Sample records for particulate ecto-nucleotidase cd39

  1. 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

  2. Ecto-nucleotidases Activities in the Contents of Ovarian Endometriomas: Potential Biomarkers of Endometriosis

    PubMed Central

    Texidó, Laura; Romero, Claudia; García-Valero, José; Fernández Montoli, M. Eulalia; Baixeras, Núria; Condom, Enric; Ponce, Jordi; García-Tejedor, Amparo; Martín-Satué, Mireia

    2014-01-01

    Endometriosis, defined as the growth of endometrial tissue outside the uterus, is a common gynecologic condition affecting millions of women worldwide. It is an inflammatory, estrogen-dependent complex disorder, with broad symptomatic variability, pelvic pain, and infertility being the main characteristics. Ovarian endometriomas are frequently developed in women with endometriosis. Late diagnosis is one of the main problems of endometriosis; thus, it is important to identify biomarkers for early diagnosis. The aim of the present work is to evaluate the ecto-nucleotidases activities in the contents of endometriomas. These enzymes, through the regulation of extracellular ATP and adenosine levels, are key enzymes in inflammatory processes, and their expression has been previously characterized in human endometrium. To achieve our objective, the echo-guided aspirated fluids of endometriomas were analyzed by evaluating the ecto-nucleotidases activities and compared with simple cysts. Our results show that enzyme activities are quantifiable in the ovarian cysts aspirates and that endometriomas show significantly higher ecto-nucleotidases activities than simple cysts (5.5-fold increase for ATPase and 20-fold for ADPase), thus being possible candidates for new endometriosis biomarkers. Moreover, we demonstrate the presence of ecto-nucleotidases bearing exosomes in these fluids. These results add up to the knowledge of the physiopathologic mechanisms underlying endometriosis and, open up a promising new field of study. PMID:25276049

  3. CD39 modulates endothelial cell activation and apoptosis.

    PubMed Central

    Goepfert, C.; Imai, M.; Brouard, S.; Csizmadia, E.; Kaczmarek, E.; Robson, S. C.

    2000-01-01

    BACKGROUND: CD39 is the dominant vascular nucleoside triphosphate diphosphohydrolase (NTPDase) that exerts major effects on platelet reactivity by the regulated hydrolysis of extracellular adenine nucleotides. The effects of NTPDases on endothelial cell (EC) activation and apoptosis remain unexplored. MATERIAL AND METHODS: Recombinant replication-deficient adenoviruses were constructed with human CD39 cDNA (rAdCD39) or the bacterial beta-galactosidase (rAdbetagal). RESULTS: Intact human umbilical vein EC cultures infected with rAdCD39 had substantial and stable increases in NTPDase biochemical activity (14.50 +/- 3.50 Pi nmole/well/min), when contrasted with noninfected cells (0.95 +/- 0.002) and rAdbetagal infected cells (1.01 +/- 0.02; p<0.005). Increased NTPDase activity efficiently inhibited immediate type 2Y purinergic receptor (P2Y)-mediated EC activation responses viz. von Willebrand factor secretion in response to extracellular ATP. In addition, CD39 up-regulation blocked ATP-induced translocation of the transcription nuclear factor (NF)-kappaB to the cell nucleus, and abrogated transcription of mRNA encoding E-selectin, and consequent protein synthesis. CD39 also decreased the extent of apoptosis triggered by putative type-2X purinergic (P2X7) receptors in response to high concentrations of extracellular ATP in vitro. CONCLUSION: These properties of CD39 indicate primary vascular protective effects with potential therapeutic applications. PMID:10997340

  4. Phenotypic and functional characteristics of CD4+ CD39+ FOXP3+ and CD4+ CD39+ FOXP3neg T-cell subsets in cancer patients.

    PubMed

    Schuler, Patrick J; Schilling, Bastian; Harasymczuk, Malgorzata; Hoffmann, Thomas K; Johnson, Jonas; Lang, Stephan; Whiteside, Theresa L

    2012-07-01

    Human CD4(+) CD39(+) regulatory T (Treg) cells hydrolyze exogenous adenosine triphosphate (ATP) and participate in immunosuppressive adenosine production. They contain two T-cell subsets whose role in mediating suppression is not understood. Frequencies of both CD4(+) CD39(+) subsets were evaluated in peripheral blood lymphocytes of 57 cancer patients and in tumor infiltrating lymphocytes (TILs) of 6 patients. CD4(+) CD39(+) and CD4(+) CD39(neg) T cells isolated using immunobeads and cell sorting were cultured under various conditions. Their conversion into CD39(+) FOXP3(+) CD25(+) or CD39(+) FOX(neg) CD25(neg) cells was monitored by multiparameter flow cytometry. Hydrolysis of exogenous ATP was measured in luminescence assays. Two CD4(+) CD39(+) cell subsets differing in expression of CD25, FOXP3, CTLA-4, CD121a, PD-1, latency associated peptide (LAP), glycoprotein A repetitions predominant (GARP), and the cytokine profile accumulated with equal frequencies in the blood and tumor tissues of cancer patients. The frequency of both subsets was significantly increased in cancer. CD39 expression levels correlated with the subsets' ability to hydrolyze ATP. Conventional CD4(+) CD39(neg) T cells incubated with IL-2 + TGF-? expanded to generate CD4(+) CD39(+) FOXP3(+) Treg cells, while CD4(+) CD39(+) FOXP3(neg) CD25(neg) subset cells stimulated via the TCR and IL-2 converted to FOXP3(+) CTLA4(+) CD25(+) TGF-?-expressing Treg cells. Among CD4(+) CD39(+) Treg cells, the CD4(+) CD39(+) FOXP3(neg) CD25(neg) subset serves as a reservoir of cells able to convert to Treg cells upon activation by environmental signals. PMID:22585562

  5. Targeting platelet aggregation: CD39 gene transfer augments nucleoside triphosphate diphosphohydrolase activity in injured rabbit arteries

    Microsoft Academic Search

    Sidhu P. Gangadharan; Masato Imai; Kurt K. Rhynhart; Jean Sévigny; Simon C. Robson; Michael S. Conte

    2001-01-01

    Background. CD39, the major endothelial nucleoside triphosphate diphosphohydrolase (NTPDase), plays an important role in local thromboregulation. We hypothesized that balloon injury (BI) leads to an acute reduction in arterial NTPDase activity that could be restored by a targeted gene delivery strategy. Methods. Recombinant adenoviral vectors containing human CD39 (Ad-CD39) or ?-galactosidase (Ad-LacZ) were used. Endothelial (ECs) and smooth muscle cells

  6. CD39 is incorporated into plasma microparticles where it maintains functional properties and impacts endothelial activation

    PubMed Central

    Banz, Yara; Beldi, Guido; Wu, Yan; Atkinson, Ben; Usheva, Anny; Robson, Simon C.

    2010-01-01

    Summary Plasma microparticles (MPs, <1.5 ?m) originate from platelet and cell membrane lipid rafts and possibly regulate inflammatory responses and thrombogenesis. These actions are mediated through their phospholipid-rich surfaces and associated cell-derived surface molecules. The ectonucleotidase CD39/ecto-nucleoside triphosphate diphosphohydrolase1 (E-NTPDase1) modulates purinergic signalling through pericellular ATP and ADP phosphohydrolysis and is localized within lipid rafts in the membranes of endothelial- and immune cells. This study aimed to determine whether CD39 associates with circulating MPs and might further impact phenotype and function. Plasma MPs were found to express CD39 and exhibited classic E-NTPDase ecto-enzymatic activity. Entpd1 (Cd39) deletion in mice produced a pro-inflammatory phenotype associated with quantitative and qualitative differences in the MP populations, as determined by two dimensional-gel electrophoresis, western blot and flow cytometry. Entpd1-null MPs were also more abundant, had significantly higher proportions of platelet- and endothelial-derived elements and decreased levels of interleukin-10, tumour necrosis factor receptor 1 and matrix metalloproteinase 2. Consequently, Cd39-null MP augment endothelial activation, as determined by inflammatory cytokine release and upregulation of adhesion molecules in vitro. In conclusion, CD39 associates with circulating MP and may directly or indirectly confer functional properties. Our data also suggest a modulatory role for CD39 within MP in the exchange of regulatory signals between leucocytes and vascular cells. PMID:18537971

  7. TLR stimulation initiates a CD39-based autoregulatory mechanism that limits macrophage inflammatory responses.

    PubMed

    Cohen, Heather B; Briggs, Katharine T; Marino, John P; Ravid, Katya; Robson, Simon C; Mosser, David M

    2013-09-12

    Sepsis is a highly fatal disease caused by an initial hyperinflammatory response followed by a state of profound immunosuppression. Although it is well appreciated that the initial production of proinflammatory cytokines by macrophages accompanies the onset of sepsis, it remains unclear what causes the transition to an immunosuppressive state. In this study, we reveal that macrophages themselves are key regulators of this transition and that the surface enzyme CD39 plays a critical role in self-limiting the activation process. We demonstrate that Toll-like receptor (TLR)-stimulated macrophages modulate their activation state by increasing the synthesis and secretion of adenosine triphosphate (ATP). This endogenous ATP is paradoxically immunosuppressive due to its rapid catabolism into adenosine by CD39. Macrophages lacking CD39 are unable to transition to a regulatory state and consequently continue to produce inflammatory cytokines. The importance of this transition is demonstrated in a mouse model of sepsis, where small numbers of CD39-deficient macrophages were sufficient to induce lethal endotoxic shock. Thus, these data implicate CD39 as a key "molecular switch" that allows macrophages to self-limit their activation state. We propose that therapeutics targeting the release and hydrolysis of ATP by macrophages may represent new ways to treat inflammatory diseases. PMID:23908469

  8. TLR stimulation initiates a CD39-based autoregulatory mechanism that limits macrophage inflammatory responses

    PubMed Central

    Cohen, Heather B.; Briggs, Katharine T.; Marino, John P.; Ravid, Katya; Robson, Simon C.

    2013-01-01

    Sepsis is a highly fatal disease caused by an initial hyperinflammatory response followed by a state of profound immunosuppression. Although it is well appreciated that the initial production of proinflammatory cytokines by macrophages accompanies the onset of sepsis, it remains unclear what causes the transition to an immunosuppressive state. In this study, we reveal that macrophages themselves are key regulators of this transition and that the surface enzyme CD39 plays a critical role in self-limiting the activation process. We demonstrate that Toll-like receptor (TLR)-stimulated macrophages modulate their activation state by increasing the synthesis and secretion of adenosine triphosphate (ATP). This endogenous ATP is paradoxically immunosuppressive due to its rapid catabolism into adenosine by CD39. Macrophages lacking CD39 are unable to transition to a regulatory state and consequently continue to produce inflammatory cytokines. The importance of this transition is demonstrated in a mouse model of sepsis, where small numbers of CD39-deficient macrophages were sufficient to induce lethal endotoxic shock. Thus, these data implicate CD39 as a key “molecular switch” that allows macrophages to self-limit their activation state. We propose that therapeutics targeting the release and hydrolysis of ATP by macrophages may represent new ways to treat inflammatory diseases. PMID:23908469

  9. CD39, NTPDase 1, is attached to the plasma membrane by two transmembrane domains. Why?

    Microsoft Academic Search

    Alison Grinthal; Guido Guidotti

    2006-01-01

    Since the identification of CD39 and other members of the e-NTPDase (ecto-nucleoside triphosphate diphosphohydrolase) family\\u000a as the primary enzymes responsible for cell surface nucleotide hydrolysis, one of their most intriguing features has been\\u000a their unusual topology. The active site lies in the large extracellular region, but instead of being anchored in the membrane\\u000a by a single transmembrane domain or lipid

  10. Regulatory T Cells Negatively Affect IL-2 Production of Effector T Cells through CD39/Adenosine Pathway in HIV Infection

    PubMed Central

    Jenabian, Mohammad-Ali; Seddiki, Nabila; Yatim, Ahmad; Carriere, Matthieu; Hulin, Anne; Younas, Mehwish; Ghadimi, Elnaz; Kök, Ayrin; Routy, Jean-Pierre; Tremblay, Alain; Sévigny, Jean; Lelievre, Jean-Daniel; Levy, Yves

    2013-01-01

    The mechanisms by which Regulatory T cells suppress IL-2 production of effector CD4+ T cells in pathological conditions are unclear. A subpopulation of human Treg expresses the ectoenzyme CD39, which in association with CD73 converts ATP/ADP/AMP to adenosine. We show here that Treg/CD39+ suppress IL-2 expression of activated CD4+ T-cells more efficiently than Treg/CD39?. This inhibition is due to the demethylation of an essential CpG site of the il-2 gene promoter, which was reversed by an anti-CD39 mAb. By recapitulating the events downstream CD39/adenosine receptor (A2AR) axis, we show that A2AR agonist and soluble cAMP inhibit CpG site demethylation of the il-2 gene promoter. A high frequency of Treg/CD39+ is associated with a low clinical outcome in HIV infection. We show here that CD4+ T-cells from HIV-1 infected individuals express high levels of A2AR and intracellular cAMP. Following in vitro stimulation, these cells exhibit a lower degree of demethylation of il-2 gene promoter associated with a lower expression of IL-2, compared to healthy individuals. These results extend previous data on the role of Treg in HIV infection by filling the gap between expansion of Treg/CD39+ in HIV infection and the suppression of CD4+ T-cell function through inhibition of IL-2 production. PMID:23658513

  11. Distribution of Ecto-nucleotidases In Mouse Sensory Circuits Suggests Roles For NTPDase3 in Nociception and Mechanoreception

    PubMed Central

    Vongtau, Habiba O.; Lavoie, Elise G.; Sévigny, Jean; Molliver, Derek C.

    2011-01-01

    Nucleotide-activated P2X channels and P2Y metabotropic receptors participate in nociceptive signaling. Agonist availability is regulated by nucleoside triphosphate diphosphohydrolase-1 (NTPDase) -1, -2, -3 and -8, a family of enzymes that hydrolyze extracellular ATP to generate adenosine diphosphate (ADP, a P2Y agonist) and monophosphate (AMP). They provide a major source of extracellular AMP, the substrate for adenosine production by ecto-5?-nucleotidase (NT5E), and thereby regulate adenosine (P1) receptor signaling. NTPDases vary in their efficiency of tri- and di-phosphate hydrolysis; therefore which family members are expressed impacts nucleotide availability and half-life. This study employed enzyme activity histochemistry to examine the distribution of ATPase activity and immunohistochemistry for NTPDase1, -2, -3 and -8 in dorsal root ganglion (DRG) and spinal cord. Nucleotidase activity was robust in spinal dorsal horn, confirming that nociceptive pathways are a major site of nucleotide transmission. In DRG, extensive staining revealed ATPase activity in a subset of neurons and in non-neuronal cells. mRNA for NTPDase1-3, but not NTPDase8, was detected in lumbar DRG and spinal cord. Immunoreactivity for NTPDase3 closely matched the distribution of ATPase activity, labeling DRG central projections in the dorsal root and superficial dorsal horn, as well as intrinsic spinal neurons concentrated in lamina II. In DRG, NTPDase3 co-localized with markers of nociceptors and with NT5E. In addition, labeling of a subset of larger-diameter neurons in DRG was consistent with intense staining of Meissner corpuscle afferents in glabrous skin. Merkel cells and terminal Schwann cells of hair follicle afferents were also labeled, but the axons themselves were negative. We propose that NTPDase3 is a key regulator of nociceptive signaling that also makes an unexpected contribution to innocuous tactile sensation. PMID:21807070

  12. Immunohistochemical and functional analysis of ectonucleoside triphosphate diphosphohydrolase 1 (CD39) and ecto-5'-nucleotidase (CD73) in pig aortic valves.

    PubMed

    Kaniewska, Ewa; Sielicka, Alicja; Sarathchandra, Padmini; Pelikant-Ma?ecka, Iwona; Olkowicz, Mariola; S?omi?ska, Ewa M; Chester, Adrian H; Yacoub, Magdi H; Smole?ski, Ryszad T

    2014-01-01

    Extracellular nucleotides control mechanisms such as thrombosis or inflammation that are important in several pathologies, including heart valve disease and calcification. Ectonucleoside triphosphate diphosphohydrolase 1 (eNTPD1, CD39) and ecto-5'-nucleotidase (e5NT, CD73) are ectoenzymes that convert adenosine triphosphate to adenosine diphosphate, adenosine monophosphate and finally to adenosine. Changes in activities of these enzymes influence extracellular nucleotide concentrations and therefore could be involved in valve pathology. This study aimed to analyze type of cells, specific area, level of expression and biochemical function of CD39 and CD73 in pig aortic valves. Samples were collected from aortic valves of domestic pigs. Histological sections were cut from paraffin embedded tissue blocks. Following incubation with primary antibody against CD39 or CD73, washing and secondary goat anti-rabbit secondary antibodies, slides were viewed with NanoZoomer scanner. Substantial expression CD39 and CD73 was observed in two main types of valve cells: endothelial and valve interstitial cells. Subsequently, biochemical function of CD39 and CD73 was evaluated in cells cultured from pig aortic valve. Breakdown of extracellular nucleotides added to cell medium was analyzed with high performance liquid chromatography. In the interstitial cells, the CD73 products formation was much faster than in endothelium, while for the CD39 activity this relation was opposite. Expression and high concentration of CD39 and CD73 products in endothelium are expected, but presence of CD73 in valve interstitial cells is a surprise. We conclude that CD39 and CD73 and their enzymatic activities that convert extracellular nucleotides are highly expressed and could have special function in the valve. PMID:24940684

  13. 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 ?g/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 ?g/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

  14. 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 ?g/ml, and up to 33 % for 15 ?g/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 ?g/ml and 48 ± 6 % for 15 ?g/ml; S1177 phosphorylation increased by 13 ± 3 % for 2.5 ?g/ml and 18 ± 7 % for 15 ?g/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 ?g/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

  15. Interleukin-27 acts on dendritic cells to suppress the T-cell response and autoimmunity by inducing the expression of ENTPD1 (CD39)

    PubMed Central

    Mascanfroni, Ivan D.; Yeste, Ada; Vieira, Silvio M.; Burns, Evan J.; Patel, Bonny; Sloma, Ido; Wu, Yan; Mayo, Lior; Ben-Hamo, Rotem; Efroni, Sol; Kuchroo, Vijay K.; Robson, Simon C.; Quintana, Francisco J.

    2014-01-01

    Dendritic cells (DCs) control the balance between effector and regulatory T cells in vivo. Hence, the study of DCs might identify mechanisms of disease pathogenesis and guide new therapeutic approaches for immune-mediated disorders. We found that IL-27 signaling in murine DCs limits the generation of effector TH1 and TH17 cells and the development of experimental autoimmune encephalomyelitis (EAE). The effects of IL-27 were mediated, at least partially, through the induction of the immunoregulatory molecule ENTPD1 (CD39) in DCs. IL-27-induced ENTPD1 decreased extracellular ATP levels, down-regulating nucleotide-dependent NLRP3 inflammasome activation. Finally, therapeutic vaccination with IL-27-conditioned DCs suppressed established relapsing-remitting EAE. Thus, IL-27 signaling in DCs limits pathogenic T cell responses and the development of autoimmunity. PMID:23995234

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

    PubMed

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

    2015-06-15

    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 ?-subunit of the epithelial sodium channel (ENaC) in medulla, and the major band (85-kDa) of ?-ENaC in TG mice cortex. To evaluate aldosterone-independent differences, in a second experiment, aldosterone was clamped by osmotic minipump at 20 ?g/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 (?-1 subunit), and ?- and ?-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

  17. Xenotransplantation of galactosyl-transferase knockout, CD55, CD59, CD39, and fucosyl-transferase transgenic pig kidneys into baboons.

    PubMed

    Le Bas-Bernardet, S; Tillou, X; Poirier, N; Dilek, N; Chatelais, M; Devallière, J; Charreau, B; Minault, D; Hervouet, J; Renaudin, K; Crossan, C; Scobie, L; Cowan, P J; d'Apice, A J F; Galli, C; Cozzi, E; Soulillou, J P; Vanhove, B; Blancho, G

    2011-11-01

    Galactosyl-transferase knockout (GT-KO) pigs represent the latest major progress to reduce immune reactions in xenotransplantation. However, their organs are still subject to rapid humoral rejection involving complement activation requiring the ongoing development of further genetic modifications in the pig. In a pig-to-baboon renal transplantation setting, we have used donor pigs that are not only GT-KO, but also transgenic for human CD55 (hCD55), hCD59, hCD39, and fucosyl-transferase (hHT). We studied kidney xenograft survival, physiological and immunologic parameters, xenogeneic rejection characteristics, as well as viral transmission aspects among two groups of baboons: control animals (n = 2), versus those (n = 4) treated with a cocktail of cyclophosphamide, tacrolimus, mycophenolate mofetil, steroids, and a recombinant human C1 inhibitor. Whereas control animals showed clear acute humoral rejection at around day 4, the treated animals showed moderately improved graft survival with rejection at around 2 weeks posttransplantation. Biopsies showed signs of acute vascular rejection (interstitial hemorrhage, glomerular thrombi, and acute tubular necrosis) as well as immunoglobulin (Ig)M and complement deposition in the glomerular and peritubular capillaries. The low level of preformed non-Gal-?1.3Gal IgM detected prior to transplantation increased at 6 days posttransplantation, whereas induced IgG appeared after day 6. No porcine endogenous retrovirus (PERV) transmission was detected in any transplanted baboon. Thus, surprisingly, organs from the GT-KO, hCD55, hCD59, hCD39, and hHT transgenic donors did not appear to convey significant protection against baboon anti-pig antibodies and complement activation, which obviously continue to be significant factors under a suboptimal immunosuppression regimen. The association, timing, and doses of immunosuppressive drugs remain critical. They will have to be optimized to achieve longer graft survivals. PMID:22099813

  18. Anti-CD39 and anti-CD73 antibodies A1 and 7G2 improve targeted therapy in ovarian cancer by blocking adenosine-dependent immune evasion

    PubMed Central

    Häusler, Sebastian FM; del Barrio, Itsaso Montalbán; Diessner, Joachim; Stein, Roland G; Strohschein, Jenny; Hönig, Arnd; Dietl, Johannes; Wischhusen, Jörg

    2014-01-01

    The ectonucleotidases CD39 and CD73 degrade ATP to adenosine which inhibits immune responses via the A2A adenosine receptor (ADORA2A) on T and NK cells. The current study investigates the potential therapeutic use of the specific anti CD39- and anti CD73-antibodies A1 (CD39) and 7G2 (CD73) as these two ectonucleotidases are overexpressed in ovarian cancer (OvCA). As expected, NK cell cytotoxicity against the human ovarian cancer cell lines OAW-42 or SK-OV-3 was significantly increased in the presence of A1 or 7G2 antibody. While this might partly be due to antibody-dependent cell-mediated cytotoxicity, a luciferase-dependent assay for quantifying biologically active adenosine further showed that A1 and 7G2 can inhibit CD39 and CD73-dependent adenosine-generation. In turn, the reduction in adenosine levels achieved by addition of A1 and 7G2 to OAW-42 or SK-OV-3 cells was found to de-inhibit the proliferation of CD4+ T cells in coculture with OvCA cells. Likewise, blocking of CD39 and CD73 on OvCA cells via A1 and 7G2 led to an increased cytotoxicity of alloreactive primed T cells. Thus, antibodies like A1 and 7G2 could improve targeted therapy in ovarian cancer not only by specifically labeling overexpressed antigens but also by blocking adenosine-dependent immune evasion in this immunogenic malignancy. PMID:24489992

  19. Milk-Based Nutraceutical for Treating Autoimmune Arthritis via the Stimulation of IL-10- and TGF-?-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-? and IL-10 to potently suppress TNF-? 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

  20. Ecto-Nucleotidases and Nucleoside Transporters Mediate Activation of Adenosine Receptors on Hippocampal Mossy Fibers by P2X7 Receptor Agonist 2'-3'-O-(4-Benzoylbenzoyl)ATP

    Microsoft Academic Search

    Maria Kukley; Pia Stausberg; Giselind Adelmann; Iain P. Chessell; Dirk Dietrich

    2004-01-01

    The ionotropic and cytolytic P2X7 receptor is typically found on immune cells, where it is involved in the release of cytokines. Recently, P2X7 receptors were reported to be localized to presynaptic nerve terminals and to modulate transmitter release. In the present study, we reassessed this unexpected role of P2X7 receptors at hippocampal mossy fiber-CA3 synapses. In agreement with previous findings,

  1. PARTICULATE MATTER RESEARCH 02

    EPA Science Inventory

    2002 PARTICULATE MATTER GPRA Goal 1: Clean Air; Objective 1.1: Ozone, PM, and SO2 NAAQS; Sub-Objective 1.1.5: Particulate Matter Research Description: In July 1997, EPA revised the National Ambient Air Quality Standard (NAAQS) for Particulate Matter (PM), recogniz...

  2. Diesel particulate control

    Microsoft Academic Search

    Bertelsen

    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

  3. Diesel particulate control

    SciTech Connect

    Bertelsen, F.I. (Manufacturers of Emissions Control Association, Washington, DC (US))

    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.

  4. Airborne particulate discriminator

    SciTech Connect

    Creek, Kathryn Louise (San Diego, CA); Castro, Alonso (Santa Fe, NM); Gray, Perry Clayton (Los Alamos, NM)

    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.

  5. RETORT WATER PARTICULATES

    E-print Network

    2011-01-01

    nickel and calcium were removed, presumably as crystals, during the filtration of waters CS~60, -62 and -63.63, -69, and -70) also have elevated percent particulate values for chromium, selenium and nickel

  6. ADVANCED HYBRID PARTICULATE COLLECTOR

    SciTech Connect

    Stanley J. Miller; Grant L. Schelkoph

    1999-04-01

    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 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 transfer of the 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.

  7. ADVANCED HYBRID PARTICULATE COLLECTOR

    SciTech Connect

    Grant L. Schelkoph; Stanley J. Miller

    1999-07-01

    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 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 transfer of the 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.

  8. Microwave regenerated particulate trap

    SciTech Connect

    McDonald, A.C. Jr.; Yonushonis, T.M. [Cummins Engine Co., Inc., Columbus, IN (United States); Haberkamp, W.C.; Mako, F.; Len, L.K,; Silberglitt, R.; Ahmed, I. [FM Technologies, Inc., Fairfax, VA (United States)

    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. PARTICULATE MATTER SUPERSITES PROGRAM

    EPA Science Inventory

    Background: In promulgating the new PM2.5 NAAQS (July 1997), Congress recognized scientific uncertainties associated with fine particulate matter to include composition, source-receptor relationships, and health and exposure effects. As a result, Congress provided EPA with dire...

  10. PARTICULATE MATTER OVERVIEW

    EPA Science Inventory

    In July 1997, the EPA Administrator issued new Particulate Matter (PM) National Ambient Air Quality Standards (NAAQS) that added PM2.5 (PM less than 2.5 micrometers in size). The new standard was developed largely on the basis of epidemiological studies that found relatively con...

  11. 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.

  12. 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.

  13. 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 findings and APICD Gen II subsystems for automated collection, deposition and detection of ambient particulate matter. Key findings from the APTA Program include: Ambient biological PM taxonomy; Demonstration of key subsystems needed for autonomous bioaerosol detection; System design; Efficient electrostatic collection; Automated bioagent recognition; Raman analysis performance validating Td<9 sec; Efficient collection surface regeneration; and Development of a quantitative bioaerosol defection model. The objective of the APTA program was to advance the state of our knowledge of ambient background PM composition. Operation of an automated aerosol detection system was enhanced by a more accurate assessment of background variability, especially for sensitive and specific sensing strategies like Raman detection that are background-limited in performance. Based on this improved knowledge of background, the overall threat detection performance of Raman sensors was improved.

  14. 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.

  15. 7, 1569315721, 2007 Particulate PAH

    E-print Network

    Boyer, Edmond

    ACPD 7, 15693­15721, 2007 Particulate PAH spatial variability and aging in Mexico City D. A #12;ACPD 7, 15693­15721, 2007 Particulate PAH spatial variability and aging in Mexico City D. A in March 2006, we measured particu- late polycyclic aromatic hydrocarbons (PAHs) and other gaseous species

  16. Magnetic characterization of airborne particulates

    NASA Astrophysics Data System (ADS)

    Kim, W.; Doh, S.; Yu, Y.

    2010-12-01

    Burning fossil fuels from vehicles, domestics, industries and power plants in the large urban or industrial areas emit significant quantity of anthropogenic particulates which become a potential threat to human health. Here, we present temporal variability of particulate pollution associated with compositional differences, using magnetic measurements and electron microscopic observations. Six different grain-sizes of airborne particulates have been collected by filtering from 10 precipitation events in Seoul, Korea from February 2009 to June 2009. Magnetic concentration proxies show relatively better (R2 >0.6) and poorer correlations (R2 <0.3) with the masses of samples filtered by >0.45 ?m and <0.45 ?m sizes, respectively, suggesting the usefulness of magnetic characterization for the >0.45 ?m particulates. Temporally, magnetic concentrations are higher in the cold season than the warm season. In particular, a significant increase of magnetic concentration is observed in 3 ?m and 1 ?m filters after the Chinese wind-blown dust events, indicating additional influx of fine-grained anthropogenic particulates into Seoul. Microscopic observations identify that increase of magnetic concentration is highly linked with the frequent occurrence of combustion derived particulates (i.e., carbon and/or sulfur mixed particles) than natural alumino-silicates. Overall, the present study demonstrates that magnetic measurements efficiently reflect the concentration of particulates produced from fossil-fuel combustion among the airborne particles from various sources.

  17. 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.

  18. 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.

  19. 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...

  20. 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...

  1. 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...

  2. 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 ...

  3. Solid particulate aerosol fire suppressants

    Microsoft Academic Search

    Charles J. Kibert; Douglas Dierdorf

    1994-01-01

    A variety of private and public sector programs are developing a new class of fire suppressants, known generically as solid particulate aerosols. These have superior volumetric efficiency, low initial and life-cycle costs, low toxicity, no known global atmospheric environmental impacts (ODP\\/GWP), and the potential for a wide variety of applications. Researchers are developing solid compound formulations that, when pyrotechnically initiated,

  4. Diesel particulate matter emission control

    Microsoft Academic Search

    K. J. Baumgard; W. E. Watts

    1988-01-01

    Diesel particulate matter (DPM) is a normal byproduct of diesel fuel combustion. It is composed mainly of submicrometer, insoluble, carbonaceous soot agglomerates, and adsorbed or condensed soluble organic compounds. DPM is almost entirely respirable in size; therefore, it is regulated under the respirable coal mine dust standard. Tests conducted by the U.S. Bureau of Mines have shown that an engine

  5. Elastodynamic response of particulate composites

    Microsoft Academic Search

    Benjamin Kyle Henderson

    2000-01-01

    The elastodynamic behavior of particulate composites, ranging from one-dimensional chains to a three- dimensional stack of layers of spherical particles, is examined by means of ultrasonic testing. Chains reflect ultrasonic longitudinal waves at frequencies corresponding to the condition that the waves scattered by the spheres interfere constructively. Transmission and reflection spectra for two-dimensional layers of spherical particles in random, square

  6. Monitoring of particulate matter outdoors

    Microsoft Academic Search

    W. E. Wilson; Judith C. Chow; Candis Claiborn; Wei Fusheng; Johann Engelbrecht; John G. Watson

    2002-01-01

    Recent studies of the size and composition of atmospheric particulate matter (PM) have demonstrated the usefulness of separating atmospheric PM into its fine and coarse components. The need to measure the mass and composition of fine and coarse PM separately has been emphasized by research in exposure, epidemiology, and toxicology of atmospheric PM. This paper provides a background on the

  7. Attenuated, flow-induced ATP release contributes to absence of flow-sensitive, purinergic Cai2+ signaling in human ADPKD cyst epithelial cells

    PubMed Central

    Xu, Chang; Shmukler, Boris E.; Nishimura, Katherine; Kaczmarek, Elzbieta; Rossetti, Sandro; Harris, Peter C.; Wandinger-Ness, Angela; Bacallao, Robert L.; Alper, Seth L.

    2009-01-01

    Flow-induced cytosolic Ca2+ Cai2+ signaling in renal tubular epithelial cells is mediated in part through P2 receptor (P2R) activation by locally released ATP. The ability of P2R to regulate salt and water reabsorption has suggested a possible contribution of ATP release and paracrine P2R activation to cystogenesis and/or enlargement in autosomal dominant polycystic kidney disease (ADPKD). We and others have demonstrated in human ADPKD cyst cells the absence of flow-induced Cai2+ signaling exhibited by normal renal epithelial cells. We now extend these findings to primary and telomerase-immortalized normal and ADPKD epithelial cells of different genotype and of both proximal and distal origins. Flow-induced elevation of Cai2+ concentration ([Ca2+]i) was absent from ADPKD cyst cells, but in normal cells was mediated by flow-sensitive ATP release and paracrine P2R activation, modulated by ecto-nucleotidase activity, and abrogated by P2R inhibition or extracellular ATP hydrolysis. In contrast to the elevated ATP release from ADPKD cells in static isotonic conditions or in hypotonic conditions, flow-induced ATP release from cyst cells was lower than from normal cells. Extracellular ATP rapidly reduced thapsigargin-elevated [Ca2+]i in both ADPKD cyst and normal cells, but cyst cells lacked the subsequent, slow, oxidized ATP-sensitive [Ca2+]i recovery present in normal cells. Telomerase-immortalized cyst cells also exhibited altered CD39 and P2X7 mRNA levels. Thus the loss of flow-induced, P2R-mediated Cai2+ signaling in human ADPKD cyst epithelial cells was accompanied by reduced flow-sensitive ATP release, altered purinergic regulation of store-operated Ca2+ entry, and altered expression of gene products controlling extracellular nucleotide signaling. PMID:19244404

  8. 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.

  9. 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.

  10. Particulate emissions from gas turbine engines. Revision

    SciTech Connect

    Not Available

    1992-02-01

    The Aircraft Environmental Support Office is one of four specialty offices within the Naval Environmental Protection Support Service which offers technical support to the naval community. The Aircraft Environmental Support office is primarily responsible for the management and distribution of emissions data for gaseous and particulate air pollutants from aircraft engines. This handbook, Particulate Emissions From Aircraft Engines, is a summary of particulate emissions data collected by the Aircraft Environmental Support Office since 1981. This handbook is intended for environmental personnel at military installations who must provide regulatory agencies with information about particulate matter emitted from their engine test facilities. Most users will find that the sections on visible emissions and particulate emission rates and concentrations contain all the information normally required to make permit applications, emission inventories and related regulatory documents. Also, the section on particle size distributions is appropriate to design applications. Together these sections provide a comprehensive treatment of particulate emissions from aircraft engines.

  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. Zone heated diesel particulate filter electrical connection

    DOEpatents

    Gonze, Eugene V. (Pinckney, MI); Paratore, Jr., Michael J. (Howell, MI)

    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.

  13. Measurement of Particulate Pollutants in the Atmosphere

    NASA Technical Reports Server (NTRS)

    Ckuan, Raymond L.

    1971-01-01

    Representative measurements of the mass concentration of particulate matter in the atmosphere are presented, to demonstrate the application of a new type of instrument evolved from aerospace research to various types of particulate pollution and their dynamics. The instrument employs aerodynamic impaction of particles onto an adhesive-coated piezo-electric crystal whose resonant frequency decreases with mass accretion on its surface, with a resulting particulate mass resolution of 10(exp -11) gram. Applications include air basin with aerial measurement of particulate mass concentration, jet aircraft wake, stationary industrial sources, direct on-line measurement of automobile exhaust, and techniques for source detection.

  14. Methods of separating particulate residue streams

    DOEpatents

    Hoskinson, Reed L. (Rigby, ID); Kenney, Kevin L. (Idaho Falls, ID); Wright, Christopher T. (Idaho Falls, ID); Hess, J. Richard (Idaho Falls, ID)

    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.

  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. Electrically heated particulate filter embedded heater design

    DOEpatents

    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.

  17. Electrically heated particulate filter using catalyst striping

    DOEpatents

    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.

  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. Collective migration Inertial migration Transition to turbulence Particulate flow

    E-print Network

    Collective migration Inertial migration Transition to turbulence Particulate flow ´Elisabeth;Collective migration Inertial migration Transition to turbulence Particulate and granular flows Particulate flow IUSTI - CNRS - Polytech'Marseille #12;Collective migration Inertial migration Transition

  20. 40 CFR 230.21 - Suspended particulates/turbidity.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Suspended particulates/turbidity. 230.21 Section 230.21 Protection of Environment...Aquatic Ecosystem § 230.21 Suspended particulates/turbidity. (a) Suspended particulates in the aquatic...

  1. 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.

  2. Fine particulates-the misunderstood air pollutant

    Microsoft Academic Search

    1974-01-01

    While the data base for quantitative assessment of health and welfare effects is inadequate, sufficient evidence exists to show that fine particulate is a serious air pollution problem. Scrubbers have a unique potential for dealing with the problem; however, conventional scrubbers have limitations for efficient capture of fine particulates. scrubbers designed to make maximal use of filtration or electrostatic mechanisms

  3. Advanced particulate matter control apparatus and methods

    DOEpatents

    Miller, Stanley J. (Grand Forks, ND); Zhuang, Ye (Grand Forks, ND); Almlie, Jay C. (East Grand Forks, MN)

    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.

  4. Particulate Air Pollution In the United States

    Microsoft Academic Search

    A. E. Vandegrift; L. J. Shannon; E. E. Sallee; P. G. Gorman; W. R. Park

    1971-01-01

    A study was conducted to identify, characterize, and quantify the national particulate air pollution problem from stationary sources. Particulate emissions from stationary sources were determined from data on emission factors, grain loadings, and material balances. The principal method used for establishing the tonnage emitted by an industry utilized uncontrolled emission factors. Total tonnage emitted by a given industry was calculated

  5. 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...

  6. PARTICULATE CONTROL HIGHLIGHTS: RECENT DEVELOPMENTS IN JAPAN

    EPA Science Inventory

    The report describes results of visits to Japan to assess research and development of new particulate control technology, and to evaluate the applicability of the Aut-Ainer particulate control device to diesel engines. New technology observed includes hooding systems for coke ove...

  7. Hubble Space Telescope particulate optical test

    NASA Astrophysics Data System (ADS)

    Metheny, Wayne; Pope, Tom; Rosenberg, William; Sharbaugh, Ron

    1987-01-01

    The Particulate Optical Test was designed to record and measure particulate contaminants on the Hubble Space Telescope primary mirror. The objective of the test was to quantify the primary mirror particulate contamination prior to launch. The test consists of taking dark-field photographs of the primary mirror from in front of the telescope's aperture door. These photographs are subsequently digitized and analyzed to produce the areal coverage estimates. The estimated particulate areal obscuration is approximately 1.0 percent of the primary mirror surface in the usable region. This level of contamination is within the budget value of 2.5 percent and indicates that there was little increase in particulate contamination during the HST assembly process or the acoustic test period.

  8. 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 sunflower hulls for the biomass material to be carbonized. The ability to remove mercury from a bituminous coal's derived flue gas was low. Removals of only 15% were attained while injecting 6 lb/Macf of activated carbon upstream of an electrostatic precipitator. Poisoning of sites on the activated carbon by SO{sub 2} and SO{sub 3} contributed to the poor mercury capture performance.

