J. B.

    2013-12-01

    Recent developments in hydraulic fracturing (fracking) have enabled the recovery of large reserves of natural gas and oil. These developments include a change from low-volume, high-viscosity fluid injection to high-volume, low-viscosity injection. We consider new models of Invasion Percolation, (IP) which are models that were originally introduced to represent the injection of an invading fluid into a fluid filled porous medium. A primary difference between our model and the original model is the elimination of any unbroken bonds whose end sites are both filled with fluid. While the original model was found to have statistics nearly identical to traditional percolation, we find significant statistical differences. In particular, the distribution of broken bond strengths displays a strong roll-over near the critical point. Another difference between traditional percolation clusters and clusters generated using our model is the absence of internal loops. The modified growth rule prevents the formation of internal loops making the growing cluster ramified. Other ramified networks include drainage basins and DLA clusters. The study of drainage basins led to the development of Horton-Strahler and Tokunaga network statistics. We used both Horton-Strahler and Tokunaga network statistics to characterize simulated clusters using and found that the clusters generated by our model are statistically self-similar fractals. In addition to fractal clusters, IP also displays burst dynamics, in which the cluster extends rapidly through a spontaneous extension of percolating bonds. We define a burst to be a consecutive series of broken bonds whose strengths are all below a specified value. Using this definition of bursts we found good agreement with a power-law frequency-area distribution. Our model displays many of the characteristics of an energy landscape, and shows many similarities to DLA, neural networks, ecological landscapes, and the world wide web. We anticipate that this new class of models will have broad applicability to the study of instabilities in high dimensional complex networks, a topic of considerable interest across a wide array of fields.

  14. Local Cluster Aggregation Models of Explosive Percolation

    NASA Astrophysics Data System (ADS)

    D'Souza, Raissa M.; Mitzenmacher, Michael

    2010-05-01

    We introduce perhaps the simplest models of graph evolution with choice that demonstrate discontinuous percolation transitions and can be analyzed via mathematical evolution equations. These models are local, in the sense that at each step of the process one edge is selected from a small set of potential edges sharing common vertices and added to the graph. We show that the evolution can be accurately described by a system of differential equations and that such models exhibit the discontinuous emergence of the giant component. Yet they also obey scaling behaviors characteristic of continuous transitions, with scaling exponents that differ from the classic Erd?s-Rényi model.

  15. Percolation in multi-hop wireless networks Massimo Franceschetti1

    E-print Network

    Meester, Ronald

    provide some long-distance communi- cation. He shows the existence of a critical value c for the density percolates) with probability one, and so long-distance multi-hop communication is possible. In the past fortyPercolation in multi-hop wireless networks Massimo Franceschetti1 , Lorna Booth, Matthew Cook2

  16. Understanding and predicting deep percolation under surface irrigation

    Microsoft Academic Search

    M. G. Bethune; B. Selle; Q. J. Wang

    2008-01-01

    A lysimeter experiment was conducted in southeastern Australia to quantify the deep percolation response under irrigated pasture to different soil types, water table depths, and ponding times during surface irrigation. Deep percolation was governed by the final infiltration rate of the subsoil, the ponding time, the water table depth, and the amount of water stored in the rootzone between saturation

  17. Introduction to Network Science 1 Percolation and Network Resilience

    E-print Network

    Safro, Ilya

    Introduction to Network Science 1 Percolation and Network Resilience Percolation is a process;Introduction to Network Science 3 j is on and its k neighbors are not in gc Reminder: excess degree to exist #12;Introduction to Network Science 4 #12;Introduction to Network Science 5 #12;Introduction

  18. Inverse cascade in percolation model: hierarchical description of ...

    E-print Network

    2004-11-01

    Nov 1, 2004 ... Noteworthy, we are interested not in a final solution of a percolation. 2 ..... naturally explained by the Discrete Scale Invariance (DSI) [31], which ..... of percolation and reported several characteristic phenomena observed as ? ? ?c. ... It would be interesting to check this condition in real systems tradition-.

  19. FINITE CONNECTIONS FOR SUPERCRITICAL BERNOULLI BOND PERCOLATION IN 2D

    E-print Network

    FINITE CONNECTIONS FOR SUPERCRITICAL BERNOULLI BOND PERCOLATION IN 2D MASSIMO CAMPANINO, DMITRY for super-critical Bernoulli bond percolation on Z2 . These asymptotics are based on a detailed fluctuation analysis of long finite super-critical clusters or, more precisely, of dual open (sub-critical) loops which

  20. Sizes of the largest clusters for supercritical percolation

    E-print Network

    Paris-Sud XI, Université de

    Sizes of the largest clusters for supercritical percolation on random recursive trees Jean Bertoin Abstract We consider Bernoulli bound-percolation on a random recursive tree of size n 1, with supercritical and are distributed according to some Poisson random measure. Key words: Random recursive tree, supercritical bound

  1. Sizes of the largest clusters for supercritical percolation

    E-print Network

    Paris-Sud XI, Université de

    Sizes of the largest clusters for supercritical percolation on random recursive trees Jean Bertoin Abstract We consider Bernoulli bond-percolation on a random recursive tree of size n 1, with supercritical and are distributed according to some Poisson random measure. Key words: Random recursive tree, supercritical bond

  2. On monochromatic arm exponents for 2D critical percolation

    E-print Network

    Paris-Sud XI, Université de

    On monochromatic arm exponents for 2D critical percolation Vincent Beffara Pierre Nolin Abstract We investigate the so-called monochromatic arm exponents for critical percolation in two dimensions main result is that the monochromatic j-arm exponent is strictly between the polychromatic j-arm and (j

  3. Percolation Approach to Study Connectivity in Living Neural Networks

    E-print Network

    Tlusty, Tsvi

    Percolation Approach to Study Connectivity in Living Neural Networks Jordi Soriano, Ilan Breskin distribution and not a power law one. Keywords: neural networks, graphs, connectivity, percolation, giant as the fundamental feature to understand the potential of a living neural network. Unravelling the detailed

  4. Electrical and Rheological Percolation in Polystyrene/MWCNT Nanocomposites

    E-print Network

    Raghavan, Srinivasa

    Electrical and Rheological Percolation in Polystyrene/MWCNT Nanocomposites Arun K. Kota, Bani H the formation of a percolated MWCNT network that responds elastically over long timescales. Network formation relatively high content of hydrogen. The resulting PS/MWCNT nanocomposites are processed from solution using

  5. Percolation of aligned dimers on a square lattice

    NASA Astrophysics Data System (ADS)

    Cherkasova, V. A.; Tarasevich, Y. Y.; Lebovka, N. I.; Vygornitskii, N. V.

    2010-03-01

    Percolation and jamming phenomena were investigated for anisotropic sequential deposition of dimers (particles occupying two adjacent adsorption sites) on a square lattice. The influence of dimer alignment on the electrical conductivity was examined. The percolation threshold for deposition of dimers was lower than for deposition of monomers. Nevertheless, the problem belongs to the universality class of random percolation. The lowest percolation threshold (pc = 0.562) was observed for isotropic orientation of the dimers. It was higher (pc = 0.586) in the case of dimers aligned strictly along one direction. The state of dimer orientation influenced the concentration dependence of the electrical conductivity. The proposed model seems to be useful for description of the percolating properties of anisotropic conductors.

  6. Charge percolation pathways guided by defects in quantum dot solids.

    PubMed

    Zhang, Yingjie; Zherebetskyy, Danylo; Bronstein, Noah D; Barja, Sara; Lichtenstein, Leonid; Schuppisser, David; Wang, Lin-Wang; Alivisatos, A Paul; Salmeron, Miquel

    2015-05-13

    Charge hopping and percolation in quantum dot (QD) solids has been widely studied, but the microscopic nature of the percolation process is not understood or determined. Here we present the first imaging of the charge percolation pathways in two-dimensional PbS QD arrays using Kelvin probe force microscopy (KPFM). We show that under dark conditions electrons percolate via in-gap states (IGS) instead of the conduction band, while holes percolate via valence band states. This novel transport behavior is explained by the electronic structure and energy level alignment of the individual QDs, which was measured by scanning tunneling spectroscopy (STS). Chemical treatments with hydrazine can remove the IGS, resulting in an intrinsic defect-free semiconductor, as revealed by STS and surface potential spectroscopy. The control over IGS can guide the design of novel electronic devices with impurity conduction, and photodiodes with controlled doping. PMID:25844919

  7. Ammonia health effects. Final report

    SciTech Connect

    Carson, B.L.; Ellis, H.V. III; Beall, C.M.; Baker, L.H.

    1981-09-01

    Health effects literature primarily related to inhalation exposures to ammonia was collected, evaluated, tabulated, and summarized. Approximately 200 documents were collected from computerized and manual literature searches covering the period 1886-1981. Pharmacologists and an M.D. epidemiologist rated the documents according to their applicability to the study and their methodology. The approximately 50 documents considered useful for deriving a range of concern for human exposure to ammonia from automotive emissions were tabulated. The 50 pages of tables detail the results of acute, repeated dose, and chronic testing of bats, mice, rats, guinea pigs, chickens, rabbits, cats, monkeys, dogs, turkeys, swine, and humans as well as human occupational and accidental studies. Most of the documents evaluated are described in an annotated bibliography.

  8. Ammonia abundances in four comets

    NASA Technical Reports Server (NTRS)

    Wickoff, Susan; Tegler, Stephen C.; Engel, Lisa

    1991-01-01

    NH2 emission band strengths were measured in four comets and the NH2 column densities were determined in order to measure the ammonia content of the comets. The mean ammonia/water abundance ratio derived for the four comets is found to be 0.13 + or - 0.06 percent, with no significant variation among the comets. The uniformity of this abundance attests to a remarkable degree of chemical homogeneity over large scales in the comet-forming region of the primordial solar nebula, and contrasts with the CO abundance variations found previously in comets. The N2 and NH3 abundances indicate a condensation temperature in the range 20-160 K, consistent with virtually all comet formation hypotheses.

  9. The Fernald Waste Recycling Program

    SciTech Connect

    Motl, G.P.

    1993-10-26

    Recycling is considered a critical component of the waste disposition strategy at the Fernald Plant. It is estimated that 33 million cubic feet of waste will be generated during the Fernald cleanup. Recycling some portion of this waste will not only conserve natural resources and disposal volume but will, even more significantly, support the preservation of existing disposition options such as off-site disposal or on-site storage. Recognizing the strategic implications of recycling, this paper outlines the criteria used at Fernald to make recycle decisions and highlights several of Fernald`s current recycling initiatives.

  10. Correlation effects in nanoparticle composites: Percolation, packing and tunneling

    NASA Astrophysics Data System (ADS)

    Mukherjee, Rupam

    Percolation is one of the most fundamental and far-reaching physical phenomena, with major implications in a vast variety of fields. The work described in this thesis aims to understand the role of percolation effects in various, seemingly unrelated phenomena, such as the dielectric permittivity of metal-insulator composites, tunneling percolation, and the relationship between percolation and filling factors. Specifically, we investigated 1) the very large enhancement of the dielectric permittivity of a composite metal -- insulator system, RuO2 - CaCu3Ti4O12 (CCTO) near the percolation threshold. For RuO2/CCTO composites, an increase in the real part of the dielectric permittivity (initially about 10 3-104 at 10 kHz) by approximately an order of magnitude is observed in the vicinity of the percolation threshold. 2) In the same system, apart from a classical percolation transition associated with the appearance of a continuous conductance path through RuO2 nanoparticles, at least two additional tunneling percolation transitions are detected. Such behavior is consistent with the recently emerged picture of a quantum conductivity staircase, which predicts several percolation tunneling thresholds in a system with a hierarchy of local tunneling conductance, due to various degrees of proximity of adjacent conducting particles distributed in an insulating matrix. 3) The filling factors of the composites of nanoparticles with different shapes have been studied as a function of volume fraction. Interestingly, like percolation, filling factors also obey critical power law behavior as a function of size ratio of constituent particles.

  11. OTEC ammonia turbine design study

    Microsoft Academic Search

    C. H. Kostors; S. P. Vincent

    1979-01-01

    The design of an ammonia turbine generator for OTEC which uses high-performance state-of-the-art hardware is presented. Turbine aerodynamic performance was calculated using a modification of the Ainley and Mathieson (1951) pressure loss method to determine thermodynamic conditions at various locations within the turbine for a given geometry on the basis of mass flow continuity. It is found that the optimum

  12. Percolation on networks with conditional dependence group.

    PubMed

    Wang, Hui; Li, Ming; Deng, Lin; Wang, Bing-Hong

    2015-01-01

    Recently, the dependence group has been proposed to study the robustness of networks with interdependent nodes. A dependence group means that a failed node in the group can lead to the failures of the whole group. Considering the situation of real networks that one failed node may not always break the functionality of a dependence group, we study a cascading failure model that a dependence group fails only when more than a fraction ? of nodes of the group fail. We find that the network becomes more robust with the increasing of the parameter ?. However, the type of percolation transition is always first order unless the model reduces to the classical network percolation model, which is independent of the degree distribution of the network. Furthermore, we find that a larger dependence group size does not always make the networks more fragile. We also present exact solutions to the size of the giant component and the critical point, which are in agreement with the simulations well. PMID:25978634

  13. Percolation of Blast Waves though Sand

    NASA Astrophysics Data System (ADS)

    Proud, William

    2013-06-01

    Previous research has concentrated on the physical processes occurring when samples of sand, of varying moisture content, were shock compressed. In this study quartz sand samples are subjected to blast waves over a range of pressure and duration. Aspects of particle movement are discussed; the global movement of a bed hundreds of particles thick is a fraction of particle width. The main diagnostics used are pressure sensors and high-speed photography. Results are presented for a range of particle sizes, aspect ratio, density and moisture content. While the velocity of the percolation through the bed is primarily controlled by density and porosity the effect of moisture reveals a more complex dependence. Previous research has concentrated on the physical processes occurring when samples of sand, of varying moisture content, were shock compressed. In this study quartz sand samples are subjected to blast waves over a range of pressure and duration. Aspects of particle movement are discussed; the global movement of a bed hundreds of particles thick is a fraction of particle width. The main diagnostics used are pressure sensors and high-speed photography. Results are presented for a range of particle sizes, aspect ratio, density and moisture content. While the velocity of the percolation through the bed is primarily controlled by density and porosity the effect of moisture reveals a more complex dependence. The ISP acknowledges the support of the Atomic Weapons Establishment and Imperial College London.

  14. Fiber-Optic Ammonia Sensors

    NASA Technical Reports Server (NTRS)

    Carter, Michael T.

    2003-01-01

    Reversible, colorimetric fiber-optic sensors are undergoing development for use in measuring concentrations of ammonia in air at levels relevant to human health [0 to 50 parts per million (ppm)]. A sensor of this type includes an optical fiber that has been modified by replacing a portion of its cladding with a polymer coat that contains a dye that reacts reversibly with ammonia and changes color when it does so. The change in color is measured as a change in the amount of light transmitted from one end of the fiber to the other. Responses are reversible and proportional to the concentration of ammonia over the range from 9 to 175 ppm and in some cases the range of reversibility extends up to 270 ppm. The characteristic time for the response of a sensor to rise from 10 to 90 percent of full scale is about 25 seconds. These sensors are fully operational in pure carbon dioxide and are not adversely affected by humidity. This work was done by Michael T. Carter

  15. Thermodynamic Properties of Aqueous Solution of Ammonia

    NASA Astrophysics Data System (ADS)

    Kitamura, Hiroshi; Oguchi, Kosei

    Present status on the thermodynamic properties of experimental data and their correlations of both ammonia and aqueous solution of ammonia was introduced in this paper. The aqueous solution of ammonia is used for not only a working fluid in absorption refrigerator cycles but also working fluids in bottoming cycles of steam power plants and other heat recovering systems. Therefore, the thermodynamic properties of this substance are required in a wide range of temperatures, pressures and compositions. The experimental results of pVTx properties for ammonia and aqueous solution of ammonia and their comparisons with a formulation by Tillner-Roth and Friend1) were critically surveyed. The “Guideline on the IAPWS Formulation 2000 for the Thermodynamic Properties of Ammonia-Water Mixtures”, correlated by Tillner-Roth and Friend1), was approved on September, 2001, by the International Association for the Properties of Water and Steam (IAPWS) 2).

  16. Analysis of Ammonia Toxicity in Landfill Leachates

    PubMed Central

    Osada, Takuya; Nemoto, Keisuke; Nakanishi, Hiroki; Hatano, Ayumi; Shoji, Ryo; Naruoka, Tomohiro; Yamada, Masato

    2011-01-01

    Toxicity identification evaluation (TIE) phase I manipulations and toxicity test with D. magna were conducted on leachates from an industrial waste landfill site in Japan. Physicochemical analysis detected heavy metals at concentrations insufficient to account for the observed acute toxicity. The graduated pH and aeration manipulations identified the prominent toxicity of ammonia. Based on joint toxicity with additive effects of unionized ammonia and ammonium ions, the unionized ammonia toxicity (LC50,NH3(aq)) was calculated as 3.3?ppm, and the toxicity of ammonium ions (LC50,NH4+) was calculated as 222?ppm. Then, the contribution of ammonia toxicity in the landfill leachate toxicity was calculated as 58.7?vol% of the total toxicity in the landfill leachate. Other specific toxicants masked by ammonia's toxicity were detected. Contribution rate of the toxicants other than by ammonia was 41.3?vol% of the total toxicity of the landfill leachate. PMID:23724289

  17. Analysis of ammonia toxicity in landfill leachates.

    PubMed

    Osada, Takuya; Nemoto, Keisuke; Nakanishi, Hiroki; Hatano, Ayumi; Shoji, Ryo; Naruoka, Tomohiro; Yamada, Masato

    2011-01-01

    Toxicity identification evaluation (TIE) phase I manipulations and toxicity test with D. magna were conducted on leachates from an industrial waste landfill site in Japan. Physicochemical analysis detected heavy metals at concentrations insufficient to account for the observed acute toxicity. The graduated pH and aeration manipulations identified the prominent toxicity of ammonia. Based on joint toxicity with additive effects of unionized ammonia and ammonium ions, the unionized ammonia toxicity (LC50,NH3(aq)) was calculated as 3.3?ppm, and the toxicity of ammonium ions (LC50,NH4 (+) ) was calculated as 222?ppm. Then, the contribution of ammonia toxicity in the landfill leachate toxicity was calculated as 58.7?vol% of the total toxicity in the landfill leachate. Other specific toxicants masked by ammonia's toxicity were detected. Contribution rate of the toxicants other than by ammonia was 41.3?vol% of the total toxicity of the landfill leachate. PMID:23724289

  18. Recycling prosodic boundaries.

    PubMed

    Hirose, Yuki

    2003-03-01

    The present study investigates the role of prosodic structure in selecting a syntactic analysis at different stages of parsing in silent reading of Japanese relative clauses. Experiments 1 and 2 (sentence-completion questionnaires) revealed an effect of the length of the sentence-initial constituent on the resolution of a clause boundary ambiguity in Japanese. Experiment 3 (fragment-reading) showed that this length manipulation is also reflected in prosodic phrasing in speech. Its influence on ambiguity resolution is attributed to "recycling" of prosodic boundaries established during the first-pass parse. This explanation is based on the implicit prosody proposals of Bader (1998) and Fodor (1998). Experiment 4 (self-paced reading) demonstrated the immediacy of the influence on ambiguity resolution on-line. Experiment 5 (self-paced reading) found support for the additional prediction that when no boundary is available to be recycled, processing the relative clause construction is more difficult. PMID:12690830

  19. The ammonia freeze explosion (AFEX) process

    Microsoft Academic Search

    Mark T. Holtzapple; Jae-Hoon Jun; Ganesh Ashok; Srinivas L. Patibandla; Bruce E. Dale

    1991-01-01

    The Ammonia Freeze Explosion (AFEX) process treats lignocellulose with high-pressure liquid ammonia, and then explosively\\u000a releases the pressure. The combined chemical effect (cellulose decrystallization) and physical effect (increased accessible\\u000a surface area) dramatically increase lignocellulose susceptibility to enzymatic attack. There are many adjustable parameters\\u000a in the AFEX process: ammonia loading, water loading, temperature, time, blowdown pressure, and number of treatments. The

  20. Composting to Recycle Biowaste

    Microsoft Academic Search

    György Füleky; Szilveszter Benedek

    \\u000a If agriculture is to be made sustainable, few activities like composting are very important. Composting not only allows organic\\u000a waste of agricultural origin to be recycled and returned to the soil, but also provides a solution for managing much of the\\u000a waste, which is currently a major problem. If urban organic waste is selectively collected and composted, it no longer

  1. COPPER CABLE RECYCLING TECHNOLOGY

    SciTech Connect

    Chelsea Hubbard

    2001-05-01

    The United States Department of Energy (DOE) continually seeks safer and more cost-effective technologies for use in deactivation and decommissioning (D&D) of nuclear facilities. The Deactivation and Decommissioning Focus Area (DDFA) of the DOE's Office of Science and Technology (OST) sponsors large-scale demonstration and deployment projects (LSDDPs). At these LSDDPs, developers and vendors of improved or innovative technologies showcase products that are potentially beneficial to the DOE's projects and to others in the D&D community. Benefits sought include decreased health and safety risks to personnel and the environment, increased productivity, and decreased costs of operation. The Idaho National Engineering and Environmental Laboratory (INEEL) generated a list of statements defining specific needs and problems where improved technology could be incorporated into ongoing D&D tasks. One such need is to reduce the volume of waste copper wire and cable generated by D&D. Deactivation and decommissioning activities of nuclear facilities generates hundreds of tons of contaminated copper cable, which are sent to radioactive waste disposal sites. The Copper Cable Recycling Technology separates the clean copper from contaminated insulation and dust materials in these cables. The recovered copper can then be reclaimed and, more importantly, landfill disposal volumes can be reduced. The existing baseline technology for disposing radioactively contaminated cables is to package the cables in wooden storage boxes and dispose of the cables in radioactive waste disposal sites. The Copper Cable Recycling Technology is applicable to facility decommissioning projects at many Department of Energy (DOE) nuclear facilities and commercial nuclear power plants undergoing decommissioning activities. The INEEL Copper Cable Recycling Technology Demonstration investigated the effectiveness and efficiency to recycle 13.5 tons of copper cable. To determine the effectiveness of separating out radioactive contamination, the copper cable was coated with a surrogate contaminant. The demonstration took place at the Bonneville County Technology Center in Idaho Falls, Idaho.

  2. Recycling of pavement materials 

    E-print Network

    O'Neal, Randy Jim

    1976-01-01

    as test projects. Samples of loose mix were obtained for Hveem and Marshall stabilities, direct tension, splitting tensile, and. Schmidt tests. Four inch diameter cores were obtained after compaction and. service. Samples were cut from the cores... for testing of Hveem and Marshall stabilities, splitting tensile, and Schmidt tests. Data was compi. led and analyzed. Test results were inputed into the layered elastic design program in order to determine the structural adequacy of the recycled...

  3. Limited universality at the percolation threshold in 2 to 6 dimensions

    Microsoft Academic Search

    Uwe Gropengiesser; Dietrich Stauffer

    1994-01-01

    The universality of the spanning fraction R(p) of percolation is confirmed by comparing bond percolation with site-bond percolation in four to six dimensions. However, different boundary conditions change the universality class, as shown also for site percolation in two dimensions.

  4. Limited universality at the percolation threshold in 2 to 6 dimensions

    NASA Astrophysics Data System (ADS)

    Gropengiesser, Uwe; Stauffer, Dietrich

    1994-10-01

    The universality of the spanning fraction R( p) of percolation is confirmed by comparing bond percolation with site-bond percolation in four to six dimensions. However, different boundary conditions change the universality class, as shown also for site percolation in two dimensions.

  5. Waste hydrocarbons recycling

    SciTech Connect

    Brinkman, D.W.

    1986-03-01

    During the 1970s, the U.S. supply of petroleum was predicted to be quickly vanishing. The price we would have to pay for what remained would be unprecedented. All alternatives would not only have to be explored, but exploited to their fullest potential. In that decade of recycling aluminum cans, glass bottles, and newspapers by the truckloads, the recycling of petroleum products that had become contaminated, oxidized, or otherwise made unsuitable for their intended use seemed so obvious as to be trivial. Indeed, the level of interest in recycling petroleum products in the 70s was reflected on the quantity of research performed, papers published and patents granted. More than 1,200 reports, patents, and other technical publications were recently documented for this rather narrow subject. And the potential would seem to justify this level of interest. A table shows some of the major waste of used petroleum streams available in the United States alone. Many of these streams represent highly refined products into which we have already invested considerable time and energy. Can these products be recovered for a relatively low additional investment in time and energy. Examples addressing the two largest categories - used lubricating oil and contaminated fuels - are discussed here.

  6. Oriented Percolation in One–dimensional 1\\/| x ? y | 2 Percolation Models

    Microsoft Academic Search

    D. H. U. Marchetti; V. Sidoravicius; M. E. Vares

    2010-01-01

    We consider independent edge percolation models on ?, with edge occupation probabilities \\u000a \\u000a \\u000a \\u000a \\u000a $$p_{\\\\{x,y\\\\}}=\\\\left\\\\{\\\\begin{array}{l@{\\\\quad}l}p&\\\\mathrm{if}\\\\ \\\\vert x-y\\\\vert =1,\\\\\\\\1-\\\\exp \\\\{-\\\\beta \\/\\\\left\\\\vert x-y\\\\right\\\\vert ^{2}\\\\}&\\\\mathrm{otherwise.}\\\\end{array}\\\\right.$$\\u000a \\u000a \\u000a \\u000a We prove that oriented percolation occurs when ?>1 provided p is chosen sufficiently close to 1, answering a question posed in Newman and Schulman (Commun. Math. Phys. 104:547, 1986). The proof is based on multi-scale analysis.

  7. Ammonia drives dendritic cells into dysfunction.

    PubMed

    Luo, Can; Shen, Guobo; Liu, Ning; Gong, Fengming; Wei, Xiawei; Yao, Shaohua; Liu, Dan; Teng, Xiu; Ye, Ning; Zhang, Nan; Zhou, Xikun; Li, Jiong; Yang, Li; Zhao, Xia; Yang, Li; Xiang, Rong; Wei, Yu-Quan

    2014-08-01

    Ammonia levels are often elevated in patients with cirrhosis or tumors. Patients with these diseases are immunocompromised. In this study, we investigated the effects of ammonia on a member of the immune cell family, the dendritic cells (DCs). Our results demonstrated that ammonia diminished cell count, phagocytosis, and lymphocyte stimulation of DCs. Ammonia also induced DC swelling, excessive reactive oxygen species production, and mitochondrial damage, which may constitute the underlying mechanism of ammonia-induced DC dysfunction. In ammonium chloride (NH4Cl)-loaded mice, DCs exhibited lowered phagocytosis and a weakened immune response to the chicken OVA vaccine. DCs from patients with cirrhosis or ammonia-treated healthy human blood both exhibited diminished phagocytosis. Moreover, tumor cell conditioned medium drove DCs into dysfunction, which could be reversed by ammonia elimination. In a murine colon carcinoma model, we found that ammonia could regulate tumor growth involving DCs and their related immune response. These findings reveal that ammonia could drive DCs into dysfunction, which contributes to the immunocompromised state of patients with cirrhosis or tumors. PMID:24965775

  8. Multiple percolation tunneling staircase in metal-semiconductor nanoparticle composites

    SciTech Connect

    Mukherjee, Rupam; Huang, Zhi-Feng; Nadgorny, Boris [Department of Physics and Astronomy, Wayne State University, Detroit, Michigan 48201 (United States)

    2014-10-27

    Multiple percolation transitions are observed in a binary system of RuO{sub 2}-CaCu{sub 3}Ti{sub 4}O{sub 12} metal-semiconductor nanoparticle composites near percolation thresholds. Apart from a classical percolation transition, associated with the appearance of a continuous conductance path through RuO{sub 2} metal oxide nanoparticles, at least two additional tunneling percolation transitions are detected in this composite system. Such behavior is consistent with the recently emerged picture of a quantum conductivity staircase, which predicts several percolation tunneling thresholds in a system with a hierarchy of local tunneling conductance, due to various degrees of proximity of adjacent conducting particles distributed in an insulating matrix. Here, we investigate a different type of percolation tunneling staircase, associated with a more complex conductive and insulating particle microstructure of two types of non-spherical constituents. As tunneling is strongly temperature dependent, we use variable temperature measurements to emphasize the hierarchical nature of consecutive tunneling transitions. The critical exponents corresponding to specific tunneling percolation thresholds are found to be nonuniversal and temperature dependent.

