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Sample records for particulate ecto-nucleotidase cd39

  1. Characterization of circulating microparticle-associated CD39 family ecto-nucleotidases in human plasma.

    PubMed

    Jiang, Z Gordon; Wu, Yan; Csizmadia, Eva; Feldbrügge, Linda; Enjyoji, Keiichi; Tigges, John; Toxavidis, Vasilis; Stephan, Holger; Müller, Christa E; Müller, Christina E; McKnight, C James; Moss, Alan; Robson, Simon C

    2014-12-01

    Phosphohydrolysis of extracellular ATP and ADP is an essential step in purinergic signaling that regulates key pathophysiological processes, such as those linked to inflammation. Classically, this reaction has been known to occur in the pericellular milieu catalyzed by membrane bound cellular ecto-nucleotidases, which can be released in the form of both soluble ecto-enzymes as well as being associated with exosomes. Circulating ecto-nucleoside triphosphate diphosphohydrolase 1 (NTPDase 1/CD39) and adenylate kinase 1 (AK1) activities have been shown to be present in plasma. However, other ecto-nucleotidases have not been characterized in depth. An in vitro ADPase assay was developed to probe the ecto-enzymes responsible for the ecto-nucleotidase activity in human platelet-free plasma, in combination with various specific biochemical inhibitors. Identities of ecto-nucleotidases were further characterized by chromatography, immunoblotting, and flow cytometry of circulating exosomes. We noted that microparticle-bound E-NTPDases and soluble AK1 constitute the highest levels of ecto-nucleotidase activity in human plasma. All four cell membrane expressed E-NTPDases are also found in circulating microparticles in human plasma, inclusive of: CD39, NTPDase 2 (CD39L1), NTPDase 3 (CD39L3), and NTPDase 8. CD39 family members and other ecto-nucleotidases are found on distinct microparticle populations. A significant proportion of the microparticle-associated ecto-nucleotidase activity is sensitive to POM6, inferring the presence of NTPDases, either -2 or/and -3. We have refined ADPase assays of human plasma from healthy volunteers and have found that CD39, NTPDases 2, 3, and 8 to be associated with circulating microparticles, whereas soluble AK1 is present in human plasma. These ecto-enzymes constitute the bulk circulating ADPase activity, suggesting a broader implication of CD39 family and other ecto-enzymes in the regulation of extracellular nucleotide metabolism. PMID

  2. High Expression of Ecto-Nucleotidases CD39 and CD73 in Human Endometrial Tumors

    PubMed Central

    Aliagas, Elisabet; Vidal, August; Texidó, Laura; Ponce, Jordi; Condom, Enric; Martín-Satué, Mireia

    2014-01-01

    One of the strategies used by tumors to evade immunosurveillance is the accumulation of extracellular adenosine, which has immunosupressive and tumor promoting effects. The study of the mechanisms leading to adenosine formation at the tumor interstitium are therefore of great interest in oncology. The dominant pathway generating extracellular adenosine in tumors is the dephosphorylation of ATP by ecto-nucleotidases. Two of these enzymes acting sequentially, CD39 and CD73, efficiently hydrolyze extracellular ATP to adenosine. They have been found to play a crucial role in a variety of tumors, but there were no data concerning endometrial cancer, the most frequent of the invasive tumors of the female genital tract. The aim of the present work is to study the expression of CD39 and CD73 in human endometrial cancer. We have analyzed protein and gene expression, as well as enzyme activity, in type I endometrioid adenocarcinomas and type II serous adenocarcinomas and their nonpathological endometrial counterparts. High levels of both enzymes were found in tumor samples, with significantly increased expression of CD39 in type II serous tumors, which also coincided with the higher tumor grade. Our results reinforce the involvement of the adenosinergic system in cancer, emphasizing the relevance of ecto-nucleotidases as emerging therapeutic targets in oncology. PMID:24707115

  3. Ecto-nucleotidases distribution in human cyclic and postmenopausic endometrium.

    PubMed

    Aliagas, Elisabet; Vidal, August; Torrejón-Escribano, Benjamín; Taco, Maria del Rosario; Ponce, Jordi; de Aranda, Inmaculada Gómez; Sévigny, Jean; Condom, Enric; Martín-Satué, Mireia

    2013-06-01

    Extracellular ATP and its hydrolysis product, adenosine, acting through specific receptors collectively named purinergic receptors, regulate female fertility by influencing the endometrial fluid microenvironment. There are four major groups of ecto-nucleotidases that control the levels of extracellular ATP and adenosine and thus their availability at purinergic receptors: ecto-nucleoside triphosphate diphosphohydrolases (E-NTPDases), ecto-nucleotide pyrophosphatase/phospho-diesterases (E-NPPs), ecto-5'-nucleotidase (5'NT), and alkaline phosphatases (APs). The aim of the present work is to characterize the expression and distribution of ecto-nucleotidases in human endometrium along the menstrual cycle and after menopause, to evaluate their potential utility as fertility markers. We examined proliferative, secretory and atrophic endometria from women without endometrial pathology undergoing hysterectomy. We show that the ecto-nucleotidases are mainly present at endometrial epithelia, both luminal and glandular, and that their expression fluctuates along the cycle and also changes after menopause. An important result was identifying NPP3 as a new biological marker of tubal metaplasia. Our results emphasize the relevance of the study of purinergic signaling in human fertility. PMID:23225236

  4. Polyoxometalates--potent and selective ecto-nucleotidase inhibitors.

    PubMed

    Lee, Sang-Yong; Fiene, Amelie; Li, Wenjin; Hanck, Theodor; Brylev, Konstantin A; Fedorov, Vladimir E; Lecka, Joanna; Haider, Ali; Pietzsch, Hans-Jürgen; Zimmermann, Herbert; Sévigny, Jean; Kortz, Ulrich; Stephan, Holger; Müller, Christa E

    2015-01-15

    Polyoxometalates (POMs) are inorganic cluster metal complexes that possess versatile biological activities, including antibacterial, anticancer, antidiabetic, and antiviral effects. Their mechanisms of action at the molecular level are largely unknown. However, it has been suggested that the inhibition of several enzyme families (e.g., phosphatases, protein kinases or ecto-nucleotidases) by POMs may contribute to their pharmacological properties. Ecto-nucleotidases are cell membrane-bound or secreted glycoproteins involved in the hydrolysis of extracellular nucleotides thereby regulating purinergic (and pyrimidinergic) signaling. They comprise four distinct families: ecto-nucleoside triphosphate diphosphohydrolases (NTPDases), ecto-nucleotide pyrophosphatases/phosphodiesterases (NPPs), alkaline phosphatases (APs) and ecto-5'-nucleotidase (eN). In the present study, we evaluated the inhibitory potency of a series of polyoxometalates as well as chalcogenide hexarhenium cluster complexes at a broad range of ecto-nucleotidases. [Co4(H2O)2(PW9O34)2](10-) (5, PSB-POM142) was discovered to be the most potent inhibitor of human NTPDase1 described so far (Ki: 3.88 nM). Other investigated POMs selectively inhibited human NPP1, [TiW11CoO40](8-) (4, PSB-POM141, Ki: 1.46 nM) and [NaSb9W21O86](18-) (6, PSB-POM143, Ki: 4.98 nM) representing the most potent and selective human NPP1 inhibitors described to date. [NaP5W30O110](14-) (8, PSB-POM144) strongly inhibited NTPDase1-3 and NPP1 and may therefore be used as a pan-inhibitor to block ATP hydrolysis. The polyoxoanionic compounds displayed a non-competitive mechanism of inhibition of NPPs and eN, but appeared to be competitive inhibitors of TNAP. Future in vivo studies with selected inhibitors identified in the current study are warranted. PMID:25449596

  5. Ecto-Nucleotidase Activities of Promastigotes from Leishmania (Viannia) braziliensis Relates to Parasite Infectivity and Disease Clinical Outcome

    PubMed Central

    Leite, Pauline M.; Gomes, Rodrigo S.; Figueiredo, Amanda B.; Serafim, Tiago D.; Tafuri, Wagner L.; de Souza, Carolina C.; Moura, Sandra A. L.; Fietto, Juliana L. R.; Melo, Maria N.; Ribeiro-Dias, Fátima; Oliveira, Milton A. P.; Rabello, Ana; Afonso, Luís C. C.

    2012-01-01

    Background Leishmania (Viannia) braziliensis has been associated with a broad range of clinical manifestations ranging from a simple cutaneous ulcer to destructive mucosal lesions. Factors leading to this diversity of clinical presentations are not clear, but parasite factors have lately been recognized as important in determining disease progression. Given the fact that the activity of ecto-nucleotidases correlates with parasitism and the development of infection, we evaluated the activity of these enzymes in promastigotes from 23 L. braziliensis isolates as a possible parasite-related factor that could influence the clinical outcome of the disease. Methodology/Principal Findings Our results show that the isolates differ in their ability to hydrolyze adenine nucleotides. Furthermore, we observed a positive correlation between the time for peak of lesion development in C57BL/6J mice and enzymatic activity and clinical manifestation of the isolate. In addition, we found that L. (V.) braziliensis isolates obtained from mucosal lesions hydrolyze higher amounts of adenine nucleotides than isolates obtained from skin lesions. One isolate with high (PPS6m) and another with low (SSF) ecto-nucleotidase activity were chosen for further studies. Mice inoculated with PPS6m show delayed lesion development and present larger parasite loads than animals inoculated with the SSF isolate. In addition, PPS6m modulates the host immune response by inhibiting dendritic cell activation and NO production by activated J774 macrophages. Finally, we observed that the amastigote forms from PPS6m and SSF isolates present low enzymatic activity that does not interfere with NO production and parasite survival in macrophages. Conclusions/Significance Our data suggest that ecto-nucleotidases present on the promastigote forms of the parasite may interfere with the establishment of the immune response with consequent impaired ability to control parasite dissemination and this may be an important

  6. Concomitant blockade of P2X-receptors and ecto-nucleotidases by P2-receptor antagonists: functional consequences in rat vas deferens.

    PubMed

    Bültmann, R; Trendelenburg, M; Tuluc, F; Wittenburg, H; Starke, K

    1999-04-01

    In order to assess the consequences of a concomitant blockade of P2X-receptors and ecto-nucleotidases, effects of 13 P2-receptor antagonists were investigated on contractions of the rat vas deferens elicited by alpha,beta-methylene ATP (alpha,beta-MeATP) and ATP and on the removal of ATP from the incubation medium by vas deferens tissue. Increasing concentrations of all antagonists reduced and finally abolished contractions elicited by alpha,beta-MeATP (3 microM), with IC50-values ranging from 1.1 to 100 microM. Pyridoxalphosphate-6-azophenyl-2',4'-disulphonate (PPADS), 6-azophenyl-4-amino-5-hydroxy-naphthalene-1,3-disulphonate (NH02), 4,4'-diisothiocyanatostilbene-2,2'-disulphonate (DIDS) and uniblue A also progressively reduced and finally abolished contractions elicited by ATP (1 mM). 8,8'-[Carbonylbis(imino-3, 1-phenylenecarbonyl-imino)]-bis-(1,3,5-naphthalenetrisulphonate ) (NF023), suramin, pyridoxalphosphate-6-azophenyl-2',5'-disulphonate (iso-PPADS), trypan blue and reactive blue 19, in contrast, caused only partial blockade, by 34-43% maximally; reactive blue 2 and reactive red 2 had no effect; and 6,6'-(1,1'-biphenyl-4,4'-diylbisazo)-bis-4-amino-5-hydroxy-naphtha lene-1,3-disulphonate (NH01) and Evans blue even enhanced the response to ATP. For antagonists causing full or partial inhibition, the IC50-values against ATP were close to those against alpha,beta-MeATP. All antagonists attenuated the removal of ATP, with IC25%-values ranging from 0.8 microM to >320 microM. The results confirm the frequent combination, in one antagonist molecule, of P2-receptor blockade and blockade of ecto-nucleotidases. This dual action underlies the effect of such compounds on contractions of the vas deferens elicited by ATP which, for certain substances (e.g., suramin, reactive blue 2), can be explained by a simple model in which the antagonist simultaneously blocks the degradation of ATP and a single contraction-mediating receptor (P2X1). Several observations, however, do

  7. IL-12 and IL-4 activate a CD39-dependent intrinsic peripheral tolerance mechanism in CD8(+) T cells.

    PubMed

    Noble, Alistair; Mehta, Hema; Lovell, Andrew; Papaioannou, Eleftheria; Fairbanks, Lynette

    2016-06-01

    Immune responses to protein antigens involve CD4(+) and CD8(+) T cells, which follow distinct programs of differentiation. Naïve CD8 T cells rapidly develop cytotoxic T-cell (CTL) activity after T-cell receptor stimulation, and we have previously shown that this is accompanied by suppressive activity in the presence of specific cytokines, i.e. IL-12 and IL-4. Cytokine-induced CD8(+) regulatory T (Treg) cells are one of several Treg-cell phenotypes and are Foxp3(-) IL-10(+) with contact-dependent suppressive capacity. Here, we show they also express high level CD39, an ecto-nucleotidase that degrades extracellular ATP, and this contributes to their suppressive activity. CD39 expression was found to be upregulated on CD8(+) T cells during peripheral tolerance induction in vivo, accompanied by release of IL-12 and IL-10. CD39 was also upregulated during respiratory tolerance induction to inhaled allergen and on tumor-infiltrating CD8(+) T cells. Production of IL-10 and expression of CD39 by CD8(+) T cells was independently regulated, being respectively blocked by extracellular ATP and enhanced by an A2A adenosine receptor agonist. Our results suggest that any CTL can develop suppressive activity when exposed to specific cytokines in the absence of alarmins. Thus negative feedback controls CTL expansion under regulation from both nucleotide and cytokine environment within tissues. PMID:26990545

  8. Regulation of the T Cell Response by CD39.

    PubMed

    Takenaka, Maisa C; Robson, Simon; Quintana, Francisco J

    2016-07-01

    The ectonucleoside triphosphate diphosphohydrolase 1 (ENTPD1, or CD39) catalyzes the phosphohydrolysis of extracellular ATP (eATP) and ADP (eADP) released under conditions of inflammatory stress and cell injury. CD39 generates AMP, which is in turn used by the ecto-5'-nucleotidase CD73 to synthesize adenosine. These ectonucleotidases have a major impact on the dynamic equilibrium of proinflammatory eATP and ADP nucleotides versus immunosuppressive adenosine nucleosides. Indeed, CD39 plays a dominant role in the purinergic regulation of inflammation and the immune response because its expression is influenced by genetic and environmental factors. We review the specific role of CD39 in the kinetic regulation of cellular immune responses in the evolution of disease. We focus on the effects of CD39 on T cells and explore potential clinical applications in autoimmunity, chronic infections, and cancer. PMID:27236363

  9. CD39/Adenosine Pathway Is Involved in AIDS Progression

    PubMed Central

    Limou, Sophie; Younas, Mehwish; Kök, Ayrin; Huë, Sophie; Seddiki, Nabila; Hulin, Anne; Delaneau, Olivier; Schuitemaker, Hanneke; Herbeck, Joshua T.; Mullins, James I.; Muhtarova, Maria; Bensussan, Armand; Zagury, Jean-François; Lelievre, Jean-Daniel; Lévy, Yves

    2011-01-01

    HIV-1 infection is characterized by a chronic activation of the immune system and suppressed function of T lymphocytes. Regulatory CD4+ CD25high FoxP3+CD127low T cells (Treg) play a key role in both conditions. Here, we show that HIV-1 positive patients have a significant increase of Treg-associated expression of CD39/ENTPD1, an ectoenzyme which in concert with CD73 generates adenosine. We show in vitro that the CD39/adenosine axis is involved in Treg suppression in HIV infection. Treg inhibitory effects are relieved by CD39 down modulation and are reproduced by an adenosine-agonist in accordance with a higher expression of the adenosine A2A receptor on patients' T cells. Notably, the expansion of the Treg CD39+ correlates with the level of immune activation and lower CD4+ counts in HIV-1 infected patients. Finally, in a genetic association study performed in three different cohorts, we identified a CD39 gene polymorphism that was associated with down-modulated CD39 expression and a slower progression to AIDS. PMID:21750674

  10. CD39 Expression Identifies Terminally Exhausted CD8+ T Cells

    PubMed Central

    Adland, Emily; Yates, Kathleen; Pauken, Kristen E.; Cosgrove, Cormac; Ledderose, Carola; Junger, Wolfgang G.; Robson, Simon C.; Wherry, E. John; Alter, Galit; Goulder, Philip J. R.; Klenerman, Paul; Sharpe, Arlene H.; Lauer, Georg M.; Haining, W. Nicholas

    2015-01-01

    Exhausted T cells express multiple co-inhibitory molecules that impair their function and limit immunity to chronic viral infection. Defining novel markers of exhaustion is important both for identifying and potentially reversing T cell exhaustion. Herein, we show that the ectonucleotidse CD39 is a marker of exhausted CD8+ T cells. CD8+ T cells specific for HCV or HIV express high levels of CD39, but those specific for EBV and CMV do not. CD39 expressed by CD8+ T cells in chronic infection is enzymatically active, co-expressed with PD-1, marks cells with a transcriptional signature of T cell exhaustion and correlates with viral load in HIV and HCV. In the mouse model of chronic Lymphocytic Choriomeningitis Virus infection, virus-specific CD8+ T cells contain a population of CD39high CD8+ T cells that is absent in functional memory cells elicited by acute infection. This CD39high CD8+ T cell population is enriched for cells with the phenotypic and functional profile of terminal exhaustion. These findings provide a new marker of T cell exhaustion, and implicate the purinergic pathway in the regulation of T cell exhaustion. PMID:26485519

  11. CD39 and CD73 in immunity and inflammation

    PubMed Central

    Antonioli, Luca; Pacher, Pál; Vizi, E. Sylvester; Haskó, György

    2013-01-01

    The enzymatic activities of CD39 and CD73 play strategic roles in calibrating the duration, magnitude, and chemical nature of purinergic signals delivered to immune cells through the conversion of ADP/ATP to AMP and AMP to adenosine, respectively. This drives a shift from an ATP-driven proinflammatory environment to an anti-inflammatory milieu induced by adenosine. The CD39/CD73 pathway changes dynamically with the pathophysiological context in which it is embedded. It is becoming increasingly appreciated that altering this catabolic machinery can change the course or dictate the outcome of several pathophysiological events, such as AIDS, autoimmune diseases, infections, atherosclerosis, ischemia-reperfusion injury, and cancer, suggesting these ecto-enzymes are novel therapeutic targets for managing a variety of disorders. PMID:23601906

  12. Expression of CD39 on Activated T Cells Impairs their Survival in Older Individuals.

    PubMed

    Fang, Fengqin; Yu, Mingcan; Cavanagh, Mary M; Hutter Saunders, Jessica; Qi, Qian; Ye, Zhongde; Le Saux, Sabine; Sultan, William; Turgano, Emerson; Dekker, Cornelia L; Tian, Lu; Weyand, Cornelia M; Goronzy, Jörg J

    2016-02-01

    In an immune response, CD4(+) T cells expand into effector T cells and then contract to survive as long-lived memory cells. To identify age-associated defects in memory cell formation, we profiled activated CD4(+) T cells and found an increased induction of the ATPase CD39 with age. CD39(+) CD4(+) T cells resembled effector T cells with signs of metabolic stress and high susceptibility to undergo apoptosis. Pharmacological inhibition of ATPase activity dampened effector cell differentiation and improved survival, suggesting that CD39 activity influences T cell fate. Individuals carrying a low-expressing CD39 variant responded better to vaccination with an increase in vaccine-specific memory T cells. Increased inducibility of CD39 after activation may contribute to the impaired vaccine response with age. PMID:26832412

  13. Interactions between the transmembrane domains of CD39: identification of interacting residues by yeast selection

    PubMed Central

    Paavilainen, Sari; Guidotti, Guido

    2015-01-01

    Rat CD39, a membrane-bound ectonucleoside triphosphate diphosphohydrolase that hydrolyzes extracellular nucleoside tri- and diphosphates, is anchored to the membrane by two transmembrane domains at the two ends of the molecule. The transmembrane domains are important for enzymatic activity, as mutants lacking one or both of these domains have a fraction of the enzymatic activity of the wild-type CD39. We investigated the interactions between the transmembrane domains by using a strain of yeast that requires surface expression of CD39 for growth. Random mutagenesis of selected amino acid residues in the N-terminal transmembrane domain revealed that the presence of charged amino acids at these positions prevents expression of functional protein. Rescue of the growth of these mutants by complementary mutations on selected residues of the C-terminal transmembrane domain indicates that there is contact between particular faces of the transmembrane domains. PMID:26258004

  14. NADH oxidase-dependent CD39 expression by CD8(+) T cells modulates interferon gamma responses via generation of adenosine.

    PubMed

    Bai, Aiping; Moss, Alan; Rothweiler, Sonja; Longhi, Maria Serena; Wu, Yan; Junger, Wolfgang G; Robson, Simon C

    2015-01-01

    Interferon gamma (IFNγ)-producing CD8(+) T cells (Tc1) play important roles in immunological disease. We now report that CD3/CD28-mediated stimulation of CD8(+) T cells to generate Tc1 cells, not only increases IFNγ production but also boosts the generation of reactive oxygen species (ROS) and augments expression of CD39. Inhibition of NADPH oxidases or knockdown of gp91phox in CD8(+) T cells abrogates ROS generation, which in turn modulates JNK and NFκB signalling with decreases in both IFNγ levels and CD39 expression. CD39(+)CD8(+) T cells substantially inhibit IFNγ production by CD39(-)CD8(+) T cells via the paracrine generation of adenosine, which is operational via adenosine type 2A receptors. Increases in numbers of CD39(+)CD8(+) T cells and associated enhancements in ROS signal transduction are noted in cells from patients with Crohn's disease. Our findings provide insights into Tc1-mediated IFNγ responses and ROS generation and link these pathways to CD39/adenosine-mediated effects in immunological disease. PMID:26549640

  15. Expression of CD39 by human peripheral blood CD4+CD25+ T cells denotes a regulatory memory phenotype

    PubMed Central

    Dwyer, Karen M.; Hanidziar, Dusan; Putheti, Prabhakar; Hill, Prue A; Pommey, Sandra; McRae, Jennifer L; Winterhalter, Adam; Doherty, Glen; Deaglio, Silvia; Koulmanda, Maria; Gao, Wenda; Robson, Simon C.; Strom, Terry B.