  9. Time Scales in Particulate Systems

    NASA Astrophysics Data System (ADS)

    Zhang, Duan

    2013-06-01

    While there are many interests of studying interactions of individual particles, macroscopic collective behavior of particles are our main interest in many practical applications. In this talk, I will give a brief overview of the multiscale methods connecting the physics at individual particles to macroscopic quantities and averaged equations. The emphasis will be on dense dissipative particulate systems, such as powders. Unlike conservative particle systems, such as molecular systems, in a dissipative particle system the concept of thermodynamic equilibrium is not very useful unless in very special cases, because the only true thermodynamically equilibrium state in these systems is the state in which nothing moves. Other than idealized simple systems, mesoscale structures are common and important in many practical systems, especially in dissipative systems. Spatial correlations of these mesoscale structures, such as force chains in dense granular system, particle clusters and streamers in fluidized beds have received some recent attentions, partly because they can be visualized. This talk will emphasize the effects of time correlations related to the mesoscale structures. To consider time correlations and history information of the system, I will introduce the mathematical foundation of the Liouville equation, its applicability and limitations. I will derive the generalized Liouville equations for particulate systems with and without interstitial fluids, and then use them to study averaged transport equations and related closures. Interactions among the time scale of particle interactions, the time scale of the mesocale structures, and the time scale of the physical problem as represented by strain rate will be discussed. The effect of these interactions on the closure relations will be illustrated. I will also discuss possible numerical methods of solving the averaged equations, and multiscale numerical algorithms bridging the particle level calculations to continuum level calculations. While there are many interests of studying interactions of individual particles, macroscopic collective behavior of particles are our main interest in many practical applications. In this talk, I will give a brief overview of the multiscale methods connecting the physics at individual particles to macroscopic quantities and averaged equations. The emphasis will be on dense dissipative particulate systems, such as powders. Unlike conservative particle systems, such as molecular systems, in a dissipative particle system the concept of thermodynamic equilibrium is not very useful unless in very special cases, because the only true thermodynamically equilibrium state in these systems is the state in which nothing moves. Other than idealized simple systems, mesoscale structures are common and important in many practical systems, especially in dissipative systems. Spatial correlations of these mesoscale structures, such as force chains in dense granular system, particle clusters and streamers in fluidized beds have received some recent attentions, partly because they can be visualized. This talk will emphasize the effects of time correlations related to the mesoscale structures. To consider time correlations and history information of the system, I will introduce the mathematical foundation of the Liouville equation, its applicability and limitations. I will derive the generalized Liouville equations for particulate systems with and without interstitial fluids, and then use them to study averaged transport equations and related closures. Interactions among the time scale of particle interactions, the time scale of the mesocale structures, and the time scale of the physical problem as represented by strain rate will be discussed. The effect of these interactions on the closure relations will be illustrated. I will also discuss possible numerical methods of solving the averaged equations, and multiscale numerical algorithms bridging the particle level calculations to continuum level calculations. This work was sponsored by Stockpile Safety and

  10. 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.

  11. Macrophage-mediated endothelial inflammatory responses to airborne particulates: impact of particulate physicochemical properties.

    PubMed

    Kristovich, Robert; Knight, Deborah A; Long, John F; Williams, Marshall V; Dutta, Prabir K; Waldman, W James

    2004-10-01

    Epidemiological studies have implicated a role for airborne particulates of <2.5 microm diameter in the development/exacerbation of chronic cardiopulmonary disease; however, specific pathogenic mechanisms and the etiological significance of particle physicochemical properties remain unresolved. Using a microporous aluminosilicate zeolite Y as a manifold, we have synthesized 1 microm particulates of pure carbon (C), carbon-iron (C/Fe), and carbon-iron/fluoro-aluminum silicate (C-Fe/F-Al-Si). We have used these particulates, as well as coal fly ash (CFA) and diesel exhaust particulates (DEP), to test the hypotheses that human macrophages treated with particulates elaborate proinflammatory cytokines in quantities sufficient to induce endothelial adhesion molecule expression and that macrophage responses to particulate exposure vary as a function of particulate physicochemical properties. Human monocyte-derived macrophages (Mø) were exposed for 24 h to sublethal concentrations of particulates, at which time phagocytosis was evident from optical microscopy. Human arterial, microvascular, or venous endothelial cells (EC) were treated with clarified supernatants recovered from Mø cultures, stained with fluorescein-conjugated mononclonal antibodies specific for endothelial adhesion molecules intercellular adhesion molecule-1, vascular cell adhesion molecule-1, or E-selectin, and assayed by fluorescence flow cytometry. Data generated by these experiments demonstrate that while supernatants of Mø exposed to CFA and C particulates are relatively ineffective, supernatants from DEP, C/Fe, or C-Fe/F-Al-Si strongly induced adhesion molecule expression on EC, responses which were completely attenuated by antibody with blocking specificity for tumor necrosis factor alpha. Because the only difference between C and C/Fe particulates is the presence of surface iron on C/Fe, these findings suggest particulate-induced oxidative stress as a contributing factor in Mø activation and implicate redox active iron as a major determinant of particulate bioreactivity. PMID:15487890

  12. Characterisation of carbonaceous particulate matter in Edinburgh 

    E-print Network

    Hammonds, Mark David

    2012-06-22

    Airborne particulate matter (PM) has important harmful effects on human health, as well as a number of other important atmospheric effects. Although progress has been made in understanding the sources and effects of PM, ...

  13. 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...

  14. 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.

  15. 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...

  16. 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...

  17. An improved visualization of diesel particulate filter/

    E-print Network

    Boehm, Kevin (Kevin W.)

    2011-01-01

    The prevalence of diesel particulate filters (DPF) is increasing as emissions standards worldwide evolve to match current technologies. Since the first application of DPFs in the 1980's, PM trapping effectiveness has ...

  18. Contribution of organic particulates to respiratory cancer

    SciTech Connect

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

    1986-12-01

    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.

  19. 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

  20. Airborne Particulates over Southern Africa

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This map shows the abundance of airborne particulates, or aerosols, over Southern Africa during the period August 14 - September 29, 2000. Low particle concentrations are shown in shades of blue, and high concentrations in shades of red. The results were generated from MISR imagery acquired over this time period, and processed using MISR's automated software system. The approach for deriving aerosol amount makes use of the variation of scene brightness and contrast as a function of observation angle. Black areas over the land area correspond to places where a result was not obtained, for example, due to the presence of clouds.

    Extensive burning of grass and shrubland for land management and agriculture comprises a principal source of these aerosols. Vegetation availability increases northward, hence the greater abundance of haze and smoke in Angola and southern Zaire. The lower aerosol abundance around Lesotho and southeastern South Africa is consistent with the higher terrain elevations near the Drakensberg Mountains.

    MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

  1. SOUTHERN FINE PARTICULATE MONITORING PROJECT

    SciTech Connect

    Unknown

    2002-04-01

    This quarterly report presents results and analysis of continuous onsite ambient fine particulate data at the North Birmingham sampling site during the January-March, 2002 study period. 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. Some instrumental issues were noted with the upgrade of the APS model 3320 are described in the report, as well as preliminary performance indications for the upgraded instrument. During the quarter preliminary data analysis and modeling studies were conducted to test the potential of the North Birmingham site data for source attribution analyses. Our initial assessment has continued to be optimistic in this regard due to the location of the site relative to several important classes of local and midrange emission sources. We anticipate that these analyses will provide good separations of the effects of major source classes and spatial source clusters, and will provide useful information relevant to PM{sub 2.5} implementation strategies.

  2. New ESP additive controls particulates

    SciTech Connect

    Durham, M.D.; Baldrey, K.E.; Bustard, C.J.; Martin, C.E.; Dharmarajan, N.N.

    1997-06-01

    This article reports that a conditioning agent enhanced precipitator performance after plant switched to low-sulfur coal. Firing low-sulfur coal at a power plant designed for medium- or high-sulfur coal will impact the downstream particulate control device. Since the performance of an electro-static precipitator (ESP) is a strong function of the sulfur content in the coal, switching to a low-sulfur coal will severely impact collection efficiency. Particle resistivity is the dominant parameter affecting the performance of an ESP. When the resistivity is too high, the ESP must be increased in size by a factor of two to three, resulting in proportionally increased capital and operating costs. Fly ash from low-sulfur coal is known to have a typical resistivity one or two orders of magnitude above that for ideal collection efficiency in a well-designed ESP. Therefore, when a utility burning a medium- or high-sulfur coal switches to a low-sulfur coal, the increase in particle resistivity resulting from the reduced SO{sub 3} concentration will lead to severe problems in the ESP. There have been many instances where utilities have switched from a high- to a low-sulfur coal, and the problems caused by the increased resistivity have had such a devastating effect on the performance of the ESP that emissions have increased by a factor of 10.

  3. Evaluation of the NIOSH MWF Total Particulate Matter: Thoracic Particulate Matter Conversion Factor in a Machining Environment

    Microsoft Academic Search

    Beth Donovan Reh; Joshua M. Harney; Robert E. McCleery; Charles A. Mueller

    2005-01-01

    Worker exposures to metalworking fluids were characterized at a plant that produced air compressors. Full-shift, side-by-side air samples (n = 147) were collected and analyzed for total particulate matter, extractable total particulate matter, thoracic particulate matter, and extractable thoracic particulate matter. The thoracic particulate matter geometric mean of 0.32 m\\/mwas below the National Institute for Occupational Safety and Health (NIOSH)

  4. Zevenhoven & Kilpinen PARTICULATES 4.2.2004 5-1 Chapter 5 Particulates

    E-print Network

    Zevenhoven, Ron

    Zevenhoven & Kilpinen PARTICULATES 4.2.2004 5-1 Chapter 5 Particulates 5.1 Introduction Emissions factors contribute to the picture. As the other chapters demonstrate, other pollutants have to be controlled as well and the technologies applied for that do not allow for high loads of fly ash or other

  5. 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

  6. Electrophoretic separation of particulate proteins in seawater

    NASA Astrophysics Data System (ADS)

    Tanoue, Eiichiro

    Proteins are one of the most important organic constituents of all organisms. A major part of particulate organic matter (POM) in seawater is considered to be proteinaceous [Riley, 1970], and a large proportion of the particulate nitrogen (PN) is in the form of proteins or peptides [e.g., Degens, 1970; Packard and Dortch, 1975]. Carbon and nitrogen in amino acids from acid-hydrolyzed proteins account for approximately 30% and 50% or more of the particulate organic carbon (POC) and particulate nitrogen, respectively [Handa, 1970; Siezen and Mague, 1978; Tanoue and Handa, 1979; Tanoue, 1985]. Thus, analysis of amino acids in proteins has been cited in terms of "combined amino acids" or "proteinaceous compounds", and measurements of total amino acid and of the amino acid composition of POM after hydrolysis have received considerable study [e.g., Siezen and Mague, 1978; Lee and Cronin, 1984; Liebezeit and Bölter, 1986; Müller et al., 1986]. However, most proteins in marine organisms, the major source of POM, have similar amino acid compositions [Strickland, 1965; Degens, 1970] even though they differ greatly in biochemical properties. Twenty amino acids make up the basic building blocks of most proteins [Haschemeyer and Haschemeyer, 1973]. Therefore, a comparison of the amino acid composition of samples may not provide much information as to the fate of particulate proteins, i.e., their production, transportation and decomposition, in marine environments.

  7. Method for dispersing catalyst onto particulate material

    DOEpatents

    Utz, Bruce R. (Pittsburgh, PA); Cugini, Anthony V. (Pittsburgh, PA)

    1992-01-01

    A method for dispersing finely divided catalyst precursors onto the surface of coal or other particulate material includes the steps of forming a wet paste mixture of the particulate material and a liquid solution containing a dissolved transition metal salt, for instance a solution of ferric nitrate. The wet paste mixture is in a state of incipient wetness with all of this solution adsorbed onto the surfaces of the particulate material without the presence of free moisture. On adding a precipitating agent such as ammonia, a catalyst precursor such as hydrated iron oxide is deposited on the surfaces of the coal. The catalyst is activated by converting it to the sulfide form for the hydrogenation or direct liquefaction of the coal.

  8. 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

  9. 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)

  10. Modeling of Particulate Behavior in Pinhole Breaches

    SciTech Connect

    Casella, Andrew M.; Loyalka, Sudarshan K.; Hanson, Brady D.

    2014-04-01

    A model is presented for calculating depressurization time for and particulate release from used nuclear fuel dry storage containers that have developed a pinhole breach. Particular attention is given to particulate deposition and transmission within the breach pathway. The model is modular in nature and is developed in a way that allows for more advanced treatments of internal temperature, internal component geometry, or aerosol flow to be readily incorporated. The model can be treated as a basis for addressing concerns associated with monitoring and verification efforts during long-term dry cask storage

  11. Microstructure development in particulate ceramic coatings

    SciTech Connect

    Kim, Y.J.; Wara, N.M.; Francis, L.F. [Univ. of Minnesota, Minneapolis, MN (United States); Velamakanni, B.V. [3M Co., St. Paul, MN (United States)

    1994-12-31

    Microstructure development in particulate coatings is influenced by the particle-particle interactions and additional mechanisms, such as reaction and phase separation, which are driven by compositional changes in a coating during deposition and drying. The effect of agglomeration rate on microstructure uniformity and pore content is demonstrated using coatings produced from aqueous alumina dispersions. The addition of cellulose acetate and acetone to the alumina dispersion leads to phase separation and a coating with large cylindrical pores. The formation of particles by reactions during deposition is also discussed. The pore content of particulate titania coatings prepared in this way can be varied from 30 to 60% by changing the coating conditions.

  12. Particulate matter sensor with a heater

    DOEpatents

    Hall, Matthew (Austin, TX)

    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.

  13. 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.

  14. Size-Dependent Filtration of Non-Loaded Particulate Traps

    E-print Network

    White, Jessica

    2014-12-12

    This work investigates the filtration efficiency of uncoated, commercial Diesel Particulate Filter (DPF) substrates of three porosities (55.8%, 61.1%, 65.0%) for particulate sizes representative of Gasoline Direct Injection (GDI) exhaust, and also...

  15. 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...

  16. Size-Dependent Filtration of Non-Loaded Particulate Traps 

    E-print Network

    White, Jessica

    2014-12-12

    This work investigates the filtration efficiency of uncoated, commercial Diesel Particulate Filter (DPF) substrates of three porosities (55.8%, 61.1%, 65.0%) for particulate sizes representative of Gasoline Direct Injection (GDI) exhaust, and also...

  17. 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...

  18. 40 CFR 52.1131 - Control strategy: Particulate matter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Control strategy: Particulate matter. 52.1131 Section 52.1131 Protection...CONTINUED) Massachusetts § 52.1131 Control strategy: Particulate matter. (a) Revisions to the following...

  19. 40 CFR 52.2429 - Control strategy: Particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Control strategy: Particulate matter. 52.2429 Section 52.2429 Protection...CONTINUED) Virginia § 52.2429 Control strategy: Particulate matter. Determination of Attainment....

  20. 40 CFR 52.1341 - Control strategy: particulate matter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Control strategy: particulate matter. 52.1341 Section 52.1341 Protection...CONTINUED) Missouri § 52.1341 Control strategy: particulate matter. Determination of Attainment....

  1. 40 CFR 52.1131 - Control strategy: Particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Control strategy: Particulate matter. 52.1131 Section 52.1131 Protection...CONTINUED) Massachusetts § 52.1131 Control strategy: Particulate matter. (a) Revisions to the following...

  2. 40 CFR 52.1374 - Control strategy: Particulate matter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Control strategy: Particulate matter. 52.1374 Section 52.1374 Protection...CONTINUED) Montana § 52.1374 Control strategy: Particulate matter. (a) On July 8, 1997, the...

  3. 40 CFR 52.1374 - Control strategy: Particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Control strategy: Particulate matter. 52.1374 Section 52.1374 Protection...CONTINUED) Montana § 52.1374 Control strategy: Particulate matter. (a) On July 8, 1997, the...

  4. 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...

  5. Health Effects of Atmospheric Particulates: A Medical Geology Perspective

    Microsoft Academic Search

    Nurdan S Duzgoren-Aydin

    2008-01-01

    In this review, atmospheric particulates as composite airborne earth materials often containing both natural and anthropogenic components were examined in the context of medical geology. Despite a vast number of both experimental and epidemiological studies confirming the direct and indirect links between atmospheric particulates and human health, the exact nature of mechanisms affecting the particulate-induced pathogenesis largely remains unexplored. Future

  6. Shadow-hiding effect in inhomogeneous layered particulate media

    Microsoft Academic Search

    D. G. Stankevich; Yu. G. Shkuratov; K. Muinonen

    1999-01-01

    Shadow hiding is studied for particulate media consisting of opaque, spherical particles with Lambertian scattering phase functions. The present computer modeling allows geometric optics calculations of the photometric characteristics of layered particulate media with accuracies better than 1%. For statistically homogeneous particulate media, packing density is the single parameter that characterizes the opposition effect due to shadow hiding. The opposition

  7. CHARACTERIZATION OF PARTICULATE EMISSIONS FROM IN-USE DIESEL VEHICLES

    EPA Science Inventory

    Particulate emissions data are presented from a group of 19 in-use diesel automobiles. Five driving cycles and three fuel/lubricating oil combinations have been used to obtain particulate emissions data and also to collect particulate samples for chemical and bioassay characteriz...

  8. Science and technology of catalytic diesel particulate filters

    Microsoft Academic Search

    Barry A. A. L. van Setten; Michiel Makkee; Jacob A. Moulijn

    2001-01-01

    During the last few decades, concerns have grown on the negative effects that diesel particulate matter has on health. Because of this, particulate emissions were subjected to restrictions and various emission-reduction technologies were developed. It is ironic that some of these technologies led to reductions in the legislated total particulate mass while neglecting the number of particles. Focusing on the

  9. MEASURING AND MODELING OF PARTICULATE DISPERSION FROM THE CEMENT PLANTS

    Microsoft Academic Search

    Anchaleeporn W. Lothongkum; Kanyanee Seangkiatiyuth; Vanisa Surapipith

    This work focuses on the dispersion of particulate matters in the atmosphere around key cement plants, situated about 100 km northeast of Bangkok, Thailand. It is aimed at identifying the impact of emission from four cement manufacturers by both measuring and modeling analyses. The daily average concentrations of total suspended particulate matters (TSP) and particulate matters with diameter less than

  10. Microscopy investigations of ash and particulate matter accumulation in diesel particulate filter surface pores

    E-print Network

    Beauboeuf, Daniel P

    2010-01-01

    There has been increased focus on the environmental impact of automobile emissions in recent years. These environmental concerns have resulted in the creation of more stringent particulate matter emissions regulations in ...

  11. Indoor particulate reactive oxygen species concentrations.

    PubMed

    Khurshid, Shahana S; Siegel, Jeffrey A; Kinney, Kerry A

    2014-07-01

    Despite the fact that precursors to reactive oxygen species (ROS) are prevalent indoors, the concentration of ROS inside buildings is unknown. ROS on PM2.5 was measured inside and outside twelve residential buildings and eleven institutional and retail buildings. The mean (± s.d.) concentration of ROS on PM2.5 inside homes (1.37 ± 1.2 nmoles/m(3)) was not significantly different from the outdoor concentration (1.41 ± 1.0 nmoles/m(3)). Similarly, the indoor and outdoor concentrations of ROS on PM2.5 at institutional buildings (1.16 ± 0.38 nmoles/m(3) indoors and 1.68 ± 1.3 nmoles/m(3) outdoors) and retail stores (1.09 ± 0.93 nmoles/m(3) indoors and 1.12 ± 1.1 nmoles/m(3) outdoors) were not significantly different and were comparable to those in residential buildings. The indoor concentration of particulate ROS cannot be predicted based on the measurement of other common indoor pollutants, indicating that it is important to separately assess the concentration of particulate ROS in air quality studies. Daytime indoor occupational and residential exposure to particulate ROS dominates daytime outdoor exposure to particulate ROS. These findings highlight the need for further study of ROS in indoor microenvironments. PMID:24742727

  12. Particulate content of savanna fire emissions

    Microsoft Academic Search

    Hélène Cachier; Catherine Liousse; Patrick Buat-Menard; Annie Gaudichet

    1995-01-01

    As part of the FOS-DECAFE experiment at Lamto (Ivory Coast) in January 1991, various aerosol samples were collected at ground level near prescribed fires or under local background conditions, to characterize the emissions of particulate matter from the burning of savanna vegetation. This paper deals with total aerosol (TPM) and carbon measurements. Detailed trace element and polycyclic hydrocarbon data are

  13. Image analysis of particulate whey protein gels

    Microsoft Academic Search

    Maud Langton; Anne-Marie Hermansson

    1996-01-01

    Two different methods of image analysis have been used to characterize particulate gel networks quantitatively. The methods have been used to analyse the effect of different preparation conditions on the microstructure of whey protein gels. The microstructure has been characterized at different structural levels by light microscopy, transmission electron microscopy and scanning electron microscopy. The structural parameters have been quantified

  14. 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…

  15. ORIGINAL ARTICLE Fine Particulate Matter and Mortality

    E-print Network

    Dominici, Francesca

    ORIGINAL ARTICLE Fine Particulate Matter and Mortality A Comparison of the Six Cities and American.5) on mortality. Using Medicare data, we assessed the association of PM2.5 with mortality for the same locations included in these studies. Methods: We estimated the chronic effects of PM2.5 on mortality for the period

  16. DESIGN OF A LABORATORY FOR PARTICULATE ANALYSIS

    EPA Science Inventory

    The effects on human health resulting from asbestos exposure in various environments are a subject of national concern and debate. In recognition of the need for a 'state-of-the-art' laboratory for particulates analysis, with emphasis on asbestos, the Environmental Protection Age...

  17. Determination of sulfates in diesel particulates

    SciTech Connect

    Schuetzle, D.; Skewes, L.M.; Fisher, G.E.; Levine, S.P.; Gorse, R.A. Jr.

    1981-05-01

    Analytical techniques for the determination of total sulfates in diesel particulates are described utilizing the techniques of total combustion/nondispersive infrared (NDIR) detection and modified extraction/barium perchlorate-thorin titration (BPT). The combustion technique utilizes a commercially available sulfur analyzer (LECO-IR32) that requires less than 15 min for triplicate analysis and has a precision and accuracy of better than +- 5% for filter samples containing from 100 to 10,000 ..mu..g of sulfate. The combustion technique measures soluble and insoluble sulfate such as BaSO/sub 4/ and is not affected by the presence of large quantities of carbon in the particulate sample. The extraction efficiency for sulfates in diesel particulates using standard procedures was found to average 67% for samples containing only trace quantities of anions and 59% for samples containing stoichiometric levels of barium. These procedures have been modified to include ultrasonication with 2-proponal/water in order to overcome the problem of incomplete sulfate extraction. Extracted sulfate samples are then analyzed by using the BPT method. The extraction/BPT method showed an average recovery of 1.02 +- 0.12 (1 sigma) when compared to the combustion technique. ESCA studies showed that the chemical state of the surface sulfur species for the diesel particulates average 93 +- 3% sulfate and 7 +- 3% elemental sulfur.

  18. Reduction of SO2 and Particulate Emissions

    NSDL National Science Digital Library

    1998-01-01

    The Sofia Institute on Local Air Quality is part of the Regional Environmental Center (REC) for Central and Eastern Europe. Its report, Reduction of SO2 and Particulate Emissions, provides both emission data and the legal framework surrounding the reduction of emissions. The report is available either online or as a [.pdf] file.

  19. 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...

  20. Lanthanides as particulate flow markers in ruminants

    E-print Network

    Conner, Michael Cronan

    1977-01-01

    complexes of chromiun! scree adoquatelv in identifying! flow of the liquid phase of digosta. However, since variations i? particulate flow are pr i!marila?responsible for vai iacions in feed intake, markers which ren!ai!! associated with varicus pa...

  1. 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...

  2. FERROALLOY INDUSTRY PARTICULATE EMISSIONS: SOURCE CATEGORY REPORT

    EPA Science Inventory

    The report gives results of a review of all available data characterizing particulate emissions from ferroalloy-producing electric arc furnaces. The data were summarized and rated in terms of reliability. Total and size specific emission factors were developed for the ferroalloy ...

  3. Secondary Particulate Matter from Meteor Vapors

    Microsoft Academic Search

    J. Rosinski; R. H. Snow

    1961-01-01

    The size distribution of secondary particulate matter, formed from condensing vapors in meteoric trains in the meteoric evaporating zone, was calculated. The diameters of the particles were found to be approximately proportional to the size of the meteor. The particles were calculated to be below 100 A in diameter, and the median volume diameters ranged from 4.5 to 80 A

  4. Inverse problem modeling of particulate systems

    Microsoft Academic Search

    Alan Waite Mahoney

    2001-01-01

    Particulate systems are widely used in the chemical industry both for final product properties and for convenience of processing. For these purposes, the particle size distribution affects the product value or processing cost, and therefore is an important factor in design and control. These goals are complicated by the nonlinear, distributed nature of the system and the poor availability of

  5. 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 ...

  6. 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 ?m (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 ?m (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 particulate matter is from long-range transport. A reduction in combustion generated particles would lead to a significant decrease in the smallest particle sizes and in the concentration of traffic generated toxics like benzo(a)pyrene.

  7. Particulate Concentration Levels in Chinatown, Oakland, California

    NASA Astrophysics Data System (ADS)

    Chen, B.; Yeung, A.; Yu, J. F.

    2007-12-01

    Chinatown is located near the center of the busy business district of downtown Oakland, California. It is one of the most inhabited and congested areas in the City of Oakland, averaging 4,000 vehicles and 3,000 pedestrians per hour at a key intersection in the center of the neighborhood. Particles produced by automobiles and construction can settle into the bronchi of lungs and induce asthma attacks, irritate cardiovascular tissue, and possibly lead to lung cancer and death. Particulate pollution is a serious problem that is estimated to cause between 20,000 and 50,000 deaths per year in the US alone. Hence, evaluation of the air quality of the Chinatown neighborhood is important, because it helps to address issues that are of great concern to residents of the area. The primary goal of our project was to measure particulate concentration levels at various intersections in Oakland's Chinatown to determine if the air quality met U.S. EPA standards, and to take note of any trends that may occur over a period of months. We were primarily concerned with particles that are 2.5 micrometers diameter and smaller, as smaller particles are easily inhaled and directly affect the respiratory system. We were interested in identifying any intersections that may have had significantly higher levels than other intersections. Using a map of Chinatown, we chose 12 intersections and made measurements at these points over the course of six months, beginning in February and ending in July of 2007. Particulate matter measurements were made using a FLUKE 893 Particle Counter. Measurements recorded on the first day of our study, February 4, 2007, which was the day of an annual street festival, yielded the highest values for particulate matter concentration in our dataset. This was followed by a significant drop in concentration the following week, and then a gradual increase of concentration as the months progressed. No one location yielded values significantly higher than any other, and, except for the first and last day (where there was experimental error), recorded values seem to meet EPA standards. We conclude that the high particulate matter levels we observed were due to heavy crowding and traffic jams near street corners during the time of the festival. We also conclude that particulate pollution levels in the Chinatown neighborhood are generally acceptable, except during festivities that generate heavy congestion. We intend conduct further investigations, particularly at next year's street festival, to confirm observations made thus far.

  8. Atmospheric particulate analysis using angular light scattering

    NASA Technical Reports Server (NTRS)

    Hansen, M. Z.

    1980-01-01

    Using the light scattering matrix elements measured by a polar nephelometer, a procedure for estimating the characteristics of atmospheric particulates was developed. A theoretical library data set of scattering matrices derived from Mie theory was tabulated for a range of values of the size parameter and refractive index typical of atmospheric particles. Integration over the size parameter yielded the scattering matrix elements for a variety of hypothesized particulate size distributions. A least squares curve fitting technique was used to find a best fit from the library data for the experimental measurements. This was used as a first guess for a nonlinear iterative inversion of the size distributions. A real index of 1.50 and an imaginary index of -0.005 are representative of the smoothed inversion results for the near ground level atmospheric aerosol in Tucson.

  9. Toxicity of inhaled traffic related particulate matter

    NASA Astrophysics Data System (ADS)

    Gerlofs-Nijland, Miriam E.; Campbell, Arezoo; Miller, Mark R.; Newby, David E.; Cassee, Flemming R.

    2009-02-01

    Traffic generated ultrafine particulates may play a major role in the development of adverse health effects. However, little is known about harmful effects caused by recurring exposure. We hypothesized that repeated exposure to particulate matter results in adverse pulmonary and systemic toxic effects. Exposure to diesel engine exhaust resulted in signs of oxidative stress in the lung, impaired coagulation, and changes in the immune system. Pro-inflammatory cytokine levels were decreased in some regions of the brain but increased in the striatum implying that exposure to diesel engine exhaust may selectively aggravate neurological impairment. Data from these three studies suggest that exposure to traffic related PM can mediate changes in the vasculature and brain of healthy rats. To what extent these changes may contribute to chronic neurodegenerative or vascular diseases is at present unclear.

  10. Apparatus for measuring surface particulate contamination

    DOEpatents

    Woodmansee, Donald E. (Simpsonville, SC)

    2002-01-01

    An apparatus for measuring surface particulate contamination includes a tool for collecting a contamination sample from a target surface, a mask having an opening of known area formed therein for defining the target surface, and a flexible connector connecting the tool to the mask. The tool includes a body portion having a large diameter section defining a surface and a small diameter section extending from the large diameter section. A particulate collector is removably mounted on the surface of the large diameter section for collecting the contaminants. The tool further includes a spindle extending from the small diameter section and a spool slidingly mounted on the spindle. A spring is disposed between the small diameter section and the spool for biasing the spool away from the small diameter section. An indicator is provided on the spindle so as to be revealed when the spool is pressed downward to compress the spring.

  11. Face crack reduction strategy for particulate filters

    DOEpatents

    Gonze, Eugene V [Pinckney, MI

    2012-01-31

    A system comprises a particulate matter (PM) filter that comprises an upstream end for receiving exhaust gas, a downstream end and at least one portion. A control module initiates combustion of PM in the PM filter using a heater and selectively adjusts oxygen levels of the exhaust gas to adjust a temperature of combustion adjacent to the at least one portion of the PM filter. A method comprises providing a particulate matter (PM) filter that comprises an upstream end for receiving exhaust gas, a downstream end and at least one portion; initiating combustion of PM in the PM filter using a heater; selectively adjusting oxygen levels of the exhaust gas to adjust a temperature of combustion adjacent to the at least one portion of the PM filter.

  12. Sensor Technologies for Particulate Detection and Characterization

    NASA Technical Reports Server (NTRS)

    Greenberg, Paul S.

    2008-01-01

    Planned Lunar missions have resulted in renewed attention to problems attributable to fine particulates. While the difficulties experienced during the sequence of Apollo missions did not prove critical in all cases, the comparatively long duration of impending missions may present a different situation. This situation creates the need for a spectrum of particulate sensing technologies. From a fundamental perspective, an improved understanding of the properties of the dust fraction is required. Described here is laboratory-based reference instrumentation for the measurement of fundamental particle size distribution (PSD) functions from 2.5 nanometers to 20 micrometers. Concomitant efforts for separating samples into fractional size bins are also presented. A requirement also exists for developing mission compatible sensors. Examples include provisions for air quality monitoring in spacecraft and remote habitation modules. Required sensor attributes such as low mass, volume, and power consumption, autonomy of operation, and extended reliability cannot be accommodated by existing technologies.

  13. Wastewater treatment with particulate biofilm reactors

    Microsoft Academic Search

    C. Nicolella; M. C. M. van Loosdrecht; J. J. Heijnen

    2000-01-01

    The review presented in this paper focuses on applications of particulate biofilm reactors (e.g. Upflow Sludge Blanket, Biofilm Fluidized Bed, Expanded Granular Sludge Blanket, Biofilm Airlift Suspension, Internal Circulation reactors). Several full-scale applications for municipal and industrial wastewater treatment are presented and illustrated, and their most important design and operation aspects (e.g. biofilm formation, hydrodynamics, mass transfer, mixing) are analysed

  14. Generator powered electrically heated diesel particulate filter

    DOEpatents

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

    2014-03-18

    A control circuit for a vehicle powertrain includes a switch that selectivity interrupts current flow between a first terminal and a second terminal. A first power source provides power to the first terminal and a second power source provides power to the second terminal and to a heater of a heated diesel particulate filter (DPF). The switch is opened during a DPF regeneration cycle to prevent the first power source from being loaded by the heater while the heater is energized.

  15. Self-Cleaning Particulate Prefilter Media

    NASA Technical Reports Server (NTRS)

    Weber, Olivia; Lalwani, San-jiv; Sharma, Anjal

    2012-01-01

    A long-term space mission requires efficient air revitalization performance to sustain the crew. Prefilter and particulate air filter media are susceptible to rapid fouling that adversely affects their performance and can lead to catastrophic failure of the air revitalization system, which may result in mission failure. For a long-term voyage, it is impractical to carry replacement particulate prefilter and filter modules due to the usual limitations in size, volume, and weight. The only solution to this problem is to reagentlessly regenerate prefilter and filter media in place. A method was developed to modify the particulate prefilter media to allow them to regenerate reagentlessly, and in place, by the application of modest thermocycled transverse or reversed airflows. The innovation may allow NASA to close the breathing air loop more efficiently, thereby sustaining the vision for manned space exploration missions of the future. A novel, self-cleaning coatings technology was developed for air filter media surfaces that allows reagentless in-place regeneration of the surface. The technology grafts thermoresponsive and nonspecific adhesion minimizing polymer nanolayer brush coatings from the prefilter media. These polymer nanolayer brush architectures can be triggered to contract and expand to generate a "pushing-off" force by the simple application of modestly thermocycled (i.e. cycling from ambient cabin temperature to 40 C) air streams. The nonspecific adhesion-minimizing properties of the coatings do not allow the particulate foulants to adhere strongly to the filter media, and thermocycled air streams applied to the media allow easy detachment and in-place regeneration of the media with minimal impact in system downtime or astronaut involvement in overseeing the process.

  16. Prediction of particulate contamination on aperture window

    NASA Technical Reports Server (NTRS)

    Lee, Aleck L.; Fong, Michael C.

    1994-01-01

    This paper presents an analysis to predict the effects of light scattering by surface particles on the sensor window of a missile during ascent flight. The particulate contaminant distribution on the window is calculated by tallying the number of particles in a set of size ranges. The particulate contamination at the end of the mission is predicted by adding the contributions from the events of ground and flight operations. The surface particle redistributions caused by vibroacoustically induced surface acceleration was found to contribute the most of the particulate surface contamination. The analytical surface obscuration calculation with a set of particle counts was compared to the results of image analyzer measurement. The analytical results, which were calculated with a given function of particle shape depending on the size, were more conservative than the measurement. A scattering calculation using a verified BSDF model showed that the scattering was less than 0.001 at 20 off the direction of the incident light in the mid IR wavelength when the surfaces were at Level 300 initially.

  17. Cometary particulate analyzer design definition study

    NASA Technical Reports Server (NTRS)

    Utterback, N. G.

    1981-01-01

    A concept for remotely determining the relative abundance of elements contained in cometary particulates collected by a spacecraft was conducted with very encouraging results. The technique utilizes a short high intensity burst of laser radiation to vaporize and ionize collected particulate material. Ions extracted from this laser-produced plasma are analyzed in a time of flight mass spectrometer to yield an atomic mass spectrum representative of the relative abundance of elements in the particulates. A prototype analyzer system was designed, constructed, and tested. Results show that: (1) energy-time focus performs as predicted in improving resolution; (2) power densities sufficient to produce usable ionization efficiencies can be obtained; (3) complex alloys such as stainless steel can be analyzed; and (4) a tiny, simple and reliable laser used in the demonstration easily meets spacecraft power and mass limitations. A mass resolution of 150 was experimentally demonstrated at mass 108, and an analytical extrapolation predicts a resolution sufficient to separate masses 250 and 251.

  18. Particulates generated from combustion of polymers (plastics).

    PubMed

    Shemwell, B E; Levendis, Y A

    2000-01-01

    This is an experimental study on the characterization of particulate (soot) emissions from burning polymers. Emissions of polystyrene (PS), polyethylene (PE), polypropylene (PP), polymethyl methacrylate (PMMA), and polyvinyl chloride (PVC) plastics were studied. Combustion took place in a laboratory-scale, electrically heated, drop-tube furnace at temperatures of 1300 and 1500 K, in air. The nominal bulk (global) equivalence ratio, phi, was varied in the range of 0.5-1.5, and the gas residence time in the nearly isothermal radiation zone of the furnace was approximately 1 sec. The particulate emissions were size-classified at the exit of the furnace, using a multi-stage inertial particle impactor. Results showed that both the yields and the size distributions of the emitted soot were remarkably different for the five plastics burned. Soot yields increased with an increasing bulk equivalence ratio. Combustion of PS yielded the highest amounts of soot (most highly agglomerated), several times more than the rest of the polymers. More soot was emitted from PS at 1500 than at 1300 K. Substantial amounts of soot agglomerates were larger than 9 microns. At 1500 and 1300 K, 35 and 29% of the soot mass, respectively, was PM2 (2 microns or smaller). Emissions from PE and PP were remarkably similar to each other. These polymers produced very low emissions at phi < or = 0.5, but emissions increased drastically with phi, and most of the soot was very fine (70-97% of the mass was PM2, depending on phi). Emissions from the combustion of PMMA were comparatively low and were the least influenced by the bulk phi, and 79-95% of the emissions were PM2. Combustion of PVC yielded the lowest amounts of soot; moreover, only 13-34% of the mass was PM2. On a comparative basis, at 1500 K, the following ranges of particulate yields were PM2: 19-75 mg/g of PS, 8-36 mg/g of PE, 1.5-47 mg/g of PP, 11-20 mg/g of PMMA, and 2-8 mg/g of PVC, depending on phi. These comparative results demonstrate that PS produces the highest amounts of fine particulates, followed by PP, PE, and PMMA, and then PVC. Burning these materials with excess oxygen drastically reduces the particulate emissions of PE and PP, substantially reduces those of PS, and mildly reduces those of PMMA and PVC. PMID:10680369

  19. Methods and apparatus for handling or treating particulate material

    NASA Technical Reports Server (NTRS)

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

    2009-01-01

    An improved draft tube spout fluid bed (DTSFB) mixing, handling, conveying, and treating apparatus and systems, and methods for operating are provided. The apparatus and systems can accept particulate material and pneumatically or hydraulically conveying the material to mix and/or treat the material. In addition to conveying apparatus, a collection and separation apparatus adapted to receive the conveyed particulate material is also provided. The collection apparatus may include an impaction plate against which the conveyed material is directed to improve mixing and/or treatment. The improved apparatus are characterized by means of controlling the operation of the pneumatic or hydraulic transfer to enhance the mixing and/or reacting by controlling the flow of fluids, for example, air, into and out of the apparatus. The disclosed apparatus may be used to mix particulate material, for example, mortar; react fluids with particulate material; coat particulate material, or simply convey particulate material.

  20. Estimates of particulate mass in multi-canister overpacks

    SciTech Connect

    SLOUGHTER, J.P.

    1999-02-25

    High, best estimate, and low values are developed for particulate inventories within MCO baskets that have been loaded with freshly cleaned fuel assemblies and scrap. These per-basket estimates are then applied to all anticipated MCO payload configurations to identify which configurations are bounding for each type of particulate. Finally the resulting bounding and nominal values for residual particulates are combined with corresponding values [from other documents] for particulate that may be generated by corrosion of exposed uranium after the fuel has been cleaned. The resulting rounded nominal estimate for a typical MCO after 40 years of storage is 8 kg. The estimate for a bounding total particulate case MCO is that it may contain up to 64 kg of particulate after 40 years of storage.

  1. Method of forming particulate materials for thin-film solar cells

    DOEpatents

    Eberspacher, Chris; Pauls, Karen Lea

    2004-11-23

    A method for preparing particulate materials useful in fabricating thin-film solar cells is disclosed. Particulate materials is prepared by the method include for example materials comprising copper and indium and/or gallium in the form of single-phase, mixed-metal oxide particulates; multi-phase, mixed-metal particulates comprising a metal oxide; and multinary metal particulates.

  2. Spectral properties of ice-particulate mixtures and implications for remote sensing. I - Intimate mixtures

    Microsoft Academic Search

    R. N. Clark; P. G. Lucey

    1984-01-01

    From laboratory spectra of many ice-particulate mixtures with high, medium, and low albedo particulates, the band depths, continuum reflectance, and ratio of band depth to continuum reflectance are derived as a function of the logarithm of thef particulate weight fraction in the sample. Ice band depths are dependent on the particulate albedo, and increase with smaller weight fractions of particulates

  3. Toughening of a Particulate-Reinforced Ceramic-Matrix Composite by Thermal Residual Stress

    Microsoft Academic Search

    Minoru Taya; S. Hayashi; Albert S. Kobayashi; H. S. Yoon

    1990-01-01

    HE primary toughening mechanisms of particulate- T reinforced ceramics have been attributed to (i) interaction between the crack front and particulates (crack front bowing model),'*' (ii) crack deflection by the particulates ahead of a propagating crack (crack deflection model); and (iii) crack bridging by ductile particulates (particulate bridging model).4 Other secondary mechanisms which contribute to the tough- ening of ceramic

  4. X-Ray Absorption Characterization of Diesel Exhaust Particulates

    SciTech Connect

    Nelson, A J; Ferreira, J L; Reynolds, J G; Roos, J W

    1999-11-18

    We have characterized particulates from a 1993 11.1 Detroit Diesel Series 60 engine with electronic unit injectors operated using fuels with and without methylcyclopentadienyl manganese tricarbonyl (MMT) and overbased calcium sulfonate added. X-ray photoabsorption (XAS) spectroscopy was used to characterize the diesel particulates. Results reveal a mixture of primarily Mn-phosphate with some Mn-oxide, and Ca-sulfate on the surface of the filtered particulates from the diesel engine.

