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1

PRETREATMENT AND FRACTIONATION OF CORN STOVER BY AMMONIA RECYCLE PERCOLATION PROCESS. (R831645)  

EPA Science Inventory

Corn stover was pretreated with aqueous ammonia in a flow-through column reactor, a process termed as Ammonia Recycle Percolation (ARP). The aqueous ammonia causes swelling and efficient delignification of biomass at high temperatures. The ARP process solubilizes abou...

2

Ammonia recycled percolation as a complementary pretreatment to the dilute-acid process  

SciTech Connect

A two-stage dilute-acid percolation (DA) was investigated as a pre-treatment method for switchgrass. With use of extremely low acid (0.078 wt% sulfuric acid) under moderate temperature (145-170{degrees}C), hemicellulose in switchgrass was completely solubilized showing no sugar decomposition. The treated switchgrass contained about 70% glucan and 30% lignin. The high lignin content in the treated feedstock raises a concern that it may cause a high enzyme consumption because of irreversible adsorption of cellulose enzymes to lignin. This problem may be amplified in the SSF operation since it is usually run in fed-batch mode and the residual lignin is accumulated. The DA pretreatment was, therefore, combined with the ammonia recycled percolation (ARP) process that has been proven to be effective in delignification. The combined pretreatment essentially fractionated the switchgrass into three major components. The treated feedstock contained about 90% glucan and 10% lignin. The digestibility of these samples was consistently higher than that of DA treated samples. Further study on the interaction of cellulase with xylan and that with lignin has shown that the enzymatic hydrolysis of cellulose is inhibited by lignin as well as xylan. The external xylan was found to be a noncompetitive inhibitor to cellulose hydrolysis. The cellulose used in this study was proven to have the xylanase activity. 23 refs., 8 figs., 4 tabs.

Wu, Zhangwen, Lee, Y.Y. [Auburn Univ., AL (United States)

1997-12-31

3

Recycle of tin thiolate compounds relevant to ammonia-borane regeneration.  

PubMed

The use of benzenedithiol as a digestant for ammonia-borane spent fuel has been shown to result in tin thiolate compounds which we demonstrate can be recycled, yielding Bu(3)SnH and ortho-benzenedithiol for reintroduction to the ammonia-borane regeneration scheme. PMID:20024322

Sutton, Andrew D; Davis, Benjamin L; Bhattacharyya, Koyel X; Ellis, Bobby D; Gordon, John C; Power, Philip P

2010-01-01

4

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...

5

Pretreatment of Biomass by Aqueous Ammonia for Bioethanol Production  

NASA Astrophysics Data System (ADS)

The methods of pretreatment of lignocellulosic biomass using aqueous ammonia are described. The main effect of ammonia treatment of biomass is delignification without significantly affecting the carbohydrate contents. It is a very effective pretreatment method especially for substrates that have low lignin contents such as agricultural residues and herbaceous feedstock. The ammonia-based pretreatment is well suited for simultaneous saccharification and co-fermentation (SSCF) because the treated biomass retains cellulose as well as hemicellulose. It has been demonstrated that overall ethanol yield above 75% of the theoretical maximum on the basis of total carbohydrate is achievable from corn stover pretreated with aqueous ammonia by way of SSCF. There are two different types of pretreatment methods based on aqueous ammonia: (1) high severity, low contact time process (ammonia recycle percolation; ARP), (2) low severity, high treatment time process (soaking in aqueous ammonia; SAA). Both of these methods are described and discussed for their features and effectiveness.

Kim, Tae Hyun; Gupta, Rajesh; Lee, Y. Y.

6

Recycling  

NSDL National Science Digital Library

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 ...

sgp0002

2010-03-27

7

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

PubMed

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

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

2014-06-17

8

Ammonia synthesis  

Microsoft Academic Search

In a process for producing ammonia in a synthesis loop in which fresh synthesis gas containing hydrogen, nitrogen and, lesser amounts of argon and methane is combined with a hydrogen enriched recycle gas to provide combined synthesis gas, the combined synthesis is introduced to and reacted over ammonia synthesis catalyst under synthesis conditions to provide converted gas containing ammonia, hydrogen,

B. G. Mandelik; J. R. Cassata; P. J. S. Katy; C. P. Van Dijk

1986-01-01

9

Recycling  

NSDL National Science Digital Library

What objects can be recycled? 1. Click on link. Watch video. Recycle Guy Video 2. Click on link. Watch video. Talking Trash Video 3. Click on link. Watch video. Recycling At School Video 4. Click on link. Play game. Star Fall Recycling Game 5. Click on link. Play game. National Geographic Recycling Game 6. Click on link. Ask Ms. Owens how to do it. Things We Recycle Chart 7. Please see Miss Owens for instructions on the following ...

2011-04-07

10

Recycling  

NSDL National Science Digital Library

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 ...

Miss Sykes

2005-10-20

11

Desulfurization in reducing atmosphere and ammonia injection denitrification in a coal-fired fluidized bed combustor with fly-ash recycle  

NASA Astrophysics Data System (ADS)

With the rising of IGCC and the second generation PFBC-CC, and with the development of technology of staged combustion to lower emission of NOx, the desulfurization efficiency under reducing atmosphere is raised. In this paper, with the application of the fly-ash recycle and two-stage combustion technologies in a fluidized bed combustor, the desulfurization test under reducing atmosphere is described. Meanwhile, ammonia injection test was also conducted. Results show that desulfurization under reducing atmosphere has higher efficiency, and ammonia injection denitrification effect is very perfect.

Zhong, Zhaoping; Lan, Jixiang; Han, Yongsheng; Wu, Xin; Zheng, Haiyun

1997-03-01

12

Supplemental ammonia synthesis  

Microsoft Academic Search

In a process for producing ammonia in a synthesis loop fresh ammonia synthesis gas containing hydrogen, nitrogen, and lesser amounts of argon and methane is combined with a recycle gas to provide a combined synthesis gas. A portion of the combined synthesis gas is reacted over ammonia synthesis catalyst containing iron to provide a first converted gas having an ammonia

G. S. B. Katy; J. R. LeBlanc; J. M. Lee; H. P. Leftin; P. J. S. Katy; C. P. Van Dijk

1986-01-01

13

Ammonia utilization process  

Microsoft Academic Search

This patent describes a process for gasification of organic carbonaceous materials in a hydrogen forming gasifier. The improvement consists of: separating ammonia from product gas of the gasifier by dissolving in an aqueous liquid forming sour water; separating the sour water from the gasifier product gas; separating gaseous ammonia from the sour water; and recycling the gaseous ammonia to the

1987-01-01

14

Ammonia purge gas conversion  

Microsoft Academic Search

In a process for producing ammonia in a first synthesis loop wherein fresh ammonia synthesis gas containing hydrogen, nitrogen, and lesser amounts of argon and methane is combined with a first recycle gas to provide a first combined synthesis gas, a portion of the first combined synthesis gas is reacted over ammonia synthesis catalyst containing iron to provide a first

C. P. Van Dijk; A. Solbakken; B. G. Mandelik

1986-01-01

15

Advanced Life Support Water Recycling Technologies Case Studies: Vapor Phase Catalytic Ammonia Removal and Direct Osmotic Concentration  

NASA Technical Reports Server (NTRS)

Design for microgravity has traditionally not been well integrated early on into the development of advanced life support (ALS) technologies. NASA currently has a many ALS technologies that are currently being developed to high technology readiness levels but have not been formally evaluated for microgravity compatibility. Two examples of such technologies are the Vapor Phase Catalytic Ammonia Removal Technology and the Direct Osmotic Concentration Technology. This presentation will cover the design of theses two systems and will identify potential microgravity issues.

Flynn, Michael

2004-01-01

16

Percolation Hamiltonians  

Microsoft Academic Search

\\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.

Peter M黮ler; Peter Stollmann

2010-01-01

17

Deterministic Percolation  

NASA Astrophysics Data System (ADS)

This paper examines percolation questions in a deterministic setting. In particular, I consider , the set of elements of Z2 with greatest common divisor equal to 1, where two sites are connected if they are at distance 1. The main result of the paper proves that the infinite component has an asymptotic density. An ``almost everywhere'' sieve of J. Friedlander is used to obtain the result.

Vardi, Ilan

18

Recovery of hydrogen and ammonia from purge gas  

Microsoft Academic Search

Ammonia and hydrogen values are recovered from the purge gas from an ammonia synthesis recycle stream by removing the ammonia from the purge gas by adsorption in an ammonia adsorber, thereafter separating the hydrogen by cryogenic partial condensation, the refrigeration for which is provided by expanding and evaporating the condensate, and recovering the ammonia from the adsorber by heating a

Isalski

1981-01-01

19

Substrate dependency and effect of xylanase supplementation on enzymatic hydrolysis of ammonia-treated biomass.  

PubMed

Pretreatment based on aqueous ammonia was investigated under two different modes of operation: soaking in aqueous ammonia and ammonia recycle percolation. These processes were applied to three different feedstocks with varied composition: corn stover, high lignin (HL), and low lignin (LL) hybrid poplars. One of the important features of ammonia-based pretreatment is that most of the hemicellulose is retained after treatment, which simplifies the overall bioconversion process and enhances the conversion efficiency. The pretreatment processes were optimized for these feedstocks, taking carbohydrate retention as well as sugar yield in consideration. The data indicate that hybrid poplar is more difficult to treat than corn stover, thus, requires more severe conditions. On the other hand, hybrid poplar has a beneficial property that it retains most of the hemicellulose after pretreatment. To enhance the digestibility of ammonia-treated poplars, xylanase was supplemented during enzymatic hydrolysis. Because of high retention of hemicellulose in treated hybrid poplar, xylanase supplementation significantly improved xylan as well as glucan digestibility. Of the three feedstocks, best results and highest improvement by xylanase addition was observed with LL hybrid poplar, showing 90% of overall sugar yield. PMID:18418740

Gupta, Rajesh; Kim, Tae Hyun; Lee, Yoon Y

2008-03-01

20

Substrate Dependency and Effect of Xylanase Supplementation on Enzymatic Hydrolysis of Ammonia-Treated Biomass  

NASA Astrophysics Data System (ADS)

Pretreatment based on aqueous ammonia was investigated under two different modes of operation: soaking in aqueous ammonia and ammonia recycle percolation. These processes were applied to three different feedstocks with varied composition: corn stover, high lignin (HL), and low lignin (LL) hybrid poplars. One of the important features of ammonia-based pretreatment is that most of the hemicellulose is retained after treatment, which simplifies the overall bioconversion process and enhances the conversion efficiency. The pretreatment processes were optimized for these feedstocks, taking carbohydrate retention as well as sugar yield in consideration. The data indicate that hybrid poplar is more difficult to treat than corn stover, thus, requires more severe conditions. On the other hand, hybrid poplar has a beneficial property that it retains most of the hemicellulose after pretreatment. To enhance the digestibility of ammonia-treated poplars, xylanase was supplemented during enzymatic hydrolysis. Because of high retention of hemicellulose in treated hybrid poplar, xylanase supplementation significantly improved xylan as well as glucan digestibility. Of the three feedstocks, best results and highest improvement by xylanase addition was observed with LL hybrid poplar, showing 90% of overall sugar yield.

Gupta, Rajesh; Kim, Tae Hyun; Lee, Yoon Y.

21

Ammonia Test  

MedlinePLUS

... of this website will be limited. Search Help? Ammonia Share this page: Was this page helpful? Also ... to normal, can it rise again? 1. Is ammonia testing used to detect or monitor ammonia poisoning? ...

22

Negative-weight percolation  

NASA Astrophysics Data System (ADS)

We describe a percolation problem on lattices (graphs, networks), with edge weights drawn from disorder distributions that allow for weights (or distances) of either sign, i.e. including negative weights. We are interested in whether there are spanning paths or loops of total negative weight. This kind of percolation problem is fundamentally different from conventional percolation problems, e.g. it does not exhibit transitivity, hence, no simple definition of clusters, and several spanning paths/loops might coexist in the percolation regime at the same time. Furthermore, to study this percolation problem numerically, one has to perform a non-trivial transformation of the original graph and apply sophisticated matching algorithms. Using this approach, we study the corresponding percolation transitions on large square, hexagonal and cubic lattices for two types of disorder distributions and determine the critical exponents. The results show that negative-weight percolation (NWP) is in a different universality class compared to conventional bond/site percolation. On the other hand, NWP seems to be related to the ferromagnet/spin-glass transition of random-bond Ising systems, at least in two dimensions.

Melchert, O.; Hartmann, A. K.

2008-04-01

23

Ammonia Process by Pressure Swing Adsorption  

SciTech Connect

The overall objective of the project is to design, develop and demonstrate a technically feasible and commercially viable system to produce ammonia along with recovery of the products by adsorption separation methods and significantly decrease the energy requirement in ammonia production. This is achieved through a significantly more efficient ammonia psa recovery system. The new ammonia recovery system receives the reactor effluents and achieves complete ammonia recovery, (which completely eliminates the energy intensive refrigeration and condensation system currently used in ammonia production). It also recovers the unused reactants and recycles them back to the reactor, free of potential reactor contaminants, and without the need for re-compression and re-heat of recycle stream thereby further saving more energy. The result is a significantly lower energy consumption, along with capital cost savings.

Dr Felix Jegede

2010-12-27

24

Explosive Percolation in Directed Networks  

E-print Network

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

Anlage, Steven

25

Multipartite entanglement percolation  

SciTech Connect

We present a percolation strategy based on multipartite measurements to propagate entanglement in quantum networks. We consider networks spanned on regular lattices whose bonds correspond to pure but nonmaximally entangled pairs of qubits, with any quantum operation allowed at the nodes. Despite significant effort in the past, improvements over standard (classical) percolation have been found for only a few lattices, often with restrictions on the initial amount of entanglement in the bonds. In contrast, multipartite entanglement percolation outperform the classical percolation protocols, as well as all previously known quantum ones, over the entire range of initial entanglement and for every lattice that we considered. Finally, we briefly show that our ideas also find application in noisy networks.

Perseguers, S. [Max-Planck-Institut fuer Quantenoptik, Hans-Kopfermann-Strasse 1, D-85748 Garching (Germany); Cavalcanti, D. [ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, E-08860 Castelldefels (Spain); Center for Quantum Technologies, National University of Singapore (Singapore); Lapeyre, G. J. Jr. [ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, E-08860 Castelldefels (Spain); Lewenstein, M.; Acin, A. [ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, E-08860 Castelldefels (Spain); ICREA-Institucio Catalana de Recerca i Estudis Avancats, Lluis Companys 23, E-08010 Barcelona (Spain)

2010-03-15

26

Percolation on sparse networks.  

PubMed

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. PMID:25432059

Karrer, Brian; Newman, M E J; Zdeborov, Lenka

2014-11-14

27

Ammonia Monitor  

NASA Technical Reports Server (NTRS)

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.

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

1999-01-01

28

Percolation and Deconfinement  

NASA Astrophysics Data System (ADS)

Possible phase transition of strongly interacting matter from hadron to a Quark-Gluon Plasma (QGP) state have in the past received considerable interest. It has been suggested that this problem might be treated by percolation theory. The Color String Percolation Model (CSPM) is used to determine the equation of state (EOS) of the QGP produced in central Au-Au collisions at RHIC energies. The bulk thermodynamic quantities - energy density, entropy density and the sound velocity - are obtained in the framework of CSPM. It is shown that the results are in excellent agreement with the recent lattice QCD calculations(LQCD).

Srivastava, Brijesh K.

2011-07-01

29

A Survey of Dynamical Percolation  

Microsoft Academic Search

Percolation is one of the simplest and nicest models in probability theory\\/statistical mechanics which exhibits critical phenomena.\\u000a Dynamical percolation is a model where a simple time dynamics is added to the (ordinary) percolation model. This dynamical\\u000a model exhibits very interesting behavior. Our goal in this survey is to give an overview of the work in dynamical percolation\\u000a that has been

Jeffrey E. Steif

30

Ammonia (GCMP)  

NSDL National Science Digital Library

Ammonia fountain: this is a resource in the collection "General Chemistry Multimedia Problems". In an ammonia fountain, a flask is filled with ammonia gas. A tube from the flask extends into a pan of water that contains phenolphthalein. When a rubber bulb full of water is squeezed, the water squirts into the flask. Water from the pan then is pushed into the flask and the indicator changes color. General Chemistry Multimedia Problems ask students questions about experiments they see presented using videos and images. The questions asked apply concepts from different parts of an introductory course, encouraging students to decompartmentalize the material.

31

Electrical Percolation Based Biosensors  

PubMed Central

A new approach to label free biosensing has been developed based on the principle of 揺lectrical 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 揼ate and SEB as an 揳ctuator, 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 揃iological Central Processing Units (CPUs) with multiple biological elements, capable of processing and sorting out information on multiple analytes simultaneously. PMID:24041756

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

2013-01-01

32

Development of Vapor-Phase Catalytic Ammonia Removal System  

NASA Technical Reports Server (NTRS)

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.

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

33

Process for manufacture of ammonia  

Microsoft Academic Search

An improved process is described for making synthetic ammonia wherein a make-up synthesis gas is added to recycled unreacted gas from the catalytic conversion loop including the steps of introducing a volatile anti-icing compound into the hot make-up gas to vaporize the compound, cooling the gas and vaporized anti-icing compound to condense part of the anti-icing compound, separating the condensed

Parrish

1986-01-01

34

Scaling theory of percolation clusters  

Microsoft Academic Search

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

D. Stauffer

1979-01-01

35

AN IMPROVED EXTRACTANT FOR SEPARATION OF AMMONIA FROM SOUR WATERS BY COMBINED STRIPPING AND EXTRACTION  

Microsoft Academic Search

With an appropriate liquid cation exchanger, ammonia can be extracted selectively from sour waters, thereby greatly reducing the energy requirement for stripping the acid gas(es) from the water. The ammonium form of the liquid cation exchanger is then decomposed thermally, yielding product ammonia and the ion exchanger for recycle. Such a process purifies the water and provides the ammonia and

Loree J. Poole; C. Judson King

1991-01-01

36

Hanford recycling  

SciTech Connect

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.

Leonard, I.M.

1996-09-01

37

Recycle City  

NSDL National Science Digital Library

Recycle City contains an interactive city map that demonstrates how residents of every section of the city, formerly Dumptown, have recycled, reduced, and reused waste to turn their town around. There is a Dumptown Game with a Control Center to monitor displays while Dumptown changes as waste reduction programs are put in place. Students can create their own Recycle City scavenger hunt or go to the Activities area and see other ways to put Recycle City to use to help protect the environment.

1997-01-01

38

Recycled roads  

SciTech Connect

This article examines the efforts of various states in the USA to recycle waste materials in highway construction as fill and pavements. The topics of the article include recycling used tires whole, ground, and shredded, cost of recycling, wood fiber chips as fill material in embankments, and mining wastes used to construct embankments and as coarse aggregates in asphalt pavement.

Tarricone, P.

1993-04-01

39

Watersheds and Explosive percolation  

E-print Network

The recent work by Achlioptas, D'Souza, and Spencer opened up the possibility of obtaining a discontinuous (explosive) percolation transition by changing the stochastic rule of bond occupation. Despite the active research on this subject, several questions still remain open about the leading mechanism and the properties of the system. We review the largest cluster and the Gaussian models recently introduced. We show that, to obtain a discontinuous transition it is solely necessary to control the size of the largest cluster, suppressing the growth of a cluster differing significantly, in size, from the average one. As expected for a discontinuous transition, a Gaussian cluster-size distribution and compact clusters are obtained. The surface of the clusters is fractal, with the same fractal dimension of the watershed line.

Herrmann, Hans J

2011-01-01

40

Watersheds and Explosive percolation  

NASA Astrophysics Data System (ADS)

The recent work by Achlioptas, D'Souza, and Spencer opened up the possibility of obtaining a discontinuous (explosive) percolation transition by changing the stochastic rule of bond occupation. Despite the active research on this subject, several questions still remain open about the leading mechanism and the properties of the system. We review the largest cluster and the Gaussian models recently introduced. We show that, to obtain a discontinuous transition it is solely necessary to control the size of the largest cluster, suppressing the growth of a cluster di_ering significantly, in size, from the average one. As expected for a discontinuous transition, a Gaussian cluster-size distribution and compact clusters are obtained. The surface of the clusters is fractal, with the same fractal dimension of the watershed line.

Herrmann, Hans J.; Araujo, Nuno A. M.

41

RECYCLING TODAY  

NSDL National Science Digital Library

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 ...

Miss Smith

2010-12-03

42

Stacked triangular lattice: Percolation properties  

NASA Astrophysics Data System (ADS)

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=0.186020.00002 for bonds and pcsite=0.262400.00005 for sites. The number of clusters at the threshold per site is ncbond=0.284580.00005 and ncsite=0.039980.00005. 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.

Schrenk, K. J.; Ara鷍o, N. A. M.; Herrmann, H. J.

2013-03-01

43

Predicting percolation thresholds in networks  

NASA Astrophysics Data System (ADS)

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.

Radicchi, Filippo

2015-01-01

44

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.

45

Ideas: Recycling.  

ERIC Educational Resources Information Center

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)

Chessin, Debby A.; And Others

1994-01-01

46

Explosive Percolation Transition is Actually Continuous  

NASA Astrophysics Data System (ADS)

Recently a discontinuous percolation transition was reported in a new 揺xplosive percolation problem for irreversible systems [D. Achlioptas, R. M. D扴ouza, and J. Spencer, Science 323, 1453 (2009)SCIEAS0036-807510.1126/science.1167782] in striking contrast to ordinary percolation. We consider a representative model which shows that the explosive percolation transition is actually a continuous, second order phase transition though with a uniquely small critical exponent of the percolation cluster size. We describe the unusual scaling properties of this transition and find its critical exponents and dimensions.

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

2010-12-01

47

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

Microsoft Academic Search

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

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

1987-01-01

48

Process for treating gases in the ammonia synthesis. [separation and dehydration of gases leaving synthesis reactor  

Microsoft Academic Search

In the synthesis of ammonia, a process is disclosed for treating the gases flowing from the synthesis reactor wherein those gases flow through a film absorber countercurrent to a cooled aqueous film to extract ammonia which is withdrawn as a strong solution from the absorber and scrubbed gases are combined for recycle with a stream of fresh feed which is

Guadalupi

1977-01-01

49

Logarithmic observables in critical percolation  

NASA Astrophysics Data System (ADS)

Although it has long been known that the proper quantum field theory description of critical percolation involves a logarithmic conformal field theory (LCFT), no direct consequence of this has been observed so far. Representing critical bond percolation as the Q ? 1 limit of the Q-state Potts model, and analyzing the underlying SQ symmetry of the Potts spins, we identify a class of simple observables whose two-point functions scale logarithmically for Q ? 1. The logarithm originates from the mixing of the energy operator with a logarithmic partner that we identify as the field that creates two propagating clusters. In d = 2 dimensions this agrees with general LCFT results, and in particular the universal prefactor of the logarithm can be computed exactly. We confirm its numerical value by carrying out extensive Monte Carlo simulations.

Vasseur, Romain; Lykke Jacobsen, Jesper; Saleur, Hubert

2012-07-01

50

Tire Recycling  

NASA Technical Reports Server (NTRS)

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.

1997-01-01

51

Recycling polyurethanes  

SciTech Connect

This article reports on the PolyUrethane Recycle and Recovery Council`s continuing evaluation of the technical and commercial viability of polyurethane recovery and recycling technologies. In North America, 240,000 tonnes of post-industrial and 16,000 tonnes of post-consumer polyurethane foam was recycled into carpet rebound underlay and other applications in 1993. Demand was so great in North America that 60,000 t of primarily post-industrial scarp was imported from Europe and the Far East. Polyurethane from the seats of the 9 million vehicles scrapped each year could yield 82,000 t of flexible post-consumer foam scrap: instrument and door panels could yield another 10,000 t of semi-flexible scrap.

NONE

1995-08-01

52

String percolation and the Glasma  

NASA Astrophysics Data System (ADS)

We compare string percolation phenomenology to Glasma results on particle rapidity densities, effective string or flux tube intrinsic correlations, the ridge phenomena and long range forward-backward correlations. Effective strings may be a tool to extend the Glasma to the low density QCD regime. A good example is given by the minimum of the negative binomial distribution parameter k expected to occur at low energy/centrality.

de Deus, J. Dias; Pajares, C.

2011-01-01

53

Rigidity percolation in foamy sands  

NASA Astrophysics Data System (ADS)

When subjected to a small shear stress, an aqueous foam behaves as a linear viscoelastic materials, whereas large applied shear stress triggers bubble rearrangement which causes the foam to flow as a viscous liquid. The elastic behavior arises from the surface tension of the gas-liquid interfaces. We study experimentally how the shear modulus and the yield stress of foam are modified if non colloidal solid particles of controlled size are dispersed in the sample. We show that even small amounts of non colloidal particles added to a foam can enhance the viscoelastic shear modulus by more than an order of magnitude. The yield stress is also increased, but to a smaller extent. The scaling of the elasticity enhancement with solid fraction qualitatively agrees with that predicted by an effective medium rigidity percolation model in the superelastic limit. To gain insight about the interactions between solid particles that are involved in the rigidity percolation, we study the dependence of the percolation threshold with particle to bubble size ratio.

Cohen-Addad, Sylvie; Hohler, Reinhard; Krzan, Marcel; Marinic, Marijo; Herzhaft, Benjamin

2006-03-01

54

Site-Percolation Threshold of Carbon Nanotube Fibers: Fast Inspection of Percolation with Markov Stochastic Theory  

E-print Network

We present a site-percolation model based on a modified FCC lattice, as well as an efficient algorithm of inspecting percolation which takes advantage of the Markov stochastic theory, in order to study the percolation threshold of carbon nanotube (CNT) fibers. Our Markov-chain based algorithm carries out the inspection of percolation by performing repeated sparse matrix-vector multiplications, which allows parallelized computation to accelerate the inspection for a given configuration. With this approach, we determine that the site-percolation transition of CNT fibers occurs at p_c =0.1533+-0.0013, and analyze the dependence of the effective percolation threshold (corresponding to 0.5 percolation probability) on the length and the aspect ratio of a CNT fiber on a finite-size-scaling basis. We also discuss the aspect ratio dependence of percolation probability with various values of p (not restricted to p_c).

Xu, Fangbo; Yakobson, Boris I

2014-01-01

55

Extreme Recycling  

E-print Network

oil becomes fertilizer; food scraps get composted. Right now, Kamikatsu has an amazing 80% recycling rate. Impressive, yes but not good enough for the die-hard Kamikatsuites. Their goal: a Zero G environment. Zero G for Zero Garbage. #hacker #japan...

Hacker, Randi

2009-01-14

56

Recycling BIOPOL朇omposting and Material Recycling  

Microsoft Academic Search

The recycling of biodegradable thermoplastics such as ZENECA's BIOPOL range of poly-3-hydroxybutyrate and poly-3-hydroxyvalerate copolymers needs to be considered in terms of both material recycling and organic recycling by composting. BIOPOL can be recycled as regrind. The addition of BIOPOL to a model waste stream demonstrates that at the anticipated addition levels, BIOPOL should not have a deleterious effect on

M. K. Cox

1995-01-01

57

Precipitation Recycling  

NASA Technical Reports Server (NTRS)

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?

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

1996-01-01

58

Computer Recycling  

NSDL National Science Digital Library

Given current rates of computer consumerism and technological advances, one might expect to find a lot of computers out there in the world. What happens to these old computers? This Topic in Depth explores this issue, reviews some options for recycling computers, and provides tips for anyone considering purchasing a refurbished computer. The first article from BBC News (1) reports on research which suggests that "the number of personal computers worldwide is expected to double by 2010 to 1.3 billion machines." The second article from Oasis, a project of the Irish eGovernment initiative, (2) reviews some of the issues surrounding waste from electrical and electronic equipment. This next article from PC World (3) gives some ideas for how to dispose of an old notebook computer. One option, of course, is to donate your notebook, which is discussed in this article from Tech Soup (4). Another resource for information on computer recycling and reuse is this website from CompuMentor (5). Given the current market for computers, many are considering refurbished computers. This article from Vnunet (6 ) explains what a refurbished computer is while the next website provides some tips for buying a refurbished computer (7 ). Finally, this article from About.com reports on the recently introduced National Computer Recycling Act (8).

59

Control of Reactor and Separator, with Recycle T. Larsson, S. Skogestadand Cheng-Ching Yu  

E-print Network

systems. Some examples of gas phase systems are ammonia and methanol plants. For example, consider a CSTR, and includes both liquid phase and gas phase systems. Some examples of gas phase systems are ammoniaControl of Reactor and Separator, with Recycle T. Larsson, S. Skogestad拢and Cheng-Ching Yu

Skogestad, Sigurd

60

Sources of atmospheric ammonia  

NASA Astrophysics Data System (ADS)

The information available on factors that influence emissions from the principal societal sources of ammonia to the atmosphere, namely combustion processes, volatilization of farm animal wastes, and volatilization of fertilizers, is reviewed. Emission factors are established for each major source of atmospheric ammonia. The factors are then multiplied by appropriate source characterization descriptors to obtain calculated fluxes of ammonia to the atmosphere on a state-by-state basis for the United States.

Harriss, R. C.; Michaels, J. T.

1982-05-01

61

Fusion algebra of critical percolation  

E-print Network

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.

Jorgen Rasmussen; Paul A. Pearce

2007-08-08

62

Combustion Byproducts Recycling Consortium  

SciTech Connect

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 private-sector 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.

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

2008-08-31

63

Combustion Byproducts Recycling Consortium  

SciTech Connect

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, 揷lean 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 揳llowable 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.

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

2008-08-31

64

Green Science: Revisiting Recycling  

ERIC Educational Resources Information Center

Recycling has been around for a long time--people have reused materials and refashioned them into needed items for thousands of years. More recently, war efforts encouraged conservation and reuse of materials, and in the 1970s recycling got its official start when recycling centers were created. Now, curbside recycling programs and recycling

Palliser, Janna

2011-01-01

65

Assessing Ammonia Treatment Options  

EPA Science Inventory

This is the second of three articles to help water system operators understand ammonia and how to monitor and control its effects at the plant and in the distribution system. The first article (Opflow, April 2012) provided an overview of ammonia's chemistry, origins, and water sy...

66

Percolation Approach to the Metal-Insulator Transition in SuperCritical Fluid Metals. II. ---Quantal Percolation Approach  

Microsoft Academic Search

We study a quantal percolation process in a square lattice gas in the super-critical regions by making use of a computer simulation. Critical quantal percolation density is determined by a criterion of electron localization. Our result suggests that the critical quantal percolation density is very close to the critical density for the classical percolation at all temperatures above the critical

Takashi Odagaki; Naofumi Ogita; Hirotsugu Matsuda

1979-01-01

67

Percolation in cluster-cluster aggregation processes  

NASA Astrophysics Data System (ADS)

Numerical simulations of diffusion-limited and reaction-limited cluster-cluster aggregation processes of identical particles are performed in a two-dimensional box. It is shown that, for concentrations larger than a characteristic gel concentration, the morphology of the resulting spanning cluster at the gel time tg exhibits a crossover length Ic between percolation (l>Lc) and aggregation (l0) the entire spanning cluster scales as the percolating cluster obtained by standard percolation. Even if for 0.5percolation, the scaling mass analysis and the vanishing links in the structure suggest that a homogeneous regime appears at small scales.

Hasmy, Anwar; Jullien, R閙i

1996-02-01

68

Noise sensitivity of Boolean functions and percolation  

E-print Network

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

Steif, Jeffrey

69

Percolation on networks with dependence links  

NASA Astrophysics Data System (ADS)

As a classical model of statistical physics, the percolation theory provides a powerful approach to analyze the network structure and dynamics. Recently, to model the relations among interacting agents beyond the connection of the networked system, the concept of dependence link is proposed to represent the dependence relationship of agents. These studies suggest that the percolation properties of these networks differ greatly from those of the ordinary networks. In particular, unlike the well known continuous transition on the ordinary networks, the percolation transitions on these networks are discontinuous. Moreover, these networks are more fragile for a broader degree distribution, which is opposite to the famous results for the ordinary networks. In this article, we give a summary of the theoretical approaches to study the percolation process on networks with inter- and inner-dependence links, and review the recent advances in this field, focusing on the topology and robustness of such networks.

Li, Ming; Wang, Bing-Hong

2014-07-01

70

Connectivity percolation in suspensions of hard platelets.  

PubMed

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 rodlike particles, we find that for hard platelike particles the percolation threshold is nonmonotonic 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 preempting 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 platelike fillers such as graphene and graphite nanoplatelets. PMID:23005096

Mathew, Maneesh; Schilling, Tanja; Oettel, Martin

2012-06-01

71

Ammonia Leak Locator Study  

NASA Technical Reports Server (NTRS)

The thermal control system of International Space Station Alpha will use liquid ammonia as the heat exchange fluid. It is expected that small leaks (of the order perhaps of one pound of ammonia per day) may develop in the lines transporting the ammonia to the various facilities as well as in the heat exchange equipment. Such leaks must be detected and located before the supply of ammonia becomes critically low. For that reason, NASA-JSC has a program underway to evaluate instruments that can detect and locate ultra-small concentrations of ammonia in a high vacuum environment. To be useful, the instrument must be portable and small enough that an astronaut can easily handle it during extravehicular activity. An additional complication in the design of the instrument is that the environment immediately surrounding ISSA will contain small concentrations of many other gases from venting of onboard experiments as well as from other kinds of leaks. These other vapors include water, cabin air, CO2, CO, argon, N2, and ethylene glycol. Altogether, this local environment might have a pressure of the order of 10(exp -7) to 10(exp -6) torr. Southwest Research Institute (SwRI) was contracted by NASA-JSC to provide support to NASA-JSC and its prime contractors in evaluating ammonia-location instruments and to make a preliminary trade study of the advantages and limitations of potential instruments. The present effort builds upon an earlier SwRI study to evaluate ammonia leak detection instruments [Jolly and Deffenbaugh]. The objectives of the present effort include: (1) Estimate the characteristics of representative ammonia leaks; (2) Evaluate the baseline instrument in the light of the estimated ammonia leak characteristics; (3) Propose alternative instrument concepts; and (4) Conduct a trade study of the proposed alternative concepts and recommend promising instruments. The baseline leak-location instrument selected by NASA-JSC was an ion gauge.

Dodge, Franklin T.; Wuest, Martin P.; Deffenbaugh, Danny M.

1995-01-01

72

SOURCE ASSESSMENT: SYNTHETIC AMMONIA PRODUCTION  

EPA Science Inventory

The report describes a study of air emissions from the production of synthetic ammonia. In 1976, 90 synthetic ammonia plants in 30 states produced 15.2 million metric tons of anhydrous ammonia. Ammonia is synthesized by the reaction of nitrogen and hydrogen. Most plants produce h...

73

Reactor for removing ammonia  

DOEpatents

Disclosed is a device for removing trace amounts of ammonia from a stream of gas, particularly hydrogen gas, prepared by a reformation apparatus. The apparatus is used to prevent PEM "poisoning" in a fuel cell receiving the incoming hydrogen stream.

Luo, Weifang (Livermore, CA); Stewart, Kenneth D. (Valley Springs, CA)

2009-11-17

74

Ammonia Release on ISS  

NASA Technical Reports Server (NTRS)

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

Macatangay, Ariel

2009-01-01

75

Multiple-well invasion percolation.  