    2010-01-01

    We have shown that CD39 and CD73 are co-expressed on the surface of murine CD4+Foxp3+ regulatory T cells (Treg) and generate extracellular adenosine, contributing to Treg immunosuppressive activity. We now describe that CD39, independently of CD73, is expressed by a subset of blood derived human CD4+CD25+CD127lo T regulatory cells (Treg), defined by robust expression of Foxp3. A further distinct population of CD4+CD39+ T lymphocytes can be identified, which do not express CD25 and FoxP3 and exhibit the memory effector cellular phenotype. Differential expression of CD25 and CD39 on circulating CD4+ T cells distinguishes between Treg and pathogenic cellular populations that secrete pro-inflammatory cytokines such as IFNγ and IL-17. These latter cell populations are increased, with a concomitant decrease in the CD4+CD25+CD39+ Tregs, in the peripheral blood of patients with renal allograft rejection. We conclude that the ectonucleotidase CD39 is a useful and dynamic lymphocytes surface marker that can be used to identify different peripheral blood T cell populations to allow tracking of these in health and disease, as in renal allograft rejection. PMID:20977632

  16. NADH oxidase-dependent CD39 expression by CD8+ T cells modulates interferon gamma responses via generation of adenosine

    PubMed Central

    Bai, Aiping; Moss, Alan; Rothweiler, Sonja; Serena Longhi, Maria; Wu, Yan; Junger, Wolfgang G.; Robson, Simon C.

    2015-01-01

    Interferon gamma (IFNγ)-producing CD8+ T cells (Tc1) play important roles in immunological disease. We now report that CD3/CD28-mediated stimulation of CD8+ T cells to generate Tc1 cells, not only increases IFNγ production but also boosts the generation of reactive oxygen species (ROS) and augments expression of CD39. Inhibition of NADPH oxidases or knockdown of gp91phox in CD8+ T cells abrogates ROS generation, which in turn modulates JNK and NFκB signalling with decreases in both IFNγ levels and CD39 expression. CD39+CD8+ T cells substantially inhibit IFNγ production by CD39−CD8+ T cells via the paracrine generation of adenosine, which is operational via adenosine type 2A receptors. Increases in numbers of CD39+CD8+ T cells and associated enhancements in ROS signal transduction are noted in cells from patients with Crohn's disease. Our findings provide insights into Tc1-mediated IFNγ responses and ROS generation and link these pathways to CD39/adenosine-mediated effects in immunological disease. PMID:26549640

  17. Low expression of CD39 on regulatory T cells as a biomarker for resistance to methotrexate therapy in rheumatoid arthritis

    PubMed Central

    Peres, Raphael Sanches; Liew, Foo Y.; Talbot, Jhimmy; Carregaro, Vanessa; Oliveira, Rene D.; Almeida, Sergio L.; França, Rafael F. O.; Donate, Paula B.; Pinto, Larissa G.; Ferreira, Flavia I. S.; Costa, Diego L.; Demarque, Daniel P.; Gouvea, Dayana Rubio; Lopes, Norberto P.; Queiroz, Regina Helena C.; Silva, Joao Santana; Figueiredo, Florencio; Alves-Filho, Jose Carlos; Cunha, Thiago M.; Ferreira, Sérgio H.; Louzada-Junior, Paulo; Cunha, Fernando Q.

    2015-01-01

    Rheumatoid arthritis (RA) is an inflammatory autoimmune disease characterized by joint destruction and severe morbidity. Methotrexate (MTX) is the standard first-line therapy of RA. However, about 40% of RA patients are unresponsive to MTX treatment. Regulatory T cells (Tregs, CD4+CD25+FoxP3+) are thought to play an important role in attenuating RA. To investigate the role of Tregs in MTX resistance, we recruited 122 RA patients (53 responsive, R-MTX; 69 unresponsive, UR-MTX) and 33 healthy controls. Three months after MTX treatment, R-MTX but not UR-MTX showed higher frequency of peripheral blood CD39+CD4+CD25+FoxP3+ Tregs than the healthy controls. Tregs produce adenosine (ADO) through ATP degradation by sequential actions of two cell surface ectonucleotidases: CD39 and CD73. Tregs from UR-MTX expressed a lower density of CD39, produced less ADO, and had reduced suppressive activity than Tregs from R-MTX. In a prospective study, before MTX treatment, UR-MTX expressed a lower density of CD39 on Tregs than those of R-MTX or control (P < 0.01). In a murine model of arthritis, CD39 blockade reversed the antiarthritic effects of MTX treatment. Our results demonstrate that MTX unresponsiveness in RA is associated with low expression of CD39 on Tregs and the decreased suppressive activity of these cells through reduced ADO production. Our findings thus provide hitherto unrecognized mechanism of immune regulation in RA and on mode of action of MTX. Furthermore, our data suggest that low expression of CD39 on Tregs could be a noninvasive biomarker for identifying MTX-resistant RA patients. PMID:25675517

  18. Low expression of CD39 on regulatory T cells as a biomarker for resistance to methotrexate therapy in rheumatoid arthritis.

    PubMed

    Peres, Raphael Sanches; Liew, Foo Y; Talbot, Jhimmy; Carregaro, Vanessa; Oliveira, Rene D; Almeida, Sergio L; França, Rafael F O; Donate, Paula B; Pinto, Larissa G; Ferreira, Flavia I S; Costa, Diego L; Demarque, Daniel P; Gouvea, Dayana Rubio; Lopes, Norberto P; Queiroz, Regina Helena C; Silva, Joao Santana; Figueiredo, Florencio; Alves-Filho, Jose Carlos; Cunha, Thiago M; Ferreira, Sérgio H; Louzada-Junior, Paulo; Cunha, Fernando Q

    2015-02-24

    Rheumatoid arthritis (RA) is an inflammatory autoimmune disease characterized by joint destruction and severe morbidity. Methotrexate (MTX) is the standard first-line therapy of RA. However, about 40% of RA patients are unresponsive to MTX treatment. Regulatory T cells (Tregs, CD4(+)CD25(+)FoxP3(+)) are thought to play an important role in attenuating RA. To investigate the role of Tregs in MTX resistance, we recruited 122 RA patients (53 responsive, R-MTX; 69 unresponsive, UR-MTX) and 33 healthy controls. Three months after MTX treatment, R-MTX but not UR-MTX showed higher frequency of peripheral blood CD39(+)CD4(+)CD25(+)FoxP3(+) Tregs than the healthy controls. Tregs produce adenosine (ADO) through ATP degradation by sequential actions of two cell surface ectonucleotidases: CD39 and CD73. Tregs from UR-MTX expressed a lower density of CD39, produced less ADO, and had reduced suppressive activity than Tregs from R-MTX. In a prospective study, before MTX treatment, UR-MTX expressed a lower density of CD39 on Tregs than those of R-MTX or control (P < 0.01). In a murine model of arthritis, CD39 blockade reversed the antiarthritic effects of MTX treatment. Our results demonstrate that MTX unresponsiveness in RA is associated with low expression of CD39 on Tregs and the decreased suppressive activity of these cells through reduced ADO production. Our findings thus provide hitherto unrecognized mechanism of immune regulation in RA and on mode of action of MTX. Furthermore, our data suggest that low expression of CD39 on Tregs could be a noninvasive biomarker for identifying MTX-resistant RA patients. PMID:25675517

  19. Inhibition of neutrophils by hypertonic saline involves pannexin-1, CD39, CD73, and other ectonucleotidases

    PubMed Central

    Chen, Yu; Bao, Yi; Zhang, Jingping; Woehrle, Tobias; Sumi, Yuka; Ledderose, Stephan; Li, Xiaoou; Ledderose, Carola; Junger, Wolfgang G.

    2015-01-01

    Hypertonic saline (HS) resuscitation has been studied as a possible strategy to reduce PMN activation and tissue damage in trauma patients. HS blocks PMNs by ATP release and stimulation of A2a adenosine receptors. Here we studied the underlying mechanisms in search of possible reasons for the inconsistent results of recent clinical trials with HS resuscitation. Purified human PMNs or PMNs in whole blood were treated with HS to simulate hypertonicity levels found after HS resuscitation (40 mM beyond isotonic levels). ATP release was measured with a luciferase assay. PMN activation was assessed by measuring oxidative burst. The pannexin-1 (panx1) inhibitor 10panx1 and the gap junction inhibitor carbenoxolone (CBX) blocked ATP release from PMNs in purified and whole blood preparations, indicating that HS releases ATP via panx1 and gap junction channels. HS blocked fMLP-induced PMN activation by 40% in purified PMN preparations and by 60% in whole blood. These inhibitory effects were abolished by 10panx1 but only partially reduced by CBX, which indicates that panx1 has a central role in the immunomodulatory effects of HS. Inhibition of the ectonucleotidases CD39 and CD73 abolished the suppressive effect of HS on purified PMN cultures but only partially reduced the effect of HS in whole blood. These findings suggest redundant mechanisms in whole blood that may strengthen the immunomodulatory effect of HS in vivo. We conclude that HS resuscitation exerts anti-inflammatory effects that involve panx1, CD39, CD73, and other ectonucleotidases, which produce the adenosine that blocks PMNs by stimulating their A2a receptors. Our findings shed new light on the immunomodulatory mechanisms of HS and suggest possible new strategies to improve the clinical efficacy of hypertonic resuscitation. PMID:26009814

  20. Cancer exosomes express CD39 and CD73, which suppress T cells through adenosine production.

    PubMed

    Clayton, Aled; Al-Taei, Saly; Webber, Jason; Mason, Malcolm D; Tabi, Zsuzsanna

    2011-07-15

    Extracellular adenosine is elevated in cancer tissue, and it negatively regulates local immune responses. Adenosine production from extracellular ATP has attracted attention as a mechanism of regulatory T cell-mediated immune regulation. In this study, we examined whether small vesicles secreted by cancer cells, called exosomes, contribute to extracellular adenosine production and hence modulate immune effector cells indirectly. We found exosomes from diverse cancer cell types exhibit potent ATP- and 5'AMP-phosphohydrolytic activity, partly attributed to exosomally expressed CD39 and CD73, respectively. Comparable levels of activity were seen with exosomes from pleural effusions of mesothelioma patients. In such fluids, exosomes accounted for 20% of the total ATP-hydrolytic activity. Exosomes can perform both hydrolytic steps sequentially to form adenosine from ATP. This exosome-generated adenosine can trigger a cAMP response in adenosine A(2A) receptor-positive but not A(2A) receptor-negative cells. Similarly, significantly elevated cAMP was also triggered in Jurkat cells by adding exosomes with ATP but not by adding exosomes or ATP alone. A proportion of healthy donor T cells constitutively express CD39 and/or CD73. Activation of T cells by CD3/CD28 cross-linking could be inhibited by exogenously added 5'AMP in a CD73-dependent manner. However, 5'AMP converted to adenosine by exosomes inhibits T cell activation independently of T cell CD73 expression. This T cell inhibition was mediated through the adenosine A(2A) receptor. In summary, the data highlight exosome enzymic activity in the production of extracellular adenosine, and this may play a contributory role in negative modulation of T cells in the tumor environment. PMID:21677139

  1. Inhibition of Neutrophils by Hypertonic Saline Involves Pannexin-1, CD39, CD73, and Other Ectonucleotidases.

    PubMed

    Chen, Yu; Bao, Yi; Zhang, Jingping; Woehrle, Tobias; Sumi, Yuka; Ledderose, Stephan; Li, Xiaoou; Ledderose, Carola; Junger, Wolfgang G

    2015-09-01

    Hypertonic saline (HS) resuscitation has been studied as a possible strategy to reduce polymorphonuclear neutrophil (PMN) activation and tissue damage in trauma patients. Hypertonic saline blocks PMNs by adenosine triphosphate (ATP) release and stimulation of A2a adenosine receptors. Here, we studied the underlying mechanisms in search of possible reasons for the inconsistent results of recent clinical trials with HS resuscitation. Purified human PMNs or PMNs in whole blood were treated with HS to simulate hypertonicity levels found after HS resuscitation (40 mmol/L beyond isotonic levels). Adenosine triphosphate release was measured with a luciferase assay. Polymorphonuclear neutrophil activation was assessed by measuring oxidative burst. The pannexin-1 (panx1) inhibitor panx1 and the gap junction inhibitor carbenoxolone (CBX) blocked ATP release from PMNs in purified and whole blood preparations, indicating that HS releases ATP via panx1 and gap junction channels. Hypertonic saline blocked N-formyl-Met-Leu-Phe-induced PMN activation by 40% in purified PMN preparations and by 60% in whole blood. These inhibitory effects were abolished by panx1 but only partially reduced by CBX, which indicates that panx1 has a central role in the immunomodulatory effects of HS. Inhibition of the ectonucleotidases CD39 and CD73 abolished the suppressive effect of HS on purified PMN cultures but only partially reduced the effect of HS in whole blood. These findings suggest redundant mechanisms in whole blood that may strengthen the immunomodulatory effect of HS in vivo. We conclude that HS resuscitation exerts anti-inflammatory effects that involve panx1, CD39, CD73, and other ectonucleotidases, which produce the adenosine that blocks PMNs by stimulating their A2a receptors. Our findings shed new light on the immunomodulatory mechanisms of HS and suggest possible new strategies to improve the clinical efficacy of hypertonic resuscitation. PMID:26009814

  2. Human CD4+CD39+ regulatory T cells produce adenosine upon co-expression of surface CD73 or contact with CD73+ exosomes or CD73+ cells

    PubMed Central

    Schuler, P J; Saze, Z; Hong, C-S; Muller, L; Gillespie, D G; Cheng, D; Harasymczuk, M; Mandapathil, M; Lang, S; Jackson, E K; Whiteside, T L

    2014-01-01

    While murine CD4+CD39+ regulatory T cells (Treg) co-express CD73 and hydrolyze exogenous (e) adenosine triphosphate (ATP) to immunosuppressive adenosine (ADO), surface co-expression of CD73 on human circulating CD4+CD39+ Treg is rare. Therefore, the ability of human Treg to produce and utilize ADO for suppression remains unclear. Using mass spectrometry, we measured nucleoside production by subsets of human CD4+CD39+ and CD4+CD39(–)CD73+ T cells or CD19+ B cells isolated from blood of 30 volunteers and 14 cancer patients. CD39 and CD73 expression was evaluated by flow cytometry, Western blots, confocal microscopy or reverse transcription–polymerase chain reaction (RT–PCR). Circulating CD4+CD39+ Treg which hydrolyzed eATP to 5′-AMP contained few intracytoplasmic granules and had low CD73 mRNA levels. Only ∼1% of these Treg were CD39+CD73+. In contrast, CD4+CD39negCD73+ T cells contained numerous CD73+ granules in the cytoplasm and strongly expressed surface CD73. In vitro-generated Treg (Tr1) and most B cells were CD39+CD73+. All these CD73+ T cell subsets and B cells hydrolyzed 5′-AMP to ADO. Exosomes isolated from plasma of normal control (NC) or cancer patients carried enzymatically active CD39 and CD73+ and, when supplied with eATP, hydrolyzed it to ADO. Only CD4+CD39+ Treg co-incubated with CD4+CD73+ T cells, B cells or CD39+CD73+ exosomes produced ADO. Thus, contact with membrane-tethered CD73 was sufficient for ADO production by CD4+CD39+ Treg. In microenvironments containing CD4+CD73+ T cells, B cells or CD39+CD73+ exosomes, CD73 is readily available to CD4+CD39+CD73neg Treg for the production of immunosuppressive ADO. PMID:24749746

  3. Sesamin protects against renal ischemia reperfusion injury by promoting CD39-adenosine-A2AR signal pathway in mice

    PubMed Central

    Li, Ke; Gong, Xia; Kuang, Ge; Jiang, Rong; Wan, Jingyuan; Wang, Bin

    2016-01-01

    Ischemia reperfusion injury (IRI) is a leading cause of acute kidney injury with high morbidity and mortality due to limited therapy. Here, we examine whether sesamin attenuates renal IRI in an animal model and explore the underlying mechanisms. Male mice were subjected to right renal ischemia for 30 min followed by reperfusion for 24 h with sesamin (100 mg/kg) during which the left kidney was removed. Renal damage and function were assessed subsequently. The results showed that sesamin reduced kidney ischemia reperfusion injury, as assessed by decreased serum creatinine (Scr) and Blood urea nitrogen (BUN), alleviated tubular damage and apoptosis. In addition, sesamin inhibited neutrophils infiltration and pro-inflammatory cytokines tumor necrosis factor (TNF)-α and interleukin (IL)-1β production in IR-preformed kidney. Notably, sesamin promoted the expression of CD39, A2A adenosine receptor (A2AAR), and A2BAR mRNA and protein as well as adenosine production. Furthermore, CD39 inhibitor or A2AR antagonist abolished partly the protection of sesamin in kidney IRI. In conclusion, sesamin could effectively protect kidney from IRI by inhibiting inflammatory responses, which might be associated with promoting the adenosine-CD39-A2AR signaling pathway. PMID:27347331

  4. Altered E-NTPDase/E-ADA activities and CD39 expression in platelets of sickle cell anemia patients.

    PubMed

    Castilhos, Lívia G; Doleski, Pedro H; Adefegha, Stephen A; Becker, Lara V; Ruchel, Jader B; Leal, Daniela B R

    2016-04-01

    Sickle cell anemia (SCA) is a hemoglobinopathy characterized by hemolysis and vaso-occlusions caused by rigidly distorted red blood cells. Sickle cell crisis is associated with extracellular release of nucleotides and platelets, which are critical mediators of hemostasis participating actively in purinergic thromboregulatory enzymes system.This study aimed to investigate the activities of purinergic system ecto-enzymes present on the platelet surface as well as CD39 and CD73 expressions on platelets of SCA treated patients. Fifteen SCA treated patients and 30 health subjects (control group) were selected. Ecto-nucleoside triphosphate diphosphohydrolase (E-NTPDase), ecto-5'-nucleotidase (E-5'-NT) and ecto-adenosine deaminase (E-ADA) activities were measured in platelets isolated from these individuals. Results demonstrated an increase of 41 % in the E-NTPDase for ATP hydrolysis, 52% for ADP hydrolysis and 60 % in the E-ADA activity in SCA patients (P<0.05); however, a two folds decrease in the CD39 expression in platelets was observed in the same group (P<0.01). The increased E-NTPDase activity could be a compensatory mechanism associated with the low expression of CD39 in platelets. Besides, alteration of these enzymes activities suggests that the purinergic system could be involved in the thromboregulatory process in SCA patients. PMID:27044834

  5. CD39 is a negative regulator of P2X7-mediated inflammatory cell death in mast cells

    PubMed Central

    2014-01-01

    Background Mast cells (MCs) are major contributors to an inflammatory milieu. One of the most potent drivers of inflammation is the cytokine IL-1β, which is produced in the cytoplasm in response to danger signals like LPS. Several controlling mechanisms have been reported which limit the release of IL-1β. Central to this regulation is the NLRP3 inflammasome, activation of which requires a second danger signal with the capacity to subvert the homeostasis of lysosomes and mitochondria. High concentrations of extracellular ATP have the capability to perturb the plasma membrane by activation of P2X7 channels and serve as such a danger signal. In this study we investigate the role of P2X7 channels and the ecto-5´-nucleotidase CD39 in ATP-triggered release of IL-1β from LPS-treated mast cells. Results We report that in MCs CD39 sets an activation threshold for the P2X7-dependent inflammatory cell death and concomitant IL-1β release. Knock-out of CD39 or stimulation with non-hydrolysable ATP led to a lower activation threshold for P2X7-dependent responses. We found that stimulation of LPS-primed MCs with high doses of ATP readily induced inflammatory cell death. Yet, cell death-dependent release of IL-1β yielded only minute amounts of IL-1β. Intriguingly, stimulation with low ATP concentrations augmented the production of IL-1β in LPS-primed MCs in a P2X7-independent but caspase-1-dependent manner. Conclusion Our study demonstrates that the fine-tuned interplay between ATP and different surface molecules recognizing or modifying ATP can control inflammatory and cell death decisions. PMID:25184735

  6. CD39/NTPDase-1 expression and activity in human umbilical vein endothelial cells are differentially regulated by leaf extracts from Rubus caesius and Rubus idaeus.

    PubMed

    Dudzinska, Dominika; Luzak, Boguslawa; Boncler, Magdalena; Rywaniak, Joanna; Sosnowska, Dorota; Podsedek, Anna; Watala, Cezary

    2014-09-01

    Many experimental studies have demonstrated the favorable biological activities of plants belonging to the genus Rubus, but little is known of the role of Rubus leaf extracts in the modulation of the surface membrane expression and activity of endothelial apyrase. The aim of this study was to assess the influence of 1-15 μg/ml Rubus extracts on CD39 expression and enzymatic activity, and on the activation (ICAM-1 expression) and viability of human umbilical vein endothelial cells (HUVEC). The polyphenolic contents and antioxidative capacities of extracts from dewberry (R. caesius L.) and raspberry (R. idaeus L.) leaves were also investigated. The techniques applied were flow cytometry (endothelial surface membrane expression of ICAM-1 and CD39), malachite green assay (CD39 activity), HPLC-DAD (quantitative analysis of polyphenolic extract), ABTS, DPPH and FRAP spectrometric assays (antioxidant capacity), and the MTT test (cell viability). Significantly increased CD39 expressions and significantly decreased ATPDase activities were found in the cells treated with 15 μg/ml of either extract compared to the results for the controls. Neither of the extracts affected cell proliferation, but both significantly augmented endothelial cell ICAM-1 expression. The overall antioxidant capacities of the examined extracts remained relatively high and corresponded well to the determined total polyphenol contents. Overall, the results indicate that under in vitro conditions dewberry and raspberry leaf extracts have unfavorable impact on endothelial cells. PMID:25034034

  7. P2X1 receptor inhibition and soluble CD39 administration as novel approaches to widen the cardiovascular therapeutic window

    PubMed Central

    Fung, C.Y. Eleanor; Marcus, Aaron J.; Broekman, M. Johan; Mahaut-Smith, Martyn P.