  5. A particulate non-specific alkaline phosphatase in Saccharomyces cerevisiae 

    E-print Network

    Mitchell, James Kent

    1980-01-01

    -nahthyl Phosphate Phosphatase in V'M tH' f~SI '. . . . 50 6. Partial Purification of Particulate Alkaline Phosphatase 52 LIST OF FIGURES Figure 1. Titer of an antiserum directed against the soluble Page repressible alkaline phosphatase 26 2 . Electrophoretic...- phatases 35 6. Effect of pH on parti. culate alkaline phosphatase activity 37 7. Effect of substrate concentration of particulate alka- line phosphatase activity 38 8. Molecular weight determination of the particulate al- kaline phosphatase 42 9...

  6. Particulate Matter Emissions from a Coal-Fired Power Plant

    Microsoft Academic Search

    Ping Lu; Jiang Wu; Wei-Ping Pan

    2010-01-01

    Particulate matter emissions of filterable particulate matter (FPM), condensible PM (CPM), PM10, and PM2.5 at FGD inlet and stack in a coal-fired power plant were measured by EPA method 201A and method 202. The results indicated that emissions of total particulate matter (TPM) are 40.99mg\\/m3 and 120.58mg\\/m3, and the filterable PMs are the highest emissions at both sampling locations which

  7. Diesel particulate filter regeneration via resistive surface heating

    DOEpatents

    Gonze, Eugene V; Ament, Frank

    2013-10-08

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

  8. Diesel particulates--what they are and why

    Microsoft Academic Search

    G. A. Amann; D. C. Siegla

    1982-01-01

    The diesel passenger car offers a substantial advantage in fuel economy over its gasoline-powered counterpart, but the long-range future of the diesel in this application is threatened by future federal standards on exhaust particulate emissions. These particulates are primarily combustion-generated, carbonaceous soot in combination with a solvent-extractable hydrocarbon fraction. Particulate production involves an incompletely understood series of phenomena that includes

  9. Electrically heated particulate filter regeneration using hydrocarbon adsorbents

    DOEpatents

    Gonze, Eugene V [Pinckney, MI

    2011-02-01

    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. A grid of electrically resistive material selectively heats exhaust passing through the upstream end to initiate combustion of particulates within the PF. A hydrocarbon adsorbent coating applied to the PF releases hydrocarbons into the exhaust to increase a temperature of the combustion of the particulates within the PF.

  10. Occupational Medicine Implications of Engineered Nanoscale Particulate Matter

    E-print Network

    Kelly, Richard J.

    2008-01-01

    Safety in Nanotechnology Research Occupational Medicinenanotechnology revolution promises dramatic advancements in science, technology, medicineMedicine Implications of Engineered Nanoscale Particulate Matter The emerging nanotechnology

  11. MODELING FINE PARTICULATE MASS AND VISIBILITY USING THE EPA REGIONAL PARTICULATE MODEL

    EPA Science Inventory

    Particulate matter in the atmosphere can adversely impact air quality and human health, as well as significantly affect the environment. articles in the submicrometer size range, when inhaled, may pose certain health hazards. articles in this size range also scatter light, causin...

  12. Electrically heated particulate filter with reduced stress

    DOEpatents

    Gonze, Eugene V.

    2013-03-05

    A system comprises a particulate matter (PM) filter comprising an inlet for receiving exhaust gas. A zoned heater is arranged in the inlet and comprises a resistive heater comprising N zones, where N is an integer greater than one. Each of the N zones comprises M sub-zones, where M is an integer greater than one. A control module selectively activates one of the N zones to initiate regeneration in downstream portions of the PM filter from the one of the N zones and deactivates others of the N zones.

  13. Flight prototype regenerative particulate filter system development

    NASA Technical Reports Server (NTRS)

    Green, D. C.; Garber, P. J.

    1974-01-01

    The effort to design, fabricate, and test a flight prototype Filter Regeneration Unit used to regenerate (clean) fluid particulate filter elements is reported. The design of the filter regeneration unit and the results of tests performed in both one-gravity and zero-gravity are discussed. The filter regeneration unit uses a backflush/jet impingement method of regenerating fluid filter elements that is highly efficient. A vortex particle separator and particle trap were designed for zero-gravity use, and the zero-gravity test results are discussed. The filter regeneration unit was designed for both inflight maintenance and ground refurbishment use on space shuttle and future space missions.

  14. Polarimetric discrimination of atmospheric particulate matter

    NASA Astrophysics Data System (ADS)

    Raman, Prashant; Fuller, Kirk; Gregory, Don

    2012-06-01

    A polarimeter capable of measuring the complete Mueller matrix of highly scattering samples in transmission and reflection from 300 to 1100 nm has been constructed and tested. Exploratory research has been conducted which may lead to the standoff detection of bio-aerosols in the atmosphere. The polarization properties of bsubtilis (surrogate for anthrax spore) have been compared to ambient particulate matter species such as pollen, dust and soot (all sampled onto microscope slides) and differentiating features have been identified. The application of this technique for the discrimination of bio-aerosol from background clutter has been demonstrated.

  15. 30 CFR 7.89 - Test to determine the particulate index.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Humidity correction factor for particulate WF—Weighting factor i-Subscript denoting an individual mode, i=1, . . . n PI—Particulate Index (cfm) (ii) When calculating ambient humidity correction for the particulate concentration (Pf...

  16. 30 CFR 7.89 - Test to determine the particulate index.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Humidity correction factor for particulate WF—Weighting factor i-Subscript denoting an individual mode, i = 1, . . . n PI—Particulate Index (cfm) (ii) When calculating ambient humidity correction for the particulate concentration (Pf...

  17. 30 CFR 7.89 - Test to determine the particulate index.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Humidity correction factor for particulate WF—Weighting factor i-Subscript denoting an individual mode, i=1, . . . n PI—Particulate Index (cfm) (ii) When calculating ambient humidity correction for the particulate concentration (Pf...

  18. 30 CFR 7.89 - Test to determine the particulate index.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Humidity correction factor for particulate WF—Weighting factor i-Subscript denoting an individual mode, i=1, . . . n PI—Particulate Index (cfm) (ii) When calculating ambient humidity correction for the particulate concentration (Pf...

  19. 30 CFR 7.89 - Test to determine the particulate index.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Humidity correction factor for particulate WF—Weighting factor i-Subscript denoting an individual mode, i=1, . . . n PI—Particulate Index (cfm) (ii) When calculating ambient humidity correction for the particulate concentration (Pf...

  20. Mutagenic activity in diesel exhaust particulates

    SciTech Connect

    Nachtman, J.P.; Xiao-bai, X.; Rappaport, S.M.; Talcott, R.E.; Wei, E.T.

    1981-10-01

    Chloroform eluates of diesel exhaust particulate extracts were mutagenic in the Ames test. The mutagenic activity of approximately 480 revertants/100 ..mu..g of extract/plate did not require liver enzymes for its expression. The addition of liver enzymes decreased mutagenic activity, an effect which has previously been shown to be non-specific binding of the mutagen to liver proteins. After reduction of the diesel exhaust extract with sodium borohydride, the S-9 independent activity was greatly diminished. Addition of S-9 to the reduced sample revealed the presence of S-9 dependent mutagenic activity. These results, although not conclusive, provide additional evidence for the presence of nitronarene mutagens in diesel exhaust particulates. If, for example, the samples contained nitrofluorene, nitronaphthalene or nitropyrene, the reduction reaction would have formed aminofluorene, aminonaphthalene, and aminopyrene, compounds which are mutagens requiring liver enzyme activation in the Ames test. Attempts to isolate the amine by acidic extraction were not successful, however, because of the weak mutagenic activity in the sample.

  1. Regeneration of diesel particulate filter using nonthermal plasma without catalyst

    Microsoft Academic Search

    Masaaki Okubo; Takayuki Miyashita; Tomoyuki Kuroki; Shinichi Miwa; Toshiaki Yamamoto

    2004-01-01

    Regulations regarding automotive diesel engine emissions become more severe every year, and it is difficult to meet the requirements with only combustion improvement techniques. More effective post-processing technology is desired especially for particulate matter (PM), such as carbon soots. Although the use of a ceramic diesel particulate filter (DPF) is now a leading technology for PM removal, the problem exists

  2. MODELING ENVIRONMENTAL EXPOSURES TO PARTICULATE MATTER AND PESTICIDES

    EPA Science Inventory

    This presentation describes initial results from on-going research at EPA on modeling human exposures to particulate matter and residential pesticides. A first generation probabilistic population exposure model for Particulate Matter (PM), specifically for predicting PM1o and P...

  3. 40 CFR 86.145-82 - Calculations; particulate emissions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...of particulate determined from the “transient” phase of the cold start test, in...of particulate determined from the “transient” phase of the hot start test, in grams...measured driving distance from the “transient” phase of the cold start test, in...

  4. 40 CFR 86.145-82 - Calculations; particulate emissions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...of particulate determined from the “transient” phase of the cold start test, in...of particulate determined from the “transient” phase of the hot start test, in grams...measured driving distance from the “transient” phase of the cold start test, in...

  5. 40 CFR 86.145-82 - Calculations; particulate emissions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...of particulate determined from the “transient” phase of the cold start test, in...of particulate determined from the “transient” phase of the hot start test, in grams...measured driving distance from the “transient” phase of the cold start test, in...

  6. 40 CFR 86.145-82 - Calculations; particulate emissions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...of particulate determined from the “transient” phase of the cold start test, in...of particulate determined from the “transient” phase of the hot start test, in grams...measured driving distance from the “transient” phase of the cold start test, in...

  7. 40 CFR 86.145-82 - Calculations; particulate emissions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...of particulate determined from the “transient” phase of the cold start test, in...of particulate determined from the “transient” phase of the hot start test, in grams...measured driving distance from the “transient” phase of the cold start test, in...

  8. Preparation of Novel Collagen Sponges Using an Ice Particulate Template

    Microsoft Academic Search

    Young-Gwang Ko; Naoki Kawazoe; Tetsuya Tateishi; Guoping Chen

    2010-01-01

    A new type of collagen sponge was prepared as a tissue engineering scaffold using ice particulates as a template. The sponge has a hierarchical structure of large open pores on the top surface and interconnected small pores in the inner bulk body. The shape, size, and density of the surface large pores were determined by the ice particulates that were

  9. CONTROL OF PARTICULATE EMISSIONS IN THE PRIMARY NONFERROUS METALS INDUSTRIES

    EPA Science Inventory

    The purpose of the symposium on 'Control of Particulate Emissions in the Primary Nonferrous Metals Industries' was to provide a forum for the exchange of knowledge and new ideas on particulate control technology with emphasis on industrial applications of environmental particulat...

  10. Metals in Particulate Pollutants Affect Peak Expiratory Flow of Schoolchildren

    Microsoft Academic Search

    Yun-Chul Hong; Seung-Sik Hwang; Jin Hee Kim; Kyoung-Ho Lee; Hyun-Jung Lee; Kwan-Hee Lee; Seung-Do Yu; Dae-Seon Kim

    2006-01-01

    BACKGROUND: The contribution of the metal components of particulate pollutants to acute respiratory effects has not been adequately evaluated. Moreover, little is known about the effects of genetic polymorphisms of xenobiotic metabolism on pulmonary function. OBJECTIVES: This study was conducted to assess lung function decrement associated with metal components in particulate pollutants and genetic polymorphisms of glutathione S-transferase M1 and

  11. ASSESSMENT OF DIESEL PARTICULATE CONTROL: DIRECT AND CATALYTIC OXIDATION

    EPA Science Inventory

    The report discusses the technology and potential for disposal of diesel particulate by oxidation. Relevant properties of typical diesel particulate are given; note is taken of the small size (on the order of 0.1 micrometer diameter) and the presence of a portion extractable with...

  12. Method for immobilizing particulate materials in a packed bed

    DOEpatents

    Even, Jr., William R. (Livermore, CA); Guthrie, Stephen E. (Livermore, CA); Raber, Thomas N. (Livermore, CA); Wally, Karl (Lafayette, CA); Whinnery, LeRoy L. (Livermore, CA); Zifer, Thomas (Manteca, CA)

    1999-01-01

    The present invention pertains generally to immobilizing particulate matter contained in a "packed" bed reactor so as to prevent powder migration, compaction, coalescence, or the like. More specifically, this invention relates to a technique for immobilizing particulate materials using a microporous foam-like polymer such that a) the particulate retains its essential chemical nature, b) the local movement of the particulate particles is not unduly restricted, c) bulk powder migration and is prevented, d) physical and chemical access to the particulate is unchanged over time, and e) very high particulate densities are achieved. The immobilized bed of the present invention comprises a vessel for holding particulate matter, inlet and an outlet ports or fittings, a loosely packed bed of particulate material contained within the vessel, and a three dimensional porous matrix for surrounding and confining the particles thereby fixing the movement of individual particle to a limited local position. The established matrix is composed of a series of cells or chambers comprising walls surrounding void space, each wall forming the wall of an adjacent cell; each wall containing many holes penetrating through the wall yielding an overall porous structure and allowing useful levels of gas transport.

  13. Method for immobilizing particulate materials in a packed bed

    DOEpatents

    Even, W.R. Jr.; Guthrie, S.E.; Raber, T.N.; Wally, K.; Whinnery, L.L.; Zifer, T.

    1999-02-02

    The present invention pertains generally to immobilizing particulate matter contained in a packed bed reactor so as to prevent powder migration, compaction, coalescence, or the like. More specifically, this invention relates to a technique for immobilizing particulate materials using a microporous foam-like polymer such that (a) the particulate retains its essential chemical nature, (b) the local movement of the particulate particles is not unduly restricted, (c) bulk powder migration and is prevented, (d) physical and chemical access to the particulate is unchanged over time, and (e) very high particulate densities are achieved. The immobilized bed of the present invention comprises a vessel for holding particulate matter, inlet and an outlet ports or fittings, a loosely packed bed of particulate material contained within the vessel, and a three dimensional porous matrix for surrounding and confining the particles thereby fixing the movement of an individual particle to a limited local position. The established matrix is composed of a series of cells or chambers comprising walls surrounding void space, each wall forming the wall of an adjacent cell; each wall containing many holes penetrating through the wall yielding an overall porous structure and allowing useful levels of gas transport. 4 figs.

  14. Particulate emissions from commercial shipping: Chemical, physical, and optical properties

    Microsoft Academic Search

    Daniel A. Lack; James J. Corbett; Timothy Onasch; Brian Lerner; Paola Massoli; Patricia K. Quinn; Timothy S. Bates; Derek Coffman; Berko Sierau; Scott Herndon; James Allan; Tahllee Baynard; Edward Lovejoy; A. R. Ravishankara; Eric Williams

    2009-01-01

    We characterize particulate emissions on the basis of chemical, physical, and optical properties from commercial vessels. Observations during the Texas Air Quality Study\\/Gulf of Mexico Atmospheric Composition and Climate Study 2006 field campaign provide chemical and physical characteristics including sulfate (SO42?) mass, organic matter (OM) mass, black carbon (BC) mass, particulate matter (PM) mass, number concentrations (condensation nuclei (CN) >

  15. PARTICULATE ORGANIC CARBON MEASUREMENTS COLLECTED WITH LOW FLOW PERSONAL SAMPLERS

    EPA Science Inventory

    EPA's National Exposure Research Laboratory and the Research Triangle Institute (RTI) have conducted a particulate matter (PM) personal exposure study in Research Triangle Park, NC. Particulate carbon was sampled with pre-fired quartz filters using low flow PM2.5 samplers (2 L...

  16. KRAFT PULP 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 kraft pulp industry. After a review of available information characterizing particulate emissions from kraft pulp mills, the data were summarized and r...

  17. GRAY IRON FOUNDRY 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 gray iron foundry industry. After a review of available information characterizing particulate emissions from gray iron foundries, the data were summar...

  18. IRON AND STEEL 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 iron and steel industry. After reviewing available information characterizing particulate emissions from iron and steel plants, the data were summarize...

  19. 2009 Final Report: Integrated Science Assessment for Particulate Matter

    EPA Science Inventory

    EPA has released the final Integrated Science Assessment (ISA) for Particulate Matter (PM). This is EPA?s latest evaluation of the scientific literature on the potential human health and welfare effects associated with ambient exposures to particulate matter (PM). The developmen...

  20. DEVELOPMENTS IN PARTICULATE CONTROL FOR COAL-FIRED POWER PLANTS

    EPA Science Inventory

    The paper discusses recent developments in particulate control for coal-fired power plants. The developments are responding to a double challenge to conventional coal-fired power plant emissions control technology: (1) lower particulate emissions require more efficient control de...

  1. Exposure to particulate hexavalent chromium exacerbates allergic asthma pathology

    SciTech Connect

    Schneider, Brent C. [Department of Microbiology, Immunology and Tropical Medicine, The George Washington University, Washington, DC 20037 (United States) [Department of Microbiology, Immunology and Tropical Medicine, The George Washington University, Washington, DC 20037 (United States); Department of Pharmacology and Physiology, The George Washington University, Washington, DC 20037 (United States); Constant, Stephanie L. [Department of Microbiology, Immunology and Tropical Medicine, The George Washington University, Washington, DC 20037 (United States)] [Department of Microbiology, Immunology and Tropical Medicine, The George Washington University, Washington, DC 20037 (United States); Patierno, Steven R. [Department of Pharmacology and Physiology, The George Washington University, Washington, DC 20037 (United States) [Department of Pharmacology and Physiology, The George Washington University, Washington, DC 20037 (United States); GW Cancer Institute, The George Washington University, Washington, DC 20037 (United States); Jurjus, Rosalyn A. [Department of Anatomy and Regenerative Biology, The George Washington University, Washington, DC 20037 (United States)] [Department of Anatomy and Regenerative Biology, The George Washington University, Washington, DC 20037 (United States); Ceryak, Susan M., E-mail: phmsmc@gwumc.edu [Department of Pharmacology and Physiology, The George Washington University, Washington, DC 20037 (United States)

    2012-02-15

    Airborne hexavalent chromate, Cr(VI), has been identified by the Environmental Protection Agency as a possible health threat in urban areas, due to the carcinogenic potential of some of its forms. Particulate chromates are produced in many different industrial settings, with high levels of aerosolized forms historically documented. Along with an increased risk of lung cancer, a high incidence of allergic asthma has been reported in workers exposed to certain inhaled particulate Cr(VI) compounds. However, a direct causal association between Cr(VI) and allergic asthma has not been established. We recently showed that inhaled particulate Cr(VI) induces an innate neutrophilic inflammatory response in BALB/c mice. In the current studies we investigated how the inflammation induced by inhaled particulate Cr(VI) might alter the pathology of an allergic asthmatic response. We used a well-established mouse model of allergic asthma. Groups of ovalbumin protein (OVA)-primed mice were challenged either with OVA alone, or with a combination of OVA and particulate zinc chromate, and various parameters associated with asthmatic responses were measured. Co-exposure to particulate Cr(VI) and OVA mediated a mixed form of asthma in which both eosinophils and neutrophils are present in airways, tissue pathology is markedly exacerbated, and airway hyperresponsiveness is significantly increased. Taken together these findings suggest that inhalation of particulate forms of Cr(VI) may augment the severity of ongoing allergic asthma, as well as alter its phenotype. Such findings may have implications for asthmatics in settings in which airborne particulate Cr(VI) compounds are present at high levels. -- Highlights: ? Allergic asthma correlated with exposure to certain inhaled particulate chromates. ? Direct causal association between Cr(VI) and allergic asthma not established. ? Cr exacerbated pathology and airway hyperresponsiveness in an OVA-challenged mouse. ? Particulate Cr(VI) may augment severity and alter phenotype of ongoing allergic asthma.

  2. The vega particulate shell: comets or asteroids?

    PubMed

    Weissman, P R

    1984-06-01

    The Infrared Astronomical Satellite (IRAS) science team has discovered a shell of particulate material around the star Vega. At the mean distance and temperature of the shell, the expected condensation products from a protostellar nebula would be dominated by frozen volatiles, in particular water ice. It is not possible to discriminate between dirty ice and silicate materials in the Vega shell on the basis of the IRAS data. The Vega shell is probably a ring of cometary bodies with an estimated minimum mass of 15 earth masses, analogous to one that has been hypothesized for the solar system. A possible hot inner shell around Vega may be an asteroid-like belt of material a few astronomical units from the star. PMID:17731997

  3. Infrared spectral behavior of fine particulate solids

    USGS Publications Warehouse

    Hunt, G.R.

    1976-01-01

    Transmission and emission spectra of clouds and layers of fine particulate samples of quartz, magnesium oxide, and aluminum oxide in the 6.5-35-??m wavelength range are presented. They demonstrate that the behavior of layers of particles constitutes a good analogue for a cloud of particles; that individual micrometer-sized particles emit most where they absorb most; that as the size of the particle is increased, the emission features reverse polarity and the spectrum approaches that of one obtained from a polished plate; and that as the particle layer-thickness increases, radiative interaction becomes increasingly important so that the emission maximum shifts from the strongest to weaker features, or produces a maximum at the Christiansen wavelength.

  4. Lanthanides as particulate flow markers in ruminants 

    E-print Network

    Conner, Michael Cronan

    1977-01-01

    or cerium. Tan et al. (1971) used radioruthenium ('osRu) chelated with 1, 10 phenanthr oli ne as a particulate mark r. They found very little ~eaRu adsorb d from the stomach with recovery (97. 4z1. 7/) of the marker recovered in the feces. In vitro... at 50 C and the lanthanide markers then applied. Lartl. . anide I'Iarker Pre aratl'on and Ap~l1cation Cerium-141 ( 4 CeC19 in . 5 N HCI, Sp. Ar t. 1. 89 mCI/II;9 Ce, New Erg land Nuclear) was d11uted to 100 mll with . 5 g Ce(I!109)9. 5Hz0 and . 5 fl...

  5. Impact of Filtration Velocities and Particulate Matter Characteristics on Diesel Particulate Filter Wall Loading Performance

    SciTech Connect

    Lance, Michael J [ORNL; Walker, Larry R [ORNL; Yapaulo, Renato A [ORNL; Orita, Tetsuo [ORNL; Wirojsakunchai, Ekathai [University of Wisconsin; Foster, David [University of Wisconsin; Akard, Michael [Horiba Instruments Inc.

    2009-01-01

    The impact of different types of diesel particulate matter (PM) and different sampling conditions on the wall deposition and early soot cake build up within diesel particulate filters has been investigated. The measurements were made possible by a newly developed Diesel Exhaust Filtration Analysis (DEFA) system in which in-situ diesel exhaust filtration can be reproduced with in small cordierite wafer disks, which are essentially thin sections of a Diesel Particulate Filter (DPF) wall. The different types of PM were generated from selected engine operating conditions of a single-cylinder heavy-duty diesel engine. Two filtration velocities 4 and 8 cm/s were used to investigate PM deep-bed filtration processes. The loaded wafers were then analyzed in a thermal mass analyzer that measures the Soluble Organic Fraction (SOF) as well as soot and sulfate fractions of the PM. In addition, the soot residing in the wall of the wafer was examined under an optical microscope illuminated with Ultraviolet light and an Environmental Scanning Electron Microscope (E-SEM) to determine the bulk soot penetration depth for each loading condition. It was found that higher filtration velocity results in higher wall loading with approximately the same penetration depth into the wall. PM characteristics impacted both wall loading and soot cake layer characteristics. Results from imaging analysis indicate that soot the penetration depth into the wall was affected more by PM size (which changes with engine operating conditions) rather than filtration velocity.

  6. Autonomous Sensing of Particulate Inorganic Carbon Dynamics

    NASA Astrophysics Data System (ADS)

    Weiss, G. A.; Bishop, J. K.; Strubhar, W. D.; Wood, T.

    2011-12-01

    Particulate inorganic carbon (PIC) is produced by coccolithophore phytoplankton and shelled foraminifera and pterpod microzooplankton. These calcite and aragonite particles contribute to excess density of aggregate particles enabling carbon export from surface waters; they are sensitive to the effects of ocean acidification. Concentrations in surface waters range from below 100 nM in oligotrophic waters to 40 uM in the North Atlantic. Very limited ship observations in the Oyashio and subarctic NE Pacific show short term PIC variability of more than one order of magitude over 10 days and 3 months, respectively. At depth concentrations can drop to near zero in waters deeper than the carbonate saturation horizon. Seasonal variations of a factor of two or more at 1000 m depth have been observed. Near surface variability is impossible to follow from ships. We are working on the development of a robust PIC sensor capable of deployment on platforms ranging from CTD's to floats and thus address the gap in observations. The sensor, which uses cross polarized optics, detects the photons that have interacted with birefringent minerals (of which calcite dominates) in the water column. The detection of this very weak signal - which can be 10-6 of the primary beam energy is a daunting task. Here we report results from incomparison deployments of a 'next gen' and prototype sensor during recent expeditions to California coastal and offshore waters (NE Pacific Gyre, Santa Barbara Basin (June 2009); Santa Catalina Basin (October 2010), Santa Cruz Basin (May 2011), California Current and Coastal Waters (July 2011; September 2011). In addition we report calibrations the sensors based on particulate samples filtered from 1L samples and analyzed by HR-ICP-MS.

  7. Assessment of Internal Fabric of Particulate Materials

    NASA Technical Reports Server (NTRS)

    Alshibi, Khalid A.

    2000-01-01

    Particle arrangement and distribution within a soil matrix has long been recognized as having significant influence on the mechanical behavior of cohesionless soils. It is well known that two soil specimens having the same grain type (e.g., quartz, feldspar, etc.), same grain size distribution and relative density (or void ratio) can display completely different mechanical behavior. Because of the different fabric configurations in the otherwise similar specimens, they are likely to have different mechanical properties such as stress-strain response, anisotropy, dilatancy, etc. Soil Fabric is defined as the arrangement of particles, particle groups and associated pore space. In the literature, fabric analysis techniques are mainly classified as destructive (e.g., specimen stabilization, thin-sectioning, and microscopy), and nondestructive techniques (e.g., magnetic resonance imaging, ultrasonic testing, x-ray radiography, and computed tomography). Quantifying the void ratio and its distribution is the main parameter used to describe the fabric of particulate materials. This paper presents a comprehensive literature review of fabric analysis techniques applied to particulate materials. In addition, the results of a comprehensive investigation to quantify void ratio of sand specimens will be presented and discussed. The sand used in the experiments in a natural, uniform rounded to sub-rounded silica sand known as F-75 banding sand with mean particle size of 0.22 mm. Uniform specimens and specimens subjected to different axial-strain levels tested under triaxial and biaxial conditions are examined to evaluate void ratio evolution and its distribution using destructive thin-sectioning and nondestructive Computed Tomography (CT) techniques. Details of a new innovative polygon generation technique called Voronoi tessellation used to quantify void ratio of microscopic images of sand grains will be presented and compared to classical Oda's method. Finally, frequency distribution of void ratio calculated using CT analysis will be presented and discussed.

  8. Health effects of atmospheric particulates: a medical geology perspective.

    PubMed

    Duzgoren-Aydin, Nurdan S

    2008-01-01

    In this review, atmospheric particulates as composite airborne earth materials often containing both natural and anthropogenic components were examined in the context of medical geology. Despite a vast number of both experimental and epidemiological studies confirming the direct and indirect links between atmospheric particulates and human health, the exact nature of mechanisms affecting the particulate-induced pathogenesis largely remains unexplored. Future in depth research on these areas would be most successful if potential mechanisms are examined with reference to the physical (e.g., size, shape and surface), chemical, mineralogical and source characteristics of particulate matters. The underlying goal of this review was to present the relevant terminology and processes proposed in the literature to explain the interfaces and interactions between atmospheric particles and human body within the framework of "atmospheric particle cycles." The complexities of the interactions were demonstrated through case studies focusing on particulate matter air pollution and malignant mesothelioma occurrences due to environmental exposure to erionite-a fibrous zeolite mineral. There is an urgent need for a standard protocol or speciation methods applicable to earth-materials to guide and streamline studies on etiology of mineral-induced diseases. This protocol or speciation methods should provide relevant procedures to determine the level and extent of physical, chemical and mineralogical heterogeneity of particulate matters as well as quantitative in-situ particulate characteristics. PMID:18322866

  9. Particulate contamination removal from wafers using plasmas and mechanical agitation

    DOEpatents

    Selwyn, G.S.

    1998-12-15

    Particulate contamination removal from wafers is disclosed using plasmas and mechanical agitation. The present invention includes the use of plasmas with mechanical agitation for removing particulate matter from the surface of a wafer. The apparatus hereof comprises a mechanical activator, at least one conducting contact pin for transferring the vibration from the activator to the wafer, clamp fingers that maintain the wafer`s position, and means for generating a plasma in the vicinity of the surface of the wafer, all parts of the cleaning apparatus except the mechanical activator and part of the contact pin being contained inside the processing chamber. By exposing a wafer to a plasma and providing motion thereto in a direction perpendicular to its surface, the bonding between the particulate matter and the surface may be overcome. Once free of the wafer surface, the particulates become charged by electrons from the plasma and are drawn into the plasma by attractive forces which keep them from redepositing. The introduction of a flowing gas through the plasma sweeps the particulates away from the wafer and out of the plasma. The entire surface is cleaned during one cleaning step. The use of an rf plasma to accomplish the particulate removal was found to remove more than 90% of the particulates. 4 figs.

  10. Particulate contamination removal from wafers using plasmas and mechanical agitation

    DOEpatents

    Selwyn, Gary S. (Los Alamos, NM)

    1998-01-01

    Particulate contamination removal from wafers using plasmas and mechanical agitation. The present invention includes the use of plasmas with mechanical agitation for removing particulate matter from the surface of a wafer. The apparatus hereof comprises a mechanical activator, at least one conducting contact pin for transferring the vibration from the activator to the wafer, clamp fingers that maintain the wafer's position, and means for generating a plasma in the vicinity of the surface of the wafer, all parts of the cleaning apparatus except the mechanical activator and part of the contact pin being contained inside the processing chamber. By exposing a wafer to a plasma and providing motion thereto in a direction perpendicular to its surface, the bonding between the particulate matter and the surface may be overcome. Once free of the wafer surface, the particulates become charged by electrons from the plasma and are drawn into the plasma by attractive forces which keep them from redepositing. The introduction of a flowing gas through the plasma sweeps the particulates away from the wafer and out of the plasma. The entire surface is cleaned during one cleaning step. The use of an rf plasma to accomplish the particulate removal was found to remove more than 90% of the particulates.

  11. A laser particulate spectrometer for a space simulation facility

    NASA Technical Reports Server (NTRS)

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

    1975-01-01

    A laser particulate spectrometer (LPS) system was developed to measure the size and speed distributions of particulate contaminants. Detection of the particulates is 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 meters/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.

  12. Propellant inefficiency due to particulates in a Pulsed Plasma Thruster

    SciTech Connect

    Spanjers, Gregory G.; Lotspeich, Jason S.; McFall, Keith A.; Spores, Ronald A. [Hughes STX Corporation Edwards AFB, California 93524 (United States); Propulsion Directorate, OL-AC Phillips Laboratory Edwards AFB California 93524 (United States)

    1997-01-10

    Propellant inefficiency resulting from the ejection of propellant material in particulate form is characterized in a Pulsed Plasma Thruster (PPT). Exhaust deposits are collected and analyzed using a combination of Scanning Electron Microscope (SEM), Energy Dispersive X-ray Analysis (EDAX), and microscopic imaging. Teflon particulates are observed with sizes ranging from over 100 {mu}m down to less than 1 {mu}m. Estimates of the mass entrained in this form show that the particulates may account for up to 30% of the total propellant mass used, indicating that methods of ameliorating this loss mechanism would result in significant improvements in the PPT thrust efficiency.

  13. Spectral Properties of Ice-Particulate Mixtures and Implications for Remote Sensing 1. Intimate Mixtures

    Microsoft Academic Search

    Roger N. Clark; Paul G. Lucey

    1984-01-01

    The spectral properties of water ice-particulate mixtures are studied for the purpose of deriving the ice and particulate abundances from remotely obtained spectra (particulates referring to nonicy materials in the form of grains). Reflectance levels and ice absorption band depths are a complex function of the single scattering albedo of the particulates embedded in the ice. The ice absorption band

  14. Copper-dependent Inflammation and Nuclear Factor k B Activation by Particulate Air Pollution

    Microsoft Academic Search

    Thomas Kennedy; Andrew J. Ghio; William Reed; James Samet; John Zagorski; Jacqueline Quay; Jacqueline Carter; Lisa Dailey; John R. Hoidal; Robert B. Devlin

    Particulate air pollution causes increased cardiopulmonary morbidity and mortality, but the chemical de- terminants responsible for its biologic effects are not understood. We studied the effect of total suspended particulates collected in Provo, Utah, an area where an increase in respiratory symptoms in relation to lev- els of particulate pollution has been well documented. Provo particulates caused cytokine-induced neutro- phil

  15. Li2O Particulate Flow Concept, APPLE APEX Interim Report November, 1999

    E-print Network

    California at Los Angeles, University of

    Li2O Particulate Flow Concept, APPLE APEX Interim Report November, 1999 9-1 CHAPTER 9: Li2O PARTICULATE FLOW CONCEPT ­ APPLE DESIGN Contributors Lead Author: Dai Kai Sze Dai Kai Sze, Zhanhe Wang (ANL Particulate Flow Concept, APPLE APEX Interim Report November, 1999 9-2 9. LI2O PARTICULATE FLOW CONCEPT

  16. Discontinuous deformation analysis of particulate media

    NASA Astrophysics Data System (ADS)

    Thomas, Patricia Ann

    Many geotechnical engineering problems involve the localization of deformations along distinct shear planes, such as the response of a layer of soil to displacement along an underlying bedrock fault. Understanding the process of deformation localization and the propagation of shear zones to the surface would aid in the siting of structures near faults, and in developing mitigation techniques. Discrete numerical methods are especially suited to this type of problem, because the discontinuous nature of soil and the kinematics of soil deformation are modeled directly. This research involves the development and validation of Discontinuous Deformation Analysis (DDA), a type of discrete numerical method, as a tool capable of modeling realistic soil behavior, thus providing the foundation for its application to complex soil mechanics problems, such as earthquake fault rupture propagation. First, a review of the two primary types of discrete numerical modeling, the Distinct Element Method (DEM) and DDA is presented along with a discussion of the key aspects of modeling particulate materials with these methods. Next, several extensions to the numerical program Discontinuous Deformation Analysis for Disks (DDAD), implemented during the process of developing DDAD as a tool for modeling particulate materials, were implemented. A flexible, stress-controlled boundary was incorporated, allows simulation of geotechnical biaxial shear tests that are commonly performed on specimens of granular soils. Using this boundary, the stress-strain and volumetric responses of simulated assemblies of particles were investigated. A new type of particle, the disk cluster, was developed and implemented. A disk cluster is a group of circular disks permanently attached to form a single particle. Disk clusters more accurately represent the nonspherical shape of particulate materials, minimize the problem of excessive rotation that occurs with perfectly circular elements, and retain the simplicity of the original contact search routine. A measure of strain for discrete numerical methods was investigated, as the concept of strain defined for a continuum does not apply directly to an assembly of particles with voids that can open and close during deformation. Previous measures of strain were examined and a new approach, the Triangulation Method, is presented. The Triangulation Method calculates strain for a finite element-type mesh overlay that uses the centers of the particles as nodes within the mesh. Nodes are connected with constant strain triangles using a finite strain formulation. The results of a laboratory testing program using glass rods and glass balls are presented. These tests provide valuable insight into the differences in response to mechanical loading of two-dimensional (2D) and three-dimensional (3D) particles, as most discrete numerical models are currently 2D. In addition, the tests on glass rods are used to further validate DDAD. Lastly, the results of a preliminary study of boundary deformation problems using DDAD are presented. Comparison with previous physical and numerical modeling results demonstrate the usefulness of DDAD for this type of geotechnical engineering problem.

  17. Mechanical Properties of Particulate Reinforced Aluminium Alloy Matrix Composite

    SciTech Connect

    Sayuti, M. [Faculty of Engineering, Malikussaleh University of Lhokseumawe, 24300 Aceh (Indonesia); Department of Mechanical and Manufacturing Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Sulaiman, S.; Baharudin, B. T. H. T.; Arifin, M. K. A. [Department of Mechanical and Manufacturing Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Suraya, S.; Vijayaram, T. R.

    2011-01-17

    This paper discusses the mechanical properties of Titanium Carbide (TiC) particulate reinforced aluminium-silicon alloy matrix composite. TiC particulate reinforced LM6 alloy matrix composites were fabricated by carbon dioxide sand molding process with different particulate weight fraction. Tensile strength, hardness and microstructure studies were conducted to determine the maximum load, tensile strength, modulus of elasticity and fracture surface analysis have been performed to characterize the morphological aspects of the test samples after tensile testing. Hardness values are measured for the TiC reinforced LM6 alloy composites and it has been found that it gradually increases with increased addition of the reinforcement phase. The tensile strength of the composites increased with the increase percentage of TiC particulate.

  18. 40 CFR 52.1880 - Control strategy: Particulate matter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...OF IMPLEMENTATION PLANS (CONTINUED) Ohio § 52.1880 Control strategy: Particulate...of this chapter are not met because the Ohio plan does not provide for attainment...Metropolitan Cleveland Intrastate Region and the Ohio portions of the Northwest...

  19. PARTICULATE CONTROL HIGHLIGHTS: RESEARCH ON ELECTROSTATIC PRECIPITATOR TECHNOLOGY

    EPA Science Inventory

    The report gives highlights of a major EPA research program on electrostatic precipitator (ESP) technology, directed toward improving the performance of ESPs in controlling industrial particulate emissions, notably fly ash from coal combustion in electric power plants. Relationsh...

  20. A REAL-TIME MEASURING DEVICE FOR DENSE PARTICULATE SYSTEMS

    EPA Science Inventory

    The report describes the design and performance of an instrument, based on the concept of instantaneous intensity ratio, for measuring particle size distributions of dense particulate matter. The method involves simultaneously measuring the intensity of light scattered by a parti...

  1. CONTINUOUS MEASUREMENT OF DIESEL PARTICULATE EMISSIONS (JOURNAL VERSION)

    EPA Science Inventory

    Evaluation of emerging diesel particulate emissions control technology will require analytical procedures capable of continuous measurement of transient organic and elemental carbon emissions. Procedures based on the flame ionization properties of organic carbon and the opacity o...

  2. Comparative Analysis on the Effects of Diesel Particulate Filter and

    E-print Network

    Wu, Mingshen

    Comparative Analysis on the Effects of Diesel Particulate Filter and Selective Catalytic Reduction (EPA) includePM,NOx,carbonmonoxide(CO),hydrocarbons(HC), ozone (O3), sulfur dioxide (SO2), and lead (Pb

  3. AIR QUALITY CRITERIA FOR PARTICULATE MATTER, VOLUMES I-III

    EPA Science Inventory

    There is no abstract available for these documents. If further information is requested, please refer to the bibliographic citation and contact the Technical Information Staff at the number listed below. Air Quality Criteria for Particulate Matter, Volume I - EP...

  4. 40 CFR 52.2584 - Control strategy; Particulate matter.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...OF IMPLEMENTATION PLANS (CONTINUED) Wisconsin § 52.2584 Control strategy; Particulate...Regulation NR 154.11(7)(b) of Wisconsin Administrative Code (RACT Requirements...1988 and March 30, 1990, the State of Wisconsin submitted committal SIPs for...