PubMed

When the invasion percolation model is applied as a simplified model for the displacement of a viscous fluid by a less viscous one, the distribution of displaced mass follows two distinct universality classes, depending on the criteria used to stop the displacement. Here we study the distribution of mass for this process, in the case where four extraction wells are placed around a single injection well in the middle of a square lattice. Our analysis considers the limit where the pressure of the extraction well Pe is zero; in other words, an extraction well is capped as soon as less viscous fluid reaches that extraction well. Our results show that, as expected, the probability of stopping the production with small amounts of displaced mass is greatly reduced. We also investigate whether or not creating extra extraction wells is an efficient strategy. We show that the probability of increasing the amount of displaced fluid by adding an extra extraction well depends on the total recovered mass obtained before adding this well. The results presented here could be relevant to determine efficient strategies in oil exploration. PMID:18517620

Ara鷍o, A D; Romeu, M C; Moreira, A A; Andrade, R F S; Andrade, J S

2008-04-01

76

Ammonia Clouds on Jupiter  

NASA Technical Reports Server (NTRS)

[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.

2007-01-01

77

Recycle Used Oil on America Recycles Day.  

ERIC Educational Resources Information Center

Explains that motor oils can be reused and recycled. Educates students about environmental hazards and oil management and includes classroom activities. Addresses the National Science Education Standards. (YDS)

White, Boyd W.

2000-01-01

78

Recycled Art: Create Puppets Using Recycled Objects.  

ERIC Educational Resources Information Center

Presents an activity from "Healthy Foods from Healthy Soils" for making puppets using recycled food packaging materials. Includes background information, materials, instructions, literature links, resources, and benchmarks. (NB)

Clearing, 2003

2003-01-01

79

Electrical percolation in short fiber composites  

SciTech Connect

Thermoplastics containing conductive reinforcements provide as effective an EMI shielding as that provided by secondary metallization techniques, while affording mechanical strength and greater cost savings. The properties of short fiber reinforced composites are related to its structure and this structure is controlled by processing. The present study utilizes experimentally measured microstructure of injection molded short carbon fiber/Nylon 6, 6 composites to model the electrical percolation behavior. The experimentally measured fiber length distributions and fiber orientation distributions are incorporated into the continuum space simulations based on a concentric cylindrical model. Finite size scaling is applied to investigate the thresholds in infinitely large systems. The microstructure is also considered as a growing fractal. The simulations provide cluster number and cluster size for the fractal growth. The fractal dimension and percolation exponents are determined for large clusters near percolation.

Dani, A.A.; Ogale, A.A. [Clemson Univ., SC (United States)

1994-12-31

80

Solution of the explosive percolation quest  

E-print Network

Percolation refers to the emergence of a giant connected cluster in a disordered system when the number of connections between nodes exceeds a critical value. The percolation phase transitions were believed to be continuous until recently when in a new so-called "explosive percolation" problem for a competition driven process, a discontinuous phase transition was reported. The analysis of evolution equations for this process showed however that this transition is actually continuous though with surprisingly tiny critical exponents. For a wide class of representative models, we develop a strict scaling theory of this exotic transition which provides the full set of scaling functions and critical exponents. This theory indicates the relevant order parameter and susceptibility for the problem, and explains the continuous nature of this transition and its unusual properties.

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

2014-05-05

81

Bootstrap Percolation on Random Geometric Graphs  

E-print Network

Bootstrap percolation has been used effectively to model phenomena as diverse as emergence of magnetism in materials, spread of infection, diffusion of software viruses in computer networks, adoption of new technologies, and emergence of collective action and cultural fads in human societies. It is defined on an (arbitrary) network of interacting agents whose state is determined by the state of their neighbors according to a threshold rule. In a typical setting, bootstrap percolation starts by random and independent "activation" of nodes with a fixed probability $p$, followed by a deterministic process for additional activations based on the density of active nodes in each neighborhood ($\\th$ activated nodes). Here, we study bootstrap percolation on random geometric graphs in the regime when the latter are (almost surely) connected. Random geometric graphs provide an appropriate model in settings where the neighborhood structure of each node is determined by geographical distance, as in wireless {\\it ad hoc} ...

Bradonji?, Milan

2012-01-01

82

Control of Reactor and Separator, with Recycle T. Larsson, S. Skogestad and ChengChing Yu y  

E-print Network

systems. Some examples of gas phase systems are ammonia and methanol plants. For example, consider a CSTRControl of Reactor and Separator, with Recycle T. Larsson, S. Skogestad #3; and Cheng颅Ching Yu y This paper looks at control of a plant that consists of a reactor, separator and recycle of unreacted

Skogestad, Sigurd

83

The Chemistry of Liquid Ammonia.  

ERIC Educational Resources Information Center

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)

Lagowski, J. J.

1978-01-01

84

The Ammonia-Soda Process.  

ERIC Educational Resources Information Center

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)

Tingle, M.

1979-01-01

85

Liberation of ammonia by cyanobacteria  

SciTech Connect

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.

Newton, J.W.

1986-04-01

86

Recycling Rules: Understanding Recycling and a MRF  

NSDL National Science Digital Library

In this activity, learners simulate the separation techniques that materials recovery facilities (MRFs) use and then design their own series of recycling techniques. Learners identify four ways recyclable materials can be separated and sorted at a MRF: conveyor belts, blowers, flotation, and magnetism.

2013-01-17

87

Federal Recycling Program Printed on Recycled Paper  

E-print Network

in human resource and community assistance programs to improve living conditions in rural areas 路 ResearchFederal Recycling Program Printed on Recycled Paper The Forest Service, U.S. Department for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center

Standiford, Richard B.

88

Federal Recycling Program Printed on Recycled Paper  

E-print Network

and community assistance programs to imporve living conditions in rural areas; and Research on all aspectsFederal Recycling Program Printed on Recycled Paper The Forest Service, U.S. Department.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint

Standiford, Richard B.

89

Recycling overview in Sweden  

SciTech Connect

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.

Not Available

1989-07-01

90

Reading, 'Riting, 'Rithmetic & Recycling.  

ERIC Educational Resources Information Center

Discusses the growing environmental education movement and what constitutes good education about recycling and the environment. Lists characteristics of environmental education resources and examines criticism of environmental education and recycling education. Cites 19 references. (LZ)

Hill, Jim, Ed.

1995-01-01

91

FOREST FIRES AND OIL FIELDS AS PERCOLATION PHENOMENA.  

E-print Network

FOREST FIRES AND OIL FIELDS AS PERCOLATION PHENOMENA. William J. Reed #3; JUNE, 1999. Abstract A probability distribution derived from percolation theory is #12;tted to large datasets on the sizes of forest forest #12;res and oil #12;elds as percolation phenomena as well as suggesting the consideration of a new

Reed, W.J.

92

Percolation theory and its application to groundwater hydrology  

Microsoft Academic Search

The theory of percolation, originally proposed over 30 years ago to describe flow phenomena in porous media, has undergone enormous development in recent years, primarily in the field of physics. The principal advantage of percolation theory is that it provides universal laws which determine the geometrical and physical properties of the system. This survey discusses developments and results in percolation

Brian Berkowitz; Isaac Balberg

1993-01-01

93

Self-similar Fractals: Projections, Sections and Percolation  

E-print Network

Self-similar Fractals: Projections, Sections and Percolation Kenneth Falconer University of St Andrews, Scotland, UK Kenneth Falconer Self-similar Fractals: Projections, Sections and Percolation #12;Summary 路 Self-similar sets 路 Hausdorff dimension 路 Projections 路 Fractal percolation 路 Sections or slices

Falconer, Kenneth

94

7, 383403, 2007 Ammonia aged  

E-print Network

ACPD 7, 383颅403, 2007 Ammonia aged montmorillonite as ice nuclei A. Salam et al. Title Page Chemistry and Physics Discussions Ice nucleation of ammonia gas exposed montmorillonite mineral dust@mathstat.dal.ca) 383 #12;ACPD 7, 383颅403, 2007 Ammonia aged montmorillonite as ice nuclei A. Salam et al. Title Page

Paris-Sud XI, Universit茅 de

95

5, 25052540, 2008 Modeling ammonia  

E-print Network

BGD 5, 2505颅2540, 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, 2505颅2540, 2008 Modeling ammonia interactions with measured leaf wetness in grassland J. Burkhardt et

Paris-Sud XI, Universit茅 de

96

Atmospheric Ammonia From Undisturbed Land  

Microsoft Academic Search

Emissions of ammonia from the land areas of the world are calculated by using a simplified model. Soil ammonium concentrations are obtained from relative decomposition and nitrification rates; Henry's law gives the equilibrium concentration of ammonia gas in the soil, and a simplified diffusion equation yields the flux to the atmosphere. The model predicts negligible ammonia production in the polar

G. A. Dawson

1977-01-01

97

AMMONIA DISTILLATION FOR DEUTERIUM SEPARATION  

Microsoft Academic Search

The relative volatility or separation factor for deuterium enrichment in ; ammonia distillation was measured at several pressures and deuterium ; concentrations. The knowledge of this ingormation is very helpful in predicting ; costs of heawy water production by the ammonia distillation process. It hss been ; stated by others, that the ammonia distillation process of heawy water production ;

G. T. Petersen; M. Benedict

1960-01-01

98

Rethink, Rework, Recycle.  

ERIC Educational Resources Information Center

Information about the recycling and reuse of plastics, aluminum, steel, glass, and newspapers is presented. The phases of recycling are described. An activity that allows students to separate recyclable materials is included. The objectives, a list of needed materials, and procedure are provided. (KR)

Wrhen, Linda; DiSpezio, Michael A.

1991-01-01

99

Recycling and the automobile  

SciTech Connect

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.

Holt, D.J.

1993-10-01

100

Much Ado about Recycling.  

ERIC Educational Resources Information Center

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

Elliot, Ian

1993-01-01

101

Temporal percolation in activity-driven networks  

NASA Astrophysics Data System (ADS)

We study the temporal percolation properties of temporal networks by taking as a representative example the recently proposed activity-driven-network model [N. Perra et al., Sci. Rep. 2, 469 (2012), 10.1038/srep00469]. Building upon an analytical framework based on a mapping to hidden variables networks, we provide expressions for the percolation time Tp marking the onset of a giant connected component in the integrated network. In particular, we consider both the generating function formalism, valid for degree-uncorrelated networks, and the general case of networks with degree correlations. We discuss the different limits of the two approaches, indicating the parameter regions where the correlated threshold collapses onto the uncorrelated case. Our analytical predictions are confirmed by numerical simulations of the model. The temporal percolation concept can be fruitfully applied to study epidemic spreading on temporal networks. We show in particular how the susceptible-infected-removed model on an activity-driven network can be mapped to the percolation problem up to a time given by the spreading rate of the epidemic process. This mapping allows us to obtain additional information on this process, not available for previous approaches.

Starnini, Michele; Pastor-Satorras, Romualdo

2014-03-01

102

Temporal percolation in activity-driven networks.  

PubMed

We study the temporal percolation properties of temporal networks by taking as a representative example the recently proposed activity-driven-network model [N. Perra et al., Sci. Rep. 2, 469 (2012)]. Building upon an analytical framework based on a mapping to hidden variables networks, we provide expressions for the percolation time Tp marking the onset of a giant connected component in the integrated network. In particular, we consider both the generating function formalism, valid for degree-uncorrelated networks, and the general case of networks with degree correlations. We discuss the different limits of the two approaches, indicating the parameter regions where the correlated threshold collapses onto the uncorrelated case. Our analytical predictions are confirmed by numerical simulations of the model. The temporal percolation concept can be fruitfully applied to study epidemic spreading on temporal networks. We show in particular how the susceptible-infected-removed model on an activity-driven network can be mapped to the percolation problem up to a time given by the spreading rate of the epidemic process. This mapping allows us to obtain additional information on this process, not available for previous approaches. PMID:24730899

Starnini, Michele; Pastor-Satorras, Romualdo

2014-03-01

103

Percolation on general trees and HIV modeling  

NASA Astrophysics Data System (ADS)

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.

Ahmed, E.; Agiza, H. N.

1996-12-01

104

Atmospheric ammonia - Measurements and modeling  

NASA Technical Reports Server (NTRS)

Ammonia possesses a unique position in the terrestrial atmosphere in that it is the only gaseous basic constituent. Ammonia readily forms aerosols, and by virtue of its high solubility controls the pH of cloud droplets and precipitation. Over the past year a ground-based solar viewing Infrared Heterodyne Radiometer has been used at Langley Research Center to infer the vertical distribution of ammonia. Ground level in situ measurements of ammonia have also been obtained to supplement the profile data. The ammonia profiles have been analyzed and interpreted with a one-dimensional photochemical model of the troposphere to assess the sources and sinks of NH3.

Hoell, J. M., Jr.; Levine, J. S.; Augustsson, T. R.; Harward, C. N.

1981-01-01

105

Disinfection of secondary effluents by infiltration percolation.  

PubMed

Among the most attractive applications of reclaimed wastewater are: irrigation of public parks, sports fields, golf courses and market gardening. These uses require advanced wastewater treatment including disinfection. According to WHO guidelines (1989) and current rules and regulations in Tunisia, faecal coliform levels have to be reduced to < 10(3) or 10(2) CFU/100 mL. In Tunisia, most wastewater plants are only secondary treatment and, in order to meet health related regulations, the effluents need to be disinfected. However, it is usual for secondary effluents to need filtration prior to disinfection. Effectiveness of conventional disinfection processes, such as chlorination and UV radiation, are dependent upon the oxidation level and the levels of suspended solids of the treated water. Ozonation is relatively expensive and energy consuming. The consideration of the advantages and disadvantages of conventional techniques, their reliability, investment needs and operational costs will lead to the use of less sophisticated alternative techniques for certain facilities. Among alternative techniques, soil aquifer treatment and infiltration percolation through sand beds have been studied in Arizona, Israel, France, Spain and Morocco. Infiltration percolation plants have been intermittently fed with secondary or high quality primary effluents which percolated through 1.5-2 m unsaturated coarse sand and were recovered by under-drains. In such infiltration percolation facilities, microorganisms were eliminated through numerous physical, physicochemical and biological inter-related processes (mechanical filtration, adsorption and microbial degradation respectively). Efficiency of faecal coliform removal was dependent upon the water detention times in the filtering medium and on the oxidation of the filtered water. Effluents of Sfax town aerated ponds were infiltrated through 1.5 m deep sand columns in order to determine the performance of infiltration percolation in the polishing of secondary effluents. Elimination of bacteria (total and coliforms, faecal streptococci) and their relationship with the hydraulic load and the temperature were investigated. PMID:11464749

Makni, H

2001-01-01

106

Process for co-production of higher alcohols, methanol and ammonia  

Microsoft Academic Search

This patent describes an integrated process for the production of higher alcohols, methanol and ammonia. It comprises: catalytically reforming at first methane-containing stream with steam and carbon dioxide to form first a hydrogen and carbon monoxide-containing synthesis gas; removing carbon dioxide from the first synthesis gas and recycling at least a portion of the carbon dioxide to the reformation; rejecting

N. M. Patel; S. I. Wang

1989-01-01

107

Emissions of Ammonia, Nitrous Oxide and Methane during the Management of Solid Manures  

Microsoft Academic Search

Organic manures arising from livestock production provide a source of plant nutrients when applied to agricultural land. However, only about 52% of the N excreted by livestock is estimated to be recycled as a plant nutrient. The 璯reatest losses of N from livestock excreta and manures are as gaseous emissions. These emissions are in the form of ammonia (NH3), nitrous

J. Webb; S. G. Sommer; T. Kupper; K. Groenestein; N. J. Hutchings; B. Eurich-Menden; L. Rodhe; T. H. Misselbrook; B. Amon

2012-01-01

108

Percolation of a general network of networks  

NASA Astrophysics Data System (ADS)

Percolation theory is an approach to study the vulnerability of a system. We develop an analytical framework and analyze the percolation properties of a network composed of interdependent networks (NetONet). Typically, percolation of a single network shows that the damage in the network due to a failure is a continuous function of the size of the failure, i.e., the fraction of failed nodes. In sharp contrast, in NetONet, due to the cascading failures, the percolation transition may be discontinuous and even a single node failure may lead to an abrupt collapse of the system. We demonstrate our general framework for a NetONet composed of n classic Erd?s-R閚yi (ER) networks, where each network depends on the same number m of other networks, i.e., for a random regular network (RR) formed of interdependent ER networks. The dependency between nodes of different networks is taken as one-to-one correspondence, i.e., a node in one network can depend only on one node in the other network (no-feedback condition). In contrast to a treelike NetONet in which the size of the largest connected cluster (mutual component) depends on n, the loops in the RR NetONet cause the largest connected cluster to depend only on m and the topology of each network but not on n. We also analyzed the extremely vulnerable feedback condition of coupling, where the coupling between nodes of different networks is not one-to-one correspondence. In the case of NetONet formed of ER networks, percolation only exhibits two phases, a second order phase transition and collapse, and no first order percolation transition regime is found in the case of the no-feedback condition. In the case of NetONet composed of RR networks, there exists a first order phase transition when the coupling strength q (fraction of interdependency links) is large and a second order phase transition when q is small. Our insight on the resilience of coupled networks might help in designing robust interdependent systems.

Gao, Jianxi; Buldyrev, Sergey V.; Stanley, H. Eugene; Xu, Xiaoming; Havlin, Shlomo

2013-12-01

109

Oceanic emissions of ammonia  

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

110

Improving ammonia plant production  

Microsoft Academic Search

Investigates the effect of small variations in loop parameters on the production rate for an existing ammonia plant. A 73-psi (503-kPa) step in loop pressure or a 0.1% change in feed inerts or a roughly 7F (4C) step in condensation temperature do correspond to each other in terms of the effect on the production rate. Discusses hydrogen recovery from purge

N. Neth; W. Liebe; H. Puhl

1982-01-01

111

Improving ammonia plant production  

Microsoft Academic Search

In the reported experimental program, for an existing ammonia plant, the effect of small variations in loop parameters on the production rate was investigated. For the plant considered, a 73-psi (503-kPa) step in loop pressure or a 0.1% change in feed inerts or a roughly 7\\/degree\\/F (4\\/degree\\/C) step in condensation temperature do correspond to each other in terms of the

N. Neth; H. Puhl; W. Liebe

1982-01-01

112

Industrial ammonia gassing  

PubMed Central

Walton, M. (1972).British Journal of Industrial Medicine,30, 78-86. Industrial ammonia gassing. Seven cases of ammonia gassing are described with follow-up for five years of the six survivors and the post-mortem findings of the fatal case. All the survivors attributed continuing symptoms to the gassing. The study failed to demonstrate permanent ill effects in the one case of mild exposure. Of the more serious cases one has stopped smoking and taken up physical training teaching. He now has above average lung function. Two serious cases who continued to smoke have the lung function abnormalities expected from their smoking. In the other two seriously exposed cases, who also continued to smoke, there is a persistent reduction in ventilation and gas transfer which seems to be due to the ammonia gassing. The post-mortem findings in the fatal case showed acute congestion and oedema of the mucosa of the respiratory tract, the bronchial walls being stripped of their lining epithelium and the alveoli stuffed with red blood cells and oedema fluid. Images PMID:4685304

Walton, M.

1973-01-01

113

Atmospheric dispersion of ammonia: an ammonia fog model  

SciTech Connect

A simplification to the two-phase ammonia vapor-droplet fog problem has been implemented to study the dispersion of a spill of 40 tons of ammonia. We have circumvented the necessity of adding the partial differential equations for mass, momentum, and energy for the ammonia in the liquid phase by certain assumptions. It is assumed that the ammonia fog behaves as an ideal gas including the droplets. A temperature-dependent molecular weight was introduced to simulate the transition from a vapor-droplet cloud to a pure vapor cloud of ammonia. Likewise, the vaporization of ammonia was spread out over a temperature range. Mass, momentum, energy, and total ammonia is conserved rigorously. The observed features of the ammonia spill simulation have pointed out phenomena that could not be predicted in simpler calculations. Perhaps the most obvious feature is the cloud bifurcation due to the strength of the gravity current relative to the ambient wind. The gravity spreading of the denser ammonia fog significantly perturbs the unidirectional windfield in the vicinity of the spill, setting up complex eddy patterns in the cloud which are enhanced by ground heating and warm dry air entrainment. The lower concentrations appear to lift off by a buoyancy-induced flow. The ammonia cloud, rather than being cigar shaped as assumed in simpler models, ranges from pancake shaped to pear shaped, depending upon the ambient windfield. The fact that the ammonia cloud remains cold, very low, and wide is in qualitative agreement with some of the large-scale ammonia spill accidents. 14 figures.

Kansa, E.J.; Rodean, H.C.; Chan, S.T.; Ermak, D.L.

1983-01-01

114

Bond and site percolation in three dimensions.  

PubMed

We simulate the bond and site percolation models on a simple-cubic lattice with linear sizes up to L=512, and estimate the percolation thresholds to be p(c)(bond)=0.24881182(10) and p(c)(site)=0.3116077(2). By performing extensive simulations at these estimated critical points, we then estimate the critical exponents 1/?=1.1410(15), ?/?=0.47705(15), the leading correction exponent y(i)=-1.2(2), and the shortest-path exponent d(min)=1.3756(3). Various universal amplitudes are also obtained, including wrapping probabilities, ratios associated with the cluster-size distribution, and the excess cluster number. We observe that the leading finite-size corrections in certain wrapping probabilities are governed by an exponent ?-2, rather than y(i)?-1.2. PMID:23767487

Wang, Junfeng; Zhou, Zongzheng; Zhang, Wei; Garoni, Timothy M; Deng, Youjin

2013-05-01

115

Transit time during the interparticle percolation process.  

PubMed

A numerical investigation of jamming effect during the spontaneous interparticle percolation process of small beads through an unconsolidated porous media has been performed. The size ratio between the moving beads and the ones building up the porous medium was chosen larger than the geometrical trapping threshold: ?(c)=(2/?3]-1)(-1)=6.464.... In this paper, we used the discrete element method algorithm to study the rebounds of particles on the top of the porous medium and the transit times of an assembly of particles through it. Several parameters such as the number of injected particles, the size ratio between beads, and the energy restitution coefficient are investigated. This study leads to give some important results of the evolution of the transit time versus the contiguous volume occupied by the percolating particles. PMID:21230267

Lomin, Franck; Oger, Luc

2010-10-01

116

Recycling Service Learning Activity  

NSDL National Science Digital Library

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.

Renee Faatz

117

Rigidity Percolation in Particle-Laden Foams  

NASA Astrophysics Data System (ADS)

We study the viscoelastic behavior of aqueous foam mixed with solid noncolloidal particles. We show that adding a tiny amount of grains can enhance the elastic and loss shear moduli by more than 1 order of magnitude. The scaling of these moduli with solid volume fraction is in qualitative agreement with that predicted by an effective-medium rigidity percolation model. We present a simple model, based on capillary attraction, to explain the particle-size dependence of the threshold.

Cohen-Addad, Sylvie; Krzan, Marcel; H鰄ler, Reinhard; Herzhaft, Benjamin

2007-10-01

118

String percolation and the first LHC data  

E-print Network

The results of string percolation on multiplicities and elliptic flow in AA and pp collisions are compared with LHC data showing a good agreement. We discuss the rapidity long range correlations and its relation to the height and longitudinal extension of the ridge structure. Finally we show that the dependence of the shear viscosity over entropy density ratio on the temperature, presents a minimum close to the critical temperature remaining small in the range of the RHIC and LHC energies.

Irais Bautista; Jorge Dias de Deus; Carlos Pajares

2011-12-21

119

Benchmarking survey for recycling.  

SciTech Connect

This report describes the methodology, analysis and conclusions of a comparison survey of recycling programs at ten Department of Energy sites including Sandia National Laboratories/New Mexico (SNL/NM). The goal of the survey was to compare SNL/NM's recycling performance with that of other federal facilities, and to identify activities and programs that could be implemented at SNL/NM to improve recycling performance.

Marley, Margie Charlotte; Mizner, Jack Harry

2005-06-01

120

Cooperation percolation in spatial prisoner's dilemma game  

NASA Astrophysics Data System (ADS)

The paradox of cooperation among selfish individuals still puzzles scientific communities. Although a large amount of evidence has demonstrated that the cooperator clusters in spatial games are effective in protecting the cooperators against the invasion of defectors, we continue to lack the condition for the formation of a giant cooperator cluster that ensures the prevalence of cooperation in a system. Here, we study the dynamical organization of the 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 the 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, 1 < b < 4/3 leads to a phase transition pertaining to the class of regular site percolation, whereas 3/2 < b < 2 gives rise to a phase transition subject to invasion percolation with trapping. Our findings offer a deeper understanding of cooperative behavior in nature and society.

Yang, Han-Xin; Rong, Zhihai; Wang, Wen-Xu

2014-01-01

121

Percolative phenomena in branched reverse micelles  

NASA Astrophysics Data System (ADS)

The role played by the solvation water molecules on the macroscopically observed sol-gel transition in lecithin/cyclohexane/water reverse micelles is investigated. The self-diffusion properties of both the surfactant and the water molecules entrapped in the micellar cores are investigated by quasi-elastic neutron scattering, while dielectric relaxation and conductivity measurements furnish information on the structural relaxation processes taking place in the system. The obtained results are compared with the experimental indications for AOT/cyclohexane/water systems. The data from lecithin-based systems can be interpreted only by assuming that, contrary to AOT systems, the water molecules are entrapped at the interfaces without coalescing into an inner water pool. Also, the charge transport mechanisms look very different in the two kinds of systems. In particular, in the case of lecithin, it is shown how the conductivity appears mainly due to inter-micellar bond percolation: it is suggested that the solvated water molecules can induce a change of the surface curvature, in such a way promoting the formation of branch points. The idea of the existence of a percolated network of branched cylindrical micelles agrees with the observed temperature dependence of the system conductivity. The study of the electrorheologic behavior of the system under electric field confirms the existence of a percolated transient network in the gel phase.

Aliotta, F.; Fazio, B.

2002-02-01

122

Local Mechanical Fields in Interface Percolated Nanocomposites  

NASA Astrophysics Data System (ADS)

Polymer nanocomposites can enable the innovative design of multi-functional materials. Metallic fillers in polymer matrices can exhibit improved electronic properties at low volume fractions while maintaining the low density, transparency, and easy processing of polymers. Surprisingly, mechanical properties also show enhancement at these uncharacteristically low volume fractions. Two mechanisms have been suggested as contributing to this enhancement. The first is the formation of a percolated microstructure; the second is the significant influence of the interface region between the matrix and filler. The majority of mathematical models describing this novel mechanical behavior are based on percolation models, which only consider microstructural connectivity. Changes in mechanical properties are likely to be affected by complex microstructures, beyond the simply connected, as well as by micromechanical mechanisms associated with these microstructures. These more complex microstructures and mechanisms may be challenging to identify and describe. In this work the underlying mechanical mechanisms are investigated using a probabilistic and statistical characterization of local strain fields. These continuous fields are more amenable to statistical characterization than the spatial ternary (matrix, particle and interface) fields that describe the microstructure. An apparent percolation threshold is identified based on statistical characterization of the elastic moduli, distributions of local strains and spatial autocorrelation of local strain fields. The statistics of strain fields associated with microstructures producing minimum and maximum moduli are also compared.

Burrows, Brian James

123

Percolate or die: Multi-percolation decides the struggle between competing innovations  

E-print Network

Competition is one of the most fundamental phenomena in physics, biology and economics. Recent studies of the competition between innovations have highlighted the influence of switching costs and interaction networks, but the problem is still puzzling. We introduce a model that reveals a novel multi-percolation process, which governs the struggle of innovations trying to penetrate a market. We find that innovations thrive as long as they percolate in a population, and one becomes dominant when it is the only one that percolates. Besides offering a theoretical framework to understand the diffusion of competing innovations in social networks, our results are also relevant to model other problems such as opinion formation, political polarization, survival of languages and the spread of health behavior.

Roca, Carlos P; Helbing, Dirk

2011-01-01

124

Percolation in a Proton Exchange Membrane Fuel Cell Catalyst Layer  

SciTech Connect

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.

Stacy, Stephen; Allen, Jeffrey

2012-07-01

125

Process for removal of ammonia and acid gases from contaminated waters  

DOEpatents

Contaminating basic gases, i.e., ammonia and acid gases, e.g., carbon dioxide, are removed from process waters or waste waters in a combined extraction and stripping process. Ammonia in the form of ammonium ion is extracted by an immiscible organic phase comprising a liquid cation exchange component, especially an organic phosphoric acid derivative, and preferably di-2-ethyl hexyl phosphoric acid, dissolved in an alkyl hydrocarbon, aryl hydrocarbon, higher alcohol, oxygenated hydrocarbon, halogenated hydrocarbon, and mixtures thereof. Concurrently, the acidic gaseous contaminants are stripped from the process or waste waters by stripping with stream, air, nitrogen, or the like. The liquid cation exchange component has the ammonia stripped therefrom by heating, and the component may be recycled to extract additional amounts of ammonia.

King, C.J.; Mackenzie, P.D.

1982-09-03

126

Process for removal of ammonia and acid gases from contaminated waters  

DOEpatents

Contaminating basic gases, i.e., ammonia, and acid gases, e.g., carbon dioxide, are removed from process waters or waste waters in a combined extraction and stripping process. Ammonia in the form of ammonium ion is extracted by an immiscible organic phase comprising a liquid cation exchange component, especially an organic phosphoric acid derivative, and preferably di-2-ethyl hexyl phosphoric acid, dissolved in an alkyl hydrocarbon, aryl hydrocarbon, higher alcohol, oxygenated hydrocarbon, halogenated hydrocarbon, and mixtures thereof. Concurrently, the acidic gaseous contaminants are stripped from the process or waste waters by stripping with steam, air, nitrogen, or the like. The liquid cation exchange component has the ammonia stripped therefrom by heating, and the component may be recycled to extract additional amounts of ammonia.

King, C. Judson (Kensington, CA); MacKenzie, Patricia D. (Berkeley, CA)

1985-01-01

127

27 CFR 21.96 - Ammonia, aqueous.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Ammonia, aqueous. 21.96 Section 21...Specifications for Denaturants 21.96 Ammonia, aqueous. (a) Alkalinity. Strongly alkaline to litmus. (b) Ammonia content. 27 to 30...

2010-04-01

128

27 CFR 21.96 - Ammonia, aqueous.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Ammonia, aqueous. 21.96 Section 21...Specifications for Denaturants 21.96 Ammonia, aqueous. (a) Alkalinity. Strongly alkaline to litmus. (b) Ammonia content. 27 to 30...

2012-04-01

129

21 CFR 573.180 - Anhydrous ammonia.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Anhydrous ammonia. 573.180 Section 573.180 Food and...Additive Listing 573.180 Anhydrous ammonia. (a) The food additive anhydrous ammonia is applied directly to corn plant...

2012-04-01

130

21 CFR 573.180 - Anhydrous ammonia.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 2014-04-01 false Anhydrous ammonia. 573.180 Section 573.180 Food and...Additive Listing 573.180 Anhydrous ammonia. (a) The food additive anhydrous ammonia is applied directly to corn plant...

2014-04-01

131

21 CFR 573.180 - Anhydrous ammonia.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Anhydrous ammonia. 573.180 Section 573.180 Food and...Additive Listing 573.180 Anhydrous ammonia. (a) The food additive anhydrous ammonia is applied directly to corn plant...

2013-04-01

132

21 CFR 573.180 - Anhydrous ammonia.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Anhydrous ammonia. 573.180 Section 573.180 Food and...Additive Listing 573.180 Anhydrous ammonia. (a) The food additive anhydrous ammonia is applied directly to corn plant...

2011-04-01

133

27 CFR 21.96 - Ammonia, aqueous.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Ammonia, aqueous. 21.96 Section 21...Specifications for Denaturants 21.96 Ammonia, aqueous. (a) Alkalinity. Strongly alkaline to litmus. (b) Ammonia content. 27 to 30...

2013-04-01

134

27 CFR 21.96 - Ammonia, aqueous.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 2014-04-01 false Ammonia, aqueous. 21.96 Section 21...Specifications for Denaturants 21.96 Ammonia, aqueous. (a) Alkalinity. Strongly alkaline to litmus. (b) Ammonia content. 27 to 30...

2014-04-01

135

27 CFR 21.96 - Ammonia, aqueous.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Ammonia, aqueous. 21.96 Section 21...Specifications for Denaturants 21.96 Ammonia, aqueous. (a) Alkalinity. Strongly alkaline to litmus. (b) Ammonia content. 27 to 30...

2011-04-01

136

21 CFR 573.180 - Anhydrous ammonia.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Anhydrous ammonia. 573.180 Section 573.180 Food and...Additive Listing 573.180 Anhydrous ammonia. (a) The food additive anhydrous ammonia is applied directly to corn plant...

2010-04-01

137

The influence of nanofiller alignment on transverse percolation and conductivity  

NASA Astrophysics Data System (ADS)

Nanocomposites have unprecedented potential for conductivity-based damage identification when used as matrices in structural composites. Recent research has investigated nanofiller alignment in structural composites, but because damage identification often requires in-plane measurements, percolation and conductivity transverse to the alignment direction become crucial considerations. We herein contribute indispensable guidance to the development of nanocomposites with aligned nanofiller networks and insights into percolation trends transverse to the alignment direction by studying the influence of alignment on transverse critical volume fraction, conductivity, and rate of transition from non-percolating to percolating in three-dimensional carbon nanotube composite systems.

Tallman, T. N.; Wang, K. W.

2015-01-01

138

Correction-to-scaling exponent for two-dimensional percolation  

SciTech Connect

We show that the correction-to-scaling exponents in two-dimensional percolation are bounded by {Omega}{<=}72/91, {omega}=D{Omega}{<=}3/2, and {Delta}{sub 1}={nu}{omega}{<=}2, based upon Cardy's result for the crossing probability on an annulus. The upper bounds are consistent with many previous measurements of site percolation on square and triangular lattices and new measurements for bond percolation, suggesting that they are exact. They also agree with exponents for hulls proposed recently by Aharony and Asikainen, based upon results of den Nijs. A corrections scaling form evidently applicable to site percolation is also found.

Ziff, Robert M. [Center for the Study of Complex Systems and Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)

2011-02-15

139

The influence of nanofiller alignment on transverse percolation and conductivity.  

PubMed

Nanocomposites have unprecedented potential for conductivity-based damage identification when used as matrices in structural composites. Recent research has investigated nanofiller alignment in structural composites, but because damage identification often requires in-plane measurements, percolation and conductivity transverse to the alignment direction become crucial considerations. We herein contribute indispensable guidance to the development of nanocomposites with aligned nanofiller networks and insights into percolation trends transverse to the alignment direction by studying the influence of alignment on transverse critical volume fraction, conductivity, and rate of transition from non-percolating to percolating in three-dimensional carbon nanotube composite systems. PMID:25502606

Tallman, T N; Wang, K W

2015-01-16

140

Recycling into Art  

NSDL National Science Digital Library

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

Debra Fioranelli

2000-10-01

141

Visiting a Recycling Plant  

NSDL National Science Digital Library

In this ZOOM video segment, cast member Francesco follows the paper trail to find out what happens to his recyclables. He visits a material recovery center and learns how paper is recycled and the number of trees that are saved as a result.

2005-10-21

142

Making Recycled Paper  

NSDL National Science Digital Library

This video and accompanying text describe the three-pronged resource conservation strategy known as "reduce, reuse, and recycle". The video segment, adapted from the television program 'ZOOM', features cast members demonstrating how something that might otherwise be discarded, such as newspaper, can be recycled to create a functional or even beneficial new product. Questions for discussion are also provided.