  9. Multiple percolation tunneling staircase in metal-semiconductor nanoparticle composites

    NASA Astrophysics Data System (ADS)

    Mukherjee, Rupam; Huang, Zhi-Feng; Nadgorny, Boris

    2014-10-01

    Multiple percolation transitions are observed in a binary system of RuO2-CaCu3Ti4O12 metal-semiconductor nanoparticle composites near percolation thresholds. Apart from a classical percolation transition, associated with the appearance of a continuous conductance path through RuO2 metal oxide nanoparticles, at least two additional tunneling percolation transitions are detected in this composite system. Such behavior is consistent with the recently emerged picture of a quantum conductivity staircase, which predicts several percolation tunneling thresholds in a system with a hierarchy of local tunneling conductance, due to various degrees of proximity of adjacent conducting particles distributed in an insulating matrix. Here, we investigate a different type of percolation tunneling staircase, associated with a more complex conductive and insulating particle microstructure of two types of non-spherical constituents. As tunneling is strongly temperature dependent, we use variable temperature measurements to emphasize the hierarchical nature of consecutive tunneling transitions. The critical exponents corresponding to specific tunneling percolation thresholds are found to be nonuniversal and temperature dependent.

  10. Ammonia and ammonium hydroxide sensors for ammonia\\/water absorption machines: Literature review and data compilation

    Microsoft Academic Search

    N. C. Anheier Jr.; C. E. McDonald; J. M. Cuta; F. M. Cuta; K. B. Olsen

    1995-01-01

    This report describes an evaluation of various sensing techniques for determining the ammonia concentration in the working fluid of ammonia\\/water absorption cycle systems. The purpose was to determine if any existing sensor technology or instrumentation could provide an accurate, reliable, and cost-effective continuous measure of ammonia concentration in water. The resulting information will be used for design optimization and cycle

  11. Why recycle? A comparison of recycling motivations in four communities

    Microsoft Academic Search

    Joanne Vining; Nancy Linn; Rabel J. Burdge

    1992-01-01

    Four Illinois communities with different sociode-mographic compositions and at various stages of planning for solid waste\\u000a management were surveyed to determine the influence of sociodemographic variables and planning stages on the factors that\\u000a motivate recycling behavior. A factor analysis of importance ratings of reasons for recycling and for not recycling yielded\\u000a five factors interpreted as altruism, personal inconvenience, social influences,

  12. Effect of recycled coarse aggregate on damage of recycled concrete

    Microsoft Academic Search

    Belén González-Fonteboa; Fernando Martínez-Abella; Javier Eiras-López; Sindy Seara-Paz

    This study evaluates the possibility of measuring the damage of the recycled concrete. In this way, two conventional concretes\\u000a with a w\\/c ratio of 0.55 and 0.65 were designed. Based on them, six recycled concretes with different percentages of replacement\\u000a of natural coarse aggregates with recycled coarse aggregate (20, 50 and 100%) were obtained. To take into account the high

  13. Why recycle? A comparison of recycling motivations in four communities

    NASA Astrophysics Data System (ADS)

    Vining, Joanne; Linn, Nancy; Burdge, Rabel J.

    1992-11-01

    Four Illinois communities with different sociode-mographic compositions and at various stages of planning for solid waste management were surveyed to determine the influence of sociodemographic variables and planning stages on the factors that motivate recycling behavior. A factor analysis of importance ratings of reasons for recycling and for not recycling yielded five factors interpreted as altruism, personal inconvenience, social influences, economic incentives, and household storage. The four communities were shown to be significantly different in multivariate analyses of the five motivational factors. However, attempts to explain these community differences with regression analyses, which predicted the motivational factors with dummy codes for planning stages, a measure of self-reported recycling behavior, and sociodemographic measures were unsatisfactory. Contrary to expectation, the solid waste management planning stages of the cities (curbside pickup, recycling dropoff center, and planning in progress) contributed only very slightly to the prediction of motivational factors for recycling. Community differences were better explained by different underlying motivational structures among the four communities. Altruistic reasons for recycling (e.g., conserving resources) composed the only factor which was similar across the four communities. This factor was also perceived to be the most important reason for recycling by respondents from all four communities. The results of the study supported the notion that convenient, voluntary recycling programs that rely on environmental concern and conscience for motivation are useful approaches to reducing waste.

  14. Percolation and magnetization for generalized continuous spin models

    NASA Astrophysics Data System (ADS)

    Fortunato, Santo; Satz, Helmut

    2001-03-01

    For the Ising model, the spin magnetization transition is equivalent to the percolation transition of Fortuin-Kasteleyn clusters; this result remains valid also for the conventional continuous spin Ising model. The investigation of more general continuous spin models may help to obtain a percolation formulation for the critical behaviour in SU(2) gauge theory. We therefore study a broad class of theories, introducing spin distribution functions, longer range interactions and self-interaction terms. The thermal behaviour of each model turns out to be in the Ising universality class. The corresponding percolation formulations are then obtained by extending the Fortuin-Kasteleyn cluster definition; in several cases they illustrate recent rigorous results.

  15. AMMONIA LARGE SCALE ATMOSPHERIC DISPERSION EXPERIMENTS IN INDUSTRIAL CONFIGURATIONS

    E-print Network

    Paris-Sud XI, Université de

    AMMONIA LARGE SCALE ATMOSPHERIC DISPERSION EXPERIMENTS IN INDUSTRIAL CONFIGURATIONS Rémy BOUET atmospheric dispersion ; large-scale experiments ; ammonia ; modelling Abstract A programme of large to April 1997. The objectives of the test campaign were to measure anhydrous ammonia concentrations

  16. Percolation of localized attack on complex networks

    E-print Network

    Shao, Shuai; Stanley, H Eugene; Havlin, Shlomo

    2014-01-01

    The robustness of complex networks against node failure and malicious attack has been of interest for decades, while most of the research has focused on random attack or hub-targeted attack. In many real-world scenarios, however, attacks are neither random nor hub-targeted, but localized, where a group of neighboring nodes in a network are attacked and fail. In this paper we develop a percolation framework to analytically and numerically study the robustness of complex networks against such localized attack. In particular, we investigate this robustness in Erd\\H{o}s-R\\'{e}nyi networks, random-regular networks, and scale-free networks. Our results provide insight into how to better protect networks, enhance cybersecurity, and facilitate the design of more robust infrastructures.

  17. Percolation of localized attack on complex networks

    NASA Astrophysics Data System (ADS)

    Shao, Shuai; Huang, Xuqing; Stanley, H. Eugene; Havlin, Shlomo

    2015-02-01

    The robustness of complex networks against node failure and malicious attack has been of interest for decades, while most of the research has focused on random attack or hub-targeted attack. In many real-world scenarios, however, attacks are neither random nor hub-targeted, but localized, where a group of neighboring nodes in a network are attacked and fail. In this paper we develop a percolation framework to analytically and numerically study the robustness of complex networks against such localized attack. In particular, we investigate this robustness in Erd?s–Rényi networks, random-regular networks, and scale-free networks. Our results provide insight into how to better protect networks, enhance cybersecurity, and facilitate the design of more robust infrastructures.

  18. Study of an ammonia-based wet scrubbing process in a continuous flow system

    SciTech Connect

    Mao, James X.; Lee, Anita S.; Kitchin, John R.; Nulwala, Hunaid B.; Luebke, David R.; Damodaran, Krishnan

    2013-01-01

    A continuous gas and liquid flow, regenerative scrubbing process for CO{sub 2} capture was demonstrated at the bench-scale level. An aqueous ammonia-based solution captures CO{sub 2} from simulated flue gas in an absorber and releases a nearly pure stream of CO{sub 2} in the regenerator. After the regeneration, the solution of ammonium compounds is recycled to the absorber. The design of a continuous flow unit was based on earlier exploratory results from a semi-batch reactor, where a CO{sub 2} and N{sub 2} simulated flue gas mixture flowed through a well-mixed batch of ammonia-based solution. During the semi-batch tests, the solution was cycled between absorption and regeneration steps to measure the carrying capacity of the solution at various initial ammonia concentrations and temperatures. Consequentially, a series of tests were conducted on the continuous unit to observe the effect of various parameters on CO{sub 2} removal efficiency and regenerator effectiveness within the flow system. The parameters that were studied included absorber temperature, regenerator temperature, initial NH{sub 3} concentration, simulated flue gas flow rate, liquid solvent inventory in the flow system, and height of the packed-bed absorber. From this testing and subsequent testing, ammonia losses from both the absorption and regeneration steps were quantified, and attempts were made to maintain steady state during operations. Implications of experimental results with respect to process design are discussed.

  19. MOTIVATIONS AND BEHAVIORS THAT SUPPORT RECYCLING

    Microsoft Academic Search

    Carol M. Werner; Eeva Makela

    1998-01-01

    This paper proposes that recycling researchers should pay attention to both attitudes towards recycling and the processes involved in recycling (recyclers' phenomenal experiences and organizing strategies). As predicted by Sansone and colleagues' model of how people induce themselves to engage in necessary but boring tasks, people who had reasons to persist at recycling (that is, who held strong prorecycling attitudes

  20. Recycling Bin Guide Locations and prices

    E-print Network

    Kirschner, Denise

    Recycling Bin Guide Locations and prices Metal Bins Deskside Bins with Side Saddle Rubbermaid Bins.58 for auxiliaries. And Non-Public Areas Public Offices Non-Public Recyclables Recyclables RecyclablesTrash Trash Trash #12;New Recycling Bin Guidelines Frequently Asked Questions (as of December 2008) · Why

  1. Recycling Best Practices Report August 2011

    E-print Network

    Kirschner, Denise

    Recycling Best Practices Report August 2011 Elizabeth Fox, Recycling Best Practices Intern Office of Waste Reduction and Recycling University of Michigan Plant Building and Grounds Services #12;Recycling Best Practices Report Office of Waste Reduction and Recycling 1 Executive Summary Due to the high

  2. Zero Waste Program 2011 Recycling Benefits

    E-print Network

    Delgado, Mauricio

    Rutgers Zero Waste Program 2011 Recycling Benefits Through WM's Recycling Program, our company saved energy and reduced Greenhouse Gases through recycling. Recycling uses less energy, preserves from recycled material than from virgin, raw material. RESOURCE SAVINGS 4203 Metric Tons (MTCO2E

  3. Environmental Management Waste and Recycling Policy

    E-print Network

    Haase, Markus

    Environmental Management Waste and Recycling Policy October 2006 The University is committed and promoting recycling and the use of recycled materials. We will actively encourage the recycling of office reduction techniques · Provide facilities for recycling on campus · Give guidance and information to staff

  4. Fabrication of Functional Nanofibrous Ammonia Sensor

    Microsoft Academic Search

    Kalayil Manian Manesh; Anantha Iyengar Gopalan; Kwang-Pill Lee; Padmanabhan Santhosh; Kap-Duk Song; Duk-Dong Lee

    2007-01-01

    A nanofibrous sensor for ammonia gas is fabricated by electrospinning the composite of poly(diphenylamine) (PDPA) with poly(methyl methacrylate) (PMMA) onto the patterned interdigit electrode. The composite electrospun membrane shows interconnected fibrous morphology. Functional groups in PDPA and the high active surface area of the fibrous membrane make the device detect a lower concentration of ammonia with a good reproducibility. The

  5. Oxidative and nitrosative stress in ammonia neurotoxicity.

    PubMed

    Skowro?ska, Marta; Albrecht, Jan

    2013-04-01

    Increased ammonia accumulation in the brain due to liver dysfunction is a major contributor to the pathogenesis of hepatic encephalopathy (HE). Fatal outcome of rapidly progressing (acute) HE is mainly related to cytotoxic brain edema associated with astrocytic swelling. An increase of brain ammonia in experimental animals or treatment of cultured astrocytes with ammonia generates reactive oxygen and nitrogen species in the target tissues, leading to oxidative/nitrosative stress (ONS). In cultured astrocytes, ammonia-induced ONS is invariably associated with the increase of the astrocytic cell volume. Interrelated mechanisms underlying this response include increased nitric oxide (NO) synthesis which is partly coupled to the activation of NMDA receptors and increased generation of reactive oxygen species by NADPH oxidase. ONS and astrocytic swelling are further augmented by excessive synthesis of glutamine (Gln) which impairs mitochondrial function following its accumulation in there and degradation back to ammonia ("the Trojan horse" hypothesis). Ammonia also induces ONS in other cell types of the CNS: neurons, microglia and the brain capillary endothelial cells (BCEC). ONS in microglia contributes to the central inflammatory response, while its metabolic and pathophysiological consequences in the BCEC evolve to the vasogenic brain edema associated with HE. Ammonia-induced ONS results in the oxidation of mRNA and nitration/nitrosylation of proteins which impact intracellular metabolism and potentiate the neurotoxic effects. Simultaneously, ammonia facilitates the antioxidant response of the brain, by activating astrocytic transport and export of glutathione, in this way increasing the availability of precursors of neuronal glutathione synthesis. PMID:23142151

  6. Autotrophic Ammonia Removal Processes: Ecology to Technology

    Microsoft Academic Search

    Samik Bagchi; Rima Biswas; Tapas Nandy

    2012-01-01

    The last decade has witnessed rapid spur in technoeconomic autotrophic ammonia removal technologies for wastewater treatment such as SHARON, ANAMMOX, SNAD, CANON, OLAND, DEMON, and BABE. These technologies have the potential to remove high concentrations of ammonia in wastewaters. Despite their high removal efficiency, the quantum of full-scale applications of these processes is far from trivial. The issues that create

  7. Ammonia enhances production from Hungarian field

    Microsoft Academic Search

    A. Ban; V. Balint; F. Pach

    1977-01-01

    The suitability of ammonia to increase ultimate recovery in the Nagylengyel oil field is being tested. Field tests began in late 1973. Ammonium hydroxide was injected into 2 wells, and then the wells were returned to production. Encouraging results led, in early 1975, to an ammonia flood experiment. The Nagylengyel (NL) oil has high molecular weight components either of acid

  8. CHRONIC TOXICITY OF AMMONIA OF RAINBOW TROUT

    EPA Science Inventory

    The chronic effects of ammonia to rainbow trout Salmo gairdneri were studied in a laboratory test conducted over a 5-year period. Fish were tested at five concentrations over the range 0.01-0.07 mg/liter un-ionized ammonia; the mean pH of the test water was 7.7, and the mean temp...

  9. Preparation of Germanium Oxynitride Films in Ammonia

    Microsoft Academic Search

    I. G. Nakhutsrishvili; D. A. Dzhishiashvili; Z. I. Mkervalishvili

    2003-01-01

    The surface reaction of single-crystal germanium with ammonia was studied by microgravimetry. The results indicate that the forming germanium nitride vaporizes and then deposits in the form of germanium oxynitride on a substrate located in the cold zone of the reactor. The formation of the oxynitride film is due to the presence of small amounts of water vapor in ammonia.

  10. Method for releasing hydrogen from ammonia borane

    DOEpatents

    Varma, Arvind; Diwan, Moiz; Shafirovich, Evgeny; Hwang, Hyun-Tae; Al-Kukhun, Ahmad

    2013-02-19

    A method of releasing hydrogen from ammonia borane is disclosed. The method comprises heating an aqueous ammonia borane solution to between about 80-135.degree. C. at between about 14.7 and 200 pounds per square inch absolute (psia) to release hydrogen by hydrothermolysis.

  11. Inactivation of Cryptosporidium parvum Oocysts by Ammonia

    Microsoft Academic Search

    MICHAEL B. JENKINS; DWIGHT D. BOWMAN; WILLIAM C. GHIORSE

    1998-01-01

    The survival of Cryptosporidium parvum oocysts in soil and water microhabitats may be affected by the en- vironmental production and release of free ammonia. The objective of this study was to determine the effects of increasing free ammonia concentrations and times of exposure on oocyst viability. Wild-type oocysts were obtained from naturally infected calf feces by chemical (continuous-flow) centrifugation and

  12. Poultry litter moisture management to reduce ammonia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ammonia generation in poultry houses results from the natural breakdown of litter (bedding material mixed with deposits of feces, feathers, spilled feed and water). Good management practices can reduce ammonia concentrations in poultry houses. This factsheet relates findings from a recent publicat...

  13. Critical litter moisture maximizes ammonia generation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The natural breakdown of litter (bedding material mixed with deposits of feces, feathers, spilled feed and water) generates ammonia in poultry houses. Good management practices can reduce ammonia concentrations in poultry houses. Findings from a recent publication indicate there is a critical litt...

  14. Closed Loop Recycling of PreservativeClosed Loop Recycling of Preservative Treated WoodTreated Wood

    E-print Network

    Closed Loop Recycling of PreservativeClosed Loop Recycling of Preservative Treated WoodTreated WoodDisposal problem Recycling potentialRecycling potential ValueValue--added productsadded products Closed loop recyclingClosed loop recycling #12;Major Current Disposal OptionsMajor Current Disposal Options Incineration

  15. Emulsified industrial oils recycling

    SciTech Connect

    Gabris, T.

    1982-04-01

    The industrial lubricant market has been analyzed with emphasis on current and/or developing recycling and re-refining technologies. This task has been performed for the United States and other industrialized countries, specifically France, West Germany, Italy and Japan. Attention has been focused at emulsion-type fluids regardless of the industrial application involved. It was found that emulsion-type fluids in the United States represent a much higher percentage of the total fluids used than in other industrialized countries. While recycling is an active matter explored by the industry, re-refining is rather a result of other issues than the mere fact that oil can be regenerated from a used industrial emulsion. To extend the longevity of an emulsion is a logical step to keep expenses down by using the emulsion as long as possible. There is, however, another important factor influencing this issue: regulations governing the disposal of such fluids. The ecological question, the respect for nature and the natural balances, is often seen now as everybody's task. Regulations forbid dumping used emulsions in the environment without prior treatment of the water phase and separation of the oil phase. This is a costly procedure, so recycling is attractive since it postpones the problem. It is questionable whether re-refining of these emulsions - as a business - could stand on its own if these emulsions did not have to be taken apart for disposal purposes. Once the emulsion is separated into a water and an oil phase, however, re-refining of the oil does become economical.

  16. Percolation in Transparent and Conducting Carbon Nanotube Networks

    E-print Network

    Gruner, George

    * Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California, 90095/area) changes from a rare, sub-monolayer network, to a thick film. This falls under the marquee of percolation

  17. Recycling parental sexual messages.

    PubMed

    Darling, C A; Hicks, M W

    1983-01-01

    The purpose of this study was to explore parent-child sexual communication by investigating the impact of direct and indirect parental messages on the sexual attitudes and sexual satisfaction of young adults. A survey research design was used to obtain data from undergraduate students attending a large Southern university. The findings indicate that both direct and indirect parental sexual messages are negative and restrictive and have a differential impact on sexual satisfaction and sexual attitudes. While sexual satisfaction was positive, sexual attitudes were found to be problematic, especially among females. Suggestions are given for approaches that family life educators and parents may use in order to recycle previous sexual messages. PMID:6631981

  18. Porosity of recycled concrete with substitution of recycled concrete aggregate

    Microsoft Academic Search

    José M. V Gómez-Soberón

    2002-01-01

    In this paper, we present the experimental analysis of samples of recycled concrete (RC) with replacement of natural aggregate (NA) by recycled aggregate originating from concrete (RCA). The results of the tests of mechanical properties of RC were used for comparison with tests of mercury intrusion porosimetry (MIP), in which the distribution of the theoretical pore radius, critical pore ratio,

  19. Dynamics of Ammonia Borane Using Neutron Scattering

    SciTech Connect

    Brown, Craig; Jacques, Teresa; Hess, Nancy J.; Daemen, Luke L.; Mamontov, Eugene; Linehan, John C.; Stowe, Ashley C.; Autrey, Thomas

    2006-11-15

    We have used both the backscattering (HFBS) and time-of-flight (DCS) neutron spectrometers to investigate the proton dynamics in ammonia borane, a compound of intense interest as a model for 'chemical hydrogen storage' materials. Results indicate that the deposition of ammonia borane on a mesoporous silicate results in longer proton residence times and lower energy barriers for proton motion compared to bulk ammonia borane. The reduced activation energy for proton motions may partly explain the improved thermolysis and lowering the activation barrier for the loss of the first equivalent of H2. In addition, the phonon density of states for neat ammonia borane compares well with other spectroscopic results, with the intense peak at 22 meV assigned to the librational NH3 and BH3 modes, whereas ammonia borane on MCM-41 displays a broad, featureless spectrum indicating a poorly crystalline material.

  20. Percolation model for nodal domains of chaotic wave functions

    E-print Network

    E. Bogomolny; C. Schmit

    2001-10-09

    Nodal domains are regions where a function has definite sign. In recent paper [nlin.CD/0109029] it is conjectured that the distribution of nodal domains for quantum eigenfunctions of chaotic systems is universal. We propose a percolation-like model for description of these nodal domains which permits to calculate all interesting quantities analytically, agrees well with numerical simulations, and due to the relation to percolation theory opens the way of deeper understanding of the structure of chaotic wave functions.

  1. Results of interlaboratory comparisons of column percolation tests

    Microsoft Academic Search

    Ute Kalbe; Wolfgang Berger; Franz-Georg Simon; Jürgen Eckardt; Gabriele Christoph

    2007-01-01

    Laboratory leaching tests may be used for source term determination as a basis for risk assessment for soil–groundwater pathway (leachate forecast) on contaminated sites in Germany. Interlaboratory comparisons on the evaluation of the reproducibility of column percolation tests were conducted within the framework of an integrated R+D program using three waste reference materials.The interlaboratory comparisons of column percolation tests showed

  2. Stress-dependent piezoresistivity of tunneling-percolation systems

    Microsoft Academic Search

    Yansong Wang; Ligong Zhang; Yi Fan; Dapeng Jiang; Linan An

    2009-01-01

    We studied the stress-dependent piezoresistive behavior of tunneling-percolation systems. Starting from percolation-like power\\u000a law of resistivity, a model relating piezoresistive stress coefficient to the applied stress has been developed by considering\\u000a the stress-induced changes in the critical exponent and that in the concentration of conducting phases. It is found that the\\u000a coefficient exhibits reverse and logarithmic dependence on the applied

  3. Performance Testing of the Vapor Phase Catalytic Ammonia Removal Engineering Development Unit

    NASA Technical Reports Server (NTRS)

    Flynn, Michael; Tleimat, Maher; Nalette, Tim; Quinn, Gregory

    2005-01-01

    This paper describes the results of performance testing of the Vapor Phase Catalytic Ammonia Removal (VPCAR) technology. The VPCAR technology is currently being developed by NASA as a Mars transit vehicle water recycling system. NASA has recently completed-a grant-to develop a next generation VPCAR system. This grant concluded with the shipment of the final deliverable to NASA on 8/31/03. This paper presents the results of mass, power, volume, and acoustic measurements for the delivered system. Product water purity analysis for a Mars transit mission and a simulated planetary base wastewater ersatz are also provided.

  4. RECYCLING AND GENERAL WASTE MANAGEMENT OPERATIONAL PROCEDURE

    E-print Network

    Harman, Neal.A.

    RECYCLING AND GENERAL WASTE MANAGEMENT OPERATIONAL PROCEDURE Swansea University Estates Services.6.1/1 Recycling & General Waste Management Department: Estates & Facilities Management Site: Swansea University recycling and waste management facilities in Swansea university To ensure that Waste Management Objectives

  5. The Economic Benefits of Recycling in Virginia

    E-print Network

    Lewis, Robert Michael

    The Economic Benefits of Recycling in Virginia Alexander P. Miller Hang T. Nguyen Samantha D, and the recycling contacts from the participating Solid Waste Planning Units discussed in this study. #12;3 Table Determinants of Recycling_______________________________ 12 State Reports

  6. Energy and Environmental Considerations in Recycling

    E-print Network

    Budker, Dmitry

    Energy and Environmental Considerations in Recycling Griffin Hosseinzadeh 11 April 2012 Physics H materials from recyclables · Carbon emissions & water pollution from production of virgin materials vs. recycling · Methane from decomposing materials in landfill · Depletion of natural resources (trees, minerals

  7. Flooding and Recycling Authorizations Konstantin (Kosta) Beznosov

    E-print Network

    Flooding and Recycling Authorizations Konstantin (Kosta) Beznosov Laboratory for Education delivery channels with speculatively pre- computed authorizations and actively recycling them on a just Security Keywords authorization recycling, authorization flooding, access con- trol, authorization, publish

  8. 16 CFR 260.12 - Recyclable claims.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...the waste stream through an established recycling program for reuse or use in manufacturing...deception about the availability of recycling programs and collection sites to consumers. (1) When recycling facilities are available to a...

  9. 76 FR 71861 - America Recycles Day, 2011

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-18

    ...advanced the common good of our Nation by recycling regularly and promoting conservation...growth. Since then, we have bolstered recycling programs through individual action...we must update and expand existing recycling programs and dedicate ourselves to...

  10. RECYCLING: SUPPLY, ECONOMICS, ENVIRONMENT, AND TECHNOLOGY

    E-print Network

    Abubakr, Said

    RECYCLING: SUPPLY, ECONOMICS, ENVIRONMENT, AND TECHNOLOGY Panel Discussion Roundtable Moderator: S, although higher market values for recyclable will certainly stimulate increased interest in collection in recycling and deinking technologies and process design among North American, European, and Pacific Rim

  11. 16 CFR 260.12 - Recyclable claims.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...the waste stream through an established recycling program for reuse or use in manufacturing...deception about the availability of recycling programs and collection sites to consumers. (1) When recycling facilities are available to a...