  5. 40 CFR 52.2584 - Control strategy; Particulate matter.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...OF IMPLEMENTATION PLANS (CONTINUED) Wisconsin § 52.2584 Control strategy; Particulate...Regulation NR 154.11(7)(b) of Wisconsin Administrative Code (RACT Requirements...1988 and March 30, 1990, the State of Wisconsin submitted committal SIPs for...

  6. 40 CFR 52.2526 - Control strategy: Particulate matter.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...IMPLEMENTATION PLANS (CONTINUED) West Virginia § 52.2526 Control strategy: Particulate matter. (a) EPA approves West Virginia's November 15, 1991 SIP submittal...Act applicable to the Follansbee, West Virginia PM10 nonattainment area. (b)...

  7. 40 CFR 52.2526 - Control strategy: Particulate matter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...IMPLEMENTATION PLANS (CONTINUED) West Virginia § 52.2526 Control strategy: Particulate matter. (a) EPA approves West Virginia's November 15, 1991 SIP submittal...Act applicable to the Follansbee, West Virginia PM10 nonattainment area. (b)...

  8. 40 CFR 52.2429 - Control strategy: Particulate matter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Virginia § 52.2429 Control strategy: Particulate matter. ...Attainment. EPA has determined, as of January 12, 2009, the Virginia portion of the Metropolitan Washington, DC-MD-VA...

  9. 40 CFR 52.2526 - Control strategy: Particulate matter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...IMPLEMENTATION PLANS (CONTINUED) West Virginia § 52.2526 Control strategy: Particulate matter. (a) EPA approves West Virginia's November 15, 1991 SIP submittal...Act applicable to the Follansbee, West Virginia PM10 nonattainment area. (b)...

  10. 40 CFR 52.2429 - Control strategy: Particulate matter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Virginia § 52.2429 Control strategy: Particulate matter. ...Attainment. EPA has determined, as of January 12, 2009, the Virginia portion of the Metropolitan Washington, DC-MD-VA...

  11. 40 CFR 52.2526 - Control strategy: Particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...IMPLEMENTATION PLANS (CONTINUED) West Virginia § 52.2526 Control strategy: Particulate matter. (a) EPA approves West Virginia's November 15, 1991 SIP submittal...Act applicable to the Follansbee, West Virginia PM10 nonattainment area. (b)...

  12. 40 CFR 52.2526 - Control strategy: Particulate matter.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...IMPLEMENTATION PLANS (CONTINUED) West Virginia § 52.2526 Control strategy: Particulate matter. (a) EPA approves West Virginia's November 15, 1991 SIP submittal...Act applicable to the Follansbee, West Virginia PM10 nonattainment area. (b)...

  13. 40 CFR 52.2429 - Control strategy: Particulate matter.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Virginia § 52.2429 Control strategy: Particulate matter. ...Attainment. EPA has determined, as of January 12, 2009, the Virginia portion of the Metropolitan Washington, DC-MD-VA...

  14. EFFECTIVE SAMPLING TECHNIQUES FOR PARTICULATE EMISSIONS FROM ATYPICAL STATIONARY SOURCES

    EPA Science Inventory

    Sampling techniques for measuring particulate emissions from four 'atypical' stationary source categories were developed and evaluated. The categories include low effluent velocity streams, extended dimensions, partially or totally unconfined flow, and saturated gas streams or ga...

  15. Effect of ambient particulate matter expousre on hemostasis

    EPA Science Inventory

    Epidemiological studies have linked levels of particulate matter (PM) in ambient air to cardiovascular mortality and hospitalizations for myocardial infarction (MI) and stroke. Thrombus formation plays a primary role in potentiating acute cardiovascular events, and this study was...

  16. AMBIENT PARTICULATE MATTER DECREASED IN HUMAN ALVEOLAR MACHROPHAGE CYTOKINE RELEASE

    EPA Science Inventory

    Human exposure to ambient airborne particulate matter (PM) is associated with cardiopulmonary mortality and morbidity, including increased hospitalizations for lung infection. Normal lung immune responses to bacterial infection include alveolar macrophage cytokine production and...

  17. 40 CFR 52.2584 - Control strategy; Particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Disapproval—USEPA disapproves Regulation NR 154.11(7)(b) of Wisconsin Administrative Code (RACT Requirements for Coking Operations), which is part of the control strategy to attain and maintain the standards for particulate matter,...

  18. 40 CFR 52.2584 - Control strategy; Particulate matter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Disapproval—USEPA disapproves Regulation NR 154.11(7)(b) of Wisconsin Administrative Code (RACT Requirements for Coking Operations), which is part of the control strategy to attain and maintain the standards for particulate matter,...

  19. ATOC 3500/CHEM 3151 Spring 2014 Particulate Mass and Visibility

    E-print Network

    Toohey, Darin W.

    matter greater? The right (ok, this was a real gimme!) (b) Beer's Law states that the amount of light, and the concentration of absorber (or scatterer) (c) Estimate the amount of particulate matter (in g m-3 ) from

  20. CHARACTERISTICS, DEPOSITION AND FATE OF INHALED PARTICULATE MATTER

    EPA Science Inventory

    Accurate estimates of absorption and fate for particulate matter in the respiratory track are difficult because of complexities in particle composition and morphology. Several deficiencies in information further complicate the ability to make accurate estimates. Available models ...

  1. ULTRAFINE PARTICULATE MATTER EXPOSURE AUGMENTS ISCHEMIA REPERFUSION INJURY IN MICE

    EPA Science Inventory

    Epidemiological studies have linked ambient particulate matter (PM) levels to an increased incidence of adverse cardiovascular events. Yet little is definitively known about the mechanisms accounting for the cardiovascular events associated with PM exposure. The goal of thi...

  2. ULTRAFINE PARTICULATE MATTER EXPOSURE AUGMENTS ISCHEMIA REPERFUSION INJURY IN MICE

    EPA Science Inventory

    Epidemiological studies have linked ambient particulate matter (PM) levels to an increased incidence of adverse cardiovascular events. Yet little is definitively known about the mechanisms accounting for the cardiovascular events associated with PM-exposure. The goal of this stud...

  3. 40 CFR 60.92 - Standard for particulate matter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Hot Mix Asphalt Facilities § 60.92 Standard for particulate matter. (a) On and after the date on which the...

  4. 40 CFR 60.92 - Standard for particulate matter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Hot Mix Asphalt Facilities § 60.92 Standard for particulate matter. (a) On and after the date on which the...

  5. 40 CFR 60.92 - Standard for particulate matter.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Hot Mix Asphalt Facilities § 60.92 Standard for particulate matter. (a) On and after the date on which the...

  6. 40 CFR 60.92 - Standard for particulate matter.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Hot Mix Asphalt Facilities § 60.92 Standard for particulate matter. (a) On and after the date on which the...

  7. 40 CFR 60.92 - Standard for particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Hot Mix Asphalt Facilities § 60.92 Standard for particulate matter. (a) On and after the date on which the...

  8. PARTICULATE MATTER CONCENTRATIONS IN NON-RESIDENTIAL MICROENVIRONMENTS

    EPA Science Inventory

    Exposures to airborne particulate matter (PM) have long been associated with increases in both acute and chronic human health effects. Traditionally, research and regulations have focused on outdoor air pollution. However, human activity pattern studies show that people are ind...

  9. Particulate Hot Gas Stream Cleanup Technical Issues

    SciTech Connect

    Potius, D.; Snyder, T.

    1997-07-01

    The characteristics of entrained particles generated by advanced coal conversion technologies and the harsh flue gas environments from which these particles must be removed challenge current ceramic barrier filtration systems. Measurements have shown that the size distribution, morphology, and chemical composition of particles generated by pressurized fluidized-bed combustion (PFBC) and gasification processes differ significantly from the corresponding characteristics of conventional pulverized-coal ash particles. The entrained particulate matter from these advanced conversion technologies often comprise fine size distributions, irregular particle morphologies, high specific surface areas, and significant proportions of added sorbent material. These characteristics can create high ash cohesivity and high pressure losses through the filter cakes. In addition, the distributions of chemical constituents among the collected particles provide local, highly concentrated chemical species that promote reactions between adjacent particles that ultimately cause strong, nodular deposits to form in the filter vessel. These deposits can lead directly to bridging and filter element failure. This project is designed to address aspects of filter operation that are apparently linked to the characteristics of the collected ash or the performance of the ceramic filter elements. The activities conducted under Task 1, Assessment of Ash Characteristics, are discussed in this paper. Activities conducted under Task 2, Testing and Failure Analysis of Ceramic Filters, are discussed in a separate paper included in the proceedings of the Advanced Coal-Based Power and Environmental Systems `97 Conference. The specific objectives of Task I include the generation of a data base of the key characteristics of Hot Gas Stream Cleanup (HGCU) ashes collected from operating advanced particle filters (APFS) and the identification of relationships between HGCU ash properties and the operation and performance of APFS. During the past year, particulate samples have been characterized from the DOE/FETC Modular Gas Cleanup Rig (MGCR), the Transport Reactor Demonstration Unit (TRDU) located at the University of North Dakota Energy and Environmental Research Center (UNDEERC), the Power Systems Development Facility (PSDF), and gasification studies conducted by Herman Research Pty. Ltd. (HRL) of Melbourne, Australia. This paper discusses these analyses and also presents a coherent mechanism describing how and why consolidated ash deposits form in PFBC filter vessels. This description is based on site observations made at the Tidd PFBC, field and laboratory analyses of ashes and nodules collected from Grimethorpe, Tidd and Karhula, and a review of literature describing eutectic formation, sintering, and consolidation of boiler tube deposits.

  10. Diesel particulate filter (DPF) regeneration by electrical heating of resistive coatings

    DOEpatents

    Williamson, Weldon S. (Malibu, CA); Gonze, Eugene V. (Pinckney, MI)

    2008-12-30

    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 integrally formed in an upstream end 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. A Comparison of Total, Respirable, and Real-Time Airborne Particulate Sampling in Horse Barns

    Microsoft Academic Search

    Frank S. Rosenthal; Alisha Gruntman; Laurent L. Couetil

    2006-01-01

    Measurements of total, respirable, and real-time airborne particulate were obtained in 12 horse barns in summer and winter. Respirable and total particulate concentrations were measured gravimetrically; real-time particulate was measured with an aerosol photometer. Total particulate (TP) ranged from nondetectable (ND) to 2.1 mg\\/m and from ND to 1.2 mg\\/m for winter and summer sampling, respectively. Respirable particulate (RP) ranged

  12. The distribution of particulate aluminum in the Gulf of Mexico

    E-print Network

    Feely, Richard Alan

    1971-01-01

    THE DISTRIBUTION OF PARTICULATE ALUMINUM IN THE GULF OF MEXICO A Thesis RICHARD ALAN FEELY Submitted to the Graduate College of Texas A&M University in partial fulfillment of the reguirement for the degree of MASTER OF SCIENCE May, 1971... Major Subject: Oceanography THE DISTRIBUTION OF PARTICULATE ALUMINUM IN THE GULF OF MEXICO A Thesis by RICHARD ALAN FEELY Approved as to style a d content by: hairma of Committee Head Department (Member) Member) May, 1971 ABSTRACT...

  13. Interaction of non-ideal surfaces in particulate systems

    NASA Astrophysics Data System (ADS)

    Adler, Joshua John

    2001-12-01

    Adhesion between surfaces plays a critical role in the macroscopic behavior of particulate systems such as the flow of cohesive powders, the removal of particulates from substrates, and the formation of particulate coating on host surfaces. Similarly, the repulsive force profile between two particles in suspension influences properties such as rheological behavior and polishing efficiency. The majority of theoretical predictions of surface forces assume that the interface between the particle and surrounding media is ideal. Namely, that there is an atomically sharp demarcation between the properties of the bulk material and the properties of the medium. Furthermore, the interface is often considered perfectly monotonic. While this assumption is likely valid at larger separation distances, significant deviation from theory is expected when two particles are in a contact or near-contact configuration, as they are in adhesion processes or high force operations. This study explores the impact of the non-ideality of surfaces on the adhesion between particulates in dry and humid atmospheres as well as in solution. Specifically, the influence of nanoscale roughness in the range of 0.2 to 20 nm RMS has been investigated on the van der Waals, polar, and capillary forces that bind particulates together or prevent particulate removal from surfaces. Additionally, the influence of transition layers, consisting of chemically modified layers of nanoscale thickness at the interface, on the interaction of particulates in suspension has been delineated. For each of these cases, theoretical predictions are developed and validated through direct measurement of surface forces. The presence of non-ideal interfaces is determined to have a significant impact on the magnitude of the surface force that govern the ensemble behavior of many particulate systems.

  14. Diesel Particulates—What They Are and Why

    Microsoft Academic Search

    Charles A. Amann; Donald C. Siegla

    1981-01-01

    The diesel passenger car offers a substantial advantage in fuel economy over its gasoline-powered counterpart, but the long-range future of the diesel in this application is threatened by future federal standards on exhaust particular emissions. These particulates are primarily combustion-generated carbonaceous soot in combination with a solvent-extractable hydrocarbon fraction. Particulate production involves an incompletely understood series of phenomena that includes

  15. PROCEEDINGS: EIGHTH SYMPOSIUM ON THE TRANSFER AND UTILIZATION OF PARTICULATE CONTROL TECHNOLOGY: VOLUME 2. BAGHOUSES AND PARTICULATE CONTROL FOR NEW APPLICATIONS

    EPA Science Inventory

    The two-volume proceedings describe the latest research and development efforts to improve particulate control devices, while treating traditional concerns of operational cost and compliance. (overall, particulate control remains a key issue in the cost and applicability of furna...

  16. PROCEEDINGS: EIGHTH SYMPOSIUM ON THE TRANSFER AND UTILIZATION OF PARTICULATE CONTROL TECHNOLOGY - VOLUME 2. BAGHOUSES AND PARTICULATE CONTROL FOR NEW APPLICATIONS

    EPA Science Inventory

    The two-volume proceedings describe the latest research and development efforts to improve particulate control devices, while treating traditional concerns of operational cost and compliance. Overall, particulate control remains a key issue in the cost and applicability of furnac...

  17. Adverse Health Effects of Particulate Air Pollution

    PubMed Central

    Bell, Michelle L.; Ebisu, Keita; Peng, Roger D.; Dominici, Francesca

    2011-01-01

    Background The short-term effects of particulate matter (PM) on mortality and morbidity differ by geographic location and season. Several hypotheses have been proposed for this variation, including different exposures with air conditioning (AC) versus open windows. Methods Bayesian hierarchical modeling was used to explore whether AC prevalence modified day-to-day associations between PM10 and mortality, and between PM2.5 and cardiovascular or respiratory hospitalizations, for those 65 years and older. We considered yearly, summer-only, and winter-only effect estimates and 2 types of AC (central and window units). Results Communities with higher AC prevalence had lower PM effects. Associations were observed for cardiovascular hospitalizations and central AC. Each additional 20% of households with central AC was associated with a 43% decrease in PM2.5 effects on cardiovascular hospitalization. Central AC prevalence explained 17% of between-community variability in PM2.5 effect estimates for cardiovascular hospitalizations. Conclusions Higher AC prevalence was associated with lower health effect estimates for PM. PMID:19535984

  18. Lanthanoid geochemistry of urban atmospheric particulate matter.

    PubMed

    Moreno, Teresa; Querol, Xavier; Alastuey, Andrés; Pey, Jorge; Minguillón, Maria Cruz; Pérez, Noemi; Bernabé, Rosa M; Blanco, Salvador; Cárdenas, Beatriz; Gibbons, Wes

    2008-09-01

    Relatively little is known about the lanthanoid element (La to Lu) chemistry of inhalable urban atmospheric particulate matter (PM). PM samples collected during an air sampling campaign in the Mexico City area contain lanthanoid concentrations of mostly 1-10 ng m(-3), increasing with mass where resuspension of crustal PM is important (low PM2.5/PM10), but not where fine emissions from traffic and industry dominate (high PM2.5/ PM10). Samples show anthropogenic enrichment of lighter over heavier lanthanoids, and Ce enrichment relative to La and Sm occurs in the city center (especially PM10) possibly due to PM from road vehicle catalytic converters. La is especially enriched, although many samples show low La/V values (< 0.11), suggesting the dominating influence of fuel oil combustion sources rather than refinery emissions. We use La/Sm v La/ Ce, LaCeSm, and LaCeV plots to compare Mexico City aerosols with PM from other cities. Lanthanoid aerosol geochemistry can be used not only to identify refinery pollution events, but also as a marker for different hydrocarbon combustion emissions (e.g., oil or coal power stations) on urban background atmospheric PM. PMID:18800521

  19. PARTICULATE EMISSION ABATEMENT FOR KRAKOW BOILERHOUSES

    SciTech Connect

    Bruce H. Easom; Leo A, Smolensky; S. Ronald Wysk; Jan Surowka; Miroslaw Litke; Jacek Ginter

    1998-09-30

    A U.S./Polish Bilateral Steering Committee (BSC) and the Department of Energy (DOE) selected LSR Technologies, Inc. as a contractor to participate in the Krakow Clean Fuels and Energy Efficiency Program. The objective of this program was the formation of business ventures between U.S. and Polish firms to provide equipment and services to reduce air emissions in the city of Krakow. A cooperative agreement was entered into by DOE and LSR to begin work in April 1994 involving implementation of particulate control technology called a Core Separator{trademark} for coal-fueled boilerhouses in the city. The major work tasks included: (1) conducting a market analysis, (2) completion of a formal marketing plan, (3) obtaining patent protection within Poland, (4) selecting a manufacturing partner, and (5) completing a demonstration unit and commercial installations. In addition to work performed by LSR Technologies, key contributors to this project were (1) the Polish Foundation for Energy Efficiency (FEWE), a non-profit consulting organization specializing in energy and environmental-related technologies, and (2) EcoInstal, a privately held Polish company serving the air pollution control market. As the project concluded in late 1998, five (5) Core Separator{trademark} installations had been implemented in the city of Krakow, while about 40 others were completed in other regions of Poland.

  20. Gene-particulate matter-health interactions

    SciTech Connect

    Kleeberger, Steven R. [Laboratory of Respiratory Biology, Environmental Genetics Group, National Institute of Environmental Health Sciences, National Institutes of Health, 111 T.W. Alexander Drive, Building 101, Room D240, Research Triangle Park, NC 27705 (United States)]. E-mail: kleeber1@niehs.nih.gov; Ohtsuka, Yoshinori [Department of Pulmonary Medicine, Fukushima Medical University, Fukushima (Japan)

    2005-09-01

    Inter-individual variation in human responses to air pollutants suggests that some subpopulations are at increased risk to the detrimental effects of pollutant exposure. Extrinsic factors such as previous exposure and nutritional status may influence individual susceptibility. Intrinsic (host) factors that determine susceptibility include age, gender, and pre-existing disease (e.g., asthma), and it is becoming clear that genetic background also contributes to individual susceptibility. Environmental exposures to particulates and genetic factors associated with disease risk likely interact in a complex fashion that varies from one population and one individual to another. The relationships between genetic background and disease risk and severity are often evaluated through traditional family-based linkage studies and positional cloning techniques. However, case-control studies based on association of disease or disease subphenotypes with candidate genes have advantages over family pedigree studies for complex disease phenotypes. This is based in part on continued development of quantitative analysis and the discovery and availability of simple sequence repeats and single nucleotide polymorphisms. Linkage analyses with genetically standardized animal models also provide a useful tool to identify genetic determinants of responses to environmental pollutants. These approaches have identified significant susceptibility quantitative trait loci on mouse chromosomes 1, 6, 11, and 17. Physical mapping and comparative mapping between human and mouse genomes will yield candidate susceptibility genes that may be tested by association studies in human subjects. Human studies and mouse modeling will provide important insight to understanding genetic factors that contribute to differential susceptibility to air pollutants.

  1. PREFACE TO SPECIAL SECTION ON PARTICULATE MATTER: ATMOSPHERIC SCIENCES, EXPOSURE, AND THE FOURTH COLLOQUIUM ON PARTICULATE MATTER AND HUMAN HEALTH

    EPA Science Inventory

    In response to epidemiological studies published over twenty years ago, at least three research communities have been intensively studying airborne particulate matter (PM). These efforts have been coordinated by approaching the source - atmospheric accumulation/receptor - exposu...

  2. Microwave-Regenerated Diesel Exhaust Particulate Filter

    SciTech Connect

    Nixdorf, Richard D. (Industrial Ceramic Solution, LLC); Green, Johney Boyd; Story, John M.; Wagner, Robert M. (Oak Ridge National Laboratory)

    2001-03-05

    Development of a microwave-regenerated particulate filter system has evolved from bench scale work to actual diesel engine experimentation. The filter system was initially evaluated on a stationary mounted 1.2-L diesel engine and was able to remove a significant amount of carbon particles from the exhaust. The ability of the microwave energy to regenerate or clean the filter was also demonstrated on this engine under idle conditions. Based on the 1.2-L experiments, improvements to the filter design and materials were implemented and the system was re-evaluated on a vehicle equipped with a 7.3-L diesel engine. The 7.3-L engine was selected to achieve heavy filter loading in a relatively short period of time. The purpose of these experiments was to evaluate filter-loading capacity, power requirements for regeneration, and filter regeneration efficiency. A more detailed evaluation of the filter was performed on a stationary mounted 1.9-L diesel engine. The effect of exhaust flow rate, loading, transients, and regeneration on filter efficiency was evaluated with this setup. In addition, gaseous exhaust emissions were investigated with and without an oxidation catalyst on the filter cartridge during loading and regeneration. (SAE Paper SAE-2001-01-0903 © 2001 SAE International. This paper is published on this website with permission from SAE International. As a user of this website, you are permitted to view this paper on-line, download this pdf file and print one copy of this paper at no cost for your use only. The downloaded pdf file and printout of this SAE paper may not be copied, distributed or forwarded to others or for the use of others.)

  3. Semivolatile Particulate Organic Material Southern Africa during SAFARI 2000

    NASA Technical Reports Server (NTRS)

    Eatough, D. J.; Eatough, N. L.; Pang, Y.; Sizemore, S.; Kirchstetter, T. W.; Novakov, T.

    2005-01-01

    During August and September 2000, the University of Washington's Cloud and Aerosol Research Group (CARG) with its Convair-580 research aircraft participated in the Southern African Fire-Atmosphere Research Initiative (SAFARI) 2000 field study in southern Africa. Aboard this aircraft was a Particle Concentrator-Brigham Young University Organic Sampling System (PC-BOSS), which was used to determine semivolatile particulate material with a diffusion denuder sampler. Denuded quartz filters and sorbent beds in series were used to measure nonvolatile and semivolatile materials, respectively. Results obtained with the PC-BOSS are compared to those obtained with conventional quartz-quartz and Teflon-quartz filter pack samplers. Various 10-120 min integrated samples were collected during flights through the h e troposphere, in the atmospheric boundary layer, and in plumes from savanna fires. Significant fine particulate semivolatile organic compounds (SVOC) were found in all samples. The SVOC was not collected by conventional filter pack samplers and therefore would not have been determined in previous studies that used only filter pack samplers. The SVOC averaged 24% of the fine particulate mass in emissions from the fires and 36% of the fine particulate mass in boundary layer samples heavily impacted by aged emissions from savanna fires. Concentrations of fine particulate material in the atmospheric mixed layer heavily impacted by aged savanna frre emissions averaged 130 micrograms per cubic meter. This aerosol was 85% carbonaceous mated.

  4. Particulate control for low rank coals

    SciTech Connect

    Touzel, R.McD.

    1993-12-31

    The power generating system in Victoria currently comprises a total capacity of 6650 MW. Eighty percent of this capacity consists of base load stations in the Latrobe Valley using brown coal. The Latrobe Valley brown coals have unique characteristics with high moisture content ranging from 58 percent to 70 percent and an ash content which is relatively low but very variable in nature. These and other factors associated with the coal have caused special problems in handling and combustion of the coal and the de-dusting of the boiler flue gases. In recent years, this has been the basis for the design parameters adopted for all the plants in the system. With respect to flue gas de-dusting, the SECV has carried out extensive laboratory studies to characterize the different ashes obtained from the Latrobe Valley brown coals, including precipitability and aerodynamic tests. It also carried out full-scale tests on operating plants and pilot tests have been conducted on inertial collectors, precipitators and bag filters. The Environmental Protection Authority of Victoria has established a particulate emission level of 0.150 grams/m{sup 3} n.t.p. dry for recent Latrobe Valley boilers. However, the mandated emission level takes into account wide variations in operating conditions, and the plants normally achieve much lower emission levels. The Latrobe Valley plants presently in operation include Yallourn W (2x350 MW + 2x375 MW), Morwell (170 MW total and briquette factory), Hazelwood (8x200 MW) and Loy Yang (4x500 MW). The Yalloum W boilers are supplied with coal from the Yalloum Open Cut, the Morwell and Hazelwood boilers from the Morwell Open Cut and Loy Yang boilers from the Loy Yang Open Cut. All boilers are pulverized coal fired (PCF) and incorporate special firing equipment to enable the as-mined wet coal to be fired directly into the furnaces. All boilers are fitted with electrostatic precipitators. The locations of the stations and open cuts are shown.

  5. Particulate matter as an amplifier for astronomical light pollution

    NASA Astrophysics Data System (ADS)

    ?ci??or, T.; Kubala, M.

    2014-11-01

    In this paper, we state that the main factor that influences seasonal changes in the brightness of the cloudless, moonless, light-polluted night sky is primarily particulate matter, emitted mainly from low-emission sources, especially in winter. This effect is particularly noticeable in Cracow and its surroundings, one of the places in Europe that is most polluted by particulate matter. Measurements taken over a period of one year have allowed us to show a linear relationship between the concentration of particulate matter and the brightness of the clear, cloudless night sky. We have also found similar correlations in other, industrialized areas of Poland, as well as at the Mount Suhora Astronomical Observatory. We believe that the factor described here should be taken into account when planning the construction of new astronomical observatories, especially those located near large urban areas.

  6. Cometary particulate analyzer. [mass spectrometry of laser plasmas

    NASA Technical Reports Server (NTRS)

    Friichtenicht, J. F.; Miller, D. J.; Utterback, N. G.

    1979-01-01

    A concept for determining the relative abundance of elements contained in cometary particulates was evaluated. The technique utilizes a short, high intensity burst of laser radiation to vaporize and ionize collected particulate material. Ions extracted from this laser produced plasma are analyzed in a time of flight mass spectrometer to yield an atomic mass spectrum representative of the relative abundance of elements in the particulates. Critical aspects of the development of this system are determining the ionization efficiencies for various atomic species and achieving adequate mass resolution. A technique called energy-time focus, which utilizes static electric fields to alter the length of the ion flight path in proportion to the ion initial energy, was used which results in a corresponding compression to the range of ion flight times which effectively improves the inherent resolution. Sufficient data were acquired to develop preliminary specifications for a flight experiment.

  7. Source and occurrence of particulate lead in tap water.

    PubMed

    Deshommes, Elise; Laroche, Laurent; Nour, Shokoufeh; Cartier, Clément; Prévost, Michèle

    2010-06-01

    Lead samples were collected at the tap from homes with lead service lines (LSLs) in a full-scale utility using both random daytime (RDT) and particulate stimulation sampling (PSS) protocols. Analysis of the results revealed two sources and occurrences of particulate lead. A first source is due to corrosion of lead-bearing elements in the premise plumbing (PP) and occurs mostly at low to moderate concentrations < 3 microg/L, with some sporadic higher concentrations (4-12 microg/L). These spikes were consistently observed and considerably increased using PSS, showing that current sampling protocols may miss a significant portion of particulate lead. The second source results from the adsorption of dissolved lead onto iron deposits in LSL/PP, and is continuously present at low to moderate concentrations. Statistical analyses were validated by physical analyses of: (i) lead scales from LSLs; and (ii) lead particles from tap aerators. PMID:20546838

  8. Particulate extraction arrangement for automotive turbocharger or the like

    SciTech Connect

    Ishida, N.; Kato, N.; Kawamura, M.

    1988-08-16

    This patent describes an engine system including an exhaust manifold; a turbocharger having a scroll into which exhaust gas from the engine is introduced; a valve for selectively by-passing exhaust gases from the manifold around the scroll into an exhaust conduit; and a particulate separation device operatively interposed between the exhaust manifold, the scroll and the valve, the separation device comprising; a chamber; a first port which establishes fluid communication between the chamber and the manifold; a second port, the second port establishing fluid communication between the chamber and the scroll; and a third port, the third port establishing fluid communication between the chamber and the exhaust conduit via the valve; the chamber including means for inducing particulate matter which is carried thereinto from the manifold through the first port to separate from the exhaust gases and gravitate toward the third port and for inducing particulate matter free exhaust gases to pass through the second port.

  9. Method and apparatus for injecting particulate media into the ground

    DOEpatents

    Dwyer, Brian P.; Dwyer, Stephen F.; Vigil, Francine S.; Stewart, Willis E.

    2004-12-28

    An improved method and apparatus for injecting particulate media into the ground for constructing underground permeable reactive barriers, which are used for environmental remediation of subsurface contaminated soil and water. A media injector sub-assembly attached to a triple wall drill string pipe sprays a mixture of active particulate media suspended in a carrier fluid radially outwards from the sub-assembly, at the same time that a mixing fluid is sprayed radially outwards. The media spray intersects the mixing spray at a relatively close distance from the point of injection, which entrains the particulate media into the mixing spray and ensures a uniform and deep dispersion of the active media in the surrounding soil. The media injector sub-assembly can optionally include channels for supplying compressed air to an attached down-the-hole hammer drive assembly for use during drilling.

  10. Biodiesel Fuel Property Effects on Particulate Matter Reactivity

    SciTech Connect

    Williams, A.; Black, S.; McCormick, R. L.

    2010-06-01

    Controlling diesel particulate emissions to meet the 2007 U.S. standard requires the use of a diesel particulate filter (DPF). The reactivity of soot, or the carbon fraction of particulate matter, in the DPF and the kinetics of soot oxidation are important in achieving better control of aftertreatment devices. Studies showed that biodiesel in the fuel can increase soot reactivity. This study therefore investigated which biodiesel fuel properties impact reactivity. Three fuel properties of interest included fuel oxygen content and functionality, fuel aromatic content, and the presence of alkali metals. To determine fuel effects on soot reactivity, the performance of a catalyzed DPF was measured with different test fuels through engine testing and thermo-gravimetric analysis. Results showed no dependence on the aromatic content or the presence of alkali metals in the fuel. The presence and form of fuel oxygen was the dominant contributor to faster DPF regeneration times and soot reactivity.

  11. Metals in Particulate Pollutants Affect Peak Expiratory Flow of Schoolchildren

    PubMed Central

    Hong, Yun-Chul; Hwang, Seung-Sik; Kim, Jin Hee; Lee, Kyoung-Ho; Lee, Hyun-Jung; Lee, Kwan-Hee; Yu, Seung-Do; Kim, Dae-Seon

    2007-01-01

    Background The contribution of the metal components of particulate pollutants to acute respiratory effects has not been adequately evaluated. Moreover, little is known about the effects of genetic polymorphisms of xenobiotic metabolism on pulmonary function. Objectives This study was conducted to assess lung function decrement associated with metal components in particulate pollutants and genetic polymorphisms of glutathione S-transferase M1 and T1. Methods We studied 43 schoolchildren who were in the 3rd to 6th grades. Each student measured peak expiratory flow rate three times a day for 42 days. Particulate air concentrations were monitored every day, and the concentrations of iron, manganese, lead, zinc, and aluminum in the particles were measured. Glutathione S-transferase M1 and T1 genetic polymorphisms were determined using DNA extracted from participant buccal washings. We used a mixed linear regression model to estimate the association between peak expiratory flow rate and particulate air pollutants. Results We found significant reduction in the peak expiratory flow rate after the children’s exposure to particulate pollutants. The effect was shown most significantly 1 day after exposure to the ambient particles. Manganese and lead in the particles also reduced the peak expiratory flow rate. Genetic polymorphisms of glutathione S-transferase M1 and T1 did not significantly affect peak expiratory flow rate. Conclusions This study demonstrated that particulate pollutants and metals such as manganese and lead in the particles are associated with a decrement of peak expiratory flow rate. These effects were robust even with consideration of genetic polymorphisms of glutathione S-transferase. PMID:17431494

  12. Atmospheric particulates in a semi-rural environment 

    E-print Network

    Klein, Thomas Kelly

    1974-01-01

    connotation is that a pollutant is potentially deleterious. " Air pollution consists of two distinct classes, gaseous and particulate. Early notice of air pollution usually is due to smoke, smog, and haze, These consist of visible atmospheric particulates.... AEROSOL INTNNC GALINNATION LIGHT CltOPPEA SIC H ll 0 L T I tl E SUPPO 0. 0 VOLT DC SNPILT LAMP ADJUS1 PHOTO TUSE FILTER VALVE FILTER PUltP FLDW RATE URN UAI, SCAR PREAVRIFIElt CATNODE FOI. LOVES II I II U I E S ANPLIFIER AO 00...

  13. Particulate Emissions Hazards Associated with Fueling Heat Engines

    NASA Technical Reports Server (NTRS)

    Hendricks, Robert C.; Bushnell, Dennis M.

    2010-01-01

    All hydrocarbon- (HC-) fueled heat engine exhaust (tailpipe) emissions (<10 to 140 nm) contribute as health hazards, including emissions from transportation vehicles (e.g., aircraft) and other HC-fueled power systems. CO2 emissions are tracked, and when mapped, show outlines of major transportation routes and cities. Particulate pollution affects living tissue and is found to be detrimental to cardiovascular and respiratory systems where ultrafine particulates directly translocate to promote vascular system diseases potentially detectable as organic vapors. This paper discusses aviation emissions, fueling, and certification issues, including heat engine emissions hazards, detection at low levels and tracking of emissions, and alternate energy sources for general aviation.

  14. INSTRUMENTATION FOR MONITORING THE OPACITY OF PARTICULATE EMISSIONS CONTAINING CONDENSED WATER

    EPA Science Inventory

    On-stack instrumentation and methodology were developed to monitor the opacity of particulate pollutants in stationary source emissions containing condensed water. The instrument continuously extracts and measures the opacity of representative samples of particulate effluent. It ...

  15. The Role of Particulate Matter in the Development of Hypoxia on the Texas-Louisiana Shelf

    E-print Network

    Cochran, Emma Mary

    2013-07-31

    Controlling Hypoxia program (hypoxia.tamu.edu). Discrete samples of particulate matter (PM) and particulate organic carbon (POC) concentration were obtained for analysis and calibration of optical instruments interfaced with a profiling CTD, a towed undulating...

  16. 75 FR 45075 - Federal Implementation Plans To Reduce Interstate Transport of Fine Particulate Matter and Ozone

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-02

    ...Particulate Matter and Ozone'' (Transport Rule) which is published...regarding EPA's proposed Transport Rule, which identifies and limits emissions of nitrogen oxides and...Plans to Reduce Interstate Transport of Fine Particulate...

  17. PROCEEDINGS: EIGHTH SYMPOSIUM ON THE TRANSFER AND UTILIZATION OF PARTICULATE CONTROL TECHNOLOGY - VOLUME 1. ELECTROSTATIC PRECIPITATORS

    EPA Science Inventory

    The two-volume proceedings describe the latest research and development efforts to improve particulate control devices, while treating traditional concerns of operational cost and compliance. Overall, particulate control remains a key issue in the cost and applicability of furnac...

  18. PROCEEDINGS: EIGHTH SYMPOSIUM ON THE TRANSFER AND UTILIZATION OF PARTICULATE CONTROL TECHNOLOGY: VOLUME 1. ELECTROSTATIC PRECIPITATORS

    EPA Science Inventory

    The two-volume proceedings describe the latest research and development efforts to improve particulate control devices, while treating traditional concerns of operational cost and compliance. (overall, particulate control remains a key issue in the cost and applicability of furna...

  19. 40 CFR 86.137-90 - Dynamometer test run, gaseous and particulate emissions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Dynamometer test run, gaseous and particulate emissions. ...Otto-Cycle Complete Heavy-Duty Vehicles; Test Procedures § 86.137-90 Dynamometer test run, gaseous and particulate emissions....

  20. 40 CFR 86.137-90 - Dynamometer test run, gaseous and particulate emissions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Dynamometer test run, gaseous and particulate emissions. ...Otto-Cycle Complete Heavy-Duty Vehicles; Test Procedures § 86.137-90 Dynamometer test run, gaseous and particulate emissions....

  1. 40 CFR 86.137-90 - Dynamometer test run, gaseous and particulate emissions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Dynamometer test run, gaseous and particulate emissions. ...Otto-Cycle Complete Heavy-Duty Vehicles; Test Procedures § 86.137-90 Dynamometer test run, gaseous and particulate emissions....

  2. 40 CFR 86.137-94 - Dynamometer test run, gaseous and particulate emissions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Dynamometer test run, gaseous and particulate emissions. ...Otto-Cycle Complete Heavy-Duty Vehicles; Test Procedures § 86.137-94 Dynamometer test run, gaseous and particulate emissions....

  3. 40 CFR 86.137-94 - Dynamometer test run, gaseous and particulate emissions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Dynamometer test run, gaseous and particulate emissions. ...Otto-Cycle Complete Heavy-Duty Vehicles; Test Procedures § 86.137-94 Dynamometer test run, gaseous and particulate emissions....

  4. 40 CFR 86.137-90 - Dynamometer test run, gaseous and particulate emissions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Dynamometer test run, gaseous and particulate emissions. ...Otto-Cycle Complete Heavy-Duty Vehicles; Test Procedures § 86.137-90 Dynamometer test run, gaseous and particulate emissions....

  5. CONTRIBUTION OF SEMI-VOLATILE PARTICULATE MATTER TO AMBIENT SUSPENDED FINE PARTICLE MASS

    EPA Science Inventory

    Scope: The periodic (5 years) review of the National Ambient Air Quality Standard (NAAQS) for particulate matter (PM) and the subsequent determination by EPA and NAS of particulate matter research needs have identified areas of uncertainty including exposure measurement th...

  6. STATISTICAL ISSUES IN THE STUDY OF AIR POLLUTION INVOLVING AIRBORNE PARTICULATE MATTER

    EPA Science Inventory

    Epidemiological research in the early 1990s focusing on health effects of airborne particulate matter pointed to a statistical association between increases in concentration of particulate in ambient air and increases in daily nonaccidental mortality, particularly among the eld...

  7. OPERATION AND MAINTENANCE OF PARTICULATE CONTROL DEVICES ON COAL-FIRED UTILITY BOILERS

    EPA Science Inventory

    The report discusses the control of fine particulate from coal-fired utility boilers, using electrostatic precipitators (ESPs), wet scrubbers, and fabric filters. It provides guidelines to utility personnel, responsible for selecting fine particulate control equipment, on signifi...

  8. 40 CFR 52.1604 - Control strategy and regulations: Total suspended particulates.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...false Control strategy and regulations: Total suspended particulates. 52.1604...1604 Control strategy and regulations: Total suspended particulates. (a...Company's B.L. England Generating Station are limited to an emission rate...

  9. DETERMINATION OF BENZIDINE, RELATED CONGENERS, AND PIGMENTS IN ATMOSPHERIC PARTICULATE MATTER

    EPA Science Inventory

    Methods for the determination of benzidine, related congeners, and pigments in atmospheric particulate matter, based on high performance liquid chromatography, are described. The methods are evaluated using National Bureau of Standards atmospheric particulate matter, as well as f...

  10. 40 CFR 92.117 - Gas meter or flow instrumentation calibration, particulate measurement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...false Gas meter or flow instrumentation calibration, particulate...PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM LOCOMOTIVES...117 Gas meter or flow instrumentation calibration, particulate...use of gas meters or flow instrumentation to determine flow...

  11. 40 CFR 92.117 - Gas meter or flow instrumentation calibration, particulate measurement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...false Gas meter or flow instrumentation calibration, particulate...PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM LOCOMOTIVES...117 Gas meter or flow instrumentation calibration, particulate...use of gas meters or flow instrumentation to determine flow...

  12. 40 CFR 92.117 - Gas meter or flow instrumentation calibration, particulate measurement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...false Gas meter or flow instrumentation calibration, particulate...PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM LOCOMOTIVES...117 Gas meter or flow instrumentation calibration, particulate...use of gas meters or flow instrumentation to determine flow...

