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1

Ecto-nucleotidases of the CD39\\/NTPDase family modulate platelet activation and thrombus formation: Potential as therapeutic targets  

Microsoft Academic Search

Extracellular nucleotide P2-receptor-mediated effects on platelets, leukocytes and endothelium are modulated by ecto-nucleotidases. These ecto-enzymes hydrolyze extracellular nucleotides to the respective nucleosides. The dominant ecto-nucleotidase expressed by the endothelium, by monocytes and vascular smooth muscle cells is CD39\\/NTPDase1. Ecto-nucleotidase biochemical activity of CD39 is lost at sites of acute vascular injury, such as in ischemia reperfusion and immune graft rejection.

Ben Atkinson; Karen Dwyer; Keiichi Enjyoji; Simon C. Robson

2006-01-01

2

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

PubMed Central

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

Aliagas, Elisabet; Vidal, August; Texido, Laura; Ponce, Jordi; Condom, Enric; Martin-Satue, Mireia

2014-01-01

3

Antiepileptic Drugs Prevent Changes Induced by Pilocarpine Model of Epilepsy in Brain Ecto-Nucleotidases  

Microsoft Academic Search

Ecto-nucleotidases, one of the main mechanisms involved in the control of adenosine levels in the synaptic cleft, have shown\\u000a increased activities after the pilocarpine model of epilepsy. Here we have investigated the effect of the antiepileptic drugs\\u000a (AEDs) on ecto-nucleotidase activities from hippocampal and cerebral cortical synaptosomes of rats at seven days after the\\u000a induction of the pilocarpine model. Expression

Giana de Paula Cognato; Alessandra Nejar Bruno; Rosane Souza da Silva; Maurício Reis Bogo; João José Freitas Sarkis; Carla Denise Bonan

2007-01-01

4

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

PubMed Central

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.

Texido, Laura; Romero, Claudia; Garcia-Valero, Jose; Fernandez Montoli, M. Eulalia; Baixeras, Nuria; Condom, Enric; Ponce, Jordi; Garcia-Tejedor, Amparo; Martin-Satue, Mireia

2014-01-01

5

Reduced striatal ecto-nucleotidase activity in schizophrenia patients supports the "adenosine hypothesis".  

PubMed

Schizophrenia (SZ) is a major chronic neuropsychiatric disorder characterized by a hyperdopaminergic state. The hypoadenosinergic hypothesis proposes that reduced extracellular adenosine levels contribute to dopamine D2 receptor hyperactivity. ATP, through the action of ecto-nucleotidases, constitutes a main source of extracellular adenosine. In the present study, we examined the activity of ecto-nucleotidases (NTPDases, ecto-5'-nucleotidase, and alkaline phosphatase) in the postmortem putamen of SZ patients (n?=?13) compared with aged-matched controls (n?=?10). We firstly demonstrated, by means of artificial postmortem delay experiments, that ecto-nucleotidase activity in human brains was stable up to 24 h, indicating the reliability of this tissue for these enzyme determinations. Remarkably, NTPDase-attributable activity (both ATPase and ADPase) was found to be reduced in SZ patients, while ecto-5'-nucleotidase and alkaline phosphatase activity remained unchanged. In the present study, we also describe the localization of these ecto-enzymes in human putamen control samples, showing differential expression in blood vessels, neurons, and glial cells. In conclusion, reduced striatal NTPDase activity may contribute to the pathophysiology of SZ, and it represents a potential mechanism of adenosine signalling impairment in this illness. PMID:23771238

Aliagas, Elisabet; Villar-Menéndez, Izaskun; Sévigny, Jean; Roca, Mercedes; Romeu, Miriam; Ferrer, Isidre; Martín-Satué, Mireia; Barrachina, Marta

2013-12-01

6

Exercise training prevents ecto-nucleotidases alterations in platelets of hypertensive rats.  

PubMed

In this study, we investigated the effect of 6 weeks of swimming training on the ecto-nucleotidase activities and platelet aggregation from rats that developed hypertension in response to oral administration of L-NAME. The rats were divided into four groups: control (n = 10), exercise (n = 10), L-NAME (n = 10), and exercise L-NAME (n = 10). The animals were trained five times per week in an adapted swimming system for 60 min with a gradual increase of the workload up to 5 % of animal's body weight. The results showed an increase in ATP, ADP, AMP, and adenosine hydrolysis, indicating an augment in NTPDase (from 35.3 ± 8.1 to 53.0 ± 15.1 nmol Pi/min/mg protein for ATP; and from 21.7 ± 7.0 to 46.4 ± 15.6 nmol Pi/min/mg protein for ADP as substrate), ecto-5'-nucleotidase (from 8.0 ± 5.7 to 28.1 ± 6.9 nmol Pi/min/mg protein), and ADA (from 0.8 ± 0.5 to 3.9 ± 0.8 U/L) activities in platelets from L-NAME-treated rats when compared to other groups (p < 0.05). A significant augment on platelet aggregation in L-NAME group was also observed. Exercise training was efficient in preventing these alterations in the exercise L-NAME group, besides showing a significant hypotensive effect. In conclusion, our results clearly indicated a protector action of moderate intensity exercise on nucleotides and nucleoside hydrolysis and on platelet aggregation, which highlights the exercise training effect to avoid hypertension complications related to ecto-nucleotidase activities. PMID:22915168

Cardoso, Andréia Machado; Bagatini, Margarete Dulce; Martins, Caroline Curry; Abdalla, Fátima Hussein; Zanini, Daniela; Schmatz, Roberta; Gutierres, Jessié; Pimentel, Victor Camera; Thomé, Gustavo; Leal, Claudio Alberto Martins; Vieira, Juliano Marchi; Stefanello, Naiara; da Silva Fiorin, Fernando; Baldissareli, Jucimara; Royes, Luiz Fernando Freire; Klein, Adriane Bello; Morsch, Vera Maria; Schetinger, Maria Rosa Chitolina

2012-12-01

7

CD39\\/NTPDase-1 activity and expression in normal leukocytes  

Microsoft Academic Search

IntroductionCD39\\/NTPDase-1 is a cell surface enzyme expressed on leukocytes and endothelial cells that metabolizes ATP to ADP and AMP. CD39 is expressed on numerous different types of normal leukocytes, but details of its expression have not been determined previously.

E. Dianne Pulte; M. Johan Broekman; Kim E. Olson; Joan H. F. Drosopoulos; Jorge R. Kizer; Naziba Islam; Aaron J. Marcus

2007-01-01

8

CD39/Adenosine Pathway Is Involved in AIDS Progression  

E-print Network

CD39/Adenosine Pathway Is Involved in AIDS Progression Maria Nikolova1,2. , Matthieu Carriere139/ENTPD1, an ectoenzyme which in concert with CD73 generates adenosine. We show in vitro that the CD39/adenosine axis is involved in Treg suppression in HIV infection. Treg inhibitory effects

Paris-Sud XI, Université de

9

The GDA1_CD39 superfamily: NTPDases with diverse functions  

Microsoft Academic Search

The first comprehensive review of the ubiquitous “ecto-ATPases” by Plesner was published in 1995. A year later, a lymphoid\\u000a cell activation antigen, CD39, that had been cloned previously, was shown to be an ecto-ATPase. A family of proteins, related\\u000a to CD39 and a yeast GDPase, all containing the canonical apyrase conserved regions in their polypeptides, soon started to\\u000a expand. They

Aileen F. Knowles

2011-01-01

10

CD39 and CD73 in immunity and inflammation  

PubMed Central

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

Antonioli, Luca; Pacher, Pal; Vizi, E. Sylvester; Hasko, Gyorgy

2013-01-01

11

The GDA1_CD39 superfamily: NTPDases with diverse functions.  

PubMed

The first comprehensive review of the ubiquitous "ecto-ATPases" by Plesner was published in 1995. A year later, a lymphoid cell activation antigen, CD39, that had been cloned previously, was shown to be an ecto-ATPase. A family of proteins, related to CD39 and a yeast GDPase, all containing the canonical apyrase conserved regions in their polypeptides, soon started to expand. They are now recognized as members of the GDA1_CD39 protein family. Because proteins in this family hydrolyze nucleoside triphosphates and diphosphates, a unifying nomenclature, nucleoside triphosphate diphopshohydrolases (NTPDases), was established in 2000. Membrane-bound NTPDases are either located on the cell surface or membranes of intracellular organelles. Soluble NTPDases exist in the cytosol and may be secreted. In the last 15 years, molecular cloning and functional expression have facilitated biochemical characterization of NTPDases of many organisms, culminating in the recent structural determination of the ecto-domain of a mammalian cell surface NTPDase and a bacterial NTPDase. The first goal of this review is to summarize the biochemical, mutagenesis, and structural studies of the NTPDases. Because of their ability in hydrolyzing extracellular nucleotides, the mammalian cell surface NTPDases (the ecto-NTPDases) which regulate purinergic signaling have received the most attention. Less appreciated are the functions of intracellular NTPDases and NTPDases of other organisms, e.g., bacteria, parasites, Drosophila, plants, etc. The second goal of this review is to summarize recent findings which demonstrate the involvement of the NTPDases in multiple and diverse physiological processes: pathogen-host interaction, plant growth, eukaryote cell protein and lipid glycosylation, eye development, and oncogenesis. PMID:21484095

Knowles, Aileen F

2011-03-01

12

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

Microsoft Academic Search

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

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

2001-01-01

13

Heightened NTPDase-1\\/CD39 expression and angiogenesis in radiation proctitis  

Microsoft Academic Search

Radiation proctitis is an inflammatory process associated with persistent and refractory lower gastrointestinal bleeding.\\u000a Purinergic signaling regulates hemostasis, inflammation, and angiogenesis. For example, CD39, the vascular ectonucleotidase,\\u000a blocks platelet activation and is required for angiogenesis. Whether CD39 expression is affected by radiation injury is unknown.\\u000a The aim of this work was to study CD39 expression patterns after clinical radiation injury

Sunil Sheth; Wissam Bleibel; Chandrashekhar Thukral; Yousif A-Rahim; Guido Beldi; Eva Csizmadia; Simon C. Robson

2009-01-01

14

Elucidation of the thromboregulatory role of CD39/ectoapyrase in the ischemic brain  

PubMed Central

Endothelial CD39 metabolizes ADP released from activated platelets. Recombinant soluble human CD39 (solCD39) potently inhibited ex vivo platelet aggregation in response to ADP and reduced cerebral infarct volumes in mice following transient middle cerebral artery occlusion, even when given 3 hours after stroke. Postischemic platelet and fibrin deposition were decreased and perfusion increased without increasing intracerebral hemorrhage. In contrast, aspirin did not increase postischemic blood flow or reduce infarction volume, but did increase intracerebral hemorrhage. Mice lacking the enzymatically active extracellular portion of the CD39 molecule were generated by replacement of exons 4–6 (apyrase-conserved regions 2–4) with a PGKneo cassette. Although CD39 mRNA 3? of the neomycin cassette insertion site was detected, brains from these mice lacked both apyrase activity and CD39 immunoreactivity. Although their baseline phenotype, hematological profiles, and bleeding times were normal, cd39–/– mice exhibited increased cerebral infarct volumes and reduced postischemic perfusion. solCD39 reconstituted these mice, restoring postischemic cerebral perfusion and rescuing them from cerebral injury. These data demonstrate that CD39 exerts a protective thromboregulatory function in stroke. PMID:11956240

Pinsky, David J.; Broekman, M. Johan; Peschon, Jacques J.; Stocking, Kim L.; Fujita, Tomoyuki; Ramasamy, Ravichandran; Connolly, E. Sander; Huang, Judy; Kiss, Szilard; Zhang, Yuan; Choudhri, Tanvir F.; McTaggart, Ryan A.; Liao, Hui; Drosopoulos, Joan H.F.; Price, Virginia L.; Marcus, Aaron J.; Maliszewski, Charles R.

2002-01-01

15

Regulation of ecto-apyrase CD39 (ENTPD1) expression by phosphodiesterase III (PDE3)  

PubMed Central

The ectoenzyme CD39 suppresses thrombosis and inflammation by suppressing ATP and ADP to AMP. However, mechanisms of CD39 transcriptional and post-translational regulation are not well known. Here we show that CD39 levels are modulated by inhibition of phosphodiesterase 3 (PDE3). RAW macrophages and human umbilical vein endothelial cells (HUVECs) were treated with the PDE3 inhibitors cilostazol and milrinone, then analyzed using qRT-PCR, immunoprecipitation/Western blot, immunofluorescent staining, radio-thin-layer chromatography, a malachite green assay, and ELISA. HUVECs expressed elevated CD39 protein (2-fold [P<0.05] for cilostazol and 2.5-fold [P<0.01] for milrinone), while macrophage CD39 mRNA and protein were both elevated after PDE3 inhibition. HUVEC ATPase activity increased by 25% with cilostazol and milrinone treatment (P<0.05 and P<0.01, respectively), as did ADPase activity (47% and 61%, P<0.001). There was also a dose-dependent elevation of soluble CD39 after treatment with 8-Br-cAMP, with maximal elevation of 60% more CD39 present compared to controls (1 mM, P<0.001). Protein harvested after 8-Br-cAMP treatment showed that ubiquitination of CD39 was decreased by 43% compared to controls. A DMSO or PBS vehicle control was included for each experiment based on solubility of cilostazol, milrinone, and 8-Br-cAMP. These results indicate that PDE3 inhibition regulates endothelial CD39 at a post-translational level.—Baek, A. E., Kanthi, Y., Sutton, N. R., Liao, H., Pinsky, D. J. Regulation of ecto-apyrase CD39 (ENTPD1) expression by phosphodiesterase III (PDE3). PMID:23901069

Baek, Amy E.; Kanthi, Yogendra; Sutton, Nadia R.; Liao, Hui; Pinsky, David J.

2013-01-01

16

Extracellular generation of adenosine by the ectonucleotidases CD39 and CD73 promotes dermal fibrosis.  

PubMed

Adenosine has an important role in inflammation and tissue remodeling and promotes dermal fibrosis by adenosine receptor (A2AR) activation. Adenosine may be formed intracellularly from adenine nucleotides or extracellularly through sequential phosphohydrolysis of released ATP by nucleoside triphosphate diphosphohydrolase (CD39) and ecto-5'-nucleotidase (CD73). Because the role of these ecto-enzymes in fibrosis appears to be tissue specific, we determined whether these ectonucleotidases were directly involved in diffuse dermal fibrosis. Wild-type and mice globally deficient in CD39 knockout (CD39KO), CD73 (CD73KO), or both (CD39/CD73DKO) were challenged with bleomycin. Extracellular adenosine levels and dermal fibrosis were quantitated. Adenosine release from skin cultured ex vivo was increased in wild-type mice after bleomycin treatment but remained low in skin from CD39KO, CD73KO, or CD39/CD73DKO bleomycin-treated mice. Deletion of CD39 and/or CD73 decreased the collagen content, and prevented skin thickening and tensile strength increase after bleomycin challenge. Decreased dermal fibrotic features were associated with reduced expression of the profibrotic mediators, transforming growth factor-?1 and connective tissue growth factor, and diminished myofibroblast population in CD39- and/or CD73-deficient mice. Our work supports the hypothesis that extracellular adenosine, generated in tandem by ecto-enzymes CD39 and CD73, promotes dermal fibrogenesis. We suggest that biochemical or biological inhibitors of CD39 and/or CD73 may hold promise in the treatment of dermal fibrosis in diseases such as scleroderma. PMID:24266925

Fernández, Patricia; Perez-Aso, Miguel; Smith, Gideon; Wilder, Tuere; Trzaska, Sean; Chiriboga, Luis; Franks, Andrew; Robson, Simon C; Cronstein, Bruce N; Chan, Edwin S L

2013-12-01

17

Vascular CD39/ENTPD1 directly promotes tumor cell growth by scavenging extracellular adenosine triphosphate.  

PubMed

Extracellular adenosine triphosphate (ATP) is known to boost immune responses in the tumor microenvironment but might also contribute directly to cancer cell death. CD39/ENTPD1 is the dominant ectonucleotidase expressed by endothelial cells and regulatory T cells and catalyzes the sequential hydrolysis of ATP to AMP that is further degraded to adenosine by CD73/ecto-5'-nucleotidase. We have previously shown that deletion of Cd39 results in decreased growth of transplanted tumors in mice, as a result of both defective angiogenesis and heightened innate immune responses (secondary to loss of adenosinergic immune suppression). Whether alterations in local extracellular ATP and adenosine levels as a result of CD39 bioactivity directly affect tumor growth and cytotoxicity has not been investigated to date. We show here that extracellular ATP exerts antitumor activity by directly inhibiting cell proliferation and promoting cancer cell death. ATP-induced antiproliferative effects and cell death are, in large part, mediated through P2X(7) receptor signaling. Tumors in Cd39 null mice exhibit increased necrosis in association with P2X(7) expression. We further demonstrate that exogenous soluble NTPDase, or CD39 expression by cocultured liver sinusoidal endothelial cells, stimulates tumor cell proliferation and limits cell death triggered by extracellular ATP. Collectively, our findings indicate that local expression of CD39 directly promotes tumor cell growth by scavenging extracellular ATP. Pharmacological or targeted inhibition of CD39 enzymatic activity may find utility as an adjunct therapy in cancer management. PMID:21390184

Feng, Lili; Sun, Xiaofeng; Csizmadia, Eva; Han, Lihui; Bian, Shu; Murakami, Takashi; Wang, Xin; Robson, Simon C; Wu, Yan

2011-03-01

18

Rapamycin Regulates iTreg Function through CD39 and Runx1 Pathways  

PubMed Central

It has been shown that rapamycin is able to significantly increase the expression of FoxP3 and suppress activity in induced Treg (iTreg) cells in vivo and in vitro. CD39 is a newly determined Treg marker that relates to cell suppression. Runx1, a regulator of FoxP3, controls the expression of adenosine deaminase (ADA) gene, which is found recently in the downstream of CD39 pathway in trophoblast cells. Whether rapamycin would influence CD39 pathway and regulate the expression of Runx1 remains to be determined. The addition of rapamycin to human CD4+ naïve cells in the presence of IL-2, TGF-? promotes the expression of FoxP3. In this paper, we found that CD39 positively correlated with the FoxP3 expression in iTreg cells. Rapamycin induced iTreg cells showed a stronger CD39/Runx1 expression with the enhanced suppressive function. These data suggested that CD39 expression was involved in iTreg generation and the enhanced suppressive ability of rapamycin induced Treg was partly due to Runx1 pathway. We conclude that rapamycin favors CD39/Runx1 expression in human iTreg and provides a novel insight into the mechanisms of iTreg generation enhanced by rapamycin. PMID:24741640

Lu, Yunjie; Wang, Jirong; Gu, Jian; Lu, Hao; Li, Xiangcheng; Qian, Xiaofeng; Liu, Xiaoshan; Wang, Xuehao; Zhang, Feng; Lu, Ling

2014-01-01

19

Increased CD39 Nucleotidase Activity on Microparticles from Patients with Idiopathic Pulmonary Arterial Hypertension  

PubMed Central

Background Idiopathic pulmonary arterial hypertension (IPAH) is a devastating disease characterized by increased pulmonary vascular resistance, smooth muscle and endothelial cell proliferation, perivascular inflammatory infiltrates, and in situ thrombosis. Circulating intravascular ATP, ADP, AMP and adenosine activate purinergic cell signaling pathways and appear to induce many of the same pathologic processes that underlie IPAH. Extracellular dephosphorylation of ATP to ADP and AMP occurs primarily via CD39 (ENTPD1), an ectonucleotidase found on the surface of leukocytes, platelets, and endothelial cells [1]. Microparticles are micron-sized phospholipid vesicles formed from the membranes of platelets and endothelial cells. Objectives: Studies here examine whether CD39 is an important microparticle surface nucleotidase, and whether patients with IPAH have altered microparticle-bound CD39 activity that may contribute to the pathophysiology of the disease. Methodology/ Principal Findings Kinetic parameters, inhibitor blocking experiments, and immunogold labeling with electron microscopy support the role of CD39 as a major nucleotidase on the surface of microparticles. Comparison of microparticle surface CD39 expression and nucleotidase activity in 10 patients with advanced IPAH and 10 healthy controls using flow cytometry and thin layer chromatograph demonstrate the following: 1) circulating platelet (CD39+CD31+CD42b+) and endothelial (CD39+CD31+CD42b?) microparticle subpopulations in patients with IPAH show increased CD39 expression; 2) microparticle ATPase and ADPase activity in patients with IPAH is increased. Conclusions/ Significance We demonstrate for the first time increased CD39 expression and function on circulating microparticles in patients with IPAH. Further research is needed to elucidate whether these findings identify an important trigger for the development of the disease, or reflect a physiologic response to IPAH. PMID:22792409

Visovatti, Scott H.; Hyman, Matthew C.; Bouis, Diane; Neubig, Richard; McLaughlin, Vallerie V.; Pinsky, David J.

2012-01-01

20

Increased plasma levels of microparticles expressing CD39 and CD133 in acute liver injury  

PubMed Central

Background We have previously demonstrated that CD133 and CD39 are expressed by hematopoietic stem cells (HSC), which are mobilized after liver injury and target sites of injury, limit vascular inflammation and boost hepatic regeneration. Plasma microparticles (MP) expressing CD39 can block endothelial activation. Here, we tested whether CD133+ MP might be shed in a CD39-dependent manner in a model of liver injury and could potentially serve as biomarkers of liver failure in the clinic. Methods Wild type and Cd39 null mice were subjected to acetaminophen (APAP)-induced liver injury. Mice were sacrificed and plasma MP isolated by ultracentrifugation. HSC and CD133+ MP levels were analyzed by FACS. Patients were enrolled with acute (n = 5) and acute on chronic (n = 5) liver injury with matched controls (n = 7). Blood was collected at admission and plasma CD133+ and CD39+ MP subsets were analysed by FACS. Results HSC and CD133+ MP levels were significantly increased only in the plasma of wild type mice with APAP-hepatoxicity (p<0.05). No increases in CD133+ MP were noted in Cd39 null mice. Plasma MP increases were observed in patients with liver injury. These MP were characterized by significantly higher levels of CD39 (P< 0.05). Conclusions HSC and plasma CD133+ MP levels increase in a CD39-dependent manner during experimental acute liver injury. Increased levels of CD39+ MP are differentially noted in patients with liver injury. Further research is needed to determine whether MP fluxes are secondary to pathophysiologic insults to the liver or might reflect compensatory responses. PMID:23232366

Schmelzle, Moritz; Splith, Katrin; Andersen, Lars W.; Kornek, Miroslaw; Schuppan, Detlef; Jones-Bamman, Caitlin; Nowak, Martina; Toxavidis, Vasilis; Salhanick, Steven D.; Han, Lihui; Schulte am Esch, Jan; Jonas, Sven; Donnino, Michael W.; Robson, Simon C.

2012-01-01

21

The Protective Effects of CD39 Overexpression in Multiple Low-Dose Streptozotocin-Induced Diabetes in Mice  

PubMed Central

Islet allograft survival limits the long-term success of islet transplantation as a potential curative therapy for type 1 diabetes. A number of factors compromise islet survival, including recurrent diabetes. We investigated whether CD39, an ectonucleotidase that promotes the generation of extracellular adenosine, would mitigate diabetes in the T cell–mediated multiple low-dose streptozotocin (MLDS) model. Mice null for CD39 (CD39KO), wild-type mice (WT), and mice overexpressing CD39 (CD39TG) were subjected to MLDS. Adoptive transfer experiments were performed to delineate the efficacy of tissue-restricted overexpression of CD39. The role of adenosine signaling was examined using mutant mice and pharmacological inhibition. The susceptibility to MLDS-induced diabetes was influenced by the level of expression of CD39. CD39KO mice developed diabetes more rapidly and with higher frequency than WT mice. In contrast, CD39TG mice were protected. CD39 overexpression conferred protection through the activation of adenosine 2A receptor and adenosine 2B receptor. Adoptive transfer experiments indicated that tissue-restricted overexpression of CD39 conferred robust protection, suggesting that this may be a useful strategy to protect islet grafts from T cell–mediated injury. PMID:23364452

Chia, Joanne S.J.; McRae, Jennifer L.; Thomas, Helen E.; Fynch, Stacey; Elkerbout, Lorraine; Hill, Prue; Murray-Segal, Lisa; Robson, Simon C.; Chen, Jiang-Fan; d'Apice, Anthony J.F.; Cowan, Peter J.; Dwyer, Karen M.

2013-01-01

22

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

PubMed Central

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

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

2013-01-01

23

Fingolimod Increases CD39-Expressing Regulatory T Cells in Multiple Sclerosis Patients  

PubMed Central

Background Multiple sclerosis (MS) likely results from an imbalance between regulatory and inflammatory immune processes. CD39 is an ectoenzyme that cleaves ATP to AMP and has been suggested as a novel regulatory T cells (Treg) marker. As ATP has numerous proinflammatory effects, its degradation by CD39 has anti-inflammatory influence. The purpose of this study was to explore regulatory and inflammatory mechanisms activated in fingolimod treated MS patients. Methods and Findings Peripheral blood mononuclear cells (PBMCs) were isolated from relapsing-remitting MS patients before starting fingolimod and three months after therapy start. mRNA expression was assessed in ex vivo PBMCs. The proportions of CD8, B cells, CD4 and CD39-expressing cells were analysed by flow cytometry. Treg proportion was quantified by flow cytometry and methylation-specific qPCR. Fingolimod treatment increased mRNA levels of CD39, AHR and CYP1B1 but decreased mRNA expression of IL-17, IL-22 and FOXP3 mRNA in PBMCs. B cells, CD4+ cells and Treg proportions were significantly reduced by this treatment, but remaining CD4+ T cells were enriched in FOXP3+ cells and in CD39-expressing Tregs. Conclusions In addition to the decrease in circulating CD4+ T cells and CD19+ B cells, our findings highlight additional immunoregulatory mechanisms induced by fingolimod. PMID:25411844

Muls, Nathalie; Dang, Hong Anh; Sindic, Christian J. M.; van Pesch, Vincent

2014-01-01

24

Liver damage and systemic inflammatory responses are exacerbated by the genetic deletion of CD39 in total hepatic ischemia.  

PubMed

Liver ischemia reperfusion injury is associated with both local damage to the hepatic vasculature and systemic inflammatory responses. CD39 is the dominant vascular endothelial cell ectonucleotidase and rapidly hydrolyses both adenosine triphosphate (ATP) and adenosine diphosphate to adenosine monophosphate. These biochemical properties, in tandem with 5'-nucleotidases, generate adenosine and potentially illicit inflammatory vascular responses and thrombosis. We have evaluated the role of CD39 in total hepatic ischemia reperfusion injury (IRI). Wildtype mice, Cd39-hemizygous mice (+/-) and matched Cd39-null mice (-/-); (n?=?25 per group) underwent 45 min of total warm ischemia with full inflow occlusion necessitating partial hepatectomy. Soluble nucleoside triphosphate diphosphohydrolase (NTPDases) or adenosine/amrinone were administered to wildtype (n?=?6) and Cd39-null mice (n?=?6) in order to study protective effects in vivo. Parameters of liver injury, systemic inflammation, hepatic ATP determinations by P(31)-NMR and parameters of lung injury were obtained. All wildtype mice survived up to 7 days with minimal biochemical disturbances and minor evidence for injury. In contrast, 64% of Cd39+/- and 84% of Cd39-null mice required euthanasia or died within 4 h post-reperfusion with liver damage and systemic inflammation associated with hypercytokinemia. Hepatic ATP depletion was pronounced in Cd39-null mice posthepatic IRI. Soluble NTPDase or adenosine administration protected Cd39-deficient mice from acute reperfusion injury. We conclude that CD39 is protective in hepatic IRI preventing local injury and systemic inflammation in an adenosine dependent manner. Our data indicate that vascular CD39 expression has an essential protective role in hepatic IRI. PMID:21656186

Sun, Xiaofeng; Imai, Masato; Nowak-Machen, Martina; Guckelberger, Olaf; Enjyoji, Keiichi; Wu, Yan; Khalpey, Zain; Berberat, Pascal; Munasinghe, Jeeva; Robson, Simon Christopher

2011-12-01

25

CD39 Modulates Hematopoietic Stem Cell Recruitment and Promotes Liver Regeneration in Mice and Humans After Partial Hepatectomy  

PubMed Central

Objective To study molecular mechanisms involved in hematopoietic stem cell (HSC) mobilization after liver resection and determine impacts on liver regeneration. Background Extracellular nucleotide-mediated cell signaling has been shown to boost liver regeneration. Ectonucleotidases of the CD39 family are expressed by bone marrow–derived cells, and purinergic mechanisms might also impact mobilization and functions of HSC after liver injury. Methods Partial hepatectomy was performed in C57BL/6 wild-type, Cd39 ectonucleotidase-null mice and in chimeric mice after transplantation of wild-type or Cd39-null bone marrow. Bone marrow–derived HSCs were purified by fluorescence-activated cell sorting and administered after hepatectomy. Chemotactic studies were performed to examine effects of purinergic receptor agonists and antagonists in vitro. Mobilization of human HSCs and expression of CD39 were examined and linked to the extent of resection and liver tests. Results Subsets of HSCs expressing Cd39 are preferentially mobilized after partial hepatectomy. Chemotactic responses of HSCs are increased by CD39-dependent adenosine triphosphate hydrolysis and adenosine signaling via A2A receptors in vitro. Mobilized Cd39high HSCs boost liver regeneration, potentially limiting interleukin 1? signaling. In clinical studies, mobilized human HSCs also express CD39 at high levels. Mobilization of HSCs correlates directly with the restoration of liver volume and function after partial hepatectomy. Conclusions We demonstrate CD39 to be a novel HSC marker that defines a functionally distinct stem cell subset in mice and humans. HSCs are mobilized after liver resection, limit inflammation, and boost regeneration in a CD39-dependent manner. These observations have implications for monitoring and indicate future therapeutic avenues. PMID:23474584

Schmelzle, Moritz; Duhme, Constanze; Junger, Wolfgang; Salhanick, Steven D.; Chen, Yu; Wu, Yan; Toxavidis, Vasilis; Csizmadia, Eva; Han, Lihui; Bian, Shu; Fürst, Günter; Nowak, Martina; Karp, Seth J.; Knoefel, Wolfram T.