  12. From Earth to Space: Application of Biological Treatment for the Removal of Ammonia from Water

    NASA Technical Reports Server (NTRS)

    Pickering, Karen; Adam, Niklas; White, Dawn; Ghosh, Amlan; Seidel, Chad

    2014-01-01

    Managing ammonia is often a challenge in both drinking water and wastewater treatment facilities. Ammonia is unregulated in drinking water, but its presence may result in numerous water quality issues in the distribution system such as loss of residual disinfectant, nitrification, and corrosion. Ammonia concentrations need to be managed in wastewater effluent to sustain the health of receiving water bodies. Biological treatment involves the microbiological oxidation of ammonia to nitrate through a two-step process. While nitrification is common in the environment, and nitrifying bacteria can grow rapidly on filtration media, appropriate conditions, such as the presence of dissolved oxygen and required nutrients, need to be established. This presentation will highlight results from two ongoing research programs - one at NASA's Johnson Space Center, and the other at a drinking water facility in California. Both programs are designed to demonstrate nitrification through biological treatment. The objective of NASA's research is to be able to recycle wastewater to potable water for spaceflight missions. To this end, a biological water processor (BWP) has been integrated with a forward osmosis secondary treatment system (FOST). Bacteria mineralize organic carbon to carbon dioxide as well as ammonia-nitrogen present in the wastewater to nitrogen gas, through a combination of nitrification and denitrification. The effluent from the BWP system is low in organic contaminants, but high in total dissolved solids. The FOST system, integrated downstream of the BWP, removes dissolved solids through a combination of concentration-driven forward osmosis and pressure driven reverse osmosis. The integrated system testing planned for this year is expected to produce water that requires only a polishing step to meet potable water requirements for spaceflight. The pilot study in California is being conducted on Golden State Water Company's Yukon wells that have hydrogen sulfide odor, color, total organic carbon, bromide, iron and manganese in addition to ammonia. A treatment evaluation, conducted in 2011, recommended the testing of biological oxidation filtration for the removal of ammonia and production of biologically stable water. An 8-month pilot testing program was conducted to develop and optimize key design and operational variables. Steadystate operational data was collected to demonstrate long-term performance and inform California Department of Public Health permitting of the full-scale process. As ammonia continues to present challenges to water and wastewater systems, innovative strategies such as biological treatment can be applied to successfully manage it. This presentation will discuss application of cutting-age research being conducted by NASA that will bridge existing information gaps, and benefit municipal utilities.

  13. From Earth to Space: Application of Biological Treatment for the Removal of Ammonia from Water

    NASA Technical Reports Server (NTRS)

    Ghosh, Amlan; Seidel, Chad; Adam, Niklas; Pickering, Karen; White, Dawn

    2014-01-01

    Managing ammonia is often a challenge in both drinking water and wastewater treatment facilities. Ammonia is unregulated in drinking water, but its presence may result in numerous water quality issues in the distribution system such as loss of residual disinfectant, nitrification, and corrosion. Ammonia concentrations need to be managed in wastewater effluent to sustain the health of receiving water bodies. Biological treatment involves the microbiological oxidation of ammonia to nitrate through a two-step process. While nitrification is common in the environment, and nitrifying bacteria can grow rapidly on filtration media, appropriate conditions, such as the presence of dissolved oxygen and required nutrients, need to be established. This presentation will highlight results from two ongoing research programs - one at NASA's Johnson Space Center, and the other at a drinking water facility in California. Both programs are designed to demonstrate nitrification through biological treatment. The objective of NASA's research is to be able to recycle wastewater to potable water for spaceflight mission. To this end, a biological water processor (BWP) has been integrated with a forward osmosis secondary treatment system (FOST). Bacteria mineralize organic carbon to carbon dioxide as well as ammonia-nitrogen present in the wastewater to nitrogen gas, through a combination of nitrification and denitrification. The effluent from the BWP system is low in organic contaminants, but high in total dissolved solids. The FOST system, integrated downstream of the BWP, removes dissolved solids through a combination of concentration-driven forward osmosis and pressure driven reverse osmosis. The integrated system testing planned for this year is expected to produce water that requires only a polishing step to meet potable water requirements for spaceflight. The pilot study in California is being conducted on Golden State Water Company's Yukon wellsthat have hydrogen sulfide odor, color, total organic carbon, bromide, iron and manganese in addition to ammonia. A treatment evaluation, conducted in 2011, recommended the testing of biological oxidation filtration for the removal of ammonia and production of biologically stable water. A 8-month pilot testing program was conducted to develop and optimize key design and operational variables. Steadystate operational data was collected to demonstrate long-term performance and inform California Department of Public Health permitting of the full-scale process. As ammonia continues to present challenges to water and wastewater systems, innovative strategies such as biological treatment can be applied to successfully manage it. This presentation will discuss application of cutting-age research being conducted by NASA that will bridge existing information gaps, and benefit municipal utilities.

  14. Recycling the news

    SciTech Connect

    Sager, K.A.

    1997-09-01

    With its infamous bureaucracy, legions of news organizations, and the prominence of the federal government, Washington, D.C., and its environs generate literally tons of paper every day. Paper represents almost 40% of the waste stream, according to the US EPA. The agency`s figures show that more than 80 million tpy of paper are generated, and with such a significant portion of this waste capable of being recycled, it is essential that the nation`s capital have enough paper recycling facilities. Capital Fiber (Springfield, VA.), a large-scale intermediate paper processing facility, is an example of one such facility. Its primary material is old newspapers (ONP), and its operations consist of receiving, sorting, and consolidating waste paper for baling and resale. The company is a joint venture between daily newspaper giant the Washington Post (Washington, D.C.), which owns 80%, and the Canusa Corp. (Baltimore), a waste paper brokerage firm, which owns the other 20% of Capitol Fiber. Capital Fiber`s Springfield facility handles nine grades of paper, including pre-consumer and post-consumer ONP, blank news (newspaper trimmings that have not been printed on), old corrugated containers (OCC), sorted white ledger and sorted office waste, and various wrappers, supermixes, and other mixed grades. Within each of these categories are various sub-grades of paper, and the facility also takes old telephone books, computer paper, and flyleaf, the extra tim cut from periodicals. But, not surprisingly, the predominant material is ONP.

  15. The Fernald Waste Recycling Program

    Microsoft Academic Search

    Motl

    1993-01-01

    Recycling is considered a critical component of the waste disposition strategy at the Fernald Plant. It is estimated that 33 million cubic feet of waste will be generated during the Fernald cleanup. Recycling some portion of this waste will not only conserve natural resources and disposal volume but will, even more significantly, support the preservation of existing disposition options such

  16. Management of scrap car recycling

    Microsoft Academic Search

    Ching-Hwa Lee

    1997-01-01

    This report describes the current scrap car management system in Taiwan. In Taiwan, most metal scrap for recycling is imported from foreign countries. Since scrap cars contain 80% metal, they are a significant domestic feed source for metal recycling industries in Taiwan. However, many scrap cars are abandoned on the street by the last owner, causing traffic and environmental problems.

  17. TOMATO CLEANING AND WATER RECYCLE

    EPA Science Inventory

    A full-scale dump tank water recycle system was developed and demonstrated. A false bottom-ejector transport system removed soil from the water. Clarified water was either recycled back to the dump tank or discharged to the sewer. A vacuum belt was developed for dewatering the mu...

  18. The Dynamic Earth: Recycling Naturally!

    ERIC Educational Resources Information Center

    Goldston, M. Jenice; Allison, Elizabeth; Fowler, Lisa; Glaze, Amanda

    2013-01-01

    This article begins with a thought-provoking question: What do you think of when you hear the term "recycle?" Many think about paper, glass, aluminum cans, landfills, and reducing waste by reusing some of these materials. How many of us ever consider the way the systems of Earth dynamically recycle its materials? In the following…

  19. Climate Kids: Recycling Program Educator

    NSDL National Science Digital Library

    Using her countywide program as an example, a recycling educator offers incentives for recycling by providing data on energy savings and explaining how her county in Michigan supports the program. The Climate Kids website is a NASA education resource featuring articles, videos, images and games focused on the science of climate change.

  20. Metallic mercury recycling. Final report

    Microsoft Academic Search

    Beck

    1994-01-01

    Metallic mercury is known to be a hazardous material and is regulated as such. The disposal of mercury, usually by landfill, is expensive and does not remove mercury from the environment. Results from the Metallic Mercury Recycling Project have demonstrated that metallic mercury is a good candidate for reclamation and recycling. Most of the potential contamination of mercury resides in

  1. DWPF Recycle Evaporator Simulant Tests

    Microsoft Academic Search

    2005-01-01

    Testing was performed to determine the feasibility and processing characteristics of an evaporation process to reduce the volume of the recycle stream from the Defense Waste Processing Facility (DWPF). The concentrated recycle would be returned to DWPF while the overhead condensate would be transferred to the Effluent Treatment Plant. Various blends of evaporator feed were tested using simulants developed from

  2. Recycling Solid Waste in Chattanooga

    ERIC Educational Resources Information Center

    Vredeveld, Ruth; Martin, Robin

    1973-01-01

    Students undertook a group project in collaboration with city officials to study garbage types in the community and possibilities of recycling solid wastes. Data collected from various sources revealed that public attitude was favorable for recycling efforts and that it was feasible economically. (PS)

  3. Bacterial cell-wall recycling

    PubMed Central

    Johnson, Jarrod W.; Fisher, Jed F.; Mobashery, Shahriar

    2012-01-01

    Many Gram-negative and Gram-positive bacteria recycle a significant proportion of the peptidoglycan components of their cell walls during their growth and septation. In many—and quite possibly all—bacteria, the peptidoglycan fragments are recovered and recycled. While cell-wall recycling is beneficial for the recovery of resources, it also serves as a mechanism to detect cell-wall–targeting antibiotics and to regulate resistance mechanisms. In several Gram-negative pathogens, anhydro-MurNAc-peptide cell-wall fragments regulate AmpC ?-lactamase induction. In some Gram-positive organisms, short peptides derived from the cell wall regulate the induction of both ?-lactamase and ?-lactam-resistant penicillin-binding proteins. The involvement of peptidoglycan recycling with resistance regulation suggests that inhibitors of the enzymes involved in the recycling might synergize with cell-wall-targeted antibiotics. Indeed, such inhibitors improve the potency of ?-lactams in vitro against inducible AmpC ?-lactamase-producing bacteria. We describe the key steps of cell-wall remodeling and recycling, the regulation of resistance mechanisms by cell-wall recycling, and recent advances toward the discovery of cell-wall recycling inhibitors. PMID:23163477

  4. Seasonal variations of the effect of temperature on lethal and sublethal toxicities of ammonia for three common freshwater shredders.

    PubMed

    Dehedin, Arnaud; Piscart, Christophe; Marmonier, Pierre

    2013-01-01

    In a context of global change, increases in temperature and in ammonia concentration should strongly affect the crustaceans of wetlands. We experimentally examined, at three different seasons (i.e. winter, spring, and summer), the effect of temperature (12, 18, and 24°C) on the lethal (survival rates) and sublethal (oxygen consumption) toxicity of unionized ammonia (NH(3)) on the amphipods Gammarus pulex and Gammarus roeselii and the isopod Asellus aquaticus. Our results demonstrate (1) a gradient of increasing tolerance and survival from G. roeselii to G. pulex and A. aquaticus, (2) an increasing toxicity of ammonia with temperature, and (3) a strong seasonal variation of the tolerance to ammonia, with a higher tolerance of individuals in winter than in summer. However, the sub-lethal effect of ammonia on the oxygen consumption rate was species dependant and changed according to temperature or season. Global change and resulting variations in crustacean densities will potentially affect the ecosystem functioning (e.g. organic matter recycling). PMID:22910696

  5. Measuring ammonia concentration over a grassland near livestock facilities using a semiconductor ammonia sensor

    NASA Astrophysics Data System (ADS)

    Kawashima, S.; Yonemura, S.

    We demonstrated the effectiveness of a semiconductor ammonia sensor capable of performing diachronic measurements; its characteristics were checked in the laboratory by means including comparison with standard gases. We found as a result that the ammonia sensor's readings increased with increasing water vapor pressure. We compared sensor readings with values obtained by chemical analysis of samples collected in situ and checked sensor reading accuracy. Ammonia concentration was determined by combining ammonia sensor readings with measured values for water vapor pressure. In situ conditions were ammonia concentration of under 100 ppbv and water vapor pressure of 4-16 hPa. There was a good correlation with the concentration of samples trapped with boric acid and analyzed by indophenol colorimetry. We discerned a relationship between ammonia concentration and local meteorological conditions such as wind direction and speed. The estimated error of the ammonia sensor's measurements was ±9.7 ppbv when ammonia concentration as measured by acid sampling and colorimetry was regarded as correct. This demonstrated that it is possible to detect in situ fluctuations in low ammonia concentrations of about 10 ppbv, which was the background concentration in farming areas. We have shown a monitoring method for ammonia in situ that is both easy to operate and low-cost.

  6. Resveratrol Prevents Ammonia Toxicity in Astroglial Cells

    PubMed Central

    Guerra, Maria Cristina; Leite, Marina Concli; Souza, Diogo Onofre; Gonçalves, Carlos-Alberto; Gottfried, Carmem

    2012-01-01

    Ammonia is implicated as a neurotoxin in brain metabolic disorders associated with hyperammonemia. Acute ammonia toxicity can be mediated by an excitotoxic mechanism, oxidative stress and nitric oxide (NO) production. Astrocytes interact with neurons, providing metabolic support and protecting against oxidative stress and excitotoxicity. Astrocytes also convert excess ammonia and glutamate into glutamine via glutamine synthetase (GS). Resveratrol, a polyphenol found in grapes and red wines, exhibits antioxidant and anti-inflammatory properties and modulates glial functions, such as glutamate metabolism. We investigated the effect of resveratrol on the production of reactive oxygen species (ROS), GS activity, S100B secretion, TNF-?, IL-1? and IL-6 levels in astroglial cells exposed to ammonia. Ammonia induced oxidative stress, decreased GS activity and increased cytokines release, probably by a mechanism dependent on protein kinase A (PKA) and extracellular signal-regulated kinase (ERK) pathways. Resveratrol prevented ammonia toxicity by modulating oxidative stress, glial and inflammatory responses. The ERK and nuclear factor-?B (NF-?B) are involved in the protective effect of resveratrol on cytokines proinflammatory release. In contrast, other antioxidants (e.g., ascorbic acid and trolox) were not effective against hyperammonemia. Thus, resveratrol could be used to protect against ammonia-induced neurotoxicity. PMID:23284918

  7. Low-cost anodes for ammonia electrooxidation

    NASA Astrophysics Data System (ADS)

    Selverston, Steven M.

    This research focused on the development of low-cost electrodes for the electrochemical oxidation of ammonia to nitrogen, a reaction that has possible applications in hydrogen generation, direct ammonia fuel cells, water treatment, and sensors. Statistical design of experiments was used to help develop an efficient and scalable process for electrodeposition of platinum with a specific electrochemical surface area of over 25 m2 /g. Catalyst surface area and activity were evaluated using cyclic voltammetry, and the material microstructure and morphology were investigated using x-ray diffraction and scanning electron microscopy. The synthesized electrodes were found to be active toward the ammonia electrooxidation reaction, particularly when supporting electrolyte was added. However, supporting electrolyte was not required in order to oxidize the ammonia. As proof of concept, a homemade direct ammonia fuel cell employing a commercial anion exchange membrane was tested at room temperature with gravity-fed fuel and without supporting electrolyte. At room temperature, with passive reactant supply and using dissolved oxygen at the cathode, the cell produced about one quarter the power of a direct methanol fuel cell that used active transport of humidified oxygen and preheated (50 °C) methanol. With continued development of the membrane, cathode and membrane electrode assembly, the passive direct ammonia fuel cell using anion exchange membrane could have performance similar to the equivalent direct methanol fuel cell, and it could benefit from many advantages of ammonia over methanol such as lower cost, higher energy density, and reduced greenhouse gas emissions.

  8. Vapor Phase Catalytic Ammonia Reduction

    NASA Technical Reports Server (NTRS)

    Flynn, Michael T.; Harper, Lynn D. (Technical Monitor)

    1994-01-01

    This paper discusses the development of a Vapor Phase Catalytic Ammonia Reduction (VPCAR) teststand and the results of an experimental program designed to evaluate the potential of the technology as a water purification process. In the experimental program the technology is evaluated based upon product water purity, water recovery rate, and power consumption. The experimental work demonstrates that the technology produces high purity product water and attains high water recovery rates at a relatively high specific power consumption. The experimental program was conducted in 3 phases. In phase I an Igepon(TM) soap and water mixture was used to evaluate the performance of an innovative Wiped-Film Rotating-Disk evaporator and associated demister. In phase II a phenol-water solution was used to evaluate the performance of the high temperature catalytic oxidation reactor. In phase III a urine analog was used to evaluate the performance of the combined distillation/oxidation functions of the processor.

  9. Rab11 regulates recycling through the pericentriolar recycling endosome

    PubMed Central

    1996-01-01

    Small GTPases of the rab family are crucial elements of the machinery that controls membrane traffic. In the present study, we examined the distribution and function of rab11. Rab11 was shown by confocal immunofluorescence microscopy and EM to colocalize with internalized transferrin in the pericentriolar recycling compartment of CHO and BHK cells. Expression of rab11 mutants that are preferentially in the GTP- or GDP-bound state caused opposite effects on the distribution of transferrin-containing elements; rab11-GTP expression caused accumulation of labeled elements in the perinuclear area of the cell, whereas rab11-GDP caused a dispersion of the transferrin labeling. Functional studies showed that the early steps of uptake and recycling for transferrin were not affected by overexpression of rab11 proteins. However, recycling from the later recycling endosome was inhibited in cells overexpressing the rab11-GDP mutant. Rab5, which regulates early endocytic trafficking, acted before rab11 in the transferrin-recycling pathway as expression of rab5-GTP prevented transport to the rab11- positive recycling endosome. These results suggest a novel role for rab11 in controlling traffic through the recycling endosome. PMID:8922376

  10. A percolation model of ecological flows

    SciTech Connect

    Gardner, R.H.; Turner, M.G.; Dale, V.H.; O'Neill, R.V.

    1988-01-01

    The boundary zone between adjacent communities has long been recognized as a functionally important component of ecosystems. The diversity and abundance of species, the flow and accumulation of material and energy, and the propagation of disturbances may all be affected by landscape boundaries. However, the spatial arrangement of different habitats and their boundaries has received little direct study. The difficulty in studying landscape boundaries has been due, in part, to the variety of responses of organisms to ecotones. Therefore, definitive tests of relationships between ecological processes and the pattern of landscape boundaries will be greatly assisted by developing a standard against which comparisons can be made. Neutral models can define this standard by producing the expected'' Poisson distribution have been well established, but a general approach for relating ecological processes and landscape patterns must still be defined. The purpose of this chapter is to illustrate how neutral models that are developed from percolation theory can be used to address the problem How do ecological system boundaries influence biotic diversity and the flow of energy, information and materials '' 26 refs., 4 figs., 1 tab.

  11. Two exactly soluble models of rigidity percolation

    PubMed Central

    Thorpe, M. F.; Stinchcombe, R. B.

    2014-01-01

    We summarize results for two exactly soluble classes of bond-diluted models for rigidity percolation, which can serve as a benchmark for numerical and approximate methods. For bond dilution problems involving rigidity, the number of floppy modes F plays the role of a free energy. Both models involve pathological lattices with two-dimensional vector displacements. The first model involves hierarchical lattices where renormalization group calculations can be used to give exact solutions. Algebraic scaling transformations produce a transition of the second order, with an unstable critical point and associated scaling laws at a mean coordination ?r?=4.41, which is above the ‘mean field’ value ?r?=4 predicted by Maxwell constraint counting. The order parameter exponent associated with the spanning rigid cluster geometry is ?=0.0775 and that associated with the divergence of the correlation length and the anomalous lattice dimension d is d?=3.533. The second model involves Bethe lattices where the rigidity transition is massively first order by a mean coordination ?r?=3.94 slightly below that predicted by Maxwell constraint counting. We show how a Maxwell equal area construction can be used to locate the first-order transition and how this result agrees with simulation results on larger random-bond lattices using the pebble game algorithm. PMID:24379428

  12. Sol-gel-derived percolative copper film

    SciTech Connect

    Szu Sungping [Department of Physics, National Chung-Hsing University, Taichung 402, Taiwan (China)], E-mail: spszu@phys.nchu.edu.tw; Cheng, C.-L. [Department of Physics, National Chung-Hsing University, Taichung 402, Taiwan (China)

    2008-10-02

    Cu-SiO{sub 2} films were prepared by the sol-gel method. Two-dimensional fractal copper films were formed after the films were thermally treated in reducing atmosphere. dc resistances of the films decrease 12 orders of magnitude as the content of copper increases from 70 to 80 mol%. During the resistance measurement under argon atmosphere, samples showed a sharp increase or decrease of resistance at a transition temperature which is ascribed to the oxidation of Cu into CuO. The oxidation was also observed in the in situ high temperature X-ray diffraction under vacuum condition. The evolution of the morphology of the films was studied by scanning electron microscopy. As the content of copper increases, the forms of copper particles change from discrete to aggregate then to interconnecting. The coverage coefficients of the copper range from 23 to 55% and the fractal dimensions range from 1.65 to 1.77. The percolation thresholds for the coverage coefficient and the fractal dimension are about 33% and 1.71, respectively, which corresponds to the sample containing 72.5 mol% of Cu.

  13. The ammonia hydrates—model mixed-hydrogen-bonded systems

    Microsoft Academic Search

    J. S. Loveday; R. J. Nelmes

    2004-01-01

    The three ammonia hydrates (ammonia dihydrate, ADH; ammonia monohydrate, AMH and ammonia hemihydrate, AHH) are amongst the simplest systems to contain mixed nitrogen oxygen–hydrogen bonds. In addition, ADH and AMH are believed to be common in the outer solar system, and their properties are important for modelling bodies such as Uranus, Neptune and Titan. Neutron diffraction studies have provided the

  14. AMMONIA EFFECTS ON MICROINVERTEBRATES AND FISH IN OUTDOOR EXPERIMENTAL STREAMS

    EPA Science Inventory

    Laboratory data on ammonia effects, the US EPA national water quality criteria for ammonia, and ammonia site-specific criteria were evaluated in four outdoor experimental streams (one control and three treatment streams) over a 76-week period. Calculated un-ionized ammonia concen...

  15. USF Physical Plant Recycling Program Updated November 2013

    E-print Network

    Meyers, Steven D.

    USF Physical Plant Recycling Program Updated November 2013 #12;Beginnings · Program initiated · Continuously expanding recycling efforts #12;Paper Recycling · Currently recycling mixed paper Office paper, newspaper, magazines, cardboard, paperbacks · PPD has distributed about 2,400 office-size recycling

  16. Recycle of waste paper

    SciTech Connect

    Hackett, G.D.; Harris, G.E.

    1988-01-01

    One of the Oak Ridge Y-12 Plant's long range goals is to reduce the amount of waste from the plant. The large amount of waste paper generated by the plant is currently buried in the state permitted landfill. Methods of recycling cardboard and paper which comply with all security requirements, health, safety, and environmental regulations of the Y-12 Plant are sought to conserve the landfill. A process to compact paper into a form which may be used as fuel and fed into the existing steam plant has been developed. A water-resistant briquette has been made from waste paper, a binder, and coal. Laboratory and pilot scale briquetting and pulverizing tests have been completed. These briquettes have physical properties similar to those of coal. 12 tabs.

  17. Exploring Waste and Recycling

    NSDL National Science Digital Library

    Camann, Eleanor

    This resource, created by Eleanor Camann of Red Rocks Community College, will introduce students to the concept of sustainability in terms of waste products and recycling practices. The overall premise of the project is to "get students to think critically about which earth materials are used to make things, and where all the waste from both mining and consumption ends up." The activity employs skills in basic mathematics, reasoning and writing. It also crosses disciplines by implementing skills in environmental geology and science. The learning activity only takes about two hours of in-class time and an additional three outside of the classroom. It uses simple materials such as a calculator, periodic table, household scale and digital camera. Lessons plans such as these are supported by a grant under the National Science Foundation's Advanced Technological Education (ATE) program.

  18. Open-loop recycling: A LCA case study of PET bottle-to-fibre recycling

    Microsoft Academic Search

    Li Shen; Ernst Worrell; Martin K. Patel

    2010-01-01

    This study assesses the environmental impact of polyethylene terephthalate (PET) bottle-to-fibre recycling using the methodology of life-cycle assessment (LCA). Four recycling cases, including mechanical recycling, semi-mechanical recycling, back-to-oligomer recycling and back-to-monomer recycling were analysed. Three allocation methods are applied for open-loop recycling, i.e. the “cut-off” approach, the “waste valuation” approach and the “system expansion” approach. Nine environmental impact indicators were

  19. Ammonia volatilization in soil treated with tannery sludge.

    PubMed

    Martines, A M; Nogueira, M A; Santos, C A; Nakatani, A S; Andrade, C A; Coscione, A R; Cantarella, H; Sousa, J P; Cardoso, E J B N

    2010-06-01

    The utilization of tannery sludge in agricultural areas can be an alternative for its disposal and recycling. Despite this procedure may cause the loss of nitrogen by ammonia volatilization, there is no information about this process in tropical soils. For two years a field experiment was carried out in Rolândia (Paraná State, Brazil), to evaluate the amount of NH(3) volatilization due to tannery sludge application on agricultural soil. The doses of total N applied varied from zero to 1200 kg ha(-1), maintained at the surface for 89 days, as usual in this region. The alkalinity of the tannery sludge used was equivalent to between 262 and 361 g CaCO(3) per kg. Michaelis-Menten equation was adequate to estimate NH(3)-N volatilization kinetics. The relation between total nitrogen applied as tannery sludge and the potentially volatilized NH(3)-N, calculated by the chemical-kinetics equation resulted in an average determination coefficient of 0.87 (P>0.01). In this period, the amount of volatilized NH(3) was more intense during the first 30 days; the time to reach half of the maximum NH(3) volatilization (K(m)) was 13 an 9 days for the first and second experiments, respectively. The total loss as ammonia in the whole period corresponded in average to 17.5% of the total N applied and to 35% of the NH(4)(+)-N present in the sludge. If tannery sludge is to be surface applied to supply N for crops, the amounts lost as NH(3) must be taken into consideration. PMID:20171093

  20. Defences against ammonia toxicity in tropical air-breathing fishes exposed to high concentrations of environmental ammonia: a review

    Microsoft Academic Search

    Y. K. Ip; S. F. Chew; J. M. Wilson; D. J. Randall

    2004-01-01

    In the tropics, air-breathing fishes can be exposed to environmental ammonia when stranded in puddles of water during the dry season, during a stay inside a burrow, or after agricultural fertilization. At low concentrations of environmental ammonia, NH 3 excretion is impeded, as in aerial exposure, leading to the accumulation of endogenous ammonia. At high concentrations of environmental ammonia, which

  1. Modeling and simulation of ammonia removal from purge gases of ammonia plants using a catalytic Pd–Ag membrane reactor

    Microsoft Academic Search

    M. R. Rahimpour; A. Asgari

    2008-01-01

    In this work, the removal of ammonia from synthesis purge gas of an ammonia plant has been investigated. Since the ammonia decomposition is thermodynamically limited, a membrane reactor is used for complete decomposition. A double pipe catalytic membrane reactor is used to remove ammonia from purge gas. The purge gas is flowing in the reaction side and is converted to

  2. Ammonia-dimethylchloramine system: kinetic approach in an aqueous medium and comparison with the mechanism involving in liquid ammonia

    E-print Network

    Paris-Sud XI, Université de

    1 Ammonia-dimethylchloramine system: kinetic approach in an aqueous medium and comparison with the mechanism involving in liquid ammonia J. Stephan, V. Pasquet*, M. Elkhatib, V. Goutelle, H. Delalu of the system ammonia-dimethylchloramine in liquid ammonia, it was interesting to compare the reactivity

  3. Ammonia stripping for enhanced biomethanization of piggery wastewater

    Microsoft Academic Search

    Lei Zhang; Yong-Woo Lee; Deokjin Jahng

    In this study, the effects of ammonia removal by air stripping as a pretreatment on the anaerobic digestion of piggery wastewater were investigated. Ammonia stripping results indicated that ammonia removal was strongly dependent on pH and aeration rate, and the ammonia removal rate followed the pseudo-first-order kinetics. A significant enhancement of biomethanization was observed for wastewaters of which ammonia was

  4. Recycling and Life Cycle Issues

    SciTech Connect

    Das, Sujit [ORNL

    2010-01-01

    This chapter addresses recycling and life cycle considerations related to the growing use of lightweight materials in vehicles. The chapter first addresses the benefit of a life cycle perspective in materials choice, and the role that recycling plays in reducing energy inputs and environmental impacts in a vehicle s life cycle. Some limitations of life cycle analysis and results of several vehicle- and fleet-level assessments are drawn from published studies. With emphasis on lightweight materials such as aluminum, magnesium, and polymer composites, the status of the existing recycling infrastructure and technological challenges being faced by the industry also are discussed.