  13. 40 CFR 92.117 - Gas meter or flow instrumentation calibration, particulate measurement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...true Gas meter or flow instrumentation calibration, particulate...PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM LOCOMOTIVES...117 Gas meter or flow instrumentation calibration, particulate...use of gas meters or flow instrumentation to determine flow...

  14. 40 CFR 227.32 - Liquid, suspended particulate, and solid phases of a material.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Liquid, suspended particulate, and solid phases of a material. 227.32 Section... Liquid, suspended particulate, and solid phases of a material. (a) For...to centrifugation and filtration. The solid phase includes all material settling...

  15. 40 CFR 52.1278 - Control strategy: Sulfur oxides and particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Control strategy: Sulfur oxides and particulate matter. 52.1278 Section 52.1278... Mississippi § 52.1278 Control strategy: Sulfur oxides and particulate matter. In a letter dated...

  16. 40 CFR 52.1278 - Control strategy: Sulfur oxides and particulate matter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Control strategy: Sulfur oxides and particulate matter. 52.1278 Section 52.1278... Mississippi § 52.1278 Control strategy: Sulfur oxides and particulate matter. In a letter dated...

  17. 40 CFR 52.2678 - Control strategy and regulations: Particulate matter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Control strategy and regulations: Particulate matter. 52.2678 Section 52.2678...CONTINUED) Guam § 52.2678 Control strategy and regulations: Particulate matter. (a) The requirements...

  18. 40 CFR 52.2678 - Control strategy and regulations: Particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Control strategy and regulations: Particulate matter. 52.2678 Section 52.2678...CONTINUED) Guam § 52.2678 Control strategy and regulations: Particulate matter. (a) The requirements...

  19. PREPARATION AND CHARACTERIZATION OF FINELY DIVIDED PARTICULATE ENVIRONMENTAL CONTAMINANTS FOR BIOLOGICAL EXPERIMENTS

    EPA Science Inventory

    The purpose of this project was to provide a centralized source for the preparation and characterization of selected particulate materials for biological experiments. The particulate materials of interest were a range of environmental contaminants known or suspected to detrimenta...

  20. Pulmonary particulate matter and systemic microvascular dysfunction.

    PubMed

    Nurkiewicz, Timothy R; Porter, Dale W; Hubbs, Ann F; Stone, Samuel; Moseley, Amy M; Cumpston, Jared L; Goodwill, Adam G; Frisbee, Stephanie J; Perrotta, Peter L; Brock, Robert W; Frisbee, Jefferson C; Boegehold, Matthew A; Frazer, David G; Chen, Bean T; Castranova, Vincent

    2011-12-01

    Pulmonary particulate matter (PM) exposure has been epidemiologically associated with an increased risk of cardiovascular morbidity and mortality, but the mechanistic foundations for this association are unclear. Exposure to certain types of PM causes changes in the vascular reactivity of several macrovascular segments. However, no studies have focused upon the systemic microcirculation, which is the primary site for the development of peripheral resistance and, typically, the site of origin for numerous pathologies. Ultrafine PM--also referred to as nanoparticles, which are defined as ambient and engineered particles with at least one physical dimension less than 100 nm (Oberdorster et al. 2005)--has been suggested to be more toxic than its larger counterparts by virtue of a larger surface area per unit mass. The purpose of this study was fourfold: (1) determine whether particle size affects the severity of postexposure microvascular dysfunction; (2) characterize alterations in microvascular nitric oxide (NO) production after PM exposure; (3) determine whether alterations in microvascular oxidative stress are associated with NO production, arteriolar dysfunction, or both; and (4) determine whether circulating inflammatory mediators, leukocytes, neurologic mechanisms, or a combination of these play a fundamental role in mediating pulmonary PM exposure and peripheral microvascular dysfunction. To achieve these goals, we created an inhalation chamber that generates stable titanium dioxide (TiO2) aerosols at concentrations up to 20 mg/m3. TiO2 is a well-characterized particle devoid of soluble metals. Sprague Dawley and Fischer 344 (F-344) rats were exposed to fine or nano-TiO2 PM (primary count modes of approximately 710 nm and approximately 100 nm in diameter, respectively) at concentrations of 1.5 to 16 mg/m3 for 4 to 12 hours to produce pulmonary loads of 7 to 150 microg in each rat. Twenty-four hours after pulmonary exposure, the following procedures were performed: the spinotrapezius muscle was prepared for in vivo microscopy, blood samples were taken from an arterial line, and various tissues were harvested for histologic and immunohistochemical analyses. Some rats received a bolus dose of cyclophosphamide 3 days prior to PM exposure to deplete circulating neutrophils and bronchoalveolar lavage (BAL) was performed in separate groups of rats exposed to identical TiO2 loads. No significant differences in BAL fluid composition based on PM size or load were found in these rats. Plasma levels of interleukin (IL)-2, IL-18, IL-13, and growth-related oncogene (GRO) (also known as keratinocyte-derived-chemokine [KC]) were altered after PM exposure. In rats exposed to fine TiO2, endothelium-dependent arteriolar dilation was significantly decreased, and this dysfunction was robustly augmented in rats exposed to nano-TiO2. This effect was not related to an altered smooth-muscle responsiveness to NO because arterioles in both groups dilated comparably in response to the NO donor sodium nitroprusside (SNP). Endogenous microvascular NO production was similarly decreased after inhalation of either fine or nano-TiO2 in a dose-dependent manner. Microvascular oxidative stress was significantly increased among both exposure groups. Furthermore, treatment with antioxidants (2,2,6,6-tetramethylpiperdine-N-oxyl [TEMPOL] plus catalase), the myeloperoxidase (MPO) inhibitor 4-aminobenzoic hydrazide (ABAH), or the nicotinamide adenine dinucleotide phosphate oxidase (NADPH oxidase) inhibitor apocynin partially restored NO production and normalized arteriolar function in both groups. Neutrophil depletion restored dilation in PM-exposed rats by as much as 42%. Coincubation of the spinotrapezius muscle with the fast sodium (Na+) channel antagonist tetrodotoxin (TTX) restored arteriolar dilation by as much as 54%, suggesting that sympathetic neural input may be affected by PM exposure. The results of these experiments indicate that (1) the size of inhaled PM dictates the intensity of systemic microvascular dysfunction; (2) this arteriolar dysfuncti

  1. PARTICULATE EMISSIONS AND CONTROL IN FLUIDIZED-BED COMBUSTION: MODELING AND PARAMETRIC PERFORMANCE

    EPA Science Inventory

    The report discusses a model, developed to describe the physical characteristics of the particulates emitted from fluidized-bed combustion (FBC) systems and to evaluate data on FBC particulate control systems. The model, which describes the particulate emissions profile from FBC,...

  2. Variations in the optical properties of terrigenous mineral-rich particulate matter suspended in seawater

    E-print Network

    Stramski, Dariusz

    Variations in the optical properties of terrigenous mineral-rich particulate matter suspended and understanding of the absorption and scattering properties of suspended particulate matter at the level of detail of particulate matter. For example, a à p(l) at blue wavelengths varied from ,0.05 m2 g21 for organic

  3. Bio-derived fuels may ease the regeneration of diesel particulate traps

    Microsoft Academic Search

    E. Coda Zabetta; M. Hupa; S. Niemi

    2006-01-01

    Particulate is the most problematic emission from diesel engines. To comply with environmental regulations, these engines are often equipped with particulate traps, which must be regenerated frequently for the sake of efficiency. The regeneration is commonly achieved by rising the temperature in the trap till the particulate self-ignites. However, this method implies energy losses and thermal shocks in the trap.

  4. Electrically heated particulate filter regeneration methods and systems for hybrid vehicles

    DOEpatents

    Gonze, Eugene V. (Pinckney, MI); Paratore, Jr., Michael J. (Howell, MI)

    2010-10-12

    A control system for controlling regeneration of a particulate filter for a hybrid vehicle is provided. The system generally includes a regeneration module that controls current to the particulate filter to initiate regeneration. An engine control module controls operation of an engine of the hybrid vehicle based on the control of the current to the particulate filter.

  5. Tritium recovery from carbon particulate Until 2009 the JET machine has operated with a

    E-print Network

    Tritium recovery from carbon particulate Background Until 2009 the JET machine has operated vessel. This deposition process traps tritium with the carbon and creates a mobile particulate when in a significant tritium inventory within the particulate and outside of the fuel cycle at JET and ITER. Project

  6. Particulate emissions from commercial shipping: Chemical, physical, and optical properties

    Microsoft Academic Search

    Daniel A. Lack; James J. Corbett; Timothy Onasch; Brian Lerner; Paola Massoli; Patricia K. Quinn; Timothy S. Bates; Derek Coffman; Berko Sierau; Scott Herndon; James Allan; Tahllee Baynard; Edward Lovejoy; A. R. Ravishankara; Eric Williams

    2009-01-01

    provide chemical and physical characteristics including sulfate (SO4 2? ) mass, organic matter (OM) mass, black carbon (BC) mass, particulate matter (PM) mass, number concentrations (condensation nuclei (CN) > 5 nm), and cloud condensation nuclei (CCN). Optical characterization included multiple wavelength visible light absorption and extinction, extinction relative humidity dependence, and single scatter albedo (SSA). The global contribution of shipping

  7. Personal Coarse Particulate Matter Exposures in an Adult Cohort

    EPA Science Inventory

    Volunteers associated with the North Carolina Adult Asthma and Environment Study (NCAAES) participated in an investigation of personal daily exposures to coarse and fine particulate matter size fractions (PM10-2.5, PM2.5). Data from these personal measuremen...

  8. Coupled Particulate and Continuum Model for Nanoparticle Targeted Delivery

    PubMed Central

    Tan, Jifu; Wang, Shunqiang; Yang, Jie; Liu, Yaling

    2013-01-01

    Prediction of nanoparticle (NP) distribution in a vasculature involves transport phenomena at various scales and is crucial for the evaluation of NP delivery efficiency. A combined particulate and continuum model is developed to model NP transport and delivery processes. In the particulate model ligand-receptor binding kinetics is coupled with Brownian dynamics to study NP binding on a microscale. An analytical formula is derived to link molecular level binding parameters to particulate level adhesion and detachment rates. The obtained NP adhesion rates are then coupled with a convection-diffusion-reaction model to study NP transport and delivery at macroscale. The binding results of the continuum model agree well with those from the particulate model. The effects of shear rate, particle size and vascular geometry on NP adhesion are investigated. Attachment rates predicted by the analytical formula also agree reasonably well with the experimental data reported in literature. The developed coupled model that links ligand-receptor binding dynamics to NP adhesion rate along with macroscale transport and delivery processes may serve as a faster evaluation and prediction tool to determine NP distribution in complex vascular networks. PMID:23729869

  9. MEASUREMENTS AND PARAMETERIZATION OF PARTICULATE SULFUR DRY DEPOSITION OVER GRASS

    EPA Science Inventory

    Eddy-correlation measurements of particulate sulfur fluxes at the 1981 and 1982 Dry Deposition Intercomparison Experiments indicate a strong diurnal variation in deposition velocity (downward flux divided by concentration) at a height near 6 m. Values are considerably greater tha...

  10. PARTICULATE CONTROL IN ENERGY PROCESSES: A STATUS REPORT

    EPA Science Inventory

    This paper presents the significant findings of the 22 papers delivered at the Particulate Control in Energy Processes Symposium, held in San Francisco on May 12-14, 1976. Topics of discussion included use of low sulfur coals, electrostatic precipitators for low sulfur coal, bagh...

  11. Chemical characterization of particulate emissions from diesel engines: A review

    Microsoft Academic Search

    M. Matti Maricq

    2007-01-01

    This review examines the chemical properties of particulate matter (PM) in diesel vehicle exhaust at a time when emission regulations, diesel technology development, and particle characterization techniques are all undergoing rapid change. The aim is to explore how changes in each of these areas impact the others. Particle composition is of central interest to the practical issues of health effects,

  12. Can Particulate Pollution Affect Lung Function in Healthy Adults?

    EPA Science Inventory

    Accompanying editorial to paper from Harvard by Rice et al. entitled "Long-Term Exposure to Traffic Emissions and Fine Particulate Matter and Lung Function Decline in the Framingham Heart StudyBy almost any measure the Clean Air Act and its amendments has to be considered a...

  13. 40 CFR 52.1025 - Control strategy: Particulate matter.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Maine § 52.1025 Control strategy: Particulate matter...three million up to but not including ten million Btu per hour Maine 100.3.1(b) 3/29/73 (b) The revision...

  14. 40 CFR 52.1025 - Control strategy: Particulate matter.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Maine § 52.1025 Control strategy: Particulate matter...three million up to but not including ten million Btu per hour Maine 100.3.1(b) 3/29/73 (b) The revision...

  15. 40 CFR 52.1025 - Control strategy: Particulate matter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Maine § 52.1025 Control strategy: Particulate matter...three million up to but not including ten million Btu per hour Maine 100.3.1(b) 3/29/73 (b) The revision...

  16. 40 CFR 52.1025 - Control strategy: Particulate matter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Maine § 52.1025 Control strategy: Particulate matter...three million up to but not including ten million Btu per hour Maine 100.3.1(b) 3/29/73 (b) The revision...

  17. Erosion in conical diffusers in particulate-laden cavitating flow

    Microsoft Academic Search

    J. Madadnia; I. Owen

    1995-01-01

    This paper highlights the serious damage that can occur in diffusing sections of pipework in which a cavitating particulate-laden fluid is flowing. The combined effects of particle erosion and cavitation are shown to remove considerably more material than would be expected from summing the effects of the individual mechanisms. It is demonstrated that, to be sure of avoiding this accelerated

  18. Self-healing of damaged particulate materials through sintering

    Microsoft Academic Search

    S. Luding; A. S. J. Suiker

    2008-01-01

    Particulate materials loaded under uniaxial compression and tension are studied using the Discrete Element Method (DEM). Self-healing of the damaged samples is activated through sintering, a process that effectively increases the contact adhesion (i.e., the tensile strength) between particles. The initial sample is prepared from spherical particles by applying high (isotropic) pressure, where particles in contact deform plastically and adhere

  19. RECEPTOR MODELS RELATING AMBIENT SUSPENDED PARTICULATE MATTER TO SOURCES

    EPA Science Inventory

    The report describes the use of receptor models to determine the source contributions to ambient particulate matter loadings at sampling sites, based on common properties between sources and receptors. (This is in contrast to using source models which start with emission rates an...

  20. ULTRAFINE PARTICULATE MATTER EXPOSURE ATTENUATES MOUSE AORTIC RELAXATIONS

    EPA Science Inventory

    Particulate air pollution (PM) contributes to adverse cardiovascular events by yet unknown mechanisms. We tested the hypothesis that PM exposure altered endothelial regulation of systemic vascular tone. 6-10 week old male ICR mice were exposed to a single dose of 10, 30 or 100 'g...

  1. Airborne particulate soiling of terrestrial photovoltaic modules and cover materials

    Microsoft Academic Search

    A. R. Hoffman; C. R. Maag

    1980-01-01

    Results are presented for the first phase of a photovoltaic-module soiling study that was carried out with NASA participation to investigate the problem of the electrical performance degradation of flat-plate photovoltaic modules exposed at outdoor sites that is due to the accumulation of airborne particulates on sensitive optical surfaces. The results were obtained in both field and laboratory soiling experiments,

  2. Twenty years of experience with particulate silicone in plastic surgery

    Microsoft Academic Search

    Jaime Planas; Carlos del Cacho

    1992-01-01

    The use of particulate silicone in plastic surgery involves the introduction of solid silicone into the body. The silicone is in small pieces in order for it to adapt to the shape of the defect. This way large quantities can be introduced through small incisions. It is also possible to distribute the silicone particles from outside the skin to make

  3. SIMPLEX OPTIMIZATION OF MULTIELEMENT ULTRASONIC EXTRACTION OF ATMOSPHERIC PARTICULATES

    EPA Science Inventory

    A Simplex search was used to locate an optimum for an ultrasonic extraction of trace elements from atmospheric particulates collected on glass fiber high-volume sampler filters. The optimized procedure produced quantitative results for 13 elements with precisions of 10% or less, ...

  4. A novel optical scattering collection system for particulate monitoring applications

    Microsoft Academic Search

    B. E. Bernacki; A. C. Jr. Miller; R. J. Nuspliger

    1996-01-01

    Light collecting systems often require radically different optical surfaces than those commonly found in optical imaging systems. An optical particulate monitor must probe a volume in emission stacks to obtain a good statistical distribution of suspended particles. However, ideal imaging systems map object planes into conjugate image planes and can probe only small volumes. The authors describe the design, fabrication

  5. PREDICTION OF FINE PARTICULATE LEVELS AT UNMONITORED LOCATIONS

    EPA Science Inventory

    In November and December of 1999, air concentrations of ultrafine, fine, and coarse particulate matter were measured at two intensive sites in El Paso, Texas. The intensive sites included collocated measurements of NO2 and volatile organic compounds (VOCs) in the air from both...

  6. Penetration of particulated shaped-charge jet into water

    Microsoft Academic Search

    Eun S. Lee; Kyoung H. Oh; So Y. Song

    1995-01-01

    Flash radiographic and high speed photographic observations have been made on the particulated shaped charge jets penetrating into water. As a foregoing jet particle impacted water and delivered its kinetic energy to water, the water expanded radially to produce a bubble around the penetrating jet particle and a shock wave ahead of the bubble. This kind of penetration process was

  7. 40 CFR 60.402 - Standard for particulate matter.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Standards of Performance for Phosphate Rock Plants § 60.402 Standard for particulate...atmosphere: (1) From any phosphate rock dryer any gases which: (i) Contain...030 kilogram per megagram of phosphate rock feed (0.06 lb/ton), or...

  8. 40 CFR 60.402 - Standard for particulate matter.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Standards of Performance for Phosphate Rock Plants § 60.402 Standard for particulate...atmosphere: (1) From any phosphate rock dryer any gases which: (i) Contain...030 kilogram per megagram of phosphate rock feed (0.06 lb/ton), or...

  9. 40 CFR 60.402 - Standard for particulate matter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Standards of Performance for Phosphate Rock Plants § 60.402 Standard for particulate...atmosphere: (1) From any phosphate rock dryer any gases which: (i) Contain...030 kilogram per megagram of phosphate rock feed (0.06 lb/ton), or...

  10. 40 CFR 60.402 - Standard for particulate matter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Standards of Performance for Phosphate Rock Plants § 60.402 Standard for particulate...atmosphere: (1) From any phosphate rock dryer any gases which: (i) Contain...030 kilogram per megagram of phosphate rock feed (0.06 lb/ton), or...

  11. CONCENTRATED AMBIENT PARTICULATE STUDIES IN HEALTHY AND COMPROMISED RODENTS

    EPA Science Inventory

    CONCENTRATED AMBIENT PARTICULATE STUDIES IN HEALTHY AND COMPROMISED RODENTS. WP Watkinson1, LB Wichers2, JP Nolan1, DW Winsett1, UP Kodavanti1, MCJ Schladweiler1, LC Walsh1, ER Lappi1, D Terrell1, R Slade1, AD Ledbetter1, and DL Costa1. 1USEPA, ORD/NHEERL/ETD/PTB, RTP, NC, US...

  12. Anthropogenic contribution of magnetic particulates in urban roadside dust

    Microsoft Academic Search

    Wonnyon Kim; Seong-Jae Doh; Yongjae Yu

    2009-01-01

    Environmental magnetism parameters have been optimized as qualitative proxy indicators of the distribution of anthropogenic particulates, heavy metals and\\/or organic materials. In the present study, we propose a quantitative magnetic proxy which is suitable for the monitoring of spatial and temporal pollution patterns in urban areas. A total of 1353 roadside dust samples were collected from Seoul, Korea for 13

  13. Molecular Distribution of Particulate Carbohydrates In Marine Waters

    Microsoft Academic Search

    C. Panagiotopoulos; R. Lafont; R. Sempéré

    2002-01-01

    Particulate samples were collected by using floating sediment traps (50-300 m) and in situ pumps (30 and 200 m) collected in the southern Indian Ocean, Mediterranean Sea and Atlantic Ocean. They were studied for monosaccharide composition after acid hydrolysis (HCl 0.09 M, 20 h, 100 °C) by using High Performance Anion Exchange Chromatography followed by Pulsed Amperometric Detection (HPAEC- PAD)

  14. PARTICULATE CONTROL HIGHLIGHTS: PERFORMANCE AND DESIGN MODEL FOR SCRUBBERS

    EPA Science Inventory

    The report gives a capsule summary of the best available design models for wet scrubbers and their application to fine particulate control. Details of the models are reported in the Scrubber Handbook and other EPA publications listed in the bibliography. When EPA initiated its We...

  15. DESIGN, DEVELOPMENT, AND DEMONSTRATION OF A FINE PARTICULATE MEASURING DEVICE

    EPA Science Inventory

    The report describes the design, development, and testing of a fine particulate source monitoring instrument for real-time measurement of mass concentration as a function of aerodynamic particle size. It includes a literature review and selection of the operating principle on whi...

  16. A preliminary particulate matter emission factor from cotton harvesting.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Particulate matter (PM) sampling of cotton harvesting operations at three locations in Texas was conducted during the summer of 2006. PM emissions generated by a two-row (John Deere Model 9910) and six-row (John Deere Model 9996) cotton picker were measured at each sampling location. The PM emission...

  17. Size and chemical characterization of airborne particulate matter in Spokane

    SciTech Connect

    Haller, L.; Claiborn, C.; Westberg, H. [Washington State Univ., Pullman, WA (United States); Koenig, J.; Larson, T. [Univ. of Washington, Seattle, WA (United States)

    1996-12-31

    Recent health effects studies suggest that the present air quality standard for aerosols, which is based upon respirable particles, does not adequately protect public health; Thus the standard is currently under review. In July, 1994, a comprehensive study was initiated in Spokane to study the relationship between various size fractions and chemical components of atmospheric aerosol and health effects. This study is one of the most comprehensive particulate matter studies conducted to date, and is one of a limited number of studies that have been conducted in the and west, where presumably a significant portion of the aerosol will be derived from geological materials. Continuous fine and coarse particulate matter measurements are made at two location (one is in industrial area, and the other in residential area). At the residential site, particulate matter smaller than 1.0 {mu}m, and ultra fine particles are also continuously monitored, and analyzed for a variety of chemical species including elemental components, ionic species, soluble iron, elemental and organic carbon and acidity. Preliminary results indicate that the windblown dust enhances both the fine and coarse fractions of particulate matter in Spokane. Seasonal trends in chemical composition and size characterization will be examined. The relationships between the 24-hour average values and peak hourly values, as well as differences between weekday and weekend levels, will also be discussed.

  18. CRITICAL REVIEW OF OPEN SOURCE PARTICULATE EMISSION MEASUREMENTS: FIELD COMPARISON

    EPA Science Inventory

    The report gives results of a review of sampling and analytical procedures used by various testing firms to quantify particulate emissions from open sources; e.g., roads and storage piles. Seven firms, who account for nearly 100 percent of all open source data in the literature, ...

  19. INVESTIGATING PREFERENTIAL DISSOLUTION OF LEAD FROM SOLDER PARTICULATES

    EPA Science Inventory

    Water samples taken in a building corrosion control study having high lead levels often contained particulate material at the bottom of the acid-preserved sample bottles. canning electron microscope analysis of the particles revealed the presence of tin and absence of lead, indic...

  20. INVESTIGATING THE PREFERENTIAL DISSOLUTION OF LEAD FROM SOLDER PARTICULATES

    EPA Science Inventory

    During a building corrosion control study, bottles containing acid-preserved water samples with high levels of lead often had particulate material on the bottom. Scanning electron microscope analysis of the particles showed the presence of tin and the absence of lead, indicating ...

  1. Lidar Based Particulate Flux Measurements of Agricultural Field

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A three-wavelength portable scanning lidar system was developed to derive information on particulate spatial aerosol distribution over remote distances. The lidar system and retrieval approach has been tested during several field campaigns measuring agricultural emissions from a swine feeding operat...

  2. The Morgantown Energy Technology Center`s particulate cleanup program

    SciTech Connect

    Dennis, R.A.

    1995-12-01

    The development of integrated gasification combined cycle (IGCC) and pressurized fluidized-bed combustion (PFBC) power systems has made it possible to use coal while still protecting the environment. Such power systems significantly reduce the pollutants associated with coal-fired plants built before the 1970s. This superior environmental performance and related high system efficiency is possible, in part, because particulate gas-stream cleanup is conducted at high-temperature and high-pressure process conditions. A main objective of the Particulate Cleanup Program at the Morgantown Energy Technology Center (METC) is to ensure the success of the CCT demonstration projects. METC`s Particulate Cleanup Program supports research, development, and demonstration in three areas: (1) filter-system development, (2) barrier-filter component development, and (3) ash and char characterization. The support is through contracted research, cooperative agreements, Cooperative Research And Development Agreements (CRADAs), and METC`s own in-house research. This paper describes METC`s Particulate Cleanup Program.

  3. SAMPLING AND DATA HANDLING METHODS FOR INHALABLE PARTICULATE SAMPLING

    EPA Science Inventory

    The report reviews the objectives of a research program on sampling and measuring particles in the inhalable particulate (IP) size range in emissions from stationary sources, and describes methods and equipment required. A computer technique was developed to analyze data on parti...

  4. DIII-D Dust Particulate Characterization (June 1998 Vent)

    SciTech Connect

    Carmack, William Jonathan

    1999-01-01

    Dust is a key component of fusion power device accident source term. Understanding the amount of dust expected in fusion power devices and its physical and chemical characteristics is needed to verify assumptions currently used in safety analyses. An important part of this safety research and development work is to characterize dust from existing experimental tokamaks. In this report, we present the collection, data analysis methods used, and the characterization of dust particulate collected from various locations inside the General Atomics DIII-D vacuum vessel following the June 1998 vent. The collected particulate was analyzed at the Idaho National Engineering and Environmental Laboratory (INEEL). Two methods were used to collect particulate with the goal of preserving the particle size distribution and physical characteristics of the particulate. Choice of collection technique is important because the sampling method used can bias the particle size distribution collected. Vacuum collection on substrates and adhesion removal with metallurgical replicating tape were chosen as non-intrusive sampling methods. Seventeen samples were collected including plasma facing surfaces in lower, upper, and horizontal locations, surfaces behind floor tiles, surfaces behind divertor tiles, and surfaces behind ceiling tiles. The results of the analysis are presented.

  5. DIII-D dust particulate characterization (June 1998 Vent)

    SciTech Connect

    Carmack, W.J.

    1999-01-01

    Dust is a key component of fusion power device accident source term. Understanding the amount of dust expected in fusion power devices and its physical and chemical characteristics is needed to verify assumptions currently used in safety analyses. An important part of this safety research and development work is to characterize dust from existing experimental tokamaks. In this report, the authors present the collection, data analysis methods used, and the characterization of dust particulate collected from various locations inside the General Atomics DIII-D vacuum vessel following the June 1998 vent. The collected particulate was analyzed at the Idaho National Engineering and Environmental Laboratory (INEEL). Two methods were used to collect particulate with the goal of preserving the particle size distribution and physical characteristics of the particulate. Choice of collection technique is important because the sampling method used can bias the particle size distribution collected. Vacuum collection on substrates and adhesion removal with metallurgical replicating tape were chosen as non-intrusive sampling methods. Seventeen samples were collected including plasma facing surfaces in lower, upper, and horizontal locations, surfaces behind floor tiles, surfaces behind divert or tiles, and surfaces behind ceiling tiles. The results of the analysis are presented.

  6. Determination of PAHs in particulate air by micellar liquid chromatography

    SciTech Connect

    Kayali, M.N.; Rubio-Barroso, S.; Polo-Diez, L.M. (Complutense Univ. of Madrid (Spain). Dept. of Analytical Chemistry)

    1994-01-01

    An acetonitrile/0.20M SDS mobile phase was used to determine PAHs by HPLC with fluorimetric detection. Because the peak area is greater the method is more sensitive than using an acetonitrile/water mobile phase. The method was applied to determine PAHs in particulate air samples and the results are in good agreement with those found by GC.

  7. 40 CFR 266.105 - Standards to control particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Hazardous Waste Burned in Boilers and Industrial Furnaces § 266.105 Standards to...particulate matter. (a) A boiler or industrial furnace burning hazardous waste...requirements of § 266.109(b) for the low risk waste exemption is exempt from the...

  8. COLLECTION, CHEMICAL FRACTIONATION, AND MUTAGENICITY BIOASSAY OF AMBIENT AIR PARTICULATE

    EPA Science Inventory

    The influence of industrialization and consequent increased concentration of urban particulate matter on the incidence of cancer has long been a concern. The first bioassays used to evaluate complex ambient air samples were whole-animal carcinogenesis bioassays. In these studies,...

  9. Pulmonary phospholipidosis in rats respiring air containing diesel particulates1

    Microsoft Academic Search

    C. D. Eskelson; M. Chvapil; K. A. Strom; J. J. Vostal

    1987-01-01

    Rats chronically exposed to diesel particulates (dp) or given intratracheally a single dose of dp show increased levels of phospholipids in the lungs and in pulmonary lavage fluid. Pulmonary phospholipidosis is accompanied by increase lecithin levels and by increased palmitate content in lecithin of both lungs and pulmonary lavage fluid. A de novo increase of pulmonary and hepatic phospholipid (PL)

  10. AN EVALUATION OF THE PROTEIN MASS OF PARTICULATE MATTER

    EPA Science Inventory

    A comparison of ambient particulate matter mass concentrations with the total protein mass concentration has not been performed previously for North Carolina and was the goal of this study. The analysis of total protein mass was used as an all inclusive indicator of biologically ...

  11. ASSESSMENT OF HUMAN EXPOSURE TO AMBIENT PARTICULATE MATTER.

    EPA Science Inventory

    Recent epidemiological studies have consistently shown that the acute mortality effects of high concentrations of ambient particulate matter (PM), documented in historic air pollution episodes, may also be occurring at the low to moderate concentrations of ambient PM found in mod...

  12. Electrically heated particulate filter diagnostic systems and methods

    DOEpatents

    Gonze, Eugene V [Pinckney, MI

    2009-09-29

    A system that diagnoses regeneration of an electrically heated particulate filter is provided. The system generally includes a grid module that diagnoses a fault of the grid based on at least one of a current signal and a voltage signal. A diagnostic module at least one of sets a fault status and generates a warning signal based on the fault of the grid.

  13. Provisional Assessment of Recent Studies on Particulate Matter (2006)

    EPA Science Inventory

    A review of the national ambient air quality standards (NAAQS) for particulate matter (PM) is currently underway. The Criteria Document was completed in October 2004, and a proposed decision to revise the PM NAAQS was published in January 2006. The final decision is to be signe...

  14. OXIDATIVE STRESS PARTICIPATES IN PARTICULATE MATTER (PM) INDUCED LUNG INJURY

    EPA Science Inventory

    Oxidative stress participates in particulate matter (PM) induced acute lung injury. Elizabeth S. Roberts1, Judy L. Richards2, Kevin L. Dreher2. 1College of Veterinary Medicine, NC State University, Raleigh, NC, 2US Environmental Protection Agency, NHEERL, RTP, NC. Epidemiol...

  15. Rotary device for removing particulates from a gas stream

    NASA Technical Reports Server (NTRS)

    Collins, Jr., Earl R. (Inventor)

    1992-01-01

    A rotary particulate separator for removing particulates from a pressurized gas stream such as that emanating from a reactor vessel is disclosed which precharges the particles in the gas stream, and then utilizes the charge on the particles to induce them from the main flow path through an airblock and into the rotary particulate separator. The rotor of the rotary particulate separator has polarized plates which use a first charge opposite that on the charged particles to attract the particles as they enter the rotation chamber, and then use a second charge of the same polarity as the charge on the charged particles to release the particles into a control gas flow vortex which draws the particles radially inwardly into an exit aperture contained in the center of one of the rotor segments and out from the device. Pressure letdown devices are used to drop the pressure of both the control gas flow exiting the separator with the particles and the cleaned gas stream.

  16. CAPSULE REPORT: BAHCO FLUE GAS DESULFURIZATION AND PARTICULATE REMOVAL SYSTEM

    EPA Science Inventory

    This capsule report describes a Research-Cottrell/Bahco scrubber module for sulfur dioxide and particulate emission control located at the central heat plant of Rickenbacker Air Force Base. he report also describes flue gas desulfurization technology using any fuel, including hig...

  17. Chemical characterization of environmental and industrial particulate samples

    E-print Network

    Chemical characterization of environmental and industrial particulate samples H. M. Ortner*a, P. Hoffmanna, F. J. Stadermannb, S. Weinbrucha and M. Wentzelc a Department of Chemical Analytics, Materials of scientific and industrial fields, as outlined below. In atmospheric sciences, the characterization

  18. Introduction Analysis of elemental concentrations in aquatic particulate

    E-print Network

    Sterner, Robert W.

    96 Introduction Analysis of elemental concentrations in aquatic particulate matter (seston) has been an important component of many lim- nological and oceanographic studies. Seston carbon (C), nitro are similar to the traditional methods. One of the most promising methods for seston elemental analysis

  19. EXPOSURE ASSESSMENT OF PARTICULATE MATTER FOR SUSCEPTIBLE POPULATIONS IN SEATTLE

    EPA Science Inventory

    In this article we present results from a 2-year comprehensive exposure assessment study that examined the particulate matter (PM) exposures and health effects in 108 individuals with and without chronic obstructive pulmonary disease (COPD), coronary heart disease (CHD), and as...

  20. 40 CFR 60.152 - Standard for particulate matter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Sewage Treatment Plants § 60.152 Standard for particulate matter...conducted by § 60.8 is completed, no owner or operator of any sewage sludge incinerator subject to the provisions of this...

  1. Rain Scavenging of Radioactive Particulate Matter from the Atmosphere

    Microsoft Academic Search

    S. M. Greenfield

    1957-01-01

    On the basis of Langmuir's theory of collection efficiencies, a model is derived to explain the removal of radioactive particulate matter from the atmosphere by rain. In this connection, Langmuir's collection efficiencies are modified to take into account the density of the solid particles, and are adjusted to express the fraction removed from a vertical cylinder of constant diameter. It

  2. TECHNIQUE FOR IN SITU CALIBRATION OF PARTICULATE MASS MONITORS

    EPA Science Inventory

    Two types of aerosol generators, the Riker Laboratories metered spray can and the Mistogen EN145 ultrasonic nebulizer, were evaluated by laboratory measurements for application to the in situ calibration of particulate mass monitors for stationary sources. The metered spray can d...

  3. HIGH-TEMPERATURE AND HIGH-PRESSURE PARTICULATE CONTROL REQUIREMENTS

    EPA Science Inventory

    The report reviews and evaluates high-temperature and high-pressure particulate cleanup requirements of existing and proposed energy processes. The study's aims are to define specific high-temperature and high-pressure particle removal problems, to indicate potential solutions, a...

  4. Damping and Stiffness of Particulate SiCInSn Composite

    E-print Network

    Swan Jr., Colby Corson

    of viscoelastic properties, even creep, of particulate reinforced MMCs, is not common [5]. The effect of material are not common. In structural metals such as brass, steel, and aluminum, viscoelastic effects are usually small temperature [4]. Metal matrix composites (MMCs) offer attractive physical and mechanical properties

  5. The Role of Particulate Matter in Exacerbation of Atopic Asthma

    Microsoft Academic Search

    Stephen H. Gavett; Hillel S. Koren

    2001-01-01

    Increasing evidence shows that elevated levels of particulate matter (PM) can exacerbate existing asthma, while evidence that PM can promote the induction of asthma is limited. PM in ambient air has been associated with increased emergency room visits and medication use by asthmatics. Controlled human exposure studies of acid aerosols suggest increased responses among adolescent asthmatics. Increased ambient and indoor

  6. Particulate matter neurotoxicity in culture is size-dependent

    EPA Science Inventory

    Exposure to particulate matter (PM) air pollution produces inflammatory damage to the cardiopulmonary system. This toxicity appears to be inversely related to the size of the PM particles, with the ultrafine particle being more inflammatory than larger sizes. Exposure to PM has m...

  7. Physique des particules Mention : Sciences de la matire

    E-print Network

    Sart, Remi

    Physique des particules Mention : Sciences de la matière Nature de la formation : Diplôme national : Formation initiale Formation continue Lieu de formation : Campus des Cézeaux (Aubière) #12;2 Physique des 200 premières universités mondiales en physique dans le classement Shanghaï 2013". La mention Sciences

  8. CHARACTERIZATION OF COTTON GIN PARTICULATE MATTER EMISSIONS – FIRST YEAR

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Due to EPA’s implementation of more stringent standards for particulate matter with an effective diameter less than 2.5 microns, the cotton ginners’ associations across the cotton belt, including the National, Texas, Southern, Southeastern, and California associations, agreed that there is an urgent...

  9. Particulate matter adjacent to cattle deep-bedded monoslope facilities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Purpose: Confined cattle facilities are an increasingly common housing system in the Northern Great Plains region. Many of these facilities add organic bedding material to the pens once or twice per week. Particulate matter concentrations and emissions from these facilities have not been evaluate...

  10. Integrated Science Assessment for Particulate Matter (First External Review Draft)

    EPA Science Inventory

    EPA has announced that the First External Review Draft of the Integrated Science Assessment (ISA) for Particulate Matter and related Annexes have been made available for independent peer review and public review. This draft ISA document represents a concise synthesis and e...

  11. Integrated Science Assessment for Particulate Matter (Second External Review Draft)

    EPA Science Inventory

    EPA has announced that the Second External Review Draft of the Integrated Science Assessment (ISA) for Particulate Matter (PM) have been made available for independent peer review and public review. The ISA reflects the latest scientific knowledge useful in indicating the kind...

  12. BAYESIAN HIERARCHICAL MODELING OF PERSONAL EXPOSURE TO PARTICULATE MATTER

    EPA Science Inventory

    In the US EPA's 1998 Baltimore Epidemiology-Exposure Panel Study, a group of 21 residents of a single building retirement community wore personal monitors recording personal fine particulate air pollution concentrations (PM2.5) for 27 days, while other monitors recorde...

  13. EVALUATION OF FOUR NOVEL FINE PARTICULATE COLLECTION DEVICES

    EPA Science Inventory

    The report gives results of an experimental performance evaluation of four novel fine particulate control devices: the Johns-Manville Cleanable High-Efficiency Air Filtration (CHEAF) System, the APS Electrostatic Scrubber, the APS Electrotube, and the TRW Charged Droplet Scrubber...

  14. RESPIRATORY DISEASE IN CHILDREN EXPOSED TO SULFUR OXIDES AND PARTICULATES

    EPA Science Inventory

    Acute lower respiratory disease was surveyed by questionnaire among parents of 10,000 children aged 1 to 12 years in two Southeastern communities representing intermediate and high exposures to particulates and low sulfur dioxide levels. Morbidity reporting patterns with respect ...

  15. DEVELOPMENT OF A LARGE SAMPLE COLLECTOR OF RESPIRABLE PARTICULATE MATTER

    EPA Science Inventory

    A prototype sampler designed to collect particulate matter from air in sized fractions has been designed and tested. The sampler excludes particles above 20 micrometers in diameter and collects fractions centered at 3.5 micrometers and 1.7 micrometers on impaction plates and smal...

  16. Characterization of cotton gin particulate matter emissions - project plan

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2006, EPA implemented a more stringent standard for particulate matter with an effective diameter less than 2.5 microns (PM2.5). The implementation time line for this standard will vary by state/district regulatory agency. For example, the San Joaquin Valley Air Pollution Control District has pro...

  17. The geocentric particulate distribution: Cometary, asteroidal, or space debris?

    NASA Astrophysics Data System (ADS)

    McDonnell, J. A. M.; Ratcliff, P. R.