2005-01-01

143

Recycling and Composting  

NSDL National Science Digital Library

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.

2005-01-01

144

Recycling at Camp.  

ERIC Educational Resources Information Center

Outlines a Michigan summer camp's efforts to reduce solid waste disposal by recycling cardboard, tin, glass, aluminum, and plastic milk containers. Points out variables affecting the success of such efforts. Discusses Michigan state funding for the development of recycling programs. (SV)

Cummins, William M.

1988-01-01

145

Advances in plastic recycling. Volume 1: Recycling of polyurethanes  

SciTech Connect

``Recycling of Polyurethanes'', the first volume in the Advances in Plastics Recycling series, is focused on the physical and chemical recycling of polyurethanes, with attention given to energy conversion. A compilation of the present ongoing studies on recycling of urethane and, in general, isocyanate-based polymers, the focus is on thermosetting urethane polymers. Contents include: Recycling of Polyurethane Plastics in the European Automotive Industry; Present State of Polyurethane Recycling in Europe; Processing Overview of Bonded Polyurethane Foam; Mechanical Recycling of Polyurethane Scrap; Ecostream{trademark}--A Technology Beyond Recycling; Recycling of Flexible polyurethane Foam; General purpose Adhesives Prepared from Chemically Recycled Waste Rigid Polyurethane Foams; and Utilization of Isocyanate Binders in Recycling of Scrap Automotive Headliners.

Frisch, K.C.; Klempner, D.; Prentice, G.

1999-07-01

146

Asphalt recycle plant and method  

SciTech Connect

An asphalt recycling system and process are incorporated into an existing batch type asphalt plant. The existing asphalt plant has an aggregate dryer and air discharge ducts connected to a filtering system. A recycling dryer has input ducts connected to the existing aggregate dryer discharge ducts and output ducts connected from the recycling dryer back to the existing ducts to the filtering system. A recycle feeder bin for feeding reclaimed asphalt pavement to the recycle dryer is connected to the recycle dryer. A recycle booster burner is operatively connected to the recycle dryer through the input duct to the dryer for providing additional heat to the recycle dryer so that the waste heat from the existing aggregate dryer and the booster burner provide a predetermined heat to the recycle dryer for heating the asphalt material. A recycling storage bin or silo is connected to receive the heated recycled asphalt from the recycle dryer. A hammermill or other means may be provided for breaking up the old asphaltic materials, such as old paving materials prior to entry of the material into the recycle dryer. Dampers are provided for directing heated gases from the existing batch type asphalt plant to the recycling system, as needed, and temperature controls are utilized to control the recycled booster burner to provide the right combination of existing waste and added heat for the recycled dryer. The stored recycled asphalt materials may be fed to an existing plant batching tower for batching and loading into vehicles.

Brashears, D. F.; Butler, T. G.; Elliott, E. J.

1984-10-16

147

Modeling of heat generation in ammonia-treated solid rocket propellant  

SciTech Connect

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.

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

1995-06-01

148

Equation of state of ammonia  

NASA Astrophysics Data System (ADS)

Ammonia and water are critical components of extraterrestrial bodies, determining the density and physical properties of the Outer Planets, their moons, and of extrasolar planets. Ammonia is unusual in having a high heat capacity relative to other molecular species. Equations of state (EOS) are presented for ammonia and for mixtures of ammonia and water. Their properties are discussed in terms of chemical compositions that evolve as pressure and temperature are varied. The NH4OH hydrate of ammonia is known to exist as a separate molecular species at pressures above about 5 GPa, and an effort was made to include reaction between NH3 and H2O in the mixture EOS. The EOS are suitable for calculating structures of icy planets and exoplanets, and of impacts. mass-radius relations which bound the possible interpretations of composition and structure for extraterrestrial bodies of unknown composition, such as exoplanets.

Mulford, R.; Swift, D. C.; Hamel, S.

2014-05-01

149

Potential Roles of Ammonia in a Hydrogen Economy  

E-print Network

Potential Roles of Ammonia in a Hydrogen Economy A Study of Issues Related to the Use Ammonia..................................................................... 6 II. AMMONIA PROPERTIES......................................................... 6 III. AMMONIA PRODUCTION........................................................ 7 IV. AMMONIA DECOMPOSITION

150

Renal ammonia metabolism and transport.  

PubMed

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

Weiner, I David; Verlander, Jill W

2013-01-01

151

Renal Ammonia Metabolism and Transport  

PubMed Central

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

Weiner, I. David; Verlander, Jill W.

2015-01-01

152

Modied invasion percolation model for fracking  

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

153

Percolation and Deconfinement in SU(2) Gauge Theory  

E-print Network

We show that deconfinement in SU(2) gauge theory can be described by the percolation of site-bond clusters of like-sign Polyakov loops. In particular, we find that in 2+1 dimensions the percolation variables coincide with those of the 2-dimensional Ising model.

S. Fortunato; H. Satz

1999-08-23

154

On directed compact percolation near a damp wall  

Microsoft Academic Search

A percolation probability for directed, compact percolation near a damp wall, which interpolates between the previously examined cases, is derived exactly. We find that the critical exponent beta = 2 in common with the dry wall, rather than the value previously found in the wet wall and bulk cases. The solution is found via a mapping to a particular model

H Lonsdale; R Brak; J W Essam; A L Owczarek; A Rechnitzer

2009-01-01

155

Percolation on bipartite scale-free networks  

NASA Astrophysics Data System (ADS)

Recent studies introduced biased (degree-dependent) edge percolation as a model for failures in real-life systems. In this work, such process is applied to networks consisting of two types of nodes with edges running only between nodes of unlike type. Such bipartite graphs appear in many social networks, for instance in affiliation networks and in sexual-contact networks in which both types of nodes show the scale-free characteristic for the degree distribution. During the depreciation process, an edge between nodes with degrees k and q is retained with a probability proportional to (, where ? is positive so that links between hubs are more prone to failure. The removal process is studied analytically by introducing a generating functions theory. We deduce exact self-consistent equations describing the system at a macroscopic level and discuss the percolation transition. Critical exponents are obtained by exploiting the Fortuin-Kasteleyn construction which provides a link between our model and a limit of the Potts model.

Hooyberghs, H.; Van Schaeybroeck, B.; Indekeu, J. O.

2010-08-01

156

k-Core percolation on multiplex networks  

E-print Network

We generalize the theory of k-core percolation on complex networks to k-core percolation on multiplex networks, where k=(k_a, k_b, ...). Multiplex networks can be defined as networks with a set of vertices but different types of edges, a, b, ..., representing different types of interactions. For such networks, the k-core is defined as the largest sub-graph in which each vertex has at least k_i edges of each type, i = a, b, ... . We derive self-consistency equations to obtain the birth points of the k-cores and their relative sizes for uncorrelated multiplex networks with an arbitrary degree distribution. To clarify our general results, we consider in detail multiplex networks with edges of two types, a and b, and solve the equations in the particular case of ER and scale-free multiplex networks. We find hybrid phase transitions at the emergence points of k-cores except the (1,1)-core for which the transition is continuous. We apply the k-core decomposition algorithm to air-transportation multiplex networks, composed of two layers, and obtain the size of (k_a, k_b)-cores.

N. Azimi-Tafreshi; J. Gomez-Gardenes; S. N. Dorogovtsev

2014-05-06

157

Autophagy and ammonia  

PubMed Central

Autophagy plays an important role in the cellular response to a variety of metabolic stress conditions thus contributing to the maintenance of intracellular homeostasis. Studies in yeast have defined the genetic components involved in the initiation of autophagy as well as the progression through the autophagic cascade. The yeast kinase Atg1 initiates autophagy in response to nutrient limitation in a TOR-dependent manner. The ulk family of genes encodes the mammalian ortholog of yeast Atg1. Our recent work using mouse embryonic fibroblast (MEF) cell lines deficient for both ulk1 and ulk2 has revealed that autophagy induction is more complex in mammals than in yeast. Furthermore, these data confirm the surprising finding that a by-product of amino acid metabolism, ammonia, is a strong inducer of autophagy, as first shown by the Abraham laboratory. PMID:22170154

Cheong, Heesun; Lindsten, Tullia

2012-01-01

158

Ammonia Ice Clouds on Jupiter  

NASA Technical Reports Server (NTRS)

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.

2007-01-01

159

CHERRY: CHECKPOINTED EARLY RESOURCE RECYCLING  

E-print Network

1 2 3 CHERRY: CHECKPOINTED EARLY RESOURCE RECYCLING Jos麓e F. Mart麓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

Torrellas, Josep

160

Anhydrous Ammonia Frost on Titan  

NASA Astrophysics Data System (ADS)

Ammonia has been suggested as a probable source for sustaining Titan's thick nitrogen-dominated atmosphere. Ammonia is believed to be important to maintaining nitrogen in Titan's atmosphere. Ammonia is seen in clouds in the atmospheres of Jupiter and Saturn, but has yet to be detected on any of the satellites. This may be because all forms of NH3 are unstable in the ambient conditions of the satellites surfaces or that its spectral features are altered by other components of the surface, and have not been identified. It has recently been demonstrated[1] that brightening occurs in Titan抯 atmosphere that is transient on the time-scale of months. The spectral shape of the brightening is more consistent with that of the transient apparition of a pure ammonia frost than of an ammonia monohydrate or ammonia dihydrate frost. However, the phase behavior of the ammonia water system has peritectics at compositions of 1:1 and 1:2. These hydrate forms would be expected to dominate if the frost, or the reservoir from which the frost was derived had any water present. Physical mechanisms for producing measurable quanitities of anhydrous ammonia can include chemical dehydration or dehydration of the vapor phase - but it is challenging to store significant quantities of the anhydrous material because of the phase behavior in the solid state. [1] Nelson, R.M., et al. Saturn抯 Titan: Surface Change, Ammonia, and Implications for Atmospheric and Tectonic Activity., Icarus, 199, pp. 429-441, 2009 This work was performed at JPL under contract to NASA

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

2009-12-01

161

The Totem Pole Recycled.  

ERIC Educational Resources Information Center

Presents an activity that integrates science, environmental education, art, and social studies. Students identify and research an endangered species and construct a totem pole depicting the species using a recyclable material. (MDH)

Sewall, Susan Breyer

1991-01-01

162

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 ...

163

Depth distribution of ammonia oxidation rates and ammonia-oxidizer community composition in the Sargasso Sea  

E-print Network

Depth distribution of ammonia oxidation rates and ammonia-oxidizer community composition University, Princeton, New Jersey Abstract Ammonia oxidation rates and ammonia-oxidizer community structure in December 2009. Ammonia oxidation rates, measured from trace additions of 15NHz 4 (12颅18 nmol L21), ranged

Ward, Bess

164

Recyclability Index for Automobiles  

Microsoft Academic Search

A rating system was developed to quantify the environmental impacts of light-duty motor vehicles at the end of their life-cycle based on recyclability, toxic material content and ultimate disposal. Each year, 10-11 million vehicles are retired from service in the United States. The vehicle material not recycled is called automotive shredder residue (ASR). About 4.5 to 5 million tons of

Alexander Tsuji; Yarrow Nelson; Andrew Kean; Samuel A. Vigil

2006-01-01

165

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....

166

Ammonia transport by terrestrial and aquatic insects.  

PubMed

Ammonia, an end product from amino acid and nucleic acid metabolism, is highly toxic for most animals. This review will provide an update on nitrogen metabolism in terrestrial and aquatic insects with emphasis on ammonia generation and transport. Aspects that will be discussed include metabolic pathways of nitrogenous compounds, the origin of ammonia and other nitrogenous waste products, ammonia toxicity, putative ammonia transporters as well as ammonia transport processes known in insects. Ammonia transport mechanisms in the mosquito Aedes aegypti, the tobacco hornworm Manduca sexta and the locust Schistocerca gregaria will be discussed in detail while providing additional, novel data. PMID:22100291

Weihrauch, Dirk; Donini, Andrew; O'Donnell, Michael J

2012-04-01

167

Percolative Transport and Cluster Diffusion Near and Below the Percolation Threshold of a Porous Polymeric Matrix  

Microsoft Academic Search

Purpose牋The purpose of this research was to develop a quantitative mass transport model to describe the release of a drug from a porous inert matrix dosage form near and below the percolation threshold for the system.Methods牋Cumulative release profiles were generated for a series of tablets composed of a binary mixture of varying amounts of non-conducting (poly(vinyl stearate)) and conducting (benzoic

Jayne E. Hastedt; James L. Wright

2006-01-01

168

Percolation exponents and thresholds obtained from the nearly ideal continuum percolation system graphite-boron nitride  

Microsoft Academic Search

Compressed disks made from graphite and, its mechanical but not electrical isomorph, boron nitride as well as graphite-boron nitride powders, undergoing compression, are nearly ideal continuum percolation systems, as the ratio of their conductivities is nearly 10-18 and the scatter of the experimental points near the critical volume fraction phic is very small. The following measurements, with the characteristic exponent(s)

Junjie Wu; D. S. McLachlan

1997-01-01

169

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

PubMed Central

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

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

2014-01-01

170

Percolation and permeability of heterogeneous fracture networks  

NASA Astrophysics Data System (ADS)

Natural fracture fields are almost necessarily heterogeneous with a fracture density varying with space. Two classes of variations are quite frequent. In the first one, the fracture density is decreasing from a given surface; the fracture density is usually (but not always see [1]) an exponential function of depth as it has been shown by many measurements. Another important example of such an exponential decrease consists of the Excavated Damaged Zone (EDZ) which is created by the excavation process of a gallery [2,3]. In the second one, the fracture density undergoes some local random variations around an average value. This presentation is mostly focused on the first class and numerical samples are generated with an exponentially decreasing density from a given plane surface. Their percolation status and hydraulic transmissivity can be calculated by the numerical codes which are detailed in [4]. Percolation is determined by a pseudo diffusion algorithm. Flow determination necessitates the meshing of the fracture networks and the discretisation of the Darcy equation by a finite volume technique; the resulting linear system is solved by a conjugate gradient algorithm. Only the flow properties of the EDZ along the directions which are parallel to the wall are of interest when a pressure gradient parallel to the wall is applied. The transmissivity T which relates the total flow rate per unit width Q along the wall through the whole fractured medium to the pressure gradient grad p, is defined by Q = - T grad p/mu where mu is the fluid viscosity. The percolation status and hydraulic transmissivity are systematically determined for a wide range of decay lengths and anisotropy parameters. They can be modeled by comparison with anisotropic fracture networks with a constant density. A heuristic power-law model is proposed which accurately describes the results for the percolation threshold over the whole investigated range of heterogeneity and anisotropy. Then, the data for transmissivity are presented. A simple parallel flow model is introduced. The flow properties of the medium vary with the distance z from the wall. However, the macroscopic pressure gradient does not depend on z, and the flow lines are in average parallel to the wall. Hence, the overall transmissivity is tentatively estimated by a parallel flow model, where a layer at depth z behaves as a fractured medium with uniform properties corresponding to the state at this position in the medium. It yields an explicit analytical expression for the transmissivity as a function of the heterogeneity and anisotropy parameters, and it successfully accounts for all the numerical data. Graphical tools are provided from which first estimates can be quickly and easily obtained. A short overview of the second class of heterogeneous media will be given. [1] Barton C.A., Zoback M.D., J. Geophys. Res., 97B, 5181-5200 (1992). [2] Bossart P. et al, Eng. Geol., vol. 66, 19-38 (2002). [3] Thovert J.-F. et al, Eng. Geol., 117, 39-51 (2011). [4] Adler P.M. et al, Fractured porous media, Oxford U. Press, 2012.

Adler, Pierre; Mourzenko, Valeri; Thovert, Jean-Fran鏾is

2013-04-01

171

Mono-fermentation of chicken manure: Ammonia inhibition and recirculation of the digestate.  

PubMed

The effects of ammonia concentration on the performance and stability of mono-fermentation of chicken manure were investigated in a lab-scale continuous stirred tank reactor at 40癈. Technical stripping was performed to remove ammonia from the liquid fraction of digestate, and the entire product was recycled to the fermenter to control ammonia concentration in the fermenter. Organic loading rate (OLR) of 5.3gVS/(Ld) was achieved with an average free ammonia nitrogen (FAN) concentration of 0.77g/L and a specific gas yield of 0.39L/gVS. When OLR was increased to 6.0gVS/(Ld), stable operation could be obtained with an average FAN concentration of 0.86g/L and a specific gas yield of 0.27L/gVS. Mono-fermentation of chicken manure was successfully carried out at high ammonia concentrations. Controlled recirculation of treated liquid fraction of digestate could be a solution in large-scale application for both: to avoid ammonia inhibition and minimize digestate. PMID:25266688

Nie, Hong; Jacobi, H Fabian; Strach, Katrin; Xu, Chunming; Zhou, Hongjun; Liebetrau, Jan

2015-02-01

172

LETTER TO THE EDITOR: Percolation with multiple giant clusters  

NASA Astrophysics Data System (ADS)

We study mean-field percolation with freezing. Specifically, we consider cluster formation via two competing processes: irreversible aggregation and freezing. We find that when the freezing rate exceeds a certain threshold, the percolation transition is suppressed. Below this threshold, the system undergoes a series of percolation transitions with multiple giant clusters ('gels') formed. Giant clusters are not self-averaging as their total number and their sizes fluctuate from realization to realization. The size distribution Fk, of frozen clusters of size k, has a universal tail, Fk ~ k-3. We propose freezing as a practical mechanism for controlling the gel size.

Ben-Naim, E.; Krapivsky, P. L.

2005-06-01

173

MEASUREMENT OF AMMONIA RELEASE FROM SALTSTONE  

SciTech Connect

SRNL was requested by WSRC Waste Solidification Engineering to characterize the release of ammonia from saltstone curing at 95 C by performing experimental testing. These tests were performed with an MCU-type Tank 50H salt simulant containing 0, 50, and 200 mg/L ammonia. The testing program showed that above saltstone made from the 200 mg/L ammonia simulant, the vapor space ammonia concentration was about 2.7 mg/L vapor at 95 C. An upper 95% confidence value for this concentration was found to be 3.9 mg/L. Testing also showed that ammonia was chemically generated from curing saltstone at 95 C; the amount of ammonia generated was estimated to be equivalent to 121 mg/L additional ammonia in the salt solution feed. Even with chemical generation, the ammonia release from saltstone was found to be lower than its release from salt solution only with 200 mg/L ammonia.

Zamecnik, J; Alex Cozzi, A

2009-01-15

174

Who owns the recyclables  

SciTech Connect

On March 31, the California Supreme Court decided the much awaited Rancho Mirage'' case (Waste Management of the Desert, Inc., and the City of Rancho Mirage v. Palm Springs Recycling Center, Inc.), and held that the California Integrated Waste Management Act of 1989 does not allow an exclusive franchise for the collection of recyclables not discarded by their owner.'' This ends a three-year slugfest between secondary materials processors in the state and municipalities and their franchised garbage haulers who also collect and process recyclables as part of their exclusive arrangement. Central to this nationally-watched litigation is a most fundamental question in waste management: at what point in time do articles in the solid waste stream become actual or potentially valuable secondary materials

Parker, B.

1994-05-01

175

Scrap tire recycling  

SciTech Connect

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.

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

1997-03-01

176

Interorgan ammonia metabolism in liver failure.  

PubMed

In the post-absorptive state, ammonia is produced in equal amounts in the small and large bowel. Small intestinal synthesis of ammonia is related to amino acid breakdown, whereas large bowel ammonia production is caused by bacterial breakdown of amino acids and urea. The contribution of the gut to the hyperammonemic state observed during liver failure is mainly due to portacaval shunting and not the result of changes in the metabolism of ammonia in the gut. Patients with liver disease have reduced urea synthesis capacity and reduced peri-venous glutamine synthesis capacity, resulting in reduced capacity to detoxify ammonia in the liver. The kidneys produce ammonia but adapt to liver failure in experimental portacaval shunting by reducing ammonia release into the systemic circulation. The kidneys have the ability to switch from net ammonia production to net ammonia excretion, which is beneficial for the hyperammonemic patient. Data in experimental animals suggest that the kidneys could have a major role in post-feeding and post-haemorrhagic hyperammonemia.During hyperammonemia, muscle takes up ammonia and plays a major role in (temporarily) detoxifying ammonia to glutamine. Net uptake of ammonia by the brain occurs in patients and experimental animals with acute and chronic liver failure. Concomitant release of glutamine has been demonstrated in experimental animals, together with large increases of the cerebral cortex ammonia and glutamine concentrations. In this review we will discuss interorgan trafficking of ammonia during acute and chronic liver failure. Interorgan glutamine metabolism is also briefly discussed, since glutamine synthesis from glutamate and ammonia is an important alternative pathway of ammonia detoxification. The main ammonia producing organs are the intestines and the kidneys, whereas the major ammonia consuming organs are the liver and the muscle. PMID:12020618

Olde Damink, Steven W M; Deutz, Nicolaas E P; Dejong, Cornelis H C; Soeters, Peter B; Jalan, Rajiv

2002-01-01

177

Global Seabird Ammonia Emissions  

NASA Astrophysics Data System (ADS)

Seabird colonies represent a major source of atmospheric ammonia (NH3) in remote coastal and marine systems in temperate, tropical and polar regions. Previous studies have shown that NH3 emissions from Scottish seabird colonies were substantial - of similar magnitude to the most intensive agricultural point source emissions. The UK data were used to model global seabird NH3 emissions and suggested that penguins are a major source of emissions on and around the Antarctic continent. The largest seabird colonies are in the order of millions of seabirds. Due to the isolation of these colonies from anthropogenic nitrogen sources, they may play a major role in the nitrogen cycle within these ecosystems. A global seabird database was constructed and used in conjunction with a species-specific seabird bioenergetics model to map the locations of NH3 emissions from seabird colonies. The accuracy of the modelled emissions was validated with field data of NH3 emissions measured at key seabird colonies in different climatic regions of the world: temperate (Isle of May, Scotland), tropical (Ascension Island) and polar (Signy Island, South Georgia). The field data indicated good agreement between modelled and measured NH3 emissions. The measured NH3 emissions also showed the variability of emission with climate. Climate dependence of seabird NH3 emissions may have further implications under a changing global climate. Seabird colonies represent NH3 emission 慼otspots, often far from anthropogenic sources, and are likely to be the major source of nitrogen input to these remote coastal ecosystems. The direct manuring by seabirds at colony locations may strongly influence species richness and biodiversity. The subsequent volatilisation and deposition of NH3 increases the spatial extent of seabird influence on nitrogen cycling in their local ecosystem. As many seabird populations are fluctuating due to changing food supply, climate change or anthropogenic pressures, these factors may have far reaching impact on the supply of nitrogen from seabird colonies to their current local ecosystems.

Riddick, S. N.; Blackall, T. D.; Dragosits, U.; Daunt, F. H.; Braban, C. F.; Tang, Y. S.; Trathan, P.; Wanless, S.; Sutton, M. A.

2010-12-01

178

Recycled Aluminum Ornaments  

NSDL National Science Digital Library

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.

Wishart, Ray

2013-06-14

179

The glue-ball spectrum of pure percolation  

E-print Network

We present a high-precision numerical study of 3D random percolation viewed as a confining gauge theory. Using large correlation matrices among multiform Wilson loops we determine the low-lying masses in various spin channels.

Stefano Lottini; Ferdinando Gliozzi

2005-10-05

180

Percolation renormalisation and simulation studies of the potts model  

NASA Astrophysics Data System (ADS)

Based on the connection between the q-state Potts model (QPM) and the q-state bond-correlated percolation (QBCPM), Hu proposed a percolation renormalisation group method (PRGM) and Swendsen and Wang proposed a percolation Monte-Carlo simulation method (PMCSM) for studying properties of the QPM. The PRGM gives the exact free energy and the critical exponent for the one-dimensional QPM and the accurate free energy and critical physical quantities for the suare lattice QPM. The PMCSM and multiple labeling technique are applied to calculate the percolation probability, the mean cluster-size, the average number of occupied bonds, and the fluctuations of the number of bonds for the QBCPM on the square and simple cubic lattices. From such results, we obtain accurate phase transition points for the QPM.

Hu, Chin-Kun; Mak, Kitsing; Chen, Chi-Ning

1988-09-01

181

Percolation transition in networks with degree-degree correlation  

NASA Astrophysics Data System (ADS)

We introduce an exponential random graph model for networks with a fixed degree distribution and a tunable degree-degree correlation. We then investigate the nature of the percolation transition in a correlated network with a Poisson degree distribution. It is found that negative correlation is irrelevant in that the percolation transition in the disassortative network belongs to the same universality class as in the uncorrelated network. Positive correlation turns out to be relevant. The percolation transition in the assortative network is characterized by the nondiverging mean size of finite clusters and power-law scalings of the density of the largest cluster and the cluster size distribution in the nonpercolating phase as well as at the critical point. Our results suggest that the unusual type of percolation transition in the growing network models reported recently may be inherited from the assortative degree-degree correlation.

Noh, Jae Dong

2007-08-01

182

Tricolor percolation and random paths in 3D  

E-print Network

We study "tricolor percolation" on the regular tessellation of R[superscript 3] by truncated octahedra, which is the three-dimensional analog of the hexagonal tiling of the plane. We independently assign one of three colors ...

Yadin, Ariel

183

Gate control of percolative conduction in strongly correlated manganite films.  

PubMed

Gate control of percolative conduction in a phase-separated manganite system is demonstrated in a field-effect transistor geometry, resulting in ambipolar switching from a metallic state to an insulating state. PMID:24481897

Hatano, Takafumi; Sheng, Zhigao; Nakamura, Masao; Nakano, Masaki; Kawasaki, Masashi; Iwasa, Yoshihiro; Tokura, Yoshinori

2014-05-01

184

Direct measurement of recycle ratios in internal recycle laboratory reactors  

Microsoft Academic Search

A method involving the internal positioning of probe capillaries to measure the recycle ratio in an internal recycle reactor equipped with a basket containing a powdered catalyst is reported. The variation of recycle ratio with carrier gas composition, pressure, temperature and catalyst mass is presented. Based on the calculated pressure drop and the principles governing flow resistance across the catalyst

Roald Brosius; Jack C. Q. Fletcher

2010-01-01

185

Recycling Decisions and Green Design.  

ERIC Educational Resources Information Center

Explores the facts and perceptions regarding recycling, what can be done to make products more environmentally compatible, and how to think about recycling decisions in a more helpful way. (Contains 39 references.) (MDH)

Lave, Lester B.; And Others

1994-01-01

186

Phase Diagram of Inhomogeneous Percolation with a Defect Plane  

NASA Astrophysics Data System (ADS)

Let be the -dimensional hypercubic lattice and let be an -dimensional sublattice, with . We consider a model of inhomogeneous bond percolation on at densities and , in which edges in are open with probability , and edges in open with probability . We generalize several classical results of (homogeneous) bond percolation to this inhomogeneous model. The phase diagram of the model is presented, and it is shown that there is a subcritical regime for and (where is the critical probability for homogeneous percolation in ), a bulk supercritical regime for , and a surface supercritical regime for and . We show that is a strictly decreasing function for , with a jump discontinuity at . We extend the Aizenman-Barsky differential inequalities for homogeneous percolation to the inhomogeneous model and use them to prove that the susceptibility is finite inside the subcritical phase. We prove that the cluster size distribution decays exponentially in the subcritical phase, and sub-exponentially in the supercritical phases. For a model of lattice animals with a defect plane, the free energy is related to functions of the inhomogeneous percolation model, and we show how the percolation transition implies a non-analyticity in the free energy of the animal model. Finally, we present simulation estimates of the critical curve.

Iliev, G. K.; Janse van Rensburg, E. J.; Madras, N.

2015-01-01

187

Recycled Insect Models  

ERIC Educational Resources Information Center

This article presents an engaging activity in which high school students use a dichotomous key to guide the creation and classification of model insects from recycled plastic lids and containers. Besides teaching the use of a dichotomous key and the effect of evolutionary descent upon groupings of organisms, this activity focuses on an

Rule, Audrey C.; Meyer, Mary Ann

2007-01-01

188

Recycling for radio astronomy  

NASA Astrophysics Data System (ADS)

Melvin Hoare, Steve Rawlings and the CUGA consortium look forward to the potential offered by recycling the 30 m class antennas at Goonhilly Earth Station in Cornwall, including a new deep-space tracking facility, research and training, and the possibility of enhancing the e-MERLIN array.

Hoare, Melvin

2012-02-01

189

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...

190

Microwave assisted Platinum recycling  

Microsoft Academic Search

Purification of recycled platinum is a multi-step process of repeated dissolving of the scrap metal, precipitation of Platinum salts and thermal treatment of the salts to obtain a pure metal. As a new process, microwave heating is applied for dissolving platinum as well as for decomposition of the Pt-salts into sponge Platinum metal. The goal of microwave heating is reduction

M. A. Willert-Porada; T. Gerdes; A. Schmidt

2011-01-01

191

Designing for recycling  

SciTech Connect

The instrument panel (IP) with its variety of materials is one of the most difficult parts of the automobile to recycle. Selection of materials to minimize material count and maximize separability is critical to cost-effective IP recycling. Choices of assembly and disassembly techniques also should consider recycling. Current practices for recycling automobiles focus on the recovery of usable parts and metals with other materials becoming landfill. New design practices or significant developments in recovery technology must occur to reduce the volume of landfill materials. Design practices will be most effective if they allow cost-effective recovery of desired materials from the plastic components before shredding. Recovery technology continues to improve, but most parts are shredded with the car and land-filled as automotive shredder residue (ASR). Shredding followed by mechanical separation conceptually is the most cost-effective option, but the typical instrument panel contains six or more plastic materials. This makes separation difficult and expensive to get acceptable material yields and purity.

NONE

1997-08-01

192

MITI projects on recycling  

Microsoft Academic Search

MITI has actively done R&D on industrial technology for waste and reclamation and so there are many research items from small scale to large scale. However, Ecofactory and researches on recycling of metallic materials are introduced here. Ecofactory was proposed by the Mechanical Engineering Laboratory and is now at the stage of the Leading Research, a new research scheme in

Yoshinori Nakazawa

1995-01-01

193

Recycling Study Guide.  

ERIC Educational Resources Information Center

This study guide was designed to help teachers and students understand the problems surrounding solid wastes. It includes an overview of solid waste and recycling, a glossary, suggested activities and a list of resource publications, audiovisual materials and organizations. There are 19 activity suggestions included in this guide designed for use

Hallowell, Anne; And Others

194

Reduce, Reuse, and Recycle  

NSDL National Science Digital Library

Boys and girls, grab your nose-plugs because today we are going to be digging through some garbage! We use a lot of garbage; the average American throws away nearly four pounds everyday. That\\'s a whopping 1,600 pounds a year! That means that every year, EACH one of you toss enough trash to equal the weight of all the students in our class...COMBINED! That\\'s a lot of garbage. Our world is big, but you might not have realized just how small it really is when it comes to holding all this trash. Would you want garbage in your backyard? Your playground? The park? There\\'s only so many places to store our waste. So, what do we do? We RECYCLE! What Does It Mean To Recycle? Recycling is taking things we use and would normally through into the trash can and putting them in a separate container. Instead of going to the dump, it goes to a recycling plant. Things like paper, newspaper, cardboard, plastic, glass, and aluminum are all products ...

Nicole

2008-11-19

195

Recycling and Restoration  

NSDL National Science Digital Library

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.

Ket

2011-01-11

196

Recycling refuse into energy  

Microsoft Academic Search

Some 50 percent of large cities and 10 percent of small ones reportedly are talking about recycling their municipal refuse. Several are building facilities or have recently begun operations. Short case histories are given of a few of the more notable ones, including Ames, Iowa (the organic fraction of whose refuse helps fuel the furnace at the municipal electric generating

Godfey; K. A. Jr

1976-01-01

197

Recycling Behavior: A Multidimensional Approach  

ERIC Educational Resources Information Center

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

Meneses, Gonzalo Diaz; Palacio, Asuncion Beerli

2005-01-01

198

Recycling of the #5 polymer.  

PubMed

Polypropylene (PP) is a widely used plastic with consumer applications ranging from food packaging to automotive parts, including car battery casings. To differentiate it from other recyclable plastics, it is designated as #5. Here, the factors contributing to PP recycling rates are briefly reviewed. Considerations include collection and separation efficiency, processing chemistry, and market dynamics for the products derived from recyclates. PMID:22879510

Xanthos, Marino

2012-08-10

199

Molecular Mechanisms of Renal Ammonia Transport  

PubMed Central

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

Weiner, I. David; Hamm, L. Lee

2015-01-01

200

Refrigerator recycling and CFCs  

SciTech Connect

Utility-sponsored refrigerator and freezer pick-up programs have removed almost 900,000 inefficient appliances from the North American electric grid to date. While the CFC-12 refrigerant from the discarded appliances is typically removed and recycled, in all but a few programs the CFC-11 in the foam insulation is not. About a quarter-billion pounds of CFC-11 are banked in refrigerator foam in the United States. Release of this ``bank`` of CFC, combined with that from foam insulation used in buildings, will be the largest source of future emissions if preventive measures are not taken. Methods exist to recover the CFC for reuse or to destroy it by incineration. The task of recycling or destroying the CFCs and other materials from millions of refrigerators is a daunting challenge, but one in which utilities can play a leadership role. E Source believes that utilities can profitably serve as the catalyst for public-private partnerships that deliver comprehensive refrigerator recycling. Rather than treating such efforts solely as a DSM resource acquisition, utilities could position these programs as a multifaceted service delivery that offers convenient appliance removal for homeowners, a solid waste minimization service for landfills, a source of recycled materials for industry, and a CFC recovery and/or disposal service in support of the HVAC industry and society`s atmospheric protection goals and laws. Financial mechanisms could be developed through these public-private enterprises to ensure that utilities are compensated for the extra cost of fully recycling refrigerators, including the foam CFC.

Shepard, M.; Hawthorne, W.; Wilson, A.

1994-12-31

201

First Passage Percolation on Inhomogeneous Random Graphs  

E-print Network

This paper investigates first passage percolation (FPP) on inhomogeneous random graphs (IHRG). The random graph model $G(n,\\kappa)$ we first study is the so-called finite type case of the general model introduced by Bollob\\'as, Janson and Riordan. Each edge of $G(n,\\kappa)$ is given an independent exponential edge weight with rate 1. Our main assumption is that the average number of neighbors $\\wla_n+1$ of each vertex is independent of its type. We consider the cases where $\\wla_n\\to\\wla$ is finite or infinite. Afterwards the general model is also considered. The paper can be considered a generalization of the work of Bhamidi, van der Hofstad and Hooghimstra, where FPP is explored on the Erd\\H{o}s-R\\'enyi random graphs, a special case where all the vertices are of the same type. We find analogous results for the minimal weight of the path between uniformly chosen vertices in the giant component and for the hopcount, i.e. the number of edges on this minimal weight path. The proofs make use of a direct relation...

Kolossv醨y, Istv醤

2012-01-01

202

Two exactly soluble models of rigidity percolation  

PubMed Central

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 憁ean 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

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

2014-01-01

203

Two exactly soluble models of rigidity percolation.  