2014-01-01

26

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

Microsoft Academic Search

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

Alison Grinthal; Guido Guidotti

2006-01-01

27

CD39 is the dominant Langerhans cell–associated ecto-NTPDase: Modulatory roles in inflammation and immune responsiveness  

Microsoft Academic Search

CD39, the endothelial ecto-nucleoside triphosphate diphosphohydrolase (NTPDase), regulates vascular inflammation and thrombosis by hydrolyzing ATP and ADP. Although ecto-NTPDase activities have been used as a marker of epidermal dendritic cells (DCs) known as Langerhans cells, the identity and function of these activities remain unknown. Here we report that Langerhans cells in CD39?\\/? mice express no detectable ecto-NTPDase activity. Irritant chemicals

Norikatsu Mizumoto; Tadashi Kumamoto; Simon C. Robson; Jean Sévigny; Hiroyuki Matsue; Keiichi Enjyoji; Akira Takashima

2002-01-01

28

Delayed targeting of CD39 to activated platelet GPIIb/IIIa via a single-chain antibody: breaking the link between antithrombotic potency and bleeding?  

PubMed Central

The ecto-nucleoside triphosphate diphosphohydrolase CD39 represents a promising antithrombotic therapeutic. It degrades adenosine 5?-diphosphate (ADP), a main platelet activating/recruiting agent. We hypothesized that delayed enrichment of CD39 on developing thrombi will allow for a low and safe systemic concentration and thus avoid bleeding. We use a single-chain antibody (scFv, specific for activated GPIIb/IIIa) for targeting CD39. This should allow delayed enrichment on growing thrombi but not on the initial sealing layer of platelets, which do not yet express activated GPIIb/IIIa. CD39 was recombinantly fused to an activated GPIIb/IIIa-specific scFv (targ-CD39) and a nonfunctional scFv (non–targ-CD39). Targ-CD39 was more effective at preventing ADP-induced platelet activation than non–targ-CD39. In a mouse carotid artery thrombosis model, non–targ-CD39, although protective against vessel occlusion, was associated with significant bleeding on tail transection. In contrast, targ-CD39 concentrated at the thrombus site; hence, a dose ?10 times less of CD39 prevented vessel occlusion to a similar extent as high-dose non–targ-CD39, without prolonged bleeding time. An equimolar dose of non–targ-CD39 at this low concentration was ineffective at preventing vessel occlusion. Thus, delayed targeting of CD39 via scFv to activated platelets provides strong antithrombotic potency and yet prevents bleeding and thereby promotes CD39 toward clinical use. PMID:23380744

Hohmann, Jan David; Wang, Xiaowei; Krajewski, Stefanie; Selan, Carly; Haller, Carolyn A.; Straub, Andreas; Chaikof, Elliot L.; Nandurkar, Harshal H.; Hagemeyer, Christoph E.

2013-01-01

29

Delayed targeting of CD39 to activated platelet GPIIb/IIIa via a single-chain antibody: breaking the link between antithrombotic potency and bleeding?  

PubMed

The ecto-nucleoside triphosphate diphosphohydrolase CD39 represents a promising antithrombotic therapeutic. It degrades adenosine 5'-diphosphate (ADP), a main platelet activating/recruiting agent. We hypothesized that delayed enrichment of CD39 on developing thrombi will allow for a low and safe systemic concentration and thus avoid bleeding. We use a single-chain antibody (scFv, specific for activated GPIIb/IIIa) for targeting CD39. This should allow delayed enrichment on growing thrombi but not on the initial sealing layer of platelets, which do not yet express activated GPIIb/IIIa. CD39 was recombinantly fused to an activated GPIIb/IIIa-specific scFv (targ-CD39) and a nonfunctional scFv (non-targ-CD39). Targ-CD39 was more effective at preventing ADP-induced platelet activation than non-targ-CD39. In a mouse carotid artery thrombosis model, non-targ-CD39, although protective against vessel occlusion, was associated with significant bleeding on tail transection. In contrast, targ-CD39 concentrated at the thrombus site; hence, a dose ?10 times less of CD39 prevented vessel occlusion to a similar extent as high-dose non-targ-CD39, without prolonged bleeding time. An equimolar dose of non-targ-CD39 at this low concentration was ineffective at preventing vessel occlusion. Thus, delayed targeting of CD39 via scFv to activated platelets provides strong antithrombotic potency and yet prevents bleeding and thereby promotes CD39 toward clinical use. PMID:23380744

Hohmann, Jan David; Wang, Xiaowei; Krajewski, Stefanie; Selan, Carly; Haller, Carolyn A; Straub, Andreas; Chaikof, Elliot L; Nandurkar, Harshal H; Hagemeyer, Christoph E; Peter, Karlheinz

2013-04-18

30

Defective renal water handling in transgenic mice over-expressing human CD39/NTPDase1  

PubMed Central

Ectonucleoside triphosphate diphosphohydrolase-1 hydrolyzes extracellular ATP and ADP to AMP. Previously, we showed that CD39 is expressed at several sites within the kidney and thus may impact the availability of type 2 purinergic receptor (P2-R) ligands. Because P2-Rs appear to regulate urinary concentrating ability, we have evaluated renal water handling in transgenic mice (TG) globally overexpressing hCD39. Under basal conditions, TG mice exhibited significantly impaired urinary concentration and decreased protein abundance of AQP2 in the kidney compared with wild-type (WT) mice. Urinary excretion of total nitrates/nitrites was significantly higher in TG mice, but the excretion of AVP or PGE2 was equivalent to control WT mice. There were no significant differences in electrolyte-free water clearance or fractional excretion of sodium. Under stable hydrated conditions (gelled diet feeding), the differences between the WT and TG mice were negated, but the decrease in urine osmolality persisted. When water deprived, TG mice failed to adequately concentrate urine and exhibited impaired AVP responses. However, the increases in urinary osmolalities in response to subacute dDAVP or chronic AVP treatment were similar in TG and WT mice. These observations suggest that TG mice have impaired urinary concentrating ability despite normal AVP levels. We also note impaired AVP release in response to water deprivation but that TG kidneys are responsive to exogenous dDAVP or AVP. We infer that heightened nucleotide scavenging by increased levels of CD39 altered the release of endogenous AVP in response to dehydration. We propose that ectonucleotidases and modulated purinergic signaling impact urinary concentration and indicate potential utility of targeted therapy for the treatment of water balance disorders. PMID:22622462

Zhang, Yue; Morris, Kaiya L.; Sparrow, Shannon K.; Dwyer, Karen M.; Enjyoji, Keiichi; Robson, Simon C.

2012-01-01

31

Genetic analysis of an allergic rhinitis cohort reveals an intercellular epistasis between FAM134B and CD39  

PubMed Central

Background Extracellular ATP is a pro-inflammatory molecule released by damaged cells. Regulatory T cells (Treg) can suppress inflammation by hydrolysing this molecule via ectonucleoside triphosphate diphosphohydrolase 1 (ENTPD1), also termed as CD39. Multiple studies have reported differences in CD39+ Treg percentages in diseases such as multiple sclerosis, Hepatitis B and HIV-1. In addition, CD39 polymorphisms have been implicated in immune-phenotypes such as susceptibility to inflammatory bowel disease and AIDS progression. However none of the studies published so far has linked disease-associated variants with differences in CD39 Treg surface expression. This study aims at identifying variants affecting CD39 expression on Treg and at evaluating their association with allergic rhinitis, a disease characterized by a strong Treg involvement. Methods Cohorts consisting of individuals of different ethnicities were employed to identify any association of CD39 variants to surface expression. Significant variant(s) were tested for disease association in a published GWAS cohort by one-locus and two-locus genetic analyses based on logistic models. Further functional characterization was performed using existing microarray data and quantitative RT-PCR on sorted cells. Results Our study shows that rs7071836, a promoter SNP in the CD39 gene region, affects the cell surface expression on Treg cells but not on other CD39+ leukocyte subsets. Epistasis analysis revealed that, in conjunction with a SNP upstream of the FAM134B gene (rs257174), it increased the risk of allergic rhinitis (P?=?1.98?×?10-6). As a promoter SNP, rs257174 controlled the expression of the gene in monocytes but, notably, not in Treg cells. Whole blood transcriptome data of three large cohorts indicated an inverse relation in the expression of the two proteins. While this observation was in line with the epistasis data, it also implied that a functional link must exist. Exposure of monocytes to extracellular ATP resulted in an up-regulation of FAM134B gene expression, suggesting that extracellular ATP released from damaged cells represents the connection for the biological interaction of CD39 on Treg cells with FAM134B on monocytes. Conclusions The interplay between promoter SNPs of CD39 and FAM134B results in an intercellular epistasis which influences the risk of a complex inflammatory disease. PMID:24970562

2014-01-01

32

The Role of Ectonucleotidases CD39 and CD73 and Adenosine Signaling in Solid Organ Transplantation  

PubMed Central

Extracellular adenosine is a potent immunomodulatory molecule that accumulates in states of inflammation. Nucleotides such as adenosine triphosphate and adenosine diphosphate are release from injured and necrotic cells and hydrolyzed to adenosine monophosphate and adenosine by the concerted action of the ectonucleotidases CD39 and CD73. Accumulating evidence suggest that purinergic signaling is involved in the inflammatory response that accompanies acute rejection and chronic allograft dysfunction. Modification of the purinergic pathway has been shown to alter graft survival in a number of solid organ transplant models and the response to ischemia–reperfusion injury (IRI). Furthermore, the purinergic pathway is intrinsically involved in B and T cell biology and function. Although T cells have traditionally been considered the orchestrators of acute allograft rejection, a role for B cells in chronic allograft loss is being increasingly appreciated. This review focuses on the role of the ectonucleotidases CD39 and CD73 and adenosine signaling in solid organ transplantation including the effects on IRI and T and B cell biology. PMID:24600452

Roberts, Veena; Stagg, John; Dwyer, Karen M.

2013-01-01

33

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

PubMed Central

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

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

2013-01-01

34

T-cell specific defect in expression of the NTPDase CD39 as a biomarker for lupus.  

PubMed

Regulatory T cells (T(regs)) are critical for maintenance of peripheral tolerance via suppression of T-cell responses, and absence of T(regs) results in autoimmunity. The role of aberrations in the T(reg) pool for the development of systemic lupus erythematosus (SLE, lupus) remains uncertain. T(reg)-mediated generation of adenosine, dependent on the ectonucleotidase CD39, is an important mechanism for suppression of T-cell responses. We tested whether decreases in numbers of T(regs), and specifically CD39-expressing T(regs), are associated with human lupus. We studied 15 SLE patients, six patients with rheumatoid arthritis (RA) and 24 healthy controls. T(reg) phenotypic markers, including CD39 expression, were studied by flow cytometry. Varying numbers of sorted T(regs) cells were co-cultured with responder T (T(resp)) cells, with proliferation assessed by (3)H-thymidine incorporation. The proportion of T(regs) as defined by Foxp3(+) CD25(+high) CD127(-/low) was similar in lupus and control populations. CD39-expressing T(regs) comprised 37±13% of the T(reg) population in healthy controls and 36±21% in lupus subjects using nonsteroidal immunosuppressants to control active disease, but was nearly absent in five of six lupus subjects with minimally active disease. In contrast to healthy controls and lupus subjects without the CD39 defect, in SLE subjects with the CD39 defect, adenosine-dependent T(reg)-mediated suppression was nearly absent. These results suggest that functional defects in T(regs), rather than reduced T(reg) numbers, are important for the loss of peripheral tolerance in lupus. Presentation of this defect may serve as a biomarker for untreated disease. PMID:21763644

Loza, Matthew J; Anderson, A Shane; O'Rourke, Kenneth S; Wood, James; Khan, Islam U

2011-01-01

35

Expression of CD39 mRNA is altered in the peripheral blood of patients with allergic asthma  

PubMed Central

The ectoenzyme CD39 hydrolyzes extracellular adenosine 5?-triphosphate (ATP), which possesses pro-inflammatory properties. However, the role of CD39 in allergic asthma has not been fully elucidated. A total of 18 patients with persistent asthma who were allergic to house dust mites and 19 healthy volunteers were enrolled in this study. The expression of CD39, GATA3, RAR-related orphan receptor ? (ROR-?t) and forkhead box P3 (FoxP3) mRNA in peripheral blood mononuclear cells (PBMCs) was determined by SYBR-Green I quantitative polymerase chain reaction (qPCR). The cytokines interleukin (IL)-4, IL-17A, transforming growth factor ? (TGF-?) and DP.sIgE were detected by enzyme-linked immunosorbent assay. Our data demonstrated that the expression of CD39 mRNA in PBMCs from asthmatic patients was significantly lower compared to that in normal controls [(1.49±0.59)×10?3 vs. (2.17±0.77)×10?3, respectively; P<0.01]. CD39 mRNA was negatively correlated with serum IL-4, IL-17A and GATA3 expression (r=?0.468, P<0.05; r=?0.550, P<0.05; and r=?0.424, P<0.01, respectively) and positively correlated with FoxP3 and TGF-? expression (r=0.373, P<0.05; and r=0.425, P<0.05, respectively). There was no obvious correlation between CD39 and ROR-?t expression (r=?0.259, P=0.122). These data suggested that CD39 mRNA expression was downregulated in allergic asthma, which was positively correlated with serum IL-4, IL-17A and GATA3 expression and negatively correlated with serum TGF-? and FoxP3 expression, whereas there was no correlation with ROR-?t. Therefore, it was hypothesized that CD39 may participate in the occurrence and progression of allergic asthma. PMID:24649072

WANG, LIN-LIN; TANG, PING-HUA; SHI, CHAO-GUO; WAN, YING-HUAN; TANG, WEI; HOU, XIA-XIAO; PAN, NA-LI; SHI, YU-BAO; TAO, QIN-LIAN

2014-01-01

36

NTPDase and 5? ecto-nucleotidase expression profiles and the pattern of extracellular ATP metabolism in the Walker 256 tumor  

Microsoft Academic Search

In this study, we evaluated the NTPDases and ecto-5?-nucleotidase (CD73) expression profiles and the pattern of adenine nucleotide hydrolysis in rats submitted to the Walker 256 tumor model, 6, 10 and 15 days after the subcutaneous inoculation. Using RT-PCR analysis, we identified mRNA for all of the members of the ecto-nucleoside triphosphate diphosphohydrolase family investigated and a 5?-nucleotidase. By quantitative real-time

A. Buffon; M. R. Wink; B. V. Ribeiro; E. A. Casali; T. A. Libermann; L. F. Zerbini; S. C. Robson; J. J. F. Sarkis

2007-01-01

37

T-cell specific defect in expression of the NTPDase CD39 as a biomarker for lupus  

Microsoft Academic Search

Regulatory T cells (Tregs) are critical for maintenance of peripheral tolerance via suppression of T-cell responses, and absence of Tregs results in autoimmunity. The role of aberrations in the Treg pool for the development of systemic lupus erythematosus (SLE, lupus) remains uncertain. Treg-mediated generation of adenosine, dependent on the ectonucleotidase CD39, is an important mechanism for suppression of T-cell responses.

Matthew J. Loza; A. Shane Anderson; Kenneth S. O’Rourke; James Wood; Islam U. Khan

2011-01-01

38

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

PubMed Central

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

2014-01-01

39

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

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

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

2014-09-01

40

Characterization of NTPDase (NTPDase1; ecto-apyrase; ecto-diphosphohydrolase; CD39; EC 3.6.1.5) activity in human lymphocytes  

Microsoft Academic Search

Human lymphocytes contain NTPDase (NTPDase-1; ecto-apyrase; ecto-diphosphohydrolase; CD39; EC 3.6.1.5), a cation-dependent enzyme that hydrolyzes ATP and ADP and also other di- and triphosphate nucleosides, acting at an optimum pH of 8.0. A significant inhibition of ATP and ADP hydrolysis (P<0.05) was observed in the presence of 20 mM sodium azide. NTPDase inhibitors, 20 mM sodium fluoride, 0.2 mM trifluoperazine

Daniela B. R. Leal; Cristiane A. Streher; Tiago N. Neu; Fábio P. Bittencourt; Cláudio A. M. Leal; José E. P. da Silva; Vera M. Morsch; Maria R. C. Schetinger

2005-01-01

41

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

PubMed Central

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

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

42

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

PubMed Central

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

Hausler, Sebastian FM; del Barrio, Itsaso Montalban; Diessner, Joachim; Stein, Roland G; Strohschein, Jenny; Honig, Arnd; Dietl, Johannes; Wischhusen, Jorg

2014-01-01

43

Particulate Matter  

MedlinePLUS

... EPA Home Air & Radiation Six Common Pollutants Particulate Matter Announcements March 13, 2013 - An updated “Strategies ... for over 300 cities across the U.S. "Particulate matter," also known as particle pollution or PM, is ...

44

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

PubMed Central

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

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

2013-01-01

45

Cloning and characterization of the ecto-nucleotidase NTPDase3 from rat brain: Predicted secondary structure and relation to other members of the E-NTPDase family and actin  

Microsoft Academic Search

The protein family of ecto-nucleoside triphosphate diphosphohydrolases (E-NTPDase family) contains multiple members that hydrolyze\\u000a nucleoside 5’-triphosphates and nucleoside 5’-diphosphates with varying preference for the individual type of nucleotide.\\u000a We report the cloning and functional expression of rat NTPDase3. The rat brain-derived cDNA has an open reading frame of 1590 bp\\u000a encoding 529 amino acid residues, a calculated molecular mass of 59.1 kDa

Thomas Vorhoff; Herbert Zimmermann; Julie Pelletier; Jean Sévigny; Norbert Braun

2005-01-01

46

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

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,

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

2004-01-01

47

Pitch based foam with particulate  

DOEpatents

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

Klett, James W. (Knoxville, TN)

2001-01-01

48

Particulate Air Pollution: The Particulars  

ERIC Educational Resources Information Center

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

Murphy, James E.

1973-01-01

49

Fine particulate capture device  

NASA Technical Reports Server (NTRS)

To capture fine particulate matter in a gas such as air, a dielectric fluid is directed to the center of whichever face of a rotating disc is exposed to the air flow. The disc is comprised of two or more segments which bear opposite electrostatic potentials. As the dielectric fluid is centrifuged towards the periphery of the rotating disc, the fluid becomes charged to the same potential as the segment over which it is passing. Particulate matter is attracted to the charged segment and is captured by the fluid. The fluid then carries the captured particulate matter to a collection device such as a toroidal container disposed around the periphery of the disc. A grounded electrically-conductive ring may be disposed at the outer periphery of the disc to neutralize the captured particles and the fluid before they enter the container.

Peterson, V. S.; Siewert, R. D. (inventors)

1979-01-01

50

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...

51

Analysis of microsize particulates  

NASA Technical Reports Server (NTRS)

Unique methods for analyzing individual particles ranging in size from 0.01 to 1000 micrometers have been developed for investigation of nature of cosmic dust. Methods are applicable to particulate aerosols and contaminants characteristically encountered in studies of air pollution and in experiments designed to abate pollution.

Blanchard, M. B.; Farlow, N. H.; Ferry, G. V.

1972-01-01

52

Fluid&ParticulateSystems 424514/2010  

E-print Network

Fluid&ParticulateSystems 424514/2010 Fluid&ParticulateSystems Ã?A424514/2014 Fluid and Particulate Engineering ron.zevenhoven@abo.fi 3Fluid&ParticulateSystems 424514/2010 Fluid&ParticulateSystems Ã?A424514&ParticulateSystems 424514/2010 Fluid&ParticulateSystems Ã?A424514/2014 Flow Around BodiesFluid&ParticulateSystems 424514/2010

Zevenhoven, Ron

53

Particulate matter dynamics  

E-print Network

A substantial fraction of the particulate matter released into the atmosphere by industrial or natural processes corresponds to particles whose aerodynamic diameters are greater than 50 mm. It has been shown that, for these particles, the classical description of Gaussian plume diffusion processes, is inadequate to describe the transport and deposition. In this paper we present new results concerning the dispersion of coarse particulate matter. The simulations are done with our own code that uses the Bulirsch Stoer numerical integrator to calculate threedimensional trajectories of particles released into the environment under very general conditions. Turbulent processes are simulated by the Langevin equation and weather conditions are modeled after stable (Monin-Obukhov length L> 0) and unstable conditions (L particles.

Cionco, Rodolfo G; Caligaris, Marta G

2012-01-01

54

Regenerable particulate filter  

DOEpatents

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

Stuecker, John N. (Albuquerque, NM); Cesarano, III, Joseph (Albuquerque, NM); Miller, James E. (Albuquerque, NM)

2009-05-05

55

Eighth particulate control symposium  

SciTech Connect

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

Not Available

1990-11-01

56

Adenosine and Gastrointestinal Inflammation  

PubMed Central

Nucelosides such as adenosine (Ado) influence nearly every aspect of physiology and pathophysiology. Extracellular nucleotides liberated at local sites of inflammation are metabolized through regulated phosphohydrolysis by a series of ecto-nucleotidases including ectonucleoside triphosphate diphosphohydrolase-1 (CD39) and ecto-5?-nucleotidase (CD73), found on the surface of a variety of cell types. Once generated, Ado is made available to bind and activate one of four G-protein-coupled Ado receptors. Recent in vitro and in vivo studies implicate Ado in a broad array of tissue protective mechanisms that provide new insight into adenosine actions. Studies in cultured cells and murine tissues have indicated that Ado receptors couple to novel post-translational protein modifications, including Cullin deneddylation, as a new anti-inflammatory mechanism. Studies in Ado receptor-null mice have been revealing and indicate a particularly important role for the Ado A2B receptor in animal models of intestinal inflammation. Here, we review contributions of Ado to cell and tissue stress responses, with a particular emphasis on the gastrointestinal mucosa. PMID:23296303

Colgan, Sean P.; Fennimore, Blair; Ehrentraut, Stefan F.

2013-01-01

57

Airborne Particulate Threat Assessment  

SciTech Connect

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.

Patrick Treado; Oksana Klueva; Jeffrey Beckstead

2008-12-31

58

Fluid&ParticulateSystems 424514/2010  

E-print Network

Fluid&ParticulateSystems 424514/2010 Fluid&ParticulateSystems �A424514/2014 Fluid and Particulate Zevenhoven �A Thermal and Flow Engineering ron.zevenhoven@abo.fi 8Fluid&ParticulateSystems 424514/2010 Fluid Strömningsteknik Biskopsgatan 8, FI-20500 �bo / Turku Finland #12;Fluid&ParticulateSystems 424514/2010 Fluid

Zevenhoven, Ron

59

Particulate technology issues  

SciTech Connect

Advanced systems for power generation based on coal combustion or gasification will require effective particulate control both for protection of equipment in the gas stream and for compliance with environmental regulations. These new classes of systems will require efficient removal of particles from gas streams at high temperature and high pressure. Primary candidates for particulate control are various types of ceramic filter systems; however, the long-term effects of hot gases and fine particles on the structure and filtration effectiveness of potential filter materials require further study. Thermal gradients induced by pulse cleaning are also of concern. Long-term ``patch tests`` will be conducted on ceramic disks of the same materials used in the fabrication of ceramic candles and ceramic crossflow filters. The primary issues to be addressed in these tests are the long-term physical, thermal, and chemical stability of the ceramic materials; long-term pressure drop and filtration characteristics of the ceramic filters; potential for irreversible blinding of filter elements; and long term performance and reliability of auxiliary hardware, such as the tube sheet and pulse cleaning systems. Each long-term patch test will require about 3 to 4 months of nearly continuous operation.

Pontius, D.H.; Vann Bush, P.

1992-12-01

60

PARTICULATE CONTROL FOR FUGITIVE DUST  

EPA Science Inventory

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

61

Fluid&ParticulateSystems 424514/2010  

E-print Network

Fluid&ParticulateSystems 424514/2010 Fluid&ParticulateSystems Ã?A424514/2014 Fluid and Particulate.zevenhoven@abo.fi 2Fluid&ParticulateSystems 424514/2010 Fluid&ParticulateSystems Ã?A424514/2014 2.1 Flow tube sections-20500 Ã?bo / Turku Finland RoNz 2januari 2014 #12;Fluid&ParticulateSystems 424514/2010 Fluid

Zevenhoven, Ron

62

Spacecraft particulate sizing spectrometer  

NASA Technical Reports Server (NTRS)

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

Miranda, Henry A., Jr.

1992-01-01

63

Particulate erosion mechanisms  

NASA Technical Reports Server (NTRS)

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

Veerabhadrarao, P.; Buckley, D. H.

1983-01-01

64

Micromechanics for particulate reinforced composites  

NASA Technical Reports Server (NTRS)

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.

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

1996-01-01

65

Electrically heated particulate filter restart strategy  

SciTech Connect

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

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

2011-07-12

66

Compact hybrid particulate collector (COHPAC)  

SciTech Connect

This patent describes a method for retrofit filtering of particulates in a flue gas from a combustion source having an existing conventional electrostatic precipitator connected thereto and a smoke stack connected to the precipitator. It comprises: removing at least one discharge electrode and collecting electrode from within the housing of the electrostatic precipitator; attaching a tubesheet within the housing; supporting a compact baghouse filter within the separate filter section by the tubesheet; whereby the remaining discharge electrodes and corresponding collecting electrodes in the electrostatis precipitator serve to remove a majority of particulates form the flue gas and impart a residual charge on remaining particulates discharged to the separate filter section, and the remaining particulates are collected by the baghouse filter before the residual electric charge substantially dissipates.

Chang, R.

1992-10-27

67

Electrical diesel particulate filter (DPF) regeneration  

SciTech Connect

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.

Gonze, Eugene V; Ament, Frank

2013-12-31

68

Hydrocarbon-enhanced particulate filter regeneration via microwave ignition  

SciTech Connect

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

Gonze, Eugene V. (Pinckney, MI); Brown, David B. (Brighton, MI)

2010-02-02

69

Particulate Matter (Environmental Health Student Portal)  

MedlinePLUS

... Waterborne Diseases & Illnesses Water Cycle Water Treatment Particulate Matter The Basics We’ve all seen dirty bathrooms ... the spring. These are visible sources of particulate matter, or PM for short. Show more PM is ...

70

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 ...

71

Source Testing for Particulate Matter.  