    1992-12-01

    Definition of the Low Earth Orbit (LEO) particulate environment has been refined considerably with the analysis of data from NASA's Long Duration Exposure Facility (LDEF). Measurements of the impact rates from particulates ranging from sub-micron to millimetres in dimension and, especially, information on their directionality has permitted new scrunity of the sources of the particulates. Modelling of the dynamics of both bound (Earth orbital) and unbound (hyperbolic interplanetary) particulates intercepting LDEF's faces leads to the conclusion that the source is dominantly interplanetary for particle dimensions of greater than some 5 microns diameter; however the anisotropy below this dimension demands lower velocities and is compatible with an orbital component. Characteristics of the LDEF interplanetary component are compatible with familiar meteoroid sources and deep space measurements. Understanding of the orbital component which exceeds the interplanetary flux by a factor of 4 is less clear; although the very small particulates in orbit have been associated with space debris (Lawrance and Brownlee, 1986) this data conflicts with other measurements (McDonnell, Carey and Dixon, 1984) at the same epoch. By analysis of trajectories approaching the Earth and its atmosphere, we have shown that a significant contribution could be captured by aerocapture, i.e., atmospheric drag, from either asteroidal or cometary sources; such enhancement is unlikely however to provide the temporal and spatial fluctuations observed by the LDEF Interplanetary Dust Experiment (Mullholland et al. 1992). A further new mechanism is also examined, that of aerofragmentation capture, where an atmospheric grazing trajectory, which would not normally lead to capture, leads to fragmentation by thermal or mechanical shock; the microparticulates thus created can be injected in large numbers, but only into short-lifetime orbits. The concentration in one particular orbit plane, could explain the temporal fluctuations seen on LDEF; space debris could also explain the phenomenon.

  18. Particulate problem solutions for rod pumped producing wells

    SciTech Connect

    Williams, S.J.

    1995-12-31

    Sand and other fluid entrained particulates can cause substantial operational problems for rod pumped producing wells. These problems take the form of down-hole pump wear, plunger sticking, and/or catastrophic breakage of pump components. A six year study of 600+ pump investigations shows that problems with particulates account for a substantial number of the total barrel and plunger failures. Many of these failures could have been avoided through the proper application of API and special pump designs as well as certain choices of pump variables. These pump variables and designs will be addressed along with operating parameters. How hard is sand? How large is it? Should plunger and barrel choices take these variables into account? Also, metal plungers must {open_quotes}slip{close_quotes} fluid for proper lubrication. Too much slippage leads to pump inefficiencies. However, down-hole pump efficiencies based on slippage need to be balanced against pump longevity due to proper selection for particulate production. Some time-proven rules of thumb can be applied to make these choices, and an included chart will make plunger slippage calculations simple and straightforward. Scale which sticks to pump surfaces dictates the choice of a different style down-hole pump. A straight-forward modification of an RH style API pump has proved successful in these conditions. Fluid and particulate production with and without attendant gas production requires a different approach to down-hole pump selection. Several successful older pump designs as well as some recently proven new designs will be described. A test program has been completed and actual applications have shown that an API Tubing Pump derivative can pump large volumes of particulate laden fluid without characteristic sticking of the plunger.

  19. Population Density, Particulate Emission Characterization, and Impact on the Particulate Inventory of Smoking Vehicles in the South Coast Air Quality Management District

    Microsoft Academic Search

    Thomas D. Durbin; Matthew R. Smith; Joseph M. Norbeck; Timothy J. Truex

    1999-01-01

    The impact of high-particulate-emission vehicles on the total light-duty vehicle particulate emission inventory in the South Coast Air Quality Management District (SCAQMD) has been estimated by an analysis of the SCAQMD's CUT-SMOG database, a field survey of smoking vehicles, and particulate emissions testing of representative smoking vehicles. The field study, carried out at 61 sites throughout the SCAQMD, showed that

  20. The Adjuvant Effect of Ambient Particulate Matter Is Closely Reflected by the Particulate Oxidant Potential

    PubMed Central

    Li, Ning; Wang, Meiying; Bramble, Lori A.; Schmitz, Debra A.; Schauer, James J.; Sioutas, Constantinos; Harkema, Jack R.; Nel, Andre E.

    2009-01-01

    Background It has been demonstrated that ambient particulate matter (PM) can act as an adjuvant for allergic sensitization. Redox-active organic chemicals on the particle surface play an important role in PM adverse health effects and may determine the adjuvant effect of different particle types according to their potential to perturb redox equilibrium in the immune system. Objectives We determined whether the adjuvant effect of ambient fine particles versus ultrafine particles (UFPs) is correlated to their prooxidant potential. Methods We have established an intranasal sensitization model that uses ambient PM as a potential adjuvant for sensitization to ovalbumin (OVA), which enhances the capacity for secondary OVA challenge to induce allergic airway inflammation. Results UFPs with a greater polycyclic aromatic hydrocarbon (PAH) content and higher oxidant potential enhanced OVA sensitization more readily than did fine particles. This manifests as enhanced allergic inflammation upon secondary OVA challenge, leading to eosinophilic inflammation and mucoid hyperplasia starting at the nasal turbinates all the way down to the small pulmonary airways. The thiol antioxidant N-acetyl cysteine was able to suppress some of these sensitization events. Conclusions The adjuvant effects of ambient UFP is determined by their oxidant potential, which likely plays a role in changing the redox equilibrium in the mucosal immune system. PMID:19654922

  1. Particulate matter < 10 ?m (PM 10) and total suspended particulates (TSP) in urban, rural and alpine air in Switzerland

    Microsoft Academic Search

    Ch. Monn; O. Braendli; G. Schaeppi; Ch. Schindler; U. Ackermann-Liebrich; Ph. Leuenberger

    1995-01-01

    Ambient concentrations of particulate matter of less than 10 ?m aerodynamic diameter were measured in Switzerland for a 1 yr period in 1993 at a dozen urban, rural and alpine sites. PM10 concentrations ranged between 10 ?g m?3 (alpine) and 33 ?g m?3 (urban). Highest concentrations were found at Lugano, in the south of the Alps, and in urban sites

  2. HUMAL ALVEOLAR MACROPHAGE RESPONSES TO AIR POLLUTION PARTICULATES ARE ASSOCIATED WITH INSOLUBLE OCMPONENTS OF COARSE MATERIAL, INCLUDING PARTICULATE ENDOTOXIN

    EPA Science Inventory

    Inhalation of particulate matter in the ambient air has been shown to cause pulmonary morbidity and exacerbate asthma. Alveolar macrophage (AM) are essential for effective removal of inhaled particles and microbes in the lower airways. While some particles minimally effect AM...

  3. Theoretical study of the impact of particulate matter gravitational settling on ambient coarse particulate matter monitoring for agricultural emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The particle size distributions (PSD) of particulate matter (PM) in the downwind plume from simulated sources were analyzed to determine the impact of PM settling on PM monitoring. The PSD of PM in a plume varies as a function of gravitational settling.Gravitational settling has a greater impact on ...

  4. Removal of Sulfur from Natural Gas to Reduce Particulate Matter Emission from a Turbine Engine

    NASA Astrophysics Data System (ADS)

    Spang, Brent Loren

    The present work investigates the effect of natural gas fuel sulfur on particulate emissions from stationary gas turbine engines used for electricity generation. Fuel sulfur from standard line gas was scrubbed using a system of fluidized reactor beds containing a specially designed activated carbon purpose built for sulfur absorption. A sulfur injection system using sonic orifices was designed and constructed to inject methyl mercaptan into the scrubbed gas stream at varying concentrations. Using these systems, particulate emissions created by various fuel sulfur levels between 0 and 8.3 ppmv were investigated. Particulate samples were collected from a Capstone C65 microturbine generator system using a Horiba MDLT-1302TA micro dilution tunnel and analyzed using a Horiba MEXA-1370PM particulate analyzer. In addition, ambient air samples were collected to determine incoming particulate levels in the combustion air. The Capstone C65 engine air filter was also tested for particulate removal efficiency by sampling downstream of the filter. To further differentiate the particulate entering the engine in the combustion air from particulate being emitted from the exhaust stack, two high efficiency HEPA filters were installed to eliminate a large portion of incoming particulate. Variable fuel sulfur testing showed that there was a strong correlation between total particulate emission factor and fuel sulfur concentration. Using eleven variable sulfur tests, it was determined that an increase of 1 ppmv fuel sulfur will produce an increase of approximately 3.2 microg/m3 total particulate. Also, the correlation also predicted that, for this particular engine, the total particulate emission factor for zero fuel sulfur was approximately 19.1 microg/m3. With the EC and OC data removed, the correlation became 3.1 microg/m3 of sulfur particulate produced for each ppmv of fuel sulfur. The correlation also predicted that with no fuel sulfur present, 6.6 microg/m3 of particulate will be produced by sulfur passing through the engine air filter.

  5. Design characteristics for facilities which process hazardous particulate

    SciTech Connect

    Abeln, S.P.; Creek, K.; Salisbury, S.

    1998-12-01

    Los Alamos National Laboratory is establishing a research and processing capability for beryllium. The unique properties of beryllium, including light weight, rigidity, thermal conductivity, heat capacity, and nuclear properties make it critical to a number of US defense and aerospace programs. Concomitant with the unique engineering properties are the health hazards associated with processing beryllium in a particulate form and the potential for worker inhalation of aerosolized beryllium. Beryllium has the lowest airborne standard for worker protection compared to all other nonradioactive metals by more than an order of magnitude. This paper describes the design characteristics of the new beryllium facility at Los Alamos as they relate to protection of the workforce. Design characteristics to be reviewed include; facility layout, support systems to minimize aerosol exposure and spread, and detailed review of the ventilation system design for general room air cleanliness and extraction of particulate at the source.

  6. Simplex optimization of multielement ultrasonic extraction of atmospheric particulates

    SciTech Connect

    Harper, S.L.; Walling, J.F.; Holland, D.M.; Pranger, L.J.

    1983-08-01

    A simplex search was used to locate an optimum for an ultrasonic extraction of trace elements from atmospheric particulates collected on glass-fiber high-volume sampler filters. The optimized procedure produced quantitative results for 13 elements with precisions of 10% or less, and accuracies of 95% or better, while providing the analyst with a more rapid, inexpensive, and less hazardous method than traditional boiling-acid extractions. The procecure has become an Environmental Protection Agency (EPA) designated equivalent method to EPA's lead reference procedure. Results are provided for split sample comparisons on real particulate samples, as well as for synthetic spikes and National Bureau of Standard's Standard Reference Material No. 1648 analyzed by inductively coupled argon plasma optical emission spectrometry, neutron activation analysis, and/or atomic absorption spectrophotometry using other extraction methods. 3 tables.

  7. Oxygenated polycyclic aromatic hydrocarbons in urban air particulate matter

    NASA Astrophysics Data System (ADS)

    María del Rosario Sienra, M.

    Atmospheric concentrations of oxygenated polycyclic aromatic hydrocarbons (Oxy-PAHs) in Santiago de Chile city were evaluated to study particulate Oxy-PAHs profiles during cold and spring weather periods. Samples of urban particulate matter PM10 were collected during July and September-October, using a high volume air sampler provided with glass fiber filters. Samples were analyzed by gas chromatography-mass spectrometry (GC-MS). Ketones, quinones, aldehydes and carboxaldehydes were characterized and quantified. Among 12 oxy-PAHs found in the air samples, 1-pyrenecarboxaldehyde was found the greatest amount at the two sampling seasons (winter and spring) and at the two sampling sites (4.66±4.21 ng m -3 at Providencia and 2.66±2.33 ng m -3 at Las Condes, during winter). Concentration of these carcinogenic compounds is higher than other cities indicating an exposure of the inhabitants of Santiago to high amount of carcinogenic-mutagenic compounds air pollutants.

  8. Fluidizable particulate materials and methods of making same

    DOEpatents

    Gupta, Raghubir P. (Durham, NC)

    1999-01-01

    The invention provides fluidizable, substantially spherical particulate material of improved attrition resistance having an average particle size from about 100 to about 400 microns useful as sorbents, catalysts, catalytic supports, specialty ceramics or the like. The particles are prepared by spray drying a slurry comprising inorganic starting materials and an organic binder. Exemplary inorganic starting materials include mixtures of zinc oxide with titanium dioxide, or with iron oxide, alumina or the like. Exemplary organic binders include polyvinyl alcohol, hydroxypropylemethyl cellulose, polyvinyl acetate and the like. The spray dried particles are heat treated at a first temperature wherein organic binder material is removed to thereby provide a porous structure to the particles, and thereafter the particles are calcined at a higher temperature to cause reaction of the inorganic starting materials and to thereby form the final inorganic particulate material.

  9. Perspectives on Localized Corrosion in Thin Layers of Particulate

    SciTech Connect

    Payer, Joe H. [Materials Science and Engineering, Case Western Reserve University, 10900 Euclid Ave., 404 White Bldg., Cleveland, OH, 44106 (United States); Kelly, Robert G. [Materials Science and Engineering, University of Virginia, 116 Engineer's Way, Materials Science Building 323, PO Box 400745, Charlottesville, VA, 22904-4745 (United States)

    2007-07-01

    The requirements for the initiation and propagation of localized corrosion are reviewed, and the stability criteria for sustained localized corrosion are discussed. A conceptual framework is applied to a specific scenario of a hot metal surface covered by a thin layer of particulate containing dissolvable salts in the presence of air of limited humidity. A number of processes are demonstrated to affect the crevice corrosion propagation, stifling and arrest. Contributions of the particulate layer properties, the anode, cathode and coupled processes are identified, showing that any of these can control localized corrosion propagation. Whether stifling or arrest occur will depend upon the material and environmental conditions for a given case. The findings add to the technical basis for the analysis of localized corrosion by a decision tree methodology. (authors)

  10. Fluidizable particulate materials and methods of making same

    SciTech Connect

    Gupta, R.P.

    1999-10-26

    The invention provides fluidizable, substantially spherical particulate material of improved attrition resistance having an average particle size from about 100 to about 400 microns useful as sorbents, catalysts, catalytic supports, specialty ceramics or the like. The particles are prepared by spray drying a slurry comprising inorganic starting materials and an organic binder. Exemplary inorganic starting materials include mixtures of zinc oxide with titanium dioxide, or with iron oxide, alumina or the like. Exemplary organic binders include polyvinyl alcohol, hydroxypropylemethyl cellulose, polyvinyl acetate and the like. The spray dried particles are heat treated at a first temperature wherein organic binder material is removed to thereby provide a porous structure to the particles, and thereafter the particles are calcined at a higher temperature to cause reaction of the inorganic starting materials and to thereby form the final inorganic particulate material.

  11. Particulate Contamination Within Fusion Devices and Complex (Dusty) Plasmas

    E-print Network

    Creel, J; Kong, J; Hyde, Truell W

    2007-01-01

    Over the past decade, dust particulate contamination has increasingly become an area of concern within the fusion research community. In a burning plasma machine design like the International Thermonuclear Experimental Reactor (ITER), dust contamination presents problems for diagnostic integration and may contribute to tritium safety issues. Additionally due to ITER design, such dust contamination problems are projected to become of even greater concern due to dust/wall interactions and possible instabilities created within the plasma by such particulates. Since the dynamics of such dust can in general be explained employing a combination of the ion drag, Coulomb force, and ion pre-sheath drifts, recent research in complex (dusty) plasma physics often offers unique insights for this research area. This paper will discuss the possibility of how experimental observations of the dust and plasma parameters within a GEC rf Reference Cell might be employed to diagnose conditions within fusion reactors, hopefully pr...

  12. New developments in high-efficiency particulate air filtration

    SciTech Connect

    Smith, T.W. (MAC Equipment, Inc., Sabetha, KS (United States))

    1993-12-01

    High-efficiency particulate air filters (HEPA) are unsurpassed for removing particulates from gas. In the past, their disadvantages and high operating costs discouraged their use for most industrial process applications. But recent improvements broaden the potential applications for this type of filter. In the past, most industries could not tolerate the disadvantages and high operation expense of a conventional static HEPA filter. Recent advances make this option much more practical. Many more industries can now take advantage of the HEPA filter's superior performance, and can enjoy the advantages of returning filtered air to the workplace to save energy costs or avoid an EPA permit, and collect harmful or valuable materials rather than emitting them into the environment. Industry should take a hard look at the automatic-cleaning HEPA filter.

  13. Statistical analysis of the particulation of shaped charge jets

    SciTech Connect

    Minich, R W, Baker, E L; Schwartz, A J

    1999-08-12

    A statistical analysis of shaped charge jet break-up was carried out in order to investigate the role of nonlinear instabilities leading to the particulation of the jet. Statistical methods generally used for studying fluctuations in nonlinear dynamical systems are applied to experimentally measured velocities of the individual particles. In particular we present results suggesting the deviation of non-Gaussian behavior for interparticle velocity correlations, characteristic of nonlinear dynamical systems. Results are presented for two silver shaped charge jets that differ primarily in their material processing. We provide evidence that the particulation of a jet is not random, but has its origin in a deterministic dynamical process involving the nonlinear coupling of two oscillators analogous to the underling dynamics observed in Rayleigh-Benard convection and modeled in the return map of Curry and Yorke.

  14. Effects of travel mode on exposures to particulate air pollution

    Microsoft Academic Search

    David J. Briggs; Kees de Hoogh; Chloe Morris; John Gulliver

    2008-01-01

    Monitoring was carried out of particulate concentrations whilst simultaneously walking and driving 48 routes in London, UK. Monitoring was undertaken during May and June 2005. Route lengths ranged from 601 to 1351 m, and most routes were travelled in both directions. Individual journey times ranged from 1.5 to 15 min by car (average 3.7 min) and 7.3 to 30 min (average 12.8 min) whilst walking;

  15. Diesel Particulate Matter (DPM) in Workplaces in Germany

    Microsoft Academic Search

    Dirk Dahmann; Hans-Dieter Bauer

    1997-01-01

    Diesel particulate matter (DPM) is regarded as carcinogenic in Germany, with threshold limit values for underground noncoal mining of 0.6 mg\\/m and for surface workplaces of 0.2 mg\\/m. The current German practice for workplace surveillance is described, and sampling and measurement procedures are discussed. Currently, diesel soot is collected on quartz fiber filters using the respirable dust fraction and oxidized

  16. Mitigating molecular and particulate contamination via surface energy

    Microsoft Academic Search

    Mark S. Crowder; Christina Haley

    2008-01-01

    Amorphous fluorocarbon (a-C:F) thin films have been developed that protect surfaces from molecular and particulate contamination. The surface energies of the thin films are low and primarily dispersive in origin with values of energies measured to be as low as 18 mJ\\/m2 (17.5 dispersive, 0.5 polar). The films are transparent to visible light and have a refractive index of ~1.4.

  17. Determining true particulate organic carbon: bottles, pumps and methodologies

    Microsoft Academic Search

    Wilford D. Gardner; Mary Jo Richardson; Craig A. Carlson; Dennis Hansell; Alexey V. Mishonov

    2003-01-01

    The primary means of determining particulate organic carbon (POC) concentrations in aquatic environments is by filtering from water bottles or by in situ filtration with pumps and analyzing the filters. The concentrations measured by these two methods, however, can differ by a factor of 1.2–5 in temperate waters, and by factors as large as 200 in cold, high-latitude waters. Here

  18. Advanced hybrid particulate collector and method of operation

    DOEpatents

    Miller, Stanley J. (Grand Forks, ND)

    2003-04-08

    A device and method for controlling particulate air pollutants of the present invention combines filtration and electrostatic collection devices. The invention includes a chamber housing a plurality of rows of filter elements. Between the rows of filter elements are rows of high voltage discharge electrodes. Between the rows of discharge electrodes and the rows of filter elements are grounded perforated plates for creating electrostatic precipitation zones.

  19. Comparative studies on particulate acid phosphatases in sea urchin eggs.

    PubMed

    Yokota, Y; Nakano, E

    1982-01-01

    1. Particulate acid phosphatases were partially purified and characterized in the eggs of six species of sea urchins and one species of sand dollar, Hemicentrotus pulcherrimus, Anthocidaris crassispina, Pseudocentrotus depressus, Strongylocentrotus purpuratus, S. francicanus, S. droebachiensis and Dendraster excentricus. 2. The enzymes of 7 species were strongly inhibited by NaF, tartrate, p-chloromercuribenzoate and HgCl2. 3. Substrate specificity of the enzymes of all species was broad. PMID:7083814

  20. Shear-induced structuring of particulate whey protein gels

    Microsoft Academic Search

    P Walkenström; E Windhab; A.-M Hermansson

    1998-01-01

    The effects of steady shear on particulate whey protein isolate (WPI) gels, at pH 5.4, have been investigated by light microscopy (LM) and dynamic oscillatory measurements. The steady shear was performed on suspensions at constant rates between 0.5 and 126\\/s. The gel point under static conditions (Tg) was around 78°C and the shearing was performed during heating from 20 to

  1. Echo sounding on suspended particulate matter in the elbe estuary

    Microsoft Academic Search

    Jobst Hülsemann; Hendrik Eden; Klaus Ricklefs

    1995-01-01

    Summary  Assessment of suspended particulate matter (SPM) in an estuary, and its transport by tidal currents, is a difficult task in\\u000a spite of the existence of verifiable current models. The first encouraging results from echo soundings are presented.\\u000a \\u000a On station (a moored platform), sonic pulses are simultaneously transmitted through the water column at several frequencies.\\u000a A receiver quantitatively records all energy

  2. Gaseous and Particulate Iodine in the Marine Atmosphere

    Microsoft Academic Search

    Jarvis L. Moyers; Robert A. Duce

    1972-01-01

    Sixty gaseous iodine samples collected from a 20-meter tower on the windward shore of Oahu, Hawaii, during the summer of 1969 showed that the concentration of gaseous iodine ranged from 5 to 20 ng\\/m a. Particulate samples collected simultaneously with the gaseous samples showed that the atmospheric concentrations of gaseous iodine in marine air are 2-4 times the concentration of

  3. Direct-energy-regenerated particulate trap technology. Final report

    Microsoft Academic Search

    D. P. Stinton; M. A. Janney; T. M. Yonushonis; A. C. McDonald; P. D. Wiczynski; W. C. Haberkamp

    1996-01-01

    The objective of this CRADA between Lockheed Martin and Cummins Engine Company was to develop fiber-reinforced silicon carbide (SiC) composite materials for use as diesel engine particulate traps. Chemical vapor deposition techniques were used to partially densify and rigidize a thin fibrous substrate and produce the porous SiC- based filter. Microwave energy was used to directly couple to the deposited

  4. Personal exposure to particulate air pollution in transport microenvironments

    Microsoft Academic Search

    J. Gulliver; D. J. Briggs

    2004-01-01

    Personal measurements of exposure to particulate air pollution (PM10, PM2.5, PM1) were simultaneously made during walking and in-car journeys on two suburban routes in Northampton, UK, during the winter of 1999\\/2000. Comparisons were made between concentrations found in each transport mode by particle fraction, between different particle fractions by transport mode, and between transport microenvironments and a fixed-site monitor located

  5. A PRELIMINARY PARTICULATE MATTER EMISSION FACTOR FROM COTTON HARVESTING

    Microsoft Academic Search

    J. D. Wanjura; S. C. Capareda; W. B. Faulkner

    Particulate matter (PM) sampling of cotton harvesting operations at three locations in Texas was conducted during the summer of 2006. PM emissions generated by a two-row (John Deere model 9910) and six-row (John Deere model 9996) cotton picker were measured at each sampling location. The PM emissions from the two-row and six- row machines were measured using a protocol employing

  6. Suspended particulate matter dynamics in a particle framework

    Microsoft Academic Search

    Ulf Gräwe; Jörg-Olaf Wolff

    2010-01-01

    Suspended particulate matter (SPM) dynamics in ocean models are usually treated with an advection–diffusion equation for one\\u000a or more sediment size classes coupled to the hydrodynamical part of the model. Numerical solution of these additional partial\\u000a differential equations unavoidably introduces numerical diffusion, i.e. in the case of sharp gradients the possible occurrence\\u000a of artificial oscillations and non-positivity. A Lagrangian particle-tracking

  7. Coronagraph particulate measurements. Skylab flight experiment T025

    NASA Technical Reports Server (NTRS)

    Greenberg, J. M.; Schuerman, D. W.; Giovane, F.; Wang, R. T.; Hardy, D. C.

    1975-01-01

    Major results of the Skylab T025 Coronagraph experiment designed to monitor the particulate contamination about the spacecraft and to study the earth's atmospheric aerosol distribution are presented. A model for comet outbursts based on the properties of amorphous ice and ground based narrow-band and white light photography of comet Kohoutek ten days to perihelion are included. The effect of atmospheric refraction on the analysis of the T025 atmospheric data was also investigated.

  8. On the Dynamics of Charged Electromagnetic Particulate Jets

    Microsoft Academic Search

    T. I. Zohdi

    2010-01-01

    This work addresses the modeling and simulation of charged particulate jets in the presence of electromagnetic fields. The\\u000a presentation is broken into two main parts: (1) the dynamics of charged streams of particles and their interaction with electromagnetic\\u000a fields and (2) the coupled thermal fields that arise within the jet. An overall model is built by assembling submodels of\\u000a the

  9. MERCURY CONTROL WITH THE ADVANCED HYBRID PARTICULATE COLLECTOR

    SciTech Connect

    Ye Zhuang; Stanley J. Miller; Grant E. Dunham; Michelle R. Olderbak

    2002-02-01

    Since 1995, DOE has supported development of a new concept in particulate control, called the advanced hybrid particulate collector (AHPC). The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, 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 re-collection of dust in conventional baghouses. The AHPC appears to have unique advantages for mercury control over baghouses or ESPs as an excellent gas-solid contactor. The objective of the three-task project is to demonstrate 90% total mercury control in the AHPC at a lower cost than current mercury control estimates. The approach includes bench-scale batch testing that ties the new work to previous results and links results with larger-scale pilot testing with real flue gas on a coal-fired combustion system, pilot-scale testing on a coal-fired combustion system with both a pulse-jet baghouse and an AHPC to prove or disprove the research hypotheses, and field demonstration pilot-scale testing at a utility power plant to prove scaleup and demonstrate longer-term mercury control. This project, if successful, will demonstrate at the pilot-scale level a technology that would provide a cost-effective technique to accomplish control of mercury emissions and, at the same time, greatly enhance fine particulate collection efficiency. The technology can be used to retrofit systems currently employing inefficient ESP technology as well as for new construction, thereby providing a solution to a large segment of the U.S. utility industry as well as other industries requiring mercury control.

  10. Study of corrosion stability in metal particulate media

    Microsoft Academic Search

    Y. Yamamoto; K. Sumiya; A. Miyake; M. Kishimoto; T. Taniguchi

    1990-01-01

    Metal particulate tape was prepared using stabilized metal particles, and the corrosion stability of the tape was examined under various environmental atmospheres. The decrease of magnetization after exposure to 60°C\\/90% RH (relative humidity) for four weeks was bout 7%. When the tape was stored in a low concentration of pollutants of Cl 2, H2S, and NO2 gases, the change of

  11. [Particulate matter adsorption capacity of 10 evergreen species in Beijing].

    PubMed

    Wang, Bing; Zhang Wei-kang; Niu, Xiang; Wang, Xiao-yan

    2015-02-01

    In the atmosphere, high concentrations of air particles PM (Particulate matter) cause not only environmental pollution, but also serious harm to human body. Green plants as an air filter, can effectively improve the air quality in urban and suburb, and protect human health. Therefore, it is necessary to understand the adsorption capacity of air particulate matter of different species. Based on aerosol generator (QRJZFSQ-I), the leaf surface of ten plants including six evergreen trees and four evergreen shrubs were measured to determine the atmosphere adsorption (TSP, PM10, PM2.5 and PM10) capacity in Beijing, the results showed that: (1) There was obvious difference in the PM adsorption capacity of the leaf surface of different species, the highest were Cedrus deodara and Pinus tabuliformis, which were (18.95 ± 0.71) ?g x cm(-2) and (14.61 ± 0.78) ?g x cm(-2) respectively, while Abiesfabri was the minimum, which was (8.02 ± 0.4) ?g x cm(-2); (2) There was also difference in the per unit leaf area particulate adhesion ability among different tree species, the tree species with the strongest leaf PM10 adhesion ability were Pinus tabulformis and Cedrus deodara, those with the strongest leaf PM2.5 adhesion ability were Cedrus deodara, Juniperus procumbens , Juniperus chinensis cv. kaizuka and Pinus tabuliformis, while those with the strongest leaf PM10 adhesion ability were Cedrus deodara, Juniperus procumbens, Abies fabri and Pinus tabuliformis; (3) The proportions of particulate matters (PM10 and PM2.5) in TSP were different. PM10 had mainly two kinds of trends in April-June, one was firstly decreasing and then increasing, with the main tree type of the shrub species; and the other was increasing, with the main tree type of the tree species. But this change trend was not obvious in PM2.5. PMID:26031064

  12. In vivo and In vitro Assessment of Particulate Matter Toxicology

    Microsoft Academic Search

    Umme S. Akhtar; Jeremy A. Scott; Amanda Chu; Greg J. Evans

    \\u000a Exposure to ambient particulate matter (PM) can have profound adverse effects on human health. Epidemiology studies have revealed\\u000a associations between ambient PM and health effects ranging from increased hospital admissions to increased mortality rate.\\u000a Factors such as particle size, surface area, and composition appear to influence how the body reacts to the inhaled PM. In\\u000a vivo studies using humans and

  13. Measurement of fine particulate matter using electron microscopy techniques

    Microsoft Academic Search

    Gary S Casuccio; Steven F Schlaegle; Traci L Lersch; Gerald P Huffman; Yuanzhi Chen; Naresh Shah

    2004-01-01

    Ambient fine particulate matter, defined as material with an aerodynamic diameter less than or equal to 2.5 ?m (PM2.5), comprises a broad range of primary and secondary particles that are dispersed through the atmosphere from a variety of sources. Attention has recently shifted to investigating ambient PM2.5 because fine particles are thought to have a greater influence on health effects.

  14. Hyperspectral imaging applied to complex particulate solids systems

    NASA Astrophysics Data System (ADS)

    Bonifazi, Giuseppe; Serranti, Silvia

    2008-04-01

    HyperSpectral Imaging (HSI) is based on the utilization of an integrated hardware and software (HW&SW) platform embedding conventional imaging and spectroscopy to attain both spatial and spectral information from an object. Although HSI was originally developed for remote sensing, it has recently emerged as a powerful process analytical tool, for non-destructive analysis, in many research and industrial sectors. The possibility to apply on-line HSI based techniques in order to identify and quantify specific particulate solid systems characteristics is presented and critically evaluated. The originally developed HSI based logics can be profitably applied in order to develop fast, reliable and lowcost strategies for: i) quality control of particulate products that must comply with specific chemical, physical and biological constraints, ii) performance evaluation of manufacturing strategies related to processing chains and/or realtime tuning of operative variables and iii) classification-sorting actions addressed to recognize and separate different particulate solid products. Case studies, related to recent advances in the application of HSI to different industrial sectors, as agriculture, food, pharmaceuticals, solid waste handling and recycling, etc. and addressed to specific goals as contaminant detection, defect identification, constituent analysis and quality evaluation are described, according to authors' originally developed application.

  15. Engine exhaust particulate and gas phase contributions to vascular toxicity.

    PubMed

    Campen, Matthew; Robertson, Sarah; Lund, Amie; Lucero, Joann; McDonald, Jacob

    2014-05-01

    Cardiovascular health effects of near-roadway pollution appear more substantial than other sources of air pollution. The underlying cause of this phenomenon may simply be concentration-related, but the possibility remains that gases and particulate matter (PM) may physically interact and further enhance systemic vascular toxicity. To test this, we utilized a common hypercholesterolemic mouse model (Apolipoprotein E-null) exposed to mixed vehicle emission (MVE; combined gasoline and diesel exhausts) for 6?h/d?×?50?d, with additional permutations of removing PM by filtration and also removing gaseous species from PM by denudation. Several vascular bioassays, including matrix metalloproteinase-9 protein, 3-nitrotyrosine and plasma-induced vasodilatory impairments, highlighted that the whole emissions, containing both particulate and gaseous components, was collectively more potent than MVE-derived PM or gas mixtures, alone. Thus, we conclude that inhalation of fresh whole emissions induce greater systemic vascular toxicity than either the particulate or gas phase alone. These findings lend credence to the hypothesis that the near-roadway environment may have a more focused public health impact due to gas-particle interactions. PMID:24730681

  16. ENGINE EXHAUST PARTICULATE AND GAS PHASE CONTRIBUTIONS TO VASCULAR TOXICITY

    PubMed Central

    Campen, Matthew; Robertson, Sarah; Lund, Amie; Lucero, Joann; McDonald, Jacob

    2014-01-01

    Cardiovascular health effects of near-roadway pollution appear more substantial than other sources of air pollution. The underlying cause of this phenomenon may simply be concentration-related, but the possibility remains that gases and particulate matter (PM) may physically interact and further enhance systemic vascular toxicity. To test this, we utilized a common hypercholesterolemic mouse model (Apolipoprotein E-null) exposed to mixed vehicular emissions (MVE; combined gasoline and diesel exhausts) for 6 h/d × 50 days, with additional permutations of removing PM by filtration and also removing gaseous species from PM by denudation. Several vascular bioassays, including matrix metalloproteinase 9 (MMP9) protein, 3-nitrotyrosine, and plasma-induced vasodilatory impairments, highlighted that the whole emissions, containing both particulate and gaseous components, was collectively more potent than MVE-derived PM or gas mixtures, alone. Thus, we conclude that inhalation of fresh whole emissions induce greater systemic vascular toxicity than either the particulate or gas phase alone. These findings lend credence to the hypothesis that the near-roadway environment may have a more focused public health impact due to gas-particle interactions. PMID:24730681

  17. Anthropogenic contribution of magnetic particulates in urban roadside dust

    NASA Astrophysics Data System (ADS)

    Kim, Wonnyon; Doh, Seong-Jae; Yu, Yongjae

    Environmental magnetism parameters have been optimized as qualitative proxy indicators of the distribution of anthropogenic particulates, heavy metals and/or organic materials. In the present study, we propose a quantitative magnetic proxy which is suitable for the monitoring of spatial and temporal pollution patterns in urban areas. A total of 1353 roadside dust samples were collected from Seoul, Korea for 13 months. Thermomagnetic data and intensive electron microscopy identified a predominance of carbon-bearing iron-oxides, indicating that anthropogenic particulates mostly originated from fossil fuel combustions. To quantify anthropogenic particulates, an apparent magnetic concentration [AMC O=observed saturation magnetization(M)/MofFeO(=92.36Amkg)] was calculated. AMC O showed distinctive spatial and seasonal dependences: highest in industrial areas and lowest in park areas; and maximum in winter and minimum in summer. Seasonal mapping using AMC O illustrated that industries in southwestern Seoul were the major pollution source. In addition, dominant westerly winds possibly transported pollutants along topographically lower areas in Seoul.

  18. The constitutive behaviour of strong cohesive particulate gels in compression

    E-print Network

    A. A. Aziz; R. Buscall; R. de Kretzer; M. Kristjansson; P. J. Scales; A. D. Stickland; H-E Teo; S. P. Usher; K. Keiding

    2015-02-15

    A simple and popular constitutive model used to describe the compressional strength of a consolidating strongly cohesive particulate gel is tested further with new experimental data. Strong cohesive particulate gels have variously been described as being ratchet (poro) elastic, on the one hand, and as having a yield stress in compression, on the other, to the point where same groups of workers have used both descriptions at one time or another. The dichotomy is real though as such gels do show a hitherto somewhat puzzling elastic-plastic duality. This can be explained in part by the strong concentration dependence of the modulus since this leads to irreversible volumetric strain-hardening, in effect, the ratchet; but only in small part. The real problem seems to be that, until very recently, most work on consolidation has neglected what what Michaels and Bolger told us to do over 50 years ago, viz. to take into wall adhesion into account, most cohesive particulate gels being adhesive too. Since wall adhesive failure is plastic in character, the simplest non-linear elastic model of compressive strength can be combined with the simplest possible model of wall debonding to produce a approximate complete constitutive description. Examples of the use of such a description in detailed modelling of consolidation equilibrium can be found in refs 10-12. Consolidation dynamics with wall adhesion is a substantial modelling challenge remaining to be tackled.

  19. Profile sampling to characterize particulate lead risks in potable water.

    PubMed

    Clark, Brandi; Masters, Sheldon; Edwards, Marc

    2014-06-17

    Traditional lead (Pb) profiling, or collecting sequential liters of water that flow from a consumer tap after a stagnation event, has recently received widespread use in understanding sources of Pb in drinking water and risks to consumer health, but has limitations in quantifying particulate Pb risks. A new profiling protocol was developed in which a series of traditional profiles are collected from the same tap at escalating flow rates. The results revealed marked differences in risks of Pb exposure from one consumer home to another as a function of flow rate, with homes grouped into four risk categories with differing flushing requirements and public education to protect consumers. On average, Pb concentrations detected in water at high flow without stagnation were at least three to four times higher than in first draw samples collected at low flow with stagnation, demonstrating a new "worst case" lead release scenario, contrary to the original regulatory assumption that stagnant, first draw samples contain the highest lead concentrations. Testing also revealed that in some cases water samples with visible particulates had much higher Pb than samples without visible particulates, and tests of different sample handling protocols confirmed that some EPA-allowed methods would not quantify as much as 99.9% of the Pb actually present (avg. 27% of Pb not quantified). PMID:24865841

  20. Cell-mediated immunity to soluble and particulate inhaled antigens

    PubMed Central

    Hill, J. O.; Burrell, R.

    1979-01-01

    In order to determine the influence of an antigen's physical properties on the development of cell-mediated immunity (CMI) in the lung following aerosol immunization, human serum albumin (HSA) was prepared in either a soluble or a particulate form, the latter being coupled to respirable, carboxylated latex beads. Antigen was administered via an aerosol to groups of guinea-pigs, twice weekly for up to 4 weeks. Additional groups of animals served as unexposed and unconjugated latex controls. Lymphoid cells for CMI assays were isolated from the lung by bronchopulmonary lavage and from blood for use in mitogen- and antigen-induced lymphocyte transformation assays, as well as indirect macrophage migration inhibition tests. Particulate HSA-exposed animals yielded the highest numbers of free lung cells containing predominantly macrophages, with up to 33% lymphocytes. These were followed by the latex control, soluble HSA and unexposed control groups, respectively. Only the animals exposed to particulate HSA had evidence of antigen reactivation in the lung cell populations as measured by lymphocyte stimulation assays. In contrast, a response to polyclonal mitogens was found only in animals exposed to antigen in a soluble form. Data from macrophage depletion experiments suggest that the antigenicity of inhaled antigens may be due to the types and numbers of cells responding to the stimulus, and the subsequent role the alveolar macrophage may play in the modulation of cellular immunity. PMID:393444

  1. Vertical and lateral transport of particulate radiocesium off Fukushima.

    PubMed

    Otosaka, Shigeyoshi; Nakanishi, Takahiro; Suzuki, Takashi; Satoh, Yuhi; Narita, Hisashi

    2014-11-01

    Transport processes of particulate radiocesium were investigated using a sediment trap deployed at about 100 km east of the Fukushima Daiichi Nuclear Power Plant. A sediment trap was installed at 873 m depth of the station (119 m above the bottom), and time-series sampling of sinking particles was carried out from August, 2011 to June, 2013. The accident-derived radiocesium was detected from sinking particles over two years after the accident. Observed 137Cs flux was highest in September 2011 (98 mBq m(-2) day(-1): decay-corrected to March 11, 2011), and decreased over time with seasonal fluctuations. Particulate fluxes of radiocesium were mainly affected by two principal processes. One was the rapid sinking of radiocesium-bound particles (moderate mode). This mode was dominant especially in the early postaccident stage, and was presumed to establish the distribution of radiocesium in the offshore seabed. Another mode was observed in winter, and secondary transport of particles attributed to turbulence near the seabed increased fluxes of particulate radiocesium (turbulence mode). Although the latter process would not drastically change the distribution of sedimentary radiocesium in the short term, attention should be paid as this key process redistributing the accident-derived radiocesium may cumulatively affect the long-term distribution. PMID:25310600

  2. Bioaccessibility of palladium and platinum in urban aerosol particulates

    NASA Astrophysics Data System (ADS)

    Puls, Christoph; Limbeck, Andreas; Hann, Stephan

    2012-08-01

    To evaluate potential health hazards caused by environmental Platinum Group Elements (PGEs), bioaccessibility of the metals in question needs to be assessed. To gain appropriate data, airborne particulate matter samples of different size fractions (total suspended particles as well as PM10 and PM2.5) were taken in downtown Vienna, an urban site primarily polluted by traffic. Total PGE concentrations in these samples were in the low picogram per cubic meter range, as determined by ID-ICP-MS after microwave digestion. For elimination of elements interfering with the accurate quantification, the digested samples were subjected to a cleaning procedure involving cation exchange. For determination of the bioaccessible fraction, it was assumed that inhaled particles are removed from the respiratory system by mucociliary clearance and subsequently ingested. Accordingly, the solubility of PGE in synthetic gastric juice was investigated by batch extraction of particulate matter samples followed by microwave assisted UV-digestion, cation exchange cleanup and ID-ICP-MS. The acquired data was used to calculate the bioaccessible fraction of Pd and Pt in airborne particulate matter. Average GIT-extractable fractions for Pd and Pt in TSP were 41% and 27%, in PM10 34% and 26%, respectively, thus exceeding previously determined values for bioaccessibility of PGE from ground catalyst materials by up to an order of magnitude.