PubMed

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 =4.41, which is above the 'mean field' value =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 =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

Thorpe, M F; Stinchcombe, R B

2014-02-13

204

Porous silicon ammonia gas sensor  

NASA Astrophysics Data System (ADS)

A planar optical waveguide is manufactured by the functionnalisation of oxidised mesoporous silicon with Bromothymol Blue to achieve a sensitive ammonia sensor suitable for low gas concentrations. The propagated light intensity is measured at the output of the waveguide. The sensitivity at low concentrations and the short time of reaction of the sensor are enhanced by a confinement effect of the gas molecules inside the pores. The dependence of the output signal with gas concentration is demonstrated. When the ammonia flow is stopped, the reversibility of the initial characteristics of the propagated light is naturally obtained with the disappearance of the gas molecules.

Chaillou, A.; Charrier, J.; Lorrain, N.; Sarret, M.; Haji, L.

2006-04-01

205

Characterization of atmospheric ammonia near Fort Worth, TX Part I. Dynamics of gaseous ammonia  

E-print Network

1 Characterization of atmospheric ammonia near Fort Worth, TX 颅 Part I. Dynamics of gaseous ammonia The present work reports the experimental results from the first field investigation of2 atmospheric ammonia its potential effects on the20 local and regional air quality.21 Keywords: ammonia, air quality

206

Ammonia permeability of a cellulose acetate membrane  

Microsoft Academic Search

A mechanism is proposed for ammonia transport across a cellulose acetate membrane. The transport is shown to have a sorption\\u000a character, with the formation of hydrogen bonds between ammonia molecules and the polymer. Our experiments demonstrate that\\u000a the membrane can be regenerated in the course of gas separation. The ideal separation factors in the ammonia-nitrogen and\\u000a ammonia-hydrogen systems are determined.

I. V. Vorotyntsev; P. N. Drozdov; N. V. Karyakin

2006-01-01

207

46 CFR 154.1760 - Liquid ammonia.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Liquid ammonia. 154.1760 Section 154.1760 ...Operating Requirements 154.1760 Liquid ammonia. The master shall ensure that no person sprays liquid ammonia into a cargo tank containing more...

2011-10-01

208

Ammonia Treatment Instructions Page 1 of 5  

E-print Network

Ammonia Treatment Instructions Page 1 of 5 Original version by Douglas Call Updated January 21 has a gas cylinder with 5% Ammonia in Helium (150 ft3 ) stored in 102 Fenske where treatment session). IMPORTANT: Check the gas pressure in the Ammonia and Argon cylinders before you begin

209

46 CFR 154.1760 - Liquid ammonia.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Liquid ammonia. 154.1760 Section 154.1760 ...Operating Requirements 154.1760 Liquid ammonia. The master shall ensure that no person sprays liquid ammonia into a cargo tank containing more...

2012-10-01

210

46 CFR 154.1760 - Liquid ammonia.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Liquid ammonia. 154.1760 Section 154.1760 ...Operating Requirements 154.1760 Liquid ammonia. The master shall ensure that no person sprays liquid ammonia into a cargo tank containing more...

2013-10-01

211

7, 1413914169, 2007 Ammonia at Blodgett  

E-print Network

ACPD 7, 14139颅14169, 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 D颅14169, 2007 Ammonia at Blodgett Forest M. L. Fischer and D. Littlejohn Title Page Abstract Introduction

Paris-Sud XI, Universit茅 de

212

Hydrogen Storage in Ammonia and Aminoborane Complexes  

E-print Network

Hydrogen Storage in Ammonia and Aminoborane Complexes Ali Raissi Florida Solar Energy Center;Advantages of Ammonia Costs about $150 per short ton or less than $6.25 per million BTU of H2 contained for final hydrogen purification stage #12;Disadvantages of Ammonia Requires sub-ambient T and/or elevated P

213

46 CFR 154.1760 - Liquid ammonia.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Liquid ammonia. 154.1760 Section 154.1760 ...Operating Requirements 154.1760 Liquid ammonia. The master shall ensure that no person sprays liquid ammonia into a cargo tank containing more...

2010-10-01

214

8, 54135436, 2008 Ammonia in sulfuric  

E-print Network

ACPD 8, 5413颅5436, 2008 Ammonia in sulfuric acid ion induced nucleation I. K. Ortega et al. Title.0 License. Atmospheric Chemistry and Physics Discussions The role of ammonia in sulfuric acid ion induced颅5436, 2008 Ammonia in sulfuric acid ion induced nucleation I. K. Ortega et al. Title Page Abstract

Boyer, Edmond

215

AMBIENT AMMONIA MEASUREMENTS IN COASTAL SOUTHEASTERN VIRGINIA  

EPA Science Inventory

Results are presented from a measurement program to test an in situ ammonia measurement technique and to document the temporal and spatial variability associated with ammonia. The ammonia data were accumulated for two sites in coastal Southeastern Virginia from 15 Aug. 1979 to 31...

216

AMMONIA CONCENTRATIONS IN PINK SALMON, ONCORHYNCHUS GORBUSCHA,  

E-print Network

AMMONIA CONCENTRATIONS IN PINK SALMON, ONCORHYNCHUS GORBUSCHA, REDDS OF SASHIN CREEK, SOUTHEASTERN ALASKA Although the toxic effects of ammonia have been observed in developing salmonids in hatcheries during and after the run of pink salmon, Oncorhynchus gorbuscha. Ammonia levels increased significantly

217

46 CFR 154.1760 - Liquid ammonia.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 2014-10-01 false Liquid ammonia. 154.1760 Section 154.1760 ...Operating Requirements 154.1760 Liquid ammonia. The master shall ensure that no person sprays liquid ammonia into a cargo tank containing more...

2014-10-01

218

Ammonia metabolism in Aedes aegypti.  

PubMed

We investigated the mechanisms by which Aedes aegypti mosquitoes are able to metabolize ammonia. When females were given access to solutions containing NH(4)Cl or to a blood meal, hemolymph glutamine and proline concentrations increased markedly, indicating that ammonium/ammonia can be removed from the body through the synthesis of these two amino acids. The importance of glutamine synthetase was shown when an inhibitor of the enzyme was added to the meal causing the glutamine concentration in hemolymph to decrease significantly, while the proline concentration increased dramatically. Unexpectedly, we found an important role for glutamate synthase. When mosquitoes were fed azaserine, an inhibitor of glutamate synthase, the glutamine concentration increased and the proline concentration decreased significantly. This confirms the presence of glutamate synthase in mosquitoes and suggests that this enzyme contributes to the production of glutamate for proline synthesis. Several key enzymes related to ammonium/ammonia metabolism showed activity in homogenates of mosquito fat body and midgut. The mosquito genes encoding glutamate dehydrogenase, glutamine synthetase, glutamate synthase, pyrroline-5-carboxylate synthase were cloned and sequenced. The mRNA expression patterns of these genes were examined by a real-time RT-PCR in fat body and midgut. The results show that female mosquitoes have evolved efficient mechanisms to detoxify large loads of ammonium/ammonia. PMID:15804581

Scaraffia, Patricia Y; Isoe, Jun; Murillo, Adrian; Wells, Michael A

2005-05-01

219

Interaction between a percolation network and a cubic cavity  

NASA Astrophysics Data System (ADS)

The intersection between a percolating network of fractures modeled as polygonal surfaces and a cubic cavity is important for the safe storage of wastes in a fractured medium. It is important that the cavities where the wastes are stored do not intersect the percolating network of fractures which may exist, or that these cavities do not enable a fracture network to percolate. Of course, these considerations are particularly important for nuclear wastes. The fractures are hexagons inscribed in a circle of radius R. The hexagons are uniformly distributed in space and isotropically oriented. Let N_{fr} be the number of fractures generated in a finite cubic unit cell Omega of size L^3. The fracture density is the number of fractures per unit volume. It is efficient to analyze the percolation properties of a network by using the dimensionless density rho ' which is the number of fractures per excluded volume. For hexagons, one has rho ' = 7.8 rho R^3. The percolation threshold rho '_c of networks is close to 2.3. More details are given in [1]. In addition, a cubic cavity C formed by six squares inscribed in a circle of radius R_s is generated with its center randomly located in Omega. The three dimensional lengths L, R, and R_s define two dimensionless lengths L' = L/R , R' _s = R_s/R which govern the problem together with rho'. Percolation properties are analyzed as detailed in [1]. Spatially periodic networks are generated with spatially periodic boundary conditions. For a given set of the three dimensionless parameters rho', R'_s and L', N independent networks are generated. In most cases, except for L'=40, N is equal to 500. Among these N networks, N_p percolate and N_{np} do not percolate. When a percolating cluster is obtained, the cavity intersects one or more fractures in N_{rc} realizations; in the same conditions, it does not intersect the cavity in N_{nrc} realizations. An additional case should be considered. When the network does not percolate, the network composed of the hexagons and of the six squares surrounding the cavity may percolate. Let us denote by N_{npc} the number of such events. These quantities and the corresponding probabilities were systematically calculated as functions of the three dimensionless parameters. An important quantity is the conditional probability Pi_c 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 the fracture dimensionless density and of the dimensionless cavity size R' _s. The probability Pi that and 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 easily obtained for a cube. This prediction is shown to be in good agreement with the conditional probability Pi_c for large densities rho' or small R_s. However, it should be noted that these probabilities 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. [1] Adler et al, Fractured porous media, Oxford U. Press, in press.

Thovert, J.; Sangar, D.; Mourzenko, V.; Adler, P. M.

2012-12-01

220

COPPER CABLE RECYCLING TECHNOLOGY  

SciTech Connect

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.

Chelsea Hubbard

2001-05-01

221

Composting to Recycle Biowaste  

Microsoft Academic Search

\\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

Gy鰎gy F黮eky; Szilveszter Benedek

222

Machine coolant recycling system  

SciTech Connect

Machining processes at the 272W Site Fabrication Services (SFS) produce a waste stream consisting of dirty machine coolant. During use the coolant becomes contaminated with metal chips from milling, and oil, dirt and solvents from the machining process. The mixture is designated as a Washington State dangerous waste with WP02 (persistence), D007 (chromium) and D008 (lead) waste codes. This process results in the generation of 13.5 m{sup 3} of hazardous waste per year with an annual cost for coolant replacement, waste management and waste disposal of approximately $137,000. To identify alternatives to this situation, ICF Kaiser Hanford Company (ICF KH) North Environmental Services conducted a pollution prevention opportunity assessment (P20A) on the machining processes. A coolant recycler and sump sucker unit were selected as the most cost-effective waste reduction options. In December 1994, ICF KH received return on investment (ROI) funding from the U.S. Department of Energy Richland Operations Office (DOE-RL) to implement this option. The coolant recycling and the sump sucker units were purchased and installed in July 1995 at a total cost of $61,000. The sump sucker removes the dirty coolant from the fabrication machinery and filters it to remove shavings and sludge. The filtered coolant then is transferred to the coolant recycling system for further processing. The coolant recycling system reconditions the filtered coolant for use in the machining equipment, and mixes the concentrated coolant to the correct concentration. As a result of implementing this option, the annual generation of waste coolant was reduced by 12 m{sup 3}. The annual cost savings exceed $119,000 with an ROI of 186%. Additional benefits include reduced coolant usage; improved tool life, wheel life, finish, size control, corrosion protection, and operator working conditions; increase machine {open_quotes}up-time{close_quotes}; and reduced machine tool maintenance.

Grabner, T.A. [ICF Kaiser Hanford Company, Richland, WA (United States)

1996-12-31

223

Structure and percolation of one-patch spherocylinders.  

PubMed

When the volume fraction exceeds the threshold, the colloidal particles would form a spanning cluster to realize percolation, which is affected by the shape of the particles, interaction between particles, etc. In this paper, we use the Monte Carlo method to study the structure and percolation of a system of one-patch spherocylinders which have been fabricated recently [Chaudhary et al., J. Am. Chem. Soc., 2012, 134, 12901]. With strong adsorption, one-patch spherocylinders self-assemble into multipods which further make contact with each other to form a percolation network at a high volume fraction, while the percolation network is inhibited by the local structures in a system of one-patch spheres. The main multipods are dipods when the patch angle equals ?/3, while they are tetrapods and pentapods when the patch angle equals 2?/3. With enhancing the adsorption, the bigger the patch angle, the more the percolation threshold drops. The orientational order parameter, the distribution of the relative orientation between the nearest neighbors and the probabilities of a spherocylinder owning n adsorbing neighbors have been calculated to analyze the formation and transition of the structures. PMID:25575168

Zhang, Cheng-Yu; Jian, Xing-Liang; Lu, Wei

2015-02-01

224

Gaussian model of explosive percolation in three and higher dimensions  

NASA Astrophysics Data System (ADS)

The Gaussian model of discontinuous percolation, recently introduced by Ara鷍o and Herrmann [Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.105.035701 105, 035701 (2010)], is numerically investigated in three dimensions, disclosing a discontinuous transition. For the simple cubic lattice, in the thermodynamic limit we report a finite jump of the order parameter J=0.4150.005. The largest cluster at the threshold is compact, but its external perimeter is fractal with fractal dimension dA=2.50.2. The study is extended to hypercubic lattices up to six dimensions and to the mean-field limit (infinite dimension). We find that, in all considered dimensions, the percolation transition is discontinuous. The value of the jump in the order parameter, the maximum of the second moment, and the percolation threshold are analyzed, revealing interesting features of the transition and corroborating its discontinuous nature in all considered dimensions. We also show that the fractal dimension of the external perimeter, for any dimension, is consistent with the one from bridge percolation and establish a lower bound for the percolation threshold of discontinuous models with a finite number of clusters at the threshold.

Schrenk, K. J.; Ara鷍o, N. A. M.; Herrmann, H. J.

2011-10-01

225

Memory decay and loss of criticality in quorum percolation  

NASA Astrophysics Data System (ADS)

In this paper, we present the effects of memory decay on a bootstrap percolation model applied to random directed graphs (quorum percolation). The addition of decay was motivated by its natural occurrence in physical systems previously described by percolation theory, such as cultured neuronal networks, where decay originates from ionic leakage through the membrane of neurons and/or synaptic depression. Surprisingly, this feature alone appears to change the critical behavior of the percolation transition, where discontinuities are replaced by steep but finite slopes. Using different numerical approaches, we show evidence for this qualitative change even for very small decay values. In experiments where the steepest slopes can not be resolved and still appear as discontinuities, decay produces nonetheless a quantitative difference on the location of the apparent critical point. We discuss how this shift impacts network connectivity previously estimated without considering decay. In addition to this particular example, we believe that other percolation models are worth reinvestigating, taking into account similar sorts of memory decay.

Renault, Renaud; Monceau, Pascal; Bottani, Samuel

2013-12-01

226

Viscosity and thermal conductivity of stable graphite suspensions near percolation.  

PubMed

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 P閏let number based on the rotary diffusivity of the graphite particles). PMID:25469709

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

2015-01-14

227

Connecting Core Percolation and Controllability of Complex Networks  

PubMed Central

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

Jia, Tao; P髎fai, M醨ton

2014-01-01

228

Fast and accurate database searches with MS-GF+Percolator  

SciTech Connect

To identify peptides and proteins from the large number of fragmentation spectra in mass spectrometrybased proteomics, researches commonly employ so called database search engines. Additionally, postprocessors like Percolator have been used on the results from such search engines, to assess confidence, infer peptides and generally increase the number of identifications. A recent search engine, MS-GF+, has previously been showed to out-perform these classical search engines in terms of the number of identified spectra. However, MS-GF+ generates only limited statistical estimates of the results, hence hampering 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 false discovery rate estimates, such as q values and posterior error probabilities, as well as p values, for peptide-spectrum matches, peptides and proteins, functions useful for the whole proteomics community.

Granholm, Viktor; Kim, Sangtae; Navarro, Jose' C.; Sjolund, Erik; Smith, Richard D.; Kall, Lukas

2014-02-28

229

Percolation crossing probabilities in hexagons: a numerical study  

NASA Astrophysics Data System (ADS)

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.

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

2015-01-01

230

Scaling behavior of explosive percolation on the square lattice  

NASA Astrophysics Data System (ADS)

Clusters generated by the product-rule growth model of Achlioptas, D扴ouza, and Spencer on a two-dimensional square lattice are shown to obey qualitatively different scaling behavior than standard (random growth) percolation. The threshold with unrestricted bond placement (allowing loops) is found precisely using several different criteria based on both moments and wrapping probabilities, yielding pc=0.5265650.000005 , consistent with the recent result of Radicchi and Fortunato. The correlation-length exponent ? is found to be close to 1. The qualitative difference from regular percolation is shown dramatically in the behavior of the percolation probability P? (size of largest cluster), of the susceptibility, and of the second moment of finite clusters, where discontinuities appear at the threshold. The critical cluster-size distribution does not follow a consistent power law for the range of system sizes we study (L?8192) but may approach a power law with ?>2 for larger L .

Ziff, Robert M.

2010-11-01

231

Absorbing-state phase transitions on percolating lattices.  

PubMed

We study nonequilibrium phase transitions of reaction-diffusion systems defined on randomly diluted lattices, focusing on the transition across the lattice percolation threshold. To develop a theory for this transition, we combine classical percolation theory with the properties of the supercritical nonequilibrium system on a finite-size cluster. In the case of the contact process, the interplay between geometric criticality due to percolation and dynamical fluctuations of the nonequilibrium system leads to a different universality class. The critical point is characterized by ultraslow activated dynamical scaling and accompanied by strong Griffiths singularities. To confirm the universality of this exotic scaling scenario we also study the generalized contact process with several (symmetric) absorbing states and we support our theory by extensive Monte Carlo simulations. PMID:19518178

Lee, Man Young; Vojta, Thomas

2009-04-01

232

Polymer Percolation Threshold in Multi-Component HPMC Matrices Tablets  

PubMed Central

Introduction:The percolation theory studies the critical points or percolation thresholds of the system, where one component of the system undergoes a geometrical phase transition, starting to connect the whole system.The application of this theory to study the release rate of hydrophilic matrices allows to explain the changes in release kinetics of swellable matrix type system and results in a clear improvement of the design of controlled release dosage forms. Methods: In this study, the percolation theory has been applied to multi-component hydroxypropylmethylcellulose (HPMC) hydrophilic matrices. Matrix tablets have been prepared using phenobarbital as drug, magnesium stearate as a lubricant employing different amount of lactose and HPMC K4M as a filler and matrix forming material, respectively. Ethylcelullose (EC) as a polymeric excipient was also examined. Dissolution studies were carried out using the paddle method.In order to estimate the percolation threshold, the behaviour of the kinetic parameters with respect to thevolumetric fraction of HPMC at time zero, was studied. Results: In both HPMC/lactose and HPMC/EC/lactose matrices, from the point of view of the percolation theory, the optimum concentration for HPMC, to obtain a hydrophilic matrix system for the controlled release of phenobarbital is higher than 18.1% (v/v) HPMC. Above 18.1% (v/v) HPMC, an infinite cluster of HPMC would be formed maintaining integrity of the system and controlling the drug release from the matrices. According to results, EC had no significant influence on the HPMC percolation threshold. Conclusion: This may be related to broad functionality of the swelling hydrophilic matrices. PMID:24312753

Maghsoodi, Maryam; Barghi, Leila

2011-01-01

233

Reverse Brazil Nut Problem: Competition between Percolation and Condensation  

NASA Astrophysics Data System (ADS)

In the Brazil nut problem (BNP), hard spheres with larger diameters rise to the top. There are various explanations (percolation, reorganization, convection), but a broad understanding or control of this effect is by no means achieved. A theory is presented for the crossover from BNP to the reverse Brazil nut problem based on a competition between the percolation effect and the condensation of hard spheres. The crossover condition is determined, and theoretical predictions are compared to molecular dynamics simulations in two and three dimensions.

Hong, Daniel C.; Quinn, Paul V.; Luding, Stefan

2001-04-01

234

The Reverse Brazil Nut Problem: Competition between Percolation and Condensation  

NASA Astrophysics Data System (ADS)

In the Brazil nut problem (BNP), hard spheres with larger diameters rise to the top. There are various explanations (percolation, reorganization, convection), but a broad understanding or control of this effect is by no means achieved. A theory is presented for the crossover from BNP to the reverse Brazil nut problem (RBNP) based on a competition between the percolation effect and the condensation of hard spheres. The crossover condition is determined, and theoretical predictions are compared to Molecular Dynamics simulations in two and three dimensions.

Quinn, Paul V.; Hong, Daniel C.; Luding, Stefan

2001-03-01

235

The Percolation Transition in Correlated and Frustrated Systems  

NASA Astrophysics Data System (ADS)

In the first part of this thesis, a variant of the classic percolation model is studied in which the elements experience a spatial correlation. The effect of correlations on the percolation quantities of interest is investigated, namely on the percolation threshold p_{c } and various static and dynamic exponents. Methods of analysis include solving the position space renormalization group equations exactly (for small cell sizes) and using various numerical methods to calculate the exponents. The methods used are Monte Carlo methods to obtain p _{c} and the correlation length exponent nu, the Ziff method to determine p_{c} accurately, Monte Carlo finite-size scaling to obtain the fractal dimensions of various cluster components, and the propagator method of Frank and Lobb to determine the conductivity exponent. It is observed that the universality class changes continuously with the strength of the correlation. However, it appears that strong universality still holds, in that the fractal dimension and related exponents do not change appreciably. Apart from the classic percolation model itself, the connectivity transition can be generalized to describe correctly the behaviour of many different systems, in particular the ferromagnetic q-state Potts models. In the second part of this thesis, the percolation transition is studied in both ferromagnetic and frustrated q-state Potts models, using series expansion methods. This is done by extending Enting's finite-lattice method that was used by Straley for calculating the high-temperature series for the partition function of the tree percolation model (q = 0) to the case of ferromagnetic and fully-frustrated q-state Potts models in the droplet formalism for general q. This enables the simultaneous calculation of both thermal (specific heat) and connectivity (mean number of clusters) quantities and consequently one can throw some light on the relation between the two kinds of transitions. For the ferromagnetic (FM) case, the existence of a percolation transition at the same temperature as the well-known FM Potts thermodynamic transition is verified. For the frustrated case, the percolation transition is found to occur at a temperature T _{p} that is in general higher than the corresponding thermodynamic transition temperature T_{c} = 0 of the model. (Abstract shortened by UMI.).

Prakash, Sona

236

Directed compact percolation near a damp wall with biased growth  

NASA Astrophysics Data System (ADS)

The model of directed compact percolation near a damp wall is generalized to allow for a bias in the growth of a cluster, either towards or away from the wall. The percolation probability for clusters beginning with seed width m, any distance from the wall, is derived exactly by solving the associated recurrences. It is found that the general biased case near a damp wall leads to a critical exponent ? = 1, in line with the dry biased case, which differs from the unbiased damp/dry exponent ? = 2.

Lonsdale, H.; Owczarek, A. L.

2012-11-01

237

Zero Waste Program 2011 Recycling Benefits  

E-print Network

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

Delgado, Mauricio

238

Percolation Approach to the Metal-Insulator Transition in SuperCritical Fluid Metals  

Microsoft Academic Search

The percolation theory is extended to a thermal equilibrium state of an interacting particle system. By a computer simulation method, percolation process in a square lattice gas model is studied in super-critical regions. Critical percolation density is found to be an increasing function of temperature. The critical index of percolation probability is almost independent of temperature and 0.145 0.027. The

Takashi Odagaki; Naofumi Ogita; Hirotsugu Matsuda

1975-01-01

239

RECYCLING RATE STUDY Prepared by  

E-print Network

storage batteries for automotive, marine, industrial, stationary, specialty, commercial and consumer uses A. Total Pounds of Lead Recycled from Batteries (continued) All starting, lighting and ignition (SLI

Laughlin, Robert B.

240

Waste recycling for energy conservation  

SciTech Connect

This book explains the philosophy and practice of resource and energy recovery; it provides pratical guidance for everyone involved in recycling and recovery procedures. Particular attention is directed towards mechanical sorting and to the classification of urban and industrial refuse; to refuse-derived fuels and their storage, handling, and incineration; and to the operational procedures which apply to recycling plants of all kinds. Carefully selected case histories describe important industrial recycling applications which function in Europe and in the USA; these highlight the benefits and the financial returns which can be achieved by thoughtful recycling.

Kut, D.; Hare, G.

1981-01-01

241

OTEC ammonia turbine design study  

Microsoft Academic Search

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

C. H. Kostors; S. P. Vincent

1979-01-01

242

Emulsified industrial oils recycling  

SciTech Connect

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.

Gabris, T.

1982-04-01

243

Reversible intercalation of ammonia molecules into a layered double hydroxide structure without exchanging nitrate counter-ions  

SciTech Connect

A zinc/aluminum LDH was precipitated with recycled ammonia from a chemical vapor deposition reaction. The LDH presented a crystalline phase with basal distance of 8.9 A, typical for nitrate-containing LDHs, and another phase with a basal distance of 13.9 A. Thermal treatment at 150 {sup o}C eliminated the phase with the bigger basal distance leaving only the anhydrous nitrate-intercalated LDH structure with 8.9 A. Intense N-H stretching modes in the FTIR spectra suggested that the expansion was due to intercalation of ammonia in the form of [NH{sub 4}(NH{sub 3}){sub n}]{sup +} species. When additional samples were precipitated with pure ammonia, the conventional LDH nitrate structure was obtained (8.9 A basal distance) at pH=7, as well as a pure crystalline phase with 13.9 A basal distance at pH=10 due to ammonia intercalation that can be removed by heating at 150 {sup o}C or by stirring in acetone, confirming a unusual sensu stricto intercalation process into a LDH without exchanging nitrate ions. - Graphical abstract: LDH-nitrate precipitated with ammonia expands the interlayer space if ammonia is bubbled up to pH 10. The basal distance decreased when the compound was heated at 150 {sup o}C or stirred in acetone. Nitrate ions are not exchanged.

Carbajal Arizaga, Gregorio Guadalupe, E-mail: gregoriocarbajal@yahoo.com.m [Universidad Nacional Autonoma de Mexico, Centro de Nanociencias y Nanotecnologia, Km. 107 Carretera Tijuana-Ensenada, Apdo. Postal 14, C.P. 22800. Ensenada, Baja California (Mexico); Wypych, Fernando [CEPESQ-Research Centre of Applied Chemistry, Department of Chemistry, Federal University of Parana, P.O. Box 19081, 81531-980 Curitiba, PR (Brazil); Castillon Barraza, Felipe; Contreras Lopez, Oscar Edel [Universidad Nacional Autonoma de Mexico, Centro de Nanociencias y Nanotecnologia, Km. 107 Carretera Tijuana-Ensenada, Apdo. Postal 14, C.P. 22800. Ensenada, Baja California (Mexico)

2010-10-15

244

Fiber-Optic Ammonia Sensors  

NASA Technical Reports Server (NTRS)

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

Carter, Michael T.

2003-01-01

245

Recycled rubber roads  

SciTech Connect

The paper describes several innovative approaches for recycling old tires in the construction of roads. In one, 18 inches of shredded tire chips (2 X 2 inches) were used on top of 6-8 inches of small stone to construct a road across a sanitary landfill. No compacting or linders were needed. In another application, sidewall mats linked together with steel strapping were used as a sub-base for a road across a swampy area. A third application uses 1/2 inch bits of groundup rubber tires as a replacement for aggregate in an asphalt road base.

Not Available

1989-02-01

246

Recycler barrier RF buckets  

SciTech Connect

The Recycler Ring at Fermilab uses a barrier rf systems for all of its rf manipulations. In this paper, I will give an overview of historical perspective on barrier rf system, the longitudinal beam dynamics issues, aspects of rf linearization to produce long flat bunches and methods used for emittance measurements of the beam in the RR barrier rf buckets. Current rf manipulation schemes used for antiproton beam stacking and longitudinal momentum mining of the RR beam for the Tevatron collider operation are explained along with their importance in spectacular success of the Tevatron luminosity performance.

Bhat, C.M.; /Fermilab

2011-03-01

247

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

E-print Network

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

Krokhmal, Paul

248

On directed compact percolation near a damp wall H Lonsdale1  

E-print Network

On directed compact percolation near a damp wall H Lonsdale1 , R Brak1 , J W Essam2 , A L Owczarek1 The percolation probability for directed, compact percolation near a damp wall, which interpolates between wall, rather than the value previously found in the wet wall and bulk cases. The solution is found via

Rechnitzer, Andrew

249

Process for the recovery of hydrogen from ammonia purge gases  

Microsoft Academic Search

Ammonia synthesis processes are disclosed which provide enhanced conversion of hydrogen values to ammonia. In the processes, a purge stream from an ammonia synthesis loop is treated to reduce its ammonia content to less than about 0.5 volume percent. The purge stream is then contacted at a pressure of at least substantially the superatmospheric synthesis pressure of the ammonia synthesis

1979-01-01

250

Process for hydrogen recovery from ammonia purge gases  

Microsoft Academic Search

Ammonia synthesis processes are disclosed which provide enhanced conversion of hydrogen values to ammonia. In the processes, a purge stream from an ammonia synthesis loop, which purge stream contains ammonia, is contacted at a superatmospheric pressure with the feed side of a separation membrane which exhibits selective permeation of each of hydrogen and ammonia as compared to the permeation of

H. R. Null; E. Perry

1979-01-01

251

CFC recycling system  

SciTech Connect

This patent describes a method for recycling freon. It comprises attaching a freon removal valve to a freon supply located in an appliance such as an air conditioner, refrigerator, freezer or the like, positioning a substantially empty freon collecting vessel in gas flow relationship to the valve by providing the freon removal valve with a puncture needle extending upwardly and adapted to puncture a freon supply tubing in the appliance, below the puncture needle is positioned a spring means, and below the spring means is positioned a piercing means adapted to pierce a closure in the collecting vessel to thereby establish a gas passage means extending from the supply tube, through the needle, through the piercing means to the collecting vessel, collecting the freon thereby in the collecting vessel, providing a substantially gas-free sealing means on the collecting vessel to insure substantial total containment of the freon within the collecting vessel, and delivering the collecting vessel to a collection center for reuse and recycling of the freon.

Furmanek, D.J.

1991-06-25

252

RECYCLING: SUPPLY, ECONOMICS, ENVIRONMENT, AND TECHNOLOGY  

E-print Network

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

Abubakr, Said

253

Polyaniline-based optical ammonia detector  

DOEpatents

Electronic absorption spectroscopy of a polyaniline film deposited on a polyethylene surface by chemical oxidation of aniline monomer at room temperature was used to quantitatively detect ammonia gas. The present optical ammonia gas detector was found to have a response time of less than 15 s, a regeneration time of less than 2 min. at room temperature, and a detection limit of 1 ppm (v/v) for ammonia, with a linear dynamic range from 180 ppm to 18,000 ppm.

Duan, Yixiang (Los Alamos, NM); Jin, Zhe (Los Alamos, NM); Su, Yongxuan (Los Alamos, NM)

2002-01-01

254

Adsorption of ammonia on multilayer iron phthalocyanine  

SciTech Connect

The adsorption of ammonia on multilayers of well-ordered, flat-lying iron phthalocyanine (FePc) molecules on a Au(111) support was investigated by x-ray photoelectron spectroscopy. We find that the electron-donating ammonia molecules coordinate to the metal centers of iron phthlalocyanine. The coordination of ammonia induces changes of the electronic structure of the iron phthalocyanine layer, which, in particular, lead to a modification of the FePc valence electron spin.

Isvoranu, Cristina; Knudsen, Jan; Ataman, Evren; Andersen, Jesper N.; Schnadt, Joachim [Division of Synchrotron Radiation Research, Department of Physics, Lund University, Box 118, 221 00 Lund (Sweden); Schulte, Karina [MAX-lab, Lund University, Box 118, 221 00 Lund (Sweden); Wang Bin; Bocquet, Marie-Laure [Laboratoire de chimie, Ecole normale superieure de Lyon, 46, Allee d'Italie, 69364 Lyon Cedex 07 (France)

2011-03-21

255

Ammonia Assimilation by Rhizobium Cultures and Bacteroids  

Microsoft Academic Search

SUMMARY The enzymes involved in the assimilation of ammonia by free-living cultures of Rhizobium spp. are glutamine synthetase (EC. 6.3. I. 2), glutamate synthase (L- glutamine : a-oxoglutarate amino transferase) and glutamate dehydrogenase (EC I.4. I.4). Under conditions of ammonia or nitrate limitation in a chemostat the assimilation of ammonia by cultures of R. leguminosarum, R. trifolii and R. japonicum

C. M. BROWN; M. J. DILWORTH

1975-01-01

256

Inhibitor performance in process water containing ammonia  

SciTech Connect

Ammonia is a prevalent contaminant and issue in water reuse. Since ammonia exhibits decreasing dissociation with increasing pH, operation of cooling systems at high pH is effective in improving corrosion control, biocide demand and overall system performance. Polyamino polyether methylene phosphate based programs for high pH conditions provided scale and corrosion control at very high levels of ammonia contamination at a northern steel mill.

Sherwood, N.S. [Calgon Corp., Pittsburgh, PA (United States)

1998-12-31

257

Planar percolation with a glimpse of SchrammLoewner Evolution  

E-print Network

Planar percolation with a glimpse of Schramm颅Loewner Evolution Vincent Beffara Hugo Duminil-dimensional statistical physics. One of the most striking achievements is the proof of the Cardy-Smirnov formula: this theorem, together with the introduction of Schramm- Loewner Evolution and techniques developed over

Paris-Sud XI, Universit茅 de

258

Dynamics of driven interfaces near isotropic percolation transition  

NASA Astrophysics Data System (ADS)

We consider the dynamics and kinetic roughening of interfaces embedded in uniformly random media near percolation treshold. In particular, we study simple discrete ``forest fire'' lattice models through Monte Carlo simulations in two and three spatial dimensions. An interface generated in the models is found to display complex behavior. Away from the percolation transition, the interface is self-affine with asymptotic dynamics consistent with the Kardar-Parisi-Zhang universality class. However, in the vicinity of the percolation transition, there is a different behavior at earlier times. By scaling arguments we show that the global scaling exponents associated with the kinetic roughening of the interface can be obtained from the properties of the underlying percolation cluster. Our numerical results are in good agreement with theory. However, we demonstrate that at the depinning transition, the interface as defined in the models is no longer self-affine. Finally, we compare these results with those obtained from a more realistic reaction-diffusion model of slow combustion.

Kuittu, M.-P.; Haataja, M.; Provatas, N.; Ala-Nissila, T.

1998-08-01

259

Level statistics for quantum k-core percolation  

NASA Astrophysics Data System (ADS)

Quantum k-core percolation is the study of quantum transport on k-core percolation clusters where each occupied bond must have at least k occupied neighboring bonds. As the bond occupation probability p is increased from zero to unity, the system undergoes a transition from an insulating phase to a metallic phase. When the length scale for the disorder ld is much greater than the coherence length lc, earlier analytical calculations of quantum conduction on the Bethe lattice demonstrated that for k=3 the metal-insulator transition (MIT) is discontinuous, suggesting a new type of disorder-driven quantum MITs. Here, we numerically compute the level spacing distribution as a function of bond occupation probability p and system size on a Bethe-like lattice. The level spacing analysis suggests that for k=0, pq, the quantum percolation critical probability, is greater than pc, the geometrical percolation critical probability, and the transition is continuous. In contrast, for k=3, pq=pc, and the transition is discontinuous such that these numerical findings are consistent with our previous work to reiterate a new random first-order phase transition and therefore a new universality class of disorder-driven quantum MITs.

Cao, L.; Schwarz, J. M.