ERIC Educational Resources Information Center

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

DeVorkin, Howard

72

Monitoring of particulate matter outdoors  

Microsoft Academic Search

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

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

2002-01-01

73

Fluid&ParticulateSystems 424514/2010  

E-print Network

For solving mathematical problems in chemical engineering Fluid&ParticulateSystems 424514/2010 Fluid Ron Zevenhoven �A Thermal and Flow Engineering ron.zevenhoven@abo.fi 1Fluid&ParticulateSystems 424514/2010 Fluid&ParticulateSystems �A424514/2014 Fluid mechanics ­ re-wrap of basic principles januari 2014 �bo

Zevenhoven, Ron

74

Interactions of detrital particulates and plankton  

Microsoft Academic Search

Detrital particulates, i.e. inorganic and non-living organic material of colloidal size and larger, span ten orders of magnitude in size and are ubiquitous in inland waters. Interactions between plankton and detrital particulates are reciprocal. Release of dissolved organics by living organisms enter the particulate size fraction by flocculation on bubbles or adsorption to inorganic particles. Bacteria benefit from attachment to

John M. Melack

1985-01-01

75

Improved particulate-sampling filter  

NASA Technical Reports Server (NTRS)

Small surface indentations entrain larger and more representative sampling than conventional petri-dish smeared with smooth layer adhesive. Filter is assembled from perforated disk and flat backing plate with sticky surface. Due to design-created currents, particulates come in contact with surface for longer time and have greater probability of being trapped. Filter is useful in air-quality monitoring at industrial sites, in mines, and in and around nuclear power plants.

Hoffman, A. R.; Schneider, H. W.

1980-01-01

76

Quasicrystalline particulate reinforced aluminum composite  

SciTech Connect

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.

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

1997-07-01

77

Proceedings: Eighth particulate control symposium  

SciTech Connect

The Eighth Symposium on the Transfer and Utilization of Particulate Control Technology was held in San Diego, California, March 20 through 23, 1990. The symposium proceedings contain 80 papers presented by representatives of utility companies, equipment and process suppliers, university representatives, research and development companies, EPA and other federal and state agency representatives, and EPRI staff members. Papers from this conference are organized by session in two volumes as follows: Volume 1 contains papers presented in the sessions on: precipitator controls, innovative pollution control technologies, precipitator modeling, fly ash/ESP studies, ESP plate spacing, ESP rapping, ESP performance upgrading and hot-side precipitator studies. Except for papers on corona destruction of pollutants in the innovative pollution control technology sessions, these papers are all concerned with ESP technology. Volume 2 contains papers presented in the sessions on: low ratio baghouse O M experience, pulse-jet baghouse experience, particulate control for AFBCs, particulate control for dry SO{sub 2} control processes, baghouse design and performance, fundamental baghouse studies, high temperature filtration, and control of emissions from RDF incinerators. Individual projects are processed separately for the data bases.

Not Available

1990-11-01

78

Particulate emissions from gas turbine engines. Revision  

SciTech Connect

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.

Not Available

1992-02-01

79

Fluid&ParticulateSystems 424514/2010  

E-print Network

liquid ­ solid Three phase flow: Gas-liquid-solid (trickled bed) or G/S or L/S with many size fractions&ParticulateSystems 424514/2010 Fluid&ParticulateSystems �A424514/2012 Vertical two-phase (G/L) flows RoNz 5 Upward Patterns&ParticulateSystems �A424514/2012 Vertical two-phase (G/L) flows RoNz 6 Downward Patterns depend on relative velocities

Zevenhoven, Ron

80

Diesel particulate filter with zoned resistive heater  

SciTech Connect

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.

Gonze, Eugene V [Pinckney, MI

2011-03-08

81

Spatial and temporal distributions of particulate matter and particulate organic carbon, Northeast Gulf of Mexico  

E-print Network

The distribution of particulate matter (PM) and particulate organic carbon (POC) was determined during the Northeast Gulf of Mexico Chemical Oceanography and Hydro-graphy program (NEGOM). The hydrography and physical forcing functions were examined...

Bernal, Christina Estefana

2012-06-07

82

Methods of separating particulate residue streams  

DOEpatents

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.

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

83

Measurement of Particulate Pollutants in the Atmosphere  

NASA Technical Reports Server (NTRS)

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.

Ckuan, Raymond L.

1971-01-01

84

Electrically heated particulate filter using catalyst striping  

DOEpatents

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.

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

2013-07-16

85

Powder and particulate production of metallic alloys  

NASA Technical Reports Server (NTRS)

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

Grant, N. J.

1982-01-01

86

Combustor for fine particulate coal  

DOEpatents

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.

Carlson, Larry W. (Oswego, IL)

1988-01-01

87

Combustor for fine particulate coal  

DOEpatents

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.

Carlson, L.W.

1988-11-08

88

Combustor for fine particulate coal  

DOEpatents

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.

Carlson, L.W.

1988-01-26

89

Airborne particulate matter in spacecraft  

NASA Technical Reports Server (NTRS)

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

1988-01-01

90

40 CFR 52.1476 - Control strategy: Particulate matter.  

Code of Federal Regulations, 2012 CFR

...false Control strategy: Particulate matter. 52.1476 Section 52.1476 Protection...1476 Control strategy: Particulate matter. (a) The requirements of subpart...the national standards for particulate matter in the Northwest Nevada and Nevada...

2012-07-01

91

40 CFR 266.105 - Standards to control particulate matter.  

Code of Federal Regulations, 2012 CFR

...false Standards to control particulate matter. 266.105 Section 266.105 Protection...105 Standards to control particulate matter. (a) A boiler or industrial furnace...hazardous waste may not emit particulate matter in excess of 180 milligrams per...

2012-07-01

92

40 CFR 52.275 - Particulate matter control.  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 false Particulate matter control. 52.275 Section 52.275... California § 52.275 Particulate matter control. (a) The following rules...because they control emissions of particulate matter, and because there is no...

2013-07-01

93

40 CFR 52.275 - Particulate matter control.  

Code of Federal Regulations, 2012 CFR

... 2012-07-01 false Particulate matter control. 52.275 Section 52.275... California § 52.275 Particulate matter control. (a) The following rules...because they control emissions of particulate matter, and because there is no...

2012-07-01

94

40 CFR 52.1476 - Control strategy: Particulate matter.  

Code of Federal Regulations, 2013 CFR

...false Control strategy: Particulate matter. 52.1476 Section 52.1476 Protection...1476 Control strategy: Particulate matter. (a) The requirements of subpart...the national standards for particulate matter in the Northwest Nevada and Nevada...

2013-07-01

95

40 CFR 52.275 - Particulate matter control.  

Code of Federal Regulations, 2011 CFR

... 2011-07-01 false Particulate matter control. 52.275 Section 52.275... California § 52.275 Particulate matter control. (a) The following rules...because they control emissions of particulate matter, and because there is no...

2011-07-01

96

40 CFR 52.1476 - Control strategy: Particulate matter.  

Code of Federal Regulations, 2011 CFR

...false Control strategy: Particulate matter. 52.1476 Section 52.1476 Protection...1476 Control strategy: Particulate matter. (a) The requirements of subpart...the national standards for particulate matter in the Northwest Nevada and Nevada...

2011-07-01

97

40 CFR 266.105 - Standards to control particulate matter.  

Code of Federal Regulations, 2011 CFR

...false Standards to control particulate matter. 266.105 Section 266.105 Protection...105 Standards to control particulate matter. (a) A boiler or industrial furnace...hazardous waste may not emit particulate matter in excess of 180 milligrams per...

2011-07-01

98

40 CFR 52.275 - Particulate matter control.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Particulate matter control. 52.275 Section 52.275... California § 52.275 Particulate matter control. (a) The following rules...because they control emissions of particulate matter, and because there is no...

2010-07-01

99

40 CFR 52.1476 - Control strategy: Particulate matter.  

Code of Federal Regulations, 2010 CFR

...false Control strategy: Particulate matter. 52.1476 Section 52.1476 Protection...1476 Control strategy: Particulate matter. (a) The requirements of subpart...the national standards for particulate matter in the Northwest Nevada and Nevada...

2010-07-01

100

40 CFR 52.427 - Control strategy: Particulate matter.  

...false Control strategy: Particulate matter. 52.427 Section 52.427 Protection...427 Control strategy: Particulate matter. (a) Determination of attainment...Philadelphia-Wilmington, PA-NJ-DE fine particulate matter (PM2.5 ) nonattainment area has...

2014-07-01

101

40 CFR 52.2059 - Control strategy: Particulate matter.  

...false Control strategy: Particulate matter. 52.2059 Section 52.2059 Protection...2059 Control strategy: Particulate matter. (a) [Reserved] (b) EPA...Philadelphia-Wilmington, PA-NJ-DE fine particulate matter (PM2.5 ) nonattainment area has...

2014-07-01

102

40 CFR 52.275 - Particulate matter control.  

... 2014-07-01 false Particulate matter control. 52.275 Section 52.275... California § 52.275 Particulate matter control. (a) The following rules...because they control emissions of particulate matter, and because there is no...

2014-07-01

103

MONITORING AIRBORNE PARTICULATE MASS BY BETA ABSORPTION  

EPA Science Inventory

A prototype airborne particulate mass monitor, using the principle of beta radiation absorption, has been fabricated and evaluated on airborne particulate matter. A detection sensitivity of 80 microgram/sq cm was attained. A series of samples were collected, and a comparison was ...

104

Testing Students' Use of the Particulate Theory  

ERIC Educational Resources Information Center

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

Williamson, Vickie; Huffman, Jason; Peck, Larry

2004-01-01

105

Neutron-depolarization theory in particulate media  

Microsoft Academic Search

Neutron-depolarization (ND) theory in particulate media is discussed. The relations between the correlation matrix omega, derived from a neutron-depolarization experiment, and parameters describing the micromagnetic state of a particulate medium are derived and discussed extensively. The latter involves the individual particles, magnetic interparticle correlations as a result of particle interactions or particle orientational correlations, density variations within the medium, and

R. Rosman; M. Th. Rekveldt

1991-01-01

106

Strain behavior of magnetostrictive particulate composites  

Microsoft Academic Search

A new theory is presented of the nonlinear magneto-elastic behavior of magnetically dilute magnetostrictive particulate composites. The theory assumes a uniform external magnetic field is operating on a large number of well distributed, crystallographically and shape parallel ellipsoidal magnetostrictive particles encased in an elastic, nonmagnetic composite matrix. The aspect ratio of the particulates may vary between 1 to infinity and

William D. Armstrong

1999-01-01

107

Air Quality Criteria for Particulate Matter.  

ERIC Educational Resources Information Center

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

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

108

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...

109

Simulation and evaluation of aseptic particulate processing  

Microsoft Academic Search

Two phases of research were conducted in an attempt to solve the problems associated with aseptic particulate processing. The first phase of research focused on developing a thermal processing indicator that can be used to monitor particle lethality in a continuous system. The second phase of research involved experimental and computer simulation studies of a simultaneous steam-microwave particulate processing system.^

David Scott Lineback

1994-01-01

110

Advanced particulate matter control apparatus and methods  

DOEpatents

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.

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

2012-01-10

111

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...

112

Electrically heated particulate filter propagation support methods and systems  

SciTech Connect

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.

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

2011-06-07

113

REVIEW OF DIESEL PARTICULATE MATTER SAMPLING METHODS Supplemental Report # 1  

E-print Network

REVIEW OF DIESEL PARTICULATE MATTER SAMPLING METHODS Supplemental Report # 1 DIESEL EXHAUST for the Environmental Protection Agency (EPA) grant titled "Review of Diesel Particulate Matter Sampling Methods

Minnesota, University of

114

Hypocoordinated solids in particulate media  

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

115

Radiant zone heated particulate filter  

SciTech Connect

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

Gonze, Eugene V [Pinckney, MI

2011-12-27

116

Electrically heated particulate filter enhanced ignition strategy  

SciTech Connect

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

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

2012-10-23

117

Particulate contamination spectrometer. Volume 1: Technical report  

NASA Technical Reports Server (NTRS)

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.

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

1975-01-01

118

PARTICULATE DATA REDUCTION SYSTEM (PADRE) USER GUIDE  

EPA Science Inventory

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

119

OPEN PATH OPTICAL SENSING OF PARTICULATE MATTER  

EPA Science Inventory

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

120

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...

121

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...

122

An improved visualization of diesel particulate filter/  

E-print Network

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 ...

Boehm, Kevin (Kevin W.)

2011-01-01

123

PARTICULATE SAMPLING SUPPORT: 1977 ANNUAL REPORT  

EPA Science Inventory

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

124

Differential Spectroscopic Imaging of Particulate Explosives Residue  

SciTech Connect

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.

Bernacki, Bruce E.; Ho, Nicolas

2008-04-01

125

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...

126

The Particulate Air Pollution Controversy  

PubMed Central

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

Phalen, Robert F.

2004-01-01

127

Airborne Particulates over Southern Africa  

NASA Technical Reports Server (NTRS)

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.

2001-01-01

128

Particulate matter in the Venus atmosphere  

NASA Technical Reports Server (NTRS)

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

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

1985-01-01

129

Fluid&ParticulateSystems 424514/2010  

E-print Network

/2014 Pressure rise by water hammer E d w p 0 0w d E velocity of the liquid before of the water mass in the of tube: F = m·a = p/L januari 2014 RoNz 6�bo Akademi University - Värme- och umd dt dw wAl 4.2 7 Fluid&ParticulateSystems 424514/2010 Fluid&ParticulateSystems �A424514

Zevenhoven, Ron

130

Fluid&ParticulateSystems 424514/2010  

E-print Network

Finland februari 2014 Unit w: kg/m2 Fluid&ParticulateSystems 424514/2010 Fluid&ParticulateSystems �A424514) * ** * * * * tV p R V p f dt dV u fluidfluid )()(2 2 RoNz 6�bo Akademi University - Värme- och radius R (m), length L (m), submerged angle (0 ... 2) : volume element A = R L is submerged

Zevenhoven, Ron

131

Quantitative microanalysis of individual particulates. I. Electron probe microanalysis of NBS-glass particulates  

Microsoft Academic Search

The applicability of the Monte Carlo calculation technique for quantitative analysis of particulate samples with an electron probe microanalyzer was verified through comparison between theoretical and experimental results for an NBS K-411 series of glass particulates. Good agreement between theory and experiment suggests that the Monte Carlo calculation technique will be a useful tool for performing quantitative electron probe microanalysis

Kenichi Obori; Ryuichi Shimizu; Takahiko Oura; Shingo Ichimura

1983-01-01

132

Advanced Hybrid Particulate Collector Project Management Plan  

SciTech Connect

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

Miller, S.J.

1995-11-01

133

Comparison of particulate verification techniques study  

NASA Astrophysics Data System (ADS)

The efficacy of five particulate verification techniques on four types of materials was studied. Statistical Analysis Software/JMP 6.0 was used to create a statistically valid design of experiments. In doing so, 35 witness coupons consisting of the four types of materials being studied, were intentionally contaminated with particulate fallout. Image Analysis was used to characterize the extent of particulate fallout on the coupons and was used to establish a baseline, or basis of comparison, against the five techniques that were studied. The five particulate verification techniques were the Tapelift, the Particulate Solvent Rinse, the GelPak lift, an in-line vacuum filtration probe, and the Infinity Focusing Microscope (IFM). The four types of materials consisted of magnesium flouride (MgF II) coated mirrors, composite coated silver aluminum (CCAg), Z93 and NS43G coated aluminum, and silicon (si) wafers. The vacuum probe was determined to be most effective for Z93, the tapelift or vacuum probe for MgF2, and the GelPak Lift for CCAg and si substrates. A margin of error for each technique, based on experimental data from two experiments, for si wafer substrates, yielded the following: Tapelift - 67%, Solvent Rinse - 58%, GelPak- 26%, Vacuum Probe - 93%, IFM-to be determined.

Rivera, Rachel

2006-08-01

134

Method for dispersing catalyst onto particulate material  

DOEpatents

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.

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

1992-01-01

135

Particulate hot gas stream cleanup technical issues  

SciTech Connect

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.

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

1999-09-30

136

[Suspended particulates and lung health].  

PubMed

Based on several severe air pollution episodes, a temporal correlation between high concentrations of particulate matter (PM) and SO2 pollution and acute increases in respiratory and cardiopulmonary mortality had been established in Vienna for the 1970's. After air pollution had decreased in Austria in the 1980's--as documented by data on SO2, and total suspended particles (TSP)--no such associations between day-to-day changes of SO2 and TSP and mortality have been documented any more, however, traffic related pollutants like fine particles and NO2 remained a problem. Therefore, short term effects of PM on lung function, morbidity and mortality were investigated in Vienna, Linz, Graz and a rural control area. Long-term exposure and chronic disease--even more important for public health--were studied in repeated cross-sectional, a mixed longitudinal and a birth cohort study on school children in the city of Linz. Lung function growth was found impaired from long-term exposure to air pollutants and improved in districts where ambient air pollution had decreased. Where only TSP and SO2 had decreased, no continuous improvement of small airway function was found and end-expiratory flow rates stayed impaired where NO2-reduction from technical improvements of cars and industry was counterbalanced by increase of motorized (diesel) traffic. Remaining acute effects of ambient air pollution in 2001 from PM, NO2 and co-pollutants found in a time series study also show that continuing efforts are necessary. Active surface of particles inhaled several hours to days before spirometry was found related to short-term reductions in forced vital capacity-FVC (p<0.01), forced expiratory volume in one second-FEV1 (p<0.01) and maximal expiratory flow rate at 50% of vital capacity-MEF50 (p<0.05). In pupils with asthma or previous airway obstruction 4-week-diaries proved that the following symptoms increased with acute exposure to higher active surface of particles: wheezing (p<0.01), dyspnea, cough when going to sleep, cough at night (p<0.05). Efforts to reduce exposure to fine particles from motor traffic and passive smoking have to be increased if we want to achieve full recovery of children from air pollution effects and best respiratory performance in adulthood. Surveillance seems to be necessary not only for particle mass but also for particle number and surface. Little is known on the mechanisms of irreversible long-term effects of PM such as myocardial infarction and cancer. In a prospective cohort study on 1630 dust-exposed and 1630 non dust-exposed workers matched for smoking we found an increase of lung cancer related to nonfibrous insoluble PM. Other studies were able to relate lung cancer to specific particles like those from diesel engines, and a large prospective study of the American Cancer Society was able to link lung cancer in the general population with long-term exposure to fine particles from combustion processes. All these recent epidemiological findings will have consequences for occupational and ambient air PM standards. PMID:15518085

Neuberger, Manfred; Moshammer, Hanns

2004-01-01

137

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...

138

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...

139

CHARACTERIZATION OF PARTICULATE EMISSIONS FROM NON-FERROUS SMELTERS  

EPA Science Inventory

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

140

40 CFR 52.1025 - Control strategy: Particulate matter.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Control strategy: Particulate matter. 52.1025...CONTINUED) Maine § 52.1025 Control strategy: Particulate matter. (a) The revisions to the control strategy resulting from the...

2011-07-01

141

40 CFR 52.2059 - Control strategy: Particulate matter.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Control strategy: Particulate matter. 52.2059 ...Pennsylvania § 52.2059 Control strategy: Particulate matter. (a...June 1, 1980. Analysis and control strategy development: 1. Analyze...

2011-07-01

142

40 CFR 52.1341 - Control strategy: particulate matter.  

Code of Federal Regulations, 2011 CFR

...Environment 4 2011-07-01 2011-07-01 false Control strategy: particulate matter. 52.1341 Section 52.1341 Protection...IMPLEMENTATION PLANS (CONTINUED) Missouri § 52.1341 Control strategy: particulate matter. Determination of Attainment....

2011-07-01

143

40 CFR 52.477 - Control strategy: Particulate matter.  

Code of Federal Regulations, 2011 CFR

...Environment 3 2011-07-01 2011-07-01 false Control strategy: Particulate matter. 52.477 Section 52.477 Protection...IMPLEMENTATION PLANS District of Columbia § 52.477 Control strategy: Particulate matter. Determination of...

2011-07-01

144

EXPOSURE ASSESSMENT OF OLDER ADULTS TO PARTICULATE MATTER  

EPA Science Inventory

The factors that influence the amount of particulate matter that potentially susceptible elderly Americans are exposed to is an issue of concern. This presentation and abstract investigates these factors using data obtained from three longitudinal particulate matter panel studies...

145

75 FR 17865 - Approval and Promulgation of Air Quality Implementation Plans; Wisconsin; Particulate Matter...  

Federal Register 2010, 2011, 2012, 2013

...Implementation Plans; Wisconsin; Particulate Matter Standards AGENCY: Environmental Protection...The updates were made to the particulate matter standards by adding fine particulate standards...standards. EPA revised its particulate matter standards in October 2006 by...

2010-04-08

146

Uraninite and Fullerene in Atmospheric Particulates  

E-print Network

Research Uraninite and Fullerene in Atmospheric Particulates S A T O S H I U T S U N O M I Y A , K in carbonaceous matter (e50 nm) similar to fullerene. We have also identified, for the first time, closely. In this study, we have completed mass spectrometry analysis to detect the presence of fullerene and also

Utsunomiya, Satoshi

147

Indoor particulate reactive oxygen species concentrations.  

PubMed

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

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

2014-07-01

148

Instrumentation for diesel particulate matter emissions research  

Microsoft Academic Search

Measurement and sampling of diesel particulate matter in mine air presents a challenge due to the complexity of the diesel aerosol. The results of a series of tests carried out by the National Institute for Occupation Safety and Health, Pittsburgh Research Laboratory, in an underground mine were used to evaluate severalmeasurementmethodsthatarecurrentlyusedtocharacterizeparticulatematteremittedbydiesel-powered equipment. This paper presents an overview of these techniques

S. E. Mischler; A. D. Bugarski; J. D. Noll

149

EVALUATIONS OF NOVEL PARTICULATE CONTROL DEVICES  

EPA Science Inventory

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

150

Behavior of particulates in thermal plasma flows  

Microsoft Academic Search

Injection of particulate matter into a thermal plasma represents one of the approaches used in thermal plasma processing. The injected particles are usually treated as a dispersed phase, governed by the equation of motion and the rate equations for heat and mass transfer in Lagrangian coordinates. A stochastic approach is introduced to take particle dispersion into account due to turbulent

Y. P. Chyou; E. Pfender

1989-01-01

151

Effective thermal conductivity estimates of particulate mixtures  

Microsoft Academic Search

Several theories have been advanced to estimate effective thermal conductivities of particulate mixtures, but most theories have focused on the dilute case. A method is proposed to estimate the effective thermal conductivity coefficient of mixtures of arbitrary concentration. Earlier the authors developed a theory to determine the expected contact area between different species. This theory is employed to determine the

Christiaan Richter; Hendrik J. Viljoen; N. F. J. van Rensburg

2003-01-01

152

Fluid&ParticulateSystems 424514/2010  

E-print Network

" Ron Zevenhoven �A Thermal and Flow Engineering ron.zevenhoven@abo.fi 9Fluid&ParticulateSystems 424514 kinetics ­ Inclusion ("occlusion") of impurities, or crystal water ­ Process control temperature crystal-20500 �bo / Turku Finland RoNz 5 Overview /3 - types Solution crystallisation (the main subject here

Zevenhoven, Ron

153

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...

154

FOREIGN AIR POLLUTION RESEARCH IN FINE PARTICULATES  

EPA Science Inventory

The report presents unpublished fine particulate measurement and control information and information not readily available to the researcher, generated during the period 1971-76 in Australia, Canada, Japan, and the USSR. The information is used as a basis for identifying new conc...

155

HIGH TEMPERATURE PARTICULATE CONTROL WITH CERAMIC FILTERS  

EPA Science Inventory

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

156

Roadside measurements of particulate matter size distribution  

Microsoft Academic Search

Roadside measurements were performed in order to document the size distribution of particulate matter (PM) under dilution conditions similar to those found in real world. These activities covered measurements at engine test beds, at different locations in a road tunnel as well as in an urban environment. In order to get a clear picture of the evolution of the PM

Peter J. Sturm; Urs Baltensperger; Michael Bacher; Bernhard Lechner; Stefan Hausberger; Bernhard Heiden; David Imhof; Ernest Weingartner; Andre S. H. Prevot; Ralf Kurtenbach; Peter Wiesen

2003-01-01

157

Control Techniques for Particulate Air Pollutants.  

ERIC Educational Resources Information Center

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…

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

158

STUDIES OF PARTICULATE REMOVAL FROM DIESEL EXHAUST  

EPA Science Inventory

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

159

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...

160

Catalytic traps for diesel particulate control  

Microsoft Academic Search

The first stages of the development of a catalytic trap for diesel particulate removal from vehicle exhaust gases are addressed, ranging from catalytic trap preparation (a ceramic foam is deposited with catalysts, suitable for soot combustion, based on mixtures of KCl and different vanadates) to catalytic trap testing in a specific pilot plant (an acetylene burner is used to produce

Guido Saracco; Claudio Badini; Vito Specchia

1999-01-01

161

FINE PARTICULATE MATTER EMISSIONS FROM CANDLES  

EPA Science Inventory

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

162

Characterization of exhaust particulates from diesel engine  

NASA Astrophysics Data System (ADS)

This study was set out to characterize particulate emissions from a mid-sized diesel engine in terms of metals, benzene soluble fraction, elemental and organic carbon. For this study, the exhaust particulates from Mahindra direct injection transportation diesel engine (40 hp) were collected at four different engine operating conditions, namely idle, 40%, 70% and full load for the above parameters. It was found that as the load increased from idling to full load, the metal content in particulates gradually decreased. The metal content in exhaust particulates was correlated with that of metal content in diesel. Benzene soluble fraction, which is a marker for carcinogenicity, also showed decrease in its level with increasing load. It was found that at idling, 67% of mass was soluble in benzene while at full load it was only about 24%. Elemental carbon content increased with increase in load showing a maximum of 48% at 70% load and a minimum of 25% at idling. The trend of organic carbon was quite opposite; it showed 35% organic carbon at idling, which decreased gradually with increase in load. This research has suggested that composition of diesel exhaust particles varies significantly with varying engine load conditions.

Sharma, Mukesh; Agarwal, Avinash Kumar; Bharathi, K. V. L.

163

PARTICULATE MATTER RESEARCH Plan (Draft, 2004)  

EPA Science Inventory

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

164

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

E-print Network

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 ...

Beauboeuf, Daniel P

2010-01-01

165

40 CFR 60.292 - Standards for particulate matter.  

Code of Federal Regulations, 2013 CFR

...with gaseous and liquid fuels, particulate matter at emission rates exceeding STD as specified by the following equation: STD=X [1.3(Y)+(Z)] Where: STD=Particulate matter emission limit, g of particulate/kg (lb of...

2013-07-01

166

Comments on the Criteria Document for Particulate Matter Air Pollution  

E-print Network

on particulate matter air pollution. The document, called Air Quality Criteria for Particulate Matter, is the first step in the process of setting air quality standards in the United States. Once the criteriaComments on the Criteria Document for Particulate Matter Air Pollution Richard Smith Peter Guttorp

Washington at Seattle, University of

167

40 CFR 60.102 - Standard for particulate matter.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Standard for particulate matter. 60.102 Section 60.102 Protection... § 60.102 Standard for particulate matter. Each owner or operator of...catalyst regenerator: (1) Particulate matter in excess of 1.0 kg/Mg (2.0...

2012-07-01

168

40 CFR 60.142 - Standard for particulate matter.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Standard for particulate matter. 60.142 Section 60.142 Protection... § 60.142 Standard for particulate matter. (a) Except as provided under...gases which: (1) Contain particulate matter in excess of 50 mg/dscm (0.022...

2013-07-01

169

40 CFR 60.282 - Standard for particulate matter.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Standard for particulate matter. 60.282 Section 60.282 Protection... § 60.282 Standard for particulate matter. (a) On and after the date on...gases which: (i) Contain particulate matter in excess of 0.10 g/dscm...

2013-07-01

170

40 CFR 60.102 - Standard for particulate matter.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Standard for particulate matter. 60.102 Section 60.102 Protection... § 60.102 Standard for particulate matter. Each owner or operator of...catalyst regenerator: (1) Particulate matter in excess of 1.0 kg/Mg (2.0...

2013-07-01

171

40 CFR 60.532 - Standards for particulate matter.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Standards for particulate matter. 60.532 Section 60.532 Protection...60.532 Standards for particulate matter. Unless exempted under § 60.530...shall comply with the following particulate matter emission limits as determined by the...

2013-07-01

172

40 CFR 60.282 - Standard for particulate matter.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Standard for particulate matter. 60.282 Section 60.282 Protection... § 60.282 Standard for particulate matter. (a) On and after the date on...gases which: (i) Contain particulate matter in excess of 0.10 g/dscm...