  5. High-pressure studies of ammonia hydrates 

    E-print Network

    Wilson, Craig W.

    2014-06-28

    Ammonia and water are major components of many planetary bodies, from comets and icy moons such as Saturn's Titan to the interiors of the planets Neptune and Uranus. Under a range of high pressures and/or low temperatures known ...

  6. An Experimental Approach to the Percolation of Sticky Nanotubes

    NASA Astrophysics Data System (ADS)

    Vigolo, B.; Coulon, C.; Maugey, M.; Zakri, C.; Poulin, P.

    2005-08-01

    Percolation is a statistical concept that describes the formation of an infinite cluster of connected particles or pathways. Lowering the percolation threshold is a critical issue to achieve light and low-cost conductive composites made of an insulating matrix loaded with conductive particles. This has interest for applications where charge dissipation and electrical conductivity are sought in films, coatings, paints, or composite materials. One route to decreasing the loading required for percolation is to use rod-like particles. Theoretical predictions indicate that this may also be achieved by altering the interaction potential between the particles. Although percolation may not always respond monotonically to interactions, the use of adhesive rods can be expected to be an ideal combination. By using a system made of carbon nanotubes in an aqueous surfactant solution, we find that very small attraction can markedly lower the percolation threshold. The strength of this effect can thereby have direct technological interest and explain the large variability of experimental results in the literature dealing with the electrical behavior of composites loaded with conducting rods.

  7. Viscosity and thermal conductivity of stable graphite suspensions near percolation.

    PubMed

    Ma, Lei; Wang, Jianjian; Marconnet, Amy M; Barbati, Alexander C; McKinley, Gareth H; Liu, Wei; Chen, Gang

    2015-01-14

    Nanofluids have received much attention in part due to the range of properties possible with different combinations of nanoparticles and base fluids. In this work, we measure the viscosity of suspensions of graphite particles in ethylene glycol as a function of the volume fraction, shear rate, and temperature below and above the percolation threshold. We also measure and contrast the trends observed in the viscosity with increasing volume fraction to the thermal conductivity behavior of the same suspensions: above the percolation threshold, the slope that describes the rate of thermal conductivity enhancement with concentration reduces compared to below the percolation threshold, whereas that of the viscosity enhancement increases. While the thermal conductivity enhancement is independent of temperature, the viscosity changes show a strong dependence on temperature and exhibit different trends with respect to the temperature at different shear rates above the percolation threshold. Interpretation of the experimental observations is provided within the framework of Stokesian dynamics simulations of the suspension microstructure and suggests that although diffusive contributions are not important for the observed thermal conductivity enhancement, they are important for understanding the variations in the viscosity with changes of temperature and shear rate above the percolation threshold. The experimental results can be collapsed to a single master curve through calculation of a single dimensionless parameter (a Péclet number based on the rotary diffusivity of the graphite particles). PMID:25469709

  8. Bounds for percolation thresholds on directed and undirected graphs

    NASA Astrophysics Data System (ADS)

    Hamilton, Kathleen; Pryadko, Leonid

    2015-03-01

    Percolation theory is an efficient approach to problems with strong disorder, e.g., in quantum or classical transport, composite materials, and diluted magnets. Recently, the growing role of big data in scientific and industrial applications has led to a renewed interest in graph theory as a tool for describing complex connections in various kinds of networks: social, biological, technological, etc. In particular, percolation on graphs has been used to describe internet stability, spread of contagious diseases and computer viruses; related models describe market crashes and viral spread in social networks. We consider site-dependent percolation on directed and undirected graphs, and present several exact bounds for location of the percolation transition in terms of the eigenvalues of matrices associated with graphs, including the adjacency matrix and the Hashimoto matrix used to enumerate non-backtracking walks. These bounds correspond t0 a mean field approximation and become asymptotically exact for graphs with no short cycles. We illustrate this convergence numerically by simulating percolation on several families of graphs with different cycle lengths. This research was supported in part by the NSF Grant PHY-1416578 and by the ARO Grant W911NF-11-1-0027.

  9. Technical activities 1980 office of recycled materials

    Microsoft Academic Search

    D. A. Becker; J. G. Berke; R. T. Matthews; H. Yakowitz

    1980-01-01

    A review of recycled materials programs at NBS, for FY 1980 is presented in this annual report. This report contains the following: The Office of Recycled Materials - A plan for the future; The NBS recycled oil program--(Introduction, the NBS role in recycled oil, the current NBS program, plan, implementation, and discussion); The resource conservation and recovery program--(Introduction, needs, goal

  10. Recycled Wash Water Crushed Returned Concrete

    E-print Network

    1 Recycled Wash Water Crushed Returned Concrete National Concrete Consortium March 2012 Colin Lobo% increase by 2030 "Waste" to "Recycled" Returned Concrete - estimated 2 - 10% of production 8 to 12 by 2030 Recycled content: 200% increase by 2020 400% increase by 2030 Recycled Content: Where are we

  11. Super recycled water: quenching January 30, 2014

    E-print Network

    purifying" wastewater, plus recycling waste to replace concrete We know water is a precious resource creating recycled material to replace concrete, the most widely used construction material on Earth which- 1 - Super recycled water: quenching computers January 30, 2014 Conserving, recycling and "super

  12. Shear strength of recycled concrete beams

    Microsoft Academic Search

    Belén González-Fonteboa; Fernando Martínez-Abella

    2007-01-01

    This paper reports on the shear behaviour of concrete made with recycled concrete aggregates. Tests have been performed on recycled aggregates and on two concrete mixes (conventional concrete and recycled concrete with 50% of recycled coarse aggregates). For every concrete, four reinforced beams with different amount of transverse reinforcement were made and were tested to failure. The results showed that

  13. Flexural Behavior of Reinforced Recycled Concrete Beams

    Microsoft Academic Search

    Ryoichi Sato; Ippei Maruyama; Takahisa Sogabe; Masaru Sogo

    2007-01-01

    In order to evaluate whether concrete with recycled aggregate can be applied for concrete structures, flexural loading tests of reinforced recycled concrete members were carried out. The recycled coarse aggregate and the recycled fine aggregate were produced mainly from various reinforced concrete members of a building structure as well as from 300 mm cubic concrete specimens. The properties of concrete

  14. EXPLAINING RURAL HOUSEHOLD PARTICIPATION IN RECYCLING

    Microsoft Academic Search

    Paul M. Jakus; Kelly H. Tiller; William M. Park

    1997-01-01

    Rising landfill costs have forced solid waste managers to consider waste stream reduction alternatives such as household recycling. Explaining the factors which motivate households to recycle is important to regions where households must bear a large portion of the recycling cost because unit-based garbage disposal fees and curbside recycling are not feasible options. Empirical results indicate that residents are responsive

  15. RECYCLING PROGRAM TYPE LOCATION ALLOWED NOT ALLOWED

    E-print Network

    Miami, University of

    RECYCLING PROGRAM TYPE LOCATION ALLOWED NOT ALLOWED Batteries, toner, ink cartridges & cell phones and recycling is an important part of that effort. Below is a guide to on-campus recycling at RSMAS: Visit http://www.rsmas.miami.edu/msgso/ for map of recycling bin locations. NOTE: This is not an exhaustive list. If unauthorized items are found

  16. The Environment Team to Waste & Recycling

    E-print Network

    St Andrews, University of

    The Environment Team A-Z Guide to Waste & Recycling www.le.ac.uk/environment #12;Welcome ...to the University of Leicester's `A-Z Guide to Waste and Recycling'. Over the last 3 years, the Environment Team has introduced an award- winning recycling scheme across the campus that allows us to recycle paper, plastics

  17. Ink and Toner Recycling Rewards Program Overview

    E-print Network

    Meyers, Steven D.

    Ink and Toner Recycling Rewards Program Overview www.MyBusinessRecycles.com April 2013 #12;Program Overview · All BSD contract customers can participate in the MyBusinessRecycles program · Customers located in AK, HI or PR are not currently eligible. ­ Education sector customers should join the Recycling Rules

  18. You're a "What"? Recycling Coordinator

    ERIC Educational Resources Information Center

    Torpey, Elka Maria

    2011-01-01

    Recycling coordinators supervise curbside and dropoff recycling programs for municipal governments or private firms. Today, recycling is mandatory in many communities. And advancements in collection and processing methods have helped to increase the quantity of materials for which the recycling coordinator is responsible. In some communities,…

  19. State strategy for recycling market development

    Microsoft Academic Search

    Millberg

    1991-01-01

    The ultimate importance of developing recycling markets is to accomplish these five objectives: Assist local governments and state offices in achieving the recycling goals in the SCORE (Select Committee on Recycling and the Environment) legislation through the development of recycling markets, while focusing on longer-term market development for additional materials in the waste stream that currently are not recovered, or

  20. A RECYCLED LAN DSCAPE Richard H. Durrell

    E-print Network

    Maynard, J. Barry

    A RECYCLED LAN DSCAPE by Richard H. Durrell Department of Geology University of Cincinnati Drafting, May 1977 (R.A. Davis, editor) Reprinted 1982 A recycled landscape "Recycling" is the word of the day the same way, Nature recycles even the very hills and valleys beneath our feet. But, as usual, Nature

  1. WASTE MINIMISATION AND RECYCLING POLICY 1.Introduction

    E-print Network

    Mottram, Nigel

    WASTE MINIMISATION AND RECYCLING POLICY 1.Introduction University of Glasgow has stated its overall as it relates to waste minimisation and recycling. 2.Recycling Policy Statement The University of Glasgow of awareness of waste minimisation and recycling within the University community · Promote economy in the use

  2. Highly sensitive and selective ammonia gas sensor

    Microsoft Academic Search

    Dong Hyun Yun; Chul Han Kwon; Hyung-Ki Hong; Seung-Ryeol Kim; Kyuchung Lee; Ho Geun Song; Ji Eon Kim

    1997-01-01

    We have fabricated and examined an ammonia gas sensor with high sensitivity using thick-film technology. The sensing material of the gas sensor is FeOx-WO3-SnO2 oxide semiconductor. The sensor exhibits resistance increase upon exposure to low concentration of ammonia gas. The resistance of the sensor is decreased, on the other hand, for exposure to reducing gases such as ethyl alcohol, methane,

  3. Ammonia removal from coal dry distillation wastewater

    Microsoft Academic Search

    Guanghua Wang; Fanjie Gong; Wenbing Li; Yunzhou Lu; Mingdong Sun; Tiejun Liu; Yuhe Liang; Xiaoyuan Li; Zengqiang Huang

    2011-01-01

    the article used coke oven gas as desorption agent, pilot-scale packed tower as desorption equipment, removed ammonia from wastewater produced by coal dry distillation process. Gas stripping method is a new technology for ammonia removal. Through experiments conducted in the coking plant, when the temperature of wastewater T=85°C, pH=1l.5, the ratio of liquid and gas volume n=550:1 and the addition

  4. Ammonia-Soluable Inorganic Soil Colloids. 

    E-print Network

    Fraps, G. S.

    1914-01-01

    4 7 2 -5 1 4 -IO m TEXAS AGRICULTURAL EXPERIMENT STATION BULLETIN NO . 165 APRIL , 1914 DIVISION OF CHEMISTRY Ammonia-Soluble Inorganic Soil Colloids POSTOFFICE College Station, Brazos County, Texas YON BOECKMANN-JONES CO., PRINTERS..., United States Department of Agriculture. tResigned April 1, 1914. AMMONIA-SOLUBLE INORGANIC SOIL COLLOIDS G. S. F r a p s , P H . D., Chemist. The colloidal constituents of tile soil are considered as of consider? able importance. Van Bemmerlen1 has...

  5. Supercritical ammonia pretreatment of lignocellulosic materials

    Microsoft Academic Search

    Y. C. T. Chou; C. D. Scott

    1986-01-01

    A pretreatment technique using ammonia in a supercritical or near-critical fluid state was shown to substantially enhance the susceptibility of polysaccharides in lignocellulosics to subsequent hydrolysis by Trichoderma reesei cellulase. Near-theoretical conversion of cellulose and 70-80% conversion of hemicellulose to sugars from supercritical ammonia pretreated hardwoods or agricultural byproducts were obtained with a small dosage of cellulase. This technique was

  6. TTUAB PLASTIC RECYCLING PROTOCOL Fall 2011 What Plastic Do We Recycle?

    E-print Network

    Rock, Chris

    TTUAB PLASTIC RECYCLING PROTOCOL ­ Fall 2011 What Plastic Do We Recycle? TTUAB has taken on the responsibility of recycling #1 PET and #2 HDPE plastics by placing a yellow TTUAB Plastic Recycling bin on each recyclables encountered in our bins are ALSO our responsibility (e.g. tin cans, aluminum cans, glass). So

  7. Welcome new and returning residents! Help us make USC greener by recycling! Your Room Recycling Bin

    E-print Network

    Almor, Amit

    Welcome new and returning residents! Help us make USC greener by recycling! Your Room Recycling Bin Every room is provided with a recycling bin to make it easy for you to recycle while living in University Housing. Use this bin to collect mixed recyclables in your room and take them to your nearest

  8. Text recycling: acceptable or misconduct?

    PubMed

    Harriman, Stephanie; Patel, Jigisha

    2014-01-01

    Text recycling, also referred to as self-plagiarism, is the reproduction of an author's own text from a previous publication in a new publication. Opinions on the acceptability of this practice vary, with some viewing it as acceptable and efficient, and others as misleading and unacceptable. In light of the lack of consensus, journal editors often have difficulty deciding how to act upon the discovery of text recycling. In response to these difficulties, we have created a set of guidelines for journal editors on how to deal with text recycling. In this editorial, we discuss some of the challenges of developing these guidelines, and how authors can avoid undisclosed text recycling. PMID:25127654

  9. The College that Recycled Itself

    ERIC Educational Resources Information Center

    Lawrimore, Earl

    1978-01-01

    At Davidson College in North Carolina, a recycling program has turned attics into lecture halls, laboratories, and a museum; a banquet hall is now an art gallery; and the main classroom building was remodeled. (Author/MLF)

  10. Make Your Own Recycled Paper

    NSDL National Science Digital Library

    2014-09-18

    Students learn how paper is made. Working together, student teams make their own paper. This activity introduces students to recycling; what it is, its value and benefits, and how it affects their lives.

  11. Disposal, Degradation, and Recycling; Bioplastics

    NSDL National Science Digital Library

    David Teegarden

    2004-01-01

    Everyone is familiar with plastic waste. We throw away large volumes of it, at home, at school, at work, at fast food restaurants, on vacation. Much of it ends up in the trash. We see some of it as litter along the sides of roads, streams and lakes, and floating up on beaches. We probably recycle some used plastics, although how much depends upon where we live. In many localities, only items produced from PET (polyethylene terephthalate) and HDPE (high-density polyethylene) are collected for recycling. Why don't we recycle more of it? Why not LDPE (low-density polyethylene) and polystyrene? And what happens to it when we do? We'll develop some basic principles in this chapter on some of the avenues that help us follow the U.S. Environmental Protection Agency's advice to "reduce, reuse, recycle."

  12. Progress reported in PET recycling

    SciTech Connect

    Not Available

    1989-06-01

    The Goodyear Polyester Division has demonstrated its ability to break down polyethylene terephthalate (PET) from recycled plastic soft drink bottles and remanufacture the material into PET suitable for containers. Most people are familiar with PET in the form of lightweight, shatter resistant beverage bottles. About 20 percent of these beverage containers currently are being recycled. The recycled PET is currently used in many applications such as carpeting, pillow stuffing, sleeping bag filling, insulation for water heaters and non-food containers. This is the first step of Goodyear's increased efforts to recycle PET from containers into a material suitable for food packing. The project is extremely complex, involving sophisticated understanding of the chemical reactions involved, PET production and the technology testing protocols necessary to design a process that addresses all the technical, safety, and regulatory concerns. The research conducted so far indicated that additional processing beyond simply cleaning the shredded material, called flake, will be required to assure a quality polymer.

  13. Plutonium Multiple Recycling In PWRs

    SciTech Connect

    Nigon, Jean-Louis [COGEMA, DRD, 2 rue Paul Dautier 78141 Velizy - Villacoublay Cedex (France); Lenain, Richard [SERMA, CEA Saclay (France); Zaetta, Alain [SPRC - CEA Cadarache (France)

    2002-07-01

    Reprocessing and recycling open the road to a sustainable management of nuclear materials and an environment friendly management of nuclear waste. However, long or very long term recycling implies fast neutron reactors. High burn-ups of irradiated standard UO{sub 2} fuel as well as recycling of plutonium fuel in thermal reactors lead to a 'degradation' of plutonium that means a low fissile content, which is hardly compatible with recycling in LWRs. Thus the question of plutonium management has been raised; although there are some limitations, a truly large variety of options do exist; no one of the presently selected ways of plutonium management is a dead end road. Among these various options, some are fully compatible with the existing reactors and may be considered for the mid term future; they offer a competitive management of plutonium during the transition from thermal to fast reactors. (authors)

  14. Loopless non-trapping invasion percolation model for fracking

    E-print Network

    Norris, J Quinn; Rundle, John B

    2014-01-01

    Recent developments in hydraulic fracturing (fracking) have enabled the recovery of large quantities of natural gas and oil from old, low permeability shales. These developments include a change from low-volume, high-viscosity fluid injection to high-volume, low-viscosity injection. The injected fluid introduces distributed damage that provides fracture permeability for the extraction of the gas and oil. In order to model this process, we utilize a loopless non-trapping invasion percolation previously introduced to model optimal polymers in a strongly disordered medium, and for determining minimum energy spanning trees on a lattice. We performed numerical simulations on a 2D square lattice and find significant differences from other percolation models. Additionally, we find that the growing fracture network satisfies both Horton-Strahler and Tokunaga network statistics. As with other invasion percolation models, our model displays burst dynamics, in which the cluster extends rapidly into a connected region. W...

  15. Percolation crossing probabilities in hexagons: a numerical study

    NASA Astrophysics Data System (ADS)

    Flores, S. M.; Ziff, R. M.; Simmons, J. J. H.

    2015-01-01

    In a recent article (Simmons 2013 J. Phys. A: Math. Theor. 46 494015), the last author of this article used c = 0 logarithmic conformal field theory to predict crossing probability formulas for percolation clusters inside a hexagon with free boundary conditions. In the present article, we verify these predictions with high-precision computer simulations for equiangular hexagons with side lengths alternating from short to long. Our simulations generate percolation-cluster perimeters with hull walks on a triangular lattice inside a hexagon. Each sample comprises two hull walks, and the order in which these walks strike the bottom and upper left/right sides of the hexagon determines the crossing configuration of the percolation sample. We compare our numerical results with the predicted crossing probabilities, finding excellent agreement.

  16. Critical phenomena in heterogeneous k-core percolation

    NASA Astrophysics Data System (ADS)

    Cellai, Davide; Lawlor, Aonghus; Dawson, Kenneth A.; Gleeson, James P.

    2013-02-01

    k-core percolation is a percolation model which gives a notion of network functionality and has many applications in network science. In analyzing the resilience of a network under random damage, an extension of this model is introduced, allowing different vertices to have their own degree of resilience. This extension is named heterogeneous k-core percolation and it is characterized by several interesting critical phenomena. Here we analytically investigate binary mixtures in a wide class of configuration model networks and categorize the different critical phenomena which may occur. We observe the presence of critical and tricritical points and give a general criterion for the occurrence of a tricritical point. The calculated critical exponents show cases in which the model belongs to the same universality class of facilitated spin models studied in the context of the glass transition.

  17. Directed random walk on the directed percolation cluster Matthias Birkner

    E-print Network

    Mörters, Peter

    ) percolation space Zd time q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q p (0, 1 closed 3/21 #12;Directed percolation Directed (site) percolation space Zd time q q q q q q q q q q q q q

  18. Fast and accurate database searches with MS-GF+Percolator

    PubMed Central

    Granholm, Viktor; Kim, Sangtae; Navarro, José C.F.; Sjölund, Erik; Smith, Richard D.; Käll, Lukas

    2014-01-01

    One can interpret fragmentation spectra stemming from peptides in mass spectrometry-based proteomics experiments using so called database search engines. Frequently, one also runs post-processors such as Percolator to assess the confidence, infer unique peptides and increase the number of identifications. A recent search engine, MS-GF+, has shown promising results, due to a new and efficient scoring algorithm. However, MS-GF+ provides few statistical estimates about the peptide-spectrum matches, hence limiting the biological interpretation. Here, we enabled Percolator-processing for MS-GF+ output, and observed an increased number of identified peptides for a wide variety of datasets. In addition, Percolator directly reports p values and false discovery rate estimates, such as q values and posterior error probabilities, for peptide-spectrum matches, peptides and proteins, functions that are useful for the whole proteomics community. PMID:24344789

  19. Connecting Core Percolation and Controllability of Complex Networks

    PubMed Central

    Jia, Tao; Pósfai, Márton

    2014-01-01

    Core percolation is a fundamental structural transition in complex networks related to a wide range of important problems. Recent advances have provided us an analytical framework of core percolation in uncorrelated random networks with arbitrary degree distributions. Here we apply the tools in analysis of network controllability. We confirm analytically that the emergence of the bifurcation in control coincides with the formation of the core and the structure of the core determines the control mode of the network. We also derive the analytical expression related to the controllability robustness by extending the deduction in core percolation. These findings help us better understand the interesting interplay between the structural and dynamical properties of complex networks. PMID:24946797

  20. Proliferation aspects of plutonium recycling

    Microsoft Academic Search

    Bruno Pellaud

    2002-01-01

    Plutonium recycling offers benefits in an energy perspective of sustainable development, and, moreover it contributes to non-proliferation. Prior to recycling, reactor-grade plutonium from light-water reactors does not lend itself easily to the assembly of explosive nuclear devices; thereafter, practically not at all. Control systems for material security and non-proliferation should identify and adopt several categories of plutonium covering various isotopic

  1. Recycling steel. Conducting a waste audit.

    PubMed

    Crawford, G

    1996-01-01

    This is the second in a series of three articles regarding steel can recycling from foodservice operations of healthcare facilities. This article highlights the basic methods of recycling steel cans, and includes information on conducting a waste audit and negotiating with a hauler regarding the benefits of recycling. The previous article discussed how steel is recycled across the country. The next article will convey a case history of actual foodservice recycling practice from a healthcare facility. PMID:10157569

  2. Consolidated conversion of protein waste into biofuels and ammonia using Bacillus subtilis.

    PubMed

    Choi, Kwon-Young; Wernick, David G; Tat, Christine A; Liao, James C

    2014-05-01

    The non-recyclable use of nitrogen fertilizers in microbial production of fuels and chemicals remains environmentally detrimental. Conversion of protein wastes into biofuels and ammonia by engineering nitrogen flux in Escherichia coli has been demonstrated as a method to reclaim reduced-nitrogen and curb its environmental deposition. However, protein biomass requires a proteolysis process before it can be taken up and converted by any microbe. Here, we metabolically engineered Bacillus subtilis to hydrolyze polypeptides through its secreted proteases and to convert amino acids into advanced biofuels and ammonia fertilizer. Redirection of B. subtilis metabolism for amino-acid conversion required inactivation of the branched-chain amino-acid (BCAA) global regulator CodY. Additionally, the lipoamide acyltransferase (bkdB) was deleted to prevent conversion of branched-chain 2-keto acids into their acyl-CoA derivatives. With these deletions and heterologous expression of a keto-acid decarboxylase and an alcohol dehydrogenase, the final strain produced biofuels and ammonia from an amino-acid media with 18.9% and 46.6% of the maximum theoretical yield. The process was also demonstrated on several waste proteins. The results demonstrate the feasibility of direct microbial conversion of polypeptides into sustainable products. PMID:24566040

  3. Recycling incineration: Evaluating the choices

    SciTech Connect

    Denison, R.A.; Ruston, J. (eds.)

    1993-01-01

    Conflicts between proponents of municipal solid waste incineration and advocates of recycling have escalated with efforts to reduce the volume of waste that ends up in landfills. Central to this debate is competition for materials that are both combustible and recyclable. Environmental and economic concerns also play a major role. This book, produced by the Environmental Defense Fund, compares recycling and incineration. It is intended for citizens, government officials, and business people who want to help resolve the solid-waste crisis.' The book is divided into three parts: recycling and incineration; health and environmental risk of incineration; and planning, public participation, and environmental review requirements. The book does an excellent job of discussing the benefits of recycling and the pitfalls of incineration. It provides helpful information for identifying questions that should be raised about incineration, but it does not raise similar queries about recycling. There is much worthwhile information here, but the book would be more useful if it identified critical issues for all waste reduction and management options.

  4. Disposable product design and recycling

    SciTech Connect

    Stessel, R.I. [Univ. of South Florida, Tampa, FL (United States). Dept. of Civil and Environmental Engineering

    1996-09-01

    Of late, recycling has lost some of its luster, even as prices are increasing for recovered materials. First, collection costs continue to be high. Second, recycling rates seem to be leveling off. These two difficulties are related. The paper begins with an overview of the causes of these problems, concluding, as have many practitioners, that an increase in automation is required. Automation expands options for solving some of the problems, but the structure of the recycling industry, embodying a fundamental disconnect between producers of consumer products and waste management, raises special difficulties. Consumer product companies have done their best to be environmentally responsible, studying packaging reduction, sales of concentrated products, etc. They have included recycled content in packages. However, few significant steps have been taken to increase the recyclability of the products; elimination of base cups in PET (polyethylene terephthalate) bottles is a notable exception. This paper explores the gap between product design and recyclability. It brings the missing component to packaging design: the technology of materials recovery. The objective was to develop overriding design concepts.

  5. Key recycling in authentication

    E-print Network

    Christopher Portmann

    2014-09-29

    In their seminal work on authentication, Wegman and Carter propose that to authenticate multiple messages, it is sufficient to reuse the same hash function as long as each tag is encrypted with a one-time pad. They argue that because the one-time pad is perfectly hiding, the hash function used remains completely unknown to the adversary. Since their proof is not composable, we revisit it using a composable security framework. It turns out that the above argument is insufficient: if the adversary learns whether a corrupted message was accepted or rejected, information about the hash function is leaked, and after a bounded finite amount of rounds it is completely known. We show however that this leak is very small: Wegman and Carter's protocol is still $\\epsilon$-secure, if $\\epsilon$-almost strongly universal$_2$ hash functions are used. This implies that the secret key corresponding to the choice of hash function can be reused in the next round of authentication without any additional error than this $\\epsilon$. We also show that if the players have a mild form of synchronization, namely that the receiver knows when a message should be received, the key can be recycled for any arbitrary task, not only new rounds of authentication.