  3. High Diversity of Fungi in Air Particulate Matter

    NASA Astrophysics Data System (ADS)

    Fröhlich-Nowoisky, J.; Despres, V. R.; Pöschl, U.

    2009-04-01

    Fungal spores account for large proportions of air particulate matter, and they influence the hydrological cycle and climate as nuclei for water droplets and ice crystals in clouds, fog and precipitation. Moreover, some fungi are major pathogens and allergens. The diversity of airborne fungi is, however, hardly known. By DNA analysis we found pronounced differences in the relative abundance and seasonal cycles of various groups of fungi in coarse and fine particulate matter, with more plant pathogens in the coarse and more human pathogens and allergens in the respirable fine particle fraction (< 3 µm). Moreover, the ratio of Basidiomycota to Ascomycota was found to be much higher than previously assumed, which might also apply to the biosphere. References: Després, V.R., J.F. Nowoisky, M. Klose, R. Conrad, M.O. Andreae, U. Pöschl, Characterization of primary biogenic aerosol particles in urban, rural, and high-alpine air by DNA sequence and restriction fragment analysis of ribosomal RNA genes, Biogeosciences, 4, 1127-1141, 2007. Elbert, W., P. E. Taylor, M. O. Andreae, U. Pöschl, Contribution of fungi to primary biogenic aerosols in the atmosphere: wet and dry discharged spores, carbohydrates, and inorganic ions, Atmospheric Chemistry and Physics, 7, 4569-4588, 2007. Fröhlich-Nowoisky, J. Despres, V.R., Pöschl, U.: High diversity of fungi in air particulate matter, Proceedings of the National Academy of Sciences, submitted, 2008.

  4. Characterization of chemical and particulate emissions from aircraft engines

    NASA Astrophysics Data System (ADS)

    Agrawal, Harshit; Sawant, Aniket A.; Jansen, Karel; Wayne Miller, J.; Cocker, David R.

    This paper presents a series of measurements from four on-wing, commercial aircraft engines, including two newer CFM56-7 engines and two earlier CFM56-3 engines. Samples were collected from each engine using a probe positioned behind the exhaust nozzle of the aircraft, chocked on a concrete testing pad. The emission factors for particulate matter mass, elemental and organic carbon, carbonyls, polycyclic aromatic hydrocarbons, n-alkanes, dioxins, metals and ions are reported for four different engine power setting modes. The emissions indices of particulate matter, elemental and organic carbon are highly power dependent for these engines. Particulate matter emission indices (g kg -1 fuel) are found to increase from 1.1E-02 to 2.05E-01 with increase in power from idle to 85%. The elemental carbon to organic carbon varies from 0.5 to 3.8 with change in power from idle to 85%. The carbonyl emissions are dominated by formaldehyde. The emission index of formaldehyde ranges from 2.3E-01 to 4.8E-01 g kg -1 fuel. The distribution of metals depends on the difference in the various engines. The dioxin emissions from the aircraft engines are observed to be below detection limit.

  5. Particulate matter and manganese exposures in Toronto, Canada

    NASA Astrophysics Data System (ADS)

    Pellizzari, E. D.; Clayton, C. A.; Rodes, C. E.; Mason, R. E.; Piper, L. L.; Fort, B.; Pfeifer, G.; Lynam, D.

    Methylcyclopentadienyl manganese tricarbonyl (MMT) is a manganese-based gasoline additive used to enhance automobile performance. MMT has been used in Canadian gasoline for about 20 yr. Because of the potential for increased levels of Mn in particulate matter resulting from automotive exhausts, a large-scale population-based exposure study (˜1000 participant periods) was conducted in Toronto, Canada, to estimate the distribution of 3-day average personal exposures to particulate matter (PM 2.5 and PM 10) and Mn. A stratified, three-stage, two-phase probability, longitudinal sample design of the metropolitan population was employed. Residential indoor and outdoor, and ambient levels (at a fixed site and on a roof) of PM 2.5, PM 10, and Mn were also measured. Supplementary data on traffic counts, meteorology, MMT levels in gasoline, personal occupations, and activities (e.g. amount of vehicular usage) were collected. Overall precision (%RSD) for analysis of duplicate co-located samples ranged from 2.5 to 5.0% for particulate matter and 3.1 to 5.5% for Mn. The detection limits were 1.47 and 3.45 ?g m -3 for the PM 10 and PM 2.5 fractions, respectively, and 5.50 and 1.83 ng m -3 for Mn in PM 10 and PM 2.5, respectively. These low detection limits permitted the reporting of concentrations for >98% of the samples. For PM 10, the personal particulate matter levels (median 48.5 ?g m -3) were much higher than either indoor (23.1 ?g m -3) or outdoor levels (23.6 ?g m -3). The median levels for PM 2.5 for personal, indoor, and outdoor were 28.4, 15.4 and 13.2 ?g m -3, respectively. The correlation between PM 2.5 personal exposures and indoor concentrations was high (0.79), while correlations between personal and the outdoor, fixed site and roof site were low (0.16-0.27). Indoor Mn concentration distributions (in PM 2.5 and PM 10), unlike particulate matter, exhibited much lower and less variable levels that the corresponding outdoor data. The median personal exposure was 8.0 ng m -3, compared with 4.7 and 8.6 ng m -3, respectively, for the indoor and outdoor distributions. The highest correlations occurred for personal vs indoor data (0.56) and for outdoor vs roof site data (0.66), and vs fixed site data (0.56). The concentration of Mn in particulate matter, expressed in ppm (w/w), revealed that the fixed site was the highest, followed by the roof site, outdoor, indoor, and personal. The personal and indoor data showed a statistically significant correlation (0.68) while all other correlations between personal or indoor data and outdoor or fixed-site data were quite small. The low correlations of personal and indoor levels with outdoor levels suggest that different sources in the indoor and outdoor microenvironments produce particle matter with dissimilar composition. The correlation results indicate that neither the roof- nor fixed-site concentrations can adequately predict personal particulate matter or Mn exposures.

  6. Impact assessment of respirable suspended particulate matter from diesel generator sets used for pumping station.

    PubMed

    Talwar, B; Pipalatkar, P; Gajghate, D G; Nema, P

    2010-10-01

    Prediction of respirable suspended particulate matter impacts of diesel generator sets used for pumping station has been made using meteorological data, information on stack characteristics and emission rate, baseline ambient particulate matter and Industrial Source Complex Short Term (ISCST-3) model. It is observed that particulate matter emission from pumping station-S workplace diesel generator sets ranged from 2.4 to 436.5 mg Nm?³ and while at pumping station-C, it ranged from 23.2 to 186.5 mg Nm?³. The predicted and ambient respirable suspended particulate matter concentrations are below the national air quality standard for respirable suspended particulate matter in a mixed industrial area. Metals contents in respirable suspended particulate matter indicate the origin of crustal and mobile sources. Therefore, the impact of diesel generator sets used for pumping of crude oil on local air quality would be acceptable. PMID:20700577

  7. Analysis of manganese particulates from automotive decomposition of methylcyclopentadienyl manganese tricarbonyl

    Microsoft Academic Search

    C. Colmenares; Steven Deutsch; Cheryl Evans; A. J. Nelson; Louis J. Terminello; John G. Reynolds; Joseph W. Roos; Isaac L. Smith

    1999-01-01

    Particulates have been collected and analyzed from automotive vehicles operating on fuel containing the organometallic antiknock additive methylcyclopentadienyl manganese tricarbonyl. Electron spectroscopy for chemical analysis and L-edge X-ray absorption spectroscopy were used to study and identify the manganese species present in these emitted particulates. Results show that respirable size particulates with a mass median aerodynamic diameter of 2.5 ?m or

  8. Preliminary studies of airborne particulate emmisions from the Ampellum S.A. copper smelter, Zlatna, Romania

    Microsoft Academic Search

    Ben J. Williamson; Nicolae Har; William O. Purvis; Ana Maria Rusu

    2012-01-01

    Preliminary studies have been carried on the characterization of particulate emissions from the Ampellum S.A. copper smelter in the town of Zlatna, Romania. The particulates studied were collected on polycarbonate filters using air pump apparatus and on the surfaces of lichens. Mass of total suspended particulates (TSP) and PM10 varied from 19 to 230 ?g\\/m3 and 3 to 146 ?g\\/m3,

  9. Uptake of particulate vaccine adjuvants by dendritic cells activates the NALP3 inflammasome

    Microsoft Academic Search

    Fiona A. Sharp; Darren Ruane; Benjamin Claass; Emma Creagh; James Harris; Padma Malyala; Manomohan Singh; Derek T. O'Hagan; Virginie Pétrilli; Jurg Tschopp; Luke A. J. O'Neill; Ed C. Lavelle

    2009-01-01

    Many currently used and candidate vaccine adjuvants are particulate in nature, but their mechanism of action is not well understood. Here, we show that particulate adjuvants, including biodegradable poly(lactide-co-glycolide) (PLG) and polystyrene microparticles, dramatically enhance secretion of interleukin-1beta (IL-1beta) by dendritic cells (DCs). The ability of particulates to promote IL-1beta secretion and caspase 1 activation required particle uptake by DCs

  10. Seasonal variability of bacteria in fine and coarse urban air particulate matter

    Microsoft Academic Search

    Andrea Franzetti; Isabella Gandolfi; Eleonora Gaspari; Roberto Ambrosini; Giuseppina Bestetti

    2011-01-01

    The current knowledge about the microbial communities associated with airborne particulate matter, particularly in urban areas,\\u000a is limited. This study aims to fill this gap by describing the microbial community associated with coarse (PM10) and fine\\u000a (PM2.5) particulate matter using pyrosequencing. Particulate matter was sampled on Teflon filters over 3 months in summer\\u000a and 3 months in winter in Milan (Italy), and

  11. Micro-Flow Imaging: Flow Microscopy Applied to Sub-visible Particulate Analysis in Protein Formulations

    Microsoft Academic Search

    Deepak K. Sharma; Dave King; Peter Oma; Clark Merchant

    2010-01-01

    The need to monitor, measure, and control sub-visible proteinaceous particulates in biopharmaceutical formulations has been\\u000a emphasized in recent publications and commentaries. Some of these particulates can be highly transparent, fragile, and unstable.\\u000a In addition, for much of the size range of concern, no practical measurement method with adequate sensitivity and repeatability\\u000a has been available. A complication in measuring protein particulates

  12. Development of a hot isostatic pressing process for manufacturing silicon carbide particulate reinforced iron

    E-print Network

    Oakeson, David Oscar

    1992-01-01

    Surface of Specimen 9 Figure 63 Fracture Surface of Specimen 13 112 112 CIGLPTER I ISTRODUCTIOM Description of the Problem This thesis addresses the issue of hot isostatic pressing (HIP ing) particulate reinf orced metal matrix composites (MMCs... LITERATURE REVIEW Particulate vs. Continuous Fiber Reinforced Metal Matrix Composi tes Particulate reinforced metal matrix composites (MMCs) are older than continuous fiber reinforced MMCs, and are popular in the tool and die industry. In the past three...

  13. Modeling particulate matter emissions during mineral loading process under weak wind simulation.

    PubMed

    Zhang, Xiaochun; Chen, Weiping; Ma, Chun; Zhan, Shuifen

    2013-04-01

    The quantification of particulate matter emissions from mineral handling is an important problem for the quantification of global emissions on industrial sites. Mineral particulate matter emissions could adversely impact environmental quality in mining regions, transport regions, and even on a global scale. Mineral loading is an important process contributing to mineral particulate matter emissions, especially under weak wind conditions. Mathematical models are effective ways to evaluate particulate matter emissions during the mineral loading process. The currently used empirical models based on the form of a power function do not predict particulate matter emissions accurately under weak wind conditions. At low particulate matter emissions, the models overestimated, and at high particulate matter emissions, the models underestimated emission factors. We conducted wind tunnel experiments to evaluate the particulate matter emission factors for the mineral loading process. A new approach based on the mathematical form of a logistical function was developed and tested. It provided a realistic depiction of the particulate matter emissions during the mineral loading process, accounting for fractions of fine mineral particles, dropping height, and wind velocity. PMID:23425793

  14. Particulate carbon and nitrogen and suspended particulate matter in the Sacramento River at Rio Vista, California, January 3 - May 26, 1983 and October 31, 1983 - November 29, 1984

    USGS Publications Warehouse

    Hager, Stephen W.

    1994-01-01

    Particulate matter was collected at Rio Vista, California, in two study periods; the first, from January 3 to May 26, 1983; the second from October 31, 1983 to November 29, 1984. Concentrations of suspended particulate matter were measured gravimetrically on silver membrane filters. The pooled standard deviation on replicated samples was 1.4 mg/L, giving a coefficient of variation of 5.7 percent. Concentrations of particulate carbon and nitrogen were measured during a Perkin-Elmer model 240C elemental analyzer to combust material collected on glass fiber filters. Refrigeration of samples prior to filtration was shown to be a likely influence on precision of duplicate analyses. Median deviations between duplicates for carbon were 5.4 percent during the first study period and 8.9 percent during the second. For nitrogen, median deviations were 4.9 percent and 7.2 percent, respectively. This report presents the data for concentrations of suspended particulate material, the duplicate analyses for particulate carbon and nitrogen, and the volumes of sample filtered for the particulate carbon and nitrogen analyses for both studies. Not all samples collected during the second study have been analyzed for particulate carbon and nitrogen.

  15. Dissolved and particulate carbohydrates in contrasting marine sediments

    NASA Astrophysics Data System (ADS)

    Burdige, D. J.; Skoog, A.; Gardner, K.

    2000-03-01

    Dissolved and particulate carbohydrates were examined in contrasting Chesapeake Bay (estuarine) and mid-Atlantic shelf/slope break (continental margin) sediments. Particulate carbohydrates (PCHOs) represented ˜5-9% of the total sediment particulate organic carbon (POC), and PCHO remineralization appeared to be a similar fraction of total sediment carbon oxidation (or C ox). When these results are compared with results from other coastal sediments and a pelagic turbidite, PCHO remineralization (as a percentage of C ox) did not vary by more than a factor of ˜2-3 over a 3-4 order of magnitude range in C ox values. The causes of this are not well understood, but may be related to specific effects associated with the remineralization of highly altered organic matter mixtures under aerobic conditions. Dissolved carbohydrates (DCHOs) in these sediment pore waters ranged from ˜30 to 400 ?M, increased with depth in a manner similar to total DOC, and represented ˜10 to 55% of pore water DOC. In Chesapeake Bay sediments this percentage decreased with sediment depth, while in these continental margin sediments it was constant (upper 30 cm). Of the DCHOs in these pore waters ˜30 to 50% could be identified as individual aldoses (monomeric neutral sugars), and total aldose yields (individual aldoses as a percentage of total DOC) were higher in these continental margin sediment pore waters (>9%) than they were in the estuarine sediment pore waters (<5%). A comparison of DCHO and PCHO concentrations in these sediments indicates that their concentrations are uncoupled, and that pore water DCHO concentrations are primarily controlled by sediment remineralization processes. Pore water DCHOs appeared to be preferentially found in the high molecular weight (HMW) DOC pool, and likely occur as some of the initial HMW intermediates produced and consumed during sediment POC remineralization. These results also support past suggestions about the differing controls on carbon remineralization processes in continental margin versus estuarine sediments.

  16. Particulate Matter Concentrations in the San Francisco Bay Area, California

    NASA Astrophysics Data System (ADS)

    Souksavath, V.; Williams, J.; Powell, M.; Campell, M.; Almarez, A.; Almarez, M.

    2008-12-01

    Particulate pollution is a serious problem that is estimated to cause between 20,000 and 50,000 deaths per year in the US alone. Particulate matter 2.5 micrometers diameter or less is small enough to pass from the lungs to the blood stream, and in the long run, may contribute to causing cancer and other life-threatening diseases. Although particles as large as 10 micrometers tend to get trapped by the nose and throat, and thus never enter the lungs, they can still cause trouble for those who have breathing-related problems. Our research was aimed at determining the levels of large and small particles in places with high densities of people, as well as locations with a high volume of vehicle traffic. Using the Fluke 893 Particle Counter, we measured particulate matter in a transect that spanned the San Francisco Bay Area. We collected data at diverse sites including: Bay Area Rapid Transit (BART) stations in Oakland and San Francisco; all levels of a large parking garage in Emeryville; a number of local construction sites; and several heavily populated shopping areas in San Francisco. Though preliminary in nature, analysis of our data indicates that high concentrations of particles under 2.5 micrometers are found at the Coliseum BART station in Oakland, as well as in association with areas of high vehicle traffic flow. High concentrations of large particles are found near construction sites. Guided by these preliminary results, we plan to continue collecting data throughout the Fall to determine the causes of patterns that we have observed, as well as assess any changes that occur over time.

  17. Particulate Matter Concentrations in East Oakland's High Street Corridor

    NASA Astrophysics Data System (ADS)

    Lei, P.; Jackson, J.; Lewis, R.; Marigny, A.; Mitchell, J. D.; Nguyen, R.; Philips, B.; Randle, D.; Romero, D.; Spears, D.; Telles, C.; Weissman, D.

    2012-12-01

    Particulate matter (PM) is a complex mixture of small solid pieces and/or liquid droplets in the air. High concentrations of PM can pose a serious health hazard because inhalation can result in breathing problems and/or aggravate asthma. Long term exposure can increase the likelihood of respiratory problems like asthma and emphysema as well as cancer. The smaller the particles, the deeper they can get into the respiratory system. For this reason, the smallest particles, those smaller than 2.5 micrometers in diameter (PM2.5), are the most dangerous. PM2.5 is largely emitted from motor vehicles burning fuels that don't break down fully. Our research team investigated the levels of PM2.5 as well as particles smaller than 10 micrometers (PM10) and total suspended particulate (TSP) along the northeast-southwest trending High Street Corridor, near Fremont High School in East Oakland, California. Using the Aerocet 531 mass particle counter, team members walked through neighborhoods and along major roads within a 1 mile radius of Fremont High School. The Aerocet 531 recorded two minute average measurements of all the relevant PM sizes, which are reported in mg/m3. Measurements were consistently taken in the morning, between 8:30 and 11:30 am. Preliminary results indicate maximum readings of all PM sizes at sites that are in close proximity to a major freeway (Interstate-880). These results support our initial hypothesis that proximity to major roads and freeways, especially those with high diesel-fuel burning truck traffic, would be the primary factor affecting PM concentration levels. Preliminary median and maximum readings all suggest particulate matter levels below what the EPA would consider unhealthy or risky.

  18. Preventing Molecular and Particulate Infiltration in a Confined Volume

    NASA Technical Reports Server (NTRS)

    Scialdone, John J.

    1999-01-01

    Contaminants from an instrument's self-generated sources or from sources external to the instrument may degrade its critical surfaces and/or create an environment which limits the instrument's intended performance. Analyses have been carried out on a method to investigate the required purging flow of clean, dry gas to prevent the ingestion of external contaminants into the instrument container volume. The pressure to be maintained and the required flow are examined in terms of their effectiveness in preventing gaseous and particulate contaminant ingestion and abatement of self-generated contaminants in the volume. The required venting area or the existing volume venting area is correlated to the volume to be purged, the allowable pressure differential across the volume, the external contaminant partial pressure, and the sizes of the ambient particulates. The diffusion of external water vapor into the volume while it was being purged was experimentally obtained in terms of an infiltration time constant. That data and the acceptable fraction of the outside pressure into the volume indicate the required flow of purge gas expressed in terms of volume change per unit time. The exclusion of particulates is based on the incoming velocity of the particles and the exit flow speed and density of the purge gas. The purging flow pressures needed to maintain the required flows through the vent passages are indicated. The purge gas must prevent or limit the entrance of the external contaminants to the critical locations of the instrument. It should also prevent self- contamination from surfaces, reduce material outgassing, and sweep out the outgassed products. Systems and facilities that can benefit from purging may be optical equipment, clinical facilities, manufacturing facilities, clean rooms, and other systems requiring clean environments.

  19. Estimation of Particulate Mass and Manganese Exposure Levels among Welders

    PubMed Central

    Hobson, Angela; Seixas, Noah; Sterling, David; Racette, Brad A.

    2011-01-01

    Background: Welders are frequently exposed to Manganese (Mn), which may increase the risk of neurological impairment. Historical exposure estimates for welding-exposed workers are needed for epidemiological studies evaluating the relationship between welding and neurological or other health outcomes. The objective of this study was to develop and validate a multivariate model to estimate quantitative levels of welding fume exposures based on welding particulate mass and Mn concentrations reported in the published literature. Methods: Articles that described welding particulate and Mn exposures during field welding activities were identified through a comprehensive literature search. Summary measures of exposure and related determinants such as year of sampling, welding process performed, type of ventilation used, degree of enclosure, base metal, and location of sampling filter were extracted from each article. The natural log of the reported arithmetic mean exposure level was used as the dependent variable in model building, while the independent variables included the exposure determinants. Cross-validation was performed to aid in model selection and to evaluate the generalizability of the models. Results: A total of 33 particulate and 27 Mn means were included in the regression analysis. The final model explained 76% of the variability in the mean exposures and included welding process and degree of enclosure as predictors. There was very little change in the explained variability and root mean squared error between the final model and its cross-validation model indicating the final model is robust given the available data. Conclusions: This model may be improved with more detailed exposure determinants; however, the relatively large amount of variance explained by the final model along with the positive generalizability results of the cross-validation increases the confidence that the estimates derived from this model can be used for estimating welder exposures in absence of individual measurement data. PMID:20870928

  20. AIR QUALITY: MERCURY, TRACE ELEMENTS, AND PARTICULATE MATTER CONFERENCE

    SciTech Connect

    John H. Pavlish; Steven A. Benson

    1999-07-01

    This final report summarizes the planning/preparation, facilitation, and outcome of the conference entitled ''Air Quality: Mercury, Trace Elements, and Particulate Matter'' that was held December 1-4, 1998, in McLean, Virginia (on the outskirts of Washington, DC). The goal of the conference was to bring together industry, government, and the research community to discuss the critical issue of how air quality can impact human health and the ecosystem, specifically hazardous air pollutants and fine airborne particles; available and developing control technologies; strategies and research needs; and an update on federal and state policy and regulations, related implementation issues, and the framework of the future.

  1. Prospecting by sampling and analysis of airborne particulates and gases

    DOEpatents

    Sehmel, G.A.

    1984-05-01

    A method is claimed for prospecting by sampling airborne particulates or gases at a ground position and recording wind direction values at the time of sampling. The samples are subsequently analyzed to determine the concentrations of a desired material or the ratios of the desired material to other identifiable materials in the collected samples. By comparing the measured concentrations or ratios to expected background data in the vicinity sampled, one can select recorded wind directions indicative of the upwind position of the land-based source of the desired material.

  2. Silkworm cocoons inspire models for random fiber and particulate composites

    SciTech Connect

    Chen Fujia; Porter, David; Vollrath, Fritz [Department of Zoology, University of Oxford, Oxford OX1 3PS (United Kingdom)

    2010-10-15

    The bioengineering design principles evolved in silkworm cocoons make them ideal natural prototypes and models for structural composites. Cocoons depend for their stiffness and strength on the connectivity of bonding between their constituent materials of silk fibers and sericin binder. Strain-activated mechanisms for loss of bonding connectivity in cocoons can be translated directly into a surprisingly simple yet universal set of physically realistic as well as predictive quantitative structure-property relations for a wide range of technologically important fiber and particulate composite materials.

  3. Silkworm cocoons inspire models for random fiber and particulate composites

    NASA Astrophysics Data System (ADS)

    Chen, Fujia; Porter, David; Vollrath, Fritz

    2010-10-01

    The bioengineering design principles evolved in silkworm cocoons make them ideal natural prototypes and models for structural composites. Cocoons depend for their stiffness and strength on the connectivity of bonding between their constituent materials of silk fibers and sericin binder. Strain-activated mechanisms for loss of bonding connectivity in cocoons can be translated directly into a surprisingly simple yet universal set of physically realistic as well as predictive quantitative structure-property relations for a wide range of technologically important fiber and particulate composite materials.

  4. Compounds in airborne particulates - Salts and hydrocarbons. [at Cleveland, OH

    NASA Technical Reports Server (NTRS)

    King, R. B.; Antoine, A. C.; Fordyce, J. S.; Neustadter, H. E.; Leibecki, H. F.

    1977-01-01

    Concentrations of 10 polycyclic aromatic hydrocarbons (PAH), the aliphatics as a group, sulfate, nitrate, fluoride, acidity, and carbon in the airborne particulate matter were measured at 16 sites in Cleveland, OH over a 1-year period during 1971 and 1972. Analytical methods used included gas chromatography, colorimetry, and combustion techniques. Uncertainties in the concentrations associated with the sampling procedures, and the analytical methods are evaluated. The data are discussed relative to other studies and source origins. High concentrations downwind of coke ovens for 3,4 benzopyrene are discussed. Hydrocarbon correlation studies indicated no significant relations among compounds studied.

  5. ENGINEERED PARTICULATES FOR CO-FIRING OF DIVERSE FEEDSTOCKS

    SciTech Connect

    Joseph J. McCarthy; Kunal Jain; Hongming Li; Deliang Shi

    2004-03-01

    The goal of this project is to develop a novel methodology for the formation of engineered particulates of energy-relevant material. Specifically, we aim to control interparticle cohesion in such a way as to generate macro-particles or agglomerates of several differing types of primary particles in specific proportions such that they would be of utility for co-firing applications. In Phase I of this project, we used a combination of experimentation and simulation to validate theoretically derived mixing/segregation rules for cohesive granular materials in static systems, flowing systems, and gas-solid systems.

  6. Advanced hybrid particulate collector and method of operation

    DOEpatents

    Miller, Stanley J. (Grand Forks, ND)

    1999-01-01

    A device and method for controlling particulate air pollutants of the present invention combines filtration and electrostatic collection devices. The invention includes a chamber housing a plurality of rows of filter elements. Between each row of filter elements is a grounded plate. Between the grounded plates and the filter elements are electrode grids for creating electrostatic precipitation zones between each row of filter elements. In this way, when the filter elements are cleaned by pulsing air in a reverse direction, the dust removed from the bags will collect in the electrostatic precipitation zones rather than on adjacent filter elements.

  7. Infiltration processing of metal matrix composites using coated ceramic particulates

    NASA Astrophysics Data System (ADS)

    Leon-Patino, Carlos Alberto

    2001-07-01

    A new process was developed to fabricate particulate metal matrix composites (MMCs). The process involves three steps: (1) modifying the particulate surface by metal coating, (2) forming a particulate porous compact; and (3) introducing metal into the channel network by vacuum infiltration. MMCs with different reinforcements, volume fractions, and sizes can be produced by this technique. Powders of alumina and silicon carbide were successfully coated with nickel and copper in preparation for infiltration with molten aluminum. Electroless Ni and Cu deposition was used since it enhances the wettability of the reinforcements for composite fabrication. While Cu deposits were polycrystalline, traces of phosphorous co-deposited from the electroless bath gave an amorphous Ni-P coating. The effect of metal coating on wetting behavior was evaluated at 800°C on plain and metal-coated ceramic plates using a sessile drop technique. The metallic films eliminated the non-wetting behavior of the uncoated ceramics, leading to equilibrium contact angles in the order of 12° and below 58° for Ni and Cu coated ceramics, respectively. The spreading data indicated that local diffusion at the triple junction was the governing mechanism of the wetting process. Precipitation of intermetallic phases in the drop/ceramic interface delayed the formation of Al4C3. Infiltration with molten Al showed that the coated-particulates are suitable as reinforcing materials for fabricating MMCs, giving porosity-free components with a homogeneously distributed reinforcing phase. The coating promoted easy metal flow through the preform, compared to the non-infiltration behavior of the uncoated counterparts. Liquid state diffusion kinetics due to temperature dependent viscosity forces controlled the infiltration process. Microstructural analysis indicated the formation of intermetallic phases such as CuAl 2, in the case of Cu coating, and Ni2Al3 and NiAl 3 when Ni-coated powders were infiltrated. The overall Ni and Cu content increased from bottom to top of the samples due to dissolution of the metal film by the stream of liquid Al during infiltration. The strengths of the Al/Ni-SiC composites, measured by four-point bending, were 205 and 225 MPa for samples reinforced with 78 mum and 49 mum Ni-SiC, respectively. The mode of fracture was mainly controlled by SiC particle fracture.

  8. Low exhaust temperature electrically heated particulate matter filter system

    DOEpatents

    Gonze, Eugene V. (Pinckney, MI); Paratore, Jr., Michael J. (Howell, MI); Bhatia, Garima (Bangalore, IN)

    2012-02-14

    A system includes a particulate matter (PM) filter, a sensor, a heating element, and a control module. The PM filter includes with an upstream end that receives exhaust gas, a downstream end and multiple zones. The sensor detects a temperature of the exhaust gas. The control module controls current to the heating element to convection heat one of the zones and initiate a regeneration process. The control module selectively increases current to the heating element relative to a reference regeneration current level when the temperature is less than a predetermined temperature.

  9. A photometric function for diffuse reflection by particulate materials

    NASA Technical Reports Server (NTRS)

    Meador, W. E.; Weaver, W. R.

    1975-01-01

    A photometric function is proposed to describe the diffuse reflection of radiation by particulate materials. Both multiple scattering and the dominant effects of particle shadowing are included and the function is verified by comparisons with the photometries of laboratory surfaces. Brightness measurements of planetary and other diffusely scattering surfaces can be used to calculate the brightness for geometries other than those used in the measurements and for which the Minnaert function does not apply. The measurements also can be directly related to such surface characteristics as particle size, single-particle albedo, and compactness.

  10. Mechanics/heat-transfer relation for particulate materials. [Quarterly report

    SciTech Connect

    Campbell, C.S.

    1991-07-01

    The major emphasis this quarter has been in two areas. The first is to continue working the bugs out of the new particle pressure transducer. The second was to try and measure the particle pressures generated in a bed of FCC catalyst that is undergoing particulate fluidization. The results indicate that the stabilization of fluidized beds in that regime cannot be explained in terms of particle pressure generation. Instead, consistent with other recent observations,the observations can be explained by a material is that not completely fluidized but, instead, retains much of the properties of a solid and, in particular, can transmit particle pressure like a solid. 2 figs.

  11. Ice core dust particulate by XPS-SEM\\/EDAX

    Microsoft Academic Search

    Zhongqin Li; Gongxuan Lu; Baozhong Liu; Hongxiang Fu; Yu Liu

    1999-01-01

    The ice core dust particulate sampled from Mt. Xixabangma has been analyzed by means of X-ray photoelectron spectrometer (XPS)\\u000a and scanning electron microscope with energy dispersion X-ray analysis (SEM\\/EDAX). The results show that the contents of SO\\u000a 4\\u000a 2?\\u000a and SO\\u000a 4\\u000a 2?\\u000a in the surface layer of the dust are significantly higher than those in the subsurface layer (with

  12. Controlled laser production of elongated articles from particulates

    DOEpatents

    Dixon, Raymond D. (Los Alamos, NM); Lewis, Gary K. (Los Alamos, NM); Milewski, John O. (Santa Fe, NM)

    2002-01-01

    It has been discovered that wires and small diameter rods can be produced using laser deposition technology in a novel way. An elongated article such as a wire or rod is constructed by melting and depositing particulate material into a deposition zone which has been designed to yield the desired article shape and dimensions. The article is withdrawn from the deposition zone as it is formed, thus enabling formation of the article in a continuous process. Alternatively, the deposition zone is moved along any of numerous deposition paths away from the article being formed.

  13. Association of expired nitric oxide with occupational particulate exposure.

    PubMed

    Kim, Jee Young; Wand, Matthew P; Hauser, Russ; Mukherjee, Sutapa; Herrick, Robert F; Christiani, David C

    2003-05-01

    Particulate air pollution has been associated with adverse respiratory health effects. This study assessed the utility of expired nitric oxide to detect acute airway responses to metal-containing fine particulates. Using a repeated-measures study design, we investigated the association between the fractional concentration of expired nitric oxide (F(E)NO) and exposure to particulate matter with an aerodynamic mass median diameter of less than or equal to 2.5 micro m (PM(2.5)) in boilermakers exposed to residual oil fly ash and metal fumes. Subjects were monitored for 5 days during boiler repair overhauls in 1999 (n = 20) or 2000 (n = 14). The Wilcoxon median baseline F(E)NO was 10.6 ppb [95% confidence interval (CI): 9.1, 12.7] in 1999 and 7.4 ppb (95% CI: 6.7, 8.0) in 2000. The Wilcoxon median PM(2.5) 8-hr time-weighted average was 0.56 mg/m(3) (95% CI: 0.37, 0.93) in 1999 and 0.86 mg/m(3) (95% CI: 0.65, 1.07) in 2000. F(E)NO levels during the work week were significantly lower than baseline F(E)NO in 1999 (p < 0.001). A significant inverse exposure-response relationship between log-transformed F(E)NO and the previous workday's PM(2.5) concentration was found in 1999, after adjusting for smoking status, age, and sampling year. With each 1 mg/m(3) incremental increase in PM(2.5) exposure, log F(E)NO decreased by 0.24 (95% CI: -0.38, -0.10) in 1999. The lack of an exposure-response relationship between PM(2.5) exposure and F(E)NO in 2000 could be attributable to exposure misclassification resulting from the use of respirators. In conclusion, occupational exposure to metal-containing fine particulates was associated with significant decreases in F(E)NO in a survey of workers with limited respirator usage. PMID:12727593

  14. Particulate exhaust emissions from an experimental combustor. [gas turbine engine

    NASA Technical Reports Server (NTRS)

    Norgren, C. T.; Ingebo, R. D.

    1975-01-01

    The concentration of dry particulates (carbon) in the exhaust of an experimental gas turbine combustor was measured at simulated takeoff operating conditions and correlated with the standard smoke-number measurement. Carbon was determined quantitatively from a sample collected on a fiberglass filter by converting the carbon in the smoke sample to carbon dioxide and then measuring the volume of carbon dioxide formed by gas chromatography. At a smoke of 25 (threshold of visibility of the smoke plume for large turbojets) the carbon concentration was 2.8 mg carbon/cu m exhaust gas, which is equivalent to an emission index of 0.17 g carbon/kg fuel.

  15. Trace element geochemistry of marine biogenic particulate matter

    SciTech Connect

    Collier, R.W.

    1981-02-01

    Plankton samples were investigated for physical and chemical leaching decomposition to identify the major and trace element composition of particulate carrier phases. The identification of trace element/major element ratios in the biogenic materials was emphasized. The majority of the trace elements in the samples were directly associated with the nonskeletal organic phases of the plankton. Calcium carbonate and opal were not significant carriers for any of the trace elements studied. A refractory phase containing Al and Fe in terrigenous ratios was present in all samples, even from the more remote marine locations.

  16. Strainer assembly for removing solid particulates from oil

    SciTech Connect

    Martin, R.J.

    1992-08-18

    This patent describes a strainer assembly for removing solid particulates from a fluid. It comprises a housing formed as an elbow-shaped conduit having an inlet conduit section terminating in a forwardly extending flange, an enlarged intermediate section, and an outlet conduit section; an opening in a wall of the enlarged intermediate section spaced from and axially aligned with the forwardly extending flange of the inlet conduit section; a support member having a base secured in and sealing the opening; a screen disposed between the support member and the flange of the inlet conduit section.

  17. Determination of natural actinides and plutonium in marine particulate material

    Microsoft Academic Search

    Robert F. Anderson; Alan P. Fleer

    1982-01-01

    The natural actinides ²²⁷Ac, ²²⁸Th, ²³°Th, ²³²Th, ²³⁴Th, ²³¹Pa, ²³⁸U, and ²³⁴U and the ..cap alpha..-emitting plutonium isotopes are determined in samples of suspended marine particulate material and sediments. Analysis involves total dissolution of the samples to allow equilibration of the natural isotopes with added isotope yield monitors followed by coprecipitation of hydrolyzable metals at pH 7 with natural Fe

  18. Hydrophobic to superhydrophobic surface modification using impacting particulate sprays

    NASA Astrophysics Data System (ADS)

    Lau, Chun Yat; Vuong, Thach; Wang, Jingming; Muradoglu, Murat; Liew, Oi Wah; Ng, Tuck Wah

    2014-08-01

    The roughening or structuring of inherently hydrophobic surfaces to possess microscopic and nanoscopic features can transform them to exhibit superhydrophobicity. The use of impacting particulate sprays here eschews specialized reagents and equipments; is simple, inexpensive, and rapid to implement; creates highly repeatable outcomes; and permits selective region transformation via simple masking. With PTFE, the contact angle transforms from 90° to 150°, in which SEM examination reveals erosive wear mechanisms that are dependent on the impingement angle. The process tends to cause the sample to bulge upwards from the treated surface due to elongation there, and can be mitigated by using lower impingement angles in the particulate spray. A finite element model created enables this characteristic to be related to the action of locked-in surface traction forces. The use of adhesive bonding to a rigid base is shown to be an alternative method to reduce the bulging. A second finite model developed allows knowledge of the right adhesive needed for this. In developing substrates for biochemical analysis, the approach offers very small possibilities for unintended synergistic interactions.

  19. On stress relaxation timescales for dense binary particulate systems

    NASA Astrophysics Data System (ADS)

    Mao, Shaolin

    2015-06-01

    We study contact stress relaxation timescales, especially the temporal correlation involved in dense binary particulate systems, which offers insight into the intriguing relationship between the contact stresses and the contact time of particle interactions under non-equilibrium state. The contact time (also referred to as contact age) of a pair of particles is defined by the duration between current time and the instant when the contact was formed. The interspecies inter-particles contact stresses are derived from Liouville's theorem. We apply particle dynamics methods (e.g. molecular dynamics, discrete element method) to simulate 3D dense binary particulate systems with periodic boundary conditions. External perturbation is exerted on the system to balance the dissipation of energy due to the viscoelastic collisions. The contact stresses, Reynolds stresses, and the probability density function of the contact time of particles are predicted at different volume fraction of particles. The obtained stress-strain rate data are used to examine the constitutive relation of macroscopic materials. The study targets the impact of the short-term and the long-term contact/collision on the contact stress relaxation. The simulation results reveal distinct effects of the short-term and the long-term contact/collision on the contact stresses, which have been treated by only an averaged expression of particle interactions in discrete element methods before.

  20. Evolution of force networks in dense particulate media

    NASA Astrophysics Data System (ADS)

    Kramár, Miroslav; Goullet, Arnaud; Kondic, Lou; Mischaikow, Konstantin

    2014-11-01

    We discuss sets of measures with the goal of describing dynamical properties of force networks in dense particulate systems. The presented approach is based on persistent homology and allows for extracting precise, quantitative measures that describe the evolution of geometric features of the interparticle forces, without necessarily considering the details related to individual contacts between particles. The networks considered emerge from discrete element simulations of two-dimensional particulate systems consisting of compressible frictional circular disks. We quantify the evolution of the networks for slowly compressed systems undergoing jamming transition. The main findings include uncovering significant but localized changes of force networks for unjammed systems, global (systemwide) changes as the systems evolve through jamming, to be followed by significantly less dramatic evolution for the jammed states. We consider both connected components, related in a loose sense to force chains, and loops and find that both measures provide a significant insight into the evolution of force networks. In addition to normal, we consider also tangential forces between the particles and find that they evolve in the consistent manner. Consideration of both frictional and frictionless systems leads us to the conclusion that friction plays a significant role in determining the dynamical properties of the considered networks. We find that the proposed approach describes the considered networks in a precise yet tractable manner, making it possible to identify features which could be difficult or impossible to describe using other approaches.