    2010-01-01

    Thrombus formation at sites of disrupted atherosclerotic plaques is a leading cause of death and disability worldwide. Although the platelet is now recognized to be a central regulator of thrombus formation, development of antiplatelet reagents that selectively target thrombosis over hemostasis represents a challenge. Existing prophylactic antiplatelet therapies are centered on the use of aspirin, an irreversible cyclo-oxygenase inhibitor, and a thienopyridine such as clopidogrel (Plavix), which inactivates the ADP-stimulated P2Y12 receptor. Whilst these compounds are widely used and have beneficial effects for patients, their antithrombotic benefit is complicated by an elevated bleeding risk and substantial or partial “resistance”. Moreover, combination therapy with these two drugs increases the hemorrhagic risk even further. This review explores the possibility of inhibiting the platelet-surface ionotropic P2X1 receptor and/or elevating CD39/NTPDase1 activity as new therapeutic approaches to reduce overall platelet reactivity and recruitment of surrounding platelets at pro-thrombotic locations. Since both proteins affect platelet activation at an early stage in the events leading to thrombosis, but are less crucial in hemostasis, they provide new strategies to widen the cardiovascular therapeutic window without compromising safety. PMID:19467446

  8. The ecto-ATPDase CD39 is involved in the acquisition of the immunoregulatory phenotype by M-CSF-macrophages and ovarian cancer tumor-associated macrophages: Regulatory role of IL-27.

    PubMed

    d'Almeida, Sènan M; Kauffenstein, Gilles; Roy, Charlotte; Basset, Laetitia; Papargyris, Loukas; Henrion, Daniel; Catros, Véronique; Ifrah, Norbert; Descamps, Philippe; Croue, Anne; Jeannin, Pascale; Grégoire, Marc; Delneste, Yves; Tabiasco, Julie

    2016-07-01

    Tumor-associated macrophages (TAM) are immunosuppressive cells that can massively accumulate in the tumor microenvironment. In patients with ovarian cancer, their density is correlated with poor prognosis. Targeting mediators that control the generation or the differentiation of immunoregulatory macrophages represents a therapeutic challenge to overcome tumor-associated immunosuppression. The ectonucleotidase CD39 hydrolyzes ATP into extracellular adenosine that exhibits potent immunosuppressive properties when signaling through the A2A adenosine receptor. We report here that CD14(+) CD163(+) TAM isolated from ovarian cancer patients and macrophages generated in vitro with M-CSF, express high levels of the membrane ectonucleotidase CD39 compared to classically activated macrophages. The CD39 inhibitor POM-1 and adenosine deaminase (ADA) diminished some of the immunosuppressive functions of CD14(high) CD163(high) CD39(high) macrophages, such as IL-10 secretion. We identified the cytokine IL-27, secreted by tumor-infiltrating neutrophils, located close to infiltrating CD163(+) macrophages, as a major rheostat of CD39 expression and consequently, on the acquisition of immunoregulatory properties by macrophages. Accordingly, the depletion of IL-27 downregulated CD39 and PD-L1 expression as well as IL-10 secretion by M-CSF-macrophages. Collectively, these data suggest that CD39, drived by IL-27 and CD115 ligands in ovarian cancer, maintains the immunosuppressive phenotype of TAM. This work brings new information on the acquisition of immunosuppressive properties by tumor-infiltrating macrophages. PMID:27622030

  9. Extract from Ribes nigrum leaves in vitro activates nitric oxide synthase (eNOS) and increases CD39 expression in human endothelial cells.

    PubMed

    Luzak, Boguslawa; Boncler, Magdalena; Rywaniak, Joanna; Dudzinska, Dominika; Rozalski, Marek; Krajewska, Urszula; Balcerczak, Ewa; Podsedek, Anna; Redzynia, Malgorzata; Watala, Cezary

    2014-12-01

    The aim of the present study was to evaluate whether blackcurrant leaf extract (BLE) modulates endothelium antithrombotic function, namely increases the expression/activity of ADPase (CD39) and augments the production of nitric oxide in human umbilical vein endothelial cells (HUVEC). It was found that BLE with proanthocyanidins (60 % of the total polyphenol content) increased the CD39-positive endothelial cell fraction (up to 10 % for 2.5 μg/ml, and up to 33 % for 15 μg/ml, p < 0.05 or less) in a concentration-dependent manner, and enhanced endothelial nitric oxide synthase (eNOS) activation (T495 phosphorylation decreased by 31 ± 6 % for 2.5 μg/ml and 48 ± 6 % for 15 μg/ml; S1177 phosphorylation increased by 13 ± 3 % for 2.5 μg/ml and 18 ± 7 % for 15 μg/ml, compared to untreated cells, p < 0.05 or less). Additionally, incubation for 24 or 48 h with BLE at a lower range of polyphenol concentrations, significantly increased cell viability with a maximal effect at 2.5 μg/ml (viability increased by 24.8 ± 1.0 % for 24 h and by 32.5 ± 2.7 % for 48-h time incubation, p < 0.0001). The increased CD39 expression and the increased eNOS activation in HUVEC can be regarded as the beneficial markers of the improvement of antiplatelet action of endothelial cells. Unexpectedly, these assumptions were not confirmed in the experimental model of platelet-endothelial cell interactions. These observations lead to the conclusion that BLE may improve endothelial cell viability at low physiological concentrations without affecting the antiplatelet action of endothelium. PMID:25407137

  10. Alterations in the adenosine metabolism and CD39/CD73 adenosinergic machinery cause loss of Treg cell function and autoimmunity in ADA-deficient SCID

    PubMed Central

    Sauer, Aisha V.; Brigida, Immacolata; Carriglio, Nicola; Jofra Hernandez, Raisa; Scaramuzza, Samantha; Clavenna, Daniela; Sanvito, Francesca; Poliani, Pietro L.; Gagliani, Nicola; Carlucci, Filippo; Tabucchi, Antonella; Roncarolo, Maria Grazia; Traggiai, Elisabetta; Villa, Anna

    2012-01-01

    Adenosine acts as anti-inflammatory mediator on the immune system and has been described in regulatory T cell (Treg)–mediated suppression. In the absence of adenosine deaminase (ADA), adenosine and other purine metabolites accumulate, leading to severe immunodeficiency with recurrent infections (ADA-SCID). Particularly ADA-deficient patients with late-onset forms and after enzyme replacement therapy (PEG-ADA) are known to manifest immune dysregulation. Herein we provide evidence that alterations in the purine metabolism interfere with Treg function, thereby contributing to autoimmune manifestations in ADA deficiency. Tregs isolated from PEG-ADA–treated patients are reduced in number and show decreased suppressive activity, whereas they are corrected after gene therapy. Untreated murine ADA−/− Tregs show alterations in the plasma membrane CD39/CD73 ectonucleotidase machinery and limited suppressive activity via extracellular adenosine. PEG-ADA–treated mice developed multiple autoantibodies and hypothyroidism in contrast to mice treated with bone marrow transplantation or gene therapy. Tregs isolated from PEG-ADA–treated mice lacked suppressive activity, suggesting that this treatment interferes with Treg functionality. The alterations in the CD39/CD73 adenosinergic machinery and loss of function in ADA-deficient Tregs provide new insights into a predisposition to autoimmunity and the underlying mechanisms causing defective peripheral tolerance in ADA-SCID. Trials were registered at www.clinicaltrials.gov as NCT00598481/NCT00599781. PMID:22184407

  11. Impaired natriuretic response to high-NaCl diet plus aldosterone infusion in mice overexpressing human CD39, an ectonucleotidase (NTPDase1)

    PubMed Central

    Zhang, Yue; Robson, Simon C.; Morris, Kaiya L.; Heiney, Kristina M.; Dwyer, Karen M.; Ecelbarger, Carolyn M.

    2015-01-01

    Extracellular nucleotides acting through P2 receptors facilitate natriuresis. To define how purinergic mechanisms are involved in sodium homeostasis, we used transgenic (TG) mice that globally overexpress human CD39 (hCD39, NTPDase1), an ectonucleotidase that hydrolyzes extracellular ATP/ADP to AMP, resulting in an altered extracellular purine profile. On a high-sodium diet (HSD, 3.5% Na+), urine volume and serum sodium were significantly higher in TG mice but sodium excretion was unaltered. Furthermore, TG mice showed an attenuated fall in urine aldosterone with HSD. Western blot analysis revealed significantly lower densities (∼40%) of the β-subunit of the epithelial sodium channel (ENaC) in medulla, and the major band (85-kDa) of γ-ENaC in TG mice cortex. To evaluate aldosterone-independent differences, in a second experiment, aldosterone was clamped by osmotic minipump at 20 μg/day, and mice were fed either an HSD or a low-sodium diet (LSD, 0.03% Na+). Here, no differences in urine volume or osmolality, or serum aldosterone were found, but TG mice showed a modest, yet significant impairment in late natriuresis (days 3 and 4). Several major sodium transporters or channel subunits were differentially expressed between the genotypes. HSD caused a downregulation of Na-Cl cotransporter (NCC) in both genotypes; and had higher cortical levels of NCC, Na-K-ATPase (α-1 subunit), and α- and γ-ENaC. The Na-K-2Cl cotransporter (NKCC2) was downregulated by HSD in wild-type mice, but it increased in TG mice. In summary, our data support the concept that extracellular nucleotides facilitate natriuresis; they also reveal an aldosterone-independent downregulation of major renal sodium transporters and channel subunits by purinergic signaling. PMID:25877509

  12. Adenosine and the adenosine A2A receptor agonist, CGS21680, upregulate CD39 and CD73 expression through E2F-1 and CREB in regulatory T cells isolated from septic mice.

    PubMed

    Bao, Rui; Shui, Xianqi; Hou, Jiong; Li, Jinbao; Deng, Xiaoming; Zhu, Xiaoyan; Yang, Tao

    2016-09-01

    The number of regulatory T cells (Treg cells) and the expression of ectonucleoside triphosphate diphosphohydrolase 1 (ENTPD1; also known as CD39) and 5'-ectonucleotidase (NT5E; also known as CD73) on the Treg cell surface are increased during sepsis. In this study, to determine the factors leading to the high expression of CD39 and CD73, and the regulation of the CD39/CD73/adenosine pathway in Treg cells under septic conditions, we constructed a mouse model of sepsis and separated the Treg cells using a flow cytometer. The Treg cells isolated from the peritoneal lavage and splenocytes of the mice were treated with adenosine or the specific adenosine A2A receptor agonist, CGS21680, and were transfected with specific siRNA targeting E2F transcription factor 1 (E2F-1) or cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB), which are predicted transcription regulatory factors of CD39 or CD73. The regulatory relationships among these factors were then determined by western blot analysis and dual-luciferase reporter assay. In addition, changes in adenosine metabolism were measured in the treated cells. The results revealed that adenosine and CGS21680 significantly upregulated CD39 and CD73 expression (P<0.01). E2F-1 and CREB induced CD39 and CD73 expression, and were upregulated by adenosine and CGS21680. Adenosine triphosphate (ATP) hydrolysis and adenosine generation were inhibited by the knockdown of E2F-1 or CREB, and were accelerated in the presence of CGS21680. Based on these results, it can be inferred that adenosine, the adenosine A2A receptor agonist, E2F-1 and CREB are the possible factors contributing to the high expression of CD39 and CD73 on the Treg cell surface during sepsis. Adenosine and its A2A receptor agonist served as the signal transducer factors of the CD39/CD73/adenosine pathway, accelerating adenosine generation. Our study may benefit further research on adenosine metabolism for the treatment of sepsis

  13. The A-myb gene is preferentially expressed in tonsillar CD38+, CD39-, and sIgM- B lymphocytes and in Burkitt's lymphoma cell lines.

    PubMed

    Golay, J; Erba, E; Bernasconi, S; Peri, G; Introna, M

    1994-07-15

    The A-myb gene is structurally related to the c-mby proto-oncogene, a transcription factor involved in the regulation of hemopoietic proliferation and differentiation. Recent evidence has shown that A-myb also functions as a transcriptional activator. We have previously demonstrated that A-myb RNA is not expressed in most mature human leukocytes at rest or after mitogenic or functional activation. We show here, by using cell sorting, PCR, and Western analyses that A-myb is most highly expressed in the subsets of human tonsillar B lymphocytes with the phenotypes CD38+, CD39-, and SIgM-. The preferential expression of A-myb in these populations was seen at both the RNA and protein levels. CD38 was consistently best at separating high from low A-myb-expressing cells, whereas other markers (CD10, 22, 23, 77, 11a, and 49d) did not correlate with A-myb expression. The CD38+ population expressing the highest levels of A-myb was shown to contain mostly cycling cells inasmuch as more than 95% were in the late G1, S, G2, and M phases of the cell cycle. In addition, A-myb expression always correlated with the percentage of cells in S/G2/M in the populations sorted with either CD38, CD39, or sIgM. Small resting tonsillar B lymphocytes induced to proliferate in vitro by several different polyclonal B cell activators did not, however, express detectable levels of A-myb, although these cells were demonstrated to express CD38 and enter the S/G2/M phases of the cell cycle. These data suggest that A-myb is a marker of in vivo-activated but not in vitro-activated B lymphocytes. Finally, A-myb was also found to be highly expressed in five of seven Burkitt's lymphoma lines and in none of three EBV lymphoblastoid cell lines. This finding is in agreement with the phenotype of the normal B cells that express high levels of A-myb in vivo and suggests that A-myb may be specifically induced within germinal center B cells. PMID:8021494

  14. Milk-Based Nutraceutical for Treating Autoimmune Arthritis via the Stimulation of IL-10- and TGF-β-producing CD39+ Regulatory T Cells

    PubMed Central

    Maddaloni, Massimo; Kochetkova, Irina; Jun, SangMu; Callis, Gayle; Thornburg, Theresa; Pascual, David W.

    2015-01-01

    Autoimmune diseases arise from the loss of tolerance to self, and because the etiologies of such diseases are largely unknown, symptomatic treatments rely on anti-inflammatory and analgesic agents. Tolerogenic treatments that can reverse disease are preferred, but again, often thwarted by not knowing the responsible auto-antigens (auto-Ags). Hence, a viable alternative to stimulating regulatory T cells (Tregs) is to induce bystander tolerance. Colonization factor antigen I (CFA/I) has been shown to evoke bystander immunity and to hasten Ag-specific Treg development independent of auto-Ag. To translate in treating human autoimmune diseases, the food-based Lactococcus was engineered to express CFA/I fimbriae, and Lactococcus-CFA/I fermented milk fed to arthritic mice proved highly efficacious. Protection occurred via CD39+ Tregs producing TGF-β and IL-10 to potently suppress TNF-α production and neutrophil influx into the joints. Thus, these data demonstrate the feasibility of oral nutraceuticals for treating arthritis, and potency of protection against arthritis was improved relative to that obtained with Salmonella-CFA/I. PMID:25629976

  15. Particulate Matter

    MedlinePlus

    ... Technology Laws & Regulations About EPA Contact Us Particulate Matter (PM) You are here: EPA Home Air & Radiation Six Common Pollutants Particulate Matter Announcements March 13, 2013 - An updated “Strategies ...

  16. A CD38/CD203a/CD73 ectoenzymatic pathway independent of CD39 drives a novel adenosinergic loop in human T lymphocytes

    PubMed Central

    Horenstein, Alberto L; Chillemi, Antonella; Zaccarello, Gianluca; Bruzzone, Santina; Quarona, Valeria; Zito, Andrea; Serra, Sara; Malavasi, Fabio

    2013-01-01

    The tumor microenvironment is characterized by of high levels of extracellular nucleotides that are metabolized through the dynamic and sequential action of cell surface enzymes (ectoenzymes). These ectoenzymes operate according to their spatial arrangement, as part of (1) continuous (molecules on the same cell) or (2) discontinuous (molecules on different cells) pathways, the latter being facilitated by restricted cellular microenvironment. The outcome of this catabolic activity is an increase in the local concentration of adenosine, a nucleoside involved in the control of inflammation and immune responses. The aim of the work presented here was to demonstrate that a previously unexplored enzymatic pathway may be an alternate route to produce extracellular adenosine. Our data show that this new axis is driven by the nucleotide-metabolizing ectoenzymes CD38 (an NAD+ nucleosidase), the ecto-nucleotide pyrophosphatase/phosphodiesterase 1 (NPP1, also known as CD203a or PC-1) and the 5′ ectonucleotidase (5′-NT) CD73, while bypassing the canonical catabolic pathway mediated by the nucleoside tri- and diphosphohydrolase (NTPDase) CD39. To determine the relative contributions of these cell surface enzymes to the production of adenosine, we exploited a human T-cell model allowing for the modular expression of the individual components of this alternative pathway upon activation and transfection. The biochemical analysis of the products of these ectoenzymes by high-performance liquid chromatography (HPLC) fully substantiated our working hypothesis. This newly characterized pathway may facilitate the emergence of an adaptive immune response in selected cellular contexts. Considering the role for extracellular adenosine in the regulation of inflammation and immunogenicity, this pathway could constitute a novel strategy of tumor evasion, implying that these enzymes may represent ideal targets for antibody-mediated therapy. PMID:24319640

  17. South African Particulates

    Atmospheric Science Data Center

    2013-04-16

    ... title:  Airborne Particulates over Southern Africa     View Larger Image ... of airborne particulates, or aerosols, over Southern Africa during the period August 14 - September 29, 2000. Low particle ...

  18. Enrichment of Inflammatory IL-17 and TNF-α Secreting CD4+ T Cells within Colorectal Tumors despite the Presence of Elevated CD39+ T Regulatory Cells and Increased Expression of the Immune Checkpoint Molecule, PD-1

    PubMed Central

    Dunne, Margaret R.; Ryan, Ciara; Nolan, Bláthnaid; Tosetto, Miriam; Geraghty, Robert; Winter, Des C.; O’Connell, P. Ronan; Hyland, John M.; Doherty, Glen A.; Sheahan, Kieran; Ryan, Elizabeth J.; Fletcher, Jean M.

    2016-01-01

    T cell infiltration into colorectal tumors has been shown to correlate with improved patient outcomes. However, more detailed information on the makeup and relationships between the infiltrating T cell subsets is lacking. We therefore correlated the extent of immune infiltration into colorectal tumors with the frequencies of various T cell subsets. We prospectively recruited 22 patients at the time of surgical resection for colorectal cancer. The Klintrup–Mäkinen (KM) score was used to estimate the extent of immune infiltration into colorectal tumors. The frequencies of CD4 and CD8 T cells that produced cytokines or expressed the inhibitory molecule programed cell death 1 (PD-1) were determined by flow cytometry in colorectal tumor and matched uninvolved colonic tissue. In addition, the frequency of CD4 regulatory T cell (Treg) subsets was determined. An increased frequency of CD4 T cells producing IL-17 (Th17 cells) was observed in colorectal tumor tissue compared with adjacent uninvolved tissue. These Th17 cells mostly coproduced TNF-α, but not IFN-γ. IL-17 expression correlated positively with TNF-α and IL-10. Increased expression of the immune checkpoint molecule PD-1 was found in colorectal tumors compared with adjacent uninvolved tissue. There was a negative correlation between expression of PD-1 and IFN-γ, but not IL-17, for both CD4+ and CD8+ T cells. CD4+CD25+CD127lo and CD4+CD25+CD127loFoxP3+CD39+ Treg cells were enriched in colorectal tumors. A positive correlation between KM score and percentage CD4+CD25+CD127lo Treg cells was observed in tumors, suggesting that increased immune infiltration is associated with an increased proportion of Treg cells. In addition, there was a negative correlation between the frequency of CD4+CD25+CD127lo Treg cells and the expression of IFN-γ and IL-2, but not IL-17, in tumors. Taken together, these data suggest that both PD-1 expressing T cells and Treg cells within the tumor may have a suppressive effect on T

  19. Diesel particulate control

    SciTech Connect

    Bertelsen, F.I. )

    1988-01-01

    Diesel particulates, because of their chemical composition and extremely small size, have raised health and welfare issues. Health experts have expressed concern that they contribute to or aggravate chronic lung diseases such as asthma, bronchitis and emphysema, and there is the lingering issue about the potential cancer risk from exposure to diesel particulate. Diesel particulates impair visibility, soil buildings, contribute to structural damage through corrosion and give off a pungent odor. Diesel trucks, buses and cars together are such a significant and growing source of particulate emissions. Such vehicles emit 30 to 70 times more particulate matter than gasoline vehicles equipped with catalytic converters. Diesel engines currently power the majority of larger trucks and buses. EPA predicted that, if left uncontrolled, diesel particulate from motor vehicles would increase significantly. Diesel particulate emissions from motor vehicles are particularly troublesome because they frequently are emitted directly into the breathing zone where we work and recreate. The U.S. Congress recognized the risks posed by diesel particulate and as part of the 1977 Clean Air Act Amendments established specific, technology-forcing requirements for controlling these emissions. The U.S. Environmental Protection Agency (EPA) in 1980 established particulate standards for automobiles and light trucks and in 1985, heavy trucks and buses. California, concerned that EPA standards would not adequately protect its citizens, adopted its own set of standards for passenger cars and light trucks. This paper discusses emerging technologies proposed to address the problem.

  20. Particulate Air Pollution: The Particulars

    ERIC Educational Resources Information Center

    Murphy, James E.

    1973-01-01

    Describes some of the causes and consequences of particulate air pollution. Outlines the experimental procedures for measuring the amount of particulate materials that settles from the air and for observing the nature of particulate air pollution. (JR)

  1. Pitch based foam with particulate

    DOEpatents

    Klett, James W.