2012-07-01

173

40 CFR 60.262 - Standard for particulate matter.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Standard for particulate matter. 60.262 Section 60.262 Protection... § 60.262 Standard for particulate matter. (a) On and after the date on...control device and contain particulate matter in excess of 0.45 kg/MW-hr...

2013-07-01

174

40 CFR 60.472 - Standards for particulate matter.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Standards for particulate matter. 60.472 Section 60.472 Protection...60.472 Standards for particulate matter. (a) On and after the date on...from any saturator: (1) Particulate matter in excess of: (i) 0.04...

2013-07-01

175

40 CFR 60.142 - Standard for particulate matter.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Standard for particulate matter. 60.142 Section 60.142 Protection... § 60.142 Standard for particulate matter. (a) Except as provided under...gases which: (1) Contain particulate matter in excess of 50 mg/dscm (0.022...

2012-07-01

176

40 CFR 60.532 - Standards for particulate matter.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Standards for particulate matter. 60.532 Section 60.532 Protection...60.532 Standards for particulate matter. Unless exempted under § 60.530...shall comply with the following particulate matter emission limits as determined by the...

2012-07-01

177

40 CFR 60.472 - Standards for particulate matter.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Standards for particulate matter. 60.472 Section 60.472 Protection...60.472 Standards for particulate matter. (a) On and after the date on...from any saturator: (1) Particulate matter in excess of: (i) 0.04...

2012-07-01

178

40 CFR 52.725 - Control strategy: Particulates.  

...committal SIP for particulate matter with an aerodynamic diameter equal to or less than 10 micrometers...NAAQS for particulate matter with an aerodynamic diameter less than or equal to a nominal...NAAQS for particulate matter with an aerodynamic diameter less than or equal to a...

2014-07-01

179

40 CFR 52.725 - Control strategy: Particulates.  

Code of Federal Regulations, 2011 CFR

...committal SIP for particulate matter with an aerodynamic diameter equal to or less than 10 micrometers...NAAQS for particulate matter with an aerodynamic diameter less than or equal to a nominal...NAAQS for particulate matter with an aerodynamic diameter less than or equal to a...

2011-07-01

180

40 CFR 52.725 - Control strategy: Particulates.  

Code of Federal Regulations, 2012 CFR

...committal SIP for particulate matter with an aerodynamic diameter equal to or less than 10 micrometers...NAAQS for particulate matter with an aerodynamic diameter less than or equal to a nominal...NAAQS for particulate matter with an aerodynamic diameter less than or equal to a...

2012-07-01

181

40 CFR 52.725 - Control strategy: Particulates.  

Code of Federal Regulations, 2010 CFR

...committal SIP for particulate matter with an aerodynamic diameter equal to or less than 10 micrometers...NAAQS for particulate matter with an aerodynamic diameter less than or equal to a nominal...NAAQS for particulate matter with an aerodynamic diameter less than or equal to a...

2010-07-01

182

40 CFR 52.725 - Control strategy: Particulates.  

Code of Federal Regulations, 2013 CFR

...committal SIP for particulate matter with an aerodynamic diameter equal to or less than 10 micrometers...NAAQS for particulate matter with an aerodynamic diameter less than or equal to a nominal...NAAQS for particulate matter with an aerodynamic diameter less than or equal to a...

2013-07-01

183

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...

184

40 CFR 60.472 - Standards for particulate matter.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Standards for particulate matter. 60.472 Section 60.472 Protection...60.472 Standards for particulate matter. (a) On and after the date on...from any saturator: (1) Particulate matter in excess of: (i) 0.04...

2011-07-01

185

40 CFR 60.532 - Standards for particulate matter.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Standards for particulate matter. 60.532 Section 60.532 Protection...60.532 Standards for particulate matter. Unless exempted under § 60.530...shall comply with the following particulate matter emission limits as determined by the...

2010-07-01

186

40 CFR 60.102 - Standard for particulate matter.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Standard for particulate matter. 60.102 Section 60.102 Protection... § 60.102 Standard for particulate matter. Each owner or operator of...catalyst regenerator: (1) Particulate matter in excess of 1.0 kg/Mg (2.0...

2011-07-01

187

40 CFR 60.532 - Standards for particulate matter.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Standards for particulate matter. 60.532 Section 60.532 Protection...60.532 Standards for particulate matter. Unless exempted under § 60.530...shall comply with the following particulate matter emission limits as determined by the...

2011-07-01

188

40 CFR 60.472 - Standards for particulate matter.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Standards for particulate matter. 60.472 Section 60.472 Protection...60.472 Standards for particulate matter. (a) On and after the date on...from any saturator: (1) Particulate matter in excess of: (i) 0.04...

2010-07-01

189

Electrically heated particulate filter preparation methods and systems  

DOEpatents

A control system that controls regeneration of a particulate filter is provided. The system generally includes a fuel control module that controls injection of fuel into exhaust that passes through the particulate filter. A regeneration module controls current to the particulate filter to initiate regeneration after the fuel has been injected into the exhaust.

Gonze, Eugene V [Pinckney, MI

2012-01-31

190

Health Effects of Atmospheric Particulates: A Medical Geology Perspective  

Microsoft Academic Search

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

Nurdan S Duzgoren-Aydin

2008-01-01

191

Thorium-particulate matter interaction. Thorium complexing capacity of oceanic particulate matter: Theory  

Microsoft Academic Search

The interaction between thorium and oceanic particulate matter was examined experimentally by using chemical equilibrium techniques. Thorium reacts quantitatively with the organic binding site of Particulate Matter (PM) in 0.1 mol\\/L HC1 solution by complexation, which is equilibrated within 24 h. According to mass balance analysis, thorium forms a 1:1 complex with the organic binding site in PM, whose conditional

Katsumi Hirose; Eiichiro Tanoue

1994-01-01

192

The relationship between particulate uranium and thorium-complexing capacity of oceanic particulate matter  

Microsoft Academic Search

Thorium-complexing capacity (ThCC), which is defined as the amount of thorium adsorption onto particulate matter (PM) in 0.1 mol l?1 HCl solution by complexation, has been introduced as a new oceanographic parameter. The ThCC implies the concentration of a strong organic ligand in PM. To specify chemically the strong ligand in PM, we compared the ThCC in PM with particulate

Katsumi Hirose

1995-01-01

193

Particulate contaminant relocation during shuttle ascent  

NASA Technical Reports Server (NTRS)

The dislodgement, venting, and redeposition of particles on a surface in the shuttle bay by the vibroacoustic, gravitational, and aerodynamic forces present during shuttle ascent have been investigated. The particles of different sizes which are displaced, vented, and redistributed have been calculated; and an estimate of the increased number of particles on certain surfaces and the decrease on others has been indicated. The average sizes, velocities, and length of time for certain particles to leave the bay following initial shuttle doors opening and thermal tests have been calculated based on indirect data obtained during several shuttle flights. Suggestions for future measurements and observations to characterize the particulate environment and the techniques to limit the in-orbit particulate contamination of surfaces and environment have been offered.

Scialdone, J. J.

1986-01-01

194

Glints from particulate media and wavy surfaces  

NASA Astrophysics Data System (ADS)

Glints are bright light spots created by particulate media like cirrus clouds, glaciers, and wavy water surfaces. They are seen around the specular reflection angle. In this paper, the glints from such scattering/reflecting media are described in a unified manner through the probability density for facet tilts. Various kinds of these probability densities for wavy surfaces are defined and classified. The concept of the differential scattering cross section (DSCS) for rough surfaces instead of the conventional bidirectional reflectance distribution function (BRDF) is introduced for characterization of the glints. The simple equations connecting the DSCS and the probability densities for facet tilts are derived. It is shown that the glints from particulate media and wavy surface are very similar at small incidence angles and they are significantly different at slant incidence.

Borovoi, Anatoli; Konoshonkin, Alexander; Kolokolova, Ludmilla

2012-12-01

195

Atmospheric particulate analysis using angular light scattering  

NASA Technical Reports Server (NTRS)

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.

Hansen, M. Z.

1980-01-01

196

Atmospheric particulate analysis using angular light scattering  

NASA Technical Reports Server (NTRS)

Using 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 for the experimental measurements. This was used as a first guess for a nonlinear iterative inversion of the size distribution. 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.

Hansen, M. Z.

1980-01-01

197

Face crack reduction strategy for particulate filters  

DOEpatents

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.

Gonze, Eugene V [Pinckney, MI

2012-01-31

198

Innovations in high-temperature particulate filtration  

SciTech Connect

Fluidized-bed combustion and coal gasification expose sensitive equipment, such as high-speed turbines, to hot combustion offgases. In order to prevent erosion, corrosion, and other damage to sensitive equipment, such systems now incorporate high-temperature particulate filters. One device often considered for such applications uses a design similar to a baghouse (i.e., multiple banks of porous filter bags that remove particulate from gas streams). In this case, however, instead of polyester or teflon fabric, the filter elements are made of rigid ceramic or similar materials. These devices are sometimes called `candle filters,` and the individual ceramic filter elements are frequently called `candles.` Three high-temperature applications of candle filters are described here. 2 refs., 3 figs.

Lippert, T. [Westinghouse Science & Technology Center, Pittsburgh, PA (United States)

1997-05-01

199

NICKEL SPECIATION OF URBAN PARTICULATE MATTER  

SciTech Connect

A four-step sequential Ni extraction method, summarized in Table AB-1, was evaluated for identifying and quantifying the Ni species occurring in urban total suspended particulate (TSP) matter and fine particulate matter (<10 {micro}m [PM{sub 10}] and <2.5 {micro}m [PM{sub 2.5}] in aerodynamic diameter). The extraction method was originally developed for quantifying soluble, sulfidic, elemental, and oxidic forms of Ni that may occur in industrial atmospheres. X-ray diffraction (XRD) and x-ray absorption fine structure (XAFS) spectroscopy were used to evaluate the Ni species selectivity of the extraction method. Uncertainties in the chemical speciation of Ni in urban PM{sub 10} and PM{sub 2.5} greatly affect inhalation health risk estimates, primarily because of the large variability in acute, chronic, and cancer-causing effects for different Ni compounds.

Kevin C. Galbreath; Charlene R. Crocker; Carolyn M. Nyberg; Frank E. Huggins; Gerald P. Huffman

2003-10-01

200

Self-Cleaning Particulate Prefilter Media  

NASA Technical Reports Server (NTRS)

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.

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

2012-01-01

201

Prediction of particulate contamination on aperture window  

NASA Technical Reports Server (NTRS)

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.

Lee, Aleck L.; Fong, Michael C.

1994-01-01

202

Differential spectroscopic imaging of particulate explosives residue  

NASA Astrophysics Data System (ADS)

We present experimental results showing transmission and reflection imaging of approximately 100 ?g quantities of particulate explosives residue using a commercial uncooled microbolometer infrared camera and CO II laser differential wavelength illumination. Fine particulates may be generated during bomb-making activities and these particulates can tenaciously adhere to packing material, as well as to the clothing or skin of the bomb maker and could be detectable during transportation. A rapid screening method that detects this residue can serve as a first-line screening method in conjunction with more sensitive, but invasive, approaches. Explosives exhibit absorption features in the mid-infrared molecular fingerprint region that spans 3 to 15 ?m, which can be probed with many high-brightness sources such as fixed wavelength and tunable quantum cascade lasers, CO II, CO, and OPO lasers. Commercial uncooled microbolometer cameras typically have detection sensitivity from 7.5 to 13 ?m, spanning an absorption region for explosives detection with adequate signal-to-noise ratio. By illuminating a target on and off its absorption wavelengths, ratio images of suspected residue can be obtained without any sample preparation or cooperation and contact with the target. Our proof-of-principle experiment employed tunable CO II lasers, with a tuning range from 9.2 to 10.6 ?m, overlapping minor absorption features of RDX and Tetryl.

Bernacki, Bruce E.; Hô, Nicolas

2008-04-01

203

Cometary particulate analyzer design definition study  

NASA Technical Reports Server (NTRS)

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.

Utterback, N. G.

1981-01-01

204

HIV infection is associated with increased NTPDase activity that correlates with CD39-positive lymphocytes  

Microsoft Academic Search

Infection with the human immunodeficiency virus (HIV) results in alterations in immune cells such as an increase or decrease of cytokine secretion and immunodeficiency. HIV causes a state of chronic cellular activation that can induce apoptosis in lymphocyte T-helpers, making the patient susceptive to opportunistic infections. The biochemical mechanisms involved in this immune response to HIV have been researched. Here,

Daniela B. R. Leal; Cristiane A. Streher; Claudia de M. Bertoncheli; Luiz F. D. Carli; Claudio A. M. Leal; José E. P. da Silva; Vera M. Morsch; Maria R. C. Schetinger

2005-01-01

205

CD39\\/Ectonucleoside Triphosphate Diphosphohydrolase 1 Provides Myocardial Protection During Cardiac Ischemia\\/Reperfusion Injury  

Microsoft Academic Search

Background—Extracellular adenosine, generated from extracellular nucleotides via ectonucleotidases, binds to specific receptors and provides cardioprotection from ischemia and reperfusion. In the present study, we studied ecto-enzymatic ATP\\/ADP-phosphohydrolysis by select members of the ectonucleoside triphosphate diphosphohydrolase (E-NTPDase) family during myocardial ischemia. Methods and Results—As a first step, we used a murine model of myocardial ischemia and in situ preconditioning and performed

David Köhler; Tobias Eckle; Marion Faigle; Almut Grenz; Michel Mittelbronn; Stefanie Laucher; Melanie L. Hart; Simon C. Robson; Christa E. Müller; Holger K. Eltzschig

2010-01-01

206

Methods and apparatus for handling or treating particulate material  

NASA Technical Reports Server (NTRS)

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.

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

2009-01-01

207

Mechanical Properties of Particulate Reinforced Aluminium Alloy Matrix Composite  

Microsoft Academic Search

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

M. Sayuti; S. Sulaiman; B. T. H. T. Baharudin; M. K. A. Arifin; S. Suraya; T. R. Vijayaram

2011-01-01

208

X-Ray Absorption Characterization of Diesel Exhaust Particulates  

SciTech Connect

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.

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

1999-11-18

209

Diesel particulate filter regeneration via resistive surface heating  

DOEpatents

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.

Gonze, Eugene V; Ament, Frank

2013-10-08

210

Shielded regeneration heating element for a particulate filter  

SciTech Connect

An exhaust system includes a particulate filter (PF) that is disposed downstream from an engine. The PF filters particulates within an exhaust from the engine. A heating element heats particulate matter in the PF. A catalyst substrate or a flow converter is disposed upstream from said heating element. The catalyst substrate oxidizes the exhaust prior to reception by the heating element. The flow converter converts turbulent exhaust flow to laminar exhaust flow prior to reception by the heating element.

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

2011-01-04

211

Effects of Particulate and Gaseous Air Pollution on Cardiorespiratory Hospitalizations  

Microsoft Academic Search

We obtained data on daily numbers of admissions to hospital in Toronto, Canada, from 1980 to 1994 for respiratory, cardiac, cerebral vascular, and peripheral vascular diseases. We then linked the data to daily measures of particulate mass less than 10 microns in aerodynamic diameter (PM10), particulate mass less than 2.5 microns in aerodynamic diameter (PM2.5), and particulate mass between 2.5

Richard T. Burnett; Marc Smith-doiron; Dave Stieb; Sabit Cakmak; Jeffrey R. Brook

1999-01-01

212

Occupational Medicine Implications of Engineered Nanoscale Particulate Matter  

E-print Network

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

Kelly, Richard J.

2008-01-01

213

Electrically heated particulate filter regeneration using hydrocarbon adsorbents  

SciTech Connect

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.

Gonze, Eugene V [Pinckney, MI

2011-02-01

214

Remote sensing of particulate concentrations in water  

NASA Technical Reports Server (NTRS)

Determination of residual radiance is essential in remote sensing measurements of suspended solids in the absence of real-time ground-truth data. Some typical background corrections are presented for Lake Superior and the spectral distribution of the residual radiance is determined from three major categories of turbidity in the lake. The results tested with Landsat 2 digital tape data indicate that for large bodies of water general information on atmospheric scattering, water clarity, and optical properties of suspended solids enables one to estimate the concentrations of particulates to within + or - 0.5 mg/liter in the absence of real-time ground-truth data.

Sydor, M.

1980-01-01

215

Electrically heated particulate filter with reduced stress  

DOEpatents

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.

Gonze, Eugene V.

2013-03-05

216

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...

217

The Effect of Viewing Order of Macroscopic and Particulate Visualizations on Students' Particulate Explanations  

ERIC Educational Resources Information Center

A prior study showed that students best make predictions about the outcome of opening a valve between two flasks containing a fluid or vacuum when they view both a demonstration video and a particulate animation, but the study showed no influence from the order in which these visualizations were used. The purpose of this current research was to…

Williamson, Vickie M.; Lane, Sarah M.; Gilbreath, Travis; Tasker, Roy; Ashkenazi, Guy; Williamson, Kenneth C.; Macfarlane, Ronald D.

2012-01-01

218

Exhaust gas filter apparatus capable of regeneration of a particulate filter and method  

SciTech Connect

An exhaust gas filter apparatus includes a particulate filter for collecting a particulate from an exhaust gas. The exhaust gas filter also includes a electromagnetic radiation resonator to heat a portion of the particulate to ignite the particulate and regenerate the particulate filter.

Phelps, Amanda C [Malibu, CA; Kirby, Kevin W [Calabasas Hills, CA; Gregoire, Daniel [Thousand Oaks, CA

2009-04-07

219

Jammed particulate systems are inherently nonharmonic  

NASA Astrophysics Data System (ADS)

Normal mode analysis in the harmonic approximation underlies most of solid-state physics and applies well to both ordered and dis- ordered systems. Naturally, researches apply this analysis to jammed particulate systems, such as granular media, colloids, and foams, that interact via one-sided interactions, which are nonzero only when particles overlap. However, we find that systems with one-sided repulsive interactions possess no linear, harmonic response regime for large systems (N->?) at finite pressures P, and for all N near jamming onset P->0. We perform simulations on 2D frictionless bidisperse mechanically stable disk packings over a range of packing fractions ??= ?-?J above jamming onset ?J. We apply perturbations with amplitude ? to the packings along each eigen-direction from the dynamical matrix and determine whether the response of the system evolving at constant energy remains in the original eigenmode of the perturbation. For ?> ?c, a single contact breaks and fluctuations abruptly spread to all discrete harmonic modes. As ? increases further all harmonic modes disappear into a continuous frequency band. We find that ?c˜??/N, and thus jammed particulate systems are inherently nonharmonic with no linear vibrational response regime as N->? over the full range of ??, and as ??->0 at any N. This breakdown of harmonic behavior dramatically affects all aspects of system response including heat capacity, density of states, elastic moduli, and energy propagation.

Shattuck, Mark D.

2011-03-01

220

Rheological properties of asphalts with particulate additives  

SciTech Connect

The Superpave asphalt binder specifications are performance-based specifications for purchasing asphalt binders for the construction of roads. This means that the asphalt is characterized by fundamental material (rheological) properties that relate to the distress modes of the pavements. The distress modes addressed are primarily rutting, fatigue cracking and low temperature cracking. For example, G*/sin({delta}) is designed to predict the rutting potential of pavements, where G* is the magnitude of the complex shear modulus and 6 is the phase angle. The binder for a road that is situated in a certain climatic zone requires the binder to have a minimum G*/sin({delta}) of 2200 Pa at the highest consecutive 7-day average pavement temperature the road had experienced. Implicit in such a performance based specification is that the fundamental property, G*/sin({delta}), of the binder correlates with rutting potential of the pavement regardless of the nature of the binder. In other words, the specification is transparent to the fact that the binder can simply be an asphalt, or an asphalt modified by polymers, particulates and other materials that can form a two-phase mixture. This paper discusses the asphalt-particulate system.

Shashidhar, N. [EBA Engineering, Baltimore, MD (United States); Chollar, B.H. [Federal Highway Administration, McLean, VA (United States)

1996-12-31

221

PARTICULATE HOT GAS STREAM CLEANUP TECHNICAL ISSUES  

SciTech Connect

This quarterly report describes technical activities performed under Contract No. DE-AC21-94MC31160. The analyses of hot gas stream cleanup (HGCU) ashes and descriptions of filter performance studied under Task 1 of this contract are designed to address problems with filter operation that are apparently linked to characteristics of the collected ash. This report includes summaries of analyses performed on particulate samples from Sierra Pacific Power Company's Pinon Pine Power Project. This report also reviews the status of the HGCU data bank of ash and char characteristics, and plans for enhancing the data bank with interactive querying of measured particulate properties. Task 1 plans for the remainder of the project include completion and delivery of the HGCU data bank. Task 2 of this project concerns the testing and failure analyses of new and used filter elements and filter materials. Task 2 work during the past quarter included preliminary testing of two materials. One material tested was the soft candle filter manufactured by CGC and supplied by ABB. The other material was N610/mullite manufactured by Albany International (AIT).

NONE

1999-05-01

222

Analysis of particulates on tape lift samples  

NASA Astrophysics Data System (ADS)

Particle counts on tape lift samples taken from a hardware surface exceeded threshold requirements in six successive tests despite repeated cleaning of the surface. Subsequent analysis of the particle size distributions of the failed tests revealed that the handling and processing of the tape lift samples may have played a role in the test failures. In order to explore plausible causes for the observed size distribution anomalies, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were employed to perform chemical analysis on collected particulates. SEM/EDX identified Na and S containing particles on the hardware samples in a size range identified as being responsible for the test failures. ToF-SIMS was employed to further examine the Na and S containing particulates and identified the molecular signature of sodium alkylbenzene sulfonates, a common surfactant used in industrial detergent. The root cause investigation suggests that the tape lift test failures originated from detergent residue left behind on the glass slides used to mount and transport the tape following sampling and not from the hardware surface.

Moision, Robert M.; Chaney, John A.; Panetta, Chris J.; Liu, De-Ling

2014-09-01

223

40 CFR 63.1357 - Temporary, conditioned exemption from particulate matter and opacity standards.  

Code of Federal Regulations, 2012 CFR

...conditioned exemption from particulate matter and opacity standards. 63.1357 ...conditioned exemption from particulate matter and opacity standards. (a) Subject...exempt from: (1) Any particulate matter and opacity standards of part 60 or...

2012-07-01

224

40 CFR 49.126 - Rule for limiting fugitive particulate matter emissions.  

Code of Federal Regulations, 2013 CFR

...Rule for limiting fugitive particulate matter emissions. 49.126 Section 49...Rule for limiting fugitive particulate matter emissions. (a) What is the purpose...limits the amount of fugitive particulate matter that may be emitted from certain...

2013-07-01

225

30 CFR 57.5060 - Limit on exposure to diesel particulate matter.  

Code of Federal Regulations, 2013 CFR

...false Limit on exposure to diesel particulate matter. 57.5060 Section 57.5060 Mineral Resources...Radiation, Physical Agents, and Diesel Particulate Matter Diesel Particulate Matter-Underground Only § 57.5060 Limit on...

2013-07-01

226

40 CFR 49.128 - Rule for limiting particulate matter emissions from wood products industry sources.  

Code of Federal Regulations, 2013 CFR

... false Rule for limiting particulate matter emissions from wood products industry...128 Rule for limiting particulate matter emissions from wood products industry...section limits the amount of particulate matter that may be emitted from certain...

2013-07-01

227

30 CFR 57.5060 - Limit on exposure to diesel particulate matter.  

Code of Federal Regulations, 2012 CFR

...false Limit on exposure to diesel particulate matter. 57.5060 Section 57.5060 Mineral Resources...Radiation, Physical Agents, and Diesel Particulate Matter Diesel Particulate Matter-Underground Only § 57.5060 Limit on...

2012-07-01

228

40 CFR 52.126 - Control strategy and regulations: Particulate matter.  

Code of Federal Regulations, 2013 CFR

...strategy and regulations: Particulate matter. 52.126 Section 52.126 Protection...strategy and regulations: Particulate matter. (a) The requirements of subpart...the national standards for particulate matter in Gila, Maricopa, Pima,...

2013-07-01

229

40 CFR 52.126 - Control strategy and regulations: Particulate matter.  

Code of Federal Regulations, 2012 CFR

...strategy and regulations: Particulate matter. 52.126 Section 52.126 Protection...strategy and regulations: Particulate matter. (a) The requirements of subpart...the national standards for particulate matter in Gila, Maricopa, Pima,...

2012-07-01

230

40 CFR 49.126 - Rule for limiting fugitive particulate matter emissions.  

Code of Federal Regulations, 2012 CFR

...Rule for limiting fugitive particulate matter emissions. 49.126 Section 49...Rule for limiting fugitive particulate matter emissions. (a) What is the purpose...limits the amount of fugitive particulate matter that may be emitted from certain...

2012-07-01

231

40 CFR 63.1357 - Temporary, conditioned exemption from particulate matter and opacity standards.  

Code of Federal Regulations, 2013 CFR

...conditioned exemption from particulate matter and opacity standards. 63.1357 ...conditioned exemption from particulate matter and opacity standards. (a) Subject...condition; (2) The target particulate matter emission level for each test...

2013-07-01

232

40 CFR 49.128 - Rule for limiting particulate matter emissions from wood products industry sources.  

Code of Federal Regulations, 2012 CFR

... false Rule for limiting particulate matter emissions from wood products industry...128 Rule for limiting particulate matter emissions from wood products industry...section limits the amount of particulate matter that may be emitted from certain...

2012-07-01

233

Trace metal composition of suspended particulate matter in the water column of the Black Sea  

E-print Network

Trace metal composition of suspended particulate matter in the water column of the Black Sea Ouz Particulates Suspended particulate matter Biogenic matter Biogenic material Plankton Planktonic metal Terrestrial Water column Anoxic basin Sediment Brackish water Rivers Danube Turkish rivers Enrichments

Murray, James W.

234

Modeling and interpreting the observed effects of ash on diesel particulate filter performance and regeneration  

E-print Network

Diesel particulate filters (DPF) are devices that physically capture diesel particulates to prevent their release to the atmosphere. Diesel particulate filters have seen widespread use in on- and off-road applications as ...

Wang, Yujun, Ph. D. Massachusetts Institute of Technology

2014-01-01

235

75 FR 17894 - Approval and Promulgation of Air Quality Implementation Plans; Wisconsin; Particulate Matter...  

Federal Register 2010, 2011, 2012, 2013

...the 24-hour fine particulate standard and revoking...standard for course particulate. Wisconsin updated...Federal standards for particulate matter. DATES: Comments...Acting Chief, Criteria Pollutant Section, Air...

2010-04-08

236

40 CFR 49.128 - Rule for limiting particulate matter emissions from wood products industry sources.  

Code of Federal Regulations, 2010 CFR

... false Rule for limiting particulate matter emissions from wood products industry...128 Rule for limiting particulate matter emissions from wood products industry...section limits the amount of particulate matter that may be emitted from certain...

2010-07-01

237

40 CFR 49.128 - Rule for limiting particulate matter emissions from wood products industry sources.  

Code of Federal Regulations, 2011 CFR

... false Rule for limiting particulate matter emissions from wood products industry...128 Rule for limiting particulate matter emissions from wood products industry...section limits the amount of particulate matter that may be emitted from certain...

2011-07-01

238

40 CFR 52.126 - Control strategy and regulations: Particulate matter.  

Code of Federal Regulations, 2010 CFR

...strategy and regulations: Particulate matter. 52.126 Section 52.126 Protection...strategy and regulations: Particulate matter. (a) The requirements of subpart...the national standards for particulate matter in Gila, Maricopa, Pima,...

2010-07-01

239

40 CFR 52.126 - Control strategy and regulations: Particulate matter.  

Code of Federal Regulations, 2011 CFR

...strategy and regulations: Particulate matter. 52.126 Section 52.126 Protection...strategy and regulations: Particulate matter. (a) The requirements of subpart...the national standards for particulate matter in Gila, Maricopa, Pima,...

2011-07-01

240

40 CFR 49.126 - Rule for limiting fugitive particulate matter emissions.  

Code of Federal Regulations, 2010 CFR

...Rule for limiting fugitive particulate matter emissions. 49.126 Section 49...Rule for limiting fugitive particulate matter emissions. (a) What is the purpose...limits the amount of fugitive particulate matter that may be emitted from certain...