  6. Mercury recovering and recycling

    SciTech Connect

    Weyand, T.E.; Rose, M.V.

    1995-11-01

    Efficient, economical treatment of mercury-contaminated soils and industrial wastes requires a treatment process that reduces mercury content to near background levels and recovers the removed mercury in pure recyclable form without producing liquid, solid, or gaseous secondary wastes. Mercury Recovery Services, Inc. has successfully developed and placed commercial operation a medium-temperature thermal desorption process that has into co successfully achieved these goals. The efficacy of the MRS Process to treat mercury-contaminated soils and industrial wastes was first Demonstrated on a pilot scale by means of treating (a) simulated soils containing varying amounts of metallic mercury, mercury oxide, mercury sulfide and mercury chloride, (b) actual natural gas metering site pipeline clay, sandy, and loam soils having total mercury contents in the range of 250 ppm to 15,000 ppm, and (c) waste water treatment sludges from chloralkali production containing up to 20,000 ppm mercury and large significant concentrations of sulfur and chlorine. In every case, the residual total mercury content was reduced to less than 2 ppm after treatment. The performance of MRS` first mobile commercial thermal desorption unit compares very favorably with the previously reported pilot-scale results.

  7. Dense Percolation in Large-Scale Mean-Field Random Networks is Provably "Explosive"

    E-print Network

    Krokhmal, Paul

    1 Dense Percolation in Large-Scale Mean-Field Random Networks is Provably "Explosive" Alexander Recent reports suggest that evolving large-scale networks exhibit "explosive percolation": a large In recent years, "explosive percolation" in large-scale random networks has received substantial attention

  8. OrnsteinZernike behavior for the Bernoulli bond percolation on Z d in the supercritical regime

    E-print Network

    Ornstein­Zernike behavior for the Bernoulli bond percolation on Z d in the supercritical regime G percolation process on Z d , along the principal directions, for d # 3, and for supercritical values of p su#ciently near to p = 1. Key Words: Supercritical bond percolation, polymer expansion, Ornstein­Zernike behavior

  9. Double percolation in the electrical conduction in carbon fiber reinforced cement-based materials

    E-print Network

    Chung, Deborah D.L.

    conduction in carbon fiber cement-based materials. It involves fiber percolation and cement paste percolation.% fibers in the paste portion. The cement paste percolation threshold is between 70 and 76 vol.% carbon fiber cement paste in the mortar. A sand volume fraction of 24% or less (i.e., a sand/cement ratio of 0

  10. Construction of the incipient infinite cluster for spread-out oriented percolation above 4 + 1 dimensions

    E-print Network

    Hofstad, Remco van der

    Construction of the incipient infinite cluster for spread-out oriented percolation above 4 + 1 the incipient infinite cluster measure (IIC) for sufficiently spread-out ori- ented percolation on Zd × Z paper to relate critical oriented percolation to super-Brownian motion, for d + 1 > 4 + 1. 1

  11. Construction of the incipient infinite cluster for spreadout oriented percolation above 4 + 1 dimensions

    E-print Network

    Slade, Gordon

    Construction of the incipient infinite cluster for spread­out oriented percolation above 4 + 1 the incipient infinite cluster measure (IIC) for su#ciently spread­out ori­ ented percolation on Z d × Z in a previous paper to relate critical oriented percolation to super­Brownian motion, for d + 1 > 4 + 1. 1

  12. Microwave Absorption in Percolating Metal-insulator Composites

    NASA Astrophysics Data System (ADS)

    Zimmerman, Darin; Cardellino, Jeremy; Cravener, Kyle; Feather, Kelly; Miskovsky, Nicholas; Weisel, Gary

    2009-03-01

    We measure several electromagnetic properties of tungsten-Teflon composites as a function of metal volume concentration. The electric (E) and magnetic (H) loss tangents at 2.45 GHz and the dc conductivity each exhibit a percolation transition at a different critical value of the metal volume fraction, p. Moreover, the transition behavior depends on the average particle size and size distribution of the metal component. We explain the variation in each case by a schematic model derived from established percolation theory and the distinct response of conducting particles to microwave electric and magnetic fields.

  13. Microwave absorption in percolating metal-insulator composites

    NASA Astrophysics Data System (ADS)

    Zimmerman, D. T.; Cardellino, J. D.; Cravener, K. T.; Feather, K. R.; Miskovsky, N. M.; Weisel, G. J.

    2008-11-01

    We measure several electromagnetic properties of tungsten-Teflon composites as a function of metal volume concentration. The electric (E) and magnetic (H) loss tangents at 2.45GHz and the dc conductivity each exhibits a percolation transition at a different critical value of the metal volume fraction p. Moreover, the transition behavior depends on the average particle size and size distribution of the metal component. We explain the variation in each case by a schematic model derived from established percolation theory and the distinct response of conducting particles to microwave electric and magnetic fields.

  14. Percolation and epidemics in a two-dimensional small world

    NASA Astrophysics Data System (ADS)

    Newman, M. E.; Jensen, I.; Ziff, R. M.

    2002-02-01

    Percolation on two-dimensional small-world networks has been proposed as a model for the spread of plant diseases. In this paper we give an analytic solution of this model using a combination of generating function methods and high-order series expansion. Our solution gives accurate predictions for quantities such as the position of the percolation threshold and the typical size of disease outbreaks as a function of the density of ``shortcuts'' in the small-world network. Our results agree with scaling hypotheses and numerical simulations for the same model.

  15. Interaction between a percolation network and a cubic cavity

    NASA Astrophysics Data System (ADS)

    Mourzenko, Valeri; Adler, Pierre; Thovert, Jean Francois; Sangaré, Daouda

    2015-04-01

    The intersection between a percolating network of fractures modeled as polygons and a cubic cavity is important for the safe storage of wastes in a fractured medium. The cavities where the wastes are stored should not intersect the percolating network of fractures which may exist, or these cavities should not enable a fracture network to percolate. The fractures are hexagons inscribed in a circle of radius R which are uniformly distributed in space and isotropically oriented. Nfr is the number of fractures generated in a finite unit cell Omega of size L^3. The fracture density is conveniently represented by the dimensionless density rho ' which is the average number of intersections per fracture with the other fractures [1]. In addition, a cubic cavity C formed by six squares inscribed in a circle of radius Rs is randomly located in Omega. N spatially periodic networks are generated. Generally, N is equal to 500. Among these N networks, Np percolate and the cavity intersects one or more fractures in Nrc realizations; no fracture-cavity intersection occurs in Nnrc realizations. Moreover, when the network alone does not percolate (which occurs in Nnp realisations), the set composed by the hexagons and the cavity percolates Nnpc times. These quantities and the corresponding probabilities were systematically calculated as functions of L' = L/R , R' s = R_s/R and rho'. An important quantity is the conditional probability Pic that the percolating cluster intersects the cavity when it exists. It could be extrapolated to an infinite cell size L'. This conditional probability is an increasing function of rho' and of R' _s. The probability Pi that an object X intersects the fracture network with the density rho is given by the expression Pi=1-exp(- rho V) where V is the excluded volume for the object X and a fracture. This quantity is obtained for a cube. This prediction is in good agreement with the conditional probability Pic for large rho' or small R_s. However, Pi and Pic are not totally comparable because Pi is the probability for the intersection with the whole network and not with the percolation cluster only. Additional data will be presented and discussed.

  16. Multi-component removal in flue gas by aqua ammonia

    DOEpatents

    Yeh, James T. (Bethel Park, PA); Pennline, Henry W. (Bethel Park, PA)

    2007-08-14

    A new method for the removal of environmental compounds from gaseous streams, in particular, flue gas streams. The new method involves first oxidizing some or all of the acid anhydrides contained in the gas stream such as sulfur dioxide (SO.sub.2) and nitric oxide (NO) and nitrous oxide (N.sub.2O) to sulfur trioxide (SO.sub.3) and nitrogen dioxide (NO.sub.2). The gas stream is subsequently treated with aqua ammonia or ammonium hydroxide which captures the compounds via chemical absorption through acid-base or neutralization reactions. The products of the reactions can be collected as slurries, dewatered, and dried for use as fertilizers, or once the slurries have been dewatered, used directly as fertilizers. The ammonium hydroxide can be regenerated and recycled for use via thermal decomposition of ammonium bicarbonate, one of the products formed. There are alternative embodiments which entail stoichiometric scrubbing of nitrogen oxides and sulfur oxides with subsequent separate scrubbing of carbon dioxide.

  17. Nitrogen recycling for sustainable agriculture

    Microsoft Academic Search

    J. Takahashi

    Summary The innovation of synthetic ammonia by the Harber-Bosch process has contributed greatly to an increase in food production and an unprecedented expansion of the world population. It has come to supply 1\\/3 of the amount of protein now assumed to be necessary for the world population of 6 billion people. That is, only a population of 4 billion people

  18. Rethinking Recycling in Arcs

    NASA Astrophysics Data System (ADS)

    Kelemen, P.; Behn, M. D.; Jagoutz, O.

    2012-12-01

    Hacker et al EPSL 2011 and Behn et al Nature Geosci 2011 investigated pathways for return of buoyant, subducted material to arc crust. These include (1) diapirs rising into the hot mantle wedge, with extensive melts adding a component to arc magmas, (2) flow of material back up a relatively cold "subduction channel", adding solids to the lower crust and small-degree partial melts to the upper crust, (3) flow from the forearc along the base of arc crust, and (4) imbrication of forearc material into arc crust. These processes add felsic, incompatible-element-rich components to arc crust. The flux of incompatible elements such as Th in arc lavas, thought to be mainly recycled from subducted sediments, is > sediment subduction flux. There are large uncertainties: arc crustal growth rates are imprecise; young, primitive arc lavas may not be representative of magmatic flux into arc crust; sediment subduction flux may have varied. Nevertheless, this result is found for all arcs examined, using recently published growth rates. Perhaps arc growth rates that include subduction erosion are systematically overestimated. Instead or in addition, maybe significant Th comes from material other than sediments. Here, we consider the implications of pathways 1-4 for arc growth rates and incompatible element enrichment, in the context of subduction erosion and arc-arc collision. Subducting arc lithologies can become separated, with only felsic components returned to arc crust. Buoyant lithologies are mobile in viscous instabilities at > 700-800°C. Whereas thin layers such as sediments may become mobile all at once, instabilities may periodically strip the hottest parts from the top of thick buoyant layers, replacing them with hot mantle. In arc-arc collision, the top of a subducting plate starts at about 0°C on the seafloor, so heating is slow. In subduction erosion, forearc material in the subducting package can be > 200°C before erosion so buoyant lithologies reach 700-800°C faster, and in larger volumes at a given time. Subduction erosion rarely, if ever, transports significant amounts of buoyant material deep into the convecting mantle. Because buoyant material can remain part of the crust, it may often be a mistake to add all of the eroded material to the observed arc volume to derive crustal growth rates. Buoyancy instabilities during subduction erosion or arc-arc collision will accumulate felsic arc crust. For example, > 50% of Aleutian arc lavas and exposed plutons are more buoyant than mantle peridotite at 700-800°C, 3-4 GPa. The buoyant material has an average of 60-62 wt% SiO2, molar Mg/(Mg+Fe) 0.4-0.5, and trace elements identical to bulk continental crust, though western Aleutian lavas have the most depleted Sr, Nd and Pb isotope ratios of all arc lavas worldwide. In general, density sorting of arc lithologies, and subsequent partial melting as buoyant rocks rise through the mantle wedge or along a subduction channel, could lead to a kind of double and triple distillation. Incompatible elements such as Th would be enriched in arc crust, retaining correlations with isotopic indicators of a recycled sediment component, while Th-poor, dense, mafic lavas and lower crustal cumulates return to the convecting mantle.

  19. Deep Recycling of Carbon

    NASA Astrophysics Data System (ADS)

    Schmidt, M. W.

    2012-12-01

    While most of the subducted H2O is recycled at shallow and subarc depths, carbon is less readily mobilized and susceptive to complex redox processes involving CO2 in solids, fluids and melts, elemental carbon, Fe- and Si- carbides, and methane. Here I review the various ways of recycling carbon during subduction and present a spectrum of possible reaction products in the mantle. Metamorphic reactions liberate <20% of the subducted CO2 to the subarc region (Connolly 2005, EPSL). Larger amounts might be mobilized through (sediment) melting. Although the wet pelite solidus is only shifted by 30-50 oC (at 3 GPa) with carbonates, the latter remain stable with melts that are saturated in a H2O+CO2-fluid. Complete dissolution of carbonates requires temperatures above any predicted subduction geotherm. Carbonated sediments yield CO2-rich phonolites to 5 GPa but carbonatites at higher pressures. The silicate melts become increasingly potassic with pressure, while the alkali-rich carbonatites have their highest K/Na at 8 GPa, slightly decreasing to 13 GPa and become sodic with the disappearance of residual cpx at ~16 GPa. What may happen when carbonated pelite derived melts migrate into the mantle is illustrated in Central Italy: in this case, it can be experimentally demonstrated that hybridization of ultrapotassic phonolitic melts with ~2 wt% H2O and ~6 wt% CO2 in the mantle results in the primitive parents of the ultrapotassic kamafugite suites which have ~43 wt% SiO2. Hence, despite a crustal isotopic signature of C, O, and Sr in these rocks, the CO2 of the Italian magmatism does not stem from assimilation in the crust but from melts derived from subducted marine carbonates mixed with pelagic clays and then reacted in the mantle. The migration of CO2-bearing fluids and melts into the mantle may lead to a redox-shock. Where high liquid/mantle ratios prevail, carbonatites rest in their oxidized form and may only freeze in relatively cold lithospheric keels where they form metasomatic zones prone to generate kimberlites in the context of a much later remelting event. Where the redox-capacity of the oxidized crust-derived material is subequal to the reduced mantle, iron carbides are to be expected. The eutectic in the Fe-Ni-C system is at lower temperatures than the mantle adiabat, leading to the distinct possibility that such zones entrained in global mantle convection will contain ~1% of eutectic Fe-C-melt. When the amount of subduction derived CO2 is small compared to the redox capacity of a metal bearing reduced mantle, diamond will form, but diamond itself is not truly reducing at high pressures. The most extreme reducing case leads to moissanite (found together with diamond), which isotopic signature implies involvement of organically derived carbon. Moissanite (SiC) only forms at fO2 <6-8 log units below iron-wustite and coexists with mantle silicates that have an XMg of 0.995-0.998. Our calculations show that a fluid or melt with a bulk, which is slightly more reduced than the CO2-H2O-tieline in C-O-H, may evolve to ultra-reduced residual C-H-rich fluids through removal of CO2 (through carbonate precipitation) followed by removal of H2O (through hydrous silicate formation). As SiC may only be in grain scale equilibrium with the mantle and requires a protracted fluid-fractionation, we propose that SiC is generally a low temperature phase formed from originally already reducing fluids involving organic carbon and hence subduction.

  20. Nitrogen recycling and nutritional provisioning by Blattabacterium, the cockroach endosymbiont

    PubMed Central

    Sabree, Zakee L.; Kambhampati, Srinivas; Moran, Nancy A.

    2009-01-01

    Nitrogen acquisition and assimilation is a primary concern of insects feeding on diets largely composed of plant material. Reclaiming nitrogen from waste products provides a rich reserve for this limited resource, provided that recycling mechanisms are in place. Cockroaches, unlike most terrestrial insects, excrete waste nitrogen within their fat bodies as uric acids, postulated to be a supplement when dietary nitrogen is limited. The fat bodies of most cockroaches are inhabited by Blattabacterium, which are vertically transmitted, Gram-negative bacteria that have been hypothesized to participate in uric acid degradation, nitrogen assimilation, and nutrient provisioning. We have sequenced completely the Blattabacterium genome from Periplaneta americana. Genomic analysis confirms that Blattabacterium is a member of the Flavobacteriales (Bacteroidetes), with its closest known relative being the endosymbiont Sulcia muelleri, which is found in many sap-feeding insects. Metabolic reconstruction indicates that it lacks recognizable uricolytic enzymes, but it can recycle nitrogen from urea and ammonia, which are uric acid degradation products, into glutamate, using urease and glutamate dehydrogenase. Subsequently, Blattabacterium can produce all of the essential amino acids, various vitamins, and other required compounds from a limited palette of metabolic substrates. The ancient association with Blattabacterium has allowed cockroaches to subsist successfully on nitrogen-poor diets and to exploit nitrogenous wastes, capabilities that are critical to the ecological range and global distribution of cockroach species. PMID:19880743

  1. Cluster decomposition of percolation probability on the hexagonal lattice

    E-print Network

    E. S. Antonova; Yu. P. Virchenko

    2009-09-29

    The upper estimate of the percolation threshold of the Bernoulli random field on the hexagonal lattice is found. It is done on the basis of the cluster decomposition. Each term of the decomposition is estimated using the number estimate of cycles on the hexagonal lattice which represent external borders of possible finite clusters containing the fixed lattice vertex.

  2. Percolative theories of strongly disordered ceramic high-temperature superconductors

    PubMed Central

    Phillips, J. C.

    2010-01-01

    Optimally doped ceramic superconductors (cuprates, pnictides, etc.) exhibit transition temperatures T c much larger than strongly coupled metallic superconductors like Pb (T c = 7.2 K, E g/kT c = 4.5) and exhibit many universal features that appear to contradict the Bardeen, Cooper, and Schrieffer theory of superconductivity based on attractive electron-phonon pairing interactions. These complex materials are strongly disordered and contain several competing nanophases that cannot be described effectively by parameterized Hamiltonian models, yet their phase diagrams also exhibit many universal features in both the normal and superconductive states. Here we review the rapidly growing body of experimental results that suggest that these anomalously universal features are the result of marginal stabilities of the ceramic electronic and lattice structures. These dual marginal stabilities favor both electronic percolation of a dopant network and rigidity percolation of the deformed lattice network. This “double percolation” model has previously explained many features of the normal-state transport properties of these materials and is the only theory that has successfully predicted strict lowest upper bounds for T c in the cuprate and pnictide families. Here it is extended to include Coulomb correlations and percolative band narrowing, as well as an angular energy gap equation, which rationalizes angularly averaged gap/T c ratios, and shows that these are similar to those of conventional strongly coupled superconductors. PMID:20080578

  3. Polymer Collapse, Protein Folding, and the Percolation Threshold

    E-print Network

    Meirovitch, Hagai

    Polymer Collapse, Protein Folding, and the Percolation Threshold HAGAI MEIROVITCH University (Macromolecules 1989, 22, 3986­3997) to study protein folding, where H and P are the hydrophobic and polar amino; computer simulation; collapse transition; protein folding Introduction The behavior of dilute polymer

  4. Given enough choice, simple local rules percolate discontinuously

    NASA Astrophysics Data System (ADS)

    Waagen, Alex; D'Souza, Raissa M.

    2014-12-01

    There is still much to discover about the mechanisms and nature of discontinuous percolation transitions. Much of the past work considers graph evolution algorithms known as Achlioptas processes in which a single edge is added to the graph from a set of k randomly chosen candidate edges at each timestep until a giant component emerges. Several Achlioptas processes seem to yield a discontinuous percolation transition, but it was proven by Riordan and Warnke that the transition must be continuous in the thermodynamic limit. However, they also proved that if the number k(n) of candidate edges increases with the number of nodes, then the percolation transition may be discontinuous. Here we attempt to find the simplest such process which yields a discontinuous transition in the thermodynamic limit. We introduce a process which considers only the degree of candidate edges and not component size. We calculate the critical point tc = (1 - ?(1/k))n and rigorously show that the critical window is of size O(n/k(n)) . If k(n) grows very slowly, for example k(n) = log n, the critical window is barely sublinear and hence the phasetransition is discontinuous but appears continuous in finite systems. We also present arguments that Achlioptas processes with bounded size rules will always have continuous percolation transitions even with infinite choice.

  5. QUENCHED INVARIANCE PRINCIPLE FOR SIMPLE RANDOM WALK ON PERCOLATION CLUSTERS

    E-print Network

    include, e.g., various diluted spin systems, random copolymers [21], spin glasses [5,22], random, information about the scaling properties of simple random walk on percolation cluster can, in principle C# = C# (#) for the set C# (#) = # x # Z d : x # ### # . (1.1) By Burton­Keane's Uniqueness theorem

  6. Triangle percolation in mean field random graphs -- with PDE

    E-print Network

    Balázs Ráth; Bálint Tóth

    2008-03-03

    We apply a PDE-based method to deduce the critical time and the size of the giant component of the ``triangle percolation'' on the Erd\\H{o}s-R\\'enyi random graph process investigated by Palla, Der\\'enyi and Vicsek

  7. A Proof of Factorization Formula for Critical Percolation

    NASA Astrophysics Data System (ADS)

    Beliaev, Dmitri; Izyurov, Konstantin

    2012-03-01

    We give mathematical proofs to a number of statements which appeared in the series of papers by Simmons et al. (Phys Rev E 76(4):041106, 2007; J Stat Mech Theory Exp 2009(2):P02067, 33, 2009) where they computed the probabilities of several percolation events.

  8. The Use of Percolating Filters in Teaching Ecology.

    ERIC Educational Resources Information Center

    Gray, N. F.

    1982-01-01

    Using percolating filters (components of sewage treatment process) reduces problems of organization, avoids damage to habitats, and provides a local study site for field work or rapid collection of biological material throughout the year. Component organisms are easily identified and the habitat can be studied as a simple or complex system.…

  9. Interpretation of percolation in terms of infinity computations

    E-print Network

    D. I. Iudin; Ya. D. Sergeyev; M. Hayakawa

    2012-05-03

    In this paper, a number of traditional models related to the percolation theory has been considered by means of new computational methodology that does not use Cantor's ideas and describes infinite and infinitesimal numbers in accordance with the principle `The part is less than the whole'. It gives a possibility to work with finite, infinite, and infinitesimal quantities numerically by using a new kind of a computer - the Infinity Computer - introduced recently in by Ya.D. Sergeyev in a number of patents. The new approach does not contradict Cantor. In contrast, it can be viewed as an evolution of his deep ideas regarding the existence of different infinite numbers in a more applied way. Site percolation and gradient percolation have been studied by applying the new computational tools. It has been established that in an infinite system the phase transition point is not really a point as with respect of traditional approach. In light of new arithmetic it appears as a critical interval, rather than a critical point. Depending on "microscope" we use this interval could be regarded as finite, infinite and infinitesimal short interval. Using new approach we observed that in vicinity of percolation threshold we have many different infinite clusters instead of one infinite cluster that appears in traditional consideration.

  10. Levitation and percolation in quantum Hall systems with correlated disorder

    Microsoft Academic Search

    Hui Song; Isao Maruyama; Yasuhiro Hatsugai

    2007-01-01

    We investigate the integer quantum Hall system in a two dimensional lattice model with spatially correlated disorder by using the efficient method to calculate the Chern number proposed by Fukui [J. Phys. Soc. Jpn. 74, 1674 (2005)]. Distribution of charge density indicates that the extended states at the center of each Landau band have percolating current paths, which are topologically

  11. Continuous time random walk approach to dynamic percolation

    NASA Astrophysics Data System (ADS)

    Hilfer, R.; Orbach, R.

    1988-12-01

    We present an approximate solution for time (frequency) dependent response under conditions of dynamic percolation which may be related to excitation transfer in some random structures. In particular, we investigate the dynamics of structures where one random component blocks a second (carrier) component. Finite concentrations of the former create a percolation network for the latter. When the blockers are allowed to move in time, the network seen by the carriers changes with time, allowing for long-range transport even if the instantaneous carrier site availability is less than pc, the critical percolation concentration. A specific example of this situation is electrical transport in sodium ??-alumina. The carriers are Na + ions which can hop on a two-dimensional honeycomb lattice. The blockers are ions of much higher activation energy, such as Ba 2+. We study the frequency dependence of the conductivity for such a system. Given a fixed Ba 2+ hopping rate, 1/?, the Na + ions experience a frozen site percolation environment for frequencies ? > 1/?. At frequencies ? < 1/?, the Na + ions experience a dynamic environment which allows long-range transport, even below pc. A continuous time random walk model combined with an effective medium approximation allows us to arrive at a numerical solution for the frequency-dependent Na+ conductivity ?(?) which clearly exhibits the crossover from frozen to dynamic environment.

  12. The persistent percolation of single-stream voids

    NASA Astrophysics Data System (ADS)

    Falck, B.; Neyrinck, M. C.

    2015-07-01

    We study the nature of voids defined as single-stream regions that have not undergone shell-crossing. We use ORIGAMI to determine the cosmic web morphology of each dark matter particle in a suite of cosmological N-body simulations, which explicitly calculates whether a particle has crossed paths with others along multiple sets of axes and does not depend on a parameter or smoothing scale. The theoretical picture of voids is that of expanding underdensities with borders defined by shell-crossing. We find instead that locally underdense single-stream regions are not bounded on all sides by multi-stream regions, thus they percolate, filling the simulation volume; we show that the set of multi-stream particles also percolates. This percolation persists to high resolution, where the mass fraction of single-stream voids is low, because the volume fraction remains high; we speculate on the fraction of collapsed mass in the continuum limit of infinite resolution. By introducing a volume threshold parameter to define underdense void `cores', we create a catalogue of ORIGAMI voids which consist entirely of single-stream particles and measure their percolation properties, volume functions, and average densities.

  13. DIAMETERS IN SUPERCRITICAL RANDOM GRAPHS VIA FIRST PASSAGE PERCOLATION

    E-print Network

    Lubetzky, Eyal

    DIAMETERS IN SUPERCRITICAL RANDOM GRAPHS VIA FIRST PASSAGE PERCOLATION JIAN DING, JEONG HAN KIM-R´enyi random graph G(n, p) in the emerging supercritical phase, i.e., for p = 1+ n where 3 n and = o(1 on the diameter, how- ever these did not cover the entire supercritical regime (namely, when 3 n arbitrarily

  14. The diameter of a long range percolation graph

    Microsoft Academic Search

    Don Coppersmith; David Gamarnik; Maxim Sviridenko

    2002-01-01

    One can model a social network as a long-range percolation model on a graph {0, 1, …, N}2. The edges (x, y) of this graph are selected with probability ? ?\\/||x - ys if ||x - y|| > 1, and with probability 1 if ||x - y|| = 1, for some parameters ?, s > 0. That is, people are

  15. Continuum percolation threshold for permeable aligned cylinders and opportunistic networking

    E-print Network

    Hyytiä, Esa

    for all ratios of the height to the diameter of the base, and corresponds to the mean node degree of 1 connected component emerges in the network. I. INTRODUCTION In the continuum percolation problem, objects], c = 0.289573± 0.000002. Similarly, Baker et al. considered both aligned and isotropically oriented

  16. Percolation induced heat transfer in deep unsaturated zones

    USGS Publications Warehouse

    Lu, N.; LeCain, G.D.