    2001-01-01

    A thermally conductive, pitch based foam composite having a particulate content. The particulate alters the mechanical characteristics of the foam without severely degrading the foam thermal conductivity. The composite is formed by mixing the particulate with pitch prior to foaming.

  2. CONTROLLING EMISSIONS OF PARTICULATES

    EPA Science Inventory

    The report gives a semi-technical overview of the contribution of particulate matter to the overall U.S. air pollution problem. It also discusses contributions of the Particulate Technology Branch of EPA's Industrial Environmental Research Laboratory at Research Triangle Park, N....

  3. Airborne particulate discriminator

    DOEpatents

    Creek, Kathryn Louise; Castro, Alonso; Gray, Perry Clayton

    2009-08-11

    A method and apparatus for rapid and accurate detection and discrimination of biological, radiological, and chemical particles in air. A suspect aerosol of the target particulates is treated with a taggant aerosol of ultrafine particulates. Coagulation of the taggant and target particles causes a change in fluorescent properties of the cloud, providing an indication of the presence of the target.

  4. Fluidizing device for solid particulates

    DOEpatents

    Diebold, J.P.; Scahill, J.W.

    A flexible whip suspended in a hopper is caused to impact against fibrous and irregularly shaped particulates in the hopper to fluidize the particulates and facilitate the flow of the particulates through the hopper. The invention provides for the flow of particulates at a substantially constant mass flow rate and uses a minimum of energy.

  5. Diesel particulate emissions

    SciTech Connect

    Williams, P.T.; Abbass, M.K.; Andrews, G.E.; Bartle, K.D.

    1989-01-01

    The relationship between diesel fuel composition and that of the solvent organic fraction of diesel particulates was investigated for an old DI Petter engine and a modern DI Perkins engine. Polycyclic aromatic compounds (PAC) were identified using high-resolution capillary column chromatography with a parallel triple detector system for polycyclic aromatic hydrocarbons (PAH), nitrogen-containing PAH, and sulphur-containing PAH. Identification of the PAC using retention indexes was confirmed using an ion trap detector, which was also used to quantify the low-concentration (<1 ppm) benzo(a)pyrene. It was conclusively shown for both engines that the bulk of the particulate solvent organic fraction, including the PAH fraction, was unburned fuel. However, there was some evidence that high molecular weight five-ring PAH may have an in-cylinder formation contribution, and it is postulated that this could be due to pyrolysis of lower molecular weight unburned fuel PAH. The contribution of lubricating oil to the particulate PAC is discussed, and evidence is presented that shows the unburned fuel PAC accumulates in the lubricating oil and thus contributes to the particulate PAC via the large lubricating oil component of the particulate PAC.

  6. ADVANCED HYBRID PARTICULATE COLLECTOR

    SciTech Connect

    Stanley Miller; Rich Gebert; William Swanson

    1999-11-01

    A new concept in particulate control, called an advanced hybrid particulate collector (AHPC), is being developed under funding from the US Department of Energy. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a manner that has not been done before. The AHPC concept consists of a combination of fabric filtration and electrostatic precipitation in the same housing, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emission with conventional ESPs, and it solves the problem of reentrainment and collection of dust in conventional baghouses. The AHPC is currently being tested at the 2.7-MW scale at the Big Stone power station.

  7. Void/particulate detector

    DOEpatents

    Claytor, Thomas N.; Karplus, Henry B.

    1985-01-01

    Voids and particulates are detected in a flowing stream of fluid contained in a pipe by a detector which includes three transducers spaced about the pipe. A first transducer at a first location on the pipe transmits an ultrasonic signal into the stream. A second transducer detects the through-transmission of the signal at a second location and a third transducer at a third location upstream from the first location detects the back-scattering of the signal from any voids or particulates. To differentiate between voids and particulates a fourth transducer is positioned at a fourth location which is also upstream from the first location. The back-scattered signals are normalized with the through-transmission signal to minimize temperature fluctuations.

  8. Microwave regenerated particulate trap

    SciTech Connect

    McDonald, A.C. Jr.; Yonushonis, T.M.; Haberkamp, W.C.; Mako, F.; Len, L.K,; Silberglitt, R.; Ahmed, I.

    1997-12-31

    It has been demonstrated that a fibrous particulate filter can extract particulate matter from the diesel exhaust. However, additional engineering efforts remains to achieve the design target of 90%. It has also be shown that with minor modifications magnetrons produced for home ovens can endure a simulated diesel operating environment. Much work remains to develop a robust product ready to complete extensive engine testing and evaluation. These efforts include: (1) additional environmental testing of magnetrons; (2) vibration testing of the filter in the housing; (3) evaluating alternative methods/designs to seal the center bore; and (4) determining the optimum coating thickness that provides sufficient structural integrity while maintaining rapid heating rates.

  9. Fluidizing device for solid particulates

    DOEpatents

    Diebold, J.P.; Scahill, J.W.

    1984-06-27

    A flexible whip or a system of whips with novel attachments is suspended in a hopper and is caused to impact against fibrous and irregularly shaped particulates in the hopper to fluidize the particulates and facilitate the flow of the particulates through the hopper. The invention provides for the flow of particulates at a substantially constant mass flow rate and uses a minimum of energy.

  10. Fluidizing device for solid particulates

    DOEpatents

    Diebold, James P.; Scahill, John W.

    1986-01-01

    A flexible whip or a system of whips with novel attachments is suspended in a hopper and is caused to impact against fibrous and irregularly shaped particulates in the hopper to fluidize the particulates and facilitate the flow of the particulates through the hopper. The invention provides for the flow of particulates at a substantially constant mass flow rate and uses a minimum of energy.

  11. PARTICULATE EMISSION CONTROL

    EPA Science Inventory

    Particle or particulate matter is defined as any finely divided solid or liquid material, other than uncombined water, emitted to the ambient air as measured by applicable reference methods, or an equivalent or alternative method, or by a test method specified in 40CFR50.

  12. Rigid particulate matter sensor

    DOEpatents

    Hall, Matthew

    2011-02-22

    A sensor to detect particulate matter. The sensor includes a first rigid tube, a second rigid tube, a detection surface electrode, and a bias surface electrode. The second rigid tube is mounted substantially parallel to the first rigid tube. The detection surface electrode is disposed on an outer surface of the first rigid tube. The detection surface electrode is disposed to face the second rigid tube. The bias surface electrode is disposed on an outer surface of the second rigid tube. The bias surface electrode is disposed to face the detection surface electrode on the first rigid tube. An air gap exists between the detection surface electrode and the bias surface electrode to allow particulate matter within an exhaust stream to flow between the detection and bias surface electrodes.

  13. Void/particulate detector

    DOEpatents

    Claytor, T.N.; Karplus, H.B.

    1983-09-26

    Apparatus for detecting voids and particulates in a flowing stream of fluid contained in a pipe may comprise: (a) a transducer for transmitting an ultrasonic signal into the stream, coupled to the pipe at a first location; (b) a second transducer for detecting the through-transmission of said signal, coupled to the pipe at a second location; (c) a third transducer for detecting the back-scattering of said signal, coupled to the pipe at a third location, said third location being upstream from said first location; (d) circuit means for normalizing the back-scattered signal from said third transducer to the through-transmitted signal from said second transducer; which normalized signal provides a measure of the voids and particulates flowing past said first location.

  14. Regenerable particulate filter

    DOEpatents

    Stuecker, John N.; Cesarano, III, Joseph; Miller, James E.

    2009-05-05

    A method of making a three-dimensional lattice structure, such as a filter used to remove particulates from a gas stream, where the physical lattice structure is designed utilizing software simulation from pre-defined mass transfer and flow characteristics and the designed lattice structure is fabricated using a free-form fabrication manufacturing technique, where the periodic lattice structure is comprised of individual geometric elements.

  15. Eighth particulate control symposium

    SciTech Connect

    Not Available

    1990-11-01

    The Eighth Symposium on the Transfer and Utilization of Particulate Control Technology was held in San Diego, California, March 20 through 23, 1990. The symposium proceedings contain 80 papers presented by representatives of utility companies, equipment and process suppliers, university representatives, research and development companies, EPA and other federal and state agency representatives, and EPRI staff members. Electrostatic precipitators and fabric filters were the major topics discussed during the symposium. Papers from this conference are organized by session in two volumes. This Volume (2) contains papers presented in the sessions on: low ratio baghouse O M experience, pulse-jet baghouse experience, particulate control for AFBCs, particulate control for dry SO2 control processes, baghouse design and performance, fundamental baghouse studies, high temperature filtration, and control of emissions from RDF incinerators. Both fabric filters and ESPs are discussed in the AFBC and dry SO2 control papers. The high temperature filtration papers deal with ceramic barrier and granular bed filters. The rest of the papers in Volume 2 are concerned with fabric filters on pulverized-coal-fired boilers. Individual projects are processed separately for the data bases.

  16. ADVANCED HYBRID PARTICULATE COLLECTOR

    SciTech Connect

    Stanley J. Miller; Grant L. Schelkoph; Grant E. Dunham

    2000-12-01

    A new concept in particulate control, called an advanced hybrid particulate collector (AHPC), is being developed under funding from the US Department of Energy. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in an entirely novel manner. The AHPC concept combines fabric filtration and electrostatic precipitation in the same housing, providing major synergism between the two methods, both in the particulate collection step and in transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and solves the problem of reentrainment and recollection of dust in conventional baghouses. Phase I of the development effort consisted of design, construction, and testing of a 5.7-m{sup 3}/min (200-acfm) working AHPC model. Results from both 8-hour parametric tests and 100-hour proof-of-concept tests with two different coals demonstrated excellent operability and greater than 99.99% fine-particle collection efficiency.

  17. Diesel particulate emissions

    SciTech Connect

    Abbass, M.K.; Andrews, G.E.; Williams, P.T.; Bartle, K.D.; Davies, I.L.; Tanui, L.K.

    1988-01-01

    The objective was to investigate combustion generated PAH in Diesel engine particulate emissions using a pure single component fuel, hexadecane, in a Perkins 4-236 engine in a single cylinder format. The results were compared with those using a conventional Diesel fuel and with the particulates collected by motoring the engine. To minimise any influence of contamination from the PAH in used lubricating oil, all the tests were carried out with fresh PAH free lubricating oil. The hexadecane particulates were found to contain 6-25% of the PAH and 5-9% of the n-alkanes for Diesel and the motoring tests were found to give 10% of the PAH and 50-200% of the n-alkane for hexadecane. It was concluded that there was an internal source of n-alkane and PAH in the engine and exhaust system, probably absorbed in engine deposits. It was therefore not possible to conclude that the PAH with hexadecane was pyrosynthesised.

  18. Airborne Particulate Threat Assessment

    SciTech Connect

    Patrick Treado; Oksana Klueva; Jeffrey Beckstead

    2008-12-31

    Aerosol threat detection requires the ability to discern between threat agents and ambient background particulate matter (PM) encountered in the environment. To date, Raman imaging technology has been demonstrated as an effective strategy for the assessment of threat agents in the presence of specific, complex backgrounds. Expanding our understanding of the composition of ambient particulate matter background will improve the overall performance of Raman Chemical Imaging (RCI) detection strategies for the autonomous detection of airborne chemical and biological hazards. Improving RCI detection performance is strategic due to its potential to become a widely exploited detection approach by several U.S. government agencies. To improve the understanding of the ambient PM background with subsequent improvement in Raman threat detection capability, ChemImage undertook the Airborne Particulate Threat Assessment (APTA) Project in 2005-2008 through a collaborative effort with the National Energy Technology Laboratory (NETL), under cooperative agreement number DE-FC26-05NT42594. During Phase 1 of the program, a novel PM classification based on molecular composition was developed based on a comprehensive review of the scientific literature. In addition, testing protocols were developed for ambient PM characterization. A signature database was developed based on a variety of microanalytical techniques, including scanning electron microscopy, FT-IR microspectroscopy, optical microscopy, fluorescence and Raman chemical imaging techniques. An automated particle integrated collector and detector (APICD) prototype was developed for automated collection, deposition and detection of biothreat agents in background PM. During Phase 2 of the program, ChemImage continued to refine the understanding of ambient background composition. Additionally, ChemImage enhanced the APICD to provide improved autonomy, sensitivity and specificity. Deliverables included a Final Report detailing our

  19. Particulate contamination in ampoules.

    PubMed

    Alexander, D M; Veltman, A M

    1985-01-01

    The particulate contamination in 19 formulations of solutions in ampoules supplied by eight South African manufacturers, thirty-three batches in all, was analysed using a HIAC PC 320 light blockage particle analyser linked to a CMB 60 sensor. Results showed that the level of contamination was generally low and that, where comparisons could be made, manufacturers both of the ampoules and the solutions maintained similarly high standards. Problems in this field appeared to be related to the formulation or the quality of the raw material. PMID:2858528

  20. Apparatus for particulate matter analysis

    DOEpatents

    Gundel, Lara A.; Apte, Michael G.; Hansen, Anthony D.; Black, Douglas R.

    2007-01-30

    The apparatus described herein is a miniaturized system for particle exposure assessment (MSPEA) for the quantitative measurement and qualitative identification of particulate content in gases. The present invention utilizes a quartz crystal microbalance (QCM) or other mass-sensitive temperature compensated acoustic wave resonator for mass measurement. Detectors and probes and light sources are used in combination for the qualitative determination of particulate matter.

  1. PARTICULATE CONTROL FOR FUGITIVE DUST

    EPA Science Inventory

    The report gives results of a study of particulate control for fugitive dust. Study results indicate that many Air Quality Control Regions (AQCRs) do not meet ambient air standards for particulates. In a majority of these ACQRs, the emissions from fugitive dust sources are higher...

  2. Diesel particulate trap mounting system

    SciTech Connect

    Miller, P.R.

    1992-01-21

    This patent describes a particulate trap assembly. It comprises an outer housing having a gas inlet and a gas outlet and a passageway interconnecting the gas inlet and the gas outlet; a particulate trapping means located within the passageway of the housing for trapping particles entrained in gas passing through the passageway, the passageway and the particulate trapping means having circumferential extents which fall within relatively large predetermined manufacturing tolerances respectively; tourniquet means surrounding the particulate trapping means for applying a predetermined radial pressure to the trapping means which is substantially independent of the circumferential extents of the passageway and the including an encircling element having a selectably adjustable circumferential extent for permitting the tourniquet means to conform to the circumferential extent of the particulate trapping means when mounted in compressive relationship about the particulate trapping means, and mounting means for retaining the particulate trapping means radially and axially within the passageway in a manner which imposes no further substantial radial compressive force to the particulate trapping means.

  3. Particulate erosion mechanisms

    NASA Technical Reports Server (NTRS)

    Veerabhadrarao, P.; Buckley, D. H.

    1983-01-01

    Particulate damage and erosion of ductile metals are today plaguing design and field engineers in diverse fields of engineering and technology. It was found that too many models and theories were proposed leading to much speculation from debris analysis and failure mechanism postulations. Most theories of solid particle erosion are based on material removal models which do not fully represent the actual physical processes of material removal. The various mechanisms proposed thus far are: melting, low-cycle fatigue, extrusion, delamination, shear localization, adhesive material transfer, etc. The experimental data on different materials highlighting the observed failure modes of the deformation and cutting wear processes using optical and scanning electron microscopy are presented. The most important mechanisms proved from the experimental observations of the specimens exposed to both spherical and angular particles are addressed, and the validity of the earlier theories discussed. Both the initial stages of damage and advanced stages of erosion were studied to gain a fundamental understanding of the process.

  4. Spacecraft particulate sizing spectrometer

    NASA Technical Reports Server (NTRS)

    Miranda, Henry A., Jr.

    1992-01-01

    An evaluation prototype device is described, together with conclusions and several recommendations for follow-on flight hardware. The device detects individual particles crossing an external sensing zone, and produces a histogram displaying the size distribution of particles sensed, over the nominal range of 5 to 50 microns. The output is totally independent of the particle refractive index, and is also largely unaffected by particle shape. The reported diameters are in terms of the equivalent sphere, as judged by the scattered light intercepted by the receiving channels, which develop signals whenever a particle crosses the beam of illumination in the sensing zone. Supporting evidence for the latter assertion is discussed on the basis of experimental test data for non-spherical particulates. Also included is a technical appendix which presents theoretical arguments that provide a firm foundation for this assertion.

  5. Micromechanics for particulate reinforced composites

    NASA Technical Reports Server (NTRS)

    Murthy, Pappu L. N.; Goldberg, Robert K.; Mital, Subodh K.

    1996-01-01

    A set of micromechanics equations for the analysis of particulate reinforced composites is developed using the mechanics of materials approach. Simplified equations are used to compute homogenized or equivalent thermal and mechanical properties of particulate reinforced composites in terms of the properties of the constituent materials. The microstress equations are also presented here to decompose the applied stresses on the overall composite to the microstresses in the constituent materials. The properties of a 'generic' particulate composite as well as those of a particle reinforced metal matrix composite are predicted and compared with other theories as well as some experimental data. The micromechanics predictions are in excellent agreement with the measured values.

  6. ADVANCED HYBRID PARTICULATE COLLECTOR

    SciTech Connect

    Ye Zhuang; Stanley J. Miller; Michelle R. Olderbak; Rich Gebert

    2001-12-01

    A new concept in particulate control, called an advanced hybrid particulate collector (AHPC), is being developed under funding from the U.S. Department of Energy. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in an entirely novel manner. The AHPC concept combines fabric filtration and electrostatic precipitation in the same housing, providing major synergism between the two methods, both in the particulate collection step and in transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and solves the problem of reentrainment and re-collection of dust in conventional baghouses. Phase I of the development effort consisted of design, construction, and testing of a 5.7-m{sup 3}/min (200-acfm) working AHPC model. Results from both 8-hr parametric tests and 100-hr proof-of-concept tests with two different coals demonstrated excellent operability and greater than 99.99% fine-particle collection efficiency. Since all of the developmental goals of Phase I were met, the approach was scaled up in Phase II to a size of 255 m{sup 3}/min (9000 acfm) (equivalent in size to 2.5 MW) and was installed on a slipstream at the Big Stone Power Plant. For Phase II, the AHPC at Big Stone Power Plant was operated continuously from late July 1999 until mid-December 1999. The Phase II results were highly successful in that ultrahigh particle collection efficiency was achieved, pressure drop was well controlled, and system operability was excellent. For Phase III, the AHPC was modified into a more compact configuration, and components were installed that were closer to what would be used in a full-scale commercial design. The modified AHPC was operated from April to July 2000. While operational results were acceptable during this time, inspection of bags in the summer of 2000 revealed some membrane damage to the fabric that appeared to be

  7. Electrically heated particulate filter restart strategy

    DOEpatents

    Gonze, Eugene V [Pinckney, MI; Ament, Frank [Troy, MI

    2011-07-12

    A control system that controls regeneration of a particulate filter is provided. The system generally includes a propagation module that estimates a propagation status of combustion of particulate matter in the particulate filter. A regeneration module controls current to the particulate filter to re-initiate regeneration based on the propagation status.

  8. A Course in Particulate Processes.

    ERIC Educational Resources Information Center

    Randolph, Alan D.

    1989-01-01

    Provides an overview of a graduate course on particulate processes, especially on crystal size distribution (CSD). Describes the course and includes a list of course topics. Discusses the CSD simulation and manipulation. (YP)

  9. Measurement of vehicle particulate emissions.

    PubMed Central

    Beltzer, M

    1975-01-01

    A constant volume sampler (CVS) compatible auto exhaust particulate sampling system has been built which samples exhaust isokinetically at constant temperature. This system yields internally consistent results and is capable of frequent and convenient operation. PMID:50931

  10. Electrical diesel particulate filter (DPF) regeneration

    DOEpatents

    Gonze, Eugene V; Ament, Frank

    2013-12-31

    An exhaust system that processes exhaust generated by an engine includes a diesel particulate filter (DPF) that is disposed downstream of the engine and that filters particulates from the exhaust. An electrical heater is disposed upstream of the DPF and selectively heats the exhaust to initiate combustion of the particulates within the exhaust as it passes therethrough. Heat generated by combustion of the particulates induces combustion of particulates within the DPF.

  11. Hydrocarbon-enhanced particulate filter regeneration via microwave ignition

    DOEpatents

    Gonze, Eugene V.; Brown, David B.

    2010-02-02

    A regeneration method for a particulate filter includes estimating a quantity of particulate matter trapped within the particulate filter, comparing the quantity of particulate matter to a predetermined quantity, heating at least a portion of the particulate filter to a combustion temperature of the particulate matter, and introducing hydrocarbon fuel to the particulate filter. The hydrocarbon fuel facilitates combustion of the particulate matter to regenerate the particulate filter.

  12. ITP Filter Particulate Decontamination Measurement

    SciTech Connect

    Dworjanyn, L.O.

    1993-05-21

    A new test method was developed which showed the installed In- Tank Precipitation Filter Unit {number_sign}3 provided at least 40, 000 x decontamination of the precipitated potassium tetraphenylborate (KTPB) during the cold chemical runs.This filter is expected to meet the needed 40,000 x hot cesium decontamination requirements, assuming that the cesium precipitate, CsTPB, behaves the same as KTPB. The new method permits cold chemicals field testing of installed filters to quantify particulate decontamination and verify filter integrity before going hot. The method involves a 1000 x concentration of fine particulate KTPB in the filtrate to allow direct analysis by counting for naturally radioactive isotope K-40 using the underground SRTC gamma spectroscopy facility. The particulate concentration was accomplished by ultra filtration at Rhone-Poulenc, NJ, using a small cross-flow bench facility, followed by collection of all suspended solids on a small filter disc for K analysis.

  13. PARTICULATE EMISSION MEASUREMENTS FROM CONTROLLED CONSTRUCTION ACTIVITIES

    EPA Science Inventory

    The report summarized the results of field testing of the effectiveness of control measures for sources of fugitive particulate emissions found at construction sites. The effectiveness of watering temporary, unpaved travel surfaces on emissions of particulate matter with aerodyna...

  14. NONFERROUS INDUSTRY PARTICULATE EMISSIONS: SOURCE CATEGORY REPORT

    EPA Science Inventory

    The report gives results of the development of particulate emission factors based on cutoff size for inhalable particles for the nonferrous industry. After a review of available information characterizing particulate emissions from nonferrous plants, the data were summarized and ...