2010-07-01

241

40 CFR 63.1357 - Temporary, conditioned exemption from particulate matter and opacity standards.  

Code of Federal Regulations, 2010 CFR

...conditioned exemption from particulate matter and opacity standards. 63.1357 ...conditioned exemption from particulate matter and opacity standards. (a) Subject...exempt from: (1) Any particulate matter and opacity standards of part 60 or...

2010-07-01

242

75 FR 65567 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Particulate Matter Standards  

Federal Register 2010, 2011, 2012, 2013

...Implementation Plans; Ohio; Particulate Matter Standards AGENCY: Environmental Protection...Chapter 3745-17, ``Particulate Matter Standards.'' The revisions were submitted...review requirements. The particulate matter (PM) standards contain the...

2010-10-26

243

40 CFR 63.1357 - Temporary, conditioned exemption from particulate matter and opacity standards.  

Code of Federal Regulations, 2011 CFR

...conditioned exemption from particulate matter and opacity standards. 63.1357 ...conditioned exemption from particulate matter and opacity standards. (a) Subject...exempt from: (1) Any particulate matter and opacity standards of part 60 or...

2011-07-01

244

30 CFR 57.5060 - Limit on exposure to diesel particulate matter.  

Code of Federal Regulations, 2010 CFR

...false Limit on exposure to diesel particulate matter. 57.5060 Section 57.5060 Mineral Resources...Radiation, Physical Agents, and Diesel Particulate Matter Diesel Particulate Matter-Underground Only § 57.5060 Limit on...

2010-07-01

245

40 CFR 49.126 - Rule for limiting fugitive particulate matter emissions.  

Code of Federal Regulations, 2011 CFR

...Rule for limiting fugitive particulate matter emissions. 49.126 Section 49...Rule for limiting fugitive particulate matter emissions. (a) What is the purpose...limits the amount of fugitive particulate matter that may be emitted from certain...

2011-07-01

246

40 CFR 52.1781 - Control strategy: Sulfur oxides and particulate matter.  

Code of Federal Regulations, 2010 CFR

...strategy: Sulfur oxides and particulate matter. 52.1781 Section 52.1781 Protection...strategy: Sulfur oxides and particulate matter. (a) The plan's control strategy for particulate matter as outlined in the...

2010-07-01

247

40 CFR 52.1781 - Control strategy: Sulfur oxides and particulate matter.  

Code of Federal Regulations, 2011 CFR

...strategy: Sulfur oxides and particulate matter. 52.1781 Section 52.1781 Protection...strategy: Sulfur oxides and particulate matter. (a) The plan's control strategy for particulate matter as outlined in the...

2011-07-01

248

30 CFR 57.5060 - Limit on exposure to diesel particulate matter.  

Code of Federal Regulations, 2011 CFR

...false Limit on exposure to diesel particulate matter. 57.5060 Section 57.5060 Mineral Resources...Radiation, Physical Agents, and Diesel Particulate Matter Diesel Particulate Matter-Underground Only § 57.5060 Limit on...

2011-07-01

249

40 CFR 52.578 - Control Strategy: Sulfur oxides and particulate matter.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Control Strategy: Sulfur oxides and particulate matter. 52...Georgia> § 52.578 Control Strategy: Sulfur oxides and particulate matter. Link...follows: § 52.578 Control Strategy: Sulfur oxides and particulate matter....

2011-07-01

250

40 CFR 63.1357 - Temporary, conditioned exemption from particulate matter and opacity standards.  

...conditioned exemption from particulate matter and opacity standards. 63.1357 ...conditioned exemption from particulate matter and opacity standards. (a) Subject...condition; (2) The target particulate matter emission level for each test...

2014-07-01

251

30 CFR 57.5060 - Limit on exposure to diesel particulate matter.  

...false Limit on exposure to diesel particulate matter. 57.5060 Section 57.5060 Mineral Resources...Radiation, Physical Agents, and Diesel Particulate Matter Diesel Particulate Matter-Underground Only § 57.5060 Limit on...

2014-07-01

252

40 CFR 52.2276 - Control strategy and regulations: Particulate matter.  

...strategy and regulations: Particulate matter. 52.2276 Section 52.2276 Protection...strategy and regulations: Particulate matter. (a) Part D conditional approval...Inc., shall not emit particulate matter in excess of 0.03 grains per...

2014-07-01

253

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...

254

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...

255

Method for removing particulate matter from a gas stream  

DOEpatents

Particulate matter is removed from a stream of pressurized gas by directing the stream of gas upwardly through a bed of porous material, the porous bed being held in an open ended container and at least partially submerged in liquid. The passage of the gas through the porous bed sets up a circulation in the liquid which cleans the particulate matter from the bed.

Postma, Arlin K. (Benton City, WA)

1984-01-01

256

Particulate Air Pollution and Mortality: The Particle Epidemiology Evaluation Project  

Microsoft Academic Search

The second colloquium on particulate air pollution marks the reemergence of air pollution, generated by combustion sources, as a serious public health concern throughout the developed world. This article provides a perspective on the epidemiologic evidence on particulate air pollution and health. It addresses the evolution of methods for investigating air pollution and mortality and morbidity and the inter-pretational framework

Jonathan M. Samet; Scott L. Zeger; Julia E. Kelsall; Jing Xu

1998-01-01

257

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...

258

TITLE: PARTICULATE SIZE DISTRIBUTIONS AND SEQUENTIAL FRAGMENTATION\\/TRANSPORT THEORY  

Microsoft Academic Search

Particulate size distributions offer the scientist impor- tant clues about the mechanism(s) responsible for their formation. These distributions are complex, often being the combination of several subpopulations that bear the signa- ture of specific fragmentation and particulate transport processes. Historically, such distributions have been char- acterized by some empirical distribution law such as the lognormal or Weibull distributions, but such

Wilbur Brown

259

Introduction Analysis of elemental concentrations in aquatic particulate  

E-print Network

96 Introduction Analysis of elemental concentrations in aquatic particulate matter (seston) has followed by GC/thermal conductivity detection of CO2 and N2 . For particulate phospho- rus, persulfate is nondestructive to sam- ples; it is also fast and requires no consumables. The theory and application of NIRS were

Sterner, Robert W.

260

Theory of Antigen-Antibody Induced Particulate Aggregation  

Microsoft Academic Search

Theoretical approaches on particulate aggregation phenomena are reviewed. The validity and incompleteness of these existing theories when applied to antigen-antibody agglutinating systems are studied. A theory of antigen-antibody induced particulate aggregation is developed by investigating the stability of model systems of particles. Conditions for the formation of large aggregates are derived by imposing the requirement that at equilibrium a statistically

Ki-Chuen Chak

1980-01-01

261

Magnetocentrifugal separation of particulates: Theory and principles of operation  

Microsoft Academic Search

The theory and principles of operation of the new magnetocentrifugal separation are formulated. Magnetic and centrifugal g numbers for monodisperse and polydisperse particulates are defined. It is shown that the magnitude of electromagnetic and centrifugal forces can be matched in the full scale of centrifugal fields available to date. Magnetocentrifugal separation can be applied to separation of particulates down to

Yoram Zimmels

1986-01-01

262

A review of particulate reinforcement theories for polymer composites  

Microsoft Academic Search

A concerted survey is presented of the existing theories for predicting the strength and modulus of particulate-filled polymeric composites. The macroscopic behaviour of particulate composites is affected by the size, shape, and the distribution of the inclusions. The interfacial adhesion between the matrix and inclusion is also important. The limitation of theoretical models in describing these parameters and expressing the

S. Ahmed; F. R. Jones

1990-01-01

263

IMPACT OF SUSPENDED PARTICULATES ON PCB VOLATILIZATION FROM SEDIMENTS  

EPA Science Inventory

The objective of this research was to experimentally quantify the mass of PCBs that can be transported from PCB-contaminated suspended particulate to the air phase under various conditions as a means of evaluating the mechanism and importance of suspended particulates in volatili...

264

40 CFR 86.1343-88 - Calculations; particulate exhaust emissions.  

Code of Federal Regulations, 2011 CFR

...mass particulate, grams per brake horsepower-hour. (2) PC = Mass particulate measured during the cold-start test, grams...per test phase. (PH = Pmass for the hot-start test and PC = Pmass for the cold-start test. (2) Vmix =...

2011-07-01

265

40 CFR 52.1230 - Control strategy and rules: Particulates.  

Code of Federal Regulations, 2011 CFR

...Minnesota submitted a committal SIP for particulate matter with an aerodynamic diameter equal to or less than 10 micrometers (PM10...to attainment of the NAAQS for particulate matter with an aerodynamic diameter less than or equal to a nominal 10...

2011-07-01

266

40 CFR 52.1230 - Control strategy and rules: Particulates.  

Code of Federal Regulations, 2013 CFR

...Minnesota submitted a committal SIP for particulate matter with an aerodynamic diameter equal to or less than 10 micrometers (PM10...to attainment of the NAAQS for particulate matter with an aerodynamic diameter less than or equal to a nominal 10...

2013-07-01

267

40 CFR 52.1230 - Control strategy and rules: Particulates.  

Code of Federal Regulations, 2012 CFR

...Minnesota submitted a committal SIP for particulate matter with an aerodynamic diameter equal to or less than 10 micrometers (PM10...to attainment of the NAAQS for particulate matter with an aerodynamic diameter less than or equal to a nominal 10...

2012-07-01

268

40 CFR 52.1230 - Control strategy and rules: Particulates.  

Code of Federal Regulations, 2010 CFR

...Minnesota submitted a committal SIP for particulate matter with an aerodynamic diameter equal to or less than 10 micrometers (PM10...to attainment of the NAAQS for particulate matter with an aerodynamic diameter less than or equal to a nominal 10...

2010-07-01

269

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...

270

40 CFR 52.332 - Control strategy: Particulate matter.  

Code of Federal Regulations, 2011 CFR

...Environment 3 2011-07-01 2011-07-01 false Control strategy: Particulate matter. 52.332 Section 52.332 Protection...PROMULGATION OF IMPLEMENTATION PLANS Colorado § 52.332 Control strategy: Particulate matter. (a) On April 9, 1992,...

2011-07-01

271

The Relocation of Particulate Contamination During Space Flight  

NASA Technical Reports Server (NTRS)

A computer simulation program to model the redistribution of particulate contaminants on a spacecraft after launch is developed. The component models for particulate adhesion, meteoroid impact, and electrostatic forces are described and intermediate results are presented. The results of a sample calculation show that the recontamination process is important.

Barengoltz, J.; Edgars, D.

1975-01-01

272

Method for immobilizing particulate materials in a packed bed  

DOEpatents

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.

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

273

Method for immobilizing particulate materials in a packed bed  

DOEpatents

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.

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

1999-02-02

274

Process for off-gas particulate removal and apparatus therefor  

DOEpatents

In the event of a breach in the off-gas line of a melter operation requiring closure of the line, a secondary vessel vent line is provided with a particulate collector utilizing atomization for removal of large particulates from the off-gas. The collector receives the gas containing particulates and directs a portion of the gas through outer and inner annular channels. The collector further receives a fluid, such as water, which is directed through the outer channel together with a second portion of the particulate-laden gas. The outer and inner channels have respective ring-like termination apertures concentrically disposed adjacent one another on the outer edge of the downstream side of the particulate collector. Each of the outer and inner channels curves outwardly away from the collector`s centerline in proceeding toward the downstream side of the collector. Gas flow in the outer channel maintains the fluid on the channel`s wall in the form of a ``wavy film,`` while the gas stream from the inner channel shears the fluid film as it exits the outer channel in reducing the fluid to small droplets. Droplets formed by the collector capture particulates in the gas stream by one of three mechanisms: impaction, interception or Brownian diffusion in removing the particulates. The particulate-laden droplets are removed from the fluid stream by a vessel vent condenser or mist eliminator. 4 figs.

Carl, D.E.

1997-10-21

275

Process for off-gas particulate removal and apparatus therefor  

DOEpatents

In the event of a breach in the off-gas line of a melter operation requiring closure of the line, a secondary vessel vent line is provided with a particulate collector utilizing atomization for removal of large particulates from the off-gas. The collector receives the gas containing particulates and directs a portion of the gas through outer and inner annular channels. The collector further receives a fluid, such as water, which is directed through the outer channel together with a second portion of the particulate-laden gas. The outer and inner channels have respective ring-like termination apertures concentrically disposed adjacent one another on the outer edge of the downstream side of the particulate collector. Each of the outer and inner channels curves outwardly away from the collector's centerline in proceeding toward the downstream side of the collector. Gasflow in the outer channel maintains the fluid on the channel's wall in the form of a "wavy film," while the gas stream from the inner channel shears the fluid film as it exits the outer channel in reducing the fluid to small droplets. Droplets formed by the collector capture particulates in the gas stream by one of three mechanisms: impaction, interception or Brownian diffusion in removing the particulates. The particulate-laden droplets are removed from the fluid stream by a vessel vent condenser or mist eliminator.

Carl, Daniel E. (Orchard Park, NY)

1997-01-01

276

Heart rate variability associated with particulate air pollution  

Microsoft Academic Search

Background: Epidemiologic studies have linked fine particulate air pollution with cardiopulmonary mortality, yet underlying biologic mechanisms remain unknown. Changes in heart rate variability (HRV) may reflect changes in cardiac autonomic function and risk of sudden cardiac death. This study evaluated changes in mean heart rate and HRV in human beings associated with changes in exposure to particulate air pollution. Methods:

C. Arden Pope; Richard L. Verrier; Eric G. Lovett; Andrew C. Larson; Mark E. Raizenne; Richard E. Kanner; Joel Schwartz; G. Martin Villegas; Diane R. Gold; Douglas W. Dockery

1999-01-01

277

Turbulent particulate transportation during electrostatic precipitation  

NASA Astrophysics Data System (ADS)

The generation of secondary flows and turbulence by a corona discharge influences particle transport in an electrostatic precipitator (ESP), and is known to play an important role in the particle collection process. However, it is difficult to characterise theoretically and experimentally the ``turbulent'' fluctuations of the gas flow produced by negative tuft corona. Because of this difficulty, only limited studies have been undertaken previously to understand the structure of corona-induced turbulence and its influence on particle transport in ESPs. The present study is aimed at modelling electrohydrodynamic turbulent flows and particle transport, and at establishing an unproved understanding of them. For a multiply interactive coupling of electrostatics, fluid dynamics and particle dynamics, a strongly coupled system of the governing equations has been solved. The present computer model has considered the most important interaction mechanisms including an ionic wind, corona- induced turbulence and the particle space charge effect. Numerical simulations have been performed for the extensive validation of the numerical and physical models. To account for electrically excited turbulence associated with the inhomogeneous and unsteady characteristics of negative corona discharges, a new turbulence model (called the electrostatic turbulence model) has been developed. In this, an additional production or destruction term is included into the turbulent kinetic energy and dissipation rate equations. It employs a gradient type model of the current density and an electrostatic diffusivity concept. The results of the computation show that the electrostatic turbulence model gives much better agreement with the experimental data than the conventional RNG k-? turbulence model when predicting turbulent gas flows and particle distributions in an ESP. Computations of turbulent particulate two-phase flows for both mono-dispersed and poly-dispersed particles have been performed. The effects of coriona-induced turbulence and the particle space charge on particle transport and the collection process have been investigated. The calculated results for the poly-dispersed particulate flow were compared with those of the mono-dispersed particulate flow, and significant differences were demonstrated. It is established that effective particle- particle interaction occurs, due to the influence of the particle space charge, even for dilute gas-particle flows that occur in ESPs.

Choi, Bum Seog

278

Particulate hot gas stream cleanup technical issues  

SciTech Connect

This is the tenth in a series of quarterly reports describing the activities performed under Contract No. DE-AC21-94MC31160. Analyses of Hot Gas Stream Cleanup (HGCU) ashes and descriptions of filter performance address aspects of filter operation that are apparently linked to the characteristics of the collected ash or the performance of the ceramic bed filter elements. Task I is designed to generate a data base of the key characteristics of ashes collected from operating advanced particle filters (APFS) and to relate these ash properties to the operation and performance of these filters. Task 2 concerns testing and failure analysis of ceramic filter elements. Under Task I during the past quarter, analyses were performed on a particulate sample from the Transport Reactor Demonstration Unit (TRDU) located at the University of North Dakota Energy and Environmental Research Center. Analyses are in progress on ash samples from the Advanced Particulate Filter (APF) at the Pressurized Fluidized-Bed Combustor (PFBC) that was in operation at Tidd and ash samples from the Pressurized Circulating Fluid Bed (PCFB) system located at Karhula, Finland. A site visit was made to the Power Systems Development Facility (PSDF) to collect ash samples from the filter vessel and to document the condition of the filter vessel with still photographs and videotape. Particulate samples obtained during this visit are currently being analyzed for entry into the Hot Gas Cleanup (HGCU) data base. Preparations are being made for a review meeting on ash bridging to be held at Department of Energy Federal Energy Technology Center - Morgantown (DOE/FETC-MGN) in the near future. Most work on Task 2 was on hold pending receipt of additional funds; however, creep testing of Schumacher FT20 continued. The creep tests on Schumacher FT20 specimens just recently ended and data analysis and comparisons to other data are ongoing. A summary and analysis of these creep results will be sent out shortly. Creep testing of two Refractron 326 specimens is now in progress. Among the tasks expected to be completed this quarter are analysis of the creep data obtained thus far, microstructural analysis of Refractron 326 and Schumacher FT20, definition of bending loads on candle filters, and characterization of additional candle filters from Karhula.

NONE

1998-09-01

279

[Distribution characteristics of particulate mercury in aerosol in coastal city].  

PubMed

Particulate mercury, which is bound with aerosol in atmosphere, has a negative impact on human health and the environment, also plays an important role in the biogeochemical process of mercury. In this paper, taking southeast coastal city of Xiamen as research object, the PM2.5, PM10 and TSP were collected in residential, tourism, industrial area and background, respectively, during four seasons (October 2008-September 2009). RA-915 + mercury analyzer was employed to determinate mercury concentration in different size particle matters based on zeeman atomic absorption spectrometry. The results showed that the contents of particulate mercury in different size of aerosol during Winter, Spring were obviously higher than that of Summer, Autumn; the concentrations of particulate mercury in fine particle during Spring, Summer, Autumn and Winter were (51.46 +/- 19.28), (42.41 +/- 12.74), (38.38 +/- 6.08) and (127.23 +/- 33.70) pg/m3, respectively. The experimental data showed that the particulate mercury were mainly distributed in fine particles (PM2.5), which covered 42.48%-67.87%, and it can be concluded that the rate of particulate mercury enrichment in coarse particle was much lower than that of fine particle. The sequence of atmospheric particulate mercury concentration in different functional areas was: background < resident < tourism < industrial area < suburban; which showed characteristics of spatial distribution of particulate mercury was affected by the sampling location. On the whole, Xiamen had a low level of atmospheric particulate mercury; the enrichment of PM2.5 to particulate mercury was significantly higher than that of PM10 and TSP, and showed that fine particle pollution should be tightly controlled to reduce particulate mercury. PMID:21229731

Zhang, Fu-Wang; Zhao, Jin-Ping; Chen, Jin-Sheng; Xu, Ya

2010-10-01

280

Exposure to particulate hexavalent chromium exacerbates allergic asthma pathology  

SciTech Connect

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.

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

281

Overlap zoned electrically heated particulate filter  

DOEpatents

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

Gonze, Eugene V [Pinckney, MI; Chapman, Mark R [Brighton, MI

2011-07-19

282

The vega particulate shell: comets or asteroids?  

PubMed

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

Weissman, P R

1984-06-01

283

Assessment of Internal Fabric of Particulate Materials  

NASA Technical Reports Server (NTRS)

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.

Alshibi, Khalid A.

2000-01-01

284

Leishmania infantum Ecto-Nucleoside Triphosphate Diphosphohydrolase-2 is an Apyrase Involved in Macrophage Infection and Expressed in Infected Dogs  

PubMed Central

Background Visceral leishmaniasis is an important tropical disease, and Leishmania infantum chagasi (synonym of Leishmania infantum) is the main pathogenic agent of visceral leishmaniasis in the New World. Recently, ecto-nucleoside triphosphate diphosphohydrolases (E-NTPDases) were identified as enablers of infection and virulence factors in many pathogens. Two putative E-NTPDases (?70 kDa and ?45 kDa) have been found in the L. infantum genome. Here, we studied the ?45 kDa E-NTPDase from L. infantum chagasi to describe its natural occurrence, biochemical characteristics and influence on macrophage infection. Methodology/Principal Findings We used live L. infantum chagasi to demonstrate its natural ecto-nucleotidase activity. We then isolated, cloned and expressed recombinant rLicNTPDase-2 in bacterial system. The recombinant rLicNTPDase-2 hydrolyzed a wide variety of triphosphate and diphosphate nucleotides (GTP> GDP ?=? UDP> ADP> UTP ?=? ATP) in the presence of calcium or magnesium. In addition, rLicNTPDase-2 showed stable activity over a pH range of 6.0 to 9.0 and was partially inhibited by ARL67156 and suramin. Microscopic analyses revealed the presence of this protein on cell surfaces, vesicles, flagellae, flagellar pockets, kinetoplasts, mitochondria and nuclei. The blockade of E-NTPDases using antibodies and competition led to lower levels of parasite adhesion and infection of macrophages. Furthermore, immunohistochemistry showed the expression of E-NTPDases in amastigotes in the lymph nodes of naturally infected dogs from an area of endemic visceral leishmaniasis. Conclusions/Significance In this work, we cloned, expressed and characterized the NTPDase-2 from L. infantum chagasi and demonstrated that it functions as a genuine enzyme from the E-NTPDase/CD39 family. We showed that E-NTPDases are present on the surface of promastigotes and in other intracellular locations. We showed, for the first time, the broad expression of LicNTPDases in naturally infected dogs. Additionally, the blockade of NTPDases led to lower levels of in vitro adhesion and infection, suggesting that these proteins are possible targets for rational drug design. PMID:25393008

Vasconcellos, Raphael De Souza; Mariotini-Moura, Christiane; Gomes, Rodrigo Saar; Serafim, Tiago Donatelli; Firmino, Rafaela de Cássia; Silva e Bastos, Matheus; de Castro, Felipe Freitas; de Oliveira, Claudia Miranda; Borges-Pereira, Lucas; de Souza, Anna Cláudia Alves; de Souza, Ronny Francisco; Gómez, Gabriel Andres Tafur; Pinheiro, Aimara da Costa; Maciel, Talles Eduardo Ferreira; Silva-Júnior, Abelardo; Bressan, Gustavo Costa; Almeida, Márcia Rogéria; Baqui, Munira Muhammad Abdel; Afonso, Luís Carlos Crocco; Fietto, Juliana Lopes Rangel

2014-01-01

285

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

SciTech Connect

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.

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

286

Particulate contamination removal from wafers using plasmas and mechanical agitation  

DOEpatents

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.

Selwyn, Gary S. (Los Alamos, NM)

1998-01-01

287

Structural evolution of self-expanding arrays of charged particulates.  

PubMed

Self-expansion patterns of unconstrained assemblies of charged particulates are simulated by solution of their individual trajectories. The general behaviour of these systems is considered regarding their expansion shape and structure. As the particulates cannot be described, in general, in terms of massless charged entities, the complete equation of motion, inclusive of the inertial and other size effects, must be applied to each and every member of the assembly. It is shown that irrespective of the initial position of the particulates and the time dependent shape of the assembly, when expanding in free space or else the particulates are identical in size, shape and mass, they self-expand asymptotically into a circular or spherical shape with an inner structure that tends to uniformity. This behaviour persists irrespective of the size and charge level of the particulates, or whether they form a single or multiple separate groups in one, two and three dimensions. In this context, ionic gaseous assemblies that fit into the realm of continua, are included. Two- and three-dimensional examples of simulation outputs for different particulate assemblies, illustrate typical self-expansion patterns. Internal structures that evolve in two-dimensional self-expanding arrays are shown to be different compared to those obtained in three dimensions. These simulations show that models of particle capture by random self-expanding arrays of charged particulates, may lack physical grounds, as they contradict the asymptotic mode of uniform and ordered self-expansion that is expected from the array. PMID:16266716

Zimmels, Y; Kojevnikova, S; Agnon, Y

2006-04-15

288

A laser particulate spectrometer for a space simulation facility  

NASA Technical Reports Server (NTRS)

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.

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

1975-01-01

289

Propellant inefficiency due to particulates in a Pulsed Plasma Thruster  

SciTech Connect

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.

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

290

Characterization of functional groups of airborne particulate matter  

NASA Astrophysics Data System (ADS)

Particulate matter of organic combustibles burning consists of various hydrocarbons and radicals, which may cause harmful impact to human health. In this study solid particulate matter were collected on the filters from burning of various combustibles in a burning chamber and from atmosphere of city of Riga by dichotomous impactor. FTIR spectra were obtained before and after samples' treatment. Absorptions associated with aliphatic and aromatic hydrocarbons and alcohol functional groups were observed in the FTIR spectra. Free radicals of particulate matter were detected by electron paramagnetic resonance (EPR).

Baitimirova, M.; Katkevics, J.; Baumane, L.; Bakis, E.; Viksna, A.

2013-12-01

291

Particulate oxidative burden associated with firework activity.  

PubMed

Firework events are capable of inducing particulate matter (PM) episodes that lead to exceedances of regulatory limit values. As short-term peaks in ambient PM concentration have been associated with negative impacts on respiratory and cardiovascular health, we performed a detailed study of the consequences of firework events in London on ambient air quality and PM composition. These changes were further related to the oxidative activity of daily PM samples by assessing their capacity to drive the oxidation of physiologically important lung antioxidants including ascorbate, glutathione and urate (oxidative potential, OP). Twenty-four hour ambient PM samples were collected at the Marylebone Road sampling site in Central London over a three week period, including two major festivals celebrated with pyrotechnic events: Guy Fawkes Night and Diwali. Pyrotechnic combustion events were characterized by increased gas phase pollutants levels (NO(x) and SO(2)), elevated PM mass concentrations, and trace metal concentrations (specifically Sr, Mg, K, Ba, and Pb). Relationships between NO(x), benzene, and PM(10) were used to apportion firework and traffic source fractions. A positive significant relationship was found between PM oxidative burden and individual trace metals associated with each of these apportioned source fractions. The level of exposure to each source fraction was significantly associated with the total OP. The firework contribution to PM total OP, on a unit mass basis, was greater than that associated with traffic sources: a 1 ?g elevation in firework and traffic PM fraction concentration was associated with a 6.5 ± 1.5 OP(T) ?g(-1) and 5.2 ± 1.4 OP(T) ?g(-1) increase, respectively. In the case of glutathione depletion, firework particulate OP (3.5 ± 0.8 OP(GSH) ?g(-1)) considerably exceeded that due to traffic particles (2.2 ± 0.8 OP(GSH) ?g(-1)). Therefore, in light of the elevated PM concentrations caused by firework activity and the increased oxidative activity of this PM source, there is value in examining if firework derived PM is related to acute respiratory outcomes. PMID:20886897

Godri, Krystal J; Green, David C; Fuller, Gary W; Dall'Osto, Manuel; Beddows, David C; Kelly, Frank J; Harrison, Roy M; Mudway, Ian S

2010-11-01

292

Origin and biochemical cycling of particulate nitrogen in the Mandovi estuary  

Microsoft Academic Search

Mandovi estuary is a tropical estuary strongly influenced by the southwest monsoon. In order to understand, sources and fate of particulate organic nitrogen, suspended particulate matter (SPM) collected from various locations, was analyzed for particulate organic carbon (POC) and particulate organic nitrogen (PON), ?13CPOC, total hydrolysable amino acid enantiomers (l- and d- amino acids) concentration and composition. ?13CPOC values were

Loreta Fernandes

2011-01-01

293

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

Microsoft Academic Search

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

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

294

Enrichment and Exposure of Particulate Lead in a Traffic Environment in India  

Microsoft Academic Search

Enrichment of lead in respirable suspended particulate matter (RSPM) and exposure of human blood to particulate lead in traffic environment were investigated. Samples of RSPM, non-respirable suspended particulate matter (NRSPM) and total suspended particulate matter (TSPM) were collected in 10 sampling sites located on National Highway No. 6, Durg–Bhilai section of Chhattisgarh State of India. Forty blood samples, out of

Rajnikant Sharma; Shamsh Pervez

2003-01-01

295

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

E-print Network

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

California at Los Angeles, University of

296

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...