2012-08-01

260

Fragility of liquids using percolation-based transport theories  

Microsoft Academic Search

Transport in super-cooled liquids becomes increasingly heterogeneous with reduction in temperature. This transport is assumed to occur by thermally activated hopping over barriers. At a temperature defined here to be Tc, transport becomes percolative rather than diffusive, and, especially for mechanical relaxation, larger energy barriers must be surmounted in order to establish steady-state response. Use of the same distribution of

A. G Hunt

2000-01-01

261

Parabolic Harnack Inequality and Local Limit Theorem for Percolation Clusters  

Microsoft Academic Search

We consider the random walk on supercritical percolation clusters in the d-dimensional Euclidean lattice. Previous papers have obtained Gaussian heat kernel bounds, and a.s. invariance principles for this process. We show how this information leads to a parabolic Harnack inequality, a local limit theorem and estimates on the Green's function.

Martin Barlow; Ben Hambly

2008-01-01

262

PERCOLATION AND SUPERCONDUCTIVITY IN ION-IMPLANTED ALUMINIUM FILMS (*)  

E-print Network

L-435 PERCOLATION AND SUPERCONDUCTIVITY IN ION-IMPLANTED ALUMINIUM FILMS (*) F. MEUNIER and P of Si and Ge in Al thin films at 8 K produces alloys exhibiting enhanced superconducting transition in the superconducting transition temperature Tc of several such alloys [2], [5], [6] : Josephson tunnelling

Boyer, Edmond

263

Polymer Collapse, Protein Folding, and the Percolation Threshold  

E-print Network

Polymer Collapse, Protein Folding, and the Percolation Threshold HAGAI MEIROVITCH University (Macromolecules 1989, 22, 3986颅3997) 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

Meirovitch, Hagai

264

A rapid Percoll gradient procedure for preparation of synaptosomes  

Microsoft Academic Search

Homogenization of fresh brain tissue in isotonic medium shears plasma membranes causing nerve terminals to become separated from their axons and postsynaptic connections. The nerve terminal membranes then reseal to form synaptosomes. The discontinuous Percoll gradient procedure described here is designed to isolate synaptosomes from brain homogenates in the minimum time to allow functional experiments to be performed. Synaptosomes are

Paula E Jarvie; Phillip J Robinson; Peter R Dunkley

2008-01-01

265

Dynamical Instability in Boolean Networks as a Percolation Problem  

NASA Astrophysics Data System (ADS)

Boolean networks, widely used to model gene regulation, exhibit a phase transition between regimes in which small perturbations either die out or grow exponentially. We show and numerically verify that this phase transition in the dynamics can be mapped onto a static percolation problem which predicts the long-time average Hamming distance between perturbed and unperturbed orbits.

Squires, Shane; Ott, Edward; Girvan, Michelle

2012-08-01

266

Fabrication, Microstructure, Magnetic, and Recording Properties of Percolated Perpendicular Media  

Microsoft Academic Search

In this paper, a new type of perpendicular magnetic media which we have termed percolated perpendicular media is discussed. We present the method we used to fabricate the media as well as an energetic rationale for the driving force to produce the desired microstructure. The microstructures of samples with various amounts of oxide material are presented and the optimum one

David E. Laughlin; Yingguo Peng; Yue-Ling Qin; Mark Lin; Jian-Gang Zhu

2007-01-01

267

Percolation in Transparent and Conducting Carbon Nanotube Networks  

E-print Network

Percolation in Transparent and Conducting Carbon Nanotube Networks L. Hu, D. S. Hecht, G. Gr眉ner: single tube devices have mobilities as high as 100,000 cm2 /Vs 1 , current carrying capacities of 109 A to reproduce single tube devices consistently due to the variations in chirality and geometry from tube to tube

Gruner, George

268

Enhanced electromechanical properties in all-polymer percolative composites  

E-print Network

-organic composites,7 where electrostrictive strain as high as 2% has been obtained. However, the exchange and the electrostrictive strain as high as 2.5% have been obtained at a modest applied electric field about 10 MVEnhanced electromechanical properties in all-polymer percolative composites Jiang Yu Lia

Li, Jiangyu

269

Continuity of a percolation function on the hierarchical group  

E-print Network

for Cyber Security, University of Texas at San Antonio San Antonio, Texas 78249, USA 2 SUTD. Some questions of percolation in other non颅Euclidean infinite systems is formulated in [4]. The study in probability theory and statistical physics [1, 5, 6, 7, 16, 17, 19]. On the other hand, hierarchical

270

Diversity of ammonia monooxygenase operon in autotrophic ammonia-oxidizing bacteria  

Microsoft Academic Search

Autotrophic ammonia-oxidizing bacteria use the essential enzyme ammonia monooxygenase (AMO) to transform ammonia to hydroxylamine. The amo operon consists of at least three genes, amoC, amoA, and amoB; amoA encodes the subunit containing the putative enzyme active site. The use of the amo genes as functional markers for ammonia-oxidizing bacteria in environmental applications requires knowledge of the diversity of the

Jeanette M. Norton; Javier J. Alzerreca; Yuichi Suwa; Martin G. Klotz

2002-01-01

271

Review Article: Recycling of Polystyrene  

Microsoft Academic Search

Recycling of polystyrene can be done by mechanical, chemical, and thermal methods. High impact polystyrene is a promising material for mechanical recycling since its properties are not extremely affected even after multiple processing of upto nine cycles. Production of liquid products and gaseous products are highly dependent on the reaction condition. The catalysts used are highly selective for the production

T. Maharana; Y. S. Negi; B. Mohanty

2007-01-01

272

Framework for Building Design Recyclability  

E-print Network

.2 Sustainable Construction .................................................................................... 4 1.2.1 Interpreting Sustainable Construction.......................................................... 5 1.2.2 Reduce, Reuse, and Recycling... for sustainable construction. They were: 1. Reduce resource consumption 2. Reuse resources 3. Use recyclable resources 4. Protect nature 5. Eliminate toxics 6. Apply lifecycle costing 7. Focus on quality Construction industry has tremendous impact...

Zhang, Fan

2008-01-01

273

Bacterial cell-wall recycling  

PubMed Central

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梐nd quite possibly all梑acteria, 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杢argeting 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

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

2012-01-01

274

Information Sources on Rural Recycling.  

ERIC Educational Resources Information Center

Provides resources for rural recycling operations with the principle aim of assisting rural government officials, planners, residents, and educators to encourage recycling as an integral part of an individual's or community's solid waste management plan. Sources range from bibliographies, directories, and government documents to case studies. (49

Notess, Greg; Kuske, Jodee

1992-01-01

275

Training Governments to Buy Recycled.  

ERIC Educational Resources Information Center

Describes a program developed by the Northeast Maryland Waste Disposal Authority to teach government buyers how to buy recycled materials. The program consists of a hands-on training seminar and a manual that offers step-by-step instructions for setting up a buy-recycled purchasing program. (LZ)

Keller, Richard

1995-01-01

276

The Dynamic Earth: Recycling Naturally!  

ERIC Educational Resources Information Center

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

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

2013-01-01

277

Bacterial cell-wall recycling.  

PubMed

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. Although 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

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

2013-01-01

278

Recycling Solid Waste in Chattanooga  

ERIC Educational Resources Information Center

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)

Vredeveld, Ruth; Martin, Robin

1973-01-01

279

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.

280

Network representation of pore scale imagery for percolation models  

NASA Astrophysics Data System (ADS)

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.

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

2012-12-01

281

Ammonia drives dendritic cells into dysfunction.  

PubMed

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

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

282

Endosomal recycling regulation during cytokinesis  

PubMed Central

Successful cytokinesis is critical for cell proliferation and development. In animal cells, cytokinesis relies on temporally and spatially regulated membrane addition to the cleavage site. An important source for the new membrane is recycling endosomes. Yet how these endocytic vesicles are transported and regulated remains unclear. Several potential factors have been recently identified that regulate the trafficking of recycling endosomes during cytokinesis. Dynein and dynactin are required for the retrograde transport of recycling endosomes, while Kinesin-1 is responsible for endosome delivery to the furrow and midbody. Other regulators of recycling endosome trafficking have been identified, including RACK1, JIP3/4 and ECT2, which target recycling endosomes during the cell cycle. Here, we provide insights into the mechanisms controlling endosomal trafficking during cytokinesis. PMID:19907714

Ai, Erkang

2009-01-01

283

Process for separating ammonia and acid gases from waste waters containing fixed ammonia salts  

Microsoft Academic Search

A water purification process is described for the removal of ammonia and optionally one or more acid gases from waste waters such as coke-plant or coal conversion waste waters. The process involves adding lime to these waste waters in amounts sufficient to react with fixed ammonia salts present in the waste water and to enable substantial amounts of the ammonia

W. J. Didycz; D. Glassman; E. E. Maier; G. T. Saniga

1978-01-01

284

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

SciTech Connect

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.

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

2013-01-01

285

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

NASA Astrophysics Data System (ADS)

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.

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

2014-08-01

286

21 CFR 862.1065 - Ammonia test system.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Ammonia test system. 862.1065 Section 862...Clinical Chemistry Test Systems 862.1065 Ammonia test system. (a) Identification. An ammonia test system is a device intended to...

2013-04-01

287

21 CFR 862.1065 - Ammonia test system.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Ammonia test system. 862.1065 Section 862...Clinical Chemistry Test Systems 862.1065 Ammonia test system. (a) Identification. An ammonia test system is a device intended to...

2012-04-01

288

21 CFR 862.1065 - Ammonia test system.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Ammonia test system. 862.1065 Section 862...Clinical Chemistry Test Systems 862.1065 Ammonia test system. (a) Identification. An ammonia test system is a device intended to...

2010-04-01

289

21 CFR 862.1065 - Ammonia test system.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Ammonia test system. 862.1065 Section 862...Clinical Chemistry Test Systems 862.1065 Ammonia test system. (a) Identification. An ammonia test system is a device intended to...

2011-04-01

290

Recycle of waste paper  

SciTech Connect

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.

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

1988-01-01

291

Plastics recycling: challenges and opportunities  

PubMed Central

Plastics are inexpensive, lightweight and durable materials, which can readily be moulded into a variety of products that find use in a wide range of applications. As a consequence, the production of plastics has increased markedly over the last 60 years. However, current levels of their usage and disposal generate several environmental problems. Around 4 per cent of world oil and gas production, a non-renewable resource, is used as feedstock for plastics and a further 34% is expended to provide energy for their manufacture. A major portion of plastic produced each year is used to make disposable items of packaging or other short-lived products that are discarded within a year of manufacture. These two observations alone indicate that our current use of plastics is not sustainable. In addition, because of the durability of the polymers involved, substantial quantities of discarded end-of-life plastics are accumulating as debris in landfills and in natural habitats worldwide. Recycling is one of the most important actions currently available to reduce these impacts and represents one of the most dynamic areas in the plastics industry today. Recycling provides opportunities to reduce oil usage, carbon dioxide emissions and the quantities of waste requiring disposal. Here, we briefly set recycling into context against other waste-reduction strategies, namely reduction in material use through downgauging or product reuse, the use of alternative biodegradable materials and energy recovery as fuel. While plastics have been recycled since the 1970s, the quantities that are recycled vary geographically, according to plastic type and application. Recycling of packaging materials has seen rapid expansion over the last decades in a number of countries. Advances in technologies and systems for the collection, sorting and reprocessing of recyclable plastics are creating new opportunities for recycling, and with the combined actions of the public, industry and governments it may be possible to divert the majority of plastic waste from landfills to recycling over the next decades. PMID:19528059

Hopewell, Jefferson; Dvorak, Robert; Kosior, Edward

2009-01-01

292

Method for releasing hydrogen from ammonia borane  

SciTech Connect

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.

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

2013-02-19

293

Depletion of Ammonia Gas onto Jovian Ices  

NASA Astrophysics Data System (ADS)

The microwave spectrum of Jupiter is consistent with supersolar ammonia deeper than 6 bar, and subsolar ammonia at pressures less than 2 bar. Because the Galileo Probe Mass Spectrometer measured a deep NH3/H2 mixing ratio of 6.4x10-4---or five times the protosolar ratio---the microwave data show that there must be a global-scale depletion mechanism for ammonia gas, operating between the 2 and 6 bar levels. Candidate depletion mechanisms include dynamics, condensation of species with higher nitrogen fractions than NH4SH (including clathrates), and adsorption of ammonia onto NH4SH or water ices. -- We have begun laboratory experiments designed to measure the uptake of ammonia by H2O and H2O-NH4SH ice mixtures. We also plan model calculations to apply the experimental results to Jupiter's atmosphere and quantify the effect of ammonia uptake by ices. The laboratory study uses a Knudsen cell apparatus in a temperature regime (130-250 K) appropriate to the troposphere of Jupiter around the 2-4 bar pressure level, where the microwave data indicate depletion of ammonia gas. We will discuss the key parameters and processes that influence the ammonia uptake and their relevance to Jupiter's atmosphere. This work is supported by the NASA Planetary Atmospheres Program.

Wong, Michael H.; Kasper, T.; Marschall, J.; de Pater, I.; Romani, P. N.; Kalogerakis, K. S.

2010-10-01

294

Evaluation of ammonia emissions from broiler litter  

Technology Transfer Automated Retrieval System (TEKTRAN)

Ammonia emissions from poultry litter results in air pollution and can cause high levels of ammonia in poultry houses, which negatively impacts bird performance. The objectives of this study were to: (1) conduct a nitrogen (N) mass balance in broiler houses by measuring the N inputs (bedding, chick...

295

Ammonia Solubility in High Concentration Salt Solutions  

SciTech Connect

Solubility data for ammonia in water and various dilute solutions are abundant in the literature. However, there is a noticeable lack of ammonia solubility data for high salt, basic solutions of various mixtures of salts including those found in many of the Hanford Washington underground waste tanks. As a result, models based on solubility data for dilute salt solutions have been used to extrapolate to high salt solutions. These significant extrapolations need to be checked against actual laboratory data. Some indirect vapor measurements have been made. A more direct approach is to determine the ratio of solubility of ammonia in water to its solubility in high salt solutions. In various experiments, pairs of solutions, one of which is water and the other a high salt solution, are allowed to come to equilibrium with a common ammonia vapor pressure. The ratio of concentrations of ammonia in the two solutions is equal to the ratio of the respective ammonia solubilities (Henry's Law constants) at a given temperature. This information can then be used to refine the models that predict vapor space compositions of ammonia. Ammonia at Hanford is of concern because of its toxicity in the environment and its contribution to the flammability of vapor space gas mixtures in waste tanks.

HEDENGREN, D.C.

2000-02-01

296

METHOD FOR PRODUCING DEUTERIUM WHEN SYNTHESIZING AMMONIA  

Microsoft Academic Search

Deuterium can be produced by means of hydrogen exchange reactions ; between the hydrogen molecules and ammonia in the presence of a catalyst or by ; means of distillation. The method described is for producing a base material for ; this process which is already enriched in deuterium. It comprises the steps of ; separating ammonia, nitrogen, and inert gases

G. Schaurer; A. Heinzel

1963-01-01

297

METHODOLOGY AND INSTRUMENTATION TO MEASURE GASEOUS AMMONIA  

EPA Science Inventory

Methodology for the time integrated collection and analysis of atmospheric ammonia was developed. Ammonia is primarily measured because it can react with SOx to produce ammonium sulfate. Since SOx is one of the principle air pollutants, it is important to determine its atmospheri...

298

Energetic analysis of ammonia synthesis unit  

Microsoft Academic Search

In order to identify possible reserves in the ammonia synthesis, an exergetic analysis was made of the stages of nitrogen-hydrogen compression, ammonia synthesis and separation at an operating plant. The analysis showed that the unit has a relatively low degree of thermodynamic completeness: the target exergetic efficiency of the stages studied is 0.26. The margins for improvement are not great.

G. A. Britina; I. L. Leites; S. A. Mikhailova; M. B. Aizenbud

1977-01-01

299

Regeneration of ammonia borane from polyborazylene  

DOEpatents

Method of producing ammonia borane, comprising providing a reagent comprising a dehydrogenated material in a suitable solvent; and combining the reagent with a reducing agent comprising hydrazine, a hydrazine derivative, or combinations thereof, in a reaction which produces a mixture comprising ammonia borane.

Sutton, Andrew; Gordon, John C; Ott, Kevin C; Burrell, Anthony K

2013-02-05

300

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

NASA Technical Reports Server (NTRS)

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.

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

2005-01-01

301

Incubating small recycling technology developers  

SciTech Connect

Most new Recycling Technologies are being commercialized by small, and sometimes very small companies. These organizations lack the facilities to undertake the work necessary to prove the effectiveness of their technology at the pilot to semi-commercial scale. ORTECH has used their extensive bench and pilot plant facilities, plus technical expertise to partner with a number of new recycling technology developers to help them successfully commercialize these technologies. The paper will describe technological developments undertaken by three such partnerships involving recycling of: CFCs, fiberglass and high value metals from waste streams.

Lakshmanan, V.I.; Laughlin, R.G.W. [ORTECH Corp., Mississauga, Ontario (Canada)

1997-12-31

302

Coal liquefaction with preasphaltene recycle  

DOEpatents

A coal liquefaction system is disclosed with a novel preasphaltene recycle from a supercritical extraction unit to the slurry mix tank wherein the recycle stream contains at least 90% preasphaltenes (benzene insoluble, pyridine soluble organics) with other residual materials such as unconverted coal and ash. This subject process results in the production of asphaltene materials which can be subjected to hydrotreating to acquire a substitute for No. 6 fuel oil. The preasphaltene-predominant recycle reduces the hydrogen consumption for a process where asphaltene material is being sought.

Weimer, Robert F. (Allentown, PA); Miller, Robert N. (Allentown, PA)

1986-01-01

303

The College Student's Guide to Recycling,  

E-print Network

The College Student's Guide to Recycling, Reduction, and Reuse UNIVERSITY AT ALBANY Phone Albany, NY 12222 Top 7 Recycling and Reuse TipsTop 7 Recycling and Reuse Tips University at Albany Office of Environmental Sustainability 1. Set up separate bins for recyclable materials such as plastics and papers. 2

Kidd, William S. F.

304

WasteTraining Booklet Waste & Recycling Impacts  

E-print Network

WasteTraining Booklet #12;Waste & Recycling Impacts Environment: The majority of our municipal jobs while recycling 10,000 tons of waste creates 36 jobs. Environment: Recycling conserves resources. It takes 95% less energy to make aluminum from recycled aluminum than from virgin materials, 60% less

Saldin, Dilano

305

You're a "What"? Recycling Coordinator  

ERIC Educational Resources Information Center

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,

Torpey, Elka Maria

2011-01-01

306

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

NASA Technical Reports Server (NTRS)

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.

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

2014-01-01

307

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

NASA Technical Reports Server (NTRS)

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.

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

2014-01-01

308

Regeneration of ammonia borane spent fuel  

SciTech Connect

A necessary target in realizing a hydrogen (H{sub 2}) economy, especially for the transportation sector, is its storage for controlled delivery, presumably to an energy producing fuel cell. In this vein, the U.S. Department of Energy's Centers of Excellence (CoE) in Hydrogen Storage have pursued different methodologies, including metal hydrides, chemical hydrides, and sorbents, for the expressed purpose of supplanting gasoline's current > 300 mile driving range. Chemical H{sub 2} storage has been dominated by one appealing material, ammonia borane (H{sub 3}N-BH{sub 3}, AB), due to its high gravimetric capacity of H{sub 2} (19.6 wt %) and low molecular weight (30.7 g mol{sup -1}). In addition, AB has both hydridic and protic moieties, yielding a material from which H{sub 2} can be readily released in contrast to the loss of H{sub 2} from C{sub 2}H{sub 6} which is substantially endothermic. As such, a number of publications have described H{sub 2} release from amine boranes, yielding various rates depending on the method applied. The viability of any chemical H{sub 2} storage system is critically dependent on efficient recyclability, but reports on the latter subject are sparse, invoke the use of high energy reducing agents, and suffer from low yields. Our group is currently engaged in trying to find and fully demonstrate an energy efficient regeneration process for the spent fuel from H{sub 2} depleted AB with a minimum number of steps. Although spent fuel composition depends on the dehydrogenation method, we have focused our efforts on the spent fuel resulting from metal-based catalysis, which has thus far shown the most promise. Metal-based catalysts have produced the fastest rates for a single equivalent of H{sub 2} released from AB and up to 2.5 equiv. of H{sub 2} can be produced within 2 hours. While ongoing work is being carried out to tailor the composition of spent AB fuel, a method has been developed for regenerating the predominant product, polyborazylene (PB) which can be obtained readily from the decomposition of borazine or from nickel carbene catalyst dehydrogenation. In this cycle, the PB is digested with benzenedithiol to yield two products which can both be converted to AB using Bu{sub 3}SnH and BU{sub 2}SnH{sub 2} as reductants. However, in a real world situation the process becomes more complicated for several reasons. Bu{sub 2}SnH{sub 2} is thermally unstable and therefore not viable in a process scale operation. This has led to the development of Bu{sub 3}SnH as the sole reductant although this requires an additional amine exchange step in order to facilitate the reduction to an amine-borane which can then be converted to AB. The tin by-products also need to be recycled in order to maximize the overall energy efficiency and therefore minimize the overall cost of the process. In addition, on an industrial scale, the mass of the tin reductant generates significant cost due to the manipulation of the relatively large quantities involved so reducing the mass at this stage would be of vast significance. We will discuss further developments made to the tin recycle component of the cycle (including methods to minimize tin usage) and investigate new methods of reduction of the digested products, primarily focusing on lighter reductants, including lighter analogs of Bu{sub 2}SnH{sub 2} and Bu{sub 3}SnH. These advances will have a significant impact on the cost of production and therefore the viability of AB as a fuel. Minimization of tin reagents and their recycle will contribute to reduction of the overall cost of AB regeneration and all stages of AB regeneration have been demonstrated.

Sutton, Andrew David [Los Alamos National Laboratory; Davis, Benjamin L [Los Alamos National Laboratory; Gordon, John C [Los Alamos National Laboratory

2009-01-01

309

Rab15 Effector Protein: A Novel Protein for Receptor Recycling from the Endocytic Recycling Compartment  

Microsoft Academic Search

Sorting endosomes and the endocytic recycling compartment are critical intracellular stores for the rapid recycling of internalized membrane receptors to the cell surface in multiple cell types. However, the molecular mechanisms distin- guishing fast receptor recycling from sorting endosomes and slow receptor recycling from the endocytic recycling compartment remain poorly understood. We previously reported that Rab15 differentially regulates transferrin receptor

David J. Strick; Lisa A. Elferink

2005-01-01

310

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

E-print Network

TTUAB PLASTIC RECYCLING PROTOCOL 颅 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

Rock, Chris

311

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

E-print Network

Recycling will take only a few minutes but will have a profound impact on the environment. MIXED PAPER WhiteWelcome 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

Almor, Amit

312

Percolation model of polydisperse composite solid propellant combustion  

SciTech Connect

The composition dependence of the burn rate of polydisperse composite solid propellants is predicted by analyzing the least-time path of the burn front through the propellant. The predicted burn rate is the average burn rate along the least-time path divided by the tortuosity, or arc length per streamwise interval, of the least-time path. The tortuosity analysis is based on percolation theory. Aspects of percolation theory which are pertinent to the analysis are introduced in a self-contained Appendix. The model, which contains four adjustable parameters, is validated by comparison to measured burn rates for a suite of polydisperse ammonium perchlorate composites. The data correlations are found to be significantly better than for a three-parameter version of the model which omits tortuosity considerations.

Kerstein, A.R.

1987-07-01

313

Fractal structure of equipotential curves on a continuum percolation model  

NASA Astrophysics Data System (ADS)

We numerically investigate the electric potential distribution over a two-dimensional continuum percolation model between the electrodes. The model consists of overlapped conductive particles on the background with an infinitesimal conductivity. Using the finite difference method, we solve the generalized Laplace equation and show that in the potential distribution, there appear quasi-equipotential clusters which approximately and locally have the same values as steps and stairs. Since the quasi-equipotential clusters have the fractal structure, we compute the fractal dimension of equipotential curves and its dependence on the volume fraction over [0,1]. The fractal dimension in [1.00, 1.246] has a peak at the percolation threshold pc.

Matsutani, Shigeki; Shimosako, Yoshiyuki; Wang, Yunhong

2012-12-01

314

Quantum percolation in cuprate high-temperature superconductors  

PubMed Central

Although it is now generally acknowledged that electron杙honon interactions cause cuprate superconductivity with Tc values ?100 K, the complexities of atomic arrangements in these marginally stable multilayer materials have frustrated both experimental analysis and theoretical modeling of the remarkably rich data obtained both by angle-resolved photoemission (ARPES) and high-resolution, large-area scanning tunneling microscopy (STM). Here, we analyze the theoretical background in terms of our original (1989) model of dopant-assisted quantum percolation (DAQP), as developed further in some two dozen articles, and apply these ideas to recent STM data. We conclude that despite all of the many difficulties, with improved data analysis it may yet be possible to identify quantum percolative paths. PMID:18626024

Phillips, J. C.

2008-01-01

315

Directed percolation in two dimensions: An exact solution  

E-print Network

We consider a directed percolation process on an ${\\cal M}$ x ${\\cal N}$ rectangular lattice whose vertical edges are directed upward with an occupation probability y and horizontal edges directed toward the right with occupation probabilities x and 1 in alternate rows. We deduce a closed-form expression for the percolation probability P(x,y), the probability that one or more directed paths connect the lower-left and upper-right corner sites of the lattice. It is shown that P(x,y) is critical in the aspect ratio $a = {\\cal M}/{\\cal N}$ at a value $a_c =[1-y^2-x(1-y)^2]/2y^2$ where P(x,y) is discontinuous, and the critical exponent of the correlation length for $a < a_c$ is $\

L. C. Chen; F. Y. Wu

2005-11-19

316

Fire spread and percolation in polydisperse compartment structures  

NASA Astrophysics Data System (ADS)

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.

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

2012-11-01

317

Percolation modeling of self-damaging of composite materials  

NASA Astrophysics Data System (ADS)

We propose the concept of autonomous self-damaging in 搒mart composite materials, controlled by activation of added nanosize 揹amaging 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 搒mart material's response involving not just damaging but also healing capsules.

Domanskyi, Sergii; Privman, Vladimir

2014-07-01

318

Asymptotic Dynamics of Coined Quantum Walks on Percolation Graphs  

NASA Astrophysics Data System (ADS)

Quantum walks obey unitary dynamics: they form closed quantum systems. The system becomes open if the walk suffers from imperfections represented as missing links on the underlying basic graph structure, described by dynamical percolation. Openness of the system抯 dynamics creates decoherence, leading to strong mixing. We present a method to analytically solve the asymptotic dynamics of coined, percolated quantum walks for a general graph structure. For the case of a circle and a linear graph we derive the explicit form of the asymptotic states. We find that a rich variety of asymptotic evolutions occur: not only the fully mixed state, but other stationary states; stable periodic and quasiperiodic oscillations can emerge, depending on the coin operator, the initial state, and the topology of the underlying graph.

Koll醨, B.; Kiss, T.; Novotn, J.; Jex, I.

2012-06-01

319

Percolation in aggregates of nanoclusters immersed in superfluid helium  

NASA Astrophysics Data System (ADS)

Impurity-helium condensates created by injection of hydrogen (deuterium) atoms and molecules as well as rare gas (RG) atoms (Ne and Kr) into superfluid He4 have been studied via electron spin resonance (ESR) techniques. Measurements of the ground-state spectroscopic parameters of hydrogen and deuterium atoms show that the nanoclusters have a shell structure. H and D atoms reside in solid molecular layers of H2 and D2, respectively. These layers form on the surfaces of RG (Ne or Kr) nanoclusters. By monitoring the recombination of H atoms in the collection of hydrogen-neon nanoclusters, we show that nanoclusters form a gel-like porous structure which enables the H atoms to be transported through the structure via percolation. Observation of percolation in the collection of nanoclusters containing stabilized hydrogen atoms may open possibilities for a search for macroscopic collective quantum phenomena at ultralow temperatures accessible by a dilution refrigerator.

Mao, S.; Meraki, A.; Boltnev, R. E.; Khmelenko, V. V.; Lee, D. M.

2014-04-01

320

New approaches to recycling tires  

SciTech Connect

Steel-belted radial tires are potentially one of the most recyclable products created by modern industry, although the potential has been barely tapped. Discarded tires pile up at an astonishing rate each year - 234 million in the US and 26 million passenger tire equivalents in Canada. They represent a mother lode of raw material waiting for modern day miners to transform them into recycled rubber, steel, fiber and energy. The tremendous increase in use of steel belted radials since the early 1970s has complicated their recyclability compared to the bias ply tire, but it has also accomplished waste reduction by tripling tire service life. Part one of this report describes processes being developed to convert tires to crumb rubber, as well as some potential uses of recycled rubber. Part two, to appear next month, will examine such uses as rubberized athletic tracks and highway asphalt.

Spencer, R.

1991-03-01

321

Make Your Own Recycled Paper  

NSDL National Science Digital Library

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.

Center for Engineering Educational Outreach,

322

The College that Recycled Itself  

ERIC Educational Resources Information Center

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)

Lawrimore, Earl

1978-01-01

323

Corporate America urges consumers to buy recycled  

SciTech Connect

The National Recycling Coalition`s (NRC, Washington, DC) buy Recycled Business Alliance (BRBA), the US EPA`s WasteWi$e program, and the US Conference of Mayors` (Washington, DC) buy-recycled program are just a few of the national groups that have formed since 1990 to encourage the purchase of products made from recyclables. Indeed, corporate America and governments are buying recycled. More than $1 billion worth of recycled-content products have been bought by McDonald`s Corp. since 1990. The nearly 950 members of the BRBA reported spending $9.1 billion on recycled-content products in 1993. State governments reported in 1993 that they had spent more than $600 million on recycled products. Several states, cities, and counties have adopted buy-recycled executive orders. Now, many of these companies and government officials are urging consumers to use their own purchasing power to spur markets for recyclables.

Rabasca, L.

1995-04-01

324

Percolation model of polydisperse composite solid propellant combustion  

Microsoft Academic Search

The composition dependence of the burn rate of polydisperse composite solid propellants is predicted by analyzing the least-time path of the burn front through the propellant. The predicted burn rate is the average burn rate along the least-time path divided by the tortuosity, or arc length per streamwise interval, of the least-time path. The tortuosity analysis is based on percolation

A KERSTEIN

1987-01-01

325

Percolation of Water Through Pullman Soils: Texas High Plains.  

E-print Network

B-1110 July 1971 ~ercolation of Water Through Pullman Soils Texas High Plains ,- 'b ' L. Texas A&M University The Texas Agricultural Experiment Station H. 0. Kunkel, Acting Director, College Station, Texas Percolation of Water Through... Pullman Soils Texas High Plains I I Summary Nine locations including both irrigated and nonirrigated lands were explored for moisture penetration beneath the Pullman clay loam. It was concluded that, except for those irrigated areas with an extended...

Aronovici, V. S.

1971-01-01

326

Network Robustness and Fragility: Percolation on Random Graphs  

Microsoft Academic Search

Recent work on the internet, social networks, and the power grid has\\u000aaddressed the resilience of these networks to either random or targeted\\u000adeletion of network nodes. Such deletions include, for example, the failure of\\u000ainternet routers or power transmission lines. Percolation models on random\\u000agraphs provide a simple representation of this process, but have typically been\\u000alimited to graphs

Duncan S. Callaway; M. E. J. Newman; Steven H. Strogatz; Duncan J. Watts

2000-01-01

327

Rapidity long range correlations, parton percolation and color glass condensate  

E-print Network

The similarities between string percolation and Glasma results are emphasized, special attention being paid to rapidity long range correlations, ridge structure and elliptic flow. As the string density of high multiplicity pp collisions at LHC energies has similar value as the corresponding to Au-Au semi-central collisions at RHIC we also expect in pp collisions long rapidity correlations and ridge structure, extended more than 8 units in rapidity.

I. Bautista; J. Dias de Deus; C. Pajares

2010-11-08

328

Vector Percolation Analysis of Triglyceride-based Thermoset Polymers  

NASA Astrophysics Data System (ADS)

Thermosetting Acrylated triglycerides (ATG) were prepared from various oils and model triglycerides. The distribution of acrylate groups was calculated from the distribution of unsaturation sites on unmodified oils, assuming a binomial distribution of acrylate groups. The ATG were both homopolymerized and copolymerized with styrene. The cross-link density v, of the polymers was calculated using the recursive method of Miller and Macosko from a knowledge of the acrylate distribution. The cross-link density was found to increase with the level of acrylation A, in a vector percolation manner, and the trends in the cross-link density predictions matched the experimental results. The deviation in the experimental results and model predictions were the result of intramolecular cross-linking. Approximately 0.5 and 0.8 acrylates per triglyceride were lost to intramolecular cyclization for homopolymerized acrylated triglycerides and triglycerides copolymerized with styrene, respectively. Equations for the level of perfection p, of the triglyceride networks and the percolation threshold pc, were developed using the calculated number of acrylates lost to cyclization. Polymers with p < 0.1 without styrene, and p < 0.39 with styrene did not have mechanical integrity, validating the definition of the level of perfection and percolation threshold pc. The tensile strength, S [p-p]^1/2 and modulus E [p-pc]^3 , were in accord with vector percolation theory, where p could be derived experimentally via A [p-pc] , v A and FTIR analysis of the extent of reaction of the C=C groups. These results also indicated how mechanical properties were controlled by the fatty acid distribution function of the plant oils, and which oil would give the best particular property. Supported by EPA and DoE.

Lascala, John J.; Wool, Richard P.

2003-03-01

329

Traveling time and traveling length in critical percolation clusters  

Microsoft Academic Search

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

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

1999-01-01

330

Proliferation aspects of plutonium recycling  

Microsoft Academic Search

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

Bruno Pellaud

2002-01-01

331

Percolation and cooperation with mobile agents: Geometric and strategy clusters  

NASA Astrophysics Data System (ADS)

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.

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

2014-08-01

332

The Fermi paradox: An approach based on percolation theory  

NASA Technical Reports Server (NTRS)

If even a very small fraction of the hundred billion stars in the galaxy are home to technological civilizations which colonize over interstellar distances, the entire galaxy could be completely colonized in a few million years. The absence of such extraterrestrial civilizations visiting Earth is the Fermi paradox. A model for interstellar colonization is proposed using the assumption that there is a maximum distance over which direct interstellar colonization is feasible. Due to the time lag involved in interstellar communications, it is assumed that an interstellar colony will rapidly develop a culture independent of the civilization that originally settled it. Any given colony will have a probability P of developing a colonizing civilization, and a probability (1-P) that it will develop a non-colonizing civilization. These assumptions lead to the colonization of the galaxy occuring as a percolation problem. In a percolation problem, there will be a critical value of percolation probability, P(sub c). For P less than P(sub c), colonization will always terminate after a finite number of colonies. Growth will occur in 'clusters', with the outside of each cluster consisting of non-colonizing civilizations. For P greater than P(sub c), small uncolonized voids will exist, bounded by non-colonizing civilizations. For P approximately = to P(sub c), arbitrarily large filled regions exist, and also arbitrarily large empty regions.

Landis, Geoffrey A.

1993-01-01

333

Controlling electrical percolation in multicomponent carbon nanotube dispersions.  