  15. PAVED ROAD PARTICULATE EMISSIONS: SOURCE CATEGORY REPORT

    EPA Science Inventory

    The report gives results of extensive field tests to develop emission factors for particulate emissions generated by traffic entrainment of paved road surface particulate matter. Using roadway surface silt loading as the basis, predictive emission factor equations for each partic...

  16. EXTERNAL COMBUSTION PARTICULATE EMISSIONS: SOURCE CATEGORY REPORT

    EPA Science Inventory

    The report gives results of the development of particulate emission factors based on cutoff size for inhalable particles for external combustion sources. After a review of available information characterizing particulate emissions from external combustion sources, the data were s...

  17. Process for particulate removal from coal liquids

    DOEpatents

    Rappe, Gerald C.

    1983-01-01

    Suspended solid particulates are removed from liquefied coal products by first subjecting such products to hydroclone action for removal in the underflow of the larger size particulates, and then subjecting the overflow from said hydroclone action, comprising the residual finer particulates, to an electrostatic field in an electrofilter wherein such finer particulates are deposited in the bed of beads of dielectric material on said filter. The beads are periodically cleaned by backwashing to remove the accumulated solids.

  18. Particulate matter and preterm birth

    EPA Science Inventory

    Particulate matter (PM) has been variably associated with preterm birth (PTB) (gestation <37 weeks), but the role played by specific chemical components of PM has been little studied. We examined the association between ambient PM <2.5 micrometers in aerodynamic diameter (PM2.S) ...

  19. Source Testing for Particulate Matter.

    ERIC Educational Resources Information Center

    DeVorkin, Howard

    Developed for presentation at the 12th Conference on Methods in Air Pollution and Industrial Hygiene Studies, University of Southern California, April, 1971, this outline covers procedures for the testing of particulate matter. These are: (1) basic requirements, (2) information required, (3) collection of samples, (4) processing of samples, (5)…

  20. MODELING PARTICULATE CHARGING IN ESPS

    EPA Science Inventory

    In electrostatic precipitators there is a strong interaction between the particulate space charge and the operating voltage and current of an electrical section. Calculating either the space charge or the operating point when the other is fixed is not difficult, but calculating b...

  1. Regional Background Fine Particulate Matter

    EPA Science Inventory

    A modeling system composed of the global model GEOS-Chem providing hourly lateral boundary conditions to the regional model CMAQ was used to calculate the policy relevant background level of fine particulate: matter. Simulations were performed for the full year of 2004 over the d...

  2. Particulate emissions from concentrated animal feeding operations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Concentrated animal feeding operations (CAFOs), including open beef cattle feedlots, swine facilities, and poultry facilities, can emit large amounts of particulate matter, including TSP (total suspended particulates), PM10 (particulate matter with equivalent aerodynamic diameter of 10 mm or less) a...

  3. Influence of Ecto-Nucleoside Triphosphate Diphosphohydrolase Activity on Trypanosoma cruzi Infectivity and Virulence

    PubMed Central

    Santos, Ramon F.; Pôssa, Marcela A. S.; Bastos, Matheus S.; Guedes, Paulo M. M.; Almeida, Márcia R.; DeMarco, Ricardo; Verjovski-Almeida, Sergio; Bahia, Maria T.; Fietto, Juliana L. R.

    2009-01-01

    Background The protozoan Trypanosoma cruzi is the causative agent of Chagas disease. There are no vaccines or effective treatment, especially in the chronic phase when most patients are diagnosed. There is a clear necessity to develop new drugs and strategies for the control and treatment of Chagas disease. Recent papers have suggested the ecto-nucleotidases (from CD39 family) from pathogenic agents as important virulence factors. In this study we evaluated the influence of Ecto-Nucleoside-Triphosphate-Diphosphohydrolase (Ecto-NTPDase) activity on infectivity and virulence of T. cruzi using both in vivo and in vitro models. Methodology/Principal Findings We followed Ecto-NTPDase activities of Y strain infective forms (trypomastigotes) obtained during sequential sub-cultivation in mammalian cells. ATPase/ADPase activity ratios of cell-derived trypomastigotes decreased 3- to 6-fold and infectivity was substantially reduced during sequential sub-cultivation. Surprisingly, at third to fourth passages most of the cell-derived trypomastigotes could not penetrate mammalian cells and had differentiated into amastigote-like parasites that exhibited 3- to 4-fold lower levels of Ecto-NTPDase activities. To evidence the participation of T. cruzi Ecto-NTPDase1 in the infective process, we evaluated the effect of known Ecto-ATPDase inhibitors (ARL 67156, Gadolinium and Suramin), or anti-NTPDase-1 polyclonal antiserum on ATPase and ADPase hydrolytic activities in recombinant T. cruzi NTPDase-1 and in live trypomastigotes. All tests showed a partial inhibition of Ecto-ATPDase activities and a marked inhibition of trypomastigotes infectivity. Mice infections with Ecto-NTPDase-inhibited trypomastigotes produced lower levels of parasitemia and higher host survival than with non-inhibited control parasites. Conclusions/Significance Our results suggest that Ecto-ATPDases act as facilitators of infection and virulence in vitro and in vivo and emerge as target candidates in chemotherapy

  4. Thiazolo[3,2-a]benzimidazol-3(2H)-one derivatives: Structure-activity relationships of selective nucleotide pyrophosphatase/phosphodiesterase1 (NPP1) inhibitors.

    PubMed

    Lee, Sang-Yong; Perotti, Arianna; De Jonghe, Steven; Herdewijn, Piet; Hanck, Theodor; Müller, Christa E

    2016-07-15

    Ecto-nucleotide pyrophosphatase/phosphodiesterase1 (NPP1) is the most important member of the NPP family, which consists of seven closely related proteins (NPP1-NPP7). This glycoprotein is a membrane-associated or secreted enzyme, which catalyzes the hydrolysis of a wide range of phosphodiester bonds, e.g., in nucleoside triphosphates, dinucleotides and nucleotide sugars. NPP1 plays a crucial role in various physiological functions including bone mineralization, soft-tissue calcification, and insulin receptor signaling. Recently, an upregulated expression of NPP1 has been observed in astrocytic brain cancers. Therefore, NPP1 has been proposed as a novel drug target for the treatment of glioblastoma. Despite their therapeutic potential, only few NPP1 inhibitors have been reported to date, which are in most cases non- or only moderately selective. The best investigated NPP1 inhibitors so far are nucleotide derivatives and analogs, however they are not orally bioavailable due to their high polarity. We identified thiazolo[3,2-a]benzimidazol-3(2H)-one derivatives as a new class of NPP1 inhibitors with drug-like properties. Among the 25 derivatives investigated in the present study, 2-[(5-iodo-2-furanyl)methylene]thiazolo[3,2-a]benzimidazol-3(2H)-one (17) was found to be the most potent NPP1 inhibitor with a Ki value of 467nM versus ATP as a substrate and an un-competitive mechanism of inhibition. Compound 17 did not inhibit other human ecto-nucleotidases, including NTPDase1 (CD39), NTPDases2-3, NPP2, NPP3, tissue-nonspecific alkaline phosphatase (TNAP), and ecto-5'-nucleotidase (eN, CD73), and is thus highly selective for NPP1. PMID:27265686

  5. Downregulation of CD73 in 4T1 breast cancer cells through siRNA-loaded chitosan-lactate nanoparticles.

    PubMed

    Jadidi-Niaragh, Farhad; Atyabi, Fatemeh; Rastegari, Ali; Mollarazi, Esmail; Kiani, Melika; Razavi, Alireza; Yousefi, Mehdi; Kheshtchin, Nasim; Hassannia, Hadi; Hadjati, Jamshid; Shokri, Fazel

    2016-06-01

    The immunosuppressive factors in tumor microenvironment enhance tumor growth and suppress anti-tumor immune responses. Adenosine is an important immunosuppressive factor which can be secreted by both tumor and immune cells trough action of two cell surface ecto-nucleotidase molecules CD39 and CD73. Blocking the adenosine generating molecules has emerged as an effective immunotherapeutic approach for treatment of cancer. In this study, CD73-siRNA encapsulated into chitosan-lactate (ChLa) nanoparticles (NPs) was employed to suppress the expression of CD73 molecule on 4T1 breast tumor cells, in vitro. ChLa NPs were generated through ionic gelation of ChLa by tripolyphosphate (TPP). Small interfering RNA (SiRNA)-loaded NPs had about 100 nm size with a polydispersive index below 0.3 and a zeta potential about 13. Our results showed that ChLa NPs with Ch 50 kDa exhibit the best physicochemical features with the high siRNA encapsulation capacity. Synthesized NPs were able to fully bind with siRNA, protect them against serum and heparin degradation, and promote the transfection process. While the NPs exhibited low toxicity during 72 h cell culture, the transfection of Ch-plasmid expressing green fluorescent protein (pEGFP) NPs was efficient in 4T1 cells with a transfection rate of 53.6 % as detected by flow cytometry. In addition, CD73-siRNA-loaded ChLa NPs could efficiently suppress the expression of CD73 as assayed by real-time polymerase chain reaction and flow cytometry. As a conclusion, CD73-siRNA-loaded ChLa NPs may be considered as a promising therapeutic tool for cancer therapy; however, further in vivo investigations are necessary. PMID:26733167

  6. Polymer Particulates in Drug Delivery.

    PubMed

    Kaur, Harmeet; Kumar, Virender; Kumar, Krishan; Rathor, Sandeep; Kumari, Parveen; Singh, Jasbir

    2016-01-01

    Development of effective drug delivery systems is important for medicine and healthcare. Polymer particulates (micro- and nanoparticles) have opened new opportunities in the field of drug delivery by overcoming various limitations of conventional delivery methods. The properties of polymeric particles can be readily tuned by precisely engineering the constituent blocks of polymers for improving drug loading, release rate, pharmacokinetics, targeting, etc. The end-groups of various polymers can be readily modified with ligands making them suitable for recognizing by cell-specific receptors, providing cellular specificity, and superior intracellular delivery. This review will mainly cover delivery of many potential drugs and biomolecules by means of polymeric microparticles, nanoparticles and copolymer micelles or assemblies. An overview about formulation methods of polymer particulates has also been addressed. Attempt has been made to cover all the potential polymers that are well known in pharmaceutical history. PMID:26898740

  7. Polarization signatures of airborne particulates

    NASA Astrophysics Data System (ADS)

    Raman, Prashant; Fuller, Kirk A.; Gregory, Don A.

    2013-07-01

    Exploratory research has been conducted with the aim of completely determining the polarization signatures of selected particulates as a function of wavelength. This may lead to a better understanding of the interaction between electromagnetic radiation and such materials, perhaps leading to the point detection of bio-aerosols present in the atmosphere. To this end, a polarimeter capable of measuring the complete Mueller matrix of highly scattering samples in transmission and reflection (with good spectral resolution from 300 to 1100 nm) has been developed. The polarization properties of Bacillus subtilis (surrogate for anthrax spore) are compared to ambient particulate matter species such as pollen, dust, and soot. Differentiating features in the polarization signatures of these samples have been identified, thus demonstrating the potential applicability of this technique for the detection of bio-aerosol in the ambient atmosphere.

  8. Quasicrystalline particulate reinforced aluminum composite

    SciTech Connect

    Anderson, I.E.; Biner, S.B.; Sordelet, D.J.; Unal, O.

    1997-07-01

    Particulate reinforced aluminum and aluminum alloy composites are rapidly emerging as new commercial materials for aerospace, automotive, electronic packaging and other high performance applications. However, their low processing ductility and difficulty in recyclability have been the key concern. In this study, two composite systems having the same aluminum alloy matrix, one reinforced with quasicrystals and the other reinforced with the conventional SiC reinforcements were produced with identical processing routes. Their processing characteristics and tensile mechanical properties were compared.

  9. Material Instabilities in Particulate Systems

    NASA Technical Reports Server (NTRS)

    Goddard, J. D.

    1999-01-01

    Following is a brief summary of a theoretical investigation of material (or constitutive) instability associated with shear induced particle migration in dense particulate suspensions or granular media. It is shown that one can obtain a fairly general linear-stability analysis, including the effects of shear-induced anisotropy in the base flow as well as Reynolds dilatancy. A criterion is presented here for simple shearing instability in the absence of inertia and dilatancy.

  10. Zone heated diesel particulate filter electrical connection

    DOEpatents

    Gonze, Eugene V.; Paratore, Jr., Michael J.

    2010-03-30

    An electrical connection system for a particulate filter is provided. The system includes: a particulate filter (PF) disposed within an outer shell wherein the PF is segmented into a plurality of heating zones; an outer mat disposed between the particulate filter and the outer shell; an electrical connector coupled to the outer shell of the PF; and a plurality of printed circuit connections that extend along the outer surface of the PF from the electrical connector to the plurality of heating zones.

  11. Diesel particulate filter with zoned resistive heater

    DOEpatents

    Gonze, Eugene V [Pinckney, MI

    2011-03-08

    A diesel particulate filter assembly comprises a diesel particulate filter (DPF) and a heater assembly. The DPF filters a particulate from exhaust produced by an engine. The heater assembly has a first metallic layer that is applied to the DPF, a resistive layer that is applied to the first metallic layer, and a second metallic layer that is applied to the resistive layer. The second metallic layer is etched to form a plurality of zones.

  12. Powder and particulate production of metallic alloys

    NASA Technical Reports Server (NTRS)

    Grant, N. J.

    1982-01-01

    Developments of particulate metallurgy of alloyed materials where the final products is a fully dense body are discussed. Particulates are defined as powders, flakes, foils, silvers, ribbons and strip. Because rapid solidification is an important factor in particulate metallurgy, all of the particulates must have at least one dimension which is very fine, sometimes as fine as 10 to 50 microns, but move typically up to several hundred microns, provided that the dimension permits a minimum solidification rate of at least 100 K/s.

  13. Electrically heated particulate filter embedded heater design

    SciTech Connect

    Gonze, Eugene V.; Chapman, Mark R.

    2014-07-01

    An exhaust system that processes exhaust generated by an engine is provided. The system generally includes a particulate filter (PF) that filters particulates from the exhaust wherein an upstream end of the PF receives exhaust from the engine and wherein an upstream surface of the particulate filter includes machined grooves. A grid of electrically resistive material is inserted into the machined grooves of the exterior upstream surface of the PF and selectively heats exhaust passing through the grid to initiate combustion of particulates within the PF.

  14. Electrically heated particulate filter using catalyst striping

    SciTech Connect

    Gonze, Eugene V; Paratore, Jr., Michael J; Ament, Frank

    2013-07-16

    An exhaust system that processes exhaust generated by an engine is provided. The system generally includes a particulate filter (PF) that filters particulates from the exhaust wherein an upstream end of the PF receives exhaust from the engine. A grid of electrically resistive material is applied to an exterior upstream surface of the PF and selectively heats exhaust passing through the grid to initiate combustion of particulates within the PF. A catalyst coating is applied to the PF that increases a temperature of the combustion of the particulates within the PF.

  15. Particulate residue separators for harvesting devices

    DOEpatents

    Hoskinson, Reed L.; Kenney, Kevin L.; Wright, Christopher T.; Hess, John R.

    2010-06-29

    A particulate residue separator and a method for separating a particulate residue stream may include a plenum borne by a harvesting device, and have a first, intake end and a second, exhaust end; first and second particulate residue air streams which are formed by the harvesting device and which travel, at least in part, along the plenum and in a direction of the second, exhaust end; and a baffle assembly which is located in partially occluding relation relative to the plenum, and which substantially separates the first and second particulate residue air streams.

  16. Methods of separating particulate residue streams

    DOEpatents

    Hoskinson, Reed L.; Kenney, Kevin L.; Wright, Christopher T.; Hess, J. Richard

    2011-04-05

    A particulate residue separator and a method for separating a particulate residue stream may include an air plenum borne by a harvesting device, and have a first, intake end and a second, exhaust end; first and second particulate residue air streams that are formed by the harvesting device and that travel, at least in part, along the air plenum and in a direction of the second, exhaust end; and a baffle assembly that is located in partially occluding relation relative to the air plenum and that substantially separates the first and second particulate residue air streams.

  17. Combustor for fine particulate coal

    DOEpatents

    Carlson, Larry W.

    1988-01-01

    A particulate coal combustor with two combustion chambers is provided. The first combustion chamber is toroidal; air and fuel are injected, mixed, circulated and partially combusted. The air to fuel ratio is controlled to avoid production of soot or nitrogen oxides. The mixture is then moved to a second combustion chamber by injection of additional air where combustion is completed and ash removed. Temperature in the second chamber is controlled by cooling and gas mixing. The clean stream of hot gas is then delivered to a prime mover.

  18. Combustor for fine particulate coal

    DOEpatents

    Carlson, L.W.

    1988-01-26

    A particulate coal combustor with two combustion chambers is provided. The first combustion chamber is toroidal; air and fuel are injected, mixed, circulated and partially combusted. The air to fuel ratio is controlled to avoid production of soot or nitrogen oxides. The mixture is then moved to a second combustion chamber by injection of additional air where combustion is completed and ash removed. Temperature in the second chamber is controlled by cooling and gas mixing. The clean stream of hot gas is then delivered to a prime mover. 4 figs.

  19. Combustor for fine particulate coal

    DOEpatents

    Carlson, L.W.

    1988-11-08

    A particulate coal combustor with two combustion chambers is provided. The first combustion chamber is toroidal; air and fuel are injected, mixed, circulated and partially combusted. The air to fuel ratio is controlled to avoid production of soot or nitrogen oxides. The mixture is then moved to a second combustion chamber by injection of additional air where combustion is completed and ash removed. Temperature in the second chamber is controlled by cooling and gas mixing. The clean stream of hot gas is then delivered to a prime mover. 4 figs.

  20. 42 CFR 84.125 - Particulate tests; canisters containing particulate filters; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... filters; minimum requirements. 84.125 Section 84.125 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF... RESPIRATORY PROTECTIVE DEVICES Gas Masks § 84.125 Particulate tests; canisters containing particulate filters; minimum requirements. Gas mask canisters containing filters for protection against particulates...

  1. 42 CFR 84.125 - Particulate tests; canisters containing particulate filters; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... filters; minimum requirements. 84.125 Section 84.125 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF... RESPIRATORY PROTECTIVE DEVICES Gas Masks § 84.125 Particulate tests; canisters containing particulate filters; minimum requirements. Gas mask canisters containing filters for protection against particulates...

  2. 42 CFR 84.125 - Particulate tests; canisters containing particulate filters; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... filters; minimum requirements. 84.125 Section 84.125 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF... RESPIRATORY PROTECTIVE DEVICES Gas Masks § 84.125 Particulate tests; canisters containing particulate filters; minimum requirements. Gas mask canisters containing filters for protection against particulates...

  3. 42 CFR 84.125 - Particulate tests; canisters containing particulate filters; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... filters; minimum requirements. 84.125 Section 84.125 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF... RESPIRATORY PROTECTIVE DEVICES Gas Masks § 84.125 Particulate tests; canisters containing particulate filters; minimum requirements. Gas mask canisters containing filters for protection against particulates...

  4. 42 CFR 84.125 - Particulate tests; canisters containing particulate filters; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... filters; minimum requirements. 84.125 Section 84.125 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF... RESPIRATORY PROTECTIVE DEVICES Gas Masks § 84.125 Particulate tests; canisters containing particulate filters; minimum requirements. Gas mask canisters containing filters for protection against particulates...

  5. Airborne particulate matter in spacecraft

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Acceptability limits and sampling and monitoring strategies for airborne particles in spacecraft were considered. Based on instances of eye and respiratory tract irritation reported by Shuttle flight crews, the following acceptability limits for airborne particles were recommended: for flights of 1 week or less duration (1 mg/cu m for particles less than 10 microns in aerodynamic diameter (AD) plus 1 mg/cu m for particles 10 to 100 microns in AD); and for flights greater than 1 week and up to 6 months in duration (0.2 mg/cu m for particles less than 10 microns in AD plus 0.2 mg/cu m for particles 10 to 100 microns in AD. These numerical limits were recommended to aid in spacecraft atmosphere design which should aim at particulate levels that are a low as reasonably achievable. Sampling of spacecraft atmospheres for particles should include size-fractionated samples of 0 to 10, 10 to 100, and greater than 100 micron particles for mass concentration measurement and elementary chemical analysis by nondestructive analysis techniques. Morphological and chemical analyses of single particles should also be made to aid in identifying airborne particulate sources. Air cleaning systems based on inertial collection principles and fine particle collection devices based on electrostatic precipitation and filtration should be considered for incorporation into spacecraft air circulation systems. It was also recommended that research be carried out in space in the areas of health effects and particle characterization.

  6. Southern Fine Particulate Monitoring Project

    SciTech Connect

    Ashley Williamson

    2003-05-31

    This final project report presents experimental details, results and analysis of continuous onsite ambient fine particulate data at the North Birmingham sampling site during the October, 2001-September, 2002 study period.The host site for these measurement activities is the North Birmingham PM monitoring station by the Jefferson County Health Department in Birmingham, AL.The continuous data include PM{sub 2.5} mass concentrations measured by TEOM, particle sulfate using the R&P 8400S monitor, particle size distributions measured by SMPS and APS monitors, and PM{sub 2.5} light scattering extinction coefficient as measured by nephelometer. During the course of the project, measurement intercomparison data were developed for these instruments and several complementary measurements at the site. The report details the instrument set and operating procedures and describes the resulting data. Report subsections present an overview summary of the data, followed by detailed description of the systematic time behavior of PM{sub 2.5} and other specific particulate size fractions. Specific subsections are included for particle size distribution, light scattering, and particle sulfate data. The final subsection addresses application of the measurements to the practical questions of fine PM generation and transport, source attribution, and PM{sub 2.5} management strategies.

  7. Advanced particulate matter control apparatus and methods

    DOEpatents

    Miller, Stanley J.; Zhuang, Ye; Almlie, Jay C.