297

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...

298

SAMPLING AND ANALYTICAL METHODOLOGY FOR ATMOSPHERIC PARTICULATE NITRATES  

EPA Science Inventory

Environmental conditions that affect atmospheric particulate nitrate sampling were identified, and improved sampling and analytical procedures were developed. Evaluation of potential sources of error in high volume nitrate sampling showed that artifact nitrate formation on common...

299

Mechanical Properties of Particulate Reinforced Aluminium Alloy Matrix Composite  

NASA Astrophysics Data System (ADS)

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.

Sayuti, M.; Sulaiman, S.; Baharudin, B. T. H. T.; Arifin, M. K. A.; Suraya, S.; Vijayaram, T. R.

2011-01-01

300

New Approach to Monitor Transboundary Particulate Pollution over Northeast Asia.  

National Technical Information Service (NTIS)

A new approach to more accurately monitor and evaluate transboundary particulate matter (PM) pollution is introduced based on aerosol optical products from Korea's Geostationary Ocean Color Imager (GOCI). The area studied is Northeast Asia (including east...

B. N. Holben, C. H. Song, C. K. Song, G. R. Carmichael, J. Kim, J. Lee, J. H. Woo, M. E. Park, R. S. Park, S. Lee, S. S. Lee, T. F. Eck, Y. D. Hong

2014-01-01

301

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...

302

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 ...

303

Mechanical Properties of Particulate Reinforced Aluminium Alloy Matrix Composite  

SciTech Connect

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.

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

304

40 CFR 60.132 - Standard for particulate matter.  

Code of Federal Regulations, 2013 CFR

... AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Secondary Brass and Bronze Production Plants § 60.132 Standard for particulate matter. (a) On and after the date on which...

2013-07-01

305

40 CFR 60.132 - Standard for particulate matter.  

Code of Federal Regulations, 2012 CFR

... AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Secondary Brass and Bronze Production Plants § 60.132 Standard for particulate matter. (a) On and after the date on which...

2012-07-01

306

40 CFR 60.132 - Standard for particulate matter.  

Code of Federal Regulations, 2011 CFR

... AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Secondary Brass and Bronze Production Plants § 60.132 Standard for particulate matter. (a) On and after the date on which...

2011-07-01

307

40 CFR 60.132 - Standard for particulate matter.  

Code of Federal Regulations, 2010 CFR

... AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Secondary Brass and Bronze Production Plants § 60.132 Standard for particulate matter. (a) On and after the date on which...

2010-07-01

308

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...

309

40 CFR 60.182 - Standard for particulate matter.  

Code of Federal Regulations, 2012 CFR

...operator subject to the provisions of this subpart shall cause to be discharged into the atmosphere from any blast furnace, dross reverberatory furnace, or sintering machine discharge end any gases which contain particulate matter in excess of 50...

2012-07-01

310

40 CFR 60.122 - Standard for particulate matter.  

Code of Federal Regulations, 2013 CFR

...cause the discharge into the atmosphere from a blast (cupola) or reverberatory furnace any gases which: (1) Contain particulate...the discharge into the atmosphere from any pot furnace any gases which exhibit 10 percent opacity...

2013-07-01

311

40 CFR 60.122 - Standard for particulate matter.  

Code of Federal Regulations, 2012 CFR

...cause the discharge into the atmosphere from a blast (cupola) or reverberatory furnace any gases which: (1) Contain particulate...the discharge into the atmosphere from any pot furnace any gases which exhibit 10 percent opacity...

2012-07-01

312

40 CFR 60.182 - Standard for particulate matter.  

Code of Federal Regulations, 2010 CFR

...operator subject to the provisions of this subpart shall cause to be discharged into the atmosphere from any blast furnace, dross reverberatory furnace, or sintering machine discharge end any gases which contain particulate matter in excess of 50...

2010-07-01

313

40 CFR 60.182 - Standard for particulate matter.  

Code of Federal Regulations, 2011 CFR

...operator subject to the provisions of this subpart shall cause to be discharged into the atmosphere from any blast furnace, dross reverberatory furnace, or sintering machine discharge end any gases which contain particulate matter in excess of 50...

2011-07-01

314

40 CFR 60.182 - Standard for particulate matter.  

Code of Federal Regulations, 2013 CFR

...operator subject to the provisions of this subpart shall cause to be discharged into the atmosphere from any blast furnace, dross reverberatory furnace, or sintering machine discharge end any gases which contain particulate matter in excess of 50...

2013-07-01

315

40 CFR 60.122 - Standard for particulate matter.  

Code of Federal Regulations, 2011 CFR

...cause the discharge into the atmosphere from a blast (cupola) or reverberatory furnace any gases which: (1) Contain particulate...the discharge into the atmosphere from any pot furnace any gases which exhibit 10 percent opacity...

2011-07-01

316

40 CFR 60.122 - Standard for particulate matter.  

Code of Federal Regulations, 2010 CFR

...cause the discharge into the atmosphere from a blast (cupola) or reverberatory furnace any gases which: (1) Contain particulate...the discharge into the atmosphere from any pot furnace any gases which exhibit 10 percent opacity...

2010-07-01

317

AIRWAY EPITHELIAL EFFECTS OF PARTICULATE POLLUTANTS: ROLE OF METAL INTERACTIONS  

EPA Science Inventory

Numerous epidemiologic studies have demonstrated positive associations with particulate matter (PM) air pollution and daily respiratory morbidity - including exacerbations of asthma. Data are needed to elucidate which PM subcomponents may be mediating disease exacerbation in ind...

318

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...

319

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...

320

EFFECTS OF PARTICULATE MATTER (PM) ON CARDIAC CELLS  

EPA Science Inventory

Although epidemiology studies, clinical studies, and animal studies indicate that particulate matter (PM) can affect cardiac function, there is no real understanding of the underlying cellular, biochemical, and molecular processes response for PM-induced cardiac dysfunction. It i...

321

The LEO Particulate Environment as Determined by LDEF  

NASA Technical Reports Server (NTRS)

The Meteoroid & Debris Special Investigation Group has been studying the low-Earth orbit particulate environment by examining and documenting impact craters that occurred on the Long Duration Exposure Facility (LDEF) during its 5.7 year stay in orbit.

See, Thomas H.; Zolensky, Michael E.; Hoerz, Friedrick; Bernhard, P.; Leago, Kimberly S.; Warren, Jack L.; Sapp, Clyde A.; Foster, Tammy R.; Kinard, William H.

1993-01-01

322

REVIEW OF DIESEL PARTICULATE MATTER SAMPLING METHODS Supplemental Report # 2  

E-print Network

REVIEW OF DIESEL PARTICULATE MATTER SAMPLING METHODS Supplemental Report # 2 AEROSOL DYMAMICS Arnold University of Minnesota Department of Mechanical Engineering Center for Diesel Research................................................................................................. 3 Diesel aerosol composition and structure................................................... 3

Minnesota, University of

323

Automated particulate sampler field test model operations guide  

SciTech Connect

The Automated Particulate Sampler Field Test Model Operations Guide is a collection of documents which provides a complete picture of the Automated Particulate Sampler (APS) and the Field Test in which it was evaluated. The Pacific Northwest National Laboratory (PNNL) Automated Particulate Sampler was developed for the purpose of radionuclide particulate monitoring for use under the Comprehensive Test Ban Treaty (CTBT). Its design was directed by anticipated requirements of small size, low power consumption, low noise level, fully automatic operation, and most predominantly the sensitivity requirements of the Conference on Disarmament Working Paper 224 (CDWP224). This guide is intended to serve as both a reference document for the APS and to provide detailed instructions on how to operate the sampler. This document provides a complete description of the APS Field Test Model and all the activity related to its evaluation and progression.

Bowyer, S.M.; Miley, H.S.

1996-10-01

324

PARTICULATE SAMPLING AND SUPPORT: FINAL REPORT. EXECUTIVE SUMMARY  

EPA Science Inventory

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

325

Ultrasonic wave propagation in random and periodic particulate composites  

E-print Network

Current theoretical models are insufficient to predict the dynamic behavior of particulate composites under ultrasonic loading. To facilitate the creation of more accurate models, ultrasonic tests have been performed to expand the database...

Henderson, Benjamin Kyle

2012-06-07

326

40 CFR 60.682 - Standard for particulate matter.  

Code of Federal Regulations, 2010 CFR

...PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standard of Performance for Wool Fiberglass Insulation Manufacturing Plants § 60.682 Standard for particulate matter. On and after the date on which the...

2010-07-01

327

40 CFR 60.682 - Standard for particulate matter.  

Code of Federal Regulations, 2012 CFR

...PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standard of Performance for Wool Fiberglass Insulation Manufacturing Plants § 60.682 Standard for particulate matter. On and after the date on which the...

2012-07-01

328

Modeling of Particulate Matter Emissions from Agricultural Operations  

E-print Network

State Air Pollution Regulation Agencies (SAPRAs) issue and enforce permits that limit particulate matter emissions from all sources including layer and broiler facilities, cattle feedyards, dairies, cotton gins, and grain elevators...

Bairy, Jnana 1988-

2013-01-02

329

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...

330

40 CFR 52.2059 - Control strategy: Particulate matter.  

Code of Federal Regulations, 2013 CFR

...particulate emissions, alternative control measures, and to develop and implement...associated reasonably available control measures, a reasonable further progress...associated reasonably available control measures, a reasonable further...

2013-07-01

331

Control of particulate processes: Recent results and future challenges  

Microsoft Academic Search

This paper provides a discussion of the existing results on control of particulate processes using population balance models and presents an overview of future research directions in this field in the context of chemical, materials and biological process systems.

Panagiotis D. Christofides; Mingheng Li; Lutz Mädler

2007-01-01

332

MULTIWAVELENGTH TRANSMISSOMETER FOR MEASURING MASS CONCENTRATION OF PARTICULATE EMISSIONS  

EPA Science Inventory

A multiwavelength transmissometer potentially capable of making near-real-time measurements of particulate mass concentration in industrial stacks was developed. A computer program is employed to interpret the transmissometer data and translate the results into mass concentration...

333

40 CFR 60.302 - Standard for particulate matter.  

Code of Federal Regulations, 2011 CFR

... AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Grain Elevators § 60.302 Standard for particulate matter. (a) On and after the 60th day of achieving the maximum...

2011-07-01

334

PARTICULATE HOT GAS STREAM CLEANUP TECHNICAL ISSUES  

SciTech Connect

This quarterly report describes technical activities performed under Contract No. DE-AC21-94MC31160. The analyses of hot gas stream cleanup (HGCU) ashes and descriptions of filter performance studied under Task 1 of this contract are designed to address problems with filter operation that are apparently linked to characteristics of the collected ash. This report reviews the status of the HGCU data bank of ash and char characteristics, including the interactive querying of measured particulate properties. Task 1 plans for the remainder of the project include completion and delivery of the HGCU data bank, and issuance of a comprehensive final report on activities conducted under Task 1. Task 2 of this project concerns the testing and failure analyses of new and used filter elements and filter materials. Task 2 work during the past quarter included preliminary testing of two materials. One material tested was the soft candle filter manufactured by CGC and supplied by ABB. The other material was N610/mullite manufactured by Albany International (AIT).

D.H. Pontius

1999-08-30

335

Gene-particulate matter-health interactions  

SciTech Connect

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.

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

336

Airborne particulate matter and spacecraft internal environments  

NASA Technical Reports Server (NTRS)

Instrumentation, consisting of a Shuttle Particle Sampler (SPS) and a Shuttle Particle Monitor (SPM), has been developed to characterize the airborne particulate matter in the Space Shuttle cabin during orbital flight. The SPS size selectively collects particles in four size fractions (0-2.5, 2.5-10, 10-100, and greater than 100 microns) which are analyzed postflight for mass concentration and size distribution, elemental composition, and morphology. The SPM provides a continuous record of particle concentration through photometric light scattering. Measurements were performed onboard Columbia, OV-102, during the flight of STS-32 in January 1990. No significant changes were observed in the particle mass concentration, size distribution, or chemical composition in samples collected during flight-day 2 and flight-day 7. The total mass concentration was 56 microg/cu cm with approximately half of the particles larger than 100 microns. Elemental analysis showed that roughly 70 percent of the particles larger than 2.5 microns were carbonaceous with small amounts of other elements present. The SPM showed no temporal or spatial variation in particle mass concentration during the mission.

Liu, Benjamin Y. H.; Rubow, Kenneth L.; Mcmurry, Peter H.; Kotz, Thomas J.; Russo, Dane

1991-01-01

337

Particulate matter air pollution and atherosclerosis.  

PubMed

Particulate matter (PM) air pollution less than 2.5 microm in diameter (PM(2.5)), which is now an all-pervading element of modern-day society, is associated with heightened cardiovascular morbidity and mortality. Not only can short-term PM(2.5) exposure trigger acute cardiovascular events, but longer-term exposure over years augments cardiovascular risk to an even greater extent. One biological mechanism capable of explaining this observation is that chronic exposure may promote the progression and vulnerability of atherosclerotic plaques. Indeed, recent epidemiologic studies have demonstrated an association between ambient PM(2.5) exposure and the presence or extent of atherosclerosis in humans. Several animal experiments have provided corroborating evidence that chronic exposures in fact do enhance the progression and perhaps vulnerability of atherosclerotic lesions. Due to the billions of people continually exposed to PM(2.5), the long-term pro-atherosclerotic effects of this ubiquitous air pollutant are likely to be of enormous and growing global public health importance. PMID:20617466

Brook, Robert D; Rajagopalan, Sanjay

2010-09-01

338

Atmospheric particulates in a semi-rural environment  

E-print Network

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... IMPORTANT FOR: NOMENCLATURE AITKEN PARTICLES PARTICLES GIANT PARTICLES ATMOSPHERIC ELECTRICITY SMALL IONG LARGE IOUS ATMOSPHERIC OPTICS HAZE PARTICLES CLOU 0 PHYSICS ACTIVE CONDENSATION NUCLEI ATMOSPHERIC CHEMISTRY PARTICLES WHICH...

Klein, Thomas Kelly

2012-06-07

339

Particulate-removal system upgraded with pulse-jet baghouse  

SciTech Connect

A pulse-jet baghouse installed on a flue gas side-stream enhanced the performance of a small precipitator on Philadelphia Electric Co.'s Cromby unit 1 and enabled it to meet particulate standards. Pulse-jet baghouses have a gentle cleaning action that prolongs fabric life as well as improving particulate removal efficiency to the required 90%. Details of the baghouse design and operation are given. 2 figures. (DCK)

Ingram, T.

1983-08-01

340

Development and evaluation of personal respirable particulate sampler (PRPS)  

Microsoft Academic Search

This paper presents the development, laboratory evaluation, and field tests of a personal respirable particulate sampler (PRPS). The PRPS is designed as a personal sampling system to collect particulate matter (PM0.5, PM1.0, PM2.5, PM4.5, and PM10) and gaseous pollutants, including O3, SO2, and NO2. It operates at a flow rate of 5.0LPM and consists of five selectable impaction stages (with

Seung Joo Lee; Philip Demokritou; Petros Koutrakis; Juana M. Delgado-Saborit

2006-01-01

341

Multichannel simulation of regeneration in honeycomb monolithic diesel particulate filters  

Microsoft Academic Search

In recent years advanced computational tools of diesel particulate filter (DPF) regeneration have been developed to assist in the systematic and cost-effective optimization of next generation particulate trap systems.In the present study, we employ a previously validated, state-of-the-art multichannel DPF simulator to study the regeneration process over the entire spatial domain of the filter. Particular attention is placed on identifying

Margaritis Kostoglou; Paraskevi Housiada; Athanasios G. Konstandopoulos

2003-01-01

342

Zone heated inlet ignited diesel particulate filter regeneration  

SciTech Connect

An exhaust system that processes exhaust generated by an engine is provided. The system includes: a particulate filter (PF) that is disposed downstream of the engine and that filters particulates from the exhaust; and a grid that includes electrically resistive material that is segmented by non-conductive material into a plurality of zones and wherein the grid is applied to an exterior upstream surface of the PF.

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

2012-06-26

343

Characterization of the Winter Midwestern Particulate Nitrate Bulge  

Microsoft Academic Search

A previously unobserved multi-state region of elevated particulate nitrate concentration was detected as a result of the expansion of the Interagency Monitoring of Protected Visual Environments (IMPROVE) network of remote-area particulate matter (PM) speciation monitoring sites into the midwestern United States that began in 2002. Mean winter ammonium nitrate concentrations exceed 4 ?g\\/m in a region centered in Iowa, which

Marc L. Pitchford; Richard L. Poirot; Bret A. Schichtel; William C. Malm; Warren White; Krystyna Trzepla-Nabaglo; Paul Wakabayashi; Charles McDade; Ann Dillner; Hege Indresand; Gavin McMeeking; Sonia Kreidenweis; Ezra Levin; Christian Carrico; Derek Day; Jeffrey Collett; Taehyoung Lee; Amy Sullivan; Suresh Raja; Patricia Brewer; Tom Moore; Mark Green; Shobha Kondragunta; Pubu Ciren; Chuanyu Xu; Delbert Eatough; Robert Farber; Marco Rodriguez; Michael Barna

2009-01-01

344

Exposure to Particulate Hexavalent Chromium Exacerbates Allergic Asthma Pathology  

PubMed Central

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. PMID:22178736

Schneider, Brent C.; Constant, Stephanie L.; Patierno, Steven R.; Jurjus, Rosalyn A.; Ceryak, Susan M.

2011-01-01

345

Size- and structure-dependent toxicity of silica particulates  

NASA Astrophysics Data System (ADS)

Nano- and micro-particulates firmly attach with the surface of various biological systems. In some chronic pulmonary disease such as asbestosis and silicosis, causative particulates will induce chronic inflammatory disorder, followed by poor prognosis diseases. However, nano- and micro-scale specific toxicity of silica particulates is not well examined enough to recognize the risk of nano- and micro-particulates from the clinical aspect. To clarify the effect of the size and structure of silica particulates on the cellular damage and the biological response, we assessed the cytotoxicity of the various kinds of silica particles including amorphous and crystalline silica, in mouse alveolar macrophage culture, focusing on the fibrotic and inflammatory response. Our study showed that the cytotoxicity, which depends on the particle size and surface area, is correlated with their inflammatory response. By contrast, production of TGF-?, which is one of the fibrotic agents in lung, by addition of crystal silica was much higher than that of amorphous silica. We conclude that fibrosis and inflammation are induced at different phases and that the size- and structure-differences of silica particulates affect the both biological responses, caused by surface activity, radical species, and so on.

Hanada, Sanshiro; Miyaoi, Kenichi; Hoshino, Akiyoshi; Inasawa, Susumu; Yamaguchi, Yukio; Yamamoto, Kenji

2011-03-01

346

Estimation of particulate matter from simulation and measurements  

NASA Astrophysics Data System (ADS)

The particulate matter is a typical indicator of small particles in the atmosphere. In addition to providing impacts on climate and environment, these small particles can bring adverse effects on human health. Then an accurate estimation of particulate matter is an urgent subject. We set up SPM sampler attached to our AERONET (Aerosol Robotics Network) station in urban city of Higashi-Osaka in Japan. The SPM sampler provides particle information about the concentrations of various SPMs (e.g., PM10 and PM2.5) separately. The AEROENT program is world wide ground based sunphotometric observation networks by NASA and provides the spectral information about aerosol optical thickness (AOT) and Angstrom exponent (?). Simultaneous measurements show that a linear correlation definitely exists between AOT and PM2.5. These results indicate that particulate matter can be estimated from AOT. However AOT represents integrated values of column aerosol amount retrieved from optical property, while particulate matter concentration presents in-situ aerosol loading on the surface. Then simple way using linear correlation brings the discrepancy between observed and estimated particulate matter. In this work, we use cluster information about aerosol type to reduce the discrepancy. Our improved method will be useful for retrieving particulate matter from satellite measurements.

Nakata, Makiko; Nakano, Tomio; Okuhara, Takaaki; Sano, Itaru; Mukai, Sonoyo

2011-11-01

347

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...

348

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...

349

Thorium-particulate matter interaction. Thorium complexing capacity of oceanic particulate matter: Theory  

SciTech Connect

The interaction between thorium and oceanic particulate matter was examined experimentally by using chemical equilibrium techniques. Thorium reacts quantitatively with the organic binding site of Particulate Matter (PM) in 0.1 mol/L HCl solution by complexation, which is equilibrated within 34 h. According to mass balance analysis, thorium forms a 1:1 complex with the organic binding site in PM, whose conditional stability constant is 10[sup 6.6] L/mol. The Th adsorption ability is present even in 6.9 mol/L HCl solution although the amount of Th adsorption decreases with increasing acidity in the solution. Interferences to Th adsorption by Fe(III) suggests that other metals cannot react with PM in more than 0.1 mol/L HCl solutions when concentrations of other metals are the same level of Th. The competitive reaction between Th and Fe(III) occurs in higher Fe concentrations, which means that the organic binding site is nonspecific for Th. A vertical profile of Th complexing capacity of PM in the western North Pacific is characterized; that is, the Th complexing capacity shows a surface maximum and decreases rapidly with depth.

Hirose, Katsumi; Tanque, Eiichiro (Meterological Research Institute, Tsukuba, Ibaraki (Japan))

1994-01-01

350

Microwave-Regenerated Diesel Exhaust Particulate Filter  

SciTech Connect

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.)

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

2001-03-05

351

Photochemical reactions of particulate organic matter  

NASA Astrophysics Data System (ADS)

Organic carbon contained in suspended, coastal marine sediments photochemically dissolves under high doses of artificial sunlight in the laboratory, suggesting that sunlight might induce large changes in the form and fate of organic matter present in suspended particles along turbid, low-latitude coastlines. The primary goal of the work presented here was to develop a quantitative method of predicting the particulate organic carbon (POC) "photodissolution" rate in the coastal waters of Louisiana near the deltas of the Mississippi and Atchafalaya rivers. Pursuit of this objective required measurements of the reaction rate and apparent quantum yield, determination of sediment light absorption properties, and development of a novel method to retrieve the optical properties of coastal water from remotely-sensed reflectance measurements. This dissertation first describes dissolved inorganic carbon (DIC) production and oxygen consumption accompanying photodissolution. The ratio of DIC production to O2 consumption was lower for POC than in previously-described reactions of colored dissolved organic matter (CDOM), suggesting greater photochemical incorporation of oxygen into organic matter. Particle light absorption properties control, in part, the rate of photodissolution. Absorption coefficients of suspended sediment samples from the study region are a weak function of organic carbon content but a strong function of reducible iron content. Photodissolution rate measurements and radiative transfer modeling were used to determine the wavelength-dependent apparent quantum yield for the reaction and to constrain the temperature dependence and sample composition-induced variability in the rate. Initial photodissolution rates scaled linearly with the reducible iron content of sediments but the rate was independent of composition over longer periods. High spatial-resolution optical properties of study region waters were obtained from a novel satellite reflectance inversion calibrated using the local mass-normalized optical properties of suspended sediments. Lab-based photodissolution rate measurements were scaled to match field optical conditions determined from available satellite observations. Empirical relationships between local weather and the satellite-based photodissolution predictions allowed estimates of rates on days without satellite imagery. Annually-integrated rates were small relative to river POC inputs, but results suggested photodissolution rates similar in magnitude to CDOM photoreactions.

Estapa, Margaret L.

352

Particulate Hot Gas Stream Cleanup Technical Issues  

SciTech Connect

This is the fifteenth quarterly report describing the activities performed under Contract No. DE-AC21-94MC31160. The analyses of Hot Gas Stream Cleanup (HGCU) ashes and descriptions of filter performance studied under this contract are designed to address problems with filter operation that are apparently linked to characteristics of the collected ash. Task 1 is designed to generate a data bank of the key characteristics of ashes collected from operating advanced particle filters (APFs) and to relate these ash properties to the operation and performance of these filters and their components. APF operations have also been limited by the strength and durability of the ceramic materials that have served as barrier filters for the capture of entrained HGCU ashes. Task 2 concerns testing and failure analyses of ceramic filter elements currently used in operating APFs and the characterization and evaluation of new ceramic materials. Task 1 research activities during the past quarter included characterizations of samples collected during a site visit on May 18 to the Department of Energy / Southern Company Services Power Systems Development Facility (PSDF) and a particulate sample collected in the Westinghouse filter at Sierra Pacific Power Company?s Piñon Pine Power Project. Analysis of this Piñon Pine sample is ongoing: however, this report contains the results of analyses completed to date. Significant accomplishments were achieved on the HGCU data bank during this reporting quarter. The data bank was prepared for presentation at the Advanced Coal-Based Power and Environmental Systems ?98 Conference scheduled for July, 1998. Task 2 work during the past quarter consisted of testing two Dupont PRD-66C candle filters, one McDermott ceramic composite candle filter, one Blasch 4-270 candle filter, and one Specific Surface cordierite candle filter. Tensile and thermal expansion testing is complete and the rest of the testing is in progress. Also, some 20-inch long Dupont PRD-66C, McDermott ceramic composite, and Westinghouse Techniweave candle filters have been received for testing after their exposure to the gasification environment. One as-manufactured and one exposed element was received of each material and specimens are currently being machined from these candles.

None

1998-08-31

353

[Determination of particulate matter in small volume antibiotic injections].  

PubMed

Amounts of particulate matter present in 17 small volume antibiotic injections marketed in Japan were determined using light obscuration particle analyzer (HIAC). The vial volume range of each batch of product was 7-20 ml, and each vial contained 1 g as antibiotic potency. In 4 products, contents of particles between 2.5 and 10 microns in diameter were counted 2,000-7,000 per vial, and particles in other products were counted less than 2,000 per vial. Numbers of particles greater than or equal to 10 microns in diameter were much less than the USP XXI criteria for particulate matter in small volume injections. The product of the highest counts for particles between 10 and 25 microns in diameter showed counts amounted to 0.13% of the USP XXI criteria. In the 25-50 microns particulate diameter range, particulate matters were detected only in 2 products, and they were less than 0.2% of the USP XXI criteria. Particles over 50 microns in diameter were not detected in any products. These results showed that 17 small volume antibiotic injections marketed in Japan had good qualities regarding contents of particulate matter. PMID:2746842

Niizeki, M; Tanno, K

1989-03-01

354

Particulate size distribution cascade analyzer for spacecraft contamination monitoring  

NASA Technical Reports Server (NTRS)

A cascade particulate analyzer was developed for nearly real time measurement of the contaminating particulate size distribution in the spacecraft interior ambient environment and as a real time total impacting particulate mass monitor under vacuum conditions. The analyzer has four stages, the first stage is a basic 10 MHz quartz crystal microbalance used widely on spacecraft (such as Skylab) for contamination monitoring purposes. In this application the front sensing crystal is coated with a low vapor pressure adhesive grease which captures impacting particles. This first stage has a wide viewing angle and measures total particulate mass impacting the crystal while the unit is exposed to the vacuum environment. The remaining three states form an aerodynamic impaction cascade with individual quartz crystal microbalances at each stage acting as accumulated mass sensing elements. These three stages thus give relative mass distribution of particulates in three ranges, particles having effective diameter greater than 5 micron, particles between 1 and 5 micron diameter and particles 0.3 to 1 micron diameter.

Wallace, D. A.; Chuan, R. L.

1975-01-01

355

Major components of China's anthropogenic primary particulate emissions.  

SciTech Connect

This paper presents the first comprehensive estimates of particulate emissions in China by size distribution and major components. Using a technology-based emission inventory approach, we are able to classify particulate emissions into three size ranges, TSP, PM{sub 10} and PM{sub 2.5}, and identify the contributions of black carbon (BC), organic carbon (OC), Ca and Mg. Total particulate emissions are estimated to be 27.4 Tg for the year 2001, of which 17.8 Tg are PM{sub 10} and 12.7 Tg are PM{sub 2.5}. Industrial processes are the major sources of particles over all three size ranges, but residential biofuel use and transportation sources become increasingly important for PM{sub 10} and PM{sub 2.5}. The industrialized coastal provinces, such as Shandong, Jiangsu and Hebei, are the major sources of particulate emissions. The industrialized and developing regions show different characteristic emission ratios of PM{sub 2.5}/TSP, (BC+OC)/PM{sub 2.5} and (Ca+Mg)/TSP. In the future, we can expect significant reductions in primary particulate emissions and major changes in the patterns of size and species.