PubMed

Carbon nanotube reinforced polymeric composites can have favourable electrical properties, which make them useful for applications such as flat-panel displays and photovoltaic devices. However, using aqueous dispersions to fabricate composites with specific physical properties requires that the processing of the nanotube dispersion be understood and controlled while in the liquid phase. Here, using a combination of experiment and theory, we study the electrical percolation of carbon nanotubes introduced into a polymer matrix, and show that the percolation threshold can be substantially lowered by adding small quantities of a conductive polymer latex. Mixing colloidal particles of different sizes and shapes (in this case, spherical latex particles and rod-like nanotubes) introduces competing length scales that can strongly influence the formation of the system-spanning networks that are needed to produce electrically conductive composites. Interplay between the different species in the dispersions leads to synergetic or antagonistic percolation, depending on the ease of charge transport between the various conductive components. PMID:21478868

Kyrylyuk, Andriy V; Hermant, Marie Claire; Schilling, Tanja; Klumperman, Bert; Koning, Cor E; van der Schoot, Paul

2011-06-01

334

Loopless nontrapping invasion-percolation model for fracking  

NASA Astrophysics Data System (ADS)

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.

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

2014-02-01

335

The Persistent Percolation of Single-Stream Voids  

E-print Network

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 defin...

Falck, Bridget

2014-01-01

336

Transport pathways within percolating pore space networks of granular materials  

NASA Astrophysics Data System (ADS)

Granular media can be regarded as a mixture of two components: grains and the material filling the voids or pores between the grains. Pore properties give rise to a range of applications such as modelling ground water flow, carbon capture and sequestration. The grains within a dense granular material respond to deformation (e.g., shearing or compression) by rearranging to create local zones of compression and zones of dilatation (i.e., regions of high pore space). Descriptions of the deformation are typically focused on analysis of the solid skeleton via topology of physical contact networks of grains but an alternative perspective is to consider network representations of the evolving anisotropic pore space. We demonstrate how to construct pore space networks that express the local size of voids about a grain through network edge weights. We investigate sectors of the loading history when a percolating giant component of the pore space network exists. At these states the grains are in a configuration more prone to the efficient transport of material (e.g., fluid flow, mineral/gas deposits). These pathways can be found through examination of the weighted shortest paths percolating the boundaries of the material. In particular, network weights biased towards large void space results in efficient percolating pathways traversing the shear band in the direction of principal stress within a 2D granular assembly subject to high strains.

Vo, Kevin; Walker, David M.; Tordesillas, Antoinette

2013-06-01

337

Diffusion trapping times and dynamic percolation in an Ising system.  

PubMed

We address the problem of diffusion through dynamic Ising network structures using random walkers (RWs) whose net displacements are partitioned into two contributions, arising from (1) transport through neighboring "conducting" clusters and (2) self-diffusion of the site on which the RW finds itself, respectively. At finite temperatures, the conducting clusters in the network exhibit correlated dynamic behavior, making our model system different to most prior published work, which has largely been at the random percolation limit. We also present a novel heuristic scaling analysis for this system that utilizes a new scaling exponent theta(z) for representing RW trapping time as a function of "distance" from the dynamic percolation transition. Simulation results in two-dimensional networks show that when theta(z) = 2, a value found from independent physical arguments, our scaling equations appear to capture universal behavior in the system, at both the random percolation (infinite temperature) and finite temperature conditions studied. This study suggests that the model and the scaling approach given here should prove useful for studying transport in physical systems showing dynamic disorder. PMID:18624546

Chen, C-L; Shapir, Y; Chimowitz, E H

2008-07-14

338

Loopless nontrapping invasion-percolation model for fracking.  

PubMed

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

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

2014-02-01

339

Vapor Phase Catalytic Ammonia Reduction  

NASA Technical Reports Server (NTRS)

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.

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

1994-01-01

340

Highly compressed ammonia forms an ionic crystal  

NASA Astrophysics Data System (ADS)

Ammonia is an important compound with many uses, such as in the manufacture of fertilizers, explosives and pharmaceuticals. As an archetypal hydrogen-bonded system, the properties of ammonia under pressure are of fundamental interest, and compressed ammonia has a significant role in planetary physics. We predict new high-pressure crystalline phases of ammonia (NH3) through a computational search based on first-principles density-functional-theory calculations. Ammonia is known to form hydrogen-bonded solids, but we predict that at higher pressures it will form ammonium amide ionic solids consisting of alternate layers of NH4+ and NH2- ions. These ionic phases are predicted to be stable over a wide range of pressures readily obtainable in laboratory experiments. The occurrence of ionic phases is rationalized in terms of the relative ease of forming ammonium and amide ions from ammonia molecules, and the volume reduction on doing so. We also predict that the ionic bonding cannot be sustained under extreme compression and that, at pressures beyond the reach of current static-loading experiments, ammonia will return to hydrogen-bonded structures consisting of neutral NH3 molecules.

Pickard, Chris J.; Needs, R. J.

2008-10-01

341

INFRARED SPECTRA OF AMMONIA-WATER ICES  

SciTech Connect

We conducted a systematic study of the near-IR and mid-IR spectra of ammonia-water ices at various NH{sub 3}/H{sub 2}O ratios. The differences between the spectra of amorphous and crystalline ammonia-water ices were also investigated. The 2.0 {mu}m ammonia band central wavelength is a function of the ammonia/water ratio. It shifts from 2.006 {+-} 0.003 {mu}m (4985 {+-} 5 cm{sup -1}) to 1.993 {+-} 0.003 {mu}m (5018 {+-} 5 cm{sup -1}) as the percentage of ammonia decreases from 100% to 1%. The 2.2 {mu}m ammonia band center shifts from 2.229 {+-} 0.003 {mu}m (4486 {+-} 5 cm{sup -1}) to 2.208 {+-} 0.003 {mu}m (4528 {+-} 5 cm{sup -1}) over the same range. Temperature-dependent shifts of those bands are below the uncertainty of the measurement, and therefore are not detectable. These results are important for comparison with astronomical observations as well as for estimating the concentration of ammonia in outer solar system ices.

Zheng Weijun; Jewitt, David [Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States); Kaiser, Ralf I. [Department of Chemistry, University of Hawaii, Honolulu, HI 96822 (United States)], E-mail: jewitt@ifa.hawaii.edu, E-mail: ralfk@hawaii.edu, E-mail: zhengwj@iccas.ac.cn

2009-03-15

342

Depletion of Ammonia Gas onto Jovian Ices  

NASA Astrophysics Data System (ADS)

The altitude profile of ammonia in Jupiter抯 atmosphere, as constrained by microwave spectra, is poorly understood. The microwave spectrum of Jupiter is consistent with supersolar ammonia deeper than 6 bar, and subsolar ammonia at pressures less than 2 bar. In addition, the Galileo Probe Mass Spectrometer measured a deep NH3/H2 mixing ratio of approximately five times the protosolar ratio. Consequently, a global-scale depletion mechanism for ammonia gas can be anticipated, operating between the 2 and 6 bar levels. Candidate depletion mechanisms include dynamics, condensation of species with higher nitrogen fractions than NH4SH (including clathrates), and adsorption of ammonia onto NH4SH or water ices. Measured uptake coefficients of ammonia provide valuable constraints for model calculations testing the ammonia depletion hypothesis in Jupiter抯 atmosphere. We have begun laboratory experiments designed to measure the uptake of ammonia by H2O and H2O-NH4SH ice mixtures with a Knudsen cell apparatus in the temperature range 130-250 K. These conditions are appropriate to the troposphere of Jupiter around the 2-4 bar pressure level. Initial results show that the uptake coefficient is larger than 10-4 in this temperature range. We also plan model calculations to apply the experimental results to Jupiter's atmosphere and will discuss the key parameters and processes that influence the ammonia uptake and their relevance to Jupiter's atmosphere. This work is supported by the NASA Planetary Atmospheres Program under grant NNX09AB69G.

Kasper, T.; Wong, M. H.; Marschall, J.; de Pater, I.; Romani, P. N.; Kalogerakis, K.

2010-12-01

343

1. Recycle all bottles and cans 2. Recycle all personal electronics  

E-print Network

RECYCLING 1. Recycle all bottles and cans 2. Recycle all personal electronics 3. Bring your own PREVENTION 32. Dispose of all cigarette butts properly 33. Use cloth napkins as much as possible 34. Reuse

Howitt, Ivan

344

50 Simple Things Kids Can Do To Recycle. California Edition.  

ERIC Educational Resources Information Center

This book provides 50 recycling ideas for children and features Recycle Rex, the state of California's "spokesdinosaur" for recycling. An introduction contains recycling background information on waste disposal options and reducing, reusing, and recycling. Recycling suggestions are divided into nine sections: (1) "Learn What You Can Recycle"

Javna, John

345

Ammonia volatilization in soil treated with tannery sludge.  

PubMed

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 Rol鈔dia (Paran 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

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

346

The Ammonia Freeze Explosion (AFEX) process  

SciTech Connect

The Ammonia Freeze Explosion (AFEX) process treats lignocellulose with high-pressure liquid ammonia, and then explosively releases the pressure. The combined chemical effect (cellulose decrystallization) and physical effect (increased accessible surface area) dramatically increase lignocellulose susceptibility to enzymatic attack. There are many adjustable parameters in the AFEX process: ammonia loading, water loading, temperature, time, blowdown pressure, and number of treatments. The effect of these parameters on enzymatic susceptibility was explored for three materials: Coastal bermudagrass, bagasse, and newspaper. Nearly quantitative sugar yields were demonstrated for Coastal bermudagrass and bagasse, using a very low enzyme loading (5 IU/g). Newspaper proved to be much more resistant to enzymatic hydrolysis.

Holtzapple, M.T.; Jae-Hoon Jun; Ganesh Ashok; Patibandla, S.L.; Dale, B.E. [Texas A& M Univ., College Station, TX (United States)

1991-12-31

347

Ionization of carbon acids in liquid ammonia.  

PubMed

The acidities of various carbon acids in liquid ammonia (LNH(3)) at room temperature were determined by NMR and rates of D-exchange. There is a reasonable linear correlation of the pK(a)s in LNH(3) with those in water and DMSO of slope 0.7 and 0.8, respectively. Carbon acids with an aqueous pK(a) of less than 12 are fully ionized in liquid ammonia. Nucleophilic substitution of benzyl chloride by carbanions in liquid ammonia generates a Br鴑sted ?(nuc) = 0.38. PMID:22026552

Ji, Pengju; Powles, Nicholas T; Atherton, John H; Page, Michael I

2011-11-18

348

Femtosecond multiphoton ionization of ammonia clusters  

SciTech Connect

Herein, we report on femtosecond time-resolved experiments in ammonia clusters. The mechanisms of their ionization and the subsequent formation of the protonated ammonia cluster ions are studied using a femtosecond pump-probe technique at 620 nm. It is found that an intermediate corresponding to [ital C][prime] states of the monomer is responsible for the ionization of ammonia clusters. Femtosecond pump--probe studies show that the lifetime of the intermediate to the formation of the protonated cluster ions (NH[sub 3])[sub [ital n

Wei, S.; Purnell, J.; Buzza, S.A.; Stanley, R.J.; Castleman, A.W. Jr. (Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States))

1992-12-15

349

Technology Offer Ammonia and Humidity Sensor for the  

E-print Network

Technology Offer Ammonia and Humidity Sensor for the Detection of Food Spoilage Keywords Ammonia. Overview The measurement of ammonia at ultra-low concentrations at varying levels of humidity is a challenging task but is highly promising, as it allows the detection of ammonia produced by bacteria upon

350

Potential of High-Throughput Experimentation with Ammonia Borane  

E-print Network

Potential of High-Throughput Experimentation with Ammonia Borane Solid Hydrogen Storage Materials) 颅 In-situ spectroscopy and mechanistic investigations (amine boranes; T = 5 颅 500K) at PNNL #12;Ammonia #12;Thermolysis of Ammonia Borane 路 Ammonia borane releases a hydrogen molecule, forming

351

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...

352

Process for hydrogen recovery from ammonia purge gases  

Microsoft Academic Search

Ammonia synthesis processes are disclosed which provide enhanced recovery of hydrogen from ammonia synthesis purge streams by selective permeation. The enhanced recovery of hydrogen can provide increased conversion of hydrogen values to ammonia. In the processes, a purge stream from an ammonia synthesis loop at a superatmospheric pressure is passed to at least two permeator stages in series. Each permeator

T. E. Graham; D. L. MacLean

1979-01-01

353

EVALUATION AND MANAGEMENT OF AMMONIA EMISSIONS FROM POULTRY LITTER  

Technology Transfer Automated Retrieval System (TEKTRAN)

Ammonia volatilization from poultry litter results in high levels of ammonia in poultry facilities, which negatively impacts bird performance and worker health. Ammonia emissions from the houses also cause atmospheric ammonia contamination. Although there is a tremendous concern about these emissio...

354

Amino acids control ammonia pulses in yeast colonies  

Microsoft Academic Search

Individual yeast colonies produce pulses of volatile ammonia separated by phases of medium acidification. Colonies of Saccharomyces cerevisiae mutant defective in the general amino acid permease, Gap1p, exhibit decreased ammonia production. Mutations in the S. cerevisiae amino acid sensor SPS completely abolish the colony ammonia pulses. In contrast, the ammonia pulse production is independent of external concentrations of ammonium and

Blanka Zik醤ov; Martin Kuthan; Mark閠a ?i?icov; Jitka Forstov; Zdena Palkov

2002-01-01

355

Deep Recycling of Carbon  

NASA Astrophysics Data System (ADS)

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.

Schmidt, M. W.

2012-12-01

356

Septic wastewater treatment using recycled rubber particles as biofiltration media.  

PubMed

Performance of the laboratory-scale recycled rubber particles (RRP) biofilter was compared to a conventional gravel system and a peat biofilter for treatment of septic tank effluent. During the study, the RRP biofilter provided similar or better performance than other systems in terms of organic removal and hydraulic capacity. After the start-up period, RRP biofilter achieved removal efficiencies for BOD5, total suspended solids (TSS), ammonia nitrogen of 96%, 93%, and 90%, respectively, over the range of hydraulic loading rates of 57-204 L/m2/d. On the other hand, the peat biofilter failed hydraulically and the gravel system showed high TSS concentrations in the effluent. RRP provided high surface area and sufficient time for biological treatment. In addition, RRP was observed to provide ammonia adsorption capacity. The results showed that RRP has the potential to be used as substitutes for natural aggregate such as gravel in septic system drainfields. The RRP biofilter can be used as alternative septic systems for the sites where an existing septic system has failed or site conditions, such as high groundwater table or small lot size, are not suitable for the installation of conventional septic systems. PMID:24645443

Oh, Jin Hwan; Park, Jaeyoung; Ellis, Timothy G

2014-01-01

357

PRESENT CONDITION OF FOOD WASTE RECYCLING LOOP BASED ON RECYCLING PROJECT CERTIFICATION OF THE FOOD WASTE RECYCLING LAW  

NASA Astrophysics Data System (ADS)

Purpose of this research is to clear present condition of food waste recycling loops based on recycling project certification of the Food Waste Recycling Law. Method of this research is questionnaire survey to companies constituting the loops. Findings of this research are as follows: 1. Proponents of the loop is most often the recycling companies. 2. Food waste recycling rate is 61% for the food retailing industry and 81% for the food service industry. These values are higher than the national average in 2006. The effect of the revision of recycling project certification is suggested.

Kita, Tomoko; Kanaya, Ken

358

Quarkyonic percolation and deconfinement at finite density and number of colors  

NASA Astrophysics Data System (ADS)

We examine the interplay between the percolation and the deconfinement phase transitions of Yang-Mills matter at finite temperature, quark chemical potential ?Q, and number of colors Nc. We find that, whereas the critical Nc for percolation goes down with density, the critical Nc for confinement generally goes up. Because of this, Yang-Mills matter falls into two qualitatively different regimes: the 搇ow-Nc limit, where percolation does not occur because matter deconfines before it percolates, and the 揾igh-Nc limit, where there are three distinct phases梒onfined, deconfined, and confined but percolating matter梒haracterizing Yang-Mills matter at finite temperature and density. The latter can be thought of as the recently conjectured 搎uarkyonic phase. We attempt an estimate of the critical Nc to see if the percolating phase can occur in our world. We find that, while percolation will not occur at normal nuclear density as in the large-Nc limit, a sliver of the phase diagram in Nc, energy density and baryonic density where percolation occurs while confinement persists is possible. We conclude by speculating on the phenomenological properties of such percolating 搎uarkyonic matter and suggesting avenues by which to study it quantitatively and to look for it in experiment.

Lottini, Stefano; Torrieri, Giorgio

2013-08-01

359

Incorporating variability into an approximation formula for bond percolation thresholds of planar periodic lattices  

NASA Astrophysics Data System (ADS)

Approximation formulas to predict values for bond percolation thresholds of periodic graphs make use of certain features of lattice graphs such as dimension and average degree. We show that a relationship exists between the average and second-moment of the degree of a graph and the average degree of its line graph. Using this relationship together with the well-known bond-to-site transformation between the bond percolation model on a graph and the site percolation model on its line graph, we create a new approximation formula that improves the accuracy of bond percolation threshold predictions.

Wierman, John C.; Naor, Dora Passen; Smalletz, Jonathan

2007-01-01

360

Incorporating variability into an approximation formula for bond percolation thresholds of planar periodic lattices.  

PubMed

Approximation formulas to predict values for bond percolation thresholds of periodic graphs make use of certain features of lattice graphs such as dimension and average degree. We show that a relationship exists between the average and second-moment of the degree of a graph and the average degree of its line graph. Using this relationship together with the well-known bond-to-site transformation between the bond percolation model on a graph and the site percolation model on its line graph, we create a new approximation formula that improves the accuracy of bond percolation threshold predictions. PMID:17358117

Wierman, John C; Naor, Dora Passen; Smalletz, Jonathan

2007-01-01

361

Characterization of atmospheric ammonia near Fort Worth, TX Part II. Impact of ammonia on particulate matter formation  

E-print Network

1 Characterization of atmospheric ammonia near Fort Worth, TX 颅 Part II. Impact of ammonia-phase ammonia (NH3) and acidic trace gases such as nitric acid (HNO3) and hydrochloric acid (HCl) were collected contributed to the increased particle concentration at high RH. Keywords: ammonia, particulate matter, gas

362

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

E-print Network

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

Paris-Sud XI, Universit茅 de

363

Modeling and simulation of ammonia removal from purge gases of ammonia plants using a catalytic Pd朅g membrane reactor  

Microsoft Academic Search

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

M. R. Rahimpour; A. Asgari

2008-01-01

364

Novel Regenerated Solvent Extraction Processes for the Recovery of Carboxylic Acids or Ammonia from Aqueous Solutions Part II. Recovery of Ammonia from Sour Waters  

SciTech Connect

Two novel regenerated solvent extraction processes are examined. The first process has the potential to reduce the energy costs inherent in the recovery of low-volatility carboxylic acids from dilute aqueous solutions. The second process has the potential for reducing the energy costs required for separate recovery of ammonia and acid gases (e.g. CO{sub 2} and H{sub 2}S) from industrial sour waters. The recovery of carboxylic acids from dilute aqueous solution can be achieved by extraction with tertiary amines. An approach for regeneration and product recovery from such extracts is to back-extract the carboxylic acid with a water-soluble, volatile tertiary amine, such as trimethylamine. The resulting trimethylammonium carboxylate solution can be concentrated and thermally decomposed, yielding the product acid and the volatile amine for recycle. Experimental work was performed with lactic acid, SUCCiOlC acid, and fumaric acid. Equilibrium data show near-stoichiometric recovery of the carboxylic acids from an organic solution of Alamine 336 into aqueous solutions of trimethylamine. For fumaric and succinic acids, partial evaporation of the aqueous back extract decomposes the carboxylate and yields the acid product in crystalline form. The decomposition of aqueous solutions of trimethylammonium lactates was not carried out to completion, due to the high water solubility of lactic acid and the tendency of the acid to self-associate. The separate recovery of ammonia and acid gases from sour waters can be achieved by combining steam-stripping of the acid gases with simultaneous removal of ammonia by extraction with a liquid cation exchanger. The use of di-2,4,4-trimethylpentyl phosphinic acid as the liquid cation exchanger is explored in this work. Batch extraction experiments were carried out to measure the equilibrium distribution ratio of ammonia between an aqueous buffer solution and an organic solution of the phosphinic acid (0.2N) in Norpar 12. The concentration-based distribution ratios increase from 0.11 to 0.46 as the aqueous phase pH increases from 7.18 to 8.15. Regeneration of the organic extractant solution was carried out by stripping at elevated temperatures to remove the ammonia, with 99% recovery of the ammonia being obtained at 125 C.

Poole, L.J.; King, C.J.

1990-03-01

365

Stimulation of thaumarchaeal ammonia oxidation by ammonia derived from organic nitrogen but not added inorganic nitrogen.  

PubMed

Ammonia oxidation, the first step in nitrification, is performed by autotrophic bacteria and thaumarchaea, whose relative contributions vary in different soils. Distinctive environmental niches for the two groups have not been identified, but evidence from previous studies suggests that activity of thaumarchaea, unlike that of bacterial ammonia oxidizers, is unaffected by addition of inorganic N fertilizer and that they preferentially utilize ammonia generated from the mineralization of organic N. This hypothesis was tested by determining the influence of both inorganic and organic N sources on nitrification rate and ammonia oxidizer growth and community structure in microcosms containing acidic, forest soil in which ammonia oxidation was dominated by thaumarchaea. Nitrification rate was unaffected by the incubation of soil with inorganic ammonium but was significantly stimulated by the addition of organic N. Oxidation of ammonia generated from native soil organic matter or added organic N, but not added inorganic N, was accompanied by increases in abundance of the thaumarchaeal amoA gene, a functional gene for ammonia oxidation, but changes in community structure were not observed. Bacterial amoA genes could not be detected. Ammonia oxidation was completely inhibited by 0.01% acetylene in all treatments, indicating ammonia monooxygenase-dependent activity. The findings have implications for current models of soil nitrification and for nitrification control strategies to minimize fertilizer loss and nitrous oxide production. PMID:22150211

Levi?nik-H鰂ferle, Spela; Nicol, Graeme W; Ausec, Luka; Mandi?-Mulec, Ines; Prosser, James I

2012-04-01

366

DWPF Recycle Evaporator Simulant Tests  

SciTech Connect

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 characterization of actual recycle streams from DWPF and input from DWPF-Engineering. The simulated feed was evaporated in laboratory scale apparatus to target a 30X volume reduction. Condensate and concentrate samples from each run were analyzed and the process characteristics (foaming, scaling, etc) were visually monitored during each run. The following conclusions were made from the testing: Concentration of the ''typical'' recycle stream in DWPF by 30X was feasible. The addition of DWTT recycle streams to the typical recycle stream raises the solids content of the evaporator feed considerably and lowers the amount of concentration that can be achieved. Foaming was noted during all evaporation tests and must be addressed prior to operation of the full-scale evaporator. Tests were conducted that identified Dow Corning 2210 as an antifoam candidate that warrants further evaluation. The condensate has the potential to exceed the ETP WAC for mercury, silicon, and TOC. Controlling the amount of equipment decontamination recycle in the evaporator blend would help meet the TOC limits. The evaporator condensate will be saturated with mercury and elemental mercury will collect in the evaporator condensate collection vessel. No scaling on heating surfaces was noted during the tests, but splatter onto the walls of the evaporation vessels led to a buildup of solids. These solids were difficult to remove with 2M nitric acid. Precipitation of solids was not noted during the testing. Some of the aluminum present in the recycle streams was converted from gibbsite to aluminum oxide during the evaporation process. The following recommendations were made: Recycle from the DWTT should be metered in slowly to the ''typical'' recycle streams to avoid spikes in solids content to allow consistent processing and avoid process upsets. Additional studies should be conducted to determine acceptable volume ratios for the HEME dissolution and decontamination solutions in the evaporator feed. Dow Corning 2210 antifoam should be evaluated for use to control foaming. Additional tests are required to determine the concentration of antifoam required to prevent foaming during startup, the frequency of antifoam additions required to control foaming during steady state processing, and the ability of the antifoam to control foam over a range of potential feed compositions. This evaluation should also include evaluation of the degradation of the antifoam and impact on the silicon and TOC content of the condensate. The caustic HEME dissolution recycle stream should be neutralized to at least pH of 7 prior to blending with the acidic recycle streams. Dow Corning 2210 should be used during the evaporation testing using the radioactive recycle samples received from DWPF. Evaluation of additional antifoam candidates should be conducted as a backup for Dow Corning 2210. A camera and/or foam detection instrument should be included in the evaporator design to allow monitoring of the foaming behavior during operation. The potential for foam formation and high solids content should be considered during the design of the evaporator vessel.

Stone, M

2005-04-05

367

Ammonia, the \\Atilde;?\\Xtilde transition  

NASA Astrophysics Data System (ADS)

A new hypothesis regarding the dynamics of ammonia in the?X榯ransition is implemented. Unlike previous hypotheses, it is able to accurately reproduce the observed frequencies and account for the irregular band spacings and the asymmetric band shapes.

Tang, Sandra L.; Imre, Dan G.

1988-02-01

368

INVESTIGATION OF THE ORION RESEARCH AMMONIA MONITOR  

EPA Science Inventory

The Orion Research ammonia monitor was investigated using the Orion specifications and environmental considerations as a guide. Laboratory tests under controlled environmental conditions showed the electronic stability (drift) to be well within + or - 10 percent of reading over t...

369

High-pressure studies of ammonia hydrates  

E-print Network

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 ...

Wilson, Craig W.

2014-06-28

370

DEVELOPMENT AND SELECTION OF AMMONIA EMISSION FACTORS  

EPA Science Inventory

This report compiles recent literature on ammonia (NH') emission factors for application in the United States. ost of the recent research supports acid deposition studies in the European community (specifically, the Netherlands, Great Britain, and Scandinavia) but some research h...

371

Inverse Modeling of Ammonia Daven K. Henze  

E-print Network

Separation Characteristics Other #12;3 Access WetlandsAccess Wetlands Wetland 1 Wetland 4 Wetland 2 Wetland 3 颅 Turbidity: 路 LaMotte庐 colorimeter 颅 Ammonia nitrogen, nitrite, nitrate and phosphate: 路 LaMotte庐 water

372

Recycling of polymers: a review.  

PubMed

Plastics are inexpensive, easy to mold, and lightweight. These and many other advantages make them very promising candidates for commercial applications. In many areas, they have substantially suppressed traditional materials. However, the problem of recycling still is a major challenge. There are both technological and economic issues that restrain the progress in this field. Herein, a state-of-art overview of recycling is provided together with an outlook for the future by using popular polymers such as polyolefins, poly(vinyl chloride), polyurethane, and poly(ethylene terephthalate) as examples. Different types of recycling, primary, secondary, tertiary, quaternary, and biological recycling, are discussed together with related issues, such as compatibilization and cross-linking. There are various projects in the European Union on research and application of these recycling approaches; selected examples are provided in this article. Their progress is mirrored by granted patents, most of which have a very limited scope and narrowly cover certain technologies. Global introduction of waste utilization techniques to the polymer market is currently not fully developed, but has an enormous potential. PMID:24811748

Ignatyev, Igor A; Thielemans, Wim; Vander Beke, Bob

2014-06-01

373

Mechanisms of Ammonia Excretion Across Fish Gills  

Microsoft Academic Search

Although it has been a subject of considerable research, many questions regarding the mechanism(s) of ammonia excretion (JAmm) across fish gills remain unresolved. Recent advances improving our understanding of the linkage between CO2 and ammonia excretion, and the likelihood that H+-ATPases are present in freshwater fish gills, should improve our understanding about mechanisms of branchial JAmm. Moreover, basic differences in

Michael P. Wilkie

1997-01-01

374

Corrosion inhibitor for aqueous ammonia absorption system  

DOEpatents

A method of inhibiting corrosion and the formation of hydrogen and thus improving absorption in an ammonia/water absorption refrigeration, air conditioning or heat pump system by maintaining the hydroxyl ion concentration of the aqueous ammonia working fluid within a selected range under anaerobic conditions at temperatures up to 425.degree. F. This hydroxyl ion concentration is maintained by introducing to the aqueous ammonia working fluid an inhibitor in an amount effective to produce a hydroxyl ion concentration corresponding to a normality of the inhibitor relative to the water content ranging from about 0.015 N to about 0.2 N at 25.degree. C. Also, working fluids for inhibiting the corrosion of carbon steel and resulting hydrogen formation and improving absorption in an ammonia/water absorption system under anaerobic conditions at up to 425.degree. F. The working fluids may be aqueous solutions of ammonia and a strong base or aqueous solutions of ammonia, a strong base, and a specified buffer.

Phillips, Benjamin A. (Benton Harbor, MI); Whitlow, Eugene P. (St. Joseph, MI)

1998-09-22

375

Ammonia chemistry in a flameless jet  

SciTech Connect

In this paper, the nitrogen chemistry in an ammonia (NH{sub 3}) doped flameless jet is investigated using a kinetic reactor network model. The reactor network model is used to explain the main differences in ammonia chemistry for methane (CH{sub 4})-containing fuels and methane-free fuels. The chemical pathways of nitrogen oxides (NO{sub x}) formation and destruction are identified using rate-of-production analysis. The results show that in the case of natural gas, ammonia reacts relatively late at fuel lean condition leading to high NO{sub x} emissions. In the pre-ignition zone, the ammonia chemistry is blocked due to the absence of free radicals which are consumed by methane-methyl radical (CH{sub 3}) conversion. In the case of methane-free gas, the ammonia reacted very rapidly and complete decomposition was reached in the fuel rich region of the jet. In this case the necessary radicals for the ammonia conversion are generated from hydrogen (H{sub 2}) oxidation. (author)

Zieba, Mariusz; Schuster, Anja; Scheffknecht, Guenter [Institute of Process Engineering and Power Plant Technology, University of Stuttgart, Pfaffenwaldring 23, D-70569 Stuttgart (Germany); Brink, Anders; Hupa, Mikko [Process Chemistry Centre, Aabo Akademi University, Biskopsgatan 8, 20500 Aabo (Finland)

2009-10-15

376

Ammonia as a refrigerant of choice  

SciTech Connect

This paper reports that the greatest potential for a swing to the use of ammonia would be in the following areas: Large, central facility-type air- conditioning applications. Central district heating and cooling systems, with isolated engine room facilities, represent a natural for the advantages of ammonia screw compressor water or glycol chilling over the R-11 replacement systems. Latent heat storage systems. Here, the long history of ammonia systems (primarily in the dairy industry) will bring ammonia back into the picture. This applies to both ice-builder and ice accumulator systems. A large system of this type is being built for an industrial air-conditioning application in the Midwest and should be available shortly for case history write-ups. Packaged water chilling systems in the 30-200 ton capacity range. At least two manufacturers or assemblers are considering offering standard units in this area. The advent and widely increasing use of screw compressors has added to the potential for ammonia applications. (Ammonia was the predominant refrigerant for the first screw compressors.) Use of screw compressors instead of centrifugals is predicted to increase.

Miner, S.M.

1990-12-01

377

Corrosion inhibitor for aqueous ammonia absorption system  

DOEpatents

A method is described for inhibiting corrosion and the formation of hydrogen and thus improving absorption in an ammonia/water absorption refrigeration, air conditioning or heat pump system by maintaining the hydroxyl ion concentration of the aqueous ammonia working fluid within a selected range under anaerobic conditions at temperatures up to 425 F. This hydroxyl ion concentration is maintained by introducing to the aqueous ammonia working fluid an inhibitor in an amount effective to produce a hydroxyl ion concentration corresponding to a normality of the inhibitor relative to the water content ranging from about 0.015 N to about 0.2 N at 25 C. Also, working fluids for inhibiting the corrosion of carbon steel and resulting hydrogen formation and improving absorption in an ammonia/water absorption system under anaerobic conditions at up to 425 F. The working fluids may be aqueous solutions of ammonia and a strong base or aqueous solutions of ammonia, a strong base, and a specified buffer. 5 figs.

Phillips, B.A.; Whitlow, E.P.

1998-09-22

378

Ammonia in Infrared Dark Clouds  

E-print Network

Infrared Dark Clouds appear to be the long sought population of cold and dense aggregations with the potential of harbouring the earliest stages of massive star formation. Up to now there has been no systematic study on the temperature distribution, velocity fields, chemical and physical state toward this new cloud population. Knowing these properties is crucial for understanding the presence, absence and the very potential of star formation. The present paper aims at addressing these questions. We analyse temperature structures and velocity fields and gain information on their chemical evolution. The gas emission is remarkably coextensive with the extinction seen at infrared wavelengths and with the submillimeter dust emission. Our results show that IRDCs are on average cold (T 100 M_sun), highly turbulent (1 -- 3 km/s) and exhibit significant velocity structure (variations around 1 -- 2 km/s over the cloud). We find an increasing trend in temperature from IRDCs with high ammonia column density to high mass protostellar objects and hot core/Ultracompact Hii regions stages of early warm high-mass star formation while linewidths of IRDCs are smaller. On the basis of this sample, we infer that while active star formation is not yet pervasive in most IRDCs, local condensations might collapse in the future or have already begun forming stars.

Thushara Pillai; Friedrich Wyrowski; Sean J. Carey; Karl M. Menten

2006-01-04

379

Recycler short kicker beam impedance  

SciTech Connect

Measured longitudinal and calculated transverse beam impedance is presented for the short kicker magnets being installed in the Fermilab Recycler. Fermi drawing number ME-457159. The longitudinal impedance was measured with a stretched wire and the Panofsky equation was used to estimate the transverse impedance. The impedance of 3319 meters (the Recycler circumference) of stainless vacuum pipe is provided for comparison. Although measurements where done to 3GHz, impedance was negligible above 30MHz. The beam power lost to the kicker impedance is shown for a range of bunch lengths. The measurements are for one kicker assuming a rotation frequency of 90KHz. Seven of these kickers are being installed.

Crisp, Jim; Fellenz, Brian; /Fermilab

2009-07-01

380

Polymer recycling: opportunities and limitations.  

PubMed Central

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

Stein, R S

1992-01-01

381

Percolation in insect nest networks: Evidence for optimal wiring  

NASA Astrophysics Data System (ADS)

Optimization has been shown to be a driving force for the evolution of some biological structures, such as neural maps in the brain or transport networks. Here we show that insect networks also display characteristic traits of optimality. By using a graph representation of the chamber organization of termite nests and a disordered lattice model, it is found that these spatial nests are close to a percolation threshold. This suggests that termites build efficient systems of galleries spanning most of the nest volume at low cost. The evolutionary consequences are outlined.

Valverde, Sergi; Corominas-Murtra, Bernat; Perna, Andrea; Kuntz, Pascale; Theraulaz, Guy; Sol, Ricard V.

2009-06-01

382

Empires and percolation: stochastic merging of adjacent regions  

NASA Astrophysics Data System (ADS)

We introduce a stochastic model in which adjacent planar regions A, B merge stochastically at some rate ?(A, B) and observe analogies with the well-studied topics of mean-field coagulation and of bond percolation. Do infinite regions appear in finite time? We give a simple condition on ? for this hegemony property to hold, and another simple condition for it to not hold, but there is a large gap between these conditions, which includes the case ?(A, B) ? 1. For this case, a non-rigorous analytic argument and simulations suggest hegemony.

Aldous, D. J.; Ong, J. R.; Zhou, W.

2010-01-01

383

Pathogen Mutation Modeled by Competition Between Site and Bond Percolation  

NASA Astrophysics Data System (ADS)

While disease propagation is a main focus of network science, its coevolution with treatment has yet to be studied in this framework. We present a mean-field and stochastic analysis of an epidemic model with antiviral administration and resistance development. We show how this model maps to a coevolutive competition between site and bond percolation featuring hysteresis and both second- and first-order phase transitions. The latter, whose existence on networks is a long-standing question, imply that a microscopic change in infection rate can lead to macroscopic jumps in expected epidemic size.