    2012-01-10

    Apparatus and methods for collection and removal of particulate matter, including fine particulate matter, from a gas stream, comprising a unique combination of high collection efficiency and ultralow pressure drop across the filter. The apparatus and method utilize simultaneous electrostatic precipitation and membrane filtration of a particular pore size, wherein electrostatic collection and filtration occur on the same surface.

  8. RISK MANAGEMENT FOR INDOOR PARTICULATE MATTER

    EPA Science Inventory

    Because people spend 90% of their time indoors, exposure to particulate matter indoors is a major contributor to the risk associated with particulate matter. The risk due to indoor exposure is probably even higher for susceptible populations such as the elderly, the sick, and t...

  9. Testing Students' Use of the Particulate Theory

    ERIC Educational Resources Information Center

    Williamson, Vickie; Huffman, Jason; Peck, Larry

    2004-01-01

    High School students' understanding about the particulate theory of matter and their use of particulate terminology is investigated. The Physical Changes Concepts Test (PCCT) was administered in two forms, an applied version and a theoretical version, to determine whether students scientifically understood the concepts well enough to apply them to…

  10. Air Quality Criteria for Particulate Matter.

    ERIC Educational Resources Information Center

    National Air Pollution Control Administration (DHEW), Washington, DC.

    To assist states in developing air quality standards, this book offers a review of literature related to atmospheric particulates and the development of criteria for air quality. It not only summarizes the current scientific knowledge of particulate air pollution, but points up the major deficiencies in that knowledge and the need for further…

  11. Advanced Fine Particulate Characterization Methods

    SciTech Connect

    Steven Benson; Lingbu Kong; Alexander Azenkeng; Jason Laumb; Robert Jensen; Edwin Olson; Jill MacKenzie; A.M. Rokanuzzaman

    2007-01-31

    The characterization and control of emissions from combustion sources are of significant importance in improving local and regional air quality. Such emissions include fine particulate matter, organic carbon compounds, and NO{sub x} and SO{sub 2} gases, along with mercury and other toxic metals. This project involved four activities including Further Development of Analytical Techniques for PM{sub 10} and PM{sub 2.5} Characterization and Source Apportionment and Management, Organic Carbonaceous Particulate and Metal Speciation for Source Apportionment Studies, Quantum Modeling, and High-Potassium Carbon Production with Biomass-Coal Blending. The key accomplishments included the development of improved automated methods to characterize the inorganic and organic components particulate matter. The methods involved the use of scanning electron microscopy and x-ray microanalysis for the inorganic fraction and a combination of extractive methods combined with near-edge x-ray absorption fine structure to characterize the organic fraction. These methods have direction application for source apportionment studies of PM because they provide detailed inorganic analysis along with total organic and elemental carbon (OC/EC) quantification. Quantum modeling using density functional theory (DFT) calculations was used to further elucidate a recently developed mechanistic model for mercury speciation in coal combustion systems and interactions on activated carbon. Reaction energies, enthalpies, free energies and binding energies of Hg species to the prototype molecules were derived from the data obtained in these calculations. Bimolecular rate constants for the various elementary steps in the mechanism have been estimated using the hard-sphere collision theory approximation, and the results seem to indicate that extremely fast kinetics could be involved in these surface reactions. Activated carbon was produced from a blend of lignite coal from the Center Mine in North Dakota and

  12. Electrically heated particulate filter propagation support methods and systems

    DOEpatents

    Gonze, Eugene V [Pinckney, MI; Ament, Frank [Troy, MI

    2011-06-07

    A control system that controls regeneration of a particulate filter is provided. The system generally includes a regeneration module that controls current to the particulate filter to initiate combustion of particulate matter in the particulate filter. A propagation module estimates a propagation status of the combustion of the particulate matter based on a combustion temperature. A temperature adjustment module controls the combustion temperature by selectively increasing a temperature of exhaust that passes through the particulate filter.

  13. Radiant zone heated particulate filter

    DOEpatents

    Gonze, Eugene V [Pinckney, MI

    2011-12-27

    A system includes a particulate matter (PM) filter including an upstream end for receiving exhaust gas and a downstream end. A radiant zoned heater includes N zones, where N is an integer greater than one, wherein each of the N zones includes M sub-zones, where M is an integer greater than or equal to one. A control module selectively activates at least a selected one of the N zones to initiate regeneration in downstream portions of the PM filter from the one of the N zones, restricts exhaust gas flow in a portion of the PM filter that corresponds to the selected one of the N zones, and deactivates non-selected ones of the N zones.

  14. Methods for Coating Particulate Material

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

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

  15. Electrically heated particulate filter enhanced ignition strategy

    DOEpatents

    Gonze, Eugene V; Paratore, Jr., Michael J

    2012-10-23

    An exhaust system that processes exhaust generated by an engine is provided. The system generally includes a particulate filter (PF) that filters particulates from the exhaust wherein an upstream end of the PF receives exhaust from the engine. A grid of electrically resistive material is applied to an exterior upstream surface of the PF and selectively heats exhaust passing through the grid to initiate combustion of particulates within the PF. A catalyst coating applied to at least one of the PF and the grid. A control module estimates a temperature of the grid and controls the engine to produce a desired exhaust product to increase the temperature of the grid.

  16. Particulate contamination spectrometer. Volume 1: Technical report

    NASA Technical Reports Server (NTRS)

    Schmitt, R. J.; Boyd, B. A.; Linford, R. M. F.

    1975-01-01

    A laser particulate spectrometer (LPS) system was developed to measure the size and speed distributions of particulate (dusts, aerosols, ice particles, etc.) contaminants. Detection of the particulates was achieved by means of light scattering and extinction effects using a single laser beam to cover a size range of 0.8 to 275 microns diameter and a speed range of 0.2 to 20 meter/second. The LPS system was designed to operate in the high vacuum environment of a space simulation chamber with cold shroud temperatures ranging from 77 to 300 K.

  17. 40 CFR 60.422 - Standards for particulate matter.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standards for particulate matter. 60... Manufacture § 60.422 Standards for particulate matter. On or after the date on which the performance test... sulfate dryer, particulate matter at an emission rate exceeding 0.15 kilogram of particulate per...

  18. 40 CFR 60.422 - Standards for particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards for particulate matter. 60... Manufacture § 60.422 Standards for particulate matter. On or after the date on which the performance test... sulfate dryer, particulate matter at an emission rate exceeding 0.15 kilogram of particulate per...

  19. 40 CFR 60.422 - Standards for particulate matter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standards for particulate matter. 60... Manufacture § 60.422 Standards for particulate matter. On or after the date on which the performance test... sulfate dryer, particulate matter at an emission rate exceeding 0.15 kilogram of particulate per...

  20. PARTICULATE DATA REDUCTION SYSTEM (PADRE) USER GUIDE

    EPA Science Inventory

    The report, a user guide, describes the capabilities and use of the Particulate Data Reduction (PADRE) system, an interactive computer program that facilitates entry, reduction, and analysis of cascade impactor data for particle size distributions. Example sessions are provided t...

  1. OPEN PATH OPTICAL SENSING OF PARTICULATE MATTER

    EPA Science Inventory

    The paper discusses the concepts behind recent developments in optical remote sensing (ORS) and the results from experiments. Airborne fugitive and fine particulate matter (PM) from various sources contribute to exceedances of state and federal PM and visibility standards. Recent...

  2. PARTICULATE SAMPLING SUPPORT: 1977 ANNUAL REPORT

    EPA Science Inventory

    The report describes the activities supporting the particulate sampling efforts of EPA/IERL-RTP during FY 1977. Twenty technical directives were issued in seven categories: cascade impactors (7), cyclones (5), sampling electrostatic precipitators (1), guidelines and manuals (3), ...

  3. PARTICULATE SAMPLING AND SUPPORT: FINAL REPORT

    EPA Science Inventory

    The report summarizes results of research, development, and support tasks performed during the 3-year period. The tasks encompassed many aspects of particulate sampling and measurement in industrial gaseous process and effluent streams. Under this contract, cascade impactors were...

  4. FILTER MEDIA FOR COLLECTING DIESEL PARTICULATE MATTER

    EPA Science Inventory

    Certification of particulate emissions from diesel motor vehicles involves filtration of measured aliquots of the total air diluted exhaust. Seven commercially available filter media were examined for this purpose. The media included a variety of PTFE membrane filters, glass fibe...

  5. GENERATION OF FUMES SIMULATING PARTICULATE AIR POLLUTANTS

    EPA Science Inventory

    The report describes techniques developed for generating large quantities of reproducible, stable, inorganic, fine-particle aerosol fumes. These fumes simulated particulate air pollutants emitted from power generation, basic oxygen furnaces, electric arc furnaces, and zinc smelti...

  6. Atmospheric particulate mercury in Changchun City, China

    NASA Astrophysics Data System (ADS)

    Fang, Fengman; Wang, Qichao; Liu, Ruhai; Ma, Zhuangwei; Hao, Qingju

    From July 1999 to January 2000, the total suspended particulate matter (TSP) in the atmosphere collected by high-volume sampler was used to determine the particulate Hg of four function districts and one contrast district in the City of Changchun,China. The study results indicated that the value of the volume-based concentration and the mass-based concentration of each district during the heating period are higher than those of the nonheating period. The volume-based concentration of the urban districts is higher than that of the contrast district. Atmospheric Hg concentrations varied temporally and spatially. TSP is the critical factor of particulate Hg concentration; precipitation is the main meteorological factor affecting Hg (p) concentration in the atmosphere; coal combustion and wind-blown soil material are the important sources of atmospheric particulate Hg. During heating period, the coal combustion makes a greater contribution to Hg(p) than that of wind-blown soil materials.

  7. Particulate matter, oxidative stress and neurotoxicity.

    EPA Science Inventory

    Particulate matter (PM), a component of air pollution has been epidemiologically associated with sudden deaths, cardiovascular and respiratory illnesses. The effects are more pronounced in patients with pre-existing conditions such as asthma, diabetes or obstructive pulmonary dis...

  8. Differential Spectroscopic Imaging of Particulate Explosives Residue

    SciTech Connect

    Bernacki, Bruce E.; Ho, Nicolas

    2008-04-01

    We present experimental results showing transmission and reflection imaging of approximately 100 microgram quantities of particulate explosives residue using a commercial uncooled microbolometer infrared camera and CO2 laser differential wavelength illumination.

  9. The Particulate Air Pollution Controversy

    PubMed Central

    Phalen, Robert F.

    2004-01-01

    Scientists, regulators, legislators, and segments of industry and the lay public are attempting to understand and respond to epidemiology findings of associations between measures of modern particulate air pollutants (PM) and adverse health outcomes in urban dwellers. The associations have been interpreted to imply that tens of thousands of Americans are killed annually by small daily increments in PM. These epidemiology studies and their interpretations have been challenged, although it is accepted that high concentrations of air pollutants have claimed many lives in the past. Although reproducible and statistically significant, the relative risks associated with modern PM are very small and confounded by many factors. Neither toxicology studies nor human clinical investigations have identified the components and/or characteristics of PM that might be causing the health-effect associations. Currently, a massive worldwide research effort is under way in an attempt to identify whom might be harmed and by what substances and mechanisms. Finding the answers is important, because control measures have the potential not only to be costly but also to limit the availability of goods and services that are important to public health. PMID:19330148

  10. Hypocoordinated solids in particulate media.

    PubMed

    Bertrand, Thibault; Schreck, Carl F; O'Hern, Corey S; Shattuck, Mark D

    2014-06-01

    We propose a "phase diagram" for particulate systems with purely repulsive contact forces, such as granular media and colloids. We characterize two classes of behavior as a function of the input kinetic energy per degree of freedom T_{0} and packing fraction deviation from jamming onset Δϕ=ϕ-ϕ_{J} using simulations of frictionless disks. Isocoordinated solids (ICS) exist above jamming; they possess an average contact number equal to the isostatic value z_{iso}. ICS display "strict" harmonic response, where the density of vibrational modes from the Fourier transform of the velocity autocorrelation function is a set of sharp peaks at eigenfrequencies ω_{k}{d} of the dynamical matrix. In contrast, hypocoordinated solids (HCS) occur above and below jamming and possess fluctuating networks of interparticle contacts but do not undergo cage-breaking particle rearrangements. The density of vibrational frequencies for the HCS is not a collection of sharp peaks at ω_{k}{d}, but it does possess a common form over a range of Δϕ and T_{0}. PMID:25019766

  11. MTCI acoustic agglomeration particulate control

    SciTech Connect

    Chandran, R.R.; Mansour, M.N.; Scaroni, A.W.; Koopmann, G.H.; Loth, J.L.

    1994-10-01

    The overall objective of this project is to demonstrate pulse combination induced acoustic enhancement of coal ash agglomeration and sulfur capture at conditions typical of direct coal-fired turbines and PFBC hot gas cleanup. MTCI has developed an advanced compact pulse combustor island for direct coal-firing in combustion gas turbines. This combustor island comprises a coal-fired pulse combustor, a combined ash agglomeration and sulfur capture chamber (CAASCC), and a hot cyclone. In the MTCI proprietary approach, the pulse combustion-induced high intensity sound waves improve sulfur capture efficiency and ash agglomeration. The resulting agglomerates allow the use of commercial cyclones and achieve very high particulate collection efficiency. In the MTCI proprietary approach, sorbent particles are injected into a gas stream subjected to an intense acoustic field. The acoustic field serves to improve sulfur capture efficiency by enhancing both gas film and intra-particle mass transfer rates. In addition, the sorbent particles act as dynamic filter foci, providing a high density of stagnant agglomerating centers for trapping the finer entrained (in the oscillating flow field) fly ash fractions. A team has been formed with MTCI as the prime contractor and Penn State University and West Virginia University as subcontractors to MTCI. MTCI is focusing on hardware development and system demonstration, PSU is investigating and modeling acoustic agglomeration and sulfur capture, and WVU is studying aerovalve fluid dynamics. Results are presented from all three studies.

  12. Hypocoordinated solids in particulate media

    NASA Astrophysics Data System (ADS)

    Bertrand, Thibault; Schreck, Carl F.; O'Hern, Corey S.; Shattuck, Mark D.

    2014-06-01

    We propose a "phase diagram" for particulate systems with purely repulsive contact forces, such as granular media and colloids. We characterize two classes of behavior as a function of the input kinetic energy per degree of freedom T0 and packing fraction deviation from jamming onset Δϕ =ϕ-ϕJ using simulations of frictionless disks. Isocoordinated solids (ICS) exist above jamming; they possess an average contact number equal to the isostatic value ziso. ICS display "strict" harmonic response, where the density of vibrational modes from the Fourier transform of the velocity autocorrelation function is a set of sharp peaks at eigenfrequencies ωkd of the dynamical matrix. In contrast, hypocoordinated solids (HCS) occur above and below jamming and possess fluctuating networks of interparticle contacts but do not undergo cage-breaking particle rearrangements. The density of vibrational frequencies for the HCS is not a collection of sharp peaks at ωkd, but it does possess a common form over a range of Δϕ and T0.

  13. Particulate contamination in plastic ampoules.

    PubMed

    Oppenheim, R C; Gillies, I R

    1986-05-01

    Plastic ampoules of Water for Injections, JP, and Injection Sodium Chloride, JP, were investigated to determine their particle load. Four batches were studied. The ampoules were twist-opened as they would be in the clinical setting and the total particle load, both inherent and that created in opening, was determined by reading the contents with a HIAC 420 particle counter with a CMB 60 sensor. The total particle content was found to be minimal, easily complying with world L.V.P. standards and the S.V.P. standard of the USP XXI. The number of particles found in these opened plastic ampoules was significantly lower than that found in clinically snap-opened glass ampoules and also slightly lower than that found in laboratory heat-opened glass ampoules. Whilst the plastic ampoule has a restricted application because it is not suitable for all drugs, it is concluded that when they are used as the immediate container for Water for Injections and Injection Sodium Chloride they are highly effective in reducing the particulate contamination generated in opening. PMID:2872309

  14. Flow studies and particulate collection measurements

    SciTech Connect

    Greiner, G.P.; Furlong, D.A.; Bahner, M.A.

    1990-04-01

    This report describes testing of a Reduced Entrainment electrostatic Precipitator (REP) that has a portion of the main precipitator flow drawn through a porous (fabric) collecting surface. Tests investigated effects of flow through the collecting surface (side flow) on precipitator turbulence and particulate removal efficiency. Testing focused on these effects as being significant to the collection of fine (less than 10 microns) particulate. 17 refs., 41 figs., 10 tabs.

  15. Particulate matter in the Venus atmosphere

    NASA Technical Reports Server (NTRS)

    Ragent, B.; Esposito, L. W.; Tomasko, M. G.; Marov, M. IA.; Shari, V. P.

    1985-01-01

    The paper presents a summary of the data currently available (June 1984) describing the planet-enshrouding particulate matter in the Venus atmosphere. A description and discussion of the state of knowledge of the Venus clouds and hazes precedes the tables and plots. The tabular material includes a precis of upper haze and cloud-top properties, parameters for model-size distributions for particles and particulate layers, and columnar masses and mass loadings.

  16. Modeling exposure to particulate matter.

    PubMed

    Moschandreas, Demetrios J; Saksena, Sumeet

    2002-12-01

    Exposure assessment, a component of risk assessment, links sources of pollution with health effects. Exposure models are scientific tools used to gain insights into the processes affecting exposure assessment. The purpose of this paper is to review the process and methodology of estimating inhalation exposure to particulate matter (PM) using various types of models. Three types of models are discussed in the paper. Indirect type of models are physical models that employ inventories of outdoor and indoor sources and their emission rates to identify major sources contributing to exposure to PM, and use fate and transport and indoor air quality models to estimate PM concentrations at receptor sites. PM concentrations and time spent by a subject at each receptor site are input variables to the conventional exposure model that estimates the desired exposure levels. Direct type models use measured exposure or exposure concentrations in conjunction with information obtained from questionnaires to formulate exposure regression models. Stochastic models use exposure measurements, estimates can also be used, to formulate exposure population distributions and investigate associated uncertainty and variability. Since models developed using databases from western countries are not necessarily applicable in developing countries, the difference in requirements among western and developing countries is highlighted in the paper. Employment of exposure modeling methods in developing countries requires development of local information. Such information includes local outdoor and indoor source inventories, local or regional meteorological conditions, adjustment of indoor models to reflect local building construction conditions, and use of questionnaires to obtain local time budget and activity patterns of the subject population. PMID:12492168

  17. Advanced Hybrid Particulate Collector Project Management Plan

    SciTech Connect

    Miller, S.J.

    1995-11-01

    As the consumption of energy increases, its impact on ambient air quality has become a significant concern. Recent studies indicate that fine particles from coal combustion cause health problems as well as atmospheric visibility impairment. These problems are further compounded by the concentration of hazardous trace elements such as mercury, cadmium, selenium, and arsenic in fine particles. Therefore, a current need exists to develop superior, but economical, methods to control emissions of fine particles. Since most of the toxic metals present in coal will be in particulate form, a high level of fine- particle collection appears to be the best method of overall air toxics control. However, over 50% of mercury and a portion of selenium emissions are in vapor form and cannot be collected in particulate control devices. Therefore, this project will focus on developing technology not only to provide ultrahigh collection efficiency of particulate air toxic emissions, but also to capture vapor- phase trace metals such as mercury and selenium. Currently, the primary state-of-the-art technologies for particulate control are fabric filters (baghouses) and electrostatic precipitators (ESPs). However, they both have limitations that prevent them from achieving ultrahigh collection of fine particulate matter and vapor-phase trace metals. The objective of this project is to develop a highly reliable advanced hybrid particulate collector (AHPC) that can provide > 99.99 % particulate collection efficiency for all particle sizes between 0.01 and 50 14m, is applicable for use with all U.S. coals, and is cost-0443competitive with existing technologies. Phase I of the project is organized into three tasks: Task I - Project Management, Reporting, and Subcontract Consulting Task 2 - Modeling, Design, and Construction of 200-acfm AHPC Model Task 3 - Experimental Testing and Subcontract Consulting

  18. Particulate matter pollution in Mexico City

    SciTech Connect

    Vega R, E.; Mora P, V.; Mugica A, V.

    1998-12-31

    The levels of particulate matter are of concern since they may induce severe effects on public health and is the second atmospheric pollution problem in Mexico City. Another noticeable effect in large cities attributable to particulate matter, is the deterioration of visibility. In this paper the analysis of the data of TSP and PM10 during 1988 to 1996 is presented. The seasonal variation of particulate matter, the typical ratios of PM10/TSP and relationships of the two variables were determined. It was found that PM10 concentrations show an important tendency to decrease during this period, due to some control strategies, although this is not the case for TSP. The monthly trend exhibits a clear relationship with the dry (October through April) and wet (May through September) seasons. The particulate matter concentrations are lower during the wet season. The hourly behavior shows that the highest concentrations are correlated with the traffic rush hours. The most TSP polluted area was the northeast, meanwhile the southeast is the most PM10 polluted area. There is a clear evidence of the particulate matter transportation from these areas to other sites of the City.

  19. PRODUCTION OF SHEET FROM PARTICULATE MATERIAL

    DOEpatents

    Blainey, A.

    1959-05-12

    A process is presented for forming coherent sheet material from particulate material such as granular or powdered metal, granular or powdered oxide, slurries, pastes, and plastic mixes which cohere under pressure. The primary object is to avoid the use of expensive and/ or short lived pressing tools, that is, dies and specially profiled rolls, and so to reduce the cost of the product and to prcvide in a simple manner for the making of the product in a variety of shapes or sizes. The sheet material is formed when the particulate material is laterally confined in a boundary material deformable in all lateral directions under axial pressure and then axially compressing the layer of particulate material together with the boundary material.