Zhang, Q.; Streets, D. G.; He, K.; Klimont, Z.; Decision and Information Sciences; Tsinghua Univ.; International Inst. for Applied Systems Analysis

2007-10-01

356

Ceramic filters for removal of particulates from hot gas streams  

SciTech Connect

The primary goal is to demonstrate the performance of a new ceramic filter in removing particulate matter from hot gas streams produced in advanced coal conversion processes. The specific objectives are threefold: (1) Development of full size ceramic filters suitable for hot gas filtration; (2) Demonstration of ceramic filters in long term (ca. 1000 hrs) field trials; and (3) Development of full-scale hot gas filter system designs and costs. To date, field tests of the ceramic filter for particulate removal have been conducted at seven sites on a variety of gas streams and under a variety of test conditions. In general, the following performance characteristics have been observed: 1. Filtration face velocity (equivalent to an air to cloth ratio'') for flue gas tests is comparable to that for pulse jet bags operating at the same pressure drop. In hot gas tests, flow-pressure drop characteristics have been observed to be comparable to those for other ceramic filters. 2. Complete regeneration by a simple backpulse technique is achieved; i.e., no increase in clean filter resistance over repetitive cycles is observed. 3. No plugging of the filter passageways by badly caking particulates is observed. 4. Essentially complete particulate removal, including submicron particulate matter, is achieved.

Goldsmith, R.L.

1992-01-01

357

Ceramic filters for removal of particulates from hot gas streams  

SciTech Connect

The primary goal is to demonstrate the performance of a new ceramic filter in removing particulate matter from hot gas streams produced in advanced coal conversion processes. The specific objectives are threefold: (1) Development of full size ceramic filters suitable for hot gas filtration; (2) Demonstration of ceramic filters in long term (ca. 1000 hrs) field trials; and (3) Development of full-scale hot gas filter system designs and costs. To date, field tests of the ceramic filter for particulate removal have been conducted at seven sites on a variety of gas streams and under a variety of test conditions. In general, the following performance characteristics have been observed: 1. Filtration face velocity (equivalent to an ``air to cloth ratio``) for flue gas tests is comparable to that for pulse jet bags operating at the same pressure drop. In hot gas tests, flow-pressure drop characteristics have been observed to be comparable to those for other ceramic filters. 2. Complete regeneration by a simple backpulse technique is achieved; i.e., no increase in clean filter resistance over repetitive cycles is observed. 3. No plugging of the filter passageways by badly caking particulates is observed. 4. Essentially complete particulate removal, including submicron particulate matter, is achieved.

Goldsmith, R.L.

1992-11-01

358

Particulates from PTFE degradation in terrestrial and microgravity.  

PubMed

It has recently been discovered that the ultrafine particles generated during polymer thermodegradation are a major health hazard, owing to their unique pathway of processing in the lung. This hazard in manned spacecraft is poorly understood because the particulate products of polymer thermodegradation are generated under low gravity conditions. Particulates generated from the degradation of polytetrafluoroethylene (PTFE), insulation coating for 20 AWG copper wire (representative of spacecraft application) under intense current overload, were studied in terrestrial gravity and microgravity. Microgravity tests were done in a 1.2-s drop tower at the Colorado School of Mines. Thermophoretic sampling was used for particulate collection. Transmission electron microscopy (TEM) was used to examine the smoke particulates. The pigmentation of PTFE insulation seems to have an overwhelming effect on size, shape and morphology of the particulate. Nanometer-sized particles were found in all cases, but their extent of aggregation and size distribution were dependent on both PTFE pigmentation and gravity; higher aggregation occurred in low gravity. Four different color insulations (viz. white, black, red and yellow) were studied. PMID:10332948

Srivastava, R; McKinnon, J T; Todd, P

1999-05-01

359

Semivolatile Particulate Organic Material Southern Africa during SAFARI 2000  

NASA Technical Reports Server (NTRS)

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.

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

2005-01-01

360

Particulate matter as an amplifier for astronomical light pollution  

NASA Astrophysics Data System (ADS)

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.

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

2014-11-01

361

Multiple transfers of particulates and their dissemination within contact networks.  

PubMed

The application of social network theory to understanding the nature and occurrence of multiple transfers of particulate evidence is demonstrated to be a useful means of identifying the prevalence of such transfers. Four experimental scenarios of increasing complexity empirically demonstrate that this trace particulate evidence exhibits behaviour in accordance with that previously identified for hair and fibre evidence. However, the utilisation of social network concepts is demonstrated to add valuable insights into the behaviour of this form of evidence and is shown to be a useful tool in highlighting the complexity of evidence dynamics. The identification of the networks within which trace evidence is transferred has implications for the robust interpretation of particulate evidence during the process of crime reconstruction. PMID:22325909

French, J C; Morgan, R M; Baxendell, P; Bull, P A

2012-03-01

362

Method for dispersing catalyst onto particulate material and product thereof  

DOEpatents

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.

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

1992-01-01

363

Particulate Emissions Hazards Associated with Fueling Heat Engines  

NASA Technical Reports Server (NTRS)

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.

Hendricks, Robert C.; Bushnell, Dennis M.

2010-01-01

364

Apparatus and method for void/particulate detection  

DOEpatents

Apparatus and method for detecting voids and particulates in a fluid within a containing vessel. A diffuse ultrasonic signal is coupled into the fluid by a first transducer and the portion of the ultrasonic signal transmitted through the fluid is detected by a second transducer. The received signal is analyzed by a processor to determine the void fraction of the fluid responsive to the attenuation of the received ultrasonic signal. In addition, voids and particulates are detected by evaluating the increase in side-band energy of the received signal.

Claytor, Thomas N. (Woodridge, IL); Ockert, Carl E. (Vienna, VA); Randall, Richard (Canoga Park, CA)

1987-01-01

365

40 CFR Table 2 to Subpart Ddddd of... - Operating Limits for Boilers and Process Heaters With Particulate Matter Emission Limits  

Code of Federal Regulations, 2012 CFR

...Boilers and Process Heaters With Particulate Matter Emission Limits 2 Table 2 to Subpart...Boilers and Process Heaters With Particulate Matter Emission Limits As stated in § 63...compliance with applicable particulate matter emission limits using . . . You...

2012-07-01

366

40 CFR Table 2 to Subpart Ddddd of... - Operating Limits for Boilers and Process Heaters With Particulate Matter Emission Limits  

Code of Federal Regulations, 2011 CFR

...Boilers and Process Heaters With Particulate Matter Emission Limits 2 Table 2 to Subpart...Boilers and Process Heaters With Particulate Matter Emission Limits As stated in § 63...compliance with applicable particulate matter emission limits using . . . You...

2011-07-01

367

40 CFR Table 2 to Subpart Ddddd of... - Operating Limits for Boilers and Process Heaters With Particulate Matter Emission Limits  

Code of Federal Regulations, 2010 CFR

...Boilers and Process Heaters With Particulate Matter Emission Limits 2 Table 2 to Subpart...Boilers and Process Heaters With Particulate Matter Emission Limits As stated in § 63...compliance with applicable particulate matter emission limits using . . . You...

2010-07-01

368

40 CFR 52.226 - Control strategy and regulations: Particulate matter, San Joaquin Valley and Mountain Counties...  

...strategy and regulations: Particulate matter, San Joaquin Valley and Mountain Counties...strategy and regulations: Particulate matter, San Joaquin Valley and Mountain Counties...Air Quality Standards for particulate matter: (1) Kings County APCD....

2014-07-01

369

40 CFR 60.48b - Emission monitoring for particulate matter and nitrogen oxides.  

Code of Federal Regulations, 2010 CFR

... Emission monitoring for particulate matter and nitrogen oxides. 60.48b Section... Emission monitoring for particulate matter and nitrogen oxides. ...Measurement Policy Group (D243-02), Research Triangle Park, NC 27711. This...

2010-07-01

370

40 CFR 60.48b - Emission monitoring for particulate matter and nitrogen oxides.  

Code of Federal Regulations, 2012 CFR

... Emission monitoring for particulate matter and nitrogen oxides. 60.48b Section... Emission monitoring for particulate matter and nitrogen oxides. ...Measurement Policy Group (D243-02), Research Triangle Park, NC 27711. This...

2012-07-01

371

40 CFR 60.47c - Emission monitoring for particulate matter.  

Code of Federal Regulations, 2010 CFR

... Emission monitoring for particulate matter. 60.47c Section 60.47c Protection... Emission monitoring for particulate matter. (a) Except as provided...Measurement Policy Group (D243-02), Research Triangle Park, NC 27711. This...

2010-07-01

372

40 CFR 60.48b - Emission monitoring for particulate matter and nitrogen oxides.  

Code of Federal Regulations, 2013 CFR

... Emission monitoring for particulate matter and nitrogen oxides. 60.48b Section... Emission monitoring for particulate matter and nitrogen oxides. ...Measurement Policy Group (D243-02), Research Triangle Park, NC 27711. This...

2013-07-01

373

40 CFR 60.47c - Emission monitoring for particulate matter.  

Code of Federal Regulations, 2013 CFR

... Emission monitoring for particulate matter. 60.47c Section 60.47c Protection... Emission monitoring for particulate matter. (a) Except as provided...Measurement Policy Group (D243-02), Research Triangle Park, NC 27711. This...

2013-07-01

374

40 CFR 60.48b - Emission monitoring for particulate matter and nitrogen oxides.  

Code of Federal Regulations, 2011 CFR

... Emission monitoring for particulate matter and nitrogen oxides. 60.48b Section... Emission monitoring for particulate matter and nitrogen oxides. ...Measurement Policy Group (D243-02), Research Triangle Park, NC 27711. This...

2011-07-01

375

40 CFR 60.47c - Emission monitoring for particulate matter.  

Code of Federal Regulations, 2012 CFR

... Emission monitoring for particulate matter. 60.47c Section 60.47c Protection... Emission monitoring for particulate matter. (a) Except as provided...Measurement Policy Group (D243-02), Research Triangle Park, NC 27711. This...

2012-07-01

376

40 CFR 60.47c - Emission monitoring for particulate matter.  

Code of Federal Regulations, 2011 CFR

... Emission monitoring for particulate matter. 60.47c Section 60.47c Protection... Emission monitoring for particulate matter. (a) Except as provided...Measurement Policy Group (D243-02), Research Triangle Park, NC 27711. This...

2011-07-01

377

COPPER-DEPENDENT INFLAMMATION AND NUCLEAR FACTOR-KB ACTIVATION BY PARTICULATE AIR POLLUTION  

EPA Science Inventory

Particulate air pollution causes increased cardiopulmonary morbidity and mortality, but the chemical determinants 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 ...

378

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

Code of Federal Regulations, 2012 CFR

...2012-07-01 2011-07-01 true Liquid, suspended particulate, and solid phases...MATERIALS Definitions § 227.32 Liquid, suspended particulate, and solid phases...the purposes of these regulations, the liquid phase of a material, subject...

2012-07-01

379

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

...2014-07-01 2014-07-01 false Liquid, suspended particulate, and solid phases...MATERIALS Definitions § 227.32 Liquid, suspended particulate, and solid phases...the purposes of these regulations, the liquid phase of a material, subject...

2014-07-01

380

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 ...

381

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

E-print Network

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...

Cochran, Emma Mary

2013-07-31

382

Worker exposure to chemical agents in the manufacture of rubber tires and tubes: particulates.  

PubMed

The Occupational Health Studies Group industrial hygiene studies at a group of 14 tire and tube manufacturing plants chosen to represent a cross-section of the industry include numerous evaluations of potential exposure to airborne particulate matter. Results of these environmental particulate sampling studies are reported by plant and by occupational groups within plants. High volume, open face and cyclone samplers were employed to evaluate both personnel and area particulate concentrations. The concentrations of particulates yielded by high volume and open face total particulate samplers are compared with those of comparison samples of respirable material. Personnel samples of particulates are compared with general air samples taken in the same work areas. An overall review and comparison is given of particulate exposures to workers in various occupational title groups where particulate materials are released to the air from processes or operations. PMID:7395731

Williams, T M; Harris, R L; Arp, E W; Symons, M J; Van Ert, M D

1980-03-01

383

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

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Control strategy and regulations: Particulate matter...CONTINUED) Guam § 52.2678 Control strategy and regulations: Particulate matter...an emissions increase, and a control strategy demonstration has not been...

2011-07-01

384

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

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Control strategy and regulations: Particulate matter...CONTINUED) Guam § 52.2678 Control strategy and regulations: Particulate matter...an emissions increase, and a control strategy demonstration has not been...

2010-07-01

385

40 CFR 52.933 - Control Strategy: Sulfur oxides and particulate matter.  

Code of Federal Regulations, 2011 CFR

...Environment 3 2011-07-01 2011-07-01 false Control Strategy: Sulfur oxides and particulate matter. 52.933 Section...PROMULGATION OF IMPLEMENTATION PLANS Kentucky § 52.933 Control Strategy: Sulfur oxides and particulate matter. (a)...

2011-07-01

386

77 FR 33002 - Proposed Extension of Existing Information Collection; Health Standards for Diesel Particulate...  

Federal Register 2010, 2011, 2012, 2013

...Information Collection; Health Standards for Diesel Particulate Matter Exposure (Underground...prevention of injuries in coal or other mines. Diesel particulate matter (DPM) is a probable...consists of tiny particles present in diesel engine exhaust that can readily...

2012-06-04

387

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...

388

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...

389

78 FR 23524 - Approval and Promulgation of Air Quality Implementation Plans; Indiana; Particulate Matter...  

Federal Register 2010, 2011, 2012, 2013

...Implementation Plans; Indiana; Particulate Matter Ambient Air Quality Standards...Implementation Plan (SIP) for particulate matter under the Clean Air Act. This...Federally regulated criteria pollutant definitions and...

2013-04-19

390

78 FR 23492 - Approval and Promulgation of Air Quality Implementation Plans; Indiana; Particulate Matter Air...  

Federal Register 2010, 2011, 2012, 2013

...Implementation Plans; Indiana; Particulate Matter Air Quality Standards AGENCY...Implementation Plan (SIP) for particulate matter under the Clean Air Act (CAA...Federally regulated criteria pollutant definitions and...

2013-04-19

391

42 CFR 84.170 - Non-powered air-purifying particulate respirators; description.  

Code of Federal Regulations, 2012 CFR

...Respirators § 84.170 Non-powered air-purifying particulate respirators...description. (a) Non-powered air-purifying particulate respirators...wearer's negative inhalation pressure to draw the ambient air through the air-purifying...

2012-10-01

392

42 CFR 84.170 - Non-powered air-purifying particulate respirators; description.  

Code of Federal Regulations, 2011 CFR

...Respirators § 84.170 Non-powered air-purifying particulate respirators...description. (a) Non-powered air-purifying particulate respirators...wearer's negative inhalation pressure to draw the ambient air through the air-purifying...

2011-10-01

393

42 CFR 84.170 - Non-powered air-purifying particulate respirators; description.  

Code of Federal Regulations, 2013 CFR

...Respirators § 84.170 Non-powered air-purifying particulate respirators...description. (a) Non-powered air-purifying particulate respirators...wearer's negative inhalation pressure to draw the ambient air through the air-purifying...

2013-10-01

394

42 CFR 84.170 - Non-powered air-purifying particulate respirators; description.  

Code of Federal Regulations, 2010 CFR

...Respirators § 84.170 Non-powered air-purifying particulate respirators...description. (a) Non-powered air-purifying particulate respirators...wearer's negative inhalation pressure to draw the ambient air through the air-purifying...

2010-10-01

395

STATUS AND PROGRESS IN PARTICULATE MATTER FORECASTING: INITIAL APPLICATION OF THE ETA- CMAQ FORECAST MODEL  

EPA Science Inventory

This presentation reviews the status and progress in forecasting particulate matter distributions. The shortcomings in representation of particulate matter formation in current atmospheric chemistry/transport models are presented based on analyses and detailed comparisons with me...

396

An Overview of Particulate Matter and its Cost-efficient Evaluation  

E-print Network

Ambient particulate matter (PM) is a complex mixture of sizes and types of particles. Exposure to airborne particulate matter adversely affects human health. In this paper, sources of particles are summarized, and epidemiological and toxicological...

Zhang, F.; Zhang, G.; Zhang, Q.

2006-01-01

397

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...

398

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...

399

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...

400

Discrimination of atmospheric particulate matter sources with magnetic methods  

Microsoft Academic Search

The harmful effects of anthropogenically derived particulate matter (PM) on human health have attracted the attention of environmental research in recent years. Particles < 10 mu m (PM10) are of special interest because they can be inhaled deeply into the lung. Since magnetic minerals are common in natural and anthropogenic PM, magnetic bulk properties have been used to characterise urban

S. Spassov; R. Egli; F. Heller; D. K. Nourgaliev

2003-01-01

401

EFFECTS OF PARTICULATE AIR POLLUTION ON ASTHMATIC SUBJECTS  

EPA Science Inventory

While much remains to be understood, individuals with respiratory disease appear to be affected by high levels of air pollution as indicated by subjective reports, clinic and hospital visits, and morbidity. Suspended particulates make up a substantial part of urban air pollution,...

402

Numerical analysis of particulate jet generated by free falling particles  

Microsoft Academic Search

This paper is concerned with the numerical simulation of the particulate jet generated by solid particles falling from a slit orifice into an unbounded quiescent air. A two-dimensional vortex method, proposed for the analysis of particle-laden free turbulent flow in prior papers, is employed for the simulation. The falling particles induce complicated air flow involving eddies with a wide variety

Tomomi Uchiyama

2004-01-01

403

40 CFR 230.21 - Suspended particulates/turbidity.  

...particulates in the water column for varying lengths of time. These new levels may reduce light penetration and lower the rate of photosynthesis and the primary productivity of an aquatic area if they last long enough. Sight-dependent species may suffer reduced...

2014-07-01

404

Turkish Primary Students' Conceptions about the Particulate Nature of Matter  

ERIC Educational Resources Information Center

This study was conducted to determine 4th, 5th, and 6th grade primary students' conceptions about the particulate nature of matter in daily-life events. Five questions were asked of students and interviews were used to collect data. The interviews were conducted with 12 students, four students from each grade, after they finished the formal…

Ozmen, Haluk

2011-01-01

405

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...

406

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...

407

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, ...

408

Thermal radiation in particulate media with dependent and independent scattering  

Microsoft Academic Search

The present work gives an overview of the existing knowledge of radiative heat transfer in particulate media. Special emphasis is given to the proper usage of realistic scattering characteristics of particles. It begins with an introduction of the basic formulation for radiative heat transfer with scattering. This is followed by a discussion on the classification of different scattering environments such

C. L. Tien; B. L. Drolen

1987-01-01

409

ATOC 3500/CHEM 3151 Spring 2014 Particulate Mass and Visibility  

E-print Network

particle has a surface area of 4 x 10-9 cm2 . Since there are 1010 particles in a cubic meter of air , the total scattering cross section would be 4 x 109 m2 in one m3 of air for particles of this size to condense and form small particles (particulate matter, or PM). As we have seen in previous homeworks

Toohey, Darin W.

410

Breakup of a droplet in a particulate shear flow  

Microsoft Academic Search

A numerical simulation using a Distributed-Lagrange-Multiplier-based computational method is conducted in order to simulate the breakup of a droplet in a particulate shear flow. The results show that the presence of particles strongly affects droplet deformation and may, in some cases, facilitate droplet breakup. In this problem, in addition to the capillary number and viscosity ratio, the particle volume fraction,

Arezoo Ardekani; Roger Rangel

2008-01-01

411

EDITORIAL: Global impacts of particulate matter air pollution  

Microsoft Academic Search

Even in well-studied, data-rich regions of the United States and Europe, understanding ambient particulate matter (PM, aka aerosols) remains a challenge. Atmospheric aerosols exhibit chemical heterogeneity, spatial and seasonal variability, and result in a wide range of health impacts (mortality, respiratory disease, cardiovascular disease, eye irritation, and others). In addition, aerosols play an important role in climate, exerting warming effects

Michelle L. Bell; Tracey Holloway

2007-01-01

412

Suspended particulate matter (SPM) in rivers: empirical data and models  

Microsoft Academic Search

This work uses three data-bases to derive the first (as far as we know) operational empirical model to predict concentrations of suspended particulate matter (SPM) in rivers. SPM is a variable of fundamental importance in aquatic sciences. This empirical model is meant to be used as a sub-model in models where the main aim is to predict concentrations of radionuclides,

Lars Håkanson; Maya Mikrenska; Krassimir Petrov; Ian Foster

2005-01-01

413

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...

414

Evaluation of a Direct Personal Coarse Particulate Matter Monitor  

EPA Science Inventory

One aspect of the North Carolina Adult Asthma and Environment study (NCAAES) was to evaluate personal exposures to coarse particulate matter (PM 10-2.5) and their associated variability. As part of this, we examined the ability of a community-based monitor to act as...

415

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...

416

Chemical characterization of particulate emissions from diesel engines: A review  

Microsoft Academic Search

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,

M. Matti Maricq

2007-01-01

417

Effective medium theory for elastic matrix composites containing dispersed particulates  

Microsoft Academic Search

We describe a new, effective medium theory to study the wave propagation and mechanical properties of a composite system with dispersed particulates. One main emphasis here is in formulating the theory and in analyzing the structure of the contribution of the fillers to the elastic response. By constructing the elastic propagator (whose fluid mechanical counterpart is known as the Oseen

Myung S. Jhon; Robert J. Metz; Karl F. Freed

1988-01-01

418

One-dimensional wave propagation in particulate suspensions  

NASA Technical Reports Server (NTRS)

One-dimensional small-amplitude wave motion in a two-phase system consisting of an inviscid gas and a cloud of suspended particles is analyzed using a continuum theory of suspensions. Laplace transform methods are used to obtain several approximate solutions. Properties of acoustic wave motion in particulate suspensions are inferred from these solutions.

Rochelle, S. G.; Peddieson, J., Jr.

1976-01-01

419

Multiple scattering by random particulate media: exact 3D results  

E-print Network

Multiple scattering by random particulate media: exact 3D results Michael I. Mishchenko1* , Li Liu1 theories of radiative transfer and coherent backscattering. Furthermore, we show that even in densely. Skipetrov, eds., Wave Scattering in Complex Media: From Theory to Applications (Springer, Berlin, 2003). 9

420

Turkish Pupils’ Conceptions of the Particulate Nature of Matter  

Microsoft Academic Search

The purpose of this research study is to explore year 6, 8 & 11 (13, 15 and 17 years old respectively) Turkish pupils’ views about the particulate nature of matter within the context of phase changes. About 300 pupils participated in the study. Questionnaires distributed to year 6, 8 and 11 pupils included 6-item open-ended questions about (a) arrangement and movement

Yezdan Boz

2006-01-01

421

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...

422

Distribution of toxic and radiation components in air particulates.  

PubMed

The concentrations of several toxic heavy metals and volatile organic compounds (VOCs) in various types of Hungarian fly-ash fine particulates were investigated by means of instrumental neutron activation analysis, X-ray fluorescence analysis and gas chromatography, coupled with mass spectrometry. Within a power station, particulate samples were taken from the boiler zone (BO), from the electrostatic dust filter chamber (FI) and from the flue-gas at the top of the stack (ST). Enrichment rates of the toxic metals both in FI and ST particulate fractions related to the BO concentrations were calculated to enable the temperature dependence on the adsorption of the toxic components to be studied. In addition, both the total amounts of the VOCs and their partial distributions in accordance with the number of carbon atoms were also studied in fly-ash particulates. From them, 31 organic species were identified and determined. Since Hungarian brown coals have high uranium and thorium contents, the specific radioactivities of the daughter isotopes of both the 232Th and 238U decay series were also measured and are discussed. PMID:8560225

Rausch, H; Sziklai, I L; Borossay, J; Torkos, K; Rikker, T; Zemplén-Papp, E

1995-12-01

423

VAPOR PHASE AND PARTICULATE SELENIUM IN THE MARINE ATMOSPHERE  

Microsoft Academic Search

Particulate and vapor phase significant natural vapor flux of Se from the selenium sampling was conducted in urban and sea surface and land to the atmosphere. In coastal Rhode Island, at a coastal site in laboratory studies using elevated American Samoa, aboard ship in an upwelling concentrations of inorganic selenium, Chau et area near the Peru coast, and at two

Byard W. Mosher; Robert A. Duce

1983-01-01

424

NUCLEATION PHENOMENON IN SiC PARTICULATE REINFORCED MAGNESIUM COMPOSITE  

E-print Network

NUCLEATION PHENOMENON IN SiC PARTICULATE REINFORCED MAGNESIUM COMPOSITE Y. Cai, D. Taplin, M.J. Tan performance of matrix metals and alloys. Most magnesium alloy based MMCs are produced via a casting process into the last freezing interdendritic regions. For magnesium based composites, both particle pushing (or capture

Zhou, Wei

425

PROGRESS OF THE NRMRL'S PARTICULATE MATTER RESEARCH PROGRAM  

EPA Science Inventory

The National Risk Management Research Laboratory's Particulate Matter research program has a goal of producing the scientific research data needed to enhance the development of public policy that protects the public health and the environment from harmful effects due to airborne ...

426

Electrically heated particulate matter filter with recessed inlet end plugs  

DOEpatents

A particulate matter (PM) filter includes filter walls having inlet ends and outlet ends. First adjacent pairs of the filter walls define inlet channels. Second adjacent pairs of the filter walls define outlet channels. Outlet end plugs are arranged in the inlet channels adjacent to the output ends. Inlet end plugs arranged in the outlet channels spaced from the inlet ends.

Gonze, Eugene V. (Pinckney, MI); Ament, Frank (Troy, MI)

2012-02-21

427

A FUNCTIONALLY GRADED PARTICULATE COMPOSITE: PREPARATION, MEASUREMENTS AND FAILURE  

E-print Network

composite is prepared and the spatial gradation of Young's modulus in the functionally graded material (FGM to a new class of materials called functionally graded materials (FGMs). In these, dis- similar materialsA FUNCTIONALLY GRADED PARTICULATE COMPOSITE: PREPARATION, MEASUREMENTS AND FAILURE ANALYSIS R. J

Rousseau, Carl-Ernst

428

40 CFR 60.402 - Standard for particulate matter.  

Code of Federal Regulations, 2012 CFR

... 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...

2012-07-01

429

40 CFR 60.402 - Standard for particulate matter.  

Code of Federal Regulations, 2011 CFR

... 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...

2011-07-01

430

40 CFR 60.402 - Standard for particulate matter.  

Code of Federal Regulations, 2013 CFR

... 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...

2013-07-01

431

40 CFR 60.402 - Standard for particulate matter.  

Code of Federal Regulations, 2010 CFR

... 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...

2010-07-01

432

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...

433

Sources of fine urban particulate matter in Detroit, MI  

Microsoft Academic Search

Data from the speciation trends network (STN) was used to evaluate the amount and temporal patterns of particulate matter originating from local industrial sources and long-range transport at two sites in Detroit, MI: Allen Park, MI, southwest of both Detroit and the areas of heavy industrial activity; Dearborn, MI, located on the south side of Detroit near the most heavily

Amy E. Gildemeister; Philip K. Hopke; Eugene Kim

2007-01-01

434

A POPULATION EXPOSURE MODEL FOR PARTICULATE MATTER: SHEDS-PM  

EPA Science Inventory

The US EPA National Exposure Research Laboratory (NERL) has developed a population exposure and dose model for particulate matter (PM) that will be publicly available in Fall 2002. The Stochastic Human Exposure and Dose Simulation (SHEDS-PM) model uses a probabilistic approach ...

435

On a Representative Volume in the Micromechanics of Particulate Composites  

Microsoft Academic Search

A rectangle filled with closely packed spheres of random size and properties is considered as a micromechanical model of a two-phase particulate composite. A numerical simulation is used to determine the effective mechanical properties of the assembly and their scatter as a function of the number of spheres. It is shown that, in a system with relatively small number of

O. Vinogradov

2001-01-01

436

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...

437

Rotary device for removing particulates from a gas stream  

NASA Technical Reports Server (NTRS)

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.

Collins, Jr., Earl R. (Inventor)

1992-01-01

438

LOCAL AND REGIONAL CONTRIBUTIONS TO URBAN PARTICULATE MATTER  

EPA Science Inventory

The report summarizes the data analysis of two extensive field studies on urban particulate matter, the 1974-77 St. Louis (RAPS) and the July/August 1982 Philadelphia (PAFS) studies. The major conclusion of the study is that in both cities the majority (more than 50%) of the tota...