H閎ert-Dufresne, Laurent; Patterson-Lomba, Oscar; Goerg, Georg M.; Althouse, Benjamin M.

2013-03-01

384

Percolative phenomena and electrorheological structures in reverse micelles  

NASA Astrophysics Data System (ADS)

Structural relaxations in AOT (sodium bis(2-ethylhexyl) sulphosuccinate) and lecithin reverse micelles are investigated by means of dielectric relaxation and conductivity measurements. The different behaviours exhibited by the two systems are interpreted in terms of the different kinds of interaction between the water and the surfactant molecules. In the case of lecithin, the application of an external electric field induces the establishing of some electrorheological structure. The temperature dependence of the observed electrorheological effects agrees with the hypothesis of a structural arrangement consisting in a percolated network of branched cylindrical micelles. The experimental results are compared with other literature data and discussed within the framework of the current theories.

Aliotta, F.

2002-03-01

385

Evidence of percolative phenomena in a lecithin-based gel  

NASA Astrophysics Data System (ADS)

The structure of the gel-phase, observed in a number of lecithin-in-oil microemulsions after addition of water, is the topic of a controversy actually taking place in the literature. In this paper, we will show how the dynamical properties of water confined in the inner core of the micelles, as investigated by QENS and INS, turn out to be inconsistent with the usually proposed model of entangled (not interconnected) polymer-like micelles. A percolated structure of branched cylindrical aggregates could agree with the presented data.

Aliotta, F.; Vasi, C.; Lechner, R. E.; Ruffle, B.

2000-03-01

386

Dynamical Instability in Boolean Networks as a Percolation Problem  

NASA Astrophysics Data System (ADS)

Boolean networks, a widely used model of gene regulatory networks, exhibit a phase transition between a stable regime, in which small perturbations die out, and an unstable regime, in which small perturbations grow exponentially. We show that this phase transition can be mapped onto a static percolation problem which predicts the critical point and the long-time Hamming distance between perturbed and unperturbed systems. The results, which apply to Boolean networks with a broad class of topologies and update functions, are confirmed by numerical simulations.

Squires, Shane; Girvan, Michelle; Ott, Edward

2012-02-01

387

From damage percolation to crack nucleation through finite size criticality.  

PubMed

We present a unified theory of fracture in disordered brittle media that reconciles apparently conflicting results reported in the literature. Our renormalization group based approach yields a phase diagram in which the percolation fixed point, expected for infinite disorder, is unstable for finite disorder and flows to a zero-disorder nucleation-type fixed point, thus showing that fracture has a mixed first order and continuous character. In a region of intermediate disorder and finite system sizes, we predict a crossover with mean-field avalanche scaling. We discuss intriguing connections to other phenomena where critical scaling is only observed in finite size systems and disappears in the thermodynamic limit. PMID:23683218

Shekhawat, Ashivni; Zapperi, Stefano; Sethna, James P

2013-05-01

388

Tight Lower Bound for Percolation Threshold on an Infinite Graph  

NASA Astrophysics Data System (ADS)

We construct a tight lower bound for the site percolation threshold on an infinite graph, which becomes exact for an infinite tree. The bound is given by the inverse of the maximal eigenvalue of the Hashimoto matrix used to count nonbacktracking walks on the original graph. Our bound always exceeds the inverse spectral radius of the graph's adjacency matrix, and it is also generally tighter than the existing bound in terms of the maximum degree. We give a constructive proof for existence of such an eigenvalue in the case of a connected infinite quasitransitive graph, a graph-theoretic analog of a translationally invariant system.

Hamilton, Kathleen E.; Pryadko, Leonid P.

2014-11-01

389

A Guide to Running a Recycling Project. [Includes Recycling Handbook].  

ERIC Educational Resources Information Center

This guide, designed for both students and adults, is intended for individuals who feel they might be interested in establishing a recycling depot. The guide includes such pertinent information as deciding how to set up a depot, markets and transportation, preparation of materials, where to place the depot and when to operate it, publicity and

Oregon Recycling Information and Organizing Network, Portland.

390

The Recycling Solution: How I Increased Recycling on Dilworth Road  

ERIC Educational Resources Information Center

The grandson of Fred Keller, one of the founders of behavior analysis, Jacob was 10 years old when he conducted the project for his elementary school science fair. We recently contacted Jacob to learn more about his project. He told us the inspiration came from a class field trip to the county recycling center, which included seeing video footage

Keller, J. Jacob

2010-01-01

391

Automobile Recycling Policy: Findings and Recommendations  

E-print Network

This report focuses on recycling. As an objective neutral party, MIT has compiled a knowledge base that examines the many complex issues relating to re-cycling. Although this report was prepared at the request of the ...

Field, Frank

392

Food Service Recycling: Whose Responsibility Is It?  

ERIC Educational Resources Information Center

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)

Settanni, Barbara

1990-01-01

393

Compositional evaluation of asphalt binder recycling agents  

E-print Network

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...

Madrid, Richard Charles

1997-01-01

394

Ammonia transformations and abundance of ammonia oxidizers in a clay soil underlying a manure pond.  

PubMed

Unlined manure ponds are constructed on clay soil worldwide to manage farm waste. Seepage of ammonia-rich liquor into underlying soil layers contributes to groundwater contamination by nitrate. To identify the possible processes that lead to the production of nitrate from ammonia in this oxygen-limited environment, we studied the diversity and abundance of ammonia-transforming microorganisms under an unlined manure pond. The numbers of ammonia-oxidizing bacteria and anammox bacteria were most abundant in the top of the soil profile and decreased significantly with depth (0.5 m), correlating with soil pore-water ammonia concentrations and soil ammonia concentrations, respectively. On the other hand, the numbers of ammonia-oxidizing archaea were relatively constant throughout the soil profile (10(7) amoA copies per g(soil)). Nitrite-oxidizing bacteria were detected mainly in the top 0.2 m. The results suggest that nitrate accumulation in the vadose zone under the manure pond could be the result of complete aerobic nitrification (ammonia oxidation to nitrate) and could exist as a byproduct of anammox activity. While the majority of the nitrogen was removed within the 0.5-m soil section, possibly by combined anammox and heterotrophic denitrification, a fraction of the produced nitrate leached into the groundwater. PMID:22385337

Sher, Yonatan; Baram, Shahar; Dahan, Ofer; Ronen, Zeev; Nejidat, Ali

2012-07-01

395

Economic and ecological costs and benefits of streamflow augmentation using recycled water in a California coastal stream.  

PubMed

Streamflow augmentation has the potential to become an important application of recycled water in water scarce areas. We assessed the economic and ecological merits of a recycled water project that opted for an inland release of tertiary-treated recycled water in a small stream and wetland compared to an ocean outfall discharge. Costs for the status-quo scenario of discharging secondary-treated effluent to the ocean were compared to those of the implemented scenario of inland streamflow augmentation using recycled water. The benefits of the inland-discharge scenario were greater than the increase in associated costs by US$1.8M, with recreational value and scenic amenity generating the greatest value. We also compared physical habitat quality, water quality, and benthic macroinvertebrate community upstream and downstream of the recycled water discharge to estimate the effect of streamflow augmentation on the ecosystem. The physical-habitat quality was higher downstream of the discharge, although streamflow came in unnatural diurnal pulses. Water quality remained relatively unchanged with respect to dissolved oxygen, pH, and ammonia-nitrogen, although temperatures were elevated. Benthic macroinvertebrates were present in higher abundances, although the diversity was relatively low. A federally listed species, the California red-legged frog (Rana draytonii), was present. Our results may support decision-making for wastewater treatment alternatives and recycled water applications in Mediterranean climates. PMID:23688175

Halaburka, Brian J; Lawrence, Justin E; Bischel, Heather N; Hsiao, Janet; Plumlee, Megan H; Resh, Vincent H; Luthy, Richard G

2013-10-01

396

Multi-component removal in flue gas by aqua ammonia  

DOEpatents

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.

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

2007-08-14

397

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

E-print Network

for Consumer Psychology. Published by Elsevier Inc. All rights reserved. Keywords: Sustainability; RecyclingResearch 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

Loudon, Catherine

398

What Makes a Recycler?A Comparison of Recyclers and Nonrecyclers  

Microsoft Academic Search

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

Joanne Vining; Angela Ebreo

1990-01-01

399

Inhibition of biohydrogen production by ammonia.  

PubMed

Ammonia inhibition of biohydrogen production was investigated in batch and continuous flow reactors with glucose as a substrate. In batch tests, biohydrogen production rate was highly dependent on pH and ammonia (defined as the sum of NH3 of NH4+ species) concentrations above 2 g N/L. At pH = 6.2, the maximum production decreased from 56 mL/h at 2 g N/L to 16 mL/h at 10 g N/L. At pH = 5.2, production decreased from 49 mL/h (2g N/L) to 7 mL/h (16 g N/L). Hydrogen yield remained relatively constant in batch tests, varying from 0.96 to 1.17 mol-H2/mol-glucose. In continuous flow tests, both hydrogen production rates and yields were adversely affected by ammonia. When the reactor (2.0 L) was first acclimated under batch conditions to a low nitrogen concentration (<0.8 g N/L), H2 production and yields under continuous flow mode conditions were 170 mL/h and 1.9 mol-H2/mol-glucose, but decreased with increased ammonia concentrations up to 7.8 g N/L to 105 mL/h and 1.1 mol-H2/mol-glucose. There was no hydrogen production under continuous flow conditions if the reactor was initially operated under batch flow conditions at ammonia concentrations above 0.8 g N/L. It is concluded that the hydrogen production is possible at high concentrations (up to 7.8 g N/L) of ammonia in continuous flow systems as long as the reactor is initially acclimated to a lower ammonia concentration (<0.8 g N/L). PMID:16513155

Salerno, Michael B; Park, Wooshin; Zuo, Yi; Logan, Bruce E

2006-03-01

400

Carbon materials with quasi-graphene layers: The dielectric, percolation properties and the electronic transport mechanism  

NASA Astrophysics Data System (ADS)

We investigate the dielectric properties of multi-walled carbon nanotubes (MWCNTs) and graphite filling in SiO2 with the filling concentration of 2-20 wt.% in the frequency range of 102-107 Hz. MWCNTs and graphite have general electrical properties and percolation phenomena owing to their quasi-structure made up of graphene layers. Both permittivity ? and conductivity ? exhibit jumps around the percolation threshold. Variations of dielectric properties of the composites are in agreement with the percolation theory. All the percolation phenomena are determined by hopping and migrating electrons, which are attributed to the special electronic transport mechanism of the fillers in the composites. However, the twin-percolation phenomenon exists when the concentration of MWCNTs is between 5-10 wt.% and 15-20 wt.% in the MWCNTs/SiO2 composites, while in the graphite/SiO2 composites, there is only one percolation phenomenon in the graphite concentration of 10-15 wt.%. The unique twin-percolation phenomenon of MWCNTs/SiO2 is described and attributed to the electronic transfer mechanism, especially the network effect of MWCNTs in the composites. The network formation plays an essential role in determining the second percolation threshold of MWCNTs/SiO2.

Lu, Ming-Ming; Yuan, Jie; Wen, Bo; Liu, Jia; Cao, Wen-Qiang; Cao, Mao-Sheng

2013-03-01

401

Higher connectivity in random mixtures = the universality class of 2-cluster percolation  

Microsoft Academic Search

Higher connectivity percolation (site valence >= 2) is considered for selected 2, 3, 4-dimensional lattices, by the method of exact series expansions. The set of critical exponents obtained from the perimeter-to-size ratio and the moments of the cluster size distribution favours the same universality class as for normal percolation. The animal statistics are found to be unaffected by the connectivity

J. A. M. S. Duarte; H. J. Ruskin

1982-01-01

402

REVIEW OF PERCOLATION THEORY FOR FLOW IN POROUS MEDIA (LECTURE NOTES IN PHYSICS 674)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Percolation theory is a mathematical model that has been used in the past by physicists to study a variety of physical processes such as fluid flow and electrical conduction. In this short note, we favorably review a new book describing the use of percolation theory for modeling the flow of fluids ...

403

Ordering near the percolation threshold in models of two-dimensional interacting bosons with quenched dilution  

Microsoft Academic Search

Randomly diluted quantum boson and spin models in two dimensions combine the physics of classical percolation with the well-known dimensionality dependence of ordering in quantum lattice models. This combination is rather subtle for models that order in two dimensions but have no true order in one dimension, as the percolation cluster near threshold is a fractal of dimension between 1

N. Bray-Ali; J. E. Moore; T. Senthil; A. Vishwanath

2006-01-01

404

Predicting Saturated Hydraulic Conductivity from Percolation Test Results in Layered Silt Loam Soils  

Technology Transfer Automated Retrieval System (TEKTRAN)

The size of on-site waste disposal systems is usually determined by one or more percolation tests performed on the proposed site. The objectives of this study were to develop an empirical relationship between the saturated hydraulic conductivity (Ks) of layered soils and their percolation times (PT)...

405

Roughness of Brittle Fractures as a Correlated Percolation Problem Jan ystein H. Bakke1  

E-print Network

Roughness of Brittle Fractures as a Correlated Percolation Problem Jan ?ystein H. Bakke1 , Johannes percolation theory. The fracture of brittle materials is a phenomenon that has received much attention, over the last few years, the approach to brittle fracture that has emerged from this community has

Schmittbuhl, Jean

406

Domain Wall Pinning and Corresponding Energy Barrier in Percolated Perpendicular Medium  

Microsoft Academic Search

The domain wall pinning processes in a percolated perpendicular medium are studied using micromagnetic modeling. With a given nonmagnetic pinning site, the energy barrier of the pinned domain wall reaches a maximum when the domain wall width is about twice the size of the pinning site. For transitions in the percolated perpendicular medium, the energy barrier for the transition shift

Yuhui Tang; Jian-Gang Zhu

2007-01-01

407

Poly(N-vinyl-2-pyrrolidone)-stabilized palladium-platinum nanoparticles-catalyzed hydrolysis of ammonia borane for hydrogen generation  

NASA Astrophysics Data System (ADS)

The catalytic use of highly efficient poly(N-vinyl-2-pyrrolidone)-stabilized palladium-platinum nanoparticles (4.2牨1.9爊m) in the hydrolysis of ammonia-borane is reported. The catalyst is prepared by co-reduction of two metal ions in ethanol/water mixture by an alcohol reduction method and characterized by transmission electron microscopy, X-ray photoelectron spectroscopy and UV-Vis spectroscopy. They are recyclable and highly active for hydrogen generation from the hydrolysis of ammonia-borane even at very low concentrations and temperature, providing a record numbers of average turnover frequency value (125爉ol H2/mol燾at.min-1) and maximum hydrogen generation rate (3468燣 H2 min-1 (mol燾at)-1). They also provide activation energy of 51.7牨2爇J/mol for the hydrolysis of ammonia borane.

Rakap, Murat

2015-02-01

408

Recyclization reactions leading to benzimidazoles  

NASA Astrophysics Data System (ADS)

The published data on the recyclization reactions that afford benzimidazoles are generalized and systematized. Both classical and new methods of benzimidazole synthesis are considered. Attention is focused on the publications over the recent 10-15 years; of the earlier publications, only those unknown to the wide circle of chemists are analyzed.

Mamedov, Vakhid A.; Murtazina, Anna M.

2011-05-01

409

Issues in recycling galvanized scrap  

Microsoft Academic Search

The quality of the steel used for most galvanizing (and tinplate) applications makes scrap derived from their production and use a premier solid charge material for steelmaking. In 1989 the AISI created a Task Force to define the issues and to recommend technologically and economically sound approaches to assure continued, unhindered recyclability of the growing volume of galvanized scrap. The

P. J. Koros; D. A. Hellickson; F. J. Dudek

1995-01-01

410

Chemical recycling of scrap composites  

NASA Technical Reports Server (NTRS)

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.

Allred, Ronald E.; Salas, Richard M.

1994-01-01

411

Recycled Water Poses Disinfectant Problem  

ERIC Educational Resources Information Center

Discusses the possible health hazards resulting from released nucleic acid of inactivated viruses, chlorinated nonliving organic molecules, and overestimated reliability of waste treatment standards. Suggests the recycle system use a dual disinfectant such as chlorine and ozone in water treatment. (CC)

Chemical and Engineering News, 1973

1973-01-01

412

NATURAL SURFACTANTS IN PAPER RECYCLING  

EPA Science Inventory

The objective of this project is to introduce new types of surfactants based on renewable materials (sugar surfactants) for use in ink removal from recycled paper. By applying green chemistry approaches we not only will solve an important industry and environmental problem but...

413

WASTE MINIMISATION AND RECYCLING POLICY 1.Introduction  

E-print Network

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 will develop the existing Environmental Policy by minimising the production of waste through good purchasing

Mottram, Nigel

414

Textile Recycling, Convenience, and the Older Adult.  

ERIC Educational Resources Information Center

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

Domina, Tanya; Koch, Kathryn

2001-01-01

415

Really Recycled-SeaWorld Classroom Activity  

NSDL National Science Digital Library

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.

Sea World - Just for Teachers

2012-04-03

416

Sustainability issues in circuit board recycling  

Microsoft Academic Search

The resource recovery and environmental impact issues of printed circuit board recycling by secondary copper smelters are discussed. Guidelines concerning material selection for circuit board manufacture and concerning the recycling processes are given to enhance recovery efficiency and to lower the impacts on the external environment from recycling

Jens Brnbech Legarth; Leo Alting; Gian Luca Baldo

1995-01-01

417

RECYCLING PROGRAM TYPE LOCATION ALLOWED NOT ALLOWED  

E-print Network

RECYCLING PROGRAM TYPE LOCATION ALLOWED NOT ALLOWED Batteries, toner, ink cartridges & cell phones Aerosol cans Window glass The University of Miami strives to create a more sustainable campus environment and recycling is an important part of that effort. Below is a guide to on-campus recycling at RSMAS: Visit http

Miami, University of

418

The Environment Team to Waste & Recycling  

E-print Network

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 with any changes to the recycling scheme, visit it at www.le.ac.uk/environment Many thanks, The Environment

St Andrews, University of

419

ENVIRONMENTAL PROTECTION FOR THE AUTOMOBILE RECYCLING INDUSTRY  

E-print Network

Pollution Abatement Office. Funds were also provided by BC Auto Recyclers, the BC Ministry of Environment of Practice for the Auto Recyclers. The reports have been subjected to Environment Canada and MOELP's peer-CAR). British Columbia Auto Recyclers and El-Rayes Environmental Corporation would like to thank Environment

420

78 FR 69531 - America Recycles Day, 2013  

Federal Register 2010, 2011, 2012, 2013, 2014

...face new threats--to our environment, our health, and our climate...damage our health and harm our environment if not recycled properly. Recycling not only reduces pollution...schools, let us strive to make recycling a part of our daily...

2013-11-19

421

Ames Lab 101: Rare-Earth Recycling  

ScienceCinema

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.

Ryan Ott

2013-06-05

422

Ames Lab 101: Rare-Earth Recycling  

SciTech Connect

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.

Ryan Ott

2012-09-05

423

The Hang-Ups on Recycling  

ERIC Educational Resources Information Center

While all seem to agree that recycling will alleviate solid waste problems and energy and mineral shortages, recycling is, at present, bogged down by the thin market for recycled materials, the recessionary business picture, the vertical integration of many companies, unfavorable tax laws, and high rail freight rates. (BT)

Environmental Science and Technology, 1975

1975-01-01

424

Recycling at Mooov-In 2011  

E-print Network

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

Julien, Christine

425

Superconducting properties in granular aluminum films near percolation threshold  

NASA Astrophysics Data System (ADS)

We have measured the perpendicular upper critical magnetic field HC2, the excess conductance ?? due to superconducting fluctuations and the superconducting transition temperature TC in granular aluminum films in the wide range of the sheet resistance R?, 100 ? ?R ? ?15 k ?. The temperature dependence of HC2 near TC has been analyzed in the form H C2=H C201-T/T Cn. For relatively low resistance films, the index n is almost unit. However, n decreases steeply at a characteristic resistance R *?1.5 k? and approaches 0.7 with increase of R?. This value of n agrees with that predicted from the percolation theory taking account of the fractal nature of clusters. With increasing R? beyond R*, the value of ?? decreases drastically as compared with that estimated from the sum of Aslamazov-Larkin and Maki-Thompson terms. The sheet resistance dependence of ?? can be explained qualitatively by a model based on the scaling law of percolation. The value of TC decreases gradually.

Yamada, Kazumasa; Fujiki, Hiroyuki; Shinozaki, Bunjyu; Kawaguti, Takasi

2001-06-01

426

Localization phase diagram of two-dimensional quantum percolation  

NASA Astrophysics Data System (ADS)

We examine quantum percolation on a square lattice with random dilution up to q = 38% and energy 0.001 ? E ? 1.6 (measured in units of the hopping matrix element), using numerical calculations of the transmission coefficient at a much larger scale than previously. Our results confirm the previous finding that the two dimensional quantum percolation model exhibits localization-delocalization transitions, where the localized region splits into an exponentially localized region and a power-law localization region. We determine a fuller phase diagram confirming all three regions for energies as low as E = 0.1, and the delocalized and exponentially localized regions for energies down to E = 0.001. We also examine the scaling behavior of the residual transmission coefficient in the delocalized region, the power law exponent in the power-law localized region, and the localization length in the exponentially localized region. Our results suggest that the residual transmission at the delocalized to power-law localized phase boundary may be discontinuous, and that the localization length is likely not to diverge with a power-law at the exponentially localized to power-law localized phase boundary. However, further work is needed to definitively assess the characters of the two phase transitions as well as the nature of the intermediate power-law regime.

Dillon, Brianna S.; Nakanishi, Hisao

2014-12-01

427

Percolation and permeability of fracture networks in excavated damaged zones.  

PubMed

Generally, the excavation process of a gallery generates fractures in its immediate vicinity. The corresponding zone which is called the excavated damaged zone (EDZ), has a larger permeability than the intact surrounding medium. Therefore, some of its properties are of crucial importance for applications such as the storage of nuclear wastes. Field observations suggest that the fracture density is an exponentially decreasing function of the distance to the wall and that the fracture orientation is anisotropic and well approximated by a Fisher law whose pole is orthogonal to the wall. Numerical samples are generated according to these prescriptions and their percolation status and hydraulic transmissivity are systematically determined for a wide range of decay lengths and anisotropy parameters. All the numerical data are presented and discussed. A heuristic analytical expression for the percolation threshold is proposed which unifies and accurately represents all the numerical data. A simple parallel flow model yields an explicit analytical expression for the transmissivity as a function of the density, heterogeneity, and anisotropy parameters; the model also successfully accounts for all the numerical data. PMID:23005859

Mourzenko, V V; Thovert, J-F; Adler, P M

2012-08-01

428

Percolation and permeability of fracture networks in excavated damaged zones  

NASA Astrophysics Data System (ADS)

Generally, the excavation process of a gallery generates fractures in its immediate vicinity. The corresponding zone which is called the excavated damaged zone (EDZ), has a larger permeability than the intact surrounding medium. Therefore, some of its properties are of crucial importance for applications such as the storage of nuclear wastes. Field observations suggest that the fracture density is an exponentially decreasing function of the distance to the wall and that the fracture orientation is anisotropic and well approximated by a Fisher law whose pole is orthogonal to the wall. Numerical samples are generated according to these prescriptions and their percolation status and hydraulic transmissivity are systematically determined for a wide range of decay lengths and anisotropy parameters. All the numerical data are presented and discussed. A heuristic analytical expression for the percolation threshold is proposed which unifies and accurately represents all the numerical data. A simple parallel flow model yields an explicit analytical expression for the transmissivity as a function of the density, heterogeneity, and anisotropy parameters; the model also successfully accounts for all the numerical data.

Mourzenko, V. V.; Thovert, J.-F.; Adler, P. M.

2012-08-01

429

What percolation theory can tell us about COPD.  

PubMed

Damage to the lung elastic fiber network is largely responsible for the distention and rupture of alveolar walls in chronic obstructive pulmonary disease (COPD). It has therefore been suggested that blood or urine levels of the unique elastic fiber crosslinks, desmosine and isodesmosine (DID), may serve as a biomarker for the progression of the disease. The prognostic value of DID may be limited, however, by the large degree of variance associated with their measurement in patients with COPD. To overcome this problem, we propose that specific patterns of DID release from damaged elastic fibers, rather than their absolute quantity, may provide a better indication of morphological changes in the lungs of patients with COPD. Using percolation theory to model the elastic fiber network in the lung, it will be shown that the relative amounts of damaged and intact elastic fibers may be reflected at the molecular level by urinary levels of free and peptide-bound DID, respectively. The self-similar nature of percolation networks further suggests that detachment of crosslinks from elastic fibers may be analogous to the rupture of alveolar walls in COPD. Consequently, the ratio of free to bound DID may be a measure of emphysematous changes in this disease. PMID:23759356

Cantor, J O; Ma, S; Turino, G M

2013-08-01

430

Percolation Transitions of Random Networks under a Weight Probability Function  

NASA Astrophysics Data System (ADS)

Based on the clusters growth mechanisms, we study a percolation model where the clusters are assigned to a weight probability function and the intracluster edges are excluded. The weight probability function includes a tunable parameter ?. The model can realize the phase transition from continuous to multiple discontinuous and discontinuous as the value of ? is tuned. According to the properties of the weight probability function, three typical cases which correspond to different clusters growth mechanisms are analyzed. When the system size N is equal to 1/?, probability modulation effect indicates that the percolation process generates a continuous phase transition which is similar to the classical Erd鰏桼閚yi (ER) network model. At ? = 1, it is shown that the lower pseudotransition point is converging to 1 in the thermodynamic limit and the cluster size distribution at the lower pseudotransition point does not obey the power-law behavior, indicating a first-order phase transition. For ? = N?1/2, the order parameter exhibits multiple jumps and the magnitude of the jumps are randomly distributed. The numerical simulations find that the relative variance of the order parameter is nonzero on an extended interval. It indicates that the order parameter is non-self-averaging. The cluster size heterogeneity decreases oscillatorily from some moment, which also implies the phenomenon.

Jia, Xiao; Hong, Jin-Song; Yang, Hong-Chun; Yang, Chun; Fu, Chuan-Ji; Hu, Jian-Quan; Shi, Xiao-Hong

2015-01-01

431

The effect of interdependence on the percolation of interdependent networks  

NASA Astrophysics Data System (ADS)

Two stochastic models are proposed to generate a system composed of two interdependent scale-free (SF) or Erd?s-R閚yi (ER) networks where interdependent nodes are connected with an exponential or power-law relation, as well as different dependence strength, respectively. Each subnetwork grows through the addition of new nodes with constant accelerating random attachment in the first model but with preferential attachment in the second model. The two subnetworks interact with multi-support and undirectional dependence links. The effects of dependence relations and strength between subnetworks are analyzed in the percolation behavior of fully interdependent networks against random failure, both theoretically and numerically, and as a result, for both relations: interdependent SF networks show a second-order percolation phase transition and the increased dependence strength decreases the robustness of the system, whereas, interdependent ER networks show the opposite results. In addition, the power-law relation between networks yields greater robustness than the exponential one at the given dependence strength.

Jiang, J.; Li, W.; Cai, X.

2014-09-01

432

Agglomerative percolation on the Bethe lattice and the triangular cactus  

NASA Astrophysics Data System (ADS)

Agglomerative percolation (AP) on the Bethe lattice and the triangular cactus is studied to establish the exact mean-field theory for AP. Using the self-consistent simulation method based on the exact self-consistent equations, the order parameter P? and the average cluster size S are measured. From the measured P? and S, the critical exponents ?k and ?k for k = 2 and 3 are evaluated. Here, ?k and ?k are the critical exponents for P? and S when the growth of clusters spontaneously breaks the Zk symmetry of the k-partite graph. The obtained values are ?2 = 1.79(3), ?2 = 0.88(1), ?3 = 1.35(5) and ?3 = 0.94(2). By comparing these exponents with those for ordinary percolation (?? = 1 and ?? = 1), we also find ?? < ?3 < ?2 and ?? > ?3 > ?2. These results quantitatively verify the conjecture that the AP model belongs to a new universality class if the Zk symmetry is broken spontaneously, and the new universality class depends on k.

Chae, Huiseung; Yook, Soon-Hyung; Kim, Yup

2013-08-01

433

Percolation transition in dynamical traffic network with evolving critical bottlenecks.  

PubMed

A critical phenomenon is an intrinsic feature of traffic dynamics, during which transition between isolated local flows and global flows occurs. However, very little attention has been given to the question of how the local flows in the roads are organized collectively into a global city flow. Here we characterize this organization process of traffic as "traffic percolation," where the giant cluster of local flows disintegrates when the second largest cluster reaches its maximum. We find in real-time data of city road traffic that global traffic is dynamically composed of clusters of local flows, which are connected by bottleneck links. This organization evolves during a day with different bottleneck links appearing in different hours, but similar in the same hours in different days. A small improvement of critical bottleneck roads is found to benefit significantly the global traffic, providing a method to improve city traffic with low cost. Our results may provide insights on the relation between traffic dynamics and percolation, which can be useful for efficient transportation, epidemic control, and emergency evacuation. PMID:25552558

Li, Daqing; Fu, Bowen; Wang, Yunpeng; Lu, Guangquan; Berezin, Yehiel; Stanley, H Eugene; Havlin, Shlomo

2015-01-20

434

USF Physical Plant Recycling Program Updated November 2013  

E-print Network

Recyclables (Bulbs, Tires, etc.) 7 tons #12;Recycle Ratio for FY 2012/2013 路 Total waste generated: 3419 tonsUSF Physical Plant Recycling Program Updated November 2013 #12;Beginnings 路 Program initiated 路 Continuously expanding recycling efforts #12;Paper Recycling 路 Currently recycling mixed paper Office paper

Meyers, Steven D.

435

Materials Recycling: The Virtue of Necessity. Worldwatch Paper 56.  

ERIC Educational Resources Information Center

This report focuses on the necessity and advantages of recycling. Following an introduction, the report is divided into five sections, addressing respectively: the necessity of recycling; waste paper recycling; aluminum recycling; iron and steel recycling; and three steps to a "recycling society." These steps include: (1) requiring that consumers

Chandler, William U.

436

Environmental and economic assessment of a cracked ammonia fuelled alkaline fuel cell for off-grid power applications  

NASA Astrophysics Data System (ADS)

Global mobile telecommunication is possible due to millions of Base Transceiver Stations (BTS). Nearly 1 million of these are operating off-grid, typically powered by diesel generators and therefore leading to significant CO2 emissions and other environmental burdens. A novel type of Alkaline Fuel Cell (AFC) powered by cracked ammonia is being developed for replacement of these generators. This study compares the environmental and economic performance of the two systems by means of Life Cycle Assessment (LCA) and Levelised Cost of Electricity (LCOE), respectively. Results show that the production of ammonia dominates the LCA results, and that renewable ammonia production pathways greatly improve environmental performance. Sensitivity analyses reveal that the fuel cell parameters that most affect system cost and environmental burdens are cell power density and lifetime and system efficiency. Recycling of anode catalyst and electrode substrate materials is found to have large impacts on environmental performance, though without large cost incentives. For a set of target parameter values and fossil sourced ammonia, the AFC is calculated to produce electricity with life cycle CO2 eq emissions of 1.08爇g爇Wh-1, which is 23% lower than a diesel generator with electricity costs that are 14% higher in the same application.

Cox, Brian; Treyer, Karin

2015-02-01

437

The Ammonia?Hydrogen System under Pressure  

SciTech Connect

Binary mixtures of hydrogen and ammonia were compressed in diamond anvil cells to 15 GPa at room temperature over a range of compositions. The phase behavior was characterized using optical microscopy, Raman spectroscopy, and synchrotron X-ray diffraction. Below 1.2 GPa we observed two-phase coexistence between liquid ammonia and fluid hydrogen phases with limited solubility of hydrogen within the ammonia-rich phase. Complete immiscibility was observed subsequent to the freezing of ammonia phase III at 1.2 GPa, although hydrogen may become metastably trapped within the disordered face-centered-cubic lattice upon rapid solidification. For all compositions studied, the phase III to phase IV transition of ammonia occurred at {approx}3.8 GPa and hydrogen solidified at {approx}5.5 GPa, transition pressures equivalent to those observed for the pure components. A P-x phase diagram for the NH{sub 3}-H{sub 2} system is proposed on the basis of these observations with implications for planetary ices, molecular compound formation, and possible hydrogen storage materials.

Chidester, Bethany A.; Strobel, Timothy A. (CIW)

2012-01-20

438

Energy Efficient Operation of Ammonia Refrigeration Systems  

SciTech Connect

Ammonia refrigeration systems typically offer many energy efficiency opportunities because of their size and complexity. This paper develops a model for simulating single-stage ammonia refrigeration systems, describes common energy saving opportunities, and uses the model to quantify those opportunities. The simulation model uses data that are typically available during site visits to ammonia refrigeration plants and can be calibrated to actual consumption and performance data if available. Annual electricity consumption for a base-case ammonia refrigeration system is simulated. The model is then used to quantify energy savings for six specific energy efficiency opportunities; reduce refrigeration load, increase suction pressure, employ dual suction, decrease minimum head pressure set-point, increase evaporative condenser capacity, and reclaim heat. Methods and considerations for achieving each saving opportunity are discussed. The model captures synergistic effects that result when more than one component or parameter is changed. This methodology represents an effective method to model and quantify common energy saving opportunities in ammonia refrigeration systems. The results indicate the range of savings that might be expected from common energy efficiency opportunities.

Mohammed, Abdul Qayyum [University of Dayton, Ohio] [University of Dayton, Ohio; Wenning, Thomas J [ORNL] [ORNL; Sever, Franc [University of Dayton, Ohio] [University of Dayton, Ohio; Kissock, Professor Kelly [University of Dayton, Ohio] [University of Dayton, Ohio

2013-01-01

439

Void percolation and conduction of overlapping ellipsoids Department of Engineering, University of Denver, Denver, Colorodo 80208, USA  

E-print Network

Void percolation and conduction of overlapping ellipsoids Y. B. Yi Department of Engineering 2006; published 13 September 2006 The void percolation and conduction problems for equisized in literature. The technique is then extended to determine the threshold of void percolation as a function

Yi, Yun-Bo

440

Ammonia-oxidizing archaea have more important role than ammonia-oxidizing bacteria in ammonia oxidation of strongly acidic soils.  