  1. Atmospheric lead pollution in fine particulate matter in Shanghai, China.

    PubMed

    Li, Xiaolin; Zhang, Yuanxun; Tan, Mingguang; Liu, Jiangfeng; Bao, Liangman; Zhang, Guilin; Li, Yan; Iida, Atsuo

    2009-01-01

    The Pb-monitoring program was extended for 6 years from 2002 to 2007 at 17 representative urban sites (6 traffic, 5 industrial, and 6 residential sites), and 3 suburban sites to assess the lead pollution in fine particulate matter (PM2.5) after phasing out leaded gasoline in Shanghai. Compared with Pb levels reported in other places, the Pb pollution in Shanghai is still serious after phasing out leaded gasoline, which remains at high concentration range (213-176 ng/m3) in PM2.5 in winter. Significant spatial variation of Pb concentrations and strong seasonal variation of higher Pb concentration in winter than that in summer were detected. The size distribution of Pb in particulate matter has a unimodal mode that peaks at approximately 0.154-1.59 microm particle diameter, indicating that Pb is mainly concentrated in fine fraction. Lead in the fine fraction is enriched by a factor of 10(3)-10(4) relative to Pb abundance in crust. Eight categories of Pb pollution sources were identified in the PM2.5 in the winter of 2007 in Shanghai. The important emission sources among them are vehicle exhaust derived from combustion of unleaded gasoline, metallurgic industry emission, and coal combustion emission. PMID:19862926

  2. Migration of contaminated soil and airborne particulates to indoor dust.

    PubMed

    Layton, David W; Beamer, Paloma I

    2009-11-01

    We have developed a modeling and measurement framework for assessing transport of contaminated soils and airborne particulates into a residence, their subsequent distribution indoors via resuspension and deposition processes, and removal by cleaning and building exhalation of suspended particles. The model explicitly accounts for the formation of house dust as a mixture of organic matter (OM) such as shed skin cells and organic fibers, soil tracked-in on footwear, and particulate matter (PM) derived from the infiltration of outdoor air. We derived formulas for use with measurements of inorganic contaminants, crustal tracers, OM, and PM to quantify selected transport parameters. Application of the model to residences in the U.S. Midwest indicates that As in ambient air can account for nearly 60% of the As input to floor dust, with soil track-in representing the remainder. Historic data on Pb contamination in Sacramento, CA, were used to reconstruct sources of Pb in indoor dust, showing that airborne Pb was likely the dominant source in the early 1980s. However, as airborne Pb levels declined due to the phase-out of leaded gasoline, soil resuspension and track-in eventually became the primary sources of Pb in house dust. PMID:19924944

  3. Particulated Juvenile Articular Cartilage Implantation in the Knee

    PubMed Central

    Stevens, Hazel Y.; Shockley, Blake E.; Willett, Nick J.; Lin, Angela S.P.; Raji, Yazdan; Labib, Sameh A.

    2014-01-01

    Objective: The goal of this report is to describe the outcome of sequential particulated cartilage allograft and autologous osteochondral transfer treatments for an osteochondral lesion of the medial femoral condyle. Methods: A 44-year-old woman was treated with a particulated juvenile articular cartilage allograft (DeNovo NT) for a chondral lesion of the knee. As a result of continued pain, she had 2 further surgeries, including an autologous osteochondral transfer system procedure and finally a unicondylar knee arthroplasty. At the final procedure, the areas of the allograft and autograft tissue were biopsied for histological evaluation. The quality of the residual cartilage tissue was assessed first by equilibrium partitioning of an ionic contrast agent via micro–computed tomography (EPIC-µCT), and then by hematoxylin and eosin, Safranin O staining, and polarized light microscopy. Results: Despite showing good healing at 7 months postsurgery by MRI, at 28 months post DeNovo NT tissue implantation the excised cartilage tissue was heterogeneous, with some regions of hyaline-like cartilage and some regions of fibrocartilage. The later mosaicplasty may have helped maintain hyaline-like cartilage of the DeNovo NT tissue in its vicinity. Conclusion: This case report describes the cartilage repair tissue produced by DeNovo NT implantation and compares it with autologous osteochondral plug tissue.

  4. Particulate matter analysis at elementary schools in Curitiba, Brazil.

    PubMed

    Avigo, Devanir; Godoi, Ana F L; Janissek, Paulo R; Makarovska, Yaroslava; Krata, Agnieszka; Potgieter-Vermaak, Sanja; Alfoldy, Balint; Van Grieken, René; Godoi, Ricardo H M

    2008-06-01

    The particulate matter indoors and outdoors of the classrooms at two schools in Curitiba, Brazil, was characterised in order to assess the indoor air quality. Information concerning the bulk composition was provided by energy-dispersive x-ray fluorescence (EDXRF). From the calculated indoor/outdoor ratios and the enrichment factors it was observed that S-, Cl- and Zn-rich particles are of concern in the indoor environment. In the present research, the chemical compositions of individual particles were quantitatively elucidated, including low-Z components like C, N and O, as well as higher-Z elements, using automated electron probe microanalysis low Z EPMA. Samples were further analysed for chemical and morphological aspects, determining the particle size distribution and classifying them according to elemental composition associations. Five classes were identified based on major elemental concentrations: aluminosilicate, soot, organic, calcium carbonate and iron-rich particles. The majority of the respirable particulate matter found inside of the classroom was composed of soot, biogenic and aluminosilicate particles. In view of the chemical composition and size distribution of the aerosol particles, local deposition efficiencies in the human respiratory system were calculated revealing the deposition of soot at alveolar level. The results showed that on average 42% of coarse particles are deposited at the extrathoracic level, whereas 24% are deposited at the pulmonary region. The fine fraction showed a deposition rate of approximately 18% for both deposition levels. PMID:18363047

  5. Airborne particulate soiling of terrestrial photovoltaic modules and cover materials

    NASA Technical Reports Server (NTRS)

    Hoffman, A. R.; Maag, C. R.

    1980-01-01

    Results are presented for the first phase of a photovoltaic-module soiling study that was carried out with NASA participation to investigate the problem of the electrical performance degradation of flat-plate photovoltaic modules exposed at outdoor sites that is due to the accumulation of airborne particulates on sensitive optical surfaces. The results were obtained in both field and laboratory soiling experiments, as well as in materials field experiments using candidate encapsulants and top covers. It is concluded that: (1) the electrical performance degradation shows a significant time and site dependence, ranging from 2% to 60% power loss; (2) the rate of particulate accumulation appears to be largely material independent when natural removal processes do not dominate; (3) the effectiveness of natural removal processes, especially rain, is strongly material dependent; (4) top-cover materials of glass and plexiglass retain fewer particles than silicone rubber; and (5) high module voltages relative to ground do not appear to affect the rate of dirt accumulation on modules.

  6. Shock driven jamming and periodic fracture of particulate rafts

    E-print Network

    M. M. Bandi; T. Tallinen; L. Mahadevan

    2011-09-24

    A tenuous monolayer of hydrophobic particles at the air-water interface often forms a scum or raft. When such a monolayer is disturbed by the localized introduction of a surfactant droplet, a radially divergent surfactant shock front emanates from the surfactant origin and packs the particles into a jammed, compact, annular band with a packing fraction that saturates at a peak packing fraction $\\phi^*$. As the resulting two-dimensional, disordered elastic band grows with time and is driven radially outwards by the surfactant, it fractures to form periodic triangular cracks with robust geometrical features. We find the number of cracks $N$ and the compaction band radius $R^*$ at fracture onset vary monotonically with the initial packing fraction ($\\phi_{init}$). However, its width $W^*$ is constant for all $\\phi_{init}$. A simple geometric theory that treats the compaction band as an elastic annulus, and accounts for mass conservation allows us to deduce that $N \\simeq 2\\pi R^*/W^* \\simeq 4\\pi \\phi_{RCP}/\\phi_{init}$, a result we verify both experimentally and numerically. We show the essential ingredients for this phenomenon are an initially low enough particulate packing fraction that allows surfactant driven advection to cause passive jamming and eventual fracture of the hydrophobic particulate interface.

  7. Chondral Defect Repair with Particulated Juvenile Cartilage Allograft

    PubMed Central

    Farr, Jack; Yao, Jian Q

    2011-01-01

    Objective: This case study of 4 patients followed for at least 2 years was conducted to evaluate a cartilage repair procedure that involves transplanting particulated juvenile allograft cartilage. Design: A multicenter, prospective, single-arm, 25-subject case study was designed to evaluate clinical outcomes such as IKDC and KOOS scores as well as the extent and quality of repair with MRI. In addition, there is an option for the transplants to be biopsied at various time points after implantation (up to 5 years). Currently, 25 patients with 1 or 2 chondral lesions on the femoral condyles and trochlea have been enrolled and treated in the prospective study. Results: The first 4 patients have completed an evaluation at 24 months postoperative follow-up. Improvements in clinical outcomes over the preoperative baseline data have been observed. Conclusions: The present report describes, for the first time, clinical intermediate-term results of a novel cartilage repair procedure that involves transplanting particulated juvenile cartilage tissue allograft into prepared cartilage lesions of the femoral condyles and/or trochlea. Clinical outcome data of 4 patients who have reached the 24-month postimplantation milestone indicate early positive outcomes and suggest that this technique is capable of improving clinical symptoms. MRI data suggest that defect filling is possible and persists to at least 2 years. Continued clinical evaluation of this technique is needed with extended follow-up of all 25 patients in the series.

  8. Migration of Contaminated Soil and Airborne Particulates to Indoor Dust

    PubMed Central

    Layton, David W.; Beamer, Paloma I.

    2009-01-01

    We have developed a modeling and measurement framework for assessing transport of contaminated soils and airborne particulates into a residence, their subsequent distribution indoors via resuspension and deposition processes, and removal by cleaning and building exhalation of suspended particles. The model explicitly accounts for the formation of house dust as a mixture of organic matter (OM) such as shed skin cells and organic fibers, soil tracked-in on footwear, and particulate matter (PM) derived from the infiltration of outdoor air. We derived formulas for use with measurements of inorganic contaminants, crustal tracers, OM, and PM to quantify selected transport parameters. Application of the model to residences in the U.S. Midwest indicates that As in ambient air can account for nearly 60% of the As input to floor dust, with soil track-in representing the remainder. Historic data on Pb contamination in Sacramento, CA, was used to reconstruct sources of Pb in indoor dust, showing that airborne Pb was likely the dominant source in the early 1980s. However, as airborne Pb levels declined due to the phase out of leaded gasoline, soil resuspension and track-in eventually became the primary sources of Pb in house dust. PMID:19924944

  9. [Structure, regulation and functions of particulate guanylyl cyclase type A].

    PubMed

    Mitkiewicz, Ma?gorzata

    2015-01-01

    Guanylyl cyclase type A (GC-A) belongs to the particulate guanylyl cyclases (pGC), which, like the soluble guanylyl cyclases (sGC), catalyze the synthesis of a common secondary messenger, namely cyclic GMP (cGMP), involved in many cellular processes. Although both forms of guanylyl cyclases produce the same secondary messenger, activation of each of them triggers different signaling pathways leading to different cellular effects. This indicates that the final effect of cGMP depends on the site of its synthesis in the cell (cytosol or cell membrane). Particulate guanylyl cyclase type A is a homodimeric protein activated by natriuretic peptides (ANP - atrial natriuretic peptide and BNP - brain natriuretic peptide) binding in the extracellular domain of the enzyme. The widespread expression of GC-A in different cell types and tissues suggests that this protein may regulate many cellular processes. Besides the role of GC-A in the cardiovascular system, which is the most thoroughly documented in the literature, it was observed that this protein is also involved in carcinogenesis and regulation of inflammatory reactions. This review describes important information about the structure, functions and regulation of GC-A catalytic activity, and the regulation of GC-A gene expression. PMID:25897107

  10. Personal coarse particulate matter exposures in an adult cohort

    NASA Astrophysics Data System (ADS)

    Williams, Ron; Case, Martin; Yeatts, Karin; Chen, Fu-Lin; Scott, James; Svendsen, Erik; Devlin, Robert

    Volunteers associated with the North Carolina Adult Asthma and Environment Study (NCAAES) participated in an investigation of personal daily exposures to coarse and fine particulate matter size fractions (PM 10-2.5, PM 2.5). Data from these personal measurements were then compared to community-based measures that might typically represent surrogate measurements of exposure often used in epidemiological assessments. To determine personal exposures to various particulate matter (PM) size fractions, a recently evaluated personal PM monitor capable of direct PM 10-2.5 size fraction collection was used. Participants living in the central region of North Carolina and enrolled in the NCAAES were asked to wear the monitor attached to a supporting backpack for 24-h collection periods. These volunteers were monitored for 2 to 4 days with subsequent gravimetric analysis of their PM samples. Personal PM 10-2.5 mass concentrations were observed to be highly variable and ranged from 7.6 to 40.2 ?g/m 3 over an 8-month period. The median for this measurement from all participants (50th percentile) was 13.7 ?g/m 3. A coefficient of determination ( r2) of 0.02 was established for community-based PM 10-2.5 mass concentrations versus personal exposures. Similar coefficients established for PM 2.5 mass revealed only a modest improvement in agreement ( r2 = 0.12). Data from the exposure findings are reported here.

  11. Characterization of Urban Runoff Pollution between Dissolved and Particulate Phases

    PubMed Central

    Wei, Zhang; Simin, Li; Fengbing, Tang

    2013-01-01

    To develop urban stormwater management effectively, characterization of urban runoff pollution between dissolved and particulate phases was studied by 12 rainfall events monitored for five typical urban catchments. The average event mean concentration (AEMC) of runoff pollutants in different phases was evaluated. The AEMC values of runoff pollutants in different phases from urban roads were higher than the ones from urban roofs. The proportions of total dissolved solids, total dissolved nitrogen, and total dissolved phosphorus in total ones for all the catchments were 26.19%–30.91%, 83.29%–90.51%, and 61.54–68.09%, respectively. During rainfall events, the pollutant concentration at the initial stage of rainfall was high and then sharply decreased to a low value. Affected by catchments characterization and rainfall distribution, the highest concentration of road pollutants might appear in the later period of rainfall. Strong correlations were also found among runoffs pollutants in different phases. Total suspended solid could be considered as a surrogate for particulate matters in both road and roof runoff, while dissolved chemical oxygen demand could be regarded as a surrogate for dissolved matters in roof runoff. PMID:23935444

  12. Characterization of urban runoff pollution between dissolved and particulate phases.

    PubMed

    Wei, Zhang; Simin, Li; Fengbing, Tang

    2013-01-01

    To develop urban stormwater management effectively, characterization of urban runoff pollution between dissolved and particulate phases was studied by 12 rainfall events monitored for five typical urban catchments. The average event mean concentration (AEMC) of runoff pollutants in different phases was evaluated. The AEMC values of runoff pollutants in different phases from urban roads were higher than the ones from urban roofs. The proportions of total dissolved solids, total dissolved nitrogen, and total dissolved phosphorus in total ones for all the catchments were 26.19%-30.91%, 83.29%-90.51%, and 61.54-68.09%, respectively. During rainfall events, the pollutant concentration at the initial stage of rainfall was high and then sharply decreased to a low value. Affected by catchments characterization and rainfall distribution, the highest concentration of road pollutants might appear in the later period of rainfall. Strong correlations were also found among runoffs pollutants in different phases. Total suspended solid could be considered as a surrogate for particulate matters in both road and roof runoff, while dissolved chemical oxygen demand could be regarded as a surrogate for dissolved matters in roof runoff. PMID:23935444

  13. Characterizing Aerosolized Particulate As Part Of A Nanoprocess Exposure Assessment

    SciTech Connect

    Jankovic, John Timothy [ORNL; Ogle, Burton R [ORNL; Zontek, Tracy L [ORNL; Hollenbeck, Scott M [ORNL

    2010-01-01

    The purpose of this effort was to propose important aerosol characterization parameters that should be gathered as part of a nanomaterial hazard assessment and to offer a methodology for applying that data to daily operations. This study documents different ways of characterizing nanoscale materials using an aerosol from a process simulation consisting of a vacuum cleaner motor operating inside an enclosure. The aerosol is composed of insoluble carbon particles plus environmental background constituents. The average air concentration is 2.76E+5 p/cm3. Size measurements of the aerosol indicate > 70% of the particulate is blade-like in shape, 50% of which have a height dimension 100 nm. In terms of an equivalent spherical diameter 0.8% of the particulate is 100 nm in size. The carbon blades are characterized as having a root-mean-square roughness of 75 nm, and average fractal dimension of 2.25. These measures: aerosol chemistry, solubility, shape and size, surface area, number concentration and size distribution are important parameters to collect for current exposure assessment and toxicology and epidemiology studies.

  14. Cooler and particulate separator for an off-gas stack

    DOEpatents

    Wright, George T. (15 Cherry Hills Dr., Aiken, SC 29803)

    1992-01-01

    An off-gas stack for a melter comprising an air conduit leading to two sets of holes, one set injecting air into the off-gas stack near the melter plenum and the second set injecting air downstream of the first set. The first set injects air at a compound angle, having both downward and tangential components, to create a reverse vortex flow, counter to the direction of flow of gas through the stack and also along the periphery of the stack interior surface. Air from the first set of holes pervents recirculation zones from forming and the attendant accumulation of particulate deposits on the wall of the stack and will also return to the plenum any particulate swept up in the gas entering the stack. The second set of holes injects air in the same direction as the gas in the stack to compensate for the pressure drop and to prevent the concentration of condensate in the stack. A set of sprayers, receiving water from a second conduit, is located downstream of the second set of holes and sprays water into the gas to further cool it.

  15. Role of livestock effluent suspended particulate in sealing effluent ponds.

    PubMed

    Bennett, J McL; Warren, B R

    2015-05-01

    Intensive livestock feed-lots have become more prevalent in recent years to help in meeting the predicted food production targets based on expected population growth. Effluent from these is stored in ponds, representing a potential concern for seepage and contamination of groundwater. Whilst previous literature suggests that effluent particulate can limit seepage adequately in combination with a clay liner, this research addresses potential concerns for sealing of ponds with low concentration fine and then evaluates this against proposed filter-cake based methodologies to describe and predict hydraulic reduction. Short soil cores were compacted to 98% of the maximum dry density and subject to ponded head percolation with unfiltered-sediment-reduced effluent, effluent filtered to <3 ?m, and chemically synthesized effluent. Reduction in hydraulic conductivity was observed to be primarily due to the colloidal fraction of the effluent, with larger particulate fractions providing minimal further reduction. Pond sealing was shown to follow mathematical models of filter-cake formation, but without the formation of a physical seal on top of the soil surface. Management considerations based on the results are presented. PMID:25721977

  16. Particulate matter, gaseous and particulate polycyclic aromatic hydrocarbons (PAHs) in an urban traffic tunnel of China: Emission from on-road vehicles and gas-particle partitioning.

    PubMed

    Liu, Ying; Gao, Yi; Yu, Na; Zhang, Chenkai; Wang, Siyao; Ma, Limin; Zhao, Jianfu; Lohmann, Rainer

    2015-09-01

    Traffic vehicles are a main source of polycyclic aromatic hydrocarbon (PAH) emission in urban area. It is vital to understand PAH gas-particle partitioning in real traffic environment and assess PAH vehicular emission factors in developing China. Concentrations of particulate matter, carbonaceous products, gaseous and particulate PAHs were measured during 2011-2012 in a road tunnel of Shanghai, China. Time variation of them reflected basic traffic operation of the tunnel. PAHs approached equilibrium between gas and particle phases and the partitioning was predicted better by a dual sorption model combining absorption into organic matter and adsorption onto black carbon. The influence of black carbon adsorption on the partitioning behavior of PAHs was important. The difference in isomer ratios of gaseous and particulate PAHs was attributed to PAH contributions from different traffic-related PAHs sources. Real-world vehicle emission factors of gaseous and particulate PAHs were quantified based on fuel burned model and vehicle kilometer traveled model. PMID:25911047

  17. Spectral absorption properties of dissolved and particulate matter in Lake Erie

    Microsoft Academic Search

    Caren E. Binding; John H. Jerome; Robert P. Bukata; William G. Booty

    2008-01-01

    Spectral absorption properties of particulate and dissolved matter were determined for Lake Erie waters in order to investigate the natural variability of the absorption coefficients required as inputs to optical models for converting satellite observations of water colour into water quality information. Particulate absorption measured using the quantitative filter technique yielded absorption spectra containing a fraction that could not be

  18. Particle size distribution characteristics of cotton gin overflow system total particulate emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report is part of a project to characterize cotton gin emissions from the standpoint of total particulate stack sampling and particle size analyses. In 2013, EPA published a more stringent standard for particulate matter with nominal diameter less than or equal to 2.5 µm (PM2.5). This created a...

  19. EFFECT OF PARTICULATES ON OZONE DISINFECTION OF BACTERIA AND VIRUSES IN WATER

    EPA Science Inventory

    The research was initiated in order to determine the effect of particulates on ozone disinfection of enteric bacteria and viruses adsorbed to or incorporated into particulate materials such as fecal material, HEp-2 cells, aluminum oxide floc and bentonite clay. Microorganisms use...

  20. Indoor/outdoor relationship of trace metals in the atmospheric particulate matter of an industrial area

    NASA Astrophysics Data System (ADS)

    Nazir, Rashida; Shaheen, Nazia; Shah, Munir H.

    2011-08-01

    Present study is based on the measurement and monitoring of indoor and outdoor atmospheric particulate matter from an industrial area (Wah Cantt, Pakistan). The particulate samples are collected on glass fiber filter paper using high volume air sampler. Trace metals (Cd, Co, Cr, Cu, Fe, Mn, Pb, Sb and Zn) in the particulate samples are estimated by atomic absorption spectrometry. On the average TSP level is significantly higher in outdoor atmosphere than indoor, and both of them are higher than WHO and USEPA standards. The distribution of trace metals is considerably diverse in indoor and outdoor particulates. Average concentrations of Fe, Zn, Co, Cr and Mn are significantly higher in outdoor particulates, whereas Cu and Pb levels are considerably higher in the indoor particulates. Source apportionment carried out by PCA and CA is diverse in indoor/outdoor particulates and the major pollution sources identified are industrial activities, automobile emissions and soil derived dust. Among the trace metals, Cd, Sb, Zn, Pb and Co are found to be highly enriched in the atmospheric particulate matter. The present atmospheric trace metals levels are also compared with those reported from other regions around the world, and are many-folds higher than previously reported results.

  1. Next Generation Non-particulate Dry Nonwoven Pad for Chemical Warfare Agent Decontamination

    Microsoft Academic Search

    S S Ramkumar; A Love; U R Sata; C J Koester; W J Smith; G A Keating; L Hobbs; S B Cox; W M Lagna; R J Kendall

    2008-01-01

    New, non-particulate decontamination materials promise to reduce both military and civilian casualties by enabling individuals to decontaminate themselves and their equipment within minutes of exposure to chemical warfare agents or other toxic materials. One of the most promising new materials has been developed using a needlepunching nonwoven process to construct a novel and non-particulate composite fabric of multiple layers, including

  2. Characterization of volatile organic compounds and odorants associated with swine barn particulate matter

    Microsoft Academic Search

    Jacek A. Koziel; Lingshuang Cai; Yin-Cheung Lo; Steven J. Hoff

    Swine operations can affect air quality by emissions of odor, volatile organic compounds (VOCs) and other gases, and particulate matter (PM). Particulate matter has been proposed to be an important pathway for carrying odor. However, little is known about the odor-VOCs-PM interactions. In this research, continuous PM sampling was conducted simultaneously with three collocated TEOM analyzers inside a 1000-head swine

  3. Distributions and variability of particulate organic matter in a coastal upwelling system

    E-print Network

    Pierce, Stephen

    Distributions and variability of particulate organic matter in a coastal upwelling system L. Karp (2004), Distributions and variability of particulate organic matter in a coastal upwelling system, J of information on POM in such systems. Basic questions such as, how is POM distributed across the shelf, what

  4. INHALABLE PARTICULATE NETWORK REPORT: DATA SUMMARY (MASS CONCENTRATIONS ONLY). VOLUME 3. JANUARY 1983-DECEMBER 1984

    EPA Science Inventory

    The report is the third in a series of Inhalable Particulate (IP) Network reports covering 157 sites within the United States. PM10 (10 micron) size particulate mass data and data summaries for 88 active sampling sites are emphasized. Field operations and Quality Assurance proced...

  5. AGE-DEPENDENT CHANGES IN GASTROINTESTINAL TRANSPORT AND RETENTION OF PARTICULATE MANGANESE OXIDE IN THE RAT

    EPA Science Inventory

    Translocation of inhaled particulates from the nasopharynx and upper tracheobronchial area to the gastrointestinal tract is a major route of exposure for particles with a mass median diameter of greater than 1 micro m. Previous studies in this laboratory with particulate Mn3O4 ha...

  6. Empirical ocean color algorithms for estimating particulate organic carbon in the Southern Ocean

    E-print Network

    Stramski, Dariusz

    Empirical ocean color algorithms for estimating particulate organic carbon in the Southern Ocean for estimating surface concentration of particulate organic carbon (POC) from remotely sensed ocean color in the Southern Ocean using field data of POC, spectral remotesensing reflectance, Rrs(l), and the inherent

  7. CHEMICAL AND TOXICOLOGICAL CHARACTERIZATION OF AIRBORNE TOTAL SUSPENDED PARTICULATE (TSP) AND PM10 ORGANIC EXTRACTS

    Microsoft Academic Search

    Roberto Fabiani; Angelo De Bartolomeo; Patrizia Rosignoli; Guido Morozzi; Angelo Cecinato; Catia Balducci

    2008-01-01

    The relationship between chemical composition of airborne particulates and the genotoxicity has been investigated in the atmosphere of Rome, Italy. For this purpose, both total suspended particulate (TSP) and the PM10 fractions were collected daily inside a green park located in downtown, grouped on a weekly basis and speciated for their burdens of polycyclic aromatic hydrocarbons (PAH) and nitro-PAH. Concurrently,

  8. MEASUREMENTS OF POLYCYCLIC AROMATIC HYDROCARBONS IN AMBIENT AIR PARTICULATES IN NORTHERN NEW ENGLAND

    EPA Science Inventory

    The paper gives results of measuring polycyclic aromatic hydrocarbons (PAHs) in ambient air particulates in Northern New England. Standard high-volume filter samples of ambient-air particulates were collected during several heating seasons in a semi-rural village, a rural area, a...

  9. Particle size distribution characteristics of cotton gin first stage lint cleaning system total particulate emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report is part of a project to characterize cotton gin emissions from the standpoint of total particulate stack sampling and particle size analyses. In 2006, EPA published a more stringent standard for particulate matter with nominal diameter less than or equal to 2.5 µm (PM2.5). This created a...

  10. Update on the development of particulate matter emission factors for cotton harvesting

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accurate particulate matter emission factor data from modern cotton harvesting operations is not available for regulatory use. Thus, the objective of this work was to develop accurate dust emission factors for modern cotton harvesting operations in terms of PM10, PM2.5, and TSP. Particulate matter s...

  11. Particle size distribution characteristics of cotton gin combined lint cleaning system total particulate emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report is part of a project to characterize cotton gin emissions from the standpoint of total particulate stack sampling and particle size analyses. In 2013, EPA published a more stringent standard for particulate matter with nominal diameter less than or equal to 2.5 µm (PM2.5). This created a...

  12. Particle size distribution characteristics of cotton gin master trash system total particulate emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report is part of a project to characterize cotton gin emissions from the standpoint of total particulate stack sampling and particle size analyses. In 2013, EPA published a more stringent standard for particulate matter with nominal diameter less than or equal to 2.5 µm (PM2.5). This created a...

  13. Particle size distribution characteristics of cotton gin second stage lint cleaning system total particulate emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report is part of a project to characterize cotton gin emissions from the standpoint of total particulate stack sampling and particle size analyses. In 2013, EPA published a more stringent standard for particulate matter with nominal diameter less than or equal to 2.5 µm (PM2.5). This created a...

  14. Particle size distribution characteristics of cotton gin cyclone robber system total particulate emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report is part of a project to characterize cotton gin emissions from the standpoint of total particulate stack sampling and particle size analyses. In 2013, EPA published a more stringent standard for particulate matter with nominal diameter less than or equal to 2.5 µm (PM2.5). This created a...

  15. Particle size distribution characteristics of cotton gin first stage mote system total particulate emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report is part of a project to characterize cotton gin emissions from the standpoint of total particulate stack sampling and particle size analyses. In 2013, EPA published a more stringent standard for particulate matter with nominal diameter less than or equal to 2.5 µm (PM2.5). This created a...

  16. Particle size distribution characteristics of cotton gin mote cleaner system total particulate emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report is part of a project to characterize cotton gin emissions from the standpoint of total particulate stack sampling and particle size analyses. In 2013, EPA published a more stringent standard for particulate matter with nominal diameter less than or equal to 2.5 µm (PM2.5). This created a...

  17. Fine-Particulate Air Pollution and Life Expectancy in the United States

    Microsoft Academic Search

    C. Arden Pope III; Majid Ezzati; Douglas W. Dockery

    2010-01-01

    Background Exposure to fine-particulate air pollution has been associated with increased mor- bidity and mortality, suggesting that sustained reductions in pollution exposure should result in improved life expectancy. This study directly evaluated the changes in life expectancy associated with differential changes in fine particulate air pollu- tion that occurred in the United States during the 1980s and 1990s. Methods We

  18. Thermal conductivity of particulate materials: A summary of measurements taken at the Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    Fountain, J. A.

    1973-01-01

    Thermal conductivity measurements of particulate materials in vacuum are presented in summary. Particulate basalt and soda lime glass beads of various size ranges were used as samples. The differentiated line heat source method was used for the measurements. A comprehensive table is shown giving all pertinent experimental conditions. Least-squares curve fits to the data are presented.

  19. Particle size distribution characteristics of cotton gin unloading system total particulate emissions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report is part of a project to characterize cotton gin emissions from the standpoint of total particulate stack sampling and particle size analyses. In 2013, EPA published a more stringent standard for particulate matter with nominal diameter less than or equal to 2.5 µm (PM2.5). This created a...

  20. PROCEEDINGS: SEVENTH SYMPOSIUM ON THE TRANSFER AND UTILIZATION OF PARTICULATE CONTROL TECHNOLOGY. VOLUME 2

    EPA Science Inventory

    The proceedings document presentations from the seventh symposium on the transfer and utilization of particulate control technology, March 22-25, 1988, in Nashville, TN. Objectives of the symposium were to encourage the exchange of new knowledge in the particulate control field b...

  1. SOURCE SAMPLING OF PARTICULATE MATTER EMISSIONS FROM COTTON HARVESTING - SYSTEM DESIGN AND EVALUATION

    Microsoft Academic Search

    J. D. Wanjura; C. B. Parnell; B. W. Shaw; S. C. Capareda; R. E. Lacey

    State and regional air pollution regulatory agencies are required by federal law to reduce ambient particulate matter concentrations in non-attainment areas to a level in compliance with National Ambient Air Quality Standards. All emission regulations, including reduction regulations, should be based on accurate emission factors. Agricultural particulate matter emission factors are difficult to quantify due to the nature of the

  2. Aqueous processing of natural graphite particulates for lithium-ion battery anodes and their electrochemical performance

    Microsoft Academic Search

    Jin-Hyon Lee; Sangkyu Lee; Ungyu Paik; Young-Min Choi

    2005-01-01

    Aqueous-based natural graphite particulates for fabrication of lithium-ion battery anodes are investigated with emphasis on chemical control of suspension component interactions among graphite particulates, sodium carboxymethyl cellulose (CMC), and emulsified styrene butadiene rubber (SBR). The chemical stability and dispersion properties of the natural graphite particles are characterized using electroacoustic, flow behaviour and green microstructural observations, as well as by measurement

  3. A Literature Review of Concentrations and Size Distributions of Ambient Airborne Pb-Containing Particulate Matter

    EPA Science Inventory

    The final 2008 lead (Pb) national ambient air quality standards (NAAQS) revision maintains Pb in total suspended particulate matter as the indicator. However, the final rule permits the use of low-volume PM10 (particulate matter sampled with a 50% cut-point of 10 µm) F...

  4. Incorporation of particulates into accreted ice above subglacial Vostok lake, Antarctica

    E-print Network

    Christner, Brent C.

    Incorporation of particulates into accreted ice above subglacial Vostok lake, Antarctica George of microscopic particulates in meteoric and accreted ice from the Vostok (Antarctica) ice core is assessed depth in the southern part of the lake at Vostok station by the Russian Antarctic Expedition. The top

  5. Sensitivity of Diesel Particulate Material Emissions and Composition to Blends of Petroleum Diesel and Biodiesel Fuel

    Microsoft Academic Search

    Kento T. Magara-Gomez; Michael R. Olson; Tomoaki Okuda; Kenneth A. Walz; James J. Schauer

    2012-01-01

    A number of investigations have examined the impact of the use of biodiesel on the emissions of carbon dioxide and regulated emissions but limited information exists on the chemical composition of particulate matter from diesel engines burning biodiesel blends. This study examines the composition of diesel particulate matter (DPM) emissions from a commercial agriculture tractor burning a range of biodiesel

  6. Relationship between Radical Generation by Urban Ambient Particulate Matter and Pulmonary Function of School Children

    Microsoft Academic Search

    Janneke G. F. Hogervorst; Theo M. C. M. de Kok; Jacob J. Briedé; Geertjan Wesseling; Jos C. S. Kleinjans; Constant P. van Schayck

    2006-01-01

    The mechanisms by which particulate matter (PM) produces adverse effects on the respiratory system, such as pulmonary dysfunction in children, are largely unknown. However, oxidative stress is thought to play an important role. Various chemical compounds in ambient particulate matter, including transition metals and aromatic organic compounds, may contribute to adverse effects through intrinsic generation of reactive oxygen species (ROS).

  7. Ambient particulate matter accelerates coagulation via an IL-6-dependent pathway

    EPA Science Inventory

    The mechanisms by which exposure to particulate matter increases the risk of cardiovascular events are not known. Recent human and animal data suggest that particulate matter may induce alterations in hemostatic factors. In this study we determined the mechanisms by which particu...

  8. Simultaneous control of particulate and NO x emissions from diesel engines

    Microsoft Academic Search

    Jerry C. Summers; Stéphane Van Houtte; Dimitrios Psaras

    1996-01-01

    In view of increased concerns regarding the effects of diesel engine particulate and NOx emissions on human health and the environment, legislators are currently reviewing and proposing legislation targeting the reduction of these pollutants. The reported serious health risks of particulate matter on the respiratory system and its carcinogenic effects, along with the known contributions of NOx in acid rain

  9. QUANTITATION, DETECTION AND MEASUREMENT PRECISION OF ORGANIC MOLECULAR MARKERS IN URBAN PARTICULATE MATTER FROM PHILADELPHIA, PA

    EPA Science Inventory

    This work focuses on analysis of organic molecular markers in airborne particulate matter (PM) by Gas Chromatography/Ion Trap Mass Spectrometry (GC/IT MS). The particulate samples used in the method development were collected as PM10 in metropolitan Philadelphia during...

  10. DEVELOPMENT OF A SAMPLER FOR PARTICULATE-ASSOCIATED AND LOW VOLATILITY ORGANIC POLLUTANTS IN RESIDENTIAL AIR

    EPA Science Inventory

    The report describes the development of a sampler for particulate-associated and low volatility organic pollutants in residential air. The performance of the sampler inlet, which is compatible with the proposed PM-10 regulations for particulate sampling, is documented under a var...

  11. Interpretation of particulate elemental and organic carbon concentrations at rural, urban and kerbside sites

    Microsoft Academic Search

    Alan M. Jones; Roy M. Harrison

    2005-01-01

    Concentration measurements are reported for particulate organic and elemental carbon, measured using an R&P 5400 ambient particulate carbon monitor at four sites in the United Kingdom: one roadside (London, Marylebone Road), two urban (London, North Kensington, and Belfast, Centre) and one rural (Harwell). The measurements were collected on a continuous three hourly average basis between January 2002 and mid-2004. The

  12. Mercury adsorption to elemental carbon (soot) particles and atmospheric particulate matter

    Microsoft Academic Search

    Christian Seigneur; Heike Abeck; Gary Chia; Martin Reinhard; Nicolas S. Bloom; Eric Prestbo; Pradeep Saxena

    1998-01-01

    An assessment of the adsorption\\/desorption of mercury onto\\/from particulate matter is presented. This assessment addresses both elemental carbon (soot) particles using published data and atmospheric particulate matter using new experimental data. Available experimental data on the adsorption of mercury onto elemental carbon particles have been reexamined in terms of their adsorption isotherms. The experimental data sets analyzed include experiments concerning

  13. EXPOSURE ASSESSMENT FROM THE NERL RESEARCH TRIANGLE PARK PARTICULATE MATTER PANEL STUDY

    EPA Science Inventory

    The U.S. Environmental Protection Agency performed a particulate matter (PM) exposure assessment based on data from the National Exposure Research Laboratory (NERL) Research Triangle Park (RTP) Particulate Matter (PM) Panel Study. This study was a one-year investigation of PM ...

  14. Noise Pollution and How it Can Indirectly Affect the Amounts of Particulate Matter in the Environment

    Microsoft Academic Search

    S. Swamy; J. Power; D. Pham; K. B. Preston; A. Iqbal

    2007-01-01

    Human and animal activity that occurs on gravel and dirt roads tends to contribute to high levels of particulate matter in the atmosphere. Birds molt their feathers, automobiles emit unused residues, and humans and animals stir up debris on the ground. Not only do these activities generate particulate matter, but they also generate noise. The aim of our study was

  15. Systematic Evaluation of Dissolved Lead Sorption Losses to Particulate Syringe Filter Materials

    EPA Science Inventory

    Distinguishing between soluble and particulate lead in drinking water is useful in understanding the mechanism of lead release and identifying remedial action. Typically, particulate lead is defined as the amount of lead removed by a 0.45 µm filter. Unfortunately, there is ...

  16. Deposition, resuspension, and decomposition of particulate organic matter in the sediments of Lake Itasca, Minnesota, USA

    Microsoft Academic Search

    Randall E. Hicks; Christopher J. Owen; Peter Aas

    1994-01-01

    Sediment traps were used to investigate the settling, resuspension, and decomposition of particulate organic matter in Lake Itasca, MN (USA). Traps were deployed in the epilimnion and hypolimnion of the deepest basin during June, 1988, sampled twice during stratified conditions (August, September) and once after the lake had mixed (October). The downward flux of particulate material increased from summer to

  17. LIME AND CEMENT INDUSTRY PARTICULATE EMISSIONS: SOURCE CATEGORY REPORT. VOLUME 2. CEMENT INDUSTRY

    EPA Science Inventory

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

  18. LIME AND CEMENT INDUSTRY PARTICULATE EMISSIONS: SOURCE CATEGORY REPORT. VOLUME 1. LIME INDUSTRY

    EPA Science Inventory

    The report gives results of a study to develop particulate emission factors based on cutoff size for inhalable particles for the lime industry. After reviewing available information characterizing particulate emissions from lime plants, the data were summarized and rated in terms...

  19. APPLICATION OF AIR DISPERSION MODELLING FOR EXPOSURE ASSESSMENT FROM PARTICULATE MATTER POLLUTION IN MEGA CITY DELHI

    Microsoft Academic Search

    Shweta Bhati; Manju Mohan; Archana Rao

    An attempt has been made to apply air dispersion modeling for exposure assessment of particulate matter in terms of mortality change. Ambient particulate matter concentrations have been estimated by AERMOD (07026) for the year 2004 in Delhi, India. Concentration output has been obtained for all sources as well as individual source category. It has been found that though the model

  20. The Effects of Computer Animation on the Particulate Mental Models of College Chemistry Students.

    ERIC Educational Resources Information Center

    Williamson, Vickie M.; Abraham, Michael R.

    1995-01-01

    A Particulate Nature of Matter Evaluation Tests was used to explore the effect of computer animations depicting the particulate nature of matter on (n=400) college students' mental models and comprehension of chemical phenomena. Treatment groups received significantly higher conceptual understanding scores than did the control group. (30…