    2003-01-01

    Subsurface temperature data from a borehole located in a desert wash were measured and used to delineate the conductive and advective heat transfer regimes, and to estimate the percolation quantity associated with the 1997-1998 El Ni??no precipitation. In an arid environment, conductive heat transfer dominates the variation of shallow subsurface temperature most of the time, except during sporadic precipitation periods. The subsurface time-varying temperature due to conductive heat transfer is highly correlated with the surface atmospheric temperature variation, whereas temperature variation due to advective heat transfer is strongly correlated with precipitation events. The advective heat transfer associated with precipitation and infiltration is the focus of this paper. Disruptions of the subsurface conductive temperature regime, associated with the 1997-1998 El Ni??no precipitation, were detected and used to quantify the percolation quantity. Modeling synthesis using a one-dimensional coupled heat and unsaturated flow model indicated that a percolation per unit area of 0.7 to 1.3 m height of water in two weeks during February 1998 was responsible for the observed temperature deviations down to a depth of 35.2 m. The reported study demonstrated quantitatively, for the first time, that the near surface temperature variation due to advective heat transfer can be significant at a depth greater than 10 m in unsaturated soils and can be used to infer the percolation amount in thick unsaturated soils.

  17. Two Types of Discontinuous Percolation Transitions in Cluster Merging Processes.

    PubMed

    Cho, Y S; Kahng, B

    2015-01-01

    Percolation is a paradigmatic model in disordered systems and has been applied to various natural phenomena. The percolation transition is known as one of the most robust continuous transitions. However, recent extensive studies have revealed that a few models exhibit a discontinuous percolation transition (DPT) in cluster merging processes. Unlike the case of continuous transitions, understanding the nature of discontinuous phase transitions requires a detailed study of the system at hand, which has not been undertaken yet for DPTs. Here we examine the cluster size distribution immediately before an abrupt increase in the order parameter of DPT models and find that DPTs induced by cluster merging kinetics can be classified into two types. Moreover, the type of DPT can be determined by the key characteristic of whether the cluster kinetic rule is homogeneous with respect to the cluster sizes. We also establish the necessary conditions for each type of DPT, which can be used effectively when the discontinuity of the order parameter is ambiguous, as in the explosive percolation model. PMID:26148542

  18. Effect of dietary protein restriction on renal ammonia metabolism.

    PubMed

    Lee, Hyun-Wook; Osis, Gunars; Handlogten, Mary E; Guo, Hui; Verlander, Jill W; Weiner, I David

    2015-06-15

    Dietary protein restriction has multiple benefits in kidney disease. Because protein intake is a major determinant of endogenous acid production, it is important that net acid excretion change in parallel during protein restriction. Ammonia is the primary component of net acid excretion, and inappropriate ammonia excretion can lead to negative nitrogen balance. Accordingly, we examined ammonia excretion in response to protein restriction and then we determined the molecular mechanism of the changes observed. Wild-type C57Bl/6 mice fed a 20% protein diet and then changed to 6% protein developed an 85% reduction in ammonia excretion within 2 days, which persisted during a 10-day study. The expression of multiple proteins involved in renal ammonia metabolism was altered, including the ammonia-generating enzymes phosphate-dependent glutaminase (PDG) and phosphoenolpyruvate carboxykinase (PEPCK) and the ammonia-metabolizing enzyme glutamine synthetase. Rhbg, an ammonia transporter, increased in expression in the inner stripe of outer medullary collecting duct intercalated cell (OMCDis-IC). However, collecting duct-specific Rhbg deletion did not alter the response to protein restriction. Rhcg deletion did not alter ammonia excretion in response to dietary protein restriction. These results indicate 1) dietary protein restriction decreases renal ammonia excretion through coordinated regulation of multiple components of ammonia metabolism; 2) increased Rhbg expression in the OMCDis-IC may indicate a biological role in addition to ammonia transport; and 3) Rhcg expression is not necessary to decrease ammonia excretion during dietary protein restriction. PMID:25925252

  19. The McGraw-Hill recycling handbook

    SciTech Connect

    Lund, H.F.

    1992-01-01

    This reference begins with an overview of recycling, federal, local and state legislation, municipal and commercial waste streams, setting recycling priorities, separation and collection systems, processing facilities, marketing problems and solutions, public awareness programs, and the psychology of recycling. The second section covers recyclable materials, providing information on collection, processing, transportation, marketing, new product potential, and costs. The book offers details on facility design and recycling equipment, and a section on the implementation and control of recycling. Extensive appendixes, a glossary, and an index are included.

  20. Network representation of pore scale imagery for percolation models

    NASA Astrophysics Data System (ADS)

    Klise, K. A.; McKenna, S. A.; Read, E.; Karpyn, Z. T.; Celauro, J.

    2012-12-01

    Multiphase flow under capillary dominated flow regimes is driven by an intricate relationship between pore geometry, material and fluid properties. In this research, high-resolution micro-computed tomography (CT) imaging experiments are used to investigate structural and surface properties of bead packs, and how they influence percolation pathways. Coreflood experiments use a mix of hydrophilic and hydrophobic beads to track the influence of variable contact angle on capillary flow. While high-resolution CT images can render micron scale representation of the pore space, data must be upscaled to capture pore and pore throat geometry for use in percolation models. In this analysis, the pore space is upscaled into a network representation based on properties of the medial axis. Finding the medial axis using micron scale images is computationally expensive. Here, we compare the efficiency and accuracy of medial axes using erosion-based and watershed algorithms. The resulting network representation is defined as a ball-and-stick model which represents pores and pore throats. The ball-and-stick model can be further reduced by eliminating sections of the network that fall below a capillary pressure threshold. In a system of mixed hydrophilic and hydrophobic beads, capillary pressure can change significantly throughout the network based on the interaction between surface and fluid properties. The upscaled network representations are used in percolation models to estimate transport pathway. Current results use a basic percolation model that sequentially fills neighboring pores with the highest potential. Future work will expand the percolation model to include additional mechanics, such as trapping, vacating pores, and viscous fingering. Results from the coreflood experiments will be used to validate upscaling techniques and percolation models. Preliminary results show that the relative strength of water-wet and oil-wet surfaces has a significant impact on percolation. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  1. Influence of carbon nanotube dimensions on the percolation characteristics of carbon nanotube/polymer composites

    NASA Astrophysics Data System (ADS)

    Shehzad, Khurram; Ahmad, Mirza Nadeem; Hussain, Tajamal; Mumtaz, Muhammad; Shah, Asma Tufail; Mujahid, Adnan; Wang, Chao; Ellingsen, Josef; Dang, Zhi-Min

    2014-08-01

    The effect of carbon nanotube aspect ratio (AR) on the percolation characteristics of their polymer composites was investigated by melt blending the multi-wall carbon nanotubes (MWCNTs) with different AR with a thermoplastic elastomer. Previously, most studies reported the effect of aspect ratio of MWCNTs only in the context of achieving the maximum electrical conductivity at lower percolation thresholds in the polymer composites. In this study, our results indicate that aspect ratio can also influence other percolation properties such as the pre-percolation conductivity, percolation conductivity and post-percolation conductivity, shape of the percolation curve, and the width of the insulator-conductor transition. We have established that AR can be used to tailor the percolation curves from sharp to quasi-linear ones, which can help us fabricate the percolative composites with stable electrical properties. Experimental results suggested that the mathematically calculated nominal AR of the MWCNTs was an unclear parameter to correlate with the percolation characteristics of the composites. Instead, an approach taking into consideration the nominal length (l) and the diameter (d) of the MWCNTs individually rather than as a combined AR (l/d) parameter gave a better explanation of the relation between MWCNT dimensions and percolation characteristics.

  2. Sweat ammonia excretion during submaximal cycling exercise.

    PubMed

    Czarnowski, D; Górski, J

    1991-01-01

    This study was undertaken to investigate whether part of the ammonia formed during muscular exercise was excreted with the sweat. Male medical students volunteered for the experiment. They exercised 30 min on a bicycle ergometer at 80 and 40% of the predetermined maximal O2 uptake (VO2max). Exercise at 80% VO2max was performed twice, at room temperature (20 degrees C) and in a cold room (0 degrees C), whereas exercise at 40% was performed only at room temperature (20 degrees C). Blood was collected from the antecubital vein immediately before and after exercise. Sweat was collected from the hypogastric region by use of gauze pads. It was shown that the plasma ammonia level was elevated after exercise at 80% VO2max and remained stable after exercise at 40% VO2max. The volume of sweat produced during exercise at 80% VO2max at 20 degrees C was 428 +/- 138 ml and at 0 degrees C 245 +/- 86 ml and during exercise at 40% VO2max was 183 +/- 69 ml. The ammonia concentration in the sweat after exercise at 80% VO2max at 20 degrees C was 7,140 mumol/l and at 0 degrees C 11,816 mumol/l. After exercise at 40% VO2max, it was 2,076 mumol/l. The total ammonia lost through the sweat during exercise at 80% VO2max was similar at both temperatures, despite the difference in the sweat volume (at 20 degrees C, 3,360 +/- 2,080 mumol; at 0 degrees C, 3,310 +/- 1,250 mumol). During exercise at 40% VO2max, it was 350 +/- 230 mumol. These results show that part of ammonia formed during exercise is lost with sweat. The amount lost increases with increased work rate and the plasma ammonia concentration. PMID:2010396

  3. Recycling Expensive Medication: Why Not?

    PubMed Central

    Pomerantz, Jay M

    2004-01-01

    New (and proposed) advances in packaging, preserving, labeling, and verifying product integrity of individual tablets and capsules may allow for the recycling of certain expensive medicines. Previously sold, but unused, medication, if brought back to special pharmacies for resale or donation, may provide a low-cost source of patent-protected medicines. Benefits of such a program go beyond simply providing affordable medication to the poor. This article suggests that medicine recycling may be a possibility (especially if manufacturers are mandated to blister-package and bar-code individual tablets and capsules). This early discussion of medication recycling identifies relevant issues, such as: need, rationale, existing programs, available supplies, expiration dates, new technology for ensuring safety and potency, environmental impact, public health benefits, program focus, program structure, and liability. PMID:15266231

  4. National Center for Electronics Recycling

    NSDL National Science Digital Library

    Used cellphones and laptops can't go in the recycling with the empty soda cans and cereal boxes. So where do they go to be recycled once consumers find new ones? The National Center for Electronics Recycling (NCER) is working on that very problem. Visitors can click on the "Ecycling Basics" tab on the left side of the page to be taken to links to three websites that allow you to search by zip code or an interactive map of the U.S. In the "Resources" tab on the left side of the page, there are many links to resources that include Advocacy Group Reports, Electronics Disposal Studies, Environmentally Sound Management Guidelines, and International documents. Visitors interested in keeping up with the news from NCER, can sign up for their newsletter in the Google groups box, which is located below the menu on the left side of the page.

  5. Metallic mercury recycling. Final report

    SciTech Connect

    Beck, M.A.

    1994-07-01

    Metallic mercury is known to be a hazardous material and is regulated as such. The disposal of mercury, usually by landfill, is expensive and does not remove mercury from the environment. Results from the Metallic Mercury Recycling Project have demonstrated that metallic mercury is a good candidate for reclamation and recycling. Most of the potential contamination of mercury resides in the scum floating on the surface of the mercury. Pinhole filtration was demonstrated to be an inexpensive and easy way of removing residues from mercury. The analysis method is shown to be sufficient for present release practices, and should be sufficient for future release requirements. Data from tests are presented. The consistently higher level of activity of the filter residue versus the bulk mercury is discussed. Recommendations for the recycling procedure are made.

  6. Energy Savings from Floating Head Pressure in Ammonia Refrigeration Systems

    E-print Network

    Barrer, P. J.; Jones, S. M.

    This paper presents case studies of two moderately sized ammonia refrigeration systems retrofitted for floating head pressure control. It also presents a parametric analysis to assist in selecting appropriate pressures in an ammonia refrigeration...

  7. Biodegradation of bisphenol a and ibuprofen by ammonia oxidizing bacteria 

    E-print Network

    Subramanya, Nethra T.

    2007-09-17

    might be responsible for the removal of these compounds. Several bacterial strains, isolated from waste water, are known to degrade BPA and ibuprofen. No studies, however, have reported using ammonia oxidizing bacteria for this purpose. Ammonia oxidizing...

  8. Estimating ammonia volatilization and deposition from fertilized vegetation

    NASA Astrophysics Data System (ADS)

    Heuer, M. W.; Myles, L.

    2010-12-01

    Deposition of reactive nitrogen in the form of atmospheric ammonia (NH3) affects ecosystem dynamics. Large amounts of atmospheric ammonia can volatilize from fertilized vegetation and deposit to adjacent areas, contributing to changes in soil and plant chemistry. To study the air-surface exchange of ammonia, instrumentation was installed from February 15 through April 12, 2010 at an agricultural research area of managed crops and grassland near Knoxville, TN. A Picarro ammonia analyzer was deployed to measure ammonia at two heights (z = 0.5 m and 2 m) near a plot of winter wheat fertilized with urea. Integrated samples of ammonia were also collected with annular denuder systems at both heights. Concentrations from the Picarro averaged 3-4 ppb of ammonia, but increased by a factor of 20 during fertilization. Fluxes were derived from concurrent measurements of ammonia concentration and air temperature using the flux-gradient method.

  9. Defences against ammonia toxicity in tropical air-breathing fishes exposed to high concentrations of environmental ammonia: a review.

    PubMed

    Ip, Y K; Chew, S F; Wilson, J M; Randall, D J

    2004-10-01

    In the tropics, air-breathing fishes can be exposed to environmental ammonia when stranded in puddles of water during the dry season, during a stay inside a burrow, or after agricultural fertilization. At low concentrations of environmental ammonia, NH(3) excretion is impeded, as in aerial exposure, leading to the accumulation of endogenous ammonia. At high concentrations of environmental ammonia, which results in a reversed NH(3) partial pressure gradient (DeltaP(NH3)), there is retention of endogenous ammonia and uptake of exogenous ammonia. In this review, several tropical air-breathing fishes (giant mudskipper, African catfish, oriental weatherloach, swamp eel, four-eyed sleeper, abehaze and slender African lungfish), which can tolerate high environmental ammonia exposure, are used as examples to demonstrate how eight different adaptations can be involved in defence against ammonia toxicity. Four of these adaptations deal with ammonia toxicity at branchial and/or epithelial surfaces: (1) active excretion of NH(4)(+); (2) lowering of environmental pH; (3) low NH(3) permeability of epithelial surfaces; and (4) volatilization of NH(3), while another four adaptations ameliorate ammonia toxicity at the cellular and subcellular levels: (5) high tolerance of ammonia at the cellular and subcellular levels; (6) reduction in ammonia production; (7) glutamine synthesis; and (8) urea synthesis. The responses of tropical air-breathing fishes to high environmental ammonia are determined apparently by behavioural adaptations and the nature of their natural environments. PMID:15316728

  10. Radiation damage effects in polarized deuterated ammonia

    SciTech Connect

    P.M. McKee

    2003-07-01

    Solid polarized targets utilizing deuterated ammonia, {sup 15}ND{sub 3}, offer an attractive combination of high polarization, high dilution factor and high resistance to polarization losses from radiation damage. Jefferson Laboratory Experiment E93-026 used {sup 15}ND{sub 3} as a target material in a five-month form factor measurement, allowing a detailed study of it's performance. The dependence of the deuteron polarization on received dose by the ammonia and the effectiveness of annealing the material to recover performance lost to radiation damage will be discussed.

  11. Modeling ammonia removal in aerated facultative lagoons.

    PubMed

    Houweling, C D; Kharoune, L; Escalas, A; Comeau, Y

    2005-01-01

    A mechanistic model has been developed to model ammonia removal in aerated facultative lagoons. Flow is modeled through the water column by a continuously stirred tank reactor and exchanges between the sludge layer and the water column are simulated by a solids separator. The biological model is based on an activated sludge model with reactions added for anaerobic bacterial growth and degradation of inert organic material. Results show that the model is able to predict seasonal variation in ammonia removal as well as sludge accumulation in the lagoons. PMID:16114676

  12. Retrofits: A Means for Reducing Energy Consumption in Ammonia Manufacture

    E-print Network

    LeBlanc, J. R.; Moore, D. O.; Schneider, R. V., III

    1982-01-01

    on catalytic reforming of hydrocarbons with steam to produce raw synthesis gas. This gas is further processed in carbon monoxide shift converters and purified to form ammonia synthesis gas, which is converted to ammonia. The plant described herein is based... on an ammonia production rate of 1000 STPD using natural gas feed. The process is divided into the following three sections with utilities included as an additional section: Reforming and shift C02 removal and methanation Compression and ammonia synthesis...

  13. Diffusion of ammonia gas in PDMS characterized by ATR spectroscopy

    NASA Astrophysics Data System (ADS)

    Levinský, Petr; Kalvoda, Ladislav; Aubrecht, Jan; Fojtíková, Jaroslava

    2015-01-01

    The kinetic parameters of a chemo-optical transducer layer sensitive to gaseous ammonia are characterized by means of attenuation total reflection method. The tested layer consists of cross-linked polydimethylsiloxane matrix sensitized by quinoline-based organometallic dye showing the selective chemical reaction with ammonia. Upper and lower limits of the ammonia diffusion coefficient and the ammonia-dye reaction constant are derived from the obtained experimental data and compared with other data available in literature and obtained from computer simulations.

  14. Polymer recycling: opportunities and limitations.

    PubMed Central

    Stein, R S

    1992-01-01

    The disposal of polymer solid waste by means other than landfilling is necessary. The various approaches-source reduction, incineration, degradation, composting, and recycling-all have their roles and must be employed in an integrated manner. Where appropriate, recycling has ecological advantages, but its application is dependent upon the feasibility of collection, sorting, and/or compatibilization of resulting mixtures to produce economically viable products. The practice should be encouraged by societal or legislative pressure which recognizes that the cost of disposal should be a factor in determining the cost of a product. PMID:11607263

  15. RecycleMania! Improving Waste Reduction and Recycling on

    E-print Network

    Awtar, Shorya

    champion-to-employee ratio Large amount of space Information overload Variety of audiences Top;Unique Challenges Large amount of space More recycling resources needed More area to cover with outreach on the same methods of information sharing for all topics People become blind & deaf to these and filter out

  16. Recycled Unbound Base Pooled Fund Study

    E-print Network

    Minnesota, University of

    Geological Engineering Program University of Wisconsin-Madison #12;·! Recycled Concrete Aggregate (RCARecycled Unbound Base Pooled Fund Study Tuncer B. Edil Recycled Materials Resource Center) ­! Demolition and reprocessing of existing concrete structures (buildings, roads, runways, etc.) ­! Produced

  17. 40 CFR 141.76 - Recycle provisions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... NATIONAL PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.76 Recycle provisions...All subpart H systems that employ conventional filtration or direct filtration treatment and that recycle spent filter...

  18. 40 CFR 141.76 - Recycle provisions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... NATIONAL PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.76 Recycle provisions...All subpart H systems that employ conventional filtration or direct filtration treatment and that recycle spent filter...

  19. 40 CFR 141.76 - Recycle provisions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... NATIONAL PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.76 Recycle provisions...All subpart H systems that employ conventional filtration or direct filtration treatment and that recycle spent filter...

  20. 40 CFR 141.76 - Recycle provisions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... NATIONAL PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.76 Recycle provisions...All subpart H systems that employ conventional filtration or direct filtration treatment and that recycle spent filter...

  1. 40 CFR 141.76 - Recycle provisions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... NATIONAL PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.76 Recycle provisions...All subpart H systems that employ conventional filtration or direct filtration treatment and that recycle spent filter...

  2. Compositional evaluation of asphalt binder recycling agents 

    E-print Network

    Madrid, Richard Charles

    1997-01-01

    Several experiments were performed to determine how recycling agent composition affects the high, intermediate, and low temperature properties as well as long term oxidative aging characteristics of recycled asphalt blends. Specifically, several...

  3. Residential Refrigerator Recycling Ninth Year Retention Study

    E-print Network

    Residential Refrigerator Recycling Ninth Year Retention Study Study ID Nos. 546B, 563 Prepared RECYCLING PROGRAMS Study ID Nos. 546B and 563 Prepared for Southern California Edison Rosemead, California

  4. Recycling of used perfluorosulfonic acid membranes

    DOEpatents

    Grot, Stephen (Middletown, DE); Grot, Walther (Chadds Ford, PA)

    2007-08-14

    A method for recovering and recycling catalyst coated fuel cell membranes includes dissolving the used membranes in water and solvent, heating the dissolved membranes under pressure and separating the components. Active membranes are produced from the recycled materials.

  5. Compositional evaluation of asphalt binder recycling agents

    E-print Network

    Madrid, Richard Charles

    1997-01-01

    Several experiments were performed to determine how recycling agent composition affects the high, intermediate, and low temperature properties as well as long term oxidative aging characteristics of recycled asphalt blends. Specifically, several...

  6. Food Service Recycling: Whose Responsibility Is It?

    ERIC Educational Resources Information Center

    Settanni, Barbara

    1990-01-01

    The food service department at a Pennsylvania school district recycles polystyrene "styrofoam" cups, plates, and food trays. In addition, the department recycles glass, aluminum, and paper. Offers advice on how to set up a school program. (MLF)

  7. Ammonia as a polarized solid target material—a review

    Microsoft Academic Search

    W. Meyer

    2004-01-01

    The enormous efforts towards dynamically polarized ammonia and deuterated ammonia (d-ammonia) with their reasonable high polarizable nucleon contents (quality factor) are reviewed. The early attempts are also a story of failures until a radiation doping method for NH3 was successfully demonstrated in the end of the 1970s. Some years later the outcome of intense studies and new developments (with pitfalls,

  8. Ammonia excretion during feeding and starvation in Octopus vulgaris

    Microsoft Academic Search

    R. Boucher-Rodoni; K. Mangold

    1985-01-01

    Ammonia excretion was investigated in relation to oxygen consumption during a feeding regime and during shortterm starvation in two mature male Octopus vulgaris, trawled in spring 1983 off Banyuls-sur-mer. In our study, ammonia excretion is taken to include renal and gill loss. The excretion of primary amines was also studied, but proved to be negligible under our experimental conditions. Ammonia

  9. Comparison of ammonia emissions determined using different sampling methods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dynamic, flow-through flux chambers are sometimes used to estimate ammonia emissions from livestock operations; however, ammonia emissions from the surfaces are affected by many factors which can be affected by the chamber. Ammonia emissions estimated using environmental flow-through chambers may be...

  10. Effect of atmospheric ammonia on pullets at point of lay

    SciTech Connect

    Deaton, J.W.; Reece, F.N.; Lott, B.D.

    1984-02-01

    Results obtained show that pullets exposed to 200 ppm atmospheric ammonia for 17 days had a reduced feed intake and reduced growth rate when compared to controls. After the ammonia exposure period at point of lay, percent egg production was less and mortality greater for the ammonia exposed group versus the controls.

  11. MANAGEMENT OPTIONS FOR REDUCING AMMONIA EMISSIONS FROM POULTRY LITTER

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ammonia emissions from poultry litter not only result in air pollution; high levels of ammonia in poultry houses cause poor bird performance, increase the susceptibility of birds to viral diseases, and negatively impact human health. Although ammonia emissions are a concern, few cost-effective best ...

  12. Pentacene-Based Organic Thin Film Transistors for Ammonia Sensing

    Microsoft Academic Search

    Hsiao-Wen Zan; Wu-Wei Tsai; Yen-ren Lo; Yu-Mei Wu; Yuh-Shyong Yang

    2012-01-01

    Non-invasive ammonia sensors are attractive alternatives for the diagnoses of a variety of chronic diseases such as liver cirrhosis and renal failure. A low cost pentacene-based organic thin film transistor (OTFT) fabricated by a novel and simple process was demonstrated to be highly sensitive and specific for ammonia gas. Various measurement parameters that reflected OTFT device characteristics for ammonia detection

  13. Ammonia removal and recovery from urea fertilizer plant waste

    Microsoft Academic Search

    Vijay K. Minocha; A. V. S Prabhakar Rao

    1988-01-01

    Air stripping is the most simple method of ammonia removal from fertilizer wastewaters. Herein, studies were carried out for the removal and recovery of ammonia. With experimental data, a nomogram was generated relating the three contrblable variables, namely waste?water flow rate, air flow rate and percentage ammonia removal. It was found that one litre of commercially available raw grade phosphoric

  14. The Ammonia Smoke Fountain: An Interesting Thermodynamic Adventure.

    ERIC Educational Resources Information Center

    Alexander, M. Dale

    1999-01-01

    Describes a new demonstration that uses an apparatus like the ammonia-fountain apparatus but with modifications designed to produce ammonium-chloride smoke. This demonstration is easy to perform, interesting to observe, and allows demonstration of the solubility of ammonia in water, the basic nature of ammonia, the acidic nature of hydrogen…

  15. Ammonia as a fuel in solid oxide fuel cells

    Microsoft Academic Search

    Adam Wojcik; Hugh Middleton; Ioannis Damopoulos; Jan Van herle

    2003-01-01

    The use of ammonia as a source of hydrogen for fuel cells has received little attention until now. Ammonia offers several advantages over hydrogen as a fuel and is produced commercially in massive quantities and as a biogas. This paper describes the results of a solid oxide fuel cell-based system running on ammonia and compares the performance with respect to

  16. Original article Ammonia treatment of lucerne and cocksfoot

    E-print Network

    Paris-Sud XI, Université de

    Original article Ammonia treatment of lucerne and cocksfoot harvested at two growth stages: Effect cell wall on inhibition of digestibility. Ammonia treat- ment significantly increased the nitrogen by ammonia was low, composed mainly of polyuronic acids, which are highly digestible. In cocksfoot

  17. Borane-Ammonia Complexes Stabilized by Hydrogen Bonding

    E-print Network

    Trauner, Dirk

    Borane-Ammonia Complexes Stabilized by Hydrogen Bonding Chambers C. Hughes, Dirk Scharn, Johann Vienna, Austria trauner@cchem.berkeley.edu Received September 6, 2002 ABSTRACT Novel boron-ammonia amines or ammonia have been reported. In 1992, Reetz et al. described borane-amine complexes of type 1

  18. Influence of amount of recycled coarse aggregates and production process on properties of recycled aggregate concrete

    Microsoft Academic Search

    M. Etxeberria; E. Vázquez; A. Marí; M. Barra

    2007-01-01

    In this study recycled coarse aggregates obtained by crushed concrete were used for concrete production. Four different recycled aggregate concretes were produced; made with 0%, 25%, 50% and 100% of recycled coarse aggregates, respectively. The mix proportions of the four concretes were designed in order to achieve the same compressive strengths. Recycled aggregates were used in wet condition, but not

  19. Recycling at Penn State's Beaver Stadium. "Recycle on the Go" Success Story

    ERIC Educational Resources Information Center

    US Environmental Protection Agency, 2009

    2009-01-01

    With a 13-year-old recycling program, The Pennsylvania State University's (Penn State) Beaver Stadium in the past diverted nearly 30 tons of recyclables per year from local landfills. A new initiative to promote recycling in the stadium's tailgating area has helped Penn State more than triple its old recycling record, collecting 112 tons in 2008.…

  20. What Makes a Recycler?A Comparison of Recyclers and Nonrecyclers

    Microsoft Academic Search

    Joanne Vining; Angela Ebreo

    1990-01-01

    Knowledge and motivational factors represent important but neglected topics in the study of recycling behavior. This article examines differences in knowledge, motives, and demographic characteristics of people who have the opportunity to recycle voluntarily. Information on these variables was obtained for 197 households in Illinois. The results indicated that recyclers in general were more aware of publicity about recycling and

  1. Waste Management and Recycling in Lab Batteries can be recycled in the VWR stockroom

    E-print Network

    Cohen, Robert E.