PubMed

Increasing evidence demonstrated the involvement of ammonia-oxidizing archaea (AOA) in the global nitrogen cycle, but the relative contributions of AOA and ammonia-oxidizing bacteria (AOB) to ammonia oxidation are still in debate. Previous studies suggest that AOA would be more adapted to ammonia-limited oligotrophic conditions, which seems to be favored by protonation of ammonia, turning into ammonium in low-pH environments. Here, we investigated the autotrophic nitrification activity of AOA and AOB in five strongly acidic soils (pH<4.50) during microcosm incubation for 30 days. Significantly positive correlations between nitrate concentration and amoA gene abundance of AOA, but not of AOB, were observed during the active nitrification. (13)CO(2)-DNA-stable isotope probing results showed significant assimilation of (13)C-labeled carbon source into the amoA gene of AOA, but not of AOB, in one of the selected soil samples. High levels of thaumarchaeal amoA gene abundance were observed during the active nitrification, coupled with increasing intensity of two denaturing gradient gel electrophoresis bands for specific thaumarchaeal community. Addition of the nitrification inhibitor dicyandiamide (DCD) completely inhibited the nitrification activity and CO(2) fixation by AOA, accompanied by decreasing thaumarchaeal amoA gene abundance. Bacterial amoA gene abundance decreased in all microcosms irrespective of DCD addition, and mostly showed no correlation with nitrate concentrations. Phylogenetic analysis of thaumarchaeal amoA gene and 16S rRNA gene revealed active (13)CO(2)-labeled AOA belonged to groups 1.1a-associated and 1.1b. Taken together, these results provided strong evidence that AOA have a more important role than AOB in autotrophic ammonia oxidation in strongly acidic soils. PMID:22134644

Zhang, Li-Mei; Hu, Hang-Wei; Shen, Ju-Pei; He, Ji-Zheng

2012-05-01

441

Recycling Trends in the Plastics Manufacturing and Recycling Companies in Malaysia  

NASA Astrophysics Data System (ADS)

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.

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

442

The reaction of monochloramine and hydroxylamine: implications for ammonia?oxidizing bacteria in chloraminated drinking water  

EPA Science Inventory

Drinking water chloramine use may promote ammonia?oxidizing bacteria (AOB) growth because of naturally occurring ammonia, residual ammonia remaining from chloramine formation, and ammonia released from chloramine decay and demand. A rapid chloramine residual loss is often associa...

443

Effect of gaseous ammonia on nicotine sorption  

SciTech Connect

Nicotine is a major constituent of environmental tobacco smoke. Sorptive interactions of nicotine with indoor surfaces can substantially alter indoor concentrations. The phenomenon is poorly understood, including whether sorption is fully reversible or partially irreversible. They hypothesize that acid-base chemistry on indoor surfaces might contribute to the apparent irreversibility of nicotine sorption under some circumstances. Specifically, they suggest that nicotine may become protonated on surfaces, markedly reducing its vapor pressure. If so, subsequent exposure of the surface to gaseous ammonia, a common base, could raise the surface pH, causing deprotonation and desorption of nicotine from surfaces. A series of experiments was conducted to explore the effect of ammonia on nicotine sorption to and reemission from surfaces. The results indicate that, under some conditions, exposure to gaseous ammonia can substantially increase the rate of desorption of previously sorbed nicotine from common indoor surface materials.

Webb, A.M.; Singer, B.C.; Nazaroff, W.W.

2002-06-01

444

ParadigmParadigm Concrete RecyclingConcrete Recycling  

E-print Network

路路 Whatever steel goes into PCC must comeWhatever steel goes into PCC must come out for recycleout for recycle.2. Open Graded BaseOpen Graded Base 3.3. Cement Treated BaseCement Treated Base 4.4. ConcreteConcrete 5-1/2" 100 100 1" 100 100 1/2" 25 60 No. 4 0 10 No. 8 0 5 No. 200 0 2 #12;#12;#12;#12;#12;#12;3. Cement

445

Cost effectiveness of recycling: A systems model  

SciTech Connect

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.

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

446

Comparison of recycling outcomes in three types of recycling collection units.  

PubMed

Commercial institutions have many factors to consider when implementing an effective recycling program. This study examined the effectiveness of three different types of recycling bins on recycling accuracy by determining the percent weight of recyclable material placed in the recycling bins, comparing the percent weight of recyclable material by type of container used, and examining whether a change in signage increased recycling accuracy. Data were collected over 6 weeks totaling 30 days from 3 different recycling bin types at a Midwest University medical center. Five bin locations for each bin type were used. Bags from these bins were collected, sorted into recyclable and non-recyclable material, and weighed. The percent recyclable material was calculated using these weights. Common contaminates found in the bins were napkins and paper towels, plastic food wrapping, plastic bags, and coffee cups. The results showed a significant difference in percent recyclable material between bin types and bin locations. Bin type 2 was found to have one bin location to be statistically different (p=0.048), which may have been due to lack of a trash bin next to the recycling bin in that location. Bin type 3 had significantly lower percent recyclable material (p<0.001), which may have been due to lack of a trash bin next to the recycling bin and increased contamination due to the combination of commingled and paper into one bag. There was no significant change in percent recyclable material in recycling bins post signage change. These results suggest a signage change may not be an effective way, when used alone, to increase recycling compliance and accuracy. This study showed two or three-compartment bins located next to a trash bin may be the best bin type for recycling accuracy. PMID:23063307

Andrews, Ashley; Gregoire, Mary; Rasmussen, Heather; Witowich, Gretchen

2013-03-01

447

High performance polyester concrete using recycled PET  

SciTech Connect

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.

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

1995-10-01

448

Composite material from recycled polyester for recyclable automobile structures  

SciTech Connect

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.

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

1995-12-31

449

Effect of Transient Ammonia Concentrations on PEMFC Performance  

E-print Network

Effect of Transient Ammonia Concentrations on PEMFC Performance Herie J. Soto,a, * Woo-kum Lee operation. Ammonia may be formed in fuel reforming processes at levels up to 150 ppm,2 and because reformate

Van Zee, John W.

450

Biodegradation of bisphenol a and ibuprofen by ammonia oxidizing bacteria  

E-print Network

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...

Subramanya, Nethra T.

2007-09-17

451

Estimating ammonia volatilization and deposition from fertilized vegetation  

NASA Astrophysics Data System (ADS)

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.

Heuer, M. W.; Myles, L.

2010-12-01

452

Ammonia volatilisation in waste stabilisation ponds: a cascade of misinterpretations?  

PubMed

Ammonia volatilisation has generally been reported as, or assumed to be, the main nitrogen removal mechanism in waste stabilisation ponds (WSP). Nitrogen removal via ammonia volatilisation is based on two observations: (a) in-pond pH values can reach high values (>9, even >10), so increasing the proportion of the total ammonia present as the un-ionized form or free ammonia (NH(3)); and (b) in-pond temperatures can also be high, so improving the mass transfer rate of free ammonia to the atmosphere. Consequently, one of the most widely accepted models for ammonia removal in WSP is that reported by Pano & Middlebrooks in 1982, which was developed to reflect the occurrence of these two observations. This work reports how simple mathematical models for ammonia volatilisation in WSP, in spite of the possibility of their giving good predictions, may not accurately describe the main pathways and mechanisms involved in ammonia removal in WSP. PMID:20150690

Camargo Valero, M A; Mara, D D

2010-01-01

453

Ammonia Results Review for Retained Gas Sampling  

SciTech Connect

This report was prepared as part of a task supporting the deployment of the retained gas sampler (RGS) system in Flammable Gas Watch List Tanks. The emphasis of this report is on presenting supplemental information about the ammonia measurements resulting from retained gas sampling of Tanks 241-AW-101, A-101, AN-105, AN-104, AN-103, U-103, S-106, BY-101, BY-109, SX-106, AX-101, S-102, S-111, U-109, and SY-101. This information provides a better understanding of the accuracy of past RGS ammonia measurements, which will assist in determining flammable and toxicological hazards.

Mahoney, Lenna A.

2000-09-20

454

Biochemistry of Ammonia Monoxygenase from Nitrosomonas  

SciTech Connect

Major results. 1. CytochromecM552, a protein in the electron transfer chain to ammonia monooxygenase. Purification, modeling of protein structure based on primary structure, characterization of 4 hemes by magnetic spectroscopy, potentiometry, ligand binding and turnover. Kim, H. J., ,Zatsman, et al. 2008). 2. Characterization of proteins which thought to be involved in the AMO reaction or to protect AMO from toxic nitrogenous intermediates such as NO. Nitrosocyanin is a protein present only in bacteria which catalyze the ammonia monoxygenase reaction (1). Cytochrome c P460 beta and cytochrome c beta.

Alan Hooper

2009-07-15

455

Radiation damage effects in polarized deuterated ammonia  

SciTech Connect

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.

P.M. McKee

2003-07-01

456

Diffusion of ammonia gas in PDMS characterized by ATR spectroscopy  

NASA Astrophysics Data System (ADS)

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.

Levinsk, Petr; Kalvoda, Ladislav; Aubrecht, Jan; Fojt韐ov, Jaroslava

2015-01-01

457

Ammonia Production, Excretion, Toxicity, and Defense in Fish: A Review  

PubMed Central

Many fishes are ammonotelic but some species can detoxify ammonia to glutamine or urea. Certain fish species can accumulate high levels of ammonia in the brain or defense against ammonia toxicity by enhancing the effectiveness of ammonia excretion through active NH4+transport, manipulation of ambient pH, or reduction in ammonia permeability through the branchial and cutaneous epithelia. Recent reports on ammonia toxicity in mammalian brain reveal the importance of permeation of ammonia through the blood朾rain barrier and passages of ammonia and water through transporters in the plasmalemma of brain cells. Additionally, brain ammonia toxicity could be related to the passage of glutamine through the mitochondrial membranes into the mitochondrial matrix. On the other hand, recent reports on ammonia excretion in fish confirm the involvement of Rhesus glycoproteins in the branchial and cutaneous epithelia. Therefore, this review focuses on both the earlier literature and the up-to-date information on the problems and mechanisms concerning the permeation of ammonia, as NH3, NH4+ or proton-neutral nitrogenous compounds, across mitochondrial membranes, the blood朾rain barrier, the plasmalemma of neurons, and the branchial and cutaneous epithelia of fish. It also addresses how certain fishes with high ammonia tolerance defend against ammonia toxicity through the regulation of the permeation of ammonia and related nitrogenous compounds through various types of membranes. It is hoped that this review would revive the interests in investigations on the passage of ammonia through the mitochondrial membranes and the blood朾rain barrier of ammonotelic fishes and fishes with high brain ammonia tolerance, respectively. PMID:21423375

Ip, Yuen K.; Chew, Shit F.

2010-01-01

458

DWPF recycle minimization: Brainstorming session  

SciTech Connect

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.

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

1993-10-12

459

Vanadium recycling for fusion reactors  

SciTech Connect

Very stringent purity specifications must be applied to low activation vanadium alloys, in order to meet recycling goals requiring low residual dose rates after 50--100 years. Methods of vanadium production and purification which might meet these limits are described. Following a suitable cooling period after their use, the vanadium alloy components can be melted in a controlled atmosphere to remove volatile radioisotopes. The aim of the melting and decontamination process will be the achievement of dose rates low enough for ``hands-on`` refabrication of new reactor components from the reclaimed metal. The processes required to permit hands-on recycling appear to be technically feasible, and demonstration experiments are recommended. Background information relevant to the use of vanadium alloys in fusion reactors, including health hazards, resources, and economics, is provided.

Dolan, T.J.; Butterworth, G.J.

1994-04-01

460

Eclogitic diamond formation at jwaneng: No room for a recycled component  

PubMed

Eclogitic diamonds have a large range of delta13C values, whereas peridotitic diamonds do not. Paired delta15N-delta13C-N variations in 40 eclogitic diamonds from the Jwaneng kimberlite in Botswana show that neither the influence of recycled biogenic carbon nor the global and primordial heterogeneity of mantle carbon are likely for the origin of the large delta13C range; the data instead support a fractionation process. It is proposed that carbonatitic mantle melts from which diamonds crystallize undergo different evolutions before diamond precipitation, when percolating through either a peridotite or an eclogite. These different evolutions, reflecting the presence or absence of olivine, can account for their respective delta13C distributions. PMID:9603728

Cartigny; Harris; Javoy

1998-05-29

461

DWPF recycle stream corrosion tests  

Microsoft Academic Search

Coupon immersion tests were performed on ASTM A537 Class 1 carbon steel in simulated DWPF recycle solutions at 90 [+-] 2[degrees]C, as part of the continuing effort to investigate the formation of shock-sensitive deposits. Coupons were partially immersed for four months in solutions of the same composition used previously at SRTC and at the DuPont Engineering Test Center (a salt

Zapp

1993-01-01

462

DWPF recycle stream corrosion tests  

Microsoft Academic Search

Coupon immersion tests were performed on ASTM A537 Class 1 carbon steel in simulated DWPF recycle solutions at 90 {+-} 2掳C, as part of the continuing effort to investigate the formation of shock-sensitive deposits. Coupons were partially immersed for four months in solutions of the same composition used previously at SRTC and at the DuPont Engineering Test Center (a salt

Zapp

1993-01-01

463

Slag recycling of irradiated vanadium  

SciTech Connect

An experimental inductoslag apparatus to recycle irradiated vanadium was fabricated and tested. An experimental electroslag apparatus was also used to test possible slags. The testing was carried out with slag materials that were fabricated along with impurity bearing vanadium samples. Results obtained include computer simulated thermochemical calculations and experimentally determined removal efficiencies of the transmutation impurities. Analyses of the samples before and after testing were carried out to determine if the slag did indeed remove the transmutation impurities from the irradiated vanadium.

Gorman, P.K.

1995-04-05

464

Ozone bleaching of recycled paper  

SciTech Connect

Chlorinated bleaching chemicals, notably chlorine and hypochlorite, are still being used to bleach deinked, woodfree pulps. Increasing environmental concern about the use of these chemicals--coupled with the industry's efforts to increase the use of recycled fibers--highlight the need to develop better techniques for producing high-quality deinked pulp. Results presented in this report suggest that deinked fibers can be treated with ozone followed by a peroxide bleaching stage to produce a high-quality pulp.

Muguet, M.; Kogan, J. (American Air Liquide, Countryside, IL (United States))

1993-11-01

465

Percolation and permeability of fracture networks in Excavated Damaged Zones  

NASA Astrophysics Data System (ADS)

Generally, the excavation process of a gallery generates fractures in its immediate vicinity. The corresponding zone which is called the Excavated Damaged Zone (EDZ), has a larger permeability than the intact surrounding medium. The properties of the EDZ are attracting more and more attention because of their potential importance in repositories of nuclear wastes. The EDZ which is induced by the excavation process may create along the galleries of the repositories a high permeability zone which could directly connect the storage area with the ground surface. Therefore, the studies of its properties are of crucial importance for applications such as the storage of nuclear wastes. Field observations (such as the ones which have been systematically performed at Mont Terri by [1, 2]) suggest that the fracture density is an exponentially decreasing function of the distance to the wall with a characteristic length of about 0.5 m and that the fracture orientation is anisotropic (most fractures are subparallel to the tunnel walls) and well approximated by a Fisher law whose pole is orthogonal to the wall. Numerical samples are generated according to these prescriptions. Their percolation status and hydraulic transmissivity can be calculated by the numerical codes which are detailed in [3]. Percolation is determined by a pseudo diffusion algorithm. Flow determination necessitates the meshing of the fracture networks and the discretisation of the Darcy equation by a finite volume technique; the resulting linear system is solved by a conjugate gradient algorithm. Only the flow properties of the EDZ along the directions which are parallel to the wall are of interest when a pressure gradient parallel to the wall is applied. The transmissivity T which relates the total flow rate per unit width Q along the wall through the whole EDZ to the pressure gradient grad p, is defined by Q = - T grad p/mu where mu is the fluid viscosity. The percolation status and hydraulic transmissivity are systematically determined for a wide range of decay lengths and anisotropy parameters. They can be modeled by comparison with anisotropic fracture networks with a constant density. A heuristic power-law model is proposed which accurately describes the results for the percolation threshold over the whole investigated range of heterogeneity and anisotropy. Then, the data for the EDZ transmissivity are presented. A simple parallel flow model is introduced. The flow properties of the EDZ vary with the distance z from the wall. However, the macroscopic pressure gradient does not depend on z, and the flow lines are in average parallel to the wall. Hence, the overall transmissivity is tentatively estimated by a parallel flow model, where a layer at depth z behaves as a fractured medium with uniform properties corresponding to the state at this position in the EDZ. It yields an explicit analytical expression for the transmissivity as a function of the heterogeneity and anisotropy parameters, and it successfully accounts for all the numerical data. Graphical tools are provided from which first estimates can be quickly and easily obtained. [1] Bossart P. et al, Eng. Geol., vol. 66, 19-38 (2002). [2] Thovert J.-F. et al, Eng. Geol., 117, 39-51 (2011). [3] Adler P.M. et al, Fractured porous media, Oxford U. Press, in press.

Mourzenko, V.; Thovert, J.; Adler, P. M.

2012-12-01

466

Fluid Percolation Within AN Ocean-Continent Transition  

NASA Astrophysics Data System (ADS)

Divergent plate boundaries, such as ocean-continent transitions (OCT) are the perfect target to study mechanisms activated during extension leading to localisation of deformation. The Platta-Totalp massifs in the Eastern Central Alps (Grison, Switzerland) represent a type example of a zone of exhumed continental mantle and offer a complete stratigraphic sequence of an OCT. A detailed study of the geochemistry and microstructures is undertaken to characterise the deformation in such setting. The mantle rocks are spinel lherzolites and harzburgites, into which gabbros and basaltic dykes were intruded, and are partially covered by ophicarbonates. Previous work across the Platta reveals that mantle rocks close to the continent may represent spinel peridotite mixed with (garnet)-pyroxenite layers while the ultramafic rocks at some distance from the continent are pyroxenite-poor peridotites that equilibrated in the plagioclase stability field (Muntener et al. 2004). Fieldwork across the mantle sequence shows localization of deformation with metric or centimetric shear-zones. Peridotites in shear-zones close to the continent have an ultra-mylonitic texture, and contain amphibole testifying fluid percolation. In a centimetric shear-zone amphibole is observed within a matrix made up of a mixture of pyroxenes, olivine, amphibole and spinel with a grain size from 1 to 8 ?m, and as round grains (grain size from 30 to 50?m) embedded in the fine-grained matrix. The host peridotite, which is also deformed, contains larger grains of amphibole with a grain size up to 400 ?m. The chemical composition of the amphibole changes from large to small grains, increasing in K2O and decreasing in TiO2 (wt%) indicating an evolution of the percolating fluid during the localisation of deformation. Another ultra-mylonite (grain size ~ 5?m) from the same mantle sequence displays unmixed areas of clinopyroxene-amphibole and olivine-orthopyroxene, which are folded together. The chemical composition of the amphibole has a lower TiO2 and K2O content than in the other sample. From the continent to the ocean, the clinopyroxene shows a decrease in Na2O for a similar Cr2O3 (wt%) content. However, clinopyroxene compositions indicate a decrease in Al2O3, Na2O, and Cr2O3 (wt%) and homogenisation of the compositions in the fine-grained matrix in the entire sequence suggesting a concordant decrease in temperature. A detailed study of the peridotite textures and geochemistry is combined with analysis of the crystallographic preferred orientation using the EBSD method to determine the deformation mechanisms activated during extension. Mapping of individual porphyroclastic clinopyroxenes and large grains of amphiboles within the host (deformed) peridotite display cumulative misorientation angles up to 35 degrees. Moreover, the patterns of dispersion indicate intra-grain composite deformation leading to a grain size reduction. Our preliminary results indicate fluid percolation and chemical variation during localisation of deformation. This study will constrain the localisation of the deformation related to decreasing temperatures and fluid percolation within extensional setting such as OCT. Ref: Muntener et al. 2004, EPSL, 221, 293-308

Kaczmarek, M.; Reddy, S. M.

2013-12-01

467

Percolation transitions in bilayer graphene encapsulated by hexagonal boron nitride  

NASA Astrophysics Data System (ADS)

We studied the plateau-plateau transitions that characterize the electrical transport in the quantum Hall regime in a high mobility bilayer graphene flake encapsulated by hexagonal boron nitride at magnetic fields up to 9 T and temperatures above 300 mK. We measured independently the exponent ? of the temperature-induced transition broadening, the critical exponent ? of the localization length, and the exponent p ruling the temperature scaling of the coherence length, finding consistency with the relation ? =p /2 ? . The observed value of ? =0.30 (0.28 ,0.32 ) deviates from that of the quantum Hall critical point. The obtained ? =1.25 (0.96 ,1.54 ) questions the validity of a pure Anderson transition, and reveals percolation as the underlying driving mechanism.

Cobaleda, C.; Pezzini, S.; Rodriguez, A.; Diez, E.; Bellani, V.

2014-10-01

468

USE OF ZEOLITE FOR REMOVING AMMONIA AND AMMONIA-CAUSED TOXCITY IN MARINE TOXICITY IDENTIFCATION EVALUATIONS (TIES)  

EPA Science Inventory

Ammonia occurs in marine waters including effluents, receiving waters, and sediment interstitial waters. At sufficiently high concentrations, ammonia can be toxic to aquatic species. Toxicity identification evaluation (TIE) methods provide researchers with tools for identifyi...

469

TOXICITY OF AMMONIA, NITRITE AND NITRATE TO FISHES  

EPA Science Inventory

Ammonia and nitrite are highly toxic to fishes, wig ammonia occurring in urface waters more commonly than nitrite. itrate is a related compound but is not ignificantly toxic to fishes. he acute toxicity of ammonia to aquatic organisms s affected by water pH, dissolved oxygen, tem...

470

AMMONIA LARGE SCALE ATMOSPHERIC DISPERSION EXPERIMENTS IN INDUSTRIAL CONFIGURATIONS  

E-print Network

AMMONIA LARGE SCALE ATMOSPHERIC DISPERSION EXPERIMENTS IN INDUSTRIAL CONFIGURATIONS R茅my 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

Paris-Sud XI, Universit茅 de

471

Borane-Ammonia Complexes Stabilized by Hydrogen Bonding  

E-print Network

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

Trauner, Dirk

472

A Laboratory Intercomparison of Real-Time Gaseous Ammonia  

E-print Network

A Laboratory Intercomparison of Real-Time Gaseous Ammonia Measurement Methods J A M E S J . S C H W, 2007 Six different measurement methods (and seven instruments) for the measurement of gaseous ammonia the LOPAP. Introduction Ammonia (NH3) gas plays a number of important roles in atmospheric chemistry

Pryor, Sara C.

473

AMMONIA THE OTHER HYDROGEN Rebecca Dunn, Keith Lovegrove  

E-print Network

AMMONIA 颅 THE OTHER HYDROGEN Rebecca Dunn, Keith Lovegrove Solar Thermal Group Department This paper reviews many aspects of the use of ammonia as a renewable fuel, including the properties of the fuel itself, and current developments in the field. Most notable among the properties of ammonia

474

Transportable automated ammonia sensor based on a pulsed thermoelectrically cooled  

E-print Network

Transportable automated ammonia sensor based on a pulsed thermoelectrically cooled quantum Gmachl, Federico Capasso, Deborah L. Sivco, and Alfred Y. Cho A compact ammonia sensor based on a 10- m details of the design and performance of a robust, portable ammonia sensor based on a pulsed QC DFB laser

475

MICROBIAL AMMONIA OXIDATION IN DEEP-SEA HYDROTHERMAL PLUMES  

E-print Network

MICROBIAL AMMONIA OXIDATION IN DEEP-SEA HYDROTHERMAL PLUMES A DISSERTATION SUBMITTED;ABSTRACT Autotrophic ammonia oxidation has been documented for the first time in deep- sea hydrothermal autotrophic ammonia oxidation at ~ 91 nM d-1 , and potentially produces de novo organic carbon at a rate (0

Luther, Douglas S.

476

Analysis of Instability in an Industrial Ammonia Reactor  

E-print Network

Analysis of Instability in an Industrial Ammonia Reactor John C. Morud and Sigurd Skogestad Dept point for this study was an incident in an industrial plant, where the ammonia synthesis reactor became of this work was an incident in an indus- trial ammonia fixed-bed synthesis reactor in Germany in 1989. After

Skogestad, Sigurd

477

Passive Ammonia Sensor: RFID Tag Integrating Carbon Nanotubes  

E-print Network

Passive Ammonia Sensor: RFID Tag Integrating Carbon Nanotubes C. Occhiuzzi (1), A.Rida(2), G is highly sensitive to small quantities of ammonia (NH3) and other gaseous [3]. It is not surprising either for the first time as a battery-less wireless ammonia sensor. The physical rationale of the proposed sensor

Tentzeris, Manos

478

Removal of ammonia from tarry water using a tubular furnace  

SciTech Connect

An ammonia-processing system without the use of live steam from OAO Alchevskkoks plant's supply network is considered. Steam obtained from the wastewater that leaves the ammonia column is used to process the excess tarry water, with the release of volatile ammonia.

V.V. Grabko; V.A. Kofanova; V.M. Li; M.A. Solov'ev [Giprokoks, the State Institute for the Design of Coke-Industry Enterprises, Kharkov (Ukraine)

2009-07-15

479

Original article Ammonia treatment of lucerne and cocksfoot  

E-print Network

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

Paris-Sud XI, Universit茅 de

480

Atmospheric Environment 37 (2003) 38733883 Evaluation and improvement of ammonia  

E-print Network

Atmospheric Environment 37 (2003) 3873颅3883 Evaluation and improvement of ammonia emissions Abstract Two case studies are performed to improve ammonia emissions inputs used to model fine particulate of ammonium sulfate and ammonium nitrate. Ammonia emissions are analyzed in detail for North Carolina

Aneja, Viney P.

481

Covalent Bonding in Ammonia from Several Perspectives Frank Rioux  

E-print Network

Covalent Bonding in Ammonia from Several Perspectives Frank Rioux College of St. Benedict and St in the periodic table have an odd number of electrons, but very few molecules do. For example ammonia, NH3, has-pair for itself. In a proper three-dimensional representation the ammonia molecule has C3v symmetry and looks like

Rioux, Frank

482

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 ...

483

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 ...

484

The Possibility of Separating Two Forms of the Ammonia Molecule  

Microsoft Academic Search

A FEW years ago it was observed by Baly and Duncan (Jour. Chem. Soc., 121, 1008; 1922) that ammonia gas drawn quickly from a cylinder containing liquid ammonia was less rapidly decomposed on a hot platinum wire than gas drawn slowly from the same cylinder, or obtained in certain other ways. They offered as a possible explanation that ammonia molecules

Richard M. Badger

1930-01-01

485

Estimating ammonia volatilization and deposition from fertilized vegetation  

Microsoft Academic Search

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

M. W. Heuer; L. Myles

2010-01-01

486

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...

487

Application of vacuum membrane distillation for ammonia removal  

Microsoft Academic Search

This study aims to investigate the applicability of membrane distillation for ammonia removal from its aqueous solutions. Among the different recognized membrane distillation configurations, vacuum membrane distillation is applied in the present work for ammonia removal. The effects of different operating parameters on ammonia removal from aqueous solutions of different concentrations have been investigated. Experimental results showed that high feed

M. S. EL-Bourawi; M. Khayet; R. Ma; Z. Ding; Z. Li; X. Zhang

2007-01-01

488

A SENSITIVE AND AFFORDABLE COMPACT AMMONIA MONITOR - PHASE II  

EPA Science Inventory

Ammonia has an important role in the chemistry of the atmospheric environment and air quality. Ammonia emissions are a major environmental concern, yet they remain poorly quantified. There is a need for a sensitive ammonia instrument to monitor emissions and evaluate their e...

489

A SENSITIVE AND AFFORDABLE COMPACT AMMONIA MONITOR - PHASE I  

EPA Science Inventory

Ammonia has an important role in the chemistry of the atmospheric environment and air quality. Ammonia emissions are a major environmental concern, yet they remain poorly quantified. There is a need for a sensitive ammonia instrument to monitor emissions and evaluate their eff...

490

Scrap tire recycling in Minnesota  

SciTech Connect

The author discusses the problems associated with scrap tires. For example, surface storing of scrap tires poses a fire hazard and the rainwater trapped in the tire casings is an ideal breeding ground for mosquitoes. Use as a fuel for energy production is unattractive as long as oil retails at its present low price. Past reclamation processes have not met expectations. Legislation alone is not the answer, because scrap tires cannot be regulated out of existence. However, the Minnesota state legislature has come up with an approach that seems to be successful. It has passed the Waste Tire Act, which not only formulates regulations but also provides funding for research and development. Thus, it has established a tire disposal fund for financing construction costs of tire recycling facilities. One of the outcomes was the construction of the St. Louis county Waste Tire Recycling Facility. Through a leasing arrangement with Minneapolis-based Rubber Elastomerics, Inc. (RRE), construction costs financed by the tire disposal fund eventually will be repaid by RRE to the fund. The arrangement is described in detail. By a process also described, RRE produces a product that can be used in thermoset and in thermoplastic compounds. The user can incorporate between 50 percent and 85 percent of the recycled product into a rubber or plastic compound without significantly affecting the physical properties of the compound.

Not Available

1989-10-01

491

Percolation on fitness landscapes: effects of correlation, phenotype, and incompatibilities.  

PubMed

We study how correlations in the random fitness assignment may affect the structure of fitness landscapes, in three classes of fitness models. The first is a phenotype space in which individuals are characterized by a large number n of continuously varying traits. In a simple model of random fitness assignment, viable phenotypes are likely to form a giant connected cluster percolating throughout the phenotype space provided the viability probability is larger than 1/2(n). The second model explicitly describes genotype-to-phenotype and phenotype-to-fitness maps, allows for neutrality at both phenotype and fitness levels, and results in a fitness landscape with tunable correlation length. Here, phenotypic neutrality and correlation between fitnesses can reduce the percolation threshold, and correlations at the point of phase transition between local and global are most conducive to the formation of the giant cluster. In the third class of models, particular combinations of alleles or values of phenotypic characters are "incompatible" in the sense that the resulting genotypes or phenotypes have zero fitness. This setting can be viewed as a generalization of the canonical Bateson-Dobzhansky-Muller model of speciation and is related to K-SAT problems, prominent in computer science. We analyze the conditions for the existence of viable genotypes, their number, as well as the structure and the number of connected clusters of viable genotypes. We show that analysis based on expected values can easily lead to wrong conclusions, especially when fitness correlations are strong. We focus on pairwise incompatibilities between diallelic loci, but we also address multiple alleles, complex incompatibilities, and continuous phenotype spaces. In the case of diallelic loci, the number of clusters is stochastically bounded and each cluster contains a very large sub-cube. Finally, we demonstrate that the discrete NK model shares some signature properties of models with high correlations. PMID:17692873

Gravner, Janko; Pitman, Damien; Gavrilets, Sergey

2007-10-21

492

Urea-N recycling in lactating dairy cows fed diets with 2 different levels of dietary crude protein and starch with or without monensin.  

PubMed

Rumensin (monensin; Elanco Animal Health, Greenfield, IN) has been shown to reduce ammonia production and microbial populations in vitro; thus, it would be assumed to reduce ruminal ammonia production and subsequent urea production and consequently affect urea recycling. The objective of this experiment was to determine the effects of 2 levels of dietary crude protein (CP) and 2 levels of starch, with and without Rumensin on urea-N recycling in lactating dairy cattle. Twelve lactating Holstein dairy cows (107 21 d in milk, 647 kg 37 kg of body weight) were fed diets characterized as having high (16.7%) or low (15.3%) CP with or without Rumensin, while dietary starch levels (23 vs. 29%) were varied between 2 feeding periods with at least 7d of adaptation between measurements. Cows assigned to high or low protein and to Rumensin or no Rumensin remained on those treatments to avoid carryover effects. The diets consisted of approximately 40% corn silage, 20% alfalfa hay, and 40% concentrate mix specific to the treatment diets, with 0.5 kg of wheat straw added to the high starch diets to enhance effective fiber intake. The diets were formulated using Cornell Net Carbohydrate and Protein System (version 6.1), and the low-protein diets were formulated to be deficient for rumen ammonia to create conditions that should enhance the demand for urea recycling. The high-protein diets were formulated to be positive for both rumen ammonia and metabolizable protein. Rumen fluid, urine, feces, and milk samples were collected before and after a 72-h continuous jugular infusion of (15)N(15)N-urea. Total urine and feces were collected during the urea infusions for N balance measurements. Milk yield and dry matter intake were improved in cows fed the higher level of dietary CP and by Rumensin. Ruminal ammonia and milk and plasma urea nitrogen concentrations corresponded to dietary CP concentration. As has been shown in vitro, Rumensin reduced rumen ammonia concentration by approximately 23% but did not affect urea entry rate or gastrointestinal entry rate. Urea entry rate averaged approximately 57% of total N intake for cattle with and without Rumensin, and gastrointestinal rate was similar at 43 and 42% of N intake for cattle fed and not fed Rumensin, respectively. The cattle fed the high-protein diet had a 25% increase in urea entry rate and no effect of starch level was observed for any recycling parameters. Contrary to our hypothesis, Rumensin did not alter urea production and recycling. PMID:24377801

Recktenwald, E B; Ross, D A; Fessenden, S W; Wall, C J; Van Amburgh, M E

2014-03-01

493

Effect of filler auto-assembly on percolation transition in carbon nanotube/polymer composites  

NASA Astrophysics Data System (ADS)

A series of composites with various content of multi-walled carbon nanotubes dispersed in polymer was tested for electrical properties. During isothermal annealing in the melt, dynamic percolation transition induced a tremendous increase in conductivity. The unstable structure also experienced a more than one order of magnitude reduction in percolation threshold. The insulator to conductor transition concurrently became softer, as revealed by a monotonous increase in the critical exponent, gradually departing from the universal value. These large and concomitant changes in percolation transition with annealing time were ascribed to the self-organization of the filler that favors the completion of the conductive network.

Combessis, Anthony; Bayon, Lorr鑞e; Flandin, Lionel

2013-01-01

494

The origin of mouth-exhaled ammonia.  

PubMed

It is known that the oral cavity is a production site for mouth-exhaled NH3. However, the mechanism of NH3 production in the oral cavity has been unclear. Since bacterial urease in the oral cavity has been found to produce ammonia from oral fluid urea, we hypothesize that oral fluid urea is the origin of mouth-exhaled NH3. Our results show that under certain conditions a strong correlation exists between oral fluid urea and oral fluid ammonia (NH4(+)+NH3) (rs = 0.77, p<0.001). We also observe a strong correlation between oral fluid NH3 and mouth-exhaled NH3 (rs = 0.81, p<0.001). We conclude that three main factors affect the mouth-exhaled NH3 concentration: urea concentration, urease activity and oral fluid pH. Bacterial urease catalyses the hydrolysis of oral fluid urea to ammonia (NH4(+)+NH3). Oral fluid ammonia (NH4(+)+NH3) and pH determine the concentration of oral fluid NH3, which evaporates from oral fluid into gas phase and turns to mouth-exhaled NH3. PMID:25080054

Chen, W; Mets鋖, M; Vaittinen, O; Halonen, L

2014-09-01

495

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...

496

Ammonia release method for depositing metal oxides  

DOEpatents

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.

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

1994-12-13

497

Ammonia release method for depositing metal oxides  

DOEpatents

A method is described for 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. 1 figure.

Silver, G.L.; Martin, F.S.

1994-12-13

498

ACUTE TOXICITY OF AMMONIA TO FATHEAD MINNOWS  

EPA Science Inventory

The acute toxicity of ammonia to fathead minnows Pimephales promelas was measured in 35, 96-hour, flow-through tests. The fish were from both wild and hatchery-reared stocks, and ranged in size from 0.1 to 2.3 g. The 96-hour median lethal concentrations (LC50) ranged from 0.75 to...

499

Ammonia in comet P/Halley  

NASA Technical Reports Server (NTRS)

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.

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

1994-01-01

500

AMMONIA REMOVAL FROM MAMMALIAN CELL CULTURE MEDIUM  

EPA Science Inventory

Metabolites such as ammonia and lactic formed during mammalian cell culture can frequently be toxic to the cells themselves beyond a threshold concentration of the metabolites. ell culture conducted in the presence of such accumulated metabolites is therefore limited in productiv...