  20. Polar nephelometer for atmospheric particulate studies.

    PubMed

    Hansen, M Z; Evans, W H

    1980-10-01

    A unique polar nephelometer was designed and constructed for the measurement of atmospheric particulate characteristics. The nephelometer produces visible light from a self-contained laser to irradiate an air sample drawn into the instrument. The light scattered from the particulates and molecules in the sample is detected as a function of scattering angle for each of four different incident light polarizations. These measurements are used to determine the particulate scattering matrix which is a function of the size, shape, and index of refraction of the particles. The region of sensitivity for the measurements corresponds to the size range of particles that strongly affects visible radiative transfer in the atmosphere, which is the primary application for the derived information. PMID:20234624

  1. Particulate control for the year 2000

    SciTech Connect

    Sloat, D.G.; Gaikwad, R.P.

    1997-09-01

    As a response to the Clean Air Act Amendments (CAAAs) of 1990, utilities will be faced with new emission limitations on SO{sub 2} and NO{sub x} that could have a major impact on their current particulate control equipment. Most of the plants affected already have electrostatic precipitators for particulate control. A large number of power plants will be switching to lower sulfur coals as part of the CAAA Title IV Phase 2 SO{sub 2} rules. The lower sulfur coal ash usually does not collect well in a small precipitator so the existing precipitator will need to be upgraded to continue to meet their current emission limitations. Title IV also requires plants to lower NO{sub x} emissions which is often accomplished by modifications to the boiler such as retrofitting low NO{sub x} burners. These boiler modifications can increase the amount of unburned carbon in the ash as well as reduce the size distribution of the fly ash. Both of these changes can negatively impact a precipitator`s performance. Finally, the CAAA Title III identifies 189 pollutants as hazardous air pollutants, also known as air toxics, which have been viewed as a risk to human health. This may result in further tightening of particulate regulations for power plants and place an increased burden on the existing particulate control equipment. This paper evaluates the technologies available to comply with these new and more stringent particulate control requirements. To demonstrate the retrofit alternatives available to meet these new particulate emission requirements, two hypothetical case studies are discussed.

  2. Contribution of organic particulates to respiratory cancer.

    PubMed Central

    Matanoski, G; Fishbein, L; Redmond, C; Rosenkranz, H; Wallace, L

    1986-01-01

    This paper presents some of the issues that remain to be resolved in order to assess the risk of cancer related to exposure to organic particulates. Most reviews of the effects of organic particulates from the outdoor environment on the risk of lung cancer show that this source seems to play a minor role. However, as fuel use and chemical composition of air pollutants change, the contribution of outdoor pollution as a cause of cancer may also change. Indoor air pollution is a more important source of exposure to organic particulates than is outdoor exposure. Although there is clear evidence that in occupational settings organic particulates cause human cancer, there has been almost no study of exposure to these types of particulates within indoor settings. Previous research has focused on cigarette smoke as the major indoor pollutant, but more specific characterization of contaminants in both the workplace and the home is required. The health effects of the higher levels of some of these contaminants in the workplace should be evaluated and the results extrapolated to populations exposed to lower levels in the home. Extensive research is needed to characterize organic particulate mixtures appropriately and test them for carcinogenicity. Studies on the health risks of nitropolynuclear aromatic hydrocarbons and polychlorinated dibenzodioxins and dibenzofurans are reviewed, but their contribution to the overall burden of respiratory cancer in humans cannot be estimated at this time. Characterization of mixtures, assessment of exposures, and linkage of exposures to health effects are the objectives of the recommendations proposed for further research. PMID:3830112

  3. [Suspended particulates and lung health].

    PubMed

    Neuberger, Manfred; Moshammer, Hanns

    2004-01-01

    Based on several severe air pollution episodes, a temporal correlation between high concentrations of particulate matter (PM) and SO2 pollution and acute increases in respiratory and cardiopulmonary mortality had been established in Vienna for the 1970's. After air pollution had decreased in Austria in the 1980's--as documented by data on SO2, and total suspended particles (TSP)--no such associations between day-to-day changes of SO2 and TSP and mortality have been documented any more, however, traffic related pollutants like fine particles and NO2 remained a problem. Therefore, short term effects of PM on lung function, morbidity and mortality were investigated in Vienna, Linz, Graz and a rural control area. Long-term exposure and chronic disease--even more important for public health--were studied in repeated cross-sectional, a mixed longitudinal and a birth cohort study on school children in the city of Linz. Lung function growth was found impaired from long-term exposure to air pollutants and improved in districts where ambient air pollution had decreased. Where only TSP and SO2 had decreased, no continuous improvement of small airway function was found and end-expiratory flow rates stayed impaired where NO2-reduction from technical improvements of cars and industry was counterbalanced by increase of motorized (diesel) traffic. Remaining acute effects of ambient air pollution in 2001 from PM, NO2 and co-pollutants found in a time series study also show that continuing efforts are necessary. Active surface of particles inhaled several hours to days before spirometry was found related to short-term reductions in forced vital capacity-FVC (p<0.01), forced expiratory volume in one second-FEV1 (p<0.01) and maximal expiratory flow rate at 50% of vital capacity-MEF50 (p<0.05). In pupils with asthma or previous airway obstruction 4-week-diaries proved that the following symptoms increased with acute exposure to higher active surface of particles: wheezing (p<0

  4. Measurements of particulate semi-volatile material

    NASA Astrophysics Data System (ADS)

    Pang, Yanbo

    2000-10-01

    A new innovative sampling system, PC-BOSS, was developed by the combination of particle concentrator and BOSS denuder techniques in response to the new EPA PM2.5 standard and to meet top research priorities for particulate matter that were identified by the National Research Council. The PC-BOSS (P_article C_oncentrator- B_righam Young University O_rganic S_ampling S_ystem) can accurately determine not only PM2.5 stable mass and species such as sulfate, but also particulate semi- volatile material. Several field comparison studies of the PC-BOSS with the EPA PM2.5 reference method and state-of-the-art fine particle measurement methods confirm the capability of the PC-BOSS to accurately determine particulate semi-volatile material, especially organic compounds. This is the first routine sampling system for the determination of both particulate semi-volatile inorganic and organic material. Two other denuder system samplers for the determination of PM2.5 total mass including semi-volatile material were also developed for PM2.5 research and exposure monitoring. Results of studies around the United States indicate that the EPA PM2.5 FRM (Federal Reference Method) under- measured PM2.5 mass by 20-30% compared to PC-BOSS results due to the loss of particulate nitrate and semi-volatile organic compounds during sampling. Organic material is mostly responsible for this under- measurement by the FRM. Using our new sampling system in epidemiological and exposure studies will be essential to providing answers to some top research priorities for particulate matter and promote a better PM2.5 standard for the protection of human health because some fractions of particulate semi-volatile organic compounds are toxic and are possibly responsible for health effects associated with exposure to particulate matter. The atmospheric chemistry of organic aerosols in the troposphere and stratosphere is still largely unknown because of the lack of detailed organic aerosol information. The

  5. Particulate matter sensor with a heater

    DOEpatents

    Hall, Matthew

    2011-08-16

    An apparatus to detect particulate matter. The apparatus includes a sensor electrode, a shroud, and a heater. The electrode measures a chemical composition within an exhaust stream. The shroud surrounds at least a portion of the sensor electrode, exclusive of a distal end of the sensor electrode exposed to the exhaust stream. The shroud defines an air gap between the sensor electrode and the shroud and an opening toward the distal end of the sensor electrode. The heater is mounted relative to the sensor electrode. The heater burns off particulate matter in the air gap between the sensor electrode and the shroud.

  6. Method of dispersing particulate aerosol tracer

    DOEpatents

    O'Holleran, Thomas P.

    1988-01-01

    A particulate aerosol tracer which comprises a particulate carrier of sheet silicate composition having a particle size up to one micron, and a cationic dopant chemically absorbed in solid solution in the carrier. The carrier is preferably selected from the group consisting of natural mineral clays such as bentonite, and the dopant is selected from the group consisting of rare earth elements and transition elements. The tracers are dispersed by forming an aqueous salt solution with the dopant present as cations, dispersing the carriers in the solution, and then atomizing the solution under heat sufficient to superheat the solution droplets at a level sufficient to prevent reagglomeration of the carrier particles.

  7. Particulate hot gas stream cleanup technical issues

    SciTech Connect

    Pontius, D.H.; Snyder, T.R.

    1999-09-30

    The analyses of hot gas stream cleanup particulate samples and descriptions of filter performance studied under this contract were designed to address problems with filter operation that have been linked to characteristics of the collected particulate matter. One objective of this work was to generate an interactive, computerized data bank of the key physical and chemical characteristics of ash and char collected from operating advanced particle filters and to relate these characteristics to the operation and performance of these filters. The interactive data bank summarizes analyses of over 160 ash and char samples from fifteen pressurized fluidized-bed combustion and gasification facilities utilizing high-temperature, high pressure barrier filters.

  8. Much ado about dioxides and particulates

    SciTech Connect

    Doane, F.P.

    1980-02-01

    Technical feature: The effect of carbon dioxide on climate is uncertain, and recent high CO2 levels may not persist. Worldwide warming trends since 1840 are outlined. There is no conclusive evidence that increased burning of fossil fuels has had or will have any ill effect on the climate. While there has been a slight increase in the CO2 content of the atmosphere, the oxidation of humus and bogs rather than fossil fuels seems to be the main source of increased atmospheric CO2 and particulates. Increased plant growth and adsorption of CO2 and particulates by the oceans will maintain an even balance in the atmosphere. (17 references, 2 tables)

  9. Pipelining particulate solid material as stable foam slurry

    SciTech Connect

    Fitch, J.L.

    1980-04-29

    A method of transporting particulate solid material through a pipeline in the form of a stable foam slurry is described. A pumpable slurry is formed of the particulate solid material in a stable foam carrier medium and the slurry is flowed through the pipeline to a receiving point. A method of transporting particulate solid materials through a pipeline is described wherein a pumpable slurry is formed of the particulate solid material. The particulate material is present in the stable foam in an amount of at least 20% by volume based on the total volume of the stable foam slurry. The particulate solid material may be coal particles, other forms of particulate carbonaceous material, such as coke, lignite and pitch, ores, and still other particulate material which is insoluble in the stable foam. The foam may be formed from a liquid, usually water, gas, and a foam stabilizing agent, such as a soap or a surfactant. 4 claims.

  10. METALLURGICAL COKE INDUSTRY PARTICULATE EMISSIONS: SOURCE CATEGORY REPORT

    EPA Science Inventory

    The report gives results of a study to develop particulate emission factors based on cutoff size for inhalable particles for the metallurgical coke industry. After a review of available information characterizing particulate emissions from metallurgical coke plants, the data were...

  11. CHARACTERIZATION OF PARTICULATE EMISSIONS FROM NON-FERROUS SMELTERS

    EPA Science Inventory

    Chemical composition and particle size data for particulate emissions for stationary sources are required for environmental health effect assessments, air chemistry studies, and air quality modelling Investigations such as source apportionment. n this study, particulate emissions...

  12. ASPHALTIC CONCRETE INDUSTRY PARTICULATE EMISSIONS: SOURCE CATEGORY REPORT

    EPA Science Inventory

    The report describes the development of particulate emission factors based on cutoff size for inhalable particles for the asphaltic concrete industry. After review of available information characterizing particulate emissions from asphalt concrete plants, the data were summarized...

  13. ALTERNATIVES FOR HIGH-TEMPERATURE/HIGH-PRESSURE PARTICULATE CONTROL

    EPA Science Inventory

    The report gives the status of the most promising high-temperature/high-pressure (HTP) particulate control devices being developed. Data are presented and anticipated performance and development problems are discussed. HTP particulate control offers efficiency and potential econo...

  14. Method and means for diesel exhaust particulate emission control

    SciTech Connect

    Ludecke, O.A.

    1983-04-19

    A method and means for controlling diesel particulate emissions involves providing an exhaust trap filter to collect exhaust particulates at a point near the engine exhaust ports and providing means to periodically vent burning combustion chamber gases to the exhaust filter to initiate combustion and incineration of the collected particulates. Various means for conducting burning mixture to ignite the particulates in the filter are disclosed.

  15. Atmospheric particulate measurements in Norfolk, Virginia

    NASA Technical Reports Server (NTRS)

    Storey, R. W., Jr.; Sentell, R. J.; Woods, D. C.; Smith, J. R.; Harris, F. S., Jr.

    1975-01-01

    Characterization of atmospheric particulates was conducted at a site near the center of Norfolk, Virginia. Air quality was measured in terms of atmospheric mass loading, particle size distribution, and particulate elemental composition for a period of 2 weeks. The objectives of this study were (1) to establish a mean level of air quality and deviations about this mean, (2) to ascertain diurnal changes or special events in air quality, and (3) to evaluate instrumentation and sampling schedules. Simultaneous measurements were made with the following instruments: a quartz crystal microbalance particulate monitor, a light-scattering multirange particle counter, a high-volume air sampler, and polycarbonate membrane filters. To assess the impact of meteorological conditions on air quality variations, continuous data on temperature, relative humidity, wind speed, and wind direction were recorded. Particulate elemental composition was obtained from neutron activation and scanning electron microscopy analyses of polycarbonate membrane filter samples. The measured average mass loading agrees reasonably well with the mass loadings determined by the Virginia State Air Pollution Control Board. There are consistent diurnal increases in atmospheric mass loading in the early morning and a sample time resolution of 1/2 hour seems necessary to detect most of the significant events.

  16. PARTICULATE DATA REDUCTION (PADRE) SYSTEM REFERENCE MANUAL

    EPA Science Inventory

    The report describes how to access and use the Particulate Data Reduction (PADRE) System, an interactive computer program that facilitates entry, reduction, and analysis of cascade impactor data for particle size distributions. It also summarizes its logic and capabilities. The p...

  17. STUDIES OF PARTICULATE REMOVAL FROM DIESEL EXHAUST

    EPA Science Inventory

    The report gives results of a characterization of the collection of particulate emissions from diesel exhaust by several different methods, using 5.7 liter GM diesel engines (as sources) and such controls as fiber and gravel bed filters, trap/cyclones, and ESPs. Overall and fract...

  18. Control Techniques for Particulate Air Pollutants.

    ERIC Educational Resources Information Center

    National Air Pollution Control Administration (DHEW), Washington, DC.

    Included is a comprehensive review of the approaches commonly recommended for controlling the sources of particulate air pollution. Not all possible combinations of control techniques that might bring about more stringent control of each individual source are reviewed. The many agricultural, commercial, domestic, industrial, and municipal…

  19. Particulate control system for biomass firing technologies

    SciTech Connect

    Easom, B.H.; Smolensky, L.A.; Wysk, S.R.

    1996-12-31

    The new particulate control equipment, the so-called Core Separator, overcomes most of the limitations inherent in conventional particulate control systems and can be effectively adapted for biomass applications. The Core Separator is a mechanical collector; however, this technology overcomes the performance limitation inherent in cyclones by performing the tasks of separation and collection in two separate components. The separation process is less affected by secondary flows and is much more efficient than the collection process. Also, the components of the system are arranged in such a way that the separation process determines the system efficiency. As a result, particulate emission rates downstream of this system are one fourth of those from the most efficient cyclones. This technology has been demonstrated through commercial unit installations in the U.S. and abroad. It has been used for industrial separations including coal fly ash, minerals, and chemical recovery applications. It is considered a lower-cost alternative to fabric filters and electrostatic precipitators, albeit one that can meet or exceed regulations for particulate emissions. Development of this technology has been funded by the U.S. Department of Energy, Environmental Protection Agency, and Electric Power Research Institute.

  20. PARTICULATE EMISSION PROFILE OF A COTTON GIN

    Technology Transfer Automated Retrieval System (TEKTRAN)

    PARTICULATE MATTER (PM) IS ONE OF SIX CRITERIA POLLUTANTS REGULATED BY THE ENVIRONMENTAL PROTECTION AGENCY (EPA) WITH NATIONAL AMBIENT AIR QUALITY STANDARDS (NAAQS). IN GENERAL, PM IS THE ONLY AIR POLLUTANT OF CONCERN EMITTED FROM COTTON GINS. THE EPA HAS NAAQS FOR PM10 (PARTICLES WITH AN AERODYNA...

  1. PARTICULATE MATTER RESEARCH Plan (Draft, 2004)

    EPA Science Inventory

    The draft Particulate Matter Research Program Strategy describes the EPA Office of Research and Developments research strategy in the areas of health, exposure, risk assessment, and risk management research. The scope of the strategy corresponds to the dual responsibility of EPA ...

  2. FINE PARTICULATE MATTER EMISSIONS FROM CANDLES

    EPA Science Inventory

    The paper gives reulst of testing five types of candles, purchased from local stores, for fine particulate matter (PM) emissions under close-to-realistic conditions in a research house. The test method allows for determination of both the emission and deposition rates. Most tes...

  3. Miniature Sensors for Airborne Particulate Matter

    EPA Science Inventory

    Our group is working to design a small,lightweight, low-cost real-time particulate matter(PM) sensor to enable better monitoring of PMconcentrations in air, with the goal of informingpolicymakers and regulators to provide betterpublic health. The sensor reads the massconcentratio...

  4. HIGH TEMPERATURE PARTICULATE CONTROL WITH CERAMIC FILTERS

    EPA Science Inventory

    The report gives results of an assessment of using ceramic materials as filters for fine particulate removal at high temperatures. The program was in two phases. Phase I, directed toward the development of a porous alumina membrane filter, had limited success because of the fragi...

  5. REINVENTING PERSONAL EXPOSURE TO PARTICULATE MATTER

    EPA Science Inventory

    Recent epidemiologic studies of modern air pollution show statistically significant relationships between fluctuations of daily non-trauma mortality and fluctuations of daily ambient particulate matter (PM) levels at low concentrations. A review of historic smoke-fog (smog)episo...

  6. SPATIAL PREDICTION OF FINE PARTICULATE MATTER

    EPA Science Inventory

    A new national monitoring network for the measurement of fine particular matter (PM2.5) is currently under development. A primary goal of this network is to collect monitoring data in residential communities for the evaluation of compliance with particulate air quality standards...

  7. Particulate contamination of sterile syringes and needles.

    PubMed

    Taylor, S A

    1982-08-01

    Commercially available sterile needles and syringes have been examined for particulate contamination using the Hiac light blockage technique. The number of particles delivered was small compared with the total number permitted for large volume parenterals. Where syringes are used in particle counting techniques, the contribution of particles should be taken into account. PMID:6126558

  8. PARTICULATE MATTER MULTI-YEAR PLAN

    EPA Science Inventory

    EPA's research on particulate matter (PM) represents the largest portion of the Clean Air research program. In building this program, EPA has been guided by expert advice from the National Research Council of the National Academy of Sciences, and from several other organizations ...

  9. EVALUATIONS OF NOVEL PARTICULATE CONTROL DEVICES

    EPA Science Inventory

    The report gives results of fractional and overall mass efficiency tests of four novel particulate control devices. Three were wet scrubbers: an Aronetics (Chemico) Two-Phase Jet Scrubber, an Entoleter Centrifield Scrubber, and a CEA Variable-Throat Venturi Scrubber. The fourth w...

  10. Source apportionment of particulate matter in Denmark

    NASA Astrophysics Data System (ADS)

    Moenster, J.; Glasius, M.; Nielsen, O. J.; Bilde, M.; Jensen, F. P.

    2005-12-01

    Atmospheric particulate matter (PM) has received considerable attention over the last decade as an important component of air pollution, particularly due to its health effects on the exposed population. Typically the mass of particles with diameters smaller that 10 μm (PM10) has been used in large cohort studies to estimate health effects such as increase in hospitalization rate, asthma attacks and premature deaths. Particles smaller than 2.5 μm (PM2.5) and ultra fine particles have been used in various epidemiological studies and correlations between exposure to fine and ultra fine particles and health effects have been found. Limits of acceptable concentrations of PM10, PM2.5 and some carcinogenic species have been made, and it is important to find the origin of the particulate matter to prevent exceeds of these limits. This can be done by measuring particle mass, organic/inorganic fractions of particles, the chemical components and other relevant factors, and then use receptor modeling for source apportionment of the particulate matter. We have done measurements at street level and urban background in Copenhagen, Denmark, to determine the origin of different sizes of particulate matter and the toxic organic compounds connected to these particles. We also did measurements in a small village with less traffic and more residential wood combustion for a comparison between traffic and wood combustion generated pollution. Our results show a significant amount of particulate matter coming from non local sources and are dominated by long-range transported inorganic salts. The amount of these is highly depended on the wind direction and thus on the origin of the wind plume. The origin of the carcinogenic organic compound benzo(a)pyrene was found to be local combustion sources. To prevent events of high particulate matter concentration in Copenhagen, Denmark, a reduction of emission from the local traffic will only lead to a minor effect, since the majority of the

  11. Development of Particulates and Aerosols Research

    NASA Technical Reports Server (NTRS)

    DeWitt, Kenneth; Rivera, Monica

    2005-01-01

    During the past year several accomplishments were made for both the Particulate Matter Characterization and Measurement System, (PMCMS) and PAGEMS projects. The PAGEMS focus is to measure particulate emissions as a function of combustor parameters such as inlet temperature, inlet pressure and fuel air ratio. These measurements are used to evaluate combustor performance in hopes of correlating particulate emissions with engine conditions. These measurements have taken place at in-house NASA combustor facilities and off-site facilities. Ths work is unique because particulate measurements at high- pressure conditions are not commonly made. Some calibration of the PAGEMS instrumentation was done as well as minor modifications to the PAGEMS plumbing setup. These led to measurement improvements. The instrumentation and measurement process for PAGEMS was assessed and new instruments such as a thermodenuder, thermal mass flow meters and a cyclone separator were purchased to improve the PAGEMS instrumentation and measurement process. A worksheet was created to simulate varying inlet conditions to the DMA. This worksheet allows the user to assess the error in the measurements when certain conditions exist. Two technical papers were written with the PAGEMS team for the EXCAVATE field project. A paper was also reviewed for an in house publication. Also data was processed and analyzed for another field project (PAX) and will be part of a third PAGEMS paper. Accomplishments were also made with the PMCMS project. The calibration of the radial differential mobility analyzer, (RDMA) in the particle sizing system in the PMCMS was completed and provided satisfactory results. The voltages used for the RDMA depending on the particle of interest were corrected. The measurement capability of the PMCMS was increased by replacing the MetOne CPC with a TSI CPC. Lastly, assistance was provided to three college summer students with calibration of their particulate equipment and Monica Rivera

  12. 40 CFR 60.672 - Standard for particulate matter (PM).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standard for particulate matter (PM... Nonmetallic Mineral Processing Plants § 60.672 Standard for particulate matter (PM). (a) Affected facilities... particulate matter to a control device. (b) Affected facilities must meet the fugitive emission limits...