    Waste Management and Recycling in Lab · Batteries can be recycled in the VWR stockroom · Electronic material can be recycled for free by MIT facilities (via SAP web) · Bulk equipment can be disposed be placed in recycling bin ­ Cardboard ­ Please break down and flatten boxes ­ Containers (aluminum, metal

  2. Where can I recycle it year-round? Item Local Recycling Locations

    E-print Network

    Escher, Christine

    Where can I recycle it year-round? Item Local Recycling Locations Styrofoam First Alternative Co-op Recycling Center, 1007 SE 3rd St., 541-753-3115 (small fee) Packing Peanuts OSU Surplus, 644 SW 13 th St., 541-737-7347 Commercial shipping stores Film Plastics First Alternative Co-op Recycling Center, 1007

  3. Research Report Recycling gone bad: When the option to recycle increases

    E-print Network

    Loudon, Catherine

    Research Report Recycling gone bad: When the option to recycle increases resource consumption Jesse Abstract In this study, we propose that the ability to recycle may lead to increased resource usage compared to when a recycling option is not available. Supporting this hypothesis, our first experiment

  4. Proceedings of the waste recycling workshop

    SciTech Connect

    Bailey, R.E.; Thomas, A.F.; Ries, M.A. [eds.] [Ohio State Univ., Columbus, OH (United States)] [eds.; Ohio State Univ., Columbus, OH (United States)

    1993-12-31

    Recorded are seventeen talks from five sessions at the workshop. FERMCO`s recycling program, state of the art recycling technology, and an integrated demonstration of deactivation, decommissioning and decommissioning are presented in the plenary session. In the concrete session, decontamination and recycling are discussed. In the transite session, regulations are considered along with recycling and decontamination. In the metals session, radioactive scrap metals are emphasized. And in the regulatory considerations and liabilities session, DOE and EPA viewpoints are discussed. (GHH)

  5. Recycling in Schools: From Fad to Business.

    ERIC Educational Resources Information Center

    Porter, J. Winston

    1991-01-01

    Numerous business issues arise when organizing a school recycling program. Important questions include the appropriate program organization, deciding what materials to recycle, the selection of appropriate business partners, and various financial issues. Offers suggestions for achieving a successful recycling program. (MLF)

  6. Phosphate recycling in the phosphorus industry

    Microsoft Academic Search

    W. J. Schipper; A. Klapwijk; A. Potjer; W. H. Rulkens; B. G. Temmink; F. D. G. Kiestra; A. C. M. Lijmbach

    2001-01-01

    The feasibility of phosphate recycling in the white phosphorus production process is discussed. Several types of materials may be recycled, provided they are dry inorganic materials, low in iron, copper and zinc. Sewage sludge ash may be used if no iron is used for phosphate precipitation in the treatment plant; using Ca or Al, or bio-P-removal, increases the recycling potential

  7. Properties of HPC with recycled aggregates

    Microsoft Academic Search

    Tsung-Yueh Tu; Yuen-Yuen Chen; Chao-Lung Hwang

    2006-01-01

    The utilization of recycled aggregates can minimize environmental impact and slow the huge consumption of natural resources used for concrete applications. However, recycled aggregates are not suitable for use in the production of High Performance Concrete (HPC) due to their relatively high absorption capacity, unstable properties and recycled aggregates' weaker strength. Such inadequacies can be overcome through carefully examining the

  8. Recycling Report FY2012 FY2012

    E-print Network

    Mohanty, Saraju P.

    FY 2013 Recycling Report FY2012 FY2012 Month Tons Revenue Tons Revenue Lbs Revenue Tons Revenue Saved 2,987 Gallons of Water Conserved 1,230,411 Paper Cardboard Aluminum Plastic Misc (Tin, Copper, Scrap) RESOURCES SAVED BY RECYCLING Total Tons Recycled 175.77 Cubic Feet of Landfill Space Conserved 15

  9. Recycled Materials Resource Jeffrey S. Melton

    E-print Network

    projects completed to date Project 1: Mitigating Alkali Silicate Reaction in Recycled Concrete Project 2: Using Lithium to Mitigate ASR in RCA Concrete Project 38: Recycled Concrete Aggregate Concrete Pavement Reaction (ASR) in Recycled Concrete Partners: Penn DOT, Maine DOT, Wyoming DOT, FMC Lithium Corporation

  10. Use of building rubbles as recycled aggregates

    Microsoft Academic Search

    How-Ji Chen; Tsong Yen; Kuan-Hung Chen

    2003-01-01

    The application of building rubble collected from damaged and demolished structures is an important issue in every country. After crushing and screening, this material could serve as recycled aggregate in concrete. A series of experiments using recycled aggregate of various compositions from building rubble was conducted. The test results show that the building rubble could be transformed into useful recycled

  11. Creep and shrinkage of recycled aggregate concrete

    Microsoft Academic Search

    A. Domingo-Cabo; C. Lázaro; F. López-Gayarre; M. A. Serrano-López; P. Serna; J. O. Castaño-Tabares

    2009-01-01

    This paper presents the results of experimental research into concrete produced by replacing the natural aggregates with recycled aggregates coming from construction waste and concrete work demolitions. The main aim of this work was to determine creep and shrinkage variations experienced in recycled concrete, made by replacing the main fraction of the natural aggregate with a recycled aggregate coming from

  12. Ames Lab 101: Rare-Earth Recycling

    SciTech Connect

    Ryan Ott

    2012-09-05

    Recycling keeps paper, plastics, and even jeans out of landfills. Could recycling rare-earth magnets do the same? Perhaps, if the recycling process can be improved. Scientists at the U.S. Department of Energy's Ames Laboratory are working to more effectively remove the neodymium, a rare earth, from the mix of other materials in a magnet.

  13. Ames Lab 101: Rare-Earth Recycling

    ScienceCinema

    Ryan Ott

    2013-06-05

    Recycling keeps paper, plastics, and even jeans out of landfills. Could recycling rare-earth magnets do the same? Perhaps, if the recycling process can be improved. Scientists at the U.S. Department of Energy's Ames Laboratory are working to more effectively remove the neodymium, a rare earth, from the mix of other materials in a magnet.

  14. Acceleration of landfill stabilization using leachate recycle

    Microsoft Academic Search

    T. G. Townsend; W. L. Miller; Hyung-Jib Lee; J. F. K. Earle

    1996-01-01

    A leachate recycle system was constructed and operated at an existing lined landfill in North-Central Florida to observe the effects of leachate recycle on landfill stabilization. Samples of leachate, landfill gas, and landfilled solid waste were collected and analyzed throughout a four-year period, before and after the start of leachate recycle. The settlement of landfilled waste was also measured in

  15. Textile Recycling, Convenience, and the Older Adult.

    ERIC Educational Resources Information Center

    Domina, Tanya; Koch, Kathryn

    2001-01-01

    Results of a study to examine the recycling practices and needs of older adults (n=217) indicated that older adults do recycle traditional materials, but need accommodations for physical limitations. They report textile recycling as time consuming and difficult and used donations to religious organizations as their principal means of textile…

  16. Material Recycling and Waste Disposal Document Control

    E-print Network

    Guillas, Serge

    1 Material Recycling and Waste Disposal Procedure Document Control Document Created by 23, treatment, handling, transport and disposal of recyclable materials and residual wastes so as to maximise the opportunity and value for the recyclable materials and to minimise the quantity of residual materials

  17. ENVIRONMENTAL PROTECTION FOR THE AUTOMOBILE RECYCLING INDUSTRY

    E-print Network

    #12;ENVIRONMENTAL PROTECTION FOR THE AUTOMOBILE RECYCLING INDUSTRY IN BRITISH COLUMBIA Volume 1 Pollution Abatement Office. Funds were also provided by BC Auto Recyclers, the BC Ministry of Environment 224 West Esplanade North Vancouver, B.C. Vm3H7 #12;BEST MANAGEMENT PRACTICES FOR THE AUTO RECYCLING

  18. Recycling at Mooov-In 2011

    E-print Network

    Julien, Christine

    Cardboard Recycling at Mooov-In 2011 For the second year in a row, Division of Housing and Food Service (DHFS) and Recycling & Sustainability teamed up to divert as much cardboard as possible from area landfills. In addition to the paper, cardboard, aluminum and plastic recycling available in all residence

  19. Campus Recycling: Everyone Plays a Part.

    ERIC Educational Resources Information Center

    Ching, Raymond; Grogan, Robert

    1992-01-01

    The broad appeal of recycling makes it the most widespread and popular campus environmental activity. Recycling programs have a wide variety of designs and can fit into an overall waste management strategy, but effective planning for campus recycling requires awareness of a variety of issues and needs. (Author/MSE)

  20. Communication and Recycling in Park Campgrounds.

    ERIC Educational Resources Information Center

    Ham, Sam H.

    1984-01-01

    Evaluated the effectiveness of the Canby Washington State Park campground recycling program by determining whether campers (N=147) read and followed the provided instructions when disposing of garbage, understood the sorting and disposal instructions, and arrived at the park equipped with receptacles for recyclables and non-recyclables.…

  1. Really Recycled-SeaWorld Classroom Activity

    NSDL National Science Digital Library

    Sea World - Just for Teachers

    2012-04-03

    In this activity, students will be able to recycle newspaper into their own conservation message. Students will also be given the opportunity to write about their experience with recycling or persuade the reader why it is important to recycle based on what they learned in the activity.

  2. 78 FR 69531 - America Recycles Day, 2013

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-19

    ...schools, let us strive to make recycling a part of our daily lives. We should reuse or donate when possible, and recycle or compost as much as we are able. Students can get involved by championing waste-free lunches, recycling programs, and...

  3. RECYCLE TO EARN Rishi Bhailal Chandra

    E-print Network

    Zhou, Yaoqi

    RECYCLE TO EARN Rishi Bhailal Chandra Supply Chain Management, Accounting, Kelley School of Business, IUPUI Recycling is a key aspect of any sustainability effort, one that calls for the participation of the entire campus community. Getting students to recycle is very difficult. Students lack

  4. The status of recycling of waste rubber

    Microsoft Academic Search

    Yi Fang; Maosheng Zhan; Ying Wang

    2001-01-01

    The significance of recycling of waste rubber in protecting the environment and conserving energy is discussed. Various kinds of recycling approaches to waste rubber are summed up, such as reclaiming energy as fuel, reuse of the products of thermal decomposition, cleaning of leaking oil, reuse after simple modification, regenerative rubber and powdered rubber (PR). Recycling as PR is covered in

  5. Toward a Rationale for Recycling in Schools.

    ERIC Educational Resources Information Center

    Cherif, Abour H.

    1995-01-01

    Encourages educators to design new strategies to incorporate a range of options that include teaching recycling and waste management in schools to ensure recycling behavior and more participation in waste management. States that more education will make the difference and that recycling should be a part of the school curriculum. Lists major…

  6. Recycling and reuse of industrial wastes

    Microsoft Academic Search

    L. Smith; J. Means; E. Barth

    1995-01-01

    The handbook assists pollution prevention efforts by encouraging recycling and reuse of wastes found on Superfund or Resource Conservation and Recovery Act (RCRA) Corrective Action sites. It outlines specific technologies for recycling and reuse of materials that require remediation at contaminated sites. Case studies document applications of these technologies to real-world conditions. Site and waste type, technology application, recycling benefits,

  7. Percolation effects on entangled polymer rheology and the glass transition

    NASA Astrophysics Data System (ADS)

    Wool, Richard P.

    2012-07-01

    Current thinking on the fundamentals of entangled polymer melt rheology suggests that stress relaxation in the terminal zone occurs via Reptation, chain-end fluctuation and (convective) constraint release. This scenario is not correct. It is shown through a series of experiments with selectively deuterated model polymers that relaxation occurs through a percolation process which permits large clusters of entangled polymers to stress relax before their conformations are fully relaxed. The percolation model of entanglements (R.P. Wool, Macromolecules 26, 1564, 1993) makes unique predictions regarding the dynamics of polymer chains in the terminal relaxation zone. These include: (a) Reptating homopolymer chains with molecular weight M >> Mc appear to be non-Reptating as their ends and centers relax at the same rate in a Rouse-like manner during percolation. (b) The mechanical relaxation time ?(M) is related to the Reptation time Tr˜ M3 by ?(M) = Tr[(1-Mc/M)Me/Mc]2, which is the origin of the zero shear viscosity behaving as ?o˜M3.4 (c) The biggest surprise is that during stress relaxation, the random coil dimensions Rg(//) and Rg(?) are not fully relaxed when the stress and birefringence relax to zero. (d) Matrix molecular weight P effects on relaxation time ?(M) of the probe chain M are as follows: When the probe chain M>>P, the matrix P-chains percolate and Rouse-like dynamics is observed for the M-Reptating chains with ?(M) ˜ P1M2. (e) When the matrix P>>M, percolation does not occur for the M-chain and the relaxation time of the probe chain ?(M) ˜ PoM3 is in accord with DeGennes Reptation theory. These unusual results predicted by entanglement percolation are supported by extensive experimental data (NR, SANS, DSIMS, FTIR, BR) from selectively deuterated polystyrene chains HDH, DHD, HPS and DPS. These results clearly suggest that current notions of polymer rheology need to be reconsidered. Near Tg, a new perspective on the Glass Transition of amorphous materials is offered by the Twinkling Fractal Theory (TFT). [R. P. Wool, J. Polym. Sci, Part B: Polym Phys. 46, 2765 (2008)]. TFT applications to entangled polymers include: (a) rate dependence of dynamical mechanical properties, particularly the tan delta damping peak used to measure Tg, (b) derivation of the empirical WLF and Vogel Fulcher time-temperature superposition empirical relation, (c) Physical Aging and (d) Nanoconfinement.

  8. Vermitechnology for sewage sludge recycling

    Microsoft Academic Search

    Meena Khwairakpam; Renu Bhargava

    2009-01-01

    The present paper is aimed at safe reuse and recycling of sewage sludge (SS) and production of good quality compost using vermicomposting. Three different earthworm species Eiseniafetida (E. fetida), Eudrilus eugeniae (E. eugeniae), Perionyx excavatus (P. excavatus) in individual and combinations were utilized to compare the suitability of worm species for composting of sewage sludge as well as the quality

  9. Particle recycling in volcanic plumes

    Microsoft Academic Search

    Graham Veitch; Andrew W. Woods

    2002-01-01

    We have developed a new theoretical model of an eruption column that accounts for the re-entrainment of particles as they fall out of the laterally spreading umbrella cloud. The model illustrates how the mass flux of particles in the plume may increase with height in the plume, by a factor as large as 2.5 because of this recycling. Three important

  10. Chemical solutions for greywater recycling

    Microsoft Academic Search

    Marc Pidou; Lisa Avery; Tom Stephenson; Paul Jeffrey; Simon A. Parsons; Shuming Liu; Fayyaz A. Memon; Bruce Jefferson

    2008-01-01

    Greywater recycling is now accepted as a sustainable solution to the general increase of the fresh water demand, water shortages and for environment protection. However, the majority of the suggested treatments are biological and such technologies can be affected, especially at small scale, by the variability in strength and flow of the greywater and potential shock loading. This investigation presents

  11. Estimation of continental precipitation recycling

    Microsoft Academic Search

    Kaye L. Brubaker; Dara Entekhabi; P. S. Eagleson

    1993-01-01

    The total amount of water that precipitates on large continental regions is supplied by two mechanisms: (1) advection from the surrounding areas external to the region and (2) evaporation and transpiration from the land surface within the region. The latter supply mechanism is tantamount to the recycling of precipitation over the Continental area. The degree to which regional precipitation is

  12. Household-battery recycling plant

    SciTech Connect

    Weber, A.; Antenen, A. [Batrec Technology A.G., Dietikon (Switzerland)

    1995-12-31

    Batrec operates a plant for the recycling of used dry batteries with a capacity of 3,000 tons per year. The plant is situated in a tourist area of Switzerland and has complied with all the strict emission restrictions. The process yields four products: FeMn, Zn, Hg and slag. No hazardous waste is produced. All types of batteries can be treated.

  13. Recycling of plastics in Germany

    Microsoft Academic Search

    Martin Patel; Norbert von Thienen; Eberhard Jochem; Ernst Worrell

    2000-01-01

    This article deals with the waste management of post-consumer plastics in Germany and its potential to save fossil fuels and reduce CO2 emissions. Since most of the experience available is for packaging the paper first gives an outline of the legislative background and the material flows for this sector. The recycling and recovery processes for plastics waste from all sectors

  14. New Pathways in Plastics Recycling.

    PubMed

    Kaminsky; Hartmann

    2000-01-01

    The catalytic degradation of polyethylene to short-chain hydrocarbons is possible with zirconium hydride compounds (see picture), and represents the first step in the reversal of Ziegler - Natta polymerization. Thus, even in the case of polyolefins the important target of plastics recycling, the recovery of reusable monomers from polymer waste, may be achieved. PMID:10649399

  15. Authorization recycling in RBAC systems

    Microsoft Academic Search

    Qiang Wei; Jason Crampton; Konstantin Beznosov; Matei Ripeanu

    2008-01-01

    As distributed applications increase in size and complexity, tradi- tional authorization mechanisms based on a single policy decision point are increasingly fragile because this decision point represents a single point of failure and a performance bottleneck. Authoriza- tion recycling is one technique that has been used to address these challenges. This paper introduces and evaluates the mechanisms for autho- rization

  16. LUBRICATING THE RECYCLING MACHINE 2

    Microsoft Academic Search

    Rutger Gyllenram; Sven Ekerot; Pär Jönsson

    2008-01-01

    When introducing a new control paradigm in industry or society you have to accept that it is an evolutionary process where people, methods and processes must develop simultaneously. This takes time. The recycling of materials has been studied intensely for the last ten years using different approaches to material flow analyses, MFAs. They have provided a good view of the

  17. Recycled Yo-Yo Challenge

    NSDL National Science Digital Library

    2012-06-26

    In this activity, learners are challenged to build their own yo-yo toys using items found in their recycling bins. Learners search for materials to use for each part of the toy: two discs, an axle, and string. Learners then sketch their invention, assemble the parts, and test it out. Learners are encouraged to tweak their yo-yos and make improvements.

  18. Chemical recycling of scrap composites

    NASA Technical Reports Server (NTRS)

    Allred, Ronald E.; Salas, Richard M.

    1994-01-01

    There are no well-developed technologies for recycling composite materials other than grinding to produce fillers. New approaches are needed to reclaim these valuable resources. Chemical or tertiary recycling, conversion of polymers into low molecular weight hydrocarbons for reuse as chemicals or fuels, is emerging as the most practical means for obtaining value from waste plastics and composites. Adherent Technologies is exploring a low-temperature catalytic process for recycling plastics and composites. Laboratory results show that all types of plastics, thermosets as well as thermoplastics, can be converted in high yields to valuable hydrocarbon products. This novel catalytic process runs at 200 C, conversion times are rapid, the process is closed and, thus, nonpolluting, and no highly toxic gas or liquid products have been observed so no negative environmental impact will result from its implementation. Tests on reclamation of composite materials show that epoxy, imide, and engineering thermoplastic matrices can be converted to low molecular weight hydrocarbons leaving behind the reinforcing fibers for reuse as composite reinforcements in secondary, lower-performance applications. Chemical recycling is also a means to dispose of sensitive or classified organic materials without incineration and provides a means to eliminate or reduce mixed hazardous wastes containing organic materials.

  19. Tin oxide nanocluster hydrogen and ammonia sensors

    Microsoft Academic Search

    A Lassesson; M Schulze; J van Lith; S A Brown

    2008-01-01

    We have prepared sensitive hydrogen and ammonia sensors from thin films of tin nanoclusters with diameters between 3 and 10 nm. By baking the samples at 200 °C in ambient air the clusters were oxidized, resulting in very stable films of tin oxide clusters with similar diameters to the original Sn clusters. By monitoring the electrical resistance, it is shown

  20. Ammonia - It's Transformation and Effective Utilization

    Microsoft Academic Search

    Henry Brandhorst; Martin Baltazar-Lopez; Bruce Tatarchuk; Donald R. Cahela; Troy Barron

    2008-01-01

    In practical use, ammonia (NH3) can be burned directly in internal combustion (IC), diesel or Stirling engines. However, because NH3 has such a low flame temperature and is hard to ignite, it has generally not been widely used in these applications. Because NH3 can be easily reformed into hydrogen (H2), and as part of the effort to examine the benefits

  1. OPTIMIZED CHEMILUMINESCENCE SYSTEM FOR MEASURING ATMOSPHERIC AMMONIA

    EPA Science Inventory

    The optimization and testing of a continuous measurement system for analyzing atmospheric ammonia concentrations (0 to 10 ppb) is described. The measurement system combines an ultra-sensitive chemiluminescence nitric oxide detector, with a thermal converter for NH3 to nitric oxid...

  2. Hydrolysis of hydrogen cyanide in ammonia liquors

    SciTech Connect

    Kamennykh, B.M.; Nazarov, V.G.; Rus'yanova, N.D.; Lebedeva, G.N.

    1983-01-01

    A thermodynamic analysis was performed on the conversion of hydrocyanic acid to anhydrous ammonia in concentrated ammonia liquors obtained from overall purification schemes used for coke oven gas. The temperature range of treatment (90 to 140/sup 0/C) was chosen in view of the standard low pressure (to 588 kPa) available for the process, and with consideration for the industrial liquor regeneration regime. Samples were collected while retaining the liquor in the reactor without agitation at a constant temperature. Changes in the HCN concentration as a function of retention time are described by logarithmic functions. An effective rate constant was calculated. Results show that in comprehensive schemes for gas treatment by cyclic methods with production of anhydrous ammonia and with ammonia, sulfur and cyanide removal, the principal part of the HCN extracted from the gas in the regneration of the wash liquors and treatment of the NH/sub 3/ liquors will be hydrolyzed at high temperature, and the hydrolysis products will be removed. 4 figures, 1 table.

  3. Ammonia release method for depositing metal oxides

    DOEpatents

    Silver, Gary L. (Centerville, OH); Martin, Frank S. (Farmersville, OH)

    1994-12-13

    A method of depositing metal oxides on substrates which is indifferent to the electrochemical properties of the substrates and which comprises forming ammine complexes containing metal ions and thereafter effecting removal of ammonia from the ammine complexes so as to permit slow precipitation and deposition of metal oxide on the substrates.

  4. Adsorption of Ammonia on Regenerable Carbon Sorbents

    NASA Technical Reports Server (NTRS)

    Wójtowicz, Marek A.; Cosgrove, Jesph E.; Serio, Michael A..; Wilburn, Monique

    2015-01-01

    Results are presented on the development of reversible sorbents for the combined carbon dioxide, moisture, and trace-contaminant (TC) removal for use in Extravehicular Activities (EVAs), and more specifically in the Primary Life Support System (PLSS). The currently available life support systems use separate units for carbon dioxide, trace contaminants, and moisture control, and the long-term objective is to replace the above three modules with a single one. Data on sorption and desorption of ammonia, which is a major TC of concern, are presented in this paper. The current TC-control technology involves the use of a packed bed of acid-impregnated granular charcoal, which is non-regenerable, and the carbon-based sorbent under development in this project can be regenerated by exposure to vacuum at room temperature. In this study, several carbon sorbents were fabricated and tested for ammonia sorption. Ammonia-sorption capacity was related to carbon pore structure characteristics, and the temperature of oxidative carbon-surface treatment was optimized for enhanced ammonia-sorption performance.

  5. Broiler cake potential to emit ammonia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spatial differences for ammonia (NH3) flux from litter are evident within broiler houses especially when considering friable litter and caked surfaces. The objectives of this study were to quantify NH3 generation potential between different sources of cake (two separate farms having variable length...

  6. Effect of ammonia on Swiss albino mice

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Casey, C. J.; Furst, A.

    1977-01-01

    Times to incapacitation and death and LC /50/ values were determined for Swiss albino male mice exposed to different concentrations of ammonia in a 4.2 liter hemispherical chamber. The LC/50/ for a 30 minute exposure was 21,430 ppm.

  7. Subsurface manure application to reduce ammonia emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Incorporation into soil is generally recommended to reduce ammonia volatilization and nutrient runoff following land application of manures. A range of subsurface applicators are available for manure incorporation with minimal soil disturbance in reduced tillage systems, but none have been widely a...

  8. Laser-Based Pulsed Photoacoustic Ammonia Detection

    NASA Astrophysics Data System (ADS)

    Vallespi, Arturo; Slezak, Verónica; Peuriot, Alejandro; Santiago, Guillermo

    2013-09-01

    Detecting ammonia traces is relevant in health, manufacturing, and security areas, among others. As ammonia presents a strong absorption band (the mode) around 10 m, some of the physical properties which may influence its detection by means of pulsed photoacoustic (PA) spectroscopy with a TEA laser have been studied. The characteristics of the ammonia molecule and the laser intensity may result in a nonlinear dependence of the PA signal amplitude on the laser fluence. Ammonia absorption can be described as a simple two-level system with power broadening. As is a polar molecule, it strongly undergoes adsorption phenomena in contact with different surfaces. Therefore, physical adsorption-desorption at the cell’s wall is studied. A theoretical model, based on Langmuir’s assumptions, fits well to the experimental results with stainless steel. Related to these studies, measurements led to the conclusion that, at the used fluenced values, dissociation by multiphotonic absorption at the 10P(32) laser line may be discarded. A calibration of the system was performed, and a detection limit around 190 ppb (at 224 ) was achieved.

  9. Ammonia fuel cell with iridium catalyst

    Microsoft Academic Search

    D. W. McKee; A. J. Jr. Scarpellino

    1973-01-01

    The design of a hydrazine fuel cell using iridium or an iridium alloy as the anode catalyst is described. A heating means is provided whereby the ammonia vapor is dissociated into hydrogen and nitrogen. A wide variety of electrodes and electrolytes are suitable in the fuel cell.

  10. Ammonia in comet P/Halley

    NASA Technical Reports Server (NTRS)

    Meier, R.; Eberhardt, P.; Krankowsky, D.; Hodges, R. R.

    1994-01-01

    In comet P/Halley the abundances of ammonia relative to water reported in the literature differ by about one order of magnitude from roughly 0.1% up to 2%. Different observational techniques seem to have inherent systematic errors. Using the ion mass channels m/q = 19 amu/e, 18 amu/e and 17 amu/e of the Neutral Mass Spectrometer experiment aboard the spacecraft Giotto, we derive a production rate of ammonia of (1.5(sub -0.7)(sup +0.5))% relative to water. Inside the contact surface we can explain our data by a nuclear source only. The uncertainty in our abundance of ammonia is primarily a result of uncertainties in some key reaction coefficients. We discuss in detail these reactions and the range of error indicated results from extreme assumptions in the rate coefficients. From our data, even in the worst case, we can exclude the ammonia abundance to be only of the order of a few per mill.

  11. Self-protective cobalt nanocatalyst for long-time recycle application on hydrogen generation by its free metal-ion conversion

    NASA Astrophysics Data System (ADS)

    Wang, Zhi-Li; Yan, Jun-Min; Wang, Hong-Li; Jiang, Qing

    2013-12-01

    Cobalt nanoparticles have attracted much attention in nanocatalysis due to their low cost and high activities. However, the easy-oxidative deactivation of cobalt nanocatalysts in air seriously limits their practical applications, especially in a long-time recycle application. Herein, by intentionally taking advantage of the readily oxidizable character of metallic cobalt, we describe a simple but efficient method to overcome the above obstacle through a free and reverse metal-ion conversion of cobalt in air at room temperature. With this novel method, the cobalt nanocatalyst demonstrates the superior activity even after the long-time (73 days) recycle application for hydrogen generation from ammonia borane.