439

CHARACTERIZAITON OF PARTICULATE EMISSIONS FROM MUNICIPAL WASTEWATER SLUDGE INCINERATORS  

EPA Science Inventory

Particulate emissions from a group of municipal sludge incinerators with multiple-hearth furnaces, one with a fluidized-bed furnace were characterized. Three plants operated at or near autogenous burning conditions. Chemical element composition was determined for total and sized ...

440

40 CFR 52.2584 - Control strategy; Particulate matter.  

Code of Federal Regulations, 2010 CFR

...On April 30, 1988 and March 30, 1990, the State of Wisconsin submitted committal SIPs for particulate matter with an aerodynamic diameter equal to or less than 10 micrometers (PM10 ) for the Group II areas within the Cities of DePere,...

2010-07-01

441

40 CFR 52.776 - Control strategy: Particulate matter.  

...On June 23, 1988, and July 17, 1989, the State of Indiana submitted committal SIPs for particulate matter with an aerodynamic diameter equal to or less than 10 micrometers (PM10 ) for the Group II areas within Marion and Vigo Counties and...

2014-07-01

442

40 CFR 52.2584 - Control strategy; Particulate matter.  

Code of Federal Regulations, 2013 CFR

...On April 30, 1988 and March 30, 1990, the State of Wisconsin submitted committal SIPs for particulate matter with an aerodynamic diameter equal to or less than 10 micrometers (PM10 ) for the Group II areas within the Cities of DePere,...

2013-07-01

443

40 CFR 52.2584 - Control strategy; Particulate matter.  

...On April 30, 1988 and March 30, 1990, the State of Wisconsin submitted committal SIPs for particulate matter with an aerodynamic diameter equal to or less than 10 micrometers (PM10 ) for the Group II areas within the Cities of DePere,...

2014-07-01

444

40 CFR 52.2584 - Control strategy; Particulate matter.  

Code of Federal Regulations, 2011 CFR

...On April 30, 1988 and March 30, 1990, the State of Wisconsin submitted committal SIPs for particulate matter with an aerodynamic diameter equal to or less than 10 micrometers (PM10 ) for the Group II areas within the Cities of DePere,...

2011-07-01

445

REGIONAL PARTICULATE MODEL - 1. MODEL DESCRIPTION AND PRELIMINARY RESULTS  

EPA Science Inventory

The gas-phase chemistry and transport mechanisms of the Regional Acid Deposition Model have been modified to create the Regional Particulate Model, a three-dimensional Eulerian model that simulates the chemistry, transport, and dynamics of sulfuric acid aerosol resulting from pri...

446

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, ...

447

EVALUATION OF PARTICULATE MASS MONITORS USING THE BETA GAUGE TECHNIQUE  

EPA Science Inventory

A field study was conducted to evaluate two commercially available beta gauge instruments for measuring particulate mass concentrations in stationary source emissions. Performance of the instruments was compared with a manual method of measurement at a ferrite rotary-kiln calcine...

448

Comparative Analysis on the Effects of Diesel Particulate Filter and  

E-print Network

Comparative Analysis on the Effects of Diesel Particulate Filter and Selective Catalytic Reduction February 15, 2008. Revised manuscript received May 2, 2008. Accepted May 27, 2008. Two methods, diesel that these aftertreatment systems may have on the emission levels of a wide spectrum of chemical species found in diesel

Wu, Mingshen

449

REVIEW OF DIESEL PARTICULATE MATTER SAMPLING FINAL REPORT  

E-print Network

REVIEW OF DIESEL PARTICULATE MATTER SAMPLING METHODS FINAL REPORT Prepared by David B. Kittelson of Mechanical Engineering Center for Diesel Research Minneapolis, MN January 14, 1999 #12;01/14/99 Page 2 TABLE ................................................................................................................5 DIESEL ENGINE TECHNOLOGY AND EMISSION REGULATIONS .............................7 PHYSICAL

Minnesota, University of

450

METHOD FOR ESTIMATING FUGITIVE PARTICULATE EMISSIONS FROM HAZARDOUS WASTE SITES  

EPA Science Inventory

Control techniques are reviewed for applicability to fugitive particulate emissions from hazardous waste sites. Techniques judged applicable include chemical stabilization (40 to 100 percent efficiency, $520/acre-yr to $2,720/acre-yr), wet suppression (25 to 90 percent efficiency...

451

Analysis of water seepage through earthen structures using particulate approach  

Microsoft Academic Search

A particulate model is developed to analyze the effects of steady state and transient seepage of water through a randomly-packed coarse-grained soil as an improvement to conventional seepage analysis based on continuum models. In the new model the soil skeleton and pore water are volumetrically coupled. In the first phase of the study, the concept of relative density has been

Kalyani Jeyisanker

2008-01-01

452

Airborne particulate soiling of terrestrial photovoltaic modules and cover materials  

Microsoft Academic Search

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,

A. R. Hoffman; C. R. Maag

1980-01-01

453

Electrically heated particulate filter diagnostic systems and methods  

SciTech Connect

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.

Gonze, Eugene V [Pinckney, MI

2009-09-29

454

Inductively heated particulate matter filter regeneration control system  

SciTech Connect

A system includes a particulate matter (PM) filter with an upstream end for receiving exhaust gas, a downstream end and zones. The system also includes a heating element. A control module selectively activates the heating element to inductively heat one of the zones.

Gonze, Eugene V; Paratore Jr., Michael J; Kirby, Kevin W; Phelps, Amanda; Gregoire, Daniel J

2012-10-23

455

40 CFR 266.105 - Standards to control particulate matter.  

Code of Federal Regulations, 2013 CFR

40 Protection of Environment 28 2013-07-01 2013-07-01 false Standards to control particulate...the stack gas according to the formula: ER30SE99.027 Where: Pc is the corrected concentration of the pollutant in the stack...

2013-07-01

456

HOOD SYSTEM DESIGN FOR CAPTURE OF PROCESS FUGITIVE PARTICULATE EMISSIONS  

EPA Science Inventory

The paper discusses a technical manual whose emphasis is on the design and evaluation of actual hood systems used to control various fugitive particulate emission sources. Engineering analyses of the most important hood types are presented to provide a conceptual understanding of...

457

PARTICULATE MATTER ELEMENTAL COMPOSITION BY X-RAY FLUORESCENCE ANALYSIS  

EPA Science Inventory

This task is primarily concerned with the elemental characterization, by X-ray fluorescence analysis, of particulate matter (PM) collected during active or passive sampling of ambient air. The NERL X-ray fluorescence laboratory is an in-house research facility dedicated to quant...

458

TECHNOLOGY ASSESSMENT REPORT FOR INDUSTRIAL BOILER APPLICATIONS: PARTICULATE COLLECTION  

EPA Science Inventory

The report assesses applicability of particulate control technology to industrial boilers. It is one of a series to aid in determining the technological basis for a New Source Performance Standard for Industrial Boilers. It gives current and potential capabilities of alternative ...

459

NOAA Technical Report ERL 417-PMEL 35 Suspended Particulate Matter  

E-print Network

and Duwamish River runoff in winter, 2) a uniform mid-depth minimum-SPM zone, and 3) a bottom nepheloid layer nepheloid layer in Elliott Bay. iv #12;Suspended Particulate Matter in Elliott Bay Edward T. Baker 1) a thin «5 m) surface layer of variable SPM concentration dominated by phytoplankton growth in summer

460

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...

461

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...

462

Fatty Acids in Surface Particulate Matter from the North Atlantic.  

National Technical Information Service (NTIS)

The fatty acid composition of particulate matter from surface waters in the North Atlantic has been investigated. A high proportion is long-chain polyunsaturated acids, typical of a marine origin. The low relative abundance of iso and anteiso 15-carbon ac...

D. M. Schultz, J. G. Quinn

1972-01-01

463

Self-healing of damaged particulate materials through sintering  

Microsoft Academic Search

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

S. Luding; A. S. J. Suiker

2008-01-01

464

DIII-D dust particulate characterization (June 1998 Vent)  

SciTech Connect

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.

Carmack, W.J.

1999-01-01

465

DIII-D Dust Particulate Characterization (June 1998 Vent)  

SciTech Connect

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.

Carmack, William Jonathan

1999-01-01

466

ASSESSMENT OF DIESEL PARTICULATE CONTROL: FILTERS, SCRUBBERS, AND PRECIPITATORS  

EPA Science Inventory

The report discusses an investigation of three types of devices that might be used for the aftertreatment of diesel exhaust to lower particulate emissions from light-duty vehicles. The devices are filters, electrostatic precipitators (ESPs), and wet scrubbers. The conclusions rea...

467

40 CFR 60.292 - Standards for particulate matter.  

Code of Federal Regulations, 2012 CFR

...STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Glass Manufacturing...following equation: STD=X [1.3(Y)+(Z)] Where: STD=Particulate matter...60.296(b). (joules/joules). Z=(1-Y). (b) Conversion of a...

2012-07-01

468

40 CFR 60.292 - Standards for particulate matter.  

Code of Federal Regulations, 2011 CFR

...STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Glass Manufacturing...following equation: STD=X [1.3(Y)+(Z)] Where: STD=Particulate matter...60.296(b). (joules/joules). Z=(1-Y). (b) Conversion of a...

2011-07-01

469

40 CFR 60.292 - Standards for particulate matter.  

Code of Federal Regulations, 2010 CFR

...STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Glass Manufacturing...following equation: STD=X [1.3(Y)+(Z)] Where: STD=Particulate matter...60.296(b). (joules/joules). Z=(1-Y). (b) Conversion of a...

2010-07-01

470

40 CFR 60.102 - Standard for particulate matter.  

Code of Federal Regulations, 2010 CFR

...heat boiler in which auxiliary or supplemental liquid or solid fossil fuel is burned, particulate matter in excess of that permitted...Btu)) of heat input attributable to such liquid or solid fossil fuel. [39 FR 9315, Mar. 8, 1974, as amended at 42...

2010-07-01

471

Determination of s(iv) in particulate matter  

NASA Astrophysics Data System (ADS)

Sulfur (IV) is extracted from particulate matter with a formaldehyde based solution containing a chelating agent for the dissolution of insoluble sulfites. Measurement is subsequently made by a spectrophotometric method, based on the Schiff reaction with pararosaniline. Results are presented for several simple inorganic sulfites, carbonyl-S(IV) addition compounds, fly ash and smelter samples and "Fe(III)-S(IV)" aerosol.

Dasgupta, Purnendu K.; DeCesare, Kymron B.; Brummer, Margaret

472

Wet scrubbing for particulate removal on industrial boilers  

Microsoft Academic Search

In 1972, the State of New York passed the Air Pollution Control Act, thereby establishing limits for the emission of particulates and various obnoxious gases. Industries were required to perform tests on emission sources and prepare plans and schedules for compliance on each source exceeding the established limits. This discussion will center on United States Gypsum Company's Oakfield, New York,

L. E. Faught

1975-01-01

473

Health Effects of Fine Particulate Air Pollution: Lines that Connect  

Microsoft Academic Search

Efforts to understand and mitigate the health effects of particulate matter (PM) air pollution have a rich and interesting history. This review focuses on six substantial lines of research that have been pursued since 1997 that have helped elucidate our understanding about the effects of PM on human health. There has been substantial progress in the evaluation of PM health

C. Arden Pope III; Douglas W. Dockery; Joe L. Mauderly; Daniel L. Costa; Ronald E. Wyzga; Sverre Vedal; George M. Hidy; Sam L. Altshuler; David Marrack; Jon M. Heuss; George T. Wolff

2006-01-01

474

Particulate air pollution and daily mortality in detroit  

Microsoft Academic Search

Particulate air pollution has been associated with increased mortality during episodes of high pollution concentrations. The relationship at lower concentrations has been more controversial, as has the relative role of particles and sulfur dioxide. Replication has been difficult because suspended particle concentrations are usually measured only every sixth day in the U.S. This study used concurrent measurements of total suspended

J. Schwartz

1991-01-01

475

Increased Particulate Air Pollution and the Triggering of Myocardial Infarction  

Microsoft Academic Search

Background—Elevated concentrations of ambient particulate air pollution have been associated with increased hospital admissions for cardiovascular disease. Whether high concentrations of ambient particles can trigger the onset of acute myocardial infarction (MI), however, remains unknown. Methods and Results—We interviewed 772 patients with MI in the greater Boston area between January 1995 and May 1996 as part of the Determinants of

Annette Peters; Douglas W. Dockery; James E. Muller; Murray A. Mittleman

2001-01-01

476

PROTON SCATTERING ANALYSIS FOR LIGHT ELEMENTS IN AIR PARTICULATE MATTER  

EPA Science Inventory

Proton scattering analysis has been developed to provide light element analyses as a complementary method to x-ray analysis. Samples of air particulate matter from both filter and impaction devices have been analyzed and time sequence and particle size information obtained. In co...

477

APTI Course 450, Source Sampling for Particulate Pollutants. Instructor's Guide.  

ERIC Educational Resources Information Center

This manual covers a four and one half day laboratory course in source sampling for particulates. The course presents principles and techniques necessary for performing isokinetic source sampling procedures. Lectures cover formulas dealing with basic fluid mechanics appropriate to the techniques employed. Laboratory exercises are intended to…

Aldina, G. J.; And Others

478

Developing Meaningful Measures and Guidelines for Particulates in Aquatic Ecosystems  

NASA Astrophysics Data System (ADS)

Managing global water resources is one of the greatest challenges of the 21st Century. It is a resource that is under growing pressure as global populations rise and the natural supply, in the form of precipitation, is becoming increasingly variable and uncertain with climate change. It is therefore essential that water resources (surface and groundwaters) are managed sustainably in terms of both their quantity and quality. One of the most common causes for the impairment of water quality in surface waters and groundwaters is the presence of particulate matter. Particulate matter, from nano-scale particles and colloids to silt-sized sediments, can have a range of detrimental effects on water resources, from aesthetic issues and higher costs of water treatment, to a decline in the fisheries resource and serious ecological degradation. However at present, there is a poor understanding of the particulate conditions that water quality managers should aim to achieve in order to support good ecological status in different environments. There is also currently a general lack of rigour and standardisation in measurements of particulate matter in aquatic ecosystems, which in turn limits our understanding of the effects of these particles, and importantly, limits our ability to guide effective remediation. This poster describes a research approach that is currently being developed in the UK to address these issues; supporting (1) the development of ecosystem-specific water quality guidelines for particulate matter, and (2) the innovation of more advanced monitoring technologies for particulate matter in aquatic environments. The research project will utilise an established network of 13 reference condition sites (i.e. sites that have minimal anthropogenic disturbance) that contain distinct aquatic communities and are located in contrasting environment types. Hydrological and biological monitoring will be carried-out concurrently with analysis of the physical and geochemical properties of the particulates in each environment. Monitoring of the dynamics of these parameters will continue for 3.5 years, providing a medium to long-term record that can be used to develop statistical models and inform both water resource policy and technological innovation.

Bilotta, G. S.; Harrison, C.; Joyce, C.; Peacock, C.

2010-12-01

479

PII S0016-7037(99)00361-0 Dissolved and particulate carbohydrates in contrasting marine sediments  

E-print Network

PII S0016-7037(99)00361-0 Dissolved and particulate carbohydrates in contrasting marine sediments D) Abstract--Dissolved and particulate carbohydrates were examined in contrasting Chesapeake Bay (estuarine) and mid-Atlantic shelf/slope break (continental margin) sediments. Particulate carbohydrates (PCHOs) rep

Burdige, David

480

Gas?particulate phase distribution and decay rates of constituents in ageing environmental tobacco smoke  

Microsoft Academic Search

Phase distribution and decay rates of ETS components were determined for an experimental room. Solanesol and protonated nicotine behave like particulate matter (UV?PM). Free nicotine evaporates from the particulate phase during the 5 minute sampling time and decays rapidly from the gaseous phase. Neophytadiene leaves the particulate phase faster than predicted by deposition. Limonene, 3?ethenylpyridine, and naphthalene are present only

Georg B. Neurath; Sylvia Petersen; Michael Dunger; Dorothea Orth; F. Gerhard Pein

1991-01-01

481

40 CFR 49.125 - Rule for limiting the emissions of particulate matter.  

Code of Federal Regulations, 2013 CFR

...for limiting the emissions of particulate matter. 49.125 Section 49.125 Protection...for limiting the emissions of particulate matter. (a) What is the purpose of this...section limits the amount of particulate matter that may be emitted from certain...

2013-07-01

482

40 CFR 49.125 - Rule for limiting the emissions of particulate matter.  

Code of Federal Regulations, 2012 CFR

...for limiting the emissions of particulate matter. 49.125 Section 49.125 Protection...for limiting the emissions of particulate matter. (a) What is the purpose of this...section limits the amount of particulate matter that may be emitted from certain...

2012-07-01

483

Particulate generation and control in the PREPP (Process Experimental Pilot Plant) incinerator  

Microsoft Academic Search

Particulate emissions in radioactive incineration systems using a wet scrubbing system are generally ultimately controlled by flowing the process offgas stream through a high-efficiency filter, such as a High Efficient Particulate Air (HEPA) filter. Because HEPA filters are capable of reducing particulate emissions over an order of magnitude below regulatory limits, they consequently are vulnerable to high loading rates. This

D. L. Stermer; L. G. Gale

1989-01-01

484

Association of Heart Rate Variability With Occupational and Environmental Exposure to Particulate Air Pollution  

Microsoft Academic Search

Background—Airborne particulate matter has been linked to excess morbidity and mortality. Recent attention has focused on the effects of particulate exposure on cardiac autonomic control. Inhaled particulates may affect the autonomic nervous system either directly, by eliciting a sympathetic stress response, or indirectly, through inflammatory cytokines produced in the lungs and released into the circulation. Methods and Results—This longitudinal study

Shannon R. Magari; Russ Hauser; Joel Schwartz; Paige L. Williams; Thomas J. Smith; David C. Christiani

2001-01-01

485

40 CFR 49.125 - Rule for limiting the emissions of particulate matter.  

Code of Federal Regulations, 2010 CFR

...for limiting the emissions of particulate matter. 49.125 Section 49.125 Protection...for limiting the emissions of particulate matter. (a) What is the purpose of this...section limits the amount of particulate matter that may be emitted from certain...

2010-07-01

486

40 CFR 49.125 - Rule for limiting the emissions of particulate matter.  

Code of Federal Regulations, 2011 CFR

...for limiting the emissions of particulate matter. 49.125 Section 49.125 Protection...for limiting the emissions of particulate matter. (a) What is the purpose of this...section limits the amount of particulate matter that may be emitted from certain...

2011-07-01

487

Calibration of sediment traps and particulate organic carbon export Th in the Barents Sea  

E-print Network

Calibration of sediment traps and particulate organic carbon export using 234 Th in the Barents Sea July 2002 Abstract Profiles of particulate and dissolved 234 Th (t1/2 = 24.1 days) in seawater and particulate 234 Th collected in drifting traps were analyzed in the Barents Sea at five stations during

Coppola, Laurent

488

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,...

489

Electrically heated particulate filter regeneration methods and systems for hybrid vehicles  

DOEpatents

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.

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

2010-10-12

490

FEASIBILITY OF PLASMA AFTERTREATMENT FOR SIMULTANEOUS CONTROL OF NOX AND PARTICULATES  

EPA Science Inventory

Plasma reactors can be operated as a particulate trap or as a NOx converter. Particulate trapping in a plasma reactor can be accomplished by electrostatic precipitation. The soluble organic fraction of the trapped particulates can be utilized for the hydrocarbon-enhanced oxidat...

491

Direct-energy-regenerated particulate trap technology. Final report  

SciTech Connect

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 SiC to uniformly heat the filter and oxidize the collected carbon particulates. For commercial usage particulate traps must: (1) filter carbon particulates from a high temperature diesel exhaust at an acceptably low backpressure, (2) survive thousands of thermal transients due to regeneration or cleaning of the filter by oxidizing the collected carbon, (3) be durable and reliable over the expected life of the filter (300,000 miles or 10,000 hours), and (4) provide a low overall operating cost which is competitive with other filtering techniques. The development efforts performed as part of this CRADA have resulted in a very promising new technology for Cummins Engine Company. Ceramic fiber based filter papers were developed at Fleetguard, Inc., (a Cummins Subsidiary) and used to produce the spiral wound, corrugated filter cartridges. Optimized SiC coatings were developed at Lockheed Martin which couple with 2.45 GHz microwaves. Prototype particulate filter cartridges fabricated at Fleetguard and rigidized at Lockheed Martin performed well in single cylinder engine tests at Cummins. These prototype filters obtained filtering efficiencies greater than 80% at acceptably low backpressures and could be successfully headed and regenerated using a conventional in-home microwave oven.

Stinton, D.P.; Janney, M.A. [Oak Ridge National Lab., TN (United States); Yonushonis, T.M.; McDonald, A.C.; Wiczynski, P.D. [Cummins Engine Co., Inc., Columbus, IN (United States); Haberkamp, W.C. [Fleetguard, Inc. (United States)

1996-12-01

492

Stimulation of an ?1-adrenergic receptor downregulates ecto-5? nucleotidase activity on the apical membrane of RPE cells  

Microsoft Academic Search

The purines ATP and adenosine play an important role in the communication between the photoreceptors and the retinal pigment\\u000a epithelium (RPE). While the RPE is known to release ATP into subretinal space, the source of extracellular adenosine is unclear.\\u000a In other tissues, ecto-nucleotidases mediate the consecutive dephosphorylation of ATP to AMP, and AMP is converted to adenosine\\u000a by ecto-5? nucleotidase

David Reigada; Xiulan Zhang; Ana Crespo; Johnathan Nguyen; Ji Liu; Klara Pendrak; Richard A. Stone; Alan M. Laties; Claire Mitchell

2006-01-01

493

NTPDase and 5?-nucleotidase Activities of Synaptosomes from Hippocampus of Rats Subjected to Hyperargininemia  

Microsoft Academic Search

ATP is an important excitatory neurotransmitter and adenosine acts as a neuromodulatory structure inhibiting neurotransmitters\\u000a release in the central nervous system. Since the ecto-nucleotidase cascade that hydrolyzes ATP to adenosine is involved in\\u000a the control of brain functions and previous studies realized in our laboratory have recently reported that acute administration\\u000a of Arg decreases the NTPDase and 5?-nucleotidase activities of

Daniela Delwing; Manuela C. F. Gonçalves; João J. F. Sarkis; Angela T. S. Wyse

2007-01-01

494

Effect of acute stress on NTPDase and 5?-nucleotidase activities in brain synaptosomes in different stages of development  

Microsoft Academic Search

The aim of the present study was to examine the effect of acute restraint stress on rat brain synaptosomal plasma membrane (SPM) ecto-nucleotidase activities at specific stages of postnatal development (15-, 30-, 60- and 90-day-old rats) by measuring the rates of ATP, ADP and AMP hydrolysis 1, 24 and 72h post-stress. At 1h after stress NTPDase and ecto-5?-nucleotidase activities were

Anica Horvat; Ivana Stanojevi?; Dunja Drakuli?; Nataša Veli?kovi?; Snježana Petrovi?; Maja Miloševi?

2010-01-01

495

Therapeutic potentials of ecto-nucleoside triphosphate diphosphohydrolase, ecto-nucleotide pyrophosphatase/phosphodiesterase, ecto-5'-nucleotidase, and alkaline phosphatase inhibitors.  

PubMed

The modulatory role of extracellular nucleotides and adenosine in relevance to purinergic cell signaling mechanisms has long been known and is an object of much research worldwide. These extracellular nucleotides are released by a variety of cell types either innately or as a response to patho-physiological stress or injury. A variety of surface-located ecto-nucleotidases (of four major types; nucleoside triphosphate diphosphohydrolases or NTPDases, nucleotide pyrophosphatase/phosphodiesterases or NPPs, alkaline phosphatases APs or ALPs, and ecto-5'-nucleotidase or e5NT) are responsible for meticulously controlling the availability of these important signaling molecules (at their respective receptors) in extracellular environment and are therefore crucial for maintaining the integrity of normal cell functioning. Overexpression of many of these ubiquitous ecto-enzymes has been implicated in a variety of disorders including cell adhesion, activation, proliferation, apoptosis, and degenerative neurological and immunological responses. Selective inhibition of these ecto-enzymes is an area that is currently being explored with great interest and hopes remain high that development of selective ecto-nucleotidase inhibitors will prove to have many beneficial therapeutic implications. The aim of this review is to emphasize and focus on recent developments made in the field of inhibitors of ecto-nucleotidases and to highlight their structure activity relationships wherever possible. Most recent and significant advances in field of NTPDase, NPP, AP, and e5NT inhibitors is being discussed in detail in anticipation of providing prolific leads and relevant background for research groups interested in synthesis of selective ecto-nucleotidase inhibitors. PMID:24115166

al-Rashida, Mariya; Iqbal, Jamshed

2014-07-01

496

Exposure to Hg 2+ and Pb 2+ changes NTPDase and ecto-5?-nucleotidase activities in central nervous system of zebrafish ( Danio rerio)  

Microsoft Academic Search

Neurotransmission can be affected by exposure to heavy metals, such as mercury and lead. ATP is a signaling molecule that can be metabolized by a group of enzymes called ecto-nucleotidases. Here we investigated the effects of mercury chloride (HgCl2) and lead acetate (Pb(CH3COO)2) on NTPDase (nucleoside triphosphate diphosphohydrolase) and ecto-5?-nucleotidase activities in zebrafish brain membranes. In vitro exposure to HgCl2

Mario Roberto Senger; Eduardo Pacheco Rico; Marcelo de Bem Arizi; Ana Paula Guedes Frazzon; Renato Dutra Dias; Maurício Reis Bogo; Carla Denise Bonan

2006-01-01

497

PRELIMINARY RESULTS: MODELING FINE PARTICULATE MASS FOR THE EASTERN UNITED STATES USING THE EPA REGIONAL PARTICULATE MODEL  

EPA Science Inventory

PM-10, particulate matter less than 10um, is one of several criteria air pollutants for which National Ambient Air Quality Standards (NAAQS) are established by the United States Environmental Protection Agency (EPA) to protect human wealth and welfare. ecently, attention has been...

498

Assessments of pulmonary macrophage clearance responses to inhaled particulates.  

PubMed

An integrated bioassay program is being developed to evaluate the toxicity of inhaled particulate materials. The multi-disciplined approach combines studies on lung clearance mechanisms with pulmonary macrophage functional assessments based on cellular biology, biochemical and cytochemical evaluations on lung specimens from exposed animals. To validate this method, animals were exposed to asbestos, iron-treated asbestos, fiberglass, Mt. St. Helens ash or carbonyl iron particles. Deposition patterns, macrophage migration and phagocytosis were monitored in vivo at selected time periods after exposure. Our results showed that chemotactic factor generation by particles in vitro correlated with the corresponding macrophage recruitment responses in vivo. In addition, macrophage morphologic and functional characteristics were evaluated following exposures to aerosolized dusts. Our results suggest that scanning electron microscopy (SEM) techniques for investigating particle deposition and macrophage clearance provide an important component for evaluating the toxicity of inhaled particulate materials. PMID:3399846

Warheit, D B; Hartsky, M A

1988-06-01

499

Solid-particle erosion of aluminum/particulate ceramic composites  

SciTech Connect

Impact erosion of 2014 aluminum, 2014 aluminum + 20 vol % particulate silicon carbide, and 2014 aluminum + 20 vol % particulate aluminum oxide has been studied at room temperature. The alloys were tested in the as-received and heat-treated conditions. Experiments were conducted with aluminum oxide abrasive in vacuum in a slinger-type apparatus over a range of abrasive size, velocity, and angle of impact. Erosion rates were influenced by reinforcement and heat treatment. Reduced ductility, both overall and local, attributed to reinforcement or heat treatment, caused, under most conditions, more rapid erosion of the composites. The data suggest that erosion rate can be minimized by proper microstructural control, involving reducing reinforcement segregation and the amount of intermetallic compounds. 37 refs., 7 figs.

Goretta, K.C.; Wu, W.; Routbort, J.L. (Argonne National Lab., IL (USA)); Rohatgi, P.K. (Wisconsin Univ., Milwaukee, WI (USA))

1990-06-01

500

Statistical analysis of the particulation of shaped charge jets  

SciTech Connect

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.

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

1999-08-12