  13. 40 CFR 60.672 - Standard for particulate matter (PM).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for particulate matter (PM... Nonmetallic Mineral Processing Plants § 60.672 Standard for particulate matter (PM). (a) Affected facilities... particulate matter to a control device. (b) Affected facilities must meet the fugitive emission limits...

  14. 40 CFR 60.672 - Standard for particulate matter (PM).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for particulate matter (PM... Nonmetallic Mineral Processing Plants § 60.672 Standard for particulate matter (PM). (a) Affected facilities... particulate matter to a control device. (b) Affected facilities must meet the fugitive emission limits...

  15. 40 CFR 60.672 - Standard for particulate matter (PM).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for particulate matter (PM... Nonmetallic Mineral Processing Plants § 60.672 Standard for particulate matter (PM). (a) Affected facilities... particulate matter to a control device. (b) Affected facilities must meet the fugitive emission limits...

  16. 40 CFR 60.672 - Standard for particulate matter (PM).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for particulate matter (PM... Nonmetallic Mineral Processing Plants § 60.672 Standard for particulate matter (PM). (a) Affected facilities... particulate matter to a control device. (b) Affected facilities must meet the fugitive emission limits...

  17. 40 CFR 60.52 - Standard for particulate matter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for particulate matter. 60.52... § 60.52 Standard for particulate matter. (a) On and after the date on which the initial performance... atmosphere from any affected facility any gases which contain particulate matter in excess of 0.18 g/dscm...

  18. 40 CFR 60.182 - Standard for particulate matter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for particulate matter. 60.182... Smelters § 60.182 Standard for particulate matter. (a) On and after the date on which the performance test... furnace, or sintering machine discharge end any gases which contain particulate matter in excess of 50...

  19. 40 CFR 60.382 - Standard for particulate matter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for particulate matter. 60.382... Processing Plants § 60.382 Standard for particulate matter. (a) On and after the date on which the... stack emissions that: (1) Contain particulate matter in excess of 0.05 grams per dry standard...

  20. 40 CFR 60.142a - Standards for particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards for particulate matter. 60... 20, 1983 § 60.142a Standards for particulate matter. (a) Except as provided under paragraphs (b) and...-blown BOPF and contain particulate matter in excess of 23 mg/dscm (0.010 gr/dscf). (3) Exit from...

  1. 40 CFR 52.1476 - Control strategy: Particulate matter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Control strategy: Particulate matter... strategy: Particulate matter. (a) The requirements of subpart G of this chapter are not met since the plan does not provide for the attainment and maintenance of the national standards for particulate matter...

  2. 40 CFR 60.342 - Standard for particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for particulate matter. 60.342... Manufacturing Plants § 60.342 Standard for particulate matter. (a) On and after the date on which the... gases which: (1) Contain particulate matter in excess of 0.30 kilogram per megagram (0.60 lb/ton)...

  3. 40 CFR 60.52 - Standard for particulate matter.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standard for particulate matter. 60.52... § 60.52 Standard for particulate matter. (a) On and after the date on which the initial performance... atmosphere from any affected facility any gases which contain particulate matter in excess of 0.18 g/dscm...

  4. 40 CFR 60.732 - Standards for particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards for particulate matter. 60... Dryers in Mineral Industries § 60.732 Standards for particulate matter. Each owner or operator of any... particulate matter in excess of 0.092 gram per dry standard cubic meter (g/dscm) for calciners and...

  5. 40 CFR 60.92 - Standard for particulate matter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for particulate matter. 60.92... Facilities § 60.92 Standard for particulate matter. (a) On and after the date on which the performance test... which: (1) Contain particulate matter in excess of 90 mg/dscm (0.04 gr/dscf). (2) Exhibit 20...

  6. 40 CFR 60.132 - Standard for particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for particulate matter. 60.132... and Bronze Production Plants § 60.132 Standard for particulate matter. (a) On and after the date on... reverberatory furnace any gases which: (1) Contain particulate matter in excess of 50 mg/dscm (0.022...

  7. 40 CFR 60.402 - Standard for particulate matter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for particulate matter. 60.402... Plants § 60.402 Standard for particulate matter. (a) On and after the date on which the performance test... which: (i) Contain particulate matter in excess of 0.030 kilogram per megagram of phosphate rock feed...

  8. 40 CFR 60.142a - Standards for particulate matter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standards for particulate matter. 60... 20, 1983 § 60.142a Standards for particulate matter. (a) Except as provided under paragraphs (b) and...-blown BOPF and contain particulate matter in excess of 23 mg/dscm (0.010 gr/dscf). (3) Exit from...

  9. 40 CFR 60.132 - Standard for particulate matter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for particulate matter. 60.132... and Bronze Production Plants § 60.132 Standard for particulate matter. (a) On and after the date on... reverberatory furnace any gases which: (1) Contain particulate matter in excess of 50 mg/dscm (0.022...

  10. 40 CFR 60.262 - Standard for particulate matter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for particulate matter. 60.262... Production Facilities § 60.262 Standard for particulate matter. (a) On and after the date on which the... furnace any gases which: (1) Exit from a control device and contain particulate matter in excess of...

  11. 40 CFR 60.302 - Standard for particulate matter.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for particulate matter. 60.302... § 60.302 Standard for particulate matter. (a) On and after the 60th day of achieving the maximum... a grain dryer any process emission which: (1) Contains particulate matter in excess of 0.023...

  12. 40 CFR 60.302 - Standard for particulate matter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for particulate matter. 60.302... § 60.302 Standard for particulate matter. (a) On and after the 60th day of achieving the maximum... a grain dryer any process emission which: (1) Contains particulate matter in excess of 0.023...

  13. 40 CFR 60.272a - Standard for particulate matter.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standard for particulate matter. 60... Standard for particulate matter. (a) On and after the date of which the performance test required to be... control device and contain particulate matter in excess of 12 mg/dscm (0.0052 gr/dscf); (2) Exit from...

  14. 40 CFR 60.262 - Standard for particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for particulate matter. 60.262... Production Facilities § 60.262 Standard for particulate matter. (a) On and after the date on which the... furnace any gases which: (1) Exit from a control device and contain particulate matter in excess of...

  15. 40 CFR 60.342 - Standard for particulate matter.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for particulate matter. 60.342... Manufacturing Plants § 60.342 Standard for particulate matter. (a) On and after the date on which the... gases which: (1) Contain particulate matter in excess of 0.30 kilogram per megagram (0.60 lb/ton)...

  16. 40 CFR 60.182 - Standard for particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for particulate matter. 60.182... Smelters § 60.182 Standard for particulate matter. (a) On and after the date on which the performance test... furnace, or sintering machine discharge end any gases which contain particulate matter in excess of 50...

  17. 40 CFR 60.732 - Standards for particulate matter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standards for particulate matter. 60... Dryers in Mineral Industries § 60.732 Standards for particulate matter. Each owner or operator of any... particulate matter in excess of 0.092 gram per dry standard cubic meter (g/dscm) for calciners and...

  18. 40 CFR 60.272 - Standard for particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for particulate matter. 60.272... Standard for particulate matter. (a) On and after the date on which the performance test required to be... control device and contain particulate matter in excess of 12 mg/dscm (0.0052 gr/dscf). (2) Exit from...

  19. 40 CFR 60.272 - Standard for particulate matter.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for particulate matter. 60.272... Standard for particulate matter. (a) On and after the date on which the performance test required to be... control device and contain particulate matter in excess of 12 mg/dscm (0.0052 gr/dscf). (2) Exit from...

  20. 40 CFR 60.182 - Standard for particulate matter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for particulate matter. 60.182... Smelters § 60.182 Standard for particulate matter. (a) On and after the date on which the performance test... furnace, or sintering machine discharge end any gases which contain particulate matter in excess of 50...

  1. 40 CFR 60.282 - Standard for particulate matter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for particulate matter. 60.282... § 60.282 Standard for particulate matter. (a) On and after the date on which the performance test...: (i) Contain particulate matter in excess of 0.10 g/dscm (0.044 gr/dscf) corrected to 8 percent...

  2. 40 CFR 60.682 - Standard for particulate matter.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for particulate matter. 60.682... Insulation Manufacturing Plants § 60.682 Standard for particulate matter. On and after the date on which the... gases which contain particulate matter in excess of 5.5 kg/Mg (11.0 1b/ton) of glass pulled....

  3. 40 CFR 60.342 - Standard for particulate matter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for particulate matter. 60.342... Manufacturing Plants § 60.342 Standard for particulate matter. (a) On and after the date on which the... gases which: (1) Contain particulate matter in excess of 0.30 kilogram per megagram (0.60 lb/ton)...

  4. 40 CFR 52.1476 - Control strategy: Particulate matter.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 4 2012-07-01 2012-07-01 false Control strategy: Particulate matter... strategy: Particulate matter. (a) The requirements of subpart G of this chapter are not met since the plan does not provide for the attainment and maintenance of the national standards for particulate matter...

  5. 40 CFR 60.132 - Standard for particulate matter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for particulate matter. 60.132... and Bronze Production Plants § 60.132 Standard for particulate matter. (a) On and after the date on... reverberatory furnace any gases which: (1) Contain particulate matter in excess of 50 mg/dscm (0.022...

  6. 40 CFR 60.402 - Standard for particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for particulate matter. 60.402... Plants § 60.402 Standard for particulate matter. (a) On and after the date on which the performance test... which: (i) Contain particulate matter in excess of 0.030 kilogram per megagram of phosphate rock feed...

  7. 40 CFR 60.272a - Standard for particulate matter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for particulate matter. 60... Standard for particulate matter. (a) On and after the date of which the performance test required to be... control device and contain particulate matter in excess of 12 mg/dscm (0.0052 gr/dscf); (2) Exit from...

  8. 40 CFR 60.302 - Standard for particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for particulate matter. 60.302... § 60.302 Standard for particulate matter. (a) On and after the 60th day of achieving the maximum... a grain dryer any process emission which: (1) Contains particulate matter in excess of 0.023...

  9. 40 CFR 60.262 - Standard for particulate matter.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for particulate matter. 60.262... Production Facilities § 60.262 Standard for particulate matter. (a) On and after the date on which the... furnace any gases which: (1) Exit from a control device and contain particulate matter in excess of...

  10. 40 CFR 52.1476 - Control strategy: Particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy: Particulate matter... strategy: Particulate matter. (a) The requirements of subpart G of this chapter are not met since the plan does not provide for the attainment and maintenance of the national standards for particulate matter...

  11. 40 CFR 60.122 - Standard for particulate matter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for particulate matter. 60.122... Smelters § 60.122 Standard for particulate matter. (a) On and after the date on which the performance test... furnace any gases which: (1) Contain particulate matter in excess of 50 mg/dscm (0.022 gr/dscf)....

  12. 40 CFR 60.182 - Standard for particulate matter.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standard for particulate matter. 60.182... Smelters § 60.182 Standard for particulate matter. (a) On and after the date on which the performance test... furnace, or sintering machine discharge end any gases which contain particulate matter in excess of 50...

  13. 40 CFR 60.142a - Standards for particulate matter.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standards for particulate matter. 60... 20, 1983 § 60.142a Standards for particulate matter. (a) Except as provided under paragraphs (b) and...-blown BOPF and contain particulate matter in excess of 23 mg/dscm (0.010 gr/dscf). (3) Exit from...

  14. 40 CFR 60.92 - Standard for particulate matter.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standard for particulate matter. 60.92... Facilities § 60.92 Standard for particulate matter. (a) On and after the date on which the performance test... which: (1) Contain particulate matter in excess of 90 mg/dscm (0.04 gr/dscf). (2) Exhibit 20...

  15. 40 CFR 60.142 - Standard for particulate matter.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standard for particulate matter. 60.142....142 Standard for particulate matter. (a) Except as provided under paragraph (b) of this section, on... the atmosphere from any affected facility any gases which: (1) Contain particulate matter in excess...

  16. 40 CFR 52.1476 - Control strategy: Particulate matter.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Control strategy: Particulate matter... strategy: Particulate matter. (a) The requirements of subpart G of this chapter are not met since the plan does not provide for the attainment and maintenance of the national standards for particulate matter...

  17. 40 CFR 60.142a - Standards for particulate matter.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standards for particulate matter. 60... 20, 1983 § 60.142a Standards for particulate matter. (a) Except as provided under paragraphs (b) and...-blown BOPF and contain particulate matter in excess of 23 mg/dscm (0.010 gr/dscf). (3) Exit from...

  18. 40 CFR 60.282 - Standard for particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for particulate matter. 60.282... § 60.282 Standard for particulate matter. (a) On and after the date on which the performance test...: (i) Contain particulate matter in excess of 0.10 g/dscm (0.044 gr/dscf) corrected to 8 percent...

  19. 40 CFR 60.272a - Standard for particulate matter.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for particulate matter. 60... Standard for particulate matter. (a) On and after the date of which the performance test required to be... control device and contain particulate matter in excess of 12 mg/dscm (0.0052 gr/dscf); (2) Exit from...

  20. 40 CFR 60.292 - Standards for particulate matter.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standards for particulate matter. 60... Manufacturing Plants § 60.292 Standards for particulate matter. (a) On and after the date on which the..., particulate matter at emission rates exceeding those specified in table CC-1, Column 2 and Column...

  1. 40 CFR 52.2584 - Control strategy; Particulate matter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Control strategy; Particulate matter... Control strategy; Particulate matter. (a) Part D—Disapproval—USEPA disapproves Regulation NR 154.11(7)(b... control strategy to attain and maintain the standards for particulate matter, because it does not...

  2. 40 CFR 60.272 - Standard for particulate matter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for particulate matter. 60.272... Standard for particulate matter. (a) On and after the date on which the performance test required to be... control device and contain particulate matter in excess of 12 mg/dscm (0.0052 gr/dscf). (2) Exit from...

  3. 40 CFR 60.532 - Standards for particulate matter.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standards for particulate matter. 60... Wood Heaters § 60.532 Standards for particulate matter. Unless exempted under § 60.530, each affected... comply with the following particulate matter emission limits as determined by the test methods...

  4. 40 CFR 60.172 - Standard for particulate matter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for particulate matter. 60.172... Smelters § 60.172 Standard for particulate matter. (a) On and after the date on which the performance test... contain particulate matter in excess of 50 mg/dscm (0.022 gr/dscf)....

  5. 40 CFR 60.182 - Standard for particulate matter.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for particulate matter. 60.182... Smelters § 60.182 Standard for particulate matter. (a) On and after the date on which the performance test... furnace, or sintering machine discharge end any gases which contain particulate matter in excess of 50...

  6. 40 CFR 60.272a - Standard for particulate matter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for particulate matter. 60... Standard for particulate matter. (a) On and after the date of which the performance test required to be... control device and contain particulate matter in excess of 12 mg/dscm (0.0052 gr/dscf); (2) Exit from...

  7. 40 CFR 60.52 - Standard for particulate matter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for particulate matter. 60.52... § 60.52 Standard for particulate matter. (a) On and after the date on which the initial performance... atmosphere from any affected facility any gases which contain particulate matter in excess of 0.18 g/dscm...

  8. 40 CFR 52.2584 - Control strategy; Particulate matter.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 5 2012-07-01 2012-07-01 false Control strategy; Particulate matter... Control strategy; Particulate matter. (a) Part D—Disapproval—USEPA disapproves Regulation NR 154.11(7)(b... control strategy to attain and maintain the standards for particulate matter, because it does not...

  9. 40 CFR 60.282 - Standard for particulate matter.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standard for particulate matter. 60.282... § 60.282 Standard for particulate matter. (a) On and after the date on which the performance test...: (i) Contain particulate matter in excess of 0.10 g/dscm (0.044 gr/dscf) corrected to 8 percent...

  10. 40 CFR 60.142a - Standards for particulate matter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standards for particulate matter. 60... 20, 1983 § 60.142a Standards for particulate matter. (a) Except as provided under paragraphs (b) and...-blown BOPF and contain particulate matter in excess of 23 mg/dscm (0.010 gr/dscf). (3) Exit from...

  11. 40 CFR 60.172 - Standard for particulate matter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for particulate matter. 60.172... Smelters § 60.172 Standard for particulate matter. (a) On and after the date on which the performance test... contain particulate matter in excess of 50 mg/dscm (0.022 gr/dscf)....

  12. 40 CFR 52.2584 - Control strategy; Particulate matter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 5 2014-07-01 2014-07-01 false Control strategy; Particulate matter... Control strategy; Particulate matter. (a) Part D—Disapproval—USEPA disapproves Regulation NR 154.11(7)(b... control strategy to attain and maintain the standards for particulate matter, because it does not...

  13. 40 CFR 60.272 - Standard for particulate matter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for particulate matter. 60.272... Standard for particulate matter. (a) On and after the date on which the performance test required to be... control device and contain particulate matter in excess of 12 mg/dscm (0.0052 gr/dscf). (2) Exit from...

  14. 40 CFR 60.92 - Standard for particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for particulate matter. 60.92... Facilities § 60.92 Standard for particulate matter. (a) On and after the date on which the performance test... which: (1) Contain particulate matter in excess of 90 mg/dscm (0.04 gr/dscf). (2) Exhibit 20...

  15. 40 CFR 60.272a - Standard for particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for particulate matter. 60... Standard for particulate matter. (a) On and after the date of which the performance test required to be... control device and contain particulate matter in excess of 12 mg/dscm (0.0052 gr/dscf); (2) Exit from...

  16. 40 CFR 60.122 - Standard for particulate matter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for particulate matter. 60.122... Smelters § 60.122 Standard for particulate matter. (a) On and after the date on which the performance test... furnace any gases which: (1) Contain particulate matter in excess of 50 mg/dscm (0.022 gr/dscf)....

  17. 40 CFR 60.122 - Standard for particulate matter.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standard for particulate matter. 60.122... Smelters § 60.122 Standard for particulate matter. (a) On and after the date on which the performance test... furnace any gases which: (1) Contain particulate matter in excess of 50 mg/dscm (0.022 gr/dscf)....

  18. 40 CFR 60.402 - Standard for particulate matter.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for particulate matter. 60.402... Plants § 60.402 Standard for particulate matter. (a) On and after the date on which the performance test... which: (i) Contain particulate matter in excess of 0.030 kilogram per megagram of phosphate rock feed...

  19. 40 CFR 60.142 - Standard for particulate matter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for particulate matter. 60.142....142 Standard for particulate matter. (a) Except as provided under paragraph (b) of this section, on... the atmosphere from any affected facility any gases which: (1) Contain particulate matter in excess...

  20. 40 CFR 60.472 - Standards for particulate matter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standards for particulate matter. 60... Processing and Asphalt Roofing Manufacture § 60.472 Standards for particulate matter. (a) On and after the...) Particulate matter in excess of: (i) 0.04 kg/Mg (0.08 lb/ton) of asphalt shingle or mineral-surfaced...

  1. 40 CFR 60.162 - Standard for particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for particulate matter. 60.162... Smelters § 60.162 Standard for particulate matter. (a) On and after the date on which the performance test... particulate matter in excess of 50 mg/dscm (0.022 gr/dscf)....

  2. 40 CFR 60.172 - Standard for particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for particulate matter. 60.172... Smelters § 60.172 Standard for particulate matter. (a) On and after the date on which the performance test... contain particulate matter in excess of 50 mg/dscm (0.022 gr/dscf)....

  3. 40 CFR 60.52 - Standard for particulate matter.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for particulate matter. 60.52... § 60.52 Standard for particulate matter. (a) On and after the date on which the initial performance... atmosphere from any affected facility any gases which contain particulate matter in excess of 0.18 g/dscm...

  4. 40 CFR 60.162 - Standard for particulate matter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for particulate matter. 60.162... Smelters § 60.162 Standard for particulate matter. (a) On and after the date on which the performance test... particulate matter in excess of 50 mg/dscm (0.022 gr/dscf)....

  5. 40 CFR 60.682 - Standard for particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for particulate matter. 60.682... Insulation Manufacturing Plants § 60.682 Standard for particulate matter. On and after the date on which the... gases which contain particulate matter in excess of 5.5 kg/Mg (11.0 1b/ton) of glass pulled....

  6. 40 CFR 60.122 - Standard for particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for particulate matter. 60.122... Smelters § 60.122 Standard for particulate matter. (a) On and after the date on which the performance test... furnace any gases which: (1) Contain particulate matter in excess of 50 mg/dscm (0.022 gr/dscf)....

  7. 40 CFR 60.472 - Standards for particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards for particulate matter. 60... Processing and Asphalt Roofing Manufacture § 60.472 Standards for particulate matter. (a) On and after the...) Particulate matter in excess of: (i) 0.04 kg/Mg (0.08 lb/ton) of asphalt shingle or mineral-surfaced...

  8. 40 CFR 60.292 - Standards for particulate matter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standards for particulate matter. 60... Manufacturing Plants § 60.292 Standards for particulate matter. (a) On and after the date on which the..., particulate matter at emission rates exceeding those specified in table CC-1, Column 2 and Column...

  9. 40 CFR 60.92 - Standard for particulate matter.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for particulate matter. 60.92... Facilities § 60.92 Standard for particulate matter. (a) On and after the date on which the performance test... which: (1) Contain particulate matter in excess of 90 mg/dscm (0.04 gr/dscf). (2) Exhibit 20...

  10. 40 CFR 52.2584 - Control strategy; Particulate matter.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 5 2013-07-01 2013-07-01 false Control strategy; Particulate matter... Control strategy; Particulate matter. (a) Part D—Disapproval—USEPA disapproves Regulation NR 154.11(7)(b... control strategy to attain and maintain the standards for particulate matter, because it does not...