  12. AMMONIA CONCENTRATION IN SALTSTONE HEADSPACE SUMMARY REPORT

    SciTech Connect

    Zamecnik, J; Alex Cozzi, A

    2008-09-26

    The Saltstone Facility Documented Safety Analysis (DSA) is under revision to accommodate changes in the Composite Lower Flammability Limit (CLFL) from the introduction of Isopar into Tank 50. Saltstone samples were prepared with an 'MCU' type salt solution spiked with ammonia. The ammonia released from the saltstone was captured and analyzed. The ammonia concentration found in the headspace of samples maintained at 95 C and 1 atm was, to 95% confidence, less than or equal to 3.9 mg/L. Tank 50 is fed by several influent streams. The salt solution from Tank 50 is pumped to the salt feed tank (SFT) in the Saltstone Production Facility (SPF). The premix materials cement, slag and fly ash are blended together prior to transfer to the grout mixer. The premix is fed to the grout mixer in the SPF and the salt solution is incorporated into the premix in the grout mixer, yielding saltstone slurry. The saltstone slurry drops into a hopper and then is pumped to the vault. The Saltstone Facility Documented Safety Analysis (DSA) is under revision to accommodate changes in the Composite Lower Flammability Limit (CLFL) from the introduction of Isopar{reg_sign} L into Tank 50. Waste Solidification-Engineering requested that the Savannah River National Laboratory (SRNL) perform testing to characterize the release of ammonia in curing saltstone at 95 C. The test temperature represents the maximum allowable temperature in the Saltstone Disposal Facility (SDF). Ammonia may be present in the salt solution and premix materials, or may be produced by chemical reactions when the premix and salt solution are combined. A final report (SRNS-STI-2008-00120, Rev. 0) will be issued that will cover in more depth the information presented in this report.

  13. Ammonia downstream from HH 80 North

    NASA Technical Reports Server (NTRS)

    Girart, Jose M.; Rodriguez, Luis F.; Anglada, Guillem; Estalella, Robert; Torrelles, Jose, M.; Marti, Josep; Pena, Miriam; Ayala, Sandra; Curiel, Salvador; Noriega-Crespo, Alberto

    1994-01-01

    HH 80-81 are two optically visible Herbig-Haro (HH) objects located about 5 minutes south of their exciting source IRAS 18162-2048. Displaced symmetrically to the north of this luminous IRAS source, a possible HH counterpart was recently detected as a radio continuum source with the very large array (VLA). This radio source, HH 80 North, has been proposed to be a member of the Herbig-Haro class since its centimeter flux density, angular size, spectral index, and morphology are all similar to those of HH 80. However, no object has been detected at optical wavelengths at the position of HH 80 North, possibly because of high extinction, and the confirmation of the radio continuum source as an HH object has not been possible. In the prototypical Herbig-Haro objects HH 1 and 2, ammonia emission has been detected downstream of the flow in both objects. This detection has been intepreted as a result of an enhancement in the ammonia emission produced by the radiation field of the shock associated with the HH object. In this Letter we report the detection of the (1,1) and (2,2) inversion transitions of ammonia downstream HH 80 North. This detection gives strong suppport to the interpretation of HH 80 North as a heavily obscured HH object. In addition, we suggest that ammonia emission may be a tracer of embedded Herbig-Haro objects in other regions of star formation. A 60 micrometer IRAS source could be associated with HH 80 North and with the ammonia condensation. A tentative explanation for the far-infrared emission as arising in dust heated by their optical and UV radiation of the HH object is presented.

  14. Recycling Trends in the Plastics Manufacturing and Recycling Companies in Malaysia

    NASA Astrophysics Data System (ADS)

    Wahab, D. A.; Abidin, A.; Azhari, C. H.

    This study presents the findings from a study on the consumption of recycled materials and recycling practices in the plastics manufacturing industry and recycling companies in Malaysia. The findings were obtained from a survey conducted in twenty plastic manufacturing companies and detailed case studies in three recycling companies. The survey conducted in the plastic manufacturing companies` shows that the consumption rate for poly-olefins (PP and PE) is the highest among the resin types and the industrial sector that consumes the most plastic materials is the electrical and electronics sector. The consumption of recycled materials is high among the local manufacturing companies (80%) which are largely due to cost savings; about 20% of these companies conducted in-house recycling. The study has also shown that the medium scale industry consumes the most recycled materials as compared to the large and small scale industry. The rate of disposal for plastic materials in the local industry is approximately 5%. The detailed case studies conducted in the recycling companies have successfully identified the main processes involved in plastic recycling namely manual sorting, cleaning, drying, meshing/pelletising and packaging. These recycling companies obtained recycled materials from various sources including industrial scrap, dumping sites, local producers as well as imported sources. Pricing of recycled materials were based on classification according to grade and quality of the recycled materials. The study has reflected the extent of in-house recycling trends in the local plastic manufacturing companies and their dependency on the supply from the local recycling companies.

  15. Results of interlaboratory comparisons of column percolation tests.

    PubMed

    Kalbe, Ute; Berger, Wolfgang; Simon, Franz-Georg; Eckardt, Jürgen; Christoph, Gabriele

    2007-09-30

    Laboratory leaching tests may be used for source term determination as a basis for risk assessment for soil-groundwater pathway (leachate forecast) on contaminated sites in Germany. Interlaboratory comparisons on the evaluation of the reproducibility of column percolation tests were conducted within the framework of an integrated R+D program using three waste reference materials. The interlaboratory comparisons of column percolation tests showed good reproducibility of the results for inorganic and organic parameters as well as for the accompanying parameters. This is due to the stipulations concerning the time of contact between leachant and sample material as well as the sample placement in the columns. Different column dimensions used by the participants of the interlaboratory comparisons did not have any substantial influence on the column test results. PMID:17451876

  16. Fire spread and percolation in polydisperse compartment structures

    NASA Astrophysics Data System (ADS)

    Zekri, N.; Zekri, L.; Lallemand, C.; Pizzo, Y.; Kaiss, A.; Clerc, J.-P.; Porterie, B.

    2012-11-01

    In this paper, we employ a cellular automata and percolation analysis to model fire spread in polydisperse amorphous massively multi-compartmented structures (e.g. naval vessels, high-rise buildings, warehouses, or nuclear plants). Various shapes and sizes of compartments are considered. Each compartment is composed of nc equal-size cells. It is found that increasing nc increases fingering and lacunarities of fire patterns, and subsequently front roughness. However, this also increases the probability of fire propagation throughout the system as the percolation threshold presents a power-law decrease with nc -1 for small values of nc. For large polydisperse compartments, the propagation/non propagation transition seems to be size-independent. A special emphasis is put on the dynamics of fire propagation. Further study is needed to evaluate network properties that should help in developing better strategies to reduce fire consequences.

  17. Percolation modeling of self-damaging of composite materials

    NASA Astrophysics Data System (ADS)

    Domanskyi, Sergii; Privman, Vladimir

    2014-07-01

    We propose the concept of autonomous self-damaging in “smart” composite materials, controlled by activation of added nanosize “damaging” capsules. Percolation-type modeling approach earlier applied to the related concept of self-healing materials, is used to investigate the behavior of the initial material's fatigue. We aim at achieving a relatively sharp drop in the material's integrity after some initial limited fatigue develops in the course of the sample's usage. Our theoretical study considers a two-dimensional lattice model and involves Monte Carlo simulations of the connectivity and conductance in the high-connectivity regime of percolation. We give several examples of local capsule-lattice and capsule-capsule activation rules and show that the desired self-damaging property can only be obtained with rather sophisticated “smart” material's response involving not just damaging but also healing capsules.

  18. Price of anarchy is maximized at the percolation threshold

    NASA Astrophysics Data System (ADS)

    Skinner, Brian

    2015-05-01

    When many independent users try to route traffic through a network, the flow can easily become suboptimal as a consequence of congestion of the most efficient paths. The degree of this suboptimality is quantified by the so-called price of anarchy (POA), but so far there are no general rules for when to expect a large POA in a random network. Here I address this question by introducing a simple model of flow through a network with randomly placed congestible and incongestible links. I show that the POA is maximized precisely when the fraction of congestible links matches the percolation threshold of the lattice. Both the POA and the total cost demonstrate critical scaling near the percolation threshold.

  19. Vulnerability of networks: Fractional percolation on random graphs

    NASA Astrophysics Data System (ADS)

    Shang, Yilun

    2014-01-01

    We present a theoretical framework for understanding nonbinary, nonindependent percolation on networks with general degree distributions. The model incorporates a partially functional (PF) state of nodes so that both intensity and extensity of error are characterized. Two connected nodes in a PF state cannot sustain the load and therefore break their link. We give exact solutions for the percolation threshold, the fraction of giant cluster, and the mean size of small clusters. The robustness-fragility transition point for scale-free networks with a degree distribution pk?k-? is identified to be ? =3. The analysis reveals that scale-free networks are vulnerable to targeted attack at hubs: a more complete picture of their Achilles' heel turns out to be not only the hubs themselves but also the edges linking them together.

  20. Minimal spanning trees at the percolation threshold: A numerical calculation

    NASA Astrophysics Data System (ADS)

    Sweeney, Sean M.; Middleton, A. Alan

    2013-09-01

    The fractal dimension of minimal spanning trees on percolation clusters is estimated for dimensions d up to d=5. A robust analysis technique is developed for correlated data, as seen in such trees. This should be a robust method suitable for analyzing a wide array of randomly generated fractal structures. The trees analyzed using these techniques are built using a combination of Prim's and Kruskal's algorithms for finding minimal spanning trees. This combination reduces memory usage and allows for simulation of larger systems than would otherwise be possible. The path length fractal dimension ds of MSTs on critical percolation clusters is found to be compatible with the predictions of the perturbation expansion developed by T. S. Jackson and N. Read [Phys. Rev. EPLEEE81539-375510.1103/PhysRevE.81.021131 81, 021131 (2010)].

  1. An overview of recycling refractory materials

    SciTech Connect

    Bennett, James P.; Kwong, Kyei-Sing

    2004-09-01

    Refractory materials must be disposed of or recycled when removed from service. Off-specification or reject material has been reused by the refractory industry for a number of years, with small percentages of these materials added as a part of refractory formulations. Historically, limed reuse of spent refractory materials in other applications has occurred. Environmental legislation, stewardship programs, and other forces encouraged some businesses to recycle spent refractories. Reuse of spent refractory material varies considerably among different industries and with the location of the industrial user. Efforts to recycle, the driving forces for recycling, and issues and steps to be taken into account initiating a recycling program will be discussed.

  2. Traveling time and traveling length in critical percolation clusters

    Microsoft Academic Search

    Youngki Lee; José S. Andrade Jr.; Sergey V. Buldyrev; Nikolay V. Dokholyan; Shlomo Havlin; Peter R. King; Gerald Paul; H. Eugene Stanley

    1999-01-01

    We study traveling time and traveling length for tracer dispersion in two-dimensional bond percolation, modeling flow by tracer particles driven by a pressure difference between two points separated by Euclidean distance r. We find that the minimal traveling time tmin scales as tmin~r1.33, which is different from the scaling of the most probable traveling time, t~~r1.64. We also calculate the

  3. Three-dimensional percolation modeling of self-healing composites

    Microsoft Academic Search

    Alexander Dementsov; Vladimir Privman

    2008-01-01

    We study the self-healing process of materials with embedded ``glue''-carrying cells, in the regime of the onset of the initial fatigue. Three-dimensional numerical simulations within the percolation-model approach are reported. The main numerical challenge taken up in the present work has been to extend the calculation of the conductance to three-dimensional lattices. Our results confirm the general features of the

  4. Continuum percolation for randomly oriented soft-core prisms

    Microsoft Academic Search

    Martin O. Saar; Michael Manga

    2002-01-01

    We study continuum percolation of three-dimensional randomly oriented soft-core polyhedra (prisms). The prisms are biaxial or triaxial and range in aspect ratio over six orders of magnitude. Results for prisms are compared with studies for ellipsoids, rods, ellipses, and polygons and differences are explained using the concept of the average excluded volume, . For large-shape anisotropies we find close agreement

  5. Cost effectiveness of recycling: A systems model

    SciTech Connect

    Tonjes, David J., E-mail: david.tonjes@stonybrook.edu [Department of Technology and Society, College of Engineering and Applied Sciences, Stony Brook University, Stony Brook, NY 11794-3560 (United States); Waste Reduction and Management Institute, School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794-5000 (United States); Center for Bioenergy Research and Development, Advanced Energy Research and Technology Center, Stony Brook University, 1000 Innovation Rd., Stony Brook, NY 11794-6044 (United States); Mallikarjun, Sreekanth, E-mail: sreekanth.mallikarjun@stonybrook.edu [Department of Technology and Society, College of Engineering and Applied Sciences, Stony Brook University, Stony Brook, NY 11794-3560 (United States)

    2013-11-15

    Highlights: • Curbside collection of recyclables reduces overall system costs over a range of conditions. • When avoided costs for recyclables are large, even high collection costs are supported. • When avoided costs for recyclables are not great, there are reduced opportunities for savings. • For common waste compositions, maximizing curbside recyclables collection always saves money. - Abstract: Financial analytical models of waste management systems have often found that recycling costs exceed direct benefits, and in order to economically justify recycling activities, externalities such as household expenses or environmental impacts must be invoked. Certain more empirically based studies have also found that recycling is more expensive than disposal. Other work, both through models and surveys, have found differently. Here we present an empirical systems model, largely drawn from a suburban Long Island municipality. The model accounts for changes in distribution of effort as recycling tonnages displace disposal tonnages, and the seven different cases examined all show that curbside collection programs that manage up to between 31% and 37% of the waste stream should result in overall system savings. These savings accrue partially because of assumed cost differences in tip fees for recyclables and disposed wastes, and also because recycling can result in a more efficient, cost-effective collection program. These results imply that increases in recycling are justifiable due to cost-savings alone, not on more difficult to measure factors that may not impact program budgets.

  6. Recycling Guide: Reduce, Reuse, Recycle Recycling Information Call 301-496-7990 or visit the NEMS Website at http://www.nems.nih.gov

    E-print Network

    Baker, Chris I.

    Recycling Guide: Reduce, Reuse, Recycle Recycling Information ­ Call 301-496-7990 or visit the NEMS in COMMINGLED bin Rinse food/beverage containers before recycling No Pyrex or Styrofoam Printer and Copier Toner Cartridges in TONER CARTRIDGE bin Recycle packaging material in appropriate bin NIH charities

  7. Loopless nontrapping invasion-percolation model for fracking.

    PubMed

    Norris, J Quinn; Turcotte, Donald L; Rundle, John B

    2014-02-01

    Recent developments in hydraulic fracturing (fracking) have enabled the recovery of large quantities of natural gas and oil from old, low-permeability shales. These developments include a change from low-volume, high-viscosity fluid injection to high-volume, low-viscosity injection. The injected fluid introduces distributed damage that provides fracture permeability for the extraction of the gas and oil. In order to model this process, we utilize a loopless nontrapping invasion percolation previously introduced to model optimal polymers in a strongly disordered medium and for determining minimum energy spanning trees on a lattice. We performed numerical simulations on a two-dimensional square lattice and find significant differences from other percolation models. Additionally, we find that the growing fracture network satisfies both Horton-Strahler and Tokunaga network statistics. As with other invasion percolation models, our model displays burst dynamics, in which the cluster extends rapidly into a connected region. We introduce an alternative definition of bursts to be a consecutive series of opened bonds whose strengths are all below a specified value. Using this definition of bursts, we find good agreement with a power-law frequency-area distribution. These results are generally consistent with the observed distribution of microseismicity observed during a high-volume frack. PMID:25353434

  8. Loopless nontrapping invasion-percolation model for fracking

    NASA Astrophysics Data System (ADS)

    Norris, J. Quinn; Turcotte, Donald L.; Rundle, John B.

    2014-02-01

    Recent developments in hydraulic fracturing (fracking) have enabled the recovery of large quantities of natural gas and oil from old, low-permeability shales. These developments include a change from low-volume, high-viscosity fluid injection to high-volume, low-viscosity injection. The injected fluid introduces distributed damage that provides fracture permeability for the extraction of the gas and oil. In order to model this process, we utilize a loopless nontrapping invasion percolation previously introduced to model optimal polymers in a strongly disordered medium and for determining minimum energy spanning trees on a lattice. We performed numerical simulations on a two-dimensional square lattice and find significant differences from other percolation models. Additionally, we find that the growing fracture network satisfies both Horton-Strahler and Tokunaga network statistics. As with other invasion percolation models, our model displays burst dynamics, in which the cluster extends rapidly into a connected region. We introduce an alternative definition of bursts to be a consecutive series of opened bonds whose strengths are all below a specified value. Using this definition of bursts, we find good agreement with a power-law frequency-area distribution. These results are generally consistent with the observed distribution of microseismicity observed during a high-volume frack.

  9. Emergent Percolation Length and Localization in Random Elastic Networks

    NASA Astrophysics Data System (ADS)

    Amir, Ariel; Krich, Jacob J.; Vitelli, Vincenzo; Oreg, Yuval; Imry, Yoseph

    2013-04-01

    We study, theoretically and numerically, a minimal model for phonons in a disordered system. For sufficient disorder, the vibrational modes of this classical system can become Anderson localized, yet this problem has received significantly less attention than its electronic counterpart. We find rich behavior in the localization properties of the phonons as a function of the density, frequency, and spatial dimension. We use a percolation analysis to argue for a Debye spectrum at low frequencies for dimensions higher than one, and for a localization-delocalization transition (at a critical frequency) above two dimensions. We show that in contrast to the behavior in electronic systems, the transition exists for arbitrarily large disorder, albeit with an exponentially small critical frequency. The structure of the modes reflects a divergent percolation length that arises from the disorder in the springs without being explicitly present in the definition of our model. Within the percolation approach, we calculate the speed of sound of the delocalized modes (phonons), which we corroborate with numerics. We find the critical frequency of the localization transition at a given density and find good agreement of these predictions with numerical results using a recursive Green-function method that was adapted for this problem. The connection of our results to recent experiments on amorphous solids is discussed.

  10. Percolation and cooperation with mobile agents: Geometric and strategy clusters

    NASA Astrophysics Data System (ADS)

    Vainstein, Mendeli H.; Brito, Carolina; Arenzon, Jeferson J.

    2014-08-01

    We study the conditions for persistent cooperation in an off-lattice model of mobile agents playing the Prisoner's Dilemma game with pure, unconditional strategies. Each agent has an exclusion radius rP, which accounts for the population viscosity, and an interaction radius rint, which defines the instantaneous contact network for the game dynamics. We show that, differently from the rP=0 case, the model with finite-sized agents presents a coexistence phase with both cooperators and defectors, besides the two absorbing phases, in which either cooperators or defectors dominate. We provide, in addition, a geometric interpretation of the transitions between phases. In analogy with lattice models, the geometric percolation of the contact network (i.e., irrespective of the strategy) enhances cooperation. More importantly, we show that the percolation of defectors is an essential condition for their survival. Differently from compact clusters of cooperators, isolated groups of defectors will eventually become extinct if not percolating, independently of their size.

  11. Double Percolation Phase Transition in Clustered Complex Networks

    NASA Astrophysics Data System (ADS)

    Colomer-de-Simón, Pol; Boguñá, Marián

    2014-10-01

    The internal organization of complex networks often has striking consequences on either their response to external perturbations or on their dynamical properties. In addition to small-world and scale-free properties, clustering is the most common topological characteristic observed in many real networked systems. In this paper, we report an extensive numerical study on the effects of clustering on the structural properties of complex networks. Strong clustering in heterogeneous networks induces the emergence of a core-periphery organization that has a critical effect on the percolation properties of the networks. We observe a novel double phase transition with an intermediate phase in which only the core of the network is percolated and a final phase in which the periphery percolates regardless of the core. This result implies breaking of the same symmetry at two different values of the control parameter, in stark contrast to the modern theory of continuous phase transitions. Inspired by this core-periphery organization, we introduce a simple model that allows us to analytically prove that such an anomalous phase transition is, in fact, possible.

  12. High performance polyester concrete using recycled PET

    SciTech Connect

    Rebeiz, K.S. [Lafayette Coll., Easton, PA (United States). Dept. of Civil and Environmental Engineering

    1995-10-01

    Recycled polyethylene terephthalate (PET) plastic wastes could be used in production of unsaturated polyester resins. In turn, these resins could be mixed with inorganic aggregates to produce polymer concrete (PC). Unsaturated polyesters based on recycled PET might be a potentially lower source cost of resins for producing useful PC based-products. The advantage of recycling PET in PC is that the PET materials do not have to be purified, including removal of colors, to the same extent as other PET recycling applications, which should facilitate the recycling operation and minimize its cost. The recycling of PET in PC could also help save energy and allow the long term disposal of the PET waste, an important advantage in recycling applications.

  13. Composite material from recycled polyester for recyclable automobile structures

    SciTech Connect

    Lertola, J.G. [DuPont Company, Newark, DE (United States)

    1995-12-31

    DuPont has developed a compression-moldable composite made from the thermoplastic polyester PET and long glass fibers. This material, XTC{trademark}, is part of the class of materials known as GMT`s, or glass-mat thermoplastics. The PET content in XTC{trademark} allows the use of a wide variety of recycled material that might otherwise end up in landfills and incinerators. DuPont has succeeded in using 100% post-consumer polyester, from bottles, film, or fibers, in the composite. Since processing involves heating the material to the melt in air, the main technical issues are hydrolysis and oxidative degradation. Impurities in the recycled material must be carefully monitored, as they often increase the extent of degradation. The product itself, used to mold shaped structures and body panels for automobiles, may be recycled after its useful life. Depending on the needed purity level, processes ranging from injection molding to methanolysis can turn ground XTC{trademark} parts back into new, useful products.

  14. An Assessment of the Technical Readiness of the Vapor Phase Catalytic Ammonia Removal Process (VPCAR) Technology

    NASA Technical Reports Server (NTRS)

    Flynn, Michael

    2000-01-01

    This poster provides an assessment of the technical readiness of the Vapor Phase Catalytic Ammonia Removal Process (VPCAR). The VPCAR technology is a fully regenerative water recycling technology designed specifically for applications such as a near term Mars exploration mission. The VPCAR technology is a highly integrated distillation/catalytic oxidation based water processor. It is designed to accept a combined wastewater stream (urine, condensate, and hygiene) and produces potable water in a single process step which requires -no regularly scheduled re-supply or maintenance for a 3 year mission. The technology is designed to be modular and to fit into a volume comparable to a single International Space Station Rack (when sized for a crew of 6). This poster provides a description of the VPCAR technology and a summary of the current performance of the technology. Also provided are the results of two separate NASA sponsored system trade studies which investigated the potential payback of further development of the VPCAR technology.

  15. Electrical percolation-based biosensor for real-time direct detection of staphylococcal enterotoxin B (SEB)

    Microsoft Academic Search

    Minghui Yang; Steven Sun; Hugh Alan Bruck; Yordan Kostov; Avraham Rasooly

    2010-01-01

    Electrical percolation-based biosensing is a new technology. This is the first report of an electrical percolation-based biosensor for real-time detection. The label-free biosensor is based on electrical percolation through a single-walled carbon nanotubes (SWNTs)–antibody complex that forms a network functioning as a “Biological Semiconductor” (BSC). The conductivity of a BSC is directly related to the number of contacts facilitated by

  16. Scrap car recycling in Taiwan

    SciTech Connect

    Lee, C.H.; Tai, H.S.; Fan, R.K.S.

    1997-12-31

    The official figure of registered automobiles released by the Ministry of Transportation of Taiwan, R.O.C. as of the end of April 1996, is approximately 4.8 millions. Among them, 18% of the cars are between seven and ten years old and 15% of the cars are old than ten years. The result of this large number of old cars is the problem of abandoned cars on the street of Taiwan. This phenomena not only hinders traffic flow but also undermines the living quality in the cities. To minimize these negative effects, EPA has promulgated a Scrap Motor Vehicles Management Regulation to enforce the scrap car recycling in Taiwan. Under this regulation, a buyer of a new vehicle has to pay the Scrap Motor Vehicle Disposal fee (NT$ 3000, or US$ 110 for a car; and NT$ 700, or US$ 25 for a motorcycle). This paper presents the current status of scrap car recycling in Taiwan.

  17. Nanochannel Based Single Molecule Recycling

    PubMed Central

    Lesoine, John F.; Venkataraman, Prahnesh A.; Maloney, Peter C.; Dumont, Mark

    2012-01-01

    We present a method for measuring the fluorescence from a single molecule hundreds of times without surface immobilization. The approach is based on the use of electroosmosis to repeatedly drive a single target molecule in a fused silica nanochannel through a stationary laser focus. Single molecule fluorescence detected during the transit time through the laser focus is used to repeatedly reverse the electrical potential controlling the flow direction. Our method does not rely on continuous observation and therefore is less susceptible to fluorescence blinking than existing fluorescence-based trapping schemes. The variation in the turnaround times can be used to measure the diffusion coefficient on a single molecule level. We demonstrate the ability to recycle both proteins and DNA in nanochannels and show that the procedure can be combined with single-pair Förster energy transfer. Nanochannel-based single molecule recycling holds promise for studying conformational dynamics on the same single molecule in solution and without surface tethering. PMID:22662745

  18. Hail Formation via Microphysical Recycling.

    NASA Astrophysics Data System (ADS)

    Pflaum, John C.

    1980-01-01

    It is suggested that alternation of low-density riming and wet growth processes play a role in hailstone formation. Such alternation of growth processes, which has been called microphysical recycling, is envisioned to operate in the following manner. During low-density riming growth, hailstones require reduced updraft velocities as compared to hailstones growing via classical high-density ice acquisition. During subsequent wet growth, water soaks into the previously acquired porous rime and on freezing produces hard, dense hailstones compatible with samples collected at the surface. Such a two-stage process lessens the dynamical requirements of hail formation.This article elucidates the microphysical recycling mechanism, cloud conditions necessary to initiate it, evidence that it is operational in the atmosphere, and the possible consequences of its existence with regard to hail suppression.

  19. DWPF recycle minimization: Brainstorming session

    SciTech Connect

    Jacobs, R.A.; Poirier, M.R.

    1993-10-12

    The recycle stream from the DWPF constitutes a major source of water addition to the High Level Waste evaporator system. As now designed, the entire flow of 3.5 to 6.5 gal/min (@ 25% and 75% attainment, respectively), or 2 gal/min during idling, flow to the 2H evaporator system (Tank 43). Substantial improvement in the HLW water balance and tank volume management is expected if the DWPF recycle to the HLW evaporator system can be significantly reduced. A task team has been appointed to study alternatives for reducing the flow to the HLW evaporator system and make recommendations for implementation and/or further study and evaluation. The brainstorming session detailed in this report was designed to produce the first cut options for the task team to further evaluate.

  20. Recycling of aluminum matrix composites

    Microsoft Academic Search

    Yoshinori Nishida; Norihisa Izawa; Yukio Kuramasu

    1999-01-01

    Separation of matrix metals in composites was tried on alumina short fiber-reinforced aluminum and 6061 alloy composites and\\u000a SiC whisker-reinforced 6061 alloy composite for recycling. It is possible to separate molten matrix metals from fibers in\\u000a the composites using fluxes that are used for melt treatment to remove inclusions. About 50 vol pct of the matrix metals was\\u000a separated from